Annals of Anatomy-Anatomischer Anzeiger最新文献

Background

Body donation is integral to anatomy education, but procurement can be ethically fraught. While voluntary donation is preferred, the use of unclaimed bodies, although considered unethical, is a primary means for body procurement in some countries. This mixed methods study examined historical trends and anatomy technical staff perspectives on body donation in two Zimbabwean medical schools.

Methodology and main findings

In Phase 1, 194 cadaver paper records from January 1984 to January 2021 were reviewed. Unclaimed bodies accounted for 67% while 33% (all white Zimbabweans) were voluntarily donated. Most cadavers were black Africans (62.4%) followed by white Zimbabweans (34.0%). Race was not indicated in seven (3.6%) records. In Phase 2, semi-structured interviews were conducted with seven technicians responsible for sourcing cadavers at the two institutions. Data were thematically analysed resulting in the development of eight themes, arranged into three domains. Cadaver procurement themes related to (1) cadaver source, (2) adherence to procurement guidelines, (3) screening for suitability, and (4) cultural and religious beliefs. Cadaver embalmment focused on (5) embalming practices, and (6) hospital mortuary-based embalming. Finally, (7) disposal processes and (8) resource constraints were found to influence cadaver disposal practices.

Conclusions

Contrary to best practice, there is continued reliance on the use of unclaimed bodies to support anatomy education in the two Zimbabwean medical schools. Improving the ethical sourcing of bodies requires increased efforts to educate all Zimbabweans, especially the black majority, about the role and importance of voluntary body donation in medical education. Additionally, well-structured, and well-resourced body donation programs could enhance ethical procurement.

Background:

A reliable estimation of time since death can be important for the law enforcement authorities. The compound method encompassing supravital reactions such as the chemical excitability of the iris can be used to further narrow intervals estimated by temperature-based methods. Postmortem iris excitability was mostly assessed by parasympatholytic or parasympathomimetic substances. Little is known regarding sympathomimetic agents. The present study aims to describe the postmortem iris excitability using the sympathomimetic drug phenylephrine.

Methods:

Cadavers were included after body donors gave written informed consent during lifetime. Exclusion criteria were known eye disease, or a postmortem interval exceeding 26 hours. A pupillometer with a minimum measurement range of 0.5 mm was used to determine the horizontal pupil diameter before and 20 minutes after the application of phenylephrine. Increase in pupil diameter was labeled as positive reaction, unchanged pupil diameter was labeled as negative reaction, and decrease in pupil diameter was labeled as paradox reaction.

Results:

30 eyes from 16 cadavers (median age = 80.0; 9 males, 7 females) were examined. Initial pupil size was in median 3.5 mm (interquartile range [IQR]: 3.0–4.5 mm) and progressed to 4.0 mm (IQR: 3.5–5.0 mm) 20 minutes after drug instillation. The achieved pupil diameter difference comprised in median 0.5 mm (IQR: 0.0–1.0 mm). A positive reaction was observed in 21 cases. Negative reactions were observed in 5 cases and paradox reactions in 4 cases. Overall, there was a statistically significant difference in diameter between the initial and the reactive pupil (P = 0.0002).

Conclusion:

Although relatively rarely used, sympathomimetic drugs seem to be eligible for chemical postmortem iris excitability. Currently, assessment of postmortem iris excitability usually only involves parasympatholytic and parasympathomimetic agents. The findings of the present study give a hint that the application of a third agent with a sympathomimetic mechanism of action could provide additional information. Further studies assessing such a triple approach in the compound method in comparison with the current gold standard for estimation of time since death are mandatory to ensure reliable results.

Neural guidance proteins participate in motor neuron migration, axonal projection, and muscle fiber innervation during development. One of the guidance proteins that participates in axonal pathfinding is Netrin-1. Despite the well-known role of Netrin-1 in embryogenesis of central nervous tissue, it is still unclear how the expression of this guidance protein contributes to primary innervation of the periphery, as well as reinnervation. This is especially true in the larynx where Netrin-1 is upregulated within the intrinsic laryngeal muscles after nerve injury and where blocking of Netrin-1 alters the pattern of reinnervation of the intrinsic laryngeal muscles. Despite this consistent finding, it is unknown how Netrin-1 expression contributes to guidance of the axons towards the larynx. Improved knowledge of Netrin-1’s role in nerve regeneration and reinnervation post-injury in comparison to its role in primary innervation during embryological development, may provide insights in the search for therapeutics to treat nerve injury. This paper reviews the known functions of Netrin-1 during the formation of the central nervous system and during cranial nerve primary innervation. It also describes the role of Netrin-1 in the formation of the larynx and during recurrent laryngeal reinnervation following nerve injury in the adult.

Background

The sural nerve is a somatosensory nerve that provides sensation to the posterolateral aspect of the lower leg and the lateral part of the ankle and foot. Due to its location and anatomical properties, it is often used as an autologous nerve graft. However, the nerve harvest can be complicated by the presence of side branches. The objective of this study was to investigate the anatomy of the sural nerve and to map its side branches. This information can be used to predict the localization of separate incisions during the stair-step incisions technique for nerve harvest, thereby reducing the risk of complications.

