[Morphological changes in the rat uterine tissues exposed to pregna-D'-pentaran derivatives of progestins and anti-progestins]. / Morfologicheskie izmeneniia tkanei matki krysy pod vliianiem progestinov i antiprogestinov riada pregna-D'-pentarana.

Changes in the uterus morphology of mature female rats were studied on the model of pseudopregnancy after treatment with the progestin 16 alpha,17 alpha-cyclohexanoprogesterone (PR) and the antirpogestins 5 alpha(H)-16 alpha,17 alpha-cyclohexano-4,5-dihydroprogesterone (APR1) and 5 beta(H)-16 alpha,17 alpha-cyclohexano-4,5-dihydroprogesterone (APR2). The rats were preliminarily estrogenized with 17 beta-estradiol at a dose of 1 microgram/(animal day) for 4 days and then treated with PR at a dose of 0.2 mg/(animal day) for 14 days. The first group was then left without any treatment, whereas APR1 and APR2 were injected at the dose of 0.2 mg/(animal day) for 4 days to the animals of the second and the third groups, respectively. Light and electron microscopy of the uterus preparations demonstrated that the PR action provoked a complete pseudopregnancy picture characterized by the endometrium functionalization and the myometrium hypertrophy. Subsequent treatment with APR1 and APR2 caused the hypertrophy to cease, which had a more pronounced effect in the case of APR1. At the same time, some indications of the endometrium functionalization remained observable after treatment with APR1 and APR2. The specific binding sites for 3H-labeled APR1 and APR2 were absent from the uterus cytosol for the rats gestagenized with PR.

[New transplantable brain gliomas in rats]. / Novye perevivaemye gliomy golovnogo mozga krys.

The paper provides the characteristics of 11 original transplanted rat brain gliomas that are part of the collection of experimental tumors of the nervous system, which has been developed at the Institute of Human Morphology, Russian Academy of Medical Sciences. The biological features of brain tumour strains, methods of their transplantation and cryoconservation are outlined in the paper.

[Biological bases of neuro-oncology]. / Biologicheskie osnovy neiroonkologii.

The paper discusses the current status of the problem in brain tumor biotherapy. It provides strong evidence for potentialities of hormonal therapy and presents current experimental findings of the application of other brain tumor biotherapies: immune (vector and adaptive), genic and differential.

[The distribution of glial fibrillary acidic protein and protein S-100 in experimental brain tumors in rats]. / Raspredelenie glial'nogo fibrilliarnogo kislogo belka i belka S-100 v éksperimental'nykh opukholiakh mozga krys.

The methods of quantitative immunoelectrophoresis and indirect immunofluorescence were used study the content of glial fibrillary acid protein in 10 serially reinoculated rat gliomas induced primarily by ethylnitrosourea (a total of 135 tumors). It was found that the GFAP content reduced with increase of malignancy. However, wide scattering of the GFAP content in some of the tumors was characteristic of all strains. In the group of slowly growing glial tumors (2 malignant astrocytomas and one malignant oligoastrocytoma) the GFAP content ranged from 50 to 600% and exceeded the normal content two-to threefold on the average. In the group of highly malignant gliomas (4 malignant ependymomas, 2 malignant gliomas, and one glioblastoma) the GFAP content was within the limits of 65-120%. In most cases the GFAP level was below normal or could not be determined at all. At the same time, tumors with a high GFAP content were encountered. The GFAP-positive cells were unevenly distributed in the gliomas: separately, in foci, and around the vessels. Their number increased in the direction of the periphery of the tumor. Intensive fluorescence was noted on the tumor--brain borderline. The content of protein S-100 in the experimental gliomas was always below normal.

[Some quantitative parameters of the vascular system of transplanted brain tumors in experiments using rats]. / Nekotorye kolichestvennye parametry sosudistoi seti perevivaemykh opukholei golovnogo mozga v éksperimente na krysakh.

A vascular system of several strains of brain tumors: neurinoma 46-1, gliomas: 11-9-2 and 101-8 were investigated by means of automatic analysis of microangiograms and histochemical-luminescent estimation of endothelial cells. It was shown that the mean quantity of vessels and their section-size in all strains of tumors are less than control independently of the rates of tumor development. The linear density of the endothelial cells appear less that in control vessels and is equal in different strains of tumors, though the inclination to hemorrhages in gliomas is higher than in neurinoma. The cause of this phenomenon is discussed.

[Antibodies to glial fibrillary antigen as potential carriers of drugs for glial tumors]. / Antitela k glial'nomu fibrilliarnomu antigenu kak potentsial'nye perenoschiki lekarstvennykh sredstv k glial'nym opukholiam.

Polyclonal monospecific antibodies to the glial fibrillar antigen of the brain (GFA) and, as controls, antibodies not possessing specific tendency were injected intravenously separately into two groups of rats with glioblastomas transplanted into the brain. The immunoenzymatic method was used to study the content of the injected antibodies in tissue extracts collected from the zone of the glioblastoma, brain matter and other organs 2, 20, and 48 hours after the injection. It was established that polyclonal monospecific antibodies to GFA accumulate selectively in the zone of the glioblastoma. The use of antibodies to GFA for selective transport of medicinal agents to malignant glial tumors must be evaluated in further studies.

[A new cell line of rat gasserian ganglion neurinoma NGUK-1]. / Novaia kletochnaia liniia nevrinomy gasserova uzla krysy NGUK-1.

