Biomedical subjects
Publications and source records attributed to S P Ponomarenko.
Malignant melanoma morbidity in Khabarovsk Territory in 1973-1983 was studied. The data on 214 primary patients were analysed. In 1981-1983 morbidity level showed an 1.7-1.8-fold increase as compared with 1973-1975. Skin melanoma ranked first; it was followed by that of the eye. Skin melanoma predominated in patients with the light-color skin. Melanoma was not registered in the aborigines living in the north of the Territory.
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Kinetics of co-oxidation of 1-benzen-3-carbamido-1,4-dihydropyridine (BDN) and phenylglyoxal (PG) with hydrogen peroxide is studied. Dimeric product (di-e11-benzen-5-carbamido-1,2-dihydropyridyl-2]) is found to be formed at pH 9, and quaternal pyridinium salt (BNA)--at pH 7. Molecular oxigen is determined to participate in the reaction at pH 7. Copper (II) ions catalyze this process. Significant catalytic effect of p-dinitrobenzen (p-DNB) is found. The reaction mechanism is postulated to form hydroperoxide from PG and hydrogen peroxide which are capable to split the hydrogen attom from dihydropyridine, molecular oxigen or p-DNB being an acceptor of the electrone. Hypothesis on separate transfer of hydrogen atom and electrone in biological systems are proposed.
Biostimulants ivin and emistym take positive effect on the growth characteristics of natural association of soil microorganisms: they increase the specific growth rate, the number of generations, decrease the lag-phase and duration of redoubling the number of microorganisms. Presence of fungicides in the medium inhibits the growth of microorganisms. Under combined use of biostimulants and fungicides one cannot reveal the negative effect of fungicides on the natural associations of microorganisms, however the stimulating action of growth-regulating substances decreases.
Natural and synthetic biostimulants have been studied for their effect on resistance of soil microbe associations to pesticides. It has been shown that in the presence of growth-stimulating preparations (ivin, emistym, agrostimulin) in the microbial groups the number of microorganisms resistant to such fungicides as phenpiclonyl, fluodioxonyl, diphenoconasol increases. The activity of redox-systems which can initiate the oxidative destruction of pesticides increased in microbial associations under the simultaneous use of biostimulants and fungicides.
The paper deals with the mechanism of some model reactions of NAD and NADP which proceed with transfer of one electron and hydrogen atom. The joint oxidation of N-benzyl-1,4-dihydronicotinamide (I) and phenylglyoxal with hydrogen peroxide in the presence of cupric ions is found to result in transfer of one hydrogen atom from dihydropyridine molecule to hydroxy-radical and the electron to a molecule of oxygen or dinitrobenzene. The oxydation of I with benzoquinone is found to proceed with formation of free radicals as intermediate. The mechanism of NAD reduction with sodium hydrosulphite is proposed.