Helicobacter pylori CagA Promotes the Formation of Gallstones by Increasing the Permeability of Gallbladder Epithelial Cells.

BACKGROUND: The formation of gallstones is often accompanied by chronic inflammation, and the mechanisms underlying inflammation and stone formation are not fully understood. Our aim is to utilize single-cell transcriptomics, bulk transcriptomics, and microbiome data to explore key pathogenic bacteria that may contribute to chronic inflammation and gallstone formation, as well as their associated mechanisms. METHODS: scRNA-seq data from a gallstone mouse model were extracted from the Gene Expression Omnibus (GEO) database and analyzed using the FindCluster() package for cell clustering analysis. Bulk transcriptomics data from patients with gallstone were also extracted from the GEO database, and intergroup functional differences were assessed using GO and KEGG enrichment analysis. Additionally, 16S rRNA sequencing was performed on gallbladder mucosal samples from asymptomatic patients with gallstone (n = 6) and liver transplant donor gallbladder mucosal samples (n = 6) to identify key bacteria associated with stone formation and chronic inflammation. Animal models were constructed to investigate the mechanisms by which these key pathogenic bacterial genera promote gallstone formation. RESULTS: Analysis of scRNA-seq data from the gallstone mouse model (GSE179524) revealed seven distinct cell clusters, with a significant increase in neutrophil numbers in the gallstone group. Analysis of bulk transcriptomics data from patients with gallstone (GSE202479) identified chronic inflammation in the gallbladder, potentially associated with dysbiosis of the gallbladder microbiota. 16S rRNA sequencing identified Helicobacter pylori as a key bacterium associated with gallbladder chronic inflammation and stone formation. CONCLUSIONS: Dysbiosis of the gallbladder mucosal microbiota is implicated in gallstone disease and leads to chronic inflammation. This study identified H. pylori as a potential key mucosal resident bacterium contributing to gallstone formation and discovered its key pathogenic factor CagA, which causes damage to the gallbladder mucosal barrier. These findings provide important clues for the prevention and treatment of gallstones.

Immunohistochemical inflammation in histologically normal gallbladders containing gallstones.

BACKGROUND: The aim of this study was to establish features of inflammation in histologically normal gallbladders with gallstones and compare the expression of inflammatory markers in acutely and chronically inflamed gallbladders. METHODS: Immunohistochemistry was performed on formalin-fixed paraffin-embedded gallbladders for tumor necrosis factor (TNF)-α, interleukin (IL)-6, IL-2R, and substance p in three groups: Group I (n = 60) chronic cholecystitis, Group II (n = 57) acute cholecystitis and Group III (n = 45) histologically normal gallbladders with gallstones. Expression was quantified using the H-scoring system. RESULTS: Median, interquartile range expression of mucosal IL-2R in Groups I (2.65, 0.87-7.97) and II (12.30, 6.15-25.55) was significantly increased compared with group III (0.40, 0.10-1.35, p < 0.05). Submucosal IL-2R expression in Groups I (2.0, 1.12-4.95) and II (10.0, 5.95-14.30) was also significantly increased compared with Group III (0.50, 0.15-1.05, p < 0.05). There was no difference in the lymphoid cell IL-6 expression between Groups I (5.95, 1.60-18.15), II (6.10, 1.1-36.15) and III (8.30, 2.60-26.35, p > 0.05). Epithelial IL-6 expression of Group III (8.3, 2.6-26.3) was significantly increased compared with group I (0.5, 0-10.2, p < 0.05) as was epithelial TNF-α expression in Group III (85.0, 70.50-92.0) compared with Groups I (72.50, 45.25.0-85.50, p < 0.05) and II (61.0, 30.0-92.0, p < 0.05). Lymphoid cell Substance P expression in Groups I (1.90, 1.32-2.65) and II (5.62, 2.50-20.8) was significantly increased compared with Group III (1.0,1.0-1.30, p < 0.05). Epithelial cell expression of Substance P in Group III (121.7, 94.6-167.8) was significantly increased compared with Groups I (75.7, 50.6-105.3, p < 0.05) and II (78.9, 43.5-118.5, p < 0.05). CONCLUSION: Histologically normal gallbladders with gallstones exhibited features of inflammation on immunohistochemistry.

[Cystic duct carcinoma in a patient with a history of cholecystectomy: a case report].

