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Mary C DeVoe

Publications and source records attributed to Mary C DeVoe.

7 recordsLinked to original sources

Reactive oxygen species are involved in smoking-induced dysfunction of nitric oxide biosynthesis and upregulation of endothelial nitric oxide synthase: an in vitro demonstration in human coronary artery endothelial cells.

BACKGROUND: Our group has previously shown that human umbilical vein endothelial cells exposed to smokers' serum decreased nitric oxide (NO) production and endothelial nitric oxide synthase (eNOS) activity in the presence of increased eNOS expression. In the present study, we examined whether these observations extended to human coronary artery endothelial cells (HCAECs). In addition, the role of reactive oxygen species in the observed alterations was examined. METHODS AND RESULTS: HCAECs were incubated with serum from 10 nonsmokers and 15 smokers for 12 hours with or without the addition of either polyethylene glycol-superoxide dismutase (PEG-SOD, 300 U/mL), PEG-SOD+PEG-catalase (1000 U/mL), chelerythrine (3 micromol/L), or tetrahydrobiopterin (20 micromol/L). At the end of incubation, NO, eNOS protein, and eNOS activity were measured from the same culture. HCAECs incubated with smokers' serum alone showed significantly lower NO production (P<0.05) and eNOS activity (P<0.005) but higher eNOS expression (P<0.005) compared with nonsmokers. In smokers, addition of PEG-SOD, PEG-SOD+PEG-catalase, or tetrahydrobiopterin significantly (P<0.05) improved NO levels and eNOS activity. Interestingly, in the same smokers, a significant decrease in eNOS expression was only seen with the addition of PEG-SOD+PEG-catalase (P<0.05) and treatment with PEG-SOD alone insignificantly increased eNOS expression. CONCLUSIONS: The present study indicates that in vitro, HCAECs show similar changes in NO biosynthesis as human umbilical vein endothelial cells when exposed to smokers' serum and also confirms that oxidative stress plays a central role in smoking-mediated dysfunction of NO biosynthesis in endothelial cells. Furthermore, these data support other studies suggesting a role for hydrogen peroxide in the upregulation of eNOS.

Adult↗

The impact of plasma levels of C-reactive protein, lipoprotein (a) and homocysteine on the long-term prognosis after successful coronary stenting: The Global Evaluation of New Events and Restenosis After Stent Implantation Study.

OBJECTIVES: The objective of this study was to evaluate the association of high plasma levels of either C-reactive protein (CRP), lipoprotein (a) (Lp[a]) or total homocysteine (tHCY) with the long-term prognosis after successful coronary stenting (CS). BACKGROUND: High plasma levels of either CRP, Lp(a) or tHCY may have an impact in coronary artery disease. However, long-term prospective data after coronary stenting (CS) are limited. METHODS: Four-hundred and eighty-three consecutive patients with either stable or unstable coronary syndromes were followed for up to three years after successful CS. The composite of cardiac death, myocardial infarction or rehospitalization for rest unstable angina, whichever occurred first, was the prespecified primary end point. Moreover, the one-year incidence of clinical recurrence of symptoms, in-stent restenosis (ISR) and progression of atherosclerosis to a significant lesion (PTSL) were additionally evaluated. PTSL was defined as an increase by at least 25% in the luminal diameter stenosis of a known nonsignificant lesion ( or=70% luminal diameter stenosis). RESULTS: By the end of the follow-up, high plasma levels of either CRP or Lp(a) but not tHCY were independently associated with the primary end point. In particular, CRP >or=0.68 mg/dl (p < 0.001) or Lp(a) >or=25 mg/dl (p = 0.003) conferred a significantly increased risk. By 1 year, a CRP >or=0.68 mg/dl conferred a significantly increased risk for clinical recurrence of symptoms (p < 0.001) or PTSL (p < 0.001). None of the studied biochemical markers was related to ISR. CONCLUSIONS: High plasma levels of either CRP or Lp(a) but not tHCY may be associated with a higher incidence of late adverse events after successful CS. PTSL in vessels not previously intervened upon may play a significant role in the underlying pathophysiology as opposed to ISR.

Aged↗

Heavy and light cigarette smokers have similar dysfunction of endothelial vasoregulatory activity: an in vivo and in vitro correlation.

OBJECTIVES: The goal of this study was to investigate the dose-dependent effects of active cigarette smoking on endothelial nitric oxide (NO) and endothelin-1 (ET-1) biosynthesis. BACKGROUND: Limited studies have suggested that active cigarette smoking may be associated with a dose-dependent reduction of endothelium-dependent vasodilation (EDV). The underlying biochemical changes that cause this dose-specific effect, such as changes in the endothelial NO biosynthetic pathway and ET-1 production, have not been examined. METHODS: Flow- and nitroglycerin-mediated reactivity of the brachial artery were measured in eight nonsmokers, seven light smokers (< or =1 pack/week) and eight heavy smokers (> or =1 pack/day), and their sera were added to confluent ( approximately 85%) monolayers of human umbilical endothelial cells (HUVECs) for 12 h. Basal and substance P-stimulated NO and basal ET-1 production were measured. The HUVECs used for measuring basal NO production were lysed, and both endothelial NO synthase (eNOS) protein expression and eNOS activity were determined. RESULTS: Serum cotinine level and pack-years of smoking were significantly lower in light smokers compared with heavy smokers (p < 0.006 and p < 0.004, respectively). There were no significant differences between heavy smokers and light smokers in EDV (p = 0.52), basal- (p = 0.70) and stimulated-NO production (p = 0.95), eNOS protein (p = 0.40) and eNOS activity (p = 0.63). Compared with nonsmokers, all the parameters were significantly altered in both of the smokers' groups. No differences were found in nitroglycerin-mediated vasodilation and in vitro ET-1 production among the three groups. CONCLUSIONS: These results indicate light smoking may have similar detrimental effects on EDV and NO biosynthetic pathway as does heavy smoking. These data may have important implications concerning the amount of active cigarette exposure that imparts cardiovascular risk.

Brachial Artery↗