Tc1 mouse model of trisomy-21 dissociates properties of short- and long-term recognition memory.

Science.gov (United States)

Hall, Jessica H; Wiseman, Frances K; Fisher, Elizabeth M C; Tybulewicz, Victor L J; Harwood, John L; Good, Mark A

2016-04-01

The present study examined memory function in Tc1 mice, a transchromosomic model of Down syndrome (DS). Tc1 mice demonstrated an unusual delay-dependent deficit in recognition memory. More specifically, Tc1 mice showed intact immediate (30sec), impaired short-term (10-min) and intact long-term (24-h) memory for objects. A similar pattern was observed for olfactory stimuli, confirming the generality of the pattern across sensory modalities. The specificity of the behavioural deficits in Tc1 mice was confirmed using APP overexpressing mice that showed the opposite pattern of object memory deficits. In contrast to object memory, Tc1 mice showed no deficit in either immediate or long-term memory for object-in-place information. Similarly, Tc1 mice showed no deficit in short-term memory for object-location information. The latter result indicates that Tc1 mice were able to detect and react to spatial novelty at the same delay interval that was sensitive to an object novelty recognition impairment. These results demonstrate (1) that novelty detection per se and (2) the encoding of visuo-spatial information was not disrupted in adult Tc1 mice. The authors conclude that the task specific nature of the short-term recognition memory deficit suggests that the trisomy of genes on human chromosome 21 in Tc1 mice impacts on (perirhinal) cortical systems supporting short-term object and olfactory recognition memory. Copyright © 2016 The Authors. Published by Elsevier Inc. All rights reserved.

Lung scintigraphy with Tc-99m-MIBI in diagnosis of active tuberculosis

International Nuclear Information System (INIS)

Raziei, G.; Fotouhi, F.; Masjedi, M.R.; Neshandar, E.

2002-01-01

Tuberculosis is highly contagious infection and one of the most important health problems in the world today, particularly in our country. Routine diagnostic procedures are sometimes unable to differentiated active from inactive cases particularly in elderly. Children, immunomedics patients, Chronic cases with recurrent actuate infection and in the patients unable to provide sputum for microbiological studies. Several radiopharmaceuticals have been used in the evaluation of active pulmonary TB. In this study Tc 99 m-MIBI lung scan was performed using a single head ADAC gamma camera. 62 patients including 34 APTB 915 male and 19 female) and 28 IPTB 99 male and 19 female) underwent six minutes anterior and posterior chest images 20 and minutes after injection of 10 mCi (370 MBq) of Tc 99 m-MIBI. Visual grading was generated by comparing uptake of lesion with neck soft tissue (sternoleidomastoid muscle) and myocardium. For semiquantitative analysis, regions of interest were draw over the lesion (L), non lesion (NL) and neck soft tissue (SCM) and mean count value of ROIs as well as L/NL, L/SCM values were obtained. Results: From 34 patients with APTB, 4 PTS had normal lung uptake (11.7%), 14 PTs+(41, 2%), 14 PTs++41.2%) and 2 PTS +++ (5.9%), therefore 30 PTs of APTB were positive in scintigraphy (88.2%). From 28 patients with IPTB 21 PTs had normal lung uptake (75%), 6 PTs+ (21.4%) and one PT ++ (3.5%). In the semi quantitative study L/NL ratio is calculated for + about 1.35 +/-0.15 and below from this range is considered with normal limit. The sensitivity, specificity, accuracy, PPV and NPV were 88.2% 75%, 82.2%, 81.1% and 84% respectively. From 100 CXR lesion in APTB, 60 had compatible positive scan and from 86 CXR lesions in IPTB 9 had compatible positive scan, where as incompatible positive findings were 12 and 2 respectively. This study indicates Tc 99 m - MIBI lung scan can be used as a reliable complementary study in diagnosis of APTB and differentiating from

PPARα is a key regulator of hepatic FGF21

International Nuclear Information System (INIS)

Lundasen, Thomas; Hunt, Mary C.; Nilsson, Lisa-Mari; Sanyal, Sabyasachi; Angelin, Bo; Alexson, Stefan E.H.; Rudling, Mats

2007-01-01

The metabolic regulator fibroblast growth factor 21 (FGF21) has antidiabetic properties in animal models of diabetes and obesity. Using quantitative RT-PCR, we here show that the hepatic gene expression of FGF21 is regulated by the peroxisome proliferator-activated receptor alpha (PPARα). Fasting or treatment of mice with the PPARα agonist Wy-14,643 induced FGF21 mRNA by 10-fold and 8-fold, respectively. In contrast, FGF21 mRNA was low in PPARα deficient mice, and fasting or treatment with Wy-14,643 did not induce FGF21. Obese ob/ob mice, known to have increased PPARα levels, displayed 12-fold increased hepatic FGF21 mRNA levels. The potential importance of PPARα for FGF21 expression also in human liver was shown by Wy-14,643 induction of FGF21 mRNA in human primary hepatocytes, and PPARα response elements were identified in both the human and mouse FGF21 promoters. Further studies on the mechanisms of regulation of FGF21 by PPARα in humans will be of great interest

A new role for FBP21 as regulator of Brr2 helicase activity.

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Henning, Lisa M; Santos, Karine F; Sticht, Jana; Jehle, Stefanie; Lee, Chung-Tien; Wittwer, Malte; Urlaub, Henning; Stelzl, Ulrich; Wahl, Markus C; Freund, Christian

2017-07-27

Splicing of eukaryotic pre-mRNA is carried out by the spliceosome, which assembles stepwise on each splicing substrate. This requires the concerted action of snRNPs and non-snRNP accessory proteins, the functions of which are often not well understood. Of special interest are B complex factors that enter the spliceosome prior to catalytic activation and may alter splicing kinetics and splice site selection. One of these proteins is FBP21, for which we identified several spliceosomal binding partners in a yeast-two-hybrid screen, among them the RNA helicase Brr2. Biochemical and biophysical analyses revealed that an intrinsically disordered region of FBP21 binds to an extended surface of the C-terminal Sec63 unit of Brr2. Additional contacts in the C-terminal helicase cassette are required for allosteric inhibition of Brr2 helicase activity. Furthermore, the direct interaction between FBP21 and the U4/U6 di-snRNA was found to reduce the pool of unwound U4/U6 di-snRNA. Our results suggest FBP21 as a novel key player in the regulation of Brr2. © The Author(s) 2017. Published by Oxford University Press on behalf of Nucleic Acids Research.

Cholesterol negatively regulates IL-9-producing CD8+ T cell differentiation and antitumor activity.

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Ma, Xingzhe; Bi, Enguang; Huang, Chunjian; Lu, Yong; Xue, Gang; Guo, Xing; Wang, Aibo; Yang, Maojie; Qian, Jianfei; Dong, Chen; Yi, Qing

2018-05-09

CD8 + T cells can be polarized into IL-9-secreting (Tc9) cells. We previously showed that adoptive therapy using tumor-specific Tc9 cells generated stronger antitumor responses in mouse melanoma than classical Tc1 cells. To understand why Tc9 cells exert stronger antitumor responses, we used gene profiling to compare Tc9 and Tc1 cells. Tc9 cells expressed different levels of cholesterol synthesis and efflux genes and possessed significantly lower cholesterol content than Tc1 cells. Unique to Tc9, but not other CD8 + or CD4 + T cell subsets, manipulating cholesterol content in polarizing Tc9 cells significantly affected IL-9 expression and Tc9 differentiation and antitumor response in vivo. Mechanistic studies showed that IL-9 was indispensable for Tc9 cell persistence and antitumor effects, and cholesterol or its derivatives inhibited IL-9 expression by activating liver X receptors (LXRs), leading to LXR Sumoylation and reduced p65 binding to Il9 promoter. Our study identifies cholesterol as a critical regulator of Tc9 cell differentiation and function. © 2018 Ma et al.

Noninvasive evaluation of active lower gastrointestinal bleeding: comparison between contrast-enhanced MDCT and 99mTc-labeled RBC scintigraphy.

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Zink, Stephen I; Ohki, Stephen K; Stein, Barry; Zambuto, Domenic A; Rosenberg, Ronald J; Choi, Jenny J; Tubbs, Daniel S

2008-10-01

The purpose of our study was to compare contrast-enhanced MDCT and (99m)Tc-labeled RBC scanning for the evaluation of active lower gastrointestinal bleeding. Over 17 months, 55 patients (32 men, 23 women; age range, 21-92 years) were evaluated prospectively with contrast-enhanced MDCT using 100 mL of iopromide 300 mg I/mL. Technetium-99m-labeled RBC scans were obtained on 41 of 55 patients and select patients underwent angiography for attempted embolization. Each imaging technique was reviewed in a blinded fashion for sensitivity for detection of active bleeding as well as the active lower gastrointestinal bleeding location. Findings were positive on both examinations in eight patients and negative on both examinations in 20 patients. Findings were positive on contrast-enhanced MDCT and negative on (99m)Tc-labeled RBC in two patients; findings were negative on contrast-enhanced MDCT and positive on (99m)Tc-labeled RBC in 11 patients. Statistics showed significant disagreement, with simple agreement = 68.3%, kappa = 0.341, and p = 0.014. Sixteen of 60 (26.7%) contrast-enhanced MDCT scans were positive prospectively, with all accurately localizing the site of bleeding and identification of the underlying lesion in eight of 16 (50%). Nineteen of 41 (46.3%) (99m)Tc-labeled RBC scans were positive. Eighteen of 41 matched patients went on to angiography. In four of these 18 (22.2%) patients, the site of bleeding was confirmed by angiography, but in 14 of 18 (77.8%), the findings were negative. Contrast-enhanced MDCT and (99m)Tc-labeled RBC scanning show significant disagreement for evaluation of active lower gastrointestinal bleeding. Contrast-enhanced MDCT appears effective for detection and localization in cases of active lower gastrointestinal bleeding in which hemorrhage is active at the time of CT.

Excitation functions of deuteron induced nuclear reactions on natMo up to 21 MeV. An alternative route for the production of 99mTc and 99Mo

International Nuclear Information System (INIS)

Sonck, M.; Hermanne, A.; Takacs, S.; Szelecsenyi, F.; Tarkanyi, F.

1999-01-01

Cross sections of deuteron induced nuclear reactions on natural molybdenum have been studied in the frame of a systematic investigation of charged particle induced nuclear reactions on metals for different applications. The excitation functions of 92m,95 Nb-, 93,94g,94m,95g,95m,96,99m Tc- and 99 Mo were measured up to 21 MeV deuteron energy by using stacked foil technique and activation method. The goal of this work was to study the production possibility of the medical important 94m,99m Tc- and 99 Mo-nuclides. Production of 99m Tc and 99 Mo is of importance for their use in nuclear medicine, whereas 94m Tc is of interest regarding quantification of kinetics of well-established 99m Tc-radiopharmaceuticals. The production possibilities of 99m Tc and 99 Mo above 20 MeV deuteron energies up to 50 MeV were estimated and was found that beside the proton induced reactions the deuteron induced reactions on enriched molybdenum target are very promising. (author)

Analysis of 99Tc and Its Activity Level in the Korean Soil

International Nuclear Information System (INIS)

Lee, Chang Woo; Chung, Kun Ho; Cho, Young Hyun; Kang, Mun Ja; Lee, Wanno; Kim, Hee Reyoung; Choi, Geun Sik

2009-01-01

An analytical method of 99 Tc concentration in soil was set up and discussed considering the 99 Tc concentration in Korean soil measured with its analytical method. A selective TEVA resin was used to separate and purify 99 Tc the in the soil sample. 99 Tc from a commercial 99 Mo/ 99m Tc generator was used as a yield tracer for the chemical separation of 99 Tc and its problem when using as a tracer was discussed. The chemical recovery yield of was above 70%. The optimum conditions of inductively coupled plasma mass spectrometry system (ICP-MS) were set up to determine the 99 Tc after the separation process. The minimum detectable activity (MDA) was 15 mBq/kg-dry in this analytical procedure. The 99 Tc concentration in soils of Jeju and Kori were measured in the rage of 33.73-89.16 mBq/kg-dry. Those values were less than those reported in other countries and seemed to be originated from atmospheric fallout.

Device-dependent activity estimation and decay correction of radionuclide mixtures with application to Tc-94m PET studies

International Nuclear Information System (INIS)

Smith, Mark F.; Daube-Witherspoon, Margaret E.; Plascjak, Paul S.; Szajek, Lawrence P.; Carson, Richard E.; Everett, James R.; Green, Shielah L.; Territo, Paul R.; Balaban, Robert S.; Bacharach, Stephen L.; Eckelman, William C.

2001-01-01

Multi-instrument activity estimation and decay correction techniques were developed for radionuclide mixtures, motivated by the desire for accurate quantitation of Tc-94m positron emission tomography (PET) studies. Tc-94m and byproduct Tc isotopes were produced by proton irradiation of enriched Mo-94 and natural Mo targets. Mixture activities at the end of bombardment were determined with a calibrated high purity germanium detector. The activity fractions of the greatest mixture impurities relative to 100% for Tc-94m averaged 10.0% (Tc-94g) and 3.3% (Tc-93) for enriched targets and 10.1% (Tc-94g), 11.0% (Tc-95), 255.8% (Tc-96m), and 7.2% (Tc-99m) for natural targets. These radioisotopes have different half-lives (e.g., 52.5 min for Tc-94m, 293 min for Tc-94g), positron branching ratios (e.g., 0.72 for Tc-94m, 0.11 for Tc-94g) and gamma ray emissions for themselves and their short-lived, excited Mo daughters. This complicates estimation of injected activity with a dose calibrator, in vivo activity with PET and blood sample activity with a gamma counter. Decay correction using only the Tc-94m half-life overestimates activity and is inadequate. For this reason analytic formulas for activity estimation and decay correction of radionuclide mixtures were developed. Isotope-dependent sensitivity factors for a PET scanner, dose calibrator, and gamma counter were determined using theoretical sensitivity models and fits of experimental decay curves to sums of exponentials with fixed decay rates. For up to 8 h after the end of bombardment with activity from enriched and natural Mo targets, decay-corrected activities were within 3% of the mean for three PET studies of a uniform cylinder, within 3% of the mean for six dose calibrator decay studies, and within 6% of the mean for four gamma counter decay studies. Activity estimation and decay correction for Tc-94m mixtures enable routine use of Tc-94m in quantitative PET, as illustrated by application to a canine Tc-94m sestamibi

Dual role of miR-21 in CD4+ T-cells: activation-induced miR-21 supports survival of memory T-cells and regulates CCR7 expression in naive T-cells.

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Katarzyna Smigielska-Czepiel

Full Text Available Immune cell-type specific miRNA expression patterns have been described but the detailed role of single miRNAs in the function of T-cells remains largely unknown. We investigated the role of miR-21 in the function of primary human CD4+ T-cells. MiR-21 is substantially expressed in T-cells with a memory phenotype, and is robustly upregulated upon αCD3/CD28 activation of both naive and memory T-cells. By inhibiting the endogenous miR-21 function in activated naive and memory T-cells, we showed that miR-21 regulates fundamentally different aspects of T-cell biology, depending on the differentiation status of the T-cell. Stable inhibition of miR-21 function in activated memory T-cells led to growth disadvantage and apoptosis, indicating that the survival of memory T-cells depends on miR-21 function. In contrast, stable inhibition of miR-21 function in activated naive T-cells did not result in growth disadvantage, but led to a significant induction of CCR7 protein expression. Direct interaction between CCR7 and miR-21 was confirmed in a dual luciferase reporter assay. Our data provide evidence for a dual role of miR-21 in CD4+ T cells; Regulation of T-cell survival is confined to activated memory T-cells, while modulation of potential homing properties, through downregulation of CCR7 protein expression, is observed in activated naive T-cells.

(99m)Tc-HYNIC-TOC scintigraphy in evaluation of active Graves' ophthalmopathy (GO).

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Sun, Hua; Jiang, Xu-Feng; Wang, Shu; Chen, Hao-Yan; Sun, Jiao; Li, Pei-Yong; Ning, Guang; Zhao, Yong-Ju

2007-06-01

A promising radiopharmaceutical (99m)Tc-HYNIC-TOC ((99m)Tc-HYNIC-Octreotide) can be applied for somatostatin receptor scintigraphy with the potential to replace Indium-111 labeled somatostatin analogus. Here we evaluate whether orbital (99m)Tc-HYNIC-TOC scintigraphy can be used as a Graves' ophthalmopathy (GO) activity parameter to predict the retrobulbar irradiation response. Orbital (99m)Tc-HYNIC-TOC scintigraphy was performed on 14 consecutive patients demonstrating moderated to severe Graves' ophthalmopathy. The patients were treated with retrobulbar irradiation following the octreoscan and the response to this therapy was assessed at 3 months after the start of treatment. The orbital (99m)Tc-HYNIC-TOC uptake was calculated to assess the effects of treatment. Among the 14 GO patients, eight (57.1%) responded to retrobulbar radiotherapy; six (42.9%) showed no change. We compared the eight responders and six non-responders in terms of orbital (99m)Tc-HYNIC-TOC uptake, using the orbital/occipital ratio. On the 4-h (99m)Tc-HYNIC-TOC scintigraphy, responders had a higher orbital/occipital uptake ratio than the no-responders (P = 0.001). A significant correlation was found between the orbital/occipital ratio and the clinical activity score (CAS) (P = 0.034). The Receiving-Operator-Characteristic curve showed the best threshold for discriminating active and inactive disease was 1.40 (sensitivity, 100%; specificity, 83.3%). In the responders group, all these eight patients had positive scintigraphy. While there were five patients who had negative scintigraphy in the non-responders group. Orbital (99m)Tc-HYNIC-TOC scintigraphy can be a useful method for the estimation of disease activity and prediction the response to subsequent radiotherapy in GO patient. And the patients with positive octreoscan were more likely to respond to irradiation.

Evaluation of the absorbed dose to the kidneys due to Tc99m (DTPA) / Tc99m (Mag3) and Tc99m (Dmsa)

International Nuclear Information System (INIS)

Vasquez A, M.; Murillo C, F.; Castillo D, C.; Rocha J, J.; Sifuentes D, Y.; Sanchez S, P.; Idrogo C, J.; Marquez P, F.

2015-10-01

The absorbed dose in the kidneys of adult patients has been assessed using the biokinetics of radiopharmaceuticals containing Tc 99m (DTPA) / Tc 99m (Mag3) or Tc 99m (Dmsa).The absorbed dose was calculated using the formalism MIRD and the Cristy-Eckerman representation for the kidneys. The absorbed dose to the kidneys due to Tc 99m (DTPA) / Tc 99m (Mag3), are given by 0.00466 mGy.MBq -1 / 0.00339 mGy.MBq -1 . Approximately 21.2% of the absorbed dose is due to the bladder (content) and the remaining tissue, included in biokinetics of Tc 99m (DTPA) / Tc 99m (Mag3). The absorbed dose to the kidneys due to Tc 99m (Dmsa) is 0.17881 mGy.MBq -1 . Here, 1.7% of the absorbed dose is due to the bladder, spleen, liver and the remaining tissue, included in biokinetics of Tc 99m (Dmsa). (Author)

Effect of milking efficiency on Tc-99 content of Tc-99m derived from Tc-99m generators

International Nuclear Information System (INIS)

Bonnyman, J.

1983-01-01

Tc-99m obtained by separation from its parent Mo-99 always contains Tc-99 produced by decay of Tc-99m and Mo-99. Factors effecting the Tc-99/Tc-99m ratios are discussed. An HPLC method has been developed to measure the 99 TcO 4- content of sodium pertechnetate from generators with a detection limit of 0.9 ng Tc-99 for a 500 μl/ aliquot of TcO 4- -99m. First eluates of 10 chromatograph-ic generators gave Tc-99/Tc-99m ratios ranging from 3.5-46 ng Tc/mCi Tc-99m measured at the time of milking. The measurements indicate that Tc-99/Tc-99m ratios high enough to cause adverse labelling effects could be found in 'instant pertechnetate' and in the first eluate from Tc-99m generators for the activities normally used in radiopharmaceutical production

Tc-99m-MIBI Uptake in Active Pulmonary Tuberculosis: A Case Report

International Nuclear Information System (INIS)

Lee, Chang Ho; Park, Chan Hee; Hwang, Hee Sung; Bae, Moon Sun

1996-01-01

Technetium-99m MIBI was developed as a myocardiac perfusion imagine agent and has been used effectively in the detection and post-therapeutic evaluation of various neoplasm such as thyroid, lung, bone and breast tumors. As an infrequent findings, Tc-99m MIBI agent has shown in non-neoplastic pulmonary conditions including fibroding alveolitis, pulmonary actinomycosis, active pulmonary sarcoidosis, pulmonary interstitial fibrosis in progressive systemic sclerosis and active osteomyelitis. In a recent report conducted by Cetin Oncel, Tc-99m MIBI imaging is an effective method in the detection and follow-up of pulmonary tuberculosis. We have also experienced Tc-99m-MIBI uptake in active pulmonary tuberculosis incidentally found in a patient with suspected proliferative villonodular synovitis of the left ankle.

Comparison of Tc-99m maraciclatide and Tc-99m sestamibi molecular breast imaging in patients with suspected breast cancer.

Science.gov (United States)

O'Connor, Michael K; Morrow, Melissa M B; Hunt, Katie N; Boughey, Judy C; Wahner-Roedler, Dietlind L; Conners, Amy Lynn; Rhodes, Deborah J; Hruska, Carrie B

2017-12-01

Molecular breast imaging (MBI) performed with 99m Tc sestamibi has been shown to be a valuable technique for the detection of breast cancer. Alternative radiotracers such as 99m Tc maraciclatide may offer improved uptake in breast lesions. The purpose of this study was to compare relative performance of 99m Tc sestamibi and 99m Tc maraciclatide in patients with suspected breast cancer, using a high-resolution dedicated gamma camera for MBI. Women with breast lesions suspicious for malignancy were recruited to undergo two MBI examinations-one with 99m Tc sestamibi and one with 99m Tc maraciclatide. A radiologist interpreted MBI studies in a randomized, blinded fashion to assign an assessment score (1-5) and measured lesion size. Lesion-to-background (L/B) ratio was measured with region-of-interest analysis. Among 39 analyzable patients, 21 malignant tumors were identified in 21 patients. Eighteen of 21 tumors (86%) were seen on 99m Tc sestamibi MBI and 19 of 21 (90%) were seen on 99m Tc maraciclatide MBI (p = 1). Tumor extent measured with both radiopharmaceuticals correlated strongly with pathologic size ( 99m Tc sestamibi, r = 0.84; 99m Tc maraciclatide, r = 0.81). The L/B ratio in detected breast cancers was similar for the two radiopharmaceuticals: 1.55 ± 0.36 (mean ± S.D.) for 99m Tc sestamibi and 1.62 ± 0.37 (mean ± S.D.) for 99m Tc maraciclatide (p = 0.53). No correlation was found between the L/B ratio and molecular subtype for 99m Tc sestamibi (r s  = 0.12, p = 0.63) or 99m Tc maraciclatide (r s  = -0.12, p = 0.64). Of 20 benign lesions, 10 (50%) were seen on 99m Tc sestamibi and 9 of 20 (45%) were seen on 99m Tc maraciclatide images (p = 0.1). The average L/B ratio for benign lesions was 1.34 ±0.40 (mean ±S.D.) for 99m Tc sestamibi and 1.41 ±0.52 (mean ±S.D.) for 99m Tc maraciclatide (p = 0.75). Overall diagnostic performance was similar for both radiopharmaceuticals. AUC from ROC

Tc Generator Development: Up-to-Date Tc Recovery Technologies for Increasing the Effectiveness of Mo Utilisation

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Van So Le

2014-01-01

Full Text Available A review on the Mo sources available today and on the Tc generators developed up to date for increasing the effectiveness of Mo utilisation is performed in the format of detailed description of the features and technical performance of the technological groups of the Mo production and Tc recovery. The latest results of the endeavour in this field are also surveyed in regard of the technical solution for overcoming the shortage of Mo supply. The technological topics are grouped and discussed in a way to reflect the similarity in the technological process of each group. The following groups are included in this review which are high specific activity Mo: the current issues of production, the efforts of more effective utilisation, and the high specific activity Mo-based Tc generator and Tc concentration units; low specific activity Mo: the Mo production based on neutron capture and accelerators and the direct production of Tc and the methods of increasing the specific activity of Mo using Szilard-Chalmers reaction and high electric power isotopic separator; up-to-date technologies of Tc recovery from low specific activity Mo: the solvent extraction-based Tc generator, the sublimation methods for Mo/Tc separation, the electrochemical method for Tc recovery, and the column chromatographic methods for Tc recovery. Besides the traditional Tc-generator systems, the integrated Tc generator systems (Tc generator column combined with postelution purification/concentration unit are discussed with the format of process diagram and picture of real generator systems. These systems are the technetium selective sorbent column-based generators, the high Mo-loading capacity column-based integrated Tc generator systems which include the saline-eluted generator systems, and the nonsaline aqueous and organic solvent eluent-eluted generator systems using high Mo-loading capacity molybdategel and recently developed sorbent columns. Tc concentration methods used in the

The Activity of TcCYS4 Modified by Variations in pH and Temperature Can Affect Symptoms of Witches’ Broom Disease of Cocoa, Caused by the Fungus Moniliophthora perniciosa

Science.gov (United States)

Freitas, Ana Camila Oliveira; Souza, Cristiane Ferreira; Monzani, Paulo Sérgio; Garcia, Wanius; de Almeida, Alex Alan Furtado; Costa, Marcio Gilberto Cardoso; Pirovani, Carlos Priminho

2015-01-01

The phytocystatins regulate various physiological processes in plants, including responses to biotic and abiotic stresses, mainly because they act as inhibitors of cysteine proteases. In this study, we have analyzed four cystatins from Theobroma cacao L. previously identified in ESTs libraries of the interaction with the fungus Moniliophthora perniciosa and named TcCYS1, TcCYS2, TcCYS3 and TcCYS4. The recombinant cystatins were purified and subjected to the heat treatment, at different temperatures, and their thermostabilities were monitored using their ability to inhibit papain protease. TcCYS1 was sensitive to temperatures above 50°C, while TcCYS2, TcCYS3, and TcCYS4 were thermostable. TcCYS4 presented a decrease of inhibitory activity when it was treated at temperatures between 60 and 70°C, with the greater decrease occurring at 65°C. Analyses by native gel electrophoresis and size-exclusion chromatography showed that TcCYS4 forms oligomers at temperatures between 60 and 70°C, condition where reduction of inhibitory activity was observed. TcCYS4 oligomers remain stable for up to 20 days after heat treatment and are undone after treatment at 80°C. TcCYS4 presented approximately 90% of inhibitory activity at pH values between 5 and 9. This protein treated at temperatures above 45°C and pH 5 presented reduced inhibitory activity against papain, suggesting that the pH 5 enhances the formation of TcCYS4 oligomers. A variation in the titratable acidity was observed in tissues of T. cacao during the symptoms of witches’ broom disease. Our findings suggest that the oligomerization of TcCYS4, favored by variations in pH, is an endergonic process. We speculate that this process can be involved in the development of the symptoms of witches’ broom disease in cocoa. PMID:25830226

Evaluation of the absorbed dose to the kidneys due to Tc{sup 99m} (DTPA) / Tc{sup 99m} (Mag3) and Tc{sup 99m} (Dmsa); Evaluacion de la dosis absorbida en los rinones debido al Tc{sup 99m} (DTPA) / Tc{sup 99m} (MAG3) y Tc{sup 99m} (DMSA)

Energy Technology Data Exchange (ETDEWEB)

Vasquez A, M.; Murillo C, F.; Castillo D, C.; Rocha J, J.; Sifuentes D, Y.; Sanchez S, P. [Universidad Nacional de Trujillo, Av. Juan Pablo II s/n, Trujillo (Peru); Idrogo C, J.; Marquez P, F., E-mail: marvva@hotmail.com [Instituto Nacional de Enfermedades Neoplasicas, Av. Angamos 2520, Lima (Peru)

2015-10-15

The absorbed dose in the kidneys of adult patients has been assessed using the biokinetics of radiopharmaceuticals containing Tc{sup 99m} (DTPA) / Tc{sup 99m} (Mag3) or Tc{sup 99m} (Dmsa).The absorbed dose was calculated using the formalism MIRD and the Cristy-Eckerman representation for the kidneys. The absorbed dose to the kidneys due to Tc{sup 99m} (DTPA) / Tc{sup 99m} (Mag3), are given by 0.00466 mGy.MBq{sup -1} / 0.00339 mGy.MBq{sup -1}. Approximately 21.2% of the absorbed dose is due to the bladder (content) and the remaining tissue, included in biokinetics of Tc{sup 99m} (DTPA) / Tc{sup 99m} (Mag3). The absorbed dose to the kidneys due to Tc{sup 99m} (Dmsa) is 0.17881 mGy.MBq{sup -1}. Here, 1.7% of the absorbed dose is due to the bladder, spleen, liver and the remaining tissue, included in biokinetics of Tc{sup 99m} (Dmsa). (Author)

Post-translational regulation and trafficking of the granulin-containing protease RD21 of Arabidopsis thaliana.

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Christian Gu

Full Text Available RD21-like proteases are ubiquitous, plant-specific papain-like proteases typified by carrying a C-terminal granulin domain. RD21-like proteases are involved in immunity and associated with senescence and various types of biotic and abiotic stresses. Here, we interrogated Arabidopsis RD21 regulation and trafficking by site-directed mutagenesis, agroinfiltration, western blotting, protease activity profiling and protein degradation. Using an introduced N-glycan sensor, deglycosylation experiments and glyco-engineered N. benthamiana plants, we show that RD21 passes through the Golgi where it becomes fucosylated. Our studies demonstrate that RD21 is regulated at three post-translational levels. Prodomain removal is not blocked in the catalytic Cys mutant, indicating that RD21 is activated by a proteolytic cascade. However, RD21 activation in Arabidopsis does not require vacuolar processing enzymes (VPEs or aleurain-like protease AALP. In contrast, granulin domain removal requires the catalytic Cys and His residues and is therefore autocatalytic. Furthermore, SDS can (re-activate latent RD21 in Arabidopsis leaf extracts, indicating the existence of a third layer of post-translational regulation, possibly mediated by endogenous inhibitors. RD21 causes a dominant protease activity in Arabidopsis leaf extracts, responsible for SDS-induced proteome degradation.

78 FR 7395 - Foreign-Trade Zone 129-Bellingham, WA; Notification of Proposed Production Activity; T.C. Trading...

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2013-02-01

... DEPARTMENT OF COMMERCE Foreign-Trade Zones Board [B-8-2013] Foreign-Trade Zone 129--Bellingham, WA; Notification of Proposed Production Activity; T.C. Trading Company, Inc. (Eyeglass Assembly and Kitting... activity on behalf of T.C. Trading Company, Inc. (T.C. Trading), located in Blaine, Washington. The...

Regulation of miR-21 expression in human melanoma via UV-ray-induced melanin pigmentation.

Science.gov (United States)

Lin, Kuan-Yu; Chen, Chien-Min; Lu, Cheng-You; Cheng, Chun-Yuan; Wu, Yu-Hsin

2017-08-01

Excessive environmental ultraviolet (UV) radiation produces genetic mutations that can lead to skin cancer. This study was designed to assess the potential inhibitory activity of microRNA-21 (miR-21) on the UV irradiation-stimulated melanogenesis signal pathway in melanoma cells. The molecular mechanism of miR-21-induced inhibitory activity on UV-ray-stimulated melanogenesis-regulating proteins was examined in A375.S2 human melanoma and B16F10 mouse melanoma cells. UV irradiation for 30 min induced melanogenesis signal pathway by increasing melanin production and the number of A375.S2 cells. Similarly, UV radiation increased the expression of α-melanocyte-stimulating hormone (α-MSH) protein and decreased the melanogenesis-regulating signal, such as EGFR and Akt phosphorylation. Notably, miR-21 overexpression in UV-ray-stimulated A375.S2 cells decreased α-MSH expression and increased EGFR and Akt phosphorylation levels. Furthermore, miR-21 on UV-ray- induced melanogenesis was down-regulated by the Akt inhibitor and the EGFR inhibitor (Gefitinib). Results suggest that the suppressive activity of miR-21 on UV-ray-stimulated melanogenesis may involve the down-regulation of α-MSH and the activation in both of EGFR and Akt. © 2017 Wiley Periodicals, Inc.

Tumor affinity of technetium-99m labeled radiopharmaceuticals. II. Sup(99m)Tc-Sn-diphosphonate (sup(99m)Tc-EHDP), sup(99m)Tc-Sn-dimercaptosuccinic acid (sup(99m)Tc-DMSA), sup(99m)Tc-Sn-diethyl stilbestrol diphosphate (sup(99m)Tc-DSDP)

Energy Technology Data Exchange (ETDEWEB)

Itoh, K; Kobayashi, S; Hisada, K; Tonami, N [Kanazawa Univ. (Japan). School of Medicine; Ando, A

1976-10-01

The authors have examined the tumor affinity of various sup(99m)Tc-labelled radiopharmaceuticals to Ehrlich's tumor for the purpose of delineating human malignant neoplasm positively. The biologic distributions of sup(99m)Tc-Sn-diphosphonate (sup(99m)Tc-EHDP), sup(99m)Tc-Sn-dimercaptosuccinic acid (sup(99m)Tc-DMSA) and sup(99m)Tc-Sn-diethyl stilbestrol diphosphate (sup(99m)Tc-DSDP, sup(99m)Tc-Honvan) are included as the second report on the tumor affinity of Ehrlich-bearing mice. Tumor concentration of sup(99m)Tc-EHDP was lowest and the positive delineation of implanted tumor with sup(99m)Tc-EHDP was poorest in sequential images, though active accumulation in some soft tissues malignant neoplasms, breast cancer, and thyroid cancer, has been reported. Tumor concentration and the tumor-to-blood ratio of sup(99m)Tc-DMSA were not so high, contrary to our expectation that /sup 197/Hg-DMSA might show high tumor concentration and high tumor-to-blood ratio the same as /sup 197/Hg chlormerodrin of the renal scanning radiopharmaceuticals. Tumor concentration of sup(99m)Tc-DSDP was highest. The tumor-to-blood concentration ratio was lower than that of the above mentioned radiopharmaceuticals but the tumor-to-liver ratio and/or tumor-to-lung ratio was over 1.0 at the earlier time. Biologic distribution of sup(99m)Tc-DSDP was similar to that of /sup 32/P labeled DSDP. It is presumed that sup(99m)Tc is labeled at the phosphate ester of DSDP which is dephospholytated immediately by phospholylase in vivo following intravenous injection. Although it is not known precisely it may be assumed that the mechanism of accumulating sup(99m)Tc-DSDP in Ehrlich's tumor is related to the phospholylase activity in neoplasms.

The sorption behaviour of 99Tc on activated carbon

International Nuclear Information System (INIS)

Xia Deying; Zeng Jishu

2004-01-01

The sorption behaviour of 99 Tc on apricot-pit activated carbon with batch experiment is studied. The influence of such factors as sorbent particle size, temperature, pH value on sorption ratio, and the Freundlich sorption isotherms are reported in this paper. (author)

Comparison of sup(99m)Tc-MDP to sup(99m)Tc-pertechnetate by computerized quantitative joint scintigraphy

International Nuclear Information System (INIS)

Rekonen, A.; Moettoenen, T.; Oka, M.

1982-01-01

99mTc-pertechnetate was compared to 99mTc-MDP in joint pairs with asymmetric arthritis. Markedly elevated joint activity ratios (inflamed/uninflamed joint) were measured in all the joint pairs studied. In the joints affected by reactive arthritis and without roentgenologic changes the mean joint activity was the same with both tracers. A very high activity ratio with 99mTc-MDP was found in septic arthritis. In rheumatoid arthritis the sensitivity of 99mTc-MDP as an indicator of active arthritis seemed to be better than that of 99mTc-pertechnetate. Even in joints without erosions in roentgenograms the joint activity ratios were markedly elevated with 99mTc-MDP. This suggests, that high activity in 99mTc-MDP scanning might be prognostic of erosive joint changes. In this work a profile curve was used for quantitation differences between joints

Development of 99Mo/99mTc Generator System for Production of Medical Radionuclide 99mTc using a Neutron-activated 99Mo and Zirconium Based Material (ZBM as its Adsorbent

Directory of Open Access Journals (Sweden)

I. Saptiama

2016-12-01

Full Text Available Molybdenum produced from fission of U-235 is the most desirable precursor for 99Mo/99mTc generator system as it is non-carrier added and has high specific activity. However, in the last decade there has been short supply of 99Mo due to several constrains. Therefore, there have been many works performed for development of 99Mo/99mTc generator system using 99Mo which is not produced from either LEU or HEU. This report deals with development of 99Mo/99mTc generator system where zirconium-based material (ZBM is used as adsorbent of neutron-activated 99Mo. The system was prepared by firstly irradiating natural Mo in the G. A. Siwabessy reactor to produce neutron-activated 99Mo. The target was dissolved in NaOH 4N and then neutralized with 12 M HCl. The 99Mo solution was then mixed with a certain amount of ZBM followed by heating at 90°C for three hours to allow the 99Mo adsorbed on ZBM. The 99Mo-ZBM (9.36 GBq of 99Mo was Mo/ 4.2 g ZBM was packed on a fritz-glass column. This column was then fitted serially with an alumina column for trapping 99Mo breakthrough. The columns were then eluted daily with saline solution for up to one week. The yield of 99mTc was found to be between 53.7 – 74% (n= 5. All 99mTc eluates were clear solutions with pH of 5. Breakthrough of 99Mo in 99mTc eluates was found to be 0.031 ± 0.019 μCi 99Mo/ mCi 99mTc (n= 5 which was less than the maximum activity of 99Mo allowed in 99mTc solution ( 99%. Radiolabeling of this 99mTc towards methylene diphosphonate (MDP kit gave a radiolabelling efficiency of 99%. In summary, a new 99Mo/99mTc generator system that used neutron-activated 99Mo and ZBM as its adsorbent has been successfully prepared. The 99mTc produced from this new 99Mo/99mTc generator system attained the quality of 99mTc required for medical purposes.

Synthesis, Characterization, and Preclinical Evaluation of (99m)Tc-Labeled Macrobicyclic and Tricyclic Chelators as Single Photon Emission Computed Tomography Tracer.

Science.gov (United States)

Yadav, Neelam; Chuttani, Krishna; Mishra, Anil K; Singh, Bachcha

2016-05-01

The novel tetraaza macrobicyclic chelator 3,6,9,15-tetraazabicyclo[9.3.1]pentadeca-1(15),11,13-triene-2,10-dione (TBPD) and pentaaza macrotricyclic chelator 9-oxa-3,6,12,15,21-pentaazatricyclo[15,3,2,1]trieicos-1(21),17,19-triene-2,7,11,16-tetradione (OPTT) were synthesized, characterized, and radiolabeled with (99m)Tc to produce (99m)Tc-TBPD and (99m)Tc-OPTT. These radiolabeled complexes were prepared with high radiolabeling yield, radiochemical purity, and good in vitro stability up to 24 h. The labeling efficiency of (99m)Tc-TBPD and (99m)Tc-OPTT was found 98% and 97%. In vitro serum stability of (99m)Tc-TBPD was found to be 95.2%, while that of (99m)Tc-OPTT 94.2% up to 24 h. Blood kinetics experiments of (99m)Tc-labeled complexes showed biphasic pattern of blood clearance. About 99.57 ± 0.89% activity of (99m)Tc-TBPD and 99.42 ± 0.88% activity of (9m)Tc-OPTT were cleared off blood stream at 24 h postadministration. The biological half-life of (99m) Tc-TBPD was observed: t1/2(F) 1 h 5 min and t1/2(S) 12 h and biological half-life of (99m)Tc-OPTT was observed: t1/2(F) 1 h 10 min and t1/2(S) 9 h 50 min, respectively. The biodistribution studies revealed that maximum uptake of (99m)Tc-TBPD was found in liver, concluded that excretory pathway is hepatobiliary, while that of (99m)Tc-OPTT was renal as well as hepatobiliary. The negligible activity observed in stomach confirming the stability of radiolabeled complex in biological milieu. In vitro cytotoxicity study of TBPD and OPTT did not show any considerable antiproliferative activity against cancer cells of human cervical SW756, HeLa, and glioblastoma U-87, U373 cell lines. © 2015 John Wiley & Sons A/S.

Tc-MYBPA an Arabidopsis TT2-like transcription factor and functions in the regulation of proanthocyanidin synthesis in Theobroma cacao.

Science.gov (United States)

Liu, Yi; Shi, Zi; Maximova, Siela N; Payne, Mark J; Guiltinan, Mark J

2015-06-25

The flavan-3-ols catechin and epicatechin, and their polymerized oligomers, the proanthocyanidins (PAs, also called condensed tannins), accumulate to levels of up to 15 % of the total weight of dry seeds of Theobroma cacao L. These compounds have been associated with several health benefits in humans. They also play important roles in pest and disease defense throughout the plant. In Arabidopsis, the R2R3 type MYB transcription factor TT2 regulates the major genes leading to the synthesis of PA. To explore the transcriptional regulation of the PA synthesis pathway in cacao, we isolated and characterized an R2R3 type MYB transcription factor MYBPA from cacao. We examined the spatial and temporal gene expression patterns of the Tc-MYBPA gene and found it to be developmentally expressed in a manner consistent with its involvement in PAs and anthocyanin synthesis. Functional complementation of an Arabidopsis tt2 mutant with Tc-MYBPA suggested that it can functionally substitute the Arabidopsis TT2 gene. Interestingly, in addition to PA accumulation in seeds of the Tc-MYBPA expressing plants, we also observed an obvious increase of anthocyanidin accumulation in hypocotyls. We observed that overexpression of the Tc-MYBPA gene resulted in increased expression of several key genes encoding the major structural enzymes of the PA and anthocyanidin pathway, including DFR (dihydroflavanol reductase), LDOX (leucoanthocyanidin dioxygenase) and BAN (ANR, anthocyanidin reductase). We conclude that the Tc-MYBPA gene that encodes an R2R3 type MYB transcription factor is an Arabidopsis TT2 like transcription factor, and may be involved in the regulation of both anthocyanin and PA synthesis in cacao. This research may provide molecular tools for breeding of cacao varieties with improved disease resistance and enhanced flavonoid profiles for nutritional and pharmaceutical applications.

The g.-165 T>C Rather than Methylation Is Associated with Semen Motility in Chinese Holstein Bulls by Regulating the Transcriptional Activity of the HIBADH Gene.

Directory of Open Access Journals (Sweden)

Shuai Zhang

Full Text Available The 3-hydroxyisobutyrate dehydrogenase (HIBADH is regarded as a human sperm-motility marker. However, the molecular mechanisms involved in the regulation of expression of the HIBADH gene in bulls remain largely unknown. HIBADH was detected in the testis, epididymis, and sperm via reverse transcription polymerase chain reaction and Western blot analysis. It is also expressed in the seminiferous epithelium, spermatids, and the entire epididymis, as detected by immunohistochemistry. Furthermore, HIBADH was expressed in the neck-piece and mid-piece of bull spermatids, as shown in the immunofluorescence assay. Using serially truncated bovine HIBADH promoters and luciferase constructs, we discovered an 878 bp (-703 bp to +175 bp fragment that constitutes the core promoter region. One SNP g.-165 T>C of HIBADH was identified and genotyped in 307 Chinese Holstein bulls. Correlation analysis revealed that bulls with the TT genotype had higher initial sperm motility than those with the CC genotype (P C rather than methylation in the 5'-flanking region could affect the bovine sperm motility through the regulation of HIBADH gene transcriptional activity.

Clinical evaluation of hepatic scintigraphy using 99mTc-GSA

International Nuclear Information System (INIS)

Ishii, Katsumi; Nishiyama, Shogo; Nishimaki, Hiroshi; Tadokoro, Katsumi; Ikeda, Toshiaki; Matsubayashi, Takashi; Ishii, Kodo

1992-01-01

Functional hepatic imaging was performed using 99m Tc-DTPA-galactosyl human serum albumin ( 99m Tc-GSA), a radiolabeled ligand that reacts specifically to the asialoglycoprotein receptor that resides at the plasma membrane of hepatocytes, in 21 patients: five with chronic active hepatitis (CAH), 14 with compensative liver cirrhosis (LC), one with chronic inactive hepatitis and one with acute hepatitis. The former two diseases were mainly investigated. Serial liver images were acquired at the rates of 10 sec/frame for 0-5 min and 2 min/frame for 6-30 min after the injection of 99m Tc-GSA, and the images were compared with 99m Tc-phytase images in 2 patients with CAH and 11 with LC, and those with portal scintigrams using 123 I-iodoamphetamine (IMP) in 3 patients with LC. The images using 99m Tc-GSA were in better agreement with hepatic function than those using 99m Tc-phytase, and with the findings of portal scintigraphy using 123 I-IMP. LHL15 (liver/liver and heart radioactivities at 15 min after injection of 99m Tc-GSA) correlated with the hepaplastin test (r=0.978 in CAH, and r=0.544 in LC), indicators of hepatic reserve. These results suggest that liver scintigraphy using 99m Tc-GSA might be a useful method for evaluating liver function. (author)

Pulsed Electromagnetic Field Regulates MicroRNA 21 Expression to Activate TGF-β Signaling in Human Bone Marrow Stromal Cells to Enhance Osteoblast Differentiation

Directory of Open Access Journals (Sweden)

Nagarajan Selvamurugan

2017-01-01

Full Text Available Pulsed electromagnetic fields (PEMFs have been documented to promote bone fracture healing in nonunions and increase lumbar spinal fusion rates. However, the molecular mechanisms by which PEMF stimulates differentiation of human bone marrow stromal cells (hBMSCs into osteoblasts are not well understood. In this study the PEMF effects on hBMSCs were studied by microarray analysis. PEMF stimulation of hBMSCs’ cell numbers mainly affected genes of cell cycle regulation, cell structure, and growth receptors or kinase pathways. In the differentiation and mineralization stages, PEMF regulated preosteoblast gene expression and notably, the transforming growth factor-beta (TGF-β signaling pathway and microRNA 21 (miR21 were most highly regulated. PEMF stimulated activation of Smad2 and miR21-5p expression in differentiated osteoblasts, and TGF-β signaling was essential for PEMF stimulation of alkaline phosphatase mRNA expression. Smad7, an antagonist of the TGF-β signaling pathway, was found to be miR21-5p’s putative target gene and PEMF caused a decrease in Smad7 expression. Expression of Runx2 was increased by PEMF treatment and the miR21-5p inhibitor prevented the PEMF stimulation of Runx2 expression in differentiating cells. Thus, PEMF could mediate its effects on bone metabolism by activation of the TGF-β signaling pathway and stimulation of expression of miR21-5p in hBMSCs.

Standardization of Tc-99 by two methods and participation at the CCRI(II)-K2. Tc-99 comparison.

Science.gov (United States)

Sahagia, M; Antohe, A; Ioan, R; Luca, A; Ivan, C

2014-05-01

The work accomplished within the participation at the 2012 key comparison of Tc-99 is presented. The solution was standardized for the first time in IFIN-HH by two methods: LSC-TDCR and 4π(PC)β-γ efficiency tracer. The methods are described and the results are compared. For the LSC-TDCR method, the program TDCR07c, written and provided by P. Cassette, was used for processing the measurement data. The results are 2.1% higher than when applying the TDCR06b program; the higher value, calculated with the software TDCR07c, was used for reporting the final result in the comparison. The tracer used for the 4π(PC)β-γ efficiency tracer method was a standard (60)Co solution. The sources were prepared from the mixture (60)Co+(99)Tc solution and a general extrapolation curve, type: N(βTc-99)/(M)(Tc-99)=f [1-ε(Co-60)], was drawn. This value was not used for the final result of the comparison. The difference between the values of activity concentration obtained by the two methods was within the limit of the combined standard uncertainty of the difference of these two results. © 2013 Published by Elsevier Ltd.

78 FR 30269 - Foreign-Trade Zone 129-Bellingham, Washington; Authorization of Production Activity; T.C. Trading...

Science.gov (United States)

2013-05-22

... proposed production activity to the Foreign-Trade Zones (FTZ) Board on behalf of T.C. Trading Company, Inc... DEPARTMENT OF COMMERCE Foreign-Trade Zones Board [B-8-2013] Foreign-Trade Zone 129--Bellingham, Washington; Authorization of Production Activity; T.C. Trading Company, Inc. (Eyeglass Assembly and Kitting...

Preparation and biological evaluation of cyclopentadienyl-based 99mTc-complexes [(Cp-R)99mTc(CO)3] mimicking benzamides for malignant melanoma targeting

International Nuclear Information System (INIS)

Peindy N'Dongo, Harmel W.; Raposinho, Paula D.; Fernandes, Celia; Santos, Isabel; Can, Daniel; Schmutz, Paul; Spingler, Bernhard; Alberto, Roger

2010-01-01

The biological evaluation of half-sandwich 99m Tc-complexes that surrogate iodobenzamide with a high affinity for melanin tumor tissue is described. We have synthesized via retro Diels-Alder reaction two models of 99m Tc complexes which possess the piano stool [Cp 99m Tc(CO) 3 ] motif instead of a phenyl ring as in the original iodobenzamide 123 I-N-(N-benzylpiperidin-4-yl)-2-iodobenzamide (2-IBP) and N-(2-diethylaminoethyl)-4-iodobenzamide (BZA). Diels-Alder products - (HCp-CONHR) 2 (, R=2-diethylaminoethyl; , R=benzylpiperidin-4-yl) were prepared and reacted with fac-[ 99m Tc(H 2 O) 3 (CO) 3 )] + 1 in water to produce the corresponding 99m Tc complexes [() 99m Tc(CO) 3 )] and [() 99m Tc(CO) 3 )] . The structures of the 99m Tc complexes on the no-carrier-added level have been confirmed by chromatographic comparison with the corresponding rhenium complexes and , macroscopically characterized by IR, NMR, ESI-MS and X-ray crystallography for [triclinic, P-1, a=7.3518(1) A, b=8.0309(2) A, c=17.5536(3) A, α=99.1260(5) o , β=90.4215(14) o , γ=117.0187(11) o ]. The radioconjugate showed good in vitro stability. In murine melanoma B16F1 cells, significant cellular uptake (43.9% of the total applied activity) was attained after 4 h at 37 deg. C with about 50% of the cell-associated radioactivity being internalized in the cells (22% of the applied activity). Furthermore, in melanoma-bearing C57BL6 mice, tumor uptake values of 3.39±0.50 %ID g -1 and 3.21±0.26 %ID g -1 at 1 and 4 h postinjection, respectively, were observed indicating a good retention of in the tumor.

Use of 99mTc-bicisate in activation studies by split-dose technique

DEFF Research Database (Denmark)

Holm, S; Madsen, P L; Sperling, B

1994-01-01

The properties of the brain single photon emission computed tomography (SPECT) tracer 99mTc-bicisate (ethyl cysteinate dimer) were examined in regard to its use in test-retest studies with short-interval, split-dose studies. The stimulus applied in these tests was a visual activation by a "flicke......The properties of the brain single photon emission computed tomography (SPECT) tracer 99mTc-bicisate (ethyl cysteinate dimer) were examined in regard to its use in test-retest studies with short-interval, split-dose studies. The stimulus applied in these tests was a visual activation...

Interleukin-21 gene polymorphism rs2221903 is associated with disease activity in patients with rheumatoid arthritis.

Science.gov (United States)

Malinowski, Damian; Paradowska-Gorycka, Agnieszka; Safranow, Krzysztof; Pawlik, Andrzej

2017-08-01

Interleukin-21 (IL-21) is a cytokine which plays a significant role in the pathogenesis and disease activity of rheumatoid arthritis (RA). Genetic polymorphisms in the IL-21 gene may alter the synthesis of IL-21. The aim of this study was to examine IL-21 and IL-21R polymorphisms in patients with RA. We examined 422 patients with RA and 338 healthy controls. Single nucleotide polymorphisms (SNPs) within the IL-21 (rs6822844 G>T, rs6840978 C>T, rs2221903 T>C) and IL-21R (rs2285452 G>A) genes were genotyped using TaqMan genotyping assays. There were no statistically significant differences in the distribution of studied genotypes and alleles between RA patients and the control group. To examine whether IL-21 polymorphisms affect disease activity in RA patients, we compared the distribution of IL-21 genotypes between patients with DAS28 ≤ 2.5 (patients with remission of disease symptoms) and patients with DAS28 > 2.5 (patients with active RA). Among patients with DAS28 > 2.5, increased prevalence of rs2221903 CT and CC genotypes was observed (OR = 1.54; 95% CI: 1.04-2.28; p = 0.035). The results of this study suggest that IL-21 and IL-21R gene polymorphisms are not risk loci for RA susceptibility, whereas the IL-21 rs2221903 polymorphism is associated with disease activity.

Determination of Tc-99 in radioactive wastes; Determinacion de Tc-99 en desechos radiactivos

Energy Technology Data Exchange (ETDEWEB)

Rivera S, A. A.

2015-07-01

Tc-99 is a fission product and one of the most important radionuclides from the view point of safety assessment for the disposal of radioactive waste because of its long half-life (2.1 x 10{sup 5} years) and high mobility in soil-water systems, if this is released into the environment in significant quantities can concentrate on plants and animals. Tc-99 is a pure beta emitter with a maximum energy of 292 KeV, so their quantification imposes destructive methods to be analyzed by liquid scintillation. Therefore the quantification of Tc-99 in ion exchange resins requires of the mineralization of these and separation of Tc-99 of other radioisotopes present in the resin. Therefore the object of this thesis is to develop a quantification method of Tc-99 content in spent exchange resins. So in order to track the behavior of technetium during digestion exchange resins and radiochemical separation, given its high volatility, in this work the {sup 99m}Tc is used. To determine the degree of mineralization of the resins, an analysis was performed by chromatography. Subsequently the method used to determine the percentage of {sup 99m}Tc aerosolized during mineralization of resin is described. After the method for the radiochemical separation of {sup 99m}Tc is presented by liquid-liquid extraction using crown ether as extractant; for this testing was performed by varying the molarity of the extractant, the ratio of solvent extractant, type of digestion of the resin and the presence of Sr-85, in order to study the behavior of {sup 99m}Tc in the presence of this radioisotope. Finally, a track beta spectra of a sample of {sup 99m}Tc eluted from a generator {sup 99}Mo/{sup 99m}Tc function of time was performed. (Author)

31 CFR 358.21 - Can these regulations be amended?

Science.gov (United States)

2010-07-01

... 31 Money and Finance: Treasury 2 2010-07-01 2010-07-01 false Can these regulations be amended? 358.21 Section 358.21 Money and Finance: Treasury Regulations Relating to Money and Finance (Continued... CONVERSION OF BEARER CORPORA AND DETACHED BEARER COUPONS § 358.21 Can these regulations be amended? We may at...

Paradoxical Regulation of Human FGF21 by Both Fasting and Feeding Signals: Is FGF21 a Nutritional Adaptation Factor?

Science.gov (United States)

Uebanso, Takashi; Taketani, Yutaka; Yamamoto, Hironori; Amo, Kikuko; Ominami, Hirokazu; Arai, Hidekazu; Takei, Yuichiro; Masuda, Masashi; Tanimura, Ayako; Harada, Nagakatsu; Yamanaka-Okumura, Hisami; Takeda, Eiji

2011-01-01

Fibroblast growth factor 21 (FGF21) has recently emerged as a metabolic hormone involved in regulating glucose and lipid metabolism in mouse, but the regulatory mechanisms and actions of FGF21 in humans remain unclear. Here we have investigated the regulatory mechanisms of the human FGF21 gene at the transcriptional level. A deletion study of the human FGF21 promoter (−1672 to +230 bp) revealed two fasting signals, including peroxisome proliferator-activated receptor α (PPARα) and glucagon signals, that independently induced human FGF21 gene transcription in mouse primary hepatocytes. In addition, two feeding signals, glucose and xylitol, also dose-dependently induced human FGF21 gene transcription and mRNA expression in both human HepG2 cells and mouse primary hepatocytes. FGF21 protein expression and secretion were also induced by high glucose stimulation. The human FGF21 promoter (−1672 to +230 bp) was found to have a carbohydrate-responsive element at −380 to −366 bp, which is distinct from the PPAR response element (PPRE). Knock-down of the carbohydrate response element binding protein by RNAi diminished glucose-induced human FGF21 transcription. Moreover, we found that a region from −555 to −443 bp of the human FGF21 promoter region exerts an important role in the activation of basic transcription. In conclusion, human FGF21 gene expression is paradoxically and independently regulated by both fasting and feeding signals. These regulatory mechanisms suggest that human FGF21 is increased with nutritional crisis, including starvation and overfeeding. PMID:21829679

99mTc labeled VIP analog: evaluation for imaging colorectal cancer

International Nuclear Information System (INIS)

Rao, P.S.; Thakur, M.L.; Pallela, V.; Patti, R.; Reddy, K.; Li, H.; Sharma, S.; Pham, H.L.; Diggles, L.; Minami, C.; Marcus, C.S.

2001-01-01

Early and reliable diagnosis of colorectal cancer continues to be demanding and challenging. Colorectal cancer cells express Vasoactive Intestinal Peptide (VIP) receptors in high density. We have prepared a VIP analog (TP3654), labeled it with 99m Tc, and evaluated it in experimental animals as an agent for imaging colorectal cancer. The tissue distribution of 99m Tc-TP3654 has been compared with that of 111 In-DTPA-Octreotide and 99m Tc-anti-CEA scan in nude mice bearing human colorectal cancer LS174T. Finally, pharmacokinetic and tissue distribution studies of 99m Tc-TP3654 have been performed in four normal human volunteers. Data suggest that 99m Tc-TP3654 can be prepared efficiently without loss of its receptor specificity and biological activity. Although the 24 hr tumor uptake of 99m Tc-TP3654 in the animal model used was modest (0.21 ± 0.07% I.D./g), the tissue distribution profile was more favorable than that of 111 In-DTPA-Octreotide or 99m Tc-anti-CEA scan. Human studies indicated that 99m Tc-TP3654 had no adverse effect in any subject. Within 24 hours, approximately 70% of the injected dose cleared through the kidneys, and approximately 20% through the hepatobiliary system. In these non-fasting volunteers hepatobiliary clearance was slow and in cancer patients tumor uptake was rapid. Data suggest that 99m Tc-TP3654 is a promising agent for imaging colorectal cancer

In vitro assessment of Tc-99m labeled bovine thrombin and streptokinase-activated human plasmin: concise communication

International Nuclear Information System (INIS)

Wong, D.W.; Tanaka, T.; Mishkin, F.; Lee, T.

1979-01-01

Bovine thrombin and streptokinase-activated human plasmin have been labeled with Tc-99m using stannous reduction of pertechnetate under physiological conditions (pH 7.4). The binding efficiency of radiotechnetium to these enzymes is greater than 94%, with less than 5% of reduced but unbound Tc-99m (Sn) complex as assayed by ascending paper radiochromatography using ITLC silica gel plate. Free or unbound pertechnetate is less than 1%. In vitro enzymatic analyses of the Tc-99m-labeled enzymes demonstrate no evidence of protein denaturation or significant loss of enzymatic activity after labeling. Both labeled enzymes are biochemically active in vitro with their respective substrates

labeling of some organic compounds of expected biological activity with Tc-99m eluted from a chromatographic column packed with zirconium molybdate containing mo-99

International Nuclear Information System (INIS)

Abd Elaal, M.A.A.

2011-01-01

characterized using different analytical techniques like elemental analysis, IR, 1 H-NMR and mass spectroscopy.The synthesized iminodiacetic acid derivatives (NIDA, DMIDA and BPIDA) were labeled with 99m Tc and the optimum conditions used to prepare the 99m Tc-NIDA, 99m Tc-DMIDA and 99m Tc-BPIDA can be summarized as follow:NIDA: 30 mg NIDA + 0.3 mg SnCl 2 .2H 2 O at ph 6 after 15 min, it gives 94. 2±2% labeling yield with 99m Tc showing stability up to 6 h.DMIDA: 3 mg DMIDA + 30μg SnCl 2 .2H 2 O at ph 6 after 15 min, it gives 93.1±2% labeling yield with 99m Tc showing stability up to 6 h.BPIDA: 2 mg BPIDA in the presence of 20μg SnCl 2 .2H 2 O at ph 6 after 15 min, it gives 85.4 ±3% labeling yield with 99m Tc showing stability up to 6 h.Biodistribution studies of 99m Tc-NIDA, 99m Tc-DMIDA and 99m Tc-BPIDA in mice showed that most of the injected activity was transported to the liver and cleared into the gallbladder and intestine with a minimal uptake in the other organs, a high degree of liver uptake and fast clearance where the activity in the liver was 19.23%, 25.17% and 18.63% after 10 min post injection, respectively, and cleared rapidly till reaching 3.31%, 7.21% and 5.2% after 3 h, respectively. The accumulation of the activity in the stomach was low, 0.47%, 0.28% and 1.07% after 60 min post injection indicating that 99m Tc-NIDA, 99m Tc-DMIDA and 99m Tc-BPIDA complex remains stable without any decomposition inside the body.

Clinical evaluation of hepatic scintigraphy using sup 99m Tc-GSA

Energy Technology Data Exchange (ETDEWEB)

Ishii, Katsumi; Nishiyama, Shogo; Nishimaki, Hiroshi; Tadokoro, Katsumi; Ikeda, Toshiaki; Matsubayashi, Takashi; Ishii, Kodo (Kitasato Univ., Sagamihara, Kanagawa (Japan). School of Medicine)

1992-06-01

Functional hepatic imaging was performed using {sup 99m}Tc-DTPA-galactosyl human serum albumin ({sup 99m}Tc-GSA), a radiolabeled ligand that reacts specifically to the asialoglycoprotein receptor that resides at the plasma membrane of hepatocytes, in 21 patients: five with chronic active hepatitis (CAH), 14 with compensative liver cirrhosis (LC), one with chronic inactive hepatitis and one with acute hepatitis. The former two diseases were mainly investigated. Serial liver images were acquired at the rates of 10 sec/frame for 0-5 min and 2 min/frame for 6-30 min after the injection of {sup 99m}Tc-GSA, and the images were compared with {sup 99m}Tc-phytase images in 2 patients with CAH and 11 with LC, and those with portal scintigrams using {sup 123}I-iodoamphetamine (IMP) in 3 patients with LC. The images using {sup 99m}Tc-GSA were in better agreement with hepatic function than those using {sup 99m}Tc-phytase, and with the findings of portal scintigraphy using {sup 123}I-IMP. LHL15 (liver/liver and heart radioactivities at 15 min after injection of {sup 99m}Tc-GSA) correlated with the hepaplastin test (r=0.978 in CAH, and r=0.544 in LC), indicators of hepatic reserve. These results suggest that liver scintigraphy using {sup 99m}Tc-GSA might be a useful method for evaluating liver function. (author).

