Mojtaba Olyaee

Bile acid-induced necrosis in primary human hepatocytes and in patients with obstructive cholestasis.

Accumulation of bile acids is a major mediator of cholestatic liver injury. Recent studies indicate bile acid composition between humans and rodents is dramatically different, as humans have a higher percent of glycine conjugated bile acids and increased chenodeoxycholate content, which increases the hydrophobicity index of bile acids. This increase may lead to direct toxicity that kills hepatocytes, and promotes inflammation. To address this issue, this study assessed how pathophysiological concentrations of bile acids measured in cholestatic patients affected primary human hepatocytes. Individual bile acid levels were determined in serum and bile by UPLC/QTOFMS in patients with extrahepatic cholestasis with, or without, concurrent increases in serum transaminases. Bile acid levels increased in serum of patients with liver injury, while biliary levels decreased, implicating infarction of the biliary tracts. To assess bile acid-induced toxicity in man, primary human hepatocytes were treated with relevant concentrations, derived from patient data, of the model bile acid glycochenodeoxycholic acid (GCDC). Treatment with GCDC resulted in necrosis with no increase in apoptotic parameters. This was recapitulated by treatment with biliary bile acid concentrations, but not serum concentrations. Marked elevations in serum full-length cytokeratin-18, high mobility group box 1 protein (HMGB1), and acetylated HMGB1 confirmed inflammatory necrosis in injured patients; only modest elevations in caspase-cleaved cytokeratin-18 were observed. These data suggest human hepatocytes are more resistant to human-relevant bile acids than rodent hepatocytes, and die through necrosis when exposed to bile acids. These mechanisms of cholestasis in humans are fundamentally different to mechanisms observed in rodent models.

A prospective, single-blind, randomized, controlled trial of EUS-guided FNA with and without a stylet.

BACKGROUND Most endosonographers use an EUS needle with an internal stylet during EUS-guided FNA (EUS-FNA). Reinserting the stylet into the needle after every pass is tedious and time-consuming, and there are no data to suggest that it improves the quality of the cytology specimen. OBJECTIVE To compare the samples obtained by EUS-FNA with and without a stylet for (1) the degree of cellularity, adequacy, contamination, and amount of blood and (2) the diagnostic yield of malignancy. DESIGN Prospective,single-blind, randomized, controlled trial. SETTING Two tertiary care referral centers. PATIENTS Patients referred for EUS-FNA of solid lesions. INTERVENTION Patients underwent EUS-FNA of the solid lesions, and 2 passes each were made with a stylet and without a stylet in the needle. The order of the passes was randomized, and the cytopathologists reviewing the slides were blinded to the stylet status of passes. MAIN OUTCOME MEASUREMENTS Degree of cellularity, adequacy, contamination, amount of blood, and the diagnostic yield of malignancy in the specimens. RESULTS A total of 101 patients with 118 lesions were included in final analysis; 236 FNA passes were made, each with and without a stylet. No significant differences were seen in the cellularity (P = .98), adequacy of the specimen (P = .26), contamination (P = .92), or significant amount of blood (P = .61) between specimens obtained with and without a stylet. The diagnostic yield of malignancy was 55 of 236 specimens (23%) in the with-stylet group compared with 66 of 236 specimens (28%) in the without-stylet group (P = .29). LIMITATIONS Endosonographers were not blinded to the stylet status of the passes. CONCLUSIONS Using a stylet during EUS-FNA does not confer any significant advantage with regard to the quality of the specimen obtained or the diagnostic yield of malignancy. ( CLINICAL TRIAL REGISTRATION NUMBER NCT 01213290).

Comparison of morning and evening administration of rabeprazole for gastro-oesophageal reflux and nocturnal gastric acid breakthrough in patients with reflux disease: a double-blind, cross-over study.

Aim:  To assess the effect of timing of rebeprazole (RB) 20 mg/d administration on oesophageal acid exposure and nocturnal gastric acid breakthrough (NGAB) in patients with GERD.

