Sample records for tc con multidetectores

  1. Application of multidetector-row computed tomography in propeller flap planning.

    PubMed

    Ono, Shimpei; Chung, Kevin C; Hayashi, Hiromitsu; Ogawa, Rei; Takami, Yoshihiro; Hyakusoku, Hiko

    2011-02-01

    The propeller flap is defined as (1) being island-shaped, (2) having an axis that includes the perforators, and (3) having the ability to be rotated around an axis. The advantage of the propeller flap is that it is a pedicle flap that can be applied to cover defects located at the distal ends of the extremities. The specific aims of the authors' study were (1) to evaluate the usefulness of multidetector-row computed tomography in the planning of propeller flaps and (2) to present a clinical case series of propeller flap reconstructions that were planned preoperatively using multidetector-row computed tomography. The authors retrospectively analyzed all cases between April of 2007 and April of 2010 at Nippon Medical School Hospital in Tokyo, where multidetector-row computed tomography was used preoperatively to plan surgical reconstructions using propeller flaps. Thirteen patients underwent 16 flaps using the propeller flap technique. The perforators were identified accurately by multidetector-row computed tomography preoperatively in all cases. This is the first report describing the application of multidetector-row computed tomography in the planning of propeller flaps. Multidetector-row computed tomography is superior to other imaging methods because it demonstrates more precisely the perforator's position and subcutaneous course using high-resolution three-dimensional images. By using multidetector-row computed tomography to preoperatively identify a flap's perforators, the surgeon can better plan the flap design to efficiently conduct the flap surgery.

  2. Patent foramen ovale: detection with nongated multidetector CT.

    PubMed

    Revel, Marie-Pierre; Faivre, Jean-Baptiste; Letourneau, Thierry; Henon, Hilde; Leys, Didier; Delannoy-Deken, Valérie; Remy-Jardin, Martine; Remy, Jacques

    2008-10-01

    To evaluate nongated multidetector computed tomography (CT) in the detection of patent foramen ovale (PFO) and atrial septal aneurysm (ASA) in comparison with transesophageal echocardiography (TEE). The study was approved by the institutional review board, and informed consent was obtained from all patients. One hundred five patients (57 men, 48 women; mean age, 53 years) with a recent stroke underwent TEE and multidetector CT on the same day. After injection of a diluted iodinated contrast material, a series of 2.4-mm-thick transverse images centered on the fossa ovalis were acquired in conjunction with release of the Valsalva maneuver. Two independent radiologists considered PFO present if left atrial enhancement was detected visually before enhancement of the pulmonary veins or if an early peak of left atrial enhancement was found at time-attenuation curve analysis. PFO was detected with 98% specificity (95% confidence interval [CI]: 0.91, 0.99). Overall sensitivity was 55% (95% CI: 0.38, 0.70), ranging from 28% for shunts classified as grade 1 at TEE to 91% for those classified as grade 4 at TEE. Interreader agreement was good (kappa = 0.81). Visual assessment was better than time-attenuation curve analysis, which enabled detection of only 15 of the 40 cases of PFO. Multidetector CT depicted only 22% of cases of ASA. The mean effective radiation dose was 2.3 mSv. Nongated multidetector CT can be used to diagnose high-grade shunts through a PFO, with 91% sensitivity and 98% specificity. Thus, PFO detection, in addition to routine CT evaluation of the lungs, could be indicated in patients with unexplained hypoxemia. (c) RSNA, 2008.

  3. Multi-detector row computed tomography angiography of peripheral arterial disease

    PubMed Central

    Dijkshoorn, Marcel L.; Pattynama, Peter M. T.; Myriam Hunink, M. G.

    2007-01-01

    With the introduction of multi-detector row computed tomography (MDCT), scan speed and image quality has improved considerably. Since the longitudinal coverage is no longer a limitation, multi-detector row computed tomography angiography (MDCTA) is increasingly used to depict the peripheral arterial runoff. Hence, it is important to know the advantages and limitations of this new non-invasive alternative for the reference test, digital subtraction angiography. Optimization of the acquisition parameters and the contrast delivery is important to achieve a reliable enhancement of the entire arterial runoff in patients with peripheral arterial disease (PAD) using fast CT scanners. The purpose of this review is to discuss the different scanning and injection protocols using 4-, 16-, and 64-detector row CT scanners, to propose effective methods to evaluate and to present large data sets, to discuss its clinical value and major limitations, and to review the literature on the validity, reliability, and cost-effectiveness of multi-detector row CT in the evaluation of PAD. PMID:17882427

  4. Multidetector Computed Tomography for Congenital Anomalies of the Aortic Arch: Vascular Rings.

    PubMed

    García-Guereta, Luis; García-Cerro, Estefanía; Bret-Zurita, Montserrat

    2016-07-01

    The development of multidetector computed tomography has triggered a revolution in the study of the aorta and other large vessels and has replaced angiography in the diagnosis of congenital anomalies of the aortic arch, particularly vascular rings. The major advantage of multidetector computed tomography is that it permits clear 3-dimensional assessment of not only vascular structures, but also airway and esophageal compression. The current update aims to summarize the embryonic development of the aortic arch and the developmental anomalies leading to vascular ring formation and to discuss the current diagnostic and therapeutic role of multidetector computed tomography in this field. Copyright © 2016 Sociedad Española de Cardiología. Published by Elsevier España, S.L.U. All rights reserved.

  5. Petamenophis (Padiamenemipet), an Egyptian Child Mummy Protected for Eternity: Revelation by Multidetector Computed Tomography.

    PubMed

    Martina, Maria Cristina; Cesarani, Federico; Boano, Rosa; Fiore Marochetti, Elisa; Gandini, Giovanni

    The objective of our work was to report the most recent findings obtained with multidetector computed tomography of a child mummy from the Roman period (119-123 CE) housed at the Egyptian Museum in Turin, Italy. Multidetector computed tomography and postprocessing were applied to understand the embalming techniques, the nature of a foreign object, and anthropometrical values. The information was compared with that from other mummies that were buried in the same tomb, but today housed in different museums. New information regarding the embalming technique was revealed. Multidetector computed tomography allowed the identification of a knife-like metallic object, probably an amulet for the child's protection in the afterlife. Multidetector computed tomography and image postprocessing confirm their valuable role in noninvasive studies in ancient mummies and provided evidence of a unique cultural practice in the late history of Ancient Egypt such as placing a knife possibly as an amulet.

  6. T staging of gastric cancer: role of multi-detector row CT.

    PubMed

    Kumano, Seishi; Murakami, Takamichi; Kim, Tonsok; Hori, Masatoshi; Iannaccone, Riccardo; Nakata, Saki; Onishi, Hiromitsu; Osuga, Keigo; Tomoda, Kaname; Catalano, Carlo; Nakamura, Hironobu

    2005-12-01

    To evaluate retrospectively the accuracy of multi-detector row computed tomography (CT) in the assessment of serosal invasion in patients with gastric cancer. The Ethics Committee does not require approval or informed consent for retrospective studies. Forty-one consecutive patients (24 men, 17 women; mean age, 68 years) with gastric cancer were included in this study. All patients were given 600 mL of tap water to drink and were positioned prone or supine on the scanning table. The detector row configuration included four detector rows, a section thickness of 1.25 mm, a pitch of 6, and a reconstruction interval of 0.63 mm. Transverse and multiplanar reconstruction images were simultaneously evaluated by two independent observers to assess the depth of tumor invasion in the gastric wall (ie, T stage). T staging at multi-detector row CT was compared with T staging at histologic evaluation (reference standard), which was performed by means of surgical or histologic examination of the resected specimen. We also calculated the sensitivity, specificity, and accuracy of multi-detector row CT for each observer in the assessment of serosal invasion. Analysis of interobserver agreement showed substantial or almost perfect agreement (nonweighted kappa value of 0.78 and weighted kappa value of 0.85). Correct assessment of gastric wall invasion was 80% and 85% for observers 1 and 2, respectively. The sensitivity, specificity, and accuracy of multi-detector row CT in the assessment of serosal invasion were 90%, 95%, and 93%, respectively, for observer 1 and 80%, 97%, and 93%, respectively, for observer 2. Overstaging occurred in six patients, and understaging occurred in five patients. All understaged tumors were scirrhous subtype gastric cancer. Multi-detector row CT scanning of patients with gastric cancer gave 93% accuracy in the assessment of serosal invasion in patients with gastric cancer. RSNA, 2005

  7. Scenes from the past: initial investigation of early jurassic vertebrate fossils with multidetector CT.

    PubMed

    Bolliger, Stephan A; Ross, Steffen; Thali, Michael J; Hostettler, Bernhard; Menkveld-Gfeller, Ursula

    2012-01-01

    The study of fossils permits the reconstruction of past life on our planet and enhances our understanding of evolutionary processes. However, many fossils are difficult to recognize, being encased in a lithified matrix whose tedious removal is required before examination is possible. The authors describe the use of multidetector computed tomography (CT) in locating, identifying, and examining fossil remains of crocodilians (Mesosuchia) embedded in hard shale, all without removing the matrix. In addition, they describe how three-dimensional (3D) reformatted CT images provided details that were helpful for extraction and preparation. Multidetector CT can help experienced paleontologists localize and characterize fossils in the matrix of a promising rock specimen in a nondestructive manner. Moreover, with its capacity to generate highly accurate 3D images, multidetector CT can help determine whether the fossils warrant extraction and can assist in planning the extraction process. Thus, multidetector CT may well become an invaluable tool in the field of paleoradiology.

  8. Characterizing string-of-pearls colloidal silica by multidetector hydrodynamic chromatography and comparison to multidetector size-exclusion chromatography, off-line multiangle static light scattering, and transmission electron microscopy.

    PubMed

    Brewer, Amandaa K; Striegel, André M

    2011-04-15

    The string-of-pearls-type morphology is ubiquitous, manifesting itself variously in proteins, vesicles, bacteria, synthetic polymers, and biopolymers. Characterizing the size and shape of analytes with such morphology, however, presents a challenge, due chiefly to the ease with which the "strings" can be broken during chromatographic analysis or to the paucity of information obtained from the benchmark microscopy and off-line light scattering methods. Here, we address this challenge with multidetector hydrodynamic chromatography (HDC), which has the ability to determine, simultaneously, the size, shape, and compactness and their distributions of string-of-pearls samples. We present the quadruple-detector HDC analysis of colloidal string-of-pearls silica, employing static multiangle and quasielastic light scattering, differential viscometry, and differential refractometry as detection methods. The multidetector approach shows a sample that is broadly polydisperse in both molar mass and size, with strings ranging from two to five particles, but which also contains a high concentration of single, unattached "pearls". Synergistic combination of the various size parameters obtained from the multiplicity of detectors employed shows that the strings with higher degrees of polymerization have a shape similar to the theory-predicted shape of a Gaussian random coil chain of nonoverlapping beads, while the strings with lower degrees of polymerization have a prolate ellipsoidal shape. The HDC technique is contrasted experimentally with multidetector size-exclusion chromatography, where, even under extremely gentle conditions, the strings still degraded during analysis. Such degradation is shown to be absent in HDC, as evidenced by the fact that the molar mass and radius of gyration obtained by HDC with multiangle static light scattering detection (HDC/MALS) compare quite favorably to those determined by off-line MALS analysis under otherwise identical conditions. The

  9. Diagnosing Early Ischemic Changes with the Latest-Generation Flat Detector CT: A Comparative Study with Multidetector CT.

    PubMed

    Maier, I L; Leyhe, J R; Tsogkas, I; Behme, D; Schregel, K; Knauth, M; Schnieder, M; Liman, J; Psychogios, M-N

    2018-05-01

    One-stop management of mechanical thrombectomy-eligible patients with large-vessel occlusion represents an innovative approach in acute stroke treatment. This approach reduces door-to-reperfusion times by omitting multidetector CT, using flat detector CT as pre-mechanical thrombectomy imaging. The purpose of this study was to compare the diagnostic performance of the latest-generation flat detector CT with multidetector CT. Prospectively derived data from patients with ischemic stroke with large-vessel occlusion and mechanical thrombectomy were analyzed in this monocentric study. All included patients underwent multidetector CT before referral to our comprehensive stroke center and flat detector CT in the angiography suite before mechanical thrombectomy. Diagnosis of early ischemic signs, quantified by the ASPECTS, was compared between modalities using cross tables, the Pearson correlation, and Bland-Altman plots. The predictive value of multidetector CT- and flat detector CT-derived ASPECTS for functional outcome was investigated using area under the receiver operating characteristic curve analysis. Of 25 patients, 24 (96%) had flat detector CT with sufficient diagnostic quality. Median multidetector CT and flat detector CT ASPECTSs were 7 (interquartile range, 5.5-9 and 4.25-8, respectively) with a mean period of 143.6 ± 49.5 minutes between both modalities. The overall sensitivity was 85.1% and specificity was 83.1% for flat detector CT ASPECTS compared with multidetector CT ASPECTS as the reference technique. Multidetector CT and flat detector CT ASPECTS were strongly correlated ( r = 0.849, P < .001) and moderately predicted functional outcome (area under the receiver operating characteristic curve, 0.738; P = .007 and .715; P = .069, respectively). Determination of ASPECTS on flat detector CT is feasible, showing no significant difference compared with multidetector CT ASPECTS and a similar predictive value for functional outcome. Our findings support the

  10. Monte: A compact and versatile multidetector system based on monolithic telescopes

    NASA Astrophysics Data System (ADS)

    Amorini, F.; Bonanno, A.; Cardella, G.; di Pietro, A.; Fallica, G.; Figuera, P.; Morea, A.; Musumarra, A.; Papa, M.; Pappalardo, G.; Pinto, A.; Rizzo, F.; Tian, W.; Tudisco, S.; Valvo, G.

    2005-09-01

    We present the characteristics of a new multidetector based on monolithic silicon telescopes: MONTE. By using high-energy ion implantation techniques, the ΔE and residual energy stages of such telescopes have been integrated on the same silicon chip, obtaining extremely thin ΔE stages of the order of 1 μm. This allowed one to obtain a very low charge identification energy threshold and a very good β background suppression in reactions induced by radioactive ion beams. The multidetector has a modular structure and can be assembled in different geometrical configurations according to experimental needs.

  11. Thermal Expansion Behavior in TcO2. Toward Breaking the Tc-Tc Bond.

    PubMed

    Reynolds, Emily; Zhang, Zhaoming; Avdeev, Maxim; Thorogood, Gordon J; Poineau, Frederic; Czerwinski, Kenneth R; Kimpton, Justin A; Kennedy, Brendan J

    2017-08-07

    The structure of TcO 2 between 25 and 1000 °C has been determined in situ using X-ray powder diffraction methods and is found to remain monoclinic in space group P2 1 /c. Thermal expansion in TcO 2 is highly anisotropic, with negative thermal expansion of the b axis observed above 700 °C. This is the result of an anomalous expansion along the a axis that is a consequence of weakening of the Tc-Tc bonds.

  12. Relationship between noise, dose, and pitch in cardiac multi-detector row CT.

    PubMed

    Primak, Andrew N; McCollough, Cynthia H; Bruesewitz, Michael R; Zhang, Jie; Fletcher, Joel G

    2006-01-01

    In spiral computed tomography (CT), dose is always inversely proportional to pitch. However, the relationship between noise and pitch (and hence noise and dose) depends on the scanner type (single vs multi-detector row) and reconstruction mode (cardiac vs noncardiac). In single detector row spiral CT, noise is independent of pitch. Conversely, in noncardiac multi-detector row CT, noise depends on pitch because the spiral interpolation algorithm makes use of redundant data from different detector rows to decrease noise for pitch values less than 1 (and increase noise for pitch values > 1). However, in cardiac spiral CT, redundant data cannot be used because such data averaging would degrade the temporal resolution. Therefore, the behavior of noise versus pitch returns to the single detector row paradigm, with noise being independent of pitch. Consequently, since faster rotation times require lower pitch values in cardiac multi-detector row CT, dose is increased without a commensurate decrease in noise. Thus, the use of faster rotation times will improve temporal resolution, not alter noise, and increase dose. For a particular application, the higher dose resulting from faster rotation speeds should be justified by the clinical benefits of the improved temporal resolution. RSNA, 2006

  13. Multidetector CT of blunt traumatic venous injuries in the chest, abdomen, and pelvis.

    PubMed

    Holly, Brian P; Steenburg, Scott D

    2011-01-01

    Venous injuries as a result of blunt trauma are rare. Even though current protocols for multidetector computed tomography (CT) of patients with trauma are designed to evaluate primarily the solid organs and arteries, blunt venous injuries may nevertheless be identified, or at least suspected, on the basis of the multidetector CT findings. Venous injuries are associated with high morbidity and mortality rates. Diagnosis of a possible venous injury is crucial because the physical findings of a venous injury are nonspecific and may be absent. This article aims to make the radiologist aware of various venous injuries caused by blunt trauma and to provide helpful hints to aid in the identification of venous injuries. Multidetector CT technology, in combination with interactive manipulation of the raw dataset, can be useful in the creation of multiplanar reconstructed images and in the identification of a venous injury caused by blunt trauma. Familiarity with direct and indirect signs of venous injuries, as well as with examples of blunt traumatic venous injuries in the chest, abdomen, and pelvis, will help in the diagnosis of these injuries.

  14. Ectopic Multinodular Goiter: Multidetector Computed Tomography Findings

    PubMed Central

    Karakaya, Afak Durur; Kantarci, Mecit; Yalcin, Ahmet; Demir, Berrin

    2008-01-01

    The thyroid is the first endocrine gland to form during embryogenesis. At this stage, incomplete or anomalous migration of thyroid tissue causes ectopic localization of the gland. In our case, a 55-year-old woman who was evaluated via ultrasonography (USG) and multi-detector computed tomography (MDCT) had no thyroid gland at the normal location, but did have ectopic thyroid tissue in the left submandibular and submental regions. PMID:25610021

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

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Um, Wooyong; Luksic, Steven A.; Wang, Guohui

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

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

    DOE PAGES

    Um, Wooyong; Luksic, Steven A.; Wang, Guohui; ...

    2017-09-07

    We present that technetium ( 99Tc) immobilization by doping into iron oxide mineral phases may alleviate the problems with Tc volatility during vitrification of nuclear waste. Because reduced Tc, Tc(IV), substitutes for Fe(III) in the crystal structure by a process of Tc reduction from Tc(VII) to Tc(IV) followed by co-precipitation of Fe oxide minerals, two Tc-incorporated Fe minerals (Tc-goethite and Tc-magnetite/maghemite) were prepared and tested for Tc retention in glass melt samples at temperatures between 600 and 1000 °C. After being cooled, the solid glass specimens prepared at different temperatures at 600, 800, and 1000 °C were analyzed for Tcmore » oxidation state using Tc K-edge XANES. In most samples, Tc was partially (<60%) oxidized from Tc(IV) to Tc(VII) as the melt temperature increased up to 600 °C. However, most of Tc(IV) was completely (>95%) oxidized to Tc(VII) at temperature above 800 °C. Tc retention in glass melt samples prepared using Tc-incorporated Fe minerals were slightly higher (~10%) than in glass prepared using KTcO4 because of limited and delayed Tc volatilization.« less

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

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Um, Wooyong; Luksic, Steven A.; Wang, Guohui

    We present that technetium ( 99Tc) immobilization by doping into iron oxide mineral phases may alleviate the problems with Tc volatility during vitrification of nuclear waste. Because reduced Tc, Tc(IV), substitutes for Fe(III) in the crystal structure by a process of Tc reduction from Tc(VII) to Tc(IV) followed by co-precipitation of Fe oxide minerals, two Tc-incorporated Fe minerals (Tc-goethite and Tc-magnetite/maghemite) were prepared and tested for Tc retention in glass melt samples at temperatures between 600 and 1000 °C. After being cooled, the solid glass specimens prepared at different temperatures at 600, 800, and 1000 °C were analyzed for Tcmore » oxidation state using Tc K-edge XANES. In most samples, Tc was partially (<60%) oxidized from Tc(IV) to Tc(VII) as the melt temperature increased up to 600 °C. However, most of Tc(IV) was completely (>95%) oxidized to Tc(VII) at temperature above 800 °C. Tc retention in glass melt samples prepared using Tc-incorporated Fe minerals were slightly higher (~10%) than in glass prepared using KTcO4 because of limited and delayed Tc volatilization.« less

  18. Right heart on multidetector CT

    PubMed Central

    Gopalan, D

    2011-01-01

    Right ventricular function plays an integral role in the pathogenesis and outcome of many cardiovascular diseases. Imaging the right ventricle has long been a challenge because of its complex geometry. In recent years there has been a tremendous expansion in multidetector row CT (MDCT) and its cardiac applications. By judicious modification of contrast medium protocol, it is possible to achieve good opacification of the right-sided cardiac chambers, thereby paving the way for exploring the overshadowed right heart. This article will describe the key features of right heart anatomy, review MDCT acquisition techniques, elaborate the various morphological and functional information that can be obtained, and illustrate some important clinical conditions associated with an abnormal right heart. PMID:22723537

  19. Multidetector computed tomographic pulmonary angiography in patients with a high clinical probability of pulmonary embolism.

    PubMed

    Moores, L; Kline, J; Portillo, A K; Resano, S; Vicente, A; Arrieta, P; Corres, J; Tapson, V; Yusen, R D; Jiménez, D

    2016-01-01

    ESSENTIALS: When high probability of pulmonary embolism (PE), sensitivity of computed tomography (CT) is unclear. We investigated the sensitivity of multidetector CT among 134 patients with a high probability of PE. A normal CT alone may not safely exclude PE in patients with a high clinical pretest probability. In patients with no clear alternative diagnosis after CTPA, further testing should be strongly considered. Whether patients with a negative multidetector computed tomographic pulmonary angiography (CTPA) result and a high clinical pretest probability of pulmonary embolism (PE) should be further investigated is controversial. This was a prospective investigation of the sensitivity of multidetector CTPA among patients with a priori clinical assessment of a high probability of PE according to the Wells criteria. Among patients with a negative CTPA result, the diagnosis of PE required at least one of the following conditions: ventilation/perfusion lung scan showing a high probability of PE in a patient with no history of PE, abnormal findings on venous ultrasonography in a patient without previous deep vein thrombosis at that site, or the occurrence of venous thromboembolism (VTE) in a 3-month follow-up period after anticoagulation was withheld because of a negative multidetector CTPA result. We identified 498 patients with a priori clinical assessment of a high probability of PE and a completed CTPA study. CTPA excluded PE in 134 patients; in these patients, the pooled incidence of VTE was 5.2% (seven of 134 patients; 95% confidence interval [CI] 1.5-9.0). Five patients had VTEs that were confirmed by an additional imaging test despite a negative CTPA result (five of 48 patients; 10.4%; 95% CI 1.8-19.1), and two patients had objectively confirmed VTEs that occurred during clinical follow-up of at least 3 months (two of 86 patients; 2.3%; 95% CI 0-5.5). None of the patients had a fatal PE during follow-up. A normal multidetector CTPA result alone may not safely

  20. Monitoring Tc dynamics in a bioreduced sediment: an investigation with gamma camera imaging of (99m)Tc-pertechnetate and (99m)Tc-DTPA.

    PubMed

    Vandehey, Nicholas T; O'Neil, James P; Slowey, Aaron J; Boutchko, Rostyslav; Druhan, Jennifer L; Moses, William W; Nico, Peter S

    2012-11-20

    We demonstrate the utility of nuclear medical imaging technologies and a readily available radiotracer, [(99m)Tc]TcO(4)(-), for the noninvasive monitoring of Fe(II) production in acetate-stimulated sediments from Old Rifle, CO, USA. Microcosms consisting of sediment in artificial groundwater media amended with acetate were probed by repeated injection of radiotracer over three weeks. Gamma camera imaging was used to noninvasively quantify the rate and extent of [(99m)Tc]TcO(4)(-) partitioning from solution to sediment. Aqueous Fe(II) and sediment-associated Fe(II) were also measured and correlated with the observed tracer behavior. For each injection of tracer, curves of (99m)Tc concentration in solution vs time were fitted to an analytic function that accounts for both the observed rate of sedimentation as well as the rate of (99m)Tc association with the sediment. The rate and extent of (99m)Tc association with the biostimulated sediment correlated well with the production of Fe(II), and a mechanism of [(99m)Tc]TcO(4)(-) reduction via reaction with surface-bound Fe(II) to form an immobile Tc(IV) species was inferred. After three weeks of bioreduction, a subset of microcosms was aerated in order to reoxidize the Fe(II) to Fe(III), which also destroyed the affinity of the [(99m)Tc]TcO(4)(-) for the sediments. However, within 3 days postoxidation, the rate of Tc(VII) reduction was faster than immediately before oxidation implying a rapid return to more extensive bioreduction. Furthermore, aeration soon after a tracer injection showed that sediment-bound Tc(IV) is rapidly resolubilized to Tc(VII). In contrast to the [(99m)Tc]TcO(4)(-), a second commercially available tracer, (99m)Tc-DTPA (diethylenetriaminepentaacetic acid), had minimal association with sediment in both controls and biostimulated sediments. These experiments show the promise of [(99m)Tc]TcO(4)(-) and (99m)Tc-DTPA as noninvasive imaging probes for a redox-sensitive radiotracer and a conservative flow

  1. Altered [99mTc]Tc-MDP biodistribution from neutron activation sourced 99Mo.

    PubMed

    Demeter, Sandor; Szweda, Roman; Patterson, Judy; Grigoryan, Marine

    2018-01-01

    Given potential worldwide shortages of fission sourced 99 Mo/ 99m Tc medical isotopes there is increasing interest in alternate production strategies. A neutron activated 99 Mo source was utilized in a single center phase III open label study comparing 99m Tc, as 99m Tc Methylene Diphosphonate ([ 99m Tc]Tc-MDP), obtained from solvent generator separation of neutron activation produced 99 Mo, versus nuclear reactor produced 99 Mo (e.g., fission sourced) in oncology patients for which an [ 99m Tc]Tc-MDP bone scan would normally have been indicated. Despite the investigational [ 99m Tc]Tc-MDP passing all standard, and above standard of care, quality assurance tests, which would normally be sufficient to allow human administration, there was altered biodistribution which could lead to erroneous clinical interpretation. The cause of the altered biodistribution remains unknown and requires further research.

  2. [Sigmoid endometriosis: a diagnostic dilemma on multidetector CT].

    PubMed

    Telegrafo, Michele; Lorusso, Valentina; Rubini, Giuseppe; Rella, Leonarda; Pezzolla, Angela; Stabile Ianora, Amato Antonio; Moschetta, Marco

    2013-01-01

    Intestinal endometriosis represents a common condition that occurs particularly in women of reproductive age. The gastrointestinal tract is the third most common localization of endometriosis, after the ovaries and the peritoneum, and recto-sigmoid tract is involved in 70% of cases. Recto-sigmoid endometriosis has to be differentiated from other diseases of large bowel, especially in patients without a history of endometriosis. We report a case of sigmoid endometriosis which represented a diagnostic dilemma on multidetector computed tomography.

