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Biomedical subjects

V I Medvedev

Publications and source records attributed to V I Medvedev.

At least 19 recordsLinked to original sources
PubMed1996

[Role of occupational factors in the incidence and course of respiratory system tuberculosis in fishery workers in the South Far East].

Tuberculosis morbidity among fishery workers in the South of Russian Far East remains high. Moreover, it is higher in fishermen working in the sea than in those who are engaged in fish-factories. This conclusion on fishing as a factor of tuberculosis risk was made basing on the results of 91 patients with tuberculosis of the respiratory organs. 65.9% of them were members of fishing ship's crew (group 1), 34.1% were workers of fish-factories (group 2). Pulmonary infiltrative tuberculosis running with exudation was typical for both groups, but group 1 subjects developed destruction of pulmonary tissue and discharged bacteria significantly more frequently. They had more compromised cellular immunity.

Adult↗
PubMed1984

[General patterns of the sensory processes in exposure to extreme stimuli].

A series of changes in sensory sphere take place in conditions of extremal and unusual influences. These changes are determined directly by processes at the receptor level and indirectly--by the central interaction. In spite of great variety of the influences, there are some general laws in changes of functional state of afferent systems analogous to biophysical and neurophysiological processes. The evaluation of functional state of sensory systems in such conditions can only proceed on ergonomic base taking into consideration the sensory fatigue as well.

Central Nervous System↗
PubMed1983

[Effect of delta-sleep-inducing peptide and its analogs on the encephalogram of normal rabbits during sleep deprivation and on learning processes in the rat].

The delta-sleep-inducing peptide and its 10 analogues increased the total amount of slow oscillations in the rabbit EEG and shifted the spectrum towards the long-wave area. When comparing the EEGs of intact and sleep--deprived rats, the effect of delta-peptide was stronger in the latter animals. The learning of rats in U-shaped labyrinth before and after sleep deprivation suggested that delta-peptide improved the learning in sleep-deprived animals. Experiments with negative influences showed that the delta-peptide could be a protective anti-stress factor.

Animals↗
PubMed1982

[Comparative evaluation of memory-regulating neuropeptides before and after electric shock in albino rats].

Antiamnestic properties of memory neuropeptide--modulators and their effect on learning were studied as well as consolidation of oligopeptide ACTH4-7, vasopressin, oxytocin, leu enkephalin and the melanocyte inhibiting factor. Effect of these neuropeptides on the rat higher nervous activity is bath strong and specific: ACTH4-7 and leu enkephalin speed up the primary learning whereas vasopressin and oxytocin improve long--term memory. Peptides are able to reverse retrograde as well as anterograde amnesia and to preserve previously formed habits from disturbance by electric shock. Vasopressin and the melanocyte inhibiting factor are the strongest antiamnestic factors.

Adrenocorticotropic Hormone↗
PubMed1982

[Effect of neuropeptides modulating memory on the background and evoked electrical activity of the cerebral cortex in the rabbit].

The encephalographic correlations of behavioural activity of oligopeptides from the group of memory neuromodulators and similar substances (arginine-vasopressin, a fragment of adrenocorticotropine ACTH4-7 and four its analogues, leu-enkephalin and melanostatine) were studied in rabbits. The encephalogram was activated by these drugs. The fraction of low-frequency components decreased, that of high frequency increased, the amplitude decreased. The effect of ACTH4-7 and vasopressin on the parameters of visual summary evoked potential was dose-dependent. Neuropeptides reduced the latent period and increased the amplitude of summary potentials or depressed these parameters depending on dose. The effects of vasopressin were long-term in nature and lasted for several weeks. The effects of fragments of ACTH and leu-enkephalin lasted for several hours.

Adrenocorticotropic Hormone↗
PubMed1980

[Experience with the use of posterior pituitary hormones in memory disorders of different etiology].

Results of using vasopressin and pituitrin in 20 patients with memory disturbances of various genesis (due to circulatory disturbances in the vertebrobasilar system, cerebral atherosclerosis, neurasthenia, brain concussion, epilepsy) are reviewed. The therapeutic efficacy of the hormones was evaluated with the use of a complex of psychophysiological methods. Objective changes in the patients' neurological status and subjective state were taken into account. A high therapeutic efficacy of the hormones in the treatment of amnestic syndromes is demonstrated.

Adult↗
PubMed1980

[Effect of neuropeptide fragments of adrenocorticotropic hormone and vasopressin on the behavioral activity of rats].

The effects of vasopressin and those of fragments of adrenocorticotropin ACTH5-10; ACTH4-7; l-phenilalanin, and ACTH4-7 d-phenilalanin on the learning of rats in U-shaped labyrinth were studied. The consolidation of skills in long-term memory ability for reversal learning were checked. The results suggest that effect of all these oligopeptides on the higher nervous activity is significant and specific, vasopressin improving the long-term memory, ACTH4-7-l-phenilalanin improving the learning, ACTH4-7-d-phenilalanin making learning next to impossible.

Adrenocorticotropic Hormone↗
PubMed1978

[Blastomogenic activity of substance complexes that leached out of rubbers into food media].

The complex of agents migrating from low-dispersed soot resins PM-15 and PGM-33, injected in the stomach or applied onto the skin of mice C57Bl, showed an insignificant blastomogenic activity. Most sensitive to their effect were the tissues of organs at the site of injection (proventricular papillomas in 8.3% of cases, skin papillomas in 12.5%), in the lung (adenomas in 12.5%) and in the pancreas (fibroadenoma in 4.2%). In the negative control groups of animals no tumors of such localization were noted. The whole complex of substances migrating from resins renders the blastomogenic effect, i. e. there is a combined action with an enhancement of blastomogenic effect.

Animals↗
PubMed1975

[Study of differential sensitivity to changes in the duration of tonal sounds].

Temporal differentiation by man was studied for intervals from 50 to 700 msec my means of the traditional method of constant stimulus differences (AX) and combinations of AX with methods of multiplication by two and three (AB-2 and AB-3). The linear augmentation of differential limen as function of duration was noted. The limens in methods AB were significantly higher than in the method AX. The values of limens were influenced upon by methods of multiplication, form of psychometric functions, individual features of subjects. No systematic changes of limens during training sessions were found.

Adult↗