The efficacy of novel metabolic targeted agents and natural plant drugs for nonalcoholic fatty liver disease treatment: A PRISMA-compliant network meta-analysis of randomized controlled trials.

BACKGROUND: Nonalcoholic fatty liver disease (NAFLD) is a highly prevalent chronic liver disease characterized by excess accumulation of fat in hepatocytes. Because no drug has been approved for NAFLD treatment, this work analyzed the effects of agents resulting from 2 research hotspots, metabolic target agents, and natural plant drugs, on NAFLD with network meta-analysis. METHODS: Public databases were searched through August 14, 2020. Randomized controlled trials that compared obeticholic acid, elafibranor, cenicriviroc, selonsertib, curcumin, silymarin, and resveratrol to placebo were included. Liver pathology improvement, hepatic biochemical indicators, and lipid metabolism indicators were analyzed. RESULTS: Thirty-five studies were included in the meta-analysis. Obeticholic acid was found to significantly increase the frequency of liver biopsy improvement compared to placebo (OR: 2.10; 95% CI: 1.60, 2.77). The ranking results among the hepatic biochemical indicators showed that obeticholic acid (94.9%) and elafibranor (86.3%) have a relative advantage in reducing alanine aminotransferase (ALT) levels, and obeticholic acid also had an advantage (95.4%) in reducing aspartate aminotransferase (AST) levels. Considering lipid metabolic indicators, elafibranor (expSMD: 0.01; 95% CI: 0.00, 0.05; SUCRA: 100%), and obeticholic acid (expSMD: 0.48; 95% CI: 0.28,0.84; SUCRA: 75.6%) significantly reduced triglyceride (TG) levels compared with placebo; moreover, obeticholic acid, but not elafibranor, caused a serious increase in total cholesterol (TC) and low-density lipoprotein cholesterol (LDL-C) levels and a decrease in high-density lipoprotein cholesterol (HDL-C) levels. CONCLUSIONS: Novel metabolic targeted agents generally have better effects than natural plant drugs, especially obeticholic acid, and elafibranor. However, obeticholic acid showed serious adverse effects such as increasing LDL-C levels and decreasing HDL-C levels. Curcumin showed potential advantages for NAFLD but lacked statistical significance.

Evolving Role for Pharmacotherapy in NAFLD/NASH.

Nonalcoholic fatty liver disease (NAFLD) is a highly prevalent, dynamic disease that occurs across the age spectrum and can lead to cirrhosis and hepatocellular carcinoma. There are currently no US Food and Drug Administration (FDA) approved treatments for NAFLD; however, this is a field of active research. This review summarizes emerging pharmacotherapies for the treatment of adult and pediatric NAFLD. Investigated pharmacotherapies predominantly target bile acid signaling, insulin resistance, and lipid handling within the liver. Three drugs have gone on to phase III trials for which results are available. Of those, obeticholic acid is the single agent that demonstrates promise according to the interim analyses of the REGENERATE trial. Obeticholic acid showed reduction of fibrosis in adults with nonalcoholic steatohepatitis (NASH) taking 25 mg daily for 18 months (n = 931, reduction in fibrosis in 25% vs. 12% placebo, P < 0.01). Ongoing phase III trials include REGENERATE and MAESTRO-NASH, which investigates thyroid hormone receptor-ß agonist MGL-3196. Outcomes of promising phase II trials in adults with NASH are also available and those have investigated agents, including the fibroblast growth factor (FGF)19 analogue NGM282, the GLP1 agonist liraglutide, the FGF21 analogue Pegbelfermin, the sodium glucose co-transporter 2 inhibitor Empagliflozin, the ketohexokinase inhibitor PF-06835919, the acetyl-coenzyme A carboxylase inhibitor GS-0976, and the chemokine receptor antagonist Cenicriviroc. Completed and ongoing clinical trials emphasize the need for a more nuanced understanding of the phenotypes of subgroups within NAFLD that may respond to an individualized approach to pharmacotherapy.

