SEARCH · PubMed Health

Results for “RADIOACTIVITY”

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 37 records · Page 2Linked to original sources

PubMed2001

Tissue distribution of radioactivity following intranasal administration of radioactive microspheres.

The aim of this study was to increase understanding of the kinetics of microparticle distribution and elimination following intranasal application. To do this we investigated the in-vivo distribution of radioactivity following intranasal instillation of scandium-46 labelled styrene-divinyl benzene 7-microm-diameter microspheres. Groups of BALB/c mice received 0.250 mg (47.5 kBq) particles suspended in either 50-microL or 10-microL volumes of phosphate buffered saline. The in-vivo distribution of radioactivity was influenced by the volume of liquid that was used to instil the microsphere suspension. Comparatively large (50 microL) administration vehicle volumes resulted in substantial bronchopulmonary deposition (approximately 50% of administered dose). Intranasal instillation of microspheres suspended in 10-microL volumes tended to restrict particle deposition initially to the nasal cavity. For both administration vehicle volumes tested, the radioactivity per unit mass of excised nasal-associated lymphoid tissue (NALT) was found to be consistently elevated relative to other tissues. This corroborates the findings of other workers who have previously identified NALT as an active site of microparticle accumulation following intranasal application. Elimination via the alimentary canal was the principal fate of intranasally applied radiolabelled material. No significant concentration of radioactivity within excised gut-associated lymphoid tissue (GALT) (Peyer's patches) was noted. At latter time points we observed, in mice that received the 50-microL volume particle suspension nasally, accumulation of potentially relevant quantities of radioactivity in the liver (0.3% after 576 h) and spleen (0.04% after 576 h). Thus, our data corroborate the notion that epithelial membranes in the lung are probably less exclusive to the entry of microparticulates into systemic compartments than are those mucosae in the gastrointestinal tract or nasopharynx. This effect may contribute to the effectiveness of pulmonary delivered antigen-loaded microparticles as humoral immunogens.

Administration, Intranasal↗

PubMed1987

Detection of DNA viruses by radioactive and non radioactive DNA probes: application to African swine fever virus.

A molecular hybridization technique using radioactive and non radioactive DNA probes, has been used to detect ASFV DNA immobilized on nitrocellulose paper. It is based on the use of plasmid pRPEL-2 as a hybridization probe. This plasmid contain the H-ClaI DNA fragment (size 5.6 Kbp) from the Spain-70 strain of ASFV. The sensitivity of detection using radioactive 32P-probes (specific activity about 2 X 10(8) cpm per microgram) was about 20 pg of viral DNA. The 32P-pRPEL-2 DNA probe can detect about 100 infected MS cells and failed to hybridize to DNA from HSV-2, MS cells or salmon sperm. The sensitivity with non radioactive probes was about 4 ng of viral DNA for a sulfonated DNA probe and 400 pg for a biotinylated DNA probe. The efficiency of DNA fixation to the filter, the effect of EDTA and of ultrasonic treatment of the sample were also investigated.

African Swine Fever Virus↗

PubMed1975

[Resorption and incorporation of radioactive-labeled amino acids during administration of various protein carriers in rats. 3. Uptake of radioactivity by blood plasma, liver and muscular tissue and incorporation into tissue proteins after intragastric administration of 14C-leucine and 3H-glycine].

Growing male rats received diets of varying biological value (protein sources: powdered whole egg (V); fish meal (F); yeast (H); gelatine (G); protein-free diet (e)) for a 14-day feeding period. Subsequently, 14C leucine and 3H glycine were administered intragastrically. The level of uptake of 14C and 3H radioactivity into blood plasma, liver and muscular tissue and the rate of incorporation of the radioactive tracers into the proteins of these tissues was examined. A negative correlation was found to exist between the incorporation of radioactivity into liver proteins and the biological value of dietary proteins, the former being mainly dependent on the level of incorporation into the liver. For muscular proteins the rate of incorporation decreases with the decreasing biological value of the dietary proteins. This may be attributed to the fact that with poor protein nutrition the rate of protein synthesis in the skeletal muscles is also reduced. Comparative studies on the specific 14C radioactivity from free leucine made in the group on the protein-free diet and in the group receiving the whole egg diet showed that the leucine pool of the skeletal muscles was markedly redueced in animals fed a protein-deficient diet while the leucine pool in the liver remained comparatively constant.

