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PubMed1995

Quantitative non-radioactive clonality analysis of human leukemic cells and progenitors using the human androgen receptor (AR) gene.

Clonal analysis of FACS-purified primitive hematopoietic stem cells and of their progeny as assessed by the progenitors obtained from long-term cultures requires PCR-based approaches, mainly because of the low number of cells available. We have developed a non-radioactive androgen receptor (AR) assay which allows a simple and quantitative evaluation of the clonality of hematopoietic cells and progenitors. In this approach 5' AR primer is labelled by fluorescein and the amplified product is run on a sequencing gel which allows evaluation of the intensity of the fluorescent peaks generated. A computer software then analyzes the reduction of the intensity of the peaks on HpaII-digested samples. In order to determine the feasibility of the technique, we analyzed the clonality of leukemic cells from a patient with an acute-phase CMML which showed a typical clonal pattern of her leukemic DNA sample (WBC = 300 x 10(9)/I) using phosphoglycerate kinase (PGK) analysis. The same sample was then analyzed with either radioactive- or fluorescein-labelled AR primers, showing a typical clonal pattern (complete disappearance of one allele after HpaII digestion). A short-term clonogenic assay was then set up on methylcellulose and clonogenic progenitors were individually analyzed. All 24 colonies tested showed a typical clonal pattern with the disappearance of the same allele on each sample after HpaII digestion, indicating that they all derived from the same leukemic stem cell. Using this approach we then analyzed 94 patients with several hematologic malignancies and quantification of their fluorescent peaks. Fifty-four percent of the patients were clearly heterozygous (ie, a difference of > or = 2 CAG repeats was present between the two copies of the gene) and could be analyzed in an automatic sequencer using the fluorescent primers. Bone marrow mononuclear cells from all patients with acute myeloid leukemia (AML) showed a clonal or oligoclonal pattern at diagnosis whereas a polyclonal pattern was seen when remission was obtained. Similarly, out of 21 patients with a diagnosis of myelodysplastic syndrome (MDS), a clonal pattern was demonstrated in 10 whereas an oligoclonal or non-clonal pattern was shown in 11. These results show that this non-radioactive and safe technology can now be used on a large scale to evaluate the clonality of highly purified hematopoietic stem cells and their progenitors in hematopoietic malignancies and this might allow new insights into the targets of clonal amplification.

Acute Disease↗
PubMed1993

Effect of ciprofloxacin on the disposition of 14C-dideoxyinosine-derived radioactivity in the rat.

The potential for the antibacterial agent ciprofloxacin to interfere with the disposition of the antiviral agent dideoxyinosine (ddI) was evaluated in adult male Wistar rats. The combination group (n = 10) was dosed orally with 100 mg/kg ciprofloxacin in water every 12 h for three consecutive doses. Thirty minutes after the last dose, a bolus IV injection of 50 mg/kg 14C-ddI in physiologic saline was given over 7-10 sec through the penile vein. The control group (n = 8) received a single dose of IV 14C-ddI. Blood, urine and fecal samples were collected from 0-4 h, and tissue samples were removed at 4 h after ddI administration. The disappearance of 14C from blood followed the kinetics of a two-compartment model with bolus input and first-order output. The following pharmacokinetic parameters (mean +/- SD) were calculated based on total blood radioactivity for the 14C-ddI alone and combination groups, respectively: blood clearance 13.5 +/- 2.0 vs. 12.7 +/- 1.5 ml/min/kg, terminal disposition half-life 49.9 +/- 2.2 vs. 49.0 +/- 6.0 min, steady-state volume of distribution 891 +/- 134 vs. 825 +/- 126 ml/kg, mean residence time 66.2 +/- 3.1 vs. 65.0 +/- 7.8 min (the power to detect a 20% decrease in the above parameters, relative to the reference ddI alone, was > 85% at the 5% significance level), percentage of administered dose recovered in urine 62.2 +/- 9.8% vs. 56.6 +/- 13.0%. Most of the radioactivity in tissues was concentrated in the liver, adrenal, spleen and kidney. Except for significant decreases (p < 0.05) in the levels of 14C in skeletal muscle and cecum of combination treated rats, the coadministration of ciprofloxacin showed no differences in either the tissue levels of 14C or the pharmacokinetic parameters of 14C-ddI-derived radioactivity. The results obtained with total 14C measurements suggest that ciprofloxacin does not alter the disposition of ddI in the rat, although unchanged ddI was not determined.

