Chronic Liver Disease and Metabolic Comorbidities in Healthy Young Males Followed for 65 Years: The Manitoba Follow-up Study.

BACKGROUND & AIMS: The prevalence of chronic liver disease (CLD) is largely derived from cross-sectional epidemiologic surveys. The goal of this long-term, prospective study was to document the lifetime risk of developing chronic liver disease and determine the impact of common metabolic conditions associated with metabolic syndrome (MetS) on the development and outcomes of CLD. METHODS: 3,983 air force men were enrolled in the Manitoba Follow-up Study in 1948. The comprehensive database on results of routine physicals and health encounters was examined for evidence of CLD and MetS. The joint relationship between CLD and components of MetS on mortality was examined using Cox proportional hazard model. RESULTS: In 65 follow-up years, 5.2% of men developed CLD and 6.4% MetS. Hypertension was the strongest predictor of CLD (HR 2.958, 95% CI - 2.065 to 4.236, p < .0001), followed by insulin resistance /diabetes mellitus (IR/DM) (2.008, 95% CI - 1.332 to 3.027, p = .0009) and obesity (1.958, 95% CI - 1.419 to 2.703, p < .0001). Relative to men without MetS comorbidities, an increasing gradient of risk for CLD was apparent with increasing numbers of MetS components; the HR of 3.67, 5.97 and 14.3 for IR/DM, IR/DM + one component, and IR/DM + two or more components respectively. The relative risk of mortality in men with vs. without CLD was 3.33 (95% CI - 2.83 to 3.91, p < .0001) and 1.505 (95% CI - 1.31 to 1.73, p < .0001) in men with vs. without MetS. CONCLUSIONS: CLD and MetS independently increase the relative risk of mortality; the magnitude of the effect is greater in CLD.

Distinct Hepatitis B and HIV co-infected populations in Canada.

Due to shared modes of exposure, HIV-HBV co-infection is common worldwide. Increased knowledge of the demographic and clinical characteristics of the co-infected population will allow us to optimize our approach to management of both infections in clinical practice. The Canadian Hepatitis B Network Cohort was utilized to conduct a cross-sectional evaluation of the demographic, biochemical, fibrotic and treatment characteristics of HIV-HBV patients and a comparator HBV group. From a total of 5996 HBV-infected patients, 335 HIV-HBV patients were identified. HIV-HBV patients were characterized by older median age, higher male and lower Asian proportion, more advanced fibrosis and higher anti-HBV therapy use (91% vs. 30%) than the HBV-positive / HIV seronegative comparator group. A history of reported high-risk exposure activities (drug use, high-risk sexual contact) was more common in HIV-HBV patients. HIV-HBV patients with reported high-risk exposure activities had higher male proportion, more Caucasian ethnicity and higher prevalence of cirrhosis than HIV-HBV patients born in an endemic country. In the main cohort, age ≥60 years, male sex, elevated ALT, the presence of comorbidity and HCV seropositivity were independent predictors of significant fibrosis. HIV seropositivity was not an independent predictor of advanced fibrosis (adj OR 0.75 [95%CI: 0.34-1.67]). In conclusion, Canadian co-infected patients differed considerably from those with mono-infection. Furthermore, HIV-HBV-infected patients who report high-risk behaviours and those born in endemic countries represent two distinct subpopulations, which should be considered when engaging these patients in care.

Pharmacokinetics of a once-daily tacrolimus formulation in first nations and caucasian liver transplant recipients.

Patient ethnicity may influence the pharmacokinetics (PK) of tacrolimus. Because the Canadian First Nations (FN) constitute a large and increasing segment of the liver transplant population, we undertook to determine whether PK differences exist for a once-daily, extended release formulation of tacrolimus (Advagraf) in FN compared to Caucasian (CAUC) liver transplant recipients. Following achievement of a steady state with Advagraf, blood samples were drawn at 0, 1, 2, 4, 6, 8 and 24 hours for whole blood tacrolimus levels by commercial immunoassay and CYP3A4 and CYP3A5 allele analyses were performed by polymerase chain reactions. Nineteen subjects participated in the study (7 FN and 12 CAUC). The FN cohort had significantly higher AUC (214 ± 48 versus 168 ± 25, P < 0.05), Cmax (16.7 ± 4.4 ng/ml versus 11.3 ± 1.7 ng/ml, P < 0.05), Cmin (6.1 ± 1.0 ng/ml versus 4.7 ± 0.5 ng/ml, P < 0.05) and shorter Tmax (1.6 ± 0.2 hours versus 2.8 ± 0.3 hours, P < 0.05) values than CAUCs. CYP3A4 genotypes were C/C in both cohorts, while the CYP3A5 *1/*3 allele was present in 2/5 FN and 0/9 CAUC. The results of this study indicate that once-daily, extended release Advagraf results in higher blood tacrolimus levels and shorter times to Cmax in FN compared to CAUC liver transplant recipients.

