Case definition and phenotype standardization in drug-induced liver injury.

Drug-induced liver injury (DILI) is the most frequent reason cited for the withdrawal of approved drugs from the market and accounts for up to 15% of the cases of acute liver failure. Investigators around the globe have begun to identify and study patients with DILI; several large registries and tissue banks are being established. In order to gain the maximum scientific benefit from these efforts, the definitions and terminology related to the clinical phenotypes of DILI must be harmonized. For this purpose, an international DILI Expert Working Group of clinicians and scientists reviewed current DILI terminology and diagnostic criteria so as to develop more uniform criteria that would define and characterize the spectrum of clinical syndromes that constitute DILI. Consensus was established with respect to the threshold criteria for definition of a case as being DILI, the pattern of liver injury, causality assessment, severity, and chronicity. Consensus was also reached on approaches to characterizing DILI in the setting of chronic liver diseases, including autoimmune hepatitis (AIH).

Replicated association of 17q12-21 with susceptibility of primary biliary cirrhosis in a Japanese cohort.

To examine the genetics of susceptibility to primary biliary cirrhosis (PBC), genome-wide association studies GWAS have been performed in patients of European ancestry and have shown the significant associations of IL12-related pathways, SPIB, IRF5-TNPO3, and 17q12-21. We tested whether these findings could be extended to a Japanese cohort, 303 Japanese PBC and 298 controls. We failed to detect significant associations at IL12A (rs574808, rs1075498) and IL12RB2 (rs3790567). There was no genetic variance at IRF5-TNPO3 (rs10488631) in Japanese. A single nucleotide polymorphism (SNP) at SPIB (rs3745516) reached nominal significance, but the corrected P value did not reach significance. For the 17q12-21 region, two SNPs had nominally significant associations [GSDMB (rs2305480, P = 0.022) and ZPBP2 (rs11557467, P = 0.021)] and we noted a significant P value at a SNP in IKZF3 (rs939327, P = 0.0024, P(c) = 0.017) after correction for multiple comparisons. Thus, these results indicate a haplotype on 17q12-21 with a similar association in Japanese and European PBC.

Genetic association of Fc receptor-like 3 polymorphisms with susceptibility to primary biliary cirrhosis: ethnic comparative study in Japanese and Italian patients.

A functional variant in the Fc receptor-like 3 (FCRL3) gene is associated with the susceptibility to several autoimmune diseases. In this study, we examined whether the FCRL3 is associated with susceptibility to primary biliary cirrhosis (PBC) by comparing the two different ethnic groups, Japanese and Italians. We enrolled 232 patients with PBC and 230 controls in Japanese, and 216 PBC and 180 controls in Italians. Minor allele frequency of fcrl3_3 (-169 T>C) in the patients with PBC and controls was 0.20 and 0.09 in Japanese and 0.24 and 0.21 in Italians, respectively. We found a significant association of fcrl3_3 with PBC only in Japanese (P = 9.64 × 10(-7) ). These findings support the presence of common FCRL3-related pathological pathways in several autoimmune diseases, especially in Asians.

Synthesis of methyl (5Z,9Z,17R)-17-methylnonadeca-5,9-dienoate, the (R)-enantiomer of the structure proposed for a metabolite of the Philippine sponge Plakinastrella sp.

The (R)-enantiomer (1) of methyl (5Z,9Z)-17-methylnonadeca-5,9-dienoate, the structure proposed for a metabolite of the Philippine sponge, Plakinastrella sp., was synthesized. The 1H- and 13C-NMR spectra of the synthetic material were different from those reported for the natural product. The proposed structure 1 is therefore incorrect.

Biliary excretion of tauroursodeoxycholate-3-sulfate in the rat.

