WorldWideScience

Sample records for gamma release assays

  1. Gamma Interferon Release Assays for Detection of Mycobacterium tuberculosis Infection

    Science.gov (United States)

    Denkinger, Claudia M.; Kik, Sandra V.; Rangaka, Molebogeng X.; Zwerling, Alice; Oxlade, Olivia; Metcalfe, John Z.; Cattamanchi, Adithya; Dowdy, David W.; Dheda, Keertan; Banaei, Niaz

    2014-01-01

    SUMMARY Identification and treatment of latent tuberculosis infection (LTBI) can substantially reduce the risk of developing active disease. However, there is no diagnostic gold standard for LTBI. Two tests are available for identification of LTBI: the tuberculin skin test (TST) and the gamma interferon (IFN-γ) release assay (IGRA). Evidence suggests that both TST and IGRA are acceptable but imperfect tests. They represent indirect markers of Mycobacterium tuberculosis exposure and indicate a cellular immune response to M. tuberculosis. Neither test can accurately differentiate between LTBI and active TB, distinguish reactivation from reinfection, or resolve the various stages within the spectrum of M. tuberculosis infection. Both TST and IGRA have reduced sensitivity in immunocompromised patients and have low predictive value for progression to active TB. To maximize the positive predictive value of existing tests, LTBI screening should be reserved for those who are at sufficiently high risk of progressing to disease. Such high-risk individuals may be identifiable by using multivariable risk prediction models that incorporate test results with risk factors and using serial testing to resolve underlying phenotypes. In the longer term, basic research is necessary to identify highly predictive biomarkers. PMID:24396134

  2. An interferon-gamma release assay test performs well in routine screening for tuberculosis

    DEFF Research Database (Denmark)

    Vestergaard Danielsen, Allan; Fløe, Andreas; Lillebæk, Troels

    2014-01-01

    Introduction: A positive interferon-gamma release assay (IGRA) is regarded as proof of latent Mycobacterium tuberculosis infection. We conducted an evaluation of the IGRA test “T-SPOT.TB” to test its performance during clinical routine use by analysing the positivity rate and odds, effect of season...... and sensitivity. Material and methods: Data from T-SPOT.TB testing together with age and test indications (anti-tumour necrosis factor alpha (TNFα) candidate, contact investigation or suspicion of tuberculosis (TB)) were combined with mycobac­teria culture results. Results: A total of 1,809 patients were tested....... Conclusive results were achieved for 1,780 patients (98.4%). Among these, 4.6% of anti-TNFα candidates, 19.3% of contacts and 24.4% of TB suspects tested positive. Compared with anti-TNFα candidates, the odds for a positive result were significantly higher for contact investigations (odds ratio (OR), mean...

  3. Reproducibility of Interferon Gamma (IFN-γ) Release Assays. A Systematic Review

    Science.gov (United States)

    Tagmouti, Saloua; Slater, Madeline; Benedetti, Andrea; Kik, Sandra V.; Banaei, Niaz; Cattamanchi, Adithya; Metcalfe, John; Dowdy, David; van Zyl Smit, Richard; Dendukuri, Nandini

    2014-01-01

    Rationale: Interferon gamma (IFN-γ) release assays for latent tuberculosis infection result in a larger-than-expected number of conversions and reversions in occupational screening programs, and reproducibility of test results is a concern. Objectives: Knowledge of the relative contribution and extent of the individual sources of variability (immunological, preanalytical, or analytical) could help optimize testing protocols. Methods: We performed a systematic review of studies published by October 2013 on all potential sources of variability of commercial IFN-γ release assays (QuantiFERON-TB Gold In-Tube and T-SPOT.TB). The included studies assessed test variability under identical conditions and under different conditions (the latter both overall and stratified by individual sources of variability). Linear mixed effects models were used to estimate within-subject SD. Measurements and Main Results: We identified a total of 26 articles, including 7 studies analyzing variability under the same conditions, 10 studies analyzing variability with repeat testing over time under different conditions, and 19 studies reporting individual sources of variability. Most data were on QuantiFERON (only three studies on T-SPOT.TB). A considerable number of conversions and reversions were seen around the manufacturer-recommended cut-point. The estimated range of variability of IFN-γ response in QuantiFERON under identical conditions was ±0.47 IU/ml (coefficient of variation, 13%) and ±0.26 IU/ml (30%) for individuals with an initial IFN-γ response in the borderline range (0.25–0.80 IU/ml). The estimated range of variability in noncontrolled settings was substantially larger (±1.4 IU/ml; 60%). Blood volume inoculated into QuantiFERON tubes and preanalytic delay were identified as key sources of variability. Conclusions: This systematic review shows substantial variability with repeat IFN-γ release assays testing even under identical conditions, suggesting that reversions

  4. Frequency of indeterminate results from an interferon-gamma release assay among HIV-infected individuals

    Directory of Open Access Journals (Sweden)

    Sandra Maria do Valle Leone de Oliveira

    Full Text Available ABSTRACT Objective: To evaluate the frequency of and factors associated with indeterminate interferon-gamma release assay (IGRA results in people living with HIV/AIDS (PLWHA. Methods: We tested 81 PLWHA in the central-west region of Brazil, using the tuberculin skin test and an IGRA. Information on sociodemographic and clinical variables was gathered through the use of questionnaires and from medical records. The association of those variables with indeterminate results was analyzed by calculating the adjusted ORs in a multivariate logistic regression model. Concordance was evaluated by determining the kappa statistic. Results: Among the 81 patients evaluated, the tuberculin skin test results were positive in 18 (22.2% of the patients, and the IGRA results were positive in 10 (12.3%, with a kappa of 0.62. The IGRA results were indeterminate in 22 (27.1% of the patients (95% CI: 17.8-38.1%. The odds of obtaining indeterminate results were significantly higher in smokers (adjusted OR = 6.0; 95% CI: 1.4-26.7 and in samples stored for less than 35 days (adjusted OR = 14.0; 95% CI: 3.1-64.2. Patients with advanced immunosuppression (CD4+ T-cell count < 200 cells/mm3 were at a higher risk for indeterminate results (OR adjusted for smoking and inadequate duration of sample storage = 4.7; 95% CI: 0.91-24.0, although the difference was not significant. Conclusions: The high prevalence of indeterminate results can be a major limitation for the routine use of IGRAs in PLWHA. The need to repeat the test increases its costs and should be taken into account in cost-effectiveness studies. The processing of samples can significantly alter the results.

  5. Executive Summary of the Guidelines for the Use of interferon-gamma Release Assays in the Diagnosis of Tuberculosis Infection.

    Science.gov (United States)

    Santin, Miguel; García-García, José-María; Rigau, David; Altet, Neus; Anibarro, Luis; Casas, Irma; Díez, Nuria; García-Gasalla, Mercedes; Martínez-Lacasa, Xavier; Penas, Antón; Pérez-Escolano, Elvira; Sánchez, Francisca; Domínguez, José

    2016-09-01

    Interferon-gamma release assays are widely used for the diagnosis of tuberculosis infection in Spain. However, there is no consensus on their application in specific clinical scenarios. To develop a guide-line for their use, a panel of experts comprising specialists in infectious diseases, respiratory diseases, microbiology, pediatrics and preventive medicine, together with a methodologist, conducted a systematic literature search, summarized the findings, rated the quality of the evidence, and formulated recommendations following the Grading of Recommendations of Assessment Development and Evaluations methodology. This document provides evidence-based guidance on the use of interferon-gamma release assays for the diagnosis of tuberculosis infection in patients at risk of tuberculosis or suspected of having active disease. The guidelines will be applicable to specialist and primary care, and public health. Copyright © 2016 SEPAR. Publicado por Elsevier España, S.L.U. All rights reserved.

  6. Serial interferon-gamma release assays during treatment of active tuberculosis in young adults

    Directory of Open Access Journals (Sweden)

    Lee Choon-Taek

    2010-10-01

    Full Text Available Abstract Background The role of interferon-γ release assay (IGRA in monitoring responses to anti-tuberculosis (TB treatment is not clear. We evaluated the results of the QuantiFERON-TB Gold In-tube (QFT-GIT assay over time during the anti-TB treatment of adults with no underlying disease. Methods We enrolled soldiers who were newly diagnosed with active TB and admitted to the central referral military hospital in South Korea between May 1, 2008 and September 30, 2009. For each participant, we preformed QFT-GIT assay before treatment (baseline and at 1, 3, and 6 months after initiating anti-TB medication. Results Of 67 eligible patients, 59 (88.1% completed the study protocol. All participants were males who were human immunodeficiency virus (HIV-negative and had no chronic diseases. Their median age was 21 years (range, 20-48. Initially, 57 (96.6% patients had positive QFT-GIT results, and 53 (89.8%, 42 (71.2%, and 39 (66.1% had positive QFT-GIT results at 1, 3, and 6 months, respectively. The IFN-γ level at baseline was 5.31 ± 5.34 IU/ml, and the levels at 1, 3, and 6 months were 3.95 ± 4.30, 1.82 ± 2.14, and 1.50 ± 2.12 IU/ml, respectively. All patients had clinical and radiologic improvements after treatment and were cured. A lower IFN-γ level, C-reactive protein ≥ 3 mg/dl, and the presence of fever (≥ 38.3°C at diagnosis were associated with negative reversion of the QFT-GIT assay. Conclusion Although the IFN-γ level measured by QFT-GIT assay decreased after successful anti-TB treatment in most participants, less than half of them exhibited QFT-GIT reversion. Thus, the reversion to negativity of the QFT-GIT assay may not be a good surrogate for treatment response in otherwise healthy young patients with TB.

  7. Interferon-gamma release assay and Rifampicin therapy for household contacts of tuberculosis.

    Science.gov (United States)

    Wang, Jann-Yuan; Shu, Chin-Chung; Lee, Chih-Hsin; Yu, Chong-Jen; Lee, Li-Na; Yang, Pan-Chyr

    2012-03-01

    Longitudinal studies in household contacts to identify subgroups at risk of active tuberculosis are lacking. Household contacts of pulmonary tuberculosis patients were prospectively enrolled to receive chest radiography, sputum studies, and T-SPOT.TB assay at initial visit. Repeat examinations every 6 months for 3 years, and 4-month rifampin preventive therapy for T-SPOT.TB-positive contacts were provided. We investigated factors predicting T-SPOT.TB-positivity and active pulmonary tuberculosis. 583 contacts were enrolled with a follow-up duration of 20.7 ± 9.4 months. 176 (30.2%) were T-SPOT.TB-positive initially and 32 (18.2%) of them received preventive therapy. Old age, living in the same room/house with the index case, the index case having a high smear grade (3+ ∼ 4+) and pulmonary cavitation were associated with T-SPOT.TB-positivity. Active tuberculosis developed in 9 T-SPOT.TB-positive contacts; risk factors included T-SPOT.TB-positivity without preventive therapy, living in the same room, and the index case being ≤50 years or female. 108 (61.4%) T-SPOT.TB-positive contacts had repeat examinations. Forty-five had T-SPOT.TB reversion and none of them developed active tuberculosis. Household contacts who are T-SPOT.TB-positive and live in the same room as the index case are at risk of active tuberculosis and require preventive therapy and close follow-up. Copyright © 2011 The British Infection Association. Published by Elsevier Ltd. All rights reserved.

  8. The role of interferon gamma release assays in the monitoring of response to anti-tuberculosis treatment in children.

    Science.gov (United States)

    Shaik, Junaid; Pillay, Manormoney; Jeena, Prakash

    2014-09-01

    Successful control of childhood TB requires early diagnosis, effective chemotherapy and a method of evaluating the response to therapy. Identification of suitable biomarkers that predict the response to anti-TB therapy may allow the duration of treatment to be shortened. The majority of biomarker studies in paediatric TB have focused on the role of T cell-based interferon-gamma (IFN-γ) release assays (IGRAs) in the diagnosis of either latent or active disease. Little has been published on the role of IGRAs in the monitoring response to therapy in children. We reviewed the available literature to ascertain the value of IGRAs in the monitoring of response to anti-TB therapy in children. We explored the results of the few studies that have investigated the role of IGRAs as markers of response to anti-TB treatment in children. We conclude that the role of IGRAs as surrogate markers appears promising. Robust clinical trials are, however, needed to entrench the value of IGRAs as surrogate biomarkers of response to anti-TB therapy in children. Copyright © 2013 Elsevier Ltd. All rights reserved.

  9. Private sector tuberculosis prevention in the US: Characteristics associated with interferon-gamma release assay or tuberculin skin testing.

    Science.gov (United States)

    Stockbridge, Erica L; Miller, Thaddeus L; Carlson, Erin K; Ho, Christine

    2018-01-01

    To determine whether latent tuberculosis infection risk factors are associated with an increased likelihood of latent tuberculosis infection testing in the US private healthcare sector. A national sample of medical and pharmacy claims representing services rendered January 2011 through December 2013 for 3,997,986 commercially insured individuals in the US who were 0 to 64 years of age. We used multivariable logistic regression models to determine whether TB/LTBI risk factors were associated with an increased likelihood of Interferon-Gamma Release Assay (IGRA) or Tuberculin Skin Test (TST) testing in the private sector. 4.31% (4.27-4.34%) received at least one TST/IGRA test between 2011 and 2013 while 1.69% (1.67-1.72%) received a TST/IGRA test in 2013. Clinical risk factors associated with a significantly increased likelihood of testing included HIV, immunosuppressive therapy, exposure to tuberculosis, a history of tuberculosis, diabetes, tobacco use, end stage renal disease, and alcohol use disorder. Other significant variables included gender, age, asthma, the state tuberculosis rate, population density, and percent of foreign-born persons in a county. Private sector TST/IGRA testing is not uncommon and testing varies with clinical risk indicators. Thus, the private sector can be a powerful resource in the fight against tuberculosis. Analyses of administrative data can inform how best to leverage private sector healthcare toward tuberculosis prevention activities.

  10. Interferon gamma release assays for the diagnosis of latent TB infection in HIV-infected individuals in a low TB burden country.

    LENUS (Irish Health Repository)

    Cheallaigh, Clíona Ní

    2013-01-01

    Interferon gamma release assays (IGRAs) are used to diagnose latent tuberculosis infection. Two IGRAs are commercially available: the Quantiferon TB Gold In Tube (QFT-IT) and the T-SPOT.TB. There is debate as to which test to use in HIV+ individuals. Previous publications from high TB burden countries have raised concerns that the sensitivity of the QFT-IT assay, but not the T-SPOT.TB, may be impaired in HIV+ individuals with low CD4+ T-cell counts. We sought to compare the tests in a low TB burden setting.

  11. Tuberculin skin testing and treatment modulates interferon-gamma release assay results for latent tuberculosis in migrants.

    Directory of Open Access Journals (Sweden)

    Matthew K O'Shea

    Full Text Available Identifying latent tuberculosis infection (LTBI in people migrating from TB endemic regions to low incidence countries is an important control measure. However, no prospective longitudinal comparisons between diagnostic tests used in such migrant populations are available.To compare commercial interferon (IFN-gamma release assays (IGRAs and the tuberculin skin test (TST for diagnosing LTBI in a migrant population, and the influence of antecedent TST and LTBI treatment on IGRA performance.This cohort study, performed from February to September 2012, assessed longitudinal IGRA and TST responses in Nepalese military recruits recently arrived in the UK. Concomitant T-SPOT.TB, QFT-GIT and TST were performed on day 0, with IGRAs repeated 7 and 200 days later, following treatment for LTBI if necessary.166 Nepalese recruits were prospectively assessed. At entry, 21 individuals were positive by T-SPOT.TB and 8 individuals by QFT-GIT. There was substantial agreement between TST and T-SPOT.TB positives at baseline (71.4% agreement; κ = 0.62; 95% CI:0.44-0.79, but only moderate concordance between positive IGRAs (38.1% agreement; κ = 0.46; 95% CI:0.25-0.67. When reassessed 7 days following TST, numbers of IGRA-positive individuals changed from 8 to 23 for QFT-GIT (p = 0.0074 and from 21 to 23 for T-SPOT.TB (p = 0.87. This resulted in an increase in IGRA concordance to substantial (64.3% agreement; κ = 0.73; 95% CI:0.58-0.88. Thus, in total on day 0 and day 7 after testing, 29 out of 166 participants (17.5% provided a positive IGRA and of these 13 were TST negative. Two hundred days after the study commenced and three months after treatment for LTBI was completed by those who were given chemoprophylaxis, 23 and 21 participants were positive by T-SPOT.TB or QFT-GIT respectively. When individual responses were examined longitudinally within this population 35% of the day 7 QFT-GIT-positive, and 19% T-SPOT.TB-positive individuals, were

  12. Interferon-gamma release assay for the diagnosis of latent tuberculosis infection: A latent-class analysis.

    Directory of Open Access Journals (Sweden)

    Tan N Doan

    Full Text Available Accurate diagnosis and subsequent treatment of latent tuberculosis infection (LTBI is essential for TB elimination. However, the absence of a gold standard test for diagnosing LTBI makes assessment of the true prevalence of LTBI and the accuracy of diagnostic tests challenging. Bayesian latent class models can be used to make inferences about disease prevalence and the sensitivity and specificity of diagnostic tests using data on the concordance between tests. We performed the largest meta-analysis to date aiming to evaluate the performance of tuberculin skin test (TST and interferon-gamma release assays (IGRAs for LTBI diagnosis in various patient populations using Bayesian latent class modelling.Systematic search of PubMeb, Embase and African Index Medicus was conducted without date and language restrictions on September 11, 2017 to identify studies that compared the performance of TST and IGRAs for LTBI diagnosis. Two IGRA methods were considered: QuantiFERON-TB Gold In Tube (QFT-GIT and T-SPOT.TB. Studies were included if they reported 2x2 agreement data between TST and QFT-GIT or T-SPOT.TB. A Bayesian latent class model was developed to estimate the sensitivity and specificity of TST and IGRAs in various populations, including immune-competent adults, immune-compromised adults and children. A TST cut-off value of 10 mm was used for immune-competent subjects and 5 mm for immune-compromised individuals.A total of 157 studies were included in the analysis. In immune-competent adults, the sensitivity of TST and QFT-GIT were estimated to be 84% (95% credible interval [CrI] 82-85% and 52% (50-53%, respectively. The specificity of QFT-GIT was 97% (96-97% in non-BCG-vaccinated and 93% (92-94% in BCG-vaccinated immune-competent adults. The estimated figures for TST were 100% (99-100% and 79% (76-82%, respectively. T-SPOT.TB has comparable specificity (97% for both tests and better sensitivity (68% versus 52% than QFT-GIT in immune-competent adults

  13. The impact of HIV infection and CD4 cell count on the performance of an interferon gamma release assay in patients with pulmonary tuberculosis

    DEFF Research Database (Denmark)

    Aabye, Martine G.; Ravn, Pernille; PrayGod, George

    2009-01-01

    pulmonary tuberculosis (PTB) in a TB- and HIV-endemic population and the effect of HIV-infection and CD4 cell count on test performance. METHODOLOGY/PRINCIPAL FINDINGS: 161 patients with sputum culture confirmed PTB were subjected to HIV- and QFT-IT testing and measurement of CD4 cell count. The QFT......BACKGROUND: The performance of the tuberculosis specific Interferon Gamma Release Assays (IGRAs) has not been sufficiently documented in tuberculosis- and HIV-endemic settings. This study evaluated the sensitivity of the QuantiFERON TB-Gold In-Tube (QFT-IT) in patients with culture confirmed...

  14. Tuberculosis screening of new hospital employees: compliance, clearance to work time, and cost using tuberculin skin test and interferon-gamma release assays.

    Science.gov (United States)

    Foster-Chang, Sarah A; Manning, Mary L; Chandler, Laura

    2014-11-01

    Selection of the most suitable test(s) for detection of Mycobacterium tuberculosis (TB) infection should be based on purpose, setting, effectiveness, and cost. Two tests are available to screen for latent TB: the tuberculin skin test (TST) and the more recent interferon-gamma release assays (IGRAs). Based on the administrative, logistic, and technical ease of use, an IGRA trial was initiated by the occupational health department at an urban Veteran's Administration health care facility for TB screening of new employees. As a result, new employees completing the pre-placement process within the organization's designated 14 days increased from 77% to 97%, new employee clearance to work time decreased from 13.18 to 5.91 days, and new employee TB screening costs were reduced by 40%. The IGRA is an acceptable alternative to the TST and has significant potential to improve the process of pre-placement TB screening. Copyright 2014, SLACK Incorporated.

  15. Use of interferon-gamma release assays in a health care worker screening program: experience from a tertiary care centre in the United States.

    Science.gov (United States)

    Joshi, Manish; Monson, Thomas P; Woods, Gail L

    2012-01-01

    Interferon-gamma release assays including the QuantiFERON-TB Gold In-Tube test (QFT-GIT [Cellestis Ltd, Australia]) may be used in place of the tuberculin skin test (TST) in surveillance programs for Mycobacterium tuberculosis infection control. However, data on performance and practicality of the QFT-GIT in such programs for health care workers (HCWs) are limited. To assess the performance, practicality and reversion rate of the QFT-GIT among HCWs at a tertiary health care institution in the United States. Retrospective chart review of HCWs at Central Arkansas Veterans Healthcare System (Arkansas, USA) who underwent QFT-GIT testing as a part of their employee screening between November 1, 2008 and October 31, 2009. QFT-GIT was used to screen 3290 HCWs. The initial QFT-GIT was interpreted as positive for 129 (3.9%) HCWs, negative for 3155 (95.9%) and indeterminate for six (0.2%). Testing with QFT-GIT was repeated in 45 HCWs who had positive results on the initial test. The QFT-GIT reverted to negative in 18 (40.0%) HCWs, all of whom had negative TST status and initial interferon-gamma values of 0.35 IU⁄mL to 2.0 IU⁄mL. The QFT-GIT test is feasible in large health care setting as an alternative to TST for M tuberculosis infection screening in HCWs but is not free from challenges. The major concerns are the high number of positive test results and high reversion rates on repeat testing, illustrating poor short-term reproducibility of positive QFT-GIT test results. These results suggest adopting a borderline zone between interferon-gamma values of 0.35 IU⁄mL to 2.0 IU⁄mL, and cautious clinical interpretation of values in this range.

  16. Effect of Pregnancy on Interferon Gamma Release Assay and Tuberculin Skin Test Detection of Latent TB Infection Among HIV-Infected Women in a High Burden Setting.

    Science.gov (United States)

    LaCourse, Sylvia M; Cranmer, Lisa M; Matemo, Daniel; Kinuthia, John; Richardson, Barbra A; Horne, David J; John-Stewart, Grace

    2017-05-01

    Peripartum immunologic changes may affect latent tuberculosis infection (LTBI) diagnostic performance among HIV-infected women. HIV-infected women were serially tested with tuberculin skin test (TST) and interferon gamma release assay [QuantiFERON TB Gold In-tube (QFT)] in pregnancy and 6 weeks postpartum in Kenya. Prevalence, sensitivity and agreement, and correlates of QFT/TST positivity were assessed. Quantitative QFT mitogen and Mycobacterium tuberculosis antigen (Mtb-Ag) responses were compared by peripartum stage. Incidence of test conversion at 6 weeks postpartum was evaluated in baseline TST-/QFT- women. Among 100 HIV-infected women, median age was 26 years, median CD4 was 555 cells per cubic millimeter, and 88% were on antiretrovirals. More women were QFT+ than TST+ in both pregnancy (35.4% vs. 13.5%, P = 0.001) and postpartum (29.6% vs. 14.8%, P pregnancy vs. postpartum, and specifically among persistently QFT+ women (Mtb-Ag: 3.46 vs. 4.48 IU/mL, P = 0.007). QFT indeterminate rate was higher in pregnancy (16%) compared with postpartum (0%) because of lower mitogen response. QFT identified >2-fold more women with LTBI compared with TST in pregnancy and postpartum. Lower QFT Mtb-Ag and mitogen responses in pregnancy compared with postpartum suggest that pregnancy-associated immunologic changes may influence LTBI test performance.

  17. Use of an Interferon Gamma Release Assay (IGRA) to test T-cell responsiveness to soluble Leishmania infantum antigen in whole blood of dogs from endemic areas.

    Science.gov (United States)

    Zribi, Lilia; El-Goulli, Amel F; Ben-Abid, Meriem; Gharbi, Mohamed; Ben-Sghaier, Ines; Boufaden, Imed; Aoun, Karim; Bouratbine, Aïda

    2017-11-15

    Interferon-Gamma (IFN-γ) Release Assays (IGRAs) are easy tests that allow rapid screening of primed memory T-cells immunity in response to antigen. The aim of this study was to use IGRA to assess IFN-γ release in response to Soluble Leishmania infantum antigen (SLA) in whole blood of dogs living in endemic area of visceral leishmaniasis and to interpret IGRA results according to clinical examination, specific anti-Leishmania humoral response and presence of L. infantum DNA in blood. The study was carried out on 56 dogs living in greater Tunis area. Physical examination, quantitative serology and PCR on blood were used to characterize dogs' status in relation to Leishmania infection and disease. IGRA consisted on testing by ELISA for IFN-γ-secretion in whole blood after a 20-h challenge with SLA. PBS and Phytohemagglutinin (PHA) stimulations were used as controls. Four groups of dogs were characterized: 31 were negative by both serology and PCR, two had doubtful serology, 10 presented no to mild clinical signs but low antibodies levels and 13 were affected by Canine Leishmaniasis (CanL). In seronegative dogs, IGRA was little contributory in 4 puppies (age dogs (median age=72months, IQR: 45-84 months) that didn't respond to PHA stimulation, IGRA was negative in 19 and positive in three animals with lymph node enlargement. In dogs with doubtful serology, IGRA was positive in one dog and negative in the other. In infected dogs with no to mild clinical signs, one dog exhibited high level of IFN-γ in absence of antigenic stimulation and all the other were positive by IGRA. CanL dogs showed variable IGRA results. Negative IGRAs (n=4) were shown in animals with the highest parasitic burden whereas positive IGRAs (n=5) were shown in dogs with negative PCR or low parasitic load. The 4 remaining dogs either didn't respond to PHA (n=2) or showed non-specific secretion in PBS tube (n=2). The results of this study showed that IGRA is a useful new tool that can assess

  18. Screening of latent tuberculosis infection among health care workers working in Hajj pilgrimage area in Saudi Arabia, using interferon gamma release assay and tuberculin skin test.

    Science.gov (United States)

    Bukhary, Zakeya A; Amer, Soliman M; Emara, Magdy M; Abdalla, Mohammad E; Ali, Sahar A

    2018-01-01

    Interferon gamma release assays (IGRA) is highly specific for Mycobacterium tuberculosis and is the preferred test in BCG-vaccinated individuals. The few studies that have screened health care workers (HCWs) in Saudi Arabia for latent tuberculosis infection (LTBI) using IGRA have varied in agreement with the traditional tuberculin skin test (TST). Assess the prevalence of LTBI among HCWs working in the Hajj pilgrimage using IGRA and TST and measuring their agreement. Cross-sectional prospective. Multiple non-tertiary care hospitals. HCWs who worked during the Hajj pilgrimage in Saudi Arabia in December 2015. Data was collected by standarized questionnaire. Samples were drawn and analyzed by standard methods. The prevalence of LTBI among HCW and the agreement by kappa statistic between QFT-GIT and TST. 520 subjects. Nurses accounted for 30.7% of the sample and physicians, 19.2%. The majority were BCG vaccinated (98.5%). There were a total of 56 positive by QFT-GIT and the LTBI rate was 10.8%. In 50 QFT positive/476 TST negative the LTBI rate was 10.5% in discordant tests, and in 6 QFT positive/44 TST positive it was 13.6% in concordant tests. The overall agreement between both tests was poor-83% and kappa was 0.02. LTBI prevalence was associated with longer employment (13.1 [9.2] years). The QFT-GIT positive test was significantly higher in physicians (P=.02) and in HCWs working in chest hospitals 16/76 (21.05%) (P=.001). Agreement between the tests was poor. QFT-GIT detected LTBI when TST was negative in HCWs who had a history of close contact with TB patients. A second step TST was not feasible within 2-3 weeks. None.

  19. Comparison of interferon {gamma} release assays and conventional screening tests before tumour necrosis factor {alpha} blockade in patients with inflammatory arthritis.

    LENUS (Irish Health Repository)

    Martin, J

    2012-02-01

    OBJECTIVE: To compare the performance of two interferon gamma release assays (IGRAs) and conventional screening tests in patients with inflammatory arthritis undergoing screening for latent tuberculosis infection (LTBI) before treatment with anti-tumour necrosis factor alpha (anti-TNFalpha) compounds. METHODS: Successive patients were subjected to conventional LTBI screening, including a tuberculin skin test (TST). The T-SPOT.TB test was performed on all patients and the QuantiFERON-TB Gold test was performed on a large subset. The results of the IGRAs were compared with the results of conventional screening tests. RESULTS: A total 150 patients were evaluated. The majority (57.9%) had rheumatoid arthritis. Previous vaccination with Bacille Calmette-Guerin was confirmed in 82% of patients. No patient had received prior anti-TB treatment. A total of 57 patients (38.0%) had at least one positive conventional risk factor. In contrast, an unequivocally positive T-SPOT.TB test was seen in only 14\\/143 (9.8%). There was 98.2% agreement between the two IGRAs. Statistically significant associations were found between each of the IGRAs and both TST and risk history, but not chest x-ray (CXR). A positive IGRA result was significantly associated with increased age. TB was not reactivated in any patient during the follow-up period. Interpretation: This study suggests that IGRAs may be useful when screening for LTBI before anti-TNFalpha therapy in patients with immune-mediated inflammatory diseases. The observations reported here also highlight the inadequate performance of CXR as a marker of LTBI.

  20. Evaluation of the prognostic value of IFN-gamma release assay and tuberculin skin test in household contacts of infectious tuberculosis cases in Senegal.

    Directory of Open Access Journals (Sweden)

    Christian Lienhardt

    2010-05-01

    Full Text Available Chemoprophylaxis of contacts of infectious tuberculosis (TB cases is recommended for TB control, particularly in endemic countries, but is hampered by the difficulty to diagnose latent TB infection (LTBI, classically assessed through response to the Tuberculin Skin Test (TST. Interferon-gamma release assays (IGRA are proposed new tools to diagnose LTBI, but there are limited data on their ability to predict the development of active TB disease. To address this, we investigated the response to TST and IGRA in household contacts of infectious TB cases in a TB high-burden country and the potential correlation with development of TB.Prospective household contacts study conducted in two health centres in Dakar, Senegal. A total of 2679 household contacts of 206 newly detected smear and/or culture positive index TB cases aged 18 years or greater were identified A TST was performed in each contact and an ESAT6/CFP10 ELISPOT assay performed in a random sample of those. Contacts were followed-up for 24 months. TB was diagnosed in 52 contacts, an incidence rate of 9.27/1000 person-years. In univariable analysis, the presence of positive TST (> or = 10 mm and ELISPOT (>32 SFC/million PBMC responses at baseline were associated with active TB during follow-up: Rate Ratio [RR] = 2.32 (95%CI:1.12-4.84 and RR = 2.09 (95%CI:0.83-5.31, respectively. After adjustment for age, sex and proximity to index case, adjusted RRs were 1.51 (95%CI:0.71-3.19 and 1.98 (95%CI:0.77-5.09, respectively. Restricting analysis to the 40 microbiologically confirmed cases, the adjusted RR for positive ELISPOT was 3.61 (95%CI:1.03-12.65. The median ELISPOT response in contacts who developed TB was 5-fold greater than in those who did not develop TB (p = 0.02.TST and IGRAs are markers of a contact of the immune system with tubercle bacilli. In a TB endemic area, a high ELISPOT response may reflect increased bacterial replication that may subsequently be associated with development of TB

  1. Interferon Gamma Release Assay versus Tuberculin Skin Testing among Healthcare Workers of Highly Diverse Origin in a Moderate Tuberculosis Burden Country.

    Directory of Open Access Journals (Sweden)

    Sahal Al Hajoj

    Full Text Available Health care workers (HCW's are always at an increased risk of contracting tuberculosis (TB infection. In Saudi Arabia, Interferon Gamma Release Assay (IGRA has not been evaluated as a screening tool for latent TB infection (LTBI among HCW's considering their high demographic diversity. During February 2012 to January 2015 a cross sectional study has been conducted in a tertiary care center with maximum demographically diverse staff population in the capital city-Riyadh. After a short interview and consenting, all the candidates were subjected to tuberculin skin test (TST and QuantiFERON TB gold In-tube test (QFT. A logistic regression analysis was carried out for establishing the associations between putative risk factors and the diagnostic tests. The candidates were classified according to geographical origin and a detailed analysis was conducted on the impact of their origin towards the results of TST and QFT. Of the 1595 candidates enrolled, 90.6% were BCG vaccinated, female (67.9% and mainly nurses (53.2%. Candidates with high risk of suspected or confirmed TB patient exposure were 56.1% and 76.5% of them had <10 year's work experience. TST positivity was observed in 503 (31.5% candidates, while QFT was positive among 399 (25%. Majority of the candidates were non-Saudi (83% and predominantly (52.4% from Western Pacific region. Concordant results were obtained in 14.2% of positive cases and 57.7% negative cases. The disagreements between the two tests were relatively high (kappa co-efficient-0.312±0.026, p value- <0.00001 as TST positive/QFT negative discordance was 54.8% while TST negative/QFT positive discordance was 15.7%. Age of the candidates, BCG vaccination, and South East Asian origin were associated with TST positivity while Occupational TB exposure and geographical origin of the candidates were associated with QFT positivity. A regular follow up on recently TST converted candidates showed no progression to active TB. The putative

  2. Concordancia de las pruebas de tuberculina e Interferón gamma en población reclusa Concordance of tuberculin tests and Interferon gamma release assays in the prison population

    Directory of Open Access Journals (Sweden)

    A. Marco Mouriño

    2011-06-01

    Full Text Available Objetivos: Estudiar en población penitenciaria la concordancia de la prueba de la tuberculina (PT y las pruebas de interferón gamma (IFG. Material y métodos: Estudio prospectivo realizado en una prisión en mayo-junio de 2009. Se estudian los ingresos sin antecedente de tuberculosis (TB o con PT previa negativa o no realizada. Se realizó IDR de Mantoux (positivo ³ 10 mm y extracción sanguínea para prueba de IFG (QuantiFERON®-TB Gold. En los infectados, se realizó despistaje de TB. Se pasó un cuestionario y se solicitó consentimiento informado. El estudio fue aprobado por un Comité ético ajeno a instituciones penitenciarias. La concordancia entre PT e IFG se basó en el índice Kappa. Resultados: Se incluyeron 181 casos. El 62% eran extranjeros, el 17% vacunados por BCG, el 8,4% UDI y el 4% VIH+. En los extranjeros había más vacunados, menos UDI y menos infectados por VIH que en autóctonos (p=0,02, p=0,02, y p=0,01, respectivamente. La PT fue positiva en el 24% y la IFG en el 26%. Hubo información de ambas en 149 (82% casos. El 15,8% fueron discordantes. El índice Kappa fue de 0,6 (0,4-0,7. La concordancia varió según subgrupos, siendo mayor en autóctonos (kappa= 0,8 y menor en vacunados (kappa=0,4 e inmigrantes (kappa=0,5. Conclusión: La concordancia global fue moderada-buena, pero en vacunados e inmigrantes fue menor. El nivel de discordancia aconseja ampliar el estudio, así como evaluar que prueba predice mejor el riesgo de progresión a TB y el coste-beneficio de ambas en la población reclusa de nuestro país.Objective: To study the agreement of Tuberculin Skin Tests (TST and Interferon Gamma Release Assays (IGRA when screening tuberculosis infection amongst inmates recently admitted to prison. Materials and methods: Prospective study conducted in a prison during the months of May and June 2009. Inmates without a TB history, with previous TST negatives or without prior TSTs were included. Participants signed an

  3. Evaluation of the performance of two tuberculosis interferon gamma release assays (IGRA-ELISA and T-SPOT.TB) for diagnosing Mycobacterium tuberculosis infection.

    Science.gov (United States)

    Wang, Linchuan; Tian, Xu-Dong; Yu, Yan; Chen, Wei

    2018-04-01

    The IGRA-ELISA and T-SPOT.TB are widely used in China. The aim of the study was to evaluate the performance of the two assays in diagnosis Mycobacterium tuberculosis infection. Of the 3727 patients in the study, 204 underwent testing using both the T-SPOT.TB and IGRA-ELISA, 1794 were tested using the T-SPOT.TB only, and 1729 were tested using the IGRA-ELISA only. The positive rate and consistency of the two assays were analyzed, and their sensitivity and specificity for diagnosing active tuberculosis were compared. There were no significant differences in the positive rate between the T-SPOT.TB test (25.8%) and IGRA-ELISA (28.6%), p = .065. The two assays were highly consistent, with a kappa value of 0.852 (p SPOT.TB test were 82.9% (107/129) and 78.6% (1309/1665), respectively, and those of IGRA-ELISA were 81.7% (94/115) and 75.2% (1214/1614), respectively. There were no significant differences in sensitivity (p > .05), but the specificity of the T-SPOT.TB test was slightly higher than that of IGRA-ELISA (p = .023). Both in terms of diagnosing M. tuberculosis infection and ruling out active tuberculosis, the performance of the IGRA-ELISA-a simple, almost labor-free assay that allows simultaneous processing of a very large number of samples-was well-matched with that of T-SPOT.TB test. However, IGRAs cannot be used as the only test to diagnose active tuberculosis. Copyright © 2018 Elsevier B.V. All rights reserved.

  4. The feasibility of the interferon gamma release assay and predictors of discordance with the tuberculin skin test for the diagnosis of latent tuberculosis infection in a remote Aboriginal community.

    Directory of Open Access Journals (Sweden)

    Gonzalo G Alvarez

    Full Text Available The tuberculin skin test (TST is the standard test used to screen for latent TB infection (LTBI in the northern Canadian territory of Nunavut. Interferon gamma release assays (IGRA are T cell blood-based assays to diagnose LTBI. The Bacillus Calmette-Guerin (BCG vaccine is part of the routine immunization schedule in Nunavut. The objective of this study was to test the feasibility, and predictors of discordance between the Tuberculin Skin Test (TST and the IGRA assay in a medically under-serviced remote arctic Aboriginal population.Both the TST and QuantiFERON-TB Gold (Qiagen group IGRA tests were offered to people in their homes as part of a public health campaign aimed at high TB risk residential areas in Iqaluit, Nunavut, Canada. Feasibility was measured by the capacity of the staff to do the test successfully as measured by the proportion of results obtained.In this population of predominantly young Inuit who were mostly BCG vaccinated, the use of IGRA for the diagnosis of LTBI was feasible. IGRA testing resulted in more available test results reaching patients (95.6% vs 90.9% p = 0.02 but took longer (median 8 days (IGRA vs 2 days (TST, p value < 0.0001. 44/256 participants (17.2% had discordant results. Multivariable regression analysis suggested that discordant results were most likely to have received multiple BCG vaccinations (RR 20.03, 95% CI, 3.94-101.82, followed by BCG given post infancy (RR 8.13, 95% CI, 2.54-26.03 and then to a lesser degree when BCG was given in infancy (RR 6.43, 95% CI, 1.72-24.85.IGRA is feasible in Iqaluit, Nunavut, a remote Arctic community. IGRA testing results in more test results available to patients compared to TST. This test could result in fewer patients requiring latent TB treatment among those previously vaccinated with BCG in a region with limited public health human resources.

  5. Evaluation of gamma radiation induced genetic damage in the fish Cyprinus carpio using comet assay

    International Nuclear Information System (INIS)

    Praveen Kumar, M.K.; Shyama, S.K.; Bhagat, S.S.; Chaubey, R.C.

    2013-01-01

    Radionuclides released from various sources including the industries, as well as, accidental release during a nuclear disaster can contaminate inland water bodies. Suitable bio-monitoring methods/biomarkers are the need of the day to assess the impact of high/low levels of radiation exposure in aquatic environment. Fishes are very important as a group of ecologically and commercially important non-human biota and are often used as a bioindicators of aquatic pollution. Present work was carried out to assess the genotoxic effect of gamma radiation on fresh water fish Cyprinus carpio (common carp) in vivo using comet assay. Fishes were irradiated with 2, 4, 6, 8 and 10 Gy of gamma rays using a teletherapy machine and comet assay was performed on nucleated erythrocytes after 24, 48 and 72 h of irradiation . A significant increase in % tail DNA was observed at all the doses of gamma radiation as compared to controls indicating radiation induced DNA damage in a dose-dependent manner. Maximum % tail DNA was observed at 24 h which gradually declined till 72 h, in a time-dependent manner. This decrease in damage may indicate repair of the damaged DNA and or loss of heavily damaged cells, over a period of time. The study reveals that the comet assay may be used as a sensitive and rapid method to detect genotoxicity of gamma radiation and other environmental pollutants in sentinel species. (author)

  6. Evaluation of gamma spectroscopy gauge for uranium-plutonium assay

    International Nuclear Information System (INIS)

    Notea, A.; Segal, Y.

    1975-01-01

    A procedure is presented for the characterization of a gamma passive method for nondestructive analysis of nuclear fuel. The approach provides an organized and systematic way for optimizing the assay system. The key function is the relative resolving power defined as the smallest relative change in the Quantity of radionuclide measured, that may be detected within a certain confidence level. This function is derived for nuclear fuel employing a model based on empirical parameters. The ability to detect changes in fuels of binary and trinary compositions with a 50 cc Ge(Li) at a 1 min counting period is discussed. As an example to a binary composition, an enriched uranium fuel was considered. The 185 keV and 1001 keV gamma lines are used for the assay of 235 U and 238 U respectively. As a trinary composition a plutonium-containing gamma line. The interference of the high energy lines is carefully analyzed, and numerical results are presented. For both cases the range of measurement under specific accuracy demands is determined. The approach described is suitable also for evaluation of other passive as well as active assay methods. (author)

  7. 21 CFR 864.7040 - Adenosine triphosphate release assay.

    Science.gov (United States)

    2010-04-01

    ... 21 Food and Drugs 8 2010-04-01 2010-04-01 false Adenosine triphosphate release assay. 864.7040 Section 864.7040 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) MEDICAL DEVICES HEMATOLOGY AND PATHOLOGY DEVICES Hematology Kits and Packages § 864.7040...

  8. IP-10 release assays in the diagnosis of tuberculosis infection

    DEFF Research Database (Denmark)

    Ruhwald, Morten; Aabye, Martine G; Ravn, Pernille

    2012-01-01

    The current state-of-the-art tests for infection with Mycobacterium tuberculosis - the IFN-γ release assays - rely on accurate measurement of the cytokine IFN-γ. Many other potential biomarkers are expressed in concert with IFN-γ, and IP-10 in particular has shown promising results. IP-10...

  9. Fine gamma spectrometry and release measurements

    International Nuclear Information System (INIS)

    Bovard, P.; Philippot, J.Cl.

    1978-01-01

    The growing number of nuclear facilities and a stricter interpretation of the fundamentals of radiological protection create an ever greater need for more thorough knowledge of releases to the environment. The measurement of releases and effluents involves study of a fairly large mixture of radionuclides. The methods of processing and interpreting Ge(Li) spectra that are described prove highly effective whenever the spectral topology is complex. The data obtained on the composition of nuclide mixtures can be very useful in the event of disputes or litigation. The four stages of metrology involved are discussed, namely measurement, spectral processing, exact definition of transition energies, and final interpretation. Particular stress is placed on the originality of the energy calibration procedure, which avoids the use of an external standard and is based on nuclear equations relating the spectral line energies; very high line definition accuracy is obtained in this way (better than 100eV on average for all the spectral lines present). Some examples of the technique used are given but no details are presented of the conditions and quality of sampling, or the implications for radiological protection of their results. (author)

  10. Assay of plutonium contaminated waste by gamma spectrometry

    International Nuclear Information System (INIS)

    Adsley, I.; Bull, R.; Davies, M.; Green, M.

    2011-01-01

    The extreme toxicity of plutonium necessitates the segregation of plutonium contaminated materials (PCM) with extremely small (sub-μg) levels of contamination. The driver to measure accurately these small quantities of plutonium within (relatively) large volumes of waste is (in part) financial. In particular the cost of disposal (per unit volume) rises steeply with increasing waste-category. Within the UK, there has been a historical reluctance to use low energy gamma radiation to sentence PCM because of the potential for self attenuation by dense materials. This is unfortunate because the low-energy gamma radiation from PCM offers the only practicable technique for segregating PCM within the various Low Level Waste (LLW) (>0.4Bq/g) and sub-LLW categories. Whilst passive neutron counting techniques have proved successful for assay of waste well into the Intermediate Level Waste (ILW) (>100Bq/g) category, a cursory study reveals that these techniques are barely capable of detecting mg quantities of plutonium -- let alone the sub-μg quantities present in LLW. This paper considers the use of two types of gamma detector for assay of PCM: the thin sodium iodide FIDLER (Field Instrument for the Detection of Low Energy Radiation) and the HPGe (High Purity Germanium) detector. Systems utilising these two types of detector can provide complementary information. FIDLER measurements are conducted by careful, local, systematic monitoring of surfaces. By contrast a HPGe detector can be used to monitor entire walls, or even rooms, in one measurement. Thus, a HPGe detector placed in the centre of room (from which any radioactive hot-spots have previously been removed) could be used to demonstrate that the average activity remaining close to the surface of the walls/floor/ceiling is below a given limit. The Monte Carlo Code MCNP 1 has been used to model both FIDLER probe and HPGe detector in the measurement geometries described above. The MCNP simulations have been validated

  11. Development of a lion-specific interferon-gamma assay.

    Science.gov (United States)

    Maas, M; van Kooten, P J S; Schreuder, J; Morar, D; Tijhaar, E; Michel, A L; Rutten, V P M G

    2012-10-15

    The ongoing spread of bovine tuberculosis (BTB) in African free-ranging lion populations, for example in the Kruger National Park, raises the need for diagnostic assays for BTB in lions. These, in addition, would be highly relevant for zoological gardens worldwide that want to determine the BTB status of their lions, e.g. for translocations. The present study concerns the development of a lion-specific IFN-γ assay, following the production and characterization of monoclonal antibodies specific for lion interferon-gamma (IFN-γ). Recombinant lion IFN-γ (rLIFN-γ) was produced in mammalian cells and used to immunize mice to establish hybridoma cell lines producing monoclonal antibodies. These were used to develop a sensitive, lion IFN-γ-specific capture ELISA, able to detect rLIFN-γ to the level of 160 pg/ml. Recognition of native lion IFN-γ was shown in an initial assessment of supernatants of mitogen stimulated whole blood cultures of 11 known BTB-negative lions. In conclusion, the capture ELISA shows potential as a diagnostic assay for bovine tuberculosis in lions. Preliminary results also indicate the possible use of the test for other (feline) species. Copyright © 2012 Elsevier B.V. All rights reserved.

  12. Gamma aminobutyric acid radioreceptor assay: a confirmatory quantitative assay for toxaphene in environmental and biological samples

    International Nuclear Information System (INIS)

    Saleh, M.A.; Blancato, J.N.

    1993-01-01

    Toxaphene is a complex mixture of polychlorinated monoterpenes, and was found to be acutely and chronically toxic to aquatic and wild life and posed a carcinogenic risk to humans before its ban in 1982. However, it is still found in the environment due to its relative persistence with an estimated half life time of about 10 years in soils. Toxaphenes neurotoxicity is attributed to a few isomers with a mode of action through binding to the chloride channel of the gamma-aminobutyric acid (GABA) receptor ionophore complex. [ 35 S] tertiary butylbicyclophosphorothionate (TBPS) with specific activity higher than 60 Ci/mmole has a high binding affinity to the same sites and is now commercially available and can be used to label the GABA receptor for the development of radioreceptor assay technique. The GABA receptor was prepared by a sequence of ultra centrifugation and dialysis of mammalian (rats, cows, catfish and goats) brain homogenates. The receptor is then labeled with [ 35 S] TBPS and the assay was conducted by measuring the displacement of radioactivity following incubation with the sample containing the analytes. The assay is fast, sensitive and requires very little or no sample preparation prior to the analysis. (Author)

  13. A study of the 51Cr release assay system in micro-method

    International Nuclear Information System (INIS)

    Kiya, Katsuzo; Harada, Kiyoshi; Uozumi, Tohru; Toge, Tetsuya; Hattori, Takao.

    1981-01-01

    Conditions of 51 Cr release assay in microculture were investigated to measure the natural cytotoxic (NC) activity of mouse spleen cells. Malignant glioma (MG) cells of C57BL/6 mouse, induced by 20-methylcholanthrene, were labeled with Na 2 51 CrO 4 . Spleen cells collected from the same mouse strain were suspended in Eagle's MEM. Labeled MG cells and spleen cells were incubated for several hours in a CO 2 incubator. Then the activity of the supernatant was measured by an automatic gamma counter. The optimum conditions of 51 Cr release assay in micro-culture were, (1) number of the target cells: 5 x 10 3 / well (2) FCS concentration: 10% (3) E/T ratio: less than 100 : 1, 50 : 1 was possible (4) incubation time: 15 hours. The number of the target cells at labeling incubation was set to 2 x 10 6 /ml. Though the natural release of 51 Cr was not effected by the viability of the target cells, it was suggested that the NC activity was dependent on the viability of both cells, target and effector cells. (Tsunoda, M.)

  14. Study of the /sup 51/Cr release assay system in micro-method

    Energy Technology Data Exchange (ETDEWEB)

    Kiya, K.; Harada, K.; Uozumi, T. (Hiroshima Univ. (Japan). School of Medicine); Toge, T.; Hattori, T.

    1981-05-01

    Conditions of /sup 51/Cr release assay in microculture were investigated to measure the natural cytotoxic (NC) activity of mouse spleen cells. Malignant glioma (MG) cells of C57BL/6 mouse, induced by 20-methylcholanthrene, were labeled with Na/sub 2//sup 51/CrO/sub 4/. Spleen cells collected from the same mouse strain were suspended in Eagle's MEM. Labeled MG cells and spleen cells were incubated for several hours in a CO/sub 2/ incubator. Then the activity of the supernatant was measured by an automatic gamma counter. The optimum conditions of /sup 51/Cr release assay in micro-culture were, (1) number of the target cells: 5 x 10/sup 3// well (2) FCS concentration: 10% (3) E/T ratio: less than 100 : 1, 50 : 1 was possible (4) incubation time: 15 hours. The number of the target cells at labeling incubation was set to 2 x 10/sup 6//ml. Though the natural release of /sup 51/Cr was not effected by the viability of the target cells, it was suggested that the NC activity was dependent on the viability of both cells, target and effector cells.

  15. Marrow stem cell release in the autorepopulation assay

    Energy Technology Data Exchange (ETDEWEB)

    Maloney, M A; Patt, H M [California Univ., San Francisco (USA). Lab. of Radiobiology

    1978-01-01

    The early migration of stem cells from shielded marrow to an irradiated spleen has been re-evaluated, and the findings have been compared with the results of earlier studies. The composite data reveal a constant rate during the first 24 h after irradiation, with a slope of 1.6 cells per h and an intercept of 2.4. The positive intercept is interpreted to signify an immediate brief perturbation of CFU/sub s/ release. The low concentration of CFU/sub s/ in the bloodstream, despite their continuous migration from the shielded marrow, is indicative of a rapid, and probably greatly increased, blood turnover. Despite the constancy of stem cell seeding, it is not yet possible to determine whether the rate of stem cell release is different in shielded marrow than in normal marrow. The resolution of this question requires more precise information about spleen seeding efficiency in the autorepopulation assay and about the normal turnover rate of stem cells in the bloodstream.

  16. Quantitative radiological characterization of waste. Integration of gamma spectrometry and passive/active neutron assay

    Energy Technology Data Exchange (ETDEWEB)

    Simone, Gianluca; Mauro, Egidio; Gagliardi, Filippo; Gorello, Edoardo [Nucleco S.p.A., Rome (Italy)

    2016-06-15

    The radiological characterization of drums through Non-Destructive Assay (NDA) techniques commonly relies on gamma spectrometry. This paper introduces the procedure developed in Nucleco for the NDA radiological characterization of drums when the presence of Special Nuclear Material (SNM) is expected/observed. The procedure is based on the integration of a gamma spectrometry in SGS mode (Segmented Gamma Scanner) and a passive/active neutron assay. The application of this procedure is discussed on a real case of drums. The extension of the integration procedure to other gamma spectrometry systems is also discussed.

  17. Are 0.1%-accurate gamma-ray assays possible for 235U solutions

    International Nuclear Information System (INIS)

    Parker, J.L.

    1983-01-01

    The factors influencing the accuracy of passive gamma-ray assay of uniform, homogeneous solution samples have been studied in some detail, particularly for the assay of 235 U in uranium solutions. Factors considered are the overall long-term electronic stability, the information losses caused by the rate-related electronic processes of pulse pileup and dead-time, and the self-attenuation of gamma rays within the samples. Both experimental and computational studies indicate that gamma-ray assay procedures for solution samples of moderate size (from approx. 10 to perhaps a few hundred milliliters) are now capable of accuracies approaching 0.1% in many practical cases

  18. Controlled release fertilizers using superabsorbent hydrogel prepared by gamma radiation

    Energy Technology Data Exchange (ETDEWEB)

    Elbarbary, Ahmed M.; Ghobashy, Mohamed Mohamady [Atomic Energy Authority, Nasr City (Egypt). National Center for Radiation Research and Technology (NCRTT)

    2017-07-01

    Superabsorbent hydrogels (PVP/CMC) based on polyvinylpyrrolidone (PVP)/carboxylmethyl cellulose (CMC) of different copolymer compositions were prepared by gamma radiation. Factors affecting the gel content (%) and the swelling ratio (g/g) of hydrogel such as irradiation dose as well as copolymer composition were investigated. With increasing the CMC content in PVP/CMC hydrogels, increases the swelling and improves the water retention capability. The high swelling ratio was observed at copolymer composition of PVP/CMC (60/40). Fast swelling of the hydrogels was obtained after 20 min. The effect of different fertilizers and buffers of different pH's on equilibrium swelling of hydrogels was investigated. Fertilizers such as urea, monopotassium-phosphate (MPK), and nitrogen-phosphate-potassium (NPK) were loaded onto the hydrogel to supply nitrogen, potassium and phosphorous nutrients. PVP/CMC hydrogels retained 28-36% after 72 h and slow retention was noticed up to 9 days. The swelling of hydrogel in fertilizer solutions is lower than that in water. The hydrogels showed adsorption desorption of fertilizers which governs by slow release property. The release rate of urea is much higher 10 times than that of phosphate. After 3 days, urea released 60%, while phosphate released 10-12%. The applicability of PVP/CMC hydrogels in the agricultural fields shows greater growth effect on zea maize plants. The growth of zea maize plant in soil mixed with PVP/CMC hydrogels loaded fertilizers is greater than untreated soil. The slow release fertilize, the high swelling and the slow water retention behaviors of PVP/CMC hydrogels encourage their use as safer release systems for fertilizers and as soil conditioner in agricultural applications.

  19. Controlled release fertilizers using superabsorbent hydrogel prepared by gamma radiation

    International Nuclear Information System (INIS)

    Elbarbary, Ahmed M.; Ghobashy, Mohamed Mohamady

    2017-01-01

    Superabsorbent hydrogels (PVP/CMC) based on polyvinylpyrrolidone (PVP)/carboxylmethyl cellulose (CMC) of different copolymer compositions were prepared by gamma radiation. Factors affecting the gel content (%) and the swelling ratio (g/g) of hydrogel such as irradiation dose as well as copolymer composition were investigated. With increasing the CMC content in PVP/CMC hydrogels, increases the swelling and improves the water retention capability. The high swelling ratio was observed at copolymer composition of PVP/CMC (60/40). Fast swelling of the hydrogels was obtained after 20 min. The effect of different fertilizers and buffers of different pH's on equilibrium swelling of hydrogels was investigated. Fertilizers such as urea, monopotassium-phosphate (MPK), and nitrogen-phosphate-potassium (NPK) were loaded onto the hydrogel to supply nitrogen, potassium and phosphorous nutrients. PVP/CMC hydrogels retained 28-36% after 72 h and slow retention was noticed up to 9 days. The swelling of hydrogel in fertilizer solutions is lower than that in water. The hydrogels showed adsorption desorption of fertilizers which governs by slow release property. The release rate of urea is much higher 10 times than that of phosphate. After 3 days, urea released 60%, while phosphate released 10-12%. The applicability of PVP/CMC hydrogels in the agricultural fields shows greater growth effect on zea maize plants. The growth of zea maize plant in soil mixed with PVP/CMC hydrogels loaded fertilizers is greater than untreated soil. The slow release fertilize, the high swelling and the slow water retention behaviors of PVP/CMC hydrogels encourage their use as safer release systems for fertilizers and as soil conditioner in agricultural applications.

  20. Isotope release cytotoxicity assay applicable to human tumors: the use of 111-indium

    Energy Technology Data Exchange (ETDEWEB)

    Frost, P; Wiltrout, R; Maciorowski, Z; Rose, N R

    1977-01-01

    We have demonstrated that human tumors can be labelled efficiently with the 111indium-oxine chelate. Subsequently, this isotope can be released by cytotoxic lymphoid cells. Both natural and induced cytotoxicity can be demonstrated utilizing this isotope release method. Because of the slow spontaneous release of 111indium and its efficient labelling of human tumor cells, this isotope release assay can be utilized in long-term cytotoxic assays in the study of human tumor immunology.

  1. Use of the johnin PPD interferon-gamma assay in control of bovine paratuberculosis

    DEFF Research Database (Denmark)

    Jungersen, Gregers; Mikkelsen, Heidi; Grell, Susanne N.

    2012-01-01

    Although the interferon-gamma (IFN-γ) assay for measurements of cell-mediated immune (CMI) responses to paratuberculosis PPD (johnin) has been available for close to 20 years, the assay has not yet emerged as the long desired test to identify infected animals at an early time point. Among other...

  2. Nondestructive assay of TRU waste using gamma-ray active and passive computed tomography

    International Nuclear Information System (INIS)

    Roberson, G.P.; Decman, D.; Martz, H.; Keto, E.R.; Johansson, E.M.

    1995-01-01

    The authors have developed an active and passive computed tomography (A and PCT) scanner for assaying radioactive waste drums. Here they describe the hardware components of their system and the software used for data acquisition, gamma-ray spectroscopy analysis, and image reconstruction. They have measured the performance of the system using ''mock'' waste drums and calibrated radioactive sources. They also describe the results of measurements using this system to assay a real TRU waste drum with relatively low Pu content. The results are compared with X-ray NDE studies of the same TRU waste drum as well as assay results from segmented gamma scanner (SGS) measurements

  3. NO CORRELATION BETWEEN HOST GALAXY METALLICITY AND GAMMA-RAY ENERGY RELEASE FOR LONG-DURATION GAMMA-RAY BURSTS

    International Nuclear Information System (INIS)

    Levesque, Emily M.; Kewley, Lisa J.; Soderberg, Alicia M.; Berger, Edo

    2010-01-01

    We compare the redshifts, host galaxy metallicities, and isotropic (E γ,iso ) and beaming-corrected (E γ ) gamma-ray energy release of 16 long-duration gamma-ray bursts (LGRBs) at z γ,iso , or E γ . These results are at odds with previous theoretical and observational predictions of an inverse correlation between gamma-ray energy release and host metallicity, as well as the standard predictions of metallicity-driven wind effects in stellar evolutionary models. We consider the implications that these results have for LGRB progenitor scenarios, and discuss our current understanding of the role that metallicity plays in the production of LGRBs.

  4. Effect of gamma irradiation on fluoride release and antibacterial activity of resin dental materials

    International Nuclear Information System (INIS)

    Carvalho, Fabiola Galbiatti de; Fucio, Suzana Beatriz Portugal de; Correr-Sobrinho, Lourenco; Pascon, Fernanda Miori; Kantovitz, Kamila Rosamilia; Puppin-Rontani, Regina Maria

    2009-01-01

    This study evaluated the effect of gamma irradiation on fluoride release and antibacterial activity of FluroShield (FS) and Clearfil Protect Bond (CPB). Four groups were formed: G1-FS + gamma; G2-FS without gamma; G3-CPB + gamma; G4-CPB without gamma. For fluoride release analysis, 12 disks of each material were prepared and covered with nail polish, except for one side (50.4 mm 2 area). G1 and G3 were sterilized with a 14.5 KGy dose at 27 deg C for 24 h, while G2 and G4 (controls) were not sterilized and were maintained under the same time and temperature conditions. Fluoride release measurements were made in duplicate (n=6) by an ion specific electrode. The antibacterial activity of the CPB and FS against Streptococcus mutans after gamma sterilization was evaluated by the agar-disc diffusion method. The diameter of the zones of microbial growth inhibition was recorded after 48 h. Data were analyzed statistically by ANOVA and Tukey's test (alpha=5%). Gamma sterilization decreased the fluoride release of FS by approximately 50%, while CPB was not affected. There was no statistically significant difference (p>0.05) in the antibacterial effect of CPB between gamma and non-gamma sterilization groups. FS presented no antibacterial activity. Gamma irradiation decreased the fluoride release of FS, but did not affect the antibacterial activity of the studied materials. (author)

  5. Effect of gamma irradiation on fluoride release and antibacterial activity of resin dental materials

    Energy Technology Data Exchange (ETDEWEB)

    Carvalho, Fabiola Galbiatti de; Fucio, Suzana Beatriz Portugal de; Correr-Sobrinho, Lourenco [Universidade Estadual de Campinas (UNICAMP), Piracicaba, SP (Brazil). Piracicaba Dental School. Dept. of Dental Materials; Pascon, Fernanda Miori; Kantovitz, Kamila Rosamilia; Puppin-Rontani, Regina Maria [Universidade Estadual de Campinas (UNICAMP), Piracicaba, SP (Brazil). Piracicaba Dental School. Dept. of Pedriatric Dentistry], e-mail: rmpuppin@fop.unicamp.br

    2009-07-01

    This study evaluated the effect of gamma irradiation on fluoride release and antibacterial activity of FluroShield (FS) and Clearfil Protect Bond (CPB). Four groups were formed: G1-FS + gamma; G2-FS without gamma; G3-CPB + gamma; G4-CPB without gamma. For fluoride release analysis, 12 disks of each material were prepared and covered with nail polish, except for one side (50.4 mm{sup 2} area). G1 and G3 were sterilized with a 14.5 KGy dose at 27 deg C for 24 h, while G2 and G4 (controls) were not sterilized and were maintained under the same time and temperature conditions. Fluoride release measurements were made in duplicate (n=6) by an ion specific electrode. The antibacterial activity of the CPB and FS against Streptococcus mutans after gamma sterilization was evaluated by the agar-disc diffusion method. The diameter of the zones of microbial growth inhibition was recorded after 48 h. Data were analyzed statistically by ANOVA and Tukey's test (alpha=5%). Gamma sterilization decreased the fluoride release of FS by approximately 50%, while CPB was not affected. There was no statistically significant difference (p>0.05) in the antibacterial effect of CPB between gamma and non-gamma sterilization groups. FS presented no antibacterial activity. Gamma irradiation decreased the fluoride release of FS, but did not affect the antibacterial activity of the studied materials. (author)

  6. Development of a lion-specific interferon-gamma assay

    NARCIS (Netherlands)

    Maas, M.; Kooten, van P.J.S.; Schreuder, J.; Morar, D.; Tijhaar, E.; Michel, A.L.; Rutten, V.P.M.G.

    2012-01-01

    The ongoing spread of bovine tuberculosis (BTB) in African free-ranging lion populations, for example in the Kruger National Park, raises the need for diagnostic assays for BTB in lions. These, in addition, would be highly relevant for zoological gardens worldwide that want to determine the BTB

  7. Standard test method for nondestructive assay of radioactive material by tomographic gamma scanning

    CERN Document Server

    American Society for Testing and Materials. Philadelphia

    2010-01-01

    1.1 This test method describes the nondestructive assay (NDA) of gamma ray emitting radionuclides inside containers using tomographic gamma scanning (TGS). High resolution gamma ray spectroscopy is used to detect and quantify the radionuclides of interest. The attenuation of an external gamma ray transmission source is used to correct the measurement of the emission gamma rays from radionuclides to arrive at a quantitative determination of the radionuclides present in the item. 1.2 The TGS technique covered by the test method may be used to assay scrap or waste material in cans or drums in the 1 to 500 litre volume range. Other items may be assayed as well. 1.3 The test method will cover two implementations of the TGS procedure: (1) Isotope Specific Calibration that uses standards of known radionuclide masses (or activities) to determine system response in a mass (or activity) versus corrected count rate calibration, that applies to only those specific radionuclides for which it is calibrated, and (2) Respo...

  8. Detection of garlic gamma-irradiated by assay comet

    International Nuclear Information System (INIS)

    Moreno Alvarez, Damaris L.; Miranda, Enrique F. Prieto; Carro, Sandra; Iglesias Enrique, Isora; Matos, Wilberto

    2009-01-01

    The garlic samples were irradiated in a facility with 60 Co sources, at absorbed dose values of 0-0,15 kGy. The detection method utilized for the identification of the irradiated garlic was biological comet assay. The samples were classified post-irradiation several times. The irradiated samples showed high strand breaks of DNA exhibiting comets of several forms, while the not irradiated and lower dose samples showed a behavior like round shape and light comets. Significant differences were found for higher absorbed dose values at 0.06 kGy, this absorbed dose value is corresponding with the applied dose value at this food in order to avoid the germination. (author)

  9. Detection of garlic gamma-irradiated by assay comet

    Energy Technology Data Exchange (ETDEWEB)

    Moreno Alvarez, Damaris L.; Miranda, Enrique F. Prieto; Carro, Sandra; Iglesias Enrique, Isora; Matos, Wilberto [Centro de Aplicaciones Tecnologicas y Desarrollo Nuclear (CEADEN), Ciudad de La Habana (Cuba)], e-mail: damaris@ceaden.edu.cu

    2009-07-01

    The garlic samples were irradiated in a facility with {sup 60}Co sources, at absorbed dose values of 0-0,15 kGy. The detection method utilized for the identification of the irradiated garlic was biological comet assay. The samples were classified post-irradiation several times. The irradiated samples showed high strand breaks of DNA exhibiting comets of several forms, while the not irradiated and lower dose samples showed a behavior like round shape and light comets. Significant differences were found for higher absorbed dose values at 0.06 kGy, this absorbed dose value is corresponding with the applied dose value at this food in order to avoid the germination. (author)

  10. Diabetes is associated with lower tuberculosis antigen-specific interferon gamma release in Tanzanian tuberculosis patients and non-tuberculosis controls

    DEFF Research Database (Denmark)

    Faurholt-Jepsen, Daniel; Aabye, Martine Grosos; Jensen, Andreas Vestergaard

    2014-01-01

    in diabetes patients and therefore the validity of interferon gamma release assays (IGRA) may be compromised. The aim of the present study was to assess the association between diabetes and Mycobacterium tuberculosis (Mtb) antigen-specific interferon gamma (IFN-γ) release in a TB endemic area among culture......-confirmed TB patients and non-TB controls. Methods: Culture-confirmed pulmonary TB patients (n = 187) and healthy non-TB neighbourhood controls (n = 190) from Mwanza, Tanzania were tested for the presence of circulating T cells recognizing Mtb antigens using an IGRA. The diabetes status of all participants...

  11. Multi-isotopic gamma-ray assay system for alpha-contaminated waste

    International Nuclear Information System (INIS)

    Close, D.A.; Pratt, J.C.; Caldwell, J.T.; Kunz, W.E.; Schultz, F.J.; Haff, K.W.

    1983-01-01

    The capability of an existing segmented gamma-ray system is being expanded for the analysis of alpha-contaminated waste drums. A cursory assay of 114 transuranic waste drums of 208-l capacity has been made. Analysis of these data indicates a detection limit better than 100 nCi/g of waste for 237 Np/ 233 Pa, 239 Pu, 241 Am, 243 Am/ 239 Np, 60 Co, 125 Sb, 134 137 Cs, and 154 Eu. A pending Code of Federal Regulation (10CFR61) stipulates that the nuclear industry quantify not only its transuranic waste, but also certain beta- and gamma-ray-emitting fission products. An assay system based on gamma-ray spectroscopy is the only system that can meet this requirement for the fission products

  12. A Compton Suppressed Gamma Ray Counter For Radio Assay of Materials

    Science.gov (United States)

    Godfrey, Benjamin

    2016-03-01

    Rare event searches, such as direct dark matter experiments, require materials with ultra-low levels of natural radioactivity. We present a neutron activation analysis (NAA) technique for assaying metals, specifically titanium used for cryostat construction. Earlier attempts at NAA encountered limitations due to bulk activation via (n, p) reactions, which contributed to large continuum backgrounds due to Compton tails. Our method involves a heavy water shielded exposure to minimize (n,p) reactions and a sodium iodide shielded high purity germanium counter for the gamma ray assay. Preliminary results on assays for U/Th/K contamination in titaniumwill be presented.

  13. Ornithogalum virens as a plant assay for beta and gamma radiation effects

    International Nuclear Information System (INIS)

    Herron, V.J.

    1979-01-01

    The purpose of this study was to determine if the monocotyledonous angiosperm, Ornithogalum virens (Quintanilha and Cabral, 1947), could be used in such a biological assay system. After exposing O. virens plants to acute ( 60 Co) and chronic ( 137 Cs) gamma radiation and internal beta radiation ( 32 P), lethality (LD 50 , LD 100 ), growth inhibition, and chromosome aberrations were investigated. The LD 50 and LD 100 for acute gamma radiation were estimated to be between 0.91 to 1.8 krad and less than 3.6 krad, respectively. Though growth inhibition and abnormal growth were observed in the acute and chronic gamma radiation studies, the changes in the growth of the plants were so variable that these parameters were found to be unreliable measures of radiation effects. Chromosome aberrations were a more reliable measure of radiation damage because linear relationships between total aberrations and dose were found for both gamma and beta radiation

  14. Total Measurement Uncertainty for the Plutonium Finishing Plant (PFP) Segmented Gamma Scan Assay System

    CERN Document Server

    Fazzari, D M

    2001-01-01

    This report presents the results of an evaluation of the Total Measurement Uncertainty (TMU) for the Canberra manufactured Segmented Gamma Scanner Assay System (SGSAS) as employed at the Hanford Plutonium Finishing Plant (PFP). In this document, TMU embodies the combined uncertainties due to all of the individual random and systematic sources of measurement uncertainty. It includes uncertainties arising from corrections and factors applied to the analysis of transuranic waste to compensate for inhomogeneities and interferences from the waste matrix and radioactive components. These include uncertainty components for any assumptions contained in the calibration of the system or computation of the data. Uncertainties are propagated at 1 sigma. The final total measurement uncertainty value is reported at the 95% confidence level. The SGSAS is a gamma assay system that is used to assay plutonium and uranium waste. The SGSAS system can be used in a stand-alone mode to perform the NDA characterization of a containe...