Enhanced gemcitabine cytotoxicity with knockdown of multidrug resistance protein genes in human cholangiocarcinoma cell lines.

BACKGROUND AND AIM: Cholangiocarcinoma (CCA) is an often fatal primary cancer of the liver that tends to be resistant to chemotherapy. Multidrug resistance proteins (MRPs) contribute to the chemoresistance of these tumors. The objectives of the study were to document MRP expression profiles in two representative human intrahepatic and extrahepatic CCA cells lines (HuCCT1 and KMBC, respectively) and gemcitabine-induced cytotoxicity prior to and following MRP knockdown. METHODS: Multidrug resistance protein mRNA and protein expression were documented by real-time reverse transcription-polymerase chain reaction and western blots, respectively. MRP knockdown was achieved with lentivirus small hairpin RNA constructs. RESULTS: Prior to gemcitabine exposure, MRP1, MRP2, MRP4, MRP5, and MRP6 mRNA were expressed in HuCCT1 cells and MRP1, MRP3, MRP4, and MRP5 in KMBC cells. Following gemcitabine exposure, MRP5 and MRP6 expressions were significantly upregulated in HuCCT1 cells and MRP5 in KMBC cells. In HuCCT1 cells, although MRP5 knockdown had no effect, MRP6 knockdown significantly increased gemcitabine-induced cytotoxicity. In KMBC cells, MRP5 knockdown significantly increased gemcitabine cytotoxicity. CONCLUSIONS: Inhibition of MRP6 expression in intra-hepatic and MRP5 in extra-hepatic should be explored as potential treatments for CCA in humans.

Spontaneous Flares of Chronic Hepatitis B Virus in Hepatitis Be Antigen Negative Carriers Who Subsequently Clear Hepatitis B Surface Antigen.

BACKGROUND: Acute exacerbations of chronic hepatitis B virus (HBV) infections can occur in HBV-infected, hepatitis e antigen (HBeAg)-negative patients in the absence of recent withdrawal of antiviral or immunosuppressive therapies. Whether these spontaneous "flares" predict subsequent loss of hepatitis B surface antigen (HBsAg) has yet to be determined. OBJECTIVES: To document the percent of patients who experience spontaneous HBV flares and severity of the flares in chronic HBeAg-negative carriers. METHODS: A retrospective review of an HBV database identified and followed HBeAg-negative patients for biochemical evidence of flares (ALT > 5× normal) and subsequent HBsAg status. Patients that subsequently cleared HBsAg were matched 1:1 with those who remained HBsAg positive. RESULTS: Of 1299 HBeAg-negative patients followed for 10.2 ± 6.1 years, 88 (6.8%) developed spontaneous HBV flares. Flares occurred in 14/115 (12.2%) patients who subsequently cleared HBsAg and 4/111 (3.6%) matched patients who remained HBsAg positive (p = 0.025). The severity of flares was similar in the two study cohorts. Following multivariate analyses, only low HBV-DNA levels at baseline identified patients likely to subsequently clear HBsAg. CONCLUSIONS: Although more common in patients who subsequently clear HBsAg, spontaneous HBV flares do not predict subsequent HBsAg clearance.

Alterations in chemokine receptor CCR5 activity influence tumor cell biology in human cholangiocarcinoma cell lines.

