Anatomia Histologia Embryologia最新文献

During the early postnatal period, the liver undergoes significant developmental changes essential for its maturation. Hence, this study investigated postnatal liver development in inbred indigenous rabbits (Oryctolagus cuniculus) using histological and morphometric analyses, focusing on the role of leucine-rich repeat-containing G-protein-coupled receptor 5 (Lgr5)^+ve cells. Fifty clinically healthy rabbits were divided into five postnatal day groups (PND 1, 10, 15, 30 and 40). Liver samples were assessed for changes in capsule thickness, hepatocyte dimensions and non-hepatocyte cell density, while immunohistochemistry detected Lgr5 expression to evaluate stem/progenitor cell activity. Results showed a 2.8-fold reduction in liver capsule thickness, concurrent with hepatocyte and sinusoidal maturation. Haematopoietic activity and lipid droplets decreased with age, with fully organised liver architecture achieved by PND 30 and a mature histological appearance resembling that of adult liver tissue by PND 40. Kupffer cells peaked at PND 30, reflecting early immune functions, while megakaryocyte numbers declined, indicating reduced thrombopoiesis. Lgr5^+ve cells peaked at PND 10, acting as bipotential progenitors that supported hepatocyte and cholangiocyte development during liver maturation. These findings reveal that postnatal liver development involves structural maturation and immune remodelling by PND 40, with transient Lgr5^+ve cell activity playing a dynamic role in hepatic remodelling and biliary system development. This study advances our understanding of liver biology and highlights potential avenues for regenerative therapies targeting liver and biliary diseases.

The green iguana (Iguana iguana) is a neotropical lizard with ecological significance due to its role in seed dispersal. Detailed anatomical studies of the circulatory system of this species remain scarce. The aim of this study was to describe the heart, major blood vessels, and coelomic circulation in this species. Four male and two female cadavers were received from environmental authorities, preserved with soft embalming techniques and injected with latex injection. The sinus venosus, positioned dorsally, lacked internal septa and drained into the right atrium via a bicuspid sinoatrial valve. The ventricular sub chambers—cavum arteriosum, cavum venosum, and cavum pulmonale—demonstrated a spatial distribution distinct from other squamates, with the cavum arteriosum and cavum venosum predominantly occupying the left side of the heart. A muscular crest within the ventricle facilitated additional separation between oxygenated and deoxygenated blood, enhancing circulatory efficiency. The aortic and pulmonary trunk valves were identified as simple bicuspid structures. The right aortic arch originated both carotid trunks. The aorta originated multiple parietal, mesenteric, and renal arteries, exhibiting inter-individual variability. A remarkable vascular plexus at the duodenal bulb was observed, from which the hepatic artery originated. The ventral abdominal vein connected the pelvic region to the hepatic portal system. The absence of lateral abdominal veins supports the recommendation to avoid drug administration in the pelvic limbs and tail to prevent renal or hepatic first-pass effects. These findings provide essential information for clinical applications, including surgical interventions and diagnostic imaging in reptile medicine.

The study aimed to detect the morphological and histological structures and morphometric measurements of foot pads using radiography, dissection, and light and scanning electron microscopy in the Golden Jackal (Canies aureus). For this purpose, one adult male and one adult female Golden Jackal (weighing 11 and 12 kg respectively) were used as animal material. Dissection and radiography methods for the macroscopic structure and histological staining (triple stain) methods for the microscopic structure of the foot pads were used. To determine the size and area of the foot pads, the foot pads were first photographed, and then measurements were made from these pictures via the Fiji program. Macroscopically, in the jackal, it was determined that the foot pads were located on the palmar or plantar surface in the paw and pes; the metacarpal (MCP) and metatarsal pads (MTP) were in a triangle shape, and the basal corners of the metacarpal pad were more prominent than those of the metatarsal pad. II. and V. digital pads in both the paw and pes were separated and ovoid-shaped; III. and IV. digital pads uniting in the proximal were shaped like the letter U, with their arms pointing downwards. In SEM images, it was observed that the corneum layer of the epidermis of the digital pads consisted of multilayered keratinized plates resembling fish scales, that there were occasional round-shaped openings in this layer, that cone-shaped protrusions were evident in this layer of MTC and MTP, and that the dermis layer contained abundant connective tissue bundles.

This study examines the detailed histological architecture of accessory adrenal nodules in 10 male donkeys, employing light microscopy and scanning electron microscopy. The accessory adrenal nodule is situated adjacent to the adrenal gland pole, enclosed in a strong connective tissue capsule that merges with the adrenal gland capsule on one side. The nodule is highly vascularised, and the parenchyma is made up of tissue that looks like adrenal cortical tissue. There is no medullary tissue present. There are four layers in the stroma: the zona glomerulosa, the zona intermedia, the zona fasciculata and the zona reticularis. These layers look like the structure of the adrenal gland. The zona glomerulosa is mostly made up of columnar cells and is close to the capsule. The zona fasciculata, which is the broadest zone, has rows of polyhedral cells that are divided by blood sinuses. The zona reticularis is the innermost zone, and it makes little polyhedral cells. These results provide a significant perspective and enhance our comprehension of the structure of the donkey's accessory adrenal nodule.

