Summer Meeting of the Anatomical Society: Dublin 2022

O1Development of a human biomimetic stem cell scaffold for spinal cord repair

Cian O'Connor

Tissue Engineering Research Group, Royal College of Surgeons in Ireland (RCSI), Dublin 2, Ireland

Following spinal cord injury, a large lesion cavity forms preventing axonal regrowth. Despite the ongoing development of stem cell treatments, effective repair remains a considerable challenge in part due to the lack of a supportive environment. Therapeutic implants that physically bridge the cavity with a neurotrophic environment while simultaneously delivering stem cells to restore lost tissue may have potential. Building off success in our labs for peripheral nerve repair, we aimed to identify cord-specific growth-promoting proteins, incorporate them into biomaterial scaffold implants with anatomically relevant properties and validate its trophic capacity using different cell models. By optimizing scaffold stiffness and matrix composition for stem cell delivery, we aimed to create a revolutionary therapeutic scaffold in combination with induced pluripotent stem cell (iPSC)-derived progenitors to promote spinal cord repair.

Extensive screening of extracellular matrix (ECM) proteins revealed that a combination of collagen-IV (Coll-IV) and fibronectin (FN) synergistically enhanced neuronal and astrocyte outgrowth. Next, hyaluronic acid scaffolds functionalized with Coll-IV/FN were manufactured with differing stiffnesses from soft/biomimetic-stiff/supraphysiological (0.8–3 kPa). Astrocytes cultured in soft but not stiffer Coll-IV/FN scaffolds exhibited morphologies typical of normal ‘resting’ cells, and upregulated secretion of anti-inflammatory factors while also enhancing neurite outgrowth from neurons. Soft, Coll-IV/FN scaffolds also promoted iPSC-progenitor cell infiltration, and growth into large spheroid structures. Conditioned media taken from soft CIV/FN iPSC-containing scaffolds significantly enhanced neurite outgrowth 2.8-fold. Finally, when spinal cord and dorsal root ganglia (a mature model of axonal growth) explants were cultured on soft Coll-IV/FN iPSC-scaffolds, astrocyte migration and long axonal extensions between dorsal root ganglia and iPSC-spheroids within scaffolds were significantly enhanced.

In summary, this work shows the successful development of a novel anatomically inspired scaffold that when combined with iPSC-progenitors has significant therapeutic potential for cord applications. This work is funded by the Anatomical Society, IRFU-Charitable Trust and SFI-AMBER centre. All relevant ethics were reviewed and approved by the appropriate agencies before carrying out any work.

O2Collaborative dissection through the development of an online wiki positively impacts the learning of canine anatomy

Michael Frill

Department of Comparative Biomedical Sciences, Royal Veterinary College, London, UK

In response to the COVID-19 restrictions imposed on the UK during the early part of 2021, we developed a series of dissections of the canine abdomen to facilitate social distancing in the dissection room. To achieve social distancing, students worked in pairs either dissecting or documenting a prescribed part of the canine abdomen. They rotated roles and recorded their work as videos and photographs. Student pairs worked on one of three regions of the abdomen, and upon completion, three pairs gathered to collate their work. Students produced a wiki-style portfolio of the whole abdomen and tested their knowledge through an online formative multiple-choice test.

Analysis of student marks from the test showed that whilst students could meet the learning outcomes by only studying the wiki, students performed better in areas where they had dissected the related anatomy (an increase of 7% in test score marks, from 78% to 85%, p < 0.05). Furthermore, students performed equally as well in areas where they were present but only recorded the dissection (84%), compared with areas they had actively dissected themselves (85%) (p > 0.05). Thematic analysis of student feedback from the project showed that students valued many aspects of the dissection experience, including collaboration and development of practical skills. Some aspects of the use of technology and recording of the dissection were shown to promote engagement, whilst others could hinder the experience. Our results support the notion that although knowledge-based learning objectives can be met without dissection, the practical element of learning anatomy is necessary for optimum success.

Canine cadavers were shelter dogs, humanely euthanised, embalmed and transported to London, UK by Carolina Biological Supply Company. All experiments were performed with the full understanding and consent of the human subjects and were approved by the Social Science Research Ethical Review Board at the Royal Veterinary College (URN SR2020-0326)

O3Punk microscopy: Democratising discovery with accessible imaging solutions

Mark Pickering

School of Medicine, University College Dublin, Belfield, Dublin, Ireland

Recent decades have seen microscopy become a dominant technique across the spectrum of biological research. This expansion in the utility of microscopy has undoubtedly been facilitated by emergence of new technical capabilities, such as super resolution and light sheet microscopy, which have opened the door for new analytical techniques, allowing microscopy to be deployed to address a new suite of scientific questions. However, this sophistication has come at a cost. Modern research microscopes are technically complex and expensive, and require significant technical skill for operation and maintenance. This has put microscopy beyond the reach of many who could use it, as well as potentially limiting experimental flexibility; choices made in the investment in specialised microscopes inevitably mean a reduction in the diversity and variety of imaging tools available to individual researchers.

We faced this problem when needing to carry out microscopic analysis of the neuroanatomical organization of the ctenophore Pleurobrachia pileus, a small, almost spherical animal with a nervous system arranged in a net within the surface epithelium. Without knowing the best microscope type for our needs, we developed the Flexiscope, a modular, flexible and convertible microscope. We subsequently developed the Incubot, a low cost, automated microscope capable of remote monitoring of plates of cells in culture, constructed using the mechanical components of a 3D printer. This approach to on-demand development of flexible or bespoke optical devices has been made possible by the availability of low-cost microcontrollers, single board computers and other electronic components, as well as 3D printing and rapid prototyping techniques. We have developed multiple custom optical devices as needed using this approach, including simple light sheet systems and optical projection tomography scanners, to complete a detailed characterization of the anatomical arrangement of the nervous system in P. pileus.

Our current work is focused on developing further optical devices for a range of applications, including microscopy in the field and microplastic detection. These open, accessible and cost-effective designs put microscopic analyses in the hands of those who otherwise could not easily access them, facilitating truly global solutions to global problems.

O4Targeting the neuroinflammatory response after spinal cord injury in mice

Dearbhaile Dooley

School of Medicine, University College Dublin, Belfield, Dublin, Ireland

Traumatic spinal cord injury (SCI) is a complex medical challenge which diminishes quality of life and leads to severe impairments, largely because the central nervous system (CNS) has a limited capacity to replace lost neurons, repair damaged axons or re-establish functional circuits. Approximately 27 million people worldwide are living with a long-term disability following SCI and despite major research progress, there are still no injury-modifying or regenerative treatments currently available. Experimental approaches over the past two decades in preclinical SCI have focused on: cell and/or tissue transplantation, blocking inhibition of neural regeneration, enhancing axonal regeneration, and modulating pro- and anti-inflammatory responses.

Following SCI, microglia and macrophages dominate the pathological environment and can exert either beneficial or detrimental effects, depending on their activation state. Put simply, they are situated between two spectral ends of functional activation: classically activated which secrete pro-inflammatory molecules contributing to deleterious effects or alternatively activated which secrete anti-inflammatory mediators and neurotrophic factors, which help restore a pro-regenerative environment. Using CX3CR1EGFP/+ CCR2RFP/+ mice to discriminate between resident microglia and blood-borne macrophages, we have previously demonstrated that expression of markers associated with classical or alternative activation are significantly more pronounced in infiltrating macrophages as compared to resident microglia, upon therapeutic delivery of interleukin 13 via mesenchymal stem cells after SCI. This was associated with a significant improvement in histopathological and functional outcome. The differential phenotypic behaviour of in vivo microglia and macrophages is in striking contrast to multiple in vitro studies which demonstrate that microglia can be easily triggered to adopt a state of classical or alternative activation, when taken out of their natural environment. However, the proximity of neurons, glial and immune cells appears to affect the way in which microglia react to CNS injury, thereby hindering their regeneration-supportive properties. All animal experiments were performed according to the guidelines of EU directive 2010/63/EU on the protection of animals used for scientific purposes.

O5The secrets of sperm storage, fertilization and early embryonic development within the female genital tract in humans and cows—and what we can learn from it

Sabine Kölle

School of Medicine, University College Dublin, Belfield, Dublin, Ireland

Successful fertilization only occurs if the spermatozoa reach the oocyte in time. Using a unique live cell imaging technology, the purpose of the study was to investigate the formation of the sperm reservoir, fertilization, and early embryogenesis in the oviduct in real-time and under near in vivo conditions in the animal model of the cow and in the human. We were able to show that the cumulus-oocyte complex attaches to the ampullar epithelium immediately after ovulation. This initiates a signalling cascade leading the sperm to the site of fertilization. We provide the first proof of the formation of a human sperm reservoir in the ampulla and isthmus of the oviduct. It is characterized by temporary sperm binding, attachment to microvilli of the tubal epithelial cells, and competitive binding behaviour. After one sperm has penetrated the zona pellucida, the glycoproteins of this layer change configuration so that no other sperm can enter the oocyte. During the migration of the early embryo within the oviduct, we provide evidence of the first embryo-maternal communication in the oviduct on day 2 after fertilization. This knowledge creates the basis for novel concepts to improve reproductive health and to successfully treat idiopathic male and female infertility. Thus, our studies revealed that female idiopathic infertility is often caused by inflammation and blockage of the tube. Regarding male infertility, spermatozoa which lack fertilizing capability are either not able to bind to the oviductal epithelium to form the sperm reservoir or to detach from the epithelium in the presence of the oocyte. Diseases associated with inflammation in the female genital tract result in sperm being stuck in mucus, thus being eliminated from the fertilization process. In summary, our results show that tubal health and maintenance of sperm fertilizing capacity are pivotal for further increasing reproductive success.

Ethical approval for the studies in humans was obtained from St. James's Hospital, the Mater Hospital and UCD (1/378/1645, 1/378/2140, LS-14-23 and LS-E-21-116). All the experiments were performed with the understanding and consent of each patient. The experiments performed in cows were exempt from ethical approval (AREC-E-18-46-Koelle), as samples were collected after slaughter.

O6Pulmonary hypertension: The structure–function relationship viewed with a stereological eye

Paul McLoughlin

School of Medicine, University College Dublin, Belfield, Dublin, Ireland

Understanding the relationship between the microscopic structure of organs to their function is a key component of anatomical and physiological research. Importantly, the structure of the organs of the body is not constant but changes during development, growth and ageing. Structure and function relationships also change in response to physiological challenges and in disease. However, obtaining quantitative, functionally meaningful, measurements from two-dimensional images such as conventional microscopic images is not as straightforward as might first appear.

Pulmonary hypertension, which frequently occurs as a complication of chronic hypoxic lung diseases, results in right ventricular overload, leads to right heart failure and reduces life expectancy. It is caused by an increased resistance to blood flow in the pulmonary circulation; changes in the structure of the pulmonary vessels are a major contributor to this increase. In this lecture, I will briefly review the principles that underlie stereological techniques and illustrate the power of this approach through examples of its application in the study of pulmonary hypertension. Research undertaken followed Institutional Ethics Board approval and was under license from the Depart of Health Ireland or the Health Products Regulatory Authority as appropriate.

O7Deep learning applications in medical image analysis

Kathleen Curran

School of Medicine, University College Dublin, Belfield, Dublin, Ireland

Recent advances in artificial intelligence have enabled machines to learn complex tasks such as classifying images with impressive performance. The approach used is referred to as deep learning. Despite its success in computer vision, clinical adoption of deep learning in radiology is still limited as it lacks the ability to logically explain its outcomes and therefore be trusted by clinicians. In this talk, I will explain key concepts in deep learning and discuss potential applications for the use of it in medical imaging while highlighting the challenges for clinicians in trusting the results due to the “black box” nature of deep learning models, which hinders clinical adoption.

O8Virtual dissection of the fornix and stria terminalis in young adolescents with psychotic experiences

Olivia Mosley¹; Allison Kelliher¹; Anurag Nasa²; Caoimhe Gaughan²; Elena Roman¹; Erik O'Hanlon³; Darren William Roddy³; Mary Cannon³

¹School of Medicine, Royal College of Surgeons Ireland (RCSI), Dublin, Ireland; ²School of Medicine, Trinity College Dublin, Dublin, Ireland; ³Department of Psychiatry, RCSI, Dublin, Ireland

The fornix and stria terminalis are aligned yet discrete limbic bilateral white matter bundles connecting the hippocampus and amygdala to the both the hypothalamus and septal forebrain areas. Although the hippocampus and amygdala have been linked in psychotic experiences (PEs), their output tracts, the fornix and stria terminalis, are poorly understudied in individuals with PEs. Using MR imaging data from the Adolescent Brain Development study at RCSI, this project aimed to understand the relationship between these tracts, PEs, and neuropsychological measures in a cohort of young adolescents with PEs and age-matched controls.

We performed High Angular Resolution Diffusion Imaging in 61 directions in 25 young adolescents with PEs and controls using 3T MRI and used Constrained Spherical Deconvolution to reconstruct whole brain tracts. The subfields were reliably reconstructed, and we divided the pre (septal) and post (hypothalamic) commissural components of the fornix and stria. The number and volume of tracts in each component of the column were calculated as well as standard diffusion metrics such as mean fractional anisotropy, apparent diffusion coefficient, axial diffusivity, and radial diffusivity. Group differences between PEs and controls were explored using appropriate statistical techniques.

Although no volume differences were found between PE and control groups, distinct diffusion metric differences between the groups were found for both the fornix and stria terminalis. Differences in specific diffusion metrics of both tracts were found along specific parts of the tracts, suggesting that hippocampal and amygdalar outflow may be impacted in young adolescents with PEs.

This project applied sound anatomical principles to the analysis of magnetic resonance psychiatric data. This project has furthered our understanding of the functional anatomy of the fornix and stria terminalis and the influence of the microstructural anatomy on psychological symptoms. Due to the discrete nature of the connectivity of these tracts, this novel technique showing differences in hippocampal and amygdalar output tracts in young adolescents with PEs may prove useful as a potential biomarker for the condition.

Ethics approval was obtained from the Beaumont Hospital REC for the Adolescent Brain Development study.

O9The humeral supracondylar foramen in feline species and its evolutionary significance

Eimear Byrne^1,§; Robert D Johnston^2,3,§; David Kilroy¹; Sourav Bhattacharjee¹

¹School of Veterinary Medicine, University College Dublin (UCD), Dublin, Ireland; ²Trinity Centre for Biomedical Engineering, Trinity College Dublin, Dublin, Ireland; ³Department of Mechanical, Manufacturing & Biomedical Engineering, School of Engineering, Trinity College Dublin, Dublin, Ireland

The humeral supracondylar foramen noticed in the medio-distal part of the humeri in feline species, climbing mammals, and marsupials remain confusing. The foramen appears to pierce the humeral shaft—tilted more to the medial humeral margin—and contains the forelimbs' median nerve and brachial artery. Its function remains unsettled, although the current dogma supports its role in protecting the vessels and nerves of the feline elbow joints. However, such a hypothesis/theory lacks evidence. Interestingly, a vestige of the supracondylar foramen can be noticed in humans in the form of a bony spur—the supracondylar process—near the medial epicondyle of the humeri (incidence 1%). Occasionally, the spur is attached to the humeral medial epicondyle by a fibrous band known as the ligament of Struthers. The ligament is thought to be an embryologic remnant of the now-extinct coracobrachialis longus (or Wood's) muscle noticed in the apes. One explanation for the extinction is the lack of adductor function required in human arms or terrestrial mammals once they discarded their primitive arboreal lives. The hypothesis in this project is that the osseous foramen found in cats now is not part of the distal humeral shaft but rather an ossified remnant of a now obsolete muscular head. To investigate, thorough micro-computed tomographic (micro-CT) scans were conducted on feline humeri followed by digital 3D reconstruction of the humeri. Acquisition of high-resolution imagery datasets enabled precise understanding of the internal fabric of the feline humerus with a clear indication that the outer edge of the foramina in cats lack a bony texture and even projects a different contrast in CT evaluation. Furthermore, it provides evidence toward the presence of a characteristic bony spur, like in humans, as an attachment mechanism characteristic of muscle tendons while inserting into bony parts. The obtained data enforces a rethinking of feline humeral anatomy where the consistent ossification of this vestigial tendon, apart from protecting important vessels and nerves, also bears significance for flexion of the carpus and digits or providing support to the pronator teres muscle.

The project received an ethical exemption from the UCD Animal Research Ethics Committee (AREC) with approval code: AREC-E-20-21-Kilroy.

^§Equal contribution.

O10The role of CDK13 in congenital heart disease in a mouse model and 3D-high-resolution episcopic microscopy imaging

Qazi Waheed Ullah; Aseel Abbad; David Brook; Siobhan Loughna

School of Life Sciences, C-5, Medical School, QMC, University of Nottingham, Nottingham, UK

Congenital heart disease (CHD) constitutes the most common abnormality present at birth, having an overall incidence of ~1% in the United Kingdom. A large multicentre whole exome sequencing (WES) study on 1891 probands, to which our lab was a collaborator, identified three novel genes (CHD4, CDK13 and PRKD1) with de novo mutations in patients with syndromic CHD.

The aim of this study was to characterize the role of CDK13 in heart morphogenesis and development of CHD using a Cdk13-null mouse model. High-resolution episcopic microscopy (HREM) allows 2D and 3D analysis of 2-micron tissue sections. It was utilised to perform phenotypic characterization of wild type (WT), heterozygous and homozygous hearts from the Cdk13-null mouse. To characterize the role of Cdk13 at the molecular and gene expression level, RNA-sequencing was carried on Cdk13-null hearts in comparison to WT controls.

Results of this study show that loss of Cdk13 is not compatible with life and embryos die in-utero. Penetrance of CHDs in the Cdk13-null mouse hearts was 19.1% (n = 9) in heterozygous and 100% (n = 4) in homozygous hearts. Transcriptome sequencing analysis showed that Cdk13 gene ablation results in modulated expression of genes in heart tissues with known roles in the regulation of complex biological and developmental processes such as the morphogenesis of myocardium, heart valves, outflow tract and septation of heart chambers. RNA-seq transcriptome analysis suggests potential disruption of various gene regulatory networks, potentially contributing to the abnormal phenotypes seen in these mutant mouse hearts.

The genetically modified mice studied in this project were raised and maintained in accordance with the guidelines and regulations of the Animal Procedures Act 1986, under a license number P375A76FE granted by The Home Office, UK.