INTRODUCTION AND OBJECTIVES: Intrahepatic (I-CCA) and extrahepatic (E-CCA) cholangiocarcinoma (CCA) have different growth patterns and risks for tumor metastasis. Inhibition and/or activation of the chemokine receptor CCR subclasses have been reported to alter tumor cell biology in non-CCA cancers. In this study we documented CCR expression profiles in representative human I-CCA and E-CCA cell lines and the in vitro effects of CCR antagonists and agonists on tumor cell biology. MATERIALS AND METHODS: CCR expression profiles were documented by real-time reverse transcription polymerase chain reaction; cell proliferation by WST-1; spheroid formation by sphere dimensions in anchorage-free medium; cell migration by wound healing and invasion by Transwell invasion chambers. RESULTS: All 10 CCR motifs (CCR1-10) were expressed in the I-CCA, HuCCT1 cell line and six (CCR4, 5, 6, 8, 9 and 10) in the E-CCA, KMBC cell line. In HuCCT1 cells, CCR5 expression was most abundant whereas in KMBC cells, CCR6 followed by CCR5 were most abundant. The CCR5 antagonist Maraviroc significantly inhibited cell proliferation, migration and invasion in HuCCT1 cells, and spheroid formation and invasion in KMBC cells. The CCR5 agonist RANTES had no effect on HuCCT1 cells but increased cell proliferation, migration and invasion of KMBC cells. CONCLUSION: These results suggest that CCR expression profiles differ in I-CCA and E-CCA. They also indicate that CCR5 antagonists and agonists have cell-specific effects but in general, CCR5 inactivation inhibits CCA tumor cell aggressiveness. Additional research is required to determine whether CCR5 inactivation is of value in the treatment of CCA in humans.

Plasma Oxylipins Levels in Nonalcoholic Fatty Liver Disease.

BACKGROUND: Activation of innate immunity by gut-derived immunogens such as lipopolysaccharides (LPS) may play an important role in the pathogenesis of nonalcoholic fatty liver disease (NAFLD). Whether NAFLD-associated lipid disturbances and polyunsaturated fatty acid (PUFA) metabolism in particular contribute to heightened innate immunity, remains to be determined. OBJECTIVE: To determine if oxylipins, metabolic products of PUFA metabolism, enhance innate immune reactivity alone and/or following exposure to LPS. METHODS: Plasma and peripheral blood mononuclear cells (PBMC) were collected from 35 NAFLD patients and 8 healthy controls. Oxylipin levels were documented by HPLC-MS/MS, cytokines (IL-1, IL-6, IL-10, and TNF-α) by ELISA, and chemokine receptors (CCR1 and CCR2) by flow cytometry. RESULTS: Mean plasma levels of four pro-inflammatory oxylipins (Tetranor 12-HETE, 20-HETE, 8-HETrE, and 7-HDoHE) were significantly elevated in NAFLD patients compared to healthy controls. However, the levels did not correlate with the severity of liver injury as reflected by serum aminotransferases, ck18M30, and Fib-4 determinations. In vitro, 20-HETE (0.01-100 nM), the plasma oxylipin with the most significantly elevated plasma levels, did not alter NAFLD or control PBMC cytokine release or enhance the increases in cytokine release following 24 h of LPS exposure. Similarly, 20-HETE alone did not alter PBMC CCR1 or CCR2 expression or LPS-induced downregulation of these receptors. CONCLUSIONS: Pro-inflammatory oxylipin levels are increased in NAFLD, but these metabolites do not appear to drive short-term direct or LPS-induced increases in PBMC cytokine release or chemotaxis.

The relative expression of hepatocellular and cholestatic liver enzymes in adult patients with liver disease.

INTRODUCTION AND OBJECTIVES: Hepatocellular liver injury is characterized by elevations in serum alanine (ALT) and aspartate (AST) aminotransferases while cholestasis is associated with elevated serum alkaline phosphatase (ALP) levels. When both sets of enzymes are elevated, distinguishing between the two patterns of liver disease can be difficult. The aim of this study was to document the predicted ranges of serum ALP values in patients with hepatocellular liver injury and ALT or AST values in patients with cholestasis. MATERIALS AND METHODS: Liver enzyme levels were documented in adult patients with various types and degrees of hepatocellular (non-alcoholic fatty liver disease, hepatitis B and C, alcohol and autoimmune hepatitis) and cholestatic (primary biliary cholangitis and primary sclerosing cholangitis) disease. RESULTS: In 5167 hepatocellular disease patients with ALT (or AST) values that were normal, 1-5×, 5-10× or >10× elevated, median (95% CI) serum ALP levels were 0.64 (0.62-0.66), 0.72 (0.71-0.73), 0.80 (0.77-0.82) and 1.15 (1.0-1.22) fold elevated respectively. In 252 cholestatic patients with ALP values that were normal, 1-5× or >5× elevated, serum ALT (or AST) values were 1.13 (0.93-1.63), 2.47 (2.13-2.70) and 4.57 (3.27-5.63) fold elevated respectively. In 56 patients with concurrent diseases, ALP levels were beyond predicted values for their hepatitis in 38 (68%) and ALT (or AST) values beyond predicted values for their cholestatic disorder in 24 (43%). CONCLUSIONS: These data provide health care providers with predicted ranges of liver enzymes in patients with hepatocellular or cholestatic liver disease and may thereby help to identify patients with concurrent forms of liver disease.

