PubMed Health⌕ Search

SEARCH · PubMed Health

Results for “Elements, Radioactive”

Explore indexed PubMed citations for clinical trials, systematic reviews and public health research. Read source abstracts and follow each citation to its original PubMed record.

Quote a phrase for an exact phrase match. Source license links do not imply unrestricted reuse.

At least 325 records · Page 18Linked to original sources
PubMed2003

Anomalous 235U/238U ratios and metal elements detected in the black rain from the Hiroshima A-bomb.

Contents of black rain from the A-bomb are important to clarify the health and environmental hazard caused by nuclear warfare. We analyzed the only existing physical remains of the black rain from Hiroshima A-bomb (Little Boy), a plastered wall with black streaks. Excess 137Cs and anomalous 235U/238U ratios detected in the black residues on the wall confirmed that the black streaks on the wall originated from Little Boy. The results also showed that excess 235U could be used as a fingerprint to clarify the distribution of materials discharged from Little Boy into the environment. High concentrations of lead and zinc, which may have caused a degree of heavy metal pollution in the area where the rain fell, were also detected in the black rain sample.

Environmental Exposure↗
PubMed1995

In vitro effect of cyclophosphamide on the binding of radiopharmaceuticals (99mTcO4- and 99mTc-MDP) to blood elements.

Sodium pertechnetate (99mTcO4-) and many 99mTc-products are the radiopharmaceuticals most frequently used in nuclear medicine. Using an in vitro model, we evaluated the effect of cyclophosphamide on percent radioactivity of 99mTcO4- and methylenediphosphonic acid (99mTc-MDP) bound to isolated blood elements. Blood samples were incubated with the two radiopharmaceuticals, plasma and blood cells were separated and precipitated, and soluble and insoluble fractions were separated. To evaluate the effect of cyclophosphamide, blood was incubated with this drug 1 h prior to the addition of the radiopharmaceuticals. The fraction of 99mTcO4- radioactivity was slightly higher in plasma (61.2 to 53.8%) than in blood cells (38.8 to 46.2%) up to 6 h and cyclophosphamide did not interfere with this distribution. The amount of 99mTc-MDP radioactivity was higher in plasma (91.1 to 87.2%) than in blood cells (8.9 to 12.8%) up to 24 h and cyclophosphamide did not modify it. The binding of 99mTcO4- to the insoluble fraction of plasma (4.9 to 6.1%) was low and cyclophosphamide did not interfere with it up to 6 h, but a small blockade (9.8 to 4.8%) was observed at 24 h. From 3 h on, cyclophosphamide slightly inhibited 99mTcO4- binding to blood cells (23.1 to 16.6%) and increased it at 24 h (31.2 to 14.3%). Cyclophosphamide did not alter 99mTc-MDP binding to the insoluble fraction of blood cells and slightly decreased 99mTc-MDP binding to the insoluble fraction of plasma (29.8 to 23.6%) up to 6 h.(ABSTRACT TRUNCATED AT 250 WORDS)

Alkylating Agents↗
PubMedDate not supplied

[The vitamin and trace element status of the personnel of the Chernobyl Atomic Electric Power Station and of preschool children in the city of Slavutich].

Supply of the Chernobyl NPP staff and Slavutich children with vitamins and minerals has been examined in spring 1992. From 43 to 100% of people have moderate deficiency of vitamin C, B1, B2, B6 and folic acid, 6-61%--deep deficiency of these nutrients. Most of the people have insufficient supply with vitamins in the form of polyhypovitaminosis, i.e. combined deficiency of ascorbic acid and of 2 or 3 vitamins of the B group. Deficiency of 2 vitamins was found in 20% of adults of 3 vitamins in 37%, of 4 vitamins in 29% and of 1 vitamin in 10% of adults. Only 4% of examined adults are sufficiently supplied with all vitamins and none of children. Deficiency of 1 vitamin was found in 11% of children, of 2 vitamins in 15%, of 3 vitamins in 17%, of 4 vitamins in 35%, of 5 vitamins in 20% and of 6 vitamins in 2% of children. Supply of children with all vitamins has been improved when they received combined vitamin-mineral preparation "Duovit" for one month. Universal prophylactic vitaminization by means of administration of ascorbic acid and polyvitamin preparations in doses corresponding to the daily physiological requirement should be recommended as the most reliable, effective and economical measure aimed to improve supply of the population with vitamins.

