Pyridinium aldoximes are used as antidotes to organophosphorus cholinesterase inhibitors. All pyridinium aldoximes (oximes) are highly polar quaternary ammonium compounds showing low to minimal blood-brain-barrier (BBB) penetration. Oximes are separated using reversed-phase (RP) HPLC methods and/or thin-layer chromatography (TLC). The chemical structures, elementary compositions, molecular sizes and the calculated logP values of several mono- and bis-pyridinium aldoximes are given. Chromatographic and electrophoretic analyses of oximes are detailed, including the stationary and mobile phase composition and the mode of detection. Degradation pathways and products are also discussed. To characterize oximes lipophilicity/hydrophilicity an in silico method was used and expanded as to describe organophosphorus compound adducts with several pyridinium aldoximes.
This report describes a noninvasive method by which the volume distensibility of forearm arteries can be calculated from direct measurements of pulse wave velocity. Such measurements are made at a variety of transmural arterial pressures (TMP) accomplished by placing the forearm in a cylinder and changing the pressures within. This technique eliminates arterial blood pressure as a variable, which strongly influences arterial distensibility. We studied 48 asymptomatic men and women, ages 21 to 98 years. There was considerable scatter, but significant positive relationships were demonstrated between increasing arterial distensibility and age at ambient and lower TMPs. This finding can be explained by an age-related reduction in arterial luminal diameter and an increase in arterial wall thickness which reduces arterial wall tension and more than offsets the increased stiffness produced by changes in wall composition. In six subjects, pulse tracings were simultaneously recorded on paper and analog tape. The taped curves were digitized and subjected to Fourier analysis to determine the wave velocity of individual harmonics. The characteristic wave velocity was defined and found comparable to the hand method used in the same beats (regression coefficient = + 0.97). These data indicate that the automatic and manual methods measured the same variable. (Arteriosclerosis
Objective: The objective of the present study was to examine the association of acylated and total ghrelin levels at birth in preterm infants with anthropometric features and with related hormones in infants and their mothers. Design: Prospective, descriptive study. Methods: In total 23 pregnant women and their 26 preterm infants were involved in the study (3 twin pregnancies; gestational age, 25-35 weeks). Maternal and umbilical vein blood samples were taken after the delivery. Serum acylated and total ghrelin, leptin, cortisol, insulin, GH, and glucose were determined. Results: The mean level of acylated ghrelin concentration was higher in the maternal than in the cord blood (P!0.01) and there was a significant correlation between the fetal and maternal acylated ghrelin levels (P!0.01). The total ghrelin concentration was higher in neonates than in mothers (P!0.01), but there was no correlation between them. The multivariate regression analysis for fetal acylated and maternal total ghrelin as dependent variables shows that the fetal acylated ghrelin has two independent predictors, the maternal acylated ghrelin (P!0.01) and the fetal cortisol (P!0.05), whereas the maternal total ghrelin has only one independent predictor, the maternal glucose (P!0.05). Conclusions: These data provide the first evidence that umbilical cord acylated ghrelin concentrations are lower than in maternal blood and support the hypothesis that the acylation process in the fetus is partly affected by cortisol and the placenta may play a role in this process.
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