Administration, Oral↗
PubMed1995

The digoxigenin (DIG) system for non-radioactive labelling and detection of nucleic acids--an overview.

The use of non-radioactive nucleic acid probes has increased dramatically over the last years. The convenience of not having to deal with radioactive isotopes combined with the stability and economy of the non-radioactive systems has led to applications in various techniques. One of the most successful labelling and detection systems is based on the hapten digoxigenin. Here, the different methods for labelling nucleic acids with digoxigenin as well as the various possibilities for detection are described. Some typical applications illustrate the utility of the DIG system.

Animals↗
PubMed1996

The reactions of euthyroid and hyperthyroid glands to radioactive iodine.

BACKGROUND: Researchers generally assume that the thyroid gland reacts more or less comparably to external irradiation and radioactive iodine. DESIGN: The thyroid glands from 20 euthyroid patients and 20 hyperthyroid patients, all of which had been treated with radioactive iodine, were studied. RESULTS: The two groups manifested different reactions. Almost all the euthyroid glands displayed a fibrotic atrophic pattern, whereas the glands from the Graves' disease patients showed more adenomatous and Hashimoto lesions than atrophy. CONCLUSION: Differences in the reactivity of normal and hyperplastic follicles may cause different reactions to treatment with radioactive iodine.

Adenoma↗
PubMed1996

[Drug susceptibility test for Mycobacterium tuberculosis using non-radioactive substance, alpha-antigen].

BACTEC system is a reliable and rapid drug susceptibility test for mycobacteria and is widely accepted in Europe and in the United States of America. In Japan, it is impossible to introduce the BACTEC system in clinical laboratories because of strict regulations for the use of radioactive substances in Japan. To resolve this dilemma, we adopted alpha-antigen (alpha-antigen), a widely distributed secretory protein of mycobacteria, as the index substance replacing the radioactive substance 14C in BACTEC system. Alpha-antigen was detected by reverse passive latex agglutination (LA), using latex sensitized with rabbit anti-alpha-IgG. Susceptibility of 17 M. tuberculosis strains isolated from patients, grown on Ogawa egg medium and then cultured in 7H9 medium, and of 46 M. tuberculosis strains freshly isolated from patients by 7H9 medium of MB check system, was tested for four antituberculosis drugs, isoniazid (INH), rifampicin (RFP), streptomycin (SM) and ethambutol (EB). Ninety four percent of the control cultures were positive for alpha-antigen within 7 days after the inoculation. The MIC values of H37Rv strain in 7H9 medium determined by the method of Heifets were 0.05 micrograms/ml for INH, 0.03 micrograms/ml for RFP, 0.025 micrograms/ml for SM and 1.9 micrograms/ml for EB. In 17 strains from Ogawa egg medium, the results obtained from all but 4 strains for SM, 1 for INH, 1 for RFP and 7 for EB were concurrent with that obtained by the method using 1% Ogawa egg medium. No strains were determined to be resistant to any drug by the alpha-antigen method and be sensitive by the Ogawa medium method. In 46 strains cultured by the MB check system, the results of 42 strains for SM, 35 for INH, 39 for RFP and 36 for EB coincided with those determined by the Microtiter method. Among the strains determined to be resistant by Microtiter method, 1/2 for SM, 10/14 for INH, 4/17 for RFP and 8/10 for EB were determined to be sensitive by alpha-antigen LA method. The disagreement was seen mostly in strains which were determined to be resistant by the method using egg medium, while sensitive by the alpha-antigen LA method. The discrepancy might originate from the difference of critical concentration due to heat inactivation of the drugs and absorption in the egg medium. However, some instability was observed in latex agglutination and its cause should be examined further. This method of utilizing 7H9 medium for culture and alpha-antigen as the index of mycobacterial growth can be an expedient and economical drug susceptibility test because it does not use radioactive substance as in the case of BACTEC system.

Animals↗
PubMed1977

Radioactivity in pituitaries and cerebrums of neonatal rats following [3H]-estradiol administration.

The uptake of radioactivity by the pituitary, cerebrum and muscle of female and male neonatal and prepuberal rats 1 hour after administration of [3H]-estradiol was measured by liquid scintillation. Tissues were homogenized and aqueous, lipid, and protein-nucleoprotein fractions were separated for quantification of radioactivity. No significant sex differences in the radioactivity associated with the pituitary fractions were noted at any of the ages studied.

Animals↗
PubMed1997

Changes in radioactive tracer distribution in rats after 24 hours of 45 degrees hind limb unweighting.

