[Growing of murine tooth in situ by homotopic transplantation of embryonic germ]. / Vyrashchivanie zuba myshi in situ metodom gomotopicheskoi transplantatsii émbrional'nogo zachatka.

Tissue engineering offers to restore the lost tooth using a biological analogue grown from the tooth germ. These technologies provide long-term cultivation of the germ in bioreactor in vitro. The subsequent transfer and growth of the in vitro grown tooth in the jaw is hampered by difficulty of integration of the new tooth with the host tissue. We suggested that growing tooth by homotopic transplantation in situ, that is, immediately in the jaw passing the in vitro stage will help to solve these problems. The aim of the work was to test the hypothesis. The principal possibility of transfer of the tooth germ directly into the jaw and cultivation in situ eliminating the stage in vitro is shown. The results showed a good integration of the grown teeth with the jaw without signs of inflammation and with the appearance of blood vessels in the pulp. At the same time, the results also showed the necessity to improve the preparation of tooth germs for transplantation and surgical procedures.

[Gaba and its Receptors in Pathogenesis of Epilepsy].

This review presents summarizes data on the structural and functional organization of the GABAergic system of the brain, mechanisms of GABAergic transmission, about the characteristics of GABA-receptors and GABAergic inhibition forms. Reviewed issues of involvement of GABA inhibitory neurotransmitter and various types of GABA-receptors in epileptogenesis. The experimental and clinical data testifying to an important role of GABA and its receptors in an epileptogenesis are presented.

[Autoantibodies to glutamate, GABA and their receptors in epilepsy].

This review discusses the pathogenic role of autoantibodies (autoAB) to excitatory and inhibitory neurotransmitters glutamate, GABA and their receptors in the pathogenesis of epilepsy. The data of clinical and experimental studies show that glutamate AMPA and NMDA- receptors autoAB and GABA receptors autoAB in high titers are highly pathogenic, causing a significant decrease of the density of the receptors and contribute the neuronal death. Discusses the results of experimental data about of the anticonvulsant action of glutamate antibodies (AT) and opposite proconvulsant effect of GABA antibodies in different models of epileptic activity.

[Effect of citicoline on the development of chronic epileptization of the brain (pentylenetetrazole kindling) and acute seizures reaction of kindled mice C57Bl/6].

In experiments on mice C57Bl/6 was studied effects of citicoline (500 mg/kg, i.p.) on development of chronically epileptization of the brain--pentylenetetrazole (PTZ) kindling (30 mg/kg PTZ, i.p. during 24 days) and on acute generalized seizures (i.v., 1% solution of PTZ with the speed of 0.01 ml/s). It was shown that daily injection of citicoline an hour before the introduction of PTZ had no effect on development of chronically epileptization of the brain --PTZ-kindling (the latency of seizures appearance and their severity). However, citicoIine posses anticonvulsive effects on acute seizures in kindled mice. In animals with increased seizure susceptibility of the brain caused by kindling and severity of seizures 2-3 points injection citicoline after 14 days of kindling had anticonvulsive effect, increasing the threshold clonic seizures. Injection of citicoline during 24 days of kindled animals and severity of seizures 3-5 points caused the increase of thresholds as clonic and tonic phase of seizures with lethal outcome. Thus, the anticonvulsant effect of citicoline more pronounced in the long-term use.

Gene gun-mediate DNA vaccination against foot-and-mouth disease virus.

Foot-and-mouth disease (FMD) is one of the most dangerous diseases of cloven-hoofed animals and is a constant threat in the Middle-East and other regions throughout the world despite intensive vaccination programs. In this work, we describe the ability of FMDV expression constructs to protect pigs from FMDV challenge when used as a vaccine. The construct consists of encephalomyocarditis virus (EMCV) internal ribosome entry site (IRES), the entire P1 and 2A together with 3CD sequences, all in the same reading frame. Another plasmid that was tested, carries the serotype O1 (G) VP1, Asia1 VP1 and O1 (G) 3C. Between each of the genes the 3C cleavage sequences were inserted. All constructs carried the cytomegalo virus (CMV) promoter. Using immunofluorescent and immunoblot techniques, we could show the expression and processing of viral proteins. Following the application of FMDV expression constructs into pigs skin by 'Gene Gun', pigs were partially protected from FMDV challenge.

