Mechanisms of death in the CABG Patch trial: a randomized trial of implantable cardiac defibrillator prophylaxis in patients at high risk of death after coronary artery bypass graft surgery.
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BACKGROUND: The CABG Patch trial compared prophylactic implantable cardiac-defibrillator (ICD) implantation with no antiarrhythmic therapy in coronary bypass surgery patients who had a left ventricular ejection fraction <0.36 and an abnormal signal-averaged ECG. There were 102 deaths among the 446 ICD group patients and 96 deaths among the 454 control group patients, a hazard ratio of 1.07 (P=0.63). The mechanisms of death were classified, and hypotheses were tested about the effects of ICD therapy on arrhythmic and nonarrhythmic cardiac deaths in the CABG Patch Trial and the Multicenter Automatic Defibrillator Implantation Trial (MADIT). METHODS AND RESULTS: The 198 deaths in the trial were reviewed by an independent Events Committee and classified by the method of Hinkle and Thaler. Only 54 deaths (27%) occurred out of hospital; 145 deaths (73%) were witnessed. Seventy-nine (82%) of the 96 deaths in the control group and 76 (75%) of the 102 deaths in the ICD group were due to cardiac causes. Cumulative arrhythmic mortality at 42 months was 6.9% in the control group and 4.0% in the ICD group (P=0. 057). Cumulative nonarrhythmic cardiac mortality at 42 months was 12. 4% in the control group and 13.0% in the ICD group (P=0.275). Death due to pump failure was significantly associated with death >1 hour from the onset of symptoms, dyspnea within 7 days of death, and overt heart failure within 7 days of death. CONCLUSIONS: In the CABG Patch Trial, ICD therapy reduced arrhythmic death 45% without significant effect on nonarrhythmic deaths. Because 71% of the deaths were nonarrhythmic, total mortality was not significantly reduced. (+info)
Measuring response in solid tumors: unidimensional versus bidimensional measurement.
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BACKGROUND: Tumor shrinkage is a common end point used in screening new cytotoxic agents. The standard World Health Organization criterion for partial response is a 50% or more decrease in the sum of the products of two measurements (the maximum diameter of a tumor and the largest diameter perpendicular to this maximum diameter) of individual tumors. However, theoretically, the simple sum of the maximum diameters of individual tumors is more linearly related to cell kill than is the sum of the bidimensional products. It has been hypothesized that the calculation of bidimensional products is unnecessary, and a 30% decrease in the sum of maximum diameters of individual tumors (assuming spherical shape and equivalence to a 50% reduction in the sum of the bidimensional products) was proposed as a new criterion. We have applied the standard response and the new response criteria to the same data to determine whether the same number of responses in the same patients would result. METHODS: Data from 569 patients included in eight studies of a variety of cancers were reanalyzed. The two response criteria were separately applied, and the results were compared using the kappa statistic. The importance of confirmatory measurements and the frequency of nonspherical tumors were also examined. In addition, for a subset of 128 patients, a unidimensional criterion for disease progression (30% increase in the sum of maximum diameters) was applied and compared with the standard definition of a 25% increase in the sum of the bidimensional products. RESULTS: Agreement between the unidimensional and bidimensional criteria was generally found to be good. The kappa statistic for concordance for overall response was 0.95. CONCLUSION: We conclude that one dimensional measurement of tumor maximum diameter may be sufficient to assess change in solid tumors. (+info)
When to consider radiation therapy for your patient.
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Radiation therapy can be an effective treatment modality for both malignant and benign disease. While radiation can be given as primary treatment, it may also be used pre- or postoperatively, with or without other forms of therapy. Radiation therapy is often curative but is sometimes palliative. There are many methods of delivering radiation effectively. Often, patients tolerate irradiation well without significant complications, and organ function is preserved. To ensure that all patients with cancer have the opportunity to consider all treatment options, family physicians should be aware of the usefulness of radiation therapy. (+info)
Macrophage electrophoretic mobility (MEM) with myelin basic protein.
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Lymphocytes from a total of 161 subjects, including normal controls and patients with malignant and non-malignant conditions, have been investigated for their response to myelin basic protein, using the macrophage electrophoretic mobility (MEM) test. It has been confirmed that there was a high level of association between clinically evident cancer and a positive response. Lymphocytes from 24/25 patients with non-malignant inflammatory and ischaemic diseases also gave positive responses. In 46 patients with breast lumps studied before mastectomy or biopsy, the test was positive in 15/19 cases which proved to be malignant and in 5/27 which proved benign on histological examination. In its present form the test is not sufficiently reliable for the diagnosis of early cancer. Our results suggest that tissue necrosis in malignant and non-malignant conditions may be one of the factors resulting in sensitization to antigenic determinants present in preparations of myelin basic protein. Despite its technical difficulties, the test may provide a means of examing some aspects of immune recall not readily revealed by other test systems. (+info)
Tropisetron (Navoban) in the control of nausea and vomiting induced by combined cancer chemotherapy in children.