An 83-year-old Japanese man who underwent cholecystectomy for cholecystolithiasis 17 years ago visited our hospital owing to epigastric pain. He was initially diagnosed with choledocholithiasis and acute cholangitis following white blood cell, C-reactive protein, total bilirubin, alkaline phosphatase, and γ-glutamyltranspeptidase level elevations along with common bile duct stones on computed tomography (CT). Moreover, CT, magnetic resonance imaging, endoscopic retrograde cholangiography (ERC), and endoscopic ultrasonography (EUS) also revealed a 2-cm-diameter mass arising from the remnant cystic duct. The cytology of the bile at the time of ERC was not conclusive. However, EUS-assisted fine needle aspiration (EUS-FNA) of the mass confirmed the diagnosis of adenocarcinoma of the remnant cystic duct. The patient underwent extrahepatic bile duct resection. Cystic duct carcinoma following cholecystectomy is rare. We report a case diagnosed by EUS-FNA.

Survival analysis and prognostic factors of the carcinoma of gallbladder.

BACKGROUND: The present study aims to evaluate the survival status of patients with gallbladder cancer (GBC) and explore the prognostic factors for the improvement and preventions. METHODS: The study consists of 176 patients with clinically diagnosed gallbladder cancer; the study was conducted between 2019 and 2021 registered at Kamala Nehru Memorial Cancer Hospital, Prayagraj, India. The survival rates were analyzed by the Kaplan-Meier method; survival rate difference was analyzed by log-rank test, prognosis factors; and hazard ratio for mortality outcomes was estimated using Cox regression method. RESULTS: The overall median survival time of patients was 5 months with the 1-year, 2-year, and 3-year survival rates of 24.4%, 8.5%, and 4.5%, respectively. The 3-year survival for patients with jaundice was 2.9%, liver infiltration (4.2%), gallstones (0.8%), and with advanced tumor grade (1.4%). Elderly GBC patients had lower survival rates (3.8%), while the 3-year overall survival for patients residing in urban areas dropped to zero. No patients in the tumor stage (T3/T4) and with distance metastasis stage survived in 3 years, while only 1.1% of patients with advanced nodal stage survived. On receiving surgery and radiation therapy, the 3-year survival rate increased to 19.5% and 35%, respectively. The results of multivariate analysis showed that urban region (HR = 1.568, p = 0.040), gallstone or not (1.571, p = 0.049), N stage (HR = 1.468, p = 0.029), and M stage (HR = 2.289, p < 0.0001) were independent risk factors for prognosis, while surgery or not (HR = 0.573, p = 0.030) was the protective factor for the prognosis of GBC. CONCLUSION: The overall survival of GBC in the Gangetic belt is poor. The geographical region of patients, gallstones, and N and M stage was the risk factors for prognosis, while surgery or not was the protective factor for the prognosis of GBC.

Hepatobiliary Thyroid Hormone Deficiency Impacts Bile Acid Hydrophilicity and Aquaporins in Cholestatic C57BL/6J Mice.

Women are more prone to develop either hypothyroidism or cholesterol gallstones than men. However, a male predominance in cholesterol gallstones under hypothyroidism was reported. Recently, a novel pathogenic link between thyroid hormone (TH) deficiency and cholesterol gallstones has been described in male mice. Here, we investigate if TH deficiency impacts cholesterol gallstone formation in females by the same mechanism. Three-month-old C57BL/6J mice were randomly divided into a control, a TH deficient, a lithogenic, and a lithogenic + TH deficient group and diet-treated for two, four, and six weeks. Gallstone prevalence, liver function tests, bile composition, hepatic gene expression, and gallbladder aquaporin expression and localization were investigated. Cholesterol gallstones were observed in lithogenic + TH deficient but not lithogenic only female mice. Diminished hydrophilicity of primary bile acids due to decreased gene expression of hepatic detoxification phase II enzymes was observed. A sex-specific expression and localization of hepatobiliary aquaporins involved in transcellular water and glycerol permeability was observed under TH deficient and lithogenic conditions. TH deficiency promotes cholesterol gallstone formation in female C57BL/6J mice by the same mechanism as observed in males. However, cholesterol gallstone prevalence was lower in female than male C57BL/6J mice. Interestingly, the sex-specific expression and localization of hepatobiliary aquaporins could protect female C57BL/6J mice to cholestasis and could reduce biliary water transport in male C57BL/6J mice possibly contributing to the sex-dependent cholesterol gallstone prevalence under TH deficiency.

Activation of Estrogen Receptor G Protein-Coupled Receptor 30 Enhances Cholesterol Cholelithogenesis in Female Mice.