INTRODUCTION: Changes in radioactive tracer distribution were examined in rats after exposure to a simulated microgravity model of 45 degrees head down tilt (45HDT) or 45 degrees hind limb unweighting (45HU) for up to 24 h. METHODS: Rats were randomly assigned to either 45HDT (or 45HU) experimental groups or control groups for each time point of 0.5 h, 1 h, 2 h, 4 h, 8 h, or 24 h. The 0.5-h through 8-h experimental rats were anesthetized and placed head-down on a ramp at 45 degrees, while control rats were placed in a prone position. Non-anesthetized rats in the 24-h experimental group were tail-suspended at 45 degrees, while control rats were allowed unrestrained movement. Technetium-labeled diethylenetriamine pentaacetate (99mTcDTPA, physical half-life of 6.02 h, MW = 492 amu) and indium-labeled diethylenetriamine pentaacetate (111In DTPA, physical half-life of 3.5 d, MW = 545 amu) were used to measure body organ distributions of the radioactive tracers at the 0.5-h-8-h and 24-h time points, respectively. Major organs were harvested after each time period and measured for radioactive counts. Light and electron micrographs were examined. RESULTS: Mean 111InDTPA counts for the lungs, kidneys, and brains of the 24 h 45HU groups were significantly higher than control counts. Light and electron microscopy demonstrated the development of pulmonary edema in the alveolar septal areas after 2 h of 45HDT, and a shift in edema to the pulmonary airways and pulmonary arteries after 24 h of 45HU. CONCLUSIONS: Pulmonary edema development, accompanied by a significant increase in 111InDTPA lung, kidney, and brain counts in the 24-h 45HU groups, suggests vascular injury in the microcirculation of these organs.

Animals↗
PubMed1977

[Distribution of radioactive tetanus toxin at the subcellular level].

Experiments were carried out on rabbits for detecting the distribution of radioactive tetanotoxin between subcellular fractions of tissues of the central nervous system. It has been found out that a parenteral administration of tetanotoxin-35S results in a quick rise of the tissue radioactivity. The radioactivity of the free ribosome fraction remained most constant and high, which might be an indication of a high acceptory capacity of these organelles to tetanotoxin. For some periods of an acute tetanus intoxication, a rather high tropism of tetanotoxin of synaptosome, microsome and myelinic fragments was found.

Animals↗
PubMed1997

Radioactive synoviorthesis in patients with hemophilia with factor inhibitor.

In nine patients with hemophilia and factor inhibitor (six with hemophilia A; three with hemophilia B), 19 joints were treated with radioactive synoviorthesis using Au-198. Ages ranged from 3 to 40 years. Synoviorthesis was performed when the antibody titer was low (< 10 Bethesda units), thus making hemostasis possible by factor administration for 2 to 4 days. On five occasions, radioactive synoviorthesis was performed simultaneously with tolerance induction according to the Malmö protocol. A bleeding free interval of more than 6 months was obtained in 11 joints, six of which remained bleeding free for more than a year. At long term followup (range, 18-182 months) five joints were rated good, one joint was fair, and 11 joints were poor. Although the results are inferior to those for patients with hemophilia without inhibitor, radioactive synoviorthesis should be considered because of its ease of performance and the definite decrease in joint bleeding frequency that it brings about. This is of particular interest in patients with hemophilia caused by factor inhibitor who otherwise are difficult to treat.

Adolescent↗
PubMed1976

Rates of disappearance from plasma of enzymes labeled by coupling with a radioactive lodo-ester.

Lactate dehydrogenase-5 and creatine kinase from rabbit muscle were labeled by coupling with N-hydroxysuccinimidyl 3-(4'-hydroxy-[3',5'-125I]diiodophenyl)propionate. After purification, the analytical recovery of catalytically-active labeled enzyme averaged 90% for lactate dehydrogenase, 81% for creatine kinase. The labeled enzymes were injected intravenously into rabbits and disappearance from plasma of catalytic activity and radioactivity was measured. The disappearance curves for lactate dehydrogenase-5 differed considerably from those observed with the enzyme labeled by direct iodination. The discrepancy was due to rapid hydrolysis in vivo of the labeled amide-enzyme linkage, because about 50% of the injected radioactivity appeared in the urine as 125I-labeled 3-(4'-hydroxy-3',5'-diiodophenyl)propionic acid within 4-8 h of injection. Similar outputs were observed after administration of this acid to rabbits. The free acid was also detected in the urines of rabbits within 4-8 h of the intravenous injection of creatine kinase labeled similarly. We conclude that this method of labeling is unsuitable for preparing radioactive enzymes for study of their catabolism.

