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Biomedical subjects

H Yoshihara

Publications and source records attributed to H Yoshihara.

At least 127 records · Page 7Linked to original sources
PubMed1984

[Mathematical simulation of the blood coagulation system].

The Blood coagulation system was converted to a mathematical model which was described using differential equations. The calculated output patterns of the mathematical model against various input stimulations were compared with results of in vitro assay. The simulated results of (1) Hemophilia A, (2) anticoagulation effect of antithrombin III and (3) anticoagulation effect of heparin corresponded to the results of in vitro assay and clinical reports. However, the simulated result of (4) anticoagulation effect of synthesized arginine derivative No. 805 (MD-805) did not correspond to the results of in vitro assay. Therefore, a new series simulation of MD-805 was done, supposing that MD-805 had an inhibitory activity not only on coagulation factor IIa but also VIIa. The new simulation pattern closely resembled the results of in vitro assay. From these facts, it was theoretically indicated that MD-805 also has an inhibitory activity on VIIa.

Adult↗
PubMed1984

[Infectious urachal cyst: a case report].

A case of an infectious urachal cyst that presented as a lower abdominal mass in a 44-year-old man is reported. There was no urinary tract infection. Cystoscopy revealed the dome retracted. All other investigations were normal without microscopic hematuria. Laparotomy revealed the mass attached to the small intestine because of infection. The mass was excised after partial resection of small intestine and partial cystectomy.

Adult↗
PubMed1983

Low Km ALDH isozyme and alcoholic liver injury.

To assess the relationship between the polymorphism of aldehyde dehydrogenase (ALDH) isozyme and alcoholic liver injury, ALDH isozyme was analyzed by isoelectric focusing electrophoresis in hair roots from normal volunteers and alcoholics with chronic liver disease. Liver biopsy specimens from alcoholics and non-alcoholics with chronic liver disease were also analyzed. It was found that (1) the frequency of low Km ALDH isozyme in hair roots from chronic alcoholics with liver injury was 90%, which was significantly higher than those from normal volunteers (44%) and from non-alcoholics with chronic liver disease (56%); (2) the isozyme pattern of liver specimens analyzed coincided with that of hair roots; (3) the low Km ALDH isozyme-positive subjects including alcoholics showed no facial flushing, and negative subjects showed facial flushing after drinking alcohol. It is concluded that a much higher frequency of low Km ALDH isozyme was found in chronic alcoholics with liver injury. There was no apparent difference in hepatic biochemical and histological findings between chronic alcoholics with and without low Km ALDH isozyme, suggesting that acetaldehyde does not play a primary role in the pathogenesis of alcoholic liver injury.

Acetaldehyde↗
PubMed1983

Effect of acute and chronic ethanol consumption on hepatic tissue oxygen tension in rats.

In vivo hepatic tissue oxygenation was investigated in chronically ethanol-treated rats using micro oxygen electrode and reflectance spectrophotometry. Effect of acute ethanol administration was also studied. Hepatic oxygen tension of rats treated with ethanol chronically (daily ethanol intake, 9-12 g/kg for 9 months) was very low as compared with that of normal rats, the decrease being comparable to that of rats treated with carbon tetrachloride. The hepatic oxygen tension in normal controls shortly after ethanol ingestion increased from basal level (median, 23 mmHg) to 40-70 mmHg, while in chronically ethanol-treated rats, the hepatic oxygen tension decreased transiently, followed by a gradual increase, but it still remained low. In CCl4-treated rats, the hepatic oxygen tension decreased further after the ethanol ingestion. It is concluded that chronic ethanol consumption in rats resulted in hepatic hypoxia with decreased liver blood flow and volume. Also acute ethanol administration does not induce hepatic hypoxia in normal rats, while in rats with injured liver it induces hypoxia.

Alcoholism↗
PubMed1983

[Post-operative suppression of natural killer activity].

