[Effect of the antibiotic variamycin on the growth of a rabbit brain tumor]. / Vliianie antibiotika variamitsina na rost opukholi golovnogo mozga krolika.

The effect of variamycin, an antibiotic of the group of aureolic acid on development of dedifferentiated astrocytoma of the brain was studied on rabbits. The antibiotic was administered intraperitoneally in a dose of 0.1 mg/kg daily for 6 days. The interval between the 6-day courses was 7 days. The results were estimated by changes in duration of the latent period of the tumor development in comparison to those in the controls. One course of the treatment with variamycin started late after the tumor transplantation, i. e. on the 18th day, resulted in an increase in the latent period duration by 25.7 per cent. Starting of the treatment with the antibiotic on the 6th day after the tumor transplantation resulted in an increase in the latent period duration by up to 69 or 74 per cent with the use of 2 or 3 treatment courses, respectively. The histological examination revealed pronounced dystrophic changes or complete resorption of the tumor tissue due to variamycin effect.

[DNA levels in the cell nuclei of nervous system tumors induced by ethylnitrosourea]. / Soderzhanie DNK v iadrakh kletok opukholei nervnoi sistemy, indutsirovannykh étilnitrozomochevinoi.

Distribution of DNA in cells of 28 primary ethylnitrosourea-induced tumours of the rat nervous system was studied by the Feulgen cytophotometry method. Out of them 20 had paradiploid DNA quantity, 3 tumours--hypodiploid and 4--hyperdiploid content of DNA. A high heterogeneity of the DNA quantity and the absence of expressed modal class were found only in one case. No correlation is found between the DNA distribution in gliomas and the stage of their malignancy.

[Cytophotometric determination of DNA concentration in the cells of experimental brain tumors. II. Primary tumors of rat cerebellum induced by 9, 10-dimethyl-1, 2-benzanthracene]. / Tsitofotometricheskoe opredelenie soderzhaniia DNK v kletkakh éksperimental'nykh opukholei mozga. II. Pervichnye opukholi mozzhecka krys, indutsirovannye 9 10-dimetil-1, 2-benzantratsenom

The Feulgen-DNA cytophotometry was applied for studies of 31 rat cerebellum tumors induced by 9, 10-dimetyl-1,2-bensantracene. Most of these gliomas (22) were astrocytomas of different grades of malignancy. The histological diagnosis of other tumors was: glioblastoma -- 4, oligoastrocytoma -- 2, oligodendroglioma -- 1, gliosarcoma 1. The majority cells of 26 tumors had diploid or paradiploid DNA quantity, 4 tumors (1 astrocytoma, 3 dedifferentiated astroyctomas) had triploid modal classes. The tetraploid modal class and a large number of polyploid cells were found only once for glioblastoma multiforme. A supposition was made that drastic changes of ploidy could arise for the second time during the process of tumor evolution. The authors failed to show any exact differences in the ploidy of gliomas in rats with athyreosis or hyperthyreosis, and in the ploidy of somatic cells in control animals.

[Comparative study of the effect of inhibitors of monoamine oxidase and ftorafur on the growth of de-differentiated astrocytoma]. / Sravnitel'noe izuchenie deistviia ingibitorov monoaminoksidazy i ftorafura na rost dedifferentsirovannoi astrotsitomy

To evaluate the possible antitumour effect of intensified deposition of serotonin in the region of localization of the tumour caused by a pharmacological preparation studies of the effect of inhibitors of monoamine oxidase transamine and N2N2-dibenzylhydrazide of DL-malic acid on rat's cerebellum tumour de-differentiated by astrocytoma (strain No 101/12) were carried out. The effect of inhibitors of monoamine oxidase was compared with that of antiblastic preparation of phthorafur. Differences in the mechanisms of action of pharmacological agents referred to above are shown. It was established that inhibitors of monoamine oxidase administered against the background of the developing tumour caused a considerable reduction in its weight and prononced dystrophic and necrotic changes.

[DNA content in atypical gliomesenchymal elements in chemical blastomogenesis of the cerebellum in white rats]. / Soderzhanie DNK v atipichykh glio-mezenkhimal'nykh élementakh pri khimicheskom blastomogeneze mozzhechka belykh krys

A microphotometric comparative study was carried out; DNA content was determined in the atypical glio-mesenchymal elements around the villous capsule surrounding the DMBA pill, in the cells of microastrocytoma and microglioblastoma induced by DMBA. It was found that the late stages of this type of chemical blastomogenesis of the cerebellum of albino rats were characterized by the preservation of a distinct diploid modal class, excluding cases when the process coursed in the direction of malignization at the early stages of tumour progress (microglioblastoma).