Studies on chemical effects on x-ray intensity ratios of K/sub β//K/sub α/ in nuclear decay of technetium nuclides /sup 99m/Tc, /sup 97m/Tc, and /sup 95m/Tc

International Nuclear Information System (INIS)

Yamoto, I.; Kaji, H.; Yoshihara, K.

1986-01-01

Chemical effects of characteristic x-ray intensity ratios of K/sub β//K/sub α/ were investigated for the second d-group element Tc in the decay processes /sup 99m/Tc → 99 Tc (two-step isomeric transition), /sup 97m/Tc → 97 Tc (one-step isomeric transition), and /sup 95m/Tc → 95 Mo (electron capture). The objective nuclides were produced by (n, γ)β - , (d, xn), and (α, xn) reactions and were chemically separated from the target materials. The x rays were measured with a pure germanium detector, and the K/sub β/ x rays were analyzed into the two components K/sup prime//sub beta1/ and K/sup //sub beta2/ using a computer program. The chemical effect of the intensity ratio was more pronounced for K/sup prime//sub beta2//K/sub α/ than for K/sup //sub beta1//K/sub α/, as expected. The effect was larger in KTcO 4 than in the other species of Tc 2 S 7 , K 2 TcCl 6 , and Tc metal. The effect in the two-step isomeric transition in /sup 99m/Tc was found to be larger than in the one-step isomeric transition in /sup 97m/Tc. The effect in the electron capture in /sup 95m/Tc (Mo x rays) was similar to that in /sup 97m/Tc although the ratio K/sub β//K/sub α/ was smaller in /sup 95m/Tc than in /sup 97m/Tc, reflecting the change of nuclear charge. The tendency of the observed chemical effect was explained by taking into account the interfering factors which involve Pauling's ionicity in chemical bonding between Tc and its counter atom

Non-MTC gait cycles: An adaptive toe trajectory control strategy in older adults.

Science.gov (United States)

Santhiranayagam, Braveena K; Sparrow, W A; Lai, Daniel T H; Begg, Rezaul K

2017-03-01

Minimum-toe-clearance (MTC) above the walking surface is a critical representation of toe-trajectory control due to its association with tripping risk. Not all gait cycles exhibit a clearly defined MTC within the swing phase but there have been few previous accounts of the biomechanical characteristics of non-MTC gait cycles. The present report investigated the within-subject non-MTC gait cycle characteristics of 15 older adults (mean 73.1 years) and 15 young controls (mean 26.1 years). Participants performed the following tasks on a motorized treadmill: preferred speed walking, dual task walking (carrying a glass of water) and a dual-task speed-matched control. Toe position-time coordinates were acquired using a 3 dimensional motion capture system. When MTC was present, toe height at MTC (MTC height ) was extracted. The proportion of non-MTC gait cycles was computed for the age groups and individuals. For non-MTC gait cycles an 'indicative' toe height at the individual's average swing phase time (MTC time ) for observed MTC cycles was averaged across multiple non-MTC gait cycles. In preferred-speed walking Young demonstrated 2.9% non-MTC gait cycles and Older 18.7%. In constrained walking conditions both groups increased non-MTC gait cycles and some older adults revealed over 90%, confirming non-MTC gait cycles as an ageing-related phenomenon in lower limb trajectory control. For all participants median indicative toe-height on non-MTC gait cycles was greater than median MTC height . This result suggests that eliminating the biomechanically hazardous MTC event by adopting more of the higher-clearance non-MTC gait cycles, is adaptive in reducing the likelihood of toe-ground contact. Copyright © 2017 Elsevier B.V. All rights reserved.

Left ventricular function assessment using 123I/99mTc dual-isotope acquisition with two semi-conductor cadmium–zinc–telluride (CZT cameras: a gated cardiac phantom study

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Tanguy Blaire

2016-11-01

Full Text Available Abstract Background The impact of increased energy resolution of cadmium–zinc–telluride (CZT cameras on the assessment of left ventricular function under dual-isotope conditions (99mTc and 123I remains unknown. The Amsterdam-gated dynamic cardiac phantom (AGATE, Vanderwilt techniques, Boxtel, The Netherlands was successively filled with a solution of 123I alone, 99mTc alone, and a mixture of 123I and 99mTc. A total of 12 datasets was acquired with each commercially available CZT camera (DNM 530c, GE Healthcare and DSPECT, Biosensors International using both energy windows (99mTc or 123I with ejection fraction set to 33, 45, and 60 %. End-diastolic (EDV and end-systolic (ESV volumes, ejection fraction (LVEF, and regional wall motion and thickening (17-segment model were assessed using Cedars-Sinai QGS Software. Concordance between single- and dual-isotope acquisitions was tested using Lin’s concordance correlation coefficient (CCC and Bland–Altman plots. Results There was no significant difference between single- or simultaneous dual-isotope acquisition (123I and 99mTc for EDV, ESV, LVEF, or segmental wall motion and thickening. Myocardial volumes using single- (123I, 99mTc and dual-isotope (reconstructed using both 123I and 99mTc energy windows acquisitions were, respectively, the following: EDV (mL 88 ± 27 vs. 89 ± 27 vs. 92 ± 29 vs. 90 ± 26 for DNM 530c (p = NS and 82 ± 20 vs. 83 ± 22 vs. 79 ± 19 vs. 77 ± 20 for DSPECT (p = NS; ESV (mL 40 ± 1 vs. 41 ± 2 vs. 41 ± 2 vs. 42 ± 1 for DNM 530c (p = NS and 37 ± 5 vs. 37 ± 1 vs. 35 ± 3 vs. 34 ± 2 for DSPECT (p = NS; LVEF (% 52 ± 14 vs. 51 ± 13 vs. 53 ± 13 vs. 51 ± 13 for DNM 530c (p = NS and 52 ± 16 vs. 54 ± 13 vs. 54 ± 14 vs. 54 ± 13 for DSPECT (p = NS; regional motion (mm 6.72 ± 2.82 vs. 6.58 ± 2.52 vs. 6.86 ± 2.99 vs. 6.59 ± 2

To the radiotoxicity of {sup 99m}Tc radiopharmaceuticals

Energy Technology Data Exchange (ETDEWEB)

Ftacnikova, S [Inst. of Preventive and Clinical Medicine, 83301 Bratislava (Slovakia)

1996-12-31

In this paper the radiotoxicity and RBE values of Auger electrons for {sup 99m}Tc radiopharmaceuticals were discussed. Expression for the expected RBE for {sup 99m}Tc compounds is given. For the Auger electrons emitted in the decay of {sup 99m}Tc the RBE(Auger) = 10 and a value of 20 for the radiation weighing factor were recommended. (J.K.) 4 refs.

{sup 99m}Tc sestamibi imaging. Can it be a useful substitute for hepatobiliary scintigraphy in infantile jaundice?

Energy Technology Data Exchange (ETDEWEB)

Sadeghi, R.; Kakhki, V.R.D.; Zakavi, R. [Mashhad Univ. of Medical Sciences (Iran). Nuclear Medicine Dept.; Kianifar, H.R. [Mashhad Univ. of Medical Sciences (Iran). Paediatric Dept.; Ansari, K. [Tehran Univ. of Medical Sciences (Iran). Nuclear Medicine Dept.

2009-07-01

Hepatobiliary scintigraphy is an integral part in the diagnostic work-up of the neonatal cholestasis syndrome. However, less than optimal specificity is its major disadvantage. Differentiation between biliary atresia and neonatal hepatitis is nearly impossible in some cases with poor hepatocellular function. {sup 99m}Tc sestamibi (MIBI) is a cationic lipophilic agent which is a substrate of P-glycoprotein. This glycoprotein is normally expressed in biliary canalicular surfaces of hepatocytes. This property provides a hepatic excretory mechanism which is different from bilirubin excretion. In this study we evaluated the value of {sup 99m}Tc MIBI in differential diagnosis of neonatal cholestasis. 20 infants with a mean age of 2.41 months (range, 0.1-5 months) were included in the study. Ten infants turned out to have extrahepatic biliary atresia and the other ten had neonatal hepatitis. Hepatobiliary (with {sup 99m}Tc BrIDA) and {sup 99m}Tc MIBI scintigraphy were performed for all the patients. {sup 99m}Tc MIBI scintigraphy has shown bowel activity in all patients, including the patients with biliary atresia. Hepatobiliary scintigraphy revealed bowel activity only in five patients with neonatal hepatitis. Bowel visualization with {sup 99m}Tc MIBI may be seen in patients with biliary atresia and {sup 99m}Tc MIBI has limited value in differential diagnosis of neonatal cholestasis. (orig.)

Benchmark experiment for the cross section of the 100Mo(p,2n)99mTc and 100Mo(p,pn)99Mo reactions

Science.gov (United States)

Takács, S.; Ditrói, F.; Aikawa, M.; Haba, H.; Otuka, N.

2016-05-01

As nuclear medicine community has shown an increasing interest in accelerator produced 99mTc radionuclide, the possible alternative direct production routes for producing 99mTc were investigated intensively. One of these accelerator production routes is based on the 100Mo(p,2n)99mTc reaction. The cross section of this nuclear reaction was studied by several laboratories earlier but the available data-sets are not in good agreement. For large scale accelerator production of 99mTc based on the 100Mo(p,2n)99mTc reaction, a well-defined excitation function is required to optimise the production process effectively. One of our recent publications pointed out that most of the available experimental excitation functions for the 100Mo(p,2n)99mTc reaction have the same general shape while their amplitudes are different. To confirm the proper amplitude of the excitation function, results of three independent experiments were presented (Takács et al., 2015). In this work we present results of a thick target count rate measurement of the Eγ = 140.5 keV gamma-line from molybdenum irradiated by Ep = 17.9 MeV proton beam, as an integral benchmark experiment, to prove the cross section data reported for the 100Mo(p,2n)99mTc and 100Mo(p,pn)99Mo reactions in Takács et al. (2015).

Scintigraphies after renal transplant: study of transplant function and of sup(99m)Tc labelled lymphocytes transit

Energy Technology Data Exchange (ETDEWEB)

Guey, A; Touraine, J L; Collard, M; Traeger, J [Institut National de la Sante et de la Recherche Medicale (INSERM), Hopital Edouard-Herriot, 69 - Lyon (France)

1977-01-01

In a first series of scintigraphic investigations in patients with a renal transplant, 'conventional' tracers, were used (sup(99m)Tc pertechnetate and sodium iodohippurate iodine-131) and they gave insight on alteration of the function of the transplanted kidney. Precisions on scintigraphic criteria of diagnosis of vascular complications and urinary fistulae were obtained but no clear cut discrimination between ischemic acute tubular necrosis and early rejection was apparent. Despite the use of a data acquisition and processing system (SCINTI-16) and despite improved functional characterization of the transplant, such methods do not appear to provide definite criteria for an early diagnosis of acute rejection. A different approach, using lymphocytes as a vector, was investigated. A method for lymphocyte labelling with sup(99m)Tc was developed. Labelled autologous lymphocytes were injected to normal volunteers and to patients, then the body distribution was determined and followed over a period of 24 hours. The activity was more precisely quantified at the site of the transplant, repeatedly for 24 hours following injection, and the resulting curves were altered in phases of preclinical rejection. The lymphocyte transit in the kidney would be slower during acute rejection crises of the transplanted kidney and this might be responsible for the different aspect of the curve, especially at 3 to 5 hours. This working hypothesis, will be analysed and documented, using more precise quantifications (close selection of the studied area), evaluating the intrarenal transit of each lymphocyte subpopulation and accurately measuring isotope release. It will then perhaps be possible to define very precise and precocious criteria of rejection.

{sup 99m}Tc Nanocoll: A radiopharmaceutical for sentinel node localisation in breast cancer-In vitro and in vivo results

Energy Technology Data Exchange (ETDEWEB)

Gommans, G.M.M. [Department of Nuclear Medicine, West-Fries Hospital Hoorn (Netherlands); Department of Nuclear Medicine (0030), Medical Centre Alkmaar, Wilhelminalaan 12, 1815 JD Alkmar (Netherlands)], E-mail: g.m.m.gommans@mca.nl; Gommans, E. [Department of Chemical Engineering, Twente University of Technology (Netherlands); Zant, F.M. van der [Department of Nuclear Medicine (0030), Medical Centre Alkmaar, Wilhelminalaan 12, 1815 JD Alkmar (Netherlands); Teule, G.J.J. [Department of Nuclear Medicine, University Medical Centre Maastricht (Netherlands); Schors, T.G. van der [Department of Clinical Pharmacy, West-Fries Hospital Hoorn (Netherlands); Waard, J.W.D. de [Department of Surgery, West-Fries Hospital Hoorn (Netherlands)

2009-09-15

This study evaluated labelling efficiency and radiochemical purity of {sup 99m}Tc colloid albumin to identify an optimal labelling protocol for sentinel node detection. Results indicate that a 72 h eluate is not recommended for high specific labelling of {sup 99m}Tc colloid albumin. Ex vivo, significantly higher count rates were reached using a 2 h eluate in vacuum or nitrogen. Labelling 26 MBq/{mu}g {sup 99m}Tc colloid albumin with a 2 h eluate under nitrogen is recommended because of the ease of labelling.

In vitro studies of leukocyte labeling with /sup 99m/Tc

International Nuclear Information System (INIS)

Uchida, T.; Vincent, P.C.

1976-01-01

A method for labeling leukocytes in vitro with /sup 99m/Tc is described. Separated leukocytes are incubated with /sup 99m/Tc, followed by reduction with stannous chloride and washing with acid citrate dextrose solution. Maximum labeling occurs after at least 5 min incubation with pertechnetate, followed by at least 10 min incubation with stannous chloride. Labeling is similar at room temperature and at 37 0 C. The labeled leukocytes are viable, and reutilization of label does not occur in vitro. In acid conditions (pH 5.2), the elution of /sup 99m/Tc from leukocytes is comparable with that of 32 P-diisopropylfluorophosphate, but /sup 99m/Tc elution is greater at pH 7.2 to 7.4. Neutrophils label more heavily with /sup 99m/Tc than do monocytes, lymphocytes, erythrocytes, or platelets

Expression of mtc in Folsomia candida indicative of metal pollution in soil

International Nuclear Information System (INIS)

Nota, Benjamin; Vooijs, Riet; Straalen, Nico M. van; Roelofs, Dick

2011-01-01

The soil-living springtail Folsomia candida is frequently used in reproduction bioassays to assess soil contamination. Alternatively, the response of genes to contamination is assessed. In this study the expression of F. candida's gene encoding the deduced metallothionein-like motif containing protein (MTC) was assessed, using quantitative PCR, in response to six different metals, each at two concentrations in soil. The expression of mtc was induced after exposure to all metals, except for one chromium concentration. Exposure to soil originating from metal-contaminated field sites also induced mtc, while the expression did not change in response to a polycyclic aromatic hydrocarbon. Since this transcript is induced by most of the tested metals, it may potentially be a good indicator of metal contamination. The presented gene expression assay might become a useful tool to screen potentially polluted sites, in order to identify the ones that need further ecotoxicological investigation. - Highlights: → mtc expression in the springtail Folsomia candida is measured in response to different metals. → Expression of this gene changed in response to all tested metals, except for one. → Metal-contaminated field soils also changed the expression of mtc significantly. → The polycyclic aromatic hydrocarbon phenanthrene did not change mtc's expression. → mtc expression may be a specific indicator of metal soil contamination. - Exposure to metal containing soil induces the expression of mtc in the springtail Folsomia candida.

Compensation of Cross-Contamination in Simultaneous 201Tl/99mTc Myocardial Perfusion SPECT Imaging

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Faraz Kalantari

2009-12-01

Full Text Available Introduction: It is a common protocol to use 201Tl for the rest and 99mTc for the stress cardiac SPECT imaging. Theoretically, both types of imaging may be performed simultaneously using different energy windows for each radionuclide. However, a potential limitation is the cross-contamination of scattered photons from 99mTc and collimator X-rays into the 201Tl energy window. We used a middle energy window method to correct this cross-contamination. Material and Methods: Using NCAT, a typical software torso phantom was generated. An extremely thin line source of 99mTc activity was placed inside the cardiac region of the phantom and no activity in the other parts.  The SimSET Monte Carlo simulator was used to image the phantom in different energy windows. To find the relationship between projections in different energy windows, deconvolution theory was used. We investigated the ability of the suggested functions in three steps: Monte Carlo simulation, phantom experiment and clinical study. In the last step, SPECT images of eleven patients who had angiographic data were acquired in different energy windows. All of these images were compared by determining the contrast between a defect or left ventricle cavity and the myocardium. Results: We found a new 2D kernel which had an exponential pattern with a much higher center. This function was used for modeling 99mTc down scatter distribution from the middle window image. X-ray distribution in the 201Tl window was also modeled as the 99mTc photopeak image convolved by a Gaussian function. Significant improvements in the contrasts of the simultaneous dual 201Tl images were found in each step before and after reconstruction. In comparison with other similar methods, better results were acquired using our suggested functions. Conclusion: Our results showed contrast improvement in thallium images after correction, however, many other parameters should be evaluated for clinical approaches. There are many

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.

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

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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.

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

Sup(99m)Tc compounds for diagnostic purposes

International Nuclear Information System (INIS)

Cifka, J.; Budsky, F.

1980-01-01

The applications of sup(99m)Tc in nuclear medicine are discussed, such as sodium pertechnetate in thyroid and brain scintigraphy, complex compounds in lungs and liver diao.nosis. Technetium generators are classified according to the method of separating sup(99m)Tc from 99 Mo. Adsorption generators are used, molybdate-99 is adsorbed on an Al 2 O 3 -packed column while pertechnetate-99m is eluted with 0.9% NaCl solution. Also used is continuous pertechnetate-99m extraction with methyl ethyl ketone from 0.5 M potassium molybdate and 2.5 M of potassium carbonate. The manufacture is described of kits for sup(99m)Tc radiopharmaceuticals preparation, eg., Diagos I, a gluconate complex, a lyophilisate for sup(99m)Tc-sodium pyrophosphate injections, a diagnostic kit for lung scintiscanning. (H.S.)

Transport of /sup 99m/Tc complexes through the blood-brain barrier

International Nuclear Information System (INIS)

Loberg, M.D.; Corder, E.H.; Fields, A.T.; Callery, P.S.

1979-01-01

Thirteen /sup 99m/Tc complexes have been synthesized and used to determine the relationships between protein binding, lipophilicity and membrane transport. The lipophilicity of the /sup 99m/Tc complexes was altered by adding substituents to either IDA, EDTA, DTPA or oxine; membrane transport was estimated using the brain uptake index (BUI) method. The BUI of the /sup 99m/Tc complexes was found to vary directly with lipophilicity and inversely with protein binding. These results demonstrated that /sup 99m/Tc-oxine derivatives are better suited for use in the development of intracellular tracers than are the /sup 99m/Tc derivatives of aminopolycarboxylates

Design of an X -band electron linear accelerator dedicated to decentralized 99Mo/99mTc supply: From beam energy selection to yield estimation

Science.gov (United States)

Jang, Jaewoong; Yamamoto, Masashi; Uesaka, Mitsuru

2017-10-01

The most frequently used radionuclide in diagnostic nuclear medicine, 99mTc, is generally obtained by the decay of its parent radionuclide, 99Mo. Recently, concerns have been raised over shortages of 99Mo/99mTc, owing to aging of the research reactors which have been supplying practically all of the global demand for 99Mo in a centralized fashion. In an effort to prevent such 99Mo/99mTc supply disruption and, furthermore, to ameliorate the underlying instability of the centralized 99Mo/99mTc supply chain, we designed an X -band electron linear accelerator which can be distributed over multiple regions, whereby 99Mo/99mTc can be supplied with improved accessibility. The electron beam energy was designed to be 35 MeV, at which an average beam power of 9.1 kW was calculated by the following beam dynamics analysis. Subsequent radioactivity modeling suggests that 11 of the designed electron linear accelerators can realize self-sufficiency of 99Mo/99mTc in Japan.

Design of an X-band electron linear accelerator dedicated to decentralized ^{99}Mo/^{99m}Tc supply: From beam energy selection to yield estimation

Directory of Open Access Journals (Sweden)

Jaewoong Jang

2017-10-01

Full Text Available The most frequently used radionuclide in diagnostic nuclear medicine, ^{99m}Tc, is generally obtained by the decay of its parent radionuclide, ^{99}Mo. Recently, concerns have been raised over shortages of ^{99}Mo/^{99m}Tc, owing to aging of the research reactors which have been supplying practically all of the global demand for ^{99}Mo in a centralized fashion. In an effort to prevent such ^{99}Mo/^{99m}Tc supply disruption and, furthermore, to ameliorate the underlying instability of the centralized ^{99}Mo/^{99m}Tc supply chain, we designed an X-band electron linear accelerator which can be distributed over multiple regions, whereby ^{99}Mo/^{99m}Tc can be supplied with improved accessibility. The electron beam energy was designed to be 35 MeV, at which an average beam power of 9.1 kW was calculated by the following beam dynamics analysis. Subsequent radioactivity modeling suggests that 11 of the designed electron linear accelerators can realize self-sufficiency of ^{99}Mo/^{99m}Tc in Japan.

The Clinical usefulness of {sup 99mT}c HMPAO Leukocyte/{sup 99mT}c phytate bone marrow scintigraphy for diagnosis of prosthetic knee infection: A preliminary study

Energy Technology Data Exchange (ETDEWEB)

Jung, Kyung Pyo; Park, Ji Sun; Lee, Ah Young; Choi, Su Jung; Lee, Seok Mo; Bae, Sang Kyun [Inje Univ., Pusan Paik Hospital, Pusan (Korea, Republic of)

2012-12-15

The preferred radionuclide imaging procedure for diagnosing prosthetic joint infection is combined radiolabeled leukocyte/{sup 99mT}c sulfur colloid bone marrow scintigraphy, which has an accuracy of over 90%. Unfortunately, sulfur colloid is no longer available in South Korea. in this study, we evaluated the usefulness of {sup 99mT}c phytate, a substitute for {sup 99mT}c sulfur colloid, when combined with radiolabeled leukocyte scintigraphy in suspected prosthetic knee infections. Eleven patients (nine women, two men; mean age 72{+-}6 years) with painful knee prostheses and a suspicion of infection underwent both {sup 99mT}c phytate bone marrow scintigraphy (BMS). The combined images were interpreted as positive for infection when radioactivity in the LS at the sits of clinical interest clearly exceeded that of the BMS (discordant); they were interpreted as negative when the increased activity in the LS was consistent with an increased activity in the BMS(concordant). The final diagnosis was made with microbiological or intraoperative findings and a clinical follow up of at least 12 months. Five of eleven patients were diagnosed as having an infected prosthesis. The overall sensitivity, specificity, specificity, positive predictive value (PPV), negative predictive value (NPV), and diagnostic accuracy of the combined LS/BMS were 100%, 83%, 83%, 100% and 91%, respectively. We find that combined {sup 99mT}c HMPAO LS/{sup 99mT}c phytate BMS shows comparable diagnostic performance to other studies utilizing sulfur colloid. Combined {sup 99mT}c HMPAO LS/{sup 99mT}c phytate BMS is therefore expected to be an acceptable alternative to combined radiolabeled LS/{sup 99ms}ulfur colloid BMS for diagnosing prosthetic knee infections.

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

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)

Studies of techniques for the post-elution concentration of 99mTc obtained from gel type 99Mo/99mTc generators

International Nuclear Information System (INIS)

Suzuki, Katia Noriko

2009-01-01

On average 80% of the radiopharmaceuticals used in Nuclear Medicine are labeled with 99 mTc due to its physical properties and easy attainment through of 99 Mo/ 99 mTc generators. The Directory of Radiopharmacy (DIRF) of IPEN-CNEN/SP developed a gel type chromatographic generator of MoZr with 99 Mo produced by 98 Mo(n,γ) 99 Mo reaction that occurs at the IEA-R1 Nuclear Reactor. The gel is composed of zirconium molybdate with elution volume of 12 mL with an activity of 11100 MBq (300 mCi) producing a radioactive concentration of 925 MBq (25 mCi)/mL. The fission generator gives a higher radioactive concentration around 1850 MBq (50 mCi)/mL. The aim of this work is to study a system of post-elution concentration of 99 mTc for the attainment of a high enough radioactive concentration to meet the demands of the market, with a proved quality. Two types of systems of post-elution concentration were developed: the single and the tandem. The most appropriate system for the gel generator of 99 Mo/ 99 mTc, being at the same time sterile and vacuum automated, was the tandem system using Dionex 2.5 cc/QMA cartridges. The gel generator is eluted with 10 mL of solution of 0.1% NaCl and the pertechnetate anion is retained in the QMA cartridge and further eluted with 4 mL of saline. The process takes no more than 30 minutes. The elution efficiency of the system of concentration was 90 %. At the beginning of 2009 a global crisis in the supply of 99 Mo took place making it necessary the development of alternative technologies for the production of 99 Mo/ 99 mTc generators using fission produced 99 Mo and the development of an appropriate method to extend the useful life of this generator. The results of this study showed that the same system developed for the post- concentration of the gel generator can be employed for the fission generator, using the tandem system, giving a concentration factor of 3 for the elution of 99 mTc. (author)

Comparative uptake of 67Ga and /sup 99m/Tc MDP in rabbits with a benign noninfected bone lesion (fracture)

International Nuclear Information System (INIS)

Bushberg, J.T.; Hoffer, P.B.; Schreiber, G.J.; Lawson, A.J.; Lawson, J.P.; Lord, P.

1985-01-01

Mid-shaft fractures of the radius and ulna were produced in 3 to 4 kg New Zealand white rabbits and quantitative uptake of /sup 99m/Tc MDP and 67 Ga determined at 11, 18, 25, 32, 51, and 78 days following fracture. Two hundred microCi of 67 Ga was administered 24 hours prior to sacrifice and 1.5 mCi /sup 99m/Tc MDP 2 hours prior to sacrifice. Specific activity ratios (SARs) were determined between fracture and control sides for bone, muscle and skin. SARs for bone were surprisingly similar for /sup 99m/Tc MDP and 67 Ga, reaching peak values of 6.07 +/- 0.64 (/sup 99m/Tc 18 days); 6.58 +/- 0.90 ( 67 Ga 32 days), subsequently decreasing to minimum values at 78 days postfracture (/sup 99m/Tc MDP 2.25 +/- 0.14; 67 Ga 2.18 +/- 0.08). There was no statistically significant difference in SAR for /sup 99m/Tc MDP vs. 67 Ga in bone at any time after fracture. Whole sections of limb were resected on selected animals and activity ratios determined for these sections as a function of the contribution of activity from the various tissues in the volume of interest. Total activity ratios of 67 Ga were lower than bone SARs as a result of the contribution of activity from muscle and skin. Thus, the apparent lower activity ratios noted on 67 Ga images compared with /sup 99m/Tc MDP images in this fracture model were not due to differences in bone SARs but rather due to the higher soft tissue background activity contribution in the 67 Ga images

Separation of sup(99m)Tc from 99MoO3

International Nuclear Information System (INIS)

Tomicic, M.

1977-07-01

At the present time sup(99m)Tc is widely used in nuclear medicine and its uses are increasing. It can be produced by various methods, and of those most frequently used today two have special features making them particularly applicable to the large-scale production of instant sup(99m)Tc - these are solvent extraction with methyl-ethyl-ketone and the sublimation methods. This report presents a bibliographic review of these methods, their main perfomance parameters, and experience obtained from the development and operation of a sublimation generator. Separation of sup(99m)Tc from irradiated MoO 3 was carried out with high yields (75-95%) after multiple repetition of the separation process with molybdenum trioxide heated for half an hour at a maximum temperature of 850-890 deg C in an air flow. The activity ratio of molybdenum in the separated sup(99m)Tc was of the order of 4 x 10 -5 . (author)

Preperation and performance of {sup 99}Mo/{sup 99m}Tc chromatographic column generator based on zirconium molybdosilicate

Energy Technology Data Exchange (ETDEWEB)

Mostafa, M.; Saber, H.M.; El-Sadek, A.A. [Atomic Energy Authority, Cairo (Egypt). Hot Labs. Center; Nassar, M.Y. [Benha Univ. (Egypt). Chemistry Dept.

2016-08-01

Zirconium molybdosilicate (ZrMoSi) gel prepared using {sup 99}Mo radiotracer via peroxo route was used as a base material for {sup 99}Mo/{sup 99m}Tc column generator. The {sup 99m}Tc elution yield and {sup 99}Mo breakthrough in the eluate were studied as a function of the pH-value of gel precipitation, gel drying temperature and Zr: Mo: Si molar ratio. Precipitation pH-value of 2, drying temperature of 100 C and Zr: Mo: Si molar ratio of 0.5: 0.5: 1 were found to be the optimum conditions achieving {sup 99m}Tc elution yield of 82% and {sup 99}Mo breakthrough of 1.0 x 10{sup -3}%. The gel prepared with the optimum conditions was characterized by BET surface area and pore size analyzer, IR spectroscopy, thermal analysis (TGA and DTA), XRD, XRF and FESEM. Technetium-99m eluted from the optimum ZrMoSi {sup 99}Mo/{sup 99m}Tc generator was found to have a high radiochemical purity (98% as {sup 99m}TcO{sub 4}{sup -}) and chemical purity meeting criteria of clinical grade.

Development of 99mTc agents for imaging central neural system receptors

International Nuclear Information System (INIS)

2004-01-01

development was being pursued in a few laboratories. The CRP, in which ten laboratories from Asia, Europe and Latin America participated, was concluded in 2001. Four Research Co-ordination Meetings (RCMs) to review the results were held: in Dresden, Athens, Montevideo and at IAEA headquarters in Vienna. There was considerable collaboration and co-operation between the participating laboratories. The results of the work carried out in the participating laboratories under the CRP are described in this report. It is expected that these will be useful for radiopharmaceutical scientists worldwide who are working on the development of 99mTc radiopharmaceuticals in general and 99mTc CNS agents in particular

Suggested treaty benefits approaches for collective investment vehicles (CIVs) and its investors under the OECD MTC 2010 update

NARCIS (Netherlands)

Vermeulen, H.; Weber, D.; van Weeghel, S.

2012-01-01

Collective Investment Vehicles (CIVs) are specifically addressed in the 2010 update of the OECD Model Tax Convention (MTC) and the Commentary thereto. Attention is paid to the tax treaty position of CIVs in an international context. The main question is whether a CIV is treaty eligible and if not,

Studies on {sup 99}Mo-{sup 99m}Tc adsorption and elution behaviors using the inorganic sorbent ceric tungstate and conventional organic resins

Energy Technology Data Exchange (ETDEWEB)

El-Sweify, Fatma H.; Fattah, Alaa El-Din A. Abdel; Aly, Shorouk M.; Ghamry, Mohamed A. [Atomic Energy Authority, Cairo (Egypt). Hot Laboratories Center; El-Sheikh, Ragaa [Zagazig Univ. (Egypt). Chemistry Dept.

2017-09-01

Adsorption behavior of {sup 99}Mo(VI) and {sup 99m}Tc(VII) was studied on ceric tungstate (CeW) and compared with the adsorption on the conventional cation and anion exchangers Dowex-50X8 and AG-2X8, respectively. The studies were carried out under static and dynamic conditions. The effect of contact time and pH on the adsorption was investigated under static conditions. High K{sub d}-values for sorption of {sup 99}Mo(VI) on (CeW) were obtained over the investigated pH range. {sup 99m}Tc was adsorbed with much lower K{sub d}-values. The K{sub d}-values were pH dependent. K{sub d}-values of {sup 99}Mo-adsorption on AG-2X8 were lower than those on (CeW) and vice versa for {sup 99m}Tc. Ionic species of both elements were not adsorbed on Dowex-50X8, indicating the absence of cationic species and the adsorption of both elements on AG-2X8 and (CeW) as anionic species. The loading and elution behaviors of {sup 99}Mo and {sup 99m}Tc on (CeW) were studied using different eluents. {sup 99}Mo remained strongly adsorbed under all conditions whereas {sup 99m}Tc was easily eluted. Adsorption of some fission products, i.e. {sup 95}Zr(IV) and {sup 95}Nb(V), in addition to {sup 123m}Te(IV) and {sup 75}Se(IV), as representatives of their corresponding fission product isotopes, as well as {sup 181}Hf, as probable radioactive contaminant was also studied. Solutions of the ionic species of those metals were loaded in mixtures together with {sup 99}Mo on (CeW) columns. Strong adsorption of those ionic species and {sup 99}Mo on (CeW) was found whereas {sup 99m}Tc was easily eluted. Different eluents were investigated for eluting {sup 99m}Tc from {sup 99}Mo-adsorbed on (CeW).

Development of a non-intrusive method for the determination of the moderator temperature coefficient of reactivity (MTC)

International Nuclear Information System (INIS)

Demaziere, C.

2000-01-01

The Moderator Temperature Coefficient of reactivity (MTC) plays an important role in the feedback mechanism and thus in the inherent stability of Pressurised Water Reactors (PWRs). Due to the inaccuracy of the traditional at-power MTC measurement techniques, many power utilities nowadays only measure the zero-power MTC since its determination is relatively straightforward and accurate. For the at-power MTC determination during the remaining fuel cycle, core calculations are assumed to be reliable enough. Nevertheless, these calculations were never benchmarked and most importantly, the use of high burnup fuel might induce a slightly positive MTC at Beginning Of Cycle (BOC) due to the high initial boron concentration. Even if in such a case the Doppler effect would still insure a negative reactivity feedback, monitoring the MTC throughout the cycle could become crucial. In this respect, not only the sign of the MTC is of importance, but also its magnitude. Consequently, developing a method that would permit monitoring the MTC during the fuel cycle is of great interest. One of the main disadvantages of the traditional at-power MTC measurement techniques is that the reactor has to be perturbed in order to induce a change of the moderator temperature. The modification of other parameters that can only be estimated by core calculation represents also a severe drawback of these methods, both for their precision and their reliability. A measurement performed at Ringhals-4 by using the so-called boron dilution method revealed that the uncertainty associated to the MTC estimation could even be much larger than previously expected due to the calculated reactivity corrections. These corrections are very sensitive to the input parameters chosen for the core simulation, and slight mis-estimations of these have large reactivity effects. It is known that if the reactivity noise and the moderator temperature noise could be measured, the MTC could be determined without disturbing

Development of a non-intrusive method for the determination of the moderator temperature coefficient of reactivity (MTC)

Energy Technology Data Exchange (ETDEWEB)

Demaziere, C

2000-07-01

The Moderator Temperature Coefficient of reactivity (MTC) plays an important role in the feedback mechanism and thus in the inherent stability of Pressurised Water Reactors (PWRs). Due to the inaccuracy of the traditional at-power MTC measurement techniques, many power utilities nowadays only measure the zero-power MTC since its determination is relatively straightforward and accurate. For the at-power MTC determination during the remaining fuel cycle, core calculations are assumed to be reliable enough. Nevertheless, these calculations were never benchmarked and most importantly, the use of high burnup fuel might induce a slightly positive MTC at Beginning Of Cycle (BOC) due to the high initial boron concentration. Even if in such a case the Doppler effect would still insure a negative reactivity feedback, monitoring the MTC throughout the cycle could become crucial. In this respect, not only the sign of the MTC is of importance, but also its magnitude. Consequently, developing a method that would permit monitoring the MTC during the fuel cycle is of great interest. One of the main disadvantages of the traditional at-power MTC measurement techniques is that the reactor has to be perturbed in order to induce a change of the moderator temperature. The modification of other parameters that can only be estimated by core calculation represents also a severe drawback of these methods, both for their precision and their reliability. A measurement performed at Ringhals-4 by using the so-called boron dilution method revealed that the uncertainty associated to the MTC estimation could even be much larger than previously expected due to the calculated reactivity corrections. These corrections are very sensitive to the input parameters chosen for the core simulation, and slight mis-estimations of these have large reactivity effects. It is known that if the reactivity noise and the moderator temperature noise could be measured, the MTC could be determined without disturbing

Immediate renal imaging and renography with /sup 99m/Tc methylene diphosphonate to assess renal blood flow, excretory function, and anatomy

International Nuclear Information System (INIS)

Glass, E.C.; DeNardo, G.L.; Hines, H.H.

1980-01-01

/sup 99m/Tc methylene diphosphonate (/sup 99m/Tc MDP) was evaluated as a clinical renal imaging agent in 20 patients referred for bone scintigraphy. Sequential scintigraphy, which was started immediately after injection, yielded blood flow studies of high quality, and subsequent images accurately delineated renal anatomy and excretion in nonazotemic patients. In comparison with delayed images, early images were vastly superior in quality and demonstrated improved target-to-nontarget activity ratios (p < 0.001) and improved lesion detectability (p < 0.01). Renal imaging performed incidental to bone scintigraphy with MDP can be greatly enhanced by initiating sequential scintigraphy immediately after injection

/sup 99m/Tc pertechnetate uptake in the thyroid measured with a scintillation camera: a parameter of thyroid function. [/sup 131/I

Energy Technology Data Exchange (ETDEWEB)

Sokole, E.B.; van der Schoot, J.B.; Alberts, C.

1975-01-01

A /sup 99m/Tc pertechnetate thyroid uptake procedure, using a scintillation camera and a data storage system, is described. After comparison of extrathyroidal activity in several regions below the thyroid, activity in the clavicular regions was preferred for correction of the thyroid uptake measurement. No pertechnetate uptake curve obtained over the initial 15 min after injection was found to be representative of a specific thyroid function, and regional thyroid uptake curves gave only quantitative differences. The 15-min pertechnetate thyroid uptake measurement, with correction for clavicular extrathyroidal activity, correlates well with /sup 131/I uptake and is a good parameter of thyroid function, especially in the distinction of euthyroidism and hyperthyroidism.

MIBI-{sup 99m}Tc mammary scintigraphy; Centellografia mamaria con MIBI-{sup 99m}Tc

Energy Technology Data Exchange (ETDEWEB)

Mayosky, Maria C; Parma, Elvira P; Armesto, Amparo M; Zarlenga, Ana C [Instituto de Oncologia Angel H. Roffo, Buenos Aires (Argentina). Centro Oncologico de Medicina Nuclear; Cresta, Carlos; Azar, Maria E; Noblia, Cristina [Instituto de Oncologia Angel H. Roffo, Buenos Aires (Argentina). Servicio de Mastologia

1999-07-01

121 patients suspected of breast cancer were studied with MIBI-{sup 99m}Tc to evaluate the suitability of the mammary scintigraphy in patients with doubtful cancer diagnosis.The results show 93 % sensitivity and 95 % specificity and indicate the usefulness of this procedure to increase the accuracy of the diagnosis.

Effect of iron deficiency anemia on the biodistribution of {sup 99m}Tc radiopharmaceuticals

Energy Technology Data Exchange (ETDEWEB)

Calmanovici, Gabriela P. [Radioisotopes Laboratory, Physics Department, School of Pharmacy and Biochemistry, University of Buenos Aires, Junin 956 - 1113, Buenos Aires (Argentina); Salgueiro, Maria J. [Radioisotopes Laboratory, Physics Department, School of Pharmacy and Biochemistry, University of Buenos Aires, Junin 956 - 1113, Buenos Aires (Argentina); Janjetic, Mariana A. [Physics Department, School of Pharmacy and Biochemistry, University of Buenos Aires, Junin 956 - 1113, Buenos Aires (Argentina); Leonardi, Natalia M. [Radioisotopes Laboratory, Physics Department, School of Pharmacy and Biochemistry, University of Buenos Aires, Junin 956 - 1113, Buenos Aires (Argentina); Boccio, Jose R. [Physics Department, School of Pharmacy and Biochemistry, University of Buenos Aires, Junin 956 - 1113, Buenos Aires (Argentina); Zubillaga, Marcela B. [Radioisotopes Laboratory, Physics Department, School of Pharmacy and Biochemistry, University of Buenos Aires, Junin 956 - 1113, Buenos Aires (Argentina)]. E-mail: mzubi@ffyb.uba.ar

2006-05-15

The distribution of colloids and labeled cells in organs is influenced by their intrinsic properties and by the state of the investigated subject. Iron deficiency remains an unsolved nutritional problem all over the world; one of its severe consequences is anemia. Because iron metabolism principally takes place in the liver, spleen, bone marrow, skeletal muscle and blood, we studied the effect of iron deficiency anemia on the biodistribution of {sup 99m}Tc phytate, {sup 99m}Tc gelatin colloid and {sup 99m}Tc RBC (red blood cells labeled with {sup 99m}Tc). Our results show that iron deficiency anemia modifies the pattern of biodistribution of the two colloids assayed. However, this behavior is different for both of them. This work contributes to studies that kinetically and statistically establish that iron deficiency anemia induces a significant inversion in the spleen-liver activity relationship when centellographic studies are performed with colloids such as {sup 99m}Tc phytate.

Production of $^{99}$?? and $^{99m}$Tc in the $^{100}$Mo($\\gamma, n$) Photonuclear Reaction at the Electron Accelerator - MT-25 Microtron

CERN Document Server

Sabelnikov, A V; Gustova, M V; Dmitriev, S N

2004-01-01

$^{99}$Mo was obtained in the $^{100}$Mo($\\gamma, n$) reaction at the electron accelerator - MT-25 microtron of the LNR. A foil of $^{\\rm nat}$Mo(9.6{\\%} $^{100}$Mo) and $^{100}$MoO$_{3}$ powder (100{\\%} ^{100}$Mo) were used as targets. The $^{99}$Mo radiation yield under experimental conditions amounted to 3.2 kBq/$\\mu $A$\\cdot $h$\\cdot $mg of $^{100}$Mo. The $^{99m}$Tc isolation from the target material and other radioactive impurities was realized by means of ion exchange. A possibility of use of the $^{99}$Mo/$^{99m}$Tc generator based on molybdenumcarbonyl was investigated. The radioactive impurity content in the final $^{99m}$Tc preparations did not exceed 10$^{-5}$ Bq/Bq.

{sup 99m}Tc generator preparation using (n, {gamma}){sup 99}Mo produced ex-natural molybdenum

Energy Technology Data Exchange (ETDEWEB)

Le, So Van [Nuclear Research Institute, Dalat (Viet Nam)

2003-03-01

Theoretical assessment on the chromatographic {sup 99m}Tc generator preparation using (n, {gamma}) {sup 99}Mo produced ex-natural molybdenum was carried out. The relationship between the neutron flux for MoO{sub 3} target activation, Mo-content or Mo adsorption capacity of column packing material, {sup 99m}Tc pertechnetate concentration and/or {sup 99m}Tc radioactivity of eluate was established. The reasonably lower limit of neutron flux of reactor and Molybdenum content of column packing material were found out to estimate the production of portable chromatographic generators available for nuclear medicine application. The concentration of {sup 99m}Tc pertechnetate eluate of low {sup 99m}Tc concentration using the column elution technique was also evaluate theoretically and conducted successfully in practice. Three options of {sup 99m}Tc generator using Titanium-Molybdate, Zirconium-Molybdate and Zirconium Oxide as generator column-packing materials were prepared and successfully put into use in nuclear medicine application. (author)

A new approach for manufacturing and processing targets to produce 99mTc with cyclotrons

Science.gov (United States)

Matei, L.; McRae, G.; Galea, R.; Niculae, D.; Craciun, L.; Leonte, R.; Surette, G.; Langille, S.; Louis, C. St.; Gelbart, W.; Abeysekera, B.; Johnson, R. R.

2017-06-01

The most important radioisotope for nuclear medicine is 99mTc. After the supply crisis of 99Mo starting in 2008, the availability of 99mTc became a worldwide concern. Alternative methods for producing the medical imaging isotope 99mTc are actively being developed around the world. The reaction 100Mo(p, 2n)99mTc provides a direct route that can be incorporated into routine production in nuclear medicine centers that possess medical cyclotrons for production of other isotopes, such as those used for Positron Emission Tomography. This paper describes a new approach for manufacturing targets for the (p, 2n) nuclear reaction on 100Mo and the foundation for the subsequent commercial separation and purification of the 99mTc produced. Two designs of targets are presented. The targets used to produce 99mTc are subject to a number of operational constraints.They must withstand the temperatures generated by the irradiation, accommodate temperature gradients from cooling system of the target, must be resilient and must be easily post-processed to separate the 99mTc. After irradiation, the separation of Tc from Mo was carried out using an innovative two-step approach. The process described in this paper can be automated with modules that easily fit in standard production hot cells found in nuclear medicine facilities.

Osteomyelitis diagnosis by {sup 99m}Tc radiolabeled aptamers

Energy Technology Data Exchange (ETDEWEB)

Santos, S.R.; Ferreira, I.M.; Andrade, A.S.R., E-mail: sararoberta7@hotmail.com, E-mail: imendesf@yahoo.com.br, E-mail: antero@cdtn.br [Centro de Desenvolvimento da Tecnologia Nuclear (CDTN/CNEN-MG), Belo Horizonte, MG (Brazil); Barros, A.L.B.; Cardoso, V.N.; Diniz, O.F., E-mail: brancodebarros@yahoo.com.br, E-mail: valbertcardoso@yahoo.com.br, E-mail: simoneodilia@yahoo.com.br [Universidade Federal de Minas Gerais (UFMG), Belo Horizonte, MG (Brazil). Faculdade de Farmacia. Departamento de Analises Clinicas e Toxicologicas

2015-07-01

Osteomyelitis, which is characterized by progressive inflammatory destruction and new opposition of bone, is still a difficult infection to treat. The clinical diagnosis in late stages is achieved easily, but an early diagnosis is more challenging. Staphylococcus aureus is a common agent found in osteomyelitis and bone prostheses infection. Diagnosis by scintigraphy has advantages because it is a non-invasive procedure and is able to perform an early diagnosis even before anatomic changes. Thus, nuclear medicine could contribute to an accurate diagnosis since specific radiopharmaceuticals were developed. In this study, aptamers selected to Staphylococcus aureus were labeled with {sup 99m}Tc and used for bacteria identification in an osteomyelitis experimental model. The aptamers selected to S. aureus were directly labelled with {sup 99m}Tc and were evaluated by biodistribution studies. Wistar rats with intraosseous infection in the right paw were used. A random aptamer labelled with {sup 99m}Tc was as control. Six animals were used in each group. The aptamers labeled with {sup 99m}Tc were able to identify the infection foci caused by S. aureus displaying a target/non-target ratio of 2,23 ± 0,20, after 3 h. The control group presented a target/non-target ratio 1,08 ± 0.23. The results indicated that the radiolabeled aptamers were able to identify specifically the infection foci and they should be further explored for infection diagnosis by scintigraphy. (author)

Labelled Preformed liposomes with 99MTC-DTPA, 99 MTC-ECD, 99MTC-MDP and 99MTC-MIBI : Labelling procedures and stability studies

International Nuclear Information System (INIS)

Savio, E.O.; Teran, M.A.; Vales, M.E.; Frier, M.

2004-01-01

Liposomes labelled with gamma e miters like 99mTc, can be used for scintigraphic imaging to non-invasively track and quantify the distribution of liposomes in the body. In vitro studies were done to choose a suitable radiopharmaceutical (RF) to be attached to performed liposomes. 99mTc-Complexes (DTPA, ECD, MDP, MIBI) were used to label collagen liposomes. Commercial kits were labelled with 99mTc04-(TechnoNuclear). Quality controls of the RF were performed. Collagen liposomes suspended in saline 0.9% were incubated at 4.25.37 and 60 for 30 min. Efficiency of the labelling procedure was determined by gel filtration using Sephadex G25 (Pharmacia) and NaC10.9%. Samples of 100mL (74MBq), were seeded and fractions of 0.5mL were colleted and measured in an ionisation chamber (Capintec CRC). Stability of the labelled liposomes was assessed incubating 0.5mL, of the suspension with 1mL of human serum during 30 min at 37 . Dialysis was performed using dialysis bags of 64 K pore size and NaCI 0.9% at room temperature. Samples of the saline bath were collected at 30.60 and 90 min. and measured in a solid scintillation counter Ortec.Liposomes labelled with 99mTc-DTPA and 99mTcMIBI showed a labelling efficiency of 80%; liposomes incubated with 99mTc-MDP were labelled in a 50% and 99mTc-ECD did not bind to liposomes in the conditions of study. Incubation of labelled liposomes with human serum showed 50% of strong binding to the plasmatic proteins for 99mTc-DTPA but low values (5%) for the other specimens. Labelled liposomes were achieved, with different RF, showing a suitable in vitro stability to perform in vivo studies

Cardiac amyloidosis detection with pyrophosphate-99mTc scintigraphy

Energy Technology Data Exchange (ETDEWEB)

Souza, D.S.F.; Ichiki, W.A.; Coura Filho, G.B.; Izaki, M.; Giorgi, M.C.P.; Soares Junior, J; Meneghetti, J.C. [Universidade de Sao Paulo (FM/USP), SP (Brazil). Fac. de Medicina. Instituto do Coracao. Servico de Medicina Nuclear e Imagem Molecular

2008-07-01

Full text: Introduction: Amyloidosis is a rare disease, characterized by extracellular deposition of insoluble amyloid fibrils in organs and tissues. It may affect virtually any system, preferably heart, kidneys and liver. The cardiac involvement produces a spectrum of clinical features, usually with progressive dysfunction. Early diagnosis is important for institution of appropriate therapy. Case report: Male patient, 75 years old, with diagnosed congestive heart failure functional class III and Mobitz II second-degree atrial-ventricular block, was hospitalized for implantation of definitive cardiac pacemaker. Patient mentioned history of worsening effort dyspnoea over a one-month period, progressing to minimum effort, orthopnea, paroxysmal nocturnal dyspnoea and paroxysms of dry cough, and swelling of lower limbs. Echocardiography showed diffuse hypertrophy of left ventricle (LV), with systolic dysfunction due to diffuse hypokinesia and hyperrefringent aspect in the septum. It was questioned a cardiac infiltrating process. Cardiac amyloidosis was considered as a diagnostic hypothesis. The patient underwent a pyrophosphate-{sup 99m}Tc scintigraphy, which showed abnormal tracer uptake in the heart projection, with diffuse pattern on the left ventricle walls, compatible with the clinical suspicion cardiac amyloidosis, which was later confirmed by endomyocardial biopsy. Discussion: In this case report, the patient had clinical and other auxiliary examinations, such as electrocardiography and Doppler echocardiography, compatible with cardiac amyloidosis, which led to implementation with pyrophosphate-{sup 99m}Tc scintigraphy and later endomyocardial biopsy. Cardiac amyloidosis occurs in about half the cases of primary amyloidosis (AL) and is rare in secondary amyloidosis (AA). Its clinical presentation is polymorphic and it can be classified into four distinctive types: restrictive cardiomyopathy, systolic dysfunction, postural hypotension and conduction disorders

Confirmation of hydrazone formation in HYNIC-peptide conjugate preparation, and its hydrolysis during labeling with {sup 99m}Tc

Energy Technology Data Exchange (ETDEWEB)

Gandomkar, M. [Radioisotope Division, Nuclear Research Center, Atomic Energy Organization of Iran (AEOI), Tehran (Iran, Islamic Republic of)]. E-mail: msgandomkar@yahoo.com; Najafi, R. [Radioisotope Division, Nuclear Research Center, Atomic Energy Organization of Iran (AEOI), Tehran (Iran, Islamic Republic of); Shafiei, M. [Radioisotope Division, Nuclear Research Center, Atomic Energy Organization of Iran (AEOI), Tehran (Iran, Islamic Republic of); Ebrahimi, S.E.S. [Department of Medicinal Chemistry, Faculty of Pharmacy, Tehran University of Medical Sciences, Tehran (Iran, Islamic Republic of)

2007-07-15

Because of its monodenticity, 6-hydrazinopyridine-3-carboxylic acid (HYNIC) is of interest as a bifunctional chelator for labeling peptide with {sup 99m}Tc. Here, we confirm the formation of hydrazone in HYNIC-conjugated peptide. The preparative HPLC was used to purify the HYNIC conjugated somatostatin-based peptide and the result showed two peaks, even after two consecutive purifications. Analysis of these peaks by mass spectrometry indicated the presence of hydrazone, produced during preparation conjugate. Further, we have shown that presence of hydrazone really does not matter because under {sup 99m}Tc-labeling conditions, hydrazone is hydrolyzed back to HYNIC that then chelates {sup 99m}Tc. A HYNIC-peptide conjugate freeze-dried kit was also prepared in a mildly acidic or neutral condition with a final pH of 6-7. The kit was then labeled by {sup 99m}Tc and incubated in 100 dec. C for 10 min, and a labeling yield of >95% was obtained.

Current Outlook for 99mTc Distribution Based on Electron Accelerator Production

International Nuclear Information System (INIS)

Benjamin L. Nelson; W. David Bence; John R. Snyder

2007-01-01

In 1999 a practical example illustrating the economical and reliable production of 99mTc from an accelerator was developed. It included the realistic costs involved in establishing and operating the accelerator facility and the distribution of the 99mTc to regions in Florida. However, the technology was never commercialized. Recent political and economic developments prompted this second look at accelerator produced 99mTc. The practicality of this system in 2007 dollars was established to account for inflation and current demand. The same distribution model and production schedule from the Global 1999 study were used. Numbers were found using current rates and costs where possible and indexed estimations when necessary. Though several of the costs increased significantly and the sale price remains at approximately 35 cents/mCi, the unit cost of 99mTc throughput only increased from 12.8 cents/mCi to 15.0 cents/mCi or approximately 17.2% from 1999 to 2007 thus continuing to be economically viable. This study provides ground work for creating business development models at additional locations within the U.S

NTS1-R-targeted diagnostic imaging of malignant tumors with 99mTc labeled neurotensin analogues

International Nuclear Information System (INIS)

Nikolopoulou, A.; Nock, B.; Maina, T.; Galanis, A.; Cordopatis, P.

2004-01-01

Full text: Recent studies, based on receptor radio autoradiography methods in human biopsy specimens, have demonstrated the expression of neurotensin receptors of subtype 1 (NTSI-R) at a high density in primary human cancers, such as in ductal exocrine pancreatic carcinoma, Ewing's sarcoma and meningioma. This finding provides the molecular basis for the scintigraphic detection of NTS1-R-positive tumors in patients using radiolabeled NT analogues in combination with SPECT. We synthesized two novel NT analogues based on the NT (8-13) peptide sequence - essential for interaction with the NTS1-R - and modified at the N-terminal by a covalently attached open chain tetraamine chelator for stable binding of the radionuclide. In this work, a comparative study of the new compounds in cells and animal models is presented and their suitability in the NTS1-R- targeted diagnostic imaging of malignant tumors is discussed. In particular, the tetra-amine functional analogues NT1: [N4- (a) Ala0, Dab9] NT (8-13) and NT2: [N4- (a) Ala0, Dab9, Tle12] NT (8-13) were synthesized by SPPS techniques applying Fmoc/Boc protection strategies. The ES-MS spectra of the chromatographically purified products were consistent with the expected formulae. Incorporation of the radiometal (99mTc) by the open chain tetraamine framework proceeded different at room temperature in alkaline aqueous medium using SnCl2 as reducing agent in the presence of citrate. Under the above mild conditions labelling was nearly quantitative leading to single radiopeptide species of high specific activity. During competition binding assays in human colon adenocarcinoma WiDr cell membranes, using [125I-Tyr3] NT as the radioligand, both peptide conjugates demonstrated high affinity binding to the NTS1-R with IC50s 30 and 80 pM, respectively (IC50 for native NT= 0.20 nM). Both radiopeptides showed a rapid and NTS1-R-mediated migration into the intracellular compartment of the same cells reaching a 95% internalization

Isolation and labelling of human leucocytes with sup(99m)Tc

International Nuclear Information System (INIS)

Kalbaek, H.

1986-01-01

The role of the leucocyte isolation procedure on cell labeling with sup(99m)Tc has been evaluated. Separation of leucocytes was performed by two procedures: (1) sedimentation on methyl cellulose, followed by discontinuous gradient centrifugation; (2) methyl cellulose sedimentation and hypotonic haemolysis of residual red blood cells. After washing the cells in saline and incubation with a stannous pyrophosphate agent, the leucocytes were labelled with 5-10 mCi sup(99m)Tc. Procedure 1 gave a higher purity but lower recovery of polymorphonuclear leucocytes, and a minor contamination of red blood cells. sup(99m)Tc labelling of cells was slightly more efficient with this method, probably due to the presence of red blood cells. Procedure 1 is recommended for in vitro studies on cell kinetics and procedure 2 is recommended for clinical use. (orig.)

Radiation damage to mouse testis cells from [/sup 99m/Tc] pertechnetate

International Nuclear Information System (INIS)

Mian, T.A.; Suzuki, N.; Glenn, H.J.; Haynie, T.P.; Meistrich, M.L.

1977-01-01

The radiation dose and the biologic damage to mouse testis from intravenously administered [/sup 99m/Tc] pertechnetate were studied. The dose was measured for penetrating radiations from /sup 99m/Tc, using calibrated thermoluminescent dosimeters and calculations from the uptake of the nuclide in the testis, and was found to be 4.9 rads per mCi of 99 Tc. The biologic damage was measured by the decrease in the number of sperm heads in the testis, counted both by hemacytometer and by Coulter counter. In preliminary experiments using external gamma radiation from 137 Cs, the number of sperm heads reached a minimum 29 days after irradiation. Twenty-nine days after injection of 5.8 mCi of /sup 99m/Tc, which gives 28 rads to the testis, the number of sperm heads decreased to 70% of control. The biologic effect corresponds to that seen after 40 rads of gamma radiation from 137 Cs. The damage to mouse testis cells from internally administered /sup 99m/Tc as measured in an in vivo system appears to be at least as significant as that from external gamma irradiation, if not more so

OFDM with Index Modulation for Asynchronous mMTC Networks.

Science.gov (United States)

Doğan, Seda; Tusha, Armed; Arslan, Hüseyin

2018-04-21

One of the critical missions for next-generation wireless communication systems is to fulfill the high demand for massive Machine-Type Communications (mMTC). In mMTC systems, a sporadic transmission is performed between machine users and base station (BS). Lack of coordination between the users and BS in time destroys orthogonality between the subcarriers, and causes inter-carrier interference (ICI). Therefore, providing services to asynchronous massive machine users is a major challenge for Orthogonal Frequency Division Multiplexing (OFDM). In this study, OFDM with index modulation (OFDM-IM) is proposed as an eligible solution to alleviate ICI caused by asynchronous transmission in uncoordinated mMTC networks. In OFDM-IM, data transmission is performed not only by modulated subcarriers but also by the indices of active subcarriers. Unlike classical OFDM, fractional subcarrier activation leads to less ICI in OFDM-IM technology. A novel subcarrier mapping scheme (SMS) named as Inner Subcarrier Activation is proposed to further alleviate adjacent user interference in asynchronous OFDM-IM-based systems. ISA reduces inter-user interference since it gives more activation priority to inner subcarriers compared with the existing SMS-s. The superiority of the proposed SMS is shown through both theoretical analysis and computer-based simulations in comparison to existing mapping schemes for asynchronous systems.

Engineer Research and Development Center's Materials Testing Center (MTC)

Data.gov (United States)

Federal Laboratory Consortium — The Engineer Research and Development Center's Materials Testing Center (MTC) is committed to quality testing and inspection services that are delivered on time and...

Development and utilization of the inorganic polymer materials for {sup 99}Mo-{sup 99m}Tc and {sup 188}W-{sup 188}Re generator based on (n, gamma) method

Energy Technology Data Exchange (ETDEWEB)

Yoshida, Kosuke; Ishikawa, Koji; Terunuma, Hitoshi; Hasegawa, Yoshio; Tatenuma, Katsuyoshi [KAKEN Co., Mito, Ibaraki (Japan)

2003-03-01

A molybdenum (Mo) adsorbent called PZC (Poly Zirconium Compound) with high efficiency of Mo adsorption has been developed in order to generate {sup 99m}Tc from {sup 99}Mo produced from natural Mo by (n, gamma) method. The {sup 99m}Tc generator using PZC has cleared mostly the technical subjects. By the results of many experiments, cold and hot test with {sup 99}Mo activity from low level (10{sup 5} Bq) to high level (10{sup 10} Bq), it has been confirmed that the PZC method can be practically applied for the (n, gamma) {sup 99}Mo-{sup 99m}Tc generator. From the reasons that PZC has the ability and many merits such as high adsorption capacity (>250 mg-Mo/g-PZC) of Mo, high elution yield (av. 80%) of {sup 99m}Tc, the low breakthrough (<0.05 kBq-{sup 99m}Mo/MBq-{sup 99m}Tc) of {sup 99}Mo and others, the current (n, fission) {sup 99m}Tc generator utilizing {sup 99}Mo produced from enriched uranium will be taken the place by PZC method. In this paper, the practicability of PZC and a newly developed functional material PTC(Poly Titanium Compound) as the (n, gamma) {sup 99}Mo-{sup 99m}Tc generator, and an ability of PZC as the {sup 188}W-{sup 188}Re generator will be shown. (author)

Effects of concurrent drug therapy on technetium /sup 99m/Tc gluceptate biodistribution

International Nuclear Information System (INIS)

Hinkle, G.H.; Basmadjian, G.P.; Peek, C.; Barker, K.K.; Ice, R.D.

1982-01-01

Drug interactions with /sup 99m/Tc gluceptate resulting in altered biodistribution were studied using chart review and animal tests. Charts of nine patients who had abnormal gallbladder uptake of technetium /sup 99m/Tc gluceptate during a two-year period were reviewed to obtain data such as concurrent drug therapy, primary diagnosis, and laboratory values. Adult New Zealand white rabbits were then used for testing the biodistribution of technetium /sup 99m/Tc gluceptate when administered concurrently with possibly interacting drugs identified in the chart review--penicillamine, penicillin G potassium, penicillin V potassium, acetaminophen, and trimethoprim-sulfamethoxazole. Chart review revealed no conclusive patterns of altered biodistribution associated with other factors. The data did suggest the possibility that the five drugs listed above might cause increased hepatobiliary clearance of the radiopharmaceutical. Animal tests showed that i.v. penicillamine caused substantial distribution of radioactivity into the gallbladder and small bowel. Minimally increased gallbladder radioactivity occurred when oral acetaminophen and trimethoprim-sulfamethoxazole were administered concurrently. Oral and i.v. penicillins did not increase gallbladder activity. Penicillamine may cause substantial alteration of the biodistribution of technetium /sup 99m/Tc gluceptate

Balloon-based adjuvant radiotherapy in breast cancer: comparison between 99mTc and HDR 192Ir

Directory of Open Access Journals (Sweden)

Tarcísio Passos Ribeiro de Campos

2016-04-01

Full Text Available Abstract Objective: To perform a comparative dosimetric analysis, based on computer simulations, of temporary balloon implants with 99mTc and balloon brachytherapy with high-dose-rate (HDR 192Ir, as boosts to radiotherapy. We hypothesized that the two techniques would produce equivalent doses under pre-established conditions of activity and exposure time. Materials and Methods: Simulations of implants with 99mTc-filled and HDR 192Ir-filled balloons were performed with the Siscodes/MCNP5, modeling in voxels a magnetic resonance imaging set related to a young female. Spatial dose rate distributions were determined. In the dosimetric analysis of the protocols, the exposure time and the level of activity required were specified. Results: The 99mTc balloon presented a weighted dose rate in the tumor bed of 0.428 cGy.h-1.mCi-1 and 0.190 cGyh-1.mCi-1 at the balloon surface and at 8-10 mm from the surface, respectively, compared with 0.499 and 0.150 cGyh-1.mCi-1, respectively, for the HDR 192Ir balloon. An exposure time of 24 hours was required for the 99mTc balloon to produce a boost of 10.14 Gy with 1.0 Ci, whereas only 24 minutes with 10.0 Ci segments were required for the HDR 192Ir balloon to produce a boost of 5.14 Gy at the same reference point, or 10.28 Gy in two 24-minutes fractions. Conclusion: Temporary 99mTc balloon implantation is an attractive option for adjuvant radiotherapy in breast cancer, because of its availability, economic viability, and similar dosimetry in comparison with the use of HDR 192Ir balloon implantation, which is the current standard in clinical practice.

/sup 99m/Tc labeling of antibodies to cardiac myosin Fab and to human fibrinogen

International Nuclear Information System (INIS)

Khaw, B.A.; Strauss, H.W.; Carvalho, A.; Locke, E.; Gold, H.K.; Haber, E.

1982-01-01

We have developed a method of labeling biologically active labile macromolecules, such as human fibrinogen (HF) and anticardiac-myosin Fab (AM-Fab), with /sup 99m/Tc at neutral pH. This method uses dithionite reduction of pertechnetate and subsequent labeling, to test the method with acid-labile macromolecules. Complexes of diethylene triamine pentaacetic acid with macromolecules such as human fibrinogen (D-HF) and anticardiac-myosin Fab (D-AM-Fab) were labeled and utilized in in vitro and in vivo studies. In biodistribution studies, the /sup 99m/Tc D-HF had a two-component blood clearance (half-times 1 hr and 15 hr) and was 80--88% coagulable. The /sup 99m/Tc AM-Fab retained its immunoreactivity as tested by affinity chromatography; also during in vivo localization in experimental myocardial infarction. This labeling technique provides an easy and efficient approach to the /sup 99m/Tc labeling of other biologically active and acid-labile macromolecules

The separation of sup(99m)Tc from 99Mo through an aluminium oxide chromatographic columm

International Nuclear Information System (INIS)

Imoto, S.T.

1980-01-01

The separation of sup(99m)Tc from 99 Mo using the chromatographic method is studied. Alumina is used as adsorbent. The pH values for adsorption of carrier-free 99 Mo on columns filled with ordinary alumina and with that thermically treated at 1000 0 C for five hours, and the separation conditions of sup(99m)Tc using physiologic solution as eluent are determined. The sup(99m)Tc separation yields of both columns are compared and the quality of the products obtained by successive elutions for 10 days is analyzed. (Author) [pt

Magnesium-Molybate Compounds as Matrix for 99Mo/99mTc Generators

Directory of Open Access Journals (Sweden)

Fabiola Monroy-Guzman

2011-01-01

Full Text Available This work reports the preparation of a 99mTc generator based on conversion of 99Mo produced by neutron irradiation, into insoluble magnesium 99Mo-molybdates compounds as matrix. The effect of magnesium salt types and concentration, Mg:Mo molar ratios, pH of molybdate solutions, eluate volume as well as the addition order of molybdate and magnesium solutions’ influences on the final 99mTc were evaluated. Polymetalates and polymolybdates salts either crystallized or amorphous were obtained depending on the magnesium salt and Mg:Mo molar ratio used in matrix preparation. 99Mo/99mTc generator production based on magnesium-99Mo molybdate compounds allow reduction of preparation time and eliminates the use of specialized installations. The best generator performances were attained using matrices prepared from 0.1 mol/L MgCl2·6H2O solutions, ammonium molybdate solutions at pH 7 and at a Mg:Mo molar ratio of 1:1.

Electrolytic preparation of sup(99m)Tc human serum albumin using tin electrodes

International Nuclear Information System (INIS)

Narasimhan, D.V.S.; Mani, R.S.

1975-01-01

A method for labelling human serum albumin [HSA] with sup(99m)Tc using electrolytically generated Sn/II/ ions has been developed. The procedure uses Sn electrodes for electrolysis and gives high labelling yields. The amount of Sn released into the final product was found to be much less than the reported toxic levels. A ready-to-use kit for obtaining sterile sup(99m)Tc HSA is described. Tin metal wires sealed in aluminium were irradiated in a CIRUS reactor at a neutron flux of 7.5x10 12 n cm -2 sec -1 for one month. The 113 Sn produced in the wire was used for tracer studies with the electrolitically labelled HSA. sup(99m)Tc in the form sodium pertechnetate in 0.9% NaCl was obtained by methyl ethyl ketone extraction from alkaline solutions of neutron irradiated 99 Mo [specific activity 50-200 mCi/g] in the solvent extraction generator developed at Isotope Division, BARC. Radiochemical purity analysis of sup(99m)Tc labelled HSA prepared by the above procedure was carried out by ascending paper chromatography on Whatman No.1 paper, and 85% methanol and 0.9% sodium chloride as solvents. (F.Gy.)

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.)

Investigations on the structures of sup(99m)Tc and 113Sn pyrophosphate complexes and of sup(99m)Tc and 113Sn ethane hydroxy diphosphate complexes

International Nuclear Information System (INIS)

Hohloch, M.

1980-01-01

The complex formation of double labelling of bivalent 113 Sn and reduced, quadrovalent sup(99m)Tc with pyrophosphate (PPi) or ethane hydroxy diphosphorate (EHDP) has been investigated by means of in vivo distribution in the rat. The molar rates of sup(99m)Tc and 113 Sn to PPi resp. EHDP, as well as the pH-value and the initial concentration is varied. Furthermore, both elements were oxidized with H 2 O 2 in the alkaline medium. Four typical sup(99m)Tc and two typical 113 Sn in-vivo distribution patterns can be differentiated: 1. Pertechnetate, characterized by a strong enrichment in the stomach, forms when all Sn-II has been oxidized to Sn-IV in the preparation. 2. One bone-seeking 113 Sn-II PPi (EHDP) complex and a sup(99m)Tc-IV PPi (EHDP) complex each, which are formed at least equimolar ratio of Sn to PPi (EHDP) and suffiently high concentration of PPi (EHDP) in the physiological pH-value. 3. A non-bone-seeking sup(99m)Tc-IV compound, which is enriched in the kidneys instead, is formed in the weakly alkaline medium or at low PPi (EHDP) concentration. This is probably monomeric technetium dioxide dihydrate. 4. A sup(99m)Tc as well as a Sn colloid is formed at deficient ligand concentration (PPi or EHDP to Sn). The chemical composition of the complexes is discussed the possible reaction courses are illustrated in the following diagrams. (orig./MG) [de

Comparative evaluation of 123I and /sup 99m/Tc for thyroid studies

International Nuclear Information System (INIS)

Atkins, H.L.; Ansari, A.N.; Bradley-Moore, P.R.; Lambrecht, R.; Wolf, A.

1975-01-01

Both /sup 99m/Tc and 123 I can be used to advantage in assessing thyroid function and anatomy. The nuclides have similar principal gamma photons, and their short physical half-lives result in low radiation dose, thus allowing administration of large quantities of activity. The very early uptakes of these radionuclides by the thyroid do not bear a consistent relationship, and that requires further study. The clinical value of 123 I depends ultimately on its consistent availability at reasonable cost

Follow-up of a case of subacute thyroiditis with uncommon thyroid {sup 99m}Tc uptake

Energy Technology Data Exchange (ETDEWEB)

Zhang, Zhe; Li, Chengjiang, E-mail: 10518093zz@163.com [Medical College of Zhejiang University, Hangzhou (China). Hospital of Medical College. Department of Endocrinology and Metabolism

2013-07-01

Thyroidal 99mTc uptake in the acute thyrotoxic phase of subacute thyroiditis (SAT) is always inhibited. However, a patient with SAT had signs in the right-side thyroid gland with transient thyrotoxicosis and slightly high 99mTc uptake levels in the right lobe, low 99mTc uptake in the left lobe, and normal overall uptake. Histological examination showed cellular destruction and granulomatous inflammatory changes in the right lobe, with marked interstitial fibrosis in the left lobe. The patient was thyrotrophin-receptor antibody (TRAb) positive. After a short course of prednisolone, SAT-like symptoms and signs improved. TRAb-positivity resolved spontaneously after 22 months, and TSH levels were slightly low for 22 months. Levels then kept normal in the following four years. In conclusion, high 99mTc uptake by the right lobe was due to the combined effects of TRAb and left thyroid gland fibrosis. (author)

Localization of the acute lower gastrointestinal hemorrhage in vivo-in vitro labeling of red blood cells with sup(99m)Tc

International Nuclear Information System (INIS)

Noguera, E.; Mothe, G.; Wyse, E.

1984-01-01

For the detection and localization of acute lower gastrointestinal hemorrhage in vivo-in vitro labeling of red blood cells with sup(99m)Tc and sup(99m)Tc sulfur colloid has been sugested. The procedure for labeling RBC with sup(99m)Tc consisted in injecting IV 1 mg of ClSn; 20 minutes after injection of tin 10 cc of blood were withdrawn in a syringe containing 20 mCi of sup(99m)Tc; this was incubated for 10 minutes and then injected IV. Scintigraphy of the abdominal cavity was done in supine position and performed with a large field gamma camera with a parallel hole-low energy colimator. Computer adquisition of images was started 5 minutes after RBC injection and made at the rate of one enery 5 minutes for 45 minutes. 14 patients were studied divided in: a) control: 6 patients. b) with active gastrointestinal hemorrhage: 4 patients had positive scintigraphy. The hemorrhage was documented with superior mesenteric arteriography, endoscopy and/or necropsy. The sensitivity was 100%. In 4 out of 14 patients scintigraphy with sup(99m)Tc RBC compared with simultaneous sup(99m)Tc sulfur colloid demonstrated that all patients with positive sup(99m)Tc RBC had also positive sup(99m)Tc sulfur colloid scintigraphy. c) without active gastrointestinal hemorrhage: all of them had negative scintigraphy (specificity 100%). Abdominal scintigraphy with sup(99m)Tc RBC or sulfur colloid are both sensitive for detection and localization of lower gastrointestinal bleeding and the negative study suggests the absence of active hemorrhage. It is suggested that the sup(99m)Tc sulfur colloid scintigraphy should be the initial procedure to study these patients and abdominal arteriography should be performed only in patients with positive abdominal scintigraphy. (M.E.L.) [es

Separation of sup(99m)Tc from 99Mo through a hydrous zirconium oxide column

International Nuclear Information System (INIS)

Mengatti, J.

1980-01-01

The preparation of 99 Mo-,sup(99m)Tc generator based on the adsorption of 99 Mo on hydrous zirconium oxide column, employing the in exchange technique, is described. The adsorption of 99 Mo on hydrous zirconium oxide (HZO) and the separation of sup(99m)Tc, generated by the decay of 99 Mo with saline solution, are analised. The sup(99m)Tc separation yield, pH of the eluted solution, aspect of the elution curve and the adsorption of 99 Mo on hydrous zirconium oxide calcined at 800 0 C are studied. The chemical and radioactive purities of the final product are analysed and the variation of the elution yield for successive elutions is studied. (Author) [pt

UPPGHA: Uniform Privacy Preservation Group Handover Authentication Mechanism for mMTC in LTE-A Networks

Directory of Open Access Journals (Sweden)

Jin Cao

2018-01-01

Full Text Available Machine Type Communication (MTC, as one of the most important wireless communication technologies in the future wireless communication, has become the new business growth point of mobile communication network. It is a key point to achieve seamless handovers within Evolved-Universal Terrestrial Radio Access Network (E-UTRAN for massive MTC (mMTC devices in order to support mobility in the Long Term Evolution-Advanced (LTE-A networks. When mMTC devices simultaneously roam from a base station to a new base station, the current handover mechanisms suggested by the Third-Generation Partnership Project (3GPP require several handover signaling interactions, which could cause the signaling load over the access network and the core network. Besides, several distinct handover procedures are proposed for different mobility scenarios, which will increase the system complexity. In this paper, we propose a simple and secure uniform group-based handover authentication scheme for mMTC devices based on the multisignature and aggregate message authentication code (AMAC techniques, which is to fit in with all of the mobility scenarios in the LTE-A networks. Compared with the current 3GPP standards, our scheme can achieve a simple authentication process with robust security protection including privacy preservation and thus avoid signaling congestion. The correctness of the proposed group handover authentication protocol is formally proved in the Canetti-Krawczyk (CK model and verified based on the AVISPA and SPAN.

Mean temperature of the catch (MTC in the Greek Seas based on landings and survey data

Directory of Open Access Journals (Sweden)

Athanassios C. Tsikliras

2015-04-01

Full Text Available The mean temperature of the catch (MTC, which is the average inferred temperature preference of the exploited species weighted by their annual catch, is an index that has been used for evaluating the effect of sea warming on marine ecosystems. In the present work, we examined the effect of sea surface temperature on the catch composition of the Greek Seas using the MTC applied on the official catch statistics (landings for the period 1970-2010 (Aegean and Ionian Seas and on experimental bottom trawl survey data for 1997-2014 (southern Aegean Sea. The MTC of the landings for the study period increased from 11.8 οC to 16.2 οC in the Aegean Sea and from 10.0 οC to 14.7 οC in the Ionian Sea. Overall, the rate of MTC increase was 1.01 οC per decade for the Aegean and 1.17 οC per decade for the Ionian Sea and was positively related to sea surface temperature anomalies in both areas. For the survey data, the increase of the MTC of the bottom trawl catch in the southern Aegean Sea was lower (0.51 οC per decade but referred to a shorter time frame and included only demersal species. The change in MTC of official and survey catches indicates that the relative catch proportions of species preferring warmer waters and those preferring colder waters have changed in favour of the former and that this change is linked to sea surface temperature increase, both internally (through the Atlantic Multidecadal Oscillation or externally (warming trend driven.