The effects of hyperthermia on human hepatocellular carcinoma stem and mature cancer cells.

INTRODUCTION AND OBJECTIVES: Hepatocellular carcinoma (HCC) can recur following radiofrequency ablation and other hyperthermic treatment modalities. Cancer stem cells (CSCs) are a subpopulation of HCC cells that are difficult to eradicate and largely responsible for tumor recurrences. Thus, the principal objective of this study was to determine whether human HCC CSCs are relatively thermal-resistant compared to non-stem or mature cancer cells (MCCs). MATERIALS AND METHODS: Epithelial cell adhesion molecule (EpCAM) positive enriched CSCs and EpCAM- MCCs were derived from a human HCC cell line using fluorescence activated cell sorting. Each cell population was exposed to 65°C heat for 0-16min and survival documented at various time points. RESULTS: Cell survival curves were similar in CSC and MCCs throughout the 16min heat exposure period. Maximum killing was obtained after 12-14min of heat exposure. Cytoprotective, heat shock proteins-70 (HSP70) and -90 (HSP90) mRNA expression were not disproportionately increased in CSCs. CONCLUSIONS: These results suggest that human HCC CSCs are not more thermal resistant than MCCs and therefore, do not support the hypothesis that HCC recurrences following hyperthermic treatment reflect CSC thermal-resistance.

In vivo 1 H MRS of human gallbladder bile in understanding the pathophysiology of primary sclerosing cholangitis (PSC): Immune-mediated disease versus bile acid-induced injury.

Primary sclerosing cholangitis (PSC) has been considered to be either an "autoimmune disease" or a "bile acid-induced injury." In vitro MRS studies on PSC patients have limitations due to the contamination of bile with contrast agent (commonly administered during endoscopic retrograde cholangiopancreatography) and/or the use of patient cohorts with other diseases as controls. The objective of this study was to quantify biliary metabolites using in vivo 1 H MRS and gain insight into the pathogenesis of PSC. Biliary metabolites in 10 PSC patients and 14 healthy controls were quantified in vivo using 1 H MRS on a 3 T MR scanner. The concentrations of total bile acids plus cholesterol, glycine-conjugated bile acids, taurine-conjugated bile acids, and choline-containing phospholipids (chol-PLs) were compared between the two groups. There were statistically significant decreases in the levels of the above mentioned biliary metabolites in the PSC patients compared with controls. The reduction in bile acid secretion in bile of PSC patients indicates accumulation of bile acids in hepatocytes. Moreover, reduction in the levels of chol-PLs in bile may increase the toxic effects of bile acids. Our findings suggest that the bile duct injury in PSC patients is most likely due to "bile acid-induced injury."

Concomitant nonalcoholic fatty liver disease does not alter the activity, severity or course of primary biliary cholangitis.

BACKGROUND & AIMS: The impact of nonalcoholic fatty liver disease (NAFLD) on the natural history of primary biliary cholangitis (PBC) has yet to be described. The aim of this study was to document the activity, severity and progression of PBC in patients with concomitant NAFLD and compare the findings to those with PBC alone. METHODS: Disease activity was assessed by serum liver enzyme levels; severity, by Fib-4 scores and percent of patients with APRI >1.5; and progression, by changes in Fib-4 and prevalence of APRI >1.5 during follow-up. RESULTS: The study populations consisted of 168 PBC alone and 68 PBC/NAFLD patients. The mean ages and gender distributions of the two cohorts were similar. At presentation, PBC alone patients had greater disease activity (higher serum ALP and GGT values, P = .003 and 0.01, respectively) and advanced disease (higher Fib-4 (P = .04) scores) than PBC/NAFLD patients. Although the prevalence of APRI >1.5 was also higher in PBC alone (11.1%) vs PBC/NAFLD (4.7%) patients, the difference was not significant (P = .16). During mean follow-up of 6.7 ± 5.5 (PBC alone) and 6.4 ± 4.4 (PBC/NAFLD) years (ranges: 0.5-21 years) annual increases in Fib-4 and prevalence of ≥ APRI 1.5 were greater in PBC alone patients but the differences did not reach statistical significance. CONCLUSIONS: The results of this retrospective, single centre study suggest that the activity, severity and progression of PBC are not adversely affected by concomitant NAFLD.