Quantifying Tc-99 contamination in a fuel fabrication plant - 59024

International Nuclear Information System (INIS)

Darbyshire, Carol; Burgess, Pete

2012-01-01

The Springfields facility manufactures nuclear fuel products for the UK's nuclear power stations and for international customers. Fuel manufacture is scheduled to continue into the future. In addition to fuel manufacture, Springfields is also undertaking decommissioning activities. Today it is run and operated by Springfields Fuels Limited, under the management of Westinghouse Electric UK Limited. The site has been operating since 1946 manufacturing nuclear fuel. As part of the decommissioning activities, there was a need was to quantify contamination in a large redundant building. This building had been used to process uranium derived from uranium ore concentrate but had also processed a limited quantity of recycled uranium. The major non-uranic contaminant was Tc-99. The aim was to be able to identify any areas where the bulk activity exceeded 0.4 Bq/g Tc-99 as this would preclude the demolition rubble being sent to the local disposal facility. The problems associated with this project were the presence of significant uranium contamination, the realisation that both the Tc-99 and the uranium had diffused into the brickwork to a significant depth and the relatively low beta energy of Tc-99. The uranium was accompanied by Pa-234m, an energetic beta emitter. The concentration/depth profile was determined for several areas on the plant for Tc-99 and for uranium. The radiochemical analysis was performed locally but the performance of the local laboratory was checked during the initial investigation by splitting samples three ways and having confirmation analyses performed by 2 other laboratories. The results showed surprisingly consistent concentration gradients for Tc-99 and for uranium across the samples. Using that information, the instrument response was calculated for Tc-99 using the observed diffusion gradient and averaged through the full 225 mm of brick wall, as agreed by the regulator. The Tc-99 and uranium contributions to the detector signal were separated

Development of full sweet, umami, and bitter taste responsiveness requires Regulator of G protein Signaling-21 (RGS21).

Science.gov (United States)

Schroer, Adam B; Gross, Joshua D; Kaski, Shane W; Wix, Kim; Siderovski, David P; Vandenbeuch, Aurelie; Setola, Vincent

2018-04-26

The mammalian tastes of sweet, umami, and bitter are initiated by activation of G protein-coupled receptors (GPCRs) of the T1R and T2R families on taste receptor cells. GPCRs signal via nucleotide exchange and hydrolysis, the latter hastened by GTPase-accelerating proteins (GAPs) that include the Regulators of G protein Signaling (RGS) protein family. We previously reported that RGS21, uniquely expressed in Type II taste receptor cells, decreases the potency of bitter-stimulated T2R signaling in cultured cells, consistent with its in vitro GAP activity. However, the role of RGS21 in organismal responses to GPCR-mediated tastants was not established. Here, we characterized mice lacking the Rgs21 fifth exon. Eliminating Rgs21 expression had no effect on body mass accumulation (a measure of alimentation), fungiform papillae number and morphology, circumvallate papillae morphology, and taste bud number. Two-bottle preference tests, however, revealed that Rgs21-null mice have blunted aversion to quinine and denatonium, and blunted preference for monosodium glutamate, the sweeteners sucrose and SC45647, and (surprisingly) NaCl. Observed reductions in GPCR-mediated tastant responses upon Rgs21 loss are opposite to original expectations, given that loss of RGS21 -- a GPCR signaling negative regulator -- should lead to increased responsiveness to tastant-mediated GPCR signaling (all else being equal). Yet, reduced organismal tastant responses are consistent with observations of reduced chorda tympani nerve recordings in Rgs21-null mice. Reduced tastant-mediated responses and behaviors exhibited by adult mice lacking Rgs21 expression since birth have thus revealed an underappreciated requirement for a GPCR GAP to establish the full character of tastant signaling.

99mTc-rituximab radiolabelled by photo-activation: a new non-Hodgkin's lymphoma imaging agent

International Nuclear Information System (INIS)

Gmeiner Stopar, T.; Fettich, J.; Hojker, S.; Mlinaric-Rascan, I.; Mather, S.J.

2006-01-01

Rituximab was the first chimeric monoclonal antibody to be approved for treatment of indolent B-cell non-Hodgkin's lymphoma (NHL). It is directed against the CD20 antigen, which is expressed by 95% of B-cell NHLs. The aim of this study was to explore the possibility of radiolabelling rituximab with 99m Tc for use as an imaging agent in NHL for early detection, staging, remission assessment, monitoring for metastatic spread and tumour recurrence, and assessment of CD20 expression prior to (radio)immunotherapy. Rituximab was purified from Mabthera solution (Roche), photo-activated at 302 nm by UV irradiation and radiolabelled with 99m Tc. The effectiveness of the labelling method was evaluated by determination of the number of free thiol groups per photoreduced antibody, radiochemical purity and in vitro stability of 99m Tc-rituximab. On average, 4.4 free thiol groups per photoreduced antibody were determined. Radiolabelling yields greater than 95% were routinely observed after storage of the photo-activated antibody at -80 C for 195 days. The direct binding assay showed preserved ability of 99m Tc-rituximab to bind to CD20, with an average immunoreactive fraction of 93.3%. The internalisation rate was proven to be low, with only 5.3% of bound 99m Tc-rituximab being internalised over 4 h at 37 C. Our results demonstrate that 99m Tc-rituximab of high radiochemical purity and with preserved binding affinity for the antigen can be prepared by photoreduction and that the method shows good reproducibility. 99m Tc-rituximab will be further explored as an imaging agent applicable in NHL for the purposes mentioned above. (orig.)

Use of 99mTc from a commercial 99Mo/9mTc generator as yield tracer for the determination of 99Tc at low levels

DEFF Research Database (Denmark)

Hou, Xiaolin; Jensen, Mikael; Nielsen, Sven Poul

2007-01-01

The concentrations of Tc-99 and impurity radionuclides in the Tc-99m tracer solution obtained from a commercial Mo-99/Tc-99m generator were measured by gamma spectrometry and liquid scintillation counting. Mo-99 and Ru-103 were found in the Tc-99m eluate. A simple separation using two extra alumina...... cartridges was investigated to purify the eluate to obtain a suitable Tc-99m tracer with low Tc-99 concentration. The activity ratio of Tc-99/Tc-99m in the prepared Tc-99m solution is lower than 15 x 10(-9), which is higher than the theoretical ratio of less than 10 x 10(-9). The possible reason is discussed....... The Tc-99 in the 20 kBq spiked Tc-99m tracer was found to be less than 0.3mBq, which is lower than the detection limit of the radiometric method used for environmental samples. The purified Tc-99m eluate is used as yield tracer for the determination of low levels of Tc-99 in environmental samples. (c...

USP21 regulates Hippo pathway activity by mediating MARK protein turnover

DEFF Research Database (Denmark)

Nguyen, Thanh Hung; Kugler, Jan-Michael; Loya, Anand Chainsukh

2017-01-01

observed in cancer and often correlates with worse survival. The activity and stability of Hippo pathway components, including YAP/TAZ, AMOT and LATS1/2, are regulated by ubiquitin-mediated protein degradation. Aberrant expression of ubiquitin ligase complexes that regulate the turnover of Hippo components...

99mTc-EDTA and 99mTc-DTPA complexes as hydrological tracers

International Nuclear Information System (INIS)

Dominguez, J.; Borroto, J.; Nazco, J.; Perez, E.; Gamboa, R.; Cruz, J.

2002-01-01

The [ 99m Tc-DTPA] 2- and [ 99m Tc-EDTA] 1- were evaluated as radiotracers for short time hydrological studies. Their complex stability after labelling with 9.25 GBq of 99m Tc, the behaviour against pH variations, from 5 to 9, in simulated solutions and in natural river waters and the sorption of these compounds on the river sediments, were tested in laboratory experiments. Finally field double tracing experiments were carried out for each of labelling complexes and Rhodamine WT. From recovery calculations not losses of the 99m Tc activity were observed. The shape of the RTD curves of the [ 99m Tc-DTPA] 2- and [ 99m Tc-EDTA] 1 were quite similar to the Rhodamine Wt ones. May be concluded that both complexes behaved conservatively on the studied environmental conditions. (author)

Testing the radiochemical purity of a radiopharmaceutical: study of 99mTc-Tetrofosmin (Myoview)

International Nuclear Information System (INIS)

Moati, F.; Quartarone, C.; Jourdain, J.R.; Rizzo, N.; Dumont, A.; De Beco, V.; Ait Ben Ali, S.; Lours, S.; Piketty, M.L.; Izembart, M.; Goudou, C.; Lemercier, V.; Schlageter, M.H.; Moretti, J.L.; Progent, A.

1997-01-01

The goal of this study is to optimize the testing method of radiochemical purity (RCP) of 99m Tc-Tetrofosmin proposed by the Amersham Company: thin-layer chromatography (TLC); ITLC-SG support, migration on 15 Cm; acetone-dichloromethane mobile phase, (35/65, v/v), This technique allows separating the reduced-Tc (Rf = 0), the TcO 4 - (Rf = 1), and in intermediary position (0.2 99m Tc-Tetrofosmin. The results of RCP depend on working conditions, particularly, on the volume of deposit (10 to 20 μl, expected). If the deposited is too small, the 99m Tc-Tetrofosmin does not migrate. With a volume of 20 μl, the separation is weak and the peak width is un-resolvable. The results obtained correspond to the following operational conditions: migration on 8 cm; deposit of 8 to 10 μl; no drying. In these conditions the peak of 99m Tc-Tetrofosmin is well singled out: migration Rf of 0.375 to 0.625. These results have been obtained by the analysis of radio-chromatographic peak. Every strip has been cut cm by cm and the activity was measured by a gamma counter. Repeatability of the method on a series of 8 tests is good: average RCP 93.22%, mean value = 93.24%. The reproducibility was realized by measuring directly by the activity-meter the activity corresponding to 3 identifiable peaks: Reduced Tc (Rf 4 - (Rf 99m Tc-Tetrofosmin (0.25 < Rf < 0.75). On the 21 effectuated tests the inter-test RCP reproducibility was good: average value = 95.24%, CV = 2.07%, mean value 95.3%). In conclusion, the miniaturization improves the separation by Myoview (0.25 < Rf < 0.75), diminishes the migration time by a factor 4 and lowers the reactive cost of testing by 50%

Testing the radiochemical purity of a radiopharmaceutical: study of {sup 99m}Tc-Tetrofosmin (Myoview); Controle de la purete radiochimique d`un radiopharmaceutique: etude du {sup 99m}Tc-Tetrofosmin (Myoview)

Energy Technology Data Exchange (ETDEWEB)

Moati, F.; Quartarone, C.; Jourdain, J.R.; Rizzo, N.; Dumont, A.; De Beco, V.; Ait Ben Ali, S.; Lours, S.; Piketty, M.L.; Izembart, M.; Goudou, C.; Lemercier, V.; Schlageter, M.H.; Moretti, J.L.; Progent, A. [Groupe de travail `Radiopharmaceutiques - Ile de France` (France)

1997-12-31

The goal of this study is to optimize the testing method of radiochemical purity (RCP) of {sup 99m}Tc-Tetrofosmin proposed by the Amersham Company: thin-layer chromatography (TLC); ITLC-SG support, migration on 15 Cm; acetone-dichloromethane mobile phase, (35/65, v/v), This technique allows separating the reduced-Tc (Rf = 0), the TcO{sub 4}{sup -} (Rf = 1), and in intermediary position (0.2Tc-Tetrofosmin. The results of RCP depend on working conditions, particularly, on the volume of deposit (10 to 20 {mu}l, expected). If the deposited is too small, the {sup 99m}Tc-Tetrofosmin does not migrate. With a volume of 20 {mu}l, the separation is weak and the peak width is un-resolvable. The results obtained correspond to the following operational conditions: migration on 8 cm; deposit of 8 to 10 {mu}l; no drying. In these conditions the peak of {sup 99m}Tc-Tetrofosmin is well singled out: migration Rf of 0.375 to 0.625. These results have been obtained by the analysis of radio-chromatographic peak. Every strip has been cut cm by cm and the activity was measured by a gamma counter. Repeatability of the method on a series of 8 tests is good: average RCP 93.22%, mean value = 93.24%. The reproducibility was realized by measuring directly by the activity-meter the activity corresponding to 3 identifiable peaks: Reduced Tc (Rf < 0.25), TcO{sub 4}{sup -} (Rf < 0.75), and {sup 99m}Tc-Tetrofosmin (0.25 < Rf < 0.75). On the 21 effectuated tests the inter-test RCP reproducibility was good: average value = 95.24%, CV = 2.07%, mean value 95.3%. In conclusion, the miniaturization improves the separation by Myoview (0.25 < Rf < 0.75), diminishes the migration time by a factor 4 and lowers the reactive cost of testing by 50%

Targeting osteomyelitis with complete [99mTc]besilesomab and fragmented [99mTc]sulesomab antibodies: kinetic evaluations

International Nuclear Information System (INIS)

GRATZ, Stefan; KEMKE, Bendix; KEIZE, Patrik; KAMPEN, Wim U.; LUSTER, Markus; HÖFFKEN, Helmut

2016-01-01

The aim of this retrospective study was to compare the targeting of “pure” osteomyelitis (i.e., without surrounding soft tissue infection) by directly 99mTc-labelled complete immunoglobulin G (IgG) monoclonal antibody (MAb) ([99mTc]besilesomab) and by directly 99mTc-labelled fragment antigen-binding (FAb) MAb ([99mTc]sulesomab) in relation to their kinetic fate. A total of 73 patients with “pure” osteomyelitis were examined with [99mTc]besilesomab, (Scintimun®, IBA/CIS bio international, Saclay, France; N.=38) and [99mTc]sulesomab (LeukoScan®, Immunomedics Inc., Morris Plains, NJ, USA; N.=35). Kinetic data were deduced from whole-body and single-photon emission computed tomographic scans, performed 10 minutes to 24 hour p.i. (region-of-interest technique [ROI]). In targeting “pure” osteomyelitis, sensitivities at 1-4 hours were found to be higher for [99mTc]sulesomab (44% and 80% for [99mTc]besilesomab and [99mTc]sulesomab, respectively) but at significantly lower target/background (T/B) ratios than with [99mTc]besilesomab (1.8±0.3 versus 1.4±0.5 for [99mTc]besilesomab and [99mTc]sulesomab respectively; P<0.01). With [99mTc]besilesomab, there was a continuous osteomyelitis uptake over 24 hours, whereas with [99mTc]sulesomab, the maximal uptake occurred mostly within 1-4 hours, with subsequent clearance being slower for antigen-bound activity than for nonspecific background. Hence, diagnosis was possible mostly after 4h with [99mTc]sulesomab but often not before 24 hours with [99mTc]besilesomab, the later increasing significantly (P<0.01) in sensitivity (87% and 84% for [99mTc]besilesomab and [99mTc]sulesomab, respectively). These results show that the higher sensitivity of [99mTc]sulesomab in osteomyelitis targeting at earlier p.i. times does not rely on an increased antibody uptake but on a more rapid clearance of nonspecific background activity due to faster metabolism and excretion. Intact [99mTc]besilesomab show a slow, continuous uptake

Breast-milk radioactivity after a Tc-99m DTPA aerosol/Tc-99m MAA lung study

International Nuclear Information System (INIS)

Mountford, P.J.; Hall, F.M.; Wells, C.P.; Coakley, A.J.

1984-01-01

Measurements were made of the concentration of Tc-99m activity in samples of breast milk following an administration of Tc-99m DTPA aerosol for a lung ventilation image and one of Tc-99m MAA for lung perfusion. The activity was 222 nCi/ml of milk (8.2 kBq/ml) at 2 hr after the MAA injection, and it was found to be excreted exponentially with an effective half-life of 4.6 hr. There was a small incorporation of Tc-99m into breast-milk protein. The authors conclude that the combined use of these two Tc-99m agents did not indicate the interruption of breast feeding beyond 24 hr after administration of the MAA, and that for an aerosol ventiliation study alone, breast feeding need not be interrupted for more than 4 hr after the test

Differentiation of malignant and degenerative benign bone disease using 99mTc-citrate scintigraphy

International Nuclear Information System (INIS)

Guo Rui; Jin Jianhua; Li Sijin; Li Xianfeng; Zhang Xiaojuan; Ren Yuan

2008-01-01

Objective: To differentiate malignant and degenerative benign bone disease using 99m Tc- citrate scintigraphy. Methods: Thirty-nine patients (92 lesions) with confirmed malignant bone disease or degenerative benign bone disease were studied, for which the results of 99m Te-methylene diphosphonate( 99m Tc- MDP) scintigraphy were positive. 99m Tc-citrate scintigraphy was performed within a time interval of 2-7 days after 99m Tc-MDP scintigraphy. Visual analysis and semiquantitative analysis were applied. Each lesion was scored as malignant or benign, which was independently verified, using conventional techniques (histopathology, X-ray, CT, MRI and clinical follow up). Results: In visual analysis of 99m Tc-citrate imaging, most malignant lesions (35/48, 72.92%) clearly showed high radioactivity accumulation, while most benign lesions (39/44, 88.64%) had not obviously visible uptake of 99m Tc-citrate. In semiquantitative analysis of 99m Tc- citrate image, malignant lesions demonstrated a higher lesion-to-background radioisotope uptake ratio (RUR) than that of benign degenerative lesions (1.47 ± 0.42 vs. 1.09 ± 0.38, t=2.887, P 99m Tc-MDP in the two groups is of the same (1.96 ± 0.25 vs. 1.87 ± 0.21, t=1.178, P>0.20). Conclusion: 99m Tc- citrate scintigraphy is a promising method to differentiate malignant from benign degenerative lesions seen as areas of increased activity on 99m Tc-MDP bone scintigraphy. (authors)

Accumulation of Tc-99m-MIBI and Tc-99m-tetrofosmin in tumor cells. Uptake and washout studies

International Nuclear Information System (INIS)

Rodrigues, M.; Aghajanian, A.A.; Sinzinger, H.; Kalinowska, W.; Zielinski, C.

2002-01-01

Aim: To investigate in-vitro the uptake and washout of Tc-99m-MIBI and Tc-99m-tetrofosmin in human breast adenocarcinoma and soft tissue sarcoma cell lines. Methods: The uptake of Tc-99m-MIBI and Tc-99m-tetrofosmin (at 37 0 C, 10, 30 and 60 minutes after incubation with 7.4x10E5 Bq each tracer) was investigated in breast adenocarcinoma MCF-7 and SK-BR-3 cells, synovial sarcoma SW 982 cells and chondrosarcoma SW 1353 cells (concentration of 1x10E6 cells/ml incubation medium). Tracer uptake in cells incubated with ouabain (Na/K-ATPase pump inhibitor; 100 μM and 1mM; 15 and 30 minutes), nigericin (increases mitochondrial potential and disrupts cell membrane potential; 5 and 50 μg/ml; 15 minutes) and carbonyl cyanide m-chlorophenylhydrazone (CCCP) (depolarizes mitochondrial membrane; 10 and 100 μM; 30 minutes) was compared to that in cells without incubation with chemical agents (control cells). The washout (at 37 0 C, 10-60 minutes, 30 and 60 minutes after tracer incubation) of Tc-99m-MIBI and Tc-99m-tetrofosmin was studied in MCF-7 cells, SK-BR-3 cells , SW 1353 cells and fibrosarcoma SW 684 cells. Results: Cellular tracer uptake decreased with ouabain (decrease of Tc-99m-tetrofosmin > Tc-99m-MIBI in SK-BR-3 cells and SW 982 cells) and increased with nigericin (increase of Tc-99m-MIBI > Tc-99m-tetrofosmin in all cells) as compared to the uptake in control cells. With CCCP, decrease of Tc-99m-MIBI uptake in cells preincubated with nigericin was higher than that in cells under basal conditions, whereas a similar decrease of Tc-99m-tetrofosmin uptake in these two group of cells was found. Washout of Tc-99m-MIBI from all cells was lower than that of Tc-99m-tetrofosmin. No significant difference in cell-associated activity of both tracers was found between washout after 30 minutes and that after 60 minutes of incubation, in all cells. Washout of Tc-99m-MIBI from SK-BR-3 cells Tc-99m-tetrofosmin) and Na/K-ATPase pump (Tc-99m-tetrofosmin > Tc-99m-MIBI). Tc-99m-MIBI and

2'β-Fluoro-Tricyclo Nucleic Acids (2'F-tc-ANA): Thermal Duplex Stability, Structural Studies, and RNase H Activation.

Science.gov (United States)

Istrate, Alena; Katolik, Adam; Istrate, Andrei; Leumann, Christian J

2017-08-01

We describe the synthesis, thermal stability, structural and RNase H activation properties of 2'β-fluoro-tricyclo nucleic acids (2'F-tc-ANA). Three 2'F-tc-ANA nucleosides (T, 5Me C and A) were synthesized starting from a previously described fluorinated tricyclo sugar intermediate. NMR analysis and quantum mechanical calculations indicate that 2'F-tc-ANA nucleosides prefer sugar conformations in the East and South regions of the pseudorotational cycle. UV-melting experiments revealed that non-consecutive insertions of 2'F-tc-ANA units in DNA reduce the affinity to DNA and RNA complements. However, an oligonucleotide with five contiguous 2'F-tc-ANA-T insertions exhibits increased affinity to complementary RNA. Moreover, a fully modified 10-mer 2'F-tc-ANA oligonucleotide paired to both DNA (+1.6 °C/mod) and RNA (+2.5 °C/mod) with significantly higher affinity compared to corresponding unmodified DNA, and similar affinity compared to corresponding tc-DNA. In addition, CD spectroscopy and molecular dynamics simulations indicate that the conformation of the 2'F-tc-ANA/RNA duplex is similar to that of a DNA/RNA duplex. Moreover, in some sequence contexts, 2'F-tc-ANA promotes RNase H-mediated cleavage of a complementary RNA strand. Taken together, 2'F-tc-ANA represents a nucleic acid analogue that offers the advantage of high RNA affinity while maintaining the ability to activate RNase H, and can be considered a prospective candidate for gene silencing applications. © 2017 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.

Tc1-mediated contact sensitivity reaction, its mechanism and regulation

Directory of Open Access Journals (Sweden)

Magdalena Zemelka-Wiącek

2014-07-01

Full Text Available The contact hypersensitivity reaction (CHS to haptens is a classic example of cell-mediated immune response. In the effector phase, two stages can be distinguished: an early component, that appears only 2 hours after subsequent contact with the hapten, and the late component that develops approximately 24 hours later which is mediated by TCRαβ+ cells. The effector lymphocytes may be CD4+ T helper 1 (Th1 cells or CD8+ T cytotoxic 1 (Tc1 cells, which depends on the employed hapten and/or mice strain. NKT lymphocytes play the crucial role in the CHS initiation, by supporting B1 cells in the antigen-specific IgM antibodies production. The development of an early component is essential for the recruitment of T effector (Teff cells to the side of hapten deposition and for the complete expansion of inflammatory reaction. The CHS reaction is under T regulatory (Treg cells control, both in the induction phase as well as in the effector phase. A new view of a negative regulation of the Tc1 mediated CHS response is based on the suppression induced by epicutaneous (EC application of protein antigen. The DNP-BSA skin application, on a gauze patch, leads to a state of immunosuppression. This maneuver results in rising the population of Treg cells with TCRαβ+CD4+CD25+Foxp3+ phenotype. The mechanism of suppression requires direct contact between Treg cells and Teff cells and the participation of CTLA-4 molecule is also necessary. The described method of evoking immune tolerance via EC immunization may contribute to elaborate a new method of allergic contact dermatitis therapy. This is because of its effectiveness, ease of induction and non-invasive protein antigen application.

In vitro assessment of Tc-99m labeled bovine thrombin and streptokinase-activated human plasmin: concise communication. [Iodine 125

Energy Technology Data Exchange (ETDEWEB)

Wong, D.W.; Tanaka, T.; Mishkin, F.; Lee, T.

1979-09-01

Bovine thrombin and streptokinase-activated human plasmin have been labeled with Tc-99m using stannous reduction of pertechnetate under physiological conditions (pH 7.4). The binding efficiency of radiotechnetium to these enzymes is greater than 94%, with less than 5% of reduced but unbound Tc-99m (Sn) complex as assayed by ascending paper radiochromatography using ITLC silica gel plate. Free or unbound pertechnetate is less than 1%. In vitro enzymatic analyses of the Tc-99m-labeled enzymes demonstrate no evidence of protein denaturation or significant loss of enzymatic activity after labeling. Both labeled enzymes are biochemically active in vitro with their respective substrates.

p21-Activated kinase (PAK regulates cytoskeletal reorganization and directional migration in human neutrophils.

Directory of Open Access Journals (Sweden)

Asako Itakura

Full Text Available Neutrophils serve as a first line of defense in innate immunity owing in part to their ability to rapidly migrate towards chemotactic factors derived from invading pathogens. As a migratory function, neutrophil chemotaxis is regulated by the Rho family of small GTPases. However, the mechanisms by which Rho GTPases orchestrate cytoskeletal dynamics in migrating neutrophils remain ill-defined. In this study, we characterized the role of p21-activated kinase (PAK downstream of Rho GTPases in cytoskeletal remodeling and chemotactic processes of human neutrophils. We found that PAK activation occurred upon stimulation of neutrophils with f-Met-Leu-Phe (fMLP, and PAK accumulated at the actin-rich leading edge of stimulated neutrophils, suggesting a role for PAK in Rac-dependent actin remodeling. Treatment with the pharmacological PAK inhibitor, PF3758309, abrogated the integrity of RhoA-mediated actomyosin contractility and surface adhesion. Moreover, inhibition of PAK activity impaired neutrophil morphological polarization and directional migration under a gradient of fMLP, and was associated with dysregulated Ca(2+ signaling. These results suggest that PAK serves as an important effector of Rho-family GTPases in neutrophil cytoskeletal reorganization, and plays a key role in driving efficient directional migration of human neutrophils.

Fibroblast Growth Factor 21 Mediates Glycemic Regulation by Hepatic JNK

Directory of Open Access Journals (Sweden)

Santiago Vernia

2016-03-01

Full Text Available The cJun NH2-terminal kinase (JNK-signaling pathway is implicated in metabolic syndrome, including dysregulated blood glucose concentration and insulin resistance. Fibroblast growth factor 21 (FGF21 is a target of the hepatic JNK-signaling pathway and may contribute to the regulation of glycemia. To test the role of FGF21, we established mice with selective ablation of the Fgf21 gene in hepatocytes. FGF21 deficiency in the liver caused marked loss of FGF21 protein circulating in the blood. Moreover, the protective effects of hepatic JNK deficiency to suppress metabolic syndrome in high-fat diet-fed mice were not observed in mice with hepatocyte-specific FGF21 deficiency, including reduced blood glucose concentration and reduced intolerance to glucose and insulin. Furthermore, we show that JNK contributes to the regulation of hepatic FGF21 expression during fasting/feeding cycles. These data demonstrate that the hepatokine FGF21 is a key mediator of JNK-regulated metabolic syndrome.

DNA double-strand breaks in blood lymphocytes induced by two-day 99mTc-MIBI myocardial perfusion scintigraphy.

Science.gov (United States)

Rief, Matthias; Hartmann, Lisa; Geisel, Dominik; Richter, Felicitas; Brenner, Winfried; Dewey, Marc

2018-07-01

To investigate DNA double-strand breaks (DSBs) in blood lymphocytes induced by two-day 99m Tc-MIBI myocardial perfusion scintigraphy (MPS) using y-H2AX immunofluorescence microscopy and to correlate the results with 99m Tc activity in blood samples. Eleven patients who underwent two-day MPS were included. DSB blood sampling was performed before and 5min, 1h and 24h after the first and second radiotracer injections. 99m Tc activity was measured in each blood sample. For immunofluorescence microscopy, distinct foci representing DSBs were quantified in lymphocytes after staining for the phosphorylated histone variant y-H2AX. The 99m Tc-MIBI activity measured on days one and two was similar (254±25 and 258±27 MBq; p=0.594). Compared with baseline DSB foci (0.09±0.05/cell), a significant increase was found at 5min (0.19±0.04/cell) and 1h (0.18±0.04/cell) after the first injection and at 5min and 1h after the second injection (0.21±0.03 and 0.19±0.04/cell, respectively; p=0.003 for both). At 24h after the first and second injections, the number of DSB foci had returned to baseline (0.06±0.02 and 0.12±0.05/cell, respectively). 99m Tc activity levels in peripheral blood samples correlated well with DSB counts (r=0.451). DSB counts reflect 99m Tc-MIBI activity after injection for two-day MPS, and might allow individual monitoring of biological effects of cardiac nuclear imaging. • Myocardial perfusion scintigraphy using 99m Tc induces time-dependent double-strand breaks (DSBs) • γ-H2AX immunofluorescence microscopy shows DSB as an early response to radiotracer injection • Activity measurements of 99m Tc correlate well with detected DSB • DSB foci induced by 99m Tc return to baseline 24h after radiotracer injection.

P21-activated kinase 2 (PAK2) regulates glucose uptake and insulin sensitivity in neuronal cells.

Science.gov (United States)

Varshney, Pallavi; Dey, Chinmoy Sankar

2016-07-05

P21-activated kinases (PAKs) are recently reported as important players of insulin signaling and glucose homeostasis in tissues like muscle, pancreas and liver. However, their role in neuronal insulin signaling is still unknown. Present study reports the involvement of PAK2 in neuronal insulin signaling, glucose uptake and insulin resistance. Irrespective of insulin sensitivity, insulin stimulation decreased PAK2 activity. PAK2 downregulation displayed marked enhancement of GLUT4 translocation with increase in glucose uptake whereas PAK2 over-expression showed its reduction. Treatment with Akti-1/2 and wortmannin suggested that Akt and PI3K are mediators of insulin effect on PAK2 and glucose uptake. Rac1 inhibition demonstrated decreased PAK2 activity while inhibition of PP2A resulted in increased PAK2 activity, with corresponding changes in glucose uptake. Taken together, present study demonstrates an inhibitory role of insulin signaling (via PI3K-Akt) and PP2A on PAK2 activity and establishes PAK2 as a Rac1-dependent negative regulator of neuronal glucose uptake and insulin sensitivity. Copyright © 2016 Elsevier Ireland Ltd. All rights reserved.

TcA, the putative transposase of the C. elegans Tc1 transposon, has an N-terminal DNA binding domain.

OpenAIRE

Schukkink, R F; Plasterk, R H

1990-01-01

Tc1 is a transposon present in several copies in the genome of all natural isolates of the nematode C.elegans; it is actively transposing in many strains. In those strains Tc1 insertion is the main cause of spontaneous mutations. The transposon contains one large ORF that we call TcA; we assume that the TcA protein is the transposase of Tc1. We expressed TcA in E.coli, purified the protein and showed that it has a strong affinity for DNA (both single stranded and double stranded). A fusion pr...

{sup 201}Tl, {sup 99m}Tc-MIBI, {sup 99m}Tc-tetrofosmin and {sup 99m}Tc-furifosmin: relative retention and clearance kinetics in retrogradely perfused guinea pig hearts

Energy Technology Data Exchange (ETDEWEB)

Schaefer, Wolfgang M.; Moka, Detlef E-mail: detlef.moka@uni-koeln.de; Brockmann, Holger A.; Schomaecker, Klaus; Schicha, Harald

2002-02-01

Myocellular kinetics of {sup 201}Tl, {sup 99m}Tc-MIBI, {sup 99m}Tc-tetrofosmin and {sup 99m}Tc-furifosmin were investigated using retrogradely-perfused guinea-pig hearts. Relative retention decreased in the order {sup 99m}Tc-MIBI {yields}{yields} implies {sup 99m}Tc-tetrofosmin {yields}{yields} implies {sup 99m}Tc-furifosmin. {sup 201}Tl and {sup 99m}Tc-MIBI exhibited bi- (t1,t2), {sup 99m}Tc-tetrofosmin and {sup 99m}Tc-furifosmin triexponential (t1,t2,t3) time-activity-curves. Latest-phase elimination-half-life increased from {sup 201}Tl (t2) {yields}{yields} implies {sup 99m}Tc-MIBI (t2) {yields}{yields} implies {sup 99m}Tc-tetrofosmin (t3) {yields}{yields} implies {sup 99m}Tc-furifosmin (t3), showing a significant increase in deteriorating myocardium for all tracers but {sup 99m}Tc-furifosmin. Delayed elimination in deteriorating myocardium explains at least partly the redistribution phenomenon of {sup 201}Tl, and suggests a similar phenomenon for {sup 99m}Tc-MIBI and {sup 99m}Tc-tetrofosmin.

Knockdown of TC-1 enhances radiosensitivity of non-small cell lung cancer via the Wnt/β-catenin pathway.

Science.gov (United States)

Wu, Dapeng; Li, Lei; Yan, Wei

2016-04-15

Thyroid cancer 1 (TC-1, C8ofr4) is widely expressed in vertebrates and associated with many kinds of tumors. Previous studies indicated that TC-1 functions as a positive regulator in the Wnt/β-catenin signaling pathway in non-small cell lung cancer (NSCLC). However, its exact role and regulation mechanism in radiosensitivity of NSCLC are still unclear. The expression level of TC-1 was measured by qRT-PCR and western blot in NSCLC cell lines. Proliferation and apoptosis of NSCLC cells in response to TC-1 knockdown or/and radiation were determined by MTT assay and flow cytometry, respectively. The activation of the Wnt/β-catenin signaling pathway was further examined by western blotin vitroandin vivo Compared to TC-1 siRNA or radiotherapy alone, TC-1 silencing combined with radiation inhibited cell proliferation and induced apoptosis in NSCLC cell lines by inactivating of the Wnt/β-catenin signaling pathway. Furthermore, inhibition of the Wnt/β-catenin signaling pathway by XAV939, a Wnt/β-catenin signaling inhibitor, contributed to proliferation inhibition and apoptosis induction in NSCLC A549 cells. Combinative treatment of A549 xenografts with TC-1 siRNA and radiation caused significant tumor regression and inactivation of the Wnt/β-catenin signaling pathway relative to TC-1 siRNA or radiotherapy alone. The results fromin vitroandin vivostudies indicated that TC-1 silencing sensitized NSCLC cell lines to radiotherapy through the Wnt/β-catenin signaling pathway. © 2016. Published by The Company of Biologists Ltd.

Synaptic activity regulates AMPA receptor trafficking through different recycling pathways

Science.gov (United States)

Zheng, Ning; Jeyifous, Okunola; Munro, Charlotte; Montgomery, Johanna M; Green, William N

2015-01-01

Changes in glutamatergic synaptic strength in brain are dependent on AMPA-type glutamate receptor (AMPAR) recycling, which is assumed to occur through a single local pathway. In this study, we present evidence that AMPAR recycling occurs through different pathways regulated by synaptic activity. Without synaptic stimulation, most AMPARs recycled in dynamin-independent endosomes containing the GTPase, Arf6. Few AMPARs recycled in dynamin-dependent endosomes labeled by transferrin receptors (TfRs). AMPAR recycling was blocked by alterations in the GTPase, TC10, which co-localized with Arf6 endosomes. TC10 mutants that reduced AMPAR recycling had no effect on increased AMPAR levels with long-term potentiation (LTP) and little effect on decreased AMPAR levels with long-term depression. However, internalized AMPAR levels in TfR-containing recycling endosomes increased after LTP, indicating increased AMPAR recycling through the dynamin-dependent pathway with synaptic plasticity. LTP-induced AMPAR endocytosis is inconsistent with local recycling as a source of increased surface receptors, suggesting AMPARs are trafficked from other sites. DOI: http://dx.doi.org/10.7554/eLife.06878.001 PMID:25970033

Proficiency tests for evaluation of the {sup 99}Tc{sup m} measurements in the nuclear medicine; Aplicacao de teste de proficiencia para avaliacao da medicao de {sup 99}Tc{sup m} na medicina nuclear

Energy Technology Data Exchange (ETDEWEB)

Iwahara, Akira; Tauhata, Luiz; Oliveira, Antonio Eduardo de, E-mail: iwahara@ird.gov.b, E-mail: tauhata@ird.gov.b, E-mail: aedu@ird.gov.b [Instituto de Radioprotecao e Dosimetria (IRD/CNEN-RJ), Rio de Janeiro, RJ (Brazil); Nicoli, Ieda Gomes, E-mail: ieda@ird.gov.b [Comissao Nacional de Energia Nuclear (CNEN/DF), Brasilia, DF (Brazil). Escritorio de Brasilia; Alabarse, Frederico Gil; Xavier, Ana Maria, E-mail: falabarse@ird.gov.b, E-mail: axavier@ird.gov.b [Comissao Nacional de Energia Nuclear (ESPOA/CNEN-RS), Porto Alegre, RS (Brazil). Escritorio de Porto Alegre

2009-07-01

This work performs the performance evaluation of 55 Brazilian nuclear medicine services in activity measurement of radiopharmaceutical containing {sup 99}Tc{sup m}. Proficiency tests based on the acceptance criteria of the Regulation ISO/IEC Guide 43-1 and on the accuracy of the brazilian Regulation CNEN-NN-3.05 were applied in 63 results of activity measurements in radionuclide calibrators used by those services. The performance services has shown that the criteria of the ISO/IEC 43-1, nevertheless to be more restrictive, presents results very consistent with the accuracy criteria requested by the Brazilian regulation

Determination of Tc-99 in radioactive wastes

International Nuclear Information System (INIS)

Rivera S, A. A.

2015-01-01

Tc-99 is a fission product and one of the most important radionuclides from the view point of safety assessment for the disposal of radioactive waste because of its long half-life (2.1 x 10 5 years) and high mobility in soil-water systems, if this is released into the environment in significant quantities can concentrate on plants and animals. Tc-99 is a pure beta emitter with a maximum energy of 292 KeV, so their quantification imposes destructive methods to be analyzed by liquid scintillation. Therefore the quantification of Tc-99 in ion exchange resins requires of the mineralization of these and separation of Tc-99 of other radioisotopes present in the resin. Therefore the object of this thesis is to develop a quantification method of Tc-99 content in spent exchange resins. So in order to track the behavior of technetium during digestion exchange resins and radiochemical separation, given its high volatility, in this work the 99m Tc is used. To determine the degree of mineralization of the resins, an analysis was performed by chromatography. Subsequently the method used to determine the percentage of 99m Tc aerosolized during mineralization of resin is described. After the method for the radiochemical separation of 99m Tc is presented by liquid-liquid extraction using crown ether as extractant; for this testing was performed by varying the molarity of the extractant, the ratio of solvent extractant, type of digestion of the resin and the presence of Sr-85, in order to study the behavior of 99m Tc in the presence of this radioisotope. Finally, a track beta spectra of a sample of 99m Tc eluted from a generator 99 Mo/ 99m Tc function of time was performed. (Author)

Biokinetics and dosimetry of a hybrid formulation of 9mTc-BN and 99mTc-RGD2 starting from optic images in a murine model

International Nuclear Information System (INIS)

Cornejo A, L. G.

2015-01-01

This work has the purpose of evaluate the biokinetics and absorbed dose of radiation of hybrid formulation 99m Tc-BN / 99m Tc-RGD 2 in a murine model by optical imaging techniques using the multimodal preclinical in vivo image system Xtreme. The used method were the 99m Tc-BN, 99m Tc-RGD 2 and 99m Tc-BN/ 99m Tc-RGD 2 formulas, with specific recognition for GRPr and the integrin s α(v)β(3) and α(v)β(5) respectively, was injected in the vein tail of three nude mousses with induce breast cancer tumors (cell line T-47-D), by the preclinical multimodal imaging system Xtreme (Bruker), optical images in different times was acquired (5, 10, 20 min, 2 and 24 h), using Images Processing Toolbox of MATLAB these images was transform from RGB format to gray scales and sectioned in five independent images corresponding to heart, kidneys, bladder and tumor areas. The intensity of each images was computed in counts per pixel, then those intensities was corrected for background, attenuation and scattering, using different factors for each phenomena previously calculated. Finally the activity values quantified vs time was fitted into a biokinetic model to obtain the disintegrations number and cumulate activities in each organ. With these data the radiation absorbed dose were calculated using MIRD methodology. Results: The number of disintegration and absorbed dose calculated in MBq h/MBq and mGy/MBq, of injected mouse with the 99m Tc-BN/ 99m Tc-RGD 2 formulation, was: 0.035 ± 0.65 E-02, 0.25 x 10 -5 ± 0.46 E-07; 0.393 ± 0.51 E-1, 2.85 E-05 ± 3.7 E-06; 0.306 ± 0.21 E-01, 2.11 E-05 ± 1.45 E-06 and 0.151 ± 0.19 E-01, 1.09 E-05 ± 1.42 E-06 , in heart, kidneys, bladder and tumor, respectively. The number of disintegration obtained in kidneys is comparable to those reported for Trinidad B. 2014 Conclusions: Our results demonstrated that using optical images and a code for image analyses development in MATLAB, could achieve comparable quantitative results as the conventional

Dissecting biochemical peculiarities of the ATPase activity of TcSub2, a component of the mRNA export pathway in Trypanosoma cruzi.

Science.gov (United States)

Bittencourt, Ize de Aguiar; Serpeloni, Mariana; Hiraiwa, Priscila Mazzochi; de Arruda Campos Brasil de Souza, Tatiana; Ávila, Andréa Rodrigues

2017-05-01

The RNA helicase DEAD-box protein Sub2 (yeast)/UAP56 (mammals) is conserved across eukaryotes and is essential for mRNA export in trypanosomes. Despite the high conservation of Sub2 in lower eukaryotes such as Trypanosoma cruzi, the low conservation of other mRNA export factors raises questions regarding whether the mode of action of TcSub2 is similar to that of orthologs from other eukaryotes. Mutation of the conserved K87 residue of TcSub2 abolishes ATPase activity, showing that its ATPase domain is functional. However, the Vmax of TcSub2 was much higher than the Vmax described for the human protein UAP56, which suggests that the TcSub2 enzyme hydrolyzes ATP faster than its human homolog. Furthermore, we demonstrate that RNA association is less important to the activity of TcSub2 compared to UAP56. Our results show differences in activity of this protein, even though the structure of TcSub2 is very similar to UAP56. Functional complementation assays indicate that these differences may be common to other trypanosomatids. Distinct features of RNA influence and ATPase efficiency between UAP56 and TcSub2 may reflect distinct structures for functional sites of TcSub2. For this reason, ligand-based or structure-based methodologies can be applied to investigate the potential of TcSub2 as a target for new drugs. Copyright © 2017 Elsevier B.V. All rights reserved.

In vivo distribution of Tc-99m labeled recombinant tissue-type plasminogen activator in control and thrombus-bearing rats

International Nuclear Information System (INIS)

Tsukamoto, Eriko

1992-01-01

In vivo distribution of Tc-99m labeled recombinant tissue-type plasminogen activator (Tc-99m-rt-PA) was studied in control rats and thrombus-bearing rats. To compare fibrin binding in vivo with that in vitro, Tc-99m-rt-PA binding to fibrin gel in vitro was also imaged. Rapid blood clearance and accumulation into the liver and kidneys were observed in both control and thrombus-bearing rats. Accumulation in the stomach, which indicates instability of labeled rt-PA in vivo, was very low until two hours after injection. Tc-99m-rt-PA accumulation in the clots was higher than that in skeletal and heart muscles, although it was lower than in blood, liver, and kidneys. Administration of aprotinin, an antifibrinolytic agent, significantly prolonged clot accumulation of Tc-99m-rt-PA at 30 minutes after injection. These results suggest that fibrinolysis is responsible for the low rt-PA concentration in the clots. A scintigram of a thrombus-bearing rat demonstrated increased radioactivity at the clot forming site. On the other hand, Tc-99m-labeled human albumin, which was used as a control, was not accumulated in the clot. Tc-99m-rt-PA binding to fibrin gel in vitro was clearly imaged. By comparison, in vivo fibrin binding of Tc-99m-rt-PA was much lower than in vitro. The reasons for low thrombus uptake in vivo may be: (1) biochemical inactivation of extrinsically administered rt-PA by t-PA inhibitor; (2) fibrinolysis by rt-PA activated plasminogen. Overcoming these limitations will enable Tc-99m-rt-PA to reach the stage of clinical trials. (author)

Code of Federal Regulations Title 21

Data.gov (United States)

U.S. Department of Health & Human Services — This database contains the most recent revision from the Government Printing Office (GPO) of the Code of Federal Regulations (CFR) Title 21 - Food and Drugs.

7 CFR 922.321 - Apricot Regulation 21.

Science.gov (United States)

2010-01-01

... 7 Agriculture 8 2010-01-01 2010-01-01 false Apricot Regulation 21. 922.321 Section 922.321 Agriculture Regulations of the Department of Agriculture (Continued) AGRICULTURAL MARKETING SERVICE (Marketing... least as yellow as Shade 3 on U.S. Department of Agriculture Standard Ground Color Chart of Apples and...

The value of Tc-99m MIBI scintigraphy in active disease and remission phase of multiple myeloma

International Nuclear Information System (INIS)

Saghari, M.; Fallahi, B.; Eftekhari, M.; Irvani, M.; Izadyar, S.; Esmaili, J.; Beiki, D.; Fard, A.

2004-01-01

Background: 99m Tc methoxy isobutyl isonitrile ( 99m Tc -MIBI)has been proposed as a tumor seeking agent in malignant disease. The goal of this study is to evaluate the frequency distribution of the different patterns, intensity and extension of abnormal uptake identified in MIBI scan in relation with various clinical status of the patients diagnosed as a multiple myeloma. Methods: forty-three patients entered the study, including six patients with no prior treatment , 22 patients who received autologous bone morrow graft, and 15 patients with history of chemotherapy and radiotherapy. Plasma protein electrophoresis for monoclonal antibody, bone morrow biopsy and urine analysis for Bence-Jones protein has been carried out and standard criteria were used for diagnosis of active disease and remission phase for each patients. The extension of each lesion(E-score) on scintigraphy were categorized into E 0 -E 3 by three nuclear physicians who were blinded to the patient's clinical condition. I-score was also obtained with comparing the intensity of the lesions with intensity of myocardial uptake and classified as I 0 -I 3 . Results: the sensitivity, specificity, positive predictive value and negative predictive value of 99m Tc -MIBI scan for determining active lesions and released cases were 69%, 100%, 100% and 60%, respectively. Nineteen patients were initially thought to be in remission phase, but scintigraphy was abnormal in 5 cases who were diagnosed as active myeloma later in the course of the study. There was a significant correlation between clinical status and pattern, intensity and extension of the abnormal uptake of 99m Tc -MIBI. Also a significant correlation between intensity and extension of the abnormal tracer uptake with serum monoclonal component and urine Bence-Jones protein was noted, however no correlation between blood hemo globulin and degree of extension in scintigraphy was seen. Conclusion: Our study suggests the pattern, extension and intensity of

Tc-99m Ciprofloxacin SPECT of Pulmonary Tuberculosis

Energy Technology Data Exchange (ETDEWEB)

Lee, Min Kyung; Hwang, Kyung Hoon [Gachon University Gil Hospital, Incheon (Korea, Republic of); Yoon, Min Ki [Good Samaritan Hospital, Pohang (Korea, Republic of); Choe, Won Sick [Kangbuk Samsung Hospital, Seoul (Korea, Republic of)

2010-06-15

Tc-99m ciprofloxacin is available for imaging infection. However, there has been no study on employing single photon emission computed tomography (SPECT) with using Tc-99m ciprofloxacin to image active pulmonary tuberculosis. Therefore, we conducted this study to assess the efficacy of Tc-99m ciprofloxacin SPECT for imaging active pulmonary tuberculosis. Twenty-one participants were enrolled in this prospective study. They were divided into two groups according to the clinical and radiological assessment. Group one (Gr. 1) consisted of five normal volunteers and six patients with inactive pulmonary tuberculosis. Group two (Gr. 2) consisted of ten patients with active pulmonary tuberculosis. SPECT was performed 3 h after injecting 555 MBq (15 mCi) of Tc-99m ciprofloxacin. The findings of Tc-99m ciprofloxacin SPECT were interpreted by a nuclear medicine specialist and then the results were analyzed according to the patients' clinical and radiological classifications. The results of Tc-99m ciprofloxacin SPECT were as follows: eight true-positive cases, ten true-negative cases, one false-positive case and two false-negative cases. The sensitivity and specificity was 80.0% and 90.0%, respectively. The positive predictive value was 88.9% and the negative predictive value was 83.3%. Conclusions Tc-99m ciprofloxacin SPECT is feasible for imaging active pulmonary tuberculosis. It is a useful nuclear-imaging method for discriminating between the active and inactive tuberculosis states in patients with a past medical history of pulmonary tuberculosis.

21 CFR 880.5560 - Temperature regulated water mattress.

Science.gov (United States)

2010-04-01

... 21 Food and Drugs 8 2010-04-01 2010-04-01 false Temperature regulated water mattress. 880.5560... Therapeutic Devices § 880.5560 Temperature regulated water mattress. (a) Identification. A temperature regulated water mattress is a device intended for medical purposes that consists of a mattress of suitable...

Artificial induction of Sox21 regulates sensory cell formation in the embryonic chicken inner ear.

Directory of Open Access Journals (Sweden)

Stephen D Freeman

Full Text Available During embryonic development, hair cells and support cells in the sensory epithelia of the inner ear derive from progenitors that express Sox2, a member of the SoxB1 family of transcription factors. Sox2 is essential for sensory specification, but high levels of Sox2 expression appear to inhibit hair cell differentiation, suggesting that factors regulating Sox2 activity could be critical for both processes. Antagonistic interactions between SoxB1 and SoxB2 factors are known to regulate cell differentiation in neural tissue, which led us to investigate the potential roles of the SoxB2 member Sox21 during chicken inner ear development. Sox21 is normally expressed by sensory progenitors within vestibular and auditory regions of the early embryonic chicken inner ear. At later stages, Sox21 is differentially expressed in the vestibular and auditory organs. Sox21 is restricted to the support cell layer of the auditory epithelium, while it is enriched in the hair cell layer of the vestibular organs. To test Sox21 function, we used two temporally distinct gain-of-function approaches. Sustained over-expression of Sox21 from early developmental stages prevented prosensory specification, and abolished the formation of both hair cells and support cells. However, later induction of Sox21 expression at the time of hair cell formation in organotypic cultures of vestibular epithelia inhibited endogenous Sox2 expression and Notch activity, and biased progenitor cells towards a hair cell fate. Interestingly, Sox21 did not promote hair cell differentiation in the immature auditory epithelium, which fits with the expression of endogenous Sox21 within mature support cells in this tissue. These results suggest that interactions among endogenous SoxB family transcription factors may regulate sensory cell formation in the inner ear, but in a context-dependent manner.

Tc Reductant Chemistry and Crucible Melting Studies with Simulated Hanford Low-Activity Waste

Energy Technology Data Exchange (ETDEWEB)

Kim, Dong-Sang; Soderquist, Chuck Z.; Icenhower, Jonathan P.; McGrail, B PETER.; Scheele, Randall D.; McNamara, Bruce K.; Bagaasen, Larry M.; Schweiger, Michael J.; Crum, Jarrod V.; Yeager, John D.; Matyas, Josef; Darnell, Lori P.; Schaef, Herbert T.; Owen, Antionette T.; Kozelisky, Anne E.; Snow, Lanee A.; Steele, Marilyn J.

2005-03-30

The FY 2003 risk assessment (RA) of bulk vitrification (BV) waste packages used 0.3 wt% of the technetium (Tc) inventory as a leachable salt and found it sufficient to create a significant peak in the groundwater concentration in a 100-meter down-gradient well. Although this peak met regulatory limits, considering uncertainty in the actual Tc salt fraction, peak concentrations could exceed the maximum concentration limit (MCL) under some scenarios so reducing the leachable salt inventory is desirable. The main objective of this study was to reduce the mobile Tc species available within a BV disposal package by reducing the oxidation state of the Tc in the waste feed and/or during melting because Tc in its reduced form of Tc(IV) has a much lower volatility than Tc(VII). Reduced Tc volatility has a secondary benefit of increasing the Tc retention in glass.

Trichocystatin-2 (TC-2): an endogenous inhibitor of cysteine proteinases in Trichomonas vaginalis is associated with TvCP39.

Science.gov (United States)

Puente-Rivera, Jonathan; Ramón-Luing, Lucero de los Ángeles; Figueroa-Angulo, Elisa Elvira; Ortega-López, Jaime; Arroyo, Rossana

2014-09-01

The causal agent of trichomoniasis is a parasitic protist, Trichomonas vaginalis, which is rich in proteolytic activity, primarily carried out by cysteine proteases (CPs). Some CPs are known virulence factors. T. vaginalis also possesses three genes encoding endogenous cystatin-like CP inhibitors. The aim of this study was to identify and characterize one of these CP inhibitors. Using two-dimensional gel electrophoresis (2-DE) and mass spectrometry (MS), a cystatin-like peptidase inhibitor dubbed Trichocystatin-2 (TC-2) was identified in the T. vaginalis active degradome in association with TvCP39, a 39kDa CP involved in cytotoxicity. To characterize the TC-2 inhibitor, we cloned and expressed the tvicp-2 gene, purified the recombinant protein (TC-2r), and produced a specific polyclonal antibody (α-TC-2r). This antibody recognized a 10kDa protein band by western blotting. An indirect immunofluorescence assay (IFA) and cell fractionation assays using the α-TC-2r antibody showed that TC-2 was localized in the cytoplasm and lysosomes and that it colocalized with TvCP39. TC-2r showed inhibitory activity against papain, cathepsin-L, and TvCP39 in trichomonad extracts and live parasites but not legumain-like CPs. Live trichomonads treated with TC-2r showed reduced trichomonal cytotoxicity to HeLa cell monolayers in a TC-2r-concentration-dependent manner. In this study, we identified and characterized an endogenous cystatin-like inhibitor in T. vaginalis, TC-2, which is associated with TvCP39 and appears to regulate the cellular damage caused by T. vaginalis. Copyright © 2014 Elsevier Ltd. All rights reserved.

21 CFR 71.20 - Publication of regulation.

Science.gov (United States)

2010-04-01

... 21 Food and Drugs 1 2010-04-01 2010-04-01 false Publication of regulation. 71.20 Section 71.20... ADDITIVE PETITIONS Administrative Action on Petitions § 71.20 Publication of regulation. The Commissioner will forward for publication in the Federal Register, within 90 days after filing of the petition (or...

sup(99m)Tc-2-mercaptopropionylglycine

International Nuclear Information System (INIS)

Saji, Hideo; Odori, Teruo; Morita, Rikushi; Yokoyama, Akira; Tanaka, Hisashi.

1979-01-01

Labeling of 2-mercaptopropionylglycine (2-MPG) with sup(99m)Tc, was studied and its chemical characteristics were examined. Further, biliary excretion behavior of this complex was comparatively estimated in mice, rats and rabbits. sup(99m)Tc-2-MPG was rapidly excreted in large quantities into the bile in mice and rats: within 1 hr after injection, 51% of the injected dose was recovered from the bile in rats. On the other hand, the ligand exchange reaction between this complex and penicillamine indicates that a low hydrolyzed sup(99m)Tc species is coordinated with 2-MPG. These results suggest that a low hydrolyzed sup(99m)Tc state is an effective feature in biliary excretion behavior of sup(99m)Tc compounds. Another interesting in vivo behavior of sup(99m)Tc-2-MPG is the difference observed in mice and rabbits: in mice, very high sup(99m)Tc activity is concentrated in the gallbladder and the clearance from tissues other than the gallbladder is rapid, whereas in rabbits, although a rapid and high excretion into the gallbladder is observed, a considerable high sup(99m)Tc activity is retained in the liver and the kidney. One reason for this different in vivo behavior is the low stability of this complex at high dilution: a big animal has the large dilution volume which lead to higher decomposition estimated by the higher liver and kidney retention or the lower bile excretion. In conclusion, studies carried on sup(99m)Tc-2-MPG showed a good biliary excretion behavior but an in vivo unstableness in big animals. (author)

Volume corrections factors in the measurement of 99mTc and 123I activities in radionuclide calibrators

International Nuclear Information System (INIS)

Correia, Amanda Ribeiro; Rezende, Eduarda Alexandre; Iwahara, Akira; Oliveira, Antonio Eduardo de; Oliveira, Estela Maria de; Tauhata, Luiz; Chaves, Taina Olivieri

2012-01-01

To determine correction factors for the variation in volume of radiopharmaceuticals in containers of different geometries, comparing the influence of such factors on the determination of 99m Tc and 123 I activity with two types of calibrators - one with ionization chamber and another with Geiger-Mueller (G-M) detector -; and to evaluate calibrators performance in the measurement of 99m Tc and 1 '2 3 I activities. Materials and Methods: Eight calibrators, 10R glass vials, 3 and 5 mL plastic syringes and 99m Tc and 123 I solutions were utilized. The correction factors were determined with basis on practical measurements of the variation in the calibrators' response according to the volume of radionuclide solution in the glass vials. The performance was evaluated according to the acceptance criterion of +- 10% accuracy required by the Brazilian standard. Results: The variation of the calibrators' response according to the variation in radionuclide volume was reasonably greater in the calibrator with G-M detector. It was also greater for 123 I than for 99m Tc. Conclusion: The results confirm that the calibrators' response depends on the radionuclide volume contained in the vials. Such dependence is more critical for the calibrators equipped with G-M detector and for 123 I as compared with 99m Tc. (author)

TIS21/(BTG2) negatively regulates estradiol-stimulated expansion of hematopoietic stem cells by derepressing Akt phosphorylation and inhibiting mTOR signal transduction.

Science.gov (United States)

Kim, Bong Cho; Ryu, Min Sook; Oh, S Paul; Lim, In Kyoung

2008-09-01

It has been known that 12-O-tetradecanoyl phorbol-13-acetate-inducible sequence 21 (TIS21), ortholog of human B-cell translocation gene 2, regulates expansions of stage-specific thymocytes and hematopoietic progenitors. In the present study, lineage-negative (Lin(-))/stem cell antigen-1-positive (Sca-1+)/c-Kit+ (LSK) cell content was significantly elevated in bone marrow (BM) of TIS21-knockout (TIS21(-/-)) female mice, suggesting 17beta-estradiol (E(2))-regulated progenitor expansion. E(2) induced DNA synthesis and cell proliferation of mouse embryonic fibroblasts (MEFs) isolated from TIS21(-/-) mice, but not wild type (WT). In contrast to WT, E(2) failed to activate protein kinase B (Akt) in the TIS21(-/-) MEFs, independent of extracellular signal-regulated kinase 1/2 (Erk1/2) activation. Despite attenuation of Akt activation, mammalian target of rapamycin (mTOR) was constitutively activated in the TIS21(-/-) MEFs. Furthermore, mitogen-activated protein kinase 1/2 inhibitor or knockdown of Erk1 could restore activation of Akt and downregulate mTOR. Immunoprecipitation showed Akt preferentially bound to phosphorylated Erk1/2 (p-Erk1/2) in TIS21(-/-) cells, but reconstitution of TIS21 inhibited their interaction. E(2)-injected TIS21(-/-) male mice also increased LSK cells in BM. Taken together, expansion of hematopoietic progenitors in TIS21(-/-) female mice might be through inhibition of Akt activation, and constitutive activation of mTOR via preferential binding of TIS21 to E(2)-induced p-Erk1/2, compared with that of Akt. Our results suggest that TIS21 plays a pivotal role in maintaining the hematopoietic stem cell compartment and hematopoiesis.

21 CFR 870.5900 - Thermal regulating system.

Science.gov (United States)

2010-04-01

... system. (a) Identification. A thermal regulating system is an external system consisting of a device that is placed in contact with the patient and a temperature controller for the device. The system is used... 21 Food and Drugs 8 2010-04-01 2010-04-01 false Thermal regulating system. 870.5900 Section 870...

Preparation and chemical studies on Tc(III) complexes containing polyaminocarboxylic acids

International Nuclear Information System (INIS)

Gonzalez, R.; Kremer, C.; Chiozzone, R.; Torres, J.; Rivero, M.; Kremer, E.; Leon, A.

1998-01-01

Tc(III)-edta (edta = ethylenediaminetetraacetate), Tc(III)-dtpa (dtpa = diethylenetriaminepentaacetate) and Tc(III)-mebrofenin (mebrofenin = 3-bromo-2,4,6-trimethylacetanilideiminodiacetate) complexes were prepared by ligand substitution reactions on hexakis(thiourea)technetium(III) cation with the polycarboxylates. By a combination of different techniques (UV-Vis, IR and 1 H-NMR spectroscopy, Tc elemental analyses and cerimetric titrations) it was concluded that 1:1 complexes are formed with edta and dtpa while mebrofening adopts a 2:1 (ligand to metal) stoichiometry. Complementary, molecular mechanics calculations were performed to analyze the spatial arrangement of the molecules. The stability of the Tc(III) complexes was studied in aqueous solution by paper chromatography, paper electrophoresis and cyclic voltammetry. The chelates are rather stable, in particular when compared with the precursor. (orig.)

Tc1 mouse model of trisomy-21 dissociates properties of short- and long-term recognition memory

OpenAIRE

Hall, Jessica H.; Wiseman, Frances K.; Fisher, Elizabeth M.C.; Tybulewicz, Victor L.J.; Harwood, John L.; Good, Mark A.

2016-01-01

The present study examined memory function in Tc1 mice, a transchromosomic model of Down syndrome (DS). Tc1 mice demonstrated an unusual delay-dependent deficit in recognition memory. More specifically, Tc1 mice showed intact immediate (30sec), impaired short-term (10-min) and intact long-term (24-h) memory for objects. A similar pattern was observed for olfactory stimuli, confirming the generality of the pattern across sensory modalities. The specificity of the behavioural deficits in Tc1 mi...

99mTc-HYNIC-derivatized ternary ligand complexes for 99mTc-labeled polypeptides with low in vivo protein binding

International Nuclear Information System (INIS)

Ono, Masahiro; Arano, Yasushi; Mukai, Takahiro; Fujioka, Yasushi; Ogawa, Kazuma; Uehara, Tomoya; Saga, Tsuneo; Konishi, Junji; Saji, Hideo

2001-01-01

6-Hydrazinopyridine-3-carboxylic acid (HYNIC) is a representative agent used to prepare technetium-99m ( 99m Tc)-labeled polypeptides with tricine as a coligand. However, 99m Tc-HYNIC-labeled polypeptides show delayed elimination rates of the radioactivity not only from the blood but also from nontarget tissues such as the liver and kidney. In this study, a preformed chelate of tetrafluorophenol (TFP) active ester of [ 99m Tc](HYNIC)(tricine)(benzoylpyridine: BP) ternary complex was synthesized to prepare 99m Tc-labeled polypeptides with higher stability against exchange reactions with proteins in plasma and lysosomes using the Fab fragment of a monoclonal antibody and galactosyl-neoglycoalbumin (NGA) as model polypeptides. When incubated in plasma, [ 99m Tc](HYNIC-Fab)(tricine)(BP) showed significant reduction of the radioactivity in high molecular weight fractions compared with [ 99m Tc](HYNIC-Fab)(tricine) 2. When injected into mice, [ 99m Tc](HYNIC-NGA)(tricine)(BP) was metabolized to [ 99m Tc](HYNIC-lysine)(tricine)(BP) in the liver with no radioactivity detected in protein-bound fractions in contrast to the observations with [ 99m Tc](HYNIC-NGA)(tricine) 2. In addition, [ 99m Tc](HYNIC-NGA)(tricine)(BP) showed significantly faster elimination rates of the radioactivity from the liver as compared with [ 99m Tc](HYNIC-NGA)(tricine) 2. Similar results were observed with 99m Tc-labeled Fab fragments where [ 99m Tc](HYNIC-Fab)(tricine)(BP) exhibited significantly faster elimination rates of the radioactivity not only from the blood but also from the kidney. These findings indicated that conjugation of [ 99m Tc](HYNIC)(tricine)(BP) ternary ligand complex to polypeptides accelerated elimination rates of the radioactivity from the blood and nontarget tissues due to low binding of the [ 99m Tc](HYNIC)(tricine)(BP) complex with proteins in the blood and in the lysosomes. Such characteristics would render the TFP active ester of [ 99m Tc](HYNIC)(tricine)(BP) complex

Development of methodology for evaluation of 99mTc and 131I incorporated activities during lactation

International Nuclear Information System (INIS)

Santos, L.; Dantas, A.L.A.; Mesquita, S.A.; Oliveira, S.M.V.; Instituto de Radioprotecao e Dosimetria

2012-01-01

Internal contamination of babies may occur for milk ingestion or inhalation of mothers occupationally exposed to ionizing radiation with possible incorporation or mothers submitted to medical exposures during lactation. Radionuclide concentrations in the mother's milk may cause organ absorbed doses in the babies proportionally to the breast volumes. Milk analysis allow to determine activities ingested by the babies by determining the peak of mother's milk considering the decrease of the activity rate and the milk activities drunk at different time intervals. The work had the aim to develop simulators and methodology to evaluate 99m Tc and 131 I in lactation, in the following steps: to prepare standard solution of contaminated milk separately with 99m Tc and 131 I; to build four breast simulators (600 g and 800 g) and respective calibration for two geometries (breast and whole-body) in the Whole-Body Counter Unit in Instituto de Radioprotecao e Dosimetria. The results demonstrated the system efficiency to determine 99m Tc and 131 I activities in breasts during the lactation period. The methodology for positioning in the 'breast geometry' seemed to be more efficient than the 'whole-body geometry' for different breast volumes. The experiment allows achieving better evaluation of internal dosimetry of mothers and their young children. (author)

Localized chemistry of 99Tc in simulated low activity waste glass

Science.gov (United States)

Weaver, Jamie L.

