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PubMedDate not supplied

[The late sequelae of the action of irradiation during the cleanup of the aftermath of the Chernobyl catastrophe on the concentration of macro- and microelements in human blood serum].

The content of Cu, Fe, Zn, Mg, P, and S in the blood serum and its ultrafiltrate was studied by the inductively coupled argon plasma atomic emission spectrometry in eliminators of the accident at the Chernobyl Nuclear Power Station who worked in the accident zone in 1986-1987. Changes in the mineral equilibrium of the blood serum was expressed in elevated concentrations of the ultrafiltered Cu and S, increased Mg content in the serum, and decreased content of ultrafiltered Zn. The Fe concentration in the serum and ultrafiltrate did not differ from the control indices, thus suggesting balanced Fe transport, accumulation, and mobilization at a remote time after the radiation injury.

Humans↗
PubMed1982

Blood clearance of three radioactively labelled platinum complexes: cis-dichlorodiammine platinum II, cis, trans-dichlorodihydroxy-bis-(isopropylamine) platinum IV, and cis-dichloro-bis-cyclopropylamine platinum II, in patients with malignant disease.

The blood clearances of three platinum compounds, cis-dichlorodiammine platinum II (DDP), cis, trans-dichloro-dihydroxy-bis-(isopropylamine) platinum IV (CHIP), and cis-dichloro-bis-cyclopropylamine platinum II (CP), were determined in nine patients with malignant disease. The complexes were prepared using radioactive platinum (191Pt and 193Pt). A 10-mu Ci dose of each complex, containing the equivalent of 1-2 mg elemental platinum, was injected IV into groups of three patients. Serial blood and urine samples were collected over 72 h. No obvious difference was found between the three complexes for blood clearance, median t1/2a being 16.8 (range 11.2-23.5) min and median t1/2 beta 89 (range 63.7-127) h. The urinary excretion was greatest for CHIP, 60% of injected dose as against 42.6% for CP and 38.8% for DDP. Differences in renal excretion of DDP analogues could indicate potentially less nephrotoxic agents. The use of radioactive Pt will allow in vivo dynamic imaging of the distribution of platinum compounds in areas of interest.

Aged↗
PubMed2001

A mechanistic model for the uptake of waterborne strontium in the common carp (Cyprinus carpio L.).

The release of radioactive strontium to the environment is of concern due to the strong accumulation of this calcium resembling element in the bone and other tissues. To predict the effects of changes in environmental conditions on the uptake of Sr2+ and Ca2+ by freshwater fish, a Michaelis-Menten type model is introduced that accounts for the effects of chemical speciation, hydrogen ion activity, and metal ion competition. The uptake kinetics were characterized in vivo from short-term exposure experiments using the common carp (Cyprinus carpio) as the model organism. Fish were exposed to a wide range of waterborne Sr2+ (0.2-10,000 microM) and Ca2+ (10-10,000 microM) concentrations and water pH (5.0-8.5). Strontium uptake by the whole body of fish increased with increasing Sr2+ activity, displaying saturation kinetics, but decreased significantly with increasing Ca2+ and H+ activities in the water. Likewise, calcium uptake by the fish decreased with increasing Sr2+ and H+ activities in the water. The model fitted to the pooled data explains 97.5% of the variation in Sr2+ uptake and 86% in Ca2+ uptake over the wide range of exposure conditions and reveals that Sr2+ and Ca2+ inhibit each other completely competitively, while H+ inhibits the uptake of both metal ions in a partially noncompetitive way. This model can be used as a mechanistic tool to predict the uptake of these metals in carp under variable conditions.

Animals↗
PubMed1984

Determination of gold and platinum traces in biological materials as a part of a multi-element radiochemical activation analysis system.

For the analysis of human tissues for traces of gold and platinum--being used as constituents of therapeutic agents--a radiochemical neutron activation method has been developed. The radiochemical separation involves the selective removal of radioactive gold--formed by the reaction 197Au (n, gamma)198Au and the reaction 198Pt (n, gamma) 199Pt ---- 199Au --as small metallic nuggets . The determination of gold and platinum is carried out as a part of an automated multi-element radiochemical separation scheme, allowing the determination of about 20 additional trace elements, and thus giving the possibility to study interelement relations. The analytical characteristics of the determination are evaluated. Gold and platinum levels measured in Bowen's Kale, NBS Bovine Liver and NBS Orchard Leaves are presented. Values are shown for gold, platinum, and 20 other trace elements in various healthy and cancerous tissues from patients treated with cis-platin. (Cis-Diamminedichloroplatinum II).

