Morphohistometric and steroidogenic parameters during testicular and epididymal differentiation in cavy (Galea spixii) fetuses.

Sexual differentiation and steroidogenic mechanisms have an important impact on postnatal gonadal phenotypic development. Thus, establishing the activities that lead to male phenotypic development can provide a better understanding of this process. This study examined the prenatal development of cavies to establish morphological and histometric development patterns and protein and enzyme immunolocalization processes that are responsible for androgen synthesis in the testes and epididymis. Histological and histometric analyses of the diameter of the seminiferous cords and epididymal ducts of male fetuses on Days 25, 30, 40, and 50 were performed, as well as immunohistochemistry of the steroidogenic enzymes 5α-reductase and 17ß-HSD, the androgen receptor, and the anti-Müllerian hormone (AMH). Our findings showed a cellular grouping of gonocytes from Day 30 onward that was characteristic of the seminiferous cord, which was not present in the lumen at any of the studied dates. From Day 50 onward, the differentiation of the three anatomical regions of the epididymis was evident, the head (caput), body (corpus), and tail (cauda), with tissue distinctions. Furthermore, the diameters of the seminiferous cords and epididymal ducts significantly increased with age. On Day 50, the tail showed the greatest diameter of the three regions. The Sertoli and Leydig cells exhibited AMH immunoreactivity at all dates. In addition, the Leydig cells and epididymal epithelial tissue were immunopositive for 5α-reductase, 17ß-HSD, and the androgen receptor; therefore, these factors influenced the development and maintenance of the testis and epididymis during cavy prenatal development.

Digitalização e Impressão Tridimensional de Crânio Canino como Ferramenta Educacional para Estudo Anatômico.

Este trabalho teve como objetivo padronizar a digitalização e impressão 3D de crânios de cães para uso educacional e avaliar a eficácia de modelos anatômicos impressos na disciplina de anatomia do curso de medicina veterinária. Os crânios foram selecionados para escaneamento e criação dos modelos impressos 3D modelados por fusão de deposição (FDM) utilizando acrilonitrila butadieno estireno. Após uma aula teórica sobre anatomia do crânio os modelos impressos 3D e os modelos reais do crânio de cães foram apresentados aos 140 alunos durante a aula prática de ossos. Uma avaliação prática de osteologia foi realizada após um mês que consistiu na identificação de estruturas anatômicas dos ossos do crânio identificados por alfinetes. Os alunos foram divididos em duas turmas para a realização da avaliação; o primeiro grupo fez os testes usando os crânios reais, enquanto o segundo grupo os crânios impressos 3D. O desempenho dos alunos foi avaliado conforme as suas performances no exame prático. No final da disciplina, eles foram convidados a responder a um breve questionário sobre suas experiências individuais. Os resultados do estudo demonstram que as estruturas anatômicas dos crânios impressos 3D eram semelhantes aos crânios reais. Não houve diferença significativa quando se analisou o grau de acertos e erros durante a realização do exame entre aqueles que identificaram as estruturas nos crânios reais ou nos impressos 3D. Conclui-se que é possível construir um acervo dinâmico digital e impresso tridimensional (3D) para estudos da anatomia comparada da espécie canina a partir de crânios reais, e que os crânios 3D podem ser usados como uma excelente ferramenta alternativa ao ensino na anatomia veterinária.

Three-dimensional printing educational anatomical model of the patellar luxation in dogs.

