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Dive into the research topics where Tsachi Tsadok Perets is active.

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Featured researches published by Tsachi Tsadok Perets.


Journal of Clinical Gastroenterology | 2013

Mucin function in inflammatory bowel disease: an update.

Doron Boltin; Tsachi Tsadok Perets; Alex Vilkin; Yaron Niv

MUC2 is the primary component of the mucin barrier that separates the intestinal microbiota and the intestinal epithelium. This mucous barrier is affected by both luminal/microbial factors and host/immune factors, both of which have genetic and environmental determinants. The complex interactions between these players in health and disease states are not fully understood. Inflammatory bowel disease (IBD) has both genetic and environmental etiologies that lead to the breakdown of the epithelial barrier. In this review, we explore the up-to-date evidence that implicates mucin in the pathogenesis of IBD. In IBD, quantitative changes in mucin secretion occur, as well as structural changes in mucin’s glycoprotein core and the sulfation and sialylation of mucin’s oligosaccharide residues. These changes are associated with a diminished functionality of the mucous barrier. We identify the various genetic mutations associated with these changes and outline the animal models that have enhanced the current understanding of the genetic basis for IBD. Further study is needed to better characterize the immune and genetic influences on mucin expression and secretion and role of endoplasmic reticulum stress and a defective unfolded protein response in mediating these changes.


Journal of Clinical Microbiology | 2015

Trends in Secondary Antibiotic Resistance of Helicobacter pylori from 2007 to 2014: Has the Tide Turned?

Doron Boltin; Haim Ben-Zvi; Tsachi Tsadok Perets; Zvi Kamenetsky; Zmira Samra; Ram Dickman; Yaron Niv

ABSTRACT The current guidelines recommend culture and antibiotic susceptibility testing of Helicobacter pylori following two failed eradication attempts. Where testing is unavailable, epidemiological data for secondary H. pylori resistance are essential to allow for the rational use of antibiotics. The aim of this study was to describe the temporal changes in antibiotic resistance among adults previously treated for H. pylori infections and to identify predictors of resistance. Between 2007 and 2014, consecutive patients undergoing gastroscopy with H. pylori culture and susceptibility testing at our institution following at least two treatment failures were retrospectively identified. Antibiotic susceptibilities were recorded and linked to the demographic data. A total of 1,042 patients were identified, including 739 (70.9%) males, aged 39.3 ± 18.9 years. Resistance to clarithromycin, metronidazole, and levofloxacin was found in 57.2%, 64.4%, and 5.1% of isolates, respectively. Dual resistance to clarithromycin and metronidazole was seen in 39.9%. Over the study period, clarithromycin resistance increased annually in a linear manner (odds ratio [OR], 1.09; 95% confidence interval [CI], 1.03 to 1.14; P < 0.01), levofloxacin resistance decreased annually (OR, 0.78; 95% CI, 0.61 to 0.92; P < 0.01), and metronidazole resistance was nonlinear. Age was an independent predictor of resistance to all antibiotics. Time elapsed predicted resistance for clarithromycin and levofloxacin and dual resistance for clarithromycin-metronidazole. Secondary resistance of H. pylori to clarithromycin and metronidazole remains high. The low secondary resistance to levofloxacin makes it an attractive treatment option in our region for patients following two failed eradication attempts.


Annals of Clinical Microbiology and Antimicrobials | 2014

Rifaximin for small intestinal bacterial overgrowth in patients without irritable bowel syndrome

Doron Boltin; Tsachi Tsadok Perets; Einav Shporn; Shoshana Aizic; Sigal Levy; Yaron Niv; Ram Dickman

