scholarly journals O6B.3 Risk of leukemia after chronic exposure to gamma radiation among ontario uranium miners?

2019 ◽  
Vol 76 (Suppl 1) ◽  
pp. A53.3-A54
Author(s):  
Minh Do ◽  
Avinash Ramkissoon ◽  
Colin Berriault ◽  
Paul Villeneuve ◽  
Paul Demers
Keyword(s):  
At Risk ◽  
Gamma Radiation ◽  
Radiation Exposure ◽  
Prediction Models ◽  
Atomic Bomb ◽  
Linear Trend ◽  
Whole Body ◽  
Calendar Period ◽  
Uranium Miners ◽  
Incident Cases

Background and objectivesIncreases in leukemia risk after exposure to gamma radiation have been well-demonstrated among nuclear energy workers and atomic bomb survivors. Although uranium miners are also exposed to gamma radiation, its health effects are not well characterized, and assumed to be insignificant relative to the effects of radon decay products. The objective of this study is to quantify the effects of whole-body gamma radiation exposure on the incident risk of leukemia among Ontario Uranium Miners.MethodsBased on a retrospective cohort of 28 546 uranium miners, leukemia cases were identified through record linkages with the Canadian Cancer Registry and Canadian Mortality Database. Gamma doses were estimated through dose prediction models and badge dosimeter readings collated by the National Dose Registry, blinded from case status. Person-years at risk of leukemia were stratified by exposure category, calendar period of employment, and attained age at risk. Poisson regression was used to model the risk (RR) of incident leukemia at increasing levels of cumulative gamma radiation exposure, adjusting for calendar period and attained age.ResultsBetween 1969 and 2005, 116 incident cases of leukemia were identified. On average, these miners were employed for 4.4 years with a mean cumulative dose of 5.25 millisieverts (mSv). With exposure lagged by 2 years, preliminary analyses showed that when compared to the referent group (0 mSv), those with >30 mSv of cumulative gamma dose had a non-statistically significant increase in the risk of leukemia diagnosis (RR=2.04, 95% CI: 0.93, 4.51) with increasing, linear trend (p=0.08).ConclusionsAlthough our results did not show a statistically significant relationship between gamma radiation and leukemia incidence, it is likely due to low statistically power. Future work may include pooling the Ontario Uranium Miners cohort with other similar cohorts to better quantify the potential associated risks.

Gamma radiation affects active electrolyte transport by rabbit ileum: basal Na and Cl transport

1986 ◽  
Vol 250 (4) ◽  
pp. G540-G545 ◽  
Author(s):  
P. J. Gunter-Smith
Keyword(s):  
Gamma Radiation ◽  
Radiation Exposure ◽  
Short Circuit ◽  
Transport Processes ◽  
Electrolyte Transport ◽  
Electrolyte Imbalance ◽  
Whole Body ◽  
Cellular Transport ◽  
Rabbit Ileum

The effect of whole-body gamma radiation (5-12 Gy) on electrolyte transport by rabbit ileum in vitro was assessed for 1-96 h postirradiation using the short-circuit technique and radioisotopic fluxes. Although there was no effect of radiation on short-circuit current (Isc), transepithelial potential, or resistance 1 h after exposure, by 24 h the basal parameters of ileal segments isolated from irradiated animals were significantly greater than those of sham-irradiated controls. The Isc increased in a dose-dependent fashion and was greatest 24 h postexposure. Isotope flux experiments revealed that the increased Isc following irradiation resulted in part from a stimulation of active serosal-to-mucosal net Cl flux. There was no observable change in net Na transport. The results demonstrate that radiation exposure alters cellular transport processes, which may contribute to the fluid and electrolyte imbalance observed following radiation exposure.

scholarly journals Chromosome Damage Caused by Accidental Chronic Whole-Body Gamma Radiation Exposure in Thailand

Dose-Response ◽  
2015 ◽  
Vol 13 (4) ◽  
pp. 155932581561430 ◽  
Author(s):  
B. A. Ulsh ◽  
J. Dolling ◽  
J. Lavoie ◽  
R. E. J. Mitchel ◽  
D. R. Boreham
Keyword(s):  
Gamma Radiation ◽  
Radiation Exposure ◽  
Whole Body ◽  
Chromosome Damage

