[Hygienic aspects of the production of asbestos substitutes]. / Gigienicheskie aspekty proizvodstva zamenitelei asbesta.

Due to the high level aggressiveness of asbestos, more attempts have been made in the recent years to replace asbestos by other artificial mineral fibres. In this connection, the labour conditions were studied in the basalt and carbon fibres processing sites. The major occupational hazards of these sites included basalt and carbon fibres dusts, heating microclimate in some working zones and physical overload. An intratracheal experiment revealed a lower degree of fibrinogenicity of the basalt and carbon fibres as compared to chrysotile asbestos. The number of the induced mesothelioma in the intraperitoneal introduction of basalt and carbon fibres was markedly lower than in case with chrysotile asbestos. Hygienically, asbestos should be replaced wherever possible, and the dust control measures should by no means be inferior to those with asbestos.

[Induction of stomach cancer by the chronic action of arsenic]. / Induktsiia raka zheludka pri khronicheskom deistvii mysh'iaka.

Out of 18 albino rats which survived 17-24 months after implantation in a partially isolated glandular stomach compartment of a perforated polyethylene capsule containing 8 mg arsenic trioxide in a fat-wax mixture as vehicle, two developed muconodular adenocarcinoma and one--mucoid cystic adenocarcinoma in that gastric compartment; metastasis into the liver was detected in one animal. No malignant tumors were found in 9 rats with the same post-surgical survival time after implantation of a control capsule containing the same mixture without arsenic. Since spontaneous gastric cancers practically fail to appear in laboratory rats, nor have they ever been reported by other authors after control capsule implantation but developed in some rats after implantation of a carcinogen-containing one, the results of the present investigation may be interpreted as an experimental proof of the carcinogenicity of arsenic which was previously assumed on epidemiologic evidence.

[Development of malignant tumors in rats under the influence of nickel-containing aerosols]. / O razvitii zlokachestvennykh opukholei u krys pod vliianiem nikel'soderzhashchikh érozolei.

The authors conducted observations of 70 nonpedigree white rats, subjected to inhalation, intraperitoneal or intratracheal effect of nickel-containing dusts (feinstein, nickel monoxide) typical for nickel black production. It was found that intraperitoneal injection of feinstein dusts after 6-15 months was followed by the development of sarcomas at the site of injection (in 6 of 39 rats). Following inhalation dusting with feinstein dust in one of 5 cases squamous cell lung carcinoma without keratinization has arisen. Intracheal injection of nickel monoxide dust resulted in the development of squamous cell lung carcinoma without keratinization in one of 26 rats. In control series no tumors were found. The data obtained indicate the blastomogenic effect of dusts of nickel black production and are in keeping with the results of epidemiological studies and dictate the necessity of radical measures of the combat against dust at nickel-production plants.

[Optimal conditions for determing ATP of microbial origin]. / Optimal'nye usloviia opredeleniia ATF mikrobnogo proiskhozhdeniia.

Endogenous luminescence of the luciferin-luciferase extract from firely tails was studied in determing low concentrations of ATP. The optimum concentration of the the extract, corresponding to the minumum effect of endogenous luminescence, was found in the reaction medium. The solution of luciferin-luciferase was unstable at room temperature and upon dilution. The activity of luciferin-luciferse solutions did not change after freezing in liquid nitrogen with following thawing. The content of ATP was assayed in the cells of Sarcina flava disintegrated with ultrasound.

[Use of hydropyrite in the chemiluminescent determination of iron-porphyrin proteins]. / Primenenie gidropirita v reaktsiiakh khemiliuminestsentnogo opredeleniia zhelezoporfirinovykh belkov

Hydropyrite was found to be a suitable reagent which may be used in chemiluminescent reactions for determination of iron-porphyrin proteins.