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Biomedical subjects

R V Baru

Publications and source records attributed to R V Baru.

18 recordsLinked to original sources

[Assessment of the mutagenic activity of aversectin C].

Aversectin C was evaluated for mutagenic activity in the Ames test with Salmonella typhimurium TA 97, TA 98 and TA 100, in the dominant lethal assay on uninbred albino rats in a dose of 2.25 mg/kg body weight (1/40 of the LD50) and in the metaphase test on F1CBAxC57BI/6 mice in a dose of 8.2 mg/kg body weight (1/5 of the LD50). The agent showed no mutagenic activity in any of the tests. The anaphase test on F1CBAxC57BI/6 mice revealed no antimitotic activity of aversectin C.

Anaphase↗

[Substantiation of hygienic standard of lincomycin in the air of the work area].

The main parameters of lincomycin toxicometry were studied in animals. It was shown that the compound was low toxic after its oral or intraperitoneal administration in single doses, had no local irritant and skin resorptive effects and did not accumulate. The allergenic properties were slightly pronounced. The intoxication picture after a single inhalation was characterized by renal dysfunction, erythropenia, neutrophilia, lymphopenia and impairment of the normal intestinal microflora. The zone of the specific antimicrobial effect was equal to 8. On chronic inhalation, the signs of the specific antimicrobial effect were of the paramount importance: Limch am was equal to 4.7 mg/m3 and Limch exceeded 18.3 mg/m3. In the concentrations used, the substance had no embryotoxic and gonadotropic effects. The level of 0.5 mg/m3 (for Hazard Class 2) was recommended and approved as the maximum allowable concentration.

Air Pollutants, Occupational↗

[Evaluation of the antimicrobial action of substances for the setting of hygienic standards].

The notion of antimicrobial effect threshold as an index of hygienic importance for toxicological estimation of chemotherapeutic agents is grounded by the generally accepted conception of thresholds of substances harmful effect. The methodical means used in determining the antimicrobial effect threshold including the recommended set of the measurable indices of intestinal microflora are discussed.

Animals↗

[Problems of the hygienic standardization of antibiotics].

Some of the results of the development of hygienic standardization of antibiotics are discussed. The main scheme proposed earlier was tested in hygienic investigation of antibiotics of various groups. Separate elements of the scheme were shown to be reliable and approaches to its further improvement were suggested. The trends of promising studies on toxicology of antibiotics aimed at their hygienic standardization are presented.

Animals↗

[Assessment of the reproductive function of white rats exposed to cephalexin by inhalation].

The embryotoxic and teratogenic effects of cefalexin were studied on Wistar albino rats subjected to inhalations of the antibiotic within the whole gravidity term. It was shown that in a concentration of 1.29 mg/m3 cefalexin did not increase the rate of fetus intrauterine death, had no unfavourable effect on the fetus and placenta development and did not induce anomalies in development of the fetus internal organs. The frequency of sensitization in the gravid and nongravid animals was the same. No signs of sensitization were detected in the litter of the rats treated with cefalexin inhalations.

Administration, Inhalation↗

[Experimental study of the effect of rifampicin on the embryogenesis of white rats].

The embryotoxic and teratogenic effects of rifampicin were studied on Wistar albino rats exposed to the antibiotic inhalations during the whole period of gravidity. It was found that in the concentrations used (6.1 +/- 0.4 and 0.81 +/- 0.08 mg/m3) the antibiotic did not induce any increase in the rate of the fetus intrauterine death or any pronounced anomaly in the fetus development. Still, at higher concentrations there was a decrease in the anthropometric characteristics of the fetus, higher incidence of hemoperitoneum and disorders in liver and renal functions of the 2-month-old progeny. The damaging effect of rifampicin on the fetus should be considered as mediated since it was observed in the presence of disorders in the mother's body (changes in liver and renal function, suppressed phagocytosis).

Animals↗

[Experimental studies to set hygienic standards for benzylpenicillin in the air of a work area].