BACKGROUND: Few studies are available for assessing the current situation of 3D printing in veterinary medicine, due to the recent popularization of this technology. This study aimed to simulate a 3D model of the femorotibiopatellar joint of dogs based on the medial patellar luxation. The scanning, editing and printing of the femur, tibia, fibula and patella of a dog from the Laboratory of Anatomy of FMVZ USP were performed. RESULTS: Three femorotibiopatellar joint models were printed: one representing a healthy join without alterations; the second one with the medially deviated tibial tuberosity; and a last one representing the shifted tibial tuberosity and the trochlear sulcus flattened as consequence. The 3D edition consisted of medial rotation of the tibia and tibial tuberosity (22° against the healthy tibia), and the flatten of the medial femoral condyle (0.2 cm) and femoral trochlear groove. After printing, the corresponding measurements were taken with the alterations and the bone models were made with elastics to represent the anatomical components of the dog joint. Finally, the measurements corresponding to the distance from the patellar ligament to the lateral femoral condyle were taken in each specimen, in order to observe the change in position of the ligament according to the occurrence of the bone alterations. CONCLUSION: We printed 3D articular anatomical components of the femurotibiopatellar joint that could be valuable educational tools for the study of medial patellar luxation in dogs.

Canine Skull Digitalization and Three-Dimensional Printing as an Educational Tool for Anatomical Study.

This article aims to standardize 3D scanning and printing of dog skulls for educational use and evaluate the effectiveness of these anatomical printed models for a veterinary anatomy course. Skulls were selected for scanning and creating 3D-printed models through Fused Deposition Modeling using acrylonitrile-butadiene-styrene. After a lecture on skull anatomy, the 3D-printed and real skull models were introduced during the practical bone class to 140 students. A bone anatomy practical test was conducted after a month; it consisted in identifying previously marked anatomical structures of the skull bones. The students were divided into two groups for the exam; the first group of students took the test on the real skulls, whereas the second group of students took the test on 3D-printed skulls. The students' performance was evaluated using similar practical examination questions. At the end of the course, these students were asked to answer a brief questionnaire about their individual experiences. The results showed that the anatomical structures of the 3D-printed skulls were similar to the real skulls. There was no significant difference between the test scores of the students that did their test using the real skulls and those using 3D prints. In conclusion, it was possible to construct a dynamic and printed digital 3D collection for studies of the comparative anatomy of canine skull species from real skulls, suggesting that 3D-digitalized and-printed skulls can be used as tools in veterinary anatomy teaching.

Comparative assessment of anatomical details of thoracic limb bones of a horse to that of models produced via scanning and 3D printing.

BACKGROUND: Three-dimensional (3D) scanning and printing for the production of models is an innovative tool that can be used in veterinary anatomy practical classes. Ease of access to this teaching material can be an important aspect of learning the anatomy of domestic animals. In this study, a scanner was used to capture 3D images and a 3D printer that performs die-cast printing was used to produce skeletal models of the thoracic limb of a horse. METHODS: Bones from a horse were selected for scanning and creation of 3D-printed models. The printer used a filamentous thermoplastic material (acrylonitrile-butadiene-styrene [ABS]) which was deposited together with a support resin. Comparisons of the anatomical characteristics (measurements from the original and printed bone) were analyzed to determine the p-value. RESULTS: Bones from the thoracic limb: scapula, humerus, radius and ulna, carpus and phalanges were used to produce digital and physical models for 3D impressions. Then the anatomical characteristics of the 3D printed models were compared with those of the original bones. The p-value was measured to be 0.9126, indicative of a strong evidence of similarity between the 3D-printed models and specimens. Thus, there was no significant statistical difference between the models and the original anatomical parts. CONCLUSIONS: The anatomical characteristics were successfully identified in the 3D-printed copies, demonstrating that models of animal bones can be reproduced using 3D printing technology for use in veterinary education.

Digital revolution in veterinary anatomy: confection of anatomical models of canine stomach by scanning and three-dimensional printing (3D) / Revolución digital en anatomía veterinaria: confección de modelos anatómicos del estómago canino mediante escaneo e impresión tridimensional (3D)

Three-dimensional (3D) scanning and printing can contribute to the area of Veterinary Anatomy, producing anatomical models that can be used in teaching. The objective of this project was to apply the 3D digitalization and printing to produce models of the canine stomach, and make these models available as an alternative tool of study in the practical classes of veterinary anatomy. The stomachs of dogs were digitized and printed in 3D models. Anatomical aspects were easily identifies in the models as compared with stomach original. The results of this project clearly demonstrated that the digitalization and 3D printing from the dog stomach come to strongly contribute to the teaching of veterinary anatomy, currently playing an important role by producing replicas which present desirable anatomical characteristics from organ.

