Anatomia Histologia Embryologia最新文献

This study on the origin and distribution of the phrenic nerve to the diaphragm was conducted using 16 collared peccaries (Tayassu tajacu). The phrenic nerves originated from the fourth to the seventh cervical spinal nerves, and in a few specimens, from the fourth to the sixth cervical nerves. A contribution from the cranial pectoral nerve to the phrenic nerve was observed. The phrenic nerve terminated in the costosternal and lumbar branches, and less frequently as the lumbocostal trunk and sternal branch. The lumbar branch innervates the crura of the diaphragm, while the costal branch serves the entire costal region. The sternal branch is distributed to the ventrolateral costal area and the sternal portion of the diaphragm on both the left and right sides. These branches send ramifications to the central tendon and the dorsal and ventral surfaces of the caudal vena cava, and also form homo- and heterolateral connections between the branches.

Kinosternon scorpioides scorpioides is an omnivorous chelonian with a wide geographical distribution, occurring from Mexico to South America, especially in Brazil. While morphological observations of the species have described its oesophagus, little is known about the other organs constituting the tubular digestive tract. Therefore, the objective of this study was to describe the morphological aspects of the tubular portion of the digestive tract of this species. Ten adult specimens were analysed. After fixation in 10% formalin, organ fragments were embedded in paraffin using the routine histological technique. Sections of 5 μm thick were stained with haematoxylin–eosin (HE), Gomori trichrome (GT) and Alcian blue (AB) pH 0.4 and 2.5. The tubular portion of the digestive tract of K. s. scorpioides consisted of the oesophagus, stomach, small intestine (duodenum, jejunum and ileum), large intestine (caecum and colon) and cloaca. The wall of the tubular portion of the digestive tract of K. s. scorpioides was made up of four concentric layers: Mucosa, submucosa, muscularis externa and adventitia or serosa. The morphology of the tubular digestive tract of adult K. s. scorpioides described in this study shows structural patterns appropriate to their omnivorous feeding habits, such as a simple glandular stomach, long intestines, a well-developed caecum and the production of mucosecretions throughout the digestive tract. This study provides insights into the digestive physiology of the species and provides data for comparative analyses.

The rising incidence of obesity underscores the necessity for alternative obesity treatments. Patients commonly prefer medication aiding in weight reduction. Topiramate, an antiepileptic drug, is gaining popularity among obese patients for its weight loss benefits. This study aims to explore Topiramate's impact on the cerebella of obese female rats. In the experiment, 24 female rats (200–250 g) were divided into four groups: non-obese control (NOC), obese control (OC), non-obese topiramate (NOT) and obese topiramate (OT). The non-obese rats were given a standard diet, while the obese rats received a high-fat diet (40% fat). After 9 weeks, topiramate was administered intraperitoneally daily for 6 weeks. Following this, the rats were euthanised, and their cerebella were removed. The volume of the cerebellum and mean numerical density of the molecular neurons, granular neurons and Purkinje cells were estimated using stereological methods, and the link between obesity-caused cerebellum damage and TNF-α was assessed through immunohistochemical and bioinformatic techniques. Additionally, histopathological evaluations of the tissues were conducted. The cerebellar volume in the OC group was decreased compared to the NOC group. The topiramate groups exhibited a decrease in molecular or/and granular neuron numbers in the NOT and OT groups. Notably, neurons with dark cytoplasm were observed in the topiramate-treated groups, alongside neuronal degeneration was seen in the obese groups. The connection between TNF-α and obesity or obesity-caused cerebellum damage was confirmed through both immunohistochemical and bioinformatics analyses. These findings suggest that topiramate might have a degenerative effect on the cerebellum, especially following obesity.

