Decrease of antitumor and suppressor activities of nonadherent bone marrow cells by culturing in medium conditioned with ehrlich adenocarcinoma cells

It was demonstrated that proliferation of bone marrow cells cultured in medium conditioned with tumor cells is somewhat increased. A much more potent stimulation of bone marrow cell proliferation is observed after the removal of cells carrying the erythroblast antigen. Translated fromByulleten' Eksperimental'noi Biologii i Meditsiny, Vol. N ^o 5, pp. 514–517, May, 1994 Presented by N. V. Vasil'ev, Member of the Russian Academy of Medical Sciences     

Role of mast cells in reparative processes in inflammation

Using the model of acute infectious peritonitis in rats, it is shown that inflammation induced in the absence of mast cells is characterized by marked inhibition of reparative processes. The most significant accumulation of functionally active fibroblasts and the development of granulations and young connective tissue in the mesentery occur 5–10 days after flogogen injection in the natural development of inflammation and after 10–20 days in the absence of mast cells. The data suggest that under natural conditions mast cells directly or indirectly stimulate reparative processes. Translated fromByulleten' Eksperimental'noi Biologii i Meditsiny, Vol. 119, N ^o 3, pp. 262–265, March, 1995 Presented by E. D. Gol'dberg, Member of the Russian Academy of Medical Sciences     

Activation of nitric oxide pathway mediated by metabotropic glutamate receptors in primary cultures of cerebellar granule cells

Stimulation of L-glutamate receptors (GluRs) is thought to produce neuron death through the elevation of free intracellular Ca²⁺ levels, leading to activation of Ca²⁺/calmodulin-dependent synthesis of cytotoxic amounts of NO·. In the present study, NO synthase activation mediated by mGluR stimulation is investigated in primary cultures of granule cells (CGrC). It is found that a selective agonist of mGluRs, DL-1-aminocyclopentane-trans-1,3-dicarboxylic acid (ACPD), raises both the cGMP and nitrite (NO₂ ⁻) levels, which are used as a biochemical index to study the enzymatic NO· release from L-arginine. This effect is abolished by applying both Nω-nitro-L-arginine methyl ester (NAME) and DL-2-amino-4-phosphonobytyric acid (AP4), and is independent of Ca²⁺. In contrast, the α-amino-3-hydroxy-5-methylisoxarole-4-propionnate (AMPA)-induced increase in cGMP content is eliminated by the preincubation of CGrC with 4 mM EGTA-chelated Ca²⁺. Translated fromByulleten' Eksperimental'noi Biologii i Meditsiny, Vol. 120, N ^o 7, pp. 46–49, July, 1995 Presented by Yu. A. Romanov, Member of the Russian Academy of Medical Sciences     

Comparison of insulin-binding activity of blood cells in diabetes mellitus in pregnant women

Insulin-binding activity of blood cells in pregnant women is shown to vary considerably in health and in diabetes mellitus with different forms and stages of compensation. More stable changes were observed just in erythrocytes. Translated fromByulleten' Eksperimental'noi Biologii i Meditsiny, Vol. 117, N ^o 5, pp. 461–464, May, 1994 Presented by Yu. A. Romanov, Member of the Russian Academy of Medical Sciences     

Effects of muscarine agonists and antagonists on vasopressin-stimulated water transport in the amphibian bladder

The effects of M₁ and M₂ cholinoceptors on stimulated water transport in the urinary bladder of the common frogRana temporaria L. are described. In the presence of pirenzepine, a selective M₁ cholinoceptor antagonist, carbachol stimulated water transport. Activation of M₂ cholinoceptors by oxotremorine in concentrations of 0.5–5.0 μM inhibited water transport, whereas their activation by this compound in higher concentrations (10–100 μM) stimulated it. The use of the phospholipase C inhibitor neomycin (0.5 mM) and the calmodulin inhibitor W-7 (1 mM) indicated that activation of M₂ cholinoceptors switches on phospholipid-Ca²⁺-calmodulin-dependent mechanisms. Translated fromByulleten' Eksperimental'noi Biologii i Meditsiny, Vol. 120, N ^o 9, pp. 252–254, September, 1995 (Presented by P. V. Sergeev, 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     

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     

Bivalphor: a myelopeptide possessing antitumor activity

It is shown that the bone marrow-derived hexapeptide bivalphor restores the functions of human T lymphocytes inhibited by products of HL-60 leukemia cells. Translated fromByulleten' Eksperimental'noi Biologii i Meditsiny, Vol. 119, N ^o 5, pp. 530–532, May, 1995     

