Flavin extraction method realized an improved power factor by easy removal of the dispersant from semiconducting SWNT sheet.
he combination of angiotensin II receptor blockers (ARBs) and angiotensin-converting enzyme inhibitors (ACEIs) has been reported to offer more complete blockade of the effect of angiotensin II than treatment with ACEI alone, while retaining the benefits of bradykinin potentiation obtained from ACEI treatment. 1,2 In the clinical setting, the combination of ACEI and ARB is more beneficial in preventing left ventricular remodeling and decreasing the plasma concentrations of aldosterone and brain natriuretic peptide (BNP) than either ACEI or ARB alone. 3,4 In addition, the combination therapy has recently been proved to improve prognosis to a greater extent than the monotherapy. 4,5 However, the doses of ACEI and ARB in large-scale trials performed in the USA and Europe have been 3-4-fold higher than the standard doses prescribed in Japan. The aim of this study was to Circulation Journal Vol.68, April 2004 investigate the effects of the combination of ACEI and ARB at the standard doses prescribed in Japan on left ventricular remodeling and neurohumoral factors in patients with chronic heart failure. Methods Study DesignThis is a multicenter, randomized, open-labeled trial to compare the clinical effects of ACEI or ARB monotherapy and their combination for 6 months. All the patients treated in the 26 institutes gave their written informed consent to participate in the trial, which was approved by the institutional review board of the National Cardiovascular Center, Osaka, Japan. EligibilityMen and women, 18 years old or older, with stable chronic heart failure for at least 3 months before the screening were eligible to participate in this study. In addition, they had to have documented left ventricular (LV) systolic dysfunction with an LV ejection fraction (EF) equal to or less than 45%, determined by echocardiography or LV venCirc J 2004; 68: 361 -366 (Received November 13, 2003; revised manuscript received January 20, 2004; accepted January 27, 2004) The institutes particpating in the study are listed in Appendix 1. Background The present multicenter study investigated whether the combination of angiotensin-converting enzyme inhibitor (ACEI) and angiotensin II receptor blocker (ARB) is more beneficial for preventing left ventricular remodeling and suppressing neurohumoral factors than either ACEI or ARB alone. Methods and ResultsOne hundred and six patients with mild-to-moderate congestive heart failure treated in 26 Japanese institutes were randomly assigned to the combination therapy or monotherapy. Changes in physical activity (New York Heart Association functional classes, Specific Activity Scale (SAS)), concentrations of neurohumoral factors (plasma renin activity, angiotensin II, aldosterone, and brain natriuretic peptide (BNP)), and cardiac function for 6 months were compared between the 2 groups. It was found that the combination therapy, which was administered at doses standard in Japan, increased the SAS score (4.5±1.5 to 4.9±1.5, p<0.05) and decreased the plasma BNP concentration (183±163 to 135±1...
We have directly demonstrated that the mesenteric veins actively constrict and dilate in response to reflex stimuli in the in situ preparation. A segment of small intestine of 23 chloralose-anesthetized rabbits was exposed in a specially designed bath. Small vein diameter and intravenous pressure (575-1,375 microns and 6.2-11.4 mmHg at rest, respectively) of the mesentery were measured continuously at the same site with the use of videomicrometer and micropressure systems during celiac ganglion stimulation (CGS), bilateral carotid occlusion (BCO), and aortic nerve stimulation (ANS). Innervation to the mesenteric vein was evident by a frequency-dependent venoconstriction in response to CGS, which was completely abolished by local application of tetrodotoxin. Vein diameter and intravenous pressure changed from an average of 1,042 +/- 32 to 1,003 +/- 32 microns (-3.8 +/- 0.3%, P less than 0.01) and from 8.1 +/- 0.3 to 9.0 +/- 0.3 mmHg (10.6 +/- 0.8%, P less than 0.01), respectively, during BCO. During ANS, vein diameter increased from 990 +/- 32 to 1,012 +/- 31 microns (2.4 +/- 0.2%, P less than 0.01), and intravenous pressure decreased from 8.5 +/- 0.3 to 7.9 +/- 0.2 mmHg (-6.1 +/- 0.6%, P less than 0.01), respectively. Vein diameter changes of -3.8 and 2.4% corresponded to volume changes of -7.6 and 4.9%, respectively. During BCO, vein diameter decreased while intravenous pressure increased, whereas during ANS vein diameter increased while intravenous pressure decreased. These results indicate that the reflex change in vein diameter is due to an active response.
Although venous capacitance has been studied in the neurally isolated tissue or in the in vitro vein segment, this is the first study of sympathetic regulation of the pressure-diameter relation in mesenteric veins in situ, where innervation is kept intact. In 25 a!-chloralose-anesthetized rabbits, mesenteric vein diameter (679±27 gm, ranges of 380-1,050 ,tm at initial state) and intravenous pressure were measured continuously at the same site by using videomicrometer and micropressure systems. Intravenous pressure was increased in a stepwise fashion from the baseline of 6-9 mm Hg to -10, -13, -16, -19, and occasionally to -22 or -26 mm Hg by occluding the portal vein with a pneumatic occluder. Each intravenous pressure was maintained for 90-120 seconds or 4-5 minutes until the diameter increase reached a plateau. Pressure-diameter curves were generated for the control state, during celiac ganglion stimulation, and during local tetrodotoxin or intravenous hexamethonium administration. Diameter was plotted as a function of pressure, and the curves were nonlinear or sigmoid. These results are different from the linear or curvilinear characteristics of the pressure-diameter or pressure-volume relation observed in the pharmacologically or chemically denervated preparation. Tetrodotoxin and hexamethonium attenuated the sigmoid shape of the pressurediameter curve and shifted it toward the diameter axis of the curve. On the other hand, celiac ganglion stimulation did not change the sigmoid nature of the curve but shifted the curve toward the volume axis. Relative areas between celiac ganglion stimulation and control curves, tetrodotoxin and control curves, hexamethonium and control curves, and the two control curves were -92.6±+18.8 (p<0.01), 80.6±22.0 (p<0.05), 92.4±37.3 (p<0.01), and 6.5±4.9, respectively. These results demonstrate that the pressure-diameter relation is significantly controlled by sympathetic tone to these veins. (Circulation Research 1991;68:888-896) R eflex control of venous capacitance plays an important role in regulation of cardiac output by affecting the filling of the right heart.1-3 Splanchnic circulation accounts for approximately 25% of the total blood volume and can be regulated by various reflex mechanisms.4-8 The capacitance of the splanchnic circulation depends on both the compliance of the system (slope of the pressure-volume curve) and the unstressed vascular volume (volume-axis intercept of the pressure-volume curve). The purpose of this study was to demonstrate the P-D relation of small mesenteric veins and evaluate the effect of sympathetic tone in the preparation where sympathetic innervation was kept intact. We used a simultaneous recording system for the mesenteric vein diameter and intravenous pressure at the same site in the in situ preparation and found
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