BACKGROUND AND AIMS: Estrogen is an important risk factor for cholesterol gallstone disease because women are twice as likely as men to form gallstones. The classical estrogen receptor α (ERα), but not ERß, in the liver plays a critical role in the formation of estrogen-induced gallstones in female mice. The molecular mechanisms underlying the lithogenic effect of estrogen on gallstone formation have become more complicated with the identification of G protein-coupled receptor 30 (GPR30), an estrogen receptor. APPROACH AND RESULTS: We investigated the biliary and gallstone phenotypes in ovariectomized female GPR30-/- , ERα-/- , and wild-type mice injected intramuscularly with the potent GPR30-selective agonist G-1 at 0 or 1 µg/day and fed a lithogenic diet for 8 weeks. The activation of GPR30 by G-1 enhanced cholelithogenesis by suppressing expression of cholesterol 7α-hydroxylase, the rate-limiting enzyme for the classical pathway of bile salt synthesis. These metabolic abnormalities led to an increase in biliary cholesterol concentrations in company with hepatic hyposecretion of biliary bile salts, thereby inducing cholesterol-supersaturated gallbladder bile and accelerating cholesterol crystallization. G-1 also impairs gallbladder emptying, leading to sluggish gallbladder motility and promoting the development of biliary sludge in the early stage of gallstone formation. The prevalence rates of gallstones were 80% in wild-type and ERα-/- mice treated with G-1 compared to 10% in wild-type mice receiving no G-1. However, no gallstones were formed in GPR30-/- mice treated with G-1. CONCLUSIONS: GPR30 produces additional lithogenic actions, working independently of ERα, to increase susceptible to gallstone formation in female mice; both GPR30 and ERα are potential therapeutic targets for cholesterol gallstone disease, particularly in women and patients exposed to high levels of estrogen.

Endoscopic Biliary Large Balloon Dilation Lithotripsy for Giant and Impacted Stones Removal: A Western Series.

BACKGROUND: Endoscopic removal of packed, large, or impacted stones, in which a basket cannot be deployed or is unable to grasp the stone(s), is challenging and inevitably leads to repeated procedures such as stent insertion and extra- or intracorporal lithotripsy. In this study, we describe the results of an alternative stone disintegration technique in a considerable series of patients using an esophageal/pyloric balloon for stone fragmentation or making working space in the bile duct to allow the deployment of the basket, a technique we call endoscopic biliary large balloon lithotripsy. METHODS: We retrieved data from 1,429 endoscopic retrograde cholangiopancreatographies (ERCPs) from 2 prospective trials performed between 2014 and 2019. Patients with difficult bile duct stones, in which a balloon dilator up to 15 mm was used to crush or increase the working space parallel to the stones in the common or hepatic duct, were included in the study. RESULTS: From the 1,429 ERCPs, 299 had difficult stones (>1 cm, impacted or multiple stones). Large balloon lithotripsy was employed in 46 cases after endoscopic papillotomy and endoscopic biliary large balloon dilation with failed attempted balloon or basket stone(s) extraction. Failure to clear the bile duct at first ERCP occurred in 4 cases (91.3% of success). Complications were observed in 5 patients (10.8%; 1 perforation, 1 pancreatitis, and 3 bleedings), who were treated conservatively. CONCLUSIONS: Large balloon lithotripsy, in order to crush the stones or make working room for baskets or balloons in the bile duct, is an effective, safe, and low cost technique for impacted, packed, or giant bile duct stones.

The effect of Tauroursodeoxycholic acid (TUDCA) and gut microbiota on murine gallbladder stone formation.

INTRODUCTION AND OBJECTIVES: The incidence of gallstone-related disease steadily increased in the last few years. Here, we aimed to investigate the effect of tauroursodeoxycholic acid1 (TUDCA) on preventing cholesterol gallstones formation in high-fat fed (HFD) mice. MATERIAL AND METHODS: Specific pathogen-free male C57Bl/6 mice were fed a lithogenic diet2 (LD group) alone or in combination with TUDCA (5g/kg diet) for 8 weeks. Upon sacrifice, serum, gallbladder, liver and small intestine were collected and the formation of gallstones or crystals in the gallbladder was analyzed. Additionally, the intestinal microbiota, and bile acid composition, serum lipids and hepatic lipids were studied. RESULTS: Cholesterol gallstones with cholesterol crystals formed in mice of the LD-fed group (15/15, 100%). However, only cholesterol crystals were found in three mice without the presence of any gallstone in the TUDCA-treated group. Both serum and hepatic total cholesterol levels in the TUDCA group were significantly decreased compared with the LD group. Concomitantly, mRNA expression of Abcg5 and Abcg8 was significantly lower in the liver of the TUDCA group whilst mRNA transcripts for Abcb11, Acat2, and Cyp27 were significantly increased compared with the LD group. Additionally, the gallbladder cholesterol saturation index (1.06±0.15) in the TUDCA group was significantly decreased compared with the LD group. Interestingly, the ratio of Firmicutes/Bacteroides in the TUDCA group was increased 3x fold. CONCLUSIONS: TUDCA can inhibit the absorption and synthesis of lipids in the small intestine by improving the intestinal microbiota in HFD-fed mice, thus reducing gallstone formation.

