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Biomedical subjects

T Uzawa

Publications and source records attributed to T Uzawa.

At least 37 records · Page 2Linked to original sources
PubMed1987

[General pharmacological studies on isepamicin sulfate (HAPA-B)].

General pharmacological properties of isepamicin sulfate (HAPA-B), a new aminoglycoside antibiotic, were studied in animals and the results obtained were summarized below. Intramuscular injections of HAPA-B at doses of 500 mg/kg inhibited the writing response induced by acetic acid, and at doses of 1,000 mg/kg, caused muscle relaxation, respiratory depression, suppression of spontaneous motor activity and prolongation of thiopental anesthesia. Anticonvulsive action and the effect on the rectal temperature were not observed. Intravenous Intravenous HAPA-B showed no significant effect on the general behavior and the function of the central nervous system at doses of 100 mg/kg. Intravenous injections of HAPA-B to anesthetized dogs resulted increases in the femoral arterial blood flow at doses of 12.5 mg/kg, decrease in the blood pressure and increase in the respiratory rate at doses of 25 mg/kg, and increase in the carotid arterial blood flow at doses of 50 mg/kg. Apparent changes were not recognized in the heart rate and electrocardiograms. In conscious rabbits, intravenous HAPA-B produced increases in the heart rate without significant changes of the blood pressure and electrocardiograms at doses of 100 mg/kg. Spontaneous beatings of isolated atria were depressed by HAPA-B in concentrations of 3 X 10(-4) to 10(-3) g/ml. The HAPA-B inhibited the gastric secretion at intramuscular doses of 500 mg/kg or intravenous doses of 100 mg/kg, and depressed charcoal transport through small intestine and the spontaneous movement of isolated ileum at intramuscular doses of 1,000 mg/kg and at concentrations of 3 X 10(-4) to 10(-3) g/ml, respectively. No irritative effect was found on the gastric mucous membrane. Intravenous HAPA-B inhibited the response of nictitating membrane to pre and post ganglionic stimulations of cervical sympathetic nerve at doses of 100 mg/kg. In in vitro test, HAPA-B inhibited nonspecifically the constrictive responses of trachea, aorta, stomach, ileum and vas deferens to various agonists in concentrations of 3 X 10(-4) to 10(-3) g/ml. Spontaneous movements of uteri of estrous or pregnant animals were depressed by HAPA-B at intravenous doses of 50 to 100 mg/kg and in in vitro at concentrations of 10(-4) to 3 X 10(-4) g/ml. Antidiuretic effect was also observed at intramuscular doses of 250 mg/kg. HAPA-B increased the length of the whole blood clotting time and raised the plasma glucose level at intramuscular doses of 1,000 mg/kg and inhibited the platelet aggregation induced by ADP in vitro at concentrations of 10(-3) g/ml.(ABSTRACT TRUNCATED AT 400 WORDS)

Aminoglycosides↗
PubMed1977

Hepatitis B e antigen and infectivity of hepatitis B virus.

For confirmation of the difference in the infectivity of hepatitis B surface antigen (HBS Ag)-positive serum according to differences in the e antigen system, four chimpanzees were inoculated with serum positive for hepatitis B e antigen (HBe Ag), and three chimpanzees were inoculated with serum positive for antibody to HBe Ag (anti-HBe). Since the infectivity titrations are not yet completed, the end infectivity titer of each serum is not known. All four chimpanzees given injections of 10(-1), 10(-4), or 10(-8) dilutions of HBe Ag-positive serum developed hepatitis B virus infection, whereas the one chimpanzee injected with undiluted anti-HBe-positive serum became infected, and other chimpanzees injected with diluted anti-HBe-positive sera did not. As judged from the length of the incubation period before appearance of HBS Ag in blood, there seemed to be a remarkable difference in infectivity between the HBe Ag-positive serum and the anti-HBe-positive serum; the former serum was 10(8) times more infectious than the latter.

Animals↗
PubMed1977

Hepatocellular carcinoma and chronic persistent hepatitis.

The morphologic type of cirrhosis that is followed most frequently by hepatocellular carcinoma is posthepatitic cirrhosis. Furthermore, HB AG is detected in a high rate among cases with hepatocellular carcinoma suggesting the intimate causal relationship between hepatitis b virus and hepatocellular carcinoma. It has been considered that hepatocellular carcinoma might develop during destruction and regeneration of fully developed liver cirrhosis. However, hepatocellular carcinoma is combined with not only liver cirrhosis but also with mild liver fibrosis. An attempt was made to determine HBs Ag in the liver tissue of liver fibrosis with hepatocellular carcinoma. HBs Ag was found in non-cancerous liver tissue of 40 percent of those cases. Therefore, it may be concluded that, at least some of those fibrosis is caused by chronic viral hepatitis and hepatocellular carcinoma may develop not only on posthepatitic cirrhosis but also on chronic persistent hepatitis. This evidence also suggests the carcinogenicity of hepatitis B virus.

Carcinoma, Hepatocellular↗
PubMed1975

HBc and HBs antigen in hepatocytes.

The relationship between the electron microscopical structures and the immunofluorescent appearance of HB antigen found in the hepatocytes of patients with HB antigenemia was carefully studied, with the purpose to clarify the nature of those structures. The nuclei of hepatocytes, containing numerous virus-like particles, showed positive immunoflourescence by antiserum against the core of Dane particles. The areas in which filamentous structures were observed in the cisternae of endoplasmic reticulums and hyaloplasma, corresponded to orcein or aldehyde-fuchsin positive substances in the light microscope, whereas direct relationship between filamentous structures and HBs antigen was still obscure. Accordingly, it may be concluded that virus-like particles in the nucleus correpond to core and filamentous structures in the cytoplasma correlate with coat protein of hepatitis B virus.

Animals↗