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Biomedical subjects

A A Dutov

Publications and source records attributed to A A Dutov.

At least 19 recordsLinked to original sources
PubMed2006

[HPLC analysis of urinary metabolites of catecholamines and serotonin for routine laboratory practice].

A simple high performance liquid chromatographic technique has been developed to analyze urinary metabolites of catecholamines along with ultraviolet detection. The metabolites were extracted in ethyl acetate when a biospecimen was saturated with ammonium sulfate. Separation was effected on a column containing 5 microm of Diasphere C16 in the two-stage low-pressure gradient. The eluents were based on acetonitrile-isopropanol-0.02 M citric acid, added by potassium perchlorate, 5 g/l (3 and 10% of its organic phase). The complete chromatographic cycle was about 30 min. The extraction degree was 86-106%. The sensitivity (detection limit) of the technique at a signal/noise ratio of > 3 was 2 ng (vanilylmandelic acid), 3 ng (iso-vanilylmandelic acid) and 3,4-dioxyphenylacetic acid), 1 ng (5-hydroxyindoleacetic acid), and 5 ng (homovanillic acid). The linear dependence was in the range of 5 to 1,000 ng. The author presents his own findings and the data available in the literature on the content of metabolites of catecholamines and serotonin in healthy individuals and in patients with catecholamine-secreting tumors (pheochromocytoma and neuroblastoma).

Catecholamines↗
PubMed1991

[Cavinton in the prevention of the convulsive syndrome in children after birth injury].

The authors studied the efficacy of cavinton as an agent helpful in preventing neurologic disorders in the newborn with hypoxic ischemic encephalopathy due to intracranial birth trauma. The short-term results of the treatment were elucidated in 61 children. In group I including 20 persons given conventional therapy, the disappearance of seizures was recorded in 6 patients; out of 41 children (group II) given additionally cavinton, in 27. Twenty-nine children were followed up for a year. In group I, convulsive paroxysms recurred in 4 patients, whereas in the group II children, no convulsive syndrome was recorded on the follow-up. The group II children also showed a decrease of the phenomena of intracranial hypertension and normalization of the psychomotor development. The preventive effect of cavinton seen in children with a history of birth trauma may be accounted for by its capacity of normalizing cerebrovascular disorders and by its own anticonvulsive properties.

Anticonvulsants↗
PubMed1986

[Use of cavinton in epilepsy].

The authors studied the effect of cavinton (15-45 mg/day) and its combinations with different anticonvulsants on the time-course of different forms of epilepsy. In 20 of the 31 patients studied treatment with cavinton either significantly decreased the frequency of attacks or led to their complete disappearance; in 7 patients the improvement was insignificant and in 4 the condition deteriorated. The greatest effect of cavinton was observed in generalized tonic-clonic convulsions and when they were combined with absences. Clinical improvement not always correlated with EEG normalization. A suggestion is made that the mechanism of the anticonvulsive action of cavinton may be explained both by the normalization of the cerebral blood flow and elimination of hypoxia and by the fact that the drug may possess anticonvulsive properties unrelated to the normalization of the cerebral hemodynamics.

Adolescent↗
PubMed1986

[Changes in cat behavior as affected by intracerebral microinjections of kynurenine and quinolinic acid].

Behavioural changes induced by microinjections of neuroactive tryptophan metabolites: L-kynurenine sulfate (KYN, 50-1,000 micrograms) and quinolinic acid (QA, 20-1,000 micrograms) were studied in chronic experiments on cats with cannulas implanted into nuclei caudati. Unlike KYN, whose effects were scarce and nonspecific, QA (500 and 1,000 micrograms) produced marked motor and emotional shifts. The effects were manifested in contralateral rotatory movements, limb hyperkinesis, emotional strain, malice, fear, aggression with snarling and hissing, attack on provocation. It is suggested that kynurenines and QA can participate in the generation of emotional disorders peculiar for epilepsy.

