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PubMed1977

Oligonucleotide mapping of non-radioactive virus and messenger RNAs.

A modification of the known method for obtaining radioactive fingerprints from non-radioactive nucleic acids by labelling a digest with 5'-hydroxyl polynucleotide kinase and [gamma-32P]-ATP has been applied to RNase T1 digests from various high molecular weight virus RNAs and to ovalbumin mRNA. Fractionation of the resultant [32P]-labelled T1 RNase digests by two-dimensional polyacrylamide electrophoresis demonstrates that in the case of virus RNAs, the fingerprints thus obtained are very similar to those derived from uniformly labelled RNAs. The value of this technique is that it requires only 1-5 microgram of purified virus RNA and at least three orders of magnitude less radioactivity than is routinely employed in preparing uniformly labelled RNA.

Adenosine Triphosphate↗
PubMed1988

Radioactive iodine therapy and breast cancer. A follow-up study of hyperthyroid women.

A follow-up study of 1,762 hyperthyroid women who were treated at the Massachusetts General Hospital Thyroid Unit between 1946 and 1964 was conducted. The average length of follow-up was 17.2 years. A 1978 mailing address or a death certificate was located for 92% of the women, and 88% of 1,058 living patients responded to a mail questionnaire. The standardized mortality ratio (SMR) for all causes of death was 1.3 (95% confidence interval (CI) 1.2-1.4). The standardized mortality ratios for all malignant neoplasms and for breast cancer were 0.9 (95% CI 0.7-1.1) and 1.3 (95% CI 0.8-1.9), respectively. More deaths than expected were observed from endocrine and metabolic diseases (SMR = 1.8, 95% CI 1.2-2.7), circulatory system diseases (SMR = 1.4, 95% CI 1.3-1.6), and respiratory system diseases (SMR = 1.9, 95% CI 1.3-2.6). The standardized incidence ratios (SIR) for all malignant neoplasms and for breast cancer were 0.9 (95% CI 0.8-1.1) and 1.2 (95% CI 0.9-1.5), respectively. A nonsignificant excess breast cancer risk was observed 10 years after the onset of thyroid symptoms and was present at the end of 30 years of observation. A statistically significant excess number of pancreatic cancer cases (SIR = 2.0, 95% CI 1.0-3.7) and a nonsignificant excess of brain cancer cases (SIR = 2.3, 95% CI 0.7-5.3) were observed. Eighty per cent of the women were treated with radioactive iodine. When age at treatment and year of treatment were controlled, women who were ever treated with radioactive iodine had a standardized rate ratio for breast cancer of 1.9 (95% CI 0.9-4.1), compared with those who were never treated with radioactive iodine. Women who developed hypothyroidism as a result of their treatment for hyperthyroidism did not have an increased risk of developing breast cancer (SIR = 1.1, 95% CI 0.8-1.6).

Adult↗
PubMed2004

Induced radioactivity in CU targets produced by high-energy heavy ions and the corresponding estimated photon dose rates.

Irradiation experiments were performed at the Heavy Ion Medical Accelerator in Chiba (HIMAC) facility, National Institute of Radiological Sciences. The radioactive spallation products in a thick Cu target were obtained for Ar(230, 400 MeV per nucleon), Si(800 MeV per nucleon), Ne(100, 230, 400 MeV per nucleon), C(100, 230, 400 MeV per nucleon), He(100, 230 MeV per nucleon), p(100, 230 MeV) ions. The gamma-ray spectra from irradiated Cu samples inserted into the composite Cu target were measured with a high-purity germanium (HPGe) detector. From the gamma-ray spectra, we obtained the spatial distribution of radioactive yields of spallation products of 40 nuclides in the Cu sample in the Cu target. From the spatial distribution of radioactive yields, we estimated the residual activity and photon dose induced in the Cu target. The residual activity and photon dose become larger with the increase in projectile energy per nucleon and the range of the projectile beam for the same projectile energy per nucleon.

