Multiple sclerosis (MS) is a chronic inflammatory disease of the central nervous system (CNS) characterized by demyelination, blood–brain barrier disruption, and leukocyte infiltration. The transmembrane glycoprotein cluster of differentiation 44 (CD44) has been implicated in neuroinflammation, but its functional role remains unclear. Here, we examined CD44 expression and function across both non–immune-mediated and immune-mediated MS animal models, including cuprizone-induced demyelination, experimental autoimmune encephalomyelitis (EAE), and combined cuprizone/EAE (Cup/EAE), as well as in human MS tissue and cerebrospinal fluid (CSF), using immunohistochemistry, flow cytometry and enzyme-linked immunosorbent assay. CD44 expression increased in parallel with demyelination and was most pronounced in the forebrain of Cup/EAE mice, where it localized to perivascular cuffs and lesion-associated parenchyma. CD44 expression co-localized to IBA1⁺ microglia/monocytes and CD3⁺ T cells. Flow cytometry analyses revealed high CD44 expression on myeloid-derived suppressor cells and regulatory T cells, which further increased upon immune activation. On the functional level, Cd44 -deficient mice exhibited exacerbated disease severity in EAE, accompanied by increased immune cell infiltration and tissue damage. In human MS samples, CD44 expression and soluble CD44 levels in CSF were significantly elevated. Notably, CD44 upregulation was also observed in other neurological disease models, including ischemic stroke and APPswe/PS1dE9 mice, a model of Alzheimer’s disease. Together, these findings identify CD44 as a conserved marker of neuroinflammatory activity and a context-dependent regulator of neuroinflammation with partially protective functions, rather than an exclusively pro-inflammatory molecule, highlighting its potential relevance in MS and related neurological disorders.

Niemann-Pick type C disease (NPC) is a rare lysosomal storage disorder belonging to the group of sphingolipidoses and is caused by a genetic defect affecting cholesterol trafficking. Since other sphingolipidoses with lipid accumulations show disrupt bone, this study investigated bone structure in an Npc1 mouse model and assessed whether pharmacological treatments (miglustat, 2-hydroxypropyl-β-cyclodextrin [HPßCD], and combination therapy including allopregnanolone) affected it. Femora from Npc1-/- mice of postnatal day (P) 65 were analysed using histology, histomorphometry and micro-CT. Additionally, femur and vertebral bodies of mice from P30, P40 and P65 were examined by real-time RT-PCR. Histomorphometric findings revealed a significantly reduced relative bone area in female Npc1-/- mice compared to wild-type mice. Micro-CT analysis confirmed this by demonstrating deteriorated trabecular bone structures in female Npc1-/- mice. Following treatment, particularly with combination therapy, an improvement in the bone microarchitecture was observed. Differences relative to wild-type mice were often no longer detectable. Furthermore, there was some evidence that combi therapy also increased the relative numbers of osteoblasts and osteoclasts. Since real-time RT-PCR indicated low expression of osteoclast and osteocyte targets cathepsin K and connexin-43, respectively, a stimulation of bone cells might decelerate postnatal disease progression. While at P30, sphingosine-kinase-1 (SphK1) expression was increased in female Npc1-/- mice, it decreased in femur at P40 and in vertebral bodies at P65. This decline was not measured in male Npc1-/- mice revealing a sex-dependent decline of bone structures in female Npc1-/- mice. Overall, disease-modifying treatment regimens targeting lipid storage improved bone microarchitecture in a sex-dependent manner.