Weak acids induce PGE2 production in human oesophageal cells: novel mechanisms underlying GERD symptoms.

The role of weak acids with pH values in the range of 4-7 has been implicated in the symptoms of gastroesophageal reflux disease (GERD). Prostaglandin E2 (PGE2) is associated with heartburn symptom in GERD patients; however, the precise productive mechanisms remain unclear. In this study, we revealed that exposure to weak acids increases PGE2 production with a peak at pH 4-5, slightly in human normal oesophageal cells (Het-1A), and robustly in oesophageal squamous carcinoma cells (KYSE-270). Release of PGE2 from the oesophageal mucosa was augmented by weak acid treatment in rat. Chenodeoxycholic acid (CDCA), a bile acid, upregulated cyclooxygenase-2 (COX-2) expression in Het-1A and KYSE-270 and induced PGE2 production in KYSE-270 cells. Weak acid-induced PGE2 production was significantly inhibited by cytosolic phospholipase A2 (cPLA2), ERK, and transient receptor potential cation channel subfamily V member 4 (TRPV4), a pH-sensing ion channel, inhibitors. Hangeshashinto, a potent inhibitor of COX-2, strongly decreased weak acid- and CDCA-induced PGE2 levels in KYSE-270. These results indicated that weak acids induce PGE2 production via TRPV4/ERK/cPLA2 in oesophageal epithelial cells, suggesting a role in GERD symptoms like heartburn. Interventions targeting pH values up to 5 may be necessary for the treatment of GERD.

The safety and effectiveness of chenodeoxycholic acid treatment in patients with cerebrotendinous xanthomatosis: two retrospective cohort studies.

OBJECTIVE: To evaluate the safety and effectiveness of chenodeoxycholic acid (CDCA) treatment in patients with cerebrotendinous xanthomatosis (CTX). METHODS: Two retrospective cohort studies were conducted in CTX patients who underwent CDCA treatment: one in the Netherlands (NL; CDCA-STUK-15-001) and one in Italy (IT; CDCA-STRCH-CR-14-001). Eligible patients were aged 2-75 years, had been diagnosed with CTX, and were treated with CDCA orally for ≥1 year. The impact of CDCA treatment on biochemical markers (including serum cholestanol levels) and disease signs and symptoms were assessed, in addition to the safety and tolerability of CDCA treatment. RESULTS: A total of 35 patients were screened in the NL study and were diagnosed with CTX at 25.6 (± 13.7 SD) years on average. These patients were treated with CDCA and followed up for a median of 9.00 (range: 0.4-26.3) years. In addition, 28 patients were enrolled in the IT study and were diagnosed at 35.0 (± 11.4 SD) years on average (median duration of CDCA treatment: 5.75 [range: 0.0-25.0] years). Signs and symptoms of disease resolved, improved, or remained stable in many patients, with concomitant improvements in biochemical marker levels (serum cholestanol, p < 0.001; 7α-hydroxy-4-cholesten-3-one, p < 0.001 [IT study]). CONCLUSIONS: The outcomes of these retrospective cohort studies indicate that CDCA is effective in the long-term treatment of CTX, with an acceptable safety profile.

REGENERATE: Design of a pivotal, randomised, phase 3 study evaluating the safety and efficacy of obeticholic acid in patients with fibrosis due to nonalcoholic steatohepatitis.

