Total and conjugated bilirubin contents of gall-bladder and hepatic biles before and after 24-h incubation at 37 degrees C and beta-glucuronidase activity of hepatic biles were determined in forty-eight patients divided equally into four groups: no stones or control (C), cholesterol stones (CS), black pigment stones (black PS), and brown pigment stones (brown PS). The percent conjugation of bilirubin is lower in gall-bladder biles and hepatic biles after incubation, particularly in black PS and brown PS, when compared with hepatic biles before incubation. Mean endogenous beta-glucuronidase activities at pH 5.2 were 12.0, 15.5, 44.5 and 147.7 nmol min-1 ml-1 for C, CS, black PS, and Brown PS, respectively, which correlated well with the degree of deconjugation of bilirubin in gall-bladder and hepatic biles and with the rate of deconjugation of hepatic bile incubated at 37 degrees C. Only four biles in brown PS exhibited bacterial enzyme activity. We concluded that though bacterial beta-glucuronidase might be responsible for deconjugation of bilirubin in some patients in brown PS, endogenous biliary beta-glucuronidase could play a key role in the pathogenesis of pigment cholelithiasis.
P-type arsenic doped epitaxial layers of HgCdTe have been grown by metalorganic chemical vapor deposition using two alkyl sources, tertiarybutylarsine and diethylarsine. Data are presented on Hall characteristics and arsenic concentration profiles. High activation efficiencies and hole mobilities have been obtained over the range mid-1015 to low-1017 cm−3.
1998 organo-iron compounds organo-iron compounds S 7100
-178Chiral Sulfur-Containing 1,2-Disubstituted Ferrocenes.-The synthesis and some reactions of the title compounds are presented in context with the development of ferrocene-based bidentate ligands for asymmetric catalysis. Title compound (IX) can be prepared diastereoselectively from (IVa) under chelate-controlled conditions. The formation of compound (XIII) is explained by a intermediate chiral ferrocenyl cation. -(LAGNEAU, N. M.; CHEN, Y.; ROBBEN, P. M.; SIN, H.-S.; TAKASU, K.; CHEN, J.-S.; ROBINSON, P. D.; HUA, D. H.; Tetrahedron 54 (1998) 26, 7301-7334; Dep.
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