Animals↗
PubMed1983

[Neurophysiological and pharmacological characteristics of latent intercaudate asymmetry in the cat].

The head-turning behavior in electrical stimulation of right and left caudate nuclei was tested in chronic experiment in cats. Local head-turning in contra-or ipsilateral direction was found in stimulation of the right caudate nucleus while in the left caudate stimulation generalized locomotor reactions such as controlateral circling, were a more frequent feature. Drugs exerted different effects on reactions of the right and left caudate nuclei to electrical stimulation. L-DOPA and haloperidol increased the intercaudate asymmetry whereas apomorphin and clozapine revealed no such effect. The neurophysiological mechanisms of intercaudate asymmetry and its contribution in pathogenesis of extrapyramidal disorders, are discussed.

Animals↗
PubMed1978

[Comparative assessment of contra- and ipsiversive reactions induced by electrical stimulation of the caudate nucleus in cats].

High-frequency stimulation of the caudate nucleus provoked 2 types of rotatory movements of the head and body in the contra- and ipsilateral direction in unrestricted cats. The contralateral rotations (CR) were provoked from a more extensive area chiefly occupying the dorso-mediocentral portions of the head of the nucleus. In difference from them, the ipsilateral rotations (IR) originated from the ventro-lateral area, possessed tonic component more frequently, were more pronounced and less sensitive to L-DOPA and chlorpromazine. Unilateral damage of the area of CR led to the ipsilateral pose asymmetry. When this asymmetry disappeared administration of L-DOPA or apomorphine readily provoked rotation in the same direction. Destruction of the areas in which the ipsilateral reactions originated gave an opposite result.

Animals↗
PubMed1977

[Characteristics and origin of rotatory movements induced by electrical stimulation of the caudate nucleus in cats].

High--frequency stimulation of the caudate nucleus in cats elicits three types of responses: contralateral turning of the head or rotatory psychomotor excitation with contralateral rotation, and ipsilateral turning of the head and body. The latter was obtained mainly from the ventralateral portions of caudate nucleus, while the psychomotor excitation--from the dorsal portions. The rotatory movements are virtually independent of involvement of capsula interna and cortex. Slow synchronized EEG activity occurring at the moment of turning was eliminated by curarization. The caudate rotations are partially triggered by the globus pallidus, as the electrolytic lesion of the latter increases the thresholds of responses although does not completely eliminate them.

Animals↗
PubMed1976

[Effect of electroshock convulsions on caudate nucleus function].

In unrestrained cats, after the electro--shock seizures, the afamphetamine--indused stereotype, behavior was increased and the caudate circular response to high--frequency stimulation was facilitated. The delayed response to low-frequency stimulation of the caudate nucleus was, on the contrary, decreased. Thresholds of the circular and delayed responses to stimulation of the thalamus and capsula interna did not change in the post--seizure period. The above shifts are supposed to be due to weakening of the caudate nucleus inhibitory function resulting from the electro--shock--evoked increase in the caudate dophamine.

Amphetamine↗
PubMed1976

[Preconvulsive state and hyperfunction of the striatum (clinico-experimental findings)].

The paper is concerned with a clinico-experimental study of the influence of intesified activity in the neostriatum on the EEG indices which may appear during the introduction of increased doses of corazol. In 10 cases with different forms of parkinsonism there was a much easier appearance of clinical and EEG manifestations of convulsive activity, than in normals. In experiments on rats preconvulsive effects were exerted by such neuroleptics as haloperidol unlike apomorphine, possessing opposite properties.

Adolescent↗
PubMedDate not supplied

Character and origin of rotatory movements evoked by electrical stimulation of the caudate nucleus in cats.

