Annals of Anatomy-Anatomischer Anzeiger最新文献

Purpose

This study aimed to provide a comprehensive and current overview of the anatomy of the Achilles tendon (AT) twisted structure, as there is a discrepancy in the literature regarding its rotating morphology.

Methods

An extensive literature search was conducted across multiple databases to identify all studies that reported relevant data on the AT torsion, with no date or language restrictions applied. Data was extracted and assessed for this meta-analysis following the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines. The quality of the included articles was examined using the anatomical quality assessment (AQUA) tool.

Results

Seven articles (n=690 limbs) were pooled into this meta-analysis. The prevalence of Achilles tendon torsion types was as follows: type II was the most common (46.7%, 95% CI: 31.6–60.9%), followed by type I (44.7%, 95% CI: 29.8–59.0%), and least commonly, type III (8.6%, 95% CI: 1.8–18.8%). Additionally, morphometric analysis, utilizing the method described by van Gils et al., revealed a mean Achilles tendon torsion of 46.5° (95% CI: 25.1–67.9°).

Conclusions

This meta-analysis underscores the prominent and variable twist within the Achilles tendon among individuals, emphasizing the inherent diversity in AT morphology. Furthermore, the study highlights the importance of considering torsion angle as a potential factor influencing AT pathologies and biomechanical function.

Background

Anterior displacement of the temporomandibular joint (TMJ) disc is the most typical pathological condition of TMJ disorders. Structures attached to the articular disc may support the disc in various directions and contribute to stabilizing the TMJ. However, the relationship between the articular disc, capsule, and masticatory muscles remains unclear. Therefore, this study aimed to clarify the relationship between the masticatory muscles, related masticatory fascia, articular disc, and capsule.

Methods

We examined 10 halves from adult Japanese cadavers, with five halves macroscopically analyzed and the remaining five histologically analyzed. The TMJ was dissected from the lateral aspect for gross anatomical analysis. For histological analysis, the relationship between the temporal and masseteric fasciae and the articular capsule was observed in the coronal section. Additionally, we evaluated relationships among the disc, capsule, temporal fascia, and masseteric fascia in 10 living and healthy volunteers using magnetic resonance imaging.

Results

The articular disc was attached to the capsule without a clear border. The capsule continued into the masseteric and temporal fasciae. Consequently, the articular disc, capsule, masseteric, and temporal fasciae were considered a single complex.

Conclusions

The single complex of the temporalis, masseter, capsule, masticatory fascia, and disc may antagonize the force in the posterolateral direction through the fascia.

Background

Reasonable postoperative humeroradial and humeroulnar joint spaces maybe an important indicator in biomechanical stability of smart internal fixation surgery for coronoid process basal fractures (CPBF). The aim of this study is to compare elbow articular stresses and elbow-forearm stability under smart internal fixations for the CPBF between normal elbow joint spaces and radius-shortening, and to determine the occult factor of radius-ulna load sharing.

Methods

CT images of 70 volunteers with intact elbow joints were retrospectively collected for accurate three-dimensional reconstruction to measure the longitudinal and transverse joint spaces. Two groups of ten finite element (FE) models were established prospectively between normal joint space and radius-shortening with 2.0 mm, including intact elbow joint and forearm, elbow-forearm with CPBF trauma, anterior or posterior double screws-cancellous bone fixation, mini-plate-cancellous bone fixation. Three sets of physiological loads (compression, valgus, varus) were used for FE intelligent calculation, FE model verification, and biomechanical and motion analysis.

Results

The stress distribution between coronoid process and radial head, compression displacements and valgus angles of elbow-forearm in the three smart fixation models of the normal joint spaces were close to those of corresponding intact elbow model, but were significantly different from those of preoperative CPBF models and fixed radius-shortening models. The maximum stresses of three smart fixation instrument models of normal joint spaces were significantly smaller than those of the corresponding fixed radius-shortening models.

Conclusions

On the basis of the existing trauma of the elbow-forearm system in clinical practice, which is a dominant factor affecting radius-ulna load sharing, the elbow joint longitudinal space has been found to be the occult factor affecting radius-ulna load sharing. The stability and load sharing of radius and ulna after three kinds of smart fixations of the CPBF is not only related to the anatomical and biomechanical stability principles of smart internal fixations, but also closely related to postoperative elbow joint longitudinal space.

Background

Short- or mid-term fasting, full or partial, triggers metabolic response known to have in turn health effects in an organism. At central level, the metabolic stimulus triggered by fasting is known to be perceived firstly by hypothalamic neurons.