Adult↗
PubMed1976

Transport of RNA along the optic pathway of the chick: an autoradiographic study.

Autoradiograms of the optic tectum were made 8 days after monocular injection of 3H-uridine in 3 day-old chicks. Electron microscopic analysis of grain density over morphological structures in various layers of the optic tectum contralateral to the injected eye, was carried out. This revealed that the highest concentration of labeled RNA was within the axons of the more superficial layers of the tectum. A lesser density of grains was observed over glial cells, neuronal perikarya and dendrites. In addition, the bulk of the total grains counted were over axons. In lower tectal layers, radioactivity was predominantly over unmyelinated axons and glial elements. High molecular weight RNA appears to be transported within the axons of the optic nerve toward their terminations which are largely in the outer layer of the optic tract.

Animals↗
PubMed2005

Assessment of actinide mass embedded in large concrete waste packages by photon interrogation and photofission.

This paper describes a method based on photofission developed in our laboratory to characterize in depth large waste packages. The method consists in using photons of high-energy (Bremsstrahlung radiation) in order to induce reactions of photofission on the heavy nuclei present in the wastes. The measurement of the delayed neutrons allows quantifying the actinides in the wastes. We present the first results of measurement performed with a concrete mock-up of 870l and two real waste packages.

Actinoid Series Elements↗
PubMed1998

Temporal changes of 210Po in temperate coastal waters.

The temporal variation of Polonium-210 (210Po) was examined in coastal sea water, the mussel Mytilus edulis, the winkle Littorina littorea and green alga Ulva lactuca in order to investigate the entry of 210Po into the marine food chain. More than 99% of 210Po in the water column occurred in the particulate phase. Dissolved 210Po concentrations peaked during the spring phytoplankton bloom and it is suggested this is related to preferential scavenging of 210Po by the increased numbers of bacteria, viruses and small dissolved particulates. Changes in L. littorea 210Po specific activity are thought not to be related to food, but to a drop in body weight following spawning. Much of the 210Po accumulated by M. edulis was located in the digestive gland. The specific activity of 210Po in the digestive gland of M. edulis was shown to be strongly correlated with changes in sea water suspended particulate specific activity. Examination of other trace metal (Ag, Al, As, Ca, Cd, Cr, Co, Cu, Fe, Hg, K, Mg, Mn, Na, Ni, Sb, Se, Sn and Zn) variations in the digestive gland revealed that class B and borderline metals had a strong positive correlation with 210Po. On-going work is investigating whether the accumulation and loss of 210Po is affected by the presence of metallothioneins.

Animals↗
PubMed2001

Heavy metal pollution of some Danube Delta lacustrine sediments studied by neutron activation analysis.

Using neutron activation analysis and radiometric measurements, the vertical distribution of six possible pollutant elements (Zn, Cr, Co, As, Sb and Br), two trace elements of natural origin (Sc and Hf) and radioactive 137Cs were determined in three lakes, Furtuna, Lung and Mesteru, located in an active sedimentary zone of the Danube Delta. The accumulation rate of recent sediments was estimated from radiocesium profiles. Zn, As, Sb and Br were identified as possible pollutants. The vertical profiles of their concentrations reflect recent historic inputs, showing a gradual increase until around 1990, followed by a continuous decrease.

Cesium Radioisotopes↗
PubMed1999

Prediction of the relative activity levels of the actinides in a fallout from a nuclear reactor accident.

The relative activities of the actinides that can be expected in a fresh fallout from a nuclear reactor (BWR, PWR, RBMK) accident have been estimated from fuel composition calculations. The results can be used to (1) adapt analytical methods to better suit emergency situations, (2) estimate the activity levels of radionuclides not measured and (3) estimate the relative activities of nuclides in unresolved alpha-peaks. The latter two can be applied to investigations concerning the Chernobyl fallout, in addition to emergency situations.

Actinoid Series Elements↗
PubMed1989

Chernobyl source term, atmospheric dispersion, and dose estimation.