Methods

The study involved the dissection of 50 adult cadaveric legs (25 left and 25 right) obtained from 27 Central European cadavers. The focus of the dissection was to identify the sural nerve, small saphenous vein, and surrounding anatomical structures. Detailed measurements were taken on the side branches of the sural nerve, tributaries of the small saphenous vein, and their interrelationship.

Results

The average number of sural nerve side branches in a single leg was 4.2±1.9. These side branches were categorized into six groups based on their location and course: mediodistal, medioproximal, lateroproximal, laterodistal, medial perpendicular, and lateral perpendicular. Specific patterns of combination of these side branches were also identified and described. The branching point of the sural nerve was found to be 5.8±2.7 cm proximal to the lateral malleolus, whereas the small saphenous vein branching point was located more distally, 4.5 ± 2.8 cm proximal to the lateral malleolus. The highest density of sural nerve side branches was found 2.1–6.0 cm above the lateral malleolus.

Conclusion

This study presents valuable data about the relationship between the sural nerve and the surrounding anatomical structures in the distal part of the leg, including the identification of its side branches and their relevance during nerve harvest procedures. On the basis of the most frequent locations of side branches, a three-incision-technique for nerve harvest is proposed.

In this manuscript, the structure of the human choroid is reviewed with emphasis of the macro- and microscopic anatomy including Bruch’s membrane, choriocapillaris, Sattler’s and Haller’s layer, and the suprachoroid. We here discuss the development of the choroid, as well as the question of choroidal lymphatics, and further the neuronal control of this tissue, as well as the pathologic angiogenesis. Wherever possible, functional aspects of the various structures are included and reviewed.

Background

The sphenoid bone is an irregular, unpaired, symmetrical bone located in the middle of the anterior skull and is involved in craniofacial growth and development. Since the morphology of Sella turcica (ST) is associated with different craniofacial patterns, this study aimed to investigate if there is a correlation between ST morphology on the one hand and sagittal craniofacial patterns on the other hand.

Methods

This study was conducted with a convenience sample that included Brazilian individuals undergoing orthodontic treatment. Lateral cephalograms were used to evaluate the calcification pattern and morphology of ST, as well as skeletal class by analyzing the ANB angle. Pearson's chi-square test with Bonferroni post-hoc test was performed to evaluate the association between ST calcification pattern and morphology, and anteroposterior skeletal malocclusion. The established significance level was 0.05.

Results

The study collective was comprised of 305 orthodontic patients (178 (58.4 %) female, 127 (41.6 %) male), who had a mean age of 23.2 (±10.6) years. 131 participants (42.9 %) presented skeletal class I, 142 (46.6%) skeletal Class II, and 32 (10.5%) had a skeletal class III. The degree of prognathism of the mandible showed a homogenous distribution within the study collective (91 (29.9 %) orthognathic, 100 (32.9 %) retrognathic, 113 (37.2 %) prognathic mandible). Concerning the maxilla, 92 (30.2%) individuals presented an orthognathic upper jaw, whereas 60 (19.7%) showed maxillary retrognathism and 153 (50.2%) maxillary prognathism. Compared to patients with skeletal class I, skeletal class III individuals presented significantly more hypertrophic posterior clinoid process (p<0.007) and pyramidal shape of the dorsum of the ST (p<0.038).

Conclusions

Our results suggest that the hypertrophic posterior clinoid process and pyramidal shape of the ST dorsum are more prevalent in individuals with skeletal class III malocclusion.

Knowledge of human anatomy is an important scientific basis for every dentist, and the adequacy of its provision by anatomy faculties is therefore constantly being adapted. Students' motivation to comprehend knowledge is a fundamental prerequisite and has been shown to increase when the relevance of the subject is clear. This study examines dental students' perceptions of the relevance of the anatomy curriculum, with particular reference to clinical practice and the dissection course, in conjunction with the perceptions of surgically specialized dentists. The distinctions between the participating groups concerning their perceived relevance are being discussed particularly regarding their applicability to improve the anatomical education of dental students. The overall aim is to find and highlight aspects of the clinical use of anatomical knowledge towards students, which they are unable to apprehend yet. A questionnaire consisting of information on demographics and professional competence as well as a Likert-style section was administered to dental students at Charité Universitätsmedizin in 2019/2020 (n = 322, 84.96%) and a modified version with congruent questions was administered retrospectively to oral surgeons practicing in Berlin in 2020 (n = 81, 63.3%). A Wilcoxon rank-sum test was used to examine differences in responses between the cohorts. Demographic data and professional competence were correlated with the participants' ratings of the given statements using Spearman's rank correlation coefficient. Both groups of respondents expressed a high level of appreciation of the overall relevance of anatomical knowledge, valued the teaching of all human anatomy for dental education, and recognized the relevance of anatomical knowledge for clinical practice. The importance of the dissection course was also rated relatively high by both groups of respondents. The overall appreciation of anatomical knowledge was more prevalent among oral surgeons. There were few correlations between demographics in our findings, showing slightly higher motivation in female students and a growing appreciation of anatomical knowledge as students qualification progressed. The demographics and post-qualification experience of the participating oral surgeons did not influence their perceptions. The results of this survey suggest that there is potential to increase the motivation of dental students to learn anatomy by emphasizing clinical relevance, as perceived by experienced practitioners, during the anatomy curriculum.

