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Biomedical subjects

P S Nikov

Publications and source records attributed to P S Nikov.

16 recordsLinked to original sources
PubMedDate not supplied

[Characteristics of the microflora of food products from the southwest zone of Kazakhstan].

The question as to the prevalence of toxigenic microscopic fungi in foodstuffs originating in Kazakhstan is but little studied. In particular, no information on the microflora in the products coming from the south-western areas of the republic are available. The paper brings forth the results consequent upon the study of the problem in the Guriev and Dzhambul regions typical of this area. Microflora in 317 samples of various foodstuffs (wheat grains, flour and mealy products, rice, husket millet, dried meat, etc.) taken in rural families was studied by conventional methods. A highly frequent and intensive contamination of the vegetable and animal products with micomycetes, among which a definite prevalence of the species belonging to genus Aspergillus was noted. Aspergilli were represented mainly by the species known by their toxigenicity (A. flavus, A. fumigatus, A. candidus, A. niger, A. versicolor and others). A conclusion is drawn as to a potential hazard of mycotoxicoses arising in the south-western part of Kazakhstan. Recommendations for instituting preventive measures are given.

Food Contamination↗
PubMedDate not supplied

[Improved sanitary bacteriological control of dairy production].

Investigation of bacterial contamination in curds and sour cream, and experimental studies on survival rate of a number of pathogenic and opportunistic microorganisms in these products have permitted standardization of the products with respect to coliform bacteria. A permissible level has been determined for bacterial contamination of curds and sour cream.

Bacteria↗
PubMedDate not supplied

[Effect of the type of nutrition and aflatoxin B1 on the structure of chromosomes].

Deficiency of the essential nutrients lysine, methionine, threonine and vitamins A, E, C significantly increases the mutagenic environment of somatic cells in growing Wag rats. Aflatoxin B1 produces a pronounced mutagenic effect on the cellular genetic apparatus; this effect is substantially modified due to the nutrition character: it is either intensified or inhibited. The results obtained suggest that the nutritional factors can de used for prevention and elimination of aflatoxin B1-induced mutations.

Aflatoxin B1↗
PubMedDate not supplied

[Effect of qualitatively varying nutrition on several parameters of aflatoxin B1 metabolism and toxicokinetics].

The influence of qualitatively different nutrition (physiological and that with lysine, methionine, threonine and vitamins A, B, C deficiencies) on certain toxicokinetic parameters of 3H-aflatoxin B1, after single and multiple (every day, during 5 days) intraperitoneal injections of this agent in a dose of 25 micrograms/animal, was studied in two series of experiments on growing male WAG rats with the initial bw 40-50 g. It has been proved that the main parameters of aflatoxin B1 toxicokinetics depend on the injection multiplicity and the nutrition character. It has been established that the qualitative differences in the nutrition character essentially influence the stages of aflatoxin B1 distribution in the body, the sorption and metabolic transformation in the liver, enterohepatic recirculation, the rate and correlation of the main elimination routes. The nutrition character influences the level of persistence and cumulation of firmly bound aflatoxin B1 adducts in the liver and hepatocytic DNA. Possible mechanisms of such effects of different providing of the body with essential nutrients have been discussed. A conclusion has been made that the modifying effect of nutrition on the key stages of aflatoxin B1 toxicokinetics is realized, ultimately, in varying degree of the animal resistance to mutagenic and carcinogenic action of this agent.

Aflatoxin B1↗
PubMedDate not supplied

[Various aspects of the effect of nutritional factors on the metabolism and biological action of aflatoxin B1 in the rat liver].

Interrelationships between the quality of nutrition, oxidative hydroxylation of aflatoxin B1 and lipid peroxidation were studied in biomembranes of hepatocyte endoplasmic reticulum of growing male rats of the WAG strain. Activity of the liver microsomal monooxygenase, lipid peroxidation as well as metabolism of aflatoxin B1 were shown to depend on presence of three essential amino acids (lysine, methionine and threonine) and vitamins A, E and C. Deficiency of these compounds altered the aflatoxin metabolism causing formation of highly reactive metabolites, which might accelerate the carcinogenic effect of the xenobiotic. However, formation of free toxic metabolites of aflatoxin was stimulated under conditions of balanced nutrition as a result of which its toxic effect might be increased.

Aflatoxin B1↗