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B Levin

Publications and source records attributed to B Levin.

At least 19 recordsLinked to original sources
PubMed2006

A two-stage design for a phase II clinical trial of coenzyme Q10 in ALS.

BACKGROUND: The combination of a small pool of patients at any given time with the availability of many potential neuroprotective agents to be tested in ALS requires efficient phase II trial designs. OBJECTIVE: To describe the design of the Clinical Trial of High Dose Coenzyme Q10 (CoQ10) in ALS (QALS study)--a phase II, randomized, placebo-controlled, double-blind, multicenter clinical trial. METHODS: The study design features two stages. The first stage (dose selection) identifies which of two doses of CoQ10 (1800 mg or 2700 mg) is preferred using a selection procedure rather than a formal hypothesis test. The second stage (early efficacy test) compares the preferred dose of CoQ10 against placebo using a non-superiority or futility design. Data from patients assigned to the preferred dose of CoQ10 in the first stage are also used in the second stage. The primary outcome measure is the decline in Amyotrophic Lateral Sclerosis Functional Rating Scale-revised (ALSFRSr) score from baseline to 9 months. RESULTS: The total sample size required is 185 patients, as compared to a much larger sample size estimated to be necessary using a conventional superiority design (total: 852 patients). The authors report a bias correction made necessary by the inclusion of patient data from the first stage in the second stage. CONCLUSIONS: Several features of the Clinical Trial of High Dose Coenzyme Q10 in ALS study design promote efficiency. These features may be beneficial in phase II trials in amyotrophic lateral sclerosis and other fields.

Adult↗
PubMed2006

Geographical clustering of pancreatic cancers in the Northeast Nile Delta region of Egypt.

The northeast Nile Delta, Egypt's most polluted region, appears to have a high incidence of pancreatic cancer. We sought to determine whether there is any geographic clustering of pancreatic cancers there and, if so, whether such clustering might be associated with environmental pollution. Using data from the medical records of the Gastrointestinal Surgical Center of Mansoura University in the Dakahleia Province of Egypt and detailed geographical maps of the northeast Nile Delta region, we plotted the residences of all 373 patients who had pancreatic cancer diagnosed between 1995 and 2000. The study region has 15 administrative districts, whose centroid coordinates, population, and number of pancreatic cancer patients were determined for this study. Monte Carlo simulation identified statistically significant clustering of pancreatic cancer in five subdivisions located near the Nile River and Delta plains. This clustering was independent of population size and formed two larger clusters. When data were analyzed by sex, clustering of pancreatic cancer was observed in the same five subdivisions for men but only two subdivisions showed clustering for women. Together, our data suggest that there is clustering of pancreatic cancer cases in the northeast Nile delta region and that this clustering may be related to water pollution. Our data also warrant future studies of the association between water pollution and pancreatic cancer in the region.

Aged↗
PubMed2006

The Aer-O-Scope: proof of the concept of a pneumatic, skill-independent, self-propelling, self-navigating colonoscope in a pig model.

BACKGROUND AND STUDY AIMS: Considerable training is needed to enable endoscopists to use the currently available commercial colonoscopes and sigmoidoscopes effectively and safely. The aim of this study was to evaluate the safety and efficacy of the propulsion mechanism incorporated into the Aer-O-Scope (GI View Ltd., Ramat Gan, Israel)--a novel self-propelled, self-navigating colonic endoscope for diagnostic purposes. MATERIALS AND METHODS: Twenty young female pigs underwent complete bowel preparation followed by a sedated examination using the new device. Ten pigs underwent two consecutive procedures, with a wash-out period of 7 days between each procedure. The total number of procedures was 30. Two prototypes of the Aer-O-Scope, with different cable lengths and vehicle balloon sizes (n = 20 and n = 10 for prototypes I and II, respectively) were used. Each examination was followed by a standard colonoscopy for safety evaluation. The insertion length of the Aer-O-Scope was determined by fluoroscopy images. RESULTS: The colon was adequately clean in 25 procedures. Maximum insertion was achieved in 21 procedures (84%)--80% with prototype I (n = 15) and 90% with prototype II (n = 10). The time to maximum insertion averaged 8.9 +/- 4.4 min (10 +/- 4.6 and 6.6 +/- 2.9 min for prototypes I and II; P < 0.05), and the withdrawal time averaged 3.4 +/- 2.1 and 4.2 +/- 3.4 min, respectively. The driving pressures for prototypes I and II averaged 46.3 and 34.5 mbar, respectively. The follow-up conventional colonoscopy identified no mucosal tears or perforations. Minor mucosal petechiae were noted in 43% of the cases. No adverse events were noted up to 7 days after the procedure. CONCLUSIONS: The propulsion mechanism used in this novel self-propelled, self-navigating colonoscope was effective and safe in pigs.

