Anatomical Science International最新文献

Introduction: Although various vessel-related models using pig hindlimbs have been reported, descriptions of the arterial tree of pig hindlimbs are either rare or confusing. This cadaveric study was designed to explore and describe the anatomy of the arterial tree of pig hindlimbs and to compare with the arterial tree in human legs.

Materials and methods: The vascular anatomy of the hindlimb of lard infused pigs (Shanghai White Pig) was investigated (n = 20). The primary parameters were as follows: the course and branches of the arterial tree of pig hindlimbs; the discrepancy in the anatomical terms of the arterial tree of pig hindlimbs between the classic veterinary books and the literature; the comparison of the arterial tree of pig hindlimbs and the arterial tree in human legs; and the addition of the arterial tree in human legs from the literature.

Results: The internal iliac artery and external iliac artery directly originated from the abdominal aorta without forming a common trunk (the common iliac artery in humans). According to their continuation, the arterial tree of pig hindlimbs was divided into the following segments: external iliac artery, femoral artery, popliteal artery, and cranial tibial artery. The anatomical terms of the arterial tree of pig hindlimbs in the literature exhibit great discrepancies. It was also observed that the arterial tree of pig hindlimbs and the arterial tree in human legs greatly differed. Some studies have reported good additions of the arterial tree of pig hindlimbs.

Conclusions: This study describes the anatomic differences between the arterial tree of pig hindlimbs and the arterial tree in human legs enabling a more consistent nomenclature when using pig studies for clinical use.

Expression of collagen type III and tenascin-C was investigated in developing joints of embryonic chick skull using immunohistochemistry and in situ hybridization. At E8.0, the quadratomandibular joint was formed between the quadrate cartilage and the articular cartilage, with an intervening interzone consisting of fibrous tissues. Collagen type III immunoreactivity and COL3A1 mRNA expression were restricted to the interzone and the surface layer of cartilage. By contrast, tenascin-C expression was detected throughout the peripheral layer of the cartilage, but the expression intensity was reduced in the surface layer within the joint, indicating that both molecules exhibit a distinctive expression pattern. This expression pattern was maintained at E15.0, after formation of the articular space. At E11.0, the quadratosquamosal joint was formed between the quadrate cartilage and squamosal bone, with the perichondrium and periosteum intervening. Collagen type III expression was restricted to the perichondrium within the joint. Meanwhile, tenascin-C expression was detected throughout the perichondrium and peripheral layer of the cartilage, but the expression intensity was reduced within the joint, indicating a distictive expression pattern similar to that of quadratomandibular joint. At E14.0, the pterygoid-parasphenoid joint was formed between the palatoquadrate cartilage and parasphenoid cartilaginous pad, with a narrow interzone. Immunoreactivity indicative of collagen type III and tenascin-C expression was observed throughout the cartilage area, with regional differences in staining intensity, which also suggests a distinctive expression pattern. These results suggest that both collagen type III and tenascin-C may be associated with joint formation in chick skull.

High jugular bulb (HJB) and jugular bulb dehiscence (JBD) are anatomical variants with significant clinical implications; however, reported prevalence varies widely due to heterogeneous definitions and imaging protocols. We conducted a systematic review and meta-analysis of 49 studies, encompassing more than 43,000 temporal bones and 17,000 patients, to estimate pooled HJB and JBD prevalence. Observational studies reporting extractable prevalence data were synthesized using random-effects generalized linear mixed models with cluster-robust variance estimation. HJB definitions were harmonized into landmark-based families (internal acoustic meatus, round window/basal turn, tympanic annulus, tympanic protrusion), and separate analyses were performed for per-patient and per-ear denominators. Pooled HJB prevalence was 24.4% per patient (95% CI 16.7-34.3; prediction interval 3.8-72.4) and 16.2% per ear (10.7-23.8; PI 1.6-69.7), with extreme between-study heterogeneity (I² > 97%). Definition-specific estimates differed systematically, with round-window/basal-turn criteria yielding approximately 22% compared with 15% for internal acoustic meatus-based definitions. JBD prevalence was 6.1% per patient (3.4-9.5) and 3.2% per ear (2.1-4.7). Meta-regression indicated that definition choice accounted for less than 10% of between-study variance, with imaging protocols, measurement planes, and clinical populations accounting for most of the remaining heterogeneity. Both variants are sufficiently common to warrant routine preoperative imaging before otologic and skull-base procedures. Given wide prediction intervals, single pooled prevalence values are not directly transportable; reporting should emphasize definition-specific estimates and imaging parameters to inform surgical planning and risk stratification.

Although previous research has examined the first lumbar (L1) vertebra for sex estimation, studies focusing on its role in age estimation have been limited. This study expands on earlier work by investigating the morphological variations in shape and size of the L1 vertebra across different age groups within the Malaysian population. A sample of 440 abdominal CT images was collected from the Radiology Department at Universiti Kebangsaan Malaysia Medical Centre. These images included adults aged 18 to 80, who visited the department in 2019. Twenty-seven 3D landmarks were marked on each L1 vertebra using digitized 3D CT scan images. Statistical analyses were performed using a geometric morphometric approach to evaluate age-related variations in the shape and size of the L1 vertebra. Principal Component Analysis identified 74 shape variables describing the shape of the L1 vertebra, with the first five principal components explaining 38.27% of the variance. The Canonical Variate Analysis scatter plot showed slight separation among the confidence ellipses for the three age groups, with significant p-values (p < 0.001). Procrustes ANOVA revealed significant differences in both the size and shape of the L1 vertebra across all age groups. Additionally, multivariate regression of shape on continuous age revealed a significant, biologically meaningful pattern (R² = 0.022, p = 0.001). This study shows that the size and shape of the L1 vertebra differ across various age groups. In elderly individuals, the L1 vertebra is characterized by longer spinous processes and shorter, flatter vertebral bodies. Conversely, younger individuals tend to have L1 vertebrae with shorter transverse spinous processes and taller vertebral bodies.

