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Featured researches published by Assaf Stein.


World Journal of Gastroenterology | 2012

Effect of ezetimibe on the prevalence of cholelithiasis

Assaf Stein; Doron Hermoni; Avishay Elis; Fred M. Konikoff

AIM To investigate the prevalence of cholelithiasis among patients treated with ezetimibe. METHODS A retrospective, case-control study based on computerized medical records from patients of the Clalit Health Services, Sharon-Shomron region, from 2000 to 2009. Patients 20-85 years of age, who had been treated with ezetimibe and statins or statins only for at least 6 mo, and who had an abdominal ultrasound were included in the study. Collected data included age, gender, ezetimibe treatment duration, presence of hypothyroidism or diabetes, and existence of cholelithiasis as determined by ultrasound. Excluded were subjects after gallbladder resection, with hemolysis, myeloproliferative or inflammatory bowel diseases, and those treated with ursodeoxycholic acid and fibrates. Patients treated with statins and ezetimibe (study group) were compared to patients treated with statins only (control group). RESULTS The study group included 25 patients and the control group 168. All patients in the study were treated with statins. The study group included 13 males (52%) and 12 females (48%), the control group 76 males (45%) and 92 (55%) females (P = 0.544). The groups did not differ in age (mean age: 68 ± 8 years, range 53-85 years vs mean age: 71 ± 8 years, range 51-85 years; P = 0.153) or in the rate of diabetic and hypothyroid patients [11 (44%) vs 57 (33%), P = 0.347 in the study group and 5 (20%) vs 23 (14%), P = 0.449 in the control group, respectively]. Patients in the study group were treated with ezetimibe for an average of 798 ± 379 d. Cholelithiasis was found in 4 (16%) patients in the study group and in 33 (20%) patients in the control group (P = 0.666). CONCLUSION Ezetimibe does not appear to influence the prevalence of gallstones.


Gene | 2013

Increased TERC gene copy number and cells in senescence in primary sclerosing cholangitis compared to colitis and control patients

Ido Laish; Hila Katz; Yael Sulayev; Meytal Liberman; Timna Naftali; Fabiana Benjaminov; Assaf Stein; Yona Kitay-Cohen; Tal Biron-Shental; Fred M. Konikoff; Aliza Amiel

OBJECTIVE Primary sclerosing cholangitis (PSC) is a chronic cholestatic disorder that involves inflammatory and fibrotic changes in the bile ducts. Up to 80% of patients have concomitant inflammatory bowel disease (IBD) with colitis. PSC patients are predisposed to develop hepatobiliary, colonic and other extrahepatic malignancies, probably related to inflammatory processes that might promote carcinogenesis. Telomerase is an enzyme complex that lengthens telomeres and has enhanced expression in numerous malignancies. In this study, we evaluated the TERC gene copy number, the proportion of cells in senescence and the amount of fragmentation in the senescent state. METHODS Fluorescence in situ hybridization (FISH) for the TERC gene was applied to lymphocytes retrieved from PSC (N=19), colitis (N=20) and healthy control patients (N=20) to determine the TERC copy number. On the same FISH slides, cells stained with DAPI were also analyzed for senescence-associated heterochromatin foci (SAHF) status, including the number of cells with fragments and the number of SAHF fragments in each cell. RESULTS A higher TERC gene copy number was observed in cells from PSC patients compared to colitis and control group patients. It was also higher in the colitis than in the control group. Significantly more cells in the senescent state and more fragmentation in each cell were observed in the PSC group compared to colitis and control groups. CONCLUSION The TERC gene copy number and the number of cells in the senescent state were increased in PSC patients compared to the colitis and control groups. These findings are probably related to the genetic instability parameters that reflect the higher tendency of this patient group to develop malignancies.