BACKGROUND: Nonalcoholic steatohepatitis (NASH) is a chronic, progressive, and severe form of nonalcoholic fatty liver disease. In FLINT, obeticholic acid (OCA) treatment improved multiple histological NASH features. The design and endpoints of REGENERATE, an ongoing phase 3 study, further evaluate OCA treatment in patients with fibrosis due to NASH. AIMS: The Month 18 interim analysis assesses the effect of OCA on liver histology, defined as improvement of fibrosis by ≥1 stage with no worsening of NASH or resolution of NASH with no worsening of fibrosis. The end-of-study analyses evaluate the effect of OCA on mortality, liver-related clinical outcomes, and long-term safety. METHODS: REGENERATE is a pivotal, long-term study of ~2400 patients with NASH, including ~2100 patients with stage 2 or 3 liver fibrosis. Additionally, ~300 patients with stage 1 fibrosis and ≥1 accompanying comorbidity are included to gather information on the safety of OCA and liver disease progression. Patients are randomised 1:1:1 to receive placebo or OCA (10 or 25 mg). A liver biopsy evaluation occurs at screening, Months 18 and 48, and end of study. The duration of the study is dependent upon accrual of a predetermined number of clinical outcome events. CONCLUSIONS: REGENERATE is designed in conjunction with regulatory authorities to support regulatory approvals in NASH. This robust phase 3 study assesses the effect of OCA on liver histology as a surrogate for transplant-free survival and liver-related outcomes, including progression to cirrhosis and mortality, and will ultimately assess clinical benefit through specific evaluation of these outcomes. CLINICAL TRIAL REGISTRATION: ClinicalTrials.gov with the identifier NCT02548351.

Obeticholic acid may increase the risk of gallstone formation in susceptible patients.

BACKGROUND & AIMS: The nuclear farnesoid X receptor (FXR) agonist obeticholic acid (OCA) has been developed for the treatment of liver diseases. We aimed to determine whether OCA treatment increases the risk of gallstone formation. METHODS: Twenty patients awaiting laparoscopic cholecystectomy were randomized to treatment with OCA (25 mg/day) or placebo for 3 weeks until the day before surgery. Serum bile acids (BAs), the BA synthesis marker C4 (7α-hydroxy-4-cholesten-3-one), and fibroblast growth factor 19 (FGF19) were measured before and after treatment. During surgery, biopsies from the liver and the whole bile-filled gallbladder were collected for analyses of gene expression, biliary lipids and FGF19. RESULTS: In serum, OCA increased FGF19 (from 95.0 ±â€¯8.5 to 234.4 ±â€¯35.6 ng/L) and decreased C4 (from 31.4 ±â€¯22.8 to 2.8 ±â€¯4.0 nmol/L) and endogenous BAs (from 1,312.2 ±â€¯236.2 to 517.7 ±â€¯178.9 nmol/L; all p <0.05). At surgery, BAs in gallbladder bile were lower in patients that received OCA than in controls (OCA, 77.9 ±â€¯53.6 mmol/L; placebo, 196.4 ±â€¯99.3 mmol/L; p <0.01), resulting in a higher cholesterol saturation index (OCA, 2.8 ±â€¯1.1; placebo, 1.8 ±â€¯0.8; p <0.05). In addition, hydrophobic OCA conjugates accounted for 13.6 ±â€¯5.0% of gallbladder BAs after OCA treatment, resulting in a higher hydrophobicity index (OCA, 0.43 ±â€¯0.09; placebo, 0.34 ±â€¯0.07, p <0.05). Gallbladder FGF19 levels were 3-fold higher in OCA patients than in controls (OCA, 40.3 ±â€¯16.5 ng/L; placebo, 13.5 ±â€¯13.1 ng/ml; p <0.005). Gene expression analysis indicated that FGF19 mainly originated from the gallbladder epithelium. CONCLUSIONS: Our results show for the first time an enrichment of FGF19 in human bile after OCA treatment. In accordance with its murine homolog FGF15, FGF19 might trigger relaxation and filling of the gallbladder which, in combination with increased cholesterol saturation and BA hydrophobicity, would enhance the risk of gallstone development. LAY SUMMARY: Obeticholic acid increased human gallbladder cholesterol saturation and bile acid hydrophobicity, both decreasing cholesterol solubility in bile. Together with increased hepatobiliary levels of fibroblast growth factor 19, our findings suggest that pharmacological activation of the farnesoid X receptor increases the risk of gallstone formation. Clinical trial number: NCT01625026.

