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Biomedical subjects

A I Luĭk

Publications and source records attributed to A I Luĭk.

At least 19 recordsLinked to original sources

[Evolutionary programming for finding "structure-activity" relationships in a series of 3-phenoxychromone and 3-phenoxy-4-hydroxycoumarin derivatives].

Based on a set of compounds possessing hypolipidemic activity, it was demonstrated that evolutionary algorithms can be successfully used to compile an informative set of molecular parameters. The parameter sets selected using the method of potential functions allowed correct prediction of the activity of test molecules.

4-Hydroxycoumarins↗

[Effects of short-term application of glutamate-containing solution on isolated rat hippocampal neurons].

The "concentration clamp" technique has been modified to realize fast and short-term application of a transmitter to whole neuron followed by its fast washout. Prolonged glutamate application evoked activation of the desensitized current. The application time was shortened to intervals when the washout corresponded to unfinished desensitization of the current. Shortening of the glutamate application term to some milliseconds resulted in arising of fast currents which maximal amplitude appreciably exceeded that of currents evoked by prolonged glutamate application. The role of both components under real synaptic conditions is discussed.

Animals↗

[Study of the recovery rate of non-NMDA desensitized receptors of hippocampal neurons using paired and rhythmic application of glutamate].

The new technique has been used to realize paired short-term application of glutamate to whole dialyzed neuron. Desensitization of receptors via first application of glutamate resulted in incomplete recovery of the current evoked by the second application if interval between both applications was less than 160 ms. The recovery time constant of the current was found to be 44 ms at single exponential approximation. It is close to the mean desensitization time constant of the current evoked by single prolonged application of glutamate. Rhythmic application of glutamate resulted in a rapid fall of the mean current amplitude at frequencies over 10 Hz. Data obtained by the authors confirm the known concept of desensitization of non-NMDA receptors as a relatively slow conformation of the receptor-channel complex.

Animals↗

[The effect of the 5-lipoxygenase inhibitor quercetin on the functional and morphologic manifestations of myocardial lesions in ischemia and reperfusion of the heart].

In experimental canine myocardial infarction induced by an hour coronary artery occlusion, followed by 5-hour reperfusion, quercetin solution, 10 mg/kg, was demonstrated to improve left ventricular myocardial contractility, to reduce the incidence of rhythm and conduction disturbances, to promote the limitation of an ischemic lesion area, to produce a protective effect on the ultrastructure of coronary artery, contributing to the maintenance of vessel integrity, improvement of coronary blood flow, and prevention of intravascular thrombus formation.

Animals↗

[Membrane mechanisms of the effect of alkylating cytostatic agents].

The data bearing witness to realization of the cytostatic activity of alkylating agents by means of interaction with cell membrane receptors was obtained. Alkylating agents block receptors of the polyphosphoinositol system. It is shown that chloralkylamines inhibiting sites coincide with M-++cholinomimetics and alpha-adrenergic receptors, inhibitors of H-histamine receptors, cyclo- and lypoxigenase inhibitors. Such likeness is determined by identical structures of the molecule active part, and quantum-chemical calculations.

Alkylating Agents↗

[Application of neural networks using the volume learning algorithm for the study of structure-activity relationship in chemical compounds].

A volume learning algorithm for artificial neural networks was developed to quantitatively describe the three-dimensional structure-activity relationships using as an example N-benzylpiperidine derivatives. The new algorithm combines two types of neural networks, the Kohonen and the feed-forward artificial neural networks, which are used to analyze the input grid data generated by the comparative molecular field approach. Selection of the most informative parameters using the algorithm helped to reveal the most important spatial properties of the molecules, which affect their biological activities. Cluster regions determined using the new algorithm adequately predicted the activity of molecules from a control data set.

Algorithms↗

[Topological similarity of antagonist binding sites in biogenic amine receptors].

The influence of physical and chemical properties of some sites of transmembrane receptor domains on the receptors ability to interact with nonspecific antagonists was investigated mathematically. The properties of sites located in 3rd and 7th transmembrane domains are most likely to explain pharmacological characteristics of the receptors. The possibility of receptor blocking by nonspecific antagonists not by competing with agonists but by influencing the receptor conformation is discussed.

Animals↗

[Common properties of pharmacological agonists and antagonists of surface membrane receptors].

Using experimental transcription model in vitro, and method of electron-topological calculations the elements of pharmacological and structural community have been found in the groups of physiologically active compounds (PAC), blocking and activating external cellular receptors. This finding confirms the necessity of subdivision special groups of bio-substrates blockators and activators for hierarchical classification, of PAC.

Animals↗