Development of a noise-based method for the determination of the moderator temperature coefficient of reactivity (MTC) in pressurized water reactors (PWRs)

International Nuclear Information System (INIS)

Demaziere, C.

2002-01-01

The Moderator Temperature Coefficient of reactivity (MTC) is an important safety parameter of Pressurized Water Reactors (PWRs). In most countries, the so-called at-power MTC has to be measured a few months before the reactor outage, in order to determine if the MTC will not become too negative. Usually, the at-power MTC is determined by inducing a change in the moderator temperature, which has to be compensated for by other means, such as a change in the boron concentration. An MTC measurement using the boron dilution method is analysed in this thesis. It is demonstrated that the uncertainty of such a measurement technique is so large, that the measured MTC could become more negative than what the Technical Specifications allow. Furthermore, this technique incurs a disturbance of the plant operation. For this reason, another technique relying on noise analysis was proposed a few years ago. In this technique, the MTC is inferred from the neutron noise measured inside the core and the moderator temperature noise measured at the core-exit, in the same or in a neighbouring fuel assembly. This technique does not require any perturbation of the reactor operation, but was nevertheless proven to underestimate the MTC by a factor of 2 to 5. In this thesis, it is shown, both theoretically and experimentally, that the reason of the MTC underestimation by noise analysis is the radially loosely coupled character of the moderator temperature noise throughout the core. A new MTC noise estimator, accounting for this radially non-homogeneous moderator temperature noise is proposed and demonstrated to give the correct MTC value. This new MTC noise estimator relies on the neutron noise measured in a single point of the reactor and the radially averaged moderator temperature noise measured inside the core. In the case of the Ringhals-2 PWR in Sweden, Gamma-Thermometers (GTs) offer such a possibility since in dynamic mode they measure the moderator temperature noise, whereas in static

The accumulation, retention and distribution of {sup 95m}Tc in crab (Cancer pagurus L.) and lobster (Homarus gammarus L.). A comparative study

Energy Technology Data Exchange (ETDEWEB)

Smith, D L; Knowles, J F; Winpenny, K [The Centre for Environment, Fisheries and Aquaculture Science, Lowestoft Laboratory, Pakefield Road, Lowestoft, Suffolk (United Kingdom)

1988-08-01

The accumulation, retention and distribution of {sup 95m}Tc has been compared in lobsters and edible crabs kept under identical experimental conditions. The steady-state concentration factor (C{sub ss}) for the uptake of {sup 95m}Tc from seawater was significantly greater for female crabs (C{sub ss}=17{center_dot}9) than for males (C{sub ss}=14{center_dot}4), whereas in lobsters there was no such sex difference and the C{sub ss} of 1161 was much greater than in crabs. The uptake of technetium from food (as indicated by whole body counts) was only moderately greater in lobsters than crabs. Retention of {sup 95m}Tc was similar for crabs and lobsters of both sexes but the clearance rate was greater after the nuclide had been taken up from seawater (t{sub b1/2}=51 days) than from food (t{sub b1/2}=108 days). In all crabs and most male lobsters {sup 95m}Tc was predominantly in the hepatopancreas while in a few male and all female lobsters it was mainly in muscle. Lobster ovaries consistently contained more activity than testes but this difference was not seen in crabs. In hepatopancreas cells of both species {sup 95m}Tc occurred mainly in the cytosol and some initial steps were taken to determine the relationship between technetium and cytosol proteins. The results for crab and lobster are compared with those from previous studies on these and other crustacean species. The possible basis for the much higher concentrations of technetium in lobsters than crabs is discussed and further research suggested. (Copyright (c) 1988 Elsevier Science B.V., Amsterdam. All rights reserved.)

Photo-production of (99)Mo/(99m)Tc with electron linear accelerator beam.

Science.gov (United States)

Avagyan, R; Avetisyan, A; Kerobyan, I; Dallakyan, R

2014-09-01

We report on the development of a relatively new method for the production of (99)Mo/(99m)Tc. The method involves the irradiation of natural molybdenum using high-intensity bremsstrahlung photons from the electron beam of the LUE50 linear electron accelerator located at the Yerevan Physics Institute (YerPhi). The production method has been developed and shown to be successful. The linear electron accelerator at YerPhi was upgraded to allow for significant increases of the beam intensity and spatial density. The LUE50 was also instrumented by a remote control system for ease of operation. We have developed and tested the (99m)Tc extraction from the irradiation of natural MoO3. This paper reports on the optimal conditions of our method of (99)Mo production. We show the success of this method with the production and separation of the first usable amounts of (99m)Tc. Copyright © 2014 Elsevier Inc. All rights reserved.

Technetium 99mTc Pertechnetate Brain Scanning

International Nuclear Information System (INIS)

Rhee, Sang Min; Park, Jin Yung; Lee, Ahn Ki; Chung, Choo Il; Hong, Chang Gi; Rhee, Chong Heon; Koh, Chang Soon

1968-01-01

Technetium 99 mTc pertechnetate brain scanning were performed in 3 cases of head injury (2 chronic subdural hematomas and 1 acute epidural hematoma), 2 cases of brain abscess and 1 case of intracerebral hematoma associated with arteriovenous anomaly. In all the cases brain scintigrams showed 'hot areas.' Literatures on radioisotope scanning of intracranial lesions were briefly reviewed. With the improvement of radioisotope scanner and development of new radiopharmaceuticals brain scanning became a safe and useful screening test for diagnosis of intracranial lesions. Brain scanning can be easily performed even to a moribund patient without any discomfort and risk to the patient which are associated with cerebral angiography or pneumoencephalography. Brain scanning has been useful in diagnosis of brain tumor, brain abscess, subdural hematoma, and cerebral vascular diseases. In 80 to 90% of brain tumors positive scintigrams can be expected. Early studies were done with 203 Hg-Neohydrin or 131 I-serum albumin. With these agents, however, patients receive rather much radiation to the whole body and kidneys. In 1965 Harper introduced 99 mTc to reduce radiation dose to the patient and improve statistical variation in isotope scanning.

Balloon-based adjuvant radiotherapy in breast cancer: comparison between {sup 99m}Tc and HDR {sup 192}Ir

Energy Technology Data Exchange (ETDEWEB)

Campos, Tarcisio Passos Ribeiro de; Lima, Carla Flavia de; Cuperschmid, Ethel Mizrahy, E-mail: tprcampos@pq.cnpq.br [Universidade Federal de Minas Gerais (UFMG), Belo Horizonte, MG (Brazil)

2016-03-15

Objective: To perform a comparative dosimetric analysis, based on computer simulations, of temporary balloon implants with {sup 99m}Tc and balloon brachytherapy with high-dose-rate (HDR) {sup 192}Ir, as boosts to radiotherapy. We hypothesized that the two techniques would produce equivalent doses under pre-established conditions of activity and exposure time. Materials and methods: simulations of implants with {sup 99m}Tc-filled and HDR {sup 192}Ir-filled balloons were performed with the Siscodes/MCNP5, modeling in voxels a magnetic resonance imaging set related to a young female. Spatial dose rate distributions were determined. In the dosimetric analysis of the protocols, the exposure time and the level of activity required were specified. Results: the {sup 99m}Tc balloon presented a weighted dose rate in the tumor bed of 0.428 cGy.h{sup -1}.mCi{sup -1} and 0.190 cGyh{sup -1} at the balloon surface and at 8-10 mm from the surface, respectively, compared with 0.499 and 0.150 cGyh{sup -1}.mCi{sup -1}, respectively, for the HDR {sup 192}Ir balloon. An exposure time of 24 hours was required for the {sup 99m}Tc balloon to produce a boost of 10.14 Gy with 1.0 Ci, whereas only 24 minutes with 10.0 Ci segments were required for the HDR {sup 192}Ir balloon to produce a boost of 5.14 Gy at the same reference point, or 10.28 Gy in two 24-minutes fractions. Conclusion: temporary {sup 99m}Tc balloon implantation is an attractive option for adjuvant radiotherapy in breast cancer, because of its availability, economic viability, and similar dosimetry in comparison with the use of HDR {sup 192}Ir balloon implantation, which is the current standard in clinical practice. (author)

A {sup 99m}Tc Generator using PZC for (n,{gamma}) {sup 99}Mo

Energy Technology Data Exchange (ETDEWEB)

Adang, H G; Mutalib, A; Suparman, I; Hamid,; Purwadi, B; Pancoko, M; Setiowati, S; Yulianti, V; Robertus, D H [Radioisotope Production Center, National Atomic Energy Agency Kawasan PUSPIPTEK, Serpong (Indonesia)

1998-10-01

The high performance adsorbent Poly Zirconium Compound (PZC) was produced by Department of Radioisotope, Japan Atomic Energy Research Institute. This compound was developed as an adsorbent for natural Mo (n,{gamma}) {sup 99}Mo-{sup 99m}Tc Generator. In the present paper, we report the performance of the PZC for a {sup 99m}Tc Generator which was focused on the yield, on elution profile and {sup 99}Mo breakthrough. (author)

Study of the elution {sup 99}Mo-{sup 99m}Tc generators produced at IPEN-CNEN/SP

Energy Technology Data Exchange (ETDEWEB)

Lopes, Paula Regina Corain [Pontificia Univ. Catolica de Sao Paulo, SP (Brazil); Instituto de Pesquisas Energeticas e Nucleares IPEN/CNEN-SP, Sao Paulo, SP (Brazil)]. E-mail: corain.lopes@uol.com.br; Osso Junior, Joao Alberto [Instituto de Pesquisas Energeticas e Nucleares (IPEN/CNEN-SP), Sao Paulo, SP (Brazil)]. E-mail: jaosso@ipen.br

2007-07-01

Over the last years {sup 99m}Tc has become a very important asset in modern nuclear medicine, due to the emission of gamma ray of optimal energy (140 keV) and a suitable half-life (6.04 h). A further attribute of {sup 99m}Tc is its formation from the decay of {sup 99}Mo and the availability from {sup 99}Mo-{sup 99m}Tc generator systems. The most common and practical generator types consist of a chromatographic column packed with aluminium oxide, onto which the highly purified fission product {sup 99}Mo (imported from Canada) is adsorbed in the form of molybdate. {sup 99m}Tc is further eluted with saline solution. The objective of this work is to study the performance and the elution profile of {sup 99m}Tc from high activity generators in order to decrease molybdenum and aluminium concentration. The experiments involved the use of paper filters and Sep Pak columns and also the changing in the time interval between elutions. {sup 99}Mo breakthrough was measured using a dose calibrator and aluminium by UV-Vis spectrophotometry. The best results were achieved using a Sep Pak column containing neutral aluminium oxide. (author)

Diversification in the Supply Chain of (99)Mo Ensures a Future for (99m)Tc.

Science.gov (United States)

Cutler, Cathy S; Schwarz, Sally W

2014-07-01

The uncertain availability of (99m)Tc has become a concern for nuclear medicine departments across the globe. An issue for the United States is that currently it is dependent on a supply of (99m)Tc (from (99)Mo) that is derived solely by production outside the United States. Since the United States uses half the world's (99)Mo production, the U.S. (99)Mo supply chain would be greatly enhanced if a producer were located within the United States. The fragility of the old (99)Mo supply chain is being addressed as new facilities are constructed and new processes are developed to produce (99)Mo without highly enriched uranium. The conversion to low-enriched uranium is necessary to minimize the potential misuse of highly enriched uranium in the world for nonpeaceful means. New production facilities, new methods for the production of (99)Mo, and a new generator elution system for the supply of (99m)Tc are currently being pursued. The progress made in all these areas will be discussed, as they all highlight the need to embrace diversity to ensure that we have a robust and reliable supply of (99m)Tc in the future. © 2014 by the Society of Nuclear Medicine and Molecular Imaging, Inc.

A Survey of Agreement Rate between Simple MTC and Post Contrast T1 Sequence MRI for Diagnosing Active Multiple Sclerosis Plaques

Directory of Open Access Journals (Sweden)

N. Farshchian

2016-07-01

Full Text Available Introduction & Objective: MS is the most common disabling neurological disorder. Identifying new active MS plaques at the onset and clinical status and faster onset of treatment as well as evaluating the response to treatment is important and MRI with contrast is the best indicator for these measures. Materials & Methods: This study was cross-sectional including 62 patients with diagnosed MS. Whose clinical symptoms suggested the recurrence of MS. They were referred to the radiol-ogy department to undergo brain MRI with injection for the diagnosis of active plaques by a neurologist,The Data were analyzed using statistical tests and SPSS 21 software. Results: Based on the sequences of post contrast T1, pre contrast MTC and post contrast MTC 74, 272 and 271 plaques were respectively discovered. Detection of active MS plaques on T1 sequences after injection were in poor accordance and had significant difference with MTC before and after injection. Moreover, detection of active MS plaques on MTC sequences be-fore injection were in good accordance and did not show significant difference with MTC se-quences after injection. Conclusion: Based on these results, it seems that the purpose of MRI in MS patients is deter-mining the amount of active plaques. Sequences of pre contrast and post contrast MTC are significantly more than sequences of post contrast T1. Therefore, using sequences of MTC can be helpful in MRI. (Sci J Hamadan Univ Med Sci 2016; 23 (2:97-102

Simultaneous quantification of MTC-220 and its metabolites in beagle dog plasma by liquid chromatography-tandem mass spectrometry.

Science.gov (United States)

Liu, Xin; Zhao, Manman; Mi, Jiaqi; Liu, Zhihao; Hu, Jinping; Sheng, Li; Wang, Baolian; Li, Dan; Yang, Shuang; Li, Yan

2014-10-01

A sensitive LC-ESI-MS/MS method for simultaneous determination of MTC-220 and its metabolites (paclitaxel and MDA-linker) in dog plasma has been developed and validated. After addition of docetaxel (internal standard), plasma samples containing MTC-220, paclitaxel and MDA-linker were prepared based on a simple protein precipitation by adding two volumes of acetonitrile. The separation was performed on a ZorbaxSB-C18 column (3.5μm, 2.1mm×100mm) at a flow rate of 0.2ml/min, using acetonitrile/water containing 0.1% formic acid (v/v) as mobile phase. The detection was performed on a triple quadrupole tandem mass spectrometer equipped with electrospray ionization (ESI) by selected reaction monitoring (SRM). The MS/MS ion transit ions monitored were 1444.4→623.8 for MTC-220, 876.4→307.9 for paclitaxel, 631.2→531.2 for MDA-linker and 830.2→549.1 for the internal standard. Linear detection responses were obtained for MTC-220, paclitaxel and MDA-linker ranging from 10 to 5000, 5 to 2500 and 5 to 500ng/ml, respectively. The lower limits of quantitation (LLOQs) for MTC-220, paclitaxel and MDA-linker were 10, 5 and 5ng/ml, respectively. The intra-day and inter-day precisions (RSD, %) of the three analytes do not exceed 10.9% except for LLOQs (≤17.50), and the accuracy (RE, %) were within ±17.5% for LLOQs and ±12.6% for the others. The average recoveries of three compounds were greater than 85.0%. The analytes were proved to be stable during all sample storage, preparation and analytic procedures. The validated method was successfully applied to pharmacokinetic studies of MTC-220 and its metabolites in beagle dogs after intravenous infusion of MTC-220 at 2.5mg/kg. Copyright © 2014 Elsevier B.V. All rights reserved.

On the dose calculation at the cellular level and its implications for the RBE of {sup 99m}Tc and {sup 123}I

Energy Technology Data Exchange (ETDEWEB)

Freudenberg, R., E-mail: robert.freudenberg@uniklinikum-dresden.de; Runge, R.; Maucksch, U.; Berger, V.; Kotzerke, J. [University Hospital/Faculty of Medicine Carl Gustav Carus, Technische Universität Dresden, Department of Nuclear Medicine, Dresden, Saxony 01307 (Germany)

2014-06-15

Purpose: Based on the authors’ previous findings concerning the radiotoxicity of{sup 99m}Tc, the authors compared the cellular survival under the influence of this nuclide with that following exposure to the Auger electron emitter {sup 123}I. To evaluate the relative biological effectiveness (RBE) of both radionuclides, knowledge of the absorbed dose is essential. Thus, the authors present the dose calculations and discuss the results based on different models of the radionuclide distribution. Both different target volumes and the influence of the uptake kinetics were considered. Methods: Rat thyroid PC Cl3 cells in culture were incubated with either{sup 99m}Tc or {sup 123}I or were irradiated using 200 kV x-rays in the presence or absence of perchlorate. The clonogenic cell survival was measured via colony formation. In addition, the intracellular radionuclide uptake was quantified. Single-cell dose calculations were based on Monte Carlo simulations performed using Geant4. Results: Compared with external radiation using x-rays (D{sub 37} = 2.6 Gy), the radionuclides {sup 99m}Tc (D{sub 37} = 3.5 Gy), and {sup 123}I (D{sub 37} = 3.8 Gy) were less toxic in the presence of perchlorate. In the absence of perchlorate, the amount of activity a{sub 37} that was necessary to reduce the surviving fraction (SF) to 0.37 was 22.8 times lower for {sup 99m}Tc and 12.4 times lower for {sup 123}I because of the dose increase caused by intracellular radionuclide accumulation. When the cell nucleus was considered as the target for the dose calculation, the authors found a RBE of 2.18 for {sup 99m}Tc and RBE = 3.43 for {sup 123}I. Meanwhile, regarding the dose to the entire cell, RBE = 0.75 for {sup 99m}Tc and RBE = 1.87 for {sup 123}I. The dose to the entire cell was chosen as the dose criterion because of the intracellular radionuclide accumulation, which was found to occur solely in the cytoplasm. The calculated number of intracellular decays per cell was (975 ± 109) decays

/sup 99m/Tc dextran: a new blood-pool-labeling agent for radionuclide angiocardiography

International Nuclear Information System (INIS)

Henze, E.; Robinson, G.D.; Kuhl, D.E.; Schelbert, H.R.

1982-01-01

We have explored the possibility of imaging the cardiac blood pool with dextran (Dx) labeled with /sup 99m/Tc (Tc) after Sn2+ reduction. Stannous dextran (SnDx) kits were prepared in advance and labeling was performed by adding /sup 99m/Tc. The labeling efficiency was greater than 95%. /sup 99m/Tc dextran (TcDx) was highly stable both in vivo and in vitro. In seven dogs we compared the quality of blood-pool images obtained with TcDx of different molecular weights (4 X 10(4) . Dx-40; 5 X 10(5) . Dx-500; 2 X 10(6) . Dx-2000) and with /sup 99m/Tc red blood cells (TcRBC) labeled in vitro, and determined the organ distribution of this new agent by whole-body scanning and blood sampling. TcDx provided high-quality cardiac blood-pool images up to 60 min after injection. The heart-to-lung ratios averaged 3.7 for TcDx-40, 3.9 for TcDx-500, and 5.4 for TcRBC at 60 min. Whereas TcDx-40 showed a relatively rapid initial urinary excretion and TcDx-2000 was degraded rapidly, TcDx-500 demonstrated the best kinetics for blood-pool imaging. Thus, TcDx is a new radiopharmaceutical with high labeling efficiency and stability. It overcomes a number of the limitations of currently used blood-labeling agents and may become useful for blood-pool imaging in man

Development of kits for 99mTc radiopharmaceuticals for infection imaging. Report of a co-ordinated research project 2000-2003

International Nuclear Information System (INIS)

2004-09-01

Infectious diseases remain a major health problem and cause of death worldwide, particularly in developing countries. Nuclear medicine imaging, because of its sensitivity, offers an attractive option for diagnosis of focal infections. This needs a reliable radiopharmaceutical that can selectively concentrate in sites of infection. Over the years 67 Ga and other radiopharmaceuticals that localize in inflammation associated with infection sites, also known as 'non-specific agents' have been used for infection imaging. However, experience has shown that an 'infection specific agent' that concentrates selectively at sites of infection and not inflammation would have several advantages. The first such agent developed more than two decades ago was 111 In-leucocytes which is still considered a 'gold standard'. Considerations of cost, availability, and superior properties for imaging make 99 mTc a better label than 111 In. 99 mTc white blood cell (WBC) was developed subsequently and used for infection imaging. However, both 111 In and 99 mTc WBCs have a number of drawbacks, in particular: each patient's blood sample has to be collected and individually radiolabelled; well-trained staff and suitable facilities for separating and labelling the patient's blood are needed; the risk of infection and cross-contamination associated with potential blood-borne microorganisms; and cost of materials. Because of these, considerable efforts have been continuously made towards developing convenient replacements for 99 mTc WBCs with limited success, 99 mTc antigranulocyte antibody being a good example. However, these radiopharmaceuticals still have many disadvantages, related to either their cost and availability or their performance. In view of the large potential for applications in patients, the development of new and improved 99 mTc labelled infection specific imaging agents was considered as a very worthwhile aim for scientific research in general and, in particular, for the

Studies on the preparation of sup(99m)Tc labelled medical tracer compounds: pt. 4

International Nuclear Information System (INIS)

Kim, J.R.; Park, K.B.; Shim, H.S.

1981-01-01

A crude extract from a Korean native plant, Banha (Pinellia ternata), has been known to agglutinate the erythrocytes of rabbit, mouse and especially erythrocytes of leukemic patients, Sarcoma-180 cell and Ehrlich ascite cell. The Banha lectin was labelled either with 125 with 125 I by means of chloramine-T method or with sup(99m)Tc by using aqueous sodium pertechnetate (- sup(99m)Tc) solution and stannous chloride as a reducing agent. Their labelling yield was 60% and 98%, respectively. These labelled compounds were administered to mice by intraperitoneal injections and their radioactivity distributions were measured after 3 hours. The uptake of 125 I labelled compound to tissue in mice appeared in the order of kidney, pancreas, spleen, liver, blood, and stomach, but in the case of sup(99m)Tc, it appeared in the order of kidney, pancreas, stomach, liver, spleen and blood

Production of kits for the labelling with 113sup(m)In and sup(99m)Tc, at the CNEA

International Nuclear Information System (INIS)

Palcos, M.C.; Kurcbart, Horacio; Nowotny, G.; Ramos, Elsa; Riesgo, J.G.; Mitta, A.E.A.

1978-05-01

The actual state of the production of radiopharmaceuticals in the form of reagents kits at the C.N.E.A. is described. This could allow the users to label compounds with sup(113m)In and sup(99m)Tc in an easy and reproducible way. At present, the following sets are provided routinarily a) To label with sup(99m)Tc: Albumin macroaggregates: calcium gluconate; antimonium sulfide colloid, sodium phytate; sodium calcium DTPA; seroalbumin; sodium pyrophosphate; sodium citrate. b) To label with sup(113m)In: albumin macroaggregates; PVP-bicarbonate; DTPA; human seroalbumin. Regarding products in a developping stage, we have: to labed with sup(99m)Tc: dimercapto-succinic acid, set for the labelling of human erythrocytes, set for sup(113m)In and sup(99m)Tc concentration and bleomicin; to label with sup(113m)In: EDTMP sup(99m)In. (author) [es

Technetium {sup 99m}Tc Pertechnetate Brain Scanning

Energy Technology Data Exchange (ETDEWEB)

Rhee, Sang Min; Park, Jin Yung; Lee, Ahn Ki; Chung, Choo Il; Hong, Chang Gi [Capital Army Hospital, ROKA, Seoul (Korea, Republic of); Rhee, Chong Heon; Koh, Chang Soon [Radiological Research Institute, Seoul (Korea, Republic of)

1968-03-15

Technetium {sup 99}mTc pertechnetate brain scanning were performed in 3 cases of head injury (2 chronic subdural hematomas and 1 acute epidural hematoma), 2 cases of brain abscess and 1 case of intracerebral hematoma associated with arteriovenous anomaly. In all the cases brain scintigrams showed 'hot areas.' Literatures on radioisotope scanning of intracranial lesions were briefly reviewed. With the improvement of radioisotope scanner and development of new radiopharmaceuticals brain scanning became a safe and useful screening test for diagnosis of intracranial lesions. Brain scanning can be easily performed even to a moribund patient without any discomfort and risk to the patient which are associated with cerebral angiography or pneumoencephalography. Brain scanning has been useful in diagnosis of brain tumor, brain abscess, subdural hematoma, and cerebral vascular diseases. In 80 to 90% of brain tumors positive scintigrams can be expected. Early studies were done with 203 Hg-Neohydrin or {sup 131}I-serum albumin. With these agents, however, patients receive rather much radiation to the whole body and kidneys. In 1965 Harper introduced {sup 99}mTc to reduce radiation dose to the patient and improve statistical variation in isotope scanning.

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

PENGARUH REGENERASI KOLOM ALUMINA ASAM TERHADAP RECOVERY DAN KUALITAS 99mTc HASIL EKSTRAKSI PELARUT MEK DARI 99Mo HASIL AKTIVASI NEUTRON

Directory of Open Access Journals (Sweden)

Adang H G

2017-01-01

Full Text Available ABSTRAK PENGARUH REGENERASI KOLOM ALUMINA ASAM TERHADAP RECOVERY DAN KUALITAS 99mTc HASIL EKSTRAKSI PELARUT MEK DARI 99Mo HASIL AKTIVASI NEUTRON. Melalui kerjasama antara PTRR-BATAN, Chiyoda dan JAEA Jepang telah dilakukan pemurnian 99mTc dari 99Mo hasil aktivasi neutron dengan menggunakan metode kromatografi kolom alumina asam terhadap hasil ekstraksi MEK (Metil Etil Keton. Pemurnian 99mTc dengan metode kolom alumina asam hanya dapat digunakan satu kali dan pemurnian berikutnya harus diganti dengan kolom baru. Hal ini dinilai kurang praktis dan juga memerlukan biaya yang mahal. Dalam penelitian ini dicoba penggunaan kolom alumina asam untuk pemurnian 99mTc lebih dari satu kali dengan melakukan proses regenerasi dengan cara melewatkan larutan HNO3 0,1N setiap kali proses pemurnian selesai. Penelitian ini bertujuan untuk mendapatkan larutan 99mTc yang dapat digunakan untuk penandaan kit radiofarmaka. Parameter yang diamati dalam penelitian ini adalah recovery, profil elusi, pH, kemurnian radiokimia dan kemurnian radionuklida (lolosan 99Mo. Hasil penelitian yang dilakukan selama 5 hari telah diperoleh pH ~5, recovery > 60 %, kemurnian radiokimia > 95 % dan lolosan 99Mo tidak terdeteksi. Dari hasil perlakuan terhadap kolom alumina asam dengan larutan HNO3 0,1 N disimpulkan bahwa kolom alumina asam tidak perlu diganti setiap hari. Kata kunci: 99mTc, 99Mo, MEK, kolom alumina asam, kemurnian radiokimia. ABSTRACT Purification of 99mTc from 99Mo activation using acidic alumina column chromatography system from MEK (Methyl Ethyl Keton extraction has been carried out through cooperation between PTRR - BATAN, Chiyoda and JAEA Japan. This method has a limitation that acidic alumina column for purification of 99mTc can be used only once, for the next purification acidic alumina column should be replaced with new column, so it is less practical and also requires high cost. This study aims to obtain a 99mTc solution can be use for labelling of a

Synthesis and evaluation of hydroxamamide-based tetradentate ligands as a new class of thiol-free chelating molecules for 99mTc radiopharmaceuticals.

Science.gov (United States)

Xu, L C; Nakayama, M; Harada, K; Nakayama, H; Tomiguchi, S; Kojima, A; Takahashi, M; Arano, Y

1998-04-01

Both N,N'-ethylene bis(benzohydroxamamide) [(C2(BHam)2)] and N,N'-propylene bis(benzohydroxamamide) [(C3(BHam)2)] were designed as new thiol-free chelating molecules for 99mTc radiopharmaceuticals. Synthetic procedures using oxadiazoline intermediates were developed for C2(BHam)2 and C3(BHam)2. Both C2(BHam)2 and C3(BHam)2 formed 99mTc complexes with high yields over a wide pH range (pH 3-12) at room temperature. Complexation yields of over 95% were achieved at ligand concentrations as low as 2.5 x 10(-6) M. Reversed-phase HPLC analyses indicated that both C2(BHam)2 and C3(BHam)2 formed 99mTc complexes as single species with stabilities much higher than those of 99mTc-BHam. Selective complex formation of 99mTc with the two ligands was observed in the presence of human IgG. No decomposition with low protein binding were demonstrated when the two 99mTc complexes were incubated in murine plasma. Although further structural studies are required, these findings implied that the Ham-based tetradentate ligands would serve as new chelating molecules for 99mTc radiopharmaceuticals.

Effects of triiodothyronine upon the 131I and sup(99m)Tc uptake by the submandibular salivary glands in A2G mice

International Nuclear Information System (INIS)

Houssay, A.B.; Gamper, C.H.; Curbelo, H.M.

1977-01-01

The organ:plasma ratios and the isotope uptake in thyroid and submandibular glands were measured at different time intervals after a tracer dose of 131 I or sup(99m)Tc. Triiodothyronine depressed markedly the isotope uptake in both glands, but the inhibition of 131 I or sup(99m)Tc uptake by the thyroids was obtained with much lower doses. Thyrotrophin, while increasing markedly the 131 I or sup(99m)Tc uptake by the thyroids, did not produce any change in the 131 I or sup(99m)Tc uptake by the submandibular glands, when given either to normal or to triiodothyronine-inhibited mice. (author)

Synthesis, Characterization and Biological Studies of 99mTc and 188Re Peptides

Science.gov (United States)

Sanders, Vanessa

Radiopharmaceuticals are very powerful diagnostic tools for evaluation of a host of medical conditions. These drugs are labeled with radioactive isotopes, which are utilized to create pictures of areas of interest through absorption of the drug. They are currently in high demand due to their ability to image areas that traditional imaging devices cannot. The radioisotope 99mTc, with a half-life of 6.01 hours and a 140 keV gamma emission, is central to many radiopharmaceutical compounds. This isotope is easily obtained from a 99Mo-99mTc generator, through beta decay and column chromatography separations. Very little technetium, less than 6 ng, is needed to label the pharmaceuticals for use in-vivo. Another radioisotope 188Re is also important due to its ability to be used for therapy while being tracked throughout the body. Radiotherapy gives radiopharmaceuticals a huge advantage by their ability to destroy rapidly growing cells. One of the main reasons there is interest in rhenium pharmaceuticals is the chemical similarity between it and technetium. The 188Re isotope also has a considerably short half-life of approximately 17 hours and has emission energy of 155 keV. The 188Re isotope is separated from 188W-188Re generator, analogously to the 99Mo-99mTc generator. The ligand used in this work is a pentapepetide macrocyclic ligand. This ligand, KYCAR (lysyl-tyrosyl-cystyl-alanyl-arginine), has been designed as a potential chelating ligand for imaging and therapeutic in vivo agents. Ligands are chosen based on their in-situ biological behavior, and are used in the complexation with technetium and rhenium. Understanding and exploiting technetium and rhenium chemistry can provide insight into the reaction mechanisms and coordination chemistry of these compounds. The exploration of various oxidation states as a function of the ligands used and the reaction conditions can help develop novel radiopharmaceuticals. The investigations of the manipulation of oxidation states

The labelling of antibody anti-PBP2a with {sup 99m}Tc; Estudo de marcacao do anticorpo monoclonal anti-PBP2a com {sup 99m}Tc

Energy Technology Data Exchange (ETDEWEB)

Mororo, Janio da Silva

2012-07-01

Staphylococcus aureus is a major cause of life-threatening infections such as bacteraemia and endocarditis. Unfortunately, many strains of this bacterial species have become resistant to certain antibiotics, including methicillin and amoxicillin. These strains are known as methicillin-resistant S. aureus (MRSA). The penicillin binding protein 2a (PBP2a) is the enzyme responsible for conferring resistance p-lactams antibiotics for MRSA, being one promising molecule for therapy with mAb. However, besides the therapy, the methods of diagnosis are also inefficient because the diagnosis currently takes several days to produce a reliable result. Taking into account, the objective of this research was radiolabeling one anti-PBP2a mAb developed by Bio-Manguinhos/FioCruz-RJ, utilizing {sup 99m}Tc, for in situ diagnostic of the infectious caused by MRSA. First, anti-PBP2a mAb was reduced utilizing 2-mecaptoethanol (2-ME) for generate sulphydryl groups (-SH) and after to be labeled with {sup 99m}Tc. In this work, were utilized two techniques of direct method: Method 1, using tartrate and gentisic acid reagents, acting like transchelant and stabilizer agents, respectively; and Method 2, using one commercial kit of MDP. Besides the radiolabeling, the mAb reduced and mAb labeled with {sup 99m}Tc were submitted to immunoreactivity analysis, with SDS-PAGE non-reducing, Immunoblotting, ELISA and neutralization assay in vitro methods. The quantity produced of sulphydryl groups by mAb was satisfactory, approximately 5 per mAb, utilizing 6.500:1 of 2-ME:mAb molar ratio. The better labeling method was Method 2, with labeling yield of 73.5%, and showed a good stability after 2 hours (73.2%). The better formulation was: 0.5 mg of mAb anti- PBP2a, 10 {mu}U of MDP kit, after resuspended with 5 mL of saline, and 75.48 MBq (2.04 mCi) of {sup 99m}Tc, reacting by 15 minutes. The labeled mAb maintained the immunoreactivity, utilizing immunologic and in vitro experiments. (author)

Evaluation of patellar chondromalacia with MR: comparison between T2-weighted FSE SPIR and GE MTC.

Science.gov (United States)

Macarini, Luca; Perrone, Alessandra; Murrone, Mario; Marini, Stefania; Stefanelli, Michele

2004-09-01

To compare two different MR sequences to tissue signal suppression in the study of patellar cartilage abnormalities. We examined 26 patients with magnetic resonance (MR) imaging: sequences included spectral presaturation with inversion recovery (SPIR), with fat suppression and T2-weighted images, magnetization transfer contrast (MTC) sequences, T1-weighted and T2-weighted spin-echo sequences. All patients underwent conventional knee arthroscopy and in all patients a hyaline cartilage lesion was assessed in three articular zones: the patellar medial facet, the lateral facet and the patellar crista. Was assessed 78 articular facets. The lesions were classified using a standard arthroscopic grading system adapted to MR imaging: normal cartilage that corresponds to the grade 0 according to the Noyes grading system, low grade lesions that correspond to the grade I e IIa and high grade lesions that correspond to grades IIb and III. The arthroscopic results were compared with MR images. We assessed the MR diagnostic accuracy, sensitivity, specificity and MR positive predictive value and negative predictive value of the two sequences taking into consideration total lesions, and high-grade and low grade lesions separately. Twenty-four low grade lesions (16 grade I e 8 grade IIa) and 18 high grade lesions (10 grade IIb e 8 grade III) were diagnosed by arthroscopy. Regarding low grade and high-grade lesions together, the accuracy was 77% for MTC sequences and 90% for SPIR sequences. In identifying low-grade lesions, the sensitivity was 88% for SPIR sequence and 42% for MTC sequences. Specificity for the detection of all lesions was 89% for the SPIR sequences and 94% for the MTC sequences. The SPIR sequence visualised water content abnormalities in degenerating cartilage, which are representative of low-grade lesions. The sensitivity of the sequence enabled us to obtain improved contrast for detecting cartilage surface irregularities. The MTC sequences allowed us to grade high

Transfer of 131I and sup(95m)Tc from pasture to goat milk

International Nuclear Information System (INIS)

Bondietti, E.A.; Garten, C.T. Jr.

1986-01-01

The purpose of this research was to compare the behaviour of 131 I (Tsub(1/2)=8.0d) and sup(95m)Tc (Tsub(1/2)=61d), which were sprayed on to pasture that was subsequently grazed by a herd of dairy goats. The transfer of 131 I to goats milk was about 5600 times more than that of sup(95m)Tc after 5 d of grazing contaminated pasture. Most of the difference appeared to be explained by a progressive immobilisation of technetium on vegetation, which occurred during the first few days of the experiment. (UK)

Study of gels of molybdenum with cerium in the preparation of generators of 99Mo - 99mTc

Directory of Open Access Journals (Sweden)

Vanessa Moraes

2005-10-01

Full Text Available 99mTc has ideal nuclear properties for organ imaging in nuclear medicine, and it is obtained from the 99Mo-99mTc generator. Four different types of generators are available: chromatographic that uses 99Mo from fission of uranium; MEK solvent extraction; Tc2O7 sublimation; gel chromatographic. This work presents the preparation of gel generators of molybdenum with cerium and characterization of the gels: mass ratio between molybdenum and cerium, structure, size of particles and elution percentage of 99mTc after irradiating the gels. Eight gels were prepared at the same temperature of 50 ºC with concentrations of NaOH of 2 and 4 mol/L, mass ratio of 0.31 and 0.38 and final pH of 3.5 and 4.5. The analysis of the results proved that these gels are not adequate for preparation of the generators of 99Mo-99mTc, since the elution percentages are low, when compared with the gel of molybdenum with zirconium.O 99mTc é o radiofármaco mais utilizado em Medicina Nuclear. Ele é obtido do gerador de 99Mo-99mTc e existem quatro tipos diferentes de geradores: cromatográfico que utiliza 99Mo de fissão; extração por solvente com MKT; sublimação do heptaóxido de tecnécio; cromatográfico tipo gel. Este trabalho apresenta a preparação de geradores tipo gel de molibdênio com cério, a caracterização desses géis com relação à quantidade de molibdênio e de cério, sua estrutura, tamanho das partículas e porcentagem de eluição do 99mTc após o gel ser irradiado. Foram preparados oito géis na temperatura de 50ºC com concentração de NaOH de 2 e 4 mol/L, relação de massa de 0,31 e 0,38 e pH final de 3,5 e 4,5. A análise dos resultados comprovou que esses géis não são adequados para preparação dos geradores de 99Mo-99mTc, já que as porcentagens de eluição são baixas, quando comparadas com o gel de molibdênio com zircônio.

99mTc ovalbumin labelled eggs for gastric emptying scintigraphy: in-vitro comparison of solid food markers.

Science.gov (United States)

Blanc, Frédérique; Salaun, Pierre Y; Couturier, Olivier; Querellou, Solène; Le Duc-Pennec, Alexandra; Mougin-Degraef, Marie; Bizais, Yves; Legendre, Jean M

2005-11-01

The reliability of solid phase gastric emptying measurements by scintigraphy requires a marker that remains within the solid component of the test meal, and which is not degraded by the gastric juice throughout the scintigraphic procedure. In Europe, foods are most often labelled with 99mTc rhenium sulfide macrocolloid (RSMC) but this solid phase marker was withdrawn from the market in January 2004. To test other potential solid phase markers and to compare them to the reference marker RSMC. These markers were rhenium sulfide nanocolloid (RSNC), tin fluoride colloid (TFC), phytates and two albumins (Alb and AlbC). All were radiolabelled with 99mTc. After quality control, each 99mTc marker was incorporated into the albumin of one egg. Then, egg white and yolk were mixed together, and a well-cooked omelette was prepared. Aliquots of the omelette were incubated with an acidic solution of pepsin at 37 degrees C which mimicked gastric juice. Unbound radioactivity in the supernatant fraction was measured at various times up to 3 h. The radiochemical purity was > 95% for all radiopharmaceuticals. During the in-vitro incubation, the percentage of 99mTc labelled colloids released from the omelette increased continuously: after 3 h, 5% for TFC and RSMC, 8% for phytates, and > 9% for the two albumins and RSNC. Considering quality controls and release of 99mTc during in-vitro incubation of the omelette, TFC showed the same behaviour as the reference marker RSMC. Thus, TFC seems to be the best candidate to replace RSMC for the radiolabelling of the solid phase of the gastric emptying test meal.

A neutral lipophilic complex of sup(99m)Tc with a multidentate amine oxime

International Nuclear Information System (INIS)

Troutner, D.E.; Volkert, W.A.; Hoffman, T.J.; Holmes, R.A.

1984-01-01

Propylene amine oxime, 3,3'-(1,3-propanediyldiimino)bis(3-methyl-2-butanone)dioxime, (PnAO) forms a neutral lipophilic complex with sup(99m)Tc in >95% yield at room temperature at pH 5-10. The complex can be prepared with generator produced sup(99m)Tc using 10 -5 M SnC 4 H 4 O 6 as the reducing agent at ligand concentrations as low as 3 x 10 -5 M. It is stable in saline solutions for as long as 24 h. [Sup(99m)Tc]PnAO may be useful as an imaging agent which passively diffuses across the blood brain barrier. (author)

ACS labelled with sup(99m)Tc and cartilage scintigraphy

International Nuclear Information System (INIS)

Dupuy, J.C.; Harmand, M.F.; Blanquet, P.

1976-01-01

ACS, chondroitine-sulphate acid, is the principal mucopolysaccharide of cartilagineous substance. We therefore thought it of interest to label this molecule with sup(99m)Tc so as to obtain a scintigraphic image of cartilagineous formations. sup(99m)Tc-pyrophosphate and the sup(99m)Tc-polyphosphates permit simultaneous imaging of hyperactive zones in bone and cartilage. The ACS-labelling technique is based on the reduction of sup(99m)Tc-pertechnetate by the tin-II-ion. Sephadex-gel chromatography at different pH-levels was used to study labelling gain, under optimum conditions it can attain 85%. The labelled product was administered intravenously and studied in rat and rabbit. An identical biological half-life of 15 minutes was found for both species. Scintigraphes from rabbits permitted clear visualization of the epiphyses of tubular bones, intervertebral cartilage, and auricular cartilage. These encouraging results point to interesting clinical applications

Comparative analysis of hepatopulmonary shunt obtained from pretherapy 99mTc MAA scintigraphy and post-therapy 90Y Bremsstrahlung imaging in 90Y microsphere therapy.

Science.gov (United States)

Jha, Ashish Kumar A; Zade, Anand A; Rangarajan, Venkatesh; Purandare, Nilendu; Shah, Sneha A; Agrawal, Archi; Kulkarni, Suyash S; Shetty, Nitin

2012-05-01

(99m)Tc macroaggregate albumin (MAA) scintigraphy is routinely used to estimate the hepatopulmonary shunt (HPS) of (90)Y microspheres because of their comparable average particle sizes (20-30 µm). However, the MAA particle size can vary from 10 to 90 µm. Therefore, HPS computed from (99m)Tc MAA scintigraphy may not accurately represent the HPS of (90)Y microspheres. In view of this, the present study was undertaken to investigate the accuracy of (99m)Tc MAA scintigraphy in estimating the HPS of (90)Y microspheres. Nineteen sessions of transarterial radioembolization using (90)Y therasphere were carried out in 17 patients for hepatic malignancies (both primary and secondary). For each session of therapy, a pretherapeutic (99m)Tc MAA scintigraphy and post-therapeutic (90)Y Bremsstrahlung scintigraphy were performed. The HPSs obtained from these images were compared. The mean HPS fractions calculated from the pretherapeutic (99m)Tc MAA study and the post-therapeutic (90)Y Bremsstrahlung images were 4.77 ± 2.81 and 4.52 ± 2.5%, respectively. The coefficient of correlation (r) was 0.96. (99m)Tc MAA scintigraphy accurately predicts the HPS of (90)Y microspheres.

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)

Preparation and labelling hydroxyapatite with 223Ra and 99mTc

International Nuclear Information System (INIS)

Malkova, E.; Micolova, P.; Vlk, M.; Kozempel, J.; Rabyk, M.

2015-01-01

The aim of this study was the preparation, studies and investigation of novel nanoparticles suitable for targeted delivery of 223 Ra and 99 mTc. Preliminary experiments were focused on the synthesis of hydroxyapatite nanoparticles (HANPs) and their affinity to 223 Ra and 99m Tc. Technetium-99m ( 99 mTc, T 1 /2 = 6.0 h) is the most commonly used medical radionuclide for diagnostic procedures. Radium-223 is the first -emitting radionuclide approved for targeted radionuclide therapy. The physical half-life of 223 Ra of 11.4 days is providing sufficient time for the synthesis, distribution and administration of the radiopharmaceutical to patients. HANPs labelling yields with 223 Ra were 95 - 100 % and with 99m Tc were 93 - 94 % depending on the reaction conditions. HANPs were studied on FT-IR (Fourier transform infrared spectroscopy), XRPD (X-Ray Powder Diffraction), DLS (Dynamic Light Scattering), and the sizes of nanoparticles were studied at temperatures 80, 120 and 200 grad C. (authors)

Evaluation of sup(99m)Tc labeled amino acids as radiopharmaceuticals, 4. S-substituted cysteines and N-substituted iminodiacetic acids

Energy Technology Data Exchange (ETDEWEB)

Karube, Yoshiharu; Maeda, Tatsuo; Ohya, Masato; Sugata, Setsuro; Kono, Akira (Kyushu Cancer Center Research Inst., Fukuoka (Japan)); Matsushima, Yoshikazu

1982-06-01

Sixteen sup(99m)Tc labeled ligands were evaluated as scintigraphic agents. The ligands studied were cysteine, glutathione, their S-substituted derivatives, lysine-N sup(epsilon), N sup(epsilon)-diacetic acid, glycylglycine-N,N-diacetic acid, glycylglycylglycine-N,N-diacetic acid, taurine-N,N-diacetic acid, hydrazine-N,N-diacetic acid, ethylenediamine-N,N-diacetic acid, and propylne-1,3-diamine-N/sup 1/-,N/sup 1/-diacetic acid. The ligands were labeled with sup(99m)Tc by the SnCl/sub 2/ method with more than 95% yield. The in vivo behavior of the sup(99m)Tc labeled ligands were studied in golden hamsters and dogs. The organ distribution in golden hamsters indicated clearance both by hepatobiliary and renal systems. The pancreas/blood ratios were much lower in the sup(99m)Tc ligands than in /sup 75/Se-selenomethionine. Scintigraphic studies in dogs showed that the liver and kidneys were well visualized but the accumulation by the pancreas was not sufficient for clear visualization.

Technetium-Iron Complex. Radiopharmaceutical for Renal Scanning and Function Studies

Energy Technology Data Exchange (ETDEWEB)

Aquino, J. A.; Cunningham, R. M. [Victoria General Hospital and Dalhousie Medical School, Halifax, NS (Canada)

1969-05-15

A preliminary report on the use of a technetium-iron complex as a radiopharmaceutical in the evaluation of kidney function as well as renal scanning is presented. The first part considers the {sup 99m}Tc iron complex as an agent to determine the kidney function. This is correlated with the conventional {sup 131}I Hippuran renogram as well as the mercury accumulative test. The second part describes the use of the {sup 99m}Tc iron complex as a renal scanning agent; again it is compared with {sup 197}Hg Neohydrin. The availability of the Anger gamma camera, along with {sup 99m}Tc and its favourable characteristics have encouraged further search for better preparations. Among these is the {sup 99m}Tc iron complex. The authors' technique of preparation is described. Although the pertechnetate ion is not very active chemically in combining with other compounds, it is readily reduced to more reactive lower valence states. Such alterations of chemical form produce changes in biologic localization of {sup 99m}Tc. After the intravenous injection of {sup 99m}Tc as pertechnetate, it is rapidly localized in the stomach, urinary bladder, thyroid, and salivary glands. Excretion during the first 24 h occurs largely through the urine. Harper et al. have shown that the {sup 99m}Tc iron complex is rapidly excreted through the urine. The initial disappearance from the plasma is so very rapid that 50% or more has usually left the blood in 3-5 min. Part of the 5'irnTc is fixed in the kidney which constitutes half of what is retained in the body. Our technique consists of obtaining the conventional {sup 131}I Hippuran renogram. This is followed by the injection of {sup 99m}Tc iron complex. The two renograms obtained, using the two agents, are correlated along with other diagnostic tests. Since the {sup 99m}Tc iron complex used for doing the renogram can be used in scanning the kidney, both kidneys are scanned using the Anger gamma camera. Comparative scans are done with the use of {sup

Quality audit programme for {sup 99m}Tc and {sup 131}I radioactivity measurements with radionuclide calibrators

Energy Technology Data Exchange (ETDEWEB)

Joseph, Leena [Radiation Safety Systems Division, Bhabha Atomic Research Centre, Mumbai 400 085 (India)], E-mail: leena@barc.gov.in; Anuradha, R.; Kulkarni, D.B. [Radiation Safety Systems Division, Bhabha Atomic Research Centre, Mumbai 400 085 (India)

2008-06-15

The use of radiopharmaceuticals in nuclear medicine for diagnosis and therapy has increased over the years with {sup 99m}Tc and {sup 131}I being most widely used. Quality audit programmes for radioactivity measurements of {sup 131}I have been ongoing and the 12th audit was recently conducted among seventy nuclear medicine centres (NMC) in India. An audit for the activity measurements of {sup 99m}Tc was conducted for the first time among ten NMCs in Mumbai, India. These programmes for radioactivity measurements have become very important to establish traceability of measurements to national and international standards and ensure accurate calibration of radionuclide calibrators. The results of both the audits are very encouraging. Ninety-four percent of the NMCs for {sup 131}I activity measurements were within a window of {+-}10% and for {sup 99m}Tc one NMC was deviating more than {+-}10%. The methodology adopted for the audit and results are discussed in detail in this paper.

{sup 99m}Tc-3PRGD{sub 2} SPECT to monitor early response to neoadjuvant chemotherapy in stage II and III breast cancer

Energy Technology Data Exchange (ETDEWEB)

Ji, Bin; Chen, Bin; Wang, Ting; Chen, Minglong; Ji, Tiefeng; Gao, Shi; Ma, Qingjie [China-Japan Union Hospital of Jilin University, Department of Nuclear Medicine, Changchun (China); Song, Yan [China-Japan Union Hospital of Jilin University, Department of Breast Surgery, Changchun (China); Wang, Xueju [China-Japan Union Hospital of Jilin University, Department of Pathology, Changchun (China)

2015-08-15

Monitoring of response to neoadjuvant chemotherapy (NCT) is important for optimal management of patients with breast cancer. {sup 99m}Tc-3PRGD{sub 2} SPECT is a newly developed imaging modality for evaluating tumor vascular status. In this study, we investigated the application of {sup 99m}Tc-3PRGD{sub 2} SPECT in evaluating therapy response to NCT in patients with stage II or III breast cancer. Thirty-three patients were scheduled to undergo {sup 99m}Tc-3PRGD{sub 2} SPECT at baseline, after the first and second cycle of NCT. Four patients had extremely low {sup 99m}Tc-3PRGD{sub 2} uptake at baseline, and were not included in the subsequent studies. Changes in tumor to nontumor (T/N) ratio were compared with pathological tumor responses classified using the residual cancer burden system. Receiver operator characteristic analysis was used to compare the power to identify responders between the end of the first and the end of the second cycle of NCT. The impact of breast cancer subtype on {sup 99m}Tc-3PRGD{sub 2} uptake was evaluated. The correlation between {sup 99m}Tc-3PRGD{sub 2} uptake and pathological tumor response was also evaluated in each breast cancer subtype. Surgery was performed after four cycles of NCT and pathological analysis revealed 18 responders and 15 nonresponders. In patients with clearly visible {sup 99m}Tc-3PRGD{sub 2} uptake at baseline, the sensitivity, specificity, and negative predictive value of {sup 99m}Tc-3PRGD{sub 2} SPECT were 86.7 %, 85.7 % and 86.7 % after the first cycle of NCT, and 92.9 %, 93.3 % and 93.3 % after the second cycle, respectively. Among these patients, the HER-2-positive group demonstrated both higher T/N ratios and a greater change in T/N ratio than patients with other breast cancer subtypes (P < 0.05). A strong correlation was found between changes in T/N ratio and pathological tumor response in the HER-2-positive group (P < 0.03). {sup 99m}Tc-3PRGD{sub 2} SPECT seems to be useful for determining the pathological

Detection of metastatic bone cancer by scintiscanning with sup(99m)Tc labelled sodium pyrophosphate

International Nuclear Information System (INIS)

Kromer, Bernard.

1973-01-01

Bone scanning with sup(99m)Tc sodium pyrophosphate was performed in 65 patients with primary neoplasms, using a gamma-camera. The scans are compared to those obtained with 85 Sr and 87 Sr. Sup(99m)Tc appears to be superior to the other two in the detection of metastatic bone lesions, mainly because of its physical characteristics (high yield of 140 KeV photons, short physical half-life). The advantages related to these characteristics are emphasized: possibility of rapid and systematic investigation of the whole skeleton using a gamma-camera; low dose irradiation of the patient which enables frequent repetitive studies to be performed [fr

Precision measurement of the half-life of {sup 90m}Nb and {sup 99m}Tc

Energy Technology Data Exchange (ETDEWEB)

Kikunaga, H.; Fujisawa, H.; Ooe, K. [Osaka Univ., Toyonaka (Japan). Graduate School of Science] [and others

2011-07-01

We have produced {sup 90m}Nb and {sup 99m}Tc in the reactions of {sup nat}Zr(p, xn){sup 90m}Nb and {sup 100}Mo({gamma}, n){sup 99}Mo, followed by disintegration to {sup 99m}Tc, respectively, and measured the halflives of these nuclides by using a reference source method. In order to determine the short half-lives of {sup 90m}Nb precisely, an on-line gas-jet system has been employed. As a result, the half-lives of these nuclides were determined with good precision on the order of magnitude of 0.1%. (orig.)

Development of methods of labeling pentavalent DMSA with {sup 99m}Tc and {sup 188}Re; Desenvolvimento de metodos para marcacao de DMSA pentavalente com {sup 99m}Tc e {sup 188}Re

Energy Technology Data Exchange (ETDEWEB)

Brambilla, Tania de Paula, email: jtoniolo@ipen.br

2009-07-01

Technetium-99 m is the most useful radionuclide in diagnostic imaging procedures in Nuclear Medicine, more than 80 percent of radiopharmaceuticals are {sup 99m}Tc-labeled compounds. {sup 99m}Tc-DMSA(V) has been used for imaging of soft tissue, head and neck tumors. It shows a particularly high specificity for medullary thyroid carcinoma and bone metastases in a variety of cancers. Biodistribution studies of {sup 188}Re-DMSA(V) have shown that its general pharmacokinetic properties are similar to that of {sup 99m}Tc-DMSA(V), so this agent could be used for targeted radiotherapy of these tumors. The aim of this work is the development of methods of labeling DMSA(V) with {sup 99m}Tc and {sup 188}Re. {sup 99m}Tc-DMSA(V) can be prepared by two methods. One of them is the indirect one, through the use of a commercial kit of DMSA (III), by adjusting the pH from 2.5 to {approx} 8.5 with NaHCO{sub 3}. This method was evaluated and optimized presenting high labeling yields. The other method is the direct one, through the preparation of a lyophilised kit ready for labeling with {sup 99m}Tc, being the method of interest of this work, due to the easy of its clinical use. The most adequate formulation of the kit was: 1.71 mg of DMSA, 0.53 mg of SnCl{sub 2}.2H{sub 2}O and 0.83 mg of ascorbic acid (pH 9). Labeling yields higher than 95% were achieved labeling this kit with 1 to 2 m L of {sup 99m}Tc with activities up to 4736 MBq (128 mCi). The kit was stable up to 6 months and biodistribution studies confirmed the quality of the DMSA (V) labeled with {sup 99m}Tc using this kit. The reduction potential of Re is lower than the one for Tc, so the labeling conditions of {sup 188}Re-DMSA(V) are different from the ones used for {sup 99m}Tc- DMSA(V). {sup 188}Re-DMSA(V) is prepared in acid solution, that makes it possible to use the DMSA (III) commercial kit developed for labeling with {sup 99m}Tc, prepared in pH 2.5, for labeling with {sup 188}Re. Labeling yields higher than 95% were

Technetium /sup 99m/Tc macroaggregated albumin lung scans. Use in chronic childhood asthma

International Nuclear Information System (INIS)

Hyde, J.S.; Koch, D.F.; Isenberg, P.D.; Werner, P.

1976-01-01

Serial roentgenograms and technetium /sub 99m/Tc macroaggregated albumin lung scans were done simultaneously in 30 bronchodilator-dependent asthmatic children and young adults during both relative remission and attacks of status asthmaticus. When chest roentgenograms showed air trapping and increased peribronchial vascular markings associated with persistent perfusion defects, the children benefited from further laboratory studies and continuous comprehensive therapy. Serial scans provided information about underperfusion that was not discernible either by roentgenograms or by usual blood gas studies. Also, lung scans are easier to obtain in children with long-standing asthma than are detailed pulmonary tests. In our study, technetium /sup 99m/Tc macroaggregated albumin scans showed persistent regional perfusion defects in 20 children with chronic asthma during relative remission and exacerbations

Transfer of 131I and /sup 95m/Tc from pasture to goat milk

International Nuclear Information System (INIS)

Bondietti, E.A.; Garten, C.T. Jr.

1984-01-01

Field measurements were made in 1983 on the transfer of 131 I and /sup 95m/Tc from spray-contaminated pasture to goat's milk. The transfer of 131 I to milk was similar to that used for mathematical models in US Nuclear Regulatory Commission Regulatory Guide 1.109, which was derived from stall-feeding experiments using capsulized doses. Compared to 131 I, the /sup 95m/Tc transferred to milk was about 5600 times less. The lower transfer resulted from both immobilization of technetium on pasture prior to ingestion as well as reduced gastrointestinal absorption. The results show that the food chain transfer of technetium to milk is much less than that previously expected based on inferences made from metabolism studies. 6 references, 4 figures, 1 table

Achalasia diagnosed by {sup 99m}Tc pertechnetate scintigraphy; Diagnose einer Achalasie durch {sup 99m}Tc-Pertechnetat-Szintigraphie

Energy Technology Data Exchange (ETDEWEB)

Mikosch, P. [Landeskrankenhaus Klagenfurt (Austria). Abt. fuer Nuklearmedizin und Spezielle Endokrinologie; Gallowitsch, H.J. [Landeskrankenhaus Klagenfurt (Austria). Abt. fuer Nuklearmedizin und Spezielle Endokrinologie; Kresnik, E. [Landeskrankenhaus Klagenfurt (Austria). Abt. fuer Nuklearmedizin und Spezielle Endokrinologie; Lind, P. [Landeskrankenhaus Klagenfurt (Austria). Abt. fuer Nuklearmedizin und Spezielle Endokrinologie

1997-06-01

A 73-year-old patient presented a {sup 99m}Tc scintiscan with a focal tracer accumulation left and caudal of the thyroid gland. Further investigations with sonography, CT, esophagoscopy and barium swallow provided the diagnosis of achalasia as the reason for focal {sup 99m}Tc retention caudal of the thyroid gland. Explanation for {sup 99m}Tc accumulation within the esophagus may be the nonspecific accumulation of {sup 99m}Tc not only in the thyroid gland but also in the salivary glands. Excretion of the tracer follows with the saliva. Structural and motor disorders of the esophagus can thus lead to focal tracer retention within the esophagus simulating thyroid tissue. (orig.) [Deutsch] Eine 73jaehrige Patientin zeigte bei der {sup 99m}Tc-Schilddruesenszintigraphie eine von der Schilddruese abgesetzte deutliche fokale Speicherung links kaudal der Schilddruese. Die weitere diagnostische Abklaerung mittels Sonographie, CT, Oesophagoskopie und videoassistiertem Kontrastmittelschluckakt ergab als Ursache der {sup 99m}Tc-Speicherung eine Achalasie. Die Erklaerung einer {sup 99m}Tc-Speicherung in der Speiseroehre waere die unspezifische {sup 99m}Tc-Aufnahme in den Speicheldruesen mit nachfolgender Tracerelimination ueber den Speichel. Depotbildungen von Speichel bei Erkrankungen der Speiseroehre, die mit einer Transportstoerung des Speichels verbunden sind, koennen dadurch Schilddruesengewebe vortaeuschen. (orig.)

Development of {sup 99m}Tc extraction-recovery by solvent extraction method

Energy Technology Data Exchange (ETDEWEB)

Kimura, Akihiro; Nishikata, Kaori; Izumo, Hironobu; Tsuchiya, Kunihiko; Ishihara, Masahiro [Japan Atomic Energy Agency, Oarai Research and Development Center, Oarai, Ibaraki (Japan); Tanase, Masakazu; Fujisaki, Saburo; Shiina, Takayuki; Ohta, Akio; Takeuchi, Nobuhiro [Chiyoda Technol Corp., Tokyo (Japan)

2012-03-15

{sup 99m}Tc is used as a radiopharmaceutical in the medical field for the diagnosis, and manufactured from {sup 99}Mo, the parent nuclide. In this study, the solvent extraction with MEK was selected, and preliminary experiments were carried out using Re instead of {sup 99m}Tc. Two tests were carried out in the experiments; the one is the Re extraction test with MEK from Re-Mo solution, the other is the Re recovery test from the Re-MEK. As to the Re extraction test, and it was clear that the Re extraction yield was more than 90%. Two kinds of Re recovery tests, which are an evaporation method using the evaporator and an adsorption/elution method using the alumina column, were carried out. As to the evaporation method, the Re concentration in the collected solution increased more than 150 times. As to the adsorption/elution method, the Re concentration increased in the eluted solution more than 20 times. (author)

In vivo/in vitro labeling of red blood cells with sup(99m)Tc and clinical applications

International Nuclear Information System (INIS)

Bauer, R.; Langhammer, H.; Pabst, H.W.; Bauer, U.; Sauer, E.

1981-01-01

A reliable and stabile in vivo/in vitro labeling technique of red blood cells (RBC) is described. The patients are injected 20% of the content of an unlabeled kit used for bone scintigraphy (TechneScan PYP, Byk-Mallinckrodt). 15 minutes later 3 ml blood are sampled in a heparinized syringe. The blood is incubated together with 30-40 mCi (1-1.5 GBq) sup(99m)Tc for 10 minutes in a water bath at 35-37 0 C. After centrifugation at 500 g a dose of 15-25 mCi (0.6-1 GBq) sup(99m)Tc labeled RBC may be withdrawn in a volume of 1-1.5 ml. Mean labeling efficiency is 88%, without using the first eluat of a Tc-generator the yield is as high as 92%. Due to the small volume, the labeled RBC may be reinjected as bolus and first pass radionuclide angiocardiography can be performed. Using labeled RBC, scintigraphy of the intravasal space is possible up to 20 hours without deterioration in contrast or accumulation of radioactivity in the extravasal space or in other organs. Evaluation of heart function can be performed up to 10 hours. In addition, labeled RBC are useful in detecting unknown gastrointestinal bleeding. (orig.) [de

Does the chocolate interfere with the radiolabelling of erythrocytes with 99 mTc?; Le chocolat interfere-t-il avec le radiomarquage des erythrocytes au 99 mTc?

Energy Technology Data Exchange (ETDEWEB)

Bustani, H.; Colavolpe, C.; Imbert-Joscht, I.; Moubarik, C.; Havlik, P.; Pisano, P.; Guillet, B. [Service de medecine nucleaire, CHU Nord, Marseille, (France)

2009-05-15

We present in this work the case of a failure of erythrocytes labelling with {sup 99m}Tc for a twenty five years old patient making the examination not interpretable. The patient reported that she drank a chocolate drink the morning before the examination. it is the first observation of a such interaction between the chocolate consumption. We do not have any explanation at this date, some compounds in the cocoa can be considered with caution. Some flavonoids (catechins and pro-cyanidins) modify the plasmatic and intra-erythrocyte oxido-reducer statute and could interact with the labelling (specific reduction of the {sup 99m}Tc pertechnetate in the middle of erythrocyte by the tin pyrophosphate. These compounds, as well as the methyl-xanthine-theobromine, seem modify the membrane permeability of erythrocytes and could interfere with the input of pyrophosphate or {sup 99m}Tc-pertechnetate in the middle of erythrocyte. these observations, in spite of preliminary ones, lead us to recommend near the patients to avoid the chocolate foods in the twenty four hours before this type of examinations. (N.C.)

Preparation of clinical-scale 99Mo/99mTc column generator using neutron activated low specific activity 99Mo and nanocrystalline γ-Al2O3 as column matrix.

Science.gov (United States)

Chakravarty, Rubel; Ram, Ramu; Dash, Ashutosh; Pillai, M R A

2012-10-01

Preparation of clinical-scale (99)Mo/(99m)Tc generator using (n,γ) activated low specific activity (99)Mo and nanocrystalline γ-Al(2)O(3) as a high capacity sorbent matrix is attempted. Nanocrystalline γ-Al(2)O(3) was synthesized by 'solid state mechanochemical' reaction of aluminum nitrate with ammonium bicarbonate. Experimental parameters were optimized to effectively separate (99m)Tc from (99)Mo using this sorbent as the column matrix. The performance features of a 13 GBq (350 mCi) (99)Mo/(99m)Tc generator using this sorbent and (99)Mo produced by (n,γ) route having specific activity 12.9-18.5 GBq/g were evaluated for 10 days. The sorbent possessed the requisite selectivity for (99)Mo and demonstrated a maximum sorption capacity of 200 ± 5mg Mo/g, which is ~10 times higher than that of ordinary acidic alumina. The overall yield of (99m)Tc was >80%, with radionuclidic purity >99.99% and radiochemical purity >99%. The yield of (99m)Tc varied from 7.8 to 2.1 GBq in the eluate for the six days of operation of the generator. The radioactive concentration of (99m)Tc eluted was adequate for the formulation of radiopharmaceuticals. The performance of the generator remained consistent over an extended period of 10 days. The eluted (99m)Tc was suitable for the formulation of (99m)Tc-DMSA and (99m)Tc-EC resulting in high radiolabeling yields (>98%). The effectiveness of γ-Al(2)O(3) as a new generation sorbent in the development of clinically useful (99)Mo/(99m)Tc generator using low specific activity (99)Mo and yielding (99m)Tc with adequate radioactive concentration and high purity suitable for formulation of radiopharmaceuticals is demonstrated. Copyright © 2012 Elsevier Inc. All rights reserved.

Studies of monoclonal antibodies IOR-CEA-1 and IOR-EGF/R3 labelled with {sup 99m}Tc; Estudo de marcacao dos anticorpos monoclonais IOR-CEA-1 e IOR-EGF/R3 com {sup 99m}Tc

Energy Technology Data Exchange (ETDEWEB)

Dias, Carla Roberta de Barros Rodrigues

2005-07-01

Nuclear Medicine is a speciality that uses radioisotopes for the diagnosis or treatment of diseases and it is considered one of the best tools among the diagnostic modalities for detection of cancer. {sup 99m}Tc is one of the main isotopes for labelling antibodies and in Nuclear Medicine in general, due to its adequate physical properties, availability and low cost. Labelled monoclonal antibodies have shown promising results for diagnosis and therapy of cancer and their use has brought great experimental and clinical advances in the field of oncology. The main clinical applications of immunoscintigraphy with monoclonal antibodies are staging and evaluation of tumoral reappearance. The antibodies employed in this work were: OIR-CEA-1, a murine monoclonal antibody that acts directly against CEA expressed in several neoplasia in particular those from the gastrointestinal tract (colorectal cancer) and IOR-EGF/R3, a murine monoclonal antibody that binds to the external domain of EGF-R and it has been used in the diagnosis of tumors of epithelial origin. The objectives of this work were the development and optimization of the reduction and purification processes, the radiolabelling techniques and quality control procedures (radiochemical, immunoreactivity and cystein challenge) and imaging studies of monoclonal antibodies OIR-CEA-1 and IOR-EGF/R3, using the simple, fast and efficient method of direct labelling of the antibody with {sup 99m}Tc. The final results was the definition of the best conditions for the preparation of lyophilized reactive kits of OIR-CEA-1 and IOR- EGF/R3 for an efficient diagnostic application in Nuclear Medicine. The most adequate conditions for the labelling of the antibodies were: 1.0 mg Ab, 29 {mu}L MDP, 3.0 {mu}g Sn{sup 2+}, 1 mL of {sup 99m}Tc and 30 min. reaction time. With these conditions the labelling yield was always higher than 95% and the maximum activity of {sup 99m}Tc was about 2220 MBq (60 mCi). The evidences of the efficiency and

Comparative study of {sup 99}Mo/{sup 99m}Tc generators at base of synthesized gels starting from activation and fission {sup 99}Mo; Estudio comparativo de generadores {sup 99}Mo/{sup 99m}Tc a base de geles sintetizados a partir de {sup 99}Mo de activacion y de fision

Energy Technology Data Exchange (ETDEWEB)

Lopez M, I Z [UAEM, Paseo Colon esq. Paseo Tollocan, 50120 Toluca, Estado de Mexico (Mexico); Monroy G, F; Rivero G, T; Rojas N, P [ININ, Carretera Mexico -Toluca S/N, 52045 La Marquesa Ocoyoacac, Estado de Mexico (Mexico)

2007-07-01

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

Synthesis, characterization and biological evaluation of a novel "3 + 1" mixed ligand 99mTc complex having an aliphatic thiol as coligand.

Science.gov (United States)

Rey, A; Papadopoulos, M; Leon, E; Mallo, L; Pirmettis, Y; Manta, E; Raptopoulou, C; Chiotellis, E; Leon, A

2001-03-01

A novel "3 + 1" mixed ligand 99mTc complex with N,N-bis(2-mercaptoethyl)-N'N'-diethyl-ethilenediamine as ligand and 1-octanethiol as coligand was prepared and evaluated as potential brain radiopharmaceutical. Preparation at tracer level was accomplished by substitution, using 99mTc-glucoheptonate as precursor and a coligand/ligand ratio of 5. Under these conditions the labeling yield was over 80% and a major product with radiochemical purity >80% was isolated by HPLC methods and used for biological evaluation. Chemical characterization at carrier level was developed using the corresponding rhenium and 99gTc complexes. Results were consistent with the expected "3 + 1" structure and X-ray diffraction study demonstrated that the complex adopted a distorted trigonal bipyramidal geometry. All sulphur atoms underwent ionization leading to the formation of a neutral compound. Biodistribution in mice demonstrated early brain uptake, fast blood clearance and excretion through hepatobiliary system. Although brain/blood ratio increased significantly with time, this novel 99mTc complex did not exhibit ideal properties as brain perfusion radiopharmaceutical since brain uptake was too low.

Development, preparation and control of sup(99m)Tc or sup(113m)In labelled stannous hydroxide radiopharmaceuticals. Part of a coordinated programme on radiopharmaceuticals

International Nuclear Information System (INIS)

Alvarez Cervera, J.

1975-01-01

The preparation of different sup(99m)Tc and sup(113m)In radiopharmaceuticals using stannous chloride was investigated. Chemical and radiochemical procedures for the quality control of these preparations were studied. Toxicity and biological controls of the preparation were carried out. Procedures for the preparation and control of the following radiopharmaceuticals have been standardized by the authors; albumin macroaggregates labelled with sup(99m)Tc, sup(113m)In and other isotopes for lung scanning; albumin microspheres labelled with sup(99m)Tc for lung scanning; sup(99m)Tc or sup(113m)In-labelled stannous hydroxide colloid for liver scanning; sup(99m)Tc-stannous phytate for liver scanning; sup(99m)Tc-Sn-dextrose, a new radiopharmaceutical which has been proposed by the authors and is now used in Mexico for renal and cerebral scanning and sup(99m)Tc-Sn pyrophosphate and diphosphonate for bone scanning

Occupational exposure to {sup 99m}Tc and {sup 131}I in a radiopharmacy room

Energy Technology Data Exchange (ETDEWEB)

Valle, Bruna P.; Cunha, Kenya Dias da; Sa, Lidia Vasconcellos de; Souza, Wanderson; Santos, Maristela; Medeiras, Geiza; Conceicao, Cirilo S. [Universidade do Estado, Nova Friburgo, RJ (Brazil). Inst. Politecnico. Dept. de Modelagem Computacional], e-mail: brunapvalle@gmail.com, e-mail: kenya@ird.gov.br, e-mail: lidia@ird.gov.br, e-mail: wander@ird.gov.br, e-mail: mstela@ird.gov.br; Abrantes, Marcio Borges de [Centro de Medicina Nuclear Guanabara, Rio de Janeiro, RJ (Brazil)], e-mail: marcioabrantes@pop.com.br

2009-07-01

Brazil has about 310 nuclear medicine services and 90% of these services use Molybdenum/Technetium generators to prepare several radiopharmaceuticals to diagnostics; about 70% use also {sup 131}I for diagnosis and therapy. These radionuclides are associated to compounds in liquid form and during the manipulation to prepare and administer the patient dose some radioactive airborne particle can be generated. As consequence the workers can be exposed to airborne particles in the respirable fraction containing {sup 99m}Tc and {sup 131}I. The aim of this study is develop a simple and rapid method to verify if the exhaust systems installed in the SMN are efficient in preventing the inhalation of radionuclides airborne particles by workers. In order to estimate the occupational exposure a nuclear medicine service was selected and aerosol samples were collected using personal air sampler with a cyclone. The samples were analyzed using a germanium detector system and the {sup 99m}Tc and {sup 131}I average concentrations were obtained as 16,6 {+-} 14,34 mBq/m{sup 3} and 0.72 {+-} 0.36 mBq/m{sup 3}, respectively. It was not observed a correlation among air concentration and total activity processed in laboratory. These results show that the worker inhales airborne particles containing {sup 99m}Tc and {sup 131}I. (author)

The {sup 99m}Tc generator using poly zirconium chloride (PZC)

Energy Technology Data Exchange (ETDEWEB)

Wan Awang, Wan Anuar; Dahalan, Rehir; Kasim, Shaaban [Medical Technology Div., Malaysian Inst. for Nuclear Technology Research (MINT), Selangor (Malaysia)

1998-10-01

The {sup 99m}Tc generator system has been prepared using poly zirconium chloride (PZC) to replace alumina (Al{sub 2}O{sub 3}) as a adsorbent. The Mo-98 (MoO{sub 3}) was irradiated using our 1 MW TRIGA MARK II research reactor. The amount of Mo-99 adsorbed to the PZC has been studied and the yield from the elution was about 20%. (author)

The Use of Sodium Hypochlorite Solution for (n,γ99Mo/99mTc Generator Based on Zirconium-Based Material (ZBM

Directory of Open Access Journals (Sweden)

I. Saptiama

2015-08-01

Full Text Available The many problems in preparing fission product 99Mo led into this work to develop 99Mo/99mTc generator using neutron-irradiated natural MoO3 targets and, more specifically, to develop a zirconium-based material (ZBM for chromatography columns that have an adsorption capacity of more than 100 mg Mo/g ZBM. This paper reports our recent experiments in the use of sodium hypochlorite solution of various concentrations to improve the yield of 99mTc in performance of (n,γ99Mo/99mTc generators based on the ZBM. The synthesized ZBM was coated with tetraethyl orthosilicate for improving the hardness of the material. The adsorption of [99Mo]molybdate into ZBM was carried out by reacting ZBM into [99Mo]molybdate solution at 90°C to form ZBM-[99Mo] molybdate. ZBM-[99Mo]molybdate was then packed into generator column, then eluted with 10 × 1 mL of saline followed by 1 × 5 mL of NaOCl solution. The NaOCl solution concentrations used were 0.5%; 1%; 3%; and 5% for each column, respectively. This study resulted in a ZBM which has a 99Mo adsorption capacity of 167.5 ± 3.4 mgMo/g ZBM, as well as in a yield eluate of 99mTc of up to 70%, and the find that the optimum NaOCl concentration was 3%. The use of sodium hypochlorite solution affected 99Mo breakthrough. The higher sodium hypochlorite concentration used, the more 99Mo breaktrough exist on 99mTc eluate.

Influence of antiseptic on the impurities in the preparation of dimercaptosuccinic labelled with {sup 99m}Tc; Influence des antiseptiques sur la presence d'impuretes dans la preparation de l'acide dimercaptosuccinique marque au 99mTc

Energy Technology Data Exchange (ETDEWEB)

Metaye, T.; Rosenberg, T.; Perdrisot, R. [CHU de Poitiers, Service de medecine nucleaire et biophysique, 86 (France)

2010-07-01

Purpose: antiseptic solutions are used to disinfect the rubber stoppers on the bottles of radiopharmaceutical. Small amounts of these solutions can pass into the bottle when the cap is pricked to inject the {sup 99m}Tc. After finding in a patient a suboptimal labelling using biseptin, we studied the effect of various antiseptics on the presence of impurities in the preparation of the dimercaptosuccinic acid labelled with {sup 99m}Tc ({sup 99m}Tc-D.M.S.A.). Conclusions: We recommend using 70% isopropanol or modified alcohol Cooper instead of biseptin to disinfect the D.M.S.A. bottles caps. (N.C.)

