Anatomia Histologia Embryologia最新文献

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.

Sheep (Ovis aries) are ruminant animals, and a key feature they share with other species in this classification is the structure of the ascending colon, specifically the ansa spiralis (also commonly called the spiral ansa, spiral colon or ansa spiralis coli). In sheep, this structure generally forms a discoid spiral, consisting of two to four centripetal gyri, which transition at the central flexure into two to four centrifugal gyri, but some sheep exhibit deviations from this classic form. Current anatomical textbooks and scientific articles lack detailed descriptions relating to all of these possible variations of ansa spiralis in this species. This study identified and documented all of the deviations and their frequencies. The study was conducted from carcasses collected at a slaughterhouse in Tirana, Albania. In total, 555 large intestines from randomly selected sheep over the age of 6 months were evaluated. No records were kept regarding specific age, sex, breed, or region of origin. Among the 555 large intestines, 52 (9.37%) exhibited different ansa spiralis shapes compared to the classical form. Among these irregularly shaped samples, 12 distinct variations were discovered. This study offers valuable insights into the sheep large intestine morphology and lays the groundwork for further research. Future studies could focus on detailing ansa spiralis vascularization or investigating the relationships between ansa spiralis shape deviations, frequencies and factors such as sex, breed, age, diet and region.

There is increasing pressure on meat producers worldwide due to the need for higher yields and improved meat quality. This is why anabolic androgenic steroids (AAS) have been widely used in most countries, due to their ability to accelerate animal muscle growth. However, out of concern for their side effects, EU states have banned their use and implemented control mechanisms. But they are reaching their limits, and therefore, it is necessary to look for new ways and investigate the mechanism of action of AAS on muscle tissue. This study replicated the administration of banned AAS (testosterone, nandrolone and their combination) and observed their effect on pig muscle. The pig model was purposely chosen for the study, as no such research has been carried out on this species. At the same time, pork is one of the most consumed meats in Europe. It focused on histological changes in muscle structure, specifically the size of muscle fibres and the number of satellite cells per muscle fibre. Furthermore, ultrastructural changes in muscle fibres, the diameter of myofibrils, the number of myofibrils per area, the distance between myofibrils and the size of sarcomeres were examined. The results using the techniques of histology, fluorescent labelling and transmission electron microscopy showed that, after the application of AAS, there is an increase in the diameter of muscle fibres, an increase in the diameter of myofibrils, a decrease in the number of myofibrils per surface area and, in the case of testosterone, an increase in the distance between myofibrils and an increase in the length of sarcomeres. There was also a significant increase in the number of satellite cells per muscle fibre. The detected statistically significant differences between control and experimental groups provide evidence that selected histological parameters could be additional mechanisms for detecting the presence of AAS in pork meat in the future.

South American coati (Nasua nasua) is a carnivoran of the suborder Caniformia and family Procyonidae. Anatomical and functional studies have been performed on the thoracic limb muscles of this species. The topology and innervation are necessary to establish a more suitable anatomical terminology and to infer the muscle evolutionary derivation in anatomical studies. Within the shoulder muscles, the articularis humeri muscle is found caudal to the shoulder joint capsule and is innervated by the axillary nerve. The coracobrachialis muscle is medial and is innervated by the musculocutaneous nerve. However, some studies in N. nasua and other carnivorans describe the coracobrachialis muscle with the name articularis humeri muscle. Therefore, the present study aimed to analyse the terminology and evolutionary derivation inferences of the shoulder intrinsic muscles in N. nasua based on their attachments, topology, and innervation. We dissected 15 thoracic limbs from eight formaldehyde-fixed specimens. Most muscles conserved the evolutionary derivation proposed to other procyonids. Ten limbs presented the articularis humeri muscle similar to that described in the ursid Ursus maritimus (polar bear) and the felids Felis catus (domestic cat) and Panthera leo (lion). This muscle could have derived from the subscapularis muscle and potentially be present in the last common ancestor of carnivorans. Based on most references in myological studies of Carnivora, the present study is the first record of the presence of the articularis humeri muscle in N. nasua. Therefore, the name m. articularis humeri should not be used as a synonym or homologous muscle to the coracobrachialis or coracobrachialis brevis.

Persistent Fourth Right Aortic Arch (PRAA) with retention of the left ductus arteriosus constitutes the most prevalent clinically significant form of vascular ring anomalies in both dogs and cats, accounting for approximately 95% of aortic arch developmental anomalies. This anomaly causes oesophageal compression in weaned animals, leading to restricted passage of solid food, postprandial regurgitation, and potential development of acquired megaoesophagus. Notably, neonatal or lactating animals usually do not exhibit these consequences. While PRAA is well documented in dogs and cats, its occurrence in wild or domesticated ungulates is a rare and intriguing phenomenon, shedding light on congenital cardiovascular anomalies in such species. In this case, a female neonate white-tailed deer, weighing 2 kg, was delivered to the TUERI Wildlife Hospital. Despite receiving substitute feeding and fluid therapy, the specimen faced challenges in milk transit to the abomasum, resulting in postprandial regurgitation. Forelimbs' muscle contractions hindered imaging aimed at elucidating the cause of regurgitation. Nonetheless, these procedures facilitated a presumptive diagnosis of secondary megaoesophagus attributed to a PRAA. The specimen was euthanized, and the carcass underwent necropsy, revealing a PRAA with distinctive anatomical features, including oesophageal dilation, tracheal stenosis, and a constricting vascular ring surrounding both the oesophagus and trachea. This unique case underscores the importance of considering congenital anomalies in wildlife health assessments and contributes to our understanding of cardiovascular anomalies in wildlife species.