The Chernobyl source term available for long-range transport was estimated by integration of radiological measurements with atmospheric dispersion modeling and by reactor core radionuclide inventory estimation in conjunction with WASH-1400 release fractions associated with specific chemical groups. These analyses indicated that essentially all of the noble gases, 60% of the radioiodines, 40% of the radiocesium, 10% of the tellurium, and about 1% or less of the more refractory elements were released. Atmospheric dispersion modeling of the radioactive cloud over the Northern Hemisphere revealed that the cloud became segmented during the first day, with the lower section heading toward Scandinavia and the upper part heading in a southeasterly direction with subsequent transport across Asia to Japan, the North Pacific, and the west coast of North America. The inhalation doses due to direct cloud exposure were estimated to exceed 10 mGy near the Chernobyl area, to range between 0.1 and 0.001 mGy within most of Europe, and to be generally less than 0.00001 mGy within the United States. The Chernobyl source term was several orders of magnitude greater than those associated with the Windscale and TMI reactor accidents. However, the 137Cs from the Chernobyl event is about 6% of that released by the U.S. and U.S.S.R. atmospheric nuclear weapon tests, while the 131I and 90Sr released by the Chernobyl accident was only about 0.1% of that released by the weapon tests.

Accidents↗
PubMed1992

Transcriptional activation of human (2'-5')oligoadenylate synthetase gene expression by the phorbol ester 12-O-tetradecanoyl-phorbol 13-acetate in type-I-interferon-treated HL-60 and HeLa cells.

(2'-5')Oligoadenylate [(2'-5')(A)n] synthetase is a key enzyme in the interferon-elicited antiviral response whose controlled expression in interferon-treated cells has been only partially elucidated. In this investigation, we have compared the modulation of the (2'-5')(A)n synthetase gene by interferon alone and by the combination of interferon and a second cellular effector, 12-O-tetradecanoyl-phorbol 13-acetate (TPA). Although TPA alone had no effect on (2'-5')(A)n synthetase, it potentiated the induction of (2'-5')(A)n of synthetase by interferon in HL-60 and HeLa cells by increasing content of its mRNA and an immunoreactive 40-kDa isoenzyme. Since TPA activates protein kinase C (PKC), other PKC-activating phorbol-ester analogues were tested and found to be effective, whereas the PKC inhibitor staurosporine reduced the potentiative activity of TPA. By using the (2'-5')(A)n synthetase gene promoter linked to a reporter gene, chloramphenicol acetyltransferase (CAT), TPA and interferon were found to result in a doubling of CAT activity compared to cells treated with interferon alone. Moreover, when nuclear extracts prepared from control cells or cells treated with TPA and interferon (IFN), separately or together, were incubated with radioactively labeled oligodeoxynucleotides containing the interferon-responsive element (IRE), TPA was shown to down-regulate an IFN-inducible IRE/protein complex. These data further suggest that TPA regulates (2'-5')(A)n synthetase gene expression at the level of transcription.

2',5'-Oligoadenylate Synthetase↗
PubMed2000

Interaction of the Neurospora crassa heat shock factor with the heat shock element during heat shock and different developmental stages.

The interaction of the heat shock factor (HSF) with the heat shock element (HSE) was determined by a non-radioactive electrophoretic mobility shift assay, in order to analyze HSF regulation in Neurospora crassa. HSF binds to HSE under normal, non-stress conditions and is thus constitutively trimerized. Upon heat shock, the HSF-HSE complex shows a retarded mobility. This was also observed in Saccharomyces cerevisiae, where this mobility shift was shown to be due to HSF phosphorylation [Sorger and Pelham (1988) Cell 54, 855-864]. In N. crassa, HSE-dependent electrophoretic mobility shift is temperature- and time-dependent. Under normal growth conditions, the HSF is located in the cytoplasm as well as in the nucleus. In germinating conidia the HSF shows a retarded mobility typical for heat shock even at normal growth temperatures. No HSF-dependent mobility shift was detectable in aerial hyphae.

DNA-Binding Proteins↗
PubMedDate not supplied

[Metabolic disorders in digestive and hepatobiliary pathology in those who worked in the cleanup of the aftermath of the accident at the Chernobyl Atomic Electric Power Station].

A clinical observation over 57 liquidators of the Chernobyl accident aftermath (ChAAL) with associated diseases of the digestive and hepato-biliary system revealed abnormalities in blood enzymic activity, presenting as elevation of, in particular, alanine aminotransferase as well as of asparagine aminotransferase, gamma-glutaminetranspeptidase, alkaline phosphatase, lactate dehydrogenase, and of blood mineral composition at the expense of an increase in certain minerals. Disturbances in underlying process of bodily metabolism promote the development and association of erosive and ulcerous lesions of the stomach and duodenum with chronic noncalculous cholecystitis, persistent hepatitis in ChAAL.

