Annals of Anatomy-Anatomischer Anzeiger最新文献

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.

Background

Flaps have become an integral part of plastic and reconstructive surgery. The robust blood supply of such flaps is a prerequisite to reduce flap failure. Despite the reported versatility of the occipital flap, comprehensive anatomical studies on its perforators and perforasomes are lacking. Hence, we examined the perforators originating from the occipital artery and their associated perforasomes, aiming to fill this knowledge gap for reconstructive surgery techniques.

Methods

39 of 40 occipital arteries of 20 fresh anatomical head specimens were dissected. Perforators with a least an outer diameter of 0.50 mm were identified and injected with dye to color their respective perforasomes. Location and size of the colored skin areas were determined as well as the location of their perforators were documented and analyzed.

Results

In total, 183 perforators were found and described. The mean diameter of these vessels was 0.88 ± 0.27 mm (0.5–2.1 mm). The mean area of the perforasomes was 1288.26 ± 662.51 mm² (144.60–3890.60 mm²). They were localized over the whole nuchal and occipital area. Lastly, perforator diameters were significantly associated with the size of their resulting perforasomes.

Conclusion

This study is the first comprehensive overview of perforators and associated perforasomes of the occipital artery on a respectable amount of specimen. The arterial supply of big portions of the occipital and nuchal area is provided solely by the perforators of the occipital artery. For flap surgery, perforator diameter is a crucial detail to be considered in the decision-making process.

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.