  15. The importance of stimulated gamma release from isomers

    International Nuclear Information System (INIS)

    Roberts, H.

    1997-01-01

    The potential applications of the gamma-ray laser are discussed to illustrate the potential benefit of the development of this field of nuclear science, as well as the risks and responsibilities associated with isomer development beyond their current status as nuclear curiosities. The similarities and differences between the development of a gamma-ray laser based on nuclear isomers and the initial development of nuclear science and engineering are compared

  16. Efficiency and attenuation correction factors determination in gamma spectrometric assay of bulk samples using self radiation

    International Nuclear Information System (INIS)

    Haddad, Kh.

    2009-02-01

    Gamma spectrometry forms the most important and capable tool for measuring radioactive materials. Determination of the efficiency and attenuation correction factors is the most tedious problem in the gamma spectrometric assay of bulk samples. A new experimental and easy method for these correction factors determination using self radiation was proposed in this work. An experimental study of the correlation between self attenuation correction factor and sample thickness and its practical application was also introduced. The work was performed on NORM and uranyl nitrate bulk sample. The results of proposed methods agreed with those of traditional ones.(author)

  17. A maximum-likelihood reconstruction algorithm for tomographic gamma-ray nondestructive assay

    International Nuclear Information System (INIS)

    Prettyman, T.H.; Estep, R.J.; Cole, R.A.; Sheppard, G.A.

    1994-01-01

    A new tomographic reconstruction algorithm for nondestructive assay with high resolution gamma-ray spectroscopy (HRGS) is presented. The reconstruction problem is formulated using a maximum-likelihood approach in which the statistical structure of both the gross and continuum measurements used to determine the full-energy response in HRGS is precisely modeled. An accelerated expectation-maximization algorithm is used to determine the optimal solution. The algorithm is applied to safeguards and environmental assays of large samples (for example, 55-gal. drums) in which high continuum levels caused by Compton scattering are routinely encountered. Details of the implementation of the algorithm and a comparative study of the algorithm's performance are presented

  18. Advanced Laser-Compton Gamma-Ray Sources for Nuclear Materials Detection, Assay and Imaging

    Science.gov (United States)

    Barty, C. P. J.

    2015-10-01

    Highly-collimated, polarized, mono-energetic beams of tunable gamma-rays may be created via the optimized Compton scattering of pulsed lasers off of ultra-bright, relativistic electron beams. Above 2 MeV, the peak brilliance of such sources can exceed that of the world's largest synchrotrons by more than 15 orders of magnitude and can enable for the first time the efficient pursuit of nuclear science and applications with photon beams, i.e. Nuclear Photonics. Potential applications are numerous and include isotope-specific nuclear materials management, element-specific medical radiography and radiology, non-destructive, isotope-specific, material assay and imaging, precision spectroscopy of nuclear resonances and photon-induced fission. This review covers activities at the Lawrence Livermore National Laboratory related to the design and optimization of mono-energetic, laser-Compton gamma-ray systems and introduces isotope-specific nuclear materials detection and assay applications enabled by them.

  19. Gamma ray NDA assay system for total plutonium and isotopics in plutonium product solutions

    International Nuclear Information System (INIS)

    Cowder, L.R.; Hsue, S.T.; Johnson, S.S.; Parker, J.L.; Russo, P.A.; Sprinkle, J.K.; Asakura, Y.; Fukuda, T.; Kondo, I.

    1979-01-01

    A LASL-designed gamma-ray NDA instrument for assay of total plutonium and isotopics of product solutions at Tokai-Mura is currently installed and operating. The instrument is, optimally, a densitometer that uses radioisotopic sources for total plutonium measurements at the K absorption edge. The measured transmissions of additional gamma-ray lines from the same radioisotopic sources are used to correct for self-attenuation of passive gamma rays from plutonium. The corrected passive data give the plutonium isotopic content of freshly separated to moderately aged solutions. This off-line instrument is fully automated under computer control, with the exception of sample positioning, and operates routinely in a mode designed for measurement control. A one-half percent precision in total plutonium concentration is achieved with a 15-minute measurement

  20. Analysis of chromium-51 release assay data using personal computer spreadsheet software

    International Nuclear Information System (INIS)

    Lefor, A.T.; Steinberg, S.M.; Wiebke, E.A.

    1988-01-01

    The Chromium-51 release assay is a widely used technique to assess the lysis of labeled target cells in vitro. We have developed a simple technique to analyze data from Chromium-51 release assays using the widely available LOTUS 1-2-3 spreadsheet software. This package calculates percentage specific cytotoxicity and lytic units by linear regression. It uses all data points to compute the linear regression and can determine if there is a statistically significant difference between two lysis curves. The system is simple to use and easily modified, since its implementation requires neither knowledge of computer programming nor custom designed software. This package can help save considerable time when analyzing data from Chromium-51 release assays

  1. Martian Superoxide and Peroxide O2 Release (OR) Assay: A New Technology for Terrestrial and Planetary Applications

    Science.gov (United States)

    Georgiou, Christos D.; Zisimopoulos, Dimitrios; Panagiotidis, Konstantinos; Grintzalis, Kontantinos; Papapostolou, Ioannis; Quinn, Richard C.; McKay, Christopher P.; Sun, Henry J.

    2015-01-01

    This study presents an assay for the detection and quantification of soil metal superoxides and peroxides in regolith and soil. The O2 release (OR) assay is based on the enzymatic conversion of the hydrolysis products of metal oxides to O2, and their quantification by an O2 electrode based on the stoichiometry of the involved reactions: The intermediate product O2 from the hydrolysis of metal superoxides is converted by cytochrome c to O2, and also by superoxide dismutase (SOD) to 1/2 mol O2 and 1/2 mol H2O2, which is then converted by catalase (CAT) to 1/2 mol O2. The product H2O2 from the hydrolysis of metal peroxides and hydroperoxides is converted to 1/2 mol O2 by CAT. The assay-method was validated in a sealed sample chamber using a liquid-phase Clark-type O2 electrode with known concentrations of O2 and H2O2, and with commercial metal superoxide and peroxide mixed with Mars analogue Mojave and Atacama Desert soils. Carbonates and perchlorates, both present on Mars, do not interfere with the assay. The assay lower limit of detection, using luminescence quenching/optical sensing O2-electrodes, is 1 nmol O2 cm(exp. -3) or better. The activity of the assay enzymes SOD and cytochrome c was unaffected up to 6 Gy exposure by gamma-radiation, while CAT retained 100% and 40% of its activity at 3 and 6 Gy, respectively, demonstrating the suitability of these enzymes for planetary missions, e.g., in Mars or Europa.

  2. Evaluation of a gamma-spectroscopy gauge for uranium-plutonium assay

    International Nuclear Information System (INIS)

    Notea, A.; Segal, Y.

    1976-01-01

    A procedure is presented for the characterization of a gamma passive method for non-destructive analysis of nuclear fuel. The approachh provides an organized and systematic way for optimizing the assay system. The key function is the relative resolving power defined as the smallest relative change in the quantity of radionuclide measured that may be detected within a certain confidence level. This function is derived for nuclear fuel employing a model based on empirical parameters. The ability to detect changes in fuels of binary and trinary compositions with a 50-cm 3 Ge(Li) at a 1-min counting period is discussed. As an example to a binary composition, an enriched uranium fuel was considered. The 185-keV and 1001-keV gamma lines are used for the assay of 235 U and 238 U, respectively. As a trinary composition a plutonium-containing fuel was examined. The plutonium was identified by the 414-keV gamma line. The interference of the high-energy lines is carefully analysed, and numerical results are presented. For both cases the range of measurement under specific accuracy demands is determined. The approac described is suitable also for evaluation of other passive as well as active assay methods. (author)

  3. In vitro assay for ACTH-releasing activity using ACTH radioimmunoassay. ACTH releasing activities by various drugs

    Energy Technology Data Exchange (ETDEWEB)

    Hashimoto, K; Takahara, J; Hosogi, H; Ofuji, N; Yasuhara, T [Okayama Univ. (Japan). School of Medicine

    1976-02-01

    This report deals with an in vitro assay of ACTH releasing activity utilizing pituitary incubation combined with ACTH radioimmunoassay. Half of a rat pituitary was preincubated in 2ml Krebs Ringer bicarbonate buffer containing 0.2% glucose and 0.25% BSA (KRBG-BSA) for 1.5 hr (45 min x 2). The medium was replaced by 1 ml KRBG-BSA and incubated for 30 min. Then the medium was again replaced by 1 ml KRBG-BSA or KRBG-BSA containing test materials and incubated for another 30 min. The amount of ACTH assayed by radioimmunoassay in the 2nd 30 min incubation was compared with that in the 1st 30 min incubation, and the result was expressed as a percentage. In the ACTH radioimmunoassay, anti-ACTH serum was diluted to 1:1,500-3,000. The /sup 125/I-..cap alpha../sup 1 -24/ACTH-antibody system was not affected by lysine-vasopressin (LVP), arginine-vasopressin (AVP), rat's pituitary LH, GH or prolactin. Human /sup 1 -39/ACTH was used as the ACTH standard. The dilution curve of the incubation medium was parallel to the standard curve. Reproducibility of immunoassayable ACTH within-assay was 174 +- 5.0 pg/tube (CV=2.9%). A log dose-relationship was observed between the amounts of stalk median eminence extracts (SME; NIAMDD) added to the incubation medium and its ACTH releasing activities. The sensitivity of this assay method was at least 0.1 SME or 10 mU of LVP and AVP. Using this method, it was found that LVP, AVP, norepinephrine (100 ng/ml--200 ng/ml) and 5-hydroxytryptophane (1 ..mu..g/ml) had ACTH releasing activities, but LH-RH, TRH, glucagon, dopamine, phentolamine, propranolol, haloperidol, prostaglandin E/sub 1/ and indomethacin did not affect the release of ACTH.

  4. Thermostability of IFN-γ and IP-10 release assays for latent infection with Mycobacterium tuberculosis

    DEFF Research Database (Denmark)

    Blauenfeldt, Thomas; Wagner, Dirk; Aabye, Martine Grosos

    2016-01-01

    accuracy of IP-10 release assay and IGRAs. RESULTS: We included 65 patients with confirmed pulmonary tuberculosis and 160 healthy controls from 6 European centres collaborating in the TBnet. In patients, IP-10 responses increased 1.07 (IQR 0.90-1.36) fold and IFN-γ responses decreased 0.88 (IQR 0......INTRODUCTION: Interferon-γ (IFN-γ) inducible protein 10kD (IP-10) and IFN-γ release assays (IGRAs) are immunodiagnostic tests aiming to identify the presence of specific cellular immune responses, interpreted as markers for latent infection with Mycobacterium tuberculosis. Incubation at higher...

  5. A technique for combining neutron and gamma-ray data into a single assay value

    International Nuclear Information System (INIS)

    Pickrell, M.M.; Mercer, D.; Sharpe, T.J.

    1998-01-01

    The authors explored the potentials of using both neutron and gamma-ray measurements on a single item and combining these data into a single assay value. The purpose was to improve assay capability for sample matrices that are difficult to measure. They chose an empirical approach because they wanted to address difficult-to-measure items for which the assay problem is complex. They used the tomographic gamma scanner; a passive, high-efficiency neutron counter with add-a-source and multiplicity; and an active neutron, californium shuffler to obtain measurements. Twenty-four 200-L drums were measured with various matrices using all three machines. The matrices were chosen specifically to spain the difficult-to-measure assay problems for some or all of the instruments. For example, the authors measured a drum filled with concrete and another filled with metal. The data from these measurements were analyzed using the alternating conditional expectation algorithm, which is one of a class of generalized additive models. Other data fusion algorithms are also possible and are being explored. The intent was to find ways to combine the data that would reduce the matrix-induced measurement error

  6. Enhanced release of bone morphogenetic proteins from demineralized bone matrix by gamma irradiation

    International Nuclear Information System (INIS)

    Sung, Nak-Yun; Choi, Jong-il

    2015-01-01

    Gamma irradiation is a useful method for sterilizing demineralized bone matrix (DBM), but its effect on the osteoinductivity of DBM is still controversial. In this study, the osteoinductive activity of gamma-irradiated DBM was examined using a mouse myoblastic cell line (C2C12). DBM was extracted from adult bovine bone and was irradiated at a dose of 25 kGy using a 60 cobalt gamma-irradiator. Cell proliferation with DBM was not affected by gamma-irradiation, but alkaline phosphatase and osteocalcin productions were significantly increased in C2C12 cell groups treated with gamma-irradiated DBM. It was reasoned that bone morphogenetic proteins were more efficiently released from gamma-irradiated DBM than from the non-irradiated control. This result suggests the effectiveness of radiation sterilization of bone implants - Highlights: • Demineralized bone matrix (DBM) was gamma-irradiated for sterilization. • Irradiated DBM had higher alkaline phosphatase and osteocalcin production. • It was reasoned the more released bone morphogenetic proteins by irradiation. • This result supports the application of radiation sterilization for bone implants

  7. Verification by the FISH translocation assay of historic doses to Mayak workers from external gamma radiation

    Energy Technology Data Exchange (ETDEWEB)

    Sotnik, Natalia V.; Azizova, Tamara V. [Southern Urals Biophysics Institute (SUBI), Ozyorsk, Chelyabinsk Region (Russian Federation); Darroudi, Firouz [Leiden University Medical Center, Department of Toxicogenetics, Leiden (Netherlands); College of North Atlantic, Department of Health Science, Centre for Human Safety and Environmental Research, Doha (Qatar); Ainsbury, Elizabeth A.; Moquet, Jayne E.; Lloyd, David C.; Hone, Pat A.; Edwards, Alan A. [Public Health England, Chilton, Oxfordshire (United Kingdom); Fomina, Janna [Leiden University Medical Center, Department of Toxicogenetics, Leiden (Netherlands)

    2015-11-15

    The aim of this study was to apply the fluorescence in situ hybridization (FISH) translocation assay in combination with chromosome painting of peripheral blood lymphocytes for retrospective biological dosimetry of Mayak nuclear power plant workers exposed chronically to external gamma radiation. These data were compared with physical dose estimates based on monitoring with badge dosimeters throughout each person's working life. Chromosome translocation yields for 94 workers of the Mayak production association were measured in three laboratories: Southern Urals Biophysics Institute, Leiden University Medical Center and the former Health Protection Agency of the UK (hereinafter Public Health England). The results of the study demonstrated that the FISH-based translocation assay in workers with prolonged (chronic) occupational gamma-ray exposure was a reliable biological dosimeter even many years after radiation exposure. Cytogenetic estimates of red bone marrow doses from external gamma rays were reasonably consistent with dose measurements based on film badge readings successfully validated in dosimetry system ''Doses-2005'' by FISH, within the bounds of the associated uncertainties. (orig.)

  8. Relative mass resolution technique for optimum design of a gamma nondestructive assay system

    International Nuclear Information System (INIS)

    Koh, Duck Joon

    1995-02-01

    Nondestructive assay(NDA) is a widely used nuclear technology for quantitative elemental and isotopic assay. Nondestructive assay is performed by the detection of an identifying radiation emerging from the sample, which can be unambiguously related to the element or isotope of interest. In every assay we can identify two distinct factors that lead to measurement uncertainty. We refer to these as statistical and spatial uncertainties. If the spatial distribution of the analyte and the matrix material in the sample are known and fairly constant from sample to sample, then the major source of measurement uncertainty is the statistical uncertainty resulting from randomness in the counting process. The spatial uncertainty is independent of the measurement time and therefore sets a lower limit to the measurement uncertainty, which is inherent in the assay system in conjunction with the population of samples to be measured. The only way to minimize the spatial uncertainty is an optimized design of the assay system. Therefore we have to decide on the type and number of detectors to be used, their deployment around the sample, the type of radiation to be measured, the duration of each measurement, the size and shape of the sample drum. The design procedure leading to the optimal assay system should be based on a quantitative(RMR:Relative Mass Resolution) comparison of the performance of each proposed design. For NDA system design of low level radwaste, a specific purpose Monte Carlo code has been developed to simulate point-source responses for sources within an assayed radwaste drum and to analyze the effect of scattered gammas from higher energy gammas on the spectrum of a low energy gamma-ray. We could use the well-known Monte Carlo code, such as MCNP for the simulation of NDA in the case of low level radwaste. But, MCNP is a multi-purpose Monte Carlo transport code for several geometries which requires large memory and long CPU time. For some cases in nuclear

  9. Wholesomeness studies on gamma-irradiated smoked fish using short-term mutagenicity assays

    International Nuclear Information System (INIS)

    De la Rosa, A.M.; Banzon, R.B.

    1985-12-01

    The effect of gamma irradiation on the mutagenicity potential of wood-smoked mackerel (Rastrelliger sp.) was investigated. Smoked fish were irradiated with dose of 2.0, 4.0, 6.0 and 8.0 KGy, and tested for mutagenic activity using the Salmonella plate incorporation assay, host-mediated assay, and micronucleus test. The DMSO extract of unirradiated smoked fish was found to be mutagenic, without metabolic activation in Salmonella strains TA 100 and TA 104, both sensitive to base-pair substitution mutations. Strains TA 98 and TA 97 which are sensitive to frameshift mutations showed no mutagenic activity towards the same DMSO extract. The observed response towards the Salmonella strains was not affected by irradiation in the range of radiation doses studied. The presence of protamutagens in the DMSO extract of unirradiated smoked fish was not detected using the host-mediated assay. In another in-vivo test however, the same DMSO extract induced the formation of micronuclei in the bonemarrow cells of mice. Gamma irradiation up to a dose of 8.0 KGy did not affect the observed mutagenicity of wood-smoked fish. (author)

  10. Delayed Gamma-Ray Spectroscopy for Non-Destructive Assay of Nuclear Materials

    Energy Technology Data Exchange (ETDEWEB)

    Ludewigt, Bernhard [Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States); Mozin, Vladimir [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States); Campbell, Luke [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Favalli, Andrea [Los Alamos National Lab. (LANL), Los Alamos, NM (United States); Hunt, Alan W. [Idaho State Univ., Pocatello, ID (United States); Reedy, Edward T. [Idaho State Univ., Pocatello, ID (United States); Seipel, Heather A. [Idaho State Univ., Pocatello, ID (United States)

    2015-06-01

    Modeling capabilities were added to an existing framework and codes were adapted as needed for analyzing experiments and assessing application-specific assay concepts including simulation of measurements over many short irradiation/spectroscopy cycles. The code package was benchmarked against the data collected at the IAC for small targets and assembly-scale data collected at LANL. A study of delayed gamma-ray spectroscopy for nuclear safeguards was performed for a variety of assemblies in the extensive NGSI spent fuel library. The modeling results indicate that delayed gamma-ray responses can be collected from spent fuel assemblies with statistical quality sufficient for analyzing their isotopic composition using a 1011 n/s neutron generator and COTS detector instrumentation.

  11. Assessment of gamma ray-induced DNA damage in Lasioderma serricorne using the comet assay

    International Nuclear Information System (INIS)

    Kameya, Hiromi; Miyanoshita, Akihiro; Imamura, Taro; Todoriki, Setsuko

    2012-01-01

    We attempted a DNA comet assay under alkaline conditions to verify the irradiation treatment of pests. Lasioderma serricorne (Fabricius) were chosen as test insects and irradiated with gamma rays from a 60 Co source at 1 kGy. We conducted the comet assay immediately after irradiation and over time for 7 day. Severe DNA fragmentation in L. serricorne cells was observed just after irradiation and the damage was repaired during the post-irradiation period in a time-dependent manner. The parameters of the comet image analysis were calculated, and the degree of DNA damage and repair were evaluated. Values for the Ratio (a percentage determined by fluorescence in the damaged area to overall luminance, including intact DNA and the damaged area of a comet image) of individual cells showed that no cells in the irradiated group were included in the Ratio<0.1 category, the lowest grade. This finding was observed consistently throughout the 7-day post-irradiation period. We suggest that the Ratio values of individual cells can be used as an index of irradiation history and conclude that the DNA comet assay under alkaline conditions, combined with comet image analysis, can be used to identify irradiation history. - Highlights: ► We investigated the DNA comet assay to verify the irradiation of pests. ► Ratio and Tail Moment were higher in irradiated groups than in the control group. ► The DNA comet assay can be used to identify irradiation history.

  12. Delayed Gamma-Ray Spectroscopy for Non-Destructive Assay of Nuclear Materials

    International Nuclear Information System (INIS)

    Ludewigt, Bernhard; Mozin, Vladimir; Campbell, Luke; Favalli, Andrea; Hunt, Alan W.; Reedy, Edward T.E.; Seipel, Heather

    2015-01-01

    High-energy, beta-delayed gamma-ray spectroscopy is a potential, non-destructive assay techniques for the independent verification of declared quantities of special nuclear materials at key stages of the fuel cycle and for directly assaying nuclear material inventories for spent fuel handling, interim storage, reprocessing facilities, repository sites, and final disposal. Other potential applications include determination of MOX fuel composition, characterization of nuclear waste packages, and challenges in homeland security and arms control verification. Experimental measurements were performed to evaluate fission fragment yields, to test methods for determining isotopic fractions, and to benchmark the modeling code package. Experimental measurement campaigns were carried out at the IAC using a photo-neutron source and at OSU using a thermal neutron beam from the TRIGA reactor to characterize the emission of high-energy delayed gamma rays from 235 U, 239 Pu, and 241 Pu targets following neutron induced fission. Data were collected for pure and combined targets for several irradiation/spectroscopy cycle times ranging from 10/10 seconds to 15/30 minutes.The delayed gamma-ray signature of 241 Pu, a significant fissile constituent in spent fuel, was measured and compared to 239 Pu. The 241 Pu/ 239 Pu ratios varied between 0.5 and 1.2 for ten prominent lines in the 2700-3600 keV energy range. Such significant differences in relative peak intensities make it possible to determine relative fractions of these isotopes in a mixed sample. A method for determining fission product yields by fitting the energy and time dependence of the delayed gamma-ray emission was developed and demonstrated on a limited 235 U data set. De-convolution methods for determining fissile fractions were developed and tested on the experimental data. The use of high count-rate LaBr 3 detectors was investigated as a potential alternative to HPGe detectors. Modeling capabilities were added to an

  13. Delayed Gamma-Ray Spectroscopy for Non-Destructive Assay of Nuclear Materials

    Energy Technology Data Exchange (ETDEWEB)

    Ludewigt, Bernhard [Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States); Mozin, Vladimir [Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States); Campbell, Luke [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Favalli, Andrea [Los Alamos National Lab. (LANL), Los Alamos, NM (United States); Hunt, Alan W. [Idaho National Lab. (INL), Idaho Falls, ID (United States); Reedy, Edward T.E. [Idaho National Lab. (INL), Idaho Falls, ID (United States); Seipel, Heather [Idaho National Lab. (INL), Idaho Falls, ID (United States)

    2015-06-01

    High-­energy, beta-delayed gamma-­ray spectroscopy is a potential, non-­destructive assay techniques for the independent verification of declared quantities of special nuclear materials at key stages of the fuel cycle and for directly assaying nuclear material inventories for spent fuel handling, interim storage, reprocessing facilities, repository sites, and final disposal. Other potential applications include determination of MOX fuel composition, characterization of nuclear waste packages, and challenges in homeland security and arms control verification. Experimental measurements were performed to evaluate fission fragment yields, to test methods for determining isotopic fractions, and to benchmark the modeling code package. Experimental measurement campaigns were carried out at the IAC using a photo-­neutron source and at OSU using a thermal neutron beam from the TRIGA reactor to characterize the emission of high-­energy delayed gamma rays from 235U, 239Pu, and 241Pu targets following neutron induced fission. Data were collected for pure and combined targets for several irradiation/spectroscopy cycle times ranging from 10/10 seconds to 15/30 minutes.The delayed gamma-ray signature of 241Pu, a significant fissile constituent in spent fuel, was measured and compared to 239Pu. The 241Pu/239Pu ratios varied between 0.5 and 1.2 for ten prominent lines in the 2700-­3600 keV energy range. Such significant differences in relative peak intensities make it possible to determine relative fractions of these isotopes in a mixed sample. A method for determining fission product yields by fitting the energy and time dependence of the delayed gamma-­ray emission was developed and demonstrated on a limited 235U data set. De-­convolution methods for determining fissile fractions were developed and tested on the experimental data. The use of high count-­rate LaBr3 detectors

  14. Reproducibility of (n,γ) gamma ray spectrum in Pb under different ENDF/B releases

    Energy Technology Data Exchange (ETDEWEB)

    Kebwaro, J.M., E-mail: jeremiahkebwaro@gmail.com [Department of Physical Sciences, Karatina University, P.O. Box 1957-10101, Karatina (Kenya); He, C.H.; Zhao, Y.L. [School of Nuclear Science and Technology, Xian Jiaotong University, Xian, Shaanxi 710049 (China)

    2016-04-15

    Radiative capture reactions are of interest in shielding design and other fundamental research. In this study the reproducibility of (n,γ) reactions in Pb when cross-section data from different ENDF/B releases are used in the Monte-Carlo code, MCNP, was investigated. Pb was selected for this study because it is widely used in shielding applications where capture reactions are likely to occur. Four different neutron spectra were declared as source in the MCNP model which consisted of a simple spherical geometry. The gamma ray spectra due to the capture reactions were recorded at 10 cm from the center of the sphere. The results reveal that the gamma ray spectrum produced by ENDF/B-V is in reasonable agreement with that produced when ENDF/B-VI.6 is used. However the spectrum produced by ENDF/B-VII does not reveal any primary gamma rays in the higher energy region (E > 3 MeV). It is further observed that the intensities of the capture gamma rays produced when various releases are used differ by a some margin showing that the results are not reproducible. The generated spectra also vary with the spectrum of the source neutrons. The discrepancies observed among various ENDF/B releases could raise concerns to end users and need to be addressed properly during benchmarking calculations before the next release. The evaluation from ENDF to ACE format that is supplied with MCNP should also be examined because errors might have arisen during the evaluation.

  15. A radiolabel-release microwell assay for proteolytic enzymes present in cell culture media

    International Nuclear Information System (INIS)

    Rucklidge, G.J.; Milne, G.

    1990-01-01

    A modified method for the measurement of proteolytic enzyme activity in cell culture-conditioned media has been developed. Using the release of 3H-labeled peptides from 3H-labeled gelatin the method is performed in microwell plates. The substrate is insolubilized and attached to the wells by glutaraldehyde treatment, thus eliminating the need for a precipitation step at the end of the assay. The assay is sensitive, reproducible, and convenient for small sample volumes. The effect of different protease inhibitors on activity can be assessed rapidly allowing an early characterization of the enzyme. It can also be adapted to microplate spectrophotometric analysis by staining residual substrate with Coomassie blue

  16. Evaluation of an automated assay system to measure soil radionuclides by L x-ray and gamma-ray spectrometry

    International Nuclear Information System (INIS)

    Nyhan, J.W.; Drennon, B.J.; Crowell, J.M.

    1982-08-01

    An automated radionuclide assay system for conducting soil radioassays using L x-ray and gamma-ray spectrometry was evaluated. Wet chemistry assay procedures were shown to be considerably more time consuming than similar analyses of soil on this radionuclide assay system. The detection limits of 241 Am and plutonium were determined, as well as the reproducibility of radionuclide assay results. The L x-ray spectrometric measurements were compared with radiochemical analyses on several tuff samples. The assay system's intrinsic germanium detector was found to respond linearly to varying low concentrations of 241 Am and plutonium, both of which were easily detected in the presence of elevated concentrations of 137 Cs

  17. Estimated Uncertainty in Segmented Gamma Scanner Assay Results due to the Variation in Drum Tare Weights

    International Nuclear Information System (INIS)

    Bosko, A.; Croft, St.; Gulbransen, E.

    2009-01-01

    General purpose gamma scanners are often used to assay unknown drums that differ from those used to create the default calibration. This introduces a potential source of bias into the matrix correction when the correction is based on the estimation of the mean density of the drum contents from a weigh scale measurement. In this paper we evaluate the magnitude of this bias that may be introduced by performing assay measurements with a system whose matrix correction algorithm was calibrated with a set of standard drums but applied to a population of drums whose tare weight may be different. The matrix correction factors are perturbed in such cases because the unknown difference in tare weight gets reflected as a bias in the derived matrix density. This would be the only impact if the difference in tare weight was due solely to the weight of the lid or base, say. But in reality the reason for the difference may be because the steel wall of the drum is of a different thickness. Thus, there is an opposing interplay at work which tends to compensate. The purpose of this work is to evaluate and bound the magnitude of the resulting assay uncertainty introduced by tare weight variation. We compare the results obtained using simple analytical models and the 3-D ray tracing with ISOCS software to illustrate and quantify the problem. The numerical results allow a contribution to the Total Measurement Uncertainty (TMU) to be propagated into the final assay result. (authors)

  18. Gamma ray scanner systems for nondestructive assay of heterogeneous waste barrels

    International Nuclear Information System (INIS)

    Martz, H.E.; Decman, B.J.; Roberson, G.P.; Levai, F.

    1997-01-01

    Traditional gamma safeguards measurements have usually been performed using a segmented gamma scanning (SGS) system. The accuracy of this technique relies on the assumption that the sample matrix and the activity are both uniform for a segment. Waste barrels are often highly heterogeneous, span a wide range of composition and matrix type. The primary sources of error are all directly or indirectly related to a non-uniform measurement response associated with unknown radioactive source spatial distribution and heterogeneity of the matrix. These errors can be significantly reduced by some imaging techniques that measure exact spatial locations of sources and attenuation maps. In this paper we describe a joint R ampersand D effort between the Lawrence Livermore National Laboratory (LLNL) and the Institute of Nuclear Techniques (INT) of the Technical University, Budapest, to compare results obtained by two different gamma-ray nondestructive assay (NDA) systems used for imaging waste barrels. The basic principles are the same, but the approaches are different. Key factors to judge the adequacy of a method are the detection limit and the accuracy. Test drums representing waste to be measured are used to determine basic parameters of these techniques

  19. A weighted least-squares lump correction algorithm for transmission-corrected gamma-ray nondestructive assay

    International Nuclear Information System (INIS)

    Prettyman, T.H.; Sprinkle, J.K. Jr.; Sheppard, G.A.

    1993-01-01

    With transmission-corrected gamma-ray nondestructive assay instruments such as the Segmented Gamma Scanner (SGS) and the Tomographic Gamma Scanner (TGS) that is currently under development at Los Alamos National Laboratory, the amount of gamma-ray emitting material can be underestimated for samples in which the emitting material consists of particles or lumps of highly attenuating material. This problem is encountered in the assay of uranium and plutonium-bearing samples. To correct for this source of bias, we have developed a least-squares algorithm that uses transmission-corrected assay results for several emitted energies and a weighting function to account for statistical uncertainties in the assay results. The variation of effective lump size in the fitted model is parameterized; this allows the correction to be performed for a wide range of lump-size distributions. It may be possible to use the reduced chi-squared value obtained in the fit to identify samples in which assay assumptions have been violated. We found that the algorithm significantly reduced bias in simulated assays and improved SGS assay results for plutonium-bearing samples. Further testing will be conducted with the TGS, which is expected to be less susceptible than the SGS to systematic source of bias

  20. Whole blood interferon-gamma assay for baseline tuberculosis screening among Japanese healthcare students.

    Directory of Open Access Journals (Sweden)

    Katsuyuki Hotta

    Full Text Available BACKGROUND: The whole blood interferon-gamma assay (QuantiFERON-TB-2G; QFT has not been fully evaluated as a baseline tuberculosis screening test in Japanese healthcare students commencing clinical contact. The aim of this study was to compare the results from the QFT with those from the tuberculin skin test (TST in a population deemed to be at a low risk for infection with Mycobacterium tuberculosis. METHODOLOGY/PRINCIPAL FINDINGS: Healthcare students recruited at Okayama University received both the TST and the QFT to assess the level of agreement between these two tests. The interleukin-10 levels before and after exposure to M tuberculosis-specific antigens (early-secreted antigenic target 6-kDa protein [ESAT-6] and culture filtrate protein 10 [CFP-10] were also measured. Of the 536 healthcare students, most of whom had been vaccinated with bacillus-Calmette-Guérin (BCG, 207 (56% were enrolled in this study. The agreement between the QFT and the TST results was poor, with positive result rates of 1.4% vs. 27.5%, respectively. A multivariate analysis also revealed that the induration diameter of the TST was not affected by the interferon-gamma concentration after exposure to either of the antigens but was influenced by the number of BCG needle scars (p = 0.046. The whole blood interleukin-10 assay revealed that after antigen exposure, the median increases in interleukin-10 concentration was higher in the subgroup with the small increase in interferon-gamma concentration than in the subgroup with the large increase in interferon-gamma concentration (0.3 vs. 0 pg/mL; p = 0.004. CONCLUSIONS/SIGNIFICANCE: As a baseline screening test for low-risk Japanese healthcare students at their course entry, QFT yielded quite discordant results, compared with the TST, probably because of the low specificity of the TST results in the BCG-vaccinated population. We also found, for the first time, that the change in the interleukin-10 level after exposure to

  1. Gamma-ray imaging and holdup assays of 235-F PuFF cells 1 & 2

    Energy Technology Data Exchange (ETDEWEB)

    Aucott, T. [Savannah River Site (SRS), Aiken, SC (United States). Savannah River National Lab. (SRNL)

    2017-12-20

    Savannah River National Laboratory (SRNL) Nuclear Measurements (L4120) was tasked with performing enhanced characterization of the holdup in the PuFF shielded cells. Assays were performed in accordance with L16.1-ADS-2460 using two high-resolution gamma-ray detectors. The first detector, an In Situ Object Counting System (ISOCS)-characterized detector, was used in conjunction with the ISOCS Geometry Composer software to quantify grams of holdup. The second detector, a Germanium Gamma-ray Imager (GeGI), was used to visualize the location and relative intensity of the holdup in the cells. Carts and collimators were specially designed to perform optimum assays of the cells. Thick, pencil-beam tungsten collimators were fabricated to allow for extremely precise targeting of items of interest inside the cells. Carts were designed with a wide range of motion to position and align the detectors. A total of 24 measurements were made, each typically 24 hours or longer to provide sufficient statistical precision. This report presents the results of the enhanced characterization for cells 1 and 2. The measured gram values agree very well with results from the 2014 study. In addition, images were created using both the 2014 data and the new GeGI data. The GeGI images of the cells walls reveal significant Pu-238 holdup on the surface of the walls in cells 1 and 2. Additionally, holdup is visible in the two pass-throughs from cell 1 to the wing cabinets. This report documents the final element (exterior measurements coupled with gamma-ray imaging and modeling) of the enhanced characterization of cells 1-5 (East Cell Line).

  2. A simple fluorescence based assay for quantification of human immunodeficiency virus particle release

    Directory of Open Access Journals (Sweden)

    Heuser Anke-Mareil

    2010-04-01

    Full Text Available Abstract Background The assembly and release of human immunodeficiency virus (HIV particles from infected cells represent attractive, but not yet exploited targets for antiretroviral therapy. The availability of simple methods to measure the efficiency of these replication steps in tissue culture would facilitate the identification of host factors essential for these processes as well as the screening for lead compounds acting as specific inhibitors of particle formation. We describe here the development of a rapid cell based assay for quantification of human immunodeficiency virus type 1 (HIV-1 particle assembly and/or release. Results Using a fluorescently labelled HIV-derivative, which carries an eYFP domain within the main viral structural protein Gag in the complete viral protein context, the release of virus like particles could be monitored by directly measuring the fluorescence intensity of the tissue culture supernatant. Intracellular Gag was quantitated in parallel by direct fluorescence analysis of cell lysates, allowing us to normalize for Gag expression efficiency. The assay was validated by comparison with p24 capsid ELISA measurements, a standard method for quantifying HIV-1 particles. Optimization of conditions allowed the robust detection of particle amounts corresponding to 50 ng p24/ml in medium by fluorescence spectroscopy. Further adaptation to a multi-well format rendered the assay suitable for medium or high throughput screening of siRNA libraries to identify host cell factors involved in late stages of HIV replication, as well as for random screening approaches to search for potential inhibitors of HIV-1 assembly or release. Conclusions The fast and simple fluorescence based quantification of HIV particle release yielded reproducible results which were comparable to the well established ELISA measurements, while in addition allowing the parallel determination of intracellular Gag expression. The protocols described here

  3. Quality Control Assays for Clinical-Grade Human Mesenchymal Stromal Cells: Methods for ATMP Release.

    Science.gov (United States)

    Radrizzani, Marina; Soncin, Sabrina; Lo Cicero, Viviana; Andriolo, Gabriella; Bolis, Sara; Turchetto, Lucia

    2016-01-01

    Mesenchymal stromal/stem cells (MSC) are promising candidates for the development of cell-based therapies for various diseases and are currently being evaluated in a number of clinical trials (Sharma et al., Transfusion 54:1418-1437, 2014; Ikebe and Suzuki, Biomed Res Int 2014:951512, 2014). MSC for therapeutic applications are classified as advanced therapy medicinal products (ATMP) (Regulation (EC) No 1394/2007 of the European Parliament and of the Council of 13 November 2007 on advanced therapy medicinal products and amending Directive 2001/83/EC and Regulation (EC) No 726/2004) and must be prepared according to good manufacturing practices ( http://ec.europa.eu/health/documents/eudralex/vol-4 ). They may be derived from different starting materials (mainly bone marrow (BM), adipose tissue, or cord blood) and applied as fresh or cryopreserved products, in the autologous as well as an allogeneic context (Sharma et al., Transfusion 54:1418-1437, 2014; Ikebe and Suzuki, Biomed Res Int 2014:951512, 2014; Sensebé and Bourin, Transplantation 87(9 Suppl):S49-S53, 2009). In any case, they require an approved and well-defined panel of assays in order to be released for clinical use.This chapter describes analytical methods implemented and performed in our cell factory as part of the release strategy for an ATMP consisting of frozen autologous BM-derived MSC. Such methods are designed to assess the safety (sterility, endotoxin, and mycoplasma assays) and identity/potency (cell count and viability, immunophenotype and clonogenic assay) of the final product. Some assays are also applied to the biological starting material (sterility) or carried out as in-process controls (sterility, cell count and viability, immunophenotype, clonogenic assay).The validation strategy for each analytical method is described in the accompanying Chapter 20 .

  4. Analysis and databasing software for integrated tomographic gamma scanner (TGS) and passive-active neutron (PAN) assay systems

    International Nuclear Information System (INIS)

    Estep, R.J.; Melton, S.G.; Buenafe, C.

    2000-01-01

    The CTEN-FIT program, written for Windows 9x/NT in C++,performs databasing and analysis of combined thermal/epithermal neutron (CTEN) passive and active neutron assay data and integrates that with isotopics results and gamma-ray data from methods such as tomographic gamma scanning (TGS). The binary database is reflected in a companion Excel database that allows extensive customization via Visual Basic for Applications macros. Automated analysis options make the analysis of the data transparent to the assay system operator. Various record browsers and information displays simplify record keeping tasks

  5. Induction and assay of pure soyabean mutants obtained from gamma irradiation

    International Nuclear Information System (INIS)

    Nasseri Tafti, M.; Rezazadeh, M.; Yousefi, F.; Sabzi, H.

    2002-01-01

    Gamma ray is an electromagnetic type of radiation and produces ions when passing through biological matter. It can be applied in plant breeding to induce variation. The most important character of this ray is to produce changes in DNA structure existing in cell. Mutants induced by irradiation of soybean seeds were assayed for their agronomic traits. Two locations were used for this purpose, Alishtar and Karaj. There were significant differences between soybean mutant lines and their check cv. Williams at 1% level and cv.Clark at 5% level. Line No. 47 with 4782 kg/hect. Possessed the top of the list and next to it line No.38 with 4722 kg/hect. Some mutant lines reached maturity 10 to 12 days earlier than commercial cv s used as check cultivars

  6. Radioactive waste package assay facility. Volume 2. Investigation of active neutron and active gamma interrogation

    International Nuclear Information System (INIS)

    Bailey, M.; Bunce, L.J.; Findlay, D.J.S.; Jolly, J.E.; Parsons, T.V.; Sene, M.R.; Swinhoe, M.T.

    1992-01-01

    Volume 2 of this report describes the theoretical and experimental work carried out at Harwell on active neutron and active gamma interrogation of 500 litre cemented intermediate level waste drums. The design of a suitable neutron generating target in conjunction with a LINAC was established. Following theoretical predictions of likely neutron responses, an experimental assay assembly was built. Responses were measured for simulated drums of ILW, based on CAGR, Magnox and PCM wastes. Good correlations were established between quantities of 235 -U, nat -U and D 2 O contained in the drums, and the neutron signals. Expected sensitivities are -1g of fissile actinide and -100g of total actinide. A measure of spatial distribution is obtainable. The neutron time spectra obtained during neutron interrogation were more complex than expected, and more analysis is needed. Another area of discrepancy is the difference between predicted and measured thermal neutron flux in the drum. Clusters of small 3 He proportional counters were found to be much superior for fast neutron detection than larger diameter counters. It is necessary to ensure constancy of electron beam position relative to target(s) and drum, and prudent to measure the target neutron or gamma output as appropriate. 59 refs., 77 figs., 11 tabs

  7. Measurement of Nonribosomal Peptide Synthetase Adenylation Domain Activity Using a Continuous Hydroxylamine Release Assay.

    Science.gov (United States)

    Duckworth, Benjamin P; Wilson, Daniel J; Aldrich, Courtney C

    2016-01-01

    Adenylation is a crucial enzymatic process in the biosynthesis of nonribosomal peptide synthetase (NRPS) derived natural products. Adenylation domains are considered the gatekeepers of NRPSs since they select, activate, and load the carboxylic acid substrate onto a downstream peptidyl carrier protein (PCP) domain of the NRPS. We describe a coupled continuous kinetic assay for NRPS adenylation domains that substitutes the PCP domain with hydroxylamine as the acceptor molecule. The pyrophosphate released from the first-half reaction is then measured using a two-enzyme coupling system, which detects conversion of the chromogenic substrate 7-methylthioguanosine (MesG) to 7-methylthioguanine. From profiling substrate specificity of unknown or engineered adenylation domains to studying chemical inhibition of adenylating enzymes, this robust assay will be of widespread utility in the broad field NRPS enzymology.

  8. Calcein AM release-based cytotoxic cell assay for fish leucocytes.

    Science.gov (United States)

    Iwanowicz, Luke R; Densmore, Christine L; Ottinger, Christopher A

    2004-02-01

    A non-specific cytotoxic cell assay for fish is presented that is based on the release of the activated fluorochrome calcein AM from lysed carp epithelioma papulosum cyprini (EPC) cells. To establish the suitability of treating EPC cells with calcein AM the uptake and spontaneous release of the calcein AM by the EPC cells was evaluated. Incubation of 5 microM calcein AM in culture medium with 1x10(5)EPC cells well(-1)for a minimum of 3 h provided sufficient labelling. Spontaneous release of fluorescence from the labelled EPC cells during 10 h of post labelling incubation ranged from 30 to 39% of the total observed fluorescence. Cytotoxic activity of trout leucocytes was evaluated at three leucocyte to target cell ratios (10:1, 2:1 and 1:1) following incubation (4, 6, 8, and 10 h) with calcein AM-labelled EPC cells at 15 degrees C. In some instances, the monoclonal antibody specific for the NCC surface receptor NCCRP-1 (MAb5C.6) was included in the cultures. The activity of NCC cells was significantly inhibited in the presence of 0.25 microg well(-1)of MAb5C.6 relative to no antibody (Prelease assay.

  9. Capability for identification of gamma-irradiated bovine liver by new high sensitivity comet assay

    International Nuclear Information System (INIS)

    Miyahara, Makoto; Toyoda, Masatake; Saito, Akiko; Ito, Hitoshi

    2000-01-01

    DNA in food will sustain damage by gamma radiation. The detection capability of the high sensitivity comet assay was studied using fluorescence-microscopy. Beef liver was irradiated at a range of 1 Gy to 8 kGy. Single cells were obtained from the irradiated liver, then analyzed by agaros-gel electrophoresis. The pH of the buffer for electrophoresis was pH 13, which is generally utilized for sensitive detection of DNA damage. The pattern formed by DNA was visualized by staining with ethidium bromide. The resulting comets were evaluated with a scale we developed, and Influence Scores were calculated based on the Tice method. It is possible to detect irradiation damage to beef liver at 10 Gy. Together with Influence Score, histogram of comet type is used for detection of irradiation. We elucidated those histograms were useful for distinguishing damage caused by irradiation from that of others. DNA damage can be caused not only by irradiation, but also by the other treatments. Therefore, the respective influences of freezing, preservation, irradiating temperature, atmosphere of irradiation, cooking, and homogenizing devices were also examined. This new comet assay will be a useful method of detecting DNA damage to identify irradiated foods. (author)

  10. The gamma spectrometry a powerful tool for irradiated fuel and fission products release studies

    International Nuclear Information System (INIS)

    Pontillon, Y.; Roure, C.; Lacroix, B.; Martella, T.; Ducros, G.; Ravel, S.; Gleizes, B.

    2003-01-01

    Over the last decades, due to the potentially severe consequences of a nuclear incident and/or accident for surrounding populations as well as the environment, international safety authorities launched R and D programs in support of general policy on exploitation of nuclear energy. This increasing interest enabled starting of many research programs in CEA and particularly in Nuclear Energy Directorate (DEN). Most of them are devoted to (i) the source term of fission products (including gas) and actinides released from PWR fuel samples in normal or accident conditions, (ii) burn-up determination, (iii) isotopic repartition... by quantitative gamma spectrometry. In this context, the Department of Fuel Studies (DEC), part of the DEN, has acquired considerable experience in this field of research. In order to attain the required capabilities, specific technical facilities set up in shielded hot cells at the CEA-Grenoble and CEA-Cadarache have been developed. In particular, the researchers of the Department have developed several gamma scanning benches and a set of two thermal treatment devices, including the so-called 'VERCORS facility'. These devices are associated to on line quantitative gamma spectrometry, in order to measure emitted gas and fission products (FPs). The greatest asset of such installations is to ensure a high analytical experiments rate, and as a consequence to make parametrical approach of planned studies easier. The first part of the present communication focuses, on the one hand, on the peculiar aspects of the gamma spectrometry applied on irradiated fuel, mad on the other hand, on the technical aspect of the different facilities (i.e. quantitative gamma spectrometry apparatus and corresponding 'home made' software). The last part is devoted to the results which can be obtained with such installation. In particular, it will be explained how experimental programs on FPs and gas release in normal and/or accidental conditions can be conducted

  11. Evaluation of genotoxicity of the acute gamma radiation on earthworm Eisenia fetida using single cell gel electrophoresis technique (Comet assay).

    Science.gov (United States)

    Sowmithra, K; Shetty, N J; Jha, S K; Chaubey, R C

    2015-12-01

    Earthworms (Eisenia fetida) most suitable biological indicators of radioactive pollution. Radiation-induced lesions in DNA can be considered to be molecular markers for early effects of ionizing radiation. Gamma radiation produces a wide spectrum of DNA. Some of these lesions, i.e., DNA strand breaks and alkali labile sites can be detected by the single-cell gel electrophoresis (SCGE) or comet assay by measuring the migration of DNA from immobilized nuclear DNA. E. fetida were exposed to different doses of gamma radiation, i.e., 1, 5, 10, 20, 30, 40 and 50Gy, and comet assay was performed for all the doses along with control at 1, 3 and 5h post irradiation to evaluate the genotoxicity of gamma radiation in this organism. The DNA damage was measured as percentage of comet tail DNA. A significant increase in DNA damage was observed in samples exposed to 5Gy and above, and the increase in DNA damage was dose dependent i.e., DNA damage was increased with increased doses of radiation. The highest DNA damage was noticed at 1h post irradiation and gradually decreased with time, i.e., at 3 and 5h post irradiation. The present study reveals that gamma radiation induces DNA damage in E. fetida and the comet assay is a sensitive and rapid method for its detection to detect genotoxicity of gamma radiation. Copyright © 2015 Elsevier B.V. All rights reserved.

  12. RSAC, Gamma Doses, Inhalation and Ingestion Doses, Fission Products Inventory after Fission Products Release

    International Nuclear Information System (INIS)

    Richardson, L.C.

    1967-01-01

    1 - Description of problem or function: RSAC generates a fission product inventory from a given set of reactor operating conditions and then computes the external gamma dose, the deposition gamma dose, and the inhalation-ingestion dose to critical body organs as a result of exposure to these fission products. Program output includes reactor operating history, fission product inventory, dosages, and ingestion parameters. 2 - Method of solution: The fission product inventory generated by the reactor operating conditions and the inventory remaining at various times after release are computed using the equations of W. Rubinson in Journal of Chemical Physics, Vol. 17, pages 542-547, June 1949. The external gamma dose and the deposition gamma dose are calculated by determining disintegration rates as a function of space and time, then integrating using Hermite's numerical techniques for the spatial dependence. The inhalation-ingestion dose is determined by the type and quantity of activity inhaled and the biological rate of decay following inhalation. These quantities are integrated with respect to time to obtain the dosage. The ingestion dose is related to the inhalation dose by an input constant

  13. Automated assay for screening the enzymatic release of reducing sugars from micronized biomass

    Directory of Open Access Journals (Sweden)

    Asther Marcel

    2010-07-01

    Full Text Available Abstract Background To reduce the production cost of bioethanol obtained from fermentation of the sugars provided by degradation of lignocellulosic biomass (i.e., second generation bioethanol, it is necessary to screen for new enzymes endowed with more efficient biomass degrading properties. This demands the set-up of high-throughput screening methods. Several methods have been devised all using microplates in the industrial SBS format. Although this size reduction and standardization has greatly improved the screening process, the published methods comprise one or more manual steps that seriously decrease throughput. Therefore, we worked to devise a screening method devoid of any manual steps. Results We describe a fully automated assay for measuring the amount of reducing sugars released by biomass-degrading enzymes from wheat-straw and spruce. The method comprises two independent and automated steps. The first step is the making of "substrate plates". It consists of filling 96-well microplates with slurry suspensions of micronized substrate which are then stored frozen until use. The second step is an enzymatic activity assay. After thawing, the substrate plates are supplemented by the robot with cell-wall degrading enzymes where necessary, and the whole process from addition of enzymes to quantification of released sugars is autonomously performed by the robot. We describe how critical parameters (amount of substrate, amount of enzyme, incubation duration and temperature were selected to fit with our specific use. The ability of this automated small-scale assay to discriminate among different enzymatic activities was validated using a set of commercial enzymes. Conclusions Using an automatic microplate sealer solved three main problems generally encountered during the set-up of methods for measuring the sugar-releasing activity of plant cell wall-degrading enzymes: throughput, automation, and evaporation losses. In its present set-up, the

  14. GAMMA-CLOUD: a computer code for calculating gamma-exposure due to a radioactive cloud released from a point source

    Energy Technology Data Exchange (ETDEWEB)

    Sugimoto, O [Chugoku Electric Power Co. Inc., Hiroshima (Japan); Sawaguchi, Y; Kaneko, M

    1979-03-01

    A computer code, designated GAMMA-CLOUD, has been developed by specialists of electric power companies to meet requests from the companies to have a unified means of calculating annual external doses from routine releases of radioactive gaseous effluents from nuclear power plants, based on the Japan Atomic Energy Commission's guides for environmental dose evaluation. GAMMA-CLOUD is written in FORTRAN language and its required capacity is less than 100 kilobytes. The average ..gamma..-exposure at an observation point can be calculated within a few minutes with comparable precision to other existing codes.

  15. Release of doxorubicin from hydrogels of poly-2-hydroxyethyl methacrylate-co-acrylamide obtained by gamma radiations

    International Nuclear Information System (INIS)

    Rodriguez Rodriguez, A.; Rapado Paneque, M.; Covac Peniche, C.

    2013-01-01

    The release matrixes used were a hydrogel based on HEMA-co-AAm copolymers obtained by gamma radiation; the synthesis was conducted by varying the absorbed dose with the same composition, with the aim to establish the swelling behavior according to the absorbed dose in synthesis. Similarly was settled release profiles of doxorubicin. The mechanism of drug diffusion was established. (Author)

  16. Attenuation correction for the collimated gamma ray assay of cylindrical samples

    International Nuclear Information System (INIS)

    Patra, Sabyasachi; Agarwal, Chhavi; Goswami, A.; Gathibandhe, M.

    2015-01-01

    The Hybrid Monte Carlo (HMC) method developed earlier for attenuation correction of non-collimated samples [Agarwal et al., 2008, Nucl. Instrum. Methods A 597, 198], has been extended to the segmented gamma ray assay of cylindrical samples. The method has been validated both experimentally and theoretically. For experimental validation, the results of HMC calculation have been compared with the experimentally obtained attenuation correction factors. The HMC attenuation correction factors have also been compared with the results obtained from literature available near-field and far-field formulae at two sample-to-detector distances (10.3 cm and 20.4 cm). The method has been found to be valid at all sample-to-detector distances over a wide range of transmittance. On the other hand, the literature available near-field and far-field formulae have been found to work over a limited range of sample-to detector distances and transmittances. The HMC method has been further extended to circular collimated geometries where analytical formula for attenuation correction does not exist. - Highlights: • Hybrid Monte Carlo method for attenuation correction developed for SGA system. • Method found to work for all sample-detector geometries for all transmittances. • The near-field formula applicable only after certain sample-detector distance. • The far-field formula applicable only for higher transmittances (>18%). • Hybrid Monte Carlo method further extended to circular collimated geometry

  17. Determination of the radionuclide release factor for an evaporator process using nondestructive assay

    International Nuclear Information System (INIS)

    Johnson, R.E.

    1998-01-01

    The 242-A Evaporator is the primary waste evaporator for the Hanford Site radioactive liquid waste stored in underground double-shell tanks. Low pressure evaporation is used to remove water from the waste, thus reducing the amount of tank space required for storage. The process produces a concentrated slurry, a process condensate, and an offgas. The offgas exhausts through two stages of high-efficiency particulate air (HEPA) filters before being discharged to the atmosphere 40 CFR 61 Subpart H requires assessment of the unfiltered exhaust to determine if continuous compliant sampling is required. Because potential (unfiltered) emissions are not measured, methods have been developed to estimate these emissions. One of the methods accepted by the Environmental Protection Agency is the measurement of the accumulation of radionuclides on the HEPA filters. Nondestructive assay (NDA) was selected for determining the accumulation on the HEPA filters. NDA was performed on the HEPA filters before and after a campaign in 1997. NDA results indicate that 2.1 E+4 becquerels of cesium-137 were accumulated on the primary HEPA 1700 filter during the campaign. The feed material processed in the campaign contained a total of 1.4 E+l6 Bq of cesium-137. The release factor for the evaporator process is 1.5 E-12. Based on this release factor, continuous compliant sampling is not required

  18. Measurement of gamma-aminobutyric acid in human cerebrospinal fluid: radioreceptor assay using [3H]muscimol

    International Nuclear Information System (INIS)

    Baraczka, K.; Sperk, G.

    1981-01-01

    A method is described for the determination of gamma-aminobutyric acid (GABA) levels in human cerebrospinal fluid by modification of the radioreceptor assay utilizing [ 3 H]muscimol as labelled ligand. This method is compared with the radioreceptor assay using [ 3 H]GABA as labelled ligand. Although the [ 3 H]muscimol assay is less sensitive than the [ 3 H]GABA method, it offers the advantage of being more rapid due to the use of a filtration step instead of the usual, more time-consuming centrifugation of the samples. Samples of CSF of patients with various neurological or psychiatric disturbances were analysed. There was a satisfactory correlation between the GABA values obtained by the two assays. (Auth.)

  19. Innovative Applications of In Situ Gamma Spectroscopy for Non-destructive Assay of Transuranic Wastes

    International Nuclear Information System (INIS)

    Watters, D.J.; Weismann, J.J.; Duke, S.J.; Nicosia, W.C.

    2009-01-01

    Cabrera Services (CABRERA), under contract to National Security Technologies, LLC (NSTec), supported the transuranic (TRU) waste reduction initiative at the Radioactive Waste Management Complex of the Nevada Test Site (NTS). CABRERA developed advanced NDA techniques for oversized boxes (OSB) and drums using in situ gamma spectroscopy during several phases of the project. A more thorough characterization method was employed during the planning phase of the project to better understand the TRU content and distribution within each container, while a comprehensive NDA program was designed and implemented during the intrusive phase that guided waste segregation and re-packaging of both TRU and low-level wastes (LLW). NSTec took receipt of 58 oversized boxes of suspect TRU waste from Lawrence Livermore National Lab (LLNL). TRU waste is defined as greater than 3.7 kilobecquerels per gram [kBq/g] (100 nanocuries (nCi)/g) activity from alpha-emitting radionuclides with atomic number greater than 92 having a half-life greater than 20 years. Each box was custom-made to house a variety of suspect TRU wastes resulting from years of weapons program research, development, and testing. Since their arrival at NTS, the boxes have undergone several iterations of non-destructive assay (NDA) in preparation for the comprehensive repackaging effort. NDA has included two rounds of in situ gamma spectroscopy and real-time radiography (RTR) scans that were videotaped. Contents have been confirmed to include glove boxes, HEPA filters and their housings, and assorted process equipment and piping. TRU content was determined via directly measuring plutonium-239 (Pu-239), americium-241 (Am-241), and other radionuclides, while adding calculated results for non-measurable nuclides using reliable scaling factors developed from acceptable knowledge (AK). Advantages of CABRERA's NDA methods included: - More NDA information is available in the same amount of counting time, allowing NSTec to make more

  20. Use of calibration standards and the correction for sample self-attenuation in gamma-ray nondestructive assay

    International Nuclear Information System (INIS)

    Parker, J.L.

    1984-08-01

    The efficient use of appropriate calibration standards and the correction for the attenuation of the gamma rays within an assay sample by the sample itself are two important and closely related subjects in gamma-ray nondestructive assay. Much research relating to those subjects has been done in the Nuclear Safeguards Research and Development program at the Los Alamos National Laboratory since 1970. This report brings together most of the significant results of that research. Also discussed are the nature of appropriate calibration standards and the necessary conditions on the composition, size, and shape of the samples to allow accurate assays. Procedures for determining the correction for the sample self-attenuation are described at length including both general principles and several specific useful cases. The most useful concept is that knowing the linear attenuation coefficient of the sample (which can usually be determined) and the size and shape of the sample and its position relative to the detector permits the computation of the correction factor for the self-attenuation. A major objective of the report is to explain how the procedures for determining the self-attenuation correction factor can be applied so that calibration standards can be entirely appropriate without being particularly similar, either physically or chemically, to the items to be assayed. This permits minimization of the number of standards required to assay items with a wide range of size, shape, and chemical composition. 17 references, 18 figures, 2 tables

  1. The use of calibration standards and the correction for sample self-attenuation in gamma-ray nondestructive assay

    International Nuclear Information System (INIS)

    Parker, J.L.

    1986-11-01

    The efficient use of appropriate calibration standards and the correction for the attenuation of the gamma rays within an assay sample by the sample itself are two important and closely related subjects in gamma-ray nondestructive assay. Much research relating to those subjects has been done in the Nuclear Safeguards Research and Development program at the Los Alamos National Laboratory since 1970. This report brings together most of the significant results of that research. Also discussed are the nature of appropriate calibration standards and the necessary conditions on the composition, size, and shape of the samples to allow accurate assays. Procedures for determining the correction for the sample self-attenuation are described at length including both general principles and several specific useful cases. The most useful concept is that knowing the linear attenuation coefficient of the sample (which can usually be determined) and the size and shape of the sample and its position relative to the detector permits the computation of the correction factor for the self-attenuation. A major objective of the report is to explain how the procedures for determining the self-attenuation correction factor can be applied so that calibration standards can be entirely appropriate without being particularly similar, either physically or chemically, to the items to be assayed. This permits minimization of the number of standards required to assay items with a wide range of size, shape, and chemical composition

  2. Validation of Non-Invasive Waste Assay System (Gamma Box Counter) Performance at AECL Whiteshell Laboratories - 13136

    International Nuclear Information System (INIS)

    Attas, E.M.; Bialas, E.; Rhodes, M.J.

    2013-01-01

    Low-level radioactive waste (LLW) in solid form, resulting from decommissioning and operations activities at AECL's Whiteshell Laboratories (WL), is packaged in B-25 and B-1000 standard waste containers and characterized before it is shipped to an on-site interim storage facility, pending AECL decisions on long term management of its LLW. Assay of the waste packages before shipment contributes to an inventory of the interim storage facility and provides data to support acceptance at a future repository. A key characterization step is a gamma spectrometric measurement carried out under standard conditions using an automated, multi-detector Waste Assay System (WAS), purchased from Antech Corporation. A combination of ORTEC gamma acquisition software and custom software is used in this system to incorporate multiple measurements from two collimated high-resolution detectors. The software corrects the intensities of the gamma spectral lines for geometry and attenuation, and generates a table of calculated activities or limits of detection for a user-defined list of radioisotopes that may potentially be present. Validation of WAS performance was a prerequisite to routine operation. Documentation of the validation process provides assurance of the quality of the results produced, which may be needed one or two decades after they were generated. Aspects of the validation included setting up a quality control routine, measurements of standard point sources in reproducible positions, study of the gamma background, optimization of user-selectable software parameters, investigation of the effect of non-uniform distribution of materials and radionuclides, and comparison of results with measurements made using other gamma detector systems designed to assay bulk materials. The following key components of the validation process have been established. A daily quality control routine has been instituted, to verify stability of the gamma detector operation and the background levels

  3. A novel multiparametric flow cytometry-based cytotoxicity assay simultaneously immunophenotypes effector cells: Comparisons to a 4 h 51Cr-release assay

    OpenAIRE

    Kim, GG; Donnenberg, VS; Donnenberg, AD; Gooding, W; Whiteside, TL

    2007-01-01

    Natural killer (NK) cell- or T cell-mediated cytotoxicity traditionally is measured in 4-16h 51Cr-release assays (CRA). A new four-color flow cytometry-based cytotoxicity assay (FCC) was developed to simultaneously measure NK cell cytotoxicity and NK cell phenotype (CD3−CD16+CD56+). Target cells, K562 or Daudi, were labeled with Cell Tracker Orange (CTO) prior to the addition of effector cells. Following co-incubation, 7 amino-actinomycin D (7-AAD) was added to measure death of target cells. ...

  4. Diagnosis of Coxiella burnetii infection: comparison of a whole blood interferon-gamma production assay and a Coxiella ELISPOT.

    Directory of Open Access Journals (Sweden)

    Teske Schoffelen

    Full Text Available Diagnosis of ongoing or past infection with Coxiella burnetii, the causative agent of Q fever, relies heavily on serology: the measurement of C. burnetii-specific antibodies, reflecting the host's humoral immune response. However, cell-mediated immune responses play an important, probably even more relevant, role in infections caused by the intracellular C. burnetii bacterium. Recent studies have investigated interferon-gamma (IFN-γ based assays, including a whole-blood IFN-γ production assay and a Coxiella enzyme-linked immunospot (Coxiella ELISPOT, as potential diagnostic tools for Q fever diagnosis. Both are in-house developed assays using stimulating antigens of different origin. The main objective of this study was to compare the test performance of the IFN-γ production assay and the Coxiella ELISPOT for detecting a cellular immune response to C. burnetii in Q fever patients, and to assess the correlation between both assays. To that end, both tests were performed in a well-defined patient group of chronic Q fever patients (n = 16 and a group of healthy seronegative individuals (n = 17. Among patients, both the Coxiella ELISPOT and the IFN-γ production assay detected positive response in 14/16. Among controls, none were positive in the Coxiella ELISPOT, whereas the IFN-γ production assay detected positive results in 1/17 and 3/17, when using Henzerling and Nine Mile as stimulating antigens, respectively. These results suggest the Coxiella ELISPOT has a somewhat higher specificity than the IFN-γ production assay when Nine Mile is used as antigen stimulus. The assays showed moderate correlation: the Spearman correlation coefficient r ranged between 0.37-0.60, depending on the antigens used. Further investigation of the diagnostic potential for C. burnetii infection of both assays is warranted.

  5. RSAC-6, Gamma doses, inhalation and ingestion doses, fission products inventory after fission products release

    International Nuclear Information System (INIS)

    Wenzel, Douglas R.; Schrader, Brad J.

    2007-01-01

    1 - Description of program or function: RSAC-6 is the latest version of the program RSAC (Radiological Safety Analysis Computer Program). It calculates the consequences of a release of radionuclides to the atmosphere. Using a personal computer, a user can generate a fission product inventory; decay and in-grow the inventory during transport through processes, facilities, and the environment; model the downwind dispersion of the activity; and calculate doses to downwind individuals. Internal dose from the inhalation and ingestion pathways is calculated. External dose from ground surface and plume gamma pathways is calculated. New and exciting updates to the program include the ability to evaluate a release to an enclosed room, resuspension of deposited activity and evaluation of a release up to 1 meter from the release point. Enhanced tools are included for dry deposition, building wake, occupancy factors, respirable fraction, AMAD adjustment, updated and enhanced radionuclide inventory and inclusion of the dose-conversion factors from FOR 11 and 12. 2 - Methods: RSAC6 calculates meteorological dispersion in the atmosphere using Gaussian plume diffusion for Pasquill-Gifford, Hilmeier-Gifford and Markee models. A unique capability is the ability to model Class F fumigation conditions, the meteorological condition that causes the highest ground level concentrations from an elevated release. Doses may be calculated for various pathways including inhalation, ingestion, ground surface, air immersion, water immersion pathways. Dose calculations may be made for either acute or chronic releases. Internal doses (inhalation and ingestion) are calculated using the ICRP-30 model with dose conversion factors from FOR 11. External factors are calculated using FOR 12. 3 - Unusual Features: RSAC6 calculates complete progeny in-growth and decay during all accident phases. The calculation of fission product inventories in particularly useful in the analysis of accidents where the

  6. Studies of methotrexate-induced limb dysplasias utilizing a 51chromium release assay

    International Nuclear Information System (INIS)

    Brewton, R.G.; MacCabe, J.A.

    1990-01-01

    The folate antagonist methotrexate (MTX), widely used in chemotherapy, is a well-documented teratogen. However, the mechanism by which it exerts its effects is still unclear. Specifically, we have examined the cytotoxicity of MTX in vivo and in vitro and have looked at the relationship between cytotoxicity and teratogenesis. The chick embryo was utilized to examine the effects of the drug administered to carefully staged embryos. Embryos were exposed at stages 18-22 and examined on day 11 of incubation. Wings were malformed in a stage-dependent manner while legs were affected similarly at each stage used. A modification of the 51chromium-release assay was used to test the toxicity of MTX to limb cells in vitro. None of the tissues tested showed measurable toxicity in vitro even though the drug kills cells in vivo, thereby suggesting that MTX may be metabolized differently in vitro. Malformations induced by MTX do not seem to be due to changes in the amount of cell death taking place in the limb but may be caused by a transient inhibition of cell division

  7. Use of Novel Recombinant Antigens in the Interferon Gamma Assay for Detection of Mycobacterium Avium Subsp. Paratuberculosis Infection in Cattle

    DEFF Research Database (Denmark)

    Mikkelsen, Heidi; Aagaard, Claus; Nielsen, Søren Saxmose

    2012-01-01

    of the study were to evaluate immunogenicity and specificity of 14 novel recombinant antigens for use in the IFN-γ assay and to assess the consistency of IFN-γ responses. The antigens used were 4 ESAT-6 family members, 4 latency proteins, 4 secreted proteins including Ag85B, 3 other antigens and PPDj......Early stage Mycobacterium avium subsp. paratuberculosis (MAP) infection can be detected by measuring antigen specific cell mediated immune responses by the interferon gamma (IFN-γ) assay. Available IFN-γ assay use purified protein derivate of Johnin (PPDj) leading to low specificity. The objectives...... of the infected and non-infected herds were significantly (Passay using PPDj did not correlate with the results using the novel antigens since 5 of the 17 animals that were positive to PPDj were...

  8. The CXC chemokines gamma interferon (IFN-gamma)-inducible protein 10 and monokine induced by IFN-gamma are released during severe melioidosis

    NARCIS (Netherlands)

    Lauw, F. N.; Simpson, A. J.; Prins, J. M.; van Deventer, S. J.; Chaowagul, W.; White, N. J.; van der Poll, T.

    2000-01-01

    Gamma interferon (IFN-gamma)-inducible protein 10 (IP-10) and monokine induced by IFN-gamma (Mig) are related CXC chemokines which bind to the CXCR3 receptor and specifically target activated T lymphocytes and natural killer (NK) cells. The production of IP-10 and Mig by various cell types in vitro

  9. Interleukin 12 in part regulates gamma interferon release in human whole blood stimulated with Leptospira interrogans

    NARCIS (Netherlands)

    de Fost, Maaike; Hartskeerl, Rudy A.; Groenendijk, Martijn R.; van der Poll, Tom

    2003-01-01

    Heat-killed pathogenic Leptospira interrogans serovar rachmati induced the production of gamma interferon (IFN-gamma) and the IFN-gamma-inducing cytokines interleukin-12p40 (IL-12p40) and tumor necrosis factor alpha in human whole blood in vitro. The production of IFN-gamma was largely dependent on

  10. A prototype of radioactive waste drum monitor by non-destructive assays using gamma spectrometry

    International Nuclear Information System (INIS)

    Thanh, Tran Thien; Trang, Hoang Thi Kieu; Chuong, Huynh Dinh; Nguyen, Vo Hoang; Tran, Le Bao; Tam, Hoang Duc; Tao, Chau Van

    2016-01-01

    In this work, segmented gamma scanning and the gamma emission tomography were used to locate unknown sources in a radioactive waste drum. The simulated detector response function and full energy peak efficiency are compared to corresponding experimental data and show about 5.3% difference for an energy ranging from 81 keV to 1332.5 keV for point sources. Computation of the corresponding activity is in good agreement with the true values. - Highlights: • Segmented gamma scanning and gamma emission tomography are used to locate point source in waste drums. • The PENELOPE software is used to compute the detection efficiency of the localized point source in the waste drum. • The activity of "1"3"7Cs and "6"0Co point source could be determined with an accuracy better than 10% for air and sand matrices.

