The effect of anodal/cathodal biphasic electrical stimulation on insulin release.

We studied the effects of electrical stimulation on insulin release from rat insulinoma (INS-1) cells. The anodal/cathodal biphasic stimulation (ACBPS) electrical waveform resulted in a voltage- and stimulation duration-dependent increase in insulin release. ACBPS elicited insulin release both in the presence and absence of glucose.

Effects of biphasic and monophasic electrical stimulation on mitochondrial dynamics, cell apoptosis, and cell proliferation.

Currently, electrical stimulation (ES) is used to induce changes in various tissues and cellular processes, but its effects on mitochondrial dynamics and mechanisms are unknown. The aim of this study was to compare the effects of monophasic and biphasic, anodal, and cathodal ES on apoptosis, proliferation, and mitochondrial dynamics in neuroblastoma SH-SY5Y cells. Cells were cultured and treated with ES.

Paced monophasic and biphasic waveforms alter transmembrane potentials and metabolism of human fibroblasts.

Resting transmembrane potential (TMP) of primary human fibroblast cells was altered in predictable directions by subjecting cell cultures to specific monophasic and biphasic waveforms. Cells electrically stimulated with an anodal pulse resulted in hyperpolarization while a cathodal waveform depolarized the TMP to below that of non-paced control cells. The biphasic waveform, consisting of an anodal pulse followed immediately by an inverse symmetric cathodal pulse, also lessened the TMP similar to that of the cathodal pulse.

Water-soluble cavitands promote hydrolyses of long-chain diesters.

Water-soluble, deep cavitands serve as chaperones of long-chain diesters for their selective hydrolysis in aqueous solution. The cavitands bind the diesters in rapidly exchanging, folded J-shape conformations that bury the hydrocarbon chain and expose each ester group in turn to the aqueous medium. The acid hydrolyses in the presence of the cavitand result in enhanced yields of monoacid monoester products.

Synthesis and Sulfur Electrophilicity of the Nuphar Thiaspirane Pharmacophore.

We describe a general method to synthesize the iminium tetrahydrothiophene embedded in the dimeric Nuphar alkaloids. In contrast to prior studies, the sulfur atom of the thiaspirane pharmacophore is shown to be electrophilic. This α-thioether reacts with thiophenol or glutathione at ambient temperature to cleave the C-S bond and form a disulfide.

Cavitands as Reaction Vessels and Blocking Groups for Selective Reactions in Water.

The majority of reactions currently performed in the chemical industry take place in organic solvents, compounds that are generally derived from petrochemicals. To promote chemical processes in water, we examined the use of synthetic, deep water-soluble cavitands in the Staudinger reduction of long-chain aliphatic diazides (C8 , C10 , and C12 ). The diazide substrates are taken up by the cavitand in D2 O in folded, dynamic conformations.

Mechanistic rationalization of unusual sigmoidal kinetic profiles in the Machetti-De Sarlo cycloaddition reaction.

Unusual sigmoidal kinetic profiles in the Machetti-De Sarlo base-catalyzed 1,3-dipolar cycloaddition of acrylamide to N-methylnitroacetamide are rationalized by detailed in situ kinetic analysis. A dual role is uncovered in which a substrate acts as a precursor to catalyze its own reaction. Such kinetic studies provide a general protocol for distinguishing among different mechanistic origins of induction periods in complex organic reactions.

Atrial burst pacing with biphasic and monophasic waveforms for atrial fibrillation.

Background: Biphasic pacing is a novel mode of pacing that was suggested to increase cardiac conduction velocity as compared with cathodal monophasic pacing. We aimed to evaluate the safety and efficacy of rapid atrial pacing to convert atrial fibrillation (AF) to normal sinus rhythm.

Methods: Multiple biphasic (anodal/cathodal), reverse biphasic (cathodal/anodal), and monophasic (cathodal) atrial pacing therapies were performed among 12 patients undergoing left atrial catheter ablation for AF.

Comparison of chronic biphasic pacing versus cathodal pacing of the right ventricle on left ventricular function in sheep after myocardial infarction.

Background: The physiological effects of biphasic pacing have not been studied in compromised hearts.

