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P Turcáni

Publications and source records attributed to P Turcáni.

At least 19 recordsLinked to original sources
PubMed2001

Effect of propentofylline on cerebral blood flow in a gerbil focal cerebral ischemia.

BACKGROUND AND PURPOSE: Neuroprotection and improvement of cerebral blood flow are two basic principles of pharmacological intervention in acute stroke. Propentofylline, an adenosine uptake and phosphodiesterase inhibitor, has been shown to be neuroprotective in various models of cerebral ischemia. However, its effect on cerebral circulation in ischemic conditions is not yet fully elucidated. Present experiments were designed to investigate the effect of propentofylline on regional cerebral blood flow (rCBF) in the gerbil permanent focal cerebral ischemia model. METHODS: Focal cerebral ischemia in gerbils was produced by clipping one common carotid artery and contralateral external carotid artery. rCBF was measured in both parietal cortices concurrently by the hydrogen clearance. RESULTS: Propentofylline at 10 mg/kg administered intraperitoneally 30 min after induction of cerebral ischemia significantly increased rCBF in ischemic regions (increase of 94.6%). Effects were dose dependent. Higher dosage (30 mg/kg) induced reductions of ischemic rCBF, which were associated with significant decreases of mean arterial blood pressure. Lower dosage (5 mg/kg) was without significant effect. CONCLUSIONS: Results suggest that propentofylline at suitable dosage improves rCBF in ischemic brain areas. Taking into account neuroprotective potentials of propentofylline, results offer additional rationale for clinical trials investigating efficacy of propentofylline in treatment of acute stroke.

Animals↗
PubMed1996

HPLC method for measurement of purine nucleotide degradation products in cerebrospinal fluid.

We describe a convenient method for the separation and quantification of xanthine, hypoxanthine, and uric acid in 20 microL of cerebrospinal fluid (CSF) with use of HPLC and ultraviolet detection. The analysis is performed on a Sepharon SGX C18 column and the elution system consists of potassium phosphate buffer, pH 5.1, with 20 mL/L methanol. The lower limit of detection was 4 pmol for hypoxanthine and xanthine and 6 pmol for uric acid. Analytical recoveries of purine metabolites ranged from 98.6% to 102.9%. The intra- and interassay CVs were <3%. The applicability of the method is illustrated with the determination of micromolar concentrations of xanthine, hypoxanthine, and uric acid in CSF samples obtained from 113 patients with various neurological disorders.

Adult↗
PubMed1990

[Specific aspects of mobility and changes in the shape of the dural sac in functional lumbosacral myelography].

The purpose of the work was an analysis of lateral myelograms of the lumbosacral spine in the neutral position, in anteflexion and retroflexion from the aspect of the mobility of the dural sac and its relationship to the spinal canal. The group comprised 50 patients with clinically obvious discopathies and other vertebrogenic syndromes. The areas of the dural sac were measured planimetrically and evaluated by means of a computer. It was revealed: 1. The Soinal canal and dural sac are not static variables but dynamic ones. By movements of the lumbosacral spine the size of the dural sac changes and so does its shape. These phenomena can be evaluated not only qualitatively but also quantitatively. 2. The anteroposterior diameter of the dural sac on the myelograms in anteflexion and in retroflexion changes significantly, as compared with the neutral position, it increases during anteflexion and diminishes during retroflexion. 3. The area of the dural sac increases during anteflexion and diminishes in retroflexion, as compared with the neutral position. 4. Changes in the shape of the dorsal portion of the dural sac revealed in the segment of the discopathy are considered to be due to hypertrophy of the yellow ligaments.

Dura Mater↗
PubMed1989

[The new hemorheologic drug VULM 957 improves cerebral circulation].

The authors investigated the effect of a newly synthetized haemorheological drug VULM 957 for basic haemorheological parameters in vitro and on the cerebral flow in vivo. It was revealed that substance VULM 957 inhibits in a dose-dependent and time-dependent way the platelet aggregation, reduces the viscosity of blood, increases the deformability of red blood cells and increases the cerebral blood flow. Analysis of possible mechanisms of action of VULM 957 indicates that the observed positive haemorheological effects are due to the influence on the fluidity of the platelet and red cell membrane. The increased cerebral blood flow after administration of VULM 957 depends obviously on the reduced viscosity of the blood and the inhibited formation of platelet microaggregates. The presented results justify the assumption that VULM is a perspective substance in the therapy of cerebrovascular diseases.

Amines↗
PubMed1989

[Vascular headache: circulatory, hemorrheologic, electrophysiologic and psychological aspects].