Background

The relevance of anatomical dissection in instructing anatomy to medical, dental, and other health science students is indisputable. Ethiopian anatomists encountered challenges in obtaining human bodies for anatomy education and research, both prior to and following the COVID-19 outbreak. The challenges intensified during the pandemic, significantly affecting anatomy education in Ethiopia. This study seeks to investigate the sources of bodies for anatomy, spanning the periods before and after COVID-19, with a particular focus on identifying the primary challenges associated with sourcing of bodies in Ethiopia.

Methods

Fifty (50) anatomists completed a survey distributed to ten (10) randomly chosen medical institutions in Ethiopia. The survey gathered information on the body profile (number of bodies, age, sex, sources, and methods of body disposal), and the challenges faced during the sourcing of bodies in the years 2018 and 2023.

Results

A total of sixty-three (63) bodies were used by the sampled medical institutions between 2018 and 2023 academic years. All (100%) of the bodies used were unclaimed human bodies. Most (66.7%) of these bodies were males. The majority (65.5%) of these bodies were sourced from Tikur Anbessa hospital in Addis Ababa. None (0%) of the sampled medical institutions had body donation programs. Disposal of human tissues encompassed various methods, including the retention of skeletons, prosection of vital organs, and burial of remaining tissues. Economic constraints and the absence of a legal framework document were the main challenges in acquiring bodies in the pre-pandemic period. The COVID-19 pandemic prevention policies and the civil war further exacerbated the challenges in sourcing of bodies for anatomy dissections during the post-pandemic period.

Conclusion

The reliance on unclaimed human bodies for anatomy education and research in Ethiopian medical institutions mirrors a common practice across many African countries. The authors suggest the development of a legislative framework or operational guidelines, coupled with empowering the medical institutions to outsource their own funding that will ultimately lead to an increased number of bodies available for anatomical dissection. Over time, implementation and promotion of body donation programs may also resolve body shortages for anatomy education in Ethiopia.

Background and aim

The cochlear aqueduct (CA) connects between the perilymphatic space of the cochlea and the subarachnoid space in the posterior cranial fossa. The study aimed to examine 1) whether cavitation of the CA occurs on the subarachnoid side or the cochlear side and 2) the growth and/or degeneration of the CA and its concomitant vein.

Methods

We examined paraffin-embedded histological sections from human fetuses: 15 midterm fetuses (crown-rump length or CRL, 39–115 mm) and 12 near-term fetuses (CRL, 225–328 mm).

Results

A linear mesenchymal condensation, i.e., a likely candidate of the CA anlage, was observed without the accompanying vein at 9–10 weeks. The vein appeared until 15 weeks, but it was sometimes distant from the CA. At 10–12 weeks, the subarachnoid space (or the epidural space) near the glossopharyngeal nerve rapidly protruded into the CA anlage and reached the scala tympani, in which cavitation was gradually on-going but without epithelial lining. However, CA cavitation did not to occur in the anlage. At the opening to the scala, the epithelial-like lining of the CA lost its meningeal structure. At near-term, the CA was often narrowed and obliterated.

Conclusion

The CA develops from meningeal tissues when the cavitation of the scala begins. The latter cavitation seemed to reduce tissue stiffness leading, to meningeal protrusion. The so-called anlage of CA might be a phylogenetic remnant of the glossopharyngeal nerve branch. A course of cochlear veins appears to be determined by a rule different from the CA development.

Fish cartilage is known as a valuable source of natural biomaterials due to its unique composition and properties. It contains a variety of bioactive components that contribute to its potential applications in different domains such as tissue engineering. The present work aimed to consider the properties of backbone cartilage from fish with a cartilaginous skeleton, including elasmobranch (reticulate whipray: Himantura uarnak and milk shark: Rhizoprionodon acutus) and sturgeon (beluga: Huso huso). The histomorphometric findings showed that the number of chondrocytes was significantly higher in reticulate whipray and milk shark compared to beluga (p < 0.05). The highest GAGs content was recorded in reticulate whipray cartilage compared to the other two species (p < 0.05). The cartilage from reticulate whipray and beluga showed higher collagen content than milk shark cartilage (p < 0.05), and the immunohistochemical assay for type II collagen (Col II) showed higher amounts of this component in reticulate whipray compared to the other two species. Young’s modulus of the cartilage from reticulate whipray was significantly higher than that of milk shark and beluga (p < 0.05), while no significant difference was recorded between Young’s modulus of the cartilage from milk shark and beluga. The gene expression of ACAN, Col II, and Sox9 showed that the cartilage-ECM from three species was able to induce chondrocyte differentiation from human adipose tissue-derived stem cells (hASCs). From these results, it can be concluded that the cartilage from three species, especially reticulate whipray, enjoys the appropriate biological properties and provides a basis for promoting its applications in the field of cartilage tissue engineering.