Copper↗
PubMed2005

Induced radioactivity in the forward shielding and semiconductor tracker of the ATLAS detector.

The radioactivity induced in the forward shielding, copper collimator and semiconductor tracker modules of the ATLAS detector has been studied. The ATLAS detector is a long-term experiment which, during operation, will require to have service and access to all of its parts and components. The radioactivity induced in the forward shielding was calculated by Monte Carlo methods based on GEANT3 software tool. The results show that the equivalent dose rates on the outer surface of the forward shielding are very low (at most 0.038 microSv h(-1)). On the other hand, the equivalent dose rates are significantly higher on the inner surface of the forward shielding (up to 661 microSv h(-1)) and, especially, at the copper collimator close to the beampipe (up to 60 mSv h(-1)). The radioactivity induced in the semiconductor tracker modules was studied experimentally. The module was activated by neutrons in a training nuclear reactor and the delayed gamma ray spectra were measured. From these measurements, the equivalent dose rate on the surface of the semiconductor tracker module was estimated to be < 100 microSv h(-1) after 100 d of Large Hadron Collider (LHC) operation and 10 d of cooling.

Construction Materials↗
PubMed2005

Non-destructive method of characterisation of radioactive waste containers using gamma spectroscopy and Monte Carlo techniques.

During the decommissioning of the SATURNE accelerator at CEA Saclay (France), a number of concrete containers with radioactive materials of low or very low activity had to be characterised before their final storage. In this paper, a non-destructive approach combining gamma ray spectroscopy and Monte Carlo simulations is used in order to characterise massive concrete blocks containing some radioactive waste. The limits and uncertainties of the proposed method are quantified for the source term activity estimates using 137Cs as a tracer element. A series of activity measurements with a few representative waste containers were performed before and after destruction. It has been found that neither was the distribution of radioactive materials homogeneous nor was its density unique, and this became the major source of systematic errors in this study. Nevertheless, we conclude that by combining gamma ray spectroscopy and full scale Monte Carlo simulations one can estimate the source term activity for some tracer elements such as 134Cs, 137Cs, 60Co, etc. The uncertainty of this estimation should not be bigger than a factor of 2-3.

Algorithms↗
PubMed2006

Study of gel materials as radioactive 222Rn gas detectors.

Commercial hair gel material (polyvinyl pyrolydone triethanolamine carbopol in water) and bacteriological agar (phycocolloid extracted from a group of red-purple algae, usually Gelidium sp.) have been studied as radioactive radon gas detectors. The detection method is based on the diffusion of the radioactive gas in the gel material, and the subsequent measurement of trapped products of the natural decay of radon by gamma spectrometry. From the several radon daughters with gamma radiation emission (214Pb, 214Bi, 214Po, 210Pb, 210Po), two elements, 214Pb (0.352 MeV) and 214Bi (0.609 MeV), were chosen for the analysis in this work; in order to determine the best sensitivity, corrections were made for the short half-life of the analysed isotopes. For the gamma spectrometry analysis, a hyperpure germanium solid state detector was used, associated with a PC multichannel analyser card with Maestro and Microsoft Excel software. The results show the viability of the method: a linear response in a wide radon concentration range (450-10,000 Bq m(-3)), reproducibility of data, easy handling and low cost of the gel material. This detection methodology opens new possibilities for measurements of radon and other radioactive gases.

Dose-Response Relationship, Radiation↗
PubMedDate not supplied

Measurement of fat absorption utilizing 131iodine-triolein and nonabsorbable radioactive markers.