  11. Non-Tuberculous Mycobacteria and the Performance of Interferon Gamma Release Assays in Denmark

    DEFF Research Database (Denmark)

    Hermansen, Thomas Stig; Thomsen, Vibeke Østergaard; Lillebaek, Troels

    2014-01-01

    , nationwide patient data on positive NTM cultures (n = 925) were combined with nationwide data on QFT results (n = 16,133), both retrieved from the International Reference Laboratory of Mycobacteriology, Denmark. A total of 112 patients with NTM infections had a QFT performed, 53 patients had definite NTM...... disease, 10 had possible disease and 49 had NTM colonization. RESULTS: QFT was positive in 8% (4/53) of patients with definite disease, 40% (4/10) with possible disease and 31% (15/49) with colonization. Positivity rate was lowest among patients with definite disease infected with NTM without the RD1...

  12. Inverse modelling of radionuclide release rates using gamma dose rate observations

    Science.gov (United States)

    Hamburger, Thomas; Evangeliou, Nikolaos; Stohl, Andreas; von Haustein, Christoph; Thummerer, Severin; Wallner, Christian

    2015-04-01

    Severe accidents in nuclear power plants such as the historical accident in Chernobyl 1986 or the more recent disaster in the Fukushima Dai-ichi nuclear power plant in 2011 have drastic impacts on the population and environment. Observations and dispersion modelling of the released radionuclides help to assess the regional impact of such nuclear accidents. Modelling the increase of regional radionuclide activity concentrations, which results from nuclear accidents, underlies a multiplicity of uncertainties. One of the most significant uncertainties is the estimation of the source term. That is, the time dependent quantification of the released spectrum of radionuclides during the course of the nuclear accident. The quantification of the source term may either remain uncertain (e.g. Chernobyl, Devell et al., 1995) or rely on estimates given by the operators of the nuclear power plant. Precise measurements are mostly missing due to practical limitations during the accident. The release rates of radionuclides at the accident site can be estimated using inverse modelling (Davoine and Bocquet, 2007). The accuracy of the method depends amongst others on the availability, reliability and the resolution in time and space of the used observations. Radionuclide activity concentrations are observed on a relatively sparse grid and the temporal resolution of available data may be low within the order of hours or a day. Gamma dose rates, on the other hand, are observed routinely on a much denser grid and higher temporal resolution and provide therefore a wider basis for inverse modelling (Saunier et al., 2013). We present a new inversion approach, which combines an atmospheric dispersion model and observations of radionuclide activity concentrations and gamma dose rates to obtain the source term of radionuclides. We use the Lagrangian particle dispersion model FLEXPART (Stohl et al., 1998; Stohl et al., 2005) to model the atmospheric transport of the released radionuclides. The

  13. Successful Application of the Gamma-Interferon Assay in a Bovine Tuberculosis Eradication Program: The French Bullfighting Herd Experience.

    Science.gov (United States)

    Keck, Nicolas; Boschiroli, Maria-Laura; Smyej, Florence; Vogler, Valérie; Moyen, Jean-Louis; Desvaux, Stéphanie

    2018-01-01

    In the French Camargue region, where bovine tuberculosis had been enzootic for several years in bullfighting cattle herds, the gamma-interferon (IFN) assay was used since 2003 in parallel with the intradermal test in order to increase overall disease detection sensitivity in infected herds. This study presents the results of a field-evaluation of the assay during a 10-year period (2004-2014) of disease control and surveillance program and explores the particular pattern of IFN assay results in bullfight herds in comparison to cattle from other regions of France. The low sensitivity [59.2% (50.6; 67.3)] of IFN assay using the tuberculin stimulation could be related to the poor gamma-IFN production from bullfight cattle blood cells which is significantly lower than in animals of conventional breeds. The characteristics of the assay were progressively adapted to the epidemiological situation and the desired strategic applications. Data analysis with a receiver operating characteristic curve based on a simple S/P value algorithm allowed for the determination of a new cutoff adapted for a global screening, giving a high specificity of 99.9% results and a high accuracy of the assay. Having regularly risen to above 5% since 2005, with a peak around 10% in 2010, the annual incidence dropped to under 1% in 2014. The positive predictive value relative to the bacteriological confirmation evolved during the years, from 33% in 2009 to 12% during the last screening period, a normal trend in a context of decreasing prevalence. The estimated rate of false-positive reactions during screening campaigns was 0.67%, confirming the high specificity of the test, measured in bTB negative herds, in this epidemiological context. The proportion of false-positive reactions decreased with the age and was higher in males than in females. Although these results indicate that the IFN assay is accurate in the field, it also emphasizes great differences between interferon quantities produced by

  14. Implementation of a new gamma spectrometer on the MERARG loop: Application to the volatile fission products release measurement

    Energy Technology Data Exchange (ETDEWEB)

    Bernard, S.; Gleizes, B.; Pontillon, Y.; Hanus, E.; Ducros, G. [CEA, DEN, DEC, SA3C, F-13108, Saint Paul lez Durance, (France); Roure, C. [CEA, DEN, DTN, SMTA, F-13108, Saint Paul lez Durance, (France)

    2015-07-01

    The MERARG facility initially aims at the annealing of irradiated fuel samples to study the gaseous fission products release kinetics. In order to complete the evaluation of the source term potentially released during accidental situation, the MERARG experimental circuit has been enhanced with a new gamma spectrometer. This one is directly sighting the fuel and is devoted to the fission products release kinetics. Because of the specificities of the fuel measurements, it has been dimensioned and designed to match the specific requirements. The acquisition chain and the collimation system have been optimized for this purpose and a first set of two experiments have shown the good functioning of this new spectrometry facility. (authors)

  15. Bias in segmented gamma scans arising from size differences between calibration standards and assay samples

    International Nuclear Information System (INIS)

    Sampson, T.E.

    1991-01-01

    Recent advances in segmented gamma scanning have emphasized software corrections for gamma-ray self-adsorption in particulates or lumps of special nuclear material in the sample. another feature of this software is an attenuation correction factor formalism that explicitly accounts for differences in sample container size and composition between the calibration standards and the individual items being measured. Software without this container-size correction produces biases when the unknowns are not packaged in the same containers as the calibration standards. This new software allows the use of different size and composition containers for standards and unknowns, as enormous savings considering the expense of multiple calibration standard sets otherwise needed. This paper presents calculations of the bias resulting from not using this new formalism. These calculations may be used to estimate bias corrections for segmented gamma scanners that do not incorporate these advanced concepts

  16. Non-destructive assay of mechanical components using gamma-rays and thermal neutrons

    Energy Technology Data Exchange (ETDEWEB)

    Souza, Erica Silvani; Avelino, Mila R. [PPG-EM/UERJ, R. Sao Francisco Xavier, 524, Maracana - Rio de Janeiro - RJ (Brazil); Almeida, Gevaldo L. de; Souza, Maria Ines S. [IEN/CNEN, Rua Helio de Almeida, 75, Ilha do Fundao, Rio de Janeiro - RJ (Brazil)

    2013-05-06

    This work presents the results obtained in the inspection of several mechanical components through neutron and gamma-ray transmission radiography. The 4.46 Multiplication-Sign 10{sup 5} n.cm{sup -2}.s{sup -1} thermal neutron flux available at the main port of the Argonauta research reactor in Instituto de Engenharia Nuclear has been used as source for the neutron radiographic imaging. The 412 keV {gamma}-ray emitted by {sup 198}Au, also produced in that reactor, has been used as interrogation agent for the gamma radiography. Imaging Plates - IP specifically designed to operate with thermal neutrons or with X-rays have been employed as detectors and storage devices for each of these radiations.

  17. In vitro immunomodulation of a whole blood IFN-γ release assay enhances T cell responses in subjects with latent tuberculosis infection.

    Directory of Open Access Journals (Sweden)

    Rajiv L Gaur

    Full Text Available Activation of innate immunity via pathogen recognition receptors (PRR modulates adaptive immune responses. PRR ligands are being exploited as vaccine adjuvants and as therapeutics, but their utility in diagnostics has not been explored. Interferon-gamma (IFN-γ release assays (IGRAs are functional T cell assays used to diagnose latent tuberculosis infection (LTBI; however, novel approaches are needed to improve their sensitivity.In vitro immunomodulation of a whole blood IGRA (QuantiFERON®-TB GOLD In-Tube with Toll-like receptor agonists poly(I:C, LPS, and imiquimod was performed on blood from subjects with LTBI and negative controls.In vitro immunomodulation significantly enhanced the response of T cells stimulated with M. tuberculosis antigens from subjects with LTBI but not from uninfected controls. Immunomodulation of IGRA revealed T cell responses in subjects with LTBI whose T cells otherwise do not respond to in vitro stimulation with antigens alone. Similar to their in vivo functions, addition of poly(I:C and LPS to whole blood induced secretion of inflammatory cytokines and IFN-α and enhanced the surface expression of antigen presenting and costimulatory molecules on antigen presenting cells.In vitro immunomodulation of whole blood IGRA may be an effective strategy for enhancing the sensitivity of T cells for diagnosis of LTBI.

  18. [IFN-gamma enzyme-linked immunospot assay versus PPD tuberculin skin test in the diagnosis of tuberculous epididymitis].

    Science.gov (United States)

    Huang, Hao; Yang, Xi-Fei; Deng, Qun-Yi; Li, Bing; Liu, Guo-Hui; Zhang, Jie-Yun; Yang, Da-Fei

    2012-06-01

    To explore the potential application of IFN-gamma enzyme-linked immunospot (ELISPOT) assay in the diagnosis of tuberculous epididymitis (TE) by comparing ELISPOT assay with the traditional purified protein derivative (PPD) tuberculin skin test. We examined 13 TE patients using an in-house ELISPOT kit, another 11 TE patients by PPD skin testing, and 57 healthy male volunteers by parallel test with both the methods. Twelve (92.3%) of the 13 TE cases were positive on ELISPOT assay, and 10 (90.9%) of the 11 TE cases positive on PPD skin test, with no statistically significant differences between the two groups (P > 0.05). Among the 57 healthy male volunteers, 8 (14.0%) were positive on ELISPOT, and 28 (49.1%) positive on PPD test, the latter significantly higher than the former (P PPD test in the examination of tuberculous epididymitis. As for specificity, ELISPOT assay seems better than PPD test in differentiating tuberculous epididymitis patients from healthy males.

  19. A novel multiparametric flow cytometry-based cytotoxicity assay simultaneously immunophenotypes effector cells: comparisons to a 4 h 51Cr-release assay.

    Science.gov (United States)

    Kim, G G; Donnenberg, V S; Donnenberg, A D; Gooding, W; Whiteside, T L

    2007-08-31

    Natural killer (NK) cell-or T cell-mediated cytotoxicity traditionally is measured in 4-16 h (51)Cr-release assays (CRA). A new four-color flow cytometry-based cytotoxicity assay (FCC) was developed to simultaneously measure NK cell cytotoxicity and NK cell phenotype (CD3(-)CD16(+)CD56(+)). Target cells, K562 or Daudi, were labeled with Cell Tracker Orange (CTO) prior to the addition of effector cells. Following co-incubation, 7 amino-actinomycin D (7-AAD) was added to measure death of target cells. The phenotype of effectors, viability of targets, the formation of tumor-effector cell conjugates and absolute numbers of all cells were measured based on light scatter (FSC/SSC), double discrimination of the fluorescence peak integral and height, and fluorescence intensity. Kinetic studies (0.5 and 1 to 4 h) at different effector to target (E:T) cell ratios (50, 25, 12, and 6) confirmed that the 3 h incubation was optimal. The FCC assay is more sensitive than the CRA, has a coefficient of variation (CV) 8-13% and reliably measures NK cell-or lymphokine-activated killer (LAK) cell-mediated killing of target cells in normal controls and subjects with cancer. The FCC assay can be used to study a range of phenotypic attributes, in addition to lytic activity of various subsets of effector cells, without radioactive tracers and thus, it is relatively inexpensive. The FCC assay has a potential for providing information about molecular interactions underlying target cell lysis and thus becoming a major tool for studies of disease pathogenesis as well as development of novel immune therapies.

  20. Comparison of two interferon-gamma assays and tuberculin skin test for tracing tuberculosis contacts

    NARCIS (Netherlands)

    Arend, Sandra M.; Thijsen, Steven F. T.; Leyten, Eliane M. S.; Bouwman, John J. M.; Franken, Willeke P. J.; Koster, Ben F. P. J.; Cobelens, Frank G. J.; van Houte, Arend-Jan; Bossink, Ailko W. J.

    2007-01-01

    The tuberculin skin test (TST) has low specificity. QuantiFERON-TB Gold (QFT-G) and T-SPOT.TB are based on interferon (IFN)-gamma responses to Mycobacterium tuberculosis-specific antigens. A novel in-tube format of QFT-G (QFT-GIT) offers logistical advantages. To compare TST, QFT-GIT, and T-SPOT.TB

  1. Delayed Gamma-Ray Spectroscopy for Non-Destructive Assay of Nuclear Materials

    Energy Technology Data Exchange (ETDEWEB)

    Ludewigt, Bernhard [Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States); Mozin, Vladimir [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States); Campbell, Luke [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Favalli, Andrea [Los Alamos National Lab. (LANL), Los Alamos, NM (United States); Hunt, Alan W. [Iowa State Univ., Ames, IA (United States); Reedy, Edward T.E. [Iowa State Univ., Ames, IA (United States); Seipel, Heather A. [Iowa State Univ., Ames, IA (United States)

    2015-09-28

    This project has been a collaborative effort of researchers from four National Laboratories, Lawrence Berkley National Laboratory (LBNL), Lawrence Livermore National Laboratory (LLNL), Los Alamos National Laboratory (LANL), Pacific Northwest National Laboratory (PNNL), and Idaho State University’s (ISU) Idaho Accelerator Center (IAC). Experimental measurements at the Oregon State University (OSU) were also supported. The research included two key components, a strong experimental campaign to characterize the delayed gamma-ray signatures of the isotopes of interests and of combined targets, and a closely linked modeling effort to assess system designs and applications. Experimental measurements were performed to evaluate fission fragment yields, to test methods for determining isotopic fractions, and to benchmark the modeling code package. Detailed signature knowledge is essential for analyzing the capabilities of the delayed gamma technique, optimizing measurement parameters, and specifying neutron source and gamma-ray detection system requirements. The research was divided into three tasks: experimental measurements, characterization of fission yields, and development of analysis methods (task 1), modeling in support of experiment design and analysis and for the assessment of applications (task 2), and high-rate gamma-ray detector studies (task 3).

  2. Achieving Higher Accuracy in the Gamma-Ray Spectrocopic Assay of Holdup

    International Nuclear Information System (INIS)

    Russo, P.A.; Wenz, T.R.; Smith, S.E.; Harris, J.F.

    2000-01-01

    Gamma-ray spectroscopy is an important technique for the measurement of quantities of nuclear material holdup in processing equipment. Because the equipment in large facilities dedicated to uranium isotopic enrichment, uranium/plutonium scrap recovery or various stages of fuel fabrication is extensive, the total holdup may be large by its distribution alone, even if deposit thicknesses are small. Good accountability practices require unbiased measurements with uncertainties that are as small as possible. This paper describes new procedures for use with traditional holdup analysis methods based on gamma-ray spectroscopy. The procedures address the two sources of bias inherent in traditional gamma-ray measurements of holdup. Holdup measurements are performed with collimated, shielded gamma-ray detectors. The measurement distance is chosen to simplify the deposit geometry to that of a point, line or area. The quantitative holdup result is based on the net count rate of a representative gamma ray. This rate is corrected for contributions from room background and for attenuation by the process equipment. Traditional holdup measurements assume that the width of the point or line deposit is very small compared to the measurement distance, and that the self-attenuation effects can be neglected. Because each point or line deposit has a finite width and because self-attenuation affects all measurements, bias is incurred in both assumptions. In both cases the bias is negative, explaining the systematically low results of gamma-ray holdup measurements. The new procedures correct for bias that arises from both the finite-source effects and the gamma-ray self-attenuation. The procedures used to correct for both of these effects apply to the generalized geometries. One common empirical parameter is used for both corrections. It self-consistently limits the total error incurred (from uncertain knowledge of this parameter) in the combined correction process, so that it is

  3. Development and release of gamma ray induced sesame mutant ANK-S2 in Sri Lanka

    International Nuclear Information System (INIS)

    Weerasena, L.A.; Bandara, Priyanthi; Pathirana, R.

    2001-01-01

    Epiphytotic conditions and lack of resistant germplasm in sesame (Sesamum indicum L.) prompted the use of mutation induction techniques to develop a variety resistant to Phytophthora blight caused by Phytophthora nicotianae var. parasitica. Dry seeds of three varieties were irradiated with six doses of 60 Co gamma rays in the range 100-700 Gy. The mutant line 182/3 of variety MI-3 selected from 200 Gy dose treatment in M 2 showed tolerance to the disease in subsequent testing at Angunakolapelessa in the disease nursery. The mutant line was tested in the major yield trial, National Co-ordinated Variety Trials and in the National Co-ordinated Variety Adaptability Trials. It was superior to MI-3 in yield and plant survival during the seasons favouring development of the disease and was similar to MI-3 and other recommended varieties in other seasons. The mutant has cream colour seeds, branched stem, and recorded 1890 kg/ha at Girandurukotte, 1593 kg ha -1 at Maha Illuppallama and 1151 kg/ha at Angunakolapelessa under rainfed conditions. The mutant was released as ANK-S2 in 1993 and may be used to increase the declining sesame area due to low yield of existing varieties and their susceptibility to disease. It should serve as a valuable parent material in cross-breeding programmes too. (author)

  4. Development and release of gamma ray induced sesame mutant ANK-S2 in Sri Lanka

    International Nuclear Information System (INIS)

    Pathirane, R.; Weerasena, L.A; Bandara, P.

    2000-01-01

    Epiphytotic conditions and non-availability of resistant germplasm prompted the use of mutation induction technique to develop a variety resistant to phytophthora blight caused by Phytophthora nicotianae var. parasitica in sesame (Sesamum indicum L.). Dry seeds of three varieties were irradiated with six doses of Co-60 gamma rays in the range 100-700 Gy. The mutant line 182/3 of variety MI 3 selected from 200 Gy dose treatment in the M2 showed tolerance to the disease at Angunakolapelessa in the disease nursery. The mutant line was tested in the advanced yield trial, National Co-ordinated Varietal Trials and in the National Coordinated Varietal Adaptability Trials. It was superior to MI 3 in yield and plant survival during the seasons favouring development of the disease and was similar to MI 3 and other recommended varieties during the other seasons. the variety has cream coloured seeds, branched stem, The mutant was released as ANK S2 in 1993 and may be used to increase the declining sesame area due to low yield of existing varieties and their susceptibility to disease. It should also serve as valuable parent material in cross-breeding programmes

  5. Can gamma irradiation during radiotherapy influence the metal release process for biomedical CoCrMo and 316L alloys?

    Science.gov (United States)

    Wei, Zheng; Edin, Jonathan; Karlsson, Anna Emelie; Petrovic, Katarina; Soroka, Inna L; Odnevall Wallinder, Inger; Hedberg, Yolanda

    2018-02-09

    The extent of metal release from implant materials that are irradiated during radiotherapy may be influenced by irradiation-formed radicals. The influence of gamma irradiation, with a total dose of relevance for radiotherapy (e.g., for cancer treatments) on the extent of metal release from biomedical stainless steel AISI 316L and a cobalt-chromium alloy (CoCrMo) was investigated in physiological relevant solutions (phosphate buffered saline with and without 10 g/L bovine serum albumin) at pH 7.3. Directly after irradiation, the released amounts of metals were significantly higher for irradiated CoCrMo as compared to nonirradiated CoCrMo, resulting in an increased surface passivation (enhanced passive conditions) that hindered further release. A similar effect was observed for 316L showing lower nickel release after 1 h of initially irradiated samples as compared to nonirradiated samples. However, the effect of irradiation (total dose of 16.5 Gy) on metal release and surface oxide composition and thickness was generally small. Most metals were released initially (within seconds) upon immersion from CoCrMo but not from 316L. Albumin induced an increased amount of released metals from AISI 316L but not from CoCrMo. Albumin was not found to aggregate to any greater extent either upon gamma irradiation or in the presence of trace metal ions, as determined using different light scattering techniques. Further studies should elucidate the effect of repeated friction and fractionated low irradiation doses on the short- and long term metal release process of biomedical materials. © 2018 Wiley Periodicals, Inc. J Biomed Mater Res Part B: Appl Biomater, 2018. © 2018 The Authors Journal of Biomedical Materials Research Part B: Applied Biomaterials Published by Wiley Periodicals, Inc.

  6. A low-background gamma-ray assay laboratory for activation analysis

    International Nuclear Information System (INIS)

    Lindstrom, R.M.; Langland, J.K.; Lindstrom, D.J.; Slaback, L.A.

    1990-01-01

    The sources of background in a gamma-ray detector were experimentally determined in underground and surface counting rooms, and an optimized shield was constructed at NIST. The optimum thickness of lead was 10-15 cm, with a greater thickness giving an increased background due to the buildup of tertiary cosmic-ray particles. Neither cadmium, tin, copper nor plastic (hydrocarbon or fluorocarbon) was desirable as a shield liner, since all these increased the background continuum or introduced characteristic peaks into the background spectrum. Two broad peaks in the background result from inelastic scattering of cosmic-ray neutrons (0.02 cm -2 s -1 ) in germanium. These neutrons also excite the lower nuclear levels of lead and structural iron to produce additional gamma-ray peaks in the spectrum. The influence of the 20 MW NIST reactor, located 60 m from the detector, was undetectable. Comparisons among detectors and locations clearly separate cosmic from environmental components of the background. (orig.)

  7. Evaluation of automated serum des-gamma-carboxyprothrombin (DCP) assays for detecting hepatocellular carcinoma.

    Science.gov (United States)

    Choi, Jonghyeon; Park, Yongjung; Kim, Jeong-Ho; Kim, Hyon-Suk

    2011-12-01

    We evaluated two new autoanalyzers, μTAS and Lumipulse for des-γ-carboxyprothrombin (DCP) assay. Analytical performance was evaluated, and the upper reference limit of the 97.5th percentile for DCP was re-established using sera from 140 healthy individuals. DCP levels were determined by the two autoanalyzers and EIA in a total of 239 sera from HCC patients (n=120) and those without HCC (n=119). Total imprecision of the two automated assays was Lumipulse. There were proportional and constant biases between the results from the autoanalyzers and those from EIA. The two newly developed DCP assays showed high analytical performance, but re-establishment of reference limits would be necessary. The new analyzers could be useful for clinical laboratories because of convenience of operation and wide AMRs. Copyright © 2011 The Canadian Society of Clinical Chemists. Published by Elsevier Inc. All rights reserved.

  8. IL-2 absorption affects IFN-gamma and IL-5, but not IL-4 producing memory T cells in double color cytokine ELISPOT assays.

    Science.gov (United States)

    Quast, Stefan; Zhang, Wenji; Shive, Carey; Kovalovski, Damian; Ott, Patrick A; Herzog, Bernhard A; Boehm, Bernhard O; Tary-Lehmann, Magdalena; Karulin, Alexey Y; Lehmann, Paul V

    2005-09-01

    Cytokine assays are gaining increasing importance for human immune monitoring because they reliably detect antigen-specific T cells in primary PBMC, even at low clonal sizes. Double color ELISPOT assays permit the simultaneous visualization of cells producing two different cytokines. Permitting the simultaneous assessment of type 1 and 2 immunity and due to the limited numbers of PBMC available from human study subjects, double color assays should be particularly attractive for clinical trials. Since the performance of double color assays has not yet been validated, we set out to compare them to single color measurements. Testing the recall antigen-induced cytokine response of PBMC, we found that double color assays regularly provided lower numbers of IFN-gamma and IL-5 spots than single color measurements when IL-2 detection was part of the double color assay. We showed that the inhibitory effect resulted from IL-2 absorption and could be overcome by either antibody free preactivation cultures or by inclusion of anti-CD28 antibody. In contrast, the simultaneous detection of IL-2 did not affect the numbers of IL-4 spots. Therefore, unlike IL-2/IL-4 and IFN-gamma/IL-5 assays, IL-2/IFN-gamma, and IL-2/IL-5 assays require compensation for the IL-2 capture to provide accurate numbers for the frequencies of cytokine producing memory T cells.

  9. Swelling and drug release behavior of poly(2-hydroxyethyl methacrylate/itaconic acid) copolymeric hydrogels obtained by gamma irradiation

    International Nuclear Information System (INIS)

    Tomic, S.Lj.; Micic, M.M.; Filipovic, J.M.; Suljovrujic, E.H.

    2007-01-01

    The new copolymeric hydrogels based on 2-hydroxyethyl methacrylate (HEMA) and itaconic acid (IA) were prepared by gamma irradiation, in order to examine the potential use of these hydrogels in controlled drug release systems. The influence of IA content in the gel on the swelling characteristics and the releasing behavior of hydrogels, and the effect of different drugs, theophylline (TPH) and fenethylline hydrochloride (FE), on the releasing behavior of P(HEMA/IA) matrix were investigated in vitro. The diffusion exponents for swelling and drug release indicate that the mechanisms of buffer uptake and drug release are governed by Fickian diffusion. The swelling kinetics and, therefore, the release rate depends on the matrix swelling degree. The drug release was faster for copolymeric hydrogels with a higher content of itaconic acid. Furthermore, the drug release for TPH as model drug was faster due to a smaller molecular size and a weaker interaction of the TPH molecules with(in) the P(HEMA/IA) copolymeric networks

  10. Controlled 5-fluorouracil release from hydrogels of Poly (acrylamide-co-metacrylic acid) crosslinked by means Of gamma irradiation techniques

    International Nuclear Information System (INIS)

    Rapado, M.; Sainz, D.; Altanes, S.; Prado, S.; Padron, S.; Salivar, D.; Chong, B.

    1999-01-01

    This report present the results on entrapped a cytostatic 5-Fluorouracil (5-F) in polymeric matrixes named hydrogels of polyacrylamide co -metacrylic acid crosslinked by means of gamma radiation with doses of 10,30, and 30 kGy at 25 o C. The drug delivery was followed by HPLC. The behavior of 5 -Fu migration from polymeric network was analyze by Iguchi equation for plain structure systems. The diffusion coefficients were obtained and drug release was in accordance with Fickian behavior

  11. Pu abundances, concentrations, and isotopics by x- and gamma-ray spectrometry assay techniques

    International Nuclear Information System (INIS)

    Camp, D.C.; Gunnink, R.; Ruhter, W.D.; Prindle, A.L.; Gomes, R.J.

    1986-01-01

    Two x- and gamma-ray systems were recently installed at-line in gloveboxes and will measure Pu solution concentrations from 5 to 105 g/L. These NDA technique, developed and refined over the past decade, are now used domestically and internationally for nuclear material process monitoring and accountability needs. In off- and at-line installations, they can measure solution concentrations to 0.2%. The K-XRFA systems use a transmission source to correct for solution density. The gamma-ray systems use peaks from 59- to 208-keV to determine solution concentrations and relative isotopics. A Pu check source monitors system stability. These two NDA techniques can be combined to form a new, NDA measurement methodology. With the instrument located outside of a glovebox, both relative Pu isotopics and absolute Pu abundances of a sample located inside a glovebox can be measured. The new technique works with either single or dual source excitation; the former for a detector 6 to 20 cm away with no geometric corrections needed; the latter requires geometric corrections or source movement if the sample cannot be measured at the calibration distance. 4 refs., 7 figs., 2 tabs

  12. A low-background gamma-ray assay laboratory for activation analysis

    Energy Technology Data Exchange (ETDEWEB)

    Lindstrom, R M; Langland, J K [National Inst. of Standards and Technology, Gaithersburg, MD (USA). Center for Analytical Chemistry; Lindstrom, D J [National Aeronautics and Space Administration, Houston, TX (USA). Lyndon B. Johnson Space Center; Slaback, L A [National Inst. of Standards and Technology, Gaithersburg, MD (USA). Occupational Health and Safety Div.

    1990-12-20

    The sources of background in a gamma-ray detector were experimentally determined in underground and surface counting rooms, and an optimized shield was constructed at NIST. The optimum thickness of lead was 10-15 cm, with a greater thickness giving an increased background due to the buildup of tertiary cosmic-ray particles. Neither cadmium, tin, copper nor plastic (hydrocarbon or fluorocarbon) was desirable as a shield liner, since all these increased the background continuum or introduced characteristic peaks into the background spectrum. Two broad peaks in the background result from inelastic scattering of cosmic-ray neutrons (0.02 cm{sup -2} s{sup -1}) in germanium. These neutrons also excite the lower nuclear levels of lead and structural iron to produce additional gamma-ray peaks in the spectrum. The influence of the 20 MW NIST reactor, located 60 m from the detector, was undetectable. Comparisons among detectors and locations clearly separate cosmic from environmental components of the background. (orig.).

  13. Quantifying the passive gamma signal from spent nuclear fuel in support of determining the plutonium content in spent nuclear fuel with nondestructive assay

    Energy Technology Data Exchange (ETDEWEB)

    Fensin, Michael L [Los Alamos National Laboratory; Tobin, Steven J [Los Alamos National Laboratory; Menlove, Howard O [Los Alamos National Laboratory; Swinhoe, Martyn T [Los Alamos National Laboratory

    2009-01-01

    The objective of safeguarding nuclear material is to deter diversions of significant quantities of nuclear materials by timely monitoring and detection. There are a variety of motivations for quantifying plutonium in spent fuel (SF), by means of nondestructive assay (NDA), in order to meet this goal. These motivations include the following: strengthening the capabilities of the International Atomic Energy Agencies ability to safeguard nuclear facilities, shipper/receiver difference, input accountability at reprocessing facilities and burnup credit at repositories. Many NDA techniques exist for measuring signatures from SF; however, no single NDA technique can, in isolation, quantify elemental plutonium in SF. A study has been undertaken to determine the best integrated combination of 13 NDA techniques for characterizing Pu mass in spent fuel. This paper focuses on the development of a passive gamma measurement system in support the spent fuel assay system. Gamma ray detection for fresh nuclear fuel focuses on gamma ray emissions that directly coincide with the actinides of interest to the assay. For example, the 186-keV gamma ray is generally used for {sup 235}U assay and the 384-keV complex is generally used for assaying plutonium. In spent nuclear fuel, these signatures cannot be detected as the Compton continuum created from the fission products dominates the signal in this energy range. For SF, the measured gamma signatures from key fission products ({sup 134}Cs, {sup 137}Cs, {sup 154}Eu) are used to ascertain burnup, cooling time, and fissile content information. In this paper the Monte Carlo modeling set-up for a passive gamma spent fuel assay system will be described. The set-up of the system includes a germanium detector and an ion chamber and will be used to gain passive gamma information that will be integrated into a system for determining Pu in SF. The passive gamma signal will be determined from a library of {approx} 100 assemblies that have been

  14. Dual isotope notch observer for isotope identification, assay and imaging with mono-energetic gamma-ray sources

    Science.gov (United States)

    Barty, Christopher P.J.

    2013-02-05

    A dual isotope notch observer for isotope identification, assay and imaging with mono-energetic gamma-ray sources includes a detector arrangement consists of three detectors downstream from the object under observation. The latter detector, which operates as a beam monitor, is an integrating detector that monitors the total beam power arriving at its surface. The first detector and the middle detector each include an integrating detector surrounding a foil. The foils of these two detectors are made of the same atomic material, but each foil is a different isotope, e.g., the first foil may comprise U235 and second foil may comprise U238. The integrating detectors surrounding these pieces of foil measure the total power scattered from the foil and can be similar in composition to the final beam monitor. Non-resonant photons will, after calibration, scatter equally from both foils.

  15. On the influence of matrix's heterogeneity on uncertainty of gamma-spectrometry at activity assay of radioactive waste

    Directory of Open Access Journals (Sweden)

    V. S. Prokopenko

    2009-09-01

    Full Text Available The influence of the waste matrix heterogeneity on the flux density value of initial gamma quanta at the transport of quanta in the matrix was considered. It is shown that the waste heterogeneity leads to the positive shift of the average flux density value comparing with corresponding value for homogeneous waste if average value of the attenuation factor in heterogeneous matrix is equal to the attenuation factor of homogeneous matrix. Due to this the activity assay of heterogeneous waste by a technique which was calibrated by using a homogeneous standard (surrogate container the measurement results will be positively shifted, or, in other words, conservative estimation of the waste activity will be obtained.

  16. Determination of assay and impurities of gamma irradiated chloramphenicol in eye ointment

    International Nuclear Information System (INIS)

    Hong, L.; Altorfer, H.R.

    2005-01-01

    A sample preparation method was developed to isolate chloramphenicol and its radiolytic products from an oily ointment base. The isolation method suspended the eye ointment in n-hexane at 45 deg C, and isolated the target compounds as residue by centrifugation. It was found that the main element to ensure a satisfactory isolation was keeping the sample solution at 45 deg C during sample preparation. Linearity, precision, accuracy and suitability of the method were confirmed valid for both assay and impurity tests. This isolation method was ideal for assay, unique for extraction of unexpected and complex radiolysis products, and had a number of advantages compared to the pretreatment methods described in the United States Pharmacopoeia and British Pharmacopoeia, in terms of accuracy, precision, and easy handling. The effect of γ-irradiation on chloramphenicol eye ointment was studied by HPLC-DAD, after applying the developed sample preparation method. The present assay and impurity test methods with HPLC-DAD were confirmed to be suitable for irradiated chloramphenicol in eye ointment. (author)

  17. Cell-mediated cytotoxicity for melanome tumor cells: detection by a (3H)proline release assay

    International Nuclear Information System (INIS)

    Saal, J.G.; Rieber, E.P.; Riethmueller, G.

    1976-01-01

    An in vitro lymphocyte-mediated cytotoxicity assay using [ 3 H]proline-labelled target cells is described. The assay, modified from an original procedure of Bean et al., assesses the release of [ 3 H]proline by filtering the total culture fluid containing both trypsinised tumor cells and effector cells. Filtration is performed with a semiautomatic harvesting device using low suction pressure and large-diameter glass filters. Pretreatment of filters with whole serum diminishes adsorption of cell-free radioactive material considerably and thus increases the sensitivity of the assay. Nearly 100% of the radioactivity could be recovered with this harvesting device. The technique allowed the detection of cytolytic activities of lymphocytes after 6 h of incubation. Lymphocytes from patients with primary malignant melanoma showed a significantly higher cytolytic reactivity (p > 0.001) than normal donors' lymphocytes against three different melanoma cell lines. In a series of parallel experiments on 36 patients and 18 normal donors, this modification of the [ 3 ]proline test was compared with three different assays: the conventional microcytotoxicity test of Takasugi and Klein, the original [ 3 H]proline microcytotoxicity test of Bean et al., and the viability count of tumor cells. (Auth.)

  18. Mutagenicity assayed by dominant lethality testing in mice fed a combined gamma-irradiated diet

    International Nuclear Information System (INIS)

    Rupova, I.; Katsarova, Ts.; Bajrakova, A.; Baev, I.; Tencheva, S.

    1980-01-01

    Mice fed a combined gamma-irradiated diet were examined for a mutagenic effect using the dominant lethality test. Their feed contained the following irradiated ingredients: 20% maize, 10% dried plums, and 5% walnut kernels. Taking into account cycle duration in spermatogenesis and oogenesis, males were fed this special diet throughout 56 days, and females throughout 21 days. The experiments involved three animal groups: (1) fed the special diet containing irradiated ingredients; (2) fed the special diet but with the ingredients nonirradiated; and (3) fed standard vivarium diet. Matings to provide the first generation were between one parent fed the special diet and a partner fed standard diet. With an adequate number of implants examined on day 16 of gestation, embryonic death rate was not found to be increased; hence, induction of dominant lethality from consumption of irradiated diet failed to be demonstrated

  19. Biosensor cell assay for measuring real-time aldosterone-induced release of histamine from mesenteric arteries

    DEFF Research Database (Denmark)

    Dalgaard, Emil G; Andersen, Kenneth; Svenningsen, Per

    2017-01-01

    as a sensitive biosensor assay for histamine release from isolated mouse mesenteric arteries. Activation of the H1 receptor by histamine was measured as an increased number of intracellular Ca(2+) transient peaks using fluorescence imaging RESULTS: The developed biosensor was sensitive to histamine...... in physiological relevant concentrations and responded to substances released by the artery preparation. Aldosterone treatment of mesenteric arteries from wild type mice for 50 minutes resulted in an increased number of intracellular Ca(2+) transient peaks in the biosensor cells, which was significantly inhibited...... by the histamine H1 blocker pyrilamine. Mesenteric arteries from mast cell deficient SASH mice induced similar pyrilamine-sensitive Ca(2+) transient response in the biosensor cells. Mesenteric arteries from wild type and SASH mice expressed histamine decarboxylase mRNA, indicating that mast cells are not the only...

  20. A state-of-the-art passive gamma-ray assay system

    International Nuclear Information System (INIS)

    Sampson, T.E.; Parker, J.L.; Cowder, L.R.; Kern, E.A.; Garcia, D.L.; Ensslin, N.

    1987-01-01

    We report details of the development of a high-accuracy, high-precision system for the non-destructive assay of 235 U in solution. The system can measure samples with concentrations ranging from 0.0001 to 500 g 235 U/l using 200-ml samples at low concentrations, 30-ml samples at high concentrations, and 1000-s measurement times. The accuracy and precision goals of 0.1% were essentially attained for concentrations above 100 g/l. This at-line system, designed for a production plant environment, represents a significant improvement in the state of the art

  1. Q2 - a very low level quantitative and qualitative waste assay and release certification system

    International Nuclear Information System (INIS)

    Bronson, F.L.

    1990-01-01

    Low level radioactive waste disposal is very expensive, especially when all of the handling transportation and documentation costs are included. However for most generators, a large fraction of this low level waste is not contaminated at all, or only slightly so. The paper describes the development and performance of a low level counter that is convenient to use, and that can accurately identify and quantify the radioactivity of any gamma emitter thing that can be placed in a 55 gallon (200 liter) container. These measurement results can be used to verify the absence of radioactivity at a very low levels (10 nCi (370 Bq)/sample), and to identify the nuclides and quantities present, while differentiating against natural radioactivity (Radium, Thorium, Potassium). These results can be used as part of a 10CFR20.302 waste stream exemption program, and thus allow significant savings and a less than 1 year payback at a typical nuclear power plant. The Q1 system is fully shielded to allow it's use in the low level radwaste storage area. The detectors are either 3 Intrinsic Germanium detectors or 2 large NaI detectors. The software is fully automated for simple operation. Correlation factors can be entered to estimate non-gamma emitters from pre-established correlations to other nuclides. Typical Ge detector sensitivities are 8 nCi (300 Bq) LLD for Cs-137 at 0.8 g/cc for a 10 minute count time. NaI detector systems can achieve the same LLD in a 1 minute count. 5 figs., 1 tab

  2. In-Vitro Release of Ketoprofen Behavior Loaded in Polyvinyl Alcohol / Acrylamide Hydrogels Prepared by Gamma Irradiation

    International Nuclear Information System (INIS)

    Mahmoud, Gh.A.; Hegazy, D.E.; Kamal, H.

    2014-01-01

    Hydrogels based on various ratios of polyvinyl alcohol (PVA) and acrylamide (AAm) were prepared by gamma radiation. The formed hydrogels were characterized by spectroscopic analysis (FTIR), differential scanning calorimetry (DSC), thermogravimetric analysis (TGA) and swelling studied. It was found that the thermal stability of the hydrogel decreases as the AAm content increases in the hydrogel. The higher the AAm content in the hydrogel, the lower the values of Tm and ΔH m . Ketoprofen was adopted as a model drug to study the adsorption and release behavior of (PVA/AAm) hydrogel. The drug adsorption was decreased by increasing AAm ratio in the hydrogel. From the in vitro drug release study in ph progressive media, the basic medium was showed comparatively the highest release and the (PVA/AAm) hydrogel of composition (70/30) was found to be the highest release one. The mechanism of Ketoprofen release from the (PVA/AAm) matrix was found to be non-Fickian mechanism for all investigated hydrogels at ph 7.

  3. Gamma-amino butyric acid (GABA) release in the ciliated protozoon Paramecium occurs by neuronal-like exocytosis.

    Science.gov (United States)

    Ramoino, P; Milanese, M; Candiani, S; Diaspro, A; Fato, M; Usai, C; Bonanno, G

    2010-04-01

    Paramecium primaurelia expresses a significant amount of gamma-amino butyric acid (GABA). Paramecia possess both glutamate decarboxylase (GAD)-like and vesicular GABA transporter (vGAT)-like proteins, indicating the ability to synthesize GABA from glutamate and to transport GABA into vesicles. Using antibodies raised against mammalian GAD and vGAT, bands with an apparent molecular weight of about 67 kDa and 57 kDa were detected. The presence of these bands indicated a similarity between the proteins in Paramecium and in mammals. VAMP, syntaxin and SNAP, putative proteins of the release machinery that form the so-called SNARE complex, are present in Paramecium. Most VAMP, syntaxin and SNAP fluorescence is localized in spots that vary in size and density and are primarily distributed near the plasma membrane. Antibodies raised against mammal VAMP-3, sintaxin-1 or SNAP-25 revealed protein immunoblot bands having molecular weights consistent with those observed in mammals. Moreover, P. primaurelia spontaneously releases GABA into the environment, and this neurotransmitter release significantly increases after membrane depolarization. The depolarization-induced GABA release was strongly reduced not only in the absence of extracellular Ca(2+) but also by pre-incubation with bafilomycin A1 or with botulinum toxin C1 serotype. It can be concluded that GABA occurs in Paramecium, where it is probably stored in vesicles capable of fusion with the cell membrane; accordingly, GABA can be released from Paramecium by stimulus-induced, neuronal-like exocytotic mechanisms.

  4. A high-performance liquid chromatography method for the serotonin release assay is equivalent to the radioactive method.

    Science.gov (United States)

    Sono-Koree, N K; Crist, R A; Frank, E L; Rodgers, G M; Smock, K J

    2016-02-01

    The serotonin release assay (SRA) is considered the gold standard laboratory test for heparin-induced thrombocytopenia (HIT). The historic SRA method uses platelets loaded with radiolabeled serotonin to evaluate platelet activation by HIT immune complexes. However, a nonradioactive method is desirable. We report the performance characteristics of a high-performance liquid chromatography (HPLC) SRA method. We validated the performance characteristics of an HPLC-SRA method, including correlation with a reference laboratory using the radioactive method. Serotonin released from reagent platelets was quantified by HPLC using fluorescent detection. Results were expressed as % release and classified as positive, negative, or indeterminate based on previously published cutoffs. Serum samples from 250 subjects with suspected HIT were tested in the HPLC-SRA and with the radioactive method. Concordant classifications were observed in 230 samples (92%). Sera from 41 healthy individuals tested negative. Between-run imprecision studies showed standard deviation of performance characteristics, equivalent to the historic radioactive method, but avoids the complexities of working with radioactivity. © 2015 John Wiley & Sons Ltd.

  5. Standard test method for nondestructive assay of special nuclear material in low density scrap and waste by segmented passive gamma-Ray scanning

    CERN Document Server

    American Society for Testing and Materials. Philadelphia

    2010-01-01

    1.1 This test method covers the transmission-corrected nondestructive assay (NDA) of gamma-ray emitting special nuclear materials (SNMs), most commonly 235U, 239Pu, and 241Am, in low-density scrap or waste, packaged in cylindrical containers. The method can also be applied to NDA of other gamma-emitting nuclides including fission products. High-resolution gamma-ray spectroscopy is used to detect and measure the nuclides of interest and to measure and correct for gamma-ray attenuation in a series of horizontal segments (collimated gamma detector views) of the container. Corrections are also made for counting losses occasioned by signal processing limitations (1-3). 1.2 There are currently several systems in use or under development for determining the attenuation corrections for NDA of radioisotopic materials (4-8). A related technique, tomographic gamma-ray scanning (TGS), is not included in this test method (9, 10, 11). 1.2.1 This test method will cover two implementations of the Segmented Gamma Scanning ...

  6. Study of gamma irradiation effects on the etching and optical properties of CR-39 solid state nuclear track detector and its application to uranium assay in soil samples

    International Nuclear Information System (INIS)

    Amol Mhatre; Kalsi, P.C.

    2011-01-01

    The gamma irradiation effects in the dose range of 2.5-43.0 Mrad on the etching and optical characteristics of CR-39 solid state nuclear track detector (SSNTD) have been studied by using etching and UV-Visible spectroscopic techniques. From the measured bulk etch rates at different temperatures, the activation energies for bulk etching at different doses have also been determined. It is seen that the bulk etch rates increase and the activation energies for bulk etching decrease with the increase in gamma dose. The optical band gaps of the unirradiated and the gamma -irradiated detectors determined from the UV-Visible spectra were found to decrease with the increase in gamma dose. These results have been explained on the basis of scission of the detector due to gamma irradiation. The present studies can be used for the estimation of gamma dose in the range of 2.5-43.0 Mrad and can also be used for estimating track registration efficiency in the presence of gamma dose. The CR-39 detector has also been applied for the assay of uranium in some soil samples of Jammu city. (author)

  7. Identifying Predictors of Interferon-γ Release Assay Results in Pediatric Latent Tuberculosis: A Protective Role of Bacillus Calmette-Guérin?

    Science.gov (United States)

    Sotgiu, Giovanni; Altet-Gómez, Neus; Tsolia, Maria; Ruga, Ezia; Velizarova, Svetlana; Kampmann, Beate

    2012-01-01

    Rationale: Interferon-γ (IFN-γ) release assays are widely used to diagnose latent infection with Mycobacterium tuberculosis in adults, but their performance in children remains incompletely evaluated to date. Objectives: To investigate factors influencing results of IFN-γ release assays in children using a large European data set. Methods: The Pediatric Tuberculosis Network European Trials group pooled and analyzed data from five sites across Europe comprising 1,128 children who were all investigated for latent tuberculosis infection by tuberculin skin test and at least one IFN-γ release assay. Multivariate analyses examined age, bacillus Calmette-Guérin (BCG) vaccination status, and sex as predictor variables of results. Subgroup analyses included children who were household contacts. Measurements and Main Results: A total of 1,093 children had a QuantiFERON-TB Gold In-Tube assay and 382 had a T-SPOT.TB IFN-γ release assay. Age was positively correlated with a positive blood result (QuantiFERON-TB Gold In-Tube: odds ratio [OR], 1.08 per year increasing age [P 5 yr). Conclusions: Our data show that BCG vaccination may be effective in protecting children against Mycobacterium tuberculosis infection. To restrict use of IFN-γ release assays to children with positive skin tests risks underestimating latent infection. PMID:22700862

  8. Differences in immunoglobulin subclasses between dye exclusion and 51Cr release complement-dependent lymphocytotoxicity assays

    International Nuclear Information System (INIS)

    McConnachie, P.R.; Denegri, J.F.; Lower, F.E.; Torry, D.S.; McIntyre, J.A.

    1986-01-01

    Paradoxical differences previously noted between lymphocytotoxicity detected by dye exclusion at room temperature (CDCE) or by 51 Cr release (CDC 51 Cr) at 37 0 C in maternal antipaternal complement-dependent lymphocytotoxicity have suggested that CDCE and CDC 51 Cr at 37 0 C, but not at 20 degrees C, may detect different immunological antibody-antigen interactions. Reactions in the two test systems against the same target cells were compared in sera from known immune dialysis patients, secondary aborting women, and refractory platelet recipients before and after heat treatment of sera, absorption with solid-phase heparin, anti-light-chain augmentation, and the addition of murine monoclonal anti-IgG subclass antibodies. The results demonstrate significant differences between the two tests using the same target and sera. Further, the results imply the presence of an inhibitor and an inhibitor of inhibitor in sera. The involvement of different immunoglobulin subclasses was shown in the two tests. These data demonstrate the necessity for further study of the nature of the differences in the mechanisms of these clinically important antibody-detecting systems

  9. The effect of gamma radiation on the Common carp (Cyprinus carpio): In vivo genotoxicity assessment with the micronucleus and comet assays.

    Science.gov (United States)

    M K, Praveen Kumar; Soorambail K, Shyama; Bhagatsingh Harisingh, Sonaye; D'costa, Avelyno; Ramesh Chandra, Chaubey

    2015-10-01

    Radioactive wastes may be leached into freshwater, either accidentally or in industrial effluents. We have studied gamma radiation-induced DNA damage in the freshwater fish Cyprinus carpio. Fish were irradiated with 2-10Gy gamma radiation and genotoxic effects in blood cells were studied with the micronucleus (MN) and comet assays. Micronuclei and a dose-dependent increase in comet-tail DNA were seen in dose- and time-dependent studies. The highest % tail DNA was observed at 24h, declining until 72h, which may indicate the repair of radiation-induced DNA single-strand breaks after gamma radiation. However, double-stranded DNA damage may not have been repaired, as indicated by increased micronuclei at later periods. A positive correlation was observed between the comet and micronucleus assay results. This study confirms the mutagenic/genotoxic potential of gamma radiation in the Common carp, as well as the possible combined use of the micronucleus and comet assays for in vivo laboratory studies with fresh-water fish for screening the genotoxic potential of radioactive pollution. Copyright © 2015 Elsevier B.V. All rights reserved.

  10. VARIATION IN RHIZOBIUM GROWTH DUE TO SEED AND ROOT EXUDATES RELEASED FROM GAMMA IRRADIATED GLYCINE MAX SEEDS

    International Nuclear Information System (INIS)

    KAMEL, H.A.; ASKER, M.M.S

    2008-01-01

    In this study, seeds of Glycine max Giza 122 were irradiated with gamma rays from 60 Co source at various doses (10 to 200 Gy), sterilized and soaked into an aerated solution of CaSO 4 (1 mmol and pH 6.5). The capacities of the released seed exudates (SEs) and root exudates (REs) to promote Rhizobium leguminosarum growth were investigated as well as biochemical analysis of the exudates was carried out. SE of both control and gamma irradiated seeds resulted in a higher Rhizobium population and polysaccharide production than RE. Relative to control, the highly effective doses in Rhizobium growth and polysaccharide production were 25 and 200 Gy; the former was a promoter while the later was an inhibitor. HPLC analysis of soluble carbohydrates revealed the presence of glucose (Glu), rhamnose (Rha) and fructose (Fru) in the SE and RE. Protein content in SE was lower than that in RE; the highest values were due to 10 Gy and 25 Gy in SE and RE, respectively. Free amino acids content in SE was increased up to 25 Gy then decreased while RE was increased by increasing gamma doses from 10 to 200 Gy

  11. Direct measurement of human plasma corticotropin-releasing hormone by two-site immunoradiometric assay

    International Nuclear Information System (INIS)

    Linton, E.A.; McLean, C.; Nieuwenhuyzen Kruseman, A.C.; Tilders, F.J.; Van der Veen, E.A.; Lowry, P.J.

    1987-01-01

    A ''two-site'' immunoradiometric assay (IRMA) which allows the direct estimation of human CRH (hCRH) in plasma is described. Using this IRMA, basal levels of CRH in normal subjects ranged from 2-28 pg/mL [mean, 15 +/- 7 (+/- SD) pg/mL; n = 58]. Values in men and women were similar. Plasma CRH values within this range were also found in patients with Cushing's syndrome, Addison's disease, and Nelson's syndrome, with no correlation between plasma CRH and ACTH levels in these patients. Elevated plasma CRH levels were found in pregnant women near term [1462 +/- 752 (+/- SD) pg/mL; n = 55], and the dilution curve of this CRH-like immunoreactivity paralleled the IRMA standard curve. After its immunoadsorption from maternal plasma, this CRH-like material eluted on reverse phase high performance liquid chromatography with a retention time identical to that of synthetic CRH and had equipotent bioactivity with the synthetic peptide in the perfused anterior pituitary cell bioassay. Circulating CRH was not detected in Wistar rats, even after adrenalectomy and subsequent ether stress. Synthetic hCRH was degraded by fresh human plasma relatively slowly; 65% of added CRH remained after 1 h of incubation at 37 C. Degradation was inhibited by heat treatment (54 C; 1 h), cold treatment (4 C; 4 h), or freezing and thawing. Loss of synthetic rat CRH occurred more rapidly when fresh rat plasma was used; only 20% of added CRH remained under the same conditions. The inability to measure CRH in peripheral rat plasma may be due to the presence of active CRH-degrading enzymes which fragment the CRH molecule into forms not recognized by the CRH IRMA

  12. Comparison of DNA comet assay and germination test (half-embryo-test) in gamma-irradiated cherry seeds

    International Nuclear Information System (INIS)

    Todoroki, Setsuko; Hayashi, Toru

    2002-01-01

    Cherry fruits were irradiated with gamma-rays at doses up to 200Gy (effective dose for disinfestation of codling moth), and DNA strand break in seed embryos was investigated by using alkaline comet assay. Immediately after irradiation (≥100Gy), DNA from embryos produced comets with a long and wide tail due to fragmentation. In control cells, DNA relaxed and produced comet with very short tail (with few strand break). After 72h storage, DNA from fruits irradiated at 200 Gy showed comets with little tail and tail moment of comets was same as un-irradiated control. These results indicate that the strand breaks of DNA caused by irradiation in fresh seed embryo are repaired during storage. On the contrary, the ability of germination lost by irradiation did not restored, a dose of 100Gy and more retarded shoot elongation. In cherries irradiated at 100Gy, the shooting percentage was less than 50% at 4th day after incubation. Germination test (Half embryo test) can be discriminate between irradiated and un-irradiated cherries. (author)

  13. Control of drug releasing from biodegradable polymer drug delivery system by gamma-ray irradiation

    International Nuclear Information System (INIS)

    Yoshioka, Sumie; Aso, Yukio; Kojima, Shigeo

    1999-01-01

    In order to introduce the drug to the target organ, we developed a gel to control the drug releasing velocity by response to change of temperature by means of γ-ray irradiation to gelatin-GMA modified dextran mixture aqueous solution. A certain level of molecular weight of drug is necessary. The response to the temperature (change of drug releasing velocity) was affected by the concentration of gelatin and the modification rate of GMA. The Higuchi equation was applied to the releasing of β-galactosidase from gelatin-dextran gel and the releasing velocity was calculated. The releasing velocity decreased with increasing GMA modification rate at 37degC and 15degC. The releasing velocity of β-galactosidase decreased with increasing the concentration of gelatin at 15degC, but the velocity increased with increasing the concentration at 37degC. These results indicated that the good drug releasing conditions are obtained by controlling the GMA modification rate and the concentration of gelatin. (S.Y.)

  14. Comparison of two insulin assays for first-phase insulin release in type 1 diabetes prediction and prevention studies.

    Science.gov (United States)

    Mahon, Jeffrey L; Beam, Craig A; Marcovina, Santica M; Boulware, David C; Palmer, Jerry P; Winter, William E; Skyler, Jay S; Krischer, Jeffrey P

    2011-11-20

    Detection of below-threshold first-phase insulin release or FPIR (1+3 minute insulin concentrations during an intravenous glucose tolerance test [IVGTT]) is important in type 1 diabetes prediction and prevention studies including the TrialNet Oral Insulin Prevention Trial. We assessed whether an insulin immunoenzymometric assay (IEMA) could replace the less practical but current standard of a radioimmunoassay (RIA) for FPIR. One hundred thirty-three islet autoantibody positive relatives of persons with type 1 diabetes underwent 161 IVGTTs. Insulin concentrations were measured by both assays in 1056 paired samples. A rule classifying FPIR (below-threshold, above-threshold, uncertain) by the IEMA was derived and validated against FPIR by the RIA. The insulin IEMA-based rule accurately classified below- and above-threshold FPIRs by the RIA in 110/161 (68%) IVGTTs, but was uncertain in 51/161 (32%) tests for which FPIR by RIA is needed. An uncertain FPIR by the IEMA was more likely among below-threshold vs above-threshold FPIRs by the RIA (64% [30/47] vs. 18% [21/114], respectively; pTrialNet is limiting the insulin RIA for FPIR to the latter given the practical advantages of the more specific IEMA. Copyright © 2011 Elsevier B.V. All rights reserved.

  15. Effects of peritoneal fluid from endometriosis patients on interferon-gamma-induced protein-10 (CXCL10) and interleukin-8 (CXCL8) released by neutrophils and CD4+ T cells.

    Science.gov (United States)

    Kim, Ji-Yeon; Lee, Dong-Hyung; Joo, Jong-Kil; Jin, Jun-O; Wang, Ji-Won; Hong, Young-Seoub; Kwak, Jong-Young; Lee, Kyu-Sup

    2009-09-01

    Intraperitoneal immuno-inflammatory changes may be associated with the pathogenesis of endometriosis. We evaluated the effects of peritoneal fluid obtained from patients with endometriosis (ePF) on the release of interferon-gamma-induced protein-10 (IP-10/CXCL10) and interleukin-8 (IL-8/CXCL8) by neutrophils, CD4(+) T cells, and monocytes. Neutrophils, CD4(+) T cells, and monocytes were cultured with ePF and the chemokine levels in the supernatants were then measured using enzyme-linked immunosorbent assay. The addition of ePF to cultures of CD4(+) T cells led to a significant increase in the release of IP-10 when compared with control PF without endometriosis (cPF). There was a positive correlation between the levels of IL-8 and IP-10 in ePF (R = 0.89, P = 0.041), but not between the levels of IP-10 and IL-8 released by neutrophils, CD4(+) T cells, and monocytes. The levels of IP-10 in ePF were positively correlated with the release of IP-10 by ePF-treated neutrophils (R = 0.89, P ePF significantly enhanced the interferon-gamma-induced release of IP-10 by nuetrophils and CD4(+) T cells. These findings suggest that neutrophils and T cells release differential levels of IP-10 and IL-8 in response to stimulation with ePF, and that these cells are a major source of IP-10 in the PF of endometriosis patients.

  16. Comparative study of gamma-ray logging and radiometric core assay of boreholes in block-I of Tummalapalle area, Cuddapah District, Andhra Pradesh using statistical methods

    International Nuclear Information System (INIS)

    Sreenivasa Reddy, M.; Mandal, G.; Bhaumik, B.K.

    2012-01-01

    A comparative study has been carried out between gamma-ray logging and radiometric core assay data of boreholes in Block-I of Tummalapalle area, South Cuddapah Basin, Andhra Pradesh using statistical methods. The product of average grade (in %eU 3 O 8 ) and thickness (in m) of uranium mineralization has been used for this purpose. The outcome of statistical analysis revealed a strong relation between gamma-ray logging and radiometric core assay data. Slope of the line is close to 1.0 and intercept is not different from 0.0. It ensures homogeneity of uranium ore distribution in the host rock. The calculated value from t-test is well within the limit and ensures the negligibility in the difference of means. This indicates that either of the data can be used for ore reserve calculation. (author)

  17. The effect of food on gastrointestinal (GI) transit of sustained-release ibuprofen tablets as evaluated by gamma scintigraphy

    International Nuclear Information System (INIS)

    Borin, M.T.; Khare, S.; Beihn, R.M.; Jay, M.

    1990-01-01

    The GI transit of radiolabeled sustained-release ibuprofen 800-mg tablets in eight healthy, fed volunteers was monitored using external gamma scintigraphy. Ibuprofen serum concentrations were determined from blood samples drawn over 36 hr following dosing. Sustained-release ibuprofen tablets containing 0.18% of 170Er2O3 (greater than 96% 170Er) in the bulk formulation were manufactured under pilot-scale conditions and were radiolabeled utilizing a neutron activation procedure which converted stable 170Er to radioactive 171Er (t1/2 = 7.5 hr). At the time of dosing, each tablet contained 50 mu Ci of 171Er. Dosage form position were reported at various time intervals. In five subjects the sustained-release tablet remained in the stomach and eroded slowly over 7-12 hr, resulting in gradual increases in small bowel radioactivity. In the remaining three subjects, the intact tablet was ejected from the stomach and a gastric residence time of approximately 4 hr was measured. This is in marked contrast to a previous study conducted in fasted volunteers in which gastric retention time ranged from 10 to 60 min. Differences in GI transit between fed and fasted volunteers had little effect on ibuprofen bioavailability. AUC and Tmax were unaltered and Cmax was increased by 24%, which is in agreement with results from a previous, crossover-design food effect study

  18. Neutron and gamma-ray nondestructive examination of contact-handled transuranic waste at the ORNL TRU Waste Drum Assay Facility

    International Nuclear Information System (INIS)

    Schultz, F.J.; Coffey, D.E.; Norris, L.B.; Haff, K.W.

    1985-03-01

    A nondestructive assay system, which includes the Neutron Assay System (NAS) and the Segmented Gamma Scanner (SGS), for the quantification of contact-handled (<200 mrem/h total radiation dose rate at contact with container) transuranic elements (CH-TRU) in bulk solid waste contained in 208-L and 114-L drums has been in operation at the Oak Ridge National Laboratory since April 1982. The NAS has been developed and demonstrated by Los Alamos National Laboratory (LANL) and the Oak Ridge National Laboratory (ORNL) for use by most US Department of Energy Defense Plant (DOE-DP) sites. More research and development is required, however, before the NAS can provide complete assay results for other than routine defense waste. To date, 525 ORNL waste drums have been assayed, with varying degrees of success. The isotopic complexity of the ORNL waste creates a correspondingly complex assay problem. The NAS and SGS assay data are presented and discussed. Neutron matrix effects, the destructive examination facility, and enriched uranium fuel-element assays are also discussed

  19. Interferon gamma, interferon-gamma-induced-protein 10, and tuberculin responses of children at high risk of tuberculosis infection

    DEFF Research Database (Denmark)

    Petrucci, Roberta; Abu Amer, Nabil; Gurgel, Ricardo Queiroz

    2008-01-01

    BACKGROUND: Children in contact with adults with pulmonary tuberculosis (TB) are at risk for infection and disease progression, and chemoprophylaxis may reduce this risk. The identification of infection is based on the tuberculin skin test (TST) and interferon-gamma (INF-gamma) release assays. Ot...

  20. Interferon gamma, interferon-gamma-induced-protein 10, and tuberculin responses of children at high risk of tuberculosis infection

    DEFF Research Database (Denmark)

    Petrucci, Roberta; Abu Amer, Nabil; Gurgel, Ricardo Queiroz

    2008-01-01

    BACKGROUND: Children in contact with adults with pulmonary tuberculosis (TB) are at risk for infection and disease progression, and chemoprophylaxis may reduce this risk. The identification of infection is based on the tuberculin skin test (TST) and interferon-gamma (INF-gamma) release assays...

  1. IFN-γ release assay conversions and reversions. Challenges with serial testing in U.S. health care workers.

    Science.gov (United States)

    Joshi, Manish; Monson, Thomas P; Joshi, Anita; Woods, Gail L

    2014-03-01

    IFN-γ release assays (IGRAs) including the QuantiFERON-TB gold in-tube test (QFT-GIT) are increasingly used in place of the tuberculin skin test (TST) in surveillance programs for Mycobacterium tuberculosis infection in the United States. However, data on conversions, reversions, and predictive value of QFT in such programs for health care workers (HCWs) are limited. The purpose of this study is to assess long-term reproducibility and conversion and reversion rates of QFT-GIT among HCWs who underwent serial testing at a tertiary care center in the United States. Retrospective chart review of HCWs at the Central Arkansas Veterans Healthcare System (CAVHS) who underwent serial testing with QFT-GIT as a part of their employee screening between November 1, 2008 and January 31, 2011. A total of 2,303 HCWs had at least 2 QFT-GITs 1 year apart. The initial QFT-GIT was positive for 69 and 2 were indeterminate. Of these 69 HCWs, 31 (45%) reverted on repeat testing, and 25 of 31 (80.6%) HCWs who reverted had a negative look-back TST. Of the 2,232 HCWs with an initial negative QFT-GIT, 71 (3.2%) converted on repeat testing. A third QFT-GIT assay was performed in 41 of the 71 converters and 90% (37 of 41) reverted back to negative. Only two HCWs had TST and QFT-GIT conversion. Poor IGRA reproducibility and a low predictive value of QFT-GIT conversions indicate that QFT-GIT with current interpretation criteria should not be used for serial screening of U.S. HCWs. Negative TSTs have higher reproducibility than QFT-GIT for serial testing of HCWs in low tuberculosis incidence settings.

  2. Release of a new lodging-resistant mutant cultivar produced by gamma-rays in glutinous rice

    International Nuclear Information System (INIS)

    Yamaguchi, Hikoyuki; Igarashi, Isao; Sato, Takeshi

    2001-01-01

    To obtain short culm mutants with lodging resistance, while retaining the other desirable traits, such as an excellent quality of the original variety, dry seeds of a glutinous rice cultivar Mezuru were exposed to gamma-rays. In M3, thirty plants were selected from 4020 plants, based on the short culm length. From the results of the subsequent yield and adaptability tests, a promising mutant line was called by the name of Sakata-Mezuru as a new cultivar in 1996. This mutant variety was mainly characterized by shortening of each internode, especially the lowest internode, and at harvest it was more adaptable to mechanical work due to the lodging resistance than its parent. It was demonstrated that the grain quality of the mutant equals to or slightly surpasses that of the parent. Sakata-Mezuru has been registered in February of 2001 and officially released. (author)

  3. Changes in pheromone production, release, mating behaviour and reproductive ability of the gamma-irradiated cockroach Nauphoeta cinerea (Olivier)

    International Nuclear Information System (INIS)

    Menon, M.

    1978-01-01

    Mature males of Nauphoeta cinerea produce a sex pheromone 'seducin' which has short-range effects in attracting mature females of the same species. Exposure of newly-emerged adult males to 3.5, 7, 14 or 21 krad of gamma-radiation decreased their life expectancy and affected their mating behaviour. Bioassay of dichloromethane extracts of males showed that radiation doses (14 krad) sufficient to induce sterility did not affect the ability to produce pheromone but significantly reduced the release of pheromone by inhibiting wing-raising. The sterile-male technique using males sterilized by ionizing radiation in air may not be the method of choice for control of Nauphoeta cinerea. (author)

  4. Release of bound residues of atrazine from soils through autoclaving and gamma radiation sterilization

    International Nuclear Information System (INIS)

    Nakagawa, L.E.; Andréa, M.M.

    1997-01-01

    The sterilization methods are particularly important to study the influence of microorganisms on the pesticide dissipation in soils. This study, conducted in the laboratories of the Instituto Biológico of São Paulo in august 1996, tested the influence of two methods of soil sterilization - moist heat (autoclaving) and γ radiation - on the release of nonextractable or bound residues. It was studied, as example, bound residues of the herbicide atrazine in two types of soil (gley humic and dark red latosol). In the soil samples submitted to the moist heat sterilization, the recovery of the previously bound residues as reextractable residues was 5.6 and 5.9 times higher than in the control soils, not submitted to any sterilization process. Therefore, the method itself released the residues, indicating that the autoclaving is not the most appropriate method for studies on the influence of microorganisms on the release of bound residues. Otherwise, the γ radiation did not modify the residues recovery when compared to the controls. (author) [pt

  5. Cytokine Release Assays as Tests for Exposure to Leishmania, and for Confirming Cure from Leishmaniasis, in Solid Organ Transplant Recipients.

    Directory of Open Access Journals (Sweden)

    Eugenia Carrillo

    Full Text Available Spain has one of the world's largest pools of organ donors and is a global leader in terms of the number of transplants it performs. The current outbreak of leishmaniasis in Fuenlabrada (in the southwest of the region of Madrid, Spain has involved 600 clinical cases since late 2009 (prevalence 0.2%. It may therefore be wise to monitor the town's transplanted population for Leishmania infantum; its members are immunosuppressed and at greater risk of infection and relapse following treatment. The present work examines the use of cytokine release assays to determine the prevalence of Leishmania infection in this population, and to confirm recovery following treatment for visceral leishmaniasis (VL. The humoral and cellular immune responses to L. infantum were characterized in 63 solid organ transplant (SOT recipients from Fuenlabrada, 57 of whom reported no previous episode of VL (NVL subjects, and six of whom had been cured of VL (CVL subjects. Seventeen subjects (12 NVL and 5 CVL showed a patent lymphoproliferative response to soluble Leishmania antigen (SLA. Stimulation of peripheral blood mononuclear cell cultures and of whole blood with SLA led to the production of different combinations of cytokines that might serve to confirm Leishmania infection or recovery from VL and help prevent cured patients from relapsing into this serious condition.

  6. Clinical evaluation of thyrotropin-releasing hormone (TRH) test with a sensitive immunoradiometric thyrotropin (TSH) assay kit

    International Nuclear Information System (INIS)

    Nakamura, Saeko; Demura, Reiko; Yamanaka, Yukako; Ishiwatari, Naoko; Jibiki, Kazuko; Odagiri, Emi; Demura, Hiroshi

    1987-01-01

    Thyrotropin-releasing hormone (TRH) test was performed using a commercially available immunoradiometric thyrotropin (TSH) assay kit (RIA-gnost hTSH) in patients with endocrine diseases. The basal serum concentration of TSH ranged from 0.2 to 2.9 μU/ml in healthy subjects. The values for endocrine diseases, except for Graves' disease, were almost within the normal range. A significant increase in TSH values caused by TRH test was observed in females compared with males (4.4 - 24.7 μU/ml vs 4.1 - 12.3 μU/ml). In cases of Graves' disease, there was a good correlation between the basal TSH value and the response of TSH to TRH. However, in the other endocrine diseases, including acromegaly, prolactinoma, anorexia nervosa, Cushing syndrome, and hypopituitarism, the response of TSH to TRH did not necessarily correlated with the basal TSH value. TRH test would be of value in elucidating pathophysiologic features, as well as in accurately diagnosing secretion reserve of TSH. (Namekawa, K.)