O11Correlative X-ray microtomography and light microscopy of hard tissue sections

David Mills; Alan Boyde

Queen Mary University of London, London, UK

There are large numbers of ground sections of calcified tissues in museum and anatomy department and private collections. Many of these light microscopy (LM) slides are rare, historically important, or impossible to reproduce, for example, deriving from endangered or extinct species. We examined possibilities for a retrospective study of such material with X-ray microtomography (XMT). Microscope slides are in an inconvenient form for XMT. To match the aspect ratio and scanning volume for XMT to the slides, and to economise on beam time, we scanned them in batches. For example, fifteen 75 mm long by 25 mm wide slides were taped together to make a 25 mm square column which was rotated around its long axis when scanning: the coverslips and the slides providing the separation between the samples. We also fabricated special holders like transport containers to hold batches of five slides. We used the MuCAT2 scanner at QMUL, 90 kV, to produce high contrast resolution and high dynamic range XMT. The spatial resolution was limited to 25 μm due to the sample size. The central 25 mm region of a stack took 24 h to scan. Analysis used TomView, ImageJ and Drishti software. Slides were selected to include a range of skeletal and dental tissue types from human, elephant, dog, narwhal, black rhinoceros, prairie marmot and sperm whale. Accurate mineralisation determinations can be made from the XMT data except where sections are too thin and partial volume effects dominate the data. Section thicknesses need to be at least three voxels to allow accurate mineralisation determination – two outer voxels can be discarded, and the central voxel assumed good. Fortunately, most of the ground sections we examined were more than 100 μm thick. We can, therefore, now report mineralisation densities for all the calcified tissues in the context of any mode of LM imaging. Here, we especially favour polarised light microscopy (PLM) since we have constructed an automated instrument with computer control. However, both quantitative and qualitative PLM require well-cleared and plane parallel sections, requirements not always met in older material.

Ethics statement: All samples studied antedated the UK Human Tissues Act 2004 and CITES regulations.

O123D Slicer for digital characterization of the parietal bone with evolutionary significance

Trinity Dockery; Sourav Bhattacharjee

School of Veterinary Medicine, University College Dublin (UCD), Dublin, Ireland

Plenty of literature supports the notion that aquatic mammals (e.g., dolphins) evolved from ruminants with horses spaced between them in the evolutionary pathway. However, the evidence presented within the landscape of such studies is meagre. Most of these studies have relied on the anatomical similarity between organs or body systems. However, one key fact often overlooked is that in anatomy, we deal with geometrical structures and textures; thus, an in-depth anatomical investigation often requires plenty of geometric analyses. Moreover, the term “similarity” becomes vague unless there is a way to quantify it. This project deals with parietal bone that, unlike soft tissue, has defined geometry and provides a wealth of information to test evolutionary hypotheses with real-life numerical datasets eligible for quantification and modelling. Thus, an emerging strategy is to understand parietal bone based on mathematical parameters, including geometrical attributes. The 3D Slicer®—an open-source software for medical imagery data analyses—presents an exciting digital tool toward analyzing computed tomography (CT) scan data. Interestingly, CT scan data on skulls obtained as Digital Imaging and Communications in Medicine (DICOM) files can be handled by 3D Slicer with in-depth analyses, including extraction of mathematical attributes, such as curvature, surface area, and moment of inertia. These numerical attributes can be collected as spreadsheets for further plotting and analyses. As part of this ongoing project, we are currently optimizing the 3D Slicer platform to digitally dissect the parietal bone out of an articulated skull reconstructed from CT imagery dataset. This presentation will showcase the progress achieved so far and will demonstrate the ability of 3D Slicer as a freely available software to manipulate CT scan imagery datasets with excellent prowess in digital disarticulation of skull or even stripping the cranial vault of brain encased within.

The project received an ethical exemption from the UCD Animal Research Ethics Committee (AREC) with approval code: AREC-E-20-21-Kilroy.

O13Investigating the potential of gelatin methacrylate (GelMA) hydrogels as a drug delivery platform for rat spinal cord injury

Ciara M Walsh^1,2; Jacek K Wychowaniec^3,4; Dermot F Brougham³; Dearbhaile Dooley^1,2

¹School of Medicine, Health Sciences Centre, University College Dublin, Belfield, Dublin 4, Ireland; ²Conway Institute of Biomolecular & Biomedical Research, University College Dublin, Belfield, Dublin 4, Ireland; ³School of Chemistry, University College Dublin, Belfield, Dublin 4, Ireland; ⁴AO Research Institute Davos, Davos, Switzerland

Spinal cord injury (SCI) is a complex challenge with limited reparative capacity after injury, ultimately leading to loss of sensory, motor, and/or autonomic function. Current gold-standard therapies do not tackle this issue and no curative therapy is available. Biomaterials are emerging as a promising treatment option to carry therapeutic factors for direct delivery to the injury site. This research aims to develop a hydrogel system for sustained and localised drug delivery in a preclinical SCI model. Gelatin methacrylate (GelMA) is a semi-synthetic material that has been used for therapeutic cell delivery in preclinical SCI, and thus we aimed to determine if GelMA hydrogels have the physical and biological properties suitable for use as an injectable drug delivery system. Physical properties of positively and negatively charged 3%–15% GelMA hydrogels were tested via hydrogel swelling assay and rheological measurements. Viability staining of BV2 microglial cells within each hydrogel was performed to assess in vitro cytotoxicity over 14 days (n = 3). Immunofluorescent staining of astrocytes and microglia in organotypic spinal cord slices cultured on GelMA was performed to assess ex vivo biocompatibility (n = 3). Finally, inflammatory marker expression in RAW264.7 macrophages was measured using qPCR and ELISA. Thus far, we have shown that the physical properties of GelMA hydrogels are within a biocompatible range. BV2 microglial cells exhibit greater survival in negatively charged versus positively charged GelMA across all hydrogel stiffnesses. Additionally, 5% GelMA induces an inflammatory phenotype in microglia/macrophages ex vivo as demonstrated by a significant reduction in microglial ramification (p < 0.05), which was not observed with 3% GelMA. Initial results also show that 3% GelMA does not induce a change in inflammatory marker expression after 48 h in culture. This demonstrates that negatively charged 3% GelMA hydrogels are biocompatible in vitro and ex vivo thus forming a suitable base for the development of a drug delivery platform for future SCI preclinical studies. Procedures involving the use of animals were approved by the Animal Research Ethics Committee at University College Dublin and the Health Products Regulatory Authority of Ireland in accordance with the European Union Directive 2010/63/EU and SI No. 543 of 2012.

O14Slow imaging with quicksilver: High-pressure mercury intrusion in archival dental tissues studied with backscattered electron scanning electron microscopy (BSE-SEM) and X-ray Microtomography (XMT)

Alan Boyde; David Mills

Queen Mary University of London, London, UK

Mercury intrusion under very high pressures is used to study the distributions of dimensions of pores in permeable solids. We noted that archival calcified tissue samples which had been tested to 750 bar were permanently stained, had therefore retained mercury, and decided to investigate whether this could be a valuable morphological space stain. 40 yBP porosimetry samples were embedded in poly-methyl-methacrylate. Blocks were cut and polished for imaging, uncoated, with 20 kV backscattered electron scanning electron microscopy (BSE-SEM): they were also imaged using X-ray microtomography (XMT) to study the 3D distribution of the mercury. Samples in this study included human bone, deciduous molars and permanent incisors, premolars and molars, rat upper and lower incisors, African elephant tusk dentine and cementum, and freeze-dried bovine teeth with immature enamel. In all the calcified tissues studied, small, unmineralized space compartments were brought into great prominence: in bone, osteocyte lacunae and canaliculi: in cementum, non-mineralised cores of Sharpey fibres and cementocyte lacunae and canaliculi, but we discovered previously unrecognised mineralisation defect zones in innermost primary acellular distal root cementum in human teeth. Dentine tubules were extremely marked and often showed an astonishing number of fine side branches at a size just below the resolution limit of conventional optical microscopy: their continuity across the enamel dentine junction with enamel tubules and spindles was clearly shown. Interglobular dentine zones in human dentine and incremental layering in elephant dentine were heavily impregnated. We obtained detailed information concerning the tubule curvature (odontoblast movement) pattern responsible for the beautiful chequer board arrangement in elephant tusk [which has led to the endangerment of the species]. In enamel, prism boundary discontinuities (‘sheaths’) were prominent in the known hypomineralisation tracts—tufts and lamellae—but also in developmental hypomaturation regions and ‘white spot’ caries. In rat incisor, defect non-mineralised zones were seen in innermost enamel. Because of the extreme high density and signal levels from Hg, both XMT and BSE-SEM demonstrate its presence at below their normal spatial resolution limits giving rise to apparently higher resolution.

Ethics statement: All samples studied antedated the UK Human Tissues Act 2004 and CITES regulations.

O15In vitro mock circulatory loop for testing and validation of novel medical devices for the treatment of heart failure with preserved ejection fraction (HFpEF)

Andrew Malone¹; Sean Gallagher²; Jemil Saidi¹; Gina Rizq^1,3; Enda O'Dowd²; Derek Vallence²; Aamir Hameed^1,4

¹Tissue Engineering Research Group (TERG), Department of Anatomy and Regenerative Medicine, Royal College of Surgeons in Ireland, Dublin, Ireland; ²Medical Device Design, National College of Art and Design, Dublin, Ireland; ³School of Medicine, RCSI University of Medicine and Health Sciences, Dublin 2, Ireland; ⁴Trinity Centre for Biomedical Engineering, Trinity College Dublin, Dublin, Ireland

Heart failure with preserved ejection fraction (HFpEF) is one of two main types of Heart Failure (HF). It is characterised by left ventricular ejection fraction (LVEF) of ≥50%. HFpEF makes up approximately 50% of the HF population, a number that is expected to rise in the coming decades. This is despite the estimated economic burden associated with HFpEF of $53.1 billion in the United States by 2030. The requirement for a robust in vitro testbed for HFpEF necessitates a dynamic two-chambered mock circulatory loop (MCL) which can be altered to limit diastolic filling of the left ventricle while maintaining a functional cardiac cycle. No in vitro testbed has been developed that can both mimic the cardiac cycle and features two independently controlled cardiac chambers. This work aims to present two new bench top MCLs which can mimic both healthy cardiac function and HFpEF conditions through the limiting of the diastolic relaxation. Two new MCLs are presented featuring: (i) cylindrical PVC chambers and (ii) soft silicone chambers which are anatomically analogous to the native heart. Compressed air is delivered at 120 mm Hg to each chamber via an electro-pneumatic regulator and each chamber is independently vented using a solenoid-operated valve. A series of non-return valves ensure unidirectional flow. HFpEF was simulated by limiting the amount of time that the left ventricle was vented for during the cardiac cycle from 350 to 150 ms. Pressure was measured using 24PCBFA6G gauge pressure sensors (Honeywell International Inc., USA). Chamber volume was determined indirectly using Doppler ultrasound. It was shown that both MCLs are capable of simulating the onset of HFpEF with a sustained increase in diastolic pressure of 22.03% and a sustained decrease in end-diastolic volume of 14.24%. The MCLs presented in this work are capable of simulating healthy heart function and can mimic varying severity of HFpEF. Both MCLs represent a key step forward in the development of a testbed for HFpEF treatments as well as having the potential for the simulation of other cardiac conditions.

O16Live cell imaging in the human oviduct: How cervical and endometrial cancer alter tubal morphology and function

Caoimhe Neville¹; Barbara Hughes¹; Kate Glennon²; Ann Treacy³; Donal J Brennan²; Sabine Kölle¹

¹Health Sciences Centre, School of Medicine, University College Dublin, Belfield, Dublin 4, Ireland; ²Department of Gynaecological Oncology, UCD School of Medicine, Mater Misericordiae University Hospital, Dublin 7, Ireland; ³Department of Histopathology, Mater Misericordiae University Hospital, Dublin 7, Ireland

To date, it has been established that the fallopian tube plays a key role in initiating the oncogenesis of high-grade serous ovarian cancer. However, alterations of tubal morphology and function in relation to cervical and endometrial cancer have not been elucidated yet. Therefore, the main goal of the study was to establish the effects of cervical and endometrial cancer on the microarchitecture and molecular function of the tubal epithelial cells using cutting-edge imaging technologies. For this purpose, tissue samples (0.5 cm) from fallopian tubes were obtained from patients with endometrial cancer (n = 6), cervical cancer (n = 3) and from controls (n = 9) immediately after ovariohysterectomy. In the first step, the tubal epithelium was analysed using live cell imaging in the ex vivo organ culture. In a second step, samples were embedded, sectioned, and stained with H&E and periodic acid Schiff reaction (PAS). Additionally, immunohistochemical localization of the tumour-promoting protein RHAMM (receptor for hyaluronan-mediated motility), the inflammatory protein COX-2 (cyclooxygenase-2), and leucocyte common antigen CD45 (cluster of differentiation 45) was performed. Our results showed that the tubal epithelial cells of cancer patients exhibited distinct morphological alterations within the epithelium as compared to controls. This included pleomorphism, irregular cell form and size, multivesicular structures in the cells, confluent areas revealing necrosis with loss of cilia, organelle breakdown, and lymphocyte infiltration. Glycoprotein synthesis in the endometrial cancer patients was significantly increased compared to controls (post hoc according to Dunnett, p = 0.0138). Fallopian tubes from patients with cervical cancer revealed significantly higher amounts of RHAMM in the epithelium (post hoc test according to Dunnett, p = 0.021). Furthermore, a significant decrease in CD45-positive cells was observed in the endometrial cancer as compared to controls (post hoc test according to Dunnett, p = 0.0285). Our results show that cervical and endometrial cancer significantly alter tubal cell morphology which might provide valuable insights for further improving staging and refining the prognosis. Moreover, this study points to the potential use of RHAMM in the fallopian tube as a biomarker for cervical cancers.

Ethical approval for this study was obtained from St. James's Hospital, the Mater Hospital and UCD (1/378/1645, 1/378/2140, LS-14-23 and LS-E-21-116).

O17Development of a 3D scaffold-based model of the fibroglial scar formed following spinal cord injury for therapeutic screening

Martyna Stasiewicz¹; Adrian Dervan¹; Fergal O'Brien^1,2,3

¹Tissue Engineering Research Group (TERG), Royal College of Surgeons, University of Medicine and Health Sciences, Dublin, Ireland; ²Trinity Centre for Biomedical Engineering, Trinity College Dublin, Dublin 2, Ireland; ³Advanced Materials & Bioengineering Research (AMBER) Centre, RCSI, Dublin 2, Ireland

Spinal cord injury is characterized by the formation of an inhibitory fibroglial scar by astroglial cells and invading meningeal fibroblasts around a lesion cavity in the injured cord. Biomaterial implants carrying therapeutics placed within the cavity to promote repair must overcome this potent barrier, but its removal enhances inflammation and expansion of the injury site. Therefore, we hypothesised that removing junctional protein connections between scar cells will promote the diffusion of therapeutics out of the scaffold implants and into the damaged tissue. To test this hypothesis, we aimed to develop a 3D gene delivery platform in which to test novel non-viral delivery of silencing RNA targeting the connexin43 junctional protein expressed by all scar cells. Using TERG's freeze-drying techniques, we fabricated scaffolds composed of hyaluronic acid (HyA) and incorporating trophic protein collagen IV (CollIV), both present throughout the spinal cord. The resultant porous scaffolds exhibited low stiffness and longitudinally aligned microarchitecture mimicking the physico-mechanical properties of the spinal cord. Seeded on the scaffolds, astrocytes and meningeal fibroblasts rapidly colonised the scaffold surface and exhibited elaborate morphologies typical of each cell type. Where the astrocytes and meningeal fibroblasts interfaced, a continuous barrier-like structure formed, replicating their normal in vivo organization. The interaction was also accompanied by changes in the deposition of extracellular matrix proteins fibronectin, collagen IV and laminin, also associated with in vivo barrier function. Administration of SCI-associated inflammatory cytokines induced scar-forming behaviours and upregulation of connexin43 protein in the scar-forming cells, validating this protein as a target for knockdown using RNAi technologies. In summary, this work outlines the development of a novel, 3D in vitro fibroglial scar model for use as a high-throughput platform to identify and test novel targets, such as connexin43 siRNA for more efficient therapeutic intervention in spinal cord injury.

O18Mandibular anatomy of early Glires (Mammalia) reveals a mixture of rodent-like and lagomorph-like characters

Łucja Fostowicz-Frelik¹; Philip G Cox²; Qian Li³

¹Institute of Paleobiology, Polish Academy of Sciences, Warsaw, Poland; ²Centre for Anatomical and Human Sciences, Department of Archaeology and The Hull York Medical School, York, UK; ³Key Laboratory of Vertebrate Evolution and Human Origins, Institute of Vertebrate Paleontology and Paleoanthropology, Chinese Academy of Sciences, Beijing, China

Glires (rodents, lagomorphs and their fossil kin) is the most speciose and arguably most diversified clade of placentals. The dental system of Glires consists of two highly independent functional modules: gnawing incisors and grinding cheek teeth. The large and ever-growing incisors of the second deciduous pair (coupled with loss of lingual enamel on them) are so characteristic of rodents and lagomorphs that the condition suggested the idea of Glires to Linnaeus, and is currently regarded as a major synapomorphy of Glires. The cheek teeth compartment in Glires is very variable. There is a basic dichotomy concerning the mechanics of mastication in Glires: in lagomorphs the movement is mostly transversal whereas in rodents, propalinal. We studied the mandibles in four representatives of the basal Glires from the Paleocene of China belonging to the duplicidentate (lagomorph-like) and simplicidentate (rodent-like) lineages to appraise diversity of early Glires mandible structure and mastication modes. The section modulus, a cross-sectional measure of bending strength, was calculated in the dorso-ventral and labio-lingual planes at the interdental gaps along the mandible. The mandible bodies differ in depth, curvature of the ventral margin, and the bending of the dental row, and the region where the maximum grinding force was likely applied (i.e. the region with the greatest section modulus). In the early Paleocene Mimotona lii the maximum grinding force was applied at the mid-molar segment (m1/m2), in a lagomorph-like manner, whereas in the middle Paleocene Mimotona robusta and Heomys orientalis it was shifted posteriorly at the back of the dental row (m2/m3), which corresponds to typically rodent pattern. Notably, in the late Paleocene Eomylus sp. the grinding force was distributed equally along the whole dental row; this specimen has also a very short lower incisor terminating not farther than the p4 (a lagomorph-like feature). Our results point to the early diversification of the mandible structure of Glires, a mixture of duplicidentate and simplicidentate characters among the basal Glires, and suggest an ancestral position of a lagomorph-like morphotype. This research was funded by National Science Centre (Poland) grant number 2015/18/E/NZ8/00637 to ŁFF. No ethical approval was required for this study.

