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Biomedical subjects

V P Lebedev

Publications and source records attributed to V P Lebedev.

At least 37 records · Page 2Linked to original sources
PubMed1990

[The effect of transcranial electrostimulation of the opioid structures of the brain on peripheral nerve regeneration in the rat].

Transcranial electrical stimulation of opioid brain structures was studied for its effect on the sciatic nerve of rat after transection and microsurgical restoration of the nerve. It was shown that electrical stimulation accelerated regeneration of sensory and motor fibres of the sciatic nerve. Participation of endogenous opioid peptides in the regeneration of peripheral nerves is discussed.

Animals↗
PubMed1990

[Changes in the excitability of the skin mechanoreceptors in the rat against a background of transcranial electrostimulation].

Alterations in excitability of low-, medium- and high-threshold single mechanoreceptors (SMRs) of hairless hind paw skin elicited by transcranial electrical stimulation (TES) in analgesic regime were studied in anesthetized rats. Evoked impulsations of low- and medium-threshold SMRs were blocked by TES that lasted for about 1 and 5 min, respectively. TES for 18-20 min in duration abolished the reactions of high threshold SMRs activated only by nociceptive stimuli. Inhibitory effects of TES on all SMR types under study were eliminated by preliminary intraperitoneal or local intracutaneous (near SMRs location) injection of naloxone. Possible mechanisms of analgesic TES effects are discussed. An assumption is made that alterations of the SMR function are connected with an increase of the output of endogenous opioid peptides from the brain during TES.

Animals↗
PubMed1989

[Age and ventricular secretion in healthy men].

Gastric secretion was evaluated in 821 male inpatients aged 18-55 years with unaffected gastrointestinal, nervous and endocrine systems. With age, there was a tendency to increasing manufacture of gastric juice, hydrochloric acid, pepsin and gastric mucoprotein in 70% of the examinees. Reaching its maximum at the age of 25, the secretion remained stable for the following 15 years, progressively reducing thereafter. To the age of 50 gastric secretion diminished by 16.7%, the parameters lowing in the following order: volume of secretion, concentrations of hydrochloric acid, pepsin, gastric mucoprotein From the onset of physiological involution of the gastric glands observed usually at the age of 40 the response of the glands to reflex intestinal stimuli fell (explanation for basal secretion reduction), while that to humoral stimuli rose (cabbage-water). Hyposecretion may be, however, observed early in adolescence (10% of the examinees) and hypersecretion in middle life (20% of the examinees over 50). The results are thought helpful in clinical practice, occupational selection and mass health examinations of the population.

Adolescent↗
PubMed1989

[Effects of transcranial electrostimulation of the opioid systems on reparative processes in patients with myocardial infarct].

Sixty three patients with primary excessive myocardial infarction (MI) were examined. Transcranial electric stimulation (TES) was demonstrated to contribute to more rapid formation of a postinfarction scar, development of compensatory hypertrophy of the preserved myocardium, and improvement of cardiac contractility. TES-induced activation of the endogenous opioid system was found to be one of the mechanisms responsible for stimulation of reparative processes in patients with MI. Introduction of TES into the multimodality therapy for MI improves the clinical picture of the disease, promoting diminution of circulatory failure signs and relapses of angina-associated pains and favoring decrease in the long-term course of MI and frequency of cardiac arrhythmias.

Arrhythmias, Cardiac↗
PubMed1988

[The opiate mechanism of transcranial electroanalgesia in rats and mice].

In partially restrained alert rats and mice, the opioid mechanism of the transcranial electroanalgesia was investigated. Naloxone (0.5-2.0 mg/kg) reversibly suppressed the electroanalgesia in rats. The electroanalgesic effect in rats tolerant to morphine in doses 5-10 mg/kg, was absent. The involvement of endogenous opioid mechanisms in electroanalgesia was confirmed by enhancing of the analgesia with D-phenylalanine (350 mg/kg). The findings suggest that analgesic effect is based on transcranial electrical stimulation of opioid mechanisms. Investigation of endogenous opioid mechanisms in different antinociceptive brain structures in experimental models of transcranial electroanalgesia, is discussed.

Animals↗
PubMed1988

[Transcranial electroanalgesia in rats: an optimal regimen of electrical stimuli].

