Biomedical subjects
Publications and source records attributed to J Koziorowska.
Evaluation of mutagenic and genotoxic properties of Ukrain was on the basis of the Ames and micronucleus tests. Ukrain was investigated for its ability to induce morphological transformation of embryonic cells of the Syrian hamster. Under the experimental condition used in this study, Ukrain was found to be non-mutagenic and non-genotoxic, and furthermore did not induce morphological cell transformation.
The influence of vitamin E on the mutagenic activities of aflatoxin and adriamycin was studied. The results indicate that vitamin E shows antimutagenic activity towards aflatoxin B1 only when homogenized with liver tissue.
Treatment of human embryonic cell line CLV 102 with N-methyl-N'-nitro-N-nitrosoguanidine or bleomycin was used to induce DNA repair synthesis. Both the repair synthesis induced by these agents and reactivation of UV-damaged pseudorabies virus were inhibited by aphidicolin.
The capability of methotrexate, jododeoxyuridine and 5-fluorouracil to induce lambda prophage was compared when given alone or in combination. All these drugs were found to cause inducing conditions in Escherichia coli K12(lambda) cells. Combined action of jododeoxyuridine and methotrexate resulted in a pronounced increase in the number of free phages compared with that resulting the treatment either with methotrexate of jododeoxyuridine alone. Treatment with 5-fluorouracil caused inactivation of plaque forming ability in cells induced with methotrexate.
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The effect of pretreatment with L-asparaginase on the cytotoxicity of methotrexate (MTX) was studied in L5178Y murine leukemic cells and L-929 cells grown in vitro. The results were correlated with the effects of L-asparaginase on DNA synthesis. At low concentrations of the enzyme, pretreatment of cells enhanced the effect of MTX; at higher concentrations, it prevented the effect of MTX. Elimination of the MTX action was demonstrated also in L5178Y cells growing in the medium lacking L-asparagine. L-Asparagine readdition resulted in enhancement of MTX cytotoxicity. Pulse-labeling experiments demonstrated that in every case elimination of MTX action was related to a diminution of the fraction of cells in the phase of DNA synthesis. In contrast, enhancement of the effect of MTX was related to an increase in the fraction of cells in the DNA synthesis phase. A similar parallelism of effects occurred in L-929 cells when pretreatment with L-asparaginase was followed by washing the cells and culturing them in medium without the enzyme.
A relatively simple assay for determining the capability of chemicals to induce the reactivation of UV-irradiated pseudorabies virus in human embryo cells is presented. Using this assay cyclophosphamide (CP) and diethylstilbestrol (DES) were tested in the presence and in the absence of exogenous metabolizing system. N-methyl-N'-nitro-N-nitrosoguanidine (MNNG) was used for comparison. CP increased the survival of UV-irradiated pseudorabies virus exclusively in the presence of exogenous metabolizing system. In the cells pretreated with CP or MNNG the survival of the virus was dependent on time interval between host cell pretreatment and virus infection. No enhancement of virus survival was obtained in the cells pretreated with DES.
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Mutagenic activity of Ledakrin in microbial testing as well as its inductive effect on the release of free phages in lysogenic bacteria were compared with its transforming ability in human cell system. It has been found that Ledakrin is highy mutagenic both without metabolic activation and when activated in vivo. Ledakrin induces the release of free phages in E. coli K12(lambda +), but does not transform human fibroblasts in cell cuture in vitro.
Oncogenic transformation of cultured cells is considered to be analogous to the induction of tumors in animals. Two properties of transformed cells: the capacity to grow in soft agar and morphological alterations were used as a basis for quantitative studies on the transforming properties of chemicals. The majority of experiments on chemical carcinogenesis were so far performed on murine, hamster and rat cell systems. The most pertinent questions to be resolved now are connected with malignant transformation of human cells.
Vitamin B12 content has been determined in different kinds of cells grown in vitro and in the culture media. The results indicate a dependence of the vitamin levels on the growth rate and growth characteristics.