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K Hasuda

Publications and source records attributed to K Hasuda.

30 records · Page 2Linked to original sources
PubMed1989

Efficacy of two-route chemotherapy using intraperitoneal neocarzinostatin and its antidote, intravenous tiopronin, for peritoneally disseminated tumors in mice.

We assessed the efficacy of "two-route chemotherapy (TRC)" using neocarzinostatin (NCS) given ip and its antidote, N-(2-mercaptopropionyl)-glycine (tiopronin), given iv for peritoneally disseminated tumors in mice. Whether or not the single iv administration of tiopronin (800 mg/kg) at various times after NCS ip would decrease the lethal toxicity induced by NCS ip was given attention. When compared with the LD50 (4.4 mg/kg) of NCS ip alone, simultaneous or postadministration of tiopronin together with NCS ip increased the LD50 of NCS ip by 2.8 to 7.6 fold in a time-dependent manner. Chemotherapy experiments on ip disseminated tumors in mice were done to compare the antitumor effects of the following treatments, at two dose levels (75 and 100% of LD10) of NCS, with or without tiopronin: treatment with NCS ip alone and combined chemotherapy using NCS ip plus tiopronin iv, simultaneously or postadministered. Based on the survival time of the treated mice, the groups given NCS plus tiopronin (postadministration, 15 or 25 min later) showed a significantly superior survival time to that of the group given NCS ip alone. The side effects, evaluated in terms of the changes in body weight and number of WBC of the mice, were not significantly different among the groups treated with 100% of LD10 of NCS.

Animals↗
PubMed1987

Efficacy of two-route chemotherapy using cis-diamminedichloroplatinum(II) and its antidote, sodium thiosulfate, in combination with angiotensin II in a rat limb tumor.

We combined the angiotensin II (AT-II)-induced hypertension method with "two-route chemotherapy" (TRC), using cis-diamminedichloroplatinum(II) (CDDP) and its antidote, sodium thiosulfate (STS). The efficacy of the modified TRC was evaluated in rats bearing a limb tumor (transitional cell carcinoma). Immediately after infusing CDDP (15 mg/kg) and AT-II (15 micrograms/kg) via the femoral artery for 5 min, 1580 mg/kg STS (200-fold molar ratio to 15 mg/kg of CDDP) were administered i.v. for a further 5 min. Other treatments were as follows: 5 mg/kg of CDDP mixed or not mixed with 15 micrograms/kg of AT-II were given intraarterially (i.a.); 5 mg/kg of CDDP alone were injected i.v.; CDDP (15 mg/kg, i.a.) and STS (1580 mg/kg, i.v.) were simultaneously administered, without AT-II (conventional TRC). The antitumor effects of the modified TRC, evaluated by regression of tumor growth and extended life span, were superior to the other treatments. On the other hand, nephrotoxicity, loss of body weight, and leukopenia, seen in the rats given TRC with AT-II, occurred less than or at the same rate as in rats given other treatments. Thus, the TRC with AT-II was the most effective treatment given to rats bearing a regionally confined tumor. The feasibility of clinical application of modified TRC using i.a. CDDP plus AT-II and i.v. STS is discussed.

Angiotensin II↗
PubMed1987

Potentiation of cytotoxicity of zinostatin under acidic conditions in vitro and in vivo.

The cytotoxicity and antitumor effects of zinostatin (NCS) were examined under various conditions of pH using cultured HeLa cells and a transplantable tumor line of WKA rats. The cytotoxicity of NCS against HeLa cells was highly dependent on the pH at ranges of 6-8. When HeLa cells were treated with 0.075 microgram/ml of NCS, the survival rate was about 1% at pH 6.0, while it was near 90% at pH 7.4 and pH 8.0. Even at pH 6.5-6.75, the survival rate was about 50% lower than that seen with pH 7.4 and pH 8.0. The ratio of the dose of NCS for a 90% cell mortality at pH 6.0 to that at pH 7.4 was less than one-seventh. Antitumor effects were assessed by local intra-arterial infusion against tumors 4 or 9 days after inoculation of 10(6) RBT-1 tumor cells into the thigh of rats. When NCS (0.7 mg/kg) in phosphate-buffered saline (PBS) (pH 7.4) or 5 mM lactate (about pH 3.0) was administered, the ratio of average tumor weight about 2 weeks after treatment (tumor weight of the rats given NCS in PBS/tumor weight of the rats given NCS in lactate) was 3.2 or 1.7 for the rats treated 4 or 9 days after tumor inoculation, respectively. Lactate or PBS alone had no effect on the growth of tumor. After treatment there was no difference in body weight change between the group treated with NCS in lactate and the group treated with NCS in PBS. We conclude that the cytotoxicity of NCS was potentiated under acidic conditions, both in vitro and in vivo.