Animals↗
PubMed2005

Predictors of antral follicle count during the reproductive years.

BACKGROUND: We sought to identify indicators of antral follicle count which would be serviceable to clinicians seeking to estimate the number of ovarian follicles without relying on sonographic counts. METHODS: We examined the relations of chronological age and four potential indicators of ovarian age-ovarian volume, FSH, dimeric inhibin B and estradiol-to antral follicle count in 176 recently pregnant women. We identified the regression models which best predict low antral follicle count (< or =10 follicles). RESULTS: Chronological age, ovarian volume, FSH and inhibin B were each significantly associated with antral follicle count. Fifty-three (30.1%) women had < or =10 antral follicles. In the total sample, at the cutpoint corresponding to 80% sensitivity, the positive predictive value for a regression model with all four variables was 60%. All regression models performed less well in women <35 years (13.9% with low count) than in women > or =35 years (52.0% with low count). In older women, the positive predictive value for the model with all four variables was 79%, compared with 60% for a model with chronological age alone. CONCLUSIONS: Our models provide a basis for advising women aged > or =35 years who are either trying to conceive or wish to learn whether they may postpone childbearing.

Adult↗
PubMed2005

The ALSFRSr predicts survival time in an ALS clinic population.

OBJECTIVE: To determine whether the Amyotrophic Lateral Sclerosis Functional Rating Scale-revised (ALSFRSr), a predictor of survival time in ALS clinical trials, predicts survival time in an ALS clinic population. METHODS: The authors prospectively evaluated 267 consecutive patients with ALS at first visit to an ALS clinic using the ALSFRSr and pulmonary function testing. The association of ALSFRSr score at baseline with death or tracheostomy in ALS was examined using Cox proportional hazards models, adjusting for age at baseline, sex, and symptom duration. RESULTS: Of 267 patients with ALS, 103 (39%) reached the endpoint, defined as either death (79 patients) or tracheostomy (24 patients), during a mean follow-up of 1.0 +/- 0.7 years. Among the 103 patients who reached the endpoint during follow-up, 77 (75%) had a baseline ALSFRSr score of less than 38 (the median baseline score of all patients), compared to 53 of 164 (32%) who remained alive without tracheostomy. Patients with a total ALSFRSr score below the median had a 4.4-fold increased risk of death or tracheostomy compared to those who scored above the median (HR: 4.38, 95% CI: 2.79 to 6.86, p < 0.001). Both the total ALSFRSr score at baseline (HR: 0.94, 95% CI: 0.91 to 0.98, p < 0.001) and forced vital capacity at baseline (HR: 0.99, 95% CI: 0.98 to 1.00, p = 0.02) were associated with death or tracheostomy when included in the same Cox model. CONCLUSIONS: In an ALS clinic population, the total Amyotrophic Lateral Sclerosis Functional Rating Scale-revised score at baseline is a strong predictor of death or tracheostomy independently of forced vital capacity and after adjustment for age at baseline, sex, and symptom duration.

Age of Onset↗
PubMed2004

Trisomic pregnancy and the oocyte pool.

BACKGROUND: We tested the hypothesis that trisomy risk is increased for women with fewer oocytes (older ovarian age) than other women of the same chronological age. METHODS: Our study compared three indicators of ovarian age-number of antral follicles, level of dimeric inhibin B, level of FSH-among women who had trisomic pregnancy losses (n = 54) with those among women who had other losses (24 with other chromosomally abnormal loses, 21 with chromosomally normal losses) or who had chromosomally normal births (n = 65). RESULTS: Ovarian age indicators did not differ between women with trisomic spontaneous abortions and the three comparison groups. Compared with live birth controls, adjusting for chronological age, we estimate that, on average, among trisomy cases the geometric means of 1 + follicle count, inhibin B and FSH are about 7.5% higher, 16.6% higher and 5.5% lower, respectively, with all 95% confidence intervals including zero. The sample size was sufficient to detect moderate differences (0.52 standard errors of regression) between trisomy cases and live birth controls. CONCLUSIONS: Although our data do not support our hypothesis, they leave open the possibility that changes in follicular development unrelated to the size of the oocyte pool influence abnormal chromosome segregation.

