28 research outputs found

    Reduction of myocardial infarction by postischemic administration of the calpain inhibitor A-705253 in comparison to the Na(+)/H(+) exchange inhibitor Cariporide (R) in isolated perfused rabbit hearts

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    The calpain inhibitor A-705253 and the Na(+)/H(+) exchange inhibitor Cariporide (R) were studied in isolated perfused rabbit hearts subjected to 60 min occlusion of the ramus interventricularis of the left coronary artery (below the origin of the first diagonal branch), followed by 120 min of reperfusion. The inhibitors were added to the perfusion fluid solely or in combination at the beginning of reperfusion. Hemodynamic monitoring and biochemical analysis of perfusion fluid from the coronary outflow were performed. Myocardial infarct size and area at risk (transiently not perfused myocardium) were determined from left ventricular slices after a special staining procedure with Evans blue and 2,3,5-triphenyltetrazolium chloride. The infarcted area (dead myocardium) was 72.7 +/- 4.0% of the area at risk in untreated controls, but was significantly smaller in the presence of the inhibitors. The largest effect was observed with 10(-6) M A-705253, which reduced the infarcted area to 49.2 +/- 4.1% of the area at risk, corresponding to a reduction of 33.6%. Cariporide (R) at 10(-6) M reduced the infarct size to the same extent. The combination of both inhibitors, however, did not further improve cardioprotection. No significant difference was observed between the experimental groups in coronary perfusion, left ventricular pressure, heart rate, or in the release of lactate dehydrogenase and creatine kinase from heart muscle

    Precipitate Redistribution During Creep of Alloy 617

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    Nickel-based superalloys are being considered for applications within advanced nuclear power generation systems due to their high temperature strength and corrosion resistance. Alloy 617, a candidate for use in heat exchangers, derives its strength from both solid solution strengthening and the precipitation of carbide particles. However, during creep, carbides that are supposed to retard grain boundary motion are found to dissolve and re-precipitate on boundaries in tension. To quantify the redistribution, we have used electron backscatter diffraction and energy dispersive spectroscopy to analyze the microstructure of 617 after creep testing at 900 and 1000°C. The data were analyzed with respect to location of the carbides (e.g., intergranular vs. intragranular), grain boundary character, and precipitate type (i.e., Cr-rich or Mo-rich). We find that grain boundary character is the most important factor in carbide distribution; some evidence of preferential distribution to boundaries in tension is also observed at higher applied stresses. Finally, the results suggest that the observed redistribution is due to the migration of carbides to the boundaries and not the migration of boundaries to the precipitates

    Risk profiles and one-year outcomes of patients with newly diagnosed atrial fibrillation in India: Insights from the GARFIELD-AF Registry.

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    BACKGROUND: The Global Anticoagulant Registry in the FIELD-Atrial Fibrillation (GARFIELD-AF) is an ongoing prospective noninterventional registry, which is providing important information on the baseline characteristics, treatment patterns, and 1-year outcomes in patients with newly diagnosed non-valvular atrial fibrillation (NVAF). This report describes data from Indian patients recruited in this registry. METHODS AND RESULTS: A total of 52,014 patients with newly diagnosed AF were enrolled globally; of these, 1388 patients were recruited from 26 sites within India (2012-2016). In India, the mean age was 65.8 years at diagnosis of NVAF. Hypertension was the most prevalent risk factor for AF, present in 68.5% of patients from India and in 76.3% of patients globally (P < 0.001). Diabetes and coronary artery disease (CAD) were prevalent in 36.2% and 28.1% of patients as compared with global prevalence of 22.2% and 21.6%, respectively (P < 0.001 for both). Antiplatelet therapy was the most common antithrombotic treatment in India. With increasing stroke risk, however, patients were more likely to receive oral anticoagulant therapy [mainly vitamin K antagonist (VKA)], but average international normalized ratio (INR) was lower among Indian patients [median INR value 1.6 (interquartile range {IQR}: 1.3-2.3) versus 2.3 (IQR 1.8-2.8) (P < 0.001)]. Compared with other countries, patients from India had markedly higher rates of all-cause mortality [7.68 per 100 person-years (95% confidence interval 6.32-9.35) vs 4.34 (4.16-4.53), P < 0.0001], while rates of stroke/systemic embolism and major bleeding were lower after 1 year of follow-up. CONCLUSION: Compared to previously published registries from India, the GARFIELD-AF registry describes clinical profiles and outcomes in Indian patients with AF of a different etiology. The registry data show that compared to the rest of the world, Indian AF patients are younger in age and have more diabetes and CAD. Patients with a higher stroke risk are more likely to receive anticoagulation therapy with VKA but are underdosed compared with the global average in the GARFIELD-AF. CLINICAL TRIAL REGISTRATION-URL: http://www.clinicaltrials.gov. Unique identifier: NCT01090362