Activation Analysis↗
PubMed2002

Trace metals and 210Po (210Pb) concentrations in mussels (Mytilus galloprovincialis) consumed at western Anatolia.

The mussels (Mytilus galloprovincialis) have been evaluated for their bioavailability as biomonitors of trace and toxic elements in coastal water of western Anatolia. The levels of Fe, Cu, Zn, Pb, Br and Sr in the edible part of mussels were determined using X-ray fluorescence method during the period of September 1999-July 2000. Distribution of 210Po and 210Pb activities were measured by radiometric methods and their ratios were calculated. The activity concentrations of 210Po and 210Pb were found to vary between 52 +/- 6-1,344 +/- 108 and 6 +/- 2-167 +/- 10 Bqkg(-1) dry wt, respectively. The highest values for 210Po and 210Pb were measured in Foca mussels and also observed the highest Fe, Zn and Br concentrations in the same species. 210Po/210Pb activity ratio were derived as between 3.1 and 25.0.

Animals↗
PubMed2003

Uncertainty in transport factors used to calculate historical dose from 131I releases at the Savannah River Site.

During the 1950's, atmospheric release of 131I was one of the largest contributors to offsite dose at the Savannah River Site. Computer models used to estimate offsite dose involve the use of many parameters with wide ranges of uncertainty. The overall uncertainty in dose can be estimated by propagating the uncertainty of each parameter through the model. A major component of the calculational model can be solved for a given release scenario and condensed into a transport factor, which, when multiplied by the air concentration (or deposition) and the appropriate dose conversion factor, can be used to estimate a specific pathway dose. Uncertainties are estimated for the period of 1955-1961 for all parameters contributing to the 131I transport factor for each pathway. The overall transport factor including all pathways has ranges characterized by maximum-to-minimum ratios (95% to 5%) of about 40. The parameter shown to have the greatest impact on the transport factor calculation was the fraction of elemental iodine released.

Air Pollutants, Radioactive↗
PubMed1977

Preparation of radioactive iodinated cholylhistamine for use in the radioimmunoassay of cholic acid.

A major handicap in the development of simple and accurate radioimmunoassay procedures for bile acids has been the lack of a radioactive standard of high specific activity. To provide such a compound, we first synthesized cholylhistamine using the carbodiimide reaction. The hypothesized structure was confirmed by elemental analysis, thin-layer chromatography, infrared and mass spectral analysis. The cholylhistamine was then iodinated with 125I, using the choloramine-T method. The 125I-cholylhistamine was bound by antisera raised against a cholic acid-bovine serum albumin conjugate. This procedure should prove useful in preparing radioactive conjugates for all of the bile acids.

Cholic Acids↗
PubMed2001

[Exhalation of I-131 after radioiodine therapy (RIT): time dependence and chemical form].

AIM: The change of both amount and chemical forms of radioiodine exhaled in the air of rooms with patients on the therapy ward should be investigated depending on radioactivity applied, time after application, and kind of thyroid disease. METHODS: The air of ward-rooms of 62 patients with thyroid carcinoma, Graves' Disease, and autonomy which received different therapy doses, was investigated with an portable constant air flow sampler. Different chemical iodine species (organic, elemental, aerosol bound) were collected during 8 hr in various filters until 3 days after application of the radioiodine capsule, according to their chemical form. The radioactivity in the filters was measured with a well counter on defined time points after application. RESULTS: The radioactivity exhaled was between 0.008 and 0.03% related to activity of radioiodine applied. The percentage of radioiodine exhaled related to the activity applied, differed significantly depending on disease and changed as follows: Grave's Disease > autonomy > carcinoma. The exhalation of radioiodine became stronger with increasing applied activities and showed an exponential decrease with time. The most part of radioiodine was present in organic bound form. This organic portion decreased with time in favour of the other iodine species. CONCLUSION: The degree of accumulation of radioiodine orally applied within thyroid seems to be in direct proportion to the extend of its exhalation. Further measurements directly in the breathing air of RIT-patients are necessary, in order to clarify the relationship between degree of thyroid uptake and quantity as well as chemical form of radioiodine exhaled.

Air Pollutants, Radioactive↗
PubMed2002

Radioactivity and heavy metal composition of Nigerian phosphate rocks: possible environmental implications.