Radioiodine treatment of feline hyperthyroidism in Germany

2002 ◽  
Vol 41 (06) ◽  
pp. 245-251 ◽  
Author(s):  
M. Knietsch ◽  
T. Spillmann ◽  
E.-G. Grünbaum ◽  
R. Bauer ◽  
M. Puille
Keyword(s):  
Radiation Exposure ◽  
Radiation Protection ◽  
Thyroid Function ◽  
Radioiodine Therapy ◽  
Whole Body ◽  
Radioiodine Treatment ◽  
Normal Thyroid ◽  
Normal Thyroid Function ◽  
Body Activity ◽  
Thyroid Uptake

SummaryAim: Establishment of radioiodine treatment of feline hyperthyroidism in veterinary routine in accordance with German radiation protection regulations. Patients and methods: 35 cats with proven hyperthyroidism were treated with 131I in a special ward. Thyroid uptake and effective halflife were determined using gammacamera dosimetry. Patients were released when measured whole body activity was below the limit defined in the German “Strahlenschutzverordnung”. Results: 17/20 cats treated with 150 MBq radioiodine and 15/15 cats treated with 250 MBq had normal thyroid function after therapy, normal values for FT3 and FT4 were reached after two and normal TSH levels after three weeks. In 14 cats normal thyroid function was confirmed by controls 3-6 months later. Thyroidal iodine uptake was 24 ± 10%, effective halflife 2.5 ± 0.7 days. Whole body activity <1 MBq was reached 13 ± 4 days after application of 131I. Radiation exposure of cat owners was estimated as 1.97 Sv/MBq for adults. Conclusion: Radioiodine therapy of feline hyper-thyroidism is highly effective and safe. It can easily be performed in accordance with German radiation protection regulations, although this requires hospitalisation for approximately two weeks. Practical considerations on radiation exposure of cat owners do not justify this long interval. Regulations for the veterinary use of radioactive substances similar to existing regulations for medical use in humans are higly desirable.

PET/CT

2005 ◽  
Vol 44 (S 01) ◽  
pp. S51-S57 ◽  
Author(s):  
T. Beyer ◽  
G. Brix
Keyword(s):  
Diagnostic Accuracy ◽  
Radiation Exposure ◽  
Dose Reduction ◽  
Pet Imaging ◽  
Clinical Studies ◽  
Review Article ◽  
Whole Body ◽  
High Radiation ◽  
Radiation Burden ◽  
Pet Ct

Summary:Clinical studies demonstrate a gain in diagnostic accuracy by employing combined PET/CT instead of separate CT and PET imaging. However, whole-body PET/CT examinations result in a comparatively high radiation burden to patients and thus require a proper justification and optimization to avoid repeated exposure or over-exposure of patients. This review article summarizes relevant data concerning radiation exposure of patients resulting from the different components of a combined PET/CT examination and presents different imaging strategies that can help to balance the diagnostic needs and the radiation protection requirements. In addition various dose reduction measures are discussed, some of which can be adopted from CT practice, while others mandate modifications to the existing hardand software of PET/CT systems.

scholarly journals Development and validation of prediction models for mechanical ventilation, renal replacement therapy, and readmission in COVID-19 patients

2021 ◽  
Author(s):  
Victor Alfonso Rodriguez ◽  
Shreyas Bhave ◽  
Ruijun Chen ◽  
Chao Pang ◽  
George Hripcsak ◽  
...  
Keyword(s):  
At Risk ◽  
Mechanical Ventilation ◽  
Renal Replacement Therapy ◽  
Receiver Operating Characteristic ◽  
Replacement Therapy ◽  
Operating Characteristic ◽  
Prediction Models ◽  
External Validation ◽  
Electronic Health Record Data ◽  
Receiver Operating

Abstract Objective Coronavirus disease 2019 (COVID-19) patients are at risk for resource-intensive outcomes including mechanical ventilation (MV), renal replacement therapy (RRT), and readmission. Accurate outcome prognostication could facilitate hospital resource allocation. We develop and validate predictive models for each outcome using retrospective electronic health record data for COVID-19 patients treated between March 2 and May 6, 2020. Materials and Methods For each outcome, we trained 3 classes of prediction models using clinical data for a cohort of SARS-CoV-2 (severe acute respiratory syndrome coronavirus 2)–positive patients (n = 2256). Cross-validation was used to select the best-performing models per the areas under the receiver-operating characteristic and precision-recall curves. Models were validated using a held-out cohort (n = 855). We measured each model’s calibration and evaluated feature importances to interpret model output. Results The predictive performance for our selected models on the held-out cohort was as follows: area under the receiver-operating characteristic curve—MV 0.743 (95% CI, 0.682-0.812), RRT 0.847 (95% CI, 0.772-0.936), readmission 0.871 (95% CI, 0.830-0.917); area under the precision-recall curve—MV 0.137 (95% CI, 0.047-0.175), RRT 0.325 (95% CI, 0.117-0.497), readmission 0.504 (95% CI, 0.388-0.604). Predictions were well calibrated, and the most important features within each model were consistent with clinical intuition. Discussion Our models produce performant, well-calibrated, and interpretable predictions for COVID-19 patients at risk for the target outcomes. They demonstrate the potential to accurately estimate outcome prognosis in resource-constrained care sites managing COVID-19 patients. Conclusions We develop and validate prognostic models targeting MV, RRT, and readmission for hospitalized COVID-19 patients which produce accurate, interpretable predictions. Additional external validation studies are needed to further verify the generalizability of our results.