FT1Exercise interventions for sarcopenia management: A review with an anatomical perspective

Hope Edwards¹; Huw Jones^1,2; Jamie Mosely³; Thomas Marshall³; Alison Briggs³; Sherif El-Khamisy^1,2,4; Myo Nyein Aung⁵; Matthew Farrow^1,6

¹School of Pharmacy and Medical Sciences, University of Bradford, Bradford, UK; ²The Institute of Cancer Therapeutics, University of Bradford, Bradford, UK; ³School of Allied Health Professions and Midwifery, University of Bradford, Bradford, UK; ⁴The Healthy Lifespan Institute and Institute of Neuroscience, School of Bioscience, University of Sheffield, Sheffield, UK; ⁵Advanced Research Institute for Health Sciences, Department of Global Health Research, Graduate School of Medicine, Jutendo University, Tokyo, Japan; ⁶Wolfson Centre for Applied Health Research, Bradford Institute for Health Research, Bradford, UK

The proportion of older people in the population is increasing from 727 million people older than 65 years in 2020 to an estimated 1.5 billion people worldwide by 2050. Skeletal muscles undergo changes due to ageing, including atrophy, myosteatosis, and changes in the molecular phenotype. Sarcopenia is a geriatric muscle disease characterised by the progressive loss of skeletal muscle, resulting in reduced muscle function and decreased quality of life. The primary risk factor for sarcopenia is ageing due to multiple age-related processes, including: loss of motor neurons and type II muscle fibres, anabolic resistance, reduced satellite cell function, low-grade inflammation, and hormonal changes. Interventions to improve muscle health to increase physical function and improve quality of life is of paramount importance. A lack of early diagnosis of sarcopenia increases the risk of immobility, disability, and the possibility of premature mortality; highlighting the need for effective early indicators and intervention to prevent disease progression and improve muscle health. Current treatment relies upon a progressive resistance training (RT) programme to promote muscle hypertrophy and improve physical performance, with a combination of RT and balancing activities shown to be the most effective intervention for reducing falls. RT has demonstrated its ability to upregulate protein synthesis and increase type II muscle fibre size. These adaptions increase the maximum muscle power production and improve physical performance, reversing the sarcopenic phenotype. However, RT struggles to retain participation rates due to its repetitive nature, is not appropriate for all patients, and is not integrated into geriatric medicine and social care. Alternative interventions to RT, including multi-modal training, low-intensity blood-flow restriction training and whole-body vibration training, should also be investigated, as should the personalisation of exercise prescription to develop effective treatments for sarcopenia. Understanding the changes in skeletal muscle anatomy induced by these exercise interventions is essential to understand their validity and utility as an intervention. To monitor the efficacy of these interventions, quality of life questionnaires, medical imaging, physical function assessments, and biomarkers should be utilised to provide a better insight into the effectiveness of exercise interventions on the muscle at an anatomical and molecular level.

FT2Anatomical considerations in the success of surgical management strategies in treating non-communicating hydrocephalus in paediatric patients

Fearghal Hosty-Blaney; Joe Quinn

Centre for Biomedical Sciences Education, School of Medicine, Dentistry and Biomedical Sciences, Queen's University, Belfast, Northern Ireland, UK

Hydrocephalus is a life-threatening condition resulting from an imbalance in the production and absorption of cerebrospinal fluid and can be caused by a range of pathologies including congenital membranes, tumours and inflammation of the ventricular system. Current management strategies for this condition have evolved to include Endoscopic Third Ventriculostomy (ETV), Endoscopic Third Ventriculostomy with Choroid Plexus Cauterisation (ETV with CPC) and various forms of shunting, with ventriculoperitoneal shunts (VPS) being the most common. The reported success rates of these methods, however, are varied throughout literature and implementation of one strategy over another is largely down to surgeon preference. This study reports the success rates of these management strategies in both surgically naïve and non-naïve patient groups, with a successful intervention being defined as one which does not require repeat surgical intervention or permit worsening symptoms of hydrocephalus after implementation. In surgically naïve patients ETV, ETV with CPC and VPS achieved average success rates of 56%, 58% and 64%, respectively, while in surgically non-naïve patients, ETV and VPS achieved average success rates of 59% and 74%, respectively. As can be seen from these results, VPS maintains its position as the gold standard for the treatment of hydrocephalus, however, there remains hope for patients seeking shunt independence through considered use of more novel management options. No ethical approval was required for this research.

FT3A preliminary class-wide study of comparative anatomy in the mammal scapula using 3D geometric morphometrics

Sophia C. Anderson; Philip G Cox; Eloy Gálvez-López

University of York, York, UK

The scapula (the shoulder blade) is a highly informative component of the mammalian skeleton thanks to its extensive role in forelimb function and weight-bearing. It is both part of the shoulder girdle attaching the forelimb to the body and being a functional element of the forelimb itself. As such, a better understanding of the functional morphology and the biomechanics of the scapula, and how these relate to forelimb use and ecology, is of great value. Scapular morphology is diverse across mammals, and understanding how this shape variation relates to the complex functional demands placed on the scapula in different animals with a variety of behavioural and locomotor ecologies will provide insight into the evolutionary plasticity of this skeletal element. Though the functional morphology of the scapula has been studied using various techniques in many mammalian taxa, as yet no single study has investigated the morphology of the scapula in 3D across the whole mammalian class. We are undertaking such a project and are now able to present preliminary results. We have designed a configuration of 72 landmarks (including both true and semi-landmarks) to capture the overall shape and anatomical features of the scapula. This configuration, which is repeatable across morphologically diverse mammalian taxa, has been used in a preliminary study containing one specimen from each currently recognized extant mammalian order (28 specimens). The results show a wide diversity in mammalian scapula shape and reveal links between scapular morphology and locomotor behaviour that have never before been demonstrated across the entire class, notably in the isolated spine and glenoid regions. The results are promising, firstly in that the proposed landmark configuration is applicable across the diversity of the mammalian scapula, and secondly, that informative trends can be identified in scapular morphology across such diverse taxa. Following the success of this preliminary work, we intend to continue this study at a higher resolution (including one specimen from every mammalian family and subfamily) in order to clarify further the form-function relationship in this skeletal element. No ethical issues were raised by this project, as no humans or live animals were included in it.

FT4Old meets new: Student perceptions of using anatomical drawing alongside digital 3D models

Emily Green; Kayleigh Scotcher

Newcastle University, Newcastle upon Tyne, UK

Drawing has been a cornerstone of anatomical education throughout history; anatomists such as Galen, Vesalius, Da Vinci and Carter are well known for their anatomical illustrations. It is a teaching approach that has been extensively implemented over the years and has been proven as an effective and engaging technique. Conversely, the use of 3D anatomy software is a much more modern approach that has been increasing in popularity more recently. It can be applied in a variety of ways for anatomy education and has also been shown to be effective in anatomy teaching by improving students' anatomical knowledge and awareness of spatial relationships. Improvements in technology mean 3D anatomy is more widely accessible than ever, and its efficacy and popularity mean it is likely here to stay. In this project, we bring together the historical method of teaching through drawing, with the modern approach of using 3D software. We developed an innovative teaching session that used a Complete Anatomy 3D model alongside a simultaneous drawing exercise to teach a challenging anatomical topic. We implemented our approach in a range of learning environments including large lectures, small group seminars, and as an asynchronous pre-recorded resource. We evaluated student perceptions of our method with a post-session Likert scale and free-text questionnaire. Free-text data were thematically analysed. Student responses were overall positive, and analysis of free-text feedback provided valuable insight into how we can enhance our approach for future sessions. Students found our approach useful in supporting their understanding of the topic, with many agreeing that they would like to see more of these sessions in future. Areas for improvement related to the pacing of the session, ensuring the 3D model is demonstrated with sufficient pauses to allow for students to observe the anatomy and add to their drawing. After this pilot, we hope to build on student responses to enhance our approach and develop a further study, investigating whether our approach improves anatomical knowledge and retention.

This project has ethical approval from Newcastle University Faculty of Medical Sciences Ethical Review Committee.

FT5Optogenetic Shroom3 in branching morphogenesis in 3D cell culture

Natalia Penar; Robyn D'Arcy-Evans

University of Edinburgh, Edinburgh, UK

Branching morphogenesis occurs in development of many internal organs, including kidneys and lungs. Tissue branching involves symmetry-breaking, causing some cells to become branch leaders while other cells remain in place. The symmetry-breaking process is not well understood. This project tested one hypothesis on branching formation, that mechanical curvature can directly influence branching, with convexity promoting and concavity inhibiting cell advance. Shroom3 protein drives actin to associate with myosin, and localises in the apical membranes of epithelial and endothelial cells. Thus, Shroom3 activation induces apical constriction and epithelial folding. In this project, Madin–Darby Canine Kidney (MDCK) cells with optically activated Shroom3 (OptoShroom) were used. Wild-type MDCK cells in 3D cultures undergo branching when treated with the hepatocyte growth factor (HGF). This project aimed to investigate, whether OptoShroom-containing MDCK cysts in 3D cultures would undergo branching without HGF, and due to OptoShroom activation with blue light (455 nm). Cell culture plates containing both wild-type and OptoShroom-containing cells were prepared and kept in darkness. At days 11–13 after the cultures were started, one plate of each cell type was illuminated with blue light, while the other remained in darkness. Images of illuminated cysts were taken before illumination and 24 h, 48 h, and 72 h after the start of illumination. The images of non-illuminated cysts were taken at corresponding times. At all imaging times, wild-type cysts had regular shapes and mostly single lumens. OptoShroom cysts developed multiple lumens and less regular shapes. Statistical analysis and comparison of images before and 72 h after illumination has indicated that OptoShroom cysts were elongating and their symmetry was breaking (p = 0.003 when compared to wild type and p = 0.08 when compared to non-illuminated OptoShroom, in which some symmetry-breaking could have occurred due to weak OptoShroom assembly in the dark). The results have been supported by a follow-up study. The branching was not as extensive as the one induced by HGF. Hence, Shroom3 might be responsible only for the initial stages of branching, with the extension involving other molecules. The outcomes also indicate that mechanical curvature might be a mechanism for branch formation, however, further studies are needed.

FT6COVID-19 and anatomy education: A systematic review

Ruth Mullan; Eva Sweeney

Queen's University Belfast, Belfast, Northern Ireland, UK

The pedological methods for anatomy have evolved over time but the COVID-19 pandemic has had an unprecedented and profound impact on how anatomy is taught. This review reports the findings of 34 anatomy education papers identified by a systematic literature search using EMBASE and MEDLINE databases. The papers were published between May 2020 and September 2021 from institutions largely in the USA, China and the UK, although many other countries were also represented. All institutions reported moving lectures online and the majority reported carrying out online practical sessions over the COVID-19 pandemic period. Institutions delivered teaching using both asynchronous and synchronous methods and used different software packages, most commonly Blackboard Collaborate, Zoom and Complete Anatomy. Only 4% of the institutions in this review carried out in-person dissection classes. Four studies reported that educators carried out in-person examinations and 13 studies reported that they carried out online examinations at the end of the academic year. Student feedback on the methods used to teach and examine anatomy over the COVID-19 pandemic period was generally positive. Seven papers reported that students liked the use of pre-recorded lectures as it allowed them to access this material at any time. However, students felt that they would prefer to return to face-to-face teaching for practical classes, stating that in-person dissection sessions were “irreplaceable.” Staff highlighted the pace of the transition to online learning and a limited workforce as issues that made this a stressful period and many of them were also keen to return to face-to-face teaching. Four papers, however, reported staff recognised that the materials and skills acquired over the pandemic period were useful for their professional development. This review summarises the information available to educators about the methods used by their peers across the globe to teach and examine anatomy during the COVID-19 pandemic. This is useful as online learning is likely to play a role in the short and long-term future of anatomy education as a blended learning approach continues in response to the ongoing COVID-19 pandemic and as part of massive open online courses.

Ethics statement: Ethical approval was not required for this review paper as it did not involve conducting primary research.

FT7Forward head posture and lower-limb joint moments in human gait

Guohao Lin¹; Tracey Wilkinson¹; Xiong Zhao²; Weijie Wang³

¹Centre for Anatomy and Human Identification, University of Dundee, Dundee, UK; ²School of Human Kinetics, University of Ottawa, Ottawa, Canada; ³Department of Orthopaedic and Trauma Surgery, University of Dundee, Dundee, UK

Forward head posture (FHP) is a common postural deviation in the sagittal plane. As sagittal spinal alignment plays an essential role in walking, changes in cervical alignment by FHP may affect normal gait, with reduced balance control observed in subjects with FHP. However, few studies have investigated the association of FHP with gait disorders. This study aimed to investigate whether there would be differences in sagittal lower limb joint moments between individuals with and without FHP. Thirty-six participants were recruited and grouped into the FHP group (n = 17) and non-FHP group (n = 19), based on a craniovertebral angle of less than 53 degrees, a common diagnostic criterion for FHP. Both kinematic and kinetic data were collected when participants walked at a self-selected speed. The data were filtered and imported into Visual 3D (C-Motion Inc., Germantown, MD) to create a biomechanical model and to calculate the hip, knee and ankle joint moment normalised by body weight bilaterally. The mean joint moments of the two groups were compared using a continuous waves analysis with statistical parametric mapping in MATLAB. Results showed that the right knee joint flexion moments (the dominant limb) in the FHP group were significantly lower (minimum and maximum, 0.04–0.23 Nm/kg) compared to the non-FHP group (0.17–0.40 Nm/kg) throughout the terminal stance phase (60%–80% of the right step) (p = 0.001), but there were no differences between the two groups in other joints or compared to the other side. This asymmetrical change in joint moments indicated that the dominant lower limb seemed more sensitive to this postural deviation. The reduced flexion moment of the right knee joint may be used to maintain the stability of the whole body in gait. However, this reduced flexion moment would change the knee flexion-extension moment ratio, causing knee joint instability during terminal stance. Future studies should investigate agonistic/antagonistic muscle activity and passive soft tissue resistance, which generates the internal moments. Ethical approval was obtained, and informed consent was received from all participants.

FT8Do age-related differences in healthy CBA and osteoarthritic STR/Ort mouse tibias show future imaging biomarkers?

Lucinda Evans^1,§; Eva Herbst^2,§; Alessandro Felder³; Sarah Ajami⁴; Behzad Javaheri⁵; Andrew A Pitsillides¹

¹Skeletal Biology Group, Comparative Biomedical Sciences, Royal Veterinary College, London, UK; ²Paleontological Institute and Museum, University of Zurich, Switzerland; ³Research Software Development Group, University College London, London, UK; ⁴University College London Great Ormond Street Institute of Child Health, London, UK; ⁵City University of London, London, UK

Novel imaging biomarkers are required to advance research into, and treatment of, knee joint osteoarthritis (OA). Early-stage OA is undetectable in humans, and treatment effectiveness cannot be reliably monitored. STR/Ort mice are an age-related model of progressive OA, in which predisposition (at 10 weeks of age), early-stage onset (at 20 weeks), and late-stage OA (at 40 weeks) are well-defined. Using STR/Ort (OA) and CBA (healthy parental control strain) mice at these age intervals, knee joints were non-invasively μCT imaged with effective pixel size of 5 μm. Tibial epiphyses were semi-automatically segmented from knee joints and separated into their constituent anatomical components: cortical bone, trabecular bone, and marrow space volume. These bony features can be detected in human knees using clinical in vivo scanners (XtremeCT II HR-pQCT, Scanco Medical) making the ranslation of our research realistically attainable in the near future.

3D analyses of tibial epiphyses followed by two-way ANOVA confirmed significant age- and/or strain-related differences in epiphyseal cortical bone volume (p ≤ 0.001), trabecular bone volume (p ≤ 0.001), mean trabecular and cortical bone thicknesses (both p-values ≤0.010), trabecular volume relative to cortical volume (p ≤ 0.001), and degree of anisotropy, a descriptive measurement of trabecular 3D organisation (p = 0.001).

The two mouse strains had different epiphyseal growth patterns throughout life with respect to total epiphyseal volume (p = 0.023); marrow space volume (p = 0.002); and trabecular volume relative to epiphyseal interior volume (p = 0.024), as well as changes in trabecular anisotropy indicating divergent age-related interactions in these two mouse strains.

Our findings disclose new imaging biomarkers of pre-OA, OA onset and OA progression in the STR/Ort mouse, an established animal model of spontaneous age-related OA. Due to our exploitation of only gross-anatomical features in the tibial epiphysis, which can also be segmented from clinical CT scans, we anticipate future translation of this promising research into human clinical practice.

Ethical approval for animal procedures was carried out in accordance with the Animals (Scientific Procedures) Act 1986, an Act of Parliament of the United Kingdom, approved by the Royal Veterinary College Ethical Review Committee and the United Kingdom Government Home Office under specific project license.

^§Equal contribution.

FT9Histological and molecular assessment of adipose tissue health and its correlation with glomerular damage in the Zucker Diabetic Sprague Dawley (ZDSD) rat model of diabetic kidney disease

James White^1,2; Yeong Huei Desmond Chuah²; Mahmoud Abdelaal³; Carel W le Roux²; Neil G Docherty^1,2

¹Department of Anatomy, School of Medicine, University College Dublin, Dublin, Ireland; ²Diabetes Complications Research Centre, University College Dublin, Dublin, Ireland; ³Plastic Surgery Department, Assiut University, Assiut, Egypt

Pathological changes in adipose tissue (AT) arising during the progression of type 2 diabetes mellitus (T2DM) have been implicated in end-organ damage through changes in the levels of circulating metabolites and remote-acting adipocytokines. Adiponectin is a key adipocytokine involved in a putative adipose-renal axis mediated in part by the expression of adiponectin receptors on glomerular podocytes. Adiponectin receptor knockout mice develop renal damage similar to that observed in early diabetic kidney disease (DKD). We sought to characterize AT morphological change and adiponectin gene expression in T2DM progression using a Zucker Diabetic Sprague Dawley (ZDSD) rat model, and to assess whether changes in these parameters correlated with structural changes in the glomerulus. Epididymal fat pad visceral AT and renal cortex were obtained from male ZDSD rats (n = 32) euthanized at 26, 32 and 38 weeks of age to obtain a spectrum of T2DM severity. AT was processed for histological and qPCR analysis, and renal cortex was processed for transmission electron microscopy. Measurement of adipocyte diameter, podocyte foot process (PFP) frequency, PFP diameter and glomerular basement membrane (GBM) thickness were performed with ImageJ. Urinary albumin excretion was measured in a 16-h time collection. Ten animals progressed to prediabetes (blood glucose 7–11 mmol/L), and eight animals progressed to diabetes (blood glucose >11 mmol/L). Diabetic animals presented increased urinary albumin excretion. Adiponectin gene expression was significantly decreased in diabetic animals and correlated with reductions in adipocyte diameter (r: 0.69, p < 0.0001). A negative correlation between adiponectin gene expression and GBM thickness was noted (r: −0.72, p = 0.02). These association-based data emphasise the potential mechanistic role for a disrupted adipose-renal axis as a contributor to DKD progression.

All experiments were carried out with the approval of the University College Dublin Animal Research Ethics Committee following the guidelines of the EU Directive 2010/63/EU for the protection of animals used for scientific purposes.

FT10The anatomical course of the azygos vein and its relationship to the thoracic duct: A human cadaveric observational study

Hannah Bridgwater; Lauren Hector; Cecilia Brassett

Department of Physiology, Development and Neuroscience, University of Cambridge, Cambridge, UK

Anatomical texts describe the azygos vein (AV) as being typically located to the right of the vertebral column. However, cadaveric dissection has shown that it is more commonly found in the midline or to the left of the vertebral column. The thoracic duct (TD) has been observed to always be located to the left of the AV, regardless of its anatomical course. The relationships of these two structures are important during thoracic surgery, as they must be identified and protected from injury. This study aims to determine if: (a) the AV is more commonly located to the left of the vertebral column, and (b) the TD always lies to the left of the AV.