Study to modify the elution system in a sup(99m)Tc generator

International Nuclear Information System (INIS)

Delgado S, Baldomero.

1979-01-01

The sup(99m)Tc generator is a system that allows us to obtain sup(99m)Tc through the radioactive desintegration of 99 Mo, a radionuclide absorbed in an alumine chromatographic column, the sup(99m)Tc extraction is accomplished by elution and the 99 Mo remains at the column. In this work we try to modify the elution procedure of the generator. At present after eluating the generator, it must be dried with air, in order to support the column in an oxidant atmosphere to avoid the reduction of the technetiate. This reduction causes a low yield of elution, since the reduced species of the technetium can not be eluated. The drying of the column with air complicates a little the elution procedure, and we look to simplify it, the employed methods to resolve the problem were: a) adding an oxidant agent to the elution saline solution, b) adsorbing an oxidant in the alumina chromatographic column, after that the 99 Mo was settled. In the case a) the used oxidant agents were KMnO 4 , K 2 Cr 2 O 7 , NaNo 2 , etc. At concentration rates of 10 -7 M the obtained yields in high activity generators were of the 25-30%. In the case b) variable amounts of a disolution of 2.5 mg/ml of K 2 CrO 4 were adsorbed, the obtained yields in high activity generators were about 85-90%, this second procedure was better, it lets us keep the column wet and it is not necessary to dry it with air, and in this way it can be carried out more easily and efficiently the elution procedure. (author)

In vivo regional quantitation of intrathoracic /sup 99m/Tc using SPECT: concise communication

International Nuclear Information System (INIS)

Osborne, D.; Jaszczak, R.; Coleman, R.E.; Greer, K.; Lischko, M.

1982-01-01

A whole-body single-photon emission computed tomographic system (SPECT) was used to quantitate the activities of a series of /sup 99m/Tc point sources in the dog's thorax and to evaluate attenuation of a uniform esophageal line source containing a known concentration of /sup 99m/Tc. A first-order attenuation correction and an empirically derived attenuation coefficient of 0.09 cm-1 were used in the SPECT analyses of the intrathoracic point sources. The relationship between SPECT measurements of multiple point-source activities and the same sources measured in air was linear over a range of 100 to 1000 muCi (slope 1.08; R2 coefficient of determination 0.97). These data are sufficiently accurate to allow an estimate of the regional activity of radiopharmaceutical in the dog's thorax and justify their use in experimental quantitation of regional pulmonary perfusion

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)

Diuretic 99mTc DTPA renography in assessment of renal function and drainage in infants with antenatally detected hydronephrosis.

Science.gov (United States)

Radulović, Marija; Pucar, Dragan; Jauković, Ljiljana; Sisić, Marija; Krstić, Zoran; Ajdinović, Boris

2015-12-01

The controversy over the postnatal management of infants with antenataly detected hydronephrosis (ANH) still exists. We presented the results of diuretic 99mTc diethylenetriamine pentaacetic acid (DTPA) renography in 30 infants with the antenatal diagnosis of unilateral renal pelvic dilatation. The aim of this study was to assess the renal function determined by the pattern of drainage and split renal function (SRF) on diuretic renography and to correlate these findings with anteroposterior pelvic diameter (APD) estimated by ultrasonography. A total of 30 infants with 60 renal units (RU) (25 boys and 5 girls, median age 6.0 months, range 2-24) presented with unilateral hydronephrosis on ultrasound in the newborn period, underwent DTPA diuretic renal scintigraphy (F+15 protocol). The median APD evaluated on perinatal ultrasound was 15 mm (range 5-30). The postnatal associated clinical diagnosis were pelviureteric junction obstruction (PUJ), simple hydronephrosis, megaureter, vesicoureteral reflux (VUR) and posterior urethral valves in 11, 10, 6, 2 and 1 infant, respectively. Images and Tmax/2 after diuretic stimulation on the background subtracted renographic curves were used as the criteria for classifying the drainage as good, partial, and poor or no drainage. The SRF was calculated with the integral method. Good drainage was shown in 36/60, partial drainage in 13/60 and poor or no drainage in 11/60 RU. The SRF > 40% was observed in 55/60 RU, with no RU showing SRF lower than 23.5%. In infants with severe ANH the obstruction was not excluded in 94.1%. Diuretic renography in antenatally detected hydronephrosis should be a useful tool in postnatal follow up, especially in differentiating nonobstructive hydronephrosis from obstructive. It is also importanat to assess and monitor the SRF. Our results suggest that even in the presence of partial or no drainage, SRF may not be significantly impaired.

Chemistry of /sup 99m/Tc labeling kits

International Nuclear Information System (INIS)

Srivastava, S.C.; Meinken, G.; Richards, P.

1976-01-01

Problems have been reported with the use of kit-produced /sup 99m/Tc radiopharmaceuticals. This study was undertaken to understand the chemistry involved in various stannous kit systems. The relation between Tc, tin, and the ligands used to complex the reduced Tc was investigated. It is concluded that for reliable performance, stannous kits should be prepared so that most of the tin is kept in the usable (reducing) form; a solution would be to use minimum tin and a large excess of complexing agent. Oxidation of the Tc complex to free pertechnetate is not a major problem in most kit systems. 5 figures

Radionuclide determination of individual kidney function in the treatment of chronic renal obstruction

International Nuclear Information System (INIS)

Belis, J.A.; Belis, T.E.; Lai, J.C.; Goodwin, C.A.; Gabriele, O.F.

1982-01-01

Differential radionuclide renal scans can be useful in the management of patients with chronic partial obstruction of 1 kidney. The /sup 99m/Tc diethylenetriaminepentaacetic acid perfusion scan can be used to assess glomerular blood flow. The 131 I orthoiodohippurate renal scan provides qualitative functional information from scintigrams and quantitative evaluation of effective renal plasma flow to each kidney, as well as a total excretory index. Sequential /sup 99m/Tc diethylenetriaminepentaacetic acid and 131 I orthoiodohippurate renal scans were used to assess individual renal function before and after surgical correction of unilateral chronic renal obstruction in 31 patients. The preservation of cortical perfusion on /supb 99m/Tc diethylenetriaminepentaacetic acid scans indicated that potential existed for partial recovery of renal function. Effective renal plasma flow and excretory index determined in conjunction with the 131 I orthoiodohippurate scans provided a quantitative assessment of preoperative renal function, an evaluation of the effect of surgery and a sensitive method for long-term evaluation of differential renal function. Correction of ureteropelvic junction obstruction usually resulted in improvement in unilateral renal function. Neither nephrolithotomy nor extended pyelolithotomy diminished renal function in the kidney subjected to an operation and often improved it. Patients with long-standing distal ureteral obstruction had the least improvement in renal function postoperatively

Dual-Labeled Near-Infrared/99mTc Imaging Probes Using PAMAM-Coated Silica Nanoparticles for the Imaging of HER2-Expressing Cancer Cells

Directory of Open Access Journals (Sweden)

Haruka Yamaguchi

2016-07-01

Full Text Available We sought to develop dual-modality imaging probes using functionalized silica nanoparticles to target human epidermal growth factor receptor 2 (HER2-overexpressing breast cancer cells and achieve efficient target imaging of HER2-expressing tumors. Polyamidoamine-based functionalized silica nanoparticles (PCSNs for multimodal imaging were synthesized with near-infrared (NIR fluorescence (indocyanine green (ICG and technetium-99m (99mTc radioactivity. Anti-HER2 antibodies were bound to the labeled PCSNs. These dual-imaging probes were tested to image HER2-overexpressing breast carcinoma cells. In vivo imaging was also examined in breast tumor xenograft models in mice. SK-BR3 (HER2 positive cells were imaged with stronger NIR fluorescent signals than that in MDA-MB231 (HER2 negative cells. The increased radioactivity of the SK-BR3 cells was also confirmed by phosphor imaging. NIR images showed strong fluorescent signals in the SK-BR3 tumor model compared to muscle tissues and the MDA-MB231 tumor model. Automatic well counting results showed increased radioactivity in the SK-BR3 xenograft tumors. We developed functionalized silica nanoparticles loaded with 99mTc and ICG for the targeting and imaging of HER2-expressing cells. The dual-imaging probes efficiently imaged HER2-overexpressing cells. Although further studies are needed to produce efficient isotope labeling, the results suggest that the multifunctional silica nanoparticles are a promising vehicle for imaging specific components of the cell membrane in a dual-modality manner.

Determination of radiochemical yield of {sup 99m}Tc radiopharmaceutical preparations using gamma counter and linear radiochromatography scanner

Energy Technology Data Exchange (ETDEWEB)

Martins, Patricia de A.; Moura, Rebeca G.; Shiki, Andressa M.; Fukumori, Neuza T.O.; Matsuda, Margareth M.N., E-mail: patyosborne@yahoo.com [Instituto de Pesquisas Energeticas e Nucleares (IPEN/CNEN-SP), Sao Paulo, SP (Brazil)

2013-07-01

The radiochemical purity (RCP) evaluation is a prerequisite for radiopharmaceuticals before the administration in patients. RCP is defined as the proportion of the total radioactivity in the product that is present in the specified chemical form. The most widely used techniques for RCP determination in radiopharmaceutical preparations are thin layer chromatography (TLC-Al), instant thin layer chromatography (ITLC-SG) and paper chromatography (PC). These techniques combined with radioactivity detection are one of the most important tools in the RCP of the radiopharmaceutical compounds. Several methods are used for the determination of the spatial distribution of radioactivity on the strips. The aim of this study was to compare two methods for radioactivity measurement in the determination of RCP in {sup 99m}Tc radiopharmaceuticals using gamma counter and linear radiochromatography scanner. Lyophilized radiopharmaceuticals were labeled with {sup 99m}Tc. The analysis was carried out using TLC-Al and high performance thin layer chromatography (HPTLC-Cellulose) sheets, ITLC-SG and 3MM Whatman PC. The radioactivity distribution was determined by counting each strip during 1 minute in a radiochromatography TLC scanner. For comparison, the strips were cut into small pieces and each one was separately measured in a gamma-counter during 0.20 minutes in 70-210 KeV {sup 99m}Tc window. USP 36 and FDA specify that not less than 90% of the total radioactivity must be in the spot corresponding to {sup 99m}Tc labeled compound. In conclusion, the procedure for RCP determination of ALBUMINA-TEC, DEX500-TEC, ECD-TEC, MACRO-TEC and MIBI-TEC can be faster using radiochromatography. (author)

Use of pyrophosphate-/sup 99m/Tc in diagnosis of malignant tumors of bones

Energy Technology Data Exchange (ETDEWEB)

Kasatkin, Yu N; Purizhanskii, I I; Survila, Z P; Agranat, V Z; Korsunskii, V N

1976-10-01

Pyrophosphate-/sup 99m/Tc was administered intravenously in a dose of 0.05 to 0.08 mCi per 1 kg body weight of the patient. Studies were made after 4, 6, and 24 hours with fixed and movable detectors. During investigations a gamma-chamber magnetic memory and a 4096-channel analyzer were also used. A quantitative processing of the material was made. The authors determined distribution of the preparation in normal and pathological bone tissue. A total of 142 patients with tumors of the bone tissue were examined; 858 radioisotope measurements were made. An analysis of accumulation of pyrophosphate-/sup 99m/Tc in primary osteogenic tumors in systemic affections of the bones and bone metastases was made. There is a relation between the concentration of the radiopharmaceutical preparation and the morphological structure of the tumor. Reduction in the accumulation of the radioactive indicator took place after radiation and medicinal effect, this made it possible to judge the regression of the tumor.

Labelling of bilirubin with /sup 99m/Tc and pharmacokinetic behavior

International Nuclear Information System (INIS)

Kaempfer, I.; Schneider, G.; Blottner, A.; Deckart, H.; Staedtisches Klinikum Berlin-Buch

1982-01-01

The yield of the bilirubin labelling with /sup 99m/Tc amounted to 97%. The labelled complex has been stable for 24 hours with the pH range 2-7.5. As evidenced in animal experiments the labelled bilirubin is probably subjected to natural degradation processes. Side effects could not be noticed. A disadvantage seems to be the slow transfer of /sup 99m/Tc-bilirubin from the hepatic cell to the biliary capillary

Our experience with B.A.R.C. sup(99m)Tc generator

International Nuclear Information System (INIS)

Padmanabhan, V.; Pandurengan, N.; Lakshmanan, A.V.

1980-01-01

sup(99m)Tc has been eluted from its parent 99 Mo by solvent extraction method. It is pointed out that there is considerable variation in the eluted activity in day to day practice and any administration of the isotope to the patient must be measured in an isotope calibrator. Operator dose levels have been recorded which are quite within the permissible levels. (auth.)

99MTC Alpha-Fetoprotein: A Novel, Specific Agent for the Detection of Human Breast Cancer

National Research Council Canada - National Science Library

Line, Bruce

1998-01-01

.... We have demonstrated that technetium-99m radiolabeled human alpha-fetoprotein (99mTc AFP) localizes in human breast cancer cells in-vivo, most likely concentrating in breast cancer cells due to a specific receptor not found in normal adult breast tissue...

99MTC Alpha-Fetoprotein: A Novel, Specific Agent for the Detection of Human Breast Cancer

National Research Council Canada - National Science Library

Line, Bruce

1999-01-01

.... We have demonstrated that technetium-99m radiolabeled human alpha-fetoprotein (99mTc AFP) localizes in human breast cancer cells in-vivo, most likely concentrating in breast cancer cells due to a specific receptor not found in normal adult breast tissue...

WE-AB-204-12: Dosimetry at the Sub-Cellular Scale of Auger-Electron Emitter 99m-Tc in a Mouse Single Thyroid Follicle Model

Energy Technology Data Exchange (ETDEWEB)

Taborda, A; Benabdallah, N; Desbree, A [Institut de Radioprotection et de Surete Nucleaire, Fontenay-aux-roses (France)

2015-06-15

Purpose: To perform a dosimetry study at the sub-cellular scale of Auger-electron emitter 99m-Tc using a mouse single thyroid cellular model to investigate the contribution of the 99m-Tc Auger-electrons to the absorbed dose and possible link to the thyroid stunning in in vivo experiments in mice, recently reported in literature. Methods: The simulation of S-values for Auger-electron emitting radionuclides was performed using both the recent MCNP6 software and the Geant4-DNA extension of the Geant4 toolkit. The dosimetric calculations were validated through comparison with results from literature, using a simple model of a single cell consisting of two concentric spheres of unit density water and for six Auger-electron emitting radionuclides. Furthermore, the S-values were calculated using a single thyroid follicle model for uniformly distributed 123-I and 125-I radionuclides and compared with published S-values. After validation, the simulation of the S-values was performed for the 99m-Tc radionuclide within the several mouse thyroid follicle cellular compartments, considering the radiative and non-radiative transitions of the 99m-Tc radiation spectrum. Results: The calculated S-values using MCNP6 are in good agreement with the results from literature, validating its use for the 99m-Tc S-values calculations. The most significant absorbed dose corresponds to the case where the radionuclide is uniformly distributed in the follicular cell’s nucleus, with a S-value of 7.8 mGy/disintegration, due mainly to the absorbed Auger-electrons. The results show that, at a sub-cellular scale, the emitted X-rays and gamma particles do not contribute significantly to the absorbed dose. Conclusion: In this work, MCNP6 was validated for dosimetric studies at the sub-cellular scale. It was shown that the contribution of the Auger-electrons to the absorbed dose is important at this scale compared to the emitted photons’ contribution and can’t be neglected. The obtained S

Production optimization of {sup 99}Mo/{sup 99m}Tc zirconium molybate gel generators at semi-automatic device: DISIGEG

Energy Technology Data Exchange (ETDEWEB)

Monroy-Guzman, F., E-mail: fabiola.monroy@inin.gob.mx [Instituto Nacional de Investigaciones Nucleares, Carretera Mexico-Toluca S/N, La Marquesa, Ocoyoacac, 52750, Estado de Mexico (Mexico); Rivero Gutierrez, T., E-mail: tonatiuh.rivero@inin.gob.mx [Instituto Nacional de Investigaciones Nucleares, Carretera Mexico-Toluca S/N, La Marquesa, Ocoyoacac, 52750, Estado de Mexico (Mexico); Lopez Malpica, I.Z.; Hernandez Cortes, S.; Rojas Nava, P.; Vazquez Maldonado, J.C. [Instituto Nacional de Investigaciones Nucleares, Carretera Mexico-Toluca S/N, La Marquesa, Ocoyoacac, 52750, Estado de Mexico (Mexico); Vazquez, A. [Instituto Mexicano del Petroleo, Eje Central Norte Lazaro Cardenas 152, Col. San Bartolo Atepehuacan, 07730, Mexico D.F. (Mexico)

2012-01-15

DISIGEG is a synthesis installation of zirconium {sup 99}Mo-molybdate gels for {sup 99}Mo/{sup 99m}Tc generator production, which has been designed, built and installed at the ININ. The device consists of a synthesis reactor and five systems controlled via keyboard: (1) raw material access, (2) chemical air stirring, (3) gel dried by air and infrared heating, (4) moisture removal and (5) gel extraction. DISIGEG operation is described and dried condition effects of zirconium {sup 99}Mo- molybdate gels on {sup 99}Mo/{sup 99m}Tc generator performance were evaluated as well as some physical-chemical properties of these gels. The results reveal that temperature, time and air flow applied during the drying process directly affects zirconium {sup 99}Mo-molybdate gel generator performance. All gels prepared have a similar chemical structure probably constituted by three-dimensional network, based on zirconium pentagonal bipyramids and molybdenum octahedral. Basic structural variations cause a change in gel porosity and permeability, favouring or inhibiting {sup 99m}TcO{sub 4}{sup -} diffusion into the matrix. The {sup 99m}TcO{sub 4}{sup -} eluates produced by {sup 99}Mo/{sup 99m}Tc zirconium {sup 99}Mo-molybdate gel generators prepared in DISIGEG, air dried at 80 Degree-Sign C for 5 h and using an air flow of 90 mm, satisfied all the Pharmacopoeias regulations: {sup 99m}Tc yield between 70-75%, {sup 99}Mo breakthrough less than 3 Multiplication-Sign 10{sup -3}%, radiochemical purities about 97% sterile and pyrogen-free eluates with a pH of 6. - Highlights: Black-Right-Pointing-Pointer {sup 99}Mo/{sup 99m}Tc generators based on {sup 99}Mo-molybdate gels were synthesized at a semi-automatic device. Black-Right-Pointing-Pointer Generator performances depend on synthesis conditions of the zirconium {sup 99}Mo-molybdate gel. Black-Right-Pointing-Pointer {sup 99m}TcO{sub 4}{sup -} diffusion and yield into generator depends on gel porosity and permeability. Black

Evaluation of the influence of pH in the efficiency of the {sup 99}Mo-{sup 99m}Tc at basis of zirconium molybdate; Evaluacion de la influencia de pH en la eficiencia del generador {sup 99}Mo-{sup 99m}Tc a base de molibdato de zirconio

Energy Technology Data Exchange (ETDEWEB)

Diaz A, L V

2003-07-01

The {sup 99m}Tc are the radionuclide more used in the nuclear medicine, it is used for diagnostic and therapy, and he is commonly takes place by means of a generator {sup 99} Mo-{sup 99m}Tc, using molybdenum ({sup 99}Mo) product of the fission of the uranium, adsorbed over alumina. This generator imposes the use of high activities you specify of {sup 99} Mo, as well as of complex processes of separation of the one {sup 99} Mo, generating important quantities of radioactive waste of medium activity. As well as, the production of these generators, demands the use of reactors of great capacity that Mexico not it possesses, in such a way that, presently work is carried out a generator of {sup 99} Mo- {sup 99m} Tc, in the one which {sup 99} Mo taken place by the reaction {sup 98} Mo(n, {gamma}) {sup 99} Mo that it was part from a gel to base is used of molybdate and zirconium. It was found, therefore, to produce a generator {sup 99} Mo- {sup 99m}Tc with the help of gels of zirconium and molybdates with the same characteristics of quality and purity that those obtained by the one traditional generator and that it can be carried out under the conditions technical-economics prevailing in Mexico. Specifically, this work has been focused to the study of the effect caused by the variation of the one p H in the solutions of ZrOCl{sub 2} * 8H{sub 2}O (zirconil) and of molybdates, of the relationships molars zirconium : molybdenum (Zr:Mo), as well as the effect of the concentration variation, time of preparation and consequently p H of the ZrOCl{sub 2} * 8H{sub 2}O in the synthesis of the gel zirconium - {sup 99} molybdenum, on the efficiency of the generator and the quantity of {sup 99} Mo presents in the {sup 99m} Tc taken place by this means. The gel used for the production of {sup 99m}Tc will possess a discharge efficiency of recovery of {sup 99m}Tc and a contained first floor of pollutants, in particular smaller to 0.015% of {sup 99} Mo, main source of impurity radionuclide

Massive Machine-Type Communication (mMTC) Access with Integrated Authentication

DEFF Research Database (Denmark)

Pratas, Nuno; Pattathil, Sarath; Stefanovic, Cedomir

2017-01-01

We present a connection establishment protocol with integrated authentication, suited for Massive Machine-Type Communications (mMTC). The protocol is contention-based and its main feature is that a device contends with a unique signature that also enables the authentication of the device towards...... the network. The signatures are inspired by Bloom filters and are created based on the output of the MILENAGE authentication and encryption algorithm set, which is used in the authentication and security procedures in the LTE protocol family.We show that our method utilizes the system resources more...

Comparison of film sensitivity for sup(99m)Tc gamma-rays

International Nuclear Information System (INIS)

Kojima, Kazuhiko; Katayama, Masaharu; Hisada, Kinichi.

1975-01-01

Recently a new method of γ-ray imaging by holography has been studied at several nuclear medical laboratories. The holography is of a very simple. An axis Fresnel zone plate made of lead (2 mm thickness) is placed between the γ-ray source and a detector, and its shadow is recorded as a hologram. The hologram obtained is illuminated by parallel beams of He-Ne laser (6328 A), and an image of the radioisotope distribution in the object is reconstructed by diffraction. The better the resolution of the shadow hologram, the better are the reconstructed images obtained. For this reason the detector for recording the γ-ray hologram must be selected carefully. Three kinds of medical X-ray film were used as detectors for holograms to compare film sensitivity. Generally these medical X-ray films have poor sensitivity to γ-rays of sup(99m)Tc. In order to intensify the film sensitivity for γ-rays of sup(99m)Tc, combinations of six kinds of intensifying screens were studied. Good film sensitivity was obtained by RP (Kodak Co.) film combined with a KZ-S fluorescent intensifying screen. The fluorescent screen was better than fluorometallic screens with similar properties. Using this film-screen combination, shadow holograms could be recorded for 2-3 minutes and images could be optically reconstructed. (auth.)

Effects of Momordica charantia on osmotic fragility and label red blood cells and plasmatic protein with 99m-Tc in vitro

Energy Technology Data Exchange (ETDEWEB)

Magnata, Simey S.L.P. [Pernambuco Univ., Recife, PE (Brazil). Dept. de Energia Nuclear]. E-mail: sfmagnata@terra.com.br; Correia, Marilia B.L.; Brandao, Jose Odinilson C.; Souza, Grace M.L.; Catanho, Maria Teresa J.A. [Pernambuco Univ., Recife, PE (Brazil). Dept. de Biofisica e Radiobiologia; Terra, Daniele A.; Amorim, Lucia F. [Rio Grande do Norte Univ., Natal, RN (Brazil). Dept. de Fisiologia

2005-07-01

The use of natural products in the treatment physiopathology awaken the interest in the inquiry of the action mechanisms. The Momordica charantia, Melao de Sao Caetano, is used in the Caribbean and Orient for the diseases as stomatitis, cancer and diabetes. This work aims to verify the effect of the Momordica charantia's aqueous extract leaves on osmotic fragility and on labeling red blood cells (RBC) and plasmatic proteins with {sup 99m}Tc in vitro. To evaluate the osmotic fragility, samples of heparinized blood (500 mL) was incubed for 1 hour with brut extract (500 mL) in different concentrations (0; 10; 50 and 100% v/v); after centrifugation, the RCB were submitted the incubation (1 hour) with a gradient of NaCl (0;0,1;0,25;0,4;0,7 and 0.9%), the OD of supernatant was determined. With regards to label red blood cells and plasmatic proteins with {sup 99m}Tc in vitro was carried out by incubating of anticoagulant whole blood (500 mL) for 1 hour with brut extract (500 mL) in different concentrations (0; 10; 50 and 100% v/v). A stannous chloride solution of 1,2 {mu}g/mL was added the incubation for 60 minutes. After this the {sup 99m}Tc (3,7 MBq) was added and the incubation was continued for another 10 minutes. Those were centrifuged, precipitated with trichloroacetic acid 5% and mensured in a counter. The results shows that with regard to osmotic fragility, only the extract in the concentration of 100% provoked hemolysis. The Momordica charantia's extract is an agent who modify the fixation of {sup 99m}Tc in red blood cells. The results show with regard to osmotic fragility, only the extract in the quantity 100% provoked hemolysis. It is concluded that the Momordica charantia's extract is an agent who unchains the cellular fragility and {sup 99m}Tc fixation, showing a reduction effect. (author)

/sup 99m/Tc labelled ulcer avid agents

International Nuclear Information System (INIS)

Scopinaro, F.; Linari, G.; Baldieri, M.; Liberatore, M.; Corti, E.; Signori, C.

1986-01-01

Sulfated oligosaccharides have some interesting pharmacological properties: they are anticoagulants and protect the ulcerative areas of epithelia by precipitating over ulcers together with exudative proteins. Some sucralfate labelling methods using /sup 75/Se, /sup 111/In, /sup 99m/Tc-albumin and /sup 99m/Tc-DTPA have been reported. Only the /sup 99m/Tc-sucralfate has, at present, the requisites to be used as an ulcer-seeking agent. The aim of this study were: (a) to introduce a simple and easy-to-repeat method for the labelling of sucralfate with /sup 99m/Tc-DTPA; (b) to demonstrate that it is possible to label the sucrose octasulfate directly with /sup 99m/Tc without the aid of other ligands (e.g. DTPA)

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

99mTc-3PRGD2 Scintimammography in Palpable and Nonpalpable Breast Lesions

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Lin Liu

2014-07-01

Full Text Available The aim of this study was to explore the diagnostic performance of 99mTc-3(poly-(ethylene glycol,PEG4-RGD2 (99mTc-3PRGD2 scintimammography (SMM in patients with either palpable or nonpalpable breast lesions and compare SMM to mammography to assess the possible incremental value of SMM in breast cancer detection. We also investigated the αvβ3 expression in malignant and benign breast lesions. Ninety-four patients with 110 lesions were included in this study. Mammograms were evaluated according to the Breast Imaging Reporting and Data System (BI-RADS by a specialized imaging radiologist. Prone SMM was performed 1 hour after injection of 99mTc-3PRGD2. Scintigraphic images were interpreted independently by two experienced nuclear medicine physicians using a three-point system, and the kappa value was calculated to determine the interreader agreement. The McNemar test was used to compare SMM and mammography with respect to sensitivity, specificity, and accuracy. Diagnostic values for breast cancer detection were evaluated for each lesion. Immunohistochemistry was performed to evaluate integrin αvβ3 expression. Histopathology revealed 46 malignant lesions and 64 benign lesions. The overall sensitivity, specificity, accuracy, positive predictive value, and negative predictive value of SMM were 83%, 73%, 77%, 69%, and 85%, respectively. The kappa value between the two reviewers was 0.63. The diagnostic values of SMM were higher than those of mammography in evaluating overall breast lesions. A sensitivity of 91% was achieved when SMM and mammography results were combined with 60% of all false-negative mammography findings classified as true-positive results by SMM. Integrin αvβ3 expression was positively identified using SMM imaging. SMM is a promising tool to avoid unnecessary biopsies when used in addition to mammography and can be used to image αvβ3 expression in breast cancer with good image quality.

A modified method for the in vivo labeling of red blood cells with /sup 99m/Tc: concise communication

International Nuclear Information System (INIS)

Callahan, R.J.; Froelich, J.W.; McKusick, K.A.; Leppo, J.; Strauss, H.W.

1982-01-01

The rate of incorporation of /sup 99m/Tc into red blood cells pretinned in vivo was measured by collecting blood samples in stannous DTPA solution, which served as a competing ligand for /sup 99m/Tc. This collection technique permitted a measurement of high-affinity red-cell labeling efficiency at the instant of sampling. At 0.5 min after injection only 62% of technetium is tightly bound to the red cell; this rises to 94.5% at 10 min. Based on the graded labeling of the red cells, the in vivo labeling procedure was modified by isolating pertechnetate and red blood cells tinned in vivo in a syringe during the first 10 min of labeling. The pertechnetate is thus prevented from distributing to extravascular compartments, and 90% of the injected /sup 99m/Tc is firmly bound to red blood cells at the time of injection. In a series of 23 patients, seven were tested with the in vivo method and seven with the modified in vivo method, and nine patients were tested with each method on separate occasions. A decrease in gastric activity and improved image quality were found with the modified method compared with the standard method of in vivo red-cell labeling

Simultaneous 99mTc and 123I dual-isotope brain striatal phantom single photon emission computed tomography: validation of 99mTc-TRODAT-1 and 123I-IBZM simultaneous dopamine system brain imaging.

Science.gov (United States)

Kao, Pan-Fu; Wey, Shiaw-Pyng; Yang, An-Shoei

2009-11-01

[2[[2-[[[3-(4-chlorophenyl)-8-methyl-8-azabicyclo[3,2,1]-oct-2-yl]-methyl](2-mercaptoethyl)-amino]ethyl]amino]ethanethiolato(3-)-N2,N2',S2,S2]oxo-[1R-exo-exo)])-[99mTc]-technetium (99mTc-TRODAT-1) and 123I-iodobenzamide (123I-IBZM) are radiotracers for brain dopamine pre- and postsynaptic neuron imaging. The purpose of this study was to evaluate imaging parameters and crossed energy interference using simultaneous single photon emission computed tomography (SPECT) 99mTc and 123I data acquisition. A five-compartment brain striatal phantom was filled with 99mTc and/or 123I radioactive solutions with different striatal-to-background ratios, ranging from 3:1 to 9:1. SPECT data were acquired with energy window settings of 15% for the centered window at 140 keV for 99mTc and a 10% asymmetric window at 159 keV for 123I. The experiments were carried out using either individual (99mTc or 123I only) or both radionuclides. The striatal-to-background ratios and energy crossed interference between 99mTc and 123I were calculated. The phantom SPECT images demonstrated that the energy crossed interferences from 123I to 99mTc, and vice versa, were 22 +/- 12.4% and 0.4 +/- 1.0%, respectively. A net interference of 7.1 +/- 4.0% for the counts in the 15% centered 99mTc window can be expected from 123I and a net interference of 1.6 +/- 3.3% for the counts in the 10% asymmetric 123I window was derived from 99mTc. The correlation of striatal-to-background ratios between single isotope and simultaneous dual-isotope was excellent (R2 = 0.99). The imaging parameters used in this simultaneous dualisotope SPECT imaging could be used in future clinical practice for imaging patients with movement disorders by using 99mTc-TRODAT-1 and 123I-IBZM. The striatal-to-background ratios were not affected by the crossed interference between 99mTc and 123I.

Simultaneous 99mTC and 123I Dual-Isotope Brain Striatal Phantom Single Photon Emission Computed Tomography: Validation of 99mTC-Trodat-1 and 123I-IBZM Simultaneous Dopamine System Brain Imaging

Directory of Open Access Journals (Sweden)

Pan-Fu Kao

2009-11-01

Full Text Available [2[[2-[[[3-(4-chlorophenyl-8-methyl-8-azabicyclo[3,2,1]-oct-2-yl]-methyl](2-mercaptoethylamino]ethyl]amino]ethanethiolato(3--N2,N2′,S2,S2]oxo-[1R-exo-exo]-[99mTc]-technetium (99mTc-TRODAT-1 and 123I-iodobenzamide (123I-IBZM are radiotracers for brain dopamine preand postsynaptic neuron imaging. The purpose of this study was to evaluate imaging parameters and crossed energy interference using simultaneous single photon emission computed tomography (SPECT 99mTc and 123I data acquisition. A five-compartment brain striatal phantom was filled with 99mTc and/or 123I radioactive solutions with different striatal-to-background ratios, ranging from 3:1 to 9:1. SPECT data were acquired with energy window settings of 15% for the centered window at 140 keV for 99mTc and a 10% asymmetric window at 159 keV for 123I. The experiments were carried out using either individual (99mTc or 123I only or both radionuclides. The striatal-to-background ratios and energy crossed interference between 99mTc and 123I were calculated. The phantom SPECT images demonstrated that the energy crossed interferences from 123I to 99mTc, and vice versa, were 22 ± 12.4% and 0.4 ± 1.0%, respectively. A net interference of 7.1 ± 4.0% for the counts in the 15% centered 99mTc window can be expected from 123I and a net interference of 1.6 ± 3.3% for the counts in the 10% asymmetric 123I window was derived from 99mTc. The correlation of striatal-to-background ratios between single isotope and simultaneous dual-isotope was excellent (R2 = 0.99. The imaging parameters used in this simultaneous dual-isotope SPECT imaging could be used in future clinical practice for imaging patients with movement disorders by using 99mTc-TRODAT-1 and 123I-IBZM. The striatal-to-background ratios were not affected by the crossed interference between 99mTc and 123I.

Phenolic aminocarboxylate chelates of 99mTc as hepatobiliary agents.

Science.gov (United States)

Hunt, F C; Maddalena, D J; Wilson, J G; Bautovich, G J

1986-01-01

A series of alkyl- and halogen-substituted derivatives of ethylenediamine di[o-hydroxyphenylacetic acid] (EDDHA) and N,N'-bis[2-hydroxybenzyl] ethylenediamine N,N'-diacetic acid (HBED) were complexed with 99mTc and their biodistribution was determined in rats. All complexes displayed substantial hepatobiliary excretion; of each series, 99mTc-Br-EDDHA and 99mTc-di-Cl-HBED had the maximum amount in the gastrointestinal tract. Scintigraphic studies of 99mTc-Cl-EDDHA in dogs revealed prompt imaging of the liver followed by imaging of the gall bladder as the complex was excreted into the bile.

Functional studies of the oesophagus with sulfur-colloid of sup(99m)Tc and gamma-camera

International Nuclear Information System (INIS)

Veiga-Fernandes, F.; Costa, P.M.; Pinheiro, M.F.; Guerreiro, D.

1982-01-01

A scintiscanning technique which allows sequential detection and quantification of gastro-oesophageal reflux (GER), and study of the oesophageal emptying of a liquid and semi-solid food is presented. At first patients swallowed 5 ml of water containing 1 mCi sup(99m)Tc sulfur-colloid and oesophageal activity is recorded from an anterior view by a gamma-camera. Then, patients ingest 300 ml of water that clear the oesophagus and fill up the stomach. GER index is calculated according to the formula GER = (Ae - Ab)/Ag) x 100, where Ae is the activity in the oesophagus; Ab, is the background activity; and Ag is the gastric activity. GER index presented corresponds to a median of three determinations in upright, supine and supine position with abdominal pressure of 4 kilos. The oesophageal transit time of a semi-solid food in upright and supine position is registered 5 minutes after GER studies through two areas of interest which are positioned: one in the superior third and the other in the inferior third of the oesophagus. Normal GER reflux index was, 0.84 +- 0.37 in the upright position; 0.87 +- 0.43 in the supine position; and 0.90 +- 0.56 in the supine position plus abdominal pressure

Role of 99mTc labelled GHA in post treatment evaluation of brain tumours

International Nuclear Information System (INIS)

Choudhury, P.

2003-01-01

Full text: Introduction: Biochemical investigations have a major role to play in the management of primary brain tumours. It is well known that major biochemical changes occur during cancerous transformation including changes in the energy metabolism of the cell. Changes take place in terms of utilization of glucose and other substrates, protein synthesis and expression of antigens and receptors. Changes also take place in disruption of transport mechanisms across cell membranes and other physiological boundaries like blood brain barrier. In the management of primary brain tumours positron emitting tracers have an undisputed role and the role of cationic tracers like Thallium-201, 99m-Tc MIBI and 99m-Tc tetrofosmin has been cited as an alternative to positron tracers in neuro oncology. It must be borne in mind that the cationic tracers are expensive to procure and facilities for positron emission tomography are not available in most of the developing countries. Tc-99m GHA Brain Imaging: Keeping in view the above, a cheaper alternative for PET radio tracers was evaluated. We have so far conducted more than 100 brain SPECT studies, using Tc-99m Glucoheptonic acid (GHA), in 60 patients of brain tumour, both at the time of their diagnosis, as well as after treatment during the follow-up period. Tc-99m Glucoheptonic acid (GHA) is a chemical glucose analogue. Avid concentration of the radiopharmaceutical was noted in viable tumor tissue in the SPECT images done one hour after injection of 740 MBq of 99m-Tc GHA. This was subsequently confirmed by histopathological examination in patients undergoing re-surgery for residual disease or follow up and clinical correlation in patients under remission. Avid tracer concentration was also well demonstrated in recurrent disease (proven by clinical examination, histopathology and/or magnetic resonance imaging (MRI). No significant tracer uptake was seen in areas of radiation induced necrosis. Non-specific uptake in the tumor bed was

Radiation-hygienic assessment of sup(99m)Tc generators

International Nuclear Information System (INIS)

Panfilova, N.P.; Kochetova, G.P.; Zol'nikova, N.I.; Trunov, B.V.

1985-01-01

Radiation-hygienic evaluation of labour conditions and degree of medical personnel irradiation during operation of short-lived radionuclide generators (of the activity 12950MBq, 18500 MBq) in radionuclide diagnosis has been made. For the purpose the exposure dose rate in working places from sup(99m)Tc generator was determined. Simultaneously, operation by operation timing at all the sta.oes of technological process is carried out. Measurements are realized at four levels (head, breast, pelvis, hands). It is shown, that total personnel dose at the first day of operation with generator constitutes 8.64 mR to hands, 1.12 mR to head, 2.333 mR to breast, 1.309 mR to pelvis

A case control study to find out child feeding practices responsible for severe acute malnutrition among under-five children admitted in MTC at a tertiary care centre, Bikaner, Rajasthan

Directory of Open Access Journals (Sweden)

Kavita Choudhary

2014-12-01

Full Text Available Introduction: There is no significant difference between NFHS II &III with respect to under- nutrition data but Gross national income has increased many times, so poverty and unavailability of food alone cannot be the only reasons of under- nutrition. Under-nutrition is the result of many interrelated factors such as poverty, insufficient household food security, inadequate health services, poor maternal and child care practices and inadequate water and sanitation. For communities with a high prevalence of under- nutrition, it may take years or even decades before all of these factors can be addressed. Aims and Objectives:  to find out child feeding practices responsible for severe acute malnutrition among Under-five Children and to recommend a Community Action Plan based on Positive Deviance Approach to deal with under-nutrition quickly, affordably and sustainably in a culturally acceptable manner. Materials & Methods: Study design: Matched Case Control study. Sample size: 143 cases and age, socio-economic status matched 143 controls. Study place: MTC and Immunization clinic. Study Duration: May, 2013- May, 2014. Study Tool and Data Collection: Semi-structured pre-tested questionnaire. Data analysis: with help of SPSS16 (Mean, SD, Proportion, odds ratio. Results: Strong positive association was found between duration of exclusive breast feeding(both shorter and longer, prelacteals, diluted milk as weaning food, bottle feeding, giving excess milk and less solid protein diet, not able to recognize cue of hunger by mother, lack of demand feeding, and severe acute malnutrition. Conclusion: Not any nutritional programme can help in preventing SAM unless we motivate the mothers for good child feeding and rearing practices. This can be achieved by identification of the Positive Deviant mothers from the same community and SES, who can motivate the mothers of SAM children and can practically demonstrate positive child feeding practices in a culturally

Evaluation of sup(99m)Tc-albumin dilution curve with simultaneous injection of sup(99m)Tc- and 131I-albumins

International Nuclear Information System (INIS)

Kinoshita, Masahiko; Kato, Shotaro; Motomura, Masakazu; Kawakita, Seiichi

1979-01-01

A critical comparison of radiocardiograms with sup(99m)Tc- and 131 I-albumins was made to determine whether or not sup(99m)Te-albumin can be used as a tracer for measuring blood volume (BV) and cardiac output (CO). Simultaneous injection of both isotopes was given to twenty-two patients to obtain radiocardiograms for each by means of a single scintillation counter with two pulse height analyzers. Such method allows for the determination of the energy levels for both sup(99m)Tc and 131 I. The radiocardiographic pattern was somewhat different between sup(99m)Tc- and 131 I-radiocardiograms: The ratio of left to right peak height was 16% on the average lower in the sup(99m)Tc-radiocardiogram than in the 131 I-one. The reason for the lower ratio is explained by greater absorption of sup(99m)Tc-radioactivity within the soft tissue interposing between the scintillation probe and heart. The values for sup(99m)Tc-derived blood volume were 7.4% on the average larger than those for 131 I-derived blood volume (p less than 0.01), although the correlation was excellent (r = 0.98 p less than 0.01). There was no systemic difference between cardiac output determined by sup(99m)Tc- and 131 I-albumins since the overestimation of blood volume can compensate for the underestimation of CO/BV by sup(99m)Tc-study. In view of its rapid extravasation, sup(99m)Tc-albumin is not so appropriate tracer for accurate measurements of BV and CO/BV, although it may be used for measurement of cardiac output. (author)

The diagnostic value of monoclonal antibody scan (leucoscan) compared with 99mTc MDP bone scan and Ga 67 in diagnosing bone and joint infection

International Nuclear Information System (INIS)

Koukouraki, S.I.; Velidaki, A.; Prassopoulos, V.; Karkavitsas, N.; Vavouranakis, H.; Hatjipavlou, A.

2002-01-01

Full text: Nowadays different radiopharmaceuticals have been developed as 99mTc MDP, 67Ga citrate, 111In oxine- and 99mTc HMPAO labeled leucocytes for the accurate localization of bone/joint infection, but all of them have limitations that encouraged the search of new agents characterized from high and early uptake in infectious/inflammatory tissues, low toxicity and no accumulation in non inflamed tissues. The purpose of this study is to compare the diagnostic value of a 99mTc labeled antigranulocyte Fab' fragment (Leucoscan) with 99mTc MDP bone scan and 67 Ga. The monoclonal antibody, Leucoscan, is an IgG murine Fab' fragment directed against a NCA-90 epitope located on the surface of granulocytes. 45 patients with suspected bone and joint infection (18 total hip prosthesis, 4 knee prosthesis, 8 vertebral infection and 15 long bones) were included in this study. All patients underwent conventional Rx, bone scan, 67Ga scan and Leucoscan. Three phase 99mTc MDP bone scan and 67Ga scan were performed using standard procedures. For Leucoscan the antibody was labeled with 25 mCi of 99mTc and was infected intravenously over 30 seconds. Ten minutes planar images were taken 1 h and 2 hrs p.i using a GE Millennium γ camera provided with a LEGP collimator. Images were evaluated as score 1 (no abnormal uptake), score 2 (probably positive), score 3 (definitely infected) according the intensity of abnormally increased uptake. Results were compared with 99mTc MDP bone scan and 67Ga scans. The final diagnosis was given by the surgical verification with histopathology or culture. All 45 patients had pathologic proof of presence/absence of bone and joint infection. 36/45 were positive for bone or joint infection and 9/45 were negative.30/36 patients with surgically proven bone and joint infection had true positive Leucoscan, 26/36 had true positive MDP bone scan and 20/36 true positive 67Ga scan. Nine out of 9 patients with proven absence of inflammation had true negative

Evaluation of aptamers labelled with {sup 99m}Tc for identification of Staphylococcus aureus bacteria; Avaliacao de aptameros marcados com {sup 99m}Tc para identificacao de focos infecciosos de Staphylococcus aureus

Energy Technology Data Exchange (ETDEWEB)

dos Santos, Sara Roberta

2014-06-01

Staphylococcus aureus is specie of great medical importance because it is often associated with many infections in humans. This bacterium can cause diseases ranging from simple infections to life-threatening infections such as endocarditis, pneumonia, meningitis, toxic shock syndrome, septicemia, osteomyelitis, among others. S. aureus is the most commonly agent found in infections of the skin and soft tissues, bone infections and bone prostheses. The difficulty in early detection of specific foci caused by bacteria has raised the need to search for new techniques for this purpose. Diagnosis by scintigraphy has advantages over other methods because it is able to identify damage tissues without the need of invasive procedures and is able to perform an early diagnosis even before anatomic changes. Thus, nuclear medicine could contribute to an accurate diagnosis of bacterial infections, since specific radiopharmaceuticals were developed. Aptamers are oligonucleotides that have high affinity and specificity for their molecular targets and are emerging as a new class of molecules for radiopharmaceuticals development. Radiolabeled aptamers specific to the infectious agents, could give a significant contribution to the infection diagnosis by scintigraphy. In this study, aptamers selected to S. aureus were labeled with {sup 99m}Tc and used for the bacteria identification in vitro and in vivo. The aptamers labeled with {sup 32}P and incubated in vitro with S. aureus cells showed high affinity for the bacterial cells when compared with the library of oligonucleotides with random sequences used as control. The aptamers labeled with {sup 99m}Tc also showed affinity for S. aureus cells when compared with the library, but unspecific binding was also verified. The {sup 99m}Tc labelled aptamers were stable in 0.9% saline, plasma of Swiss mice and in excess of cysteine. The in vivo biodistribution studies using Swiss mice with intramuscular infection in the right thigh showed that

Production of the antimicrobial peptide UBI 29-41 labelled with 99mTc by an indirect method; Obtencion del peptido antimicrobiano UBI 29-41 marcado con 99mTc empleando un metodo indirecto

Energy Technology Data Exchange (ETDEWEB)

Nevares, Noemi; Crudo, Jose L; Zapata, Miguel; Castiglia, Silvia G. de [Comision Nacional de Energia Atomica, Ezeiza (Argentina). Dept. de Radioquimica

2003-07-01

The infection processes are a major problem in human health causing a high number of human deaths all around the world. Diagnostic imaging in nuclear medicine is an attractive option in the detection of infection processes due to its sensitivity. The antimicrobial peptides are very important in the development of new radiopharmaceuticals, since their antimicrobial activity towards a great variety of microorganisms have been proven. The aim of this work was to obtain the antimicrobial peptide UBI 29-41 labelled with technetium 99 m, by an indirect method via NHS-Hynic and tricine as a coligand, and evaluate its stability and its ability to discriminate between infection and inflammation sites. The radiochemical purity of the labeling procedure was 95.5{+-}1,2 %. The cysteine challenge showed a great stability of the 99mTc UBI-Hynic, and the stability in human serum showed that the 81% of the radioactivity remained bounded to UBI-Hynic at 48 hs of incubation. The bio distribution's studies showed main elimination via kidney of 99mTc UBI-Hynic and the target/non target ratio was 1,81 for infected mice and 1,16 for inflamed mice. (author)

Single-molecule visualization of Saccharomyces cerevisiae leading-strand synthesis reveals dynamic interaction between MTC and the replisome.

Science.gov (United States)

Lewis, Jacob S; Spenkelink, Lisanne M; Schauer, Grant D; Hill, Flynn R; Georgescu, Roxanna E; O'Donnell, Michael E; van Oijen, Antoine M

2017-10-03

The replisome, the multiprotein system responsible for genome duplication, is a highly dynamic complex displaying a large number of different enzyme activities. Recently, the Saccharomyces cerevisiae minimal replication reaction has been successfully reconstituted in vitro. This provided an opportunity to uncover the enzymatic activities of many of the components in a eukaryotic system. Their dynamic behavior and interactions in the context of the replisome, however, remain unclear. We use a tethered-bead assay to provide real-time visualization of leading-strand synthesis by the S. cerevisiae replisome at the single-molecule level. The minimal reconstituted leading-strand replisome requires 24 proteins, forming the CMG helicase, the Pol ε DNA polymerase, the RFC clamp loader, the PCNA sliding clamp, and the RPA single-stranded DNA binding protein. We observe rates and product lengths similar to those obtained from ensemble biochemical experiments. At the single-molecule level, we probe the behavior of two components of the replication progression complex and characterize their interaction with active leading-strand replisomes. The Minichromosome maintenance protein 10 (Mcm10), an important player in CMG activation, increases the number of productive replication events in our assay. Furthermore, we show that the fork protection complex Mrc1-Tof1-Csm3 (MTC) enhances the rate of the leading-strand replisome threefold. The introduction of periods of fast replication by MTC leads to an average rate enhancement of a factor of 2, similar to observations in cellular studies. We observe that the MTC complex acts in a dynamic fashion with the moving replisome, leading to alternating phases of slow and fast replication.

Utility of the tetrophosmine-{sup 99m}Tc in the determination of malignant tumours located in the muscle-skeletal system, preliminary report; Utilidad de la tetrofosmina-{sup 99m}Tc en la determinacion de malignidad de tumores localizados en el sistema musculoesqueletico, reporte preliminar

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Garcia R, J C; Gonzalez, I F; Rico, G; Linares, L M; Delgado C, E; Baena, L [Centro Nacional de Rehabilitacion, Mexico D.F. (Mexico); Adame, G; Gonzalez R, D [MIYMSA, Mexico D.F. (Mexico); Perez C, J P; Valencia, S [Hospital medica Sur, Mexico D.F. (Mexico)

2005-07-01

From its authorization by the FDA, as radiopharmaceutical to be used in studies of myocardial perfusion, multiple articles have appeared in the literature it prescribes that its validate the use of the tetrophosmine-{sup 99m}Tc in the valuation of different tumors, so much in the determination of malignancy, like in the evolution and in the response to the treatment. For that reason the objective of this protocol is to evaluate the utility of the tetrophosmine- {sup 99m}Tc in the determination of malignancy in non treated tumors located in the skeletal muscle system, in a population of 40 patients coming from the service of bony tumors of the National Center of Rehabilitation. For the time being its report the discoveries in 27 studies. (Author)

Comparative study of tricarbonilic complexes of {sup 99m}TC in the diagnosis of fungal infections

Energy Technology Data Exchange (ETDEWEB)

Fernández, Leticia Gabriela; Teran, Mariella Adriana [Facultad de Quimica, Montevideo (Uruguay); Reyes, Ana Laura [Cudim, Montevideo (Uruguay)

2017-07-01

Full text: Introduction: Clinical-epidemiological studies show that the incidence of fungal infections has experienced a substantial increase in the last years. Our working group focused on the radioactive labelling of commercially available antifungal agents and their evaluation as potential specific tracer agents for fungal infections (Curr Radiopharm, 2014, 7( 2), 144-150). Objective: Optimization of various antifungal agents labelling using {sup 99m}Tc tricarbonyl complexes and their subsequent evaluation in vitro and in vivo as radiotracers in the detection, through scintigraphic images, of fungal infections. Methodology: Complexes were obtained by substitution of the precursor triaquotricarboniltechnetium (I) with the antifungals: Caspofungin, amphotericin b, Voriconazole and Fluconazole[2]. The physicochemical evaluation of the complexes was performed by the analysis of the stability in milieu, stability in plasma, lipophilicity, plasma protein binding and binding to yeasts. The biological evaluation of the complexes was carried out according to the protocol 070510 approved by the Commission of Animal Experimentation (University of the Republic, Uruguay). The model used consisted of CD1 mice (n=4 per group), females of 8-10 weeks with a weight of 22 ± 2 g. The groups studied were: G0=healthy animals, G1=sterile inflammation, G2=infection by C.albicans and G3=infection by A.niger. The lesions were induced by inoculation of 100μL of the agents in the left hind thigh. Once the lesions were developed, the complexes were administered iv (37MBq,1mCi in 0.1mL) and biodistribution studies were performed at various post-injection times. In addition, images were acquired in a preclinical image system for animals for 60 min, 40 mm ROR, 5-pinhole collimator, 80 x 80 pixel array. Results: All the complexes were obtained with a radiochemical purity higher to 90,0% and were stable more than 4 hours post substitution. Plasma stability, Log P, Protein binding and C

Submandibular gland function and parotid gland function in Bell's palsy, 3

International Nuclear Information System (INIS)

Ino, Chiyonori; Yamashita, Toshio; Kato, Mako; Kumazawa, Tadami

1986-01-01

With the use of sup(99m)Tc, we attempted to measure simultaneously submandibular gland function and parotid gland function, which is thought not to be controlled by the facial nerve, in patients with unilateral Bell's palsy. For comparison, the lachrymal gland function of some patients was measured by the thread method. We found that facial palsy sometimes affects parotid gland function as well as submandibular gland function. In 60 % of the patients the function of the two glands tended to be affected in the same way. Lachrymal gland function tended to be affected in a similar way to parotid gland function. We conclude that the chorda tympani and the greater petrosal nerve may influence parotid gland function. (author)

Labeling of human immune gamma globulin with sup(99m)Tc

International Nuclear Information System (INIS)

Wong, D.W.; Huang, J.T.

1977-01-01

Human immune serum gamma globulin and rabbit anti-Stap. aureus antibody have been successfully labeled with sup(99m)Tc at pH 7.4 with an average binding efficiency of 86 and 82%, respectively. The labeled proteins behave similarly to unlabeled gamma-globulin fraction in the normal human serum as demonstrated by protein electrophoresis. The biological half-time of sup(99m)Tc-gamma-globulin in dog has been determined to be 54 min for the fast component and 14.7 hr for a slower component. Immunological assays demonstrate no significant change in antibody activity after labeling process. (author)

Synthesis, characterization and biological evaluation of a novel ''3+1'' mixed ligand {sup 99m}Tc complex having an aliphatic thiol as coligand

Energy Technology Data Exchange (ETDEWEB)

Rey, A. E-mail: arey@bilbo.edu.uy; Papadopoulos, M.; Leon, E.; Mallo, L.; Pirmettis, Y.; Manta, E.; Raptopoulou, C.; Chiotellis, E.; Leon, A

2001-03-01

A novel ''3+1'' mixed ligand {sup 99m}Tc complex with N,N-bis(2-mercaptoethyl)-N'N'-diethyl-ethilenediamine as ligand and 1-octanethiol as coligand was prepared and evaluated as potential brain radiopharmaceutical. Preparation at tracer level was accomplished by substitution, using {sup 99m}Tc-glucoheptonate as precursor and a coligand/ligand ratio of 5. Under these conditions the labeling yield was over 80% and a major product with radiochemical purity >80% was isolated by HPLC methods and used for biological evaluation. Chemical characterization at carrier level was developed using the corresponding rhenium and {sup 99g}Tc complexes. Results were consistent with the expected ''3+1'' structure and X-ray diffraction study demonstrated that the complex adopted a distorted trigonal bipyramidal geometry. All sulphur atoms underwent ionization leading to the formation of a neutral compound. Biodistribution in mice demonstrated early brain uptake, fast blood clearance and excretion through hepatobiliary system. Although brain/blood ratio increased significantly with time, this novel {sup 99m}Tc complex did not exhibit ideal properties as brain perfusion radiopharmaceutical since brain uptake was too low.

Survey of /sup 99m/Tc contamination of laboratory personnel: hand decontamination

International Nuclear Information System (INIS)

Nishiyama, H.; Van Tuinen, R.J.; Lukes, S.J.; Feller, P.A.

1980-01-01

Decontamination after exposure to various /sup 99m/Tc radiopharmaceuticals was tested with serial hand washings both with and without soap. All radiopharmaceuticals were removed more effectively with soap and the degree of decontamination related closely to the number of washings. The affinity of the radiopharmaceuticals for the skin varied, depending upon the labeled material, and only macroaggregated albumin was effectively removed to less than 1% of its original activity with soap. Activity transfer to the opposite hand could be substantial with macroaggregated albumin and sulfur colloid if soap is not used

Dosimetric contribution of organs of biokinetics of {sup 99m}Tc and {sup 123}I to estimate radiation doses in thyroids of children of 1 and 5 years; Contribucion dosimetrica de organos de la biocinetica del {sup 99m}Tc y {sup 123}I para estimar dosis en tiroides de ninos de 1 y 5 anos

Energy Technology Data Exchange (ETDEWEB)

Vasquez, M.V.; Castillo, C.E.; Abanto, D.M.; Rocha, D.; Garcia, W.H.; Marin, K., E-mail: marvva@hotmail.com [Universidad Nacional de Trujillo (UNT), Trujillo (Peru); Quispe, R. [Centro de Ciencias Aplicadas y Desarrollo Tecnologico, UNAM, Mexico (Mexico)

2015-07-01

The absorbed doses by thyroids during uptake studies through biokinetics of radiopharmaceuticals containing {sup 123}I (iodine) or {sup 99m}Tc (pertechnetate) are estimated. Using the MIRD scheme and the representation of Cristy-Eckerman for thyroids in children of 1 and 5 years, the objective of the study was to determine whether the dosimetric biokinetic contributions of the organs of {sup 123}I (iodide) and {sup 99m}Tc (pertechnetate) biokinetic are significant in the estimated of the absorbed dose for thyroid uptake studies.

Use of [sup 99m]Tc mercaptoacetyltriglycine (MAG3) for detection of renal lesions after ESWL. A prospective study with 117 patients. [sup 99m]Technetium-Mercaptoacetyltriglycin (MAG3) zum Nachweis von Nierenveraenderungen nach extrakorporealer Stosswellenlithotripsie. Eine prospektive Untersuchung bei 117 Patienten

Energy Technology Data Exchange (ETDEWEB)

Schaub, T. (Klinik mit Poliklinik fuer Radiologie, Universitaetsklinik Mainz (Germany)); Witsch, U.; El-Damanhoury, H. (Klinik mit Poliklinik fuer Urologie, Universitaetsklinik Mainz (Germany)); Naegele-Woehrle, B.; Hahn, K. (Klinik mit Poliklinik fuer Nuklearmedizin, Universitaetsklinik Mainz (Germany))

1992-10-01

Extracorporeal shock wave lithotripsy (ESWL) has become the treatment of choice for urinary calculi. 117 patients were studied prospectively with [sup 99m]Tc Mercaptoacetyltriglycine (MAG3) before and after ESWL. 79 (66%) of the 119 kidneys treated had abnormal findings. Of these 63/119 (53%) had abnormal scans. 41 (65%) had focal lesions with a delayed intrarenal transport. The remaining 22 had a diffuse delay of intrarenal transport. A loss of relative renal function of 3% and more compared to the pretreatment values was observed in 50/119 (42%) patients. [sup 99m]Tc MAG3 should be done routinely together with radiologic tests (CT or MRI) before and after ESWL to select the patients at risk for post ESWL hypertension. (orig.).

Effect of acidity and chemical composition of sup(99m)Tc-radiopharmaceuticals on sup(99m)Tc accumulation in necrotic tissue of rat myocardium

Energy Technology Data Exchange (ETDEWEB)

Vilcek, S; Machan, V; Kalincak, M [Ustav Radioekologie a Vyuzitia Jadrovej Techniky, Kosice (Czechoslovakia); Nicak, A [Univerzita P.J. Safarika, Kosice (Czechoslovakia). Lekarska Fakulta

1981-04-30

Experiments showed that the cumulation of technetium-99m following the administration of /sup 99m/Tc-Sn-pyrophosphate and s/sup 99m/Tc-Sn-oxytetracycline in the necrotic tissue of rat myocardium damaged by cauterization depended on the end pH value. The maximum /sup 99m/Tc cumulation in the myocardial lesion was noted when the end pH value ranged in 5.5 to 6.0. It appeared that pyrophosphate concentration decrease below the critical limit not only affected the cumulation of /sup 99m/Tc in the particular organs but also in the necrotic tissue of the myocardium.

Effect of acidity and chemical composition of sup(99m)Tc-radiopharmaceuticals on sup(99m)Tc accumulation in necrotic tissue of rat myocardium

International Nuclear Information System (INIS)

Vilcek, S.; Machan, V.; Kalincak, M.; Nicak, A.

1981-01-01

Experiments showed that the cumulation of technetium-99m following the administration of sup(99m)Tc-Sn-pyrophosphate and sup(99m)Tc-Sn-oxytetracycline in the necrotic tissue of rat myocardium damaged by cauterization depended on the end pH value. The maximum sup(99m)Tc cumulation in the myocardial lesion was noted when the end pH value ranged in 5.5 to 6.0. It appeared that pyrophosphate concentration decrease below the critical limit not only affected the cumulation of sup(99m)Tc in the particular organs but also in the necrotic tissue of the myocardium. (author)

Investigation of circulating temperature fluctuations of the primary coolant in order to develop an enhanced MTC estimator for VVER-440 reactors

Energy Technology Data Exchange (ETDEWEB)

Kiss, Sandor; Lipcsei, Sandor [Hungarian Academy of Sciences, Budapest (Hungary). Centre for Energy Research - MTA

2017-09-15

Our aim was to develop a method based on noise diagnostics for the estimation of the moderator temperature coefficient of reactivity (MTC) for the Paks VVER-440 units in normal operation. The method requires determining core average neutron flux and temperature fluctuations. The circulation period of the primary coolant, transfer properties of the steam generators, as well as the source and the propagation of the temperature perturbations and the proportions of the perturbation components were investigated in order to estimate the feedback caused by the circulation of the primary coolant. Finally, after developing the new MTC estimator, determining its frequency range and optimal parameters, trends were produced based on an overall evaluation of measurements made with standard instrumentation during a one-year-long period at Paks NPP.

Technology of the sup(99m)Tc generator, Elumatic III made by Commissariat a l'Energie Atomique, France

International Nuclear Information System (INIS)

Le Bris, H.; Pasqualini, R.; Reboul, J.

1982-01-01

The article describes the choices leading to the development of an ''integrated'' 99 Mo-sup(99m)Tc generator meeting the following requirements: (a) total activity eluted in a volume of 5 ml; (b) adequate radioprotection both for the user and the manufacturer; (c) injectable eluate. (author)

Phenolic aminocarboxylate chelates of sup(99m)Tc as hepatobiliary agents

Energy Technology Data Exchange (ETDEWEB)

Hunt, F.C.; Maddalena, D.J.; Wilson, J.G.; Bautovich, G.J.

1986-01-01

A series of alkyl- and halogen-substituted derivatives of ethylenediamine di(omicron-hydroxyphenylacetic acid) (EDDHA) and N,N'-bis(2-hydroxybenzyl) ethylenediamine N,N'-diacetic acid (HBED) were complexed with sup(99m)Tc and their biodistribution was determined in rats. All complexes displayed substantial hepatobiliary excretion; of each series, sup(99m)Tc-Br-EDDHA and sup(99m)Tc-di-Cl-HBED had the maximum amount in the gastrointestinal tract. Scintigraphic studies of sup(99m)Tc-Cl-EDDHA in dogs revealed prompt imaging of the liver followed by imaging of the gall bladder as the complex was excreted into the bile.

Phenolic aminocarboxylate chelates of sup(99m)Tc as hepatobiliary agents

International Nuclear Information System (INIS)

Hunt, F.C.; Maddalena, D.J.; Wilson, J.G.; Bautovich, G.J.

1986-01-01

A series of alkyl- and halogen-substituted derivatives of ethylenediamine di[omicron-hydroxyphenylacetic acid] (EDDHA) and N,N'-bis[2-hydroxybenzyl] ethylenediamine N,N'-diacetic acid (HBED) were complexed with sup(99m)Tc and their biodistribution was determined in rats. All complexes displayed substantial hepatobiliary excretion; of each series, sup(99m)Tc-Br-EDDHA and sup(99m)Tc-di-Cl-HBED had the maximum amount in the gastrointestinal tract. Scintigraphic studies of sup(99m)Tc-Cl-EDDHA in dogs revealed prompt imaging of the liver followed by imaging of the gall bladder as the complex was excreted into the bile. (author)

Preparation and characterization of iron(III) {sup 99}Mo-molybdate(VI) gels for the assessment of {sup 99m}Tc elution performance

Energy Technology Data Exchange (ETDEWEB)

Amin, Mahmoud; Fasih, Tharwat W.; El-Absy, Mohamed A. [Egyptian Atomic Energy Authority, Cairo (Egypt)

2018-04-01

New iron(III) {sup 99}Mo-molybdate(VI) gels (Fe{sup 99}Mo) of high Mo content were prepared by the precipitation/filtration method. {sup 99}Mo-MoO{sub 3} dissolved in NaOH was added to aqueous solutions of Fe(NO{sub 3}){sub 3} at Mo/Fe mole fractions ∝2.21 and 1.99 with continuous stirring at ambient room temperature. Two different Fe{sup 99}Mo were precipitated from the mixed solutions adjusted at pH 2 and 4.7. The amount of water of hydration increased with the increasing the gel settling time and pH of the mixed solution. The matrices were characterized by radiometric, XRD, SEM, XRF, FT-IR, TGA, and DTA measurements. Small chromatographic columns of 2.0 g Fe{sup 99}Mo containing ≥800 mg Mo tagged with 740 MBq {sup 99}Mo were eluted with 5 mL saline solution. Highly reproducible {sup 99m}Tc elution indices suitable for preparation of {sup 99}Mo/{sup 99m}Tc generators were achieved from generator supported with 0.5 g Al{sub 2}O{sub 3} filter. Elution performance of {sup 99m}Tc radionuclide was highly dependent on the gel structural properties.

An embedded system based computer controlled process automation for recovery and purification of 99mTc from (n,γ)99Mo

International Nuclear Information System (INIS)

De, Anirban; Pal, S.S.; Bhaskar, P.; Kumari, S.; Khare, V.K.; Duttaroy, A.; Garai, M.; Thakur, S.K.; Saha, S.; Chattopadhyay, Sankha; Barua, Luna; Das, Sujata Saha; Kumar, U.; Das, M.K.

2012-01-01

99 Mo produced 99 mTc (t 1/2 = 6 hr, 140 KeV γ-ray) is the most useful radioisotope for nuclear diagnostics. High specific activity 99 Mo is supplied globally mainly by five old reactors whose routine or unscheduled maintenance shutdown causes supply irregularities that adversely affects patient management in nuclear medicine centres. 99m Tc may also be produced via 98 Mo(n,γ) in a natural MoO 3 target in reactor or by 100 Mo(n,2n) 99 Mo or 100 Mo(p,2n) 99 mTc reaction in cyclotron. To meet the crisis proposals are there to produce 99 Mo by 100 Mo(n,2n) 99 Mo or 99m Tc directly by 100 Mo(p,2n) 99m Tc in a cyclotron. Of the several separation methods of 99 mTc from molybdenum, the most common are adsorption column chromatography, sublimation and liquid-liquid solvent extraction. The conventional methods besides being cumbersome are often hazardous, polluting, require skilled manpower and facilities like fume hood and so are not always practically feasible for hospitals. To address these, VECC and BRIT, Kolkata have collaborated to develop an embedded system based automated 99 Mo/ 99m Tc generator from low specific activity 99 Mo using solvent extraction technique, supervised by a PC based GUI. (author)

{sup 99m}Tc sestamibi cardiac tomography and dobutamine echocardiography in the identification of reversible left ventricular dysfunction in patients with acute myocardial infarction; Tomografia cardiaca con {sup 99m}Tc sestamibi ed ecocardiografia con dobutamina nell'identificazione della disfunzione ventricolare sinistra reversibile nei pazienti con infarto acuto del miocardio

Energy Technology Data Exchange (ETDEWEB)

Gisonni, P.; Cuocolo, A.; Spinelli, L.; Acampa, W.; Florimonte, L.; Nicolai, E.; Petretta, M.; Sodano, A. [Naples Univ. Federico 2. (Italy). Centro per la Medicina Nucleare del Consiglio Nazionale delle Ricerche. Dipt. di Scienze Biomorfologiche e Funzionali

1999-04-01

The authors investigated the role of technetium-99m ({sup 99m}Tc) sestamibi cardiac imaging and dobutamine echocardiography in detecting myocardial viability early after acute myocardial infarction. [Italian] La presenza di tessuto miocardico ibernato o stordito contribuisce alla genesi della disfunzione ventricolare sinistra nei pazienti con infarto del miocardio. L'identificazione del miocardio malfunzionante ma ancora vitale ha particolare rilevanza nel predire il recupero della funzione ventricolare in seguito a interventi di rivascolarizzazione coronarica. In questo studio e' stato valutato il ruolo della scintigrafia con tecnezio-99m ({sup 99m}Tc) sestamibi e dell'ecocardiografia con dobutamina nell'identificazione del miocardio vitale dopo infarto acuto del miocardio.

Study of different absorbent materials for the preparation of generator systems of {sup 99}Mo - {sup 99m}Tc and {sup 188}W-{sup 188}Re

Energy Technology Data Exchange (ETDEWEB)

Lopes, Paula Regina Corain; Osso Junior, Joao Alberto, E-mail: paulinhacorain@usp.b, E-mail: jaosso@ipen.b [Instituto de Pesquisas Energeticas e Nucleares (IPEN/CNEN-SP), Sao Paulo, SP (Brazil)

2009-07-01

Amongst some currently radioisotopes, {sup 99m}Tc and {sup 188}Re present adequate decay properties for use in Nuclear Medicine. In the current times the most diagnosis examinations are performed with {sup 99m}Tc and {sup 188}Re is one radioisotope of potential use in therapy techniques. The objective of this work consists of determining the capacity of some adsorbent materials for retention of molybdenum and tungsten, aiming the optimization of generator systems of {sup 99}Mo-{sup 99m}Tc and {sup 188}W-{sup 188}Re with suitable characteristics for application in Nuclear Medicine. Known amounts, in mass, of molybdenum and tungsten were percolated through different chromatographic columns containing different commercial adsorbent materials such as: PZC (poly-zirconium compound), acid alumina and calcinated alumina used in the routine preparation of {sup 99}Mo-{sup 99m}Tc generators at IPEN. The tungsten ({sup 188}W), as well the PZC used in this project, supplied by Russia and Japan, respectively, through the International Atomic Energy Agency (IAEA) and used without any previous preparation. Also trace amounts of {sup 99}Mo and {sup 188}W were added to the initial solutions and the generators were assembled. The {sup 99}Mo-{sup 99m}Tc generators were then eluted with known volumes of 0.9% NaCl solution every 24 hours whereas the {sup 188}W-{sup 188}Re generators were eluted every 48 hours. The eluted samples were analyzed by Gamma Spectroscopy and later submitted to quality control evaluation. The results showed that the PZC presents superior retention capacity for Mo of 97.50mg Mo/gPZC, higher than in acid and calcinated alumina, however the elution efficiency at lower pHs is not so high. With regards to the experiments carried out with {sup 188}W and alumina, it was verified that the elution efficiency of {sup 188}Re was not reproducible and the retention capacity of W was 90.23mgW/gAl{sub 2}O{sub 3} at pH 7. (author)

Comparison of /sup 99m/Tc diethyl-iminodiacetic acid and 131I rose bengal for hepatobiliary studies in liver-transplant patients: concise communication

International Nuclear Information System (INIS)

Klingensmith, W.C. III; Fritzberg, A.R.; Koep, L.J.

1979-01-01

Previous animal studies indicate that technetium-99m N,α-(2,6-diethylacetanilide)-iminodiacetic acid (/sup 99m/Tc diethyl-IDA) is superior to 131 I rose bengal ( 131 I RB) in most, but not all, physiologic parameters. Technetium-99m diethyl-IDA has a faster blood clearance, greater hepatic clearance, and a shorter hepatocyte transit time, but 131 I RB exhibits less renal clearance. We evaluated the relative merits of /sup 99m/Tc-diethyl-IDA and 131 I RB in paired studies in ten liver-transplant patients. Technetium-99m diethyl-IDA images were superior to 131 I RB images in demonstrating: (1) the liver parenchyma, (2) intrahepatic ducts, (3) small-bowel activity early after injection, and (4) in a smaller number of comparisons, colonic activity at 24 hr after injection. In addition, the percentage of dose excreted in the urine in 3 h for both radiopharmaceuticals was measured in 19 patients (total serum bilirubin range: 0.5 to 22.4 mg/dl). The percentage of dose of/sup 99m/Tc diethyl-IDA excreted in the urine averaged 7.5 in patients with normal total bilirubin levels and increased significantly with increasing total bilirubin levels. In the case of 131 I RB, normal patients averaged 4.9% of the injected dose in the urine and there was no increase with increasing total bilirubin levels. It is concluded that (1) /sup 99m/TC diethyl-IDA is superior to 131 I RB for imaging the hepatobiliary system, and (2) renal excretion of 131 I RB, unlike that of /sup 99m/Tc diethyl-IDA, is relatively unaffected by the total serum bilirubin level during the first 3 h after injection

The place occupied by early measurement (20th minute) of the thyroid uptake of sup(99m)Tc pertechnetate in thyroid pathology

International Nuclear Information System (INIS)

Guilloteaux, Gerard.

1977-01-01

The place occupied by early measurement (20th minute) of the thyroid uptake of sup(99m)Tc pertechnetate is situated for different types of thyroid condition (hypo-, normo- and hyperthyroidism). The use of technetium is simple in practice because only the cervical and crural radioactivity measurements are required. Like all simplified methods it involves risks of errors but lends itself to systematic routine use. The practical advantages of this isotope, which in view of its short half-life appears with iodine 123 as the nearly ideal tracer for thyroid exploration at present are outlined. The thyroid gland can be studied both functionally and scintigraphically at the cost of minimum irradiation, which is a great advantage. The fact that a number of data may be obtained in less than an hour (including scintigraphy) is a particularly valuable asset. However the method has its limits. For example a diagnosis of hyper or hypothyroidism based on the technetium uptake at the 20th minute alone is out of the question. A zero uptake may be observed in the presence of Basedow's disease or conversely a high uptake in hypo- or euthyroid cases. Discrimination is satisfactory between hyper and euthyroid but not between eu- and hypothyroid subjects. Technological progress however promises a routine use of 123 I and 99mTc together, the two isotopes serving to explore two different phases of the thyroid metabolism [fr

A new inorganic adsorbent of (n, {gamma}){sup 99}Mo for the practical {sup 99m}Tc generator

Energy Technology Data Exchange (ETDEWEB)

Hasegawa, Y; Nishino, M [Kaken Co., Asahi, Ibaraki (Japan). Functional Materials Inst.; Ishikawa, K; Tatenuma, K; Kurosawa, K; Tanase, M; Yamabayashi, H

1998-10-01

Technetium-99m is used most widely in diagnostic nuclear medicine. By the milking procedure, it is normally eluted as the daughter nuclide from {sup 99}Mo adsorbed in an alumina column as a generator. Molybdenum-99 with high specific activity has been produced in large quantities from the fission of irradiated {sup 235}U. However, the production process involves the troublesome handling process of various fission products in the high radiation field and generates highly radioactive and poisonous wastes. To avoid these drawbacks, some gel generators have been proposed. They are of zirconium molybdate, zirconium molybdophosphate or titanium molybdate gel, which are able to be applied to {sup 99}Mo obtained easily by (n, {gamma}) reaction of natural Mo. However, it has become apparent that the gel has been prepared only under certain strict conditions such as concentrations and reaction temperature, and eventually the elution rate of {sup 99m}Tc was unstable because of any influences of the gel preparation conditions. We have developed and reported a new inorganic adsorbent (Polyinorganic Zirconium Compound: PZC) of {sup 99}Mo with a low specific activity obtained by (n, {gamma}) reaction to overcome the problems of gel generators above mentioned. PZC was prepared from ZrCl{sub 4} and isopropyl alcohol. The adsorbed amount of {sup 99}Mo (Mo) to PZC was about 200 mg/g-PZC, and the yield of {sup 99m}Tc was about 80%. And the breakthrough of {sup 99}Mo was less than 0.5%. In this paper, the properties of the improved PZC, performance of generators with {sup 99}Mo loaded from 0.5 to 470 MBq, and a method to reduce the breakthrough of {sup 99}Mo are described. (author)

Labelling and optimization of PHOTOFRIN {sup registered} with {sup 99m}Tc

Energy Technology Data Exchange (ETDEWEB)

Fakhar-e-Alam, M. [Pakistan Institute of Engineering and Applied Sciences, Islamabad (Pakistan); Roohi, S.; Amir, N.; Zahoor, R. [Pakistan Institute of Nuclear Science and Technology, Islamabad (Pakistan). Isotope Production Div.; Atif, M.; Firdous, S. [National Institute of Laser and Optronics, Islamabad (Pakistan). Biophotonics Lab.