Long-term clinical impact and cost-effectiveness of obeticholic acid for the treatment of primary biliary cholangitis.

Primary biliary cholangitis (PBC) is a chronic, progressive autoimmune liver disease that mainly affects middle-aged women. Obeticholic acid (OCA), which was recently approved by the Food and Drug Administration for PBC treatment, has demonstrated positive effects on biochemical markers of liver function. Our objective was to evaluate the long-term clinical impact and cost-effectiveness of OCA as a second-line treatment for PBC in combination with ursodeoxycholic acid (UDCA) in adults with an inadequate response to UDCA. We developed a mathematical model to simulate the lifetime course of PBC patients treated with OCA+UDCA versus UDCA alone. Efficacy data were derived from the phase 3 PBC OCA International Study of Efficacy trial, and the natural history of PBC was informed by published clinical studies. Model outcomes were validated using the PBC Global Study. We found that in comparison with UDCA, OCA+UDCA could decrease the 15-year cumulative incidences of decompensated cirrhosis from 12.2% to 4.5%, hepatocellular carcinoma from 9.1% to 4.0%, liver transplants from 4.5% to 1.2%, and liver-related deaths from 16.2% to 5.7% and increase 15-year transplant-free survival from 61.1% to 72.9%. The lifetime cost of PBC treatment would increase from $63,000 to $902,000 (1,330% increment). The discounted quality-adjusted life years with UDCA and OCA+UDCA were 10.74 and 11.78, respectively, and the corresponding costs were $142,300 and $633,900, resulting in an incremental cost-effectiveness ratio of $473,400/quality-adjusted life year gained. The results were most sensitive to the cost of OCA. CONCLUSION: OCA is a promising new therapy to substantially improve the long-term outcomes of PBC patients, but at its current annual price of $69,350, it is not cost-effective using a willingness-to-pay threshold of $100,000/quality-adjusted life year; pricing below $18,450/year is needed to make OCA cost-effective. (Hepatology 2017;65:920-928).

Emerging role of obeticholic acid in the management of nonalcoholic fatty liver disease.

Nonalcoholic fatty liver disease (NAFLD) is the commonest chronic liver disease and its prevalence is increasing driven by the pandemic of obesity and type 2 diabetes mellitus. NAFLD can progress to cirrhosis and is associated with increased risk for cardiovascular disease and hepatocellular cancer. Diet and exercise are limited by suboptimal long-term adherence in patients with NAFLD. On the other hand, current pharmacological treatment of NAFLD has limited efficacy and unfavorable safety profile. In this context, obeticholic acid (OCA), a selective agonist of the farnesoid X receptors, might represent a useful option in these patients. Preclinical studies suggest that OCA improves hepatic steatosis, inflammation and fibrosis. A proof-of-concept study and the randomized, placebo-controlled Farnesoid X Receptor Ligand Obeticholic Acid in non-alcoholic steatohepatitis Treatment (FLINT) trial also showed improvements in liver histology in patients with NAFLD who received OCA. Weight loss and reduction in blood pressure were also observed. However, the effects of OCA on insulin resistance are conflicting and the lipid profile is adversely affected by this agent. In addition, pruritus is frequently observed during treatment with OCA and might lead to treatment discontinuation. However, given the limitations of existing treatments for NAFLD, OCA might represent a useful therapeutic option in selected patients with NAFLD.

Hepatotoxicity due to chenodeoxycholic acid supplementation in an infant with cerebrotendinous xanthomatosis: implications for treatment.