  7. Clinical evaluation of thyrotropin-releasing hormone (TRH) test with a sensitive immunoradiometric thyrotropin (TSH) assay kit

    Energy Technology Data Exchange (ETDEWEB)

    Nakamura, Saeko; Demura, Reiko; Yamanaka, Yukako; Ishiwatari, Naoko; Jibiki, Kazuko; Odagiri, Emi; Demura, Hiroshi

    1987-10-01

    Thyrotropin-releasing hormone (TRH) test was performed using a commercially available immunoradiometric thyrotropin (TSH) assay kit (RIA-gnost hTSH) in patients with endocrine diseases. The basal serum concentration of TSH ranged from 0.2 to 2.9 ..mu..U/ml in healthy subjects. The values for endocrine diseases, except for Graves' disease, were almost within the normal range. A significant increase in TSH values caused by TRH test was observed in females compared with males (4.4 - 24.7 ..mu..U/ml vs 4.1 - 12.3 ..mu..U/ml). In cases of Graves' disease, there was a good correlation between the basal TSH value and the response of TSH to TRH. However, in the other endocrine diseases, including acromegaly, prolactinoma, anorexia nervosa, Cushing syndrome, and hypopituitarism, the response of TSH to TRH did not necessarily correlated with the basal TSH value. TRH test would be of value in elucidating pathophysiologic features, as well as in accurately diagnosing secretion reserve of TSH. (Namekawa, K.).

  8. Cost-effectiveness of interferon-γ release assay versus chest X-ray for tuberculosis screening of employees.

    Science.gov (United States)

    Kowada, Akiko

    2011-12-01

    Currently, an annual chest X-ray examination (CXR) for detection of active tuberculosis (TB) in employees aged ≥40 years is recommended in the guidelines of the Japan Industrial Safety and Health Law. Interferon-γ release assays are new alternatives to the tuberculin skin test for detecting Mycobacterium tuberculosis infection, with higher specificity than the tuberculin skin test and without cross-reactivity with the Bacille Calmette-Guérin vaccine. This study aimed to assess the cost-effectiveness of employee TB screening using QuantiFERON-TB Gold In-Tube (QFT) versus CXR. Markov models were constructed. The target population was a hypothetical cohort of immunocompetent 40-year-old individuals, using a societal perspective and a lifetime horizon. All costs and clinical benefits were discounted at a fixed annual rate of 3%. In a base-case analysis, the QFT strategy was the most cost-effective ($US 262.84; 22.87049 quality-adjusted life-years [QALYs]) compared with no screening ($448.38; 22.85452 QALYs) and CXR ($543.50; 22.85453 QALYs) [year 2009 values]. The QFT strategy is currently robust for screening Bacille Calmette-Guérin- vaccinated employees in Japan. There appears to be little role for CXR. These findings may be applicable to other countries in terms of choosing optimal TB screening for employees. Copyright © 2011 Association for Professionals in Infection Control and Epidemiology, Inc. Published by Mosby, Inc. All rights reserved.

  9. Inhibition of clone formation as an assay for T cell-mediated cytotoxicity: short-term kinetics and comparison with 51Cr release

    International Nuclear Information System (INIS)

    Lees, R.K.; MacDonald, H.R.; Sinclair, N.R.; University of Western Ontario London

    1977-01-01

    The short-term kinetics of T cell-mediated cytotoxicity was investigated using a cloning inhibition assay. Murine cytotoxic thymus-derived lymphocytes generated in vitro in mixed leukocyte cultures were incubated for various periods of time at 37degC with allogeneic mastocytoma target cells. The mixtures were then plated in soft agar, and mastocytoma clone formation was assessed after 5-7 days incubation. Using this technique, it was demonstrated that events leading to the loss of cloning ability could be detected after 1-3 min incubation at 37degC, and after 20-30 min, 95% of the clone forming cells had been inactivated. When these results were compared directly with those obtained using the conventional 51 Cr-release assay, it was found that the events leading to loss of cloning ability occurred more rapidly than indicated by the isotope assay. However, a modification of the 51 Cr-release assay involving EDTA addition gave comparable result to the cloning inhibition assay. These results raise the possibility that the events leading to 51 Cr-release of tumor target cells may be related in time to those leading to the loss of cloning ability

  10. Evaluation through comet assay of DNA damage induced in human lymphocytes by alpha particles. Comparison with protons and Co-60 gamma rays

    International Nuclear Information System (INIS)

    Di Giorgio, M.; Kreiner, A. J.; Schuff, J. A.; Vallerga, M. B.; Taja, M. R.; Lopez, F. O.; Alvarez, D. E.; Saint Martin, G.; Burton, A.; Debray, M. E.; Kesque, J. M.; Somacal, H.; Stoliar, P.; Valda, A.; Davidson, J.; Davidson, M.; Ozafran, M. J.; Vazquez, M. E.

    2004-01-01

    Several techniques with different sensitivity to single-strand breaks and/or double strand breaks were applied to detect DNA breaks generated by high LET particles. Tests that assess DNA damage in single cells might be the appropriate tool to estimate damage induced by particles, facilitating the assessment of heterogeneity of damage in a cell population. The microgel electrophoresis (comet) assay is a sensitive method for measuring DNA damage in single cells. The objective of this work was to evaluate the proficiency of comet assay to assess the effect of high LET radiation on peripheral blood lymphocytes, compared to protons and Co-60 gamma rays. Materials and methods: Irradiations of blood samples were performed at TANDAR laboratory (Argentina). Thin samples of human peripheral blood were irradiated with different doses (0-2.5 Gy) of 20.2 MeV helium-4 particles in the track segment mode, at nearly constant LET. Data obtained were compared with the effect induced by a MeV protons and Co-60 gamma rays. Alkaline comet assay was applied. Comets were quantified by the Olive tail moment. Distribution of the helium-4 particle and protons were evaluated considering Poisson distribution in lymphocyte nuclei. The mean dose per nucleus per particle result 0.053 Gy for protons and 0.178 Gy for helium-4 particles. When cells are exposed to a dose of 0.1 Gy, the hit probability model predicts that 43% of the nuclei should have experienced and alpha traversal while with protons, 85% of the nuclei should be hit. The experimental results show a biphasic response for helium-4 particles (0.1 Gy), indicating the existence of two subpopulations: unhit and hit. Distributions of tail moment as a function of fluence and experimental dose for comets induced by helium-4 particles, protons and Co-60 gamma rays were analyzed. With helium-4 irradiations, lymphocyte nuclei show an Olive tail moment distribution flattened to higher tail moments a dose increase. However, for irradiations with

  11. A High Throughput Screening Assay for Anti-Mycobacterial Small Molecules Based on Adenylate Kinase Release as a Reporter of Cell Lysis.

    Directory of Open Access Journals (Sweden)

    Lauren Forbes

    Full Text Available Mycobacterium tuberculosis (Mtb is well-established to be one of the most important bacterial pathogens for which new antimicrobial therapies are needed. Herein, we describe the development of a high throughput screening assay for the identification of molecules that are bactericidal against Mycobacteria. The assay utilizes the release of the intracellular enzyme adenylate kinase into the culture medium as a reporter of mycobacterial cell death. We demonstrate that the assay is selective for mycobactericidal molecules and detects anti-mycobacterial activity at concentrations below the minimum inhibitory concentration of many molecules. Thus, the AK assay is more sensitive than traditional growth assays. We have validated the AK assay in the HTS setting using the Mtb surrogate organism M. smegmatis and libraries of FDA approved drugs as well as a commercially available Diversity set. The screen of the FDA-approved library demonstrated that the AK assay is able to identify the vast majority of drugs with known mycobactericidal activity. Importantly, our screen of the Diversity set revealed that the increased sensitivity of the AK assay increases the ability of M. smegmatis-based screens to detect molecules with relatively poor activity against M. smegmatis but good to excellent activity against Mtb.

  12. Factors associated with the performance of a blood-based interferon-γ release assay in diagnosing tuberculosis.

    Directory of Open Access Journals (Sweden)

    Sally Banfield

    Full Text Available BACKGROUND: Indeterminate results are a recognised limitation of interferon-γ release assays (IGRA in the diagnosis of latent tuberculosis (TB infection (LTBI and TB disease, especially in children. We investigated whether age and common co-morbidities were associated with IGRA performance in an unselected cohort of resettled refugees. METHODS: A retrospective cross-sectional study of refugees presenting for their post-resettlement health assessment during 2006 and 2007. Refugees were investigated for prevalent infectious diseases, including TB, and for common nutritional deficiencies and haematological abnormalities as part of standard clinical screening protocols. Tuberculosis screening was performed by IGRA; QuantiFERON-TB Gold in 2006 and QuantiFERON-TBGold In-Tube in 2007. RESULTS: Complete data were available on 1130 refugees, of whom 573 (51% were children less than 17 years and 1041 (92% were from sub-Saharan Africa. All individuals were HIV negative. A definitive IGRA result was obtained in 1004 (89% refugees, 264 (26% of which were positive; 256 (97% had LTBI and 8 (3% had TB disease. An indeterminate IGRA result was obtained in 126 (11% refugees (all failed positive mitogen control. In multivariate analysis, younger age (linear OR= 0.93 [95% CI 0.91-0.95], P<0.001, iron deficiency anaemia (2.69 [1.51-4.80], P = 0.001, malaria infection (3.04 [1.51-6.09], P = 0.002, and helminth infection (2.26 [1.48-3.46], P<0.001, but not vitamin D deficiency or insufficiency, were associated with an indeterminate IGRA result. CONCLUSIONS: Younger age and a number of common co-morbidities are significantly and independently associated with indeterminate IGRA results in resettled predominantly African refugees.

  13. Evaluation of the tuberculin skin test and the interferon-γ release assay for TB screening in French healthcare workers

    Directory of Open Access Journals (Sweden)

    Raffi Francois

    2009-11-01

    Full Text Available Abstract Introduction Using French cut-offs for the Tuberculin Skin Test (TST, results of the TST were compared with the results of an Interferon-γ Release Assay (IGRA in Healthcare Workers (HCW after contact to AFB-positive TB patients. Methods Between May 2006 and May 2007, a total of 148 HCWs of the University Hospital in Nantes, France were tested simultaneously with IGRA und TST. A TST was considered to indicate recent latent TB infection (LTBI if an increase of >10 mm or if TST ≥ 15 mm for those with no previous TST result was observed. For those with a positive TST, chest X-ray was performed and preventive chemotherapy was offered. Results All HCWs were BCG-vaccinated. The IGRA was positive in 18.9% and TST ≥ 10 mm was observed in 65.5%. A recent LTBI was believed to be highly probable in 30.4% following TST. Agreement between IGRA and TST was low (kappa 0.041. In 10 (16.7% out of 60 HCWs who needed chest X-ray following TST the IGRA was positive. In 9 (20% out of 45 HCWs to whom preventive chemotherapy was offered following TST the IGRA was positive. Of those considered TST-negative following the French guidelines, 20.5% were IGRA-positive. In a two-step strategy - positive TST verified by IGRA - 18 out of 28 (64.3% IGRA-positive HCWs would not have been detected using French guidelines for TST interpretation. Conclusion The introduction of IGRA in contact tracings of BCG-vaccinated HCWs reduces X-rays and preventive chemotherapies. Increasing the cut-off for a positive TST does not seem to be helpful to overcome the effect of BCG vaccination on TST.

  14. IFN-gamma Impairs Release of IL-8 by IL-1beta-stimulated A549 Lung Carcinoma Cells

    Directory of Open Access Journals (Sweden)

    Pfeilschifter Josef

    2008-09-01

    Full Text Available Abstract Background Production of interferon (IFN-γ is key to efficient anti-tumor immunity. The present study was set out to investigate effects of IFNγ on the release of the potent pro-angiogenic mediator IL-8 by human A549 lung carcinoma cells. Methods A549 cells were cultured and stimulated with interleukin (IL-1β alone or in combination with IFNγ. IL-8 production by these cells was analyzed with enzyme linked immuno sorbent assay (ELISA. mRNA-expression was analyzed by real-time PCR and RNase protection assay (RPA, respectively. Expression of inhibitor-κ Bα, cellular IL-8, and cyclooxygenase-2 was analyzed by Western blot analysis. Results Here we demonstrate that IFNγ efficiently reduced IL-8 secretion under the influence of IL-1β. Surprisingly, real-time PCR analysis and RPA revealed that the inhibitory effect of IFNγ on IL-8 was not associated with significant changes in mRNA levels. These observations concurred with lack of a modulatory activity of IFNγ on IL-1β-induced NF-κB activation as assessed by cellular IκB levels. Moreover, analysis of intracellular IL-8 suggests that IFNγ modulated IL-8 secretion by action on the posttranslational level. In contrast to IL-8, IL-1β-induced cyclooxygenase-2 expression and release of IL-6 were not affected by IFNγ indicating that modulation of IL-1β action by this cytokine displays specificity. Conclusion Data presented herein agree with an angiostatic role of IFNγ as seen in rodent models of solid tumors and suggest that increasing T helper type 1 (Th1-like functions in lung cancer patients e.g. by local delivery of IFNγ may mediate therapeutic benefit via mechanisms that potentially include modulation of pro-angiogenic IL-8.

  15. The release of bystander factor(s) from tissue explant cultures of rainbow trout (Onchorhynchus mykiss) after exposure to gamma radiation.

    Science.gov (United States)

    O'Dowd, Colm; Mothersill, Carmel E; Cairns, Michael T; Austin, Brian; McClean, Brendan; Lyng, Fiona M; Murphy, James E J

    2006-10-01

    The bystander response has been documented in cell lines and cell cultures derived from aquatic species over the past several years. However, little work has been undertaken to identify a similar bystander response in tissue explant cultures from fish. In this study, indirect effects of ionizing gamma radiation on tissue explant cultures of fish were investigated. Tissue explants in culture were exposed to 0.5 Gy and 5 Gy gamma radiation from a 60Co teletherapy unit. A bystander response in Epithelioma papulosum cyprini (EPC) cells exposed to gamma-irradiated tissue conditioned medium from rainbow trout explants was investigated, and the effects on cell survival were quantified by the clonogenic survival assay. Dichlorofluorescein and rhodamine 123 fluorescent dyes were used to identify alterations in reactive oxygen species (ROS) and mitochondrial membrane potential (MMP), respectively. Results indicate a different response for the three tissue types investigated. Clonogenic assay results vary from a decrease in cell survival (gill) to no effect (skin) to a stimulatory effect (spleen). Results from fluorescence assays of ROS and MMP show similarities to clonogenic assay results. This study identifies a useful model for further studies relating to the bystander effect in aquatic organisms in vivo and ex vivo.

  16. The Fukushima releases: an inverse modelling approach to assess the source term by using gamma dose rate observations

    Science.gov (United States)

    Saunier, Olivier; Mathieu, Anne; Didier, Damien; Tombette, Marilyne; Quélo, Denis; Winiarek, Victor; Bocquet, Marc

    2013-04-01

    The Chernobyl nuclear accident and more recently the Fukushima accident highlighted that the largest source of error on consequences assessment is the source term estimation including the time evolution of the release rate and its distribution between radioisotopes. Inverse modelling methods have proved to be efficient to assess the source term due to accidental situation (Gudiksen, 1989, Krysta and Bocquet, 2007, Stohl et al 2011, Winiarek et al 2012). These methods combine environmental measurements and atmospheric dispersion models. They have been recently applied to the Fukushima accident. Most existing approaches are designed to use air sampling measurements (Winiarek et al, 2012) and some of them use also deposition measurements (Stohl et al, 2012, Winiarek et al, 2013). During the Fukushima accident, such measurements are far less numerous and not as well distributed within Japan than the dose rate measurements. To efficiently document the evolution of the contamination, gamma dose rate measurements were numerous, well distributed within Japan and they offered a high temporal frequency. However, dose rate data are not as easy to use as air sampling measurements and until now they were not used in inverse modelling approach. Indeed, dose rate data results from all the gamma emitters present in the ground and in the atmosphere in the vicinity of the receptor. They do not allow one to determine the isotopic composition or to distinguish the plume contribution from wet deposition. The presented approach proposes a way to use dose rate measurement in inverse modeling approach without the need of a-priori information on emissions. The method proved to be efficient and reliable when applied on the Fukushima accident. The emissions for the 8 main isotopes Xe-133, Cs-134, Cs-136, Cs-137, Ba-137m, I-131, I-132 and Te-132 have been assessed. The Daiichi power plant events (such as ventings, explosions…) known to have caused atmospheric releases are well identified in

  17. A study of total measurement error in tomographic gamma scanning to assay nuclear material with emphasis on a bias issue for low-activity samples

    International Nuclear Information System (INIS)

    Burr, T.L.; Mercer, D.J.; Prettyman, T.H.

    1998-01-01

    Field experience with the tomographic gamma scanner to assay nuclear material suggests that the analysis techniques can significantly impact the assay uncertainty. For example, currently implemented image reconstruction methods exhibit a positive bias for low-activity samples. Preliminary studies indicate that bias reduction could be achieved at the expense of increased random error variance. In this paper, the authors examine three possible bias sources: (1) measurement error in the estimated transmission matrix, (2) the positivity constraint on the estimated mass of nuclear material, and (3) improper treatment of the measurement error structure. The authors present results from many small-scale simulation studies to examine this bias/variance tradeoff for a few image reconstruction methods in the presence of the three possible bias sources

  18. High-sensitive and rapid detection of Mycobacterium tuberculosis infection by IFN-γ release assay among HIV-infected individuals in BCG-vaccinated area

    Directory of Open Access Journals (Sweden)

    Jiang Weimin

    2009-05-01

    Full Text Available Abstract Background An accurate test for Mycobacterium tuberculosis infection is urgently needed in immunosuppressed populations. The aim of this study was to investigate the diagnostic power of enzyme-linked immunospot (ELISPOT-based IFN-γ release assay in detecting active and latent tuberculosis in HIV-infected population in bacillus Calmette-Guerin (BCG-vaccinated area. A total of 100 HIV-infected individuals including 32 active tuberculosis patients were recruited. An ELISPOT-based IFN-γ release assay, T-SPOT.TB, was used to evaluate the M. tuberculosis ESAT-6 and CFP-10 specific IFN-γ response. Tuberculin skin test (TST was performed for all recruited subjects. Results The subjects were divided into group HIV+ATB (HIV-infected individuals with active tuberculosis, n = 32, group HIV+LTB (HIV-infected individuals with positive results of T-SPOT.TB assay, n = 46 and group HIV only (HIV-infected individuals with negative results of T-SPOT.TB assay and without evidence of tuberculosis infection, n = 22. In group HIV+ATB and HIV+LTB, T-SPOT.TB positive rate in subjects with TST P 85% in patients with TB treatment for less than 1 month and CD4+ T cells ≥200/μl, while for patients treated for more than 3 months and CD4+ T cells Conclusion ELISPOT-based IFN-γ release assay is more sensitive and rapid for the diagnosis of TB infection in Chinese HIV-infected individuals with history of BCG vaccination, and could be an effective tool for guiding preventive treatment with isoniazid in latently infected people and for TB control in China.

  19. Evaluation of accuracy and uncertainty of ELISA assays for the determination of interleukin-4, interleukin-5, interferon-gamma and tumor necrosis factor-alpha

    DEFF Research Database (Denmark)

    Borg, Lone; Kristiansen, Jesper; Christensen, Jytte M

    2002-01-01

    . However, models for establishing the traceability and uncertainty of immunoassay results are lacking. Sandwich enzyme-linked immunosorbent assays (ELISAs) were developed for determination of the human cytokines interleukin-4 (IL-4), interleukin-5 (IL-5), interferon-y (IFN-gamma) and tumor necrosis factor-alpha...... (TNF-alpha). The accuracy of each of the assays was evaluated in the ranges of 1-15 microg/l (IL-4), 0.001-1 microg/l (IL-5), 0.5-2.5 microg/l (IFN-T) and 0.14-2.2 microg/l (TNF-alpha). Other evaluated performance characteristics were the limit of detection (LOD), immunological specificity......) of the assessed ELISAs was found to be in the range of 11-18%, except for IL-5 where RSDA increased at decreasing concentrations. The LOD was 0.12 microg/l, 0.0077 microg/l, 0.0069 microg/l and 0.0063 microg/l for IL-4, IL-5, IFN-gamma and TNF-alpha, respectively. Traceability to the WHO IS was established...

  20. Use of delayed gamma rays for active non-destructive assay of {sup 235}U irradiated by pulsed neutron source (plasma focus)

    Energy Technology Data Exchange (ETDEWEB)

    Andola, Sanjay; Niranjan, Ram [Applied Physics Division, Bhabha Atomic Research Centre, Mumbai 400085 (India); Kaushik, T.C., E-mail: tckk@barc.gov.in [Applied Physics Division, Bhabha Atomic Research Centre, Mumbai 400085 (India); Rout, R.K. [Applied Physics Division, Bhabha Atomic Research Centre, Mumbai 400085 (India); Kumar, Ashwani; Paranjape, D.B.; Kumar, Pradeep; Tomar, B.S.; Ramakumar, K.L. [Radioanalytical Chemistry Division, Bhabha Atomic Research Centre, Mumbai 400085 (India); Gupta, S.C. [Applied Physics Division, Bhabha Atomic Research Centre, Mumbai 400085 (India)

    2014-07-01

    A pulsed neutron source based on plasma focus device has been used for active interrogation and assay of {sup 235}U by monitoring its delayed high energy γ-rays. The method involves irradiation of fissile material by thermal neutrons obtained after moderation of a burst of neutrons emitted upon fusion of deuterium in plasma focus (PF) device. The delayed gamma rays emitted from the fissile material as a consequence of induced fission were detected by a large volume sodium iodide (NaI(Tl)) detector. The detector is coupled to a data acquisition system of 2k input size with 2k ADC conversion gain. Counting was carried out in pulse height analysis mode for time integrated counts up to 100 s while the temporal profile of delayed gamma has been obtained by counting in multichannel scaling mode with dwell time of 50 ms. To avoid the effect of passive (natural) and active (from surrounding materials) backgrounds, counts have been acquired for gamma energy between 3 and 10 MeV. The lower limit of detection of {sup 235}U in the oxide samples with this set-up is estimated to be 14 mg.

  1. Assay of uranium in fused salt cake generated at the natural uranium metal fuel fabrication plants by gamma-ray spectrometry

    International Nuclear Information System (INIS)

    Kalsi, P.C.; Bhanu, A.U.; Sahoo, S.; Iyer, R.H.

    1986-01-01

    A passive gamma-ray spectroscopic method is employed for the assay of uranium in fused salt cake, a scrap produced at the natural uranium metal fuel fabrication plants. The method makes use of NaI(TI) detector coupled with a multichannel analyser. The 1 MeV gamma-ray of 238 U was used for the calibration. The calibration curve was made by counting synthetic mixtures made of U 3 O 8 powder, the heat treatment salt and iron in the form of fine powder. The uranium content in these synthetic mixtures was kept in the range of 1-11 per cent. 23 lots of the fused salt cake taken from three different batches of the salt cake were then analysed by this method. The uranium content of fused salt cake was found to be in the range of 1.70-11.43 per cent. To compare the gamma spectrometric results with a completely independent method, chemical analysis of all the fused salt cakes were also carried out. The NDA results were found to agree within ± 17 per cent with the chemical analysis results. (author)

  2. Analysis of the impact of random summing on passive assay of pebble bed reactor fuel using gamma-ray spectrometry

    Science.gov (United States)

    Chen, J.; Hawari, A. I.

    2007-08-01

    Pebble bed reactors (PBR) are characterized by multi-pass fuel systems in which spherical fuel pebbles are circulated through the core until they reach a proposed burnup limit. The fuel is assayed on-line to ensure that the burnup limit is not breached. However, random summing effects can impact the response of the burnup measurement system and result in distortions that degrade the accuracy of the assay results. Monte Carlo analysis was performed to estimate the magnitude and effect of random summing on the absolute and relative indicators that have been identified as usable in on-line assay. For a throughput rate of 10 5 counts/s and trapezoidal pulse shaping of the signals, the results show that absolute indicators suffer from severe distortions due to this effect. Relative indicators are found to be resistant to random summing with the deviation in the ratio of peak areas remaining less than 5-15% depending on pulse width.

  3. Cryogenic gamma detectors enable direct detection of 236U and minor actinides for non-destructive assay

    International Nuclear Information System (INIS)

    Miguel Velazquez; Jonathan Dreyer; Drury, O.B.; Friedrich, Stephan; Saleem Salaymeh

    2016-01-01

    We demonstrate the utility of a superconducting transition edge sensor (TES) γ-ray detector with high energy resolution and low Compton background for nondestructive assay (NDA) of a uranium sample from reprocessed nuclear fuel. We show that TES γ-detectors can separate low-energy actinide γ-emissions from the background and nearby lines, even from minor isotopes whose signals are often obscured in NDA with conventional Ge detectors. Superconducting γ-detectors may therefore bridge the gap between high-accuracy destructive assay (DA) and easier-to-use NDA. (author)

  4. Inhibition of sup 125 I organification and thyroid hormone release by interleukin-1, tumor necrosis factor-alpha, and interferon-gamma in human thyrocytes in suspension culture

    Energy Technology Data Exchange (ETDEWEB)

    Sato, K.; Satoh, T.; Shizume, K.; Ozawa, M.; Han, D.C.; Imamura, H.; Tsushima, T.; Demura, H.; Kanaji, Y.; Ito, Y. (Institute of Clinical Endocrinology, Tokyo (Japan))

    1990-06-01

    To elucidate the mechanism of decreased 131I uptake by the thyroid gland in patients with subacute thyroiditis and painless thyroiditis, human thyroid follicles were cultured with interleukin-1 (IL-1), tumor necrosis factor-alpha (TNF alpha), and/or interferon-gamma (IFN gamma), and the effects of these cytokines on thyroid function were studied in vitro. When human thyrocytes were cultured in RPMI-1640 medium containing 0.5% fetal calf serum and TSH for 5-8 days, the cells incorporated 125I, synthesized de novo (125I)iodotyrosines and (125I)iodothyronines, and secreted (125I)T4 and (125I)T3 into the medium. IL-1 alpha and IL-1 beta inhibited 125I incorporation and (125I)iodothyronine release in a concentration-dependent manner. The minimal inhibitory effect was detected at 10 pg/ml. Electron microscopic examination revealed a marked decrease in lysosome formation in IL-1-treated thyrocytes. TNF alpha and IFN gamma also inhibited thyroid function in a concentration-dependent manner. Furthermore, when thyrocytes were cultured with IL-1, TNF alpha and IFN gamma, these cytokines more than additively inhibited thyroid function. Although the main mechanism of 131I uptake suppression in the thyroid gland in subacute thyroiditis is due to cellular damage and suppression of TSH release, our present findings suggest that IL-1, TNF alpha, and IFN gamma produced in the inflammatory process within the thyroid gland further inhibit iodine incorporation and at least partly account for the decreased 131I uptake by the thyroid gland in destruction-induced hyperthyroidism.

  5. Inhibition of 125I organification and thyroid hormone release by interleukin-1, tumor necrosis factor-alpha, and interferon-gamma in human thyrocytes in suspension culture

    International Nuclear Information System (INIS)

    Sato, K.; Satoh, T.; Shizume, K.; Ozawa, M.; Han, D.C.; Imamura, H.; Tsushima, T.; Demura, H.; Kanaji, Y.; Ito, Y.

    1990-01-01

    To elucidate the mechanism of decreased 131I uptake by the thyroid gland in patients with subacute thyroiditis and painless thyroiditis, human thyroid follicles were cultured with interleukin-1 (IL-1), tumor necrosis factor-alpha (TNF alpha), and/or interferon-gamma (IFN gamma), and the effects of these cytokines on thyroid function were studied in vitro. When human thyrocytes were cultured in RPMI-1640 medium containing 0.5% fetal calf serum and TSH for 5-8 days, the cells incorporated 125I, synthesized de novo [125I]iodotyrosines and [125I]iodothyronines, and secreted [125I]T4 and [125I]T3 into the medium. IL-1 alpha and IL-1 beta inhibited 125I incorporation and [125I]iodothyronine release in a concentration-dependent manner. The minimal inhibitory effect was detected at 10 pg/ml. Electron microscopic examination revealed a marked decrease in lysosome formation in IL-1-treated thyrocytes. TNF alpha and IFN gamma also inhibited thyroid function in a concentration-dependent manner. Furthermore, when thyrocytes were cultured with IL-1, TNF alpha and IFN gamma, these cytokines more than additively inhibited thyroid function. Although the main mechanism of 131I uptake suppression in the thyroid gland in subacute thyroiditis is due to cellular damage and suppression of TSH release, our present findings suggest that IL-1, TNF alpha, and IFN gamma produced in the inflammatory process within the thyroid gland further inhibit iodine incorporation and at least partly account for the decreased 131I uptake by the thyroid gland in destruction-induced hyperthyroidism

  6. Preliminary assays for lemongrass essential oil ecotoxicological test in D. similis and C. silvestrii submitted to gamma radiation

    International Nuclear Information System (INIS)

    Gimiliani, Giovana T.; Rogero, Sizue O.; Rogero, Jose R.; Cruz, Aurea S.

    2011-01-01

    Pharmaceutical products are of great interest in ecotoxicological studies due to being found some of these products in the superficial waters and sediments, water and sewage treatment effluents. It was verified an increase of insect repellent chemical products in the aquatic environment because of the increase of diseases transmitted by mosquitoes like dengue. As these compounds show toxicity, the use of essential oils natural products with repellent properties is increasing and the literature about the impact in the aquatic environment is scarce. The hydric frame would suffer natural radiation and radiations from energy generation nuclear plants impacts fall out of tests and nuclear accidents. There is no universal definition of environmental protection and there are few studies on radiation effects in the aquatic environment. In this study was determined the lemon grass essential oil toxicity level as well as the lethal dose of ionizing radiation, LD 50 , in aquatic organisms. Cytotoxicity test was performed by in vitro neutral red uptake method in NCTC clone L929 cell line. In the LD 50 test aquatic organisms were submitted to gamma radiation. The essential oil of lemongrass Cymbopogon flexuosus showed cytotoxicity index IC 50 about 50μg.mL -1 . The LD 50 for Daphnia similis was 242 Gy and Ceriodaphnia silvestrii about 525 Gy. Studies will be continued with acute and chronic ecotoxicological tests of lemongrass essential oil in natural organisms and in organisms submitted to gamma radiation, utilizing the results obtained in this work. (author)

  7. Preliminary assays for lemongrass essential oil ecotoxicological test in D. similis and C. silvestrii submitted to gamma radiation

    Energy Technology Data Exchange (ETDEWEB)

    Gimiliani, Giovana T.; Rogero, Sizue O.; Rogero, Jose R., E-mail: gtgimiliani@ipen.br [Instituto de Pesquisas Energeticas e Nucleares (IPEN/CNEN-SP), Sao Paulo, SP (Brazil); Cruz, Aurea S. [Instituto Adolfo Lutz, Sao Paulo, SP (Brazil). Culturas Celulares

    2011-07-01

    Pharmaceutical products are of great interest in ecotoxicological studies due to being found some of these products in the superficial waters and sediments, water and sewage treatment effluents. It was verified an increase of insect repellent chemical products in the aquatic environment because of the increase of diseases transmitted by mosquitoes like dengue. As these compounds show toxicity, the use of essential oils natural products with repellent properties is increasing and the literature about the impact in the aquatic environment is scarce. The hydric frame would suffer natural radiation and radiations from energy generation nuclear plants impacts fall out of tests and nuclear accidents. There is no universal definition of environmental protection and there are few studies on radiation effects in the aquatic environment. In this study was determined the lemon grass essential oil toxicity level as well as the lethal dose of ionizing radiation, LD{sub 50}, in aquatic organisms. Cytotoxicity test was performed by in vitro neutral red uptake method in NCTC clone L929 cell line. In the LD{sub 50} test aquatic organisms were submitted to gamma radiation. The essential oil of lemongrass Cymbopogon flexuosus showed cytotoxicity index IC{sub 50} about 50{mu}g.mL{sup -1}. The LD{sub 50} for Daphnia similis was 242 Gy and Ceriodaphnia silvestrii about 525 Gy. Studies will be continued with acute and chronic ecotoxicological tests of lemongrass essential oil in natural organisms and in organisms submitted to gamma radiation, utilizing the results obtained in this work. (author)

  8. Radionuclides release from re-irradiated fuel under high temperature and pressure conditions. Gamma-ray measurements of VEGA-5 test

    Energy Technology Data Exchange (ETDEWEB)

    Hidaka, Akihide; Kudo, Tamotsu; Nakamura, Takehiko; Kanazawa, Toru; Kiuchi, Toshio; Uetsuka, Hiroshi [Japan Atomic Energy Research Inst., Tokai, Ibaraki (Japan). Tokai Research Establishment

    2003-03-01

    The VEGA (Verification Experiments of radionuclides Gas/Aerosol release) program is being performed at JAERI to clarify mechanisms of radionuclides release from irradiated fuel during severe accidents and to improve source term predictability. The fifth VEGA-5 test was conducted in January 2002 to confirm the reproducibility of decrease in cesium release under elevated pressure that was observed in the VEGA-2 test and to investigate the release behavior of short-life radionuclides. The PWR fuel of 47 GWd/tU after about 8.2 years of cooling was re-irradiated at Nuclear Safety Research Reactor (NSRR) for 8 hours before the heat-up test. After that, the two pellets of 10.9 g without cladding were heated up to about 2,900 K at 1.0 MPa under the inert He condition. The experiment reconfirmed the decrease in cesium release rate under the elevated pressure. The release data on short-life radionuclides such as Ru-103, Ba-140 and Xe-133 that have never been observed in the previous VEGA tests without re-irradiation was obtained using the {gamma} ray measurement. (author)

  9. A new assay for cytotoxic lymphocytes, based on a radioautographic readout of 111In release, suitable for rapid, semi-automated assessment of limit-dilution cultures

    International Nuclear Information System (INIS)

    Shortman, K.; Wilson, A.

    1981-01-01

    A new assay for cytotoxic T lymphocytes is described, of general application, but particularly suitable for rapid, semi-automated assessment of multiple microculture tests. Target cells are labelled with high efficiency and to high specific activity with the oxine chelate of 111 indium. After a 3-4 h incubation of test cells with 5 X 10 3 labelled target cells in V wells of microtitre trays, samples of the supernatant are spotted on paper (5 μl) or transferred to soft-plastic U wells (25-50 μl) and the 111 In release assessed by radioautography. Overnight exposure of X-ray film with intensifying screens at -70 0 C gives an image which is an intense dark spot for maximum release, a barely visible darkening with the low spontaneous release, and a definite positive with 10% specific lysis. The degree of film darkening, which can be quantitated by microdensitometry, shows a linear relationship with cytotoxic T lymphocyte dose up to the 40% lysis level. The labelling intensity and sensitivity can be adjusted over a wide range, allowing a single batch of the short half-life isotope to serve for 2 weeks. The 96 assays from a single tray are developed simultaneously on a single small sheet of film. Many trays can be processed together, and handling is rapid if 96-channel automatic pipettors are used. The method allows rapid visual scanning for positive and negative limit dilution cultures in cytotoxic T cell precursor frequency and specificity studies. In addition, in conjunction with an automated densitometer designed to scan microtitre trays, the method provides an efficient alternative to isotope counting in routine cytotoxic assays. (Auth.)

  10. Standard test method for nondestructive assay of special nuclear material holdup using Gamma-Ray spectroscopic methods

    CERN Document Server

    American Society for Testing and Materials. Philadelphia

    2007-01-01

    1.1 This test method describes gamma-ray methods used to nondestructively measure the quantity of 235U, or 239Pu remaining as holdup in nuclear facilities. Holdup occurs in all facilities where nuclear material is processed, in process equipment, in exhaust ventilation systems and in building walls and floors. 1.2 This test method includes information useful for management, planning, selection of equipment, consideration of interferences, measurement program definition, and the utilization of resources (1, 2, 3, 4). 1.3 The measurement of nuclear material hold up in process equipment requires a scientific knowledge of radiation sources and detectors, transmission of radiation, calibration, facility operations and error analysis. It is subject to the constraints of the facility, management, budget, and schedule; plus health and safety requirements; as well as the laws of physics. The measurement process includes defining measurement uncertainties and is sensitive to the form and distribution of the material...

  11. Influence of age and gender in response to {gamma}-radiation in Portuguese individuals using chromosomal aberration assay - Preliminary findings

    Energy Technology Data Exchange (ETDEWEB)

    Martins, V.; Antunes, A.C. [Instituto Tecnologico e Nuclear, Unidade de Proteccao e Seguranca Radiologica, Dosimetry and Radiobiology Group, E.N. 10, Apartado 21, 2686-953 Sacavem (Portugal); Cardoso, J.; Santos, L. [Instituto Tecnologico e Nuclear, Unidade de Proteccao e Seguranca Radiologica, Metrology Laboratory of Ionizing Radiation, E.N. 10, Apartado 21, 2686-953 Sacavem (Portugal); Gil, O. Monteiro, E-mail: octavia.gil@itn.pt [Instituto Tecnologico e Nuclear, Unidade de Proteccao e Seguranca Radiologica, Dosimetry and Radiobiology Group, E.N. 10, Apartado 21, 2686-953 Sacavem (Portugal)

    2011-09-15

    Cytogenetic indicators are widely used in radiobiology to evaluate effects of ionizing radiation since dicentric chromosomes (Dic) are almost exclusively induced by ionizing radiation, and spontaneous frequency of Dic is very low in the healthy general population (about one Dic per 1000 cells). A particular interest of biodosimetry has been not only to obtain absorbed dose estimates using adequate calibration curves, under the assumption that all individuals respond equally to radiation-induced chromosome aberrations, but also to find a way to demonstrate inter-individual radiosensitivity and a possible correlation with age and gender. Thus, the objective of this preliminary work was the evaluation of the influence of age and gender on the outcome of cytogenetic biomarkers after {gamma}-irradiation. Samples of peripheral blood lymphocytes from six healthy, non-smoker, donors from both genders (three men and three women), in the range of 20 to 49 years, were irradiated with doses from 0 Gy to 3 Gy air kerma, using a {sup 60}Co gamma rays source with a dose rate from 170-180 mGy/min. A clear dose-dependent increase in terms of aberrant cells excluding gaps (ACEG) and Dic was observed for all donors. Our preliminary results suggest, in the higher dose level evaluated (3 Gy), a larger intervariability among individuals for Dic, with females apparently more sensitive than males (P<0.05). Considering the different age groups, male donors showed a decrease, with age, for Dic and ACEG at the higher dose and also, for the background level, in case of ACEG. Future work will consider the study of more individuals, from both genders and different ages, in order to verify if this tendency persists and to enable the implementation of a dose-response calibration curve at Instituto Tecnologico e Nuclear for the Portuguese population, to quantify the biological dose in case of a radiological accident or emergency.

  12. A method of radiocompetitive assay of total thyroxine in the serum by means of enzymatic release of thyroxine from the transporting proteins

    International Nuclear Information System (INIS)

    Snarski, A.; Wyrwinski, J.

    1978-01-01

    Pepsin causes denaturation of the transporting proteins and liberates thyroxine which can be assayed by the radiocompetitive method. Change of the pH of the medium from acid to alkaline inactivates irreveribly pepsin. The enzymatic release of thyroxine is much simpler that the method of ethanol extraction and thermal denaturation of the transporting proteins applied up to now. The new technique of thyroxine release has been introduced for radiocompetitive determination of thyroxine using dextran coated charcoal for adsorption of the free hormone. A new method has been elaborated for preparation of working standards of thyroxine in a mixture of pepsin solution with hormone-free serum. The method is efficient and rapid. The normal range is from 50 to 130 nanomol/l. Over 7 000 determinations were done as yet in patients with suspected thyroid function disturbances. (author)

  13. Decreased release of histamine and sulfidoleukotrienes by human peripheral blood leukocytes after wasp venom immunotherapy is partially due to induction of IL-10 and IFN-gamma production of T cells.

    Science.gov (United States)

    Pierkes, M; Bellinghausen, I; Hultsch, T; Metz, G; Knop, J; Saloga, J

    1999-02-01

    Recent studies provide evidence that venom immunotherapy (VIT) alters the pattern of cytokine production by inducing an allergen-specific T-cell shift in cytokine expression from TH2 (IL-4, IL-5) to TH1 (IFN-gamma) cytokines and also inducing the production of IL-10. This study was carried out to analyze whether these changes in cytokine production of T cells already observed 1 week after the initiation of VIT in subjects with wasp venom allergy also influence the reactivity of effector cells, such as mast cells and basophils. All subjects included in this study had a history of severe systemic allergic reactions to wasp stings and positive skin test responses with venom and venom-specific IgE in the sera. Peripheral blood leukocytes were isolated before and after the initiation of VIT (rush therapy reaching a maintenance dose of 100 microg venom injected subcutaneously within 1 week) and preincubated with or without addition of IL-10, IFN-gamma, IL-10 + IFN-gamma, anti-IL-10, or anti-IFN-gamma. After stimulation with wasp venom, histamine and sulfidoleukotriene release were assessed by ELISA and compared with spontaneous release and total histamine content. After the induction of VIT, venom-induced absolute and relative histamine and sulfidoleukotriene release were reduced. This was at least partially due to the induction of IFN-gamma and IL-10 production, because (1) neutralization of IL-10 and IFN-gamma by mAbs partially restored the release after the initiation of VIT and (2) the addition of exogenous IFN-gamma and IL-10 caused a statistically significant diminution of the venom-induced histamine and sulfidoleukotriene release before VIT. Depletion of CD2(+) T cells also restored the releasability after VIT. These data indicate that T cells (producing IL-10 and IFN-gamma after VIT) play a key role for the inhibition of histamine and sulfidoleukotriene release of effector cells.

  14. Development and evaluation of an interferon gamma assay for the diagnosis of tuberculosis in red deer experimentally infected with Mycobacterium bovis.

    Science.gov (United States)

    Risalde, María Ángeles; Thomas, Jobin; Sevilla, Iker; Serrano, Miriam; Ortíz, Jose Antonio; Garrido, Joseba; Domínguez, Mercedes; Domínguez, Lucas; Gortázar, Christian; Ruíz-Fons, Jose Francisco

    2017-11-16

    Red deer (Cervus elaphus) is regarded as an epidemiologically relevant host for Mycobacterium bovis (M. bovis) and closely related members of the Mycobacterium tuberculosis complex that cause animal tuberculosis (TB). The standard antemortem screening test for the detection of TB in deer is the intradermal tuberculin skin test, but the detection of interferon-gamma (IFNγ) produced by white blood cells exposed to M. bovis antigens can be used as an alternative or supplemental assay in most TB eradication/control programs. This study aims to develop an in-house sandwich ELISA for deer IFNγ, based on the cross-reactivity of the antibodies to both cervid and bovine IFNγ, and to evaluate the potential of this assay to detect M. bovis-infected red deer in response to the in vitro stimulation of whole-blood cells with bovine purified protein derivative (bPPD), p22 protein complex derived from bPPD or using the specific tuberculous mycobacterial proteins ESAT-6/CFP-10, Rv3615c and Rv3020c. The positive control stimulant used in this study was pokeweed mitogen, which resulted in a consistent induction of IFNγ in samples from red deer, thus allowing the interpretation of the assay. The percentage of animals correctly classified by this technique as M. bovis non-infected was 100%. The detection of infected animals as positive was high and ranged widely depending upon the antigen and the cut-off value applied, as well as the time after infection. Our findings indicate that this protocol may serve as a reliable assay for the antemortem diagnosis of TB from the initial stage of M. bovis-infection, and may also be adequately sensitive. The suggested optimal antigens and cut-off are bPPD, p22 and the combination of ESAT-6/CFP-10 and Rv3020c with a 0.05 Δ optical density, which yielded a up to 100% correct classification of TB positive and negatve red deer under our experimental conditions. This technique will aid in TB testing of farmed and translocated deer. Future studies

  15. Interferon-γ release assays for the diagnosis of latent Mycobacterium tuberculosis infection: a systematic review and meta-analysis

    DEFF Research Database (Denmark)

    Diel, R; Goletti, D; Ferrara, G

    2011-01-01

    We conducted a systematic review and meta-analysis to compare the accuracy of the QuantiFERON-TB® Gold In-Tube (QFT-G-IT) and the T-SPOT®.TB assays with the tuberculin skin test (TST) for the diagnosis of latent Mycobacterium tuberculosis infection (LTBI). The Medline, Embase and Cochrane databases...... of IGRAs varied 98-100%. In immunocompetent adults, NPV for progression to tuberculosis within 2 yrs were 97.8% for T-SPOT®.TB and 99.8% for QFT-G-IT. When test performance of an immunodiagnostic test was not restricted to prior positivity of another test, progression rates to tuberculosis among IGRA...

  16. Tuberculin skin test and QuantiFERON® assay in young children investigated for tuberculosis in South Africa

    NARCIS (Netherlands)

    Moyo, S.; Isaacs, F.; Gelderbloem, S.; Verver, S.; Hawkridge, A. J.; Hatherill, M.; Tameris, M.; Geldenhuys, H.; Workman, L.; Pai, M.; Hussey, G.; Hanekom, W. A.; Mahomed, H.

    2011-01-01

    Although the literature on interferon-gamma release assays on tuberculosis (TB) in children has increased, data pertaining to young children remain relatively limited. To compare results from the tuberculin skin test (TST) and the QuantiFERON®-TB Gold In-Tube assay (QFT) in children aged <3 years

  17. A dual beam study with isotopic X- and gamma-rays for in vivo lymph pool assay

    International Nuclear Information System (INIS)

    Bolin, F.P.; Preuss, L.E.; Jedlenski, D.E.; Beninson, J.

    1986-01-01

    Dual beam absorptiometry utilizes differential absorption of X- and gamma rays of differing energy to determine an absorber's component ratio. This principle has been applied to diverse physical and biological problems. Our method, using the 22 and 88 keV emissions from 109 Cd, resolves the lean and non-lean mammalian tissue fractions. Accuracy of 1%, and reproducibility of 1-2% is attainable in in vitro measurements. Techniques have been developed to apply this system to the more complicated applications involved in human studies. A scanning device capable of measuring limbs has been developed. Mathematical treatment provides an integrated value of lean fraction over the scanned area. Lymphedema is a painful malady in which blockage of lymph flow causes swelling and distension of the extremities. Compressive therapy is the preferred medical treatment. There has been no accurate quantitative index of the efficacy of this therapy. Our research program uses dual beam analysis as a unique quantitative measure of the lymph transport. Lymph pool change is equated to change in the lean. Five measurements are made on subjects undergoing a two week regimen of compressive therapy. These absorptiometric results are analyzed for correlation to other indices of treatment effect. Data shows a progressive decrease in the lean tissue component over the treatment period. Changes seen vary with the individual and the severity of involvement. This study showed that the largest transport rate occurs in the first treatment days. Absorptiometry accurately monitors total adipose mass, total non-adipose mass, extremety cross section, and change in lymph pooling. (orig.)

  18. Revisiting the IFN-γ release assay: Whole blood or PBMC cultures? - And other factors of influence

    DEFF Research Database (Denmark)

    Hartmann, Sofie Bruun; Emnéus, Jenny; Wolff, Anders

    2016-01-01

    light on external factors that could influence the read out in terms of IFN-γ levels. It was found that optimal culture conditions varied between individual animals; when polyclonal activated, cells from whole blood cultures were most responsive, but when activated specifically, the optimal cell....... However, there is no consensus whether to use whole blood cultures or purified PBMCs for the assay, and both cell populations are being used and results compared. Therefore the aim of this study was to compare different culture settings using immune cells from previously vaccinated calves, and to shed...... concentration/population varied with whole blood, 10 × 106 cells/ml PBMC and 5 × 106 cells/ml PBMC being the highest performing conditions. A further investigation of the distribution of cell populations in PBMCs compared to whole blood was conducted, and a significant (p

  19. Optimization of interferon gamma ELISPOT assay to detect human cytomegalovirus specific T-cell responses in solid organ transplants.

    Science.gov (United States)

    Abate, Davide; Saldan, Alda; Forner, Gabriella; Tinto, Daniel; Bianchin, Alice; Palù, Giorgio

    2014-02-01

    Assessing the CMV specific CMI in transplant subjects represents a promising strategy to determine the risk of infection on individual basis. In this study 61 adult CMV IgG seropositive solid organ transplant recipients were examined in order to improve the efficacy of CMI detection. For this purpose, pair-wise comparisons were conducted comparing positive control stimuli PWM and PMA/iono and CMV stimuli, pp65 peptide pool and whole CMV particle. Rosette pre-depletion of blood was also investigated for detecting CD4+ or CD8+ T-cell responses using the IFN-g ELISPOT assay. In the time-points 30-180 days after transplantation, PMA/iono produced statistically significant higher responses compared to PWM, probably because PMA/iono activation pathway is independent from the effect of immunosuppressive drugs. The data showed that 11% of transplant patients displayed very low or undetectable responses to pp65 peptide pool antigen while having sustained high responses to whole CMV particle. In addition, in all the subjects analyzed, CMI responses to CMV particle produced a statistically significant higher number of spots compared to pp65 peptide pool antigen. Rosette pre-depletion of whole blood proved to be effective in detecting CD4+ or CD8+ T-cell responses similarly to flow cytometry. Taken together, the following recommendations are suggested to optimize the CMV-ELISPOT for transplantation settings: (1) use PMA/iono as positive control; (2) whole virus particle should be used to avoid peptide-related false negative responses; (3) a rosette pre-depletion step may be useful to detect CD4+ or CD8+ T-cell responses. Copyright © 2013 Elsevier B.V. All rights reserved.

  20. Delayed gamma-ray spectroscopy with lanthanum bromide detector for non-destructive assay of nuclear material

    Science.gov (United States)

    Favalli, Andrea; Iliev, Metodi; Ianakiev, Kiril; Hunt, Alan W.; Ludewigt, Bernhard

    2018-01-01

    High-energy delayed γ-ray spectroscopy is a potential technique for directly assaying spent fuel assemblies and achieving the safeguards goal of quantifying nuclear material inventories for spent fuel handling, interim storage, reprocessing facilities, repository sites, and final disposal. Requirements for the γ-ray detection system, up to ∼6 MeV, can be summarized as follows: high efficiency at high γ-ray energies, high energy resolution, good linearity between γ-ray energy and output signal amplitude, ability to operate at very high count rates, and ease of use in industrial environments such as nuclear facilities. High Purity Germanium Detectors (HPGe) are the state of the art and provide excellent energy resolution but are limited in their count rate capability. Lanthanum Bromide (LaBr3) scintillation detectors offer significantly higher count rate capabilities at lower energy resolution. Thus, LaBr3 detectors may be an effective alternative for nuclear spent-fuel applications, where count-rate capability is a requirement. This paper documents the measured performance of a 2" (length) × 2" (diameter) of LaBr3 scintillation detector system, coupled to a negatively biased PMT and a tapered active high voltage divider, with count-rates up to ∼3 Mcps. An experimental methodology was developed that uses the average current from the PMT's anode and a dual source method to characterize the detector system at specific very high count rate values. Delayed γ-ray spectra were acquired with the LaBr3 detector system at the Idaho Accelerator Center, Idaho State University, where samples of ∼3g of 235U were irradiated with moderated neutrons from a photo-neutron source. Results of the spectroscopy characterization and analysis of the delayed γ-ray spectra acquired indicate the possible use of LaBr3 scintillation detectors when high count rate capability may outweigh the lower energy resolution.

  1. Ultraviolet B irradiation induces changes in the distribution and release of arachidonic acid, dihomo-gamma-linolenic acid, and eicosapentaenoic acid in human keratinocytes in culture

    International Nuclear Information System (INIS)

    Punnonen, K.; Puustinen, T.; Jansen, C.T.

    1987-01-01

    There is increasing evidence that derivatives of 20-carbon polyunsaturated fatty acids, the eicosanoids, play an important role in the inflammatory responses of the human skin. To better understand the metabolic fate of fatty acids in the skin, the effect of ultraviolet B (UVB) irradiation (280-320 nm) on the distribution and release of 14 C-labeled arachidonic acid, dihomo-gamma-linolenic acid, and eicosapentaenoic acid in human keratinocytes in culture was investigated. Ultraviolet B irradiation induced the release of all three 14 C-labeled fatty acids from the phospholipids, especially from phosphatidylethanolamine, and this was accompanied by increased labeling of the nonphosphorus lipids. This finding suggests that UVB induces a significant liberation of eicosanoid precursor fatty acids from cellular phospholipids, but the liberated fatty acids are largely reincorporated into the nonphosphorus lipids. In conclusion, the present study suggests that not only arachidonic acid but also dihomo-gamma-linolenic acid, and eicosapentaenoic acid might be involved in the UVB irradiation-induced inflammatory reactions of human skin

  2. A survey of monitoring and assay systems for release of metals from radiation controlled areas at LANL.

    Energy Technology Data Exchange (ETDEWEB)

    Gruetzmacher, K. M. (Kathleen M.); MacArthur, D. W. (Duncan W.)

    2002-01-01

    At Los Alamos National Laboratory (LANL), a recent effort in waste minimization has focused on scrap metal from radiological controlled areas (RCAs). In particular, scrap metal from RCAs needs to be dispositioned in a reasonable and cost effective manner. Recycling of DOE scrap metals from RCAs is currently under a self-imposed moratorium. Since recycling is not available and reuse is difficult, often metal waste from RCAs, which could otherwise be recycled, is disposed of as low-level waste. Estimates at LANL put the cost of low-level waste disposal at $550 to $4000 per cubic meter, depending on the type of waste and the disposal site. If the waste is mixed, the cost for treatment and disposal can be as high as $50,000 per cubic meter. Disposal of scrap metal as low-level waste uses up valuable space in the low-level waste disposal areas and requires transportation to the disposal site under Department of Transportation (DOT) regulations for low-level waste. In contrast, disposal as non-radioactive waste costs as little as $2 per cubic meter. While recycling is unavailable, disposing of the metal at an industrial waste site could be the best solution for this waste stream. A Green Is Clean (GIC) type verification program needs to be in place to provide the greatest assurance that the waste does not contain DOE added radioactivity. This paper is a review of available and emerging radiation monitoring and assay systems that could be used for scrap metal as part of the LANL GIC program.

  3. Screening health care workers with interferon-γ release assay versus tuberculin skin test: impact on costs and adherence to testing (the SWITCH study).

    Science.gov (United States)

    Wrighton-Smith, Peter; Sneed, Laurie; Humphrey, Frances; Tao, Xuguang; Bernacki, Edward

    2012-07-01

    To determine the price point at which an interferon-γ release assay (IGRA) is less costly than a tuberculin skin test (TST) for health care employee tuberculosis screening. A multidecision tree-based cost model incorporating inputs gathered from time-motion studies and parallel testing by IGRA and TST was conducted in a subset of our employees. Administering a TST testing program costs $73.20 per person screened, $90.80 per new hire, and $63.42 per annual screen. Use of an IGRA for employee health testing is cost saving at an IGRA test cost of $54.83 or less per test and resulted in higher completion rates because of the elimination of the need for a second visit to interpret the TST. Using an IGRA for employee health screening can be an institutional cost saving and results in higher compliance rates.

  4. Controlled release in hard to access places by poly(methyl methacrylate) microcapsules triggered by gamma irradiation

    DEFF Research Database (Denmark)

    Kostrzewska, Malgorzata; Ma, Baoguang; Javakhishvili, Irakli

    2015-01-01

    microcapsules were shown to become permeable after irradiation and release an encapsulated cross-linker, which enables the remotely controlled formation of polydimethylsiloxanes in traditionally unavailable places. Therefore, the activation method has significant implications for industrial application....

  5. Development of a numerical experiment technique to solve inverse gamma-ray transport problems with application to nondestructive assay of nuclear waste barrels

    International Nuclear Information System (INIS)

    Chang, C.J.; Anghaie, S.

    1998-01-01

    A numerical experimental technique is presented to find an optimum solution to an undetermined inverse gamma-ray transport problem involving the nondestructive assay of radionuclide inventory in a nuclear waste drum. The method introduced is an optimization scheme based on performing a large number of numerical simulations that account for the counting statistics, the nonuniformity of source distribution, and the heterogeneous density of the self-absorbing medium inside the waste drum. The simulation model uses forward projection and backward reconstruction algorithms. The forward projection algorithm uses randomly selected source distribution and a first-flight kernel method to calculate external detector responses. The backward reconstruction algorithm uses the conjugate gradient with nonnegative constraint or the maximum likelihood expectation maximum method to reconstruct the source distribution based on calculated detector responses. Total source activity is determined by summing the reconstructed activity of each computational grid. By conducting 10,000 numerical simulations, the error bound and the associated confidence level for the prediction of total source activity are determined. The accuracy and reliability of the simulation model are verified by performing a series of experiments in a 208-ell waste barrel. Density heterogeneity is simulated by using different materials distributed in 37 egg-crate-type compartments simulating a vertical segment of the barrel. Four orthogonal detector positions are used to measure the emerging radiation field from the distributed source. Results of the performed experiments are in full agreement with the estimated error and the confidence level, which are predicted by the simulation model

  6. A fluorescence-coupled assay for gamma aminobutyric acid (GABA reveals metabolic stress-induced modulation of GABA content in neuroendocrine cancer.

    Directory of Open Access Journals (Sweden)

    Joseph E Ippolito

    Full Text Available Pathways involved in the synthesis of the neurotransmitter gamma-aminobutyric acid (GABA have been implicated in the pathogenesis of high grade neuroendocrine (NE neoplasms as well as neoplasms from a non-NE lineage. Using The Cancer Genome Atlas, overexpression of the GABA synthetic enzyme, glutamate decarboxylase 1 (GAD1, was found to be associated with decreased disease free-survival in prostate adenocarcinoma and decreased overall survival in clear cell renal cell carcinomas. Furthermore, GAD1 was found to be expressed in castrate-resistant prostate cancer cell lines, but not androgen-responsive cell lines. Using a novel fluorescence-coupled enzymatic microplate assay for GABA mediated through reduction of resazurin in a prostate neuroendocrine carcinoma (PNEC cell line, acid microenvironment-induced stress increased GABA levels while alkaline microenvironment-induced stress decreased GABA through modulation of GAD1 and glutamine synthetase (GLUL activities. Moreover, glutamine but not glucose deprivation decreased GABA through modulation of GLUL. Consistent with evidence in prokaryotic and eukaryotic organisms that GABA synthesis mediated through GAD1 may play a crucial role in surviving stress, GABA may be an important mediator of stress survival in neoplasms. These findings identify GABA synthesis and metabolism as a potentially important pathway for regulating cancer cell stress response as well as a potential target for therapeutic strategies.

  7. A functional assay to measure postsynaptic gamma-aminobutyric acidB responses in cultured spinal cord neurons: Heterologous regulation of the same K+ channel

    Energy Technology Data Exchange (ETDEWEB)

    Kamatchi, G.L.; Ticku, M.K. (Univ. of Texas Health Science Center, San Antonio (USA))

    1991-02-01

    The stimulation of postsynaptic gamma-aminobutyric acid (GABA)B receptors leads to slow inhibitory postsynaptic potentials due to the influx of K(+)-ions. This was studied biochemically, in vitro in mammalian cultured spinal cord neurons by using 86Rb as a substitute for K+. (-)-Baclofen, a GABAB receptor agonist, produced a concentration-dependent increase in the 86Rb-influx. This effect was stereospecific and blocked by GABAB receptor antagonists like CGP 35 348 (3-aminopropyl-diethoxymethyl-phosphonic acid) and phaclofen. Apart from the GABAB receptors, both adenosine via adenosine1 receptors and 5-hydroxytryptamine (5-HT) via 5-HT1 alpha agonists also increased the 86Rb-influx. These agonists failed to show any additivity between them when they were combined in their maximal concentration. In addition, their effect was antagonized specifically by their respective antagonists without influencing the others. These findings suggest the presence of GABAB, adenosine1 and 5-HT1 alpha receptors in the cultured spinal cord neurons, which exhibit a heterologous regulation of the same K(+)-channel. The effect of these agonists were antagonized by phorbol 12,13-didecanoate, an activator of protein kinase C, and pretreatment with pertussis toxin. This suggests that these agonists by acting on their own receptors converge on the same K(+)-channel through the Gi/Go proteins. In summary, we have developed a biochemical functional assay for studying and characterizing GABAB synaptic pharmacology in vitro, using spinal cord neurons.

  8. Modulation of the release of norepinephrine by gamma-aminobutyric acid and morphine in the frontal cerebral cortex of the rat

    International Nuclear Information System (INIS)

    Peoples, R.W.

    1989-01-01

    Agents that enhance gamma-aminobutyric acid, or GABA, neurotransmission modulate certain effects of opioids, such as analgesia. Opioid analgesia is mediated in part by norepinephrine in the forebrain. In this study, the interactions between morphine and GABAergic agents on release of [ 3 H] norepinephrine from rat frontal cerebral cortical slices were examined. GABA, 5 x 10 -5 -10 -3 M, enhanced potassium stimulated [ 3 H] norepinephrine release and reversed the inhibitory effect of morphine in a noncompetitive manner. GABA did not enhance release of [ 3 H] norepinephrine stimulated by the calcium ionophore A23187. The effect of GABA was reduced by the GABA A receptor antagonists bicuculline methiodide or picrotoxin, and by the selective inhibitor of GABA uptake SKF 89976A, but was blocked completely only when bicuculline methiodide and SKF 89976A were used in combination. The GABA A agonist muscimol, 10 -4 M, mimicked the effect of GABA, but the GABA B agonist (±)baclofen, 10 -4 M, did not affect the release of [ 3 H] norepinephrine in the absence or the presence of morphine. Thus GABA appears to produce this effect by stimulating GABA uptake and GABA A , but not GABA B , receptors. In contrast to the results that would be predicted for an event involving GABA A receptors, however, the effect of GABA did not desensitize, and benzodiazepine agonists did not enhance the effect of GABA at any concentration tested between 10 -8 and 10 -4 M. Thus these receptors may constitute a subclass of GABA A receptors. These results support a role of GABA uptake and GABA A receptors in enhancing the release of norepinephrine and modulating its inhibition by opioids in the frontal cortex of the rat

  9. Modulation of the release of norepinephrine by gamma-aminobutyric acid and morphine in the frontal cerebral cortex of the rat

    Energy Technology Data Exchange (ETDEWEB)

    Peoples, R.W.

    1989-01-01

    Agents that enhance gamma-aminobutyric acid, or GABA, neurotransmission modulate certain effects of opioids, such as analgesia. Opioid analgesia is mediated in part by norepinephrine in the forebrain. In this study, the interactions between morphine and GABAergic agents on release of ({sup 3}H) norepinephrine from rat frontal cerebral cortical slices were examined. GABA, 5 {times} 10{sup {minus}5}-10{sup {minus}3} M, enhanced potassium stimulated ({sup 3}H) norepinephrine release and reversed the inhibitory effect of morphine in a noncompetitive manner. GABA did not enhance release of ({sup 3}H) norepinephrine stimulated by the calcium ionophore A23187. The effect of GABA was reduced by the GABA{sub A} receptor antagonists bicuculline methiodide or picrotoxin, and by the selective inhibitor of GABA uptake SKF 89976A, but was blocked completely only when bicuculline methiodide and SKF 89976A were used in combination. The GABA{sub A} agonist muscimol, 10{sup {minus}4} M, mimicked the effect of GABA, but the GABA{sub B} agonist ({plus minus})baclofen, 10{sup {minus}4} M, did not affect the release of ({sup 3}H) norepinephrine in the absence or the presence of morphine. Thus GABA appears to produce this effect by stimulating GABA uptake and GABA{sub A}, but not GABA{sub B}, receptors. In contrast to the results that would be predicted for an event involving GABA{sub A} receptors, however, the effect of GABA did not desensitize, and benzodiazepine agonists did not enhance the effect of GABA at any concentration tested between 10{sup {minus}8} and 10{sup {minus}4} M. Thus these receptors may constitute a subclass of GABA{sub A} receptors. These results support a role of GABA uptake and GABA{sub A} receptors in enhancing the release of norepinephrine and modulating its inhibition by opioids in the frontal cortex of the rat.

  10. Comparison of some gamma detectors and environmental measurement of small Ar41 releases from a Triga reactor

    International Nuclear Information System (INIS)

    Baers, B.; Kautto, A.M.T.

    1977-11-01

    GM-detectors, liquid- and NaI(Tl)-scintillation detectors and semiconductor detectors were compared in order to measure small airborne Ar 41 activity concentrations. A 12,5 cm x 12,5 cm NaI(Tl)-scintillation detector was used to semiempirically estimate the radiation exposure arising from airborne Ar 41 release passing 5 meters (estimated) above the detector at a distance of 130 meters from a 250 kW Triga-reactor under downwind conditions. The height of the release point was 19 m. The exposure was found to be 0.45 μR/h at an Ar 41 release rate of 18 mCi/h (670 MBq/h) under downwind conditions and at a wind speed of 3 m/s. The mean annual exposure from 1300 hours reactor operation is of the order of 40...100 μR/y (+100%,-50%) at this test point and at a release rate of 2.5...6μCi/s. The maximum exposure at the ground level is at a distance of about 200 meters (approximately 10 x height of chimney) and it is of the order of 100 μR/y. At close distances from the point of release a line source model can be used for the approximate estimation of the exposure. (author)

  11. Effects of acute and sub-acute gamma radiation on photosynthetic release and respiration of three unicellular marine algae

    Energy Technology Data Exchange (ETDEWEB)

    Ehrhardt, J P

    1974-12-31

    Thesis. Lethal doses of irradiation are required before a 50% inactivation of the photosynthetic release is achieved. The chloroplasts, after this treatment, are one and a half times more resistant than the nucleus. The delayed effect is irreversible when it corresponds to a dose in excess of that necessary for the immediate 10% inhibition of the photosynthetic release. A decrease is observed in the respiration during several days after the occurrence of an intermediate increase. This behavior may be considered to be a consequence of the irreversible destruction of the mitochondrial sites. (FR)

  12. Measurement and modeling of gamma-absorbed doses due to atmospheric releases from Los Alamos Meson Physics Facility

    International Nuclear Information System (INIS)

    Bowen, B.M.; Chen, A.I.; Olsen, W.A.; Van Etten, D.M.

    1985-01-01

    Short-term gamma-absorbed doses were measured by one high-pressure ionization chamber (HPIC) at an azimuth of 12 0 from the Los Alamos Meson Physics Facility (LAMPF) stack during the January 1 through February 8 operating cycle. Two HPICs were in the field during the September 8 through December 31 operating cycle, one north and the other north-northeast of the LAMPF stack, but they did not provide reliable data. Meteorological data were also measured at both East Gate and LAMPF. Airborne emission data were taken at the stack. Daily model predictions, based on the integration of modeled 15-min periods, were made for the first LAMPF operating cycle and were compared with the measured data. A comparison of the predicted and measured daily gamma doses due to LAMPF emissions is presented. There is very good correlation between measured and predicted values. During 39-day operating cycles, the model predicted an absorbed dose of 10.3 mrad compared with the 8.8 mrad that was measured, an overprediction of 17%

  13. In vitro release studies of vitamin B12 from poly N-vinyl pyrrolidone /starch hydrogels grafted with acrylic acid synthesized by gamma radiation

    International Nuclear Information System (INIS)

    Eid, M.

    2008-01-01

    Co-polymeric hydrogels containing N-vinyl pyrrolidone and starch grafted with acrylic acid were synthesized by gamma radiation. Their gel contents, grafting process and swelling were evaluated. The gels were also characterized by thermal gravimetric analysis. The gel content found to be increase with increasing the irradiation dose up to 50 kGy then decrease. The grafting percent increase by increasing the percentage of acrylic acid in the grafted hydrogels. The thermal stability and the rate of the thermal decomposition showed to be changed according to the different composition of the hydrogels. It also showed a decrease in the maximum rate of the thermal decomposition by the increasing of the irradiation dose from 20 to 30 kGy and increases by increasing the irradiation dose from 30 to 70 kGy. The hydrogels loaded with vitamin B 12 as drug model, demonstrated a decrease release in acidic medium than the neutral one

  14. Synthesis and characterization of poly(acrylic acid)-g-sodium alginate hydrogel initiated by gamma irradiation for controlled release of chlortetracycline HCl

    International Nuclear Information System (INIS)

    Mohamed, S.F.; Mahmoud, G.A.; Taleb, M.F.A.