In the field of neuroscience, ribosomal protein S6 (S6) phosphorylation is commonly used as a readout of the mammalian target of rapamycin complex 1 signalling activation or as a marker for neuronal activity. The aim of this study is addressed to evaluate whether the phosphorylation of S6 occurs in the central neurons of zebrafish exposed to four (short-term) and seven (mid-term) days of complete fasting.

Methods

Group-housed adult zebrafish were exposed to four and seven days of complete food withdrawal. At the end of the experimental period, Western blotting analyses were carried out to measure the expression levels of the phosphorylated S6 (pS6) by comparing the two experimental conditions versus the control group. The same antibody was then used to identify the distribution pattern of pS6 immunoreactive neurons in the whole brain and in the taste buds.

Results

We did not observe increased pS6 levels expression in the brain of animals exposed to short-term fasting compared to the control, whereas the expression increased in brain homogenates of animals exposed to mid-term fasting. pS6 immunoreactivity was reported in some hypothalamic neurons, as well as in the dorsal area of telencephalon and preoptic area, a neurosecretory region homolog to the mammalian paraventricular nucleus. Remarkably, we observed pS6 immunostaining in the sensory cells of taste buds lining the oral epithelium.

Conclusions

Taken together, our data show that in zebrafish, differently from other fish species, seven days of fasting triggers neuronal activity. Furthermore, the immunostaining on sensory cells of taste buds suggests that metabolic changes may modulate also peripheral sensory cells. This event may have valuable implications when using zebrafish to design metabolic studies involving fasting as well as practical consequences on the animal welfare, in particularly stressful conditions, such as transportation.

Background

The pectoralis minor muscle is located in the anterior thoracic wall. Typically, is constituted by a single belly originating from the 3rd to the 5th rib and inserted into the coracoid process near the origins of the biceps brachii shorth head and of the coracobrachialis muscle. The current study, on human fetuses, aims to detect all morphological muscle variants and to create a new classification system.

Material and methods

Classical dissection of the thoracic wall and the upper limb was bilaterally performed on 25 (13 male and 12 female) human formalin-fixed fetuses aged 18–38 weeks of gestation. The spontaneously aborted fetuses were donated after parental consent to the Medical University anatomy program. The pectoralis minor muscle’s morphology, the number of the muscle’s bellies, their origins, and insertions, as well as the morphometric details of each belly of the pectoralis minor, were assessed.

Results

The pectoralis minor was bilaterally found in all fetuses (50 cases). Three types of muscle were identified based on the number of muscle bellies. In type, I (typical anatomy), were classified the cases with a single belly (in 66%). This type was divided into two subtypes (Ia and Ib). In the subtype Ia, the single belly had a typical course, and in Ib, a proximal attachment was characterized by two small bellies connecting together and creating one muscular mass. In type II, two bellies (24%), and in type III, three bellies (10%) were identified.

Conclusions

Pectoralis minor is morphologically variable in the number of its bellies, its course, its origins, its insertions, and the location of its proximal attachments. The most common type (typical anatomy) was the type I represented by one belly. Other identified variants in the number of bellies by the present study may be hypothetically a result of prematurely terminated embryogenesis.

Background

The use of human bodies for anatomy education and research forms an integral part of the training of health professionals around the world. However, the ethical acquisition of human remains for this purpose has been a challenge in many countries, particularly for those on the African continent. South African institutions have however, been able to progressively transition to a more ethical approach to human body acquisition. The aim of the current study was to investigate the provenance of human bodies and the number used in South African health sciences institutions during the period 2017–2021.

Methods

an online self-administered anonymised questionnaire was circulated to all health sciences institutions in South Africa. Questions were focused on establishing the provenance and the associated number of bodies and body donor programmes.

Results

responses were received from thirteen of the fourteen South African institutions. All thirteen institutions use human bodies for teaching and research, with the majority of the institutions being reliant on bequests (77%) and family donations (62%), and less on unclaimed remains (46%). Most institutions have established body donor programmes. Four institutions were negatively affected by the effects of the pandemic. Memorial services, which continued during the pandemic, were conducted by eight of the thirteen institutions.

Conclusion

South Africa is leading the transition to the ethical acquisition of human remains on the African continent. It is hoped that South African institutions will soon transform to the exclusive sourcing of bodies through willed donation and provide guidance and support for the other countries on the continent.

Background

The perforator flap has garnered significant interest since its inception due to its advantage of not needing a vascular network at the deep fascial level. Perforator flaps are commonly utilized in different flap transplant surgeries, and the thigh flap is presently the most widely used perforator flap. Is it possible for the calf to replace the thigh as a more suitable site for harvesting materials? Currently, there is a lack of relevant anatomical research. This study aims to address this question from an anatomical and imaging perspective.

