Modulation of the oxidative burst in mouse macrophages and human neutrophils by superlow concentrations of GM1 ganglioside

It is shown that ganglioside GM1 in picomolar concentrations stimulates the phorbol-12-myristate-13-acetate (PMA)-induced generation of active forms of oxygen by neutrophils and peritoneal macrophages. GM1 (10⁻¹¹ M) is found to enhance the luminol-dependent chemiluminescence induced by 10⁻⁸ M PMA in mouse macrophages in comparison with the effect of PMA alone. Translated fromByulleten' Eksperimental'noi Biologii i Meditsiny, Vol. 117, N ^o 1, pp. 44–46, January, 1994 Presented by A. N. Klimov, Member of the Russian Academy of Medical Sciences     

Impact of ADP on the contractility of intestinal smooth muscle from guinea pigs

Both ADP and adenosine were found to potentiate the anaphylactic contracture of isolated guinea pig ileum (smooth-muscle preparations). When ADP or adenosine was added after the induced anaphylactic reaction, a biphasic change in ileal tonus — relaxation followed by contraction — was noted. The contractile response was abolished by Dimedrol, but not by Troventol. ADP suppressed (or, in some ileal smooth-muscle preparations, reversed) the relaxation response to epinephrine and ocriprenaline and potentiated the naphazoline-induced smooth-muscle contraction. Translated fromByulleten' Eksperimental'noi Biologii i Meditsiny, Vol. 120, N ^o 10, pp. 361–365, October, 1995 Presented by Yu. A. Vladimirov, Member of the Russian Academy of Medical Sciences     

Effect of picrotoxin and bicuculline on desensitization of the GABA receptor/Cl− ionophore complex

A study is performed of the effect of the convulsants picrotoxin and bicuculline, blockers of GABA-dependent Cl⁻-conductivity, on the rate of desensitization of muscimol-induced³⁶Cl⁻ entry into synaptoneurosomes isolated from rat cortex. Both picrotoxin and bicuculline, despite the difference in the mechanisms of inhibition of the GABA receptor/Cl⁻ ionophore complex, markedly reduce the rate of desensitization. However, the initial moment of the action of both convulsants is characterized by inhibition of Cl⁻ transport alone, without a drop of the rate of desensitization. Translated fromByulleten' Eksperimental'noi Biologii i Meditsiny, Vol. 118, N ^o 8, pp. 160–163, August, 1994     

Effects of the nootropics piracetam and GVS-111 on voltage-dependent ion channels of neuronal membranes

The effect of two nootropics, piracetam and N-phenylacetyl-L-prolyglycine ethyl ester (GVS-111), is studied by measuring high-threshold K⁺ and Ca²⁺ currents in isolated snail neurons using a two-microelectrode patch-clamp technique. Piracetam and GVS-111 are shown to reduce the amplitude of both the K⁺ and the Ca²⁺ (to a lesser extent) current. The threshold concentrations for GVS-111 and piracetam are 10⁻⁹-10⁻⁸ M and 1–5×10⁻⁴ M, respectively. It is assumed that the antiamnestic effect of the nootropics is partially mediated by a blockade of ion channels of the neuronal membrane. Translated fromByulleten' Eksperimental'noi Biologii i Meditsiny, Vol. 121, N ^o 2, pp. 151–155, February, 1996 Presented by G. N. Kryzhanovskii, Member of the Russian Academy of Medical Sciences     

Multiple modifications of low-density lipoproteins in the blood of patients with atherosclerosis

Atherogenic low-density proteins (LDL) found in human blood — desialylated, electronegative, and small dense LDL — share many chemical and physical characteristics and appear to represent the same subfraction of multiply modified lipoproteins. Translated fromByulleten' Eksperimental'noi Biologii i Meditsiny, Vol. 120, N ^o 8, pp. 118–121, August, 1995 Presented by D. S. Sarkisov, Member of the Russian Academy of Medical Sciences     

Factors influencing the immunomodulating effect of met-enkephalin: Role of mitogen dose,stage of cell activation,and time of opioid administration

Met-enkephalin in a concentration range of 10⁻¹⁵ to 10⁻⁹ M exhibited an immunomodulating effect upon concanavalin A-induced proliferation of mouse lymphocytesin vitro. The effect of met-enkephalin was shown to depend on the stage of lymphocyte activation, the time of opioid administration, and the dose of mitogen. Met-enkephalin produced the maximal effect when given in the phases of increase or decrease of the proliferative response. Met-enkephalin augmented the proliferative response to the suboptimal dose of concanavalin A and, on the contrary, inhibited the response to the optimal dose of mitogen. Administration of met-enkephalin at different times could both inhibit and stimulate proliferation depending on the stage of lymphocyte activation. An inhibitory effect was induced by δ-class opioid ligand, while κ-ligand was responsible for stimulation. Naloxone abolished the stimulating effect of opioids. Translated fromByulleten' Eksperimental'noi Biologii i Meditsiny, Vol. 119, N ^o 4, pp. 398–401, April, 1995 Presented by R. V. Petrov, Member of the Russian Academy of Medical Sciences     