2010-07-01

PHOTOFRIN {sup registered} was labelled with {sup 99m}Tc using SnCl{sub 2}.2H{sub 2}O as reducing agent. Instant thin layer chromatography (ITLC-SG) in 0.05 M NaOH was used for evaluation of radiochemical purity. Labelling efficiency was dependent on various factors that include the ligand/reductant ratio, pH and time of incubation. Therefore, optimum conditions of labelling were also determined. The stability of {sup 99m}Tc-PHOTOFRIN {sup registered} in serum was checked by using fresh human serum. Tissue distribution of {sup 99m}Tc-PHOTOFRIN {sup registered} was evaluated in Sprague Dawley rats. PHOTOFRIN {sup registered} was labelled with an efficiency of > 95% under optimum conditions, which were PHOTOFRIN {sup registered}: 200 {mu}g, pH: 3-4, SnCl{sub 2}.2H{sub 2}O: 15 {mu}g and 30 min incubation at room temperature. The {sup 99m}Tc-labelled PHOTOFRIN {sup registered} remained stable in human serum for 24 h. Biodistribution study in rats revealed maximum concentration of the labelled compound in liver, lungs and spleen at 0.5 h, and significant activity was also seen in the bladder and urine, indicating the mode of urinary excretion of PHOTOFRIN {sup registered}. (orig.)

Spectrophotometric determination of Sn+2 in lyophilized kit for labeling with 99mTc

International Nuclear Information System (INIS)

Araujo, Elaine Bortoleti; Sampel, Carolina Judith; Melo, Ivani Bortoleti; Okamoto, Miriam R.Y; Silva, Constancia P.G

2004-01-01

The preparation of 99 mTc labeled radiopharmaceuticals depends on the reduction of the technetium pertechnetate, commonly by stannous chloride (SnCl 2 ). The determination of the Sn +2 contents in the lyophilized preparations represents an important quality control procedure that may be applied to the process and to the final product. The objective os this work is the optimization of an spectrophotometric assay to the determination os Sn +2 contents in a citrate-stannous lyophilized kit for 99 mTc labeling. The spectrophotometric methodology employed is based in the colour development when Sn +2 reacts with sodium molybdate in the presence of potasium thiocyanate in chloridric medium. The colourfull reaction studied showed high stability after 60 minutes of the mixtures preparation. The sequence of reagents introduction in the reaction mixture was determinant to the assay. The molibdenium-stannous-tiocianate sequence produces calibration curves with good correlations (R2 ≥ 0.99). The concentrations of the molibdenium solution was also studied, in order to determine a ideal concentration for the Sn +2 range. The spectrophotometric method studied was usefull to the determination of Sn +2 content in different batches of citrate-stannous preparations. The method was fast and easy and can be applied to different stages of the production process, in order to guarantee the content of Sn +2 in the preparations (Au)

Diagnostic value of (99m)Tc-3PRGD2 scintimammography for differentiation of malignant from benign breast lesions: Comparison of visual and semi-quantitative analysis.

Science.gov (United States)

Chen, Qianqian; Xie, Qian; Zhao, Min; Chen, Bin; Gao, Shi; Zhang, Haishan; Xing, Hua; Ma, Qingjie

2015-01-01

To compare the diagnostic value of visual and semi-quantitative analysis of technetium-99m-poly-ethylene glycol, 4-arginine-glycine-aspartic acid ((99m)Tc-3PRGD2) scintimammography (SMG) for better differentiation of benign from malignant breast masses, and also investigate the incremental role of semi-quantitative index of SMG. A total of 72 patients with breast lesions were included in the study. Technetium-99m-3PRGD2 SMG was performed with single photon emission computed tomography (SPET) at 60 min after intravenous injection of 749 ± 86MBq of the radiotracer. Images were evaluated by visual interpretation and semi-quantitative indices of tumor to non-tumor (T/N) ratios, which were compared with pathology results. Receiver operating characteristics (ROC) curve analyses were performed to determine the optimal visual grade, to calculate cut-off values of semi-quantitative indices, and to compare visual and semi-quantitative diagnostic values. Among the 72 patients, 89 lesions were confirmed by histopathology after fine needle aspiration biopsy or surgery, 48 malignant and 41 benign lesions. The mean T/N ratio of (99m)Tc-3PRGD2 SMG in malignant lesions was significantly higher than that in benign lesions (Pvalue for the detection of primary breast cancer, the sensitivity, specificity and accuracy were 81.3%, 70.7%, and 76.4%, respectively. When a T/N ratio of 2.01 was used as cut-off value, the sensitivity, specificity and accuracy were 79.2%, 75.6%, and 77.5%, respectively. According to ROC analysis, the area under the curve for semi-quantitative analysis was higher than that for visual analysis, but the statistical difference was not significant (P=0.372). Compared with visual analysis or semi-quantitative analysis alone, the sensitivity, specificity and accuracy of visual analysis combined with semi-quantitative analysis in diagnosing primary breast cancer were higher, being: 87.5%, 82.9%, and 85.4%, respectively. The area under the curve was 0.891. Results of

99m-Tc tetrofosmin scintigraphy vs mammography in breast cancer detection

International Nuclear Information System (INIS)

Jaukovic, L.J.; Spaic, R.; Markovic, S.; Stankovic, N.; Dimitrijevic, S.; Strbac, M.

2002-01-01

99m-Tc tetrofosmin is a widely used radiotracer for breast cancer imaging. Routine mammography ,as a method for screening breast cancer patients, might be insufficient for diagnosis, especially in patients with dense breast. Aim: The aim of this study was to compare the results of mammography (MM) and scintimammography with 99m- Tc tetrofosmin (SMM) in detection of primary breast cancer. Method: Thirty patients with breast disease were included in study. All of them had clinical investigation, MM, SMM and surgical biopsy for final histological diagnosis. An amount of 600 MBq 99m- Tc tetrofosmin was injected intravenously in the arm opposite to the side of breast lesion. Ten minutes after injection planar breast 7-minutes scans were performed in supine (anterior) and prone (left and right lateral) position. Results: Out of 30 lesion breast cancer was histologically confirmed in 20 (15 ductal invasive, two lobular, one colloid, one papillar carcinoma and one case of cyst sarcoma phylodes- malignant type.) For MM sensitivity of 80%, specificity of 60% and accuracy of 76 % were obtained. At SMM 19/ 20 malignant lesions were detected. Only one false negative result was obtained in 1.0 cm lobular infiltrative cancer, although the smallest detectable lesion measured 0.6 cm. At pathohistology ten lesions presented benign. Four false positive results (two fibroadenomas, one lipogranuloma and one case of fibrocystic disease) were observed, six true negative results in four cases with fibrocystic disease and two fibroadenomas. The overall sensitivity of scintimammography was 95%, specificity 60% and accuracy 83%. Conclusion: We concluded that sensitivity of 99m-Tc tetrofosmin scintimammography in detection of breast cancer is superior to that of mammography. Our results suggest that 99m -Tc tetrofosmin is a suitable tumor seeking agent for breast cancer imaging

The study of interaction of modified fatty acid with {sup 99m}Tc in alcoholic media

Energy Technology Data Exchange (ETDEWEB)

Skuridin, V. S.; Stasyuk, E. S.; Varlamova, N. V.; Nesterov, E. A.; Sadkin, V. L.; Rogov, A. S., E-mail: rogov@tpu.ru; Ilina, E. A.; Larionova, L. A.; Villa, N. E. [Institute of Physics and Technology, Tomsk Polytechnic University, Tomsk, 634050 (Russian Federation); Sinilkin, I. G.; Zelchan, R. V. [Institute of Physics and Technology, Tomsk Polytechnic University, Tomsk, 634050 (Russian Federation); Tomsk Cancer Research Institute, Tomsk, 634050 (Russian Federation); Sazonova, S. I. [Institute of Physics and Technology, Tomsk Polytechnic University, Tomsk, 634050 (Russian Federation); Research Institute of Cardiology, Tomsk, 634012 (Russian Federation)

2016-08-02

The paper presents the results of laboratory research aimed at the development of methods of synthesis of new radiodiagnostic agents based on modified fatty acid labelled with technetium-99m intended for scintigraphic evaluation of myocardial metabolism. In particular, the interaction of substance with {sup 99m}Tc in alcoholic media and the use of ethanol as solvent in the synthesis of the radiopharmaceutical were studied.

Axitinib treatment in advanced RAI-resistant differentiated thyroid cancer (DTC) and refractory medullary thyroid cancer (MTC).

Science.gov (United States)

Capdevila, Jaume; Trigo, José Manuel; Aller, Javier; Manzano, José Luís; Adrián, Silvia García; Llopis, Carles Zafón; Reig, Òscar; Bohn, Uriel; Cajal, Teresa Ramón Y; Duran-Poveda, Manuel; Astorga, Beatriz González; López-Alfonso, Ana; Martínez, Javier Medina; Porras, Ignacio; Reina, Juan Jose; Palacios, Nuria; Grande, Enrique; Cillán, Elena; Matos, Ignacio; Grau, Juan Jose

2017-10-01

Axitinib, an antiangiogenic multikinase inhibitor (MKI), was evaluated in the compassionate use programme (CUP) in Spain (October 2012-November 2014). 47 patients with advanced radioactive iodine (RAI)-refractory differentiated thyroid cancer (DTC, n  = 34) or medullary thyroid cancer (MTC, n  = 13) with documented disease progression were treated with axitinib 5 mg b.i.d. The primary efficacy endpoint was objective response rate (ORR) by Response Evaluation Criteria In Solid Tumors (RECIST) v1.1. Progression-free survival (PFS) and adverse events (AEs) were secondary objectives. Regulatory authorities validated the CUP, and all patients signed informed consent form. Axitinib was administered as first-line therapy in 17 patients (36.2%), as second-line in 18 patients (38.3%) and as third/fourth-line in 12 patients (25.5%). With a median follow-up of 11.5 months (0-24.3), ORR was 27.7% (DTC: 29.4% and MTC: 23.1%) and median PFS was 8.1 months (95% CI: 4.1-12.2) (DTC: 7.4 months (95% CI: 3.1-11.8) and MTC: 9.4 months (95% CI: 4.8-13.9)). Better outcomes were reported with first-line axitinib, with an ORR of 53% and a median PFS of 13.6 months compared with 16.7% and 10.6 months as second-line treatment. Twelve (25.5%) patients required dose reduction to 3 mg b.i.d. All-grade AEs included asthenia (53.2%), diarrhoea (36.2%), hypertension (31.9%) and mucositis (29.8%); grade 3/4 AEs included anorexia (6.4%), diarrhoea (4.3%) and cardiac toxicity (4.3%). Axitinib had a tolerable safety profile and clinically meaningful activity in refractory and progressive thyroid cancer regardless of histology as first-line therapy. To our knowledge, this is the first time that cross-resistance between MKIs is suggested in thyroid cancer, highlighting the importance of prospective sequential clinical studies. © 2017 European Society of Endocrinology.

Reagent' sets for the concentration of sup(99m)Tc and sup(113m)In

International Nuclear Information System (INIS)

Bianco de Salas, G.N.; Arciprete, J.; Mitta, A.E.A.

1976-10-01

A simple technique for the concentration of the eluates from 99 Mo/sup(99m)Tc and 113 Sn/sup(113m)In generators is described. The reagents' sets provided by the C.N.E.A. for the labelling of different radiopharmaceuticals can be used by only reducing their volumes proportionally. Both concentration techniques for Tc-99m and In-113m will be supplied to users as reagents' sets. (author) [es

Fatores de correção volumétrica na medição de atividade de 99mTc e 123I em calibradores de radionuclídeos

Directory of Open Access Journals (Sweden)

Amanda Ribeiro Correia

2012-04-01

Full Text Available OBJETIVO: Determinar os fatores de correção para a variação volumétrica dos radiofármacos contidos em recipientes de diferentes geometrias. Comparar a influência desses fatores na determinação da atividade de 99mTc e 123I utilizando dois tipos de calibradores: um com câmara de ionização e outro com detector Geiger-Müller (G-M. Avaliar o desempenho de calibradores de alguns serviços de medicina nuclear em medição de atividade de 99mTc e 123I. MATERIAIS E MÉTODOS: Foram utilizados oito calibradores, frascos de vidro 10R, seringas de plástico de 3 e 5 mL e soluções de 99mTc e 123I. Os fatores de correção foram determinados a partir das medições práticas da variação da leitura do calibrador com a variação do volume da solução no recipiente. O desempenho foi avaliado em relação ao critério de aceitação de ±10% de exatidão exigida pela norma brasileira. RESULTADOS: A variação da resposta do calibrador com a variação do volume do frasco foi bem maior no calibrador que utiliza G-M. Ela também foi maior para 123I do que para 99mTc. CONCLUSÃO: Os resultados confirmam que a resposta dos calibradores depende do volume contido nos recipientes. Essa dependência é mais crítica para os calibradores equipados com detector G-M e para 123I quando comparado com 99mTc.

Preclinical evaluation of (99m)Tc labeled chondroitin sulfate for monitoring of cartilage degeneration in osteoarthritis.

Science.gov (United States)

Sobal, Grazyna; Velusamy, Kavitha; Kosik, Siegfried; Menzel, Johannes; Hacker, Marcus; Pagitz, Maximilian

2016-06-01

In previous in-vitro and ex-vivo studies we proved the specific uptake of (99m)Tc radiolabeled chondroitin sulfate (CS) in human articular cartilage. As a logical next step for the clinical use for imaging osteoarthritis we investigated in-vivo uptake of (99m)TcCS in dogs. The radiolabeling of CS Condrosulf (IBSA, Lugano, Switzerland) was performed using 25mg of CS and 20-40MBq/kg body weight of (99m)Tc by means of the tin method. In-vivo uptake of (99m)TcCS was evaluated in dogs (n=12, castrated males, 4-9years, with 15-51kg body weight). 6 healthy dogs served as controls and 6 with clinical and radiological signs of osteoarthritis in the carpal, elbow, and tarsal joint were examined. The tracer was i.v. injected into the external cephalic vein. The uptake was monitored after 2, 4, 6 and 24h in healthy and osteoarthritic dogs using a planar gamma camera by regional planar or whole body ventral and dorsal acquisition. For whole body scintigraphy animals were under general anesthesia, for planar under sedation only. In healthy control dogs we did not detect any specific uptake of (99m)TcCS in the cartilage. In contrast, in the diseased dogs suffering from osteoarthritis a significant, specific, persistent uptake between 4 and 6h in tarsal, carpal and cubital joints was documented. Median target (joint) to background (mid antebrachium) ratio (T/B) in the OA joints after 4, 6, and 24h was significantly higher than in healthy controls. Target to background ratio using soft tissue as a background (T/S) a similar significantly higher than in healthy controls. In all osteoarthritic joints we found a significant positive correlation (r=0.8, n=20) between grade of disease (I-III) and T/B. When matching radiographic (X ray) changes in osteoarthritic joints (grade II and III) we found also a maximal uptake of (99m)TcCS at the specific anatomical site of highest cartilage degeneration. None of the dogs experienced any side effects. These results suggest that (99m)TcCS might

Distribuição do dextran-99mTc e do carvão ativado no linfonodo-sentinela em coelho = Distribution of dextran-99mTc and activated carbon in sentinel lymph nodes of rabbits

Directory of Open Access Journals (Sweden)

Rocha, Rogério Porto da

2006-01-01

Conclusões: A solução de CA (6% e corante vital (azul patente V na proporção 1: 1 determinou uma fácil identificação do LS no intra-operatório. A análise comparativa da distribuição do CA e do dextran-99mTc demonstra que ambos se comportaram da mesma forma concentrando-se na mesma metade do LS

[Shielding effect of clinical X-ray protector and lead glass against annihilation radiation and gamma rays of 99mTc].

Science.gov (United States)

Fukuda, Atsushi; Koshida, Kichiro; Yamaguchi, Ichiro; Takahashi, Masaaki; Kitabayashi, Keitarou; Matsubara, Kousuke; Noto, Kimiya; Kawabata, Chikako; Nakagawa, Hiroto

2004-12-01

Various pharmaceutical companies in Japan are making radioactive drugs available for positron emission tomography (PET) in hospitals without a cyclotron. With the distribution of these drugs to hospitals, medical check-ups and examinations using PET are expected to increase. However, the safety guidelines for radiation in the new deployment of PET have not been adequately improved. Therefore, we measured the shielding effect of a clinical X-ray protector and lead glass against annihilation radiation and gamma rays of (99m)Tc. We then calculated the shielding effect of a 0.25 mm lead protector, 1 mm lead, and lead glass using the EGS4 (Electron Gamma Shower Version 4) code. The shielding effects of 22-mm lead glass against annihilation radiation and gamma rays of (99m)Tc were approximately 31.5% and 93.3%, respectively. The clinical X-ray protector against annihilation radiation approximately doubled the skin-absorbed dose.

Biokinetic and dosimetry of {sup 99m}Tc-14F7-monoclonal antibody in patients with breast cancer

Energy Technology Data Exchange (ETDEWEB)

Gonzalez, Joaquin; Calderon, Carlos; Pimentel, Gilmara; Oliva, Juan P., E-mail: jgg@infomed.sld.cu [Departmento de Medicina Nuclear, Instituto de Oncologia y Radiobiologia, Cidad Habana (Cuba); Casaco, Angel [Division de Ensayos Clinicos, Centro de Inmunologia Molecular, Reparto Siboney, Ciudad Habana (Cuba)

2008-07-01

Full text: The 14F7 murine MAb is an IgG1 that binds specifically to GM3(Neu-Gc) ganglioside strongly recognizing the antigen displayed in human breast and melanoma tumors. A preliminary report showed in vivo evidences of presence of GM3(Neu-Gc) ganglioside in human breast primary tumors using 14F7 MAb labelled with {sup 99m}Tc. In this work the pharmacokinetics and biodistribution of {sup 99m}Tc-14F7 MAb in patient with breast cancer were studied. The absorbed dose in normal organ and tumors was also calculated. The patients were selected from a Phase I/II clinical trial which included 14 female patients with cytological diagnose of breast carcinoma in stage II without previous onco-specific treatment. Three groups were conformed: Group I (0.3mg, n=5), Group II (1mg, n=5) and Group III (3mg, n=4). The activity ranged in 1.11 - 1.48GBq (30- 40mCi) was intravenously administered during 1-2min. The {sup 99m}Tc-14F7 plasma clearance was determined by blood sampling at 5, 10, 20, 30min and 1, 2, 4, 8 and 24h after injection. All urine excreted by patients was collected during 24h after injection at intervals of 0-2h, 2-8h and 8-24h. Prior to injection, a transmission scan of head, thorax, abdomen and pelvis was obtained using a {sup 57}Co flood source. Anterior and posterior whole body images were acquired at 30min, 2h, 4h, 8h and 24h after injection using a Gamma Camera (SophyCamera DS7) with pinhole collimator. Static anterior and posterior images were obtained from head, thorax, abdomen, pelvis and lateral images of each breast in pendular position at 2h, 4h, 8h and 24h. Internal absorbed dose calculation was performed according to MIRD formalism using the S values for adult non-pregnant female phantom downloaded from the RADAR website. Self-absorbed tumor dose were calculated assuming those as spheres with uniform distribution of activity. The plasma clearance of radiotracer in all groups shows a monoexponential decay behaviour with biological elimination half time

Semi-quantitative analysis of post-transarterial radioembolization 90Y Microsphere position emission tomography combined with computed tomography (PET/CT) images in advance liver malignancy: Comparison with 99mTc macroaggregated albumin (MAA) single photon emission computed tomography (SPECT)

International Nuclear Information System (INIS)

Rhee, Seung Hong; Kim, Sung Eun; Cho, Jae Hyuk; Park, Ju Kyung; Kim, Yun Hwan; Choe, Jae Gol; Eo, Jae Seon; Park, So Yeon; Lee, Eun Sub

2016-01-01

The purpose of this study is to evaluate the correlation between pretreatment planning technetium-99m ( 99 mTc) macroaggregated albumin (MAA) SPECT images and posttreatment transarterial radioembolization (TARE) yttirum-90 ( 90 Y) PET/CT images by comparing the ratios of tumor-to-normal liver counts. Fifty-two patients with advanced hepatic malignancy who underwent 90 Y microsphere radioembolization from January 2010 to December 2012 were retrospectively reviewed. Patients had undergone 99 mTc MAA intraarterial injection SPECT for a pretreatment evaluation of microsphere distribution and therapy planning. After the administration of 90 Y microspheres, the patients underwent posttreatment 90 Y PET/CT within 24 h. For semiquantitative analysis, the tumor-to-normal uptake ratios in 90 Y PET/CT (TNR-yp) and 99 mTc MAA SPECT (TNR-ms) as well as the tumor volumes measured in angiographic CT were obtained and analyzed. The relationship of TNR-yp and TNR-ms was evaluated by Spearman's rank correlation and Wilcoxon's matched pairs test. In a total of 79 lesions of 52 patients, the distribution of microspheres was well demonstrated in both the SPECT and PET/CT images. A good correlation was observed of between TNR-ms and TNR-yp (rho value = 0.648, p < 0.001). The TNR-yp (median 2.78, interquartile range 2.43) tend to show significantly higher values than TNR-ms (median 2.49, interquartile range of 1.55) (p = 0.012). The TNR-yp showed weak correlation with tumor volume (rho = 0.230, p = 0.041). The 99mTc MAA SPECT showed a good correlation with 90 Y PET/CT in TNR values, suggesting that 99 mTc MAA can be used as an adequate pretreatment evaluation method. However, the 99 mTc MAA SPECT image consistently shows lower TNR values compared to 90Y PET/CT, which means the possibility of underestimation of tumorous uptake in the partition dosimetry model using 99 mTc MAA SPECT. Considering that 99 mTc MAA is the only clinically available surrogate marker

Bioaccumulation of sup(95m)Tc in fish and snails

Energy Technology Data Exchange (ETDEWEB)

Blaylock, B.G.; Frank, M.L.; DeAngelis, D.L. (Oak Ridge National Lab., TN (USA))

1982-03-01

Concentration factors for technetium recommended in radiological assessment models for freshwater biota are default values based on the behavior of iodine in the environment. A small experimental freshwater pond was spiked with sup(95m)Tc to obtain data for calculating concentration factors for fish and snails. A model using the pond data was developed to calculate steady-state body burdens for freshwater biota. The concentration factors based on the calculated body burden for carp (Caprinus carpio), mosquitofish (Gambusia affinis), and snails (Helisoma sp.) were 11,75 and 121, respectively. The concentration factor for carp was less than the recommended value of 15 listed in the USNRC Regulatory Guide 1.109 for calculating radiation dose to man; however, the concentration factors for mosquitofish and snails exceeded the recommended values by 5 and 25 times, respectively.

Cyclopentadienyl tricarbonyl complexes of 99mTc for the in vivo imaging of the serotonin 5-HT 1a receptor in the brain

International Nuclear Information System (INIS)

Saidi, Mouldi; Trabelsi, Adel; MEKNI, Abdelkader; Kretzschmar, M.; Sefert, S.; Bergmann, R.; Pietzsch, H.-J.

2005-01-01

The present interest in the 5-HT 1a receptor is due to its implicated role in several major neuropsychiatric disorders such as depression, eating disorders and anxiety. For the diagnosis of these pathophysiological processes it is important to have radioligands in hand able to specifically bind on the 5-HT 1a receptor in order to allow brain imaging. due to the optimal radiation properties of 99mTc there is a considerable interest in the development of 99mTc radiopharmaceuticals for imaging serotonergic CNS receptors using single-photon emission tomography (SPET). Here we introduce two cyclopentadienyl technitium tricarbonyl conjugates of piperidine derivatives which show high accumulation of radioactivity in brain areas rich in 5-HT 1a receptors

Production of the antimicrobial peptide UBI 29-41 labelled with 99mTc by an indirect method

International Nuclear Information System (INIS)

Nevares, Noemi; Crudo, Jose L.; Zapata, Miguel; Castiglia, Silvia G. de

2003-01-01

The infection processes are a major problem in human health causing a high number of human deaths all around the world. Diagnostic imaging in nuclear medicine is an attractive option in the detection of infection processes due to its sensitivity. The antimicrobial peptides are very important in the development of new radiopharmaceuticals, since their antimicrobial activity towards a great variety of microorganisms have been proven. The aim of this work was to obtain the antimicrobial peptide UBI 29-41 labelled with technetium 99 m, by an indirect method via NHS-Hynic and tricine as a coligand, and evaluate its stability and its ability to discriminate between infection and inflammation sites. The radiochemical purity of the labeling procedure was 95.5±1,2 %. The cysteine challenge showed a great stability of the 99mTc UBI-Hynic, and the stability in human serum showed that the 81% of the radioactivity remained bounded to UBI-Hynic at 48 hs of incubation. The bio distribution's studies showed main elimination via kidney of 99mTc UBI-Hynic and the target/non target ratio was 1,81 for infected mice and 1,16 for inflamed mice. (author)

Actions needed to ensure a reliable supply of 99Mo and 99mTc?

International Nuclear Information System (INIS)

Cameron, R.; Peykov, P.

2014-01-01

The NEA established the High-level Group on the Security of Supply of Medical Radioisotopes (HLG-MR) to examine the causes of 99 Mo/ 99 mTc supply shortages in 2009. It undertook an economic analysis and determined that lack of economic sustainability in producing reactors was the major cause of the shortages. From that it developed a policy approach, including principles and supporting recommendations to address those causes. Since then it has looked at the way the supply chain has implemented these policy principles through initiating a self-assessment process, which revealed uneven application and lack of adherence to the key principle of full cost recovery. As part of the analysis, the NEA has also reviewed the global 99 Mo/ 99 mTc supply situation periodically, using the most up-to-date data from supply chain participants, to highlight periods of reduced supply and underscore the case for implementing the HLG-MR policy approach in a timely and globally-consistent manner. This current paper presents the preliminary results from an updated 99 Mo supply and demand forecast, focusing on the potentially critical 2015-2020 period, when two major 99 Mo producers (the NRU reactor in Canada and the OSIRIS reactor in France) are scheduled to cease 99 Mo irradiations. It concludes with a review of the effectiveness of the actions taken to date and indicates where further action is needed. (author)

Rapid and accurate determination of radiochemical purity of sup(99m)Tc compounds

International Nuclear Information System (INIS)

Tamat, S.R.

1977-01-01

The wide spread use of sup(99m)Tc-labelled radiopharmaceuticals and limitation of the short half-life of the isotope, is associated with an urgent need for a rapid, simple but accurate method for determining the radiochemical purity of the compound. A short paper chromatographic (KK) or thin layer chromatographic (KLT) method using 95% methanol or 0.9% saline solution as solvents, has solved the problem. With these methods, the amount of free sup(99m)Tc pertechnetate in a compound, can be determined in only a few minutes. These methods compare satisfactorily with lengtheir procedures. (author)

Determination of Sn in 99{sup m}Tc Radiopharmaceutical Kits by Polarographic Methods; Determinacion de Estano en Radiofarmacos de 99{sup m}Tc mediante Metodos Polarograficos

Energy Technology Data Exchange (ETDEWEB)

Castro, M; Cruz, J; Sanchez, M

2009-07-01

Kits of 99{sup m}Tc radiopharmaceuticals are used in nuclear medicine for diagnosis of different diseases. Sn (II) is one of the essential components in their formulations, which is used for reduction 99{sup m}Tc-pertechnetate in cold kits for on-site preparation 99{sup m}Tc-pertechnetate radiopharmaceuticals. Usually, these cold kits contain different additives (complexing agents, antioxidants, buffers, etc.) and the amount of Sn (II) varies from kit to kit. The determination of Sn in these products is essential in assessing their quality. We report here the development of a new polarographic method for the determination of Sn (II) and total Sn in representative radiopharmaceuticals kits (for the content of Sn and chemical composition) produced at the Center of Isotopes of Cuba (CENTIS). These methods were validated by analysis of variance and recovery techniques. From the results of the validation, the characteristic functions of uncertainties and fits are considered for the established methods, which give the necessary evidences to demonstrate the usefulness of these methods according to the current trends in Analytical Chemistry. This work provides practical results of great importance for CENTIS. After the speciation of Sn in the MAG3 radiopharmaceuticals kit is inferred that the production process is affected by uncontrolled factors that influence in the product stability, which demonstrates the necessity for analytical tools for the characterization of products and processes. (Author) 57 refs.

Bioaccumulation of /sup 95m/Tc in fish and snails

Energy Technology Data Exchange (ETDEWEB)

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

1982-03-01

Concentration factors for technetium recommended in radiological assessment models for freshwater biota are default values based on the behavior of iodine in the environment. In this study a small experimental freshwater pond was spiked with /sup 95/mTc to obtain data for calculating concentration factors for fish and snails. A model using the pond data was developed to calculate steady-state body burdens for freshwater biota. The concentration factors based on the calculated body burden for carp (Caprinus carpio), mosquitofish (Gambusia affinis), and snails (Helisoma sp.) were 11, 75 and 121, respectively. The concentration factor for carp was less than the recommended value of 15 listed in the USNRC Regulatory Guide 1.109 for calculating radiation dose to man; however, the concentration factors for mosquitofish and snails exceeded the recommended values by 5 and 24 times, respectively.

Straight and chopped dc performance data for a Prestolite MTC-4001 motor and a general electric EV-1 controller

Science.gov (United States)

Edie, P. C.

1981-01-01

Performance data on the Prestolite MTC-4001 series wound dc motor and General Electric EV-1 Chopper Controller is supplied for the electric vehicle manufacturer. Data are provided for both straight and chopped dc input to the motor, at 2 motor temperature levels. Testing was done at 6 voltage increments to the motor, and 2 voltage increments to the controller. Data results are presented in both tabular and graphical forms. Tabular information includes motor voltage and current input data, motor speed and torque output data, power data and temperature data. Graphical information includes torque-speed, motor power output-speed, torque-current, and efficiency-speed plots under the various operating conditions. The data resulting from this testing show the speed-torque plots to have the most variance with operating temperature. The maximum motor efficiency is between 76% and 82%, regardless of temperature or mode of operation.

77 FR 53923 - Biweekly Notice;

Science.gov (United States)

2012-09-04

... life (EOL) moderator temperature coefficient (MTC) surveillance requirement (SR) to allow [] the... request would change the near EOL MTC SR to allow [] the required MTC measurement [to be eliminated] under.... This amendment request would change the near EOL MTC SR to allow [] the required MTC measurement to be...

Alcoholic hepatitis with negligible sup(99m)Tc uptake and transient elevation of serum alpha-fetoprotein

International Nuclear Information System (INIS)

Hoshino, Hirosuke; Okumura, Makoto; Shimizu, Masanori; Eimoto, Tadaaki

1981-01-01

A 35 year old male with typical alcoholic hepatitis presented almost negligible uptake of sup(99m)Tc on the liver scan. Electron microscopic findings disclosing decreased number of Kupffer cells and impaired blood flow in the sinusoids may elucidate extremely diminshed uptake of isotope by the liver. Transient elevation of serum α-fetoprotein up to 3200 ng/ml observed during the active stage may indicate a regeneration process of hepatic necrosis occurred following the acute alcoholic hepatitis. (author)

Scintigraphic images of bacterial infection using aptamers directly labeled with {sup 99m}Tc

Energy Technology Data Exchange (ETDEWEB)

Santos, S.R.; Correa, C.R.; Andrade, A.S.R., E-mail: sararoberta7@hotmail.com, E-mail: crisrcorrea@gmail.com, E-mail: antero@cdtn.br [Centro de Desenvolvimento da Tecnologia Nuclear (CDTN/CNEN-MG), Belo Horizonte, MG (Brazil); Barros, A.L.B.; Diniz, S.O.F.; Cardoso, V.N., E-mail: brancodebarros@yahoo.com.br, E-mail: valbertcardoso@yahoo.com.br, E-mail: simoneodilia@yahoo.com.br [Universidade Federal de Minas Gerais (UFMG), Belo Horizonte, MG (Brazil). Faculdade de Farmacia. Departamento de Analises Clinicas e Toxicologicas

2015-07-01

Staphylococcus aureus is specie of great medical importance and is the most commonly agent found in infections of soft tissues, bone infections and bone prostheses. In this study, aptamers selected to S. aureus were labeled by the direct method with {sup 99m}Tc and used for bacterial infection identification by scintigraphy. The radiolabeled aptamers radiochemical purity and stability were assessed by thin-layer chromatography (TLC). Three groups of Swiss mice (n=6) were used for the scintigraphic imaging studies. The first group was infected intramuscularly in the right thigh with S. aureus, the second group with C. albicans and the third group received zymosan to induce aseptic inflammation. After 24 h, radiolabeled aptamers (18 MBq) were injected by the tail vein. Scintigraphic images were acquired at 1 h and 4 h postinjection. The radiolabeling yield with {sup 99m}Tc was over 90%. The radiolabeled aptamers were stable in 0.9% saline, plasma and cysteine excess. The scintigraphic image profiles showed high uptake in the kidneys and bladder in all groups, indicating a main renal excretion consistent with the hydrophilic nature of the molecule. No accumulation of radioactivity was observed in the thyroid, stomach, liver and spleen, indicating acceptable levels of radiochemical impurities. The group infected with S. aureus showed a visible uptake in the infected right thigh at 1 h post-injection. For the control groups (C. albicans and zymosan) visible differences between the right and left thighs were not observed. The radiolabeled aptamers were able to distinguish aseptic inflammation from bacterial infection and bacterial from fungal infection. (author)

The Effect of (99m)Tc on Dual-Energy X-Ray Absorptiometry Measurement of Body Composition and Bone Mineral Density

DEFF Research Database (Denmark)

Fosbøl, Marie Øbro; Dupont, Anders; Alslev, Louise

2012-01-01

the administration of a tracer marked with (99m)Tc were included. The patients underwent a whole-body DXA scan before and within 2h after tracer injection using a GE/Lunar Prodigy scanner. Control scans were performed on 40 volunteers, who had not received any radioactive tracer. In both phantom and patient...

Determination of 99Mo contamination in a nuclear medicine patient submitted to a diagnostic procedure with 99mTc

Directory of Open Access Journals (Sweden)

Bernardo Maranhão Dantas

2005-10-01

Full Text Available 99mTc is a radionuclide widely used for imaging diagnosis in nuclear medicine. In Brazil it is obtained by elution from 99Mo-99mTc generators supplied by the Nuclear Energy Research Institute (IPEN. The elution is carried out in radiopharmacy laboratories located in hospitals and clinics. Depending of the quality of the generator and conditions of use during the elution process, 99Mo can be extracted from the column of the generator, becoming a radionuclidic impurity of the eluate used for the obtention of the radiopharmaceutical to be administered to the patient. 99Mo emits high-energy photons and beta particles and its presence degrades the quality of the image and unnecessarily increases the radiation dose delivered to the patient. An in-vivo measurement technique was developed to verify the occurrence of internal contamination by 99Mo in nuclear medicine patients. Direct measurements were made in a volunteer who underwent myocardial scintigraphy with 99mTc-sestamibi. The results indicated the presence of internal contamination of the patien by 99Mot. The activity was tracked for several days, and an assessment of the radiation dose from the contaminant 99Mo was made.O 99mTc é um radionuclídeo largamente utilizado em diagnósticos por imagem em medicina nuclear. No Brasil, ele é obtido por eluição de um gerador de 99Mo-99mTc fornecido pelo IPEN. A eluição do gerador é feita nas clínicas onde se realizam os exames. Durante a eluição o 99Mo pode ser carreado da coluna, tornando-se uma impureza radionuclídica do eluato a ser utilizado para a obtenção do radiofármaco administrado ao paciente. O 99Mo emite fótons de alta energia e partículas beta, e sua presença, além de provocar degradação na qualidade da imagem do exame, aumenta desnecessariamente a dose de radiação no paciente. Assim, com o objetivo de verificar a possível ocorrência de contaminação interna por 99Mo em pacientes de medicina nuclear, foi desenvolvida

Computer assisted analysis of sup(99m)Tc pyrophosphate bone uptake in Paget's disease

International Nuclear Information System (INIS)

Maayan, M.L.; Eisenberg, J.; Volpert, E.; Shai, F.; Mroczek, R.

1982-01-01

The present clinical study describes a method of evaluation of Paget's disease bone by computer assisted analysis of activity curves obtained over normal and pathological portions of the skeleton in the same patient. The data obtained lead to a differential diagnosis between Paget's and metastatic disease of the bone, as well as an evaluation of subsequent therapy. The results indicate a higher bone activity, (expressed by bone flow and bone uptake, of sup(99m)Tc pyrophosphate) in Paget's than in metastatic disease of the bone, as well as a normalization of these parameters after prolonged therapy of Paget's patients with salmon calcitonin

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.

Semi-quantitative analysis of post-transarterial radioembolization {sup 90}Y Microsphere position emission tomography combined with computed tomography (PET/CT) images in advance liver malignancy: Comparison with {sup 99m}Tc macroaggregated albumin (MAA) single photon emission computed tomography (SPECT)

Energy Technology Data Exchange (ETDEWEB)

Rhee, Seung Hong; Kim, Sung Eun; Cho, Jae Hyuk; Park, Ju Kyung; Kim, Yun Hwan; Choe, Jae Gol [Korea University Anam Hospital, Seoul (Korea, Republic of); Eo, Jae Seon; Park, So Yeon; Lee, Eun Sub [Dept. of Nuclear Medicine, Korea University Guro Hospital, Seoul (Korea, Republic of)

2016-03-15

The purpose of this study is to evaluate the correlation between pretreatment planning technetium-99m ({sup 99}mTc) macroaggregated albumin (MAA) SPECT images and posttreatment transarterial radioembolization (TARE) yttirum-90 ({sup 90}Y) PET/CT images by comparing the ratios of tumor-to-normal liver counts. Fifty-two patients with advanced hepatic malignancy who underwent {sup 90}Y microsphere radioembolization from January 2010 to December 2012 were retrospectively reviewed. Patients had undergone {sup 99}mTc MAA intraarterial injection SPECT for a pretreatment evaluation of microsphere distribution and therapy planning. After the administration of {sup 90}Y microspheres, the patients underwent posttreatment {sup 90}Y PET/CT within 24 h. For semiquantitative analysis, the tumor-to-normal uptake ratios in {sup 90}Y PET/CT (TNR-yp) and {sup 99}mTc MAA SPECT (TNR-ms) as well as the tumor volumes measured in angiographic CT were obtained and analyzed. The relationship of TNR-yp and TNR-ms was evaluated by Spearman's rank correlation and Wilcoxon's matched pairs test. In a total of 79 lesions of 52 patients, the distribution of microspheres was well demonstrated in both the SPECT and PET/CT images. A good correlation was observed of between TNR-ms and TNR-yp (rho value = 0.648, p < 0.001). The TNR-yp (median 2.78, interquartile range 2.43) tend to show significantly higher values than TNR-ms (median 2.49, interquartile range of 1.55) (p = 0.012). The TNR-yp showed weak correlation with tumor volume (rho = 0.230, p = 0.041). The 99mTc MAA SPECT showed a good correlation with {sup 90}Y PET/CT in TNR values, suggesting that {sup 99}mTc MAA can be used as an adequate pretreatment evaluation method. However, the {sup 99}mTc MAA SPECT image consistently shows lower TNR values compared to 90Y PET/CT, which means the possibility of underestimation of tumorous uptake in the partition dosimetry model using {sup 99}mTc MAA SPECT. Considering that

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)

Role of scintiscan studies of the esophagus in the diagnosis of related functional disorders

International Nuclear Information System (INIS)

Seidl, I.

1985-01-01

Radionuclide studies of the esophagus (by measuring the passage of a bolus of 99m-Tc DTPA and subsequent reflux tests) were carried out in a cohort of 248 patients, where the underlying pathological changes varied between individuals. In terms of sensitivity, this method was superior to mere reflux measurements and long-term pH determinations - just as well as to histological, endoscopic and simple X-ray examinations. Disorders of the esophageal function can mostly not be predicted from the clinical symptoms and signs alone. if esophageal function studies are combined with radionuclide examinations of gastric emptying, esophageal disorders are revealed in about 50% of cases showing deviations of the gastric emptying rate in either direction. It deserves to be mentioned here that this is quite independent of the level of gastric secretion. The results obtained have shown that esophageal function studies in combination with reflux tests are an invaluable technique of screening for esophageal function disorders. (TRV) [de

Internal Dosimetry and the pharmacokinetic of the Cuban Kit of Methoxy-Isobutyl-Isonitrile (MIBI) marked with 99mTc

International Nuclear Information System (INIS)

Torres, L.A.; Pereztol, O.; Rodriguez, J.L.; Alvarez, I.; Fraxedas, R.; Mesa, G.; Rodriguez, R.

1998-01-01

The objective of the present work consisted on evaluating the Internal Dosimetry and the pharmacokinetic of the Cuban Kit of Methoxy-Isobutyl-Isonitrile (MIBI) marked with 99mTc. In the dosimetry studies and biodistribution five healthy volunteers were included and in the pharmacokinetic studies five patients were included with less than 5% of probability of suffering illness of artery coronary

Contribution to the study of pertechnetate (sup(99m)Tc) stannous citrate - citric acid complexation

International Nuclear Information System (INIS)

Calmes, E.-P.

1978-03-01

Pertechnetate/citric acid/stannous citrate complexation carried out from a lyophilisate of stannous citrate in citric medium at pH5 leads to the formation of separable compounds. These compounds are tin-free technetium citrates. Similar results have been described in the case of complexation reactions with glycolic, thioglycolic and thiomalic acids and with other carboxylates such as dimercaptosuccinic acid. These processes include the reduction of Tcsup(VIII) by Snsup(II) in the presence of thiomalic acid under conditions similar to our own: stannous thiomalate in thiomalic medium to which is added the pertechnetate solution producing Tc-thiomalate complexes variable with the reaction pH. Also worth considering is the possible complexation between pertechnetate and the same acid in the absence of reducing ion, following a special procedure (heating). The complexes described here contain the oxotechnetium bond (terminal oxygen-technetium) and a strong probability exists in favour of dimerisation. Their stability, for a reaction in acid solution: pH 5.0/5.5, becomes satisfactory if: the solution is concentrated enough; bubbling by an inert gas is carried out; room temperature is not exceeded. The development takes place through a partial reoxidation characterised by colour change. An original interaction between reduced states of Tc and citric acid may be claimed with certainty under our experimental conditions. The difficulty then lies in the passage to the tracer stage when the isotope sup(99m)Tc is used [fr

Direct elution of sup(99m)Tc complexes from neutron irradiation produced 99Mo incorporated in a MoCl2-MoBr2 mixture

International Nuclear Information System (INIS)

Ganzerli Valentini, M.T.; Stella, R.; Genova, N.

1987-01-01

A novel type of sup(99m)Tc generator, enabling radiopharmaceutical preparation without reductant addition, was prepared and tested. Neutron activated product 99 Mo, in the form of dichloride cluster, was incorporated into inactive molybdenum dichloride-dibromide mixture (MCB) that was left to settle over an activated alumina layer. Direct elution with aqueous ligands such as salicylate or iminodiacetate derivatives in the pH range 6.5-7.5 yielded chemically stable sup(99m)Tc complexes accompanied by small amounts of secondary products (mostly sup(99m)TcO - 4 ). Pentavalent oxidation state in the salicylate complex and tervalent in the iminodiacetate (IDA) and in the N-(2,6-dimethylphenylcarbamoylmethyl) iminodiacetate (HIDA) complexes were assigned to the element after comparison with reference complexes. The anion exchange version of reverse-phase HPLC was used to resolve the eluted product mixture. (author)

Performance tests on column materials for {sup 99}Mo-{sup 99m}Tc generator

Energy Technology Data Exchange (ETDEWEB)

Sombrito, E Z; Bulos, A D; Tangonan, M C [Chemistry Research Section, Atomic Research Div., Philippine Nuclear Research Inst., Quezon (Philippines)

1998-10-01

To meet the need of producing a {sup 99}Mo-{sup 99m}Tc generator, based on low specific activity reactor-produced {sup 99}Mo, different procedures for preparing zirconium molybdate gels were tested. Performance tests were done on molybdate gel columns prepared using the procedures developed by Vietnam and China, and recently, on a polyzirconium compound (PZC) prepared in Japan. The conditions for the batch drying of a large volume of the gel material were studied as well as the conditions in preparing a column to concentrate technetium-99m. The performance of PZC sample as column material for the generator was also evaluated. (author)

Distribution of orally administered and chronically fed /sup 95m/Tc in Japanese quail tissues and eggs

International Nuclear Information System (INIS)

Thomas, J.M.; Cadwell, L.L.; Garland, T.R.; Cataldo, D.A.

1984-10-01

Previous coefficients for transfer of technetium from feed to poultry have utilized default values. These investigations examined the uptake and distribution of /sup 95m/Tc in male and female Japanese quail following their ingestion of Tc incorporated into alfalfa during growth. Approximately 8% of the daily ingested Tc was transferred to eggs. Biological half-time was one to two days. After 10 days of feeding, 80% of the Tc was in yolk, 20% in albumin, and less than 1% in shell and associated membranes. The Tc levels in albumin reached a maximum between three and five days, compared to six to seven days for yolk. Laying female quail contained 27% of the daily-ingested Tc compared to 5% for males. However, approximately 23% of the daily female Tc intake was contained in the developing ova and reproductive organs. The highest Tc concentrations were in oocytes of laying hens, followed by the fully formed unlaid egg and the ovaries. The uterine shelled egg contained five times the amount of Tc present in other edible tissues combined. For males, the gizzard contained about 53% of the Tc in other edible tissues, followed by muscle (25%), liver (19%), and heart (3%). The transfer coefficient (pCi/kg edible tissue per pCi/day) for plant-incorporated /sup 95m/Tc was about 0.35 day/kg for both sexes. 17 references, 4 tables

The effects of exercise under hypoxia on cognitive function.

Directory of Open Access Journals (Sweden)

Soichi Ando

Full Text Available Increasing evidence suggests that cognitive function improves during a single bout of moderate exercise. In contrast, exercise under hypoxia may compromise the availability of oxygen. Given that brain function and tissue integrity are dependent on a continuous and sufficient oxygen supply, exercise under hypoxia may impair cognitive function. However, it remains unclear how exercise under hypoxia affects cognitive function. The purpose of this study was to examine the effects of exercise under different levels of hypoxia on cognitive function. Twelve participants performed a cognitive task at rest and during exercise at various fractions of inspired oxygen (FIO2: 0.209, 0.18, and 0.15. Exercise intensity corresponded to 60% of peak oxygen uptake under normoxia. The participants performed a Go/No-Go task requiring executive control. Cognitive function was evaluated using the speed of response (reaction time and response accuracy. We monitored pulse oximetric saturation (SpO2 and cerebral oxygenation to assess oxygen availability. SpO2 and cerebral oxygenation progressively decreased during exercise as the FIO2 level decreased. Nevertheless, the reaction time in the Go-trial significantly decreased during moderate exercise. Hypoxia did not affect reaction time. Neither exercise nor difference in FIO2 level affected response accuracy. An additional experiment indicated that cognitive function was not altered without exercise. These results suggest that the improvement in cognitive function is attributable to exercise, and that hypoxia has no effects on cognitive function at least under the present experimental condition. Exercise-cognition interaction should be further investigated under various environmental and exercise conditions.

The standardization methods of radioactive sources (125I, 131I, 99mTc, and 18F) for calibrating nuclear medicine equipment in Indonesia

Science.gov (United States)

Wurdiyanto, G.; Candra, H.

2016-03-01

The standardization of radioactive sources (125I, 131I, 99mTc and 18F) to calibrate the nuclear medicine equipment had been carried out in PTKMR-BATAN. This is necessary because the radioactive sources used in the field of nuclear medicine has a very short half-life in other that to obtain a quality measurement results require special treatment. Besides that, the use of nuclear medicine techniques in Indonesia develop rapidly. All the radioactive sources were prepared by gravimetric methods. Standardization of 125I has been carried out by photon- photon coincidence methods, while the others have been carried out by gamma spectrometry methods. The standar sources are used to calibrate a Capintec CRC-7BT radionuclide calibrator. The results shows that calibration factor for Capintec CRC-7BT dose calibrator is 1,03; 1,02; 1,06; and 1,04 for 125I, 131I, 99mTc and 18F respectively, by about 5 to 6% of the expanded uncertainties.

An exploratory study on 99mTc-RGD-BBN peptide scintimammography in the assessment of breast malignant lesions compared to 99mTc-3P4-RGD2.

Directory of Open Access Journals (Sweden)

Qianqian Chen

Full Text Available This study aimed to explore the diagnostic performance of single photon emission computed tomography / computerized tomography (SPECT/CT using a new radiotracer 99mTc-RGD-BBN for breast malignant tumor compared with 99mTc-3P4-RGD2.6 female patients with breast malignant tumors diagnosed by fine needle aspiration cytology biopsy (FNAB who were scheduled to undergo surgery were included in the study. 99mTc-3P4-RGD2 and 99mTc-RGD-BBN were performed with single photon emission computed tomography (SPECT at 1 hour after intravenous injection of 299 ± 30 MBq and 293 ± 32 MBq of radiotracers respectively at separate day. The results were evaluated by the Tumor to non-Tumor ratios (T/NT. 99mTc-RGD-BBN and 99mTc-3P4-RGD2 SPECT/CT images were interpreted independently by 3 experienced nuclear medicine physicians using a 3-point scale system. All of the samples were analyzed immunohistochemically to evaluate the integrin αvβ3 and gastrin-releasing peptide receptor (GRPR expression. The safety, biodistribution and radiation dosimetry of 99mTc-RGD-BBN were also evaluated in the healthy volunteers.No serious adverse events were reported in any of the patients during the study. The effective radiation dose entirely conformed to the relevant standards. A total of 6 palpable malignant lesions were detected using 99mTc-RGD-BBN SPECT/CT with clear uptake. All malignant lesions were also detected using 99mTc-3P4-RGD2 SPECT/CT. The results showed that five malignant lesions were with clear uptake and the other one with barely an uptake. 4 malignant cases were found with both αvβ3 and GRPR expression, 1 case with only GRPR positive expression (integrin αvβ3 negative and 1 case with only integrin αvβ3 positive expression (GRPR negative.99mTc-RGD-BBN is a safe agent for detecting breast cancer. 99mTc-RGD-BBN may have the potential to make up for the deficiency of 99mTc-3P4-RGD2 in the detection of breast cancer with only GRPR positive expression (integrin �

The effect of dimethyl sulfoxide on the induction of DNA strand breaks in plasmid DNA and colony formation of PC Cl3 mammalian cells by alpha-, beta-, and Auger electron emitters (223)Ra, (188)Re, and (99m)Tc.

Science.gov (United States)

Runge, Roswitha; Oehme, Liane; Kotzerke, Jörg; Freudenberg, Robert

2016-12-01

DNA damage occurs as a consequence of both direct and indirect effects of ionizing radiation. The severity of DNA damage depends on the physical characteristics of the radiation quality, e.g., the linear energy transfer (LET). There are still contrary findings regarding direct or indirect interactions of high-LET emitters with DNA. Our aim is to determine DNA damage and the effect on cellular survival induced by (223)Ra compared to (188)Re and (99m)Tc modulated by the radical scavenger dimethyl sulfoxide (DMSO). Radioactive solutions of (223)Ra, (188)Re, or (99m)Tc were added to either plasmid DNA or to PC Cl3 cells in the absence or presence of DMSO. Following irradiation, single strand breaks (SSB) and double strand breaks (DSB) in plasmid DNA were analyzed by gel electrophoresis. To determine the radiosensitivity of the rat thyroid cell line (PC Cl3), survival curves were performed using the colony formation assay. Exposure to 120 Gy of (223)Ra, (188)Re, or (99m)Tc leads to maximal yields of SSB (80 %) in plasmid DNA. Irradiation with 540 Gy (223)Ra and 500 Gy (188)Re or (99m)Tc induced 40, 28, and 64 % linear plasmid conformations, respectively. DMSO prevented the SSB and DSB in a similar way for all radionuclides. However, with the α-emitter (223)Ra, a low level of DSB could not be prevented by DMSO. Irradiation of PC Cl3 cells with (223)Ra, (188)Re, and (99m)Tc pre-incubated with DMSO revealed enhanced survival fractions (SF) in comparison to treatment without DMSO. Protection factors (PF) were calculated using the fitted survival curves. These factors are 1.23 ± 0.04, 1.20 ± 0.19, and 1.34 ± 0.05 for (223)Ra, (188)Re, and (99m)Tc, respectively. For (223)Ra, as well as for (188)Re and (99m)Tc, dose-dependent radiation effects were found applicable for plasmid DNA and PC Cl3 cells. The radioprotection by DMSO was in the same range for high- and low-LET emitter. Overall, the results indicate the contribution of mainly indirect radiation

Experience in infection images with new radio antibiotic the {sup 99m}Tc-ceftizoxime (TCF); Experiencia en imagenes de infecciones con un nuevo radio-antibiotico la ceftizoxima-{sup 99m}Tc (CFT)

Energy Technology Data Exchange (ETDEWEB)

Soroa, Victoria E; Rabiller, Graciela; Velasquez Espeche, Maria del H. [Comision Nacional de Energia Atomica, Buenos Aires (Argentina). Centro de Medicina Nuclear; Fioriolli, Marcelo H; Rodriguez, Hernan [Hospital de Clinicas Jose de San Martin, Buenos Aires (Argentina); Roca, Manuel; Martin-Comin, Joseph [Hospital Universitario Bellvitge, Barcelona (Spain). Servicio de Medicina Nuclear

2004-07-01

Previous results obtained in the detection of infections with {sup 99m}Tc-ceftizoxime encourage to the group of work to investigate the behavior of an antibiotic of third generation: the ceftizoxime radiolabelled with {sup 99m}Tc and to compare it with other radio-labels in different infectious / inflammatory pathologies. [Spanish] Anteriores resultados obtenidos en la deteccion de infecciones con el {sup 99m}TC-ceftizoxima incentivo al grupo de trabajo a investigar el comportamiento de un antibiotico de tercera generacion: la ceftizoxima radiomarcada con {sup 99m}Tc y compararlo con otros radiomarcadores en diferentes patologias infecciosas/inflamatorias.

Use of {sup 99m}Tc 2-methoxyisobutyl isonitrile in minimally invasive radioguided surgery in patients with primary hyperparathyroidism: A narrative review of the current literature

Energy Technology Data Exchange (ETDEWEB)

Denmeade, Kristie A [Nuclear Medicine and Ultrasound Department, Bankstown-Lidcombe Hospital, Bankstown, New South Wales (Australia); Constable, Chris [Brain and Mind Research Institute, University of Sydney, New South Wales (Australia); Reed, Warren M [Discipline of Medical Radiation Sciences, Faculty of Health Sciences, The University of Sydney, New South Wales (Australia); Nuclear Medicine and Ultrasound Department, Bankstown-Lidcombe Hospital, Bankstown, New South Wales (Australia)

2013-06-15

The use of technetium-99m 2-methoxyisobutyl isonitrile ({sup 99m}Tc MIBI) for assistance in minimally invasive radioguided surgery (MIRS) is growing in popularity as a safe, effective, and proficient technique used for parathyroidectomy in primary hyperparathyroidism (PHPT) treatment. Previously, the preferred treatment for PHPT was bilateral neck exploration (BNE), a very invasive, costly, and lengthy procedure. However, as a large majority (80–85% of cases of PHPT) are attributed to a single parathyroid adenoma (PA), a simpler more direct technique such as MIRS is a far better option. The following article is an exploration of the current literature concerning varied protocols utilizing {sup 99m}Tc MIBI for assistance in MIRS for patients undergoing treatment of PHPT. This technique boasts many advantageous outcomes for patients suffering from PHPT. These include a reduction in cost, operating time, and patient recovery; less evidence of post-surgical hypocalcaemia, less pain, and complications; superior cosmetic results; same-day discharge; and the possibility of local anaesthesia which is particularly beneficial in elderly patients. Better outcomes for patients with deep or ectopic PAs, reduced intra-operative complications, and improved cosmetic outcomes for patients who have previously undergone thyroid and/or parathyroid surgery are also advantageous. Of the literature reviewed it was also found that no patients suffered any major surgical complications such as laryngeal nerve palsy or permanent hypoparathyroidism using {sup 99m}Tc MIBI for assistance in MIRS.

(99m)Tc-3PRGD 2 SPECT/CT predicts the outcome of advanced nonsquamous non-small cell lung cancer receiving chemoradiotherapy plus bevacizumab.

Science.gov (United States)

Ma, Qingjie; Min, Kaiyin; Wang, Ting; Chen, Bin; Wen, Qiang; Wang, Fan; Ji, Tiefeng; Gao, Shi

2015-07-01

Functional imaging can help clinicians assess the individual response of advanced nonsquamous non-small cell lung cancer (NSCLC) to chemoradiation therapy plus bevacizumab. Our purpose is to investigate the ability of (99m)Tc-3PRGD2 single photon emission computed tomography/computed tomography (SPECT/CT) in predicting the early response to treatment. Patients with advanced nonsquamous NSCLC diagnosed by histological or cytological examination were imaged with (99m)Tc-3PRGD2 SPECT/CT at 3 time points: 1-3 days before the start of treatment (SPECT1), 40 Gy radiotherapy with 2 cycles of chemotherapy plus bevacizumab (SPECT2) and 4 weeks after chemoradiotherapy plus bevacizumab (SPECT3). The images were evaluated semiquantitatively by measuring the tumor to non-tumor ratio (T/N) and calculating the percentage change in T/N ratio. Short-term outcome was assessed by the treatment response evaluation according to the Response Evaluation Criteria in Solid Tumors criteria as: complete response (CR), partial response (PR), stable disease (SD) and progressive disease (PD). Patients were divided two groups: responders (CR and PR) and nonresponders (SD and PD). To determine a threshold for percent reduction in T/N ratios, receiver-operating characteristic (ROC) curve analysis was used. Patients were grouped again based on the threshold of P1 (the change percentage from SPECT1 to SPECT2) and P2 (the change percentage from SPECT1 to SPECT3): P1 responders and P1 nonresponders; P2 responders and P2 nonresponders. Patients were followed up starting 4 weeks after completion of therapy and then every 3 months for the first 2 years and every 6 months after 2 years. OS of P1 responders, P1 nonresponders, P2 responders and P2 nonresponders was estimated and graphically illustrated using the Kaplan-Meier method and the log-rank test was used to test the null hypotheses of equal OS in subgroups of patients. A total of 28 patients completed all imaging and treatment. All primary

Scintigraphic discrimination of infections from cancer with 67Ga citrate and sup(99m)Tc pertechnetate

International Nuclear Information System (INIS)

Okuyama, Shinichi; Ito, Yasuhiko; Sato, Tachio

1977-01-01

A paralleled study was carried out on lung cancer and infectious lesions by scintigraphy with 67 Ga citrate and sup(99m)Tc pertechnetate. Malignancies were Ga-positive but Tc-negative whilest infective lesions were positive with both radioisotopes. The technic is simple and yet unique in that it employs radioisotopic uptake ratios which were computed by recording radioactivity over such lesions and over appropriate control sites. This technic may offer a prompt and prospective means of making a differential diagnosis of lung cancer and active lung abscesses. Confirmative value of lesion to control region counting ratio was also emphasized. (auth.)

Principle of cerebral hemodynamic perfusion in SPECT and new evaluation method of hemodynamic reserve capacity using {sup 99m}Tc tracer

Energy Technology Data Exchange (ETDEWEB)

Hashimoto, Masaaki; Mukai, Hironobu; Tada, Motoyuki; Miyazaki, Yoshiharu; Takimoto, Masamori; Shiozaki, Jun; Inoue, Hisashi [Noto General Hospital, Nanao, Ishikawa (Japan)

2002-07-01

We performed quantitative measurements of cerebral blood flow (CBF) using {sup 99m}Tc tracer by the Patlak Plot method with reference to normal aging and cerebrovascular reserve (CVR) capacity and then investigated a new evaluation method of CVR. Aging and decrease of ADL were significantly associated with reduction of the mean hemispheric CBF. In the acetazolamide (ACZ) stress test, these retrospective data showed some overlap in each ischemic grade on the relationship between rCBF and CVR response for the predictability of EC/IC bypass surgery. In these controversial problems, we must reconfirm the principle of cerebral hemodynamic perfusion in SPECT. First, retention tracer is distributed via the microcirculatory system to brain tissue. Second, therefore, we should understand not only the circulation of major vessels, but also the dynamics and rheology in parenchymal microcirculation to determine brain SPECT and CVR capacity. In the next step, we approached the new evaluation method of CVR capacity using {sup 99m}Tc tracer by a serial dynamic SPECT with a slip-ring rotational gamma camera. These preliminally findings suggest that a serial dynamic SPECT may be more useful for analyzing the pathophysiology on brain circulation and CVR than conventional approaches. (author)

Intrathoracic extramedullary hematopoiesis: appearance on /sup 99m/Tc sulfur colloid marrow scan

International Nuclear Information System (INIS)

Bronn, L.J.; Paquelet, J.R.; Tetalman, M.R.

1980-01-01

Imaging of the bone marrow by radionuclide scanning was performed using colloids, which are phagocytized by the reticuloendothelial cells of the marrow, or radioiron, which is incorporated into reticulocytes. The use of the former radiopharmaceutical is based on the assumption, generally valid except in aplastic states or after irradiation, that the distribution of hematopoietic and reticuloendothelial tissue in the marrow is similar. Regardless of the method used, active adult marrow is normally distributed only in the axial skeleton and proximal humeri and femurs. Marrow imaging has been used in the evaluation of myeloproliferative disorders, leukemia, lymphoma, aplastic states, malignancy metastatic to marrow, and hemolytic anemia. We report a case of thalassemia major in which the diagnosis of intrathoracic extramedullary hematopoiesis was confirmed with the /sup 99m/Tc sulfur colloid bone marrow scan

Studies of labelling conditions for gentamicin with sup(99m)Tc. Complexation with ruthexium. Establishment of pharmacokinetics parameters through compartmental analysis

International Nuclear Information System (INIS)

Carvalho, O.G. de.

1988-01-01

Gentamicin sulphate is an aminoglycoside antibiotic type specifically used for treatment of infections produced by Gram-negative bacterias but at the other hand it presents ototoxic reactions as a serious side effect. The main purpose of labelling gentamicin with sup(99m)Tc was to obtain a radioactive tracer to carry out biological studies and compartmental analysis of this antibiotic. The optimal labelling conditions of gentamicin sulphate with sup(99m)Tc, using sodium pertechnetate solution eluted from a sup(99)Mo- sup(99m)Tc generator, were stablished by testing different masses of antibiotic, and reduction agent (SnCl sub(2).2H sub(2)O), and also different reaction time and final labelling PH. The same labelling procedure was used with Re (amonium perrenate) in order to obtain some semi-quantitative approximations of the chemical structure of the complex formed, since Re and Tc present similar chemical characteristics. In this way it is possible to suggest the role that the groups NH2 and C-O bonding of the gentamicin play in the complexation process. From the studies of the biological uptake of sup(99m)Tc-gentamicin sulphate in rats, the kidneys showed the highest affinity for the antibiotic. The maximum uptake was observed in 180 to 240 minutes followed by a decrease of it afterwards. For the dose and time used, no significative uptake by the auricular region was detected. Curve of plasma decay of sup(99m)Tc-gentamicin was obtained, and from the exponentials of each beanch of this curve respective half-lives were calculated. Furthermore the apparent volume of distribution was determined, and with the residual radioactivity in the body, the biological half-life and total clearance were obtained. The distribution of sup(99m)Tc-gentamicin in rats was set in a bi-compartments in addition to a retention one for the 24 hours time interval studied. (author)

Direct elution of sup(99m)Tc complexes from neutron irradiation produced /sup 99/Mo incorporated in a MoCl/sub 2/-MoBr/sub 2/ mixture

Energy Technology Data Exchange (ETDEWEB)

Ganzerli Valentini, M.T.; Stella, R.; Genova, N.

1987-01-01

A novel type of sup(99m)Tc generator, enabling radiopharmaceutical preparation without reductant addition, was prepared and tested. Neutron activated product /sup 99/Mo, in the form of dichloride cluster, was incorporated into inactive molybdenum dichloride-dibromide mixture (MCB) that was left to settle over an activated alumina layer. Direct elution with aqueous ligands such as salicylate or iminodiacetate derivatives in the pH range 6.5-7.5 yielded chemically stable sup(99m)Tc complexes accompanied by small amounts of secondary products (mostly sup(99m)TcO/sup -//sub 4/). Pentavalent oxidation state in the salicylate complex and tervalent in the iminodiacetate (IDA) and in the N-(2,6-dimethylphenylcarbamoylmethyl) iminodiacetate (HIDA) complexes were assigned to the element after comparison with reference complexes. The anion exchange version of reverse-phase HPLC was used to resolve the eluted product mixture.

'99Mo/99mTc Generator Based on High Radionuclidic Pure Zirconium Molybdate Gel

International Nuclear Information System (INIS)

Amin, M.; Mostafa, M.; El-Amir, M.A.; El-Absy, M.A.; Mohamed, O.I.; Farag, A.B.

2014-01-01

99 Mo / 99 mTc radioisotope generator was prepared using in-situ precipitated zirconium molybdate chromatographic column. Zirconium molybdate gel matrix was synthesized by precipitation of neutron activation molybdenum-99 from its solution after variety purification processes to prevent contamination of the 99m Tc eluate with cross-contaminants. Greeter than 82.7 ± 0.4 % of the generated 99m Tc was immediately and reproducible eluted by passing 10 ml 0.9 % NaCl solution through the 1 g zirconium molybdate- 99 Mo column matrix at a flow rate of 0.5 ml / min and room temperature with high chemical, radionuclide ( ≥ 99.9 % 99m Tc) and radiochemical purity ( ≥ 97.7 % % as 99 mTcO 4 - ) with ph value suitable for medical uses.

Can technetium-labelled millimicrospheres be used to measure Kupffer-cell function

International Nuclear Information System (INIS)

Pearson, H.J.; Chamberlain, J.; Anderson, J.; Bowry, V.; Bell, P.R.F.

1985-01-01

It has been suggested that sodium pertechnetate sup(99m)Tc millimicrospheres can be used to measure Kupffercell function. We studied animals and humans to show whether the clearance and catabolism of sup(99m)Tc-labelled millimicrospheres can be used as a measure of Kupffer-cell function. Comparison with albumin 125 I-microaggregates clearance of human serum albumin failed to demonstrate that they can be used for this purpose. We suggest that their blood clearance is mainly an expression of liver blood flow. (orig.)

Simultaneous acquisition of (99m)Tc- and (123)I-labeled radiotracers using a preclinical SPECT scanner with CZT detectors.

Science.gov (United States)

Kobayashi, Masato; Matsunari, Ichiro; Nishi, Kodai; Mizutani, Asuka; Miyazaki, Yoshiharu; Ogai, Kazuhiro; Sugama, Jyunko; Shiba, Kazuhiro; Kawai, Keiichi; Kinuya, Seigo

2016-05-01

Simultaneous acquisition of (99m)Tc and (123)I was evaluated using a preclinical SPECT scanner with cadmium zinc telluride (CZT)-based detectors. 10-ml cylindrical syringes contained about 37 MBq (99m)Tc-tetrofosmin ((99m)Tc-TF) or 37 MBq (123)I-15-(p-iodophenyl)-3R,S-methyl pentadecanoic acid ((123)I-BMIPP) were used to assess the relationship between these SPECT radioactive counts and radioactivity. Two 10-ml syringes contained 100 or 300 MBq (99m)Tc-TF and 100 MBq (123)I-BMIPP to assess the influence of (99m)Tc upscatter and (123)I downscatter, respectively. A rat-sized cylindrical phantom also contained both 100 or 300 MBq (99m)Tc-TF and 100 MBq (123)I-BMIPP. The two 10-ml syringes and phantom were scanned using a pinhole collimator for rats. Myocardial infarction model rats were examined using 300 MBq (99m)Tc-TF and 100 MBq (123)I-BMIPP. Two 1-ml syringes contained 105 MBq (99m)Tc-labeled hexamethylpropyleneamine oxime ((99m)Tc-HMPAO) and 35 MBq (123)I-labeled N-ω-fluoropropyl-2β-carbomethoxy-3β-(4-iodophenyl) nortropane ((123)I-FP-CIT). The two 1-ml syringes were scanned using a pinhole collimator for mice. Normal mice were examined using 105 MBq (99m)Tc-HMPAO and 35 MBq (123)I-FP-CIT. The relationship between SPECT radioactive counts and radioactivity was excellent. Downscatter contamination of (123)I-BMIPP exhibited fewer radioactive counts for 300 MBq (99m)Tc-TF without scatter correction (SC) in 125-150 keV. There was no upscatter contamination of (99m)Tc-TF in 150-175 keV. In the rat-sized phantom, the radioactive count ratio decreased to 4.0 % for 300 MBq (99m)Tc-TF without SC in 125-150 keV. In the rats, myocardial images and radioactive counts of (99m)Tc-TF with the dual tracer were identical to those of the (99m)Tc-TF single injection. Downscatter contamination of (123)I-FP-CIT was 4.2 % without SC in 125-150 keV. In the first injection of (99m)Tc-HMPAO and second injection of (123)I-FP-CIT, brain images and radioactive counts

Clinical Comparison of 99mTc Exametazime and 123I Ioflupane SPECT in Patients with Chronic Mild Traumatic Brain Injury

OpenAIRE

Newberg, Andrew B.; Serruya, Mijail; Gepty, Andrew; Intenzo, Charles; Lewis, Todd; Amen, Daniel; Russell, David S.; Wintering, Nancy

2014-01-01

BACKGROUND: This study evaluated the clinical interpretations of single photon emission computed tomography (SPECT) using a cerebral blood flow and a dopamine transporter tracer in patients with chronic mild traumatic brain injury (TBI). The goal was to determine how these two different scan might be used and compared to each other in this patient population. METHODS AND FINDINGS: Twenty-five patients with persistent symptoms after a mild TBI underwent SPECT with both (99m)Tc exametazime to m...

Under used technetium-99m generators

International Nuclear Information System (INIS)

Mushtaq, A.

2001-01-01

Health care reform truly has become a global issue and it will undoubtedly have a dramatic impact on the future of nuclear medicine business in particular. A bigger concern within the nuclear medicine community is its competitiveness with other modalities and cost effectiveness.Technetium-99m and its generators are playing key role for the majority of diagnostic scans performed in the world today. Availability of ''9''9''mTc can be increased if it is separated from ''9''9Mo after much shorter growth times. After proper planning with the extra ''9''9''mTc, a significant number of scans can be performed or we would be able to order approximately 30% low activity ''9''9Tc generators to fulfill our requirements

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

Exploring the potential of a structural alphabet-based tool for mining multiple target conformations and target flexibility insight.

Science.gov (United States)

Regad, Leslie; Chéron, Jean-Baptiste; Triki, Dhoha; Senac, Caroline; Flatters, Delphine; Camproux, Anne-Claude

2017-01-01

Protein flexibility is often implied in binding with different partners and is essential for protein function. The growing number of macromolecular structures in the Protein Data Bank entries and their redundancy has become a major source of structural knowledge of the protein universe. The analysis of structural variability through available redundant structures of a target, called multiple target conformations (MTC), obtained using experimental or modeling methods and under different biological conditions or different sources is one way to explore protein flexibility. This analysis is essential to improve the understanding of various mechanisms associated with protein target function and flexibility. In this study, we explored structural variability of three biological targets by analyzing different MTC sets associated with these targets. To facilitate the study of these MTC sets, we have developed an efficient tool, SA-conf, dedicated to capturing and linking the amino acid and local structure variability and analyzing the target structural variability space. The advantage of SA-conf is that it could be applied to divers sets composed of MTCs available in the PDB obtained using NMR and crystallography or homology models. This tool could also be applied to analyze MTC sets obtained by dynamics approaches. Our results showed that SA-conf tool is effective to quantify the structural variability of a MTC set and to localize the structural variable positions and regions of the target. By selecting adapted MTC subsets and comparing their variability detected by SA-conf, we highlighted different sources of target flexibility such as induced by binding partner, by mutation and intrinsic flexibility. Our results support the interest to mine available structures associated with a target using to offer valuable insight into target flexibility and interaction mechanisms. The SA-conf executable script, with a set of pre-compiled binaries are available at http://www.mti.univ-paris-diderot.fr/recherche/plateformes/logiciels.

Exploring the potential of a structural alphabet-based tool for mining multiple target conformations and target flexibility insight.

Directory of Open Access Journals (Sweden)

Leslie Regad

Full Text Available Protein flexibility is often implied in binding with different partners and is essential for protein function. The growing number of macromolecular structures in the Protein Data Bank entries and their redundancy has become a major source of structural knowledge of the protein universe. The analysis of structural variability through available redundant structures of a target, called multiple target conformations (MTC, obtained using experimental or modeling methods and under different biological conditions or different sources is one way to explore protein flexibility. This analysis is essential to improve the understanding of various mechanisms associated with protein target function and flexibility. In this study, we explored structural variability of three biological targets by analyzing different MTC sets associated with these targets. To facilitate the study of these MTC sets, we have developed an efficient tool, SA-conf, dedicated to capturing and linking the amino acid and local structure variability and analyzing the target structural variability space. The advantage of SA-conf is that it could be applied to divers sets composed of MTCs available in the PDB obtained using NMR and crystallography or homology models. This tool could also be applied to analyze MTC sets obtained by dynamics approaches. Our results showed that SA-conf tool is effective to quantify the structural variability of a MTC set and to localize the structural variable positions and regions of the target. By selecting adapted MTC subsets and comparing their variability detected by SA-conf, we highlighted different sources of target flexibility such as induced by binding partner, by mutation and intrinsic flexibility. Our results support the interest to mine available structures associated with a target using to offer valuable insight into target flexibility and interaction mechanisms. The SA-conf executable script, with a set of pre-compiled binaries are available at

Intrathoracic toxic thyroid nodule causing hyperthyroidism with a multinodular normal functional cervical thyroid gland

International Nuclear Information System (INIS)

Serim, Burcu Dirlik; Korkmaz, Ulku; Can, Unal; Altun, Gulay Durmus

2016-01-01

Radionuclide scintigraphy with I-131 and Tc-99m pertechnetate ( 99 mTc0 4 ) has been widely used in detecting toxic nodules. Intrathoracic goiter usually presents as an anterior mediastinal mass. Mostly the connection between intrathoracic mass and the cervical thyroid gland is clearly and easily identified occurring as a result of inferior extension of thyroid tissue in the neck, which is called as secondary intrathoracic goiter. Completely separated, aberrant or in other words primary intrathoracic goiters arise as a result of abnormal embryologic migration of ectopic thyroid closely associated with aortic sac and descend into the mediastinum. Intrathoracic goiters are generally nontoxic nodules existing with mass effect without causing hyperthyroidism. However, mostly reported cases had enlarged thyroid glands in the neck. This report demonstrates the usefulness of I-131 and 99 mTc0 4 scintigraphy for detecting intrathoracic goiter causing hyperthyroidism with a normal functioned cervical thyroid gland

Solvent extraction technology of 90Mo-sup(99m)Tc system: design and operational considerations

International Nuclear Information System (INIS)

Noronha, O.P.D.; Sewatkar, A.B.

1983-01-01

The design features of 99 Mo-sup(99m)Tc solvent extraction system have been reviewed. An improved semi-automated system has been improvised using the basic equipment of an indigenous unit along with other accessories, and with an added element of radiation protection to handle daily about 300-600 millicurie amounts of reactor-produced very low specific activity 99 Mo. The system has been used routinely for obtaining sup(99m)TcO 4 - - required for diagnostic purposes in nuclear medicine for the last twelve years. The performance characteristics of this unit with respect to yield and purity of 99 TcO 4 - - consistency of the process, the radiation dose to personnel and related health physics aspects have been evaluated. (author)

Cranial MR imaging and cerebral [sup 99m]Tc HM-PAO-SPECT in patients with subacute or chronic severe closed head injury and normal CT examinations

Energy Technology Data Exchange (ETDEWEB)

Prayer, L.; Wimberger, D.; Oder, W.; Kramer, J.; Schindler, E.; Podreka, I.; Imhof, H.

1993-11-01

Eighteen patients in the subacute or chronic state following severe closed head injury with normal cranial CT scans were examined by MR and [sup 99m]Tc HM-PAO SPECT. Correlations were sought between these 2 imaging modalities and the clinical outcome, as defined by the Glasgow Outcome Scale (GOX) score. Both MR and SPECT revealed cerebral damage in all patients examined but structural and functional alterations did not coincide topographically in 64.9% of lesions. Nevertheless, complementary injury patterns suggesting poor recovery were found; cortical contusions and diffuse axonal injury (MR) in conjunction with cortical and thalamic hypoperfusion (SPECT) were noticed in 8 out of 12 patients with unfavorable outcome (GOS = III and IV). The synthesis of MR and SPECT information clearly enhanced the ability both to accurately assess posttraumatic brain damage and to improve patients' outcome prediction. (au) (18 refs.).