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

    PubMed Central

    Alessio, Glaucia Diniz; de Araújo, Fernanda Fortes; Côrtes, Denise Fonseca; Sales Júnior, Policarpo Ademar; Lima, Daniela Cristina; Gomes, Matheus de Souza; do Amaral, Laurence Rodrigues; Xavier, Marcelo Antônio Pascoal; Teixeira-Carvalho, Andréa; Martins-Filho, Olindo Assis; de Lana, Marta

    2017-01-01

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

  4. Multidetector Scattering as a Probe of Local Structure in Disordered Phases

    NASA Astrophysics Data System (ADS)

    Clark, Noel A.; Ackerson, Bruce J.; Hurd, Alan J.

    1983-05-01

    The local translational structure of a two-dimensional colloidal liquid is observed by use of cross correlation of the intensity fluctuations of light scattered by the liquid through two different wave vectors. The utility of multidetector scattering in probing multipoint correlations in disordered phases is thereby demonstrated unambiguously.

  5. Diagnostic Performance of Gadoxetic Acid-enhanced Liver MR Imaging versus Multidetector CT in the Detection of Dysplastic Nodules and Early Hepatocellular Carcinoma.

    PubMed

    Kim, Bo Ram; Lee, Jeong Min; Lee, Dong Ho; Yoon, Jeong Hee; Hur, Bo Yun; Suh, Kyung Suk; Yi, Nam-Joon; Lee, Kyung Boon; Han, Joon Koo

    2017-10-01

    Purpose To compare the diagnostic performance of gadoxetic acid-enhanced liver magnetic resonance (MR) imaging with that of contrast material-enhanced multidetector computed tomography (CT) in the detection of borderline hepatocellular nodules in patients with liver cirrhosis and to determine the Liver Imaging Reporting and Data System (LI-RADS) categories of these detected nodules. Materials and Methods The institutional review board approved this retrospective study and waived the informed consent requirement. Sixty-eight patients with pathologically proven dysplastic nodules (DNs) (low-grade DNs, n = 20; high-grade DNs, n = 17), early hepatocellular carcinomas (HCCs) (n = 42), or progressed HCCs (n = 33) underwent gadoxetic acid-enhanced MR imaging and multidetector CT. An additional 57 patients without any DNs or HCCs in the explanted livers were included as control subjects. Three radiologists independently graded the presence of liver nodules on a five-point confidence scale and assigned LI-RADS categories by using imaging findings. Jackknife alternative free-response receiver operating characteristics (JAFROC) software was used to compare the diagnostic accuracy of each modality in lesion detection. Results Reader-averaged figures of merit estimated with JAFROC software to detect hepatocellular nodules were 0.774 for multidetector CT and 0.842 for MR imaging (P = .002). Readers had significantly higher detection sensitivity for early HCCs with MR imaging than with multidetector CT (78.6% vs 52.4% [P = .001], 71.4% vs 50.0% [P = .011], and 73.8% vs 50.0% [P = .001], respectively). A high proportion of overall detected early HCCs at multidetector CT (59.4%) and MR imaging (72.3%) were categorized as LI-RADS category 4. Most early HCCs (76.2%) and high-grade DNs (82.4%) demonstrated hypointensity on hepatobiliary phase images. In total, 30 more LI-RADS category 4 early HCCs were identified with MR imaging than with multidetector CT across all readers

  6. Development of Tc(IV)-Incorporated Fe Minerals to Enhance 99Tc Retention in Glass Waste Form

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Um, Wooyong; Luksic, Steven A.; Wang, Guohui

    Iron minerals have been considered to be good hosts for Tc immobilization because the Tc(IV) ion substitutes for Fe(III) in the crystal structure of the Fe oxide due to similarities in (1) cation size [Tc(IV) = 78.5 pm ; Fe(III) = 69 or 78.5 pm], (2) metal-oxygen interatomic distance (Tc—O = 0.199 nm, Fe—O = 0.203 nm), (3) number of coordinating oxygen atoms (both 6-fold coordinated), and (4) the redox potential (Eh=ca. +20 mV at pH = 7) for a redox couple between Tc(VII)/Tc(IV) and Fe(III)/Fe(II). Magnetite, maghemite, and trevorite are iron oxide minerals and all belong to spinel mineralmore » group. Laboratory testing shows that Tc can be removed from aqueous waste solutions by a process of Tc reduction from Tc(VII) to Tc(IV) followed by co-precipitation with iron oxide minerals during recrystallization of Fe(OH)2(s) used as an initial solid precursor. X-ray absorption near edge structure (XANES) spectroscopy confirmed that Tc was in the +4 oxidation state in final Tc-Fe minerals. The Tc-incorporated Fe minerals were also tested for Tc retention in glass melts at different temperatures between 600 – 1,000 oC in a furnace. After being cooled in air, the solid glass specimens collected at different temperatures were analyzed for Tc oxidation state using XANES and Tc retention using liquid scintillation counting (LSC). Even though Tc(IV) started to reoxidize at 600 oC, Tc retention in the final glass specimen prepared with Tc-incorporated Fe mineral even at high temperatures was at least two times higher than glass prepared with KTcO4 salt. Higher Tc retention in glass is considered to result from limited and delayed Tc volatilization process due to Fe mineral encapsulation for Tc. Therefore, the results showing the presence of Tc(IV) in the Fe mineral structure indicate strong possibility to enhance Tc retention in borosilicate glass as well as to reduce the remediation costs at the Hanford Site.« less

  7. Toroid cavity/coil NMR multi-detector

    DOEpatents

    Gerald, II, Rex E.; Meadows, Alexander D.; Gregar, Joseph S.; Rathke, Jerome W.

    2007-09-18

    An analytical device for rapid, non-invasive nuclear magnetic resonance (NMR) spectroscopy of multiple samples using a single spectrometer is provided. A modified toroid cavity/coil detector (TCD), and methods for conducting the simultaneous acquisition of NMR data for multiple samples including a protocol for testing NMR multi-detectors are provided. One embodiment includes a plurality of LC resonant circuits including spatially separated toroid coil inductors, each toroid coil inductor enveloping its corresponding sample volume, and tuned to resonate at a predefined frequency using a variable capacitor. The toroid coil is formed into a loop, where both ends of the toroid coil are brought into coincidence. Another embodiment includes multiple micro Helmholtz coils arranged on a circular perimeter concentric with a central conductor of the toroid cavity.

  8. The utility of 64 channel multidetector CT angiography for evaluating the renal vascular anatomy and possible variations: a pictorial essay.

    PubMed

    Kumar, Sheo; Neyaz, Zafar; Gupta, Archna

    2010-01-01

    The increased use of laparoscopic nephrectomy and nephron-sparing surgery has prompted the need for a more detailed radiological evaluation of the renal vascular anatomy. Multidetector CT angiography is a fast and accurate modality for assessing the precise anatomy of the renal vessels. In this pictorial review, we present the multidetector CT angiography appearances of the normal renal vascular anatomy and a spectrum of various anomalies that require accurate vascular depiction before undergoing surgical treatment.

  9. PREFACE: 2014 Joint IMEKO TC1-TC7-TC13 Symposium: Measurement Science Behind Safety and Security

    NASA Astrophysics Data System (ADS)

    Sousa, João A.; Ribeiro, Álvaro S.; Filipe, Eduarda

    2015-02-01

    The 2014 Joint IMEKO (International Measurement Confederation) TC1-TC7-TC13 Symposium was organized by RELACRE - Portuguese Association of Accredited Laboratories and the Portuguese Society for Metrology, on 3-5 September 2014. The work of this symposium is reported in this volume. The scope of the symposium includes the main topics covered by the above Technical Committees: - TC1 Education and Training in measurement and Instrumentation - TC7 Measurement Science - TC13 Measurements in Biology and Medicine The effort towards excellence of previous events, in this well established series, is maintained. There has been a special focus on measurement science behind safety and security, with the aim of highlighting the interdisciplinary character of measurement science and the importance of metrology in our daily lives. The discussion was introduced by keynote lectures on measurement challenges in biometrics, health monitoring and social sciences, to promote useful interactions with scientists from different disciplines. The Symposium was attended by experts working in these areas from 18 countries, including USA, Japan and China, and provided a useful forum for them to share and exchange their work and ideas. In total over fifty papers are included in the volume, organized according to the presentation sessions. Each paper was independently peer-reviewed by two reviewers from a distinguished international panel. The Symposium was held in Funchal, capital of Madeira Islands, known as the Atlantic Pearl. This wonderful Atlantic archipelago, formed by Madeira and Porto Santo islands, discovered in the 14th century, was chosen to host the 2014 IMEKO TC1-TC7-TC13 Joint Symposium ''Measurement Science behind Safety and Security''. It was the first territory discovered by the Portuguese sailors, when set out to discover a new world, in an epic journey where instrumentation and quality of measurement played a central role in the success of the enterprise, and gave an

  10. Comparison of the Diagnostic Image Quality of the Canine Maxillary Dentoalveolar Structures Obtained by Cone Beam Computed Tomography and 64-Multidetector Row Computed Tomography.

    PubMed

    Soukup, Jason W; Drees, Randi; Koenig, Lisa J; Snyder, Christopher J; Hetzel, Scott; Miles, Chanda R; Schwarz, Tobias

    2015-01-01

    The objective of this blinded study was to validate the use of cone beam computed tomography (C) for imaging of the canine maxillary dentoalveolar structures by comparing its diagnostic image quality with that of 64-multidetector row CT Sagittal slices of a tooth-bearing segment of the maxilla of a commercially purchased dog skull embedded in methylmethacrylate were obtained along a line parallel with the dental arch using a commercial histology diamond saw. The slice of tooth-bearing bone that best depicted the dentoalveolar structures was chosen and photographed. The maxillary segment was imaged with cone beam CT and 64-multidetector row CT. Four blinded evaluators compared the cone beam CT and 64-multidetector row CT images and image quality was scored as it related to the anatomy of dentoalveolar structures. Trabecular bone, enamel, dentin, pulp cavity, periodontal ligament space, and lamina dura were scored In addition, a score depicting the evaluators overall impression of the image was recorded. Images acquired with cone beam CT were found to be significantly superior in image quality to images acquired with 64-multidetector row CT overall, and in all scored categories. In our study setting cone beam CT was found to be a valid and clinically superior imaging modality for the canine maxillary dentoalveolar structures when compared to 64-multidetector row CT.

  11. Comparison of the Diagnostic Image Quality of the Canine Maxillary Dentoalveolar Structures Obtained by Cone Beam Computed Tomography and 64-Multidetector Row Computed Tomography

    PubMed Central

    Soukup, Jason W.; Drees, Randi; Koenig, Lisa J.; Snyder, Christopher J.; Hetzel, Scott; Miles, Chanda R.; Schwarz, Tobias

    2016-01-01

    Summary The objective of this blinded study was to validate the use of cone beam computed tomography (CT) for imaging of the canine maxillary dentoalveolar structures by comparing its diagnostic image quality with that of 64-multidetector row CT. Sagittal slices of a tooth-bearing segment of the maxilla of a commercially purchased dog skull embedded in methyl methacrylate were obtained along a line parallel with the dental arch using a commercial histology diamond saw. The slice of tooth-bearing bone that best depicted the dentoalveolar structures was chosen and photographed. The maxilla segment was imaged with cone beam CT and 64-multidetector row CT. Four blinded evaluators compared the cone beam CT and 64-multidetector row CT images and image quality was scored as it related to the anatomy of dentoalveolar structures. Trabecular bone, enamel, dentin, pulp cavity, periodontal ligament space, and lamina dura were scored. In addition, a score depicting the evaluators overall impression of the image was recorded. Images acquired with cone beam CT were found to be significantly superior in image quality to images acquired with 64-multidetector row CT overall, and in all scored categories. In our study setting, cone beam CT was found to be a valid and clinically superior imaging modality for the canine maxillary dentoalveolar structures when compared to 64-multidetector row CT. PMID:26415384

  12. Novel wearable and wireless ring-type pulse oximeter with multi-detectors.

    PubMed

    Huang, Cheng-Yang; Chan, Ming-Che; Chen, Chien-Yue; Lin, Bor-Shyh

    2014-09-19

    The pulse oximeter is a popular instrument to monitor the arterial oxygen saturation (SPO2). Although a fingertip-type pulse oximeter is the mainstream one on the market at present, it is still inconvenient for long-term monitoring, in particular, with respect to motion. Therefore, the development of a wearable pulse oximeter, such as a finger base-type pulse oximeter, can effectively solve the above issue. However, the tissue structure of the finger base is complex, and there is lack of detailed information on the effect of the light source and detector placement on measuring SPO2. In this study, the practicability of a ring-type pulse oximeter with a multi-detector was investigated by optical human tissue simulation. The optimal design of a ring-type pulse oximeter that can provide the best efficiency of measuring SPO2 was discussed. The efficiency of ring-type pulse oximeters with a single detector and a multi-detector was also discussed. Finally, a wearable and wireless ring-type pulse oximeter was also implemented to validate the simulation results and was compared with the commercial fingertip-type pulse oximeter.

  13. Novel Wearable and Wireless Ring-Type Pulse Oximeter with Multi-Detectors

    PubMed Central

    Huang, Cheng-Yang; Chan, Ming-Che; Chen, Chien-Yue; Lin, Bor-Shyh

    2014-01-01

    The pulse oximeter is a popular instrument to monitor the arterial oxygen saturation (SPO2). Although a fingertip-type pulse oximeter is the mainstream one on the market at present, it is still inconvenient for long-term monitoring, in particular, with respect to motion. Therefore, the development of a wearable pulse oximeter, such as a finger base-type pulse oximeter, can effectively solve the above issue. However, the tissue structure of the finger base is complex, and there is lack of detailed information on the effect of the light source and detector placement on measuring SPO2. In this study, the practicability of a ring-type pulse oximeter with a multi-detector was investigated by optical human tissue simulation. The optimal design of a ring-type pulse oximeter that can provide the best efficiency of measuring SPO2 was discussed. The efficiency of ring-type pulse oximeters with a single detector and a multi-detector was also discussed. Finally, a wearable and wireless ring-type pulse oximeter was also implemented to validate the simulation results and was compared with the commercial fingertip-type pulse oximeter. PMID:25244586

  14. Use of Tc-99m-galactosyl-neoglycoalbumin (Tc-NGA) to determine hepatic blood flow

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Stadalnik, R.C.; Vera, D.R.; Woodle, E.S.

    1984-01-01

    Tc-NGA is a new liver radiopharmaceutical which binds to a hepatocyte-specific membrane receptor. Three characteristics of Tc-NGA can be exploited in the measurement of hepatic blood flow (HBF): 1) ability to alter the affinity of Tc-NGA for its receptor by changing the galactose: albumin ratio; 2) ability to achieve a high specific activity with Tc-99m labeling; and 3) ability to administer a high molar dose of Tc-NGA without physiologic side effects. In addition, kinetic modeling of Tc-NGA dynamic data can provide estimates of hepatic receptor concentration. In experimental studies in young pigs, HBF was determined using two techniques: 1) kineticmore » modeling of dynamic data using moderate affinity, low specific activity Tc-NGA (Group A, n=12); and 2) clearance (CL) technique using high affinity, high specific activity Tc-NGA (Group B, n=4). In both groups, HBF was determined simultaneously by continuous infusion of indocyanine green (CI-ICG) with hepatic vein sampling. Regression analysis of HBF measurements obtained with the Tc-NGA kinetic modeling technique and the CI-ICG technique (Group A) revealed good correlation between the two techniques (r=0.802, p=0.02). Similarly, HBF determination by the clearance technique (Group B) provided highly accurate measurements when compared to the CI-ICG technique. Hepatic blood flow measurements by the clearance technique (CL-NGA) fell within one standard deviation of the error associated with each CI-ICG HBF measurement (all CI-ICG standard deviations were less than 10%).« less

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

    PubMed

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

    2017-08-01

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

  16. Multidetector CT evaluation of the postoperative pancreas.

    PubMed

    Yamauchi, Fernando I; Ortega, Cinthia D; Blasbalg, Roberto; Rocha, Manoel S; Jukemura, José; Cerri, Giovanni G

    2012-01-01

    Several pancreatic diseases may require surgical treatment, with most of these procedures classified as resection or drainage. Resection procedures, which are usually performed to remove pancreatic tumors, include pancreatoduodenectomy, central pancreatectomy, distal pancreatectomy, and total pancreatectomy. Drainage procedures are usually performed to treat chronic pancreatitis after the failure of medical therapy and include the Puestow and Frey procedures. The type of surgery depends not only on the patient's symptoms and the location of the disease, but also on the expertise of the surgeon. Radiologists should become familiar with these surgical procedures to better understand postoperative changes in anatomic findings. Multidetector computed tomography is the modality of choice for identifying normal findings after surgery, postoperative complications, and tumor recurrence in patients who have undergone pancreatic surgery. RSNA, 2012

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

    PubMed

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

    2018-05-30

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

  18. Toward organometallic (99m)Tc imaging agents: synthesis of water-stable (99)Tc-NHC complexes.

    PubMed

    Benz, Michael; Spingler, Bernhard; Alberto, Roger; Braband, Henrik

    2013-11-20

    (99)Tc(V)O2-NHC complexes containing monodentate and bidentate N-heterocyclic carbenes (NHCs) have been prepared by the reactions of [TcO(glyc)2](-) (glyc = ethyleneglycolato) with 1,3-dimethylimidazoline-2-ylidene (L1), 1,1'-methylene-3,3'-dimethyl-4,4'-diimidazoline-2,2'-diylidene (L2), and 1,1'-methylene-3,3'-diethyl-4,4'-diimidazoline-2,2'-diylidene (L3) in THF. The resulting complexes were fully characterized and their stabilities investigated. While complexes with monodentate NHCs only are hydrolytically unstable, complexes containing bidentate NHCs are water-stable over a broad pH range. The high water stability allows interconversion of the {(99)Tc(V)O2}(+) core into {(99)Tc(V)OCl}(2+) with HCl as the H(+) and Cl(-) source. An alternative procedure to obtain (99)Tc(V)O2-NHC complexes is the in situ deprotonation of imidazolium salts, enabling the preparation of (99)Tc(V)O2-NHC compounds without free NHCs, thus increasing the scope of NHC ligands drastically. The remarkable stability and pH-controllable reactivity of the new complexes underlines the potential of NHCs as stabilizing ligands for (99)Tc complexes and paves the way for the first (99m)Tc-NHC complexes in the future.

  19. Multidetector CT of musculoskeletal disease in the pediatric patient: principles, techniques, and clinical applications.

    PubMed

    Fayad, Laura M; Johnson, Pamela; Fishman, Elliot K

    2005-01-01

    Computed tomography (CT) plays an important role in the evaluation of musculoskeletal disease in the pediatric patient. With the advent of high-performance 16-section multidetector CT, images can be produced with subsecond gantry rotation times and with submillimeter acquisition, which yields true isotropic high-resolution volume data sets; these features are not attainable with older spiral CT technology. Such capabilities are particularly helpful in the evaluation of pediatric patients by virtually eliminating the need for sedation and minimizing dependence on patient cooperation. The role of three-dimensional (3D) volume imaging in the evaluation of pediatric musculoskeletal disease continues to evolve, with this technique becoming increasingly important in detection and characterization of lesions as well as in decisions about patient care. Specific designs and protocols for multidetector CT studies can be selected to minimize radiation dose to the patient. Principal clinical applications of 3D CT in evaluation of the pediatric musculoskeletal system include developmental abnormalities, trauma, neoplasms, and postoperative imaging.

  20. Diagnostic performance of multidetector computed tomography in distinguishing unilateral from bilateral abnormalities in primary hyperaldosteronism: comparison of multidetector computed tomography with adrenal vein sampling.

    PubMed

    Raman, Siva P; Lessne, Mark; Kawamoto, Satomi; Chen, Yifei; Salvatori, Roberto; Prescott, Jason D; Fishman, Elliot K

    2015-01-01

    The management of patients with primary hyperaldosteronism (PH) varies depending on whether the unregulated aldosterone secretion localizes to a single unilateral adrenal gland, traditionally determined using adrenal vein sampling (AVS). This study seeks to determine if the performance of multidetector computed tomography (MDCT) examinations performed using the latest scanner technology can reasonably match the results of AVS, and potentially avoid AVS in some patients. Computed tomographic scans in 56 patients with PH were independently reviewed by 2 radiologists for the presence of adrenal nodules and qualitative adrenal thickening. Results were correlated with AVS results. Of 35 patients with MDCT evidence of unilateral nodules, the imaging findings correctly predicted AVS localization in only 23 (65.7%) cases. When stratified by size, MDCT was accurate in only 71.4% of cases for nodules measuring 10 mm or less, and only 55.0% of cases for nodules measuring 11 to 20 mm. Of the 12 cases where MDCT did not correctly localize, AVS localized to the contralateral adrenal gland in 4 cases, whereas AVS suggested no lateralization in 8 cases. In patients with normal bilateral adrenal glands on MDCT, 2/7 (28.6%) of cases demonstrated unilateral localization on AVS, and in patients with bilateral adrenal nodules, only 3/14 (21.4%) did not demonstrate lateralization on AVS. Multidetector computed tomography, even when performed with the latest generation of MDCT scanners, does not offer sufficient diagnostic accuracy to replace AVS in patients with PH.

  1. Tc-99m-galactosyl-neoglycoalbumin (Tc-NGA) liver imaging: Potential application in liver transplantation

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Woodle, E.S.; Vera, D.R.; Ward, R.E.

    1984-01-01

    Tc-NGA is a hepatocyte receptor-specific imaging agent whose uptake by the liver has been shown to be dependent upon blood flow and receptor concentration. The combination of anatomic and physiologic information obtained with Tc-NGA may provide a new tool for studying hepatic function in liver transplant recipients. To evaluate the potential role of Tc-NGA in liver transplant recipients, studies were performed in four groups of pigs: controls (n=18); common bile duct (CBD) ligation (n=8); orthotopic liver transplant (n=9); and acute hepatic artery ligation (n=1). Serial studies performed in two animals with CBD ligation demonstrated normal imaging anatomy with minor changesmore » in the hepatic time-activity curves when compared to control studies. Studies in liver-transplanted animals showed significant changes in the hepatic time-activity curves during acute rejection and in preservation-related ischemic injury. Tc-NGA also demonstrated focal areas of hepatic infarction in a hepatic allograft within 24 hours of transplantation. The hepatic artery ligation study showed massive changes in the hepatic time-activity curve within two hours after ligation, with a diffuse decrease in hepatic activity. These results indicate that: (1) extrahepatic biliary tract obstruction causes only minor changes in Tc-NGA uptake; (2) Tc-NGA uptake by the liver is very sensitive to acute hepatic ischemia; (3) Tc-NGA may indicate the presence of preservation damage in the early postoperative period; and (4) Tc-NGA hepatic time-activity curves demonstrate significant changes during acute rejection.« less

  2. Olanzapine induced Q-Tc shortening.

    PubMed

    Shoja Shafti, Saeed; Fallah Jahromi, Parisa

    2014-12-01

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

  3. Intrathoracic Fat Measurements Using Multidetector Computed Tomography (MDCT): Feasibility and Reproducibility

    PubMed Central

    Stojanovska, Jadranka; Ibrahim, El-Sayed H.; Chughtai, Aamer R.; Jackson, Elizabeth A.; Gross, Barry H.; Jacobson, Jon A.; Tsodikov, Alexander; Daneshvar, Brian; Long, Benjamin D.; Chenevert, Thomas L.; Kazerooni, Ella A.

    2017-01-01

    Intrathoracic fat volume, more specifically, epicardial fat volume, is an emerging imaging biomarker of adverse cardiovascular events. The purpose of this work is to show the feasibility and reproducibility of intrathoracic fat volume measurement applied to contrast-enhanced multidetector computed tomography images. A retrospective cohort study of 62 subjects free of cardiovascular disease (55% females, age = 49 ± 11 years) conducted from 2008 to 2011 formed the study group. Intrathoracic fat volume was defined as all fat voxels measuring −50 to −250 Hounsfield Unit within the intrathoracic cavity from the level of the pulmonary artery bifurcation to the heart apex. The intrathoracic fat was separated into epicardial and extrapericardial fat by tracing the pericardium. The measurements were obtained by 2 readers and compared for interrater reproducibility. The fat volume measurements for the study group were 141 ± 72 cm3 for intrathoracic fat, 58 ± 27 cm3 for epicardial fat, and 84 ± 50 cm3 for extrapericardial fat. There was no statistically significant difference in intrathoracic fat volume measurements between the 2 readers, with correlation coefficients of 0.88 (P = .55) for intrathoracic fat volume and −0.12 (P = .33) for epicardial fat volume. Voxel-based measurement of intrathoracic fat, including the separation into epicardial and extrapericardial fat, is feasible and highly reproducible from multidetector computed tomography scans. PMID:28626797

  4. Inverse correlation between quasiparticle mass and Tc in a cuprate high-Tc superconductor

    PubMed Central

    Putzke, Carsten; Malone, Liam; Badoux, Sven; Vignolle, Baptiste; Vignolles, David; Tabis, Wojciech; Walmsley, Philip; Bird, Matthew; Hussey, Nigel E.; Proust, Cyril; Carrington, Antony

    2016-01-01

    Close to a zero-temperature transition between ordered and disordered electronic phases, quantum fluctuations can lead to a strong enhancement of electron mass and to the emergence of competing phases such as superconductivity. A correlation between the existence of such a quantum phase transition and superconductivity is quite well established in some heavy fermion and iron-based superconductors, and there have been suggestions that high-temperature superconductivity in copper-oxide materials (cuprates) may also be driven by the same mechanism. Close to optimal doping, where the superconducting transition temperature Tc is maximal in cuprates, two different phases are known to compete with superconductivity: a poorly understood pseudogap phase and a charge-ordered phase. Recent experiments have shown a strong increase in quasiparticle mass m* in the cuprate YBa2Cu3O7-δ as optimal doping is approached, suggesting that quantum fluctuations of the charge-ordered phase may be responsible for the high-Tc superconductivity. We have tested the robustness of this correlation between m* and Tc by performing quantum oscillation studies on the stoichiometric compound YBa2Cu4O8 under hydrostatic pressure. In contrast to the results for YBa2Cu3O7-δ, we find that in YBa2Cu4O8, the mass decreases as Tc increases under pressure. This inverse correlation between m* and Tc suggests that quantum fluctuations of the charge order enhance m* but do not enhance Tc. PMID:27034989

  5. Molecular and biochemical characterisation of two aspartic proteinases TcAP1 and TcAP2 from Theobroma cacao seeds.

    PubMed

    Laloi, Maryse; McCarthy, James; Morandi, Olivia; Gysler, Christof; Bucheli, Peter

    2002-09-01

    Aspartic proteinase (EC 3.4.23) activity plays a pivotal role in the degradation of Theobroma cacao L. seed proteins during the fermentation step of cacao bean processing. Therefore, this enzyme is believed to be critical for the formation of the peptide and amino acid cocoa flavor precursors that occurs during fermentation. Using cDNA cloning and northern blot analysis, we show here that there are at least two distinct aspartic proteinase genes ( TcAP1 and TcAP2) expressed during cacao seed development. Both genes are expressed early during seed development and their mRNA levels decrease towards the end of seed maturation. TcAP2 is expressed at a much higher level than TcAP1, although the expression of TcAP1 increases slightly during germination. The proteins encoded by TcAP1 and TcAP2 are relatively different from each other (73% identity). This, and the fact that the two corresponding genes have different expression patterns, suggests that the TcAP1 and TcAP2 proteins may have different functions in the maturing seeds and during germination. Because the TcAP2 gene is expressed at a much higher level during seed development than TcAP1, it is likely that the TcAP2 protein is primarily responsible for the majority of the industrially important protein hydrolysis that occurs during cacao bean fermentation. Finally, TcAP2 has been functionally expressed in the yeast Yarrowia lipolytica. The secreted recombinant protein is able to hydrolyse bovine haemoglobin at acidic pH and is sensitive to pepstatin A, confirming that TcAP2 encodes an aspartic proteinase, and strongly suggests that this gene encodes the well-characterized aspartic proteinase of mature cacao seeds.

