The 2,4-dinitrophenyl group for protection of hydroxyl function of tyrosine during solid-phase peptide synthesis

The facile thiolytic cleavage of the O-2,4-dinitrophenyl (Dnp) tyrosine bond was applied to the solid-phase synthesis of the 22-amino acid residue peptide H-Asp-Ala-Val-Tyr -Thr-Gly-Leu-Asn-Thr-Arg-Asn-Gln-Glu-Thr-Tyr -Glu-Thr-Leu-Lys-His-Glu-Lys-OH, corresponding to positions 62-83 in the chain of the type 1 receptor for Fc_ε, domains expressed on the rat mucosal-type mast cells (line RBL-2H3). A method for the spectrophotometric determination of insoluble O-Dnp as well as of unprotected phenolic moieties of tyrosine was developed. It is based on monitoring S-Dnp-2-mercaptoethanol, produced upon O-Dnp thiolysis by 2-mercaptoethanol. © Munksgaard 1995. Dedicated to the memory of Dr. Susumu Funakoshi, a dear friend and a leader in peptide chemistry.     

Mode of Onset of Malignant Ventricular Arrhythmias in Idiopathic Ventricular Fibrillation

Mode of Onset of Idiopathic VF. Introduction : The mode of onset of malignant ventricular arrhythmias (ventricular tachycardia [VT] or ventricular fibrillation [VF] has been well described in patients with organic heart disease and in patients with the long QT syndromes. Less is known about the mode of onset of VF in patients with out-of-hospital VF who have no evidence of organic heart disease or identifiable etiology.
Methods and Results : We reviewed the ECGs of all our patients with Idiopathic VF. Documentation of the onset of spontaneous arrhythmias was available for 22 VK episodes in 9 patients (6 men and 3 women; age 41 ± 16 years). In all instances, spontaneous VF followed a rapid polymorphic VT, which was initiated by premature ventricular complexes (PVCs) with very short coupling intervals. The PVC initiating VF had a coupling interval of 302 ± 52 msec and a prematurity index of 0.4 ± 0.07. These PVCs occurred within 40 msec of the peak of the preceding T wave. Pause-dependent arrhythmias were never observed.
Concltision : Cardiac arrest among patients with idiopathic VF has a very distinctive mode of onset. Documentation of a polymorphic VT that is not pause dependent is of diagnostic value.     

Pace-Termination and Pacing for Prevention of Atrial Tachyarrhythmias: Results from a Multicenter Study with an Implantable Device for Atrial Therapy

INTRODUCTION: Patients with bradycardia requiring permanent pacing frequently suffer from additional atrial tachyarrhythmias (ATs). This study evaluated the safety and efficacy of atrial antitachycardia pacing (ATP) and the performance of pacing for AT prevention implemented into a new pacemaker. METHODS AND RESULTS: In patients with conventional indications for permanent pacing, an investigational DDDRP pacemaker (Medtronic AT500, model 7253) was implanted. The primary study objectives were to determine the safety of overall device functioning and its efficacy in terminating spontaneous AT. A secondary endpoint was to determine the reliability of AT detection. Pacemaker memory functions were used to analyze the impact of dedicated pacing algorithms on AT prevention. In 33 European and Canadian centers, 325 patients were enrolled (mean follow-up 2.3+/-1.3 months). Complication-free survival at 3 months was 88%. In 2,145 episodes stored with atrial electrograms, AT detection was confirmed in 97%. The algorithm for continuous overdrive pacing increased the percentage of atrial pacing to 97%. After ATP activation, 16,683 of 52,468 AT episodes were treated (120 patients). Of these, 8,903 episodes (53%) were terminated successfully by ATP. No proarrhythmic effect of preventive pacing or atrial ATP was observed. Preventive pacing algorithms increased the median percentage of atrial pacing from 62% to 97%. However, the number of AT/AF (atrial fibrillation) episodes (4.1 vs 4.1 per patient per day) and the time in AT/AF (13.7% vs 12.8%) was not significantly different before and after activation of preventive pacing. CONCLUSION: DDDRP pacing with a new system for AT therapy was safe and associated with successful pace-termination of AT in 53% of episodes. Preventive pacing and atrial ATP algorithms represent two new functions that can be implemented safely into pacemaker systems for nonpharmacologic treatment of ATs in patients requiring pacemaker therapy.     

Using Disease-State Management as the Key to Promoting Employer Sponsorship of Medical Nutrition Therapy

The purpose of this project was to design, implement, and improve a nationwide medical nutrition therapy (MNT) intervention program for nutritionally at-risk employees and their dependents and retirees (hereinafter referred to as clients) with a Fortune 100 company (Texas Instruments, Dallas, Tex) with a dispersed population of 80,000. Preferred Nutrition Therapists (PNT), a network of registered dietitians, with the assistance of the Texas Instruments Health Promotion and Benefits Department, identified International Classification of Diseases, 9th ed (ICD-9), codes for which MNT intervention was appropriate. PNT then negotiated a contract with the Texas Instruments Health Promotion and Benefits Department and implemented clients’ self-referral process. The main challenge was to promote utilization of a new service from an outside vendor (PNT) and to measure outcomes in meaningful ways. The goal was to use MNT as a tool to prevent the progression of clients’ diseases to states that require more costly treatments. PNT used a continuous quality improvement process to refine the system and improve information gathering and reporting, by providing quarterly reports to the Health Promotion and Benefits Department. These reports summarized the outcomes for all clients seen at least 3 times during the quarter. The cost was less than $0.35 per member per month (less than the employer spent on advertising the program), and 0.5% of the population requested MNT during the first year of implementation (about what was expected for a new carveout benefit). J Am Diet Assoc. 1999;99:583–588.