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Biomedical subjects

O Bucher

Publications and source records attributed to O Bucher.

At least 19 recordsLinked to original sources
PubMed1978

Ultrastructural and morphometric aspects of the juxtaglomerular apparatus in the monkey kidney.

The authors describe the ultrastructure of the juxtaglomerular apparatus in five adult male Cebus apella monkeys and communicate morphometric data of the macula densa. In comparison with several species of rodents examined before, the macula cells of the monkey contain many more mitochondria and possess a particularly thick basal membrane. The relative volume of the nuclei is slightly smaller than in rodents. The Goormaghtigh cells of the monkey resemble those of the other animals investigated. The epithelioid (or juxtaglomerular) cells do not contain secretory granules. This observation reminds one of the behavior of the epithelioid cells of guinea pigs.

Animals↗
PubMed1978

[Scanning electron microscopic study of the changes of the luminal surface of rat thyroid epithelial cells following exposure to cold for 6 to 48 hours (author's transl)].

Scanning electron microscopic observations of thyroid follicle cells of rats exposed to 4 degrees C for 6 to 48 hours were found to show an increased number of apical microvilli in comparison to those of controls kept at 22 degrees C. These ultrastructural differences--which were statistically significant 48 hours after start of the experiments--are related to stimulation of thyroid gland activity by exposure to cold.

Animals↗
PubMed1978

[Circadian changes of various enzyme activities in the kidney macula densa of gerbils (Meriones unguiculati)].

Circadian Changes of the Activity of some Enzymes in the Macula densa of the Kidney of Mongolian Gerbilis.--The authors investigated the enzyme histochemical activity of some dehydrogenases in the macula densa of desert rodents killed respectively at 11 a.m. and at 11 p.m. The percentage of macula cells which, in comparison with the non specific distal convolution epithelial cells, showed the same or even enhanced enzyme activities was higher at 11 p. m., i.e. nightly (see Tab. 1).

Animals↗
PubMed1977

Comparison of the activities of some dehydrogenases in the juxtaglomerular complex of kidneys of Wistar rats and desert rats (Meriones unguiculati).

The authors compared the enzyme histochemical activities of some dehydrogenases in the macula densa, the Goormaghtigh cells and the epithelioid (or juxtaglomerular cells in the kidneys of desert rodents (Mongolian Gerbils) with those of the Wistar rats. The macula cells (Table 1), which in the Wistar rats are clearly distinct from the non specific epithelial cells of the distal convolution, show, in the desert rats, noticeable fluctuations. Their enzyme histochemical reactions are often weaker than those of the distal convolution cells, with the exception of the NAD-tetrazolium-reductase activity. The Goormaghtigh cells (Table 2) in the kidneys of the Meriones have a much larger enzymatic spectrum than in the Wistar rats. Here also, we find functional variations in the examined desert species. In the epithelioid cells (Table 3) we observed a somewhat weaker enzymatic activity in the Meriones. These cells contain no secretion granules, this making their diagnosis difficult.

Animals↗
PubMed1977

[Studies of the activity of various dehydrogenases in the desert rat (Meriones unguiculati) nephrons].

Researches about the Activity of some Dehydrogenases in the Nephrons of Desert Rats (Meriones unguiculati).--Our desert rats Meriones unguiculati (Mongolian Gerbils) show--also when held under the same experimental conditions as our other laboratory rodents (Wistar rats and white mice)--a somewhat different enzyme histchemical behaviour of these nephrons. The essential difference in the Meriones is that their distal convolutions display on the whole stronger enzyme activities compared as well with the proximal convolutions of the same kidneys, as with the distal convolutions of Wistar rats.

Animals↗
PubMed1976

Morphometric and enzyme histochemical behaviour of the kidney of young rats before and after unilateral nephrectomy.

Four week old male Wistar rats were unilaterally nephrectomized, and one, two, four, fourteen, and twenty-eight days after the operation the remaining kidneys were removed for morphological examination--including measurement of diameters of the tubules--and for histochemical investigation of enzymatic activities in the nephrons. The following enzymes were examined: succinate DH, lactate DH, alpha-glycerophosphate DH, isocitrate DH, glucose-6-phosphate DH, cytochrome oxidase, adenosine triphosphatase, alkaline and acid phosphatases. In comparison with kidneys of control animals of the same age and sex, the hypertrophy of the remaining kidney was found to be, even in these young rats, entirely due to enlargement of preexisting nephrons. The measurements have indicated that the hypertrophy was most distinct between the second and fourth day after uninephrectomy. Four weeks after the operation the diameters of proximal and distal tubules were about 21% and 18% respectively bigger in the uninephrectomized animals than in the corresponding controls. This increase in size was accompanied by some changes in intensity of enzymatic staining reactions; after an initial diminishment, a graduate increase in activity of almost all the observed tubular enzymes was found; this seems to be the expression of the functional compensation by the remaining kidney.

Adaptation, Physiological↗
PubMed1976

[Modification of the number and structure of certain cytoplasmic components of the renal tubules during compensatory hypertrophy].

In the remaining kidney of unilaterally nephrectomised three to six months old Wistar rats, the measurement of the external and internal diameters indicated an increase in size of both proximal and distal convoluted tubules, although less distinct in the latter. Stereomorphometric measurements of the chondriome and the cytoplasmic inclusions (lysosomes, phagosomes, peroxisomes, etc.) have shown, as compared with similar tests in shamoperated animals, changes in the volumes of these components which can be related to the increase of enzymatic activities reported earlier. However, no obvious changes of the general ultrastructure of the kidneys undergoing hypertrophy could be observed.

Animals↗
PubMed1975

[Enzyme histochemical studies on the macula and Goormaghtigh cells of the guinea pig kidney].

Starting from the ultrastructural differences observed between the juxtaglomerular apparatus of the rat and that--only very rarely analysed--of the guinea pig kidney, the authors supposed that enzymhistochemical differences might also exist. This hypothesis could be confirmed by the results obtained in the Macula densa- and the Goormaghtigh-cells (Tab. 1 and 2). Indeed, in both places the Isocitrate dehydrogenase- and the Malate dehydrogenase-activities are stronger in the guinea pig than in the rat. On the other hand, the Glucose-6-phosphate and the 6-Phosphogluconate dehydrogenases show clearly weaker activities in the guinea pig Macula-cells compared with those of the rat, where these two enzymes give by far the strongest reaction. Metabolic differences might be related to the described diversities of the enzyme equipment.

Animals↗