Dark chocolate improves endothelial and platelet function.
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Biomedical subjects
Publications and source records attributed to R Corti.
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Intake of coffee, one of the most common beverages worldwide, has often been discussed as a potential cardiovascular risk factor. However, definitive data about this topic are missing and newer studies even point out for a favorable rather than hazardous effect. Despite many studies no clear association between coffee and the risk of hypertension, myocardial infarction and other cardiovascular diseases was found. Recent publications suggest that moderate coffee intake does not represent a health hazard, but may even be associated with beneficial effects on the cardiovascular system and diabetes.
For centuries dark chocolate has been known for its taste as well as its beneficial effects on health. Mainly polyphenols, a heterogeneous group of molecules, have been associated with antioxidant and immunomodulatory properties. Furthermore they inhibit primary hemostasis and pathways associated with platelet activation and aggregation.
OBJECTIVE: To investigate the feasibility of targeting various areas of left ventricle myocardium under real time magnetic resonance (MR) imaging with a customised injection catheter equipped with a miniaturised coil. DESIGN: A needle injection catheter with a mounted resonant solenoid circuit (coil) at its tip was designed and constructed. A 1.5 T MR scanner with customised real time sequence combined with in-room scan running capabilities was used. With this system, various myocardial areas within the left ventricle were targeted and injected with a gadolinium-diethylenetriaminepentaacetic acid (DTPA) and Indian ink mixture. RESULTS: Real time sequencing at 10 frames/s allowed clear visualisation of the moving catheter and its transit through the aorta into the ventricle, as well as targeting of all ventricle wall segments without further image enhancement techniques. All injections were visualised by real time MR imaging and verified by gross pathology. CONCLUSION: The tracking device allowed real time in vivo visualisation of catheters in the aorta and left ventricle as well as precise targeting of myocardial areas. The use of this real time catheter tracking may enable precise and adequate delivery of agents for tissue regeneration.
The interaction between the vulnerable atherosclerotic plaque prone to disruption and thrombus formation is the cornerstone of acute coronary syndrome (ACS). Although distinct from one another, the atherosclerotic and thrombotic processes appear to be interdependent, hence the term atherothrombosis. Inflammation is a crucial common pathophysiological mechanism. Overall, the association of plaque vulnerability and ACS has been well documented. Given the multifactorial origin of atherothrombosis the best preventive approach should be aggressive management of all the risk factors. New interventions should be directed toward decreasing vulnerability of the lesions thereby decreasing the risk of ACS.
OBJECTIVE: To show our experience and results in Virtual Colonoscopy (VC). MATERIAL AND METHOD: Five hundred patients with personal or familial history of colorectal carcinoma and/or adenomas, or any kind of coloproctologic symptoms were studied. VCs were practiced using a helical CT scanner (300 patients) and a multislice CT scanner (200 patients) a few hours after Conventional Colonoscopy (CC), considered the gold standard. The patients were evaluated in a prospective blind study, to determine sensitivity and specificity of VC. Findings were classified as: 1) normal studies; 2) studies with pathological findings. This one was subdivided into: 2a) Lesions below 5 mm., 2b) Lesions between 5-9 mm., 2c) Lesions above 9 mm. RESULTS: VC detected 253 normal studies whereas CC only detected 233. The sensitivity and specificity for each subgroup were: 2a) 87.8% and 86.9%; 2b) 95.6% and 91.4%; 2c) 100.0% and 100.0% respectively. CONCLUSION: VC is a feasible and useful method for evaluating the entire colon. It is well tolerated, it has no complications and a high sensitivity and specificity for elevated lesions, especially the ones above or equal to 5 mm.
Primary esophageal lymphomas are extremely rare. We report a primary esophageal T cell lymphoma of a diffuse large cell phenotype B in a patient with AIDS. Also we reviewed other published cases. The diagnosis of this complication should be considered in HIV seropositive patients with progressive displagia and endoscopic findings of masses, polyps or ulcerations and, specially in those unresponsive to antifungal or antiviral therapy. Biopsy and histopathologic studies are needed to confirm the diagnosis.