Animals↗
PubMed1976

Classification of R plasmids by incompatibility in Pseudomonas aeruginosa.

R plasmids identified in Pseudomonas aeruginosa strains isolated in our laboratories were classified by their incompatibility characters by using intraspecies conjugation in P. aeruginosa. The fertility factor, FP2, was compatible with R plasmids belonging to all groups, and was classified in a new group. From these data, the plasmids examined have been placed into seven or eight incompatibility groups.

Anti-Bacterial Agents↗
PubMed1975

R factor-mediated resistance to aminoglycoside antibiotics in Pseudomonas aeruginosa.

Conjugal transferability of drug resistance was examined, in eleven Pseudomonas aeruginosa strains which were isolated in Frankfurt. Four R factors were demonstrated from three strains using P. aeruginosa as recipients but they were nontransferable to Escherichia coli K12. Two R factors, i.e., Rms146 and Rms147, mediated resistances to tetracycline (TC), streptomycin (SM), sulfanilamide (SA), kanamycin (KM), lividomycin (LV), gentamicin C complex (GM) and 3', 4'-dideoxykanamycin B (DKB). They mediated the formation of aminoglycoside-inactivating enzymes, i.e., SM phosphotransferase, SM adenylyltransferase, KM and LV phosphotransferase l, and GM and DKB 6'-N-acetyltransferase. TC resistance conferred by these R factors was due to impermeability of the drug. P. aeruginosa Ps 142 carried two kinds of R factor in one cell, Rms148 (SM) and Rms149 (SM-SA-GM-CPC) (CPC, carbenicillin). Rms148 (SM) was transferable at a high frequency of 10-1 and mediated the formation of SM phosphotransferase. Rms149 mediated the formation of drug-inactivating enzymes, ie., GM 3-N-acetyltransferase and beta-lactamase, but did not inactivate SM. SM resistance was probably due to impermeability of the drug.

Acetyltransferases↗
PubMed1975

Gentic properties of an R factor carrying resistance to aminolgycoside antibiotics.

R factor Rms 151 is an fi+ R factor and belongs to a incompatibility group FII. It carries the genes governing resistance to various aminoglycoside antibiotics, i.e., kanamycin (KM), lividomycin (LV), gentamicin C complex (GM), and 3',4'-dideoxykanamycin B (DKB), in addition to those governing to tetracycline (TC), chloramphenicol (CM), sulfanilamide (SA), and ampicillin (APC). Electron microscopy observation disclosed that the Rms151 deoxyribonucleic acid was a circular form with length of 31.2 mum. A probable circular genetic map of Rms151 was proposed by genetic and biochemical studies, the genes being in the order of -tet-tra-amp-aad-sul-aph-cml-, in which aad and aph confer resistance to KM.GM.DKB by adenylytransferase or resistance to KM.LV by phosphotransferase, respectively.

Aminoglycosides↗
PubMed1974

Demonstration of R factors from Pseudomonas aeruginosa.

Sixty strains of Pseudomonas aeruginosa were selected from our clinical stock cultures and used as donors of drug resistance to examine the presence of R factors. They were highly resistant to one or more of six drugs including tetracycline (TC), chloramphenicol (CM), streptomycin (SM), sulfanilamide (SA), carbenicillin (CPC), and kanamycin (KM). Three FP(-), auxotrophic mutants of P. aeruginosa were used as recipients, which had been made resistant to either rifampin (RMP) or KM by in vitro mutation. Each donor was mated with each of the three recipients, and 45 strains were found to transfer their resistance to one or more recipients. A second series of conjugation experiments using 45 exconjugants as donors showed that 23 could transfer their resistance. We conclude that these strains carry R factors that are transmissible to one or more recipients. Eleven carried resistance to (TC.CM.SM.SA.CPC), nine to (TC.CM.SM.SA), one to (TC.CM.SA.CPC), one to (TC.CM.SA), and one to (SM). All of these R factors could not be transmitted to other species belonging to the family Enterobacteriaceae.

Anti-Bacterial Agents↗