A priority of the United States Department of Energy (DOE) is to dispose of the nuclear waste accumulated in the underground tanks at the Hanford Nuclear Reservation in Richland, WA. Incorporation and stabilization of technetium (99Tc) from these tanks into vitrified waste forms is a concern to the waste glass community and DOE due to 99Tc's long half-life ( 2.13˙105 y), and its high mobility in the subsurface environment under oxidizing conditions. Working in collaboration with researchers at Pacific Northwest National Laboratory (PNNL) and other national laboratories, plans were formulated to obtain first-of-a-kind chemical structure determination of poorly understood and environmentally relevant technetium compounds that relate to the chemistry of the Tc in nuclear waste glasses. Knowledge of the structure and spectral signature of these compounds aid in refining the understanding of 99Tc incorporation into and release from oxide based waste glass. In this research a first-of-its kind mechanism for the behavior of 99Tc during vitrification is presented, and the structural role of Tc(VII) and (IV) in borosilicate waste glasses is readdressed.

A novel phthalimide derivative, TC11, has preclinical effects on high-risk myeloma cells and osteoclasts.

Directory of Open Access Journals (Sweden)

Maiko Matsushita

Full Text Available Despite the recent advances in the treatment of multiple myeloma (MM, MM patients with high-risk cytogenetic changes such as t(4;14 translocation or deletion of chromosome 17 still have extremely poor prognoses. With the goal of helping these high-risk MM patients, we previously developed a novel phthalimide derivative, TC11. Here we report the further characterization of TC11 including anti-myeloma effects in vitro and in vivo, a pharmacokinetic study in mice, and anti-osteoclastogenic activity. Intraperitoneal injections of TC11 significantly delayed the growth of subcutaneous tumors in human myeloma-bearing SCID mice. Immunohistochemical analyses showed that TC11 induced apoptosis of MM cells in vivo. In the pharmacokinetic analyses, the Cmax was 2.1 μM at 1 h after the injection of TC11, with 1.2 h as the half-life. TC11 significantly inhibited the differentiation and function of tartrate-resistant acid phosphatase (TRAP-positive multinucleated osteoclasts in mouse osteoclast cultures using M-CSF and RANKL. We also revealed that TC11 induced the apoptosis of myeloma cells accompanied by α-tubulin fragmentation. In addition, TC11 and lenalidomide, another phthalimide derivative, directly bound to nucleophosmin 1 (NPM1, whose role in MM is unknown. Thus, through multiple molecular interactions, TC11 is a potentially effective drug for high-risk MM patients with bone lesions. The present results suggest the possibility of the further development of novel thalidomide derivatives by drug designing.

APEX (Air Pollution Exercise) Volume 21: Legal References: Air Pollution Control Regulations.

Science.gov (United States)

Environmental Protection Agency, Research Triangle Park, NC. Office of Manpower Development.

The Legal References: Air Pollution Control Regulations Manual is the last in a set of 21 manuals (AA 001 009-001 029) used in APEX (Air Pollution Exercise), a computerized college and professional level "real world" game simulation of a community with urban and rural problems, industrial activities, and air pollution difficulties. The manual…

Determination of 99Mo in 99mTc eluates used in nuclear medicine centers in Rio de Janeiro

International Nuclear Information System (INIS)

Ribeiro, Bianca da S.; Souza, Raphael S.S.; Lucena, Eder A.; Dantas, Ana Leticia A.; Dantas, Bernardo M.

2009-01-01

99m Tc is used in nuclear medicine for image diagnoses with SPECT. It is obtained from the elution of molybdenum-99/technetium-99m ( 99 Mo/ 99m Tc) generators. During the elution, 99 Mo can detach from the column, passing through the filter and mixing in the solution of pertechnetate eluate and becoming a radionuclidic impurity. The presence of molybdenum in the radiopharmaceutical solution imparts an unnecessary radiation dose to the patient, since its half-life is relatively long (66 hours) and it emits beta particles and high-energy photons of (740 keV). A parameter that indicates the quality of the eluates is the radionuclidic purity, the MBT (molybdenum break through), defined as the ratio between 99 Mo and 99m Tc activities in the eluate. The American and the European Pharmacopoeias restrict 99 Mo content to respectively 0.015% and 0.1% activity ratio 99 Mo/ 99m Tc at the time of the administration to the patient. In Brazil, this parameter is not controlled by official regulations. The objective of this work is to determine the presence of 99 Mo in the eluates used in nuclear medicine centers (NMC). The activity measurements of 99 Mo were performed with a NaI(Tl)8''x4'' scintillation detector installed in the IRD whole body counter. The activity of 99m Tc was measured in the NMC where the eluates were collected and, using the established calculations, it was determined the activity ratio 99 Mo/ 99m Tc. The eluate samples were kindly supplied by the participating NMC of Rio de Janeiro. All measurements indicated the presence of 99 Mo. It is concluded that the technique is sensitive to detect 99 Mo in 99m Tc eluates and permits to verify the quality of the generators used in NMC evaluated in this study. (author)

Comparative biological evaluation between 99mTc tricarbonyl and 99mTc-Sn(II) levosalbutamol as a β2-adrenoceptor agonist

International Nuclear Information System (INIS)

Sanad, Mahmoud H.; Borai, Emad H.

2015-01-01

This study describes the comparison between 99m Tc-tricarbonyl and 99m Tc-Sn (II) levosalbutamol as a β 2 -adrenoceptors radiopharmaceutical and evaluation of their different biological characteristics using experimental animals. Levosalbutamol was labeled firstly with 99m Tc in the presence of SnCl 2 . 2H 2 O as a reducing agent under the optimum conditions: pH 8, 50 μg SnCl 2 . 2H 2 O, room temperature, 40 μg levosalbutamol and 30 min reaction time to give a maximum radiochemical yield of 98 ± 0.1%. The obtained 99m Tc-levosalbutamol was stable for a time up to 8 h. Secondly, 99m Tc-tricarbonyl ([ 99m Tc(CO) 3 (H 2 O) 3 ] + ) levosalbutamol was prepare under 30 min heating at 100 C. Labeling yield and stability were analyzed by high performance liquid chromatography (labeling yield >99% and stability for 8 h). Biodistribution investigation showed that, the maximum uptake ratio of the 99m Tc-levosalbutamol ( 99m Tc-Lev) between lung and heart was 2.34 ± 0.62 % of the injected activity/g tissue organ, at 30 min post-injection. But in case of 99m Tc-tricarbonyl levosalbutamol ( 99m Tc-tricarbonyl Lev) the maximum uptake ratio was 3.6 ± 0.11 of the injected activity/g tissue organ, at 30 min post-injection. This indicates that 99m Tc-tricarbonyl levosalbutamol was more selective for lung β 2 -adrenoceptors than 99m Tc-levosalbutamol. These results introduce 99m Tc-tricarbonyl levosalbutamol as a novel potential radiopharmaceutical for lung imaging.

Significance of delayed /sup 99m/Tc-PMT scintigraphy in diagnosis of hepatocellular carcinoma. Comparison between /sup 99m/Tc-PMT and /sup 67/Ga-citrate scintigraphy

Energy Technology Data Exchange (ETDEWEB)

Hasegawa, Yoshihisa; Nakano, Shunichi; Hashizume, Terumi and others

1985-03-01

The usefulness of delayed hepatobiliary imaging with /sup 99m/Tc-PMT in diagnosis of hepatocellular carcinoma was studied in 30 patients with histologically verified hepatocellular carcinoma. Of 30 patients, delayed /sup 99m/Tc-PMT images showed 13 patients (43 %) of increased radioactivity and 4 (13 %) of equilibrated radioactivity in carcinoma as compared with that in the surrounding normal liver tissues. Furthermore, 3 of 6 patients who showed no filling defects in /sup 99m/Tc-Sn colloid liver images, showed increased uptake of radioactivity in carcinoma in delayed /sup 99m/Tc-PMT images. These results suggest that the complementary use of delayed /sup 99m/Tc-PMT imaging to /sup 99m/Tc-Sn colloid liver imaging is useful for detecting hepatoma lesions. The hepatic lesions were positively visualized on /sup 99m/Tc-PMT and/or /sup 67/Ga-citrate images in 21 (70 %) of 30 patients. These results indicate that use of delayed /sup 99m/Tc-PMT and /sup 67/Ga-citrate imaging in combination is useful for positive visualization of hepatocellular carcinoma.

Low-activity 124I-PET/low-dose CT versus 99mTc-pertechnetate planar scintigraphy or 99mTc-pertechnetate single-photon emission computed tomography of the thyroid: a pilot comparison.

Science.gov (United States)

Darr, Andreas M; Opfermann, Thomas; Niksch, Tobias; Driesch, Dominik; Marlowe, Robert J; Freesmeyer, Martin

2013-10-01

The standard thyroid functional imaging method, 99mTc-pertechnetate (99mTc-PT) planar scintigraphy, has technical drawbacks decreasing its sensitivity in detecting nodules or anatomical pathology. 124I-PET, lacking these disadvantages and allowing simultaneous CT, may have greater sensitivity for these purposes. We performed a blinded pilot comparison of 124I-PET(/CT) versus 99mTc-PT planar scintigraphy or its cross-sectional enhancement, 99mTc-PT single-photon emission CT (SPECT), in characterizing the thyroid gland with benign disease. Twenty-one consecutive adults with goiter underwent low-activity (1 MBq/0.027 mCi) 124I-PET/low-dose (30 mAs) CT, 99mTc-PT planar scintigraphy, and 99mTc-PT-SPECT. Endpoints included the numbers of “hot spots” with/without central photopenia and “cold spots” detected, the proportion of these lesions with morphological correlates, the mean volume and diameter of visualized nodules, and the number of cases of lobus pyramidalis or retrosternal thyroid tissue identified. 124I-PET detected significantly more “hot spots” with/without central photopenia (P < 0.001), significantly more nodules (P < 0.001), and more “cold spots” than did 99mTc-PT planar scintigraphy or 99mTc-PT-SPECT, including all lesions seen on the 99mTc-PT modalities. Ultrasonographic correlates were found for all nodules visualized on all 3 modalities and 92.5% of nodules seen only on 124I-PET. Nodules discernible only on 124I-PET had significantly smaller mean volume or diameter (P < 0.001) than did those visualized on 99mTc-PT planar scintigraphy or 99mTc-PT-SPECT. 124I-PET(/CT) identified significantly more patients with a lobus pyramidalis (P < 0.001) or retrosternal thyroid tissue (P < 0.05). 124I-PET(/CT) may provide superior imaging of benign thyroid disease compared to planar or cross-sectional 99mTc-PT scintigraphy.

Cellular uptake of 99mTcN-NOET in human leukaemic HL-60 cells is related to calcium channel activation and cell proliferation

International Nuclear Information System (INIS)

Guillermet, Stephanie; Vuillez, Jean-Philippe; Caravel, Jean-Pierre; Marti-Batlle, Daniele; Fagret, Daniel; Fontaine, Eric; Pasqualini, Roberto

2006-01-01

A major goal of nuclear oncology is the development of new radiolabelled tracers as proliferation markers. Intracellular calcium waves play a fundamental role in the course of the cell cycle. These waves occur in non-excitable tumour cells via store-operated calcium channels (SOCCs). Bis(N-ethoxy, N-ethyldithiocarbamato) nitrido technetium (V)-99m ( 99m TcN-NOET) has been shown to interact with L-type voltage-operated calcium channels (VOCCs) in cultured cardiomyocytes. Considering the analogy between VOCCs and SOCCs, we sought to determine whether 99m TcN-NOET also binds to activated SOCCs in tumour cells in order to clarify the potential value of this tracer as a proliferation marker. Uptake kinetics of 99m TcN-NOET were measured in human leukaemic HL-60 cells over 60 min and the effect of several calcium channel modulators on 1-min tracer uptake was studied. The uptake kinetics of 99m TcN-NOET were compared both with the variations of cytosolic free calcium concentration measured by indo-1/AM and with the variations in the SG 2 M cellular proliferation index. All calcium channel inhibitors significantly decreased the cellular uptake of 99m TcN-NOET whereas the activator thapsigargin induced a significant 10% increase. In parallel, SOCC activation by thapsigargin, as measured using the indo-1/AM probe, was inhibited by nicardipine. These results indicate that the uptake of 99m TcN-NOET is related to the activation of SOCCs. Finally, a correlation was observed between the tracer uptake and variations in the proliferation index SG 2 M. The uptake of 99m TcN-NOET seems to be related to SOCC activation and to cell proliferation in HL-60 cells. These results indicate that 99m TcN-NOET might be a marker of cell proliferation. (orig.)

Tc-knirps plays different roles in the specification of antennal and mandibular parasegment boundaries and is regulated by a pair-rule gene in the beetle Tribolium castaneum

Science.gov (United States)

2013-01-01

regulated by a pair rule gene adds to the view that the segmentation gene hierarchies differ between Tribolium and Drosophila upstream of the pair rule gene level. In Tribolium, as in Drosophila, head and trunk segmentation gene networks cooperate to pattern the mandibular segment, albeit involving Tc-kni as novel component. PMID:23777260

99mTc-EDDA/HYNIC-octreotate in detection of atypical bronchial carcinoid.

Science.gov (United States)

Hubalewska-Dydejczyk, A; Fröss-Baron, K; Gołkowski, F; Sowa-Staszczak, A; Mikołajczak, R; Huszno, B

2007-01-01

Pulmonary carcinoids cause serious difficulties in imaging diagnostics in all stages of the disease. SRS holds great promise for detecting occult primary tu and metastatic lesions. (99m)Tc-EDDA/HYNIC-octreotate, a new scintigraphic agent, should significantly improve sensitivity of the diagnostics of carcinoids due to better affinity to SSR2 than (111)In-Octreoscan and the higher count rate obtained from (99m)Tc over (111)In. We present a case of a 40-year-old women operated on because of lung carcinoid tumour in 2002. The symptoms did not resolve after the operation and 5-OHIAA was still elevated. The thorax spiral CT revealed the focal lesion beneath carina. (111)In-Octreoscan and (99m)Tc-EDDA/HYNIC-octreotate SRS revealed two focal lesions in the mediastinum. (99m)Tc-EDDA/HYNIC-octreotate detected two additional lesions in the lower part of the right lung. Target/non-target count ratios of the lesions were as follows: (99m)Tc-EDDA/HYNIC-octreotate scans - 2,9, (111)In-Octreoscan- 2,1. PET-FDG examination revealed no pathology. Owing to severe bone pains and carcinoid symptoms the patient was referred for the 90Y-DOTA-octreotate treatment. SRS with a new 99mTc marked somatostatin analogue - octreotate allows for a more sensitive detection of metastatic leasions in carcinoid tumours. The usefulness of 18F-FDG PET, widely used as a powerful imaging technique in clinical oncology, is limited in detection of carcinoid tumours due to the low proliferative activity.

RILEM TC ISR Summer 2015 Activity Report

Energy Technology Data Exchange (ETDEWEB)

Le Pape, Yann [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States)

2015-08-01

With aging infrastructures, instances of Alkali Silica Reaction (ASR) and Delayed Ettringite Formation (DEF), broadly covered under the term Internal Swelling Reaction (ISR), are increasingly being detected. They have been observed in bridges, dams, and most recently in nuclear power plants. Concrete swelling may result in bridge partial failure, dams with structural cracks and misaligned turbine shafts, and locked slice gates. For nuclear reactors micro-cracks may cause increased gas permeability which will jeopardize the containment integrity and may decrease the residual structural resistance under accidental loading. This TC, which limits its activity to structures with known expansive concrete, seeks to address two complementary but fundamental questions: a) What is the kinetics of the reaction and b) How would it affect the integrity of the structure (serviceability and strength) and thus establish a science based prognostic to the structure owner.

[99mTc]MAG3-mannosyl-dextran: a receptor-binding radiopharmaceutical for sentinel node detection

International Nuclear Information System (INIS)

Vera, David R.; Wallace, Anne M.; Hoh, Carl K.

2001-01-01

Technetium-99m-labeled benzoyl-mercaptoacetylglycylglycyl-glycine-mannosyl-dextran ([ 99m Tc]MAG 3 -mannosyl-dextran) is a receptor-binding radiotracer that binds to mannose-binding protein, a receptor expressed by reticuloendothelial tissue. This agent is composed of a 10.5-kilodalton molecule of dextran and multiple units of mannose, and benzoyl-mercaptoacetylglycylglycyl-glycine (BzMAG 3 ). The tetraflorophenol-activated ester of BzMAG 3 and the imidate of thiomannose were used to covalently attach BzMAG 3 and mannose to an amino-terminated conjugate of dextran. This yielded a 19-kilodalton macromolecule consisting of 3 BzMAG 3 and 21 mannose units per dextran. Dynamic light scattering was used to measure a mean diameter of 5.5 nanometers for BzMAG 3 -mannosyl-dextran and 0.28 microns for filtered Tc-99m sulfur colloid. A preliminary sentinel node detection study employing right fore and hind footpad injections of [ 99m Tc]MAG 3 -mannosyl-dextran and left fore and hind footpad injections of filtered Tc-99m sulfur colloid demonstrated greater sentinel lymph node uptake by the receptor-binding agent

{sup 99m}Tc-rituximab radiolabelled by photo-activation: a new non-Hodgkin's lymphoma imaging agent

Energy Technology Data Exchange (ETDEWEB)

Gmeiner Stopar, T.; Fettich, J.; Hojker, S. [University Medical Centre Ljubljana, Department for Nuclear Medicine, Ljubljana (Slovenia); Mlinaric-Rascan, I. [University of Ljubljana, Faculty of Pharmacy, Ljubljana (Slovenia); Mather, S.J. [St Bartholomew' s Hospital, Cancer Research UK, Department Nuclear Medicine, London (United Kingdom)

2006-01-01

Rituximab was the first chimeric monoclonal antibody to be approved for treatment of indolent B-cell non-Hodgkin's lymphoma (NHL). It is directed against the CD20 antigen, which is expressed by 95% of B-cell NHLs. The aim of this study was to explore the possibility of radiolabelling rituximab with {sup 99m}Tc for use as an imaging agent in NHL for early detection, staging, remission assessment, monitoring for metastatic spread and tumour recurrence, and assessment of CD20 expression prior to (radio)immunotherapy. Rituximab was purified from Mabthera solution (Roche), photo-activated at 302 nm by UV irradiation and radiolabelled with {sup 99m}Tc. The effectiveness of the labelling method was evaluated by determination of the number of free thiol groups per photoreduced antibody, radiochemical purity and in vitro stability of {sup 99m}Tc-rituximab. On average, 4.4 free thiol groups per photoreduced antibody were determined. Radiolabelling yields greater than 95% were routinely observed after storage of the photo-activated antibody at -80 C for 195 days. The direct binding assay showed preserved ability of {sup 99m}Tc-rituximab to bind to CD20, with an average immunoreactive fraction of 93.3%. The internalisation rate was proven to be low, with only 5.3% of bound {sup 99m}Tc-rituximab being internalised over 4 h at 37 C. Our results demonstrate that {sup 99m}Tc-rituximab of high radiochemical purity and with preserved binding affinity for the antigen can be prepared by photoreduction and that the method shows good reproducibility. {sup 99m}Tc-rituximab will be further explored as an imaging agent applicable in NHL for the purposes mentioned above. (orig.)

Evaluation of the gravimetric tetraphenylarsonium method for the determination of Tc(VII)

International Nuclear Information System (INIS)

Pacer, R.A.

1980-01-01

Solubility losses in the gravimetric tetraphenylarsonium method for determining pertechnetate have been evaluated. Liquid scintillation counting was used to measure the β - activity of 99 Tc in the filtrate, and indicated solubility losses of about 1% in analyses yielding 40 to 50 mg of precipitate. The solubility product of (C 6 H 5 ) 4 AsTcO 4 is estimated to be (8.6 +- 0.2) x 10 -10 at room temperature (24 to 25 0 ), and Ksub(sp) for (C 6 H 5 ) 4 AsReO 4 at approximately 21 to 23 0 is estimated at (2.6 +- 0.3) x 10 -9 . Both values are satisfactory for gravimetric purposes, but to keep solubility losses within 1% at least 40 mg of (C 6 H 5 ) 4 AsTcO 4 or 80 mg of (C 6 H 5 ) 4 AsReO 4 should be obtained (assuming 20 ml of solution, 20 to 30% excess of precipitant, and 6 or 7 washes with 5-ml portions of distilled water). (author)

Towards kit formulation of 99mTc labelled somatostatin receptor binding peptides of high specific activity for tumour localization

International Nuclear Information System (INIS)

Behe, M.; Powell, P.; Maecke, H.R.

2001-01-01

The project aimed to develop 99m Tc octreotide analogue for use in nuclear oncology. Several attempts to label SRIF analogues with 99m Tc have used a direct labelling approach but, for this project, HYNIC was chosen as a technetium ligand. A comparison of two different SRIF analogues designed for high specific activity labelling with 99m Tc was done. HYNIC-Octreotide and HYNIC-TOC were prepared and a kit formulation that can be labelled conveniently is currently being studied in a clinical setting. (author)

Skeletal affinity of Tc(V)-DMS is bone cell mediated and pH dependent.

Science.gov (United States)

Horiuchi-Suzuki, Kazuko; Konno, Aya; Ueda, Mayumi; Fukuda, Yoko; Nishio, Saori; Hashimoto, Kazuyuki; Saji, Hideo

2004-03-01

In spite of recent advances in bone cellular and molecular biology, there is still a poor correlation between these parameters and data obtained from bone scintigraphy. Diphosphonate derivatives radiolabelled with technetium-99m (Tc-BPs) have long been recognised as bone-seeking agents with an affinity for areas of active mineralisation. However, during clinical trials with a pH-sensitive tumour agent, the pentavalent technetium complex of dimercaptosuccinic acid [Tc(V)-DMS] showed a noticeable osteotropic character only in bone pathologies (bone metastases, Paget's diseases) and lacked accumulation in normal mature bone. To decipher the osteotropic character of Tc(V)-DMS, a study at the cellular level was considered necessary. Moreover, to learn more about the role of Tc bone agents, acid-base regulation by bone tissue or cells was studied. First, biological parameters in body fluid were measured under systemic acidosis, induced by glucose administration, in normal and Ehrlich ascites tumour (EAT)-bearing mice. Then, in vivo biodistribution studies using Tc(V)-DMS or a conventional Tc-BP agent were carried out. The effect of glucose-mediated acidification on the skeletal distribution of the Tc agents in the mice provided valuable hints regarding the differential mediation of bone cells in skeletal tissue affinity for the agents. Thereafter, in vitro studies on osteoblast and osteoclast cells were performed and the comparative affinity of Tc(V)-DMS and Tc-BP was screened under diverse acidification conditions. Moreover, studies were also carried out on acid-base parameters related to the cellular uptake mechanism. Very specific pH-sensitive Tc(V)-DMS accumulation only in the osteoclastic system was detected, and use of Tc(V)-DMS in the differential detection of osteoblastic and osteoclastic metastases is discussed.

Solubility of Tc(IV) oxides

International Nuclear Information System (INIS)

Liu, D.J.; Fan, X.H.

2005-01-01

Full text of publication follows: The deep geological disposal of the high level radioactive wastes is expected to be a safer disposal method in most countries. The long-lived fission product 99 Tc is present in large quantities in nuclear wastes and its chemical behavior in aqueous solution is of considerable interest. Under the reducing conditions, expected to exist in a deep geological repository, it is generally predicted that technetium will be present as TcO 2 .nH 2 O. The solubility of Tc(IV) is used as a source term in performance assessment of radioactive waste repository. Technetium oxide was prepared by reduction of a technetate solution with Sn 2+ . The solubility of Tc(IV) oxide has been determined in simulated groundwater and re-distilled water under aerobic and anaerobic conditions. The effects of pH and CO 3 2- concentration of solution on solubility of Tc(IV) oxide were studied. The concentration of total technetium and Tc(IV) species in the solutions were periodically determined by separating the oxidized and reduced technetium species using a solvent extraction procedure and counting the beta activity of the 99 Tc with a liquid scintillation counter. The experimental results show that the rate of oxidation of Tc(IV) in simulated groundwater and re-distilled water is about (1.49∼1.86) x 10 -9 mol/(L.d) under aerobic conditions, but Tc(IV) in simulated groundwater and re-distilled water is not oxidized under anaerobic conditions. Under aerobic or anaerobic conditions the solubility of Tc(IV) oxide in simulated groundwater and re-distilled water is equal on the whole after centrifugation or ultrafiltration. The solubility of Tc(IV) oxide decreases with the increase of pH at pH 10 and is pH independent in the range 2 -8 to 10 -9 mol/L at 2 3 2- concentration. These data could be used to estimate the Tc(IV) solubility for cases where solubility limits transport of technetium in reducing environments of high-level waste repositories. (authors)

Imaging human melanoma using a novel Tc-99m-labeled lactam bridge-cyclized alpha-MSH peptide.

Science.gov (United States)

Liu, Liqin; Xu, Jingli; Yang, Jianquan; Feng, Changjian; Miao, Yubin

2016-10-01

In this study, the human melanoma targeting property of (99m)Tc(EDDA)-HYNIC-AocNle-CycMSHhex {hydrazinonicotinamide-8-aminooctanoic acid-Nle-c[Asp-His-DPhe-Arg-Trp-Lys]-CONH2} was determined in M21 human melanoma-xenografts to demonstrate its potential for human melanoma imaging. The IC50 value of HYNIC-AocNle-CycMSHhex was 0.48±0.01nM in M21 human melanoma cells (1281receptors/cell). The M21 human melanoma uptake of (99m)Tc(EDDA)-HYNIC-AocNle-CycMSHhex was 4.03±1.25, 3.26±1.23 and 3.36±1.48%ID/g at 0.5, 2 and 4h post-injection, respectively. Approximately 92% of injected dose cleared out the body via urinary system at 2h post-injection. (99m)Tc(EDDA)-HYNIC-AocNle-CycMSHhex showed high tumor/blood, tumor/muscle and tumor/skin uptake ratios after 2h post-injection. The M21 human melanoma-xenografted tumor lesions were clearly visualized by SPECT/CT using (99m)Tc(EDDA)-HYNIC-AocNle-CycMSHhex as an imaging probe at 2h post-injection. Overall, (99m)Tc(EDDA)-HYNIC-AocNle-CycMSHhex exhibited favorable human melanoma imaging property, highlighting its potential as an imaging probe for human metastatic melanoma detection. Copyright © 2016 Elsevier Ltd. All rights reserved.

Scintigraphic findings on 99mTc-MDP, 99mTc-sestamibi and 99mTc-HMPAO images in Gaucher's disease

International Nuclear Information System (INIS)

Mariani, G.; Molea, N.; La Civita, L.; Porciello, G.; Lazzeri, E.; Ferri, C.

1996-01-01

We report here on the use of the lipophilic cationic complex technetium-99m sestamibi ( 99m Tc-MIBI), employed as an indicator of increased cellular density and metabolic activity, to evaluate Gaucher cell infiltrates in the bone marrow; 99m Tc-hexametazime ( 99m Tc-HMPAO) was also employed, as a pure indicator of lipidic infiltration in the bone marrow. A 67-year-old patient with known type 1 Gaucher's disease presented with a painful left hip and knee and difficulty in gait subsequent to traumatic fracture of the left femoral neck that had required implant of a fixation screw-plaque. Bone scan with 99m Tc-methylene diphosphonate revealed reduced uptake at the distal metaphyseal-epiphyseal femoral region. In addition, whole-body maps and spot-view acquisitions of the thighs and legs were recorded at both 30 min and 2.5 h after the injection of 99m Tc-MIBI: the scintigraphic pattern clearly showed increased uptake at several sites involved by Gaucher deposits in the bone marrow (both knees, with variable intensity in different areas), matching the bone changes detected by conventional x-ray. The target to non-target ratios slowly decreased with time, from an average value of 2.25 in the early scan to an average value of 2 in the delayed scan. The lipid-soluble agent 99m Tc-HMPAO exhibited a superimposable scintigraphic pattern of accumulation at the involved sites, though with lower target to non-target ratios (1.27-1.48). The results obtained in this patient suggest a potential role of 99m Tc-MIBI in the scintigraphic evaluation of Gaucher's lipid deposits in the bone marrow. If the results are confirmed in other patients, this radiopharmaceutical would offer clear advantages over 133 Xe because of its wider availability and greater practicality (i.v. administration of 99m Tc-MIBI versus inhalation of 133 Xe, and use of a single gamma camera instead of two as with 133 Xe). (orig.). With 3 figs

Comparison of activity measurements of 131I and 99mTc radionuclides administered in nuclear medicine services of Porto Alegre

International Nuclear Information System (INIS)

Alabarse, Frederico Gil.; Santos, Carlos Eduardo Lima dos

2005-01-01

A programme for the comparison of activity measurements of radionuclides administered to patients in Nuclear Medicine Services, for the purpose of diagnosis or therapy, is being conducted under the coordination of the Radioprotection and Dosimetry Institute of the Brazilian Nuclear Energy Commission, IRD/CNEN. In the present work, measurements of the activity of samples of 131 I and 99 mTc were conducted in the dose calibrators of the Nuclear Medicine Services of the city of Porto Alegre, in the period from June to September 2004. The results were analysed to evaluate the compliance with the Brazilian regulation and were also compared to data available in the literature for the cities of Rio de Janeiro and Brasilia. The performance of the activity meters in Porto Alegre is shown to be very good, which contributes to the radiological protection of patients submitted to diagnosis or therapy with radiopharmaceuticals. (author)

Technetium-99 in ''instant'' sup(99m)Tc-pertechnetate

International Nuclear Information System (INIS)

Mattsson, S.

1978-01-01

The 99 Tc-content in sup(99m)Tc-pertechnetate separated from 99 Mo by distillation or extraction has been studied with a plastic scintillation detector. The identification of the measured activity was achieved by beta-spectrometry, chemical separation and half-life studies. The frequency distribution of the sup(99)Tc/sup(99m)Tc-ratios in the different samples was observed to be log-normal. The most likely activity ratio was 0.4x10 -6 , the maximum value being 5x10 -6 . The specific activity of ''instant'' pertechnetate is approximately a factor of 60 lower than that normally recorded in pertechnetate derived from daily eluted column generators. The low specific activity of ''instant'' pertechnetate is primarily explained by the long time between separation and usage and secondly by the low yield of Tc in the distillation and extraction processes. In several of the ''instant'' pertechnetate solutions the carrier concentration exceeded the reductive capacity of the stannous ions in ''kits'' with small amounts of Sn(II) in usable form. (T.G.)

99mTc-MAG3: can it be a viable alternative to 99mTc-DTPA ?

International Nuclear Information System (INIS)

Bal, C.S.; Padhy, A.K.; Nair, R.; Gopinath, P.G.

1991-01-01

The purpose of this study was to assess the potentials of 99m Tc MAG 3 to replace universally used 99m Tc-DTPA as a routine renal agent. Five patients with different nephrological problems were first studied with 99m Tc MAG 3 and then reinvestigated with 99m Tc-DTPA two to seven days later. Renal MAG 3 gamma camera images were found to be almost identical with those of 99m Tc-DTPA images except high hepatic and splenic uptake of the former compound in four out of five patients (80%) irrespective of kidney function. MAG 3 and DTPA renograms showed identical differential renal uptake function (r=0.87) with slightly higher uptake in right kidneys. Time to reach the peak correlated well (r=0.91). Time to reach half maximum renal activity was also found to be almost identical (r=0.97) for MAG 3 and DTPA. It was felt that the age old 99m Tc-DTPA is as good a compound as 99m Tc MAG 3 with regard to imaging and assessment of renal uptake, drainage and differential renal functions. 99m Tc-DTPA is much cheaper, readily available in India and stable to suit the logistics in a busy nuclear medicine department for routine renography. (author). 10 refs., 2 figs., 3 tabs

Presentation of test cases TC-2A, TC-2B, TC-2C, TC-2D - Twodimensional, incompressible, wall flows with separation

DEFF Research Database (Denmark)

Scheel Larsen, Poul

1988-01-01

The four test cases comprise the backfacing step at high Re-number (TC-2A) and low Re-number (TC-2B), a low Re-number boundary layer flow past a thin obstacle, fence-on-wall (TC-2C), and a high Re-number developed channel flow past a squareobstacle (TC-2D). Geometry, test conditions and available...

93Tc and sup(93m)Tc gamma spectra

International Nuclear Information System (INIS)

Podkopaev, Yu.N.; Zarubin, P.P.; Kobelev, V.F.; Padalko, V.Yu.; Khrisanfov, Yu.V.

1977-01-01

The sup(93,93m)Tc decay was studied. The spectra of γ-rays accompanying the decay of this nuclide were studied. 93 Tc and sup(93m)Tc were obtained in the (dn)-reaction on 92 Mo. To ensure a more reliable identification of γ-rays, the isotopic composition of the targets, the bombardment time, the energy of the bombarding deuterons (5-12 MeV) and the spectrum processing program were varied. The energies and relative intensities of the γ-rays of the 93 Tc and sup(93m)Tc decay are listed in tables together with data of other investigatxons. The results obtained largely confirm the known data. Four new transitions were added in the sup(93m)Tc spectrum namely 1046.8, 2011.8, 2182.0, and 2861.5 keV. The 2739.0 keV transition was eliminated from the 93 Tc spectrum. The appropriate changes and additions were made in the 93 Tc decay scheme, and three new levels were introduced: 2479.0, 2821.7, and 3025.8 keV. The values of log ft of some levels of 93 Tc were estimated

The S100P/RAGE signaling pathway regulates expression of microRNA-21 in colon cancer cells.

Science.gov (United States)

Mercado-Pimentel, Melania E; Onyeagucha, Benjamin C; Li, Qing; Pimentel, Angel C; Jandova, Jana; Nelson, Mark A

2015-08-19

S100P signaling through the receptor for advanced glycation end-products (RAGE) contributes to colon cancer invasion and metastasis, but the mechanistic features of this process are obscure. Here, we investigate whether activation of S100P/RAGE signaling regulates oncogenic microRNA-21 (miR-21). We show that exogenous S100P up-regulates miR-21 levels in human colon cancer cells, whereas knockdown of S100P results in a decrease of miR-21. Furthermore, blockage of RAGE with anti-RAGE antibody suppresses S100P induction of miR-21. In addition, we found that S100P induction of miR-21 expression involves ERK and is suppressed by the MEK inhibitor U0126. Also, S100P treatment stimulates the enrichment of c-Fos, and AP-1 family members, at the miR-21 gene promoter. Copyright © 2015 Federation of European Biochemical Societies. Published by Elsevier B.V. All rights reserved.

The role of Tc-99m IDA hepatobiliary and Tc-99m colloid hepatic imaging in primary biliary cirrhosis

International Nuclear Information System (INIS)

Aburano, T.; Yokoyama, K.; Shuke, N.; Kinuya, S.; Takayama, T.; Tonami, N.; Hisada, K.

1991-01-01

To assess the presence of primary biliary cirrhosis, 15 patients at various histopathologic stages were studied by Tc-99m IDA hepatobiliary and/or Tc-99m colloid hepatic imaging. In the earlier stages (I and II), seven of eight patients (88%) showed uniform hepatic retention of Tc-99m IDA. Of seven patients in the same stage, however, four (57%) showed no abnormality on Tc-99m colliod imaging. In three of these four negative patients (75%), uniform hepatic retention of Tc-99m IDA was noted. In the later stages (III and IV), all seven patients showed decreased clearance with or without delayed tracer appearance in the intestine and prominent hepatic retention on Tc-99m IDA imaging; with Tc-99m colloid imaging there was enlargement of the spleen and increased activity in the spleen and bone marrow. Thus, Tc-99m IDA imaging is considered to be more useful in revealing this functional disorder at the earlier stage of primary biliary cirrhosis and in evaluating progression from an earlier to a later stage of disease. Tc-99m colloid imaging also effectively evaluated progression

Biokinetics and dosimetry of a hybrid formulation of {sup 9{sup m}}Tc-BN and {sup 99m}Tc-RGD{sub 2} starting from optic images in a murine model; Biocinetica y dosimetria de una formulacion hibrida de {sup 99m}Tc-BN y {sup 99m}Tc-RGD{sub 2} a partir de imagenes opticas en un modelo murino

Energy Technology Data Exchange (ETDEWEB)

Cornejo A, L. G.

2015-07-01

This work has the purpose of evaluate the biokinetics and absorbed dose of radiation of hybrid formulation {sup 99m}Tc-BN /{sup 99m}Tc-RGD{sub 2} in a murine model by optical imaging techniques using the multimodal preclinical in vivo image system Xtreme. The used method were the {sup 99m}Tc-BN, {sup 99m}Tc-RGD{sub 2} and {sup 99m}Tc-BN/{sup 99m}Tc-RGD{sub 2} formulas, with specific recognition for GRPr and the integrin s α(v)β(3) and α(v)β(5) respectively, was injected in the vein tail of three nude mousses with induce breast cancer tumors (cell line T-47-D), by the preclinical multimodal imaging system Xtreme (Bruker), optical images in different times was acquired (5, 10, 20 min, 2 and 24 h), using Images Processing Toolbox of MATLAB these images was transform from RGB format to gray scales and sectioned in five independent images corresponding to heart, kidneys, bladder and tumor areas. The intensity of each images was computed in counts per pixel, then those intensities was corrected for background, attenuation and scattering, using different factors for each phenomena previously calculated. Finally the activity values quantified vs time was fitted into a biokinetic model to obtain the disintegrations number and cumulate activities in each organ. With these data the radiation absorbed dose were calculated using MIRD methodology. Results: The number of disintegration and absorbed dose calculated in MBq h/MBq and mGy/MBq, of injected mouse with the {sup 99m}Tc-BN/{sup 99m}Tc-RGD{sub 2} formulation, was: 0.035 ± 0.65 E-02, 0.25 x 10{sub -5} ± 0.46 E-07; 0.393 ± 0.51 E-1, 2.85 E-05 ± 3.7 E-06; 0.306 ± 0.21 E-01, 2.11 E-05 ± 1.45 E-06 and 0.151 ± 0.19 E-01, 1.09 E-05 ± 1.42 E-06 , in heart, kidneys, bladder and tumor, respectively. The number of disintegration obtained in kidneys is comparable to those reported for Trinidad B. 2014 Conclusions: Our results demonstrated that using optical images and a code for image analyses development in MATLAB, could

Wedelolactone Regulates Lipid Metabolism and Improves Hepatic Steatosis Partly by AMPK Activation and Up-Regulation of Expression of PPARα/LPL and LDLR.

Directory of Open Access Journals (Sweden)

Yun Zhao

Full Text Available Hyperlipidemia is considered one of the greatest risk factors of cardiovascular diseases. We investigated the anti-hyperlipidemic effect and the underlying mechanism of wedelolactone, a plant-derived coumestan, in HepG2 cells and high-fat diet (HFD-induced hyperlipidemic hamsters. We showed that in cultured HepG2 cells, wedelolactone up-regulated protein levels of adenosine monophosphate activated protein kinase (AMPK and peroxisome proliferator-activated receptor-alpha (PPARα as well as the gene expression of AMPK, PPARα, lipoprotein lipase (LPL, and the low-density lipoprotein receptor (LDLR. Meanwhile, administration of wedelolactone for 4 weeks decreased the lipid profiles of plasma and liver in HFD-induced hyperlipidemic hamsters, including total cholesterol (TC, triglycerides (TG, and low-density lipoprotein-cholesterol (LDL-C. The activation of AMPK and up-regulation of PPARα was also observed with wedelolactone treatment. Furthermore, wedelolactone also increased the activities of superoxidase dismutase (SOD and glutathione peroxidase (GSH-Px and decreased the level of the lipid peroxidation product malondialdehyde (MDA in the liver, therefore decreasing the activity of alanine aminotransferase (ALT. In conclusion, we provide novel experimental evidence that wedelolactone possesses lipid-lowering and steatosis-improving effects, and the underlying mechanism is, at least in part, mediated by the activation of AMPK and the up-regulation of PPARα/LPL and LDLR.

Inhibition of the ERK phosphorylation plays a role in terbinafine-induced p21 up-regulation and DNA synthesis inhibition in human vascular endothelial cells

International Nuclear Information System (INIS)

Ho, P.-Y.; Hsu, S.-P.; Liang, Y.-C.; Kuo, M.-L.; Ho, Y.-S.; Lee, W.-S.

2008-01-01

Previously, we showed that terbinafine (TB) induces cell-cycle arrest in cultured human umbilical vein endothelial cells (HUVEC) through an up-regulation of the p21 protein. The aim of this study is to delineate the molecular mechanisms underlying TB-induced increase of p21 protein. RT-PCR analysis demonstrated that the mRNA levels of p21 and p53 were increased in the TB-treated HUVEC. The p21 promoter activity was also increased by TB treatment. Transfection of HUVEC with p53 dominant negative (DN) abolished the TB-induced increases of p21 promoter activity and protein level, suggesting that the TB-induced increase of p21 is p53-dependent. Western blot analysis demonstrated that TB decreased the levels of phosphorylated extracellular signal-regulated kinase (ERK). Over-expression of mitogen-activated protein kinase (MEK)-1, the immediate upstream activator kinase of ERK, abolished the TB-induced increases of p21 and p53 protein and decrease of thymidine incorporation. The ERK inhibitor (PD98059) enhanced the TB-induced inhibition of thymidine incorporation into HUVEC. Taken together, these data suggest that the decrease of ERK activity plays a role in the TB-induced up-regulation of p21 in HUVEC. On the other hand, pretreatment of the cells with geranylgeraniol (GGOH), farnesol (FOH), or Ras inhibitor peptide did not affect the TB-induced decrease of thymidine incorporation. Taken together, our results suggest that TB might cause a decrease of MEK, which in turn up-regulates p53 through the inhibition of ERK phosphorylation, and finally causes an increase of p21 expression and cell-cycle arrest

Characterization of a Novel 99mTc-Carbonyl Complex as a Functional Probe of MDR1 P-Glycoprotein Transport Activity

Directory of Open Access Journals (Sweden)

Mary Dyszlewski

2002-01-01

Full Text Available Multidrug resistance (MDR mediated by overexpression of MDR1 P-glycoprotein (Pgp is one of the best characterized barriers to chemotherapy in cancer patients. Furthermore, the protective function of Pgp-mediated efflux of xenobiotics in various organs has a profound effect on the bioavailability of drugs in general. Thus, there is an expanding requirement to noninvasively interrogate Pgp transport activity in vivo. We herein report the Pgp recognition properties of a novel 99mTc(I-tricarbonyl complex, [99mTc(CO3(MIBI3] + (Tc-CO-MIBI. Tc-CO-MIBI showed 60-fold higher accumulation in drug-sensitive KB 3–1 cells compared to colchicine-selected drug-resistant KB 8-5 cells. In KB 8-5 cells, tracer enhancement was observed with the potent MDR modulator LY335979 (EC50 = 62 nM. Similar behavior was observed using drug-sensitive MCF-7 breast adenocarcinoma cells and MCF-7/MDR1 stable transfectants, confirming that Tc-CO-MIBI is specifically excluded by overexpression of MDR1 Pgp. By comparison, net accumulation in control H69 lung tumor cells was 9-fold higher than in MDR-associated protein (MRP1-expressing H69AR cells, indicating only modest transport by MRP1. Biodistribution analysis following tail vein injection of Tc-CO-MIBI showed delayed liver clearance as well as enhanced brain uptake and retention in mdr1a/1b(−/− gene deleted mice versus wild-type mice, directly demonstrating that Tc-CO-MIBI is a functional probe of Pgp transport activity in vivo.

Niemann-Pick C1 like 1 gene expression is down-regulated by LXR activators in the intestine

International Nuclear Information System (INIS)

Duval, Caroline; Touche, Veronique; Tailleux, Anne; Fruchart, Jean-Charles; Fievet, Catherine; Clavey, Veronique; Staels, Bart; Lestavel, Sophie

2006-01-01

Niemann-Pick C1 like 1 (NPC1L1) is a protein critical for intestinal cholesterol absorption. The nuclear receptors peroxisome proliferator-activated receptor alpha (PPARα) and liver X receptors (LXRα and LXRβ) are major regulators of cholesterol homeostasis and their activation results in a reduced absorption of intestinal cholesterol. The goal of this study was to define the role of PPARα and LXR nuclear receptors in the regulation of NPC1L1 gene expression. We show that LXR activators down-regulate NPC1L1 mRNA levels in the human enterocyte cell line Caco-2/TC7, whereas PPARα ligands have no effect. Furthermore, NPC1L1 mRNA levels are decreased in vivo, in duodenum of mice treated with the LXR agonist T0901317. In conclusion, the present study identifies NPC1L1 as a novel LXR target gene further supporting a crucial role of LXR in intestinal cholesterol homeostasis

Intercomparison measurements of activity of 99mTc and 131I in nuclear medicine services at Recife city, Pernambuco state, Brazil

International Nuclear Information System (INIS)

Barreto, F.C.P.; Santos, M.A.P dos; Oliveira, M.L.; Lima, F.F. de

2007-01-01

The aim of this work is to present the results of the first round of intercomparison measurements of activity of 99m Tc and 131 I. This round was carried out in Recife/PE. Six nuclear medicine services (NMS), public and private, participated in this intercomparison. Additionally to the activity measurement, some information about equipment (calibration and quality control program) and human resources was obtained. All NMS participants complied with the limit established by CNEN for the accuracy of measurement (+- 10%) for 99m Tc and 131 I. Measurements will be repeated for 99m Tc and 131 I, and additional rounds will be performed including different radionuclides. (author)

International Comparability of 131I, 201TI and 99mTc Activity Measurements performed in Cuban Nuclear Medicine

International Nuclear Information System (INIS)

Oropesa, P; Serra, R; Hernandez, A.T.; Varela, C

2006-01-01

This paper refers about the International Comparability of 131 I, 201 TI and 99m Tc Activity Measurements performed in Cuban Nuclear Medicine. Traceability of activity measurements in nuclear medicine based in two aspects: Comparability of clinic results and the safe and effective use of drugs. A bilateral international comparison for activity measurements CIEMAT CENTIS DMR was done. 2000-2004 National Program for 99m Tc 201 TI, 131 I vial and syringe measurements in radionuclide calibrators including a simulated test for activity administration. It is employed the Cause Effect Diagram for the activity measurement result of a source in the calibrator and the statistical methods for comparing several characteristics of the obtained data. The result of the comparisons demonstrates that the measurement quality has increased from one year to another

Imaging human atherosclerosis with /sup 99m/Tc-labeled low density lipoproteins

International Nuclear Information System (INIS)

Lees, A.M.; Lees, R.S.; Schoen, F.J.; Isaacsohn, J.L.; Fischman, A.J.; McKusick, K.A.; Strauss, H.W.

1988-01-01

The feasibility of localizing human atherosclerotic plaques by gamma scintillation camera external imaging with technetium-99m-labeled low density lipoproteins (99mTc-LDL) was tested in 17 patients who had atherosclerosis. Imaging demonstrated focal accumulation of radiolabel consistent with 99mTc-LDL sequestration by plaques in the carotid, iliac, or femoral vessels of four patients 8 to 21 hours after intravenous injection of the radiopharmaceutical. Focal accumulation of 99mTc-LDL also appeared in the location of coronary lesions in four patients, but this accumulation could not be distinguished with certainty from residual blood pool radioactivity. When carotid endarterectomy specimens from six patients who received 99mTc-LDL 1 day before endarterectomy were examined, the specimens had focal accumulations of radiolabel, with two to four times greater radioactivity in some regions of each specimen than in others; this occurred whether or not the lesions were detected on the gamma camera images. Lesion composition may have determined whether accumulation was quantitatively sufficient to produce an external image. Histologically, the imaged carotid specimen had abundant foam cells and macrophages and poorly organized intramural blood consistent with a plaque hemorrhage; in contrast, nonimaged endarterectomy specimens were mature, fibrocalcific plaques. We conclude that: 1) 99mTc-LDL did accumulate in human atherosclerotic plaques; 2) in some patients, the accumulation of 99mTc-LDL was sufficient for detection by gamma camera imaging; 3) the amount of LDL that accumulated appeared to depend on lesion composition; and 4) the design of new radiopharmaceuticals with reduced residual blood pool activity relative to plaque accumulation should lead to improved external imaging of atherosclerosis

Quality assurance of Mo-99/Tc-99m radionuclide generators

Science.gov (United States)

Uzunov, Nikolay; Yordanova, Galina; Salim, Seniha; Stancheva, Natalya; Mineva, Vanya; Meléndez-Alafort, Laura; Rosato, Antonio

2018-03-01

Gamma-ray spectrometry analyses of the radionuclide content of eluate from two Mo-99/Tc-99m radionuclide generators POLTECHNET have been performed. The relative activities of 99Mo 103Ru and 131I radioisotopes with respect to the activity of 99mTc at different time intervals after the primary pertechnetate elution of the generators have been analyzed. The relative activities of the isotopes were determined and compared to the radionuclidic purity requirements for 99mTc.

Radiopharmaceuticals to 99mTc

International Nuclear Information System (INIS)

Leon Cabana, Alba

1994-01-01

Studies about 99m Tc had demonstrated that have favorable properties for support diagnostic proceedings in nuclear medicine. This physical and chemical properties used for obtain another radiopharmaceuticals have been employed through re actives kits labelled with Tc 99m . A brief description was given about 99m utilities in diagnostic techniques such as endothelium reticular system,renal and hepatic studies,bone scintillators,cardiac diagnostic and cerebral perfusion

Specificity of pH sensitive Tc(V)-DMS for acidophilic osteoclastic bone cells: biological and cellular studies

International Nuclear Information System (INIS)

Horiuchi, K.; Konno, A.; Nishio, S.; Fukuda, Y.; Saji, H.; Hashimoto, K.

2002-01-01

Bone scintigraphy is a sensitive imaging method for detecting skeletal metastases but the low specificity has decreased its oncological use. Bone scintigraphy has relied on Tc-bisphosphonate (Tc-BP) agents with affinity for the mineral phase. However, bio-functional Tc(V)-DMS agent, sensitive to acid pH of tumoral tissue has shown osteotrophic properties, in adult bone pathologies. Objectives: Basis for understanding the osteotropic character of the pH sensitive Tc(V)-DMS in bone metastasis. Methods: Studies on differential Tc(V)-DMS and Tc-BP accumulation response were carried out by acidophilic osteoclast (OC) and basophilic osteoblast (OB) cells subjected to variable pH incubation media (HEPES, 37 0 C) and by bone tissue of Ehrlich Ascites Tumor (EAT) bearing mice, exposed to systemic NH4Cl or glucose mediated acidification (GmAc). Agents injected into tail vein and bone radioactivity analyzed. Bone metabolism markers measured in blood and urine (pH, Pi, Ca , Alp, Dpd). Acid-base regulation effect at cellular level, analyzed by using bafilomycin, amiloride, DIDS and acetazolamide inhibitors. Results: Lack of any OB response to acidification or alkalinization detected with either Tc(V)-DMS or Tc-BP agent. However, OC cells were highly sensitivity to acidification only in the presence of Tc(V)-DMS showing great radioactivity increase as the pH was lowered. This specificity also detected, in EAT bearing mice; increased bone tissue accumulation in response to systemic acidification was clearly detected upon administration of Tc(V)-DMS only under GmAc, an experimental model showing high urine excretion of deoxypyridinoline, a bone resorption marker. Conclusion: Peculiarity of multi nucleated OC cells sensitive to the environment pH and their activation in acid pH has been well known. Tc-BP agent showed lack of affinity for OC or OB cells. Specific affinity of OC cells for Tc(V)-DMS and its increased bone accumulation with the systemic pH lowering reflect the p

Non-visualized Thyroid Gland by Tc-{sup 99m} MIBI Scan with Normal Thyroid Scan

Energy Technology Data Exchange (ETDEWEB)

Koca, Gokhan; Atilgan, Hasan Ikbal; Baskin, Aylin; Demirel, Koray; Korkmaz, Meliha [Ankara Training and Research Hospital, Ankara (Turkmenistan)

2013-09-15

We present the case of a 21-year-old man who was referred to us for parathyroid scintigraphy with high blood levels of intact parathormone and osteoporosis. Several methods and radiopharmaceuticals, e.g., Tc-99m MIBI and Tl-201 chloride/Tc-99m pertechnetate (Tl-201/TcPO{sup -4}) subtraction, are commonly used for this purpose. We present the case of a thyroid gland that demonstrates quite normal Tc-99m pertechnetate uptake, no accumulation of Tc-99m MIBI, and very low grade Tl-201 uptake. To the best of our knowledge, no similar case has been reported previously. A 21-year-old male with osteoporosis and growth-development retardation was referred for MIBI parathyroid scan because of high blood levels of intact parathormone and bone-specific alkaline-phosphatase, which were 219.4 (15-88 pg/ml) and 355 (21-58 U/L), respectively. In his Tc-99m pertechnetate (TcPO{sup -4}) pinhole scintigraphy, bilateral clearly visualized radioactivity accumulation in the thyroid gland was seen. In both early or late images of the Tc-99m MIBI parathyroid scan, the thyroid gland was not visualized. Therefore, a Tl-201/TcPO{sub -4} subtraction scan method was used. However, the Tl-201 accumulation level in the thyroid gland was not sufficient for the subtraction method. In his thyroid ultrasonography, the thyroid gland echo was homogenous, and there was neither any solid nor cystic lesion. The physical examination of his neck was normal. Other laboratory findings were all normal as follows. TSH: 3.03 (0.35-5.6 IU/mL), free T3: 3.66 (2.5-3.9 pg/mL), free T4: 0.90 (0.59-1.3 ng/dL), Anti-TPO:0.3 (0.40 IU/mL), Anti-TG-Ab: <2.2 (0-+u/L), TSH receptor Ab: 1.0 (0.14 U/L), osteocalcine: 9.13 (1.5-15 ng/dL), growth hormone: 1.3 (0.014-5.21), calcitonin:17 (0.150 ng/mL), sedimentation:6 (0.15 mm/h). There were no significant symptoms of acute or chronic thyroiditis. The cause for discordant uptake in the thyroid gland with T1-201 and Tc-99m MIBI scan could not be provided through clinical or

Optimization method for the administered activity to patients in Tc-99-HMPAO cerebral blood flow SPECT in adults

International Nuclear Information System (INIS)

Perez Diaz, Marlen; Estevez Aparicio, Eric; Roque Diaz, Reinaldo; Hernandez Rodriguez, Carlos

2002-01-01

A method based on the construction of an image quality discriminant function is proposed. The parameters which characterise it are selected among the typical ones measured in a Tc 99m - HMPAO cerebral blood flow SPECT. The results are compared among groups of patient's studies who received different activity (430, 640 and 807 MBq), looking for the minimum that guaranty good image quality. A reduction in the administered 99m Tc-HMPAO activity to the patient down to 430 MBq was possible without affecting the tomographic image quality. The labelling yield was the main parameter that determined the image quality. (author)

Olanzapine induced Q-Tc shortening.

Science.gov (United States)

Shoja Shafti, Saeed; Fallah Jahromi, Parisa

2014-12-01

Prolongation of Q-Tc interval is commonly accepted as a surrogate marker for the ability of a drug to cause torsade de pointes. In the present study, safety of olanzapine versus risperidone was compared among a group of patients with schizophrenia to see the frequency of the electrocardiographic alterations induced by those atypical antipsychotics. Two hundred and sixty-eight female inpatients with schizophrenia entered in one of the two parallel groups to participate in an open study for random assignment to olanzapine (n = 148) or risperidone (n = 120). Standard 12-lead surface electrocardiogram (ECG) was taken from each patient at baseline, before initiation of treatment, and then at the end of management, just before discharge. The parameters that were assessed included heart rate (HR), P-R interval, QRS interval, Q-T interval (corrected = Q-Tc), ventricular activation time (VAT), ST segment, T wave, axis of QRS, and finally, interventricular conduction process. A total of 37.83% of cases in the olanzapine group and 30% in the risperidone group showed some Q-Tc changes; 13.51% and 24.32% of the patients in the olanzapine group showed prolongation and shortening of the Q-Tc, respectively, while changes in the risperidone group were restricted to only prolongation of Q-Tc. Comparison of means showed a significant increment in Q-Tc by risperidone (p = 0.02). Also, comparison of proportions in the olanzapine group showed significantly more cases with shortening of Q-Tc versus its prolongation (p = 0.01). No significant alterations with respect to other variables were evident. Olanzapine and risperidone had comparable potentiality for induction of Q-Tc changes, while production of further miscellaneous alterations in ECG was more observable in the olanzapine group compared with the risperidone group. Also shortening of Q-Tc was specific to olanzapine.

Membranes of activated CD4+ T cells expressing T cell receptor (TcR) alpha beta or TcR gamma delta induce IgE synthesis by human B cells in the presence of interleukin-4

NARCIS (Netherlands)

Gascan, H.; Aversa, G. G.; Gauchat, J. F.; van Vlasselaer, P.; Roncarolo, M. G.; Yssel, H.; Kehry, M.; Spits, H.; de Vries, J. E.

1992-01-01

In the present study it is demonstrated that human B cells can be induced to switch to IgE production following a contact-mediated signal provided by activated T cell receptor (TcR) gamma delta+, CD4+ and TcR alpha beta+, CD4+ T cell clones and interleukin (IL)-4. The signal provided by these T cell

Pharmacological study of 99mTc-CO-MIBI, a new mycoardial perfusion imaging agent comparison to 99mTc-MIBI

International Nuclear Information System (INIS)

Zhao Jiandong; Wang Jincheng; Mi Hongzhi

2004-01-01

pharmacokinetics parameters, biodistribution, T/NT radios were collected and calculated during and after the imaging. Moreover, the whole body image, heart planer scintigraphy and tomography were investigated on pharmacodynamics. The same procedure were performed to 99m Tc-MIBI. Results:Blood-pool clearance of 99m Tc-CO-MIBI was modeled and found to be biexponential during 2 hours after injection. The pharmacokinetics conform to two-compartment with 436.36±54.77 ml/h of blood clearance (CL) and half lives T α(1/2 ))=l.46±0.13 min for the fast early clearance, T β(1/2) =97.3+20.51 min for the slow late clearance. The clearance kinetics were faster than 99m Tc-MIBI which of CL=25 8.76±27.88 ml/h, T α(1/2) =2.21±0.09 min, T β(1/2) =163±14.1 min, respectively. The time-radioactivity curves showed that the pulmonary uptake curves were the lowest, the hepatic uptake curves were above the hearts early but descending so quickly as to start bellowing the heart curves at about 40min which were significant difference of 99m Tc-MIBI. To the latter, the liver curves were above the myocardial uptake curves sustained over 2 hours period post injection. The heart uptake ID% of 99m Tc-CO-MIBI were more than that of 99m Tc-MIBI at 10, 30, 60, 90, 120 min. The heart-lung and heart-liver ratios were also significantly different. For 99m Tc-CO-MIBI, they were 3.18±0.08 and 1.05±0.05 by 40 min while 99m Tc-MIBI 2.87±0.11 and 0.70±0.05, respectively. The planar and SPECT imaging of excellent quality during 10 to 120 min demonstrated that 99m Tc-CO-MIBI was high absorbed initially by myocardium and quickly clearance from liver. The whole body image show that the radioactivity mostly removed to the gallbladder and the intestines either. We can obtain perfect myocardial image without liver activity disturbance in condition of no extra fatty diets Conclusions: The result of this study suggested that the single alkaline component 99m Tc-CO-MIBI solution had better pharmacokinetics properties and

Apoptotic abscess imaging with {sup 99m}Tc-HYNIC-rh-Annexin-V

Energy Technology Data Exchange (ETDEWEB)

Penn, David L.; Kim, Christopher; Zhang, Kaijun; Mukherjee, Archana; Devakumar, Devadhas; Jungkind, Donald [Department of Radiology, Thomas Jefferson University, Philadelphia, PA 19107 (United States); Thakur, Mathew L. [Department of Radiology, Thomas Jefferson University, Philadelphia, PA 19107 (United States)], E-mail: mathew.thakur@jefferson.edu

2010-01-15

Abscess formation causes systemic and localized up-regulation of neutrophil [polymorphonuclear leukocytes (PMNs)] signaling pathways. In the abscess, following bacterial ingestion or PMN activation by inflammatory mediators, PMN apoptosis is elevated and leads to the externalization of phosphatidylserine. Annexin-V (AnxV) has been shown to have high affinity to externalized phosphatidylserine. We hypothesized that {sup 99m}Tc-AnxV will target high densities of apoptotic PMNs and image abscesses. AnxV, conjugated with hydrazinenicaotinamide (HYNIC), was labeled with reduced {sup 99m}TcO{sub 4}{sup -} and its purity was determined by instant thin-layer chromatography. Apoptosis was induced in isolated human PMNs by incubation in 2% saline for 17 and 22 h at 37 deg. C. PMNs were then incubated with {sup 99m}Tc-HYNIC-AnxV and associated {sup 99m}Tc was determined. Abscesses were induced in mice by intramuscular injection of bacteria or turpentine. Following intravenous administration of {sup 99m}Tc-HYNIC-AnxV, mice were imaged and tissue distribution studied at 4 and 24 h. Radiochemical purity of {sup 99m}Tc-HYNIC-AnxV was 84.9{+-}8.11%. At 17 h, {sup 99m}Tc-HYNIC-AnxV bound to apoptotic PMNs was 71.6{+-}0.01% and 48.6{+-}0.01% for experimental and control cells, respectively (P=.002). At 22 h, experimental cells retained 74.9{+-}0.02% and control cells retained 47.2{+-}0.02% (P=.005). {sup 99m}Tc-HYNIC-AnxV associated with bacterial abscesses was 1.25{+-}0.09 and 3.75{+-}0.83 percent injected dose per gram (%ID/g) at 4 and 24 h compared to turpentine abscesses which was 1.02{+-}0.16 and 0.72{+-}0.17 %ID/g at 4 (P{<=}.05) and 24 h (P{<=}.01). {sup 99m}Tc-HYNIC-AnxV represents a minimally invasive and promising agent to image and potentially distinguish between infectious and inflammatory abscesses.

