Ovarian dysgerminoma causing multifocal metastases in young bitch / Disgerminoma ovariano causando metástases multifocais em cadela jovem

The ovarian neoplasias are unusual in canine species, mainly originated from germinative cells. Among these, dysgerminoma is a rare neoplasm in bitches, predominantly affecting senile and small and medium breeds. They are large, rounded, smooth surface, painless and firm in consistency. The clinical signs commonly demonstrated by patients with this neoplasia are abdominal distension and secondary signs of hyperestrogenism. The diagnosis should be based on the association of history, clinical signs, radiographic, ultrasonographic, cytological, histopathological and immunohistochemical exams. The treatment is the surgical castration and metastases are uncommon. Due to the rarity in bitches, specifically the young animals, this study aimed to describe a case of left ovarian dysgerminoma, of considerable size and adherence in adjacent organs, in a Brazilian Fila, whose showed considerable increase in abdominal volume and progressive weight loss. The diagnosis was confirmed by means of complementary x-ray, ultrasound, histopathological and immunohistochemical tests. Even with the recommended surgical treatment (castration), the patient demonstrated severe respiratory symptoms and increased abdominal volume after two months, and the complementary exams suggested pulmonary and multifocal metastases and the tutor chose euthanasia. As presented by the results, although rare in bitches, dysgerminoma should be included in the differential of ovarian neoplasias, including the young ones.

As neoplasias ovarianas são de ocorrência incomum na espécie canina, principalmente as originadas de células germinativas. Dentre estas, o disgerminoma é uma neoplasia rara em cadelas, acometendo predominantemente fêmeas senis e de raças pequenas e médias. Apresentam-se como massas grandes, arredondadas, de superfície lisa, indolores e de consistência firme. Os sinais clínicos comumente demonstrados por pacientes com este tipo neoplásico incluem distensão abdominal e sinais secundários de hiperestrogenismo. O diagnóstico deve ser baseado na associação do histórico, sinais clínicos, exames radiográficos, ultrassonográficos, citológicos, histopatológicos e imunohistoquímicos. O tratamento de escolha é a castração cirúrgica, sendo que as metástases são incomuns. Perante a raridade em cadelas, em específico as jovens, este relato teve como propósito discorrer um caso de disgerminoma ovariano esquerdo, de tamanho considerável e aderência em órgãos adjacentes, em uma Fila Brasileira, cuja sintomatologia incluiu considerável aumento de volume abdominal e emagrecimento progressivo. O diagnóstico foi confirmado por meio de exames complementares de raios-x, ultrassom, histopatológico e imunohistoquímicos. Mesmo com a instituição dotratamento cirúrgico preconizado (castração), a paciente demonstrou grave sintomatologia respiratória e aumento de volume abdominal após dois meses e, como os exames complementares foram sugestivos de metástases pulmonares e multifocais, o tutor optou pela eutanásia. Diante dos resultados, pode-se admitir que apesar de raro em cadelas, o disgerminoma deve ser incluído no diferencial das neoplasias ovarianas, incluindo as jovens.

The quantification of testicular cells during the postnatal development in two Caviomorph rodents: the guinea pig (Cavia porcellus) and the cutia (Dasyprocta agouti)

ABSTRACT The germinative, Sertoli and Leydig cells of two caviomorph rodents (Cavia porcellus and Dasyprocta agouti) were counted as well as the estimation of the total volume of the testis and the total volume of seminiferous tubules and interstitium in prepubertal, pubertal and adult animals. The number of spermatogonia, spermatocytes and spermatids cells increased during the pubertal phase in both rodents, notably the spermatid cells. The spermatocyte and spermatid slightly decreased in the adult of both rodents, but the increment in spermatogonia cells number was seen, mainly in cutias. The number of Sertoli cells increased in pubertal rodents, but in the adult the number reduced. Substantial number of Leydig cells was counted in pubertal and adult guinea pigs. In cutias, the number of Leydig cells increased in pubertal phase and decline in adults. The design-based stereological method has proven to be unbiased and reliable to be applied in reproduction studies.

Maintenance of the corneal epithelium is carried out by germinative cells of its basal stratum and not by presumed stem cells of the limbus

The purpose of this investigation was to analyze the proliferative behavior of rabbit corneal epithelium and establish if any particular region was preferentially involved in epithelial maintenance. [3H]-thymidine was injected intravitreally into both normal eyes and eyes with partially scraped corneal epithelium. Semithin sections of the anterior segment were evaluated by quantitative autoradiography. Segments with active replication (on) and those with no cell division (off) were intermingled in all regions of the tissue, suggesting that the renewal of the epithelial surface of the cornea followed an on/off alternating pattern. In the limbus, heavy labeling of the outermost layers was observed, coupled with a few or no labeled nuclei in the basal stratum. This suggests that this region is a site of rapid cell differentiation and does not contain many slow-cycling cells. The conspicuous and protracted labeling of the basal layer of the corneal epithelium suggests that its cells undergo repeated cycles of replication before being sent to the suprabasal strata. This replication model is prone to generate label-retaining cells. Thus, if these are adult stem cells, one must conclude that they reside in the corneal basal layer and not the limbal basal layer. One may also infer that the basal cells of the cornea and not of the limbus are the ones with the main burden of renewing the corneal epithelium. No particular role in this process could be assigned to the cells of the basal layer of the limbal epithelium.