Animal Nutritional Physiological Phenomena↗

PubMed1989

Radioactive metal complexes with affinity for tumors. II. Biodistribution of radioactivity in cellular and subcellular fractions of tumor tissues.

The 99mTc and 57Co complexes of ethylenediamine-N,N-diacetic acid (EDDA) are accumulated in tumor tissue. The complexes and related radioactive compounds were administered to experimental animals bearing Ehrlich tumor, and the blood, tumor, abscess, and other tissues were separated, fractionated and analyzed. In blood, the EDDA complexes of 99mTc and 57Co were in dialyzable forms, whereas other tumor-nonlocalizing compounds were in undialyzable or protein-bound forms. The tumor/blood and tumor/muscle ratios of the radioactivity showed that the complexes had the high affinity for tumor tissues. Density gradient centrifugation analysis of the ascites tumor tissues showed that a significant amount of the radioactivity of the complexes was present in tumor cells. Subcellular fractionation of solid tumor tissue showed that the radioactivity was present in nuclear fraction.

Animals↗

PubMed1996

Comparison of a radioactive and non-radioactive method for sequencing foot and mouth disease virus isolates.

The authors compare the radioactive method of detecting foot and mouth disease virus sequence products with a non-radioactive, silver stain sequencing method. The latter was found to compare favourably to the radioactive technique for detecting such products. The silver stain sequencing method was simple and did not require expensive specialised equipment. This new approach will be particularly useful in developing countries, since the method does not depend on the availability of fresh radioactive isotopes and is also safer and considerably cheaper.

Animals↗

PubMed2001

Separation of critical radioactive and non-radioactive species from aqueous waste streams.

The separation of radioactive and non-radioactive species from the simulated DOE neutralized current acid waste (NCAW) stream was studied. Cation and anion species were referred to their possible basic compounds, and divided into seven groups (nitrate, phosphate, sulfate, fluoride, nitrite, carbonate, and hydroxide). The nitrate group (the major anion in the DOE waste streams) contains several cations species, while the rest of the groups are only in the form of sodium. The precipitation measurements were conducted in three experimental stages. In the first stage, the precipitation of sodium sulfate, sodium phosphate, sodium-sulfate-phosphate, and aluminum nitrate systems were studied using isopropylamine (IPA) as a precipitation solvent. The objectives of this stage were to evaluate the precipitation ability of IPA in precipitating these compounds individually, and to validate the consistency of the analytical instruments and the employed experimental procedure. Tests performed on the acquired data indicated a high level of experimental consistency. The removal of phosphate, sulfate and aluminum were very high. In the second stage, the precipitation studies were conducted on the: (1) nitrate group alone; (2) binary groups containing the groups of nitrate-phosphate, nitrate-sulfate, nitrate-fluoride, nitrate-nitrite, and nitrate-carbonate; (3) combined nitrate, phosphate, sulfate, and fluoride groups and (4) combined nitrate, phosphate, sulfate, fluoride, nitrite, and carbonate groups. IPA was used as a precipitation solvent. The objectives of this stage were to evaluate the interactions of these groups in the absence of the hydroxide group (e.g. DOE acid-dissolved sludge and acidified supernate streams), and the influence of such interactions on the individual removal of the targeted species. The removal of the aluminum, phosphate, fluoride, and alkaline cations were significantly high (reached 99.9%). The removal of sulfate were moderately high (reached 87%), and the removal of nitrate and alkali cations including cesium were to some extent low (reached about 50%). In the third stage, the precipitation of inorganic species from the simulated NCAW stream was studied using IPA and ethylamine (EA). The precipitation process is very feasible for reducing the radioactivity contents of alkaline cations. However, the process is less effective in separating alkali cations including cesium. The removal of polyvalent transition metals such as aluminum ion is negatively influenced by the significant presence of hydroxide. While the process is effectively capable of separating phosphate, fluoride, and sulfate, it is significantly less effective in separating nitrate and nitrite. A previously derived thermodynamics framework was used to model the precipitation measurements. The framework provided two predictive equations (the 2-Suffix and 3-Suffix equations). Both equations were reasonably adequate for predicting the solubility phase behavior of tested inorganic species in a mixed-solvents mixture as well as for estimating optimum interaction parameters. However, the 3-Suffix equation was better than the 2-Suffix equation. The parameters were useful for estimating the: (1) precipitation fractions (%P) of the studied species, for instance, at different concentration levels of similar targeted species, or in different waste streams with similar or approximate abundance of species, or at different solvents volume ratio (V(r)) where no experimental data are available.