BackgroundRifaximin is a minimally absorbed antibiotic with high luminal activity, used to treat various gastrointestinal diseases. Although rifaximin has been proposed as first line treatment for small intestinal bacterial overgrowth (SIBO), few data are available regarding its efficacy in non-IBS subjects. We aimed to assess the ability of rifaximin to normalize lactulose-H2 breath tests in non-IBS subjects with symptoms suggestive of SIBO.Materials and methodsConsecutive non-IBS patients presenting with bloating and flatulence were prospectively recruited and submitted to lactulose-H2 breath testing (LBT). Patients who had a positive result were offered rifaximin 1200 mg daily for 10 days. Breath testing was repeated two weeks after treatment completion in all patients in order to assess for response.ResultsA total of 19 patients with a positive result received rifaximin and repeated the breath test (7 (36.8%) males, age 56.5 ± 17.6 years). The mean peak hydrogen excretion was 13.7 ± 2.8 and 10.3 ± 7.3 ppm at baseline and following rifaximin treatment, respectively (t = 1.98, p = 0.06). LBT normalized in 8/19 (42.1%) subjects. No patients reported symptom resolution. No adverse events were reported.DiscussionStrengths include the studys prospective design. Limitations include the small sample size and open label design.ConclusionRifaximin was not effective in normalizing LBT in our cohort of non-IBS subjects with symptoms suggestive of SIBO.


Journal of Clinical Microbiology | 2009

High Frequency and Diversity of Rearrangements in Polyomavirus BK Noncoding Regulatory Regions Cloned from Urine and Plasma of Israeli Renal Transplant Patients and Evidence for a New Genetic Subtype

Tsachi Tsadok Perets; Ilana Silberstein; Jana Rubinov; Ronit Sarid; Ella Mendelson; Lester Shulman

ABSTRACT Polyomavirus BK (BKV) establishes latent infection in various human tissues, including the kidney. Reactivation following renal transplantation (RT) may cause BKV-associated nephropathy, leading to graft loss. BKV reactivation is often associated with extensive rearrangements in the BKV noncoding regulatory region (NCRR). We explored the formation and predominance of the rearrangements versus the diversity of the rearrangements by cloning and characterizing PCR-amplified NCRR sequences from six Israeli RT patients. We found a high frequency and a high degree of diversity of rearrangements: NCRRs that contained major rearrangements (mrNCRRs), including large insertions and deletions, were detected in 0 to 100% of the clones from individual samples (mean, 50% and 67% in plasma and urine, respectively). In addition, we found a high frequency of mrNCRRs that contained single-nucleotide variations (snvNCRRs) among identical mrNCRRs and archetype clones. mrNCRRs were present in plasma and in concomitantly collected urine samples, but for each patient, only a subset of the mrNCRRs and snvNCRRs were present in both compartments at the same time and/or in subsequent samples from the same compartment. Some mrNCRRs were observed over several months, indicating the continuous replication of the viral genomes carrying them. Phylogenetic analysis based on the snvNCRR in the archetype clones grouped isolates from four of the patients into a new subgroup of genotype IV. Genotypes Ib-1 and Ib-2 were also found. Isolates from two patients had NCRRs from two genotypes, one concurrently with a RT and one after a second RT. Our study prompts further investigation of the functional consequences of NCRR rearrangements to assess their biological significance and their putative role in disease progression and prognosis.


International Journal of Infectious Diseases | 2014

Helicobacter pylori infection amongst Arab Israeli women with hyperemesis gravidarum—a prospective, controlled study

Doron Boltin; Tsachi Tsadok Perets; Sami Abu Elheiga; Asher Sharony; Yaron Niv; Hussein Shamaly; Ram Dickman

OBJECTIVE Helicobacter pylori has been associated with hyperemesis gravidarum in some geographical regions. The prevalence of H. pylori in Arab Israeli women in the Upper Galilee and its association with hyperemesis gravidarum has not been studied previously. We aimed to examine if hyperemesis gravidarum is associated with H. pylori in this population. METHODS Subjects with hyperemesis gravidarum carrying a singleton fetus were recruited prospectively. Women with an uncomplicated pregnancy served as controls. All patients underwent (13)C-urea breath testing to assess for H. pylori infection. RESULTS A total of 72 subjects, including 24 patients with hyperemesis gravidarum and 48 controls, aged 28.8±5.3 years, were included. H. pylori infection was identified in 75.0% (18/24) of cases and 60.4% (29/48) of controls (p=not significant). H. pylori infection did not correlate with age, fetal sex, or the number of previous pregnancies (p=not significant). CONCLUSION H. pylori does not seem to increase the likelihood of hyperemesis gravidarum in Arab Israeli women. However, given the high background prevalence of H. pylori in this population, a larger study is required to corroborate these findings. (MOH20110066).


