Prenatal post-implantation development of collared peccaries (Pecari tajacu Linnaeus, 1758)

Given the importance of information on intrauterine development in diagnosing anomalies in the gestational development of the species for the development of assisted reproduction technologies as well as understanding the autonomy and responsiveness of the newborn, the aim of the present study was to describe the external morphology of collared peccary conceptuses. For this study, two conceptuses were used per gestational age of 25-120 days post-copulation (dpc) and neonates with 145 dpc, totalling 22 animals. Females were euthanised, and embryos/foetuses were examined, measured, and photographed. During the first third of the gestational period (25-50 dpc, n = 8), a marked body curvature, brain vesicles, somites, internal organs, placid lens, auricular protrusion and limb buds are noted. In the second third of the gestational period (51-100 dpc, n = 10), foetuses lose their body curvature, displaying greater anatomical definition, including skeletal, external ears, nostrils, eyelids and tactile hair formation and cranial suture closure. In addition, dorsal scent gland and genital tubercle differentiation were visualized at 50 days post-copulation. In the third of the gestational period (101-145 dpc, n = 4), the organs become completely formed, alongside skin darkening, eyelid opening, dental eruption, dorsal odorous gland development, sexual organ externalization, and fanero attachment development. These data allowed for the construction of a prenatal growth curve, providing comparative anatomy information for ungulates and further contributing towards rational reproductive management and reproductive biotechnologies for this species.

Placental development in the early stages of red-rumped agouti pregnancy (Dasyprocta leporina Linnaeus, 1758)

BACKGROUND

Hystricomorpha rodents display a similar placentation model to humans. The present study was carried out considering the scarcity of information concerning the placental development in agouti.

OBJECTIVE

Describe the microscopy of the placenta, subplacenta and yolk sac of agoutis in early pregnancy and report on the inversion of the yolk sac.

METHODS

Fifteen females between the 14th-32nd day of gestation were used following euthanasia. Gestational buttons were collected, fixed, processed, stained to optical microscopy or immunohistochemistry.

RESULTS

Chorioallantoic placenta (CP) ranged from conical to a half-sphere, as follows: from the 14th to 17th day, the CP displays an inverted "V" shape, predominantly formed by cytotrophoblasts; from 20 to 22 days, formed almost entirely by cytotrophoblasts; at 28 days, a half sphere, with distinct lobes and interlobular area, numerous maternal gaps delimited by syncytiotrophoblasts and trophoblast giant cells; at 32 days, globose and undergoing the maturation process. Subplacenta, located between decidua and CP, initially presents septa consisting of simple columnar epithelium and after 17 days, comprising stratified epithelium. Visceral yolk sac (VYS) is attached to two CP projections between 14 and 17 days, formed by a simple cubic epithelium and inverted. Between 20 and 22 days, the epithelium displays apical villous projections with cytoplasmic vacuoles and a vascularized mesoderm. After the 24th day, the VYS near the placenta is pleated, very vascularized and villous, with decreased villi sizes further away from the placenta.

CONCLUSION

The agouti CP displays similar characteristics to other hystricomorpha, including placenta lobulation, a subplacenta and an inverted vitelline placenta.

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.

Arterial Vascularization of the Base of the Brain in Galea (Galea spixii)

