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Yaron Niv

Publications and source records attributed to Yaron Niv.

At least 19 recordsLinked to original sources
PubMed2006

Susceptibility-guided vs. empiric retreatment of Helicobacter pylori infection after treatment failure.

Successful eradication of Helicobacter pylori after failure of standard triple therapy is difficult because of the higher resistance to metronidazole and clarithromycin. We evaluated the efficacy of susceptibility-guided vs. empiric retreatment for H. pylori after at least one treatment failure and determined the prevalence of posttreatment antibiotic resistance. Forty-nine patients in whom at least one treatment regimen for H. pylori eradication had failed underwent gastric biopsy and culture and were retreated according to the in vitro susceptibility results. Findings were compared with those for 49 control patients referred to our center for a (13)C-urea breath test. H. pylori eradication was assessed by urea breath test at least 6 weeks after retreatment in both groups. Susceptibility-guided retreatment was associated with better eradication rates than empiric treatment. The difference remained significant in stratified and multivariate analysis. Susceptibility-guided retreatment appears to be significantly more effective than empiric retreatment in eradicating H. pylori after at least one previous treatment failure.

Anti-Bacterial Agents↗
PubMed2006

Incidence and management of colonoscopic perforations: 8 years' experience.

AIM: To review the experience of a major medical teaching center with diagnostic and therapeutic colonoscopies and to assess the incidence and management of related colonic perforations. METHODS: All colonoscopies performed between January 1994 and December 2001 were studied. Data on patients, colonoscopic reports and procedure-related complications were collected from the departmental computerized database. The medical records of the patients with post procedural colonic perforation were reviewed. RESULTS: A total of 120067 colonoscopies were performed during the 8 years of the study. Seven colonoscopic perforations (4 females, 3 males) were diagnosed (0.058%). Five occurred during diagnostic and two during therapeutic colonoscopy. Six were suspected during or immediately after colonoscopy. All except one had signs of diffuse tenderness and underwent immediate operation with primary repair done in 4 patients. No deaths were reported. CONCLUSION: Perforation rate during colonoscopy is low. Nevertheless, it is a serious complication and its early recognition and treatment are essential to optimize outcome. In patients with diffuse peritonitis early operative intervention makes primary repair a safe option.

Adult↗
PubMed2006

Evaluation of a desk top instrument for the automated development and immunochemical quantification of fecal occult blood.

BACKGROUND: The guaiac fecal occult blood test (FOBT) for colorectal cancer (CRC) screening is user dependent and not specific for human hemoglobin (Hb). The automated-developed, quantitative, immunochemical human Hb FOBT (I-FOBT) is specific, allows for quality control and selection of a suitable Hb level, with optimal sensitivity and specificity, for colonoscopy. MATERIAL/METHODS: We evaluated a desktop instrument, OC-MICRO (Eiken, Japan), which automatically develops and quantifies 50 fecal tests/hr for Hb; for ease of use, test reproducibility and stability and intra-patient daily I-FOBT variation; clinical evaluation included sensitivity and specificity for neoplasia in patients undergoing colonoscopy. RESULTS: Five hundred patients prepared 3 fecal tests which were quantified for Hb, I-FOBT samples were: (1) repeatedly re-examined; (2) stored at 4 degrees C or 20 degrees C or 28 degrees C and re-examined; (3) I-FOBT levels correlated with colonoscopic findings. Five I-FOBTs re-examined 6 times had no significant changes; 30 tests stored > or = 21 days had a decay/day of: 0.3%+/-0.4 at 4 degrees C (NS), 2.2%+/-1.7 at 20 degrees C (NS) and 3.7%+/-1.8 at 28 degrees C (P<0.05). Receiver operator characteristic curve analysis showed that at the 100 ng Hb/mL I-FOBT level 76.5% of CRCs and advanced adenomas were detected with a specificity of 95.3%. CONCLUSIONS: The instrument provided reproducible results and refrigerated I-FOBT samples were stable 21 days. An I-FOBT level can be chosen to provide optimal sensitivity and specificity for significant neoplasia.