The posterior mediastinum of 18 cadaveric donors in the Human Dissection Room, University of Cambridge, was explored. The distance of the AV from the midpoint of four thoracic vertebrae was measured in cm. The site of the TD in relation to the AV was noted. Of the donors dissected, 12 were male and 10 were female, with a mean age of 86.64 years. The termination of the AV arch was found to be at T4, T5 and T6 in 2, 13 and 3 donors, respectively. None of the AVs were completely on the right of the vertebral column, with 6 crossing the midline and 13 entirely on the left or on the midline at only one vertebral level. In all 8 donors where the TD was positively identified, they lay to the left of the AV. In conclusion, our study confirmed the anecdotal observation that, unlike conventional descriptions, the AV was not found in the right but predominantly located to the left of the vertebral column. Thoracic surgeons should be aware of this when operating in the posterior mediastinum. Statement of ethics: All donors had provided written consent before decease for their bodies to be used for anatomical teaching and research after death, in compliance with the Human Tissue Act 2004.

FT11Analysing growth of the human foetal scapula using geometric morphometrics

Thomas O'Mahoney

Anglia Ruskin University, Cambridge, UK

Understanding normal scapula growth during gestation is important for early detection of potential anomalies in order to plan effective clinical interventions. This pilot project started to evaluate normal growth of the human scapula through later stages of gestation (4–9 months in utero) using 3D geometric morphometrics (GMM).

Surface scans were taken of 39 non-pathological 19th-century human foetal left scapulae held at the University of Liverpool, using a Polyga HDiR3 scanner in macro mode (resolution 35 microns). The resulting scans were semi-automatically landmarked using the ALPACA function in Slicermorph, whereby a template scapula had 71 type 1, 2 and 3 landmarks digitised and these were automatically applied to the rest of the sample. The resulting landmark dataset was subjected to generalised procrustes analysis followed by principal components analysis and vanonical variate analysis (CVA) in MorphoJ. The first three principal components (PCs) account for 58.6% of shape variation. CVA revealed a good separation in shape between the three age groups (4–5, 6–7, and 8–9 months).

PC1 demonstrated that shape variation is driven by rotation of the scapular spine, with the earliest group showing the most elevated angle relative to the scapula superior and inferior angles. PC2 shape variation was driven mostly by rotation of the glenoid relative to the scapula body. The functional significance of this is most probably linked to increasingly organised patterns of muscle ‘lay down’ as foetuses approach full term.

Further work will aim to improve sample sizes for the earlier age groups and add younger individuals to further elucidate early patterns of scapular growth and to confirm results from this pilot study.

Ethical approval for this research was given by the Anglia Ruskin School of Life Sciences Ethics panel approval number BS SREP21-112.

FT12An investigation to assess if stretch forces influence stemness of the temporomandibular joint disc in mice

Sneha Chotaliya^1,2; Natalie Milmoe²; Neal Anthwal²; Abigail Tucker²

¹NHS, London, UK; ²Centre for Craniofacial and Regenerative Biology, Faculty of Dentistry, Oral and Craniofacial Sciences, Guy's Hospital, King's College London, London, UK

Temporomandibular joint (TMJ) disorders are relatively common yet have few available therapies beyond surgery. Harnessing developmental programs may provide better, and less invasive therapies, however, these pathways are poorly understood in the TMJ. There is a particular paucity of data surrounding the effect of force on TMJ development, especially as experiencing, and responding to force is inherent to TMJ function.

We aimed to assess whether forces and stretch can influence stemness of the temporomandibular joint (TMJ) disc and condylar. For this Gli1, a marker of mesenchymal stem cells in the tooth and sutures, was used as a readout. The TMJ condylar and disc were dissected from late embryonic Gli1creERT2;tdTomato reporter mice. Cells were dissociated and cultured under a biaxial stretch of 5 mm over 24 h. Presence of Gli1 lineage cells were detected by red fluorescence protein at different time points of the stretch assay. After stretch culture, we performed immunohistochemistry for markers of cartilage/fibrocartilage cells and matrix proteins, including phalloidin, type II collagen, alpha-smooth muscle actin, Lubricin, and FSP1. These markers were compared against un-stretched control cells, as well as un-dissected tissue from mice at E15.5 and E18.5, and postnatal time points. Stretch-induced changes in protein expression suggesting a role of mechanical force in TMJ tissue development.

All research on mice was carried out under the appropriate licences from the UK Home Office and was approved by the King's GMO committee.

O19Asymmetric variation of the human digastric muscles: Case report

Rhiannon Robinson^1,2; Alexandra Masullo¹; Kevin Galinat¹; Dustin Lin¹; Seh Hong Lim¹

¹MGH Institute for Health Professions, Boston, Massachusetts, USA; ²Boston University School of Medicine, Boston, Massachusetts, USA

The asymmetric variations of the digastric muscle have a significant impact on head and neck surgery. A 99-year-old female cadaver with severe kyphosis and scoliosis was found to have multiple asymmetric variations of her digastric muscle. The anterior digastric muscle featured a duplicated accessory belly bilaterally, with corresponding duplicated mylohyoid nerve innervation. While having a normal right posterior digastric belly, the left posterior digastric consists of two divergent bellies, in which one normal belly inserting into the mastoid process and an additional belly merging with the stylohyoid muscle to insert into the styloid process. Variations of the digastric muscle are uncommon and sparsely characterized in literature, especially the posterior digastric belly. As the digastric muscle bellies each arise from different pharyngeal arches, it is surprising to find contralateral and differing abnormalities between each belly. It is unknown if the patient experienced symptoms related to her variations. The triangles of the neck formed by these digastric muscle bellies are clinically important as the skewing or shifting of the boundaries can lead to surgical disorientation. This anomalous anatomy can also be mistaken for tumors or swollen lymph nodes during the palpation of the carotid and submental triangles, resulting in perhaps unnecessary treatment. On the other hand, provided that both bellies are functional and innervated separately, the accessory anterior digastric muscle bellies may be harvested for facial reconstructive surgeries with minimal compromised masticatory function.

The procedures and protocols for this study were reviewed and approved by the Office of General Council at Harvard University.

O20Acetabular labrum entheses and cortical bone microdamage in relation to grades of hip joint osteoarthritis: A human cadaveric study

Abdulaziz A Alomiery^1,2; Andrew C Hall³; Thomas H Gillingwater¹; Alsolami Afaf⁴; Abduelmenem Alashkham¹

¹Anatomy, Edinburgh Medical School: Biomedical Sciences, College of Medicine and Veterinary Medicine, University of Edinburgh, Edinburgh, UK; ²Prince Sultan College for Emergency Medical Services, Basic sciences department, King Saud University, Riyadh, Saudi Arabia; ³Edinburgh Medical School: Biomedical Sciences, College of Medicine and Veterinary Medicine, University of Edinburgh, Edinburgh, UK; ⁴Prince Sultan Military Medical City, Riyadh, Saudi Arabia

Fibrocartilaginous entheses are largely avascular structures that dissipate mechanical stress and provide bone protection. Labral attachment to bone has two attachment zones, inner (near-articular surface, i.e., the load-bearing zone) and outer (near-capsule, i.e., the stress-shielded zone). These attachment zones differ in strength and compactness based on their fibrocartilaginous entheseal morphology. Microanatomical differences in labral entheses between these zones and in relation to hip joint osteoarthritis (OA) remains unknown. This study aimed to investigate the prevalence of entheseal and cortical bone (CB) damage by fibrovascular channels and nerves (FVC-N) across entheseal zones and regional grades of hip joint OA. Sixteen cadaveric hips (mean age 80) were obtained from Anatomy, University of Edinburgh. The acetabulum including labrum, fibrous capsule and articular cartilage was divided into 8 regions providing 126 histological sections. Safranin O staining was used to perform histological assessment of entheseal structure and regional grading of hip joint OA. Immunohistochemical staining of blood vessels and sensory nerves was performed using antibodies against alpha-smooth muscle actin and low-affinity nerve growth factor. The FVC-N were categorized based on their damage to the CB into fully penetrating or only eroding CB. The inner entheseal zone showed more compact labral fibres with well-defined fibrocartilaginous morphology. The outer zone showed less-organized labral fibres with faint to absent fibrocartilaginous morphology. FVC-N penetrations and erosions were identified in 75% of cases. In the inner zone, the prevalence of penetrating and eroding FVC-N was 10% and 11%, respectively, whilst in the outer zone the prevalence was 54% and 75%, respectively. Penetrating FVC-N was seen in low, medium and high-OA grades in 19%, 28% and 18%, respectively. Eroded FVC-N were observed in low, medium and high-OA grades in 30%, 32% and 23%, respectively. The findings show that FVC-N of labral entheses can occur widely throughout the elderly population across all grades of hip joint OA. Prevalence of FVC-N was higher at outer zone entheses. The outer zone has a weaker attachment configuration: this is due to the presence of less-defined fibrocartilaginous entheseal morphology and higher prevalence of entheseal and CB microdamage. Cadaveric specimens used were obtained from Anatomy, University of Edinburgh, which is regulated by Human-Tissue (Scotland) Act 2006.

O21Analysing murine neuroblastoma xenografts for their extracellular matrix organisation to develop a novel 3D cell culture model

Ronja Struck^1,2,3; Olga Piskareva^1,2,3,4

¹Cancer Bio-Engineering Group, Department of Anatomy and Regenerative Medicine, RCSI University of Medicine and Health Sciences, Dublin, Ireland; ²School of Pharmacy and Biomolecular Sciences, RCSI, Dublin, Ireland; ³Tissue Engineering Research Group, Department of Anatomy and Regenerative Medicine, RCSI, Dublin, Ireland; ⁴National Children's Research Centre, Our Lady's Children's Hospital, Crumlin, Dublin, Ireland

Testing immunotherapies for neuroblastoma effectively requires a model that accurately portrays the tumour microenvironment (TME) present in vivo. To this end, it is vital to establish what properties the TME possesses that need to be portrayed. Aside from the cells populating it, the extracellular matrix (ECM) lends the TME its biomechanical properties. These properties have been shown to affect the cancer and linked to its severity. Thus, the constituents of the neuroblastoma ECM ought to be investigated to determine an appropriate model. Here, we will look specifically at collagen architecture and organisation and the glycoprotein abundance and distribution in neuroblastoma xenografts. The ECM constituents of patient-derived xenografts (PDX) and cell line-derived xenografts (CDX) will be analysed and compared to potential 3D models. Staining with Picrosirius Red collagen in the ECM will be visualised using brightfield, polarised light and fluorescent light microscopy to investigate collagen fibre organisation and patterns. FibrilTool and FiJi will be used to determine anisotropy, width, length, density and an established list of further features of collagen fibres. Alcian Blue will be used to grade the distribution and abundance of glycoproteins. By determining the biomechanical properties and glycoprotein content of the xenografts they can be characterised and compared to properties of existent neuroblastoma models. Based on those results, a three-dimensional cell culture model will be chosen and potentially modified to carry out immunotherapeutic testing on. Specifically, further experiments are targeted at evaluating which antibody activates antibody-dependent cellular cytotoxicity to eradicate cancer cells most effectively with the least severe side effects. But these results will not only be essential in choosing the right model for immunotherapeutic investigations but also identify differences in the different types of neuroblastoma models' ECMs. Determining how the ECM between PDXs, CDXs and 3D collagen scaffolds differ may elucidate how previous investigations were flawed by the choice of model and how the choice of model affected the results. This characterisation of neuroblastoma ECM will thus be essential to future neuroblastoma research reliant on accurate TME representation. Neuroblastoma patient samples for establishing PDXs were obtained with informed consent via Children's Oncology Group protocols that were approved by the USA NIH central (national) IRB, the TTUHSC IRB and the IRBs of institutions caring for the patients. Growth and harvesting of PDXs were carried out at TTUHSC under a protocol approved continuously by the TTUHSC Institutional Animal Care and Use Committee (IACUC) since 2009 and approved at the time of these studies. TTUHSC IRB Protocol # L09-041, the most recently approved on 23 September 2020. This research protocol for use of vertebrate animals in the Ewald Lab (MO20M234) was reviewed and approved by the Johns Hopkins University Animal Care and Use Committee on 27 July 2020.

O22A quantitative analysis of craniofacial dysmorphology in anterior synostotic plagiocephaly patients using computed tomography

Nivana Mohan; Lelika Lazarus; Anil Madaree; Rohen Harrichandparsad

University of KwaZulu-Natal, Durban, South Africa

Anterior synostotic plagiocephaly (ASP) is caused by the premature fusion of one coronal suture, which results in severe craniofacial asymmetry that can be challenging to correct. The various methods of surgical procedures, as well as the distinctive facial characteristics of ASP, have been well documented. However, there is a paucity of literature pertaining to the quantitative analysis of the craniofacial features that are affected in ASP. This study used preoperative computed tomography (CT) scans to document and compare the morphometry of the anterior cranial fossa (ACF), orbit, and ear on the ipsilateral (synostotic) and contralateral (non-synostotic) sides in a select South African population of patients diagnosed with ASP. The dimensions of the ACF, orbit and the position of the ear on the ipsilateral and contralateral sides were measured using a set of anatomical landmarks on two-dimensional CT scans of 18 consecutive patients diagnosed with isolated and nonsyndromic ASP at a regional hospital in South Africa between 2004 and 2020. The differences between the ipsilateral and contralateral sides were computed and expressed as a percentage of the contralateral side. The findings of this study revealed that there was side-to-side asymmetry in the ACF, orbit, and ear. All ACF parameters significantly decreased on the ipsilateral side when compared to the contralateral side, resulting in the volume of the ACF being the most affected (−27.7%). In terms of the orbit, on the ipsilateral side, the length-infraorbital rim (IOR), height, and surface area parameters significantly increased, with the height being the most affected (24.6%). The remaining orbital parameters (length-supraorbital rim (SOR), breadth and volume) significantly decreased, with the length-SOR parameter being the most affected (−10.8%). The ipsilateral ear was displaced anteriorly (9.33 mm) and caudally (5.87 mm) from the contralateral ear. These measurements may be useful to surgeons during corrective surgery by indicating the degree of the asymmetry on each side, making it easier to plan the technique and extent of surgical correction of the affected craniofacial features. Ethical clearance for this study was obtained from the Biomedical Research Ethics Committee of the University of KwaZulu-Natal (UKZN) (BREC/00002129/2020).

O23On the morphology of the human semitendinosus muscle in legs with and without distal tendon harvesting

Adam Kositsky^1,2; Huub Maas³; Rod S Barrett¹; Ben Kennedy^1,4; Lauri Stenroth²; Rami K Korhonen²; Chris J Vertullo^1,5; Laura E Diamond¹; David J Saxby¹

¹Griffith Centre of Biomedical and Rehabilitation Engineering (GCORE), Menzies Health Institute Queensland, Griffith University, Gold Coast, Queensland, Australia; ²Department of Applied Physics, University of Eastern Finland, Kuopio, Finland; ³Department of Human Movement Sciences, Faculty of Behavioural and Movement Sciences, Amsterdam Movement Sciences, Vrije Universiteit Amsterdam, Amsterdam, The Netherlands; ⁴Mermaid Beach Radiology, Gold Coast, Queensland, Australia 5Knee Research Australia, Gold Coast, Queensland, Australia

Being comprised proximal (ST_prox) and distal (ST_dist) muscle compartments split by a tendinous inscription (TI), the human semitendinosus contains a peculiar design for an extremity muscle. Semitendinosus compartment morphology and function have been widely assessed in other mammals, but scarcely in healthy adults. Further, the distal semitendinosus tendon is commonly used as graft tissue for anterior cruciate ligament reconstruction (ACLR), resulting in severe morphological changes to semitendinosus. However, the spatial distribution of atrophy across semitendinosus compartments post-ACLR remains unknown. In this study, magnetic resonance images were obtained from 10 patients who had undergone ACLR with a distal ST tendon graft 8–18 months prior. Volume, maximal anatomical cross-sectional area (ACSA_max), and length were compared between compartments and legs, as were the locations of ACSA_max and TI endpoints (relative to muscle length). Volume, ACSA_max, and length were all smaller on the ACLR compared to contralateral leg. On the contralateral leg, ST_dist had significantly greater volume and length compared to ST_prox. On the ACLR leg, no between-compartment differences for volume and length were found, implying a larger difference in volume and length of ST_dist compared to ST_prox after ACLR. ACSA_max did not differ between compartments on either leg. The TI endpoints were generally located around the ACSA_max of each compartment, although the distal TI endpoint was slightly distal to ST_dist ACSA_max on the ACLR leg. The homogenous radial atrophy suggests the larger loss of volume in ST_dist compared to ST_prox after ACLR is due to greater shortening of ST_dist. Further, as semitendinosus is fusiform, its ACSA_max is a good proxy for the maximal force it can produce (physiological cross-sectional area). Therefore, no between-compartment differences in ACSA_max suggest the maximal force-producing capacity of compartments does not differ. Additionally, the TI is generally positioned between the ACSA_max of compartments provides a wide area over which the TI can mechanically interact with the two compartments. Overall, these results suggest the two ST muscle compartments function together mechanically in-series, although further work is needed to clarify the reasons for this muscle design.

The study was approved by the Griffith University Human Research Ethics Committee (2018/839).

O24Brainstem astrocyte Kir4.1 potassium channel expression in the rat TgF344-AD model of Alzheimer's disease

Poppy Froggett¹; Sanawor Hussan¹; Stuart Allan²; Adam Greenstein²; Andrew Robinson²; John Gigg²; Virginia Hawkins¹

¹Manchester Metropolitan University, Manchester, UK; ²University of Manchester, Manchester, UK

The retrotrapezoid nucleus (RTN) is a key brainstem locus for central respiratory control. Chemosensitive neurons in the RTN have been shown to be intrinsically sensitive to changes in CO₂/H+ and to regulate breathing in a CO₂/H+-dependent manner. However, astroglial cells also contribute to RTN chemoreception by providing a CO₂/H+-dependent purinergic drive that enhances neural activity, likely via a mechanism involving the inhibition of Kir4.1 channels. We recently found that an inducible astroglial cell-specific Kir4.1 potassium channel knockout mouse had reduced breathing responses to hypercapnic conditions, demonstrating that Kir4.1 channels are important mediators of central chemoreception and respiratory control. Kir4.1 expression or activity in animal models has also been shown to be reduced in various pathological conditions including epilepsy, Alzheimer's disease (AD), amyotrophic lateral sclerosis, and Huntington's disease. Furthermore, respiratory dysfunction has been implicated in the progression of such neurodegenerative disorders. We assessed respiratory brainstem Kir4.1 expression levels using immunohistochemistry and qPCR in both young adult (2–3 months) and aged (9 months) rodent AD transgenic model tissue. Our preliminary findings show Kir4.1 expression levels in astrocytes (Aldh1L1+ astroglial cells) were significantly higher in the RTN compared to hippocampal regions, as well as being significantly increased in aged tissue. Interestingly, Kir4.1 levels were consistently greater in female tissue compared to male tissue. Furthermore, astrocyte Kir4.1 expression levels were lower in aged TgF344-AD RTN tissue than in TgF344-WT controls. These findings did not appear to be restricted to cell bodies as preliminary data suggests Kir4.1 expression is also reduced at perivascular astrocyte end feet in the TgF344-AD RTN. This data demonstrates that altered Kir4.1 expression in neurodegenerative disease is not restricted to upper brain regions but may also be apparent in brainstem respiratory nuclei where it is involved in chemosensation and ventilatory drive. This supports the hypothesis that astrocyte contributions to respiratory control may become compromised with age, in a manner that leads to respiratory dysfunction in neurodegenerative disorders.