Use of infrared spectroscopy for analesis of expired air condensates (a new method)

A new method for analyzing noninvasively procured biological materials — expired air condensates — using infrared spectroscopy is described. The proposed method, which involves smoothing out of the condensate spectra and subtraction of the interpolated water spectrum, may be employed in basic research and in developing diagnostic procedures based on quantitative estimation of the organic condensate component. Translated fromByulleten' Eksperimental'noi Biologii i Meditsiny, Vol. 119, N ^o 4, pp. 446–448, April, 1995 Presented by A. D. Ado, Member of the Russian Academy of Medical Sciences     

Ambiguity of the effect of high and low doses of amino-acid preparations on the immune response and phagocytosis in mice

It is shown that the effect of amino-acid preparations (levamine-70–70, cerebrolysin, and aviamine) is dose-dependent. Thus, levamine-70 and cerebrolysin at 65 mg/kg do not affect the immune response but stimulate phagocytosis. Aviamine at 65 mg/kg inhibits the immune response but stimulates phagocytosis and in a dose of 6.5×10⁻² mg/kg boosts both processes. Translated fromByulleten' Eksperimental'noi Biologii i Meditsiny, Vol. 117, N ^o 5, pp. 500–501, May, 1994 Presented by A. D. Ado, Member of the Russian Academy of Medical Sciences     

Structural basis of changes in deformation of synaptic contacts of the sensorimotor and cerebellar cortex in health and acute ischemia

Paramembranous specialized formations of the synaptic cytoskeleton — dense projections and postsynaptic condensation of axospinous synapses of the molecular layer of white rat sensorimotor and cerebellar cortex — in health and acute total ischemia are studied by selective contrast staining with phosphotungstic acid. A direct relationship is revealed between the pattern and degree of deformation of the contact plane, on the one hand, and the postsynaptic condensation and ratio of the volumes of pre- and postsynaptic accumulations of paramembranous filaments, on the other. Translated fromByulleten' Eksperimental'noi Biologii i Meditsiny, Vol. 119, N ^o 4, pp. 443–445, April, 1995 Presented by L. V. Poluektov, Member of the Russian Academy of Medical Sciences     

Synthesis and properties of the immunotoxin CD5-ricin

Synthesis and properties of an immunotoxin produced by conjugating ricin with a novel monoclonal antibody (IgG3 of the ICO-104 class) are described. Cytolytic activity of the synthesized immunotoxin, determined by two independent methods and expressed in LD₅₀, is 0.3–0.6×10⁻⁷ M. Its specificity for target cells containing the CD5 antigen is shown. Translated fromByulleten' Eksperimental'noi Biologii i Meditsiny, Vol. 119, N ^o 1, pp. 76–79, January, 1995 (Presented by Yu. A. Romanov, Member of the Russian Academy of Medical Sciences)     

Mechanism of heart-rate acceleration caused by stimulation of vagal centers in the frog

The mechanism by which heart rate is increased upon stimulation of vagal centers is studied using frog heart preparations perfused with Ringer—Locke solution containing atropine and/or benzohexonium. Atropine stimulates vagus-induced heart-rate acceleration in dilutions of 10⁻⁶ and 10⁻⁵ g/ml. In a dilution of 10⁻⁴ g/ml both atropine and benzohexonium abolish vagal tachycardia. Rausedyl (3–4 injections, 5 mg/kg, at 18–20-h interval) prevents tachycardia. Stimulation of both halves of the medulla oblongata increases heart rate to a greater extent than stimulation of one half. Translated fromByulleten' Eksperimental'noi Biologii i Meditsiny, Vol. 124, No. 7, pp. 16–20, July, 1997     

State of the hematopoietic system in rats subjected to emotional stress after low-dose chronic irradiation

Examination of processes occurring in the hematopoietic system of rats subjected to emotional stress shortly after 30-day exposure to low-dose γ-radiation revealed the inhibitory influence of radiation exposure on the development of adaptive reactions by this system in the stressed animals. Translated fromByulleten' Eksperimental'noi Biologii i Meditsiny, Vol. 119, N ^o 4, pp. 349—353, April, 1995     

Effects of methyluracil and hydroxymethacil on free-radical oxidation in model systems

