Intestinal lymphoid tissue changes in the cortisone-treated Wistar rat.

This paper continues the previous investigation of the Department on the lymphoid tissue of central and peripheral lymphoid organs under different experimental conditions. The morphological reactional modalities of the intestinal lymphoid tissue in the male Wistar rat were followed up under endocrine imbalance conditions following cortisone administration. Seven days after administration cortisone induced a hyperplasia of the intestinal lymphoid tissue in parallel with a depletion of the lymph node parenchyma and a hypercellularity of bone marrow.

Postovariectomy bone marrow changes in irradiated and unirradiated wistar rats.

Bilateral ovariectomy of Wistar rats has per se a stimulative effect on the myeloid tissue, determining a hypercellularity of this organ-tissue. On the other hand, under the conditions of a whole-body irradiation with a single dose of 800 r X-rays, bilateral ovariectomy manifests a protective effect on the myeloid tissue preventing the development of hypoplastic, respectively aplastic modifications.

Postcortisone medullary changes in the irradiated and unirradiated male Wistar rat.

Cortisone administration in male Wistar rat induces a depletion of the granulocytic-normoblastic cell population in the bone marrow in parallel with a numerical increase by accumulation of lymphoid and undifferentiated cells. These changes are more intense under irradiation conditions. The reversibility of medullary modifications is shown by the integrity of the reticulinic skeleton of the bone marrow.

Histological and histochemical study of rat salivary glands during their postnatal development.

The postnatal development of the three major salivary glands (parotid, submaxillary and sublingual) was comparatively followed up from the histological viewpoint and in relation with some histochemical reactions. The sublingual gland presented a well developed cytomorphological structure at birth, whereas the parotid and the submaxillary ones, immature at birth, gradually reached the overall appearance of adult glands, the former at 5--6 weeks, the latter at 8 weeks. In relation with the product secreted, it is already from birth that the parotid and the submaxillary glands presented negative reactions for mucosubstances and positive ones for revealing the protein-bound groups.