Translational Research in Anatomy最新文献

During a routine dissection of a 99-year-old female cadaver we encountered the presence of bilateral supernumerary muscles in the pectoral region. The muscle originated on the anterior surface of the fourth rib and inserted onto the coracoid process and anterior glenohumeral joint capsule via an aponeurosis and was deduced to be the pectoralis intermedius muscle. The pectoralis minor muscle was found to have originated on ribs 2 to 4 anteriorly and inserted into the coracoid process of the scapuvdla thereby shifting cranially. The pectoralis intermedius muscle has controversial classifications and variable embryological origin theories, thus making it not only a rare muscle to encounter but a difficult one to categorize. The objective of this investigation was to study a rare case of bilateral pectoralis intermedius muscle aberrations and discuss its clinical significance.

Purpose

A real-life experience of the effects of a patulous Eustachian tube (ET) by one of the authors led to a search into this condition. This resulted in the ‘discovery’ of four eponymous anatomical structures related to the ET, the origins of which were not well known. The authors conducted a literature review to provide a historical account of this eponymous quartet as an homage to their contributions to the fields of anatomy and otology.

Methods

Applying ‘patulous Eustachian tube’ as the search criterium yielded a total of 258 articles on PubMed search, and 1930 on Google Scholar on September 19th, 2023. During this process, the search criterium was subsequently narrowed to the names of four physicians who were found to have an eponymous relationship to structures of the Eustachian tube: Ostmann, Rüdinger, Von Tröltsch and Weber-Liel. These researchers were individually investigated with consideration given to different variations in spelling. The findings were tabulated and are narrated in the discussion.

Results

Four eponymous anatomical structures closely related to the ET, being Ostmann fat pad, Rüdinger safety space/canal, Von Tröltsch fascia and Weber-Liel fascia were found. Ostmann fat pad was referenced most frequently. Although easily recognizable on histological slides, it is rarely mentioned in textbooks. Von Tröltsch, more popularly known for his various contributions to otolaryngology, lends his name to the salpingopharyngeal fascia. Weber-Liel is linked to the lateral fascia of the tensor veli palatini muscle. All four researchers were German physicians with a special interest in otology. The work of these individuals is presented as a snapshot of a remarkable time during the latter part of the nineteenth century.

Conclusion

Though the Eustachian tube has been discussed for centuries, four remarkable researchers contributed to the general knowledge of this structure during the nineteenth century. Paul Ostmann's fat pad of the Eustachian tube is the most referenced of the four, with little mention of Nikolaus Rüdinger's safety canal in the literature. Anton Von Tröltsch's salpingopharyngeal fascia and Friedrich Eugen Weber-Liel's fascia found between the medial pterygoid and tensor veli palatini muscles are eponymously linked without clear indication of the origin of these connections being found in the literature. The contribution of these physicians, however, extends beyond their work on the Eustachian tube and includes the creation of tools and the establishment of journals specific to furthering the body of work on otolaryngology. Recognition should be given to the names Ostmann, Rüdinger, Von Tröltsch and Weber-Liel for their accomplishments in increasing the knowledge of structures related to the eustachian tube.

Background

During a routine cadaver dissection, findings led to the recognition of Mayer-Rokitansky-Küster-Hauser (MRKH) syndrome. MRKH is the second most common cause of primary amenorrhea in females. MRKH, also known as Müllerian aplasia, is a rare congenital disorder that is seen in 1 out of 5000 karyotypic females (46,XX). Patients with MRKH present with agenesis/aplasia of the uterus and the upper two thirds of the vagina. There are two different subtypes of MRKH. In Type I, only uterovaginal agenesis is seen. However, patients with MRKH Type II have uterovaginal agenesis including the absence of one or both fallopian tubes and ovaries, along with abnormalities of the kidney or skeleton. A subgroup of MRKH Type II is termed MURCS (Müllerian duct aplasia, renal aplasia, and cervicothoracic somite dysplasia) because of the severity of malformations seen in multiple extragenital organs including the kidney and skeleton. A patient with Type II is the rarest of the two subtypes occurring in 28–44 % of MRKH patients when compared to the occurrence of Type I, 56–72 %.

Methods/results

Routine dissection of embalmed 63-year-old Caucasian female cadaver and inspection of various anatomical systems revealed this donor had MRKH type II with MURCS. Herein, reports the anatomical manifestations of MRKH type II with MURCS.

Conclusion

Mayer-Rokitansky-Küster-Hauser syndrome (MRKH) is a rare congenital disorder that is seen in 1 out of 5000 karyotypic females (46, XX). Patients with MRKH present with agenesis/aplasia of the uterus and the upper two thirds of the vagina. The discovery of MRKH in this cadaver was found upon routine dissection. Such findings provide insight into the anatomical implications and organ compensation that can occur over time with this pathology.

Background

This review aims to explore the role of the alveolar antral artery and to contribute a combined data set pertaining to the artery's prevalence, diameter, and proximity of related structures.