OBJECTIVE: To compare the acid-supressing capacity of omeprazole (OZ) 20 mg tablets vs pantoprazole (PZ) 20 and 40 mg tablets, in healthy volunteers, with 24-h intragastric pH-metry. MATERIAL AND METHODS: Open, randomized, cross-over trial in 10 healthy volunteers; on days 0.8 and 22, 24-h intragastric pH-metry. Day 0, basal, thereafter 7 days with OZ or PZ 20 mg/day; day 8, pH-metry, then "wash out" for 7 days and thereafter 7 more days' therapy with PZ or OZ. On day 22 a 24-h intragastric pH control was performed again. In the last treatment stage, all of them were administered pantoprazole 40 mg/day for 8 days again with a 24-h pH recording at the end. RESULTS: 24-h pH-metry expressed as the time (hours) in which the pH was < or = 4 and the values as mean +/- standard deviation. BASAL 22.12 +/- 1.54, POST-OZ 9.78 +/- 6.72, POST-PZ 20 15.65 +/- 5.65, POST-PZ 40 8.57 +/- 5.93. Statistical evaluation with two way repeated measures ANOVA p < 0.0001. Newman Keuls post-hoc test: (1) vs (2) p < 0.003; (1) vs (3) p < 0.03; (2) vs (4) 0.65. CONCLUSIONS: According to the results it might be stated that both proton pump inhibitors have acid-supressing capacity and omeprazole in equal dosis is more effective than pantoprazole as acid-supressor, with statistically significative differences. There was no difference between 20 mg omeprazole and 40 mg pantoprazole.
OBJECTIVE: To define the role of virtual gastroscopy (VG) in the detection of elevated lesions comparing its results with conventional endoscopy (CE) as the gold standard method. MATERIALS AND METHODS: Between December 2000 and July 2001, 19 patients were evaluated. The age ranged between 41 and 72 (mean 58.8 years old). VG and CE were performed in all the patients during the same week. VG were carried out with a multislice CT scanner (Mx 8000, Marconi Medical Systems). The technical parameters used were 3 mm with slices and 1.5 mm reconstruction intervals. The acquisition time was 22 seconds. Images were sent to a workstation (MxView, Marconi Medical Systems) where they were reprocessed in three different ways: 1) Bidimensionally 2) Tridimensionally 3) Virtual Endoscopy Findings of VG were compared with CE. RESULTS: VG detected 39 lesions, whereas CE detected 40 lesions. There were 39 true-positive findings, 2 true-negative findings, 0 false-positive findings and 1 false-negative findings. The Sensitivity (Se) was 97.5%; Specificity (Sp) was 100%, positive predictive value 100% and Negative predictive value 66%. CONCLUSIONS: VG is a new non-invasive method with high Se and Sp in the detection of elevated lesions. The actual role of VG consist in identification of gastric lesions and possibility to diagnose gastric disease.
The cardiovascular system is regulated by hemodynamic and neurohumoral mechanisms. These regulatory systems play a key role in modulating cardiac function, vascular tone, and structure. Although neurohumoral systems are essential in vascular homeostasis, they become maladaptive in disease states such as hypertension, coronary disease, and heart failure. The clinical success of ACE inhibitors has led to efforts to block other humoral systems. Neutral endopeptidase (NEP) is an endothelial cell surface zinc metallopeptidase with similar structure and catalytic site. NEP is the major enzymatic pathway for degradation of natriuretic peptides, a secondary enzymatic pathway for degradation of kinins, and adrenomedullin. The natriuretic peptides can be viewed as endogenous inhibitors of the renin angiotensin system. Inhibition of NEP increases levels of atrial natriuretic peptide (ANP), brain natriuretic peptide (BNP) of myocardial cell origin, and C-type natriuretic peptide (CNP) of endothelial cell origin as well as bradykinin and adrenomedullin. By simultaneously inhibiting the renin-angiotensin-aldosterone system and potentiating the natriuretic peptide and kinin systems, vasopeptidase inhibitors reduce vasoconstriction, enhance vasodilation, improve sodium/water balance, and, in turn, decrease peripheral vascular resistance and blood pressure and improve local blood flow. Within the blood vessel wall, this leads to a reduction of vasoconstrictor and proliferative mediators such as angiotensin II and increased local levels of bradykinin (and, in turn, nitric oxide) and natriuretic peptides. Preliminary clinical experiences with vasopeptidase inhibitors are encouraging. Thus, the combined inhibition of ACE and neutral endopeptidase is a new and promising approach to treat patients with hypertension, atherosclerosis, or heart failure.
BACKGROUND: This study was designed to investigate the effects of lipid-lowering by simvastatin on human atherosclerotic lesions. METHODS AND RESULTS: Eighteen asymptomatic hypercholesterolemic patients with documented aortic and/or carotid atherosclerotic plaques were selected for the study. A total of 35 aortic and 25 carotid artery plaques were detected. Serial black-blood MRI of the aorta and carotid artery of the patients was performed at baseline and 6 and 12 months after lipid-lowering therapy with simvastatin. The effects of the treatment on atherosclerotic lesions were measured as changes in lumen area, vessel wall thickness, and vessel wall area, a surrogate of atherosclerotic burden. Simvastatin induced a significant (P<0.01) reduction in total and LDL cholesterol levels at 6 weeks that was maintained thereafter. At 6 months, no changes in lumen area, vessel wall thickness, or vessel wall area were observed. However, at 12 months, significant reductions in vessel wall thickness and vessel wall area, without changes in lumen area, were observed in both aortic and carotid arteries (P<0.001). CONCLUSIONS: This in vivo human study demonstrates that effective and maintained lipid-lowering therapy by simvastatin is associated with a significant regression of atherosclerotic lesions. Our observation suggests that statins induce vascular remodeling, as manifested by reduced atherosclerotic burden without changes in the lumen.
