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     

A method for monitoring toxic damage to the liver,based on measurement of total water and its magnetic relaxation characteristics

Acute poisoning of rats with the hepatotropic poison tetrachloromethane was accompanied by increases in the liver content of total water and its spin-lattice (T ₁) and spin-spin (T ₂) relaxation times and by a decrease in theT ₁/T ₂ ratio, with reversal of the correlation betweenT ₁ andT ₂. The antihypoxic agent sodium γ-oxybutyrate normalized water metabolism in the liver almost completely. It is concluded that total water content andT ₁ are the more informative parameters for monitoring both toxic liver damage and the efficacy of its pharmacological correction. Translated fromByulleten' Eksperimental'noi Biologii i Meditsiny, Vol. 120, N ^o 12, pp. 584–586, December, 1995 Presented by Yu. A. Vladimirov, Member of the Russian Academy of Medical Sciences     

Vestibuloprotective activity of seal serum proteins

Cat and rat experiments show that the protein fraction isolated from blood serum of the Greenland seal has a protective activity against motion sickness. This activity is comparable to that of the classical vestibuloprotector scopolamine and is greater than that of diprazine. Radioligand assay of the receptor binding showed that the serum protein fraction has the highest affinity for α₂-adrenoceptors, μ-opioid, and benzodiazepine receptors. Translated fromByulleten' Eksperimental'noi Biologii i Meditsiny, Vol 117, N ^o 4, pp. 444–445, April, 1994     

Effect of cortisol and pertussis toxin on the cAMP concentration in human lymphocytes

It is demonstrated that pertussis toxin and hydrocortisone potentiate the adenosine-induced rise of the cAMP concentration in lymphocytes. Hydrocortisone elicits an immediate (for the simultaneous addition of adenosine and cortisol) and reversible effect. The effect of pertussis toxin has a latency and is irreversible. Added together, these agents exert no cumulative effect. It is assumed that hydrocortisone and pertussis toxin have the same target — The inhibiting regulatory protein G_i. Translated fromByulleten' Eksperimental'noi Biologii i Meditsiny, Vol. 119, N ^o 2, pp. 171–173, February, 1995 Presented by P. V. Sergeev, Member of the Russian Academy of Medical Sciences     

Role of glycolysis in the maintenance of the energy-synthesizing function of hepatocytes from rats adapted and nonadapted to hypoxia at different oxygen concentrations

It is demonstrated that the lactate-Po₂ dependence is the same in hepatocytes of rats with high and low resistance to hypoxia and does not correlate with phasic changes in the ATP concentration in the 890–50 μM O₂ region. Strong activation of lactate formation against the background of ATP decrease indicates that glycolysis is not the major mechanism determining the steady-state ATP level in the cell and affecting the ATP-Po₂ relationship in a wide range of oxygen concentrations. The intensity of glycolysis in hepatocytes of rats with high resistance to hypoxia is markedly increased after periodic adaptation to hypoxia but remains practically unchanged in the hepatocytes of low-resistance rats. This indicates that fundamentally different compensatory mechanisms are involved in this process in the liver of high- and low-resistance rats. Translated fromByulleten' Eksperimental'noi Biologii i Meditsiny, Vol. 119, N ^o 1, pp. 28–32, January, 1995     

Effect of salicylates on the toxicity of GABA-lytics in mice

Preliminary injection of aspirin and salicylic acid increases the toxicity of picrotoxin, but not of bicuculline. Aspirin inhibits binding of³H-diazepam and N-methyl-³H-methylphenazepam with membranes from the brain of intact mice. In view of the fact that salicylates reduce the content and sorption capacity of serum albumin, this protein can be assumed to be involved in the detoxication of picrotoxin. Translated fromByulleten' Eksperimental'noi Biologii i Meditsiny, Vol. 119, N ^o 6, pp. 619–620, June, 1995     

Effect of perfluorodecalin on picrotoxin toxicity and some detoxication systems

Preliminary administration (at least 7 days before the experiment) of perfluorodecalin boosts resistance to the toxic action of picrotoxin in rodents. The antidotal activity of diazepam rises under these conditions. Perfluorodecalin induces the activation of monooxygenase, conjugation, and antioxidant detoxication systems; the protein content increases in the blood serum and carboxylesterase activity is enchanged. Translated fromByulleten' Eksperimental'noi Biologii i Meditsiny, Vol. 119, N ^o 2. pp. 176–178, February, 1995     

Immuno- and phagocytosis-modulating properties of low doses of B1-aflatoxin and benzene

Benzene or benzene-dissolved B₁-aflatoxin in low doses promotes an increase of the Thy-1⁺ cell count in the bone marrow of mice and an enhancement of the thymusdependent immune response.In vitro aflatoxin and benzene are unable to induce the expression of Thy-1-antigen in bone marrow T-precursors. Translated fromByulleten' Eksperimental'noi Biologii i Meditsiny, Vol. 117, N ^o 2, pp. 158–160, February, 1994 Presented by S. A. Neifakh, Member of the Russian Academy of Medical Sciences     