  6. Effects of FlAsH/Tetracysteine (TC) tag on PrP proteolysis and PrPres formation by TC-scanning

    PubMed Central

    Taguchi, Yuzuru; Hohsfield, Lindsay A.; Hollister, Jason R.

    2014-01-01

    The FlAsH/tetracysteine (FlAsH/TC) tag is a powerful tool for fluorescent labeling of proteins. However, even small tags such as FlAsH/TC could alter the behavior of the tagged proteins, especially if the insertion occurs at internal sites. Defining the influence of FlAsH/TC on nearby protein-protein interactions might aid in selecting appropriate positions for internal TC insertions and allow the exploitation of serial FlAsH/TC insertions (TC-scanning) as a probe to characterize sites of protein-protein interaction. To explore this application in the context of substrate-protease interactions, we analyzed the effect of FlAsH/TC insertions on proteolysis of cellular prion protein (PrPsen) in in vitro reactions and generation of the C1 metabolic fragment of PrPsen in live neuroblastoma cells. The influence of FlAsH/TC insertion was evaluated by TC-scanning across the cleavage sites of each protease. The results showed that FlAsH/TC inhibited protease cleavage only within limited ranges of the cleavage sites that varied from about 1 to 6 residues-wide depending on the protease, providing an estimate of the PrP residues interacting with each protease. TC-scanning was also used to probe a different type of protein-protein interaction, the conformational conversion of FlAsH-PrPsen to the prion disease-associated isoform, PrPres. PrP constructs with FlAsH/TC insertions at residues 90–96 but not 97–101 were converted to FlAsH-PrPres, identifying a boundary separating loosely versus compactly folded regions of PrPres. Our observations demonstrate that TC-scanning with the FlAsH/TC tag can be a versatile method for probing protein-protein interactions and folding processes. PMID:23943295

  7. Telecom 2-B and 2-C (TC2B and TC2C)

    NASA Technical Reports Server (NTRS)

    Dulac, J.; Alvarez, H.

    1991-01-01

    The DSN (Deep Space Network) mission support requirements for Telecom 2-B and 2-C (TC2B and TC2C) are summarized. These Telecom missions will provide high-speed data link applications, telephone, and television service between France and overseas territories as a follow-on to TC2A. Mission objectives are outlined and the DSN support requirements are defined through the presentation of tables and narratives describing the spacecraft flight profile; DSN support coverage; frequency assignments; support parameters for telemetry, command and support systems; and tracking support responsibility.

  8. Trypanosoma cruzi diversity in the Gran Chaco: mixed infections and differential host distribution of TcV and TcVI.

    PubMed

    Monje-Rumi, María M; Brandán, Cecilia Pérez; Ragone, Paula G; Tomasini, Nicolás; Lauthier, Juan J; Alberti D'Amato, Anahí M; Cimino, Rubén O; Orellana, Viviana; Basombrío, Miguel A; Diosque, Patricio

    2015-01-01

    The transmission cycles of Trypanosoma cruzi in the Gran Chaco are complex networks involving domestic and wild components, whose interrelationships are not well understood. Knowing the circuit of transmission of the different Discrete Typing Units (DTUs) of T. cruzi in the complex environment of the Chaco region is relevant to understanding how the different components (reservoirs, vectors, ecotopes) interact. In the present study we identified the DTUs infecting humans and dogs in two rural areas of the Gran Chaco in Argentina, using molecular methods which avoid parasite culture. Blood samples of humans and dogs were typified by PCR-DNA blotting and hybridization assays with five specific DNA probes (TcI, TcII, TcIII, TcV and TcVI). PCR analyses were performed on seropositive human and dog samples and showed the presence of T. cruzi DNA in 41.7% (98/235) and 53% (35/66) samples, respectively. The identification of infective DTUs was determined in 83.6% (82/98) and 91.4% (32/35) in human and dog samples, respectively. Single infections (36.7% - 36/98) and a previously not detected high proportion of mixed infections (47.9% - 47/98) were found. In a 15.3% (15/98) of samples the infecting DTU was not identified. Among the single infections TcV was the most prevalent DTU (30.6% - 30/98) in human samples; while TcVI (42.8% - 15/35) showed the highest prevalence in dog samples. TcV/TcVI was the most prevalent mixed infection in humans (32.6% - 32/98); and TcI/TcVI (14.3% - 5/35) in dogs. Significant associations between TcV with humans and TcVI with dogs were detected. For the first time, the presence of TcIII was detected in humans from this region. The occurrence of one human infected whit TcIII (a principally wild DTU) could be suggested the emergence of this, in domestic cycles in the Gran Chaco. Copyright © 2014 Elsevier B.V. All rights reserved.

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

    PubMed

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

    2017-12-01

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

  10. Imaging of irradiated liver with Tc-99m-sulfur colloid and Tc-99m-IDA

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Gelfand, M.J.; Saha, S.; Aron, B.S.

    1981-09-01

    In three cases, irradiated regions of liver failed to concentrate Tc-99m-sulfur colloid. In two of these three, imaging with Tc-99m-acetanilide iminodiacetic acid (IDA) agents within five days showed near normal hepatic uptake of this hepatobiliary imaging agent. The hepatic parenchymal cells may be imaged with Tc-99m-IDA in some irradiated regions of liver, despite loss of reticuloendothelial cell function.

  11. Amyloidosis of heart and liver: comparison of Tc-99m pyrophosphate and Tc-99m methylene diphosphonate for detection

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Lee, V.W.; Caldarone, A.G.; Falk, R.H.

    1983-07-01

    A prospective, comparative study was made of the efficacy of technetium-99m pyrophosphate (Tc PYP) and technetium-99m methylene diphosphonate (Tc MDP) in detecting soft-tissue amyloidois. Tc PYP and Tc MDP scans were obtained within ten-day intervals in seven patients with histologically proven amyloidosis. Tc PYP was a better scanning agent for soft-tissue amyloidosis in all patients. Cardiac and hepatic involvement were proved by autopsy in one patient. Involvement of the heart was confirmed by echocardiography in five patients. The potential use of tc PYP scannning as a screening test for soft-tissue amyloidosis is discussed.

  12. Applicability of plasmid calibrant pTC1507 in quantification of TC1507 maize: an interlaboratory study.

    PubMed

    Meng, Yanan; Liu, Xin; Wang, Shu; Zhang, Dabing; Yang, Litao

    2012-01-11

    To enforce the labeling regulations of genetically modified organisms (GMOs), the application of DNA plasmids as calibrants is becoming essential for the practical quantification of GMOs. This study reports the construction of plasmid pTC1507 for a quantification assay of genetically modified (GM) maize TC1507 and the collaborative ring trial in international validation of its applicability as a plasmid calibrant. pTC1507 includes one event-specific sequence of TC1507 maize and one unique sequence of maize endogenous gene zSSIIb. A total of eight GMO detection laboratories worldwide were invited to join the validation process, and test results were returned from all eight participants. Statistical analysis of the returned results showed that real-time PCR assays using pTC1507 as calibrant in both GM event-specific and endogenous gene quantifications had high PCR efficiency (ranging from 0.80 to 1.15) and good linearity (ranging from 0.9921 to 0.9998). In a quantification assay of five blind samples, the bias between the test values and true values ranged from 2.6 to 24.9%. All results indicated that the developed pTC1507 plasmid is applicable for the quantitative analysis of TC1507 maize and can be used as a suitable substitute for dried powder certified reference materials (CRMs).

  13. Penetrating Colorectal Injuries: Diagnostic Performance of Multidetector CT with Trajectography.

    PubMed

    Dreizin, David; Boscak, Alexis R; Anstadt, Michael J; Tirada, Nikki; Chiu, William C; Munera, Felipe; Bodanapally, Uttam K; Hornick, Michael; Stein, Deborah M

    2016-12-01

    Purpose To determine the diagnostic performance of multidetector computed tomography (CT) with trajectography for penetrating colorectal injuries. Materials and Methods This institutional review board-approved and HIPAA-compliant study was a 6-year blinded retrospective review by two independent readers of 182 consecutive patients who preoperatively underwent 40- or 64-row multidetector CT for penetrating torso trauma below the diaphragm and had surgically confirmed findings. Colorectal perforation was present in 42 patients. Trajectory analysis with postprocessing software was used for all studies. Additional signs evaluated were rectal contrast agent leak, collections of extruded fecal material, mural defect, wall thickening, abnormal enhancement, free fluid or stranding, and free air. The quality of the colorectal contrast agent administration was recorded. Sensitivity, specificity, predictive values, areas under the receiver operating characteristic curves (AUCs), and Cohen κ were determined. Results In patients with rectal contrast agent administration (n = 151), AUCs were 0.90-0.91, which indicated excellent accuracy. Trajectory was sensitive (88%-91%). For single wounds (n = 104), sensitivity of trajectory was 96% for both readers, but was only 80% for multiple wounds (n = 47). Contrast agent leak was highly specific (96%-98%), but insensitive (42%-46%). Improved diagnostic performance was observed in patients with poor colonic distension or opacification. Accuracy remained high (AUC, 0.86-0.99) in the group without rectal contrast agent administration (n = 31). Conclusion Trajectory had excellent sensitivity, while rectal contrast agent leak was specific but insensitive. Sensitivity of trajectory was lower for multiple wounds. Accuracy remained high in patients without rectal contrast agent administration. © RSNA, 2016.

  14. Theoretical Modeling of (99)Tc NMR Chemical Shifts.

    PubMed

    Hall, Gabriel B; Andersen, Amity; Washton, Nancy M; Chatterjee, Sayandev; Levitskaia, Tatiana G

    2016-09-06

    Technetium-99 (Tc) displays a rich chemistry due to its wide range of accessible oxidation states (from -I to +VII) and ability to form coordination compounds. Determination of Tc speciation in complex mixtures is a major challenge, and (99)Tc nuclear magnetic resonance (NMR) spectroscopy is widely used to probe chemical environments of Tc in odd oxidation states. However, interpretation of (99)Tc NMR data is hindered by the lack of reference compounds. Density functional theory (DFT) calculations can help to fill this gap, but to date few computational studies have focused on (99)Tc NMR of compounds and complexes. This work evaluates the effectiveness of both pure generalized gradient approximation and their corresponding hybrid functionals, both with and without the inclusion of scalar relativistic effects, to model the (99)Tc NMR spectra of Tc(I) carbonyl compounds. With the exception of BLYP, which performed exceptionally well overall, hybrid functionals with inclusion of scalar relativistic effects are found to be necessary to accurately calculate (99)Tc NMR spectra. The computational method developed was used to tentatively assign an experimentally observed (99)Tc NMR peak at -1204 ppm to fac-Tc(CO)3(OH)3(2-). This study examines the effectiveness of DFT computations for interpretation of the (99)Tc NMR spectra of Tc(I) coordination compounds in high salt alkaline solutions.

  15. The Phosphatidylinositol 3-kinase Class III Complex Containing TcVps15 and TcVps34 Participates in Autophagy in Trypanosoma cruzi.

    PubMed

    Schoijet, Alejandra C; Sternlieb, Tamara; Alonso, Guillermo D

    2017-05-01

    Autophagy is a degradative process by which eukaryotic cells digest their own components to provide aminoacids that may function as energy source under nutritional stress conditions. There is experimental evidence for autophagy in parasitic protists belonging to the family Trypanosomatidae. However, few proteins implicated in this process have been characterized so far in these parasites. Moreover, it has been shown that autophagy is involved in Trypanosoma cruzi differentiation and thus might have a role in pathogenicity. Here, we report the cloning and biochemical characterization of TcVps15. In addition, we demonstrate that TcVps15 interact with the PI3K TcVps34 and that both proteins associate with cellular membranes. Under nutritional stress conditions, TcVps15 and TcVps34 modify their subcellular distribution showing a partial co-localization in autophagosomes with TcAtg8.1 and using an active site TcVps15-mutated version (TcVps15-K219D-HA) we demonstrated that this relocalization depends on the TcVps15 catalytic activity. Overexpression of TcVps15-HA and TcVps15-K219D-HA also leads to increased accumulation of monodansylcadaverine (MDC) in autophagic vacuoles under nutritional stress conditions compared to wild-type cells. In addition, the MDC-specific activity shows to be significantly higher in TcVps15-HA overexpressing cells when compared with TcVps15-K219D-HA. Our results reveal for the first time a role of TcVps15 as a key regulator of TcVps34 enzymatic activity and implicate the TcVps15-Vps34 complex in autophagy in T. cruzi, exposing a new key pathway to explore novel chemotherapeutic targets. © 2016 The Author(s) Journal of Eukaryotic Microbiology © 2016 International Society of Protistologists.

  16. In Vitro-Generated Tc17 Cells Present a Memory Phenotype and Serve As a Reservoir of Tc1 Cells In Vivo

    PubMed Central

    Flores-Santibáñez, Felipe; Cuadra, Bárbara; Fernández, Dominique; Rosemblatt, Mariana V.; Núñez, Sarah; Cruz, Pablo; Gálvez-Cancino, Felipe; Cárdenas, J. César; Lladser, Alvaro; Rosemblatt, Mario; Bono, María Rosa; Sauma, Daniela

    2018-01-01

    Memory CD8+ T cells are ideal candidates for cancer immunotherapy because they can mediate long-term protection against tumors. However, the therapeutic potential of different in vitro-generated CD8+ T cell effector subsets to persist and become memory cells has not been fully characterized. Type 1 CD8+ T (Tc1) cells produce interferon-γ and are endowed with high cytotoxic capacity, whereas IL-17-producing CD8+ T (Tc17) cells are less cytotoxic but display enhanced self-renewal capacity. We sought to evaluate the functional properties of in vitro-generated Tc17 cells and elucidate their potential to become long lasting memory cells. Our results show that in vitro-generated Tc17 cells display a greater in vivo persistence and expansion in response to secondary antigen stimulation compared to Tc1 cells. When transferred into recipient mice, Tc17 cells persist in secondary lymphoid organs, present a recirculation behavior consistent with central memory T cells, and can shift to a Tc1 phenotype. Accordingly, Tc17 cells are endowed with a higher mitochondrial spare respiratory capacity than Tc1 cells and express higher levels of memory-related molecules than Tc1 cells. Together, these results demonstrate that in vitro-generated Tc17 cells acquire a central memory program and provide a lasting reservoir of Tc1 cells in vivo, thus supporting the use of Tc17 lymphocytes in the design of novel and more effective therapies. PMID:29472932

  17. Diagnostic performance of 64-slice multidetector coronary computed tomographic angiography in women.

    PubMed

    Jug, Borut; Gupta, Mohit; Papazian, Jenny; Li, Dong; Tsang, Janet; Bhatia, Harpreet; Karlsberg, Ronald; Budoff, Matthew

    2012-12-01

    Diagnostic approach to chest pain in women is challenging, but still under-investigated. The purpose of this study was to assess the diagnostic performance of 64-slice multidetector coronary computed tomographic angiography (CCTA) in women with chest pain. We included 606 patients--255 women and 351 men (mean age 61 ± 12 years for both)--who had been referred for a CCTA and an invasive coronary angiography (diagnostic standard) because of chest pain, either as part of clinical work-up in two urban medical centers or as part of the multicenter ACCURACY trial. On a patient-based model, the sensitivity, specificity, and positive predictive value (PPV) and negative predictive value to detect ≥50% and ≥70% stenosis were 98%, 84%, 87%, and 97% and 96%, 83%, 77%, and 97%, respectively, for women and 97%, 83%, 89%, and 95% and 94%, 91%, 90%, and 94%, respectively, for men. There were no statistically significant differences between men and women in diagnostic performance measures except for the PPV of detecting a ≥70% stenosis (P = .007). In women with chest pain, 64-slice multidetector CCTA is at least as sensitive and specific as in men. Our findings suggest that CCTA is a promising diagnostic tool for timely detection and/or exclusion of CAD in symptomatic intermediate-risk female populations.

  18. Vertical distributions of (99)Tc and the (99)Tc/(137)Cs activity ratio in the coastal water off Aomori, Japan.

    PubMed

    Nakanishi, Takahiro; Zheng, Jian; Aono, Tatsuo; Yamada, Masatoshi; Kusakabe, Masashi

    2011-08-01

    Using a sector-field ICP-MS the vertical distributions of the (99)Tc concentration and (99)Tc/(137)Cs activity ratio were measured in the coastal waters off Aomori Prefecture, Japan, where a spent-nuclear-fuel reprocessing plant has begun test operation. The (99)Tc concentrations in surface water ranged from 1.8 to 2.4 mBq/m(3), no greater than the estimated background level. Relatively high (99)Tc/(137)Cs activity ratios (10-12 × 10(-4)) would be caused by the inflow of the high-(99)Tc/(137)Cs water mass from the Japan Sea. There is no observable contamination from the reprocessing plant in the investigated area. The (99)Tc concentration and the (99)Tc/(137)Cs activity ratio in water column showed gradual decreases with depth. Our results implied that (99)Tc behaves in a more conservative manner than (137)Cs in marine environments. Copyright © 2011 Elsevier Ltd. All rights reserved.

  19. Differential Activation of CD8+ Tumor-Specific Tc1 and Tc2 Cells by an IL-10-Producing Murine Plasmacytoma

    PubMed Central

    Pauels, Hans-Gerd; Becker, Christian; Kölsch, Eckehart

    1998-01-01

    The involvement of counteractive CD8+ T-cell subsets during tumor-specific immune responses was analyzed in a syngeneic murine plasmacytoma model. CD8+ Tc cells against the immunogenic IL-10-producing BALB/c plasmacytoma ADJ-PC-5 can be easily induced by immunization of BALB/c mice with X-irradiated ADJ-PC-5 tumor cells in vivo and in vitro. However, the failure of recipient mice to mount a protective Tc response against the tumor during early stages of a real or simulated tumor growth is not due to immunological ignorance, but depends on the induction of tumor-specific tolerance, involving a population of tumorinduced CD8+ T cells that are able to inhibit the generation of tumor-specific Tc cells in a primary ADJ-PC-5-specific MLTC, using IFN-γ as a suppressive factor. Whereas most longterm cultivated CD8+ ADJ-PC-5-specific Tc lines produce type-1 cytokines on stimulation, at least two of them, which were derived from a primary MLTC, display a type-2 cytokine spectrum. Furthermore, the primary in vitro Tc response against ADJ-PC-5 cells shows characteristics of a Tc2 response. The Tc response is strictly depending on tumor-derived IL-10. CD8+ Tc cells that are induced in a primary MLTC do not produce IFN-γ, and the tumor-specific Tc response is enhanced by IL-4 but suppressed by IFN-γ or IL-12. In contrast, ADJ-PC- 5-specific CD8+ Tc cells from immunized mice are IFN-γ producing Tc1 cells. Since the primary in vitro Tc response against the tumor is suppressed even by the smallest numbers of irradiated ADJ-PC-5-specific Tc1 cells via IFN-γ these Tc1 cells behave similar to the suppressive CD8+ T cells that are induced during early stages of ADJ-PC-5 tumorigenesis. PMID:9814607

  20. Multidetector Computer Tomography: Evaluation of Blunt Chest Trauma in Adults

    PubMed Central

    Matos, António P.; Mascarenhas, Vasco; Herédia, Vasco

    2014-01-01

    Imaging plays an essential part of chest trauma care. By definition, the employed imaging technique in the emergency setting should reach the correct diagnosis as fast as possible. In severe chest blunt trauma, multidetector computer tomography (MDCT) has become part of the initial workup, mainly due to its high sensitivity and diagnostic accuracy of the technique for the detection and characterization of thoracic injuries and also due to its wide availability in tertiary care centers. The aim of this paper is to review and illustrate a spectrum of characteristic MDCT findings of blunt traumatic injuries of the chest including the lungs, mediastinum, pleural space, and chest wall. PMID:25295188

  1. Multidetector computer tomography: evaluation of blunt chest trauma in adults.

    PubMed

    Palas, João; Matos, António P; Mascarenhas, Vasco; Herédia, Vasco; Ramalho, Miguel

    2014-01-01

    Imaging plays an essential part of chest trauma care. By definition, the employed imaging technique in the emergency setting should reach the correct diagnosis as fast as possible. In severe chest blunt trauma, multidetector computer tomography (MDCT) has become part of the initial workup, mainly due to its high sensitivity and diagnostic accuracy of the technique for the detection and characterization of thoracic injuries and also due to its wide availability in tertiary care centers. The aim of this paper is to review and illustrate a spectrum of characteristic MDCT findings of blunt traumatic injuries of the chest including the lungs, mediastinum, pleural space, and chest wall.

  2. Planificación Neuroquirúrgica con Software Osirix

    PubMed Central

    Jaimovich, Sebastián Gastón; Guevara, Martin; Pampin, Sergio; Jaimovich, Roberto; Gardella, Javier Luis

    2014-01-01

    Introducción: La individualidad anatómica es clave para reducir el trauma quirúrgico y obtener un mejor resultado. Actualmente, el avance en las neuroimágenes ha permitido objetivar esa individualidad anatómica, permitiendo planificar la intervención quirúrgica. Con este objetivo, presentamos nuestra experiencia con el software Osirix. Descripción de la técnica: Se presentan 3 casos ejemplificadores de 40 realizados. Caso 1: Paciente con meningioma de la convexidad parasagital izquierda en área premotora; Caso 2: Paciente con macroadenoma hipofisario, operada previamente por vía transeptoesfenoidal en otra institución con una resección parcial; Caso 3: Paciente con lesiones en pedúnculo cerebeloso medio bilateral. Se realizó la planificación prequirúrgica con el software OsiriX, fusionando y reconstruyendo en 3D las imágenes de TC e IRM, para analizar relaciones anatómicas, medir distancias, coordenadas y trayectorias, entre otras funciones. Discusión: El software OsiriX de acceso libre y gratuito permite al cirujano, mediante la fusión y reconstrucción en 3D de imágenes, analizar la anatomía individual del paciente y planificar de forma rápida, simple, segura y económica cirugías de alta complejidad. En el Caso 1 se pudo analizar las relaciones del tumor con las estructuras adyacentes para minimizar el abordaje. En el Caso 2 permitió comprender la anatomía post-operatoria previa del paciente, para determinar la trayectoria del abordaje transnasal endoscópico y la necesidad de ampliar su exposición, logrando la resección tumoral completa. En el Caso 3 permitió obtener las coordenadas estereotáxicas y trayectoria de una lesión sin representación tomográfica. Conclusión: En casos de no contar con costosos sistemas de neuronavegación o estereotáxia el software OsiriX es una alternativa a la hora de planificar la cirugía, con el objetivo de disminuir el trauma y la morbilidad operatoria. PMID:25165617

  3. Tc-99m tilmanocept versus Tc-99m sulfur colloid in breast cancer sentinel lymph node identification: Results from a randomized, blinded clinical trial.

    PubMed

    Unkart, Jonathan T; Hosseini, Ava; Wallace, Anne M

    2017-12-01

    No prior trials have compared sentinel lymph node (SLN) identification outcomes between Tc-99m tilmanocept (TcTM) and Tc-99m sulfur colloid (TcSC) in breast cancer (BC). We report on the secondary outcomes from a randomized, double-blinded, single surgeon clinical trial comparing post-injection site pain between TcTM and TcSC. Patients were randomized to receive a preoperative single, peritumoral intradermal injection of TcTM or TcSC. The number of total, "hot", and blue nodes detected and removed were compared between groups. Fifty-two (27-TcSC and 25-TcTM) patients were enrolled and underwent definitive surgical treatment. At least one "hot" SLN was detected in all patients. Three (5.8%) patients had a disease positive-SLN. The total number of SLNs removed was 61 (mean 2.26 (standard deviation (SD) 0.90)) in the TcSC group and 54 (mean 2.16 (SD 0.90)) in the TcTM group, P = 0.69. The total number of "hot" nodes in the TcSC group was 1.96 (SD 0.76) compared to 2.04 (SD 0.73) in the TcTM group, P = 0.71. The number of identified SLNs did not differ significantly between TcTM and TcSC. Given that no significant technical advantages exist between the two agents, surgeons should choose a radiopharmaceutical based on cost and side effect profile. © 2017 Wiley Periodicals, Inc.

  4. Imaging experimental intraabdominal abscesses with 99mTc-PEG liposomes and 99mTc-HYNIC IgG.

    PubMed Central

    Dams, E T; Reijnen, M M; Oyen, W J; Boerman, O C; Laverman, P; Storm, G; van der Meer, J W; Corstens, F H; van Goor, H

    1999-01-01

    OBJECTIVE: To evaluate the accuracy of technetium-99m-labeled polyethylene glycol-coated liposomes (99mTc-PEG liposomes) and technetium-99m-labeled nonspecific human immunoglobulin G (99mTc-HYNIC IgG) for the scintigraphic detection of experimental intraabdominal abscesses in comparison with that of a standard agent, gallium-67 citrate. BACKGROUND: Scintigraphic imaging techniques can be very useful for the rapid and accurate localization of intraabdominal abscesses. Two newly developed radiolabeled agents, 99mTc-PEG liposomes and 99mTc-HYNIC IgG, have shown to be excellent agents for imaging experimental focal infection, but have not yet been studied in the detection of abdominal abscesses. METHODS: Intraabdominal abscesses were induced in 42 rats using the cecal ligation and puncture technique. Seven days later, randomized groups of rats received 99mTc-PEG liposomes, 99mTc-HYNIC IgG, or 67Ga citrate intravenously. The rats were imaged up to 24 hours after the injection. The biodistribution of the radiolabel was determined by counting dissected tissues ex vivo. Macroscopic intraabdominal abnormalities and focal uptake on the images were independently scored on a semiquantitative scale. RESULTS: 99mTc-PEG liposomes provided the earliest scintigraphic visualization of the abscess (as soon as 2 hours after the injection vs. 4 hours for the other two agents). Liposomes, IgG, and gallium all showed similarly high absolute uptake in the abscess. Focal uptake of liposomes and gallium correlated best with the extent of the macroscopic abnormalities. CONCLUSIONS: 99mTc-PEG liposomes and 99mTc-HYNIC IgG performed at least as well as the standard agent, 67Ga citrate, in the detection of experimental intraabdominal abscesses, with obvious advantages such as lower radiation exposure and more favorable physical properties. Of the two technetium agents, the liposomes seemed to be superior, providing the earliest diagnostic image and the best correlation with the inflammatory

  5. [The role of multidetector computer tomography in diagnosis of acute pancreatitis].