    2013-01-01

    pH-Sensitive hydrogel was synthesized by gamma radiation crosslinking for sodium alginate extracted from the marine brown alga Turbinaria decurrens and acrylic acid. Preparation of the hydrogels involved free radical polymerization of a combination of acrylic acid (w = 0.2) and different contents of sodium alginate (w = 0.05, 0.10, and 0.15) in aqueous solution using gamma rays of a 60 Co source at an irradiation dose rate of 1.2 kGy/h. The swelling behavior of the prepared hydrogel was determined by investigating the swelling time, pH of medium, and alginate content in the hydrogel. The results showed that the hydrogel reached the equilibrium swelling state in water after 6 h. The hydrogel was found to be pH responsive. The drug loading and in vitro release properties of the hydrogel were also evaluated using chlortetracycline hydrochloride as the model drug. The adsorption isotherm studies by batching techniques under the effect of different initial feed concentrations of drug, different pH values, and different sodium alginate content of the adsorbent hydrogel were investigated. The diffusion of chlortetracycline hydrochloride within the hydrogel was found to be of non-Fickian character. The kinetic parameters such as the diffusion exponent, diffusion constant, and diffusion coefficient were also evaluated. (author)

  15. Influence of oxygen and long term storage on the profile of volatile compounds released from polymeric multilayer food contact materials sterilized by gamma irradiation

    Energy Technology Data Exchange (ETDEWEB)

    Salafranca, Jesús, E-mail: fjsl@unizar.es [Aragón Institute of Engineering Research (I3A), EINA, Department of Analytical Chemistry, University of Zaragoza, María de Luna 3 (Torres Quevedo Bldg.), 50018 Zaragoza (Spain); Clemente, Isabel, E-mail: isabelclemente1984@gmail.com [Aragón Institute of Engineering Research (I3A), EINA, Department of Analytical Chemistry, University of Zaragoza, María de Luna 3 (Torres Quevedo Bldg.), 50018 Zaragoza (Spain); Isella, Francesca, E-mail: Francesca.Isella@goglio.it [Goglio S.p.A. Packaging Division, Via dell' Industria 7, 21020 Daverio (Italy); Nerín, Cristina, E-mail: cnerin@unizar.es [Aragón Institute of Engineering Research (I3A), EINA, Department of Analytical Chemistry, University of Zaragoza, María de Luna 3 (Torres Quevedo Bldg.), 50018 Zaragoza (Spain); Bosetti, Osvaldo, E-mail: Osvaldo.Bosetti@goglio.it [Goglio S.p.A. Packaging Division, Via dell' Industria 7, 21020 Daverio (Italy)

    2015-06-09

    Highlights: • 13 different food-use multilayers unirradiated and gamma-irradiated were studied. • 60–80 compounds/sample were identified by SPME–GC–MS even after 8-month storage. • Volatile profile of air- and N{sub 2}-filled bags greatly differed after irradiation. • Principal component analysis classified the samples into 4 groups. • Migration from irradiated materials to vapor phase was much lower than EU limits. - Abstract: The profile of volatile compounds released from 13 different multilayer polymeric materials for food use, before and after their exposure to gamma radiation, has been assessed by solid-phase microextraction–gas chromatography–mass spectrometry. Thermosealed bags of different materials were filled with either air or nitrogen to evaluate the oxygen influence. One-third of the samples were analyzed without irradiation, whereas the rest were irradiated at 15 and 25 kGy. Half of the samples were processed just after preparation and the other half was stored for 8 months at room temperature prior to analysis. Very significant differences between unirradiated and irradiated bags were found. About 60–80 compounds were released and identified per sample. A huge peak of 1,3-ditertbutylbenzene was present in most of the irradiated samples. An outstanding reproducibility in all the variables evaluated (chromatograms, oxygen percentage, volume of bags) was noticed. Independently of filling gas, the results of unirradiated materials were almost identical. In contrast, the chromatographic profile and the odor of irradiated bags filled with nitrogen were completely different to those filled with air. Principal component analysis was performed and 86.9% of the accumulated variance was explained with the first two components. The migration of compounds from irradiated materials to the vapor phase was much lower than the limits established in the Commission Regulation (EU) No 10/2011.

  16. In-plant measurements of gamma-ray transmissions for precise K-edge and passive assay of plutonium concentration and isotopic abundance in product solutions at the Tokai Reprocessing Plant

    International Nuclear Information System (INIS)

    Asakura, Y.; Kondo, I.; Masui, J.; Shoji, K.; Russo, P.A.; Hsue, S.T.; Sprinkle, J.K. Jr.; Johnson, S.S.

    1982-01-01

    A field test has been carried out for more than 2 years for determination of plutonium concentration by K-edge absorption densitometry and for determination of plutonium isotopic abundance by transmission-corrected passive gamma-ray spectrometry. This system was designed and built at Los Alamos National Laboratory and installed at the Tokai reprocessing plant of the Power Reactor and Nuclear Fuel Development Corporation as a part of the Tokai Advanced Safeguards Technology Exercise (TASTEX). For K-edge measurement of plutonium concentration, the transmissions at two discrete gamma-ray energies are measured using the 121.1- and 122.1-keV gamma rays from 75 Se and 57 Co. Intensities of the plutonium passive gamma rays in the energy regions between 38 and 51 keV and between 129 and 153 keV are used for determination of the isotopic abundances. More than 200 product solution samples have been measured in a timely fashion during these 2 years. The relative precisions and accuracies of the plutonium concentration measurement are shown to be within 0.6% (1 sigma) in these applications, and those for plutonium isotopic abundances are within 3% for 238 Pu, 0.4% for 239 Pu, 1.2% for 240 Pu, 1.3% for 241 Pu, and 7% for 242 Pu. The time required is 10 min for the concentration assay, 10 min for the isotopics assay, and about 15 min for handling procedures in the laboratory

  17. In-Situ Assay Of Transuranic Radionuclides In The Vadose Zone Using High-Resolution Spectral Gamma Logging - A Hanford Case Study

    International Nuclear Information System (INIS)

    Rohay, V.J.; Henwood, P.; McCain, R.

    2009-01-01

    High-resolution spectral gamma logging in steel-cased boreholes is used to detect and quantify transuranic radionuclides in the subsurface. Pu-239, Pu-241, Am-241, and Np-237 are identified based on characteristic decay gammas. Typical minimum detectable levels are on the order of 20 to 40 nCi/g. In intervals of high transuranic concentrations, gamma rays from other sources may complicate analysis and interpretation. Gamma rays detected in the borehole may originate from three sources: decay of the parent transuranic radionuclide or a daughter; alpha interactions; and interactions with neutrons resulting from either spontaneous fission or alpha particle interactions.

  18. Assay of 6-gingerol in CO2 supercritical fluid extracts of ginger and evaluation of its sustained release from a transdermal delivery system across rat skin.

    Science.gov (United States)

    Chen, Yan; Zhang, Cuiping; Zhang, Mei; Fu, Xiaobing

    2014-07-01

    Ginger has been widely used as healthy food condiment as well as traditional Chinese medicine since antiquity. Multiple potentials of ginger for treatment of various ailments have been revealed. However, the biological half-life of 6-gingerol (a principal pungent ingredient of ginger) is only 7.23 minutes while taken orally. Delivery of ginger compositions by routes other than oral have scarcely been reported. Therefore, we studied a noninvasive transdermal drug delivery system (TDDS) of ginger to bypass hepatic first pass metabolism, avoid gastrointestinal degradation and achieve long persistent release of effective compositions. After establishment of a HPLC analysis method of 6-gingerol, assays of 6-gingerol were performed to compare two kinds of ginger extracts. Then, the characteristics of transdermal delivery of 6-gingerol in TDDS were exhibited. The results showed that the contents of 6-gingerol in two kinds of ginger extracts were significantly different. The maximal delivery percentage of 6-gingerol across rat skin at 20 h was more than 40% in different TDDS formulations. TDDS may provide long-lasting delivery of ginger compounds.

  19. Release to farmers of ''Carioca Arbustivo Precoce 1070'' (CAP-1070), a bushy bean mutant induced by gamma rays in Brazil

    International Nuclear Information System (INIS)

    Tulmann Neto, A.; Albertini, J.

    1989-01-01

    Full text: Seeds of the indeterminate growth type bean cultivar ''Carioca'' have been treated with 32 krad gamma rays. In M 2 , a mutant showing bushy growth type has been selected. The mutant also shows earlier maturity (5-14 days) and therefore was called ''Carioca Arbustivo Precoce 1070'' (CAP-1070). The determinate (bushy) growth habit is due to one recessive gene and earliness is associated with this habit. CAP-1070 maintained the same response to diseases as the original cultivar. In trials carried out in several states of Brazil, yield was lower, similar or greater than ''Carioca'' depending on conditions. The short flowering period of CAP-1070, resulting from the bushy growth habit may reduce grain yields but under favourable circumstances, CAP-1070 may yield more than other varieties. CAP-1070 raised great interest among farmers visiting experimental fields of F.T. Pesquisa e Sementes, a private plant breeding firm at Ponta Grossa, Parana. Therefore, the firm decided to multiply the seeds and distribute them to farmers, who have now been cultivating CAP-1070 since 1986 between coffee rows. The CAP-1070 is the first induced bean mutant cultivated by farmers in Brazil. However, like the original cultivar ''Carioca'', CAP-1070 became susceptible to diseases. Therefore, we crossed the mutant and have obtained promising lines with bushy habits, disease resistance and higher yield. CAP-1070 is also used in cross-breeding programmes of Government research institutes in Brazil. Research was supported by IAEA under Research Contract No. 2195/SD, EMBRAPA, CNEN and CNPQ. (author)

  20. Simulation of short-term fluctuations in gamma exposure rate due to radioactive cloud released from nuclear power plant

    International Nuclear Information System (INIS)

    Ichikawa, Yoichi; Shikata, Hiroshi; Ishida, Kenji; Ohba, Tachimori.

    1981-01-01

    The measured γ-exposure rate around nuclear power plants is due mainly to natural causes and radioactive clouds emitted from the plants. An exposure calculation method based on puff model has been already proposed to identify the plant contributions and to estimate values in response to short-term fluctuations of meteorological condition and the release rate. However, the calculation method by this model consumes a lot of computer time, since the calculation requires a three-dimensional integration of the distribution of the concentration from each puff. Hence, we propose a simplified method using approximate polynominal equations and interpolations. The computer time needed for the calculation with the simplified method is reduced to 1/30 of that required by the previous method. The calculation results by simplified method are compared with those by the previous method and with the measured exposure rate less natural background. The results of two different methods are in good agreement. The calculated exposure rate is within the range from half to twice as much as the measured exposure rate less background. (author)

  1. Hormone assay

    International Nuclear Information System (INIS)

    Eisentraut, A.M.

    1977-01-01

    An improved radioimmunoassay is described for measuring total triiodothyronine or total thyroxine levels in a sample of serum containing free endogenous thyroid hormone and endogenous thyroid hormone bound to thyroid hormone binding protein. The thyroid hormone is released from the protein by adding hydrochloric acid to the serum. The pH of the separated thyroid hormone and thyroid hormone binding protein is raised in the absence of a blocking agent without interference from the endogenous protein. 125 I-labelled thyroid hormone and thyroid hormone antibodies are added to the mixture, allowing the labelled and unlabelled thyroid hormone and the thyroid hormone antibody to bind competitively. This results in free thyroid hormone being separated from antibody bound thyroid hormone and thus the unknown quantity of thyroid hormone may be determined. A thyroid hormone test assay kit is described for this radioimmunoassay. It provides a 'single tube' assay which does not require blocking agents for endogenous protein interference nor an external solid phase sorption step for the separation of bound and free hormone after the competitive binding step; it also requires a minimum number of manipulative steps. Examples of the assay are given to illustrate the reproducibility, linearity and specificity of the assay. (UK)

  2. Development and testing of species-specific ELISA assays to measure IFN-gamma and TNF-alpha in bottlenose dolphins (Tursiops truncatus)

    Science.gov (United States)

    Monitoring the immune status of cetaceans is important for a variety of health conditions. Assays to quantify cytokines, especially pro-inflammatory cytokines, could be employed, in addition to currently available diagnostic assays, to screen for alterations in the health status of an animal. Thou...

  3. 2015 In-Situ Gamma-Ray Assay of the West Cell Line in the 235-F Plutonium Fuel Form Facility

    Energy Technology Data Exchange (ETDEWEB)

    Brand, A. D. [Savannah River Site (SRS), Aiken, SC (United States). Savannah River National Lab. (SRNL); Aucott, T. J. [Savannah River Site (SRS), Aiken, SC (United States). Savannah River National Lab. (SRNL); DiPrete, D. P. [Savannah River Site (SRS), Aiken, SC (United States). Savannah River National Lab. (SRNL)

    2016-02-01

    In November and December 2015, scientists from SRNL took a series of in-situ gamma-ray measurements through the windows in front of Cells 6-9 on the west line of the PuFF facility using a shielded, 120% high-purity germanium detector. The detector efficiency was estimated using a combination of MCNP simulations and empirical measurements. Where possible, the distribution of the Pu-238 in the cells was determined using the Germanium Gamma-ray Imager (GeGI). This distribution was then fed into the MCNP model to quantify the Pu-238 in each cell. Data analysis was performed using three gamma rays emitted by Pu-238 (99.85 keV, 152.7 keV, and 766.4 keV) providing three independent estimates of the mass of Pu-238 holdup in each of the cells.

  4. Comparison of interferon-γ release assay to two cut-off points of tuberculin skin test to detect latent Mycobacterium tuberculosis infection in primary health care workers.

    Directory of Open Access Journals (Sweden)

    Fernanda Mattos de Souza

    Full Text Available An interferon-γ release assay, QuantiFERON-TB (QFT test, has been introduced an alternative test for the diagnosis of latent Mycobacterium tuberculosis infection (LTBI. Here, we compared the performance of QFT with tuberculin skin test (TST measured at two different cut-off points among primary health care work (HCW in Brazil.A cross-sectional study was carried out among HCWs in four Brazilian cities with a known history of high incidence of TB. Results of the QFT were compared to TST results based on both ≥5 mm and ≥10 mm as cut-off points.We enrolled 632 HCWs. When the cut-off value of ≥10 mm was used, agreement between QFT and TST was 69% (k = 0.31, and when the cut-off of ≥5 mm was chosen, the agreement was 57% (k = 0.22. We investigated possible factors of discordance of TST vs QFT. Compared to the TST-/QFT- group, risk factors for discordance in the TST+/QFT- group with TST cut-off of ≥5 mm included age between 41-45 years [OR = 2.70; CI 95%: 1.32-5.51] and 46-64 years [OR = 2.04; CI 95%: 1.05-3.93], BCG scar [OR = 2.72; CI 95%: 1.40-5.25], and having worked only in primary health care [OR = 2.30; CI 95%: 1.09-4.86]. On the other hand, for the cut-off of ≥10 mm, BCG scar [OR = 2.26; CI 95%: 1.03-4.91], being a household contact of a TB patient [OR = 1.72; CI 95%: 1.01-2.92] and having had a previous TST [OR = 1.66; CI 95%: 1.05-2.62], were significantly associated with the TST+/QFT- group. No statistically significant associations were found among the TST-/QFT+ discordant group with either TST cut-off value.Although we identified BCG vaccination to contribute to the discordance at both TST cut-off measures, the current Brazilian recommendation for the initiation of LTBI treatment, based on information gathered from medical history, TST, chest radiograph and physical examination, should not be changed.

  5. Comparison of interferon-γ release assay to two cut-off points of tuberculin skin test to detect latent Mycobacterium tuberculosis infection in primary health care workers.

    Science.gov (United States)

    de Souza, Fernanda Mattos; do Prado, Thiago Nascimento; Pinheiro, Jair dos Santos; Peres, Renata Lyrio; Lacerda, Thamy Carvalho; Loureiro, Rafaela Borge; Carvalho, Jose Américo; Fregona, Geisa; Dias, Elias Santos; Cosme, Lorrayne Beliqui; Rodrigues, Rodrigo Ribeiro; Riley, Lee Wood; Maciel, Ethel Leonor Noia

    2014-01-01

    An interferon-γ release assay, QuantiFERON-TB (QFT) test, has been introduced an alternative test for the diagnosis of latent Mycobacterium tuberculosis infection (LTBI). Here, we compared the performance of QFT with tuberculin skin test (TST) measured at two different cut-off points among primary health care work (HCW) in Brazil. A cross-sectional study was carried out among HCWs in four Brazilian cities with a known history of high incidence of TB. Results of the QFT were compared to TST results based on both ≥5 mm and ≥10 mm as cut-off points. We enrolled 632 HCWs. When the cut-off value of ≥10 mm was used, agreement between QFT and TST was 69% (k = 0.31), and when the cut-off of ≥5 mm was chosen, the agreement was 57% (k = 0.22). We investigated possible factors of discordance of TST vs QFT. Compared to the TST-/QFT- group, risk factors for discordance in the TST+/QFT- group with TST cut-off of ≥5 mm included age between 41-45 years [OR = 2.70; CI 95%: 1.32-5.51] and 46-64 years [OR = 2.04; CI 95%: 1.05-3.93], BCG scar [OR = 2.72; CI 95%: 1.40-5.25], and having worked only in primary health care [OR = 2.30; CI 95%: 1.09-4.86]. On the other hand, for the cut-off of ≥10 mm, BCG scar [OR = 2.26; CI 95%: 1.03-4.91], being a household contact of a TB patient [OR = 1.72; CI 95%: 1.01-2.92] and having had a previous TST [OR = 1.66; CI 95%: 1.05-2.62], were significantly associated with the TST+/QFT- group. No statistically significant associations were found among the TST-/QFT+ discordant group with either TST cut-off value. Although we identified BCG vaccination to contribute to the discordance at both TST cut-off measures, the current Brazilian recommendation for the initiation of LTBI treatment, based on information gathered from medical history, TST, chest radiograph and physical examination, should not be changed.

  6. Tuberculin skin test and interferon-gamma release assay values are associated with antimicrobial peptides expression in  polymorphonuclear cells during latent tuberculous infection

    Directory of Open Access Journals (Sweden)

    Julio E Castañeda-Delgado

    2014-06-01

    Full Text Available It has been reported that patients with progressive tuberculosis (TB express abundant amounts of the antimicrobial peptides (AMPs cathelicidin (LL-37 and human neutrophil peptide-1 (HNP-1 in circulating cells, whereas latent TB infected donors showed no differences when compared with purified protein derivative (PPD and QuantiFERON®-TB Gold (QFT-healthy individuals. The aim of this study was to determine whether LL-37 and HNP-1 production correlates with higher tuberculin skin test (TST and QFT values in TB household contacts. Twenty-six TB household contact individuals between 26-58 years old TST and QFT positive with at last two years of latent TB infection were recruited. AMPs production by polymorphonuclear cells was determined by flow cytometry and correlation between TST and QFT values was analysed. Our results showed that there is a positive correlation between levels of HNP-1 and LL-37 production with reactivity to TST and/or QFT levels. This preliminary study suggests the potential use of the expression levels of these peptides as biomarkers for progression in latent infected individuals.

  7. Preliminary Study of the Efficacy of Using Nuclear Resonance Fluorescence with Quasi-Monoenergetic Gamma-Ray Sources for Nuclear Safeguards Assay

    Energy Technology Data Exchange (ETDEWEB)

    Johnson, M S; McNabb, D P; Hall, J M; Gonzalez, J J

    2011-02-17

    We have studied the efficacy of using nuclear resonance fluorescence (NRF)-based techniques to assay spent nuclear fuel for Pu content using quasi-monoenergetic sources. We have developed two techniques to precisely determine the Pu content in a fuel rod/pin. One of our approaches is virtually free of systematic uncertainties. Using analytical models, we have determined the amount of time required to measure the Pu content in spent nuclear fuel rods and spent fuel assemblies to within 1% precision. We note that Pu content can be determined in a fuel assembly about as fast as in a single fuel pin. The performance of NRF-based assay techniques with improved photon sources, which are currently under development, will also estimated. For follow-on research we propose to: (1) Construct research prototype detection systems for both of the NRF-based assay systems proposed in this paper and measure their calibration curves; (2) Determine the systematic errors associated with both assay methods, explore ways to reduce the errors and fold the results into future performance calculations; (3) Develop an algorithm to assay a fuel assembly; (4) Perform validation measurements using a single pin and scaled assemblies; (5) Research and develop current-mode detection and/or threshold detection techniques to improve assay times; (6) Characterize the flux of newly constructed sources and fold the results into the calculations presented here to determine the feasibility of a variety of proposed sources; and (7) Collaborate with others in the safeguards community to build a prototype system and perform an NRF-based assay demonstration on spent fuel.

  8. Release patterns of pregnancy-associated plasma protein A in patients with acute coronary syndromes assessed by an optimized monoclonal antibody assay

    DEFF Research Database (Denmark)

    Schoos, Mikkel; Iversen, Kasper; Teisner, Ane

    2008-01-01

    Objective. Pregnancy-associated plasma protein A (PAPP-A) is expressed in eroded and ruptured atheromatous plaques, and circulating levels are elevated in acute coronary syndromes (ACS). Our objective was to investigate release patterns of PAPP-A in ACS and whether they differ among different typ...

  9. Characterization of legacy low level waste at the Svafo facility using gamma non-destructive assay and X-ray non-destructive examination techniques - 59289

    International Nuclear Information System (INIS)

    Halliwell, Stephen; Mottershead, Gary; Ekenborg, Fredrik

    2012-01-01

    Document available in abstract form only. Full text of publication follows: Over 7000 drums containing legacy, low level radioactive waste are stored at four SVAFO facilities on the Studsvik site which is located near Nykoeping, Sweden. The vast majority of the waste drums (>6000) were produced between 1969 and 1979. The remainder were produced from 1980 onwards. Characterization of the waste was achieved using a combination of non-destructive techniques via mobile equipment located in the AU building at the Studsvik site. Each drum was weighed and a dose rate measurement was recorded. Gamma spectroscopy was used to measure and estimate radionuclide content. Real time xray examination was performed to identify such prohibited items as free liquids. (authors)

  10. Specificity of the Tuberculin Skin Test and the T-SPOT."TB" Assay among Students in a Low-Tuberculosis Incidence Setting

    Science.gov (United States)

    Talbot, Elizabeth A.; Harland, Dawn; Wieland-Alter, Wendy; Burrer, Sherry; Adams, Lisa V.

    2012-01-01

    Objective: Interferon-[gamma] release assays (IGRAs) are an important tool for detecting latent "Mycobacterium tuberculosis" infection (LTBI). Insufficient data exist about IGRA specificity in college health centers, most of which screen students for LTBI using the tuberculin skin test (TST). Participants: Students at a low-TB incidence college…

  11. Improvement of non-destructive fissile mass assays in α low-level waste drums: A matrix correction method based on neutron capture gamma-rays and a neutron generator

    Science.gov (United States)

    Jallu, F.; Loche, F.

    2008-08-01

    Within the framework of radioactive waste control, non-destructive assay (NDA) methods may be employed. The active neutron interrogation (ANI) method is now well-known and effective in quantifying low α-activity fissile masses (mainly 235U, 239Pu, 241Pu) with low densities, i.e. less than about 0.4, in radioactive waste drums of volumes up to 200 l. The PROMpt Epithermal and THErmal interrogation Experiment (PROMETHEE [F. Jallu, A. Mariani, C. Passard, A.-C. Raoux, H. Toubon, Alpha low level waste control: improvement of the PROMETHEE 6 assay system performances. Nucl. Technol. 153 (January) (2006); C. Passard, A. Mariani, F. Jallu, J. Romeyer-Dherber, H. Recroix, M. Rodriguez, J. Loridon, C. Denis, PROMETHEE: an alpha low level waste assay system using passive and active neutron measurement methods. Nucl. Technol. 140 (December) (2002) 303-314]) based on ANI has been under development since 1996 to reach the incinerating α low level waste (LLW) criterion of about 50 Bq[α] per gram of crude waste (≈50 μg Pu) in 118 l drums on the date the drums are conditioned. Difficulties arise when dealing with matrices containing neutron energy moderators such as H and neutron absorbents such as Cl. These components may have a great influence on the fissile mass deduced from the neutron signal measured by ANI. For example, the calibration coefficient measured in a 118 l drum containing a cellulose matrix (density d = 0.144 g cm -3) may be 50 times higher than that obtained in a poly-vinyl-chloride matrix ( d = 0.253 g cm -3). Without any information on the matrix, the fissile mass is often overestimated due to safety procedures and by considering the most disadvantageous calibration coefficient corresponding to the most absorbing and moderating calibration matrix. The work discussed in this paper was performed at the CEA Nuclear Measurement Laboratory in France. It concerns the development of a matrix effect correction method, which consists in identifying and quantifying

  12. Improvement of non-destructive fissile mass assays in α low-level waste drums: A matrix correction method based on neutron capture gamma-rays and a neutron generator

    International Nuclear Information System (INIS)

    Jallu, F.; Loche, F.

    2008-01-01

    Within the framework of radioactive waste control, non-destructive assay (NDA) methods may be employed. The active neutron interrogation (ANI) method is now well-known and effective in quantifying low α-activity fissile masses (mainly 235 U, 239 Pu, 241 Pu) with low densities, i.e. less than about 0.4, in radioactive waste drums of volumes up to 200 l. The PROMpt Epithermal and THErmal interrogation Experiment (PROMETHEE [F. Jallu, A. Mariani, C. Passard, A.-C. Raoux, H. Toubon, Alpha low level waste control: improvement of the PROMETHEE 6 assay system performances. Nucl. Technol. 153 (January) (2006); C. Passard, A. Mariani, F. Jallu, J. Romeyer-Dherber, H. Recroix, M. Rodriguez, J. Loridon, C. Denis, PROMETHEE: an alpha low level waste assay system using passive and active neutron measurement methods. Nucl. Technol. 140 (December) (2002) 303-314]) based on ANI has been under development since 1996 to reach the incinerating α low level waste (LLW) criterion of about 50 Bq[α] per gram of crude waste (∼50 μg Pu) in 118 l drums on the date the drums are conditioned. Difficulties arise when dealing with matrices containing neutron energy moderators such as H and neutron absorbents such as Cl. These components may have a great influence on the fissile mass deduced from the neutron signal measured by ANI. For example, the calibration coefficient measured in a 118 l drum containing a cellulose matrix (density d = 0.144 g cm -3 ) may be 50 times higher than that obtained in a poly-vinyl-chloride matrix (d = 0.253 g cm -3 ). Without any information on the matrix, the fissile mass is often overestimated due to safety procedures and by considering the most disadvantageous calibration coefficient corresponding to the most absorbing and moderating calibration matrix. The work discussed in this paper was performed at the CEA Nuclear Measurement Laboratory in France. It concerns the development of a matrix effect correction method, which consists in identifying and

  13. Improvement of non-destructive fissile mass assays in {alpha} low-level waste drums: A matrix correction method based on neutron capture gamma-rays and a neutron generator

    Energy Technology Data Exchange (ETDEWEB)

    Jallu, F. [Commissariat a l' Energie Atomique, CEA, DEN, Nuclear Measurement Laboratory, Bat. 224, 13108 Saint Paul lez Durance (France)], E-mail: fanny.jallu@cea.fr; Loche, F. [Commissariat a l' Energie Atomique, CEA, DEN, Nuclear Measurement Laboratory, Bat. 224, 13108 Saint Paul lez Durance (France)

    2008-08-15

    Within the framework of radioactive waste control, non-destructive assay (NDA) methods may be employed. The active neutron interrogation (ANI) method is now well-known and effective in quantifying low {alpha}-activity fissile masses (mainly {sup 235}U, {sup 239}Pu, {sup 241}Pu) with low densities, i.e. less than about 0.4, in radioactive waste drums of volumes up to 200 l. The PROMpt Epithermal and THErmal interrogation Experiment (PROMETHEE [F. Jallu, A. Mariani, C. Passard, A.-C. Raoux, H. Toubon, Alpha low level waste control: improvement of the PROMETHEE 6 assay system performances. Nucl. Technol. 153 (January) (2006); C. Passard, A. Mariani, F. Jallu, J. Romeyer-Dherber, H. Recroix, M. Rodriguez, J. Loridon, C. Denis, PROMETHEE: an alpha low level waste assay system using passive and active neutron measurement methods. Nucl. Technol. 140 (December) (2002) 303-314]) based on ANI has been under development since 1996 to reach the incinerating {alpha} low level waste (LLW) criterion of about 50 Bq[{alpha}] per gram of crude waste ({approx}50 {mu}g Pu) in 118 l drums on the date the drums are conditioned. Difficulties arise when dealing with matrices containing neutron energy moderators such as H and neutron absorbents such as Cl. These components may have a great influence on the fissile mass deduced from the neutron signal measured by ANI. For example, the calibration coefficient measured in a 118 l drum containing a cellulose matrix (density d = 0.144 g cm{sup -3}) may be 50 times higher than that obtained in a poly-vinyl-chloride matrix (d = 0.253 g cm{sup -3}). Without any information on the matrix, the fissile mass is often overestimated due to safety procedures and by considering the most disadvantageous calibration coefficient corresponding to the most absorbing and moderating calibration matrix. The work discussed in this paper was performed at the CEA Nuclear Measurement Laboratory in France. It concerns the development of a matrix effect correction

  14. Human gamma interferon production by cytotoxic T lymphocytes sensitized during hepatitis A virus infection

    International Nuclear Information System (INIS)

    Maier, K.; Gabriel, P.; Koscielniak, E.; Stierhof, Y.D.; Wiedmann, K.H.; Flehmig, B.; Vallbracht, A.

    1988-01-01

    The production of interferon (IFN) during a chromium-51 release assay with hepatitis A virus (HAV)-infected fibroblasts and autologous peripheral blood lymphocytes from patients with acute HAV infection was studied to determine whether IFN plays a role in immunopathogenesis of hepatitis A infection in humans. Skin fibroblasts of eight patients after acute HAV infection and from two control persons without history of current of past HAV infection were infected with HAV. Peripheral blood lymphocytes were collected at different times after the onset of icterus and tested in a chromium-51 release assay against autologous HAV-infected skin fibroblasts for their cytolytic and IFN-producing activity. The IFN produced during the assay was characterized and found to have the properties of human gamma IFN. Cytotoxicity and gamma IFN release were virus specific. The cell types responsible for both functions were characterized and found to be in the HLA-dependent T8 + lymphocyte subset. Considering that gamma IFN has an antiviral effect on persistent HAV infection in vitro and that it probably accounts for stimulation of HLA class I antigen expression on hepatocytes, these experimental results presented here demonstrate that human gamma IFN produced by HAV-specific T cells may participate in pathogenesis of hepatitis A infection in humans

  15. Strong interferon-gamma mediated cellular immunity to scrub typhus demonstrated using a novel whole cell antigen ELISpot assay in rhesus macaques and humans.

    Directory of Open Access Journals (Sweden)

    Manutsanun Sumonwiriya

    2017-09-01

    Full Text Available Scrub typhus is a febrile infection caused by the obligate intracellular bacterium Orientia tsutsugamushi, which causes significant morbidity and mortality across the Asia-Pacific region. The control of this vector-borne disease is challenging due to humans being dead-end hosts, vertical maintenance of the pathogen in the vector itself, and a potentially large rodent reservoir of unclear significance, coupled with a lack of accurate diagnostic tests. Development of an effective vaccine is highly desirable. This however requires better characterization of the natural immune response of this neglected but important disease. Here we implement a novel IFN-γ ELISpot assay as a tool for studying O. tsutsugamushi induced cellular immune responses in an experimental scrub typhus rhesus macaque model and human populations. Whole cell antigen for O. tsutsugamushi (OT-WCA was prepared by heat inactivation of Karp-strain bacteria. Rhesus macaques were infected intradermally with O. tsutsugamushi. Freshly isolated peripheral blood mononuclear cells (PBMC from infected (n = 10 and uninfected animals (n = 5 were stimulated with OT-WCA, and IFN-γ secreting cells quantitated by ELISpot assay at five time points over 28 days. PBMC were then assayed from people in a scrub typhus-endemic region of Thailand (n = 105 and responses compared to those from a partially exposed population in a non-endemic region (n = 14, and to a naïve population in UK (n = 12. Mean results at Day 0 prior to O. tsutsugamushi infection were 12 (95% CI 0-25 and 15 (2-27 spot-forming cells (SFC/106 PBMC for infected and control macaques respectively. Strong O. tsutsugamushi-specific IFN-γ responses were seen post infection, with ELISpot responses 20-fold higher than baseline at Day 7 (mean 235, 95% CI 200-270 SFC/106 PBMC, 105-fold higher at Day 14 (mean 1261, 95% CI 1,097-1,425 SFC/106 PBMC, 125-fold higher at Day 21 (mean 1,498, 95% CI 1,496-1,500 SFC/106 PBMC and 118-fold higher at

  16. Strong interferon-gamma mediated cellular immunity to scrub typhus demonstrated using a novel whole cell antigen ELISpot assay in rhesus macaques and humans.

    Science.gov (United States)

    Sumonwiriya, Manutsanun; Paris, Daniel H; Sunyakumthorn, Piyanate; Anantatat, Tippawan; Jenjaroen, Kemajittra; Chumseng, Suchintana; Im-Erbsin, Rawiwan; Tanganuchitcharnchai, Ampai; Jintaworn, Suthatip; Blacksell, Stuart D; Chowdhury, Fazle R; Kronsteiner, Barbara; Teparrukkul, Prapit; Burke, Robin L; Lombardini, Eric D; Richards, Allen L; Mason, Carl J; Jones, James W; Day, Nicholas P J; Dunachie, Susanna J

    2017-09-01

    Scrub typhus is a febrile infection caused by the obligate intracellular bacterium Orientia tsutsugamushi, which causes significant morbidity and mortality across the Asia-Pacific region. The control of this vector-borne disease is challenging due to humans being dead-end hosts, vertical maintenance of the pathogen in the vector itself, and a potentially large rodent reservoir of unclear significance, coupled with a lack of accurate diagnostic tests. Development of an effective vaccine is highly desirable. This however requires better characterization of the natural immune response of this neglected but important disease. Here we implement a novel IFN-γ ELISpot assay as a tool for studying O. tsutsugamushi induced cellular immune responses in an experimental scrub typhus rhesus macaque model and human populations. Whole cell antigen for O. tsutsugamushi (OT-WCA) was prepared by heat inactivation of Karp-strain bacteria. Rhesus macaques were infected intradermally with O. tsutsugamushi. Freshly isolated peripheral blood mononuclear cells (PBMC) from infected (n = 10) and uninfected animals (n = 5) were stimulated with OT-WCA, and IFN-γ secreting cells quantitated by ELISpot assay at five time points over 28 days. PBMC were then assayed from people in a scrub typhus-endemic region of Thailand (n = 105) and responses compared to those from a partially exposed population in a non-endemic region (n = 14), and to a naïve population in UK (n = 12). Mean results at Day 0 prior to O. tsutsugamushi infection were 12 (95% CI 0-25) and 15 (2-27) spot-forming cells (SFC)/106 PBMC for infected and control macaques respectively. Strong O. tsutsugamushi-specific IFN-γ responses were seen post infection, with ELISpot responses 20-fold higher than baseline at Day 7 (mean 235, 95% CI 200-270 SFC/106 PBMC), 105-fold higher at Day 14 (mean 1261, 95% CI 1,097-1,425 SFC/106 PBMC), 125-fold higher at Day 21 (mean 1,498, 95% CI 1,496-1,500 SFC/106 PBMC) and 118-fold higher at Day 28

  17. Role of polymorphic Fc receptor Fc gammaRIIa in cytokine release and adverse effects of murine IgG1 anti-CD3/T cell receptor antibody (WT31).

    Science.gov (United States)

    Tax, W J; Tamboer, W P; Jacobs, C W; Frenken, L A; Koene, R A

    1997-01-15

    Anti-CD3 monoclonal antibody (mAb) OKT3 is immunosuppressive, but causes severe adverse effects during the first administration ("first-dose reaction"). These adverse effects are presumably caused by cytokine release that results from T-cell activation. In vitro, T-cell activation by anti-CD3 mAb requires interaction with monocyte Fc receptors. The Fc receptor for murine IgG1, Fc gammaRIIa, is polymorphic. In some individuals, murine IgG1 anti-CD3 mAb causes T-cell proliferation and cytokine release in vitro (high responders [HR]), whereas in individuals with the low-responder (LR) phenotype it does not. We have now investigated the role of this Fc gammaRIIa polymorphism in the release of cytokines in vivo and the occurrence of adverse effects after the administration of WT31, a murine IgG1 anti-CD3/T cell receptor mAb. WT31 caused an increase of plasma tumor necrosis factor-alpha in all four HR patients and none of the five LR patients. In all HR patients except one, plasma gamma-interferon and interleukin 6 also increased, and a first-dose response was observed, whereas no cytokine release or adverse effects occurred in any of the LR patients. WT31 caused lymphopenia in all HR and none of the LR patients. FACS analysis demonstrated that in HR patients, after the initial disappearance of CD3+ cells from peripheral blood, modulation of CD3 occurred, whereas in LR patients a high degree of coating of the lymphocytes was observed. Surprisingly, WT31 also induced a marked granulocytopenia, as well as a decrease of thrombocytes, in three of the four HR patients (and in none of the LR patients). These data provide direct clinical evidence that Fc receptor interaction determines the release of cytokines and the occurrence of adverse effects after administration of anti-CD3/T cell receptor mAb. Furthermore, these data suggest that tumor necrosis factor-alpha by itself is not sufficient to induce the first-dose reaction.

  18. Evaluation of immune responses in HIV infected patients with pleural tuberculosis by the QuantiFERON® TB-Gold interferon-gamma assay

    Directory of Open Access Journals (Sweden)

    Lekabe Jacob M

    2008-03-01

    Full Text Available Abstract Background Diagnosis of tuberculous (TB pleuritis is difficult and better diagnostic tools are needed. New blood based interferon-gamma (IFN-γ tests are promising, but sensitivity could be low in HIV positive patients. The IFN-γ tests have not yet been validated for use in pleural fluid, a compartment with higher level of immune activation than in blood. Methods The QuantiFERON TB®-Gold (QFT-TB test was analysed in blood and pleural fluid from 34 patients presenting with clinically suspected pleural TB. Clinical data, HIV status and CD4 cell counts were recorded. Adenosine deaminase activity (ADA analysis and TB culture were performed on pleural fluid. Results The patients were categorised as 'confirmed TB' (n = 12, 'probable TB' (n = 16 and 'non-TB' pleuritis (n = 6 based on TB culture results and clinical and biochemical criteria. The majority of the TB patients were HIV infected (82%. The QFT-TB in pleural fluid was positive in 27% and 56% of the 'confirmed TB' and 'probable TB' cases, respectively, whereas the corresponding sensitivities in blood were 58% and 83%. Indeterminate results in blood (25% were caused by low phytohemagglutinin (PHA = positive control IFN-γ responses, significantly lower in the TB patients as compared to the 'non-TB' cases (p = 0.02. Blood PHA responses correlated with CD4 cell count (r = 0.600, p = 0.028. In contrast, in pleural fluid indeterminate results (52% were caused by high Nil (negative control IFN-γ responses in both TB groups. Still, the Nil IFN-γ responses were lower than the TB antigen responses (p Conclusion The QFT-TB test in blood could contribute to the diagnosis of TB pleuritis in the HIV positive population. Still, the number of inconclusive results is too high to recommend the commercial QFT-TB test for routine use in pleural fluid in a TB/HIV endemic resource-limited setting.

  19. Application of nuclear activation analysis (NAA) and low-level gamma counting to determine the radionuclide and trace element pollutant releases from coal-fired power plants in Vietnam

    International Nuclear Information System (INIS)

    Vanduong, P.; Thanh, V.T.; Dien, P.Q.; Binh, N.T.

    1995-01-01

    Results are reported of the application of NAA using research reactors TRIGA II in Dalat, Vietnam, and Vienna, Austria (with pyrolysis separation for Hg, Se, and As before irradiation), to determine As, Cd, Cu, Hg, Ni, Co, Pb, Sn and Zn. Low-level gamma counting was used to measure Ra-226, Th-228 and K-40, released from coal-fired power plants in Vietnam. Results showed that: (1) the content of the air pollutants in the vicinity of the operating power plants (in 1991, the Phalai plant produced 1700 million kWh, and the Ninhbinh plant 100 million kWh) depends on the coal combustion which is used for their applied operation technology, both plants used Quangninh anthracite as fuel. The content of trace elements pollutants (TEP) in the environment of the Ninhbinh plant is higher than in the Phalai plant. (2) In the vicinity of both plants, rain water is highly polluted by trace elements such as As, Cu, Pb, Hg, Ni, Co, Cd, Se, U, Th and sulphuric acid. Therefore, this kind of water is not acceptable for human consumption. (3) The algae growing in the waterfield in the vicinity of the power plants can be used to monitor TEP. Four NAA methods, in combination with low-level gamma counting and AAS, can be successfully used to monitor TEP released from power plants

  20. Effect of ouabain on the gamma-[3H]aminobutyric acid uptake and release in the absence of Ca(+)+ and K(+)-depolarization

    International Nuclear Information System (INIS)

    Santos, M.S.; Goncalves, P.P.; Carvalho, A.P.

    1990-01-01

    The effect of ouabain on the uptake of tritiated [ 3 H]GABA and on its release in the absence of Ca(+)+ was studied in brain cortex synaptosomes. Ouabain, in the absence of Ca(+)+ and K(+)-depolarization, induces the release of [ 3 H]GABA with half-maximal effect occurring at a concentration of about 7 X 10(-6) M. Parallel measurements of the effects of ouabain on the [ 3 H]GABA uptake and the Na+,K(+)-adenosine triphosphatase activity show that ouabain inhibits both mechanisms and that the half-maximal effect also occurs at about the same ouabain concentration. Although [ 3 H]GABA release is stimulated by ouabain, it appears that the inhibition of [ 3 H]GABA uptake is due to a direct effect on the uptake mechanism, inasmuch as the initial velocity of the process is inhibited by ouabain. Ouabain requires extracellular Na+ for [ 3 H]GABA release and for membrane depolarization and, in the absence of Na+, ouabain does not cause either [ 3 H]GABA release or membrane depolarization. No significant changes in the Na+ gradients occur under conditions which permit release of [ 3 H]GABA, but the Na+,K(+)-adenosine triphosphatase activity is inhibited, which may be responsible for membrane depolarization, which in turn may cause [ 3 H]GABA release or inhibit its uptake

  1. Lactobacillus GG has in vitro effects on enhanced interleukin-10 and interferon-gamma release of mononuclear cells but no in vivo effects in supplemented mothers and their neonates.

    Science.gov (United States)

    Kopp, M V; Goldstein, M; Dietschek, A; Sofke, J; Heinzmann, A; Urbanek, R

    2008-04-01

    The value of probiotics for primary prevention is controversial. Moreover, only little is known about the underlying immunological mechanisms of action. Therefore, we assessed the proliferative response and cytokine release in cultures of isolated mononuclear cells from pregnant women and their neonates supplemented with Lactobacillus GG (LGG) or placebo. In a double-blind, placebo-controlled prospective trial, pregnant women with at least one first-degree relative or a partner with an atopic disease were randomly assigned to receive either the probiotic LGG (ATCC 53103; 5 x 10(9) colony-forming units LGG twice daily) or placebo 4-6 weeks before expected delivery, followed by a post-natal period of 6 months. Cord blood mononuclear cells (CBMC) and peripheral blood mononuclear cells (PBMC) of the corresponding mother were isolated from cord blood and peripheral blood (n=68). The proliferative response of CBMC and PBMC was expressed as the stimulation index (SI), which was calculated according to the ratio between the mean counts per minute (c.p.m.) values measured in the wells with stimulated cells and the mean c.p.m. values measured in the wells with unstimulated cells. Additionally, the cytokines IFN-gamma, IL-10 and IL-13 in the cell culture supernatants were measured using the ELISA technique. No difference was observed between the LGG-supplemented group and the placebo group in terms of the proliferative capacity of maternal or neonatal cord blood cells in response to IL-2, beta-lactoglobulin or LGG. In vitro stimulation with LGG resulted in significantly enhanced release of IL-10 and IFN-gamma, compared with cytokine release in unstimulated controls. However, this phenomenon was observed in supernatants of maternal and neonatal MC in both groups, independent of prior supplementation with LGG. LGG has in vitro effects on enhanced IL-10 and IFN-gamma release of mononuclear cells. However, supplementation with LGG during pregnancy did not alter the proliferative

  2. An Enzyme-Linked Immunosorbent Spot Assay Measuring Borrelia burgdorferi B31-Specific Interferon Gamma-Secreting T Cells Cannot Discriminate Active Lyme Neuroborreliosis from Past Lyme Borreliosis: a Prospective Study in the Netherlands.

    Science.gov (United States)

    van Gorkom, T; Sankatsing, S U C; Voet, W; Ismail, D M; Muilwijk, R H; Salomons, M; Vlaminckx, B J M; Bossink, A W J; Notermans, D W; Bouwman, J J M; Kremer, K; Thijsen, S F T

    2018-04-01

    Two-tier serology testing is most frequently used for the diagnosis of Lyme borreliosis (LB); however, a positive result is no proof of active disease. To establish a diagnosis of active LB, better diagnostics are needed. Tests investigating the cellular immune system are available, but studies evaluating the utility of these tests on well-defined patient populations are lacking. Therefore, we investigated the utility of an enzyme-linked immunosorbent spot (ELISpot) assay to diagnose active Lyme neuroborreliosis. Peripheral blood mononuclear cells (PBMCs) of various study groups were stimulated by using Borrelia burgdorferi strain B31 and various recombinant antigens, and subsequently, the number of Borrelia -specific interferon gamma (IFN-γ)-secreting T cells was measured. We included 33 active and 37 treated Lyme neuroborreliosis patients, 28 healthy individuals treated for an early manifestation of LB in the past, and 145 untreated healthy individuals. The median numbers of B. burgdorferi B31-specific IFN-γ-secreting T cells/2.5 × 10 5 PBMCs did not differ between active Lyme neuroborreliosis patients (6.0; interquartile range [IQR], 0.5 to 14.0), treated Lyme neuroborreliosis patients (4.5; IQR, 2.0 to 18.6), and treated healthy individuals (7.4; IQR, 2.3 to 14.9) ( P = 1.000); however, the median number of B. burgdorferi B31-specific IFN-γ-secreting T cells/2.5 × 10 5 PBMCs among untreated healthy individuals was lower (2.0; IQR, 0.5 to 3.9) ( P ≤ 0.016). We conclude that the Borrelia ELISpot assay, measuring the number of B. burgdorferi B31-specific IFN-γ-secreting T cells/2.5 × 10 5 PBMCs, correlates with exposure to the Borrelia bacterium but cannot be used for the diagnosis of active Lyme neuroborreliosis. Copyright © 2018 van Gorkom et al.

  3. A strategy for the unrestricted release of metallic scrap from decommissioned nuclear facilities, integrating quality planning with the effective use of non-destructive assay instrumentation

    International Nuclear Information System (INIS)

    Gunn, R.; Troughten, N.; Warran, C.

    2000-01-01

    The key component of any release operation is its quality plan. This plan is a step by step procedure which describes all the actions which are required during the entire process and also the information required at every stage of the process. Once drafted the quality plan will enable operators to determine at what stages it is necessary to measure the parameters required to allow the process to progress. The objective of the radiometric system is to provide the auditable proof that material has been surveyed, the record of the survey and the evidence that the system was operating within its design parameters during the survey. Typical radiometric instruments which have been deployed to provide the information requirements of the quality plan are described in this paper. These include the IonSens TM Conveyor, conveyorized survey monitor used to provide high throughout clearance surveys of removed metallic scrap. The IonSens TM Pipe, cut pipe monitor is used to survey interiors and exteriors of long lengths of removed pipe-work. The IonSens TM 208 large Item monitor is used to survey removed pieces of vessels and ductwork which may have convoluted shapes and finally the DrumScan TM system is used to survey 200 litre drums containing cut up pieces of metal. (author)

  4. A radioreceptor assay of luteinizing hormone-releasing hormone receptor and characterization of LHRH binding to pituitary receptors in Shao duck

    International Nuclear Information System (INIS)

    Yang Peixin; Wu Meiwen; Chen Ziyuan

    2000-01-01

    The properties of Shao duck pituitary luteinizing hormone-releasing hormone (LHRH) receptors were analyzed in pituitary membrane preparation and isolated pituitary cells prepared by enzymatic dispersion with collagenase and trypsin, by using a super-agonist analog of (D-Lys 6 ) LHRH. High binding of 125 I-(D-Lys 6 ) LHRH to 10 6 cultured cells of Shao duck was observed after a 90 minute incubation at 4 degree C, while binding was significantly reduced after a 24h incubation. Binding of the radioligand was a function of tissue concentration of Shao duck pituitary membrane preparation, with a positive correlation over the range of 1-2 pituitary per-tube. Specific binding for 125 I-(D-Lys 6 ) LHRH increased with the increase in the amount of 125 I-(D-Lys 6 ) LHRH. The Scatchard analysis of data revealed a linear relationship between the amount of specific binding and the ratio of specific binding to free 1 '2 5 I(D-Lys 6 )LHRH, indicating a single class of high affinity sites. Equilibrium dissociation constant (Kd) was 0.34 nM in pituitary membrane preparation and 0.43 nM in isolated pituitary cells. Both Kd values were near and the maximum binding capacity (B max ) was great in isolated cells, suggesting no significant loss of the LHRH receptor population caused by the enzymatic procedure employed for cell dispersion in the present study. Addition of 9D-Lys 6 ) LHRH displaced bound 125 I-(D-Lys 6 ) LHRH. These results demonstrated the presence and provided characterization of LHRH receptors in Shao duck pituitary

  5. Radiation chemistry of DNA. II. Strand breaks and sugar release by. gamma. -irradiation of DNA in aqueous solution. The effect of oxygen

    Energy Technology Data Exchange (ETDEWEB)

    Dizdaroglu, M; Schulte-Frohlinde, D; von Sonntag, C [Max-Planck-Institut fuer Kohlenforschung, Muelheim an der Ruhr (F.R. Germany). Abt. fuer Strahlenchemie

    1975-11-01

    From ..gamma..-irradiated oxygenated aqueous solutions of DNA, 2-deoxy-tetrodialdose (1) and 2-deoxy-pentos-4-ulose (2) have been isolated as free sugars. The formation of 1 indicates that in the presence of oxygen the DNA strand is not only broken by mere phosphate ester cleavage but also by C-C-bond rupture in the sugar moiety. Such a process has not been encountered in deoxygenated solutions so far. The mechanism for the formation of 1 is discussed.

  6. Mechanism and kinetics of the loss of poorly soluble drugs from liposomal carriers studied by a novel flow field-flow fractionation-based drug release-/transfer-assay.

    Science.gov (United States)

    Hinna, Askell Hvid; Hupfeld, Stefan; Kuntsche, Judith; Bauer-Brandl, Annette; Brandl, Martin

    2016-06-28

    Liposomes represent a versatile drug formulation approach e.g. for improving the water-solubility of poorly soluble drugs but also to achieve drug targeting and controlled release. For the latter applications it is essential that the drug remains associated with the liposomal carrier during transit in the vascular bed. A range of in vitro test methods has been suggested over the years for prediction of the release of drug from liposomal carriers. The majority of these fail to give a realistic prediction for poorly water-soluble drugs due to the intrinsic tendency of such compounds to remain associated with liposome bilayers even upon extensive dilution. Upon i.v. injection, in contrast, rapid drug loss often occurs due to drug transfer from the liposomal carriers to endogenous lipophilic sinks such as lipoproteins, plasma proteins or membranes of red blood cells and endothelial cells. Here we report on the application of a recently introduced in vitro predictive drug transfer assay based on incubation of the liposomal drug carrier with large multilamellar liposomes, the latter serving as a biomimetic model sink, using flow field-flow fractionation as a tool to separate the two types of liposomes. By quantifying the amount of drug remaining associated with the liposomal drug carrier as well as that transferred to the acceptor liposomes at distinct times of incubation, both the kinetics of drug transfer and release to the water phase could be established for the model drug p-THPP (5,10,15,20-tetrakis(4-hydroxyphenyl)21H,23H-porphine). p-THPP is structurally similar to temoporfin, a photosensitizer which is under clinical evaluation in a liposomal formulation. Mechanistic insights were gained by varying the donor-to-acceptor lipid mass ratio, size and lamellarity of the liposomes. Drug transfer kinetics from one liposome to another was found rate determining as compared to redistribution from the outermost to the inner concentric bilayers, such that the overall

  7. Inhibition of Mitochondrial Cytochrome c Release and Suppression of Caspases by Gamma-Tocotrienol Prevent Apoptosis and Delay Aging in Stress-Induced Premature Senescence of Skin Fibroblasts

    Directory of Open Access Journals (Sweden)

    Suzana Makpol

    2012-01-01

    Full Text Available In this study, we determined the molecular mechanism of γ-tocotrienol (GTT in preventing cellular aging by focusing on its anti-apoptotic effect in stress-induced premature senescence (SIPS model of human diploid fibroblasts (HDFs. Results obtained showed that SIPS exhibited senescent-phenotypic characteristic, increased expression of senescence-associated β-galactosidase (SA β-gal and promoted G0/G1 cell cycle arrest accompanied by shortening of telomere length with decreased telomerase activity. Both SIPS and senescent HDFs shared similar apoptotic changes such as increased Annexin V-FITC positive cells, increased cytochrome c release and increased activation of caspase-9 and caspase-3 (P<0.05. GTT treatment resulted in a significant reduction of Annexin V-FITC positive cells, inhibited cytochrome c release and decreased activation of caspase-9 and caspase-3 (P<0.05. Gene expression analysis showed that GTT treatment down regulated BAX mRNA, up-regulated BCL2A1 mRNA and decreased the ratio of Bax/Bcl-2 protein expression (P<0.05 in SIPS. These findings suggested that GTT inhibits apoptosis by modulating the upstream apoptosis cascade, causing the inhibition of cytochrome c release from the mitochondria with concomitant suppression of caspase-9 and caspase-3 activation. In conclusion, GTT delays cellular senescence of human diploid fibroblasts through the inhibition of intrinsic mitochondria-mediated pathway which involved the regulation of pro- and anti-apoptotic genes and proteins.

  8. Nondestructive assay methodologies in nuclear forensics analysis

    International Nuclear Information System (INIS)

    Tomar, B.S.

    2016-01-01

    In the present chapter, the nondestructive assay (NDA) methodologies used for analysis of nuclear materials as a part of nuclear forensic investigation have been described. These NDA methodologies are based on (i) measurement of passive gamma and neutrons emitted by the radioisotopes present in the nuclear materials, (ii) measurement of gamma rays and neutrons emitted after the active interrogation of the nuclear materials with a source of X-rays, gamma rays or neutrons

  9. Differential effect of gamma-irradiated and heat-treated lymphocytes on T cell activation, and interleukin-2 and interleukin-3 release in the human mixed lymphocyte reaction

    International Nuclear Information System (INIS)

    Loertscher, R.; Abbud-Filho, M.; Leichtman, A.B.; Ythier, A.A.; Williams, J.M.; Carpenter, C.B.; Strom, T.B.

    1987-01-01

    Heat-inactivated (45 degrees C/1 hr) lymphocytes selectively activate suppressor T cells in the mixed lymphocyte reaction (MLR), while no significant proliferation and cytotoxic T lymphocyte activation can be detected. It is not well understood why hyperthermic treatment abolishes the stimulatory capacity of lymphocytes since HLA-DR molecules remain detectable immediately following heat exposure. In order to further characterize the requirements for Ts activation we studied the effects of hyperthermic treatment on cellular protein and DNA synthesis and cell surface protein expression in proliferating T and B cells; interleukin (IL)-1, IL-2, and IL-3 release following allogeneic stimulation with heat treated cells (HMLR); and IL-2 receptor expression as an indicator of T cell activation in the HMLR. Hyperthermic treatment reduced cellular protein synthesis as estimated by 14 C-leucine uptake to about 15%, and DNA synthesis ( 3 H-thymidine incorporation) to about 5% of untreated control cells. In contrast to y-irradiated cells, viability of heated cells rapidly declined within the first 24 hr. Hyperthermic treatment doubled binding of mouse immunoglobulin paralleled by an increased expression of IL-2 and transferrin receptors, while expression of HLA-DR and 4F2 proteins appeared unchanged. Stimulation with heated cells triggered the release of IL-1- and an IL-3-like bioactivity but did not induce IL-2 synthesis and/or release, thus explaining the lack of proliferation in the HMLR. Addition of exogenous IL-2 but not IL-1 restored HMLR proliferation. A comparison of allostimulation with y-irradiated and heat-treated cells revealed that significantly fewer T cells were induced to express IL-2 receptors at day 3 (14% vs. 8%, P less than 0.001) and at day 6 (42% vs. 21%, P less than 0.05) with heat-inactivated stimulators

  10. Use of the local lymph node assay in assessment of immune function.

    Science.gov (United States)

    van den Berg, Femke A; Baken, Kirsten A; Vermeulen, Jolanda P; Gremmer, Eric R; van Steeg, Harry; van Loveren, Henk

    2005-07-01

    The murine local lymph node assay (LLNA) was originally developed as a predictive test method for the identification of chemicals with sensitizing potential. In this study we demonstrated that an adapted LLNA can also be used as an immune function assay by studying the effects of orally administered immunomodulating compounds on the T-cell-dependent immune response induced by the contact sensitizer 2,4-dinitrochlorobenzene (DNCB). C57Bl/6 mice were treated with the immunotoxic compounds cyclosporin A (CsA), bis(tri-n-butyltin)oxide (TBTO) or benzo[a]pyrene, (B[a]P). Subsequently, cell proliferation and interferon-gamma (IFN-gamma) and interleukin (IL)-4 release were determined in the auricular lymph nodes (LNs) after DNCB application on both ears. Immunosuppression induced by CsA, TBTO and B[a]P was clearly detectable in this application of the LLNA. Cytokine release measurements proved valuable to confirm the results of the cell proliferation assay and to obtain an indication of the effect on Th1/Th2 balance. We believe to have demonstrated the applicability of an adapted LLNA as an immune function assay in the mouse.

  11. Gamma Knife

    Science.gov (United States)

    ... News Physician Resources Professions Site Index A-Z Gamma Knife Gamma Knife® is a radiation therapy that uses computerized ... If you're scheduled for radiation therapy using Gamma Knife®, a treatment team consisting of a radiation ...

  12. Atorvastatin prevents age-related and amyloid-beta-induced microglial activation by blocking interferon-gamma release from natural killer cells in the brain

    LENUS (Irish Health Repository)

    Lyons, Anthony

    2011-03-31

    Abstract Background Microglial function is modulated by several factors reflecting the numerous receptors expressed on the cell surface, however endogenous factors which contribute to the age-related increase in microglial activation remain largely unknown. One possible factor which may contribute is interferon-γ (IFNγ). IFNγ has been shown to increase in the aged brain and potently activates microglia, although its endogenous cell source in the brain remains unidentified. Methods Male Wistar rats were used to assess the effect of age and amyloid-β (Aβ) on NK cell infiltration into the brain. The effect of the anti-inflammatory compound, atorvastatin was also assessed under these conditions. We measured cytokine and chemokine (IFNγ, IL-2, monocyte chemoattractant protein-1 (MCP-1) and IFNγ-induced protein 10 kDa (IP-10)), expression in the brain by appropriate methods. We also looked at NK cell markers, CD161, NKp30 and NKp46 using flow cytometry and western blot. Results Natural killer (NK) cells are a major source of IFNγ in the periphery and here we report the presence of CD161+ NKp30+ cells and expression of CD161 and NKp46 in the brain of aged and Aβ-treated rats. Furthermore, we demonstrate that isolated CD161+ cells respond to interleukin-2 (IL-2) by releasing IFNγ. Atorvastatin, the HMG-CoA reductase inhibitor, attenuates the increase in CD161 and NKp46 observed in hippocampus of aged and Aβ-treated rats. This was paralleled by a decrease in IFNγ, markers of microglial activation and the chemokines, MCP-1 and IP-10 which are chemotactic for NK cells. Conclusions We propose that NK cells contribute to the age-related and Aβ-induced neuroinflammatory changes and demonstrate that these changes can be modulated by atorvastatin treatment.

  13. Evaluation of γ-radiation-induced DNA damage in two species of bivalves and their relative sensitivity using comet assay.

    Science.gov (United States)

    Praveen Kumar, M K; Shyama, S K; Sonaye, B S; Naik, U Roshini; Kadam, S B; Bipin, P D; D'costa, A; Chaubey, R C

    2014-05-01

    Ionizing radiation is known to induce genetic damage in diverse groups of organisms. Under accidental situations, large quantities of radioactive elements get released into the environment and radiation emitted from these radionuclides may adversely affect both the man and the non-human biota. The present study is aimed (a) to know the genotoxic effect of gamma radiation on aquatic fauna employing two species of selected bivalves, (b) to evaluate the possible use of 'Comet assay' for detecting genetic damage in haemocytes of bivalves as a biomarker for environmental biomonitoring and also (c) to compare the relative sensitivity of two species of bivalves viz. Paphia malabarica and Meretrix casta to gamma radiation. The comet assays was optimized and validated using different concentrations (18, 32 and 56 mg/L) of ethyl methanesulfonate (EMS), a direct-acting reference genotoxic agent, to which the bivalves were exposed for various times (24, 48 and 72 h). Bivalves were irradiated (single acute exposure) with 5 different doses (viz. 2, 4, 6, 8 and 10 Gy) of gamma radiation and their genotoxic effects on the haemocytes were studied using the comet assay. Haemolymph was collected from the adductor muscle at 24, 48 and 72 h of both EMS-exposed and irradiated bivalves and comet assay was carried out using standard protocol. A significant increase in DNA damage was observed as indicated by an increase in % tail DNA damage at different concentrations of EMS and all the doses of gamma radiation as compared to controls in both bivalve species. This showed a dose-dependent increase of genetic damage induced in bivalves by EMS as well as gamma radiation. Further, the highest DNA damage was observed at 24h. The damage gradually decreased with time, i.e. was smaller at 48 and 72 h than at 24h post irradiation in both species of bivalves. This may indicate repair of the damaged DNA and/or loss of heavily damaged cells as the post irradiation time advanced. The present study

  14. Cross-validated stable-isotope dilution GC-MS and LC-MS/MS assays for monoacylglycerol lipase (MAGL) activity by measuring arachidonic acid released from the endocannabinoid 2-arachidonoyl glycerol.

    Science.gov (United States)

    Kayacelebi, Arslan Arinc; Schauerte, Celina; Kling, Katharina; Herbers, Jan; Beckmann, Bibiana; Engeli, Stefan; Jordan, Jens; Zoerner, Alexander A; Tsikas, Dimitrios

    2017-03-15

    2-Arachidonoyl glycerol (2AG) is an endocannabinoid that activates cannabinoid (CB) receptors CB1 and CB2. Monoacylglycerol lipase (MAGL) inactivates 2AG through hydrolysis to arachidonic acid (AA) and glycerol, thus modulating the activity at CB receptors. In the brain, AA released from 2AG by the action of MAGL serves as a substrate for cyclooxygenases which produce pro-inflammatory prostaglandins. Here we report stable-isotope GC-MS and LC-MS/MS assays for the reliable measurement of MAGL activity. The assays utilize deuterium-labeled 2AG (d 8 -2AG; 10μM) as the MAGL substrate and measure deuterium-labeled AA (d 8 -AA; range 0-1μM) as the MAGL product. Unlabelled AA (d 0 -AA, 1μM) serves as the internal standard. d 8 -AA and d 0 -AA are extracted from the aqueous buffered incubation mixtures by ethyl acetate. Upon solvent evaporation the residue is reconstituted in the mobile phase prior to LC-MS/MS analysis or in anhydrous acetonitrile for GC-MS analysis. LC-MS/MS analysis is performed in the negative electrospray ionization mode by selected-reaction monitoring the mass transitions [M-H] - →[M-H - CO 2 ] - , i.e., m/z 311→m/z 267 for d 8 -AA and m/z 303→m/z 259 for d 0 -AA. Prior to GC-MS analysis d 8 -AA and d 0 -AA were converted to their pentafluorobenzyl (PFB) esters by means of PFB-Br. GC-MS analysis is performed in the electron-capture negative-ion chemical ionization mode by selected-ion monitoring the ions [M-PFB] - , i.e., m/z 311 for d 8 -AA and m/z 303 for d 0 -AA. The GC-MS and LC-MS/MS assays were cross-validated. Linear regression analysis between the concentration (range, 0-1μM) of d 8 -AA measured by LC-MS/MS (y) and that by GC-MS (x) revealed a straight line (r 2 =0.9848) with the regression equation y=0.003+0.898x, indicating a good agreement. In dog liver, we detected MAGL activity that was inhibitable by the MAGL inhibitor JZL-184. Exogenous eicosatetraynoic acid is suitable as internal standard for the quantitative determination

  15. Assay system

    International Nuclear Information System (INIS)

    Patzke, J.B.; Rosenberg, B.J.

    1984-01-01

    The accuracy of assays for monitoring concentrations of basic drugs in biological fluids containing a 1 -acid glycoproteins, such as blood (serum or plasma), is improved by the addition of certain organic phosphate compounds to minimize the ''protein effect.'' Kits containing the elements of the invention are also disclosed

  16. Direct Assay of Filter Media following DEOX Testing

    International Nuclear Information System (INIS)

    R.P. Lind; J.J. Giglio; D.G. Cummings; M.W. Huntley; C.D. Morgan; K.J. Bateman; D.L. Wahlquist; D.A. Sell

    2007-01-01

    The direct assay of filter media by gamma spectrometry following DEOX testing has distinct advantages over analytical chemistry. Prior to using gamma spectrometry for the quantification of cesium (Cs-137), a calibration must be established with known sources since gamma spectrometry yields relative results. Quantitative analytical chemistry, in particular ICP-MS, has been performed on the filter media for comparison to the gamma spectrometry data. The correlation of gamma spectrometry to ICP-MS data is presented to justify the continued use of gamma spectrometry for filter media

  17. Direct assay of filter media following DEOX testing

    International Nuclear Information System (INIS)

    Westphal, B.R.; Lind, R.P.; Giglio, J.J.; Cummings, D.G.; Huntley, M.W.; Morgan, C.D.; Bateman, K.J.; Wahlquist, D.L.; Sell, D.A.

    2007-01-01

    The direct assay of filter media by gamma spectrometry following DEOX testing has distinct advantages over analytical chemistry. Prior to using gamma spectrometry for the quantification of cesium (Cs- 137), a calibration must be established with known sources since gamma spectrometry yields relative results. Quantitative analytical chemistry, in particular ICP-MS, has been performed on the filter media for comparison to the gamma spectrometry data. The correlation of gamma spectrometry to ICP-MS data is presented to justify the continued use of gamma spectrometry for filter media. (authors)

  18. Fundamentals of passive nondestructive assay of fissionable material: laboratory workbook

    International Nuclear Information System (INIS)

    Reilly, T.D.; Augustson, R.H.; Parker, J.L.; Walton, R.B.; Atwell, T.L.; Umbarger, C.J.; Burns, C.E.

    1975-02-01

    This workbook is a supplement to LA-5651-M, ''Fundamentals of Passive Nondestructive Assay of Fissionable Material'' which is the text used during the Nondestructive Assay Training Session given by Group A-1 of the Los Alamos Scientific Laboratory. It contains the writeups used during the six laboratory sessions covering basic gamma-ray principles, quantitative gamma-ray measurements, uranium enrichment measurements, equipment holdup measurements, basic neutron principles, and quantitative neutron assay

  19. Fundamentals of passive nondestructive assay of fissionable material: laboratory workbook

    Energy Technology Data Exchange (ETDEWEB)

    Reilly, T.D.; Augustson, R.H.; Parker, J.L. Walton, R.B.; Atwell, T.L.; Umbarger, C.J.; Burns, C.E.

    1975-02-01

    This workbook is a supplement to LA-5651-M, ''Fundamentals of Passive Nondestructive Assay of Fissionable Material'' which is the text used during the Nondestructive Assay Training Session given by Group A-1 of the Los Alamos Scientific Laboratory. It contains the writeups used during the six laboratory sessions covering basic gamma-ray principles, quantitative gamma-ray measurements, uranium enrichment measurements, equipment holdup measurements, basic neutron principles, and quantitative neutron assay.

  20. Solution assay instrument operations manual

    International Nuclear Information System (INIS)

    Li, T.K.; Marks, T.; Parker, J.L.

    1983-09-01

    An at-line solution assay instrument (SAI) has been developed and installed in a plutonium purification and americium recovery process area in the Los Alamos Plutonium Processing Facility. The instrument was designed for accurate, timely, and simultaneous nondestructive analysis of plutonium and americium in process solutions that have a wide range of concentrations and americium/plutonium ratios and for routine operation by process technicians who lack instrumentation background. The SAI, based on transmission-corrected, high-resolution gamma-ray spectroscopy, has two measurement stations attached to a single multichannel analyzer/computer system. To ensure the quality of assay results, the SAI has an internal measurement control program, which requires daily and weekly check runs and monitors key aspects of all assay runs. For a 25-ml sample, the assay precision is 5 g/l within a 2000-s count time

  1. Analysis of copper-nickel ores by gamma-gamma method in ore enrichment works

    International Nuclear Information System (INIS)

    Bol'shakov, A.Yu.; Tovstenko, Yu.G.; Chinskij, E.B.; Eliseev, G.I.

    1973-01-01

    The paper presents experimental data on continuous gamma-gamma assay of copper-nickel ores on conveyor belts and of dry discrete samples of classifier overflow at the enrichment plants of the Pechenganikel' group. The relative errors are given of the results of comparison of two-hour rapid analyses and shift and 24-hour chemical analyses of classifier overflow samples with the figures for gamma-gamma assay. The factors affecting the accuracy of the latter technique are elucidated. Practical recommendations are given on the use of this technique at the above enrichment plants. (author)

  2. Safety and efficacy of the C-Tb skin test to diagnose Mycobacterium tuberculosis infection, compared with an interferon γ release assay and the tuberculin skin test: a phase 3, double-blind, randomised, controlled trial.

    Science.gov (United States)

    Ruhwald, Morten; Aggerbeck, Henrik; Gallardo, Rafael Vázquez; Hoff, Søren T; Villate, José I; Borregaard, Bettine; Martinez, José A; Kromann, Ingrid; Penas, Antón; Anibarro, Luis L; de Souza-Galvão, Maria Luiza; Sánchez, Francisca; Rodrigo-Pendás, Jose Ángel; Noguera-Julian, Antoni; Martínez-Lacasa, Xavier; Tuñez, Maria Victoria; Fernández, Virginia Leiro; Millet, Joan P; Moreno, Antonio; Cobos, Nazaret; Miró, José M; Roldan, Llanos; Orcau, Angels; Andersen, Peter; Caylá, Joan A

    2017-04-01

    Targeted screening and treatment of Mycobacterium tuberculosis infection substantially reduces the risk of developing active tuberculosis. C-Tb (Statens Serum Institute, Copenhagen, Denmark) is a novel specific skin test based on ESAT-6 and CFP10 antigens. We investigated the safety and diagnostic potential of C-Tb compared with established tests in the contact-tracing setting. Negative controls, close contacts, occasional contacts, and patients with active pulmonary tuberculosis were enrolled at 13 centres in Spain. We compared C-Tb with the QuantiFERON-TB Gold In-Tube ([QFT] Qiagen, Hilden, Germany) interferon γ release assay (IGRA) and the purified protein derivative (PPD) RT 23 tuberculin skin test ([TST] Statens Serum Institute). All participants older than 5 years were tested with QFT. Some participants in the negative control group received C-Tb without the TST to test for potential interactions between C-Tb and PPD RT 23. The rest were randomly assigned in blocks of ten and tested with both C-Tb and TST, with five in each block receiving injection of C-Tb in the right arm and the TST in the left arm and five vice versa. The primary and safety analyses were done in all participants randomly assigned to a group who received any test. This trial is registered with ClinicalTrials.gov, number NCT01631266, and with EudraCT, number 2011-005617-36. From July 24, 2012, to Oct 2, 2014, 979 participants were enrolled, of whom 263 were negative controls, 299 were occasional contacts, 316 were close contacts, and 101 were patients with tuberculosis. 970 (99%) participants completed the trial. Induration sizes were similar for C-Tb and TST, but TST positivity was affected by BCG vaccination status. We found a strong positive trend towards C-Tb test positivity with increasing risk of infection, from 3% in negative controls to 16% in occasional contacts, to 43% in close contacts. C-Tb and QFT results were concordant in 785 (94%) of 834 participants aged 5 years and older

  3. Matrix effects of TRU [transuranic] assays using the SWEPP PAN assay system

    International Nuclear Information System (INIS)

    Smith, J.R.

