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Biomedical subjects

G Faure

Publications and source records attributed to G Faure.

At least 235 records · Page 13Linked to original sources
PubMed1976

[Interaction of salicyl compounds and other non-steroidal anti-inflammatory agents: pharmacokinetic study of phenylbutazone-aspirin combination in man].

The pharmacodynamic interaction between phenybutazone and aspirin was studied in 9 patients. The levels of phenylbutazone were estimated by gas-chromatography and verified by mass-spectrometry. When phenylbutazone was administered together with salicylates a decrease in the bioavailability of phenylbutazone was demonstrated, but there was no significant variation in the absorption and elimination constants or in the half-life. The variations were much less than those observed with other nonsteroid anti-inflammatory drugs (indometacine, naproxen, fenoprofen). These interactions must be taken into account in the long-term treatment of cases of inflammatory rheumatism.

Adult↗
PubMedDate not supplied

Evidence for the role of ammonia in the intracerebral transfer and metabolism of tryptophan.

After portacaval shunt in the rat, the transport of tryptophan and other neutral amino acids across the blood-brain barrier is enhanced. To determine the role of NH3 in the intracerebral transfer of tryptophan and serotonin metabolism, solutions containing either saline or NH3 or tryptophan or NH3 + tryptophan together were infused, respectively, into the internal carotid artery of rats in order to achieve blood levels similar to those observed after liver ischemia. After tryptophan infusion, a significant increase in the hypothalamic levels of tryptophan and 5-hydroxyindoleacetic acid was observed. A similar increment was found after NH3 infusion. NH3 + tryptophan infusion induced a significant increment in hypothalamic tryptophan and 5-hydroxyindoleacetic acid levels which were 2-fold greater than after tryptophan infusion. There was no significant change in 5-hydroxytryptamine levels in any of these experiments. Glutamine levels increased significantly after NH3 infusion. When tryptophan and NH3 were infused simultaneously, a significant reduction in glutamine levels occurred. These results cannot be explained by any modification of cerebral blood flow nor of the cerebral intercellular pH. Our data suggest that NH3 enhances the transfer of tryptophan across the blood-brain barrier and thus stimulates serotonin metabolism. The mechanism by which tryptophan transfer across the blood-brain barrier is facilitated is unknown. The reduction in glutamine levels in the hypothalamus when NH3 and tryptophan are infused together may be explained either by an inhibition of synthesis or by an intercellular influx of neutral amino acids and an efflux of glutamine as suggested by James et al.

Amino Acids↗
PubMedDate not supplied

Decrease of in vitro serum protein binding of salicylate in rheumatoid arthritis.

Free and bound fractions of salicylates were separated by equilibrium dialysis and measured by spectrofluorimetry in 27 patients with rheumatoid arthritis and in 16 controls. The results showed that in patients with rheumatoid arthritis, the binding of salicylate to proteins decreased in an overproportional manner with the decrease of serum albumin concentrations. This phenomenon was linked with the severity of the inflammatory syndrome. The saturation binding capacity per unit of protein concentration was lower in the patients suffering from active forms of the condition, a finding which suggests that the changes observed are not due only to quantitative changes in the serum albumins. This study confirms the importance of determining free salicylate concentrations in the treatment of patients with inflammatory diseases.

Adolescent↗
PubMedDate not supplied

Immunochemical analysis of a snake venom phospholipase A2 neurotoxin, crotoxin, with monoclonal antibodies.

Crotoxin is the major neurotoxic component of the venom of the South American rattlesnake, Crotalus durissus terrificus. The crotoxin molecule is composed of two subunits: a basic and weakly toxic phospholipase A2 (PLA2) called component-B (CB), and an acidic, nonenzymatic and nontoxic subunit called component-A (CA). Crotoxin exists as a mixture of several isoforms (or variants) resulting from the association of several subunit isoforms. We prepared monoclonal antibodies (MAbs) against each isolated subunit. Six anti-CA MAbs and eight anti-CB MAbs were tested for their cross-reactivities with each subunit and with other toxic and nontoxic PLA2s. Four of the six anti-CA MAbs cross-reacted with CB, whereas only one of the eight anti-CB MAbs cross-reacted with CA. Two anti-CB MAbs were found to cross-react with agkistrodotoxin, a single chain neurotoxic PLA2 purified from the venom of Agkistrodon blomhoffii brevicaudus. We determined the dissociation constants of each MAb for CA and CB isoforms and their capacities to neutralize the lethality and to inhibit the catalytic activity of crotoxin. We defined three epitopic regions on CA and four on CB, and used a schematic representation of the two subunits to characterize these epitopic regions with respect to: (1) the "toxic" and the "catalytic" sites of CB, and (2) the zone of interaction between the two subunits. We propose three-dimensional structures of the crotoxin subunits in which we localize amino acid residues that might be involved in the epitopic regions described here.

Amino Acid Sequence↗