Effects of verapamil on electrophysiological alterations induced by lysophosphatidylcholine (LPC), a toxic membrane-derived phospholipid potentially responsible for ischemia-induced arrhythmias, were evaluated in canine Purkinje fibers. LPC (10-160 microM) induced concentration-dependent decreases in resting membrane potential, action potential amplitude and maximum upstroke velocity of phase O...

To identify the effect of L-propionylcarnitine (LPC) on ischemia, 31 fasting, untreated male patients with left coronary artery disease were studied during 2 identical pacing stress tests 45 minutes before (atrial pacing test I [APST I]) and 15 minutes after (APST II) administration of 15 mg/kg of LPC or placebo. Hemodynamic, metabolic, and nuclear angiographic variables were studied before, du...

Postfilters are used in speech decoders to improve speech quality by preserving formant information and reducing noise in the valley regions. In this thesis, a new adaptive least-squares LPC-based time-domain postfilter is presented to overcome problems presented in the conventional LPC-based time-domain postfilter. Conventional LPC-based time-domain postfilter [4] produces an unpredictable spe...

Reducing the transmission bandwidth and achieving higher speech quality are primary concerns in developing new speech coding algorithms. The goal of this thesis is to improve the perceptual speech quality of algorithms that employ linear predictive coding (LPC). Most LPC-based speech coders extract parameters representing an all-pole filter. This LPC analysis is performed on each block or frame...

This paper presents a simple and e cient time domain technique to estimate an all-pole model on the melfrequency scale (Mel-LPC), and compares the recognition performance of Mel-LPC cepstrum with those of both the standard LPC mel-cepstrum and the MFCC through the Japanese dictation system (Julius) with 20,000 word vocabulary. First, the optimal value of frequency warping factor is examined in ...

Although oxidized low-density lipoprotein (LDL) and lysophosphatidylcholine (LPC) have been proposed as important mediators of the atherosclerosis, the long-term contribution to the risk of cardiovascular disease (CVD) in hemodialysis patients has not been evaluated. This study investigated the relation between oxidized LDL and LPC levels with long term risk of CVD. Plasma oxidized LDL and LPC ...

Previously we reported modulation of endothelial prostacyclin and interleukin-8 production, cyclooxygenase-2 expression and vasorelaxation by oleoyl- lysophosphatidylcholine (LPC 18:1). In the present study, we examined the impact of this LPC on nitric oxide (NO) bioavailability in vascular endothelial EA.hy926 cells. Basal NO formation in these cells was decreased by LPC 18:1. This was accompa...