    1990-08-01

    The Drum Assay System (DAS) at the Stored Waste Experimental Pilot Plant (SWEPP) is a second-generation active-passive neutron assay system. It has been used to assay over 5000 208-liter drums of transuranic waste from the Rocky Flats Plant (RFP). Data from these assays have been examined and compared with the assays performed at Rocky Flats, mainly utilize counting of 239 Pu gamma rays. For the most part the passive assays are in very good agreement with the Rocky Flats assays. The active assays are strongly correlated with the results of the other two methods, but require matrix-dependent correction factors beyond those provided by the system itself. A set of matrix-dependent correction factors has been developed from the study of the assay results. 3 refs., 4 figs., 3 tabs

  4. Passive nondestructive assay of nuclear materials

    International Nuclear Information System (INIS)

    Reilly, D.; Ensslin, N.; Smith, H. Jr.; Kreiner, S.

    1991-03-01

    The term nondestructive assay (NDA) is applied to a series of measurement techniques for nuclear fuel materials. The techniques measure radiation induced or emitted spontaneously from the nuclear material; the measurements are nondestructive in that they do not alter the physical or chemical state of the nuclear material. NDA techniques are characterized as passive or active depending on whether they measure radiation from the spontaneous decay of the nuclear material or radiation induced by an external source. This book emphasizes passive NDA techniques, although certain active techniques like gamma-ray absorption densitometry and x-ray fluorescence are discussed here because of their intimate relation to passive assay techniques. The principal NDA techniques are classified as gamma-ray assay, neutron assay, and calorimetry. Gamma-ray assay techniques are treated in Chapters 1--10. Neutron assay techniques are the subject of Chapters 11--17. Chapters 11--13 cover the origin of neutrons, neutron interactions, and neutron detectors. Chapters 14--17 cover the theory and applications of total and coincidence neutron counting. Chapter 18 deals with the assay of irradiated nuclear fuel, which uses both gamma-ray and neutron assay techniques. Chapter 19 covers perimeter monitoring, which uses gamma-ray and neutron detectors of high sensitivity to check that no unauthorized nuclear material crosses a facility boundary. The subject of Chapter 20 is attribute and semiquantitative measurements. The goal of these measurements is a rapid verification of the contents of nuclear material containers to assist physical inventory verifications. Waste and holdup measurements are also treated in this chapter. Chapters 21 and 22 cover calorimetry theory and application, and Chapter 23 is a brief application guide to illustrate which techniques can be used to solve certain measurement problems

  5. Elements of nondestructive assay (NDA) technology

    International Nuclear Information System (INIS)

    Anon.

    1981-01-01

    This session provides an introduction to nondestructive assay methods and instruments as they are applied to nuclear safeguards. The purpose of the sessions is to enable participants to: (1) discuss the general principles and major applications of NDA; (2) describe situations in which NDA is particularly useful for nuclear safeguards purposes; (3) distinguish between various passive and active gamma-ray and neutron NDA methods; (4) describe several NDA instruments that measure gamma rays, and identify assay situations particularly suited to gamma-ray techniques; (5) describe several NDA instruments that measure neutrons, and identify assay situations particularly suited to neutron techniques; (6) discuss the role of calorimetry in the NDA of plutonium-bearing materials; and (7) compare the advantages and disadvantages of various NDA methods for different types of nuclear materials

  6. 233U Assay A Neutron NDA System

    Energy Technology Data Exchange (ETDEWEB)

    Hensley, D.C.; Lucero, A.J.; Pierce, L.

    1998-11-17

    The assay of highly enriched {sup 233}U material presents some unique challenges. Techniques which apply to the assay of materials of Pu or enriched {sup 235}U do not convert easily over to the assay of {sup 233}U. A specialized neutron assay device is being fabricated to exploit the singles neutron signal, the weak correlated neutron signal, and an active correlated signal. These pieces of information when combined with {gamma} ray isotopics information should give a good overall determination of {sup 233}U material now stored in bldg. 3019 at the Oak Ridge National Laboratory.

  7. Safeguards and Non-destructive Assay

    International Nuclear Information System (INIS)

    Carchon, R.; Bruggeman, M.

    2001-01-01

    SCK-CEN's programme on safeguards and non-destructive assay includes: (1) various activities to assure nuclear materials accountancy; (2) contributes to the implementation of Integrated Safeguards measures in Belgium and to assist the IAEA through the Belgian Support Programme; (3) renders services to internal and external customers in the field of safeguards; (4) improves passive neutron coincidence counting techniques for waste assay and safeguards verification measurements by R and D on correlation algorithms implemented via software or dedicated hardware; (5) improves gamma assay techniques for waste assay by implementing advanced scanning techniques and different correlation algorithms; and (6) develops numerical calibration techniques. Major achievements in these areas in 2000 are reported

  8. High Affinity IgE-Fc Receptor alpha and gamma Subunit Interactions

    International Nuclear Information System (INIS)

    Rashid, A.; Housden, J. E. M.; Sabban, S.; Helm, B.

    2014-01-01

    Objective: To explore the relationships between the subunits (alpha, beta and gamma) of the high affinity IgE receptor (Fc and RI) and its ability to mediate transmembrane signaling. Study Design: Experimental study. Place and Duration of Study: Department of Molecular Biology and Biotechnology, University of Sheffield, UK, from 2008 to 2009. Methodology: The approach employed was to create a chimera (human alpha-gamma-gamma) using the extracellular (EC) domain of the human high affinity IgE receptor. The alpha subunit (huFc and RIalpha) of IgE receptor was spliced onto the rodent gamma TM and cytoplasmic domain (CD). This was transfected into the Rat Basophilic Leukemia cell line in order to assess the possibility of selectively activating cells transfected with this single pass construct for antigen induced mediator release. Results: The RBLs cell lines transfected with the huFc and RIalpha/gamma/gamma cDNA constructs were assessed for the cell surface expression of the huFc and RIalpha subunit and the response to the antigenic stimulus by looking for degranulation and intracellular Ca2+ mobilisation. The results obtained showed the absence of huFc and RIalpha subunit expression on the surface of transfected cells as seen by flowcytometric studies, beta-hexosaminidase assays and intracellular calcium mobilisation studies. Conclusion: In the present study the grounds for non-expression of huFc and RIalpha/gamma/gamma cDNA remains elusive but may be due to the fact that the human-rodent chimeric receptors are assembled differently than the endogenous rodent receptors as seen in study in which COS 7 cells were transfected with human/rat chimeric complexes. (author)

  9. Gamma astronomy

    International Nuclear Information System (INIS)

    Cesarsky, C.; Cesarsky, J.P.

    1986-01-01

    This article overviews the gamma astronomy research. Sources already observed, and what causes to give to them; the galactic radiation and its interpretation; techniques already used and current projects [fr

  10. Gamma Spectroscopy

    NARCIS (Netherlands)

    Niemantsverdriet, J.W.; Butz, Tilman; Ertl, G.; Knözinger, H.; Schüth, F.

    2008-01-01

    No abstract. The sections in this article are 1 Introduction 2 Mössbauer Spectroscopy 3 Time-Differential Perturbed Angular Correlations (TDPAC) 4 Conclusions and Outlook Keywords: Mössbauer spectroscopy; gamma spectroscopy; perturbed angular correlation; TDPAC

  11. Radiomodifying effect of caffeine on mammalian cellular system using gamma radiation and proton beam radiation

    International Nuclear Information System (INIS)

    Samanth, Sneha P.; Yadav, Usha; Shirsath, K.B.; Desai, Utkarsha N.; Chaurasia, Rajesh K.; Bhat, Nagesh N.; Anjaria, K.B.; Sapra, B.K.

    2016-01-01

    Caffeine is a commonly consumed neurostimulant in the world. Reports suggest the radiomodifying effects of caffeine against low Linear Energy Transfer (LET) radiation when administered pre and post irradiation by releasing checkpoint arrest. In the present report, the radioprotective and radiosensitizing ability of caffeine (10μM - 2mM) were studied on Chinese Hamster Ovary (CRO) cell line against low as well as high LET radiation when administered pre, post and continuously during radiation. Effect of caffeine treatment on the genotoxicity induced by gamma and proton beam radiation was assessed by micronucleus assay. Effect of caffeine treatment on clonogenic survival of irradiated cells was also assessed

  12. Nondestructive assay methods for irradiated nuclear fuels

    International Nuclear Information System (INIS)

    Hsue, S.T.; Crane, T.W.; Talbert, W.L. Jr.; Lee, J.C.

    1978-01-01

    This report is a review of the status of nondestructive assay (NDA) methods used to determine burnup and fissile content of irradiated nuclear fuels. The gamma-spectroscopy method measures gamma activities of certain fission products that are proportional to the burnup. Problems associated with this method are migration of the fission products and gamma-ray attenuation through the relatively dense fuel material. The attenuation correction is complicated by generally unknown activity distributions within the assemblies. The neutron methods, which usually involve active interrogation and prompt or delayed signal counting, are designed to assay the fissile content of the spent-fuel elements. Systems to assay highly enriched spent-fuel assemblies have been tested extensively. Feasibility studies have been reported of systems to assay light-water reactor spent-fuel assemblies. The slowing-down spectrometer and neutron resonance absorption methods can distinguish between the uranium and plutonium fissile contents, but they are limited to the assay of individual rods. We have summarized the status of NDA techniques for spent-fuel assay and present some subjects in need of further investigation. Accuracy of the burnup calculations for power reactors is also reviewed

  13. An ultrafiltration assay for lysyl oxidase

    International Nuclear Information System (INIS)

    Shackleton, D.R.; Hulmes, D.J.

    1990-01-01

    A modification of the original microdistillation assay for lysyl oxidase is described in which Amicon C-10 microconcentrators are used to separate, by ultrafiltration, the 3H-labeled products released from a [4,5-3H]-lysine-labeled elastin substrate. Enzyme activity is determined by scintillation counting of the ultrafiltrate, after subtraction of radioactivity released in the presence of beta-aminopropionitrile, a specific inhibitor of the enzyme. Conditions are described which optimize both the sensitivity and the efficient use of substrate. The assay shows linear inhibition of activity in up to 1 M urea; hence, as the enzyme is normally diluted in the assay, samples in 6 M urea can be assayed directly, without prior dialysis, and corrected for partial inhibition. Comparable results are obtained when enzyme activity is assayed by ultrafiltration or microdistillation. The assay is simple and convenient and, by using disposable containers throughout, it eliminates the need for time-consuming decontamination of radioactive glassware

  14. Mechanism and kinetics of the loss of poorly soluble drugs from liposomal carriers studied by a novel flow field-flow fractionation-based drug release-/transfer-assay

    DEFF Research Database (Denmark)

    Hinna, Askell Hvid; Hupfeld, Stefan; Kuntsche, Judith

    2016-01-01

    Liposomes represent a versatile drug formulation approach e.g. for improving the water-solubility of poorly soluble drugs but also to achieve drug targeting and controlled release. For the latter applications it is essential that the drug remains associated with the liposomal carrier during transit...... in the vascular bed. A range of in vitro test methods has been suggested over the years for prediction of the release of drug from liposomal carriers. The majority of these fail to give a realistic prediction for poorly water-soluble drugs due to the intrinsic tendency of such compounds to remain associated...... the amount of drug remaining associated with the liposomal drug carrier as well as that transferred to the acceptor liposomes at distinct times of incubation, boththe kinetics of drug transfer and release to the water phase could be established for the model drug p-THPP (5,10,15,20-tetrakis(4-hydroxyphenyl...

  15. Nondestructive assay of boxed radioactive waste

    International Nuclear Information System (INIS)

    Gilles, W.P.; Roberts, R.J.; Jasen, W.G.

    1992-12-01

    This paper describes the problems related to the nondestructive assay (NDA) of boxed radioactive waste at the Hanford Site and how Westinghouse Hanford company (WHC) is solving the problems. The waste form and radionuclide content are described. The characteristics of the combined neutron and gamma-based measurement system are described

  16. Nondestructive assay measurements applied to reprocessing plants

    International Nuclear Information System (INIS)

    Ruhter, Wayne D.; Lee, R. Stephen; Ottmar, Herbert; Guardini, Sergio

    1999-01-01

    Nondestructive assay for reprocessing plants relies on passive gamma-ray spectrometry for plutonium isotopic and plutonium mass values of medium-to-low-density samples and holdup deposits; on active x-ray fluorescence and densitometry techniques for uranium and plutonium concentrations in solutions; on calorimetry for plutonium mass in product; and passive neutron techniques for plutonium mass in spent fuel, product, and waste. This paper will describe the radiation-based nondestructive assay techniques used to perform materials accounting measurements. The paper will also discuss nondestructive assay measurements used in inspections of reprocessing plants [ru

  17. Gamma camera

    International Nuclear Information System (INIS)

    Berninger, W.H.

    1975-01-01

    The light pulse output of a scintillator, on which incident collimated gamma rays impinge, is detected by an array of photoelectric tubes each having a convexly curved photocathode disposed in close proximity to the scintillator. Electronic circuitry connected to outputs of the phototubes develops the scintillation event position coordinate electrical signals with good linearity and with substantial independence of the spacing between the scintillator and photocathodes so that the phototubes can be positioned as close to the scintillator as is possible to obtain less distortion in the field of view and improved spatial resolution as compared to conventional planar photocathode gamma cameras

  18. Development of an integrated assay facility

    International Nuclear Information System (INIS)

    Molesworth, T.V.; Bailey, M.; Findlay, D.J.S.; Parsons, T.V.; Sene, M.R.; Swinhoe, M.T.

    1990-01-01

    The I.R.I.S. concept proposed the use of passive examination and active interrogation techniques in an integrated assay facility. A linac would generate the interrogating gamma and neutron beams. Insufficiently detailed knowledge about active neutron and gamma interrogation of 500 litre drums of cement immobilised intermediate level waste led to a research programme which is now in its main experimental stage. Measurements of interrogation responses are being made using simulated waste drums containing actinide samples and calibration sources, in an experimental assay assembly. Results show that responses are generally consistent with theory, but that improvements are needed in some areas. A preliminary appraisal of the engineering and economic aspects of integrated assay shows that correct operational sequencing is required to achieve the short cycle time needed for high throughput. The main engineering features of a facility have been identified

  19. Gamma-ray measurements with the segmented gamma scan

    International Nuclear Information System (INIS)

    Martin, E.R.; Jones, D.F.; Parker, J.L.

    1977-12-01

    A revised and updated operation and maintenance manual for the segmented gamma-scan instrument is presented, which describes routine assay techniques as well as the theory of operation in sufficient depth that an experienced assayist can make nonroutine assays on a wide variety of materials and samples. In addition, complete electronic and electrical schematics of the Los Alamos Scientific Laboratory (LASL)-designed portions of the system are presented, along with sufficient system and circuit description to facilitate maintenance and troubleshooting. Complete software system descriptions are included, although detailed listings would have to be obained from LASL in order to make machine-language code changes

  20. Gamma camera

    International Nuclear Information System (INIS)

    Tschunt, E.; Platz, W.; Baer, Ul; Heinz, L.

    1978-01-01

    A gamma camera has a plurality of exchangeable collimators, one of which is replaceably mounted in the ray inlet opening of the camera, while the others are placed on separate supports. Supports are swingably mounted upon a column one above the other

  1. Gamma camera

    International Nuclear Information System (INIS)

    Schlosser, P.A.; Steidley, J.W.

    1980-01-01

    The design of a collimation system for a gamma camera for use in nuclear medicine is described. When used with a 2-dimensional position sensitive radiation detector, the novel system can produce superior images than conventional cameras. The optimal thickness and positions of the collimators are derived mathematically. (U.K.)

  2. Nondestructive assay of sale materials

    International Nuclear Information System (INIS)

    Rodenburg, W.W.; Fleissner, J.G.

    1981-01-01

    This paper covers three primary areas: (1) reasons for performing nondestructive assay on SALE materials; (2) techniques used; and (3) discussion of investigators' revised results. The study shows that nondestructive calorimetric assay of plutonium offers a viable alternative to traditional wet chemical techniques. For these samples, the precision ranged from 0.4 to 0.6% with biases less than 0.2%. Thus, for those materials where sampling errors are the predominant source of uncertainty, this technique can provide improved accuracy and precision while saving time and money as well as reducing the amount of liquid wastes to be handled. In addition, high resolution gamma-ray spectroscopy measurements of solids can provide isotopic analysis data in a cost effective and timely manner. The timeliness of the method can be especially useful to the plant operator for production control and quality control measurements

  3. Insecticidal and sterilizing effect of Olyset Duo (R), a permethrin and pyriproxyfen mixture net against pyrethroid-susceptible and -resistant strains of Anopheles gambiae s.s. : a release-recapture assay in experimental huts

    OpenAIRE

    Djènontin, A.; Alou, L. P. A.; Koffi, A.; Zogo, B.; Duarte, E.; N'Guessan, R.; Moiroux, Nicolas; Pennetier, Cédric

    2015-01-01

    In the context of the widespread distribution of pyrethroid resistance among malaria vectors, we did a release-recapture trial in experimental huts to investigate the insecticidal and sterilizing effects of a novel long-lasting net (LN), Olyset (R) Duo, incorporating a mixture of permethrin (PER) and the insect growth regulator (IGR), pyriproxyfen (PPF). An LN containing PPF alone and a classic Olyset (R) Net were tested in parallel as positive controls. The effect of progressive number of ho...

  4. Selection of non-destructive assay methods: Neutron counting or calorimetric assay?

    International Nuclear Information System (INIS)

    Cremers, T.L.; Wachter, J.R.

    1994-01-01

    The transition of DOE facilities from production to D ampersand D has lead to more measurements of product, waste, scrap, and other less attractive materials. Some of these materials are difficult to analyze by either neutron counting or calorimetric assay. To determine the most efficacious analysis method, variety of materials, impure salts and hydrofluorination residues have been assayed by both calorimetric assay and neutron counting. New data will be presented together with a review of published data. The precision and accuracy of these measurements are compared to chemistry values and are reported. The contribution of the gamma ray isotopic determination measurement to the overall error of the calorimetric assay or neutron assay is examined and discussed. Other factors affecting selection of the most appropriate non-destructive assay method are listed and considered

  5. TRU assay system and measurements

    International Nuclear Information System (INIS)

    Brodzinski, R.L.

    1984-02-01

    The measurement of the transuranic content of nuclear products or process residues has become increasingly important for the recovery of fissionable material from spent fuel elements, the identification of commercial fuel elements which have not yet reached full burnup, the measurement and recovery of transuranics from discarded or stored waste materials, the determination of the transuranic content in high gamma activity waste material scheduled for disposal, compliance with 10CFR61 by land burial operators/shippers, and the satisfaction of accountability requirements. Active neutron interrogation techniques measure either the prompt neutrons or the beta delayed neutrons from fission products following induced fission. These techniques normally only measure fissile transuranics ( 235 U, 239 Pu, and 241 Pu) and are commonly applied only to contact handleable waste. Passive neutron interrogation techniques, on the other hand, are capable of measuring all transuranics except 235 U with adequate sensitivity and will work on both contact handleable and high gamma activity wastes. Since the passive techniques are senstitive to a wider spectrum of transuranic isotopes than the active techniques, substantially less complex and less expensive than the active systems, and they have proven techniques for measuring small quantities of TRU in high gamma activity packages, the passive neutron TRU assay technology was chosen for development into the instruments discussed in this paper

  6. Gamma camera

    International Nuclear Information System (INIS)

    Reiss, K.H.; Kotschak, O.; Conrad, B.

    1976-01-01

    A gamma camera with a simplified setup as compared with the state of engineering is described permitting, apart from good localization, also energy discrimination. Behind the usual vacuum image amplifier a multiwire proportional chamber filled with trifluorine bromium methane is connected in series. Localizing of the signals is achieved by a delay line, energy determination by means of a pulse height discriminator. With the aid of drawings and circuit diagrams, the setup and mode of operation are explained. (ORU) [de

  7. Gamma irradiator

    International Nuclear Information System (INIS)

    Simonet, G.

    1986-09-01

    Fiability of devices set around reactors depends on material resistance under irradiation noticeably joints, insulators, which belongs to composition of technical, safety or physical incasurement devices. The irradiated fuel elements, during their desactivation in a pool, are an interesting gamma irradiation device to simulate damages created in a nuclear environment. The existing facility at Osiris allows to generate an homogeneous rate dose in an important volume. The control of the element distances to irradiation box allows to control this dose rate [fr

  8. Gamma teletopography

    International Nuclear Information System (INIS)

    Simonet, G.

    1987-06-01

    The mapping of gamma sources radiation emission in a nuclear plant is an important safety point. A remote gamma ray mapping process was developed in SPS/CEA/SACLAY. It uses the ''pinhole camera'' principle, precursor of photography. It mainly consists of a radiation proof box, with a small orifice, containing sensitive emulsions at the opposite. A first conventional photographic type emulsion photographs the area. A second photographic emulsion shows up the gamma radiations. The superim position of the two shots gives immediate informations of the precise location of each source of radiation in the observed area. To make easier the presentation and to improve the accuracy of the results for radiation levels mapping, the obtained films are digitally processed. The processing assigns a colours scale to the various levels of observed radiations. Taking account physical data and standard parameters, it gets possible to estimate the dose rate. The device is portable. Its compactness and fully independent nature make it suitable for use anywhere. It can be adapted to a remote automatic handling system, robot... so as to avoid all operator exposure when the local dose rate is too high [fr

  9. Evaluation of γ-radiation-induced DNA damage in two species of bivalves and their relative sensitivity using comet assay

    International Nuclear Information System (INIS)

    Praveen Kumar, M.K.; Shyama, S.K.; Sonaye, B.S.; Naik, U Roshini; Kadam, S.B.; Bipin, P.D.; D’costa, A.; Chaubey, R.C.

    2014-01-01

    Highlights: • Possible genotoxic effect of accidental exposure of aquatic fauna to γ radiation. • Relative sensitivity of bivalves to γ radiation is also analyzed using comet assay. • γ radiation induced significant genetic damage in both the species of bivalves. • P. malabarica and M. casta exhibited a similar level of sensitivity to γ radiation. • Comet assay may be used as a biomarker for the environmental biomonitoring. - Abstract: Ionizing radiation is known to induce genetic damage in diverse groups of organisms. Under accidental situations, large quantities of radioactive elements get released into the environment and radiation emitted from these radionuclides may adversely affect both the man and the non-human biota. The present study is aimed (a) to know the genotoxic effect of gamma radiation on aquatic fauna employing two species of selected bivalves, (b) to evaluate the possible use of ‘Comet assay’ for detecting genetic damage in haemocytes of bivalves as a biomarker for environmental biomonitoring and also (c) to compare the relative sensitivity of two species of bivalves viz. Paphia malabarica and Meretrix casta to gamma radiation. The comet assays was optimized and validated using different concentrations (18, 32 and 56 mg/L) of ethyl methanesulfonate (EMS), a direct-acting reference genotoxic agent, to which the bivalves were exposed for various times (24, 48 and 72 h). Bivalves were irradiated (single acute exposure) with 5 different doses (viz. 2, 4, 6, 8 and 10 Gy) of gamma radiation and their genotoxic effects on the haemocytes were studied using the comet assay. Haemolymph was collected from the adductor muscle at 24, 48 and 72 h of both EMS-exposed and irradiated bivalves and comet assay was carried out using standard protocol. A significant increase in DNA damage was observed as indicated by an increase in % tail DNA damage at different concentrations of EMS and all the doses of gamma radiation as compared to controls in

  10. Evaluation of γ-radiation-induced DNA damage in two species of bivalves and their relative sensitivity using comet assay

    Energy Technology Data Exchange (ETDEWEB)

    Praveen Kumar, M.K., E-mail: here.praveen@gmail.com [Department of Zoology, Goa University, Goa 403206 (India); Shyama, S.K., E-mail: skshyama@gmail.com [Department of Zoology, Goa University, Goa 403206 (India); Sonaye, B.S. [Department of Radiation Oncology, Goa Medical College, Goa (India); Naik, U Roshini; Kadam, S.B.; Bipin, P.D.; D’costa, A. [Department of Zoology, Goa University, Goa 403206 (India); Chaubey, R.C. [Radiation Biology and Health Science Division, Bhabha Atomic Research Centre, Mumbai (India)

    2014-05-01

    Highlights: • Possible genotoxic effect of accidental exposure of aquatic fauna to γ radiation. • Relative sensitivity of bivalves to γ radiation is also analyzed using comet assay. • γ radiation induced significant genetic damage in both the species of bivalves. • P. malabarica and M. casta exhibited a similar level of sensitivity to γ radiation. • Comet assay may be used as a biomarker for the environmental biomonitoring. - Abstract: Ionizing radiation is known to induce genetic damage in diverse groups of organisms. Under accidental situations, large quantities of radioactive elements get released into the environment and radiation emitted from these radionuclides may adversely affect both the man and the non-human biota. The present study is aimed (a) to know the genotoxic effect of gamma radiation on aquatic fauna employing two species of selected bivalves, (b) to evaluate the possible use of ‘Comet assay’ for detecting genetic damage in haemocytes of bivalves as a biomarker for environmental biomonitoring and also (c) to compare the relative sensitivity of two species of bivalves viz. Paphia malabarica and Meretrix casta to gamma radiation. The comet assays was optimized and validated using different concentrations (18, 32 and 56 mg/L) of ethyl methanesulfonate (EMS), a direct-acting reference genotoxic agent, to which the bivalves were exposed for various times (24, 48 and 72 h). Bivalves were irradiated (single acute exposure) with 5 different doses (viz. 2, 4, 6, 8 and 10 Gy) of gamma radiation and their genotoxic effects on the haemocytes were studied using the comet assay. Haemolymph was collected from the adductor muscle at 24, 48 and 72 h of both EMS-exposed and irradiated bivalves and comet assay was carried out using standard protocol. A significant increase in DNA damage was observed as indicated by an increase in % tail DNA damage at different concentrations of EMS and all the doses of gamma radiation as compared to controls in

  11. Gamma teletopography

    International Nuclear Information System (INIS)

    Simonet, G.

    1986-09-01

    To set the gamma activity cartography is an important element of safety in numerous cases: intervention in hot cell, search of a radioactive source, examination of radioactive waste circuit followed by a reprocessing definition of decontamination and decommissioning processes and for all other accidents. The device presented here is like a ''black box'' with an aperture and an emulsion photosensitive to the opposite; a classical film takes photography of the place; a X-ray type emulsion gives a spot more or less contrasted and extensive corresponding to each source. Images can be processed with a microprocessor [fr

  12. Gamma knife

    International Nuclear Information System (INIS)

    Kawamoto, Shunsuke; Takakura, Kintomo

    1991-01-01

    As to the gamma knife which is the radiation surgery device developed in Sweden a quarter century ago, its principle, structure, treatment techniques, already established clinical effect and the problems being left for hereafter are described. This treatment means supplements the operation under microscopes, and at present it takes the important position in neurosurgery, but hereafter, by the interdisciplinary cooperation of neurosurgery and clinical radiobiology, the more development can be expected. The method of irradiating the radiation of high dose selectively to a target region and breaking its tissue is called radiosurgery, and the device developed for this purpose is the gamma knife. First, it was applied to functional diseases, but good results were obtained by its application to auditory nerve and brain blood vessels, and it establishes the position as the safe treatment method of the morbid state in the deep part of brains, which is difficult to reach by operation. Accompanying the recent progress of the operation of skull base part, attention is paid to its application to various tumors in skull base. On the other hand, the radiosurgery combining a cyclotron or a linear accelerator with stereotaxic brain surgery is actively tried mainly to the deformation of brain blood vessels. (K.I.)

  13. Development of an integrated assay facility

    International Nuclear Information System (INIS)

    Molesworth, T.V.; Bailey, M.; Findlay, D.J.S.; Sene, M.R.; Swinhoe, M.T.

    1990-01-01

    Initial results of active neutron and active gamma-ray interrogation of a 500 liter cemented simulated CAGR intermediate level radioactive waste drum are described. The basis of the interrogation systems was the Harwell electron linear accelerator HELIOS, which was used to produce the interrogating neutrons and gamma-rays. Several sets of neutron detectors were located around the drum to count signature neutrons. The responses of the system were measured by placing known samples at many different locations within the drum. In general, measured responses confirmed calculated responses. Good agreement was obtained for the azimuthal angle dependences. The absolute responses agreed well for gamma-ray interrogation, but the calculations were apparently over-estimates for neutron interrogation. Those aspects requiring consideration in the practical application of assay techniques are identified. 8 refs., 6 figs

  14. Gamma scintigraphy in the evaluation of pharmaceutical dosage forms

    International Nuclear Information System (INIS)

    Davis, S.S.; Hardy, J.G.; Newman, S.P.; Wilding, I.R.

    1992-01-01

    Gamma-scintigraphy is applied extensively in the development and evaluation of pharmaceutical drug delivery systems. It is used particularly for monitoring formulations in the gastrointestinal and respiratory tracts. The radiolabelling is generally achieved by the incorporation of an appropriate technetium-99m or indium-111 labelled radiopharmaceutical into the formulation. In the case of complex dosage forms, such as enteric-coated tablets, labelling is best undertaken by the addition of a non-radioactive tracer such as samarium-152 or erbium-170 followed by neutron activation of the final product. Systems investigated include tablets and multiparticulates for oral administration, enemas and suppositories, metered dose inhalers and nebulisers, and nasal sprays and drops. Gamma-scintigraphy provides information on the deposition, dispersion and movement of the formulation. The combination of such studies with the assay of drug levels in blood or urine specimens, pharmacoscintigraphy, provides information concerning the sites of drug release and absorption. Data acquired from the scintigraphic evaluation of pharmaceutical dosage forms are now being used increasingly at all stages of product development, from the assessment of prototype delivery systems to supporting the product licence application. (orig.)

  15. Gamma scintigraphy in the evaluation of pharmaceutical dosage forms

    Energy Technology Data Exchange (ETDEWEB)

    Davis, S.S.; Hardy, J.G.; Newman, S.P.; Wilding, I.R. (Pharmaceutical Profiles Ltd., Nottingham (United Kingdom))

    1992-11-01

    Gamma-scintigraphy is applied extensively in the development and evaluation of pharmaceutical drug delivery systems. It is used particularly for monitoring formulations in the gastrointestinal and respiratory tracts. The radiolabelling is generally achieved by the incorporation of an appropriate technetium-99m or indium-111 labelled radiopharmaceutical into the formulation. In the case of complex dosage forms, such as enteric-coated tablets, labelling is best undertaken by the addition of a non-radioactive tracer such as samarium-152 or erbium-170 followed by neutron activation of the final product. Systems investigated include tablets and multiparticulates for oral administration, enemas and suppositories, metered dose inhalers and nebulisers, and nasal sprays and drops. Gamma-scintigraphy provides information on the deposition, dispersion and movement of the formulation. The combination of such studies with the assay of drug levels in blood or urine specimens, pharmacoscintigraphy, provides information concerning the sites of drug release and absorption. Data acquired from the scintigraphic evaluation of pharmaceutical dosage forms are now being used increasingly at all stages of product development, from the assessment of prototype delivery systems to supporting the product licence application. (orig.).

  16. Insecticidal and sterilizing effect of Olyset Duo®, a permethrin and pyriproxyfen mixture net against pyrethroid-susceptible and -resistant strains of Anopheles gambiae s.s.: a release-recapture assay in experimental huts

    Directory of Open Access Journals (Sweden)

    Djènontin Armel

    2015-01-01

    Full Text Available In the context of the widespread distribution of pyrethroid resistance among malaria vectors, we did a release-recapture trial in experimental huts to investigate the insecticidal and sterilizing effects of a novel long-lasting net (LN, Olyset® Duo, incorporating a mixture of permethrin (PER and the insect growth regulator (IGR, pyri-proxyfen (PPF. An LN containing PPF alone and a classic Olyset® Net were tested in parallel as positive controls. The effect of progressive number of holes (6, 30, or 150 that may accrue in nets over time was simulated. We used two laboratory Anopheles gambiae s.s. strains: the susceptible Kisumu strain and the pyrethroid-resistant VK-Per strain having solely kdr as resistance mechanism. The effect of these nets on the reproductive success of blood-fed females that survived the different LNs conditions was recorded. Regardless of the mosquito strain, the LNs containing PPF alone with as many as 30 holes drastically reduced the number of eggs laid by females succeeding in feeding, i.e. fecundity by 98% and egg hatching rate (fertility by 93% relative to untreated control net. Very few of the resistant females blood fed and survived under the Olyset® Duo with similar number of holes (up to 30 but of these few, the inhibition of reproductive success was 100%. There was no evidence that the Olyset® Duo LN with 150 holes impacted fecundity or fertility of the resistant colony. The efficacy of Olyset® Duo is encouraging and clearly illustrates that this new net might be a promising tool for malaria transmission control and resistance management.

  17. Insecticidal and sterilizing effect of Olyset Duo®, a permethrin and pyriproxyfen mixture net against pyrethroid-susceptible and -resistant strains of Anopheles gambiae s.s.: a release-recapture assay in experimental huts.

    Science.gov (United States)

    Djènontin, Armel; Ahoua Alou, Ludovic P; Koffi, Alphonsine; Zogo, Barnabas; Duarte, Elves; N'Guessan, Raphael; Moiroux, Nicolas; Pennetier, Cédric

    2015-01-01

    In the context of the widespread distribution of pyrethroid resistance among malaria vectors, we did a release-recapture trial in experimental huts to investigate the insecticidal and sterilizing effects of a novel long-lasting net (LN), Olyset® Duo, incorporating a mixture of permethrin (PER) and the insect growth regulator (IGR), pyri-proxyfen (PPF). An LN containing PPF alone and a classic Olyset® Net were tested in parallel as positive controls. The effect of progressive number of holes (6, 30, or 150) that may accrue in nets over time was simulated. We used two laboratory Anopheles gambiae s.s. strains: the susceptible Kisumu strain and the pyrethroid-resistant VK-Per strain having solely kdr as resistance mechanism. The effect of these nets on the reproductive success of blood-fed females that survived the different LNs conditions was recorded. Regardless of the mosquito strain, the LNs containing PPF alone with as many as 30 holes drastically reduced the number of eggs laid by females succeeding in feeding, i.e. fecundity by 98% and egg hatching rate (fertility) by 93% relative to untreated control net. Very few of the resistant females blood fed and survived under the Olyset® Duo with similar number of holes (up to 30) but of these few, the inhibition of reproductive success was 100%. There was no evidence that the Olyset® Duo LN with 150 holes impacted fecundity or fertility of the resistant colony. The efficacy of Olyset® Duo is encouraging and clearly illustrates that this new net might be a promising tool for malaria transmission control and resistance management. © A. Djènontin et al., published by EDP Sciences, 2015.

  18. Development of mass production, gamma sterilization and release of the codling moth, Laspeyresia pomonella L. Part of a coordinated programme on the use of the sterile male technique for control of lepidopterous insects attacking fruit and forest trees

    International Nuclear Information System (INIS)

    Suski, Z.W.

    1979-03-01

    Research on codling moths was conducted from Spring 1973 to Autumn 1978 and included rearing of larvae on thinning apples and artificial diet ecology, radiation sterilization and the effect of field releases of sterile moths in suppressing the wild population. Field releases of irradiated with 30 Krad unsexed insects were conducted in two consecutive seasons, namely in 1977 and 1978 and aimed at a sterile to wild ratio of 97:1 and 233:1 respectively. The experimentally obtained ratio, however, based on catches in traps baited with sex attractant was 24:1 and 79:1 respectively. Examination of fruit infestation at harvest revealed an increase in infestation by 9% in the 1977 sterile release programme and by 56% in the 1978 programme. Likely causes of the failure of the SIT programme were the immigration of fertile females from the surrounding area and inadequate mating competitiveness of the released moths due to somatic damage caused by the irradiation and laboratory adaptation. The sharp increase of fruit infestation in 1978 was very likely the result of a six fold increase in yield which provided a better chance of survival for hatching larvae

  19. Gamma camera

    International Nuclear Information System (INIS)

    Tschunt, E.; Platz, W.; Baer, U.; Heinz, L.

    1978-01-01

    A gamma camera has a plurality of exchangeable collimators, one of which is mounted in the ray inlet opening of the camera, while the others are placed on separate supports. The supports are swingably mounted upon a column one above the other through about 90 0 to a collimator exchange position. Each of the separate supports is swingable to a vertically aligned position, with limiting of the swinging movement and positioning of the support at the desired exchange position. The collimators are carried on the supports by means of a series of vertically disposed coil springs. Projections on the camera are movable from above into grooves of the collimator at the exchange position, whereupon the collimator is turned so that it is securely prevented from falling out of the camera head

  20. Saccharification of gamma-ray and alkali pretreated lignocellulosics

    International Nuclear Information System (INIS)

    Begum, A.; Choudhury, N.

    1988-01-01

    Enzymic saccharification of gamma ray and alkali pretreated sawdust, rice straw, and sugar cane bagasse showed higher release of reducing sugar from pretreated substrates. By gamma ray treatment alone (500 kGy) reducing sugar release of 2.8, 9.2, and 10 g/l was obtained from 7.5% (w/v) sawdust, rice straw, and bagasse and the same substrates showed reducing sugar release of 4.2, 30, and 20 g/l respectively when treated with alkali (0.1 g/g). Combination of gamma ray with alkali treatment further increased the reducing sugar release to 10.2, 33, and 36 g/l from sawdust, rice straw, and bagasse respectively. The effects of gamma ray and alkali treatment on saccharification varied with the nature of the substrate

  1. Radioactive wastes assay technique and equipment

    International Nuclear Information System (INIS)

    Lee, K. M.; Hong, D. S; Kim, T. K.; Bae, S. M.; Shon, J. S.; Hong, K. P.

    2004-12-01

    The waste inventory records such as the activities and radio- nuclides contained in the waste packages are to be submitted with the radioactive wastes packages for the final disposal. The nearly around 10,000 drums of waste stocked in KAERI now should be assayed for the preparation of the waste inventory records too. For the successive execution of the waste assay, the investigation into the present waste assay techniques and equipment are to be taken first. Also the installation of the waste assay equipment through the comprehensive design, manufacturing and procurement should be proceeded timely. As the characteristics of the KAERI-stocked wastes are very different from that of the nuclear power plant and those have no regular waste streams, the application of the in-direct waste assay method using the scaling factors are not effective for the KAERI-generated wastes. Considering for the versal conveniency including the accuracy over the wide range of waste forms and the combination of assay time and sensitivity, the TGS(Tomographic Gamma Scanner) is appropriate as for the KAERI -generated radioactive waste assay equipment

  2. Non destructive assay (NDA) techniques

    International Nuclear Information System (INIS)

    Mafra Guidicini, Olga; Llacer, Carlos D.; Rojo, Marcelo

    2001-01-01

    In the IAEA Safeguards System the basic verification method used is nuclear material accountancy, with containment and surveillance as important complementary measures. If nuclear material accountancy is to be effective, IAEA inspectors have to make independent measurements to verify declared material quantities. Most of the equipment available to the inspectors is designed to measure gamma rays and/or neutrons emitted by various nuclear materials. Equipment is also available to measure the gross weight of an item containing nuclear material. These types of measurement techniques are generally grouped under the title of nondestructive assay (NDA). The paper describes the NDA techniques and instruments used to verify the total amount of nuclear material held at a nuclear facility. (author)

  3. Gamma camera

    International Nuclear Information System (INIS)

    Conrad, B.; Heinzelmann, K.G.

    1975-01-01

    A gamma camera is described which obviates the distortion of locating signals generally caused by the varied light conductive capacities of the light conductors in that the flow of light through each light conductor may be varied by means of a shutter. A balancing of the flow of light through each of the individual light conductors, in effect, collective light conductors may be balanced on the basis of their light conductive capacities or properties, so as to preclude a distortion of the locating signals caused by the varied light conductive properties of the light conductors. Each light conductor has associated therewith two, relative to each other, independently adjustable shutters, of which one forms a closure member and the other an adjusting shutter. In this embodiment of the invention it is thus possible to block all of the light conductors leading to a photoelectric transducer, with the exception of those light conductors which are to be balanced. The balancing of the individual light conductors may then be obtained on the basis of the output signals of the photoelectric transducer. (auth)

  4. Gamma ray generator

    Science.gov (United States)

    Firestone, Richard B; Reijonen, Jani

    2014-05-27

    An embodiment of a gamma ray generator includes a neutron generator and a moderator. The moderator is coupled to the neutron generator. The moderator includes a neutron capture material. In operation, the neutron generator produces neutrons and the neutron capture material captures at least some of the neutrons to produces gamma rays. An application of the gamma ray generator is as a source of gamma rays for calibration of gamma ray detectors.

  5. Gadolinium-Based GaN for Neutron Detection with Gamma Discrimination

    Science.gov (United States)

    2016-06-01

    Gadolinium-Based GaN for Neutron Detection with Gamma Discrimination Distribution Statement A. Approved for public release; distribution is...Final Technical Report BRBAA08-Per5-Y-1-2-0030 Title: “Gadolinium-Based GaN for Neutron Detection with Gamma Discrimination ” Grant...Analysis  .............................................................................................  23   6.   Gamma-ray Discrimination

  6. Neutron gamma competition in fast fission

    International Nuclear Information System (INIS)

    Frehaut, J.

    1989-01-01

    In the present paper we analyse the data we have obtained on the distribution of the gamma-ray energy per fission, as well as on the average energy E-barγ released per fission for the neutron induced fission of several isotopes, in the energy range up to 15 MeV. 6 refs, 9 figs

  7. Detection of radiation-induced apoptosis using the comet assay

    International Nuclear Information System (INIS)

    Wada, Seiichi; Kobayashi, Yasuhiko; Funayama, Tomoo; Yamamoto, Kazuo; Khoa, Tran Van; Natsuhori, Masahiro; Ito, Nobuhiko

    2003-01-01

    The electrophoresis pattern of apoptotic cells detected by the comet assay has a characteristic small head and spread tail. This image has been referred to as an apoptotic comet, but it has not been previously proven to be apoptotic cells by any direct method. In order to identify this image obtained by the comet assay as corresponding to an apoptotic cell, the frequency of appearance of apoptosis was examined using CHO-K1 and L5178Y cells which were exposed to gamma irradiation. As a method for detecting apoptosis, the terminal deoxynucleotidyl transferase mediated dUTP nick end labeling (TUNEL) assay was used. When the frequency of appearance of apoptotic cells following gamma irradiation was observed over a period of time, there was a significant increase in appearance of apoptosis when using the TUNEL assay. However, there was only a slight increase when using the comet assay. In order to verify the low frequency of appearance of apoptosis when using the comet assay, we attempted to use the TUNEL assay to satin the apoptotic comets detected in the comet assay. The apoptotic comets were TUNEL positive and the normal comets were TUNEL negative. This indicates that the apoptotic comets were formed from DNA fragments with 3'-hydroxy ends that are generated as cells undergo apoptosis. Therefore, it was understood that the characteristic pattern of apoptotic comets detected by the comet assay corresponds to cells undergoing apoptosis. (author)

  8. Two-site sandwich radioimmunoassay of human gamma interferon with monoclonal antibodies

    Energy Technology Data Exchange (ETDEWEB)

    Tanaka, E; Imai, M; Usuda, S; Tachibana, K; Okamoto, H; Ohike, Y; Nakamura, T; Miyakawa, Y; Mayumi, M [Jichi Medical School, Minamikawachi, Tochigi (Japan)

    1985-03-18

    Two monoclonal antibodies were raised against human gamma interferon (IFN-..gamma..) derived from E. coli harboring the recombinant cDNA for IFN-..gamma.., and one against a synthetic peptide representing its C-terminus amino acid sequence of 20 residues. The monoclonal antibody against the synthetic peptide reacted either with IFN-..gamma.. or the synthetic peptide. One monoclonal anti-IFN-..gamma.. did not react with the synthetic peptide, while the other showed a weak binding with the peptide. A 2-site '1-step' radioimmunoassay was developed. The assay was rapid with a sensitivity capable of detecting a few ng/ml of IFN-..gamma...

  9. VOLUMETRIC LEAD ASSAY

    International Nuclear Information System (INIS)

    Ebadian, M.A.; Dua, S.K.; Roelant, David; Kumar, Sachin

    2001-01-01

    This report describes a system for handling and radioassay of lead, consisting of a robot, a conveyor, and a gamma spectrometer. The report also presents a cost-benefit analysis of options: radioassay and recycling lead vs. disposal as waste

  10. X-Ray-Driven Gamma Emission

    International Nuclear Information System (INIS)

    Carroll, J. J.; Karamian, S. A.; Rivlin, L. A.; Zadernovsky, A. A.

    2001-01-01

    X-ray-driven gamma emission describes processes that may release nuclear energy in a 'clean' way, as bursts of incoherent or coherent gamma rays without the production of radioactive by-products. Over the past decade, studies in this area, as a part of the larger field of quantum nucleonics, have gained tremendous momentum. Since 1987 it has been established that photons could trigger gamma emission from a long-lived metastable nuclear excited state of one nuclide and it appears likely that triggering in other isotopes will be demonstrated conclusively in the near future. With these experimental results have come new proposals for the creation of collective and avalanche-like incoherent gamma-ray bursts and even for the ultimate light source, a gamma-ray laser. Obviously, many applications would benefit from controlled bursts of gamma radiation, whether coherent or not. This paper reviews the experimental results and concepts for the production of gamma rays, driven by externally produced X-rays

  11. Manual of dose evaluation from atmospheric releases

    Energy Technology Data Exchange (ETDEWEB)

    Shirvaikar, V V; Abrol, V [Health Physics Division, Bhabha Atomic Research Centre, Bombay (India)

    1978-07-01

    The problem of dose evaluation from atmospheric releases is reduced to simple arithmetic by giving tables of concentrations and time integrated concentrations for instantaneous plumes and long time (1 year), sector averaged plumes for distances upto 10 km, effective release heights of upto 200 m and the six Pasquill stability classes. Correction factors for decay, depletion due to deposition and rainout are also given. Inhalation doses, immersion doses and contamination levels can be obtained from these by using multiplicative factors tabulated for various isotopes of significance. Tables of external gamma doses from plume are given separately for various gamma energies. Tables are also given to evaluate external beta and gamma dose rates from contaminated surfaces. The manual also discusses the basic diffusion model relevant to the problem. (author)

  12. Methane release

    International Nuclear Information System (INIS)

    Seifert, M.

    1999-01-01

    The Swiss Gas Industry has carried out a systematic, technical estimate of methane release from the complete supply chain from production to consumption for the years 1992/1993. The result of this survey provided a conservative value, amounting to 0.9% of the Swiss domestic output. A continuation of the study taking into account new findings with regard to emission factors and the effect of the climate is now available, which provides a value of 0.8% for the target year of 1996. These results show that the renovation of the network has brought about lower losses in the local gas supplies, particularly for the grey cast iron pipelines. (author)

  13. Nondestructive assay instrument for measurement of plutonium in solutions

    International Nuclear Information System (INIS)

    Shirk, D.G.; Hsue, F.; Li, T.K.; Canada, T.R.

    1979-01-01

    A nondestructive assay (NDA) instrument that measures the 239 Pu content in solutions, using a passive gamma-ray spectroscopy technique, has been developed and installed in the LASL Plutonium Processing Facility. A detailed evaluation of this instrument has been performed. The results show that the instrument can routinely determine 239 Pu concentrations of 1 to 500 g/l with accuracies of 1 to 5% and assay times of 1 to 2 x 10 3 s

  14. Microbead agglutination based assays

    KAUST Repository

    Kodzius, Rimantas

    2013-01-21

    We report a simple and rapid room temperature assay for point-of-care (POC) testing that is based on specific agglutination. Agglutination tests are based on aggregation of microbeads in the presence of a specific analyte thus enabling the macroscopic observation. Such tests are most often used to explore antibody-antigen reactions. Agglutination has been used for protein assays using a biotin/streptavidin system as well as a hybridization based assay. The agglutination systems are prone to selftermination of the linking analyte, prone to active site saturation and loss of agglomeration at high analyte concentrations. We investigated the molecular target/ligand interaction, explaining the common agglutination problems related to analyte self-termination, linkage of the analyte to the same bead instead of different microbeads. We classified the agglutination process into three kinds of assays: a two- component assay, a three-component assay and a stepped three- component assay. Although we compared these three kinds of assays for recognizing DNA and protein molecules, the assay can be used for virtually any molecule, including ions and metabolites. In total, the optimized assay permits detecting analytes with high sensitivity in a short time, 5 min, at room temperature. Such a system is appropriate for POC testing.

  15. Recent achievements in the field of gamma-ray bursts

    International Nuclear Information System (INIS)

    Lu Tan; Dai Zigao

    2001-01-01

    Recent progresses in the field of gamma-ray bursts is briefly introduced. Gamma-ray bursts are the most energetic explosion since the Big Bang of the universe. Within a few tens of seconds, the energy released in gamma-ray bursts could be several hundred times larger than that released form the sun in its whole life (about 10 billion years). The authors will first briefly discuss the observational facts, based on which the authors will discuss the standard fireball model, the dynamical behavior and evolution of gamma-ray bursts and their afterglows. Then, various observational phenomena that contradict the standard model are given and the importance of these post-standard effects are pointed out. The questions related to the energy source of gamma-ray bursts are still unanswered, and other important questions also remain to be solved

  16. Release of RANKERN 16A

    Directory of Open Access Journals (Sweden)

    Bird Adam

    2017-01-01

    Full Text Available RANKERN 16 is the latest version of the point-kernel gamma radiation transport Monte Carlo code from AMEC Foster Wheeler’s ANSWERS Software Service. RANKERN is well established in the UK shielding community for radiation shielding and dosimetry assessments. Many important developments have been made available to users in this latest release of RANKERN. The existing general 3D geometry capability has been extended to include import of CAD files in the IGES format providing efficient full CAD modelling capability without geometric approximation. Import of tetrahedral mesh and polygon surface formats has also been provided. An efficient voxel geometry type has been added suitable for representing CT data. There have been numerous input syntax enhancements and an extended actinide gamma source library. This paper describes some of the new features and compares the performance of the new geometry capabilities.

  17. Release of RANKERN 16A

    Science.gov (United States)

    Bird, Adam; Murphy, Christophe; Dobson, Geoff

    2017-09-01

    RANKERN 16 is the latest version of the point-kernel gamma radiation transport Monte Carlo code from AMEC Foster Wheeler's ANSWERS Software Service. RANKERN is well established in the UK shielding community for radiation shielding and dosimetry assessments. Many important developments have been made available to users in this latest release of RANKERN. The existing general 3D geometry capability has been extended to include import of CAD files in the IGES format providing efficient full CAD modelling capability without geometric approximation. Import of tetrahedral mesh and polygon surface formats has also been provided. An efficient voxel geometry type has been added suitable for representing CT data. There have been numerous input syntax enhancements and an extended actinide gamma source library. This paper describes some of the new features and compares the performance of the new geometry capabilities.

  18. Radioreceptor opioid assay

    International Nuclear Information System (INIS)

    Miller, R.J.; Chang, K.-J.

    1981-01-01

    A radioreceptor assay is described for assaying opioid drugs in biological fluids. The method enables the assay of total opioid activity, being specific for opioids as a class but lacking specificity within the class. A radio-iodinated opioid and the liquid test sample are incubated with an opiate receptor material. The percentage inhibition of the binding of the radio-iodinated compound to the opiate receptor is calculated and the opioid activity of the test liquid determined from a standard curve. Examples of preparing radio-iodinated opioids and assaying opioid activity are given. A test kit for the assay is described. Compared to other methods, this assay is cheap, easy and rapid. (U.K.)

  19. Absolute nuclear material assay

    Science.gov (United States)

    Prasad, Manoj K [Pleasanton, CA; Snyderman, Neal J [Berkeley, CA; Rowland, Mark S [Alamo, CA

    2010-07-13

    A method of absolute nuclear material assay of an unknown source comprising counting neutrons from the unknown source and providing an absolute nuclear material assay utilizing a model to optimally compare to the measured count distributions. In one embodiment, the step of providing an absolute nuclear material assay comprises utilizing a random sampling of analytically computed fission chain distributions to generate a continuous time-evolving sequence of event-counts by spreading the fission chain distribution in time.

  20. The glucose oxidase-peroxidase assay for glucose

    Science.gov (United States)

    The glucose oxidase-peroxidase assay for glucose has served as a very specific, sensitive, and repeatable assay for detection of glucose in biological samples. It has been used successfully for analysis of glucose in samples from blood and urine, to analysis of glucose released from starch or glycog...

  1. Evaluation of the Erythrocyte Malondialdehyde (MDA) Release Assay.

    Science.gov (United States)

    1987-01-01

    MDA vs. Cholesterol A It.M U Control indicated that there was alsc: a p-sit ive .. r i Piat i r, 0.58) between cholestetol an’] I I asma ::im E...N Engl J Med 310, 1209-1212(1984). 58. Hess AF. Involvement of the blood and blood vessels in infantile scurvy. Proc Soc Exp Biol Med 11, 130-132

  2. Cosmic gamma bursts

    International Nuclear Information System (INIS)

    Ehstulin, I.V.

    1980-01-01

    A brief consideration is being given to the history of cosmic gamma burst discovery and modern knowledge of their properties. The time dependence of gamma bursts is described and their possible sources are discussed

  3. Test plan for Digface Chemical and Radiation Assay System

    International Nuclear Information System (INIS)

    Akers, D.W.

    1993-07-01

    The Digface Chemical and Radiation Assay System (CRAS) Project will develop a sensor using Prompt Gamma Neutron Activation Analysis (PGNAA) that can detect the present of hazardous chemicals and radioactive materials. The CRAS is being designed for in situ assay of closed drums and contaminated soils for gamma-ray emitting radionuclides and hazardous elements. The CRAS is based upon the use of 252 Cf PGNAA with a germanium gamma-ray spectrometer as the analyzer. Tasks being performed include determining detection limits for a number of hazardous chemicals and assessing matrix and transmission effects through soil. Initial analyses suggest that the technique is applicable to a number of hazardous materials such as trichloroethane and carbon tetrachloride

  4. Gamma ray astronomy

    International Nuclear Information System (INIS)

    Broomhead, Laurent.

    1980-01-01

    The nuclear gamma astronomy is presented, in particular the Gamma Ray Observatory, an enormous eight tonnes machine fitted with gamma telescopes, scheduled for launching around 1985. It is thereby hoped to study the natural nuclear reactions which occur when stars explode [fr

  5. Endogenous Locus Reporter Assays.

    Science.gov (United States)

    Liu, Yaping; Hermes, Jeffrey; Li, Jing; Tudor, Matthew

    2018-01-01

    Reporter gene assays are widely used in high-throughput screening (HTS) to identify compounds that modulate gene expression. Traditionally a reporter gene assay is built by cloning an endogenous promoter sequence or synthetic response elements in the regulatory region of a reporter gene to monitor transcriptional activity of a specific biological process (exogenous reporter assay). In contrast, an endogenous locus reporter has a reporter gene inserted in the endogenous gene locus that allows the reporter gene to be expressed under the control of the same regulatory elements as the endogenous gene, thus more accurately reflecting the changes seen in the regulation of the actual gene. In this chapter, we introduce some of the considerations behind building a reporter gene assay for high-throughput compound screening and describe the methods we have utilized to establish 1536-well format endogenous locus reporter and exogenous reporter assays for the screening of compounds that modulate Myc pathway activity.

  6. A sensitive assay for Staphylococcus aureus nucleases

    Energy Technology Data Exchange (ETDEWEB)

    Kohli, J K; Vakil, B V; Patil, M S; Pandey, V N; Pradhan, D S [Bhabha Atomic Reserach Centre, Bombay (India). Biochemistry Div.

    1989-10-01

    A sensitive assay for staphylococcal nuclease involving incubation of the enzyme sample with heat-denatured ({sup 3}H) thymidine labelled DNA from E.coli, precipitation with trichloroacetic acid and measurement of the radioactivity of acid-soluble nucleotides released has been developed. The assay is sensitive enough to be used for comparing the levels of nucleases elaborated by different strains of S. aureus as well as for determining the extent of contamination of S. aureus in food and water samples even at levels at which the conventional spectrophotometric and toluidine blue-DNA methods are totally inadequate. (author). 26 refs., 3 figs ., 3 tabs.

  7. High Energy Neutron Induced Gamma Production

    International Nuclear Information System (INIS)

    Brown, D.A.; Johnson, M.; Navratil, P.

    2007-01-01

    N Division has an interest in improving the physics and accuracy of the gamma data it provides to its customers. It was asked to look into major gamma producing reactions for 14 MeV incident neutrons for several low-Z materials and determine whether LLNL's processed data files faithfully represent the current state of experimental and theoretical knowledge for these reactions. To address this, we surveyed the evaluations of the requested materials, made recommendations for the next ENDL release and noted isotopes that will require further experimental study. This process uncovered several major problems in our translation and processing of the ENDF formatted evaluations, most of which have been resolved

  8. Pharmacological evidences for DFK167-sensitive presenilin-independent gamma-secretase-like activity.

    Science.gov (United States)

    Sevalle, Jean; Ayral, Erwan; Hernandez, Jean-François; Martinez, Jean; Checler, Frédéric

    2009-07-01

    Amyloid-beta (Abeta) peptides production is thought to be a key event in the neurodegenerative process ultimately leading to Alzheimer's disease (AD) pathology. A bulk of studies concur to propose that the C-terminal moiety of Abeta is released from its precursor beta-amyloid precursor protein by a high molecular weight enzymatic complex referred to as gamma-secretase, that is composed of at least, nicastrin (NCT), Aph-1, Pen-2, and presenilins (PS) 1 or 2. They are thought to harbor the gamma-secretase catalytic activity. However, several lines of evidence suggest that additional gamma-secretase-like activities could potentially contribute to Abeta production. By means of a quenched fluorimetric substrate (JMV2660) mimicking the beta-amyloid precursor protein sequence targeted by gamma-secretase, we first show that as expected, this probe allows monitoring of an activity detectable in several cell systems including the neuronal cell line telencephalon specific murine neurons (TSM1). This activity is reduced by DFK167, N-[N-(3,5-difluorophenacetyl)-L-alanyl]-S-phenylglycine t-butyl ester (DAPT), and LY68458, three inhibitors known to functionally interact with PS. Interestingly, JMV2660 but not the unrelated peptide JMV2692, inhibits Abeta production in an in vitrogamma-secretase assay as expected from a putative substrate competitor. This activity is enhanced by PS1 and PS2 mutations known to be responsible for familial forms of AD and reduced by aspartyl mutations inactivating PS or in cells devoid of PS or NCT. However, we clearly establish that residual JMV2660-hydrolysing activity could be recovered in PS- and NCT-deficient fibroblasts and that this activity remained inhibited by DFK167. Overall, our study describes the presence of a proteolytic activity displaying gamma-secretase-like properties but independent of PS and still blocked by DFK167, suggesting that the PS-dependent complex could not be the unique gamma-secretase activity responsible for Abeta

  9. Development of food preservation and processing techniques by radiation - Studies on the safety and consumer acceptance of gamma irradiated meats

    Energy Technology Data Exchange (ETDEWEB)

    Kang, Il Jun; Lee, Young Jin; Lee, Young Sook; Kim, Ha Kyung [Hallym University, Chunchon (Korea)

    2000-04-01

    Gamma irradiation was applied to chickens for evaluation of their possible genotoxicity, acute toxicity, four-week oral toxicity and nutritional safety. The results were negative in the bacterial reversion assay with S. typhimurium TA98, TA100, TA1535, TA1537. Clastogenic effects of the irradiated samples tested were not shown in vivo mouse micronucleus assay and in chromosomal aberration tests with CHL cells. In an acute toxicity test, the maximal dose of 5,000 mg/kg did not change any toxic parameter examined in this study. In four-week oral toxicity study, appearance, behavior, mortality, food and water consumption of mouse of treated groups were not affected during the experimental periods(four-weeks). In urine analysis, in hematological examination as well as in serum biochemical experiment, no significant differences were found between the control and treatment groups. Although minor changes in some hematological and biochemical parameters were observed, they were in the normal range and were not dose dependent. In nutritional safety, the proximate composition of foods were not significantly changed by irradiation dose. No significant difference in the components of fatty acids were observed by gamma irradiation. In general, the amount of released free amino acid was not significantly changed by gamma irradiation. There was no difference in total amino acid content between non irradiated and irradiated samples. The SDS electrophoresis patterns of samples were not significantly different between nonirradiated and irradiated samples. The major mineral compositions of chicken were phosphorus, potassium, sodium, magnesium. The content of mineral was not significantly changed by gamma irradiation. 58 refs., 11 figs., 16 tabs. (Author)

  10. Test procedure for boxed waste assay system

    International Nuclear Information System (INIS)

    Wachter, J.

    1994-01-01

    This document, prepared by Los Alamos National Laboratory's NMT-4 group, details the test methodology and requirements for Acceptance/Qualification testing of a Boxed Waste Assay System (BWAS) designed and constructed by Pajarito Scientific Corporation. Testing of the BWAS at the Plutonium Facility (TA55) at Los Alamos National Laboratory will be performed to ascertain system adherence to procurement specification requirements. The test program shall include demonstration of conveyor handling capabilities, gamma ray energy analysis, and imaging passive/active neutron accuracy and sensitivity. Integral to these functions is the system's embedded operating and data reduction software

  11. Recent advances in segmented gamma scanner analysis

    International Nuclear Information System (INIS)

    Sprinkle, J.K. Jr.; Hsue, S.T.

    1987-01-01

    The segmented gamma scanner (SGS) is used in many facilities to assay low-density scrap and waste generated in the facilities. The procedures for using the SGS can cause a negative bias if the sample does not satisfy the assumptions made in the method. Some process samples do not comply with the assumptions. This paper discusses the effect of the presence of lumps on the SGS assay results, describes a method to detect the presence of lumps, and describes an approach to correct for the lumps. Other recent advances in SGS analysis are also discussed

  12. Reactor gamma spectrometry: status

    International Nuclear Information System (INIS)

    Gold, R.; Kaiser, B.J.

    1979-01-01

    Current work is described for Compton Recoil Gamma-Ray Spectrometry including developments in experimental technique as well as recent reactor spectrometry measurements. The current status of the method is described concerning gamma spectromoetry probe design and response characteristics. Emphasis is given to gamma spectrometry work in US LWR and BR programs. Gamma spectrometry in BR environments are outlined by focussing on start-up plans for the Fast Test Reactor (FTR). Gamma spectrometry results are presented for a LWR pressure vessel mockup in the Poolside Critical Assembly (PCA) at Oak Ridge National Laboratory

  13. Field experience with a mobile tomographic nondestructive assay system

    International Nuclear Information System (INIS)

    Prettyman, T.H.; Betts, S.E.; Taggart, D.P.; Estep, R.J.; Nicholas, N.J.; Lucas, M.C.; Harlan, R.A.

    1995-01-01

    A mobile tomographic gamma-ray scanner (TGS) developed by Los Alamos National Laboratory was recently demonstrated at the Rocky Flats Environmental Technology Site and is currently in use at Los Alamos waste storage areas. The scanner was developed to assay radionuclides in low-level, transuranic, and mixed waste in containers ranging in size from 2 ft 3 boxes to 83-gallon overpacks. The tomographic imaging capability provides a complete correction for source distribution and matrix attenuation effects, enabling accurate assays of Pu-239 and other gamma-ray emitting isotopes. In addition, the system can reliably detect self-absorbing material such as plutonium metal shot, and can correct for bias caused by self-absorption. The system can be quickly configured to execute far-field scans, segmented gamma-ray scans, and a host of intermediate scanning protocols, enabling higher throughput (up to 20 drums per 8-hour shift). In this paper, we will report on the results of field trials of the mobile system at Rocky Flats and Los Alamos. Assay accuracy is confirmed for cases in which TGS assays can be compared with assays (e.g. with calorimetry) of individual packages within the drums. The mobile tomographic technology is expected to considerably reduce characterization costs at DOE production and environmental technology sites

  14. Solid phase assays

    International Nuclear Information System (INIS)

    Reese, M.G.; Johnson, L.R.; Ransom, D.K.

    1980-01-01

    In a solid phase assay for quantitative determination of biological and other analytes, a sample such as serum is contacted with a receptor for the analyte being assayed, the receptor being supported on a solid support. No tracer for the analyte is added to the sample before contacting with the receptor; instead the tracer is contacted with the receptor after unbound analyte has been removed from the receptor. The assay can be otherwise performed in a conventional manner but can give greater sensitivity. (author)

  15. GammaWorkshops Proceedings

    International Nuclear Information System (INIS)

    Ramebaeck, H.; Straelberg, E.; Klemola, S.; Nielsen, Sven P.; Palsson, S.E.

    2012-01-01

    Due to a sparse interaction during the last years between practioners in gamma ray spectrometry in the Nordic countries, a NKS activity was started in 2009. This GammaSem was focused on seminars relevant to gamma spectrometry. A follow up seminar was held in 2010. As an outcome of these activities it was suggested that the 2011 meeting should be focused on practical issues, e.g. different corrections needed in gamma spectrometric measurements. This three day's meeting, GammaWorkshops, was held in September at Risoe-DTU. Experts on different topics relevant for gamma spectrometric measurements were invited to the GammaWorkshops. The topics included efficiency transfer, true coincidence summing corrections, self-attenuation corrections, measurement of natural radionuclides (natural decay series), combined measurement uncertainty calculations, and detection limits. These topics covered both lectures and practical sessions. The practical sessions included demonstrations of tools for e.g. corrections and calculations of the above meantioned topics. (Author)

  16. Relationship between the radioisotopic footpad assay and other immunological assays in tumor bearing rats

    International Nuclear Information System (INIS)

    Mizushima, Yutaka; Takeichi, Noritoshi; Minami, Akio; Kasai, Masaharu; Itaya, Toshiyuki

    1981-01-01

    KMT-17, a fibrosarcoma induced by 3-methylcholanthrene in a WKA rat, is a sensitive tumor to various kinds of immunological assays and is a suitable model tumor for the study of the immune status in tumor bearing hosts. The antitumor immune response of KMT-17 bearing rats was studied by a radioisotopic footpad assay (FPA) in comparison with other in vivo and in vitro assays. Delayed hypersensitivity to tumor antigens measured by the FPA was observed from the 8th day after transplantation of KMT-17 cells, reached a peak on the 12 - 15th day, and then declined in the late stage on the 17th day. The kinetics of the FPA correlated well with those of an in vivo Winn assay and of an in vitro lymphocyte cytotoxicity assay ( 51 Cr-release assay). The appearance of an antitumor antibody detected by a complement dependent cytotoxicity test also correlated well with the kinetics of the FPA. A growth inhibition assay (GIA) for non-specific cell-mediated immunity also showed similar kinetics to that of the FPA. The delayed hypersensitivity footpad reaction to tumor cell extracts measured by this FPA was tumor-specific. These results suggest that the FPA is a simple and reliable in vivo assay for evaluating antitumor immunity in tumor bearing hosts. (author)

  17. Spreadsheet analysis of gamma spectra for nuclear material measurements

    International Nuclear Information System (INIS)

    Mosby, W.R.; Pace, D.M.

    1990-01-01

    A widely available commercial spreadsheet package for personal computers is used to calculate gamma spectra peak areas using both region of interest and peak fitting methods. The gamma peak areas obtained are used for uranium enrichment assays and for isotopic analyses of mixtures of transuranics. The use of spreadsheet software with an internal processing language allows automation of routine analysis procedures increasing ease of use and reducing processing errors while providing great flexibility in addressing unusual measurement problems. 4 refs., 9 figs

  18. Radioimmune assay of human platelet prostaglandin synthetase

    International Nuclear Information System (INIS)

    Roth, G.J.; Machuga, E.T.

    1982-01-01

    Normal platelet function depends, in part, on platelet PG synthesis. PG synthetase (cyclo-oxygenase) catalyzes the first step in PG synthesis, the formation of PGH 2 from arachidonic acid. Inhibition of the enzyme by ASA results in an abnormality in the platelet release reaction. Patients with pparent congenital abnormalities in the enzyme have been described, and the effects have been referred to as ''aspirin-like'' defects of the platelet function. These patients lack platelet PG synthetase activity, but the actual content of PG synthetase protein in these individuals' platelets is unknown. Therefore an RIA for human platelet PG synthetase would provide new information, useful in assessing the aspirin-like defects of platelet function. An RIA for human platelet PG synthetase is described. The assay utilizes a rabbit antibody directed against the enzyme and [ 125 I]-labelled sheep PG synthetase as antigen. The human platelet enzyme is assayed by its ability to inhibit precipitation of the [ 125 I]antigen. The assay is sensitive to 1 ng of enzyme. By the immune assay, human platelets contain approximately 1200 ng of PG synethetase protein per 1.5 mg of platelet protein (approximately 10 9 platelets). This content corresponds to 10,000 enzyme molecules per platelet. The assay provides a rapid and convenient assay for the human platelet enzyme, and it can be applied to the assessment of patients with apparent platelet PG synthetase (cyclo-oxygenase) deficiency

  19. Factor IX assay

    Science.gov (United States)

    ... this page: //medlineplus.gov/ency/article/003679.htm Factor IX assay To use the sharing features on ... M. is also a founding member of Hi-Ethics and subscribes to the principles of the Health ...

  20. Factor VIII assay

    Science.gov (United States)

    ... this page: //medlineplus.gov/ency/article/003678.htm Factor VIII assay To use the sharing features on ... M. is also a founding member of Hi-Ethics and subscribes to the principles of the Health ...

