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Biomedical subjects

K Ando

Publications and source records attributed to K Ando.

At least 829 records · Page 46Linked to original sources
PubMed1976

Repair of potentially lethal radiation damage in acute and chronically hypoxic tumor cells in vivo.

The ability of animal tumor cells to repair potentially lethat damage was studied in vivo. Fifth-generation isotransplants of a spontaneous mouse squamous-cell carcinoma were irradiated under tourniquet-induced hypoxia or in air. Tumors were removed either immediately or 6 hours after irradiation and dose-response curves were determined by TD50 assays. Repair was attributed to cells in the hypoxic cell component for animals irradiated in air. Extensive repair was also noted for those irradiated under typoxic conditions. Implications of these results are discussed.

Animals↗
PubMed1976

Effects of chronic administration of kanamycin on conditioned suppression to auditory stimulus in rats.

The conditioned suppression technique was employed to study the ototoxic effects of chronic administration of the antibiotic, kanamycin. Lever pressing behavior for food reinforcement of rats was suppressed in the presence of an auditory stimulus (sound) or visual stimulus (light) that had been previously paired with electric shocks. Repeated administration of kanamycin at the dose of 400 mg/kg/day for more than 50 days significantly attenuated the conditioned suppression to auditory stimulus but did not attenuate the conditioned suppression to visual stimulus. This finding suggests that the attenuating effect of chronic administration of kanamycin on conditioned suppression to auditory stimulus can be interpreted in terms of the selective action of the drug on the auditory system.

Acoustic Stimulation↗
PubMed1976

Effect of D-Glucarates on basic antibiotic-induced renal damage in rats.

Dehydrated rats regularly develop acute renal failure following single injection of aminoglycoside antibiotics combined with dextran or of antibiotics only. Oral administration of 2,5-di-O-acetyl-D-glucaro-1,4-6,3-dilactone protected rats against renal failure induced by kanamycin-dextran. The protective effect was prevalent among D-glucarates, and also to other saccharic acid, hexauronic acids and hexaaldonic acids, although to a lesser degree, but not to a hexaaldose, sugar alcohols, substances inthe TCA cycle and other acidic compounds. D-Glucarates were effective against renal damage induced by peptide antibiotics as well as various aminoglycoside antibitocis. Dose-responses were observed in the protective effect of D-Glucarates. With a D-glucarate of a fixed size of dose, approximately the same degree of protection was obtained against renal damages induced by different basic antibiotics despite large disparities in administration doses of different antibiotics. D-Glucarates had the ability to prevent renal damage but not to cure it. Rats excreted acidic urine when they were spared from renal lesions by monosaccharides. The reduction effect of D-glucarates against nephrotoxicity of basic antibiotics was discussed.

Acute Kidney Injury↗
PubMed1976

Preventive effect of D-glucarate against renal damage induced by kanamycin.

Kanamycin-induced renal impairment in dehydrated rats was spared by the administration of sodium D-glucaro-1,4-lactone. In the plasma elimination and urinary excretion studies, D-glucarate-treated rats showed quick removal of the antibiotic from the body as compared with non-treated rats. Organ distribution study clearly demonstrated the potent nephrotoxicity of kanamycin and the reduction effect of D-glucarate against the nephrotoxicity. The drug level in the kidney in non-treated rats was more than two orders of magnitude higher than those in other organs such as the liver, lung and spleen, and remained high for 48 hours after antibiotic administration. In D-glucarate-treated rats the kidney content of the drug was diminished as compared with non-treated rats just after the antibiotic administration, followed by a gradual decline with time.

Animals↗
PubMed1976

[Effect of continuous bleomycin treatment and of oil-suspended bleomycin on experimental tumor growth (author's transl)].

Effects of continuous administration of bleomycin solution and of intralesional injection of sesame oil-suspended bleomycin on tumor growth were studied. Experimental animal tumors were 3 rd generation isotransplants of a spontaneous C3H mouse mammary carcinoma. Bleomycin treatments were started when transplanted tumors reached 8 mm in diameter and the measurement of tumor volume was followed. Dose administered was fixed as 100 mg/kg in all the groups. Bleomycin solution was given intralesionally in a single or 4 daily doses, or intraperitoneally by continuous infusion. The latter method inhibited tumor growth most effectively, while the single injection was the last effective. Intralesional injection of oil-suspended exhibited similar effectiveness as the continuous infusion, and it was independent of the number of fractions. These results were interpreted by the several features in the response of mammalian cells to the antibiotic.