Biliary organic anion excretion is mediated by an ATP-dependent primary active transporter, multidrug resistance protein 2. On the other hand, a multiplicity of canalicular organic anion transport has been suggested. Ursodeoxycholic acid, the 7beta-epimer of chenodeoxycholic acid, is clinically used for various hepatobiliary diseases. In our previous study, the contribution of multidrug resistance protein 2 for biliary excretion of taurine-conjugated bile acid sulfates depended on the numbers of hydroxyl residue. Therefore, to further examine the effect of hydrophobicity on the substrate specificity of multidrug resistance protein 2, we examined the effect of bile acid conjugates and organic anions on biliary excretion of tauroursodeoxycholate-3-sulfate, taurine and sulfonate-conjugated ursodeoxycholic acid, in rats. Biliary tauroursodeoxycholate-3-sulfate excretions was markedly delayed in Eisai hyperbilirubinemic rats. Taurolithocholate-3-sulfate inhibited but ursodeoxycholate-3,7-disulfate did not affect biliary tauroursodeoxycholate-3-sulfate excretion. Biliary tauroursodeoxycholate-3-sulfate excretion was inhibited by sulfobromophthalein, but was not inhibited by dibromosulfophthalein and cefpiramide. These findings indicate that tauroursodeoxycholate-3-sulfate is very specific for multidrug resistance protein 2.

Does pheromone biology of Lambdina athasaria and L. pellucidaria contribute to their reproductive isolation?

Recently, 7-methylheptadecane and 7,11-dimethylheptadecane have been reported as sex pheromone components of both spring hemlock looper (SHL), Lambdina athasaria, and pitch pine looper (PPL), Lambdina pellucidaria. Our objective was to test the hypothesis that SHL and PPL are reproductively isolated, in part, through species specificity in: (1) absolute configuration of pheromone components, (2) diel periodicity of pheromonal communication, and/or (3) seasonal flight period. In coupled gas chromatographic-electroantennographic detection (GC-EAD) analyses of stereoselectively synthesized (7S)- and (7R)-7-methylheptadecane [7S; 7R] as well as (7S,11S)-, (7R,11R)-, and (meso-7,11)-7,11-dimethylheptadecane [7S,11S; 7R,11R; meso-7,11], only 7S and meso-7,11 elicited responses by male SHL and PPL antennae. In field experiments, male SHL and PPL were attracted only to lures containing 7S plus meso-7,11. In hourly recordings of trap-captured males, SHL and PPL in their respective habitats were trapped between 24:00 and 03:00 hr. Capture of both SHL and PPL in pheromone-baited traps throughout June indicated overlapping seasonal flight periods. These findings of identical absolute configuration of pheromoal components, diel periodicity of pheromonal communication, and overlap of seasonal flight periods support synonymy of SHL and PPL. Finite taxonomic classification of PPL and SHL must await careful assessment of further criteria, such as morphometrics, molecular comparisons and ecological analyses.

Synthesis and absolute configuration of Stellettadine A: a marine alkaloid that induces larval metamorphosis in ascidians.

Stellettadine A, a bisguanidinium alkaloid isolated from a marine sponge Stelletta sp. as an inducer of larval metamorphosis in ascidians, and its unnatural enantiomer were synthesized from the enantiomers of citronellal. The absolute configuration of stellettadine A was established as R.

Biliary excretion of temocapril in zone 1- and zone 3-injured rat.

Temocapril is a prodrug of an angiotensin-converting enzyme inhibitor, temocaprilat, a substrate of multidrug resistance protein 2. Hepatocytes in zone 1 play a role in the uptake and biliary excretion of bile acids under physiological condition, and those in zone 3 may play a role only with their high-dose load. To investigate the pharmacokinetics of temocapril in liver injury, biliary excretion of temocapril was studied in zone 1- and zone 3-injured rats, caused by allyl alcohol and bromobenzene, respectively. Biliary excretion of a tracer dose of radiolabeled temocapril was delayed both in zone 1 and the zone 3 injury, but the extent of inhibition was more prominent in zone 3 injury. Since biliary excretion of organic anions was decreased only in zone 1 injury in our previous study, the present findings indicate that decreased biliary excretion of temocaprilat in zone 3 injury is caused by the inhibition of the metabolism from temocapril to temocaprilat.

Biliary excretion of phenolphthalein glucuronide in the rat.

