The basal release of vasoactive intestinal polypeptide (VIP) from freshly prepared enriched synaptosomes was 159.1 +/- 17.3 fmol/mg protein (100%), which constituted 2.5% of the total VIP content. Basal VIP release was reduced by 65% by removal of external Ca2+. Release of VIP was stimulated by depolarization with KCl (65 mM, 143%) and in the presence of veratridine (10(-6) M, 184%), monensin (10(-5) M, 131%), and the Ca2+ ionophore A-23187 (10(-6) M, 160%). Stimulation of adenosine 3',5'-cyclic monophosphate (cAMP)-dependent mechanisms using isoproterenol (10(-6)-10(-4) M) and forskolin (10(-6) and 10(-5) M) had no stimulatory influence on VIP release. In contrast, sodium nitroprusside (10(-4) M, 198%), the nitric oxide (NO) donor 3-(morpholino)sydnonimine (10(-4) M, 155%), and the guanosine 3',5'-cyclic monophosphate (cGMP) analogue 8-bromo cGMP (10(-4) M, 196%) caused a significant release of VIP. L-Arginine (10(-3) M, 246%) also caused a significant increase of VIP release that was antagonized by the NO synthase inhibitor N omega-nitro-L-arginine methyl ester (5 x 10(-4) M, 131%), which had no effect when given alone. The results demonstrate that VIP can be released from enriched synaptosomes by Ca(2+)-dependent mechanisms by NO agonists or NO-dependent mechanisms. It is speculated that this VIP release is induced by a presynaptic stimulatory mechanism of NO and this effect could enhance or contribute to the action of NO.
Encouraging results of ablation therapy in patients with paroxysmal atrial fibrillation (AF) have prompted changes in professional practice guidelines. The most recent European guidelines have suggested that ablation might be offered as first-line therapy in selected patients. Cryoballoon ablation is a promising technology in interventional AF therapy. Two different sizes of the cryoballoon are currently available: a smaller (23 mm) and a larger (28 mm) balloon relative to the ostial diameter of the pulmonary veins. New tools, the circular mapping catheter and the use of intracardiac echocardiography, provide important periprocedural information. A meta-analysis of previous studies revealed outcome data with an AF-free survival rate of 72.83% at the 1-year follow-up in paroxysmal AF patients undergoing cryoballoon ablation. The most frequent, but reversible complication is phrenic nerve palsy with reported incidences up to 10%. All efforts must be taken to overcome this limitation, since the overall major complication rate tends to be lower in cryoballoon compared to radiofrequency ablation. In persistent AF, reported results in cryoballoon ablation had a limited success rate below 50% after a single procedure. A double balloon approach using both cryoballoon sizes might overcome some of the limitations in persistent AF. Prospective data and randomized studies are required. This article outlines the current status of cryoballoon technology in AF ablation therapy.
Background: Long-term morbidity and mortality outcomes of the arterial switch operation (ASO) in patients with transposition of the great arteries and Taussig-Bing anomaly are excellent. With an increasing number of patients reaching adolescence and adulthood, more attention is directed toward quality of life. Our study aimed to determine the health-related quality of life (hrQoL) outcomes in patients after the ASO and identify factors influencing their hrQoL. Methods: In this cross-sectional study, hrQoL of patients after ASO was assessed with the German version of the Short Form-36 (SF-36) and the potential association of specified clinical factors was analyzed. Patients of at least 14 years of age who underwent ASO in our institution from 1983 were considered eligible. Results: Of the 355 questionnaires sent to eligible patients, 261 (73%) were available for analysis. Compared to the reference population, patients who had undergone ASO had a significantly higher score in all subscales of the SF-36 except for vitality ( P < .01). Patients with an implanted pacemaker ( P = .002), patients who required at least one reoperation ( P < .001), and patients currently taking cardiac medication ( P < .004) or oral anticoagulation ( P = .036) had lower physical component scores compared to patients without these factors. Conclusions: Patients’ self-assessed and self-reported hrQoL after ASO (using German version of the Short Form 36) is very good. In this population, hrQoL is influenced by reoperation, the need for a pacemaker, and current cardiac medication or anticoagulant use. The development of strategies designed to mitigate or minimize the requirements for, and/or impact of these factors may lead to better hrQoL in this patient population.
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