[Effect of Soviet bleomycin-bleomycetin on the body of animals in multiple parenteral administration]. / Vliianie otechestvennogo bleomitsina--bleomitsetina--na organizm zhivotnykh pri mnogokratnom parenteral'nom vvedenii.

Toxicity of bleomycetin was studied on 3 animal species (rats, rabbits and dogs). The antibiotic was administered intramuscularly and intravenously in various doses for a prolonged period of time. The death of the rats, rabbits and dogs treated with repeated lethal doses of bleomycetin was due to its toxic effect on the kidneys and probably lungs. The level of urea in the blood of the animals before death increased up to 300--400 mg %. Histological examination of the kidneys revealed the picture of glomerulonephritis. The lungs were highly plethoric and showed areas of alveolar collapse and consolidation consisting mainly of the collapsed alveolar epithelium. The liver was not affected by bleomycetin according to both the results of some functional tests and histological examination. tthe blood sugar level after bleomycetin administration was not altered significantly. The changes in the peripheral blood were not pronounced. An increased P wave, decreased R wave and deep S wave were seen on the ECG. Such deviitions may be due not only to the changes in the myocardium but also to the lung affection. When bleomycetiin was used repeatedly in nonlethal doses (1 mg/kg for rats, 1--2 mg/kg for rabbits and 0.25--0.5 mg/kg for dogs), the above changes were less pronounced or not manifested at all. No inhibitory effect on hemopoiesis is an important positive characteristics of bleomycetin, so that it compares very favourably with most other antitumor drugs.

["Typical" and "atypical" damages of the organ of hearing from the administration of streptomycin]. / "Tipichnye" i atipichnye" porazheniia organa slukha pri vvedenii streptomitsina

Two areas of the damage localization in the organs of hearing after streptomycin use were found in the experiments with guinea pigs, i.e. (1) the Corti's organ of the lower part of the basal helix, the zone of perception of the maximum frequency sounds and (2) the tympanic muscles. Administration of streptomycin subcutaneously in a daily dose of 300 mg/kg for 50 days resulted in pronounced atrophic changes in the fibres of m. tensor tympani and some atony of m. stapedius. On the basis of the histological examination of the tympanic muscles after prolonged use of streptomycin and comparison of the periods of the tonus reduction in the skeletal muscles and Preier reflex after a single administration of streptomycin in maximum tolerating doses, it was concluded that streptomycin affected the state of the tympanic muscles as a myorelaxant. The atrophic changes in the tensor as a result of prolonged streptomycin use was due to chronic atony of the muscle. The decrease in the contraction capacity of the tensor must result in loosening of the drum membrane tension, impairement of the muscle activity coordination, decreased ability for elimation of the auditory ossicle fluctuation. Increased audibility limits within middle and low frequencies and noise in the ears during prolonged treatment of patients with streptomycin may be associated with chronic atony of the tympanic muscles and mainly tensor.