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 217 records · Page 12Linked to original sources

Uptake of trace elements by rice plants inoculated with Pyricularia oryzae.

The ability of rice plants inoculated with Pyricularia oryzae (P. oryzae) to take up trace elements was studied by the radioactive multitracer technique. Among various elements, only Mn, Co, Zn, Se, Rb, Sr, Tc, and Re were found to be transferred to rice shoots from soil. The concentrations of essential elements, Mn and Zn, in the shoots of rice plants inoculated with P. oryzae were slightly higher than those in the control plant shoots, while Se, Rb, Tc, and Re showed almost the same concentrations for both the shoots.

Ascomycota↗

59Fe is retained from an elemental 59Fe powder supplement without effects on 65Zinc, 47Calcium and 67Copper in young pigs.

In vivo counting with the use of a germanium detector evaluated the retention of an elemental 59Fe powder supplement while measuring potential interactions with zinc, calcium and copper. Effects of dietary iron and zinc on in vivo retentions of 59Fe, 65Zn, 67Cu and 47Ca were studied in young pigs. In Experiment 1, 4-d-old piglets fed a cereal-based diet were randomly assigned to one of four treatment groups (2 x 2 factorial arrangement, n = 5 per group). Variables were dietary iron source (either elemental iron or FeSO4, each at 100 mg iron/kg diet) and the dosage form of radioactive iron (either elemental 59Fe powder or 59FeSO4). Experiment 2 (2 x 3 factorial arrangement) was performed using two levels of iron (100 and 200 mg/kg, as elemental iron) and three levels of zinc (25, 50 and 100 mg/kg). Piglets were also dosed with 47Ca, 65Zn and 67Cu; all radioisotopes were measured for 8 d. Apparent absorption of elemental 59Fe powder was 13 +/- 1%, whereas 59Fe sulfate was significantly (P < 0.05) higher at 26 +/- 1%. The FeSO4 diet decreased 65Zn retention in Experiment 1, in contrast to the elemental iron diet, which did not have this effect in either experiment. Apparent 65Zn absorption averaged 44 +/- 2, 35 +/- 1 and 27 +/- 2% for the three levels of zinc (25, 50 and 100 mg/kg), respectively. Retention of 47Ca was not affected by dietary iron or zinc; retention of 67Cu was not affected by dietary iron. The data demonstrate good bioavailability of elemental iron without effects on zinc, copper and calcium.

Animals↗

Pulmonary toxicity of stable and radioactive lanthanides.

The pulmonary toxicity of inhaled lanthanides has been the subject of debate. In question have been the relative contributions of radioactive vs. stable elements in the development of lanthanide-associated progressive pulmonary interstitial fibrosis. The central question of this debate is: Are lanthanide dusts that are devoid of radioactive contaminants capable of producing progressive pulmonary disease, or are lanthanide-induced lesions more appropriately termed "benign pneumoconioses"? This paper examines the epidemiologic and experimental record in order to answer the above question. It is clear from the available data that significant pathogenic potential of inhaled lanthanides exists and is related to the type and physicochemical form of the material inhaled and to the dose and duration of exposure. Contamination of the dust with radioactive materials may accelerate and enhance the pathologic response, depending on the form and dose of radioactivity encountered. Nevertheless, there is little evidence to suggest that the level of radioactive contamination of occupationally encountered lanthanide dusts is sufficient to be included as a risk factor for pulmonary disease. Thus, the pulmonary syndrome induced by stable rare earths includes progressive pulmonary fibrosis and should not be referred to as "benign pneumoconiosis."

Administration, Inhalation↗

Radioactivity distribution in some Permian sediments from the Iratí and Corumbataí Formations of the Paraná Basin, Southeastern Brazil.

In the city of Limeira, southeastern Brazil, an important exposure of Permian sediments of the Paraná basin was revealed by an open pit mine that exploits limestone for production of soil correction compounds and raw materials for the ceramic industry. The radioactivity of these sediments was investigated in some detail and the results provided a general view of the vertical distributions of uranium, thorium and potassium concentrations and of the element ratios U/K, U/Th and Th/K. In general, the concentrations of the main natural radioactive elements are low, with uranium being enriched in some limestone and shale levels. In addition the results showed that the 238U series is in radioactive disequilibrium in many of the analyzed samples. Although the origin of the observed disequilibrium has not been investigated, the results suggest that it is due to weathering processes and water interaction with the rock matrix.

Brazil↗

[The kinetics of accumulation and elimination of the antitumor preparation tomizine-35 S].

