Anatomia Histologia Embryologia最新文献

The testes of mammals are responsible for gamete production and the secretion of the sex hormone testosterone. Within the seminiferous tubules, spermatogenesis occurs, where germline cells undergo division and differentiation until the formation of spermatozoa. Meanwhile, in the intertubular compartment, Leydig cells produce and secrete testosterone, a hormone essential for spermatogenesis. Monodelphis americana is a marsupial species endemic to Brazil, commonly known as the three-striped short-tailed opossum. The reproductive biology of marsupials remains relatively unexplored despite being a crucial tool for understanding species-specific reproductive strategies, which can aid in management and conservation efforts. In this study, M. americana exhibited a body weight of 36.7 g, with a gonadosomatic index (GSI) of 0.47%, a tubular somatic index (TSI) of 0.36% and an interstitial somatic index (ISI) of 0.27%. The proportion of seminiferous tubules was 83.16%, indicating a significant investment in sperm production. The mitotic and meiotic indices were 1.87 and 2.64 cells per division, respectively, with an overall spermatogenic yield of 12.68. The intertubular compartment accounted for 16.84% of the testicular parenchyma, of which 13.13% consisted of Leydig cells, with a total count of 22.75 × 10⁶ Leydig cells per testis. The findings suggest that M. americana prioritises spermatogenic parameters over the intertubular compartment, implying that males exhibit a promiscuous reproductive behaviour.

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.