Inhibition of BMP4 and Alpha Smooth Muscle Actin Expression in LX-2 Hepatic Stellate Cells by BMP4-siRNA Lipid Based Nanoparticle.

PURPOSE: To develop and characterize vitamin A (VA)-coupled liposomes for the targeted delivery of BMP4-siRNA to hepatic stellate cells (HSC). VA was selected to increase the uptake by HSC based on their function in the storage of VA. METHODS: DOTAP/DOPE liposomes were prepared by film hydration method and their surfaces were decorated with VA. The cytotoxicity of VA-conjugated liposomes was evaluated by the WST-1 assay. Inhibition of BMP4 and α-SMA was determined by PCR and ELISA. RESULTS: VA-coated lipoplexes exhibited an average particle sizes less than 200 nm and zeta potential around +25 mV both determined using ZetaPALS. Inclusion of VA to liposomal surfaces significantly enhanced their cellular uptake without affecting cytotoxicity. VA-coupled liposomes carrying BMP4-siRNA resulted in a significant reduction in BMP4 and α-SMA at both mRNA and protein levels.  Conclusion: VA-coated liposomes were successfully designed to deliver BMP4-siRNA to specifically target HSC. The novel delivery system discussed herein may serve as a potential therapeutic strategy for the treatment of liver fibrosis in the future. This article is open to POST-PUBLICATION REVIEW. Registered readers (see "For Readers") may comment by clicking on ABSTRACT on the issue's contents page.

Predicting Pre-transplant Abstinence in Patients with Alcohol-Induced Liver Disease.

BACKGROUND: Some patients with alcohol-induced liver failure will succumb to their disease prior to demonstrating compliance with the six months abstinence rule for liver transplantation. PURPOSE: The purpose of this study was to determine whether a patient's self-reported, longest period of abstinence predicts subsequent abstinence. METHODS: Adult patients (n=63) with alcohol-induced liver disease were asked to recall their longest period of abstinence prior to their initial hepatology visit. Compliance with instructions to remain abstinent was then documented. RESULTS: Nineteen patients (30%) achieved abstinence and 44 (70%) relapsed within six months of seeing their hepatologist. Relapses were more common in patients who self-reported previous periods of abstinence exceeding six months (19/44, 43%) compared with 2/19 (11%) in those with periods of less than six months (p=0.01). Serum albumin levels were lower in relapsers but other tests of liver function (bilirubin level and international ratio of prothrombin time) and predictors of post-transplant recidivism did not associate with relapses. On multivariate analysis, self-reported abstinence (OR: 0.11, 95% CI: 0.02-0.57, p=0.008) and serum albumin levels (regression coefficient 0.113, p=0.02) predicted relapses. CONCLUSIONS: A self-reported period of abstinence in excess of six months was associated with an increased risk of subsequent relapse following a hepatologist's instructions to remain abstinent. These counter-intuitive findings should be confirmed by larger, prospective studies.

Diagnostic considerations for cholestatic liver disease.

Cholestatic liver disease results from insufficient bile synthesis, secretion and/or flow through the biliary tract. Common presenting features include fatigue, pruritus, and cholestatic liver enzyme abnormalities wherein elevations of serum alkaline phosphatase and gamma-glutamyltransferases levels exceed those of alanine and aspartate aminotransferases. With prolonged cholestasis, fat soluble vitamin deficiencies, fibrosis, cirrhosis, and, on occasion, carcinoma of the biliary tract or liver can occur. Once mechanical obstruction to bile flow has been ruled out, the majority of causes can be classified as immune-mediated, infectious, or miscellaneous. Because specific therapeutic options are increasing for many causes of cholestasis, an accurate diagnosis is an important first step towards treatment. Thus, this review focuses on the diagnostic features of non-mechanical causes of cholestasis.