Methods

A comprehensive literature review. Five databases were searched, namely: Web of Science, Scopus, MEDLINE-PubMed, EMBASE, CINHAL-Ultimate in September 2023. Collected and analyzed data included the prevalence and diameter of the alveolar antral artery, the diameter of the artery divided into groups of less than 1 mm, 1–2 mm, and more than 2 mm, and the distance between the artery and the alveolar ridge. The AQUA-tool was utilized to assess the quality of each study. The data was extracted and organized into comparison tables.

Results

50 articles met the inclusion criteria. The studies reported differences between genders regarding the included criteria. The review identified inconsistent nomenclature used to describe the alveolar antral artery, potentially leading to confusion or misinterpretation among researchers and clinicians. The literature discusses a variety of scenarios regarding the artery in surgical operations, including techniques for managing and preserving it.

Discussion

The literature highlights the importance of standardizing anatomical nomenclature for anastomosis and emphasizes the necessity for developing clinical guidelines in the management of the artery.

Background

The Gantzer muscle is an anatomical variant muscle that functions in flexion of the volar forearm. The prevalence and laterality of this muscle has been studied more recently in the literature. This study aimed to determine the prevalence and size of this muscle and tendon.

Methods

This was an observational study done from September 2021 to January 2022 at the University of North Texas Health Science Center in Fort Worth, Texas. Cadaveric dissection was conducted in the Department of Physiology and Anatomy. 50 pairs for a total of 100 forearms were dissected bilaterally in cadavers comprising 17 females (34 %) and 33 males (66 %) to identify the Gantzer muscle. The mean age at death was 68.8 years of age (range 40–91 years). When present, the dimensions of each Gantzer tendon were measured in millimeters using digital calipers. As a study of cadaveric specimens, this study was exempt from Institutional Review Board (IRB) approval.

Results

The Gantzer muscle was present in 62 of the 100 forearms (62 %). All 62 Gantzer muscles originated from flexor digitorum superficialis (FDS) (100 %). Of the 62 Gantzer muscles, 42 inserted distally into flexor pollicus longus (FPL) (72.5 %), while the remaining 17 muscles inserted distally into flexor digitorum profundus (FDP) (27.5 %). The tendons inserting into FDP had an average length of 65.495 mm, while those inserting into FPL had an average length of 16.353 mm (p = 0.002). The Gantzer muscle was present in 24 of the 33 male specimens (72.7 %) and 13 of the 17 female specimens (76.4 %). Of the 62 Gantzer muscles, 50 were present bilaterally (80.6 %), and there was no significant difference in bilateral occurrence between sexes (p = 0.189).

Conclusions

Our results suggest that the Gantzer muscle may be of sufficient size and present commonly enough in the general population to be considered as an alternative graft source for certain upper extremity reconstruction procedures in place of, or in addition to, palmaris longus, extensor toe tendons, and other commonly used tendon grafts. In this study, when palmaris longus was absent in a specimen, a Gantzer muscle was likely present, and may provide surgeons an alternative tendon graft source in the upper extremity without requiring additional incisions in the lower extremity for alternative tendon graft sources. Further biomechanical testing of the Gantzer tendon with comparisons to other common tendon graft sources is warranted.

In this study, complete Sacral Spina Bifida Occulta (SSBO) and Lumbosacral Transitional Vertebrae (LSTV) with their various subtypes based on the Castellvi classification were appraised in a South African population sample. Adult human skeletons representing the three largest South African population groups, namely South African African, South African of Mixed Ancestry; South African of European descent; both biological sexes; and age range between 21 and 90 years at death were evaluated for both spinal anomalies.

The number of preselected skeletons (n = 1798) from the largest collection in Africa of modern human skeletons (N = 2630) provided a strong representative South African sample. The observational study looked at lumbar and sacral vertebrae in each skeleton and any anomalous features were captured in an Excel spreadsheet.

Complete SSBO with no LSTV was observed in eight subjects (8/1798; 0.44 %), while incomplete SSBO was observed in one subject (1/1798; 0.06 %), and one individual (1/1798; 0.06 %) exhibiting complete SSBO with LSTV (Type IIIB, Castellvi classification). No significant differences were observed when comparing the prevalence of the LSTV with SSBO in the male and female groups of the different population affinity groups. The number of individuals with SSBO was found in more South African Africans than in the other population groups with no significant difference between groups.

This research revealed the simultaneous presence of two morphological anomalies (SSBO and LSTV) at the same vertebral segment that could result in low back pain. Variant morphology awareness is crucial for clinicians across all modalities to prevent misdiagnosis, leading to better treatment plans, and avoiding injury.

Introduction

The corpus callosum, a principal commissural fibre-bundle of the brain, connects the two cerebral hemispheres, facilitating interhemispheric communication, cognitive and emotional processes. The anatomical definition of the isthmus of the corpus callosum remains unclear in literature with limited studies focusing on this region. This research addresses this gap by providing a detailed anatomical description of the isthmus of the corpus callosum in a South African cadaveric sample.

