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Biomedical subjects

M M Khananashvili

Publications and source records attributed to M M Khananashvili.

At least 19 recordsLinked to original sources
PubMed2006

Effects of partial intraspecies deprivation of rats on short-term image memory.

An individual's zoosocial experience plays a significant role in the formation of adaptive behavior in animals. Published data show that significant restriction of intraspecies interactions induces impairments of higher nervous activity, including such functions as learning, memory, and the control of emotions. These changes are particularly marked when deprivation of zoosocial interactions occurs in the early stage of the animal's postnatal development. We have previously demonstrated that psychogenic stress in rats reared from an early age (from 14 days after birth) in conditions of visual and tactile deprivation leads to impairment of long-term (conditioned reflex) memory functions, this being accompanied by significant suppression of self-regulatory brain activity. The aim of the present work was to investigate the effects of partial intraspecies deprivation in early ontogenesis on overall behavior and short-term memory in adult rats.

Age Factors↗
PubMed2006

[Dynamics of rat behavior in conditions of psychogenic stress during alcoholic motivation].

The goal of the work was to study behavior of rats in conditions of psychogenic stress on the background of ethanol intake. Experiments were carried out on 12 mature while rats weighing 150-200g. Before the beginning of the experiments during one month rats with high and low ethanol intake have been identified. Conditioned reflexes of active avoidance of the tone of 500 Hz and metronome knock using defensive method were elaborated in the next series of the experiments in the "stress box". At the same time behavioral characteristics (horizontal and vertical standings, intrasignal passages, grooming) were studied. It is interesting to note that in the process of separate elaboration of conditioned defensive reflexes as well as against the background of their "combination" much drinking rats became little drinking ones, and vice versa. General behavior of the animals also changed. A mean duration of horizontal standings intrasignal passages and grooming increased at the stages one and two, while they decrease at the stage three. As to vertical standings, their mean duration increased stage by stage. A mean duration of horizontal and vertical standings in little drinking rats decreased at the stages one and two, while dramatically increased at the stage three. All these behavioral reactions are considered to be self-regulating behavior, directed to the increase of organism resistance for the functioning of the brain in conditions of psychogenic stress.

Alcohol Drinking↗
PubMed2002

[Clinical and prognostic significance of seasonal factor in endogenous maniac states].

The study aimed at determination of clinical and prognostic significance of seasonal factor in endogenous maniac state development. Using clinico-psychopathological and clinical follow-up study, 32 patients (30 women and 2 men) aged 20-50 years with seasonal endogenous mania were examined. Seasonal mania developed in 12 patients with bipolar affective disorder, in 13 patients with schizoaffective psychosis and 7 patients with attack-like schizophrenia (F31.1 - F31.6, F25 and F20.02 + F25 ICD-10 items respectively). Seasonal maniac state was shown to be a significant clinical symptom that might be regarded as a prognostic factor. In patients with bipolar disorder--with a prevalence of both mania and depression-seasonal mania development in autumn-winter period was a favourable prognostic trait, being observed mainly in manic depressive psychosis. In spring-summer mania, prognosis was less favourable and was preferentially found in schizoaffective psychosis and attack-like schizophrenia.

Adult↗
PubMed2000

[Specific aspects of endogenous mental disorders with seasonal depressions].

The clinical features and the course of seasonal depressions in endogenous mental diseases were studied with psychopathological and follow-up methods. The seasonal depressions in 50 patients were developed in the psychopathological structure of manic-depressive psychosis (22 patients), schizoaffective psychosis (23) and schizoaffective variant of schizophrenia (5). There were found the considerable differences in the characteristics of seasonal depressions in the indicated endogenous psychoses. The was established that spring summer depressions had more favorable prognostic meaning in comparison with fall-winter depressions. There was shown that changes or disappearance of the seasonal rhythm of depression's development was prognostic unfavourable sign and pointed to the change to the worse of disease.

Adult↗
PubMed2000

[Special features of autonomic regulation in patients with seasonal depression].

Parameters of histograms distribution of ECG R-R intervals (the mode, mode amplitude, variation range) were compared in 60 healthy individuals and 45 patients with seasonal depressions. These ECG parameters reflect influence of sympathetic and parasympathetic parts of the autonomic nervous system on the rhythms of cardiac contractions. In the period of active development of depressive symptomatology the parameters of histograms in terms of R-R distribution were changed in comparison with the healthy individuals: mode was displaced to the region of the short intervals, the mode amplitude was increased and the variation range was reduced. All these data indicate increase of the sympathetic activity and reduction of parasympathetic activity as compared with the control individuals. In the patients with spring-summer depressions the determined parameters of autonomic nervous system were more changed than in the patients with autumn-winter depressions. Under the course of pharmacotherapy the dynamics of these parameters was less marked in patients with fall-winter depressions than in cases of spring-summer depressions.

Adult↗
PubMed1998

[Characteristics of clinical effects of paxil in the treatment of endogenous depression].

47 patients with endogenous depressions were treated with paxil (paroxetine) during 4 weeks in the daily dose of 30-40 mg. Improvement of psychical state was observed in 89.3% of the patients; improvement was significant in 78.7%. Severity of the depression reduced from 28.9 to 6.0 scores according to Hamilton Depression Rating Scale. Antidepressive activity of paxil was observed at the third day of the therapy. Symptoms of depression disappeared completely in 46.7% of the patients 2 weeks after the beginning of treatment and in 62.8% of the cases in 4 weeks. Thymoleptic and sedative-anxiolytic effects prevailed in the spectrum of antidepressive activity of paxil; while its stimulating effect was expressed smaller. Mentioned peculiarities of paxil action, its small toxicity and positive subjective attitude of the patients towards the drug make this preparation quite valuable, especially in the treatment of classic melancholic and anxious depressions.