Colonoscopy↗
PubMed2006

In vitro activity of levofloxacin against Helicobacter pylori isolates from patients after treatment failure.

We tested the in vitro activity of levofloxacin (LEV), amoxicillin (AMP), clarithromycin (CLA), metronidazole (MET), and tetracycline (TET) against 70 clinical isolates of Helicobacter pylori recovered from 70 dyspeptic patients. All patients had previously failed 2 treatment regimens: first-line triple therapy with omeprazole, AMP, and CLA, and second-line quadruple therapy with omeprazole, MET, TET, and bismuth. Resistance to CLA, MET, and LEV was found in 65.7%, 57.1%, and 18.6% of isolates, respectively. Resistance to both CLA and MET was found in 32.8%, and to CLA, MET, and LEV in 12.8%. Only 4 of the isolates were resistant to both CLA and LEV, and none was resistant to LEV alone or to MET and LEV. Physicians should consider triple therapy with omeprazole, LEV, and AMP in patients unsuccessfully treated with first- and second-line regimens.

Anti-Bacterial Agents↗
PubMed2006

Patient retention in a clinical trial: a lesson from the rofecoxib (VIOXX) study.

A high retention rate of patients and control subjects is an important criterion for the credibility and accuracy of prospective, randomized, controlled clinical trials. Retention and adherence depend on a combination of patient-, physician- and coordinator-related factors, and these need to be carefully evaluated to ensure success. The aim of the study was to evaluate predictive factors for patient retention in a clinical trial. Questionnaires containing items on demographic and clinical data and specific questions related to patient motivation were distributed to 31 patients participating in a clinical study comparing rofecoxib (Vioxx) and placebo for the prevention of colonic polyp recurrence. Adherence of the group with the rofecoxib study and the questionnaire was 100%. The sample included 24 men (77%) and 7 women of mean age 66+/-9 years; 90% were married, 42% were employed. A family history of colorectal cancer (CRC) was reported by 29%. The main reasons for adherence reported by the patients (on an analog scale of 0-10) were 24-hour availability of a nurse (9.2+/-1.9), the chance to prevent CRC (9.1+/-1.9), and participation in a multicenter study (9.1+/-2.2). The least important factor was support of the family physician (5.8+/-4.1). In conclusion, retention in a clinical trial mainly depends on the subject of the trial and the scientific/professional setting where it takes place, and less on the support of the family physician.

Aged↗
PubMed2006

Relationship between nutritional habits adopted by ulcerative colitis relevant to cancer development patients at clinical remission stages and molecular-genetic parameters.

UC (ulcerative colitis) patients have an increased risk of developing colorectal cancer compared with the normal population. The cause underlying this higher risk is not fully defined but includes nutritional and environmental factors concomitant with genetic alterations. We aimed to evaluate genetic stability in the colonic tissue of UC patients in clinical remission compared with the healthy population, and to establish a possible correlation between nutritional habits and these molecular assessments. UC patients (n 42) and healthy controls (n 37) participated in the study. All participants were histopathologically and medically diagnosed. Participants completed five separate 7 d dietary records, food-frequency questionnaires and validated 24 h recalls for nutritional assessment. The extent of chromosome 17 loss and the calculated chromosome index was determined in colon tissue biopsies by fluorescence in situ hybridisation. Correlations between the molecular and nutritional assessments were performed using Pearson's correlation coefficients. Significant differences in the nutritional intake of total fat (65 (SD 15) v. 89 (SD 25) g), cholesterol (330 (SD 168) v. 464 (SD 177) mg), dietary fibre (32 (SD 4.7) v. 9 (SD 4) g), vitamin A (1009 (SD 209) v. 506 (SD 204) microg), vitamin C (308 (SD 108) v. 72 (SD 53) mg) and folic acid (412 (SD 89 microg) v. 187 (SD 107)) were recorded for UC patients compared with controls. Significant correlations were found for the consumption of different food groups and the chromosome index for chromosome 17. The results of our study suggest that the nutritional habits adopted by UC patients during clinical remission may affect key cellular components of the colonic tissue, inducing a high degree of aneuploidy and genetic instability, and probably affecting the development of colon cancer.