The structure of poly(ethylene oxide)-salt complexes with 13c CPMAS NMR and relaxation studies

¹³C cross polarization and magic-angle spinning (CPMAS) NMR studies were made on poly(ethylene oxide) (PEO) complexed wit LiClO₄, NaClO₄, BaSCN, Bal₂ and Ba(ClO₄)₂. The proton and carbon spin-lattice relaxation times in a rotating frame (T_1ρH, T_1ρC) as well as the rate of cross polarization were measured at room temperature. For Ba(ClO₄)₂ the measurements were made with different polymer molar masses and salt concentrations. The changes in relaxation behaviour indicate changes in polymer chain mobility as well as strong interaction between ions and PEO chains. The T_1ρH and T_1ρC decrease with decreasing salt concentration towards the relaxation times of the pure polymer. Nonexponential relaxation behaviour was found for the samples according to the T_1ρC and T_CH measurements.     

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     

Derivation of a new B-cell line from mouse spleen and its characterization

Prolonged culturing of splenocytes of (CBA×C57B1/6)F₁ hybrid mice in RPMI-1640 medium with 15% fetal calf serum resulted in the derivation of a new B-cell line. After a monolayer of stromal fibroblast-like cells was formed, lymphoid cell growth was observed in 4–5 weeks of splenic cell culturing. All the cells of the splenic line belonged to the B series and expressed IgM on their surface; they did not form lymphoid colonies after injection to lethally irradiated mice, and even after 8-month culturing and several passages they could not be differentiated. Translated fromByulleten' Eksperimental'noi Biologii i Meditsiny, Vol. 119, N ^o 2, pp. 183–186, February, 1995 Presented by I. P. Ashmarin, Member of the Russian Academy of Medical Sciences     

Role of the interaction between different types of serotonin and α2-adrenergic receptors in the regulation of audiogenic seizures in DBA/2 micereceptors in the regulation of audiogenic seizures in DBA/2 mice

It is shown that the serotonin receptors 5-HT_1c, 5-HT₃, and 5-HT₄ and α₂-adrenergic receptors are involved in the regulation of audiogenic seizures in DBA/2 mice, and that the effects of these serotonin receptors on the duration and magnitude of convulsive activity are the opoosite of those produced by α₂-adrenergic receptors. Translated fromByulleten' Eksperimental'noi Biologii i Meditsiny, Vol. 119, N ^o 4, pp. 381–383, April, 1995     

Role of cell signaling systems in the regulation of Ca2+-activated potassium channels in erythrocytes

The effect of inhibitors of calmodulin and protein kinase C, complex [AlF₄]⁻, and potassium channel blockers on the parameters of calcium-induced hyperpolarization in human erythrocytes is studied by recording proton distribution between the cytoplasm and incubation medium in the presence of a protonophore. It is shown that the calmodulin inhibitor dis-C₃-5, the protein kinase C inhibitor staurosporine, and the blocker of highconductance calcium-activated potassium channels considerably suppress the calciuminduced hyperpolarization in erythrocytes. High concentration of [AlF₄]⁻ in the incubation medium inhibits hyperpolarization. Translated fromByulleten' Eksperimental'noi Biologii i Meditsiny, Vol. 123, No. 6, pp. 653–655, June, 1997     

Inhibition of platelet aggregation by monoclonal antibodies against glycoprotein IIb–IIIa complex

Monoclonal antibodies CRC64 are obtained against Ca²⁺-dependent glycoprotein IIb–IIIa complex of the platelet membrane which possess the ability to inhibit completely fibrinogen-dependent platelet aggregation. CRC64 is directed against the epitope formed by the glycoprotein IIb–IIIa complex and does not interact with proteins isolated after platelets are treated with ethylenediamine tetraacetate. Complete, reproducible blockade of platelet aggregation caused by 5 μM adenosine diphosphate is noted in an MCA concentration of 3 μg/ml, while in the case of a stronger inductor, namely 1 U/ml thrombin, platelet aggregation is inhibited in a concentration of 5 μg/ml. F(ab′)₂ fragments are also able to inhibit platelet aggregation completely and are usually effective in concentrations lower than native monoclonal antibodies. Translated fromByulleten' Eksperimental'noi Biologii i Meditsiny, Vol. 118, N ^o 10, pp. 402–405, October, 1994 Presented by V. N. Smirnov, Member of the Russian Academy of Medical Sciences     

Mobilization of intracellular Ca2+ induced by ADP and thrombin in platelets from diabetic patients with vascular complications