    PubMed

    Lohanikhina, K Iu; Hordiienko, K P; Kozarenko, T M

    2014-10-01

    With the objective to improve the diagnostic semiotics of an acute pancreatitis (AP) 35 patients were examined, using 64-cut computeric tomograph Lightspeed VCT (GE, USA) with intravenous augmentation in arterial and portal phases. Basing on analysis of the investigations conducted, using multidetector computeric tomography (MDCT), the AP semiotics was systematized, which is characteristic for oedematous and destructive forms, diagnosed in 19 (44.2%) and 16 (45.8%) patients, accordingly. The procedure for estimation of preservation of the organ functional capacity in pancreonecrosis pres- ence was elaborated, promoting rising of the method diagnostic efficacy by 5.3 - 9.4%.

  6. Differential Lung Uptake of 99mTc-HMPAO and 99mTc-Duramycin in the Chronic Hyperoxia Rat Model

    PubMed Central

    Clough, Anne V.; Audi, Said H.; Haworth, Steven T.; Roerig, David L.

    2015-01-01

    Noninvasive radionuclide imaging has the potential to identify and assess mechanisms involved in particular stages of lung injury which occur with acute respiratory distress syndrome, for example. Lung uptake of 99mTc-hexamethylpropyleneamine oxime (HMPAO) is reported to be partially dependent on the redox status of the lung tissue while 99mTc-duramycin, a new marker of cell injury, senses cell death via apoptosis and/or necrosis. Thus, we investigated changes in lung uptake of these agents in rat exposed to hyperoxia for prolonged periods, a common model of acute lung injury. Methods Male Sprague-Dawley rats were pre-exposed to either normoxia (21% O2) or hyperoxia (85% O2) for up to 21 days. For imaging, the rats were anesthetized, injected i.v. with either 99mTc-HMPAO or 99mTc-duramycin (37-74 MBq) and planar images were acquired using a high sensitivity modular gamma camera. Subsequently, 99mTc-macroagreggated albumin (37 MBq, diam=10-40 μm) was injected i.v., imaged, and used to define a lung region-of-interest. The lung to background ratio was used as a measure of lung uptake. Results Hyperoxia exposure resulted in a 74% increase in 99mTc-HMPAO lung uptake, which peaked at 7 days and persisted for the 21 days of exposure. 99mTc-duramycin lung uptake was also maximal at 7 days of exposure but decreased to near control levels by 21 days. The sustained elevation of 99mTc-HMPAO uptake suggests ongoing changes in lung redox status whereas cell death appears to have subsided by 21 days. Conclusion These results suggest the potential use of 99mTc-HMPAO and 99mTc-duramycin as redox and cell-death imaging biomarkers, respectively, for in vivo identification and assessment of different stages of lung injury. PMID:23086010

  7. Theoretical Modeling of 99 Tc NMR Chemical Shifts

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Hall, Gabriel B.; Andersen, Amity; Washton, Nancy M.

    Technetium (Tc) displays a rich chemistry due to the wide range of oxidation states (from -I to +VII) and ability to form coordination compounds. Determination of Tc speciation in complex mixtures is a major challenge, and 99Tc NMR spec-troscopy is widely used to probe chemical environments of Tc in odd oxidation states. However interpretation of the 99Tc NMR data is hindered by the lack of reference compounds. DFT computations can help fill this gap, but to date few com-putational studies have focused on 99Tc NMR of compounds and complexes. This work systematically evaluates the inclu-sion small percentages of Hartree-Fock exchangemore » correlation and relativistic effects in DFT computations to support in-terpretation of the 99Tc NMR spectra. Hybrid functionals are found to perform better than their pure GGA counterparts, and non-relativistic calculations have been found to generally show a lower mean absolute deviation from experiment. Overall non-relativistic PBE0 and B3PW91 calculations are found to most accurately predict 99Tc NMR chemical shifts.« less

  8. Mental Health and the TC. Chapter 5.

    ERIC Educational Resources Information Center

    Acampora, Alfonso P., Ed.; Nebelkopf, Ethan, Ed.

    This document contains 19 papers from the ninth World Conference of Therapeutic Communities (TCs) that deal with the interface between the mental health establishments and the TC. Papers include: (1) "Psychiatry and the TC" (Jerome Jaffe); (2) "The Chemical Brain" (Sidney Cohen); (3) "Where Does the TC Fail?" (Ab…

  9. Pulmonary arterial hypertension in children: diagnosis using ratio of main pulmonary artery to ascending aorta diameter as determined by multi-detector computed tomography.

    PubMed

    Caro-Domínguez, Pablo; Compton, Gregory; Humpl, Tilman; Manson, David E

    2016-09-01

    The ratio of the transverse diameter of the main pulmonary artery (MPA) to ascending aorta as determined at multi-detector CT is a tool that can be used to assess the pulmonary arterial size in cases of pulmonary arterial hypertension in children. To establish a ratio of MPA to ascending aorta diameter using multi-detector CT imaging suggestive of pulmonary arterial hypertension in children. We hypothesize that a defined ratio of MPA to ascending aorta is identifiable on multi-detector CT and that higher ratios can be used to reliably diagnose the presence of pulmonary arterial hypertension in children. We calculated the multi-detector CT ratio of MPA to ascending aorta diameter in 44 children with documented pulmonary arterial hypertension by right heart catheterization and in 44 age- and gender-matched control children with no predisposing factors for pulmonary arterial hypertension. We compared this multi-detector-CT-determined ratio with the MPA pressure in the study group, as well as with the ratio of MPA to ascending aorta in the control group. A threshold ratio value was calculated to accurately identify children with pulmonary arterial hypertension. Children with documented primary pulmonary arterial hypertension have a significantly higher ratio of MPA to ascending aorta (1.46) than children without pulmonary arterial hypertension (1.11). A ratio of 1.3 carries a positive likelihood of 34 and a positive predictive value of 97% for the diagnosis of pulmonary arterial hypertension. The pulmonary arteries were larger in children with pulmonary arterial hypertension than in a control group of normal children. A CT-measured ratio of MPA to ascending aorta of 1.3 should raise the suspicion of pulmonary arterial hypertension in children.

  10. Multi-detector system approach for unattended uranium enrichment monitoring at gas centrifuge enrichment plants

    NASA Astrophysics Data System (ADS)

    Favalli, A.; Lombardi, M.; MacArthur, D. W.; McCluskey, C.; Moss, C. E.; Paffett, M. T.; Ianakiev, K. D.

    2018-01-01

    Improving the quality of safeguards measurements at Gas Centrifuge Enrichment Plants while reducing the inspection effort is an important objective given the number of existing and new plants that need to be safeguarded. A useful tool in many safeguards approaches is the on-line monitoring of enrichment in process pipes. One requirement of such a monitor is a simple, reliable and precise passive measurement of the 186-keV line from 235U. The other information required is the amount of gas in the pipe, which can be obtained by a transmission or pressure measurement. We describe our research to develop such a passive measurement system. Unfortunately, a complication arises in the interpretation of the gamma measurements, from the contribution of uranium deposits on the wall of the pipe to the 186-keV peak. A multi-detector approach to address this complication is presented where two measurements, one with signal primarily from gas and one with signal primarily from deposits, are performed simultaneously with different detectors and geometries. This allows a correction to be made to the 186-keV peak for the contribution from the deposit. We present the design of the multi-detector system and the results of the experimental calibration of the proof-of-principle prototype built at LANL.

  11. [The different manifestations of pulmonary aspergillosis: multidetector computed tomography findings].

    PubMed

    Koren Fernández, L; Alonso Charterina, S; Alcalá-Galiano Rubio, A; Sánchez Nistal, M A

    2014-01-01

    Pulmonary aspergillosis is a fungal infection usually caused by inhaling Aspergillus fumigatus spores. However, when we talk about aspergillosis, we normally refer to the spectrum of clinical and radiological findings that depend directly on the patient's immune status, on the prior existence of lung disease, and on the virulence of the infective organism. There are four types of pulmonary aspergillosis (aspergilloma, allergic bronchopulmonary aspergillosis, chronic necrotizing pulmonary aspergillosis, and invasive aspergillosis), and each type has its own distinct radiologic findings. We review the signs of pulmonary aspergillosis on multidetector computed tomography and we correlate them with patients' symptoms and immune responses. Likewise, we discuss the differential diagnoses. Copyright © 2013 SERAM. Published by Elsevier Espana. All rights reserved.

  12. Pressure and high-Tc superconductivity in sulfur hydrides.

    PubMed

    Gor'kov, Lev P; Kresin, Vladimir Z

    2016-05-11

    The paper discusses fundamentals of record-TC superconductivity discovered under high pressure in sulfur hydride. The rapid increase of TC with pressure in the vicinity of Pcr ≈ 123GPa is interpreted as the fingerprint of a first-order structural transition. Based on the cubic symmetry of the high-TC phase, it is argued that the lower-TC phase has a different periodicity, possibly related to an instability with a commensurate structural vector. In addition to the acoustic branches, the phonon spectrum of H3S contains hydrogen modes with much higher frequencies. Because of the complex spectrum, usual methods of calculating TC are here inapplicable. A modified approach is formulated and shown to provide realistic values for TC and to determine the relative contributions of optical and acoustic branches. The isotope effect (change of TC upon Deuterium for Hydrogen substitution) originates from high frequency phonons and differs in the two phases. The decrease of TC following its maximum in the high-TC phase is a sign of intermixing with pairing at hole-like pockets which arise in the energy spectrum of the cubic phase at the structural transition. On-pockets pairing leads to the appearance of a second gap and is remarkable for its non-adiabatic regime: hydrogen mode frequencies are comparable to the Fermi energy.

  13. Impeding 99Tc(IV) mobility in novel waste forms

    DOE PAGES

    Lee, Mal-Soon; Um, Wooyong; Wang, Guohui; ...

    2016-06-30

    Technetium ( 99Tc) is a long-lived radioactive fission product whose mobility in the subsurface is largely governed by its oxidation state1. Immobilization of Tc in mineral substrates is crucial for radioactive waste management and environmental remediation. Tc(IV) incorporation in spinels2, 3 has been proposed as a novel method to increase Tc retention in glass waste forms. However, experiments with Tc-magnetite under high temperature and oxic conditions showed re-oxidation of Tc(IV) to volatile pertechnetate Tc(VII)O4-.4, 5 Here we address this problem with large-scale ab initio molecular dynamics simulations and propose that elevated temperatures, 1st row transition metal dopants can significantly enhancemore » Tc retention in the order Co > Zn > Ni. Experiments with doped spinels at T=700 ºC provided quantitative confirmation of increased Tc retention in the same order predicted by theory. This work highlights the power of modern state-of-the-art simulations to provide essential insights and generate bottom-up design criteria of complex oxide materials at elevated temperatures.« less

  14. Patent foramen ovale: diagnosis with multidetector CT--comparison with transesophageal echocardiography.

    PubMed

    Kim, Young Jin; Hur, Jin; Shim, Chi-Young; Lee, Hye-Jeong; Ha, Jong-Won; Choe, Kyu Ok; Heo, Ji Hoe; Choi, Eui-Young; Choi, Byoung Wook

    2009-01-01

    To evaluate the clinical feasibility and accuracy of 64-section multidetector computed tomography (CT) compared with transesophageal echocardiography (TEE) for diagnosis of a patent foramen ovale (PFO). Institutional review board approval was obtained for this retrospective study. The study included 152 consecutive stroke patients (mean age, 61.7 years; 98 men, 54 women) who underwent both cardiac multidetector CT and TEE. Electrocardiographically gated cardiac CT was performed with a 64-section CT scanner by using a saline-chaser contrast agent injection technique. A contrast agent jet from the contrast agent-filled left atrium (LA) to the saline-filled right atrium (RA) and channel-like appearance of the interatrial septum (IAS) were evaluated on axial and oblique sagittal CT images. Two-dimensional and Doppler TEE were performed to detect PFO. The sensitivity, specificity, positive predictive value (PPV), and negative predictive value (NPV) of CT were obtained with TEE as the reference standard. A PFO was present in 26 patients at TEE. On CT images, a left-to-right contrast agent jet toward the inferior vena cava was noted in 21 patients (sensitivity, 73.1%; specificity, 98.4%; PPV, 90.5%; NPV, 94.7%). Channel-like appearance of the IAS was detected in 38 patients (sensitivity, 76.9%; specificity, 85.7%; PPV, 52.6%; NPV, 94.7%). Channel-like appearance of the IAS was noted in all patients who had a contrast agent jet. A contrast agent jet from LA to RA toward the inferior vena cava with channel-like appearance of the IAS on CT images confirms the presence of a PFO. (c) RSNA, 2008.

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

    PubMed

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

    2008-07-01

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

  16. 99mTc-3P4-RGD2 Scintimammography in the Assessment of Breast Lesions: Comparative Study with 99mTc-MIBI

    PubMed Central

    Gao, Shi; Ji, Tiefeng; Wen, Qiang; Song, Yan; Zhu, Lei; Xu, Zheli; Liu, Lin

    2014-01-01

    Purpose To compare the potential application of 99mTc-3P-Arg-Gly-Asp (99mTc-3P4-RGD2) scintimammography (SMM) and 99mTc-methoxyisobutylisonitrile (99mTc-MIBI) SMM for the differentiation of malignant from benign breast lesions. Method Thirty-six patients with breast masses on physical examination and/or suspicious mammography results that required fine needle aspiration cytology biopsy (FNAB) were included in the study. 99mTc-3P4-RGD2 and 99mTc-MIBI SMM were performed with single photon emission computed tomography (SPECT) at 60 min and 20 min respectively after intravenous injection of 738±86 MBq radiotracers on a separate day. Images were evaluated by the tumor to non-tumor localization ratios (T/NT). Receiver operating characteristic (ROC) curve analysis was performed on each radiotracer to calculate the cut-off values of quantitative indices and to compare the diagnostic performance for the ability to differentiate malignant from benign diseases. Results The mean T/NT ratio of 99mTc-3P4-RGD2 in malignant lesions was significantly higher than that in benign lesions (3.54±1.51 vs. 1.83±0.98, p<0.001). The sensitivity, specificity, and accuracy of 99mTc-3P4-RGD2 SMM were 89.3%, 90.9% and 89.7%, respectively, with a T/NT cut-off value of 2.40. The mean T/NT ratio of 99mTc-MIBI in malignant lesions was also significantly higher than that in benign lesions (2.86±0.99 vs. 1.51±0.61, p<0.001). The sensitivity, specificity and accuracy of 99mTc-MIBI SMM were 87.5%, 72.7% and 82.1%, respectively, with a T/NT cut-off value of 1.45. According to the ROC analysis, the area under the curve for 99mTc-3P4-RGD2 SMM (area = 0.851) was higher than that for 99mTc-MIBI SMM (area = 0.781), but the statistical difference was not significant. Conclusion 99mTc-3P4-RGD2 SMM does not provide any significant advantage over the established 99mTc-MIBI SMM for the detection of primary breast cancer. The T/NT ratio of 99mTc-3P4-RGD2 SMM was significantly higher than that of 99mTc

  17. Analysis of accumulation of 99mTc-octreotide and 99mTc-EDDA/HYNIC-Tyr3-octreotide in the rat kidneys.

    PubMed

    Kopecky, Martin; Semecky, Vladimir; Trejtnar, Frantisek; Laznicek, Milan; Laznickova, Alice; Nachtigal, Petr; Decristoforo, Clemens; Mather, Stephen J; Mäcke, Helmut R

    2004-02-01

    The aim of this study was to compare renal handling and distribution of (99m)Tc-octreotide and (99m)Tc-EDDA/HYNIC-Tyr(3)-octreotide (HYNIC-TOC) in rats. In kidney perfusion experiments, the renal clearance value of (99m)Tc-octreotide was three times lower than that of (99m)Tc-EDDA/HYNIC-TOC. The predominant renal excretion of (99m)Tc-EDDA/HYNIC-TOC was associated with a high and long-term renal accumulation up to 48 hrs. Microautoradiographic results indicated that (99m)Tc-EDDA/HYNIC-TOC was retained mainly in the renal medulla within the cells of the collecting ducts and in the surrounding tissue. Lower positivity was found in the proximal and distal tubular cells. We conclude that the mechanism of renal accumulation of somatostatin analogues renal accumulation is complex and that proximal tubular reabsorption is probably not the main mechanism for uptake of (99m)Tc-EDDA/HYNIC-TOC in the kidneys. The presence of the somatostatin receptors, differences in the tonicity level within kidneys and other possible mechanisms could participate in their renal accumulation.

  18. Novel 99mTc(III)-azide complexes [99mTc(N3)(CDO)(CDOH)2B-R] (CDOH2=cyclohexanedione dioxime) as potential radiotracers for heart imaging.

    PubMed

    Liu, Min; Zheng, Yumin; Avcibasi, Ugur; Liu, Shuang

    2016-11-01

    In this study, novel 99m Tc(III)-azide complexes [ 99m Tc(N 3 )(CDO)(CDOH) 2 B-R] ( 99m Tc-ISboroxime-N 3 : R=IS; 99m Tc-MPboroxime-N 3 : R=MP; 99m Tc-PAboroxime-N 3 : R=PA; 99m Tc-PYboroxime-N 3 : R=PY; and 99m Tc-Uboroxime-N 3 : R=5U) were evaluated as heart imaging agents. Complexes [ 99m Tc(N 3 )(CDO)(CDOH) 2 B-R] (R=IS, MP, PA, PY and 5U) were prepared by ligand exchange between NaN 3 and [ 99m TcCl(CDO)(CDOH) 2 B-R]. Biodistribution and imaging studies were carried out in Sprague-Dawley rats. Image quantification was performed to compare their initial heart uptake and myocardial retention. 99m Tc-ISboroxime-N 3 , 99m Tc-PYboroxime-N 3 and 99m Tc-Uboroxime-N 3 were prepared with high RCP (93-98%) while the RCP of 99m Tc-MPboroxime-N 3 and 99m Tc-PAboroxime-N 3 was 80-85%. The myocardial retention curves of 99m Tc-ISboroxime-N 3 , 99m Tc-PYboroxime-N 3 and 99m Tc-Uboroxime-N 3 were best fitted to the bi-exponential decay function. The half-time of the fast component was 1.6±0.4min for 99m Tc-ISboroxime-N 3 , 0.7±0.1min for 99m Tc-PYboroxime-N 3 and 0.9±0.4min for 99m Tc-Uboroxime-N 3 . The 2-min heart uptake from biodistribution studies followed the ranking order of 99m Tc-ISboroxime-N 3 (3.60±0.68%ID/g)> 99m Tc-PYboroxime-N 3 (2.35±0.37%ID/g)≫ 99m Tc-Uboroxime-N 3 (1.29±0.06%ID/g). 99m Tc-ISboroxime-N 3 had the highest 2-min heart uptake among 99m Tc radiotracers revaluated in SD rats. High quality SPECT images were obtained with the right and left ventricular walls being clearly delineated. The best image acquisition window was 0-5min for 99m Tc-ISboroxime-N 3 . Both azide coligand and boronate caps had significant impact on the heart uptake and myocardial retention of complexes [ 99m Tc(N 3 )(CDO)(CDOH) 2 B-R]. Among the radiotracers evaluated in SD rats, 99m Tc-ISboroxime-N 3 has the highest initial heart uptake with the heart retention comparable to that of 99m Tc-Teboroxime. 99m Tc-ISboroxime-N 3 is a promising alternative to 99m Tc-Teboroxime for

  19. Multidetector computed tomography diagnosis of gastric volvulus through the foramen of Morgagni.

    PubMed

    Lecouvet, S; Coulier, B; Pierard, F; Gogoase, M; Coppens, J P; Van Hoof, M

    2014-01-01

    Morgagni hernia is considered to be the rarest form of all diaphragmatic hernias. It develops through a congenital defect in the retrosternal area. Usually asymptomatic, this entity can lead to life-threatening complications such as incarceration, strangulation or volvulus of the herniated viscus. We hereby report a rare case of organoaxial gastric volvulus producing through the foramen of Morgagni in a 78-year-old woman. The full diagnosis was made by upper gastro-intestinal series and multidetector computed tomography (MDCT). The basic anatomy, physiopathology, diagnostic methods, complications and surgical treatment of Morgagni hernia are briefly reviewed.

  20. Multi-detector CT imaging in the postoperative orthopedic patient with metal hardware.

    PubMed

    Vande Berg, Bruno; Malghem, Jacques; Maldague, Baudouin; Lecouvet, Frederic

    2006-12-01

    Multi-detector CT imaging (MDCT) becomes routine imaging modality in the assessment of the postoperative orthopedic patients with metallic instrumentation that degrades image quality at MR imaging. This article reviews the physical basis and CT appearance of such metal-related artifacts. It also addresses the clinical value of MDCT in postoperative orthopedic patients with emphasis on fracture healing, spinal fusion or arthrodesis, and joint replacement. MDCT imaging shows limitations in the assessment of the bone marrow cavity and of the soft tissues for which MR imaging remains the imaging modality of choice despite metal-related anatomic distortions and signal alteration.

  1. Measurement of positron annihilation lifetimes for positron burst by multi-detector array

    NASA Astrophysics Data System (ADS)

    Wang, B. Y.; Kuang, P.; Liu, F. Y.; Han, Z. J.; Cao, X. Z.; Zhang, P.

    2018-03-01

    It is currently impossible to exploit the timing information in a gamma-ray pulse generated within nanoseconds when a high-intensity positron burst annihilation event occurs in a target using conventional single-detector methods. A state-of-the-art solution to the problem is proposed in this paper. In this approach, a multi-detector array composed of many independent detection cells mounted spherically around the target is designed to detect the time distribution of the annihilated gamma rays generated following, in particular, a positron burst emitting huge amounts of positrons in a short pulse duration, even less than a few nano- or picoseconds.

  2. Association between diabetes and different components of coronary atherosclerotic plaque burden as measured by coronary multidetector computed tomography.

    PubMed

    Yun, Chun-Ho; Schlett, Christopher L; Rogers, Ian S; Truong, Quynh A; Toepker, Michael; Donnelly, Patrick; Brady, Thomas J; Hoffmann, Udo; Bamberg, Fabian

    2009-08-01

    The aim of the study was to assess differences in the presence, extent, and composition of coronary atherosclerotic plaque burden as detected by coronary multidetector computed tomography (MDCT) between patients with and without diabetes mellitus. We compared coronary atherosclerotic plaques (any plaque, calcified [CAP], non-calcified [NCAP, and mixed plaque [MCAP

  3. The Tribolium chitin synthase genes TcCHS1 and TcCHS2 are specialized for synthesis of epidermal cuticle and midgut peritrophic matrix.

    PubMed

    Arakane, Y; Muthukrishnan, S; Kramer, K J; Specht, C A; Tomoyasu, Y; Lorenzen, M D; Kanost, M; Beeman, R W

    2005-10-01

    Functional analysis of the two chitin synthase genes, TcCHS1 and TcCHS2, in the red flour beetle, Tribolium castaneum, revealed unique and complementary roles for each gene. TcCHS1-specific RNA interference (RNAi) disrupted all three types of moult (larval-larval, larval-pupal and pupal-adult) and greatly reduced whole-body chitin content. Exon-specific RNAi showed that splice variant 8a of TcCHS1 was required for both the larval-pupal and pupal-adult moults, whereas splice variant 8b was required only for the latter. TcCHS2-specific RNAi had no effect on metamorphosis or on total body chitin content. However, RNAi-mediated down-regulation of TcCHS2, but not TcCHS1, led to cessation of feeding, a dramatic shrinkage in larval size and reduced chitin content in the midgut.

  4. Multi-detector system approach for unattended uranium enrichment monitoring at gas centrifuge enrichment plants

    DOE PAGES

    Favalli, A.; Lombardi, M.; MacArthur, D. W.; ...

    2017-09-14

    Improving the quality of safeguards measurements at Gas Centrifuge Enrichment Plants while reducing the inspection effort is an important objective given the number of existing and new plants that need to be safeguarded. A useful tool in many safeguards approaches is the on-line monitoring of enrichment in process pipes. One requirement of such a monitor is a simple, reliable and precise passive measurement of the 186-keV line from 235U. The other information required is the amount of gas in the pipe, which can be obtained by a transmission or pressure measurement. Here, we describe our research to develop such amore » passive measurement system. Unfortunately, a complication arises in the interpretation of the gamma measurements, from the contribution of uranium deposits on the wall of the pipe to the 186-keV peak. A multi-detector approach to address this complication is presented where two measurements, one with signal primarily from gas and one with signal primarily from deposits, are performed simultaneously with different detectors and geometries. This allows a correction to be made to the 186-keV peak for the contribution from the deposit. Finally, we present the design of the multi-detector system and the results of the experimental calibration of the proof-of-principle prototype built at LANL.« less

  5. Multi-detector system approach for unattended uranium enrichment monitoring at gas centrifuge enrichment plants

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Favalli, A.; Lombardi, M.; MacArthur, D. W.

    Improving the quality of safeguards measurements at Gas Centrifuge Enrichment Plants while reducing the inspection effort is an important objective given the number of existing and new plants that need to be safeguarded. A useful tool in many safeguards approaches is the on-line monitoring of enrichment in process pipes. One requirement of such a monitor is a simple, reliable and precise passive measurement of the 186-keV line from 235U. The other information required is the amount of gas in the pipe, which can be obtained by a transmission or pressure measurement. Here, we describe our research to develop such amore » passive measurement system. Unfortunately, a complication arises in the interpretation of the gamma measurements, from the contribution of uranium deposits on the wall of the pipe to the 186-keV peak. A multi-detector approach to address this complication is presented where two measurements, one with signal primarily from gas and one with signal primarily from deposits, are performed simultaneously with different detectors and geometries. This allows a correction to be made to the 186-keV peak for the contribution from the deposit. Finally, we present the design of the multi-detector system and the results of the experimental calibration of the proof-of-principle prototype built at LANL.« less

  6. Assessment of the direct cyclotron production of (99m)Tc: An approach to crisis management of (99m)Tc shortage.

    PubMed

    Rovais, Mohammad Reza Aboudzadeh; Aardaneh, Khosro; Aslani, Gholamreza; Rahiminejad, Ali; Yousefi, Kamran; Boulouri, Fatemeh

    2016-06-01

    Nowadays, the cyclotron production of technetium-99m ((99m)Tc) has been increased, due to the worldwide (99m)Tc generator shortage. In the present work, an improved strategy for the production of (99m)Tc, using the proton irradiation of the enriched (100)Mo was developed. The performance of this method in terms of the production yield, chemical purity, radiochemical purity, as well as radionuclide purity was evaluated. The average production yield was measured to be 356MBqμA(-1)h(-1). A good agreement was found between the calculated production yield and the experimental one. The radiochemical separation and total recovery yields of (99m)Tc were 92% and 69%, respectively. The radiochemical and the radionuclide purities of the (99m)Tc were 99% and >99.99% at the end of purification, respectively. The results of quality control tests (QC) support the concept that cyclotron-produced (99m)Tc is suitable for preparation of USP-compliant. Copyright © 2016 Elsevier Ltd. All rights reserved.