El escaneo e impresión tridimensional (3D) puede contribuir al área de Anatomía Veterinaria, produciendo modelos anatómicos que pueden usarse en la enseñanza. El objetivo de este proyecto fue aplicar la digitalización e impresión 3D para producir modelos del estómago canino y hacer que estos modelos estén disponibles como una herramienta alternativa de estudio en las clases prácticas de anatomía veterinaria. Los estómagos del perro fueron digitalizados e impresos en modelos 3D. Los aspectos anatómicos se identificaron fácilmente en los modelos en comparación con el estómago original. Los resultados de este proyecto demostraron claramente que la digitalización y la impresión en 3D del estómago del perro contribuyen en gran medida a la enseñanza de la anatomía veterinaria y que actualmente desempeña un papel importante, al producir réplicas que presentan características anatómicas deseables a partir de órganos.

Morphological tools to evaluate the digestory apparatus in rocky cavy (Kerodon rupestris).

This research describes for the first time the complete morphology of the digestive apparatus of rock cavies. Dissection, light microscopy, and scanning electron microscopy were performed. The oral cavity has: the hard palate without palatine wrinkles and the soft palate; the tongue composed by striated musculature, with presence of vallate, foliated, and fungiform papillae with taste buds and filiform papillae with mechanical function; and, 20 teeth of the hypsodonts type. Esophagus, stomach, small intestine (duodenum, jejunum, and ileum), and the large intestine (cecum, colon, and rectum) are found. The anus is present at the end of the alimentary channel. Organs of digestive tube are composed by four tunics: mucosa, submucosa, muscular, and serosa. The duodenum, jejunum and ileum have villi. Jejunum, ileum and cecum present Lieberkühn crypts. The cecum has mucous glands. Colon and rectum are folded and have goblet cells. Anus presents sebaceous glands. As associated glands it is found the liver with six lobes and gallbladder; a lobulated pancreas; and a pair of each major salivary gland (parotid, mandibular, and sublingual). Parotid glands have serous acini and mandibular and sublingual glands have mucous acini. Pancreas has adenomers. The liver has hepatocytes and portal vein, hepatic artery, and bile duct (portal triad), separated by sinusoids. It is concluded that the digestive apparatus of the rock cavy has variations in the dentition, lingual papillae, and acini of the salivary glands when compared to other rodents. Other variations refer to the well-developed cecum characteristic of herbivorous behavior.

Development of urogenital system in the Spix cavy: A model for studies on sexual differentiation.

This study documented, for the first time, the morphological patterns of differentiation of male and female genital organs of Spix cavy (Galea spixii) using histological and ultrastructural analyses, with immuno-localization of steroidogenic enzymes, cytochromes P450 aromatase (P450arom) and 17α-hydroxylase/17, 20-lyase (P450c17), involved in the synthesis of estrogens and androgens respectively throughout fetal sexual development. Undifferentiated gonads of Spix cavy develop into ovaries in females after 25 days of gestation (DG), exhibiting P450arom immunoreactivity. After 25 DG, paramesonephric ducts develop and form oviducts, uterine horns and cranial portion of the vagina. The caudal portion of the vagina originates from the urogenital sinus, and a vaginal closure membrane is present at the end of gestation. Partial channeling of the urethra into the clitoris occurs after 40 DG, but complete channeling never occurs. A preputial meatus emerges near the tip of organ. In males, undifferentiated gonads develop into testes at 25 DG and develop immunoreactivity for P450c17, which is required for androgens synthesis and likely maintenance of mesonephric ducts. Mesonephric ducts develop subsequently, forming the epididymis and ductus deferens. The pelvic urethra develops after 25 DG with channeling into the penis occurring around 30 DG. This is the first morphological study describing the process of sexual differentiation during gestation in a hystricomorph rodent and one of the most comprehensive analyses conducted in any mammal. Male genital organ development follows the general pattern described in other domestic mammals, but does not include formation of the baculum as occurs in mice and rats. In females, clitoral development includes partial canalization by the urethra and development of a preputial meatus. Further studies are required to clarify the mechanisms involved in the differentiative processes described.

