Vincent P. Tong

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OBJECTIVE To determine whether valproic acid (VPA) influences urinary levels of 15-F2t -isoprostane (15-F2t -IsoP), a marker of oxidative stress, in children. STUDY DESIGN Morning urine samples were collected from children with epilepsy receiving VPA (n = 25), carbamazepine (n = 16), or clobazam (n = 12) for > or = 4 weeks and from age-matched control(More)
Oxidative stress has been associated with valproic acid (VPA) treatment, and mitochondrial dysfunction has been implicated in the pathogenesis of VPA-idiosyncratic hepatotoxicity. The present study investigated the effect of VPA and the role of GSH on oxidative stress, mitochondrial membrane potential, and toxicity in freshly isolated rat hepatocytes.(More)
The mechanism by which valproic acid (VPA) induces liver injury remains unknown, but it is hypothesized to involve the generation of toxic metabolites and/or reactive oxygen species. This study's objectives were to determine the effect of VPA on plasma and hepatic levels of the F(2)-isoprostane, 15-F(2t)-IsoP, a marker for oxidative stress, and to(More)
Treatment of rats with a single oral dose (10-30 mg/kg) of a crude Panax ginseng extract of unknown ginsenoside content has been reported to modestly increase hepatic microsomal cytochrome P450-mediated aminopyrine N-demethylation activity. In the present study, we compared the effect of P. ginseng and Panax quinquefolius extracts on rat hepatic CYP2B1,(More)
Oxidative stress has been associated with valproic acid (VPA) treatment in rats and studies are ongoing to examine the relationship between VPA biotransformation and the increase in the lipid peroxidation biomarker 15-F2t-isoprostane (15-F2t-IsoP). This study investigated the effects of modulating VPA-1-O-acyl glucuronide (VPA-G) formation on 15-F2t-IsoP(More)
Each year colleges and universities strive to increase their national standing in the academic hierarchy, and the behavior associated with this “striving” has taken many forms. In recent years research has examined the nature of such “striving” to frame how it might be studied, and to examine how striving impacts various aspects of institutional(More)
The present study investigated the role of specific human cytochrome P450 (CYP) enzymes in the in vitro metabolism of valproic acid (VPA) by a complementary approach that used individual cDNA-expressed CYP enzymes, chemical inhibitors of specific CYP enzymes, CYP-specific inhibitory monoclonal antibodies (MAbs), individual human hepatic microsomes, and(More)
A single dose of valproic acid (VPA), which is a widely used antiepileptic drug, is associated with oxidative stress in rats, as recently demonstrated by elevated levels of 15-F(2t)-isoprostane (15-F(2t)-IsoP). To determine whether there was a temporal relationship between VPA-associated oxidative stress and hepatotoxicity, adult male Sprague-Dawley rats(More)
To clarify the mechanism of sensitivity to an endotoxin lipopolysaccharide LPS0111:B4, which causes severe liver injury in a variety of animals, we have developed an in vitro assay to measure Kupffer cell-mediated cytotoxicity in the human liver cell line, WRL68. This assay could detect the decrease in Kupffer cell activity induced by gadolinium chloride(More)
PURPOSE The hepatic extraction of a novel antiarrhythmic, RSD1070, was investigated to test the hypothesis that the poor bioavailability observed in rats is due to high hepatic metabolism. METHODS The pharmacokinetics of RSD1070 was examined in rats (n=8) and its metabolism was investigated using pooled rat hepatic microsomes. The free fraction in plasma(More)