  7. Measuring functioning hepatocytes using Tc-99m galactosylneoglycoalbumin (Tc-NGA)

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Stadalnik, R.C.; Vera, D.R.; Quadro, R.E.

    1984-01-01

    Tc-NGA is a synthetic ligand which binds only to hepatic binding protein (HBP), a receptor found only in the liver. It exhibits the properties of high tissue specificity, affinity-dependent uptake, and dose-dependent uptake. Tc-NGA provides an opportunity to study the functioning hepatocyte. The authors evaluated the usefulness of this technique in patients with hepatitis and hepatoma. After intravenous administration of 5 mCi Tc-NGA, dynamic images were acquired for 30 minutes followed by static views. Estimates of HBP concentrations were obtained by kinetic analysis of blood and liver time-activity curves. Kinetic estimates (reduced chi-squares < 3.0) of HBP correlated well withmore » the clinical course and histology. For example, a patient with hepatoma whose calculated receptor population (functioning hepatocytes) was 3.0 +- 0.9 x 10/sup -7/ mole, which is the normal range, is doing well undergoing chemotherapy. Liver biopsy demonstrated normal liver tissue except for the hepatoma. Another patient with hepatoma who had a severely depressed receptor population, 1.2 +- 0.2 x 10/sup -8/ mole, expired one week after the study. Liver biopsy demonstrated practically no normal tissue. Thus, by means of a complementary, receptor radiopharmaceutical and mathematical model, one should be able to quantitatively follow hepatocyte function and predict response to a therapeutic regimen.« less

  8. Discordant hepatic uptake between Tc-99m sulfur colloid and Tc-99m DISIDA in hypervitaminosis A

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Vincent, L.M.; McCartney, W.H.; Mauro, M.A.

    1984-02-01

    Scintigraphic findings in a patient with biopsy-proven hypervitaminosis A included markedly impaired hepatic uptake of Tc-99m sulfur colloid but essentially normal uptake of Tc-99m DISIDA. This case presents a potential cause for image discordance with these two agents.

  9. Impeding 99Tc(IV) mobility in novel waste forms

    PubMed Central

    Lee, Mal-Soon; Um, Wooyong; Wang, Guohui; Kruger, Albert A.; Lukens, Wayne W.; Rousseau, Roger; Glezakou, Vassiliki-Alexandra

    2016-01-01

    Technetium (99Tc) is an abundant, long-lived radioactive fission product whose mobility in the subsurface is largely governed by its oxidation state. Tc immobilization is crucial for radioactive waste management and environmental remediation. Tc(IV) incorporation in spinels has been proposed as a novel method to increase Tc retention in glass waste forms during vitrification. However, experiments under high-temperature and oxic conditions show reoxidation of Tc(IV) to volatile pertechnetate, Tc(VII). Here we examine this problem with ab initio molecular dynamics simulations and propose that, at elevated temperatures, doping with first row transition metal can significantly enhance Tc retention in magnetite in the order Co>Zn>Ni. Experiments with doped spinels at 700 °C provide quantitative confirmation of the theoretical predictions in the same order. This work highlights the power of modern, state-of-the-art simulations to provide essential insights and generate theory-inspired design criteria of complex materials at elevated temperatures. PMID:27357121

  10. Significance of functional hepatic resection rate calculated using 3D CT/(99m)Tc-galactosyl human serum albumin single-photon emission computed tomography fusion imaging.

    PubMed

    Tsuruga, Yosuke; Kamiyama, Toshiya; Kamachi, Hirofumi; Shimada, Shingo; Wakayama, Kenji; Orimo, Tatsuya; Kakisaka, Tatsuhiko; Yokoo, Hideki; Taketomi, Akinobu

    2016-05-07

    To evaluate the usefulness of the functional hepatic resection rate (FHRR) calculated using 3D computed tomography (CT)/(99m)Tc-galactosyl-human serum albumin (GSA) single-photon emission computed tomography (SPECT) fusion imaging for surgical decision making. We enrolled 57 patients who underwent bi- or trisectionectomy at our institution between October 2013 and March 2015. Of these, 26 patients presented with hepatocellular carcinoma, 12 with hilar cholangiocarcinoma, six with intrahepatic cholangiocarcinoma, four with liver metastasis, and nine with other diseases. All patients preoperatively underwent three-phase dynamic multidetector CT and (99m)Tc-GSA scintigraphy. We compared the parenchymal hepatic resection rate (PHRR) with the FHRR, which was defined as the resection volume counts per total liver volume counts on 3D CT/(99m)Tc-GSA SPECT fusion images. In total, 50 patients underwent bisectionectomy and seven underwent trisectionectomy. Biliary reconstruction was performed in 15 patients, including hepatopancreatoduodenectomy in two. FHRR and PHRR were 38.6 ± 19.9 and 44.5 ± 16.0, respectively; FHRR was strongly correlated with PHRR. The regression coefficient for FHRR on PHRR was 1.16 (P < 0.0001). The ratio of FHRR to PHRR for patients with preoperative therapies (transcatheter arterial chemoembolization, radiation, radiofrequency ablation, etc.), large tumors with a volume of > 1000 mL, and/or macroscopic vascular invasion was significantly smaller than that for patients without these factors (0.73 ± 0.19 vs 0.82 ± 0.18, P < 0.05). Postoperative hyperbilirubinemia was observed in six patients. Major morbidities (Clavien-Dindo grade ≥ 3) occurred in 17 patients (29.8%). There was no case of surgery-related death. Our results suggest that FHRR is an important deciding factor for major hepatectomy, because FHRR and PHRR may be discrepant owing to insufficient hepatic inflow and congestion in patients with preoperative therapies, macroscopic vascular

  11. Development of a Luminex Bead Based Assay for Diagnosis of Toxocariasis Using Recombinant Antigens Tc-CTL-1 and Tc-TES-26.

    PubMed

    Anderson, John P; Rascoe, Lisa N; Levert, Keith; Chastain, Holly M; Reed, Matthew S; Rivera, Hilda N; McAuliffe, Isabel; Zhan, Bin; Wiegand, Ryan E; Hotez, Peter J; Wilkins, Patricia P; Pohl, Jan; Handali, Sukwan

    2015-01-01

    The clinical spectrum of human disease caused by the roundworms Toxocara canis and Toxocara cati ranges from visceral and ocular larva migrans to covert toxocariasis. The parasite is not typically recovered in affected tissues, so detection of parasite-specific antibodies is usually necessary for establishing a diagnosis. The most reliable immunodiagnostic methods use the Toxocara excretory-secretory antigens (TES-Ag) in ELISA formats to detect Toxocara-specific antibodies. To eliminate the need for native parasite materials, we identified and purified immunodiagnostic antigens using 2D gel electrophoresis followed by electrospray ionization mass spectrometry. Three predominant immunoreactive proteins were found in the TES; all three had been previously described in the literature: Tc-CTL-1, Tc-TES-26, and Tc-MUC-3. We generated Escherichia coli expressed recombinant proteins for evaluation in Luminex based immunoassays. We were unable to produce a functional assay with the Tc-MUC-3 recombinant protein. Tc-CTL-1 and Tc-TES-26 were successfully coupled and tested using defined serum batteries. The use of both proteins together generated better results than if the proteins were used individually. The sensitivity and specificity of the assay for detecting visceral larval migrans using Tc-CTL-1 plus Tc-TES-26 was 99% and 94%, respectively; the sensitivity for detecting ocular larval migrans was 64%. The combined performance of the new assay was superior to the currently available EIA and could potentially be employed to replace current assays that rely on native TES-Ag.

  12. Development of a Luminex Bead Based Assay for Diagnosis of Toxocariasis Using Recombinant Antigens Tc-CTL-1 and Tc-TES-26

    PubMed Central

    Anderson, John P.; Rascoe, Lisa N.; Levert, Keith; Chastain, Holly M.; Reed, Matthew S.; Rivera, Hilda N.; McAuliffe, Isabel; Zhan, Bin; Wiegand, Ryan E.; Hotez, Peter J.; Wilkins, Patricia P.; Pohl, Jan; Handali, Sukwan

    2015-01-01

    The clinical spectrum of human disease caused by the roundworms Toxocara canis and Toxocara cati ranges from visceral and ocular larva migrans to covert toxocariasis. The parasite is not typically recovered in affected tissues, so detection of parasite-specific antibodies is usually necessary for establishing a diagnosis. The most reliable immunodiagnostic methods use the Toxocara excretory-secretory antigens (TES-Ag) in ELISA formats to detect Toxocara-specific antibodies. To eliminate the need for native parasite materials, we identified and purified immunodiagnostic antigens using 2D gel electrophoresis followed by electrospray ionization mass spectrometry. Three predominant immunoreactive proteins were found in the TES; all three had been previously described in the literature: Tc-CTL-1, Tc-TES-26, and Tc-MUC-3. We generated Escherichia coli expressed recombinant proteins for evaluation in Luminex based immunoassays. We were unable to produce a functional assay with the Tc-MUC-3 recombinant protein. Tc-CTL-1 and Tc-TES-26 were successfully coupled and tested using defined serum batteries. The use of both proteins together generated better results than if the proteins were used individually. The sensitivity and specificity of the assay for detecting visceral larval migrans using Tc-CTL-1 plus Tc-TES-26 was 99% and 94%, respectively; the sensitivity for detecting ocular larval migrans was 64%. The combined performance of the new assay was superior to the currently available EIA and could potentially be employed to replace current assays that rely on native TES-Ag. PMID:26485145

  13. Clinical significance of TC21 overexpression in oral cancer.

    PubMed

    Macha, Muzafar A; Matta, Ajay; Sriram, Uma; Thakkar, Alok; Shukla, N K; Datta Gupta, Siddhartha; Ralhan, Ranju

    2010-07-01

    In search of novel molecular markers for oral cancer, we reported increased levels of TC21/R-Ras2 transcripts in oral squamous cell carcinoma by differential display. The aim of this study was to determine the clinical significance of TC21 in oral cancer. Immunohistochemical analysis of TC21 protein expression was carried out in 120 leukoplakias, 83 OSCCs and 30 non-malignant tissues, confirmed by immunoblotting, and correlated with clinicopathological parameters as well as disease prognosis. Co-immunoprecipitation assays were carried out to identify the interaction partners of TC21 protein in oral cancer cells and tissues. TC21 nuclear expression increased from normal oral tissues to leukoplakia and frank malignancy (P < 0.001). TC21 overexpression was observed in 74.2% leukoplakia with no dysplasia, 75.9% dysplasias and 79.5% OSCCs in comparison with normal oral tissues. Receiver operating characteristic analysis showed that the area-under-the curve values were 0.895, 0.885, and 0.919, while the positive predictive values were 95.8%, 95.6%, and 97.1%, for nuclear immunostaining for normal versus leukoplakia with no dysplasia, leukoplakic lesions with dysplasia, and OSCCs, respectively. Immunoblotting confirmed overexpression of TC21 in oral lesions. Using co-immunoprecipitation assays, we showed interactions of TC21 with Erk2, PI3-K, 14-3-3zeta and 14-3-3sigma proteins in oral cancer cells. Our findings suggested that alteration in TC21 expression is an early event in oral cancer and correlates with poor prognosis of OSCCs. TC21 interactions with Erk2, PI3-K, 14-3-3zeta and 14-3-3sigma proteins in oral cancer cells and tissues suggests the involvement of TC21 in signaling pathways in oral cancer.

  14. Bronchial and non-bronchial systemic arteries: value of multidetector CT angiography in diagnosis and angiographic embolisation feasibility analysis.

    PubMed

    Lin, Yuning; Chen, Ziqian; Yang, Xizhang; Zhong, Qun; Zhang, Hongwen; Yang, Li; Xu, Shangwen; Li, Hui

    2013-12-01

    The aim of this study is to evaluate the diagnostic performance of multidetector CT angiography (CTA) in depicting bronchial and non-bronchial systemic arteries in patients with haemoptysis and to assess whether this modality helps determine the feasibility of angiographic embolisation. Fifty-two patients with haemoptysis between January 2010 and July 2011 underwent both preoperative multidetector CTA and digital subtraction angiography (DSA) imaging. Diagnostic performance of CTA in depicting arteries causing haemoptysis was assessed on a per-patient and a per-artery basis. The feasibility of the endovascular treatment evaluated by CTA was analysed. Sensitivity, specificity, and positive and negative predictive values for those analyses were determined. Fifty patients were included in the artery-presence-number analysis. In the per-patient analysis, neither CTA (P = 0.25) nor DSA (P = 1.00) showed statistical difference in the detection of arteries causing haemoptysis. The sensitivity, specificity, and positive and negative predictive values were 94%, 100%, 100%, and 40%, respectively, for the presence of pathologic arteries evaluated by CTA, and 98%, 100%, 100%, and 67%, respectively, for DSA. On the per-artery basis, CTA correctly identified 97% (107/110). Fifty-two patients were included in the feasibility analysis. The performance of CTA in predicting the feasibility of angiographic embolisation was not statistically different from the treatment performed (P = 1.00). The sensitivity, specificity, and positive and negative predictive values were 96%, 80%, 98% and 67%, respectively, for CTA. Multidetector CTA is an accurate imaging method in depicting the presence and number of arteries causing haemoptysis. This modality is also useful for determining the feasibility of angiographic embolisation for haemoptysis. © 2013 The Authors. Journal of Medical Imaging and Radiation Oncology © 2013 The Royal Australian and New Zealand College of Radiologists.

  15. Infection with Trypanosoma cruzi TcII and TcI in free-ranging population of lion tamarins (Leontopithecus spp): an 11-year follow-up.

    PubMed

    Lisboa, Cristiane Varella; Monteiro, Rafael Veríssimo; Martins, Andreia Fonseca; Xavier, Samantha Cristina das Chagas; Lima, Valdirene Dos Santos; Jansen, Ana Maria

    2015-05-01

    Here, we present a review of the dataset resulting from the 11-years follow-up of Trypanosoma cruzi infection in free-ranging populations of Leontopithecus rosalia (golden lion tamarin) and Leontopithecus chrysomelas (golden-headed lion tamarin) from distinct forest fragments in Atlantic Coastal Rainforest. Additionally, we present new data regarding T. cruzi infection of small mammals (rodents and marsupials) that live in the same areas as golden lion tamarins and characterisation at discrete typing unit (DTU) level of 77 of these isolates. DTU TcII was found to exclusively infect primates, while TcI infected Didelphis aurita and lion tamarins. The majority of T. cruzi isolates derived from L. rosalia were shown to be TcII (33 out 42) Nine T. cruzi isolates displayed a TcI profile. Golden-headed lion tamarins demonstrated to be excellent reservoirs of TcII, as 24 of 26 T. cruzi isolates exhibited the TcII profile. We concluded the following: (i) the transmission cycle of T. cruzi in a same host species and forest fragment is modified over time, (ii) the infectivity competence of the golden lion tamarin population fluctuates in waves that peak every other year and (iii) both golden and golden-headed lion tamarins are able to maintain long-lasting infections by TcII and TcI.

  16. Quantitative measurement of radiofrequency volumetric tissue reduction by multidetector CT in patients with inferior turbinate hypertrophy.

    PubMed

    Bahadir, Osman; Kosucu, Polat

    2012-12-01

    To objectively assess the efficacy of radiofrequency thermal ablation of inferior turbinate hypertrophy. Thirty-five patients with nasal obstruction secondary to inferior turbinate hypertrophy were prospectively enrolled. Radiofrequency energy was delivered to four sites in each inferior turbinate. Patients were evaluated before and 8 weeks after intervention. Subjective evaluation of nasal obstruction was performed using a visual analogue scale (VAS), and objective evaluation of the turbinate volume reduction was calculated using multidetector CT. Volumetric measurements of the preoperative inferior turbinate were compared with postoperative values on both sides. The great majority of patients (91.4%) exhibited subjective postoperative improvement. Mean obstruction (VAS) improved significantly from 7.45±1.48 to 3.54±1.96. Significant turbinate volume reduction was achieved by the surgery on both right and left sides [(preoperative vs. postoperative, right: 6.55±1.62cm(3) vs. 5.10±1.47cm(3), (P<0.01); left: 6.72±1.53cm(3) vs. 5.00±1.37cm(3), (P<0.01)] respectively. Radiofrequency is a safe and effective surgical procedure in reducing turbinate volume in patients with inferior turbinate hypertrophy. Multidetector CT is an objective method of assessment in detecting radiofrequency turbinate volume reduction. Copyright © 2012 Elsevier Ireland Ltd. All rights reserved.

  17. Anatomical Variations of the Right Adrenal Vein: Concordance Between Multidetector Computed Tomography and Catheter Venography.

    PubMed

    Omura, Kensuke; Ota, Hideki; Takahashi, Yuuki; Matsuura, Tomonori; Seiji, Kazumasa; Arai, Yoichi; Morimoto, Ryo; Satoh, Fumitoshi; Takase, Kei

    2017-03-01

    Adrenal venous sampling is the most reliable diagnostic procedure to determine surgical indications in primary aldosteronism. Because guidelines recommend multidetector computed tomography (CT) to evaluate the adrenal gland, some past reports used multidetector CT as a guide for adrenal venous sampling. However, the detailed anatomy of the right adrenal vein and its relationship with an accessory hepatic vein remains uncertain. The purpose of this study was to describe detailed anatomical variations of the right adrenal vein and to determine the concordance between CT and catheter venography in patients with primary aldosteronism. In total, 440 consecutive patients who underwent adrenal venous sampling were included. Four-phase dynamic CT was performed. Anatomical locations and variations of the right adrenal vein and its relationship with the accessory hepatic vein were compared with catheter venographic findings. Successful catheterization was achieved in 437 patients (99%). The right adrenal vein was visualized in the late arterial phase with CT in 420 patients (95%). The right adrenal vein formed a common trunk with the accessory hepatic vein in 87 patients (20%). CT identified the correct craniocaudal level of the orifice in 354 patients (84%). Anatomical variations, location, and angle of inflow of the right adrenal vein based on CT demonstrated high concordance with catheter venography. CT may provide useful information for preparation before adrenal venous sampling. © 2017 American Heart Association, Inc.

  18. Imaging of acute mesenteric ischemia using multidetector CT and CT angiography in a porcine model.

    PubMed

    Rosow, David E; Sahani, Dushyant; Strobel, Oliver; Kalva, Sanjeeva; Mino-Kenudson, Mari; Holalkere, Nagaraj S; Alsfasser, Guido; Saini, Sanjay; Lee, Susanna I; Mueller, Peter R; Fernández-del Castillo, Carlos; Warshaw, Andrew L; Thayer, Sarah P

    2005-12-01

    Acute mesenteric ischemia, a frequently lethal disease, requires prompt diagnosis and intervention for favorable clinical outcomes. This goal remains elusive due, in part, to lack of a noninvasive and accurate imaging study. Traditional angiography is the diagnostic gold standard but is invasive and costly. Computed tomography (CT) is readily available and noninvasive but has shown variable success in diagnosing this disease. The faster scanning time of multidetector row CT (M.D.CT) greatly facilitates the use of CT angiography (CTA) in the clinical setting. We sought to determine whether M.D.CT-CTA could accurately demonstrate vascular anatomy and capture the earliest stages of mesenteric ischemia in a porcine model. Pigs underwent embolization of branches of the superior mesenteric artery, then imaging by M.D.CT-CTA with three-dimensional reconstruction protocols. After scanning, diseased bowel segments were surgically resected and pathologically examined. Multidetector row CT and CT angiography reliably defined normal and occluded mesenteric vessels in the pig. It detected early changes of ischemia including poor arterial enhancement and venous dilatation, which were seen in all ischemic animals. The radiographic findings--compared with pathologic diagnoses-- predicted ischemia, with a positive predictive value of 92%. These results indicate that M.D.CT-CTA holds great promise for the early detection necessary for successful treatment of acute mesenteric ischemia.

  19. [99mTc(V)-DMSA accumulation in gynecomastia].

    PubMed

    Ohta, H

    1998-11-01

    The accumulation of 99mTc(V)-DMSA in bilateral breasts was recognized in a 60-year-old male with drug-induced gynecomastia. There are some reports describing 99mTc(V)-DMSA accumulation in normal female breast, fibrous dysplasia of the breast and metastatic lesions of breast carcinoma, but to my knowledge, there have been no reports describing 99mTc(V)-DMSA accumulation in gynecomastia.

  20. Tc17 cells in patients with uterine cervical cancer.

    PubMed

    Zhang, Yan; Hou, Fei; Liu, Xin; Ma, Daoxin; Zhang, Youzhong; Kong, Beihua; Cui, Baoxia

    2014-01-01

    The existence of Tc17 cells was recently shown in several types of infectious and autoimmune diseases, but their distribution and functions in uterine cervical cancer (UCC) have not been fully elucidated. The frequency of Tc17 cells in peripheral blood samples obtained from UCC patients, cervical intraepithelial neoplasia (CIN) patients and healthy controls was determined by flow cytometry. Besides, the prevalence of Tc17 cells and their relationships to Th17 cells and Foxp3-expressing T cells as well as microvessels in tissue samples of the patients were assessed by immunohistochemistry staining. Compared to controls, patients with UCC or CIN had a higher proportion of Tc17 cells in both peripheral blood and cervical tissues, but the level of Tc17 cells in UCC tissues was significantly higher than that in CIN tissues. Besides, the increased level of Tc17 in UCC patients was associated with the status of pelvic lymph node metastases and increased microvessel density. Finally, significant correlations of infiltration between Tc17 cells and Th17 cells or Foxp3-expressing T cells were observed in UCC and CIN tissues. This study indicates that Tc17 cell infiltration in cervical cancers is associated with cancer progression accompanied by increased infiltrations of Th17 cells and regulatory T cells as well as promoted tumor vasculogenesis.

  1. Tc17 Cells in Patients with Uterine Cervical Cancer

    PubMed Central

    Zhang, Yan; Hou, Fei; Liu, Xin; Ma, Daoxin; Zhang, Youzhong; Kong, Beihua; Cui, Baoxia

    2014-01-01

    Background The existence of Tc17 cells was recently shown in several types of infectious and autoimmune diseases, but their distribution and functions in uterine cervical cancer (UCC) have not been fully elucidated. Methods The frequency of Tc17 cells in peripheral blood samples obtained from UCC patients, cervical intraepithelial neoplasia (CIN) patients and healthy controls was determined by flow cytometry. Besides, the prevalence of Tc17 cells and their relationships to Th17 cells and Foxp3-expressing T cells as well as microvessels in tissue samples of the patients were assessed by immunohistochemistry staining. Results Compared to controls, patients with UCC or CIN had a higher proportion of Tc17 cells in both peripheral blood and cervical tissues, but the level of Tc17 cells in UCC tissues was significantly higher than that in CIN tissues. Besides, the increased level of Tc17 in UCC patients was associated with the status of pelvic lymph node metastases and increased microvessel density. Finally, significant correlations of infiltration between Tc17 cells and Th17 cells or Foxp3-expressing T cells were observed in UCC and CIN tissues. Conclusions This study indicates that Tc17 cell infiltration in cervical cancers is associated with cancer progression accompanied by increased infiltrations of Th17 cells and regulatory T cells as well as promoted tumor vasculogenesis. PMID:24523865

  2. Synthesis, Characterization, and Initial Biological Evaluation of [99m Tc]Tc-Tricarbonyl-labeled DPA-α-MSH Peptide Derivatives for Potential Melanoma Imaging.

    PubMed

    Gao, Feng; Sihver, Wiebke; Bergmann, Ralf; Belter, Birgit; Bolzati, Cristina; Salvarese, Nicola; Steinbach, Jörg; Pietzsch, Jens; Pietzsch, Hans-Jürgen

    2018-06-06

    α-Melanocyte stimulating hormone (α-MSH) derivatives target the melanocortin-1 receptor (MC1R) specifically and selectively. In this study, the α-MSH-derived peptide NAP-NS1 (Nle-Asp-His-d-Phe-Arg-Trp-Gly-NH 2 ) with and without linkers was conjugated with 5-(bis(pyridin-2-ylmethyl)amino)pentanoic acid (DPA-COOH) and labeled with [ 99m Tc]Tc-tricarbonyl by two methods. With the one-pot method the labeling was faster than with the two-pot method, while obtaining similarly high yields. Negligible trans-chelation and high stability in physiological solutions was determined for the [ 99m Tc]Tc-tricarbonyl-peptide conjugates. Coupling an ethylene glycol (EG)-based linker increased the hydrophilicity. The peptide derivatives displayed high binding affinity in murine B16F10 melanoma cells as well as in human MeWo and TXM13 melanoma cell homogenates. Preliminary in vivo studies with one of the [ 99m Tc]Tc-tricarbonyl-peptide conjugates showed good stability in blood and both renal and hepatobiliary excretion. Biodistribution was performed on healthy rats to gain initial insight into the potential relevance of the 99m Tc-labeled peptides for in vivo imaging. © 2018 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.

  3. Re-Search for Extinct 99Tc and 98Tc in the Early Solar System

    NASA Astrophysics Data System (ADS)

    Yin, Q.; Jagoutz, E.; Wanke, H.

    1992-07-01

    The recent advances in negative thermal ionization mass spectrometry (N-TIMS) of Re and Os (Creaser et al., 1991) offer a new chance to search for isotopic anomalies of ruthenium (Ru) (and possibly Mo) in meteorites. The Ru isotopes are particularly important since they contain two daughter decay products of technicium, ^98Tc (tau(sub)1/2=4.2x10^6 yr) and ^99Tc (tau(sub)1/2=2.1x10^5 yr). Natural Tc is now extinct on Earth due to their short half-life, but may have been present in the early solar system; Ru isotopes might also bear witness of the various processes of nucleosynthesis and of the imperfect mixing of their products in the pre-solar nebula; Ru isotopic composition in fission is drastically different from natural; ^99Tc is crucial because of its very short half-life and is observed directly for several half-lives in s-process-enriched stars during the thermally pulsing, AGB (asymptotic giant branch) phase of evolution. The probability of detecting ^99Tc in this type of stars is typically 70% (Smith and Lambert, 1988). The chemical similarities between Ru and Os yield correspondingly high ionization efficiency for Ru with N-TIMS. Ru is obtained as a byproduct of Os chemistry, as Ru co-distills with Os. This unique combination conveniently enables a survey for extinct Tc by determining isotopic composition of Ru on a wide range of samples together with extensive studies of Re-Os system in geochemical community in the years to come. These arguments prompted us to carry out a systematic re-search for Ru isotopic anomalies initiated by Herr and coworkers more than 30 years ago (Herr et al., 1958). We have measured Ru isotopic composition in one bulk sample and a magnetic fraction of Maralinga carbonaceous chondrite and one bulk sample of the iron meteorite Gibeon. The bulk sample of Maralinga is found to be isotopically indistinguishable from the terrestrial values within analytical uncertainties. In the magnetic fraction, however, a positive deviation (0

  4. Tc-99m Ethylenedicysteine and Tc-99m Dimercaptosuccinic Acid Scintigraphy-Comparison of the Two for Detection of Scarring and Differential Cortical Function.

