Effect of purine antagonists on the cAMP level in lymphocytes and bone marrow lymphoblasts

The effect of the purine receptor ligands N-ethylcarboxamide adenine and adenosine and of the purine antagonists mercaptopurine and azathioprine on the intracellular cAMP content in human peripheral blood lymphocytes and bone marrow lymphoblasts was studied. All preparations tested induced an increase in the cAMP level in peripheral blood lymphocytes. The selective immunosuppressive effect of adenosine antagonists may be due to their ability to modulate the activity of adenylate cyclase in lymphoid cells. Translated fromByulleten' Eksperimental'noi Biologii i Meditsiny, Vol. 119, N ^o . 3, pp. 294–296, March, 1995     

Effect of anapriline on the conductivity of the vascular bed

The effect of anapriline on the blood flow-pressure relationship is assessed for stepwise changes in the rate of perfusion of the vessels in the hind quarter of the cat body. It is demonstrated that when the synthesis of endothelium-relaxing factor is inhibited, the effect of anapriline is changed, and the augmentation of flow-dependent vasodilation is replaced by vasoconstriction, which increases with the increase in the blood flow through the vessel. Translated fromByulleten' Eksperimental'noi Biologii i Meditsiny, Vol. 119, N ^o 5 pp. 510–512, May, 1995 Presented by B. I. Tkachenko, Member of the Russian Academy of Medical Sciences     

Stimulation of peritoneal macrophage activity in rats with experimental peritonitis during transfusion of UV-irradiated blood

Three transfusions of blood irradiated at 254 nm induce an increase of phagocytic activity of peritoneal macrophages in rats with peritonitis in comparison with infusion of intact blood. Addition of aspirin, an inhibitor of enzymatic peroxidation of lipids, to the irradiated portion of the blood before irradiation abolishes this stimulating effect. Translated fromByulleten' Eksperimental'noi Biologii i Meditsiny, Vol. 117, N ^o 2, pp. 140–142, February, 1994 Presented by Yu. A. Vladimirov, Member of the Russian Academy of Medical Sciences     

Kynurenic acid inhibition of an experimental epileptogenic focus in the rat hippocampus

Kynurenic acid introduced in an epileptogenic focus through an electrochemotrode before the creation of the focus was found to reduce the intensity of epileptiform discharges between seizures and of electrographic correlates of seizures on the electroencephalogram. Administration of kynurenic acid led to the appearance of a slow Θ-rhythm dominating in all the leads. Translated fromByulleten' Eksperimental'noi Biologii i Meditsiny, Vol. 119, N ^o 5, pp. 521–522, May, 1995 Presented by S. N. Golikov, Member of the Russian Academy of Medical Sciences     

Enhancement of liver cell proliferation by GM3 ganglioside

In experiments on rats subjected to partial hepatectomy and experimentally induced hepatitis it is shown that GM₃ ganglioside of equine erythrocytes can enhance liver cell proliferation. The effect was also observed in experiments on a primary hepatocyte culturein vitro; moreover, enhancement of cell proliferation did not depend on the type of sialic acid residues. Translated fromByulleten' Eksperimental'noi Biologii i Meditsiny, Vol. 119, N ^o 4, pp 427–430, April, 1995     

Induction of the monooxygenase system in rat blood neutrophils by methylcholanthrene and sovolin vivo and its effects on the properties of these cells

The xenobiotics methylcholanthrene and sovol (the latter being a mixture of polychlorinated biphenyls), which are monooxygenase system inducers, were tested for their effect on the respiratory burst in rat blood neutrophilsin vivo. The chemiluminescence accompanying this burst was more intensive in the neutrophils of rats treated with methylcholanthrene or sovol than in untreated rats. Observed changes in the 2A_max parameter of the electron paramagnetic resonance spectrum recorded for the spin probe 5-doxyl stearate in the presence of neutrophils indicated that methylcholanthrene and sovol can exert a direct effect on the viscous properties of neutrophil plasma membranesin vivo. These changes were similar in direction to those in the intensity of chemiluminescence during the respiratory burst in neutrophils. Translated fromByulleten' Eksperimental'noi Biologii i Meditsiny, Vol. 120, N ^o 11, pp. 485–488, November, 1995 Presented by I. P. Ashmarin, Member of the Russian Academy of Medical Sciences     

Effect of Prooxidants on the survival of rabbits exposed toStaphylococcus aureus toxic shock exotoxin and on the chemiluminescence of their whole blood cellsin vivo

The prooxidant Adriablastin (Adriamycin) is shown to prolong the survival of Chinchilla rabbits exposed to the toxic shock exotoxin produced byStaphylococcus aureus as well as to exert a marked effect on the time course of both spontaneous and opsonized zymosan-stimulated chemiluminescence by whole blood cells of these animals. Translated fromByulleten' Eksperimental'noi Biologii i Meditsiny, Vol. 120, N ^o 9, pp. 258–259, September, 1995 (Presented by Yu. A. Vladimirov, Member of the Russian Academy of Medical Sciences)     