Bile Microbiota in Patients with Pigment Common Bile Duct Stones.

BACKGROUND: Common bile duct (CBD) stone is one of the most prevalent gastroenterological diseases, but the role played by biliary microbiota in the pathogenesis of CBD stones remains obscure. The aim of this study was to investigate the characteristics of the biliary tract core microbiome and its potential association with the formation of pigment stones. METHODS: Twenty-eight patients with biliary obstruction of various causes were enrolled. Thirteen had new-onset pigment CBD stone. Of the remaining 15, four had benign biliary stricture, four had gallbladder cancer, three had pancreatic cancer, 3 had distal CBD cancer, and one had hepatocellular carcinoma. Endoscopic retrograde cholangiopancreatography was used to collect bile samples for DNA extraction, 16S ribosomal RNA gene sequencing, and bile microbiota composition analysis. RESULTS: Proteobacteria (61.7%), Firmicutes (25.1%), Bacteroidetes (5%), Fusobacteria (4.6%), and Actinobacteria (2.6%) were the most dominant phyla in the bile of the 28 study subjects. A comparison between new-onset choledocholithiasis and other causes of biliary obstruction (controls) showed Enterococcus was found to be significantly abundant in the CBD stone group at the genus level (linear discriminant analysis score = 4.38; P = 0.03). However, no other significant compositional difference was observed. CONCLUSION: This study demonstrates an abundance of microbiota in bile juice and presents a biliary microbiome composition similar to that of duodenum. The study also shows Enterococcus was significantly abundant in the bile juice of patients with a brown pigment stone than in controls, which suggests Enterococcus may play an important role in the development of pigment stones.

The effect of ursodeoxycholic acid on the relative expression of the lipid metabolism genes in mouse cholesterol gallstone models.

BACKGROUND: Many studies indicate that gallstone formation has genetic components. The abnormal expression of lipid-related genes could be the basis for particular forms of cholesterol gallstone disease. The aim of this study was to obtain insight into lipid metabolism disorder during cholesterol gallstone formation and to evaluate the effect of ursodeoxycholic acid (UDCA) on the improvement of bile lithogenicity and its potential influence on the transcription of lipid-related genes. METHODS: Gallstone-susceptible mouse models were induced by feeding with a lithogenic diet (LD) for 8 weeks. Bile and liver tissues were obtained from these mouse models after 0, 4 and 8 weeks. Bile lipids were measured enzymatically, and the cholesterol saturation index (CSI) was calculated to evaluate the bile lithogenicity by using Carey's critical tables. Real-time polymerase chain reaction (RT-PCR) was used to detect the mRNA expression levels of farnesoid X receptor (FXR), liver X receptor (LXR), adenosine triphosphate-binding cassette subfamily G member 5/8 (ABCG5/8), cholesterol 7-α hydroxylase (CYP7A1), oxysterol 7-α hydroxylase (CYP7B1), sterol 27-α hydroxylase (CYP27A1), peroxisome proliferator-activated receptor alpha (PPAR-α) and adenosine triphosphate-binding cassette subfamily B member 11 (ABCB11). RESULTS: The rate of gallstone formation was 100% in the 4-week group but only 30% in the UDCA-treated group. The UDCA-treated group had a significantly lower CSI compared with other groups. Of special note, the data on the effects of UDCA showed higher expression levels of ABCG8, ABCB11 and CYP27A1, as well as lower expression levels of LXR and PPAR-α, compared to the model control group. CONCLUSIONS: UDCA exhibits tremendously potent activity in restraining lipid accumulation, thus reversing the lithogenic effect and protecting hepatocytes from serious pathological damage. The abnormal expression of ABCG8, CYP7A1, CYP27A1, LXR and PPAR-α might lead to high lithogenicity of bile. These results are helpful in exploring new lipid metabolism pathways and potential targets for the treatment of cholesterol stones and for providing some basis for the study of the pathogenesis and genetic characteristics of cholelithiasis. Research on the mechanism of UDCA in improving lipid metabolism and bile lithogenicity may be helpful for clinical treatment and for reducing the incidence of gallstones.