The character and level of benzylpenicillin toxic effect was studied in accordance with the methodic instruction for performance of the experiments on toxicological estimation and hygienic norms of antibiotics in the air of working areas in production premises. It was shown that the antibiotic was of low toxicity under conditions of a single exposure, did not cumulate and had no local irritating and resorbing effect. It was shown to be an allergen. Prolonged inhalation of benzylpenicillin in a concentration of 14 mg/m3 resulted in reversible changes in the function of the kidneys and liver of the animals, their sensitization and development of pronounced dysbacteriosis of the mouth and intestine mucosa. In a concentration of 1 mg/m3 benzylpenicillin had no general toxic and sensitizing effect but induced reversible changes in the normal autoflora. This allowed the authors to consider the above concentration to be maximum with respect to the antibacterial effect. On the basis of the experiments the maximum permissible norm (MPN) of the aerosol of benzylpenicillin disintegration was recommended at the level of 0.1 mg/m3.

Air Pollutants↗

[Effect of industrial contact with penicillin on the immunological reactivity of workers].

Immunological examination of women occupied in production of penicillin revealed a decrease in the phagocytic activity of the blood neutrophiles and the bactericidal properties of the skin, an increase in the quantitative composition of the autoflora of the skin and changes in its biochemical properties. Correlation between the changes in the values of the natural non-specific immunity as dependent on the level of the contact with the antibiotic was shown.

Adult↗

[Experimental data on hygienic norms for antibiotics of the tetracycline group].

Toxicity of tetracyclines was studied experimentally on different species of laboratory animals. It was shown that tetracycline, oxytetracycline and chlortetracycline were close by their chemical structure and physico-chemical properties, as well as by the main toxicity parameters, i.e. acute toxicity, cumulative activity, skin-irritating and sensitizing effect. Under the conditions of subacute experiments the above 3 antibiotics induced evenly pronounced one direction changes in animals. The data obtained during the experiments provided recommendation of the level of 0.1 mg/m3 as the maximum allowable concentration (MAC) of oxytetracycline and chlortetracycline, i.e. the same level as the previously recommended for tetracycline.

Administration, Oral↗

[Toxicological characteristics of ampicillin].

Toxocity of ampicillin trihydrate was studied in acute and chronic experiments. It was shown that the antibiotic had low acute toxicity, did not cumulate and had no skin-irritating effect. On its inhalation in concentrations of 5 mg/m3 for 4 months, ampicillin induced allergization of albino rats, decreased their immunity. The general toxic effect of the drug was slightly pronounced. Ampicillin in a concentration of 0.1 mg/m3 induced tension of the immunological reactivity of the organism. The maximum permissible concentration (MPC) of ampicillin in the working premises equal to 0.1 mg/m3 is recommended. Mark "Allergen" is necessary.

Ampicillin↗

[State of certain indices of natural, nonspecific immunity in workers engaged in the manufacture of neomycin and monomycin].

Women occupied at various stages of neomycin and monomycin production were examined immunologically. The examination revealed insignificant changes in the phagocytic activity of the blood neutrophils, however no relation between the changes level and the level of contact with the antibiotics was observed. Changes in composition of the microflora in the deep skin layers in direction of an increase in the number of pathogenic microbes and a decrease in the bactericidal function of the skin were found in the women occupied at the final stages of the technological process, i.e. drying, packing and control.

Drug Industry↗

[Acute toxicity of aversectin C : various routes of administration and dosage forms].

The acute oral, cutaneous, and inhalation toxicity of aversectin C was studied on white unbred rats and mice. The compound was less toxic for rats than for mice, the LD50 for oral administration being 90 and 33 mg/kg, respectively. Aversectin C exhibited a maximum acute toxicity upon the inhalation in rats (LD50 = 40 mg/kg), while a minimum toxicity level was observed for the cutaneous application in rats (1700 mg/kg).

Administration, Inhalation↗