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Biomedical subjects

Y Niv

Publications and source records attributed to Y Niv.

At least 19 recordsLinked to original sources
PubMed2007

Switching from tacrolimus to sirolimus halts the appearance of new sebaceous neoplasms in Muir-Torre syndrome.

Little is known about the effects of immunosuppression on patients with hereditary nonpolyposis colorectal cancer (HNPCC). We describe a kidney transplant recipient with unrecognized Muir-Torre syndrome in whom the administration of a tacrolimus-based regimen led to the eruption of multiple sebaceous tumors. The patient was later found to harbor an MSH2 mutation. Switching to a sirolimus-based regimen resulted in arrest of the disease. When the patient was switched back to tacrolimus, new facial lesions rapidly appeared. Switching again to sirolimus resulted again in halting the appearance of new lesions. This finding is in line with the known antiangiogenic activity of sirolimus and reports on the regression of cutaneous Kaposi's sarcoma in kidney transplant recipients switched from another immunosuppressive regimen to sirolimus. Further studies on the potential use of sirolimus for the treatment of de novo tumors in immunosuppressed kidney transplant recipients with HNPCC are warranted.

Adenoma↗
PubMed2006

Can quantification of faecal occult blood predetermine the need for colonoscopy in patients at risk for non-syndromic familial colorectal cancer?

BACKGROUND: Patients at risk for non-syndromic (Lynch or polyposis) familial colorectal neoplasia undergo colonoscopic surveillance at intervals determined by clinically ascertained protocols. The quantitative immunochemical faecal occult blood test for human haemoglobin is specific and sensitive for significant colorectal neoplasia (cancer or advanced adenomatous polyp). AIM: To determine immunochemical faecal occult blood test efficacy for identifying significant neoplasia in at-risk patients undergoing elective colonoscopy. METHODS: We retrospectively identified consecutive at-risk patients who provided three immunochemical faecal occult blood tests before colonoscopy. Quantitative haemoglobin analysis was performed by the OC-MICRO automated instrument using the 100 ng Hb/mL threshold to determine positivity. RESULTS: In 252 at-risk patients undergoing colonoscopy; five had cancer, 14 an advanced adenoma and 46 a non-advanced adenoma. The immunochemical faecal occult blood test was positive in 31 patients (12.3%). Sensitivity, specificity, positive and negative predictive values for cancer were: 100%, 90%, 16% and 100%, and for all significant neoplasia: 74%, 93%, 45% and 98%. With 88% fewer colonoscopies, all colorectal cancers and 74% of all significant neoplasia would have been identified by this one-time immunochemical faecal occult blood test screening. CONCLUSIONS: A sensitive, non-invasive, interval screening test might be useful to predetermine the need for colonoscopy in this at-risk population and minimize unnecessary examinations. This favourable retrospective evaluation will be extended to a prospective study.

Aged↗
PubMed2006

A quantitative immunochemical faecal occult blood test is more efficient for detecting significant colorectal neoplasia than a sensitive guaiac test.

BACKGROUND: The sensitive guaiac faecal occult blood test, Haemoccult SENSA (HOS; Beckman Coulter, Fullerton, CA, USA), is our standard screening test for significant colorectal neoplasia. We evaluated an automatically-developed, quantified human haemoglobin immunochemical faecal test, OC-MICRO (Eiken Chemical Co., Tokyo, Japan), to improve test specificity and so reduce the colonoscopy burden. AIM: To compare guaiac faecal occult blood test and immunochemical faecal test diagnostic efficacy and costs for identifying significant neoplasia. METHODS: Colonoscopies were performed on patients who prepared three daily guaiac faecal occult blood tests with or without immunochemical faecal tests. RESULTS: Total colonoscopy was performed on 151 subjects who prepared both guaiac and immunochemical faecal tests (group 1) and the positive predictive values (PPV) were also compared to those of 162 subjects undergoing colonoscopy for positive guaiac faecal occult blood tests (group 2). In group 1, comparative sensitivity, specificity, and PPVs for significant neoplasia with guaiac faecal occult blood test were 75%, 34%, and 12% (PPV, 18% for group 2) and with immunochemical faecal test were 75%, 94% and 60% (P < 0.01 for specificity). The number of colonoscopy examinations needed to detect a significant neoplasm because of positive faecal occult blood tests was six to eight with HOS and two with OC-MICRO at 21-31% the cost of evaluating a positive guaiac faecal occult blood test. CONCLUSION: An immunochemical faecal test maintains the high sensitivity of guaiac faecal occult blood test, but significantly reduces the colonoscopy burden and screening costs.