The aim of the work was to analyze circulatory, rheological, electrophysiological and psychological characteristics of patients with vascular headache, mostly migraine and vasomotor cephalea. The group was formed by 69 patients, mean age 40.4 +/- 9.0 years. It was revealed that: 1. there were no significant changes in rheological properties of blood in the following six parameters: coagulation, viscosity of plasma and blood, platelzo aggregation, of circulating aggregates, 2. there were no significant changes in rCBF (FF,SF,AF and ISI) parameters in the group of patients with bilateral headache but a rising rCBF in unilateral headache, 3. there was a significant reduction of the "peak frequency" in supratrochlear arteries and a significant increase of the flow rate in the intracerebral arteries (a.cerebralis media, a.cerebralis anterior), 42.4% of the patients displayed abnormal but non-specific EEg changes, 5. there was a significant increase of the amplitude of P1 and N2 waves of visual evoked potentials and a non-significant shortening of the latency of wave N1, 6. significant changes were recorded in some psychological parameters, in particular an increase of the score of depressivity, anxiety and neuroticism.

Adult↗
PubMed1989

[Optimism or pessimism in the treatment of cerebral infarct].

The aim of the study was to analyse the effects of drug and rehabilitation treatment of cerebral stroke. Material consists of 2,500 patients with focal brain ischemia. About three-fourths (68.7%) of patients with cerebral stroke improved receiving complex drug treatment, rehabilitation and psychological care. 54.9% of the whole group of patients had a neurological deficit score below 150, i.e. more than one half of the whole group (n = 2,500) left the hospital practically in good health capable of carrying on in their original occupation. Only 11.9% of patients died, but 48.9%, i.e. practically one half of them showed an extracerebral cause of death. The results of treatment are dependent on age. In the higher age group, the number of deteriorated cases as well as the number of death increases. The results of treatment are dependent on an early initiation of treatment after the onset of brain ischemia. In the 2nd time-period, the results of treatment are better in comparison to the 1st period due to new strategies of treatment, i.e. due to drugs that improve heart failure, rheological properties of the blood and brain metabolism and due to intensive rehabilitation care. The results have shown the improvement not only in movement possibilities of the patients, but also the improvement in majority of the psychological parameters (IQ, emotionality, sociability scale etc.).

Aged↗
PubMed1989

[Is the effect of naloxone on cerebral circulation mediated by blood platelets?].

In an attempt to elucidate the mechanism of action of the opiate antagonist, naloxone, on the cerebral circulation the authors investigated changes of thrombocyte aggregation in whole blood (impedance aggregometry) and in the regional cerebral blood flow (hydrogen "wash-out" method) after a single dose of naloxone (1 mg/kg) to intact gerbils and gerbils with hemispheric cerebral ischemia. Under physiological conditions naloxone significantly reduced the cerebral blood flow and at the same time increased platelet aggregation. Under conditions of hemispheric cerebral ischemia naloxone increased the blood flow but did not affect the platelets activated by ischemia. The authors assume that naloxone induced hyperaggregation of platelets is at least partly responsible for the reduced cerebral blood flow after naloxone administration to intact animals. The favourable effect of naloxone on the ischemic cerebral circulation is, however, certainly not mediated by the effect on the platelet activity.

Animals↗
PubMed1988

Are blood platelets involved in the pathogenesis of ischemic brain edema in gerbils?

Edema formation following severe permanent or temporary cerebral ischemia in gerbils with an artificially reduced platelet count was investigated. Acute focal cerebral ischemia was produced by extracranial carotid ligation, and the local cerebral blood flow was estimated using the hydrogen clearance method. Brain tissue water and sodium and potassium contents were taken as indexes of brain edema. The platelet count was reduced in some gerbils by intravenous injection of neuraminidase. After 60 minutes of ischemia, a marked increase in tissue water and sodium contents accompanied by a decrease in potassium content was observed in untreated gerbils. However, gerbils with a reduced platelet count revealed similar but significantly smaller changes in all the measured parameters. Restoration of blood flow after 60 minutes of ischemia resulted in further accumulation of water and sodium and in depletion of potassium in both groups. These changes were significantly smaller in the gerbils with a reduced platelet count. It is concluded that platelets, activated by cerebral ischemia, may be involved in the development of ischemic brain edema in gerbils.

Animals↗
PubMed1986

Dual effect of naloxone on blood platelet aggregation and cerebral blood flow in gerbils.