Full institutional ethical approval was obtained from Manchester Metropolitan University, and all procedures were carried out in accordance with the Animals (Scientific Procedures) Act, 1986. Funded by Manchester Academic Health Science Centre.

O253D virtual reality: A valuable tool for anatomical education

Sven Reese¹; Lisa Kopbauer¹; Tobias Klein¹; Sabine Kölle²; J. Maierl¹

¹Institute of Anatomy, Histology and Embryology, School of Veterinary Medicine, LMU Munich, Munich, Germany; ²School of Medicine, University College Dublin, Belfield, Dublin, Ireland

Comprehensive understanding of anatomy is only achieved by the inception of the 3D structure of the specimens. However, complete 3D datasets for domestic animals are still lacking.

Therefore, we set out to establish a 3D-scanning project for veterinary anatomical specimens. For this purpose, three different 3D scanners were used: the Artec Micro (for specimens <8 cm), the Artec Space Spider (for specimens <35 cm), and the Artec Leo (for specimens >35 cm) (Artec 3D, Santa Clara, USA). The data of the scans were transferred to virtual 3D objects using the software Artec Studio 15. Compression to a web-friendly format was achieved by using Blender 2.9 (www.blender.org). To date (May 2022), 700 3D scans from horse, donkey, cow, sheep, goat, pig, dog, cat, mink and chicken have been obtained, which cover all bones, all organs (including scans of each single tooth), the musculoskeletal system and selected abdominal topographic preparations (total size: 1.5 TB, item size: 1.4–10 GB). The smallest scanned bone is the penis bone of the cat, the largest bone is the cranium of an Indian elephant. Labelling using annotations details the name of the single structures and provides additional explanations. The 3D scans stand out by high granularity and high similarity to the natural surface texture and colour. The 3D pictures are rotatable and can be magnified using a smartphone or a computer. Additionally, technical colour coding and x-ray simulations of each model can be viewed. Worldwide free access to the virtual 3D objects has been granted via the platform Sketchfab (https://sketchfab.com/vetanatMunich). 220,000 views have been reported to date (May 2022).

In summary, the present collection of 3D scans provides valuable datasets for 3D printing of precious specimens and is an invaluable tool for both students and professionals. The scans can be used both for the teaching of students and for the medical training of veterinarians in virtual reality (VR) workstations by using multi-projected environments simulating a user's physical presence in a virtual environment.

O26Digitalising anatomy assessments: Dental students' perceptions of 3D and cadaveric spotters

Hannah Swainson¹; Kejal Kevat²; Iain D Keenan²; Joanna Matthan³

¹School of Medical Education, Faculty of Medical Sciences, Newcastle University, Newcastle, UK; ²School of Biomedical Sciences, Faculty of Medical Sciences, Newcastle University, Newcastle, UK; ³School of Dental Sciences, Faculty of Medical Sciences, Newcastle University, Newcastle, UK

On-site, cadaveric spotter examinations have long been a method of assessment within anatomical education. Higher student intake, reduced staff time and a paucity of skilled staff to dissect prosections means it is increasingly challenging to use this approach. The conversion of these assessments to an online format could reduce staff time spent pinning structures and marking examinations, free up the dissecting room for other teaching and allow all students to sit the examination simultaneously. The aim of this study was to glean student perceptions relating to digital spotters using either digital cadaveric images or 3D non-cadaveric images. Dental (BDS) and Oral and Dental Health Science (ODHS) students' perceptions were sought through a questionnaire following two practical sessions utilising formative spotters in the Dissecting Room (DR). A 3D commercial non-cadaveric anatomical model and an in-house digital cadaveric image were included as two additional stations in otherwise fully cadaveric spotters. A Likert-type scale, with free-text space to investigate experiences of the digital approaches, was utilised in the initial questionnaire (n = 47). A focus group (n = 5) explored perceptions in more depth. Students felt it was easier to identify structures and answer questions using the commercial anatomy software screens than the in-house digital spotter; however, the in-house spotter was easier to navigate. Neither digital modality was perceived as being more beneficial to their learning than using cadaveric specimens. 62% of students felt they would benefit from moving to online spotters due to the flexibility in accessing the assessment and the immediacy of results. However, there was some hesitancy due to the technological requirements, probity concerns and the limited amount of tactile feedback essential for a practical career. Dental and therapy students' perceptions of the digital spotter format are generally positive. This paves the way for the creation of bespoke digital spotter assessments containing 3D images developed from in-house cadaveric specimens. Coupled with sound solutions to mitigate against assessment irregularities, digital spotters may alleviate many of the challenges in anatomy assessment, whilst simultaneously being acceptable to the student body. This study was approved by the Faculty of Medical Sciences Ethics Committee at Newcastle University 03/2020 (1844/18438/2019).

O27Developing a novel three-dimensional brainstem neuroanatomy teaching application using cadaveric specimens

Rahul Shah; Susan Jones; Richard Adams

Department of Physiology, Development & Neuroscience, University of Cambridge, Cambridge, UK

Neuroanatomy teaching has benefited in recent years with the integration of computer-assisted learning (CAL) into the curriculum, helping to make this traditionally challenging subject for medical students easier to grasp. This project has aimed to produce a 3D-CAL neuroanatomy learning tool in the form of an educational application, using innovative methods of 3D computer graphic generation and based on cadaveric specimens. The tool is focused on the human brainstem, a functionally and clinically important brain structure. A brainstem was dissected from a cadaveric whole brain, and then two different methods were used to create a high-resolution 3D digital representation: photogrammetry, which involves the generation of a 3D digital object from many 2D images of the object, and 3D scanning, which uses a handheld 3D scanner compatible with specialist software. After processing, the digital 3D brainstem representation from the 3D scanner was integrated into an interactive virtual learning application. The final output of the project is to date a ‘proof-of-concept’ application that combines the realism of cadaveric specimens with 3D model interactivity. Approval for the use of a human cadaveric specimen was granted by the University of Cambridge's Human Anatomy Centre; the donors had given consent to the use of their body tissue for research and teaching in accordance with the Human Tissue Act, 2004.

O28Anatomical basis of intracranial meningiomas referred for preoperative embolisation: A retrospective chart review

Ezra Earl Anirudh¹; Vensuya Bisetty¹; Rohen Harrichandparsad²; Lelika Lazarus¹

¹Department of Clinical Anatomy, College of Health Sciences, University of KwaZulu-Natal, Durban, South Africa; ²Department of Neurosurgery, Inkosi Albert Luthuli Central Hospital, Durban, South Africa

Meningiomas are generally benign, highly vascularised, slow-growing tumours arising from the arachnoid cap cells of the arachnoid villi. The clinical presentation of these tumours is usually location-dependent due to the vast expanse covered by the meninges. Multiple meningiomas represent less than 10% of diagnosed meningiomas and may form simultaneously or at different times. Resection of a meningioma is generally performed after preoperative embolisation. A feeder vessel is selected and embolised in an attempt to reduce excessive blood loss and postoperative complications. However, embolisation requires a sound knowledge of the vasculature of the meninges since these vessels supply portions of the cranial nerves. Literature consulted have investigated anatomical features of meningiomas; however, there is a scarcity of studies investigating patients specifically referred for preoperative embolisation. Therefore, this study aimed to investigate the anatomical features, namely the demographic profile, location, volume and vascularity of intracranial meningiomas referred for preoperative embolisation. This entailed using Magnetic resonance imaging and Digital subtraction angiography obtained from the data bank at the central regional hospital in Durban, South Africa. A retrospective chart review yielded 103 patients (subset 1: 98 patients with a single meningioma; subset 2: 5 patients presenting with multiple meningiomas) presenting with a meningioma within the fourth decade of the patient's life and primarily within the female population (subset 1: 67.3%; subset 2: 80%). Meningiomas were mostly observed within the supratentorial region (subset 1: 57.2%; subset 2: 91.67%). Regarding tumour volume, the largest meningiomas were found within the supratentorial region (subset 1: 90.9 cm³; subset 2: 43.9 cm³). In terms of meningioma vascularity, within the supratentorial region, the external carotid arteries were noted to be a common primary feeder vessel for both subsets, for the skull base region the primary arterial supply is the internal carotid arteries in subset 1. This study provides insight into the anatomical basis of intracranial meningiomas within a select South African population as it has introduced a novel methodology of meningioma vascularity. This may assist endovascular surgeons in assessing the feeder vessel contributions of meningiomas and understanding the prevalence of these anatomical parameters in this population. Ethical approval has been granted (ethics reference number: BREC/00001934/2020).

P1Vascular quantification of the human glenoid labrum

Yousef A Almajed^1,2; Andrew C Hall³; Thomas H Gillingwater^1,3; Abduelmenem Alashkham¹

¹Anatomy, Biomedical Sciences, University of Edinburgh, Edinburgh, UK; ²Basic Sciences, Prince Sultan bin Abdulaziz College for Emergency Medical Services, King Saud University, Riyadh, Saudi Arabia; ³Centre for Discovery Brain Sciences, Biomedical Sciences, University of Edinburgh, Edinburgh, UK

Studying the labral vascularity would enhance our understanding of its healing potential in labral injuries. Vascularity of the glenoid labrum has not been investigated in detail. Most of these studies were descriptive and no quantitative analysis of the vascular density in different regions of the glenoid labrum has, to our knowledge, been reported. Therefore, this study aims to quantitatively analyse glenoid labrum vascularity. A total of 16 shoulders from 4 males and 4 females (mean age of 77 years) were dissected and the glenoid articular face segmented into 8 regions. Each region contained a cross-sectional view of the labrum, capsule, articular cartilage and bone. These regions were decalcified, embedded in wax then sectioned. Immunohistochemistry was conducted using Alpha-smooth muscle actin (αSMA) to identify blood vessels within the labrum. After slide scanning, the vascular count and labral vascular density, which were determined in relation to labral area (vessel/mm²), were carried out using Fiji software. Kruskal–Wallis tests were performed to assess the vascular differences between the different regions then followed by Dunn's post hoc test with Bonferroni adjustment for each pair of regions. There was a significant difference between different regions in blood vessel count (p < 0.001) with the posteroinferior region having lower blood vessel count than the superior, anterosuperior, and anteroinferior regions (p = 0.001, p = 0.012 and p = 0.016, respectively). Furthermore, the posterior region had a lower blood vessel count than the superior, anterosuperior, and anteroinferior regions (p = 0.001, p = 0.001 and p = 0.014, respectively). In terms of blood vessel density, there was a significant difference between different regions (p < 0.001) with the posteroinferior region being significantly lower than the superior, anterosuperior, and anterior regions (p = 0.002, p < 0.001 and p = 0.046, respectively). These results showed that the posteroinferior quadrant is the least vascularised region of the glenoid labrum. This could be due to the glenohumeral ligaments' and biceps tendon attachments to the labrum contributing to glenoid labrum other regions' vascularity.

The study was carried out in Anatomy, University of Edinburgh, which is regulated by Human Tissue Act (Scotland) 2006.

P2Pre- and post-fornix fibres in young adolescents with psychotic experiences

Assael Alsehli¹; C Browne¹; Erik O'Hanlon²; A Nasa³; Mary Cannon²; Darren W. Roddy⁴

¹Royal College of Surgeons, School of Medicine, Dublin, Ireland; ²Royal College of Surgeons, Department of Psychiatry, Dublin, Ireland; ³Trinity College Dublin, School of Medicine, Dublin, Ireland; ⁴Trinity College Dublin, Trinity College Institute of Neuroscience, Dublin, Ireland

The fornix is a C-shaped white matter structure that carries important cognitive function. It is located in the middle of the brain arching over the thalamus. It extends from the hippocampus to the hypothalamus, thalamus and prefrontal regions. The descending columns of the fornical fibres are separated by the anterior commissure into pre-commissural and post-commissural fibres. The pre-commissural fibers connect the hippocampus to medial septal nuclei of the thalamus, nucleus accumbens and prefrontal cortex, and the post-commissural fibres connect to the mammillary bodies and then to the anterior nuclei of the thalamus. Studies have found a connection between psychotic disorders like schizophrenia and changes in the fornix. As most psychotic experiences happen in early adolescents, thus could put them at risk of developing psychotic disorders later in life, our study focuses on studying the changes of pre- and post-commissural fibres of the fornix in adolescents with early psychotic disorders. We hypothesized that there are changes in fornical fibres in adolescents who experienced psychotic experience compared to those who do not. Diffusion MRI scans were collected from 25 young people who are diagnosed with early psychosis and 25 healthy controls. The fornical fibres were extracted using ExploreDTI from the diffusion scans using a bespoke previously validated protocol. Comparison of the data of the two groups found no significant difference, however, a trend FA change (p = 0.08) in the pre-commissural fornix in the PE group was found. FA is a measure of neuronal integrity and this trend may suggest connectivity changes in the PE group between the prefrontal cortex and hippocampus. This pilot study aims to explore the pathological changes of the fornical fibres and its relationship to early psychotic disorders. To strengthen the finding of this study and confirm the involvement of the fornix in early psychosis more participants need to be studied.

Ethics statement: Ethical approval for this study was obtained from the Beaumont Hospital REC as part of the ongoing Adolescent Brain Development Study.

P3The use of haptico-visual observation and drawing method in enhancing the learning of anatomy

Sarah Alturkustani¹; Leonard Shapiro²; Siobhain O'Mahony¹; Mutahira Lone¹

¹University College Cork, Cork, Ireland; ²University of Cape Town, Cape Town, South Africa

The haptico-visual observation and drawing (HVOD) method is a newly emerging approach in anatomy education that helps students understand the three-dimensional form of anatomical structures. This approach can facilitate spatial understanding of structures, allowing the construction of a three-dimensional mental representation. The HVOD method is a stepwise process that relies on the simultaneous act of observing a 3D object with vision and touch and drawing it by hand on a piece of paper. Our aim in this qualitative study was to gather student opinion on how the HVOD method aided their learning of anatomy, how it differed from conventional learning methods, and what values it added to the learning experience. Eleven students participated in the study by attending a 2-day HVOD method workshop. Qualitative data were collected through reflective questionnaires which addressed students' HVOD experience. All 11 students mentioned an appreciation of the details and form of the observed structure at least once, indicating deeper anatomical understanding. Further, students believed that they remembered more of the structure by the HVOD than they would have done by conventional methods, with some of them attributing this to the effect of learning by doing. One interesting effect was student's ability to visualize and rotate the mental images constructed by the haptico-visual observation. Given the nature of the approach, this effect could be the result of multi-angular viewing of the observed structure. The act of drawing required students to carefully observe the structure to provide an accurate depiction. This urge helped the students gain a higher appreciation of its features. Another effect commonly experienced by all students was the construction of a mental image, which in many instances was referred to as being three-dimensional. Applying the HVOD principles in the anatomy lab can be a valuable addition and can have positive effects on the learning process. Further investigations of quantitative nature are required to verify these findings. This study was conducted in accordance with the UCC Code of Research Conduct. All participants gave written informed consent to participate in the study. Ethical approval was obtained from the Social Research Ethics Committee.

P4Experience of learning human anatomy and histology during COVID-19 pandemic in Kharkiv National Medical University

Olga Avilova; Viktoria Erokhina; Nguyen Do To Uyen

Kharkiv National Medical University, Kharkiv, Ukraine

The purpose of the current study is to examine the nature of distance learning during the quarantine period at Kharkiv National Medical University (KNMU), as well as exploring the possible advantages and disadvantages compared to traditional education. An online survey consisting of 19 questions was conducted on Google Forms platform among 395 students at Kharkiv National Medical University. Individuals' learning progress during histological and anatomical classes using different methods such as virtual aggregators of slides and 3D programs, 3D Organon Anatomy Atlas, in particular, were also observed. Data analysis was performed on a Google Sheetss statistical platform. According to students' answers, 70% of them had their first experience with distance education when the current pandemic started. Participants agreed that the main advantages of distance education were the extra time they had to prepare for classes and revise study materials (72%), more comfortable space to study at home (69%), more convenient access to online materials (62%) and the ability to watch recorded lectures repeatedly (59%), the higher promotion of self-controlled study (51%), more time staying at home (48%), the higher ability to concentrate on studying (42%), easier to ask questions (37%) and the higher effectiveness of studying due to virtual explanation (32%). Additionally, 61% of responders stated that they considered themselves more active in online classes than in traditional face to face. On the other hand, students also claimed some major challenges they had faced while having distance education such as the lack of clinical approach to patients, technical problems with IT devices, Internet connection and the lack of interaction with teachers, which has an incidence of 69%, 45% and 42%, respectively. Other disadvantages of distance learning were marked as the lack of group discussion (37%), less motivation to prepare for classes (29%), difficult to concentrate (22%), lack of self-discipline (21%), difficult to ask questions (18%) and the disability to afford to buy laptops or tablets to attend online lectures (9%). Furthermore, there were 59% of responders saying that the lack of clinical practice was the main factor that made them frustrated, which led to the reduction in students' interest during online classes. Additionally, 53% of responders had tried online virtual platforms to practice clinical skills which were insufficient at normal online classes provided by teachers. It also showed that there were 61% of total students managed their time effectively to prepare for medical licensing examinations like KROK, IFOM and USMLE. View of anatomical structures was achieved via 3D programs, virtual labs, pictures of cadaveric material. During the pandemic, KhNMU obtained 3D Organon license keys to access virtual anatomical atlas data and it showed great increase in the material perception (78% of responders claimed that it helped to grasp anatomy discipline well in online mode). At the end of the survey, 30% of answers participants stated that distance education was extremely effective in term of increasing their theoretical knowledge while others rated the effectiveness at level 1 (extremely ineffective) (9%). On the other hand, in term of improving clinical skills, there was a large number of students claiming that distance education was extremely ineffective (34%) comparing to 12% of them rating these terms at level 5 (extremely effective). Despite the difficult conditions we all found ourselves during pandemic, there were quite positive results showing high knowledge acquisition during quarantine. Also, there was positive feedback from students regarding organization of online examinations, as there were no technical failures during the session and all the examiners supported the students in these difficult times. All students willingly took part in the survey and were aware of further publication of this material.