The effects of anesthesia and surgical procedures on natural killer (NK) cell activity were studied. The data indicated that splenic lymphocytes taken from mice 1 to 5 days after surgery showed significantly diminished activity of natural killing. When splenic lymphocytes were treated by anti-Thy 1 antibody and complement, NK activity to Lewis lung carcinoma cells was remarkably depressed in normal mice, but was not depressed in laparotomized mice. Peripheral lymphocytes from cancer patients following major surgery also showed depressed NK activity. The suppression was first detected during the operation. In patients undergoing major gastrointestinal surgery, the suppression was at its maximum during first three days and decreased to control levels by the day 7 to 14. Following major thoracic surgery, the suppression continued more longer.

Animals↗
PubMed1982

[Effect of NK-421 (Bestatin) and Ge-132 on the cytotoxicity of spleen cells obtained from the tumor-bearing mice].

The effect of NK-421(Bestatin) and Ge-132 (an organic germanium compound) on the ADCC and natural killing (NK) activities of the spleen cells of MH-134 tumor-bearing mice were studied. In the tumor-bearing mice, the ADCC activity was enhanced, and NK activity was reduced in accordance with the progress of the tumor. By oral administration of Bestatin at doses of 5, 10 and 50 mg/kg, ADCC activity was potentiated, and at a dose of 10 mg/kg, NK activity was significantly increased. Intraperitoneal administration of Ge-132 at 50 mg/kg potentiated the ADCC activity of tumor-bearing mice. A higher activity was observed in the plastic dish adherent fraction. Ge-132 also potentiated the reduced NK activity of tumor-bearing mice to higher level than normal mice. The elevated activities of ADCC and NK following Bestatin and Ge-132 administration were decreased with anti-Thy-1 antibody and complement; however, the percent reduction was lower compared to that of the control cancer animals. This result indicates that Bestatin and Ge-132 may act on non-T cells and augment ADCC and NK activities.

Adjuvants, Immunologic↗
PubMed1978

Bovine thymus poly(adenosine diphosphate ribose) polymerase.

About 1,300-fold purification of poly(adenosine diphosphate ribose) polymerase has been achieved from the extract of bovine thymus with a recovery of 10 to 20%. The final preparation has a purity of 99%, and the enzyme is composed of a single peptide with a molecular weight of 130,000. The purified enzyme required NAD+, Mg2+, a thiol compound, DNA, and histones for full activity. Whereas DNA is essential for activation of the enzyme, histones are not. The observed stimulation of the reaction by histones is shown to be due to masking of the inhibitory effect of contaminating denartured DNA in native DNA preparation. The concentration of DNA required for half-maximal enzyme activity (apparent Km for DNA) is proportional to the concentration of enzyme in the reaction mixture. The minimum estimation of the number of nucleotide pairs of DNA required for half-maximal activation of one enzyme molecule is 220 to 240 for bulk of calf thymus DNA, while the value is 10 for a calf thymus DNA fraction, "active DNA," which was separated from the enzyme fraction in a stage of the purification. These results suggest that the enzyme is activated by binding to a specific site on calf thymus DNA. The apparent Km for NAD+ and the maximum velocity of the enzyme are estimated to be 60 micrometer and 0.91 mumolper min per mg, respectively.

Animals↗
PubMed1978

Response of neonatal mouse lung in organ culture to silica.

Short term organ cultures of lung fragments from neonatal mice maintain their normal architecture. Cultures exposed to silica flour in varying concentrations show effects resembling those seen in chronic silicosis produced by inoculation and inhalation methods.

Lung↗
PubMed1976

Deep temporal lobe projections to the nucleus of the diagonal band of Broca.

Electrophysiological studies with acutely prepared cats found that stimulation of deep temporal lobe structures (e.g., amygdala, prepyriform cortex) evoked responses in the nucleus of the diagonal band of Broca. An analysis of field, extra- and intracellular unitary responses points to the existence of a monosynaptic excitatory connection.

Amygdala↗