Atenolol versus losartan in children and young adults with Marfan's syndrome

BACKGROUND : Aortic-root dissection is the leading cause of death in Marfan's syndrome. Studies suggest that with regard to slowing aortic-root enlargement, losartan may be more effective than beta-blockers, the current standard therapy in most centers. METHODS : We conducted a randomized trial comparing losartan with atenolol in children and young adults with Marfan's syndrome. The primary outcome was the rate of aortic-root enlargement, expressed as the change in the maximum aortic-root-diameter z score indexed to body-surface area (hereafter, aortic-root z score) over a 3-year period. Secondary outcomes included the rate of change in the absolute diameter of the aortic root; the rate of change in aortic regurgitation; the time to aortic dissection, aortic-root surgery, or death; somatic growth; and the incidence of adverse events. RESULTS : From January 2007 through February 2011, a total of 21 clinical centers enrolled 608 participants, 6 months to 25 years of age (mean [+/- SD] age, 11.5 +/- 6.5 years in the atenolol group and 11.0 +/- 6.2 years in the losartan group), who had an aorticroot z score greater than 3.0. The baseline-adjusted rate of change (+/- SE) in the aortic-root z score did not differ significantly between the atenolol group and the losartan group (-0.139 +/- 0.013 and -0.107 +/- 0.013 standard-deviation units per year, respectively; P = 0.08). Both slopes were significantly less than zero, indicating a decrease in the degree of aortic-root dilatation relative to body-surface area with either treatment. The 3-year rates of aortic-root surgery, aortic dissection, death, and a composite of these events did not differ significantly between the two treatment groups. CONCLUSIONS : Among children and young adults with Marfan's syndrome who were randomly assigned to losartan or atenolol, we found no significant difference in the rate of aorticroot dilatation between the two treatment groups over a 3-year period

X-wave mediated instability of plane waves in Kerr media

Plane waves in Kerr media spontaneously generate paraxial X-waves (i.e. non-dispersive and non-diffractive pulsed beams) that get amplified along propagation. This effect can be considered a form of conical emission (i.e. spatio-temporal modulational instability), and can be used as a key for the interpretation of the out of axis energy emission in the splitting process of focused pulses in normally dispersive materials. A new class of spatio-temporal localized wave patterns is identified. X-waves instability, and nonlinear X-waves, are also expected in periodical Bose condensed gases.Comment: 4 pages, 6 figure

Pressor Effects on Blood Pressure Induced by Isovolumic Bladder Distension and Electro-Acupuncture Stimulations in Anesthetized Rats

The pressor effects on blood pressure (BP) elicited by electro-acupuncture (Ea) stimulations and vesico-vascular reflex (VVR) were investigated in anesthetized rats. Twenty adult female Sprague-Dawley rats were used throughout this study. Two acupoints, the Hoku (Li-4) and the Tsusanli (St-36), were tested by a low frequency Ea (LFEa, 2 Hz) and a high frequency Ea (HFEa, 20 Hz) with intensities 20 times that of the motor threshold. Ea at Tsusanli elicited no pressor effects (98.15 +/- 4.10% and 101.43 +/- 3.96% of pre-stimulation control in LFEa and HFEa, respectively) whereas pressor effects could be induced by Ea stimulations at Hoku (126.3 +/- 3.3% and 136.3 +/- 3.8% of pre-stimulation control in LFEa and HFEa, respectively. P < 0.01, n = 10). In addition, the patterns of pressor effects elicited by LFEa and HFEa at Hoku were different, i.e., LFEa at Hoku elicited a tonic pressor effect, while HFEa elicited a phasic one. The VVR induced by bladder isovolumic saline distension also elicited a pressor effect on BP (119.2 +/- 2.2%, P < 0.01, n = 10) in the same preparations during bladder contractions. The VVR did not modify the Ea-induced pressor responses, and vice versa, when both of them were superimposed. All the results suggested that the pressor effects elicited by the VVR and the Ea stimulation were additive responses. In addition, for future clinical application, our findings may imply that patients should be carefully monitored for signs and symptoms of autonomic dysfunction during clinical acupuncture treatments

Dietary n-3 and n-6 Fatty Acids Alter Avian Pituitary Sensitivity

The effects of dietary saturated and polyunsaturated fatty acids (PUFAs) of the n-3 and n-6 series on avian pituitary sensitivity were investigated by infusing human growth hormone (GH) releasing hormone - fragment 1-29 - and chicken luteinising hormone releasing hormone (LHRH) into catheterized broiler chickens. At 3 weeks of age three groups (n=18; six birds per group) were fed for 6 weeks isonitrogenous and isoenergetic experimental diets containing 80 g/kg of edible tallow (saturated fatty acids), fish oil (n-3 PUFAs) or sunflower oil (n-6 PUFAs). Jugular catheterisation was performed under general anaesthesia during week four of the dietary treatments and the birds allowed 7 days post surgery to recover. A bolus of LHRH (20 b.mug/bird) and a GH releasing hormone (12.5 b.mug/kg) infusion was given on different days to each chicken and serial blood samples taken over a 1 h period. Plasma luteinising hormone and GH concentrations were measured by radioimmunoassay. Pre-infusion GH concentrations were similar for the tallow, fish and sunflower oil dietary groups (5.2±3.9, 5.2±1.0 and 6.1±3.1 ng/ml, respectively), however, GH concentration in response to the GH releasing hormone infusion was elevated in the sunflower oil group (44.7±5.7 ng/ml) when compared to chicken fed tallow (33.7±9.7 ng/ml) or fish oil (21.3±5.0 ng/ml). There was a significant decrease (