Adult↗
PubMed2006

Survey of primary physicians' knowledge of colorectal cancer screening.

OBJECTIVE: Colorectal cancer (CRC) is the most common of the gastrointestinal cancers in Israel. The low rate of patient compliance to a recent CRC screening program of Clalit Health Services, a major health management organization in Israel, prompted the present survey of primary care physicians' knowledge and practices regarding CRC screening. METHODS: A 23-item questionnaire, formulated according to the policy of the Israel Ministry of Health and the recommendations of the American Gastroenterological Association, was distributed to 150 primary physicians of Clalit Health Services. The relative ratio of correct to incorrect answers was calculated for every question and by professional group. RESULTS: The response rate was 89%. Total score (out of a maximum 23) was 20.68 for family physicians (experts in family medicine), 17.79 for experts in other fields, and 17.82 for general practitioners (average, 0.90, 0.77, and 0.77, respectively). The score for the family physicians was significantly higher than for the other two groups (P=0.0070). Clustering items by specific issues yielded significantly better scores for the family physicians in four areas: screening (P=0.0164), appropriate test for high-risk population in Israel (P=0.0012), definition of average-risk population (P=0.0012), and CRC symptoms (P=0.0108). A low level of knowledge on the definition of the high-risk population was noted in all three groups. CONCLUSIONS: Experts in family medicine in Israel have significantly greater knowledge of most issues of CRC than primary care experts in other fields and general practitioners, although all three groups lack knowledge on the definition of the high-risk population. Continuing physician education should focus on these areas.

Chi-Square Distribution↗
PubMed2005

BAT monoclonal antibody immunotherapy of human metastatic colorectal carcinoma in mice.

BAT monoclonal antibody exhibited anti-tumor activity mediated by T and NK cells. We have evaluated the efficacy of murine and humanized BAT for the treatment of human colorectal carcinoma liver metastases in nude mice. HM7, a human colorectal carcinoma was injected into the spleen to colonize the liver. A single intravenous administration of both BAT antibodies significantly reduced the number of metastases and liver weights. Histological examinations demonstrated lymphocyte accumulation near remnant tumors and in tumor-free tissues of BAT treated mice. The efficacy of humanized BAT in the regression of hepatic metastases in human colorectal carcinoma has potential clinical use.

Animals↗
PubMed2005

BAT mAb induces lymphopoiesis in nude mice.

The athymic nude mouse provides a powerful tool in the study of human tumors, as it enables growth of human tumors due to deficiencies in T cell functions. However, deficiencies in T cell functions might limit research on efficacy of immune modulators in cancer immunotherapy. BAT mAb mediates its anti-cancer activity through modulation of the immune system that involves both NK and T cells. We analyzed lymphocyte populations in blood 5 and 14 days following the injection of BAT antibody alone or following engraftment of human colon carcinoma cells. Our results demonstrate that BAT injection induced lymphopoiesis in the nude mouse. Percentage of CD3 cells increased up to 24%, CD4 cells up to 20% but no increase was found in CD8 T cells in BAT-injected nude mice. Injection of BAT 12 days post-tumor engraftment propagated CD3, CD4 and CD8 cells seen in the blood 5 days later but not seen in the blood 14 days post-BAT injection. It is possible that this decrease is associated with migration of the lymphocytes from the blood to the tumor sites in the livers. The percentage of CD56-positive NK cells increased (up to 18%) by BAT administration alone or post-tumor injection. The presence of tumors alone did not induce lymphopoiesis in the nude mice. Propagation and lymphopoiesis by BAT mAb might have future clinical implications.

Animals↗
PubMed2005

Endoscopy in asymptomatic minidose aspirin consumers.