Clavicle fractures are common, with midshaft fractures accounting for approximately 70-80% of cases. Malunion often occurs following conservative treatment, but the microstructural characteristics of the malunited region remain poorly understood. This case report describes a rare instance of clavicular malunion identified in a 85-year-old male cadaver during a gross anatomy dissection course. Both clavicles were analyzed using radiography, micro-computed tomography (micro-CT), and histology to investigate the microstructural alterations associated with the malunion. Radiographically, the right clavicle demonstrated anterior-posterior displacement and approximately 10% shortening compared with the intact side. Micro-CT analysis revealed decreased tissue mineral density, reduced trabecular bone volume, marked cortical thinning, and elevated structural indices, including the trabecular bone pattern factor and structure model index, suggesting a loss of trabecular connectivity and a transition from plate-like to rod-like architecture. Histological examination showed that the cortical bone at the fractured site exhibited a disorganized bone matrix lacking a lamellar structure, while the intact side displayed a well-organized lamellar pattern with regularly aligned osteocyte lacunae. These findings suggest that microstructural disorganization and decreased mineral density may contribute to reduced bone strength in the malunion region. Because high-resolution peripheral quantitative CT (HR-pQCT) cannot assess the clavicle, this cadaveric micro-CT and histological analysis provide valuable insights into the microstructural characteristics of clavicular malunion that are not accessible through conventional clinical imaging.

Double-origin vertebral artery is an uncommon anatomic variation that may complicate both radiologic interpretation and surgical planning. In response to the recent case report by Triantafyllou et al. (2025), this correspondence primarily highlights the potential for diagnostic misinterpretation of this configuration on vascular imaging and proposes practical reporting considerations to reduce clinical error. In addition, the variant is briefly discussed within a broader embryological context of vertebral artery development, emphasizing that commonly cited developmental explanations are not mutually exclusive. Together, these perspectives aim to complement the original report by emphasizing imaging-related pitfalls and situating the anomaly within an accepted developmental framework relevant to spine surgeons, radiologists, and vascular specialists.

Immunohistochemistry for amyloid-β peptide is a valuable method for Alzheimer's disease research. Despite a wide variety of available antibodies against the peptides, the difference of immunohistochemical reactivity is not fully described among them. Immunohistochemical reactivity of amyloid-β antibodies is critical for accurate and reliable evaluation of amyloid-β burden in patients as well as models of Alzheimer's disease. Here, we examined immunohistochemical reactivity of two mouse and one rabbit monoclonal antibodies against the N-terminal region of amyloid-β peptides using two Alzheimer's disease mouse models, App^NL-F and App^NL-G-F. 6E10, 82E1 and D54D2 Aβ antibodies were used. We found significant differences in the　immunohistochemical reactivity in both App^NL-F and App^NL-G-F models. While 6E10 immunoreactivity was mainly localized to amyloid-β plaques, D54D2 and 82E1 antibodies stained much more broadly beyond plaques. Interestingly, the latter two antibodies showed blurred filamentous immunoreactivity beyond plaque cores. Double immunostaining using a tyramide signal amplification method, Fluorochromized Tyramide-Glucose Oxidase, suggested that the differential immunohistochemical outcomes were only partially attributable to their sensitivity. Moreover, heat induced epitope retrieval did not affect the differential immunohistochemical outcomes. Our analysis indicates that outcomes of amyloid-β immunohistochemistry are highly contingent on the antibody used in the study.

The philtrum is a key perioral landmark contributing to facial aesthetics. While sex, age, and ancestry influence philtrum morphology, its relationship with underlying dental structures remains underexplored. This study aimed to classify philtrum morphology, quantify its dimensions in an adult cohort, and examine associations with sex, age, and upper dental measurements. The study cohort consisted of 99 adults of European background (71 females, 28 males). Anthropometric assessment was conducted using digital calipers and standardized frontal photography. Philtrum morphology was classified by two independent observers. Statistical analyses included t-tests, correlations, and multiple regression, with additional predictive modelling using machine learning. Parallel morphology was the most common (55.7%). Philtrum height and width were significantly greater in males than females (p < 0.001). Philtrum width and height showed moderate positive correlations with age. In females, central incisor lengths showed moderate negative correlations with age. Multiple regression identified sex and first premolar width as significant predictors of philtrum width and sex, age, and upper central incisor length as predictors of philtrum height. Machine learning models substantially improved predictive accuracy compared to multiple regression, explaining 72% of the variance in philtrum width and 58% in philtrum height. Inter-observer agreement for morphological classification was high. These findings indicate that philtrum morphology varies with sex and age and is associated with underlying dental structures. The study contributes to understanding soft tissue-hard tissue relationships and provides reference data with relevance to aesthetic, orthodontic, and reconstructive contexts.