PubMed Health⌕ Search

Biomedical subjects

K Felice

Publications and source records attributed to K Felice.

5 recordsLinked to original sources
PubMed2001

GABA and the ornithine delta-aminotransferase gene in vigabatrin-associated visual field defects.

Vigabatrin use in some epilepsy patients has been associated with persistent visual field constriction and retinal dysfunction. The mechanism is unknown, but could be related to vigabatrin, chronic epilepsy, GABA toxicity, or the effect of a metabolite in combination with a predisposing genotype. The aim of this study was to investigate the latter two hypotheses. Levels of brain gamma-aminobutyric acid (GABA) measured by nuclear magnetic resonance spectroscopy were similar in subjects taking vigabatrin who developed visual field constriction and those who did not. We tested whether allelic heterogeneity of the ornithine aminotransferase gene occurs in the affected patients. No clinically significant mutation was detected, although a common intronic polymorphism was identified.

Anticonvulsants↗
PubMed1999

Active intestinal elimination of ciprofloxacin in rats: modulation by different substrates.

1. Two in vivo models, in the rat, were used to investigate, in the presence of different substrates, the overall and net intestinal elimination of ciprofloxacin: an open-intestinal perfusion model and an intestinal loop model respectively. 2. In the presence of quinidine, verapamil and cyclosporin (substrates of the P-glycoprotein (P-gp)), plasma AUCs of ciprofloxacin were 1.5 - 2 fold increased, while biliary clearance (1.5 - 2 fold), intestinal overall and net clearances (2 - 4 fold and 1.5 - 8 fold respectively) decreased. The weak effect obtained with cyclosporin as compared to verapamil and especially quinidine, suggests, for ciprofloxacin, the existence of transport systems distinct from the P-gp, as the OCT1 transporter which could be inhibited by quinidine. 3. With cephalexin and azlocillin, two beta-lactam antibiotics, plasma AUCs of ciprofloxacin increased and biliary and intestinal overall clearances decreased in a similar fashion (1.3 - 2 fold), suggesting the involvement of organic anion and/or cation transporters. 4. In the presence of structural analogues, the effect was dependent on the compound administered: Sparfloxacin had no effect on intestinal clearance of ciprofloxacin. In contrast, with pefloxacin, overall intestinal clearance of ciprofloxacin was decreased and net intestinal clearance increased. 5. The specificity of ciprofloxacin intestinal transport appears to be different from P-gp as outlined by the lack of competition with sparfloxacin, a P-gp substrate. Ciprofloxacin intestinal elimination seems to be mediated by organic anion and/or cation transporters and a mechanism sensitive to quinidine and verapamil.

Animals↗