HGG12 and HGG42 are effective therapeutic agents in experimental organophosphate poisoning even after "aging" of the phosphonylated cholinesterase (Hauser, Kirsch, Weger, 1981). In this study we investigated their action in the isolated superior cervical ganglion of the rat (SCGR) after cholinesterase inhibition by Soman (.4 microM). As these two compounds have ganglion blocking properties (Kirsch, Weger, 1981), the action of hexamethonium bromide (C6) and atropine was also investigated and compared to theirs. The typical effects of Soman in the SCGR are a block of ganglionic transmission within 10 sec in a test train of stimuli of 6 Hz, 30 sec, and an increase of the NAD(P)H-fluorescence response up to 3 times the control value. Addition of HGG12 or HGG42 in a concentration of 30-60 microM restores transmission and decreases the metabolic response to almost normal values while obidoxime (60 microM) has no effect at all. C6 (117 microM) and to a lesser degree atropine (30-60 microM) also improve ganglionic transmission and the metabolic response in cholinesterase poisoning. The pattern of amplitudes of APs in a test train of stimuli however is only restored by the HGG compounds and a comparison of equipotent concentrations (50% inhibition of AP in unpoisoned ganglia) shows that HGG12 has the best effects in Soman poisoned SCGR. The superiority of HGG12 can be explained by an inhibitory action of HGG12 on both nicotinic and muscarinic ganglionic receptors.

Action Potentials↗

PubMedDate not supplied

Geographic variations in structure and composition of gallstones and their correlation with brittleness.

Cholesterol gallstones obtained from different geographic regions have been reported to show significant differences in their minor chemical constituents. We undertook the present study with two objectives: (i) to investigate the possible physiochemical and radiological differences between cholesterol gallstones obtained from Indian and German patients; and (ii) to compare the brittleness of the two stone groups. Forty Indian and 36 German gallstones (matched in size and shape) were subjected to assessment of physical characteristics, in vitro computed tomography (CT) and chemical analysis. German stones more often had a stone density distribution index of > or = 50 Hounsfield units (HU) (26 vs 14; P < 0.01), peripheral calcification (18 vs 9; P < 0.02), maximum CT density > or = 90 HU (17 vs 9; P < 0.05) and significant calcium carbonate (9 vs 5; P < 0.05), compared to Indian stones. The in vitro lithotripsy performed with the Siemens Lithostar Plus machine at a constant energy level showed the German stones to be more brittle (easy to fragment), more often requiring < 1000 shocks for fragmentation (25/36; 69%) compared to Indian stones (18/40; 45%, P < 0.05). Gallstones from different geographic regions may show significant variations in their physicochemical characteristics that may explain the differences in their brittleness to lithotripsy.

Calcinosis↗