Electromagnetic fields and breast cancer on Long Island: a case-control study.

The EMF and Breast Cancer on Long Island Study (EBCLIS) was a case-control study designed to evaluate the possible association between exposure to electromagnetic fields (EMFs) and breast cancer. Eligible women were participants in the population-based Long Island Breast Cancer Study Project, were under 75 years of age at enrollment, were residentially stable, and were identified between August 1, 1996, and June 20, 1997. Of those eligible, 576 cases and 585 controls participated in EBCLIS (87% and 83%, respectively). In-home data collection included various spot and 24-hour EMF measurements, ground-current magnetic field measurements, wire mapping of overhead power lines servicing the home, and an interview. Odds ratios and 95% confidence intervals were based on multivariate logistic regression analyses. All odds ratios were close to 1 and nonsignificant. For the highest quartile of 24-hour EMF measurements, the odds ratio was 0.97 (95% confidence interval (CI): 0.69, 1.37) in the bedroom and 1.09 (95% CI: 0.78, 1.51) in the most lived-in room. For the highest exposure category of ground-current measurements, the odds ratio was 1.13 (95% CI: 0.88, 1.44) in the bedroom and 1.08 (95% CI: 0.85, 1.38) in the most lived-in room. These and other EBCLIS results agree with other recent reports of no association between breast cancer and residential EMF exposures.

Study and treatment of post Lyme disease (STOP-LD): a randomized double masked clinical trial.

OBJECTIVE: To determine whether post Lyme syndrome (PLS) is antibiotic responsive. METHODS: The authors conducted a single-center randomized double-masked placebo-controlled trial on 55 patients with Lyme disease with persistent severe fatigue at least 6 or more months after antibiotic therapy. Patients were randomly assigned to receive 28 days of IV ceftriaxone or placebo. The primary clinical outcomes were improvement in fatigue, defined by a change of 0.7 points or more on an 11-item fatigue questionnaire, and improvement in cognitive function (mental speed), defined by a change of 25% or more on a test of reaction time. The primary laboratory outcome was an experimental measure of CSF infection, outer surface protein A (OspA). Outcome data were collected at the 6-month visit. RESULTS: Patients assigned to ceftriaxone showed improvement in disabling fatigue compared to the placebo group (rate ratio, 3.5; 95% CI, 1.50 to 8.03; p = 0.001). No beneficial treatment effect was observed for cognitive function or the laboratory measure of persistent infection. Four patients, three of whom were on placebo, had adverse events associated with treatment, which required hospitalization. CONCLUSIONS: Ceftriaxone therapy in patients with PLS with severe fatigue was associated with an improvement in fatigue but not with cognitive function or an experimental laboratory measure of infection in this study. Because fatigue (a nonspecific symptom) was the only outcome that improved and because treatment was associated with adverse events, this study does not support the use of additional antibiotic therapy with parenteral ceftriaxone in post-treatment, persistently fatigued patients with PLS.

Insulin-like growth factor system in patients with HIV infection: effect of exogenous growth hormone administration.

The purpose of this study was to characterize changes in the levels of insulin-like growth factor-I (IGF-I) and IGF binding proteins (BP) 1, 2, and 3 in HIV-infected adults throughout the course of their disease, and to assess the responsiveness of the IGF system components to growth hormone (GH) administration (6 mg/day) for 2 weeks. Healthy control study subjects (n = 10) were compared with patients who were either HIV-positive (n = 9), had AIDS without weight loss (n = 13), or had AIDS with >10% weight loss (n = 6), all of whom had been free of acute illness for at least 3 months. Under basal conditions, fasting serum concentrations of epinephrine, norepinephrine, cortisol, glucagon, insulin, IGF-I, and IGFBP-3 were not significantly different among the four groups. The serum concentrations of IGFBP-1 and IGFBP-2 were significantly higher in AIDS patients with wasting than in the other three groups (p < .05). In addition, there was a statistically significant positive correlation between the levels of IGFBP- 1 (p = .004) and IGFBP-2 (p = .03) and the stage of disease. Following GH administration, the serum concentrations of insulin and IGF-I were increased in all groups (p < .05). In addition, the increases in insulin levels correlated with stage of disease (p = .004). The responses of the IGFBPs were more variable. GH administration significantly increased the levels of IGFBP-3 in all groups except the patients with AIDS wasting, whereas the levels of IGFBP-1 were significantly decreased in controls and AIDS patients. These results demonstrate that there is a continuum of both elevations in the IGFBPs and altered metabolic responsiveness in patients infected with HIV that increases with the severity of the disease. These data also demonstrate that AIDS patients, who are free from secondary infection, respond to administration of GH by significantly increasing hepatic IGF-I production.

Sample size determination in complex clinical trials comparing more than two groups for survival endpoints.

This paper presents a sample size formula for testing the equality of kappa (> or = 2) survival distributions using the Tarone-Ware class of test statistics in the presence of non-proportional hazards, time dependent losses, non-compliance and drop-in. This method extends the derivation by Lakatos of a sample size formula for comparing two survival distributions. A sample size formula is also presented for the stratified logrank test. We describe how one can utilize these generalized formulae in calculating sample sizes and assessing power in complex multi-arm clinical trials.

Sample size determination for comparing more than two survival distributions.

We examine the asymptotic properties of the Tarone and Ware and Harrington and Fleming classes of test statistics under alternative hypotheses when there are comparisons between more than two survival distributions in the presence of arbitrary right censoring. When we assume equal censoring distributions across treatment groups and proportional hazards, we derive the sample size formula for testing the equality of k > or = 2 survival distributions using the logrank test. This work extends Schoenfeld's derivation for comparing two survival distributions and also generalizes the results of Makuch and Simon. We also derive the sample size formula for testing monotone dose-response using Tarone's trend test. We then investigate the practicality of the formula in various situations by presenting empirical power with use of Monte Carlo simulations. In addition, with stratification present, we derive the sample size formula for the stratified logrank test, which is an extension of Palta and Amini.