In upper limb amputees implantation of prostheses equipped with electrodes to innervate respective musculature might improve sensitivity and life quality. Besides different types of prostheses being available, there is still a need for devices that provide more comfort and functionality to patients. Prior to prosthesis implantation magnetic resonance imaging (MRI) or ultrasound are suitable methods for imaging peripheral nerves but are limited in description of nerve dimension. Using X-ray micro-computed tomography (micro- CT) exact dimensions of nerves can be obtained. However, since ex vivo micro-CT analysis on human nerves is rarely possible, the underlying study analyzed whether porcine nerve tissue is comparable to human nerve tissue and thus suitable for nerve electrode implantation studies. Therefore, micro-CT analysis was performed at 10 different proximal to distal sections of porcine Nervus ulnaris, Nervus medianus and Nervus radialis to determine the diameters of nerves and fascicles (n = 1). The diameters of the porcine Nervus ulnaris, Nervus medianus and Nervus radialis were 2.99 ± 0.28 mm, 4.40 ± 0.38 mm and 7.89 ± 0.98 mm, respectively. The diameters of the human Nervus ulnaris, Nervus medianus and Nervus radialis were measured at 10 different regions using a caliper and were 2.93 ± 0.71 mm, 3.65 ± 1.06 mm and 2.94 ± 1.11 mm, respectively (n = 2). Fascicular diameters of porcine Nervus ulnaris, Nervus medianus and Nervus radialis were 0.22 ± 0.09 mm, 0.26 ± 0.06 mm and 0.29 ± 0.07 mm, respectively. Our preliminary results showed that nerve diameters were similar between pigs and humans. Espcially, further analyses of porcine Nervus ulnaris, Nervus medianus and Nervus radialis are necessary to conclude whether porcine nerve tissue is suitable for electrode implantation studies.

Regional anatomy teaching forms a cornerstone of undergraduate medical education. Owing to an increase in teaching and learning content throughout the medical curriculum in recent years, contact hours and overall course durations in anatomy are under review worldwide. This study aimed to assess whether shortening the course content duration impacts learning gain and the ability to identify anatomical structures correctly. Undergraduate medical students of the Johannes Kepler University Linz (JKU; n = 310) and at the Medical University of Graz (MUG; n = 156) participating in regional anatomy courses were included. Whole body regional anatomy courses, including hands-on dissection and accompanying lectures, were delivered over one or three months. Course content and examination mode were kept consistent, while the duration of knowledge delivery was one or three months, respectively. Objective structured practical examinations (OSPE) were then carried out on prosections for the neck, thorax, and abdomen. 3-month course exposure resulted in significantly higher OSPE scores for the neck (49 vs. 37%), thorax (65 vs. 54%), and abdomen (65 vs. 45%), respectively. Further evaluation of the utility of different embalming types yielded higher 3-month scores in the neck and thorax regions with Thiel-embalmed tissues and thorax and abdomen regions in ethanol-glycerin-embalmed tissues. Course exposure over a more extended period, like three months, appears to be highly beneficial.

Proximal femur fracture risk depends on subject-specific factors such as bone mineral density and morphological parameters. Here, we aim to analyze the dependency of the femoral strength on sixteen morphological parameters. Therefore, finite-element analyses of 20 human femurs during stumbling and lateral falls on the hip were conducted. Pearson correlation coefficients were calculated and morphological parameters with significant correlations were examined in principal component analysis and linear regression analysis. The dependency of the fracture strength on morphological parameters was more pronounced during lateral falls on the hip compared to stumbling. Significant correlations were observed between the neck shaft angle (r = −0.474), neck diameter (r = 0.507), the true distance between the femoral head center and femoral shaft axis (r = 0.459), and its projected distance on the frontal plane (r = 0.511), greater trochanter height (r = 0.497), and distance between the femoral head center and a plane parallel to the frontal plane containing the projection of the femoral head center to the femoral neck axis (r = 0.669). Principal component analysis was strongly weighted by parameters defining the lever arm during a lateral fall as well as the loaded cross-section in the femoral neck.

Background:Minimally invasive glaucoma surgery (MIGS) has become an important treatment approach for primary open angle glaucoma. Restoration of aqueous humour drainage by means of alloplastic implants represents a promising treatment option and is itself subject of methodological development. An adequate positioning in the targeted tissue regions is essential is important for the performance of our in-house developed Rostock glaucoma microstent (RGM). The aim of this study was to evaluate the applicability of two animal models and human donor eyes regarding RGM placement. Methods:Eyes were obtained from rabbits, pigs, and human body donations. After orbital exenterations, RGMs were placed in the anterior chamber draining in the subconjunctival space. X-ray contrast was increased by incubation in aqueous iodine solution for subsequent detailed micro-computed tomography (micro-CT)-based visualization and analysis. Results:In contrast to the human and porcine eyes, the stent extended far to the posterior pole with a more pronounced curvature along the globe in the rabbit eyes due to their smaller size. However, dysfunctional deformations were not depicted. Adequate positioning of the stent's inflow area in the anterior chamber and the outflow area in the Tenon space was achieved in both the animal models and the human eye. Conclusions:Micro-CT has proven to be a valuable tool for postoperative ex vivo evaluation of glaucoma drainage devices in its entire complexity. With regard to morphology, the porcine eye is the ideal animal model to test implantation procedures of the RGM. Nevertheless, rabbit eye morphology facilitates successful implantation results and provides all prerequisites for preclinical animal studies.