scholarly journals Assessment of internal radiation exposure of nuclear medicine workers using whole body gamma counter

2020 ◽  
Vol 1497 ◽  
pp. 012026
Author(s):  
A Norhayati ◽  
M S Suzilawati ◽  
Z Nur Khairunisa ◽  
Y T L Raymond ◽  
A Azimawati
Keyword(s):  
Nuclear Medicine ◽  
Radiation Exposure ◽  
Whole Body ◽  
Internal Radiation ◽  
Gamma Counter

scholarly journals Improving drug safety predictions by reducing poor analytical practices

2020 ◽  
Vol 4 ◽  
pp. 239784732097863
Author(s):  
Stanley E Lazic ◽  
Dominic P Williams
Keyword(s):  
At Risk ◽  
Drug Discovery ◽  
Drug Safety ◽  
Prediction Models ◽  
Predictive Modelling ◽  
Equal Weight ◽  
Negative Consequences ◽  
Preclinical Data ◽  
Safety Pharmacology ◽  
Patients At Risk

Predicting the safety of a drug from preclinical data is a major challenge in drug discovery, and progressing an unsafe compound into the clinic puts patients at risk and wastes resources. In drug safety pharmacology and related fields, methods and analytical decisions known to provide poor predictions are common and include creating arbitrary thresholds, binning continuous values, giving all assays equal weight, and multiple reuse of information. In addition, the metrics used to evaluate models often omit important criteria and models’ performance on new data are often not assessed rigorously. Prediction models with these problems are unlikely to perform well, and published models suffer from many of these issues. We describe these problems in detail, demonstrate their negative consequences, and propose simple solutions that are standard in other disciplines where predictive modelling is used.

scholarly journals Radiation effects on atherosclerosis in atomic bomb survivors: a cross‐sectional study using structural equation modeling

2021 ◽  
Vol 36 (4) ◽  
pp. 401-414
Author(s):  
Tomoki Nakamizo ◽  
John Cologne ◽  
Kismet Cordova ◽  
Michiko Yamada ◽  
Tetsuya Takahashi ◽  
...  
Keyword(s):  
Arterial Stiffness ◽  
Radiation Exposure ◽  
Structural Equation ◽  
Atomic Bomb ◽  
Cross Sectional Study ◽  
Equation Modeling ◽  
Study Cohort ◽  
Sectional Study ◽  
Cross Sectional ◽  
Atomic Bomb Survivors

AbstractPast reports indicated that total-body irradiation at low to moderate doses could be responsible for cardiovascular disease risks, but the mechanism remains unclear. The purpose of this study was to investigate the association between radiation exposure and atherosclerosis, an underlying pathology of cardiovascular diseases, in the Japanese atomic bomb survivors. We performed a cross-sectional study measuring 14 clinical-physiological atherosclerosis indicators during clinical exams from 2010 to 2014 in 3274 participants of the Adult Health Study cohort. Multivariable analyses were performed by using a structural equation model with latent factors representing underlying atherosclerotic pathologies: (1) arterial stiffness, (2) calcification, and (3) plaque　as measured with indicators chosen a priori on the basis of clinical-physiological knowledge. Radiation was linearly associated with calcification (standardized coefficient per Gy 0.15, 95 % confidence interval: CI [0.070, 0.23]) and plaque (0.11, 95 % CI [0.029, 0.20]), small associations that were comparable to about 2 years of aging per Gy of radiation exposure, but not with arterial stiffness (0.036, 95 % CI [− 0.025, 0.095]). The model fitted better and had narrower confidence intervals than separate ordinary regression models explaining individual indicators independently. The associations were less evident when the dose range was restricted to a maximum of 2 or 1 Gy. By combining individual clinical-physiological indicators that are correlated because of common, underlying atherosclerotic pathologies, we found a small, but significant association of radiation with atherosclerosis.

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