The uptake of 3-deoxy-3-iodine-glucose by normal and tumor cellsin vitro

It is found that 3-deoxy-3-iodine-glucose (3D-I-glucose) enters both erythrocytes and tumor cells at a rate close to that of glucose entry. For tumor cells the total uptake of the preparation was 6-fold higher than for erythrocytes (1500 and 250 μM/mln. cells, respectively). Phosphorylated products of 3D-I-glucose were not detected; however, the total amount of preparation in the probes dropped during incubation, indicating that it is metabolized by the cells. Translated fromByulleten' Eksperimental'noi Biologii i Meditsiny, Vol. 117, N ^o 6, pp. 654–655, June, 1994     

Effect of catalin on radical production in aqueous solutions and cross-linking in deoxyribonucleoprotein complex

The effect of catalin on cross-linking in the DNA-protein system is studied after illumination with visible and UV light. Catalin is shown to stimulate this process. The use of a hydroxylamine trap reveals that catalin (10–100 μM) induces the accumulation of free radicals in aqueous solutions as soon as 10 minutes after irradiation. A considerable amount of O ₂ ^- is fixed in the medium during illumination of catalin aqueous solution. Superoxide dismutase added to the incubation medium considerably reduced the number of recorded radicals. Translated fromByulleten' Eksperimental'noi Biologii i Meditsiny, Vol. 118, N ^o 8, pp. 142–144, August, 1994 Presented by I. P. Ashmarin, Member of the Russian Academy of Medical Sciences     

Protective effect of intracerebroventricular injection of adenosine agonists during total cerebral ischemia

Adenosine and its analogs N⁶-cyclohexyladenosine (CHA) and N-ethylcarboxamideadenosine (NECA) are highly effective when injected into the lateral ventricle in very low doses (by 1–2 orders lower than subcutaneously). The protective effect of A-agonists is considered to be mediated by a central mechanism and realized via A-receptors of the brain: the effects of low doses of A-agonists are mediated by A₁-receptors, whereas higher doses exert an extra A₂-effect. Translated fromByulleten' Eksperimental'noi Biologii i Meditsiny, Vol. 117, N ^o 6, pp. 622–624, June, 1994 Presented by P. V. Sergeev, Member of the Russian Academy of Medical Sciences     

“Medium molecules” as nonspecific regulators of phagocytic activity

Three identical oligopeptide-containing fractions of so-called “medium molecules”, isolated by sequential ultrafiltration and gel chromatography from the blood of 8 intact dogs and 15 dogs with an extensive thermal burn, were examined for their impact on phagocytic cells (neutrophil granulocytes and macrophages) in relation to the molecular-weight distribution of the molecules. The relatively high-polymer fractions of medium molecules, unlike oligomeric fractions, stimulated the phagocytic activity of these cells. Because of their increased polymerism, the fractions of medium molecules from dogs with thermal trauma stimulated phagocytosis to a greater extent than did those from intact animals. Translatedfrom Byulleten' Eksperimental'noi Biologii i Meditsiny, Vol. 119, N ^o 2, pp. 159–162, February, 1995 Presented by V. A. Trufakin, Member of the Russian Academy of Medical Sciences     

Effect of human defensins on the cytoplasmic Ca2+ content in platelets

The effect of the total fraction of human defensins (HNP-1, HNP-2, and HNP-3) on the cytoplasmic Ca²⁺ content ([Ca²⁺]_i) in the platelets of healthy donors was studied. At concentrations of 0.1–40 μg/ml and an incubation time of 10 min defensins have no effect on [Ca²⁺]_i in platelets labeled with Fura-2AM. However, at higher concentrations (100 μg/ml) they increased platelet [Ca²⁺]_i. In addition, defensins (40 μg/ml) inhibited the Ca²⁺ increase in platelets induced by thrombin, adenosine diphosphate, and the lipopolysaccharide ofS. typhimurium endotoxin. The most pronounced inhibitory effect was observed in a suspension of thrombin-stimulated platelets. It is shown that the effect of human defensins on the functional activity of platelets is due to the alterations in the intracellular Ca²⁺. Translated fromByulleten' Eksperimental'noi Biologii i Meditsiny, Vol. 118, N ^o 12, pp. 600–603, December, 1994     