Efficacy and safety of a novel topical agent for gallstone dissolution: 2-methoxy-6-methylpyridine.

BACKGROUND: Although methyl-tertiary butyl ether (MTBE) is the only clinical topical agent for gallstone dissolution, its use is limited by its side effects mostly arising from a relatively low boiling point (55 °C). In this study, we developed the gallstone-dissolving compound containing an aromatic moiety, named 2-methoxy-6-methylpyridine (MMP) with higher boiling point (156 °C), and compared its effectiveness and toxicities with MTBE. METHODS: The dissolubility of MTBE and MMP in vitro was determined by placing human gallstones in glass containers with either solvent and, then, measuring their dry weights. Their dissolubility in vivo was determined by comparing the weights of solvent-treated gallstones and control (dimethyl sulfoxide)-treated gallstones, after directly injecting each solvent into the gallbladder in hamster models with cholesterol and pigmented gallstones. RESULTS: In the in vitro dissolution test, MMP demonstrated statistically higher dissolubility than did MTBE for cholesterol and pigmented gallstones (88.2% vs. 65.7%, 50.8% vs. 29.0%, respectively; P < 0.05). In the in vivo experiments, MMP exhibited 59.0% and 54.3% dissolubility for cholesterol and pigmented gallstones, respectively, which were significantly higher than those of MTBE (50.0% and 32.0%, respectively; P < 0.05). The immunohistochemical stains of gallbladder specimens obtained from the MMP-treated hamsters demonstrated that MMP did not significantly increase the expression of cleaved caspase 9 or significantly decrease the expression of proliferation cell nuclear antigen. CONCLUSIONS: This study demonstrated that MMP has better potential than does MTBE in dissolving gallstones, especially pigmented gallstones, while resulting in lesser toxicities.

Efficacy of endoscopic ultrasound after removal of common bile duct stone.

Objective: Endoscopic retrograde cholangiopancreatography (ERCP) is a standard procedure for choledocholithiasis. Nonetheless, the recurrence rate remains quite high. This study aimed to investigate the prevalence and related factors of remnant biliary stone or sludge using endoscopic ultrasound (EUS) after the removal of common bile duct (CBD) stone and to evaluate the long-term clinical outcomes. Methods: A prospective study enrolling a consecutive series of patients who underwent ERCP for CBD stone removal was performed between June 2014 and November 2015. Following confirmation of complete CBD stone removal by the operator, EUS was performed to determine whether biliary stone or sludge remained. Patients underwent cholecystectomy if a gallstone was identified and were subsequently followed up at a regular interval of 3-6 months. We investigated whether symptomatic recurrence would occur. Results: A total of 130 patients were enrolled. The presence of remnant biliary stone or sludge after ERCP was confirmed in 36.9% (48/130) of patients. Acute angulation of the distal CBD was the sole factor associated with remnant biliary stone or sludge (p < .01). During the follow-up period, the overall recurrence rate was 17.7% (23/130). Recurrent symptomatic choledocholithiasis was predicted by remnant biliary sludge and large CBD diameter in multivariate analysis. Conclusions: Acute angulation of the distal CBD was associated with remnant biliary stone or sludge after ERCP. Remnant biliary sludge on EUS and large CBD diameter were strong predictors of symptomatic recurrence. EUS evaluation following CBD stone removal could be an effective strategy in the treatment of choledocholithiasis.

Single-operator cholangioscopy for the treatment of concomitant gallbladder stones and secondary common bile duct stones.

BACKGROUND AND AIM: This study aims to assess the clinical validity and safety of single-operator cholangioscopy system (SOCS) for the treatment of concomitant gallbladder stones and secondary common bile duct (CBD) stones. METHODS: This retrospective study included 10 consecutive patients who had small-sized stones (< 1 cm) in both the gallbladder and CBD; the patients underwent SOCS treatment from June 2016 to December 2016. The clinical validity of this minimally invasive surgery was determined by the operation success rate, stone removal rate, postoperative hospital stay, hospitalization cost, and contrast images before and after the operation. The clinical safety was evaluated by perioperative complications and outcomes, gallbladder stone recurrence, and gallbladder contractility function. RESULTS: Both the technique success rate and the stone removal rate when using SOCS was 100%. There were no serious complications that occurred during the operation; three patients developed acute cholecystitis, and four patients underwent hyperamylasemia after the surgery. The average postoperative hospital stay was 5.8 ± 1.32 days, and the average hospitalization cost was 7466 ± 566.1 dollars. In the follow-up period, which ranged from 3 to 8 months, there was no stone residuals or recurrences in the gallbladder and CBD, and no patient showed a recurrence of biliary colic. In addition, the gallbladder contractility function was proven to be normal within 3 to 6 months after the operation. CONCLUSIONS: SOCS could successfully manage concomitant gallbladder stones and secondary CBD stones and precisely protect normal biliary function.

