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Biomedical subjects

K Kuroda

Publications and source records attributed to K Kuroda.

At least 433 records · Page 24Linked to original sources
PubMed1981

Doses of antibiotic in patients with renal insufficiency.

The pharmacokinetic properties of cefotaxime were studied in 30 subjects with various degrees of renal function after a single 1-gm intramuscular injection. Serum and urinary concentrations of cefotaxime and desacetyl cefotaxime were determined by high-pressure liquid chromatography. The pharmacokinetic parameters were obtained using a one-compartment open model. A significant (P less than 0.0001) linear correlation was demonstrated between the elimination rate constant of cefotaxime and creatinine clearance. The mean serum half-life of cefotaxime was 0.86 hour in normal subjects and was prolonged to 2.35 hours in hemodialysis patients. The mean 24-hour urinary recovery was 51.7% as cefotaxime and 25.6% as desacetyl cefotaxime in normal subjects. In the present study, modification of the dosage is probably unnecessary in patients with creatinine clearance of more than 30 ml/min; however, dose reduction or prolongation of dosage interval, or both, may be appropriate in patients with severe renal dysfunction.

Anti-Bacterial Agents↗
PubMed1981

Analysis of loss of nuclear RNA in azo dye-induced hepatoma by DNA-RNA competitive hybridization.

DNA-RNA hybridization studies, using nuclear RNA's (nRNA's) labeled in vivo and in vitro with high specific radioactivities, were performed to compare the nRNA populations of normal rat liver, livers treated with 3'-methyl-4-dimethylaminoazobenzene (3'-Me-DAB), and 3'-Me-DAB-induced hepatomas. The study with normal liver nRNA labeled by i.p. injection of [3H]orotic acid indicated that the nuclei of a 3'-Me-DAB-induced transplanted hepatoma, AH136B, lacked some RNA species present in normal liver nuclei. No qualitative difference in thee RNA populations was seen between normal liver and the livers of rats fed a carcinogenic amount of 3'-Me-DAB, either alone or in combination with 4-nitrostilbene which enhanced the azo dye carcinogenesis. Then, nRNA's of both normal liver and AH136B hepatoma were labeled in vitro by phosphorylation with polynucleotide kinase and adenosine 5'-[gamma-32P]triphosphate. The competitive hybridization with 32P-labeled normal liver nRNA was competed, and the deletion of RNA in the nuclei of AH136B hepatoma or 3'-Me-DAB-induced primary hepatoma was estimated to be 15% or more in the measure of radioactivity of the hybridized normal liver nRNA. 32P-labeled AH136B hepatoma nRNA was completed completely by liver nRNA's, suggesting that no unique RNA species were present in the hepatoma nuclei.

Animals↗
PubMed1981

Antitumor and anti-intoxication activities of fumaric acid in cultured cells.

Fumaric acid, isolated as the active component of Capsella bursa-pastoris herb for inhibiting the solid growth of Ehrlich tumor in mice, was found to reduce markedly the growth and viability of Ehrlich, MH134, and L1210 mouse tumor cells in culture at concentration of 0.3 approximately 1.2 mg/ml. In contrast, fumaric acid at these concentrations in the culture medium had no deleterious effect on the monolayer development of mouse and chick embryo cells but exhibited activity to enhance the recovery of the cells from the toxic effects of mitomycin C, aflatoxin B1, N-methyl-N'-nitro-N-nitrosoguanidine, and potassium 1-methyl-7-[2-(5-nitro-2-furyl) vinyl]-4-oxo-1,4-dihydro-1,8-naphthyridine-3-carboxylate.

Animals↗
PubMed1980

Perthes' disease--a classification based on the extent of epiphyseal and metaphyseal involvement.

A tentative classification of Perthes' disease according to the extent of epiphyseal and metaphyseal involvement in lateral radiographs of the hip was applied to 61 hips in 55 patients. Forty-four hips were treated by containment (Tachjian's trilateral socket hip abduction orthosis) and 17 hips were treated surgically either by intertrochanteric or sub-trochanteric osteotomy. The results correlated well with the classification of the authors. The greater the extent of involvement of the epiphysis and metaphysis, the severer the resulting deformity. The choice of method of treatment is also discussed. It is concluded that this classification may be of prognostic value and may be useful to differentiate atypical cases.

Child↗
PubMed1980

Giant protoplasts from Nitella cells.