Active immunization against transforming growth factor beta1 prevents hepatic fibrosis in a rat model of liver disease.

Transforming growth factor beta1 (TGF-ß1) plays an important role in hepatic fibrogenesis. In this study, we documented the effects of active immunization against TGF-ß1 on hepatic fibrosis in an animal model of chronic liver disease. BALB/c mice were immunized against 3 different peptides of TGF-ß1 ligated into hepatitis B virus core protein (HBVc). Titers of TGF-ß1 antibodies were documented by enzyme linked immunoassays and antibody activity by cell membrane receptor binding and proliferation assays. The most immunogenic recombinant HBVc + TGF-ß1 peptide (HBVc + C) then served as a vaccine in Sprague-Dawley rats with dimethylnitrosamine-induced chronic liver disease. Hepatic fibrosis was documented by serum hyaluronic acid levels, liver histology, and reverse transcriptase polymerase chain reaction for hepatic collagen I (α1) and smooth muscle alpha actin mRNA expression. Relative to control rats vaccinated with HBVc alone, recombinant HBVc + C vaccinated animals had significantly lower serum hyaluronic acid levels, less histologic evidence of hepatic fibrosis, and reduced expression of collagen I (α1) and smooth muscle alpha actin mRNA in the liver. The results of this proof-of-concept study suggest that active immunization against TGF-ß1 is a worthwhile strategy to pursue in efforts to prevent hepatic fibrosis associated with chronic liver disease.

Long-Term, Low-Dose Exposure to Microcystin-LR Does not Cause or Increase the Severity of Liver Disease in Rodents.

BACKGROUND: Acute exposure to high concentrations of microcystin-LR (MC-LR) can cause significant hepatocyte injury. AIM: To document the effects of long-term, low-dose MC-LR exposure on hepatic inflammation and fibrosis in mice with healthy and diseased livers. MATERIAL AND METHODS: Male CD1 mice (N = 20/group) were exposed to 1.0 µg/L of MC-LR in drinking water; 1.0 µg/L MC-LR plus 300 mg/L of the hepatotoxin thioacetamide (MC-LR/TAA); or 300 mg/L TAA alone for 28 weeks. Liver biochemistry and histology were documented at the end of the study period. In addition, hepatic stellate cells (HSCs), were exposed in vitro to MC-LR (0.1-10,000 µg/L) and monitored for changes in cell metabolism, proliferation and activation. RESULTS: Liver biochemistry and histology were essentially normal in MC-LR alone exposed mice. MC-LR/TAA and TAA alone exposed mice had significant hepatic inflammation and fibrosis but the extent of the changes were similar in the two groups. In vitro, MC-LR had no effect on HSC metabolism, proliferation or activation. CONCLUSION: Long-term, low-dose exposure to MC-LR is unlikely to lead to chronic liver disease in the setting of a normal liver or exacerbate existing liver disease in the setting of ongoing hepatitis.

Cancer Stem Cells are Depolarized Relative to Normal Stem Cells Derived from Human Livers.

INTRODUCTION AND AIM: The inability to distinguish cancer (CSCs) from normal stem cells (NSCs) has hindered attempts to identify safer, more effective therapies for hepatocellular carcinoma (HCC). The aim of this study was to document and compare cell membrane potential differences (PDs) of CSCs and NSCs derived from human HCC and healthy livers respectively and determine whether altered GABAergic innervation could explain the differences. MATERIAL AND METHODS: Epithelial cell adhesion molecule (EpCAM) positive stem cells were isolated from human liver tissues by magnetic bead separations. Cellular PDs were recorded by microelectrode impalement of freshly isolated cells. GABAA receptor subunit expression was documented by reverse transcriptase polymerase chain reaction (RT-PCR) and immunofluorescence. RESULTS: CSCs were significantly depolarized (-7.0 ± 1.3 mV) relative to NSCs (-23.0 ± 1.4 mV, p &lt; 0.01). The depolarized state was associated with different GABAA receptor subunit expression profiles wherein phasic transmission, represented by GAGAA α3 subunit expression, was prevalent in CSCs while tonic transmission, represented by GABAA α6 subunit expression, prevailed in NSCs. In addition, GABAA subunits α3, ß3, ϒ3 and δ were strongly expressed in CSCs while GABAA π expression was dominant in NSCs. CSCs and NSCs responded similarly to GABAA receptor agonists (ΔPD: 12.5 ± 1.2 mV and 11.0 ± 3.5 mV respectively). CONCLUSION: The results of this study indicate that CSCs are significantly depolarized relative to NSCs and these differences are associated with differences in GABAA receptor subunit expression. Together they provide new insights into the pathogenesis and possible treatment of human HCC.