Background: Galea (Galea spixii) are rodents which are especially distributed in the northeastern region of Brazil, and have economic importance as their meat is used as a source of protein by the regional population.  Currently, they have received attention from researchers in studies involving their morphology. Thus, seeking to contribute information that supports their sanitary management in addition to the lack of literature on their nervous system, our objective was to describe the arterial vascularization of the base of the brain in this species, in order to identify the arterial pattern and arterial circuit behavior, as well as possible variations in these vessels.Materials, Methods & Results: Brains were obtained from 20 animals (10 males and 10 females) aged between 11 and 12 months, obtained from the Wild Animal Multiplication Center (CEMAS) of the Federal Rural Semi-Arid University (UFERSA), under the approval of CEUA/UFERSA (case number 23.091.000653/2014-26 and opinion number 15/2014), euthanized according to anesthetic protocol recommended for rodents (resolution number 714/2002 of the CFMV/ UFERSA) and preserved frozen in a freezer for an average period of 30 days. The animals were thawed and a longitudinal incision was performed in the thoracic region to allow exposure of the aortic arch. Next, they were cannulated in the cranial direction and injected with Noprene Latex “650” stained with water-based white or red pigment. The animals were subsequently fixed in 3.7% aqueous formaldehyde solution for 48 h, and soon after the brain skull cap was dissected and removed, which was then analyzed, photographed and sketched. Of the 20 animals evaluated, 100% presented vertebrobasilar system responsible for encephalic irrigation of the rostral and caudal regions, and anastomosis of the left internal carotid artery was found in only one case (female) (5%), irrigating the rostral region of the encephalon together with the vertebro-basilar system. In the most frequently found arrangement, the unpaired main arteries present at the base of the brain included: ventral spinal, basilar, medial branch of the rostrais cerebral arteries, medial rostral inter-hemisphere; and the pairs: vertebral, cerebellar caudal, middle cerebellar, trigeminal, rostral cerebellar, rostral tectal, caudal cerebral, pituitary, internal ophthalmic, middle cerebral, rostral cerebral, lateral olfactory bulb and internal ethmoid. Arterial circuit formation was observed as being geometrically similar to a complete, closed and elongated hexagon in the caudal-rostral direction, bypassing the mammillary body, the cinereous tuft and the optic chiasm.Discussion: The study of the nervous system, especially on identification of the arteries responsible for supplying the brain is relevant, especially when it comes to a wild species such as in galea considering that little is known about their morphology, and also because it can be used as a model in clinical and surgical studies related to the nervous system. Based on the analyzed animals, we conclude that the arterial vascularization of the base of the brain in galea is type III, similar to the findings in other species of rodents such as in otters and porcupines; and differing from those described for agoutis and mice-moles. The arterial circuit of galea is complete and closed like those described for the agouti and the European beaver, yet differing from that observed for otters and chinchillas which have an open circuit.

ORIGEM E DISTRIBUIÇÃO DA ARTÉRIA CELÍACA EM PREÁS (Galea spixii Wagler, 1831)

Resumo Para o estudo foram utilizados 20 animais, que estavam em freezer no Centro de Multiplicação de Animais Silvestres (CEMAS/UFERSA). Os animais foram descongelados, a cavidade abdominal aberta e a aorta torácica canulada no sentido caudal para injeção de solução de látex Neoprene 650 corado de vermelho e, em seguida, fixados em solução de formaldeído a 10%, por um período mínimo de 48 horas, para que pudessem ser dissecados, fotografados e os resultados analisados. A artéria celíaca originou-se da aorta abdominal e emitiu as artérias gástrica esquerda, lienal e esplênica. A artéria gástrica esquerda emitiu de dois a três ramos à região da curvatura menor do estômago. A artéria lienal emitiu quatro ramos ao parênquima do baço, de seis a doze ramos pancreáticos e a artéria gastroepiplóica esquerda. A artéria hepática emitiu de um a dois ramos pancreáticos e bifurcou-se em um curto tronco formado pelas artérias gástrica direita e hepática própria e ainda na artéria gastroduodenal, que originava a pancreaticoduodenal cranial e gastroepiplóica direita. O comportamento de trifurcação da artéria celíaca do preá assemelha-se ao encontrado em roedores, como o nutria, a cutia, o hamster e os ratos, o que sugere que este seja o padrão para a ordem.

Morphometric Alteration of Intestinal Epithelium of Rats (Rattus norvegicus) Submitted to the Technique of Enteropexy