Chemical Precipitation↗

PubMed2000

[Influence of the radioactive strontium (89Sr) using for nuclear medical radiation therapy upon radioactive draining-water system].

PURPOSE: Strontium-89 chloride (89Sr) is a new radiopharmaceutical that provides effective pain relief for metastatic bone lesions, and is expected to be available soon in the palliative management for metastatic bone pain in Japan. Because of relatively long physical half life (50.5 days), 89Sr may affect to the radioactive draining-water system by exceeding the limits of activity concentration for radioactive drain. In this article, the influence of 89Sr use on the radioactive drainage system was simulated. METHODS: The standard tank capacity of drainage and draining frequency was determined from the results of questionnaire carried out for the nationwide medical and research institutes where radioisotope treatment are performed. On the assumption that 89Sr of 148 MBq for one therapy was used twice a week and several common radionuclides were used as the same activity as used at Chiba Cancer Center, the influence of 89Sr was estimated. The calculation was performed using the activity contamination ration into the draining-water system of each radionuclide of 0.01, which was legally determined. RESULTS: The simulation revealed that the sum of the contamination ratios of individual radionuclides exceeded a legal value of 1.0 in standard drainage with the capacity of 5 m3 and 10 m3 and draining frequency of 7 times per year. The actual contamination ratios of common radiopharmaceuticals measured at Chiba Cancer Center ranged from 1/100 to 1/1000 of the legal values. CONCLUSION: It is necessary that the legal value of activity contamination ratios into the draining-water system should be reassessed before starting 89Sr therapy.

Bone Neoplasms↗

PubMed1991

Co-expression of cholecystokinin mRNA and tyrosine hydroxylase mRNA in populations of rat substantia nigra cells; a study using a combined radioactive and non-radioactive in situ hybridization procedure.

Improvements in the sensitivity of non-radioactive in situ hybridization histochemistry methods for detection of mRNA now make it feasible to combine the use of non-radioactive and radioactive in situ methods to visualize two mRNAs on the same tissue section. The method reported here allows the simultaneous detection of two mRNAs in one cell and therefore is ideally suited to the studies of co-expression. Here we demonstrate the co-expression of tyrosine hydroxylase (TH) mRNA and cholecystokinin (CCK) mRNA in the ventral mesencephalic dopaminergic neurones of the rat. The distribution of dopaminergic neurones containing both TH and CCK transcripts suggests, on the basis of earlier anatomical studies that these CCK/TH-containing doubled-labelled cells project mainly to the striatal matrix. Dopamine neurones believed to project to the patch compartment did not contain CCK mRNA.

Animals↗

PubMed1986

Detection of chromosome aberrations in the human interphase nucleus by visualization of specific target DNAs with radioactive and non-radioactive in situ hybridization techniques: diagnosis of trisomy 18 with probe L1.84.

The localization of chromosome 18 in human interphase nuclei is demonstrated by use of radioactive and non-radioactive in situ hybridization techniques with a DNA clone designated L1.84. This clone represents a distinct subpopulation of the repetitive human alphoid DNA family, located in the centric region of chromosome 18. Under stringent hybridization conditions hybridization of L1.84 is restricted to chromosome 18 and reflects the number of these chromosomes present in the nuclei, namely, two in normal diploid human cells and three in nuclei from cells with trisomy 18. Under conditions of low stringency, cross-hybridization with other subpopulations of the alphoid DNA family occurs in the centromeric regions of the whole chromosome complement, and numerous hybridization sites are detected over interphase nuclei. Detection of chromosome-specific target DNAs by non-radioactive in situ hybridization with appropriate DNA probes cloned from individual chromosomal subregions presents a rapid means of identifying directly numerical or even structural chromosome aberrations in the interphase nucleus. Present limitations and future applications of interphase cytogenetics are discussed.