Effect of aminooxyacetic acid on the antidote activity of diazepam under the action of GABA-lytics

Pretreatment of mice with aminooxyacetic acid enhances the antidote activity of diazepam against picrotoxin but not bicuculline. It is claimed that GABA-transaminase inhibitors may be promising candidates as an antidote in complex therapy of seizures induced by GABA-lytics blocking the chloride ionophore. Translated fromByulleten' Eksperimental'noi Biologii i Meditsiny, Vol. 117, N ^o 4, pp. 441–443, April, 1994     

Role of the specific determinant of group A streptococcus polysaccharide in inhibition of T-suppressor activity

Group A streptococcus polysaccharide is found to inhibit the activity of ConA-stimulated T suppressors. A-variant streptococcus polysaccharide, representing an L-rhamnose homopolymer which is identical to the rhamnose carcass of group A streptococcus polysaccharide, does not possess such an effect. The effect of group A streptococcus polysaccharide on the activity of T suppressors is considered to be associated with its determinant including N-acetylglucosamine as an obligatory component. Translated fromByulleten' Eksperimental'noi Biologii i Meditsiny, Vol. 119, N ^o 2, pp. 201–203, February, 1995 Presented by S. V. Prozorovskii, Member of the Russian Academy of Medical Sciences     

Effects of hydrocortisone,retabolil, and their combination on the phagocytic activity of rat blood neutrophils

Effects of retabolil on the phagocytic index, phagocytic number, and the nitro blue tetrazolium reduction test with rat blood neutrophils were studied. The drug was found to reduce these parameters. Pretreatment with retabolil arrested or attenuated the depression of neutrophil phagocytic activity caused by hydrocortisone. Translated fromByulleten' Eksperimental'noi Biologii i Meditsiny, Vol. 119, N ^o 2, pp. 179–180, February, 1995     

Effect of isobutyl ester of retinoic acid on the cellular composition of bronchoalveolar lavage and on the mitotic activity of alveolar monocyte-macrophages in rats

Different doses of the isobutyl ester of retinoic acid were administered intraperitoneally into rats for two weeks. The dose of 1 mg/kg caused a significant increase in the mitotic activity of cells of the macrophagal series in alveoli; an anti-inflammatory effect was observed at a dose of 10 mg/kg. The isobutyl ester of retinoic acid did not affect the cell ratio (alveolar macrophages, lymphocytes, neutrophils, eosinophils) in the internal medium of the lungs. Translated fromByulleten' Eksperimental'noi Biologii i Meditsiny, Vol. 118, N ^o 12, pp. 645–647, December, 1994 Presented by N. K. Permyakov, Member of the Russian Academy of Medical Sciences     

Effect of nimodipine on the circulation in the midbrain and carotid arteries of rats

It is found that nimodipine induces biphasic changes in the circulation in the midbrain artery: an initial slight and transient reduction gives way to a considerable and long-term increase of the circulation. Nimodipine also boosts the circulation in the common and internal carotid arteries, which coincides in time with, but is shorter than, the first phase of changes in the hemodynamics in the midbrain artery. The findings are not consistent with the common view on the selectivity of the cerebrovascular effect of nimodipine. Translated fromByulleten' Eksperimental'noi Biologii i Meditsiny, Vol. 118, N ^o 10, pp. 410–413, October, 1994 Presented by M. D. Mashkovskii, Member of the Russian Academy of Medical Sciences     

Seasonal differences in the development of heightened resistance of the isolated heart during adaptation to physical exercise

Substantial seasonal differences are found in the development of the cardioprotective effect of adaptation to physical exercise: in winter such adaptation results in an increase of the resistance of the isolated heart to the contracture and arrhythmogenic effects of ischemia and reperfusion, while in summer the anticontracture effect is absent and the antiarrythmic effect is significantly lowered. Translated fromByulleten' Eksperimental'noi Biologii i Meditsiny, Vol. 120, N ^o 9, pp. 299–301, September, 1995 Presented by G. N. Kryzhanovskii, Member of the Russian Academy of Medical Sciences     

Effect of some cholinergic substances on spontaneous immunoglobulin E production by mononuclear cells of the peripheral blood in hay fever patients

The effect of carbachol, forskolin, and cycloheximide on IgE biosynthesis is studied in hay fever patients. The effect of carbachol is noted only for significant synthesis of IgEde novo. The administration of forskolin causes the inhibition of both IgE and IgG spontaneous production, while subsequent administration of carbachol neutralizes this effect. Whende novo IgE synthesis is absent, the degradation of IgE in the culture of peripheral blood mononuclear cells decreases significantly in the presence of cycloheximide. Translated fromByulleten' Eksperimental'noi Biologii i Meditsiny, Vol. 117, N ^o 5, pp. 508–509, May, 1994     