Evidence of Hepatitis B Virus Infection in Cancer and Noncancer Stem Cells Associated with Human Hepatocellular Carcinoma.

Both the hepatitis B virus (HBV) and cancer stem cells (CSCs) have been independently implicated in the pathogenesis of hepatocellular carcinoma (HCC). To date, there have been no reports describing HBV infection within CSCs. In this report we describe HBV core (HBcAg) and HBx protein expression within CSCs associated with human HCC. HBV markers were also identified in nonmalignant stem cells present in adjacent nontumor tissue. These findings provide new insights into the pathogenesis of HBV-induced HCC and are potentially relevant to the treatment of both HCC and chronic HBV.

Long-term, low-dose exposure to microcystin toxin does not increase the risk of liver tumor development or growth in mice.

AIM: Cyanotoxins are biological toxins produced by cyanobacteria (blue green algae) that have been implicated in the pathogenesis of liver tumors. Based on acute toxicity studies, the World Health Organization has designated 1.0 µg/L of cyanotoxin-contaminated drinking water as the safe allowable limit for daily oral consumption. The aim of this study was to determine whether long-term exposure to this concentration of cyanotoxins is capable of initiating or promoting the growth of liver tumors. METHODS: In the present study, four groups of adult, male CD-1 mice (n = 20/group) were exposed to either drinking water alone (water group), drinking water containing 1.0 µg/L of microcystin-LR (MC-LR group), MC-LR plus the tumor promoter thioacetamide (MC-LR/TAA group) or thioacetamide alone (TAA group). Following 28 weeks of exposure, mice were killed and the livers examined for tumor number and size. RESULTS: No tumors were present in the water or MC-LR alone groups while five mice in the MC-LR/TAA group and four in the TAA alone group developed liver tumors. The mean size of the tumors in the MC-LR/TAA and TAA alone groups were similar as were the results of Ki-67 staining, number of atypical mitoses and liver cancer gene expression profiles. In vitro MC-LR (0.1-1000 µg/L) exposure did not induce malignant transformation of WB-F344 hepatic stem cells or increase the proliferative activity or invasiveness of PLC/PRF/5 malignant hepatocytes. CONCLUSION: The results of this study suggest that long-term, low dose cyanotoxin exposure is unlikely to result in liver tumor development or enhance existing tumor growth.

Prevalence of Liver Disease and Utilization of a Hepatology Consultation Service at an Urban Tertiary Care Hospital.

PURPOSE: The prevalence of liver disease and frequency of consultations to a Hepatology Consultation service for patients with liver enzyme/function abnormalities admitted to a clinical teaching unit at an urban tertiary care hospital have not been previously described. To document these data, a retrospective chart review of adult patients admitted for non-hepatobiliary problems to a general Internal Medicine clinical teaching unit at an urban, tertiary care hospital during a three month period was performed. METHODS: Laboratory test results were reviewed to determine if liver enzymes and function tests had been ordered during the first five days of admission and, in those with abnormal results, whether referrals had been sent to the hospital's Hepatology Consultation service for further investigations and/or management. RESULTS: A total of 506 admissions occurred during the study period. Of these, 452 (89%) were for patients with no known liver disease. Liver biochemistry testing was obtained in 218 (48.2%) of these individuals. In 192 (88.1%), liver enzyme or function tests were abnormal and in 91 (41.7%), both enzymes and function tests were abnormal (suggesting more advanced disease). Referrals to the Hepatology Consultation service were requested for 5/91 (5.5%) patients with more advanced disease and none with only liver enzyme or function tests abnormalities. CONCLUSIONS: Although liver enzymes and/or function test abnormalities are common in this patient population, screening for liver disease is relatively uncommon and consultation to a Hepatology Consultation service occurs in less than 10% of cases.