Background and Objectives: Facial vascular anatomy plays a pivotal role in both physiological context and in surgical intervention. While data exist on the individual course of the facial artery and vein, to date, the spatial relationship of the vasculature has been ill studied. The aim of this study was to assess the course of facial arteries, veins and branches one relative to another. Materials and Methods: In a total of 90 halved viscerocrania, the facial vessels were injected with colored latex. Dissection was carried out, the relation of the facial vessels was studied, and the distance at the lower margin of the mandible was measured. Furthermore, branches including the labial and angular vessels were assessed. Results: At the base of the mandible, the facial artery was located anterior to the facial vein in all cases at a mean distance of 6.2 mm (range 0–15 mm), with three cases of both vessels adjacent. An angular vein was present in all cases, while an angular artery was only present in 34.4% of cases. Conclusions: The main trunk of the facial artery and vein yields a rather independent course, with the facial artery always located anterior to the vein, while their branches, especially the labial vessels, demonstrate a closer relationship.

Background: In the achievement of optimal learning outcomes, knowledge retention presents a major concern for medical students and educators. Practical dissection courses facilitate the consolidation of knowledge of anatomy. Previously, it was shown that a regional anatomy dissection course is more beneficial over a 3-month than a 1-month duration for gathering pre examination knowledge. This study aimed to assess if follow-up anatomy interventions help consolidate regional anatomy knowledge and facilitate knowledge retention of undergraduate medical students. It was hypothesized that knowledge retention could be enhanced using post-dissection teaching interventions. Methods: Upon completion of the dissection course, Objective Structured Practical Examinations (OSPEs) were performed for the neck, thorax, and abdomen immediately before the start of the oral examinations, with follow-ups at 6 and 12 months. Between each of the examinations, virtual and in-person lectures and seminars on (radiologic) anatomy and pathology were held, including Cinematic Rendering, but without additional teaching on human tissues. Results: Significant improvements were observed for knowledge of the neck and abdomen regions in the 6- and 12-month follow-up OSPEs. The effects of knowledge gain were less marked in ethanol-glycerin- than in Thiel-embalmed tissues. Student perceptions regarding tissue quality correlated positively with their assessment of tissue suitability for examination preparation. In conclusion, even anatomy teaching interventions not utilizing human tissues may help consolidate and improve regional anatomy knowledge over a one-year term. Conclusion: Knowledge retention can be enhanced by accompanying virtual with physical teaching interventions.

BackgroundNiemann-Pick disease type C1 (NPC1, MIM 257220) is a heritable lysosomal storage disease characterized by a progressive neurological degeneration that causes disability and premature death. A murine model of Npc1−/− displays a rapidly progressing form of Npc1 disease, which is characterized by weight loss, ataxia, and increased cholesterol storage. Npc1−/− mice receiving a combined therapy (COMBI) of miglustat (MIGLU), the neurosteroid allopregnanolone (ALLO) and the cyclic oligosaccharide 2-hydroxypropyl-β-cyclodextrin (HPßCD) showed prevention of Purkinje cell loss, improved motor function and reduced intracellular lipid storage. Although therapy of Npc1−/− mice with COMBI, MIGLU or HPßCD resulted in the prevention of body weight loss, reduced total brain weight was not positively influenced.MethodsIn order to evaluate alterations of different brain areas caused by pharmacotherapy, fresh volumes (volumes calculated from the volumes determined from paraffin embedded brain slices) of various brain structures in sham- and drug-treated wild type and mutant mice were measured using stereological methods.ResultsIn the wild type mice, the volumes of investigated brain areas were not significantly altered by either therapy. Compared with the respective wild types, fresh volumes of specific brain areas, which were significantly reduced in sham-treated Npc1−/− mice, partly increased after the pharmacotherapies in all treatment strategies; most pronounced differences were found in the CA1 area of the hippocampus and in olfactory structures.DiscussionVolumes of brain areas of Npc1−/− mice were not specifically changed in terms of functionality after administering COMBI, MIGLU, or HPßCD. Measurements of fresh volumes of brain areas in Npc1−/− mice could monitor region-specific changes and response to drug treatment that correlated, in part, with behavioral improvements in this mouse model.