    PubMed

    Dharmalingam, Anitha; Pawar, Shwetal U; Parelkar, Sandesh V; Shetye, Suruchi S; Ghorpade, Mangala K; Tilve, Gundu H

    2017-01-01

    The differential cortical function obtained by Tc-99m EC is comparable to that of Tc-99m DMSA. However, identification of scars on Tc-99m EC images needs to be studied. The aim of the study is to evaluate role of Tc-99m EC for detection of scarring and differential cortical function by comparing with Tc-99m DMSA. Prospective observational study of recurrent UTI; minimum 6 weeks after acute episode; when urine examination is negative for pus cells. Forty-seven children with normal positioned kidneys underwent Tc-99m EC and DMSA scintigraphy. The DRF and cortical phase images of both studies in the same image matrix size were evaluated by two independent observers for scarring; Tc-99m DMSA was considered as the gold standard. MS Excel 2007 and GraphPad Instat V3.1 and ROC analysis. There was no significant difference in the detection of scarring using two studies with Cohen's kappa coefficient (κ) 0.932. The sensitivity and specificity of Tc-99m EC for detection of scarring was 98.75% and 99.15%, respectively. There was good agreement between the differential cortical function calculated using two studies. The summed Tc-99m EC images with an acceptable high image contrast allow detection of cortical scarring in patients with normal kidney positions. It is an excellent single-modality comprehensive investigational agent for renal parenchymal defects, function, and excretion evaluation with the added advantages of lower cost, convenience, and low radiation exposure to the child.

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

    PubMed

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

    2017-08-15

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

  6. Infection with Trypanosoma cruzi TcII and TcI in free-ranging population of lion tamarins (Leontopithecus spp): an 11-year follow-up

    PubMed Central

    Lisboa, Cristiane Varella; Monteiro, Rafael Veríssimo; Martins, Andreia Fonseca; Xavier, Samantha Cristina das Chagas; Lima, Valdirene dos Santos; Jansen, Ana Maria

    2015-01-01

    Here, we present a review of the dataset resulting from the 11-years follow-up of Trypanosoma cruzi infection in free-ranging populations of Leontopithecus rosalia (golden lion tamarin) and Leontopithecus chrysomelas (golden-headed lion tamarin) from distinct forest fragments in Atlantic Coastal Rainforest. Additionally, we present new data regarding T. cruzi infection of small mammals (rodents and marsupials) that live in the same areas as golden lion tamarins and characterisation at discrete typing unit (DTU) level of 77 of these isolates. DTU TcII was found to exclusively infect primates, while TcI infected Didelphis aurita and lion tamarins. The majority of T. cruzi isolates derived from L. rosalia were shown to be TcII (33 out 42) Nine T. cruzi isolates displayed a TcI profile. Golden-headed lion tamarins demonstrated to be excellent reservoirs of TcII, as 24 of 26 T. cruzi isolates exhibited the TcII profile. We concluded the following: (i) the transmission cycle of T. cruzi in a same host species and forest fragment is modified over time, (ii) the infectivity competence of the golden lion tamarin population fluctuates in waves that peak every other year and (iii) both golden and golden-headed lion tamarins are able to maintain long-lasting infections by TcII and TcI. PMID:25946156

  7. Acute Perforated Diverticulitis: Assessment With Multidetector Computed Tomography.

    PubMed

    Sessa, Barbara; Galluzzo, Michele; Ianniello, Stefania; Pinto, Antonio; Trinci, Margherita; Miele, Vittorio

    2016-02-01

    Colonic diverticulitis is a common condition in the western population. Complicated diverticulitis is defined as the presence of extraluminal air or abscess, peritonitis, colon occlusion, or fistulas. Multidetector row computed tomography (MDCT) is the modality of choice for the diagnosis and the staging of diverticulitis and its complications, which enables performing an accurate differential diagnosis and addressing the patients to a correct management. MDCT is accurate in diagnosing the site of perforation in approximately 85% of cases, by the detection of direct signs (focal bowel wall discontinuity, extraluminal gas, and extraluminal enteric contrast) and indirect signs, which are represented by segmental bowel wall thickening, abnormal bowel wall enhancement, perivisceral fat stranding of fluid, and abscess. MDCT is accurate in the differentiation from complicated colon diverticulitis and colon cancer, often with a similar imaging. The computed tomography-guided classification is recommended to discriminate patients with mild diverticulitis, generally treated with antibiotics, from those with severe diverticulitis with a large abscess, which may be drained with a percutaneous approach. Copyright © 2016 Elsevier Inc. All rights reserved.

  8. Effective visualization of suppressed thyroid tissue by means of baseline 99mTc-methoxy isobutyl isonitrile in comparison with 99mTc-pertechnetate scintigraphy after TSH stimulation.

    PubMed

    Vattimo, A; Bertelli, P; Burroni, L

    1992-01-01

    Baseline 99mTc-MIBI thyroid scintigraphy was compared with 99mTc-pertechnetate scintigraphy after TSH stimulation in seven patients with suppressed thyroid tissue due to an autonomously functioning thyroid nodule (AFTN). In all patients the suppressed thyroid tissue was visualized by means of both baseline 99mTc-MIBI and post-TSH 99mTc-pertechnetate scintigraphy, and in some cases the former technique provided better visualization. In one patient presenting a "warm" nodule T3-suppression did not affect the nodular/extranodular uptake ratio of 99mTc-MIBI, whereas the 99mTc-pertechnetate uptake ratio increased significantly. This leads us to hypothesize that the thyroid uptake of 99mTc-MIBI is not related to TSH control, but rather to other mechanisms such as the blood flow. Since exogenous TSH is no longer available, 99mTc-MIBI scintigraphy can be successfully used in the place of repeated 99mTc-pertechnetate scintigraphy after TSH stimulation in the assessment of AFTN.

  9. An ancient Roman bowl embedded in a soil sample: surface shaded three dimensional display using data from a multi-detector CT.

    PubMed

    De Maeseneer, M; Buls, N; Cleeren, N; Lenchik, L; De Mey, J

    2006-01-01

    We present an unusual application of multidetector CT and shaded surface rendering in the investigation of a soil sample, containing an ancient Roman bronze bowl. The CT findings were of fundamental importance in helping the archaeologists study the bronze bowl from the soil sample.

  10. Recent technologic advances in multi-detector row cardiac CT.

    PubMed

    Halliburton, Sandra Simon

    2009-11-01

    Recent technical advances in multi-detector row CT have resulted in lower radiation dose, improved temporal and spatial resolution, decreased scan time, and improved tissue differentiation. Lower radiation doses have resulted from the use of pre-patient z collimators, the availability of thin-slice axial data acquisition, the increased efficiency of ECG-based tube current modulation, and the implementation of iterative reconstruction algorithms. Faster gantry rotation and the simultaneous use of two x-ray sources have led to improvements in temporal resolution, and gains in spatial resolution have been achieved through application of the flying x-ray focal-spot technique in the z-direction. Shorter scan times have resulted from the design of detector arrays with increasing numbers of detector rows and through the simultaneous use of two x-ray sources to allow higher helical pitch. Some improvement in tissue differentiation has been achieved with dual energy CT. This article discusses these recent technical advances in detail.

  11. Femoral head avascular necrosis: a frequently missed incidental finding on multidetector CT.

    PubMed

    Barille, M F; Wu, Jim S; McMahon, Colm J

    2014-03-01

    To determine the incidence of missed femoral head avascular necrosis (AVN) on pelvic computed tomography (CT) performed for clinical indications other than assessment for AVN. The study was a Health Insurance Portability and Accountability Act (HIPAA)-compliant retrospective study. The picture archiving and communication system (PACS) database was queried for patients with diagnosis of femoral head AVN on magnetic resonance imaging (MRI), who also underwent pelvic multidetector CT after or <30 days before the MRI examination. The MRI and CT images of 144 hips of 72 patients (39 patients with reported AVN on MRI and 33 age-matched controls; mean age = 60 years, 28 male, 44 female), were reviewed in consensus by two readers in a randomized, blinded manner. Using MRI-proven CT-visible AVN as a reference standard, the incidence of missed AVN on initial CT interpretation was determined. Readers confirmed AVN in 33 patients on the MRI images. Nine hips with AVN underwent joint replacement of the affected joint(s) prior to subsequent CT and were excluded. Forty-three MRI-proven AVN cases in 28 patients (15 bilateral, 13 unilateral) were available for analysis. The study readers diagnosed 35/43 (81%) MRI-proven AVN cases in 22/28 (79%) patients. Four of the 35 (11%) cases of MRI-proven, CT-visible AVN were prospectively reported in 3/22 (14%) patients at initial clinical interpretation, with a miss rate of 89% per hip and 86% per patient. Multidetector CT has high accuracy for detection of AVN; however, this is frequently missed as an incidental finding (89% missed in the present study). Assessment for signs of femoral AVN should be part of routine search pattern in interpretation of pelvic CT. Copyright © 2013 The Royal College of Radiologists. Published by Elsevier Ltd. All rights reserved.

  12. Getters for Tc and I Removal from Liquid Waste

    NASA Astrophysics Data System (ADS)

    Qafoku, N. P.; Asmussen, M.; Lawter, A.; Neeway, J.; Smith, G.

    2015-12-01

    A cementitious waste form, Cast Stone, is being evaluated as a possible supplemental waste form for the low activity waste (LAW) at the Hanford Site, which contains significant amounts of radioactive 99Tc and 129I, as part of the tank waste cleanup mission. To improve the retention of Tc and/or I in Cast Stone, materials with a high affinity for Tc and/or I, termed "getters," can be added to decrease the rate of contaminant release and diffusivity, and improve Cast Stone performance. A series of kinetic batch sorption experiments was performed to determine the effectiveness of the getter materials. Several Tc getters [blast furnace slag, Sn (II) apatite, SnCl2, nanoporous Sn phosphate, KMS-2 (a potassium-metal-sulfide), and Sn(II) hydroxyapatite] and I getters [layered Bi hydroxide, natural argentite mineral, synthetic argentite, Ag-impregnated carbon, and Ag-exchanged zeolite] were tested in different solution media, 18.2 MΩ DI H2O and a caustic LAW waste simulant containing 6.5 M Na or 7.8 M Na. The experiments were conducted at room temperature in the presence or absence of air. Results indicated that most Tc getters (with the exception of KMS-2) performed better in the DI H2O solution than in the 6.5 and 7.8 M Na LAW simulant. In addition, Tc sequestration may be affected by the presence of other redox sensitive elements that were present in the LAW simulant, such as Cr. The Tc getter materials have been examined through various solid-state characterization techniques such as XRD, SEM/EDS, XANES and EXAFS which provided evidence for plausible mechanisms of aqueous Tc removal. The results indicated that the Tc precipitates differ depending on the getter material and that Tc(VII) is reduced to Tc(IV) in most of the getters but to a differing extents. For the I getters, Ag-exchanged zeolite and synthetic argentite were the most effective ones. The other I getters showed limited effectiveness for sorbing I under the high ionic strength and caustic

  13. APOA5 -1131T>C and APOC3 -455T>C polymorphisms are associated with an increased risk of coronary heart disease.

    PubMed

    Sun, Y; Zhou, R B; Chen, D M

    2015-12-28

    The aim of this study was to investigate correlations between apolipoprotein A-V (APOA5) -1131T>C and apolipoprotein C-III (APOC3) -455T>C polymorphisms and coronary heart disease (CHD). PubMed, Ovid, Cochrane Library, Embase, China National Knowledge Infrastructure, and Wanfang databases were searched using combinations of keywords relating to these polymorphisms and CHD. Studies retrieved from database searches were screened using our stringent inclusion and exclusion criteria, and Comprehensive Meta-Analysis Version 2.0 software was used for statistical analyses. In total, 115 studies were initially retrieved and after further selection, 11 were included in the meta-analysis. These 11 articles comprised 4840 patients with CHD in the case group and 4913 healthy participants in the control group. Meta-analysis revealed that APOA5 -1131T>C and APOC3 -455T>C polymorphisms increased CHD risk. In addition, subgroup analysis by ethnicity showed that while the -1131T>C polymorphism elevated the risk of CHD in the Caucasian population under both allelic and dominant models, this increased risk was observed only under a dominant model in the Asian population. The results of our meta-analysis point to a strong link between both APOA5 -1131T>C and APOC3 -455T>C polymorphisms and an increased risk of CHD. Thus, these polymorphisms constitute important predictive indicators of CHD susceptibility.

  14. Tc-NGA imaging in liver transplantation: preliminary clinical experience

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Woodle, E.S.; Ward, R.E.; Stadalnik, R.C.

    1989-03-01

    Technetium-99m galactosyl-neoglycoalbumin (Tc-NGA) is a new liver imaging agent that binds to hepatic-binding protein, a hepatocyte-specific membrane receptor. The purpose of this study was to determine the potential of Tc-NGA imaging in clinical liver transplantation. A total of 25 studies were performed in nine patients. Imaging studies performed in the early posttransplant period in patients with good hepatic allograft function revealed diffuse patchiness in tracer distribution, a manifestation of preservation damage. Left lobar infarction was demonstrated within a few hours of ischemic injury. Right posterior segmental infarction was seen in another patient. Comparison of kinetic, clinical, and biochemical data revealedmore » good correlation between hepatic allograft function and Tc-NGA kinetics. Major kinetic alterations were noted during periods of preservation injury, hepatic infarction, and acute rejection. These studies indicate: (1) major alterations in Tc-NGA kinetics occur during preservation injury, hepatic infarction, and acute rejection, and (2) Tc-NGA kinetic data appear to provide an accurate reflection of hepatic allograft function. Tc-NGA imaging has the advantages of being noninvasive and of utilizing standard nuclear medicine instrumentation, including portable imaging devices. In conclusion, Tc-NGA imaging provides a promising noninvasive approach for evaluation of liver function in patients undergoing hepatic transplantation.« less

  15. 77 FR 54908 - TC Offshore, LLC; Notice Establishing Deadline for Comments

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-09-06

    ... DEPARTMENT OF ENERGY Federal Energy Regulatory Commission [Docket No. RP12-908-000] TC Offshore, LLC; Notice Establishing Deadline for Comments On August 29, 2012, TC Offshore, LLC (TC Offshore... is hereby given that participants in the captioned proceedings may file comments to TC Offshsore's...

  16. Multidetector CT diagnosis of massive hemobilia due to gallbladder polyposis in a child with metachromatic leukodystrophy.

    PubMed

    Wanner, Matthew R; Karmazyn, Boaz; Fan, Rong

    2015-12-01

    Hemobilia secondary to gallbladder polyposis is rare in children but has been reported in a few children with metachromatic leukodystrophy. We present a case with preoperative multidetector computed tomography (MDCT) diagnosis of massive hemobilia caused by gallbladder polyposis in a patient with metachromatic leukodystrophy. Our report highlights the importance of both awareness of the association of gallbladder polyposis with other syndromes such as metachromatic leukodystrophy as well as the possibility of this entity presenting with life-threatening bleeding.

  17. 75 FR 5855 - Proposed Collection; Comment Request for Form 8038-TC

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-02-04

    ... 8038-TC AGENCY: Internal Revenue Service (IRS), Treasury. ACTION: Notice and request for comments... comments concerning Form 8038-TC, Information Return for Tax Credit Bonds. DATES: Written comments should...: Form 8038-TC. Abstract: Form 8038-TC will be used by issuers of qualified tax- exempt credit bonds...

  18. Tc-99m Labeled carrier for imaging

    DOEpatents

    Henze, Eberhard

    1984-01-01

    Novel radionuclide imaging agents, having particular application for lymphangiography are provided by non-covalently binding Tc-99m to a pharmaceutically acceptable cross-linked polysaccharide. Upon injection of the Tc-99m labeled polysaccharide into the blood stream, optimum contrast can be obtained within one hour.

  19. Use of multidetector computed tomography in the assessment of dogs with pericardial effusion.

    PubMed

    Scollan, K F; Bottorff, B; Stieger-Vanegas, S; Nemanic, S; Sisson, D

    2015-01-01

    Contrast-enhanced multidetector computed tomography (MDCT) allows high spatial and temporal resolution imaging of cardiac, thoracic, and abdominal structures. Accurate determination of the cause of pericardial effusion (PE) is essential to providing appropriate treatment and prognosis. Echocardiography and pericardial fluid analysis may not differentiate between causes of PE and cannot identify extracardiac metastasis. Describe the thoracic and abdominal MDCT findings and evaluate the utility of MDCT to differentiate between neoplastic and nonneoplastic causes of PE in dogs. Eleven client-owned dogs with PE diagnosed by echocardiography. Prospective observational study. Transthoracic echocardiography (TTE), 3-view thoracic radiography, and contrast-enhanced thoracic and abdominal MDCT images were evaluated for the presence of cardiac masses, pulmonary metastases, and abdominal masses. Histopathology in 5 dogs and survival analysis in all dogs were evaluated. A neoplastic cause was identified in 6/11 dogs and a nonneoplastic cause was identified in 5/11. Cardiac MDCT findings were consistent with TTE findings in all dogs with right atrial (5/5) and heart base masses (1/1). Pulmonary metastases were identified in 1/11 dogs by thoracic radiography and in 2/11 dogs by MDCT. MDCT identified splenic or hepatic lesions consistent with neoplasia in 6/11 and 5/11 dogs, respectively. Focal MDCT pericardial changes at the pericardiocentesis site were noted in 3/11 dogs. Multidetector computed tomography did not improve the detection of cardiac masses in dogs with PE over echocardiography. The benefit of MDCT was primarily in the detection of pulmonary metastases and extracardiac lesions using a single imaging modality. Copyright © 2014 by the American College of Veterinary Internal Medicine.

  20. 78 FR 40824 - Proposed Collection; Comment Request for Form 8038-TC

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-07-08

    ... 8038-TC AGENCY: Internal Revenue Service (IRS), Treasury. ACTION: Notice and request for comments... Form 8038-TC, Information Return for Tax Credit Bonds. DATES: Written comments should be received on or...-TC. Abstract: Form 8038-TC will be used by issuers of qualified tax- exempt credit bonds, including...

  1. Multi-detector CT angiography of the aortic valve—Part 2: disease specific findings

    PubMed Central

    Ganeshan, Arul

    2014-01-01

    The aortic valve and adjacent structures should be routinely evaluated on all thoracic cross-sectional imaging studies. Echocardiography and magnetic resonance imaging (MRI) are the main imaging techniques used for assessment of the aortic valve and related pathology but multi-detector computed tomography (MDCT) can offer valuable complimentary information in some clinical scenarios. MDCT is the definite means of assessing aortic valvular calcification, acute aortic syndrome and for non-invasive assessment of the coronary arteries. MDCT also has an emerging role in the planning and follow-up of trans-catheter aortic valve replacement. This article reviews the spectrum of aortic valve disease highlighting the key MDCT imaging features. PMID:25202663

  2. Tc-99m Glu-Cys-Gly-His-Gly-Lys (ECG-HGK), a novel Tc-99m labeled hexapeptide for molecular tumor imaging.

    PubMed

    Kim, Dae-Weung; Kim, Myoung Hyoun; Kim, Chang Guhn

    2016-03-01

    Domain 5 of kinin-free high molecular weight kininogen inhibits the adhesion of many tumor cell lines, and it has been reported that the histidine-glycine-lysine (HGK)-rich region might be responsible for inhibition of cell adhesion. The authors developed HGK-containing hexapeptide, glutamic acid-cysteine-glycine (ECG)-HGK, and evaluated the utility of Tc-99m ECG-HGK for tumor imaging. Hexapeptide, ECG-HGK was synthesized using Fmoc solid-phase peptide synthesis. Radiolabeling efficiency was evaluated. The uptake of Tc-99m ECG-HGK within HT-1080 cells was evaluated in vitro. In HT-1080 tumor-bearing mice, gamma imaging and biodistribution studies were performed. The complexes Tc-99m ECG-HGK was prepared in high yield. The uptake of Tc-99m ECG-HGK within the HT-1080 tumor cells had been demonstrated by in vitro studies. The gamma camera imaging in the murine model showed that Tc-99m ECG-HGK was accumulated substantially in the HT-1080 tumor (tumor-to-muscle ratio = 5.7 ± 1.4 at 4 h), and the tumoral uptake was blocked by the co-injection of excess HGK (tumor-to-muscle ratio = 2.8 ± 0.6 at 4 h). In the present study, Tc-99m ECG-HGK was developed as a new tumor imaging agents. Our in vitro and in vivo studies revealed specific function of Tc-99m ECG-HGK for tumor imaging. Copyright © 2016 John Wiley & Sons, Ltd.

  3. PREFACE: 2013 Joint IMEKO (International Measurement Confederation) TC1-TC7-TC13 Symposium: Measurement Across Physical and Behavioural Sciences

    NASA Astrophysics Data System (ADS)

    Battista Rossi, Giovanni; Crenna, Francesco; Belotti, Vittorio

    2013-09-01

    The 2013 Joint IMEKO (International Measurement Confederation) TC1-C7-TC13 was organised by the University of Genova - DIME/MEC, Measurement Laboratory, Italy, on 4-6 September 2013. The work of this symposium is reported in this volume. The scope of the symposium includes the main topics covered by the above Technical Committees: TC1 Education and Training in Measurement and Instrumentation TC7 Measurement Science TC13 Measurements in Biology and Medicine This is in keeping with the tradition set by the previous events of this well established series. There has been a special focus on measurement across physical and behavioural sciences, with the aim of highlighting the interdisciplinary character of measurement science and of promoting constructive interactions with scientists in other disciplines. The discussion was introduced by keynote lectures on measurement challenges in psychophysics, psychometrics and quantum physics. The symposium was attended by experts working in these areas from 18 countries, including USA, Australia and Japan, and provided a useful forum for them to share and exchange their work and ideas. In total over sixty papers are included in the volume, organised according to the presentation sessions. Each paper was independently peer-reviewed by two reviewers from a distinguished international panel. The Symposium was held in Genova, which was the European Capital of Culture in 2004, and took place in Palazzo Ducale, an important historical building whose construction started in the 13th century, and that has been the house of the Duke of Genova from the 14th century. Genova, whose name comes from the Latin word 'Janua' (meaning 'door', as January is the door month of the year), has been regarded over the centuries as a door connecting Europe with the different countries and cultures of the Mediterranean basin and thus was an appropriate site for an international symposium involving different and new scientific visions and approaches to

  4. Imaging of patent foramen ovale with 64-section multidetector CT.

    PubMed

    Saremi, Farhood; Channual, Stephanie; Raney, Aidan; Gurudevan, Swaminatha V; Narula, Jagat; Fowler, Steven; Abolhoda, Amir; Milliken, Jeffrey C

    2008-11-01

    To investigate the feasibility of 64-section multidetector computed tomography (CT) by using CT angiography (a) to demonstrate anatomic detail of the interatrial septum pertinent to the patent foramen ovale (PFO), and (b) to visually detect left-to-right PFO shunts and compare these findings in patients who also underwent transesophageal echocardiography (TEE). In this institutional review board-approved HIPAA-compliant study, electrocardiographically gated coronary CT angiograms in 264 patients (159 men, 105 women; mean age, 60 years) were reviewed for PFO morphologic features. The length and diameter of the opening of the PFO tunnel, presence of atrial septal aneurysm (ASA), and PFO shunts were evaluated. A left-to-right shunt was assigned a grade according to length of contrast agent jet (grade 1, 1 cm to 2 cm; grade 3, >2 cm). In addition, 23 patients who underwent both modalities were compared (Student t test and linear regression analysis). A difference with P < .05 was significant. A flap valve, seen in 101 (38.3%) patients, was patent at the entry into the right atrium (PFO) in 62 patients (61.4% of patients with flap valve, 23.5% of total patients). A left-to-right shunt was detected in 44 (16.7% of total) patients (grade 1, 61.4%; grade 2, 34.1%; grade 3, 4.5%). No shunt was seen in patients without a flap valve. Mean length of PFO tunnel was 7.1 mm in 44 patients with a shunt and 12.1 mm in 57 patients with a flap valve without a shunt (P < .0001). In patients with a tunnel length of 6 mm or shorter, 92.6% of the shunts were seen. ASA was seen in 11 (4.2%) patients; of these patients, a shunt was seen in seven (63.6%). In 23 patients who underwent CT angiography and TEE, both modalities showed a PFO shunt in seven. Multidetector CT provides detailed anatomic information about size, morphologic features, and shunt grade of the PFO. Shorter tunnel length and septal aneurysms are frequently associated with left-to-right shunts in

  5. SCDFT Study of High Tc Nitride Superconductors

    NASA Astrophysics Data System (ADS)

    Arita, R.

    Based on the density functional theory for superconductors (SCDFT), we study the pairing mechanism of the layered nitride superconductors, β-LixMNCl (M=Zr, Hf). Recently, it has been shown that SCDFT reproduces experimental superconducting transition temperatures (Tc) of conventional superconductors very accurately. Here we use SCDFT as a "litmus paper" to determine whether the system is a conventional or unconventional superconductor. We show that Tc estimated by SCDFT is less than half of the experimental Tc and its doping dependence is opposite to that observed in the experiments. The present result suggests that β- LixMNCl is not a Migdal-Eliashberg type superconductor.