Abortion, Spontaneous↗
PubMed2002

A gender-specific HIV/STD risk reduction intervention for women in a health care setting: short- and long-term results of a randomized clinical trial.

This study assessed the short- and long-term effect of a gender-specific group intervention for women on unsafe sexual encounters and strategies for protection against HIV/STD infection. Family planning clients (N = 360) from a high HIV seroprevalence area in New York City were randomized to an eight-session, a four-session or a control condition and followed at one, six and 12 months post-intervention. Using an intention-to-treat analysis, women who were assigned to the eight-session group had about twice the odds of reporting decreased or no unprotected vaginal and anal intercourse compared to controls at one month (OR = 1.93, 95% confidence interval [CI] = 1.07, 3.48, p = 0.03) and at 12-month follow-up (OR = 1.65, 95% CI = 0.94, 2.90, p = 0.08). Relative to controls, women assigned to the eight-session condition reported during the previous month approximately three-and-a-half (p = 0.09) and five (p < 0.01) fewer unprotected sex occasions at one- and 12-month follow-up, respectively. Women in the eight-session group also reduced the number of sex occasions at both follow-ups, and had a greater odds of first time use of an alternative protective strategy (refusal, outercourse, mutual testing) at one-month follow-up. Results for the four-session group were in the expected direction but overall were inconclusive. Thus, gender-specific interventions of sufficient intensity can promote short- and long-term sexual risk reduction among women in a family planning setting.

Adolescent↗
PubMed2002

A randomised, double blind, placebo controlled study of celecoxib, a selective cyclooxygenase 2 inhibitor, on duodenal polyposis in familial adenomatous polyposis.

BACKGROUND: Non-selective cyclooxygenase (COX) inhibitors (non-steroidal anti-inflammatory drugs) inhibit large bowel carcinogenesis in patients with familial adenomatous polyposis (FAP). Their role in the duodenum of these patients is less certain. The disease modifying activity of specific COX-2 inhibitors has not been explored in humans. PATIENTS AND METHODS: This was a randomised, double blind, placebo controlled study of celecoxib (100 mg twice daily (n=34) or 400 mg twice daily (n=32)) versus placebo (n=17), given orally twice daily for six months to patients with FAP. Efficacy was assessed qualitatively by blinded review of shuffled endoscopy videotapes comparing the extent of duodenal polyposis at entry and at six months and quantitatively by measurement of the percentage change in duodenal area covered by discrete and plaque-like adenomas from photographs of high and low density polyposis. RESULTS: Shuffled and blinded video review showed a statistically significant effect of 400 mg twice daily celecoxib compared with placebo treatment (p=0.033) with all five independent observers scoring a beneficial effect. Overall, patients taking celecoxib 400 mg twice daily showed a 14.5% reduction in involved areas compared with a 1.4% for placebo (p=0.436). However, patients with clinically significant disease at baseline (greater than 5% covered by polyps) showed a 31% reduction in involved areas with celecoxib 400 mg twice daily compared with 8% on placebo (p=0.049). CONCLUSIONS: A panel of five endoscopists found a significant reduction in duodenal polyposis after six months of treatment with celecoxib 400 mg twice daily. COX-2 inhibition may help this otherwise untreatable condition.

Adenomatous Polyposis Coli↗
PubMed2001

A comparison of warfarin and aspirin for the prevention of recurrent ischemic stroke.

BACKGROUND: Despite the use of antiplatelet agents, usually aspirin, in patients who have had an ischemic stroke, there is still a substantial rate of recurrence. Therefore, we investigated whether warfarin, which is effective and superior to aspirin in the prevention of cardiogenic embolism, would also prove superior in the prevention of recurrent ischemic stroke in patients with a prior noncardioembolic ischemic stroke. METHODS: In a multicenter, double-blind, randomized trial, we compared the effect of warfarin (at a dose adjusted to produce an international normalized ratio of 1.4 to 2.8) and that of aspirin (325 mg per day) on the combined primary end point of recurrent ischemic stroke or death from any cause within two years. RESULTS: The two randomized study groups were similar with respect to base-line risk factors. In the intention-to-treat analysis, no significant differences were found between the treatment groups in any of the outcomes measured. The primary end point of death or recurrent ischemic stroke was reached by 196 of 1103 patients assigned to warfarin (17.8 percent) and 176 of 1103 assigned to aspirin (16.0 percent; P=0.25; hazard ratio comparing warfarin with aspirin, 1.13; 95 percent confidence interval, 0.92 to 1.38). The rates of major hemorrhage were low (2.22 per 100 patient-years in the warfarin group and 1.49 per 100 patient-years in the aspirin group). Also, there were no significant treatment-related differences in the frequency of or time to the primary end point or major hemorrhage according to the cause of the initial stroke (1237 patients had had previous small-vessel or lacunar infarcts, 576 had had cryptogenic infarcts, and 259 had had infarcts designated as due to severe stenosis or occlusion of a large artery). CONCLUSIONS: Over two years, we found no difference between aspirin and warfarin in the prevention of recurrent ischemic stroke or death or in the rate of major hemorrhage. Consequently, we regard both warfarin and aspirin as reasonable therapeutic alternatives.