A three-dimensional (3D) understanding of muscle attachment footprints became increasingly relevant for musculoskeletal modeling. The established method to project attachments as points ignores patient-specific individuality. Research focuses on investigating certain muscle groups rather than comprehensively studying all muscles spanning a joint. Therefore, we present a reliable method to study several muscle attachments in order to reconstruct the attachment sites in 3D based on CT imaging for future applications in musculoskeletal modeling. For the present feasibility study, 23 knee-related muscle attachments were CT-scanned postmortem from four nonadipose male specimens. For this, the specific muscle attachments were dissected and marked with a barium sulfate containing paint (60 g BaSO4 in 30 mL water and 10 mL acrylic paint). Subsequently, bone geometries and muscle attachments were reconstructed and evaluated from CT datasets. Bone morphology and footprint variations were studied. Exemplarily, variations were high for pes anserinus insertions (mean 56%) and the origins of M. biceps femoris (mean 54%). In contrast, the origins of the vastus muscles as well as the insertion of the Achilles tendon showed low variation (mean 9% and 13%, respectively). Most attachment sites showed variation exceeding the individuality of bone morphology. In summary, the present data were consistent with the few published studies of specific muscle footprints. Our data shed light on the high variability of muscle attachments, which need to be addressed when studying muscle forces and movements through musculoskeletal modeling. This is the first step to achieving a more profound understanding of muscle morphology to be utilized in numerical simulations.

Background and Objectives: The facial vein is the main collector of venous blood from the face. It plays an important role in physiological as well as pathological context. However, to date, only limited data on the course and tributaries of the facial vein are present in contemporary literature. The aim of this study was to provide detail on the course and the tributaries of the facial vein. Materials and Methods: In 96 sides of 53 body donors, latex was injected into the facial vein. Dissection was carried out and the facial vein and its tributaries (angular vein, ophthalmic vein, nasal veins, labial veins, palpebral veins, buccal and masseteric veins) were assessed. Results: The facial vein presented a textbook-like course in all cases and crossed the margin of the mandible anterior to the masseter in 6.8% of cases, while being located deep to the zygomaticus major muscle in all cases and deep to the zygomaticus minor in 94.6% of cases. Conclusions: This work offers detailed information on the course of the facial vein in relation to neighboring structures, which shows a relatively consistent pattern, as well as on its tributaries, which show a high variability.

ZusammenfassungDie röntgenbasierte Mikrocomputertomografie (Mikro-CT) bietet ein weitgehend zerstörungsfreies Bildgebungsverfahren zur Visualisierung und Analyse interner Strukturen im Ex-vivo-Auge mit hohen Auflösungen. Im Gegensatz zu anderen hochauflösenden Imaging-Verfahren ermöglicht die Mikro-CT die räumliche Erfassung größerer und komplexerer Gewebestrukturen wie der vorderen Augenkammer. Spezielle Kontrastierungsmethoden helfen, die Absorptionseigenschaften von ansonsten nur schwach röntgenopaken Weichteilgeweben zu verstärken. Die vor allem in der Rasterelektronenmikroskopie verwendete Kritisch-Punkt-Trocknung (KPT) bietet ein zusätzliches Werkzeug zur Verbesserung der differenziellen Kontrasteigenschaften im Weichteilgewebe. Bei der Darstellung intraossärer Weichteilgewebe, wie den ableitenden Tränenwegen, liefert die Probenbehandlung durch Entkalkung mit Ethylendiamintetraessigsäure und anschließender KPT gute Ergebnisse für die Mikro-CT. Die Mikro-CT kann für verschiedenste Fragestellungen in 1. Grundlagenforschung, 2. anwendungsbezogenen Studien in der Augenheilkunde (z. B. Evaluierung der präklinischen Applikation von Microstents zur Glaukombehandlung oder Analyse der Positionierung von Intraokularlinsen), aber auch 3. als Ergänzung für die ophthalmologische Histopathologie eingesetzt werden.

