Richard C. Witt

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Several studies have suggested that high dietary fat intake, particularly essential fatty acids, is associated with pancreatic cancer development and growth. Our previous studies have demonstrated that blockade of either the 5-lipoxygenase (LOX) or 12-LOX pathway of arachidonic acid metabolism inhibited pancreatic cancer cell proliferation and induced(More)
Modulation of the beta-adrenergic control of cardiac L-type Ca2+ current (Ica) by human recombinant interleukin-1 beta (IL-1) was examined in adult guinea pig ventricular myocytes using the whole cell voltage-clamp technique. ICa was elicited in Cs(+)-loaded myocytes by depolarizing pulses from a holding potential of -40 mV. Isoproterenol (0.01 and 1(More)
PURPOSE The effects of leukotriene (LT) B4 and its receptor antagonist LY293111 on proliferation and apoptosis of human pancreatic cancer cells were investigated, both in vitro and in vivo. EXPERIMENTAL DESIGN Six human pancreatic cancer cell lines (MiaPaCa-2, HPAC, Capan-1, Capan-2, PANC-1, and AsPC-1) were used. Expression of LTB4 receptors, BLT1 and(More)
INTRODUCTION Triggered activity initiated from delayed after-depolarizations has been proposed as a possible cause of arrhythmias during reperfusion of ischemic myocardium. However, the potential for abnormal repolarization and early afterdepolarizations (EADs) to develop under similar conditions has not been fully explored. METHODS AND RESULTS(More)
The cellular electrophysiologic effects of exogenous phosphocreatine (PCr) were analyzed to ascertain its purported antiarrhythmic properties during myocardial ischemia and reperfusion. Transmembrane potentials were recorded from isolated guinea pig papillary muscles and Purkinje fibers studied in vitro. Under control, normoxic conditions, 10 mmol/L PCr(More)
Two inhibitors of the calcium-dependent cysteine protease, calpain, have markedly different effects on the extent of hypertrophy induced by the alpha-adrenergic agonist, phenylephrine, of cultured neonatal rat ventricular myocytes. E64c, an inhibitor of calpain and other cysteine proteases, stimulated the hypertrophy by 59%. PD 150606, a specific calpain(More)
The electrophysiologic effects of phosphocreatine were assessed in isolated, superfused guinea pig ventricular tissues to gain an insight into its purported antiarrhythmic properties. Under normal conditions, 10 mM phosphocreatine significantly increased effective refractory period by 14.0 +/- 0.4%, but under ischemic-like conditions (hypoxia, hyperkalemia,(More)
BACKGROUND Previous studies have shown that class Ic antiarrhythmic agents are effective in suppressing ectopic atrial rhythms and accessory pathway conduction. METHODS AND RESULTS To explore the potential mechanisms for their effectiveness, we investigated the concentration-dependent effects of the Ic agent flecainide acetate (0.5 to 10 micrograms/mL) on(More)