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

    PubMed Central

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

    2015-01-01

    The interaction amongst papain-like cysteine-proteases (PLCP) and their substrates and inhibitors, such as cystatins, can be perceived as part of the molecular battlefield in plant-pathogen interaction. In cacao, four cystatins were identified and characterized by our group. We identified 448 proteases in cacao genome, whereof 134 were cysteine-proteases. We expressed in Escherichia coli a PLCP from cacao, named TcCYSPR04. Immunoblottings with anti-TcCYSPR04 exhibited protein increases during leaf development. Additional isoforms of TcCYSPR04 appeared in senescent leaves and cacao tissues infected by Moniliophthora perniciosa during the transition from the biotrophic to the saprophytic phase. TcCYSPR04 was induced in the apoplastic fluid of Catongo and TSH1188 cacao genotypes, susceptible and resistant to M. perniciosa, respectively, but greater intensity and additional isoforms were observed in TSH1188. The fungal protein MpNEP induced PLCP isoform expression in tobacco leaves, according to the cross reaction with anti-TcCYSPR04. Several protein isoforms were detected at 72 hours after treatment with MpNEP. We captured an active PLCP from cacao tissues, using a recombinant cacao cystatin immobilized in CNBr-Sepharose. Mass spectrometry showed that this protein corresponds to TcCYSPR04. A homology modeling was obtained for both proteins. In order to become active, TcCYSPR04 needs to lose its inhibitory domain. Molecular docking showed the physical-chemical complementarities of the interaction between the cacao enzyme and its inhibitor. We propose that TcCYSPR04 and its interactions with cacao cystatins are involved in the senescence and necrosis events related to witches’ broom symptoms. This molecular interaction may be the target for future interventions to control witches' broom disease. PMID:26641247

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

    PubMed

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

    2015-01-01

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

  8. Validation of an ergonomic method to withdraw [99mTc] radiopharmaceuticals.

    PubMed

    Blondeel-Gomes, Sandy; Marie, Solène; Fouque, Julien; Loyeau, Sabrina; Madar, Olivier; Lokiec, François

    2017-11-10

    The main objective of the present work was to ensure quality of radiopharmaceuticals syringes withdrawn with a "Spinal needle/obturator In-Stopper" system. Methods: Visual examinations and physicochemical tests are performed at T0 and T+4h for [ 99m Tc]albumin nanocolloid and T+7h for [ 99m Tc]eluate, [ 99m Tc] HydroxyMethylene DiPhosphonate and [ 99m Tc]Human Serum Albumin. Microbiological validation was performed according to European pharmacopoeia. Fingertip radiation exposure was evaluated to confirm the safety of the system. Results: Results show stable visual and physicochemical properties. The integrity of the connector was not affected after 30 punctures (no cores). No microbiological contamination was found on tested syringes. Conclusion: The system could be used 30 times. The stability of syringes drawing with this method is guaranteed up to 4 hours for [ 99m Tc]albumin nanocolloid and 7 hours for [ 99m Tc]eluate, [ 99m Tc]HydroxyMethylene DisPhosphonate and [ 99m Tc]Human serum albumin. Copyright © 2017 by the Society of Nuclear Medicine and Molecular Imaging, Inc.

  9. Comparison of 99mTc-UBI 29-41, 99mTc-Ciprofloxacin, 99mTc-Ciprofloxacin dithiocarbamate and 111In-biotin for targeting experimental Staphylococcus aureus and Escherichia coli foreign-body infections: an ex-vivo study.

    PubMed

    Auletta, Sveva; Baldoni, Daniela; Varani, Michela; Galli, Filippo; Hajar, Iman A; Duatti, Adriano; Ferro-Flores, Guillermina; Trampuz, Andrej; Signore, Alberto

    2017-08-28

    Diagnosis of implant-associated infection is challenging. Several radiopharmaceuticals have been described but direct comparisons are limited. Here we compared in vitro and in an animal model 99mTc-UBI, 99mTc-Ciprofloxacin, 99mTcN-CiproCS2 and 111In-DTPA-biotin for targeting E. coli (ATCC 25922) and S. aureus (ATCC 43335). Stability controls were performed with the labelled radiopharmaceuticals during 6 h in saline and serum. The in vitro binding to viable or killed bacteria was evaluated at 37 °C and 4 °C. For in vivo studies, Teflon cages were subcutaneously implanted in mice, followed by percutaneous infection. Biodistribution of i.v. injected radiolabelled radiopharmaceuticals were evaluated during 24 h in cages and dissected tissues. Labelling efficiency of all radiopharmaceuticals ranged between 94% and 98%, with high stability both in saline and in human serum. In vitro binding assays displayed a rapid but poor bacterial binding for all tested agents. Similar binding kinetic occurred also with heat-killed and ethanol-killed bacteria. In the tissue cage model, infection was detected at different time points: 99mTc-UBI and 99mTcN-CiproCS2 showed higher infected cage/sterile cage ratio at 24 h for both E. coli and S. aureus; 99mTc-Ciprofloxacin at 24 h for both E. coli and at 4 h for S. aureus; 111In-DTPA-biotin accumulates faster in both E. coli and S. aureus infected cages. 99mTc-UBI, 99mTcN-CiproCS2 showed poor in vitro binding but good in vivo binding to E. coli only. 111In-DTPA-biotin showed poor in vitro binding but good in vivo binding to S. aureus and poor to E. coli. 99mTc-Ciprofloxacin showed poor in vitro binding but good in vivo binding to all tested bacteria. The mechanism of accumulation in infected sites remains to be elucidated.

  10. Posterior semicircular canal dehiscence: value of VEMP and multidetector CT.

    PubMed

    Vanspauwen, R; Salembier, L; Van den Hauwe, L; Parizel, P; Wuyts, F L; Van de Heyning, P H

    2006-01-01

    To illustrate that posterior semicircular canal dehiscence can present similarly to superior semicircular canal dehiscence. The symptomatology initially presented as probable Menière's disease evolving into a mixed conductive hearing loss with a Carhart notch-type perceptive component suggestive of otosclerosis-type stapes fixation. A small hole stapedotomy resulted in a dead ear and a horizontal semicircular canal hypofunction. Recurrent incapacitating vertigo attacks developed. Vestibular evoked myogenic potential (VEMP) testing demonstrated intact vestibulocollic reflexes. Additional evaluation with high resolution multidetector computed tomography (MDCT) of the temporal bone showed a dehiscence of the left posterior semicircular canal. Besides superior semicircular canal dehiscence, posterior semicircular canal dehiscence has to be included in the differential diagnosis of atypical Menière's disease and/or low tone conductive hearing loss. The value of performing MDCT before otosclerosis-type surgery is stressed. VEMP might contribute to establishing the differential diagnosis.

  11. Quantitative Features of Liver Lesions, Lung Nodules, and Renal Stones at Multi-Detector Row CT Examinations: Dependency on Radiation Dose and Reconstruction Algorithm.

    PubMed

    Solomon, Justin; Mileto, Achille; Nelson, Rendon C; Roy Choudhury, Kingshuk; Samei, Ehsan

    2016-04-01

    To determine if radiation dose and reconstruction algorithm affect the computer-based extraction and analysis of quantitative imaging features in lung nodules, liver lesions, and renal stones at multi-detector row computed tomography (CT). Retrospective analysis of data from a prospective, multicenter, HIPAA-compliant, institutional review board-approved clinical trial was performed by extracting 23 quantitative imaging features (size, shape, attenuation, edge sharpness, pixel value distribution, and texture) of lesions on multi-detector row CT images of 20 adult patients (14 men, six women; mean age, 63 years; range, 38-72 years) referred for known or suspected focal liver lesions, lung nodules, or kidney stones. Data were acquired between September 2011 and April 2012. All multi-detector row CT scans were performed at two different radiation dose levels; images were reconstructed with filtered back projection, adaptive statistical iterative reconstruction, and model-based iterative reconstruction (MBIR) algorithms. A linear mixed-effects model was used to assess the effect of radiation dose and reconstruction algorithm on extracted features. Among the 23 imaging features assessed, radiation dose had a significant effect on five, three, and four of the features for liver lesions, lung nodules, and renal stones, respectively (P < .002 for all comparisons). Adaptive statistical iterative reconstruction had a significant effect on three, one, and one of the features for liver lesions, lung nodules, and renal stones, respectively (P < .002 for all comparisons). MBIR reconstruction had a significant effect on nine, 11, and 15 of the features for liver lesions, lung nodules, and renal stones, respectively (P < .002 for all comparisons). Of note, the measured size of lung nodules and renal stones with MBIR was significantly different than those for the other two algorithms (P < .002 for all comparisons). Although lesion texture was significantly affected by the

  12. Spectroscopic Properties of Tc(I) Tricarbonyl Species Relevant to the Hanford Tank Waste

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Levitskaia, Tatiana G.; Andersen, Amity; Chatterjee, Sayandev

    2015-12-04

    Technetium-99 (Tc) exists predominately in soluble forms in the liquid supernatant and salt cake fractions of the nuclear tank waste stored at the U.S. DOE Hanford Site. In the strongly alkaline environments prevalent in the tank waste, its dominant chemical form is pertechnetate (TcO4-, oxidation state +7). However, attempts to remove Tc from the Hanford tank waste using ion-exchange processes specific to TcO 4 - only met with limited success, particularly processing tank waste samples containing elevated concentrations of organic complexants. This suggests that a significant fraction of the soluble Tc can be present as non-pertechnetate low-valent Tc (oxidation statemore » < +7) (non-pertechnetate). The chemical identities of these non-pertechnetate species are poorly understood. Previous analysis of the SY-101 and SY-103 tank waste samples provided strong evidence that non-pertechnetate can be comprised of [Tc(CO) 3] + complexes containing Tc in oxidation state +1 (Lukens et al. 2004). During the last two years, our team has expanded this work and demonstrated that high-ionic-strength solutions typifying tank waste supernatants promote oxidative stability of the [Tc(CO) 3] + species (Rapko et al. 2013; Levitskaia et al. 2014). It also was observed that high-ionic-strength alkaline matrices stabilize Tc(VI) and potentially Tc(IV) oxidation states, particularly in presence organic chelators, suggesting that the relevant Tc compounds can serve as important redox intermediates facilitating the reduction of Tc(VII) to Tc(I). Designing strategies for effective Tc processing, including separation and immobilization, necessitates understanding the molecular structure of these non-pertechnetate species and their identification in the actual tank waste samples. To-date, only limited information exists regarding the nature and characterization of the Tc(I), Tc(IV), and Tc(VI) species. One objective of this project is to identify the form of non-pertechnetate in the

  13. High resolution multidetector CT aided tissue analysis and quantification of lung fibrosis

    NASA Astrophysics Data System (ADS)

    Zavaletta, Vanessa A.; Karwoski, Ronald A.; Bartholmai, Brian; Robb, Richard A.

    2006-03-01

    Idiopathic pulmonary fibrosis (IPF, also known as Idiopathic Usual Interstitial Pneumontis, pathologically) is a progressive diffuse lung disease which has a median survival rate of less than four years with a prevalence of 15-20/100,000 in the United States. Global function changes are measured by pulmonary function tests and the diagnosis and extent of pulmonary structural changes are typically assessed by acquiring two-dimensional high resolution CT (HRCT) images. The acquisition and analysis of volumetric high resolution Multi-Detector CT (MDCT) images with nearly isotropic pixels offers the potential to measure both lung function and structure. This paper presents a new approach to three dimensional lung image analysis and classification of normal and abnormal structures in lungs with IPF.

  14. Effective detection of the tumors causing osteomalacia using [Tc-99m]-HYNIC-octreotide (99mTc-HYNIC-TOC) whole body scan.

    PubMed

    Jing, Hongli; Li, Fang; Zhuang, Hongming; Wang, Zhenghua; Tian, Jian; Xing, Xiaoping; Jin, Jin; Zhong, Dingrong; Zhang, Jingjing

    2013-11-01

    Tumor-induced osteomalacia (TIO) is an endocrine disorder caused by tumors producing excessive fibroblast growth factor-23 (FGF-23). The causative tumors are generally small, slow-growing benign mesenchymal tumors. The only cure of the disease depends on resection of the tumors, which are extremely difficult to localize due to their small sizes and rare locations. Since these tumors are known to express somatostatin receptors, this research was undertaken to evaluate efficacy of [Tc-99m]-HYNIC-octreotide (99mTc-HYNIC-TOC) whole body imaging in this clinical setting Images of 99mTc-HYNIC-TOC scans and clinical chart from 183 patients with hypophosphatemia and clinically suspected TIO were retrospectively reviewed. The scan findings were compared to the results of histopathological examinations and clinical follow-ups. Among 183 patients, 72 were confirmed to have TIO while 103 patients were found to have other causes of hypophosphatemia. The possibility of TIO could not be either diagnosed or excluded in the remaining 8 patients. For analytical purposes, these 8 patients who could neither be diagnosed nor excluded as having TIO were regarded as having the disease, bringing the total of TIO patients to 80. The 99mTc-HYNIC-TOC scan identified 69 tumors in 80 patients with TIO, which rendered a sensitivity of 86.3% (69/80). 99mTc-HYNIC-TOC scintigraphy excluded 102 patients without TIO with a specificity of 99.1% (102/103). The overall accuracy of 99mTc-HYNIC-TOC whole body scan in the localization of tumors responsible for osteomalacia is 93.4% (171/183). Whole body 99mTc-HYNIC-TOC imaging is effective in the localization of occult tumors causing TIO. Copyright © 2013 Elsevier Ireland Ltd. All rights reserved.

  15. Role of CD8 Regulatory T Cells versus Tc1 and Tc17 Cells in the Development of Human Graft-versus-Host Disease.

    PubMed

    Gutiérrez-Hoya, Adriana; López-Santiago, Rubén; Vela-Ojeda, Jorge; Montiel-Cervantes, Laura; Rodríguez-Cortés, Octavio; Rosales-García, Víctor; Paredes-Cervantes, Vladimir; Flores-Mejía, Raúl; Sandoval-Borrego, Daniela; Moreno-Lafont, Martha

    2017-01-01

    CD8 + T cells that secrete proinflammatory cytokines play a central role in exacerbation of inflammation; however, a new subpopulation of CD8 regulatory T cells has recently been characterized. This study analyzes the prominent role of these different subpopulations in the development of graft-versus-host disease (GVHD). Samples from 8 healthy donors mobilized with Filgrastim® (G-CSF) and 18 patients who underwent allogeneic hematopoietic stem cell transplantation (HSCT) were evaluated by flow cytometry. Mobilization induced an increase in Tc1 ( p < 0.01), Th1 ( p < 0.001), Tc17 ( p < 0.05), and CD8 + IL-10 + cells ( p < 0.05), showing that G-CSF induces both pro- and anti-inflammatory profiles. Donor-patient correlation revealed a trend ( p = 0.06) toward the development of GVHD in patients who receive a high percentage of Tc1 cells. Patients with acute GVHD (aGVHD), either active or controlled, and patients without GVHD were evaluated; patients with active aGVHD had a higher percentage of Tc1 ( p < 0.01) and Tc17 ( p < 0.05) cells, as opposed to patients without GVHD in whom a higher percentage of CD8 Treg cells ( p < 0.01) was found. These findings indicate that the increase in Tc1 and Tc17 cells is associated with GVHD development, while regulatory CD8 T cells might have a protective role in this disease. These tests can be used to monitor and control GVHD.

  16. Role of CD8 Regulatory T Cells versus Tc1 and Tc17 Cells in the Development of Human Graft-versus-Host Disease

    PubMed Central

    Gutiérrez-Hoya, Adriana; López-Santiago, Rubén; Vela-Ojeda, Jorge; Montiel-Cervantes, Laura; Rodríguez-Cortés, Octavio; Rosales-García, Víctor; Flores-Mejía, Raúl; Sandoval-Borrego, Daniela

    2017-01-01

    CD8+ T cells that secrete proinflammatory cytokines play a central role in exacerbation of inflammation; however, a new subpopulation of CD8 regulatory T cells has recently been characterized. This study analyzes the prominent role of these different subpopulations in the development of graft-versus-host disease (GVHD). Samples from 8 healthy donors mobilized with Filgrastim® (G-CSF) and 18 patients who underwent allogeneic hematopoietic stem cell transplantation (HSCT) were evaluated by flow cytometry. Mobilization induced an increase in Tc1 (p < 0.01), Th1 (p < 0.001), Tc17 (p < 0.05), and CD8+IL-10+ cells (p < 0.05), showing that G-CSF induces both pro- and anti-inflammatory profiles. Donor-patient correlation revealed a trend (p = 0.06) toward the development of GVHD in patients who receive a high percentage of Tc1 cells. Patients with acute GVHD (aGVHD), either active or controlled, and patients without GVHD were evaluated; patients with active aGVHD had a higher percentage of Tc1 (p < 0.01) and Tc17 (p < 0.05) cells, as opposed to patients without GVHD in whom a higher percentage of CD8 Treg cells (p < 0.01) was found. These findings indicate that the increase in Tc1 and Tc17 cells is associated with GVHD development, while regulatory CD8 T cells might have a protective role in this disease. These tests can be used to monitor and control GVHD. PMID:28164135

  17. Collimated prompt gamma TOF measurements with multi-slit multi-detector configurations

    NASA Astrophysics Data System (ADS)

    Krimmer, J.; Chevallier, M.; Constanzo, J.; Dauvergne, D.; De Rydt, M.; Dedes, G.; Freud, N.; Henriquet, P.; La Tessa, C.; Létang, J. M.; Pleskač, R.; Pinto, M.; Ray, C.; Reithinger, V.; Richard, M. H.; Rinaldi, I.; Roellinghoff, F.; Schuy, C.; Testa, E.; Testa, M.

    2015-01-01

    Longitudinal prompt-gamma ray profiles have been measured with a multi-slit multi-detector configuration at a 75 MeV/u 13C beam and with a PMMA target. Selections in time-of-flight and energy have been applied in order to discriminate prompt-gamma rays produced in the target from background events. The ion ranges which have been extracted from each individual detector module agree amongst each other and are consistent with theoretical expectations. In a separate dedicated experiment with 200 MeV/u 12C ions the fraction of inter-detector scattering has been determined to be on the 10%-level via a combination of experimental results and simulations. At the same experiment different collimator configurations have been tested and the shielding properties of tungsten and lead for prompt-gamma rays have been measured.

  18. Controversies in imaging of hepatocellular carcinoma: multidetector CT (MDCT)

    PubMed Central

    Silverman, Paul M; Szklaruk, Janio

    2005-01-01

    Primary hepatocellular carcinoma (HCC) is a significant tumor worldwide and represents the most common primary hepatic neoplasm. Staging criteria are important for appreciation of timely work up of these neoplasms in contradiction with surgical colleagues. This article demonstrates the appearance of HCC on multiphasic, multidetector CT (MDCT) and relates these findings to current staging criteria. The variable appearance on different planes of contrast is critical to appreciate in staging this neoplasm. The hypervascular nature of the primary tumor makes MDCT and three-phase imaging a critical feature in the detection and characterization of this tumor. This is especially critical in the patients who are candidates for surgical resection. Additionally, MDCT has allowed arterial phase imaging to define the vascular supply of the tumor. An accurate representation of the size and number of lesions is critical in not only the initial staging but also the follow-up of hepatocellular carcinoma. The post-treatment features including the appearance post-surgically and after radiofrequency ablation can be well appreciated on MDCT. PMID:16361147

  19. The impact trajectory of asteroid 2008 TC3

    NASA Astrophysics Data System (ADS)

    Farnocchia, Davide; Jenniskens, Peter; Robertson, Darrel K.; Chesley, Steven R.; Dimare, Linda; Chodas, Paul W.

    2017-09-01

    The impact of asteroid 2008 TC3 was an unprecedented event-the first ever predicted impact of a near-Earth object. When it was first detected about 20 h before impact, 2008 TC3 was still farther away than the Moon. Once it was recognized as an impactor and announced as such, 2008 TC3 began to receive considerable attention from astronomical observers. Using the unprecedented dataset of nearly 900 astrometric observations and the latest observation debiasing and weighting techniques, we estimate the precise trajectory of 2008 TC3 and its impact ground track. At the entry point into the atmosphere, the 3-σ formal uncertainty in predicted position is an ellipse only 1.4 km × 0.15 km in size. The locations of the many meteorites recovered from the desert floor mark the asteroid's actual ground track and provide a unique opportunity to validate trajectory models. We find that the second-order zonal harmonics of the Earth gravity field moves the ground track by more than 1 km and the location along the ground track by more than 2 km, while non-zonal and higher order harmonics change the impact prediction by less than 20 m. The contribution of atmospheric drag to the trajectory of 2008 TC3 is similar to the numerical integration error level, a few meters, down to an altitude of 50 km. Integrating forward to lower altitudes and ignoring the break-up of 2008 TC3, atmospheric drag causes an along-track deviation that can be as large as a few kilometers at sea level.

  20. Unified electronic phase diagram for hole-doped high- Tc cuprates

    NASA Astrophysics Data System (ADS)

    Honma, T.; Hor, P. H.

    2008-05-01

    We have analyzed various characteristic temperatures and energies of hole-doped high- Tc cuprates as a function of a dimensionless hole-doping concentration (pu) . Entirely based on the experimental grounds, we construct a unified electronic phase diagram (UEPD), where three characteristic temperatures ( T∗ ’s) and their corresponding energies ( E∗ ’s) converge as pu increases in the underdoped regime. T∗ ’s and E∗ ’s merge together with the Tc curve and 3.5kBTc curve at pu˜1.1 in the overdoped regime, respectively. They finally go to zero at pu˜1.3 . The UEPD follows an asymmetric half-dome-shaped Tc curve, in which Tc appears at pu˜0.4 , reaches a maximum at pu˜1 , and rapidly goes to zero at pu˜1.3 . The asymmetric half-dome-shaped Tc curve is at odds with the well-known symmetric superconducting dome for La2-xSrxCuO4 (SrD-La214), in which two characteristic temperatures and energies converge as pu increases and merge together at pu˜1.6 , where Tc goes to zero. The UEPD clearly shows that pseudogap phase precedes and coexists with high temperature superconductivity in the underdoped and overdoped regimes, respectively. It is also clearly seen that the upper limit of high- Tc cuprate physics ends at a hole concentration that equals to 1.3 times the optimal doping concentration for almost all high- Tc cuprate materials and 1.6 times the optimal doping concentration for the SrD-La214. Our analysis strongly suggests that pseudogap is a precursor of high- Tc superconductivity, the observed quantum critical point inside the superconducting dome may be related to the end point of UEPD, and the normal state of the underdoped and overdoped high temperature superconductors cannot be regarded as a conventional Fermi liquid phase.

  1. Trypanosoma cruzi DTU TcII presents higher blood parasitism than DTU TcI in an experimental model of mixed infection.

    PubMed

    Sales-Campos, Helioswilton; Kappel, Henrique Borges; Andrade, Cristiane Pontes; Lima, Tiago Pereira; de Castilho, Alessandra; Giraldo, Luis Eduardo Ramirez; Lages-Silva, Eliane

    2015-09-01

    Trypanosoma cruzi (Tc), the causative agent of Chagas disease, affects millions of people worldwide. One of the major characteristics of T. cruzi is related to its heterogeneity due to the variability of its biological properties, parasite growth rates, infectivity, tissue tropism, morbidity and virulence among different isolates observed during experimental or human infection. Moreover, presence of mixed infections in the same host in endemic areas is a matter of study due to its impact on clinical manifestations and disease progression. In this study, we evaluated the biological behavior of two Tc I strains AQ1-7 (AQ) and MUTUM (MT) and one Tc II strain (JG) during the acute phase of infection, in unique and mixed infections. A patent blood parasitism was detected only in mice inoculated with JG strain . In addition blood parasitism parameters (peak and average blood parasitism) were positively associated when JG and AQ strains were combined. In contrast, a negative association was observed in the JG+MUTUM group. The predominance of TcII strain over TcI strains was highlighted using the LSSP-PCR technique, which was performed in samples from hemoculture. Thus, this study showed important biological differences between different T. cruzi strains and discrete typing units (DTUs) in acute phase. Finally, we observed that blood parasitism during early period of infection seems to be more related to DTU than to a specific strain.

  2. Microscopic model for the isotope effect in the high-Tc oxides

    NASA Astrophysics Data System (ADS)

    Kresin, V. Z.; Wolf, S. A.

    1994-02-01

    An unconventional microscopic mechanism relating Tc and the isotope substitution for the doped superconductors such as the high-Tc oxides is proposed. Strong nonadiabaticity, when it is impossible, strictly speaking, to separate fully the nuclear and electronic degrees of freedom, leads to a peculiar dependence of the carrier concentration n on the ionic mass M. This case corresponds, for example, to the isotopic substitution of the axial oxygen in YBa2Cu3O7-x. Because of the dependence of Tc on n, this leads to the dependence of Tc on M, that is to the isotope effect. The minimum value of the isotope coefficient corresponds to Tc=Tmaxc.

  3. Trapping volumetric measurement by multidetector CT in chronic obstructive pulmonary disease: Effect of CT threshold

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Wang, Xiaohua; Yuan, Huishu; Duan, Jianghui

    2013-08-15

    Purpose: The purpose of this study was to evaluate the effect of various computed tomography (CT) thresholds on trapping volumetric measurements by multidetector CT in chronic obstructive pulmonary disease (COPD).Methods: Twenty-three COPD patients were scanned with a 64-slice CT scanner in both the inspiratory and expiratory phase. CT thresholds of −950 Hu in inspiration and −950 to −890 Hu in expiration were used, after which trapping volumetric measurements were made using computer software. Trapping volume percentage (Vtrap%) under the different CT thresholds in the expiratory phase and below −950 Hu in the inspiratory phase was compared and correlated with lungmore » function.Results: Mean Vtrap% was similar under −930 Hu in the expiratory phase and below −950 Hu in the inspiratory phase, being 13.18 ± 9.66 and 13.95 ± 6.72 (both lungs), respectively; this difference was not significant (P= 0.240). Vtrap% under −950 Hu in the inspiratory phase and below the −950 to −890 Hu threshold in the expiratory phase was moderately negatively correlated with the ratio of forced expiratory volume in one second to forced vital capacity and the measured value of forced expiratory volume in one second as a percentage of the predicted value.Conclusions: Trapping volumetric measurement with multidetector CT is a promising method for the quantification of COPD. It is important to know the effect of various CT thresholds on trapping volumetric measurements.« less

  4. Research on tool wearing on milling of TC21 titanium alloy

    NASA Astrophysics Data System (ADS)

    Guilin, Liu

    2017-06-01

    Titanium alloys are used in aircraft widely, but the efficiency is a problem for machining titanium alloy. In this paper, the cutting experiment of TC21 titanium alloy was studied. Cutting parameters and test methods for TC21 titanium alloy were designed. The wear behavior of TC21 titanium alloy was studied based on analysis of orthogonal test results. It provides a group of cutting parameters for TC21 titanium alloy processing.

  5. Spectroscopic Characterization of Aqua [ fac-Tc(CO)3]+ Complexes at High Ionic Strength.

    PubMed

    Chatterjee, Sayandev; Hall, Gabriel B; Engelhard, Mark H; Du, Yingge; Washton, Nancy M; Lukens, Wayne W; Lee, Sungsik; Pearce, Carolyn I; Levitskaia, Tatiana G

    2018-06-18

    Understanding fundamental Tc chemistry is important to both the remediation of nuclear waste and the reprocessing of nuclear fuel; however, current knowledge of the electronic structure and spectral signatures of low-valent Tc compounds significantly lags behind the remainder of the d-block elements. In particular, identification and treatment of Tc speciation in legacy nuclear waste is challenging due to the lack of reference data especially for Tc compounds in the less common oxidation states (I-VI). In an effort to establish a spectroscopic library corresponding to the relevant conditions of extremely high ionic strength typical for the legacy nuclear waste, compounds with the general formula of [ fac-Tc(CO) 3 (OH 2 ) 3- n (OH) n ] 1- n (where n = 0-3) were examined by a range of spectroscopic techniques including 99 Tc/ 13 C NMR, IR, XPS, and XAS. In the series of monomeric aqua species, stepwise hydrolysis results in the increase of the Tc metal center electron density and corresponding progressive decrease of the Tc-C bond distances, Tc electron binding energies, and carbonyl stretching frequencies in the order [ fac-Tc(CO) 3 (OH 2 ) 3 ] + > [ fac-Tc(CO) 3 (OH 2 ) 2 (OH)] > [ fac-Tc(CO) 3 (OH 2 )(OH) 2 ] - . These results correlate with established trends of the 99 Tc upfield chemical shift and carbonyl 13 C downfield chemical shift. The lone exception is [ fac-Tc(CO) 3 (OH)] 4 which exhibits a comparatively low electron density at the metal center attributed to the μ 3 -bridging nature of the - OH ligands causing less σ-donation and no π-donation. This work also reports the first observations of these compounds by XPS and [ fac-Tc(CO) 3 Cl 3 ] 2- by XAS. The unique and distinguishable spectral features of the aqua [ fac-Tc(CO) 3 ] + complexes lay the foundation for their identification in the complex aqueous matrixes.