Animals↗
PubMedDate not supplied

Effect of the distribution of radioactive sources on deadtime loss in a single-crystal gamma camera.

Quantitative studies with a single-crystal gamma camera often require correction for deadtime count loss. We evaluated the deadtime characteristics of a gamma camera using point sources. Point sources with various radioactivities were measured, and the relation between radioactivity and count rate was assessed. Two sources with different activities were imaged apart or adjacent to each other, and the effect of the geometrical distribution on counting efficiency was investigated. Count loss was increased at a high radioactivity level, and was well corrected using a nonparalyzable model and a deadtime of 4.99 microsec. It was not affected by the distance between the two sources, and occurred equally for the two sources imaged together. The count loss in imaging two sources was successfully corrected by multiplying the obtained image by a correction factor based on the count rate in the whole field-of-view. These results support the reliability of the analytic technique for deadtime correction.

Calibration↗
PubMed1999

Simultaneous recovery of size and radioactivity concentration of small spheroids with PET data.

UNLABELLED: Quantification of tumor activity is used to predict prognosis and discriminate benign from malignant lesions identified by PET. Accurate quantitation of small lesions requires correction for the partial volume effects. Such a correction is often based on the recovery coefficient (RC), which depends on the lesion size, the object-to-background ratio (OBR) and physical properties of the media. The purpose of this investigation was to determine whether a model-based optimization method to simultaneously recover the size and the activity concentration of small spheroids could improve estimates of lesion radioactivity when object size is unknown. For reference, we compared our method with a widely used approach, RC correction, that requires the object size to be known. METHODS: A three-dimensional, spatially varying, object size- and contrast-dependent Gaussian model of the point spread function (PSF) of an ECAT EXACT was developed. The observed dependence of the PSF on random coincidences and measured-peak/background activity were included in the PSF using three adjusting factors. Size and radioactivity concentration of a spheroid were estimated by adjusting size and concentration until model output best matched the image data. Elliptic and circular phantoms both containing seven hot spheroids, with OBRs ranging from 5.6 to 0 background, were evaluated. RESULTS: The proposed quantification method reduced the activity error by 11%-63% of the error obtained without correction. The greatest error reduction occurred for small spheroids. The average error in radius estimation ranged from 2% to 48%, wherein the smallest spheroid produced the largest errors. For spheroids with diameters from 8 to 22 mm, Student t test (paired, one-tail) showed the proposed method significantly improved accuracy (P < 0.05) in comparison with the RC method and also in comparison with optimization without the three adjusting factors. CONCLUSION: The model-based optimization method improved estimation of radioactivity concentration over that corrected by the RC method and that made without any correction. It also provided accurate estimation of size for spheroids larger than 6 mm in diameter.

Models, Theoretical↗
PubMed2004

Radioactive contamination in the upper part of the Techa river: stirring-up of bottom sediments and precipitation of suspended particles. Analysis of the data obtained in 1949-1951.

A hydrodynamic model of the upper part of the Techa river was developed on the basis of the river valley geometry as well as data of hydrological conditions and of the granulometric composition of bottom sediments. The model describes the transport of radioactivity by suspended sediments with different granulometric compositions (clay, silt) in the early 1950s. It includes the stirring-up of bottom sediments and the precipitation of suspended sediments as a function of water discharge rate and water level in the investigated part of the river. The results allow to specify the development of the river system contamination as a result of inflow of suspended sediments contaminated with radionuclides. In the period of liquid radioactive waste (LRW) discharges, the water of the Techa river contained a large fraction of finely dispersed particles of less than 5 micro m diameter. At the site of LRW discharge 80% of the discharged activity was adsorbed to these particles. Depending on the water flow, 40-80% of the suspensions precipitated at the bottom of subsequent sedimentation reservoirs. A total of about 1.6 MCi adsorbed to the suspended particles entered the open hydrographic system of the Techa river. The conclusion that the largest part of the activity was adsorbed on the suspended particles contradicts the assumption in the Techa river dosimetry system, TRDS-2000, that most of the released activity entered the Techa river in soluble form. For a correct reconstruction of the doses received by the Techa river population it is, therefore, essential to consider hydrodynamic models that take into account the transport of radionuclides adsorbed on the suspended particles.

Geologic Sediments↗
PubMed1998

Measurement of resuspended aerosol in the Chernobyl area. Part III. Size distribution and dry deposition velocity of radioactive particles during anthropogenic enhanced resuspension.