To eliminate many of the practical problems inherent in the collection of feces and in the chemical determination of fecal fat, a radioactive marker (131Ba) was combined with a labeled fat (131l-triolein) to measure fat absorption in man. The ratios of radioactivity of 131Ba/131l in a prepared capsule and that found in a random "grab" stool specimen after oral administration of the capsule were compared to determine the amount of fat absorbed. In an initial 36 patients, this double-label technique accurately separated normal from abnormal fat absorption as determined by the usual methods of quantitative fecal fat measurement. Results in an additional 102 patients and in 26 normals accurately reflected their clinical states. In addition, in vitro studies demonstrated more complete recovery of added lipid (99 percent) by radioactive techniques than by chemical analysis (86 per cent). The double-label technique not only seems more accurate than usual quantitative fecal fat determinations, but also greatly simplifies the measurement of fat absorption in man by eliminating the need for special diets, quantitative stool collections, and chemical analysis of stool.

Barium↗
PubMed2000

Delayed recovery of thyrotropin responsiveness after radioactive iodine therapy for hyperthyroidism.

BACKGROUND: After radioactive iodine therapy for hyperthyroidism, an expected lag in the responsiveness of thyrotropin (TSH) is 60 to 90 days. In our experience, however, many patients seemed to have a more prolonged lag in TSH recovery. METHODS: A retrospective chart review was performed in 58 patients who underwent radioactive iodine therapy for hyperthyroidism (52 with Graves disease, 5 with toxic nodular goiters, and 1 with a toxic adenoma). RESULTS: Forty-nine patients (84%) had appropriate responses of TSH for their level of serum thyroid hormone. Thirty-one became hypothyroid, 12 became euthyroid, and 6 remained hyperthyroid. Nine patients (16%) had a lag in their TSH responsiveness. The TSH remained low for 3 months in 5 patients, for 9 months in 3 patients, and 1 patient had low levels of serum TSH for at least 12 months. CONCLUSIONS: After radioactive iodine therapy for hyperthyroidism, decisions upon further therapy must be based upon the clinical status as well as the serum levels of TSH and thyroid hormones.

Adult↗
PubMed1982

Bone scintigraphy in pulmonary alveolar microlithiasis: a comparative study of radioactivity and density distribution.

A histologically proven case of pulmonary alveolar microlithiasis that demonstrated intense lung uptake of Tc-99m-MDP on a bone scan is presented. The spatial distribution within the lungs of the radioactivity and density was assessed either by single photon emission computed tomography (SPECT), or x-ray computed tomography (CT) respectively, and the regional magnitude of the two parameters were compared. The quantitative study of regional radioactivity and density revealed that both the parameters distributed symmetrically, showing gradual increase in magnitude from the upper to the lower lung regions. The radioactivity-density association observed in our patient may indicate on-going formation of microcalculi throughout the lungs, the degree of which is greater at the sites of more severe involvement.

Bone and Bones↗
PubMed1996

Radioactive synoviorthesis in hemophilic hemarthrosis: materials, techniques, and dangers.

Radioactive synoviorthesis with 198Au, 90Y, 186Re, and 31P would seem to be the treatment of choice for recurrent hemarthroses in hemophilia. The clinical results, obtained by different centers, show a definite diminution of hemarthroses in 88% of cases. The advantages of radioactive synoviorthesis compared with surgical synovectomy are: better results, the requirement of substantially reduced antihemophilic factor, the possibility of performing the procedure on multiple cases concurrently on an ambulatory basis, no interference with articular range of movement, and the low cost of the procedure. In cases of failure, the procedure can be repeated after 6 months, and on as many as 3 occasions. Studies performed on the chromosomal changes that could be attributed to the radioactive material show the disappearance of these alterations a few years after treatment. No physical changes have been found that could be attributed to cytogenic alteration (hematologic or other) in any reported patients.

Adolescent↗
PubMed1989

Risks of radioactive material transportation accidents in Oregon.