Methods: Myocardial infarction was induced in 12 sheep by high coronary artery ligation. Perioperative mortality was 33%.

Designing and implementing ethnic congregate nutrition programs for older Americans.

Montgomery County in Maryland is one of the most ethnically diverse regions in the United States. Since the 1970s, traditional American and Kosher meals have been offered at congregate sites in this County, but few seniors of varied ethnicity participated. This article describes creative approaches used in the County Senior Nutrition Program within the Older Americans Act from 1990 to 2007 to develop nutrition sites targeted to seniors in Korean, Vietnamese, and Chinese communities.

Relationship of the implantable cardioverter defibrillator and chronic resynchronization therapy: the perfect marriage?

Background: The two major modes of death in the patient with a reduced ejection fraction (EF) are death due to heart failure and death due to lethal arrhythmia, essentially the two sides of the same coin. Over the last 20 years, two therapies-cardiac resynchronization therapy (CRT) and the implantable cardioverter defibrillator (ICD)-have been developed and tested in clinical trials. They are now, in conjunction with appropriate medical therapy, the mainstays of therapy for these two commonly encountered clinical problems.

Defibrillator Versus beta-Blockers for Unexplained Death in Thailand (DEBUT): a randomized clinical trial.

Background: Sudden Unexplained Death Syndrome (SUDS) is the leading cause of death in young, healthy, Southeast Asian men. The role of an implantable cardioverter defibrillator (ICD) for mortality reduction in these patients remains unclear.

Methods And Results: The Defibrillator Versus beta-Blockers for Unexplained Death in Thailand (DEBUT) study is a randomized, clinical trial conducted in 2 phases (pilot study followed by the main trial) to compare the annual all-cause mortality rates among SUDS patients treated with beta-blockers versus that among those treated with an ICD.

Health authorities. Raising the stakes.

A survey of 25 health authorities found user groups, professional forums, newsletters, complaint scheme, roadshows and focus groups the most extensive means of consultations. The majority of health authorities had identified the parties to be consulted over strategic planning. The results suggested that consultation is being used more for service planning than strategic purposes.

Biventricular pacing in end-stage heart failure improves functional capacity and left ventricular function.

Background: Asynchronous patterns of contraction and relaxation may contribute to hemodynamic and functional impairment in heart failure. In 1993, we introduced biventricular pacing as a novel method to treat heart failure by synchronous stimulation of the right and left ventricles after an appropriate atrioventricular delay. The objectives of this study were to assess the early and long-term effects of this therapy on functional capacity and left ventricular function in patients with severe heart failure and left bundle branch block.

ICD trials: an extraordinary means of determining patient risk?

Extensive clinical experience with the implantable cardioverter defibrillator (ICD) combined with recently completed prospective, randomized trials like MADIT and AVID, have demonstrated the lifesaving efficacy of this therapy and its superiority compared to conventional medical management in treating patients at high risk of sudden arrhythmic death. This evidence has in turn spurred great interest in further ICD studies. Since the ability of the ICD to save lives is no longer in question, there is a need to reexamine the real objectives of these new studies.

Effect of varying pacing waveform shapes on propagation and hemodynamics in the rabbit heart.

The propagation characteristics of myocardium stimulated with anodal, cathodal, and equiphasic biphasic pacing pulses were examined in Langendorff-perfused rabbit hearts. Conduction velocity measurements were made using an array of bipolar extracellular electrodes, transmembrane potentials recorded using floating intracellular microelectrodes, and hemodynamics measured by fluid-filled catheter transducer systems. Anodal (A) stimulation pulses improved the electrical conduction at all the stimulus amplitudes tested in both longitudinal (e.

Overview of implantable cardioverter-defibrillator in reducing total mortality in the high-risk coronary patient.

The idea of an implantable cardioverter-defibrillator (ICD) was conceived in the mid- to late 1960s, and working circuits were built and tested at Sinai Hospital of Baltimore in the fall of 1969. After a number of years of preclinical testing, the device entered clinical trials at The Johns Hopkins Hospital in February, 1980, and received Food and Drug Administration (FDA) approval in 1985. The device appeared to be highly effective, but there was criticism that it had not been tested in a randomized fashion, and there was the feeling that drugs would eventually prove to be superior.