Effect of toxic substances of diphtheria corynebacteria on aggregation of human platelets

The effect of the toxic substances of diphtheria corynebacteria (diphtheria toxin, diphtheria anatoxin, and codivac) on the aggregation of human plateletsin vitro was demonstrated using platelet-rich plasma prepared from citrated blood and the standard platelet activator ADP (2×10⁻⁵ M). These substances induce platelet aggregation in a dose-dependent manner. Incubation of diphtheria toxin and anatoxin with platelets reduces ADP-induced and total platelet aggregation, the effect being dependent on the inducer dose and incubation time. By contrast, codivac stimulates ADP-induced and total platelet aggregation in all experimental series. Translated fromByulleten' Eksperimental'noi Biologii i Meditsiny, Vol. 118, N ^o 12, pp 623–625, December, 1994 Presented by V. I. Pokrovskii, Member of the Russian Academy of Medical Sciences     

Anti-ischemic effect of a new oxynicotinic acid derivative

The effect of a new derivative of oxynicotinic acid (KONA) on experimental cerebral ischemia is examined in rats. It is demonstrated that a single dose of the preparation (30 mg/kg) significantly decreases the severity of ischemic damage and increases the survival of the animals after bilateral ligation of the common carotid arteries. Comparison with xanthinol-nicotinate shows the advantages of the new preparation. Although KONA does not inhibit free-radical oxidationin vitro, it does lower the content of free-radical oxidation products in rat blood plasma to the normal level. Translated fromByulleten' Eksperimental'noi Biologii i Meditsiny, Vol. 118, N ^o 7, pp. 49–51, July, 1994 Presented by I. P. Ashmarin, Member of the Russian Academy of Medical Sciences     

Prophylactic and corrective action of the polyethylene oxide polyox WSR-301 in rats with experimental lipoidosis

Two once-weekly intravenous injections of the polyethylene oxide Polyox WSR-301 (yielding a blood concentration of the order of 5×10⁻⁶ g/ml) led to a 38% decrease in the area occupied by sudanophilic lesions in the aortic arch of rats fed an atherogenic diet for two weeks. Perfusion under constant pressure of the formalin-fixed vascular system in the posterior part of the body with physiological saline and then with polyethylene oxide (10⁻⁵ g/ml) was without effect in normal rats and in those with mild lipoidosis, but reduced hydrodynamic vascular resistance by 9–14.5% in rats with pronounced lipoidosis. Intravenous injection of polyethylene oxide into anesthetized rats with pronounced lipoidosis in doses that were subthreshold for normal rats (blood concentrations of the polymer were of the order of 10⁻⁷ g/ml) caused a 20% decrease in the total peripheral resistance to blood flow, with a 17–20% rise of the blood flow rate in the carotid artery. Translated fromByulleten' Eksperimental'noi Biologii i Meditsiny, Vol. 119, N ^o 6, pp. 587–589, June, 1995 Presented by I. P. Ashmarin, Member of the Russian Academy of Medical Sciences     

Effect of dexamethasone on the expression of binding sites for high-density lipoproteins in cultured rat hepatocytes (Independence of the hormone effect on the intracellular cholesterol pool)

It is shown that glucocorticoids play a key regulatory role directed toward the maintenance of an optimal level of binding and internalization of HDL₃ in hepatocytes. Their stimulatory effect on the expression of HDL receptors proves to be independent of changes in the CH content in parenchymal cells. Translated fromByulleten' Eksperimentalnoi Biologii i Meditsiny, Vol. 117, N ^o 1, pp. 50–53, January, 1994     

Proton NMR relaxation of the nonaqueous component of human blood serum

Proton magnetic resonance relaxation was experimentally studied in native blood serum in groups of healthy subjects and patients with malignant tumors. Although the longitudinal relaxation timeT ₁ of the aqueous component in these groups was found to differ reliably, the longitudinal relaxation time of nonexchanging or slowly exchanging protons in these samples within the attained range of accuracy was virtually the same. Moreover, it was revealed that the amplitude of the “nonaqueous component” of blood serum correlates with the protein concentration in the samples. Translated fromByulleten' Eksperimental'noi Biologii i Meditsiny, Vol. 120, N ^o 10, pp. 445–448, October, 1995     

Use of glutathione inhibitors and glutathione transferases to overcome tumor resistance to cytostaticsin vivo

Preincubation of cells of BDF1 hybrid mice with P388 leukemia with doxorubicin and buthionine sulfoximine leads to the manifestation of a therapeutic effect of the antibiotic. Injection of buthionine sulfoximine and ethacrinic acid to mice with leukemia does not alter the therapeutic effect of the antibiotic. Translated fromByulleten' Eksperimental'noi Biologii i Meditsiny, Vol. 119, N ^o 2, pp. 212–214, February, 1995 Presented by N. N. Trapeznikov, Member of the Russian Academy of Medical Sciences