Arterial hypertension is a significant cause of end-stage renal failure; effective treatment of hypertensive patients reduces the rate of progression of this disorder. ss-Blockers, particularly ...nonselective agents, are associated with deterioration of renal function in patients with chronic renal failure. Previous studies on the interaction of the beta1-selective adrenergic antagonist bisoprolol with kidney function have been performed only acutely and over the short term. This study was designed to evaluate the antihypertensive efficacy and effects on renal hemodynamics and function of bisoprolol during medium-term (6 mo) treatment of patients with mild to moderate essential hypertension. After a 2-wk run-in period on placebo, 87 consecutive hypertensive patients (46 men, 41 women) according to ESH-ESC (European Society of Hypertension/European Society of Cardiology) guidelines, aged from 27 to 64 y (mean age, 50+/-11 y), without renal or cardiovascular disease, were enrolled and assigned to treatment with bisoprolol 5 mg once daily for 6 mo. At recruitment and at 6 mo after treatment, renal function was assessed and renal hemodynamics evaluated in all patients through radioisotope studies. The medium-term effects of bisoprolol included a significant reduction in blood pressure and heart rate (P<.001) without significant adverse drug reactions. Moreover, bisoprolol produced no alteration in renal function or hemodynamics, or in cardiac output. Data presented here indicate that bisoprolol 5 mg given once daily to treat patients with mild to moderate essential hypertension is effective and safe for treatment and for preservation of renal performance when given on a medium-term basis.
The phase behaviour of thermoplastic interpenetrating polymer networks based on semi-crystalline polyurethane and a styrene/acrylic acid block-copolymer has been investigated by differential scanning ...calorimetry and dynamic mechanical spectroscopy. Distinct calorimetric and mechanical transitions point to an inherent heterogeneity characterizing the structure of thermoplastic networks, mainly due to a weak affinity of the two components. At variance with these observations, deviations from a simple additive law are revealed from the composition behaviour of the melting endotherms associated to polyurethane component and of the γ- and α
a
-relaxation strengths. Quantitative analysis of low temperature γ-relaxation indicates that the fraction of amorphous chains of polyurethane is enhanced on blending, this result being in close agreement with calorimetric results. The findings suggest the formation of a mixed amorphous microphase as a consequence of specific weak interactions (H bonds) between the functional groups of the two components.
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