Genetic effects of radiation in atomic-bomb survivors and their children: past, present and future.
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Genetic studies in the offspring of atomic bomb survivors have been conducted since 1948 at the Atomic Bomb Casualty Commission and its successor, the Radiation Effects Research Foundation, in Hiroshima and Nagasaki. Past studies include analysis of birth defects (untoward pregnancy outcome; namely, malformation, stillbirth, and perinatal death), chromosome aberrations, alterations of plasma and erythrocyte proteins as well as epidemiologic study on mortality (any cause) and cancer incidence (the latter study is still ongoing). There is, thus far, no indication of genetic effects in the offspring of survivors. Recently, the development of molecular biological techniques and human genome sequence databases made it possible to analyze DNA from parents and their offspring (trio-analysis). In addition, a clinical program is underway to establish the frequency of adult-onset multi-factorial diseases (diabetes mellitus, high blood pressure, and cardiovascular disease etc) in the offspring. The complementary kinds of data that will emerge from this three-pronged approach (clinical, epidemiologic, and molecular aspects) promise to shed light on health effects in the offspring of radiation-exposed people. (+info)
Mortality from diseases other than cancer following low doses of ionizing radiation: results from the 15-Country Study of nuclear industry workers.
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BACKGROUND: Ionizing radiation at very high (radio-therapeutic) dose levels can cause diseases other than cancer, particularly heart diseases. There is increasing evidence that doses of the order of a few sievert (Sv) may also increase the risk of non-cancer diseases. It is not known, however, whether such effects also occur following the lower doses and dose rates of public health concern. METHODS: We used data from an international (15-country) nuclear workers cohort study to evaluate whether mortality from diseases other than cancer is related to low doses of external ionizing radiation. Analyses included 275 312 workers with adequate information on socioeconomic status, over 4 million person-years of follow-up and an average cumulative radiation dose of 20.7 mSv; 11 255 workers had died of non-cancer diseases. RESULTS: The excess relative risk (ERR) per Sv was 0.24 [95% CI (confidence intervals) -0.23, 0.78] for mortality from all non-cancer diseases and 0.09 (95% CI -0.43, 0.70) for circulatory diseases. Higher risk estimates were observed for mortality from respiratory and digestive diseases, but confidence intervals included zero. Increased risks were observed among the younger workers (attained age <50 years, identified post hoc) for all groupings of non-cancer causes of death, including external causes. It is unclear therefore whether these findings reflect real effects of radiation, random variation or residual confounding. CONCLUSIONS: The most informative low-dose radiation study to date provides little evidence for a relationship between mortality from non-malignant diseases and radiation dose. However, we cannot rule out risks per unit dose of the same order of magnitude as found in studies at higher doses. (+info)
Decisions made by critical care nurses during mechanical ventilation and weaning in an Australian intensive care unit.
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BACKGROUND: Responsibilities of critical care nurses for management of mechanical ventilation may differ among countries. Organizational interventions, including weaning protocols, may have a variable impact in settings that differ in nursing autonomy and interdisciplinary collaboration. OBJECTIVE: To characterize the role of Australian critical care nurses in the management of mechanical ventilation. METHODS: A 3-month, prospective cohort study was performed. All clinical decisions related to mechanical ventilation in a 24-bed, combined medical-surgical adult intensive care unit at the Royal Melbourne Hospital, a university-affiliated teaching hospital in Melbourne, Victoria, Australia, were determined. RESULTS: Of 474 patients admitted during the 81-day study period, 319 (67%) received mechanical ventilation. Death occurred in 12.5% (40/319) of patients. Median durations of mechanical ventilation and intensive care stay were 0.9 and 1.9 days, respectively. A total of 3986 ventilation and weaning decisions (defined as any adjustment to ventilator settings, including mode change; rate or pressure support adjustment; and titration of tidal volume, positive end-expiratory pressure, or fraction of inspired oxygen) were made. Of these, 2538 decisions (64%) were made by nurses alone, 693 (17%) by medical staff, and 755 (19%) by nurses and staff in collaboration. Decisions made exclusively by nurses were less common for patients with predominantly respiratory disease or multiple organ dysfunction than for other patients. CONCLUSIONS: In this unit, critical care nurses have high levels of responsibility for, and autonomy in, the management of mechanical ventilation and weaning. Revalidation of protocols for ventilation practices in other clinical contexts may be needed. (+info)
Solid cancer incidence and low-dose-rate radiation exposures in the Techa River cohort: 1956 2002.
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BACKGROUND: This is the first analysis of solid cancer incidence in the Techa River cohort, a general population of men and women of all ages who received chronic low-dose rate exposures from environmental radiation releases associated with the Soviet nuclear weapons programme. This cohort provides one of the few opportunities to evaluate long-term human health risks from low-dose radiation exposures. METHODS: Cancer incidence rates in this cohort were analysed using excess relative risk (ERR) models. The analyses make use of individualized dose estimates that take into account residence history, age and other factors. Cases are identified on the basis of continuing, active follow-up of mortality and cancer incidence. RESULTS: Based on 1836 solid cancer cases with 446 588 person years accrued over 47 years of follow-up, solid cancer incidence rates were found to increase with dose and about 3% of the cases were attributable to radiation exposure. The ERR was 1.0/Gy (P = 0.004 95% CI (0.3; 1.9) in a linear dose-response model. There was no significant non-linearity in the dose response and no indication of effect modification by gender, ethnicity, attained age or age at first exposure. CONCLUSIONS: The Techa River cohort provides strong evidence that low-dose, low-dose rate exposures lead to significant increases in solid cancer risks that appear to be linear in dose. The results do not suggest that risks associated with low-dose rate exposures are less than those seen following acute exposures such as were received by atomic bomb survivors. (+info)
Radiologic and nuclear events: contingency planning for hematologists/oncologists.
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Significance of HER2 and C-MYC oncogene amplifications in breast cancer in atomic bomb survivors: associations with radiation exposure and histologic grade.
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