To examine the substrate specificity of an ATP-dependent organic anion transporter, the multidrug resistance protein 2, we examined the effects of various bile acid conjugates and organic anions on the biliary excretion of phenolphthalein glucuronide, a hydrophilic glucuronide conjugate, in rats. Biliary phenolphthalein glucuronide excretion was markedly inhibited by taurolithocholate-3-sulfate and ursodeoxycholate-3-O-glucuronide. In contrast, ursodeoxycholate-3,7-disulfate and pravastatin only slightly inhibited and cefpiramide did not inhibit biliary phenolphthalein glucuronide excretion. Biliary excretion of sulfobromophthalein, leukotriene C(4) and pravastatin was inhibited by phenolphthalein glucuronide infusion to some extent. These findings suggest that phenolphthalein glucuronide is a relatively low affinity substrate for the multidrug resistance protein 2.

Synthesis of gibbilimbols A-D, cytotoxic and antibacterial alkenylphenols isolated from Piper gibbilimbum.

Gibbilimbols A [(E)-4-(4-decenyl)phenol, 1], B [(E)-4-(3-decenyl)phenol, 2], C [(E)-4-(4-octenyl)phenol, 3] and D [(E)-4-(3-octenyl)phenol, 4] were synthesized by coupling the phenolic parts with the alkyne parts and then reducing the triple bond of the resulting alkynylphenols. These alkenylphenols (1-4) are the cytotoxic and antibacterial constituents of the leaves of a medicinal plant (Piper gibbilimbum) that is used as a traditional medicine in Papua New Guinea.

Effect of bile acids on biliary excretion of cyclosporin A in the rat.

Cyclosporin A, a substrate of P-glycoprotein (P-gp), is known to cause cholestasis in humans and in rat experimental models. Tauroursodeoxycholate is reported to be effective in CyA-induced cholestasis in rats. In the present study, to investigate the mechanism of the inhibition of CyA induced cholestasis, effect of bile acids on biliary cyclosporin A excretion was studied in rats. Infusion of both taurocholate and tauroursodeoxycholate at the rate of 0.8 mmol/min per 100 g bodyweight increased bile flow and biliary cyclosporin A excretion, and the extent was more prominent with tauroursodeoxycholate. It was suggested that these findings were caused by the enhanced vesicular targeting of P-gp to the canalicular membrane by bile acids, thus increasing the numbers of P-gp in the canalicular membrane.

Synthesis of the enantiomers of some methyl-branched cuticular hydrocarbons of the ant, Diacamma sp..

The enantiomers of 3-methylpentacosane, 3-methylheptacosane, 3-methylnonacosane, 13-methylheptacosane, and 5-methylheptacosane were synthesized by starting from the enantiomers of 2-methylbutyl bromide or citronellol. These methyl-branched alkanes are the characteristic components of the cuticular hydrocarbons of queen of the ant, Diacamma sp..

Characterization of bile acid transport mediated by multidrug resistance associated protein 2 and bile salt export pump.

Biliary excretion of certain bile acids is mediated by multidrug resistance associated protein 2 (Mrp2) and the bile salt export pump (Bsep). In the present study, the transport properties of several bile acids were characterized in canalicular membrane vesicles (CMVs) isolated from Sprague--Dawley (SD) rats and Eisai hyperbilirubinemic rats (EHBR) whose Mrp2 function is hereditarily defective and in membrane vesicles isolated from Sf9 cells infected with recombinant baculovirus containing cDNAs encoding Mrp2 and Bsep. ATP-dependent uptake of [(3)H]taurochenodeoxycholate sulfate (TCDC-S) (K(m)=8.8 microM) and [(3)H]taurolithocholate sulfate (TLC-S) (K(m)=1.5 microM) was observed in CMVs from SD rats, but not from EHBR. In addition, ATP-dependent uptake of [(3)H]TLC-S (K(m)=3.9 microM) and [(3)H]taurocholate (TC) (K(m)=7.5 microM) was also observed in Mrp2- and Bsep-expressing Sf9 membrane vesicles, respectively. TCDC-S and TLC-S inhibited the ATP-dependent TC uptake into CMVs from SD rats with IC(50) values of 4.6 microM and 1.2 microM, respectively. In contrast, the corresponding values for Sf9 cells expressing Bsep were 59 and 62 microM, respectively, which were similar to those determined in CMVs from EHBR (68 and 33 microM, respectively). By co-expressing Mrp2 with Bsep in Sf9 cells, IC(50) values for membrane vesicles from these cells shifted to values comparable with those in CMVs from SD rats (4.6 and 1.2 microM). Moreover, in membrane vesicles where both Mrp2 and Bsep are co-expressed, preincubation with the sulfated bile acids potentiated their inhibitory effect on Bsep-mediated TC transport. These results can be accounted for by assuming that the sulfated bile acids trans-inhibit the Bsep-mediated transport of TC.