UNLABELLED: We present a two-week old girl who was diagnosed with cerebrotendinous xanthomatosis (CTX), an inborn error of bile acid synthesis, after a diagnostic workup for convulsions which were shown to be caused by a parechovirus encephalitis. The diagnosis of CTX was confirmed with CYP27A1 mutation analysis. She was started on chenodeoxycholic acid (CDCA) supplementation, which inhibits cholestanol production through a feedback mechanism, at the advised dosage of 15 mg/kg/day. Within 6 weeks, she developed jaundice with hepatomegaly. CDCA supplementation was stopped after which liver size and function rapidly normalised. CDCA supplementation was then restarted and maintained at 5 mg/kg/day. Cholestanol, liver enzymes and total bilirubin were frequently monitored in the patient, who is now 2.8 years of age, and have remained within normal range. Her psychomotor development has been normal. CONCLUSION: adequate metabolic control was achieved in an infant with CTX with CDCA supplementation at a dosage of 5 mg/kg/day and was well tolerated. CDCA supplementation at 15 mg/kg/day seems hepatotoxic in infants and should not be used. This is relevant in view of the possible inclusion of CTX in newborn screening programs in the near future. WHAT IS KNOWN: Cerebrotendinous xanthomatosis (CTX), an inborn error of bile acid synthesis, is a progressive neurological disorder. Symptoms of CTX can be halted, and likely prevented, with chenodeoxycholic acid (CDCA) supplementation, making CTX a good candidate for newborn screening. What is New: CDCA supplementation at the advised dosage of 15 mg/kg/day in children seems hepatoxic in infants with CTX. Adequate metabolic control in an infant with CTX was achieved with CDCA supplementation at 5 mg/kg/day and well tolerated.

Hematopoietically expressed homeobox is a target gene of farnesoid X receptor in chenodeoxycholic acid-induced liver hypertrophy.

UNLABELLED: Farnesoid X receptor (FXR/Fxr) is a bile acid-regulated nuclear receptor that promotes hepatic bile acid metabolism, detoxification, and liver regeneration. However, the adaptive pathways under conditions of bile acid stress are not fully elucidated. We found that wild-type but not Fxr knockout mice on diets enriched with chenodeoxycholic acid (CDCA) increase their liver/body weight ratios by 50% due to hepatocellular hypertrophy. Microarray analysis identified Hex (Hematopoietically expressed homeobox), a central transcription factor in vertebrate embryogenesis and liver development, as a novel CDCA- and Fxr-regulated gene. HEX/Hex was also regulated by FXR/Fxr and CDCA in primary mouse hepatocytes and human HepG2 cells. Comparative genomic analysis identified a conserved inverted repeat-1-like DNA sequence within a 300 base pair enhancer element of intron-1 in the human and mouse HEX/Hex gene. A combination of chromatin immunoprecipitation, electromobility shift assay, and transcriptional reporter assays demonstrated that FXR/Fxr binds to this element and mediates HEX/Hex transcriptional activation. CONCLUSION: HEX/Hex is a novel bile acid-induced FXR/Fxr target gene during adaptation of hepatocytes to chronic bile acid exposure.

Cerebrotendinous xanthomatosis: 11-year treatment with chenodeoxycholic acid in five patients. An electrophysiological study.

We report the electrophysiological follow-up of five cerebrotendinous xanthomatosis patients treated for 11 years with chenodeoxycholic acid (CDCA). Nerve conduction velocity (NCV) was reduced in three cases. P100 latency of visual evoked potentials was delayed in four cases, interpeaks I-III and I-V of brainstem auditory evoked potentials (BAEPs) was increased in two and interpeak N13-20 of upper limb somatosensory evoked potentials (SEPs) was slowed in one. After 4 months of therapy with CDCA, NCV was normal and did not show any significant change during the 11 years of observation. Central motor conduction time of motor evoked potentials (MEPs) and N24-P40 interpeak latency of lower limb SEPs were increased in five and four cases, respectively, in spite of 2/3-year treatment with CDCA. Improvement of evoked potentials, especially of MEPs and SEPs, was slower and continued over the whole 11-year period. The size of xanthomas slightly decreased in some patients during treatment and the clinical manifestations stabilized, avoiding progressive worsening, but there was no significant improvement in neurological deficit. Two sisters of patients who never took CDCA showed progressive worsening of clinical manifestations, upper limb SEPs and BAEPs.