High-frequency stimulation of the caudate nucleus in cats induces three types of rotatory responses: turning the head or stepping movements in a circle toward the side opposite to that of stimulation, psychomotor excitation with contralateral rotation, and ipsilateral turning of the head and trunk. Movements of the last type developed mainly from the ventro-lateral zones of the head of the caudate nucleus, whereas psychomotor excitation, on the other hand, developed from the dorsal zones. Rotatory movements do not depend significantly on a contribution of the internal capsule or cortex. Slow synchronized activity on the EEG at the time of rotation was abolished after curarization of the animals. Caudate rotation is partly due to activation of the globus pallidus, for electrical stimulation of that structure raises the threshold of the responses although it does not block them completely.

Animals↗
PubMedDate not supplied

[Effects of catecholaminergic substances on the circular reaction caused by stimulation of the caudate nucleus].

The influence of stimulators (L-DOPA and apomorphine) and of inhibitors (chlorpromazine and haloperidol) of the dopaminergic systems on the circular reaction arising during high-frequency (30 puls/sec) stimulation of the caudate nucleus was studied in chronic experiments with freely moving cats carrying preliminarily implanted electrodes. L-DOPA and apomorphine inhibited, while chlorpromazine, on the contrary, facilitated the development of a contralateral circular reaction. L-DOPA and chlorpromazine modified in a more pronounced fashion the circular reaction than did apomorphine and haloperidol. In the mechanisms of the circular reaction, apart from the dopaminergic component, the participation of noradrenergic systems is suggested.

Animals↗
PubMedDate not supplied

[Effect of corazole on the functional activity of the caudate nucleus].

In chronic experiments with freely moving cats the action of diverse metrazol doses on the d,1-amphetamine-induced stereotype behaviour and the arrest reaction following low frequency stimulation of the caudate nucleus was studied. After injections of metrazol (20--30 mg/kg, i.c.) myoclonic seizure jerks and decreased locomotion occurred. This state was accompanied by depression of the stereotype behaviour and lowered arrest reaction threshold. It is suggested that some behavioural and the EEG metrazol-induced changes may come as a result of the caudate nucleus activation.

Amphetamine↗
PubMedDate not supplied

[A simple method for determining antiepileptic preparations in biological fluids by using high-pressure liquid chromatography (HPLC)].

The authors suggest a simple HPLC method with ultraviolet detection at 200 nm for finding barbiturates, diphenine, etosuccimide, and carbamazepin in plasma and saline using an original technology of liquid-liquid extraction. It allows clear chromatograms with a minimal amount of interfering compounds, a high extraction percentage (90-100%) and sufficient sensitivity to be obtained. A method has also been worked out for detecting clonazepam on the basis of solid-phase extraction (cartridge "Diapak-C16") precolumn concentration, and ultraviolet detection at 200 and 215 nm. The suggested extraction technologies also make possible successful monitoring of antiepileptics in the saline, for which the plasma/saline coefficients are calculated and the dependence between the degree of phenobarbital extraction into the saline and its pH is demonstrated.

Anticonvulsants↗
PubMedDate not supplied

[Behavioral and EEG signs of the convulsive action of kynurenine and quinolinic acid in cats].

Administration of quinolinic acid but not L-kynurenine into the cat caudate nucleus was found to produce the appearance of epileptiform charges in the EEG with concomitant behavioral convulsions. A combination of quinolinic acid injections with systemic administration of penicillin resulted in the development of the status of myoclonic convulsions alternating with generalized tonicoclonic seizures. These states were eliminated by diazepam. The right caudate nucleus was revealed to be more sensitive as compared to the left one to the convulsant action of combined administration of quinolinic acid with penicillin.

Animals↗
PubMedDate not supplied

[Pharmacological analysis of the anticonvulsant action of kavinton].

In experiments on rats it was found that cavinton administered in doses of 1-30 mg/kg exerted a distinct dose-dependent anticonvulsant effect, according to the test of maximal electroshock, not less than that of phenobarbital, difenin and carbamazepine. Combined use of cavinton and these drugs potentiated its anticonvulsant action. The involvement of noradrenergic systems, in particular, alpha 1-adrenoceptors, in the anticonvulsant effect of cavinton is suggested.

Animals↗