The process converting an intact Nitella cell into a protoplast was recorded continuously by means of time-lapse cinematography. The mechnican properties of these enzymatically isolated protoplasts were examined by several methods.

Cell Wall↗
PubMed1980

Enhancement of phospholipid transfer from Sendai virus to erythrocytes is mediated by target cell membrane.

Transfer of phospholipid from the envelope of Sendai virus to erythrocyte membrane was measured by using spin-labeled phosphatidylcholine. The transfer was enhanced autocatalytically above a threshold dose (about five adsorbed viruses per cell). There was an inflection point in the time course of transfer, after which the transfer was greatly accelerated. The time to reach the inflection point became shorter with increased viral dose. The transfer reaction was markedly enhanced above 19 degrees C and the inflection point was observed above this temperature. There was negligible transfer from trypsin-treated virus to erythrocyte membrane, but the transfer was greatly enhanced by intact virus. The enhancement was larger with increased amount of intact virus, and the inflection point was observed in the transfer curves. All the kinetic data can be satisfactorily analyzed by a model which assumes that the virus modifies the cell membrane at the attachment site, the modification is propagated in the membrane, and transfer of phospholipid to the modified sites is greatly enhanced. The propagation rate is estimated as approximately equal to 10(-11) cm2s-1 and the activation energy as 13 kcal mol-1 (54 kJ mol-1). The viral F glycoproteins are suggested as a possible entity for the modification and its propagation: they are introduced into the target cell membrane by envelope fusion, diffuse laterally, and enhance both phospholipid exchange and envelope fusion with viruses attached to the membrane sites.

Erythrocyte Membrane↗
PubMed1980

Ligand bindings of bovine carboxypeptidase B. III. Hydrophobic activators in dipeptide hydrolysis.

Several hydrophobic compounds acted as activators in dipeptide (Bz-Gly-L-Arg-OH, Z-Gly-L-Phe-OH) hydrolysis by bovine carboxypeptidase B. These hydrophobic compounds include Bz-Gly-OH, Z-Gly-OH, Z-L-Phe-OH, and Z-L-Phe-GLy-OH. These compounds were indicated to bind to the secondary substrate binding sites which is proposed to be responsible for substrate activation kinetics in dipeptide hydrolysis. Of the compounds Z-L-Phe-OH alone acted also as a inhibitor at higher concentrations, indicating that it binds to both primary and secondary sites as the dipeptide substrates do. Comparison of the activation effects of the compounds employed indicated that hydrophobic interaction played an important role in binding to the secondary site. Substrate and modifier binding constants were also determined and the results indicated that modifier binding increased both affinity and catalytic rate constant of the primary site. On the other hand, Z-Gly-OH and Z-L-Phe-Gly-OH inhibited the hydrolyses of tri and tetrapeptide substrates. This observation suggests that the secondary site is contained in the extended active center which the enzyme possibly has.

Alcohols↗
PubMed1980

Pharmacokinetics of cefmetazole in normal subjects and in patients with impaired renal function.

The pharmacokinetics of cefmetazole, a new cephamycin antibiotic, were examined after a 1-h intravenous drip infusion of 1 g to 5 healthy volunteers with normal renal function and 16 patients with impaired renal function. Peak serum concentrations were obtained at the end of the infusion in all subjects, regardless of their renal function. Approximately 70% of the infused dose was excreted in the urine within 6 h in healthy volunteers. The pharmacokinetic parameters of cefmetazole were derived by analyzing elimination data, with a one-compartment open model. The mean serum half-life of cefmetazole in healthy volunteers was 0.81 h. A significant correlation between the elimination rate constant and the creatinine clearance was demonstrated.

Adult↗
PubMed1980

Pharmacokinetics of ceftezole in patients with normal and impaired renal function.

The pharmacokinetics of ceftezole, a new cephalosporin antibiotic, was studied in 15 patients with normal and impaired renal function after administering the drug in a 2-hour intravenous drip infusion of 2 g. 81% of the infused dose was excreted in the first 6 h urine of the patients with normal renal function. The pharmacokinetic parameters of ceftezole were obtained by analyzing the serum level data of the drug using a one-compartment open model. The mean serum half-life of ceftezole was 0.64 h in patients with normal renal function and was prolonged to 10.7 h in patients with severely impaired renal function (creatinine clearance: 0-2.6 ml/min.). There was a significant linear correlation between the elimination rate of the drug and creatinine clearance.

Adult↗