Tadeusz Tomas

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We investigated the effect of acute exposure to chlorphenvinphos (CVP) (2-chloro-1 (2,4-dichlorophenyl)-vinyl-diethyl-phosphate), an organophosphate anticholinesterase, on the amphetamine- and scopolamine-induced open-field locomotion in Wistar rats. CVP was administered at a single i.p. dose of 1.0 mg/kg (1/10 of LD50). In part of the rats cholinesterase(More)
Two plants, Spirostachys africana and Bridelia cathartica, were selected for investigation on the basis of a clinical study of four herbal antimalarial remedies used in southern Mozambique. Petroleum ether, ethanol and aqueous extracts were tested for activity in vitro against Plasmodium falciparum. Crude ethanolic and aqueous extracts of the root and the(More)
It has been hypothesized that exposure to neurotoxins may result in accelerated ageing of the central nervous system (CNS). The present study investigated the effects of a 3-month (6 hr daily, 5 days/week) inhalation exposure of rats to m-xylene, at concentrations of 100 and 1000 ppm, on the spontaneous neocortical spike and wave discharges (SWD) and(More)
The relationship between neocortical high voltage spindle activity (HVS) and the level of arousal (state of vigilance) was investigated in imp-DAK rats. Two groups of single records (6 h and 24 h) and one group of repeated ones (6 h daily for three consecutive days) were analysed. Five levels of arousal (states) were distinguished on the basis of(More)
This study was performed to find out whether repeated exposure to toluene might lead to behavioural sensitization estimated on the basis of spontaneous locomotor activity of rats in an open field. As a reference compound amphetamine was used. Toluene at a dose of 740 mg/kg was administered orally, amphetamine at a dose of 1 mg/kg was administered(More)
Toluene is a major component of numerous commercial organic solvent formulations. It is often listed among the chemicals capable of producing the organic solvent syndrome and a neurobehavioral hypersensitivity condition. The hypersensitivity condition (continued long-term intensification of some behavioral reactions in response to pharmacological or(More)
Pseudocumene (1,2,4-trimethylbenzene, TMB) is a component of several solvent mixtures. During recent studies on rats we investigated the effect of a 4-week (6 h/day, 5 days/week) inhalation exposure to TMB at concentrations of 0, 25, 100, or 250 ppm on radial maze performance, open field activity, passive avoidance, active two-way avoidance, and(More)
Our earlier experiment revealed that rats pretreated once with an anticholinesterase develop hyposensitivity to amphetamine (AMPH). One of the likely causes of this effect might be a transient hyperexcitation of the central muscarinic receptors. It has appeared, however, that rats pretreated with oxotremorine (OX), a muscarinic agonist, show an augmented(More)