The toxic effects of cadmium upon the hepatic cells of a freshwater fish were studied. The experiment was developed by the addition of cadmium chloride in the water and histochemical and EM methods were performed. The results showed that acute intoxication induces an increase of lysosomal activity related to the shape, distribution as well as different functional degrees of the organelle condensation. The authors analyze the different situations whose leading alterations of lysosomal behaviour and the probable mechanisms of cadmium action.
Biochemical evidence, based on supra-physiological concentrations of thyrotrophin (TSH), has indicated that this hormone increases the NADP concentration in thyroid follicle cells. The hormone is believed to act both to enhance the reoxidation of the reduced coenzyme and to generate NADP from NAD. The latter effect, mediated by NAD-+-kinase, could be a major control mechanism in thyroid metabolism. In the present study increased sensitivity has been obtained by the use of maintenance culture and of microdensitometry for measuring enzyme activity in the follicle cells. Using low physiological (0.1 muU/ml), and sub-physiological concentrations of the hormone as are used in the cytochemical bioassay systems, it has been shown that the rate of reoxidation of NADPH is enhanced by TSH. Moreover the NAD-+-kinase activity is also greatly increased, and shows a direct relationship to the concentration of the hormone acting on the segments of the gland in vitro. It is possible that this phenomenon could be used to assay TSH. The results indicate that NAD-+-kinase activity may play a significant part in the control of pentose-shunt oxidation in thyroid follicle cells.
-a topographical study was performed in the foot of marine Prosobranchs with subject to analize the mucous glands. Specimens representatives of Archeogastropoda, Meso gastropoda and Neogastropoda were studied. It was found for morphological purposes that glands might be classified in in tra-epithelial and intra-connective. As a new fact it was showed an intra-epithelial glands in Littorina flava and in Cypraea zebra meanwhile Thais haemastoma presents intraconnective glands. INTRODUÇÃO 0 pe dos Prosobranchia e uma massa típica que forma a parte ventral do corpo e se continua dorsalmente com a cabe ça e a massa visceral. É uma estrutura ricamente glandular cuja sola e revestida por células cuneiformes ciliadas, que se alternam com mucocitos (Hyman, 1967).D entre os trabalhos que dão uma idáia da topografia glandular da sola pediosa, destacamos o de Touraine (1952) 0 referido autor, estudando diversas especies de^Prosobran -chia Monotocardios, faz a seguinte descrição genérica das formasglandulares na sola do pé desses moluscos: 1 -Glândula mucosa anterior, presente em todas as espécies por ele estudadas, cujo produto de secreção desemboca na porção anterior do pé. 2 -Epitélio glandular da sola, que se compõe de um epitélio
The normal amount of DNA in human diploid nuclei was determined by the use of the Feulgen reaction measured by microdensitometry. The DNA-content of nuclei in normal human articular cartilage was determined in nuclei of zones 3 and 4 of cartilage of the femoral head removed from osteoporotic fractured necks of femur. Analysis of the results indicated that a degree of synthesis of DNA occurred even in these zones of very elderly persons. Results on these zones in the articular cartilage of osteoarthritic joints indicated that different populations occurred. In some there was DNA-synthesis related to tetraploidy; in others, the DNA was very stable to acid hydrolysis with no sign of biosynthetic activity; in the last group, which contained erosions of the superficial zones, the DNA was unstable to hydrolysis.
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