Methods

This study used cadavers to observe the branches and courses of perforators on the calf and the distribution of skin branches using microdissection techniques, digital X-ray photography, and micro-computed tomography techniques.

Results

The perforators had three main branches: the vertical cutaneous branch, the oblique cutaneous branch, and the superficial fascial branch. The superficial fascial branch traveled in the superficial fascia and connected with the nearby perforators. The vertical and oblique cutaneous branches entered the subdermal layer and connected with each other to create the subdermal vascular network.

Conclusions

We observed an intact calf cutaneous branch chain between the cutaneous nerve and the perforator of the infrapopliteal main artery at the superficial vein site. Utilizing this anatomical structure, the calfskin branch has the potential to serve as a substitute for thigh skin flap transplantation and may be applied to perforator flap transplantation in more locations.

Background

Oxidative stress plays a crucial role in the pathogenesis of many skeletal diseases by inducing osteocyte death. The transcription factor nuclear factor erythroid 2-related factor 2 (Nrf2) is a master regulator of various antioxidant gene expressions through antioxidant response element (ARE) against cellular oxidative stress and can be induced by various stimulants, including the phytochemicals methysticin (MET) and L-sulforaphane (SFN). This study aimed to establish an osteocyte in vitro model to investigate the pharmacological effects of MET and SFN on the Nrf2/ARE pathway.

Methods

MLO-Y4 murine osteocytes and the stably transduced MLO-Y4-SIN-lenti-ARE reporter gene cell line were used. MET and SFN were used as Nrf2 inducers. The cytotoxicity of MET, SFN, and hydrogen peroxide (H₂O₂) was evaluated using the CytoTox-Glo™ Assay. Time- and dose-dependent ARE induction was examined by Monoluciferase Assay. The mRNA and protein expressions of Nrf2 target markers, such as heme-oxygenase 1 (Ho-1), NADPH quinone dehydrogenase 1 (Nqo1), and thioredoxin reductase 1 (Txnrd1), were detected by RT-qPCR, Western Blot, and immunofluorescence staining, respectively. Osteogenesis markers, osteopontin, and osteocalcin were compared with and without treatment by immunofluorescence staining.

Results

The experimental data showed that MET and SFN induced ARE activity in a time- and dose-dependent manner and increased the mRNA and protein expression of antioxidant markers compared to vehicle-treated controls. The protein expression of osteopontin and osteocalcin in the samples treated with SFN were significantly higher than without treatment, and the number of cell death treated with SFN was significantly lower than without treatment under H₂O₂-induced stress conditions.

Conclusions

Nrf2 inducers MET and SFN increased the mRNA expression of antioxidant genes through the Nrf2/ARE pathway in osteocytes. Notably, SFN increased the protein expression of osteocyte-associated osteogenic markers and suppressed cell death under H₂O₂-induced stress condition. Thus, Nrf2 stimulators can exert stress-relieving and osteogenic effects on osteocytes.

Introduction

The appearance of artificial intelligence language models (AI LMs) in the form of chatbots has gained a lot of popularity worldwide, potentially interfering with different aspects of education, including medical education as well. The present study aims to assess the accuracy and consistency of different AI LMs regarding the histology and embryology knowledge obtained during the 1st year of medical studies.

Methods

Five different chatbots (ChatGPT, Bing AI, Bard AI, Perplexity AI, and ChatSonic) were given two sets of multiple-choice questions (MCQs). AI LMs test results were compared to the same test results obtained from 1st year medical students. Chatbots were instructed to use revised Bloom’s taxonomy when classifying questions depending on hierarchical cognitive domains. Simultaneously, two histology teachers independently rated the questions applying the same criteria, followed by the comparison between chatbots’ and teachers’ question classification. The consistency of chatbots’ answers was explored by giving the chatbots the same tests two months apart.

Results

AI LMs successfully and correctly solved MCQs regarding histology and embryology material. All five chatbots showed better results than the 1st year medical students on both histology and embryology tests. Chatbots showed poor results when asked to classify the questions according to revised Bloom’s cognitive taxonomy compared to teachers. There was an inverse correlation between the difficulty of questions and their correct classification by the chatbots. Retesting the chatbots after two months showed a lack of consistency concerning both MCQs answers and question classification according to revised Bloom’s taxonomy learning stage.

Conclusion

Despite the ability of certain chatbots to provide correct answers to the majority of diverse and heterogeneous questions, a lack of consistency in answers over time warrants their careful use as a medical education tool.