Bone scanning with /sup 99m/Tc phosphate to assess condylar hyperplasia. Report of two cases

International Nuclear Information System (INIS)

Matteson, S.R.; Proffit, W.R.; Terry, B.C.; Staab, E.V.; Burkes, E.J. Jr.

1985-01-01

Condylar hyperplasia poses a problem in planning treatment because it is a self-limiting process for some but not all patients. Continued growth creates a progressive deformity that requires condylectomy, whereas an enlarged condyle can be left in place after hyperplastic growth ceases, even if ramus surgery is needed to correct asymmetry. Bone scan with /sup 99m/Tc phosphate can be used to assist in making the differential diagnosis. In the two patients reported here, abnormal metabolic activity revealed by bone scans supported clinical and historical evidence that the condylar hyperplasia was active and required surgical correction, including condylectomy. The two cases demonstrate different approaches to postsurgical orthodontic treatment, depending on the amount of normal growth expected

A functional test of the salivary gland using sup(99m)Tc-pertechnetate

International Nuclear Information System (INIS)

Kiuchi, Sousuke; Oshima, Motoo

1981-01-01

The function of the parotid glands were studied in 45 patients with parotid gland diseases, with the salivary glands affection systemic diseases, and with radiation injury of the parotid glands. As a control, the studies were done on 13 patients with no history of salivary gland disease. The method is consisted of sequential scientigraphy using a gamma scintillation camera and simultaneous recordings of the time-activity curves for the regions over the parotid glands and Stensen's orifices. The examination was commenced immediately after intravenous injection of sup(99m)Tc, and was continued up to 30 minutes. Salivation was stimulated with oral administration of tartaric acid at 20 minutes after injection. According to whether the uptake, concentration and excretion of sup(99m)Tc were diminished or increased, the time-activity curves could be grouped four different patterns. Using this method, a clinician can determine the exact stage of glandular dysfunction. (author)

Model-based crosstalk compensation for simultaneous 99mTc/123I dual-isotope brain SPECT imaging.

Science.gov (United States)

Du, Yong; Tsui, Benjamin M W; Frey, Eric C

2007-09-01

In this work, we developed a model-based method to estimate and compensate for the crosstalk contamination in simultaneous 123I and 99mTc dual isotope brain single photo emission computed tomography imaging. The model-based crosstalk compensation (MBCC) includes detailed modeling of photon interactions inside both the object and the detector system. In the method, scatter in the object is modeled using the effective source scatter estimation technique, including contributions from all the photon emissions. The effects of the collimator-detector response, including the penetration and scatter components due to high-energy 123I photons, are modeled using precalculated tables of Monte Carlo simulated point-source response functions obtained from sources in air at various distances from the face of the collimator. The model-based crosstalk estimation method was combined with iterative reconstruction based compensation to reduce contamination due to crosstalk. The MBCC method was evaluated using Monte Carlo simulated and physical phantom experimentally acquired simultaneous dual-isotope data. Results showed that, for both experimental and simulation studies, the model-based method provided crosstalk estimates that were in good agreement with the true crosstalk. Compensation using MBCC improved image contrast and removed the artifacts for both Monte Carlo simulated and experimentally acquired data. The results were in good agreement with images acquired without any crosstalk contamination.

Sodium metabisulfite: a new reducer agent for direct labelling of immunoglobulins with 99mTc

International Nuclear Information System (INIS)

Zayas, F.; Hernandez, T.; Rodriguez, M.E.; Perera, A.; Hernandez, L.; Valdes, M.

1998-01-01

A method for direct labeling of antibodies with 99mTc is described. Sodium Metabisulfite (SMB) was evaluated as a new reducing agent of disulfide bridges of the IgG molecule. Under selected experimental conditions, radiochemical purities of the label higher than 90.0% were achieved in most of the experiments. On the basis of the obtained yields an empiric equation which describes the system was computed as: Y=93.6+2.1X5 - 1.36X6+0.9X7. The absence of X4 indicated that the purification on Sephadex of the reduced IgG was not relevant to the labeling process. The most important variables were tin ion concentration (X5), the volume of Tin-Tartrate solution (X6) and the incubating time between reduced IgG and Tin-Tartrate solution (X7). A low aggregation and fragmentation of the IgG molecule was obtained when a SMB/IgG molar relation of 750/1 was used. The stability of the 99mTc-IgG was assessed by DTPA, HSA and L-Cysteine challenge studies. An acceptable level of dissociation was observed in presence of DTPA and L-Cysteine, when the Tartrate anion was used. However the transchelation level for HSA was about 80.0 per cent. These preliminary results showed that SMB could be a useful reducing agent for direct labeling of IgG. Further studies are needed to correctly evaluate it. (author)

Particularities in the biodistribution and pharmacokinetic of labeled peptide with 99mTc in regional administration of patient with cervix cancer

International Nuclear Information System (INIS)

Palau San Pedro, A.; Lopez Diaz, A.; Martin Escuela, J. M.; Galvez Perez, E.

2013-01-01

This study had as objective characterize the biodistribution pharmacokinetic and dosimetry of labeled peptide with 9 9mTc in two dose levels, prepared in 2ml, starting from its intratumoral injection in patient with cervix cancer. The protocol selection to use, the correction and calculate methods were analysis object keeping in mind that antecedents of studies of this type didn't exist and that the administration intratumoral can originate new problems not foreseen in conventional intravenous studies. This study carried out mensurations of sensibility that should be corrected in a particular way. A careful protocol of acquisition was designed able to detect the behavior of the radio-peptide in the time, with a serial gathering of samples of blood and urine until the 24 hours, as well as images of the whole body up to 48h. For the quantification of the images they were necessary also the classic corrections of background and of overlapping of structures. The labeled peptide with 9 9mTc administered for intralesional way, like it was of waiting it presented a very high reception tumoral, being this maxim in the first images, however the product was absorbed quickly in blood, reaching its maximum levels in most of the patients as much in serum as in total blood, in the first 5-15 minutes of having administered. (Author)

Obtaining a metastasis model in vivo for the evaluation of the radiopharmaceuticals sensitivity labeled with {sup 99m}Tc; Obtencion de un modelo de metastasis in vivo para la evaluacion de la sensibilidad de radiofarmacos marcados con {sup 99m}Tc

Energy Technology Data Exchange (ETDEWEB)

Gonzalez A, V. M.

2015-07-01

Nuclear medicine currently has a wide range of techniques that support the diagnosis of various diseases, including cancer that prevails as the most important. In the present research work was proposed to develop a model that would study the process known as metastasis, because this process is vital because most of the deaths in patients with some form of cancer are caused by metastasis. The objective was to obtain an in vivo model of metastasis induced with AR42J cells for studying the radiopharmaceuticals sensitivity labeled with {sup 99m}Tc. To achieve the objective proposed a study model in which it could make a real time evaluation of some radiopharmaceuticals with reported efficiency was development, in order to determine their sensitivity in similar conditions to the metastasis process. This required a mouse model that was used to observe a similar process to metastasis, inducing cells of the AR42J cell line, since these cells have good proliferation and have molecular targets for a minimum of 3 standardized radiopharmaceuticals. Was elected radionuclide {sup 99m}Tc, because of its low emission of radiation into the tissues, besides having a half life of 6 hours and provides a good visualization of anatomical structures. On the other hand the stable expression of green fluorescent protein in tumor cells appears to be a suitable tool for the detection of cancer development in early stages and the formation of in vivo micro metastases, so two fluorescence tests were performed and other by electrophoresis. The results showed that both study models can be carried out without increasing complexity and meeting the expectations expected for which they were designed. (Author)

Three-dimensional cytomorphology in fine needle aspiration biopsy of medullary thyroid carcinoma.

Science.gov (United States)

Chang, T C; Lai, S M; Wen, C Y; Hsiao, Y L; Huang, S H

2001-01-01

To elucidate three-dimensional (3-D) cytomorphology in fine needle aspiration biopsy (FNAB) of medullary thyroid carcinoma (MTC). ENAB was performed on tumors from five patients with MTC. The aspirate was stained and observed under a light microscope (LM). The aspirate was also fixed, dehydrated, critical point dried, spattered with gold ions and observed with a scanning electron microscope (SEM). For transmission electron microscopy (TEM), the specimen was fixed, dehydrated, embedded in an Epon mixture, cut with an ultramicrotome, mounted on copper grids, electron doubly stained with uranium acetate and lead citrate, and observed with TEM. Findings under SEM were correlated with those under LM and TEM. Under SEM, 3-D cytomorphology of MTC displayed a disorganized cellular arrangement with indistinct cell borders in three cases. The cell surface was uneven and had granular protrusions that corresponded to secretory granules observed under TEM. In one case with multiple endocrine neoplasia type IIB, there were abundant granules on the cell surface. In one case of sporadic MTC with multinucleated tumor giant cells and small cells, granular protrusions also were noted on the cell surface. Granular protrusion was a characteristic finding in FNAB of MTC tinder SEM and might be helpful in the differential diagnosis.

Optimizing labeling conditions for cysteine-based peptides with {sup 99m}Tc

Energy Technology Data Exchange (ETDEWEB)

Sabahnoo, Hamideh; Hosseinimehr, Seyed Jalal, E-mail: sjhosseinim@yahoo.com [Department of Radiopharmacy, Faculty of Pharmacy, Pharmaceutical Sciences Research Center, Mazandaran University of Medical Sciences, Sari (Iran, Islamic Republic of)

2016-07-01

Radiolabelled peptides have attracted a great deal of attention due to their wide applicability in the development of target-specific radiopharmaceuticals. They can easily be used in diagnostic imaging as carriers for the delivery of radionuclides to tumors as well as for therapy. Previous investigations revealed that technetium(V) could form stable complexes with peptide-based ligands of N{sub 3}S type such as Cys-Gly-Gly-Gly. Herein, a targeting HER-2 receptor peptide was labeled with technetium-{sup 99m} ({sup 99m}Tc) with two different types of tetrapeptide-based ligands, Cys-Gly-Gly-Gly and Cys-Ser-Ser-Ser. The effect of experimental parameters in the labeling procedure such as type of buffer solutions, pH of media, and type of exchange ligands were optimized toward obtaining maximum labeling yield. The optimum labeling conditions were different for two peptides. Shelf life of both labeled peptides was determined by analytical reversed-phase high-performance liquid chromatography (RP-HPLC) and thin layer chromatography (TLC) that showed radiochemical yield up to 95% even after 4 h. (author)

Studies of post-elution concentration of {sup 99m}-Tc eluted from a gel type chromatographic generator

Energy Technology Data Exchange (ETDEWEB)

Suzuki, Katia N.; Osso Junior, Joao Alberto [Instituto de Pesquisas Energeticas e Nucleares (IPEN/CNEN-SP), Sao Paulo, SP (Brazil)]. E-mail: norisuzuki6@yahoo.com.br; jaosso@ipen.br

2007-07-01

The radiopharmaceuticals most used in Diagnostic Nuclear Medicine are those labeled with the metastable technetium ({sup 99m}Tc) due to its ideal physical properties of decay (t{sub 1/2} 6.01 h, E{gamma} 140 keV), low cost and availability facilitated through the commercial generator {sup 99}Mo /{sup 99m}Tc. This radionuclide is formed by the {beta}{sup -} decay of {sup 99}Mo adsorbed on an alumina column of the generator and collected in the form of sodium pertechnetate (Na{sup 99m}TcO{sub 4}) by elution with saline solution (0.9%). The Radiopharmacy Center (CR) of the IPEN-CNEN/SP developed a gel type chromatographic generator of MoZr with {sup 99}Mo produced by {sup 98}Mo(n, {gamma}){sup 99}Mo reaction that occurs in IEA-R1 Nuclear Reactor. The gel is composed of zirconium molybdate with elution volume of 12 ml with an activity of 11100 MBq (300 mCi) producing a radioactive concentration of 925 MBq (34 mCi) / ml. The fission generator gives a higher radioactive concentration around 1850 MBq (69 mCi) / ml. The aim of this work is to study a system of post-elution concentration using ion exchange cartridges in tandem (cation - anion) for the attainment of a high enough radioactive concentration to meet the demand of market, with a proved quality. This system of concentration will be made based in the technique of solid phase extraction (SPE) using commercial cartridges of extraction, which contains the solid phase and eluent saline solution (0.9%). As the eluent results of this system used in the gel generator of MoZr will be compared with the fission generator currently produced by IPEN-CNEN/SP. (author)

Evaluation of {sup 99}Mo/{sup 99m}Tc generator columns after irradiation with different absorbed doses

Energy Technology Data Exchange (ETDEWEB)

Fukumori, Neuza T.O.; Mengatti, Jair; Matsuda, Margareth M.N., E-mail: ntfukumo@ipen.br [Instituto de Pesquisas Energeticas e Nucleares (IPEN/CNE-SP), Sao Paulo, SP (Brazil)

2017-07-01

The {sup 99}Mo/{sup 99m}Tc generator is widely used in nuclear medicine and it consists of a glass column containing Teflon® strips and alumina in which {sup 99}Mo produced by {sup 235}U fission is adsorbed. The {sup 99}mTcO4- eluate shall meet the sterile and pyrogen free conditions for injectable radiopharmaceuticals as determined by the Good Manufacturing Practices. The purpose of this study was to evaluate the feasibility of using gamma radiation in the sterilization of the {sup 99}Mo/{sup 99m}Tc generator column and the influence on the elution efficiency. Alumina-containing columns were irradiated with 10, 15, 25 and 50 kGy absorbed doses. Alumina samples and control (non-irradiated) were submitted to X-ray diffraction and the combined use of scanning electron microscopy and elemental analysis. Teflon® samples were evaluated by thermogravimetry (TGA) and differential scanning calorimetry (DSC). X-ray diffractograms and micrographies with elemental analysis showed no significant changes in the crystalline structure of the alumina because it was stable α-Al{sub 2}O{sub 3}. TGA demonstrated that higher doses showed changes in lower temperatures and times than the control material. For DSC the higher the absorbed dose, the greater the polymer chain breakage and crosslinking in the material. The generator system without radioactivity was set up with the irradiated columns and the eluates demonstrated to be sterile and pyrogen free. The effects of different absorbed doses on the generator column, although some reported changes in the materials, demonstrated that the sterilization of the columns by irradiation with gamma rays as an alternative to wet heat sterilization is feasible from a technical and financial point of view. (author)

Radiolabeling of rituximab with {sup 188}Re and {sup 99m}Tc using the tricarbonyl technology

Energy Technology Data Exchange (ETDEWEB)

Dias, Carla Roberta [Instituto de Pesquisas Energeticas e Nucleares, Av. Professor Lineu Prestes 2242, 05508-000 Sao Paulo (Brazil); Jeger, Simone [Center for Radiopharmaceutical Sciences ETH-PSI-USZ, Paul Scherrer Institute, 5232 Villigen-PSI (Switzerland); Osso, Joao Alberto [Instituto de Pesquisas Energeticas e Nucleares, Av. Professor Lineu Prestes 2242, 05508-000 Sao Paulo (Brazil); Mueller, Cristina; De Pasquale, Christine; Hohn, Alexander; Waibel, Robert [Center for Radiopharmaceutical Sciences ETH-PSI-USZ, Paul Scherrer Institute, 5232 Villigen-PSI (Switzerland); Schibli, Roger, E-mail: roger.schibli@psi.c [Center for Radiopharmaceutical Sciences ETH-PSI-USZ, Paul Scherrer Institute, 5232 Villigen-PSI (Switzerland); Department of Chemistry and Applied Biosciences of the ETH, 8093 Zurich (Switzerland)

2011-01-15

Introduction: The most successful clinical studies of immunotherapy in patients with non-Hodgkin's lymphoma (NHL) use the antibody rituximab (RTX) targeting CD20{sup +} B-cell tumors. Rituximab radiolabeled with {beta}{sup -} emitters could potentiate the therapeutic efficacy of the antibody by virtue of the particle radiation. Here, we report on a direct radiolabeling approach of rituximab with the {sup 99m}Tc- and {sup 188}Re-tricarbonyl core (IsoLink technology). Methods: The native format of the antibody (RTX{sub wt}) as well as a reduced form (RTX{sub red}) was labeled with {sup 99m}Tc/{sup 188}Re(CO){sub 3}. The partial reduction of the disulfide bonds to produce free sulfhydryl groups (-SH) was achieved with 2-mercaptoethanol. Radiolabeling efficiency, in vitro human plasma stability as well as transchelation toward cysteine and histidine was investigated. The immunoreactivity and binding affinity were determined on Ramos and/or Raji cells expressing CD20. Biodistribution was performed in mice bearing subcutaneous Ramos lymphoma xenografts. Results: The radiolabeling efficiency and kinetics of RTX{sub red} were superior to that of RTX{sub wt} ({sup 99m}Tc: 98% after 3 h for RTX{sub red} vs. 70% after 24 h for RTX{sub wt}). {sup 99m}Tc(CO){sub 3}-RTX{sub red} was used without purification for in vitro and in vivo studies whereas {sup 188}Re(CO){sub 3}-RTX{sub red} was purified to eliminate free {sup 188}Re-precursor. Both radioimmunoconjugates were stable in human plasma for 24 h at 37{sup o}C. In contrast, displacement experiments with excess cysteine/histidine showed significant transchelation in the case of {sup 99m}Tc(CO){sub 3}-RTX{sub red} but not with pre-purified {sup 188}Re(CO){sub 3}-RTX{sub red}. Both conjugates revealed high binding affinity to the CD20 antigen (K{sub d}=5-6 nM). Tumor uptake of {sup 188}Re(CO){sub 3}-RTX{sub red} was 2.5 %ID/g and 0.8 %ID/g for {sup 99m}Tc(CO){sub 3}-RTX{sub red} 48 h after injection. The values for other

Cardiac function studies

International Nuclear Information System (INIS)

Horn, H.J.

1986-01-01

A total of 27 patients were subjected tointramyocardial sequential scintiscanning (first pass) using 99m-Tc human serum albumin. A refined method is described that is suitable to analyse clinically relevant parameters like blood volume, cardiac output, ejection fraction, stroke volume, enddiastolic and endsystolic volumes as well as pulmonal transition time and uses a complete camaracomputer system adapted to the requirements of a routine procedure. Unless there is special hardware available, the method does not yet appear mature enough to be put into general practice. Its importance recently appeared in a new light due to the advent of particularly shortlived isotopes. For the time being, however, ECG-triggered equilibrium studies are to be preferred for cardiac function tests. (TRV) [de

Perfusion scintigraphy of the hand with sup(99m)Tc labelled microspheres - an alternative to angiography in the diagnosis of peripheral perfusion disturbances

Energy Technology Data Exchange (ETDEWEB)

Karnahl, H M; Hedde, J P [Allgemeine Ortskrankenkasse Koeln (Germany, F.R.). Strahleninstitut

1979-12-01

sup(99m)Tc labelled microspheres were injected in the A. brachialis in addition to angiography of the hand in 15 patients. The hereby obtained results show good correlation between angiography and scintigraphy. The completely normal perfusion scintigram of the hand allows to dispense with angiography. The pathological scan, however, requires angiography. Perfusion scintigraphy of the hand seems to be most useful in the follow-up of therapeutic effects in perfusion disturbances.

Simulation of a gamma-camera for activity measurement of {sup 99m}Tc using the Monte Carlo Gate code; Simulação de uma gama-câmara para medidas de atividade de {sup 99m}Tc com o código de Monte Carlo Gate

Energy Technology Data Exchange (ETDEWEB)

Barrientos, C.P. Castro; Souza-Santos, D. [Instituto de Radioproteção e Dosimetria (IRD/CNEN-RJ), Rio de Janeiro, RJ (Brazil); Mação Junior, J.L.; Wunder, R.S.; Knust, I.C., E-mail: car_pcb@aluno.ird.gov.br [Hospital Naval Marcílio Dias, Rio de Janeiro, RJ (Brazil)

2017-07-01

Brazil has a growing demand for nuclear medicine services (NMS), and radiopharmaceuticals supplied by the National Nuclear Energy Commission (CNEN) provide approximately two million nuclear medicine (NM) procedures per year. Among these radiopharmaceuticals, one of the most used is {sup 99m}Tc. The manipulation of unsealed radioactive sources presents a risk of incorporation. Workers who handle radiopharmaceuticals in NM procedures should be subject to an internal individual monitoring program to optimize their practices as well as to ensure that dose limits are not exceeded. This program may require measuring the activity of incorporated radionuclides, done in a whole body counter. This measurement may prove impracticable due to the absence of dedicated systems, available to all workers in a country. One solution to this problem would be to perform the measurement of the incorporated activity using the Gamma camera of the NMS in which the occupationally exposed individual (IOE) works. The objective of this work is to simulate with the Monte Carlo method a Gamma camera, with the code Gate, validating the results for the {sup 99m}Tc through measurements performed in an NMS. Measurements of counts were taken around the 140 keV main peak, with and without the collimator, that were correlated with the source activity. The validation shows good agreement between the simulation and the experimental data, with a difference of about 3% for the simulation without the collimator and about 2% for the simulation with the collimator. (author)

ESTIMATION OF PARAMETERS AND RELIABILITY FUNCTION OF EXPONENTIATED EXPONENTIAL DISTRIBUTION: BAYESIAN APPROACH UNDER GENERAL ENTROPY LOSS FUNCTION

Directory of Open Access Journals (Sweden)

Sanjay Kumar Singh

2011-06-01

Full Text Available In this Paper we propose Bayes estimators of the parameters of Exponentiated Exponential distribution and Reliability functions under General Entropy loss function for Type II censored sample. The proposed estimators have been compared with the corresponding Bayes estimators obtained under Squared Error loss function and maximum likelihood estimators for their simulated risks (average loss over sample space.

Comparison of the chemical behaviour of humanized ACMS VS. Human IGG radiolabeled with 99mTc

International Nuclear Information System (INIS)

Rivero Santamaria, Alejandro; Zayas Crespo, Francisco; Mesa Duennas, Niurka; Castillo Vitloch, Adolfo J.

2003-01-01

The purpose of this work is to compare the chemical behaviour of humanized AcMs vs. human IgG radiolabeled with 99 mTc. to this end, 3 immunoglobulins were analyzed, the IgG (human), the humanized monoclonal antibody R3 (Acm-R3h) and the humanized monoclonal antibody T1. The results obtained reveal slight differences as regards the behaviour of theses immunoglobulins before the labelling with 99T c, which shows differences in the chemical behaviour of these proteins. Although in theory the modifications that are made to the AcMs in order to humanize them must not affect their chemical behaviour, the obtained data indicate that the conditions for their radiolabelling should not be extrapolated from other proteins; on the contrary, particular procedures should be elaborated for each AcM-h

Residual stresses and strength of multilayer tape cast solid oxide fuel and electrolysis half-cells

DEFF Research Database (Denmark)

Charlas, Benoit; Frandsen, Henrik Lund; Brodersen, Karen

2015-01-01

those with 3 layers (MTC3: without barrier layer). The bending strength of MTC3 and MTC4 under various loading orientations (electrolyte on the tensile or compressive side of the loading) is compared. The analysis, by taking residual stresses into account, shows that the strength of the half...... coefficient (TEC) mismatch between the layers, cumulated from high temperature, induces significant residual stresses in the half-cells. Furthermore, it has been observed that MTC half-cells with 4 layers (MTC4: support, fuel electrode, electrolyte and barrier layer) are sometimes more fragile to handle than...... stresses, especially in the outer barrier-layer, possible changes to the layer properties are discussed and some optimization guidelines proposed....

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

Analysis of the variation of the activity of a "9"9"mTc sample after dilution with saline solution

International Nuclear Information System (INIS)

Kuahara, L.T.; Correa, E.L.; Potiens, M.P.A.

2016-01-01

The activity meter is essential equipment in nuclear medicine services.To ensure its good operation and know the factors which may influence its readings is vital for the activity administered to the patient be correct. Many factors may influence the activity meter accuracy, such as the type of container, geometry, and radioactive material volume. The aim of this study was to analyze the measurements variations in 0.5 ml and 1.0 ml of "9"9"mTc pure and diluted in 2.5 ml of saline solution, in containers used in nuclear medicine. Variations of up to 4 % in measured values were found. (author)

Development of lyophilized kit of Tin-Glucoheptonate for in vitro labeling of leucocytes with {sup 99m}Tc; Desenvolvimento de reagente liofilizado de glucoheptonato-estanho para marcacao de leucocitos com Tecnecio-99m in vitro

Energy Technology Data Exchange (ETDEWEB)

Nascimento, Rosemeire Fagundes

2007-07-01

The study and localization of inflammatory and infection process in Nuclear Medicine represents a relevant tool in diagnostic procedures. In same cases, the diagnostic is easy and based on anamnesis and clinical observation; in other cases, the patients are asymptomatic or present non specific symptoms that difficult the diagnostic. The early diagnostic of inflammatory or infectious process allow the early introduction of therapy and prevents complications. Farther, the differentiation between inflammation and infection is of extreme importance as well as the localization of the focus. The use of labeled leucocytes, studied and applied in much pathologies, is the method of choice for the visualization of inflammation and infection. The scintigraphy using labeled leucocytes was introduced at 1976 by McAffe and Thakur and since of this is used in the diagnostic of different pathologies related to leucocyte infiltration like intestinal inflammatory disease, bone or prosthetic-vascular infections. The in vitro labeling of leucocytes with {sup 111}In was performed using oxime or tropolone as ligand and with {sup 99m}Tc using hexamethylpropylene amine oxime (HMPAO) as ligand, resulting in a lipophilic complex. The {sup 99m}Tc-HMPAG complex was preferably employed in many indications and countries do to the ideal physical properties of {sup 99m}Tc that results in low dose to the patient. However, the labeling employing the HMPAO complex results in some disadvantages like the low stability of the complex, and some requirements related to the {sup 99m}Tc elution (like the time pos elution), beyond the high cost of the compound that is imported. The aim of this work was the development of a tin-glucoheptonate lyophilized kit for in vitro leucocytes labeling with {sup 99m}Tc using the pre-stannization method. The optimization of the labeling technique was developed using leucocytes isolated from total blood and employing different volumes of the tinglucoheptonate reagent and

Thermoluminescence under an exponential heating function: I. Theory

International Nuclear Information System (INIS)

Kitis, G; Chen, R; Pagonis, V; Carinou, E; Kamenopoulou, V

2006-01-01

Constant temperature hot gas readers are widely employed in thermoluminescence dosimetry. In such readers the sample is heated according to an exponential heating function. The single glow-peak shape derived under this heating condition is not described by the TL kinetics equation corresponding to a linear heating rate. In the present work TL kinetics expressions, for first and general order kinetics, describing single glow-peak shapes under an exponential heating function are derived. All expressions were modified from their original form of I(n 0 , E, s, b, T) into I(I m , E, T m , b, T) in order to become more efficient for glow-curve deconvolution analysis. The efficiency of all algorithms was extensively tested using synthetic glow-peaks

Cooperative study with sup(99m)Tc diisopropil-IDA on biliary tract diseases

International Nuclear Information System (INIS)

Mitta, A.E.A.; Mollerach, F; Almeida, C.A.

1982-01-01

The results of a cooperative study on the investigation of the biliary tract with sup(99m)Tc diisopropyl-IDA are presented. 15 normal volunteers and 75 patients with acute cholecystitis (AC), chronic cholecystitis (CC), hepatocellular jaundice (HCJ), incomplete extrahepatic biliary obstruction (IEBO) and complete extrahepatic biliary obstruction (CEBO) were studied. The biological behaviour of the radiopharmaceutical in the two groups was determined through the measurement of the uptake times and of the times of arrival in the hepatic parenchyma, in the intra and extrahepatic bile ducts, in the gallbladder, in the duodenum and in the kidneys. The pathophysiologic features found in the AC, CC, HCJ, IEBO and CEBO are described. It is concluded that the procedure has a selective indication in the AC, that its value is limited in the CC, and that in jaundice, except in very special situations, the method gives very little information of clinic value. The possibility of performing cooperative scientific studies between Latin-American Departments, increasing their efficiency, is emphasized. (author) [es

Dose to the stomach wall from injected /sup 99m/Tc pertechnetate

International Nuclear Information System (INIS)

Ford, M.R.; Deus, S.F.; Snyder, W.S.

1976-01-01

In estimating the radiation dose to the gastrointestinal tract (GIT) it has been assumed generally that the measured activity in the tract, i.e., in the walls, is present in the contents. This assumption has been necessary because absorbed fractions for photons were available only for the source in the contents. During the past year and a half, however, absorbed fractions, or specific absorbed fractions, have been estimated for photon emitters in the walls. In the work presented here new values are applied to estimate dose to the walls of the GIT from administration of /sup 99m/Tc pertechnetate. The dose to the stomach wall from photons is found to be less than the dose from nonpenetrating radiation, assuming complete absorption of energy. Thus, a correct estimation of average dose to the wall requires use of absorbed fractions of energy for electrons as well as for photons. The problem is discussed and values of absorbed fractions for electrons are given which are based on a uniform distribution of the activity. However, a final resolution of the problem will require further biological data on the fraction of activity in the wall and the fraction in the contents

Quantitative hepatosplenic scintiscanning. Experimental and clinical studies to determine the contents of radioactivity in liver and spleen following administration of 99mTc sulfur colloid

International Nuclear Information System (INIS)

Feuchtinger, T.

1983-01-01

Hepatosplenic scintiscans were obtained from 78 patients following administration of 99mTc sulfur colloid using a double-head scanner and subjected to quantitative analysis. It was the aim of the study to assess the practicability of quantitative scintiscanning of liver and spleen, to define the range of generally acceptable, normal values for the concentration of 99mTc sulfur colloid in liver and spleen as well as to evaluate the clinical relevance of this method. The following values were determined to be normal: 4.7±1.5 for the liver: Spleen ratio; 31±3% for the proportion of the left hepatic lobe in total liver concentration; 68.7±5.4% and 17.4±3.6% for the active contents of liver and spleen, respectively. Quantitative scintiscanning constitutes a very sensitive method to detect transformation processes in the liver that are associated with a decreased liver: Spleen ratio and an increased ratio between the left hepatic lobe and the total organ. The method is unsuitable to assess pathological accumulation of the tracer substances. The question as to whether the use of the more time-consuming procedure of quantitative scintiscanning is justified by the additional diagnostic information gained remains to be investigated in further studies. (TRV) [de

Gamma-ray impurities of {sup 111}In, {sup 201}Tl, {sup 177}Lu and {sup 99m}Tc determined by means of a HPGE spectrometer

Energy Technology Data Exchange (ETDEWEB)

Koskinas, Marina F.; Almeida, Jamille da Silveira; Moreira, Denise Simões; Semmler, Renato; Dias, Mauro da Silva, E-mail: koskinas@ipen.br, E-mail: jamillealmeida@gmail.com, E-mail: denise.moreira@ipen.br, E-mail: rsemmler@ipen.br, E-mail: msdias@ipen.br [Instituto de Pesquisas Energeticas e Nucleares (IPEN/CNEN-SP), Sao Paulo, SP (Brazil)

2017-11-01

This work aims to present the radioactive impurities gamma rays emitters detected in some radiopharmaceuticals widely applied to diagnosis and therapy purposes, supplied to nuclear medicine services in Brazil by the Radiopharmaceutical Center(CR) of Nuclear and Energy Research Institute, IPEN, in São Paulo. The analysis was undertaken by means of an HPGe gamma spectrometer. The radiopharmaceuticals analyzed were: {sup 111}In, {sup 201}Tl, {sup 177}Lu and {sup 99m}Tc. (author)

The accumulation and retention of {sup 95m}Tc by the Norway lobster, Nephrops norvegicus L

Energy Technology Data Exchange (ETDEWEB)

Swift, D. E-mail: d.j.swift@cefas.co.uk

2001-07-01

Laboratory experiments were carried out to study bioaccumulation and determine a concentration factor (CF) for technetium ({sup 95m}Tc) in the homarid crustacean Nephrops norvegicus L. The steady state CF for accumulation from seawater was estimated to be about 2000 and the biological half-time was about 50 days. The highest tissue Tc concentrations were found in the green gland and the digestive gland. Depuration following accumulation from water was slow with a half-time of about 165 days. Tc accumulation from labelled food followed a biphasic model with one compartment containing about 94 percent of the ingested activity and with a half-time of about 1 day and the second compartment containing about 6 percent of the ingested activity with a half-time of about 56 days. Most retained activity was found in the digestive gland.

Wave Functions for Time-Dependent Dirac Equation under GUP

Science.gov (United States)

Zhang, Meng-Yao; Long, Chao-Yun; Long, Zheng-Wen

2018-04-01

In this work, the time-dependent Dirac equation is investigated under generalized uncertainty principle (GUP) framework. It is possible to construct the exact solutions of Dirac equation when the time-dependent potentials satisfied the proper conditions. In (1+1) dimensions, the analytical wave functions of the Dirac equation under GUP have been obtained for the two kinds time-dependent potentials. Supported by the National Natural Science Foundation of China under Grant No. 11565009

Labelling of m-trimethyl silylphenyl-ethylidene-1, i-bisphosphonate with /sup 99m/Tc and its evaluation as an imaging agent

International Nuclear Information System (INIS)

Sajid, K.M.; Mahmood, R.

2012-01-01

Technetium-99m labeled phosphates and phosphonates have since long been in use for bone imaging to diagnose bone infection, bone metastasis and bone fracture. /sup 131/ I -labeled bisphosphonates have also been prepared for targeted radiotherapy of bone metastasis. Although animal experiments show good accumulation of bisphosphonates in bone. The agent has never been tried in humans because of high gamma and beta energy. The agent must first be tested in humans using a relatively safe radioisotope. Technitium-99m (/sup 99m/Tc) a radioisotope with relatively low gamma energy 99m and short half-life can serve as a good label. Whether /sup 99m/Tc-labeled bisphosphonates can be used as good imaging agents is another aspect that needs further investigation. A study was therefore, conducted to label m-trimethyl silylphenyl)-ethylidene-1, 1-bisphosphonate with /sup 99m/Tc and standardize the labeling procedure. The labeling procedure - involved reduction of technetium (TcO/sub 4/) with stannous chloride followed by chelation of technetium with bisphosphonates. Radiochemical purity was checked by paper chromatography. Pyrogenicity was checked by administration of the labeled compound into rabbits. The stability of the compound was determined by noting the radiochemical binding at several intervals of half an hour after preparation. Biodistribution of the agent was studied by injecting the labeled compound into rabbits. The results showed that the compound could be labeled with /sup 99m/Tc without any difficulty. The ease of binding was excellent. There was more than 95% binding of technetium with the compound and the labelled compound was reasonably stable for 5 hours after labeling. The rectal temperature remained stable during this period, which showed that the animal accepted the compound and there were no pyrogenic reactions. Biodistribution studies on rabbit showed that accumulation of agent was poor in bones and the labeled compound remains in blood even after 4

Sheared Layers in the Continental Crust: Nonlinear and Linearized inversion for Ps receiver functions

Science.gov (United States)

Park, J. J.

2017-12-01

Sheared Layers in the Continental Crust: Nonlinear and Linearized inversion for Ps receiver functions Jeffrey Park, Yale University The interpretation of seismic receiver functions (RFs) in terms of isotropic and anisotropic layered structure can be complex. The relationship between structure and body-wave scattering is nonlinear. The anisotropy can involve more parameters than the observations can readily constrain. Finally, reflectivity-predicted layer reverberations are often not prominent in data, so that nonlinear waveform inversion can search in vain to match ghost signals. Multiple-taper correlation (MTC) receiver functions have uncertainties in the frequency domain that follow Gaussian statistics [Park and Levin, 2016a], so grid-searches for the best-fitting collections of interfaces can be performed rapidly to minimize weighted misfit variance. Tests for layer-reverberations can be performed in the frequency domain without reflectivity calculations, allowing flexible modelling of weak, but nonzero, reverberations. Park and Levin [2016b] linearized the hybridization of P and S body waves in an anisotropic layer to predict first-order Ps conversion amplitudes at crust and mantle interfaces. In an anisotropic layer, the P wave acquires small SV and SH components. To ensure continuity of displacement and traction at the top and bottom boundaries of the layer, shear waves are generated. Assuming hexagonal symmetry with an arbitrary symmetry axis, theory confirms the empirical stacking trick of phase-shifting transverse RFs by 90 degrees in back-azimuth [Shiomi and Park, 2008; Schulte-Pelkum and Mahan, 2014] to enhance 2-lobed and 4-lobed harmonic variation. Ps scattering is generated by sharp interfaces, so that RFs resemble the first derivative of the model. MTC RFs in the frequency domain can be manipulated to obtain a first-order reconstruction of the layered anisotropy, under the above modeling constraints and neglecting reverberations. Examples from long

Accumulation of sup(95m)Tc from sea water by juvenile lobsters (Homarus gammarus L. )

Energy Technology Data Exchange (ETDEWEB)

Swift, D.J. (Ministry of Agriculture, Fisheries and Food, Lowestoft (UK). Directorate of Fisheries Research)

1985-01-01

The uptake and retention of technetium from sea water by juvenile lobsters, and the effects of moulting on these processes, has been studied using sup(95m)Tc as a tracer. Accumulation was rapid with whole body concentration factors of over 2000 being measured in some lobsters. Uptake was highest immediately before a moult; post-moult there was a fall in accumulation. No simple mathematical equation for technetium accumulation with time was found. The technetium concentration in the moulted exoskeleton increased with time of exposure of the lobsters but never exceeded 2% of the whole body value. The highest percentage of the whole body activity was found in the digestive gland; the green gland had the highest concentration factor. Technetium excretion, following 64 d of accumulation, could be expressed as an exponential rate of loss. The biological half-time was calculated as 53 d. Moulted exoskeletons from these lobsters contained approximately 0.6% of the day zero whole body activity.

Managed Multi-strata Tree + Crop Systems: An Agroecological Marvel

Directory of Open Access Journals (Sweden)

P. K. Ramachandran Nair

2017-12-01

Full Text Available Today, when the emphasis on single-species production systems that is cardinal to agricultural and forestry programs the world over has resulted in serious ecosystem imbalances, the virtues of the time-tested practice of growing different species together as in managed Multi-strata Tree + Crop (MTC systems deserve serious attention. The coconut-palm-based multispecies systems in tropical homegardens and shaded perennial systems are just two such systems. A fundamental ecological principle of these systems is niche complementarity, which implies that systems that are structurally and functionally more complex than crop- or tree monocultures result in greater efficiency of resource (nutrients, light, and water capture and utilization. Others include spatial and temporal heterogeneity, perennialism, and structural and functional diversity. Unexplored or under-exploited areas of benefits of MTC systems include their ecosystem services such as carbon storage, climate regulation, and biodiversity conservation. These multispecies integrated systems indeed represent an agroecological marvel, the principles of which could be utilized in the design of sustainable as well as productive agroecosystems. Environmental and ecological specificity of MTC systems, however, is a unique feature that restricts their comparison with other land-use systems and extrapolation of the management features used in one location to another.

Harvard--MIT research program in short-lived radiopharmaceuticals. Progress report, September 1, 1977--April 30, 1978. [/sup 99m/Tc, positron-emitting radionuclides

Energy Technology Data Exchange (ETDEWEB)

Adelstein, S.J.; Brownell, G.L.

1978-05-01

Progress is reported on the following studies: chemistry studies designed to achieve a more complete understanding of the fundamental chemistry of technetium in order to facilitate the design of future radiopharmaceuticals incorporating the radionuclide /sup 99m/Tc; the development of new radiopharmaceuticals intended to improve image quality and lower radiation doses by the use of short-lived radionuclides and disease-specific agents; the development of short-lived positron-emitting radionuclides which offer advantages in transverse section imaging of regional physiological processes; and studies of the toxic effects of particulate radiation.

In vitro cytotoxicity testing of Ubiquicidin 29-41-{sup 99m}Tc

Energy Technology Data Exchange (ETDEWEB)

Ocampo, Ivette Z.; Okazaki, Kayo; Dias, Luis Alberto Pereira; Higa, Olga Z.; Silva, Fabiana M. da; Vieira, Daniel P., E-mail: dpvieira@ipen.br [Instituto de Pesquisas Energeticas e Nucleares (IPEN/CNEN-SP), Sao Paulo, SP (Brazil); Passos, Priscila; Esteves-Pedro, Natalia M., E-mail: fabiana@biosintesis.com.br [Laboratorio Biosintesis Ltda, Sao Paulo, SP (Brazil)

2015-07-01

The work carried out cytotoxicity tests using a radiopharmaceutical compound produced at IPEN/CNEN-SP to certify its safety through in vitro cytotoxicity tests. Since 2009, the Brazilian regulatory agency (ANVISA) requires that such tests have to be carried out following good laboratory practices (GLP) and in according to the OECD (Organisation for Economic Co-operation and Development) guidelines in order to certify its safety for medical use. Those guidelines comprises series of technical recommendations performed to assure quality of experiments. The study chose Ubiquicidin 29-41, an antimicrobial peptide used to discriminate bacterial infection foci from inflammatory sites. Amounts of UBI{sub 29-41} were conjugated or not to {sup 99m}Tc and diluted to equivalent concentrations of 10, 100 and 1000% of the maximum dose (or activity) administered in adults. Possible cytotoxic effects were evaluated in comparison to untreated controls as well as positive and negative damage controls. Both full (radioactive) radiopharmaceuticals, as their precursors (only molecules without conjugation to isotopes) showed no significant cytotoxic effect (cytotoxicity ≤ 10%). The study was conducted for the first time in the country comprising preclinical testing of this radiopharmaceutical in accordance with internationally accepted quality parameters, ensuring the safety of its use and enabling inclusion in the pharmaceutical regulatory agenda. (author)

{sup 99m}Tc radiolabeling and biodistribution study of scorpionfish (Scorpaena plumieri) venom in Swiss mice

Energy Technology Data Exchange (ETDEWEB)

Soprani, Juliana; Pujatti, Priscilla B.; Santos, Raquel G. dos [Centro de Desenvolvimento da Tecnologia Nuclear(CDTN/CNEN-MG), Belo Horizonte, MG (Brazil). Lab. de Radiobiologia]. E-mail: falejs@yahoo.com.br; priscillapujatti@yahoo.com.br; santosr@cdtn.br; Figueiredo, Suely G. de [Universidade Federal do Espirito Santo (UFES), Vitoria, ES (Brazil). Depto. de Ciencias Fisiologicas]. E-mail: suelygf@gmail.com; Simal, Carlos [Universidade Federal de Minas Gerais (UFMG), Belo Horizonte, MG (Brazil). Faculdade de Medicina]. E-mail: csimal@brfree.com.br

2007-07-01

The use of radiotracers in research of animal venom has been scarce, although it allows an excellent approach to follow the process of biodistribution and kinetics of toxins, and tissue distribution studies are very important for clinical use. Our group has demonstrated that Scorpaena plumieri venom (SP) possess high antitumoral activity and can be a source of template molecules for the development of antitumoral drugs. The purpose of this study was to radiolabel SP with 99mTc and investigate its biodistribution profile. High labeling yield was obtained and the results suggest that [99mTc]SP can be an useful tool for in vivo studies. The analysis indicated that SP is excreted manly by the kidneys with a slow clearance rate. The significant [99mTc]SP uptake in the heart and lungs may explain, at least partially, the pulmonary edema and effect cardiac observed by the envenoming. (author)

Spleen: development and functional evaluation

International Nuclear Information System (INIS)

Sty, J.R.; Conway, J.J.

1985-01-01

Despite the fact that the spleen has multiple functions, only one has been widely used for evaluation of the organ by imaging techniques (phagocytosis of /sup 99m/Tc sulfur colloid). The usual splenic uptake of this radiocolloid can by used to determine the size, location, and integrity of the organ. A major use of splenic radiocolloid imaging has been in the study of congenital defects. Thus, eventration of the diaphragm, accessory spleens, splenogonadal fusion, the asplenia and polysplenia syndromes, and the wandering spleen are amenable to study by means of intravenously administered radiocolloid. Interference with the splenic uptake of radiocolloid can be either focal or generalized (as in functional asplenia). Imaging of the spleen has a major role in evaluating suspected trauma of the organ and in following its clinical course. The return of splenic function after splenectomy (splenosis or accessory spleens) can be documented by radionuclide imaging, and likely by hematologic techniques when the volume of tissue is sufficiently large. The detection of intrasplenic lesions is important in tumor staging and as an alerting sign to an ongoing process. 96 references

Direct {sup 99m}Tc labeling of Herceptin (trastuzumab) by {sup 99m}Tc(I) tricarbonyl ion

Energy Technology Data Exchange (ETDEWEB)

Chen, W.-J.; Yen, C.-L.; Lo, S.-T.; Chen, K.-T. [Department of Biomedical Engineering and Environmental Sciences, National Tsing Hua University, Hsinchu 30013, Taiwan (China); Lo, J.-M. [Department of Biomedical Engineering and Environmental Sciences, National Tsing Hua University, Hsinchu 30013, Taiwan (China)], E-mail: jmlo@mx.nthu.edu.tw

2008-03-15

By simply incubating Herceptin (trastuzumab) with [{sup 99m}Tc(CO){sub 3}(OH{sub 2}){sub 3}]{sup +} ion in saline, a significant yield of {sup 99m}Tc-labeled trastuzumab was found to be achievable. The effective labeling may be based on that trastuzumab is inherent with endogenous histidine group to which {sup 99m}Tc(I) tricarbonyl ion can be strongly bound. For practical {sup 99m}Tc labeling processing, trastuzumab was purified beforehand from the commercial product, Herceptin (Genentech) via size exclusion chromatography to remove the excipient, {alpha}-histidine and a high-labeled yield could be obtained by incubating the purified trastuzumab with [{sup 99m}Tc(CO){sub 3}(OH{sub 2}){sub 3}]{sup +}. Retention of bioactivity of the {sup 99m}Tc(I)-labeled trastuzumab was validated using a cell binding test.

Synthesis and Preliminary Evaluation of a New 99mTc Labeled Substance P Analogue as a Potential Tumor Imaging Agent

Science.gov (United States)

Mozaffari, Saeed; Erfani, Mostafa; Beiki, Davood; Johari Daha, Fariba; Kobarfard, Farzad; Balalaie, Saeed; Fallahi, Babak

2015-01-01

Neurokinin 1 receptors (NK1R) are overexpressed on several types of important human cancer cells. Substance P (SP) is the most specific endogenous ligand known for NK1Rs. Accordingly,a new SP analogue was synthesized and evaluated for detection of NK1R positive tumors.[6-hydrazinopyridine-3-carboxylic acid (HYNIC)-Tyr8-Met(O)11-SP] was synthesized and radiolabeled with 99mTc using ethylenediamine-N,N'-diacetic acid (EDDA)and Tricine as coligands. Common physicochemical properties of radioconjugate were studied and in-vitro cell line biological tests were accomplished to determine the receptor mediated characteristics. In-vivo biodistribution in normal and tumor bearingnude mice was also assessed. The cold peptide was prepared in high purity (>99%) and radiolabeled with 99mTc at high specific activities (84-112GBq/µmol) with an acceptable labeling yield (>95%). The radioconjugate was stable in-vitro in the presence of human serum and showed 44% protein binding to human serumalbumin. In-vitro cell line studies on U373MG cells showed an acceptable uptake up to 4.91 ± 0.22% with the ratio of 60.21 ± 1.19% for its specific fraction and increasing specific internalization during 4 h. Receptor binding assays on U373MG cells indicated a mean Kd of 2.46 ± 0.43 nM and Bmax of 128925 ± 8145 sites/cell. In-vivo investigations determined the specific tumor uptake in 3.36 percent of injected dose per gram (%ID/g) for U373MG cells and noticeable accumulations of activity in the intestines and lung. Predominant renal excretion pathway was demonstrated. Therefore, this new radiolabeled peptide could be a promising radiotracer for detection of NK1R positive primary or secondary tumors. PMID:25561916

Survival Bayesian Estimation of Exponential-Gamma Under Linex Loss Function

Science.gov (United States)

Rizki, S. W.; Mara, M. N.; Sulistianingsih, E.

2017-06-01

This paper elaborates a research of the cancer patients after receiving a treatment in cencored data using Bayesian estimation under Linex Loss function for Survival Model which is assumed as an exponential distribution. By giving Gamma distribution as prior and likelihood function produces a gamma distribution as posterior distribution. The posterior distribution is used to find estimatior {\\hat{λ }}BL by using Linex approximation. After getting {\\hat{λ }}BL, the estimators of hazard function {\\hat{h}}BL and survival function {\\hat{S}}BL can be found. Finally, we compare the result of Maximum Likelihood Estimation (MLE) and Linex approximation to find the best method for this observation by finding smaller MSE. The result shows that MSE of hazard and survival under MLE are 2.91728E-07 and 0.000309004 and by using Bayesian Linex worths 2.8727E-07 and 0.000304131, respectively. It concludes that the Bayesian Linex is better than MLE.

Thermal separation method of preparing apyrogenic and sterile sup(99m)Tc2O7 and equipment for this method

International Nuclear Information System (INIS)

Machan, V.; Rusek, V.; Vlcek, J.; Kokta, L.; Smejkal, Z.; Rohacek, J.

1978-01-01

Pure apyrogenic and sterile sup(99m)Tc 2 O 7 is prepared from a mixture of technetium and molybdenum or their compounds, e.g., MoO 3 and Tc 2 O 7 . The mixture is mixed with a granular low-melting material and during separation is heated to 650 to 1000 degC for a time necessary for Tc 2 O 7 liberation. While cooling to room temperature Tc 2 O 7 is condensed outside the molybdenum region. The separation equipment consists of an outer tube with a ground surface extending into the heating system, a removable vessel, a replaceable cartridge for storing the mother nuclide, and a bacteriological filter. (H.S.)

Labeling of unnatural amino acids with sup(99m)Tc and tissue distribution of the labeled products in mice

International Nuclear Information System (INIS)

Tamemasa, Osamu; Goto, Rensuke; Takeda, Atsushi

1981-01-01

The selective affinity of amino acids for pancreas, due to its high rate of protein synthesis, has prompted us to synthesize new radio-labeled amino acids for pancreatic imaging. Labeling of 19 unnatural amino acids with sup(99m)Tc was tried in the usual way, and 10 labeled products were obtained with low yields. The highest distribution of radioactivity from all these labeled amino acids, which had been injected intravenously into mice, was found in the kidney, whereas little activity was found in the pancreas. Their low distributions in stomach suggest little dissociation of the labeled amino acids into sup(99m)TcO 4 - in mice. It is presumed that these labeled amino acids behave unlike their original amino acids in the body. (author)

HPLC characterization of clinically used sup(99m)Tc bone agents. Relative tissue distribution of fractionated components in mice

International Nuclear Information System (INIS)

Srivastava, S.C.; Meinken, G.E.; Richards, P.; Ford, L.A.; Benson, W.R.

1982-01-01

A study was undertaken to separate and characterize the components of clinically used (kit produced) 99m-Tc-Sn-MDP and 99m-Tc-Sn-EHDP preparations by high performance liquid chromatography (HPLC) using radioactivity detection mode. Tissue distribution studies of the HPLC fractionated species were carried out in mice in order to define the in vivo behavior of the individual components. Effect of many variables such as time, oxygen, pH, temperature, etc. on the above two systems was also studied in relation to the composition as determined by HPLC and changes, if any, in the biological behavior. The results demonstrate the unique capabilities of reverse phase HPLC for rapid and high resolution analysis of complex 99mTc radiopharmaceutical mixtures

Quantification of the magnetization-transfer contrast effect: can it yield additional information in differentiation of musculoskeletal lesions particularly in separation of benign from malignant lesions; Quantifizierung des Magnetization Transfer Contrast (MTC) Effektes durch Berechnung von MT-Quotienten: Ergeben sich Zusatzinformationen fuer die Differenzierung benigner und maligner Erkrankungen des Bewegungsapparates?

Energy Technology Data Exchange (ETDEWEB)

Vahlensieck, M.; Traeber, F.; Schild, H. [Radiologische Universitaetsklinik Bonn (Germany); Gieseke, J. [Philips Medizinsysteme (Germany)

1999-12-01

Purpose: To investigate the potential information of the amount of magnetization-transfer effect in musculoskeletal lesions and to compare MT ratios from benign and malignant musculoskeletal lesions. Material and Method: 49 patients with malignant tumors (3 osteosarcoma, 3 malignant fibrous histiocytoma, 4 chondrosarcoma, 2 Ewing sarcomas) and benign lesions (8 chondroma, 2 fibrous dysplasia, 3 osteoid-osteoma, 6 ganglion cyst, 3 cyst, 3 osteomyelitis, 4 tendinitis, 3 rotator cuff tear, 5 scar tissue) were scanned using routine MRI protocols including T{sub 1}- and T{sub 2}-weighted spin echo as well as T{sub 2}*-weighted gradient echo (FFE) sequences at 1.5 Tesla (ACS II, Philips Medical). Additionally MTC images were generated by combining the FFE sequence and the off-resonance MT technique (-1500 Hz off-resonance frequency, 1770 flip angle and 50 ms pulse duration). MT ratios were calculated as SI{sub o}-SI{sub m}/SI{sub o}. Results: The MT ratio of benign lesions was 26{+-}15%, that of malignant lesions was 22{+-}6%. The difference was statistically not significant. As expected muscle showed a high MT ratio of 50{+-}8%. Scar tissue demonstrated an MT ratio of 39{+-}16% which was significantly higher than the tumor MT ratios. Conclusion: MTC (MT ratios) failed to show significant differences between benign and malignant lesions as was expected due to basic differences in cellularity, rate of mitosis and chromatin content. MTC might however gain more importance in separating scar tissue from recurrent tumor in the future. (orig.) [German] Zielsetzung: Durch die Quantifizierung des Magnetization Transfer Contrastes sollte untersucht werden, ob sich Zusatzinformationen in der Magnetresonanztomographie des Stuetz- und Bewegungsapparates ergeben. Insbesondere sollte ermittelt werden, ob gut- und boesartige Laesionen unterschiedliche MT-Quotienten aufweisen. Material und Methode: 49 Patienten mit boesartigen Tumoren (3 Osteosarkom, 4 Chondrosarkom, 3 Malignes

The accumulation of sup(95m)Tc from sea water by juvenile lobsters (Homarus gammarus L.)

International Nuclear Information System (INIS)

Swift, D.J.

1985-01-01

The uptake and retention of technetium from sea water by juvenile lobsters, and the effects of moulting on these processes, has been studied using sup(95m)Tc as a tracer. Accumulation was rapid with whole body concentration factors of over 2000 being measured in some lobsters. Uptake was highest immediately before a moult; post-moult there was a fall in accumulation. No simple mathematical equation for technetium accumulation with time was found. The technetium concentration in the moulted exoskeleton increased with time of exposure of the lobsters but never exceeded 2% of the whole body value. The highest percentage of the whole body activity was found in the digestive gland; the green gland had the highest concentration factor. Technetium excretion, following 64 d of accumulation, could be expressed as an exponential rate of loss. The biological half-time was calculated as 53 d. Moulted exoskeletons from these lobsters contained approximately 0.6% of the day zero whole body activity. (author)

99mTc-tagged chicken liver as a marker of solid food in the human stomach.

Science.gov (United States)

Meyer, J H; MacGregor, I L; Gueller, R; Martin, P; Cavalieri, R

1976-04-01

Past measurement of gastric emptying of solid food in man has depended on external counting of surface-absorbed isotopes without verification that isotopic labels remain attached to solid food in the stomach. In this study chicken liver was isotopically labeled with 99mTc incorporated uniformly and intracellularly throughout the liver substance. In vitro studies showed less than 10% loss of 99mTc from liver incubated with pepsin HC1. By contrast, up to 90% of 51Cr absorbed to scrambled eggs became detached under similar conditions. In feeding experiments less than 10% of 99mTc was liberated from fed 99mTc liver, while significantly more 51Cr became detached from egg under identical intragastric conditions. We conclude that 99mTc-tagged chicken liver is an adequate marker of the rate of emptying of solid food and appears to be more reliable than 51Cr-labeled scrambled eggs from which 51Cr dissociates in the stomach.

Analytical methods for determination of radiochemical and radionuclidic purity of radiopharmaceuticals containing sup(99m)Tc and sup(113m)In. Part of a coordinated programme on radiopharmaceuticals

International Nuclear Information System (INIS)

Galatzeanu, I.

1974-01-01

The obtained results on radiochemical and radionuclidic purities determination of sup(99m)Tc and sup(113m)In-radiopharmaceuticals proved to be a good tool for small hospital units and laboratories in satisfying their duty to improve the quality control. The complicated behaviour of technetium in aqueous solutions during the preparation of radiopharmaceuticals, needs further research work to elucidate the mechanisms of interaction of reduced species with media and their disproportionation

Radioactive excretion in human milk following administration of /sup 99m/Tc macroaggregated albumin

International Nuclear Information System (INIS)

Pittard, W.B.; Merkatz, R.; Fletcher, B.D.

1982-01-01

Albumin-tagged sodium pertechnetate (technetium) is routinely used in nuclear medicine for scanning procedures of the lung. The rate of excretion of this radionuclide into breast milk and the resultant potential radiation hazard to the nursing infant have received little attention. Therefore the milk from a nursing mother who required a lung scan because of suspected pulmonary emboli using an intravenous injection of 4 mCi of /sup 99m/Tc macroaggregated human serum albumin was monitored. Albumin tagging severely limited the entrance of technetium into her milk and the radioactivity of the milk returned to base line by 24 hours. A total of 2.02 muCi of technetium was measured in the 24-hour milk collection after technetium injection and 94% of this amount was excreted by 15.5 hours. This amount of technetium administered orally to a newborn would deliver a total body radiation dose of .3 mrad. Therefore, an infant would receive trivial doses of radiation if breast-feeding were resumed 15.5 hours after administration of the radionuclide to the mother and nursing can clearly be resumed safely 24 hours after injection

Approximation solutions for indifference pricing under general utility functions

NARCIS (Netherlands)

Chen, An; Pelsser, Antoon; Vellekoop, M.H.

2008-01-01

With the aid of Taylor-based approximations, this paper presents results for pricing insurance contracts by using indifference pricing under general utility functions. We discuss the connection between the resulting "theoretical" indifference prices and the pricing rule-of-thumb that practitioners

Approximate Solutions for Indifference Pricing under General Utility Functions

NARCIS (Netherlands)

Chen, A.; Pelsser, A.; Vellekoop, M.

2007-01-01

With the aid of Taylor-based approximations, this paper presents results for pricing insurance contracts by using indifference pricing under general utility functions. We discuss the connection between the resulting "theoretical" indifference prices and the pricing rule-of-thumb that practitioners

Studies on the distribution of hematopoietic bone marrow by bone marrow scintigraphy, 2. The bone marrow distribution in leukemia

Energy Technology Data Exchange (ETDEWEB)

Fujimori, K [Kyoto Univ. (Japan). Faculty of Medicine

1976-04-01

Distribution of the leukemic marrow was investigated in 42 cases by bone marrow scintigraphy using sup(99m)Tc sulfur colloid in association with clinical findings and ferrokinetics studies in order to clarify hematopoietic function in leukemia. 17 of chronic myelogenous leukemia, 3 of lymphatic leukemia, 2 of monocytic leukemia, 7 of atypical leukemia and one of erythroleukemia. 12 acute myelogenous leukemia were classified into 3 types A, B and C. Type A showed the distribution similar to those obtained with normal controls. Ferrokinetics studies, however, indicated complete absence of erythropoiesis. Type B showed complete lack of sup(99m)Tc activity in usual marrow sites, although ferrokinetics data showed normal erythropoeitic function. Type C showed abnormal concentration of sup(99m)Tc sulfur colloid in the tibiae. 17 chronic myelogenous leukemia showed reduced sup(99m)Tc activity in usual marrow sites and remarkable expanded marrow extending into distal femurs, proximal and distal tibiae and bones of feet. 2 acute lymphotic leukemia patients showed complete absence of sup(99m)Tc activity. The one chronic type showed almost normal distribution. Monocytic leukemia showed decreased marrow distribution in the sternum and vertebrae. Of 6 atypical leukemias one showed almost normal distribution. The others, including a case with hypoplastic luekemia, demonstrated marrow extension similar to that observed in chronic myelogenous leukemia or monocytic leukemia. Erythroleukemia showed increased concentrations of sup(99m)Tc activity in the usual marrow sites and marked marrow expansion throughout all long bones. These results suggest that there is a discrepancy between bone marrow distribution and hematopoietic function in the cases of acute myelogenous leukemia.

Studies on the distribution of hematopoietic bone marrow by bone marrow scintigraphy, 2

International Nuclear Information System (INIS)

Fujimori, Katsuhiko

1976-01-01

Distribution of the leukemic marrow was investigated in 42 cases by bone marrow scintigraphy using sup(99m)Tc sulfur colloid in association with clinical findings and ferrokinetics studies in order to clarify hematopoietic function in leukemia. 17 of chronic myelogenous leukemia, 3 of lymphatic leukemia, 2 of monocytic leukemia, 7 of atypical leukemia and one of erythroleukemia. 12 acute myelogenous leukemia were classified into 3 types A, B and C. Type A showed the distribution similar to those obtained with normal controls. Ferrokinetics studies, however, indicated complete absence of erythropoiesis. Type B showed complete lack of sup(99m)Tc activity in usual marrow sites, although ferrokinetics data showed normal erythropoeitic function. Type C showed abnormal concentration of sup(99m)Tc sulfur colloid in the tibiae. 17 chronic myelogenous leukemia showed reduced sup(99m)Tc activity in usual marrow sites and remarkable expanded marrow extending into distal femurs, proximal and distal tibiae and bones of feet. 2 acute lymphotic leukemia patients showed complete absence of sup(99m)Tc activity. The one chronic type showed almost normal distribution. Monocytic leukemia showed decreased marrow distribution in the sternum and vertebrae. Of 6 atypical leukemias one showed almost normal distribution. The others, including a case with hypoplastic luekemia, demonstrated marrow extension similar to that observed in chronic myelogenous leukemia or monocytic leukemia. Erythroleukemia showed increased concentrations of sup(99m)Tc activity in the usual marrow sites and marked marrow expansion throughout all long bones. These results suggest that there is a discrepancy between bone marrow distribution and hematopoietic function in the cases of acute myelogenous leukemia. (J.P.N.)

Design and setup of a portable stirring device for transfer and dissolution of {sup 99}Mo applied to the use of a {sup 99m}Tc generator; Diseno e implementacion de un modulo portatil para el traslado y disolucion de Mo-99 aplicado al empleo de un generador de Tc-99m

Energy Technology Data Exchange (ETDEWEB)

Lopez, Yon [Universidad Nacional de Ingenieria, Lima (Peru). Facultad de Ingenieria Mecanica; Urquizo, Rafael [Universidad Tecnologica del Peru, Lima (Peru). Facultad de Ingenieria de Sistemas y Electronica; Mendoza, Pablo [Direccion de Investigacion y Desarrollo, Instituto Peruano de Energia Nuclear, Lima (Peru); Rojas, Jorge [Universidad Nacional Mayor San Marcos, Lima (Peru). Facultad de Quimica e Ingenieria Quimica

2014-07-01

This work shows the design and implementation of a portable magnetic stirring device for transfer and efficient dissolution of Mo{sub O}3 coupled to a {sup 99m}Tc generator prototype. The development of this equipment will enable an efficient and safe transfer of {sup 99}Mo at a 2 Ci of maximum activity from the nuclear reactor Huarangal to the point of operation of the {sup 99m}Tc generator equipment. This article describes the mechanical design, volume and shielding calculation, the electronics design and the programmable speed control of the stirring system for radioactive samples. (authors).

Accuracy of 99Molybdenum assays in /sup 99m/Technetium solutions

International Nuclear Information System (INIS)

Williams, C.C.; Kereiakes, J.G.; Grossman, L.W.

1981-01-01

A study was performed to determine the accuracy of 99 Mo measurements using three commercial dose calibrators with their 99 Mo assay shields. One 99 Mo assay shield allowed excessive penetration by the lower energy /sup 99m/Tc photons, resulting in the calibrator's falsely high interpretation of the activity of 99 Mo present in the high-activity /sup 99m/Tc eluates. All three calibrators performed adequately with a National Bureau of Standards 99 Mo standard in equilibrium with /sup 99m/Tc. By using low-activity aliquots of 99 Mo and /sup 99m/Tc, a low-level linearity test was performed. Only one of the calibrators was found to reflect accurately the activity of 99 Mo present under all conditions tested

Imaging-based liver function tests. Past, present and future; Bildgestuetzte Leberfunktionstests. Stand der Technik und zukuenftige Entwicklungen

Energy Technology Data Exchange (ETDEWEB)

Geisel, D.; Hamm, B.; Denecke, T. [Charite, Campus Virchow-Klinikum, Berlin (Germany). Dept. of Diagnostic and Interventional Radiology; Luedemann, L. [Essen University Hospital (Germany). Dept. of Medical Physics

2015-10-15

Preoperative assessment of liver function and prediction of postoperative functional reserve are important in patients scheduled for liver resection. While determination of absolute liver function currently mostly relies on laboratory tests and clinical scores, postoperative remnant liver function is estimated volumetrically using imaging data obtained with computed tomography (CT) or magnetic resonance imaging (MRI). Accurate estimation of hepatic function is also relevant for intensive care patients, oncologic patients, and patients with diffuse liver disease. The indocyanine green (ICG) test is still the only established test for estimating true global liver function. However, more recent tools such as the LiMAx test also allow global assessment of hepatic function. These tests are limited when liver function is inhomogeneously distributed, which is the case in such conditions as unilateral cholestasis or after portal vein embolization. Imaging-based liver function tests were first developed in nuclear medicine and, compared with laboratory tests, have the advantage of displaying the spatial distribution of liver function. Nuclear medicine scans are obtained using tracers such as 99mTc galactosyl and 99mTc mebrofenin. Liver function is typically assessed using planar scintigraphy. However, three-dimensional volumetry is possible with single-photon emission computed tomography (SPECT-CT). Another technique for image-based liver function estimation is Gd-EOB-enhanced MRI. While metabolization of Gd-EOB in the body is similar to that of ICG and mebrofenin, its distribution in the liver can be displayed by MRI with higher temporal and spatial resolution. Moreover, MRI-based determination of liver function can be integrated into routine preoperative imaging. This makes MRI an ideal candidate for preoperative determination of liver function, though the best pulse sequence and the parameter to be derived from the image information remain to be identified. Another

When did a Mediterranean-type climate originate in southwestern Australia?

Science.gov (United States)

Lamont, Byron B.; He, Tianhua

2017-09-01

Knowing the environments under which biota have evolved is essential for understanding the functional traits that they possess. Here, we ask when a Mediterranean-type climate (MTC) originated in Western Australia that might help to explain some of its special plant adaptations to summer drought and heat, mild wet winters and intense summer fires. Periodic drought and fire can be traced back to the Cretaceous in southwestern Australia (SWA) but its seasonality is unknown. Previous estimates of the origin of the MTC in SWA have varied from 30 to 3 million years ago (Ma). An early proposal was that it originated in northwestern Australia 30 Ma and migrated south to its present location for which we find independent support. We collated 47 cases of what is currently known about the time of origin of adaptive responses to summer drought and heat, wet winters and periodic intense fire among flowering plants in SWA. About 15% arose in the 40-30-million-year (My) period, 32% in the 30-20-My period and 47% in the 20-10-My period, suggesting that a MTC may have been widespread in SWA by the mid-Miocene, but there may have been local appearances (proto-MTC) up to 20 My earlier. Uncertainties remain about the location of lineages at various times, the fitness benefits of apparent adaptive traits and their confinement to a MTC, and the significance of the origin versus the onset of diversification of traits. The current dearth of C4 grasses in SWA is consistent with other indications of the absence of a prior history of a summer-dominant rainfall, suggesting that the current MTC arose from a uniform-rainfall climate. Other lines of evidence that might refine these findings include the chemical composition of, and application of geochronometers to, laterites, carbonates and corals that have been used with success elsewhere. We conclude by noting that there may have been a mixture of climates for much of the time, indicated by the persistence of a few rainforest species up to 3

Simple differential functional study of the kidney using sup(99m) technetium DMSA

International Nuclear Information System (INIS)

Handmaker, H.

1976-01-01

A simple technique has been developed to study the differential kidney function. It involves the intravenous injection of a product labelled with sup(99m)Tc, which possesses in vivo the characteristics of organo-mercurial derivatives. High-resolution kidney images are obtained, eliminating the excretion component which may be obtained with DTPA type products studying the glomerular filtration. The absolute quantitative uptake and the left kidney to right kidney activity ratio were measured successfully. This technique should find an increasing application in the evaluation of patients suffering from various kidney disorders including hypertension and acute pyelonephritis [fr

Advantages and limits of sup(99m)Tc pyrophosphate scintigraphy in the study of joint diseases

International Nuclear Information System (INIS)

Caillard, J.-F.

1975-01-01

The results of sup(99m)Tc pyrophosphate bone scintigraphy are studied for a wide range of joint diseases. 215 scintigraphs are analysed, the results compared with those of authors who have used not only Tc phosphates but also other isotopes after comparison of their advantages and disadvantages, and possible applications suggested for each type of lesion. - The 99m Tc pyrophosphate scintigraphic examination is simple, harmless (a whole-skeleton examination delivers only 80 millirads to the narrow whereas a set of spine and pelvis X-rays delivers 325), reliable and highly sensitive, often anticipating data from radiographic examinations. - In the majority of developing joint diseases of whatever kind, apart from arthroses and certain osteolytic lesions unaccompanied by any healing reaction, a hyperfixation is observed. Generally speaking a scintigraph may be requested whenerver an evolutive bone lesion is suspected in the absence of clinical, radiological and biological evidence. The major disadvantage of the method is that, being highly sensitive, it lacks specificity and is hence unable alone to provide an etiological diagnosis [fr

Some observations on the use of iodine-123 for thyroid imaging

International Nuclear Information System (INIS)

Ryo, U.Y.; Pinsky, S.

1985-01-01

Efficacy of /sup 99m/Tc and 123 I for thyroid imaging was studied in 122 subjects with a variety of thyroid abnormalities. Both agents produced images that were equivalent in quality in 51 subjects, the image with 123 I was in better quality in 22, and the /sup 99m/Tc image was better in 9. In the remaining 40 cases, discordant findings existed between the 123 I image and /sup 99m/Tc image. In the majority of cases, i.e., 32 or 40, the discrepancy was caused by hot or warm lesions on the /sup 99m/Tc image that became cold or normal (nonvisualization) on the 123 I image. Advantages with /sup 99m/Tc appeared to be (1) the saving of time and cost for patients and physicians and (2) superior sensitivity in detecting thyroid lesions, whereas the advantages with 123 I appeared to be better quality of thyroid images and accurate representation of function of thyroid nodules

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

Modification of PLGA nanoparticles for improved properties as a 99mTc-labeled agent in sentinel lymph node detection.

Science.gov (United States)

Subramanian, Suresh; Pandey, Usha; Gugulothu, Dalapathi; Patravale, Vandana; Samuel, Grace

2013-10-01

We have earlier reported on the possible application of poly [lactide (co-glycolide)] (PLGA) nanoparticles of suitable size to serve as a (99m)Tc-labeled diagnostic tracer in sentinel lymph node detection (SLND). Additional efforts have now been made to improve both the radiolabeling yield and the biological efficacy by modifying the PLGA particles. Two approaches were taken, one based on in situ loading of mebrofenin inside PLGA nanoparticles and the second one based on functionalization of existing terminal carboxylic acid groups on the nanoparticle surface with p-aminobenzyl diethylenetriamine pentaacetic acid (p-NH2-Bz-DTPA) for enhanced availability of functional groups suitable for (99m)Tc complexation. The modified PLGA derivatives were purified and characterized. Radiolabeling of the modified PLGA nanoparticles was carried out with (99m)Tc using stannous chloride as the reducing agent. Mebrofenin encapsulated PLGA nanoparticles (mebrofenin-PLGA) did not show any significant improvement in the radiolabeling yield in comparison to the earlier reported "plain" PLGA nanoparticles, probably due to inaccessibility of the mebrofenin moiety to (99m)Tc upon encapsulation. DTPA-conjugated PLGA nanoparticles (DTPA-PLGA) showed appreciable improvement in radiolabeling yield under more moderate reaction conditions and better stability. In the biological evaluation performed in Wistar rat model, (99m)Tc-DTPA-PLGA nanoparticles showed a considerable increase in uptake in the sentinel node and the percentage popliteal extraction of the preparation was also higher. (99m)Tc-mebrofenin-PLGA did not show any improvement in SLN uptake over plain PLGA nanoparticles. The above results suggest that surface modification of PLGA by covalently coupling DTPA to PLGA nanoparticles prior to (99m)Tc labeling appears to be a superior approach to achieve a suitable (99m)Tc-labeled PLGA nanoparticle preparation for SLND.

Stability 'in vivo' and 'in vitro' of the diisopropyl-IDA sup(99m)Tc

International Nuclear Information System (INIS)

Verdera, E.S.; Leon, A.S.; Robles, A.M.; Correa, Angela; Oliver, Guillermo; Gamma, Santos; Lanzzeri, Stella; Mitta, A.E.A.

1982-01-01

The 'in vitro' and 'in vivo' stability of the diisopropyl (IDA-3) kit in solution and of the molecule labelled with sup(99m)Tc was studied. The following items were studied a) shelf life of the kit in solution b) 'in vitro' stability of the labelled molecule c) distribution and elimination kinetics d) identification and behaviour of the excretion products. Chromatographic control shows 95% yield of labelled product after 20 days storage at 4 deg C and 92% yield after 30 days in the same conditions; biological distribution was good in both cases. Regarding the 'in vitro' stability, no alteration was observed within the 4 hours after its preparation. The stability of the complex was determined by the reaction between sup(99m)TcIDA-3 and DTPA. Analysis by electrophoresis shows the complex to be stable even with DTPA concentrations 5 times higher. Kinetics of distribution and elimination of the labelled molecule, in animals, were afterwards confirmed by sequential scintigraphic images in humans. The excretion of unaltered sup(99m)Tc-IDA by biliary and urinary ways was confirmed by cromatographic and electrophoretic analysis of bladder and gall bladder content and by determination of its biological distribution. (author) [es

BAYESIAN ESTIMATION OF THE SHAPE PARAMETER OF THE GENERALISED EXPONENTIAL DISTRIBUTION UNDER DIFFERENT LOSS FUNCTIONS

Directory of Open Access Journals (Sweden)

SANKU DEY

2010-11-01

Full Text Available The generalized exponential (GE distribution proposed by Gupta and Kundu (1999 is an important lifetime distribution in survival analysis. In this article, we propose to obtain Bayes estimators and its associated risk based on a class of  non-informative prior under the assumption of three loss functions, namely, quadratic loss function (QLF, squared log-error loss function (SLELF and general entropy loss function (GELF. The motivation is to explore the most appropriate loss function among these three loss functions. The performances of the estimators are, therefore, compared on the basis of their risks obtained under QLF, SLELF and GELF separately. The relative efficiency of the estimators is also obtained. Finally, Monte Carlo simulations are performed to compare the performances of the Bayes estimates under different situations.

Identificación y caracterización sindromológica desde la medicina tradicional china (MTC) del cuadro clínico de mujeres ingresadas al Hospital Gíneco-Obstétrico Isidro Ayora (HGOIA) y al Hospital Carlos Andrade Marín (HCAM) con diagnóstico biomédico de preeclampsia CIE10 O14

OpenAIRE

Mena Echeverría, Fabián Eduardo

2017-01-01

Se estudiaron 30 casos de mujeres ingresadas con diagnóstico de preeclampsia en los hospitales Gíneco Obstétrico Isidro Ayora (HGOIA) y Carlos Andrade Marín (HCAM) de Quito, entre los meses de junio y septiembre de 2016, aplicando la historia clínica de medicina tradicional china ACUMOX, con el fin de identificar los síndromes de la medicina tradicional china (MTC) en estas 30 mujeres. El cuadro clínico de estas mujeres corresponde a 12 síndromes diferentes, desde la óptica de la MTC, de los ...

