8 research outputs found
Traditional acupuncture does not modulate the endothelial dysfunction induced by mental stress
No full textAcupuncture is a useful tool to treat many diseases, including cardiovascular disorders, but its modulation of stress-related responses is still debated. Aim of this study was to estimate whether the traditional Chinese acupuncture affected the transient impairment of the brachial artery flow-mediated dilation (FMD) produced by acute mental stress. In addition, since a high susceptibility to hypnosis attenuates the endothelial dysfunction elicited by mental calculation, the possible interaction between acupuncture and hypnotizability was investigated. Five low-to-medium and five medium-to-high hypnotizable healthy subjects joined two experimental sessions, for real and sham acupuncture. FMD and heart rate were measured in three conditions: baseline (PRE), after the real or sham acupuncture (ACU) and after mental calculation (MS). Needles were inserted into specific acupoints for real acupuncture and into non-acupoints, corresponding to the same spinal segment, for sham acupuncture. Results showed that the stress-related endothelial dysfunction was not modulated by acupuncture, but influenced by hypnotizability. In fact, highly hypnotizable subjects did not present any dysfunction, at variance with non-susceptible individuals that exhibited the expected stress-related FMD reduction (Mean +/- SD; PRE, 12.10 +/- 2.59; ACU, 10.73 +/- 3.45; MS, 6.48 +/- 1.72). Thus, hypnotizability appears more effective than acupuncture in contrasting the stress effects on the endothelial function. In conclusion, our study indicates the importance of patients' psychological evaluation in order to choose proper relaxation techniques and to evaluate therapeutic results and the necessity to integrate the alternative medicine practice with scientific research
Enoximone echocardiography for predicting recovery of left ventricular-dysfunction after revascularization: a novel test for detecting myocardial viability
No full textDottorato di ricerca in fisiopatologia cardiovascolare. 11. ciclo. A.a. 1998-99. Coorelatore Alessandro Distante. Relatore Alberto ZanchettiConsiglio Nazionale delle Ricerche - Biblioteca Centrale - P.le Aldo Moro, 7, Rome; Biblioteca Nazionale Centrale - P.za Cavalleggeri, 1, Florence / CNR - Consiglio Nazionale delle RichercheSIGLEITItal
Comparison of stress/rest myocardial perfusion tomography, dipyridamole and dobutamine stress echocardiography for the detection of coronary disease in hypertensive patients with chest pain and positive exercise test
No full textAbstractOBJECTIVESAlthough different noninvasive tests have been proposed for detecting coronary artery disease (CAD) in patients with hypertension and chest pain symptoms, the relative performance of the available techniques has not been systematically assessed.BACKGROUNDPatients with hypertension frequently complain of chest pain and exhibit ischemic-like ST segment changes on the exercise electrocardiogram (ECG). However, the specificity of such changes for predicting significant CAD is very low, because these patients often exhibit a normal coronary angiogram.METHODSIn 101 patients with hypertension, chest pain and positive exercise ECG, we performed stress/rest myocardial single photon emission computed tomography with 99mTc-MIBI, dipyridamole and dobutamine stress echocardiography and coronary angiography. All patients had normal global ventricular function and 57 had left ventricular hypertrophy. All were kept on ACE inhibitors during the study period.RESULTSNo patients had significant side effects during perfusion scintigraphy. Dose-limiting side effects were observed in five patients with dipyridamole and in seven patients with dobutamine. Only 56% of study patients exhibited significant CAD. Sensitivity, specificity, accuracy, positive and negative predictive values were, respectively, 98%, 36%, 71%, 67% and 94% for perfusion scintigraphy, 61%, 91%, 74%, 90% and 64% for dipyridamole and 88%, 80%, 84%, 85% and 83% for dobutamine stress echocardiography.CONCLUSIONSThis study shows that stress echo in patients with hypertension yields a satisfactory diagnostic accuracy for identifying significant epicardial CAD. Our results indicate that dobutamine might be superior to dipyridamole. The low specificity of myocardial scintigraphy probably relates to the fact that this method traces perfusion abnormalities, not necessarily caused by epicardial CAD, possibly due to microvascular disease and not causing obvious wall motion abnormalities
The U‐Pb Geochronology and Lu‐Hf Isotope Compositions of Detrital Zircons from the Nanhua Group of the Longsheng Region, South China and their Implications for Pan‐African Events