Synthetic analog of the thymosinα1 fragment 24–28 alters the coagulating and aggregating activities of α-thrombin

A pentapeptide (EEAEN), which is the 24–28 fragment of the COOH-terminal sequence in the thymosin_α1 molecule highly homologous with the 54–58 region of hirudin (with the complementary anion-binding exosite in the thrombin molecule), was synthesized by a solid-phase method. Preincubation of α-thrombin with EEAEN in concentrations of 0.1 pM to 1 nM reduced its clotting activity while preincubation of this enzyme with EEAEN in concentrations of 0.01 to 1 nM reduced its platelet-aggregating activity. The reaction of EEAEN with thrombin is shown to be similar to the reaction of the entire thymosin_α1 molecule. It is concluded that the COOH-terminal thymosin_α1 peptide EEAEN may be the reactive site responsible for the antithrombin activity of thymosin_α1. Translated fromByulleten' Eksperimental'noi Biologii i Meditsiny, Vol. 120, N ^o 7, pp. 26–29, July, 1995 Presented by I. P. Ashmarin, 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     

Early Resistance to experimental plague in animals immunized with recombinant plague vaccine

The protective properties of recombinantSalmonella minnesota R595/pFS1 strain soon after immunization (1–3 days) are studied in a model of experimental mouse plague. Unlike the commercial EV strainYersinia pestis vaccine produced at the Saratov Anti-Plague Institute (Mikrob Research-Manufacturing Conglomerate), the experimental recombinant p preparation affords a high level of protection from the 1st day postvaccination, and surpasses the commercial preparation in such parameters as LD₅₀, mean survival time, and percentage of survivors. By the 21st day the protective indexes of both preparations are comparable. Translated fromByulleten' Eksperimental'noi Biologii i Meditsiny,Vol. 119, N ^o 1, pp. 54–57, January, 1995 Presented by A. A. Vorob'ev, Member of the Russian Academy of Medical Sciences     

The effect of morphine on RNA synthesis in some brain structures of rats with various narcological resistance

Different incorporation of³H-uridine in RNA and increased RNA synthesis after the addition of morphine are demonstrated in all brain structures of resistant rats, as well as in the cortex, nucleus accumbens, griseum centrale, and nucleus ventriculus hypothalami of prone rats. Translated fromByulleten' Eksperimental'noi Biologii i Meditsiny, Vol. 117, N ^o 1, pp. 100–102, January, 1994     

Response of hypothalamic accessory nonapeptidergic centers to hypophysectomy in rats

Accessory centers were calculated to contain more than 600 nonapeptidergic cells, most of which proved to be oxytocinergic. One week after hypophysectomy, morphometric measurements and morphofunctional changes in the nonapeptidergic cells of accessory centers indicated decreased synthesis of oxytocin and vasopressin by these cells as well as diminished transport of these neurohormones along their fibers. In contrast to the supraoptic, postoptic, and paraventricular nuclei, no degenerative cells were present in the accessory centers following hypophysectomy. Translated fromByulleten' Eksperimental'noi Biologii i Meditsiny, Vol. 117, N ^o 6, pp. 605–608, June, 1994     

Adaptation to hypoxia stimulates the pancreatic islet apparatus in intact and diabetic rats

Using immunocytochemical and immunoradiometric assays, it is found that intermittent exposure to hypoxia stimulates insulin synthesis and secretion by pancreatic beta cells and activatesde novo formation of these cells in the acinar tissue of both intact rats and rats with streptozotocin-induced diabetes mellitus, as well as inhibiting the destruction of Langerhans islets in the latter animals. Translated fromByulleten' Eksperimental'noi Biologii i Meditsiny, Vol. 120, N ^o 12 pp. 565–567, December, 1995 Presented by G. N. Kryzhanovskii, Member of the Russian Academy of Medical Sciences     

Paneth cells of the eastern gray squirrel (Sciurus carolinensis) and red-cheeked suslik (Citellus erythrogenys brandt)

It is shown that the structure of Paneth cells in duodenum of the eastern gray squirrel and red-cheeked suslik is similar to that in other mammals. Seasonal differences in Paneth cell structure are not found in squirrels, while in susliks they are marked. Translated fromByulleten' Eksperimental'noi Biologii i Meditsiny, Vol. 121, N ^o 2, pp. 210–213, February, 1996 Presented by V. A. Trufakin, Member of the Russian Academy of Medical Sciences