This study was conducted on 12 adult pigs of a local mixed breed to examine the histology, histochemistry and ultrastructure of the choroid and retinal pigmented epithelium (RPE). The tissues were fixed in Davidson's Fluid for light microscopy and Karnovsky's fluid for electron microscopy. Due to the physiological, anatomical and metabolic similarities between pigs and humans, pigs are a suitable animal model for various ophthalmic studies. Bruch's membrane exhibited five distinct layers: the basement membrane of the RPE, the inner collagenous layer, the elastic lamina, the outer collagenous layer and the basement membrane of the choriocapillaris. Age-related changes, such as vesicular formation, were also observed. Patches of collagen fibre lamellae were noted in the choroid stroma, indicating the presence of a vestigial tapetum. The apical part of the intercellular space of the RPE cells was completely sealed off by zonula occludens and zonula adherens. Hemidesmosomes were not present at the basal surface of the RPE cells. Numerous melanosomes, lipofuscin, mitochondria, phagolysosomes, melanolysosomal bodies, and both smooth and rough endoplasmic reticulum were observed in the granular cytoplasm of the RPE. Double-membrane-bound round vesicles were also observed in the RPE cytoplasm, characterised by a uniform intermembranous space and a central core space, potentially representing liposome-like structures, although this type of vesicle has not been previously described in the RPE. Overall, the study demonstrated that pigs have a choroid, Bruch's membrane and RPE morphology similar to that of humans, providing a valuable reference for studies using this animal model. Thus, pigs can be utilised as an experimental model for ophthalmic research.

The aim of this study was to determine the embryotoxic and teratogenic effects of doxycycline on chicken embryos. Eggs placed in the incubator were checked with an ovoscope on the 7th day, and a total of 210 fertile chicken eggs were randomly divided into 7 groups. Doxycycline was applied to the experimental groups at 2500, 1250, 625, 312, and 156 μg/50 μL volumes, respectively. Group 6 was evaluated as the Negative Control Group. This group was placed in the incubator again without any treatment. Group 7 was administered 50 μL of 0.9% NaCl solution used as the solvent of the drug. The number of live and dead embryos was determined after the completion of incubation. Mortality was observed depending on the dose, and death was determined in all chicks at the highest dose (2500 μg/50 μL, p < 0.05). No macroscopic anomalies were observed. While a decrease in mortality rates was observed depending on the dose (p < 0.05), the mortality rate in the 156 μg/50 μL dose (Group 5) was similar to the Positive and Negative control groups (p > 0.05). Femur and tibia parameters could not be measured because all embryos in Group 1 (2500 μg/50 μL) died. The length and thickness of the right and left femur and tibia in Group 2 (1250 μg/50 μL) were statistically significantly (p < 0.05) lower than those of the other groups. As a result, it can be stated that doxycycline use should be avoided in pregnant mammals, especially during the development phase of organs, unless necessary.

Three-dimensional structural parameters correlate better with the intestinal function compared to two-dimensional structural parameters. The objective of the present study was to investigate the three-dimensional morphometrical features of the small intestine in rabbits using a design-based stereology. Five adult male New Zealand rabbits were used in this research. The total volume, volume fraction of different layers, internal surface area, villus and circular folds amplification factors were estimated in the whole and various segments of the small intestine. The small intestine volume was estimated to be 59.57 ± 8.57 cm³. The jejunum and ileum showed the most and the least total volumes, respectively (p < 0.05). The volume fractions of the tunica mucosa, tela submucosa and tunica muscularis were 62.57% ± 2.78%, 21.11% ± 2.01% and 16.25% ± 0.94%, respectively. The minimum volume of the tela submucosa was observed in the ileum (p < 0.05) and the fractional volume of the tunica muscularis in the ileum was significantly more than those of other segments (p < 0.05). The surface area of the entire small intestine was estimated to be 8302.31 ± 1872.39 cm². The jejunum and ileum segments showed the most and the least surface areas, respectively. The increase in the intestinal surface area attributable to the presence of villi was estimated to be 6.82 ± 0.84, and that for circular folds was accounted for 1.36 ± 0.09. The largest amplification factors of villi and circular folds were observed in the duodenum and ileum, respectively. Our data presented the three-dimensional morphometry of the small intestine of the rabbit as a translational model and provided basic findings for the diagnosis and treatment of intestinal diseases in this species.