The use of scaning electron microscopy in postvaccinal evaluation of tracheal epithelium of Coturnix coturnix japonica

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

ULTRASTRUCTURE OF THE GERMINATIVE EPITHELIUM IN A GOAT WITH A 5/15-ROBERTSONIAN TRANSLOCATION

The spermatogenesis of two goats bearing a 5/15 Robertsonian translocation was investigated by electron microscopy. There was no dramatic change in the morphology of the cells of the spermatic line. All cells of the seminiferous epithelium seemed quite normal at the ultrastructural level. However a certain disturbance in the cell localization and some morphological abnormalities involving nuclear structure were seen. Spermatocytes and spermatids normal in appearance were observed, but a great number of cells presented two or more nuclei. These cells were frequently seen to become degenerated during spermatogenesis. We believe that unbalanced spermatocytes degenerate during the process and only some spermatocytes succeed in fertilizing gametes.

ULTRASTRUCTURE OF THE HINNY (EQUUS-ASINUS X EQUUS-CABALLUS) SEMINIFEROUS EPITHELIUM

The gonads and the germinative cells of 3 male hinnies were studied with light and transmission electron microscopy with the aim to observe the development of germ cells and verify the morphological modifications due to the hybridization. The hinny seminiferous epithelium presented Sertoli cells and spermatogonia with normal features and anomalous spermatocytes I. The other cells from the spermatogenic sequence were not seen. Most of the alterations began to occur in the cytes I, which presented nuclear vacuolization and deposits of amorphous material between the carioteca and the nuclear lamina, forming vesicles, or exaggerated chromatin condensation, resulting in pyknosis. In the cytoplasm vacuolization was also observed, besides organelle destruction.The arrest of meiosis due to lock of chromosome homologies leads to germinative cell degeneration and, therefore, the spermatogenesis arrest. This fact causes a profound alteration in the seminiferous epithelium morphology in comparison with the parental species.

Lactose load enhances the growth of the small intestine in rats

The present study was undertaken to elucidate the controversial issue regarding the small intestinal structural adaptation, in lactose fed rats. Three study groups were used. One experimental fed 60% lactose and two controls in which the lactose was substituted for similar amount of starch. One of them was fed ad libitum and another a limited amount of food to match the body weight of lactose group. The weight, length of the intestine and intestinal mucosal DNA and protein were determined at days 2, 5, 10 and 30 of the experiment. As compared to starch fed ad libitum controls, animals fed 60% lactose diet ate similar amount of food, grew at a slower rate and weighed 16,7% less at the end of the experiment. In contrast to retarded gain in body weight, small intestinal mucosa of these animals contained more DNA (22,5%) and protein (37,5%) than that of controls. These changes were paralleled by increase in length (17%) and weight of the intestine (24,2%). Therefore, the results of the present study confirmed the findings that the small intestine increases in size in response to lactose feeding and that this occurs in the abscense of hyperphagia. It was further demonstrated that this increase was due both to mucosal cell hyperplasia and hypertrophy.

Morphologic changes in the vesical transition epithelium of alcoholic rats

Few studies are available about the effect of alcohol on the epithelium of the urinary bladder. In the present investigation we studied the ultrastructure of the vesical transition epithelium of normal rats and of rats submitted to experimental chronic alcoholism. Adult rats were submitted to experimental chronic alcoholism by the ingestion of sugar cane liquor. The vesical epithelium was examined after 60, 120, 180 and 240 days of alcohol treatment by transmission electron microscopy. Surface cells presented nuclear and cytoplasmic changes and marked cellular desquamation. There was an increase in multivesicular bodies and lysosomes suggesting cell degeneration. Mast cell infiltration was observed, possibly related to increased epithelial sensitivity. Intercellular spaces were frequently observed. The transition epithelium of the urinary bladder was found to be sensitive to the action of alcohol, as demonstrated by the changes in the components of the blood-urine barrier, the greater sensitivity to inflammation, the increase in cell desquamation and the greater recycling of the apical membrane and of the fusiform vesicles of surface cells observed in alcoholic rats.

Walker 256 tumour growth causes marked changes of glutamine metabolism in rat small intestine

The effect of Walker 256 tumour growth on the metabolism of glucose and glutamine in the small intestine of rats was examined. Walker 256 tumour has been extensively used as an experimental model to induce cancer cachexia in rats. Walker 256 tumour growth decreased body weight and small intestine weight and length. The activities of glucose-6-phosphate dehydrogenase and phosphate-dependent glutaminase were reduced in the proximal, median and distal portions of the intestine. Glutamine oxidation was reduced in the proximal portion only. The decrease in glutaminase activity was not due to a low synthesis of the protein as indicated by Western blotting analysis. Hexokinase and citrate synthase activities were not changed by the tumour. These findings led us to postulate that tumour growth impairs glutamine metabolism of small intestine but the mechanism involved remains to be elucidated. Copyright (C) 2001 John Wiley Sons, Ltd.

Heterotopic gastrointestinal cyst partially lined with dermoid cyst epithelium

We report a rare heterotopic gastrointestinal cyst located in the right submandibular/submental area with histopathologic features that included portions resembling a dermoid cyst. Some theories of pathogenesis are discussed, and an origin of this lesion in entrapped undifferentiated endodermal cells is suggested.

Activity of the Ovarian Germinal Epithelium in the Freshwater Catfish, Pimelodus maculatus (Teleostei: Ostariophysi: Siluriformes): Germline Cysts, Follicle Formation and Oocyte Development

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Morphological Characterization of the Testicular Cells and Seminiferous Epithelium Cycle in Six Species of Neotropical Bats

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)