Prospective multi-center study of surgeon's assessment of the gallbladder compared to histopathological examination to detect incidental malignancy.

PURPOSE: Routine histopathological examination after cholecystectomy for gallstones is performed despite the low rates of incidental findings of malignancy. The aim of this study was to assess predictive values of macroscopic examination of cholecystectomy specimens by surgeons in gallstone disease. METHODS: A prospective multi-center diagnostic study was carried out between December 2015 and March 2017 at four different centers. All patients undergoing cholecystectomy for gallstone disease were consecutively screened for eligibility. Patients whose ages are 18 to 80 years, and preoperative imaging findings without any pathology except cholelithiasis were included. The gallbladder was first evaluated macroscopically ex situ by two operating surgeons and rated as macroscopically benign (group S1), suspicious for a benign diagnosis (group S2), and suspicious for malignancy (group S3). Thereafter, a pathologist made a final histopathological examination whose results are grouped as chronic cholecystitis (group P1), benign or precancerous lesions in which only cholecystectomy is the adequate treatment modality (group P2), and carcinoma (group P3). Diagnostic accuracy of the surgeon's assessment to the histopathological examination was evaluated using sensitivity, specificity, positive and negative predictive values, and accuracy, and correlated by a kappa agreement coefficient. RESULTS: A total of 1112 patients were included in this trial. The specificity rates were 96.5%, 100%, and 98.7% for group S1-group S2, group S1-group S3, and group S2-group S3, respectively. Accuracy rates to detect malignancy were 100% and 95. 2% for group S1 and group S2, respectively. Kappa coefficient values were 1.0 and 0.64 for group S1-group S3 and group S2-group S3, respectively (p < 0.001 for both). CONCLUSION: Assessment of the gallbladder specimen and selective histopathological examination may be adequate after cholecystectomy for gallstone diseases. Such a procedure would have the potential to reduce costs and prevent unnecessary loss of labor productivity without affecting patients' safety. However, higher number of patients in more centers is needed to confirm this hypothesis.

Novel peroral direct digital cholangioscopy-assisted lithotripsy using a monorail technique through the overtube in patients with surgically altered anatomy (with video).

Efficacy of cholangioscopy-assisted lithotripsy for difficult stones such as huge stones, multiple large stones and an impacted stone in patients with non-altered anatomy has been reported. Herein, we describe peroral direct digital cholangioscopy (PDCS)-assisted electrohydraulic lithotripsy (EHL) with a new technique in patients with surgically altered anatomy. Five patients received PDCS-assisted EHL with the monorail technique due to failed conventional stone extraction. Balloon enteroscope was removed, leaving the stiff guidewire in the bile duct and an overtube with inflated balloons. The cholangioscope was then inserted into the bile duct over the wire through the overtube. After direct visualization of the stone, PDCS-assisted EHL was carried out. This technique was named the 'monorail technique'. Complete removal of biliary stones in one session was accomplished in four patients and only one case required two sessions. There was no adverse event in any of the cases. PDCS-assisted EHL using the monorail technique was effective and safe for difficult biliary stones in patients with surgically altered anatomy.

Activation of the Hypoxia Inducible Factor 1α Subunit Pathway in Steatotic Liver Contributes to Formation of Cholesterol Gallstones.