This study was conducted to examine glandular histological changes in the uterus of Kyrgyz breed mares during the first 6 months of pregnancy. The study used 53 Kyrgyz breed mares; 43 of these were at different stages of pregnancy, while 10 were non-pregnant mares. Uterine samples obtained at the slaughterhouse were evaluated histomorphometrically; endometrial thickness, gland density, gland epithelial height and gland diameter were measured. In conclusion, it was concluded that in Kyrgyz mares, endometrial thickness, glandular epithelial height and diameter increased as pregnancy progressed, while glandular density decreased and that further research on this topic would be beneficial.

This study describes the anatomical and morphological features of the thoracic limbs of different species of South American cervids, with functional interpretations, serving as a reference for clinical and research purposes through dissections, imaging examinations and osteotechnique. 16 thoracic limbs from eight cervids of the genera Mazama and Subulo were analysed. The general limb anatomy was similar to that described for domestic ungulates, with species specific particularities such as less robust and more delicate bones. The hand skeleton displayed rudimentary distal metacarpal bones, characterising the genera as tele metacarpal deer, which are phylogenetically typical of New World cervids. Radiographic examinations and morphological analyses allowed for the visualisation of anatomical patterns specific to South American cervids.

Understanding the anatomy of alpaca (Vicugna pacos) paranasal sinuses is essential for accurate interpretation of diagnostic imaging and surgical planning, especially given the species' susceptibility to dental disease and associated sinusitis. However, detailed anatomical and volumetric data on alpaca sinuses remain limited. This study aimed to characterise the volumetric properties and anatomical composition of the paranasal sinuses in alpacas using semi-automated segmentation of computed tomography datasets, with the goal of supporting clinical practice in veterinary medicine. Seven adult alpaca heads were scanned using computed tomography, followed by semi-automated segmentation and three-dimensional reconstruction. All specimens displayed the dorsal conchal sinus (sinus conchae dorsalis), middle conchal sinus (sinus conchae mediae), maxillary sinus (sinus maxillaris), frontal sinus (sinus frontalis), and lacrimal sinus (sinus lacrimalis). The sphenoid sinus (sinus sphenoidalis) was present in six out of seven animals. Marked inter-individual anatomical variation was noted, particularly in the frontal sinus and sphenoid sinus. Despite this variability, sinus volumes were generally symmetrical between the left and right sides, with no statistically significant differences. The frontal sinus had the largest mean volume, with values of 13.75 ± 6.70 cm³ on the left and 13.91 ± 7.22 cm³ on the right. Statistical analysis revealed no significant correlations between sinus volume and sex, age, or estimated craniofacial volume. Coefficients of variation exceeded 50% in most sinus compartments, emphasizing substantial individual variability. Three-dimensional models highlighted the complex morphology and spatial variation among specimens. This study provides novel insights into the sinonasal anatomy of alpacas, demonstrating a high degree of individual variation despite general bilateral symmetry. These findings emphasize the need for species-specific anatomical references and can aid in improving diagnostic accuracy and surgical outcomes in clinical settings. The three-dimensional reconstructions offer a valuable educational resource for veterinary professionals.

The transcription of ribosomal genes (rDNA) and precursor rRNA (pre-rRNA) processing are crucial biological processes in ribosome biogenesis. Yet, the specific impact of ribosome biogenesis on the first lineage differentiation during early mouse embryonic development remains unclear. Nucleolar proteinLy-1 antibody reactive clone (LYAR) can accelerate ribosome production, regulating rDNA transcription and pre-rRNA maturation. Our study employed immunofluorescence and quantitative polymerase chain reaction (qPCR) to investigate the presence and localization of LYAR during early mouse embryonic development. The interference fragments and mRNA of LYAR were separately injected into embryos at the pronuclear stage, and the embryo development was statistically analysed. The impact of regulating LYAR expression on the first lineage differentiation was determined by immunofluorescence staining, At the 2-cell stage, regulatory fragments and RFP mRNA were injected into a single blastomere. By immunofluorescence staining to determine the proportion of blastomeres with regulated LYAR expression contributing to the ICM. The influence of interfering with LYAR expression at the pronuclear stage on the overall level of newly synthesised rRNA was detected by EU staining. Finally, qPCR was used to further determine the impact of regulating LYAR expression on rDNA transcription and pre-rRNA processing. The results demonstrate that LYAR is detectable at various stages of preimplantation development. Importantly, as embryonic development progresses, LYAR gradually translocates from the cytoplasm and nucleus into the nucleolus. Knockdown of LYAR during the pronuclear stage results in a reduction in the number of ICM following the first lineage differentiation of embryonic development. Furthermore, modulating the expression of LYAR in individual blastomeres at the 2-cell stage affects their contribution to the ICM, altering the proportion of cells that contribute to the blastocyst. Our study hints a link between ribosome biogenesis and the first lineage differentiation, contributing to a better understanding of the mechanisms underlying mouse embryonic development.