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Biomedical subjects

V I Kobrin

Publications and source records attributed to V I Kobrin.

At least 37 records · Page 2Linked to original sources

[Prepotentials of cells of the contractile myocardium].

The APs of the contractile myocardium cells were studied in heart ventricles of different animal species in hyperkalemia, ischemia, fibrillation. Prepotentials of the "step" type were shown to appear at the front of the AP increment in all cases of impaired conduction of excitation. Quantitative differences of the prepotentials were revealed in fibrillation between mammals and birds.

Action Potentials↗

The structure of night sleep and cardiac rhythm in patients suffering for many years from hypo- and akinesia.

The polygram of night sleep was studied in 3 patients, who due to a lesion to the CNS and peripheral nervous system were in a state of long-term akinesia and artificial lung ventilation. The cyclic organization of sleep and its transition from stage to stage, as a whole corresponded with those in healthy subjects. However, there was a general tendency in all patients to a reduction of sleep spindles. There was also a tendency to the stability of heart rate during night sleep. The relationship between delta-sleep and sleep spindles and motor activity is discussed.

Adult↗

[Comparative study of the action of acetylcholine on the transmembrane potentials of the contractile myocardial cells of the ventricles in adult and newborn guinea pigs].

The transmembrane potentials of the contractile myocardium cells of intact heart and their response to acetylcholine were studied in adult and newborn guinea pigs by means of "swimming microelectrodes". High concentration of acetylcholine only slightly reduces the overshoot without causing changes in other parameters of the transmembrane potentials in adult animals whereas in newborn animals acetylcholine induces hyperpolarization of membrane of the contractile myocardium cells, increases the overshoot and the amplitude of the AP. In adult guinea pigs, acetylcholine prevents irreversible fibrillation whereas in newborn animals acetylcholine prevents spontaneous defibrillation.

Acetylcholine↗

[Microelectrode study of spontaneous defibrillation of the heart ventricles].

The authors investigated the cellular activity of the intact heart of guinea pigs of different age and pigeons both under normal conditions and during fibrillation. It is shown that spontaneous defibrillation is possible with high efficacy of cellular interaction. This leads to synchronization of the cellular activity, hyperpolarization of the cellular membrane and to the restoration of the normal rhythm. Increase of parasympathetic influence tends to block the mechanism of spontaneous defibrillation.

Action Potentials↗

[Structure of nocturnal sleep in akinesia of many years duration and artificial pulmonary ventilation].

The polygram of night sleep was studied in 4 patients, who due to a lesion to the CNS and peripheral nervous system were in a state of long-term akinesia and artificial lung ventilation. The cyclic organization of sleep and its transition from stage to stage, as a whole corresponded with those in norm. However, there was a deficit of delta-sleep, differently expressed in each patient with a general tendency in all patients to a reduction of sleep spindles. The relationship between delta-sleep spindles and motor activity is discussed.

Adult↗

Parasympathetic control of the spontaneous defibrillation of the heart ventricles in animals of various ages.

The role of the parasympatetic division of the nervous system in the process of the spontaneous defibrillation of the heart ventricles in guinea pigs of various ages has been investigated. It was shown that the intensification of parasympathetic control in newborn and sexually mature animals by means of the stimulation of the vagus nerves through the administration of acetylcholine leads to an increase in the duration of ventricular fibrillation, while in old animals this leads to the possibility of its prevention. The important role of the maintenance of sympathetic control in the mechanisms of the recovery of normal cardiac rhythm has been demonstrated.

Acetylcholine↗

[Use of computer-assisted stabilography and the method of computer-assisted biomechanical study of gait in the diagnosis of posture and motor disorders in patients with different forms of infantile cerebral paralysis].

The paper presents and analyzes the results of assessment of vertical stability and walk in patients with infantile cerebral paralysis before and after dynamic proprioceptive correction, which is of great importance for differential diagnosis of different forms of this disease, for controlling the course of therapeutical measures, for working out criteria for the efficiency of treatment.

Adolescent↗

[Prevention of myocardial reperfusion injury by increasing artificial trans-membrane sodium gradient in "calcium paradox" and post-ischemic reperfusion].

An effect of the high sodium gradient during "calcium paradox" and postischemic reperfusion has been studied. A decrease of Na/Ca exchange by high sodium gradient (200 mM NaCl in the perfusion solution) resulted in the reduction of myoglobin release from the heart during "calcium paradox". High sodium concentration solution (200 mM) increased protective effect of ATP during "calcium paradox". Exogenous phosphocreatine (100 mumol/mol) increased myoglobin release from the heart. During perfusion of the heart by high sodium concentration, phosphocreatine efficiently decreased myoglobin release from the heart during "calcium paradox". Exogenous ATP (as Na-pump activator) and high Na+ concentration solution (180 mM) prevented the LDH release from the myocardium, decreased ATP hydrolysis, inhibited Ca influx, maintained total adenine nucleotides, phosphate potential, energy charge of the cardiomyocytes.

Adenine Nucleotides↗