The effect of naloxone on blood platelet aggregation and cerebral blood flow in gerbils was studied. Administration of naloxone in dose 1 mg/kg to intact gerbils resulted in a marked increase in platelet aggregability accompanied by 27% reduction in cerebral blood flow. Focal cerebral ischemic injury significantly enhanced platelet aggregatory response and treatment with naloxone was without any additional effect on platelet aggregation. Cerebral blood flow in ischemic hemisphere, however, increased following naloxone injection by 46%. In vitro naloxone in millimolar concentrations inhibited platelet aggregation in a dose-dependent way. Apparent decrease in fluorescence of platelet membranes tagged with fluorescence probe due to naloxone suggests conformational changes in platelet membrane as a primary mechanism for the antiaggregatory effect of naloxone in vitro.

Animals↗
PubMed1986

Whole-blood red blood cell aggregometer for human and feline blood.

A whole-blood aggregometer of red blood cells (RBC) is described. It consists of a transparent 0.26-cm ID vinyl tube of approximately 30 cm in length containing freshly drawn heparinized blood and a densitometer head that is attached to the tube. The densitometer head consists of an infrared light source of gallium arsenide and a light detector (silicon photodiode) to monitor changes in optical density of the blood in the tube. The tube and densitometer head were installed in a temperature-controlled box at 37 degrees C. The blood in the tube was first subjected to rapid flow with a solenoid so that the wall shear rate of the blood was approximately 500 s-1. The shear gave rise to a rapid increase in optical density of the blood due to dispersion of the blood corpuscles. The blood was then brought abruptly to a full stop. After the flow had stopped the densitometer head revealed a gradual decrease in optical density in association with RBC aggregate formation. The resultant pattern was termed by us an "RBC aggregogram." The RBC aggregogram exhibited an exponential decay in its initial part, which was followed by an asymptotic decrease. A simple mathematical procedure was employed to calculate the rate constant of the initial decrease from the two values on the RBC aggregogram at 10 and 20 s. The rate constant k10 was 0.192 +/- 0.028 (5.2 s as time constant; 3.6 s as half time) for feline blood and 0.129 +/- 0.012 (7.7 s as time constant; 5.3 s as half time) for human blood. The RBC aggregation rate varied linearly with the hematocrit below 40%.

Animals↗
PubMed1982

ON the serotonin liberation from rat platelets due to betaadrenoceptor blocking drugs.

The liberation of 14C-5HT and adenine nucleotides from rat platelets due to 10 betaadrenoceptor blocking drugs was studied. The most effective in liberating of 14C-5HT was pricoron, the less effective was atenolol. Except for pricoron all BAB drugs did not liberate adenine nucleotides from platelets. The depletion of adenine nucleotides due to pricoron was dose-dependent. Cold significantly decreased the effect of all betaadrenoceptor blocking drugs on serotonin liberation. The inhibitory effect of tetrodotoxin was evident on the effect of all drugs except of pricoron. Pretreatment of platelets with IAA,KCN, suramin, 5-HT or ASA was without effect. It is evident that most of the betaadrenoceptor blocking drugs liberate 5-HT from rat platelets by mechanism other than release reaction. The liberation induced with pricoron was result of cell lysis.

Adenine Nucleotides↗
PubMedDate not supplied

Effect of long-term administration of stobadine on exploratory behaviour and on striatal levels of dopamine and serotonin in rats and their offspring.

Stobadine (STB), a cardioprotective drug, was evaluated for its effect on the intensity and habituation of exploratory behaviour in open field testing and on the levels of striatal dopamine (DA), serotonin (5-HT) and their metabolites (3,4-dihydroxyphenylacetic acid, homovanillic acid, 5-hydroxyindole-3-acetic acid) in rats and their offspring. Dams were treated by oral gavage with STB (50 mg kg-1) for a total of 56 days from 14 days before mating to day 21 postpartum (pp). The first open field measurements of the dams were performed over 4 days at the beginning of the experiment, the second on days 21-24 pp and the third on days 49-52 pp (recovery period). Their offspring were tested on postnatal (pn) days 30-33 and 60-63. The biochemical analysis (HPLC with electrochemical detection) in the dams was performed at the same time schedule as given for the open field testing, but in their offspring only on pn day 60. Motor activity of the dams was decreased on days 21-24 pp. The increase of motor activity in female offspring was observed on pn days 30-33. Neurochemical analysis of the striatum of the dams revealed a significant increase of the levels of DA, 5-HT and 5-hydroxyindole-3-acetic acid. In male offspring the levels of DA were significantly decreased, whereas in females the levels were increased. These results suggest that maternal administration of STB resulted both in dams and their offspring in minor alterations in spontaneous behaviour components and changes in the dopaminergic and serotonergic system, but without inducing overtly detectable toxicity.

Animals↗