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AIMS: The clinical importance of pre-operative and follow-up echocardiographic studies in patients operated on for chronic severe aortic valve regurgitation is still a matter of debate. The prognostic significance of M-mode echocardiography has never been directly compared with clinical and angiographic data. METHODS AND RESULTS: Univariate and multivariate analyses of cumulative survival were performed for clinical, echocardiographic and angiographic data of 125 patients operated on between 1975 and 1983, and followed for 13.3+/-6.4 years. Ten and 20 year survival rates were 77% and 48%, respectively. Age, NYHA class, angiographic volumes, ejection fraction, as well as M-mode echocardiographic end-systolic dimension and shortening fraction were the main pre-operative prognostic parameters for long-term survival. In a multivariate analysis the angiographic end-systolic volume index, age and preoperative NYHA class were independent pre-operative prognostic variables of long-term survival. A postoperative reduction in end-diastolic dimension of >20% predicted a significantly better late survival (74% vs 44% after 20 years, P<0.001). CONCLUSIONS: Age, pre-operative NYHA class and left ventricular systolic function are the main determinants of long-term survival after valve replacement for chronic aortic regurgitation. Despite a slightly lower predictive value of echocardiography when compared to angiography, it appeared sufficient for everyday clinical decision making for valve replacement. Echocardiography within 6 months postoperatively is able to detect recovery of left ventricular function, and enables additional risk-stratification, regardless of pre-operative findings.
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High levels of plasma lipids have been recognized as a major risk factor in the development and progression of atherosclerosis, and to influence hemorheological factors that may predispose to thrombotic complications. Lipid-lowering interventions have been associated with a significant reduction of morbidity and mortality. Several mechanisms have been postulated for the observed clinical effect. Serum lipid-regulating therapies may reduce cardiovascular risk not only by altering the arterial wall, improving disturbed endothelial function, atherogenesis and plaque stability, but also through their antithrombogenic effects and influence on blood flow properties associated with hyperlipidemia. In this article, we will review the recent literature and discuss the value of hemorheological-hemostatic findings as surrogate endpoints for clinical trials in dyslipidemic patients.
Atherosclerosis and its thrombotic complications are the major cause of morbidity and mortality in industrialized countries. Despite advances in our understanding of the pathogenetic mechanisms and new treatment modalities, the absence of an adequate noninvasive method for early detection limits the prevention or treatment of patients with various degrees and localizations of atherothrombotic disease. High-resolution magnetic resonance (MR) has recently emerged as one of the most promising techniques for the noninvasive study of atherothrombotic disease. Most importantly, MR can be used to characterize plaque composition and monitor progression. Thus, MR opens new strategies, ranging from the screening of high-risk patients for early detection and treatment as well as the monitoring of target areas for pharmacological intervention.
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OBJECTIVES: We sought to investigate baroreceptor regulation of sympathetic nerve activity and hemodynamics after inhibition of nitric oxide (NO) synthesis. BACKGROUND: Both the sympathetic nervous system and endothelium-derived substances play essential roles in cardiovascular homeostasis and diseases. Little is known about their interactions. METHODS: In healthy volunteers, we recorded muscle sympathetic nerve activity (MSA) with microneurography and central hemodynamics measured at different levels of central venous pressure induced by lower body negative pressure. RESULTS: After administration of the NO synthase inhibitor NG-monomethyl-L-arginine (L-NMMA, 1 mg/kg/min), systolic blood pressure increased by 24 mm Hg (p = 0.01) and diastolic blood pressure by 12 mm Hg (p = 0.009), while stroke volume index (measured by thermodilution) fell from 53 to 38 mL/min/m2 (p < 0.002). Administration of L-NMMA prevented the compensatory increase of heart rate, but not MSA, to orthostatic stress. The altered response of heart rate was not due to higher blood pressure, because heart rate responses were not altered during infusion of the alpha-1-adrenoceptor agonist phenylephrine (titrated to an equal increase of systolic blood pressure). In the presence of equal systolic blood pressure and central venous pressure, we found no difference in MSA during phenylephrine and L-NMMA infusion. CONCLUSIONS: This study demonstrates a highly specific alteration of baroreceptor regulation of heart rate but not muscle sympathetic activity after inhibition of NO synthesis in healthy volunteers. This suggests an important role of NO in reflex-mediated heart rate regulation in humans.