Effect of colestimide on intestinal absorption of ursodeoxycholic acid in men.

Colestimide is a new anion-exchange resin which is used to lower serum cholesterol levels in Japan. Because of its excellent compliance, colestimide can replace cholestyramine in the treatment of pruritus. However, there may be an interaction in cholestatic patients undergoing treatment with ursodeoxycholic acid (UDCA). Therefore, we studied the effect of colestimide on the absorption of UDCA in men. Five healthy men took two 100 mg tablets of UDCA after a test meal following an overnight fast, and blood samples were collected every 30 min for 3 h. Two weeks later, the same study was repeated just after taking colestimide granules (1.5 g). Bile acid subfractions in serum were measured by HPLC. Serum UDCA levels after 30 min (mainly unconjugated), which reflect the initial absorption, were decreased > 50% by colestimide in 4 out of 5 subjects. Serum total bile acid levels after 30 min, which reflect the initial absorption of bile acids due to postprandial bile secretion, were decreased by colestimide in all subjects. These results indicate that colestimide administration before the meal inhibits UDCA absorption.

Synthesis of (R)-(+)-hippospongic acid A, a triterpene isolated from the marine sponge, Hippospongia sp.

Hippospongic acid A (1) is a triterpene metabolite of the marine sponge, Hippospongia sp., with inhibitory activity against the gastrulation of starfish embryos. (R)-(+)-1 was synthesized by employing enzymatic kinetic resolution as the key step.

Synthesis of 2,2,4,4-tetramethyl-N,N'-bis(2,6-dimethylphenyl)cyclobutane-1,3-diimine , a unique compound from Arundo donax, and its analogues to test their antifeedant activity against the boll weevil, Anthonomus grandis.

2,2,4,4-Tetramethyl-N,N'-bis(2,6-dimethylphenyl) cyclobutane-1,3-diimine (1), which was isolated from the Thai plant Arundo donax as an antifeedant against the boll weevil (Anthonomus grandis), and its analogues (9-13) were synthesized and shown to possess no remarkable antifeedant activity of practical interest.

Biliary excretion of bile acids and organic anions in zone 1- and zone 3-injured rats.

AIMS: Hepatocytes in zone 1 of the hepatic lobule play a role in the uptake and biliary excretion of bile acids and organic anions under physiological conditions, and those in zone 3 may play a role only with a high-dose load. To further elucidate the role of hepatic zonation on the handling of bile acids and organic anions, biliary excretion of these compounds was studied in zone 1- and zone 3-injured rats. METHODS: Biliary excretion of bile acids and organic anions was studied in zone 1- and zone 3-injured rats, caused by allyl alcohol and bromobenzene, respectively. RESULTS: Biliary excretion of a tracer dose of taurocholate was unchanged in the injury in both zones, but that of leukotriene C4 was decreased in zone 1 injury. The excretory maximum of taurocholate was decreased with zone 1 and the zone 3 injuries. Biliary excretion of deoxycholate metabolites was decreased in zone 3 injury, although the profile of metabolites in the bile was unchanged. Sulfobromophthalein excretion was decreased in zone 1 injury, but unchanged in zone 3 injury. CONCLUSIONS: These findings indicate that zone 1 is very important for biliary excretion of both organic anions and bile acids. In contrast, zone 3 is considered not to have a role in biliary excretion of organic anions, but to play a role in the excretion of bile acids.