  1. Factor II assay

    Science.gov (United States)

    ... this page: //medlineplus.gov/ency/article/003674.htm Factor II assay To use the sharing features on ... M. is also a founding member of Hi-Ethics and subscribes to the principles of the Health ...

  2. Factor VII assay

    Science.gov (United States)

    ... this page: //medlineplus.gov/ency/article/003676.htm Factor VII assay To use the sharing features on ... M. is also a founding member of Hi-Ethics and subscribes to the principles of the Health ...

  3. Microbead agglutination based assays

    KAUST Repository

    Kodzius, Rimantas; Castro, David; Foulds, Ian G.; Parameswaran, Ash M.; Sumanpreet, K. Chhina

    2013-01-01

    We report a simple and rapid room temperature assay for point-of-care (POC) testing that is based on specific agglutination. Agglutination tests are based on aggregation of microbeads in the presence of a specific analyte thus enabling

  4. Nondestructive assay of HTGR fuel rods

    International Nuclear Information System (INIS)

    Menlove, H.O.

    1974-01-01

    Performance characteristics of three different radioactive source NDA systems are compared for the assay of HTGR fuel rods and stacks of rods. These systems include the fast neutron Sb-Be assay system, the 252 Cf ''Shuffler,'' and the thermal neutron PAPAS assay system. Studies have been made to determinethe perturbation on the measurements from particle size, kernel Th/U ratio, thorium content, and hydrogen content. In addition to the total 235 U determination, the pellet-to-pellet or rod-to-rod uniformity of HTGR fuel rod stacks has been measured by counting the delayed gamma rays with a NaI through-hole in the PAPAS system. These measurements showed that rod substitutions can be detected easily in a fuel stack, and that detailed information is available on the loading variations in a uniform stack. Using a 1.0 mg 252 Cf source, assay rates of 2 to 4 rods/s are possible, thus facilitating measurement of 100 percent of a plant's throughput. (U.S.)

  5. The use of calorimetry for plutonium assay

    International Nuclear Information System (INIS)

    Mason, J.A.

    1982-12-01

    Calorimetry is a technique for measuring the thermal power of heat-producing substances. The technique may be applied to the measurement of plutonium-bearing materials which evolve heat as a result of alpha and beta decay. A calorimetric measurement of the thermal power of a plutonium sample, combined with a knowledge or measurement of the plutonium isotopic mass ratios of the sample provides a convenient and accurate, non-destructive measure of the total plutonium mass of the sample. The present report provides a description, and an assessment of the calorimetry technique applied to the assay of plutonium-bearing materials. Types and characteristics of plutonium calorimeters are considered, as well as calibration and operating procedures. The instrumentation used with plutonium calorimeters is described and the use of computer control for calorimeter automation is discussed. A critical review and assessment of plutonium calorimetry literature since 1970 is presented. Both fuel element and plutonium-bearing material calorimeters are considered. The different types of plutonium calorimeters are evaluated and their relative merits are discussed. A combined calorimeter and gamma-ray measurement assay system is considered. The design principles of plutonium assay calorimeters are considered. An automatic, computer-based calorimeter control system is proposed in conjunction with a general plutonium assay calorimeter design. (author)

  6. Degradation study of Durolon polycarbonate submitted to gamma radiation

    International Nuclear Information System (INIS)

    Miranda, A.; Sciani, V.

    1992-01-01

    The effect of gamma radiation from a cobalt 60 source in the 27000 Durolon polycarbonate irradiated with doses between 0,2 and 1000 kGy at 25 0 C was analyzed. For this reason the samples was submitted to the mechanical assay of tension, deformation and hardness and optical assay of transmittance. The obtained results show a good mechanical stability of the polycarbonate, when it was submitted to gamma irradiation in doses up to 20 kGy. (C.G.C.). 05 refs., 04 figs

  7. Analytical applications of neutron capture gamma-rays

    International Nuclear Information System (INIS)

    Lindstrom, R.M.; Paul, R.L.; Anderson, D.L.; Paul, R.L.

    1997-01-01

    Field and industrial applications of neutron capture gamma-ray spectrometry with isotopic sources or neutron generators are economically important. Geochemical exploration in boreholes is done routinely with neutron probes. Coal and ores are assayed with analyzers adjacent to a conveyor belt in dozens of industrial facilities. The use of capture gamma rays for explosives detection has been described in the literature, both for scanning airline baggage and for characterizing obsolete munitions; a packaged system for the latter is available commercially. Generalizations are drawn from the history of the field, and predictions are made about the future usefulness of capture gamma rays. (author)

  8. Dibasic calcium phosphate dihydrate, USP material compatibility with gamma radiation

    Science.gov (United States)

    Betancourt Quiles, Maritza

    Gamma radiation is a commonly used method to reduce the microbial bioburden in compatible materials when it is applied at appropriate dose levels. Gamma irradiation kills bacteria and mold by breaking down the organism’s DNA and inhibiting cell division. The purpose of this study is to determine the radiation dosage to be used to treat Dibasic Calcium Phosphate Dihydrate, USP (DCPD) and to evaluate its physicochemical effects if any, on this material. This material will be submitted to various doses of gamma radiation that were selected based on literature review and existing regulations that demonstrate that this method is effective to reduce or eliminate microbial bioburden in natural source and synthetic materials. Analytical testing was conducted to the DCPD exposed material in order to demonstrate that gamma radiation does not alter the physicochemical properties and material still acceptable for use in the manufacture of pharmaceutical products. The results obtained through this study were satisfactory and demonstrated that the gamma irradiation dosages from 5 to 30 kGy can be applied to DCPD without altering its physicochemical properties. These are supported by the Assay test data evaluation of lots tested before and after gamma irradiation implementation that show no significant statistical difference between irradiated and non irradiated assay results. The results of this study represent an achievement for the industry since they provide as an alternative the use of Gamma irradiation technology to control the microbial growth in DCPD.

  9. Computer-determined assay time based on preset precision

    International Nuclear Information System (INIS)

    Foster, L.A.; Hagan, R.; Martin, E.R.; Wachter, J.R.; Bonner, C.A.; Malcom, J.E.

    1994-01-01

    Most current assay systems for special nuclear materials (SNM) operate on the principle of a fixed assay time which provides acceptable measurement precision without sacrificing the required throughput of the instrument. Waste items to be assayed for SNM content can contain a wide range of nuclear material. Counting all items for the same preset assay time results in a wide range of measurement precision and wastes time at the upper end of the calibration range. A short time sample taken at the beginning of the assay could optimize the analysis time on the basis of the required measurement precision. To illustrate the technique of automatically determining the assay time, measurements were made with a segmented gamma scanner at the Plutonium Facility of Los Alamos National Laboratory with the assay time for each segment determined by counting statistics in that segment. Segments with very little SNM were quickly determined to be below the lower limit of the measurement range and the measurement was stopped. Segments with significant SNM were optimally assays to the preset precision. With this method the total assay time for each item is determined by the desired preset precision. This report describes the precision-based algorithm and presents the results of measurements made to test its validity

  10. Antigen-Specific IP-10 Release Is a Sensitive Biomarker of Mycobacterium bovis Infection in Cattle.

    Directory of Open Access Journals (Sweden)

    Sven D C Parsons

    Full Text Available The most widely used ante-mortem diagnostic tests for tuberculosis in cattle are the tuberculin skin test and the interferon-gamma (IFN-γ release assay, both of which measure cell-mediated immune responses to Mycobacterium bovis infection. However, limitations in the performance of these tests results in a failure to identify all infected animals. In attempting to increase the range of diagnostic tests for tuberculosis, measurement of the cytokine IP-10 in antigen-stimulated blood has previously been shown to improve the detection of M. tuberculosis and M. bovis infection, in humans and African buffaloes (Syncerus caffer, respectively. In the present study, 60 cattle were identified by the single intradermal comparative tuberculin test as tuberculosis reactors (n = 24 or non-reactors (n = 36 and the release of IFN-γ and IP-10 in antigen-stimulated whole blood from these animals was measured using bovine specific ELISAs. There was a strong correlation between IP-10 and IFN-γ production in these samples. Moreover, measurement of the differential release of IP-10 in response to stimulation with M. bovis purified protein derivative (PPD and M. avium PPD distinguished between reactor and non-reactor cattle with a sensitivity of 100% (95% CI, 86%-100% and a specificity of 97% (95% CI, 85%-100%. These results suggest that IP-10 might prove valuable as a diagnostic biomarker of M. bovis infection in cattle.

  11. Gamma Splines and Wavelets

    Directory of Open Access Journals (Sweden)

    Hannu Olkkonen

    2013-01-01

    Full Text Available In this work we introduce a new family of splines termed as gamma splines for continuous signal approximation and multiresolution analysis. The gamma splines are born by -times convolution of the exponential by itself. We study the properties of the discrete gamma splines in signal interpolation and approximation. We prove that the gamma splines obey the two-scale equation based on the polyphase decomposition. to introduce the shift invariant gamma spline wavelet transform for tree structured subscale analysis of asymmetric signal waveforms and for systems with asymmetric impulse response. Especially we consider the applications in biomedical signal analysis (EEG, ECG, and EMG. Finally, we discuss the suitability of the gamma spline signal processing in embedded VLSI environment.

  12. Waste assay measurement integration system user interface

    International Nuclear Information System (INIS)

    Mousseau, K.C.; Hempstead, A.R.; Becker, G.K.

    1995-01-01

    The Waste Assay Measurement Integration System (WAMIS) is being developed to improve confidence in and lower the uncertainty of waste characterization data. There are two major components to the WAMIS: a data access and visualization component and a data interpretation component. The intent of the access and visualization software is to provide simultaneous access to all data sources that describe the contents of any particular container of waste. The visualization software also allows the user to display data at any level from raw to reduced output. Depending on user type, the software displays a menuing hierarchy, related to level of access, that allows the user to observe only those data sources s/he has been authorized to view. Access levels include system administrator, physicist, QA representative, shift operations supervisor, and data entry. Data sources are displayed in separate windows and presently include (1) real-time radiography video, (2) gamma spectra, (3) passive and active neutron, (4) radionuclide mass estimates, (5) total alpha activity (Ci), (6) container attributes, (7) thermal power (w), and (8) mass ratio estimates for americium, plutonium, and uranium isotopes. The data interpretation component is in the early phases of design, but will include artificial intelligence, expert system, and neural network techniques. The system is being developed on a Pentium PC using Microsoft Visual C++. Future generations of WAMIS will be UNIX based and will incorporate more generically radiographic/tomographic, gamma spectroscopic/tomographics, neutron, and prompt gamma measurements

  13. Assay method and compositions

    International Nuclear Information System (INIS)

    1977-01-01

    Methods are described for measuring catecholamine levels in human and animal body fluids and tissues using the catechol-O-methyl-transferase (COMT) radioassay. The assay involves incubating the biological sample with COMT and the tritiated methyl donor, S-adenosyl-L-methionine( 3 H)-methyl. The O-methylated ( 3 H) epinephrine and/or norepinephrine are extracted and oxidised to vanillin- 3 H which in turn is extracted and its radioactivity counted. When analysing dopamine levels the assay is extended by vanillin- 3 H and raising the pH of the aqueous periodate phase from which O-methylated ( 3 H) dopamine is extracted and counted. The assay may be modified depending on whether measurements of undifferentiated total endogenous catecholamine levels or differential analyses of the catecholamine levels are being performed. The sensitivity of the assay can be as low as 5 picograms for norepinephrine and epinephrine and 12 picograms for dopamine. The assemblance of the essential components of the assay into a kit for use in laboratories is also described. (U.K.)

  14. The self-absorption effect of gamma rays in 239Pu

    International Nuclear Information System (INIS)

    Hsiaohua Hsu

    1989-01-01

    Nuclear materials assay with gamma-ray spectrum measurement is a well-established method for safeguards. However, for a thick source, the self-absorption of characteristic low-energy gamma rays has been a handicap to accurate assay. The author has carried out Monte Carlo simulations to study this effect using the 239 Pu α-decay gamma-ray spectrum as an example. The thickness of a plutonium metal source can be considered a function of gamma-ray intensity ratios. In a practical application, gamma-ray intensity ratios can be obtained from a measured spectrum. With the help of calculated curves, scientists can find the source thickness and make corrections to gamma-ray intensities, which then lead to an accurate quantitative determination of radioactive isotopes in the material

  15. Gamma ray astronomy

    International Nuclear Information System (INIS)

    Fichtel, C.E.

    1975-01-01

    The first certain detection of celestial high energy gamma rays came from a satellite experiment flown on the third Orbiting Solar Observatory (OSO-111). A Gamma ray spark chamber telescope with substantively greater sensitivity and angular resolution (a few degrees) flown on the second Small Astronomy Satellite (SAS-II) has now provided a better picture of the gamma ray sky, and particularly the galactic plane and pulsars. This paper will summarize the present picture of gamma ray astronomy as it has developed at this conference from measurements made with experiments carried out on balloons, those remaining on the ground, and ones flown on satellites. (orig.) [de

  16. Comparison of destructive and nondestructive assay of heterogeneous salt residues

    International Nuclear Information System (INIS)

    Fleissner, J.G.; Hume, M.W.

    1986-01-01

    To study problems associated with nondestructive assay (NDA) measurements of molten salt residues, a joint study was conducted by the Rocky Flats Plant, Golden, CO and Mound Laboratories, Miamisburg, OH. Extensive NDA measurements were made on nine containers of molten salt residues by both Rocky Flats and Mound followed by dissolution and solution quantification at Rocky Flats. Results of this study verify that plutonium and americium can be measured in such salt residues by a new gamma-ray spectral analysis technique coupled with calorimetry. Biases with respect to the segmented gamma-scan technique were noted

  17. Vanderbilt University Gamma Irradiation of Nano-modified Concrete (2017 Milestone Report)

    Energy Technology Data Exchange (ETDEWEB)

    Deichert, Geoffrey G. [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); Linton, Kory D. [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); Terrani, Kurt A. [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); Selby, Aaron P. [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); Reches, Yonathan [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States)

    2017-08-01

    This document outlines the irradiation of concrete specimens in the Gamma Irradiation Facility in the High Flux Isotope Reactor (HFIR) at Oak Ridge National Laboratory (ORNL). Two gamma irradiation runs were performed in July of 2017 on 18 reference mortar bar specimens, 26 reference cement paste bar specimens, and 28 reference cement paste tab specimens to determine the dose and temperature response of the specimens in the gamma irradiation environment. Specimens from the first two gamma irradiations were surveyed and released to Vanderbilt University. The temperature and dose information obtained informs the test parameters of the final two gamma irradiations of nano-modified concrete planned for FY 2018.

  18. Rover waste assay system

    Energy Technology Data Exchange (ETDEWEB)

    Akers, D.W.; Stoots, C.M.; Kraft, N.C.; Marts, D.J. [Idaho National Engineering Lab., Idaho Falls, ID (United States)

    1997-11-01

    The Rover Waste Assay System (RWAS) is a nondestructive assay system designed for the rapid assay of highly-enriched {sup 235}U contaminated piping, tank sections, and debris from the Rover nuclear rocket fuel processing facility at the Idaho Chemical Processing Plant. A scanning system translates a NaI(Tl) detector/collimator system over the structural components where both relative and calibrated measurements for {sup 137}Cs are made. Uranium-235 concentrations are in operation and is sufficiently automated that most functions are performed by the computer system. These functions include system calibration, problem identification, collimator control, data analysis, and reporting. Calibration of the system was done through a combination of measurements on calibration standards and benchmarked modeling. A description of the system is presented along with the methods and uncertainties associated with the calibration and analysis of the system for components from the Rover facility. 4 refs., 2 figs., 4 tabs.

  19. Rover waste assay system

    International Nuclear Information System (INIS)

    Akers, D.W.; Stoots, C.M.; Kraft, N.C.; Marts, D.J.

    1997-01-01

    The Rover Waste Assay System (RWAS) is a nondestructive assay system designed for the rapid assay of highly-enriched 235 U contaminated piping, tank sections, and debris from the Rover nuclear rocket fuel processing facility at the Idaho Chemical Processing Plant. A scanning system translates a NaI(Tl) detector/collimator system over the structural components where both relative and calibrated measurements for 137 Cs are made. Uranium-235 concentrations are in operation and is sufficiently automated that most functions are performed by the computer system. These functions include system calibration, problem identification, collimator control, data analysis, and reporting. Calibration of the system was done through a combination of measurements on calibration standards and benchmarked modeling. A description of the system is presented along with the methods and uncertainties associated with the calibration and analysis of the system for components from the Rover facility. 4 refs., 2 figs., 4 tabs

  20. Radioreceptor assay for insulin

    Energy Technology Data Exchange (ETDEWEB)

    Suzuki, Kazuo [Tokyo Univ. (Japan). Faculty of Medicine

    1975-04-01

    Radioreceptor assay of insulin was discussed from the aspects of the measuring method, its merits and problems to be solved, and its clinical application. Rat liver 10 x g pellet was used as receptor site, and enzymatic degradation of insulin by the system contained in this fraction was inhibited by adding 1 mM p-CMB. /sup 125/I-labelled porcine insulin was made by lactoperoxidase method under overnight incubation at 4/sup 0/C and later purification by Sephadex G-25 column and Whatman CF-11 cellulose powder. Dog pancreatic vein serum insulin during and after the glucose load was determined by radioreceptor assay and radioimmunoassay resulting that both measurements accorded considerably. Radioreceptor assay would clarify the pathology of disorders of glucose metabolism including diabetes.

  1. Evaluation of Gamma Interferon and Antibody Tuberculosis Tests in Alpacas

    Science.gov (United States)

    Holder, Tom; Clifford, Derek; Dexter, Ian; Brewer, Jacky; Smith, Noel; Waring, Laura; Crawshaw, Tim; Gillgan, Steve; Lyashchenko, Konstantin; Lawrence, John; Clarke, John; de la Rua-Domenech, Ricardo; Vordermeier, Martin

    2012-01-01

    We describe the performance of cell-based and antibody blood tests for the antemortem diagnosis of tuberculosis (TB) in South American camelids (SAC). The sensitivity and specificity of the gamma interferon (IFN-γ) release assay, two lateral flow rapid antibody tests (Stat-Pak and Dual Path Platform [DPP]), and two enzyme-linked immunosorbent assay (ELISA)-based antibody tests (Idexx and Enferplex) were determined using diseased alpacas from Mycobacterium bovis culture-confirmed breakdown herds and TB-free alpacas from geographical areas with no history of bovine TB, respectively. Our results show that while the sensitivities of the IFN-γ and antibody tests were similar (range of 57.7% to 66.7%), the specificity of the IFN-γ test (89.1%) was lower than those of any of the antibody tests (range of 96.4% to 97.4%). This lower specificity of the IFN-γ test was at least in part due to undisclosed Mycobacterium microti infection in the TB-free cohort, which stimulates a positive purified protein derivative (PPD) response. The sensitivity of infection detection could be increased by combining two antibody tests, but even the use of all four antibody tests failed to detect all diseased alpacas. These antibody-negative alpacas were IFN-γ positive. We found that the maximum sensitivity could be achieved only by the combination of the IFN-γ test with two antibody tests in a “test package,” although this resulted in decreased specificity. The data from this evaluation of tests with defined sensitivity and specificity provide potential options for antemortem screening of SAC for TB in herd breakdown situations and could also find application in movement testing and tracing investigations. PMID:22914362

  2. Clonogenic assay: adherent cells.

    Science.gov (United States)

    Rafehi, Haloom; Orlowski, Christian; Georgiadis, George T; Ververis, Katherine; El-Osta, Assam; Karagiannis, Tom C

    2011-03-13

    The clonogenic (or colony forming) assay has been established for more than 50 years; the original paper describing the technique was published in 1956. Apart from documenting the method, the initial landmark study generated the first radiation-dose response curve for X-ray irradiated mammalian (HeLa) cells in culture. Basically, the clonogenic assay enables an assessment of the differences in reproductive viability (capacity of cells to produce progeny; i.e. a single cell to form a colony of 50 or more cells) between control untreated cells and cells that have undergone various treatments such as exposure to ionising radiation, various chemical compounds (e.g. cytotoxic agents) or in other cases genetic manipulation. The assay has become the most widely accepted technique in radiation biology and has been widely used for evaluating the radiation sensitivity of different cell lines. Further, the clonogenic assay is commonly used for monitoring the efficacy of radiation modifying compounds and for determining the effects of cytotoxic agents and other anti-cancer therapeutics on colony forming ability, in different cell lines. A typical clonogenic survival experiment using adherent cells lines involves three distinct components, 1) treatment of the cell monolayer in tissue culture flasks, 2) preparation of single cell suspensions and plating an appropriate number of cells in petri dishes and 3) fixing and staining colonies following a relevant incubation period, which could range from 1-3 weeks, depending on the cell line. Here we demonstrate the general procedure for performing the clonogenic assay with adherent cell lines with the use of an immortalized human keratinocyte cell line (FEP-1811). Also, our aims are to describe common features of clonogenic assays including calculation of the plating efficiency and survival fractions after exposure of cells to radiation, and to exemplify modification of radiation-response with the use of a natural antioxidant

  3. Scintillation proximity assay

    International Nuclear Information System (INIS)

    Hart, H.

    1980-01-01

    In a method of immunological assay two different classes of particles which interact at short distances to produce characteristic detectable signals are employed in a modification of the usual latex fixation test. In one embodiment an aqueous suspension of antigen coated tritiated latex particles (LH) and antigen coated polystyrene scintillant particles (L*) is employed to assay antibody in the aqueous medium. The amount of (LH) (L*) dimer formation and higher order aggregation induced and therefore the concentration of antibody (or antigen) present which caused the aggregation can be determined by using standard liquid scintillation counting equipment. (author)

  4. Assays for calcitonin receptors

    International Nuclear Information System (INIS)

    Teitelbaum, A.P.; Nissenson, R.A.; Arnaud, C.D.

    1985-01-01

    The assays for calcitonin receptors described focus on their use in the study of the well-established target organs for calcitonin, bone and kidney. The radioligand used in virtually all calcitonin binding studies is 125 I-labelled salmon calcitonin. The lack of methionine residues in this peptide permits the use of chloramine-T for the iodination reaction. Binding assays are described for intact bone, skeletal plasma membranes, renal plasma membranes, and primary kidney cell cultures of rats. Studies on calcitonin metabolism in laboratory animals and regulation of calcitonin receptors are reviewed

  5. Evaluation of a MTT assay in measurement of radiosensitizing effect

    International Nuclear Information System (INIS)

    Higuchi, Keiko; Mitsuhashi, Norio; Saitoh, Jun-ichi; Maebayashi, Katsuya; Sakurai, Hideyuki; Akimoto, Tetsuo; Niibe, Hideo

    1999-01-01

    The usefulness of a MTT assay by measuring the radiosensitizing effect of caffeine on rat yolk sac tumor cell line with a mutant-type p53 in vitro was evaluated. A rat yolk sac tumor cell line with a mutant-type p53, NMT-1R, was used in this study. The radiosensitivity of NMT-1R with or without caffeine was measured with a MTT assay. The results were compared with those by a clonogenic assay. Caffeine at a concentration of 2.0 mM which released radiation-induced G 2 block demonstrated a radiosensitizing effect, but caffeine at a concentration of 0.5 mM did not. The radiosensitizing effect of caffeine measured by a MTT assay correlated with that measured by a clonogenic assay. A MTT assay was useful to measure radiosensitivity and/or a radiosensitizing effect in vitro. (author)

  6. Antioxidant activity potential of gamma irradiated carrageenan

    International Nuclear Information System (INIS)

    Abad, Lucille V.; Relleve, Lorna S.; Racadio, Charles Darwin T.; Aranilla, Charito T.; De la Rosa, Alumanda M.

    2013-01-01

    The antioxidant capacity of irradiated κ-, ι-, λ-carrageenans were investigated using the hydroxyl radical scavenging assay, reducing power assay and DPPH radical scavenging capacity assay. The degree of oxidative inhibition increased with increasing concentration and dose. The type of carrageenan had also an influence on its antioxidant activity which followed the order of lambda< iota< kappa. Increase in oxidative property with radiation dose can be attributed mainly to the depolymerization of the carrageenans with corresponding increase in reducing sugar. The antioxidant properties of these carrageenan oligomers were lower than that of ascorbic acid and galactose sugar. - Highlights: • The antioxidant capacity of gamma irradiated κ-, ι-, λ-carrageenans increased with increasing concentration and dose. • The type of carrageenan had an influence on its antioxidant activity which followed the order of lambda< iota< kappa. • Increase in oxidative property with radiation dose can be attributed mainly to the depolymerization of the carrageenans with corresponding increase in reducing sugar

  7. Development of a quantitative bead capture assay for soluble IL-7 receptor alpha in human plasma.

    Directory of Open Access Journals (Sweden)

    Sylvie Faucher

    Full Text Available BACKGROUND: IL-7 is an essential cytokine in T-cell development and homeostasis. It binds to the IL-7R receptor, a complex of the IL-7Ralpha (CD127 and common gamma (CD132 chains. There is significant interest in evaluating the expression of CD127 on human T-cells as it often decreased in medical conditions leading to lymphopenia. Previous reports showed the usefulness of CD127 as a prognostic marker in viral infections such as HIV, CMV, EBV and HCV. A soluble CD127 (sCD127 is released in plasma and may contribute to disease pathogenesis through its control on IL-7 activities. Measuring sCD127 is important to define its role and may complement existing markers used in lymphopenic disease management. We describe a new quantitative assay for the measurement of sCD127 in plasma and report sCD127 concentrations in healthy adults. METHODOLOGY/PRINCIPAL FINDINGS: We developed a quantitative bead-based sCD127 capture assay. Polyclonal CD127-specific antibodies were chosen for capture and a biotinylated monoclonal anti-CD127 antibody was selected for detection. The assay can detect native sCD127 and recombinant sCD127 which served as the calibrator. The analytical performance of the assay was characterized and the concentration and stability of plasma sCD127 in healthy adults was determined. The assay's range was 3.2-1000 ng/mL. The concentration of plasma sCD127 was 164+/-104 ng/mL with over a log variation between subjects. Individual sCD127 concentrations remained stable when measured serially during a period of up to one year. CONCLUSIONS/SIGNIFICANCE: This is the first report on the quantification of plasma sCD127 in a population of healthy adults. Soluble CD127 plasma concentrations remained stable over time in a given individual and sCD127 immunoreactivity was resistant to repeated freeze-thaw cycles. This quantitative sCD127 assay is a valuable tool for defining the potential role of sCD127 in lymphopenic diseases.

  8. Correction for gamma-ray self-attenuation in regular heterogeneous materials

    International Nuclear Information System (INIS)

    Parker, J.L.

    1981-09-01

    A procedure for determining the total correction factor for gamma-ray self-attenuation in regular heterogeneous materials is derived and discussed. The result of a practical application of the procedure to the passive gamma-ray assay of the 235 U content of high-temperature gas reactor fuel is presented

  9. News/Press Releases

    Data.gov (United States)

    Office of Personnel Management — A press release, news release, media release, press statement is written communication directed at members of the news media for the purpose of announcing programs...

  10. Effects of gamma irradiation on antioxidants and ultraviolet stabilizers

    International Nuclear Information System (INIS)

    Kawamura, Yoko; Miura, Makiko; Miura, Yukiko; Yamada, Takashi

    1998-01-01

    The effects of gamma irradiation on 18 kinds of antioxidants and 10 kinds of ultraviolet stabilizers, intact or in a polyethylene sheet, were studied. After irradiating at a 30kGy dose, the content of additives themselves did not change and new degradation products were not found. While most antioxidants in polyethylene had a decreased content after irradiation, most ultraviolet stabilizers did not change. During the migration tests with aqueous food simulants, additives were not released from either irradiated or unirradiated sheets. For the migration tests with n-heptane, however, all additives were released from the unirradiated sheet, while most of the antioxidants were not released or released only slightly. (author)

  11. Lateral flow assays

    NARCIS (Netherlands)

    Posthuma-Trumpie, G.A.; Amerongen, van A.

    2012-01-01

    A simple version of immunochemical-based methods is the Lateral Flow Assay (LFA). It is a dry chemistry technique (reagents are included); the fluid from the sample runs through a porous membrane (often nitrocellulose) by capillary force. Typically the membrane is cut as a strip of 0.5*5 cm. In most

  12. Microchemiluminescent assay system

    Energy Technology Data Exchange (ETDEWEB)

    Kiel, J.L.

    1986-04-09

    The patent concerns a microchemiluminescent assay system, which can be used to detect ionizing radiation, heat or specific substances. The method involves the use of a complex formed from serum albumin and a luminescer which, in the presence of ionizing radiation (heat, or a specific analyte), will emit light in an amount proportional to the amount of radiation, etc. (U.K.).

  13. (MTT) dye reduction assay.

    African Journals Online (AJOL)

    to inhibit proliferation of HeLa cells was determined using the 3443- dimethylthiazol-2-yl)-2,5-diphenyl-tetrazolium bromide (MTT) dye reduction assay. Extracts from roots of Agathisanthemum bojeri, Synaptolepis kirkii and Zanha africana and the leaf extract of Physalis peruviana at a concentration of 10 pg/ml inhibited cell ...

  14. Hyaluronic Acid Assays

    DEFF Research Database (Denmark)

    Itenov, Theis S; Kirkby, Nikolai S; Bestle, Morten H

    2015-01-01

    BACKGROUD: Hyaluronic acid (HA) is proposed as a marker of functional liver capacity. The aim of the present study was to compare a new turbidimetric assay for measuring HA with the current standard method. METHODS: HA was measured by a particle-enhanced turbidimetric immunoassay (PETIA) and enzyme...

  15. FLUIDICS DEVICE FOR ASSAY

    DEFF Research Database (Denmark)

    2007-01-01

    The present invention relates to a device for use in performing assays on standard laboratory solid supports whereon chemical entities are attached. The invention furthermore relates to the use of such a device and a kit comprising such a device. The device according to the present invention is a...

  16. Gamma tomography apparatus

    International Nuclear Information System (INIS)

    Span, F.J.

    1988-01-01

    The patent concerns a gamma tomography apparatus for medical diagnosis. The apparatus comprises a gamma scintillation camera head and a suspension system for supporting and positioning the camera head with respect for the patient. Both total body scanning and single photon emission tomography can be carried out with the apparatus. (U.K.)

  17. Gamma-sterilization

    International Nuclear Information System (INIS)

    Lindgren, E.

    1974-01-01

    The author makes a survey of his experience in sterilization and sterility control of medical products. At present three different methods are used, steamsterilization, gassterilizing and gammasterilizing. The investments and costs for gamma radiation is presented and a comparison of the costs for gamma- and gassterilization including sterility control is made. (M.S.)

  18. Gamma-ray sources

    International Nuclear Information System (INIS)

    Hermsen, W.

    1980-01-01

    Results are presented from an analysis of the celestial gamma-ray fine-scale structure based on over half of the data which may ultimately be available from the COS-B satellite. A catalogue consisting of 25 gamma-ray sources measured at energies above 100 MeV is presented. (Auth.)

  19. Gamma ray astronomy

    International Nuclear Information System (INIS)

    Hillier, R.

    1984-01-01

    The book reviews the development of gamma ray astronomy over the past twenty five years. A large section of the book is devoted to the problems of background radiation and the design of detectors. Gamma rays from the sun, the galactic disc, the galaxy, and extra galactic sources; are also discussed. (U.K.)

  20. Gamma ray bursts of black hole universe

    Science.gov (United States)

    Zhang, T. X.

    2015-07-01

    Slightly modifying the standard big bang theory, Zhang recently developed a new cosmological model called black hole universe, which has only a single postulate but is consistent with Mach's principle, governed by Einstein's general theory of relativity, and able to explain existing observations of the universe. In the previous studies, we have explained the origin, structure, evolution, expansion, cosmic microwave background radiation, quasar, and acceleration of black hole universe, which grew from a star-like black hole with several solar masses through a supermassive black hole with billions of solar masses to the present state with hundred billion-trillions of solar masses by accreting ambient matter and merging with other black holes. This study investigates gamma ray bursts of black hole universe and provides an alternative explanation for the energy and spectrum measurements of gamma ray bursts according to the black hole universe model. The results indicate that gamma ray bursts can be understood as emissions of dynamic star-like black holes. A black hole, when it accretes its star or merges with another black hole, becomes dynamic. A dynamic black hole has a broken event horizon and thus cannot hold the inside hot (or high-frequency) blackbody radiation, which flows or leaks out and produces a GRB. A star when it collapses into its core black hole produces a long GRB and releases the gravitational potential energy of the star as gamma rays. A black hole that merges with another black hole produces a short GRB and releases a part of their blackbody radiation as gamma rays. The amount of energy obtained from the emissions of dynamic star-like black holes are consistent with the measurements of energy from GRBs. The GRB energy spectra derived from this new emission mechanism are also consistent with the measurements.

  1. Nondestructive assay of plutonium residue in horizontal storage tanks

    International Nuclear Information System (INIS)

    Marsh, S.F.

    1985-01-01

    Aqueous plutonium recovery and purification processes often involve the temporary storage of plutonium solutions in holding tanks. Because plutonium is known to precipitate from aqueous solutions under certain conditions, there is a continuing need to assay emptied tanks for plutonium residue. A portable gamma spectrometer system, specifically designed for this purpose, provides rapid assay of such plutonium residues in horizontal storage tanks. A means is thus available for the nondestructive analysis of these tanks on a regular schedule to ensure that significant deposits of plutonium are not allowed to accumulate. 5 figs

  2. LSDS Development for Isotopic Fissile Content Assay

    International Nuclear Information System (INIS)

    Lee, Yong Deok; Park, Chang Je; Park, Geun Il; Lee, Jung Won; Song, Kee Chan

    2010-01-01

    Concerning the sustainable energy supply and green house effect, nuclear energy became the most feasible option to meet the energy demand in Korea. However, the production of the spent nuclear fuel is the inevitable situation. Since the first nuclear power plant started to produce the electricity in Korea, the accumulated amount of spent fuels exceeded 10k tomes recently. The accumulation of the spent fuels is the big issue in the society. Therefore, as an option which strengthens the nuclear proliferation resistance and reduces the amount of spent fuels, sodium fast reactor (SFR) program linked with pyro-processing is under development to re-use the PWR spent fuel and produce the energy. In the process, the produced metallic material involves uranium and TRU (transuranic; neptunium, plutonium, and americium). The uranium-TRU is used to fabricate SFR fuel. The burning the recycled fuel in the reactor is to solve the current spent fuel storage problem and to minimize the actinides accumulation having long half-life. Generally, the spent fuel from PWR has unburned ∼1 % U235, produced ∼0.5 % plutonium from decay chain, ∼3 % fission products, ∼ 0.1 % minor actinides (MA) and uranium remainder. About 1.5 % fissile materials still exist in the spent fuel. Therefore, spent fuel is not only waste but energy resource. The direct and isotopic fissile content assay is the crucial technology for the spent fuel reuse. Additionally, the fissile content analysis will contribute to the optimum storage design and safe spent fuel management. Several nondestructive technologies have been developed for the spent fuel assay; gamma ray measurement, passive and active neutron measurements. Spent fuel emits intense gamma rays and neutrons by (a, n) and spontaneous fission. This intense background has the limitation on the direct analysis of fissile materials. Recently, to analyze the individual fissile content, leadslowing down spectrometer (LSDS) has been being developed in Korea

  3. Radioreceptor assay for oxyphenonium

    International Nuclear Information System (INIS)

    Ensing, K.; Zeeuw, R.A. de

    1984-01-01

    The development of a radioreceptor assay for the quaternary anticholinergic drug, oxyphenonium, in plasma is reported. It is based on competition between this drug and 3 H-dexetimide for binding to muscarinic receptors. After ion pair extraction and reextraction, the drug can be determined in plasma at concentrations down to a value of 100 pg/ml. This permits pharmacokinetic studies to be made after inhalation of oxyphenonium. (author)

  4. Dual isotope assays

    International Nuclear Information System (INIS)

    Smith, G.F.W.; Stevens, R.A.J.; Jacoby, B.

    1980-01-01

    Dual isotope assays for thyroid function are performed by carrying out a radio-immunoassay for two of thyroxine (T4), tri-iodothyronine (T3), thyroid stimulating hormone (TSH), and thyroxine binding globulin (TBG), by a method wherein a version of one of the thyroid components, preferably T4 or T3 is labelled with Selenium-75 and the version of the other thyroid component is labelled with a different radionuclide, preferably Iodine-125. (author)

  5. GammaWorkshops Proceedings

    Energy Technology Data Exchange (ETDEWEB)

    Ramebaeck, H. (ed.) (Swedish Defence Research Agency (Sweden)); Straalberg, E. (Institute for Energy Technology, Kjeller (Norway)); Klemola, S. (Radiation and Nuclear Safety Authority, STUK (Finland)); Nielsen, Sven P. (Technical Univ. of Denmark. Risoe National Lab. for Sustainable Energy, Roskilde (Denmark)); Palsson, S.E. (Icelandic Radiation Safety Authority (Iceland))

    2012-01-15

    Due to a sparse interaction during the last years between practioners in gamma ray spectrometry in the Nordic countries, a NKS activity was started in 2009. This GammaSem was focused on seminars relevant to gamma spectrometry. A follow up seminar was held in 2010. As an outcome of these activities it was suggested that the 2011 meeting should be focused on practical issues, e.g. different corrections needed in gamma spectrometric measurements. This three day's meeting, GammaWorkshops, was held in September at Risoe-DTU. Experts on different topics relevant for gamma spectrometric measurements were invited to the GammaWorkshops. The topics included efficiency transfer, true coincidence summing corrections, self-attenuation corrections, measurement of natural radionuclides (natural decay series), combined measurement uncertainty calculations, and detection limits. These topics covered both lectures and practical sessions. The practical sessions included demonstrations of tools for e.g. corrections and calculations of the above meantioned topics. (Author)

  6. The distribution and abundance of gamma emitting radionuclides in Lake Ontario sediments

    International Nuclear Information System (INIS)

    McKinley, R.S.

    1985-03-01

    The distribution of gamma emitting radionuclides in Lake Ontario sediments was investigated. Samples were collected using a systematic design in the vicinity of Pickering and Darlington, and supplemented by lakewide offshore samples. Naturally occurring 40 K was the predominant source of gamma activity. 60 Co was the only potentially CANDU released radionuclide which showed a distributional association with the Pickering 'A' NGS discharge

  7. The gamma function

    CERN Document Server

    Artin, Emil

    2015-01-01

    This brief monograph on the gamma function was designed by the author to fill what he perceived as a gap in the literature of mathematics, which often treated the gamma function in a manner he described as both sketchy and overly complicated. Author Emil Artin, one of the twentieth century's leading mathematicians, wrote in his Preface to this book, ""I feel that this monograph will help to show that the gamma function can be thought of as one of the elementary functions, and that all of its basic properties can be established using elementary methods of the calculus."" Generations of teachers

  8. Pu-238 assay performance with the Canberra IQ3 system

    Energy Technology Data Exchange (ETDEWEB)

    Booth, L.; Gillespie, B.; Seaman, G.

    1997-11-01

    Canberra Industries has recently completed a demonstration project at the Westinghouse Savannah River Site (WSRC) to characterize 55-gallon drums containing Pu-238 contaminated waste. The goal of this project was to detect and quantify Pu-238 contaminated waste. The goal of this project was to detect and quantify Pu-238 waste to detection limits of less than 50 nCi/g using gamma assay techniques. This would permit reclassification of these drums from transuranic (TRU) waste to low-level waste (LLW). The instrument used for this assay was a Canberra IQ3 high sensitivity gamma assay system, mounted in a trailer. The results of the measurements demonstrate achievement of detection levels as low as 1 nCi/g for low density waste drums, and good correlation with known concentrations in several test drums. In addition, the data demonstrates significant advantages for using large area low-energy germanium detectors for achieving the lowest possible MDAs for gamma rays in the 80-250 keV range. 1 fig., 2 tabs.

  9. Interferon-gamma response to the treatment of active pulmonary and extra-pulmonary tuberculosis.

    Science.gov (United States)

    Liang, L; Shi, R; Liu, X; Yuan, X; Zheng, S; Zhang, G; Wang, W; Wang, J; England, K; Via, L E; Cai, Y; Goldfeder, L C; Dodd, L E; Barry, C E; Chen, R Y

    2017-10-01

    Interferon-gamma (IFN-γ) release assays (IGRAs) are used to diagnose tuberculosis (TB) but not to measure treatment response. To measure IFN-γ response to active anti-tuberculosis treatment. Patients from the Henan Provincial Chest Hospital, Henan, China, with TB symptoms and/or signs were enrolled into this prospective, observational cohort study and followed for 6 months of treatment, with blood and sputum samples collected at 0, 2, 4, 6, 8, 16 and 24 weeks. The QuantiFERON® TB-Gold assay was run on collected blood samples. Participants received a follow-up telephone call at 24 months to determine relapse status. Of the 152 TB patients enrolled, 135 were eligible for this analysis: 118 pulmonary (PTB) and 17 extra-pulmonary TB (EPTB) patients. IFN-γ levels declined significantly over time among all patients (P = 0.002), with this decline driven by PTB patients (P = 0.001), largely during the initial 8 weeks of treatment (P = 0.019). IFN-γ levels did not change among EPTB patients over time or against baseline culture or drug resistance status. After 6 months of effective anti-tuberculosis treatment, IFN-γ levels decreased significantly in PTB patients, largely over the initial 8 weeks of treatment. IFN-γ concentrations may offer some value for monitoring anti-tuberculosis treatment response among PTB patients.

  10. DNA repair in modeled microgravity: Double strand break rejoining activity in human lymphocytes irradiated with {gamma}-rays

    Energy Technology Data Exchange (ETDEWEB)

    Mognato, Maddalena, E-mail: maddalena.mognato@unipd.it [Dipartimento di Biologia, Universita di Padova, via U. Bassi 58 B, 35121 Padova (Italy); Girardi, Cristina; Fabris, Sonia [Dipartimento di Biologia, Universita di Padova, via U. Bassi 58 B, 35121 Padova (Italy); Celotti, Lucia [Dipartimento di Biologia, Universita di Padova, via U. Bassi 58 B, 35121 Padova (Italy); Laboratori Nazionali di Legnaro, INFN, Padova (Italy)

    2009-04-26

    Cell response to ionising radiation depends, besides on genetic and physiological features of the biological systems, on environmental conditions occurring during DNA repair. Many data showed that microgravity, experienced by astronauts during space flights or modeled on Earth, causes apoptosis, cytoskeletal alteration, cell growth inhibition, increased frequency of mutations and chromosome aberrations. In this study, we analysed the progression of the rejoining of double strand breaks (DSBs) in human peripheral blood lymphocytes (PBLs) irradiated with {gamma}-rays and incubated in static condition (1g) or in modeled microgravity (MMG). {gamma}-H2AX foci formation and disappearance, monitored during the repair incubation, showed that the kinetics of DSBs rejoining was different in the two gravity conditions. The fraction of foci-positive cells decreased slower in MMG than in 1g at 6 and 24 h after irradiation (P < 0.01) and the mean number of {gamma}-H2AX foci per nucleus was significantly higher in MMG than in 1g at the same time-points (P < 0.001). In the same samples we determined apoptotic level and the rate of DSB rejoining during post-irradiation incubation. A significant induction of apoptosis was observed in MMG at 24 h after irradiation (P < 0.001), whereas at shorter times the level of apoptosis was slightly higher in MMG respect to 1g. In accordance with the kinetics of {gamma}-H2AX foci, the slower rejoining of radiation-induced DSBs in MMG was observed by DNA fragmentation analyses during the repair incubation; the data of pulsed-field gel electrophoresis assay showed that the fraction of DNA released in the gel was significantly higher in PBL incubated in MMG after irradiation with respect to cells maintained in 1g. Our results provide evidences that MMG incubation during DNA repair delayed the rate of radiation-induced DSB rejoining, and increased, as a consequence, the genotoxic effects of ionising radiation.

  11. A Quantitative Fluorescence-Based Lipase Assay

    Directory of Open Access Journals (Sweden)

    Giovanna Lomolino

    2012-01-01

    Full Text Available An easy and fast gel diffusion assay for detecting and monitoring lipase activity by quantification of fluorescein is described. By measuring the intensity of fluorescein, it is possible to obtain a calibration curve with a regression coefficient better than by using the radius of fluorescent haloes. Through the quantification of fluorescence intensity of fluorescein released after the hydrolysis of a fluorescent ester, fluorescein dibutyrate, used as substrate in agar plates, commercial and skimmed milk lipase activity were studied. Moreover, with this method, lipase activity can be monitored in reaction medium that contains compounds which are affected by turbidity or cause measurement interference for UV-spectrophotometer and fluorimeter. In this experiment, boiled skimmed milk was dispersed in the agar gel with fluorescein dibutyrate, and it was used as a reaction medium to mimic natural conditions. The development of such an assay has a potential for applications in industries ranging from pharmaceuticals to food production and monitoring.

  12. Generation of laser Compton gamma-rays using Compact ERL

    International Nuclear Information System (INIS)

    Shizuma, Toshiyuki; Hajima, Ryoichi; Nagai, Ryoji; Hayakawa, Takehito; Mori, Michiaki; Seya, Michio

    2015-01-01

    Nondestructive isotope-specific assay system using nuclear resonance fluorescence has been developed at JAEA. In this system, intense, mono-energetic laser Compton scattering (LCS) gamma-rays are generated by combining an energy recovery linac (ERL) and laser enhancement cavity. As technical development for such an intense gamma-ray source, we demonstrated generation of LCS gamma-rays using Compact ERL (supported by the Ministry of Education, Culture, Sports, Science and Technology) developed in collaboration with KEK. We also measured X-ray fluorescence for elements near iron region by using mono-energetic LCS gamma-rays. In this presentation, we will show results of the experiment and future plan. (author)

  13. Accounting for segment correlations in segmented gamma-ray scans

    International Nuclear Information System (INIS)

    Sheppard, G.A.; Prettyman, T.H.; Piquette, E.C.

    1994-01-01

    In a typical segmented gamma-ray scanner (SGS), the detector's field of view is collimated so that a complete horizontal slice or segment of the desired thickness is visible. Ordinarily, the collimator is not deep enough to exclude gamma rays emitted from sample volumes above and below the segment aligned with the collimator. This can lead to assay biases, particularly for certain radioactive-material distributions. Another consequence of the collimator's low aspect ratio is that segment assays at the top and bottom of the sample are biased low because the detector's field of view is not filled. This effect is ordinarily countered by placing the sample on a low-Z pedestal and scanning one or more segment thicknesses below and above the sample. This takes extra time, however, We have investigated a number of techniques that both account for correlated segments and correct for end effects in SGS assays. Also, we have developed an algorithm that facilitates estimates of assay precision. Six calculation methods have been compared by evaluating the results of thousands of simulated, assays for three types of gamma-ray source distribution and ten masses. We will report on these computational studies and their experimental verification

  14. Basics of Gamma Ray Detection

    Energy Technology Data Exchange (ETDEWEB)

    Stinnett, Jacob [Los Alamos National Lab. (LANL), Los Alamos, NM (United States); Venkataraman, Ram [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States)

    2017-09-13

    The objective of this training is to explain the origin of x-rays and gamma rays, gamma ray interactions with matter, detectors and electronics used in gamma ray-spectrometry, and features of a gamma-ray spectrum for nuclear material that is safeguarded.

  15. Enzyme-linked immunospot: an alternative method for the detection of interferon gamma in Johne's disease

    DEFF Research Database (Denmark)

    Begg, Douglas J.; de Silva, Kumudika; Bosward, Katrina

    2009-01-01

    To date, the sensitivity of the interferon gamma (IFN-) enzyme-linked immunosorbent assay (ELISA) to detect Johne's disease (JD) has been poor, especially in the early stages of disease. To improve the sensitivity of IFN- detection in the early stages of infection, an alternate assay needs to be ...

  16. Arct'Alg release from hydrogel membranes

    International Nuclear Information System (INIS)

    Amaral, Renata H.; Rogero, Sizue O.; Shihomatsu, Helena M.; Lugao, Ademar B.

    2009-01-01

    The hydrogel properties make them attractive for a variety of biomedical and pharmaceutical applications, primarily in drug delivery system. Synthetic hydrogels have been studied to develop new devices for drugs or cosmetic active agents release. Arct'Alg R is an extract derived from red algae biomass which has antioxidant, anti-inflammatory and tissue regeneration stimulant properties. This extract was incorporated to poly(N-vinyl pyrrolidone) (PVP) and poly(vinyl alcohol) (PVA) hydrogel membranes obtained by gamma rays crosslinking technique. The ionizing radiation presents the advantage to occur polymerization and sterilization simultaneously in the same process. The aim of this work was the in vitro release kinetic study of Arct'Alg R from hydrogel membranes during 24 hours to verify the possibility of use in cosmetic and dermatological treatments. Results showed that about 50% and 30% of incorporated Arct'Alg R was released from PVP and PVA hydrogel membrane devices respectively. (author)

  17. GammaWorkshops Proceedings

    DEFF Research Database (Denmark)

    Strålberg, Elisabeth; Klemola, Seppo; Nielsen, Sven Poul

    to the GammaWorkshops. The topics included efficiency transfer, true coincidence summing corrections, self-attenuation corrections, measurement of natural radionuclides (natural decay series), combined measurement uncertainty calculations, and detection limits. These topics covered both lectures and practical...

  18. FTR europia gamma heating

    International Nuclear Information System (INIS)

    Ward, J.T. Jr.

    1975-01-01

    Calculated and experimental gamma heating rates of europia in the Engineering Mockup Critical Assembly (EMC) were correlated. A calculated to experimental (C/E) ratio of 1.086 was established in validating the theoretical approach and computational technique applied in the calculations. Gamma heat deposition rates in the FTR with Eu 2 O 3 control absorbers were determined from three-dimensional calculations. Maximum gamma heating was found to occur near the tip of a half-inserted row 5 control rod assembly--12.8 watts/gm of europia. Gamma heating profiles were established for a single half-inserted europia absorber assembly. Local heat peaking was found not to alter significantly heating rates computed in the FTR core model, where larger mesh interval sizes precluded examination of spatially-limited heating gradients. These computations provide the basis for thermal-hydraulic analyses to ascertain temperature profiles in the FTR under europia control

  19. Beta and Gamma Gradients

    DEFF Research Database (Denmark)

    Løvborg, Leif; Gaffney, C. F.; Clark, P. A.

    1985-01-01

    Experimental and/or theoretical estimates are presented concerning, (i) attenuation within the sample of beta and gamma radiation from the soil, (ii) the gamma dose within the sample due to its own radioactivity, and (iii) the soil gamma dose in the proximity of boundaries between regions...... of differing radioactivity. It is confirmed that removal of the outer 2 mm of sample is adequate to remove influence from soil beta dose and estimates are made of the error introduced by non-removal. Other evaluations include variation of the soil gamma dose near the ground surface and it appears...... that the present practice of avoiding samples above a depth of 0.3 m may be over-cautious...

  20. Gamma spectrometry today

    International Nuclear Information System (INIS)

    Hemingway, J.

    1990-01-01

    This paper reviews the important advances in gamma spectroscopy made in recent years. Improvements in detectors and other components and the addition of on-line computer control systems is discussed. (UK)

  1. Dynamic gamma knife radiosurgery

    International Nuclear Information System (INIS)

    Luan Shuang; Swanson, Nathan; Chen Zhe; Ma Lijun

    2009-01-01

    Gamma knife has been the treatment of choice for various brain tumors and functional disorders. Current gamma knife radiosurgery is planned in a 'ball-packing' approach and delivered in a 'step-and-shoot' manner, i.e. it aims to 'pack' the different sized spherical high-dose volumes (called 'shots') into a tumor volume. We have developed a dynamic scheme for gamma knife radiosurgery based on the concept of 'dose-painting' to take advantage of the new robotic patient positioning system on the latest Gamma Knife C(TM) and Perfexion(TM) units. In our scheme, the spherical high dose volume created by the gamma knife unit will be viewed as a 3D spherical 'paintbrush', and treatment planning reduces to finding the best route of this 'paintbrush' to 'paint' a 3D tumor volume. Under our dose-painting concept, gamma knife radiosurgery becomes dynamic, where the patient moves continuously under the robotic positioning system. We have implemented a fully automatic dynamic gamma knife radiosurgery treatment planning system, where the inverse planning problem is solved as a traveling salesman problem combined with constrained least-square optimizations. We have also carried out experimental studies of dynamic gamma knife radiosurgery and showed the following. (1) Dynamic gamma knife radiosurgery is ideally suited for fully automatic inverse planning, where high quality radiosurgery plans can be obtained in minutes of computation. (2) Dynamic radiosurgery plans are more conformal than step-and-shoot plans and can maintain a steep dose gradient (around 13% per mm) between the target tumor volume and the surrounding critical structures. (3) It is possible to prescribe multiple isodose lines with dynamic gamma knife radiosurgery, so that the treatment can cover the periphery of the target volume while escalating the dose for high tumor burden regions. (4) With dynamic gamma knife radiosurgery, one can obtain a family of plans representing a tradeoff between the delivery time and

  2. Dynamic gamma knife radiosurgery

    Energy Technology Data Exchange (ETDEWEB)

    Luan Shuang; Swanson, Nathan; Chen Zhe [Department of Computer Science, University of New Mexico, Albuquerque, NM 87131 (United States); Ma Lijun [Department of Radiation Oncology, University of California San Francisco, San Francisco, CA 94143 (United States)], E-mail: sluan@cs.unm.edu, E-mail: nate@cs.unm.edu, E-mail: zchen@cs.unm.edu, E-mail: lijunma@radonc.ucsf.edu

    2009-03-21

    Gamma knife has been the treatment of choice for various brain tumors and functional disorders. Current gamma knife radiosurgery is planned in a 'ball-packing' approach and delivered in a 'step-and-shoot' manner, i.e. it aims to 'pack' the different sized spherical high-dose volumes (called 'shots') into a tumor volume. We have developed a dynamic scheme for gamma knife radiosurgery based on the concept of 'dose-painting' to take advantage of the new robotic patient positioning system on the latest Gamma Knife C(TM) and Perfexion(TM) units. In our scheme, the spherical high dose volume created by the gamma knife unit will be viewed as a 3D spherical 'paintbrush', and treatment planning reduces to finding the best route of this 'paintbrush' to 'paint' a 3D tumor volume. Under our dose-painting concept, gamma knife radiosurgery becomes dynamic, where the patient moves continuously under the robotic positioning system. We have implemented a fully automatic dynamic gamma knife radiosurgery treatment planning system, where the inverse planning problem is solved as a traveling salesman problem combined with constrained least-square optimizations. We have also carried out experimental studies of dynamic gamma knife radiosurgery and showed the following. (1) Dynamic gamma knife radiosurgery is ideally suited for fully automatic inverse planning, where high quality radiosurgery plans can be obtained in minutes of computation. (2) Dynamic radiosurgery plans are more conformal than step-and-shoot plans and can maintain a steep dose gradient (around 13% per mm) between the target tumor volume and the surrounding critical structures. (3) It is possible to prescribe multiple isodose lines with dynamic gamma knife radiosurgery, so that the treatment can cover the periphery of the target volume while escalating the dose for high tumor burden regions. (4) With dynamic gamma knife radiosurgery, one can

  3. Development of a Radioactive Waste Assay System

    Energy Technology Data Exchange (ETDEWEB)

    Kang, Duck Won; Song, Myung Jae; Shin, Sang Woon; Sung, Kee Bang; Ko, Dae Hach [Korea Electric Power Research Institute, Taejon (Korea, Republic of); Kim, Kil Jeong; Park, Jong Mook; Jee, Kwang Yoong [Korea Atomic Energy Research Institute, Taejon (Korea, Republic of)

    1996-12-31

    Nuclear Act of Korea requires the manifest of low and intermediate level radioactive waste generated at nuclear power plants prior to disposal sites.Individual history records of the radioactive waste should be contained the information about the activity of nuclides in the drum, total activity, weight, the type of waste. A fully automated nuclide analysis assay system, non-destructive analysis and evaluation system of the radioactive waste, was developed through this research project. For the nuclides that could not be analysis directly by MCA, the activities of the representative {gamma}-emitters(Cs-137, Co-60) contained in the drum were measured by using that system. Then scaling factors were used to calculate the activities of {alpha}, {beta}-emitters. Furthermore, this system can automatically mark the analysis results onto the drum surface. An automated drum handling system developed through this research project can reduce the radiation exposure to workers. (author). 41 refs., figs.

  4. IMEF gamma scanning system

    Energy Technology Data Exchange (ETDEWEB)

    Baek, Sang Yeol; Park, Dae Kyu; Ahn, Sang Bok; Ju, Yong Sun; Jeon, Yong Bum

    1997-06-01

    The gamma scanning system which is installed in IMEF is the equipment obtaining the gamma ray spectrum from irradiated fuels. This equipment could afford the useful data relating spent fuels like as burn-up measurements. We describe the specifications of the equipment and its accessories, and also described its operation procedure so that an operator can use this report as the operation procedure. (author). 1 tab., 11 figs., 11 refs.

  5. IMEF gamma scanning system

    International Nuclear Information System (INIS)

    Baek, Sang Yeol; Park, Dae Kyu; Ahn, Sang Bok; Ju, Yong Sun; Jeon, Yong Bum.

    1997-06-01

    The gamma scanning system which is installed in IMEF is the equipment obtaining the gamma ray spectrum from irradiated fuels. This equipment could afford the useful data relating spent fuels like as burn-up measurements. We describe the specifications of the equipment and its accessories, and also described its operation procedure so that an operator can use this report as the operation procedure. (author). 1 tab., 11 figs., 11 refs

  6. Nondestructive techniques for assaying fuel debris in piping at Three Mile Island Unit 2

    International Nuclear Information System (INIS)

    Vinjamuri, K.; McIsaac, C.V.; Beller, L.S.; Isaacson, L.; Mandler, J.W.; Hobbins, R.R. Jr.

    1981-11-01

    Four major categories of nondestructive techniques - ultrasonic, passive gamma ray, infrared detection, and remote video examination - have been determined to be feasible for assaying fuel debris in the primary coolant system of the Three Mile Island Unit 2 (TMI-2) Reactor. Passive gamma ray detection is the most suitable technique for the TMI-2 piping; however, further development of this technique is needed for specific application to TMI-2

  7. Radiorespirometic assay device

    International Nuclear Information System (INIS)

    Levin, G.V.; Straat, P.A.

    1981-01-01

    A radiorespirometic assay device is described in which the presence of microorganisms in a sample is determined by placing the sample in contact with a metabolisable radioactive labelled substrate, collecting any gas evolved, exposing a photosensitive material to the gas and determining if a spot is produced on the material. A spot indicates the presence of radioactivity showing that the substrate has been metabolized by a microorganism. Bacteria may be detected in body fluids, hospital operating rooms, water, food, cosmetics and drugs. (U.K.)

  8. Radon assay for SNO+

    Energy Technology Data Exchange (ETDEWEB)

    Rumleskie, Janet [Laurentian University, Greater Sudbury, Ontario (Canada)

    2015-12-31

    The SNO+ experiment will study neutrinos while located 6,800 feet below the surface of the earth at SNOLAB. Though shielded from surface backgrounds, emanation of radon radioisotopes from the surrounding rock leads to back-grounds. The characteristic decay of radon and its daughters allows for an alpha detection technique to count the amount of Rn-222 atoms collected. Traps can collect Rn-222 from various positions and materials, including an assay skid that will collect Rn-222 from the organic liquid scintillator used to detect interactions within SNO+.

  9. Portable gamma-ray holdup and attributes measurements of high- and variable-burnup plutonium

    International Nuclear Information System (INIS)

    Wenz, T.R.; Russo, P.A.; Miller, M.C.; Menlove, H.O.; Takahashi, S.; Yamamoto, Y.; Aoki, I.

    1991-01-01

    High burnup-plutonium holdup has been assayed quantitatively by low resolution gamma-ray spectrometry. The assay was calibrated with four plutonium standards representing a range of fuel burnup and 241 Am content. Selection of a calibration standard based on its qualitative spectral similarity to gamma-ray spectra of the process material is partially responsible for the success of these holdup measurements. The spectral analysis method is based on the determination of net counts in a single spectral region of interest (ROI). However, the low-resolution gamma-ray assay signal for the high-burnup plutonium includes unknown amounts of contamination from 241 Am. For most needs, the range of calibration standards required for this selection procedure is not available. A new low-resolution gamma-ray spectral analysis procedure for assay of 239 Pu has been developed. The procedure uses the calculated isotope activity ratios and the measured net counts in three spectral ROIs to evaluate and remove the 241 Am contamination from the 239 Pu assay signal on a spectrum-by-spectrum basis. The calibration for the new procedure requires only a single plutonium standard. The procedure also provides a measure of the burnup and age attributes of holdup deposits. The new procedure has been demonstrated using portable gamma-ray spectroscopy equipment for a wide range of plutonium standards and has also been applied to the assay of 239 Pu holdup in a mixed oxide fuel fabrication facility. 10 refs., 5 figs., 3 tabs

  10. RAS - Screens & Assays - Drug Discovery

    Science.gov (United States)

    The RAS Drug Discovery group aims to develop assays that will reveal aspects of RAS biology upon which cancer cells depend. Successful assay formats are made available for high-throughput screening programs to yield potentially effective drug compounds.

  11. Improving shuffler assay accuracy

    International Nuclear Information System (INIS)

    Rinard, P.M.

    1995-01-01

    Drums of uranium waste should be disposed of in an economical and environmentally sound manner. The most accurate possible assays of the uranium masses in the drums are required for proper disposal. The accuracies of assays from a shuffler are affected by the type of matrix material in the drums. Non-hydrogenous matrices have little effect on neutron transport and accuracies are very good. If self-shielding is known to be a minor problem, good accuracies are also obtained with hydrogenous matrices when a polyethylene sleeve is placed around the drums. But for those cases where self-shielding may be a problem, matrices are hydrogenous, and uranium distributions are non-uniform throughout the drums, the accuracies are degraded. They can be greatly improved by determining the distributions of the uranium and then applying correction factors based on the distributions. This paper describes a technique for determining uranium distributions by using the neutron count rates in detector banks around the waste drum and solving a set of overdetermined linear equations. Other approaches were studied to determine the distributions and are described briefly. Implementation of this correction is anticipated on an existing shuffler next year

  12. Competitive protein binding assay

    International Nuclear Information System (INIS)

    Kaneko, Toshio; Oka, Hiroshi

    1975-01-01

    The measurement of cyclic GMP (cGMP) by competitive protein binding assay was described and discussed. The principle of binding assay was represented briefly. Procedures of our method by binding protein consisted of preparation of cGMP binding protein, selection of 3 H-cyclic GMP on market, and measurement procedures. In our method, binding protein was isolated from the chrysalis of silk worm. This method was discussed from the points of incubation medium, specificity of binding protein, the separation of bound cGMP from free cGMP, and treatment of tissue from which cGMP was extracted. cGMP existing in the tissue was only one tenth or one scores of cGMP, and in addition, cGMP competed with cGMP in binding with binding protein. Therefore, Murad's technique was applied to the isolation of cGMP. This method provided the measurement with sufficient accuracy; the contamination by cAMP was within several per cent. (Kanao, N.)

  13. The Future of Gamma Ray Astrophysics

    CERN Multimedia

    CERN. Geneva

    2016-01-01

    Over the past decade, gamma ray astrophysics has entered the astrophysical mainstream. Extremely successful space-borne (GeV) and ground-based (TeV) detectors, combined with a multitude of partner telescopes, have revealed a fascinating “astroscape" of active galactic nuclei, pulsars, gamma ray bursts, supernova remnants, binary stars, star-forming galaxies, novae much more, exhibiting major pathways along which large energy releases can flow. From  a basic physics perspective, exquisitely sensitive measurements have constrained the nature of dark matter, the cosmological origin of magnetic field and the properties of black holes. These advances have motivated the development of new facilities, including HAWC, DAMPE, CTA and SVOM, which will further our understanding of the high energy universe. Topics that will receive special attention include merging neutron star binaries, clusters of galaxies, galactic cosmic rays and putative, TeV dark matter.

  14. Gamma emitters in Hong Kong water

    International Nuclear Information System (INIS)

    Shun-Yin, L.; Chung-Keung, M.; Wai-Kwok, N.; Shiu-Chun, A.

    1990-01-01

    Radioactivity in water originates from natural and artificial sources. The development of a nuclear powerplant near Hong Kong necessitates that attention be given to formulating techniques to assess the possible resultant environmental radioactive contamination. Water samples collected from various sites in Hong Kong in the spring and summer of 1987, representing seawater, river water, reservoir water, drinking water, and underground water were studied through gamma-ray spectral analysis. Only gamma emitters in the U238 and Th232 series and K40 were detected. No fission product was detected with specific activity above 0.1 Bq/kg. The data could be the baseline for future monitoring of the radioactivity released from a nuclear plant being built at a 50-km distance from Hong Kong. The variation of detected specific activities may be due to geological differences and the effect of plants. 1 ref., 3 tabs

  15. In vitro assays for predicting tumor cell response to radiation by apoptotic pathways

    International Nuclear Information System (INIS)

    Algan, Oe.; Hanks, G.E.; Biade, S.; Chapman, J.D.

    1995-01-01

    Purpose: We had previously shown that the rate of spontaneous and radiation-induced apoptosis was significantly greater in well-differentiated compared to anaplastic Dunning prostate carcinomas. The goal of this study was to define the most useful assay for quantifying radiation-induced apoptotic cell death and to determine if measured rates of radiation-induced apoptosis in tumor cell populations can predict treatment outcome. Materials and Methods: The time course and extent of radiation-induced apoptosis after single doses of Cesium-137 gamma-rays were measured by five different assays. These included gross DNA degradation, nucleosome ladder formation, labeling of 3'-OH ends in DNA with an immunofluorescence probe, immunofluorescence vital stains (LIVE/DEAD[reg] EUKOLIGHT TM ) and trypan blue. The majority of these studies were performed with DU-145 human prostate cells. Data was analyzed to determine the component of cell inactivation resulting from apoptosis with the modified linear quadratic equation, -1n (SF) = (α a + α p ) D + β p D 2 , were α a represents cell inactivation by radiation-induced apoptosis, α p and β p represent cell death by proliferative mechanisms and D represents radiation dose. Results: These studies indicated that DU-145 cell death after radiation occurs over two distinct time periods. The first phase of death begins shortly after irradiation and plateaus within 16-24 hr. This process of cell death has properties consistent with apoptosis as determined by 3'-OH DNA end-labeling and nucleosome ladder assays. The second phase of cell death (determined by viability staining) begins approximately 48 hr after irradiation and continues until the remainder of inactivated cells express their death. This longer phase of cell inactivation probably represents proliferative cell death and other non-apoptotic mechanisms. The five different assays were performed on DU-145 cells 24 hr after irradiation with 10 Gy. Significant nucleosome ladders

  16. Radioreceptor assay analysis of tamsulosin and terazosin pharmacokinetics

    NARCIS (Netherlands)

    Taguchi, K.; Schäfers, R. F.; Michel, M. C.

    1998-01-01

    AIMS: A radioreceptor assay has been developed for alpha1-adrenoceptor subtypes and applied to a pharmacokinetic analysis of tamsulosin and terazosin. METHODS: Young, male, healthy volunteers received 0.4 mg tamsulosin (as Omnic modified release capsules) or 5 mg terazosin (as Flotrin tablets) in a

  17. Integration of TGS and CTEN assays using the CTENFIT analysis and databasing program

    International Nuclear Information System (INIS)

    Estep, R.

    2000-01-01

    The CTEN F IT program, written for Windows 9x/NT in C++, performs databasing and analysis of combined thermal/epithermal neutron (CTEN) passive and active neutron assay data and integrates that with isotopics results and gamma-ray data from methods such as tomographic gamma scanning (TGS). The binary database is reflected in a companion Excel database that allows extensive customization via Visual Basic for Applications macros. Automated analysis options make the analysis of the data transparent to the assay system operator. Various record browsers and information displays simplified record keeping tasks

  18. Toxics Release Inventory (TRI)

    Data.gov (United States)

    U.S. Environmental Protection Agency — The Toxics Release Inventory (TRI) is a dataset compiled by the U.S. Environmental Protection Agency (EPA). It contains information on the release and waste...

  19. Co-incubation with IL-18 potentiates antigen-specific IFN-γ response in a whole-blood stimulation assay for measurement of cell-mediated immune responses in pigs experimentally infected with Lawsonia intracellularis

    DEFF Research Database (Denmark)

    Riber, Ulla; Boesen, Henriette Toft; Jakobsen, Jeanne Toft

    2011-01-01

    The whole-blood interferon-gamma (IFN-γ) assay is a quantitative in-vitro assay for a direct read out of Ag-specific cell-mediated immune (CMI) responses to infectious diseases. The IFN-γ assay is robust in severe intracellular infections like Brucella or mycobacteria, but more difficult to evalu......The whole-blood interferon-gamma (IFN-γ) assay is a quantitative in-vitro assay for a direct read out of Ag-specific cell-mediated immune (CMI) responses to infectious diseases. The IFN-γ assay is robust in severe intracellular infections like Brucella or mycobacteria, but more difficult...

  20. Fluorescence imaging of glutamate release in neurons

    International Nuclear Information System (INIS)

    Wang, Ziqiang; Yeung, Edward S.

    1999-01-01

    A noninvasive detection scheme based on glutamate dehydrogenase (GDH) enzymatic assay combined with microscopy was developed to measure the glutamate release in cultured cells from the central nervous system (CNS). The enzyme reaction is very specific and sensitive. The detection limit with charge-coupled device (CCD) imaging is down to μM levels of glutamate with reasonable response time (∼30 s). The standard glutamate test shows a linear response over 3 orders of magnitude, from μM to 0.1 mM range. The in vitro monitoring of glutamate release from cultured neuron cells demonstrated excellent spatial and temporal resolution. (c) 1999 Society for Applied Spectroscopy

  1. An acoustic prion assay

    Directory of Open Access Journals (Sweden)

    Gordon Hayward

    2016-12-01

    Full Text Available An acoustic prion assay has been demonstrated for sheep brain samples. Only five false positives and no false negatives were observed in a test of 45 positive and 45 negative samples. The acoustic prion sensor was constructed using a thickness shear mode quartz resonator coated with a covalently bound recombinant prion protein. The characteristic indicator of a scrapie infected sheep brain sample was an observed shoulder in the frequency decrease in response to a sample.The response of the sensor aligns with a conformational shift in the surface protein and with the propagation mechanism of the disease. This alignment is evident in the response timing and shape, dependence on concentration, cross species behaviour and impact of blood plasma. This alignment is far from sufficient to prove the mechanism of the sensor but it does offer the possibility of a rapid and inexpensive additional tool to explore prion disease. Keywords: Prions, Thickness shear mode quartz sensor

  2. Assay of oestrogen

    International Nuclear Information System (INIS)

    Edwards, J.C.