Immobilization of {sup 99}Tc (Re) using Iron-Phosphate Glasses

Energy Technology Data Exchange (ETDEWEB)

Heo, Jong; Xu, Kai; Um, Woo Yong; Hrma, Pavel [Pohang Univ. of Science and Technology, Pohang (Korea, Republic of)

2012-05-15

Technetium-99 ({sup 99}Tc) is a fission product artificially generated during the irradiation of {sup 235}U for commercial power production or {sup 239}Pu for nuclear weapons. Under oxidizing conditions, the dominant species of Tc, the pertechnetate anion (TcO{sub 4} {sup -}), is highly soluble in ground water and thus easily transports through the geologic systems. In addition, because of its high fission yield ({approx}6 %) and long half-life (2.1x10{sup 5} yr), immobilization of {sup 99}Tc has been investigated for decades. Several waste forms such as metallic alloys, sintered titanate ceramics and chemically bonded phosphate ceramics have been proposed to encapsulate {sup 99}Tc. They have not yet been realized in the industrial-scale, mostly either due to the high volatilization of {sup 99}Tc during high temperature process (>1300 .deg. C), or the low {sup 99}Tc loading. Iron-phosphate (FeP) glasses have been developed as alternative waste forms because of their chemical durability equivalent to borosilicate glasses. Additionally, vitrification of radioactive waste by FeP glasses can be done at a relatively low temperature ({approx}1000 .deg. C) and the low-temperature process can reduce the volatilization of {sup 99}Tc significantly. Thus, this work reports the immobilization of {sup 99}Tc by FeP glasses using rhenium (Re) as a surrogate. We also examine the chemical durability of Re-containing FeP glasses using product consistency test (PCT). Experimental results reveal that FeP glass can become a promising candidate for immobilizing {sup 99}Tc

Translational Upregulation of an Individual p21Cip1 Transcript Variant by GCN2 Regulates Cell Proliferation and Survival under Nutrient Stress.

Directory of Open Access Journals (Sweden)

Stacey L Lehman

2015-06-01

Full Text Available Multiple transcripts encode for the cell cycle inhibitor p21(Cip1. These transcripts produce identical proteins but differ in their 5' untranslated regions (UTRs. Although several stresses that induce p21 have been characterized, the mechanisms regulating the individual transcript variants and their functional significance are unknown. Here we demonstrate through (35S labeling, luciferase reporter assays, and polysome transcript profiling that activation of the Integrated Stress Response (ISR kinase GCN2 selectively upregulates the translation of a p21 transcript variant containing 5' upstream open reading frames (uORFs through phosphorylation of the eukaryotic translation initiation factor eIF2α. Mutational analysis reveals that the uORFs suppress translation under basal conditions, but promote translation under stress. Functionally, ablation of p21 ameliorates G1/S arrest and reduces cell survival in response to GCN2 activation. These findings uncover a novel mechanism of p21 post-transcriptional regulation, offer functional significance for the existence of multiple p21 transcripts, and support a key role for GCN2 in regulating the cell cycle under stress.

Tc7, a Tc1-hitch hiking transposon in Caenorhabditis elegans.

OpenAIRE

Rezsohazy, R; van Luenen, H G; Durbin, R M; Plasterk, R H

1997-01-01

We have found a novel transposon in the genome of Caenorhabditis elegans. Tc7 is a 921 bp element, made up of two 345 bp inverted repeats separated by a unique, internal sequence. Tc7 does not contain an open reading frame. The outer 38 bp of the inverted repeat show 36 matches with the outer 38 bp of Tc1. This region of Tc1 contains the Tc1-transposase binding site. Furthermore, Tc7 is flanked by TA dinucleotides, just like Tc1, which presumably correspond to the target duplication generated...

Bone uptake of Tc-99m MIBI in patients with hyperparathyroidism

International Nuclear Information System (INIS)

Zhao, Yunyun; Wang, Qian

2014-01-01

The study aimed to investigate the incidence of bone uptake of tracer on Tc-99m MIBI imaging and explore its influencing factors and significance for diagnosis of metabolic bone disease (MBD) in patients with hyperparathyroidism (HPT). Seventy-nine consecutive patients with histopathologically confirmed HPT (63 primary and 16 secondary) who had preoperative Tc-99m MIBI imaging were retrospectively evaluated. Serum calcium (Ca), phosphorus (P), and intact parathyroid hormone (iPTH) were measured for all patients, and serum alkaline phosphatase (ALP) was measured for 62 patients. Of the 79 patients, 50 underwent bone mineral density (BMD) examination and 30 underwent bone scintigraphy. The incidence and characteristics of abnormal bone uptake of MIBI were recorded. Mann-Whitney test was performed to determine if serum iPTH, Ca, P, ALP, and BMD were different between the patients with and without MIBI bone uptake. Logistic regression analysis was used to analyze the factors that influence the bone uptake of MIBI. The concordance rate between Tc-99m MIBI imaging and bone scintigraphy in delineating MBD was calculated. Tc-99m MIBI imaging disclosed the abnormal bone uptake of tracer in 22 (27.8%) patients. Of them, 19 showed diffusely increased activity in skeleton, 2 showed focal uptake in brown tumors, and one showed both above patterns. Patients with bone uptake MIBI had higher level of serum iPTH (Z=-4.34, P < 0.001) and ALP (Z=-3.50, P < 0.001) than those without bone uptake. Logistic regression analysis also showed that bone uptake of MIBI was correlated with serum iPTH (OR=4.42, P < 0.001) and ALP (OR=3.21, P=0.002). Among the 30 patients that underwent bone scintigraphy, 76.7% patients showed signs of MBD, and the concordance rate between Tc-99m MIBI imaging and bone scintigraphy was 60% for detecting MBD. Bone uptake of MIBI in patients with HPT is commonly related to a high level of iPTH and ALP; it probably reflects an active stage of MBD, and it should be

BRD4 regulates cellular senescence in gastric cancer cells via E2F/miR-106b/p21 axis.

Science.gov (United States)

Dong, Xingchen; Hu, Xiangming; Chen, Jinjing; Hu, Dan; Chen, Lin-Feng

2018-02-12

Small molecules targeting bromodomains of BET proteins possess strong anti-tumor activities and have emerged as potential therapeutics for cancer. However, the underlying mechanisms for the anti-proliferative activity of these inhibitors are still not fully characterized. In this study, we demonstrated that BET inhibitor JQ1 suppressed the proliferation and invasiveness of gastric cancer cells by inducing cellular senescence. Depletion of BRD4, which was overexpressed in gastric cancer tissues, but not other BET proteins recapitulated JQ1-induced cellular senescence with increased cellular SA-β-Gal activity and elevated p21 levels. In addition, we showed that the levels of p21 were regulated at the post-transcriptional level by BRD4-dependent expression of miR-106b-5p, which targets the 3'-UTR of p21 mRNA. Overexpression of miR-106b-5p prevented JQ1-induced p21 expression and BRD4 inhibition-associated cellular senescence, whereas miR-106b-5p inhibitor up-regulated p21 and induced cellular senescence. Finally, we demonstrated that inhibition of E2F suppressed the binding of BRD4 to the promoter of miR-106b-5p and inhibited its transcription, leading to the increased p21 levels and cellular senescence in gastric cancer cells. Our results reveal a novel mechanism by which BRD4 regulates cancer cell proliferation by modulating the cellular senescence through E2F/miR-106b-5p/p21 axis and provide new insights into using BET inhibitors as potential anticancer drugs.

Cellular uptake of {sup 99m}TcN-NOET in human leukaemic HL-60 cells is related to calcium channel activation and cell proliferation

Energy Technology Data Exchange (ETDEWEB)

Guillermet, Stephanie; Vuillez, Jean-Philippe; Caravel, Jean-Pierre; Marti-Batlle, Daniele; Fagret, Daniel [Universite de Grenoble, Radiopharmaceutiques Biocliniques, La Tronche (France); Fontaine, Eric [Universite de Grenoble, Laboratoire de Bioenergetique Fondamentale et Appliquee, Grenoble (France); Pasqualini, Roberto [Cis Bio International Schering SA, Gif-sur-Yvette (France)

2006-01-01

A major goal of nuclear oncology is the development of new radiolabelled tracers as proliferation markers. Intracellular calcium waves play a fundamental role in the course of the cell cycle. These waves occur in non-excitable tumour cells via store-operated calcium channels (SOCCs). Bis(N-ethoxy, N-ethyldithiocarbamato) nitrido technetium (V)-99m ({sup 99m}TcN-NOET) has been shown to interact with L-type voltage-operated calcium channels (VOCCs) in cultured cardiomyocytes. Considering the analogy between VOCCs and SOCCs, we sought to determine whether {sup 99m}TcN-NOET also binds to activated SOCCs in tumour cells in order to clarify the potential value of this tracer as a proliferation marker. Uptake kinetics of {sup 99m}TcN-NOET were measured in human leukaemic HL-60 cells over 60 min and the effect of several calcium channel modulators on 1-min tracer uptake was studied. The uptake kinetics of {sup 99m}TcN-NOET were compared both with the variations of cytosolic free calcium concentration measured by indo-1/AM and with the variations in the SG{sub 2}M cellular proliferation index. All calcium channel inhibitors significantly decreased the cellular uptake of {sup 99m}TcN-NOET whereas the activator thapsigargin induced a significant 10% increase. In parallel, SOCC activation by thapsigargin, as measured using the indo-1/AM probe, was inhibited by nicardipine. These results indicate that the uptake of {sup 99m}TcN-NOET is related to the activation of SOCCs. Finally, a correlation was observed between the tracer uptake and variations in the proliferation index SG{sub 2}M. The uptake of {sup 99m}TcN-NOET seems to be related to SOCC activation and to cell proliferation in HL-60 cells. These results indicate that {sup 99m}TcN-NOET might be a marker of cell proliferation. (orig.)

Results of regular study on radionuclidic purity of sup(99m)Tc obtained from 99Mo-sup(99m)Tc generators

International Nuclear Information System (INIS)

Vlcek, J.; Rohacek, J.; Husak, V.

1979-01-01

A total of 39 sup(99m)Tc eluates obtained from 9 99 Mo-sup(99m)Tc generators delivered by The Radiochemical Centre Amersham during one year was studied with regard to their radionuclide purity. Using a Ge(Li) spectrometer the contaminants 60 Co, 103 Ru, 131 I, 134 Cs, 140 La and 188 Re were found in sup(99m)Tc-eluates with average levels ranging from 2.9 x 10 -3 to 2.8 x 10 -1 per cent of sup(99m)Tc activity. The additional total body absorbed dose caused by these contaminants, as calculated from their average content in sup(99m)Tc eluates, was less than 1% of the dose due to sup(99m)Tc pertechnetate. (orig.) 891 MG/orig. 892 CS [de

Enhanced 99 Tc retention in glass waste form using Tc(IV)-incorporated Fe minerals

Energy Technology Data Exchange (ETDEWEB)

Um, Wooyong; Luksic, Steven A.; Wang, Guohui; Saslow, Sarah; Kim, Dong-Sang; Schweiger, Michael J.; Soderquist, Chuck Z.; Bowden, Mark E.; Lukens, Wayne W.; Kruger, Albert A.

2017-11-01

Technetium (99Tc) immobilization by doping into iron oxide mineral phases may alleviate the problems with Tc volatility during vitrification of nuclear waste. Reduced Tc, Tc(IV), substitutes for Fe(III) in the crystal structure by a process of Tc reduction from Tc(VII) to Tc(IV) followed by co-precipitation of Fe oxide minerals. Two Tc-incorporated Fe minerals (Tc-goethite and Tc-magnetite/maghemite) were prepared and tested for Tc retention in glass melt samples at temperatures between 600 – 1,000 oC. After being cooled, the solid glass specimens prepared at different temperatures were analyzed for Tc oxidation state using Tc K-edge XANES. In most samples, Tc was partially oxidized from Tc(IV) to Tc(VII) as the melt temperature increased. However, Tc retention in glass melt samples prepared using Tc-incorporated Fe minerals were moderately higher than in glass prepared using KTcO4 because of limited and delayed Tc volatilization.

Comparative study of 99Mo/99mTc generators at base of synthesized gels starting from 99Mo of activation and of fission

International Nuclear Information System (INIS)

Lopez M, I.Z.; Monroy G, F.; Rivero G, T.; Rojas N, P.

2007-01-01

At the present time the more used and diffused radionuclide in nuclear medicine it is the Technetium 99 metastable ( 99 mTc) it is used for diagnostic and therapy. It is produced starting from molybdenum 99 ( 99 Mo), which is absorbed in chromatographic columns, loaded with alumina that absorb only 0.2% of 99 Mo situation that forces to use high specific activities of 99 Mo that it is obtained starting from the fission of the 235 U. Given these conditions and limitations, new preparation procedures of 99 Mo/ 99m Tc generators, of low or medium specific activity, its have been developed, using gels of zirconium molybdates that incorporates until 30% in weight of 99 Mo in the gel, and also conserve similar characteristics of quality and purity that those obtained by the traditional generator; reducing by this way the cost of production of the 99m Tc, when using 99 Mo of low specific activity, in the preparation of 99 Mo/ 99m Tc generators. The radiochemical characteristics of the elution of 99m Tc, depends strongly on the gel preparation conditions. In particular, the present work has for object to determine the influence of the used type of 99 Mo, fission or activation product, during the gels synthesis, as well as the used air flow for the agitation in the gels preparation and its influence in the quality of the 99 Mo/ 99m Tc generators. When diminishing the agitation air flow the efficiency it increases and in the radionuclide purity of the eluates and when using 99 Mo of fission for the gels production it increases in an important way the elution efficiency, the radiochemical purity and radionuclide of the eluates of 99m Tc. (Author)

Influence of solution treatment on microstructure evolution of TC21 titanium alloy with near equiaxed β grains fabricated by laser additive manufacture

International Nuclear Information System (INIS)

Zhang, Q.; Chen, J.; Tan, H.; Lin, X.; Huang, W.D.

2016-01-01

Laser additive manufacture (LAM) is a novel technique in which metal components can be fabricated layer by layer. In this paper, the effects of solution temperature and cooling rate on microstructure evolution of the LAMed TC21 titanium alloy which containing near equiaxed prior β grains were studied. The LAMed and solution treated samples were investigated by optical microscopy (OM), scanning election microscope (SEM) and X-ray diffractometer (XRD). The results indicate that both the α phase volume fraction and α laths width are affected by the solution temperature and cooling rate. Different microstructure characterization leads to different Vickers hardness values. However, the solution temperatures selected in this study have insignificant effects on the β and α phase texture. The near equiaxed prior β grains exhibits much weaker texture intensity than the typical columnar prior β grains. The comparison of the calculated and measured α phase texture indicates that variant selection occurred during the solution treatment. The martensite α′ phase precipitated during the layer by layer process shows weak variant selection tendency. - Highlights: • LAMed TC21 titanium alloy containing near equiaxed β grains was fabricated. • Near equiaxed β grains exhibit weaker texture intensity than columnar β grains. • The solution treatment below T_β had insignificant effect on α phase texture. • Variant selection occurred during the solution treatment.

Influence of the irradiation time on the activity of decay products during the cooling. Case: Mo-98 → Mo-99 → Tc-99m

International Nuclear Information System (INIS)

Reyes J, J.L.; Ruiz C, M.A.; Alanis M, J.

2002-01-01

In this work the behavior of the activity in the cooling time of Mo-99, Tc-99 and Tc-99m obtained by Neutron activation of natural Mo is described. The analytical development is based on the application of the Laplace transform for resolving the balance equations. (Author)

PSMB4 promotes multiple myeloma cell growth by activating NF-κB-miR-21 signaling

Energy Technology Data Exchange (ETDEWEB)

Zheng, Peihao; Guo, Honggang [Department of Hematology, Navy General Hospital, Beijing 100048 (China); Li, Guangchao [School of Bioscience and Bioengineering, South China University of Technology, Guangzhou 510006 (China); Han, Siqi [Department of Medical Oncology, Jinling Hospital, Nanjing 210002 (China); Luo, Fei [Department of Stomatology, Jinling Hospital, Nanjing 210002 (China); Liu, Yi, E-mail: liuyi2033@163.com [Department of Hematology, Navy General Hospital, Beijing 100048 (China)

2015-03-06

Proteasomal subunit PSMB4, was recently identified as potential cancer driver genes in several tumors. However, the regulatory mechanism of PSMB4 on carcinogenesis process remains unclear. In this study, we investigated the expression and roles of PSMB4 in multiple myeloma (MM). We found a significant up-regulation of PSMB4 in MM plasma and cell lines. Ectopic overexpression of PSMB4 promoted cell growth and colony forming ability of MM cells, whereas inhibition of PSMB4 led to a decrease of such events. Furthermore, our results demonstrated the up-regulation of miR-21 and a positive correlation between the levels of miR-21 and PSMB4 in MM. Re-expression of miR-21 markedly rescued PSMB4 knockdown-mediated suppression of cell proliferation and clone-formation. Additionally, while enforced expression of PSMB4 profoundly increased NF-κB activity and the level of miR-21, PSMB4 knockdown or NF-κB inhibition suppressed miR-21 expression in MM cells. Taken together, our results demonstrated that PSMB4 regulated MM cell growth in part by activating NF-κB-miR-21 signaling, which may represent promising targets for novel specific therapies. - Highlights: • First reported upregulation of PSMB4 in MM plasma and cell lines. • PSMB4 promoted MM cell growth and colony forming ability. • Further found miR-21 was up-regulated by PSMB4 in MM plasma and cell lines. • PSMB4-induced miR-21 expression was modulated by NF-κB. • PSMB4-NF-κB-miR-21 axis may be potential therapeutic targets of MM.

Comparative binding characteristics of Tc-CPI, Tc-TBI, and Tc-MIBI in cultured heart cells: Correlation with biochemical analysis and animal images

International Nuclear Information System (INIS)

Piwnica-Worms, D.; Kronauge, J.F.; Holman, B.L.; Davison, A.; Jones, A.G.

1987-01-01

Hexakis (isonitrile)technetium (I) complexes are a new class of cationic, lipophilic myocaridal perfusion imaging agents. To better understand their cellular mechanisms of uptake and washout, chick heart cells grown in culture were used as a model myocardial system. Tc-MIBI showed uptake to a plateau at a rate similar to Tc-CPI (t1/2 = 4.1 +- 0.7 minutes); however, the plateau was 63% greater. Tc-TBI uptake approached a plateau 900% greater than Tc-CPI binding. Heart cell studies showed washout of Tc-CPI>Tc-TBI>Tc-MIBI, which correlated with kinetic analysis of rabbit myocardial images. Biochemical in vitro analysis in human plasma demonstrated 75% enzymatic ester hydrolysis of Tc-CPI by 3 minutes, but no hydrolysis of Tc-TBI and Tc-MIBI. The results suggest that metabolism of the ester function of Tc-CPI following myocardial uptake may in part account for the more rapid cellular washout rates of Tc-CPI compared with Tc-TBI and Tc-MIBI

Downregulation of PTP1B and TC-PTP phosphatases potentiate dendritic cell-based immunotherapy through IL-12/IFNγ signaling.

Science.gov (United States)

Penafuerte, Claudia; Feldhammer, Matthew; Mills, John R; Vinette, Valerie; Pike, Kelly A; Hall, Anita; Migon, Eva; Karsenty, Gerard; Pelletier, Jerry; Zogopoulos, George; Tremblay, Michel L

2017-01-01

PTP1B and TC-PTP are highly related protein-tyrosine phosphatases (PTPs) that regulate the JAK/STAT signaling cascade essential for cytokine-receptor activation in immune cells. Here, we describe a novel immunotherapy approach whereby monocyte-derived dendritic cell (moDC) function is enhanced by modulating the enzymatic activities of PTP1B and TC-PTP. To downregulate or delete the activity/expression of these PTPs, we generated mice with PTP-specific deletions in the dendritic cell compartment or used PTP1B and TC-PTP specific inhibitor. While total ablation of PTP1B or TC-PTP expression leads to tolerogenic DCs via STAT3 hyperactivation, downregulation of either phosphatase remarkably shifts the balance toward an immunogenic DC phenotype due to hyperactivation of STAT4, STAT1 and Src kinase. The resulting increase in IL-12 and IFNγ production subsequently amplifies the IL-12/STAT4/IFNγ/STAT1/IL-12 positive autocrine loop and enhances the therapeutic potential of mature moDCs in tumor-bearing mice. Furthermore, pharmacological inhibition of both PTPs improves the maturation of defective moDCs derived from pancreatic cancer (PaC) patients. Our study provides a new advance in the use of DC-based cancer immunotherapy that is complementary to current cancer therapeutics.

Solubility study of Tc(IV) oxides

International Nuclear Information System (INIS)

Liu, D.J.; Fan, X.H.

2005-01-01

The deep geological disposal of the high level radioactive wastes is expected to be a safer disposal method in most countries. The long-lived fission product 99 Tc is present in large quantities in nuclear wastes and its chemical behavior in aqueous solution is of considerable interest. Under oxidizing conditions technetium exists as the anionic species TcO 4 - whereas under the reducing conditions, expected to exist in a deep geological repository, it is generally predicted that technetium will be present as TcO 2 ·nH 2 O. Hence, the mobility of Tc(IV) in reducing groundwater may be limited by the solubility of TcO 2 ·nH 2 O under these conditions. Due to this fact it is important to investigate the solubility of TcO 2 ·nH 2 O. The solubility determines the release of radionuclides from waste form and is used as a source term in radionuclide migration analysis in performance assessment of radioactive waste repository. Technetium oxide was prepared by reduction of a technetate solution with Sn 2 + . The solubility of Tc(IV) oxide has been determined in simulated groundwater and redistilled water under aerobic and anaerobic conditions. The effects of pH and CO 3 2- concentration of solution on solubility of Tc(IV) oxide were studied. The concentration of total technetium and Tc(IV) species in the solutions were periodically determined by separating the oxidized and reduced technetium species using a solvent extraction procedure and counting the beta activity of the 99 Tc with a liquid scintillation counter. The experimental results show that the rate of oxidation of Tc(IV) in simulated groundwater and redistilled water is about (1.49-1.86) x 10 -9 mol/(L·d) under aerobic conditions, but Tc(IV) in simulated groundwater and redistilled water is not oxidized under anaerobic conditions. Under aerobic or anaerobic conditions the solubility of Tc(IV) oxide in simulated groundwater and redistilled water is equal on the whole after centrifugation or ultrafiltration. The

Evaluation of breast MIBI-Tc 99 m scintigraphy for the detection of breast cancer

International Nuclear Information System (INIS)

Loriaux, C.; Baeyens, L.; Paternot, J.; Martin, P.; Verhas, M.

1997-01-01

Full text. The aim of the work was to appreciate the contribution of MIBI-Tc 99 m scintigraphy for the detection of breast cancer and to situate this procedure in comparison with mammography 5 (X-ray M) and echography (E C). 21 patients presenting suspected lesion on clinical evaluation/or mammography were referred to the department for breast MIBI-Tc 99 m scintigraphy. 10 min after IV injection of MIBI-Tc 99 m 3 planar scan were realized with a present time of 10 min. The whole investigation including X-ray and surgical procedures were performed within 15 days. The pathologic findings were: 21 malignant lesion (18 canal cancers, 3 lobular cancers), 4 benign lesions (1 fibroadenoma, 2 granuloma, 1 fibrocystic disease). Lesions were bilateral in 3 cases and there was 1 bifocal lesion. 17 tumours were palpable and 8 not palpable, 10 lesion were 2,5 cm (24%). The overall sensitivity and specificity for MIBI-Tc 99 m were 67% and 75% respectively. For the group of palpable tumours, sensitivity of MIBI-Tc 99 m was 86%. In three cases, the X-ray M was difficult to interpret, the MIBI-Tc 99 m was true positive. In 3 false positive X-ray M procedures, the scintigraphy was true negative but, whatever the size of the tumor the best sensitivity was obtained with X-ray M (71%) and E C (70%) while for MIBI Tc-99 m, sensitivity was less (67%). MIBI-Tc 99 m appears to be a complementary tool in cases of difficulty of interpretation of mammography particularly in case of recurrence of the disease

Radiation-dosimetry and chemical-toxicity considerations for 99Tc

International Nuclear Information System (INIS)

Coffey, J.L.; Hayes, R.L.; Rafter, J.J.; Watson, E.E.; Carlton, J.E.

1982-01-01

Technetium-99 (T/sub 1/2/ = 2.13 x 10 5 y) is produced in the fission of 235 U and 239 Pu. Technitium-99 has been found to contaminate some areas of the uranium re-enrichment process. ICRP-30 Part 2 gives the Annual Limit on Intake (ALI) for 99 Tc as 2 x 10 8 Bq (5.4 mCi) for class D inhaled material (IC80). The ICRP states clearly that ALIs are based on radiation risk only and that chemical toxicity is not considered (IC79). No data were found on the chemical toxicity of 99 Tc, possibly because there are no stable isotopes of technetium with which to study the toxicity, although, because of its long T/sub 1/2/, 99 Tc can, for all practical purposes, be considered stable. The ALI values for 99 Tc are based on data obtained using high specific activity /sup 99m/Tc (T/sub 1/2/ = 6 h) and /sup 95m/Tc (T/sub 1/2/ = 61 days). Since the specific activities of 99 Tc and Na 99 TcO 4 are quite low (17 mCi/g and 9 mCi/g, respectively) and 99 Tc is available in abundant supply, we have attempted to assess the relative radiation and chemical hazards that are associated with this radionuclide. The approach in this study was (1) to study the effect of chemical dose on the whole body retention of 99 Tc sodium pertechnetate in rats and to relate these effects to the radiation dose and the ALI and (2) to compare the chemical toxicity of 99 Tc sodium pertechnetate with the ALI at different chemical dose levels

Improved brain scan specificity utilizing /sup 99m/Tc-pertechnetate and /sup 99m/Tc(Sn)-diphosphonate

International Nuclear Information System (INIS)

Fischer, K.C.; McKusick, K.A.; Pendergrass, H.P.; Potsaid, M.S.

1975-01-01

Each of 36 patients was studied with two separate brain scans performed sequentially after the injection of 20 mCi of /sup 99m/Tc-pertechnetate or 20 mCi of /sup 99m/Tc(Sn)-diphosphonate. The resulting scans were qualitatively compared, and lesion-to-nonlesion ratios of activity determined. Diagnoses were established by clinical criteria and were supported in the majority of cases by computerized axial tomography or roentgen angiography or both. Histologic confirmation was available in five cases of tumor and in the single cases of subdural hematoma and cerebral abscess. Of 22 cerebral infarctions, 15 were better demonstrated with /sup 99m/Tc-(Sn)-diphosphonate than with /sup 99m/Tc-pertechnetate. Of the seven remaining cases, three were visualized equally well with each agent, and three were better demonstrated with /sup 99m/Tc-pertechnetate. One was not seen with either agent. Of the 12 tumors, 11 were visualized better with /sup 99m/Tc-pertechnetate than with /sup 99m/Tc(Sn)-diphosphonate while in one case the lesion was seen equally as well with both agents. In no case was a lesion definitely seen with one radio- pharmaceutical and not with the other. These results indicate that this dual method is helpful in differentiating gliomas and metastases from cerebral infarctions. (U.S.)

The usefulness of 99mTc-MIBI in the detection of active pulmonary tuberculosis

International Nuclear Information System (INIS)

Lee, H. J.; Jeon, D. S.; Yoo, S. D.; Lee, M. K.; Park, S. K.; Kim, S. J.; Kim, I. J.; Kim, Y. K.

1998-01-01

The use of radiopharmaceuticals in evaluation of pulmonary tuberculosis may help to resolve difficult diagnostic problems such as discordance between sputum examinations and chest roentgenographic findings. We investigated the usefulness of 99m Tc-methoxyisobutylisonitrile (MIBI) scintigraphy in the detection of active pulmonary tuberculosis. Forty-six patients with suspected active pulmonary tuberculosis were studied with sputum smear of AFB, sputum AFB culture, chest X-ray and MIBI scan. MIBI image was obtained 15 and 60 min after intravenous injection of 370MBq(10mCi) 99m Tc-MIBI. In 16 patients of them Ga scans were performed in addition to MIBI scan. Repeated MIBI scans were done in 7 patients with active pulmonary tuberculosis after 4∼6 months of antituberculous chemotherapy. Thirty-two patients were confirmed as active tuberculosis by sputum culture. Sensitivity of MIBI scan to active tuberculosis was 87.5%(28/32) and MIBI findings were negative in all of 14 patients with inactive disease. Focal uptake of MIBI was dense in the area that was strongly suggested active tuberculous lesions by chest roentgenogram. There was no discordance between MIBI and Ga image in 16 patients. But the uptake areas of Ga images were broader than that of MIBI images. After 4∼6 months of antituberculous treatment all repeated MIBI scans revealed negative findings except 1 patient with persistent active pulmonary tuberculosis due to drug resistance. MIBI scan could be used in the detection of active pulmonary tuberculosis as a useful noninvasive diagnostic tool

Efficacy of (99m)Tc-EDDA/HYNIC-TOC SPECT/CT scintigraphy in Graves' ophthalmopathy.

Science.gov (United States)

Zhao, Rong; Wang, Jiang; Deng, Jinglan; Yang, Weidong; Wang, Jing

2012-01-01

The aim of this study was to investigate the predictive role of the orbital somatostatin receptor scintigraphy with (99m)Tc-EDDA/HYNIC-TOC ((99m)Tc-TOC) to detect clinical stage of Graves' ophthalmopathy and the response to corticosteroid therapy. The subjects of the experiment were 46 patients with Graves' ophthalmopathy (GO) and four volunteers without eye disease or GO as the normal group (NG). Single photon emission computed tomography (SPECT), computed tomography (CT) and the left and right lateral position planar imaging of the heads of the all subjects were obtained 4 h after the intravenous injection of 555 MBq of (99m)Tc-TOC. The (99m)Tc-TOC SPECT/CT was repeated 3 months later. 35 (35/46) patients were received corticosteroid therapy (prednisolone, 10 mg po tid ) for 3 months, however, the other 11 patients as control groups did not receive any treatment. The treatment effect was evaluated both by the orbital (99m)Tc-TOC uptake and NOSPECS. A significant decrease in the O/OC ratio was observed in 22 GO patients between pre- and post-treatment (1.64 ± 0.13 vs. 1.21 ± 0.09, P TOC scintigraphy is a feasible technique to estimate the Graves' ophthalmopathy activity and predict the response to subsequent corticosteroid therapy in GO patients. The technique could be a useful tool for physicians not familiar with CAS determination.

miR-21 regulates triglyceride and cholesterol metabolism in non-alcoholic fatty liver disease by targeting HMGCR.

Science.gov (United States)

Sun, Chuanzheng; Huang, Feizhou; Liu, Xunyang; Xiao, Xuefei; Yang, Mingshi; Hu, Gui; Liu, Huaizheng; Liao, Liangkan

2015-03-01

Non-alcoholic fatty liver disease (NAFLD) has emerged as a public health issue with a prevalence of 15-30% in Western populations and 6-25% in Asian populations. Certain studies have revealed the alteration of microRNA (miRNA or miR) profiles in NAFLD and it has been suggested that miR-21 is associated with NAFLD. In the present study, we measured the serum levels of miR-21 in patients with NAFLD and also performed in vitro experiments using a cellular model of NAFLD to further investigate the effects of miR-21 on triglyceride and cholesterol metabolism. Furthermore, a novel target through which miR-21 exerts its effects on NAFLD was identified. The results revealed that the serum levels of miR-21 were lower in patients with NAFLD compared with the healthy controls. In addition, 3-hydroxy-3-methylglutaryl-co-enzyme A reductase (HMGCR) expression was increased in the serum of patients with NAFLD both at the mRNA and protein level. To mimic the NAFLD condition in vitro, HepG2 cells were treated with palmitic acid (PA) and oleic acid (OA). Consistent with the results obtained in the in vivo experiments, the expression levels of miR-21 were decreased and those of HMGCR were increased in the in vitro model of NAFLD. Luciferase reporter assay revealed that HMGCR was a direct target of miR-21 and that miR-21 exerted an effect on both HMGCR transcript degradation and protein translation. Furthermore, the results from the in vitro experiments revealed that miR-21 decreased the levels of triglycerides (TG), free cholesterol (FC) and total cholesterol (TC) in the PA/OA-treated HepG2 cells and that this effect was attenuated by HMGCR overexpression. Taken together, to the best of our knowledge, the present study is the first to report that miR-21 regulates triglyceride and cholesterol metabolism in an in vitro model of NAFLD, and that this effect is achieved by the inhibition of HMGCR expression. We speculate that miR-21 may be a useful biomarker for the diagnosis and

Comparative study of 99Mo/99mTc generators at base of synthesized gels starting from activation and fission 99Mo

International Nuclear Information System (INIS)

Lopez M, I.Z.; Monroy G, F.; Rivero G, T.; Rojas N, P.

2007-01-01

The 99m Tc is used for diagnostic and therapy. It is produced starting from 99 Mo, absorbed in chromatographic columns, loaded with alumina that absorb only 0.2% of 99 Mo with high specific activities of 99 Mo, obtained from the 235 U fission. Given these conditions and limitations, new preparation procedures of 99 Mo/ 99m Tc generators, its have been developed, using zirconium molybdates gels that incorporates until 30% of 99 Mo, conserve similar characteristics of quality and purity that the traditional generator. The radiochemical characteristics of the 99m Tc elution, depend strongly on the gel preparation conditions. In particular, the present work has by object to determine the influence of the 99 Mo used type, fission or activation product, during the gels synthesis, as well as the used air flow for the agitation in the gels preparation and its influence in the 99 Mo/ 99m Tc generators quality. When diminishing the flow of agitation air the efficiency it increases and in the radionuclide purity of the eluates and when using 99 Mo from fission for the gels production it increases in an important way the elutriation efficiency, the radiochemical and radionuclide purity of the 99m Tc eluates. (Author)

High-dose vitamin D in Addison's disease regulates T-cells and monocytes: A pilot trial.

Science.gov (United States)

Penna-Martinez, Marissa; Filmann, Natalie; Bogdanou, Dimitra; Shoghi, Firouzeh; Huenecke, Sabine; Schubert, Ralf; Herrmann, Eva; Koehl, Ulrike; Husebye, Eystein S; Badenhoop, Klaus

2018-05-01

On the basis of the immunomodulatory actions of vitamin D (VD), we investigated the effects of high-dose VD therapy over a 3 mo period on the immune response in patients with Addison's disease (AD). This randomized, controlled, crossover trial included 13 patients with AD who received either cholecalciferol (4000 IU/d) for 3 mo followed by 3 mo placebo oil or the sequential alternative placebo followed by verum. Glucocorticoid replacement doses remained stable. The primary outcome measures were changes in 25-hydroxyvitamin D3 (25(OH)D 3 ) levels and immune cells including T helper cells (Th; CD3 + CD4 + ), late-activated Th cells (CD3 + CD4 + HLA-DR + ), regulatory T cells (CD3 + CD4 + CD25 bright CD127 dim/neg ), cytotoxic T cells (Tc; CD3 + CD8 + ), late-activated Tc cells (CD3 + CD8 + HLA-DR + ), and monocytes. The explorative analysis included the correlation of changes with VD-related gene polymorphisms and 21-hydroxylase antibody titers. Ten of 13 patients (77%) were VD deficient. Median 25(OH)D 3 concentrations increased significantly to 41.5 ng/ml (median changes: 19.95 ng/ml; P = 0.0005) after 3 mo of cholecalciferol treatment. Within the T-cells, only the late-activated Th (median changes: 1.6%; P = 0.02) and late-activated Tc cells (median changes: 4.05%; P = 0.03) decreased, whereas monocytes (median changes: 1.05%; P = 0.008) increased after VD therapy. T-cell changes were associated with two polymorphisms (CYP27B1-rs108770012 and VDR-rs10735810), but no changes in the 21-hydroxylase antibody titers were observed. Three months of treatment with cholecalciferol achieved sufficient 25(OH)D 3 levels and can regulate late-activated T-cells and monocytes in patients with AD. Explorative analysis revealed potential genetic contributions. This pilot trial provides novel insights about immunomodulation in AD. Copyright © 2017 Elsevier Inc. All rights reserved.

VGF-derived peptide, TLQP-21, regulates food intake and body weight in Siberian hamsters.

Science.gov (United States)

Jethwa, Preeti H; Warner, Amy; Nilaweera, Kanishka N; Brameld, John M; Keyte, John W; Carter, Wayne G; Bolton, Neil; Bruggraber, Michael; Morgan, Peter J; Barrett, Perry; Ebling, Francis J P

2007-08-01

The Siberian hamster survives winter by decreasing food intake and catabolizing abdominal fat reserves, resulting in a sustained, profound loss of body weight. VGF gene expression is photoperiodically regulated in the hypothalamus with significantly higher expression in lean Siberian hamsters. The aim of this study was to investigate the role of VGF in regulating these seasonal cycles by determining the effects of a VGF-derived peptide (TLQP-21) on food intake and body weight. Acute intracerebroventricular administration of TLQP-21 decreased food intake, and chronic treatment caused a sustained reduction in food intake and body weight and decreased abdominal fat depots. Behavioral analysis revealed that TLQP-21 reduced meal size but not the frequency of feeding bouts, suggesting a primary action on satiety. Hamsters treated with TLQP-21 lost a similar amount of weight as a pair-fed group in which food intake was matched to that of the TLQP-21-treated group. Central or peripheral treatment with TLQP-21 did not produce a significant effect on resting metabolic rate. We conclude that the primary action of TLQP-21 is to decrease food intake rather than increase energy expenditure. TLQP-21 treatment caused a decrease in UCP-1 mRNA in brown adipose tissue, but hypothalamic expression of orexigenic and anorexigenic neuropeptide genes remained unchanged after TLQP-21 treatment, although compensatory increases in NPY and AgRP mRNA were observed in the pair-fed hamsters. The effects of TLQP-21 administration are similar to those in hamsters in short days, suggesting that increased VGF activity may contribute to the hypophagia that underlies the seasonal catabolic state.

The new 99mTc myocardial perfusion imaging agents: 99mTc-sestamibi and 99mTc-teboroxime

International Nuclear Information System (INIS)

Berman, D.S.; Kiat, H.; Maddahi, J.

1991-01-01

The two new 99m (99mTc) labeled myocardial perfusion agents, 99mTc-Sestamibi and 99mTc-Teboroxime, are now available for routine clinical application. Both agents allow assessment of ejection fraction by the first-pass technique at rest or during exercise, thus providing additional information not available with thallium-201. 99mTc-Sestamibi has long myocardial residence time, as well as adequate myocardial extraction, providing images of higher count density and superior quality compared with thallium-201. 99mTc-Teboroxime has excellent myocardial uptake characteristics but is cleared very rapidly from the myocardium. Both tracers have shown results similar to those obtained with thallium-201 for detection of coronary artery disease and the assessment of defect reversibility. 99mTc-Sestamibi studies using the rest/stress imaging sequence can be accomplished in approximately 5 hours; studies using dual-isotope imaging (rest thallium-201 and stress 99mTc-Sestamibi injection) can be completed in 1 to 2 hours. Gated stress images can be performed with 99mTc-Sestamibi, providing simultaneous information of myocardial perfusion at stress and resting wall motion or thickening and allowing rapid differentiation of ischemic from infarcted tissue. Because of its slow myocardial clearance and absence of redistribution, 99mTc-Sestamibi allows uncoupling of the time of injection from the time of imaging and thus can be valuable in the evaluation of acute myocardial infarction and outcome of thrombolytic therapy. With 99mTc-Teboroxime, rapid serial studies are feasible. Pharmacologic stress and rest studies with 99mTc-Teboroxime single photon emission computed tomography potentially can be completed in under 30 minutes. 73 references

Cytological effects of Tc on young soybean plants

International Nuclear Information System (INIS)

Neel, J.W.; Onasch, M.A.

1989-01-01

Soybean seedlings (Glycine max cv. Williams) were exposed for 24 to 67 h to 99 TcO 4 - (Tc) at various concentrations in dilute culture solution. Reduced primary leaf midrib length was observed with 67-h exposures to greater than or equal to 6.0 mu M Tc. Cellular effects were consistently observed by a light microscope after 43-h or longer exposure to 6.6 microM Tc and higher concentrations. At lower Tc levels, abnormal cells were interspersed among cells of normal appearance. Abnormal cells displayed blockshaped nuclei which were more densely stained by Harris' hematoxylineosin Y than controls; such cells frequently demonstrated incipient plasmolysis. The number of affected cells increased with dose; both nuclei and cytoplasm demonstrated greater staining intensity and more severe plasmolysis at higher levels. At levels of greater than or equal to 13.2 Tc, cellular damage was extensive. Cells were reduced in size and were highly plasmolysed; cell walls were distorted, and intercellular spaces were reduced or became nonexistent. Mitotic activity was observed at Tc levels less than or equal to 9.9 microM. Observed Tc cellular effects are attributed principally to the alteration of membrane permeability characteristics

Comparison of carrier-added [99mTc] EDTMP and carrier-free preparations of [99mTc] EDTMP and [99mTc] DPD

International Nuclear Information System (INIS)

Krcal, A.; Kletter, K.; Dudczak, R.; Pirich, C.; Mitterhauser, M.

2002-01-01

Full text: High uptake of bone-seeking radiopharmaceuticals in malignant bone lesions is a prerequisite for adequate bone scanning. Visual image analysis is impaired due to high soft-tissue activity with currently available [ 99m Tc]-EDTMP-kits. This study aimed to compare carrier-added [ 99m Tc]-EDTMP with carrier-free [ 99m Tc]-EDTMP and [ 99m Tc]-DPD preparations in clinical routine. 15 μg and 150 μg perrhenic acid respectively were added to [ 99m Tc]-pertechnetate (>6 GBq in 3 ml phys. saline). The solution was then transferred into a vial, containing 1 mg of EDTMP, 3.6 mg stannous(II)chloride and 10 mg ascorbic acid under inert conditions. Under vigorous stirring the reaction mixture was heated to 45 o C for 10 min. After cooling down to room temperature the labelling mixture was sterile filtrated (millipore 0.22 μm). Quality control was performed using radio-ITLC (Whatman SG; acetone or ethanol: R f perrhenate/pertechnetate 0.87, colloid/product 0.05; phys. saline: R f colloid 0.00, perrhenate/pertechnetate and product 0.9) allowing rapid and efficient assessment of the product. Carrier free [ 99m Tc]-EDTMP and [ 99m Tc]-DPD were prepared according to instructions of the manufacturer. Clinical studies were performed in 29 patients according to a routine bone scanning protocol by injecting 700-800 MBq of the respective tracer and whole body imaging 3 h thereafter. Radiochemical purity and radiochemical yield relied on various parameters such as concentration of carrier and reducing agent and reaction conditions (pH, reaction time, temperature). Means of the labelling yield were 22 % for the preparation using 150 μg of carrier (5 preparations), 80 % for the preparation using 15 μpg of carrier (10 preparations) and 91 % for the carrier free products (5 preparations). Radiochemical purity was >96 % in all experiments. Colloid was formed in very low amounts, and was completely removed by sterile filtration. In clinical studies quantitative analysis

Mismatched uptake of Tc-99m-ECD and Tc-99m-HMPAO in subacute cerebral infarction: Tc-99m-ECD for viability and Tc-99m-HMPAO for flow restoration

Energy Technology Data Exchange (ETDEWEB)

Lee, D. S.; Hyun, I. Y.; Kim, S. K. [College of Medicine, Seoul National Univ., Seoul (Korea, Republic of)] [and others

1997-07-01

Tc-99m-HMPAO reflects tissue perfusion but Tc-99m-ECD uptake is affected by tissue viability in addition to tissue perfusion which the varied state of cellular retention of Tc-99m-ECD reflects. Luxuriously perfused area on Tc-99m-HMPAO SPECT implies that this cortex was already reperfused either spontaneously or after thrombolysis and that accompanied paralysis of vascular reactivity in those zones warms progressive deterioration. We tried to find out if we can use sequential Tc-99m-ECD/Tc-99m-HMPAO SPECT to reveal cortical perfusion and severity and range of risky areas of cerbral cortex despite reperfusion in sub-acute infarction. In 13 patients (M ; F =7 : 6, mean age 57 (range: 26-84)) with cortical (n=12) and basal ganglia infarction (1), we performed sequential Tc-99m-ECD/Tc-99m-HMPAO SPECT at the same position. At first, 555 MBq of Tc-99m-ECD was injected and imaged and then 1110 MBq of Tc-99m-HMPAO was injected again and imaged with the patients in situ, and the first image (Tc-99m-ECD) and the subtracted image (2nd- 1st : Tc-99m-HMPAO) were compared slice by slice. Study was done from 3 days to 31 days (16{+-}9) after ictus. Tc-99m-ECD uptake was always less than or equal to Tc-99m-HMPAO uptake at the lesion in all cases. Luxury perfusion was prominent in four patients. Mismatched uptake was found in 10 patients. Severity of mismatch showed diverse spectrum and was ranged from total middle cerebral artery territory (1 case) to peripheral thin zones around infarction (2 cases). The other 7 showed intermediate amount of tissues with mismatch , i.e., Tc-99m-ECD defects where Tc-99m-HMPAO uptake is in part increased, normal or decreased. Upon discharge, patients having more uptake with Tc-99m-ECD predicted improvement. Patients having mismatched uptake went dichotomous way. In conclusion, Tc-99m-ECD/Tc-99m-HMPAO sequential SPECT is feasible and reveal both tissue perfusion (Tc-99m-HMPAO ) and discrepant Tc-99m-ECD uptake probably reflecting viability in acute

Pharmaceutical design and pharmacological characterization of Tc99m [99mTc] labelled somatostatin and gastrin analogues

International Nuclear Information System (INIS)

Guggenberg, E. von

2004-10-01

The development of regulatory peptide analogues radiolabelled with 99m Tc is of great interest for nuclear medicine applications, as 99m Tc shows very favourable imaging characteristics, such as low radiation burden to the patient, optimal image quality in SPECT, one-day-acquisition-protocol, availability on demand and cost effectiveness. In this work the principles of pharmaceutical design and preclinical pharmacological characterization of regulatory peptide analogues labelled with 99m Tc with possible application in tumour diagnosis are described. [ 99m Tc-EDDA-HYNIC0,Tyr3]octreotide ( 99m Tc-EDDA-HYNIC-TOC) is a promising new radiopharmaceutical with the potential to replace [ 111 In-DTPA0]octreotide in receptor scintigraphy of somatostatin receptor-positive tumours. Radiolabelling at high labelling yields and high specific activities could be obtained applying a coligand exchange labelling approach from tricine for EDDA under optimized conditions of pH, EDDA and stannous ion concentration. The resulting complex was characterized via HPLC, receptor binding and LC-MS. For the development of a freeze-dried kit formulation with long shelf-life, high stability of the final preparation and retained biological activity, the addition of bulking agent, the pH of the freeze-drying solution and the content of stannous chloride were of major importance. Different methods of radiochemical purity testing were evaluated to guarantee high quality of the preparation in a clinical setting, forming the basis for a further clinical evaluation of this promising new radiopharmaceutical. Radiolabelling of [D-Glu1]minigastrin (MG) with 99m Tc was studied applying two different labelling approaches. HYNIC-MG could be labelled using tricine and EDDA as coligands; and (Nalpha-His)Ac-MG was used as tridentate ligand for the 99m Tc carbonyl core. Stability experiments by HPLC analysis in PBS, serum, histidine- and cysteine-solutions as well as rat liver and kidney homogenates, receptor

Efficacy of 99mTc-EDDA/HYNIC-TOC SPECT/CT scintigraphy in Graves’ ophthalmopathy

Science.gov (United States)

Zhao, Rong; Wang, Jiang; Deng, Jinglan; Yang, Weidong; Wang, Jing

2012-01-01

The aim of this study was to investigate the predictive role of the orbital somatostatin receptor scintigraphy with 99mTc-EDDA/HYNIC-TOC (99mTc-TOC) to detect clinical stage of Graves’ ophthalmopathy and the response to corticosteroid therapy. The subjects of the experiment were 46 patients with Graves’ ophthalmopathy (GO) and four volunteers without eye disease or GO as the normal group (NG). Single photon emission computed tomography (SPECT), computed tomography (CT) and the left and right lateral position planar imaging of the heads of the all subjects were obtained 4 h after the intravenous injection of 555 MBq of 99mTc-TOC. The 99mTc-TOC SPECT/CT was repeated 3 months later. 35 (35/46) patients were received corticosteroid therapy (prednisolone, 10 mg po tid ) for 3 months, however, the other 11 patients as control groups did not receive any treatment. The treatment effect was evaluated both by the orbital 99mTc-TOC uptake and NOSPECS. A significant decrease in the O/OC ratio was observed in 22 GO patients between pre- and post-treatment (1.64 ± 0.13 vs. 1.21 ± 0.09, P < 0.05). There were neither significant difference of the O/OC ratio in 13 GO patients between pre- and post-treatment periods, nor significant difference in the 9 (9/11) patients before and after three months. Orbital 99mTc-TOC scintigraphy is a feasible technique to estimate the Graves’ ophthalmopathy activity and predict the response to subsequent corticosteroid therapy in GO patients. The technique could be a useful tool for physicians not familiar with CAS determination. PMID:23133815

Rab21, a Novel PS1 Interactor, Regulates γ-Secretase Activity via PS1 Subcellular Distribution.

Science.gov (United States)

Sun, Zhenzhen; Xie, Yujie; Chen, Yintong; Yang, Qinghu; Quan, Zhenzhen; Dai, Rongji; Qing, Hong

2018-05-01

γ-Secretase has been a therapeutical target for its key role in cleaving APP to generate β-amyloid (Aβ), the primary constituents of senile plaques and a hallmark of Alzheimer's disease (AD) pathology. Recently, γ-secretase-associating proteins showed promising role in specifically modulating APP processing while sparing Notch signaling; however, the underlying mechanism is still unclear. A co-immunoprecipitation (Co-IP) coupled with mass spectrometry proteomic assay for Presenilin1 (PS1, the catalytic subunit of γ-secretase) was firstly conducted to find more γ-secretase-associating proteins. Gene ontology analysis of these results identified Rab21 as a potential PS1 interacting protein, and the interaction between them was validated by reciprocal Co-IP and immunofluorescence assay. Then, molecular and biochemical methods were used to investigate the effect of Rab21 on APP processing. Results showed that overexpression of Rab21 enhanced Aβ generation, while silencing of Rab21 reduced the accumulation of Aβ, which resulted due to change in γ-secretase activity rather than α- or β-secretase. Finally, we demonstrated that Rab21 had no effect on γ-secretase complex synthesis or metabolism but enhanced PS1 endocytosis and translocation to late endosome/lysosome. In conclusion, we identified a novel γ-secretase-associating protein Rab21 and illustrate that Rab21 promotes γ-secretase internalization and translocation to late endosome/lysosome. Moreover, silencing of Rab21 decreases the γ-secretase activity in APP processing thus production of Aβ. All these results open new gateways towards the understanding of γ-secretase-associating proteins in APP processing and make inhibition of Rab21 a promising strategy for AD therapy.

Evaluation of breast MIBI-Tc 99 m scintigraphy for the detection of breast cancer

Energy Technology Data Exchange (ETDEWEB)

Loriaux, C.; Baeyens, L.; Paternot, J.; Martin, P.; Verhas, M. [Hospital Universitaire Brugmann, Bruxelles (Belgium). Service de Medecine Nucleaire et Clinique de Senologie

1997-12-31

Full text. The aim of the work was to appreciate the contribution of MIBI-Tc 99 m scintigraphy for the detection of breast cancer and to situate this procedure in comparison with mammography 5 (X-ray M) and echography (E C). 21 patients presenting suspected lesion on clinical evaluation/or mammography were referred to the department for breast MIBI-Tc 99 m scintigraphy. 10 min after IV injection of MIBI-Tc 99 m 3 planar scan were realized with a present time of 10 min. The whole investigation including X-ray and surgical procedures were performed within 15 days. The pathologic findings were: 21 malignant lesion (18 canal cancers, 3 lobular cancers), 4 benign lesions (1 fibroadenoma, 2 granuloma, 1 fibrocystic disease). Lesions were bilateral in 3 cases and there was 1 bifocal lesion. 17 tumours were palpable and 8 not palpable, 10 lesion were <1 cm (40%), 9 were between 1,1 and 2,5 cm (36%) and 7 were >2,5 cm (24%). The overall sensitivity and specificity for MIBI-Tc 99 m were 67% and 75% respectively. For the group of palpable tumours, sensitivity of MIBI-Tc 99 m was 86%. In three cases, the X-ray M was difficult to interpret, the MIBI-Tc 99 m was true positive. In 3 false positive X-ray M procedures, the scintigraphy was true negative but, whatever the size of the tumor the best sensitivity was obtained with X-ray M (71%) and E C (70%) while for MIBI Tc-99 m, sensitivity was less (67%). MIBI-Tc 99 m appears to be a complementary tool in cases of difficulty of interpretation of mammography particularly in case of recurrence of the disease

Validation of curve-fitting method for blood retention of 99mTc-GSA. Comparison with blood sampling method

International Nuclear Information System (INIS)

Ha-Kawa, Sang Kil; Suga, Yutaka; Kouda, Katsuyasu; Ikeda, Koshi; Tanaka, Yoshimasa

1997-01-01

We investigated a curve-fitting method for the rate of blood retention of 99m Tc-galactosyl serum albumin (GSA) as a substitute for the blood sampling method. Seven healthy volunteers and 27 patients with liver disease underwent 99m Tc-GSA scanning. After normalization of the y-intercept as 100 percent, a biexponential regression curve for the precordial time-activity curve provided the percent injected dose (%ID) of 99m Tc-GSA in the blood without blood sampling. The discrepancy between %ID obtained by the curve-fitting method and that by the multiple blood samples was minimal in normal volunteers 3.1±2.1% (mean±standard deviation, n=77 sampling). Slightly greater discrepancy was observed in patients with liver disease (7.5±6.1%, n=135 sampling). The %ID at 15 min after injection obtained from the fitted curve was significantly greater in patients with liver cirrhosis than in the controls (53.2±11.6%, n=13; vs. 31.9±2.8%, n=7, p 99m Tc-GSA and the plasma retention rate for indocyanine green (r=-0.869, p 99m Tc-GSA and could be a substitute for the blood sampling method. (author)

TcNPR3 from Theobroma cacao functions as a repressor of the pathogen defense response.

Science.gov (United States)

Shi, Zi; Zhang, Yufan; Maximova, Siela N; Guiltinan, Mark J

2013-12-06

Arabidopsis thaliana (Arabidopsis) NON-EXPRESSOR OF PR1 (NPR1) is a transcription coactivator that plays a central role in regulating the transcriptional response to plant pathogens. Developing flowers of homozygous npr3 mutants are dramatically more resistant to infection by the pathogenic bacterium Pseudomonas syringae, suggesting a role of NPR3 as a repressor of NPR1-mediated defense response with a novel role in flower development. We report here the characterization of a putative NPR3 gene from the tropical tree species Theobroma cacao (TcNPR3). Like in Arabidopsis, TcNPR3 was constitutively expressed across a wide range of tissue types and developmental stages but with some differences in relative levels compared to Arabidopsis. To test the function of TcNPR3, we performed transgenic complementation analysis by introducing a constitutively expressing putative TcNPR3 transgene into an Arabidopsis npr3 mutant. TcNPR3 expressing Arabidopsis plants were partially restored to the WT pathogen phenotype (immature flowers susceptible to bacterial infection). To test TcNPR3 function directly in cacao tissues, a synthetic microRNA targeting TcNPR3 mRNA was transiently expressed in cacao leaves using an Agrobacterium-infiltration method. TcNPR3 knock down leaf tissues were dramatically more resistance to infection with Phytophthora capsici in a leaf bioassay, showing smaller lesion sizes and reduced pathogen replication. We conclude that TcNPR3 functions similar to the Arabidopsis NPR3 gene in the regulation of the cacao defense response. Since TcNPR3 did not show a perfect complementation of the Arabidopsis NPR3 mutation, the possibility remains that other functions of TcNPR3 remain to be found. This novel knowledge can contribute to the breeding of resistant cacao varieties against pathogens through molecular markers based approaches or biotechnological strategies.

Synthesis, characterization and biodistribution of technetium complexes (99Tc/99mTc) with 2-amino-2-deoxy-D-hexose oximes

International Nuclear Information System (INIS)

Steinmetz, H.J.

1993-05-01

In the present work, the synthesis and isolation of isomeric complexes of technetium ( 99 Tc/ 99m Tc) with the 2-amino-2-deoxy-D-hexoses D-glucose aminoxime, D-galactose aminoxime and D-mannose aminoxime, the characterization of the complexes as 99 Tc compounds, and bio-distribution studies on the analogous 99m Tc complexes have been untertaken. As a first step, the free ligands were synthesized and identified using elemental analysis, infra-red and nuclear magnetic resonance spectroscopy and FAB mass spectroscopy. In the bio-distribution studies on the 99m Tc complexes of D-glucose aminoxime and of D-galactose aminoxime in NMRI mice, significant short-term accumulation of 99m Tc activity in heart muscle could be detected, which may be attributed to a biochemical transport mechanism. Uptake in the lungs and the liver was found, but a more significant uptake was observed in the kidneys, where the complexes were rapidly secreted in proportion to their concentration in the blood plasma. (orig./BBR) [de

Preparation of 99mTc-PQQ and preliminary biological evaluation for the NMDA receptor

International Nuclear Information System (INIS)

Yanyan Kong; Xingqin Zhou; Guoxian Cao; Xijie Xu; Meifen Zou; Xiaofeng Qin; Rongjun Zhang

2011-01-01

Pyrroloquinoline quinone (PQQ), an essential nutrient, antioxidant, redox modulator and nerve growth factor found in a class of enzymes called quinoproteins, was labeled with 99m Tc by using stannous fluoride (SnF2) method. Radiolabeling qualification, quality control and characterization of 99m Tc-PQQ and its biodistribution studies in mice were performed and discussed. Effects of pH values, temperature, time and reducing agents concentration on the radiolabeling yield were investigated. The quality control procedure of 99m Tc-PQQ was determined by thin layer chromatography (TLC), radio high-performance liquid chromatography (RHPLC) and paper electrophoresis methods. The average radiolabeling yield was 94 ± 1% under optimum conditions of 0.99 mg of PQQ, 30 μg of SnF 2 , 0.5 mg of ethylenediaminetetraacetic acid disodium salt (EDTA-2Na) and 18.5 MBq of Na 99m TcO 4 at pH 6 and 25 deg C with a response volume of 1 ± 0.1 mL. 99m Tc-PQQ was stable and anionic. Lipid-water partition coefficient of 99m Tc-PQQ was -1.49 ± 0.16. The pharmacokinetics parameters of 99m Tc-PQQ were t 1/2α 18.16 min, t 1/2β = 100.45 min, K 12 = 0.013 min -1 , K 21 = 0.017 min -1 , K e 0.016 min -1 , AUC (area under the curve) = 1040.78 ID% g -1 min and CL (plasma clearance) = 0.096 mL min -1 . The dual-exponential equation was Y 10.88e -0.038t + 5.21e -0.0069t . The biodistribution of 99m Tc-PQQ was studied in ICR (Institute for Cancer Research 7701 Burhelme Are., Fox Chase, Philadelphia, PA 1911 USA) mice. In vitro autoradiographic studies clearly showed that the 99m Tc-PQQ radioactivity accumulated predominantly in the hippocampus and cortex, which had a high density of N-methyl-d-aspartate Receptor (NMDAR). The enrichment can be blocked by NMDAR redox modulatory site antagonists-ebselen (EB) and 99m Tc-PQQ is therefore a promising candidate for the molecular imaging of NMDAR. To date, however, there have been no studies characterizing 99m Tc-PQQ. (author)

Evaluation of '99Mo presence in eluates of 99mTc used in nuclear medicine

International Nuclear Information System (INIS)

Ribeiro, Bianca da Silva

2010-01-01

Tc-99m is used for diagnostic imaging in nuclear medicine through SPECT technique. It is obtained by the elution of 99 Mo/ 99m Tc generators. During the elution process 99 Mo can be extracted becoming a radionuclidic impurity. One of the quality parameters of the eluate is the radionuclidic purity, MBT (molybdenum break through), defined as the ratio between 99 Mo and 99m Tc activities in the eluate. The North-American and European pharmacopoeias restrict the 99 Mo content, respectively, in 0.015 e 0.1% and, according to the International Atomic Energy Agency (IAEA), the activity ratio at the moment of administration of the radiopharmaceutical to the patient, should not exceed 0.015%. In Brazil, the control of such parameter is not obliged in official regulations. Thus, the objective of this work is to evaluate the occurrence of 99 Mo in 99m Tc eluates. It was initially optimized a methodology to determine the activity of 99 Mo in eluate samples. Efficiency curves were obtained for a NaI (Tl) 8'' x 4'' scintillation detector installed at the In Vivo Monitoring Laboratory (LABMIV-IRD). The methodology has been validated through the measurement of a 99 Mo standard liquid source calibrated at the National Metrology Laboratory for Ionizing Radiation (LNMRI-IRD). The samples analyzed in this work were gently supplied by 5 Nuclear Medicine Clinics located in the city of Rio de Janeiro. The activities of 99 mTc and 99 Mo in those samples have been measured respectively at the clinics and at the LABMIV. By applying a standardized methodology, the ration between the activities were calculated. The results show that 147 out of 174 samples presented 99 Mo activities above the minimum detectable activity of the technique. On the other hand, only 2 out of 147 samples surpassed the MBT limit suggested by the IAEA and have been detected in samples eluted from generators of 750 mCi. In one of the samples, eluted from a generator of 1000 mCi, the calculated MBT value was very close

Performance of TcI/TcVI/TcII Chagas-Flow ATE-IgG2a for universal and genotype-specific serodiagnosis of Trypanosoma cruzi infection.