Graded experimental acute pancreatitis: monitoring of a renewed rabbit model focusing on the production of interleukin-8 (IL-8) and CD11b/CD18.

OBJECTIVE: To establish and monitor a rabbit model of graded severity of acute pancreatitis to test the hypothesis that interleukin-8 (IL-8) and the adhesion molecule complex CD11b/CD18 are involved in the development of systemic complications in severe acute pancreatitis. METHODS: Acute pancreatitis induction in rabbits by duct ligation with or without infusion of 5.0% or 0.5% chenodeoxycholic acid or 0.9% saline. Control animals underwent laparotomy. The animals were monitored biochemically, histologically and immunohistochemically. RESULT: Increased serum levels of IL-8, tumour necrosis factor alpha (TNF-alpha), amylase and lipase were found in the chenodeoxycholic acid groups when compared with the saline, duct-ligated or control groups. Leukopenia, hypocalcaemia, and hyperglycaemia were marked in the 5.0% chenodeoxycholic acid group as compared to the saline, duct-ligated and control groups. Histologically, the 5.0% chenodeoxycholic acid group manifested a significant degree of pancreatic necrosis and neutrophil infiltration. The lungs of these animals showed acute lung injury and a significant up-regulation of CD11b/CD18. IL-8 was produced in pancreatic acinar and ductal cells. A significantly large output of ascitic fluid was seen in the 5.0% chenodeoxycholic acid group. CONCLUSION: The rabbit models of acute pancreatitis are reliable in that enzymatic and histological evidence of acute pancreatitis with or without systemic complications developed. IL-8 is produced locally in pancreatic acinar and ductal cells and significantly increased in peripheral blood during severe but not mild pancreatitis. The expression of the adhesion molecule complex CD11b/CB18 is significantly increased in lung tissue during severe acute pancreatitis with acute lung injury. IL-8 and CD11b/CB18 are involved in the pathogenesis of severe acute pancreatitis but not of mild oedematous pancreatitis.

[Interrelationship of reflux bile acid concentration and the gastric mucosal change with reference to the pathophysiologic significance of taurine conjugated deoxycholic acid and chenodeoxycholic acid].

Since chronic gastritis is adversely affected by reflux bile acids, we are interested in which of these bile acids cause the most damage to the gastric mucosa as ulcerogenic factors in the stomach. We examined 34 patients suffering from the peptic ulcers, and have assumed that taurine conjugated deoxycholic acid (TDC) and chenodeoxycholic acid (TCDC) may act as the mst ulcerogenic factors. Moreover TCDC was suggested to be associated with the cystic dilatation of the gastric gland. It was also suggested that TDC is involved in the increased frequency of intestinal metaplasia as a factor backgrounding cancer.

Chenodeoxycholate: the bile acid. The drug. a review.

Chenodeoxycholate (3 alpha, 7 alpha-dihydroxy-5 beta-cholanic acid) is a primary bile acid directly synthesized from cholesterol. It is an amphipathic molecule, possessing both a hydrophobic side and a polar hydrophilic side, giving it the ability to solubilize lipids in a water environment. Bile acids are necessary for the absorption of fats and fat soluble vitamins. Chenodeoxycholate inhibits the rate-limiting step of cholesterol synthesis, the formation of hydroxymethyl-glutaryl-coenzyme A. It was first reported to be useful in the dissolution of cholesterol gallstones in 1972. Today, chenodeoxycholate has other medicinal uses and is used for the management of cerebrotendinous xanthomatosis, hypertriglyceremia, congenital liver diseases, rheumatoid arthritis, and constipation. This article details some finer points of chenodeoxycholate biochemistry and physiology and discusses in some detail the current and past clinical uses of chenodeoxycholate. This is not an exhaustive discussion on gallstone dissolution therapies, but an overview of some of the lesser-known uses for this drug.