Background: Due to the numerous complications that enteropexy may cause in domestic animals and humans, this study aimed at investigating the microscopic level, the damage generated by this technique in mice, in order to investigate the morphometric changes caused by enteropexy technique in rats.Materials, Methods & Results: Eighteen Wistar rats were submitted to surgical technique of enteropexy. To evaluate intestinal disorders they were euthanized at 30 (Group I), 60 (group II) and 90 (group III) days after the procedure. The animals were perfused with 2.5% glutaraldehyde and 4% paraformaldehyde for the removal of intestinal fragments for analysis in conventional microscopy and scanning electron microscopy. In classical histopathology, group I presented mild lesions with necrosis of the epithelium and infiltration of mononuclear cells. After 60 days, extensive ischemic necrosis area was observed, characterized by the denudation of epithelium cells and cellular debris in the lumen surface and loss of intestinal crypts. After 90 days (group III) lesions were evident and were characterized by strong coagulative necrosis of epithelial cells and intestinal crypts. Under electron microscopy, group I showed early fusion of the adjacent intestinal walls. After 60 days there was adherence of luminal stenosis and intestinal walls. In group III loss of epithelium and substitution of necrotic tissue were identified.Discussion: In the current study it was noticed microscopically that the groups had inflammatory reactions to foreign bodies. It is known that the sutures, independent of manufacture, behave as foreign bodies that induce tissue inflammation of the recipient organism and could harm the scar repair. Among the surgical threads, the nylon type (which was chosen for the current experiment) is indicated in the approach tissues in general and bandages, including cardiovascular, ophthalmic and neurological procedures. This category wire induces minimal inflammation of the receptor tissue. In studies of the histopathological analysis of the tissue reactions produced by the wire implant or nylon thread clamp in rats, it was observed that when the local action of two implants were compared, inflammation showed qualitatively similar responses, although they had different characteristics regarding their course. Inflammation is proportional to the proliferation of fibroblasts and the presence of fibrous tissue around the suture. This quote confirms the analyzed samples, in which, in all postoperative times showed inflammatory process, although at different magnitudes. Surgical research in laboratory animals has expanded in recent decades, mainly due to better anesthetic support, the sophistication of infrastructure, material for perioperative continuous monitoring and an incessant search for species that reproduce human morbid conditions. The main focus of these studies have been improving the knowledge about the pathophysiological mechanisms of disease, undertake therapeutic trials with new drugs, studying biomarkers and evaluate new techniques to be applied prospects in man. The most common sites of occurrence of intestinal are ileocolic intussusception junction and jejunojejunal segment. The enteroplication has been used to reduce the occurrence of intussusception, promoting the adhesion of the adjacent serosa layers of intestinal segments and thereby decreasing intestinal motility, their applicability is reported in humans, dogs and cats. The enteropexy technique causes morphological changes in intestinal epithelium of rats, evidenced in conventional and electron microscopy, progress with the passing of time the procedure.

The morphology of the pineal gland of the yellow-toothed cavy (Galea Spixii Wagler, 1831) and red-rumped agouti (Dasyprocta leporina linnaeus, 1758)

The pineal gland is an endocrine gland found in all mammals. This article describes the morphology of this important gland in two species of Caviideae, namely the yellow-toothed cavy and the red-rumped agouti. Ten adult animals of the two species used in current analysis were retrieved from the Center for the Multiplication of Wild Animals (CEMAS/UFERSA) and euthanized. The glands were removed and photographed in situ and ex situ. They were fixed in a paraformaldehyde solution 4% or glutaraldehyde 2.5% solution and submitted to routine histological techniques respectively for light and scanning electron microscopy. Macroscopically, the pineal gland with its elongated structure may be found between the cerebral hemispheres facing the rostral colliculi. Microscopically, pinealocytes and some glia cells were predominant. Contrastingly, to the cavy's pineal gland, a capsule covered the organ in the agouti, with the emission of incomplete septa to the interior, which divided it into two lobules. Light and scanning electron microscopes failed to show calcareous concretions in the pineal gland. Based on the topography of the cavy's and agouti's pineal gland, it may be classified as supra-callosum and ABC type.

Correlação entre o peso, comprimento e anexos fetais de mocós (Kerodon rupestris Wied, 1820)

Foi avaliada a existência de correlação entre diferentes anexos fetais de mocós e determinada a relação entre peso do feto e peso da placenta, relação entre o peso do feto e comprimento do cordão umbilical e a relação entre o peso do feto e comprimento do feto. Foram utilizados anexos fetais e fetos de três, cinco e seis fêmeas, respectivamente, no terço inicial, médio e final de gestação, obtidas no Centro de Multiplicação de Animais Silvestres (CEMAS-UFERSA). Os dados foram expressos em média ± desvio padrão, bem como valores mínimos e máximos, avaliados pelo programa estatístico GraphPad Prism Versão 6.0. Após análise dos pressupostos paramétricos, os dados foram submetidos aos Testes de Kruskal-Wallis e Mann-Whitney e regressão linear. A relação entre peso do feto e peso da placenta demonstrou expressão y = 33,73 + 16,38x com cálculo do coeficiente de correlação entre peso do feto e o peso da placenta elevado e positivo, evidenciando dependência entre as variáveis (R2 = 0,7251). A relação entre o peso do feto e comprimento do cordão umbilical demonstrou expressão y = 35,64 + 25,64x e a análise de correlação entre as variáveis, positiva (R2 = 0,7201) indicando elevada dependência entre as variáveis. Quanto à relação entre o peso do feto e comprimento do feto, identificou-se uma relação do tipo y = a + bx, cuja expressão definida foi y = 1,26 + 0,41x, com análise de correlação das variáveis apresentando elevada correlação considerando-se o valor de R2 = 0,7890. As variáveis analisadas demonstram uma influência direta no desenvolvimento embrionário e fetal em mocós confirmando a correlação destes com o tamanho do feto.