American Journal of Hematology | 2014

Lactose intolerance is not the cause of gastrointestinal adverse effects in beta thalassemia patients treated with deferasirox

Idit Pazgal; Marius Brown; Tsachi Tsadok Perets; Yaron Niv; Eliezer A. Rachmilewitz; Pinhas Stark

patients were able to proceed to HSCT. We also used sorafenib in patients whose leukemia with FLT3-ITD relapsed after HSCT and observed meaningful clinical outcomes in this extremely poor prognostic situation. Metzelder et al. demonstrated high activity of sorafenib in FLT3-ITD AML post-HSCT possibly secondary to synergizing allo-immune effects leading to sustained regression in this specific population [9]. We also used sorafenib as maintenance therapy preand post-HSCT with durable complete response. Sorafenib was tolerated well with occasional dose reductions due to adverse events including elevated liver enzymes. Further prospective clinical trials are needed to evaluate the use of sorafenib in FLT3-ITD AML as single and/or adjunctive therapy.


European Journal of Gastroenterology & Hepatology | 2018

Helicobacter pylori infection is positively associated with an increased BMI, irrespective of socioeconomic status and other confounders: a cohort study

Mohamad Suki; Yaara Leibovici Weissman; Doron Boltin; David Itskoviz; Tsachi Tsadok Perets; Doron Comaneshter; Arnon D. Cohen; Yaron Niv; Iris Dotan; Haim Leibovitzh; Zohar Levi

Background Data on the association of Helicobacter pylori infection and BMI are conflicting. The fact that both H. pylori infection and BMI are associated with low socioeconomic status (SES) makes this relationship difficult to characterize. Materials and methods We aimed to evaluate the association between BMI and H. pylori infection after adjusting for multiple covariates. We analyzed a cohort of 235 107 individuals aged 18 years or older, who performed a 13C urease breath test (13C-UBT), from 2007 to 2014. Data on BMI, age, sex, SES, ethnicity, and medications were extracted from a nationwide population-based database. BMIs were classified according to the WHO recommendations: underweight (<18.5 kg/m2), normal weight (18.5–24.9 kg/m2), overweight (25–29.9 kg/m2), obese class I (30–34.9 kg/m2), and obese class II or more (>35 kg/m2). Study results The positivity rate for H. pylori among underweight, normal weight, overweight, and obese class I and class II or more was 55.6, 58.5, 63.0, 64.5, and 65.5%, respectively (P<0.001, Plinear trend 0.007). The association between BMI and H. pylori infection was significant across all SES, sex, ethnicity, and age categories. After adjusting for age, sex, ethnicity, and SES, being overweight and obese class I and class II or more were associated significantly with H. pylori positivity: odds ratio 1.13 [95% confidence interval (CI): 1.11–1.15], 1.14 (95% CI: 1.11–1.17), and 1.15 (95% CI: 1.11–1.19), respectively, P value less than 0.001 for all. Conclusion Among individuals who were referred to a 13C-UBT by primary care physician, after adjusting for multiple covariates including SES, we found a positive association between H. pylori infection and an increased BMI.