Phosphate rock samples collected from the Dange Formation within the Sokoto basin were analyzed for trace element constituents using instrumental neutron activation analysis (INAA) and X-ray fluorescence analysis (XRFA) techniques, while natural activity concentrations due to 235U, 232Th, and 40K were determined by gamma-ray spectrometry. The analytical results show that the average concentrations of some toxic elements (As, Sb, Cr, and Zn) in phosphate rocks are not appreciably different from that in agricultural soils. However the U and Th contents are enriched significantly in comparison. The results were used to assess the environmental toxicity of heavy metals and radiation hazard attributable to the direct application of phosphate rock as fertilizer.

Agriculture↗
PubMed1993

[Positron-emission tomography (PET)--basic considerations].

A PET installation is a technically complex system composed essentially of two parts. The first consists in isotope production and synthesis of labeled biochemical compounds, the second in measuring the distribution of radioactivity in the body with the PET camera and the generation of image data. The specific advantage of PET lies on one hand in the use of positron emitters that are isotopes of ubiquitous elements in biologic matter, i.e. exact analogs of biomolecules can be produced and utilized and on the other hand quantification is possible. (= enable quantitative...?) Theoretically there are no limits for the synthesis of radioactive compounds and the method therefore provides unlimited test designs. The short half-life of the employed isotopes is advantageous for radioprotection reasons but the production of labeled compounds necessitates a cyclotron accelerator and a special laboratory for the handling of radioactive compounds rendering the production of the test substances relatively expensive. Measurements take place in a PET camera with a large number of coincidence detectors. The best available cameras have a spatial resolution of 5 mm in all three axes with an axial window of about 15 cm diameter. Evaluation of PET images is done in a qualitative way by superposition on anatomic images (CT, MRI) by image fusion. Quantitative determinations require elaborate computer modeling.

Cyclotrons↗
PubMed1976

A radioactive mercury vapor generating and exposing system for small scale animal experiments.

An apparatus is described for exposing small animals to high specific activity elemental mercury vapor. The vapor is generated by reduction of mercury chloride labelled with the 203HG isotope. The vapor is carried by a constant stream of air into the exposure chamber. The method has been used to expose rats or mice to constant air concentrations of mercury vapor in the range from 0.008 to 0.32 mg/m3. The specific activity of the mercuric chloride used in the study was approximately 1.8 mCi/mgHg. This is sufficiently high to allow measurement of tissue deposition of mercury after an exposure period of only 30 minutes.

Animals↗
PubMed1982

An in vitro system for measuring intrinsic dietary mineral exchangeability: alternative to intrinsic isotopic labeling.

The primary purpose for the in vitro system described here was to provide an alternative method to intrinsic isotopic labeling for determining exchangeability of intrinsic food mineral with extrinsic inorganic mineral or one of its isotopes. In this system, foods or food mixtures extrinsically tagged with an isotope of the mineral of interest are incubated successively in media simulating peptic or pancreatic digestion. Radioactivity and mineral measurements are made on a)the mixture before digestion and after b)peptic and c)successive peptic pancreatic (P-Pa) digestion. Exchangeability is determined by comparing the specific activity in the peptic and P-Pa digest supernatants to that in the mixture before digestion. In addition, determination of the total soluble mineral after P-Pa digestion provides a measurement of potential bioavailability. The procedure was tested for calcium (Ca) exchangeability and bioavailability from a number of foods and food combinations with 45Ca as the tracer. It could be used for any mineral, however, including non-nutrient or toxic elements. It is likely to be most useful in association with human studies carried out with extrinsic stable (non-radioactive) or short-lived radioactive isotopes that are unsuitable for intrinsic labeling.

Biological Availability↗
PubMedDate not supplied

Unique behavior of rubidium in mice under low oxygen atmosphere. Simultaneous tracing of Sc, Mn, Fe, Co, Zn, Se, Rb, Y, and Zr using off radioactive multitracer technique.

Relative tissue distributions of Sc, Mn, Fe, Co, Zn, Se, Rb, Y, and Zr tracers were studied in young mice housed under four different O2 atmospheres (10 percent, 20 percent, 80 percent, and 100 percent O2) using the radioactive multitracer technique developed at The Institute of Physical and Chemical Research (RIKEN). At 48 hr after injection of the multitracer, the tissue uptake rates were examined for 10 tissues (brain, cardiac muscle, lung, liver, spleen, pancreas, kidneys, skeletal muscle, bone, and blood) and expressed as the radioactivity percentage of the injected dose per gram of wet tissue (percent dose/g). Rubidium uptake rates for all soft tissues of mice housed under a 10 percent O2 atmosphere were found to be higher than those of the tissues of mice housed under the other three O2 atmospheres (20 percent, 80 percent, and 100 percent), but no difference was observed for the other elements (Sc, Mn, Fe, Co, Se, etc.) under any of the O2 atmospheres.

