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 17β-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, 17β-HSD, and the androgen receptor; therefore, these factors influenced the development and maintenance of the testis and epididymis during cavy prenatal development.

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.

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.

Morphology of the genital organs of the female red-rumped agouti (Dasyprocta leporina, Linnaeus, 1758) during estrous cycle phases and in advanced pregnancy

The study investigated the gross and microscopic anatomy of the genital organs of 20 agoutis at different stages of the estrous cycle and four in the final trimester of pregnancy. Specimens were euthanized and their reproductive organs were fixed in a 4% paraformaldehyde or 2.5% glutaraldehyde solution and submitted to routine histological techniques for light and scanning electron microscopy. In the ovary, during the proestrus phase, we observed developing follicles and corpus luteum (CL) in regression; during estrus, there were Graafian follicles; during metestrus, there was a hemorrhagic corpus, whereas in diestrus, there was a mature CL. The uterus was partially double because the cervix was cranially septate but caudally, the septum disappeared, forming a single ostium that opened into the vagina. Changes occurred along the estrous cycle in the uterine and vaginal epithelia, that is, an increase in the uterine epithelium height accompanied by an increase of thickness of the vaginal epithelium during the follicular phase and a decrease of thickness of both epithelia during the luteal phase. The endometrial lining was composed of a simple cuboidal epithelium to simple columnar epithelium with basal nuclei. The vaginal mucosa consisted of epithelium that varied from nonkeratinized stratified squamous (luteal phase) to keratinized stratified squamous (follicular phase). The clitoris was external to the vagina. It presented two protruding lateral keratinized spicules and a centralized urethra, with no common parts between the urinary and genital tracts. Anatomical and histological changes were observed mainly in the cervix, vagina and spicules of the clitoris during the EC.

Influence of racial crossing on testicular structure and spermatogenesis in sheep Santa Inês and crossbred Santa Inês and Dorper

The study aimed at evaluating the testicular structure and spermatogenesis of Santa Inês and Santa Inês and Dorper crossbred sheep. Sixteen testicles of the animals under study were used, in order to evaluate the volumetric proportion, the diameter of the tubules, the height of seminiferous epithelium, the frequency of stages of the seminiferous epithelium cycle and the spermatogenic yield. The data were submitted to Student-Newman-Keulstestat 5% significance. The tubular diameter was 173.12 ± 29.09 μm and 185.71 ± 29.7 μm, and the height of the seminiferous epithelium was 52.29 ± 9.98 μm and 56.68 ± 11.25 μm, for the crossbred and the Santa Inês, respectively. There was no difference between the testicular compartments and the frequency of the stages of the seminiferous epithelium cycle between the groups. Santa Inês sheep presented a number of 15.36 ± 4.49 spermatocytes in the pre-leptotene/leptotene stage and 27.42 ± 6.65 spermatocytes in the pachytene, whereas the crossbred presented 13.18 ± 5.19 and 23.48 ± 7.80, respectively. The crossbred showed higher meiotic yield (3.98 ± 1.28) and spermatogenesis yield (3.71 ± 1.02). It is concluded there are differences in testicular morphology and spermatogenesis between Santa Inês sheep and crossbred Dorper/Santa Inês, indicating that the crossbreeding between the Santa Inês and Dorper animals allows a gain in the reproductive potential.

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.

Pharmacokinetics of tramadol and o-desmethyltramadol in goats after intravenous and oral administration

The aim of this trial was to implement a method to obtain a tool for analyses of tramadol and the main metabolite, o-desmethyltramadol (M1), in goat's plasma, and to evaluate the pharmacokinetics of these substances following intravenous (i.v.) and oral (p.o.) administration in female goats. The pharmacokinetics of tramadol and M1 were examined following i.v. or p.o. tramadol administration to six female goats (2 mg/kg). Average retention time was 5.13 min for tramadol and 2.42 min for M1. The calculated parameters for half-life, volume of distribution and total body clearance were 0.94+/-0.34 h, 2.48+/-0.58 L/kg and 2.18+/-0.23 L/kg/h following 2 mg/kg tramadol HCl administered intravenously. The systemic availability was 36.9+/-9.1% and half-life 2.67+/-0.54 h following tramadol 2 mg/kg p.o. M1 had a half-life of 2.89+/-0.43 h following i.v. administration of tramadol. Following p.o., M1 was not detectable.

Endocrine disorders in pediatric - onset Langerhans Cell Histiocytosis

Langerhans Cell Histiocytosis (LCH) is a rare disorder with a great variety of clinical manifestations. The purpose of this retrospective study was to evaluate the pattern and the long-term course of clinical, laboratorial and radiological findings in pediatric-onset LCH. We reviewed 46 children with histological diagnosis of LCH. Ten children (22%) showed endocrine disorders. Central diabetes insipidus (DI) was observed in all ten patients; GH deficiency was confirmed in four and hypogonadism in two children. There were no adrenal, prolactin or thyroid axis abnormalities. Obesity was observed in three patients. Eight patients showed soft tissue infiltration and five bone involvement. The MRI showed a lack of posterior pituitary bright spot in all DI patients; infundibular infiltration (II) associated or not with sellar or supra-sellar mass was observed in 4 patients. We conclude that the investigation of LCH, a multi-systemic disease, should include central nervous system images. The presence of II and/or DI should raise the diagnosis of LCH. Complete endocrine evaluation, allowing an early hormone therapy, is required to obtain a better quality of life in children with LCH.