Annals of Anatomy-Anatomischer Anzeiger最新文献

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.

Background

Osteoarthritis (OA) is a chronic and complicated degenerative disorder of joints, including several phenotypes. Type 2 diabetes mellitus (T2DM) is one of the major causes of OA. However, few studies on the mechanical behavior of diabetic cartilages have been conducted.

Methods

This study evaluated the microstructural, compositional, and mechanical properties of healthy and diabetic rat cartilages using scanning electronic microscopy, X-ray energy spectroscopy, histology staining, and microindentation tests.

Results

Our results indicated that the diabetic cartilages had a significantly higher elastic modulus and similar permeability (95%CI: 3.72–8.56 MPa and 3.16×10⁻⁶–1.83×10⁻⁵ mm⁴/N·s) compared to the healthy cartilages (95%CI: 0.741–3.58 MPa and 3.15×10⁻⁶–1.14×10⁻⁵ mm⁴/N·s). Their stress relaxation behaviors were similar regardless of the loading rate except for the stretching parameter under the fast loading. Furthermore, the stress relaxation behaviors of the diabetic cartilages were significantly affected by the loading rate, especially the equilibrium force ratio and time constant. These mechanical outcomes could be attributed to the increase of fibril diameters and calcium aggregation in the cartilage.

Conclusions

This study deepens our understanding of how T2DM might facilitate OA in cartilages, which could contribute to the development of more scientific diagnosis and therapies for patients with diabetes.

The knowledge of bone biology has undergone major advances in recent decades. In bone, resorbing osteoclasts have classically been described as tissue-resident macrophages, however, it is currently known that a new subtype of macrophages, called OsteoMacs, are specialised bone-resident macrophages, which, depending on certain conditions, may play an important role not only in bone homeostasis, but also in promoting pro-anabolic functions or in creating an inflammatory environment. There is growing evidence that these osteal macrophages may influence the development of bone-loss diseases. It is essential to understand the biological bases underlying bone physiological processes to search for new therapeutic targets for bone-loss diseases, such as osteoporosis, rheumatoid arthritis, or even periodontal disease. This narrative review provides an update on the origin, characterisation, and possible roles of osteoMacs in bone biology. Finally, the potential clinical applications of this new cell in bone-loss disorders are discussed.

Introduction

The inferior phrenic artery is a paired artery with a variable origin and course, primarily supplying the diaphragm, but also the suprarenal glands, inferior vena cava, stomach, and oesophagus. The aim of this study is to investigate the origin and course of the inferior phrenic arteries on multidetector computed tomography and angiography.

Materials and methods

The anatomy of the inferior phrenic artery was analysed on 2449 multidetector computed tomography scans. Three-dimensional reconstructions were made of the main variations. Additionally, the course and branching pattern of the inferior phrenic artery were descriptively analysed in a cohort of 28 angiograms.

Results

In 565 (23.1%) cases the inferior phrenic arteries arose as a common trunk and in 1884 (76.9%) cases as individual vessels. The most common origins of a common trunk were the coeliac trunk (n=303; 53.6%) and abdominal aorta (n=255; 45.1%). The most common origins of the right inferior phrenic artery were the coeliac trunk (n=965; 51.2%), abdominal aorta (n=562; 29.8%) and renal arteries (n=214; 11.4%). The most common origins of the left inferior phrenic artery were the coeliac trunk (n=1293; 68.6%) and abdominal aorta (n=403; 21.4%).

Conclusion

The inferior phrenic artery has a very variable anatomy. The most common origins of the inferior phrenic artery are the coeliac trunk and its branches, the abdominal aorta, and the renal arteries.

Background

In adults, the intermediate tendon of digastricus muscle usually runs along the medial or lateral side of the stylohyoideus muscle insertion. To provide a better understanding of the variations, we examined the topographical anatomy of the muscle and tendon in fetuses.

Methods

We examined histological sections from six early-term, 26 mid-term and six near-term fetuses (approximately 8–9, 12–18 weeks and 25–33 weeks).

Results

At early-term, an initial sheath of intermediate tendon of digastricus muscle received the stylohyoideus muscle at the superior aspect. The muscle and tendon was distant from the hyoid. At mid-term, near the insertion to the hyoid greater horn, the stylohyoideus muscle consistently surrounded more than 2/3 of the intermediate tendon circumference. In contrast, we found no near-term specimen in which the stylohyoideus muscle surrounded the intermediate tendon. The multilayered tendon sheath was fully developed until near-term and connected to the body of hyoid by an intermuscular septum between the thyrohyoideus muscle and one or two of suprahyoid muscles. Therefore, the hyoid insertion of the styloglossus muscle was a transient morphology at mid-term.

Conclusion

The stylohyoideus muscle insertion was appeared to move from the tendon sheath to the hyoid greater horn and, until near-term, return to the tendon sheath. A fascia connecting the tendon sheath to the body of hyoid was strengthened by the suprahyoid and infrahyoid muscles. The latter muscles seemed to regulate fixation/relaxation of the intermediate tendon to the hyoid. The stylohyoideus muscle slips sandwiching the intermediate tendon might be a rare morphology.

Background

Human sexual dimorphism is associated with many biological characteristics, including dental variables.

Objectives

To investigate if molars fused roots present sex-associated differences.

Methods

Panoramic radiographs were used to investigate the frequency and distribution of permanent molars fused roots. Only patients with all first and second permanent molars were included. Third molars were not investigated. Any molar with roots fused apical to the usual furcal position were considered molar fused roots. Comparisons between males and females were performed using chi-square or Fisher’s and Mann-Whitney tests and the established alpha was 5% (p<0.05). Sex-differential liability models were also proposed.

Results

A total of 84 males and 86 females were included and 1360 molars were analyzed. Among them, 46 (26.06%) present at least one molar with fused root. Second maxillary molars were the most affected teeth. There was an association between sex and molars with fused roots. Females had a 3.4 higher chance to present fused roots than males (OR=3.4, CI 95% 1.6–6.8; p=0.0008). The female: male ratio of molars with fused roots was 2.5:1. The number of molars with fused roots ranged from 1 to 6 per patient, and the mean number of Females presented more molars with fused roots (mean = 1.01; standard deviation = 1.52) than males (mean = 0.31; standard deviation = 0.85) (p<0.05).

Conclusions

Molar fused root of permanent teeth presents sex-associated differences, in which females are more affected than males. Our results support sex-differential liability models for molars fused roots.