On rats with sarcoma M-1 the peculiarities of accumulation and elimination of the folic acid antagonist-pyrimido (4,5-b), (1,4) thiazinon-35S, called "thomizine", have been studied. In travenous injection of thomizine-35S with the activity of 5 muc per animal the highest initial concentration of radioactivity was observed 5-15 minutes after the injection. While decreasing, the radioactivity absorption coefficients in organs were distributed as follows: the kidneys, pancreas, organs of the endocrinous system, lymph nodes, the stomach, liver, small intestine, brain. Thomizine-35S accumulation in rat organs proceeded not only on account of its intake with blood but also due to penetration and subsequent deposition in structural tissue elements. Lessening of radioactivity in the organism of rats was dependent exponentially. Elimination of the drug was realized mainly via the kidneys. 89 per cent of the absorbed radioactivity was eliminated from the organism with a period of semielimination of 1 hour, 11 per cent - with a period of semielimination of 36 hours.

Animals↗

[Metallic trace elements--A1, Cd, Cu, Fe--in solutions of 111InCl3: determination by flameless atomic absorption and results in 111In-radiolabeling of monoclonal antibodies].

Determination of trace elements in 111InCl3 solution have been carried out by flameless atomic absorption spectrometry. Five successive batches from three European companies have been analysed. The means of measured values range from 4560 to 6930 micrograms L-1 for aluminium, 131 to 874 for cadmium, 49 to 300 for copper, 387 to 698 for iron. Using two molar ration indexes, trivalent metallic traces have been compared to theoretical 111In content. The trace elements largely exceed radioactive material. As Fe and In have similar chemical properties, it results in low specific activity of radioactive complex when labeling monoclonal antibodies by 111In. Using a mathematical model, a detrimental effect of Fe trace levels has been studied.

Aluminum↗

Relation between the location of elements in the periodic table and various organ-uptake rates.

Fifty four elements and 65 radioactive compounds were examined to determine the organ uptake rates for rats 3, 24 and 48 h after i.v. injection of these compounds. They were prepared as carrier free nuclides, or containing a small amount of stable nuclide. Generally speaking, behaviors of K, Rb, Cs and Tl in all the organs were very similar to one another, but they differed from that of Na. Bivalent hard acids were avidly taken up into bone; therefore, uptake rates in soft tissues were very small. Hard acids of tri-, quadri- and pentavalence which were taken up into the soft tissue organs decreased more slowly from these organs than other ions. Soft acids such as Hg2+ were bound very firmly to the component in the kidney. Anions (with few exceptions), GeCl4 and SbCl3 were rapidly excreted in urine, so that the uptake rates in organs were low.

Animals↗

Radionuclides and trace metals in eastern Mediterranean Sea algae.

Three types of sea alga distributed along the Syrian coast have been collected and analyzed for radioactivity and trace elements. Results have shown that (137)Cs concentrations in all the analyzed sample were relatively low (less than 1.2 Bq kg(-1) dry weight) while the levels of naturally occurring radionuclides, such as (210)Po and (210)Pb, were found to be high in most samples; the highest observed value (27.43 Bq kg(-1) dry weight) for (210)Po being in the red Jania longifurca alga. In addition, most brown alga species were also found to accumulate (210)Po, which indicates their selectivity to this isotope. On the other hand, brown alga (Cystoseira and Sargassum Vulgare) have shown a clear selectivity for some trace metals such as Cr, As, Cu and Co, this selectivity may encourage their use as biomonitor for pollution by trace metals. Moreover, the red alga species were found to contain the highest levels of Mg while the brown alga species were found to concentrate Fe, Mn, Na and K and nonmetals such as Cl, I and Br.

Cesium Radioisotopes↗

Long-term increase of Sp-1 transcription factors in the hippocampus after kainic acid treatment.

Systemic administration of kainic acid (KA), a glutamate receptor agonist, causes robust seizures and has been used as an excellent rodent model for human temporal lobe epilepsy. Recently, we have demonstrated that a single injection of KA increases the steady-state levels of proenkephalin (PENK) mRNA in the rat hippocampus for at least one year. However, the molecular mechanisms underlying this long-term increase in PENK mRNA levels have not been clearly defined. To determine the possible involvement of the Sp-1 transcription factors in this regulation, electrophoresis mobility-shift assays were used to study the expression of Sp-1 factors in the hippocampus after KA treatment. The results showed that there are long-lasting increases in Sp-1 DNA-binding activity. The Sp-1 DNA-binding complexes were only competed by the non-radioactive Sp-1 element and not by ENKCRE2, AP-1 or CRE elements, indicating the specificity of Sp-1 DNA-binding activity. Since the expression of Sp-1 parallels the time course of long-lasting increase in the expression of PENK mRNA and mossy fiber sprouting after KA treatment, we hypothesize that the increase in Sp-1 activity may be associated with the long-term changes in the plasticity of hippocampal function after KA-induced seizures.

Animals↗