P5Using musculoskeletal modelling to investigate the functional significance of craniofacial form variation within the genus Homo

Thomas Baird¹; Andrew Cuff^1,2; Laura Fitton^1,3

¹Centre for Anatomical and Human Sciences, Hull York Medical School, University of York, York, UK; ²Human anatomy resource centre, University of Liverpool, Liverpool, UK; ³Department of Archaeology, University of York, York, UK

Gracilisation of craniofacial form during evolution of the genus Homo is often associated with dietary shift from high meat consumption to increased reliance upon processing technologies. Such changes may reduce masticatory demands, but whether craniofacial morphology differences between early Homo and modern humans have impacted masticatory performance has rarely been tested. This study presents the development of a multibody dynamic model of a modern Homo sapiens which allows for anatomical modification. The functional significance of variation in zygoma and joint morphology within Homo are subsequently investigated. To construct the masticatory model a living modern human male was digitized using two different imaging modalities (MRI, structured light scanning) with hard and soft tissue anatomy virtually reconstructed. Using SIMM, the cranium and mandible were represented as rigid bodies with mandibular rotation and translation possible at the temporomandibular joint. Masticatory muscles were modelled as strands with both passive and active components (Hill-type muscle model). Maximum bite force and gape were predicted. Using a CT scan of KNM-ER 3733 (Homo erectus) for reference, the modern human was then modified to create a hypothetical model with erectus-type masseter positioning and jaw joint translational capabilities. Due to their less mechanically challenging diet, it was predicted that the modern human model would record a lower bite force and a lower maximum gape capability compared to the erectus-type model. As predicted, the modern human model produced the lowest bite force but had the highest increase in maximum interincisal gape. These results suggest a relaxation in the maximum bite force requirements for H. sapiens compared to H. erectus, but their joint anatomy appears advantageous for increasing gape. While not directly tested here, we predict that this modern human joint form may be optimised to increase gape, compensating for an overall reduction in gape resulting from a more orthognathic face. Future work, utilising this model will enable the examination of such form-function hypotheses in relation to genus Homo. Full ethical approval for this work was granted by the Hull York Medical School Ethics Committee (reference 20 18).

P6A morphometric analysis of the cranial fossae in patients with scaphocephaly

Vensuya Bisetty; Lelika Lazarus; Rohen Harrichandparsad; Anil Madaree

University of KwaZulu-Natal, Durban, South Africa

Scaphocephaly is a cranial deformity that results from premature fusion of the sagittal suture and is characterized by an elongated and narrowed skull. Patients with this condition present varying clinical features including frontal bossing and occipital protrusion. Most morphological and morphometrical studies in patients with scaphocephaly focus on the cranial vault. Literature on the morphometry of the cranial base and its fossae in these patients is sparse. Therefore, this study aimed to analyze and compare the morphometry of the anterior, middle, and posterior cranial fossae (ACF, MCF and PCF) in patients with scaphocephaly. The length and width of the ACF, MCF and PCF were measured using fixed anatomical landmarks on two-dimensional computed tomography (CT) scans of 24 consecutive patients diagnosed with isolated sagittal synostosis at a regional hospital in South Africa between 2014 and 2020, and 14 non-affected/normal paediatric patients who were selected as controls. A comparison of the results between patients with scaphocephaly and the controls showed that the ACF and PCF lengths increased significantly (p = 0.041 and p = 0.018) in patients with scaphocephaly. No differences in the MCF lengths were observed (p = 0.278; 0.774). When compared by the degree of severity of the deformity, the ACF and PCF lengths were significantly increased (ANOVA, p = 0.033; post hoc, p = 0.013 and ANOVA, p = 0.015; post hoc, p = 0.036) in scaphocephalic patients within the severe group as opposed to the control group. The morphometric data obtained indicate a preponderance of deformity in the ACF and PCF with elongation along the anteroposterior plane (lengths) in scaphocephalic patients. Minimal changes were observed in the transverse plane (widths) in scaphocephaly versus controls. This study contributes to the literature by providing novel morphometric data based on a select South African population. The data obtained could aid craniofacial surgeons in understanding which cranial fossa is most affected in scaphocephaly and to what extent, to decide on the most appropriate method of treatment. Ethical approval for this study was obtained from the Biomedical Research Ethics Committee of the University of KwaZulu-Natal (BREC/00002084/2020). This study utilized retrospective CT scans and therefore posed no risks to the patients. The data obtained were anonymized.

P7Exploring the thalamus in young adolescents with psychotic experiences

Ciaran Browne¹; Assael Alsehli¹; Erik O'Hanlon²; Anurag Nasa³; Mary Cannon²; Darren William Roddy⁴

¹Royal College of Surgeons, School of Medicine, Dublin, Ireland; ²Royal College of Surgeons, Department of Psychiatry, Dublin, Ireland; ³Trinity College Dublin, School of Medicine, Dublin, Ireland; ⁴Trinity College Dublin, Trinity College Institute of Neuroscience, Dublin, Ireland

The thalamus is an egg-shaped structure that lies paramedian in the brain, adjacent to the third ventricle. The thalamus is mostly a grey matter structure of the diencephalon, located above the midbrain, allowing nerve fibres to project outwards into the cerebral cortex in all directions, allowing an exchange of motor and sensory information between the brain and the body. Psychotic experiences (PEs) can commonly occur in children and adolescents, with more occurrences in younger children (9–12) than older adolescents (13–18). While the majority of children who have a psychotic experience do not go on to develop psychotic disorder (e.g. schizophrenia), they are at an increased risk of being diagnosed with a psychotic disorder in later life. We hypothesised that differences in thalamic volumes are present in young people who have experienced PEs compared to those who have not. Using MRIs from adolescents who had experienced a PE and controls, and the FreeSurfer 6 programme, data from the thalamus was extracted. Data from adolescents who had experienced a strong PE and adolescents who had experienced a weak PE were matched with adolescents who had not experienced a PE for age, sex, handedness and intercranial volume. No overall thalamic differences were found, however, differences between certain nuclei of the thalamus were demonstrated. These differences were shown in the left lateral geniculate nucleus (p = 0.03 and effect size = 0.078), the left anteroventral nucleus (p = 0.033 and effect size = 0.076) and the right paratenial nucleus (p = 0.025 and effect size = 0.082). Psychosis is not fully understood and psychotic experiences, particularly in adolescents, is under-researched despite knowing that children and adolescents who have had a PE are at an increased risk of developing a psychotic disorder. While we have demonstrated differences in thalamic volume in those who have had a PE, more research needs to be done on how and why this occurs. Ethical approval for this project has been granted by the RCSI Human Research Ethics Committee for the IHEAR-psychotic experiences in Irish adolescents study.

P8To replace or not replace that is the question: Addressing fate decisions during minipig tooth replacement

Isabel Chan¹; Juan M Fons¹; Marcela Buchtova^2,3; Abigail S Tucker¹

¹Centre for Craniofacial and Regenerative Biology, Faculty of Dentistry, Oral and Craniofacial Sciences, Guy's Hospital, King's College London, London, UK; ²Department of Experimental Biology, Faculty of Science, Masaryk University, Brno, Czech Republic; ³Laboratory of Molecular Morphogenesis, Institute of Animal Physiology and Genetics, Czech Academy of Sciences, Brno, Czech Republic

Understanding fate decisions is an essential goal in developmental biology with important ramifications for tissue regeneration and repair and our understanding of disease. Every cell in a body receives and provides cues to its neighbours allowing initially similar cells to embark on unique pathways. Here, we have investigated the decisions that determine whether a replacement tooth forms or not by a comparison of the development of the dental lamina in the minipig. The minipig like humans has two sets of teeth, a deciduous and permanent set. The deep dental lamina, which forms a tooth, was compared to the interdental lamina which does not form a tooth. The dental lamina from different parts of the jaw were dissected from embryonic minipig embryos and processed for bulk RNAseq. Bioinformatic techniques, such as DESeq2, were then used to compare gene expression patterns in the two laminas. The results of the analysis showed a total of ten differentially expressed genes including two undefined genes. Expression patterns of the candidate genes were validated using publicly available datasets on Eurexpress, Allen Brain and Genepaint with respect to mouse molar development. One of the candidates, MTHFD2L, was expressed in the tip of the epithelium of the molar placode. Molars are formed by serial addition whereby a single placode forms all three molars by budding of the dental lamina at the posterior of the jaw. This system of additional molar formation shares many characteristics with tooth replacement, highlighting this gene as a good candidate to focus on for future experiments. Ethics to work on minipig embryos was approved by the IAPG, Czech Academy of Sciences.

P9Anatomical variation between populations of British red squirrels: The potential impact of supplementary feeding

Kim E Chandler¹; Philip G Cox^1,2

¹Centre for Anatomical and Human Sciences, Hull York Medical School, University of York, York, UK; ²Department of Archaeology, University of York, York, UK

Red squirrels Sciurus vulgaris have suffered significant reduction in numbers and distribution in Britain since the introduction of the invasive grey squirrel Sciurus carolinensis in the late 18th century. Populations that remain are fragmented and little genetic exchange occurs between them, each population on a separate evolutionary trajectory. We show, through geometric morphometric analysis, that there is significant morphological variation in the crania and mandibles of British red squirrel populations, both in shape and size. Particularly distinct anatomical variation is evident in a managed population of red squirrels from Formby Nature Reserve, Lancashire. As different populations have access to different food sources, and the observed variation is particularly notable in the masticatory apparatus, we suggest that this anatomical variation is a response to the local available diet. It is currently unknown if this response is plastic or evolutionary, but the results presented here demonstrate the potential for anatomical form to change measurably over relatively short time periods.

Ethics statement: No human-cadaveric material has been used in my research, all specimens are animals that died of natural causes or accidental deaths and were collected by an outside organisation (National Museum of Scotland) and not culled for this research.

P10Anatomy of termination of popliteal artery: A multidetector CT angiographic study

Jyoti Chopra; Gourav; Amber Irfan; Anit Parihar; Anurag Rai

King George's Medical University, Lucknow, India

The detailed knowledge of anatomy of termination of popliteal artery (PA) and its distal variations has gained importance for endovascular interventionist, plastic, vascular and orthopaedic surgeons because of upsurge in the procedures like embolectomy, vascular grafting, free fibular flap surgery, high-tibial osteotomy, etc. Kim's classification is most commonly used to categorize the variations in the pattern of termination of PA based on the level of termination and presence of hypoplasia/aplasia of anyone of its terminal branches. There are only few cadaveric and angiography studies from India, reporting variant anatomy of termination of PA and none using 128 slice tomography. The present study aimed to observe the terminal branching pattern of PA and morphology of terminal branches using 128 slice CT angiography and observe its relation with gender and laterality. The CT angiography images of 181 lower extremities (137 males and 44 females) of 100 patients (age 5–75 years) were reviewed retrospectively. 75.69% had usual type Ia pattern and 24.31% had variant pattern. Type III was the most commonly (19.34%) observed variation, in which type IIIa had maximum prevalence (11.05%). Type IIb and IIc were not observed in the present study. Out of 84 bilaterally observed cases, 19.05% of patients had unilateral variation and 15.48% had bilateral variation. 8.33% of patients had bilaterally similar variation and 7.14% had dissimilar. No significant difference in branching patterns was found between gender and sides. The mean length of TPT in type Ia pattern was 3.00 ± 0.99 cm; on right side 3.21 ± 1.02 cm; left 2.82 ± 0.93 cm; in males 2.9 ± 1.00 cm and females 3.37 ± 0.85 cm. The difference in mean length of TPT between the sides and gender was statistically significant. In type IIa pattern, the mean length of TPT was 7.16 ± 3.75 cm. In one case having IIIb pattern exceptionally long TPT (12.97 cm) was observed. The prevalence of variation in termination pattern of PA is very high therefore its knowledge is important for performing any intervention in this region to avoid postoperative vascular complications hence reducing patient suffering. Approval for ethical waiver was obtained from the Institutional Ethical Committee of King George's Medical University.

P11Revealing the biomechanics of the masticatory muscles in the eastern grey squirrel (Sciurus carolinensis) using multibody dynamics analysis

Philip G Cox¹; Peter J Watson²

¹University of York, York, UK; ²University of Hull, Hull, UK

In mammals, the function of the muscles of mastication as a whole is to move the mandible relative to the cranium to bring the teeth into and out of occlusion. However, the precise function of the individual muscles is often less clear. The jaw adductor muscles are notably specialised and multi-layered in rodents, leading to a complex suite of masticatory movements. Here, we used the computational technique of multi-body dynamics analysis (MDA) to model feeding in the grey squirrel (Sciurus carolinensis) and determine the relative contribution of each jaw-closing muscle in the generation of bite forces. Incisor and molar biting were simulated at different gapes in the MDA model. Subsequently, a series of “virtual ablation experiments” were performed at each gape, whereby the activation of each bilateral pair of muscles was set to zero. Maximum bite force was found to increase with increasing gape for both incisor and molar biting, which may reflect the squirrel's diet of relatively large, mechanically resistant items, such as nuts. In line with previously published research, the superficial and anterior deep masseter were the largest contributors to bite force at both bite points. However, the temporalis had only a small contribution; further analysis indicated that the temporalis may play a more important role in jaw stabilization than in the generation of bite force. This study demonstrated the ability of MDA to reveal the details of rodent masticatory muscle biomechanics without the need for in vivo experimentation. No ethical approval was needed for this project as it was conducted entirely in silico using morphological image data freely available from www.morphosouce.org.

P12Investigating the role of the mesentery in the autonomic innervation of the developing rat gastrointestinal tract

Fiona Cronin¹; Kevin Byrnes²; Calvin Coffey^1,2; Kieran McDermott¹

¹University of Limerick School of Medicine, Limerick, Ireland; ²Department of Surgery, University Hospital Limerick, Limerick, Ireland

Our understanding of mesenteric structure and development has changed in recent years, and it is now accepted that the mesentery is a continuous, rather than fragmented structure. However, this clarification has prompted a need to re-examine its anatomical relationships with the developing gastrointestinal tract (GIT) and investigate its potential role as a facilitator of neural crest cell migration during enteric nervous system development.

The aim of this research is to describe the development of the mesentery, gut, and enteric nervous system independently and subsequently determine how these components relate to each other during development. Of particular interest is clarifying the manner in which autonomic nerve fibres traverse the mesentery and ultimately innervate the gut and enteric nervous system. Histological and immunohistochemical analysis of semi-serially sectioned rat embryos at embryonic days 12, 14 and 16 are being undertaken to illuminate the process by which autonomic fibres are distributed to the gastrointestinal tract. Immunohistochemical analysis of neural crest, axonal and neurotrophic markers is providing insight into the developmental mechanism by which the axons path-find and populate the gut wall. There are no nerve fibres evident in the developing mesenteric tissue at E12, but by E16 the clear presence of such structures suggests that E14 may be an important stage for GIT nerve development. A comparison of the presence and localisation of autonomic nerve elements between developmental ages should provide further insight into the role of the mesentery in early innervation of the gut.

Despite recent advances in our understanding of mesenteric anatomy, its role during development has yet to be clarified. Advances in our understanding of the innervation of the developing mesentery and gut have implications for advancing our knowledge of normal anatomy as well as relevant pathological states and diagnostic and therapeutic approaches.

Animal procedures were in accordance with the Republic of Ireland Department of Health and Children license.

P13Myoepithelial and immune cell dynamics in the ovine mammary gland during postnatal development

Benjamin Davies¹; Abigail Fowden²; Dino Giussani²; Clare Bryant¹; John Wills¹; Katherine Hughes¹

¹Department of Veterinary Medicine, University of Cambridge, Cambridge, UK; ²Department of Physiology, Development and Neuroscience, University of Cambridge, Cambridge, UK

The epithelial bilayer of the mammary gland consists of luminal epithelial cells and basal myoepithelial cells. The latter express alpha-smooth muscle actin (alpha-SMA). Little is known about how myoepithelial cells contribute to the postnatal development of the mammary gland although dynamic interactions between leukocytes and myoepithelial cells suggest that myoepithelial cells are important in both normal development and pathological processes. This project capitalises on similarities in the histo-anatomy of the human breast and ovine mammary gland to interrogate the role of myoepithelial cells in mammary development. The male mouse mammary gland regresses prior to birth, and consequently use of other species to study male mammary gland biology requires additional investigation. Therefore, the mammary gland of male sheep was also examined. Mammary myoepithelial proliferation was examined at various postnatal developmental stages. Instances of myoepithelial proliferation were quantified following immunohistochemical staining for Ki67 and alpha-SMA. “Clear, unobstructed brain imaging cocktails” (CUBIC) was utilised to examine 3D morphological changes to myoepithelial cells and macrophages during postnatal development. Immunohistochemistry for IBA1 and CD3 was used to localise immune cells in the male mammary gland. Myoepithelial proliferation is significantly higher in female neonatal sheep than any other developmental stage. There is also a significant reduction in myoepithelial proliferation between pregnancy and lactation. CUBIC 3D imaging allows visualisation of the ruminant mammary gland to a depth of 100 μm and demonstrates close association between macrophages and myoepithelial cells. In the male mammary gland, macrophages and T-lymphocytes are closely intercalated with myoepithelial cells. Future work will utilise artificial intelligence-enabled image analysis to quantify changes in myoepithelial morphology during development. An in vitro cell culture model will be developed in order to co-culture myoepithelial cells and macrophages from ovine milk, facilitating the study of the interactions between these cells.

Ethics statement: The Department of Veterinary Medicine, University of Cambridge, Ethics and Welfare Committee approved the study plan relating to the use of ovine post-mortem material (reference: CR223). The non-regulated scientific use of post-mortem mammary tissue collected from research animals was approved by the Named Veterinary Surgeon.

P14An investigation on the adipose tissue distribution between male and female faces: Beyond facial reconstructions

Thakshila Silva; Eilidh Ferguson

University of Glasgow, School of Life Sciences, Glasgow, UK

Facial soft tissue depths (FSTD) refer to the tissue thickness that is attached to the facial skeleton and is composed of structures, such as skin, adipose tissue, muscle and fascia. The distribution of adipose tissue deposits differs between male and female bodies, particularly during weight fluctuation. There are a vast range of biological mechanisms at play which cause this difference, such as gene expression and presence of sex steroids. However, no previous studies have investigated whether the adipose tissue variation with weight gain in the face is proportional between males and females. This research is vital as it may contribute to better efficacy of not only facial reconstructions but also digital facial identification systems, cosmetic and clinical surgeries. Therefore, this study aims to determine if there is a difference in the variation of FSTD at nine anatomical landmarks as body mass index (BMI) increases between males and females. As sex-based differences have been observed across populations, this FSTD difference will be further examined between Asian and Caucasoid ancestry groups. An electronic search was conducted across five databases to identify full-text articles with average FSTD measurements for both males and females in at least two different BMI categories. The final number of articles selected was nine, and nine landmarks common to all papers were identified and selected for analysis. General linear models were performed at each landmark between BMI and sex. Statistical analysis was also performed to compare Asian and Caucasoid ancestry groups. No significant differences were observed between males and females in the FSTD increase with increased BMI at any facial landmark (p > 0.05). Similarly, FSTD increase with increasing BMI between males and females was similar across Asian and Caucasoid ancestry groups (p > 0.05). Although results suggest no difference in adipose tissue deposition between males and females with increased BMI, we were unable to compare some areas of the face most affected by weight gain, due to limitations in available data. Further research is therefore necessary using standardised methods of measurement across different age and population groups to better understand the underlying mechanisms of adipose tissue deposition in male and female faces. This research project used anonymised data from previously published studies, and therefore further ethical approval was not required.

