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Biomedical subjects

B Trifonov

Publications and source records attributed to B Trifonov.

6 recordsLinked to original sources
PubMed1999

In vivo testing of Enterogenin for a mutagenic activity of bone marrow hemopoietic tissue of mice.

The purpose of the present study was to test Enterogenin for genotoxicity. The micronuclearic test of Schmid W. was used. Enterogenin was introduced intraperitoneally, once and/or twice in two doses on male and female mice of the BDF 1 hybrid line. The positive controls were injected with clastogenic agent. Bone marrow smear preparations were made, determining the ratio between the normochromic erythrocytes (NCE) and polychromic erythrocytes (PCE), and the number of micronuclearic erythrocytes (MNE). Enterogenin has no genotoxic effect on the hemopoietic tissue of bone marrow of mice the ratio NCE/PCE being within the reference values. The preparation showed no clastogenic effect (p > 0.05), compared to the controls, as the number of PCE with micronuclei did not change 24, 48 and 72 hours after treatment with the two studied doses.

Adenosine Monophosphate↗
PubMed1993

Altered levels of phosphatidylinositol phospholipase C activity in rat liver cells in response to insulin, epinephrine, acetylcholine and bacterial phospholipase C.

Rat liver cells were homogenized and subsequently fractionated by a simplified method based on microfiltration, which proved to give a high recovery of membrane-bound phosphatidylinositol phospholipase C (PI-PLC) activity. The effects of insulin, acetylcholine (AC), epinephrine (EN) and bacterial phospholipase C (bPLC) on the PI-PLC activity were studied after in vitro treatment of isolated membranes or after in situ application in rat liver. A dose-dependent increase of membranous PI-PLC (up to 3-fold) and corresponding 36 to 72% decline of the cytosolic activity were established upon treatment with supraphysiological doses of insulin or with bPLC, respectively. AC induced a biphasic response with a maximal stimulation in the micromolar range. On the other hand EN promoted a slight but significant dose-dependent inhibition of PI-PLC in both cytosol and membranes. Sodium fluoride was also a potent inhibitor of the membrane-associated PI-PLC with an EC50 value of about 5 mM. The combined assay with NaF and EN revealed no additivity between their inhibitory effects, suggesting a common step in the mechanism(s) of inhibition caused by the two agents. The stimulatory effects of insulin and AC were partially reduced by soluble cytosolic factors, which still remain to be identified. When insulin and AC were applied in combination in the presence of cytosol, this resulted in a 56% inhibition of PI-PLC below the control level.

Acetylcholine↗
PubMed1992

Effect of phosphatidylinositol-specific phospholipase C from Bacillus thuringiensis on solid spinocellular carcinoma.

Phosphatidylinositol-specific phospholipase C (PIPLC) from Bacillus thuringiensis (0.11 units per ml) inhibited growth of IC-Sofia carcinoma cell line in culture by 64%. The growth of transplanted carcinoma in hamsters was also inhibited by 29% at a dose of 4.9 units of PIPLC/kg animal/day. In addition, degeneration processes and a significant fibrosis of the tumour occurred. The functional, clinical, biochemical and haematological parameters studied were consistent with the established antitumour effect in vivo.

Animals↗
PubMed1985

Determination of certain physical and chemical characteristics of the activating serum factor from preparturient women and women with habitual abortions.

Follow-up investigation of the blood sera from preparturient women and women with habitual abortions showed the presence of a factor which has an activating effect on smooth muscle preparations because it causes the release of prostaglandins. Gel-chromatographic counter flow separation and microelectrophoresis of the blood sera have shown that the isolated serum factor is a water soluble glycopeptide with a molecular weight of about 2000.

Abortion, Habitual↗