Methods

Digital photographs of thirty embalmed cadaver brains were analysed and measurements of the corpus callosum and isthmus were taken, as seen on a midsagittal section.

Results

The results revealed no significant differences in isthmus measurements when comparing the sex of the cadavers. The average length of the isthmus accounted for approximately 16.66 % of the total length of the corpus callosum. The isthmus constituted approximately 17.92 % of the corpus callosum surface area. Females tend to have a larger isthmus relative to the size of their corpus callosum. The prevalence of a posterior notch on the superior border of the corpus callosum was found to be approximately 46.66 % in the studied sample, with males showing a slightly higher prevalence.

Conclusion

Since the isthmus constituted almost 20 % of the total surface area of the corpus callosum, as seen on midsagittal sections, it should be acknowledged as a fifth part. It should further be included in the undergraduate neuroanatomy curriculum and textbooks, which is currently lacking this information. This research recommends expanding the sample size, encompassing diverse demographics, employing fresh cadavers, and utilize three-dimensional imaging to understand the isthmus of the corpus callosum and its relevance to neuropsychiatric conditions and brain morphology.

Background

Sex and/or ancestry estimations based on skeletal elements are vital in forensics, as these variables are key to identification of unknown skeletal remains. Unfortunately, patterns of skeletal variation are often shared between sex and ancestry groups, making independent estimation of such variables less accurate, especially when substantial size differences exist both within and between groups. Geometric morphometric analysis allows isolation of the size component of variation, enabling independent and more sensitive detection of shape variation between groups. This creates the potential for more accurate estimations of sex and ancestry either independently or simultaneously, thus reducing the chances of compounding errors of estimation. This would be especially beneficial in heterogeneous populations, such as that of South Africa, where group separation may be affected by complicated genetic and environmental influences.

Methods

This study assessed sex and ancestry variation in morphology of 1894 ulnae of South African males and females of the country's three largest ancestry groups. Three-dimensional data was submitted to Generalized Procrustes Analysis for superimposition and scaling to a common centroid size. Mean centroid sizes and shapes were compared, and accuracy of sex, ancestry, or sex-ancestry estimation was assessed using Discriminant Function Analysis and leave-one-out cross-validation. Covariation with size, age and year-of-birth were assessed through regression analysis.

Results

Male ulnae were absolutely and proportionally larger than female ulnae, while Black individuals were similarly larger than Colored and White individuals. Based on this variation, sex could be estimated with 68.8 % accuracy, and ancestry with 73.6 % accuracy. Simultaneous sex-ancestry assessment showed similar morphological patterning and yielded a mean classification accuracy of 73.6 %.

Conclusions

These results have practical value for forensic application, where relatively poorly elements such as the ulna are often all that is available for analysis. Additionally, simultaneous estimation of sex and ancestry reduces compounding errors that may arise from first estimating one variable and basing the rest of the biological profile estimations thereon. Such improved estimations are of great potential value, especially in heterogeneous populations such as that of South Africa.

The development of the cardiovascular system is a highly intricate process that encompasses various types of cells and communication pathways. During embryonic development, specific cells differentiate and organize to form complex structures of the heart and blood vessels. An important group of cells involved in this process is called cardiac neural crest cells. These cells originate from the dorsal neural tube and migrate to the circumpharyngeal ridge, pharyngeal arches 3–6, and invade the developing heart through the cardiac outflow tract. Once they reach their destination, cardiac neural crest cells contribute to the formation of important structures in the cardiovascular system. These structures include the aortic arch arteries, the aorticopulmonary septum, cardiac valves, the heart conduction system, cardiomyocytes, and smooth muscle cells found in the middle layers of the aortic arch arteries. Disruptions in the migration, proliferation, or differentiation of cardiac neural crest cells during embryonic development, as seen in conditions such as DiGeorge syndrome, can lead to a variety of congenital heart defects. These defects encompass a wide range of abnormalities, including Tetralogy of Fallot, outflow tract abnormalities, persistent truncus arteriosus, double outlet right ventricle, interrupted aortic arch, ventricular septal defects, abnormalities of the aortic arch, as well as abnormalities in the function of semilunar valves, myocardium, and cardiac conduction system.

Background

Since the appearance of Vesalius's treatises, anatomical illustration has eluded unified conventions and strictly defined timeframes, resulting from the individual struggles of scholars and collaborating artists. Until the 19th century, diverse styles characterized anatomical illustrations, and the conventions in which they were created depended on both by cultural conditions and the state of knowledge about the structure of the human body.

Aim

This paper presents selected illustrated anatomical sources published in the early 19th century.

Conclusions

In early 19th-century anatomical iconography, there was a trend of deepening the importance of scientific illustration as a carrier of information and knowledge. Illustrations from this period are still characterized by various styles, degrees of scientific precision, and the scope of detail presented. However, during this period, attempts were made to faithfully reflect the reality of the dissecting room and the anatomical specimen.