Biomedical subjects
Publications and source records attributed to V V Benemanskiĭ.
The authors analyzed possible causes of encephalopathy progression in late occupational intoxication among firemen. Those causes are disordered autoregulation of cerebral vessels, oxidant and psychoemotional stress, autoimmune disorders.
The authors studied solitary and combined effects of vinyl chloride and dichloroethane in chronic (4 months) inhalation experiment using concentrations of 50 and 500 mg/m3. The experiment revealed general toxic effects including disorders of central nervous system and liver. Those disorders are caused by reductive-oxidative reactions disturbances and dystrophic processes. The authors determined safe combinations of vinyl chloride and dichloroethane concentrations for associated action.
Exposure to concentrations of vinyl chloride (VC) + dichloroethane (DCE) 50 + 50 mg/m3, VC + DCE 50 + 500 mg/m3 and VC + DCE 500 + 50 mg/m3 during pregnancy induced higher occurrence of fetal resorption, increased incidence of preimplantational and postimplantational fetal death. Carcinogenic activity of the same levels of VC and DCE was seen in various organs: high concentrations of DCE increased incidence of lung tumors, high levels of VC--of breast neoplasms, mesenterial lymphosarcoma and liver hemangiosarcoma.
The authors obtained new concepts on immune and biochemical response conditioned by character and circumstances of combined biologic and chemical agents. The article covers role of chemical technogenic pollution promoting transfer of compensated adaptation into decompensation phase with sensibilization or allergy in some cases and with toxic allergic reactions in others. The calculated values include a generalized parameter that, if changed over preset level, could be a risk criterion for the certain diseases.
In chronic experiments, albino noninbred rats were fed 20.0, 2.0 or 0.2 mg/l nitrosodimethylamine and 1000 or 100 mg/l ascorbic acid (average daily dose 100 or 10 mg/kg body weight). The study established the modifying effect of ascorbic acid on nitrosodimethylamine -- induced carcinogenesis. A decrease in tumor incidence was observed, particularly, at high level of the carcinogen. High dose ascorbic acid did not affect tumor incidence in intact animals; however, time to detection of the first tumor and mean duration of tumor development proved longer.
Albino noninbred rats were exposed to hexachlorophene (chronic inhalation of 0.1 CL50 for 12 months). The tumors detected occurred mostly in the lungs. Increased incidence of lung tumors as well as their histomorphologic pattern (not typical of spontaneous neoplasms of these animals) suggested carcinogenicity of hexachlorophene under the said conditions.
Research in factors modifying carcinogenesis is closely associated with studies on complex multifactorial systems. Mathematical methods of planning multifactorial experiments should be used which assures a higher reliability of the results and elicits additional information. An analysis of the data on the modifying effect of aniline, sodium alkylsulfate and lead nitrite on nitrosomethylamine-induced carcinogenesis carried out on the basis of the newly-developed method showed its advantages over the existing ones.
It is proved in experiments with the interrupting and twenty-four hour inhalations and peroral use of nitrosodimethylamine on the Wistar and white rats, that blastomogenic effect is submitted to the dose-effect dependence. On the whole the tumour incidence is determined by a total dose of carcinogen but its size may vary to a considerable extent depending on the regime of nitrosodimethylamine delivery. The daily and single doses of carcinogen are of great importance. Relatively high daily doses introduced within a short period of time cause a greater effect than low doses introduced within a larger period of time. The greater blastomogenic effect is caused by a longer peroral introduction of the same daily dose.
A pronounced carcinogenic action was detected after ten-fold application of nitrosodimethylamine in 3 doses (calculated doses equal 10.0; 5.0; 1.0 mg per rat). The tumour incidence in groups is equal to 93.3%, 20.0%, 6.6% and 3.3% (in control). No morphological changes were found in the place of application. Induced tumours localized in the liver, lungs and kidneys.
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The round-the clock inhalation of the mixture of nitrosodimethylamine (NDMA), dimethylamine (DMA) and nitrogen dioxide, with NDMA concentrations varying within 0.66-0.0026 mg/m3, was followed by development of tumors in the kidney, liver, lungs and at other sites in albino nonbred rats, after a year of exposure. Application of DMA and nitrogen dioxide modified the carcinogenic effect of NDMA. In male rats, the blastogenic effect of the mixture was higher, as compared with that of inhalation of NDMA alone. NDMA inhalation resulted in a lower tumor yield in female rats.
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In experiments on Balb/c mice and Wistar rats the authors have studied the carcinogenic activity of nitrosodimethylamine (NDMA) in daily inhalations of the drug in concentrations of 0.005 mg/m3 and 0.2 mg/m3 during 17 months for mice and 25 months for rats. In the concentration of 0.2 mg/m3 tumors would arise considerably earlier and in larger amounts than in control animals, as well as in animals inhaling NDMA in the concentration of 0.005 mg/m3 and not differing in this respect from control animals.
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