Digestion | 2018

Temporal Trends in Helicobacter pylori Eradication Success in a Test-and-Treat Population

Doron Boltin; Hemda Schmilovitz-Weiss; Rachel Gingold-Belfer; Haim Leibovitzh; Yifat Snir; Tsachi Tsadok Perets; Ram Dickman; Zohar Levi; Yaron Niv

Background/Aims: Although the efficacy of first-line treatment for Helicobacter pylori infection should aim to be > 90%, it is unclear whether this target has been achieved in Israel. We aimed to determine the success rate of treatment for H. pylori and to describe temporal changes in our region. Methods: Adult patients who underwent a first-time C13-urea breath test (C13-UBT) at Clalit Health Services between January 1, 2010 and December 31, 2015 were included. In order to isolate a naïve “test-and-treat” population who were unlikely to have undergone an initial endoscopy-based H. pylori test, we excluded patients ≥45 years and those with any previous C13-UBT. Results: A total of 94,590 subjects (36.1% male, age 28.5 ± 6.0) who underwent at least one C13-UBT during the study period were included. C13-UBT was positive in 48,509 (51.3%) subjects. A confirmatory post-treatment C13-UBT was performed in 37.8, 44.1, 46.6, and 45.9% following 1st, 2nd, 3rd, and 4th-line treatment respectively. Eradication was successful in 65.4% following first-line treatment, and eradication success improved during the study period (59.2, 63.3, 65.7, 66.0, 69.0, and 73.1% in 2010, 2011, 2012, 2013, 2014, and 2015 respectively; OR 1.11; 95% CI 1.09–1.13; p < 0.0001). Eradication was successful in 44.7% following second-line treatment, although eradication success did not significantly improve during the study period (OR 1.05; 95% CI 0.99–1.10; p = 0.09). Conclusions: Despite the increasing success of first-line treatment for H. pylori infection over the study period, eradication rates remain suboptimal. Initiatives to implement the Toronto and Maastricht Consensus Reports should be advanced.


Digestion | 2015

Appropriateness of Repeating Helicobacter pylori Culture and Susceptibility Testing Following Failure of Individualized Antibiotic Therapy.

Doron Boltin; Haim Ben-Zvi; Tsachi Tsadok Perets; Rachel Gingold-Belfer; Ram Dickman; Yaron Niv

Background: Current guidelines recommend direct Helicobacter pylori culture and antibiotic susceptibility testing following 2 failed eradication attempts. If this process is followed and yet subsequent treatment is unsuccessful, it is unclear whether susceptibility testing should be repeated. This is the first study to examine the appropriateness of repeated H. pylori culture and susceptibility testing following failure of individualized treatment. Methods: Between 2007 and 2014, consecutive patients who underwent at least 2 upper gastrointestinal endoscopies with H. pylori culture and susceptibility testing at our institution following several treatment failures were retrospectively identified. Antibiotic susceptibility was recorded and linked to demographic data. Results: A total of 68 cultures from 34 patients were included (12 (35.3%) men, 41.4 ± 16.6 years), and 20 (58.8%) cultures had a different antibiotic susceptibility profile on repeat testing (8 (23.5%) with new susceptibility and 13 (38.2%) with new resistance). Acquired resistance to clarithromycin, levofloxacin and metronidazole was observed in 9 (26.5%), 2 (5.9%) and 10 (29.4%) cultures, respectively. Subjects with resistance to ≤1 antibiotic at baseline were more likely to develop resistance to at least 1 antibiotic on subsequent culture, compared to subjects with resistance to ≥2 antibiotics at baseline (13 (100%) vs. 5 (23.8%), p < 0.01). Conclusion: Repeating H. pylori culture and susceptibility testing usually yields new antimicrobial susceptibility data. However, the clinical usefulness of this approach remains unclear.


Gastroenterology | 2014

Mo1975 A Diagnostic Approach to Patients With Suspected Lactose Malabsorption

Tsachi Tsadok Perets; Einav Shporn; Shoshana Aizic; Yelena Kelner; Sigal Levy; Yaron Niv; Ram Dickman

Background The lactose breath test (LBT) is the standard technique for diagnosis of lactose malabsorption. However, it is time-consuming, strenuous for the patient and has been reported to have low sensitivity. The lactose intolerance quick test (LIQT) measures lactase activity in duodenal biopsies and may be performed as part of upper gastrointestinal endoscopy.

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Arnon D. Cohen

Ben-Gurion University of the Negev

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