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Glaucia Diniz Alessio

2017-03-01

Full Text Available Distinct Trypanosoma cruzi genotypes have been considered relevant for patient management and therapeutic response of Chagas disease. However, typing strategies for genotype-specific serodiagnosis of Chagas disease are still unavailable and requires standardization for practical application. In this study, an innovative TcI/TcVI/TcII Chagas Flow ATE-IgG2a technique was developed with applicability for universal and genotype-specific diagnosis of T. cruzi infection. For this purpose, the reactivity of serum samples (percentage of positive fluorescent parasites-PPFP obtained from mice chronically infected with TcI/Colombiana, TcVI/CL or TcII/Y strain as well as non-infected controls were determined using amastigote-AMA, trypomastigote-TRYPO and epimastigote-EPI in parallel batches of TcI, TcVI and TcII target antigens. Data demonstrated that "α-TcII-TRYPO/1:500, cut-off/PPFP = 20%" presented an excellent performance for universal diagnosis of T. cruzi infection (AUC = 1.0, Se and Sp = 100%. The combined set of attributes "α-TcI-TRYPO/1:4,000, cut-off/PPFP = 50%", "α-TcII-AMA/1:1,000, cut-off/PPFP = 40%" and "α-TcVI-EPI/1:1,000, cut-off/PPFP = 45%" showed good performance to segregate infections with TcI/Colombiana, TcVI/CL or TcII/Y strain. Overall, hosts infected with TcI/Colombiana and TcII/Y strains displayed opposite patterns of reactivity with "α-TcI TRYPO" and "α-TcII AMA". Hosts infected with TcVI/CL strain showed a typical interweaved distribution pattern. The method presented a good performance for genotype-specific diagnosis, with global accuracy of 69% when the population/prototype scenario include TcI, TcVI and TcII infections and 94% when comprise only TcI and TcII infections. This study also proposes a receiver operating reactivity panel, providing a feasible tool to classify serum samples from hosts infected with distinct T. cruzi genotypes, supporting the potential of this method for universal and genotype-specific diagnosis

Synthesis, Structure Elucidation, and Redox Properties of (superscript 99)Tc Complexes of Lacunary Wells-Dawson Polyoxometalates: Insights into Molecular (superscript 99)Tc-Metal Oxide Interactions

International Nuclear Information System (INIS)

McGregor, Donna; Burton-Pye, Benjamin P.; Howell, Robertha C.; Mbomekalle, Israel M.; Lukens, Wayne W. Jr.; Bian, Fang; Mausolf, Edward; Poineau, Frederic; Czerwinski, Kenneth R.; Francesconi, Lynn C.

2011-01-01

The isotope 99 Tc (β max , 293.7; half-life, 2.1 x 10 5 years) is an abundant product of uranium-235 fission in nuclear reactors and is present throughout the radioactive waste stored in underground tanks at the Hanford and Savannah River sites. Understanding and controlling the extensive redox chemistry of 99 Tc is important in identifying tunable strategies to separate 99 Tc from spent fuel and from waste tanks and, once separated, to identify and develop an appropriately stable waste form for 99 Tc. Polyoxometalates (POMs), nanometer-sized models for metal oxide solid-state materials, are used in this study to provide a molecular level understanding of the speciation and redox chemistry of incorporated 99 Tc. In this study, 99 Tc complexes of the (α 2 -P 2 W 17 O 61 ) 10- and (α 1 -P 2 W 17 O 61 ) 10- isomers were prepared. Ethylene glycol was used as a 'transfer ligand' to minimize the formation of TcO 2 · xH 2 O. The solution structures, formulations, and purity of TcVO(α 1 /α 2 -P 2 W 17 O 61 ) 7- were determined by multinuclear NMR. X-ray absorption spectroscopy of the complexes is in agreement with the formulation and structures determined from 31 P and 183 W NMR. Preliminary electrochemistry results are consistent with the EXAFS results, showing a facile reduction of the TcVO(α 1 -P 2 W 17 O 61 ) 7- species compared to the TcVO(α 2 -P 2 W 17 O 61 ) 7- analog. The α 1 defect is unique in that a basic oxygen atom is positioned toward the α 1 site, and the Tc V O center appears to form a dative metal-metal bond with a framework W site. These attributes may lead to the assistance of protonation events that facilitate reduction. Electrochemistry comparison shows that the ReV analogs are about 200 mV more difficult to reduce in accordance with periodic trends.

99mTc bone scanning agents preparation and chemical analysis of Tc(Sn)pyrophosphate, Tc(Sn)MDP and Tc(Sn)HMDP

International Nuclear Information System (INIS)

Kroesbergen, J.

1986-01-01

This thesis describes a comparison of the preparation, composition and properties of three bone scanning agents: 99m Tc(Sn)pyrophosphate, 99m Tc(Sn)MDP and 99m Tc(Sn)HMDP. This study has been performed for two reasons: First to investigate the preparation and composition of the radiopharmaceuticals as a function of experimental conditions. Together with previously reported results for 99m Tc(Sn)EHDP, obtained in a similar way, this enables to use well-defined preparations of the bone scanning agents. Secondly to gain an insight in the mechanism in which the agents behave 'in vivo'. Because the 'in vivo' process is too complicated to study directly, it seemed more appropriate to perform 'in vitro' investigations as simplifications of the 'in vivo' situation. 304 refs.; 26 figs.; 31 tabs

miR-21-3p is a positive regulator of L1CAM in several human carcinomas.

Science.gov (United States)

Doberstein, Kai; Bretz, Niko P; Schirmer, Uwe; Fiegl, Heidi; Blaheta, Roman; Breunig, Christian; Müller-Holzner, Elisabeth; Reimer, Dan; Zeimet, Alain G; Altevogt, Peter

2014-11-28

Expression of L1 cell adhesion molecule (L1CAM) occurs frequently in human cancers and is associated with poor prognosis in cancers such as ovarian, endometrial, breast, renal cell carcinoma and pancreatic ductal adenocarcinoma. L1CAM promotes cell motility, invasion, chemoresistance and metastasis formation. Elucidating genetic processes involved in the expression of L1CAM in cancers is of considerable importance. Transcription factors such as SLUG, β-catenin/TCF-LEF, PAX8 and VHL have been implicated in the re-activation of L1CAM in various types of cancers. There is increasing evidence that micro-RNAs can also have strong effects on gene expression. Here we have identified miR-21-3p as a positive regulator of L1CAM expression. Over-expression of miR-21-3p (miR-21*) but not the complementary sequence miR-21-5p (miR-21) could strongly augment L1CAM expression in renal, endometrial and ovarian carcinoma derived cell lines by an unknown mechanism involving transcriptional activation of the L1CAM gene. In patient cohorts from renal, endometrial and ovarian cancers we observed a strong positive correlation of L1CAM and miR-21-3p expressions. Although L1CAM alone was a reliable marker for overall and disease free survival, the combination of L1CAM and miR-21-3p expressions strongly enhanced the predictive power. Our findings shed new light on the complex regulation of L1CAM in cancers and advocate the use of L1CAM/miR-21-3p for diagnostic application. Copyright © 2014 Elsevier Ireland Ltd. All rights reserved.

The transport, hepatobiliary distribution and clearance of sup(99m)Tc-Sn-lidocaine iminodiacetic acid, sup(99m)Tc-Sn-Lida

International Nuclear Information System (INIS)

Noronha, O.P.D.; Sewatkar, A.B.; Ganatra, R.D.; Subramanian, G.

1977-01-01

Details are given of the preparation of stable sterile solutions of the radiopharmaceutical sup(99m)Tc-Sn-LIDA for use as a hepatobiliary scanning agent. Toxicity and survival studies in mice showed no untoward response even at a concentration of up to 210 mg/kg mouse, and the usual human dose is very much less than this. Tissue distribution studies in rats and mice showed a rapid decrease in liver activity with concomitant increase in gut activity. Scintiscans of a rabbit injected (i.v.) with 2.0 mCi of sup(99m)Tc-Sn-LIDA also showed extremely rapid excretion of the radiopharmaceutical. Sequential gamma camera images obtained 2 to 60 min after administration to overnight fasting normal human subjects revealed rapid liver uptake and gall bladder localization in about 20 min, followed by a gradual decrease in liver activity and increase in the activity in the intestinal tract. After about 40 min the liver has been washed-out of activity, leaving the gall bladder visible. sup(99m)Tc-Sn-LIDA is therefore an excellent hepatobiliary scanning agent. (U.K.)

Scavenging of Tc(V) formed by I.T. in 95mTcO4- solutions

International Nuclear Information System (INIS)

Ianoz, E.; Colin, M.; Kosinski, M.

1988-01-01

The chemical effects of the I.T. of 95m Tc in 95m TcO 4 - have been studied in chelating ligand solutions. At high pH and at high concentration of 1,4,8,11-tetraazacyclotetradecane and 1,4-dithia-8, 11-diazacyclotetradecane, the retention of 95g Tc is about 20% and the unretained 95g Tc appears preponderantly (ca. 73%) as [TcO 2 L] + complexes. In glucoheptonate solution, the 95g Tc retention remains practically the same (22%) but the unretained 95g Tc is found in high proportion (73%) as [TcObis(glucoheptonate)] - . The added ligands are very good scavengers for 95g Tc(V). A comparison is made between 95g Tc species formed by the I.T. in 95m TcO 4 - and 99m Tc species resulting from the chemical reduction of 99m TcO 4 - . (orig.)

Interleukin 21 Controls mRNA and MicroRNA Expression in CD40-Activated Chronic Lymphocytic Leukemia Cells.

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Loris De Cecco

Full Text Available Several factors support CLL cell survival in the microenvironment. Under different experimental conditions, IL21 can either induce apoptosis or promote CLL cell survival. To investigate mechanisms involved in the effects of IL21, we studied the ability of IL21 to modulate gene and miRNA expressions in CD40-activated CLL cells. IL21 was a major regulator of chemokine production in CLL cells and it modulated the expression of genes involved in cell movement, metabolism, survival and apoptosis. In particular, IL21 down-regulated the expression of the chemokine genes CCL4, CCL3, CCL3L1, CCL17, and CCL2, while it up-regulated the Th1-related CXCL9 and CXCL10. In addition, IL21 down-regulated the expression of genes encoding signaling molecules, such as CD40, DDR1 and PIK3CD. IL21 modulated a similar set of genes in CLL and normal B-cells (e.g. chemokine genes, whereas other genes, including MYC, TNF, E2F1, EGR2 and GAS-6, were regulated only in CLL cells. An integrated analysis of the miRNome and gene expression indicated that several miRNAs were under IL21 control and these could, in turn, influence the expression of potential target genes. We focused on hsa-miR-663b predicted to down-regulate several relevant genes. Transfection of hsa-miR-663b or its specific antagonist showed that this miRNA regulated CCL17, DDR1, PIK3CD and CD40 gene expression. Our data indicated that IL21 modulates the expression of genes mediating the crosstalk between CLL cells and their microenvironment and miRNAs may take part in this process.

Enhanced⁹⁹Tc retention in glass waste form using Tc(IV)-incorporated Fe minerals

OpenAIRE

Um, W; Luksic, SA; Wang, G; Saslow, S; Kim, DS; Schweiger, MJ; Soderquist, CZ; Bowden, ME; Lukens, WW; Kruger, AA

2017-01-01

© 2017 Elsevier B.V. Technetium ( 99 Tc) immobilization by doping into iron oxide mineral phases may alleviate the problems with Tc volatility during vitrification of nuclear waste. Because reduced Tc, Tc(IV), substitutes for Fe(III) in the crystal structure by a process of Tc reduction from Tc(VII) to Tc(IV) followed by co-precipitation of Fe oxide minerals, two Tc-incorporated Fe minerals (Tc-goethite and Tc-magnetite/maghemite) were prepared and tested for Tc retention in glass melt sample...

Comparison of fatigue crack initiation behavior in different microstructures of TC21 titanium alloy

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Tan Changsheng

2018-01-01

Full Text Available Cyclic heterogeneous deformation, slip characteristics and crack nucleation with different microstructures, such as bimodal microstructure (BM and fine lamellar microstructure (FLM in TC21 alloy (Ti-6Al-2Sn-2Zr-3Mo-1Cr-2Nb-0.1Si, were systematically investigated and analyzed during high cycle fatigue at room temperature. The results demonstrated that the FLM microstructure possesses higher high-cycle fatigue strength than those of the BM one. For BM, the heterogeneous plastic deformation existed within the different large primary α phase, such as equiaxed primary α and primary α lath. The cracks at interfaces and slip bands easily coalesce with each other to form large cracks in BM. However, the α laths with similar morphology and size (nanosize distributed uniformly in FLM and could relatively deform homogeneously in micro-region, which delayed the initiation of the fatigue crack. Based on the electron-backscattered diffraction (EBSD analysis, it found that the strain was nonuniformly distributed in BM, however, it is relatively homogeneous in FLM. Moreover, lots of straight cracks are parallel and along single intrusions within the β grain which delays the coalescence of cracks.

Preparation and biological characteristics of 99mTc-diol a renal agent

International Nuclear Information System (INIS)

Castanheira, I.; Paulo, A.; Neves, M.; Patricio, L.; Sawas-Dimopoulou, C.

1993-01-01

The present work concerns the production of 1,2-dihydroxypropyl-1-phosphonic acid (diol) by acid hydrolysis of (-cis) 1,2-epoxypropylphosphonic acid (phosphomycin), and its formation as a kit easily labeled with [ 99m Tc]pertechnetate. Biodistribution studies and whole-body autoradiographies in mice show that 99m Tc-diol has a specific affinity for the kidneys: it is rapidly cleared from the blood and excreted in urine. Part of the injected activity remains in the kidney cortex sufficiently long to permit kidney imaging. In comparison with other agents which also localize in the kidney cortex, such as 99m Tc-DMSA and 99m Tc-glucoheptonate ( 99m Tc-GHA), the main differences are the following: the peak of renal activity is reached early in the 5 min post-injection period for 99m Tc-diol, only at about 10 min post-injection for 99m Tc-GHA and after 3 h post-injection for 99m Tc-DMSA. The uptake of 99m Tc-diol by other organs, especially by bones, is much smaller than in the case of 99m Tc-DMSA. Unlike 99m Tc-DMSA, the biodistribution of 99m Tc-diol is not significantly influenced by acid-base imbalance. Moreover, the retention effect of hyperuricemia on 99m Tc-diol blood clearance and kidney excretion could be the result of a competition mechanism between this radiopharmaceutical and uric acid for a common transport system. The above biological characteristics suggest that 99m Tc-diol is a kidney radiopharmaceutical with an ability for functional and imaging studies. (author)

Comparing consideration of the biological behaviour of [sup(99m)Tc(DMPE)2Cl2]+ and [sup(99m)Tc(DMPE)3]+ in the rat

International Nuclear Information System (INIS)

Syhre, R.; Seifert, S.; Muenze, R.; Jander, R.; Kretschmar, M.

1984-01-01

The myotropic [sup(99m)Tc(DMPE) 3 ] + -complex was prepared by alakaline reduction of pertechnetate in an excess of DMPE and under absence of air with a radiochemical purity of > 95% and compared with the [sup(99m)TcCl 2 (DMPE) 2 ] + -complex concerning the tissue distribution and biokinetics. The tissue distribution corresponds nearly to the Tc(III)-complex with the exception of rather increased activity of the lungs. Tc(I)-DMPE is more lipophilic and stronger bound to human serum albumin than the Tc(III)-DMPE-complex. The biological half-lifes of the distribution phase of Tc(I)-DMPE are longer than the corresponding half-lifes determined for Tc(III)-DMPE. Target/nontarget ratios similar to 201 Tl are nearly achieved for Tc(III)-DMPE in the first 20 minutes after injection. The Tc(I)-DMPE-complex does not reach comparable heart/liver ratios within the first two hours after injection, the necessary heart/blood ratios only after 20-30 minutes. Both compounds are not stable in vivo. (orig.) [de

A simple and rapid technique for recovery of 99mTc from low specific activity (n,γ)99Mo based on solid-liquid extraction and column chromatography methodologies

International Nuclear Information System (INIS)

Chattopadhyay, Sankha; Das, Sujata Saha; Barua, Luna

2010-01-01

A simple and inexpensive method has been developed for the separation of 99m Tc from 99 Mo produced from the neutron activation of 98 Mo by 98 Mo(n,γ) 99 Mo nuclear reaction. The recovery of 99m Tc was performed by solid-liquid extraction based on alumina column chromatography. The overall radiochemical yield for the complete separation of 99m Tc was 85-97% (n=5). The separated Na[ 99m Tc]TcO 4 was of high radionuclidic, radiochemical and chemical purities. The method can be adopted for routine processing and use of 99m Tc in radiopharmacy operations.

Microbial reduction of 99Tc (as TcO4-) in anaerobic alkaline conditions

International Nuclear Information System (INIS)

Khizhnyak, T.; Simonoff, M.; Sergeant, C.; Simonoff, G.; Medvedeva-Lyalikova, N.N.

2003-01-01

The ability of bacteria to reduce pertechnetate in alkaline conditions was investigated using halophilic bacteria isolated from soda-lakes environments. Anaerobic halophilic bacteria were able to reduce as much as 0.25 mM pertechnetate, whereas no reduction took place without bacteria or in the presence of heat-killed bacteria. The results obtained showed reduction of Tc(VII)O 4 - to the Tc(V) and Tc(IV) at pH 10 in the carbonate-bicarbonate medium. About 57% of the total technetium was determined to be Tc(IV), 1-3% as a Tc(V) and 17-20% as a Tc(VII) after 1-3 days of incubation with bacteria. The microbial reduction of Tc(VII) in alkaline conditions has been suggested as a potential mechanism for the removal of Tc from contaminated environments or waste streams. (author)

Superconductivity in the W-Tc and W2C-Tc systems

International Nuclear Information System (INIS)

Giorgi, A.L.

1985-01-01

A series of compositions in the W-Tc, W 2 C-Re and W 2 C-Tc systems were prepared and examined for superconductivity. The crystal structure, lattice parameters and superconducting transition temperatures of the W 2 C-Tc are reported for the first time. Similar measurements were made on the W-Tc and W 2 C-Re systems and the results compared with previous published results for these systems. 7 refs., 2 figs., 2 tabs

The role of Tc-99m polyclonal human immunoglobulin G scintigraphy in Graves' ophthalmopathy

International Nuclear Information System (INIS)

Ortapamuk, H.; Hosal, B.; Naldoken, S.

2002-01-01

The aim of this study was to clarify whether Tc-99m HIG (Polyclonal Human Immunoglobulin G) can image and determine the severity of orbital involvement in patients with Graves' ophthalmopathy. Twenty-six patients between 19 and 56 years old with Graves' ophthalmopathy were examined. All patients received approximately 370 MBq Tc-99m HIG by intravenous (i.v.) injection. Planar and SPECT examination were performed 4 hours after the injection. Visual and semiquantitative evaluations were performed for both orbits by two independent observers. Clinically active ophthalmopathy patients had noticeably increased orbital accumulation of Tc-99m HIG. In patients with inactive disease, and 14 of 19 had no uptake, whereas 5 patients had orbital radioactivity accumulation. The duration of Graves' ophthalmopathy did not correlate with the presence of active ophthalmopathy and Tc-99m HIG grade. There was no correlation between clinical classification and clinical activity (r=278). There was a good correlation between clinical activity and the radioactivity grade with r=0.666 (p=0.01). The clinical classification closely correlated with Tc-99m HIG grade (r=0.423, p=0.05) Tc-99m HIG scan can clearly identified clinically active patients, and subclinical inflammation can be shown by this scintigraphic evaluation. The current preliminary results suggested that Tc-99m HIG SPECT might be useful for the assessment of disease activity in Graves' ophthalmopathy. (author)

TcCYPR04, a Cacao Papain-Like Cysteine-Protease Detected in Senescent and Necrotic Tissues Interacts with a Cystatin TcCYS4.

Science.gov (United States)

Cardoso, Thyago Hermylly Santana; Freitas, Ana Camila Oliveira; Andrade, Bruno Silva; Sousa, Aurizangela Oliveira de; Santiago, André da Silva; Koop, Daniela Martins; Gramacho, Karina Peres; Alvim, Fátima Cerqueira; Micheli, Fabienne; Pirovani, Carlos Priminho

2015-01-01

The interaction amongst papain-like cysteine-proteases (PLCP) and their substrates and inhibitors, such as cystatins, can be perceived as part of the molecular battlefield in plant-pathogen interaction. In cacao, four cystatins were identified and characterized by our group. We identified 448 proteases in cacao genome, whereof 134 were cysteine-proteases. We expressed in Escherichia coli a PLCP from cacao, named TcCYSPR04. Immunoblottings with anti-TcCYSPR04 exhibited protein increases during leaf development. Additional isoforms of TcCYSPR04 appeared in senescent leaves and cacao tissues infected by Moniliophthora perniciosa during the transition from the biotrophic to the saprophytic phase. TcCYSPR04 was induced in the apoplastic fluid of Catongo and TSH1188 cacao genotypes, susceptible and resistant to M. perniciosa, respectively, but greater intensity and additional isoforms were observed in TSH1188. The fungal protein MpNEP induced PLCP isoform expression in tobacco leaves, according to the cross reaction with anti-TcCYSPR04. Several protein isoforms were detected at 72 hours after treatment with MpNEP. We captured an active PLCP from cacao tissues, using a recombinant cacao cystatin immobilized in CNBr-Sepharose. Mass spectrometry showed that this protein corresponds to TcCYSPR04. A homology modeling was obtained for both proteins. In order to become active, TcCYSPR04 needs to lose its inhibitory domain. Molecular docking showed the physical-chemical complementarities of the interaction between the cacao enzyme and its inhibitor. We propose that TcCYSPR04 and its interactions with cacao cystatins are involved in the senescence and necrosis events related to witches' broom symptoms. This molecular interaction may be the target for future interventions to control witches' broom disease.

On the interaction of granite with Tc(IV) and Tc(VII) in aqueous solution

International Nuclear Information System (INIS)

Eriksen, T.E.; Cui, Daquing

1991-10-01

The behaviour of technetium in granite-groundwater systems under reducing conditions was investigated. The anion TcO 4 - was reduced to Tc(IV) and simultaneously precipitated as TcO 2 xnH 2 O on the granite surfaces. The electron sources are assumed to be iron oxides and/or iron containing minerals in the granite. The technetium concentration in ground water under repository conditions may be predicted assuming TcO 2 xnH 2 O as the solid phase and TcO(OH) 2 0 and TcO 4 - as the predominant aqueous complexes using a formation constant for TcO(OH) 2 0 of log K = -8.16 and a standard reduction potential E 0 for the reaction TcO 4 - + 3e - + 4H + = TcO 2 xnH 2 O of 0.738 V. The surface related distribution ratio K a for TcO(OH) 2 0 between Stripa granite and ground water is approximately 1 cm based on geometrical surface area. (au)

Methodology for the determination of environmental 129I and 99Tc

International Nuclear Information System (INIS)

Anderson, T.J.

1978-01-01

The Savannah River Laboratory is using existing techniques and developing new methodology to determine the environmental impact of the Savannah River Plant with regard to 129 I and 99 Tc. 129 I is determined by neutron activation after the method of Brauer. Activation products are quantified by γ-ray spectroscopy [Ge(Li)] following chemical isolation. 125 I is used as a yield tracer. 129 I amounts as low as 3.8 fCi can be determined with 30-minute counting times. An isotope dilution method for 99 Tc based on a three-stage surface ionization mass spectrometer is being developed. Its chemical isolation scheme ends with the Tc loaded on a single ion-exchange bead for enhanced mass-spectrometric sensitivity. 97 Tc will be used as a yield tracer. A lower limit of 0.2 fCi is sought. A modified method using liquid scintillation counting has determined 99 Tc in some aqueous samples. These methods have confirmed that 129 I and 99 Tc can be highly mobile in the aqueous environment, establishing the need for monitoring

Tuning the work function of VO_2(1 0 0) surface by Ag adsorption and incorporation: Insights from first-principles calculations

International Nuclear Information System (INIS)

Chen, Lanli; Wang, Xiaofang; Shi, Siqi; Cui, Yuanyuan; Luo, Hongjie; Gao, Yanfeng

2016-01-01

Graphical abstract: - Highlights: • After adsorption, there is a charge transfer from Ag to VO_2(1 0 0) surface, which thus increases the electron concentration in VO_2 thin film. • Ag adsorption on VO_2(1 0 0) surface process is an exothermic chemical process, and the adsorption system is stable. • The work function can be tuned by Ag adsorption on and incorporation into the VO_2(1 0 0) surface, which in turn regulates the phase transition temperature of VO_2. - Abstract: VO_2 is an attractive material for application to thermochromic optoelectronic devices such as smart windows, and Ag/VO_2 double-layered structure can effectively decrease the phase transition temperature (T_c) of VO_2 thin film, which is very important for practical application of VO_2. Previous works has shown that the decrease in phase transition temperature (T_c) seems to be relevant with the work function of VO_2 in Ag/VO_2 double-layered thin film, although the underlying mechanism of tuning its T_c by Ag incorporation and adsorption on the VO_2(1 0 0) surface has been rarely investigated. Our first-principles calculations reveal that the adsorption of Ag atoms on the VO_2(1 0 0) surface rather than incorporation of Ag exhibits a lower work function, which is ascribed to an integrated effect of charge transfer from Ag to VO_2(1 0 0) surface and enhanced surface dipole moment. The results suggest that the decrease in work function of VO_2 with Ag adsorption favors the reduction in T_c. The current findings are helpful to understand the fundamental mechanism for yielding high-efficiency VO_2-based optoelectronic devices.

Pharmaceutical grade sodium (99mTc) pertechnetate from 99Mo/99mTc-TCM-Autosolex generator

International Nuclear Information System (INIS)

Chattopadhyay, Sankha; Barua, Luna; Das, Sujata Saha

2014-01-01

Technetium-99m (T 1/2 = 6.02h; 140.51 keV (89%)) is the most useful radioisotope in diagnostic nuclear medicine. More than 80% of all diagnostic procedures done worldwide in nuclear medicine centre are performed with 99m Tc. Worldwide crisis of fission 99 Mo based generator in recent past had put the nuclear medicine fraternity in very harsh situation. In order to have an indigenous solution of this problem, we tried to develop a computer controlled semi automated 99 Mo/ 99m Tc generator using MEK solvent extraction technique, which utilizes abundantly available 99 Mo produced by (n,γ) reaction in BARC reactors. The aim of this work is to provide a more reliable, computer controlled module (TCM- AUTOSOLEX) for the recovery of pharmaceutical grade 99m Tc from low specific activity 99 Mo based on solvent extraction methodology

Initial direct comparison of 99mTc-TOC and 99mTc-TATE in identifying sites of disease in patients with proven GEP NETs.

Science.gov (United States)

Cwikla, Jaroslaw B; Mikolajczak, Renata; Pawlak, Dariusz; Buscombe, John R; Nasierowska-Guttmejer, Anna; Bator, Andrzej; Maecke, Helmut R; Walecki, Jerzy

2008-07-01

The imaging of neuroendocrine tumors has become one of the most significant areas in nuclear oncology. In an attempt to provide high-quality imaging and possible sensitivity at a reduced cost, time, and radiation dose, several (99m)Tc agents have been proposed. The aim of this initial study was to compare the tumor uptake and biodistribution of 2 new 6-hydrazinopyridine-3-carboxylic acid (HYNIC)-derivatized Tyr(3)-octreotide analogs, (99m)Tc-[HYNIC,Tyr(3)]octreotide ((99m)Tc-TOC) and (99m)Tc-[HYNIC,Tyr(3),Thr(8)]octreotide ((99m)Tc-TATE), in patients with somatostatin receptor-expressing tumors. Each of 12 patients with proven gastrointestinal pancreatic neuroendocrine tumors received a mean activity of 520 MBq of (99m)Tc-TOC and (99m)Tc-TATE. Scintigraphy with both tracers was performed 3-4 h after their injection using standard whole-body and SPECT imaging. The images were reviewed subjectively by 2 readers, who reported tumor uptake lesion by lesion. Both radiotracers demonstrated concordance between the results in 7 patients (58%). In total, 110 sites of disease were identified with (99m)Tc-TOC, compared with 115 with (99m)Tc-TATE. There was 1 case in which (99m)Tc-TOC identified sites of disease not seen on (99m)Tc-TATE imaging but 4 cases in which some sites of disease were seen with (99m)Tc-TATE and not (99m)Tc-TOC. In this initial study, both tracers seem to show similar sites of tumor, with (99m)Tc-TATE having a slight edge in the total number of lesions seen, especially in lymph node metastases.

Dosage of the Abcg1-U2af1 region modifies locomotor and cognitive deficits observed in the Tc1 mouse model of Down syndrome.

Directory of Open Access Journals (Sweden)

Damien Marechal

Full Text Available Down syndrome (DS results from one extra copy of human chromosome 21 and leads to several alterations including intellectual disabilities and locomotor defects. The transchromosomic Tc1 mouse model carrying an extra freely-segregating copy of human chromosome 21 was developed to better characterize the relation between genotype and phenotype in DS. The Tc1 mouse exhibits several locomotor and cognitive deficits related to DS. In this report we analyzed the contribution of the genetic dosage of 13 conserved mouse genes located between Abcg1 and U2af1, in the telomeric part of Hsa21. We used the Ms2Yah model carrying a deletion of the corresponding interval in the mouse genome to rescue gene dosage in the Tc1/Ms2Yah compound mice to determine how the different behavioral phenotypes are affected. We detected subtle changes with the Tc1/Ms2Yah mice performing better than the Tc1 individuals in the reversal paradigm of the Morris water maze. We also found that Tc1/Ms2Yah compound mutants performed better in the rotarod than the Tc1 mice. This data support the impact of genes from the Abcg1-U2af1 region as modifiers of Tc1-dependent memory and locomotor phenotypes. Our results emphasize the complex interactions between triplicated genes inducing DS features.

Bone turnover markers are correlated with total skeletal uptake of 99mTc-methylene diphosphonate (99mTc-MDP)

International Nuclear Information System (INIS)

Lenora, Janaka; Norrgren, Kristina; Thorsson, Ola; Wollmer, Per; Obrant, Karl J; Ivaska, Kaisa K

2009-01-01

Skeletal uptake of 99m Tc labelled methylene diphosphonate ( 99m Tc-MDP) is used for producing images of pathological bone uptake due to its incorporation to the sites of active bone turnover. This study was done to validate bone turnover markers using total skeletal uptake (TSU) of 99m Tc-MDP. 22 postmenopausal women (52–80 years) volunteered to participate. Scintigraphy was performed by injecting 520 MBq of 99m Tc-MDP and taking whole body images after 3 minutes, and 5 hours. TSU was calculated from these two images by taking into account the urinary loss and soft tissue uptake. Bone turnover markers used were bone specific alkaline phosphatase (S-Bone ALP), three different assays for serum osteocalcin (OC), tartrate resistant acid phosphatase 5b (S-TRACP5b), serum C-terminal cross-linked telopeptides of type I collagen (S-CTX-I) and three assays for urinary osteocalcin (U-OC). The median TSU of 99m Tc-MDP was 23% of the administered activity. All bone turnover markers were significantly correlated with TSU with r-values from 0.52 (p = 0.013) to 0.90 (p < 0.001). The two resorption markers had numerically higher correlations (S-TRACP5b r = 0.90, S-CTX-I r = 0.80) than the formation markers (S-Total OC r = 0.72, S-Bone ALP r = 0.66), but the difference was not statistically significant. TSU did not correlate with age, weight, body mass index or bone mineral density. In conclusion, bone turnover markers are strongly correlated with total skeletal uptake of 99m Tc-MDP. There were no significant differences in correlations for bone formation and resorption markers. This should be due to the coupling between formation and resorption

Comparison of facet joint activity on 99mTc-MDP SPECT/CT with facet joint signal change on MRI with fat suppression.

Science.gov (United States)

Lehman, Vance T; Murphy, Robert C; Schenck, Louis A; Carter, Rickey E; Johnson, Geoffrey B; Kotsenas, Amy L; Morris, Jonathan M; Nathan, Mark A; Wald, John T; Maus, Timothy P

2016-01-01

We compared signal change on magnetic resonance imaging (MRI) with fat suppression and bone scan activity of lumbar facet joints to determine if these two imaging findings are correlated. We retrospectively identified all patients who underwent imaging of the lumbar spine for pain evaluation using both technetium-99m methylene disphosphonate single-photon emission computed tomography/computed tomography (99mTc-MDP SPECT/CT) and MRI with at least one fat-suppressed T2- or T1-weighted sequence with gadolinium enhancement within a 180-day interval, at our institution between 1 January 2008 and 19 February 2013. Facet joint activity on 99mTc-MDP SPECT/CT and peri-facet signal change on MRI were rated as normal or increased. Agreement between the two examination types were determined with the κ and prevalence-adjusted bias-adjusted κ (PABAK) statistics. This study included 60 patients (28 male, 47%), with a mean age of 49±19.7 years (range, 12-93 years). The κ value indicated no agreement between 99mTc-MDP SPECT/CT and MRI (κ=-0.026; 95% confidence interval: -0.051, 0.000). The PABAK values were fair to high at each spinal level, which suggests that relatively low disease prevalence lowered the κ values. Together, the κ and PABAK values indicate that there is some degree of intermodality agreement, but that it is not consistent. Overall, facet joint signal change on fat-suppressed MRI did not always correlate with increased 99mTc-MDP SPECT/CT activity. MRI and 99mTc-MDP SPECT/CT for facet joint evaluation should not be considered interchangeable examinations in clinical practice or research.

Efficient preparation of {sup 99m}Tc(III) '4+1' mixed-ligand complexes for peptide labeling with high specific activity

Energy Technology Data Exchange (ETDEWEB)

Kunstler, Jens-Uwe [Biotectid GmbH, Deutscher Platz 5c, 04103 Leipzig (Germany); Seidel, Gesine [Institute of Radiopharmacy, Forschungszentrum Dresden-Rossendorf, P.O. Box 510 119, 01314 Dresden (Germany); Pietzsch, Hans-Jurgen, E-mail: h.j.pietzsch@fzd.d [Institute of Radiopharmacy, Forschungszentrum Dresden-Rossendorf, P.O. Box 510 119, 01314 Dresden (Germany)

2010-09-15

An improved labeling procedure for peptides attached to organometallic {sup 99m}Tc(III) '4+1' mixed-ligand complexes in which the radiometal is coordinated by a tripodal tetradentate chelator 2,2',2''-nitrilotriethanethiol (NS{sub 3}) and a monodentate isocyanide ligand is presented. The labeling procedure was evaluated by the synthesis of [{sup 99m}Tc(NS{sub 3})(L2-RGD)]. The containing radiopharmaceutically interesting RGD-peptide cyclo[Arg-Gly-Asp-D-Tyr-Lys] was modified with 4-isocyanobutanoic acid (L2) as linker conjugated to N{sup 6}-Lys to get the monodentate ligand L2-RGD. The structural identity of the {sup 99m}Tc-conjugate was confirmed by comparison to a Re reference compound. The Tc- and Re-conjugates had matching retention times under identical HPLC conditions. The {sup 99m}Tc-labeling was performed in a novel one-step procedure using the eluate of a {sup 99}Mo/{sup 99m}Tc generator, NS{sub 3}, the isocyanide modified peptide, SnCl{sub 2}, Na{sub 2}EDTA, mannitol and ascorbic acid in the reaction mixture. Using optimized reagents it is possible to label 50 nmol peptide with {sup 99m}Tc within 60 min at room temperature with a radiochemical yield higher than 95% and a specific activity of {approx}20 GBq/{mu}mol.

Reference Ranges in [(99m)Tc]Mercaptoacetyltriglycerine Renography

DEFF Research Database (Denmark)

Rewers, Kate I; Hvidsten, Svend; Gerke, Oke

2015-01-01

PURPOSE: The purpose of the study was to define reference ranges for quantitative parameters in [(99m)Tc]mercaptoacetyltriglycerine ([(99m)Tc]MAG3) renography to assist interpretation in a semi-automated (Xeleris, GE) compared to a manual (Picker, Odyssey) software package. PROCEDURES: Forty......-eight subjects approved for renal donation were evaluated with [(99m)Tc]MAG3 renography using both the Xeleris and the Picker software. RESULTS: Reference ranges for the two software were comparable regarding the relative function of the two kidneys (the split function, SF) and the residual activities (RA......). The time to peak whole-kidney activities (T max whole-kidney) was more dependent on the type of software. Using Bland-Altman limits, we found good and acceptable agreement between the two methods. CONCLUSIONS: We found good correlation between renography results using the Xeleris and Picker software...

Biokinetics and dosimetry in patients of 99mTc-EDDA/HYNIC-Tyr3-octreotide prepared from lyophilized kits

International Nuclear Information System (INIS)

Gonzalez-Vazquez, Armando; Ferro-Flores, Guillermina; Arteaga de Murphy, Consuelo; Gutierrez-Garcia, Zohar

2006-01-01

99m Tc-EDDA/HYNIC-Tyr 3 -octreotide ( 99m Tc-HYNIC-TOC) has shown high in vitro and in vivo stability, rapid background clearance and rapid detection of somatostatin receptor-positive tumors. The aim of this study was to establish a biokinetic model for 99m Tc-HYNIC-TOC prepared from lyophilized kits, and to evaluate its dosimetry as a tumor imaging agent in patients with histologically confirmed neuroendocrine tumors. Whole-body images from eight patients were acquired at 5, 60, 90, 180 min and 24 h after 99m Tc-HYNIC-TOC administration obtained from instant freeze-dried kit formulations with radiochemical purities >95%. Regions of interest (ROIs) were drawn around source organs on each time frame. The same set of ROIs was used for all eight scans and the count per minute (cpm) of each ROI was converted to activity using the conjugate view counting method. The image sequence was used to extrapolate 99m Tc-HYNIC-TOC time-activity curves in each organ, to adjust a biokinetic model using the SAAM software, and to calculate the total number of disintegrations (N) that occurred in the source regions. N data were the input for the OLINDA/EXM code to calculate internal radiation dose estimates. Images showed an average tumor/blood (heart) ratio of 4.3±0.7 in receptor-positive tumors at 1 h. The mean radiation absorbed dose calculated for a study using 740 MBq was 24, 21.5, 5.5 and 1.0 mSv for spleen, kidneys, liver and bone marrow respectively and the effective dose was 4.4 mSv

Biokinetics and dosimetry in patients of 99mTc-EDDA/HYNIC-Tyr3-octreotide prepared from lyophilized kits.

Science.gov (United States)

González-Vázquez, Armando; Ferro-Flores, Guillermina; Arteaga de Murphy, Consuelo; Gutiérrez-García, Zohar

2006-07-01

99mTc-EDDA/HYNIC-Tyr3-octreotide (99mTc-HYNIC-TOC) has shown high in vitro and in vivo stability, rapid background clearance and rapid detection of somatostatin receptor-positive tumors. The aim of this study was to establish a biokinetic model for 99mTc-HYNIC-TOC prepared from lyophilized kits, and to evaluate its dosimetry as a tumor imaging agent in patients with histologically confirmed neuroendocrine tumors. Whole-body images from eight patients were acquired at 5, 60, 90, 180 min and 24 h after 99mTc-HYNIC-TOC administration obtained from instant freeze-dried kit formulations with radiochemical purities >95%. Regions of interest (ROIs) were drawn around source organs on each time frame. The same set of ROIs was used for all eight scans and the count per minute (cpm) of each ROI was converted to activity using the conjugate view counting method. The image sequence was used to extrapolate 99mTc-HYNIC-TOC time-activity curves in each organ, to adjust a biokinetic model using the SAAM software, and to calculate the total number of disintegrations (N) that occurred in the source regions. N data were the input for the OLINDA/EXM code to calculate internal radiation dose estimates. Images showed an average tumor/blood (heart) ratio of 4.3+/-0.7 in receptor-positive tumors at 1 h. The mean radiation absorbed dose calculated for a study using 740 MBq was 24, 21.5, 5.5 and 1.0 mSv for spleen, kidneys, liver and bone marrow respectively and the effective dose was 4.4 mSv.

The Yersinia pseudotuberculosis and Yersinia pestis toxin complex is active against cultured mammalian cells.

Science.gov (United States)

Hares, Michelle C; Hinchliffe, Stewart J; Strong, Philippa C R; Eleftherianos, Ioannis; Dowling, Andrea J; ffrench-Constant, Richard H; Waterfield, Nick

2008-11-01

The toxin complex (Tc) genes were first identified in the insect pathogen Photorhabdus luminescens and encode approximately 1 MDa protein complexes which are toxic to insect pests. Subsequent genome sequencing projects have revealed the presence of tc orthologues in a range of bacterial pathogens known to be associated with insects. Interestingly, members of the mammalian-pathogenic yersiniae have also been shown to encode Tc orthologues. Studies in Yersinia enterocolitica have shown that divergent tc loci either encode insect-active toxins or play a role in colonization of the gut in gastroenteritis models of rats. So far little is known about the activity of the Tc proteins in the other mammalian-pathogenic yersiniae. Here we present work to suggest that Tc proteins in Yersinia pseudotuberculosis and Yersinia pestis are not insecticidal toxins but have evolved for mammalian pathogenicity. We show that Tc is secreted by Y. pseudotuberculosis strain IP32953 during growth in media at 28 degrees C and 37 degrees C. We also demonstrate that oral toxicity of strain IP32953 to Manduca sexta larvae is not due to Tc expression and that lysates of Escherichia coli BL21 expressing the Yersinia Tc proteins are not toxic to Sf9 insect cells but are toxic to cultured mammalian cell lines. Cell lysates of E. coli BL21 expressing the Y. pseudotuberculosis Tc proteins caused actin ruffles, vacuoles and multi-nucleation in cultured human gut cells (Caco-2); similar morphology was observed after application of a lysate of E. coli BL21 expressing the Y. pestis Tc proteins to mouse fibroblast NIH3T3 cells, but not Caco-2 cells. Finally, transient expression of the individual Tc proteins in Caco-2 and NIH3T3 cell lines reproduced the actin and nuclear rearrangement observed with the topical applications. Together these results add weight to the growing hypothesis that the Tc proteins in Y. pseudotuberculosis and Y. pestis have been adapted for mammalian pathogenicity. We further

Accumulation and release of 99Tc by a macrophyte of the Yenisei River (Elodea canadensis) in laboratory experiments

International Nuclear Information System (INIS)

Bolsunovsky, A.; Bondareva, L.

2008-01-01

The study addresses 99 Tc accumulation and release by Elodea canadensis, one of the abundant species of submerged plants in the Yenisei River. 99 Tc in water samples of the 'Elodea - Yenisei River water' model system and in the biomass fractions was measured using a liquid scintillation analyzer. Experiments on accumulation of 99 Tc by Elodea showed that 99 Tc activity concentration can reach 120±6 Bq/g dry wt, with the concentration factor for 99 Tc 2700±500 l/kg dry wt. In experiments on 99 Tc release, over 504 hours about 82% of the total 99 Tc activity was released into the water from the plant; most of 99 Tc was released within the first 192 hours. The data obtained using sequential chemical fractionation of biomass confirmed the experimental data on 99 Tc release, which suggested that most of the biomass-bound 99 Tc was adsorbed on the surface of Elodea. 99 Tc tightly bound to biomass (fractions of organics and mineral residue) constituted just 17% of the total 99 Tc activity. (author)

Preoperative localization of parathyroid carcinoma using Tc-99m MIBI.

Science.gov (United States)

Kitapçi, M T; Tastekin, G; Turgut, M; Caner, B; Kars, A; Barista, I; Bekdik, C

1993-03-01

A patient with parathyroid cancer is presented who underwent Tc-99m MIBI scintigraphy. The Tc-99m MIBI image demonstrated increased accumulation of activity at the lower pole of the left thyroid lobe which was later confirmed as a parathyroid cancer. Uptake by parathyroid cancer must be kept in mind as a cause of increased Tc-99m MIBI accumulation when a disease is in question in the thyroid or parathyroid gland.

Evaluation of renal function using 99mTc-MAG3

International Nuclear Information System (INIS)

Takayama, Teruhiko; Aburano, Tamio; Shuke, Noriyuki

1993-01-01

The utility of 99m Tc-mercaptoacetyltriglycine (MAG3) was studied clinically. In the renography obtained with 99m Tc-MAG3, the abdominal aorta and the common iliac arteries were clearly visualized in the vascular phase. Due to less background activity and high target to background ratio, the quality of 99m Tc-MAG3 image was superior to that of 123 I-OIH or 99m Tc-DTPA image. The parameters on the renogram including T max , T 2/3 , and T 1/2 were compared. The correlation of T max and T 2/3 or T 1/2 were not significant between 99m Tc-MAG3 and 123 I-OIH. Another parameter of C 20 /C max , where C 20 and C max are renal activities at 20 min after injection and at T max respectively, showed an excellent correlation between 99m Tc-MAG3 and 123 I-OIH. Using C 20 /C max , pattern of renogram can be characterized numerically. Concerning the relation between C 20 /C max and renogram pattern, standard renogram pattern showed the C 20 /C max value of less than 0.4, while hypofunctioning pattern showed more than 0.5. The correlation coefficient between the renal uptake of 99m Tc-MAG3 and 123 I-OIH was 0.880 with a correlation plot: 'Y=1.16X-0.043', where X and Y represent renal uptake of 99m Tc-MAG3 and 123 I-OIH, respectively. It can be concluded that 99m Tc-MAG3 is a useful renal imaging agent as an alternative to 123 I-OIH, in order to evaluate the proximal tubular function and calculate ERPF. (author)

Expression of an endoglucanase from Tribolium castaneum (TcEG1) in Saccharomyces cerevisiae.

Science.gov (United States)

Shirley, Derek; Oppert, Cris; Reynolds, Todd B; Miracle, Bethany; Oppert, Brenda; Klingeman, William E; Jurat-Fuentes, Juan Luis

2014-10-01

Insects are a largely unexploited resource in prospecting for novel cellulolytic enzymes to improve the production of ethanol fuel from lignocellulosic biomass. The cost of lignocellulosic ethanol production is expected to decrease by the combination of cellulose degradation (saccharification) and fermentation of the resulting glucose to ethanol in a single process, catalyzed by the yeast Saccharomyces cerevisiae transformed to express efficient cellulases. While S. cerevisiae is an established heterologous expression system, there are no available data on the functional expression of insect cellulolytic enzymes for this species. To address this knowledge gap, S. cerevisiae was transformed to express the full-length cDNA encoding an endoglucanase from the red flour beetle, Tribolium castaneum (TcEG1), and evaluated the activity of the transgenic product (rTcEG1). Expression of the TcEG1 cDNA in S. cerevisiae was under control of the strong glyceraldehyde-3 phosphate dehydrogenase promoter. Cultured transformed yeast secreted rTcEG1 protein as a functional β-1,4-endoglucanase, which allowed transformants to survive on selective media containing cellulose as the only available carbon source. Evaluation of substrate specificity for secreted rTcEG1 demonstrated endoglucanase activity, although some activity was also detected against complex cellulose substrates. Potentially relevant to uses in biofuel production rTcEG1 activity increased with pH conditions, with the highest activity detected at pH 12. Our results demonstrate the potential for functional production of an insect cellulase in S. cerevisiae and confirm the stability of rTcEG1 activity in strong alkaline environments. © 2013 Institute of Zoology, Chinese Academy of Sciences.

Diversification of 99Mo/99mTc separation: non–fission reactor production of 99Mo as a strategy for enhancing 99mTc availability.

Science.gov (United States)

Pillai, Maroor R A; Dash, Ashutosh; Knapp, Furn F Russ

2015-01-01

This paper discusses the benefits of obtaining (99m)Tc from non-fission reactor-produced low-specific-activity (99)Mo. This scenario is based on establishing a diversified chain of facilities for the distribution of (99m)Tc separated from reactor-produced (99)Mo by (n,γ) activation of natural or enriched Mo. Such facilities have expected lower investments than required for the proposed chain of cyclotrons for the production of (99m)Tc. Facilities can receive and process reactor-irradiated Mo targets then used for extraction of (99m)Tc over a period of 2 wk, with 3 extractions on the same day. Estimates suggest that a center receiving 1.85 TBq (50 Ci) of (99)Mo once every 4 d can provide 1.48-3.33 TBq (40-90 Ci) of (99m)Tc daily. This model can use research reactors operating in the United States to supply current (99)Mo needs by applying natural (nat)Mo targets. (99)Mo production capacity can be enhanced by using (98)Mo-enriched targets. The proposed model reduces the loss of (99)Mo by decay and avoids proliferation as well as waste management issues associated with fission-produced (99)Mo.

Tl-201 and Tc-99m-DTPA neuro-SPECT in cerebral radiation necrosis

International Nuclear Information System (INIS)

Cleto, E.M. Jr.; Holmes, R.A.; Gumerlock, M.K.; Cabeen, M.; Logan, K.W.; Hoffman, T.J.

1992-01-01

The results in 3 cases of radiation necrosis demonstrate that by using both radionuclides Tl-201 and Tc-99m-DTPA, one can provide a semi-quantitative method to differentiate recurrent tumor from radiation necrosis. Focally increased cerebral Tl-201 activity in irradiated brain tumor patients is not specific for tumor recurrence, but when used in combination with DTPA, one is able to estimate the amount of Tl-201 activity resulting from increased blood-brain barrier permeability. If the average Tl-201 index is less than the average Tc-99m-DTPA index it suggests that the increased Tl-201 activity results primarily from blood-brain barrier breakdown. Tc-99m-DTPA SPECT, in addition to Tl-201 SPECT, or serial Tl-201 SPECT imaging may increase the accuracy of brain scintigraphy in differentiating radiation necrosis from tumor recurrence. To verify these preliminary findings, we are in the process of analyzing additional SPECT data on 9 more patients with malignant brain tumors. Using a slightly different method of quantifying Tl- 201/Tc-99m-DTPA ratios (computing the ratio of intralesional Tl-201 or Tc-99m-DTPA activity compared to adjacent scalp activity), patients with tumor recurrence have higher Tl-201/Tc-99m-DTPA ratios compared to those with radiation necrosis (verbal communication with Dr. Mary K. Gumerlock). (orig.) [de

Evaluation of renal function using [sup 99m]Tc-MAG3; Comparison with [sup 123]I-OIH and [sup 99m]Tc-DTPA

Energy Technology Data Exchange (ETDEWEB)

Takayama, Teruhiko; Aburano, Tamio; Shuke, Noriyuki (Kanazawa Univ. (Japan). School of Medicine) (and others)

1993-07-01

The utility of [sup 99m]Tc-mercaptoacetyltriglycine (MAG3) was studied clinically. In the renography obtained with [sup 99m]Tc-MAG3, the abdominal aorta and the common iliac arteries were clearly visualized in the vascular phase. Due to less background activity and high target to background ratio, the quality of [sup 99m]Tc-MAG3 image was superior to that of [sup 123]I-OIH or [sup 99m]Tc-DTPA image. The parameters on the renogram including T[sub max], T[sub 2/3], and T[sub 1/2] were compared. The correlation of T[sub max] and T[sub 2/3] or T[sub 1/2] were not significant between [sup 99m]Tc-MAG3 and [sup 123]I-OIH. Another parameter of C[sub 20]/C[sub max], where C[sub 20] and C[sub max] are renal activities at 20 min after injection and at T[sub max] respectively, showed an excellent correlation between [sup 99m]Tc-MAG3 and [sup 123]I-OIH. Using C[sub 20]/C[sub max], pattern of renogram can be characterized numerically. Concerning the relation between C[sub 20]/C[sub max] and renogram pattern, standard renogram pattern showed the C[sub 20]/C[sub max] value of less than 0.4, while hypofunctioning pattern showed more than 0.5. The correlation coefficient between the renal uptake of [sup 99m]Tc-MAG3 and [sup 123]I-OIH was 0.880 with a correlation plot: 'Y=1.16X-0.043', where X and Y represent renal uptake of [sup 99m]Tc-MAG3 and [sup 123]I-OIH, respectively. It can be concluded that [sup 99m]Tc-MAG3 is a useful renal imaging agent as an alternative to [sup 123]I-OIH, in order to evaluate the proximal tubular function and calculate ERPF. (author).

Comparative measurement of sup(99m)Tc-thyroid-uptake (TcTU) using two different methods of data analysis

International Nuclear Information System (INIS)

Hotze, L.A.; Schmitz, R.

1982-01-01

A new program for automatic measurement of TcTU was developed and compared with a standard interactive method of data analysis. The new program fullfils the requirements for correct calculation of TcTU. The advantages are: reduced working load for the technician and a diminished frequency of erroneous results by improving automatisation of data handling and procedure of activity measurement as well as detailed informative dialogue with the computer without any need for special knowledge of data processing. (orig.) [de

LincRNA-p21 Impacts Prognosis in Resected Non-Small Cell Lung Cancer Patients through Angiogenesis Regulation.

Science.gov (United States)

Castellano, Joan J; Navarro, Alfons; Viñolas, Nuria; Marrades, Ramon M; Moises, Jorge; Cordeiro, Anna; Saco, Adela; Muñoz, Carmen; Fuster, Dolors; Molins, Laureano; Ramirez, Josep; Monzo, Mariano

2016-12-01

Long intergenic noncoding RNA-p21 (lincRNA-p21) is a long noncoding RNA transcriptionally activated by tumor protein p53 (TP53) and hypoxia inducible factor 1 alpha subunit (HIF1A). It is involved in the regulation of TP53-dependent apoptosis and the Warburg effect. We have investigated the role of lincRNA-p21 in NSCLC. LincRNA-p21 expression was assessed in tumor and normal tissue from 128 patients with NSCLC and correlated with time to relapse and cancer-specific survival (CSS). H23, H1299, and HCC-44 cell lines were cultured in hypoxic conditions after silencing of lincRNA-p21. The TaqMan human angiogenesis array was used to explore angiogenesis-related gene expression. Levels of the protein vascular endothelial growth factor A were measured by enzyme-linked immunosorbent assay in the cell supernatants. Angiogenic capability was measured by human umbilical vein endothelial cell tube formation assay. Microvascular density in tumor samples was analyzed by immunohistochemistry. LincRNA-p21 was down-regulated in tumor tissue, but no association was observed with TP53 mutational status. High lincRNA-p21 levels were associated with poor CSS in all patients (p = 0.032). When patients were classified according to histological subtypes, the impact of lincRNA-p21 was confined to patients with adenocarcinoma in both time to relapse (p = 0.006) and CSS (p < 0.001). To explain the poor outcome of patients with high lincRNA-p21 expression, we studied the role of lincRNA-p21 in angiogenesis in vitro and observed a global downregulation in the expression of angiogenesis-related genes when lincRNA-p21 was inhibited. Moreover, supernatants from lincRNA-p21-inhibited cells were significantly less angiogenic and had lower levels of secreted vascular endothelial growth factor A than controls did. Finally, tumor samples with high lincRNA-p21 levels had higher microvascular density. Our findings suggest that lincRNA-p21 affects outcome in patients with NSCLC adenocarcinoma through

Up-regulation of Kir2.1 by ER stress facilitates cell death of brain capillary endothelial cells

International Nuclear Information System (INIS)

Kito, Hiroaki; Yamazaki, Daiju; Ohya, Susumu; Yamamura, Hisao; Asai, Kiyofumi; Imaizumi, Yuji

2011-01-01

Highlights: → We found that application of endoplasmic reticulum (ER) stress with tunicamycin to brain capillary endothelial cells (BCECs) induced cell death. → The ER stress facilitated the expression of inward rectifier K + channel (K ir 2.1) and induced sustained membrane hyperpolarization. → The membrane hyperpolarization induced sustained Ca 2+ entry through voltage-independent nonspecific cation channels and consequently facilitated cell death. → The K ir 2.1 up-regulation by ER stress is, at least in part, responsible for cell death of BCECs under pathological conditions. -- Abstract: Brain capillary endothelial cells (BCECs) form blood brain barrier (BBB) to maintain brain homeostasis. Cell turnover of BCECs by the balance of cell proliferation and cell death is critical for maintaining the integrity of BBB. Here we found that stimuli with tunicamycin, endoplasmic reticulum (ER) stress inducer, up-regulated inward rectifier K + channel (K ir 2.1) and facilitated cell death in t-BBEC117, a cell line derived from bovine BCECs. The activation of K ir channels contributed to the establishment of deeply negative resting membrane potential in t-BBEC117. The deep resting membrane potential increased the resting intracellular Ca 2+ concentration due to Ca 2+ influx through non-selective cation channels and thereby partly but significantly regulated cell death in t-BBEC117. The present results suggest that the up-regulation of K ir 2.1 is, at least in part, responsible for cell death/cell turnover of BCECs induced by a variety of cellular stresses, particularly ER stress, under pathological conditions.

An intrapatient comparison of 99mTc-EDDA/HYNIC-TOC with 111In-DTPA-octreotide for diagnosis of somatostatin receptor-expressing tumors.

Science.gov (United States)

Gabriel, Michael; Decristoforo, Clemens; Donnemiller, Eveline; Ulmer, Hanno; Watfah Rychlinski, Christine; Mather, Stephen J; Moncayo, Roy

2003-05-01

The aim of this study was to compare the imaging abilities of the recently developed somatostatin analog, (99m)Tc-hydrazinonicotinyl-Tyr(3)-octreotide ((99m)Tc-HYNIC-TOC [(99m)Tc-TOC]), with (111)In-diethylenediaminepentaacetic acid-D-Phe(1)-octreotide ((111)In-OCT [Octreoscan]) in patients undergoing routine somatostatin receptor (SSTR) scintigraphy. Forty-one patients (20 men, 21 women; age range, 29-75 y; mean age, 56.7 y) with either histologically proven or biologically and clinically suspected endocrine tumors were enrolled in the study. Four groups were distinguished: (a) patients being evaluated for the detection and localization of neuroendocrine tumors (n = 6), (b) tumor staging (n = 19), (c) patients being investigated to determine the SSTR status of tumor lesions (n = 11), and (d) patient follow-up studies (n = 5). Each patient received a mean activity of 150 MBq (111)In-OCT and 350-400 MBq (99m)Tc-TOC. Scintigraphy with (99m)Tc-TOC was performed 4 h after injection and scintigraphy with (111)In-OCT was performed 4 and 24 h after injection. SPECT studies of areas of interest were performed 4 h after injection for both tracers as well as at 24 h after injection for (111)In-OCT. The time interval between the studies using each tracer ranged from 2 to 22 d (mean interval, 9.3 d). (111)In-OCT and (99m)Tc-TOC showed an equivalent scan result in 32 patients (78%), 9 cases showed discrepancies (22%), false-negative results with (111)In-OCT were seen in 6 cases (14.6%), whereas (99m)Tc-TOC was false-positive in 2 cases (4.9%). (111)In-OCT was true-negative in both cases. The false-positive findings of the (99m)Tc-TOC studies were caused by nonspecific uptake in the bowel. In 1 case, (99m)Tc-TOC correctly identified a metastasis in the lumbar spine but both scan results were false-positive because of an inflammatory process. In 21 patients with SSTR-expressing tumors, the semiquantitative region-of-interest analysis showed that (99m)Tc-TOC achieved higher tumor

Osmotic and activity coefficients of aqueous NaTcO4 and NaReO4 solutions at 250C

International Nuclear Information System (INIS)

Boyd, G.E.

1978-01-01

Isopiestic vapor-pressure comparison experiments were performed with aqueous binary sodium perchlorate, pertechnetate, and perrhenate solutions to concentrations of approximately 8.5 m. Osmotic coefficients for these solutions and mean molal ionic activity coefficients for NaTcO 4 and NaReO 4 were derived from the isotonic molalities. Pitzer's treatment was applied to describe the concentration dependence of the osmotic coefficients of NaClO 4 , NaTcO 4 , and NaReO 4 , and the implications of the parameters derived from a least-squares fit are discussed in terms of solvent structure and interionic forces. 4 tables, 1 figure

Organ distribution of sup(99m)Tc-Sn tetracycline antibiotics in rats

International Nuclear Information System (INIS)

Kalincak, M.; Machan, V.; Barna, K.

1976-01-01

The organ distribution of [sup(99m)Tc-Sn]tetracycline hydrochloride, [sup(99m)Tc-Sn]oxytetracycline hydrochloride and [sup(99m)Tc-Sn]rolitetracycline nitrate was studied in rats. It was shown that these preparations have a very similar organ distribution and are predominantly deposited in the kidneys. The maximum renal radioactivity level was found 2 to 4 hours after intravenous administration of the preparation, this, for [sup(99m)Tc-Sn]tetracycline hydrochloride 18.60%; for [sup(99m)Tc-Sn]oxytetracycline hydrochloride 17.09.=.; for [sup(99m)Tc-Sn]rolitetracycline nitrate 20.12%. The activity levels in the muscle, liver, heart, brain, lungs, stomach and spleen are minimal. (author)

Organ distribution of /sup 99m/Tc--Sn tetracycline antibiotics in rats

Energy Technology Data Exchange (ETDEWEB)

Kalincak, M; Machan, V; Barna, K [Univerzita P.J. Safarika, Kosice (Czechoslovakia). Lekarska Fakulta

1976-06-01

The organ distribution of (sup(99m)Tc-Sn)tetracycline hydrochloride, (sup(99m)Tc-Sn)oxytetracycline hydrochloride and (sup(99m)Tc-Sn)rolitetracycline nitrate was studied in rats. It was shown that these preparations have a very similar organ distribution and are predominantly deposited in the kidneys. The maximum renal radioactivity level was found 2 to 4 hours after intravenous administration of the preparation, this, for (sup(99m)Tc-Sn)tetracycline hydrochloride 18.60%; for (sup(99m)Tc-Sn)oxytetracycline hydrochloride 17.09.=.; for (sup(99m)Tc-Sn)rolitetracycline nitrate 20.12%. The activity levels in the muscle, liver, heart, brain, lungs, stomach and spleen are minimal.

Development of methodology for evaluation of {sup 99m}Tc and {sup 131}I incorporated activities during lactation; Desenvolvimento de metodologia para avaliacao da atividade de {sup 99m}Tc e {sup 131}I em lactantes

Energy Technology Data Exchange (ETDEWEB)

Santos, L. [Universidade Federal do Rio de Janeiro (IF/UFRJ), RJ (Brazil). Inst. de Fisica; Dantas, A.L.A.; Mesquita, S.A. [Universidade Federal do Rio de Janeiro (IF/UFRJ), RJ (Brazil). Inst. de Fisica; Oliveira, S.M.V., E-mail: adantas@ird.gov.br, E-mail: silvia@ird.gov.br [Universidade Federal do Rio de Janeiro (IF/UFRJ), RJ (Brazil). Inst. de Fisica; Instituto de Radioprotecao e Dosimetria (IRD/CNEN-RJ), Rio de Janeiro, RJ (Brazil). Div. de Dosimetria

2012-07-01

Internal contamination of babies may occur for milk ingestion or inhalation of mothers occupationally exposed to ionizing radiation with possible incorporation or mothers submitted to medical exposures during lactation. Radionuclide concentrations in the mother's milk may cause organ absorbed doses in the babies proportionally to the breast volumes. Milk analysis allow to determine activities ingested by the babies by determining the peak of mother's milk considering the decrease of the activity rate and the milk activities drunk at different time intervals. The work had the aim to develop simulators and methodology to evaluate {sup 99m}Tc and {sup 131}I in lactation, in the following steps: to prepare standard solution of contaminated milk separately with {sup 99m}Tc and {sup 131}I; to build four breast simulators (600 g and 800 g) and respective calibration for two geometries (breast and whole-body) in the Whole-Body Counter Unit in Instituto de Radioprotecao e Dosimetria. The results demonstrated the system efficiency to determine {sup 99m}Tc and {sup 131}I activities in breasts during the lactation period. The methodology for positioning in the 'breast geometry' seemed to be more efficient than the 'whole-body geometry' for different breast volumes. The experiment allows achieving better evaluation of internal dosimetry of mothers and their young children. (author)

Production and clinical evaluation of 99mTc-octreotide

International Nuclear Information System (INIS)

Fettich, J.; Kolenc-Peitl, P.

