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Biomedical subjects

K Kuroda

Publications and source records attributed to K Kuroda.

At least 361 records · Page 20Linked to original sources
PubMed1986

Fumaric acid enhances DNA synthesis of rat hepatocytes by counteracting the toxicities of mitomycin C and aflatoxin B1.

The effect of fumaric acid was examined on DNA synthesis in hepatocytes or hepatoma cells from rats treated with toxic agents. Male Donryu rats were injected with mitomycin C or aflatoxin B1, singly or in combination with fumaric acid. After a specified period, hepatocytes were isolated from the liver by the collagenase perfusion method and placed in culture, and their activities for DNA synthesis were measured. The iv injection of rats with mitomycin C (0.5 mg/kg) reduced the semiconservative DNA synthesis of the hepatocytes, but simultaneous dosing of fumaric acid (40 mg/kg) enhanced the recovery of the DNA synthesis. The DNA synthesis of hepatoma cells, a 3'-methyl-4-(dimethylamino)azobenzene-induced transplantable cell line growing in the abdominal ascites of rats, was also reduced by the iv injection of mitomycin C but, in contrast to that of the hepatocytes, was little influenced by the simultaneous dosing of fumaric acid. The ip injection of fumaric acid also reduced the toxicity of aflatoxin B1 (0.25 mg/kg, ip), preventing the reduction of DNA synthesis as well as the occurrence of nuclear degenerative changes in the aflatoxin B1-exposed hepatocytes.

Aflatoxin B1↗
PubMed1985

Kinetic analysis of fusion of hemagglutinating virus of Japan with erythrocyte membrane using spin-labeled phosphatidylcholine.

HVJ* (hemagglutinating virus of Japan containing spin-labeled phosphatidylcholine in its envelope around 10 mol %) was adsorbed onto erythrocytes or erythrocyte ghosts at various doses, and the ESR spectrum of the virus-cell system was measured at 37 degrees C. The peak-height increase for the HVJ*-ghost system was satisfactorily analyzed on the basis of envelope fusion by a first-order kinetic equation with two different rate constants. The rate constant was obtained as k1 = 0.84 min-1 and k2 = 0.011 min-1, independent of the virus dose. The fraction of virus fused at the rate constant k1 decreased with the dose. However, the average number of fast-fusing viruses per cell was nearly independent of the dose, and the value was one to two. The peak-height increase in the HVJ*-erythrocyte system was caused by both envelope fusion and phospholipid exchange catalyzed by the virus-induced hemolyzate. At lower doses, where the virus-induced hemolysis was small and, therefore, the rate of phospholipid exchange was small, the peak-height increase could be analyzed by the same kinetic equation with nearly the same rate constant value for k1 as that for HVJ*-ghosts. However, the k2 was larger than that for HVJ*-ghost, owing to the additional transfer by phospholipid exchange.

Electron Spin Resonance Spectroscopy↗
PubMed1985

Haemagglutinin transport mutants.

Two mutants (ts1 and ts651) with a temperature sensitive defect in the intracellular transport of the haemagglutinin from the rough endoplasmic reticulum to the plasma membrane have been analysed. Nucleotide sequencing of the haemagglutinin revealed with each mutant two point mutations that are located in the stem region of the molecule.

Base Sequence↗
PubMed1985

A predicted case with neonatal transient hypothyroidism due to blocking type thyrotropin binding inhibitor immunoglobulins (TBII).

A 26-yr-old female with primary hypothyroidism due to potent blocking type thyrotropin binding inhibitor immunoglobulins (TBII) was advised of the high risk of bearing a baby with neonatal transient hypothyroidism. This prediction proved valid and her baby was found to be hypothyroid with a potent TBII. By expressing the baby's TBII as the absolute concentration, we found an almost linear regression of TBII and the half-life was calculated as 18.0 days. The TBII became undetectable by the 6th month and thyroid medication was stopped, however the baby remained euthyroid with subsequent normal physical and mental development.

Adult↗
PubMed1985

[Therapeutic effect of Robaveron tablet (KN-7) on urinary disturbance by benign prostatic hypertrophy].

Therapeutic effect of Robaveron tablet (KN-7) was studied on 101 patients with urinary disturbance accompanied by benign prostatic hypertrophy. Robaveron tablet, which contains 20 mg of a swine prostatic extract per tablet, was administered 6 tablets daily for 3 weeks in principle. Evaluation of drug efficacy was based on residual urine, cystometric findings, urethral pressure profile, uroflowmetry and subjective symptoms. Remarkable decrease of residual urine was observed at all stages of Guyon classification, in parallel with increases of cystometric pressure amplitude and average flow rate. Rate of residual urine reduction rose in proportion to the higher stage or bulkier volume of residual urine. Improvements of subjective symptoms were also obtained. The overall effectiveness, rated slightly improved or better was 76.8%. Side effects were seen at a low rate of 3.9%, and there were no abnormal changes directly due to the drug in clinical laboratory tests. These results indicate that Robaveron tablets act on the detrusor muscle and contribute to improve the depressed voiding efficiency and incidental symptoms of the subjects.

Aged↗
PubMed1985

A search for nuclear RNA lost in azo dye-induced transplantable hepatoma.

Studies were conducted to characterize the nuclear RNA (nRNA) species that were present in rat liver but absent in the hepatoma. Nuclear RNA was compared between Donryu rat liver and AH136B hepatoma, an azo dye-induced transplantable cell line, by DNA-RNA competitive hybridization. The hepatoma lacked 13-14% of nRNA according to measurements of radioactivity of the hybridized 32P-labeled liver nRNA, and this loss was shown to be due to the failure to transcribe such RNA rather than to the deletion of the relevant DNA in the genome. Characterization of the lost RNA was first attempted by fractionating liver nRNA by density gradient sedimentation and polyacrylamide gel electrophoresis. A comparison of the additive effects of the fractionated RNA's in the competitive hybridization indicated that the pertinent RNA was present in the large RNA molecules (greater than 14S), not in the low molecular weight RNA's. Then poly(A) nRNA was found to show a strong additive effect in the competitive hybridization while nucleolar RNA showed little additive effect, indicating that the pertinent RNA was present in the heterogeneous nRNA, not in the ribosomal precursor. Further characterization was done by fractionating DNA with regard to the repetition in the genome. A comparison of the competitive hybridizations on the fractionated DNA's showed that the loss occurred mostly in RNA transcribed from highly repetitive DNA. In conclusion, the RNA species lost in the hepatoma were components of heterogeneous nRNA transcribed from highly repetitive DNA.

Animals↗