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F F Carvalho

Publications and source records attributed to F F Carvalho.

5 recordsLinked to original sources
PubMed2000

Neurotoxic effects of three fractions isolated from Tityus serrulatus scorpion venom.

Scorpion venoms contain low molecular weight basic polypeptides, neurotoxins, that are the principal toxic agents. These toxins act on ion channels, promoting a derangement that may result in an abnormal release of neurotransmitters. In the present study we investigated some of the effects of the F, H and J fractions isolated from Tityus serrulatus scorpion venom on the central nervous system of rodents. The venom was partially purified by gel filtration chromatography. The neurotoxic effect of these fractions was studied on convulsive activity after intravenous injection, and on electrographic activity and neuronal integrity of rat hippocampus when injected directly into this brain area. The results showed that intravenous injection of the F and H fractions induced convulsions, and intrahippocampal injection caused electrographic seizures in rats and neuronal damage in specific hippocampal areas. Fraction J injected intravenously reduced the general activity of mice in the open field but induced no changes when injected into the brain. These results suggest that scorpion toxins are able to act directly on the central nervous system promoting behavioural, electrographic and histological modifications.

Animals↗
PubMed1998

Behavioral, electroencephalographic, and histopathologic effects of a neuropeptide isolated from Tityus serrulatus scorpion venom in rats.

The effects of intrahippocampal administration of a neuropeptide (TS-8F toxin) isolated from Tityus serrulatus scorpion venom have been determined on behavior, limbic seizures, and neuronal degeneration in rats. Behavioral observation showed orofacial automatism, wet dog shakes, and myoclonus. Concomitantly, the electroencephalographic record showed high-frequency and high-voltage spikes that evolved to seizure activity in the hippocampus and cortex. Seven days after TS-8F toxin microinjection, neuronal damage was observed in CA1 and CA2 pyramidal cells and in granular cells of the dentate gyrus. The results suggest that TS-8F toxin may be responsible, at least in part, by the epileptic effects observed with the crude venom. Thus, this toxin may be a useful tool in the study of some neurobiological process.

Amino Acid Sequence↗
PubMedDate not supplied

Nickel contact dermatitis in Fortaleza, Ceará, Brazil (1993-1994).

This work consists in an evaluation of the occurrence of nickel contact dermatitis, its distribution between sexes and in which parts of the body the dermatitis usually occurs. It was accomplished a two year (1994-1995) retrospective study of 404 patch-tested patients which had previous clinical diagnosis of contact dermatitis. The occurrence of nickel sensitization was 19.8%, 88.8% of these 19.8% were women and the rest, 11.2%, were men. The lesions were present predominantly on hands, forearms, earlobes and feet. The authors comment about possible variations of occurrence of nickel contact dermatitis in rural areas and/or tropical countries.

Brazil↗