As a continuation of previous research on worst case transportation accidents involving radioactive material (Dodd and Humphries 1988a), and protective action guidance for radioactive material transportation accidents (Dodd and Humphries 1988b), this paper describes the risks from such accidents in Oregon. Radioactive material transportation risks are defined in terms of accident consequences multiplied by the accident probabilities and are expressed as latent cancer fatalities (LCFs). For each of 17 different shipment types, five dose contributions are summed and multiplied by the population density and accident probability. The five dose contributors considered are: inhalation, resuspension, cloudshine, groundshine and direct exposure. The variables over which each of these dose contributors are integrated include seven accident severity categories, three population density zones, five regions of the state, as well as many isopleth areas and radionuclides. Allowance is also made for the possible distribution of meteorological conditions in each area. The dose to the public, emergency responders, pedestrians and personnel in other traffic are all considered. It is concluded that the current level of risk is 1.2 X 10(-5) latent cancer fatalities per year in Oregon. This is equivalent to one LCF every 83,000 y. This compares to 1.2 non-radiological fatalities associated from the same shipments.

Accidents↗
PubMed1991

Compliance testing of reusable containers for transport of type A packages of radioactive material.

Transporting radioactive materials within a medical complex comes under jurisdiction of the U.S. Department of Transportation when public highways are used. A strong, reusable container to safely transport radioactive material was developed and tested at Mayo Medical Center to satisfy the requirements of the U.S. Department of Transportation and Nuclear Regulatory Commission. The container successfully completed water spray, free drop, compression, and penetration tests. It has been in use for 3 y without any loss of radioactive materials.

Drug Packaging↗
PubMed1993

Analyses of radioactive aerosols to support accurate internal dose assessments at Chin-Shan nuclear power plant.

Studies of the physical and chemical properties of radioactive aerosols produced in different work environments were made at Chin-Shan nuclear power plant in Taiwan. These properties, including particle mass- and activity-size distributions, elemental and radionuclide compositions, and solubility lung class, are essential for the assessment of internal dose equivalents from the inhalation of radioactive aerosols. Several practices and environments studied include thermal arc cutting, grinding, sandblasting, and noble gas progeny. For physical analyses, cascade impactors, scanning electron microscopy with energy-dispersive x-ray analysis, inductively coupled plasma atomic emission spectrometry, and neutron activation analysis were applied. For chemical analyses, the solubility lung class was determined, in vitro, with the measurement of aerosol dissolution rates in simulated biological fluids. Results of these analyses were used to calculate the annual limit on intake, the derived air concentration, and committed dose equivalents for radiological protection against radioactive aerosols produced at Chin-Shan nuclear power plant.

Aerosols↗
PubMed1997

A computerized radioactive material inventory system using a commercially available database program.

An accurate and current radioactive materials inventory is essential for efficient control and use of radioactive material. In order to facilitate data entry, a computerized radioactive material inventory procedure has been developed using a commercially available database program. This system allows inventory records to be entered and updated quickly and efficiently with desired reports generated, without needing extensive computer training or programming skills.

Documentation↗
PubMed2002

A survey of background radiation dose rates and radioactivity in Tanzania.

Potential terrestrial sources of naturally occurring elevated radiation levels have been identified in Tanzania. Thus, efforts are currently being undertaken to create a natural radiation database, in the form of a radiation level map of natural radioactivity, to be used to assess the associated radiation risk to public and workers. Background radiation dose rate was determined with thermoluminescent dosimeters for 7 y (1993-1999) in five stations. The average background radiation dose rates for these stations were as follows: Tropical Pesticides Research Institute (TPRI) (102 +/- 7 nGy h(-1)), Same (98 +/- 2 nGy h(-1)), Namanga (98 +/- 5 nGy h(-1)), University of Dar Es Salaam (99 +/- 2 nGy h(-1)), and Kilimanjaro Christian Medical Center (121 +/- 3 nGy h(-1)). These stations were found convenient from an economic point of view since the project has no funds to cover wider and/or more remote areas in Tanzania. For the sake of comparison, similar measurements were made for the same period at Minjingu phosphate mine. The mine was one of the suspected areas with elevated levels of natural radioactivity. The radiation dose rate measured in this mine was about fourteen times higher (1,415 +/- 28 nGy h(-1)) than the average value obtained in northern Tanzania (98 nGy h(-1)). The high average activity levels of phosphate (5760 +/- 107 Bq kg(-1) for 261Ra, 497 +/- 5 Bq kg(-1) for 228Ra, 350 +/- 6 Bq kg(-1) for 228Th, and 280 +/- 5 Bq kg(-1) for 40K) and radiation dose rate recorded show that Minjingu phosphate mine has higher values than the highest radioactivity in phosphate compiled by the United Nations Scientific Committee on the Effect of Atomic Radiation. In view of these findings, a comprehensive risk-management strategy for reduction of radiation risk to the public and mine workers should be put in place. Efforts are currently being made to seek support to improve the background radiation database for subsequent assessment of radiation risk to miners and the societies in the vicinity of these mines in Tanzania.