Chronic otitis media is often connected to Eustachian tube dysfunction. As successful treatment cannot be guaranteed with the currently available options, the aim is to develop a stent for the Eustachian tube (ET). Over the course of this development, different prototypes were generated and tested in ex vivo experiments. Four different prototypes of an ET stent and one commercially available coronary stent were implanted in the ET of seven human donor bodies. The position of the stents was verified by cone beam CT. The implanted ETs were harvested, embedded in resin and ground at 200 µm steps. Resulting images of the single steps were used to generate 3D models. The 3D models were then evaluated regarding position of the stent in the ET, its diameters, amount of squeezing, orientation of the axes and other parameters. Virtual reconstruction of the implanted ET was successful in all cases and revealed one incorrect stent placement. The cross-section increased for all metal stents in direction from the isthmus towards the pharyngeal orifice of the ET. Depending on the individual design of the metal stents (open or closed design), the shape varied also between different positions along a single stent. In contrast, the cross-section area and shape remained constant along the polymeric prototype. With the current investigation, insight into the behavior of different prototypes of ET stents was gained, which can help in defining the specifications for the intended ET stent.

Niemann-Pick Type C1 (NPC1, MIM 257220) is a rare, progressive, lethal, inherited autosomal-recessive endolysosomal storage disease caused by mutations in the NPC1 leading to intracellular lipid storage. We analyzed mostly not jet known alterations of the weights of 14 different organs in the BALB/cNctr-Npc1m1N/-J Jackson Npc1 mice in female and male Npc1+/+ and Npc1−/− mice under various treatment strategies. Mice were treated with (i) no therapy, (ii) vehicle injection, (iii) a combination of miglustat, allopregnanolone, and 2-hydroxypropyl-ß-cyclodextrin (HPßCD), (iv) miglustat, and (v) HPßCD alone starting at P7 and repeated weekly throughout life. The 12 respective male and female wild-type mice groups were evaluated in parallel. In total, 351 mice (176 Npc1+/+, 175 Npc1−/−) were dissected at P65. In both sexes, the body weights of None and Sham Npc1−/− mice were lower than those of respective Npc1+/+ mice. The influence of the Npc1 mutation and/or sex on the weights of various organs, however, differed considerably. In males, Npc1+/+ and Npc1−/− mice had comparable absolute weights of lungs, spleen, and adrenal glands. In Npc1−/− mice, smaller weights of hearts, livers, kidneys, testes, vesicular, and scent glands were found. In female Npc1−/− mice, ovaries, and uteri were significantly smaller. In Npc1−/− mice, relative organ weights, i.e., normalized with body weights, were sex-specifically altered to different extents by the different therapies. The combination of miglustat, allopregnanolone, and the sterol chelator HPßCD partly normalized the weights of more organs than miglustat or HPßCD mono-therapies.

X-ray-based micro-computed tomography (micro-CT) is a largely non-destructive imaging method for the visualisation and analysis of internal structures in the ex vivo eye and affords high resolution. In contrast to other high-resolution imaging methods, micro-CT enables spatial recording of larger and more complex tissue structures, such as the anterior chamber of the eye. Special contrasting methods help to enhance the absorption properties of soft tissue, that is otherwise only weakly radiopaque. Critical point drying (CPD), as primarily used in scanning electron microscopy, offers an additional tool for improving differential contrast properties in soft tissue. In the visualisation of intraosseous soft tissue, such as the efferent lacrimal ducts, sample treatment by decalcification with ethylenediaminetetraacetic acid and subsequent CPD provides good results for micro-CT. Micro-CT can be used for a wide range of questions in 1. basic research, 2. application-related studies in ophthalmology (e.g. evaluation of the preclinical application of microstents for glaucoma treatment or analysis of the positioning of intraocular lenses) but also 3. as a supplement to ophthalmological histopathology.

Background and Objectives: Anastomoses of the extracranial and intracranial venous system have been described in the literature. The presence of such anastomoses may facilitate a possible spread of infection into the dural venous sinuses. However, the frequency and relevance of such anastomoses is highly debated. The aim of this study was to quantify frequencies of anastomoses between the facial vein and the dural venous sinuses. Materials and Methods: In 32 sides of 16 specimens, latex was injected into the facial vein. Dissection was carried out to follow and described these anastomoses, yielding the presence of latex in the intracranial venous system. Results: In 97% of cases, a dispersal of latex into the cavernous sinus as well as anastomoses was observed. A further dispersal of latex into other dural venous sinuses was found at rates ranging between 34% (transverse sinus)—88% (superior petrosal sinus), respectively. Conclusions: The presence of anastomoses between the extracranial and intracranial venous system in a majority of cases needs to be considered when dealing with pathologies as well as procedures in the facial region.