Cell Nucleus↗

PubMed1985

Radioactive methionine: determination, and distribution of radioactivity in the sulfur, methyl and 4-carbon moieties.

A simple and inexpensive method is described for isolation and determination of [14C]methionine in the non-protein fraction of tissues extensively labeled with 14C. The effectiveness of the method was demonstrated by isolation of non-protein [14C]methionine (as the carboxymethylsulfonium salt) of proven radiopurity from the plant Lemna which had been grown for a number of generations on [U-14C]sucrose and contained a 2000-fold excess of 14C in undefined non-protein compounds. To our knowledge, this is the first reported assay for radioactive methionine under these demanding conditions. This method also offers an attractive alternative to the use of more expensive and sophisticated equipment for assay of radioactive methionine under less demanding conditions. An advantage is that the isolated methioninecarboxymethylsulfonium salt is readily degraded to permit separate determination of radioactivity in the 4-carbon, methyl and sulfur moieties of methionine. During this work, a facile labilization of 3H attached to the (carboxy)methylene carbon of methioninecarboxymethylsulfonium salt was observed. This labilization is ascribed to formation of a sulfur ylid.

Carbon↗

PubMed1971

Use of unabsorbed radioactive marker substances in a re-assessment of the radioactive triolein test of fat absorption.

The radioactive triolein test has been compared with two chemical methods for the assessment of fat absorption in a group of inpatients from general medical wards. The special feature of the investigation is the use of a radioactive faecal marker to measure the completeness of faecal collections during the investigation period. Estimations of unabsorbed (131)I triolein and faecal fat measured by the chemical methods were made on the same specimens. The results showed that only 48% of the patients provided a complete collection of faeces (defined as a recovery of more than 90% of the faecal marker). From these patients good correlations were found between the triolein absorption test and the two chemical methods.It is suggested that previous criticism of the radioactive triolein test may have been due to incomplete faecal collections causing false results.

Chemistry Techniques, Analytical↗

PubMed1990

[Nucleic acid hybridization for direct detection of Chlamydia trachomatis. Comparison of a radioactive with a non-radioactive procedure].

A total of 234 urogenital specimens were investigated with a radioactive and a nonradioactive rRNA:cDNA-hybridization test for the direct detection of Chlamydia trachomatis (Gen-Probe, San Diego, Calif.). The results were compared with those yielded by the conventional cell culture technique (McCoy cells). Using cell culture a urogenital C. trachomatis infection could be detected in 37 of 234 patients (15.8%) at two outpatient sexually transmitted disease clinics. Referred to the detection rate, cell culture sensitivity was 83.8% for the radioactive test and 86.5% for the nonradioactive DNA-hybridization test. The specificity of the radioactive test was 94.8% and that of the nonradioactive test, 93.4%.

Cells, Cultured↗

PubMed1993

[Content of radioactive cesium in selected food products. Radioactive cesium in daily food rations of selected population groups].

The content of radioactive caesium isotopes emitting beta radiation was studied in daily food rations analysed in diets of working-class and non-working-class families from food products from the regions of Olsztyn, Poznań, Lublin, Warsaw and Wrocław in 1987 and 1988. In 1987 the highest level of radioactive caesium was found in the food rations in Olsztyn, and the lowest in the rations in Poznań (3.32 and 0.65 Bq/kg respectively). In 1988 higher radio-caesium content was found in rations composed according to the data on the diet consumed daily in non-working-class families. In that case the highest content was in the daily food ration composed in Warsaw--2.35 Bq/kg, and lowest in Poznań--1.19 Bq/kg. In the daily food rations of working-class families about one half of that value was found. The calculated mean values of both analysed rations were: 1.35 for Olsztyn, 0.89 for Poznań, and 1.86 Bq/kg for Warsaw. The calculated mean value of the contamination with radioactive caesium was in 1988 0.93 Bq/kg for the rations in working-class families (in 1987 it was 1.80 Bq/kg).