Adsorption kinetics of {sup 201}Tl and migration of {sup 99m}Tc in natural soils; Cinetica de adsorcion de {sup 201}Tl y migracion de {sup 99m}Tc en suelos naturales

Energy Technology Data Exchange (ETDEWEB)

Rodriguez N, C. E. [Instituto Tecnologico de Toluca, Av. Tecnologico s/n, Fraccionamiento La Virgen, 52149 Metepec, Estado de Mexico (Mexico); Monroy G, F.; Fernandez R, E.; Anguiano A, J., E-mail: estefany_rodriguezn@hotmail.com [ININ, Carretera Mexico-Toluca s/n, 52750 Ocoyoacac, Estado de Mexico (Mexico)

2012-10-15

The safety is very important in facilities where radioactive wastes are stored. One of the necessary characteristics of the site where these wastes will be disposed is the soil permeability, since a waterproof terrain avoids the diffusion and radionuclide transport in the leakages case. The objective of this work is to study the adsorption kinetics of {sup 201}Tl and the migration of {sup 99m}Tc in natural soil samples. The adsorption kinetics was determined starting from the obtaining of the retention coefficient of the thallium (static method) at different contact times. The technetium diffusion was studied by means of the dynamic method with different soil particles sizes. The results showed that the thallium is totally adsorbed starting from 20 h of contact among this and the mean. On the other hand, the technetium is very mobile in the soil, since it was possible to extract the majority of the tracer with little solvent. Also, it was found that for each soil gram the double water will be needed to leach the technetium almost in its entirety. Moreover, influence exists of the particle size in the migration velocity from the radiotracer to the most mobile being in major sizes than 2 mm that in minor size. (Author)

Quality control studies of {sup 99}Mo used in {sup 99}Mo/{sup 99m}Tc generators produced at IPEN/CNEN-SP, Brazil

Energy Technology Data Exchange (ETDEWEB)

Said, Daphne S.; Brambilla, Tania P.; Matsuda, Margareth M.N.; Osso Junior, Joao A., E-mail: daphnesaid@usp.br, E-mail: taniabrambilla@yahoo.com.br, E-mail: mmatsuda@ipen.br, E-mail: jaosso@ipen.br [Instituto de Pesquisas Energeticas e Nucleares (IPEN/CNEN-SP), Sao Paulo, SP (Brazil)

2015-07-01

{sup 99m}Tc is the most used radionuclide in nuclear medicine. In Brazil, the {sup 99}Mo/{sup 99m}Tc generators are produced exclusively by the Center of Radiopharmacy at IPEN-CNEN/SP, by importing {sup 99}Mo from different suppliers. {sup 99}Mo (t{sub 1/2} = 66 h) is a fission product of {sup 235}U, therefore, it can be accompanied by several radioisotopes that are highly prejudicial for human health, demanding a strict quality control of this product for generators safe use. The European Pharmacopoeia established some parameters and limits that evaluate the quality of the solution of sodium [{sup 99}Mo]molybdate, that is used as raw material for generator's production. The European Pharmacopoeia also recommends some analytical methods to perform these evaluations, however, it has been observed difficulties on the implementation of these methods by the generator's producers. These difficulties are probably related to the lack of practicability of the proposed methods and the extensive list of utilized reagents. In this work some procedures of the European Pharmacopoeia's quality control method for {sup 99}Mo were evaluated. Different types of solid phase exchanger cartridges were tested for retention of {sup 99}Mo in 3 different conditions. Cartridges that presented percentages of retention higher than 90% were also tested for separation of {sup 99}Mo from possible contaminants (Ru e Te). The results shown that solid phase exchanger cartridges that presented percentages of retention of Mo higher than 90% also presented significant percentages of retention of Ru and Te. An alternative method for separation of {sup 99}Mo from {sup 131}I (other contaminant) are also proposed. (author)

Examining the Functional Specification of Two-Parameter Model under Location and Scale Parameter Condition

OpenAIRE

Nakashima, Takahiro

2006-01-01

The functional specification of mean-standard deviation approach is examined under location and scale parameter condition. Firstly, the full set of restrictions imposed on the mean-standard deviation function under the location and scale parameter condition are made clear. Secondly, the examination based on the restrictions mentioned in the previous sentence derives the new properties of the mean-standard deviation function on the applicability of additive separability and the curvature of ex...

Scatter and cross-talk correction for one-day acquisition of 123I-BMIPP and 99mtc-tetrofosmin myocardial SPECT.

Science.gov (United States)

Kaneta, Tomohiro; Kurihara, Hideyuki; Hakamatsuka, Takashi; Ito, Hiroshi; Maruoka, Shin; Fukuda, Hiroshi; Takahashi, Shoki; Yamada, Shogo

2004-12-01

123I-15-(p-iodophenyl)-3-(R,S)-methylpentadecanoic acid (BMIPP) and 99mTc-tetrofosmin (TET) are widely used for evaluation of myocardial fatty acid metabolism and perfusion, respectively. ECG-gated TET SPECT is also used for evaluation of myocardial wall motion. These tests are often performed on the same day to minimize both the time required and inconvenience to patients and medical staff. However, as 123I and 99mTc have similar emission energies (159 keV and 140 keV, respectively), it is necessary to consider not only scattered photons, but also primary photons of each radionuclide detected in the wrong window (cross-talk). In this study, we developed and evaluated the effectiveness of a new scatter and cross-talk correction imaging protocol. Fourteen patients with ischemic heart disease or heart failure (8 men and 6 women with a mean age of 69.4 yr, ranging from 45 to 94 yr) were enrolled in this study. In the routine one-day acquisition protocol, BMIPP SPECT was performed in the morning, with TET SPECT performed 4 h later. An additional SPECT was performed just before injection of TET with the energy window for 99mTc. These data correspond to the scatter and cross-talk factor of the next TET SPECT. The correction was performed by subtraction of the scatter and cross-talk factor from TET SPECT. Data are presented as means +/- S.E. Statistical analyses were performed using Wilcoxon's matched-pairs signed-ranks test, and p corrected total count was 26.0 +/- 5.3%. EDV and ESV after correction were significantly greater than those before correction (p = 0.019 and 0.016, respectively). After correction, EF was smaller than that before correction, but the difference was not significant. Perfusion scores (17 segments per heart) were significantly lower after as compared with those before correction (p correction revealed significant differences in EDV, ESV, and perfusion scores. These observations indicate that scatter and cross-talk correction is required for one

Age-related variance in decisions under ambiguity is explained by changes in reasoning, executive functions, and decision-making under risk.

Science.gov (United States)

Schiebener, Johannes; Brand, Matthias

2017-06-01

Previous literature has explained older individuals' disadvantageous decision-making under ambiguity in the Iowa Gambling Task (IGT) by reduced emotional warning signals preceding decisions. We argue that age-related reductions in IGT performance may also be explained by reductions in certain cognitive abilities (reasoning, executive functions). In 210 participants (18-86 years), we found that the age-related variance on IGT performance occurred only in the last 60 trials. The effect was mediated by cognitive abilities and their relation with decision-making performance under risk with explicit rules (Game of Dice Task). Thus, reductions in cognitive functions in older age may be associated with both a reduced ability to gain explicit insight into the rules of the ambiguous decision situation and with failure to choose the less risky options consequently after the rules have been understood explicitly. Previous literature may have underestimated the relevance of cognitive functions for age-related decline in decision-making performance under ambiguity.

Stochastic optimization under risk constraint and utility functions

International Nuclear Information System (INIS)

Seck, B.

2008-09-01

In a context of concurrence and emergence of energy markets, the production of electricity is affected by the new sources of risks which are the price variations on the energy markets. These new sources of risks generate a new risk: the market risk. In this research, the author explores the possibility of introducing constraints, expressed by measurements of risk, into the process of optimization of electricity production when financial contracts are signed on the energy market. The author makes the distinction between the engineering approach (taking the risk into account by risk measurements) and the economist approach (taking the risk into account by utility functions). After an overview of these both approaches in a static framework, he gives an economical formulation (a Maccheroni type one) for a static optimization problem under a risk constraint when the risk measurement is written under the form of an expected infimum like the variance, the 'conditional value at risk', and so on. The obtained results are then extended to a dynamic optimization framework under risk constraints. A numerical application of this approach is presented to solve a problem of electricity production management under a constraint of 'conditional value at risk' on a middle term

Inflammatory Profile of Awake Function-Controlled Craniotomy and Craniotomy under General Anesthesia

Science.gov (United States)

Klimek, Markus; Hol, Jaap W.; Wens, Stephan; Heijmans-Antonissen, Claudia; Niehof, Sjoerd; Vincent, Arnaud J.; Klein, Jan; Zijlstra, Freek J.

2009-01-01

Background. Surgical stress triggers an inflammatory response and releases mediators into human plasma such as interleukins (ILs). Awake craniotomy and craniotomy performed under general anesthesia may be associated with different levels of stress. Our aim was to investigate whether those procedures cause different inflammatory responses. Methods. Twenty patients undergoing craniotomy under general anesthesia and 20 patients undergoing awake function-controlled craniotomy were included in this prospective, observational, two-armed study. Circulating levels of IL-6, IL-8, and IL-10 were determined pre-, peri-, and postoperatively in both patient groups. VAS scores for pain, anxiety, and stress were taken at four moments pre- and postoperatively to evaluate physical pain and mental duress. Results. Plasma IL-6 level significantly increased with time similarly in both groups. No significant plasma IL-8 and IL-10 change was observed in both experimental groups. The VAS pain score was significantly lower in the awake group compared to the anesthesia group at 12 hours postoperative. Postoperative anxiety and stress declined similarly in both groups. Conclusion. This study suggests that awake function-controlled craniotomy does not cause a significantly different inflammatory response than craniotomy performed under general anesthesia. It is also likely that function-controlled craniotomy does not cause a greater emotional challenge than tumor resection under general anesthesia. PMID:19536349

Born-again spleen. Return of splenic function after splenectomy for trauma

International Nuclear Information System (INIS)

Pearson, H.A.; Johnston, D.; Smith, K.A.; Touloukian, R.J.

1978-01-01

We assessed splenic activity after splenectomy by interference phase microscopical examination of circulating red cells. Normal eusplenic children had a low number (<1%) of red cells with surface indentations or pits. About 20% of red cells of children who had electively been subjected to splenectomy for hematologic indications were pitted. Thirteen of 22 children who had had emergency splenectomy because of traumatic injury had a low percentage of pitted red cells, suggesting a return of splenic function. In five of these children a /sup 99m/Tc sulfur colloid scan demonstrated multiple nodules of recurrent splenic tissue. In contrast to the prevailing opinion that splenosis is rare, we have found it to be a frequent occurrence. Return of splenic function may, in part, account for the low frequency with which overwhelming bacterial sepsis and meningitis have been documented after splenectomy for traumatic indications

Synthesis of Ethane-1-Hydroxy-1,1-diphosphonic acid (EHDP) and preparation of labeled kits by 99mTc for bone studies

International Nuclear Information System (INIS)

Yassin, T.; Assaad, T.; Ghanem, E.; Ajaia, R.; Karajoli, N.

2013-08-01

Ethane-1-Hydroxy-1,1-diphosphonic acid monohydrate (EHDP) is very important precursor in radiopharmaceutical applications for bone diagnosis after labeling with 99mTc, was synthesized in high yield and purity. The compound was characterized by spectroscopic method. EHDP kit for bone imaging after labeling with technetium 99m was prepared according to an optimum conditions, Each vial contains 15 mg of EHDP and 25 mg of stannous chloride SnCl2. The prepared kit showed high quality satisfying the requirements of international pharmacopeias from of physical, chemical and radiochemical properties. The labeling yield exceeded 95% with an average value 99.6%. Biodistribution study of 99mTc-EHDP showed better clearance after three hours of injection in comparison with 99mTc-MDP kit (author).

Evaluation of 99mTc labelled human immunoglobulin (99mTc-HIG) in infection/inflammatory foci imaging. Final report for the period 15 December 1996 - 15 August 1997

International Nuclear Information System (INIS)

Shimpi, H.H.

1997-10-01

The aim of the study was to investigate whether the labelling efficiency biodistribution and inflammatory focus detection are dependent on the source of the human immunoglobulin G (HIG) and the chelating agent used in the labelling of the HIG with 99mTc. Three forms of immunoglobulins; Gamma venin P, Intraglobulin F and Sandoglobulin were used in this study. Reduction of HIG was done by 2-mercaptoethanol at molar ratio 1000:1, with 30 minutes reaction time at room temperature. The reduced HIG was then purified, membrane filtered aliquoted and lyophilised. Lyophilised HIG was dissolved in sterile normal saline and chelated with one of the following ligands Sn-MDP, SN PYP, Sn DTPA, SN-GH and Sn-citrate and then added 99m Tc04 for labelling. The radiochemical purity of the labelled compound was 90%. The biodistribution studies were done wistar rats where in the experimental groups were sacrifised at 3,5 and 24 hours following 99mTc HIG injection intravenously. Imaging studies were carried out in rabbits. Sterile inflammatory lesions were produced in the thigh muscle of these animals by injection of turpentine oil and the contralateral thigh muscle served as-controls. The results showed that there was no significant difference in biodistribution and inflammatory focus uptake of 9gmTc HIG with respect to the sources of HIG. There was favourable biodistribution characteristics when the ligands used were Sn MDP and Sn-Citrate

Inflammatory Profile of Awake Function-Controlled Craniotomy and Craniotomy under General Anesthesia

Directory of Open Access Journals (Sweden)

Markus Klimek

2009-01-01

Results. Plasma IL-6 level significantly increased with time similarly in both groups. No significant plasma IL-8 and IL-10 change was observed in both experimental groups. The VAS pain score was significantly lower in the awake group compared to the anesthesia group at 12 hours postoperative. Postoperative anxiety and stress declined similarly in both groups. Conclusion. This study suggests that awake function-controlled craniotomy does not cause a significantly different inflammatory response than craniotomy performed under general anesthesia. It is also likely that function-controlled craniotomy does not cause a greater emotional challenge than tumor resection under general anesthesia.

A Floquet-Green's function approach to mesoscopic transport under ac bias

International Nuclear Information System (INIS)

Wu, B H; Cao, J C

2008-01-01

The current response of a mesoscopic system under a periodic ac bias is investigated by combining the Floquet theorem and the nonequilibrium Green's function method. The band structure of the lead under ac bias is fully taken into account by using appropriate self-energies in an enlarged Floquet space. Both the retarded and lesser Green's functions are obtained in the Floquet basis to account for the interference and interaction effects. In addition to the external ac bias, the time-varying Coulomb interaction, which is treated at the self-consistent Hartree-Fock level, provides another internal ac field. The numerical results show that the time-varying Coulomb field yields decoherence and reduces the ringing behavior of the current response to a harmonic bias

Emission computerized-tomography and determination of local brain function

International Nuclear Information System (INIS)

Kuhl, D.E.; Alavi, A.; Reivich, M.; Edwards, R.Q.; Fenton, C.A.; Zimmerman, R.A.

1975-01-01

Methods for the three dimensional reconstruction of /sup 99m/Tc brain scans are described. The diagnostic advantages of computerized tomography in the localization of brain tumors and in measurements of local cerebral blood flow are discussed. (U.S.)

Cyclotron Production of Technetium-99m

Science.gov (United States)

Gagnon, Katherine M.

Technetium-99m (99mTc) has emerged as the most widely used radionuclide in medicine and is currently obtained from a 99Mo/ 99mTc generator system. At present, there are only a handful of ageing reactors worldwide capable of producing large quantities of the parent isotope, 99Mo, and owing to the ever growing shutdown periods for maintenance and repair of these ageing reactors, the reliable supply 99mTc has been compromised in recent years. With an interest in alternative strategies for producing this key medical isotope, this thesis focuses on several technical challenges related to the direct cyclotron production of 99mTc via the 100Mo(p,2n)99mTc reaction. In addition to evaluating the 100Mo(p,2n)99mTc and 100Mo(p,x)99Mo reactions, this work presented the first experimental evaluation of the 100Mo(p,2n) 99gTc excitation function in the range of 8-18 MeV. Thick target calculations suggested that large quantities of cyclotron-produced 99mTc may be possible. For example, a 6 hr irradiation at 500 μA with an energy window of 18→10 MeV is expected to yield 1.15 TBq of 99mTc. The level of coproduced 99gTc contaminant was found to be on par with the current 99Mo/99mTc generator standard eluted with a 24 hr frequency. Highly enriched 100Mo was required as the target material for 99mTc production and a process for recycling of this expensive material is presented. An 87% recovery yield is reported, including metallic target preparation, irradiation, 99mTc extraction, molybdate isolation, and finally hydrogen reduction to the metal. Further improvements are expected with additional optimization experiments. A method for forming structurally stable metallic molybdenum targets has also been developed. These targets are capable of withstanding more than a kilowatt of beam power and the reliable production and extraction of Curie quantities of 99mTc has been demonstrated. With the end-goal of using the cyclotron-produced 99mTc clinically, the quality of the cyclotron

Thyroidal radioisotope uptake in euthyroid cats : a comparison between 131I and 99MTcO4

Directory of Open Access Journals (Sweden)

N. Lambrechts

1997-07-01

Full Text Available Two thyroidal evaluation systems in euthyroid cats (n = 12 were compared. A single, confirmed hyperthyroid cat was included for interest. Firstly, thyroidal uptake of an intravenous bolus of approximately 111 MBq (3 mCi 99MTcO4- was estimated by using a scintillation camera and calculating the ratio of thyroid to salivary activities at 20 min and 4 h. Thyroid to salivary activity ratios were 1:1 at 20 min and 2:1 at 4 h. Two discrete areas of salivary uptake were identified, namely a parotid/mandibular complex and a more rostral buccal/sublingual complex. These results were compared to radioiodine uptake of an oral dose of approximately 0.925 MBq (25 mCi 131I using a standard thyroid uptake system, measured at 1, 2, 4, 6, 8, 10, 12, 24 and 48 h after administration. Mean radioiodine thyroidal uptake started at 33 % at 1 h, stabilised at 21 % between 4 and 24 h, and dropped to 18 % at 48 h. There was a significant correlation between the early thyroid:salivary ratio of the parotid/mandibular complex and the radioiodine uptake at 12 h.

Different Modes of Monitoring and Correction of Cardiac Function During Operations Under Extracorporeal Circulation

Directory of Open Access Journals (Sweden)

L. A. Krichevsky

2007-01-01

Full Text Available Objective: to comparatively evaluate the efficiency of intensive care measures chosen on the basis of traditional monitoring of central hemodynamics (CH or on that of the data of transesophageal echocardiography (TE echoCG.Materials and methods: 50 patients were examined at coronary bypass surgery under extracorporeal circulation. Under a prospective comparative analysis were two algorithms of treatment policy: maintenance of cardiac index, by using the maximum volemic load, or that of left ventricular systolic function under guidance of transesophageal echocardiography.Results: Significantly (p<0.05 larger doses of dopamine and/or dobutamine were required to maintain adequate left ventricular systolic function. However, this treatment policy showed much better (p<0.05 circulatory parameters in the postperfusion period. At the same time the duration of postoperative inotropic therapy in these patients proved to be significantly (p<0.05 less.Conclusion. The treatment policy based on the maintenance of left ventricular systolic function under guidance of TE echoCG leads to the shortest circulatory stabilization during myocardial revascularization. The application of a volemic load and the expectant use of inotropic drugs result in a longer restoration of operated heart function. 

Radiolabeling of VEGF165 with 99mTc to evaluate VEGFR expression in tumor angiogenesis.

Science.gov (United States)

Galli, Filippo; Artico, Marco; Taurone, Samanta; Manni, Isabella; Bianchi, Enrica; Piaggio, Giulia; Weintraub, Bruce D; Szkudlinski, Mariusz W; Agostinelli, Enzo; Dierckx, Rudi A J O; Signore, Alberto

2017-06-01

Angiogenesis is the main process responsible for tumor growth and metastatization. The principal effector of such mechanism is the vascular endothelial growth factor (VEGF) secreted by cancer cells and other components of tumor microenvironment. Radiolabeled VEGF analogues may provide a useful tool to noninvasively image tumor lesions and evaluate the efficacy of anti-angiogenic drugs that block the VEGFR pathway. Aim of the present study was to radiolabel the human VEGF165 analogue with 99mTechnetium (99mTc) and to evaluate the expression of VEGFR in both cancer and endothelial cells in the tumor microenvironment. 99mTc-VEGF showed in vitro binding to HUVEC cells and in vivo to xenograft tumors in mice (ARO, K1 and HT29). By comparing in vivo data with immunohistochemical analysis of excised tumors we found an inverse correlation between 99mTc-VEGF165 uptake and VEGF histologically detected, but a positive correlation with VEGF receptor expression (VEGFR1). Results of our studies indicate that endogenous VEGF production by cancer cells and other cells of tumor microenvironment should be taken in consideration when performing scintigraphy with radiolabeled VEGF, because of possible false negative results due to saturation of VEGFRs.

A parathyroid adenoma case study: Protocol review

Energy Technology Data Exchange (ETDEWEB)

Sorensen, B.J.; Chu, J.M.G. [Liverpool Hospital, NSW (Australia). Department of Nuclear Medicine and Clinical Ultrasound

1998-06-01

Full text: Technetium-99m ({sup 99m}Tc) Sestamibi as opposed to Thallous-201 Chloride and {sup 99m}Tc Sodium Pertechnetate subtraction, has become the radiopharmaceutical of choice for detection of parathyroid adenomas. A 17-year-old female patient presented to the department for a parathyroid {sup 99m}Tc Sestamibi scan to evaluate possible parathyroid adenoma/s. She was initially admitted with increasing serum Calcium levels, polyuria, abdominal pain and general malaise. The patient was injected with 900MBq of {sup 99m}Tc Sestamibi, and a pinhole dynamic at a distance of 10 cm from the neck was acquired followed by a 5-minute static image at 7 cm. Single Photon Emission Computed Tomography (SPECT) was then performed on a dual-head gamma camera followed by an anterior and posterior 10-minute static image. At 3 and 5 hours post injection the 10-minute static image was repeated. This study was reported as normal with uniform uptake and washout of the tracer over the 5-hour period. An ultrasound study was performed, and it showed a lesion believed to be a parathyroid adenoma measuring 2.2 x 0.8 x 0.4 cm in size in the right upper lobe of the thyroid. A subsequent thyroid scan was performed to confirm that it was non-functioning thyroid tissue. The patient was injected with 250MBq of {sup 99m}Tc Sodium Pertechnetate and scanned with a pinhole collimator at a distance of 7 cm. When the {sup 99m}Tc Sestamibi and {sup 99m}Tc Sodium Pertechnetate scan were viewed together, it was clear that there was excess {sup 99m}Tc Sestamibi distribution on the right upper lobe of the thyroid, which washed out over time. This corresponded to the ultrasound findings and was confirmed at surgery to be a parathyroid adenoma. A {sup 99m}Tc Sodium Pertechnetate scan and an ultrasound are now also routinely performed on patients presenting for {sup 99m}Tc Sestamibi parathyroid scans

Human monoclonal antibody 99mTc-88BV59: detection of colorectal cancer, recurrent or metastatic disease and immunogenicity assessment.

Science.gov (United States)

Krause, B J; Baum, R P; Staib-Sebler, E; Lorenz, M; Niesen, A; Hör, G

1997-01-01

This study presents immunoscintigraphic results in 24 patients suffering from primary colorectal cancer, recurrent or metastatic disease after the injection of 1197-1351 MBq technetium-99m labelled totally human monoclonal antibody 88BV59. Labelling efficacy of 99mTc-88BV59 ranged from 97% to 99%. Immunoscintigraphy was performed 18-20 h after injection. Scintigraphic findings were compared with those of computed tomography (CT). Patients underwent surgery in order to evaluate immunoscintigraphic findings histologically. Sera of the patients (before injection and 1 and 3 months post infusion) were analysed for the presence of human anti-human antibodies (HAHA). None of the patients showed a HAHA response as assessed by a solid-phase ELISA assay. The antibody scan detected about 25% more lesions than CT. In the detection of extrahepatic disease, the sensitivity of the antibody scan proved to be 68%, whereas the sensitivity of CT was 41%.

Euthyroid goitre with and without functional autonomy: A comparison; Jodmangelstruma mit und ohne funktionelle Autonomie in der euthyreoten Phase: Ein Vergleich

Energy Technology Data Exchange (ETDEWEB)

Hillenhinrichs, H.; Emrich, D. [Goettingen Univ. (Germany). Abt. fuer Nuklearmedizin

1998-05-01

Analysis of functional autonomy in euthyroid goitre. Methods: In an area of moderate iodine deficiency 163 goitrous patients without and 179 with functional autonomy all clinically euthyroid were compared by sex, age, signs and symptoms, sonographic results, qualitative and quantitative scintigraphy without and with suppression, TRH test, hormone concentrations and iodine excretion in the urine. Results: Age, signs and symptoms, thyroid volume and structure did not contribute sufficiently to diagnosis. To detect functional autonomy quantitative scintigraphy under suppression was superior to the TRH test. Increased hormone concentrations were observed in 15% of patients with functional autonomy. A global {sup 99m}Tc thyroid uptake of {>=}3% under suppression indicates a higher risk of spontaneous hyperthyroidism. It was present in 20% of patients with functional autonomy. Conclusion: to diagnose and treat adequately functional autonomy in euthyroid goitre quantitative scintigraphy, determination of TSH and hormone concentrations are inevitable. (orig.) [Deutsch] Analyse der funktionellen Autonomie in der euthyreoten Phase. Methoden: Es wurden 163 klinisch euthyreote Patienten mit Jodmangelstruma ohne und 179 mit funktioneller Autonomie anhand von Geschlechtsverhaeltnis, Lebensalter, Beschwerden, Symptomen, sonographischem Befund, qualitativer und quantitativer Szintigraphie ohne und mit Suppression, TRH-Test, Hormonkonzentrationen und Jodausscheidung im Urin verglichen. Ergebnisse: Lebensalter, Beschwerden und Symptome, Schilddruesenvolumen und Echomuster lieferten keinen ausreichend sicheren Beitrag zur Diagnose. Die quantitative Szintigraphie war dem TRH-Test ueberlegen. Erhoehte Hormonkonzentrationen ergaben sich bei 15% der Patienten mit funktioneller Autonomie. Als Grenzwert fuer ein erhoehtes spontanes Hyperthyreoserisiko wurde eine globale thyreoidale {sup 99m}Tc-Aufnahme unter Suppression von {>=}3% ermittelt, die in 20% der Patienten mit funktioneller

Differential diagnosis of MRI detected intra cranial space occupying lesions (ICSOLS)-role of 99MTC tetrofosmin cerebral spect

International Nuclear Information System (INIS)

Padmal, S.; Sundaram, P.S.; Kumar, S.

2004-01-01

Discriminating the correct etiology of Intra Cranial Space Occupying Lesions (ICSOLs) detected by MRI is of paramount importance in deciding the right therapeutic approach. Functional imaging like 99m Tc Tetrofosmin cerebral SPECT (C SPECT) can be used to differentiate malignant from other benign cerebral pathologies. Objective: Our aim was to assess the efficacy of C SPECT in differentiating various etiologies (i.e. Infective / Inflammatory, Neoplastic and Post Radiotherapy changes) of MRI detected ICSOLs. We also aimed to assess the incremental value of quantitative uptake ratios in identifying the exact nature of ICSOLs. Method: 26 Patients (M:F=20:6), age range 28-76 yrs, mean 42±7 yrs were evaluated by 99mTc Tetrofosmin cerebral SPECT. 14/26 patients were HIV positive cases while remaining 12 were treated patients of intracerebral malignancies. All these patients had one or more discrete MRI detected ICSOLs. 6/4 patients with HIV and 4/12 patients in the non HIV group showed more than 1 discrete ICSOLs. 20 mci of 99mTc Tetrofosmin was injected IV .15 min (early) and 2 hrs (delayed) post injection C SPECT images were acquired on a dual head variable angle Gamma camera. After reconstruction, transverse, coronal and sagittal images were co- registered with DICOM online available MRI images using aco- registration software. Focal Tetrofosmin uptake in MRI detected ICSOL was interpreted as abnormal. Tetrofosmin uptake index (Ix) was calculated in early and delayed images as ratio of counts in lesion to that of contra lateral region. A value of more than 1.3 was considered to be abnormal. Persistent Ix of more than 1.3 in initial and delayed images were considered to be malignant while Ix of more or less than 1.3 in initial but less than 1.3 in delayed images was considered to be benign in both groups. Results: In HIV group (14 pts), 4 patients showed an Ix of less than 1.3 in both early and delayed images and 7 patients showed an Ix of more than 1.3 in early but

Dimer of the peptide cycle (Ar-Gly-Asp-D-Phe-Lys) radiolabeled with {sup 99m}Tc for the integrin s over-expression image: formulation, biokinetics and dosimetry; Dimero del peptido ciclo(Arg-Gly-Asp-D-Phe-Lys) radiomarcado con {sup 99m}Tc para la imagen de sobre-expresion de integrinas: formulacion, biocinetica y dosimetria

Energy Technology Data Exchange (ETDEWEB)

Ortiz A, Z.

2013-07-01

In breast cancer, α(v)β(3) and/or α(v)β(5) integrin s are over-expressed in both endothelial and tumour cells. Radiolabeled peptides based on the RGD (Arg-Gly-Asp) sequence are radiopharmaceuticals with high affinity and selectivity for those integrin s. The RGD-dimer peptide (E-[c(RGDfK)]{sub 2}) radiolabeled with {sup 99m}Tc has been reported as a radiopharmaceutical with 10-fold higher affinity for the α(v)β(3) integrin as compared to the RGD-monomer. EDDA (Ethylenediamine-N,N-diacetic acid) is a hydrophilic molecule that may favours renal excretion when used as coligand in the {sup 99m}Tc labelling of HYNIC-peptides and can easily be formulated in a lyophilized kit. Aim: Establish a biokinetic model for {sup 99m}Tc-EDDA/HYNIC-E-[c(RGDfK)]{sub 2} prepared from lyophilized kits and evaluate the dosimetry as breast cancer imaging agent. Methods: {sup 99m}Tc labelling was performed by addition of sodium pertechnetate solution and 0.2 M phosphate buffer ph 7.0 to a lyophilized formulation containing E-[c(RGDfK)]{sub 2}, EDDA, tricine, mannitol and stannous chloride. Radiochemical purity was evaluated by reversed phase HPLC and ITLC-SG analyses. Stability studies in human serum were carried out by size-exclusion HPLC. In-vitro cell uptake was tested using breast cancer cells (MCF7, T47D and MDA-MB-231) with blocked and non-blocked receptors. Biodistribution and tumour uptake were determined in MCF7 tumour-bearing nude mice with blocked and non-blocked receptors, and images were obtained using a micro-SPECT/CT. Whole-body images from seven healthy women were acquired at 1, 3, 6 and 24 h after {sup 99m}Tc-EDDA/HYNIC-E-[c(RGDfK)]{sub 2} administration obtained with radiochemical purities of >94 %. Regions of interest (ROIs) were drawn around source organs on each time frame. Each ROI was converted to activity using the conjugate view counting method. The image sequence was used to extrapolate {sup 99m}Tc-EDDA/HYNIC-E-[c(RGDfK)]{sub 2} time-activity curves in each

TSH alone is not sufficient to exclude all patients with a functioning thyroid nodule from undergoing testing to exclude thyroid cancer

Energy Technology Data Exchange (ETDEWEB)

Hurtado-Lopez, Luis-Mauricio; Monroy-Lozano, Blanca-Estela [General Hospital of Mexico, Mexico City (Mexico); Martinez-Duncker, Carlos [Hospital Infantil de Mexico Federico Gomez, Medicina Nuclear Molecular, Mexico City, DF (Mexico)

2008-06-15

The purpose of the study was to analyze whether the thyroid-stimulating hormone (TSH) alone avoids tests to exclude malignancy in all patients with functional thyroid nodules (FTN). Sixty-nine patients with FTN on {sup 99m}Tc scintigraphy, radioiodine uptake test (RIU), {sup 99m}Tc thyroid uptake, TSH assay, T3, and T4 obtained within 48 h were retrospectively identified out of 2,356 thyroid scans performed from January 2000 to April 2007. FTNs were classified as causing total, partial, or no inhibition of the thyroid as group 1, 2, or 3, respectively. TSH was subnormal in 21 of 69 (30.43%) patients. In group 1 (N = 23, 33.3%), TSH was subnormal, normal, and high in eight, nine, and six patients; in group 2 (N = 17, 24.6%), TSH was subnormal, normal, and high in four, six, and seven patients, and in group 3 (N = 29, 42%), TSH was subnormal, normal, and high in 9, 13, and 7 patients, respectively. TSH was significantly lower in group 1. In T3, T4, {sup 99m}Tc thyroid uptake, and RIU, there were no differences between the three groups. Only 30.43% of patients had subnormal TSH. TSH alone cannot avoid tests to exclude malignancy in all patients with FTN. FTN existence can only be accurately assessed by thyroid scintigraphy. The current incidence of FTN may be unknown because scintigraphy is not routinely performed in all patients with thyroid nodules. Thyroid scintigraphy of patients with high TSH can detect diseases such as Hashimoto's thyroiditis and identify patients with FTN in whom no further diagnostic procedures would be needed in patients with normal TSH levels with nondiagnostic fine-needle aspiration results. (orig.)

The carbon emissions generated in all that we consume

International Nuclear Information System (INIS)

2006-01-01

perspectives. This reallocation shows that: The emissions from Electricity Production can be completely reallocated to the end user categories of that electricity. For example, the Hotels, Catering and Pubs category now includes the emissions from the generation of the electricity used to heat hotels and refrigerate and cook restaurant food; and The supply chains in the Hotels, Catering and Pubs category now have the largest carbon emissions at 8.3 MtC. This is followed by Motor Vehicle Production and Health and Veterinary Services, at 7.1 MtC and 6.1 MtC respectively. Finally, the consumption categories can be summed together into high-level consumer needs. In these perspectives, emissions from domestic electricity, domestic fuel use and domestic private transport fuel use are added in. Aviation fuel emissions are still excluded. This perspective shows: The supply chains associated with Recreation and Leisure have the highest emissions at 31.6 MtC. Just under half of this is transport emissions; This is followed by Space Heating of buildings with 24.0 MtC and Food and Catering at 22.4 MtC. The majority of Space Heating emissions occur directly in the building, whereas two thirds of carbon emissions from Food and Catering are embodied in the products consumed; and in total, UK consumers use products and services with a combined carbon footprint of 176.4 MtC. This is 11.7 MtC greater than the emissions from all UK production. This means that the UK is a net importer of carbon intensive products and services from abroad. (UK)

Fuzzy logic and image processing techniques for the interpretation of seismic data

International Nuclear Information System (INIS)

Orozco-del-Castillo, M G; Ortiz-Alemán, C; Rodríguez-Castellanos, A; Urrutia-Fucugauchi, J

2011-01-01

Since interpretation of seismic data is usually a tedious and repetitive task, the ability to do so automatically or semi-automatically has become an important objective of recent research. We believe that the vagueness and uncertainty in the interpretation process makes fuzzy logic an appropriate tool to deal with seismic data. In this work we developed a semi-automated fuzzy inference system to detect the internal architecture of a mass transport complex (MTC) in seismic images. We propose that the observed characteristics of a MTC can be expressed as fuzzy if-then rules consisting of linguistic values associated with fuzzy membership functions. The constructions of the fuzzy inference system and various image processing techniques are presented. We conclude that this is a well-suited problem for fuzzy logic since the application of the proposed methodology yields a semi-automatically interpreted MTC which closely resembles the MTC from expert manual interpretation

Symbiotic Dinoflagellate Functional Diversity Mediates Coral Survival under Ecological Crisis.

Science.gov (United States)

Suggett, David J; Warner, Mark E; Leggat, William

2017-10-01

Coral reefs have entered an era of 'ecological crisis' as climate change drives catastrophic reef loss worldwide. Coral growth and stress susceptibility are regulated by their endosymbiotic dinoflagellates (genus Symbiodinium). The phylogenetic diversity of Symbiodinium frequently corresponds to patterns of coral health and survival, but knowledge of functional diversity is ultimately necessary to reconcile broader ecological success over space and time. We explore here functional traits underpinning the complex biology of Symbiodinium that spans free-living algae to coral endosymbionts. In doing so we propose a mechanistic framework integrating the primary traits of resource acquisition and utilisation as a means to explain Symbiodinium functional diversity and to resolve the role of Symbiodinium in driving the stability of coral reefs under an uncertain future. Copyright © 2017 Elsevier Ltd. All rights reserved.

Cine-oesophago-gastroscintigraphy: assessment of digestive function in paediatrics

Energy Technology Data Exchange (ETDEWEB)

Guillet, J. (Hopital Pellegrin, 33 - Bordeaux (France))

1984-05-15

Cine-oesophago-gastroscintigraphy (COGS) can assess structure and function of the oesophagogastrointestinal tract. With this non-invasive method, the dosimetry is very low and quantification is easy. Milk or water labelled by sup(99m)Tc sulfocolloids are drunk by the patient. The transit is continuously monitored by a gamma camera and a computer. The esophageal transit time is useful in studying impairment of peristaltic motion. Fistula, diverticula and stenosis are easily detected. The sensitivity of this technique for the search of gastroesophageal reflux is as great as pH-metry. The quantification is of great interest to assess the severity of the reflux and to measure treatment efficacity. Slow rates of gastric emptying are associated with some of the reflux, and pyloric stenosis. Pulmonary contamination can be discovered in patients with gastro oesophageal reflux.

Functional mapping imprinted quantitative trait loci underlying developmental characteristics

Directory of Open Access Journals (Sweden)

Li Gengxin

2008-03-01

Full Text Available Abstract Background Genomic imprinting, a phenomenon referring to nonequivalent expression of alleles depending on their parental origins, has been widely observed in nature. It has been shown recently that the epigenetic modification of an imprinted gene can be detected through a genetic mapping approach. Such an approach is developed based on traditional quantitative trait loci (QTL mapping focusing on single trait analysis. Recent studies have shown that most imprinted genes in mammals play an important role in controlling embryonic growth and post-natal development. For a developmental character such as growth, current approach is less efficient in dissecting the dynamic genetic effect of imprinted genes during individual ontology. Results Functional mapping has been emerging as a powerful framework for mapping quantitative trait loci underlying complex traits showing developmental characteristics. To understand the genetic architecture of dynamic imprinted traits, we propose a mapping strategy by integrating the functional mapping approach with genomic imprinting. We demonstrate the approach through mapping imprinted QTL controlling growth trajectories in an inbred F2 population. The statistical behavior of the approach is shown through simulation studies, in which the parameters can be estimated with reasonable precision under different simulation scenarios. The utility of the approach is illustrated through real data analysis in an F2 family derived from LG/J and SM/J mouse stains. Three maternally imprinted QTLs are identified as regulating the growth trajectory of mouse body weight. Conclusion The functional iQTL mapping approach developed here provides a quantitative and testable framework for assessing the interplay between imprinted genes and a developmental process, and will have important implications for elucidating the genetic architecture of imprinted traits.

The Sphagnum microbiome supports bog ecosystem functioning under extreme conditions.

Science.gov (United States)

Bragina, Anastasia; Oberauner-Wappis, Lisa; Zachow, Christin; Halwachs, Bettina; Thallinger, Gerhard G; Müller, Henry; Berg, Gabriele

2014-09-01

Sphagnum-dominated bogs represent a unique yet widely distributed type of terrestrial ecosystem and strongly contribute to global biosphere functioning. Sphagnum is colonized by highly diverse microbial communities, but less is known about their function. We identified a high functional diversity within the Sphagnum microbiome applying an Illumina-based metagenomic approach followed by de novo assembly and MG-RAST annotation. An interenvironmental comparison revealed that the Sphagnum microbiome harbours specific genetic features that distinguish it significantly from microbiomes of higher plants and peat soils. The differential traits especially support ecosystem functioning by a symbiotic lifestyle under poikilohydric and ombrotrophic conditions. To realise a plasticity-stability balance, we found abundant subsystems responsible to cope with oxidative and drought stresses, to exchange (mobile) genetic elements, and genes that encode for resistance to detrimental environmental factors, repair and self-controlling mechanisms. Multiple microbe-microbe and plant-microbe interactions were also found to play a crucial role as indicated by diverse genes necessary for biofilm formation, interaction via quorum sensing and nutrient exchange. A high proportion of genes involved in nitrogen cycle and recycling of organic material supported the role of bacteria for nutrient supply. 16S rDNA analysis indicated a higher structural diversity than that which had been previously detected using PCR-dependent techniques. Altogether, the diverse Sphagnum microbiome has the ability to support the life of the host plant and the entire ecosystem under changing environmental conditions. Beyond this, the moss microbiome presents a promising bio-resource for environmental biotechnology - with respect to novel enzymes or stress-protecting bacteria. © 2014 John Wiley & Sons Ltd.

Thyrotoxic Graves' disease with normal thyroidal technetium-99m pertechnetate uptake

Energy Technology Data Exchange (ETDEWEB)

Ikekubo, Katsuji; Hino, Megumu; Ito, Hidetomi; Koh, Toshikiyo; Ishihara, Takashi; Kurahachi, Hiroyuki (Kobe City General Hospital (Japan)); Kasagi, Kanji; Hidaka, Akinari; Mori, Toru

1990-07-01

We saw 24 thyrotoxic Graves' patients with normal thyroidal uptake of technetium-99m pertechnetate ({sup 99m}Tc) out of 201 untreated thyrotoxic Graves' patients seen over 4 years. The clinical and laboratory findings for these patients were studied and analyzed. Thyroid uptake and scintigraphic examinations by means of {sup 99m}Tc, TBII and TSab activity measurement clearly distinguished these patients from other thyrotoxic disorders (destruction-induced thyrotoxicosis and autonomously functioning thyroid lesions). Different from other disorders, these patients had not lower but normal thyroid uptake and also showed diffuse and discrete trapping into the enlarged glands. These patients had significantly smaller goiters, a lower serum thyroid hormone level, and lower TBII and TSab activity, when compared with other high {sup 99m}Tc uptake groups with Graves' disease, and their condition could be easily controlled with small amounts of antithyroid drugs. Our study indicates that thyrotoxic Graves' disease with normal {sup 99m}Tc uptake exists and {sup 99m}Tc uptake study and TBII activity measurement is very useful for the diagnosis. The normal {sup 99m}Tc uptake thyrotoxic Graves' patient might be early stage patients with general Graves' disease and their early discrimination from general Graves' patients is very advantageous for treatment and prognosis. (author).

Radioisotope visualization of hepatopancreatic region in patients with mechanical jaundice. [/sup 131/I, /sup 99m/Tc, and /sup 75/Se tracer techniques

Energy Technology Data Exchange (ETDEWEB)

Kasatkin, Yu N; Rozanov, I B; Mironov, S P; Egorova, A I; Diasamidze, Z I

1976-01-01

Differential diagnosis of jaundice presents one of the most difficult problems of clinical hepatology. The use of scintillation ..gamma..-chamber and radioactive indicator bengal rose, labeled with /sup 131/I gives the possibility of visualizing the bile secretion and biligenic processes. A total of 82 patients with mechanical jaundice of different etiology have been observed. One of the most important diagnostical findings in mechanical jaundices is visualization of the kidneys image with retention of the stain in the liver. An additional study of the liver with colloid /sup 99m/Tc and the pancreas with /sup 75/Se-methionine taking into account clinical data makes it possible to solve the problem of differential and in separate cases topical diagnosis of the cause of obstruction in the biliary tract.

Determination of work function of graphene under a metal electrode and its role in contact resistance.

Science.gov (United States)

Song, Seung Min; Park, Jong Kyung; Sul, One Jae; Cho, Byung Jin

2012-08-08

Although the work function of graphene under a given metal electrode is critical information for the realization of high-performance graphene-based electronic devices, relatively little relevant research has been carried out to date. In this work, the work function values of graphene under various metals are accurately measured for the first time through a detailed analysis of the capacitance-voltage (C-V) characteristics of a metal-graphene-oxide-semiconductor (MGOS) capacitor structure. In contrast to the high work function of exposed graphene of 4.89-5.16 eV, the work function of graphene under a metal electrode varies depending on the metal species. With a Cr/Au or Ni contact, the work function of graphene is pinned to that of the contacted metal, whereas with a Pd or Au contact the work function assumes a value of ∼4.62 eV regardless of the work function of the contact metal. A study of the gate voltage dependence on the contact resistance shows that the latter case provides lower contact resistance.

Serum level of vascular endothelial growth factor is influenced by erythropoietin treatment in peritoneal dialysis patients. (Grupo de Estudios Peritoneales de Madrid).

Science.gov (United States)

del Peso, G; Selgas, R; Bajo, M A; Fernández de Castro, M; Aguilera, A; Cirugeda, A; Jiménez, C

2000-01-01

Some patients on long-term peritoneal dialysis (PD) develop a hyperpermeability state, owing to peritoneal neoangiogenesis. Vascular endothelial growth factor (VEGF), a potent mitogen for endothelial cells, has been implicated in most diseases characterized by microvascular neoformation. Erythropoietin (EPO) is able to induce endothelial proliferation in vitro. Our aim was to elucidate whether VEGF serum levels are influenced by EPO treatment, and whether VEGF serum level maintains a relationship with peritoneal transport data. We analyzed serum levels of VEGF in 35 PD patients (18 males, 17 females). Mean age was 58 years, with a mean time on PD of 98 +/- 75 months. Of the 35 patients, 19 were on automated peritoneal dialysis, and 16 were on continuous ambulatory peritoneal dialysis. Seven patients had diabetes. Peritoneal transport parameters were: urea mass transfer coefficient (MTC), 19.5 +/- 6.6 mL/min; creatinine MTC, 9.9 +/- 4.7 mL/min; net ultrafiltration, 491 +/- 166 mL per 4-hour dwell. Twenty seven patients were under therapy with recombinant human erythropoietin (rHuEPO). Mean serum VEGF levels were 347 +/- 203 pg/mL (range 66-857 pg/mL), with most patients in the normal range (60-700 pg/mL). VEGF levels did not correlate with age, sex, primary renal disease, diabetes, type of PD, time on PD, peritonitis, and cumulative glucose load. We found no correlation with urea MTC, creatinine MTC, ultrafiltration rate, or protein effluent levels. However, a significant negative correlation with residual renal function was seen (r = -0.39, p < 0.05). Patients treated with rHuEPO showed significantly higher serum levels of VEGF than non treated patients (375 +/- 220 pg/mL vs 251 +/- 75 pg/mL, p < 0.05), although they had similar residual renal function. We conclude that increased serum VEGF levels are associated with EPO treatment. Consequently, VEGF might have a role in the EPO effects found in PD patients. Whether both agents are related to peritoneal

Stress analysis on the valve of the rotating shield, coupled with fuel element loading-unloading machine in a PWR pressure vessel

International Nuclear Information System (INIS)

Albuquerque, L.B. de; Jesus Miranda, C.A. de.

1992-01-01

A finite element static analysis was performed with the valve of the Rotating Shield (RS) which is coupled with the Fuel. Element Loading-Unloading Machine under OBE earthquake. The applied leads were obtained from a previous seismic analysis with the response spectrum method of the MTC under OBE load. A 3-D model with shell elements was developed for the valve body and for a part of the RS. The ANSYS program, version 4.4 A, was used. The two main scopes of this work were to verify the valve stresses and the functionality of its moving parts during the earthquake. (author)

Prognosis and submandibular function of Bell's palsy as evaluated using submandibular scan with sup(99m)TC

International Nuclear Information System (INIS)

Ino, Chiyonori; Yamashita, Toshio; Tomoda, Koichi; Kumazawa, Tadami

1983-01-01

The function of the submandibular gland of 32 patients with Bell's palsy was examined with radio-isotope (RI) scincigraphy using sup(99m)Tc-pertechnetate; and the relationship between the function of the gland and the prognosis of palsy was discussed. Uptake and secretion of the RI in the glands on both sides were measured twice, the first time within 10 days of the onset of palsy, and the second time 3 to 4 weeks after the onset. The results were as follows: 1) In the case in which the function of the affected side was higher than that of normal side, the prognosis was good. 2) In the case in which the function of the affected side was lower than the normal in the first test but improved in the second test, the prognosis was also good. 3) In the case in which the function of the affected side was lower than the normal in the first test, and worsened in the second test, the prognosis was poor. In conclusion, the application of RI scincigraphy was thought to be very useful for early diagnosis of Bell's palsy. (author)

Characterization of functional biopolymers under various external stimuli

Energy Technology Data Exchange (ETDEWEB)

Maleki, Atoosa

2008-07-01

Polymers are large molecules composed of repeating structural units connected by covalent chemical bonds. Biopolymers are a class of polymers produced by living organisms, which exhibit both biocompatible and biodegradable properties. The behavior of a biopolymer in solution is strongly dependent on the chemical and physical structure of the polymer chain, as well as external environmental conditions. To improve biopolymers in the direction of higher performance and better functionality, understanding of their physicochemical behavior and their response to external stimuli are of great importance. Rheology, rheo-small angle light scattering, dynamic light scattering, small angle neutron scattering, and asymmetric flow field-flow fractionation were utilized in this thesis to investigate the properties of hydroxyethyl cellulose and its hydrophobically modified analogue, as well as dextran, hyaluronan, and mucin under different conditions such as temperature, solvent, mechanical stress and strain, and radiation. Different novel hydrogels were prepared by using various chemical cross-linking agents. Specific features of these macromolecules provide them to be used as 'functional' materials, e.g., sensors, actuators, personal care products, enhanced oil recovery, and controlled drug delivery systems (author)

The cine-oesophago-gastroscintigraphy: assessment of digestive function in paediatrics

International Nuclear Information System (INIS)

Guillet, J.

1984-01-01

Cine-oesophago-gastroscintigraphy (COGS) can assess structure and function of the oesophagogastrointestinal tract. With this non-invasive method, the dosimetry is very low and quantification is easy. Milk or water labelled by sup(99m)Tc sulfocolloids are drunk by the patient. The transit is continuously monitored by a gamma camera and a computer. The esophageal transit time is usefull in studying impairment of peristaltic motion. Fistula, diverticula and stenosis are easily detected. The sensitivity of this technique for the search of gastroesophageal reflux is as great as pHmetry. The quantification is of great interest to assess the severity of the reflux and to measure treatment efficacity. Slow rates of gastric emptying are associated with some of the reflux, and pyloric stenosis. Pulmonary contamination can be discovered in patients with gastro oesophageal reflux [fr

Radio localization of inflammatory bowel diseases using 99mtc-colloidal bismuth subcitrate

International Nuclear Information System (INIS)

Pimentel, G.; Miranda, M.; Sanchez, I.; Oliva, J.; Velasco, M.; Paniagua, M.; Pinol, F.; Riano, A.; Paneque, A.; Castillo, J.; Leyvad, R.

2006-01-01

A correct diagnosis and adequate assessment of disease activity is crucial in the management and surveillance of inflammatory bowel diseases (IBDs). However, in certain occasions the obtained results by means of traditional techniques are not correlated specifically with the inflammatory state of the mucosal wall, mainly in case of the small bowel, due to its no accessibility. This investigation constituted a multi centric clinical trial phase I-II. Forty-four patients were prospectively evaluated with the objective of determining the validity of the scintigraphy with 99mTc-Sn-CBS for the diagnosis of illnesses with ulcerations of the intestinal tube. Of the evaluated patients, 20 presented Cohns Disease (in 1 of them the scintigraphy was not useful), Idiopathic Ulcerative Colitis, 3 gastric ulcer and 20 patients were seemingly healthy, conforming these last ones the group control. Five hundred mgs of CBS were labelled with 370 MBq (10 mCi) of 99mTc and administered by oral via as unique dose. The diagnostic test had duration of three days for each patient: first day for the patient's preparation with soft diet and 20% mannitol and two days for the image registrations. The images were carried out at 2, 4, 6 and 24 hours post administered the product. All procedures were performed by experienced examiners, who were blinded to the clinical data and other results. It was determined the sensibility and specificity of this technique taking like reference test, the colonoscopy, gastroduodenoscopy, intestinal transit and/or biopsy, achieving a sensibility of 91,3% and a specificity of 90%. During the whole study an adverse event appeared, which had not very probable causation according to the scale of Karch and Lasagna. It can be concluded that the diagnostic criteria established in this study can be useful for the evaluation of inflammatory bowel diseases by scintigraphy with 99mTc-Sn-CBS. (Author)

Influence of some drugs, used in coronary artery disease on in vitro labelling red blood cells with technetium {sup 99m}Tc; Wplyw wybranych lekow, stosowanych w chorobie niedokrwiennej serca na wiazanie technetu {sup 99m}Tc przez erytrocyty in vitro

Energy Technology Data Exchange (ETDEWEB)

Poniatowicz-Frasunek, E. [Katedra i Zaklad Medycyny Nuklearnej, Akademia Medyczna, Lublin (Poland)

1997-12-31

In some patients investigated by radionuclide ventriculography poor labeling efficiency of red blood cells with technetium {sup 99m}Tc is observed. Among possible mechanisms responsible for this phenomenon, the pharmacological treatment applied to the patients should be taken into consideration. The aim of the study was to define the effect of selected drugs used in CAD on technetium binding efficiency by erythrocytes in vitro. Blood samples were obtained from 40 normal individuals receiving no medication. The effect of the following drugs were examined: Aerosonit, Isoptin, Bemecor, Dopegyt, Enarenal, Binazin, Furosemid, Aspirin, Vitamin E and Propranolol. Only Enarenal and Vitamin E proved to have no effect on technetium binding efficiency. The most expressed reduction was observed in experiments with Aerosonit, Furosemid and Propranolol and the smallest changes were found in blood samples with Bemecor, Binazin and Aspirin. The results of the study suggest that pharmacological treatment may influence the quality of scintigraphic images obtained with radioisotope ventriculography. For that reason the medicines applied to the patients should be as much as possible reduced or withdrawn for at least several days before examination. (author) 23 refs, 4 figs, 2 tabs

A Case of with Transient splenic Hot Uptake on {sup 99m}Tc-Methylene Diphosphonate (MDP) Bone Scan Following Blunt Abodominal Trauma with Underlying Liver Cirrhosis

Energy Technology Data Exchange (ETDEWEB)

Won, Jong Hyeon; Kim, Jae Myung; Kim, Jung Han; Choo, Gil Yeon; Park, Seok Oh; Sung, Sang Kyu; Choi, Dae Seob; Kim, Chin Seung [Sung Ae General Hospital, Seoul (Korea, Republic of)

1993-07-15

We report a case of 33-year-old man with a transient splenic uptake who had traumatic multiple rib fractures and hemoperitoneum combined with underlying liver cirrhosis, liver cirrhosis with liver bed laceration and splenomegaly without any other demonstrable splenic lesion due to traffic accident was found by abdominal ultrasound and surgery. Incidentally, {sup 99m}Tc-MDP Bone scan showed whole prominent splenic uptake, spleen was also visible on {sup 99m}Tc Tin colloid liver scan. We suggest the splenic uptake of the radionuclide temporary splenic infarct to the transient total splenic infarction or unknown traumatic effect.

[Importance of parathyroid SPECT and 99mTc scintigraphy, and of clinical, laboratorial, ultrasonographic and citologic correlation in the pre-operative localization of the parathyroid adenoma - pictorial assay].

Science.gov (United States)

Oliveira, Marco Antônio Condé de; Maeda, Sérgio Setsuo; Dreyer, Patrícia; Lobo, Alberto; Andrade, Victor Piana de; Hoff, Ana O; Biscolla, Rosa Paula Mello; Smanio, Paola; Brandão, Cynthia M A; Vieira, José G

2010-06-01

In patients with primary hyperparathyroidism, candidates for surgical intervention, the parathyroid pre-operative localization is of fundamental importance in planning the appropriate surgical approach. The additional acquisition of SPECT and Technetium-99m images, during parathyroid scintigraphy with Sestamibi, is not common practice. Usually, only planar image acquisition, 15 minutes prior and 2 hours after radiopharmaceutical administration, is performed. In our experience, the complete protocol in parathyroid scintigraphy increases the accuracy of pre-operative parathyroid localization. The complete utilization of all available nuclear medicine methods (SPECT e 99mTc) and image interpretation in a multidisciplinary context can improve the accuracy of parathyroid scintigraphy.

Human monoclonal antibody {sup 99m}Tc-88BV59: detection of colorectal cancer, recurrent or metastatic disease and immunogenicity assessment

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Krause, B.J. [Department of Nuclear Medicine, Johann Wolfgang Goethe University Medical Center, Frankfurt/Main (Germany); Baum, R.P. [Department of Nuclear Medicine, Johann Wolfgang Goethe University Medical Center, Frankfurt/Main (Germany); Staib-Sebler, E. [Department of General and Abdominal Surgery, Johann Wolfgang Goethe University Medical Center, Frankfurt/Main (Germany); Lorenz, M. [Department of General and Abdominal Surgery, Johann Wolfgang Goethe University Medical Center, Frankfurt/Main (Germany); Niesen, A. [Department of Nuclear Medicine, Johann Wolfgang Goethe University Medical Center, Frankfurt/Main (Germany); Hoer, G. [Department of Nuclear Medicine, Johann Wolfgang Goethe University Medical Center, Frankfurt/Main (Germany)

1997-01-01

This study presents immunoscintigraphic results in 24 patients suffering from primary colorectal cancer, recurrent or metastatic disease after the injection of 1197-1351 MBq technetium-99m labelled totally human monoclonal antibody 88BV59. Labelling efficacy of {sup 99m}Tc-88BV59 ranged from 97% to 99%. Immunoscintigraphy was performed 18-20 h after injection. Scintigraphic findings were compared with those of computed tomography (CT). Patients underwent surgery in order to evaluate immunoscintigraphic findings histologically. Sera of the patients (before injection and 1 and 3 months post infusion) were analysed for the presence of human anti-human antibodies (HAHA). None of the patients showed a HAHA response as assessed by a solid-phase ELISA assay. The antibody scan detected about 25% more lesions than CT. In the detection of extrahepatic disease, the sensitivity of the antibody scan proved to be 68%, whereas the sensitivity of CT was 41%. (orig.). With 3 figs., 1 tab.

Clinical comparison of 99mTc exametazime and 123I Ioflupane SPECT in patients with chronic mild traumatic brain injury.

Directory of Open Access Journals (Sweden)

Andrew B Newberg

Full Text Available BACKGROUND: This study evaluated the clinical interpretations of single photon emission computed tomography (SPECT using a cerebral blood flow and a dopamine transporter tracer in patients with chronic mild traumatic brain injury (TBI. The goal was to determine how these two different scan might be used and compared to each other in this patient population. METHODS AND FINDINGS: Twenty-five patients with persistent symptoms after a mild TBI underwent SPECT with both (99mTc exametazime to measure cerebral blood flow (CBF and (123I ioflupane to measure dopamine transporter (DAT binding. The scans were interpreted by two expert readers blinded to any case information and were assessed for abnormal findings in comparison to 10 controls for each type of scan. Qualitative CBF scores for each cortical and subcortical region along with DAT binding scores for the striatum were compared to each other across subjects and to controls. In addition, symptoms were compared to brain scan findings. TBI patients had an average of 6 brain regions with abnormal perfusion compared to controls who had an average of 2 abnormal regions (p<0.001. Patient with headaches had lower CBF in the right frontal lobe, and higher CBF in the left parietal lobe compared to patients without headaches. Lower CBF in the right temporal lobe correlated with poorer reported physical health. Higher DAT binding was associated with more depressive symptoms and overall poorer reported mental health. There was no clear association between CBF and DAT binding in these patients. CONCLUSIONS: Overall, both scans detected abnormalities in brain function, but appear to reflect different types of physiological processes associated with chronic mild TBI symptoms. Both types of scans might have distinct uses in the evaluation of chronic TBI patients depending on the clinical scenario.

Emotional-volitional components of operator reliability. [sensorimotor function testing under stress

Science.gov (United States)

Mileryan, Y. A.

1975-01-01

Sensorimotor function testing in a tracking task under stressfull working conditions established a psychological characterization for a successful aviation pilot: Motivation significantly increased the reliability and effectiveness of their work. Their acitivities were aimed at suppressing weariness and the feeling of fear caused by the stress factors; they showed patience, endurance, persistence, and a capacity for lengthy volitional efforts.

Biodistribution dosimetric study of radiopharmaceutical {sup 99mT}c Ixolaris in mice for melanoma diagnosis by molecular image and translational model for human beings; Estudo dosimetrico da biodistribuicao do radiofarmaco Ixolaris-{sup 99m}Tc em camundongos para diagnostico de melanoma atraves de imagem molecular e modelo translacional para humanos

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Soriano, Sarah Canuto Silva

2015-07-01

The labeling of Ixolaris with {sup 99m}Tc was developed by Barboza et.al. (2013) aiming its use primarily in glioblastoma and after in melanoma diagnosis, a less common but very aggressive cancer and with high mortality rate. Preliminary tests on animals have proven its effectiveness of labeling but a dosimetric study to human clinical trials should be performed. This study aimed to: (1) determine the biokinetic model for the radiotracer {sup 99m}Tc-Ixolaris in mice by imaging dosimetry method; and (2) estimate the absorbed and effective dose resulting from the use of a new radiopharmaceutical for melanoma and metastases diagnosis in human beings, since a dosimetric study of new radiopharmaceuticals in animals is necessary to test them subsequently in humans and apply for registration in ANVISA. According to SPECT images, was found a latency period of 15 to 21 days for the development of lung metastasis in mice. Three C57BL6 mice, one control animal, and two animals with induced cell line B16-F10 murine melanoma were tested. The {sup 99m}Tc-Ixolaris radiopharmaceutical was administered intravenously in a caudal vein, and SPECT images were acquired 0.5 h, 1.5 h, 2.5 h, 3.5 h and 24 h post-administration for analysis and biodistribution quantification. The biokinetic model was determined and thus, obtained cumulative activity in order to estimate the absorbed dose in each organ. The mass and metabolic differences between mice and humans were considered and used to extrapolate the data acquired at different scales. Based on dose factors provided by the software MIRDOSE and Olinda (S factor), absorbed doses in irradiated target organs were calculated for the source organs, and finally the effective dose was estimated. The results indicate that for diagnostic exams conducted in human melanoma patients by administering approximately 25.7 MBq the estimated effective dose was 4.3 mSv. Comparing with effective doses obtained in other diagnostic techniques with {sup 99m}Tc

Noise analysis method for monitoring the moderator temperature coefficient of pressurized water reactors: Neural network calibration

International Nuclear Information System (INIS)

Thomas, J.R. Jr.; Adams, J.T.

1994-01-01

A neural network was trained with data for the frequency response function between in-core neutron noise and core-exit thermocouple noise in a pressurized water reactor, with the moderator temperature coefficient (MTC) as target. The trained network was subsequently used to predict the MTC at other points in the same fuel cycle. Results support use of the method for operating pressurized water reactors provided noise data can be accumulated for several fuel cycles to provide a training base

Importance of parathyroid SPECT and {sup 99m}Tc scintigraphy, and of clinical, laboratorial, ultrasonographic and cytologic correlation in the pre-operative localization of the parathyroid adenoma - pictorial assay;Importancia da complementacao com SPECT e {sup 99m}Tc na cintilografia das paratiroides e da correlacao clinica, laboratorial, ultrassonografica e citologica na localizacao pre-operatoria do adenoma de paratiroide: ensaio pictorico

Energy Technology Data Exchange (ETDEWEB)

Oliveira, Marco Antonio Conde de, E-mail: marco.oliveira@fleury.com.b [Fleury Medicina e Saude, Sao Paulo, SP (Brazil). Servicos de Medicina Nuclear; Maeda, Sergio Setsuo; Dreyer, Patricia; Lobo, Alberto; Andrade, Victor Piana de; Hoff, Ana O.; Biscolla, Rosa Paula Mello; Smanio, Paola; Brandao, Cynthia M.A.; Vieira, Jose G. [Fleury Medicina e Saude, Sao Paulo, SP (Brazil)

2010-06-15

Objective: In patients with primary hyperparathyroidism, candidates for surgical intervention, the parathyroid pre-operative localization is of fundamental importance in planning the appropriate surgical approach. Materials and methods: The additional acquisition of SPECT and Technetium-99m images, during parathyroid scintigraphy with Sestamibi, is not common practice. Usually, only planar image acquisition, 15 minutes prior and 2 hours after radiopharmaceutical administration, is performed. Results: in our experience, the complete protocol in parathyroid scintigraphy increases the accuracy of pre-operative parathyroid localization. Conclusion: the complete utilization of all available nuclear medicine methods (SPECT e {sup 99m}Tc) and image interpretation in a multidisciplinary context can improve the accuracy of parathyroid scintigraphy. (author)

Simultaneous 99mTC and 123I Dual-Isotope Brain Striatal Phantom Single Photon Emission Computed Tomography: Validation of 99mTC-Trodat-1 and 123I-IBZM Simultaneous Dopamine System Brain Imaging

OpenAIRE

Pan-Fu Kao; Shiaw-Pyng Wey; An-Shoei Yang

2009-01-01

[2[[2-[[[3-(4-chlorophenyl)-8-methyl-8-azabicyclo[3,2,1]-oct-2-yl]-methyl](2-mercaptoethyl)amino]ethyl]amino]ethanethiolato(3-)-N2,N2′,S2,S2]oxo-[1R-exo-exo)])-[99mTc]-technetium (99mTc-TRODAT-1) and 123I-iodobenzamide (123I-IBZM) are radiotracers for brain dopamine preand postsynaptic neuron imaging. The purpose of this study was to evaluate imaging parameters and crossed energy interference using simultaneous single photon emission computed tomography (SPECT) 99mTc and 123I data acquisition...

Neural correlate of resting-state functional connectivity under α2 adrenergic receptor agonist, medetomidine.

Science.gov (United States)

Nasrallah, Fatima A; Lew, Si Kang; Low, Amanda Si-Min; Chuang, Kai-Hsiang

2014-01-01

Correlative fluctuations in functional MRI (fMRI) signals across the brain at rest have been taken as a measure of functional connectivity, but the neural basis of this resting-state MRI (rsMRI) signal is not clear. Previously, we found that the α2 adrenergic agonist, medetomidine, suppressed the rsMRI correlation dose-dependently but not the stimulus evoked activation. To understand the underlying electrophysiology and neurovascular coupling, which might be altered due to the vasoconstrictive nature of medetomidine, somatosensory evoked potential (SEP) and resting electroencephalography (EEG) were measured and correlated with corresponding BOLD signals in rat brains under three dosages of medetomidine. The SEP elicited by electrical stimulation to both forepaws was unchanged regardless of medetomidine dosage, which was consistent with the BOLD activation. Identical relationship between the SEP and BOLD signal under different medetomidine dosages indicates that the neurovascular coupling was not affected. Under resting state, EEG power was the same but a depression of inter-hemispheric EEG coherence in the gamma band was observed at higher medetomidine dosage. Different from medetomidine, both resting EEG power and BOLD power and coherence were significantly suppressed with increased isoflurane level. Such reduction was likely due to suppressed neural activity as shown by diminished SEP and BOLD activation under isoflurane, suggesting different mechanisms of losing synchrony at resting-state. Even though, similarity between electrophysiology and BOLD under stimulation and resting-state implicates a tight neurovascular coupling in both medetomidine and isoflurane. Our results confirm that medetomidine does not suppress neural activity but dissociates connectivity in the somatosensory cortex. The differential effect of medetomidine and its receptor specific action supports the neuronal origin of functional connectivity and implicates the mechanism of its sedative

Influence of alumina phases on the molybdenum adsorption capacity and chemical stability for {sup 99}Mo/{sup 99m}Tc generators columns

Energy Technology Data Exchange (ETDEWEB)

Guedes-Silva, Cecilia C.; Ferreira, Thiago dos Santos; Paula, Carolina M. de; Otubo, Larissa, E-mail: cecilia.guedes@ipen.br [Instituto de Pesquisas Energeticas e Nucleares (IPEN/CNEN-SP), Sao Paulo, SP (Brazil); Carvalho, Flavio M.S. [Universidade de Sao Paulo (IGC/USP), SP (Brazil). Instituto de Geociencias

2016-07-15

Technetium-{sup 99m} is the clinically most used radionuclide worldwide. Although many techniques can be applied to separate {sup 99}Mo and {sup 99m}Tc, the most commonly used method is the column chromatography with alumina as stationary phase. However, the alumina nowadays used has limited adsorption capacity of molybdate ions which implies the need to develop or improve materials to produce high specific activity generators. In this paper, alumina was obtained by a solid state method and heat treatments at different conditions. The powders had a microstructure with porous particles of γ, δ, θ and α-Al{sub 2}O{sub 3} phases as well as specific surface area between 36 and 312 m{sup 2} g{sup -1}. Most interesting results were reached by powders calcined at 900 deg C for 5 hours which had high chemical stability and a molybdenum adsorption capacity of 92.45 mg Mo per g alumina. (author)

Minimum toe clearance events in divided attention treadmill walking in older and young adults: a cross-sectional study.

Science.gov (United States)

Santhiranayagam, Braveena K; Lai, Daniel T H; Sparrow, W A; Begg, Rezaul K

2015-07-12

Falls in older adults during walking frequently occur while performing a concurrent task; that is, dividing attention to respond to other demands in the environment. A particularly hazardous fall-related event is tripping due to toe-ground contact during the swing phase of the gait cycle. The aim of this experiment was to determine the effects of divided attention on tripping risk by investigating the gait cycle event Minimum Toe Clearance (MTC). Fifteen older adults (mean 73.1 years) and 15 young controls (mean 26.1 years) performed three walking tasks on motorized treadmill: (i) at preferred walking speed (preferred walking), (ii) while carrying a glass of water at a comfortable walking speed (dual task walking), and (iii) speed-matched control walking without the glass of water (control walking). Position-time coordinates of the toe were acquired using a 3 dimensional motion capture system (Optotrak NDI, Canada). When MTC was present, toe height at MTC (MTC_Height) and MTC timing (MTC_Time) were calculated. The proportion of non-MTC gait cycles was computed and for non-MTC gait cycles, toe-height was extracted at the mean MTC_Time. Both groups maintained mean MTC_Height across all three conditions. Despite greater MTC_Height SD in preferred gait, the older group reduced their variability to match the young group in dual task walking. Compared to preferred speed walking, both groups attained MTC earlier in dual task and control conditions. The older group's MTC_Time SD was greater across all conditions; in dual task walking, however, they approximated the young group's SD. Non-MTC gait cycles were more frequent in the older group across walking conditions (for example, in preferred walking: young - 2.9 %; older - 18.7 %). In response to increased attention demands older adults preserve MTC_Height but exercise greater control of the critical MTC event by reducing variability in both MTC_Height and MTC_Time. A further adaptive locomotor control strategy to reduce

Schizophrenia alters intra-network functional connectivity in the caudate for detecting speech under informational speech masking conditions.

Science.gov (United States)

Zheng, Yingjun; Wu, Chao; Li, Juanhua; Li, Ruikeng; Peng, Hongjun; She, Shenglin; Ning, Yuping; Li, Liang

2018-04-04

Speech recognition under noisy "cocktail-party" environments involves multiple perceptual/cognitive processes, including target detection, selective attention, irrelevant signal inhibition, sensory/working memory, and speech production. Compared to health listeners, people with schizophrenia are more vulnerable to masking stimuli and perform worse in speech recognition under speech-on-speech masking conditions. Although the schizophrenia-related speech-recognition impairment under "cocktail-party" conditions is associated with deficits of various perceptual/cognitive processes, it is crucial to know whether the brain substrates critically underlying speech detection against informational speech masking are impaired in people with schizophrenia. Using functional magnetic resonance imaging (fMRI), this study investigated differences between people with schizophrenia (n = 19, mean age = 33 ± 10 years) and their matched healthy controls (n = 15, mean age = 30 ± 9 years) in intra-network functional connectivity (FC) specifically associated with target-speech detection under speech-on-speech-masking conditions. The target-speech detection performance under the speech-on-speech-masking condition in participants with schizophrenia was significantly worse than that in matched healthy participants (healthy controls). Moreover, in healthy controls, but not participants with schizophrenia, the strength of intra-network FC within the bilateral caudate was positively correlated with the speech-detection performance under the speech-masking conditions. Compared to controls, patients showed altered spatial activity pattern and decreased intra-network FC in the caudate. In people with schizophrenia, the declined speech-detection performance under speech-on-speech masking conditions is associated with reduced intra-caudate functional connectivity, which normally contributes to detecting target speech against speech masking via its functions of suppressing masking-speech signals.

The interest of the C15O2 method for the left to right cardiac shunts evaluation. A comparison with the sup(99m)Tc pertechnetate method

International Nuclear Information System (INIS)

Therain, F.; Gros, J.; Debrun, D.; Blond, M.T.; Valois, M.

1982-01-01

99mTc pertechnetate dilution method (TcM) is a reference for the left to right shunts (L→RS) evaluation as well as oxymetry is. Another radionuclide method using C 15 O 2 (CO 2 M) was compared with TcM. The results obtained with CO 2 M confirm the reliability of the CO 2 M for the L→RS investigation. Characteristics of both non invasive radionuclide methods are summarized. The advantages of CO 2 M are that it is always available even in presence of valvular insufficiency, severe congestive heart failure, multiple cardiac lesions and that it is always repeatable giving an intra assay control unaccessible to TcM and finally it produces a much lower radiation absorbed dose with a special interest for children investigations

Functional assessment of hepatocytes after transplantation into rat spleen

International Nuclear Information System (INIS)

Woods, R.J.; Fuller, B.J.; Attenburrow, V.D.; Nutt, L.H.; Hobbs, K.E.

1982-01-01

The retention of structural integrity and metabolic function by isolated hepatocytes after ectopic transplantation has been investigated in autografted rats. Rats were partially hepatectomized and isolated hepatocytes prepared from the excised liver lobes were implanted into their spleens. Histological examination of the spleens 7 or more weeks after implantation revealed aggregates of hepatocytes in the red pulp. Two tests of biochemical function were applied to the hepatocytes after transplantation. In the first the hepatobiliary imaging agent technetium-99m N-[N'-(2, 6-dimethylphenyl)carbamoylmethyl]iminodiacetic acid (99mTc HIDA), which was shown to be avidly taken up by isolated hepatocytes in vitro, was infused into the tail veins of autograft and control rats. Radioactivity accumulating in the spleens of autografted rats was markedly greater than that in controls implanted with lethally damaged cells or in nontransplanted rats. In the second the presence of bilirubin metabolites was sought in autograft spleens after intravenous infusion of bilirubin. Both mono- and diglucuronides of bilirubin were recovered from the spleens of autograft rats but no conjugates were recovered from the spleens of unoperated controls. We conclude that after autotransplantation isolated hepatocytes retain their morphology and at least some of their functional activities

An estimator of the survival function based on the semi-Markov model under dependent censorship.

Science.gov (United States)

Lee, Seung-Yeoun; Tsai, Wei-Yann

2005-06-01

Lee and Wolfe (Biometrics vol. 54 pp. 1176-1178, 1998) proposed the two-stage sampling design for testing the assumption of independent censoring, which involves further follow-up of a subset of lost-to-follow-up censored subjects. They also proposed an adjusted estimator for the survivor function for a proportional hazards model under the dependent censoring model. In this paper, a new estimator for the survivor function is proposed for the semi-Markov model under the dependent censorship on the basis of the two-stage sampling data. The consistency and the asymptotic distribution of the proposed estimator are derived. The estimation procedure is illustrated with an example of lung cancer clinical trial and simulation results are reported of the mean squared errors of estimators under a proportional hazards and two different nonproportional hazards models.

Time evolution of a Gaussian class of quasi-distribution functions under quadratic Hamiltonian.

Science.gov (United States)

Ginzburg, D; Mann, A

2014-03-10

A Lie algebraic method for propagation of the Wigner quasi-distribution function (QDF) under quadratic Hamiltonian was presented by Zoubi and Ben-Aryeh. We show that the same method can be used in order to propagate a rather general class of QDFs, which we call the "Gaussian class." This class contains as special cases the well-known Wigner, Husimi, Glauber, and Kirkwood-Rihaczek QDFs. We present some examples of the calculation of the time evolution of those functions.

