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Biomedical subjects

M Miko

Publications and source records attributed to M Miko.

At least 37 records · Page 2Linked to original sources
PubMed1989

Cytolytic activities of benfluron metabolites and loss of transplantability.

The cytolytic activity of two benfluron metabolites, namely 7-dihydrobenfluron (DBF) and benfluron N-oxide (NOBF), has been studied using both Ehrlich ascites carcinoma (EAC) and P388 leukaemia cells. DBF showed a considerable cytolytic activity (activity of lactate and malate dehydrogenases, release of protein from the cells into the culture medium, morphological changes) particularly at higher concentrations. The highest concentrations caused a significant prolongation of the survival time of the experimental animals.

Animals↗
PubMed1989

Substances with antineoplastic activity. XCVI. Some pharmacological properties and therapeutic synergism of 6-purinyl-N-(2-chloroethyl)thiocarbamate with cytosine arabinoside.

The cancerostatic effect of 6-purinyl-N-(2-chloroethyl)thiocarbamate (Cloturin VUFB, VUFB-15686) was studied in detail in mice and rats bearing transplantable tumors. The cytotoxic activities were measured by determining the incorporation rate of 5-iodo-2'-deoxy[6-3H]uridine and uniformly labeled [U-14C]amino acid mixture into trichloroacetic acid-insoluble fraction of Yoshida ascites reticulosarcoma cells during a short-term incubation with the drug. From the results obtained it follows that the new substance is therapeutically more effective in comparison with 6-mercaptopurine (NSC-755). A therapeutic synergism of Cloturin with cytosine arabinoside (NSC-63978) was observed.

Animals↗
PubMed1989

Primary screening and inhibition of macromolecular biosynthesis by benfluron metabolites in vitro.

Cytotoxicity and mechanisms of action of 2 metabolites of benfluron (BF), namely 7-dihydrobenfluron (DBF) and benfluron N-oxide (NOBF) were tested. Cytotoxicity in the primary biochemical screening was measured by the inhibition of 14C-adenine and 14C-valine incorporation into the TCA-insoluble fraction of Ehrlich ascites carcinoma (EAC) cells under defined in vitro conditions. Both metabolites were found to have cytotoxic effects, with NOBF being more active than DBF. Further we investigated the kinetics of incorporation not only of adenine and valine, but also of 14C-thymidine and 14C-uridine both into Ehrlich carcinoma cells and into P388 leukemia cells.

Animals↗
PubMed1989

Effects of benfluron metabolites on glycolysis and level of thiol groups in P388 and Ehrlich ascites cells.

The effects of two benfluron metabolites, namely 7-dihydrobenfluron (DBF) and N-oxide of benfluron (NOBF), on the aerobic glycolysis of Ehrlich ascites carcinoma (EAC) and P388 cells were studied. Also their effect on the level of total (T-SH) and nonprotein (NP-SH) thiol groups was investigated. A significant inhibition of aerobic glycolysis in the presence of NOBF was found only in P388 cells. Both metabolites decreased more significantly the level of NP-SH than that of T-SH.

Aerobiosis↗
PubMed1989

Effect of benfluron metabolites on ATP level in tumor cells.

Changes in ATP levels of both Ehrlich ascites carcinoma and P388 leukemia cells were evaluated after 2 h of incubation in the presence of different concentrations of benfluron (BF), 7-dihydrobenfluron (DBF) and N-oxide of benfluron (NOBF). Up to the concentration of 37.5 mumol/l, none of the substances significantly depressed the ATP levels. A more expressive decrease in ATP levels was noted only at concentrations of 75 mumol/l and higher. BF proved the most effective, less effective was DBF, while NOBF was practically without any effect. Of the remaining cytostatic drugs, Mitoxantrone, CCNU and Me-CCNU, in particular, proved efficient in depressing ATP level. The latter becomes depressed already after 15 min of incubation in the presence of the highest concentrations of benfluron and 7-dihydrobenfluron.

Adenosine Triphosphate↗
PubMed1988

Inhibition of biosynthetic processes in P388 and Ehrlich ascites cells by cloturin.

The effect of cloturin on biosynthesis of DNA, RNA and proteins in both P388 and Ehrlich ascites carcinoma (EAC) cells have been studied in vitro. Biosynthesis of macromolecules indicated by the incorporation rate of [14C]adenine (DNA, RNA), [14C]thymidine (DNA), [14C]uridine (RNA) and [14C]valine (proteins) were studied for concentration (75 to 600 mumol/l) and time dependence. Cloturin inhibits incorporation of all 14C-precursors into the TCA-insoluble fraction of both types of cells in proportion to its concentration. The complete inhibition of 14C-precursors was reached at the highest concentrations of cloturin (300 and 600 mumol/l). The fact that incorporation of four precursors is inhibited suggests that the effect of cloturin lies at an underlying level of energy generation or transfer, rather than at specific reactions in the biosynthesis of DNA and proteins. The rate of DNA synthesis is rapidly affected by the lowering of the level of any of the four deoxyribonucleotide triphosphates. Interference with the generation of high-energy phosphate bonds is one of the mechanisms available for induction of nucleotide deficiency. A depletion of nucleotide pools can serve as an efficient tool to inhibit cellular growth and to induce cell death under some circumstances.

Adenine↗
PubMed1982

The effect of rifampicin on Mycobacterium smegmatis.

Rifampicin was found to inhibit the growth and incorporation of 14C-adenine, 14C-leucine and 14C-glycine in exponentially growing cells of M. smegmatic cultivated in Merrill's synthetic medium. Increasing concentrations of the antibiotic inhibited respiration in resting cells, in the presence of glucose or 2-oxoglutarate as substrates in particular. In addition to the well-known interference of rifampicin with the biosynthesis of RNA, the effect on the energy metabolism should also be considered.

Adenine↗
PubMed1980

Effect of 2,3-dinitrilo-1,4-dithia-9,10-anthraquinone on Mycobacterium smegmatis.

2,3-Dinitrilo-1,4-dithia-9,10-anthraquinone (DDA) is an effective inhibitor of respiration of intact cells of Mycobacterium smegmatis in the presence of glucose, glycerol, pyruvate, acetate and other citric acid cycle intermediates or substrates associated with this cyclic (glutamate, asparagine). DDA inhibits the incorporation of both 14C-leucine and 14C-adenine into appropriate macromolecules of M. smegmatis (TCA-precipitable fractions), and causes a drop in the incorporated activity of U-14C-glycine or its degradation products in all the cell fractions studied (lipids, RNA, DNA, proteins). DDA suppresses the growth of M. smegmatis probably through an interference with the cell energy-carbon metabolism.

Acetates↗