Beta-agonist-induced inhibitory-guanine-nucleotide-binding regulatory protein coupling to adenylate cyclase in mollusc Anodonta cygnea foot muscle sarcolemma.

In the sarcolemma fraction of foot muscles of a fresh-water bivalve mollusc, Anodonta cygnea, a direct inhibitory, rather than stimulatory, effect of the beta-adrenergic agonist isoproterenol, at micromolar concentration, on cAMP level and adenylate cyclase activity, was revealed. It was blocked by beta- but not alpha-adrenergic antagonists. A single class of [3H]dihydroalprenolol-binding sites with binding properties of beta-adrenergic receptor was detected in mollusc sarcolemma. Potentiation of the inhibitory effect of isoproterenol on mollusc adenylate cyclase activity by GTP or guanosine 5'-[beta,gamma-imido]triphosphate at micromolar concentrations, and its elimination in the presence of guanosine 5'-[beta-thio]diphosphate, were shown. The pertussis-toxin-induced ADP-ribosylation of sarcolemma 40-kDa protein [immunochemically related in the C-terminal part to pertussis-toxin-sensitive guanine-nucleotide-binding regulatory protein (G-protein) alpha subunits of vertebrates], as well as the treatment of mollusc sarcolemma with antisera responsive to the C-terminus of vertebrate inhibitory G-protein (G(i)) alpha subunit led to elimination of the inhibitory effect of isoproterenol on adenylate cyclase activity. The results obtained suggest that beta-agonist-induced inhibition of adenylate cyclase in A. cygnea foot muscle may be realized via the beta-adrenoreceptor/G(i) signalling pathway.

Ontogenetic study of the regulatory and coupling function of guanyl nucleotide-binding proteins in the hormone-sensitive adenylate cyclase system.

Reconstitution of catecholamine-sensitive adenylate cyclase from chick embryonic muscle membranes and guanyl nucleotide-binding proteins of mature rabbit muscle makes it possible to reveal the coupling (potentiating) effect of these nucleotides 1 week earlier than in the native condition. The effective insertion of guanyl-nucleotide-binding proteins into the embryonic membrane coincides with the onset of a pronounced increase in membrane lipid fluidity during the course of embryogenesis. The different ontogenetic time-courses for the origination of the two guanyl nucleotide effects, on catalytic adenylate cyclase activity (in early embryogenesis) and on the coupling process (in postembryonic life), suggest the existence in this system of two separate guanyl-nucleotide-binding proteins performing regulatory and coupling functions, respectively.

On the role of guanyl nucleotides in adenylate cyclase system of embryonic skeletal muscle.

The effects of guanyl nucleotides on the catalytic and catecholamine-stimulated activities of adenylate cyclase in developing chick skeletal muscles were studied. GTP and guanylyl imidodiphosphate stimulate the cyclase catalytic activity already at the early embryonic stages without having potentiating influence on the catecholamine-stimulated activity in embryonic muscle. In a distinct and regular form this effect can be observed only after hatching. Therefore during embryogenesis the coupling function of the GTP-binding component of adenylate cyclase system characteristic of its mature state is not manifested. The effects of the nucleotide suggest that they occur as two independent processes.

Functional properties of catecholamine-sensitive adenylate cyclase system in embryonic chick skeletal muscle.

1. At the embryonic stages the adenylate cyclase of chick skeletal muscle possesses high catalytic activity, which is about 10 times higher than its mature level. 2. The reactivity of adenylate cyclase system to catecholamines appears in embryogenesis by the end of the second week, whereas the dose dependence only appears in the third week. 3. The stimulatory effect of catecholamines on adenylate cyclase in chick skeletal muscle is mediated through the beta-adrenoreceptor. 4. The suggestion is made that the limiting factor in the development of adrenoreactivity of membrane adenylate cyclase system is the number of receptors.