Aged↗
PubMed2005

Capsule endoscopy - comparison of two strategies of bowel preparation.

BACKGROUND: Capsule endoscopy can identify lesions of the small bowel that cannot be detected by other techniques. In addition to patient safety, quality of care and cost-efficiency, good preparation is an important factor for good visualization. AIM: To evaluate the efficacy of oral sodium phosphate preparation. METHODS: Forty-six consecutive patients scheduled for capsule endoscopy in two medical centres. The patients treated in Dallas were prepared by 12 h fasting (group A), and those treated in Israel were also asked to drink 45 mL of sodium phosphate with water (group B). An experienced endoscopist, blinded to the method used, graded the quality of preparation according to visual capability, and to relative durations of each grade. RESULTS: The quality of the preparation was poor in 35% of group A compared with 4% of group B (P = 0.023). The mean duration of good preparation with excellent visualization was 122 +/- 110 min in group A and 180 +/- 96 min in group B (P = 0.006). Preparation with sodium phosphate and lower patient weight were significant predictive factors for good visualization. CONCLUSIONS: Bowel preparation offers better visualization than overnight fasting alone and is associated with fewer disturbances by intraluminal turbid fluid.

Adult↗
PubMed2005

13C-urea breath test for success of Helicobacter pylori eradication: study of 5885 Israeli patients.

Helicobacter pylori (Hp) infection is highly prevalent in many countries and may cause gastritis, peptic ulcer disease, gastric cancer, and lymphoma. Successful eradication depends on the specific treatment used, patient compliance, and Hp antibiotic resistance. The primary aim was to characterize groups of patients with one or more failures of Hp eradication treatment. The secondary aim was to evaluate the factors that influence eradication failure. Between April 1, 1998, and December 31, 2001, 5885 patients were studied for the success of Hp eradication with the 13C-urea breath test (13C-UBT): 5442 after one course of treatment (Group I), 380 after two courses (Group II), and 63 after three courses (Group III). The 13C-UBT was positive in 27.8%, 37.4%, and 47.6% of patients in Groups I, II, and III, respectively (P(I-II) = 0.000, P(II-III) = 0.126). A combination of omeprazole, amoxicillin, and clarithromycin (OAC) was used in 31.3%, 27.4%, and 7.9% of Groups I, II, and III, respectively, and a combination of omeprazole, amoxicillin, and metronidazole (OAM) in 15.2%, 28.9%, and 28.6%, respectively. Regimens that contained clarithromycin were used in decreasing order in Groups I, II, and III, and regimens containing metronidazole, bismuth, or tetracycline, in increasing order. The only good prognostic factor for successful eradication was Israeli origin, while European-American and Asian-African origin, recurrence of symptoms, a history of duodenal ulcer, and chronic proton pump inhibitor (PPI) use did not favor successful eradication. Our results suggest that origin, history of peptic disease, and chronic PPI use are predictors of eradication failure.

Adolescent↗
PubMed2004

Masking of 13C urea breath test by proton pump inhibitors is dependent on type of medication: comparison between omeprazole, pantoprazole, lansoprazole and esomeprazole.

BACKGROUND: The need to withhold acid suppression therapy while awaiting urea breath test results is a common clinical problem in symptomatic patients. It is unclear at present if the dose or type of proton pump inhibitor or the type of test meal govern the apparent masking effect of proton pump inhibitors on the urea breath test. AIM: To prospectively evaluate Helicobacter pylori detection rates during treatment with four different proton pump inhibitors, utilizing a high-dose citric acid-based 13C urea breath test. METHODS: Patients positive for Helicobacter pylori by urea breath test were randomized to receive either omeprazole 20 mg/day, pantoprazole 40 mg/day, lansoprazole 30 mg/day or esomeprazole 40 mg/day for 14 days. A repeat breath test was performed on day 14 of treatment. RESULTS: One hundred and seventy-nine patients, mean age 45.8 +/- 16.8, completed the study. Treatment with omeprazole or pantoprazole prior to urea breath test (UBT) was associated with low false negative results, while lansoprazole and esomeprazole caused clinically unacceptable high false negative rates (pantoprazole 2.2% vs. lansoprazole 16.6%, P = 0.02, vs. esomeprazole 13.6%, P = 0.05; omeprazole 4.1% vs. lansoprazole 16.6%, P = 0.05). CONCLUSIONS: Proton pump inhibitor-induced false negative results on high-dose citric acid based urea breath test vary with the type of proton pump inhibitor used. Selection of the appropriate test meal and proton pump inhibitor may allow symptomatic individuals to continue their proton pump inhibitors prior to performing a urea breath test.