No full textInfluence of Variable Loading Conditions on Pulsed Doppler Indices of Left Ventricular Ejection Dynamics
No full textAcute effects of heparin administration on the ischemic threshold of patients with coronary artery disease Evaluation of the protective role of the metabolic modulator trimetazidine
No full textAbstractObjectivesWe sought to assess the effects of heparin and the potential protective effects of trimetazidine (TMZ) on exercise performance, plasma nitric oxide (NO), endothelin-1 (ET-1) and free fatty acid (FFA) release in patients with stable coronary artery disease (CAD).BackgroundHeparin has been shown to reduce the ischemic threshold in patients with CAD. Trimetazidine may affect myocardial substrate utilization by shifting energy production from FFA to glucose oxidation.MethodsIn four consecutive days, nine patients with CAD each received one of the following four regimens: 1) one tablet of placebo the evening before and at 8 amand 4 pmon the day of the study, 10 ml of saline in a bolus 10 min before exercise, followed by an infusion of the same preparation; 2) placebo at the same times as in the first regimen, 5,000 IU of heparin 10 min before exercise, followed by 1,000 IU/h; 3) 20 mg TMZ at the same times as in the first regimen, 5,000 IU of heparin 10 min before exercise, followed by 1,000 IU/h; or 4) TMZ at the same times as in the first regimen, 10 ml of saline 10 min before exercise, followed by an infusion of the same preparation.ResultsDuring placebo (test 2), heparin reduced the time to 1-mm ST-segment depression and prolonged the recovery time, as compared with the results of test 1. When heparin was administered after TMZ (test 3), the time to 1-mm ST-segment depression and the recovery time were similar to those recorded during saline (test 1). Finally, compared with all study phases, TMZ during saline (test 4) prolonged the time to 1 mm. No changes in NO release were found, whereas ET-1 was decreased at peak exercise and during recovery, when the patients were receiving TMZ (tests 3 and 4). Free fatty acids increased after heparin, both with placebo and TMZ.ConclusionsIn patients with CAD, heparin reduces the ischemic threshold. Trimetazidine reduces the effects of heparin, probably by inhibiting FFA oxidation and enhancing glucose metabolism. The concomitant novel observation of reduced ET-1 release is likely to be also dependent on TMZ-induced improvement of endothelial metabolism or reduction of myocardial ischemia
Modifying organic/metal interface via solvent treatment to improve electron injection in organic light emitting diodes
No full textBy simply spin-coating the solvents, such as ethanol and methanol, on top of the organic active layer, the performance of polymer organic light-emitting diodes is significantly enhanced. The quantum efficiency is increased by as large as 58% for low work function Ba/Al cathode devices after solvent treatment. An interface dipole between the organic layer and the metal layer induced by the solvent, either from the intrinsic dipole or the interaction between the solvent and the cathode metal, is responsible for the device performance improvement. The interface dipole layer, which is confirmed by the Kelvin Probe Force Microscopy and the photovoltaic measurements, lifts the vacuum level on the metal side, thereby reducing the electron injection barrier at the organic/metal interface, and leading to better device performance. (C) 2011 Elsevier B.V. All rights reserved.Materials Science, MultidisciplinaryPhysics, AppliedSCI(E)EI34ARTICLE111858-18631
Southern China can produce more high-quality rice with less N by green manuring
No full textGreen manures (GMs) are commonly used in reducing synthetic fertilizer input and mitigating environmental burden in paddy fields in China, but the contributions and comprehensive mechanisms of GMs are not illustratedclearly. We have established an experiment network of GM–rice rotation and have demonstrated extensively across eight provinces in southern China since 2008. Results from 201 site–year field experiments and the survey of GM’s responses at 71 demonstration sites and 2062 farmers were collected. Compared with conventional synthetic N (CN) fertilization without GM, GM with 60% CN achieved the same level of rice yield, total amino acid concentration increased by 62.64% in the grains, and CN use efficiency increased by 15.8%, whereas the Cfootprint, reactive N loss, and N footprint decreased by 30.81%, 19.18%, and 9.65%, respectively. This quantitative analysis of green manuring provides support to rice production with low N input in southern China