BACKGROUND & AIMS: Hypoxia-inducible factor 1α subunit (HIF1A) is a transcription factor that controls the cellular response to hypoxia and is activated in hepatocytes of patients with nonalcoholic fatty liver disease (NAFLD). NAFLD increases the risk for cholesterol gallstone disease by unclear mechanisms. We studied the relationship between HIF1A and gallstone formation associated with liver steatosis. METHODS: We performed studies with mice with inducible disruption of Hif1a in hepatocytes via a Cre adenoviral vector (inducible hepatocyte-selective HIF1A knockout [iH-HIFKO] mice), and mice without disruption of Hif1a (control mice). Mice were fed a diet rich in cholesterol and cholate for 1 or 2 weeks; gallbladders were collected and the number of gallstones was determined. Livers and biliary tissues were analyzed by histology, quantitative reverse-transcription polymerase chain reaction, immunohistochemistry, and immunoblots. We measured concentrations of bile acid, cholesterol, and phospholipid in bile and rates of bile flow. Primary hepatocytes and cholangiocytes were isolated and analyzed. HIF1A was knocked down in Hepa1-6 cells with small interfering RNAs. Liver biopsy samples from patients with NAFLD, with or without gallstones, were analyzed by quantitative reverse-transcription polymerase chain reaction. RESULTS: Control mice fed a diet rich in cholesterol and cholate developed liver steatosis with hypoxia; levels of HIF1A protein were increased in hepatocytes around central veins and 90% of mice developed cholesterol gallstones. Only 20% of the iH-HIFKO mice developed cholesterol gallstones. In iH-HIFKO mice, the biliary lipid concentration was reduced by 36%, compared with control mice, and bile flow was increased by 35%. We observed increased water secretion from hepatocytes into bile canaliculi to mediate these effects, resulting in suppression of cholelithogenesis. Hepatic expression of aquaporin 8 (AQP8) protein was 1.5-fold higher in iH-HIFKO mice than in control mice. Under hypoxic conditions, cultured hepatocytes increased expression of Hif1a, Hmox1, and Vegfa messenger RNAs (mRNAs), and down-regulated expression of AQP8 mRNA and protein; AQP8 down-regulation was not observed in cells with knockdown of HIF1A. iH-HIFKO mice had reduced inflammation and mucin deposition in the gallbladder compared with control mice. Liver tissues from patients with NAFLD with gallstones had increased levels of HIF1A, HMOX1, and VEGFA mRNAs, compared with livers from patients with NAFLD without gallstones. CONCLUSIONS: In steatotic livers of mice, hypoxia up-regulates expression of HIF1A, which reduces expression of AQP8 and concentrates biliary lipids via suppression of water secretion from hepatocytes. This promotes cholesterol gallstone formation. Livers from patients with NAFLD and gallstones express higher levels of HIF1A than livers from patients with NAFLD without gallstones.

Genetic determinants of cholangiopathies: Molecular and systems genetics.

Familial cholangiopathies are rare but potentially severe diseases. Their spectrum ranges from fairly benign conditions as, for example, benign recurrent intrahepatic cholestasis to low-phospholipid associated cholelithiasis and progressive familial intrahepatic cholestasis (PFIC). Many cholangiopathies such as primary biliary cholangitis (PBC) or primary sclerosing cholangitis (PSC) affect first the bile ducts ("ascending pathophysiology") but others, such as PFIC, start upstream in hepatocytes and cause progressive damage "descending" down the biliary tree and leading to end-stage liver disease. In recent years our understanding of cholestatic diseases has improved, since we have been able to pinpoint numerous disease-causing mutations that cause familial cholangiopathies. Accordingly, six PFIC subtypes (PFIC type 1-6) have now been defined. Given the availability of genotyping resources, these findings can be introduced in the diagnostic work-up of patients with peculiar cholestasis. In addition, functional studies have defined the pathophysiological consequences of some of the detected variants. Furthermore, ABCB4 variants do not only cause PFIC type 3 but confer an increased risk for chronic liver disease in general. In the near future these findings will serve to develop new therapeutic strategies for patients with liver diseases. Here we present the latest data on the genetic background of familial cholangiopathies and discuss their application in clinical practice for the differential diagnosis of cholestasis of unknown aetiology. As look in the future we present "system genetics" as a novel experimental tool for the study of cholangiopathies and disease-modifying genes. This article is part of a Special Issue entitled: Cholangiocytes in Health and Disease edited by Jesus Banales, Marco Marzioni, Nicholas LaRusso and Peter Jansen.

Activation of Constitutive Androstane Receptor Prevents Cholesterol Gallstone Formation.