2-Pyridinylmethylsulfinylbenzimidazoles↗
PubMed2004

Gallbladder mucin plays a role in gallstone formation.

Mucin is a high-molecular-weight glycoprotein that is synthesized, stored, and secreted by epithelial mucosal cells, especially goblet cells. Mucin proteins are derived from many different genes, termed MUC genes. Several lines of evidence point to a biological role for mucin in cholesterol gallstone formation. Mucin serves as a pronucleating agent in experimental and human gallstone disease, and the hydrophobic binding sites in the polypeptide core of mucin may provide a favorable environment for nucleation of cholesterol monohydrate from supersaturated bile. Mucin hypersecretion is prominent in many animal models of gallstone formation, thus contributing by its pronucleating quality to gallstone formation. According to some research, mucin hypersecretion may also contribute to the formation of brown pigment stones. This may be explained in part by the findings that lipopolysaccharides derived from certain bacteria are effective stimulants of mucin secretion. Aspirin and nonsteroidal anti-inflammatory drugs inhibit gallbladder mucin secretion and prevent gallstone formation in animal models. Expanding our knowledge on mucin research may improve our understanding of the natural history of gallstone formation and enable the development of new treatment strategies.

Journal Article↗
PubMed2004

Capsule endoscopy: role of bowel preparation in successful visualization.

BACKGROUND: Lesions of the small bowel that cannot be detected by other techniques can be indentified by capsule endoscopy. Good preparation before any endoscopic procedure is the most important factor for patient safety, quality of care and cost effectiveness. This should also apply to capsule endoscopy. The aim of this study was to evaluate the quality and efficacy of preparation with oral sodium phosphate for capsule endoscopy. METHODS: A retrospective cohort study design was used. The study sample consisted of 32 consecutive patients scheduled for capsule endoscopy in two periods; the first 10 patients were prepared with overnight fasting only, and the next 22 with oral sodium phosphate. An experienced endoscopist and gastroenterology nurse, who were blinded to the method used, graded the quality of preparation. RESULTS: Small-bowel cleansing was significantly better in patients given sodium phosphate. Five patients (50%) received a poor preparation rating in the first period compared with only 1 (4.5%) of the 22 patients given oral sodium phosphate (P = 0.01). Intraluminal fluid was noted in 9 patients (90%) in the first group after a mean of 53 +/- 60 min, and in 17 patients (77%) in the second group after a mean of 158 +/- 71 min (P < 0.001). The proportion of non-ideal preparation was significantly higher in group 1 than in group 2, significant visualization disturbances being more prevalent in the first period. CONCLUSIONS: Bowel preparation with sodium phosphate before capsule endoscopy offers better visualization than overnight fasting alone and induces fewer disturbances by intraluminal turbid fluid.

Administration, Oral↗
PubMed2004

Prevalence of Helicobacter pylori infection in health-care personnel of primary care and gastroenterology clinics.

BACKGROUND & AIMS: Helicobacter pylori (Hp) infection clusters within families, is usually acquired early in life, and is strongly associated with lower socioeconomic status during childhood. Transmission in adulthood is relatively rare, and reports on the prevalence of Hp infection among health personnel, especially endoscopists, are controversial. The present prospective study evaluated the prevalence of Hp infection in health-care workers in primary-care clinics and in gastroenterology units. METHODS: Health care personnel from gastrointestinal units (n = 191) and primary care-clinics (n = 98) of the Clalit Health Services (CHS) in Israel underwent the carbon 13 breath test (13C-UBT) and completed a 21-item demographic and socioeconomic questionnaire. The control group consisted of 4633 symptomatic patients with no evidence of previous Hp infection. RESULTS: The 13C-UBT was positive in 108 gastrointestinal unit personnel (73%) and 70 primary-care workers (71%); both rates were statistically higher significantly than the 53% positivity in the controls. Comparison of the 13C-UBT Hp-positive and Hp-negative health-care personnel yielded a significantly higher index of crowded living conditions in the Hp-positive group. In the gastrointestinal unit workers, Hp positivity was also associated with several years in practice, and in the primary-care workers, with Sephardic (Asian and African origin) versus Ashkenazi (Europe and American) origin. Profession (physician, nurse, technician, secretary, or maintenance worker), history of duodenal ulcer, smoking, marital status, and blood group did not have predictive value for Hp colonization. CONCLUSIONS: The prevalence of Hp infection in Israel is higher in health-care staff of primary-care clinics and gastrointestinal units than in the general population. This may be related to socioeconomic facts and professional hazard. Further studies are needed to clarify this issue.