P15The amygdala in psychotic experiences in adolescence

A. Gazzaz¹; Olivia Mosley¹; Allison Kelliher¹; Anurag Nasa²; Caoimhe Gaughan²; Elena Roman¹; Erick O'Hanlon³; Mary Cannon³; Darren W. Roddy⁴

¹Royal College of Surgeons, School of Medicine, Dublin, Ireland; ²Trinity College Dublin, School of Medicine, Dublin, Ireland; ³Royal College of Surgeons, Department of Psychiatry, Dublin, Ireland; ⁴Trinity College Dublin, Trinity College Institute of Neuroscience, Dublin, Ireland

The amygdala is a structure in the brain formed by eight component nuclei. It is involved in many disorders, including depression, sleep deficit and anger, as well as psychosis, being a broad term encompassing problems in reality testing. In this study, we investigated the amygdala and its component nuclei volumes in a group of young adolescents with psychotic experiences (PE) over a 5-year period. The sample included 43 adolescent healthy controls, 30 with PE, and 18 with ‘weak’ PE (only some features of PE). All were healthy school-going children who had never attended a doctor for mental illness. Data were first collected at approximately age 14, with repeat data after 2 and 5 years. Volumetric data were collected using high-resolution T1 and T2 MRI. Nuclei volumes were extracted using Freesurfer 6.0. 8 amygdalar nuclei were calculated. Univariate analyses of covariance were performed between the volumes from each of the subfields of the amygdala in controls, PE, and ‘weak’ PE groups. The influence of potential confounding variables (age, sex, and estimated total intracranial volume) was corrected in this model. Longitudinal analysis of volumes was assessed using a linear mixed effects model. No differences were found between the substructural volumes in any of the groups at any age. Similarly, there were no differences over time for any of the three groups. Amygdalar volumes showed no change at any timepoint or between timepoints for our three groups. This suggests that the volume of the amygdala has no role in the symptomology of these young adolescents with psychotic experiences. Other explanations may include the relatively small sample size involved and the subtle phenotype in both the PE and weak PE groups. A larger powered study may reveal amygdala volume differences.

Ethics approval was obtained from the Beaumont Hospital REC for the Adolescent Brain Development Study.

P16Microstructural changes along the cingulum in young adolescents with psychotic experiences: An along-tract analysis

A. Gazzaz¹; Elena Roman¹; Anurag Nasa²; V. Sooknarine¹; Caoimhe Gaughan²; Erik O'Hanlon¹; Darren Roddy²; Mary Cannon¹

¹Royal College of Surgeons in Ireland, Department of Psychiatry, Dublin, Ireland; ²Trinity College Dublin, Trinity College Institute of Neuroscience, Dublin, Ireland

The cingulum is a discrete white matter tract beneath the cingulate cortex and it connects the overlying frontal, parietal, cingulate, and temporal regions with roles in memory, attention and emotional processing. Psychotic experiences (PEs), such as hallucinations or delusions, have been shown to be particularly common among young people. Children or adolescents that are younger (9–12 years) have a higher prevalence of PEs compared to older (13–18 years) adolescents. Although most young people who describe PEs in early life do not develop a later psychiatric illness, these individuals are at increased risk for a later diagnosis of a psychotic disorder such as schizophrenia. Further neurobiological research on these vulnerable young people may aid our understanding of how psychosis develops. We hypothesised that cingulum differences exist in young people with PEs not at the level of the four cingulum sections, but rather at the more granular voxel-sized measurements. Whole brain High Angular Resolution Diffusion Imaging (HARDI) of 25 young people aged 11–13 years with PEs and 25 young people that were matched for age, sex, and handedness, without psychotic experiences were performed. No differences were found at the level of cingulum sections; however, region-specific clusters of microstructural change were found in the left retrosplenial and right subgenual areas using along-tract analysis. Following Bonferroni significance adjustment (p < 0.0063), the left subgenual (p = 0.014), left body (p = 0.033) and left (p = 0.032) and right (p = 0.011) parahippocampal section volumes were smaller in the PE group at a trend level when uncorrected for multiple comparisons. This is the first study to use both section and along tract analysis in young adolescents with PEs, and the first study to show that along tract analysis may be useful in uncovering deeper, previously hidden, differences in the cingulum.

Ethics approval was obtained from the Beaumont Hospital REC for the Adolescent Brain Development Study.

P17The ontogeny of biting resistance and facial remodelling in modern humans and Neanderthals

Lisa Genochio^1,2; Lou Albessard-Ball¹; Federica Landi³; Vladimir Doronichev⁴; Liubov V Golovanova⁴; Bruno Maureille⁵; Antonio Profico⁶; Paul O'Higgins^1,2

¹Department of Archaeology, University of York, York, UK; ²Hull York Medical School, University of York, York, UK; ³Institute of medical and biomedical education, St George's University, London, UK; ⁴Laboratory of Prehistory, St. Petersburg, Russia; ⁵PACEA, University of Bordeaux, Bordeaux, France; ⁶The Catalan Institute of Human Paleoecology and Social Evolution (IPHES), Tarragona, Spain

Morphological studies of the Neanderthal craniofacial system have shown that its post-natal growth and development diverge from that of modern humans. During post-natal ontogeny, crania change in size and shape through displacements of bones at sutures and synchondroses and by remodeling of bony surfaces. Furthermore, the developing cranium is loaded by forces from the masticatory system in feeding which change as diet changes.

Differences in patterns of bone growth remodelling exist between these two species, with modern humans presenting bone resorption on the subnasal maxillary surface, while Neanderthals present extensive bone deposition. Such differences in bone remodeling have been hypothesized to be related to heritable differences in developmental programmes or to differences in how the facial skeleton is strained during masticatory system loading. Here we test this second, mechanical hypothesis.

The present study examines the ontogeny of modern human and Neanderthal biting resistance in relation to remodelling. We used a virtual ontogenetic series of 12 Neanderthal and 63 modern human skulls ranging from birth to adulthood. Growth and development were modelled using geometric morphometric approaches and followed by finite element analyses to simulate loading and estimate facial strains in each species. We then assessed the association between masticatory loadings, facial strains and facial remodelling in developing modern humans and Neanderthals.

Our results show that during biting simulations, in both species, the highest strains are located on the anterior maxilla, orbital, and anterior subnasal surfaces and decrease between infancy and adulthood. However, strains show differences in distribution and magnitude among age stages and species. Further, FEA shows that biting performance and load resistance varies with age and differs between species.

These findings confirm that differences exist between Neanderthals and modern humans in loading history throughout post-natal growth and development and these partially reflect differences in remodelling maps. Therefore, we cannot exclude the possibility that differences in the ontogeny of masticatory system performance and load resistance underlie the differences in the distribution of craniofacial growth remodeling features. Further work is needed to more directly compare cumulative strains arising from diverse masticatory system loads in both taxa with facial growth remodeling maps.

Ethics statement: The modern human specimens were obtained by segmenting CT-scans from several sources: the online database Nespos (www.nespos.org), the University of Leeds (UK) and University College London (UK); the Scheuer collection, courtesy of the University of Dundee (UK) and Dr Craig Cunningham; the Bosma collection of the University of Maryland (Baltimore, USA). These collections are maintained under appropriate legislation in their respective countries and their use was approved by the Hull York Medical School Ethics Committee (York, UK).

P18Finite element analysis of infant brain expansion and muscle activation shows the importance of cranial sutures for healthy skull growth

Louisa Hulls¹; Mehran Moazen²; Alana C Sharp³

¹Human Anatomy Resource Centre, University of Liverpool, Liverpool, UK; ²Department of Mechanical Engineering, University College London, London, UK; ³Institute of Life Course and Medical Sciences, University of Liverpool, Liverpool, UK

Craniofacial sutures are unique joints consisting of soft connective tissues between the skull bones. They are important sites for bone growth during development, and for absorption of mechanical stress, but their mechanical function is not well understood. Craniosynostosis is a congenital condition causing premature fusion of one or more cranial sutures, and unless there is early surgical intervention this can lead to serious clinical pathologies, such as head malformations and brain damage. Corrective surgery, including cranial vault remodelling, fronto-orbital advancement or spring-mediated cranioplasty, aims to separate the fused cranial bones, restore head shape, and allow for normal cranial development. It is therefore important to understand the role sutures play in skull function to inform the surgical management of craniosynostosis patients to achieve the best outcome. Biomechanical modelling of skull growth and muscle forces may reveal important relationships between the stresses experienced by the cranial vault bones and patent or fused cranial sutures. Here, we use finite element (FE) analysis of an infant skull model to simulate brain growth and muscle loading with fused and patent sutures. Strain contour plots show FE models with patent sutures had significantly higher tensile strain at the frontal suture compared to the fused model, particularly during muscle loading. The compliant connective tissue in patent sutures allows more movement and deformation, which increases strain in the sutures and reduces strain in surrounding bone compared to the fused model. Our FE simulations show that patent sutures are important sites for cranial strain and dissipation of functional loads during skull growth and infant jaw muscle activation. Craniosynostosis increases rigidity of the skull with premature fusion of sutures resulting in abnormal skull shape as a consequence of adjusting growth direction. These findings suggest FE analysis has the potential to improve our understanding of the biomechanical environment of the infant skull during growth and could be used as a clinical tool for planning appropriate treatment strategy and optimising recovery for patients with craniosynostosis.

The specimen used to create the FE model was obtained from the archaeological collection at the University of Dundee, therefore no ethics approval was required.

P19A novel Haptic Surface Painting (HSP) activity enhances holistic anatomical understanding and 3D spatial awareness

Ella Hobbs¹; Leonard Shapiro²; Iain D Keenan¹

¹Newcastle University, Newcastle upon Tyne, UK; ²University of Cape Town, Cape Town, South Africa

Undergraduate anatomy education is evolving from didactic teaching and practicals, to incorporate a more diverse range of interactive resources. This is driven by the need for more widely accessible tools for remote learning, the significant time pressures on undergraduate medical timetables, and the need to encourage students to develop their own independent learning methods. Haptic Surface Painting (HSP) is a novel art-based approach that aims to provide an accessible way of developing deeper understanding of clinically relevant 3D spatial anatomy, by engaging students in body palpation and painting. Our work on Haptico-visual observation and drawing (HVOD) suggests that haptic techniques can offer considerable benefits for effective learning and memorisation, while several previous studies have identified the value of body painting for anatomy learning.

We aimed to evaluate the benefit of HSP within the modern context of undergraduate anatomy education by delivering an optional HSP workshop for medical students. A subsequent focus group (n = 7) explored their experiences and perceptions. Inductive semantic thematic analysis of focus group transcripts was then performed. Our findings indicate that HSP is a valuable supplement to undergraduate anatomy education. Participants highlighted the engaging practical nature of the approach and perceived improvements in memorisation. Palpation was identified as a factor in supporting a deeper and more holistic understanding of anatomy when compared to the curricular anatomy teaching that they had previously experienced. Furthermore, participants identified educator instructions and peer-group support as essential factors in enhanced anatomical understanding and 3D spatial awareness. However, some technical limitations of painting materials were reported, and participants requested additional guidance and structure for future workshops. We propose that HSP can provide an accessible and engaging approach for the consolidation of anatomical understanding. While certain modifications may be necessary to effectively deliver HSP within formal anatomy curricula, we aim to circumnavigate such requirements through integration and remote delivery within a supplementary massive open online course. Our findings will have implications for educators seeking to enhance student spatial understanding and those aiming to provide alternatives to traditional anatomical body painting. This work was approved by the Newcastle University Faculty of Medical Sciences Ethics Committee.

P20Exploring the most effective combination of drawing approaches for observation and understanding three-dimensional human anatomy

Leonard Shapiro¹; Iain D Keenan²; Joydeep D Chaudhuri³

¹University of Cape Town, Cape Town, South Africa; ²Newcastle University, Newcastle upon Tyne, UK; ³California Health Sciences University, Clovis, California, USA

Critical observation is crucial for an appreciation of the three-dimensional form and spatial complexity of anatomical structures and of their relationships. The incorporation of multiple distinct art-based approaches, including drawing, can be found in the academic literature with increasing frequency. Such techniques can provide a tool for students to observe, present, and analyse visual representations of their cognitive processes. The process of observing and drawing anatomical features is likely to support student learning due to increased time-on-task, attention and focus on the structures under observation. However, recent studies have shown varying success when aiming to support students in their observation and learning of anatomy. The authors propose that the elementary essence of drawing has not been categorically described, investigated, or discussed. Drawing is an umbrella term which incorporates several specific drawing approaches, which include photorealistic drawing, shading, contour drawing, cross-contour drawing, and gesture drawing. We propose that the application of a specific combination of drawing approaches in the context of anatomy education can result in alternative pedagogic outcomes. Here, we define the fundamental nature of drawing and describe the specific qualities and attributes of several different drawing approaches. In doing so, we provide the basis for exploring the benefits and limitations of each approach in maximising the critical observation and understanding of three-dimensional form. Furthermore, we explore why some drawing approaches are inherently more effective than others in supporting global observation and representation of the three-dimensional (3D) form of an anatomical structure. Specifically, we examine why the combination of cross-contour and gesture drawing approaches employed in the established Haptico-visual observation and drawing (HVOD) method, are likely to be most effective for global observation, definition, and memorisation of the 3D form of anatomical structures. Our definitions, descriptions, and analysis of drawing approaches for anatomical learning will have wide-ranging implications for educators seeking to introduce drawing as an art-based technique into their teaching and will in turn support their students in the critical observation of three-dimensional anatomy. Ethical approval was not required for this work.

P21Exploring the use of 3D scanning technology to demonstrate anatomical variation in human osteological specimens

Ellen Kelly; Jennifer Z Paxton

Anatomy@Edinburgh, Deanery of Biomedical Sciences, University of Edinburgh, Edinburgh, Scotland

The importance of technology, such as three-dimensional (3D) virtual models, in anatomical education, has never been greater, a fact which has only been reinforced by the remote learning necessitated by the COVID-19 pandemic. However, many such resources include only a single, idealised, computer-generated depiction of each anatomical specimen. Thus, students are not exposed to the imperfect and varied realities of human anatomy, potentially negatively affecting their anatomical knowledge and competency. This project aimed to investigate whether 3D scanning technology, specifically structured light scanning (SLS), could be used to produce a realistic digital anatomy tool, which demonstrates normal anatomical variation. Three biological repeats of six human bones/skeletal regions were scanned, resulting in a total of 23 virtual 3D models, which were published privately to a digital anatomy library on SketchFab. To quantitatively assess the representation of anatomical variation, individual models of each region were compared to each other, and Hausdorff Distances (HD)—the farthest distance from each point on one model to the closest point on another, superimposed model—calculated. The minimum and maximum mean HD were 0.965 and 6.103 mm, whilst the overall absolute minimum and maximum were 0.000 and 27.397 mm, respectively, indicating variation between the models. Qualitative analysis, in the form of ‘heat maps’ enabled visualisation of these differences, further confirming the presence of variation. These results indicate that SLS is capable of capturing and replicating anatomical variation within high-quality virtual models, providing promising evidence that SLS may be used to create anatomy learning resources which enable students to appreciate and interact with realistic human anatomy, even when outside the laboratory. Additionally, the knowledge gained through this project on best practices for SLS and model creation may help to inform future approaches in the use of SLS on human anatomical specimens, and in educational resources. All osteological specimens were obtained from Anatomy Teaching Lab at the University of Edinburgh and in accordance with the Human Tissue Act (Scotland) 2006.

P22A review of literature on the anatomical variations of the extrahepatic biliary tree using cadaveric techniques and imaging modalities

Grace Kettyle; Eiman Abdel Meguid

Queen's University Belfast, Northern Ireland, UK

Knowledge of the notoriously variable anatomy of the extrahepatic biliary tree is of greater importance than ever, given the increased occurrence and complexity of hepatobiliary surgeries including open and laparoscopic cholecystectomies. Failure by the surgeon to recognise the variant anatomy may lead to inadvertent iatrogenic injury of the biliary system. The aim of this project was to examine world literature to establish the various types and frequencies of anatomical variants within the extrahepatic biliary tree, using cadaveric techniques and imaging modalities, thereby contributing to the body of information available to anatomists, surgeons and radiologists. A database search of MEDLINE, EMBASE and PubMed was conducted in June 2021 and returned 3440 articles, of which 29 were deemed eligible for inclusion. A rare malposition, the left-sided gallbladder, was observed in 0.04%–0.60% across five studies. The medially inserted cystic duct into the common hepatic duct had a reported prevalence ranging from 10% to 24.3%. A normal cystic artery origin, that is, from the right hepatic artery was observed in 73.3%–92% with variations being seen from the left hepatic artery (1%–1.9%), gastroduodenal artery (1%–7.5%) and the aberrant right hepatic artery (3%–12.1%). It was also noted that in 3.6%–32% of subjects the course of the cystic artery lay extraneous to Calot's triangle. Michels' and Hiatt's classification systems were used to define the anatomical variations of the hepatic arteries: studies using Michels' type III reported a prevalence from 6.4% to 15%, Michels' type VI from 0.6% to 7% and Hiatt's type III recorded an incidence ranging from 9.7% to 14.8%. The most obvious finding to emerge from this project was the widely variable anatomy of the extrahepatic biliary tract and the contrasting reported data from the different imaging modalities used. Surgeons should therefore anticipate such complexities and adapt techniques to avoid biliary and arterial injuries and associated intra- and postoperative complications.

P23Is there such a thing as the retrocolumellar vein?

Cezar Octavian Morosanu^1,2; Stephanie Egerton¹; Claire M Tierney¹

¹Human Anatomy Resource Centre, Faculty of Life and Health Sciences, University of Liverpool, Liverpool, UK; ²Department of Neurosurgery, Royal Preston Hospital, Preston, UK

The anatomy behind epistaxis has been the subject of a multitude of contradictory publications in literature. In anterior epistaxis, Kiesselbach's plexus is commonly accepted as the source of bleeding both in adults and children. In the paediatric population, the retrocolumellar vein (RCV) also appears to be referenced as a source of anterior epistaxis. However, there appears to be absolutely no anatomical evidence to support its existence or its relevance in nasal bleeds. Herein, we aim to expand on this topic and provide a short introspection into the literature surrounding the RCV.