A modular open platform for systematic functional studies under physiological conditions

Science.gov (United States)

Mulholland, Christopher B.; Smets, Martha; Schmidtmann, Elisabeth; Leidescher, Susanne; Markaki, Yolanda; Hofweber, Mario; Qin, Weihua; Manzo, Massimiliano; Kremmer, Elisabeth; Thanisch, Katharina; Bauer, Christina; Rombaut, Pascaline; Herzog, Franz; Leonhardt, Heinrich; Bultmann, Sebastian

2015-01-01

Any profound comprehension of gene function requires detailed information about the subcellular localization, molecular interactions and spatio-temporal dynamics of gene products. We developed a multifunctional integrase (MIN) tag for rapid and versatile genome engineering that serves not only as a genetic entry site for the Bxb1 integrase but also as a novel epitope tag for standardized detection and precipitation. For the systematic study of epigenetic factors, including Dnmt1, Dnmt3a, Dnmt3b, Tet1, Tet2, Tet3 and Uhrf1, we generated MIN-tagged embryonic stem cell lines and created a toolbox of prefabricated modules that can be integrated via Bxb1-mediated recombination. We used these functional modules to study protein interactions and their spatio-temporal dynamics as well as gene expression and specific mutations during cellular differentiation and in response to external stimuli. Our genome engineering strategy provides a versatile open platform for efficient generation of multiple isogenic cell lines to study gene function under physiological conditions. PMID:26007658

Contribution of sup(99m)Tc pertechnetate brain scintigraphy in the diagnosis of tumours of posterior fossa

International Nuclear Information System (INIS)

Sergent, Aline.

1976-01-01

The present work concerns 38 posterior cranial fossa tumour cases subjected to sup(99m)Tc pertechnetate brain scintigraphy between May 1974 and June 1976. 33 of these patients have undergone an anatomical check while for the remaining 5, the existence of a posterior fossa tumour is established from the conjunction of clinical signs and other paraclinical examinations. The procedure was the same for all these 38 patients: after a 300 μC/kg injection of tracer, an immediate angioscintigraphic period, an early set of pictures (half an hour after the tracer injection) then delayed set (4 to 5 hours later) taken from 4 angles: front, back and two profiles. The examination was performed with an OHIO NUCLEAR SIEMENS gamma camera and sometimes a conventional scanner as well (the latter giving no better a diagnosis than the former). In 75% of the cases a hyperfixation of the injected tracer was observed and its site located quite accurately in the posterior fossa tumour. The etiology of the lesion could be diagnosed in 'most probable' or 'least probable' terms. Examination of work by other authors, who obtained similar results, leads to the conclusion that this method is very helpful in the diagnosis of posterior fossa tumours when used as a means of early detection, before the undertaking of more complex neuroradiological explorations [fr

Impact of intracellular metallothionein on metal biouptake and partitioning dynamics at bacterial interfaces.

Science.gov (United States)

Présent, Romain M; Rotureau, Elise; Billard, Patrick; Pagnout, Christophe; Sohm, Bénédicte; Flayac, Justine; Gley, Renaud; Pinheiro, José P; Duval, Jérôme F L

2017-11-08

Genetically engineered microorganisms are alternatives to physicochemical methods for remediation of metal-contaminated aquifers due to their remarkable bioaccumulation capacities. The design of such biosystems would benefit from the elaboration of a sound quantitative connection between performance in terms of metal removal from aqueous solution and dynamics of the multiscale processes leading to metal biouptake. In this work, this elaboration is reported for Escherichia coli cells modified to overexpress intracellular metallothionein (MTc), a strong proteinaceous metal chelator. Depletion kinetics of Cd(ii) from bulk solution following biouptake and intracellular accumulation is addressed as a function of cell volume fraction using electroanalytical probes and ligand exchange-based analyses. It is shown that metal biouptake in the absence and presence of MTc is successfully interpreted on the basis of a formalism recently developed for metal partitioning dynamics at biointerfaces with integration of intracellular metal speciation. The analysis demonstrates how fast sequestration of metals by intracellular MTc bypasses metal excretion (efflux) and enhances the rate of metal depletion to an extent such that complete removal is achieved at sufficiently large cell volume fractions. The magnitude of the stability constant of nanoparticulate metal-MTc complexes, as derived from refined analysis of macroscopic bulk metal depletion data, is further confirmed by independent electrochemical measurement of metal binding by purified MTc extracts.

Determination of the worst case for cleaning validation of equipment used in the radiopharmaceutical production of lyophilized reagents for {sup 99m}Tc labelling

Energy Technology Data Exchange (ETDEWEB)

Porto, Luciana Valeria Ferrari Machado; Fukumori, Neuza Taeko Okasaki; Matsuda, Margareth Mie Nakamura, E-mail: luciana.porto@anvisa.gov.br [Instituto de Pesquisas Energeticas e Nucleares (IPEN/CNEN-SP), Sao Paulo, SP (Brazil). Centro de Radiofarmacia

2016-01-15

Cleaning validation, a requirement of the current Good Manufacturing Practices (cGMP) for Drugs, consists of documented evidence that cleaning procedures are capable of removing residues to predetermined acceptance levels. This report describes a strategy for the selection of the worst case product for the production of lyophilized reagents (LRs) for labeling with {sup 99m}Tc from the Instituto de Pesquisas Energeticas e Nucleares (IPEN-CNEN/Sao Paulo). The strategy is based on the calculation of a 'worst case index' that incorporates information about drug solubility, cleaning difficulty, and occupancy rate in the production line. It allowed a reduction in the required number of validations considering the possible manufacturing flow of a given product and the subsequent flow, thus facilitating the process by reducing operation time and cost. The products identified as 'worst case' were LRs PUL-TEC and MIBI-TEC. (author). (author)

Country report: United Kingdom. Bifunctional bisphosphonate complexes with {sup 99m}Tc and {sup 188}Re for the diagnosis and therapy of bone metastases

Energy Technology Data Exchange (ETDEWEB)

Torres Martin de Rosales, Rafael; Blower, P.J., E-mail: rafael.torres@kcl.ac.uk, E-mail: philip.blower@kcl.ac.uk [Division of Imaging Sciences, King' s College London, 4th Floor, Lambeth Wing, St. Thomas Hospital, London (United Kingdom)

2010-07-01

1,1-Bisphosphonates (BPs) are a family of compounds extensively used in the management of disorders of bone metabolism.{sup 1} They accumulate in areas of high bone metabolism, such as bone metastases, and consequently have been receiving increasing attention as molecular imaging probes and pain palliation treatments.{sup 2} Imaging bone metastases with BPs using single photon emission computed tomography (SPECT) or planar scintigraphy is one of the most often-performed clinical imaging procedures. Beta-emitting analogues capable of producing a therapeutic effect have also been developed.{sup 3} In particular, the rhenium compounds {sup 186/188}Re-hydroxyethylidene-1,1-diphosphonate ({sup 186/188}Re-HEDP) have shown promise as palliative agents for bone metastases in recent clinical trials.{sup 4} The radiochemicals consist of a complex of a BP (e.g. methylene diphosphonate, MDP) with gamma- ({sup 99m}Tc) or beta- ({sup 186/186}Re) emitters.

Morphological and functional manifestations of rat adrenal-cortex response to sodium bromide administration under hypodynamic stress

Science.gov (United States)

Kirichek, L. T.; Zholudeva, V. I.

1979-01-01

Functional and morphological manifestations of adrenal cortex response to hypodynamia (2-hr immobilization on an operating table) under the influence of bromine preparations were studied. The sodium bromide was administered intraperitoneally in 100, 250, and 500 mg/kg doses once and repeatedly during ten days. The adrenal gland was evaluated functionally by ascorbic acid and cholesterol content and morphologically by coloring it with hematoxylin-eosin and Sudans for lipid revealing at freezing. Results are displayed in two tables and microphotographs. They are summarized as follows: the bromine weakens the functional state of the adrenal cortex in intact rats, causing changes similar to those under stress. During immobilization combined with preliminary bromine administration, a less pronounced stress reaction is noticeable.

Performance study of molybdenum gels with titanium for preparation of {sup 99}Mo-{sup 99m}Tc generators; Estudo do desempenho de geis de molibdenio com titanio no preparo de geradores de {sup 99}Mo-{sup 99m}Tc

Energy Technology Data Exchange (ETDEWEB)

Moraes, Vanessa; Osso Junior, Joao Alberto [Instituto de Pesquisas Energeticas e Nucleares (IPEN), Sao Paulo, SP (Brazil)]. E-mail: vmoraes@ipen.br

2005-07-01

{sup 99m}Tc is the most used radioisotope in Nuclear Medicine, due to nuclear characteristics. It is obtained by the radioactive decay of {sup 99}Mo, generator of radioisotope system. When {sup 99}Mo is produced by the activation in reactor, the most used technique for the preparation of the generators is the gel type generator, which incorporates {sup 99}Mo to the gel that is insoluble, chemically inert to the solutions and with properties of ion exchange. Several countries had already studied this methodology, as is the case of Vietnam, India, China, Australian. This work has the objective of studying the performance and characterization of molybdenum gels with titanium. Four variables in the preparation of the gel were studied: mass ratio between Mo and Ti (1.80 and 2.25), concentration of NaOH (2 and 4 mol/L), final temperature (25 and 50 deg C) and pH (3.5 and 4.5). The prepared gels were analyzed with relation to the size of its particles, identification of its structure, amount of molybdenum, amount of titanium, profile of elution, pH of the elution, determination of the radioisotopes in the eluate and final radiochemical purity. The final result is a formularization of the gel with the best characteristics for posterior preparation of the generator of {sup 99m}Tc-{sup 99}Mo. (author)

Investigation of Balance Function Using Dynamic Posturography under Electrical-Acoustic Stimulation in Cochlear Implant Recipients

Directory of Open Access Journals (Sweden)

B. Schwab

2010-01-01

Full Text Available Introduction. The purpose of the present study is to investigate the effect of electrical-acoustic stimulation on vestibular function in CI patients by using the EquiTest and to help answer the question of whether electrically stimulating the inner ear using a cochlear implant influences the balance system in any way. Material and Methods. A test population (=50 was selected at random from among the cochlear implant recipients. Dynamic posturography (using the EquiTest was performed with the device switched off an switched on. Results. In summary, it can be said that an activated cochlear implant affects the function of the vestibular system and may, to an extent, even lead to a stabilization of balance function under the static conditions of dynamic posturography, but nevertheless also to a significant destabilization. Significant improvements in vestibular function were seen mainly in equilibrium scores under conditions 4 and 5, the composite equilibrium score, and the vestibular components as revealed by sensory analysis. Conclusions. Only under the static conditions are significantly poorer scores achieved when stimulation is applied. It may be that the explanation for any symptoms of dizziness lies precisely in the fact that they occur in supposedly noncritical situations, since, when the cochlear implant makes increased demands on the balance system, induced disturbances can be centrally suppressed.

Gfr estimation using 99mTc DTPA gates method for assessment of early diabetic nephropathy - a comparison with 24-hour creatinine clearance

International Nuclear Information System (INIS)

Ghafoor, S.; Ali, M.K.; Khan, G.

2014-01-01

To correlate Gates glomerular filtration rate (GGFR) using technetium-99m diethylene triaminepentacetic acid (99mTc DTPA) with 24-hour creatinine clearance (CRCL) and to establish relationship with duration of diabetes in patients with early diabetic nephropathy. Study Design: A cross-sectional comparative study carried out in Nuclear Medical Centre from Aug 2009 to Jan 2010 at Armed Forces Institute of Pathology (AFIP), Rawalpindi, Pakistan. Patients and Methods: A total of eighty three subjects were enrolled, who were divided into three groups; group 1 comprised 31 normotensive diabetics, group 2 had 37 hypertensive diabetics while group 3 had 15 normal subjects. The DTPA GFR and creatinine clearance in healthy subjects as well as diabetic patients were compared using the unpaired student's t-test. The linear association between GFR, creatinine clearance and disease duration was expressed by Pearson's correlation coefficient 'r' along with their significance levels. Results: Gates GFR showed hyperfiltration in normotensive diabetics (96.6 +- 3.3 ml/min/1.73 m/sub 2/), significantly (p<0.05) higher than controls (85.5 +- 5 ml/min/1.73 m/sub 2/), whereas hypertensive diabetics had a significantly lower (p<0.05) Gates GFR (76.8 +- 3.7) than that of controls. Significant degree of correlation existed between GGFR and CRCL in hypertensive diabetics (p<0.05, r=0.716) and controls (r=0.546). Gates GFR also showed good correlation with duration of diabetes in both diabetic groups as compared to that of CRCL. GGFR also correlated well with duration of hypertension 0.37 (0.31-0.43) as compared to CRCL 0.155 (0.15-0.16) in all groups. Conclusions: The 99mTc-DTPA clearance correlates significantly with 24-hour creatinine clearance as well as with disease duration and can provide a simple and convenient index of kidney function in patients of early diabetic nephropathy. (author)

Clinical comparison of 99mTc exametazime and 123I Ioflupane SPECT in patients with chronic mild traumatic brain injury.

Science.gov (United States)

Newberg, Andrew B; Serruya, Mijail; Gepty, Andrew; Intenzo, Charles; Lewis, Todd; Amen, Daniel; Russell, David S; Wintering, Nancy

2014-01-01

This study evaluated the clinical interpretations of single photon emission computed tomography (SPECT) using a cerebral blood flow and a dopamine transporter tracer in patients with chronic mild traumatic brain injury (TBI). The goal was to determine how these two different scan might be used and compared to each other in this patient population. Twenty-five patients with persistent symptoms after a mild TBI underwent SPECT with both (99m)Tc exametazime to measure cerebral blood flow (CBF) and (123)I ioflupane to measure dopamine transporter (DAT) binding. The scans were interpreted by two expert readers blinded to any case information and were assessed for abnormal findings in comparison to 10 controls for each type of scan. Qualitative CBF scores for each cortical and subcortical region along with DAT binding scores for the striatum were compared to each other across subjects and to controls. In addition, symptoms were compared to brain scan findings. TBI patients had an average of 6 brain regions with abnormal perfusion compared to controls who had an average of 2 abnormal regions (pTBI symptoms. Both types of scans might have distinct uses in the evaluation of chronic TBI patients depending on the clinical scenario.

Differences in functional traits between invasive and native Amaranthus species under different forms of N deposition

Science.gov (United States)

Wang, Congyan; Zhou, Jiawei; Liu, Jun; Jiang, Kun

2017-08-01

Differences in functional traits between invasive and native plant species are believed to determine the invasion success of the former. Increasing amounts of anthropogenic nitrogen (N) are continually deposited into natural ecosystems, which may change the relative occurrence of the different N deposition forms (such as NH4-N, NO3-N, and CO(NH2)2-N) naturally deposited. Under high N deposition scenarios, some invasive species may grow faster, gaining advantage over native species. In a greenhouse experiment, we grew invasive and native Amaranthus species from seed both alone and in competition under simulated N enriched environments with different forms of N over 3 months. Then, we measured different leaf traits (i.e., plant height, leaf length, leaf width, leaf shape index, specific leaf area (SLA), and leaf chlorophyll and N concentrations). Results showed that the competition intensity between A. retroflexus and A. tricolor decreased under N deposition. This may be due to the large functional divergence between A. retroflexus and A. tricolor under simulated N deposition. Phenotypic plasticity of SLA and leaf chlorophyll concentration of A. retroflexus were significantly lower than in A. tricolor. The lower range of phenotypic plasticity of SLA and leaf chlorophyll concentration of A. retroflexus may indicate a fitness cost for plastic functional traits under adverse environments. The restricted phenotypic plasticity of SLA and leaf chlorophyll concentration of A. retroflexus may also stabilize leaf construction costs and the growth rate. Meanwhile, the two Amaranthus species possessed greater plasticity in leaf N concentration under NO3-N fertilization, which enhanced their competitiveness.

One-Pot Syntesis of 3-Functionalized 4-Hydroxycoumarin under Catalyst-Free Conditions

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Yang Gao

2018-01-01

Full Text Available A concise and efficient one-pot synthesis of 3-functionalized 4-hydroxycoumarin derivatives via a three-component domino reaction of 4-hydroxycoumarin, phenylglyoxal and 3-arylaminocyclopent-2-enone or 4-arylaminofuran-2(5H-one under catalyst-free and microwave irradiation conditions is described. This synthesis involves a group-assisted purification process, which avoids traditional recrystallization and chromatographic purification methods.

An Optimization Study of LWR Fuel Assembly Design for TRU Burning using FCM and UO{sub 2}-ThO{sub 2} Fuel Pins

Energy Technology Data Exchange (ETDEWEB)

Hwang, Daehee; Hong, Ser Gi [Kyung Hee Univ., Yongin (Korea, Republic of)

2014-05-15

The objective of this work is to design optimized LWR fuel assemblies for the transmutation of TRU (transuranic) nuclides by using FCM (Fully Ceramic Micro-encapsulated) and UO{sub 2}-ThO{sub 2} fuel pins without degradation of safety-related parameters. In our study, the pin pitch (equivalently to P/D (Pitch-to-Diameter) ratio with a fixed fuel rod diameter) is used as a design parameter. The motivation is to make MTC (Moderator Temperature Coefficient) less negative at EOC because it was found that the small LWR core design in our previous work has a very strong MTC at EOC (∼-80pcm/K) which can lead to a large positive reactivity insertion under MSLB (Main Steam Line Break) accident and to a reduction of shutdown margin of the control rods. The basic idea is to increase moderator-to-fuel ratio such that the fuel assemblies have less negative MTC due to increase the moderation. The results show that a small increase of P/D ratio by 3.8% can give a considerably less negative MTC and an increase of TRU destruction rate without an increase of pin power peaking. In our study, a special emphasis is given on the effects of the increased P/D ratio for MTC. From the results, it was found that an increase of P/D ratio (we considered up to P/D=1.38) leads to a less negative MTC and a less negative FTC, an increase of TRU destruction rate, and a decrease of {sup 233}U production in UO{sub 2}-ThO{sub 2} pins. In particular, a small change of P/D ratio from 1.33 to 1.38 led to a change of MTC from - 75 pcm/.deg. C to -67 pcm/.deg. C at EOC, and a small increase of net TRU destruction rate from 26.4% to 28.3%. As conclusion, a small increase of P/D ratio is effective in obtaining the less negative MTC at EOC with a small increase of TRU destruction rate and without a significant degradation of FTC.

Impact of Gate 99mTc DTPA GFR, Serum Creatinine and Urea in Diagnosis of Patients with Chronic Kidney Failure

Science.gov (United States)

Miftari, Rame; Nura, Adem; Topçiu-Shufta, Valdete; Miftari, Valon; Murseli, Arbenita; Haxhibeqiri, Valdete

2017-01-01

Aim: The aim of this study was determination of validity of 99mTcDTPA estimation of GFR for early detection of chronic kidney failure Material and methods: There were 110 patients (54 males and 56 females) with kidney disease referred for evaluation of renal function at UCC of Kosovo. All patients were included in two groups. In the first group were included 30 patients confirmed with renal failure, whereas in the second group were included 80 patients with other renal disease. In study were included only patients with ready results of creatinine, urea and glucose in the blood serum. For estimation of GFR we have used the Gate GFR DTPA method. The statistical data processing was conducted using statistical methods such as arithmetic average, the student t-test, percentage or rate, sensitivity, specificity and accuracy of the test. Results: The average age of all patients was 36 years old. The average age of female was 37 whereas of male 35. Patients with renal failure was significantly older than patients with other renal disease (p<0.005). Renal failure was found in 30 patients (27.27%). The concentration of urea and creatinine in blood serum of patients with renal failure were significantly higher than in patients with other renal disease (P< 0.00001). GFR in patients with renal failure were significantly lower than in patients with other renal disease, 51.75 ml/min (p<0.00001). Sensitivity of uremia and creatininemia for detection of renal failure were 83.33%, whereas sensitivity of 99mTcDTPA GFR was 100%. Specificity of uraemia and creatininemia were 63% whereas specificity of 99mTcDTPA GFR was 47.5%. Diagnostic accuracy of blood urea and creatinine in detecting of renal failure were 69%, whereas diagnostic accuracy of 99mTcDTPA GFR was 61.8%. Conclusion: Gate 99mTc DTPA scintigraphy in collaboration with biochemical tests are very sensitive methods for early detection of patients with chronic renal failure. PMID:28883673

75 FR 43797 - Delegation of Certain Functions Under Section 1264 of the Victims of Iranian Censorship Act...

Science.gov (United States)

2010-07-26

... Certain Functions Under Section 1264 of the Victims of Iranian Censorship Act (Public Law 111-84, Subtitle... State, the functions conferred upon the President by section 1264 of the Victims of Iranian Censorship...

The method of activity determination of Tc-99m in ionization chamber

International Nuclear Information System (INIS)

Broda, R.

1980-01-01

The paper presents a method of finding the efficiency of sup(99m)Tc activity measurements in the ionization chamber, basing on 99 Mo activity measurements and the activity ratio of sup(99m)Tc to 99 Mo in 99 Mo + sup(99m)Tc solution. The activity of 99 Mo has been determined in 4πβ-γ coincidence system with liquid scintillator in β channel by means of the absolute method of two-stage coincidence. The activity ratio of sup(99m)Tc to 99 Mo has been determined by means of spectrometric method. The 99 Mo and sup(99m)Tc activities have been measured in 99 Mo + sup(99m)Tc generators, and the activity of sup(99m)Tc solution after elution has been measured. It has been shown that sup(99m)Tc activity, determined by means of the chamber method on the basis of the efficiency found, corresponds to the activity determined by means of spectrometric method, and that sup(99m)Tc activity, measured in generator before elution, is equal to the sum of sup(99m)Tc activity eluted and the one remained in generator. (author)

Prognosis and submandibular function of Bell's palsy as evaluated using submandibular scan with sup(99m)Tc

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Ino, Chiyonori; Yamashita, Toshio; Tomoda, Koichi; Kumazawa, Tadami (Kansai Medical School, Moriguchi, Osaka (Japan))

1983-06-01

The function of the submandibular gland of 32 patients with Bell's palsy was examined with radio-isotope (RI) scintigraphy using sup(99m)Tc-pertechnetate; and the relationship between the function of the gland and the prognosis of palsy was discussed. Uptake and secretion of the RI in the glands on both sides were measured twice, the first time within 10 days of the onset of palsy, and the second time 3 to 4 weeks after the onset. The results were as follows: 1) In the case in which the function of the affected side was higher than that of normal side, the prognosis was good. 2) In the case in which the function of the affected side was lower than the normal in the first test but improved in the second test, the prognosis was also good. 3) In the case in which the function of the affected side was lower than the normal in the first test, and worsened in the second test, the prognosis was poor. In conclusion, the application of RI scincigraphy was thought to be very useful for early diagnosis of Bell's palsy.

Cerebral hemodynamics and functional prognosis in hydrocephalus

Energy Technology Data Exchange (ETDEWEB)

Hirai, Osamu; Nishikawa, Michio; Watanabe, Shu; Yamakawa, Hiroyasu; Kinoshita, Yoshimasa; Uno, Akira; Handa, Hajime (Hamamatsu Rosai Hospital, Shizuoka (Japan))

1989-11-01

The functional outcome of cerebral hemodynamics in the chronic stage of juvenile hydrocephalus was determined using single photon emission computed tomography (SPECT). Five patients including three with aqueductal stenosis, one with post-meningitic hydrocephalus, and one case with hydrocephalus having developed after repair of a huge occipital encephalocele. Early images of cerebral blood flow (CBF) were obtained 25 minutes after intravenous injection of 123-I-iodoamphetamine (IMP), and late images were scanned 3 hours later. Cerebral blood volume (CBV) was also measured using {sup 99m}Tc in three patients. Twenty cases with adult communicating hydrocephalus were also investigated from the point of view of shunt effectiveness. Although there was no remarkable change in the cerebrovascular bed in the juvenile cases, CBF of the remnant brain parenchyma was good irrespective of the degree of ventricular dilatation. There was a periventricular-related IMP uptake in each case; however, it somehow matched the ventricular span. Functional outcome one to 23 years after the initial shunt operation was good in every case, despite multiple shunt revisions. Redistribution on late images had no bearing on clinical states. In adult cases, 8 patients with effective shunting demonstrated a relatively localized periventricular low perfusion, with preoperative increased cerebrospinal fluid (CSF) pressure. On the contrary, 12 patients with no improvement with or without ventricular-reduced IMP uptake, despite low CSF pressure. The present study indicates that periventricular hemodynamics may play an important role in cerebral function compromised by hydrocephalus. (J.P.N.).

Whole-body function-scintigraphic investigations for the determination of reginal blood volumina and their variations

International Nuclear Information System (INIS)

Mostbeck, A.; Partsch, H.

1976-01-01

Changes of regional blood volume in the different parts of the body were observed by functional whole body scanning after injection of a tracer which remains sufficiently in the vascular beds to enable acute examinations sup(99m)Tc. In 21 persons changes of regional blood volume compression of both legs) and by pharmacological influences (dihydroergotamine, nifedipine, nitroglycerin, noradrenalin, dopamin). In both venous occlusion and compression of the legs a reciprocal relationship was observed between the blood volume of the legs and that of the central regions of the body. Dihydroergotamine, noradrenalin and dopamin caused a displacement of blood volume towards the central regions. After the application of nitroglycerin there was an increase of blood volume in the arms and in the legs and a distinct decrease of the thoracal blood volume

Evaluation of Language Function under Awake Craniotomy

Science.gov (United States)

KANNO, Aya; MIKUNI, Nobuhiro

2015-01-01

Awake craniotomy is the only established way to assess patients’ language functions intraoperatively and to contribute to their preservation, if necessary. Recent guidelines have enabled the approach to be used widely, effectively, and safely. Non-invasive brain functional imaging techniques, including functional magnetic resonance imaging and diffusion tensor imaging, have been used preoperatively to identify brain functional regions corresponding to language, and their accuracy has increased year by year. In addition, the use of neuronavigation that incorporates this preoperative information has made it possible to identify the positional relationships between the lesion and functional regions involved in language, conduct functional brain mapping in the awake state with electrical stimulation, and intraoperatively assess nerve function in real time when resecting the lesion. This article outlines the history of awake craniotomy, the current state of pre- and intraoperative evaluation of language function, and the clinical usefulness of such functional evaluation. When evaluating patients’ language functions during awake craniotomy, given the various intraoperative stresses involved, it is necessary to carefully select the tasks to be undertaken, quickly perform all examinations, and promptly evaluate the results. As language functions involve both input and output, they are strongly affected by patients’ preoperative cognitive function, degree of intraoperative wakefulness and fatigue, the ability to produce verbal articulations and utterances, as well as perform synergic movement. Therefore, it is essential to appropriately assess the reproducibility of language function evaluation using awake craniotomy techniques. PMID:25925758

Evaluation of Language Function under Awake Craniotomy.

Science.gov (United States)

Kanno, Aya; Mikuni, Nobuhiro

2015-01-01

Awake craniotomy is the only established way to assess patients' language functions intraoperatively and to contribute to their preservation, if necessary. Recent guidelines have enabled the approach to be used widely, effectively, and safely. Non-invasive brain functional imaging techniques, including functional magnetic resonance imaging and diffusion tensor imaging, have been used preoperatively to identify brain functional regions corresponding to language, and their accuracy has increased year by year. In addition, the use of neuronavigation that incorporates this preoperative information has made it possible to identify the positional relationships between the lesion and functional regions involved in language, conduct functional brain mapping in the awake state with electrical stimulation, and intraoperatively assess nerve function in real time when resecting the lesion. This article outlines the history of awake craniotomy, the current state of pre- and intraoperative evaluation of language function, and the clinical usefulness of such functional evaluation. When evaluating patients' language functions during awake craniotomy, given the various intraoperative stresses involved, it is necessary to carefully select the tasks to be undertaken, quickly perform all examinations, and promptly evaluate the results. As language functions involve both input and output, they are strongly affected by patients' preoperative cognitive function, degree of intraoperative wakefulness and fatigue, the ability to produce verbal articulations and utterances, as well as perform synergic movement. Therefore, it is essential to appropriately assess the reproducibility of language function evaluation using awake craniotomy techniques.

Myocardial perfusion and left ventricular function during exercise evaluated by 201Tl myocardial scintigraphy and 99mTc radionuclide ventriculography in patients treated with PTCA

International Nuclear Information System (INIS)

Honda, Toshio; Jo, Tadafumi; Doiuchi, Junji

1992-01-01

To evaluate the effects of percutaneous transluminal coronary angioplasty (PTCA), we investigated myocardial ischemia and left ventricular function during exercise before and after successful PTCA in 30 patients. We used extent and severity scores of 201 thallium ( 201 Tl) exercise myocardial scintigraphy to assess myocardial ischemia and determined global and regional left ventricular ejection fraction (EF and REF) of 99m Tc-RBC exercise radionuclide ventriculography to assess left ventricular function. The extent and severity scores of stress images were significantly less after PTCA than before PTCA. The scores of the redistribution images were unchanged before and after PTCA. Global EF during exercise was significantly higher after PTCA than before PTCA. There was no difference in resting global EF between before and after PTCA. Myocardial ischemia induced by exercise was semi-quantitatively analyzed as transient perfusion defect with severity score. Severity score was significantly less after PTCA than before PTCA. ΔEF, which was obtained by subtraction of resting global EF from exercise one, was significantly higher after PTCA than before PTCA. However, the degree of improvement in myocardial ischemia and left ventricular function varied from patient to patient. In 17 patients with one-vessel left anterior descending artery disease, ΔREF, which was determined by subtracting resting regional EF from exercise one, was significantly higher in septal and apical segments after PTCA than before PTCA. Myocardial ischemia and left ventricular function under exercise were alleviated by PTCA. However, the degree of improvement varied from patient to patient and it might have been affected by various factors including coronary dissection, edema, thrombus, restenosis, spasm, side branch stenosis or occlusion, distal thrombus, and myocardial hibernation. (author)

Synthesis, labeling with {sup 99m}Tc and biokinetics of brains scintigraphy diaminodithiol perfusion radiopharmaceuticals; Sintese, marcacao com {sup 99m}Tc e biocinetica de radiofarmacos perfusorios diaminoditiolicos para cintilografias cerebrais

Energy Technology Data Exchange (ETDEWEB)

Goncalves, Marcos Moises

1999-07-01

The recent tomography status using radiopharmaceuticals have been contributing greatly with the 'age of certainty' in the diagnosis examination of syndromes, pathologies and clinical signs, because they can evidence some phenomena occurring in a molecular manner. The purpose of this work have had the development of new diaminodithiol (DADT) perfusion radiopharmaceuticals to be used in brain diagnosis using S.P.E.T. (Single Photon Emission Tomography). Initially, the rational planning had been performed with the new DADT molecular structures as radiopharmaceutical candidates. Using of Q.S.A.R. (Quantitative Structure Activity Relationship) techniques, the molecular descriptors such as partition coefficient and effective polarizability, have been studied in order to increase the blood brain barrier transport and the brain uptake respectively. Applying the Q.S.P.R. (Quantitative Structure Property Relationship) concepts to perform drug latentiation, based on bio-labile functional groups, the congener DADT derivative has been transformed into a pro-drug that works as a DADT moiety carrier, allowing the increasing of brain radiopharmaceutical uptake. Later on, synthetic routes and chemical purifications have been developed allowing the creation of the proposed chemical structure. Each new DADT derivative has been synthesized and analyzed in terms of elemental analysis, infrared and NMR spectra, in order to confirm its proposed chemical structure. Then, the new derivative has been labeled with {sup 99m}Tc, radiochemically purified, intravenously injected in Swiss mice, allowing its biodistribution to evidence its brain transport and uptake. The rational planning studies have been re-evaluated after each biodistribution had been performed, to see what kind of molecular descriptor was responsible for causing a stronger optimization in the brain perfusion characteristics and then, new DADT derivatives have been prepared. Three new DADT derivatives have been

Synthesis, labeling with {sup 99m}Tc and biokinetics of brains scintigraphy diaminodithiol perfusion radiopharmaceuticals; Sintese, marcacao com {sup 99m}Tc e biocinetica de radiofarmacos perfusorios diaminoditiolicos para cintilografias cerebrais

Energy Technology Data Exchange (ETDEWEB)

Goncalves, Marcos Moises

1999-07-01

The recent tomography status using radiopharmaceuticals have been contributing greatly with the 'age of certainty' in the diagnosis examination of syndromes, pathologies and clinical signs, because they can evidence some phenomena occurring in a molecular manner. The purpose of this work have had the development of new diaminodithiol (DADT) perfusion radiopharmaceuticals to be used in brain diagnosis using S.P.E.T. (Single Photon Emission Tomography). Initially, the rational planning had been performed with the new DADT molecular structures as radiopharmaceutical candidates. Using of Q.S.A.R. (Quantitative Structure Activity Relationship) techniques, the molecular descriptors such as partition coefficient and effective polarizability, have been studied in order to increase the blood brain barrier transport and the brain uptake respectively. Applying the Q.S.P.R. (Quantitative Structure Property Relationship) concepts to perform drug latentiation, based on bio-labile functional groups, the congener DADT derivative has been transformed into a pro-drug that works as a DADT moiety carrier, allowing the increasing of brain radiopharmaceutical uptake. Later on, synthetic routes and chemical purifications have been developed allowing the creation of the proposed chemical structure. Each new DADT derivative has been synthesized and analyzed in terms of elemental analysis, infrared and NMR spectra, in order to confirm its proposed chemical structure. Then, the new derivative has been labeled with {sup 99m}Tc, radiochemically purified, intravenously injected in Swiss mice, allowing its biodistribution to evidence its brain transport and uptake. The rational planning studies have been re-evaluated after each biodistribution had been performed, to see what kind of molecular descriptor was responsible for causing a stronger optimization in the brain perfusion characteristics and then, new DADT derivatives have been prepared. Three new DADT derivatives have been obtained by

Influence of gender, age and motives underlying food choice on perceived healthiness and willingness to try functional foods.

Science.gov (United States)

Ares, Gastón; Gámbaro, Adriana

2007-07-01

The aims of the present study were to study the effect of different carriers and enrichments on the perceived healthiness and willingness to try functional foods; and to evaluate the effect of age, gender and motives underlying food choice. Participants had to evaluate different functional food concepts and had to answer a food choice questionnaire. Results showed that carrier products had the largest effect on consumers' perception of healthiness and willingness to try of the evaluated functional foods concepts. The highest positive relative utilities were achieved when the enrichment was a functional ingredient inherent in the product. Furthermore, gender, age and motives underlying food choice affected the preference patterns for the evaluated functional foods concepts, but it depended on the carrier and enrichment considered, suggesting that functional foods might not be accepted by all the consumers and that they could be tailored for certain groups.

Effect of exercise on erythrocyte count and blood activity concentration after /sup 99m/Tc in vivo red blood cell labeling

International Nuclear Information System (INIS)

Konstam, M.A.; Tu'meh, S.; Wynne, J.; Beck, J.R.; Kozlowski, J.; Holman, B.L.

1982-01-01

We studied the effect of exercise on blood radiotracer concentration after /sup 99m/Tc in vivo red blood cell labeling. After red blood cell labeling, 13 subjects underwent maximal supine bicycle exercise. Radioactivity, analyzed with a well counter, was measured in heparinized venous blood samples drawn at rest and during peak exercise. Changes in activity were compared with changes in erythrocyte count. Activity and erythrocyte counts increased during exercise in all 13 subjects. Percent increase in activity correlated with percent increase in erythrocyte count (r . -0.78), but did not correlate with either duration of exercise or maximal heart rate. Twenty minutes after termination of exercise, activity and erythrocyte count had decreased from peak exercise values but remained higher than preexercise values. In nine nonexercised control subjects, samples drawn 20 minutes apart showed no change in activity or in erythrocyte count. We conclude that exercise increases blood activity, primarily because of an increase in erythrocyte count. During radionuclide ventriculography, blood activity must be measured before and after any intervention, particularly exercise, before a change in left ventricular activity can be attributed to a change in left ventricular volume

Study of different adsorbent materials for the preparation of generator systems of 99Mo - 99mTc and 188W-188Re

International Nuclear Information System (INIS)

Lopes, Paula Regina Corain

2009-01-01

Amongst some existing radioisotopes, 99m Tc and 188 Re present adequate physical chemical properties for use in Nuclear Medicine in the areas of diagnosis and therapy, respectively. Moreover, these radioisotopes can be distributed to medical centers in the form of generator systems of 99 Mo- 99m Tc and 188 W- 188 Re, allowing autonomy and practicity in use. The objective of this work consists of determining the capacity of some adsorbent materials for retention of molibdenium and tungsten, aiming the optimization of generator systems of 99 Mo- 99 mTc and 188 W- 188 Re with suitable characteristics for application in Nuclear Medicine. Known amounts, in mass, of molybdenum (Mo) and tungsten (W) were added to the loading solutions previously prepared, with values of pH adjusted between 1 and 7, and these were then percolated through different devices containing in its interior alumina, resin or poly-zirconium compound also known as PZC. The elutions were carried out within an interval of time of approximately 24 hours for the generator systems of 99 Mo - 99 mTc and 48 hours for the generator systems of 188 W- 188 Re due to the difference between the half-lives of radionuclides involved in the reactions. The eluted samples from both generator systems containing 99m Tc or 188 Re were submitted to quality control tests aiming to evaluate the radionuclidic, radiochemical and chemical purity, but no significant contamination for 99 Mo, 188 W, technetium or rhenium in the colloidal states and zirconium were detected in the eluted solutions and in the solutions extracted with saline solution for any value of pH studied. The commercial alumina cartridges known as Acid Sep Pak were more efficient in retaining the molybdenum in the loading solutions when compared with the others commercial retention devices employed. However, when this comparison extends to the chromatographic alumina columns, the use of acid alumina as adsorbent is more efficient when compared to the Acid Sep

Labeling of creatinine with technetium-99m

Energy Technology Data Exchange (ETDEWEB)

Yurt Lambrecht, F. [Ege Univ., Bornova, Izmir (Turkey). Dept. of Nuclear Applications, Inst. of Nuclear Sciences; Durkan, K. [Dokuz Eylul Univ., Buca, Izmir (Turkey). Chemistry Technicianship Program, Izmir Vocational School; Soylu, A. [Dokuz Eylul Univ., Narlidere, Izmir (Turkey). Dept. of Pediatrics, Medical Faculty

2004-07-01

Creatinine is a clinically important index of renal glomerular filtration rate. Urine creatinine levels can be used as a screening test to evaluate kidney function or can be part of the creatinine clearance test. In case of kidney dysfunction or muscle disorders the creatinine concentration in serum/plasma may rise to a higher value than in healthy body. Technetium- 99m has been used in nuclear medicine and in biomedical research to label molecular and cellular structures employed as radiotracers. {sup 99m}Tc is utilized to label molecules and cells, used as radiopharmaceuticals, and also to label biological species. It presents many desirable characteristics. SnCl{sub 2} method is frequently used as a reducing agent in the {sup 99m}Tc- labeling process. Creatinine metabolism might be investigated by using labeled {sup 99m}Tc- creatinine in healthy or uremic rats. (orig.)

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)

Scintigraphic scoring system for grading severity of gastro-esophageal reflux on 99mTc sulfur colloid gastro-esophageal reflux scintigraphy: A prospective study of 39 cases with pre and post treatment assessment.

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Puranik, Ameya D; Nair, Gopinathan; Aggarwal, Rajiv; Bandyopadhyay, Abhijit; Shinto, Ajit; Zade, Anand

2013-04-01

The study aimed at developing a scoring system for scintigraphic grading of gastro-esophageal reflux (GER), on gastro-esophageal reflux scintigraphy (GERS) and comparison of clinical and scintigraphic scores, pre- and post-treatment. A total of 39 cases with clinically symptomatic GER underwent 99mTc sulfur colloid GERS; scores were assigned based on the clinical and scintigraphic parameters. Post domperidone GERS was performed after completion of treatment. Follow up GERS was performed and clinical and scintigraphic parameters were compared with baseline parameters. Paired t-test on pre and post domperidone treatment clinical scores showed that the decline in post-treatment scores was highly significant, with P value reflux and also for following children post-treatment.

16-Cyclopentadienyl tricarbonyl 99mTc 16-oxo-hexadecanoic acid: synthesis and evaluation of fatty acid metabolism in mouse myocardium.

Science.gov (United States)

Lee, Byung Chul; Kim, Dong Hyun; Lee, Iljung; Choe, Yearn Seong; Chi, Dae Yoon; Lee, Kyung-Han; Choi, Yong; Kim, Byung-Tae

2008-06-26

We synthesized 16-cyclopentadienyl tricarbonyl 99mTc 16-oxo-hexadecanoic acid (99mTc-CpTT-16-oxo-HDA, 1) and investigated its potential as a radiotracer for evaluating fatty acid metabolism in myocardium. Radiotracer 1 was synthesized in 22.6 +/- 6.3% decay-corrected yield by a double ligand transfer reaction between the ferrocene adduct of methyl hexadecanoate ( 2) and Na99mTcO 4 in the presence of Cr(CO)6 and CrCl3, followed by hydrolysis of the methyl ester group. Radiotracer 1 was found to be chemically stable (99% at 6 h) when incubated in human serum. A tissue distribution study in mice showed that high radioactivity accumulated in heart (9.03%ID/g at 1 min and 5.41%ID/g at 5 min postinjection) with rapid clearance and that heart to blood uptake ratios increased with time (2.13 at 5 min and 3.76 at 30 min postinjection). Metabolite analysis of the heart tissues using a simple extraction method showed that 99mTc-CpTT-4-oxo-butyric acid was detected as the major radioactive metabolite by HPLC, suggesting that 1 is metabolized to 99mTc-CpTT-4-oxo-butyric acid via beta-oxidation in myocardium.

Microbial impacts on 99mTc migration through sandstone under highly alkaline conditions relevant to radioactive waste disposal.

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Smith, Sarah L; Boothman, Christopher; Williams, Heather A; Ellis, Beverly L; Wragg, Joanna; West, Julia M; Lloyd, Jonathan R

2017-01-01

Geological disposal of intermediate level radioactive waste in the UK is planned to involve the use of cementitious materials, facilitating the formation of an alkali-disturbed zone within the host rock. The biogeochemical processes that will occur in this environment, and the extent to which they will impact on radionuclide migration, are currently poorly understood. This study investigates the impact of biogeochemical processes on the mobility of the radionuclide technetium, in column experiments designed to be representative of aspects of the alkali-disturbed zone. Results indicate that microbial processes were capable of inhibiting 99m Tc migration through columns, and X-ray radiography demonstrated that extensive physical changes had occurred to the material within columns where microbiological activity had been stimulated. The utilisation of organic acids under highly alkaline conditions, generating H 2 and CO 2 , may represent a mechanism by which microbial processes may alter the hydraulic conductivity of a geological environment. Column sediments were dominated by obligately alkaliphilic H 2 -oxidising bacteria, suggesting that the enrichment of these bacteria may have occurred as a result of H 2 generation during organic acid metabolism. The results from these experiments show that microorganisms are able to carry out a number of processes under highly alkaline conditions that could potentially impact on the properties of the host rock surrounding a geological disposal facility for intermediate level radioactive waste. Copyright © 2016. Published by Elsevier B.V.

Effect of mycorrhizal infection on root uptake by pine seedlings and redistribution of three contrasting radio-isotopes: {sup 85}Sr, {sup 95m}Tc and {sup 137}Cs

Energy Technology Data Exchange (ETDEWEB)

Plassard, C.; Ladeyn, I.; Staunton, S. [Institut National de Recherches Agronomiques (INRA), UMR Rhizosphere and Symbiose 34 - Montpellier (France)

2004-07-01

Mycorrhizal infection is known to improve phosphate nutrition and water supply of higher plants. It has been reported to both increase the uptake of potentially toxic pollutant elements and to protect plants against toxic effects. Little is known about the effect of mycorrhizal infection on the dynamics of radioactive pollutants in soil-plant systems. The aim of this study was to compare the root uptake and root-shoot transfer of three radio-isotopes with contrasting chemical properties ({sup 85}Sr, {sup 95m}Tc and {sup 137}Cs) in mycorrhizal and control, non mycorrhizal plants. The plant studied was Pinus pinaster and the associated ecto-mycorrhizal fungus was Rhizopogon roseolus (strain R18-2). Plants were grown under anoxic conditions for 3 months then transferred to thin layers of autoclaved soil and allowed to grow for four months. After this period, the rhizotrons were dismantled, and plant tissue analysed. Biomass, nutrient content (K, P, N, Ca) and activities of each isotope in roots, shoots and stems were measured, and the degree of mycorrhizal infection assessed. The transfer factors decreased in the order Tc>Sr>Cs as expected from the degree of immobilisation by soil. No effect of mycorrhizal infection on root uptake was observed for Sr. Shoot activity concentration of Tc was decreased by mycorrhizal infection but root uptake correlated well with mycelial soil surface area. In contrast, Cs shoot activity was greater in mycorrhizal than control plants. The uptake and root to shoot distribution shall be discussed in relation to nutrient dynamics. (author)

Functional discrepancy between two liver lobes after hemilobe biliary drainage in patients with jaundice and bile duct cancer: an appraisal using (99m)Tc-GSA SPECT/CT fusion imaging.

Science.gov (United States)

Sumiyoshi, Tatsuaki; Shima, Yasuo; Okabayashi, Takehiro; Noda, Yoshihiro; Hata, Yasuhiro; Murata, Yoriko; Kozuki, Akihito; Tokumaru, Teppei; Nakamura, Toshio; Uka, Kiminori

2014-11-01

To determine the functional discrepancy between the two liver lobes using technetium 99m ((99m)Tc) diethylenetriamine-pentaacetic acid-galactosyl human serum albumin ( GSA diethylenetriamine-pentaacetic acid-galactosyl human serum albumin ) single photon emission computed tomography (SPECT)/computed tomography (CT) fusion imaging following preoperative biliary drainage and portal vein embolization ( PVE portal vein embolization ) in patients with jaundice who have bile duct cancer ( BDC bile duct cancer ). This retrospective study was approved by the institutional review board, with waiver of informed consent. Preoperative (99m)Tc- GSA diethylenetriamine-pentaacetic acid-galactosyl human serum albumin SPECT/CT fusion images from 32 patients with extrahepatic BDC bile duct cancer were retrospectively reviewed. Patients were classified into four groups according to the extent of biliary drainage and presence of a preoperative right PVE portal vein embolization : right lobe drainage group (right drainage), bilateral lobe drainage group (bilateral drainage), left lobe drainage group (left drainage), and left lobe drainage with right PVE portal vein embolization group (left drainage with right PVE portal vein embolization ). Percentage volume and percentage function were measured in each lobe using fusion imaging. The ratio between percentage function and percentage volume (the function-to-volume ratio) was calculated for each lobe, and the results were compared among the four groups. Statistical analysis was performed with Wilcoxon signed-rank tests and Mann-Whitney U tests. The median values for the function-to-volume ratio in the right drainage, bilateral drainage, left drainage, and left drainage with right PVE portal vein embolization group were 1.12, 1.05, 1.02, and 0.81 in the right lobe; and 0.51, 0.88, 0.96, and 1.17 in the left lobe. Significant differences in the function-to-volume ratio were observed among the four groups (right drainage vs bilateral

Predicting Multiple Functions of Sustainable Flood Retention Basins under Uncertainty via Multi-Instance Multi-Label Learning

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Qinli Yang

2015-03-01

Full Text Available The ambiguity of diverse functions of sustainable flood retention basins (SFRBs may lead to conflict and risk in water resources planning and management. How can someone provide an intuitive yet efficient strategy to uncover and distinguish the multiple potential functions of SFRBs under uncertainty? In this study, by exploiting both input and output uncertainties of SFRBs, the authors developed a new data-driven framework to automatically predict the multiple functions of SFRBs by using multi-instance multi-label (MIML learning. A total of 372 sustainable flood retention basins, characterized by 40 variables associated with confidence levels, were surveyed in Scotland, UK. A Gaussian model with Monte Carlo sampling was used to capture the variability of variables (i.e., input uncertainty, and the MIML-support vector machine (SVM algorithm was subsequently applied to predict the potential functions of SFRBs that have not yet been assessed, allowing for one basin belonging to different types (i.e., output uncertainty. Experiments demonstrated that the proposed approach enables effective automatic prediction of the potential functions of SFRBs (e.g., accuracy >93%. The findings suggest that the functional uncertainty of SFRBs under investigation can be better assessed in a more comprehensive and cost-effective way, and the proposed data-driven approach provides a promising method of doing so for water resources management.

Estimation of a monotone percentile residual life function under random censorship.

Science.gov (United States)

Franco-Pereira, Alba M; de Uña-Álvarez, Jacobo

2013-01-01

In this paper, we introduce a new estimator of a percentile residual life function with censored data under a monotonicity constraint. Specifically, it is assumed that the percentile residual life is a decreasing function. This assumption is useful when estimating the percentile residual life of units, which degenerate with age. We establish a law of the iterated logarithm for the proposed estimator, and its n-equivalence to the unrestricted estimator. The asymptotic normal distribution of the estimator and its strong approximation to a Gaussian process are also established. We investigate the finite sample performance of the monotone estimator in an extensive simulation study. Finally, data from a clinical trial in primary biliary cirrhosis of the liver are analyzed with the proposed methods. One of the conclusions of our work is that the restricted estimator may be much more efficient than the unrestricted one. © 2012 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Toe clearance and velocity profiles of young and elderly during walking on sloped surfaces

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Begg Rezaul K

2010-04-01

Full Text Available Abstract Background Most falls in older adults are reported during locomotion and tripping has been identified as a major cause of falls. Challenging environments (e.g., walking on slopes are potential interventions for maintaining balance and gait skills. The aims of this study were: 1 to investigate whether or not distributions of two important gait variables [minimum toe clearance (MTC and foot velocity at MTC (VelMTC] and locomotor control strategies are altered during walking on sloped surfaces, and 2 if altered, are they maintained at two groups (young and elderly female groups. Methods MTC and VelMTC data during walking on a treadmill at sloped surfaces (+3°, 0° and -3° were analysed for 9 young (Y and 8 elderly (E female subjects. Results MTC distributions were found to be positively skewed whereas VelMTC distributions were negatively skewed for both groups on all slopes. Median MTC values increased (Y = 33%, E = 7% at negative slope but decreased (Y = 25%, E = 15% while walking on the positive slope surface compared to their MTC values at the flat surface (0°. Analysis of VelMTC distributions also indicated significantly (p th percentile (Q1 values in the elderly at all slopes. Conclusion The young displayed a strong positive correlation between MTC median changes and IQR (interquartile range changes due to walking on both slopes; however, such correlation was weak in the older adults suggesting differences in control strategies being employed to minimize the risk of tripping.

Chemi- vs physisorption in the radical functionalization of single-walled carbon nanotubes under microwaves

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Victor Mamane

2014-04-01

Full Text Available The effect of microwaves on the functionalization of single-walled carbon nanotubes (SWNTs by the diazonium method was studied. The usage of a new approach led to the identification of the strength of the interaction (physical or chemical between the functional groups and the carbon nanotube surface. Moreover, the nature (chemical formula of the adsorbed/grafted functional groups was determined. According to thermogravimetric analysis coupled with mass spectrometry and Raman spectroscopy, the optimal functionalization level was reached after 5 min of reaction. Prolonged reaction times can lead to undesired reactions such as defunctionalization, solvent addition and polymerization of the grafted functions. The strength (chemi- vs physisorption of the bonds between the grafted functional groups and the SWNTs is discussed showing the occurrence of physical adsorption as a consequence of defunctionalization after 15 min of reaction under microwaves. Several chemical mechanisms of grafting could be identified, and it was possible to distinguish conditions leading to the desired chemical grafting from those leading to undesired reactions such as physisorption and polymerization.

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

Is basal ultrasensitive measurement of calcitonin capable of substituting for the pentagastrin-stimulation test?

Science.gov (United States)

Pina, Géraldine; Dubois, Séverine; Murat, Arnaud; Berger, Nicole; Niccoli, Patricia; Peix, Jean-Louis; Cohen, Régis; Guillausseau, Claudine; Charrie, Anne; Chabre, Olivier; Cornu, Catherine; Borson-Chazot, Françoise; Rohmer, Vincent

2013-03-01

To evaluate a second-generation assay for basal serum calcitonin (CT) measurements compared with the pentagastrin-stimulation test for the diagnosis of inherited medullary thyroid carcinoma (MTC) and the follow-up of patients with MTC after surgery. Recent American Thyroid Association recommendations suggest the use of basal CT alone to diagnose and assess follow-up of MTC as the pentagastrin (Pg) test is unavailable in many countries. Multicentric prospective study. A total of 162 patients with basal CT basal and Pg-stimulated CT measurements using a second-generation assay with 5-ng/l functional sensitivity. Ninety-five per cent of patients with basal CT ≥ 5 ng/l and 25% of patients with basal CT stimulation test (Pg CT >10 ng/l). Compared with the reference Pg test, basal CT ≥ 5 ng/l had 99% specificity, a 95%-positive predictive value but only 35% sensitivity (P basal CT instead of the previously used 10-ng/l threshold. The ultrasensitive CT assay reduces the false-negative rate of basal CT measurements when diagnosing familial MTC and in postoperative follow-up compared with previously used assays. However, its sensitivity to detect C-cell disease remains lower than that of the Pg-stimulation test. © 2012 Blackwell Publishing Ltd.

The quantization of the attention function under a Bayes information theoretic model

International Nuclear Information System (INIS)

Wynn, H.P.; Sebastiani, P.

2001-01-01

Bayes experimental design using entropy, or equivalently negative information, as a criterion is fairly well developed. The present work applies this model but at a primitive level in statistical sampling. It is assumed that the observer/experimentor is allowed to place a window over the support of a sampling distribution and only 'pay for' observations that fall in this window. The window can be modeled with an 'attention function', simply the indicator function of the window. The understanding is that the cost of the experiment is only the number of paid for observations: n. For fixed n and under the information model it turns out that for standard problems the optimal structure for the window, in the limit amongst all types of window including disjoint regions, is discrete. That is to say it is optimal to observe the world (in this sense) through discrete slits. It also shows that in this case Bayesians with different priors will receive different samples because typically the optimal attention windows will be disjoint. This property we refer to as the quantization of the attention function

Radionuclides used in nuclear medicine ({sup 131}I, {sup 99m}Tc e {sup 99}Tc) in sewage system and in the marine environment of Rio de Janeiro city, RJ, Brazil; Radionuclideos usados em medicina nuclear ({sup 131}I, {sup 99m}Tc e {sup 99}Tc) no sistema de esgoto e no ambiente marinho da cidade do Rio de Janeiro, RJ

Energy Technology Data Exchange (ETDEWEB)

Sousa, Daniele Santos de

2014-08-01

The nuclear medicine is a specialty that uses radioisotopes for diagnostic or therapeutic purpose. In Brazil there are around 340 Nuclear Medicine Services (NMS), 27 of them, are located in the city of Rio de Janeiro. The most widely used radionuclides in the country are {sup 131}I and {sup 99m}Tc. The radionuclide {sup 99m}Tc decays to {sup 99}Tc, which is a beta emitter with a long half-life (10{sup 5} years). The aim of this study is to perform a survey to estimate the {sup 131}I and {sup 99}Tc discharged levels at the Canal do Cunha, the main pathways for environmental dispersion and evaluate the radiological impact to non-human biota and to the populations exposed to these radionuclides. The Alegria Station receives sewage from most clinics of Rio de Janeiro mid was therefore chosen as a study case. The station receives approximately 4.50 x 10{sup 5} Bq/year of {sup 99}Tc e 7.12 x 10{sup 12} Bq/year of {sup 131}I. After passing through all stages of treatment, the effluent is discharged into the Canal do Cunha and flows into the Guanabara Bay. To assess the radiological impact of these radionuclide discharges, a comparative study was made considering three computational models: the CROM, which is based on a model of the International Atomic Energy Agency (IAEA), the PC-CREAM, widely used by the European Union and the GENII, which is the most widely used model in the United States. Two exposure scenarios were considered: 1 - people that bathe directly in the discharge of the effluent; 2 - community living 1200 meters from the discharge point, bathing in the river and consuming local fish. Concentration and doses values for the scenarios according to the applicability of each computer code were estimated. The dose values at the discharge point were 7.47 x 10{sup -6}mSv for {sup 131}I and 2.87 x 10{sup -14} mSv for {sup 99}Tc, while for scenario II the value of the total dose was approximately 10{sup -1} mSv/year for {sup 131}I and 10{sup -10} mSv/year for {sup

19 CFR 0.1 - Customs revenue function regulations issued under the authority of the Departments of the...

Science.gov (United States)

2010-04-01

... the authority of the Departments of the Treasury and Homeland Security. 0.1 Section 0.1 Customs Duties... TRANSFERRED OR DELEGATED AUTHORITY § 0.1 Customs revenue function regulations issued under the authority of... authority to prescribe all CBP regulations relating to customs revenue functions, except that the Secretary...

THE FUNCTIONS OF THE CIVIL SOCIETY UNDER THE CONDITIONS OF MODERN RUSSIAN MODERNIZATION

Directory of Open Access Journals (Sweden)

Василий Вячеславович Рябев

2013-11-01

Full Text Available This article discusses the functions of the civil society in contemporary Russian realias. The purpose is to identify and classify the most important functions of the civil society under the conditions of comprehensive modern Russian modernization. The article presents the author's classification of the functions of the civil society, based on the analysis of significant studies of foreign and Russian researchers. Here is a detailed analysis of each function focused on the most relevant to a modern Russian society, the potential of Russian civil society is revealed dealing with following issues: the institutionalization of the civic activity, the anti-corruption policy, the consolidation of democratic forces, the formation of the legal culture. The conclusions can be used in studies related to the civil society, the specific mechanisms for dealing with current social issues by means of civic participation, presented in this article, may be the object of interest for government institutions.DOI: http://dx.doi.org/10.12731/2218-7405-2013-10-6

The effect of the adsorbate layer on the work function reduction of gold substrates under external electric fields

Science.gov (United States)

He, Xiang; Cheng, Feng; Chen, Zhao-Xu

2017-12-01

The interface interaction between the dimethyl sulfide (DMS) molecule and the gold substrate under external electric fields is investigated by density functional theory method. The polarized DMS adsorbate reduces the work function of the gold substrate while the induced substrate dipole upon the adsorption slightly increases the work function. The DMS layer partially shields the Au(111) substrate from the electric fields and the vacuum level of DMS/Au(111) shifts less than of Au(111) in consequence. Under electric fields pointing outward from the Au(111) surface, both the reduction of work function and the adsorption of DMS molecule are enhanced on the surface. We also suggest the possible application of the field-effect transistor (FET) sensor with gold gate for detecting DMS molecule by utilizing the reduction of substrate work function upon adsorption. The effects of coverage and electric field on the theoretical sensitivity of the sensor are also discussed.

Scintigraphic disagreement in the study of thyroid nodules using technetium 99m and iodine 131

International Nuclear Information System (INIS)

Planchon, C.A.

1977-01-01

116 patients with thyroid nodules, iso or hyperfixing, heterogeneous or scintigraphically indistinct after administration of pertechnetate 99mTc, were systematically re-examined with iodine 131. The results of this study are as follows: 1) 99mTc, while its advantages justify its extensive application, is an imperfect tracer and cannot replace iodine 131 altogether. In fact in 12% of the cases the results were conflicting. 2) The technological conditions may sometimes be to blame but the hypothesis of a special metabolic behavior of the nodule examined seems plausible in certain cases of disagreement (blocking of hormone synthesis and escape of non-hormonal iodine). 3) These observations correspond to no particular anatomo-clinical factors. The legitimate conclusion therefore is that the exclusive use of 99mTc could result in failure to recognise a non-functional nodule (1 case in about 10), a possibility not to be neglected because of the risk of cancer [fr

Observing trends in the functionalization of cnts using same oxidizing acids under two different conditions

International Nuclear Information System (INIS)

Aftab, S.

2013-01-01

Excellent electrical, mechanical, optical and thermal properties are attributed to carbon nanotubes. Carbon nanotubes need to be functionalized to form a homogeneous dispersion. In this work, catalytically produced carbon nanotubes have been functionalized under two different conditions using the same acid medium. The effect of the two reaction routes on the carbon nanotubes, in terms of the extent of covalent functionalization has been determined by several techniques. Scanning electron microscopy aided in the observation of their morphology and X-ray diffraction was used to ascertain their structure. Other analytical characterization tools employed were Fourier transform infrared spectroscopy, Zeta potential measurement, UV spectroscopy, Oxygen percentage analysis, Boehm's titration and visual dispersion. Results show that carbon nanotubes functionalized by refluxing in the acids are much better dispersed. (author)

Water Contact Angle Dependence with Hydroxyl Functional Groups on Silica Surfaces under CO2 Sequestration Conditions.

Science.gov (United States)

Chen, Cong; Zhang, Ning; Li, Weizhong; Song, Yongchen

2015-12-15

Functional groups on silica surfaces under CO2 sequestration conditions are complex due to reactions among supercritical CO2, brine and silica. Molecular dynamics simulations have been performed to investigate the effects of hydroxyl functional groups on wettability. It has been found that wettability shows a strong dependence on functional groups on silica surfaces: silanol number density, space distribution, and deprotonation/protonation degree. For neutral silica surfaces with crystalline structure (Q(3), Q(3)/Q(4), Q(4)), as silanol number density decreases, contact angle increases from 33.5° to 146.7° at 10.5 MPa and 318 K. When Q(3) surface changes to an amorphous structure, water contact angle increases 20°. Water contact angle decreases about 12° when 9% of silanol groups on Q(3) surface are deprotonated. When the deprotonation degree increases to 50%, water contact angle decreases to 0. The dependence of wettability on silica surface functional groups was used to analyze contact angle measurement ambiguity in literature. The composition of silica surfaces is complicated under CO2 sequestration conditions, the results found in this study may help to better understand wettability of CO2/brine/silica system.

Radiolabeling and physicochemical characterization of boron nitride nanotubes functionalized with glycol chitosan polymer

Energy Technology Data Exchange (ETDEWEB)

Soares, Daniel Cristian Ferreira; Ferreira, Tiago Hilario; Ferreira, Carolina de Aguiar; Sousa, Edesia Martins Barros de, E-mail: sousaem@cdtn.b [Centro de Desenvolvimento da Tecnologia Nuclear (CDTN/CNEN-MG) Belo Horizonte, MG (Brazil). Lab. de Materiais Nanoestruturados para Bioaplicacoes; Cardoso, Valbert Nascimento, E-mail: cardosov@farmacia.ufmg.b [Universidade Federal de Minas Gerais (UFMG), Belo Horizonte, MG (Brazil). Fac. de Farmacia

2011-07-01

In the last years, some nanostructured systems has proposed as new drugs and radioisotopes delivery systems, aiming the diagnosis and treatment of many diseases, including the cancer. Among these systems, the Boron Nitride Nanotubes (BNNTs) showed adequate characteristics to be applied in biomedical area, due to its high stability and considerable biocompatibility. However, due to its hydrophobic characteristics, these applications are limited and its behavior in vivo (guinea pigs) is unexplored yet. Seeking to overcome this problems, in the present work, we functionalized the BNNTs (noncovalent wrapped) with glycol chitosan (GC), a biocompatible and stable polymer, in order to disperse it in water. The results showed that BNNTs were well dispersed in water with mean size and polydispersity index suitable to conduct biodistribution studies in mice. The nanostructures were physicochemical and morphologically characterized by Scanning Electron Microscopy (SEM), X-ray diffraction (XRD) and Raman Spectroscopy. The results revealed that the functionalization process with glycol chitosan was obtained with successfully on BNNTs surface. Furthermore, we developed a radiolabeling protocol with {sup 99m}Tc radioisotope in functionalized BNNTs, aiming in future, to conduct image biodistribution studies in mice. The results revealed that the nanotubes were radiolabeled with radiochemical purity above of 90%, being considered suitable to scintigraphic image acquisition. (author)

Globally COnstrained Local Function Approximation via Hierarchical Modelling, a Framework for System Modelling under Partial Information

DEFF Research Database (Denmark)

Øjelund, Henrik; Sadegh, Payman

2000-01-01

be obtained. This paper presents a new approach for system modelling under partial (global) information (or the so called Gray-box modelling) that seeks to perserve the benefits of the global as well as local methodologies sithin a unified framework. While the proposed technique relies on local approximations......Local function approximations concern fitting low order models to weighted data in neighbourhoods of the points where the approximations are desired. Despite their generality and convenience of use, local models typically suffer, among others, from difficulties arising in physical interpretation...... simultaneously with the (local estimates of) function values. The approach is applied to modelling of a linear time variant dynamic system under prior linear time invariant structure where local regression fails as a result of high dimensionality....

Estimation in adults of the glomerular filtration rate in [99mTc] DTPA renography - the rate constant method

International Nuclear Information System (INIS)

Carlsen, Ove

2004-01-01

The purpose of this study was to design an alternative and robust method for estimation of glomerular filtration rate (GFR) in [ 99 mTc]-diethylenetriaminepentaacetic acid ([ 99 mTc] -DTPA renography with a reliability not significantly lower than that of the conventional Gates' method. Methods: The method is based on renographies lasting 40 min in which regions of interest (ROIs) are manually created over selected parts of certain blood pools (e.g. heart, lungs, spleen, and liver). For each ROI the corresponding time-activity curve (TAC) was generated, decay corrected and exposed to a monoexponential fit in the time interval 10 to 40 min postinjection. The rate constant in min-1 of the monoexponential fit was denoted BETA. Following an iterative procedure comprising usually 5-10 manually created ROIs, the monoexponential fit with the maximum rate constant (BETA max ) was used for estimation of GFR. Results: In a patient material of 54 adult subjects in whom GFR was determined with multiple or one sample techniques with [ 51 Cr]-ethylenediaminetetraacetic acid ([ 51 Cr]-EDTA) the regression curve of standard GFR (GFR std ) (i.e. GFR adjusted to 1.73 m 2 body surface area) showed a close, non-linear relationship with BETA max with a correlation coefficient of 95%. The standard errors of estimate (SEE) were 6.6, 10.6 and 16.8 for GFR std equal to 30, 60, and 120 ml/(min .73 m 2 ), respectively. The corresponding SEE values for almost the same patient material using Gates' method were 8.4, 11.9, and 16.8 ml/(min 1.73 m 2 ). Conclusions: The alternative rate constant method yields estimates of GFR std with SEE values equal to or slightly smaller than in Gates' method. The two methods provide statistically uncorrelated estimates of GFR std . Therefore, pooled estimates of GFR std can be calculated with SEE values approximately 1.41 times smaller than those mentioned above. The reliabilities of the pooled estimate of GFR std separately and of the multiple samples method

Diagnosis of medullary thyroid cancer and prognostic factors of disease aggressiveness

Directory of Open Access Journals (Sweden)

D O Gazizova

2013-12-01

Full Text Available In the study were enrolled 137 patients with medullary thyroid cancer (MTC. Low 35%-sensitivity of FNAC and high accuracy of basal calcitonin in MTC diagnostics were found. Mutation analysis of the RET pro- tooncogene in familial and sporadic MTC, RAS -gene in sporadic MTC were done. The correlation between type of the mutation and disease aggressiveness was found.

Osteocalcin protects pancreatic beta cell function and survival under high glucose conditions

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Kover, Karen, E-mail: kkover@cmh.edu [Division of Endocrine/Diabetes, Children' s Mercy Hospital & Clinics, Kansas City, MO 64108 (United States); University of Missouri-Kansas City School of Medicine, Kansas City, MO 64108 (United States); Yan, Yun; Tong, Pei Ying; Watkins, Dara; Li, Xiaoyu [Division of Endocrine/Diabetes, Children' s Mercy Hospital & Clinics, Kansas City, MO 64108 (United States); University of Missouri-Kansas City School of Medicine, Kansas City, MO 64108 (United States); Tasch, James; Hager, Melissa [Kansas City University Medical Biosciences, Kansas City, MO (United States); Clements, Mark; Moore, Wayne V. [Division of Endocrine/Diabetes, Children' s Mercy Hospital & Clinics, Kansas City, MO 64108 (United States); University of Missouri-Kansas City School of Medicine, Kansas City, MO 64108 (United States)

2015-06-19

Diabetes is characterized by progressive beta cell dysfunction and loss due in part to oxidative stress that occurs from gluco/lipotoxicity. Treatments that directly protect beta cell function and survival in the diabetic milieu are of particular interest. A growing body of evidence suggests that osteocalcin, an abundant non-collagenous protein of bone, supports beta cell function and proliferation. Based on previous gene expression data by microarray, we hypothesized that osteocalcin protects beta cells from glucose-induced oxidative stress. To test our hypothesis we cultured isolated rat islets and INS-1E cells in the presence of normal, high, or high glucose ± osteocalcin for up to 72 h. Oxidative stress and viability/mitochondrial function were measured by H{sub 2}O{sub 2} assay and Alamar Blue assay, respectively. Caspase 3/7 activity was also measured as a marker of apoptosis. A functional test, glucose stimulated insulin release, was conducted and expression of genes/protein was measured by qRT-PCR/western blot/ELISA. Osteocalcin treatment significantly reduced high glucose-induced H{sub 2}O{sub 2} levels while maintaining viability/mitochondrial function. Osteocalcin also significantly improved glucose stimulated insulin secretion and insulin content in rat islets after 48 h of high glucose exposure compared to untreated islets. As expected sustained high glucose down-regulated gene/protein expression of INS1 and BCL2 while increasing TXNIP expression. Interestingly, osteocalcin treatment reversed the effects of high glucose on gene/protein expression. We conclude that osteocalcin can protect beta cells from the negative effects of glucose-induced oxidative stress, in part, by reducing TXNIP expression, thereby preserving beta cell function and survival. - Highlights: • Osteocalcin reduces glucose-induced oxidative stress in beta cells. • Osteocalcin preserves beta cell function and survival under stress conditions. • Osteocalcin reduces glucose

Osteocalcin protects pancreatic beta cell function and survival under high glucose conditions

International Nuclear Information System (INIS)

Kover, Karen; Yan, Yun; Tong, Pei Ying; Watkins, Dara; Li, Xiaoyu; Tasch, James; Hager, Melissa; Clements, Mark; Moore, Wayne V.

2015-01-01

Diabetes is characterized by progressive beta cell dysfunction and loss due in part to oxidative stress that occurs from gluco/lipotoxicity. Treatments that directly protect beta cell function and survival in the diabetic milieu are of particular interest. A growing body of evidence suggests that osteocalcin, an abundant non-collagenous protein of bone, supports beta cell function and proliferation. Based on previous gene expression data by microarray, we hypothesized that osteocalcin protects beta cells from glucose-induced oxidative stress. To test our hypothesis we cultured isolated rat islets and INS-1E cells in the presence of normal, high, or high glucose ± osteocalcin for up to 72 h. Oxidative stress and viability/mitochondrial function were measured by H 2 O 2 assay and Alamar Blue assay, respectively. Caspase 3/7 activity was also measured as a marker of apoptosis. A functional test, glucose stimulated insulin release, was conducted and expression of genes/protein was measured by qRT-PCR/western blot/ELISA. Osteocalcin treatment significantly reduced high glucose-induced H 2 O 2 levels while maintaining viability/mitochondrial function. Osteocalcin also significantly improved glucose stimulated insulin secretion and insulin content in rat islets after 48 h of high glucose exposure compared to untreated islets. As expected sustained high glucose down-regulated gene/protein expression of INS1 and BCL2 while increasing TXNIP expression. Interestingly, osteocalcin treatment reversed the effects of high glucose on gene/protein expression. We conclude that osteocalcin can protect beta cells from the negative effects of glucose-induced oxidative stress, in part, by reducing TXNIP expression, thereby preserving beta cell function and survival. - Highlights: • Osteocalcin reduces glucose-induced oxidative stress in beta cells. • Osteocalcin preserves beta cell function and survival under stress conditions. • Osteocalcin reduces glucose-induced TXNIP

The Functional Task Test (FTT): An Interdisciplinary Testing Protocol to Investigate the Factors Underlying Changes in Astronaut Functional Performance

Science.gov (United States)

Bloomberg, J. J.; Lawrence, E. L.; Arzeno, N. M.; Buxton, R. E.; Feiveson, A. H.; Kofman, I. S.; Lee, S. M. C.; Mulavara, A. P.; Peters, B. T.; Platts. S. H.;

Surface functionalization of SPR chip for specific molecular interaction analysis under flow condition

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Tao Ma

2017-03-01

Full Text Available Surface functionalization of sensor chip for probe immobilization is crucial for the biosensing applications of surface plasmon resonance (SPR sensors. In this paper, we report a method circulating the dopamine aqueous solution to coat polydopamine film on sensing surface for surface functionalization of SPR chip. The polydopamine film with available thickness can be easily prepared by controlling the circulation time and the biorecognition elements can be immobilized on the polydopamine film for specific molecular interaction analysis. These operations are all performed under flow condition in the fluidic system, and have the advantages of easy implementation, less time consuming, and low cost, because the reagents and devices used in the operations are routinely applied in most laboratories. In this study, the specific absorption between the protein A probe immobilized on the sensing surface and human immunoglobulin G in the buffer is monitored based on this surface functionalization strategy to demonstrated its feasibility for SPR biosensing applications.

[Functional impairment and radiologic fasciitis under erlotinib therapy].

Science.gov (United States)

Osdoit, S; Wierzbicka, E; Guillet, G

2011-01-01

Targeted molecules are recent and valuable weapons in the management of certain cancers. Among them, erlotinib is an inhibitor of epidermal growth factor receptor approved in non-small lung cancer and pancreatic cancer after failure of first line treatment. Erlotinib is responsible for many cutaneous side effects. We report a case of acute symptomatic fasciitis that has occurred during erlotinib therapy. To our knowledge it is the first case described. A 56-year-old man was treated with erlotinib for a metastatic non-small lung adenocarcinoma. Shortly after the treatment by erlotinib was introduced, he had a severe acneiform rash resistant to doxycycline treatment. After a year of treatment, he presented intense pain in the legs with functional impairment. Medical imaging confirmed fasciitis. It regressed along with the rash after using strong topical corticosteroids during ten days. Besides bacterial fasciitis, inflammatory and oedematous fasciitis have varied aetiologies. The occurrence of a documented fasciitis during anti EGFR-therapy is original and raises the question of underlying mechanism. We suggest three pathophysiological mechanisms: spreading by contiguity; paraneoplastic fasciitis, or specific lesion of the fascia due to anti-EGFR. Copyright © 2011 Elsevier Masson SAS. All rights reserved.

Nitrate-dependent shoot sodium accumulation and osmotic functions of sodium in Arabidopsis under saline conditions.

Science.gov (United States)

Álvarez-Aragón, Rocío; Rodríguez-Navarro, Alonso

2017-07-01

Improving crop plants to be productive in saline soils or under irrigation with saline water would be an important technological advance in overcoming the food and freshwater crises that threaten the world population. However, even if the transformation of a glycophyte into a plant that thrives under seawater irrigation was biologically feasible, current knowledge about Na + effects would be insufficient to support this technical advance. Intriguingly, crucial details about Na + uptake and its function in the plant have not yet been well established. We here propose that under saline conditions two nitrate-dependent transport systems in series that take up and load Na + into the xylem constitute the major pathway for the accumulation of Na + in Arabidopsis shoots; this pathway can also function with chloride at high concentrations. In nrt1.1 nitrate transport mutants, plant Na + accumulation was partially defective, which suggests that NRT1.1 either partially mediates or modulates the nitrate-dependent Na + transport. Arabidopsis plants exposed to an osmotic potential of -1.0 MPa (400 mOsm) for 24 h showed high water loss and wilting in sorbitol or Na/MES, where Na + could not be accumulated. In contrast, in NaCl the plants that accumulated Na + lost a low amount of water, and only suffered transitory wilting. We discuss that in Arabidopsis plants exposed to high NaCl concentrations, root Na + uptake and tissue accumulation fulfil the primary function of osmotic adjustment, even if these processes lead to long-term toxicity. © 2017 The Authors The Plant Journal © 2017 John Wiley & Sons Ltd.

The role of plant functional trade-offs for biodiversity changes and biome shifts under scenarios of global climatic change

Directory of Open Access Journals (Sweden)

B. Reu

2011-05-01

Full Text Available The global geographic distribution of biodiversity and biomes is determined by species-specific physiological tolerances to climatic constraints. Current vegetation models employ empirical bioclimatic relationships to predict present-day vegetation patterns and to forecast biodiversity changes and biome shifts under climatic change. In this paper, we consider trade-offs in plant functioning and their responses under climatic changes to forecast and explain changes in plant functional richness and shifts in biome geographic distributions.

The Jena Diversity model (JeDi simulates plant survival according to essential plant functional trade-offs, including ecophysiological processes such as water uptake, photosynthesis, allocation, reproduction and phenology. We use JeDi to quantify changes in plant functional richness and biome shifts between present-day and a range of possible future climates from two SRES emission scenarios (A2 and B1 and seven global climate models using metrics of plant functional richness and functional identity.