This study aimed to identify and analyse the distribution and functional activity of the main types of immunocompetent cells and to assess the level of cell proliferation in lymph nodes and spleen, as well as to identify species-specific differences in the immune system. The main results of the study detailed how T-lymphocytes, B-lymphocytes and macrophages organise and function in the lymph nodes and spleen, identifying specialised zones for cell-mediated and humoral immune response. A high concentration of T-lymphocytes was found in the paracortical (T-dependent) zone of lymph nodes, whereas B-lymphocytes were predominantly localised in lymphoid follicles (B-dependent zone), highlighting the specific organisation of immune defence. The spleen, which provides both humoral and cell-mediated immune response, showed the presence of periarteriolar lymphoid sheaths rich in T-lymphocytes (T-dependent zone) and lymphoid follicles with a high concentration of B-lymphocytes (B-dependent zone). In addition, the presence of macrophages, which play a key role in phagocytosis and antigen presentation, was confirmed in both organs. Immunohistochemical analysis revealed active proliferation of immunoblasts in response to immune challenges, indicating the dynamic nature of the immune response. These data emphasise the complexity and efficiency of the immune system of the studied species, providing their protection against infectious agents and maintaining their health, which is key for the development of new approaches to improve animal health and productivity.

Geometric morphometric studies often rely on accurate landmark placement to analyse shape and size variations. Manual and automated landmarking methods are widely used, but their performance can vary depending on the anatomical structure and complexity. This study compares manual and automated landmarking accuracy in two anatomical samples: the skull and the distal phalanx. Fifteen Holstein cattle skulls and 15 distal phalanges were analysed. Two landmark configurations were used: 10 and 20 landmarks for the skull and 5 and 10 landmarks for the distal phalanx. Both manual and automated landmarking were performed using Slicer software. Procrustes distance and centroid size were calculated to assess shape and size differences. ANOVA was applied to evaluate statistical differences, and PCA was conducted to visualise shape variations. Procrustes distance revealed significant differences between manual and automated landmarking for most configurations, particularly in the skull, highlighting the variability introduced by automated methods. No significant differences were observed for centroid size, indicating consistency in size measurements. Automated landmarking showed increased variability in capturing shape, especially in complex structures and higher landmark densities. Automated landmarking provides efficiency but introduces significant shape variability, particularly in complex anatomical structures. Our findings highlight the superior accuracy of manual landmarking, particularly for capturing subtle anatomical features and complex structures where automated methods face challenges. Although more time-consuming, manual landmarking minimises variability and preserves crucial morphological details, making it essential for precise analysis, especially in the presence of thresholding artefacts in 3D models. Future research should explore multiple software platforms and refine automated algorithms to improve performance in morphometric analyses.

Tamandua mexicana is a species of the superorder Xenarthra that is found in many regions of Mexico, Peru, Colombia, Ecuador and Venezuela. This species is important because it is a model for comparative studies of the evolutionary anatomy of xenarthrans. However, there are few anatomical studies on which to base these areas, such as the anatomy of the brachial plexus. Several studies use the brachial plexus anatomy for phylogenetic analysis and medical procedures. Thus, this study aimed to describe the origin and distribution of the brachial plexus in T. mexicana. Twelve specimens of T. mexicana fixed in formaldehyde 4% were dissected. The ventral spinal nerves from C5 to T2 originated the brachial plexus. In most cases, C5–C7 formed the cranial trunk, C6–C7 the middle trunk and C8–T1 the caudal trunk. In all specimens, these trunks joined and formed the common trunk, which distally divided into two divisions: dorsal and ventral. The pectoralis cranialis, pectoralis caudalis, thoracicus longus, thoracicus lateralis and thoracodorsalis nerves supplied the extrinsic thoracic limb muscles. The innervation for the intrinsic thoracic limb muscles was supplied by the suprascapularis, subscapulares, axillaris, musculocutaneus, radialis, medianus and ulnaris nerves. The intercostobrachialis, axillaris, radialis, ulnaris, medianus and caudal cutaneous antebrachial nerves innervated the skin of this species. The trunks and divisions were similar comparatively to those reported in other xenarthrans. However, T. mexicana was more similar to sloths. This suggests a phylogenetic trade in their evolution. The origin and distribution of the brachial plexus nerves resembled those of the other Xenarthras, which can assist in medical procedures within the superorder.