Oral bile acid treatment of biliary cholesterol stones.

Cholesterol gallbladder stones can be dissolved with chenodeoxycholic acid (CDCA) or ursodeoxycholic acid (UDCA). Response rate is 60-90%, dissolution rate 60% in stones not exceeding 1.5 cm in diameter. Mean treatment time amounts to 18 months. To improve oral litholysis: 1) UDCA was combined with the amino acid taurine, 2) CDCA and UDCA were administered in a single bedtime dose, 3) they were combined, each bile acid in half dosage, and 4) they were mixed with terpenes. Although there was some improvement with the combination therapy, final outcome is still suboptimal. Many investigations have been performed concerning gallbladder function, mucus production and nucleating factors, showing both that cholesterol supersaturation of bile is the conditio sine qua non for gallstone formation and that other factors play an additional, important role for the development of the first nidus. These factors have to be considered when therapy shall be improved. As yet oral litholysis has shown neither drug-related side effects nor lethality. It is not more expensive than surgery. Direct contact litholysis with methyl tert-butyl ether could reduce the indication for oral treatment to floating stones or patients who refuse gallbladder puncture. But although oral litholysis does not provide us with optimal results and needs further improvements, it will always keep its place in gallstone therapy.

Lichen planus associated with chenodeoxycholic acid and ursodeoxycholic acid for gallstone dissolution.

A patient who developed lichen planus while receiving chenodeoxycholic acid and ursodeoxycholic acid therapy for gallstones is described. Skin biopsy was performed and histological examination suggested a drug etiology. An association between lichen planus and liver disease is recognized, but this patient exhibited no clinical or biochemical evidence of liver disease and the rash disappeared after cessation of the bile acid therapy. Bile acids may cause lichen planus. The mechanism is unknown.

Extracorporeal shockwave lithotripsy and litholytic therapy in cholelithiasis.

Extracorporeal shockwave lithotripsy (ESWL) and litholytic therapy were used in 100 patients over a period of 16 months. ESWL was carried out with a Lithostar Plus and chenodeoxycholic acid was used as the lytic agent, given until 3 months after complete disappearance of stones. Within a period of 8-12 months, stones disappeared completely in 82 per cent of the patients who had a single stone less than or equal to 20 mm in diameter and in 50 per cent of those with a single stone greater than 20 mm in size or with multiple stones. Complications requiring surgery developed in five patients: three had acute cholecystitis and two developed acute pancreatitis. Of the patients in whom complete stone clearance was achieved, two of 11 followed up developed recurrence of stones 4 months after cessation of lytic therapy.

The lack of relationship between hepatotoxicity and lithocholic-acid sulfation in biliary bile acids during chenodiol therapy in the National Cooperative Gallstone Study.