During anthropogenic activities, such as agricultural soil management and traffic on unpaved roads, size distribution measurements were performed of atmospheric particulate radionuclides at a site in the Chernobyl 30-km exclusion zone. Analysis of cascade impactor measurements showed an increase of the total atmospheric radioactivity. In the cases of harrowing by a tractor and traffic on unpaved roads, a common shape of the size distribution was found with two maxima, the first in the 2-4 microm range, the second in the 12-20 microm range. The size distributions were compared to measurements during wind-driven resuspension. Particle number concentration measurements with an Aerodynamic Particle Sizer showed a dynamic dependence of the particle concentration in different size ranges on anthropogenic action. The increase of the mean concentration was for the large particles more than one order of magnitude higher than for fine particles during anthropogenic enhanced resuspension. From the measurement of the mass concentration, the radioactive loading could be estimated. An enrichment of radionuclides on resuspended particles (compared to soil particles) was found, with the highest enrichment for large particles. Micrometeorological considerations showed that large particles may frequently be subject to medium range transport. The dry deposition velocity was measured; the mean value of 0.026 m s(-1) +/- 0.016 m s(-1) is typical for 6-9 microm diameter particles.

Aerosols↗
PubMed1993

Using a bank of predatory fish samples for bioindication of radioactive contamination of aquatic food chains in the area affected by the Chernobyl accident.

From the analysis of experimental data on radioactive contamination of various fish, it is suggested that predatory fish specimens can be used as bioindicators of radionuclide accumulation in reservoir food chains of the Chernobyl emergency area. The increased content of cesium radionuclides were detected in the muscle tissue of predatory fish collected in various regions of the Chernobyl emergency area. In most of the water bodies studied, maximum contamination levels of predatory fish by radionuclides of cesium occurred in 1987-1988, whereas in 'nonpredatory' fish the concentration of cesium was maximum, as a rule, in the first year following the accident. The exposure doses of fish of various ecological groups and ages are estimated. The exposure doses of various population groups, using fish from contaminated water bodies, are also estimated. When forming the environmental data bank for the Chernobyl accident zone it is suggested that perch, pike-perch and pike be used as bioindicators of radioactive contamination of food chains.

Accidents↗
PubMedDate not supplied

Multisyringe flow injection analysis of stable and radioactive strontium in samples of environmental interest.

A multisyringe flow injection (MSFIA) method for the determination of stable and radioactive strontium, using a solid phase resin (Sr-Resin), has been developed. Strontium concentrations are determined by atomic emission spectroscopy and by a low background proportional counter. The method has been applied to different samples (water, milk and soil) of environmental interest. The LLD of the stable and radioactive Sr were 10 microg/l and 0.01 Bq, respectively. The standard deviation of the separation procedure is 2% (n=10).

Animals↗
PubMed2005

Bioremediation of radioactive waste: radionuclide-microbe interactions in laboratory and field-scale studies.

Given the scale of the contamination associated with 60 years of global nuclear activity, and the inherent high financial and environmental costs associated with invasive physical and chemical clean-up strategies, there is an unparalleled interest in new passive in situ bioremediation processes for sites contaminated with nuclear waste. Many of these processes rely on successfully harnessing newly discovered natural biogeochemical cycles for key radionuclides and fission products. Recent advances have been made in understanding the microbial colonization of radioactive environments and the biological basis of microbial transformations of radioactive waste in these settings.

Bacteria↗
PubMed2004

Radioactive contamination of wild mushrooms: a cross-cultural risk perception study.

The aim of the present work was to determine the public perception of radioactive contamination of wild mushrooms, to confront this perception with an expert opinion, and to determine those factors that are perceived differently by specialists and lay people. The Internet appeared to be a useful tool in attaining these goals by finding the appropriate people across the world. The statistically significant differences in the perception of various aspects of mushroom pollution were revealed between respondents from three world regions, which were differently affected by the Chernobyl accident. Moreover, the majority of people have demonstrated a considerable difference in the perception of the global contamination of the environment versus the pollution of their local counties. The socio-psychological explanations of data are given. In general, there is a steady consistency in the perception of factors, which may control the radioactive contamination of edible fungi, by the majority of respondents. However, experts (radioecologists) rank the factor of fungal species as an extremely important parameter, while other people perceive the factors of the distance from the source of the pollution and the time thereafter as the most important parameters. Such discrepancies between professional and unprofessional opinions are discussed and some recommendations for risk communications are presented.

Agaricales↗