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Biomedical subjects

C Antoniades

Publications and source records attributed to C Antoniades.

4 recordsLinked to original sources
PubMed2005

Effects of atorvastatin on reactive hyperaemia and the thrombosis-fibrinolysis system in patients with heart failure.

OBJECTIVE: To investigate the effects of short term atorvastatin treatment on forearm vasodilatory response to reactive hyperaemia (RH%) and on components of the thrombosis-fibrinolysis system (antithrombin III, proteins and S, factors V and VII, von Willebrand factor, tissue plasminogen activator (tPA), and plasminogen activator inhibitor (PAI-1)) in patients with heart failure. PATIENTS AND METHODS: 35 patients with heart failure were enrolled in this study; 17 patients received atorvastatin 10 mg/day and 18 patients received no statin for four weeks. Forearm blood flow (FBF) was measured by venous occlusion strain gauge plethysmography. RH% and forearm vasodilatory response to nitrate were defined as the percentage change of FBF from rest to the maximum flow during reactive hyperaemia and after nitrate administration, respectively. Plasma concentrations of antithrombin III, protein C, protein S, factor V, factor VII, von Willebrand factor, tPA, and PAI-1 were determined before and after treatment. RESULTS: Maximum hyperaemic FBF remained unchanged in both groups. Baseline FBF was slightly but not significantly decreased in the atorvastatin treated group. RH% was significantly increased only in the atorvastatin treated group, from mean (SD) 42.44 (18.9)% to 83.7 (36.1)% (p < 0.01). Plasma concentrations of antithrombin III (from mean (SD) 81.7 (11.37)% to 73.5 (13.8)%), protein C (from mean (SD) 88.3 (26.9)% to 63.9 (25.0)%), factor V (from mean (SD) 126.2 (33.4)% to 94.9 (29.8)%), tPA (from median (25th-75th percentile) 11.68 (8.60-20.95) ng/ml to 10.30 (8.65-15.12) ng/ml), and PAI-1 (from median (25th-75th percentile) 3.10 (2.15-4.40) IU/l to 1.90 (0.75-3.0) IU/l) were significantly decreased in the atorvastatin treated group (p < 0.05) but not in the control group. Plasma concentrations of von Willebrand factor, factor VII, and protein S remained unaffected in both groups. CONCLUSION: Atorvastatin did not change the maximum hyperaemic flow, although it decreased plasma concentrations of antithrombin III, protein C, factor V, tPA, and PAI-1 in patients with heart failure. Therefore, short term treatment with atorvastatin may affect the expression of both endothelium and liver derived components of the thrombosis-fibrinolysis system in patients with heart failure.

Aged↗
PubMed2005

Effects of vitamin C on intracoronary L-arginine dependent coronary vasodilatation in patients with stable angina.

OBJECTIVE: To assess the effects of intravenous vitamin C administration on the vasomotor responses to intracoronary L-arginine infusion in epicardial coronary arteries. METHODS: 28 patients with coronary artery disease and stable angina were enrolled in the study. Eight patients received intracoronary infusions of 150 micromol/min L-arginine before and after intravenous infusion of vitamin C, 10 patients received intracoronary infusions of 150 micromol/min L-arginine before and after intravenous infusion of normal saline, and 10 patients received intracoronary normal saline before and after intravenous infusion of vitamin C. The diameter of proximal and distal coronary artery segments was measured by quantitative angiography. RESULTS: Infusion of L-arginine caused significant dilatation of both proximal (4.87 (0.96)%, p < 0.01 v normal saline) and distal (6.33 (1.38)%, p < 0.01 v normal saline) coronary segments. Co-infusion of vitamin C and L-arginine dilated proximal coronary segments by 8.68 (1.40)% (p < 0.01 v normal saline, p < 0.01 v L-arginine) and distal segments by 13.07 (2.15)% (p < 0.01 v normal saline, p < 0.01 v L-arginine). Intravenous infusion of vitamin C caused a borderline increase in proximal and distal coronary segment diameters (1.93 (0.76)% and 2.09 (1.28)%, respectively, not significant). CONCLUSIONS: L-arginine dependent coronary segment vasodilatation was augmented by the antioxidant vitamin C in patients with coronary artery disease. Thus, vitamin C may have beneficial effects on nitric oxide bioavailability induced by L-arginine.

Angina Pectoris↗
PubMed2004

Vascular endothelium and inflammatory process, in patients with combined Type 2 diabetes mellitus and coronary atherosclerosis: the effects of vitamin C.

AIMS: Type 2 diabetes mellitus (DM) and coronary artery disease (CAD) are both associated with endothelial dysfunction and elevated oxidative and inflammatory state. We examined the effect of vitamin C on endothelial function and levels of soluble vascular cell adhesion molecule (sVCAM-1), interleukin-6 (IL-6) and tumour necrosis factor (TNF-alpha), in DM patients with or without CAD and in non-diabetic subjects. METHODS: Thirty-seven patients with DM + CAD, 17 patients with DM without CAD and 21 non-diabetic subjects were divided into groups receiving vitamin C 2 g/day or no anti-oxidant for 4 weeks. Forearm blood flow was determined using venous occlusion gauge-strain plethysmography. Forearm vasodilatory response to reactive hyperemia was considered as index of endothelium-dependent dilation. RESULTS: Baseline levels of IL-6 and TNF-alpha were significantly higher in patients with DM + CAD compared with patients with DM (P < 0.01) or non-diabetic subjects (P < 0.01). IL-6 and TNF-alpha levels were also higher in DM compared with non-diabetic subjects (P < 0.05). sVCAM-1 levels were lower in non-diabetic controls compared with DM + CAD (P < 0.05) or DM (P < 0.05). Reactive hyperaemia was higher in non-diabetic controls compared with DM + CAD (P < 0.001) or DM (P < 0.001). Vitamin C significantly increased reactive hyperaemia only in the DM + CAD group, while it had no effect on serum levels of sVCAM-1, TNF-alpha and IL-6 in any of the groups. CONCLUSIONS: Type 2 diabetes mellitus is associated with impaired endothelial function and increased levels of TNF-alpha, IL-6 and sVCAM-1, especially in patients with DM and CAD. Vitamin C significantly increased forearm vasodilatory response to reactive hyperaemia only in patients with combined DM and CAD.

Antioxidants↗