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BACKGROUND: We aimed to assess the potency and efficacy of tropisetron, a 5-HT3 receptor antagonist, in the prevention of nausea and emesis observed in the pediatric patient population taking various chemotherapy protocols. METHODS: Tropisetron (Navoban) was given to 100 children (62 boys and 38 girls aged 6 months to 15 years) with various malignancies. Patients received tropisetron during one or more courses of emetogenic chemotherapy for a total of 350 courses administered intravenously or intravenously and intrathecally. Tropisetron (0.2 mg/kg/day, maximum: 5 mg/day) was administered as a single intravenous dose slowly, before the start of chemotherapy on day 1 and intravenously or by mouth on subsequent days (median treatment duration: 5 days). RESULTS: The patients receiving cytotoxic chemotherapy had a 70% complete response rate and a 24% partial response rate during the first 24 h period of the first course. We observed headache (five courses), diarrhea (three courses) and loss of appetite (one course) as side-effects (2.5%). CONCLUSION: Tropisetron is safe, effective, easy to use, has no serious side-effects and can be recommended for pediatric patients. The efficacy of tropisetron may be enhanced by the addition of corticosteroids in patients receiving highly emetogenic cancer chemotherapy. (+info)
Exercise clinical trials in cancer prevention research: a call to action.
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The experimental study design can yield valuable information in measuring the association between physical activity and occurrence of cancers. Randomized clinical exercise trials can provide insight into the avenues through which physical activity might affect cancer development and can provide experience with diffusing an exercise intervention into certain populations. This report describes the potential utility of the randomized clinical trial design in providing answers about bias, mechanisms, behavior change, and dose-response in defining the causal pathway between physical activity and cancer. The challenges and limitations of exercise clinical trial are discussed. The research experience in cardiovascular disease and exercise is used as a model for developing a research agenda to explore the potential role of physical activity as a cancer-prevention modality. We recommend that a series of small clinical trials of exercise interventions be conducted to measure exercise change effects on biomarkers for cancer risk, to learn about exercise behavior change in individuals at risk for cancer, and to serve as feasibility studies for larger randomized controlled trials of cancer and precursor end points and for community intervention studies. (+info)
Water pollution and human health in China.
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China's extraordinary economic growth, industrialization, and urbanization, coupled with inadequate investment in basic water supply and treatment infrastructure, have resulted in widespread water pollution. In China today approximately 700 million people--over half the population--consume drinking water contaminated with levels of animal and human excreta that exceed maximum permissible levels by as much as 86% in rural areas and 28% in urban areas. By the year 2000, the volume of wastewater produced could double from 1990 levels to almost 78 billion tons. These are alarming trends with potentially serious consequences for human health. This paper reviews and analyzes recent Chinese reports on public health and water resources to shed light on what recent trends imply for China's environmental risk transition. This paper has two major conclusions. First, the critical deficits in basic water supply and sewage treatment infrastructure have increased the risk of exposure to infectious and parasitic disease and to a growing volume of industrial chemicals, heavy metals, and algal toxins. Second, the lack of coordination between environmental and public health objectives, a complex and fragmented system to manage water resources, and the general treatment of water as a common property resource mean that the water quality and quantity problems observed as well as the health threats identified are likely to become more acute. (+info)
Tetrachloroethylene-contaminated drinking water in Massachusetts and the risk of colon-rectum, lung, and other cancers.
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We conducted a population-based case-control study to evaluate the relationship between cancer of the colon-rectum (n = 326), lung (n = 252), brain (n = 37), and pancreas (n = 37), and exposure to tetrachloroethylene (PCE) from public drinking water. Subjects were exposed to PCE when it leached from the vinyl lining of drinking-water distribution pipes. Relative delivered dose of PCE was estimated using a model that took into account residential location, years of residence, water flow, and pipe characteristics. Adjusted odds ratios (ORs) for lung cancer were moderately elevated among subjects whose exposure level was above the 90th percentile whether or not a latent period was assumed [ORs and 95% confidence intervals (CIs), 3.7 (1.0-11.7), 3.3 (0.6-13.4), 6.2 (1.1-31.6), and 19.3 (2.5-141.7) for 0, 5, 7, and 9 years of latency, respectively]. The adjusted ORs for colon-rectum cancer were modestly elevated among ever-exposed subjects as more years of latency were assumed [OR and CI, 1.7 (0.8-3.8) and 2.0 (0.6-5.8) for 11 and 13 years of latency, respectively]. These elevated ORs stemmed mainly from associations with rectal cancer. Adjusted ORs for rectal cancer among ever-exposed subjects were more elevated [OR and CI, 2.6 (0. 8-6.7) and 3.1 (0.7-10.9) for 11 and 13 years of latency, respectively] than were corresponding estimates for colon cancer [OR and CI, 1.3 (0.5-3.5) and 1.5 (0.3-5.8) for 11 and 13 years of latency, respectively]. These results provide evidence for an association between PCE-contaminated public drinking water and cancer of the lung and, possibly, cancer of the colon-rectum. (+info)