Animals↗
PubMed1976

Combined use of bleomycin in radiotherapy of a mouse mammary carcinoma.

Experiments were carried out to determine TCD50 (50% tumor control dose) of 3rd generation isotransplants of a C3H mouse mammary carcinoma treated or not treated with Bleomycin. If the antibiotic was injected 30 min before a single X-ray dose, TCD50 was reduced. This reduction in TCD50 was independent of Bleomycin dose of more than 15 mg/kg, because of the upward-concave nature of Bleomycin dose-cell survival curve. The combined effect, when tested by TCD50 assays, appeared less than additive. This effect was further examined by a series of TD50 assays which revealed that these tumor cells were capable of repairing the potentially lethal damage induced by X-rays and that induced by Bleomycin. It was also found that the potentially lethal damage after combined X-ray and Bleomycin treatments was repaired. These findings indicated that the combined X-ray and Bleomycin treatment resulted in additive effect if the repair of potentially lethal damage in tumor cells were taken into account.

Animals↗
PubMed1975

Effect of ascofuranone on serum lipids of rats fed a cholesterol rich diet.

Ascofuranone, a fungal metabolite, significantly reduced serum lipid levels, when orally administered to male Wistar rats fed a cholesterol rich diet. The treatment also resulted in a marked reduction of hepatic and cardiac cholesterol contents without affecting the body weight gain. The serum albumin/globulin ratio increased significantly in the treated rats. This increase is presumably due to the decrease of beta-lipoprotein. The mode of action differentiates from clofibrate in so far as the former effectively prevents hepatic and cardiac cholesterol deposits in the cholesterol feeding rats.

Alanine Transaminase↗
PubMed1975

Isolation and characterization of mannopeptins, new antibiotics.

New antibiotics, mannopeptins A and B, were isolated from the fermented broth of Streptomyces platensis strain FS-351. Ferrous ion is essential for the antibiotic production, since no productivity was noted with media containing less than 0.11 mM ferrous ion and maximum production was achieved at a concentration of 1.8 mM. The antibiotics are basic glycopeptides with relatively high molecular weight and are similar to ristocetin and vancomycin but can be differentiated from them in view of their chemical composition and chromatographic behavior. The antibiotics were named mannopeptin after the glycopeptide containing mannose.

Amino Acids↗
PubMed1975

Antimicrobial properties of mannopeptins.

Mannopeptins show in vitro antimicrobial activity against gram-positive and some gram-negative bacteria. The antimicrobial activity is unaffected by the addition of serum, and potentiated by alkaline pH or decrease in inoculum size. The antibiotics exert bectericidal effect at doses twice as high as the minimum inhibitory concentration. When the antibiotics were injected into mice through either intravenous, intraperitoneal, intramuscular or subcutaneous routes, the antimicrobial activity appeared within 15 minutes in the serum of mice and was slowly excreted in the urine. However, the antibiotics were poorly absorbed by the oral route. The antibiotics were capable of protecting mice from lethal infection produced by the intravenous injection of Staphylococcus aureus, Streptococcus pyogenes and the intraperitoneal injection of Shigella sp. and Escherichia coli, but ineffective against Salmonella typhosa.

Administration, Oral↗
PubMed1975

Optimum fractionation regimen for bleomycin treatment.

A theoretical analysis was made on the optimum Bleomycin treatment regimen on the basis of the "binding-saturation model" which was proposed for the Bleomycin dose-cell survival relation. The surviving fraction of tumor cells decreased as a function of the number of fractionated treatments up to the optimum fractionation number if the tumor was treated with the same total dose. The effect of cellular sensitivity to the antibiotic, tumor doubling time, treatment interval, and total doses on the optimum regimen was analyzed. The importance of treatment interval and tumor doubling time was emphasized and the short treatment interval was recommended for the clinical use of this antibiotic. The optimum number of fractions increased linearly with the increase of the total dose while the optimum single dose was independent of the total dose. A concept of the tumor control probability of tumors treated with the optimum fractionation regimen was introduced and implications of these analyses in the clinical cancer chemotherapy were discussed.

Bleomycin↗