[Enzyme activity changes in chronic alcoholic intoxication and the simultaneous administration of pyridoxine]. / Izmeneniia aktivnosti nekotorykh fermentov pri khronicheskoi alkogol'noi intoksikatsii i odnovremennom vvedenii piridoksina.

After prolonged application of ethanol the liver and brain of rats show an appreciable increase in lactate dehydrogenase activity, noticeable lowering of cytoplasmic aspartate and alanine aminotransferase activity, elevation of liver arginine succinate lyase activity with unchanged activities of other enzymes of the ornithine cycle (ornithine carbamoyltransferase and arginase), reduction of glutamate and malate dehydrogenase and mitochondrial aspartate aminotransferase activity in brain tissue. Concurrent application of ethanol and pyridoxine normalizes the effect of ethanol on liver arginine succinate lyase and on brain tissue lactate and malate dehydrogenase, mitochondrial and cytoplasmic aspartate aminotransferase and alanine aminotransferase.

Hamster apigmented melanoma as a model for screening of potential antineoplastic drugs.

The authors treated the apigmented melanoma IC-Sofia in hamster with various doses of the following cytostatics: Cyclophosphamide, 6-Mercaptopurine, Vinblastine and Actinomycin D for 7 consecutive days. Determination of the tumor growth inhibition on the 8th day (early test) on the basis of tumor weight in the animals treated and untreated with cytostatics indicates that the tumor used is more sensitive to the effect of Cyclophosphamide and 6-MP and less to Vinblastine and Actinomycin D. Nevertheless sensitivity to cytostatic action is high enough for each of the cytostatic agents, depending upon the applied dose. This gives grounds to the authors to assume that hamster apigmented melanoma IC-Sofia is an adequate model for testing and evaluation of antitumor drugs.

A precise radioimmunochemical method for determination of free insulin and insulin bound to serum proteins, including antibodies.

Polyethyleneglycol precipitation of insulin antibodies and insulin-antibody complexes is associated with co-precipitation of part of the free insulin. The recovery of free insulin was found to depend both on the quantity and quality of the antibodies and varied between 94% and 40%. Thus, the concentrations of free and total insulin may be lowered up to 2.5-fold in different sera containing endogenous antibodies. A critical evaluation of these results led to the development of a more reliable method for the assay of total and free insulin, based on individual radioisotopic determinations of the recovery of insulin extracted by PEG. The recovery of insulin added to sera containing antibodies as determined by the present method is within the range of 100 +/1 2.5%. In sera not containing antibodies total insulin concentration was found to be up to 5-times higher than that of IRI and to reach values above 250 muU/ml whereas whereas indirect IRI (i-IRI) may increase over 25 times with age.