Epidemiology of acute pancreatitis in hospitalized children in the United States from 2000-2009.

Background Single-center studies suggest an increasing incidence of acute pancreatitis (AP) in children. Our specific aims were to (i) estimate the recent secular trends, (ii) assess the disease burden, and (iii) define the demographics and comorbid conditions of AP in hospitalized children within the United States. Methods We used the Healthcare Cost and Utilization Project Kids’ Inpatient Database, Agency for Healthcare Research and Quality for the years 2000 to 2009. Extracted data were weighted to generate national-level estimates. We used the Cochrane-Armitage test to analyze trends; cohort-matching to evaluate the association of AP and in-hospital mortality, length of stay, and charges; and multivariable logistic regression to test the association of AP and demographics and comorbid conditions. Results We identified 55,012 cases of AP in hospitalized children (1–20 years of age). The incidence of AP increased from 23.1 to 34.9 (cases per 10,000 hospitalizations per year; P<0.001) and for all-diagnoses 38.7 to 61.1 (P<0.001). There was an increasing trend in the incidence of both primary and all-diagnoses of AP (P<0.001). In-hospital mortality decreased (13.1 to 7.6 per 1,000 cases, P<0.001), median length of stay decreased (5 to 4 days, P<0.001), and median charges increased (

Inhibition of Mesothelin as a Novel Strategy for Targeting Cancer Cells

14,956 to

Endoscopic Pyloric Injection of Botulinum Toxin-A for the Treatment of Postvagotomy Gastroparesis

22,663, P<0.001). Children with AP compared to those without the disease had lower in-hospital mortality (adjusted odds ratio, aOR 0.86, 95% CI, 0.78–0.95), longer lengths of stay (aOR 2.42, 95% CI, 2.40–2.46), and higher charges (aOR 1.62, 95% CI, 1.59–1.65). AP was more likely to occur in children older than 5 years of age (aORs 2.81 to 5.25 for each 5-year age interval). Hepatobiliary disease was the comorbid condition with the greatest association with AP. Conclusions These results demonstrate a rising incidence of AP in hospitalized children. Despite improvements in mortality and length of stay, hospitalized children with AP have significant morbidity.

Effect of cisapride on nocturnal transient lower oesophageal sphincter relaxations and nocturnal gastro‐oesophageal reflux in patients with oesophagitis: a double‐blind, placebo‐controlled study

Mesothelin, a differentiation antigen present in a series of malignancies such as mesothelioma, ovarian, lung and pancreatic cancer, has been studied as a marker for diagnosis and a target for immunotherapy. We, however, were interested in evaluating the effects of direct targeting of Mesothelin on the viability of cancer cells as the first step towards developing a novel therapeutic strategy. We report here that gene specific silencing for Mesothelin by distinct methods (siRNA and microRNA) decreased viability of cancer cells from different origins such as mesothelioma (H2373), ovarian cancer (Skov3 and Ovcar-5) and pancreatic cancer (Miapaca2 and Panc-1). Additionally, the invasiveness of cancer cells was also significantly decreased upon such treatment. We then investigated pro-oncogenic signaling characteristics of cells upon mesothelin-silencing which revealed a significant decrease in phospho-ERK1 and PI3K/AKT activity. The molecular mechanism of reduced invasiveness was connected to the reduced expression of β-Catenin, an important marker of EMT (epithelial-mesenchymal transition). Ero1, a protein involved in clearing unfolded proteins and a member of the ER-Stress (endoplasmic reticulum-stress) pathway was also markedly reduced. Furthermore, Mesothelin silencing caused a significant increase in fraction of cancer cells in S-phase. In next step, treatment of ovarian cancer cells (OVca429) with a lentivirus expressing anti-mesothelin microRNA resulted in significant loss of viability, invasiveness, and morphological alterations. Therefore, we propose the inhibition of Mesothelin as a potential novel strategy for targeting human malignancies.