Aspirin is widely used for its antiplatelet activity, but it harbors a risk of severe adverse gastrointestinal effects, such as bleeding and perforation, especially in elderly people. Our aim to assess the prevalence of upper gastrointestinal lesions and the effect of aspirin on the gastrointestinal mucosa in asymptomatic subjects taking minidose aspirin (100 to 325 mg per day) for more than 3 months. A prospective, open design was used. Patients attending the ophthalmology and cardiology outpatient clinics who had a medical history of more than 3 months of regular aspirin consumption were referred for esophagogastroduodenoscopy (EGD). Of the 90 patients referred for EGD, 44 were symptomatic (epigastric pain or dyspepsia) and were excluded from the study. The 46 asymptomatic patients included 22 men and 24 women of mean age 70 +/- 10 years (range, 36 to 87 years); 32% were current or former smokers. Mean daily aspirin dose was 129.34 +/- 76.61 mg. Only 24% were taking a gastroprotective agent. EGD revealed ulcer or erosions in 47.83% of the patients: erosive gastroduodenitis in 13 patients, gastric ulcer in 14, duodenal ulcer in 2, and gastric and duodenal ulcers in 2. Urease test for Helicobacter pylori infection was positive in 26%. Univariate and multivariate analysis revealed no factor other than aspirin predictive of a positive endoscopy. Minidose aspirin treatment is associated with a high prevalence of ulcerations of the stomach and duodenum.

Aged↗
PubMed2005

Comparison of proton pump inhibitor-based triple therapy with losec and the generic drug, Omepradex, for efficacy of Helicobacter pylori eradication.

Triple therapy with a proton pump inhibitor (PPI), amoxicillin, and clarithromycin is widely accepted in Israel for Helicobacter pylori eradication. Recently, a generic drug for omeprazole was introduced to the market, but its efficacy as a PPI was questioned. The aim of the study was to compare eradication efficacy of triple therapy-based regimens with Losec (Astra-Zeneca, Sweden) and the generic form, Omepradex (Dexxon, Israel). People belonging to Clalit Health Services (CHS), the biggest health insurance provider in Israel, and receiving omeprazole (Losec or Omepradex) for 7 days (assumed to be Helicobacter pylori eradication purposes), between 1.1.2001 and 31.12.2001, were retrieved from the CHS central computer. Of 450 patients (287 in the Losec group and 163 in the Omepradex group), 97 (21.6%) underwent 13C-urea breath test (13CUBT) for validation of Helicobacter pylori successful eradication and participated in the study. They were all treated with triple therapy with omeprazole, amoxicillin, and clarithromycin, and were stratified according to the PPI used: Group A, Losec; and Group B, Omepradex. Positivity of 13CUBT was computed. Sixty-one (21.25%) and 36 (22.08%) patients in Groups A and B, respectively, underwent 13 CUBT for validation of successful Helicobacter pylori eradication (NS). In Group A 41 of 61 patients (67.21%) had a negative 13CUBT, in comparison with 26 of 36 (72.22%) in Group B (NS). Using logistic regression analysis all confounding factors were found to be noncontributory to the discrimination between negative (successful eradication) and positive (failed eradication) 13CUBT. There is no statistically significant difference between Losec and the generic drug Omepradex as part of a PPI-based triple therapy for eradication efficacy of Helicobacter pylori.

Adult↗
PubMed2005

Need for guidelines in gastroenterology for the general practitioner.

General practitioners base their clinical strategy on evidence-based medicine and experience. When prospective randomized controlled studies have not provided an answer to a specific clinical question, or when common practice in a certain area is not well established, guidelines formulated by specialists with in-depth knowledge of the field are needed. Studies have shown that gastroenterology guidelines have improved the approach to Helicobacter pylori infection and the management of gastroesophageal reflux disease. Failure to use these guidelines by general practitioners can lead to diagnostic inconsistencies and faulty patient care. This is particularly important in Israel, where the heterogeneous patient and physician populations are characterized by differences in the interpretation of symptoms, disease prevalence, and education.

Family Practice↗
PubMed2005

Effectiveness of omeprazole- versus lansoprazole-based triple therapy for Helicobacter pylori eradication.