Animals↗
PubMed2000

Precise and accurate isotope ratio measurements by ICP-MS.

The precise and accurate determination of isotope ratios by inductively coupled plasma mass spectrometry (ICP-MS) and laser ablation ICP-MS (LA-ICP-MS) is important for quite different application fields (e.g. for isotope ratio measurements of stable isotopes in nature, especially for the investigation of isotope variation in nature or age dating, for determining isotope ratios of radiogenic elements in the nuclear industry, quality assurance of fuel material, for reprocessing plants, nuclear material accounting and radioactive waste control, for tracer experiments using stable isotopes or long-lived radionuclides in biological or medical studies). Thermal ionization mass spectrometry (TIMS), which used to be the dominant analytical technique for precise isotope ratio measurements, is being increasingly replaced for isotope ratio measurements by ICP-MS due to its excellent sensitivity, precision and good accuracy. Instrumental progress in ICP-MS was achieved by the introduction of the collision cell interface in order to dissociate many disturbing argon-based molecular ions, thermalize the ions and neutralize the disturbing argon ions of plasma gas (Ar+). The application of the collision cell in ICP-QMS results in a higher ion transmission, improved sensitivity and better precision of isotope ratio measurements compared to quadrupole ICP-MS without the collision cell [e.g., for 235U/238U approximately 1 (10 microg x L(-1) uranium) 0.07% relative standard deviation (RSD) vs. 0.2% RSD in short-term measurements (n = 5)]. A significant instrumental improvement for ICP-MS is the multicollector device (MC-ICP-MS) in order to obtain a better precision of isotope ratio measurements (with a precision of up to 0.002%, RSD). CE- and HPLC-ICP-MS are used for the separation of isobaric interferences of long-lived radionuclides and stable isotopes by determination of spallation nuclide abundances in an irradiated tantalum target.

Journal Article↗
PubMed1980

Transmitter-related retrograde labeling in the pigeon optic lobe: a high resolution autoradiographic study.

High resolution light microscopic and electron microscopic autoradiography in a restricted area of the pigeon subtectal nucleus isthmi, pars parvocellularis (Ipc) 30 min after onset of a tectal [3H]glycine injection shows labeling mainly of the following elements: neuronal perikarya, initial axon segments and dendrites. Rapid labeling of such intrinsic Ipc elements and not of synaptic terminals possibly of tectal origin strongly suggests a fast retrograde migration of radioactivity within Ipc-tectal neurons. Fixation experiments indicate a soluble nature of this radioactive material. This type of retrograde labeling in the glycinergic Ipc-tectal pathway seems to be related to the transmitter specificity of the system.

Animals↗
PubMed2005

Direct evidence for As as a Zn-site impurity in ZnO.

Arsenic has been reported in the literature as one of the few p-type dopants in the technologically promising II-VI semiconductor ZnO. However, there is an ongoing debate whether the p-type character is due to As simply replacing O atoms or to the formation of more complicated defect complexes, possibly involving As on Zn sites. We have determined the lattice location of implanted As in ZnO by means of conversion-electron emission channeling from radioactive (73)As. In contrast to what one might expect from its nature as a group V element, we find that As does not occupy substitutional O sites but in its large majority substitutional Zn sites. Arsenic in ZnO (and probably also in GaN) is thus an interesting example for an impurity in a semiconductor where the major impurity lattice site is determined by atomic size and electronegativity rather than its position in the periodic system.

Journal Article↗
PubMed1965

Polonium-210 analyses of vegetables, cured and uncured tobacco, and associated soils.

Analysis of the edible portion of vegetables and samples of green leaf tobacco failed to show polonium-210. The cured samples of leaf tobacco and the soils that were analyzed all contained small quantities of the element. Muck soils contained three times as much Po(210) as did mineral soils. Solutions used commonly to extract "available" forms of many mineral elements failed to extract a detectable amount of Po(2l0). Indications are that Po(210) or its radioactive precursors are not taken up from the soil directly by plant roots but rather by sorption in dead, moist plant materials at the atmosphere-plant interface.

In Vitro Techniques↗