2004-01-01

Full text: Due to advantages of 99m-Tc labelled radiopharmaceuticals we examined the feasibility of producing 99m-Tcoctreotide in our laboratory and compare the results with 111-In-octreotide in the same patients. Keeping constant amount of components without exceeding amount of the peptide used, preparation of 99m-Tc-ethylendiaminediacetic- acidhydrazinonicotinamide-D-Phe1,Tyr3-octreotide (99m-Tc EDDA/HYNIC-TOC) was achieved. Radiochemical purity was tested using high-pressure liquid chromatography for 24 hours. In vitro stability testing of the product showed that radiochemical purity remained above 95% for 24 hours and the radiopharmaceutical was found suitable for human use. 5 - 10 μg of the peptide labelled with 550-650 MBq of 99m-Tc was prepared for each patient. 32 patients with clinically suspicious or confirmed carcinoid were investigated with 550 - 650 MBq 99m-Tcoctreotide prepared in our laboratory followed by 110 MBq 111-In-octreotide (Octreoscan, Mallinkrodt). Whole body scintigraphy and abdominal SPECT were performed 4 and 20 hrs after injection of respective radiopharmaceutical. In all patients both studies were acquired within 5 days. All patients gave informed consent for the study as required by Ethics committee. No abnormal tracer uptake was seen anywhere in the body in 12 patient with either of the radiopharmaceuticals. These were used to assess normal distribution of both radiopharmaceuticals. Normal accumulation was seen in case of both radiopharmaceuticals in the spleen, kidneys, liver and gallbladder. Biliary activity was seen in the gut in patients that were not well prepared for the study. There was significantly less activity seen in the kidneys in case of 99m-Tc-octreotide. This could be explained by higher hydrophilicity of the 99m-Tc-EDDA/HYNEC-TOC molecules as compared with 111-In-DTPA-octreotide. 20 patients with confirmed carcinoids showed abnormal uptake but without any difference in distribution of the two radiopharmaceuticals

Dose calibrator linearity test: {sup 99m}Tc versus {sup 18}F radioisotopes

Energy Technology Data Exchange (ETDEWEB)

Willegaignon, Jose; Coura-Filho, George Barberio; Garcez, Alexandre Teles, E-mail: willegaignon@hotmail.com [Instituto do Cancer do Estado de Sao Paulo Octavio Frias de Oliveira (ICESP), Sao Paulo, SP (Brazil); Sapienza, Marcelo Tatit; Buchpiguel, Carlos Alberto [Universidade de Sao Paulo (FM/USP), Sao Paulo, SP (Brazil). Fac. de Medicina; Alves, Carlos Eduardo Gonzalez Ribeiro; Cardona, Marissa Anabel Rivera; Gutterres, Ricardo Fraga [Comissao Nacional de Energia Nuclear (CNEN), Rio de Janeiro, RJ (Brazil)

2015-01-15

Objective: the present study was aimed at evaluating the viability of replacing {sup 18}F with {sup 99m}Tc in dose calibrator linearity testing. Materials and methods: the test was performed with sources of {sup 99m}Tc (62 GBq) and {sup 18}F (12 GBq) whose activities were measured up to values lower than 1 MBq. Ratios and deviations between experimental and theoretical {sup 99m}Tc and {sup 18}F sources activities were calculated and subsequently compared. Results: mean deviations between experimental and theoretical {sup 99m}Tc and {sup 18}F sources activities were 0.56 (± 1.79)% and 0.92 (± 1.19)%, respectively. The mean ratio between activities indicated by the device for the {sup 99m}Tc source as measured with the equipment precalibrated to measure {sup 99m}Tc and {sup 18}F was 3.42 (± 0.06), and for the {sup 18}F source this ratio was 3.39 (± 0.05), values considered constant over the measurement time. Conclusion: the results of the linearity test using {sup 99m}Tc were compatible with those obtained with the {sup 18}F source, indicating the viability of utilizing both radioisotopes in dose calibrator linearity testing. Such information in association with the high potential of radiation exposure and costs involved in {sup 18}F acquisition suggest {sup 99m}Tc as the element of choice to perform dose calibrator linearity tests in centers that use {sup 18}F, without any detriment to the procedure as well as to the quality of the nuclear medicine service. (author)

Tc-99m-hexakis(t-butylisonitrile)-technetium(I) (Tc-99m-TBI)

International Nuclear Information System (INIS)

Angelberger, P.; Dudczak, R.; Jones, A.G.; Lister-James, J.; Wagner-Loffler, M.; Buchheit, O.; Fally, F.

1986-01-01

The potassium analog (Tl-201)/sup +/ is widely used in nuclear cardiology but has inferior scintigraphic (80 keV photons), dosimetric and economic properties as compared to Tc-99m. Therefore considerable efforts have been made to develop a Tc-compound that would accumulate in the myocardium in relation to regional blood flow. This study was aimed at optimizing the preparation of Tc-TBI with n.c.a. Tc-99m, analyze and purify the product with HPLC, verify biodistribution in mice and undertake a clinical evaluation

Baseline Tc-99m DTPA renal scintigraphy as a predictor of outcome in children with urinary tract infection

Energy Technology Data Exchange (ETDEWEB)

Yun, J. G.; An, Y. S.; Lee, M. H.; Cho, C. W.; Yun, S. N.; Pai, G. S [Ajou University Medical Center, Suwon (Korea, Republic of)

2004-07-01

Tc-99m DTPA renal scintigraphy is useful in detecting urinary tract obstruction in patients with urinary tract infection (UTI). We evaluated the prognostic significance of baseline Tc-99m DTPA renal scintigraphy in children with UTI. Among children, who underwent both baseline/follow-up Tc-99m DMSA scintigraphies and baseline Tc-99m DTP A scintigraphy for evaluation of UTI, 32 patients with unilateral cortical defects on baseline Tc-99m DMSA scintigraphy were included in the study. The outcome of cortical defects was evaluated on follow-up Tc-99m DMSA scintigraphy by visual analysis. ROIs were drawn on the Tc-99m DPTA scintigraphy for calculation of ipsilateral to contralateral kidney ratio (ICR) at blood flow phase (< 60s, BFP) and cortical uptake phase (1-5 min, CUP). Median follow-up period of Tc-99m DMSA scintigraphy was 3.2 months (1.4 - 14 months). There were 24 patients with healing cortical defects and 8 with cortical scarring. Average ICRs of patients with healing defects were 1.11 {+-} 0.18 (0.44 - 1.57) at BFP and 0.97 {+-} 0.21 (0.31 - 1.28) at CUP, while those of patients with cortical scarring were 0.97 {+-} 0.47 (0.21 - 0.89) at BFP and 0.75 {+-} 0.49 (0.19 - 1.65) at CUP. ICR more than 0.9 was determined as a good prognostic indicator. The sensitivity, specificity, positive predictive value, and negative predictive value of ICR was 83.3%, 100%, 100% and 66.7% at BFP, and 79.0%, 62.5%, 86.4% and 50.0% at CUP. Ipsilateral to contralateral kidney ratio on baseline Tc-99m DPTA renal scintigraphy, especially at blood flow phase, is helpful in predicting outcome of children with UTI.

Baseline Tc-99m DTPA renal scintigraphy as a predictor of outcome in children with urinary tract infection

International Nuclear Information System (INIS)

Yun, J. G.; An, Y. S.; Lee, M. H.; Cho, C. W.; Yun, S. N.; Pai, G. S

2004-01-01

Tc-99m DTPA renal scintigraphy is useful in detecting urinary tract obstruction in patients with urinary tract infection (UTI). We evaluated the prognostic significance of baseline Tc-99m DTPA renal scintigraphy in children with UTI. Among children, who underwent both baseline/follow-up Tc-99m DMSA scintigraphies and baseline Tc-99m DTP A scintigraphy for evaluation of UTI, 32 patients with unilateral cortical defects on baseline Tc-99m DMSA scintigraphy were included in the study. The outcome of cortical defects was evaluated on follow-up Tc-99m DMSA scintigraphy by visual analysis. ROIs were drawn on the Tc-99m DPTA scintigraphy for calculation of ipsilateral to contralateral kidney ratio (ICR) at blood flow phase (< 60s, BFP) and cortical uptake phase (1-5 min, CUP). Median follow-up period of Tc-99m DMSA scintigraphy was 3.2 months (1.4 - 14 months). There were 24 patients with healing cortical defects and 8 with cortical scarring. Average ICRs of patients with healing defects were 1.11 ± 0.18 (0.44 - 1.57) at BFP and 0.97 ± 0.21 (0.31 - 1.28) at CUP, while those of patients with cortical scarring were 0.97 ± 0.47 (0.21 - 0.89) at BFP and 0.75 ± 0.49 (0.19 - 1.65) at CUP. ICR more than 0.9 was determined as a good prognostic indicator. The sensitivity, specificity, positive predictive value, and negative predictive value of ICR was 83.3%, 100%, 100% and 66.7% at BFP, and 79.0%, 62.5%, 86.4% and 50.0% at CUP. Ipsilateral to contralateral kidney ratio on baseline Tc-99m DPTA renal scintigraphy, especially at blood flow phase, is helpful in predicting outcome of children with UTI

FGF21 as an Endocrine Regulator in Lipid Metabolism: From Molecular Evolution to Physiology and Pathophysiology

Directory of Open Access Journals (Sweden)

Yusuke Murata

2011-01-01

Full Text Available The FGF family comprises twenty-two structurally related proteins with functions in development and metabolism. The Fgf21 gene was generated early in vertebrate evolution. FGF21 acts as an endocrine regulator in lipid metabolism. Hepatic Fgf21 expression is markedly induced in mice by fasting or a ketogenic diet. Experiments with Fgf21 transgenic mice and cultured cells indicate that FGF21 exerts pharmacological effects on glucose and lipid metabolism in hepatocytes and adipocytes via cell surface FGF receptors. However, experiments with Fgf21 knockout mice indicate that FGF21 inhibits lipolysis in adipocytes during fasting and attenuates torpor induced by a ketogenic diet but maybe not a physiological regulator for these hepatic functions. These findings suggest the pharmacological effects to be distinct from the physiological roles. Serum FGF21 levels are increased in patients with metabolic diseases having insulin resistance, indicating that FGF21 is a metabolic regulator and a biomarker for these diseases.

Clearance of sup(99m)Tc-diisopropyl-IDA in the steady state

Energy Technology Data Exchange (ETDEWEB)

Karimeddini, M K; Vogler, M A; Spencer, R P

1984-10-01

A 77-year-old man with a stent in lace for biliary drainage was examined. Intravenously administered sup(99m)Tc-diisopropyl-IDA showed little accumulation of activity in the abdomen while the stent was draining internally. Upon switching the stent to external drainage, it was possible to monitor the slow movement of the bile which contained radioactivity. Imaging over the liver and comparing activity changes with a sup(99a)Tc standard showed that the decrease in hepatic radioactivity was identical to that occurring in the sup(99m)Tc standard. The liver was thus in a ''steady state'' for excretion of the sup(99m)Tc hepatobiliary agent, for it was extracting as much radioactivity from the circulation as it was excreting.

Update of the BIPM.RI(II)-K1.Tc-99m comparison of activity measurements for the radionuclide {sup 99m}Tc to include new results for the LNE-LNHB and the NPL

Energy Technology Data Exchange (ETDEWEB)

Michotte, C.; Courte, S.; Ratel, G. [Bureau International des Poids et Mesures (BIPM), 92 - Sevres (France); Moune, M. [LNE-LNHB, Laboratoire national de metrologie et d' essais-Laboratoire National Henri Becquerel, Gif sur Yvette (France); Johansson, L.; Keightley, J. [National Physical Laboratory (NPL), Middlesex (United Kingdom)

2010-12-15

In 2007 and 2008 respectively, the Laboratoire national de metrologie et d'essais -Laboratoire national Henri Becquerel (LNE-LNHB), France and the National Physical Laboratory (NPL), UK, submitted ampoules with between 10 MBq and 130 MBq activity of {sup 99m}Tc to the International Reference System (SIR), to update their results in the BIPM.RI(II)-K1.Tc-99m comparison. Together with the four other national metrology institutes (NMI) that are participants, thirteen samples have been submitted since 1983. The key comparison reference value (KCRV) has been recalculated to include the latest primary results of the PTB and the LNE-LNB as this makes the evaluation more robust. The degrees of equivalence between each equivalent activity measured in the SIR are given in the form of a matrix for all six NMIs. A graphical presentation is also given. (authors)

Chemical aspects of labeling sucralfate with 99mTcO4

International Nuclear Information System (INIS)

Billinghurst, M.W.; Abrams, D.N.; Lawson, M.S.

1989-01-01

Two formulations of [ 99m Tc]sucralfate have been used to image gastric and duodenal ulcers and inflammatory bowel disease. One formulation is a complexation of [ 99m Tc]HSA with sucralfate. The second is prepared by directly labeling sucralfate with [ 99m Tc]pertechnetate in the presence of stannous ion. An in vitro study of the factors affecting the production and stability of these labeled sucralfate preparations was conducted. Both formulations were stable at the acidic pH likely encountered in the stomach. However, at pH greater than 6 the albumin-sucralfate complex began to dissociate while directly labeled sucralfate was stable to a pH of 9. Conversely it was shown that directly labeled sucralfate was more susceptible to loss of 99m Tc to other chelating species. Sucralfate complexed with [ 99m Tc]HSA was radiochemically stable up to a specific activity of 26 GBq (700 mCi) per gram while directly labeled sucralfate showed decreased 24-hr stability at specific activities greater than 837 mCi (31 GBq) per gram

Direct 99mTc labeling of monoclonal antibodies: radiolabeling and in vitro stability

International Nuclear Information System (INIS)

Garron, J.Y.; Moinereau, M.; Pasqualini, R.; Saccavini, J.C.

1991-01-01

Direct labeling involves 99m Tc binding to different donor groups on the protein, giving multiple binding sites of various affinities resulting in an in vivo instability. The stability has been considerably improved by activating the antibody using a controlled reduction reaction (using 2-aminoethanethiol). This reaction generates sulfhydryl groups, which are known to strongly bind 99m Tc. The direct 99m Tc antibody labeling method was explored using whole antibodies and fragments. Analytical methods were developed for routine evaluation of radiolabeling yield and in vitro stability. Stable direct antibody labeling with 99m Tc requires the generation of sulfhydryl groups, which show high affinity binding sites for 99m Tc. Such groups are obtained with 2-aminoethanethiol (AET), which induces the reduction of the intrachain or interchain disulfide bond, with no structural deterioration or any loss of immunobiological activity of the antibody. The development of fast, reliable analytical methods has made possible the qualitative and quantitative assessment of technetium species generated by the radiolabeling process. Labeling stability is determined by competition of the 99m Tc-antibody bond with three ligands, Chelex 100 (a metal chelate-type resin), free DTPA solution and 1% HSA solution. Very good 99m Tc-antibody stability is obtained with activated IgG (IgGa) and Fab' fragment, which makes these substances possible candidates for immunoscintigraphy use. (author)

Influence of the irradiation time on the activity of decay products during the cooling. Case: Mo-98 {yields} Mo-99 {yields} Tc-99m; Influencia del tiempo de irradiacion en la actividad de los productos de decaimiento durante el enfriamiento. Caso: Mo-98 {yields} Mo-99 {yields} Tc-99m

Energy Technology Data Exchange (ETDEWEB)

Reyes J, J.L.; Ruiz C, M.A.; Alanis M, J. [Instituto Nacional de Investigaciones Nucleares, A.P. 18-1027, 11801 Mexico D.F. (Mexico)

2002-07-01

In this work the behavior of the activity in the cooling time of Mo-99, Tc-99 and Tc-99m obtained by Neutron activation of natural Mo is described. The analytical development is based on the application of the Laplace transform for resolving the balance equations. (Author)

Problems in clinical practice of domestic supply of 99Mo/99mTc. Considerations on the domestic production of 99Mo/99mTc

International Nuclear Information System (INIS)

Yamabayashi, Hisamichi

2012-01-01

At present, a bulky import product, 99 Mo supplied in Japan is produced by a nuclear fission method which enables to produce a generator system with no need of commercially preparing 99m Tc-labeled radiopharmaceuticals due to its high specific activity. However its usage of enriched uranium target leads to avoiding the fission method from the option of domestic production. In order to secure the domestic supply of 99 Mo/ 99m Tc, the neutron activation method, aiming to meet about 20% of domestic demand, is under development along with the re-start program of JMTR. Development of various production methods using accelerators are also in progress. In those non-fission methods with reactors or accelerators, rapid and effective procedures for concentration and refinement of 99m Tc solution eluted from 99 Mo of low specific activity are the subjects to be considered for attaining the stable labeling performances. (author)

CBX7 regulates stem cell-like properties of gastric cancer cells via p16 and AKT-NF-κB-miR-21 pathways.

Science.gov (United States)

Ni, Su-Jie; Zhao, Li-Qin; Wang, Xiao-Feng; Wu, Zhen-Hua; Hua, Rui-Xi; Wan, Chun-Hua; Zhang, Jie-Yun; Zhang, Xiao-Wei; Huang, Ming-Zhu; Gan, Lu; Sun, Hua-Lin; Dimri, Goberdhan P; Guo, Wei-Jian

2018-02-08

Chromobox protein homolog 7 (CBX7), a member of the polycomb group (PcG) family of proteins, is involved in the regulation of cell proliferation and cancer progression. PcG family members, such as BMI, Mel-18, and EZH2, are integral constituents of the polycomb repressive complexes (PRCs) and have been known to regulate cancer stem cell (CSC) phenotype. However, the role of other PRCs' constituents such as CBX7 in the regulation of CSC phenotype remains largely elusive. This study was to investigate the role of CBX7 in regulating stem cell-like properties of gastric cancer and the underlying mechanisms. Firstly, the role of CBX7 in regulating stem cell-like properties of gastric cancer was investigated using sphere formation, Western blot, and xenograft tumor assays. Next, RNA interference and ectopic CBX7 expression were employed to determine the impact of CBX7 on the expression of CSC marker proteins and CSC characteristics. The expression of CBX7, its downstream targets, and stem cell markers were analyzed in gastric stem cell spheres, common cancer cells, and gastric cancer tissues. Finally, the pathways by which CBX7 regulates stem cell-like properties of gastric cancer were explored. We found that CBX7, a constituent of the polycomb repressive complex 1 (PRC1), plays an important role in maintaining stem cell-like characteristics of gastric cancer cells via the activation of AKT pathway and the downregulation of p16. Spearman rank correlation analysis showed positive correlations among the expression of CBX7 and phospho-AKT (pAKT), stem cell markers OCT-4, and CD133 in gastric cancer tissues. In addition, CBX7 was found to upregulate microRNA-21 (miR-21) via the activation of AKT-NF-κB pathway, and miR-21 contributes to CBX7-mediated CSC characteristics. CBX7 positively regulates stem cell-like characteristics of gastric cancer cells by inhibiting p16 and activating AKT-NF-κB-miR-21 pathway.

Quantitative evaluation of bile diversion surgery utilizing /sup 99m/Tc HIDA scintigraphy

International Nuclear Information System (INIS)

Wickremesinghe, P.C.; Dayrit, P.Q.; Manfredi, O.L.; Fazio, R.A.; Fagel, V.L.

1983-01-01

This is a report of 21 patients presenting with epigastric pain, bilious vomiting, upper gastrointestinal bleeding, iron-deficiency anemia, and weight loss, who had undergone Billroth II gastrectomy from 3 to 35 yr earlier. Eighteen of 21 patients were found to have significant enterogastric reflux indices varying from 60% to 95% demonstrated by /sup 99m/Tc HIDA scintigraphy. Thirteen patients had diversion antireflux surgery in the form of a Roux-en-Y procedure, and 1 patient had a Henley loop jejunal interposition. Postoperative /sup 99m/Tc HIDA scintigraphic studies showed the enterogastric reflux indices to have decreased significantly to a range of 2%-26% (p less than 0.00001). There was marked improvement of symptoms, including correction of anemia and weight gain in those patients who had been anemic or who had sustained earlier weight loss. The enterogastric reflux indices of 10 asymptomatic control patients after Billroth II gastrectomy ranged from 4% to 45%. /sup 99m/Tc HIDA scintigraphy is useful in evaluating patients before and after bile diversion surgery, and demonstrates the quantitative decrease in enterogastric reflux after such surgery

Evaluation of '9{sup 9}Mo presence in eluates of {sup 99}mTc used in nuclear medicine; Avaliacao da presenca de {sup 99}Mo em eluatos de {sup 99m}Tc utilizados em medicina nuclear

Energy Technology Data Exchange (ETDEWEB)

Ribeiro, Bianca da Silva

2010-07-01

Tc-99m is used for diagnostic imaging in nuclear medicine through SPECT technique. It is obtained by the elution of {sup 99}Mo/{sup 99m}Tc generators. During the elution process {sup 99}Mo can be extracted becoming a radionuclidic impurity. One of the quality parameters of the eluate is the radionuclidic purity, MBT (molybdenum break through), defined as the ratio between {sup 99}Mo and {sup 99m}Tc activities in the eluate. The North-American and European pharmacopoeias restrict the {sup 99}Mo content, respectively, in 0.015 e 0.1% and, according to the International Atomic Energy Agency (IAEA), the activity ratio at the moment of administration of the radiopharmaceutical to the patient, should not exceed 0.015%. In Brazil, the control of such parameter is not obliged in official regulations. Thus, the objective of this work is to evaluate the occurrence of {sup 99}Mo in {sup 99m}Tc eluates. It was initially optimized a methodology to determine the activity of {sup 99}Mo in eluate samples. Efficiency curves were obtained for a NaI (Tl) 8'' x 4'' scintillation detector installed at the In Vivo Monitoring Laboratory (LABMIV-IRD). The methodology has been validated through the measurement of a {sup 99}Mo standard liquid source calibrated at the National Metrology Laboratory for Ionizing Radiation (LNMRI-IRD). The samples analyzed in this work were gently supplied by 5 Nuclear Medicine Clinics located in the city of Rio de Janeiro. The activities of {sup 99}mTc and {sup 99}Mo in those samples have been measured respectively at the clinics and at the LABMIV. By applying a standardized methodology, the ration between the activities were calculated. The results show that 147 out of 174 samples presented {sup 99}Mo activities above the minimum detectable activity of the technique. On the other hand, only 2 out of 147 samples surpassed the MBT limit suggested by the IAEA and have been detected in samples eluted from generators of 750 mCi. In one of the

Inhibitory effect of trans-caryophyllene (TC) on leukocyte-endothelial attachment.

Science.gov (United States)

Zhang, Zhen; Yang, Chunfeng; Dai, Xinlun; Ao, Yu; Li, Yumei

2017-08-15

trans-Caryophyllene (TC) is a major component found in the essential oils of many spices and foods/medicinal plants. It is a natural sesquiterpene and has been the subject of numerous studies. However, the effects of TC on vascular inflammation remain unknown. In this study, we reported that TC treatment in human umbilical vein endothelial cells (HUVECs) prevented attachment of monocytic leukemia cell line THP-1 cells to endothelial cells. In addition, in vivo results indicate that TC inhibited macrophage infiltration to the aortic surface and reduced total serum levels of cholesterol and triglycerides. Importantly, administration of TC could inhibit the induction of vascular cell adhesion molecule-1 (VCAM-1) both in vitro and in vivo. Notably, our data indicate that the inhibitory effects of TC on the expression of VCAM-1 are mediated by the JAK2/STAT1/IRF-1 pathway. TC is a specific agonist of the type 2 cannabinoid receptor (CB2R). Importantly, we further verified that the inhibitory effects of TC on the expression of IRF-1 and VCAM-1 are dependent on activation of CB2R. Inhibition of CB2R by either specific inhibitors or RNA interference abolished the inhibitory effects of TC on the expression of IRF-1 and VCAM-1. Our results suggest that TC might have a capacity to suppress the development of atherosclerosis. Copyright © 2017 Elsevier Inc. All rights reserved.

Rapid radiochemical methods for preparation of sup(99m)Tc labelled compounds

International Nuclear Information System (INIS)

Narasimhan, D.V.S.; Banodkar, S.M.; Kothari, K.; Mani, R.S.

1981-01-01

Several inorganic and organic compounds incorporating sup( 99 m)Tc are being extensively used for imaging various body organs. The preparation of these sup( 99 m)Tc compounds with the necessary purity requirements is carried out by controlled reduction of sup( 99 m)Tc-pertechnetate using Sn(II) ions as the reducing agent followed by complexation with various active ingredients. The authors here present procedures developed at Radiopharmaceuticals Section of BARC for preparing sup( 99 m)Tc-diphosphonate, sup( 99 m)Tc-glucoheptonate, sup( 99 m)Tc-albumin microspheres and sup( 99 m)Tc-phytate with high radiochemical purity. The paper also describes procedures for the preparation of freeze-dried kits for single step preparation of these compounds. The paper also describes the authors' experience with various analytical procedures for the determination of radiochemical purity of these preparations. (author)

Preliminary studies of 99mTc-memantine derivatives for NMDA receptor imaging

International Nuclear Information System (INIS)

Zhou Xingqin; Zhang Jiankang; Yan Chenglong; Cao Guoxian; Zhang Rongjun; Cai Gangming; Jiang Mengjun; Wang Songpei

2012-01-01

Introduction: Novel technetium-labeled ligands, 99m Tc-NCAM and 99m Tc-NHAM were developed from the N-methyl-D-aspartate (NMDA) receptor agonist memantine as a lead compound by coupling with N 2 S 2 . This study evaluated the binding affinity and specificity of the ligands for the NMDA receptor. Methods: Ligand biodistribution and uptake specificity in the brain were investigated in mice. Binding affinity and specificity were determined by radioligand receptor binding assay. Three antagonists were used for competitive binding analysis. In addition, uptake of the complexes into SH-SY5Y nerve cells was evaluated. Results: The radiochemical purity of 99m Tc-labeled ligands was more than 95%. Analysis of brain regional uptake showed higher concentration in the frontal lobe and specific uptake in the hippocampus. 99m Tc-NCAM reached a higher target to nontarget ratio than 99m Tc-NHAM. The results indicated that 99m Tc-NCAM bound to a single site on the NMDA receptor with a K d of 701.21 nmol/l and a B max of 62.47 nmol/mg. Specific inhibitors of the NMDA receptor, ketamine and dizocilpine, but not the dopamine D 2 and 5HT 1A receptor partial agonist aripiprazole, inhibited specific binding of 99m Tc-NCAM to the NMDA receptor. Cell physiology experiments showed that NCAM can increase the viability of SH-SY5Y cells after glutamate-induced injury. Conclusions: The new radioligand 99m Tc-NCAM has good affinity for and specific binding to the NMDA receptor, and easily crosses the blood–brain barrier; suggesting that it might be a potentially useful tracer for NMDA receptor expression.

Comparison of 99mTc-HYNIC-TOC and HYNIC-TATE octreotide scintigraphy with FDG PET and 99mTc-MIBI in local recurrent or distant metastatic thyroid cancers.

Science.gov (United States)

Sager, Sait; Kabasakal, Levent; Halac, Metin; Maecke, Helmut; Uslu, Lebriz; Önsel, Çetin; Kanmaz, Bedii

2013-05-01

There have been various studies for early diagnosis of local recurrent or distant metastatic thyroid cancers. The aim of this study is to evaluate the clinical utility of 99mTc-HYNIC-TOC and 99mTc-HYNIC-TATE, octreotide derivatives, to detect recurrences or distant metastases in 131I-negative thyroglobulin positive thyroid cancer patients and to compare the lesions with FDG PET and 99mTc-MIBI studies in the same patient group. Twenty differentiated thyroid cancer patients, 7 male and 13 female, mean age 54.6 ± 15.3 (range 13-78 years), were included in this study. Eighteen patients had papillary thyroid cancer and 2 had follicular thyroid cancer. Fifteen patients received HYNIC-TOC and 5 patients received HYNIC-TATE as a radiopharmaceutical. All patients underwent whole-body scan 1 and 4 hours after injection of octreotide derivatives and SPECT imagings were performed from the suspicious sites. The lesions that were seen in 99mTc-HYNIC-TOC and 99mTc-HYNIC-TATE studies were compared with 99mTc-MIBI and FDG-PET studies. Among 99mTc-HYNIC-TOC and 99mTc-HYNIC-TATE scintigraphies, 15 patient studies were evaluated as true positive (75%) and 5 were false negative (25%). The total number of lesions in octreotide scintigraphy was 48 in 20 patients. Of 20 patients, 19 had FDG-PET study, 15 of them were evaluated as true positive (78.9%), and 4 them were evaluated as false negative (21.1%). Total number of lesions in FDG PET was 74. 99mTc-MIBI study was positive in 11 patients (55%) and negative in 9 patients (45%). Total number of lesions in 99mTc-MIBI was 25. Technetium-labeled somatostatin receptor scintigraphy analogues HYNIC-TOC and HYNIC-TATE are useful imaging alternatives in somatostatin receptor expressing thyroid cancer patients. Radiolabeling is easy and they are readily available for routine use.

Use of /sup 99m/Tc-DTPA for detection and localization of site of acute gastrointestinal bleeding

Energy Technology Data Exchange (ETDEWEB)

Abdel-Dayem, H.; Owuwanne, A.; Nawaz, K.; Kouris, K.; Higazy, E.; Mahajan, K.; Ericsson, S.; Awdeh, M.

1988-05-01

Intravenously injected /sup 99m/Tc-DTPA was evaluated in 64 patients for its efficiency in detecting and localizing sites of acute upper and lower gastrointestinal (G.I.) bleeding. These studies were correlated with endoscopic and surgical findings. There were 34 bleeders and 30 non bleeders giving a sensitivity of 90%, specificity of 82% and accuracy of 86%. Of these, 49 were upper G.I. studies (stomach 21 and duodenum 28) and 15 were lower G.I. studies (small intestine 8, large bowel 7). Of the 49 upper G.I. studies, 27 showed active bleeding while 22 showed no bleeding at the time of the study resulting in a sensitivity of 87.5%, specificity of 76% and accuracy of 82%. Of the 15 lower G.I. studies, 7 were bleeders while 8 were non bleeders. All the lower G.I. bleeding sites were accurately localized with the /sup 99m/Tc-DTPA. An incidental finding of these studies was the localization of /sup 99m/Tc-DTPA in the site of inflammatory and malignant lesions of the G.I. tract. Of the 64 studies, 18 inflammatory and malignant lesions were detected with the IV injected /sup 99m/Tc-DTPA; 10 were bleeders while 8 were non bleeders. Image subtraction of early from delayed images was helpful to differentiate bleeding from non bleeding cases in this last group of studies.

The use of 99mTc-DTPA for detection and localization of site of acute gastrointestinal bleeding

International Nuclear Information System (INIS)

Abdel-Dayem, H.; Owuwanne, A.; Nawaz, K.; Kouris, K.; Higazy, E.; Mahajan, K.; Ericsson, S.; Awdeh, M.; Kuwait Univ. Dept. of Surgery)

1988-01-01

Intravenously injected 99m Tc-DTPA was evaluated in 64 patients for its efficiency in detecting and localizing sites of acute upper and lower gastrointestinal (G.I.) bleeding. These studies were correlated with endoscopic and surgical findings. There were 34 bleeders and 30 non bleeders giving a sensitivity of 90%, specificity of 82% and accuracy of 86%. Of these, 49 were upper G.I. studies (stomach 21 and duodenum 28) and 15 were lower G.I. studies (small intestine 8, large bowel 7). Of the 49 upper G.I. studies, 27 showed active bleeding while 22 showed no bleeding at the time of the study resulting in a sensitivity of 87.5%, specificity of 76% and accuracy of 82%. Of the 15 lower G.I. studies, 7 were bleeders while 8 were non bleeders. All the lower G.I. bleeding sites were accurately localized with the 99m Tc-DTPA. An incidental finding of these studies was the localization of 99m Tc-DTPA in the site of inflammatory and malignant lesions of the G.I. tract. Of the 64 studies, 18 inflammatory and malignant lesions were detected with the IV injected 99m Tc-DTPA; 10 were bleeders while 8 were non bleeders. Image subtraction of early from delayed images was helpful to differentiate bleeding from non bleeding cases in this last group of studies. (orig.)

Determination of 99Mo contamination in 99mTc elute obtained from 99Mo/99mTc- generator

International Nuclear Information System (INIS)

Momennezhad, M.; Zakavi, S. R.; Sadeghi, R.

2010-01-01

99m Tc is a widely used radioisotope in nuclear medicine centers which is obtained by elution from Mo-99/Tc-99m generators. Usually the generators are either supplied by the Iran Atomic Energy Agency or by private companies from foreign countries. In this study we have measured 99 Mo contamination in 99m Tc elute from different generators in a period of one year. Materials and Methods: The radionuclide impurity of the 99m Tc elute were studied in two types of radionuclide generators (A: produced in Iran and B: Imported from other country). In-vitro measurements were performed using dose calibrator. Direct measurements were made, using a standard canister at the time of milking of the generators and also in Subsequent hours after milking. Results: The results showed a mean of 99 Mo impurity in generators A and B to be 0.00932±0.0043 and 0.0170±0.0127 respectively. Although the results showed that the 99 Mo contamination in 99 mTc elute was lesser than the maximum accepted activity limit of 0.015%, the difference in these two types may reflect different methods of productions of generator, as well as the quality control procedures. Conclusion: The mean of 99 Mo contamination in generators produced in Iran Atomic Energy Organization was lesser than generators imported from foreign origin.

Bioaccumulation and distribution of /sup 95m/Tc in an experimental freshwater pond

International Nuclear Information System (INIS)

Blaylock, B.G.; Frank, M.L.

1981-01-01

An acute release of /sup 95m/Tc was made to a small experimental freshwater pond to determine the behavior of technetium in a freshwater ecosystem. The objectives of the study were (1) to determine the distribution of /sup 95m/Tc in the components of the ecosystem and (2) to determine the concentration in freshwater biota. Prior to the release of /sup 95m/Tc, the pond was stocked with aquatic macrophytes, fish, and invertebrates. All components of the pond were sampled for a period of 37 d. Analyses of filtered and unfiltered water samples showed that /sup 95m/Tc did not sorb significantly to particulates suspended in the water but remained dissolved. Sediments accumulated /sup 95m/Tc slowly as the experiment progressed. In the biota, periphyton accumulated /sup 95m/Tc rapidly, reaching the highest concentration (3482 dpm/g dry wt) 4 h after the release and maintaining a relatively high concentration throughout the experiment. Fish and invertebrates accumulated /sup 95m/Tc gradually. Elimination studies and tissue analyses showed that a large percentage of the body burden was in the digestive system of all fish, suggesting that fish were accumulating /sup 95m/Tc through the food chain. Biological half-lives determined from elimination studies for carp (Cyprinus carpio), mosquitofish (Gambusia affinis), and snails (Helisoma sp.) were 2.5, 4.3, and 21.3 d, respectively. Calculated concentration factors for the same species were 11 for carp, 75 for mosquito fish, and 121 for snails. The estimated size of the biomass components in the ecosystem in descending order were: periphyton, macrophytes, invertebrates, fish, and algae. Based on biomass estimates and concentrations of the /sup 95m/Tc in the aquatic biota, approximately 1% of the /sup 95m/Tc accumulated in the biota

Tc: chemistry and radiopharmaceuticals: a prospectus

International Nuclear Information System (INIS)

Tulip, T.H.

1987-01-01

The recent explosion in technetium chemistry evident in this symposium promises to continue unabated. As in the past, radiopharmaceutical applications will lead to new Tc chemistry. In this lecture the author will discuss those areas which appear most fertile based on chemical and radiopharmaceutical criteria. Among these will be new organometallic Tc chemistry (e.g., Tc(CNR) 6 cations), Tc complexes as metabolic tracers (e.g., Tc-analogs to FDG), and peptide-based Tc chelators (e.g., Tc-metallothionein)

sup(99m)Tc-labeled monofluorophosphate as a skeletal imaging agent

International Nuclear Information System (INIS)

Ichikawa, Tsuneji; Ito, Yasuhiko; Muranaka, Akira; Yokobayashi, Tsuneo; Uchida, Masahiro

1976-01-01

The performance of sup(99m)Tc-monofluorophosphate was compared with those of sup(99m)Tc-pyrophosphate and sup(99m)Tc-diphosphonate in rabbits. Studies included chromatographic quality control, measurements of blood clearance, tissue distribution, urinary excretion, skeletal imaging, and measurements of the serum calcium. The labeling for sup(99m)Tc-monofluorophosphate was 98% on paper chromatography and 85% on thin layer chromatography. A large fraction of the activity of the three labeled agents was cleared very rapidly from the bloodstream: however, slow components of the curves were the highest for sup(99m)Tc-monofluorophosphate and lowest for sup(99m)Tc-diphosphonate. Three hours after injection 20% of the dose of sup(99m)Tc-monofluorophosphate was taken up by bone. The corresponding values of sup(99m)Tc-pyrophosphate and sup(99m)Tc-diphosphonate were 29.1% and 40.0% respectively. Ratio of concentration in bone to that in other major organs was highest with sup(99m)Tc-diphosphonate. Ratios were similar for both sup(99m)Tc-monofluorophosphate and sup(99m)Tc-pyrophosphate and much lower than those of sup(99m)Tc-diphosphonate. No significant differences were demonstrated in urinary excretion of the three labeled agents. Visual comparison of the scans obtained with three compounds confirmed the results of radioassay. All were excellent skeletal imaging agents, although sup(99m)Tc-diphosphonate appeared to be superior to the other two mainly because of a higher target to non-target ratio. With 50 mg of monofluorophosphate and 1 mg of stannous fluoride, no hypocalcemia was observed. (J.P.N.)

Biokinetics and dosimetry in patients of {sup 99m}Tc-EDDA/HYNIC-Tyr{sup 3}-octreotide prepared from lyophilized kits

Energy Technology Data Exchange (ETDEWEB)

Gonzalez-Vazquez, Armando [Departamento de Medicina Nuclear, Hospital Militar (Mexico); Facultad de Medicina, Universidad Autonoma del Estado de Mexico (Mexico); Ferro-Flores, Guillermina [Departamento de Materiales Radiactivos, Gerencia de Aplicaciones Nucleares en la Salud, Instituto Nacional de Investigaciones Nucleares, Km. 36.5 Carretera Mexico-Toluca, Ocoyoacac, Estado de Mexico, C.P. 52045 (Mexico)]. E-mail: gff@nuclear.inin.mx; Arteaga de Murphy, Consuelo [Departamento de Medicina Nuclear, Instituto Nacional de Ciencias Medicas y Nutricion Salvador Zubiran (Mexico); Gutierrez-Garcia, Zohar [Departamento de Medicina Nuclear, Hospital Militar (Mexico)

2006-07-15

{sup 99m}Tc-EDDA/HYNIC-Tyr{sup 3}-octreotide ({sup 99m}Tc-HYNIC-TOC) has shown high in vitro and in vivo stability, rapid background clearance and rapid detection of somatostatin receptor-positive tumors. The aim of this study was to establish a biokinetic model for {sup 99m}Tc-HYNIC-TOC prepared from lyophilized kits, and to evaluate its dosimetry as a tumor imaging agent in patients with histologically confirmed neuroendocrine tumors. Whole-body images from eight patients were acquired at 5, 60, 90, 180 min and 24 h after {sup 99m}Tc-HYNIC-TOC administration obtained from instant freeze-dried kit formulations with radiochemical purities >95%. Regions of interest (ROIs) were drawn around source organs on each time frame. The same set of ROIs was used for all eight scans and the count per minute (cpm) of each ROI was converted to activity using the conjugate view counting method. The image sequence was used to extrapolate {sup 99m}Tc-HYNIC-TOC time-activity curves in each organ, to adjust a biokinetic model using the SAAM software, and to calculate the total number of disintegrations (N) that occurred in the source regions. N data were the input for the OLINDA/EXM code to calculate internal radiation dose estimates. Images showed an average tumor/blood (heart) ratio of 4.3{+-}0.7 in receptor-positive tumors at 1 h. The mean radiation absorbed dose calculated for a study using 740 MBq was 24, 21.5, 5.5 and 1.0 mSv for spleen, kidneys, liver and bone marrow respectively and the effective dose was 4.4 mSv.

99mTc-Tetrofosmin scintimammography in suspected breast cancer patients: comparison with 99mTc-MIBI

International Nuclear Information System (INIS)

Kim, Seong Jang; Kim, In Ju; Kim, Yong Ki; Bae, Young Tae

2000-01-01

The aim of this study was to investigate the diagnostic role of 99m Tc-Tetrofosmin in detection of breast cancer and compared with that of 99m Tc-MIBI. Forty-eight patients with a clinically palpable mass or abnormal mammographic or ultrasonographic findings had 99m Tc-MIBI and 99m Tc-Tetrofosmin scintimammographies after intravenous injection of 925 MBq of radiopharmaceuticals. The scintimammographs were correlated with histopathologic findings. Thirty-three patients were diagnosed with breast cancer and 15 patients with benign breast diseases. The numbers of true positive, true negative, false positive, and false negative cases of 99m Tc-MIBI scintimammography were 29, 10, 5, and 4 respectively. The sensitivity, specificity, positive predictive value, and negative predictive value of 99m Tc-MIBI scintimammographies were 87.8%, 66.7%, 85.3%, and 71.4% respectively. The numbers of true positive, true negative, false positive, and false negative cases of 99m Tc-Tetrofosmin were 31, 10, 5, and 2 respectively. The sensitivity, specificity, positive predictive value, negative predictive value of 99m Tc-Tetrofosmin were 93.9%, 66.7%, 86.1%, and 73.3% respectively. One patient was false negative in both 99m Tc-Tetrofosmin scintimammographies and its size was 0.5cm. 99m Tc-Tetrofosmin and 99m Tc-MIBI were non-invasive and useful in detection of breast cancer and 99m Tc-Tetrofosmin was comparable to the 99m Tc-MIBI in detection of primary breast cancer.=20

Expanding the knowledge of the geographic distribution of Trypanosoma cruzi TcII and TcV/TcVI genotypes in the Brazilian Amazon.

Directory of Open Access Journals (Sweden)

Valdirene Dos Santos Lima

Full Text Available Trypanosoma cruzi infection is a complex sylvatic enzooty involving a wide range of animal species. Six discrete typing units (DTUs of T. cruzi, named TcI to TcVI, are currently recognized. One unanswered question concerning the epidemiology of T. cruzi is the distribution pattern of TcII and hybrid DTUs in nature, including their virtual absence in the Brazilian Amazon, the current endemic area of Chagas disease in Brazil. Herein, we characterized biological samples that were collected in previous epizootiological studies carried out in the Amazon Basin in Brazil. We performed T. cruzi genotyping using four polymorphic genes to identify T. cruzi DTUs: mini-exon, 1f8, histone 3 and gp72. This analysis was conducted in the following biological samples: (i two T. cruzi isolates obtained by culturing of stools from the triatomine species Rhodnius picttipes and (ii five serum samples from dogs in which trypomastigotes were observed during fresh blood examination. We report for the first time the presence of TcII and hybrid DTUs (TcV/TcVI in the Amazon region in mixed infections with TcI. Furthermore, sequencing of the constitutive gene, gp72, demonstrated diversity in TcII even within the same forest fragment. These data show that TcII is distributed in the five main Brazilian biomes and is likely more prevalent than currently described. It is very probable that there is no biological or ecological barrier to the transmission and establishment of any DTU in any biome in Brazil.

Imaging of rat cerebral ischemia-reperfusion injury using99mTc-labeled duramycin

International Nuclear Information System (INIS)

Zhang Yuqing; Stevenson, Gail D.; Barber, Christy; Furenlid, Lars R.; Barrett, Harrison H.; Woolfenden, James M.; Zhao Ming; Liu Zhonglin

2013-01-01

Objectives: Prompt identification of necrosis and apoptosis in the infarct core and penumbra region is critical in acute stroke for delineating the underlying ischemic/reperfusion molecular pathologic events and defining therapeutic alternatives. The objective of this study was to investigate the capability of 99m Tc-labeled duramycin in detecting ischemia-reperfusion injury in rat brain after middle cerebral artery (MCA) occlusion. Methods: Ischemic cerebral injury was induced in ten rats by vascular insertion of a nylon suture in the left MCA for 3 hr followed by 21–24 hr reperfusion. After i.v. injection of 99m Tc-duramycin (1.0-3.5 mCi), dynamic cerebral images were acquired for 1 hr in six rats using a small-animal SPECT imager. Four other rats were imaged at 2 hr post-injection. Ex vivo images were obtained by autoradiography after sacrifice. Histologic analyses were performed to assess cerebral infarction and apoptosis. Results: SPECT images showed that 99m Tc-duramycin uptake in the left cerebral hemisphere was significantly higher than that in the right at 1 and 2 hr post-injection. The level of radioactive uptake in the ischemic brain varied based on ischemic severity. The average ratio of left cerebral hot-spot uptake to right hemisphere radioactivity, as determined by computerized ROI analysis, was 4.92 ± 0.79. Fractional washout at 1 hr was 38.2 ± 4.5% of peak activity for left cerebral hot-spot areas and 80.9 ± 2.0% for remote control areas (P 99m Tc-duramycin SPECT imaging may be useful for detecting and quantifying ongoing apoptotic neuronal cell loss induced by ischemia-reperfusion injury.

Nanotechnology Standardization Activities – Support of U.S. Representation on ISO/TC 229 Nanotechnologies

Energy Technology Data Exchange (ETDEWEB)

Benko, Heather [American National Standards Inst. (ANSI), Washington, DC (United States)

2017-03-14

In carrying out its responsibilities on behalf of the United States, ANSI provides comprehensive, administrative support and expertise on international protocols and procedures to: (1) the U.S. Technical Advisory Group (TAG) to the International Organization for Standardization’s (ISO) Technical Committee (TC) 229 Nanotechnologies, and (2) the corresponding U.S. TAG Working Groups tasked with formulating U.S. positions on topics relevant to nanotechnology standardization. Additionally, secretariat and procedural support is provided for the ISO/TC 229 WG 3 on health, safety and environment, for which the United States was assigned leadership by the participating national body members of ISO/TC 229. As the official entity that serves as the U.S. representative to ISO, ANSI provides not only expert coordination of U.S. positions and representation at ISO but also strategic direction, advice and procedural expertise to facilitate navigation of international issues to promote U.S. positions for incorporation into the ISO/TC 229 program of work necessary to support U.S. objectives.

Determination of bone blood supply with /sup 99m/Tc red blood cells and /sup 113m/In transferrin in fractures of femoral neck: concise communication

Energy Technology Data Exchange (ETDEWEB)

Kempi, V.; Sandegard, J.

1982-05-01

The uptake of in vivo labeled /sup 99m/Tc RBCs and /sup 113/In transferrin was studied in femoral bone of 21 patients who had recent operations for fracture of the femoral neck. Femoral bone biopsies and blood samples were obtained during the operation. The activity values for bone biopsies, erythrocytes, and serum were determined, and the uptake ratios between bone and erythrocyte cpm/g and between bone and serum were calculated. Biopsy samples were taken from the femoral head in 21 cases and from the trochanteric region in 14. The activity ratios for the two tracers correlated well: r . 0.94 for femoral head biopsies (P less than 0.001) and r . 0.98 for samples from the trochanteric region (P less than 0.001). Thus, the procedures are interchangeable and either may be valuable in assessing bone blood supply. An additional patient, studied only with /sup 99m/Tc RBCs, had a subsequent operation for nonunion of a fracture. Samples of both cancellous and cortical bone were obtained from the removed head. The activity ratios for the two types of bone tissue differed significantly (P . 0.02).

Determination of bone blood supply with /sup 99m/Tc red blood cells and /sup 113m/In transferrin in fractures of femoral neck: concise communication

International Nuclear Information System (INIS)

Kempi, V.; Sandegard, J.

1982-01-01

The uptake of in vivo labeled /sup 99m/Tc RBCs and 113 In transferrin was studied in femoral bone of 21 patients who had recent operations for fracture of the femoral neck. Femoral bone biopsies and blood samples were obtained during the operation. The activity values for bone biopsies, erythrocytes, and serum were determined, and the uptake ratios between bone and erythrocyte cpm/g and between bone and serum were calculated. Biopsy samples were taken from the femoral head in 21 cases and from the trochanteric region in 14. The activity ratios for the two tracers correlated well: r . 0.94 for femoral head biopsies (P less than 0.001) and r . 0.98 for samples from the trochanteric region (P less than 0.001). Thus, the procedures are interchangeable and either may be valuable in assessing bone blood supply. An additional patient, studied only with /sup 99m/Tc RBCs, had a subsequent operation for nonunion of a fracture. Samples of both cancellous and cortical bone were obtained from the removed head. The activity ratios for the two types of bone tissue differed significantly

Quantitative scintigraphy analysis of the normal lacrimal drainage using 99mTc radioisotope

International Nuclear Information System (INIS)

Bittar, Marcos Daniel Ramos.

1994-01-01

The dynamics of the lacrimal drainage system was studied in 37 normal patients including 16 males and 21 females by means of a radioisotope 99m Tc (technetium as pertechnetate in a normal saline solution), a gamma camera and a computer. After instillation of 10 μl normal saline solution containing 99m Tc in the conjunctival sac a scintigram was taken at the beginning and at the end of 10 minutes measuring time and images were recorded every 5 seconds. Two areas were studied: conjunctival and lacrimal sac. 39 refs., 17 figs., 1 tab

Comparison of relative renal function measured with either 99m Tc-DTPA or 99m Tc-EC dynamic scintigraphies with that measured with 99m Tc-DMSA static scintigraphy

Energy Technology Data Exchange (ETDEWEB)

Domingues, F.C.; Fujikawa, G.Y.; Decker, H.; Alonso, G.; Pereira, J.C.; Duarte, P.S. [Centro de Diagnostico Fleury, Sao Paulo, SP (Brazil). Secao de Medicina Nuclear; Sao Paulo Univ. (USP), SP (Brazil). Escola de Saude Publica. Dept. de Epidemiologia]. E-mail: paulo.duarte@fleury.com.br

2006-07-15

Objective: The aim of this study was to compare the renal function measured with either {sup 99m}Tc-DTPA or {sup 99m}Tc-EC dynamic scintigraphies with that measured using {sup 99m}Tc-DMSA static scintigraphy. Methods: the values of relative renal function measured in 111 renal dynamic scintigraphies performed either with {sup 99m}Tc-DTPA (55 studies) or with {sup 99m}Tc-EC (56 studies) were compared with the relative function measured using {sup 99m}Tc-DMSA static scintigraphy performed within a 1-month period. The comparisons were performed using Wilcoxon signed rank test. The number of {sup 99m}Tc-DTPA and {sup 99m}Tc-EC studies that presented relative renal function different by more than 5% from that measured with {sup 99m}Tc-DMSA, using chi square test were also compared. Results: the relative renal function measured with {sup 99m}Tc-EC is not statistically different from that measured with {sup 99m}Tc-DMSA (p = 0.97). The relative renal function measured with {sup 99m}Tc-DTPA was statistically different from that measured using {sup 99m}Tc-DMSA, but with a borderline statistical significance (p = 0.05). The number of studies with relative renal function different by more than 5% from that measured with {sup 99m}Tc-DMSA is higher for the {sup 99m}Tc-DTPA scintigraphy (p 0.04) than for {sup 99m}Tc-EC. Conclusion: the relative renal function measured with {sup 99m}Tc-EC dynamic scintigraphy is comparable with that measured with {sup 99m}Tc-DMSA static scintigraphy, while the relative renal function measured with {sup 99m}Tc-DTPA dynamic scintigraphy presents a significant statistical difference from that measured with {sup 99m}Tc-DMSA static scintigraphy. (author)

Comparison of relative renal function measured with either 99m Tc-DTPA or 99m Tc-EC dynamic scintigraphies with that measured with 99m Tc-DMSA static scintigraphy

International Nuclear Information System (INIS)

Domingues, F.C.; Fujikawa, G.Y.; Decker, H.; Alonso, G.; Pereira, J.C.; Duarte, P.S.; Sao Paulo Univ.

2006-01-01

Objective: The aim of this study was to compare the renal function measured with either 99m Tc-DTPA or 99m Tc-EC dynamic scintigraphies with that measured using 99m Tc-DMSA static scintigraphy. Methods: the values of relative renal function measured in 111 renal dynamic scintigraphies performed either with 99m Tc-DTPA (55 studies) or with 99m Tc-EC (56 studies) were compared with the relative function measured using 99m Tc-DMSA static scintigraphy performed within a 1-month period. The comparisons were performed using Wilcoxon signed rank test. The number of 99m Tc-DTPA and 99m Tc-EC studies that presented relative renal function different by more than 5% from that measured with 99m Tc-DMSA, using chi square test were also compared. Results: the relative renal function measured with 99m Tc-EC is not statistically different from that measured with 99m Tc-DMSA (p = 0.97). The relative renal function measured with 99m Tc-DTPA was statistically different from that measured using 99m Tc-DMSA, but with a borderline statistical significance (p = 0.05). The number of studies with relative renal function different by more than 5% from that measured with 99m Tc-DMSA is higher for the 99m Tc-DTPA scintigraphy (p 0.04) than for 99m Tc-EC. Conclusion: the relative renal function measured with 99m Tc-EC dynamic scintigraphy is comparable with that measured with 99m Tc-DMSA static scintigraphy, while the relative renal function measured with 99m Tc-DTPA dynamic scintigraphy presents a significant statistical difference from that measured with 99m Tc-DMSA static scintigraphy. (author)

Using Tc-Re chemical analogy to synthesize and identify new 99mTc complexes

International Nuclear Information System (INIS)

Gambino, D.; Kremer, C.; Cartesio, S.; Leon, A.; Kremer, E.

1989-01-01

The strong chemical resemblance between Tc and Re is applied to design and evaluate experiments with 99m Tc complexes. A combination of spectrophotometric and electrophoretic techniques allows to propose the formula [TcO 2 (amine) 2 ] + for compounds prepared by reduction of 99m TcO 4 - with Zn (solid phase) in presence of several (bidentate) amines. (author) 10 refs.; 2 figs.; 4 tabs

Synthesis, radiochromatography and biodistribution of sup(99m)Tc-dimethylphosphinoethane (DMPE) complexes

International Nuclear Information System (INIS)

Angelberger, P.; Wagner-Loeffler, M.; Hruby, E.; Dudczak, R.

1985-01-01

The title complex were prepared from no-carrier-added sup(99m)Tc-TcOsub(4)sup(-) and the air-sensitive reducing ligand DMPE under argon in ethanol-water. At acidic pH [Tc(III)Clsub(2) dmpesub(2)]sup(+) was formed, while alkaline pH led to the formation of 95% yield in less than 1 hour, otherwise the [Tc(V)Osub(2)dmpesub(2)]sup(+) intermediate was present. Electrophoresis demonstrated the unit positive charge and reversed-phase ion-pair HPLC provided separation and identification of sup(99m)Tc-products by direct comparison with known sup(99m)Tc-complexes. In rats the sup(99m)Tc-complexes were excrated by kidneys and liver and reached high heart/blood but only low heart/lung and heart/liver ratios. In dogs satisfactory myocardial scintigrams were obtained in spite of high liver activity. (author)

Evaluation of usefulness of Tc-99m-GSA liver scintigraphy in chronic liver diseases

International Nuclear Information System (INIS)

Fukui, Hiroyuki; Kashiwagi, Toru; Kasahara, Akinori

1991-01-01

Liver scintigraphy was performed using a newly developed radiopharmaceutical, Tc-99m-DTPA-galactosyl-human-serum-albumin (Tc-99m-GSA), which binds specifically to the receptors on the hepatic cell surface, in 15 patients with chronic liver disease. The scintigraphy was evaluated qualitatively and quantitatively, and the results were compared with those obtained from the Tc-99m-PMT or Tc-99m-sn-phytate scintigraphy, and the liver function tests. The Tc-99m-GSA scintigraphy showed clear liver images in chronic hepatitis. However, in liver cirrhosis, the liver images were not clear and the cardiac images still existed 40 minutes after administration of Tc-99m-GSA, suggesting that the image quality of the Tc-99m-GSA scintigrams may be inferior to that of Tc-99m-sn-phytate or Tc-99m-PMT in some cases of severe liver dysfunction. The time-activity curves of the heart and liver were analyzed by non-linear regression analysis. The clearance rate from plasma (Kd) were obtained from the time-activity curve of the heart, and the hepatic uptake rate (Ku), hepatic excretion rate (Ke) and peak time of hepatic uptake-excretion curve (PT) were obtained from the time-activity curve of the liver. Kd, Ku, and PT values were more significantly decreased or prolonged in the patients with chronic hepatitis. Kd, Ku, and PT values had positive correlations with the result of the serum liver function tests, ICG-R15 and ICG-K. Ku and PT values had also correlations with the histological degree of hepatic fibrosis. On the other hand, the indices obtained using Tc-99m-PMT or Tc-99m-sn-phytate did not have correlations with the histological degrees of hepatic fibrosis. It is concluded that the liver scintigraphy using Tc-99m-GSA may be useful and give different information from those with conventional liver scintigraphies in evaluating chronic liver diseases. (author)

Concentration of 99Tc in seawater by coprecipitation with iron hydroxide

International Nuclear Information System (INIS)

Momoshima, Noriyuki; Eto, Ichiro; Muhammad Sayad; Takashima, Yoshimasa

1991-01-01

A method for accumulation of 99 Tc in seawater has been developed. Technetium tracer in +VII oxidation state was added to the seawater together with reducing agent, potassium pyrosulfite, and coprecipitation agent, ferric chloride. After reduction of Tc(VII) at pH 4, Tc(IV) was coprecipitated as iron hydroxide by addition of sodium hydroxide to pH 9. The reduction and coprecipitation was quantitative and overall recovery of Tc was more than 98%. The green color of iron precipitate formed at pH 9 suggested that Tc(VII) as well as ferric ion was reduced under this condition. Adsorption of Tc(IV), however, was poor for iron hydroxide which was prepared in advance indicating active surface of freshly precipitated iron hydroxide is necessary for quantitative recovery of Tc(IV). A repeating coprecipitation technique was examined for enrichment of Tc in seawater that the same iron was used repeatedly as coprecipitater. After separation of iron hydroxide with Tc(IV) from supernatant, the precipitate was dissolved by addition of acid and then new seawater which contained reducing agent and Tc(VII) was added. Reduction and coprecipitation was again carried out. Good recovery was attained for 7 repeats. The proposed repeating coprecipitation technique was applicable to a large amount of seawater without increasing the amount of iron hydroxide which is subjected to radiochemical analysis. (author)

Seasonal variations in activity concentrations of 99Tc and 137Cs in the edible meat fraction of crabs and lobsters from the central Irish Sea.

Science.gov (United States)

Copplestone, D; Jackson, D; Hartnoll, R G; Johnson, M S; McDonald, P; Wood, N

2004-01-01

Discharges of most radionuclides into the Irish Sea from the BNFL site at Sellafield have decreased over the past 20 years or so. For a few radionuclides, however, discharges have peaked more recently. Notably, operation of the Enhanced Actinide Removal Plant (EARP) since 1994 has led to an increase in discharges of (99)Tc, as a result of the treatment of previously stored waste, with consequent increases in (99)Tc activity concentrations in a number of marine species, particularly in crustaceans such as lobsters. Previous research has considered the significance of factors such as sex and body weight on radionuclide concentrations. The current project set out to investigate whether seasonal variations in radionuclide concentrations in crabs and lobsters occur, with particular emphasis on the dynamics of (99)Tc and (137)Cs. Organisms were obtained from a site off the Isle of Man, where radionuclide concentrations were measurable but the site was sufficiently distant from Sellafield that the radionuclides were well mixed in the water column and not likely to be influenced by the pulsed nature of discharges of (99)Tc. Crab and lobster samples were collected monthly, between February 2000 and February 2001. Fifteen or 16 individuals (evenly split as male and female) of each species were collected on each occasion. Seawater samples were also collected over the 12-month period. Activity concentrations of (99)Tc in the edible meat fraction (both brown and white meat) ranged from 0.23 to 2.46 Bq kg(-1) (fresh weight (fw)) in crabs and 124 to 216 Bq kg(-1) (fw) in lobsters, with no observed seasonal variations. Activity concentrations of (137)Cs in both crab and lobster were lower, ranging from lobster meat (fw). A statistically significant increase in activity concentrations of (137)Cs in the meat was observed in the summer months for both crab and lobster. The cause has not been investigated but may be related to the laying down of energy reserves during the active

In vitro evaluation of canine leukocytes radiolabeled in whole blood with 99mTc stannous colloid

International Nuclear Information System (INIS)

Abushhiwa, Mohamed H.; Salehi, Nouria S.; Whitton, Robert C.; Charles, Jennifer A.; Finnin, Peter J.; Lording, Peter M.; Caple, Ivan W.; Parry, Bruce W.

2008-01-01

Introduction: Technetium-99m stannous colloid ( 99m TcSnC)-labeled leukocytes are used to investigate a variety of inflammatory diseases in human medicine. The present study investigates the in vitro behavior of canine leukocytes labeled in whole blood with 99m TcSnC. Methods: Blood samples from 10 healthy dogs were labeled with 99m TcSnC using a standard procedure. The distribution of radioactivity among blood components (plasma, leukocyte layers and erythrocytes) was measured following separation of the radiolabeled samples across Histopaque density gradients. Phagocytic function of labeled and unlabeled leukocytes was estimated using zymosan particles. Labeling retention by leukocytes was determined at 1, 3, 4 and 7 h postlabeling. Results: The mean±standard error percentage of radioactivity associated with plasma, erythrocyte and leukocyte fractions was 2.0±0.21%, 55.5±0.60% and 42.5±0.54%, respectively (the last comprising 70.2±0.83% in polymorphonuclear leukocytes and 29.8±0.83% in mononuclear leukocytes). Labeled canine leukocytes had a phagocytic activity of 91.3±0.28% (control, 91.7±0.26%). The radiolabeled canine leukocytes retained 94.1±0.30% of radioactivity at 7 h postlabeling. Conclusions: Radiolabeling of canine leukocytes in whole blood with 99m TcSnC has minor adverse effect on their phagocytic function. The radiolabeled canine leukocytes retained a large percentage of radioactivity for at least 7 h postlabeling

Synthesis and biological evaluation of a 99mTc-labelled cyclic RGD peptide for imaging the αvβ3 expression

International Nuclear Information System (INIS)

Haubner, F.; Bock, M.; Schwaiger, M.; Wester, H.J.; Bruchertseifer, F.; Kessler, H.

2004-01-01

Aim: The αvβ3 integrin is involved in tumour induced angiogenesis and tumour metastasis. We describe the synthesis and evaluation of a 99m Tc-labelled RGD analogue for the visualisation of αvβ3 integrin expression. Methods: The linear peptides were assembled on a solid support. Cyclisation was performed under high dilution conditions. For conjugation with the chelator peptide, a water soluble carbodiimide was used. Radiolabelling was carried out due to standard procedures with high radiochemical yield and radiochemical purity. For in vivo evaluation, nude mice bearing αvβ3-positive human melanoma M21 and αv-negative human melanoma M21-L or Balb / c mice bearing αv-positive murine osteosarcoma were used. Results: Activity accumulation of 99m Tc-DKCK-RGD 240 min p.i. was 1.1% ID/g in the αvβ3-positive melanoma and 0.3% ID/g in the negative control tumour. In the osteosarcoma model 2.2% ID/g was found 240 min p.i. Planar gamma camera images allowed contrasting visualisation of αvβ3-positive tumours 240 min p.i. Blocking of the tumour using the αvβ3-selective pentapeptide cyclo(-Arg-Gly-Asp-D-Phe-Val-) reduces activity accumulation in the tumour to background level. However, 240 min p.i. highest activity concentration was found in kidneys resulting in low tumour / kidney ratios. Metabolite analysis 240 min p.i. showed approximately 60% intact tracer in kidneys and 80% in the tumour. Only 24% intact tracer was found in blood 30 min p.i. Conclusion: 99m Tc-DKCK-RGD allows imaging of αvβ3-positive tumours in mice. However, pharmacokinetics as well as metabolic stability of the tracer have to be improved for potential clinical application. (orig.)