Cesium Radioisotopes↗

PubMed1978

[Draining of radioactive waste water from departments working with radioactive material after introduction of the law for radiation protection (author's transl)].

In order to establish the drainage of radioactive waste water 1976 in the Federal Republic of Germany a new law for radiation protection was introduced. In this paper a concept is introduced how to determine specifications for constructing a decay plant using the given data of a department for nuclear medicine. The given boundary conditions were to secure a low concentration of radioactive material in order to establish the drainage of extreme low activities without diluting it.

Berlin↗

PubMedDate not supplied

Sex determination of blood stains with a recombinant DNA probe: comparison with radioactive and non-radioactive labeling methods.

A recombinant DNA probe hybridizing specifically to human repeat DNA sequence (pHY10) of which about 3000 copies are present on the Y chromosome was used for sex determination of degraded DNA samples of blood stains. Human blood stains of male and female origin were readily differentiated with the pHY10 DNA probe. This radioactive technique enabled reliable and sensitive sex determination from blood or dried blood stains greater than 20 years old. Less than 1 microliter of blood or 1 piece of 0.5 cm length thread of blood stain from cotton fabric was sufficient for the test using dot blot hybridization. Compared with the radioactive labeling method, the photobiotin labeling method showed one thirtieth to one fiftieth lower sensitivity and presented some problems which are expected to be resolvable.

Blood Stains↗

PubMed1995

A methodology for evaluating the toxicity of radioactive waste and its application to the radioactive waste generated in Pennsylvania.

Communicating with the public on the risks of low-level radioactive waste disposal is difficult due to the lack of comparisons that are understandable to the public. This paper presents a methodology for analyzing the intrinsic toxicity of radionuclides in waste and comparing it to that for soil or other wastes that may contain naturally-occurring radionuclides. The intrinsic toxicity of each radionuclide is normalized by dividing its specific activity in the waste by an appropriate ingestion risk standard, such as the U.S. EPA proposed drinking water limits. To illustrate the usefulness of this method, it was used to analyze Pennsylvania's commercial low-level radioactive waste inventory. The results are presented along with an indication of the usefulness of this method for screening purposes to analyze and identify problematic constituents in various waste streams.

Evaluation Studies as Topic↗

PubMed2001

Radioactive waste discharge quantities for patients undergoing radioactive iodine therapy for thyroid carcinoma.

There is a need to provide realistic estimates of the activity discharged to the drains by patients undergoing procedures involving unsealed radionuclides. These estimates are essential for record keeping purposes, to demonstrate compliance with limits set in waste disposal authorizations and for planning new installations. In this study, we report the discharge of activity for 174 patients (202 treatments) undergoing treatment of thyroid carcinoma with radioactive iodine. We have found that approximately 55% of administered activity is excreted in the first 24 h and that 85% of administered activity is discharged to the sewer over a typical inpatient stay of 5 days. There was no significant difference in levels of discharge between those patients undergoing inaugural ablation therapy and those having further treatments with radioactive iodine.

Iodine Radioisotopes↗

PubMed1991

Studies of radioactivity produced by the Hiroshima atomic bomb: 1. Neutron-induced radioactivity measurements for dose evaluation.

This review summarizes measurements made of 152Eu and 60Co radioactivity induced by neutron radiation from the Hiroshima atomic bomb (A-bomb) with the goal of estimating the neutron dose released by the bomb. Prior to these measurements, A-bomb-irradiated specimens such as rocks and pieces of concrete, which had not been shielded were collected. The specific radioactivity obtained (in bequerels per gram of Eu or Co) were compared with those calculated from DS86 neutrons. Findings of usefulness of 152Eu data within 700 m ground range are reported and systematic differences between measured activities and calculations are discussed. The 152Eu data were also useful for the discussion of circular asymmetry, and there was no asymmetry within the experimental errors. This review also covers the similar difference found in 32P data, which were measured immediately after the A-bomb, along with the other 152Eu and 60Co data. The need for more measurements of 152Eu activity in samples farther away from the hypocenter in order to verify the DS86 calculations is also discussed.

Humans↗