A systematic review was conducted on major search engines using the keywords ‘retrocolumellar’, ‘retro-columellar’ and ‘vein’. A total of 36 results were found, out of which only 16 were relevant to the topic of our review. No anatomical dissection study could be identified. Information on the RCV was limited only to 6 papers, the remaining 11 only mentioning the vessel as the site of anterior epistaxis. The RCV has been described posterior and parallel to the columella, measuring 2 mm in some papers and 20 mm in others. This vein appears to be frail and exposed superficially on the septum as its rupture can cause anterior epistaxis.

In addition, there is no mention of the RCV in any of the landmark anatomy textbooks. The vascular supply of the columella consists of multiple veins that drain this nasal structure, thus the name of RCV could be attributed to any of them extending in the posterior part of the nasal cavity.

In conclusion, it is unclear where the notion of RCV has arisen. Clinical examination through rhinoscopy might have been responsible for identifying a vessel with the morphology of a vein on the septum in the inferior proximity to Kiesselbach's plexus, but given the proportions of paediatric nasal cavities, the particular vein would have been difficult to discern from other vessels. Despite the possible clinical correlation, there appears to be no reason to single out one minuscule vein as responsible for anterior epistaxis. Anatomical dissection studies are necessary to clarify the existence of RCV and its role in nasal bleeds.

P24Anatomical variation of the branching pattern of the aortic arch: A literature review

Anna Murray; Eiman Abdel Meguid

Queen's University Belfast, Belfast, Northern Ireland, UK

Many anatomical variations of the branching pattern of the aortic arch have been documented within the literature. These variations find their origin in alterations of the embryological development of the arch and thus can be used as antenatal biomarkers for various syndromes. There exist five main branching patterns of the arch of the aorta: the normal configuration; the Bovine Arch (types 1 and 2); the Left Vertebral Artery arising from the arch; Aberrant Right Subclavian Artery; and the Thyroid ima artery. The aim of this study was to analyse the literature to identify the different reported anatomical variations in the branching patterns of the arch and to determine their prevalence. Literature searches of databases EMBASE and MEDLINE were performed in June 2021 and identified 1197 articles, of which 24 articles were considered eligible for inclusion. Twenty-eight variations were found. The prevalence of the normal branching configuration ranged from 61.2% to 92.59%; prevalence of the bovine arch type 1 ranged from 4.95% to 31.2%; while prevalence of the bovine arch type 2 ranged from 0.04% to 24%. Alongside bovine arch types 1 and 2, five concomitant variations found. The left vertebral artery arose from the aortic arch in five different locations. Prevalence of the origin of the left vertebral artery from the arch ranged from 0.17% to 15.3%. Three different combinations existed with the aberrant right subclavian artery. Within the studies examined, the prevalence of this variant ranged from 0.08% to 3.33%. The origin of the thyroid ima from the aortic arch ranged from 0.08% to 2%. Other variations which could not be classified into these six main groups were also found among the literature. These variations have clinical implications for stroke medicine, carotid surgery, radiological investigations, and various surgical specialities such as cardiothoracic, neck and thyroid surgery. They can also result in clinical symptoms such as dysphagia and dyspnoea in the case of aberrant right subclavian artery. Anatomists and clinicians alike should be aware of these variations when planning any radiological, percutaneous or surgical procedure. No ethical approval was required due to the review nature of this research.

P25Determining the contribution of small fibre pathology to pain in fibromyalgia syndrome: Preliminary data from DEFINE-FMS

Leandros Rapteas¹; Anne Marshall¹; Jamie Burgess¹; David Riley¹; Stephen Kaye¹; Andrew Marshall^1,2; Nicola Goodson¹; Marta Garcia-Finana¹; Andreas Goebel^1,2; Bernhard Frank^1,2; Uazman Alam¹

¹University of Liverpool, Liverpool and Liverpool University Hospital NHS Foundation Trust, UK; ²The Walton Centre, Liverpool, UK

Fibromyalgia (FMS) is a chronic widespread pain syndrome characterised by sensory symptoms with features of neuropathic pain. Increasing evidence implicates structural and functional small nerve fibre abnormalities in FMS, but it remains unclear how this relates to symptoms and signs. The aim of this cross-sectional study was to identify small fibre pathology (SFP) in people with FMS and investigate associated sensory phenotypes.

Twenty-nine participants with FMS and 10 healthy volunteers (HV) were examined to determine SFP with corneal confocal microscopy (CCM) by quantifying corneal nerve fibre density (CNFD), branch density (CNBD) and fibre length (CNFL). Sensory symptoms and function were evaluated with validated questionnaires and quantitative sensory testing (QST) (German DNFS), respectively. CNFL was used to stratify FMS participants into with and without SFP [SFP+ (n = 13) and SFP− (n = 16)].

Comparisons were made (HV vs. SFP− vs. SFP+) and as expected, CNFL (15.6 ± 3.6 vs. 17.1 ± 1.7 vs. 12.2 ± 2.1 mm/mm²), CNFD (26.8 ± 5.8 vs. 29.0 ± 2.4 vs. 20.0 ± 3.4 no./mm²) and CNBD (43.2 ± 15.6 vs. 42.5 ± 10.5 vs. 23.1 ± 7.1 no/mm²) were significantly lower in SFP+ (p < 0.001). VAS (0–100) demonstrated high pain intensity but did not differ between the FMS cohorts [0 (0–2.8) vs. 77.4 (32.6–85.0) vs. 74.3 (64.7–86.5) median (IQR)]. There were no significant differences in any QST parameter between SFP+ and SFP−. Mechanical pain sensitivity was significantly increased in SFP− compared to HV (p = 0.02). Although not reaching a level of significance, SFP+ showed a trend towards a greater gain of function in mechanical pain threshold compared to SFP−. Conversely, a trend towards greater pain scores (mechanical pain sensitivity) was seen in SFP− compared to SFP+.

In conclusion, SFP was present in a proportion of patients with FMS, but QST parameters were not significantly different in patients with or without SFP. Trends were observed in both mechanical pain thresholds and mechanical pain sensitivity, suggesting that patients with SFP feel pain earlier but patients without SFP report higher pain intensity. This may reflect differences in central pain processing mechanisms and should be further explored across a larger cohort of patients.

The study received ethical approval (Frenchay NREC) and informed consent was obtained.

P26How anatomy students' loss of confidence during remote learning can inform prospective blended-learning approaches

Annalise Richards¹; Dominic O'Brien²; Danya Stone²; Georga Longhurst³; Kate Dulohery⁴; Thomas Campbell⁵; Thomas Franchi⁶; Samuel Hall⁷; Scott Border⁸

¹University of Bristol, Bristol, UK; ²Brighton and Sussex Medical School, Brighton, UK; ³St George's University of London, London, UK; ⁴University of Sunderland, Sunderland, UK; ⁵University College Dublin, Dublin, Ireland; ⁶University of Sheffield, Sheffield, UK; ⁷University of Southampton, Southampton, UK; ⁸University of Glasgow, Glasgow, Scotland, UK

The educational paradigm of anatomy is continually changing in response to the Covid-19 pandemic. At many institutions, anatomists are considering transitioning their syllabuses to blended modes of delivery. It is imperative that prospective pedagogies are informed by the lessons learnt during the pandemic. Online learning often results in a more independent study experience for students. The replacement of in-person sessions with asynchronous or synchronous online sessions can impact accessibility and interactivity, and may also negatively affect students' self-perceived confidence in the subject. To assess student opinions about the opportunities for interaction they experienced during online teaching, and the resulting impact of online teaching on student confidence, a survey was distributed in June 2020 to 242 medical students in seven different institutions across the United Kingdom and Ireland. A thematic analysis of respondent data was performed to identify prevalent themes. Forty-nine percent of students indicated they were not satisfied with the level of interaction they had received (81 of 164 responses). Sixty-five percent of students felt that the Covid-19 lockdown would negatively impact their confidence in learning anatomy in the future (100 of 153 responses). Responses suggested students feel that live teaching (in-person or synchronous online delivery) offers more opportunity for interactivity and feedback compared to asynchronous online teaching. Students emphasised that the availability and approachability of instructors were of great importance, primarily because tutors could ‘quiz’ students and answer their questions. In addition, students felt their confidence was negatively impacted by both the lost opportunity to learn anatomy using human cadaveric specimens and the changes made to their assessment format. These findings indicate that instructors should act to mitigate impact on student confidence in anatomy by facilitating opportunities for both formal feedback through assessment, and informal feedback through live interactions during in-person or online synchronous teaching sessions. Moreover, student confidence during online teaching can be maintained with well-adapted curricula, effective learning resources and academic support.

Ethical approval for this study was granted by the Brighton and Sussex Medical School Research Governance Ethics Committee (ER/BSMS9GHM/1) and gatekeeper approval was provided by the additional six participating universities.

P27Introducing first-year medical students to the anatomy lab: A new approach and lessons learned

Kayleigh Scotcher; Emily Green

Newcastle University, Newcastle upon Tyne, UK

Cadaveric material has been used throughout history for the teaching of anatomy and setting foot in the anatomy lab for the first time is a defining experience for many medical students. The use of cadaveric material in anatomy education has many proven benefits, and part of its value comes from a ‘hidden’ curriculum that encourages students to develop a code of ethics, morals, and emotional resilience that they can carry through into their future practice. For many students, their first visit to the anatomy lab can be daunting and anxiety-inducing, which can make it challenging for them to reap the benefits that teaching with cadaveric material provides. A pilot introductory practical session was integrated into first-year medical students' timetable. The session aimed to create a relaxed, supportive learning environment and give students an opportunity to learn about the history and practicalities of teaching with prosections, and what to expect in future sessions in the anatomy lab. The session was split into six stations: (1) Donor body programme and embalming, (2) dissection/prosection, (3) wellbeing in the lab, (4) using the specimens, (5) educational resources and (6) 3D anatomy software. Overall, the session allowed students to transition into cadaveric anatomy education more smoothly. Since the session, we have observed higher levels of engagement and more sensitive handling of the cadaveric specimens. Although the session was successful and met our aims, there were a lot of lessons learned from this pilot and changes will be implemented in the next academic year.

P28Development of finite element models of a rodent patella as an osteochondral model

Nathan Shields¹; Bingbing Liang²; Oran Kennedy²; Claire Conway²

¹Trinity College Dublin, Dublin, Ireland; ²Royal College of Surgeons in Ireland, Dublin, Ireland

We are developing a digital framework that will enable predictions of internal stress experienced by bone and cartilage in patellae under mechanical loading in a bioreactor environment. This digital methodology includes 3D reconstructions of existing microCT data sets of 16-week-old rodent patellae. Ethical approval for animal work was previously acquired, including the microCT imaging of rodent systems. The microCT imaging data of one rodent patella was digitally reconstructed as an initial test case of the digital framework.

This pipeline converts stacks of 2D slices into 3D anatomical accurate geometries and which are discretised into finite element meshes for advanced mechanical analysis. Using the 3D Slicer software system, 2D MicroCT DICOM files were reconstructed to create a 3D digital patella geometry. This digital patella model was discretized into finite element meshes using the Meshmixer software system. The finite element meshes were imported into the FEBio software package for material property assignment and mechanical loadings (see Figure 1). Predicted internal stresses of patellar tissues under mechanical load are then calculated.

Preliminary results indicate a high degree of sensitivity in calculated stress to meshes generated.

Segmentation parameters, in particular, thresholding of Houndsfeld greyscale units (quantification metric used for microCT image description) and smoothing techniques were varied to evaluate the response of finite element mesh to an internal pressure representative of bioreactor mechanical loading regime. Additionally, ‘Shape Preserving’ feature of Meshmixer was determined to be a critical step in the pipeline. To achieve a trade-off between having too many geometric vertices and triangulations in the finite element mesh, meant that the file cumbersome for analysis, and too few vertices and finite element triangulations distorted the mesh and did not give a clear representation of the patella. A percentage range of 60%–90% gave a sufficient mesh result.

Future work with optimised finite element meshing sensitivity will enable consistency between analysis as the pipeline is applied to the wider data set (incorporating 24 left and right patella imaging from 12 rodents). Comparison between the predicted cartilage stress states in a control and ‘damaged’ model groups will be assessed with resulting finite element workflow.

P29Modulating proteoglycan synthesis in vitro for spinal cord injury regeneration

Ciara Shortiss^1,2; Siobhan S McMahon²; Linda Howard¹

¹Anatomy, School of Medicine, College of Medicine Nursing and Health Sciences, National University of Ireland Galway, Galway, Ireland; ²National University of Ireland Galway, Regenerative Medicine Institute, Galway, Ireland

Spinal cord injury (SCI) is a life-changing injury leaving a person paralysed below the injury level. Following SCI a glial scar forms containing neuronal growth inhibitory proteoglycans that hinder regeneration. SCI research has manipulated proteoglycan levels individually or altered their side chains to elicit positive effects on neuronal growth after injury. However, these strategies lack the ability to provide long-term widespread reduction of inhibitory proteoglycans. We propose to disrupt the biosynthesis of multiple proteoglycans using novel lentiviral gene therapy vectors providing long-term widespread control over proteoglycan production in order to aid neuronal outgrowth after SCI. The enzymes xylosyltransferase I and II (XTI, XTII) catalyse the initial and rate-limiting step in O-linked proteoglycan synthesis. XTI reduction by a deoxyribozyme-enhanced SCI repair providing proof of concept. We have developed lentiviral vectors to deliver short hairpin RNAs (shRNA) targeting XTI and XTII mRNA to knockdown these enzymes and thereby restrict all O-linked proteoglycan production. A lentiviral-shRNA vector is also being assessed to target Chondroitin Sulphate N-acetylgalactoasminyl-transferase-1 (Csgal1) that is common to chondroitin sulphate proteoglycan (CSPG) and Dermatin Sulphate proteoglycan synthesis only. The ability of these vectors to knockdown their enzymatic targets was assessed in rat Neu7 and B104 cell lines. qPCR revealed a 70%–80% reduction in target mRNA when compared to cells transduced with a lentiviral vector carrying a nontargeting shRNA. Cells were immuno-stained for CS56 to assess CSPG expression. Semi-quantitative fluorescence intensity analysis of CS56 staining is ongoing. Towards the development of an in vitro, SCI scarring model as a potential platform for trialling gene therapy approaches, the expression of these enzymes was observed in uninjured/injured Mixed Glial Culture cells (MGC) obtained from P3/4 Sprague Dawley rat pup spinal cords. These were inflamed with LPS and/or scratch in cell monolayer. qPCR analysis revealed XTI and XTII mRNA was upregulated after MGC inflammation. Pending results from immunostaining may confirm that increased XTI and XTII expression is seen in conjunction with an increase in inflammation and scarring markers. All animal housing and tissue harvesting in this study were approved by the Animal Care Research Ethics Committee, National University of Ireland Galway.

P30The role of regulated synaptic vesicle release from cortical layer 5 pyramidal neurons in the development of cortical and subcortical GABAergic interneurons in mice

Florina P Szabó; Anna Hoerder-Suabedissen; Veronika Sigutova; Anna Schneider; Zoltán Molnár

Department of Physiology, Anatomy and Genetics, University of Oxford, Sherrington Building, Sherrington Road, Oxford, UK

The proper functioning of neural networks in the cerebral cortex is dependent upon the precise ratio between glutamatergic pyramidal cells and inhibitory GABAergic interneurons. Perturbations in pyramidal cell function, numbers, and activity have been shown to affect the survival of GABAergic interneurons that can lead to aberrant network formation and pathological brain functioning. However, the cellular and molecular mechanisms that enable pyramidal neurons to regulate the number of interneurons are unknown. Therefore, we investigated whether synaptic transmission in infragranular pyramidal neurons may control the development of GABAergic interneurons.

To examine the role of pyramidal neuron activity in the survival of GABAergic interneurons, we abolished synaptic vesicle release in a subset of cortical layer 5 pyramidal neurons using a SNAP25 conditional knock-out strain. The Rbp4-Cre+;Ai14;Snap25fl/fl mouse model blocks regulated vesicle release in a subset of layer 5 projection neurons allowing us to investigate the selective role of deep-layer pyramidal neurons in the maturation of inhibitory neurons. We examined the density and laminar distribution of parvalbumin-expressing interneurons during development in selected cortical and subcortical regions that are output targets of the silenced layer 5 projection neurons. Chronic abolition of SNAP25 from Rbp4-Cre+ layer 5 pyramidal cells increased the density of cortical PV+ interneurons at P14 within the primary motor and somatosensory cortex in the cKO brains. No such alterations in the density of cortical PV+ interneurons were observed at P21, but subcortical PV-expressing cells increased in the external segment of the globus pallidus and slightly decreased in the superior colliculus in the cKO animals at P21. Alterations in the density of PV+ interneurons therefore differ between cortical and subcortical areas in the layer 5-silenced animals. This suggests area-specific differences and differential modulations in how GABAergic interneurons may be affected by the abolition of regulated synaptic vesicle release from a subset of layer 5 pyramidal neurons. Neural activity of infragranular cortical pyramidal cells can therefore shape the development of inhibitory circuits by differentially regulating PV+ interneurons depending on their projection site. This research is supported by the Anatomical Society. All experimental procedures were conducted under a project licence granted by the UK Home Office and in accordance with the rules and regulations of the Animals (Scientific Procedures) Act 1986. Animal work was approved by the Named Animal Care and Welfare Officer and carried out at the Biomedical Services of the University of Oxford adhering to the local regulations pertaining to the use of animals for regulated procedures.

P31Potted History: A case of imperforate anus

Siobhan Ward; Philomena McAteer; Evi Numen; Martina Hennessy

Anatomy Museum, School of Medicine, Trinity College Dublin, Ireland

While cataloguing and conserving the Wet Specimen collection in the Old Anatomy Museum at Trinity College Dublin, I noted a specimen labelled; Mesial section through the pelvis of a female child born with imperforate anus. An attempt to reach the gut from below failed and colotomy was performed but the child died in a few days. The specimen was given and described by Dr F.W. Kidd. Although this specimen has been in the collection for many years, there was no indication of how long it had been here or why Dr Kidd had given the specimen to TCD. A search revealed a journal article by Dr Kidd describing this case which brings new meaning to this 127-year-old museum specimen. ‘The case which I wish to bring under your notice this evening is one of considerable interest to the embryologist, the anatomist, the surgeon, and the obstetrician. The interest in this case is increased by the fact that it is accompanied by a frozen section of the parts, which has been most beautifully prepared and mounted by Dr Dixon, of the Trinity College School of Anatomy’. Dr Kidd describes the challenges he encounters trying to save the life of this child. It is a poignant story of a mother in her 12th pregnancy, a child who lived for 10 days, a doctor disappointed at his efforts to save the child and ultimately the need to record the condition of Imperforate Anus by retaining and preserving the human remains ‘because it might fall to the lot of any obstetric surgeon to treat some case exactly similar to the one, I have just described’.