According to earlier experimental results in rabbits the maximal analgesic effect in rats as determined by vocalization test was elicited by transcranial application of combination of direct current and rectangular pulses (70 Hz, 3.0-3.5 ms) with optimal ratio of amplitudes of direct and mean pulse currents being about 2:1. In anesthetized rats during the transcranial application of the current with parameters optimal for analgesia the most prominent inhibition of the nociceptive blood pressure reflexes were also shown. The similar results obtained in different species of animals confirmed our earlier conclusion that the most pronounced transcranial analgesia may be elicited by the narrow band current parameters only. Directions of further investigation on the electroanalgesia mechanisms using transcranial current application in rats as an experimental model are discussed.

Animals↗
PubMed1987

[Duodenal ulcer in young males].

A total of 730 young men aged 18 to 22 with peptic ulcer were examined, of them 670 (91.8%) with duodenal ulcer. The follow-up of most patients over time (starting from initial changes up to ulcer formation), a study of risk factors and catamnesis contributed to better understanding of pathogenesis and early diagnosis. Early diagnosis at the stage of acute ulcer (small sizes, weak changes of the gastroduodenal mucosa, high reparative properties and complete cicatrization within a short period) was made in 80% of the patients. In the young men with chronic ulcer (20%) a clinical picture was less typical, a course of disease was torpid, functional indices and reparative properties were on a decrease.

Adolescent↗
PubMed1986

Electrophysiological study of sympathoexcitatory structures of the bulbar ventrolateral surface as related to vasomotor regulation.

The responses in T3-4, T10-11 and L2-3 white rami to stimulation of different zones of the bulbar ventrolateral surface were maximal when the region of about 4 mm laterally to the midline was stimulated. A weak surface stimulation of all these zones elicited only a long latency response consisting of three waves. A short latency response appeared when supramaximal stimuli were applied only to the intermediate zone--the region up to 6 mm rostrally to the hypoglossal nerve root level (zone S and caudal part of zone M). The data presented show that long and short latency responses are conducted from the intermediate zone to the spinal cord via dorsolateral funiculus fibres with a conduction velocity of about 5.6 +/- 0.6 m/s. In addition, a special descending sympathoexcitatory pathway oriented to T2 preganglionic neurons with a conduction velocity of about 12.3 +/- 3.2 m/s was demonstrated. Antidromic discharges of the output sympathoexcitatory neurons elicited by dorsolateral funiculus stimulation were found in the intermediate zone only at a depth of about 400-2000 microM. Stimuli applied to different regions of the ipsilateral bulbar ventrolateral surface activate at least two groups of surface fibres (conduction velocities 6.7-8.0 and 2-3.2 m/s) which, in turn, activate the output neurons with a rather constant delay of about 20 ms equal to a difference between the latencies of long and short latency white rami responses. The mechanism of delay formation seems to be concentrated in the intermediate zone and formed probably by a chain of interneurons. A possible scheme of neuronal organization of the bulbar ventrolateral sympathoexcitatory structures is presented and discussed. The descending tonic activation of spinal vasomotor neurons is formed by spontaneous discharges of antidromically identified output neurons with a mean firing rate of about 14.4 imp./s. Some neurons are reflexly activated within the time limits of the late somatosympathetic reflex response. Coagulation of the intermediate zone resulted in a profound fall of blood pressure, disappearance of pressor and late somatosympathetic reflexes, whereas the spinobulbospinal somatosomatic reflex remains unchanged. The baroreceptor inhibition is partly realized through the elements of sympathoexcitatory intermediate zone because the preferable inhibition of the long latency white rami response was demonstrated in the middle of R-R interval and during a sharp increase in the arterial pressure induced by vasoconstrictor drugs. Thus, the structures of the intermediate zone seem to play a key role in supporting of blood pressure level and organization of pressure reflexes.(ABSTRACT TRUNCATED AT 400 WORDS)

Animals↗
PubMed1985

[Stimulation of restorative processes in stomach and duodenal ulcers].

The effects of RNA preparations and symptomatic agents (antacids and cholinolytics) were studied and compared in patients with peptic ulcer of the stomach and duodenum. It was shown that the use of RNA preparations led to a more rapid disappearance of the endoscopic, x-ray and morphological signs of ulceration, epigastric symptoms, nausea and vomiting, anorexia, "latent" blood in the feces. Altogether 92% of the patients responded to RNA preparations, and 72% to the symptomatic treatment. The rate of relapses it the patients on RNA was 8%, that in the patients on the symptomatic agents amounted to 20%. The mechanism of action of RNA preparations in patients with peptic ulcer of the stomach and duodenum lies in stimulation of protein biosynthesis in the mucous membrane of the involved stomach and intestine, which leads to intensification of the reparative processes.

Adolescent↗