Triple therapy with a proton pump inhibitor (PPI), amoxicillin, and clarithromycin is widely accepted for Helicobacter pylori eradication. The choice of PPI for triple therapy in Israel is arbitrary, with no preference for any one PPI except for economic considerations. Direct comparison between omeprazole and lansoprazole for efficacy of H. pylori eradication has never been performed in an Israeli poplulation. Based on the pharmacokinetic data, lansoprazole-based therapy may be a better alternative than omeprazole-based therapy. The aim of this study was to compare the effectiveness of triple therapy regimens with omeprazole (Losec, AstraZeneca; or Omeradex, Dexxon) or lansoprazole (TAP Pharmaceuticals) in eradicating H. pylori infection. The database of the biggest health insurance provider in Israel was reviewed for all patients who received 1 week of treatment with omeprazole (n = 1293) or lansoprazole (n = 85) with additional amoxicillin and clarithromycin for H. pylori eradication in 2002. All patients underwent the 13C-urea breath test (13CUBT) for validation of eradication. A negative 13CUBT result was noted in 1026 of the patients treated with omeprazole (79.4%) and 61 treated with lansoprazole (71.8%). On logistic regression analysis, none of the confounding factors (sex, age, indication, chronic use of PPI, eradication protocol) were found to contribute to the discrimination between a negative (successful eradication) and a positive (failed eradication) 13CUBT. There is no statistically significant difference between omeprazole and lansoprazole as part of a PPI-based triple therapy for eradication of H. pylori.

2-Pyridinylmethylsulfinylbenzimidazoles↗
PubMed2005

Minidose aspirin and gastrointestinal bleeding--a retrospective, case-control study in hospitalized patients.

Low or minimal doses of aspirin are widely used for prevention of cardiovascular diseases. Aspirin is known to produce severe adverse gastrointestinal effects, such as bleeding and perforation. Less is known about the risk associated with minidose aspirin. Our aim was to assess the possible association of upper gastrointestinal tract bleeding with minidose aspirin therapy. A retrospective controlled design was used. Patients hospitalized for melena or hematemesis between January 1, 2000, and December 31, 2001, were identified by ICD-9 codes, and their clinical findings were compared to these of patients without upper gastrointestinal bleeding hospitalized during the same period and matched for age and sex. Bleeding was attributed to therapy if patients used a nonsteroidal anti-inflammatory drug or aspirin therapy within 30 days before hospitalization. The study group included 318 patients (59% male), and the control group 141 (65% male). Mean ages were 67 +/- 19 and 64 +/- 19 years, respectively. Study patients had more accompanying diseases, used more medications, and required more blood transfusions than controls (37%, vs. 2% of controls; P < 0.001). Minidose aspirin was used by 28% of the study group and 18% of the controls (P = 0.03). The average dose was 40 +/- 86 and 21 +/- 55 mg/day, respectively (P = 0.012). Only 26% of the study patients received a gastric protective agent. On multivariate analysis, aspirin consumption was the only independent risk factor for upper gastrointestinal tract bleeding. There appears to be an association between minidose aspirin treatment and hospitalization for upper gastrointestinal tract bleeding. Despite the advanced age of the patients, only one-quarter were treated with gastric protective agent.

Aged↗
PubMed2005

Capsule endoscopy examination--preliminary review by a nurse.

Capsule endoscopy (CE) has been recommended as the method of choice for diagnostic endoscopy of the small bowel. An experienced nurse, after proper training, may contribute to the endoscopy procedures as previously described for sigmoidoscopy. The aim of this study was to evaluate the ability of an experienced gastroenterology nurse to prepare CE records for physician interpretation, by detecting abnormal thumbnails. A prospective, observational design was used. Fifty CE videos were pre-read by a specially trained gastroenterology nurse who thumbnailed the abnormalities detected for interpretation by the gastroenterologist. The nurse's description of the lesions and the calculated gastric and bowel transit times were compared to the interpretation of the videos made directly by the gastroenterologist (gold standard). The primary end point of the study was the quality of the nurse's pathology findings; the secondary end point was the cost effectiveness of this practice. There was complete agreement between the nurse and gastroenterologist for all 12 cases interpreted as normal by the gastroenterologist. In the remaining 38 cases, the nurse created 130 thumbnail selections and the physician, 99. Complete interobserver agreement was achieved for 93 of the 96 lesions categorized as "significant" by the physician (96.9%). After all relevant variables were taken into account, this approach saved dollar 324 per CE examination. The use of nurse practitioner to pre-read CE videos and prepare thumbnail selections for further assessment by the gastroenterologist appears to be safe, reliable, and cost effective.