Adult↗
PubMed2000

The impact of stent design and delivery upon the long-term efficacy of radioisotope stents.

Both gamma and beta irradiation delivered via a radioactive catheter-based line source have been shown to have efficacy in reducing restenosis. However, these catheter-based treatments have some limitations, including the safety of handling sources ranging from 30 mCi to 500 mCi. Alternatively, one could use a stent as the platform for local radiation delivery as a means to prevent restenosis. Experimental studies have demonstrated that stents ion implanted with the b-particle emitter 32P can reduce neointima formation. Clinical evaluation of the radioisotope stent began in the fall of 1996. Dose escalation studies have now been completed in approximately 250 patients with 32P, b-particle emitting stents ranging from 0.5 microCi to 24 microCi. Overall, these feasibility trials have demonstrated a clear, dose-dependent reduction of neointimal hyperplasia within the stent structure, but with an unanticipated finding of a relatively high incidence of restenosis at the stent margins. The purpose of this paper is to review the current status of radioactive stents, with an emphasis on the key elements of stent design and stent delivery that could impact the long-term efficacy of this device.

Brachytherapy↗
PubMed1992

Significance of secondary ion mass spectrometry microscopy for technetium-99m mapping in leukocytes.

Secondary ion mass spectrometry (SIMS) microscopy is the only method potentially capable of mapping all the elements in the periodic table including stable and radioactive isotopes. We used this method to study 99mTc distribution by detecting and localizing of 99Tc, a daughter product which has the same mass and the same chemical properties. It was combined with albumin macroaggregates or with Hexamethylpropylene-amine oxime (HMPAO) in leukocytes. The efficiency of 99Tc ionization under Cs+ bombardment was higher than with an O2+ beam. By using high mass resolution we succeeded in detecting and localizing 99Tc in cell sections by eliminating polyatomic ions that arise from this biological matrix. The 99Tc specific signal was obtained with a mass resolution of 2000 for labeled albumin macroaggregates, and 5000 for HMPAO-labeled leukocytes. In the latter, the labeling varied from one cell to another and 99Tc was present in both the nucleus and the cytoplasm. The results indicate that SIMS microscopy can provide new insights into 99mTc dosimetry.

Humans↗
PubMedDate not supplied

[Oxygen-dependent processes in the irradiated organism].

Interaction of oxygen with the X-rayed tissues, chemical substances and elements is one of the main mechanism of radioactive damage. Radiosensibilization by oxygen (oxygen effect) is most highly exhibited under the action of high and moderate radiation doses. However there is only scanty investigations and information about oxygen-dependent processes under low doses of internal and external radiation due to their intricate character. Radiation exerts also a great influence on oxygen metabolism and oxygen consumption level. Oxygen takes active part in post-radiation recovery both at the level of molecules, organelles, cells, tissues, organs and the organism on the whole. The partial pressure of oxygen and its content have a great influence on the action of radioprotectors, anti-radiation therapy and healing methods. Long-term influence of hypoxia at high altitude evokes adaptation changes, stimulates recovery processes in an X-rayed organism, increases resistance to radiation and other noxious factors.

Animals↗
PubMed1992

Zirconium. An abnormal trace element in biology.

The action of Zirconium (Zr) on biological systems presents an enigma. It is ubiquitous, being present in nature in amounts higher than most trace elements. It is taken up by plants from soil and water and accumulated in certain tissues. The entry into animal systems in vivo is related to the mode of exposure and the concentration in the surrounding environment. Retention is initially in soft tissues and then slowly in the bone. The metal is able to cross the blood brain-barrier and is deposited in the brain and the placental barrier to enter milk. The daily human uptake has been known to be as high as 125 mg. The level of toxicity has been found to be moderately low, both in histological and cytological studies. The toxic effects induced by very high concentrations are nonspecific in nature. Despite the presence and retention in relatively high quantities in biological systems, Zr has not yet been associated with any specific metabolic function. Very little information is available about its interaction with the compounds of the genetical systems, such as nucleic acids. Apparently, the metal is neither an essential nor toxic element in the conventional sense. However, the increasing exposure to this element through its increasing use in new materials and following radioactive fallout, has increased the importance of the study of its effects on living organisms. The tetravalent nature of the ionic state and the high stability of the compounds formed are important factors that need to be considered, as also the accumulation of this element in the brain, reminiscent of the relationship between Al3+ and Alzheimer's disease.

Animals↗