Anatomical dissection is known to serve as an integral tool in teaching gross anatomy, including postgraduate training. A variety of embalming techniques exist, resulting in different haptic and optical tissue properties. This study aimed to objectify learning outcomes and medical student perceptions related to the use of two widely used embalming techniques, namely Thiel and ethanol-glycerin embalming. Between 2020 and 2022, first- and second-year medical students enrolled in the course on topographic anatomy participated in this study. Objective structured practical examinations were carried out for the head, neck, thorax, abdomen, pelvis, and extremity regions following regional dissection just before the oral examinations began. Six to ten numbered tags were marked in prosections of each region in Thiel- and ethanol-glycerin-embalmed specimens. Following the examinations, the students were surveyed regarding the suitability of the two embalming techniques with respect to preservation, colorfastness, tissue pliability, and the suitability in preparing for their anatomy examinations. Consistently higher scores were achieved for the thoracic and abdominal regions in ethanol-glycerin-embalmed specimens when compared to Thiel. No benefit was found for Thiel-embalmed upper or lower extremities. Tissues embalmed with ethanol-glycerin were rated higher for preservation and suitability to achieve the learning objectives, tissue pliability was rated higher for Thiel-embalmed tissues. Ethanol-glycerin embalming appears to offer certain advantages for undergraduate students in recognizing visceral structures, which may align with students' ideas on tissue suitability for their learning. Consequently, the benefits reported for Thiel embalming for postgraduate study unlikely reflect its suitability for novices.

An unfulfilled pregnancy is often due to impaired patency of the female Fallopian tubes. To circumvent tubal obstruction, cost-intensive in vitro fertilisation (IVF) is currently indicated. The only therapeutic treatment concepts available are transvaginal tubal lavage/catheterization or laparoscopy with minimally invasive or complex surgical tubal reconstruction, which are associated with side effects. The development of new and cost-effective non- or minimally invasive therapeutic concepts that can restore the patency of the Fallopian tubes would be key in the treatment of female infertility and can fulfil the desire to have children. Therefore, in the present work, ex vivo anatomical studies are carried out on various laboratory mammals (pigs, rabbits, guinea pigs). Using these animal models, it was also evaluated whether a sensor-ureterorenoscope can be inserted through the whole female reproductive tract to the Fallopian tubes. This device will be used for endoscopically guided implantation of a novel tubal microstent prototype via its tailor-made delivery system into the isthmus region of the Fallopian tubes in upcoming studies. This work serves to identify an optimal species for a longitudinal animal study, in which the feasibility as well as the tissue reaction to the implant will be evaluated.

In Parkinson’s disease, hypercholinism in the striatum occurs, with the consequence of disturbed motor functions. Direct application of Botulinum neurotoxin-A in the striatum of hemi-Parkinsonian rats might be a promising anticholinergic therapeutic option. Here, we aimed to determine the spread of intrastriatally injected BoNT-A in the brain as well as the duration of its action based on the distribution of cleaved SNAP-25. Rats were injected with 1 ng of BoNT-A into the right striatum and the brains were examined at different times up to one year after treatment. In brain sections immunohistochemically stained for BoNT-A, cleaved SNAP-25 area-specific densitometric analyses were performed. Increased immunoreactivity for cleaved SNAP-25 was found in brain regions other than the unilaterally injected striatum. Most cleaved SNAP-25-ir was found in widespread areas ipsilateral to the BoNT-A injection, in some regions, however, immunoreactivity was also measured in the contralateral hemisphere. There was a linear relationship between the distance of a special area from the injected striatum and the time until its maximum averaged immunoreactivity was reached. Moreover, we observed a positive relationship for the area-specific distance from the injected striatum and its maximum immunoreactivity as well as for the connection density with the striatum and its maximum immunoreactivity. The results speak for a bidirectional axonal transport of BoNT-A after its application into the striatum to its widespread connected parts of the brain. Even one year after BoNT-A injection, cleaved SNAP-25 could still be detected.