Development and morphological changes in the vaginal closure membrane throughout gestation in Galea spixii (Rodentia: Caviidae).

Present research was carried out in order to perform the monitoring of development, recognizes the type of tissue and describes histological and cellular changes of the vaginal closure membrane (VCM) throughout pregnancy in Galea spixii. The results showed that at 20 days of gestation (DG), the VCM occludes completely the external vaginal ostium. Microscopically, the VCM presented juxtaposed cells, derived from the stratum germinative of the stratified epithelium of vaginal mucosa at 20 DG and areas with cell clusters with the presence of intercellular spaces in the final stages of pregnancy (40-50 DG). At 0 DG, the stratified epithelium of vaginal mucosa presented all strata but at 20 DG presented stratified epithelium without the stratum corneum and stratum granular and showed communicant junctions by desmosomes and interdigitations in the cell membrane compound the VCM. Gradually from 40 to 50 DG the stratum germinative became barely perceptible. Many cells showed apoptotic nuclei and emerged many intercellular spacing. So, the interdigitations and desmosomes were not observed. Here, it was demonstrated for the first time that the VCM is formed after the extinction of the stratum granular and corneum of the vaginal mucosa epithelium, with the proliferation of the cells of stratum germinative and communication and junction through desmosomes and interdigitations of these cells. At the end of pregnancy, cellular apoptosis; the spread of stratum germinative; and, absence of cellular communication and junction may be responsible for the weakening of the VCM and may assist the process of rupture of this membrane.

Microscopy of the umbilical cord of rock cavies--Kerodon rupestris Wied, 1820 (Rodenta, Caviidae).

The rock cavies (Kerodon rupestris) are rodents belonging to family Caviidae, with habitat restricted to northeastern Brazil. Current studies have shown that blood cord has stem and hematopoietic cells both with a high regenerative potential, microscopic studies about the description in rodents and other mammals are scarce. The aim of this study was to describe the structural components of the umbilical cord of rock cavies. Rock cavies embryos at different stages of pregnancy were used, three in the first third, five in middle third, and six in the final third of gestation. They were obtained at the Centre for Wild Animals Multiplication of Federal Rural University of Semi-Arid. In rock cavies was observed that the number of vessels involved in the transport of maternal substances was represented by two major arteries, veins and an allantois duct. The umbilical cord was delimited by amniotic epithelium, formed by a layer of squamous cells, connective tissue with characteristic of the mucosal tissue, corresponding to the Wharton jelly (fetal mesenchyme), where elastic fibers were observed and intercellular spaces were arranged in concentric blades. The morphology observed in rock cavies is similar to that described in the literature for other mammals, including man. The rock cavies are well adapted to captivity and are docile, which makes this animal an important model for study within the field of regenerative medicine. The knowledge of the umbilical cord morphology represents a base point for using this animal as a model for culture and cell therapy.

The correlation between age, body weight and testicular parameters in Murrah buffalo bulls raised in Brazil.

Buffalo are an economically important source for meat and milk production, especially in Brazil. However, important aspects of their biology remain unknown thus far. Herein, we describe the reproductive characteristics of male Murrah buffalo (Bubalus bubalis) raised under extensive management conditions by applying biometrics associated with testicular weight. We analyzed seven males, divided into two groups: G1, which consisted of four 18-month-old animals, and G2, which consisted of three 24-month-old animals. Testicular development occurs slowly in Murrah buffalo, suggesting a delay of sexual maturity. The biometric testicular parameters analyzed were scrotal circumference, testicular weight, testicular length, testicular width, testicular thickness and testicular circumference. Our data indicate strong correlations between SC, age and body weight, and additional significant relationships were identified between body weight, age and other testicular parameters. Thus, these parameters are suitable indicators when selecting bulls for breeding purposes.