Clinical Competence↗
PubMed2005

Colonic anastomosis performed with a memory-shaped device.

BACKGROUND: The present study was prompted by our previous successful experience with the compression anastomosis clip (CAC) on animals followed by a study on 20 patients scheduled for colonic resection. METHODS: Sixty patients with colonic cancer were assigned randomly to undergo an anastomosis either with the CAC or a stapler. To perform anastomosis with CAC, the 2 edges of the resected colon are aligned. Two 5-mm incisions are made close to the edges, through which (using a special applier) the CAC, after being cooled in ice water, is introduced in an open position. In response to the body temperature, the clip resumes its original (closed) position, thereby clamping the 2 bowel segments together. At the same time, a small scalpel incorporated in the applier makes a small incision through the clamped walls for the passage of gas and feces. The clip is detached from the applier to be left inside the intestine. The 2 5-mm incisions are sutured. The clip is expelled with the stool within 5 to 7 days, creating a perfect uniform compression anastomosis. RESULTS: Neither group had anastomotic complications such as leakage or obstruction. All the other parameters were better in the study group than in the control patients. CONCLUSIONS: The use of the CAC for colonic surgery is safe, simple, efficient, shortens operation time, and is almost what we call the "no-touch concept" in surgery and may decrease infection.

Aged↗
PubMed2005

Performance characteristics and evaluation of an automated-developed and quantitative, immunochemical, fecal occult blood screening test.

OBJECTIVES: Guaiac fecal occult blood colorectal cancer (CRC) screening tests (FOBT) are faulted for low sensitivity and nonspecificity for human hemoglobin (Hb). Automated-developed, immunochemical, human Hb FOBT (I-FOBT) is specific, eliminates diet restrictions, and Hb quantification allows selection of a threshold for colonoscopy. Aims were to determine 1) test reproducibility; 2) test stability; 3) intrapatient daily I-FOBT variation; 4) test sensitivity and specificity for neoplasia in 500 symptomatic/high-risk patients undergoing colonoscopy; and 5) to correlate fecal Hb measurements with findings. METHODS: The desktop instrument OC-Sensor (Eiken, Japan) automatically develops and quantitates 50 tests/h for Hb. Patients prepared three tests, which were quantified and then 1) repeatedly re-examined; 2) stored at 4 degrees C or 20 degrees C or 28 degrees C and repeatedly examined; and 3) fecal Hb levels were correlated with colonoscopic findings. RESULTS: Five I-FOBTs re-examined five times in 1 day had no significant measurement changes. Thirty tests stored for 21 or more days had a decay/day of 0.3%+/- 0.4 at 4 degrees C (NS), 2.2%+/- 1.7 at 20 degrees C (NS), and 3.7%+/- 1.8 at 28 degrees C (p < 0.05). There were intrapatient variations between the three daily I-FOBTs (NS). At the recommended 100 ng Hb/mL threshold, all six cases of CRCs and 20 out of 28 cases of advanced adenomas were detected; evaluated together their sensitivity and specificity were 76.5% and 95.3%. CONCLUSIONS: Desktop, automated-developed, quantitative I-FOBT is now available. Refrigerated OC-Sensor samples are stable for 21 days, easy to prepare and develop and, at the 100 ng Hb/mL threshold, have high sensitivity, specificity, and negative predictive values for significant neoplasia. Suitability for population CRC screening awaits further evaluation.

Adenoma↗