Background Radiation↗
PubMed2005

Altered gene expression profiles by sodium/iodide symporter gene transfection in a human anaplastic thyroid carcinoma cell line using a radioactive complementary DNA microarray.

BACKGROUND: The sodium/iodide symporter (NIS) is a membrane glycoprotein that mediates active 131I uptake during the treatment of cancer of the thyroid gland and extrathyroidal tissues. NIS gene transfection, a gene-therapy modality, has been introduced in many types of cancer, such as prostate cancer and breast cancer, and has demonstrated a high potential for the treatment of non-thyroidal cancers. AIM: To investigate the pattern of NIS gene expression and provide evidence of its beneficial effects in human anaplastic cancer ARO cells by using a radioactive complementary DNA (cDNA) microarray. METHODS: For cDNA microarray data analysis, superimposed images and clustergrams were prepared from basic radioactivity data obtained using a phosphoimager system. Gene expression profiles were constructed using the Z-transformed values of genes related to cancer biology. RESULTS: Radioactive cDNA microarray studies showed that 11 genes were upregulated (Z ratio > 1.5) and 31 genes were downregulated (Z ratio < -1.5) in response to NIS gene transfection. Of these differentially expressed genes, 33% were related to cell proliferation and apoptosis. Moreover, NIS gene transfection into an anaplastic thyroid cancer cell line affected the expression of the protein tyrosine phosphatase (PTP) family and Ras oncogene family, including Ras, Rac and Rab. CONCLUSION: The identification of changes in the patterns of gene expression may provide a better understanding of the response of molecular mechanisms to NIS gene transfection.

Carcinoma↗
PubMed1986

Lung cancer: is the increasing incidence due to radioactive polonium in cigarettes?

This paper presents clinical, experimental, and epidemiologic evidence to help explain the rapidly increasing incidence of primary lung cancer, with recently observed reversal in leading cell type from squamous cell to adenocarcinoma. It postulates that this may be due to changes in modern cigarettes, with or without filters, which allow inhalation of increased amounts of radioactive lead and polonium and decreased amounts of benzopyrene. This hypothesis is based upon measurements of increased concentrations of radioactive polonium in the lungs of cigarette smokers, in modern tobaccos grown since 1950, and in high-phosphate fertilizers used for tobacco farming in industrialized countries. Critical support for this thesis is based upon experimental animal studies in which lung cancers that resemble adenocarcinomas are induced with as little as 15 rads of radioactive polonium, equal to one fifth the dosage inhaled by cigarette smokers who average two packs a day during a 25-year period.

Adenocarcinoma↗
PubMed2005

Measurements of radioactivity in books and calculations of resultant eye doses to readers.

Natural and fallout radioactivity in some book samples were measured with an HPGe detector coupled with a 4096 channel analyzer in order to estimate the radiation doses to readers' eyes from books. The radiation doses to a population at large due to the presence of radioactivity in the book are not significant. Thus, no radiation hazard occurs from the radioactivity content in the book. The estimated radiation doses to eyes were found to be below the maximum permissible dose to eyes recommended by ICRP.

Books↗