Adult↗
PubMed2001

Contrasting molecular pathology of colorectal carcinoma in Egyptian and Western patients.

Colorectal carcinoma is uncommon in Egypt, but a high proportion of cases occurs before age 40 years and in the rectum. We compared the molecular pathology of 59 representative Egyptian patients aged 10-72 to Western patients with sporadic, young-onset, or hereditary non-polyposis colorectal cancer syndrome (HNPCC)-associated carcinoma and found significant differences. Most Egyptian cancers were rectal (51%) and poorly differentiated (58%). High levels of microsatellite instability (MSI-H) were frequent (37%) and attributable in some cases (36%) to methylation of the promoter of the hMLH1 mismatch repair gene, but no MSI-H cancer had loss of hMSH2 mismatch repair gene product of the type seen with germline hMSH2 mutation in HNPCC. K-ras mutation was uncommon (11%). In subset analyses, high frequencies of MSI-H in rectal carcinomas (36%) and p53 gene product overexpression in MSI-H cancers (50%) were found. MSI-H and K-ras mutation in Egyptians under age 40 were unusual (17% and 0%, respectively), and schistosomiasis was associated with MSI and K-ras mutation. Cluster analysis identified 2 groups: predominantly young men with poorly differentiated mucinous and signet-ring cell colorectal carcinoma lacking K-ras mutation; older patients who had well- or moderately differentiated adenocarcinoma often with MSI-H, K-ras mutation and schistosomiasis. Our findings show that the molecular pathology of colorectal cancer in older as well as younger Egyptians has unique differences from Western patients, and schistosomiasis influences the molecular pathogenesis of some tumours.

Adolescent↗
PubMed2001

Detecting colorectal cancer in stool with the use of multiple genetic targets.

BACKGROUND: Colorectal cancer cells are shed into the stool, providing a potential means for the early detection of the disease using noninvasive approaches. Our goal was to develop reliable, specific molecular genetic tests for the detection of colorectal cancer in stool samples. METHODS: Stool DNA was isolated from paired stools and primary tumor samples from 51 colorectal cancer patients. Three genetic targets-TP53, BAT26, and K-RAS-were used to detect tumor-associated mutations in the stool prior to or without regard to the molecular analyses of the paired tumors. TP53 gene mutations were detected with a mismatch-ligation assay that detects nine common p53 gene mutations. Deletions within the BAT26 locus were detected by a modified solid-phase minisequencing method. Mutations in codons 12 and 13 of K-RAS were detected with a digital polymerase chain reaction-based method. RESULTS: TP53 gene mutations were detected in the tumor DNA of 30 patients, all of whom had the identical TP53 mutation in their stools. Tumors from three patients contained a noninherited deletion at the BAT26 locus, and the same alterations were identified in these patients' stool specimens. Nineteen of 50 tumors tested had a K-RAS mutation; identical mutations were detected in the paired stool DNA samples from eight patients. In no case was a mutation found in stool that was not also present in the primary tumor. Thus, the three genetic markers together detected 36 (71%) of 51 patients (95% confidence interval [CI] = 56% to 83%) with colorectal cancer and 36 (92%) of 39 patients (95% CI = 79% to 98%) whose tumors had an alteration. CONCLUSION: We were able to detect the majority of colorectal cancers by analyzing stool DNA for just three genetic markers. Additional work is needed to determine the specificity of these genetic tests for detecting colorectal neoplasia in asymptomatic patients and to more precisely estimate the prevalence of the mutations and sensitivity of the assay.

Aged↗
PubMed2001

Cocaine-induced persistent dyskinesias.