Cholesterol gallstone disease (CGD) is one of the most common gastrointestinal diseases. Lithogenic hepatic bile secretion precedes the formation of cholesterol gallstones. Constitutive androstane receptor (CAR), a member of nuclear family, plays an important role in cholesterol and bile acid metabolism. To examine whether activation of CAR can prevent cholesterol gallstone formation, we treated C57BL6/J mice maintained on a lithogenic diet with CAR agonist 1,4-bis-[2-(3, 5-dichlorpyridyloxy)] benzene and performed bile duct cannulation to study the dynamics of biliary lipids. We report that activation of CAR decreases the biliary cholesterol concentration and prevents CGD formation. The lower biliary cholesterol level was largely attributed to suppressed Abcg5 and Abcg8 expression in CAR-activated mice. CAR activation also promoted cholesterol conversion into bile acids by increasing the expression of Cyp7a1, a rate-limiting enzyme in bile acid biosynthesis. Activation of CAR enhanced bile acid re-absorption via increasing the expression of bile acid transporters Asbt and Ostß in the ileum. The hepatic steatosis was also improved in the liver of CAR-activated mice. Furthermore, activation of CAR protected the mice against the liver X receptor α-sensitized CGD through suppressing the expression of Abcg5/8. Collectively, CAR plays an important role in maintaining the homeostasis of cholesterol, bile acids, and triglycerides levels, and it might be a promising therapeutic target for preventing or treating CGD.

Evaluation of risk factors for recurrent primary common bile duct stone in patients with cholecystectomy.

OBJECTIVES: Recurrence of primary common bile duct (CBD) stone commonly occurs after complete removal of CBD stones in patients with cholecystectomy. This study aimed to investigate potential risk factors for the recurrence of primary CBD stones after endoscopic treatment. MATERIALS AND METHODS: Between January 2005 and December 2015, the endoscopic retrograde cholangiopancreatography (ERCP) database of our medical center was retrospectively reviewed; information regarding eligible patients who had recurrent CBD stones with a history of previous cholecystectomy was collected. The characteristics of the patients, CBD stone, CBD and ERCP-related factors were analyzed. RESULTS: The recurrence rate of CBD stone was 18.5% (115/622) after endoscopic treatment in patients with cholecystectomy. In univariate analysis, the number of CBD stones (≥2), CBD stone diameter (≥10 mm), stone composition, stone consistency, CBD diameter (≥15 mm), bile duct dilatation pattern, sharp bile duct angulation (<145°), balloon dilatation, large balloon (>12 mm) dilatation, endoscopic mechanical lithotripsy, endoscopic sphincterotomy, and endoscopic papillary balloon dilatation alone method were significant between the non-recurrence and recurrence groups. However, in multivariate analysis (based on the binary logistic regression method), the number of CBD stones (≥2) (adjusted odds ratio [AOR] 3.232; 95% confidence interval [CI] 1.344-7.773; p = .009), cholesterol stone (AOR 2.824; 95% CI 1.175-6.786; p =.02) and sharp bile duct angulation (<145°) (AOR 2.462; 95% CI 1.062-5.711; p = .036) were independent risk factors of CBD stone recurrence after cholecystectomy. CONCLUSIONS: CBD stone number (≥2), cholesterol stone and sharp bile duct angulation (<145°) are associated with recurrent common bile duct stones after cholecystectomy.

Factors Associated with Premalignant Epithelial Changes in Chronic Calculous Cholecystitis: A Case-Control Study.

INTRODUCTION: Gallstones are known to be associated with premalignant changes in the gallbladder epithelium that range from atypical hyperplasia, metaplasia, dysplasia to carcinoma. Recognition of factors associated with these changes in patients with gallstones can potentially be helpful in identifying patients to whom prophylactic cholecystectomy can be offered to reduce the chances of developing carcinoma. OBJECTIVE: To identify factors associated with premalignant epithelial changes including atypical hyperplasia, metaplasia, and dysplasia in gallbladder mucosa in patients with chronic calculus cholecystitis. MATERIALS AND METHODS: This was retrospective case-control study conducted over a period of 10 years from 2004 to 2014. Cases were patients with reported histopathological premalignant epithelial changes along with chronic calculus cholecystitis, and controls were patients without premalignant epithelial changes but chronic calculus cholecystitis. Controls were twice the number of the cases. RESULTS: Over study period, 92 patients were reported to have premalignant epithelial changes on gall bladder histopathology for whom 184 controls were selected. Of cases, 61 (66%) patients had atypical hyperplasia, while metaplasia and dysplasia were present in 26 (28%) and 5 (5%) cases, respectively. Mean age was 47.5 ± 14.5 years, and 74% of the study population were female. Wall thickness of more than 3 mm (OR = 4.14, p value < 0.001) turned out to be statistically significant independent variables associated with premalignant lesions in gallbladder mucosa. CONCLUSION: Odds of premalignant epithelial change in gall bladder mucosa in patients with gall bladder wall thickness of more than 3 mm is four times the odds of patients with wall thickness less than 3 mm, and the effect is statistically significant. Prophylactic cholecystectomy should be considered for this group of patients.