Digestive and Liver Disease | 2015

Telomere dysfunction in peripheral blood lymphocytes from patients with primary sclerosing cholangitis and inflammatory bowel disease

Ido Laish; Hila Katz; Assaf Stein; Meytal Liberman; Timna Naftali; Yona Kitay-Cohen; Tal Biron-Shental; Fred M. Konikoff; Aliza Amiel

BACKGROUND AND AIMS Primary sclerosing cholangitis and inflammatory bowel disease are two associated, chronic inflammatory, pre-malignant conditions. We hypothesized that patients with these disorders may harbour telomere dysfunction as a marker of chromosomal instability. The aim of our study was to compare parameters of the telomere-telomerase system in these cohorts. METHODS In this prospective study, peripheral blood was withdrawn from patients with primary sclerosing cholangitis (N=20), inflammatory bowel disease (N=20) and healthy controls (N=20), and lymphocytes were isolated. Telomere length was quantified as a function of the signal intensity and telomere number. Random aneuploidy and telomere capture were determined by fluorescence in situ hybridization technique with specific probes. RESULTS Patients with inflammatory bowel disease had higher measures of intestinal disease activity than patients with primary sclerosing cholangitis. Despite this, shorter telomere length and telomere aggregates, especially the fusion of 2-5 telomeres, were observed at significantly higher rate in patients with primary sclerosing cholangitis relative to inflammatory bowel disease or healthy controls. Rates of aneuploidy and telomere capture were higher in the two probes in both diseases compared to controls (p<0.001). CONCLUSION Dysfunction of telomeres was demonstrated in primary sclerosing cholangitis patients more than inflammatory bowel disease and healthy controls patients, which attests to genetic instability and immunosenescence. TRIAL REGISTRATION NUMBER NCT02247622.


Journal of Crohns & Colitis | 2013

P358 Tetrahydrocannabinol (THC) induces clinical and biochemical improvement with a steroid sparing effect in active inflammatory bowel disease

Timna Naftali; L. Barlev; G. Gabay; Yehuda Chowers; Iris Dotan; Assaf Stein; M. Bronstein; Fred M. Konikoff

P358 Tetrahydrocannabinol (THC) induces clinical and biochemical improvement with a steroid sparing effect in active inflammatory bowel disease T. Naftali1 *, L. Barlev2, G. Gabay1, Y. Chowers3, I. Dotan4, A. Stein1, M. Bronstein1, F.M. Konikoff1. 1Meir General Hospital, Gastroenterology, Kfar Saba, Israel, 2Tel aviv University, pschology, Tel Aviv, Israel, 3Rambam Health care campus, Gastroenterology, Haifa, Israel, 4Tel Aviv Sorasky Medical center, Gastroenterology, Tel Aviv, Israel


Surgical Endoscopy and Other Interventional Techniques | 2013

Consecutive versus separate sessions of endoscopic ultrasound (EUS) and endoscopic retrograde cholangiopancreatography (ERCP) for symptomatic choledocholithiasis

Fabiana Benjaminov; Assaf Stein; George Lichtman; Itamar Pomeranz; Fred M. Konikoff


Journal of Crohns & Colitis | 2015

Prognosis of primary sclerosing cholangitis in israel is independent of coexisting inflammatory bowel Disease.

Henit Yanai; Shay Matalon; Amir Rosenblatt; Halim Awadie; Tania Berdichevski; Yifat Snir; Uri Kopylov; Lior H. Katz; Assaf Stein; Liat Mlynarsky; Hagit Tulchinsky; Fred M. Konikoff; Shomron Ben Horin; Marius Braun; Ziv Ben-Ari; Yehuda Chowers; Yaacov Baruch; Oren Shibolet; Iris Dotan


Gastroenterology | 2018

Sa1432 - Small and Numerous Gallbladder Stones are Risk Factors for Complicated Common Bile Duct Stones

Fabiana Benjaminov; Yassin Sharif; Assaf Stein; Timna Naftali; Ido Lish; Fred M. Konikoff


Clinics and Research in Hepatology and Gastroenterology | 2018

Risk of metachronous advanced lesions after resection of diminutive and small, non-advanced adenomas

Ido Laish; Ilia Sergeev; Assaf Stein; Timna Naftali; Fred M. Konikoff


Journal of Crohns & Colitis | 2013

P143 Soluble syndecan-1 (CD138) – a novel biomarker in patients with inflammatory bowel disease

D. Yablecovitch; Assaf Stein; Timna Naftali; G. Gabay; I. Laish; Fred M. Konikoff


Gastroenterology | 2013

Mo1321 Prevalence and Disease Expression of Inflammatory Bowel Disease-Comparison Between Arabs and Jews in Israel

Fabiana Benjaminov; Doron Hermoni; Timna Naftali; Ramona Segal; Assaf Stein; Fred M. Konikoff

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Fred M. Konikoff

Tel Aviv Sourasky Medical Center

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Yehuda Chowers

Rambam Health Care Campus

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