Alteration of hepatic nuclear receptor‐mediated signaling pathways in hepatitis C virus patients with and without a history of alcohol drinking

Objectives:To evaluate the efficacy of botulinum toxin-A in the treatment of postvagotomy gastroparesis. Methods:This open-labeled trial identified and recruited 11 subjects who developed symptomatic gastroparesis after a vagotomy (9 fundoplication, 1 trauma, and 1 exploratory laparotomy). Gastroparesis was defined as an abnormal solid-phase gastric emptying test using the standardized 4-hour radionuclide eggbeater meal method and vagotomy was confirmed with a sham meal challenge test. To complete the study, subjects should have completed the 6-month follow-up visit after their pylorus was injected with botulinum toxin-A injection in a 4-quadrant manner. Patients either received 100 (n = 2) or 200 (n = 9) units of botulinum toxin. Questionnaires recorded symptom severity of gastroparesis at baseline and at monthly intervals for 6 months after the therapy was completed by the patients. Results:Of the 11 subjects initially recruited, 10 finished the 6-month follow-up visit (7 women). Mean age was 51 years (range, 31–84 years). Mean symptom score at baseline was 16 (95% CI 13–19) and showed a numerical decline to 9 (P > 0.05) over the 6-month period after the procedure (95% CI 5–13). Seven (70%) patients observed >30% improvement in the total symptom score. No complications were recorded. Conclusions:In conclusion, this open-label study in patients with postvagotomy gastroparesis patients reveals a reduction of gastroparetic symptoms at 1 and 3 months after treatment with pyloric injection of botulinum toxin-A, with return of symptoms by 6 months. Thus, botulinum toxin treatment does not produce a sustained reduction in gastroparetic symptoms in this clinical setting.

Donor PNPLA3 rs738409 genotype affects fibrosis progression in liver transplantation for hepatitis C

To investigate the effect of cisapride, a selective 5‐hydroxytryptamine‐4 receptor agonist, on the frequency of nocturnal transient lower oesophageal sphincter relaxations and oesophageal acid exposure in patients with gastro‐oesophageal reflux disease.

Emergency department visits for gastrointestinal bleeding in children: Results from the Nationwide Emergency Department Sample 2006-2011

The current study tests a hypothesis that nuclear receptor signaling is altered in chronic hepatitis C patients and that the altered pattern is specific to alcohol drinking history. The expression of a panel of more than 100 genes encoding nuclear receptors, coregulators, and their direct/indirect targets was studied in human livers. Gene expression pattern was compared between 15 normal donor livers and 23 hepatitis C virus (HCV) genotype 1–positive livers from patients without a drinking history (matched for age, sex, and body mass index). HCV infection increased the expression of nuclear receptors small heterodimer partner and constitutive androstane receptor (CAR) as well as genes involved in fatty acid trafficking, bile acid synthesis and uptake, and inflammatory response. However, the expression of retinoid X receptor (RXR) α, peroxisomal proliferator‐activated receptor (PPAR) α and β as well as steroid regulatory element‐binding protein (SREBP)‐1c was decreased in HCV‐infected livers. Gene expression pattern was compared in chronic hepatitis C patients with and without a drinking history. Alcohol drinking increased the expression of genes involved in fatty acid uptake, trafficking, and oxidation, but decreased the expression of genes responsible for gluconeogenesis. These changes were consistent with reduced fasting plasma glucose levels and altered expression of upstream regulators that include RXRα, PPARα, and CAR. The messenger RNA levels of fibroblast growth factor 21, interleukin‐10, and fatty acid synthase, which are all regulated by nuclear receptors, showed independent correlation with hepatic HCV RNA levels. Conclusion: Our findings suggest that those genes and pathways that showed altered expression could potentially be therapeutic targets for HCV infection and/or alcohol drinking‐induced liver injury. (HEPATOLOGY 2011)