Assessing activation of hepatic stellate cells by 99mTc-3PRGD2 scintigraphy targeting integrin αvβ3: a feasibility study

International Nuclear Information System (INIS)

Zhang, Xin; Xin, Jun; Shi, Yu; Xu, Weina; Yu, Shupeng; Yang, Zhiguang; Liu, Changping; Cao, Li; Guo, Qiyong

2015-01-01

Objective: Hepatic stellate cell (HSC) activation, which is accompanied by increased expression of integrin αvβ3, is an important factor in liver fibrogenesis. Molecular imaging targeting the integrin αvβ3 could provide a non-invasive method for evaluating the expression and the function of the integrin αvβ3 on the activated HSCs (aHSCs) in the injured liver, and then provide important prognostic information. 99m Tc-3PRGD2 is such a radiotracer specific for integrin αvβ3. In this study, we aimed to compare the differences in liver uptake and retention of the 99m Tc-3PRGD2 between normal liver and injured liver to evaluate the feasibility of 99m Tc-3PRGD2 scintigraphy for this purpose. Methods: We used planar scintigraphy to assess changes in integrin αvβ3 binding of intravenously-administered 99m Tc-3PRGD2 in the livers of rats with thioacetamide (TAA)-induced liver fibrosis compared with the controls. We co-injected cold c(RGDyK) with 99m Tc-3PRGD2 to assess the specific binding of the radiotracer. We performed Sirius red staining to assess liver fibrosis, immunofluorescent colocalization to identify the location of integrin αvβ3 expressed in the fibrotic liver, and we measured protein and messenger RNA expression of integrin αvβ3 and alpha smooth muscle actin (α-SMA) in the control and fibrotic livers. Results: The fibrotic livers showed enhanced 99m Tc-3PRGD2 uptake and retention. The radiotracer was demonstrated to bind specifically with the integrin αvβ3 mainly expressed on the aHSCs. The liver-to-heart ratio at 30 min post-injection was higher in the fibrotic livers than in the control livers (TAA, 1.98 ± 0.08 vs. control, 1.50 ± 0.12, p < 0.01). The liver t 1/2 was longer than in the controls (TAA, 27.07 ± 10.69 min vs. control, 12.67 ± 4.10 min, p < 0.01). The difference of heart t 1/2 between the two groups was not statistically significant (TAA, 3.13 ± 0.63 min vs. control, 3.41 ± 0.77 min, p = 0.94). Conclusions: 99m Tc-3PRGD2

99mTc labeling of the scorpion (Tityus serrulatus) antivenom

International Nuclear Information System (INIS)

Cardoso, D.S.; Nunan, E.A.; Toledo, V.P.C.P.; Moraes-Santos, T.; Cardoso, V.N.

2008-01-01

F(ab') 2 is the fragment involved in the immunotherapy for scorpion stings and it would be convenient to label it with 99m Tc for organ distribution and pharmacokinetics studies. The aim of the present study was to label scorpion antivenom F(ab') 2 with 99m Tc keeping its biological activity, integrity and stability. High labeling yield was obtained using stannous chloride and sodium borohydride. Stability, immunoreactivity and integrity of 99m Tc-F(ab') 2 was preserved. It was not observed any difference between potencies of unlabeled and labeled antivenom. 99m Tc-F(ab') 2 can be a useful tool for use in biodistribution and pharmacokinetics studies on the evaluation of the efficacy of the antivenom against scorpion envenomation. (author)

Quality control of a detector for the calculations of radiopharmacokinetic parameters of 99mTc-glucarate in rats

International Nuclear Information System (INIS)

Molina-Trinidad, E.M.; Arteaga de Murphy, C.; Jung-Cook, H.

2004-01-01

Good manufacturing practices specify that a well-type scintillation NaI(Tl) crystal detector has to be validated in order to detect radioactivity from any radiopharmaceutical used to obtain radiopharmacokinetic parameters. A 5 cm well-type NaI(Tl) scintillation detector was coupled to a multi-channel analyzer centered at the 140 keV 99m Tc peak with a 20% window. The area represents counts per minute (cpm). All the net cpm were decay corrected. The activity source was 99m Tc-glucarate developed as an imaging agent for acute myocardial infarction. Wistar rats were injected in a tail vein with 0.1 ml (3.7 MBq) of 99m Tc-glucarate solution and 13 blood samples were taken. The cpm were the input data for the WINNONLN program which calculates radiopharmacokinetic parameters. The detector's efficiency for 99m Tc was 15.03% and the sensitivity 1.12 kBq/ml in plasma. The response was linear between 0.31-14.3 kBq/ml of 99m Tc-glucarate. The maximum assay variation coefficient was 2.79 and recovery of 99m Tc-glucarate in plasma was 99.8% ± 0.2%. LOD was 0.31 kBq and LOQ 1.12 kBq in plasma samples. 99m Tc-glucarate follows a two-compartment model of distribution with Vd of 21.74 ml ± 2.71 ml; a Vdss of 74.36 ml ± 12.67 ml; t 1/2α 0.74 h ± 0.19 h; t 1/2β 18.98 h ± 4.36 h; AUC = 32.75 μCi/min x ml ± 3.73 μCi/min x ml; MRT 24.35 h ± 5.51 h and total clearance 3.05 ml/h ±0.35 ml/h. The well-type detector fulfills the quality system requirements and the radiopharmacokinetic parameters for 99m Tc-glucarate in rats are reliable. (author)

Comparison of uptake of 99mTc-MIBI, 99mTc-tetrofosmin and 99mT-Q12 into human breast cancer cell lines

International Nuclear Information System (INIS)

Yong, M. de; Bernard, B.F.; Breeman, W.A.P.; Ensing, G.; Benjamins, H.; Bakker, W.H.; Visser, T.J.; Krenning, E.P.

1996-01-01

Technetium-99m hexakis-2-methoxyisobutyl-isonitrile (MIBI), 99m Tc-tetrofosmin and 99m Tc-Q12 were all introduced for myocardial imaging but found additional applications as they are taken up by different tumours, enabling imaging of these lesions in patients. The aim of this study was to compare the uptake characteristics of these compounds in vitro in the human adenocarcinoma breast cell lines MCF-7 and ZR-75. It was shown that 99m Tc-MIBI had the highest cellular uptake (15.9%±0.5% dose/mg protein after 60 min in MCF-7, and 14.2%±0.4% dose/mg protein in ZR-75), followed by 99m Tc-tetrofosmin (6.8%±0.6% dose/mg protein in MCF-7, and 8.2%±0.2% dose/mg protein in ZR-75) and 99m TC-Q12 (3.2%±0.1% dose/mg protein in MCF-7, and 3.5%±0.3% dose/mg protein in ZR-75 cells). For all three compounds tenfold differences in specific activity did not influence total cell-associated radioactivity. Uptake of 99m Tc-MIBI and 99m Tc-tetrofosmin was obviously lower at 4 C than at 37 C, whereas 99m Tc-Q12 uptake showed only slight temperature dependence. When uptake was compared in cells grown to different cell densities (1 mg/ml cellular protein versus 0.3 mg/ml), no differences in uptake were detected when uptake was corrected for the amount of cellular protein present in the dishes. Furthermore, for all compounds it was shown that cellular radioactivity decreased rapidly after washing. Apart from the differences in cellular uptake of the three compounds after 60 min, no differences in residual cellular radioactivity after washing were found between the different compounds when expressed as a percentage of their 60-min uptake, suggesting that the efflux process of the radiolabelled compounds was similar. The differences in cell-associated activity after 60 min were thus presumably caused by differences in uptake. (orig./MG)

Tc-99m sucralfate scanning for inflammatory bowel disease

International Nuclear Information System (INIS)

Lieberman, L.M.; Becker, S.; Mekhmandarov, S.; Steinmetz, A.

1987-01-01

The authors investigated 14 patients with idiopathic inflammatory bowel disease (IBD) by administering Tc-99m sucralfate (TcS) orally and imaging the abdomen 4 and 24 hours after dose. All patients had either barium radiographic studies or colonoscopy before the scan. The scan identified seven of nine patients who had radiologically demonstrated small-bowel lesions and four of five patients with colonic disease. The authors' preliminary experience suggests that TcS maybe a useful procedure to document location and extent of active disease. It provides information about both small and large bowel in one procedure, is noninvasive, easy to perform, and has low radiation absorbed dose

Leaching Tc-99 from SRP glass in simulated tuff and salt groundwaters

International Nuclear Information System (INIS)

Bibler, N.E.; Jurgensen, A.R.

1987-01-01

Results of leach tests with Tc-99 doped SRP borosilicate waste glass are presented. The glass was prepared by melting a mixture of SRP 165 powdered frit doped with a carrier free solution of Tc-99 at 1150 0 C. Dissolution of portions of the resulting glass indicated that the Tc-99 was distributed homogeneously throughout the glass. Static leach tests up to 90 days were performed at 90 0 C in J-13 tuff groundwater or WIPP brine A at a SA/V of 100m -1 . Normalized mass losses were calculated for Tc-99 as well as all the major elements in the glass. Results indicated that under ambient oxidizing conditions Tc-99 leached no faster than the glass-forming elements of the glass. In J-13 water, Tc-99 leached congruently with B. In WIPP brine A, it leached congruently with Si. Leach rates for Li were higher in both groundwaters, probably due to a contribution from an ion exchange mechanism. Leach tests were performed under reducing conditions in J-13 water by adding Zn/Hg amalgam to the leachate. In these tests the pH increased significantly, probably because of the reaction of the amalgam with the water. In a 21-day test, the pH increased to 13 and leach rates for the glass were very high. Even though there was signifcant dissolution of the glass, the normalized mass loss based on Tc-99 was only 0.02g/m 2 . This result and the fact that reducing conditions at normal pH values do not significantly affect the dissolution of the glass, indicate that the low concentrations for Tc-99 obtained under reducing conditions are due to is solubility and not due to an increased durability of the glass. 14 refs., 2 figs., 5 tabs

On the separation of 99mTcO4-, 99mTc-DTPA and 99mTc-citrate as marker species for the determination of Tc chemical forms in plant material using capillary zone electrophoresis

NARCIS (Netherlands)

Krijger, G.C.; Claessens, H.A.; Wolterbeek, H.Th.

1996-01-01

The present paper addresses the potential use of capillary zone electrophoresis (CZE) as an anal. tool in 99Tc speciation studies. To optimize sampling, storage and anal. procedures, the three marker compds. 99mTcO4-, 99mTc-DTPA and 99mTc-citrate were synthesized and used in test-measurements with

(99) Tc-methylene diphosphonate improves rheumatoid arthritis disease activity by increasing the frequency of peripheral γδ T cells and CD4(+) CD25(+) Foxp3(+) Tregs.

Science.gov (United States)

Su, Dinglei; Shen, Minning; Gu, Bingjie; Wang, Xiaoqin; Wang, Dandan; Li, Xia; Sun, Lingyun

2016-06-01

γδ T cells exhibit important functions in the pathogenesis of rheumatoid arthritis (RA). In recent years, numerous studies harnessed the γδ T cell-activating capacity of aminobiphosphonates for the treatment of malignant tumors. As (99) Tc-methylene diphosphonate ((99) Tc-MDP) has long been widely used for the treatment of RA in China with good efficacy, we are interested in whether this drug exerts its therapeutic effect on RA by modulating peripheral γδ T cells of RA patients. To investigate the effect of (99) Tc-MDP on the frequency of γδ T cells and CD4(+) CD25(+) Foxp3(+) Tregs in the peripheral blood of patients with active RA. Nineteen patients with active RA were treated with (99) Tc-MDP intravenously at a dose of 20 μg/day consecutively for 10-14 days. Before and after treatment, the main clinical and laboratory parameters for each patient were evaluated. The frequency of CD3(+) γδ(+) T cells and CD4(+) CD25(+) Foxp3(+) Tregs was detected by flow cytometry. Serum levels of interferon (IFN)-γ, tumor necrosis factor (TNF)-α, interleukin (IL)-6, IL-10 and transforming growth factor (TGF)-β were measured with enzyme-linked immunosorbent assay. After intravenous (99) Tc-MDP therapy, the frequency of peripheral CD3(+) γδ(+) T cells and CD4(+) CD25(+) Foxp3(+) Tregs were significantly elevated, paralleled with decreased serum levels of TNF-α and IL-6 and increased level of serum TGF-β. The elevation of peripheral CD3(+) γδ(+) T cells was positively correlated with increased serum TGF-β and decreased disease activity. (99) Tc-MDP may improve the activity of RA through upregulating the frequency of peripheral γδ T cells and CD4(+) CD25(+) Foxp3(+) Tregs as well as affecting the serum cytokine environment by increasing TGF-β and decreasing TNF-α and IL-6. © 2014 Asia Pacific League of Associations for Rheumatology and Wiley Publishing Asia Pty Ltd.

Dynamic radionuclide imaging with 99mTc-sucralfate in the detection of oesophageal ulceration.

Science.gov (United States)

Mearns, A J; Hart, G C; Cox, J A

1989-01-01

Standard oesophageal scintigraphic techniques using 99mTc-colloids rarely identify oesophageal mucosal damage. Sucralfate can be labelled with 99mTc for the detection of oesophageal mucosal ulceration. This method uses two separate supine swallows of 10 MBq 99mTc-colloid in 10 ml, followed by a single supine swallow of 30 MBq 99mTc-sucralfate. The data are processed to give time-activity curves, mean transit times and condensed dynamic images. When oesophageal ulceration is detected, the time-activity curves using sucralfate show residual activity in the oesophagus after the transit time indicated by the colloid swallow. The condensed dynamic image shows a persistence of activity at the level of the ulceration. Erect sucralfate images taken immediately after the dynamic sequence show no oesophageal localisation. The results from a study of 62 patients have shown excellent correlation between the dynamic 99mTc-sucralfate images and endoscopy findings. Sequential sucralfate studies for healing also correlate well. The use of labelled sucralfate to detect oesophageal ulceration could modify the indications for endoscopy in gastrooesophageal reflux disease. Images Fig. 1 Fig. 2 Fig. 3 Fig. 4 Fig. 5 PMID:2806994

Cross-sections for formation of 99mTc through natRu(n,x) 99mTc reaction induced by neutrons at 13.5 and 14.8 MeV

International Nuclear Information System (INIS)

Luo Junhua; Han Jiuning; Tuo Fei; Kong Xiangzhong; Liu Rong; Jiang Li

2012-01-01

The cross-sections for formation of metastable state of 99 Tc ( 99m Tc, 140.511 keV, 6.01 h) through nat Ru(n,x) 99m Tc reaction induced by 13.5 MeV and 14.8 MeV neutrons were measured. Fast neutrons were produced via the 3 H(d,n) 4 He reaction on the K-400 neutron generator. Induced gamma activities were measured by a high-resolution gamma-ray spectrometer with a high-purity germanium (HpGe) detector. Measurements were corrected for gamma-ray attenuations, dead time and fluctuation of neutron flux. Data for nat Ru(n,x) 99m Tc reaction cross sections are reported to be 9.6±1.5 and 9.2±1.1 mb at 13.5±0.2 and 14.8±0.2 MeV incident neutron energies, respectively. Results were compared with the data by other authors. - Highlights: ► D–T neutron source was used to measure cross sections using activation method. ► 27 Al(n,α) 24 Na was used as the monitor for the measurement. ► Cross-sections for formation of 99m Tc through nat Ru(n,x) 99m Tc were measured. ► Data for nat Ru(n,x) 99m Tc reaction cross sections are reported. ► The results were discussed and compared with experimental data in the literature.

Clinical evaluation of Tc-99m-mebrofenin and comparison with Tc-disofenin for radionuclide hepatobiliary imaging

International Nuclear Information System (INIS)

Klingensmith, W. III; Fritzberg, A.; Spitzer, V.

1982-01-01

The clinical comparison reported indicates that Tc-mebrofenin has a significantly lower level of renal excretion that Tc-disofenin at all bilirubin levels. At a total bilirubin level of 25 mg/dl the renal excretion of Tc-mebrofenin is still less than the renal excretion of Tc-disofenin in subjects with normal bilirubin levels. In addition, renal radioactivity in images was never seen in subjects with normal bilirubins while visualization of renal radioactivity is routine in normal subjects with Tc-disofenin. No significant differences were found in any other parameter including hepatocyte extraction efficiency, time of maximum hepatic radioactivity, and hepatic parenchymal washout. This study indicates that Tc-mebrofenin is equal to Tc-disofenin in its hepatobiliary characteristics and superior in its renal characteristics

Interleukin 21 and its receptor are involved in NK cell expansion and regulation of lymphocyte function.

Science.gov (United States)

Parrish-Novak, J; Dillon, S R; Nelson, A; Hammond, A; Sprecher, C; Gross, J A; Johnston, J; Madden, K; Xu, W; West, J; Schrader, S; Burkhead, S; Heipel, M; Brandt, C; Kuijper, J L; Kramer, J; Conklin, D; Presnell, S R; Berry, J; Shiota, F; Bort, S; Hambly, K; Mudri, S; Clegg, C; Moore, M; Grant, F J; Lofton-Day, C; Gilbert, T; Rayond, F; Ching, A; Yao, L; Smith, D; Webster, P; Whitmore, T; Maurer, M; Kaushansky, K; Holly, R D; Foster, D

2000-11-02

Cytokines are important in the regulation of haematopoiesis and immune responses, and can influence lymphocyte development. Here we have identified a class I cytokine receptor that is selectively expressed in lymphoid tissues and is capable of signal transduction. The full-length receptor was expressed in BaF3 cells, which created a functional assay for ligand detection and cloning. Conditioned media from activated human CD3+ T cells supported proliferation of the assay cell line. We constructed a complementary DNA expression library from activated human CD3+ T cells, and identified a cytokine with a four-helix-bundle structure using functional cloning. This cytokine is most closely related to IL2 and IL15, and has been designated IL21 with the receptor designated IL21 R. In vitro assays suggest that IL21 has a role in the proliferation and maturation of natural killer (NK) cell populations from bone marrow, in the proliferation of mature B-cell populations co-stimulated with anti-CD40, and in the proliferation of T cells co-stimulated with anti-CD3.

Isolation and activity determination of 99Tc in nuclear waste by liquid scintillation counting

International Nuclear Information System (INIS)

Reis Junior, Aluisio S.; Temba, Eliane S.C.; Kastner, Geraldo F.; Monteiro, Roberto P.G.

2011-01-01

A radiochemical separation and purification for technetium was proposed for radioactive waste in which rhenium is to be used as a yield monitor. The separation was performed by anion exchange chromatography and the purification was performed by extraction chromatography using a TEVA resin.The determination of 99 Tc was by liquid scintillation counting and rhenium was activated by Triga Mark 1 research reactor and measured by gamma spectrometry. Some real samples of nuclear waste such as evaporator concentrate and filter were analysed. The chemical recovery determined using rhenium as tracer was around 90 %. (author)

The function of Sn(II)-apatite as a Tc immobilizing agent

Energy Technology Data Exchange (ETDEWEB)

Asmussen, R. Matthew, E-mail: matthew.asmussen@pnnl.gov [Energy and Environment Directorate, Pacific Northwest National Laboratory, 902 Battelle Blvd, Richland, WA, 99352 (United States); Neeway, James J.; Lawter, Amanda R.; Levitskaia, Tatiana G. [Energy and Environment Directorate, Pacific Northwest National Laboratory, 902 Battelle Blvd, Richland, WA, 99352 (United States); Lukens, Wayne W. [Chemical Sciences Division, Lawrence Berkeley National Laboratory, Berkeley, CA, 94720 (United States); Qafoku, Nikolla P. [Energy and Environment Directorate, Pacific Northwest National Laboratory, 902 Battelle Blvd, Richland, WA, 99352 (United States)

2016-11-15

At the U.S. Department of Energy Hanford Site, Tc-99 is a component of low-activity waste (LAW) fractions of the nuclear tank waste and removal of Tc from LAW streams would greatly benefit the site remediation process. In this study, we investigated the removal of Tc(VII), as pertechnetate, from deionized water (DIW) and a LAW simulant through batch sorption testing and solid phase characterization using tin (II) apatite (Sn-A) and SnCl{sub 2}. Sn-A showed higher levels of Tc removal from both DIW and LAW simulant. Scanning electron microscopy/energy dispersive X-ray spectroscopy (SEM/XEDS) and X-ray absorption spectroscopy (XAS) of reacted Sn-A in DIW showed that TcO4- is reduced to Tc(IV) on the Sn-A surface. The performance of Sn-A in the LAW simulant was lowered due to a combined effect of the high alkalinity, which lead to an increased dissolution of Sn from the Sn-A, and a preference for the reduction of Cr(VI). - Highlights: • Sn(II)-Apatite shows high proficiency in removing Tc(VII) from neutral solutions. • The removal of the Tc(VII) by Sn(II)-apatite is done via reduction to Tc(IV)O{sub 2} × H{sub 2}O. • In LAW Sn(II)-apatite is less efficient in removing Tc(VII). • Interference in LAW due to a preference for the reduction of Cr(VI) and the high pH. • Sn(II)-apatite can remove Tc(VII) from LAW effectively through increasing material added.

Solubility study of Tc(Ⅳ) in a granitic water

International Nuclear Information System (INIS)

Liu Dejun; Yao Jun; Wang Bo

2008-01-01

The deep geological disposal of the high level radioactive wastes is expected to be a safe disposal method in most countries. The long-lived fission product 99 Tc is present in large quantities in nuclear wastes and its chemical behavior in aqueous solution is of considerable interest. Under oxidizing conditions technetium exists as the anionic species TcO 4 - whereas under the reducing conditions, expected to exist in a deep geological repository, it is generally predicted that technetium will be present as TcO 2 -nH 2 O. Hence, the mobility of Tc(Ⅳ) in reducing groundwater may be limited by the solubility of TcO 2 ·nH 2 O under these conditions. Due to this fact it is important to investigate the solubility of TcO 2 ·nH 2 O. The solubility determines the release of radionuclides from waste form and is used as a source term in radionuclide migration analysis in performance assessment of radioactive waste repository. Technetium (Ⅳ) was prepared by reduction of a technetate solution with Sn 2+ . The solubility of Tc(Ⅳ) has been determined in simulated groundwater and redistilled water under aerobic and anaerobic conditions. The effects of pH and CO 3 2- concentration of solution on solubility of Tc(Ⅳ) were studied. The concentration of total technetium and Tc(Ⅳ) species in the solutions were periodically determined by separating the oxidized and reduced technetium species using a solvent extraction procedure and counting the beta activity of the 99 Tc with a liquid scintillation counter. The experimental results show that the rate of oxidation of Tc(Ⅳ) in simulated groundwater and redistilled water is about (1.49-1.86)x10 -9 mol·L -1 d -1 under aerobic conditions, while no Tc(Ⅳ) oxidation was detected in simulated groundwater and redistilled water under anaerobic conditions. Under aerobic or anaerobic conditions the solubility of Tc(Ⅳ) in simulated groundwater and redistilled water is equal on the whole after centrifugation or ultrafiltration. The

Development of a measurement device, using a Geiger-Mueller type detector, for the determination of the activity in a 99mTc generator prototype

International Nuclear Information System (INIS)

Urquizo, Rafael; Gago, Javier; Mendoza, Pablo; Cruz-Saco, Cesar; Rojas, Jorge

2014-01-01

This article presents the implementation of a measurement system using a Geiger-Mueller detector (GM) in order to adapt it into a 99m Tc generator prototype. The response signal of the measurement system designed in terms of count rate is linearly proportional to the variation of the activity measured between 280 and 170 mCi of 99m Tc with a relative error of ± 2,8 %. However, further tests are needed to evaluate the correlation for an activity level lower than 20 mCi in order to obtain an adequate range of use. (authors).

Trypanosoma cruzi 80 kDa prolyl oligopeptidase (Tc80 as a novel immunogen for Chagas disease vaccine.

Directory of Open Access Journals (Sweden)

Augusto E Bivona

2018-03-01

Full Text Available Chagas disease, also known as American Trypanosomiasis, is a chronic parasitic disease caused by the flagellated protozoan Trypanosoma cruzi that affects about 8 million people around the world where more than 25 million are at risk of contracting the infection. Despite of being endemic on 21 Latin-American countries, Chagas disease has become a global concern due to migratory movements. Unfortunately, available drugs for the treatment have several limitations and they are generally administered during the chronic phase of the infection, when its efficacy is considered controversial. Thus, prophylactic and/or therapeutic vaccines are emerging as interesting control alternatives. In this work, we proposed Trypanosoma cruzi 80 kDa prolyl oligopeptidase (Tc80 as a new antigen for vaccine development against Chagas disease.In a murine model, we analyzed the immune response triggered by different immunization protocols based on Tc80 and evaluated their ability to confer protection against a challenge with the parasite. Immunized mice developed Tc80-specific antibodies which were able to carry out different functions such as: enzymatic inhibition, neutralization of parasite infection and complement-mediated lysis of trypomastigotes. Furthermore, vaccinated mice elicited strong cell-mediated immunity. Spleen cells from immunized mice proliferated and secreted Th1 cytokines (IL-2, IFN-γ and TNF-α upon re-stimulation with rTc80. Moreover, we found Tc80-specific polyfunctional CD4 T cells, and cytotoxic T lymphocyte activity against one Tc80 MHC-I peptide. Immunization protocols conferred protection against a T. cruzi lethal challenge. Immunized groups showed a decreased parasitemia and higher survival rate compared with non-immunized control mice. Moreover, during the chronic phase of the infection, immunized mice presented: lower levels of myopathy-linked enzymes, parasite burden, electrocardiographic disorders and inflammatory cells.Considering that

Hepatic mTORC1 controls locomotor activity, body temperature, and lipid metabolism through FGF21

Science.gov (United States)

Cornu, Marion; Oppliger, Wolfgang; Albert, Verena; Robitaille, Aaron M.; Trapani, Francesca; Quagliata, Luca; Fuhrer, Tobias; Sauer, Uwe; Terracciano, Luigi; Hall, Michael N.

2014-01-01

The liver is a key metabolic organ that controls whole-body physiology in response to nutrient availability. Mammalian target of rapamycin (mTOR) is a nutrient-activated kinase and central controller of growth and metabolism that is negatively regulated by the tumor suppressor tuberous sclerosis complex 1 (TSC1). To investigate the role of hepatic mTOR complex 1 (mTORC1) in whole-body physiology, we generated liver-specific Tsc1 (L-Tsc1 KO) knockout mice. L-Tsc1 KO mice displayed reduced locomotor activity, body temperature, and hepatic triglyceride content in a rapamycin-sensitive manner. Ectopic activation of mTORC1 also caused depletion of hepatic and plasma glutamine, leading to peroxisome proliferator–activated receptor γ coactivator-1α (PGC-1α)–dependent fibroblast growth factor 21 (FGF21) expression in the liver. Injection of glutamine or knockdown of PGC-1α or FGF21 in the liver suppressed the behavioral and metabolic defects due to mTORC1 activation. Thus, mTORC1 in the liver controls whole-body physiology through PGC-1α and FGF21. Finally, mTORC1 signaling correlated with FGF21 expression in human liver tumors, suggesting that treatment of glutamine-addicted cancers with mTOR inhibitors might have beneficial effects at both the tumor and whole-body level. PMID:25082895

Different Tc response profiles are associated with survival in the murine lymphocytic choriomeningitis virus infection

DEFF Research Database (Denmark)

Thomsen, Allan Randrup; Marker, O; Pfau, C J

1987-01-01

to produce early and high virus-specific Tc activity. However, in the present studies we demonstrate that even though this holds true in many mouse/virus combinations, it does not apply in others. Thus, in C3H mice infected with (moderately) high doses of Traub strain LCMV, early and high Tc activity...... was found despite a mortality rate of only 10-20%. Similarly, in C3H mice inoculated with the aggressive and docile substrains of UBC strain LCMV, which differ markedly in their pathogenicity for this mouse strain, similar kinetics of Tc induction were observed. Finally, in DBA/2 mice which do not die...... following infection with the otherwise lethal aggressive substrain, Tc induction could be found to be as efficient as in BALB/c mice, all of which die from acute LCM disease when infected with this virus isolate. The results indicate, therefore, that early and high Tc activity does not constitute...

Single isotope dual-phase scintigraphy with 99mTc-MIBI and 99mTc-tetrofosmin combined with SPECT technique in patients with secondary hyperparathyroidism

International Nuclear Information System (INIS)

Botushanova, A.; Yaneva, M.; Botushanov, N.

2015-01-01

Full text: Preoperative parathyroid scintigraphy is highly beneficial when used for minimally invasive parathyroidectomy. The aim is to examine the diagnostic value of single isotope dual-phase scintigraphy with 99mTc-MIBI and 99mTc-etrofosmin combined with SPECT technique in preoperative localization of hyperplastic parathyroid glands in patients with secondary hyperparathyroidism. The study included 15 patients aged 37 to 73 years (8 women and 7 men) with proven secondary hyperparathyroidism with increased serum calcium and parathyroid hormone. All patients were on chroniodialysis and treatment with Calcitriol. The examination was done with two-headed SPECT gamma camera SIMBIA by protocol for single isotope dual-phase scintigraphy and SPECT technique. 740 MBq 99mTc-MIBI were applied intravenously in 6 of the patients, and in 9 patients were administered 740 MBq 99mTc-tetrofosmin. The scintigraphy with 99mTc-MIBI visualized a focus of residual activity in 4 patients, and in 2 we received negative scintigraphy. The scintigraphy with 99mTc-tetrofosmin combined with SPECT showed an area of hyperfixation in both phases on SPECT images in 1 patient. In 2 patients hyperfixating areas suspicious for abnormal parathyroid glands were registered only in the early SPECT images. In 6 patients the scintigraphic results were negative. Negative scintigraphic results can be explained with the ability to suppress the uptake of 99mTc-MIBI and 99mTc - tetrofosmin by the parathyroid cells as a result of taking Calcitriol. Scintigraphy with 99mTc-MIBI and 99mTc-tetrofosmin did not show high sensitivity in identifying the hyperplastic parathyroid glands, although it was capable to distinguish patients with nodular hyperplasia of those with diffuse hyperplasia

Solubility study of Tc(IV) in a granitic water

International Nuclear Information System (INIS)

Liu, D.J.; Yao, J.; Wang, B.; Bruggeman, C.; Maes, N.

2007-01-01

The deep geological disposal of the high level radioactive wastes is expected to be a safe disposal method in most countries. The long-lived fission product 99 Tc is present in large quantities in nuclear wastes and its chemical behavior in aqueous solution is of considerable interest. Under oxidizing conditions technetium exists as the anionic species TcO 4 - whereas under the reducing conditions, expected to exist in a deep geological repository, it is generally predicted that technetium will be present as TcO 2 .nH 2 O. Hence, the mobility of Tc(IV) in reducing groundwater may be limited by the solubility of TcO 2 .nH 2 O under these conditions. Due to this fact it is important to investigate the solubility of TcO 2 .nH 2 O. The solubility determines the release of radionuclides from waste form and is used as a source term in radionuclide migration analysis in performance assessment of radioactive waste repository. Technetium(IV) was prepared by reduction of a technetate solution with Sn 2+ . The solubility of Tc(IV) has been determined in simulated groundwater and redistilled water under aerobic and anaerobic conditions. The effects of pH and CO 3 2- concentration of solution on solubility of Tc(IV) were studied. The concentration of total technetium and Tc(IV) species in the solutions were periodically determined by separating the oxidized and reduced technetium species using a solvent extraction procedure and counting the beta activity of the 99 Tc with a liquid scintillation counter. The experimental results show that the rate of oxidation of Tc(IV) in simulated groundwater and redistilled water is about (1.49 ∝ 1.86) x 10 -9 mol L -1 d -1 under aerobic conditions, while no Tc(IV) oxidation was detected in simulated groundwater and redistilled water under anaerobic conditions. Under aerobic or anaerobic conditions the solubility of Tc(IV) in simulated groundwater and redistilled water is equal on the whole after centrifugation or ultrafiltration. The

99mTc-diethyl-IDA chloescintigraphy

International Nuclear Information System (INIS)

Kim, J. W.; Oh, K. C.; Bae, B. H.; Kim, Y. S.; Park, B. H.

1981-01-01

For many years, 131 I-rose bengal has been used as the main hepatobiliary radiopharmaceutical. The undesirable physical characteristics of the radioiodine, however, finally prevented its widespread use in clinical medicine. In recent years, a number of hepatobiliary radiopharmaceuticals employing 99m Tc and 123 I as indicator have been introduced. 99m Tc-diethyl-IDA is a most promising one in these agents. Cholescintigraphy, using 99m Tc-diethyl-IDA was performed in 10 normal subjects and 32 patients suffering from various hepatobiliary disturbances, from Sep. -'79 to Aug-' 80, at the department of radiology, Maryknoll Hospital. The following results are obtained: 1. In normal fasting subjects, the liver, GB, CBD, and the proximal portion of small bowel are clearly delineated within 30 min after the injection. After a fatty meal, the radioactivity of the liver and CBD is notably disappeared with increase of the activity in GB and small bowel. 2. A dilatation of the main biliary ducts is a pathognomomic sign of partial mechanical obstructive disorders and a key point of D.Dx from hepatocellular disorders. 3. In cases of complete biliary obstruction, the radioactivity of the liver, CBD, and small bowel is not separated and the background activity is markedly increased. The kidneys are well visualized. 4. In severe hyperbilirubinaemia of above 10mg%, this method is not valuable

99mTc-HMPAO labeled leucocyte, 99mTc-labeled antigranulocyte antibody and 67Ga scintigraphy in the evaluation of painful hip and knee prosthetic replacements

International Nuclear Information System (INIS)

Oliveira, S.; Pereira, L.; Joao, F.; Lima, J.

2003-01-01

Full text: Objective: To evaluate the utility of 99mTc-HMPAO labeled leucocyte, 99mTc-labeled anti-granulocyte antibody and 67Ga scintigraphy in patients suspected to have infected hip and knee replacements, from March/1998 to March/ 2002. Methods: Retrospective study of 33 patients (12 male, 21 female) with an average age of 61,1 ± 7,3 years. Nineteen had hip replacements and 14 were submitted to knee replacements. 99mTc-HMPAO labeled leucocyte scintigraphy was performed in 17 patients, 99mTc-labeled anti-granulocyte antibody scintigraphy in 13 patients and 67Ga scintigraphy in 3 patients. Twenty-six patients were also submitted to 3-phase 99mTc-MDP bone scintigraphy. Results were compared to those from studies with infection/inflammation agents. Concordant positive studies were considered to be a positive result for infection. A second study using 67Ga was also performed in 3 patients. Results: Diagnosis was based on surgical findings in 14 patients, pathologic study of biopsy specimen in 1 case and clinical/ imaging follow-up in 18 patients. Infection was detected in 22 cases and absent in 11. The conjoined evaluation of scintigraphic studies considered infection to be present in 20 cases and absent in 13. With infection/inflammation agents, 20 cases were positive (+) and 13 cases were negative (-). Using 99mTc-HMPAO labeled leucocytes, 12 cases were (+) and 5 cases were (-). With 99mTc-labeled anti-granulocyte antibodies, 8 cases were (+) and 5 were (-). With 67Ga, all 3 cases were (-). In patients with (+) studies using infection/ inflammation agents, a false positive case with 99mTc-HMPAO labeled leucocytes was reported. Two false negative cases were detected, both with 99mTc-labeled antigranulocyte antibodies, in patients with (-) studies. Regarding the studies with 99mTc-MDP, 24 were (+) and 2 were (-). Eighteen of these (+) cases were also (+) in studies with infection/inflammation agents, but 6 were (-) with these agents. Negative cases were also (-) in

Preoperative radiological diagnosis by 99mTc·MIBI-99mTc subtraction scintigraphy for primary hyperparathyroidism

International Nuclear Information System (INIS)

Inouye, Takahiro; Tomita, Toshiki; Shinden, Seiichi; Takagi, Hitoshi; Kano, Shigeru.

1996-01-01

Preoperative radiological diagnosis constitutes the most important factor for the surgical treatment of hyperparathyroidism. In this regard, MRI is useful for detecting the abnormal parathyroid, but it is often difficult to localize it using MRI only. It is thus necessary to combine this procedure with excellent subtraction scintigraphy. We performed both 201 Tl- 99m Tc and 99m Tc·MIBI- 99m Tc subtraction scintigraphy in seven patients with primary hyperparathyroidism and compared them the radiological results. Five patients presented parathyroid adenomas and the rest hypertrophy of the parathyroid. We could detect the abnormal parathyroid in four patients (57.1%) by 201 Tl- 99m Tc subtraction scintigraphy and in six patients (85.7%) by 99m Tc·MIBI- 99m Tc subtraction scintigraphy. We therefore believe that 99m Tc·MIBI- 99m Tc subtraction scintigraphy will become an essential examination for primary hyperparathyroidism rather than the presently employed 201 Tl- 99m Tc subtraction scintigraphy. (author)

Evaluation by scintigraphic images of musculoskeletal infection with 99mTc ciprofloxacin

International Nuclear Information System (INIS)

Casacó, C.A.; Hernández, A.; Perera, A.; Prats, A.; Batista, J.F.; Torres, L.A.; Quesada, R.; Sánchez, Y.; Valladares, L.; Sánchez, E.L.; Marrero, L.O.; Mustelier, E.

2016-01-01

Introduction: Infectious diseases present high morbidity and mortality in all countries, especially in the third world. In Cuba between 2005 and 2014, approximately 1.3% of the total deaths were killed. Orthopedic infections are among the most common. The scintigraphic methods currently used are not able to discern between a septic focus and a sterile inflammation. Radiological methods detect a bone infection only when there is significant anatomical damage. Ciprofloxacin as a drug binds and inhibits topoisomerase II or bacterial gyrase DNA. Objective: to evaluate the efficacy of 99m Tc-ciprofloxacin in the detection of osteo-articular bacterial processes. Materials and Methods: An experimental, cross-sectional, cross-sectional study was conducted involving 258 patients with suspected osteoarticular infectious processes. The presence of the lesion and the quantification and intensity of uptake in the foci of infection in images with 99m Tc-MDP (3h post-administration) and 99m Tc-ciprofloxacin (1, 4 and 24h post-administration) were visually determined. Studies of 99m Tc-ciprofloxacin were compared with Culture / Biopsy results. Results: The germ that most frequently appears in infected osteo-articular sites is staphilococcusaureus. No adverse effects were detected in any of the subjects studied. Studies with 99m Tc-MDP allow delineating infected areas but are not specific. 99mTc-ciprofloxacin shows the sites of active osteo-articular bacterial infection and when it is fixed in a septic focus gives intense captures at both 4 and 24 hours. It exhibits a sensitivity similar to 99mTc-MDP, but a significantly higher specificity. Conclusions: Scintigraphic images with 99m Tc-ciprofloxacin show sites of active osteo-articular bacterial infection with a specificity significantly higher than 99m Tc-MDP. The microbiological and scintigraphic results were positive for sepsis in 122 patients out of 219 who were sampled.

Quantitative assessment of therapeutic effects in the critically ischemic limb using 99mTc-diethylene-triamine-pentaacetic acid human serum albumin

International Nuclear Information System (INIS)

Kawanishi, Jun; Ohta, Takashi; Ishibashi, Hiroyuki; Sugimoto, Ikuo; Iwata, Hirohide; Takahashi, Masayuki; Yamada, Tetsuya; Hida, Noriyuki

2009-01-01

The purpose of this study was to investigate the reliability and limitations of a new radioisotope method using 99m Tc-diethylenetriamine-pentaacetic acid human serum albumin (Tc-99m-DTPA-HSA) and to evaluate the diagnostic ability of isotope infusion for assessing hemodynamic changes in the foot before and after treatment. Hemodynamic changes before and after treatment were assessed in 21 limbs with ulcer or gangrene, by analyzing changes in the time-activity curve, the uptake ratio, and the values obtained with noninvasive techniques. There were significant differences between each pair of the three types of time-activity curve and their uptake counts. The uptake ratio was correlated with ankle blood pressure (ABP) and toe blood pressure (TBP), but not with transcutaneous oxygen pressure (tcPO 2 ) or skin perfusion pressure (SPP). The hemodynamic change induced by pharmacotherapy was subtle, but that induced by arterial reconstruction was remarkable. Although there was not always a good correlation between the degree of hemodynamic change and the clinical outcome in limbs treated with pharmacotherapy, the hemodynamic change was quantitatively assessed. Our study suggests that this isotope technique is a useful quantitative method to evaluate hemodynamic change from a different perspective to conventional noninvasive methods. (author)

Participation in CEN TC 335 TC343 Chemical Test Methods. Final report; Deelname CEN TC 335 TC343 Chemical Testmethods. Eindrapportage

Energy Technology Data Exchange (ETDEWEB)

Bakker, F.P. [ECN Engineering en Services, Petten (Netherlands)

2006-12-15

An overview is given of the work that has been done on the standardization of methods for the characterization of biofuels and solid recovered fuels (SRF). For biofuels a complete set of prestandards is available, conversion of pre-standards to standards is in good progress. The development of a standard biocarbon content method based on the {sup 14}C isotope measurement is in good progress. This standard could be an important tool for carbon dioxide trading purposes. CEN is the European Commission for Standardization, TC 335 is the Technical Committee 335 on Solid Biofuels, and TC 343 is the Technical Committee on Solid Recovered Fuels. [Dutch] In de periode september 2005 tot december 2006 zijn Europese standaarden voor de karakterisering van biobrandstoffen beschikbaar gekomen. Voor een aantal parameters is nader onderzoek vereist en deels gaande. Dankzij de ervaring die in Nederland is opgedaan met Nationale Technische Afspraken (NTA's) voor vaste biobrandstoffen heeft onze bijdrage aan de Europese normering de invoering daarvan zeker bespoedigd. De 14C groendeel bepaling begint terrein te winnen en zal in de nabije toekomst ook bij verdere implementatie van het Kyoto protocol een rol gaan spelen. CEN is de European Commission for Standardization, TC 335 is de Technical Committee 335 over Solid Biofuels, en TC 343 is de Technical Committee over Solid Recovered Fuels.

Functional studies of TcRjl, a novel GTPase of Trypanosoma cruzi, reveals phenotypes related with MAPK activation during parasite differentiation and after heterologous expression in Drosophila model system

International Nuclear Information System (INIS)

Reis Monteiro dos-Santos, Guilherme Rodrigo; Fontenele, Marcio Ribeiro; Dias, Felipe de Almeida; Oliveira, Pedro Lagerblad de; Nepomuceno-Silva, José Luciano

2015-01-01

The life cycle of the protozoan parasite Trypanosoma cruzi comprises rounds of proliferative cycles and differentiation in distinct host environments. Ras GTPases are molecular switches that play pivotal regulatory functions in cell fate. Rjl is a novel GTPase with unknown function. Herein we show that TcRjl blocks in vivo cell differentiation. The forced expression of TcRjl leads to changes in the overall tyrosine protein phosphorylation profile of parasites. TcRjl expressing parasites sustained DNA synthesis regardless the external stimuli for differentiation. Heterologous expression in the Drosophila melanogaster genetic system strongly suggests a role from TcRjl protein in RTK-dependent pathways and MAPK activation.

Functional studies of TcRjl, a novel GTPase of Trypanosoma cruzi, reveals phenotypes related with MAPK activation during parasite differentiation and after heterologous expression in Drosophila model system

Energy Technology Data Exchange (ETDEWEB)

Reis Monteiro dos-Santos, Guilherme Rodrigo [Laboratório de Parasitologia Molecular, Instituto de Biofísica Carlos Chagas Filho, CCS, UFRJ, Rio de Janeiro (Brazil); Fontenele, Marcio Ribeiro [Laboratório de Biologia Molecular do Desenvolvimento Instituto de Ciências Biomédicas, CCS, UFRJ, Rio de Janeiro (Brazil); Dias, Felipe de Almeida [Laboratório de Bioquímica de Artrópodes Hematófagos, Instituto de Bioquímica Médica, CCS, UFRJ, Rio de Janeiro (Brazil); Oliveira, Pedro Lagerblad de [Laboratório de Bioquímica de Artrópodes Hematófagos, Instituto de Bioquímica Médica, CCS, UFRJ, Rio de Janeiro (Brazil); Instituto Nacional de Ciência e Tecnologia em Entomologia Molecular (INCT-EM) (Brazil); Nepomuceno-Silva, José Luciano [Laboratório Integrado de Bioquímica Hatisaburo Masuda, NUPEM/UFRJ, Pólo Barreto, Universidade Federal do Rio de Janeiro, Campus Macaé, Macaé (Brazil); and others

2015-11-06

The life cycle of the protozoan parasite Trypanosoma cruzi comprises rounds of proliferative cycles and differentiation in distinct host environments. Ras GTPases are molecular switches that play pivotal regulatory functions in cell fate. Rjl is a novel GTPase with unknown function. Herein we show that TcRjl blocks in vivo cell differentiation. The forced expression of TcRjl leads to changes in the overall tyrosine protein phosphorylation profile of parasites. TcRjl expressing parasites sustained DNA synthesis regardless the external stimuli for differentiation. Heterologous expression in the Drosophila melanogaster genetic system strongly suggests a role from TcRjl protein in RTK-dependent pathways and MAPK activation.

Vandellos 1 Graphite Solubilisation and Activity Determination of 36Cl, 99Tc and 129I

International Nuclear Information System (INIS)

Rodríguez Alcalá, Marina; Piña Lucas, Gabriel; López Gutiérrez, Jose María; Leganés Nieto, Jose Luis

2016-01-01

During the characterization processes of irradiate graphite performed in the dismantling of the UNGG NPP of Vandellós 1, and as a consequence of the sample treatment carried out for measuring the main radionuclides of interest included in the El Cabril inventory, it was not possible to measure the activity of 99 Tc, 129 I and 36 Cl. Further R&D projects have been developed to solve this issue and finally a proper sample treatment has been accomplished. (author)

Identification of novel mammalian hosts and Brazilian biome geographic distribution of Trypanosoma cruzi TcIII and TcIV.

Science.gov (United States)

Barros, Juliana Helena S; Xavier, Samanta Cristina C; Bilac, Daniele; Lima, Valdirene Santos; Dario, Maria Augusta; Jansen, Ana Maria

2017-08-01

Trypanosoma cruzi is a parasitic protozoan responsible for Chagas disease. Seven different Discrete Typing Units (DTUs) of T. cruzi are currently identified in nature: TcI-TcVI, and TcBat whose distribution patterns in nature, hosts/reservoirs and eco-epidemiological importance are still little known. Here, we present novel data on the geographic distribution and diversity of mammalian hosts and vectors of T. cruzi DTUs TcIII and TcIV. In this study, we analyzed 61 T. cruzi isolates obtained from 18 species of mammals (five orders) and two Hemiptera genera. Samples were collected from five Brazilian biomes (Pantanal, Caatinga, Cerrado, Atlantic Rainforest, and Amazon) previously characterized as Z3 or mixed infection (TcI-Z3) by mini-exon gene PCR. To identify TcIII and TcIV genotypes, we applied restriction fragment length polymorphism analysis to the PCR-amplified histone 3 gene. DTUs TcIII and TcIV were identified in single and mixed infections from wide dispersion throughout five Brazilian biomes studied, with TcIV being the most common. Pantanal was the biome that displayed the largest number of samples characterized as TcIII and TcIV in single and mixed infections, followed by Atlantic Rainforest and Amazon. Species from the Didelphimorphia order displayed the highest frequency of infection and were found in all five biomes. We report, for the first time, the infection of a species of the Artiodactyla order by DTU TcIII. In addition, we describe new host species: five mammals (marsupials and rodents) and two genera of Hemiptera. Our data indicate that DTUs TcIII and TcIV are more widespread and infect a larger number of mammalian species than previously thought. In addition, they are transmitted in restricted foci and cycles, but in different microhabitats and areas with distinct ecological profiles. Finally, we show that DTUs TcIII and TcIV do not present any specific association with biomes or host species. Copyright © 2017. Published by Elsevier B.V.

Microbial reduction of 99Tc in organic matter-rich soils

International Nuclear Information System (INIS)

Abdelouas, A.; Grambow, B.; Fattahi, M.; Andres, Y.; Leclerc-Cessac, E.

2005-01-01

For safety assessment purposes, it is necessary to study the mobility of long-lived radionuclides in the geosphere and the biosphere. Within this framework, we studied the behaviour of 99 Tc in biologically active organic matter-rich soils. To simulate the redox conditions in soils, we stimulated the growth of aerobic and facultative denitrifying and anaerobic sulphate-reducing bacteria (SRB). In the presence of either a pure culture of denitrifiers (Pseudomonas aeruginosa) or a consortium of soil denitrifiers, the solubility of TcO 4 - was not affected. The nonsorption of TcO 4 - onto bacteria was confirmed in biosorption experiments with washed cells of P. aeruginosa regardless of the pH. At the end of denitrification with indigenous denitrifiers in soil/water batch experiments, the redox potential (E H ) dropped and this was accompanied by an increase of Fe concentration in solution as a result of reduction of less soluble Fe(III) to Fe(II) from the soil particles. It is suggested that this is due to the growth of a consortium of anaerobic bacteria (e.g., Fe-reducing bacteria). The drop in E H was accompanied by a strong decrease in Tc concentration as a result of Tc(VII) reduction to Tc(IV). Thermodynamic calculations suggested the precipitation of TcO 2 . The stimulation of the growth of indigenous sulphate-reducing bacteria in soil/water systems led to even lower E H with final Tc concentration of 10 -8 M. Experiments with glass columns filled with soil reproduced the results obtained with batch cultures. Sequential chemical extraction of precipitated Tc in soils showed that this radionuclide is strongly immobilised within soil particles under anaerobic conditions. More than 90% of Tc is released together with organic matter (60-66%) and Fe-oxyhydroxides (23-31%). The present work shows that ubiquitous indigenous anaerobic bacteria in soils play a major role in Tc immobilisation. In addition, organic matter plays a key role in the stability of the reduced Tc

PAI-1–regulated miR-21 defines a novel age-associated fibrogenic pathway in muscular dystrophy

Science.gov (United States)

Ardite, Esther; Perdiguero, Eusebio; Vidal, Berta; Gutarra, Susana; Serrano, Antonio L.

2012-01-01

Disruption of skeletal muscle homeostasis by substitution with fibrotic tissue constitutes the principal cause of death in Duchenne muscular dystrophy (DMD) patients, yet the implicated fibrogenic mechanisms remain poorly understood. This study identifies the extracellular PAI-1/urokinase-type plasminogen activator (uPA) balance as an important regulator of microribonucleic acid (miR)–21 biogenesis, controlling age-associated muscle fibrosis and dystrophy progression. Genetic loss of PAI-1 in mdx dystrophic mice anticipated muscle fibrosis through these sequential mechanisms: the alteration of collagen metabolism by uPA-mediated proteolytic processing of transforming growth factor (TGF)–β in muscle fibroblasts and the activation of miR-21 expression, which inhibited phosphatase and tensin homologue and enhanced AKT signaling, thus endowing TGF-β with a remarkable cell proliferation–promoting potential. Age-associated fibrogenesis and muscle deterioration in mdx mice, as well as exacerbated dystrophy in young PAI-1−/− mdx mice, could be reversed by miR-21 or uPA-selective interference, whereas forced miR-21 overexpression aggravated disease severity. The PAI-1–miR-21 fibrogenic axis also appeared dysregulated in muscle of DMD patients, providing a basis for effectively targeting fibrosis and muscular dystrophies in currently untreatable individuals. PMID:22213800

Migration of 99Tc in a weak loess aquifer. A field column experiment

International Nuclear Information System (INIS)

Liu, C.L.; Wang, X.Y.; Wang, H.F.

2001-01-01

The migration of 99 Tc in a weak loess aquifer was investigated in-situ with undisturbed aquifer medium columns. The columns were obtained horizontally at a depth of 32∼36 m in an Underground Research Facility (URF). Quartz containing 3 H (HTO) and 99 Tc (in the form of 99 TcO 4 - ) was introduced into one end of the columns and the columns were covered tightly. Aquifer water was introduced into the columns directly from an experimental shaft in the UFR. Effluents from the columns were collected and the activity of 3 H and 99 Tc were determined with a liquid scintillation analyzer. The breakthrough curves of 3 H and 99 Tc indicate that 99 Tc migrates a little faster than that 3 H does in the aquifer. (author)

Synapses of Amphids Defective (SAD-A) Kinase Promotes Glucose-stimulated Insulin Secretion through Activation of p21-activated Kinase (PAK1) in Pancreatic β-Cells*

Science.gov (United States)

Nie, Jia; Sun, Chao; Faruque, Omar; Ye, Guangming; Li, Jia; Liang, Qiangrong; Chang, Zhijie; Yang, Wannian; Han, Xiao; Shi, Yuguang

2012-01-01

The p21-activated kinase-1 (PAK1) is implicated in regulation of insulin exocytosis as an effector of Rho GTPases. PAK1 is activated by the onset of glucose-stimulated insulin secretion (GSIS) through phosphorylation of Thr-423, a major activation site by Cdc42 and Rac1. However, the kinase(s) that phosphorylates PAK1 at Thr-423 in islet β-cells remains elusive. The present studies identified SAD-A (synapses of amphids defective), a member of AMP-activated protein kinase-related kinases exclusively expressed in brain and pancreas, as a key regulator of GSIS through activation of PAK1. We show that SAD-A directly binds to PAK1 through its kinase domain. The interaction is mediated by the p21-binding domain (PBD) of PAK1 and requires both kinases in an active conformation. The binding leads to direct phosphorylation of PAK1 at Thr-423 by SAD-A, triggering the onset of GSIS from islet β-cells. Consequently, ablation of PAK1 kinase activity or depletion of PAK1 expression completely abolishes the potentiating effect of SAD-A on GSIS. Consistent with its role in regulating GSIS, overexpression of SAD-A in MIN6 islet β-cells significantly stimulated cytoskeletal remodeling, which is required for insulin exocytosis. Together, the present studies identified a critical role of SAD-A in the activation of PAK1 during the onset of insulin exocytosis. PMID:22669945

Synapses of amphids defective (SAD-A) kinase promotes glucose-stimulated insulin secretion through activation of p21-activated kinase (PAK1) in pancreatic β-Cells.

Science.gov (United States)

Nie, Jia; Sun, Chao; Faruque, Omar; Ye, Guangming; Li, Jia; Liang, Qiangrong; Chang, Zhijie; Yang, Wannian; Han, Xiao; Shi, Yuguang

2012-07-27

The p21-activated kinase-1 (PAK1) is implicated in regulation of insulin exocytosis as an effector of Rho GTPases. PAK1 is activated by the onset of glucose-stimulated insulin secretion (GSIS) through phosphorylation of Thr-423, a major activation site by Cdc42 and Rac1. However, the kinase(s) that phosphorylates PAK1 at Thr-423 in islet β-cells remains elusive. The present studies identified SAD-A (synapses of amphids defective), a member of AMP-activated protein kinase-related kinases exclusively expressed in brain and pancreas, as a key regulator of GSIS through activation of PAK1. We show that SAD-A directly binds to PAK1 through its kinase domain. The interaction is mediated by the p21-binding domain (PBD) of PAK1 and requires both kinases in an active conformation. The binding leads to direct phosphorylation of PAK1 at Thr-423 by SAD-A, triggering the onset of GSIS from islet β-cells. Consequently, ablation of PAK1 kinase activity or depletion of PAK1 expression completely abolishes the potentiating effect of SAD-A on GSIS. Consistent with its role in regulating GSIS, overexpression of SAD-A in MIN6 islet β-cells significantly stimulated cytoskeletal remodeling, which is required for insulin exocytosis. Together, the present studies identified a critical role of SAD-A in the activation of PAK1 during the onset of insulin exocytosis.

In-house cyclotron production of high-purity Tc-99m and Tc-99m radiopharmaceuticals.

Science.gov (United States)

Martini, Petra; Boschi, Alessandra; Cicoria, Gianfranco; Zagni, Federico; Corazza, Andrea; Uccelli, Licia; Pasquali, Micòl; Pupillo, Gaia; Marengo, Mario; Loriggiola, Massimo; Skliarova, Hanna; Mou, Liliana; Cisternino, Sara; Carturan, Sara; Melendez-Alafort, Laura; Uzunov, Nikolay M; Bello, Michele; Alvarez, Carlos Rossi; Esposito, Juan; Duatti, Adriano

2018-05-30

In the last years, the technology for producing the important medical radionuclide technetium-99m by cyclotrons has become sufficiently mature to justify its introduction as an alternative source of the starting precursor [ 99m Tc][TcO 4 ] - ubiquitously employed for the production of 99m Tc-radiopharmaceuticals in hospitals. These technologies make use almost exclusively of the nuclear reaction 100 Mo(p,2n) 99m Tc that allows direct production of Tc-99m. In this study, it is conjectured that this alternative production route will not replace the current supply chain based on the distribution of 99 Mo/ 99m Tc generators, but could become a convenient emergency source of Tc-99m only for in-house hospitals equipped with a conventional, low-energy, medical cyclotron. On this ground, an outline of the essential steps that should be implemented for setting up a hospital radiopharmacy aimed at the occasional production of Tc-99m by a small cyclotron is discussed. These include (1) target production, (2) irradiation conditions, (3) separation/purification procedures, (4) terminal sterilization, (5) quality control, and (6) Mo-100 recovery. To address these issues, a comprehensive technology for cyclotron-production of Tc-99m, developed at the Legnaro National Laboratories of the Italian National Institute of Nuclear Physics (LNL-INFN), will be used as a reference example. Copyright © 2018 Elsevier Ltd. All rights reserved.

Sequential hepatobiliary scintigraphy of the patients with constitutional jaundice, ICG excretory defect disease and hepatocellular carcinoma with 99mTc-PI, 99mTc-HIDA and 99mTc-EHIDA

International Nuclear Information System (INIS)

Mitani, Tsuyoshi

1987-01-01

Sequential 2 min scintiphotos were obtained with a scintilation camera after intravenous injection of 3 mCi of 99m Tc-HIDA or 99m Tc-PI. Digital matrix images were simultaneously recorded with computer. Sequential samples for the blood clearance of 99m Tc-HIDA or 99m Tc-PI were obtained for 120 min following injection to the patient of constitutional hyperbilirubinemia and ICG excretory defect disease. In Dubin-Johnson syndrome, the hepatic uptake of 99m Tc-HIDA was faster or normal but the excretion was extremely slower than in normal cases. Both hepatic uptake and excretion of 99m Tc-PI were almost normal. In Rotor's disease, hepatic uptake of 99m Tc-HIDA or 99m Tc-PI was very poor, showing almost no hepatic images in all time. In Gilbert's disease and ICG excretory defect disease, hepatic uptake and excretion of 99m Tc-HIDA or 99m Tc-PI were within normal limit. From these results, Dubin-Johnson syndrome, Rotor's disease and Gilbert's disease show the different patterns between hepatic uptake and excretion of 99m Tc-HIDA and 99m Tc-PI hepatobiliary scintigraphy and these patterns contribute to the differential diagnosis of constitutional jaundice. The usefulness of hepatobiliary imaging with 99m Tc-EHIDA in diagnosis of hepatocellular carcinoma was studied in 15 patients with histologically verified HCC. In 15 patients, 3 patients (20 %) showed increased radioactivity with 99m Tc-EHIDA image, where liver scan with 99m Tc-Sn colloid showed filling defect. These results indicate that use of 99m Tc-EHIDA scan and 67 Ga-citrate imaging is useful for positive visualization of HCC. (author)

Seasonal variations in activity concentrations of 99Tc and 137Cs in the edible meat fraction of crabs and lobsters from the central Irish Sea

International Nuclear Information System (INIS)

Copplestone, D.; Jackson, D.; Hartnoll, R.G.; Johnson, M.S.; McDonald, P.; Wood, N.

2004-01-01

Discharges of most radionuclides into the Irish Sea from the BNFL site at Sellafield have decreased over the past 20 years or so. For a few radionuclides, however, discharges have peaked more recently. Notably, operation of the Enhanced Actinide Removal Plant (EARP) since 1994 has led to an increase in discharges of 99 Tc, as a result of the treatment of previously stored waste, with consequent increases in 99 Tc activity concentrations in a number of marine species, particularly in crustaceans such as lobsters. Previous research has considered the significance of factors such as sex and body weight on radionuclide concentrations. The current project set out to investigate whether seasonal variations in radionuclide concentrations in crabs and lobsters occur, with particular emphasis on the dynamics of 99 Tc and 137 Cs. Organisms were obtained from a site off the Isle of Man, where radionuclide concentrations were measurable but the site was sufficiently distant from Sellafield that the radionuclides were well mixed in the water column and not likely to be influenced by the pulsed nature of discharges of 99 Tc. Crab and lobster samples were collected monthly, between February 2000 and February 2001. Fifteen or 16 individuals (evenly split as male and female) of each species were collected on each occasion. Seawater samples were also collected over the 12-month period. Activity concentrations of 99 Tc in the edible meat fraction (both brown and white meat) ranged from 0.23 to 2.46 Bq kg -1 (fresh weight (fw)) in crabs and 124 to 216 Bq kg -1 (fw) in lobsters, with no observed seasonal variations. Activity concentrations of 137 Cs in both crab and lobster were lower, ranging from -1 for crab meat (fw) and -1 for lobster meat (fw). A statistically significant increase in activity concentrations of 137 Cs in the meat was observed in the summer months for both crab and lobster. The cause has not been investigated but may be related to the laying down of energy reserves

A proposal for spreading and commercializing the (n, gamma) 99Tc generator

International Nuclear Information System (INIS)

Yoshida, Kosuke; Hishinuma, Yukio; Tatenuma, Katsuyoshi

2006-01-01

A practicability of 99m Tc generator based on (n, gamma) method using PZC (Poly Zirconium Compound), a Mo adsorbent with a high adsorption efficiency, has been studied by the FNCA member countries as a part of the FNCA activities; three research collaboration projects, Technetium Generator Project (TCG), Neutron Activation Analysis Project (NAA) and Neutron Spreading Project (NS) have been set up in order to achieve the significant results of the research reactor use among Asian countries. As a result of the collaboration research, practical data on the 99m Tc elution and 99 Mo breakthrough has recently been obtained by using the new 99m Tc generator based on (n, gamma) method using PZC (indicate 'PZC- 99m Tc generator' as follows). Even though unexpected amount of 99 Mo breakthrough accompanied with the 99m Tc elution treatment were currently occurred, the problem has been solved by subsequently adding an alumina column underneath the generator column containing PZC. In accordance with the realization of the practical PZC- 99m Tc generator, an administering tests to the mice with labeled compound of 99m Tc generated by PZC method have already been started by BATAN, a loading machine to simplify the process of the 99 Mo adsorption to PZC and the 99 Mo-PZC packing to a generator column has been fabricated in BATAN's hot cell to realize a mass production of PZC- 99m Tc generator, and moreover the Japanese and Indonesian patents pertaining to the production process and the loading machine of PZC- 99m Tc generator have been applied with joint application of BATAN and KAKEN Co. By the current collaboration approaches mentioned above, it is clear that the Technetium Generator Project of FNCA is now reaching to a phase where the aims of the project shall be turned from establishment of the practical PZC- 99m C generator to establishment of the delivery system of PZC- 99m Tc generator to put them into commercial use. In this paper, a practical application of the PZC- 99m

Therapeutic effect of 99Tc - MDP observed in the treatment of rheumatoid arthritis

International Nuclear Information System (INIS)

Sang Shibiao; Wu Yiwei; Su Chenghai; Zhang Wei; Dong Shenan

2003-01-01

Objective: To evaluate the therapeutic effect and safety of 99 Tc - MDP in the treatment of rheumatoid arthritis (RA). Methods: Two hundred and eight patients with active RA have been treated using 99 Tc - MDP. The clinical manifestation and laboratory examination before and after treatment were observed. Results: The total effective rate of the 99 Tc - MDP was 86.1%. The effectiveness of relieving pain, diminishing swelling, increasing immune function etc was significant. It was most effective in improving morning stiffness, limitation of articulation function and decreasing ESR. Conclusion: The clinical effect of the 99 Tc - MDP is obvious. Application of the 99 Tc - MDP is safety, no significant adverse action and worth clinical using

99mTc-MIBI, 99mTc-tetrofosmin and 99mTc-Q12 in vitro and in vivo

International Nuclear Information System (INIS)

Bernard, Bert F.; Krenning, Eric P.; Breeman, Wout A. P.; Ensing, Geert; Benjamins, Harry; Bakker, Willem H.; Visser, Theo J.; Jong, Marion de

1998-01-01

The aim of this study was to compare uptake of 99m Tc-MIBI, 99m Tc-tetrofosmin and 99m Tc-Q12 in vitro and biodistribution in vivo in rats. In vitro, uptake decreased in the order MIBI→tetrofosmin→Q12. Uptake of MIBI and tetrofosmin, but not of Q12, in cultured tumor cells was dependent on the plasma membrane and mitochondrial potential. In vivo, heart uptake of all three compounds was high and stable. Tumor uptake decreased in the order MIBI→Q12→tetrofosmin and the tumor/blood ratio in the order MIBI→tetrofosmin→Q12

Potential Use Of Activated Carbon To Recover Tc-99 From 200 West Area Groundwater As An Alternative To More Expensive Resins Hanford Site, Richland, Washington

International Nuclear Information System (INIS)

Byrnes, M.E.; Rossi, A.J.; Tortoso, A.C.

