ISSN:0009-7322    

出版商:OVID    

年代:2003

数据来源: OVID

ISSN:0009-7322    

出版商:OVID    

年代:2003

数据来源: OVID

ISSN:0009-7322    

出版商:OVID    

年代:2003

数据来源: OVID

ISSN:0009-7322    

出版商:OVID    

年代:2003

数据来源: OVID

ISSN:0009-7322    

出版商:OVID    

年代:2003

数据来源: OVID

ISSN:0009-7322    

出版商:OVID    

年代:2003

数据来源: OVID

摘要:

Background—Drug-induced QT prolongation and torsades de pointes remain significant and often unpredictable clinical problems. Current in vitro preclinical assays are limited by biological simplicity, and in vivo models suffer from expense and low throughput.Methods and Results—During a screen for the effects of 100 small molecules on the heart rate of the zebrafish,Danio rerio, we found that drugs that cause QT prolongation in humans consistently caused bradycardia and AV block in the zebrafish. Of 23 such drugs tested, 18 were positive in this initial screen. Poor absorption explained 4 of 5 false-negative results, as demonstrated by microinjection. Overall, 22 of 23 compounds that cause repolarization abnormalities were positive in this assay. Antisense “knockdown” of the zebrafish KCNH2 ortholog yielded bradycardia in a dose dependent manner confirming the effects of reduction of repolarizing potassium current in this model. Classical drug-drug interactions between erythromycin and cisapride, as well as cimetidine and terfenadine, were also reproduced.Conclusion—This simple high-throughput assay is a promising addition to the repertoire of preclinical tests for drug-induced repolarization abnormalities. The genetic tractability of the zebrafish will allow the exploration of heritable modifiers of such drug effects.

ISSN:0009-7322    

出版商:OVID    

年代:2003

数据来源: OVID

摘要:

Background—Recombinant human vascular endothelial growth factor protein (rhVEGF) stimulates angiogenesis in animal models and was well tolerated in Phase I clinical trials. VIVA (Vascular endothelial growth factor in Ischemia for Vascular Angiogenesis) is a double-blind, placebo-controlled trial designed to evaluate the safety and efficacy of intracoronary and intravenous infusions of rhVEGF.Methods and Results—A total of 178 patients with stable exertional angina, unsuitable for standard revascularization, were randomized to receive placebo, low-dose rhVEGF (17 ng · kg−1· min−1), or high-dose rhVEGF (50 ng · kg−1· min−1) by intracoronary infusion on day 0, followed by intravenous infusions on days 3, 6, and 9. Exercise treadmill tests, angina class, and quality of life assessments were performed at baseline, day 60, and day 120. Myocardial perfusion imaging was performed at baseline and day 60. At day 60, the change in exercise treadmill test (ETT) time from baseline was not different between groups (placebo, +48 seconds; low dose, +30 seconds; high dose, +30 seconds). Angina class and quality of life were significantly improved within each group, with no difference between groups. By day 120, placebo-treated patients demonstrated reduced benefit in all three measures, with no significant difference compared with low-dose rhVEGF. In contrast, high-dose rhVEGF resulted in significant improvement in angina class (P=0.05) and nonsignificant trends in ETT time (P=0.15) and angina frequency (P=0.09) as compared with placebo.Conclusions—rhVEGF seems to be safe and well tolerated. rhVEGF offered no improvement beyond placebo in all measurements by day 60. By day 120, high-dose rhVEGF resulted in significant improvement in angina and favorable trends in ETT time and angina frequency.

ISSN:0009-7322    

出版商:OVID    

年代:2003

数据来源: OVID

摘要:

Background—Prospective studies have examined the relationship between coronary artery disease and low plasma levels of high-density lipoprotein cholesterol (HDL-C).Methods and Results—We investigated the causes of hypoalphalipoproteinemia (HypoA; HDL-C <5th percentile) in 64 subjects (12 women and 52 men). Apolipoprotein AI–mediated cellular cholesterol and phospholipid efflux were measured in fibroblasts from HypoA subjects, 9 controls, 2 patients with Tangier disease, and 5 patients with hyperalphalipoproteinemia. A phospholipid efflux defect was defined as <70% of controls. Mean HDL-C was 0.49±0.21 mmol/L. Cholesterol and phospholipid efflux correlated strongly (r=0.72,P<0.001). Phospholipid efflux and HDL-C (r=0.64,P<0.001) correlated in HypoA subjects. However, phospholipid or cholesterol efflux was no longer a determinant of HDL-C levels at higher levels (>≈1.0 mmol/L) of HDL-C. In HypoA subjects, 4 cases of Tangier disease and 6 of familial HDL deficiency (heterozygous Tangier disease) were identified (10 of 64; 16%). In the remaining 54 subjects, mean lipid efflux was not significantly different from controls and subjects with hyperalphalipoproteinemia. A phospholipid efflux defect was identified in 7 additional HypoA subjects, and a cholesterol efflux defect was detected in 11 subjects. In 2 of these subjects, the ABCA1 gene was ruled out as the cause of the efflux defect, while in 3, the low HDL-C trait segregated with the ABCA1 gene locus.Conclusions—Lipidation of lipid-poor apolipoprotein AI may not be a major determinant of cholesterol accumulation within more mature HDL particles and increasing cholesterol or phospholipid efflux beyond normal levels may not lead to increase in plasma HDL-C levels. ABCA1 is essential in the initial steps of HDL formation but other plasma events are major modulators of HDL-C levels.

ISSN:0009-7322    

出版商:OVID    

年代:2003

数据来源: OVID

摘要:

Background—Few studies have examined associations of fish consumption with ischemic heart disease (IHD) risk among older adults or how different types of fish meals relate to IHD risk.Methods and Results—In a population-based prospective cohort study, usual fish consumption was ascertained at baseline among 3910 adults aged ≥65 years and free of known cardiovascular disease in 1989 and 1990. Consumption of tuna and other broiled or baked fish correlated with plasma phospholipid long-chain n-3 fatty acids, whereas consumption of fried fish or fish sandwiches (fish burgers) did not. Over 9.3 years’ mean follow-up, there were 247 IHD deaths (including 148 arrhythmic deaths) and 363 incident nonfatal myocardial infarctions (MIs). After adjustment for potential confounders, consumption of tuna or other broiled or baked fish was associated with lower risk of total IHD death (Pfor trend=0.001) and arrhythmic IHD death (P=0.001) but not nonfatal MI (P=0.44), with 49% lower risk of total IHD death and 58% lower risk of arrhythmic IHD death among persons consuming tuna/other fish 3 or more times per week compared with less than once per month. In similar analyses, fried fish/fish sandwich consumption was not associated with lower risk of total IHD death, arrhythmic IHD death, or nonfatal MI but rather with trends toward higher risk.Conclusions—Among adults aged ≥65 years, modest consumption of tuna or other broiled or baked fish, but not fried fish or fish sandwiches, is associated with lower risk of IHD death, especially arrhythmic IHD death. Cardiac benefits of fish consumption may vary depending on the type of fish meal consumed.

ISSN:0009-7322    

出版商:OVID    

年代:2003

数据来源: OVID