    1981-01-01

    A particular problem with the direct radioimmunoassay of unconjugated oestriol in pregnancy is caused by the increased amount of steroid-binding proteins present in pregnancy serum and plasma. The steroid-binding proteins react with oestriol and 125 I-labelled oestriol during the assay procedure and the steroid-protein bound 125 I-labelled oestriol is precipitated along with the antibody-bound 125 I-labelled oestriol by the ammonium sulphate solution separation system. A novel method is described whereby progesterone (1-20 μg/ml) is used to block the action of steroid-binding proteins in pregnancy serum and plasma samples, thus minimizing interference in a direct radioimmunoassay for unconjugated oestriol using a specific anti-oestriol serum. (U.K.)

  3. Nondestructive fission gas release measurement and analysis

    International Nuclear Information System (INIS)

    O'Leary, P.M.; Packard, D.R.

    1993-01-01

    Siemens Power Corporation (SPC) has performed reactor poolside gamma scanning measurements of fuel rods for fission gas release (FGR) detection for more than 10 yr. The measurement system has been previously described. Over the years, the data acquisition system, the method of spectrum analysis, and the means of reducing spectrum interference have been significantly improved. A personal computer (PC)-based multichannel analyzer (MCA) package is used to collect, display, and store high-resolution gamma-ray spectra measured in the fuel rod plenum. A PC spread sheet is used to fit the measured spectra and compute sample count rates after Compton background subtraction. A Zircaloy plenum spacer is often used to reduce positron annihilation interference that can arise from the INCONEL reg-sign plenum spring used in SPC-manufactured fuel rods

  4. Rapid screening assay for calcium bioavailability studies

    International Nuclear Information System (INIS)

    Luhrsen, K.R.; Hudepohl, G.R.; Smith, K.T.

    1986-01-01

    Calcium bioavailability has been studied by numerous techniques. The authors report here the use of the gamma emitting isotope of calcium ( 47 Ca) in a whole body retention assay system. In this system, calcium sources are administered by oral gavage and subsequent counts are determined and corrected for isotopic decay. Unlike iron and zinc retention curves, which exhibit a 2-3 day equilibration period, calcium reaches equilibration after 24 hours. Autoradiographic analysis of the femurs indicate that the newly absorbed calcium is rapidly distributed to the skeletal system. Moreover, the isotope is distributed along the entire bone. Comparisons of calcium bioavailability were made using intrinsic/extrinsic labeled milk from two species i.e. rat and goat as well as CaCO 3 . In addition, extrinsic labeled cow milk was examined. In the rat, the extrinsic labeled calcium from milk was better absorbed than the intrinsic calcium. This was not the case in goat milk or the calcium carbonate which exhibited no significant differences. Chromatographic analysis of the labeled milk indicates a difference in distribution of the 47 Ca. From these data, the authors recommend the use of this assay system in calcium bioavailability studies. The labeling studies and comparisons indicate caution should be used, however, in labeling techniques and species milk comparison

  5. Measurement of gamma radioactivity in steel

    International Nuclear Information System (INIS)

    Wachtendonk, H.J. von; Flock, J.; Grientschnig, D.; Kircher, T.; Kroos, J.; Mertens, S.; Mueller, J.; Puchmayr, J.; Schlothmann, B.J.; Schmitz, H.U.; Troebs, V.; Unger, H.

    1999-01-01

    The steel industry is being confronted increasingly with radioactive scrap from dismantled nuclear facilities. The clearance and release regulations that exist around the world differ very greatly and are difficult to implement. A 'radioactivity measurement' working group has therefore been set up at VDEh to clarify how radioactive measurements can be integrated into the day-to-day production routine. Operating results obtained at Thyssen Krupp Stahl AG with a gamma-ray spectrometer indicate a possibility for the simple detection of radioactive contamination. (orig.) [de

  6. An improved segmented gamma scanning for radioactive waste drums

    International Nuclear Information System (INIS)

    Liu Cheng; Wang Dezhong; Bai Yunfei; Qian Nan

    2010-01-01

    In this paper, the equivalent radius of radioactive sources in each segment is determined by analyzing the different responses of the two identical detectors, and an improved segmented gamma scanning is used to assay waste drums containing mainly organic materials, and proved by an established simulation model. The simulated radioactivity distributions in homogenous waste drum and an experimental heterogeneous waste drum were compared with those of traditional segmented gamma scanning. The results show that our method is good in performance and can be used for analyzing the waste drums. (authors)

  7. System for gamma-gamma formation density logging while drilling

    International Nuclear Information System (INIS)

    Paske, W.C.

    1991-01-01

    The patent relates to a system for logging subterranean formations for the determination of formation density by using gamma radiation. Gamma ray source and detection means are disposed within a housing adapted for positioning within a borehole for the emission and detection of gamma rays propagating through earth formations and borehole drilling fluid. The gamma ray detection means comprises first and second gamma radiation sensors geometrically disposed within the housing, the same longitudinal distance from the gamma ray source and diametrically opposed in a common plane. A formation matrix density output signal is produced in proportion to the output signal from each of the gamma ray sensors and in conjunction with certain constants established by the geometrical configuration of the sensors relative to the gamma ray source and the borehole diameter. Formation density is determined without regard to the radial position of the logging probe within the borehole in a measuring while drilling mode. 6 figs

  8. Reference materials for nondestructive assay of special nuclear material. Volume 1. Uranium oxide plus graphite powder

    International Nuclear Information System (INIS)

    Sprinkle, J.K.; Likes, R.N.; Parker, J.L.; Smith, H.A.

    1983-10-01

    This manual describes the fabrication of reference materials for use in gamma-ray-based nondestructive assay of low-density uranium-bearing samples. The sample containers are 2-l bottles. The reference materials consist of small amounts of UO 2 spread throughout a graphite matrix. The 235 U content ranges from 0 to 100 g. The manual also describes the far-field assay procedure used with low-resolution detectors

  9. Modular gamma systems

    International Nuclear Information System (INIS)

    Millegan, D.R.; Nixon, K.V.

    1982-01-01

    Nuclear safeguards requires sensitive, easily operated instruments for rapid inspection of personnel and vehicles to ensure that no uranium or plutonium is being diverted. Two portable gamma-ray detection systems have been developed. The Modular Gamma System (MGS) is very sensitive and two or more systems can be connected for even better performance. The multiunit configuration can be deployed by motor vehicle for search of large areas too extensive to search on foot. The Programmable Rate Monitor (PRM) is less sensitive but much smaller and therefore is more suitable for search of vehicles, personnel, or smaller areas. The PRM is programmable, which implements measurement and alarm algorithms for individual applications

  10. Proprioceptive evoked gamma oscillations

    DEFF Research Database (Denmark)

    Arnfred, S.M.; Hansen, Lars Kai; Parnas, J.

    2007-01-01

    A proprioceptive stimulus consisting of a weight change of a handheld load has recently been shown to elicit an evoked potential. Previously, somatosensory gamma oscillations have only been evoked by electrical stimuli. We conjectured that a natural proprioceptive stimulus also would be able...... to evoke gamma oscillations. EEG was recorded using 64 channels in 14 healthy subjects. In each of three runs a stimulus of 100 g load increment in each hand was presented in 120 trials. Data were wavelet transformed and runs collapsed. Inter-trial phase coherence (ITPC) was computed as the best measure...

  11. Gamma-Ray Bursts

    Science.gov (United States)

    Pellizza, L. J.

    Gamma-ray bursts are the brightest transient sources in the gamma-ray sky. Since their discovery in the late 1960s, the investigation of the astrophysical sys- tems in which these phenomena take place, and the physical mechanisms that drive them, has become a vast and prolific area of modern astrophysics. In this work I will briefly describe the most relevant observations of these sources, and the models that describe their nature, emphasizing on the in- vestigations about the progenitor astrophysical systems. FULL TEXT IN SPANISH

  12. Gamma Ray Bursts

    Science.gov (United States)

    Gehrels, Neil; Meszaros, Peter

    2012-01-01

    Gamma-ray bursts (GRBs) are bright flashes of gamma-rays coming from the cosmos. They occur roughly once per day ,last typically lOs of seconds and are the most luminous events in the universe. More than three decades after their discovery, and after pioneering advances from space and ground experiments, they still remain mysterious. The launch of the Swift and Fermi satellites in 2004 and 2008 brought in a trove of qualitatively new data. In this review we survey the interplay between these recent observations and the theoretical models of the prompt GRB emission and the subsequent afterglows.

  13. Comparison of Tuberculin Skin Test result and interferon gamma response to human PPD in BCG scar positive and negative children.

    Science.gov (United States)

    Sayyahfar, Shirin; Karimi, Abdollah; Fahimzad, Alireza; Shamshiri, Ahmad Reza

    2014-03-01

    The aim of this study is to compare Tuberculin Skin Test (TST) result and interferon gamma response to human PPD (purified protein derivative), in scar positive and scar negative BCG-vaccinated children. Between August 2007 and May 2008 a total of 236 children aged 1-168 months (mean 21 months) admitted to Mofid Children's Hospital, Tehran, Iran, were enrolled in a cross-sectional study. Each patient was examined for BCG vaccine scar and tested with TST and human PPD-based Interferon Gamma Release Assay (IGRA). Two hundred and twenty one cases out of 236 (44% female, 1-168 months, mean age 21 months) were scar positive of whom 95% TST result was negative. Human PPD-based IGRA was positive in 110 (49.8%), negative in 85 (38.4 %) and indeterminate in 26 (11.8%) of scar positive patients. Fifteen children (40% female, 1-156 months; mean age 42 months) were scar negative. All the scar negative cases were TST negative. Human PPD-based IGRA was positive in 10 (66.7%), negative in 4 (26.7%) and indeterminate in 1 (6.7%) of scar negative patients. Immune responsiveness to human PPD antigens in scar positive and negative children may not correspond with results of the Tuberculin Skin Test. Copyright © 2013 Ministry of Health, Saudi Arabia. Published by Elsevier Ltd. All rights reserved.

  14. Incorporation and distribution of dihomo-gamma-linolenic acid, arachidonic acid, and eicosapentaenoic acid in cultured human keratinocytes

    International Nuclear Information System (INIS)

    Punnonen, K.; Puustinen, T.; Jansen, C.T.

    1986-01-01

    Human keratinocytes in culture were labelled with 14 C-dihomo-gamma-linolenic acid, 14 C-arachidonic acid or 14 C-eicosapentaenoic acid. All three eicosanoid precursor fatty acids were effectively incorporated into the cells. In phospholipids most of the radioactivity was recovered, in neutral lipids a substantial amount, and as free unesterified fatty acids only a minor amount. Most of the radioactivity was found in phosphatidylethanolamine which was also the major phospholipid as measured by phosphorous assay. The incorporation of dihomo-gamma-linolenic acid and arachidonic acid into lipid subfractions was essentially similar. Eicosapentaenoic acid was, however, much less effectively incorporated into phosphatidylinositol + phosphatidylserine and, correspondingly, more effectively into triacylglycerols as compared to the two other precursor fatty acids. Once incorporated, the distribution of all three precursor fatty acids was relatively stable, and only minor amounts of fatty acids were released into the culture medium during short term culture (two days). Our study demonstrates that eicosanoid precursor fatty acids are avidly taken up by human keratinocytes and esterified into membrane lipids. The clinical implication of this finding is that dietary manipulations might be employed to cause changes in the fatty acid composition of keratinocytes

  15. Interferon Gamma-1b Injection

    Science.gov (United States)

    Interferon gamma-1b injection is used to reduce the frequency and severity of serious infections in people with chronic ... severe, malignant osteopetrosis (an inherited bone disease). Interferon gamma-1b is in a class of medications called ...

  16. Gamma knife surgery for craniopharyngioma

    International Nuclear Information System (INIS)

    Prasad, D.; Steiner, M.; Steiner, L.

    1995-01-01

    We present our results of Gamma Knife surgery for craniopharyngioma in nine patients. The current status of surgery, radiation therapy, intracavitary instillation of radionuclides and Gamma Knife surgery in the management of craniopharyngiomas is discussed. (author)

  17. CKM angle $\\gamma$ from LHCb

    CERN Multimedia

    Smith, Jackson

    2015-01-01

    Results of the latest $\\gamma$ combination from LHCb are presented, along with the six LHCb measurements used as inputs. In addition, the anticipated precision attainable for measuring $\\gamma$ after the LHCb Upgrade is outlined

  18. Calculation method for gamma-dose rates from spherical puffs

    International Nuclear Information System (INIS)

    Thykier-Nielsen, S.; Deme, S.; Lang, E.

    1993-05-01

    The Lagrangian puff-models are widely used for calculation of the dispersion of atmospheric releases. Basic output from such models are concentrations of material in the air and on the ground. The most simple method for calculation of the gamma dose from the concentration of airborne activity is based on semi-infinite cloud model. This method is however only applicable for points far away from the release point. The exact calculation of the cloud dose using the volume integral requires significant computer time. The volume integral for the gamma dose could be approximated by using the semi-infinite cloud model combined with correction factors. This type of calculation procedure is very fast, but usually the accuracy is poor due to the fact that the same correction factors are used for all isotopes. The authors describe a more elaborate correction method. This method uses precalculated values of the gamma-dose rate as a function of the puff dispersion parameter (δ p ) and the distance from the puff centre for four energy groups. The release of energy for each radionuclide in each energy group has been calculated and tabulated. Based on these tables and a suitable interpolation procedure the calculation of gamma doses takes very short time and is almost independent of the number of radionuclides. (au) (7 tabs., 7 ills., 12 refs.)

  19. Calculation method for gamma dose rates from Gaussian puffs

    Energy Technology Data Exchange (ETDEWEB)

    Thykier-Nielsen, S; Deme, S; Lang, E

    1995-06-01

    The Lagrangian puff models are widely used for calculation of the dispersion of releases to the atmosphere. Basic output from such models is concentration of material in the air and on the ground. The most simple method for calculation of the gamma dose from the concentration of airborne activity is based on the semi-infinite cloud model. This method is however only applicable for puffs with large dispersion parameters, i.e. for receptors far away from the release point. The exact calculation of the cloud dose using volume integral requires large computer time usually exceeding what is available for real time calculations. The volume integral for gamma doses could be approximated by using the semi-infinite cloud model combined with correction factors. This type of calculation procedure is very fast, but usually the accuracy is poor because only a few of the relevant parameters are considered. A multi-parameter method for calculation of gamma doses is described here. This method uses precalculated values of the gamma dose rates as a function of E{sub {gamma}}, {sigma}{sub y}, the asymmetry factor - {sigma}{sub y}/{sigma}{sub z}, the height of puff center - H and the distance from puff center R{sub xy}. To accelerate the calculations the release energy, for each significant radionuclide in each energy group, has been calculated and tabulated. Based on the precalculated values and suitable interpolation procedure the calculation of gamma doses needs only short computing time and it is almost independent of the number of radionuclides considered. (au) 2 tabs., 15 ills., 12 refs.

  20. An epidermal equivalent assay for identification and ranking potency of contact sensitizers

    NARCIS (Netherlands)

    Gibbs, S.; Corsini, E.; Spiekstra, S.W.; Galbiati, V.; Fuchs, H.W.; Degeorge, G.; Troese, M.; Hayden, P.; Deng, W.; Roggen, E.

    2013-01-01

    The purpose of this study was to explore the possibility of combining the epidermal equivalent (EE) potency assay with the assay which assesses release of interleukin-18 (IL-18) to provide a single test for identification and classification of skin sensitizing chemicals, including chemicals of low

  1. Ultrasonography X gamma radiography

    International Nuclear Information System (INIS)

    Mello Campos, A.M. de

    1989-01-01

    The accumulated experience in the last ten years of substitution to essays by gamma radiography to essay by ultrasonography, starting of the systematic comparison and tabulation of the results obtained by both essays applied in welding joints, in field, in steel pipelines of the SABESP. (V.R.B.)

  2. Gamma knife radiosurgery

    International Nuclear Information System (INIS)

    Kobayashi, Tatsuya; Mori, Yohsimasa; Kida, Yoshihisa

    2003-01-01

    Gamma knife radiosurgery has become a new treatment modality in the field of neurosurgery since the first gamma knife was brought into Japan in 1990. Advances in applications of new indications and long-term results have been continued to evolve during the past 12 years. Based on the experience of more than 4,500 cases treated by gamma knife at Komaki City Hospital, long-term results of arteriovenous malformations (AVMs), metastatic brain tumors, acoustic neurinomas, meningiomas and trigeminal neuralgias are presented. Radiosurgery has become a novel treatment modality, especially for AVM, acoustic neurinoma and meningioma, which were once only treatable by conventional surgery, and shows a high cure rate in AVM cases and high control rate in benign tumors without major complications. The effects of radiosurgery for metastatic brain tumors have been thought to be superior to fractionated radiotherapy due to high response and control rates, and patients showed improved quality of life although no prolongation of the life span was obtained. Gamma knife treatment for trigeminal neuralgia has been shown to be effective and less invasive than microvascular decompression, and is useful for cases resistant to conventional therapies and as an initial treatment as well. (author)

  3. Automated gamma counters

    International Nuclear Information System (INIS)

    Regener, M.

    1977-01-01

    This is a report on the most recent developments in the full automation of gamma counting in RIA, in particular by Messrs. Kontron. The development targets were flexibility in sample capacity and shape of test tubes, the possibility of using different radioisotopes for labelling due to an optimisation of the detector system and the use of microprocessers to substitute software for hardware. (ORU) [de

  4. Gamma cardio 82

    International Nuclear Information System (INIS)

    Itti, R.

    1982-01-01

    New trends in nuclear cardiology are briefly presented supported by a large bibliography. The following topics are reviewed: new tracers of myocardial perfusion and metabolism; quantitative analysis of cardiac function; nuclear stethoscope; gamma emission tomography; diagnostic value of cardiac dynamic tests (at rest and during exercise), pharmacological tests; new clinical applications of cardiovascular nuclear medicine [fr

  5. Marine gamma spectrometric survey

    International Nuclear Information System (INIS)

    Kostoglodov, V.V.

    1979-01-01

    Presented are theoretical problems physical and geochemical prerequisites and possibilities of practical application of the method of continuous submarine gamma-spectrometric survey and radiometric survey destined for rapid study of the surface layer of marine sediments. Shown is high efficiency and advantages of this method in comparison with traditional and widely spread in marine geology methods of bottom sediments investigation

  6. Industrial radiography. Gamma radiography

    International Nuclear Information System (INIS)

    Menetrier, J.

    1975-01-01

    Informations are given on gamma radiodefectology regulations, entire references and main dispositions applicable to each state of the European Economic Community. The content includes previous arrangements for source acquisition, holding and use of the sources, transport, accidents, civil liability of the source holder, person insurance against radiation hazards and contamination, property insurance, penal liability of the source holder

  7. Introscopy using gamma sources

    International Nuclear Information System (INIS)

    Gromov, Yu.V.; Leonov, B.I.; Najorov, A.N.; Smirnov, N.N.; Firstov, V.G.

    1978-01-01

    A method is described of working with standard 170 Tm, 75 Se, 192 Ir, 137 Cs and 60 Co sources at the activity of 1-4000 Ci, during television gamma introscopy of steel products. Experiments involving the RI-10T introscope are carried out to determine prospects of using various radiation sources. The results of using X-ray instruments for control of steel products are also shown for comparison. In introscopy of X-rayed steel products over 25 mm thick, spreading of the edge of the detected groove image is shown to be comparable when using X radiation and gamma radiation of standard sources. Sensitivity of control by fluorographic introscope in X-raying and gamma irradiation of products over 25 mm thick will presumably be the same owing to the detector storage capacity. The use of commercial gamma flaw detecting instruments together with a television introscope permits to reliably reveal defects of 0.5-2.0 mm in size, eliminating possible instability of operation of X-ray instruments, particularly in field conditions

  8. Gamma apparatuses for radiotherapy

    International Nuclear Information System (INIS)

    Sul'kin, A.G.

    1986-01-01

    Scientific and technical achievements in development and application of gamma therapeutic apparatuses for external and intracavity irradiations are generalized. Radiation-physical parameters of apparatuses providing usability of progressive methods in radiotherapy of onclogical patients are given. Optimization of main apparatus elements, ensurance of its operation reliability, reduction of errors of irradiation plan reproduction are considered. Attention is paid to radiation safety

  9. Gamma ray calibration system

    International Nuclear Information System (INIS)

    Rosauer, P.J.; Flaherty, J.J.

    1981-01-01

    This invention is in the field of gamma ray inspection devices for tubular products and the like employing an improved calibrating block which prevents the sensing system from being overloaded when no tubular product is present, and also provides the operator with a means for visually detecting the presence of wall thicknesses which are less than a required minimum. (author)

  10. Q{sub {gamma}-H2AX}, an analysis method for partial-body radiation exposure using {gamma}-H2AX in non-human primate lymphocytes

    Energy Technology Data Exchange (ETDEWEB)

    Redon, Christophe E., E-mail: redonc@mail.nih.gov [NIH, NCI, CCR, Laboratory of Molecular Pharmacology, Bethesda, MD 20892 (United States); Nakamura, Asako J.; Gouliaeva, Ksenia [NIH, NCI, CCR, Laboratory of Molecular Pharmacology, Bethesda, MD 20892 (United States); Rahman, Arifur; Blakely, William F. [Armed Forces Radiobiology Research Institute, Uniformed Services University, Bethesda, MD 20889-5603 (United States); Bonner, William M. [NIH, NCI, CCR, Laboratory of Molecular Pharmacology, Bethesda, MD 20892 (United States)

    2011-09-15

    We previously used the {gamma}-H2AX assay as a biodosimeter for total-body irradiation (TBI) exposure ({gamma}-rays) in a rhesus macaque (Macaca mulatta) model. Utilizing peripheral blood lymphocytes and plucked hairs, we obtained statistically significant {gamma}-H2AX responses days after total-body exposure to 1-8.5 Gy ({sup 60}Co {gamma}-rays at 55 cGy min{sup -1}). Here, we introduce a partial-body exposure analysis method, Q{sub {gamma}-H2AX}, which is based on the number of {gamma}-H2AX foci per damaged cells as evident by having one or more {gamma}-H2AX foci per cell. Results from the rhesus monkey - TBI study were used to establish Q{sub {gamma}-H2AX} dose-response calibration curves to assess acute partial-body exposures. {gamma}-H2AX foci were detected in plucked hairs for several days after in vivo irradiation demonstrating this assay's utility for dose assessment in various body regions. The quantitation of {gamma}-H2AX may provide a robust biodosimeter for analyzing partial-body exposures to ionizing radiation in humans.

  11. Technical Safety Requirements for the Gamma Irradiation Facility (GIF)

    CERN Document Server

    Mahn, J A E M J G

    2003-01-01

    This document provides the Technical Safety Requirements (TSR) for the Sandia National Laboratories Gamma Irradiation Facility (GIF). The TSR is a compilation of requirements that define the conditions, the safe boundaries, and the administrative controls necessary to ensure the safe operation of a nuclear facility and to reduce the potential risk to the public and facility workers from uncontrolled releases of radioactive or other hazardous materials. These requirements constitute an agreement between DOE and Sandia National Laboratories management regarding the safe operation of the Gamma Irradiation Facility.

  12. Glucose metabolism in gamma-irradiated rice seeds

    International Nuclear Information System (INIS)

    Inoue, M.; Hasegawa, H.; Hori, S.

    1980-01-01

    Gamma-irradiation of 30 kR in rice seeds caused marked inhibition in seedling growth, and prevented the release of reduced sugar during the period of 25 to 76hr after soaking. The C 6 /C 1 ratio following irradiation continued to decrease up to the 76th hour of soaking; the control's ratio tended to increase with comparable soaking time. The percentage recovery of 14 C in carbon dioxide from glucose -1- 14 C was lower in irradiated than in control seeds. These results indicate that gamma-irradiation reduces the participation of the pentose phosphate pathway in glucose catabolism during an early period of germination. (author)

  13. Proceedings for the nondestructive assay and nondestructive examination waste characterization conference. No. 5

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1997-05-01

    This report contains paper presented at the 5th Nondestructive Assay and nondestructive Examination Waste Characterization conference. Topics included compliance, neutron NDA techniques, gamma NDA techniques, tomographic methods, and NDA modality and information combination techniques. Individual reports have been processed separately for the United States Department of Energy databases.

  14. Proceedings for the nondestructive assay and nondestructive examination waste characterization conference. No. 5

    International Nuclear Information System (INIS)

    1997-01-01

    This report contains paper presented at the 5th Nondestructive Assay and nondestructive Examination Waste Characterization conference. Topics included compliance, neutron NDA techniques, gamma NDA techniques, tomographic methods, and NDA modality and information combination techniques. Individual reports have been processed separately for the United States Department of Energy databases

  15. Equine interferon gamma synthesis in lymphocytes after in vivo infection and in vitro stimulation with EHV-1.

    Science.gov (United States)

    Paillot, R; Daly, J M; Juillard, V; Minke, J M; Hannant, D; Kydd, J H

    2005-08-22

    Equine cytotoxic T lymphocyte (CTL) responses to equine herpesvirus-1 (EHV-1) are well characterised but little is known about the cytokine response after infection or vaccination. EHV-1 is common in horses and infects lymphocytes in vivo. This virus was used as a model to measure the synthesis of interferon gamma (IFN-gamma) by equine peripheral blood mononuclear cells (PBMC) after in vivo infection and/or in vitro stimulation with EHV-1. Both flow cytometry and ELISPOT assays were used to quantify equine IFN-gamma using a mouse anti-bovine IFN-gamma monoclonal antibody (clone CC302; shown to cross-react with recombinant equine IFN-gamma) and a rabbit anti-canine IFN-gamma polyclonal antibody. The percentage of PBMC synthesising IFN-gamma after in vitro stimulation with EHV-1 increased with age. In yearlings infected experimentally with EHV-1, PBMC showed two peaks of IFN-gamma synthesis, 11 and 56 days after infection. The IFN-gamma synthesis was principally associated with CD8(+) cells. The patterns of IFN-gamma synthesis detected by intracellular IFN-gamma staining or ELISPOT were compared with CTL data and shown to be similar. These methods were also applied successfully to frozen samples of PBMC. Measurement of equine IFN-gamma using these simple techniques can now be applied to future studies on protective cellular immune responses following virus infection and/or vaccination of horses.

  16. Cosmical sources of gamma radiation

    Energy Technology Data Exchange (ETDEWEB)

    Kuchowicz, B [Warsaw Univ. (Poland)

    1974-01-01

    A brief historical outline of the X-ray and ..gamma..-ray astronomies is given first, then a summary of the recent status of X-ray astronomy follows. Further chapters include information on ..gamma..-ray sources in the solar system, in our Galaxy, and beyond it. In discussing linear gamma spectra attention is paid to the possibility of studying explosive nucleo-synthesis by observation of gamma lines from supernova remnants, etc. Questions of the isotropic gamma background are discussed at the end of the survey.

  17. Effect of gamma irradiation on antioxidant activity of Amoora rohitaka

    International Nuclear Information System (INIS)

    Rajurkar, N.S.; Gaikwad, K.N.

    2012-01-01

    The effect of a medium dose of gamma radiation on antioxidant activity of Amoora rohitaka was studied. Radiation doses were 0, 1, 3 and 5 kGy. Antioxidant activity was screened by using different assay. With increasing dose the formation of Maillard reaction products (MRPs) contributes to the increase in the antioxidant activity. MRPs are formed as a result of Maillard reaction. In ABTS [2,2-azino-bis-3-ethylbenzothiazoline-6-sulfonic acid di-ammonium salt] assay, ethanol extract showed increase in scavenging activity. It also showed a marked increase in polyphenolic contents. The present study reveals that gamma irradiation can be an efficient process to increase antioxidant activity of Amoora rohitaka. (author)

  18. In vitro cell culture lethal dose submitted to gamma radiation

    Energy Technology Data Exchange (ETDEWEB)

    Moreno, Carolina S.; Rogero, Sizue O.; Rogero, Jose Roberto [Instituto de Pesquisas Energeticas e Nucleares (IPEN/CNEN-SP), Sao Paulo, SP (Brazil)], e-mail: carolina_sm@hotmail.com; Ikeda, Tamiko I.; Cruz, Aurea S. [Instituto Adolfo Lutz, Sao Paulo, SP (Brazil)

    2009-07-01

    The present study was designed to evaluate the in vitro effect of gamma radiation in cell culture of mouse connective tissue exposed to different doses of gamma radiation and under several conditions. The cell viability was analyzed by neutral red uptake methodology. This assay was developed for establish a methodology to be used in the future in the study of resveratrol radioprotection. Resveratrol (3,4',5- trihydroxystilbene), a phenolic phytoalexin that occurs naturally in some spermatophytes, such as grapevines, in response to injury as fungal infections and exposure to ultraviolet light. In the wines this compound is found at high levels and is considered one of the highest antioxidant constituents. The intense antioxidant potential of resveratrol provides many pharmacological activities including cardioprotection, chemoprevention and anti-tumor effects. Our results demonstrated that {sup 60}Co gamma radiation lethal dose (LD50) on NCTC clone 929 cells was about 340Gy. (author)

  19. In vitro cell culture lethal dose submitted to gamma radiation

    International Nuclear Information System (INIS)

    Moreno, Carolina S.; Rogero, Sizue O.; Rogero, Jose Roberto; Ikeda, Tamiko I.; Cruz, Aurea S.

    2009-01-01

    The present study was designed to evaluate the in vitro effect of gamma radiation in cell culture of mouse connective tissue exposed to different doses of gamma radiation and under several conditions. The cell viability was analyzed by neutral red uptake methodology. This assay was developed for establish a methodology to be used in the future in the study of resveratrol radioprotection. Resveratrol (3,4',5- trihydroxystilbene), a phenolic phytoalexin that occurs naturally in some spermatophytes, such as grapevines, in response to injury as fungal infections and exposure to ultraviolet light. In the wines this compound is found at high levels and is considered one of the highest antioxidant constituents. The intense antioxidant potential of resveratrol provides many pharmacological activities including cardioprotection, chemoprevention and anti-tumor effects. Our results demonstrated that 60 Co gamma radiation lethal dose (LD50) on NCTC clone 929 cells was about 340Gy. (author)

  20. Sensitive radioimmunosorbent assay for the detection of plant viruses. [Cauliflower mosaic virus, lettuce mosaic virus

    Energy Technology Data Exchange (ETDEWEB)

    Ghabrial, S A; Shepherd, R J [Kentucky Univ., Lexington (USA); California Univ., Davis (USA))

    1980-06-01

    A simple and highly sensitive radioimmunosorbent assay (RISA) for the detection of plant viruses is described. The RISA procedure is a microplate method based on the principle of 'double-antibody sandwich' and follows essentially the protocol of the enzyme-linked immunosorbent assay (ELISA) (Clark and Adams, 1977), with the exception that /sup 125/I-labelled ..gamma..-globulin is substituted for the ..gamma..-globulin enzyme conjugate; the bound /sup 125/I-..gamma..-globulin is dissociated by acidification from the double-antibody sandwich. The radioactivity is proportional to virus concentration, and cauliflower mosaic virus (CaMV) and lettuce mosaic virus (LMV) could be detected at concentrations as low as 5 and 2 ng/ml, respectively. Direct evidence of the adverse effects of conjugation with enzyme on the binding abilities of antibodies is presented. The RISA procedure should prove valuable with viruses for which the ELISA values are too low to be dependable.

  1. Precise measurement of {gamma}(K{yields}e {nu}({gamma}))/{gamma}(K{yields}{mu} {nu}({gamma})) and study of K{yields}e {nu} {gamma}

    Energy Technology Data Exchange (ETDEWEB)

    Ambrosino, F.; Massarotti, P.; Meola, S.; Napolitano, M. [Dipartimento di Scienze Fisiche dell' Universita ' ' Federico II' ' , Napoli (Italy); INFN Sezione di Napoli, Napoli (Italy); Antonelli, A.; Antonelli, M.; Bencivenni, G.; Bloise, C.; Bossi, F.; Capon, G.; Capussela, T.; Ciambrone, P.; De Lucia, E.; De Simone, P.; Dreucci, M.; Felici, G.; Gatti, C.; Giovannella, S.; Jacewicz, M.; Lanfranchi, G.; Miscetti, S.; Moulson, M.; Murtas, F.; Palutan, M.; Santangelo, P.; Sciascia, B.; Sibidanov, A.; Spadaro, T.; Venanzoni, G. [Laboratori Nazionali di Frascati dell' INFN, Frascati (Italy); Archilli, F. [Dipartimento di Fisica dell' Universita ' ' Tor Vergata' ' , Rome (Italy); INFN Sezione di Roma Tor Vergata, Rome (Italy); Beltrame, P.; Denig, A.; Mueller, S. [Johannes Gutenberg-Universitaet, Institut fuer Kernphysik, Mainz (Germany); Bini, C.; De Santis, A.; De Zorzi, G.; Di Domenico, A.; Fiore, S.; Franzini, P.; Gauzzi, P. [Dipartimento di Fisica dell' Universita ' ' La Sapienza' ' , Rome (Italy); INFN Sezione di Roma, Rome (Italy); Bocchetta, S.; Ceradini, F.; Di Micco, B.; Nguyen, F. [Dipartimento di Fisica dell' Universita ' ' Roma Tre' ' , Rome (Italy); INFN Sezione di Roma Tre, Rome (Italy); Branchini, P.; Graziani, E.; Passeri, A.; Tortora, L. [INFN Sezione di Roma Tre, Rome (Italy); Capriotti, D. [Dipartimento di Fisica dell' Universita ' ' Roma Tre' ' , Rome (Italy); Di Donato, C. [INFN Sezione di Napoli, Napoli (Italy); Kulikov, V. [Institute for Theoretical and Experimental Physics, Moscow (Russian Federation); Lee-Franzini, J. [Laboratori Nazionali di Frascati dell' INFN, Frascati (Italy); State University of New York, Physics Department, Stony Brook (United States); Martini, M.; Patera, V.; Versaci, R. [Laboratori Nazionali di Frascati dell' INFN, Frascati (Italy); Dipartimento di Energetica dell' Universita ' ' La Sapienza' ' , Rome (Italy); Valente, P. [INFN Sezione di Roma, Rome (Italy)

    2009-12-15

    We present a precise measurement of the ratio R{sub K}={gamma}(K{yields}e{nu}({gamma}))/{gamma}(K{yields}{mu}{nu}({gamma})) and a study of the radiative process K{yields}e{nu}{gamma}, performed with the KLOE detector. The results are based on data collected at the Frascati e{sup +}e{sup -} collider DA {phi}NE for an integrated luminosity of 2.2 fb{sup -1}. We find R{sub K}=(2.493{+-}0.025{sub stat}{+-}0.019{sub syst}) x 10{sup -5}, in agreement with the Standard Model expectation. This result is used to improve constraints on parameters of the Minimal Supersymmetric Standard Model with lepton flavor violation. We also measured the differential decay rate d {gamma}(K{yields}e{nu}{gamma})/dE{sub {gamma}} for photon energies 10gamma}}<250 MeV. Results are compared with predictions from theory. (orig.)

  2. Feasibility of nondestructive assay measurements in uranium enrichment plants

    Energy Technology Data Exchange (ETDEWEB)

    Walton, R.B.

    1978-04-01

    Applications of nondestructive assay methods to measurement problems in uranium enrichment facilities are reviewed. The results of a number of test and evaluation projects that were performed over the last decade at ORGDP and Portsmouth are presented. Measurements of the residual holdup in the top enrichment portion of the shut-down K-25 cascade were made with portable neutron and gamma-ray detectors, and inventory estimates based on these data were in good agreement with ORGDP estimates. In the operating cascade, the tests showed that portable NaI detectors are effective for monitoring NaF and alumina media for gaseous effluent traps and that gas phase enrichments and inventories, as well as large deposits of uranium, can be detected with portable neutron and gamma-ray instrumentation. A wide variety of scrap and waste materials, including barrier and compressor blades, incinerator ash and trapping media, and miscellaneous waste, were measured using passive gamma-ray and neutron methods and 14-MeV neutron interrogation. Methods developed for rapid verification of UF/sub 6/ in shipping containers with portable neutron and gamma-ray instruments are now used routinely by safeguards inspectors. Passive assay methods can also be used to measure continuously the enrichments of /sup 235/U and /sup 234/U in the UF/sub 6/ product and tails withdrawals of a gaseous diffusion plant. A system that was developed and installed in the extended-range product withdrawal station of the Portsmouth facility measures enrichment with a relative accuracy of 0.5%. A stand-alone neutron detector has also been successfully evaluated for the measurement of the isotopic abundance of /sup 234/U in UF/sub 6/ in sample cylinders, an application of potential importance to Minor Isotope Safeguards Technology. Recommendations are made on the role of NDA measurements for enrichment plant safeguards, including additional tests and evaluations that may be needed, particularly for advanced uranium

  3. Genotoxicological safety of the ethanol extract from seafood cooking drips by gamma irradiation

    International Nuclear Information System (INIS)

    Kim, Hyun Joo; Choi, Jong Il; Lee, Hee Sub; Kim, Jae Hun; Byun, Myung Woo; Chun, Byung Soo; Ahn, Dong Hyun; Yook, Hong Sun; Kim, Kee Hyuk

    2008-01-01

    Although seafood cooking drips were the byproducts from the fishery industry it was known that the cooking drips had many nutrients and could be used as functional materials. Previously, the physiological properties of cooking drips were shown to be increased by a gamma irradiation. But, there was no report on the safe for the genotoxicity on the irradiation. In this study, the genotoxicity of the cooking drips from Hizikia fusiformis, Enteroctopus dofleni and Thunnus thynnus was evaluated by the Ames test (Salmonella typhimurium reversion assay) and the SOS chromotest. The results from all samples were negative in the bacterial reversion assay with S. typhimurium TA98, TA100. No mutagenicity was detected in the assay, both with and without metabolic activation. The SOS chromotest also indicated that the gamma-irradiated seafood cooking drips did not show any mutagenicity. Therefore, this study indicated that gamma irradiation could be used for the hygiene, functional properties and processibility of seafood cooking drips

  4. Usefulness of radiatively obtained acrylamide polymers for production of drug forms with controlled release of the therapeutic component

    International Nuclear Information System (INIS)

    Mosiniak, T.; Switek, W.

    1988-01-01

    Using 60 Co gamma radiation as a factor initiating polymerization and cross-linking of polymers, polyacrylamide matrices were formed with the following therapeutic agents: aspirin, amidopyrin, sodium salicylate. Gamma radiation doses ranged from 3.5 to 22.5 kGy, dose rate was 0.138 Gy x s -1 . Kinetics of the therapeutic agent release from the matrix polymers was determined by measurement of per cent of the drug release in the course of time and calculations of release rate constants. The preparations containing slowly released drugs were obtained. 12 figs., 2 tabs., 11 refs. (author)

  5. Quantitative assay for the measurement of immune responses directed against the human placenta

    Energy Technology Data Exchange (ETDEWEB)

    Davies, M; Sutcliffe, R G [Glasgow Univ. (UK)

    1982-02-12

    A quantitative in vitro immune assay based on the classical chromium release assay has been developed to detect immune responses directed against alien antigens expressed by the developing foetus and present on the maternal-facing surface of the human placenta. A plasma membrane fraction from the surface of the placenta was prepared and the vesicles thus formed were radiolabelled with /sup 51/Cr. The /sup 51/Cr-labelled vesicles, by various criteria, were found to be suitable for use as targets in a release assay. Further, by means of experimentally immunised animals, the target membranes were shown to be capable of detecting both cellular and humoral anti-placental activity.

  6. Performance validation of commercially available mobile waste-assay systems: Preliminary report

    Energy Technology Data Exchange (ETDEWEB)

    Schanfein, M.; Bonner, C.; Maez, R. [Los Alamos National Lab., NM (United States)] [and others

    1997-11-01

    Prior to disposal, nuclear waste must be accurately characterized to identify and quantify the radioactive content to reduce the radioactive hazard to the public. Validation of the waste-assay systems` performance is critical for establishing the credibility of the assay results for storage and disposal purposes. Canberra Nuclear has evaluated regulations worldwide and identified standard, modular, neutron- and gamma-waste-assay systems that can be used to characterize a large portion of existing and newly generated transuranic (TRU) and low-level waste. Before making claims of guaranteeing any system`s performance for specific waste types, the standardized systems` performance be evaluated. 7 figs., 11 tabs.

  7. Performance validation of commercially available mobile waste-assay systems: Preliminary report

    International Nuclear Information System (INIS)

    Schanfein, M.; Bonner, C.; Maez, R.

    1997-01-01

    Prior to disposal, nuclear waste must be accurately characterized to identify and quantify the radioactive content to reduce the radioactive hazard to the public. Validation of the waste-assay systems' performance is critical for establishing the credibility of the assay results for storage and disposal purposes. Canberra Nuclear has evaluated regulations worldwide and identified standard, modular, neutron- and gamma-waste-assay systems that can be used to characterize a large portion of existing and newly generated transuranic (TRU) and low-level waste. Before making claims of guaranteeing any system's performance for specific waste types, the standardized systems' performance be evaluated. 7 figs., 11 tabs

  8. Nondestructive assay of subassemblies of various spent or fresh fuels by active neutron interrogation

    International Nuclear Information System (INIS)

    Ragan, G.L.; Ricker, C.W.; Chiles, M.M.; Ingersoll, D.T.; Slaughter, G.G.

    1979-01-01

    Recent studies show that subassemblies containing various spent fuels could be assayed rapidly and accurately by a nondestructive assay system using active neutron interrogation and prompt-neutron detection. Subassembly penetration is achieved by 24-keV (Sb--Be) interrogation neutrons; the spent-fuel neutron background is overridden by using strong interrogating sources and prompt-neutron signals, and background gammas are absorbed by lead. Experiments have demonstrated the potential for assaying with better than 5% accuracy, three spent plutonium-fueled subassemblies per hour. Calculations, validated by experiments, predict even better performance for fresh or uranium-fueled subassemblies; several performance estimates are given

  9. Fully automated laboratory for the assay of plutonium in wastes and recoverable scraps

    International Nuclear Information System (INIS)

    Guiberteau, P.; Michaut, F.; Bergey, C.; Debruyne, T.

    1990-01-01

    To determine the plutonium content of wastes and recoverable scraps in intermediate size containers (ten liters) an automated laboratory has been carried out. Two passive methods of measurement are used. Gamma ray spectrometry allows plutonium isotopic analysis, americium determination and plutonium assay in wastes and poor scraps. Calorimetry is used for accurate (± 3%) plutonium determination in rich scraps. A full automation was realized with a barcode management and a supply robot to feed the eight assay set-ups. The laboratory works on a 24 hours per day and 365 days per year basis and has a capacity of 8,000 assays per year

  10. Large scientific releases

    International Nuclear Information System (INIS)

    Pongratz, M.B.

    1981-01-01

    The motivation for active experiments in space is considered, taking into account the use of active techniques to obtain a better understanding of the natural space environment, the utilization of the advantages of space as a laboratory to study fundamental plasma physics, and the employment of active techniques to determine the magnitude, degree, and consequences of artificial modification of the space environment. It is pointed out that mass-injection experiments in space plasmas began about twenty years ago with the Project Firefly releases. Attention is given to mass-release techniques and diagnostics, operational aspects of mass release active experiments, the active observation of mass release experiments, active perturbation mass release experiments, simulating an artificial modification of the space environment, and active experiments to study fundamental plasma physics

  11. Effect of gamma-irradiation on biodegradable microspheres loaded with rasagiline mesylate

    International Nuclear Information System (INIS)

    Fernandez, Marcos; Barcia, Emilia; Negro, Sofia

    2016-01-01

    In the present study, the influence of gamma-irradiation was evaluated on the physicochemical characteristics and in vitro release of rasagiline mesylate (RM), a selective MAO-B inhibitor used in Parkinson's disease, from poly(D,L-lactide-co-glycolide) (PLGA) microspheres. Microspheres were prepared using PLGA 50:50 by the solvent evaporation technique (O/W emulsion). Microspheres were sterilized by gamma-irradiation and their influence was assessed by scanning electron microscopy (SEM), laser light diffraction, differential scanning calorimetry (DSC), X-ray diffraction (XRD), gel permeation chromatography (GPC), encapsulation efficiency (EE) and in vitro drug release. Gamma-irradiation of RM-loaded microspheres did not affect EE, DSC and XRD patterns. After gamma-irradiation, changes on the surface were observed by SEM, but no significant difference in mean particle size was observed. GPC measurements showed a decrease in molecular weight of the polymer after five days of in vitro release. The similarity factor value between irradiated and non-irradiates microspheres was <50, indicating the non-similarity of the release profiles. The sterilization technique had an effect on the integrity of polymeric system, significantly affecting in vitro release of RM from PLGA microspheres. Therefore, from our results we conclude that gamma-irradiation is not a suitable sterilization procedure for this formulation

  12. Gamma counter calibration system

    International Nuclear Information System (INIS)

    1977-01-01

    A method and apparatus are described for the calibration of a gamma radiation measurement instrument to be used over any of a number of different absolute energy ranges. The method includes the steps of adjusting the overall signal gain associated with pulses which are derived from detected gamma rays, until the instrument is calibrated for a particular absolute energy range; then storing parameter settings corresponding to the adjusted overall signal gain, and repeating the process for other desired absolute energy ranges. The stored settings can be subsequently retrieved and reapplied so that test measurements can be made using a selected one of the absolute energy ranges. Means are provided for adjusting the overall signal gain and a specific technique is disclosed for making coarse, then fine adjustments to the signal gain, for rapid convergence of the required calibration settings. (C.F.)

  13. Gamma-ray bursts

    CERN Document Server

    Wijers, Ralph A M J; Woosley, Stan

    2012-01-01

    Cosmic gamma ray bursts (GRBs) have fascinated scientists and the public alike since their discovery in the late 1960s. Their story is told here by some of the scientists who participated in their discovery and, after many decades of false starts, solved the problem of their origin. Fourteen chapters by active researchers in the field present a detailed history of the discovery, a comprehensive theoretical description of GRB central engine and emission models, a discussion of GRB host galaxies and a guide to how GRBs can be used as cosmological tools. Observations are grouped into three sets from the satellites CGRO, BeppoSAX and Swift, and followed by a discussion of multi-wavelength observations. This is the first edited volume on GRB astrophysics that presents a fully comprehensive review of the subject. Utilizing the latest research, Gamma-ray Bursts is an essential desktop companion for graduate students and researchers in astrophysics.

  14. Gamma ray camera

    International Nuclear Information System (INIS)

    Wang, S.-H.; Robbins, C.D.

    1979-01-01

    An Anger gamma ray camera is improved by the substitution of a gamma ray sensitive, proximity type image intensifier tube for the scintillator screen in the Anger camera. The image intensifier tube has a negatively charged flat scintillator screen, a flat photocathode layer, and a grounded, flat output phosphor display screen, all of which have the same dimension to maintain unit image magnification; all components are contained within a grounded metallic tube, with a metallic, inwardly curved input window between the scintillator screen and a collimator. The display screen can be viewed by an array of photomultipliers or solid state detectors. There are two photocathodes and two phosphor screens to give a two stage intensification, the two stages being optically coupled by a light guide. (author)

  15. Gamma camera system

    International Nuclear Information System (INIS)

    Miller, D.W.; Gerber, M.S.; Schlosser, P.A.; Steidley, J.W.

    1980-01-01

    A detailed description is given of a novel gamma camera which is designed to produce superior images than conventional cameras used in nuclear medicine. The detector consists of a solid state detector (e.g. germanium) which is formed to have a plurality of discrete components to enable 2-dimensional position identification. Details of the electronic processing circuits are given and the problems and limitations introduced by noise are discussed in full. (U.K.)

  16. Scanning gamma camera

    International Nuclear Information System (INIS)

    Engdahl, L.W.; Batter, J.F. Jr.; Stout, K.J.

    1977-01-01

    A scanning system for a gamma camera providing for the overlapping of adjacent scan paths is described. A collimator mask having tapered edges provides for a graduated reduction in intensity of radiation received by a detector thereof, the reduction in intensity being graduated in a direction normal to the scanning path to provide a blending of images of adjacent scan paths. 31 claims, 15 figures

  17. A gamma scintillation spectrometer

    Energy Technology Data Exchange (ETDEWEB)

    Symbalisty, S

    1952-07-01

    A scintillation type gamma ray spectrometer employing coincidence counting, designed and built at the Physics Department of the University of Western Ontario is described. The spectrometer is composed of two anthracene and photomultiplier radiation detectors, two pulse analyzing channels, a coincidence stage, three scalers and a high voltage stabilized supply. A preliminary experiment to test the operation of the spectrometer was performed and the results of this test are presented. (author)

  18. Gamma camera display system

    International Nuclear Information System (INIS)

    Stout, K.J.

    1976-01-01

    A gamma camera having an array of photomultipliers coupled via pulse shaping circuitry and a resistor weighting circuit to a display for forming an image of a radioactive subject is described. A linearizing circuit is coupled to the weighting circuit, the linearizing circuit including a nonlinear feedback circuit with diode coupling to the weighting circuit for linearizing the correspondence between points of the display and points of the subject. 4 Claims, 5 Drawing Figures

  19. Preservation and gamma irradiation

    International Nuclear Information System (INIS)

    Ramiere, R.

    1991-01-01

    The paper reviews briefly the application of gamma radiation to preservation of cultural objects for disinsectization, disinfection and strengthening of materials such as wood or stone by impregnation with a liquid resin and in situ polymerization. As heavy equipment is required two facilities are specialized a 1000 T Bq cobalt 60 source at Grenoble (France) and 100 T Bq one at Rostoky (Czechoslovakia). Examples of treated objects are given [fr

  20. Gamma radiation in apartments

    International Nuclear Information System (INIS)

    Grindborg, J.-E.

    1983-05-01

    This investigation forms the basis for the description of methods for the detection of gamma radiation. The aim is to control that the dose limit will not exceed 50 μR/h in a room where people reside. The distribution of dose rates in different rooms has been calculated and the results have been compared with experimental data. Various instruments have been calibrated and their specifications are discussed. (G.B.)

  1. Mutagenicity of irradiated food in the host mediated assay system

    International Nuclear Information System (INIS)

    Johnston-Arthur, T.; Turanitz, K.; Hruby, R.; Stehlik, G.; Brena-Valle, M.

    1975-01-01

    Groups of Swiss albino mice (SPF) fed with normal and gamma-irradiated food at doses of 0.75, 1.5 and 3.0 Mrad, were injected intraperitoneally with SALMONELLA TYPHIMURIUM TA 1530 for the host mediated assay test of mutagenesis. The mutation frequency was calculated in terms of the number of mutant colonies per unit number of surviving cells. The results indicate that there is a significant increase in mutation frequency induced by the 3 Mrad sterilized food. No difference was observed in the 0.75 Mrad dose when compared with the control

  2. On the efficiency calibration of a drum waste assay system

    CERN Document Server

    Dinescu, L; Cazan, I L; Macrin, R; Caragheorgheopol, G; Rotarescu, G

    2002-01-01

    The efficiency calibration of a gamma spectroscopy waste assay system, constructed by IFIN-HH, was performed. The calibration technique was based on the assumption of a uniform distribution of the source activity in the drum and also a uniform sample matrix. A collimated detector (HPGe--20% relative efficiency) placed at 30 cm from the drum was used. The detection limit for sup 1 sup 3 sup 7 Cs and sup 6 sup 0 Co is approximately 45 Bq/kg for a sample of about 400 kg and a counting time of 10 min. A total measurement uncertainty of -70% to +40% was estimated.

  3. Gamma surgery for hemangiopericytomas

    International Nuclear Information System (INIS)

    Payne, B.R.; Prasad, D.; Steiner, M.; Steiner, L.

    2000-01-01

    A retrospective analysis of a consecutive series of 12 patients with 15 intracranial hemangiopericytomas treated at the University of Virginia using gamma surgery is presented. Clinical and radiographic follow up of 3 to 56 months is available for 10 patients with 12 tumors. There was one tumor present at the time of initial gamma surgery in each patient. Two new tumors occurred in patients previously treated. Nine of the tumors decreased in volume and three remained stable. Four of the nine tumors that shrank later progressed at an average of 22 months after treatment. Of the tumors that decreased in volume and have not progressed, the response has been for an average of 11 months. The follow-up for two tumors that remained unchanged was 10 and 34 months (average 22 months). A third tumor was unchanged at 42 months but the patient died of new disease adjacent to the treated area in the anterior skull base. There were no complications and the quality of life following the procedure was maintained or improved in every case. Gamma surgery is effective in palliating the patients by decreasing tumor volume and delaying recurrence. (author)

  4. gamma. radiation of ionium

    Energy Technology Data Exchange (ETDEWEB)

    Curie, I

    1948-12-08

    Following the work of Ward (Proc Cambridge Phil Soc 35 322(1939)), the ..gamma..-radiation of ionium (from an IoTh preparation) was studied with the aid of Ta and W screens, and an aluminum counter. The screen measurements confirmed Ward's findings of two radiations, of 68 keV and of about 200 keV. The number of quanta per second of each radiation was determined with the counter, which has been calibrated on certain L lines of radium. The global quanta number of L lines of ionium was also determined. The results were as follows: 0.7 quanta ..gamma.. of 68 keV for 100 ..cap alpha..-particles; 0.2 quanta ..gamma.. of 200 keV for 100 ..cap alpha..-particles; 10 quanta L for 100 ..cap alpha..-particles. These data, which show an important internal conversion, agree with the findings of Teillac (Compt Rend 227 1227 (1948)), who investigated the ..beta..-radiation of ionium. It is the radiation 68 keV which is highly converted. On the other hand, these results do no agree with the data on the fine structure of ionium found by Rosenblum, Valadares, and Vial (Compt Rend 227 1088(1948)).

  5. Apparatus for gamma radiography

    International Nuclear Information System (INIS)

    1983-06-01

    The aim of the present standard is to fix the rules for the construction of gamma radiography instrumentation without prejudice to the present regulations. These apparatus have to be fitted with only sealed sources conformable to the experimental standard M 61-002. The present standard agrees with the international standard ISO 3999 of 1977 dealing with the same subject. Nevertheless, it is different on the three main following points: it does not accept the same limits of absorbed dose rates in the air calculated on the external surface of projectors; it precribes tightness, bending, crushing and tensile tests for some components of the gamma radiography it prescribes tests of endurance and resistance to breaking for the locking systems of the gamma radiography apparatus. The present standard also specifies the following points: symbols and indications to put on projectors and on the source-holder; identification of the source contained in the projector; and, accompanying documents. The regulation references are given in annexe [fr

  6. Biohydrogen production using waste activated sludge disintegrated by gamma irradiation

    International Nuclear Information System (INIS)

    Yin, Yanan; Wang, Jianlong

    2015-01-01

    Highlights: • The waste activated sludge could be disintegrated by gamma irradiation. • The disintegrated sludge could be used for biohydrogen production. • Combined alkali-irradiation treatment achieved the highest solubilization of sludge. - Abstract: The biohydrogen production using the disintegrated and dissolved sludge by gamma irradiation was studied. The experimental results showed that gamma irradiation and irradiation combined with alkali pretreatment could disintegrate and dissolve waste activated sludge for biohydrogen production. The alkali-irradiation treatment of the sludge at pH = 12 and 20 kGy achieved the highest disintegration and dissolution, i.e., it could destroy the cell walls and release organic matters (such as soluble COD, polysaccharides and protein) into the solution. The disintegrated sludge could be used as a low-cost substrate for biohydrogen production

  7. Measurement of gamma radiation doses in nuclear power plant environment

    International Nuclear Information System (INIS)

    Bochvar, I.A.; Keirim-Markus, I.B.; Sergeeva, N.A.

    1976-01-01

    Considered are the problems of measuring gamma radiation dose values and the dose distribution in the nuclear power plant area with the aim of estimating the extent of their effect on the population. Presented are the dosimeters applied, their distribution throughout the controlled area, time of measurement. The distribution of gamma radiation doses over the controlled area and the dose alteration with the increase of the distance from the release source are shown. The results of measurements are investigated. The conclusion is made that operating nuclear power plants do not cause any increase in the gamma radiation dose over the area. Recommendations for clarifying the techniques for using dose-meters and decreasing measurement errors are given [ru

  8. Assaying Cellular Viability Using the Neutral Red Uptake Assay.

    Science.gov (United States)

    Ates, Gamze; Vanhaecke, Tamara; Rogiers, Vera; Rodrigues, Robim M

    2017-01-01

    The neutral red uptake assay is a cell viability assay that allows in vitro quantification of xenobiotic-induced cytotoxicity. The assay relies on the ability of living cells to incorporate and bind neutral red, a weak cationic dye, in lysosomes. As such, cytotoxicity is expressed as a concentration-dependent reduction of the uptake of neutral red after exposure to the xenobiotic under investigation. The neutral red uptake assay is mainly used for hazard assessment in in vitro toxicology applications. This method has also been introduced in regulatory recommendations as part of 3T3-NRU-phototoxicity-assay, which was regulatory accepted in all EU member states in 2000 and in the OECD member states in 2004 as a test guideline (TG 432). The present protocol describes the neutral red uptake assay using the human hepatoma cell line HepG2, which is often employed as an alternative in vitro model for human hepatocytes. As an example, the cytotoxicity of acetaminophen and acetyl salicylic acid is assessed.

  9. Calculation method for gamma dose rates from Gaussian puffs

    International Nuclear Information System (INIS)

    Thykier-Nielsen, S.; Deme, S.; Lang, E.

    1995-06-01

    The Lagrangian puff models are widely used for calculation of the dispersion of releases to the atmosphere. Basic output from such models is concentration of material in the air and on the ground. The most simple method for calculation of the gamma dose from the concentration of airborne activity is based on the semi-infinite cloud model. This method is however only applicable for puffs with large dispersion parameters, i.e. for receptors far away from the release point. The exact calculation of the cloud dose using volume integral requires large computer time usually exceeding what is available for real time calculations. The volume integral for gamma doses could be approximated by using the semi-infinite cloud model combined with correction factors. This type of calculation procedure is very fast, but usually the accuracy is poor because only a few of the relevant parameters are considered. A multi-parameter method for calculation of gamma doses is described here. This method uses precalculated values of the gamma dose rates as a function of E γ , σ y , the asymmetry factor - σ y /σ z , the height of puff center - H and the distance from puff center R xy . To accelerate the calculations the release energy, for each significant radionuclide in each energy group, has been calculated and tabulated. Based on the precalculated values and suitable interpolation procedure the calculation of gamma doses needs only short computing time and it is almost independent of the number of radionuclides considered. (au) 2 tabs., 15 ills., 12 refs

  10. Labeling of human immune gamma globulin with sup(99m)Tc

    International Nuclear Information System (INIS)

    Wong, D.W.; Huang, J.T.

    1977-01-01

    Human immune serum gamma globulin and rabbit anti-Stap. aureus antibody have been successfully labeled with sup(99m)Tc at pH 7.4 with an average binding efficiency of 86 and 82%, respectively. The labeled proteins behave similarly to unlabeled gamma-globulin fraction in the normal human serum as demonstrated by protein electrophoresis. The biological half-time of sup(99m)Tc-gamma-globulin in dog has been determined to be 54 min for the fast component and 14.7 hr for a slower component. Immunological assays demonstrate no significant change in antibody activity after labeling process. (author)

  11. A laboratory-scale pretreatment and hydrolysis assay for determination of reactivity in cellulosic biomass feedstocks.

    Science.gov (United States)

    Wolfrum, Edward J; Ness, Ryan M; Nagle, Nicholas J; Peterson, Darren J; Scarlata, Christopher J

    2013-11-14

    The rapid determination of the release of structural sugars from biomass feedstocks is an important enabling technology for the development of cellulosic biofuels. An assay that is used to determine sugar release for large numbers of samples must be robust, rapid, and easy to perform, and must use modest amounts of the samples to be tested.In this work we present a laboratory-scale combined pretreatment and saccharification assay that can be used as a biomass feedstock screening tool. The assay uses a commercially available automated solvent extraction system for pretreatment followed by a small-scale enzymatic hydrolysis step. The assay allows multiple samples to be screened simultaneously, and uses only ~3 g of biomass per sample. If the composition of the biomass sample is known, the results of the assay can be expressed as reactivity (fraction of structural carbohydrate present in the biomass sample released as monomeric sugars). We first present pretreatment and enzymatic hydrolysis experiments on a set of representative biomass feedstock samples (corn stover, poplar, sorghum, switchgrass) in order to put the assay in context, and then show the results of the assay applied to approximately 150 different feedstock samples covering 5 different materials. From the compositional analysis data we identify a positive correlation between lignin and structural carbohydrates, and from the reactivity data we identify a negative correlation between both carbohydrate and lignin content and total reactivity. The negative correlation between lignin content and total reactivity suggests that lignin may interfere with sugar release, or that more mature samples (with higher structural sugars) may have more recalcitrant lignin. The assay presented in this work provides a robust and straightforward method to measure the sugar release after pretreatment and saccharification that can be used as a biomass feedstock screening tool. We demonstrated the utility of the assay by

  12. The fluorometric microculture cytotoxicity assay.

    Science.gov (United States)

    Lindhagen, Elin; Nygren, Peter; Larsson, Rolf

    2008-01-01

    The fluorometric microculture cytotoxicity assay (FMCA) is a nonclonogenic microplate-based cell viability assay used for measurement of the cytotoxic and/or cytostatic effect of different compounds in vitro. The assay is based on hydrolysis of the probe, fluorescein diacetate (FDA) by esterases in cells with intact plasma membranes. The assay is available as both a semiautomated 96-well plate setup and a 384-well plate version fully adaptable to robotics. Experimental plates are prepared with a small amount of drug solution and can be stored frozen. Cells are seeded on the plates and cell viability is evaluated after 72 h. The protocol described here is applicable both for cell lines and freshly prepared tumor cells from patients and is suitable both for screening in drug development and as a basis for a predictive test for individualization of anticancer drug therapy.

  13. P53 suppresses expression of the 14-3-3gamma oncogene

    Directory of Open Access Journals (Sweden)

    Qi Wenqing

    2011-08-01

    Full Text Available Abstract Background 14-3-3 proteins are a family of highly conserved proteins that are involved in a wide range of cellular processes. Recent evidence indicates that some of these proteins have oncogenic activity and that they may promote tumorigenesis. We previously showed that one of the 14-3-3 family members, 14-3-3gamma, is over expressed in human lung cancers and that it can induce transformation of rodent cells in vitro. Methods qRTPCR and Western blot analysis were performed to examine 14-3-3gamma expression in non-small cell lung cancers (NSCLC. Gene copy number was analyzed by qPCR. P53 mutations were detected by direct sequencing and also by western blot. CHIP and yeast one hybrid assays were used to detect p53 binding to 14-3-3gamma promoter. Results Quantitative rtPCR results showed that the expression level of 14-3-3gamma was elevated in the majority of NSCLC that we examined which was also consistent with protein expression. Further analysis of the expression pattern of 14-3-3gamma in lung tumors showed a correlation with p53 mutations suggesting that p53 might suppress 14-3-3 gamma expression. Analysis of the gamma promoter sequence revealed the presence of a p53 consensus binding motif and in vitro assays demonstrated that wild-type p53 bound to this motif when activated by ionizing radiation. Deletion of the p53 binding motif eliminated p53's ability to suppress 14-3-3gamma expression. Conclusion Increased expression of 14-3-3gamma in lung cancer coincides with loss of functional p53. Hence, we propose that 14-3-3gamma's oncogenic activities cooperate with loss of p53 to promote lung tumorigenesis.

  14. Characterization of acute undifferentiated leukemia by combined analysis of plasma membrane-associated gamma-glutamyltranspeptidase and soluble terminal transferase.

    Science.gov (United States)

    Heumann, D; Losa, G; Barras, C; Morell, A; von Fliedner, V

    1985-08-01

    gamma-Glutamyltranspeptidase (gamma-GT) is a plasma membrane-associated enzyme present in blasts of certain acute leukemias. We analyzed 90 cases of undifferentiated and differentiated acute leukemias for gamma-GT, using a colorimetric assay. Blasts of all patients with common acute lymphoblastic leukemia (ALL) and T-ALL were negative for gamma-GT (less than 5 units). In contrast, gamma-GT was significantly elevated in acute myeloblastic or monoblastic leukemia blasts (P less than .001). In 16 cases of acute undifferentiated leukemia (AUL) studied, the levels of gamma-GT ranged from 0 to 93 units; in eight cases, gamma-GT was positive (greater than 5 units), and six of these had 2% to 5% Sudan black-positive leukemic cells in the blast-enriched suspension. Combined gamma-GT/TdT analysis revealed that both enzyme markers were mutually exclusive in 75% of AUL cases, suggesting that gamma-GT+/TdT-blasts are of nonlymphoid origin, and gamma-GT-/TdT+ blasts are of lymphoid origin. Two cases were devoid of both enzyme activities and could represent truly undifferentiated leukemia. Thus, combined gamma-GT/TdT analysis underlines the heterogeneity of AUL and appears to be useful in defining the lineage commitment of undifferentiated leukemic blasts.

  15. Lunar based gamma ray astronomy

    International Nuclear Information System (INIS)

    Haymes, R.C.

    1985-01-01

    Gamma ray astronomy represents the study of the universe on the basis of the electromagnetic radiation with the highest energy. Gamma ray astronomy provides a crucial tool for the understanding of astronomical phenomena, taking into account nucleosynthesis in supernovae, black holes, active galaxies, quasars, the sources of cosmic rays, neutron stars, and matter-antimatter annihilation. Difficulties concerning the conduction of studies by gamma ray astronomy are related to the necessity to perform such studies far from earth because the atmosphere is a source of gamma rays. Studies involving the use of gamma ray instruments in earth orbit have been conducted, and more gamma ray astronomy observations are planned for the future. Imperfections of studies conducted in low earth orbit could be overcome by estalishing an observatory on the moon which represents a satellite orbiting at 60 earth radii. Details concerning such an observatory are discussed. 5 references

  16. Trace metal assay of uranium silicide fuel

    International Nuclear Information System (INIS)

    Kulkarni, M.J.; Argekar, A.A.; Thulasidas, S.K.; Dhawale, B.A.; Rajeswari, B.; Adya, V.C.; Purohit, P.J.; Neelam, G.; Bangia, T.R.; Page, A.G.; Sastry, M.D.; Iyer, R.H.

    1994-01-01

    A comprehensive trace metal assay of uranium silicide, a fuel for nuclear research reactors that employs low-enrichment uranium, is carried out by atomic spectrometry. Of the list of specification elements, 21 metallic elements are determined by a direct current (dc) arc carrier distillation technique; the rare earths yttrium and zirconium are chemically separated from the major matrix followed by a dc arc/inductively coupled argon plasma (ICP) excitation technique in atomic emission spectrometry (AES); silver is determined by electrothermal atomization-atomic absorption spectrometry (ETA-AAS) without prior chemical separation of the major matrix. Gamma radioactive tracers are used to check the recovery of rare earths during the chemical separation procedure. The detection limits for trace metallics vary in the 0.1- to 40-ppm range. The precision of the determinations as evaluated from the analysis of the synthetic sample with intermediate range analyte concentration is better than 25% relative standard deviation (RSD) for most of the elements employing dc arc-AES, while that for silver determination by ETS-AAS is 10% RSD. The precision of the determinations for four crucially important rare earths by ICP-AES is better than 3% RSD

  17. The 2017 Release Cloudy

    Science.gov (United States)

    Ferland, G. J.; Chatzikos, M.; Guzmán, F.; Lykins, M. L.; van Hoof, P. A. M.; Williams, R. J. R.; Abel, N. P.; Badnell, N. R.; Keenan, F. P.; Porter, R. L.; Stancil, P. C.

    2017-10-01

    We describe the 2017 release of the spectral synthesis code Cloudy, summarizing the many improvements to the scope and accuracy of the physics which have been made since the previous release. Exporting the atomic data into external data files has enabled many new large datasets to be incorporated into the code. The use of the complete datasets is not realistic for most calculations, so we describe the limited subset of data used by default, which predicts significantly more lines than the previous release of Cloudy. This version is nevertheless faster than the previous release, as a result of code optimizations. We give examples of the accuracy limits using small models, and the performance requirements of large complete models. We summarize several advances in the H- and He-like iso-electronic sequences and use our complete collisional-radiative models to establish the densities where the coronal and local thermodynamic equilibrium approximations work.

  18. EIA new releases

    International Nuclear Information System (INIS)

    1994-09-01

    This report is a compliation of news releases from the Energy Information Administration. The september-october report includes articles on energy conservation, energy consumption in commercial buildings, and a short term energy model for a personal computer

  19. Radioligand assay in reproductive biology

    International Nuclear Information System (INIS)

    Korenman, S.G.; Sherman, B.M.

    1975-01-01

    Radioligand assays have been developed for the principal reproductive steroids and peptide hormones. Specific binding reagents have included antibodies, plasma binders, and intracellular receptors. In each assay, problems of specificity, sensitivity, and nonspecific inhibitors were encountered. Many features of the endocrine physiology in childhood, during puberty, and in adulthood have been characterized. Hormonal evaluations of endocrine disorders of reproduction are characterized on the basis of their characteristic pathophysiologic alterations. (U.S.)

  20. Regulations providing for the inspection of gamma radiography equipment

    International Nuclear Information System (INIS)

    1981-01-01

    Pursuant to the 1938 Act on X-rays and radium, etc and the 1976 regulations on supervision and use of installations and apparatus which release radiation representing a hazard to health, the State Institute of Radiation Health issued these regulations providing for a system of periodic inspections of gamma radiography equipment for radiation protection purposes. They entered into force on 1 July 1981 [fr