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Biomedical subjects

A R Smith

Publications and source records attributed to A R Smith.

At least 199 records · Page 11Linked to original sources
PubMed1975

Effect of gonadotropic hormones on the rat pineal gland A fluorescence histochemical and biochemical study.

Changes in the number of autofluorescent and serotonin-containing pinealocytes have been studied after gonadotropic hormone administration using fluorescence histochemistry. Moreover, the 5-HT levels in the pineal gland were determined biochemically under the same experimental conditions. The results suggests that pineal 5-HT levels are not influenced by increased gonadotropin levels, while the amount of autofluorescent pinealocytes increases after gonadotropin injections. It has been postulated that differences in androgenic hormone levels could not cause the changes in the number of autofluorescent pinealocytes. The reaction of the pineal gland to increased gonadotropin levels seemed important in view of the regulatory function of the epiphysis on the hypothalamo-hypophyseo-gonadal axis.

Animals↗
PubMed1975

The pineal gland of the mole (Talpa europaea L.). II. Ultrastructural variations observed in the pinealocytes during different parts of the sexual cycle.

Changes of some ultrastructural parameters (paracrystalline structures, Golgi apparatus, secretory granules) in mole pinealocytes were quantitatively studied during the various phases of the sexual cycle. An increase in quantity of paracrystalline structures and of the Golgi appratuses was demonstrated during the period of high sexual activity in male pinealocytes and during oestrus, gestation and lactation in female pinealocytes. Moreover, the appearance of vacuoles in female pinealocytes was observed during pro-oestrus. These results seemto demonstrate close relationship between the endocrine activity of the hypophyseo-gonadal axis and the synthesis of some compounds by the pinealocytes. No increase in the quantity of secretory granules was observed during the various phases of the sexual cycle studied. Key words: pinealocytes, mole, sexual cycle, ultrastructure, paracrystalline structure.

Animals↗
PubMed1975

The response of a human malignant melanoma cell line to high LET radiation.

The response of a human malignant melanoma cell line in vitro to high linear energy transfer radiation was studied utilizing the neutrons produced by the reaction of 16 and 50 MeV deuterons on beryllium. The relative biological effectiveness (RBE) relative to cobalt-60 gamma radiation was determined under conditions of complete oxygenation. The data indicate that the radioresistance ascribed to malignant melanoma in vivo is not an intrinsic quality of the cell but rather may be mediated by the in vivo environment.

Animals↗
PubMed1975

Immunoglobulins in cattle vaccinated with leptospiral bacterins.

The growth-inhibition test was used to detect specific antibodies against Leptospira interrogans serotype hardjo in isolated immunoglobulin (IgG and IgM) fractions of serums from cattle vaccinated with leptospiral bacterins. The growth-inhibiting antibodies were detected mainly in the IgG class. Agglutinated clumps also occurred with the IgM fraction. The serums collected from cattle 4 months after vaccination were negative in the microscopic agglutination test.

Animals↗