Biomedical subjects

L Vécsei

Publications and source records attributed to L Vécsei.

113 records · Page 7Linked to original sources

PubMedDate not supplied

Cysteamine and pantethine effects on passive avoidance behavior, shuttle box learning, open-field activity, striatal catecholamines and somatostatin.

The effects of cysteamine and pantethine were compared on different behavioral tests and neurochemical parameters in rats. Cysteamine, administered in high dose (3.90 mM/kg s.c.), decreased the locomotor and rearing activities of rats, while it slightly but not significantly increased the avoidance latency in a passive avoidance test. Pantethine, 24 hr after its administration, significantly increased the dihydroxyphenyl acetic acid (DOPAC) levels in the striatum. Cysteamine slightly reduced the DOPAC level without influencing the catecholamine levels in this brain area. The striatal somatostatin concentration was reduced 24 hr after the administration of cysteamine, while pantethine did not influence it. After repeated daily injections of pantethine, the drug facilitated the shuttle box learning process and increased the intertrial and open-field activities of the animals. Cysteamine only slightly increased the locomotion and rearing and did not influence the shuttle box learning. Both pantethine and cysteamine slowed the rate of the "body weight increase" of the animals when compared to a saline-treated group. These findings suggest that the locomotor activation induced by pantethine 24 hr after its administration plays an important role in its behavioral effects. It might be that the striatal dopaminergic transmission, modified by administration of pantethine, plays some role in the higher locomotor activity induced by the substance.

3,4-Dihydroxyphenylacetic Acid↗

PubMedDate not supplied

Effects of pantethine, cysteamine and pantothenic acid on open-field behavior and brain catecholamines in rats.

Cysteamine (1.95 mM/kg) markedly decreased the locomotor, rearing and grooming activities, as well as the number of defecation boluses in an open-field test. An equimolar dose of pantethine reduced the locomotor activity to a lesser extent, but has the same potency in decreasing the number of defecation boluses, whereas pantothenic acid did not affect the behavior of the rats. Cysteamine, and to a lesser extent pantethine, reduced the noradrenaline and increased the dopamine and DOPAC concentrations in the hypothalamus. Pantothenic acid itself did not influence the hypothalamic catecholamine concentrations. These results suggest that the lower efficacy of pantethine compared to cysteamine on both behavioral and neurochemical parameters is probably due to a rate-limiting activity of the enzyme pantetheinase in the conversion of pantetheine to cysteamine.

3,4-Dihydroxyphenylacetic Acid↗

PubMedDate not supplied

Chronic recurrent transverse myelitis or multiple sclerosis.

The simultaneous occurrence of multiple sclerosis and transverse myelitis is known in the literature. Apart from the spinal symptoms, other neurological signs of brain involvement are usually found and magnetic resonance imaging (MRI) reveals disseminated foci in the brain. The positive evoked responses, the immunological abnormalities of the cerebrospinal fluid (CSF), and the oligoclonality together prove the presence of multiple sclerosis. In these cases the symptoms of transverse myelitis can separately precede other signs of multiple sclerosis, or appear as a relapse. Recurrent transverse myelitis as an independent entity, with negative MRI and CSF immunology, is an exciting topic in terms of the etiological factors and therapeutic considerations. The view in the literature is that the occurrence of transverse myelitis as an independent entity is rather rare. The present article reports the case of a female patient with recurrent spinal cord signs, and negative MRI and CSF immunology. During a ten-year follow-up observation period, symptoms of multiple sclerosis did not develop. Further studies of such cases are needed in order to clarify the etiological factors, the pathomechanism and the therapeutic considerations relating to this relatively new and probably independent clinical entity.

Adult↗

PubMedDate not supplied

Neuroborreliosis in county Baranya, Hungary.

The incidence and clinical characteristics of Lyme neuroborreliosis (NB) in a region of high prevalence of tick-bite in Hungary is described. In the county Baranya 66 patients were recorded in a five-year period (1989-93). Fifty-six patients (85%) were in "early", and 10 patients (15%) in "late stage" of NB. The sex distribution was equal. The incidence of NB was 2.9-100,000/year in this region. The incidence of radiculitis/neuritis, meningitis, encephalitis and myelitis in the sample was 56.1%, 19.7%, 18.2% and 6%, respectively. The EEG and evoked potentials showed both central and peripheral neural involvement, EMG and ENG abnormalities were related to the peripheral clinical signs. Non-specific white matter lesions could be found by MRI in 5 patients with central involvement. Cerebrospinal fluid changes were not obligatory but a better indicator of inflammatory process in cases with meningitis and/or encephalitis forms (positivity 75%) than in cases with myelitis and radiculitis (positivity 49%).

Adolescent↗

PubMedDate not supplied

Neurotoxins and neurodegenerative disorders.

There is a hypothesis that excitotoxic pathomechanisms underlie neuronal tissue degeneration in neurological disorders. It is proposed that target neurons are overexcited, the result being energy disturbance and pathobiochemical changes that culminate in nerve cell death. Domoic acid (structural analogue of kainic acid) and beta-N-oxalylamino-L-alanine (BOAA) are powerful excitotoxins. Diminished energy supplies may result either in excessive release of glutamate or an inability of the neuron to restore ionic balance after stimulation. Impairment of intracellular energy metabolism induced by cyanide, amino-oxyacetic acid (AOAA), 3-acetylpiridine, thiamine deficiency, azide, 3-nitropropionic acid, methyl-phenyltetrahydro-pyridinum ion (MPP+), carbon monoxide, methanol intoxication and manganese (Mn) is discussed. Furthermore, the endogenous substance kynurenine is metabolised to kynurenic acid (excitotoxin antagonist) and quinolinic acid (excitotoxin agonist) Probenecid (inhibitor of kynurenic acid excretion from the extracellular fluid) has an antiexcitatory effect.

Animals↗