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Biomedical subjects

J Ostrowski

Publications and source records attributed to J Ostrowski.

At least 163 records · Page 9Linked to original sources
PubMed1980

Hepatitis B surface antigen and albumin in human hepatocytes. An immunofluorescent and immunoelectron microscopic study.

A close correlation between the presence of hepatitis B surface antigen and albumin in the cytoplasm of hepatocytes infected with hepatitis B virus was established by immunofluorescence and immunoelectron microscopy in 52 liver biopsy specimens of various forms of hepatitis and liver cirrhosis. Albumin deposits usually accompanied cytoplasmic content of hepatitis B surface antigen, but were less frequently observed together with hepatitis B antigen localized in or on the membranes. Ultrastructural observations demonstrated albumin on the tubular and spherical forms of hepatitis B surface antigen in the endoplasmic reticulum. The hepatocytes with the content of hepatitis B surface antigen and albumin showed the ability of binding with the fluorescein-labeled preparation of polymerized human serum albumin. The affinity of polymerized albumin to hepatitis B surface antigen was considerably increased after preincubuation of liver sections with 2-mercaptoethanol that removed most of the originally present albumin. This may be indicative for the role of disulfide bonds in the formation of hepatitis B surface antigen-albumin complexes. These results justify the hypothesis that albumin may be incorporated into the viral coat protein during its synthesis in the cytoplasm of infected hepatocytes.

Acute Disease↗
PubMed1979

Constitutive mutation of cysJIH operon in a cysB deletion strain of Salmonella typhimurium.

In a cysB deletion strain a new mutation, denoted cys-2332 was isolated, which causes the constitutive expression of the cysJIH operon. cys-2332 is closely linked to cysJIH and presumably is located in the initiator region of this operon, rendering its expression independent of the cysB gene product and the internal inducer O-acetyl-L-serine. The presence of sulfite reductase (encoded by cysI and cysJ) activity in a cysB- cys-2332 double mutant indicates that cysG, which is not linked to cysJIH but is required for the synthesis of the sulfite reductase co-factor siroheme, is not controlled by cysB.

Chromosome Mapping↗
PubMed1979

[The effect of carbocromen on the respiratory function of rat heart mitochondria].

Rat heart mitochondria were isolated by a slightly modified method of Sordahl. The influence of carbocromen (Intensaín) on the respiratory function of the tightly coupled or uncoupled mitochondria was tested in the presence of the respiratory substrates pyruvate, alpha-ketoglutarate, D,L-palmitoylcarnitine, L-palmitoylcarnitine, and D,L-acetylcarnitine. Carbocromen (0.089--0.89 mmol/l) did not change the P/O ratio, but reduced the rate of oxygen consumption (QO2) of the coupled mitochondria by about 20% when palmitoylcarnitine was used as respiratory substrate. With ADP in excess (5 mmol/l) carbocromen decreased QO2 in state ST3 by about 35%. This drug induced reduction of QO2 is still much more evident in uncoupled mitochondria (18% with 0.045 mmol/l carbocromen, 70% with 0.89 mmol/l carbocromen). In the presence of pyruvate as substrate the respiratory function of the coupled and uncoupled mitochondria remained nearly unchanged after adding the drug. It is discussed that carbocromen could interact with the complex enzyme dependent transport of long-chain fatty acids through the mitochondrial membrane.

Adenosine Diphosphate↗
PubMed1978

[Autoradiographic studies on the distribution of 14C-piracetam in the simian brain].

Autoradiography of the brain of the monkey Callithrix jacchus 2 and 6 h after oral application of 200 mg 14C-piracetam/kg (2-oxo-pyrrolidine-l-acetamide-2-14C) shows that the drug is preferably concentrated in the cortex of cerebrum and cerebellum. This specific affinity of piracetam which was observed earlier in dog and rat is thus confirmed in the primate and seems to be species independent. Beside the dominant cortical concentration there is a characteristic storage of piracetam in many nuclei of other brain areas, for instance, nucleus caudatus, hippocampus, n. anteriores thalami, n. dorsales thalami, corpus geniculatum laterale and mediale, corpora mamillaria, nucleus supraopticus, substantia grisea centralis, colliculi superiores and inferiores. Furthermore piracetam is stored in the blood vessel wall of the brain over 6 h. The hypophysis and pineal body take up radioactivity intensively.

Animals↗
PubMed1976

[Autoradiographic and scintillationspectrographic studies of 14C-zolimidine in rats after i.v. and oral application (author's transl)].

The relative distribution of radioactivity after i.v. (5 mg/kg) and oral (25 mg/kg) application of 14C-Zolimidine [2-(p-methyl-sulfonylphenyl)-imidazo-(1,2-a)-pyridine-2-14C] was examined in male rats by whole-body autoradiography and scintillation fluid spectrometry. 14C-Activity was remarkably concentrated in the stomach of i.v. treated animals, probably as a result of secretion from the pyloric and/or fundic part of the mucous membrane. 14C-Zolimidine also accumulated in the aortic vascular walls, the adrenal gland, and in the excretory organs, liver, kidney, and intestine, after both routes of drug administration. Much less radioactivity could be measured in brain and spinal cord. The estimation of nearly 80% gastrointestinal absorption of 14C-zolimidine and the suggestion of one or more metabolites were in accordance with previously reported results. The elimination of radioactivity from brain occurred more rapidly than from other organs. No striking results were found in the reproductive organs of the rats.

Administration, Oral↗