It is shown that the baseline level of cytoplasmic Ca²⁺ in platelets from diabetic patients is nearly 1.5 times as high as in healthy donors. The thrombin-induced increase of intracellular Ca²⁺ in patients with angiopathies is reliably lower than in the control, while in patients without angiopathies it is higher than that in donor platelets. The evevation of cytoplasmic Ca²⁺ induced by ADP is greater in both groups of patients. No Changes are found in the baseline level of intracellular Ca²⁺ or in the ADP-induced concentration of Ca²⁺ in platelets from diabetic patients during a 12-week course of insulin therapy. The intracellular Ca²⁺ does not rise after 2 weeks of insulin treatment in platelets from diabetic patients. Translated fromByulleten' Eksperimental'noi Biologii i Meditsiny, Vol. 121, N ^o 1, pp. 112–115, January, 1996     

Polyunsaturated phosphatidylcholine micelle-induced decrease of atherogenicity of the serumin vitro

It is shown that polyunsaturated phosphatidylcholine administered in micelles stabilized by a plant-derived glycoside prevents the accumulation of cholesterol by cells incubated in atherogenic serum and, moreover, in certain cases causes a 1.4–1.5-fold drop of intracellular cholesterol as compared to control cells. The optimum antiatherogenic effect was achieved when using a micelle concentration of 100–200 μg/ml and an incubation time of at least 4 hours. The antiatherogenic effect was analogous to the effect of high density serum lipoproteins. Translated fromByulleten' Eksperimental'noi Biologii i Meditsiny, Vol. 119, N ^o 5 pp. 497–501, May, 1995 Presented by Yu. M. Lopukhin, Member of the Russian Academy of Medical Sciences     

Inheritance of morphine sensitivity in (WAG/G-fischer-344) F1 rats

The effects of morphine on the pain sensitivity and motor activity of progeny obtained by different variants of crossing purestrain WAG/G and Fischer-344 rats are studied. Four groups of rats were investigated: WAG/G (male and female WAG/G rats were crossed), Fischer-344 (Fischer-344 male and female), F/W (Fischer-344 male, WAG/ G female) F₁ hybrids, and W/F (WAG/G male, Fischer-344 female) F₁ hybrids. It is shown that the inheritance of individual features of sensitivity to the analgetic effect of morphine as well as of pain sensitivity is apparently sex-linked. Translated fromByulleten' Eksperimental'noi Biologii i Meditsiny, Vol. 120, N ^o 9, pp. 291–293, September, 1995 Presented by V. N. Yarygin, Member of the Russian Academy of Medical Sciences     

Contribution of the reproductive hormones to the regulation of prostaglandin F2α production by immunocompetent cells

The ability of estradiol, progesterone, and chorionic gonadotropin to influence prostaglandin F_2α production by intact splenocytes of CBA mice was studied. Estradiol and progesterone similarly activated the processes of prostaglandin F_2α production. No relationship was revealed between the effect and the concentration of the hormones. Chorionic gonadotropin activated prostaglandin production by immunocompetent cells but only when used in a concentration reflecting the peak of its physiological secretion. Combining gonadotropin with estradiol or progesterone did not lead to any appreciable differences in the prostaglandin-stimulating action of each hormone alone. Translated fromByulleten' Eksperimental'noi Biologii i Meditsiny, Vol. 120, N ^o 8, pp. 178–180, August, 1995 Presented by K. P. Kashkin, Member of the Russian Academy of Medical Sciences     

A study of the mechanism of action of befol on Ca2+ metabolism in cardiomyocytes using a FURA-2 fluorescent probe

The dynamics of the Ca-response of cardiomyocytes is studied and the efficiency of befol, verapamil, and amiodarone is compared using various experimental models of stimulation of [Ca²⁺]_i. Befol (1–5 μM) is shown to inhibit the caffeine-and strophanthin G-induced rise of [Ca²⁺]_i. Unlike verapamil and amiodarone, befol exhibits no Ca-blocking activity in modeled K-depolarization. It is concluded that the cardiotropic effect of befol is mediated through its primary action on Na⁺/Ca²⁺ exchange in cardiomyocytes, while the cardioplegic effect of verapamil and amiodarone is due to their ability to block the slow Ca²⁺ inward current. Translated fromByulleten' Eksperimental'noi Biologii i Meditsiny, Vol. 121, N ^o 3, pp. 288–291, March, 1996     

Effect of a peptide extract of fetal brain tissue on the intracellular pH of mouse peritoneal phagocytes

The intracellular pH (pH_i) of mouse peritoneal neutrophils, initially 0.2 U, drops after a 15-min incubation of these cells with a peptide extract of fetal brain tissue. Treatment with the preparation leads to appreciable changes in the distribution of neutrophils by the examined parameter. For macrophages, the acidifying effect of the agent and its effect on the pattern of cell distribution in terms of pH values are far less expressed. The effects of the agent in dilutions 1∶10² and 1∶10⁴ on the mean pH_i are virtually the same. Translated fromByulleten' Eksperimental'noi Biologii i Meditsiny, Vol. 120, N ^o 12, pp. 626–630, December, 1995 Presented by V. I. Kulakov, Member of the Russian Academy of Medical Sciences