2009-01-01

Recent treatability testing performed on groundwater at the 200-ZP-1 Operable Unit at the Hanford Site in Richland, Washington, has shown that Purolite(reg s ign) A530E resin very effectively removes Tc-99 from groundwater. However, this resin is expensive and cannot be regenerated. In an effort to find a less expensive method for removing Tc-99 from the groundwater, a literature search was performed. The results indicated that activated carbon may be used to recover technetium (as pertechnetate, TCO 4 - ) from groundwater. Oak Ridge National Laboratory used activated carbon in both batch adsorption and column leaching studies. The adsorption study concluded that activated carbon absorbs TCO 4 - selectively and effectively over a wide range of pH values and from various dilute electrolyte solutions ( 4 - . Since activated carbon is much less expensive than Purolite A530E resin, it has been determined that a more extensive literature search is warranted to determine if recent studies have reached similar conclusions, and, if so, pilot testing of 200-ZP-1 groundwater wi11 likely be implemented. It is possible that less expensive, activated carbon canisters could be used as pre-filters to remove Tc-99, followed by the use of the more expensive Purolite A530E resin as a polishing step.

Biogeochemical Coupling of Fe and Tc Speciation in Subsurface Sediments: Implications to Long-Term Tc Immobilization

International Nuclear Information System (INIS)

Jim K. Fredrickson; C. I. Steefel; R. K. Kukkadapu; S. M. Heald

2006-01-01

The project has been focused on biochemical processes in subsurface sediments involving Fe that control the valence state, solubility, and effective mobility of 99Tc. Our goal has been to understand the Tc biogeochemistry as it may occur in suboxic and biostimulated subsurface environments. Two objectives have been pursued: (1) To determine the relative reaction rates of 99Tc(VII)O2(aq) with metal reducing bacteria and biogenic Fe(II); and to characterize the identity, structure, and molecular speciation of Tc(IV) products formed through reaction with both biotic and abiotic reductants. (2) To quantify the biogeochemical factors controlling the reaction rate of O2 with Tc(IV)O2?nH2O in sediment resulting from the direct enzymatic reduction of Tc(VII) by DIRB and/or the reaction of Tc(VII) with the various types of biogenic Fe(II) produced by DIRB

Some problems concerning /sup 99m/Tc-sulfur colloid stability in vivo

International Nuclear Information System (INIS)

Komarek, P.; Sup, I.; Krivsky, Z.

1986-01-01

On repeated examination of 60 patients with suspected transplanted kidney rejection using /sup 99m/Tc-sulfur colloid administration the urinary bladder appears on the scintigram in ten cases though no free pertechnetate-/sup 99m/Tc had been chromatographically determined before the administration. Therefore other causes of urine bladder visualization were considered. The fate of the radiocolloid in the body after its administration was studied by measuring the radioactivity of blood and plasma or by chromatographic analysis. A sixfold increase in /sup 99m/Tc activity in comparison with that determined chromatographically in the form of free pertechnetate-/sup 99m/Tc was found in the patients blood 45 min after administration. In normal animal experiments, /sup 99m/Tc was found in the rat blood and urine in the form of pertechnetate. (author)

Negative regulation of TLR4 via targeting of the proinflammatory tumor suppressor PDCD4 by the microRNA miR-21.

LENUS (Irish Health Repository)

Sheedy, FJ

2009-11-29

The tumor suppressor PDCD4 is a proinflammatory protein that promotes activation of the transcription factor NF-kappaB and suppresses interleukin 10 (IL-10). Here we found that mice deficient in PDCD4 were protected from lipopolysaccharide (LPS)-induced death. The induction of NF-kappaB and IL-6 by LPS required PDCD4, whereas LPS enhanced IL-10 induction in cells lacking PDCD4. Treatment of human peripheral blood mononuclear cells with LPS resulted in lower PDCD4 expression, which was due to induction of the microRNA miR-21 via the adaptor MyD88 and NF-kappaB. Transfection of cells with a miR-21 precursor blocked NF-kappaB activity and promoted IL-10 production in response to LPS, whereas transfection with antisense oligonucleotides to miR-21 or targeted protection of the miR-21 site in Pdcd4 mRNA had the opposite effect. Thus, miR-21 regulates PDCD4 expression after LPS stimulation.

Redox behavior of Tc(VII)/Tc(IV) under various reducing conditions in 0.1 M NaCl solutions

International Nuclear Information System (INIS)

Kobayashi, T.; Gaona, X.; Altmaier, M.; Scheinost, A.C.; Fellhauer, D.; European Commission Joint Research Centre, Karlsruhe

2013-01-01

Redox behaviour of Tc(VII)/Tc(IV) was investigated in 0.1 M NaCl solutions containing different reducing agents in the pH range 2 to 13 at 22 C under inert Ar atmosphere. In several samples, the 1 x 10 -5 mol/dm 3 (M) initially added TcO 4 - was reduced to form a Tc(IV) oxide solid phase with low solubility. The observed Tc redox transformation processes are systematized according to E h -pH conditions in solution, indicating that a borderline for the reduction of Tc(VII) to Tc(IV), TcO 4 - + 3e - + 4H + TcO 2 . xH 2 O(coll, hyd) + (2-x)H 2 O exists, independent of the reducing chemical system. This experimentally derived borderline is about 100 mV lower than the equilibrium line calculated from the reported standard redox potential of TcO 2 . 1.6H 2 O(s). This behaviour can be related to the existence of more soluble solid phase modifications, i.e. nanoparticulate Tc(IV) oxide species TcO 2 . xH 2 O(coll, hyd). The reaction kinetics likewise correlate to the redox potential measured in solution. Slow reduction of Tc(VII) to Tc(IV) was observed when the redox potential in the system was slightly below the above mentioned reduction borderline. Fast reduction was observed in the systems far below the borderline, but also in those systems containing Fe(II) solids, suggesting a specific surface mediated effect in the reduction process. EXAFS analysis on two magnetite samples indicate reduced Tc(IV) species which do not remain adsorbed at the reactive mineral surface and are incorporated in the magnetite structure. (orig.)

Radioimmunoscintigraphy of experimental internal carotid arterial thrombi in dogs with 99mTc-labelled monoclonal anti-activated platelet antibody SZ-51

International Nuclear Information System (INIS)

Bao Shiyao; Li Wen; He Guangren; Shao Guofu; Zhang Zhilin; Wu Jinchang

1995-05-01

The capacity of McAbSZ-51, which is specific for an α-granule membrane protein (GMP-140) expressed on the surface of activated platelets, to bind to the grafted human thrombus in rabbits was studied. The feasibility of imaging thrombus with 99m Tc-labelled McAbSZ-51 in the internal carotid artery of dog was also explored. The results showed that McAbSZ-51 could bind to the grafted human thrombus in rabbits. The thrombus in internal carotid artery was clearly discerned at 2 to 6 h after injection of 99m Tc-SZ-51, with the optimal imaging time at 2 to 4 h after injection. The radioactivity ratio of thrombus to blood was 6.03 +- 1.09 at 6 to 8 h after injection. It is thus concluded that by using the 99m Tc-labelled McAbSZ-51, the early and specific detection of thrombi formed in vivo was fairly possible and feasible. (3 figs., 1 tab.)

Chemical aspects of labeling sucralfate with /sup 99m/TcO/sub 4/

Energy Technology Data Exchange (ETDEWEB)

Billinghurst, M.W.; Abrams, D.N.; Lawson, M.S.

1989-04-01

Two formulations of (/sup 99m/Tc)sucralfate have been used to image gastric and duodenal ulcers and inflammatory bowel disease. One formulation is a complexation of (/sup 99m/Tc)HSA with sucralfate. The second is prepared by directly labeling sucralfate with (/sup 99m/Tc)pertechnetate in the presence of stannous ion. An in vitro study of the factors affecting the production and stability of these labeled sucralfate preparations was conducted. Both formulations were stable at the acidic pH likely encountered in the stomach. However, at pH greater than 6 the albumin-sucralfate complex began to dissociate while directly labeled sucralfate was stable to a pH of 9. Conversely it was shown that directly labeled sucralfate was more susceptible to loss of /sup 99m/Tc to other chelating species. Sucralfate complexed with (/sup 99m/Tc)HSA was radiochemically stable up to a specific activity of 26 GBq (700 mCi) per gram while directly labeled sucralfate showed decreased 24-hr stability at specific activities greater than 837 mCi (31 GBq) per gram.

Preparation of 99mTc-thiourea complex as a precursor for Tc(III) labeled compounds

International Nuclear Information System (INIS)

Rey, A.; Teran, M.; Molina, S.; Leon, A.; Kremer, C.; Gambino, D.; Kremer, E.

1996-01-01

Ligand exchange is one of the possible synthetic routes to obtain 99m Tc coordination compounds. However, the success of this route depends on the availability of good precursors. The objective of this work is the preparation of the complex [ 99m Tc (tu) 6 ] 3+ (tu = thiourea), as a potential precursor for 99m Tc(III) coordination compounds. The preparation was successfully performed in acidic conditions, the excess of tu serving as reducing agent. At pH values higher than 3, the compound becomes unstable and on addition of polydentate ligands new Tc(III) complexes are formed. With edta, the complex 99m Tc(III)-edta was obtained in high yield. (author). 13 refs., 3 tabs

Planar scintigraphy with 123I/99mTc-sestamibi, 99mTc-sestamibi SPECT/CT, 11C-methionine PET/CT, or selective venous sampling before reoperation of primary hyperparathyroidism?

Science.gov (United States)

Schalin-Jäntti, Camilla; Ryhänen, Eeva; Heiskanen, Ilkka; Seppänen, Marko; Arola, Johanna; Schildt, Jukka; Väisänen, Mika; Nelimarkka, Lassi; Lisinen, Irina; Aalto, Ville; Nuutila, Pirjo; Välimäki, Matti J

2013-05-01

All patients with primary hyperparathyroidism should undergo localization studies before reoperation, but it is not known which method is most accurate. The purpose of this prospective study was to compare the performance of planar scintigraphy with (123)I/(99m)Tc-sestamibi, (99m)Tc-sestamibi SPECT (SPECT/CT), (11)C-methionine PET/CT, and selective venous sampling (SVS) in persistent primary hyperparathyroidism. Twenty-one patients referred for reoperation of persistent hyperparathyroidism were included and investigated with (123)I/(99m)Tc-sestamibi, SPECT/CT (n = 19), (11)C-methionine PET/CT, and SVS (n = 18) before reoperation. All patients had been operated on 1-2 times previously because of hyperparathyroidism. The results of the localization studies were compared with operative findings, histology, and biochemical cure. Eighteen (86%) of 21 patients were biochemically cured. Nineteen parathyroid glands (9 adenomas, 1 atypical adenoma, and 9 hyperplastic glands) were removed from 17 patients, and 1 patient who was biochemically cured had an unclear histology result. The accuracy for localizing a pathologic parathyroid gland to the correct side of the neck was 59% (95% confidence interval [CI], 36%-79%) for (123)I/(99m)Tc-sestamibi, 19% (95% CI, 5%-42%) for SPECT/CT, 65% (95% CI, 43%-84%) for (11)C-methionine PET/CT, and 40% (95% CI, 19%-65%) for SVS (P hyperparathyroidism and is recommended as first-line imaging before reoperation. (11)C-methionine PET/CT provides valuable additional information if (123)I/(99m)Tc-sestamibi scan results remain negative. (99m)Tc-sestamibi SPECT/CT and SVS provide no additional information, compared with the combined results of (123)I/(99m)Tc-sestamibi and (11)C-methionine PET/CT imaging.

Use of 99mTc-Mononuclear Leukocyte Scintigraphy in Nosocomial Fever

International Nuclear Information System (INIS)

Gutfilen, B.; Lopes de Souza, S.A.; Martins, F.P.P.; Cardoso, L.R.; Pinheiro Pessoa, M.C.; Fonseca, L.M.B.

2006-01-01

Purpose: To determine the overall diagnostic accuracy of mononuclear leukocyte- 99m Tc scintigraphy in the routine detection of infectious lesions and fever of unknown origin (FUO) in inpatients. Material and Methods: The use of mononuclear leukocyte 99m Tc scintigraphy is presented in 87 patients who fulfilled the Durack and Street diagnostic criteria of nosocomial FUO; 66 patients were suspected of having infectious lesions (myocarditis, endocarditis, infected catheters, diabetic foot, and osteomyelitis) and 21 patients presented with unknown causes of FUO. Scans were carried out 1, 3, and 24 h after injection of labeled leukocytes. Results: In three cases (3/27) where scintigraphs were negative, biopsies were positive. There were two (2/87) false-positive scintigrams. We found a 95.8% sensitivity and 92.3% specificity. PPV was 93.8%, PPN 94.7%, and accuracy 94.2%. Conclusion: Mononuclear leukocyte 99m Tc scintigraphy showed high sensitivity, specificity, positive and negative predictive values in patients with nosocomial FUO. These results suggest an important role for nuclear medicine in the management of patients with infection/inflammation

Impurities in Tc-99m radiopharmaceutical solution obtained from Mo-100 in cyclotron.

Science.gov (United States)

Tymiński, Zbigniew; Saganowski, Paweł; Kołakowska, Ewa; Listkowska, Anna; Ziemek, Tomasz; Cacko, Daniel; Dziel, Tomasz

2018-04-01

The gamma emitting impurities in 99m Tc solution obtained from enriched molybdenum 100 Mo metallic target after its irradiation in a cyclotron were measured using a high-purity germanium (HPGe) detector. The radioactivity range of tested samples of 99m Tc was rather low, in the range from 0.34 to 2.39 MBq, thus creating a challenge to investigate the standard measurement HPGe system for impurity detection and quantification. In the process of 99m Tc separation from irradiated target the AnaLig® Tc-02 resin, Dionex H + and Alumina A columns were used. Fractions of eluates from various steps of separation process were taken and measured for radionuclidic purity. The overall measurement sensitivity of gamma emitters in terms of minimum detectable activity (MDA) was found at the level of 14-70Bq with emission lines in range of 36 - 1836keV resulting in impurity content range of 6.7 × 10 -4 to 3.4 × 10 -3 % for 93 Tc, 93m Tc, 94 Tc, 94m Tc, 95 Tc, 95m Tc, 96 Tc 96 Nb, 97 Nb, 99 Mo contaminants and 9.4 × 10 -3 % for 97m Tc. The usefulness of the chosen measurement conditions and the method applied to testing the potential contaminators was proved by reaching satisfactory results of MDAs less than the criteria of impurity concentration of all nuclides specified in the European Pharmacopoeia. Copyright © 2017 Elsevier Ltd. All rights reserved.

High-Tc superconductor applications

International Nuclear Information System (INIS)

Anon.

1988-01-01

There has been much speculation about new products and business opportunities which high-Tc superconductors might make possible. However, with the exception of one Japanese survey, there have not been any recognized forecasts suggesting a timeframe and relative economic impact for proposed high-Tc products. The purpose of this survey is to provide definitive projections of the timetable for high-Tc product development, based on the combined forecasts of the leading U.S. superconductivity experts. The FTS panel of experts on high-Tc superconductor applications, representing both business and research, forecast the commercialization and economic impact for 28 classes of electronic, magnetic, communications, instrumentation, transportation, industrial, and power generation products. In most cases, forecasts predict the occurrence of developments within a 90% statistical confidence limit of 2-to-3 years. The report provides background information on the 28 application areas, as well as other information useful for strategic planners. The panel also forecast high-Tc research spending, markets, and international competitiveness, and provide insight into how the industry will evolve

Phyto extraction of 99Tc on soil cores with aged contamination

International Nuclear Information System (INIS)

Massoura, S.T.; Echevarria, G.; Morel, J.L.; Massoura, S.T.; Leclerc-Cessac, E.; Denys, D.

2004-01-01

99 Tc is an artificial radionuclide which is found in high-activity and long-lived nuclear waste. This work was designed to study the phyto-extraction of 99 Tc in soils that had received aged contamination and to monitor the resulting 99 Tc concentrations in the soil solution of undisturbed soil cores in a greenhouse. Undisturbed soil cores had been sampled previously from a Rendzic Leptosol (R), a Fluvic cambisol (F) and a Dystric cambisol (D), using 0.5-m diameter PVC tubing (3 samples/soil type) without disturbing soil structure (1). Each core was equipped with two nylon porous cups (respectively 20 and 35 cm deep) and a final leachate collector. A 99 TcNO 3 solution had been supplied at the soil surface of each core during the two previous years (4200 kBq in total) in which maize and wheat had been successively cropped. These two crops had already removed 30-65% of total contamination before the present study. After the second year no more 99 Tc was added to the cores. Thereafter, Lolium perenne was cultivated for 20 successive months. 99 Tc was determined in both plant aerial parts and water samples (from both cups and collectors), and the balance of 99 Tc in the system was established after phyto-extraction. Results showed that transfer of 99 Tc to plants vary among soils: 7% on soil R to 11% on soil D. Concentration of 99 Tc in the porous cups dramatically decreased in all soils. The plants maintained low and stable concentration levels of 99 Tc in the soil solution which decreased the potential migration of the radionuclide through the cores: The leaching of 99 Tc in the final collectors of the R soil cores decreased from 18 to 1.7 Bq mL -1 . (author)

Estimation of the Arterial Fraction of Total Hepatic Flow from Radionuclide Angiogram Using 99mTc-DISIDA

International Nuclear Information System (INIS)

Lee, Hae Gin; Lim, Gye Yeon; Yang, Il Kwon; Kim, Hack Hee; Lim, Jung Ik; Bahk, Yong Whee; Han, Sok Won; Han, Nam Ik; Lee, Young Sok

1991-01-01

Arterial fraction of total hepatic blood flow was estimated by a new method, slope method, on radionuclide angiogram using 99m Tc-DISIDA and was compared with that from 99m Tc-Phytate radionuclide angiogram. This study included 11 of normal subjects, 37 of intermediate group with various liver diseases, and 25 patients with liver cirrhosis. We analyzed the data with slope method from radionuclide angiograms and the results were compared with hepatic arterial fractions from uptake method, introduced by Lee et al. at 1986. The hepatic arterial fractions from radionuclide angiograms using 99m Tc-DISIDA and 99m Tc- Phytate were 0.32 ± 0.09 and 0.31 ± 0.11 respectively in normal subjects, and 0.75 ± 0.18 and 0.77 ± 0.21 respectively in patients with liver cirrhosis. The hepatic arterial fractions by the slope method was well correlated with those of the uptake method on 99m Tc-DISIDA scan. There was high correlation between the hepatic arterial fractions from 99m Tc-DISIDA and 99m Tc-Phytate scans. Hepatic arterial fraction estimated by the slope method is a useful index for the diagnosis of liver cirrhosis and the evaluation of status of portal hypertension.

Clinical application of 99mTc-HMPAO labeled leucocytes imaging in detecting bone joint infection

International Nuclear Information System (INIS)

Li Biao; Barthe, N.; Basse-Cathalinat, B.

1995-01-01

99m Tc-MDP scintigraphy and 99m Tc-HMPAO-leucocytes imaging were performed in twenty five patients with clinically suspected bone joint infection. All of the 25 cases were confirmed by surgery, microbiological and histologic examinations. Among them 21 cases were definitively diagnosed as infections, while 3 cases were non-infection. The results of 99m Tc-MDP scintigraphy showed that all of 25 cases demonstrated anomalous accumulation of radioactivity in the clinically suspected infections sites, while in 99m Tc-HMPAO-leucocytes imaging, concentrated radioactivity in proved infectious sites was observed in 19 cases, non-anomalous radioactivity found in 4 cases of non-infectious sites, but there were 2 cases false negative with long term antibiotics treatment, none of the case was false positive. Thereby a sensitivity of the labelled leucocytes imaging of 90.5%, a specificity of 100%, and a accuracy of about 92% were found. Present research work concluded that 99m Tc-HMPAO labelled leucocytes imaging provided a non-invasive, effective, and reliable diagnostic method in detecting patients with clinically suspected bone joint infection and afforded strong evidence for effective therapy

Significance of renal scintigraphy with 99mTc-DTPA for the diagnosis of diabetic nephropathy

International Nuclear Information System (INIS)

Lin Jun; Zhao Shuhao; Guo Rong; Lin Haoxue; Xie Zhichun

1995-01-01

99m Tc-DTPA renography was performed in 64 cases of type II diabetes mellitus and 20 control subjects. The value of GFR in the controls was 113 +-11.7 ml/min. The value of GFR in 15 of 43 patients with negative proteinuria was more than 140 ml/min, but GFR in the 21 diabetes with positive proteinuria was 76 +- 32.9 ml/min. These data indicated that 99m Tc-DTPA renography is an accurate and sensitive method for evaluation of hyperfiltration in early diabetes mellitus

Emission of Tc-99 from nuclear facilities

International Nuclear Information System (INIS)

Luxenburger, H.J.; Schuettelkopf, H.; Bohn, B.

1984-11-01

No noticeable Tc-activities are emitted from nuclear power stations. The emissions with the gaseous effluents exceed but rarely the detection limit of 25 nCi/h. Likewise, the emission with the liquid effluents remains below the detection limit of about 0.5 nCi/m 3 . Neither can a remarkable emission be recorded from the facilities of the Central Decontamination Services Department (HDB) of KfK. The emissions from the evaporation system for low level solutions and from the evaporation system for low level solutions and from the incineration facility for solid wastes do not exceed or rarely exceed to a minor extent the detection limit of 0.3 pCi/m 3 waste air. Also with the liquid effluents only minor Tc-amounts are discharged of 0.3 nCi/m 3 at the maximum. In the distillate of the medium level solutions discharged from the Karlsruhe Reprocessing Plant (WAK) to HDB as so-called tritiated water 2 nCi/m 3 Tc-99 at the maximum are contained. Only in the gaseous effluents from the evaporation system for medium level solutions emissions of up to 14 pCi/m 3 can be detected. The detection limits are almost permanently exceeded by the gaseous effluents from WAK. Small amounts of Tc-99 of 7 pCi/m 3 exhaust air at the maximum are released to the environment. However, the amount of Tc accumulated over the sampling period is insignificant from the radioecological point of view. (orig./HP) [de

Comparisons of 131I, 201Tl and 99mTc activity measurements in activimeters

International Nuclear Information System (INIS)

Oropesa Verdecia, Pilar; Hernandez Rivero, Aerulio T.; Serra Aguila, Rolando A.; Martinez Herrera, Ernesto; Varela Corona, Consuelo

2003-01-01

The correct administration to a patient of the a priori established activity of the radiopharmaceutical is an important factor to ensure the confidence in the diagnosis or the therapy efficiency, keeping at the same time the human exposure as low as possible. National comparisons for the 131I, 201Tl and 99mTc activity measurements in activimeters have been organized for the first time with the aim of obtaining information about the quality of the administration of radiopharmaceuticals. In the comparison run participated ten Cuban Nuclear Medicine Departments and the laboratories involved in the production of that kind of compounds. The comparison results, shown in this paper, have facilitated the identification of the problems and to initiate preventive actions. Furthermore, these results reflect the need of establishing Quality Systems in Nuclear Medicine in Cuba

Up-regulation of K{sub ir}2.1 by ER stress facilitates cell death of brain capillary endothelial cells

Energy Technology Data Exchange (ETDEWEB)

Kito, Hiroaki [Department of Molecular and Cellular Pharmacology, Graduate School of Pharmaceutical Sciences, Nagoya City University, Nagoya (Japan); Yamazaki, Daiju [Department of Molecular and Cellular Pharmacology, Graduate School of Pharmaceutical Sciences, Nagoya City University, Nagoya (Japan); Department of Biological Chemistry, Kyoto University, Graduate School of Pharmaceutical Sciences, Kyoto (Japan); Department of Molecular Neurobiology, Graduate School of Medical Sciences, Nagoya City University, Nagoya (Japan); Ohya, Susumu; Yamamura, Hisao [Department of Molecular and Cellular Pharmacology, Graduate School of Pharmaceutical Sciences, Nagoya City University, Nagoya (Japan); Asai, Kiyofumi [Department of Molecular Neurobiology, Graduate School of Medical Sciences, Nagoya City University, Nagoya (Japan); Imaizumi, Yuji, E-mail: yimaizum@phar.nagoya-cu.ac.jp [Department of Molecular and Cellular Pharmacology, Graduate School of Pharmaceutical Sciences, Nagoya City University, Nagoya (Japan)

2011-07-29

Highlights: {yields} We found that application of endoplasmic reticulum (ER) stress with tunicamycin to brain capillary endothelial cells (BCECs) induced cell death. {yields} The ER stress facilitated the expression of inward rectifier K{sup +} channel (K{sub ir}2.1) and induced sustained membrane hyperpolarization. {yields} The membrane hyperpolarization induced sustained Ca{sup 2+} entry through voltage-independent nonspecific cation channels and consequently facilitated cell death. {yields} The K{sub ir}2.1 up-regulation by ER stress is, at least in part, responsible for cell death of BCECs under pathological conditions. -- Abstract: Brain capillary endothelial cells (BCECs) form blood brain barrier (BBB) to maintain brain homeostasis. Cell turnover of BCECs by the balance of cell proliferation and cell death is critical for maintaining the integrity of BBB. Here we found that stimuli with tunicamycin, endoplasmic reticulum (ER) stress inducer, up-regulated inward rectifier K{sup +} channel (K{sub ir}2.1) and facilitated cell death in t-BBEC117, a cell line derived from bovine BCECs. The activation of K{sub ir} channels contributed to the establishment of deeply negative resting membrane potential in t-BBEC117. The deep resting membrane potential increased the resting intracellular Ca{sup 2+} concentration due to Ca{sup 2+} influx through non-selective cation channels and thereby partly but significantly regulated cell death in t-BBEC117. The present results suggest that the up-regulation of K{sub ir}2.1 is, at least in part, responsible for cell death/cell turnover of BCECs induced by a variety of cellular stresses, particularly ER stress, under pathological conditions.

99mTc-ciprofloxacin imaging in infectious and sterile inflammation in rat model

International Nuclear Information System (INIS)

Shin, Jung Woo; Ryu, Jin Sook; Oh, Seung Jun; Choen, Jun Hong; Moon, Dae Hyuk; Lee, Hee Kyung

1999-01-01

99m Tc-Ciprofloxacin is a potentially specific agent for bacterial infection. The aim of this study was to find out whether 99m Tc-Ciprofloxacin accumulation can differentiate bacterial infectious inflammation from nonbacterial sterile inflammation. 99m Tc-Ciprofloxacin was synthesized with 99m Tc 20 mCi, ciprofloxacine 2 mg, formamidine sulphinic acid 1 mg, and 15 sec heating in microwave. For induction of infectious or sterile inflammation in SD rats, 2 x 10 8 of S. aureus in 0.2ml (group1, n=9) or 0.2 ml of terpentine oil (group 2, n=10) were injected to thigh muscle. Three days later, 99m Tc-Ciprofloxacin images were obtained at 4 hrs after iv injection of 37MBq of 99m Tc-Ciprofloxacin. Immediately after imaging, rats were sacrificed and dissected to obtain %ID/g of normal organs and inflammatory lesions. For histopathologic evaluation, tissue specimens from the inflammatory lesions were obtained. The induction of infection/inflammation produced marked swelling of thighs in both groups. 99m Tc-Ciprofloxacin imaging of both groups showed increased uptake, but target to background uptake ratio in group 1 was significantly higher than group 2 (3.70±0.5 vs 2.18±0.3, p 99m Tc-Ciprofloxacin in liver, slpeen, kidney were 6.1±0.45, 5.1±0.42, 3.42±0.2%ID/g, respectively, and inflammatory lesion in group 1 and group 2 were 0.42±0.09 and 0.24±0.02%ID/g, respectively. Both lesion to normal muscle activity ratio and lesion to blood activity ratio of 99m Tc-Ciprofloxacin in group 1 were significantly higher than group 2 (5.29±2.3 vs 1.69±0.2, 1.45±0.47 vs 0.93±0.2, p 99m Tc-Ciprofloxacin uptake is significantly higher in bacterial infectious inflammation than sterile inflammation. However, further studies and cautious clinical application are needed for differentiating infectious from sterile inflammation using 99m Tc-Ciprofloxacin imaging, because there is still significant degree of 99m Tc-Ciprofloxacin accumulation in sterile inflammation

Structure-activity studies on 99mTc phenolic aminocarboxyllic acid hepatobiliary agente

International Nuclear Information System (INIS)

Maddalena, D.J.; Wilson, J.G.; Snowdon, G.M.

1987-01-01

Biodistributions of a series of eight 99m Tc hydroxybenzylsarcosine (HBS) complexes were carried out in rats and their urinary and hepatobiliary excretion compared with their lipophilicities, the influence of substituent on the phenyl ring and plasma protein binding ability. The charge on the complexes was determined by electrophoresis at varying pH values. The HBS derivatives formed anionic complexes with 99m Tc that excreted mainly via the urinary route. An increase in the lipophilicity of the complexes by substitution of halogens onto the phenyl ring led to an increase in serum protein binding and a decrease in the urinary output but hat no direct effect on hepatobiliary output. (Author) [es

Soil-to-Rice Transfer of {sup 99}Tc in Paddy Soils Contaminated in Two Different Ways

Energy Technology Data Exchange (ETDEWEB)

Choi, Yongho; Lim, Kwangmuk; Jun, In; Kim, Byungho; Keum, Dongkwon [Korea Atomic Energy Research Institute, Daejeon (Korea, Republic of)

2014-05-15

Rice is one of the most important food crops in the world. All isotopes of technetium (Tc) are radioactive, and the environmentally most important one is {sup 99}Tc because of its very long half-life (2.1x10{sup 5} years) and relatively high {sup 235}U-fission yield. Accordingly, it is one of the critical radionuclides in an environmental impact assessment for radioactive waste disposal. A significant amount of {sup 99}Tc can be released into the atmosphere in a severe reactor accident as was shown in the Chernobyl accident. It is a pure better emitter and thus internal exposure via food consumption may be a primary contributor to the {sup 99}Tc radiation dose to humans. Paddy rice fields can be contaminated with {sup 99}Tc in various ways. In the present study, greenhouse experiments were conducted to investigate the transfer of {sup 99}Tc from four paddy soils contaminated in two different ways. One was to simulate plowing the topsoil after a pre-transplanting deposition of {sup 99}Tc, whereas the other was to simulate a {sup 99}Tc deposition onto the surface water shortly after transplanting. Soil-to-rice transfer of {sup 99}Tc in paddy soils was experimentally investigated for two different scenarios of the paddy-field contamination. It was demonstrated that a post-transplanting deposition of {sup 99}Tc onto the surface water can lead to a much higher transfer than a pre-transplanting deposition followed by plowing. The surface-water concentrations of {sup 99}Tc following the post-transplanting deposition was markedly higher than those following the pre-transplanting deposition, possibly indicating a much higher plant-base uptake of {sup 99}Tc following the post-transplanting deposition. The present results can be referred to in a radiological impact assessment for the contamination of paddy fields with {sup 99}Tc by chronic or acute releases from nuclear facilities.

Milking technique of sup(99m)Tc generators and labeling efficiencies

International Nuclear Information System (INIS)

Salehi, N.; Guignard, P.A.

1985-01-01

Increased levels of 99 Tc in generator produced sup(99m)Tc have an adverse effect on the labelling efficiency of red blood cells and human serum albumin. A two-step milking technique in which the first 1-2 ml of eluate is discarded has been found to produce higher and more constant labelling efficiency of lymphocytes and platelets than a one-step procedure. Binding efficiency of platelet-rich plasma and lymphocytes with sup(99m)Tc is greater in the two-step technique. High activity concentration in the eluate for critical labelling is between 1.5-3 ml. (U.K.)

Clinical usefulness of 99mTc-EDDA/HYNIC-TOC scintigraphy in oncological diagnostics: a pilot study.

Science.gov (United States)

Plachcinska, Anna; Mikolajczak, Renata; Maecke, Helmut; Mlodkowska, Ewa; Kunert-Radek, Jolanta; Michalski, Andrzej; Rzeszutek, Katarzyna; Kozak, Jozek; Kusmierek, Jacek

2004-04-01

The clinical usefulness of a new 99mTc-labeled somatostatin analogue has been studied from the standpoint of oncological diagnostics. The group of patients studied included 40 individuals with diagnosed malignant neoplasms (32 primary and 8 metastatic). Among the primary tumors were 7 pituitary adenomas (5 hormonally active and 2 inactive), 1 liposarcoma, 2 carcinoids, 1 breast carcinoma, and 21 cases of lung cancer (2 small cell and 19 non-small cell) were represented. The metastatic tumors consisted of: 3 malignant melanomas, 1 pheochromocytoma, 1 prostatic cancer, 1 leiomyosarcoma, 1 pancreatic carcinoma ectopically secreting ACTH, and 1 carcinoid of the thymus. The radiopharmaceutical, 99mTc-EDDA/HYNIC-octreotide, was i.v. administered at the activity of 740-925 MBq. The imaging was comprized of a whole-body scan and single photon emission computed tomography. Positive scintigrams were obtained in 4 of 5 hormonally active pituitary adenomas, in 1 of 2 cases of carcinoid, in liposarcoma, breast cancer, and all cases of small cell (SCLC) and non-small cell lung cancer (NSCLC). The neoplastic metastases were visualized in 2 of 3 cases of melanoma and in patients with pheochromocytoma, pancreatic carcinoma secreting ACTH, and thymic carcinoid. Scintigrams were negative in both hormonally inactive pituitary adenomas, in one case of metastatic malignant melanoma, leiomyosarcoma, and in cases of metastasis from the prostatic carcinomas. The results of this pilot study indicated that 99mTc-EDDA/HYNIC-TOC is a potentially useful radiopharmaceutical for the imaging of a wide range of primary and metastatic tumors. More detailed indications for the clinical usefulness of the new tracer for the imaging of selected tumor types require studies on much larger groups of patients. Special attention should be paid to the successful imaging of all cases of NSCLC.

99mTc-Dextran-70: preparation and quality control

International Nuclear Information System (INIS)

Herrerias, Rosana; Muramoto, Emiko; Hamada, Elena S.; Barboza, Marycel F. de; Silva, Constancia P.G. da

1997-01-01

Dextran-70 labelled with 99m Tc is used for lymphocintigraphy in Nuclear Medicine. The aims of this work were: the lyophilized kit formulation; the radiochemical quality control determination and the biodistribution studies in Wistar rats. Each lyophilized vial contains: 50 mg Dextran-70 (Sigma); 750 μg Sn Cl 2 . 2 H 2 O, pH = 4.0. For the radiochemical determination the following parameters were assayed: Chromatography systems (Whatman 3MM, TLC-SG (Silica-gel) e TLC-A1 (aluminium); the 99m Tc activities (37, 111 and 1850 MBq); the 99m Tc volumes (1,3,5 and 8 mL) and the stability after the lyophilization process (1, 3, 6, 12 and 24 months). The Whatman 3MM chromatography system using acetone as solvent presented a purity yield of 99.88; 99.70; 99.00 and 98.92% using 1, 3, 5 and 8 mL of 99m Tc, respectively. The yield of labelling showed 99.80 % of radiochemical purity using 1850 MBq of 99m Tc, after 24 months. The biological studies were performed in Wistar rats, average weight 250g, after intravenous administration of 99m Tc-Dextran-70 (2.96 MBq). A slow blood decrease with high hepatic uptake was mesured. The high kidney uptake observed, during the experiment, was due the experiment, was due the fact that the animals were kept under anaesthesic effect. (author). 4 refs., 2 figs., 4 tabs

Scintigraphy with 99mTc labelled polyclonal human IgG in rheumatoid arthritis patients

International Nuclear Information System (INIS)

Stanchev, V.; Batalov, A.; Atanasov, A.

1999-01-01

The study design to assess the diagnostic relevance of scintigraphy with 99m Tc labelled polyclonal human IgG (HIG) for detecting active synovitis in rheumatoid arthritis patients. Fifteen patients presenting rheumatoid arthritis and 3 healthy volunteers are studied on digital camera (Diacam, Siemens). Following iv injection of 500 MBq 99m Tc - HIG, a 3- phase scintigraphy of the knee joints is performed and 4 hours later multiple planar views of the peripheral joint are recorded. Scintigraphic data are comparatively studied with the clinical indicators pointing to active synovitis - joint swellings and pain. Markedly expressed 99m Tc - HIG uptake is noted in joints apparently the most actively involved in the arthritis process clinically, whereas most of the joints without evidence of active synovitis revealed background activity only. The obtained scintigraphic results correlate strongly with the clinical indicator joint swelling (93.2%), and somewhat less with the presence of pain (81.5%). 13.5 per cent of the joints without clinically detectable swelling and 25.6% those free of pain are HIG-positive. 99m Tc - HIG scintigraphy is a highly sensitive noninvasive method of detecting active synovitis, promoting objective assessment of the joint inflammatory process in the course of treatment and follow-up study of rheumatoid arthritis patients

Clinical application of 99mTc-DTPA-HSA

International Nuclear Information System (INIS)

Kawamura, Yasuaki; Yamazaki, Junichi; Okuzumi, Ichio

1989-01-01

A newly developed blood pool imaging agent, Tc-99m DTPA-HSA (Tc-99m HSA-D), was clinically assessed in blood pool studies of patients with heart disease. Twenty mCi of Tc-99m HSA-D was iv injected to the patients. Similarly, conventional Tc-99m HSA was injected one week later for comparison. Blood counts of Tc-99m HSA-D were significantly higher than those of Tc-99m HSA at 30 minutes after iv injection (p<0.01) and at one, 3, and 6 hours (p<0.001). For the heart, liver, and lungs, sequential counts of Tc-99m HSA-D were also significantly higher than those of Tc-99m HSA. Free Tc-99m uptake in the stomach, thyroid gland, and kidneys was higher on Tc-99m HSA images than Tc-99m HSA-D images. Hepatic and pulmonary uptake of free Tc-99m that were visualized on Tc-99m HSA-D did not influence the diagnostic ability. None of the patients had clinical toxicity of Tc-99m HSA-D. The results indicate that Tc-99m HSA-D is a stable blood pool imaging agent. (Namekawa, K)

Reconstitution of CO2 Regulation of SLAC1 Anion Channel and Function of CO2-Permeable PIP2;1 Aquaporin as CARBONIC ANHYDRASE4 Interactor

Science.gov (United States)

Zeise, Brian; Xu, Danyun; Rappel, Wouter-Jan; Boron, Walter F.; Schroeder, Julian I.

2016-01-01

Dark respiration causes an increase in leaf CO2 concentration (Ci), and the continuing increases in atmospheric [CO2] further increases Ci. Elevated leaf CO2 concentration causes stomatal pores to close. Here, we demonstrate that high intracellular CO2/HCO3− enhances currents mediated by the Arabidopsis thaliana guard cell S-type anion channel SLAC1 upon coexpression of any one of the Arabidopsis protein kinases OST1, CPK6, or CPK23 in Xenopus laevis oocytes. Split-ubiquitin screening identified the PIP2;1 aquaporin as an interactor of the βCA4 carbonic anhydrase, which was confirmed in split luciferase, bimolecular fluorescence complementation, and coimmunoprecipitation experiments. PIP2;1 exhibited CO2 permeability. Mutation of PIP2;1 in planta alone was insufficient to impair CO2- and abscisic acid-induced stomatal closing, likely due to redundancy. Interestingly, coexpression of βCA4 and PIP2;1 with OST1-SLAC1 or CPK6/23-SLAC1 in oocytes enabled extracellular CO2 enhancement of SLAC1 anion channel activity. An inactive PIP2;1 point mutation was identified that abrogated water and CO2 permeability and extracellular CO2 regulation of SLAC1 activity. These findings identify the CO2-permeable PIP2;1 as key interactor of βCA4 and demonstrate functional reconstitution of extracellular CO2 signaling to ion channel regulation upon coexpression of PIP2;1, βCA4, SLAC1, and protein kinases. These data further implicate SLAC1 as a bicarbonate-responsive protein contributing to CO2 regulation of S-type anion channels. PMID:26764375

Assessment of hepatocyte and kupffer cell function using Tc-99m DISIDA/Tc-99m tin colloid in thioacetamide-induced liver injury

International Nuclear Information System (INIS)

Ahn, B. C.; Chun, K. A.; Lee, J.; Lee, K. B.

1997-01-01

Toxic liver injury is not unusual in clinical field and liver biopsy is one of the most accurate method to define the severity of liver injury. But occasionally, it is impossible to obtain liver tissue in patients with acute toxic liver injury. The aim of this study is to evaluate the possibility of liver scintigraphy with Tc-99m DISIDA or Tc-99m tin colloid as a non-invasive tool in predicting functional status of hepatocyte and Kupffer cell and severity of liver injury. Intraperitoneal injection of thioacetamide was performed to make acute liver injury in mice and rats, and liver status was assessed by pathologic specimen and scintigraphic methods. Scintigraphic evaluation were performed by biodistribution of Tc-99m DISIDA or Tc-99m tin colloid in thioacetamide-treated mice. Liver time-activity curves were generated. Comparison between histologic data and scintigraphic data was done with SAS program. Thioacetamide-treated mice demonstrated hepatocyte necrosis in histologic examination and low liver/blood uptake ratios in biodistribution studies using both radiotracers. Biodistribution study using Tc-99m tin colloid revealed increased lung radioactivity in thioacetamide-treated mice. Twenty-four hours after thioacetamide administration, thioacetamide-treated rats demonstrated maximal hepatocyte necrosis and inflammation in histologic finding and delayed maximal uptake time (Tmax) and prolonged half time (T 1/2 ) of liver time-activity curve in liver scintigraphy. Histologic results and scintigraphic data were well correlated, and these two scintigraphic parameters (Tmax T 1/2 ) seemed to be good predictors of histologic change of liver. These data showed that liver injury could be assessed by non-invasive scintigraphic study in rat and mouse. This experimental study might be used as a animal model to evaluate the liver protecting drugs, and this scintigraphic study could be applied to acute toxic hepatitis for assessment of liver status in men

Validation of alternative methods of preparing 99mTc-MAG3

International Nuclear Information System (INIS)

Seetharaman, Shankar; Sosabowski, Michael H.; Ballinger, James R.

2007-01-01

Parameters in the preparation of 99m Tc-mertiatide ( 99m Tc-MAG3) were investigated to determine the importance of total activity, activity concentration, boiling time, and delay before boiling for the radiochemical purity (RCP) and stability of the product. Satisfactory RCP results (>90%) were obtained over a range of concentrations including a dilute preparation for paediatric use. RCP was not affected by the time between the addition of pertechnetate and boiling, but low RCP (<60%) resulted when the kit was boiled for less than 10 min

Tc-99m HMPAO brain uptake patterns in patients with dementia of Alzheimer type

International Nuclear Information System (INIS)

Costa, D.C.; Burns, A.; Philpot, M.; Levy, R.; Ell, P.J.

1988-01-01

Conventional gamma camera SPECT with Tc-99m HMPAO (10 MBq/kg patient weight) was carried out in 21 patients with dementia of Alzheimer type (DAT), fulfilling the criteria established by the National Institute of Neurological and Communicative Disorders and Stroke and the ADRDA criteria (nine with amnesia as the main symptom [group 1], 12 with amnesia, aphasia, and/or apraxia and agnosia [group 2], and eight age-matched control subjects. Perfusion was quantitatively studied by means of cerebrum-cerebellum activity ratios. In group 1, perfusion deficits in the mesial cortex of the temporal lobes (right, 0.70; left, 0.68) were found, and ratios were significantly lower than in the control group (right, 0.77; left, 0.76 [P < .05]). Group 2 showed low ratios throughout both temporal lobes (mesial and lateral cortex), bilaterally in the posterior parietal cortex (right, 0.69; left, 0.66 [control: right, 0.80; left, 0.81] [P < .001]), and left frontal cortex (0.75 [control, 0.79] [P < .05]). In conclusion, SPECT with Tc-99m HMPAO identifies perfusion deficits in patients with DAT, and these correlate well with the clinical findings and are significantly different from those in the control group

Multiple Myeloma-Derived Exosomes Regulate the Functions of Mesenchymal Stem Cells Partially via Modulating miR-21 and miR-146a

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Qian Cheng

2017-01-01

Full Text Available Exosomes derived from cancer cells can affect various functions of mesenchymal stem cells (MSCs via conveying microRNAs (miRs. miR-21 and miR-146a have been demonstrated to regulate MSC proliferation and transformation. Interleukin-6 (IL-6 secreted from transformed MSCs in turn favors the survival of multiple myeloma (MM cells. However, the effects of MM exosomes on MSC functions remain largely unclear. In this study, we investigated the effects of OPM2 (a MM cell line exosomes (OPM2-exo on regulating the proliferation, cancer-associated fibroblast (CAF transformation, and IL-6 secretion of MSCs and determined the role of miR-21 and miR-146a in these effects. We found that OPM2-exo harbored high levels of miR-21 and miR-146a and that OPM2-exo coculture significantly increased MSC proliferation with upregulation of miR-21 and miR-146a. Moreover, OPM2-exo induced CAF transformation of MSCs, which was evidenced by increased fibroblast-activated protein (FAP, α-smooth muscle actin (α-SMA, and stromal-derived factor 1 (SDF-1 expressions and IL-6 secretion. Inhibition of miR-21 or miR-146a reduced these effects of OPM2-exo on MSCs. In conclusion, MM could promote the proliferation, CAF transformation, and IL-6 secretion of MSCs partially through regulating miR21 and miR146a.

Biokinetics and dosimetric studies about 99mTc(V)DMSA distribution

International Nuclear Information System (INIS)

Correia, M.B.L.; Magnata, S.S.L.P.; Silva, I.M.S.; Lima, F.F.; Catanho, M.T.J.A.

2008-01-01

Research for radiodiagnostic agents should considerate biological critical parameters as half-life effective, target/not target uptake ratio and metabolites that together will determinate the biokinetic. Each parameter give own contribution in the absorbed dose. The dimercaptosuccinic acid (DMSA) labeled with 99m Tc(VN) is a radiopharmaceutical which has well established role in medullar thyroid carcinoma and has been proposed in complementary evaluation of bone metastasis. The aim of this work was study the biokinetics and dosimetry of 99m Tc(V)-DMSA by animal model. The 99m Tc(V)-DMSA was prepared by (III)DMSA kit alkalized. The methodology used mice, 70 days old, both males and females. The animals (n=5) received 99m Tc(V)DMSA administered IV (tail vein). After determinate times (30 min, 1h, 5h and 12h) the animals were sacrificed, the organs (blood, lungs, kidneys, muscle and bone) were excised and the activities were measured by a gamma counter. The results were evaluated based on %activity/g and the absorbed dose was estimated by extrapolation of data from animal to human, using the residence time to each organ in the MIRDOSE 3.0 program. The results show that the majority of organs reaches the top uptake at 30 min, the kidney has the greatest uptake in this time, (4.81 ± 1.38) % activity per gram, while the bone presents its highest uptake at 1h (5.49 ± 0.47)% activity per gram, after 1h all the organs had activity exponential decrease. About the absorbed dose estimated to human scale, the preliminary results showed higher value to bone, being the soft tissue dose relatively low. These dose values, however, are submitted to biological implications which are under studying yet. The biokinetic profile of 99m Tc(V)-DMSA, prepared from a DMSA kit by IPEN, was well established, allowing quantifying of residence time, while the dosimetric model presented preliminary data which directs to new analyzes

Calculation of therapeutic activity of radioiodine in Graves' disease by means of Marinelli's formula, using technetium (99mTc) scintigraphy.

Science.gov (United States)

Szumowski, Piotr; Mojsak, Małgorzata; Abdelrazek, Saeid; Sykała, Monika; Amelian-Fiłonowicz, Anna; Jurgilewicz, Dorota; Myśliwiec, Janusz

2016-12-01

The therapeutic activity of 131 I administered to patients with Graves' disease can be calculated by means of Marinelli's formula. The thyroidal iodine uptake ( 131 IU max ) needed for the calculation is usually determined with the use of 131 I. The purpose of the paper was to estimate 131 IU max on the basis of technetium uptake in the thyroid at 20 min ( 99m TcU 20min ). Eighty patients suffering from Graves' disease were qualified for radioiodine therapy with measurement of fT 4 , fT 3 , thyroid-stimulating hormone and its receptor (TRAb). Prior to the treatment, all the patients were euthyroid. 131 IU max for each patient was determined according to the levels of 131 I after 24 h ( 131 IU 24h ), while effective half-life (T eff ) according to the measurements of 131 IU 24h and 131 I uptake after 48 h ( 131 IU 48h ). Additionally, on the day before measuring 131 IU 24h , 99m TcU 20min was calculated for each patient. It was demonstrated that there existed a correlation, with statistical significance at p  10 IU/ml. It is possible to predict thyroid iodine uptake 131 IU 24h in Graves' disease on the basis of measuring the uptake of 99m TcU 20min . This shortens the time necessary for diagnosis and enables the calculation of 131 I activity using Marinelli's formula.

Inhibition of host extracellular signal-regulated kinase (ERK) activation decreases new world alphavirus multiplication in infected cells

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Voss, Kelsey; Amaya, Moushimi [National Center for Biodefense and Infectious Diseases, School of Systems Biology, George Mason University, 10650 Pyramid Place, Manassas, VA (United States); Mueller, Claudius [Center for Applied Proteomics and Personalized Medicine, George Mason University, 10900 University Boulevard, Manassas, VA (United States); Roberts, Brian [Leidos Health Life Sciences, 5202 Presidents Court, Suite 110, Frederick, MD (United States); Kehn-Hall, Kylene; Bailey, Charles [National Center for Biodefense and Infectious Diseases, School of Systems Biology, George Mason University, 10650 Pyramid Place, Manassas, VA (United States); Petricoin, Emanuel [Center for Applied Proteomics and Personalized Medicine, George Mason University, 10900 University Boulevard, Manassas, VA (United States); Narayanan, Aarthi, E-mail: anaraya1@gmu.edu [National Center for Biodefense and Infectious Diseases, School of Systems Biology, George Mason University, 10650 Pyramid Place, Manassas, VA (United States)

2014-11-15

New World alphaviruses belonging to the family Togaviridae are classified as emerging infectious agents and Category B select agents. Our study is focused on the role of the host extracellular signal-regulated kinase (ERK) in the infectious process of New World alphaviruses. Infection of human cells by Venezuelan equine encephalitis virus (VEEV) results in the activation of the ERK-signaling cascade. Inhibition of ERK1/2 by the small molecule inhibitor Ag-126 results in inhibition of viral multiplication. Ag-126-mediated inhibition of VEEV was due to potential effects on early and late stages of the infectious process. While expression of viral proteins was down-regulated in Ag-126 treated cells, we did not observe any influence of Ag-126 on the nuclear distribution of capsid. Finally, Ag-126 exerted a broad-spectrum inhibitory effect on New World alphavirus multiplication, thus indicating that the host kinase, ERK, is a broad-spectrum candidate for development of novel therapeutics against New World alphaviruses. - Highlights: • VEEV infection activated multiple components of the ERK signaling cascade. • Inhibition of ERK activation using Ag-126 inhibited VEEV multiplication. • Activation of ERK by Ceramide C6 increased infectious titers of TC-83. • Ag-126 inhibited virulent strains of all New World alphaviruses. • Ag-126 treatment increased percent survival of infected cells.

Inhibition of host extracellular signal-regulated kinase (ERK) activation decreases new world alphavirus multiplication in infected cells

International Nuclear Information System (INIS)

Voss, Kelsey; Amaya, Moushimi; Mueller, Claudius; Roberts, Brian; Kehn-Hall, Kylene; Bailey, Charles; Petricoin, Emanuel; Narayanan, Aarthi

2014-01-01

New World alphaviruses belonging to the family Togaviridae are classified as emerging infectious agents and Category B select agents. Our study is focused on the role of the host extracellular signal-regulated kinase (ERK) in the infectious process of New World alphaviruses. Infection of human cells by Venezuelan equine encephalitis virus (VEEV) results in the activation of the ERK-signaling cascade. Inhibition of ERK1/2 by the small molecule inhibitor Ag-126 results in inhibition of viral multiplication. Ag-126-mediated inhibition of VEEV was due to potential effects on early and late stages of the infectious process. While expression of viral proteins was down-regulated in Ag-126 treated cells, we did not observe any influence of Ag-126 on the nuclear distribution of capsid. Finally, Ag-126 exerted a broad-spectrum inhibitory effect on New World alphavirus multiplication, thus indicating that the host kinase, ERK, is a broad-spectrum candidate for development of novel therapeutics against New World alphaviruses. - Highlights: • VEEV infection activated multiple components of the ERK signaling cascade. • Inhibition of ERK activation using Ag-126 inhibited VEEV multiplication. • Activation of ERK by Ceramide C6 increased infectious titers of TC-83. • Ag-126 inhibited virulent strains of all New World alphaviruses. • Ag-126 treatment increased percent survival of infected cells

Preparation and biological profile of 99mTc-lidocaine as a cardioselective imaging agent using 99mTc eluted from 99Mo/99mTc generator based on Al-Mo gel

International Nuclear Information System (INIS)

Sakr, T.M.; October University of Modern Sciences and Arts; Ibrahim, A.B.; Rashed, H.M.; Fasih, T.W.

2017-01-01

The current study is aimed to prepare 99m Tc-lidocaine as a new myocardial perfusion-imaging agent. The used 99m Tc was obtained from Al- 99 Mo-molybdate(VI) gel matrix. 99m Tc-lidocaine showed higher (15.4 ± 0.11% ID/g) and faster (15 min post injection) cardiac uptake than the recently studied 99m Tc-valsartan and 99m Tc-procainamide. Consequently, 99m Tc-lidocaine will be a valuable myocardial SPECT agent for diagnosis of emergency patients. Besides, the receptor affinity study confirmed the selectivity of 99m Tc-lidocaine for sodium channels in the heart. (author)

Diagnostic utility of 99mTc-EDDA-tricine-HYNIC-Tyr3-octreotate SPECT for differentiation of active from inactive pulmonary tuberculosis.

Science.gov (United States)

Ahmadihosseini, Hossein; Abedi, Javad; Ghodsi Rad, Mohammad A; Zakavi, Seyed R; Knoll, Peter; Mirzaei, Siroos; Sadeghi, Ramin

2014-12-01

The current study was performed to evaluate the impact of Tc-EDDA-tricine-HYNIC-Tyr-octreotate in the differentiation of active from inactive pulmonary tuberculosis lesions. Ten consecutive patients (six male and four female, age range 24-83 years) with proven pulmonary tuberculosis (with a positive smear or culture) were enrolled in the study. At 120 min after injection of 740 MBq of Tc-EDDA-tricine-HYNIC-Tyr-octreotate, planar and single-photon emission computed tomography (SPECT) images of the thorax were taken. A semiquantitative evaluation of lesion and nonlesion areas was performed. The scan was repeated following the same protocol after standard treatment for tuberculosis after a negative sputum culture. Semiquantitative evaluation of the lesions showed a statistically significant higher uptake before treatment in both planar and SPECT images (P=0.005 and 0.007, respectively). Lesion-to-nonlesion ratios were also higher in the pretreatment sets on both planar and SPECT images (1.4±0.2 vs. 1.19±0.15, P=0.001, for planar images and 2.32±0.55 vs. 1.32±0.32, P=0.0001, for SPECT images). Tc-EDDA-tricine-HYNIC-Tyr-octreotate scintigraphy may help to differentiate between active and inactive pulmonary tuberculosis. SPECT imaging and semiquantitative evaluation are indispensable for increasing the diagnostic yield of this method. Larger studies are needed to corroborate our results.

Soil-to-plant transfer of 99mTc: how to determine Tc-species in uptake and transport processes?

International Nuclear Information System (INIS)

Krijger, G. C.; Van Elswijk, D. A.; Wolterbeek, H. Th.

1995-01-01

Selective extraction, filtration and capillary electrophoresis were used to recognize problems dealing with complexation, oxidation and ligand-exchange processes during collection and analysis of Tc-species in xylem exudates, while 99m Tc-citrate was used as a marker complex. Relatively unstable Tc-species were synthesized in xylem exudates. Oxidation of relative unstable Tc-species during the collection of xylem exudates was suggested, requiring new, better procedures to recognize Tc-species representative for the plant interior. (author)

Study of the biokinetic behavior of 99mTc-DMSA in renal scintigraphy of pediatric patients

International Nuclear Information System (INIS)

Santos, Felipe Simas dos

2013-01-01

In Brazil, renal studies with 99m Tc D TPA and 99m Tc-DMSA constitute about 18% of pediatric diagnostic procedures. A retrospective non-randomized study was conducted in 2010, for absolute quantification of kidney activities. In 2010,51 patients underwent renal studies in the Hospital of the Rio de Janeiro State University - HUPE-UERJ/ RJ, Brazil. 19 of them with 9±4 years of age and body mass of 31.8±20.8 kg showed relative uptake of 99m Tc-DMSA between 45% and 55%. Still images (AP, PA and posterior oblique abdomen incidences) were acquired 4 h after intravenous administration of 115.69±42.31 MBq of 99m Tc-DMSA using gamma camera (Siemens E-Cam), LEHR collimator, matrix of 256x256 and 5min imaging. In 2012, 3 patients (9.3±2.1 years, 31.97±10.75 kg) in the previous study were followed in a prospective study. All urinary excretions samples were collected from administration of 99m Tc-DMSA to 6 h after, while simultaneously images were acquired AP and PA abdominal region with Philips model Picker Prism 2000XP. Aliquots of each urine sample were measured in gamma counter shaft GenesysTM Gamma 1 with Nal (TI) detector. For whole body, the biological half-life estimate was 11.0±2.0 h, and the residence time was found to be 5.6±0.4 h while the literature suggests 4.l±0.5 h for age range studied. Residence time for kidney was found to be 0.7±0.4 h, while the literature shows, 3.07 h and 1.4 h for patients with normal and renal pathologies, respectively. This difference may be attributed to the methodology because while the images were taken during the first 6 h, SMITH et aI. (1996) performed images of the kidneys and whole body 30 h after administration of 99mTc D MSA, incorporating the slow term of biological half-life. For liver, it was found the average residence time of 3.0±0.4 min, whereas the literature indicates 20.8 min and 25.1 min, respectively according to SMITH et. ai (1996) and ICRP (1998). The fact that the administered activity was higher than

C/EBPα regulates CRL4Cdt2-mediated degradation of p21 in response to UVB-induced DNA damage to control the G1/S checkpoint

Science.gov (United States)

Hall, Jonathan R; Bereman, Michael S; Nepomuceno, Angelito I; Thompson, Elizabeth A; Muddiman, David C; Smart, Robert C

2014-01-01

The bZIP transcription factor, C/EBPα is highly inducible by UVB and other DNA damaging agents in keratinocytes. C/EBPα-deficient keratinocytes fail to undergo cell cycle arrest in G1 in response to UVB-induced DNA damage and mice lacking epidermal C/EBPα are highly susceptible to UVB-induced skin cancer. The mechanism through which C/EBPα regulates the cell cycle checkpoint in response to DNA damage is unknown. Here we report untreated C/EBPα-deficient keratinocytes have normal levels of the cyclin-dependent kinase inhibitor, p21, however, UVB-treated C/EBPα-deficient keratinocytes fail to up-regulate nuclear p21 protein levels despite normal up-regulation of Cdkn1a mRNA levels. UVB-treated C/EBPα-deficient keratinocytes displayed a 4-fold decrease in nuclear p21 protein half-life due to the increased proteasomal degradation of p21 via the E3 ubiquitin ligase CRL4Cdt2. Cdt2 is the substrate recognition subunit of CRL4Cdt2 and Cdt2 mRNA and protein levels were up-regulated in UVB-treated C/EBPα-deficient keratinocytes. Knockdown of Cdt2 restored p21 protein levels in UVB-treated C/EBPα-deficient keratinocytes. Lastly, the failure to accumulate p21 in response to UVB in C/EBPα-deficient keratinocytes resulted in decreased p21 interactions with critical cell cycle regulatory proteins, increased CDK2 activity, and inappropriate entry into S-phase. These findings reveal C/EBPα regulates G1/S cell cycle arrest in response to DNA damage via the control of CRL4Cdt2 mediated degradation of p21. PMID:25483090

Preparation and characterization of the tetrabutylammonium salts of the tetrahalooxotechnetates(V), [TcOCl4]- and [TcOBr4]-

International Nuclear Information System (INIS)

Preetz, W.; Peters, G.

1980-01-01

The treatment of (TBA)TcO 4 with conc. HCl or HBr at room temperature yields (TBA) [TcOCl 4 ] or (TBA) [TcOBr 4 ], which are nearly insoluble in acidic aqueous solutions, but well soluble in organic solvents. The vibrational spectra indicate C 4 sub(v) symmetry for the complex ions. (TBA) [TcOBr 4 ] shows an unusual resonance Raman effect, as the progression of overtones runs with the B 1 TcCl 4 stretching vibration instead of the symmetric A 1 mode. The coupling of B 1 with the first overtone of νTcO gives more intense difference than combination bands. (orig.)

Novel Tc-99m radiotracers for brain imaging

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