To test whether hepatotoxicity occurring in National Cooperative Gallstone Study patients was caused by a toxic effect of chenodiol per se or of lithocholate caused by defective sulfation, bile samples were analyzed using a new high-performance liquid chromatography method that measures the proportions of the four individual lithocholate amidates (sulfated and unsulfated lithocholylglycine and lithocholyltaurine) and all common bile acid amidates. Samples were obtained from National Cooperative Gallstone Study patients (n = 17) with abnormal light microscopic liver biopsy results or major aminotransferase elevations and from a matched control group of patients (n = 14) who received similar chenodiol doses but had no evidence of liver injury. Bile samples from 45 healthy subjects were also analyzed. The analytical method was validated by showing that the percentage of chenodiol and cholic and deoxycholic acid obtained by high-performance liquid chromatography correlated highly (r greater than 0.94) with previous gas-liquid chromatography analyses of these samples by the National Cooperative Gallstone Study Reference Laboratory. No significant differences were seen between gallstone patients with and without evidence of liver injury for percent total lithocholate amidates, percent sulfated or unsulfated lithocholate amidates or percent chenodiol amidates. Lithocholate was partially sulfated in all bile samples (52% +/- 17% [mean +/- S.D., n = 50]), but the extent of sulfation varied widely between and within patients during the course of therapy. Mean values of healthy subjects were similar and also showed a wide range in the extent of lithocholate sulfation. It is concluded that (a) liver injury caused by these doses of chenodiol could not be attributed to the accumulation of unsulfated lithocholate per se in circulating bile acids; (b) liver injury appeared to be, directly or indirectly, caused by enrichment in circulating bile acids with chenodiol or chenodiol together with lithocholate, suggesting that the hepatocytes of those patients with hepatotoxicity were injured by the change induced in bile-acid metabolism by the feeding of chenodiol; and (c) about half of lithocholate amidates in bile samples were sulfated, but the extent of sulfation was highly variable both in gallstone patients and healthy subjects.

[Promoting effect of bile acids on gastric carcinogenesis induced by MNNG in rats].

The promoting effect of bile acids on the development of gastric carcinoma was examined in rats treated with N-methyl-N'-nitro-N-nitrosoguanidine (MNNG). At the first experiment, two hundred and fifteen male Wistar rats were divided into 5 groups; after oral administration MNNG (120 micrograms/ml) for 24 weeks, group 1 received tap water, group 2 administered of chenodeoxycholic acid (CDCA) solution, group 3 had deoxycholic acid (DCA) solution for the next 12 weeks. Group 4 received CDCA solution and group 5 received DCA solution for 36 weeks without MNNG. At the second experiment, fifty one rats were divided into 3 groups; for the first 12 weeks, group 1 received tap water, group 2 CDCA and group 3 DCA. These 3 groups received MNNG for the next 24 weeks followed by tap water for 12 weeks. The incidence of gastric adenocarcinoma in MNNG-treated rats was significantly higher in group 3 (63.6%) as compared with that in group 1 (36.7%) in the first experiment. No carcinoma lesions was found in groups 4 and 5. In the second experiment, no significant changes was observed among 3 groups. Undifferentiated adenocarcinomas were identified in groups 2 and 3, especially treated with MNNG plus bile acids. The result suggested a promoting effect of bile acids, especially DCA, in stomach carcinogenesis.

Estimators and tests in the analysis of multiple nonindependent 2 x 2 tables with partially missing observations.

We present methods for the analysis of a K-variate binary measure for two independent groups where some observations may be incomplete, as in the case of K repeated measures in a comparative trial. For the K 2 X 2 tables, let theta = (theta 1,..., theta K) be a vector of association parameters where theta k is a measure of association that is a continuous function of the probabilities pi ik in each group (i = 1, 2; k = 1,..., K), such as the log odds ratio or log relative risk. The asymptotic distribution of the estimates theta = (theta 1,..., theta K) is derived. Under the assumption that theta k = theta for all k, we describe the maximally efficient linear estimator theta of the common parameter theta. Tests of contrasts on the theta are presented which provide a test of homogeneity Ha: theta k = theta l for all k not equal to l. We then present maximally efficient tests of aggregate association Hb: theta = theta 0, where theta 0 is a given value. It is shown that the test of aggregate association Hb is asymptotically independent of the preliminary test of homogeneity Ha. These methods generalize the efficient estimators of Gart (1962, Biometrics 18, 601-610), and the Cochran (1954, Biometrics 10, 417-451), Mantel-Haenszel (1959, Journal of the National Cancer Institute 22, 719-748), and Radhakrishna (1965, Biometrics 21, 86-98) tests to nonindependent tables. The methods are illustrated with an analysis of repeated morphologic evaluations of liver biopsies obtained in the National Cooperative Gallstone Study.