A new cell line has been derived from the rat gasserian ganglion neurinoma NGUK-1 induced by transplacental administration of ethylnitrosourea. It is characterized by an astrocyte-like growth pattern at the low cell density, and by an epitheliocyte-like pattern in the confluent monolayer. The cell line displays a high proliferative activity, its maximum mitotic index and proliferative pool being--2.5 and 96%, respectively. The chromosome number ranges between 20 to 100. The chromosome modal number is 39--44. The new cell line has been used for the express diagnostic of rabies, for determination of serum glial toxicity in neurologic patients, and interferon titration.

[Comparative study of the activity of arginase isoenzymes in brain tumors of humans and experimental animals]. / Sravnitel'noe izuchenie aktivnosti izoform arginazy opukholei golovnogo mozga cheloveka i éksperimental'nykh zhivotnykh.

Isoenzyme spectrum and total activity of arginase were studied in rat brain during growth of transplanted neurinoma and glioma as well as in malignant tissues of human brain. After transplantation of the tumors two peaks of arginase activation were observed within 2-4 days in rat brain tissues and within 16 days in tumoral tissue. Positively charged isoenzyme I of arginase was mainly activated but activity of neutral isoenzyme II was unaltered or slightly decreased. In human brain tumors activity of isoenzyme I was also prevailed, while activity of isoenzyme II was increased in some cases. Regulation of the arginase activity appears to occur by a complex mechanism and the enzyme plays a key role in development of nervous tissue neoplasms.

[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.

[Brain arginase isoenzyme activity during the growth of neurinomas]. / Aktivnost' izoform arginazy mozga v period rosta nevrinomy.

Activity of arginase and of its isoenzymes was studied in rat brain tissue and in neurinoma tissue (strain 10-13-3) at the period of growth of the tumor in trigeminal nerve. Within the fourth day after the tumor transplantation the total activity of arginase was increased in brain and distinct alterations were found in the isoenzyme spectrum, mainly in the impaired hemisphere. The enzymatic activity was increased in the tumoral tissue within 16 days; the activation was localized in the malignant tissue and did not extent into surrounding nerves. In all the samples studied the positively charged isoenzyme I was activated, whereas the activity of the isoenzyme II was altered only slightly and usually tended to decrease. It was the activity of the isoenzyme I, which appeared to be altered in the growing tumor.

[Changes in arginase activity during neurinoma growth]. / Izmenenie aktivnosti arginazy v protsesse rosta nevrinomy.

Arginase activity was studied in the brain and other tissues of the rat at the different periods of neurinoma growth. The activity of the enzyme was considerably activated in the affected hemisphere on the 4th day, in the skin of the head and thigh on the 6th day after tumor transplantation. Elevation in arginase activity in the neoplasm itself was recorded on the 16th day. The data obtained point to the physiological significance of arginase during neurinoma growth.

[Concentration of lactate concentration in experimental glial tumors and brain tissue during brief artificial hyperglycemia]. / Soderzhanie laktata v glial'nykh opukholiakh i mozgovoi tkani v éksperimente pri iskusstvennoi kratkovremennoi giperglikemii.

The authors studied the content of lactic acid in glial tumors of the brain and brain tissue of rats in short-term artificial hyperglycemia. In short-term artificial glycemia the lactic acid content in glial tumors of animals was almost twice the level of this metabolite in the brain tissue, which is due to the high potential rate of glucose consumption by the tumor and the increased glycolytic activity in it in these conditions. The lactate content in the glial brain tumors significantly increases when the sugar concentration in the blood of animals is artificially increased. It is suggested that accumulation of lactic acid in brain gliomas of experimental animals contributes to diminution of tumor cell viability, which will increase sensitivity of the tumor to irradiation.

[Concentration of glucose in the tissues of glial tumors of the brain in rats with artificial hyperglycemia of short duration]. / Soderzhanie gliukozy v tkaniakh glial'nykh opukholei golovnogo mozga krys pri iskusstvennoi kratkovremennoi giperglikemii.

The glucose content in the tissues of rat brain glial tumors and in the brain tissue during short-term induced hyperglycemia was studied. It was shown that in artificial increase of the concentration of glucose in blood, its content in the tumor grows sharply and exceeds considerably the level of this metabolite in the brain tissue. In distinction from the brain tissue, the tumor was marked by a high rate of glucose consumption and utilization under these conditions. It is concluded that brain glial tumors are also capable of increasing glucose consumption in artificial hyperglycemia. It is suggested the the accumulation of glucose by the tumor creates the preconditions for improving the efficacy of radiotherapy combined with short-term artificial hyperglycemia in the management of brain glial tumors.

[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.

[New cell line of mouse ependymoblastoma]. / Novaia kletochnaia liniia épendoblastomy myshi.

A new cell line derived from transplanted mouse ependimoblastoma consists of typical fibroblast-like cells with well-defined pleomorphism. The line is characterized by a rapid increase and decrease of proliferative activity, by a short stationary phase and early degeneration. The average time of themitotic cycle was determined as being 22-24, tG1-11-12, ts-8-9, tG2-3 and tM-near 0.9 hours. The cytophotometrical evaluation of DNA content revealed two cell subpopulations with different ploidy, both in culture and in tumor in vivo. As compared to the original tumor cells, the cultured cells differ in wider variability of DNA content and a higher average ploidy per nucleus.