Adult↗
PubMed2003

Colorectal cancer in the south of Israel; comparison of the clinical characteristics and survival between two periods, 1981-2 and 1986-7.

BACKGROUND: Colorectal cancer has the highest incidence of all malignant tumours in men and women in Israel. The public was introduced to the concept of screening in the early 1980s, and full programs began in 1983. OBJECTIVES: The study compares patients with colorectal cancer (CRC) who were diagnosed before screening and five years later, for stage differences and survival. METHODS: All patients with CRC who were diagnosed from 1981 to 1982 (period I) and 1986-87 (period II) at Soroka Medical Centre and who were residents of the Negev area were eligible for the study. Data were collected retrospectively from the Israel Cancer Registry and patient files and endoscopic, histological and surgical reports from the Departments of Pathology, Gastroenterology, Oncology and Surgery at Soroka Medical Centre. RESULTS: The study groups included 207 patients with CRC, 85-from period I and 122-from period II. The mean annual incidence of CRC for these 2 periods was 18 and 24.8 cases per 100, 000, respectively, for an increase of 37% (P < 0.001). Five-year-survival in period I was 53.3% and in period II, 39.6% (P = 0.025). Survival did not differ by origin or gender. Dukes' stage, well and moderately differentiated tumours, and left-sided tumours were associated with better prognosis (P = 0.03). Forty-two percent of the cases were less than 64-year-old-at diagnosis, compared with 27% of 2069 Israeli patients in whom CRC was diagnosed in 1991 (P < 0.001). CONCLUSIONS: Before a nation wide decision is made with regard to public screening for CRC with fecal occult blood tests or sigmoidoscopy, the available data should be thoroughly evaluated, and further in-depth investigations performed to determine trends in diagnosis and prognosis.

Adenocarcinoma↗
PubMed2002

Protective effect of faecal occult blood test screening for colorectal cancer: worse prognosis for screening refusers.

BACKGROUND AND AIMS: Screening for colorectal cancer (CRC) by faecal occult blood testing (FOBT) decreases CRC mortality by 15-33%. Compliance remains an obstacle to maximising the benefit of FOBT screening. We tested the hypothesis that individuals offered FOBT screening but refused would have an increased incidence and worse prognosis for CRC compared with those tested and with controls. METHODS: Annual screening was offered to 3548 average risk individuals, > or = 40 years of age, from a highly stable population. A total of 2538 agreed to testing (group 1) and 1010 (28%) refused (group 2). Another 1376 individuals were never offered the test and served as controls (group 3). The groups were followed for 11 years: a three year screening period (1985-1987) and an eight year follow up period at the end of the screening programme (1988-1995). Incidence, stage, and mortality were compared. Characterisation of refusers was completed in 188 and 130 subjects of groups 1 and 2, respectively. RESULTS: In the screening phase, mortality from CRC was significantly lower in group 1 than in groups 2 and 3. The cumulative incidence of CRC in the eight year follow up period was 21 (0.88%), 23 (2.28%), and 13 (0.94%) in groups 1, 2, and 3, respectively. This shows a reduction of 61.4% in group 1 compared with group 2 (relative risk 0.28 (95% confidence interval (CI) 0.19-0.32)) (p<0.001) and 6.4% compared with group 3 (relative risk 0.93 (95% CI 0.93-1.00)) (NS). During follow up, group 1 subjects also demonstrated a decrease in advanced Dukes' stage and mortality rate by 80% and 64%, and 79% and 62%, compared with groups 2 and 3, respectively. Refusers were more likely to be male, of Asian-African descent, and more likely to smoke, consume more coffee, and less tea or dairy foods. CONCLUSIONS: When accepted, FOBT may protect against CRC for prolonged periods. Individuals who refuse FOBT have a significantly higher CRC incidence and mortality rates than those who accept testing.

Adult↗