Three pyrimidine derivatives — methyluracil, hydroxymethacil (a new compound), and its lithium salt — were tested in model systems of differing complexity for antioxidant properties in comparison with the well-known antioxidant ionol. Tests for antiradical activity and for effects on spontaneous and Fe²⁺-ascorbate- or NADPH-dependent lipid peroxidation revealed high antioxidant activity (comparable to that of ionol) of the hydroxymethacil lithium salt. Translated fromByulleten' Eksperimental'noi Biologii i Meditsiny, Vol. 120, N ^o 8, pp. 142–144, August, 1995 Presented by G.N. Kryzhanovskii, 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 bromantane,a new immunostimulating agent with psychostimulating activity,on the release and metabolism of dopamine in the striatum of freely moving rats. A microdialysis study

It is demonstrated that bromantane induces a pronounced and prolonged (8 h) increase in the release of dopanime. Tetrodotoxin (10⁻⁶ M) perfused via a microdialysis probe partially inhibits the bromantane-induced release of dopamine. The extracellular content of the dopamine metabolites 3,4-dioxyphenylacetic and homovanillic acids is slightly decreased. The possible mechanisms of action of bromantane on the dopamin- and serotoninergic systems of the brain are discussed. Translated fromByulleten' Eksperimental'noi Biologii i Meditsiny, Vol. 119, N ^o . 3, pp. 302–304, March, 1995 Presented by M. D. Mashkovskii, Member of the Russian Academy of Medical Sciences     

Individual differences in responses to acute stress associated with type of behavior (Prediction of stress resistance)

On the basis of the initial parameters of behavior in the “open field,” “forced swimming,” and “emotional resonance” tests, the main behavioral parameters — the number of squares crossed, the number of standing postures, and the time of passive swimming — are shown to be predictable for stress in rats with different types of behavior. Translated fromByulleten' Eksperimental'noi Biologii i Meditsiny, Vol. 117, N ^o 1, pp. 89–92, January, 1994 Presented by P. V. Simonov, Member of the Russian Academy of Medical Sciences     

Involvement of fibronectin and interacting serum components in the regulation of activity of human natural killer cells

The cytotoxic activity of natural killer cells and the intensity of conjugate formation are studiedin vitro in the natural cytotoxicity reaction against³H-uridine-labeled human erythromyeloleukotic cells K-562 in the presence of fibronectin, γ-globulin, and fibronectin/γ-globulin combination. It is demonstrated that fibronectin does not change natural cytotoxicity, γ-globulin increases the activity of human natural killer cells, and the fibronectin — γ-globulin combination increases both the intensity of conjugate formation and the cytotoxic activity of natural killer cells. Translated fromByulleten' Eksperimental'noi Biologii i Meditsiny, Vol. 118, N ^o 7, pp. 54–59, July, 1994     

Effect of ionenes on ion permeability of erythrocyte membranes

Ionophore activity of ionenes, like that of polymyxins, is shown to be potentiated by long-chain antiions. Rapid stoichiometric anion equilibration in isoosmotic buffered sugar medium revealed that the amplitude of Cl⁻/OH⁻ exchange in erythrocytes induced by an ionene-detergent complex gradually drops with the decrease of both the charge density and the number of monomeric moieties in the polymeric chain. This is also paralleled by passive K⁺ leakage from the cells. Translated fromByulleten' Eksperimental'noi Biologii i Meditsiny, Vol. 118, N ^o 7, pp. 44–46, July, 1994     

Effect of exogenous acetylcholine on neuromuscular transmission in the stimulated rat diaphragm

Nerve stimulation is performed in rat phrenicodiaphragmal preparations with armine-inhibited acetylcholinesterase. Acetylcholine (1×10⁻⁷ M) is added to the saline for 15 min, and as it is washed off (during 1–2 h), the amplitude of isometric contractions and of the total action potential increases in the continuously stimulated muscle. Contractions in response to direct muscle stimulation remain unchanged. The membrane resting potential of muscle fibers exposed to acetylcholine shifts by 2–3 mV toward hyperpolarization and remains at this level for 2 h after the removal of acetylcholine from the saline. Presented by S. N. Golikov, Member of the Russian Academy of Medical Sciences Translated fromByulleten' Eksperimental'noi Biologii i Meditsiny, Vol. 118, N ^o 11, pp. 457–459, November, 1994     

Distribution of immunoregulatory carbohydrate receptors for lectins on membranes of neurons and syngeneic peripheral lymphocytes

Common immunoregulatory carbohydrate receptors on the membranes of neurons and sysngeneic peripheral lymphocytes of mice are detected by using lectins. Brain neuron membranes possess no receptors characteristic of immature lymphocytes. The common immunoregulatory receptors on brain neurons and mononuclear cells of peripheral immune organs are shown to represent one the mechanisms of integration of the nervous and immune systems. Translated fromByulleten' Eksperimental'noi Biologii i Meditsiny, Vol. 117, N ^o 2, pp. 155–157, February, 1994 Presented by A. P. Romodanov, Member of the Russian Academy of Medical Sciences