    Effect of moderate alcohol consumption on adiponectin, tumor necrosis factor-alpha, and insulin sensitivity

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    OBJECTIVE - Epidemiological studies suggest that moderate alcohol consumers have enhanced insulin sensitivity and a reduced risk of type 2 diabetes. Adiponectin, an adipocyte-derived plasma protein, has been found to be negatively associated with adiposity and positively associated with insulin sensitivity. Moderate alcohol consumption may increase adiponectin, which in turn causes a decrease of tumor necrosis factor (TNF)-α. A decreased TNF-α level may consequently increase insulin sensitivity. RESEARCH DESIGN AND METHODS - To test this hypothesis, we performed a randomized crossover partially diet-controlled study. A total of 23 healthy middle-aged male subjects consumed daily four glasses of whisky (40 g ethanol) or tap water with dinner during two successive periods of 17 days. RESULTS - Moderate alcohol consumption increased plasma adiponectin level (11%; P = 0.002) but did not affect plasma TNF-α level. An increase in insulin sensitivity index was observed in an insulin-resistant subgroup (21%; P = 0.11), which positively correlated with the relative alcohol-induced increase in plasma adiponectin level (r = 0.73, P = 0.02). CONCLUSIONS - The experimental results are in agreement with observational data. Moderate alcohol consumption improved insulin sensitivity in relatively insulin-resistant middle-aged men, an effect that may be mediated through alcohol-induced increases in adiponectin

    Obligatory role of hyperaemia and shear stress in microvascular adaptation to repeated heating in humans

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    The endothelium, a single layer of cells lining the entire circulatory system, plays a key role in maintaining vascular health. Endothelial dysfunction independently predicts cardiovascular events and improvement in endothelial function is associated with decreased vascular risk. Previous studies have suggested that exercise training improves endothelial function in macrovessels, a benefit mediated via repeated episodic increases in shear stress. However, less is known of the effects of shear stress modulation in microvessels. In the present study we examined the hypothesis that repeated skin heating improves cutaneous microvascular vasodilator function via a shear stress-dependent mechanism. We recruited 10 recreationally active males who underwent bilateral forearm immersion in warm water (42°C), 3 times per week for 30 min. During these immersion sessions, shear stress was manipulated in one arm by inflating a pneumatic cuff to 100 mmHg, whilst the other arm remained uncuffed. Vasodilatation to local heating, a NO-dependent response assessed using laser Doppler, improved across the 8 week intervention period in the uncuffed arm (cutaneous vascular conductance week 0 vs. week 4 at 41°C: 1.37 ± 0.45 vs. 2.0 ± 0.91 units, P= 0.04; 42°C: 2.06 ± 0.45 vs. 2.68 ± 0.83 units; P= 0.04), whereas no significant changes were evident in the cuffed arm. We conclude that increased blood flow, and the likely attendant increase in shear stress, is a key physiological stimulus for enhancing microvascular vasodilator function in humans
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