Our results show (i a significant loss of plant functional richness in the tropics, (ii an increase in plant functional richness at mid and high latitudes, and (iii a pole-ward shift of biomes. While these results are consistent with the findings of empirical approaches, we are able to explain them in terms of the plant functional trade-offs involved in the allocation, metabolic and reproduction strategies of plants. We conclude that general aspects of plant physiological tolerances can be derived from functional trade-offs, which may provide a useful process- and trait-based alternative to bioclimatic relationships. Such a mechanistic approach may be particularly relevant when addressing vegetation responses to climatic changes that encounter novel combinations of climate parameters that do not exist under contemporary climate.

Bayesian Estimation of the Scale Parameter of Inverse Weibull Distribution under the Asymmetric Loss Functions

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Farhad Yahgmaei

2013-01-01

Full Text Available This paper proposes different methods of estimating the scale parameter in the inverse Weibull distribution (IWD. Specifically, the maximum likelihood estimator of the scale parameter in IWD is introduced. We then derived the Bayes estimators for the scale parameter in IWD by considering quasi, gamma, and uniform priors distributions under the square error, entropy, and precautionary loss functions. Finally, the different proposed estimators have been compared by the extensive simulation studies in corresponding the mean square errors and the evolution of risk functions.

Better executive function under stress mitigates the effects of recent life stress exposure on health in young adults.

Science.gov (United States)

Shields, Grant S; Moons, Wesley G; Slavich, George M

2017-01-01

Executive function is a neuropsychological construct that enables controlled cognitive processing, which has been hypothesized to enhance individuals' resilience to stress. However, little empirical work has directly examined how executive function under different conditions mitigates the negative effects of stress exposure on health. To address this issue, we recruited 110 healthy young adults and assessed their recent life stress exposure, executive function in either a stressful or non-stressful context, and current health complaints. Based on existing research, we hypothesized that individuals exhibiting better executive function following a laboratory-based stressor (but not a control task) would demonstrate weaker associations between recent stress exposure and health because they perceived recent life stressors as being less severe. Consistent with this hypothesis, better executive function during acute stress, but not in the absence of stress, was associated with an attenuated link between participants' recent life stress exposure and their current health complaints. Moreover, this attenuating effect was mediated by lesser perceptions of stressor severity. Based on these data, we conclude that better executive function under stress is associated with fewer health complaints and that these effects may occur by reducing individuals' perceptions of stressor severity. The data thus suggest the possibility of reducing stress-related health problems by enhancing executive function.

Hot spot(s) of the lung in technetium-99m albumin colloid liver-spleen scintigraphy: case report

International Nuclear Information System (INIS)

Shih, W.J.; Brandenburg, S.; Coupal, J.J.; Sullivan, J.D.; Beeler, J.A.; Magoun, S.; Ryo, U.Y.

1988-01-01

The authors replaced /sup 99m/Tc albumin colloid for /sup 99m/Tc sulfur colloid as a radiopharmaceutical for liver-spleen imaging and found two instances of hot spot(s) in the lung. The preparation procedure of albumin colloid is easier and more convenient as compared to that of sulfur colloid. Whereas replacement of /sup 99m/Tc sulfur colloid by /sup 99m/Tc albumin colloid is inevitable, it should be emphasized that one should avoid blood withdrawal in the syringe containing albumin colloid to prevent formation of clot(s) during the venous puncture for /sup 99m/Tc albumin colloid

Incremental value of combined 99MTc tetrofosmin parathyroid scintigraphy, rapid intra operative PTH assays and minimally invasive radio-guided surgery (MIRS) in optimizing parathyroidectomies

International Nuclear Information System (INIS)

Padma, S.; Kumar, S.; Babu, T.; Kumar, H.; Nair, V.; Nair, G.K.

2004-01-01

Objective: Aim of our study was to evaluate incremental diagnostic value of 99mTc Tetrofosmin parathyroid SPECT (TPSPECT), rapid intra operative quick parathyroid hormone measurement (QPTH) combined with radio guidance provided by scintillation probe (Minimally Invasive Radio guided Surgery MIRS) in parathyroid surgeries. While TPSPECT is an established investigation in preoperative workup of hyperparathyroidism patients , MIRS is a relatively new concept in Indian subcontinent. Methods: 29 pts (M: F = 18: 11), age range 16- 65 yrs (mean 41+ 9 yrs) having clinical and biochemical hyperparathyroidism underwent TPSPECT between Jan 02 -04, using 20 mci IV 99mTc Tetrofosmin. Pts with familial hyperparathyroidism , previous nodular goiters and previous neck irradiation were excluded from study. Scintigraphy comprised of immediate, delayed planar and SPECT imaging of neck and chest. Imagewise abnormal, persistent tracer uptake was considered positive for adenoma and diffuse uptake for hyperplasia. 26 pts underwent exploration (22 adenomas and 4 hyperplasias).18 pts had benefit of intraoperative QPTH. A select group (after Dec 2003) i.e. 9 pts got the assistance of radioguided probing. Peroperatively NM physician used cordless handheld gamma probe (Gamma Finder, World of Medicine, Germany) in neck and mediastinum to detect parathyroid adenoma / hyperplasias. A five fold increase in radioactive counts perceived by probe when compared to background was considered positive for parathyroid adenoma / hyperplasia. If PTH levels fell from baseline by at least 50%, the surgery was concluded as complete. Results: In all 22 pts suspected to have primary hyperparathyroidism TPSPECT identified adenomas (100 % sensitivity). While planar imaging had a sensitivity of 90.1% (20/22 pts), SPECT identified the adenoma in all pts. Interestingly only 3/22 pts had ectopic glands while 5 had more than one adenomas. The most commonly involved gland was left inferior. In secondary

Functional brain networks underlying detection and integration of disconfirmatory evidence.

Science.gov (United States)

Lavigne, Katie M; Metzak, Paul D; Woodward, Todd S

2015-05-15

.g., 17s after trial onset) the hemodynamic responses associated with all three networks were simultaneously active. These findings highlight distinct cognitive processes and corresponding functional brain networks underlying stages of disconfirmatory evidence integration, and demonstrate the power of multivariate and multi-experiment methodology in cognitive neuroscience. Copyright © 2015 Elsevier Inc. All rights reserved.

77 FR 42945 - Delegation of Certain Functions Under Section 570(e) of the Foreign Operations, Export Financing...

Science.gov (United States)

2012-07-20

... Certain Functions Under Section 570(e) of the Foreign Operations, Export Financing, and Related Programs... the Foreign Operations, Export Financing, and Related Programs Appropriations Act, 1997 (Public Law...

Radiolabeling of Ceftriaxone with 99mTc as a Targeting Radiopharmaceutical for Staphylococcus Aureus Detection in Mouse Model

International Nuclear Information System (INIS)

Fazli, A.; Saluti, M.; Ahmadi, Gh.; Mirshojaei, F.; Mazidi, M.; Heydari, Z.

2012-01-01

Bacterial infection is one of the major causes of morbidity and mortality especially in developing countries. Nuclear medicine has an important role in helping the diagnosis of deep-seated infections by developing more specific radiopharmaceuticals. The aim of this study was to evaluate 99mTc-labeling ceftriaxone as a new radiopharmaceutical for Staphylococcus aureus infection imaging in nuclear medicine. Radiolabeling of ceftriaxone was carried out by adding 370 MBq of 99mTc to 10 mg of ceftriaxone in the presence of 50 μg of SnCl 2 .2H 2 O at pH=5. The radiochemical purity and stability tests at room temperature and human blood serum were evaluated with ITLC. Intramuscular infection was induced by injection of Staphylococcus aureus into the left thigh muscle of the mice. The biodistribution of 99mTc-ceftriaxone was studied in normal and infected mice at various times post-injection. Radiochemical purity of the product was 94.5±5.4% with a good stability at room temperature and human serum, 80.6% and 71.2% after 24 h, respectively. The biodistribution studies showed the localization of 99mTc-ceftriaxone at the site of infection with high sensitivity without any significant accumulation in vital organs. Due to the ease of 99mTc-ceftriaxone conjugation method, high labeling efficiency, and high uptake in the infected muscle, it may provide a promising candidate as a targeting radiopharmaceutical for imaging infectious foci due to Staphylococcus aureus in nuclear medicine.

Magnetization transfer contrast MR imaging of the knee at 0.3 T

International Nuclear Information System (INIS)

Yoshioka, Hiroshi; Onaya, Hiroaki; Niitsu, Mamoru; Anno, Izumi; Itai, Yuji; Nishimura, Hiroshi; Kajiyama, Koji; Masuda, Tomonori; Nakajima, Kotaro.

1994-01-01

It has been reported that magnetization transfer contrast (MTC) images were effective in evaluating the articular cartilage. However, only one in vivo study of the articular cartilage in the knee has been demonstrated at 1.5T. The purpose of this study was to evaluate the optimal off-resonance MTC pulse at 0.3T MR imager and assess its clinical usefulness. Five normal volunteers and eleven patients with suspected knee injuries were investigated using off-resonance sinc, gaussian, constant shaped irradiation pulses. All MTC images revealed higher contrast and contrast-to-noise (C/N) ratio between articular cartilage and external reference (saline) in the normal volunteers' knee than conventional gradient recalled echo images. MTC images with the gaussian or sinc shaped pulse were judged superior to those with constant wave pulse because the former images showed a fewer artifact with lower specific absorption rate than the latter images. The sinc MTC images were performed with the lowest SAR. The gaussian MTC images revealed better contrast and C/N between articular cartilage and joint fluid than the sinc MTC images in patients. 3D MTC images using Guassian pulse were also performed within a clinically tolerable imaging time (13 min 39 sec). Thus, MTC images in the knee at 0.3T using off-resonance pulse may be effective to assess knee injury due to better contrast between articular cartilage and joint fluid. (author)

Investigation of activation cross section data of alpha particle induced nuclear reaction on molybdenum up to 40 MeV: Review of production routes of medically relevant {sup 97,103}Ru

Energy Technology Data Exchange (ETDEWEB)

Tárkányi, F. [Institute of Nuclear Research of the Hungarian Academy of Sciences, Debrecen (Hungary); Hermanne, A., E-mail: aherman@vub.ac.be [Cyclotron Laboratory, Vrije Universiteit Brussel, Brussels (Belgium); Ditrói, F.; Takács, S. [Institute of Nuclear Research of the Hungarian Academy of Sciences, Debrecen (Hungary); Ignatyuk, A. [Institute of Physics and Power Engineering (IPPE), Obninsk (Russian Federation)

2017-05-15

The main goals of this investigations were to expand and consolidate reliable activation cross-section data for the {sup nat}Mo(α,x) reactions in connection with production of medically relevant {sup 97,103}Ru and the use of the {sup nat}Mo(α,x){sup 97}Ru reaction for monitoring beam parameters. The excitation functions for formation of the gamma-emitting radionuclides {sup 94}Ru, {sup 95}Ru, {sup 97}Ru, {sup 103}Ru, {sup 93m}Tc, {sup 93g}Tc(m+), {sup 94m}Tc, {sup 94g}Tc, {sup 95m}Tc, {sup 95g}Tc, {sup 96g}Tc(m+), {sup 99m}Tc, {sup 93m}Mo, {sup 99}Mo(cum), {sup 90}Nb(m+) and {sup 88}Zr were measured up to 40 MeV alpha-particle energy by using the stacked foil technique and activation method. Data of our earlier similar experiments were re-evaluated and resulted in corrections on the reported results. Our experimental data were compared with critically analyzed literature data and with the results of model calculations, obtained by using the ALICE-IPPE, EMPIRE 3.1 (Rivoli) and TALYS codes (TENDL-2011 and TENDL-2015 on-line libraries). Nuclear data for different production routes of {sup 97}Ru and {sup 103}Ru are compiled and reviewed.

Interest of MIBG scintigraphy in screening for pheochromocytoma in patients with medullary thyroid carcinoma

International Nuclear Information System (INIS)

Bonnin, F.; Lumbroso, J.; Schlumberger, M.; Megnigbeto, A.; Tenenbaum, F.; Leclere, J.; Travagli, J.P.; Gardet, P.; Parmentier, C.

1995-01-01

Adrenal medullary disease (AMD) is clinically silent in most patients with medullary thyroid carcinoma (MTC). During 16 years, a series of 174 MTC patients was screened yearly for AMD. Metaiodobenzylguanidine (MIBG) scans were performed in 54 cases (21 at diagnosis and 33 during the follow up of MTC) either systematically (43 cases) or in patients with biological or ultrasonographic signs of AMD (11 cases). AMD was discovered in ten patients: five patients were already known to have a type II multiple endocrine neoplasia (MEN-2); in five patients previously considered as having either a sporadic (four cases) or a familial type of isolated MTC (one case), the occurrence of AMD led to diagnose a MEN-2 a syndrome. In three cases, AMD was bilateral. MIBG scan were performed in nine of the ten patients with AMD. No false positive MIBG scan was observed in the series. All patients with positive MIBG scan had either elevated excretion of catecholamines and derivates. MIBG scan had a sensitivity of 0.9 and specificity of 1. MIBG should not be used as a screening test. In particular, MIBG scan should not be performed systematically neither at diagnosis nor during follow-up. But, in cases with suspicion of AMD, it provides important complementary functional information. (authors). 15 refs., 3 tabs., 2 figs

Quaternary ammonium-functionalized silica sorbents for the solid-phase extraction of aromatic amines under normal phase conditions.

Science.gov (United States)

Vidal, Lorena; Robin, Orlane; Parshintsev, Jevgeni; Mikkola, Jyri-Pekka; Riekkola, Marja-Liisa

2013-04-12

Quaternary ammonium-functionalized silica materials were synthesized and applied for solid-phase extraction (SPE) of aromatic amines, which are classified as priority pollutants by US Environmental Protection Agency. Hexamethylenetetramine used for silica surface modification for the first time was employed as SPE sorbent under normal phase conditions. Hexaminium-functionalized silica demonstrated excellent extraction efficiencies for o-toluidine, 4-ethylaniline and quinoline (recoveries 101-107%), while for N,N-dimethylaniline and N-isopropylaniline recoveries were from low to moderate (14-46%). In addition, the suitability of 1-alkyl-3-(propyl-3-sulfonate) imidazolium-functionalized silica as SPE sorbent was tested under normal phase conditions. The recoveries achieved for the five aromatic amines ranged from 89 to 99%. The stability of the sorbent was evaluated during and after 150 extractions. Coefficients of variation between 4.5 and 10.2% proved a high stability of the synthesized sorbent. Elution was carried out using acetonitrile in the case of hexaminium-functionalized silica and water for 1-alkyl-3-(propyl-3-sulfonate) imidazolium-functionalized silica sorbent. After the extraction the analytes were separated and detected by liquid chromatography ultraviolet detection (LC-UV). The retention mechanism of the materials was primarily based on polar hydrogen bonding and π-π interactions. Comparison made with activated silica proved the quaternary ammonium-functionalized materials to offer different selectivity and better extraction efficiencies for aromatic amines. Finally, 1-alkyl-3-(propyl-3-sulfonate) imidazolium-functionalized silica sorbent was successfully tested for the extraction of wastewater and soil samples. Copyright © 2013 Elsevier B.V. All rights reserved.

Experimental study on the usefulness of magnetotherapy in bone fractures (tibial osteotomy in the rat). Accumulation of 99 mTc MDP - tests of tensile strength - determination of alkaline phosphatase

International Nuclear Information System (INIS)

Sailer, R.

1985-01-01

Non-directional magnetic field therapy using a flux density of 60 G and a frequency of 25 Hz was carried out over 12 hours daily in rats in order to ascertain its influence on the healing process following osteotomy of the tibia with internal splint fixation of the fractured bone being carried out as an additional measure. The results thus achieved were compared to those seen in control animals, were no magnetotherapy was carried out, on the basis of scintiscan studies using 99 mTc MDP (degree of density in the callus formed around the fracture zone), the plasma levels of alkaline phosphatase and tests of tensile strength. The follow-up observations of the healing process were additionally based on radiological and histological evaluations of the animals. Beneficial effects of magnetotherapy on the healing process could not be confirmed with any statistical significance. (TRV) [de

Medullary thyroid cancer: RET testing of an archival material

DEFF Research Database (Denmark)

Godballe, Christian; Jørgensen, Gita; Gerdes, Anne-Marie Axø

2010-01-01

Medullary thyroid carcinoma (MTC) might be sporadic (75%) or hereditary (25%). Until the mid nineties the diagnosis of hereditary MTC was based on family history, clinical evaluation, histological detection of C-cell hyperplasia and tumor multifocality. Patients and families with hereditary MTC...

Medullary thyroid cancer: RET testing of an archival material

DEFF Research Database (Denmark)

Godballe, Christian; Jørgensen, Gita; Gerdes, Anne-Marie

2009-01-01

Medullary thyroid carcinoma (MTC) might be sporadic (75%) or hereditary (25%). Until the mid nineties the diagnosis of hereditary MTC was based on family history, clinical evaluation, histological detection of C-cell hyperplasia and tumor multifocality. Patients and families with hereditary MTC...

Selective arterial chemoembolization for hepatic metastases from medullary thyroid carcinoma.

Science.gov (United States)

Lorenz, Kerstin; Brauckhoff, Michael; Behrmann, Curd; Sekulla, Carsten; Ukkat, Jörg; Brauckhoff, Katrin; Gimm, Oliver; Dralle, Henning

2005-12-01

Hepatic metastases from medullary thyroid carcinoma (MTC) may impair quality of life by hypercalcitonemia-associated diarrhea and pain. In this prospective study, the effect of selective arterial chemoembolization (SACE) was evaluated. Eleven patients with hepatic metastases from MTC received 1 to 9 courses of SACE using epirubicine. Symptomatic, biochemical, and morphologic responses on SACE were recorded. Symptomatic response was observed in all symptomatic patients. However, biochemical and radiologic response occurred only in 6 patients. Liver function was not affected by SACE. One patient with unexpected concurrent pheochromocytoma metastases died after the first course. Development of side effects in the course was observed in 8 patients but were only World Health Organization grade 1. Patients' satisfaction with SACE was excellent. Long-term follow-up found 7 patients alive (1-72 months). Three patients died with tumor 6, 12, and 24 months after SACE, respectively. SACE provided good symptom palliation for the majority of patients with hepatic metastases from MTC. However, transient remission or stabilization of hepatic metastases resulted in only 60%. Further studies using a randomized protocol are required.

The impact of major trauma network triage systems on patients with major burns.

Science.gov (United States)

Nizamoglu, Metin; O'Connor, Edmund Fitzgerald; Bache, Sarah; Theodorakopoulou, Evgenia; Sen, Sankhya; Sherren, Peter; Barnes, David; Dziewulski, Peter

2016-12-01

Trauma is a leading cause of death and disability worldwide. Patients presenting with severe trauma and burns benefit from specifically trained multidisciplinary teams. Regional trauma systems have shown improved outcomes for trauma patients. The aim of this study is to determine whether the development of major trauma systems have improved the management of patients with major burns. A retrospective study was performed over a four-year period reviewing all major burns in adults and children received at a regional burns centre in the UK before and after the implementation of the regional trauma systems and major trauma centres (MTC). Comparisons were drawn between three areas: (1) Patients presenting before the introduction of MTC and after the introduction of MTC. (2) Patients referred from MTC and non-MTC within the region, following the introduction of MTC. (3) Patients referred using the urban trauma protocol and the rural trauma protocol. Following the introduction of regional trauma systems and major trauma centres (MTC), isolated burn patients seen at our regional burns centre did not show any significant improvement in transfer times, admission resuscitation parameters, organ dysfunction or survival when referred from a MTC compared to a non-MTC emergency department. There was also no significant difference in survival when comparing referrals from all hospitals pre and post establishment of the major trauma network. No significant outcome benefit was demonstrated for burns patients referred via MTCs compared to non-MTCs. We suggest further research is needed to ascertain whether burns patients benefit from prolonged transfer times to a MTC compared to those seen at their local hospitals prior to transfer to a regional burns unit for further specialist care. Copyright © 2016 Elsevier Ltd and ISBI. All rights reserved.

On the Comparison of Cognitive Function in Substance Abusers and Addicts under Methadone Treatment with Normal Individuals

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reza mohammadzadeghan

2015-09-01

Full Text Available Objective: This study was an attempt to compare cognitive functioning in substance abusers and addicts under methadone treatment with normal individuals. Method: The current study was a causal-comparative one. The statistical population of this research consisted of all male substance abusers who had referred to addiction treatment centers of Khoy city in 2013. The total of 40 addicts under methadone treatment, 40 active drug users, and 40 non-addicts were selected as the participants of this study via convenience sampling method. Wisconsin Card Sorting Test and Wechsler Memory Scale were administered to the three groups for data collection purposes. Results: The results showed that the substance abusers’ scores in Wisconsin card sorting test and Wechsler memory scale were significantly different from those of addicts under methadone treatment and normal individuals. In the same way, there was a significant difference between addicts under methadone treatment and normal individuals in terms of cognitive function however, there was no significant difference between these two groups in terms of perseveration error. Conclusion: It can be concluded that chronic use of psychoactive substances causes damage to multiple brain regions such as prefrontal cortex and hippocampus and, thereby, it leads to cognitive malfunctioning in these areas.

Biokinetic behavior of Tc in the red abalone, Haliotis rufescens: a reassessment

International Nuclear Information System (INIS)

Beasley, T.M.; Lorz, H.V.; Gonor, J.J.

1981-01-01

The biokinetic behavior of /sup 95m/Tc in the red abalone, Haliotis rufescens, is reviewed in light of recent experiments on other molluscs. Additional experimentation has confirmed that, when uptake is directly from labeled seawater, abalone exhibit concentration factors in excess of 100. Bivalve molluscs under the same experimental conditions have concentration factors that do not exceed 2. However, uptake and loss kinetics cannot be described by a single compartment model as had been previously advanced. Assimilation of /sup 95m/Tc by the abalone following a single feeding of labeled macroalga, Nereocystis pyrifera, is high (approx. 45%) and loss kinetics are similar to those observed following direct uptake from seawater

Biokinetic behavior of technetium in the red abalone, Haliotis rufescens: a re-assessment

Energy Technology Data Exchange (ETDEWEB)

Beasley, T.M.; Lorz, H.V.; Gonor, J.J. (Oregon State Univ., Newport (USA). Marine Science Center)

1982-10-01

The biokinetic behavior of sup(95m)Tc in the red abalone, haliotis rufescens, is reviewed in light of recent experiments with other molluscs. Additional experimentation has confirmed that, when uptake is directly from labeled seawater, abalones exhibit concentration factors in excess of 100. Bivalve molluscs under the same experimental conditions have concentration factors that do not exceed 2. However, uptake and loss kinetics in the abalone cannot be described by a single compartment model as had been previously advanced. Assimilation of sup(95m)Tc by abalones following a single feeding of labeled macroalga, Nereocystis luetkeana, approximately equal to 45% and loss kinetics are similar to those observed following direct uptake from seawater.

Biokinetic behavior of technetium in the red abalone, Haliotis rufescens: a re-assessment

Energy Technology Data Exchange (ETDEWEB)

Beasley, T.M.; Lorz, H.V.; Gonor, J.J.

1982-10-01

The biokinetic behavior of /sup 95m/Tc in the red abalone, Haliotis rufescens, is reviewed in light of recent experiments with other molluscs. Additional experimentation has confirmed that, when uptake is directly from labelled seawater, abalones exhibit concentration factors in excess of 100. Bivalve molluscs under the same experimental conditions have concentration factors that do not exceed 2. However, uptake and loss kinetics in the abalone cannot be described by a single compartment model as had been previously advanced. Assimilation of /sup 95m/Tc by abalones following a single feeding of labeled macroalga, Nereocystis luetkeana, is approximately 45% and loss kinetics are similar to those observed following direct uptake from seawater.

Biokinetic behavior of technetium in the red abalone, Haliotis rufescens: a re-assessment

International Nuclear Information System (INIS)

Beasley, T.M.; Lorz, H.V.; Gonor, J.J.

1982-01-01

The biokinetic behavior of sup(95m)Tc in the red abalone, haliotis rufescens, is reviewed in light of recent experiments with other molluscs. Additional experimentation has confirmed that, when uptake is directly from labeled seawater, abalones exhibit concentration factors in excess of 100. Bivalve molluscs under the same experimental conditions have concentration factors that do not exceed 2. However, uptake and loss kinetics in the abalone cannot be described by a single compartment model as had been previously advanced. Assimilation of sup(95m)Tc by abalones following a single feeding of labeled macroalga, Nereocystis luetkeana, approximately equal to 45% and loss kinetics are similar to those observed following direct uptake from seawater. (author)

75 FR 43791 - Delegation of Certain Functions Under Section 3134 of the National Defense Authorization Act for...

Science.gov (United States)

2010-07-26

... the Constitution and the laws of the United States, including section 301 of title 3, United States... of Certain Functions Under Section 1264 of the Victims of Iranian Censorship Act (Public Law 111- 84...

Design and simulation of the operation of a rotary valve for a portable prototype of a {sup 99m}Tc generator; Diseno y simulacion de funcionamiento de una valvula giratoria para un prototipo portatil generador de Tc-99m

Energy Technology Data Exchange (ETDEWEB)

Gago, Javier; Baltuano, Oscar; Hernandez, Yuri; Montoya, Eduardo [Direccion de Investigacion y Desarrollo, Instituto Peruano de Energia Nuclear, Av. Jose Saco km 12.5, Carabayllo, Lima (Peru); Lopez, Yon [Universidad Nacional de Ingenieria, Lima (Peru). Facultad de Ingenieria Mecanica y Mecanica Electrica; Direccion de Investigacion y Desarrollo, Instituto Peruano de Energia Nuclear, Av. Jose Saco km 12.5, Carabayllo, Lima (Peru)

2013-07-01

The design of a specific purpose rotary valve for a {sup 99m}Tc generator by extraction, which is being developed at IPEN, in order to contribute to the decentralization of nuclear medicine with social inclusion, is described and discussed in this paper. The prototype is reliable, low cost, and consists of a set of three three-way rotating valves with two positions, in a single device of Teflon®, which is driven by a servomotor. Structural analysis is reported considering external loads applied to the prototype, plus simulation and testing operation using a 12 volts servomotor of 16 RPM provided of a CNY70 infrared sensor, for control purposes. (authors).

Role of radiopharmaceutical renal function studies in the medical surveillance of patients with transplanted kidneys

International Nuclear Information System (INIS)

Ernst, S.

1983-01-01

In a study group of 35 patients having received a total of 37 kidneys 204 renal function scintiscans were obtained following administration of 99mTc DTPA and analysed with regard to the question as to whether radiopharmaceutical investigations using a gamma camera are a useful auxiliary tool to detect and diagnose functional disorders in the transplant that occur soon after surgery. In all of 13 patients showing complications in the form of prolonged anuria or oliguria during a period of up to 14 days following surgical intervention, the renal function scintiscans either permitted as firm diagnosis to be established or revealed conclusive findings that pointed to the necessity of further specific tests. Long-term follow-up studies carried out in 33 individuals failed or were slow to reveal acute or chronic rejection processes in one quarter of the patients, whereas the renal function scintiscans gave the earliest warning of functional disorders, unfavourable developments and complications in another quarter of patients; in the remaining part, the test results were in keeping with the clinical findings. Renal function scintiscans were thus judged to be a valuable diagnostic tool to ascertain and identify disorders occurring soon after surgery as well as to detect the early signs of functional disorders in the transplant during long-term follow-up studies. In view of the fact, however, that the sensitivity of the method in this field of application only is of the order of 75%, further research work appears to be required here. (TRV) [de

[Range of Hip Joint Motion and Weight of Lower Limb Function under 3D Dynamic Marker].

Science.gov (United States)

Xia, Q; Zhang, M; Gao, D; Xia, W T

2017-12-01

To explore the range of reasonable weight coefficient of hip joint in lower limb function. When the hip joints of healthy volunteers under normal conditions or fixed at three different positions including functional, flexed and extension positions, the movements of lower limbs were recorded by LUKOtronic motion capture and analysis system. The degree of lower limb function loss was calculated using Fugl-Meyer lower limb function assessment form when the hip joints were fixed at the aforementioned positions. One-way analysis of variance and Tamhane's T2 method were used to proceed statistics analysis and calculate the range of reasonable weight coefficient of hip joint. There were significant differences between the degree of lower limb function loss when the hip joints fixed at flexed and extension positions and at functional position. While the differences between the degree of lower limb function loss when the hip joints fixed at flexed position and extension position had no statistical significance. In 95% confidence interval, the reasonable weight coefficient of hip joint in lower limb function was between 61.05% and 73.34%. Expect confirming the reasonable weight coefficient, the effects of functional and non-functional positions on the degree of lower limb function loss should also be considered for the assessment of hip joint function loss. Copyright© by the Editorial Department of Journal of Forensic Medicine

Development of (99m)Tc-Labeled Pyridyl Benzofuran Derivatives To Detect Pancreatic Amylin in Islet Amyloid Model Mice.

Science.gov (United States)

Yoshimura, Masashi; Ono, Masahiro; Watanabe, Hiroyuki; Kimura, Hiroyuki; Saji, Hideo

2016-06-15

While islet amyloid deposition comprising amylin is one of pathological hallmarks of type 2 diabetes mellitus (T2DM), no useful amylin-imaging probe has been reported. In this study, we evaluated two (99m)Tc-labeled pyridyl benzofuran derivatives as novel amylin-imaging probes using the newly established islet amyloid model mouse. Binding experiments in vitro demonstrated that [(99m)Tc]1 displayed a higher affinity for amylin aggregates than [(99m)Tc]2. Autoradiographic studies using human pancreas sections with T2DM revealed that [(99m)Tc]1 clearly labeled islet amyloid in T2DM pancreatic sections, while [(99m)Tc]2 did not. Although the initial uptake of [(99m)Tc]1 by the normal mouse pancreas was low (0.74%ID/g at 2 min post-injection), [(99m)Tc]1 showed higher retention in the model mouse pancreas than that of the normal mouse, and exhibited strong binding to amylin aggregates in the living pancreas of the model mice. These results suggest that [(99m)Tc]1 is a potential imaging probe targeting islet amyloids in the T2DM pancreas.

Pole-placement Predictive Functional Control for under-damped systems with real numbers algebra.

Science.gov (United States)

Zabet, K; Rossiter, J A; Haber, R; Abdullah, M

2017-11-01

This paper presents the new algorithm of PP-PFC (Pole-placement Predictive Functional Control) for stable, linear under-damped higher-order processes. It is shown that while conventional PFC aims to get first-order exponential behavior, this is not always straightforward with significant under-damped modes and hence a pole-placement PFC algorithm is proposed which can be tuned more precisely to achieve the desired dynamics, but exploits complex number algebra and linear combinations in order to deliver guarantees of stability and performance. Nevertheless, practical implementation is easier by avoiding complex number algebra and hence a modified formulation of the PP-PFC algorithm is also presented which utilises just real numbers while retaining the key attributes of simple algebra, coding and tuning. The potential advantages are demonstrated with numerical examples and real-time control of a laboratory plant. Copyright © 2017 ISA. All rights reserved.

Progranulin facilitates conversion and function of regulatory T cells under inflammatory conditions.

Directory of Open Access Journals (Sweden)

Fanhua Wei

Full Text Available The progranulin (PGRN is known to protect regulatory T cells (Tregs from a negative regulation by TNF-α, and its levels are elevated in various kinds of autoimmune diseases. Whether PGRN directly regulates the conversion of CD4+CD25-T cells into Foxp3-expressing regulatory T cells (iTreg, and whether PGRN affects the immunosuppressive function of Tregs, however, remain unknown. In this study we provide evidences demonstrating that PGRN is able to stimulate the conversion of CD4+CD25-T cells into iTreg in a dose-dependent manner in vitro. In addition, PGRN showed synergistic effects with TGF-β1 on the induction of iTreg. PGRN was required for the immunosuppressive function of Tregs, since PGRN-deficient Tregs have a significant decreased ability to suppress the proliferation of effector T cells (Teff. In addition, PGRN deficiency caused a marked reduction in Tregs number in the course of inflammatory arthritis, although no significant difference was observed in the numbers of Tregs between wild type and PGRN deficient mice during development. Furthermore, PGRN deficiency led to significant upregulation of the Wnt receptor gene Fzd2. Collectively, this study reveals that PGRN directly regulates the numbers and function of Tregs under inflammatory conditions, and provides new insight into the immune regulatory mechanism of PGRN in the pathogenesis of inflammatory and immune-related diseases.

Stable and solid pellets of functionalized multi-walled carbon nanotubes produced under high pressure and temperature

Energy Technology Data Exchange (ETDEWEB)

Santos, Pâmela Andréa Mantey dos [Universidade Federal do Rio Grande do Sul, UFRGS, Programa de Pós-Graduação em Ciência dos Materiais (Brazil); Gallas, Marcia Russman [Universidade Federal do Rio Grande do Sul, UFRGS, Instituto de Física (Brazil); Radtke, Cláudio; Benvenutti, Edilson Valmir [Universidade Federal do Rio Grande do Sul, UFRGS, Instituto de Química (Brazil); Elias, Ana Laura [The Pennsylvania State University, Department of Physics and Center for 2-D and Layered Materials (United States); Rajukumar, Lakshmy Pulickal [The Pennsylvania State University, Department of Materials Science and Engineering (United States); Terrones, Humberto [Rensselaer Polytechnic Institute, Department of Physics, Applied Physics and Astronomy (United States); Endo, Morinobu [Shinshu University, Carbon Institute of Science and Technology (Japan); Terrones, Mauricio [The Pennsylvania State University, Department of Physics and Center for 2-D and Layered Materials (United States); Costa, Tania Maria Haas, E-mail: taniaha@iq.ufrgs.br, E-mail: taniahac@gmail.com [Universidade Federal do Rio Grande do Sul, UFRGS, Programa de Pós-Graduação em Ciência dos Materiais (Brazil)

2015-06-15

High pressure/temperature was applied on samples of pristine multi-walled carbon nanotubes (MWCNT), functionalized nanotubes (f-MWCNT), and nanotubes doped with nitrogen (CN{sub x}MWNT). Cylindrical compact pellets of f-MWCNT with diameters of about 6 mm were obtained under pressure of 4.0 GPa at room temperature and at 400 °C, using graphite as pressure transmitting medium. The best pellet samples were produced using nitric and sulfuric acids for the functionalization of MWCNT. The effect of high pressure/temperature on CNT was investigated by several spectroscopy and characterization techniques, such as Raman spectroscopy, X-ray powder diffraction, X-ray photoelectron spectroscopy, N{sub 2} adsorption/desorption isotherms, and transmission electron microscopy. It was found that MWCNT maintain their main features in the compacted pellets, such as integrity, original morphology, and structure, demonstrating that high-pressure/temperature compaction can indeed be used to fabricate novel CNT self-supported materials. Additionally, the specific surface area and porosity are unchanged, which is important when using bulk CNT in adsorption processes. Raman analysis of the G’-band showed a shift to lower wavenumbers when f-MWCNT were processed under high pressure, suggesting that CNT are under tensile stress.

Dysfunction in endoplasmic reticulum-mitochondria crosstalk underlies SIGMAR1 loss of function mediated motor neuron degeneration.

Science.gov (United States)

Bernard-Marissal, Nathalie; Médard, Jean-Jacques; Azzedine, Hamid; Chrast, Roman

2015-04-01

Mutations in Sigma 1 receptor (SIGMAR1) have been previously identified in patients with amyotrophic lateral sclerosis and disruption of Sigmar1 in mouse leads to locomotor deficits. However, cellular mechanisms underlying motor phenotypes in human and mouse with disturbed SIGMAR1 function have not been described so far. Here we used a combination of in vivo and in vitro approaches to investigate the role of SIGMAR1 in motor neuron biology. Characterization of Sigmar1(-/-) mice revealed that affected animals display locomotor deficits associated with muscle weakness, axonal degeneration and motor neuron loss. Using primary motor neuron cultures, we observed that pharmacological or genetic inactivation of SIGMAR1 led to motor neuron axonal degeneration followed by cell death. Disruption of SIGMAR1 function in motor neurons disturbed endoplasmic reticulum-mitochondria contacts, affected intracellular calcium signalling and was accompanied by activation of endoplasmic reticulum stress and defects in mitochondrial dynamics and transport. These defects were not observed in cultured sensory neurons, highlighting the exacerbated sensitivity of motor neurons to SIGMAR1 function. Interestingly, the inhibition of mitochondrial fission was sufficient to induce mitochondria axonal transport defects as well as axonal degeneration similar to the changes observed after SIGMAR1 inactivation or loss. Intracellular calcium scavenging and endoplasmic reticulum stress inhibition were able to restore mitochondrial function and consequently prevent motor neuron degeneration. These results uncover the cellular mechanisms underlying motor neuron degeneration mediated by loss of SIGMAR1 function and provide therapeutically relevant insight into motor neuronal diseases. © The Author (2015). Published by Oxford University Press on behalf of the Guarantors of Brain. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

Calendar Year 2007 Program Benefits for ENERGY STAR Labeled Products

Energy Technology Data Exchange (ETDEWEB)

Sanchez, Marla Christine; Homan, Gregory; Brown, Richard

2008-10-31

ENERGY STAR is a voluntary energy efficiency-labeling program operated jointly by the United States Department of Energy and the United States Environmental Protection Agency (US EPA). Since the program inception in 1992, ENERGY STAR has become a leading international brand for energy efficient products. ENERGY STAR's central role in the development of regional, national, and international energy programs necessitates an open process whereby its program achievements to date as well as projected future savings are shared with committed stakeholders. Through 2007, the program saved 7.1 Quads of primary energy and avoided 128 MtC equivalent. The forecast shows that the program is expected to save 21.2 Quads of primary energy and avoid 375 MtC equivalent over the period 2008-2015. The sensitivity analysis bounds the best estimate of carbon avoided between 84 MtC and 172 MtC (1993 to 2007) and between 243 MtC and 519 MtC (2008 to 2015).

Planning Water Resources in an Agroforest Ecosystem for Improvement of Regional Ecological Function Under Uncertainties

Directory of Open Access Journals (Sweden)

Xueting Zeng

2018-04-01

Full Text Available In this study, an agroforestry ecosystem project (AEP is developed for confronting the conflict between agricultural development and forest protection. A fuzzy stochastic programming with Laplace scenario analysis (FSL is proposed for planning water resources in an AEP issue under uncertainties. FSL can not only deal with spatial and temporal variations of hydrologic elements and meteorological conditions; but also handle uncertainties that are expressed in terms of probability, possibility distributions and fuzzy sets; meanwhile, policy scenario analysis with Laplace’s criterion (PSL is introduced to handle probability of each scenario occurrence under the supposition of no data available. The developed FSL can be applied to an AEP issue in Xixian county, located in north of China. The result of ecological effects, water allocation patterns, pollution mitigation schemes and system benefits under various scenarios are obtained, which can support policymakers adjusting current strategy to improve regional ecological function with cost-effective and sustainable manners. Meanwhile, it can support generating a robust water plan for regional sustainability in an AEP issue under uncertainties.

Brain Tumour Scintigraphy with {sup 99m}Tc-Pertechnetate, {sup 99m}Tc-Fe(II) Complex and {sup 131}I-Labelled Macroaggregated Albumin - Comparison of Results; La Scintigraphie des Tumeurs Cerebrales a l'Aide de Pertechnetate Marque au {sup 99m}Tc, de Complexe {sup 99m}Tc-Fe-II et de Macroagregats d'Albumine Marques au {sup 131}I. Comparaison des Resultats

Energy Technology Data Exchange (ETDEWEB)

Haas, J. P.; Dietz, H.; Schmidt, K. J.; Doerr, F.; Brod, K. H.; Wolf, R. [Institut de Radiologie Clinique et Clinique de Neurochirurgie, Universite de Mayence, Federal Republic of Germany (Germany)

1969-05-15

{sup 99m}Tc, in the form of pertechnetate, has now gained its place in brain scintigraphy. The present authors and many others have found its diagnostic value equal to that of substances labelled with mercury or iodine. Using {sup 99m}Tc-pertechnetate as the basis of their work, the authors attempted to extend isotopic diagnosis by two methods, namely: intra-arterial introduction of macroaggregated albumin; and intravenous injection of a new substance, the {sup 99m}Tc-Fe(II) complex. Following their publication in 1966 of the results obtained with the first method, the authors now present an account of their experiments carried out on over 100 patients with brain tumours. Compared with scintigraphy involving intravenous injection of {sup 99m}Tc-pertechnetate, this new method gives supplementary information which is often of considerable help in clinical neuroradiological diagnosis of these patients. The findings in a majority of cases were confirmed by operation or by autopsy. The method made it possible for the first time to use scintigraphy to visualize the arterial network of the brain. In view of the ease with which brain scintigraphy can be performed after intravenous injection, and also of our experience with the {sup 99m}Tc-Fe(II) complex in kidney scintigraphy and the evidence of a brief report in the United States literature, the authors decided to try out this substance in the detection of brain tumours. Their first results showed it to be incontestably superior to all others previously applied intravenously. It has the indubitable advantages of {sup 99m}Tc as regards the irradiation dose to the patient and gives an exceptionally precise delineation of the invasive cerebral processes due to a rapid fall in blood concentration. A combination of these two new scintigraphic methods would thus seem to open up new possibilities and greatly enhance the field of application of radioisotopes in the clinical study of brain diseases. The paper contains material

3 CFR - Delegation of Certain Functions Under Sections 603-604 and 699 of the Foreign Relations...

Science.gov (United States)

2010-01-01

...-604 and 699 of the Foreign Relations Authorization Act, Fiscal Year 2003 (Public Law 107-228... Functions Under Sections 603-604 and 699 of the Foreign Relations Authorization Act, Fiscal Year 2003...-604 and 699 of the Foreign Relations Authorization Act, Fiscal Year 2003 (Public Law 107-228). You are...

Study on ceramic breeder and related materials by means of work function measurement under irradiation

International Nuclear Information System (INIS)

Luo, G.N.; Terai, T.; Yamawaki, M.; Yamaguchi, K.

2002-01-01

Ceramic breeder materials, Li 2 O, LiAlO 2 and Li 4 SiO 4 , under irradiation have been studied using a Kelvin probe that measures work function changes of materials. Surface charging was observed to influence greatly the probe output, which can be explained qualitatively employing a model concerning induction electric field due to external field and free charges on ceramic surface. It is found that the insulating ceramics could not be studied properly with the Kelvin probe. A probable solution is to heat the ceramics, so as to raise their electric conductivities high enough to root out the surface charging. Also briefly discussed is the application of the probe to metals under ion irradiation. (orig.)

An experimental study on recovery of renal function using 99mTc DMSA scintigram after percutaneous nephrostomy in unilateral hydronephrosis

International Nuclear Information System (INIS)

Moon, Tae Yong; Nam, Sang Hwa; Park, Jong Yeon; Kim, Byung Soo

1992-01-01

Obstruction on the urinary tract eventually results in damage to the kidneys and lose of function. The questions that concern the clinician are the degree of nephron loss in that kidney and potential for recovery following the relief of obstruction. 99m Tc DMSA accumulates in tubule cells and has been proposed as a marker of the tubular mass. The authors estimated the renal uptake ratio of 99m Tc DMSA for the degree of nephron loss corresponding to duration of hydronephrosis following left ureteral ligation in 5 New Zealand white rabbits and the potential for recovery following percutaneous nephrostomy of hydronephrosis in 24 rabbits. While the renal uptake ratio of 99m Tc DMSA of the kidney with unilateral hydronephrosis following ureteral ligation reduced dramatically within 24 hour, that of the opposite healthy kidney increased, and the total renal uptake ratio was same as normal functioning kidneys before ureteral ligation. Upon ureteral release, there was no evidence of definite recovery or impairment in the experimental kidneys for 5 days. The authors conclude that a combination of ureteral release and administration of some drugs such as renal vasodilator or diuretics is an appropriate treatment for the recovery of function in unilateral hydronephrosis

Functional richness: Overview of indices and underlying concepts

Science.gov (United States)

Legras, G.; Loiseau, N.; Gaertner, J.-C.

2018-02-01

Functional richness, currently defined as the amount of niche space occupied by the species within a community, is one of the three major components of functional diversity. Different indices have been developed in order to quantify this component. However, the range of indices available for assessing functional richness, often mathematically complex and based on different rationales, can cause confusion for field ecologists and lead to misinterpretation of the results obtained. In this context, we have provided the first study exclusively focused on the comparison of the definitions, advantages and drawbacks of a large set of functional richness indices. The first part of this work is focused on four indices (FDP&G, FRic, TOP and N-hypervolumes indices) that are currently the most commonly used for assessing functional richness. We have completed our study by including recently developed indices that enable us to take into account the intraspecific trait variability (i.e. FRim index and TDP framework), because there is currently a growing scientific consensus regarding the necessity of including this aspect in the assessment of the functional diversity of communities. We demonstrate that although authors have argued that their index describes the functional richness, each of them describes only part of it, and this part may strongly differ from one index to another. Rather than advocating the general use of a single index and/or systematically avoiding others, our study highlights the need for selecting indices in close relation with the context, the available data and the aims of each study. Such a strategy is an essential preliminary step for preventing misunderstanding and artefactual controversies. Along these lines, we propose some guidelines to help users in selecting the most appropriate indices according both to the facet of functional richness on which they wish to focus and to the characteristics of the available data.

Differences in functional traits between invasive and native Amaranthus species under simulated acid deposition with a gradient of pH levels

Science.gov (United States)

Wang, Congyan; Wu, Bingde; Jiang, Kun; Zhou, Jiawei

2018-05-01

Co-occurring invasive plant species (invaders hereafter) and natives receive similar or even the same environmental selection pressures. Thus, the differences in functional traits between natives and invaders have become widely recognized as a major driving force of the success of plant invasion. Meanwhile, increasing amounts of acid are deposited into ecosystems. Thus, it is important to elucidate the potential effects of acid deposition on the functional traits of invaders in order to better understand the potential mechanisms for the successful invasion. This study aims to address the differences in functional traits between native red amaranth (Amaranthus tricolor L.; amaranth hereafter) and invasive redroot pigweed (A. retroflexus L.; pigweed hereafter) under simulated acid deposition with a gradient of pH levels. Pigweed was significantly taller than amaranth under most treatments. The greater height of pigweed can lead to greater competitive ability for resource acquisition, particularly for sunlight. Leaf shape index of pigweed was also significantly greater than that of amaranth under all treatments. The greater leaf shape index of pigweed can enhance the efficiency of resource capture (especially sunlight capture) via adjustments to leaf shape and size. Thus, the greater height and leaf shape index of pigweed can significantly enhance its competitive ability, especially under acid deposition. Acid deposition of pH 5.6 significantly increased amaranth leaf width in the co-cultivation due to added nutrients. The pH 4.5 acid deposition treatment significantly increased the specific leaf area of amaranth in the monoculture compared with the pH 5.6 acid deposition treatment and the control. The main mechanism explaining this pattern may be due to acid deposition mediating a hormesis effect on plants, promoting plant growth. The values of the relative competition intensity between amaranth and pigweed for most functional traits were lower than zero under most

Calculation of probability density functions for temperature and precipitation change under global warming

International Nuclear Information System (INIS)

Watterson, Ian G.

2007-01-01

Full text: he IPCC Fourth Assessment Report (Meehl ef al. 2007) presents multi-model means of the CMIP3 simulations as projections of the global climate change over the 21st century under several SRES emission scenarios. To assess the possible range of change for Australia based on the CMIP3 ensemble, we can follow Whetton etal. (2005) and use the 'pattern scaling' approach, which separates the uncertainty in the global mean warming from that in the local change per degree of warming. This study presents several ways of representing these two factors as probability density functions (PDFs). The beta distribution, a smooth, bounded, function allowing skewness, is found to provide a useful representation of the range of CMIP3 results. A weighting of models based on their skill in simulating seasonal means in the present climate over Australia is included. Dessai ef al. (2005) and others have used Monte-Carlo sampling to recombine such global warming and scaled change factors into values of net change. Here, we use a direct integration of the product across the joint probability space defined by the two PDFs. The result is a cumulative distribution function (CDF) for change, for each variable, location, and season. The median of this distribution provides a best estimate of change, while the 10th and 90th percentiles represent a likely range. The probability of exceeding a specified threshold can also be extracted from the CDF. The presentation focuses on changes in Australian temperature and precipitation at 2070 under the A1B scenario. However, the assumption of linearity behind pattern scaling allows results for different scenarios and times to be simply obtained. In the case of precipitation, which must remain non-negative, a simple modification of the calculations (based on decreases being exponential with warming) is used to avoid unrealistic results. These approaches are currently being used for the new CSIRO/ Bureau of Meteorology climate projections

Bayesian Estimation Of Shift Point In Poisson Model Under Asymmetric Loss Functions

Directory of Open Access Journals (Sweden)

uma srivastava

2012-01-01

Full Text Available The paper deals with estimating  shift point which occurs in any sequence of independent observations  of Poisson model in statistical process control. This shift point occurs in the sequence when  i.e. m  life data are observed. The Bayes estimator on shift point 'm' and before and after shift process means are derived for symmetric and asymmetric loss functions under informative and non informative priors. The sensitivity analysis of Bayes estimators are carried out by simulation and numerical comparisons with  R-programming. The results shows the effectiveness of shift in sequence of Poisson disribution .

Advances and controversies in the management of medullary thyroid carcinoma.

Science.gov (United States)

Maia, Ana Luiza; Wajner, Simone Magagnin; Vargas, Carla Vaz Ferreira

2017-01-01

Medullary thyroid carcinoma (MTC) comprises approximately 4% of all malignant thyroid neoplasms. Although the majority of patients have a good prognosis, a subgroup of patients develops progressive disease and requires systemic therapy. Here, we focused on the current MTC therapeutic approaches and discussed the advantages and disadvantages of molecular targeted therapies. Targeted molecular therapies that inhibit RET and other tyrosine kinase receptors involved in angiogenesis have been shown to improve progression-free survival in patients with advanced MTC. Two drugs, vandetanib and cabozantinib, have been approved for the treatment of progressive or symptomatic MTC, and several others have exhibited variable efficacy. No tyrosine kinase inhibitor has been shown to improve survival. Although no definitive recommendation can currently be made, cumulative data indicate that knowledge of the tumor mutational profile may facilitate improvements in targeted therapy for MTC. Tyrosine kinase inhibitors are effective therapeutic agents for the treatment of progressive MTC. Nevertheless, it is not clear who will benefit the most from therapy, and the decision regarding when and how to initiate the treatment should be made based on the patient's medical history and tumor behavior. Hopefully, in the near future, molecular profiling of MTC can be used to determine the most effective molecular therapeutic target.

Improved Capacity and Fairness of Massive Machine Type Communications in Millimetre Wave 5G Network

Directory of Open Access Journals (Sweden)

Naser Al-Falahy

2018-02-01

Full Text Available In the Fifth Generation (5G wireless standard, the Internet of Things (IoT will interconnect billions of Machine Type Communications (MTC devices. Fixed and mobile wearable devices and sensors are expected to contribute to the majority of IoT traffic. MTC device mobility has been considered with three speeds, namely zero (fixed and medium and high speeds of 30 and 100 kmph. Different values for device mobility are used to simulate the impact of device mobility on MTC traffic. This work demonstrates the gain of using distributed antennas on MTC traffic in terms of spectral efficiency and fairness among MTC devices, which affects the number of devices that can be successfully connected. The mutual use of Distributed Base Stations (DBS with Remote Radio Units (RRU and the adoption of the millimetre wave band, particularly in the 26 GHz range, have been considered the key enabling technologies for addressing MTC traffic growth. An algorithm has been set to schedule this type of traffic and to show whether MTC devices completed their traffic upload or failed to reach the margin. The gains of the new architecture have been demonstrated in terms of spectral efficiency, data throughput and the fairness index.

Lung function declines in patients with pulmonary sarcoidosis and increased respiratory epithelial permeability to 99mTc-DTPA

International Nuclear Information System (INIS)

Chinet, T.; Dusser, D.; Labrune, S.; Collignon, M.A.; Chretien, J.; Huchon, G.J.

1990-01-01

Respiratory epithelial clearance of 99m Tc-DTPA (RC-Tc-DTPA) and pulmonary function tests (PFT) were determined at intervals of 6 or 12 months in 37 untreated, nonsmoking patients with sarcoidosis over a period of 6 to 36 months. PFT included the measurements of total lung capacity (TLC), vital capacity (VC), FEV1, and diffusing capacity for carbon monoxide. No difference was found between the respiratory clearance of 113m In-DTPA (2.25 +/- 1.00%/min) and RC-Tc-DTPA (2.29 +/- 1.11%/min) in eight patients with pulmonary sarcoidosis. Pulmonary function decreased 15% or more in at least 2 function tests during 11 follow-up periods, but it remained stable during 47 follow-up periods. In patients whose lung function deteriorated, RC-Tc-DTPA increased to 3.51 +/- 1.55%/min; in contrast, in patients whose lung function remained stable, regardless of the initial values, RC-Tc-DTPA was normal (1.00 +/- 0.50%/min; p less than 0.001). In eight patients who were treated with corticosteroids, RC-Tc-DTPA decreased from 3.48 +/- 1.31%/min to 1.56 +/- 0.64%/min (p less than 0.001), and PFT improved. We conclude that in nonsmokers with pulmonary sarcoidosis, increased RC-Tc-DTPA is not related to dissociation of 99mTc from DTPA, RC-Tc-DTPA is increased when pulmonary function decreases, and, when increased, RC-Tc-DTPA decreases with corticosteroid therapy

Evaluation of functioning of ICDS project areas under Indore and Ujjain divisions of the state of Madhya Pradesh

Directory of Open Access Journals (Sweden)

Sanjay Dixit

2010-07-01

Full Text Available Background: Integrated Child Development Services (ICDS is recognized worldwide as one of the most efficient community based programmes promoting early childhood care. Regular evaluations of the programme have been conducted to make it more effective and adequate for the beneficiaries. Objectives: To evaluate the functioning of the Anganwadi Centers under different project areas of Indore and Ujjain Divisions. Methods: Under the present evaluation system one ICDS project and five Anganwadi Centers under the project area (AWCs were visited on a monthly basis and services provided reviewed. Findings reported are from nine project areas under Indore and Ujjain Divisions in the state of Madhya Pradesh from October 2008 – June 2009. Results: A total of 45 centers were evaluated. 29 centers were operating from rented buildings and storage facilities were lacking at 19 of the centers. Though the quality of food was acceptable to the beneficiaries shortage of food was a problem at the centers. Absence of Pre-School Education (PSE and Nutrition and Health Education (NHED Kits compromised PSE and NHED activities at the centers. Unavailability of medicine kits, lack of regular visits by the ANMs to the centers and absence of routine health check up of beneficiaries were other problems encountered under the project areas surveyed. Availability of a doctor under each project area was stated as a major need by the workers. Conclusion: Coordinated steps catering to different services provided at the centers are needed to optimize the functioning of the ICDS scheme.

Know the risk, take the win: how executive functions and probability processing influence advantageous decision making under risk conditions.

Science.gov (United States)

Brand, Matthias; Schiebener, Johannes; Pertl, Marie-Theres; Delazer, Margarete

2014-01-01

Recent models on decision making under risk conditions have suggested that numerical abilities are important ingredients of advantageous decision-making performance, but empirical evidence is still limited. The results of our first study show that logical reasoning and basic mental calculation capacities predict ratio processing and that ratio processing predicts decision making under risk. In the second study, logical reasoning together with executive functions predicted probability processing (numeracy and probability knowledge), and probability processing predicted decision making under risk. These findings suggest that increasing an individual's understanding of ratios and probabilities should lead to more advantageous decisions under risk conditions.

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)

78 FR 22761 - Delegation of Functions Under Sections 404 and 406 of Public Law 112-208

Science.gov (United States)

2013-04-16

...--Delegation of Functions Under Sections 404 and 406 of Public Law 112-208 Presidential Determination No. 2013... and 406 of Public Law 112-208 Memorandum for the Secretary of State [and] the Secretary of the... conferred upon the President by sections 404 and 406 of Public Law 112-208 as follows: I hereby delegate to...

Locally optimal control under unknown dynamics with learnt cost function: application to industrial robot positioning

Science.gov (United States)

Guérin, Joris; Gibaru, Olivier; Thiery, Stéphane; Nyiri, Eric

2017-01-01

Recent methods of Reinforcement Learning have enabled to solve difficult, high dimensional, robotic tasks under unknown dynamics using iterative Linear Quadratic Gaussian control theory. These algorithms are based on building a local time-varying linear model of the dynamics from data gathered through interaction with the environment. In such tasks, the cost function is often expressed directly in terms of the state and control variables so that it can be locally quadratized to run the algorithm. If the cost is expressed in terms of other variables, a model is required to compute the cost function from the variables manipulated. We propose a method to learn the cost function directly from the data, in the same way as for the dynamics. This way, the cost function can be defined in terms of any measurable quantity and thus can be chosen more appropriately for the task to be carried out. With our method, any sensor information can be used to design the cost function. We demonstrate the efficiency of this method through simulating, with the V-REP software, the learning of a Cartesian positioning task on several industrial robots with different characteristics. The robots are controlled in joint space and no model is provided a priori. Our results are compared with another model free technique, consisting in writing the cost function as a state variable.

Coregistering functional near-infrared spectroscopy with underlying cortical areas in infants

Science.gov (United States)

Lloyd-Fox, Sarah; Richards, John E.; Blasi, Anna; Murphy, Declan G. M.; Elwell, Clare E.; Johnson, Mark H.

2014-01-01

Abstract. Functional near-infrared spectroscopy (fNIRS) is becoming a popular tool in developmental neuroscience for mapping functional localized brain responses. However, as it cannot provide information about underlying anatomy, researchers have begun to conduct spatial registration of fNIRS channels to cortical anatomy in adults. The current work investigated this issue with infants by coregistering fNIRS and magnetic resonance imaging (MRI) data from 55 individuals. Our findings suggest that fNIRS channels can be reliably registered with regions in the frontal and temporal cortex of infants from 4 to 7 months of age. Although some macro-anatomical regions are difficult to consistently define, others are more stable and fNIRS channels on an age-appropriate MRI template are often consistent with individual infant MRIs. We have generated a standardized scalp surface map of fNIRS channel locators to reliably locate cortical regions for fNIRS developmental researchers. This new map can be used to identify the inferior frontal gyrus, superior temporal sulcus (STS) region [which includes the superior and middle temporal gyri (MTG) nearest to the STS], and MTG and temporal-parietal regions in 4- to 7-month-old infants. Future work will model data for the whole head, taking into account the properties of light transport in tissue, and expanding to different ages across development. PMID:25558463

Epigenetics in Medullary Thyroid Cancer: From Pathogenesis to Targeted Therapy.

Science.gov (United States)

Vitale, Giovanni; Dicitore, Alessandra; Messina, Erika; Sciammarella, Concetta; Faggiano, Antongiulio; Colao, Annamaria

2016-01-01

Medullary thyroid carcinoma (MTC) originates from the parafollicular C cells of the thyroid gland. Mutations of the RET proto-oncogene are implicated in the pathogenesis of MTC. Germline activating mutations of this gene have been reported in about 88-98% of familial MTCs, while somatic mutations of RET gene have been detected in about 23-70% of sporadic forms. Although these genetic events are well characterized, much less is known about the role of epigenetic abnormalities in MTC. The present review reports a detailed description of epigenetic abnormalities (DNA methylation, histone modifications and miRNA profile), probably involved in the pathogenesis and progression of MTC. A systematic review was performed using Pubmed and Google patents databases. We report the current understanding of epigenetic patterns in MTC and discuss the potential use of current knowledge in designing novel therapeutic strategies through epigenetic drugs, focusing on recent patents in this field. Taking into account the reversibility of epigenetic alterations and the recent development in this field, epigenetic therapy may emerge for clinical use in the near future for patients with advanced MTC.

Study by Monte Carlo simulation of the absorbed dose in cells of breast cancer of the line MDA-MB231, due to sources of {sup 111}In, {sup 177}Lu and {sup 99m}Tc internalized in the nucleus. First results; Estudio por simulacion Monte Carlo de la dosis absorbida en celulas de cancer de seno de la linea MDA-MB231, debida a fuentes de {sup 11I}n, {sup 177}Lu y {sup 99m}Tc internalizadas en el nucleo. Primeros resultados

Energy Technology Data Exchange (ETDEWEB)

Rojas C, E. L.; Perez A, M., E-mail: leticia.rojas@inin.gob.mx [ININ, Carretera Mexico-Toluca s/n, 52750 Ocoyoacac, Estado de Mexico (Mexico)

2011-11-15

The necessity to design innovative treatments and to diagnose the cancer early, has taken to investigate therapies at cellular and molecular level. The design of appropriate radio-molecules to these therapies makes necessary to characterize in way exhaustive radionuclides that they are of accessible production in our country and to study as distributing the dose at cellular level with bio-molecules glued them. In this context, was realized the present work. Using Monte Carlo simulation, the energy deposited in a geometric model of cells of breast cancer was obtained, MDA-MB231, due to different radionuclides. The energy deposited in the nucleus was evaluated, in the cytoplasm and in the membrane of the cell, using the simulation code Monte Carlo Penelope 2008. A punctual source was simulated in the center of the cell nucleus. In each case all the emissions of each radionuclide majors to 400 eV were simulated. The energies deposited by disintegration in the nucleus, cytoplasm, membrane of the cell and in a sphere of 2 cm surrounding the source (in eV) were: 4.30E3, 4.85E2, 1.07E2 and 3.29E4, correspondingly, for the {sup 111}In; 4.46E3, 3.76E3, 1.26E3 and 1.33E5 for the {sup 177}Lu and; 2.12E3, 2.58E2, 9.33E1 and 1.88E4 for the {sup 99m}Tc. We can conclude that if the union of these radionuclides happens to a compound that was internalized to the cell nucleus, the best for therapy at this level is the conjugate with the {sup 177}Lu, followed by that with {sup 111}In and in third place that with {sup 99m}Tc. (Author)

Modelling of electric characteristics of 150-watt peak solar panel using Boltzmann sigmoid function under various temperature and irradiance

Science.gov (United States)

Sapteka, A. A. N. G.; Narottama, A. A. N. M.; Winarta, A.; Amerta Yasa, K.; Priambodo, P. S.; Putra, N.

2018-01-01

Solar energy utilized with solar panel is a renewable energy that needs to be studied further. The site nearest to the equator, it is not surprising, receives the highest solar energy. In this paper, a modelling of electrical characteristics of 150-Watt peak solar panels using Boltzmann sigmoid function under various temperature and irradiance is reported. Current, voltage, temperature and irradiance data in Denpasar, a city located at just south of equator, was collected. Solar power meter is used to measure irradiance level, meanwhile digital thermometer is used to measure temperature of front and back panels. Short circuit current and open circuit voltage data was also collected at different temperature and irradiance level. Statistically, the electrical characteristics of 150-Watt peak solar panel can be modelled using Boltzmann sigmoid function with good fit. Therefore, it can be concluded that Boltzmann sigmoid function might be used to determine current and voltage characteristics of 150-Watt peak solar panel under various temperature and irradiance.

Basal Serum Calcitonin, After Calcium Stimulation, and in the Needle Washout of Patients with Thyroid Nodules and Mild or Moderate Basal Hypercalcitoninemia.

Science.gov (United States)

Rosario, P W; Calsolari, M R

2017-02-01

This prospective study evaluated the concentrations of basal serum calcitonin (Ctn), Ctn after stimulation with calcium, and Ctn in the needle washout (FNA-Ctn) as predictors of sporadic medullary thyroid carcinoma (MTC) in patients with thyroid nodules and basal Ctn between 10 and 100 pg/ml. Forty-one patients were included in the study. MTC was diagnosed in only 6 patients (14.6%). None of the patients with basal Ctn≤24.6 pg/ml (n=26) or stimulated Ctn≤186.5 pg/ml (n=21) had MTC. All patients without MTC had basal Ctnstimulated Ctnbasal Ctn between 24.6 and 47 pg/ml (n=12), 3 (25%) had MTC. Among patients with stimulated Ctn between 186.5 and 655.2 pg/ml (n=18), 4 (22.2%) had MTC. FNA-Ctn distinguished nodules that were MTC (n=6) from those that were not (n=60), without overlapping results. In the calcium stimulation test, 19 patients (46.3%) reported some adverse effect, but none of them was severe or required specific treatment. Our results highlight that in patients without a history suspicious for MTC, mild or moderate basal hypercalcitoninemia should not establish the diagnosis of this tumor. Depending on the concentration found, basal Ctn should be sufficient to define patient management. In doubtful cases, FNA-Ctn seems to be the best diagnostic test. Calcium stimulation testing was safe, but more studies are needed to determine the Ctn cutoff after stimulation with calcium. © Georg Thieme Verlag KG Stuttgart · New York.

Behavior of technetium in freshwater environments

Energy Technology Data Exchange (ETDEWEB)

Blaylock, B.G.; Frank, M.L.; Hoffman, F.O.; DeAngelis, D.L.

1984-01-01

In a previous study, /sup 95m/Tc, as a pertechnetate, was released to a small, experimental, freshwater pond, and the concentrations were determined in biotic and abiotic components of the pond ecosystem. A simple mathematical model was developed to predict the concentration of /sup 95m/Tc in fish and snails. Results from this study indicated that uptake through the food chain was an important source of technetium to the higher trophic levels (i.e., fish). In the current study, an experimental pond was spiked with /sup 95m/Tc in the pertechnetate form, and the concentrations of /sup 95m/Tc were measured in the lower trophic levels. Emphasis was placed on measuring the concentration of /sup 95m/Tc in zooplankton, benthic invertebrates, and the aquatic macrophyte Elodea canadensis. Fish were excluded from the pond to allow the development of a large zooplankton population. The concentration of /sup 95m/Tc in water decreased from 0.75 Bq/mL 1 h after the pond was spiked, to 0.21 Bq/mL at 20 d. Throughout the experiment, at least 98% of the /sup 95m/Tc in the water was in the dissolved fraction (0.4 ..mu..m). Zooplankton accumulated /sup 95m/Tc rapidly, having concentration factors (Bq/g sample wet wt. divided by Bq/g water) ranging from 3 at 4 h to 36 at 20 d. Concentration factors ranged from 3 to 8 for benthic insects and from 1 to 62 for the aquatic macrophyte.

Behavior of technetium in freshwater environments

International Nuclear Information System (INIS)

Blaylock, B.G.; Frank, M.L.; Hoffman, F.O.; DeAngelis, D.L.

1984-01-01

In a previous study, /sup 95m/Tc, as a pertechnetate, was released to a small, experimental, freshwater pond, and the concentrations were determined in biotic and abiotic components of the pond ecosystem. A simple mathematical model was developed to predict the concentration of /sup 95m/Tc in fish and snails. Results from this study indicated that uptake through the food chain was an important source of technetium to the higher trophic levels (i.e., fish). In the current study, an experimental pond was spiked with /sup 95m/Tc in the pertechnetate form, and the concentrations of /sup 95m/Tc were measured in the lower trophic levels. Emphasis was placed on measuring the concentration of /sup 95m/Tc in zooplankton, benthic invertebrates, and the aquatic macrophyte Elodea canadensis. Fish were excluded from the pond to allow the development of a large zooplankton population. The concentration of /sup 95m/Tc in water decreased from 0.75 Bq/mL 1 h after the pond was spiked, to 0.21 Bq/mL at 20 d. Throughout the experiment, at least 98% of the /sup 95m/Tc in the water was in the dissolved fraction (0.4 μm). Zooplankton accumulated /sup 95m/Tc rapidly, having concentration factors (Bq/g sample wet wt. divided by Bq/g water) ranging from 3 at 4 h to 36 at 20 d. Concentration factors ranged from 3 to 8 for benthic insects and from 1 to 62 for the aquatic macrophyte

99mTc-3PRGD2 scintigraphy to stage liver fibrosis and evaluate reversal after fibrotic stimulus withdrawn

International Nuclear Information System (INIS)

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

2017-01-01

Objective: Scintigraphy using 99mTc-3PRGD2 targeting integrin αvβ3 could assess activation of hepatic stellate cells (HSCs). Liver fibrogenesis is intimately associated with activation of HSCs, and the fibrolytic process is accompanied by the reduction of the activated HSCs. In this study, we aimed to evaluate the feasibility of this method to assess the severity of liver fibrosis and the reversal after the fibrotic stimulus withdrawal. Methods: Liver fibrosis of different stages was induced by thioacetamide (TAA) injection for 2, 4 and 6 weeks (n = 6 for each time point). Another 6 rats with 8-week TAA administration (the 8-week group) and 6 rats which were injected with TAA for 6 weeks, and then withdrawn of TAA for 2 weeks (spontaneous recovery rats, SRR) were designed. The ratios of radioactivity detected in the liver vs. the heart at 30 min post-injection of 99m Tc-3PRGD2 (L/H30 min ), the collagen proportionate area (CPA), the protein and mRNA levels of integrin α v , integrin β 3 were analyzed and compared among groups. Results: The Ishak stage scores of the livers in the control and 2, 4, 6-week groups increased when the TAA administration period was extended. L/H30 min increased with the upgrading of liver fibrosis and the differences between each pair of groups were statistically significant (p 30 min in the 8-week group was similar to that in the 6-week group (p > 0.05), but was significantly higher than that in the SRR group (p = 0.005). Conclusions: Scintigraphy using 99m Tc-3PRGD2 may provide a non-invasive method for grading liver fibrosis and assessing liver fibrosis reversal.

Radioguided sentinel node biopsy with 99mTc colloidal (Re) sulphide: Our experience

International Nuclear Information System (INIS)

Lago, G.; Alonso, O.; Aizen, B.; Juri, C.

2004-01-01

Full text: It has been demonstrated that nodal metastases from different solid tumors are not random events. Tumour spread within the regional draining basin has been shown to progress in an orderly fashion with first draining basin (sentinel node) most likely to have metastatic involvement. Thus, the sentinel node examination accurately reflects the histology of the remainder of the lymphatic basin. Sentinel node biopsy (SLB) with previous lymphatic mapping by means of radiocolloid lymphoscintraphy has been proposed by many authors as a routine method for staging the regional lymph nodes in patients with cutaneous melanoma and breast cancer. A positive SLB is found to carry high prognostic significance and identifies those patients who might benefit from early therapeutic lymph node dissection and adjuvant treatment. The aim of this retrospective study was to evaluate our experience with radioguided SLB in patients with different tumours. We studied 154 patients between 1998-2003, with clinically localized breast cancer (n=45), melanoma (n=82), cervix carcinoma (n=22) and penis carcinoma (n=5). Lymphoscintigraphy was performed 6-18 hours before surgery using a LFOV gamma camera equipped with a LEHR collimator. A dose of 111-185 MBq of 99mTc colloidal sulphide (Nanocis, Cis bio international, Gif-Sur-Yvette, France) was injected around the primary lesion (melanoma, breast cancer, and penis carcinoma) and into the four quadrants of the cervix (cervix carcinoma). All basins identified by lymphoscintigraphy were explored through incisions directed by the use of a gamma probe. Radioactivity (counts /sec) of the sentinel node(s) and the adjacent tissues was measured in-vivo and verified ex-vivo after removal. A signal to background ratio higher than 2 to 3 in-vivo and higher than 10 ex-vivo was considered significant. Blue dye mapping was performed in all cases of breast cancer but left at discretion of the surgeon for the remaining tumours. Serial sections of the

Functional integration processes underlying the instruction-based learning of novel goal-directed behaviors.

Science.gov (United States)

Ruge, Hannes; Wolfensteller, Uta

2013-03-01

How does the human brain translate symbolic instructions into overt behavior? Previous studies suggested that this process relies on a rapid control transition from the lateral prefrontal cortex (LPFC) to the anterior striatum (aSTR) and premotor cortex (PMC). The present fMRI study investigated whether the transfer from symbolic to pragmatic stimulus-response (S-R) rules relies on changes in the functional coupling among these and other areas and to which extent action goal representations might get integrated within this symbolic-pragmatic transfer. Goal integration processes were examined by manipulating the contingency between actions and differential outcomes (i.e. action goals). We observed a rapid strengthening of the functional coupling between the LPFC and the basal ganglia (aSTR and putamen) and orbitofrontal cortex (OFC) as well as between the LPFC and the anterior dorsal PMC (pre-PMd), the anterior inferior parietal lobule (aIPL), and the posterior superior parietal lobule (pSPL). Importantly, only some of these functional integration processes were sensitive to the outcome contingency manipulation, including LPFC couplings with aSTR, OFC, aIPL, and pre-PMd. This suggests that the symbolic-pragmatic rule transfer is governed by principles of both, instrumental learning (increasingly tighter coupling between LPFC and aSTR/OFC) and ideomotor learning (increasingly tighter coupling between LPFC and aIPL/pre-PMd). By contrast, increased functional coupling between LPFC and putamen was insensitive to outcome contingency possibly indicating an early stage of habit formation under instructed learning conditions. Copyright © 2012 Elsevier Inc. All rights reserved.

99mTc DMSA scintigraphic findings in renal tuberculosis

International Nuclear Information System (INIS)

Moon, Tae Yong; Kim, Kun Il; Yoon, Chi Soon; Lee, Suck Hong; Kim, Byung Soo

1993-01-01

Evaluations of residual renal function and the therapeutic effectiveness in renal tuberculosis have largely been dependent on intravenous pyelogram or Contrast-CT scan, even though, exact renal functions are not evaluate with there methods. 99m Tc- DMSA is a radiopharmaceutical that is trapped in the functioning tubular cells of the kidney and therefore, quantitative renal function could be evaluated by insuring the counts of renal radioactivity and concomitant evaluation of renal morphology could be passable with the analog images of the radioactivity. The authors retrospectively analyzed 99mTc-DMSA scans of 75 kidneys of 67 patients with confirmed renal tuberculosis. We classified the morphologies of tuberculous kidneys as 6 types. We classified the morphologies of tuberculous kidneys as 6 types such as the type with small cortical defect, with parenchymal ulcerocavernous lesions, ulcerocavernous fistula to pelvis, mass-like defects, contracted kidney with ureter visualization, and the type with non visualization of kidney, corresponding to the characters of renal tuberculous pathogenesis with abscess formation, ulcerocavernous fistula, and fibrosis, and corresponding to the renal anatomy with parenchyma, and pelvocalyceal collecting system. Their mean residual renal functions measured with 99mTc-DMSA uptake rates were 19.0%,18.4%, 7.9%, 12%, 4.1%, 3.4% respectively

Declining resilience of ecosystem functions under biodiversity loss.

Science.gov (United States)

Oliver, Tom H; Isaac, Nick J B; August, Tom A; Woodcock, Ben A; Roy, David B; Bullock, James M

2015-12-08

The composition of species communities is changing rapidly through drivers such as habitat loss and climate change, with potentially serious consequences for the resilience of ecosystem functions on which humans depend. To assess such changes in resilience, we analyse trends in the frequency of species in Great Britain that provide key ecosystem functions--specifically decomposition, carbon sequestration, pollination, pest control and cultural values. For 4,424 species over four decades, there have been significant net declines among animal species that provide pollination, pest control and cultural values. Groups providing decomposition and carbon sequestration remain relatively stable, as fewer species are in decline and these are offset by large numbers of new arrivals into Great Britain. While there is general concern about degradation of a wide range of ecosystem functions, our results suggest actions should focus on particular functions for which there is evidence of substantial erosion of their resilience.

Wavelet-based multiscale analysis of minimum toe clearance variability in the young and elderly during walking.

Science.gov (United States)

Khandoker, Ahsan H; Karmakar, Chandan K; Begg, Rezaul K; Palaniswami, Marimuthu

2007-01-01

As humans age or are influenced by pathology of the neuromuscular system, gait patterns are known to adjust, accommodating for reduced function in the balance control system. The aim of this study was to investigate the effectiveness of a wavelet based multiscale analysis of a gait variable [minimum toe clearance (MTC)] in deriving indexes for understanding age-related declines in gait performance and screening of balance impairments in the elderly. MTC during walking on a treadmill for 30 healthy young, 27 healthy elderly and 10 falls risk elderly subjects with a history of tripping falls were analyzed. The MTC signal from each subject was decomposed to eight detailed signals at different wavelet scales by using the discrete wavelet transform. The variances of detailed signals at scales 8 to 1 were calculated. The multiscale exponent (beta) was then estimated from the slope of the variance progression at successive scales. The variance at scale 5 was significantly (ppathological conditions. Early detection of gait pattern changes due to ageing and balance impairments using wavelet-based multiscale analysis might provide the opportunity to initiate preemptive measures to be undertaken to avoid injurious falls.

Ghrelin and obestatin in thyroid gland - immunohistochemical expression in nodular goiter, papillary and medullary cancer.