The authors report a 34-year-old woman with a history of extensive cocaine abuse who developed choreodystonic dyskinesias and an obsessive-compulsive behavior disorder. The abnormal movements and behavior disorder persisted after a 20-month cocaine-free period.

Adult↗
PubMed2001

Glycine antagonist in neuroprotection for patients with acute stroke: GAIN Americas: a randomized controlled trial.

CONTEXT: Elucidation of the ischemic cascade has helped stimulate development of neuroprotective drugs aimed at limiting brain injury in the hours following an ischemic stroke. To date, none of these drugs has shown clinical efficacy. OBJECTIVE: To examine the efficacy of gavestinel (GV150526), an antagonist of the glycine site of the N-methyl-D-aspartate receptor, as a neuroprotective therapy for acute ischemic stroke when administered within 6 hours of symptom onset. DESIGN: The Glycine Antagonist in Neuroprotection (GAIN) Americas trial, a randomized, double-blind placebo-controlled trial with enrollment from April 1998 to October 1999. SETTING: One hundred thirty-two hospital centers across the United States and Canada. PATIENTS: The primary efficacy population consisted of 1367 ischemic stroke patients with a predefined level of limb weakness and functional independence prior to stroke, stratified at randomization by age (</=75 vs >75 years) and initial stroke severity (National Institutes of Health [NIH] Stroke Scale scores of 2-5, 6-13, or >/=14). INTERVENTION: Patients were randomly assigned to receive an intravenous loading dose (800 mg) plus 5 maintenance doses (200 mg every 12 hours) of gavestinel (n = 701) or placebo (n = 666) for 3 days. MAIN OUTCOME MEASURE: Functional capability at 3 months, measured by the Barthel Index (BI), with scores trichotomized as dead/0-55, 60-90, and 95-100, compared between the gavestinel and placebo groups. RESULTS: Treatment groups were well matched for baseline characteristics. For each group, median NIH Stroke Scale was 12, median age was 72 years, and median time to treatment was 5.2 hours. No statistically significant improvement on the 3-month BI trichotomy was demonstrated for gavestinel (P =.79). The proportion who were functionally independent (BI score = 95-100) was 39% in the gavestinel group and 37% in the placebo group. No statistically significant difference in 3-month survival was observed using Kaplan-Meier curves (P =.11). No other secondary end point suggested an advantage for gavestinel. Among the 333 patients (24%) who received recombinant tissue-type plasminogen activator, there was also no benefit for gavestinel (P =.53). There were no serious safety issues. CONCLUSION: In this study, gavestinel administered up to 6 hours after an acute ischemic stroke did not improve functional outcome at 3 months.

Aged↗
PubMed2001

Colorectal cancer screening by primary care physicians in Texas: a rural-urban comparison.

BACKGROUND: Little is known about colorectal cancer (CRC) screening practices of primary care physicians (PCPs) in rural versus urban locations. METHODS: The authors surveyed 3,380 PCP members of the Texas Medical Association (TMA), stratified by specialty and rural/urban status. Factors associated with PCPs' self-reported practices of CRC screening by fecal occult blood test (FOBT) and/or flexible sigmoidoscopy (SIG) were examined using chi-square tests and multivariate regression. RESULTS: Over 80% of both rural and urban PCPs reported CRC screening with the FOBT, while 70% reported screening with SIG. Many reported doing FOBTs in the office versus using the take-home kit. Variations were found in recommended ages and screening intervals among all respondents. CONCLUSIONS: Geographic location was less important than knowledge and attitudes in predicting PCPs' CRC screening practices. More specific education regarding CRC screening guidelines needs to be directed towards all PCPs.

Adult↗
PubMed2001

Can children teach their parents about asthma?

The Open Airways for Schools (OAS) program has been shown to improve the self-management skills and health outcomes of students with asthma in Grades 3 to 5. This report examines the impact of OAS on students' parents. Because pilot studies showed that parental attendance at school-based sessions was low, the authors held six sessions at school for children and gave children homework assignments to complete with parents at home to teach parents about asthma and build support for children's self-management efforts. Analysis of 1-year follow-up data showed that children's participation in OAS was a significant predictor of parental self-management skills (p <.03) and that OAS children's communication was more strongly associated than controls' with parents' self-management (p = .05). The findings show that health education activities brought home from school by children can positively influence parents' self-management of a complex chronic disease such as asthma.

Asthma↗