Adolescent↗
PubMed1998

[Psychogenic stress: theory, experiment, practice].

Experiments on animals (rodents, beasts, primates) and observation in man have ascertained that psychogenic stress is the most important defensive state of living organisms, which is constantly involved in order to maintain their interaction with external psychogenic factors. Three types of stress should be distinguished, these include normostress, hypostress, and hyperstress. Normostress has definite limits within which optimal responses, which are typical for an individual are realized. Hyperstress develops as a defensive response to extremely strong (extraordinary) stimuli. Hypostress can be observed in the retarded development of self-regulation mechanisms. All three types of stress are provided by a fundamental property of living organisms--the self-regulation mechanism, which realizes the keeping back of normostress constancy, or return of hyper- and hypostress to the normostress status. And only if an extreme deficit of self-regulation mechanisms takes place, hyper(hypo)stress could become a condition for the development of pathology.

Animals↗
PubMed1992

[The uncoupling of the functioning of the force generation and ATP hydrolysis centers in the myocardial myofibrils in experimental informational disease].

Active and rigor force generation under the effect of electrostatic charge, the temperature and pCa, was significantly decreased in informational experimental disease. Other significant changes on the molecular level occurred in cardiomyocyte contractile apparatus in conditions of experimental informational disease.

Adenosine Triphosphate↗
PubMed1988

[Arterial hypertension in dogs in a state of experimental informational pathology of higher nervous activity].

A stable arterial hypertension was obtained in dogs by means of experimental pathology of higher nervous activity (behavior) produced with a prolonged work of the brain in conditions of unfavourably combined triad of factors: large volume of information to be processed and assimilated, the factor of time set for such brain work, and a high level of behavioral motivation. Three types of arterial hypertension were revealed to correlate with the changes in behaviour. One form of this behaviour is the self-regulatory activity reflecting the defense mechanisms of the brain. A high degree of self-regulatory behaviour was found to increase the stability of the organism in arterial hypertension, whereas weakening of the behavioral self-regulation favoured the occurrence and development of the hypertension.

Animals↗
PubMed1987

Subcellular bases of cardiac disturbance in experimental informational neurosis.

In experimental informational neurosis, accompanied by the development of stable arterial hypertension, tachycardia and dystrophic alterations in myocardium, the contractile protein ability to generate force and produce work as well as the power of the contractile process are significantly decreased and so is the intensity of Ca2+ transport through membranes of sarcoplasmic reticulum and mitochondria. Ca2+ content in these structures and energetic supply to the cardiac muscle do not change as compared with the control. Noradrenaline content in myocardium increases 5-fold compared with the control and 2.5-fold compared with the norm, while blood content falls to zero (sympathetic neuro-muscular contact is 'locked up' for noradrenaline outflow into the blood); dopamine content increases. Adenylate cyclase sensitivity to the stimulating effect of noradrenaline and NaF diminishes. Basal activity of phosphodiesterase increases, and its sensitivity to the inhibitory action of high calcium concentrations decreases. The disturbance in these systems may, on the one hand, be due to neural effects, and pressure overload of the heart, on the other hand, to the sharp rise in noradrenaline content in the myocardium and the change in the activity of cyclic adenosine monophosphate enzymes. It is suggested that similar changes may take place in the human myocardium and may underlie the cardiac weakness.

Adenylyl Cyclases↗
PubMed1985

[Energy support and the contractile capacity of glycerinized myocardial fibers in experimental informational neurosis].

Experiments in dogs revealed that in informational neurosis the ability of myocardial contractile protein system (myocardial glycerinized filament bundles) to develop tension and produce work as well as the power of the contractile process are considerably reduced. Obviously, the energy production is not disturbed as a lower myocardial content of ATP (by 12%) and particularly of CP (by 54%) is caused by 8-9-month hypokinesia. Analogous shifts seem to occur in the human heart in informational neurosis which, in combination with the reduced intensity of the calcium transport by sarcoplasmic reticulum and mitochondria, may underlie the development of heart weakness.

Adenosine Diphosphate↗
PubMed1984

[Catecholamine concentration and adenyl cyclase and phosphodiesterase activities of the sarcolemma of myocardial cells during hypokinesia and in experimental information neuroses].

Restriction of motor activity and motor-alimentary conditioning in dogs reduced the adrenaline (A) and noradrenaline (NA) contents in the myocardium, dopamine, too, revealing a tendency to reduction. Basal activity of the sarcolemma adenylate cyclase (AC), its sensitivity to A, NA and NaF did not change as well as the basal activity of sarcolemma phosphodiesterase (PDE) and its sensitivity to the inhibitory effect of high concentrations of Ca2 (10(-4) M). In experimental informational neurosis, NA content in the myocardium increased 5-fold compared to control values, the dopamine content also increasing. Basal activity of the sarcolemma AC did not change whereas its sensitivity to NA and to activating effect of NaF decreased. Basal activity of PDE increased and its sensitivity to Ca2 effect decreased in this condition. The increase of PDE activity and increase of its sensitivity to the inhibitory effect of high concentrations of Ca2+ in combination with desensitization of the regulatory subunit AC to NA followed by changes in its catalytic subunit, seem to lead to a decrease of cAMP content and cAMP-dependent phosphorylation in cardiomyocyte that may underlie the Ca2+ transport disturbance observed in informational neurosis, and reduction of contractility of the contractile protein system. Heart pressure overload, caused in informational neurosis by the stable arterial hypertension may play an important role in the genesis of this reduction.

Animals↗