  6. Phenolic aminocarboxylate chelates of 99mTc as hepatobiliary agents.

    PubMed

    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.

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

    PubMed

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

    2014-05-01

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

  8. Pharmacokinetics of 99mTc-MAA- and 99mTc-HSA-Microspheres Used in Preradioembolization Dosimetry: Influence on the Liver-Lung Shunt.

    PubMed

    Grosser, Oliver S; Ruf, Juri; Kupitz, Dennis; Pethe, Annette; Ulrich, Gerhard; Genseke, Philipp; Mohnike, Konrad; Pech, Maciej; Richter, Wolf S; Ricke, Jens; Amthauer, Holger

    2016-06-01

    Perfusion scintigraphy using (99m)Tc-labeled albumin aggregates is mandatory before hepatic radioembolization with (90)Y-microspheres. As part of a prospective trial, the intrahepatic and intrapulmonary stability of 2 albumin compounds, (99m)Tc-MAA (macroaggregated serum albumin [MAA]) and (99m)Tc-HSA (human serum albumin [HSA]), was assessed. In 24 patients with metastatic colorectal cancer, biodistribution (liver, lung) and liver-lung shunt (LLS) of both tracers (12 patients each) were assessed by sequential planar scintigraphy (1, 5, and 24 h after injection). Liver uptake of both albumin compounds decreased differently. Although initial LLSs at 1 h after injection were similar in both groups, MAA-LLS increased significantly from 1 (3.9%) to 5 h (7.7%) and 24 h (9.9%) after injection, respectively. HSA-LLS did not change significantly (1 to 5 h), indicating a steady state of pulmonary and intrahepatic degradation. Compared with (99m)Tc-MAA-microspheres, (99m)Tc-HSA-microspheres are likely more resistant to degradation over time, allowing a reliable LLS determination even at later time points. © 2016 by the Society of Nuclear Medicine and Molecular Imaging, Inc.

  9. Polaron theory of high- Tc superconductors

    NASA Astrophysics Data System (ADS)

    Alexandrov, A. S.

    1989-05-01

    It is shown that the ordinary electron-phonon interaction can produce a high Tc as a result of the polaron narrowing of the band, which is not considered by the traditional theory of strong-coupling superconductors based on Migdal-Eliashberg equations, which are violated even in the range of moderate values λ ⪖1. Numerous experimental data are discussed which seem to favour a phonon-mediated attraction, polaron mass enhancement, narrow band and nonadiabatic motion of carriers and charged Bose-like excitations in high Tc metallic oxides.

  10. Targeted functional imaging of estrogen receptors with 99mTc-GAP-EDL.

    PubMed

    Takahashi, Nobukazu; Yang, David J; Kohanim, Saady; Oh, Chang-Sok; Yu, Dong-Fang; Azhdarinia, Ali; Kurihara, Hiroaki; Zhang, Xiaochun; Chang, Joe Y; Kim, E Edmund

    2007-03-01

    To evaluate the feasibility of using (99m)Tc-glutamate peptide-estradiol in functional imaging of estrogen receptor-positive [ER(+)] diseases. 3-Aminoethyl estradiol (EDL) was conjugated to glutamate peptide (GAP) to yield GAP-EDL. Cellular uptake studies of (99m)Tc-GAP-EDL were conducted in ER(+) cell lines (MCF-7, 13762 and T47D). To demonstrate whether GAP-EDL increases MAP kinase activation, Western blot analysis of GAP-EDL was performed in 13762 cells. Biodistribution was conducted in nine rats with 13762 breast tumors at 0.5-4 h. Each rat was administered (99m)Tc-GAP-EDL. Two animal models (rats and rabbits) were created to ascertain whether tumor uptake of (99m)Tc-GAP-EDL was via an ER-mediated process. In the tumor model, breast tumor-bearing rats were pretreated with diethylstilbestrol (DES) 1 h prior to receiving (99m)Tc-GAP-EDL. In the endometriosis model, part of the rabbit uterine tissue was dissected and grafted to the peritoneal wall. The rabbit was administered with (99m)Tc-GAP-EDL. There was a 10-40% reduction in uptake of (99m)Tc-GAP-EDL in cells treated with DES or tamoxifen compared with untreated cells. Western blot analysis showed an ERK1/2 phosphorylation process with GAP-EDL. Biodistribution studies showed that tumor uptake and tumor-to-muscle count density ratio in (99m)Tc-GAP-EDL groups were significantly higher than those in (99m)Tc-GAP groups at 4 h. Among (99m)Tc-GAP-EDL groups, region of interest analysis of images showed that tumor-to muscle ratios were decreased in blocking groups. In the endometriosis model, the grafted uterine tissue could be visualized by (99m)Tc-GAP-EDL. Cellular or tumor uptake of (99m)Tc-GAP-EDL occurs via an ER-mediated process. (99m)Tc-GAP-EDL is a useful agent for imaging functional ER(+) disease.

  11. System Concepts for Children via LEGO TC logo.

    ERIC Educational Resources Information Center

    Gorbunov, Andrei L.

    1994-01-01

    Discussion of knowledge constructionism focuses on LEGO TC logo, a program that permits control of LEGO toys by means of a computer. A project for 9- and 10-year-old students that uses LEGO TC logo to develop concepts related to automatic control systems is explained. (three references) (LRW)

  12. Evaluation of prosthetic valve thrombosis by 64-row multi-detector computed tomography. .

    PubMed

    Tarzia, Vincenzo; Bortolussi, Giacomo; Rubino, Maurizio; Gallo, Michele; Bottio, Tomaso; Gerosa, Gino

    2015-03-01

    Multi-detector computed tomography (MDCT), combined with retrospective electrocardiographic gating, permits cardiac imaging with high accuracy. Recent advances in MDCT have seemed to respond adequately to the need for a non-invasive and reliable assessment of the coronary artery lumen. Two patients with prosthetic aortic valves (one bioprosthetic, one mechanical) presented at the authors' institution with dyspnea and syncopal episodes. MDCT was performed to evaluate thrombus characteristics and exclude coronary artery disease (CAD). Based on the MDCT coronary artery assessment, neither patient underwent preoperative invasive coronary angiography, abolishing the risk of any iatrogenic thrombus fragmentation and subsequent embolization. One patient underwent surgical treatment without complications, while medical therapy was successful in the other case. MDCT can be used for the accurate imaging of thrombi on prosthetic aortic valves, and to correctly assess possible CAD.

  13. Systematic XAS study on the reduction and uptake of Tc by magnetite and mackinawite.

    PubMed

    Yalçıntaş, Ezgi; Scheinost, Andreas C; Gaona, Xavier; Altmaier, Marcus

    2016-11-28

    The mechanisms for the reduction and uptake of Tc by magnetite (Fe 3 O 4 ) and mackinawite (FeS) are investigated using X-ray absorption spectroscopy (XANES and EXAFS), in combination with thermodynamic calculations of the Tc/Fe systems and accurate characterization of the solution properties (pH m , pe, [Tc]). Batch sorption experiments were performed under strictly anoxic conditions using freshly prepared magnetite and mackinawite in 0.1 M NaCl solutions with varying initial Tc(vii) concentrations (2 × 10 -5 and 2 × 10 -4 M) and Tc loadings (400-900 ppm). XANES confirms the complete reduction of Tc(vii) to Tc(iv) in all investigated systems, as predicted from experimental (pH m + pe) measurements and thermodynamic calculations. Two Tc endmember species are identified by EXAFS in the magnetite system, Tc substituting for Fe in the magnetite structure and Tc-Tc dimers sorbed to the magnetite {111} faces through a triple bond. The sorption endmember is favoured at higher [Tc], whereas incorporation prevails at low [Tc] and less alkaline pH conditions. The key role of pH in the uptake mechanism is interpreted in terms of magnetite solubility, with higher [Fe] and greater recrystallization rates occurring at lower pH values. A TcS x -like phase is predominant in all investigated mackinawite systems, although the contribution of up to 20% of TcO 2 ·xH 2 O(s) (likely as surface precipitate) is observed for the highest investigated loadings (900 ppm). These results provide key inputs for an accurate mechanistic interpretation of the Tc uptake by magnetite and mackinawite, so far controversially discussed in the literature, and represent a highly relevant contribution to the investigation of Tc retention processes in the context of nuclear waste disposal.

  14. Impurities in Tc-99m radiopharmaceutical solution obtained from Mo-100 in cyclotron.

    PubMed

    Tymiński, Zbigniew; Saganowski, Paweł; Kołakowska, Ewa; Listkowska, Anna; Ziemek, Tomasz; Cacko, Daniel; Dziel, Tomasz

    2018-04-01

    The gamma emitting impurities in 99m Tc solution obtained from enriched molybdenum 100 Mo metallic target after its irradiation in a cyclotron were measured using a high-purity germanium (HPGe) detector. The radioactivity range of tested samples of 99m Tc was rather low, in the range from 0.34 to 2.39 MBq, thus creating a challenge to investigate the standard measurement HPGe system for impurity detection and quantification. In the process of 99m Tc separation from irradiated target the AnaLig® Tc-02 resin, Dionex H + and Alumina A columns were used. Fractions of eluates from various steps of separation process were taken and measured for radionuclidic purity. The overall measurement sensitivity of gamma emitters in terms of minimum detectable activity (MDA) was found at the level of 14-70Bq with emission lines in range of 36 - 1836keV resulting in impurity content range of 6.7 × 10 -4 to 3.4 × 10 -3 % for 93 Tc, 93m Tc, 94 Tc, 94m Tc, 95 Tc, 95m Tc, 96 Tc 96 Nb, 97 Nb, 99 Mo contaminants and 9.4 × 10 -3 % for 97m Tc. The usefulness of the chosen measurement conditions and the method applied to testing the potential contaminators was proved by reaching satisfactory results of MDAs less than the criteria of impurity concentration of all nuclides specified in the European Pharmacopoeia. Copyright © 2017 Elsevier Ltd. All rights reserved.

  15. Improving the Strength of the ZrC-SiC and TC4 Brazed Joint Through Fabricating Graded Double-Layered Composite Structure on TC4 Surface

    NASA Astrophysics Data System (ADS)

    Shi, J. M.; Zhang, L. X.; Chang, Q.; Sun, Z.; Feng, J. C.; Ma, N.

    2018-06-01

    In order to improve the ZrC-SiC ceramic and TC4 brazed joint property, graded double-layered SiC particles (SiCp)-reinforced TC4-based composite structure (named as GLS for convenience) was designed to relieve the residual stress in the joint. The GLS was successfully fabricated on TC4 substrate by double-layered laser deposition technology before the brazing process. The investigation of the GLS shows that the volume fraction of SiCp in the two composite layers was graded (20 and 39 vol pct, respectively). Ti5Si3 and TiC phases formed in the GLS due to the reaction of SiCp and TC4. The laser power-II (the laser power for the second deposition layer) affected the microstructure of the GLS significantly. Increasing the laser power-II would promote the reaction between the SiCp and TC4. But the high laser power-II made the layer I remelt completely and the two layers became homogeneous rather than graded structure. In the ZrC-SiC and TC4 brazed joint, the CTE (coefficient of thermal expansion) was graded from the TC4 to the ZrC-SiC due to the GLS, and the strength of the joint with the GLS (91 MPa) was higher than that without the GLS (43 MPa).

  16. 99mTc-MAA/ 90Y-Bremsstrahlung SPECT/CT after simultaneous Tc-MAA/90Y-microsphere injection for immediate treatment monitoring and further therapy planning for radioembolization.

    PubMed

    Ahmadzadehfar, Hojjat; Sabet, Amir; Muckle, Marianne; Wilhelm, Kai; Reichmann, Karl; Biersack, Hans-Jürgen; Ezziddin, Samer

    2011-07-01

    An angiographic evaluation combined with (99m)Tc-macroaggregated albumin (Tc-MAA) scanning should precede the treatment of any selected candidates for radioembolization (RE) of the liver. If the tumours in one liver lobe have not been targeted in the test angiogram, it should be repeated. However, in a few cases treatment of one liver lobe or at least some segments is safe and feasible and performing a repeated test angiogram with Tc-MAA (Re-MAA) in a separate session leads to more radiation exposure and could be time consuming. Our aim was to evaluate the feasibility of concurrent RE of a part of the liver and therapy planning for another region by simultaneous injection of the Tc-MAA and (90)Y-microspheres in two different locations in the therapy session. Tc-MAA and bremsstrahlung (BS) single photon emission computed tomography (SPECT)/CT were performed separately in an effort to distinguish between the distributions of these two different radiopharmaceuticals. RE was combined with a simultaneous second test angiogram of another lobe or segments in the same session in six patients [44-70 years; five women (83%)]. Five patients suffered from colorectal carcinoma (CRC) and one from ovarian cancer. Tc-MAA and BS SPECT/CT were performed for all cases. Post-therapeutic Tc-MAA SPECT/CT showed in all patients only the distribution of Tc-MAA without any detectable BS. Evaluation of (90)Y-microsphere distribution was not always possible in the post-therapeutic BS scan performed 24 h later due to remaining Tc-MAA radiation. However, scans performed at 48 h post-intervention no longer showed any Tc-MAA "contamination". Combining RE and Re-MAA is feasible in appropriately selected patients.

  17. Supine lung clearance of Tc-99m DTPA and HMPAO aerosols

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Chia-Hung Kao; Hui-Tzu Lin; Shu-Ling Yu

    1995-07-01

    The speed of Tc-99m DTPA/HMPAO radioaerosol clearance from the lungs that is represented as a slope from lungs to blood was measured in 23 male normal controls using commercial lung radioaerosol delivery units in the supine position in order to avoid the influences of gravity. The right lung was selected and three regions of interest were created for equal subdivisions of the upper, middle, and lower third. The results show that the clearance of Tc-99m DTPA/HMPAO aerosols in the upper lung is lowest. The difference between upper and lower lungs for Tc-99m DTPA/HMPAO aerosol clearances are significant. The clearance ofmore » Tc-99m DTPA aerosols was significantly faster than those of Tc-99m HMPAO in any region. The authors conclude that, although the effect of gravity disappears in the supine position in our study, the differences of aerosol clearance in different regions are still significant. Lipophilic Tc-99m HMPAO aerosols were slower than those of hydrophilic Tc-99m DTPA, which suggests there are at least two different mechanisms. 22 refs., 2 figs., 1 tab.« less

  18. Recent achievements in Tc-99m radiopharmaceutical direct production by medical cyclotrons.

    PubMed

    Boschi, Alessandra; Martini, Petra; Pasquali, Micol; Uccelli, Licia

    2017-09-01

    99m Tc is the most commonly used radionuclide in the field of diagnostic imaging, a noninvasive method intended to diagnose a disease, assess the disease state and monitor the effects of treatments. Annually, the use of 99m Tc, covers about 85% of nuclear medicine applications. This isotope releases gamma rays at about the same wavelength as conventional X-ray diagnostic equipment, and owing to its short half-life (t ½  = 6 h) is ideal for diagnostic nuclear imaging. A patient can be injected with a small amount of 99m Tc and within 24 h almost 94% of the injected radionuclide would have decayed and left the body, limiting the patient's radiation exposure. 99m Tc is usually supplied to hospitals through a 99 Mo/ 99m Tc radionuclide generator system where it is produced from the β decay of the parent nuclide 99 Mo (t ½  = 66 h), which is produced in nuclear reactors via neutron fission. Recently, the interruption of the global supply chain of reactor-produced 99 Mo, has forced the scientific community to investigate alternative production routes for 99m Tc. One solution was to consider cyclotron-based methods as potential replacement of reactor-based technology and the nuclear reaction 100 Mo(p,2n) 99m Tc emerged as the most worthwhile approach. This review reports some achievements about 99m Tc produced by medical cyclotrons. In particular, the available technologies for target design, the most efficient extraction and separation procedure developed for the purification of 99m Tc from the irradiated targets, the preparation of high purity 99m Tc radiopharmaceuticals and the first clinical studies carried out with cyclotron produced 99m Tc are described.

  19. Sex differences in aortic valve calcification measured by multidetector computed tomography in aortic stenosis.

    PubMed

    Aggarwal, Shivani R; Clavel, Marie-Annick; Messika-Zeitoun, David; Cueff, Caroline; Malouf, Joseph; Araoz, Philip A; Mankad, Rekha; Michelena, Hector; Vahanian, Alec; Enriquez-Sarano, Maurice

    2013-01-01

    Aortic valve calcification (AVC) is the intrinsic mechanism of valvular obstruction leading to aortic stenosis (AS) and is measurable by multidetector computed tomography. The link between sex and AS is controversial and that with AVC is unknown. We prospectively performed multidetector computed tomography in 665 patients with AS (aortic valve area, 1.05±0.35 cm(2); mean gradient, 39±19 mm Hg) to measure AVC and to assess the impact of sex on the AVC-AS severity link in men and women. AS severity was comparable between women and men (peak aortic jet velocity: 4.05±0.99 versus 3.93±0.91 m/s, P=0.11; aortic valve area index: 0.55±0.20 versus 0.56±0.18 cm(2)/m(2); P=0.46). Conversely, AVC load was lower in women versus men (1703±1321 versus 2694±1628 arbitrary units; P<0.0001) even after adjustment for their smaller body surface area or aortic annular area (both P<0.0001). Thus, odds of high-AVC load were much greater in men than in women (odds ratio, 5.07; P<0.0001). Although AVC showed good associations with hemodynamic AS severity in men and women (all r>0.67; P<0.0001), for any level of AS severity measured by peak aortic jet velocity or aortic valve area index, AVC load, absolute or indexed, was higher in men versus women (all P≤0.01). In this large AS population, women incurred similar AS severity than men for lower AVC loads, even after indexing for their smaller body size. Hence, the relationship between valvular calcification process and AS severity differs in women and men, warranting further pathophysiological inquiry. For AS severity diagnostic purposes, interpretation of AVC load should be different in men and in women.

  20. Comparison of LDPI to SPECT perfusion imaging using (99m)Tc-sestamibi and (99m)Tc-pyrophosphate in a murine ischemic hind limb model of neovascularization.

    PubMed

    Hendrikx, Geert; Vries, Mark H; Bauwens, Matthias; De Saint-Hubert, Marijke; Wagenaar, Allard; Guillaume, Joël; Boonen, Levinia; Post, Mark J; Mottaghy, Felix M

    2016-12-01

    We aimed to determine the accuracy of laser Doppler perfusion imaging (LDPI) in an animal model for hind limb ischemia. We used a murine (C57Bl/6 mice) ischemic hind limb model in which we compared LDPI with the clinically used (99m)Tc-sestamibi SPECT perfusion imaging (n = 7). In addition, we used the SPECT tracer (99m)Tc-pyrophosphate ((99m)Tc-PyP) to image muscular damage (n = 6). LDPI indicated a quick and prominent decrease in perfusion immediately after ligation, subsequently recovering to 21.9 and 25.2 % 14 days later in the (99m)Tc-sestamibi and (99m)Tc-PyP group, respectively. (99m)Tc-sestamibi SPECT scans also showed a quick decrease in perfusion. However, nearly full recovery was reached 7 days post ligation. Muscular damage, indicated by the uptake of (99m)Tc-PyP, was highest at day 3 and recovered to baseline levels at day 14 post ligation. Postmortem histology supported these findings, as a significantly increased collateral diameter was found 7 and 14 days after ligation and peak macrophage infiltration and TUNEL positivity was found on day 3 after ligation. Here, we indicate that LDPI strongly underestimates perfusion recovery in a hind limb model for profound ischemia.

  1. Direct production of 99mTc using a small medical cyclotron

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Lapi, Suzanne

    This project describes an investigation towards the production of 99mTc with a small medical cyclotron. This endeavor addresses the current urgent problem of availability of 99mTc due to the ongoing production reactor failures and the upcoming Canadian reactor shut down. Currently, 99mTc is produced via nuclear fission using highly enriched uranium which is a concern due to nuclear proliferation risks. In addition to this, the United States is dependent solely on currently unreliable foreign sources of this important medical isotope. Clearly, a need exists to probe alternative production routes of 99mTc. In the first year, this project measured cross-sections andmore » production yields of potential pathways to 99mTc and associated radionuclidic impurities produced via these pathways using a small 15 MeV medical cyclotron. During the second and third years target systems for the production of 99mTc via the most promising reaction routes were developed and separation techniques for the isolation of 99mTc from the irradiated target material will be investigated. Systems for the recycling of the enriched target isotopes as well as automated target processing systems were examined in years four and five. This project has the potential to alleviate some of the current crisis in the medical community by developing a technique to produce 99mTc on location at a university hospital. This technology will be applicable at many other sites in the United States as many other similar, low energy (<20 MeV) cyclotrons (currently used for a few hours per day for the production of [ 18F]fluorodeoxyglucose) are available for production of 99mTc though this method, thus leading to job creation and preservation.« less

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

    PubMed

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

    1993-03-01

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

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

    NASA Astrophysics Data System (ADS)

    Asmussen, R. Matthew; Neeway, James J.; Lawter, Amanda R.; Levitskaia, Tatiana G.; Lukens, Wayne W.; Qafoku, Nikolla P.

    2016-11-01

    At the U.S. Department of Energy Hanford Site, Tc-99 is a component of low-activity waste (LAW) fractions of the nuclear tank waste and removal of Tc from LAW streams would greatly benefit the site remediation process. In this study, we investigated the removal of Tc(VII), as pertechnetate, from deionized water (DIW) and a LAW simulant through batch sorption testing and solid phase characterization using tin (II) apatite (Sn-A) and SnCl2. Sn-A showed higher levels of Tc removal from both DIW and LAW simulant. Scanning electron microscopy/energy dispersive X-ray spectroscopy (SEM/XEDS) and X-ray absorption spectroscopy (XAS) of reacted Sn-A in DIW showed that TcO4- is reduced to Tc(IV) on the Sn-A surface. The performance of Sn-A in the LAW simulant was lowered due to a combined effect of the high alkalinity, which lead to an increased dissolution of Sn from the Sn-A, and a preference for the reduction of Cr(VI).

  4. Statistical iterative reconstruction for streak artefact reduction when using multidetector CT to image the dento-alveolar structures.

    PubMed

    Dong, J; Hayakawa, Y; Kober, C

    2014-01-01

    When metallic prosthetic appliances and dental fillings exist in the oral cavity, the appearance of metal-induced streak artefacts is not avoidable in CT images. The aim of this study was to develop a method for artefact reduction using the statistical reconstruction on multidetector row CT images. Adjacent CT images often depict similar anatomical structures. Therefore, reconstructed images with weak artefacts were attempted using projection data of an artefact-free image in a neighbouring thin slice. Images with moderate and strong artefacts were continuously processed in sequence by successive iterative restoration where the projection data was generated from the adjacent reconstructed slice. First, the basic maximum likelihood-expectation maximization algorithm was applied. Next, the ordered subset-expectation maximization algorithm was examined. Alternatively, a small region of interest setting was designated. Finally, the general purpose graphic processing unit machine was applied in both situations. The algorithms reduced the metal-induced streak artefacts on multidetector row CT images when the sequential processing method was applied. The ordered subset-expectation maximization and small region of interest reduced the processing duration without apparent detriments. A general-purpose graphic processing unit realized the high performance. A statistical reconstruction method was applied for the streak artefact reduction. The alternative algorithms applied were effective. Both software and hardware tools, such as ordered subset-expectation maximization, small region of interest and general-purpose graphic processing unit achieved fast artefact correction.

  5. Comparative analysis of 99mTc-depreotide and 99mTc-EDDA/HYNIC-TOC thorax scintigrams acquired for the purpose of differential diagnosis of solitary pulmonary nodules.

    PubMed

    Płachcińska, Anna; Mikołajczak, Renata; Kozak, Józef; Rzeszutek, Katarzyna; Kuśmierek, Jacek

    2006-01-01

    Aiming at comparison of diagnostic efficacy of 2 radiopharmaceuticals: 99mTc-depreotide (Neospect, Amersham) and 99mTc-EDDA/HYNIC-Tyr3-octreotide (Tektrotyd, Polatom), in differentiation between malignant and benign etiology of solitary pulmonary nodules (SPNs), radionuclide studies with 2 radiotracers were performed in 18 patients. For both radiopharmaceuticals the same acquisition and processing protocols were applied. Studies were acquired with SPECT technique, after administration of 740 MBq of activity. Scintigrams were assessed visually, as: positive (+), equivocal (+/-) and negative (-). Additionally, uptake intensity of both radiotracers in nodules was assessed semiquantitatively, using a tumour-to-background ratio. Verification of scintigraphic results was based in 14 cases upon a pathological examination of tumour samples (histopathology) and in the remaining 4 - on clinical observation and bacteriological studies. Normal scintigrams obtained with both radiopharmaceuticals differed significantly. 99mTc-depreotide was markedly accumulated in spine, sternum, ribs and lungs (mean lung/heart ratio = 2.2). This accumulation was not observed on 99mTc- -EDDA/HYNIC-TOC scintigrams (mean lung/heart ratio = 0.7). In 6 patients a malignant etiology--lung cancer--was revealed (5--adenocarcinoma, 1--squamous cell) and the other 12 cases turned out to be benign (4 hamartomas, 3 tuberculomas, a tuberculous infiltrate, an alien body with inflammatory reaction, a hyperplasia of lymphatic tissue and 2 cases of unknown etiology, from which one had a stable size and the other resolved during a 6 month observation period). In all 6 cases of lung cancer positive results were obtained with both tracers. Moreover, in 2 patients metastases in mediastinum could be observed on scintigrams obtained with both radiopharmaceuticals. From among 12 cases of benign etiology 6 99mTc-depreotide scintigrams were true negative, 1--equivocal and 5--false positive, whereas 6 99mTc

  6. Meissner motor using high-Tc ceramic superconductors

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Takeoka, A.; Ishikawa, A.; Suzuki, M.

    1989-03-01

    The authors developed a brand new superconducting motor using high-Tc ceramic superconductors for the first time. This motor utilizes the repulsive force caused by the Meissner effect, which appears below Tc and disappears above that, and is therefore referred to as the Meissner Motor. The motor rotated at a maximum speed of 40 rpm. Though the repulsive force to drive the motor increased with the decrease of temperature or the increase of the gradient magnetic field, it was only about 1.1 gf/g at 77 K in 3500 G/cm. The motor has a maximum torque of 5.0 gf-cm theoretically, but actuallymore » had a torque below 0.66 gf-cm, because it took some time to be cooled below Tc. The rotating speed of the motor was limited by heating ability and its torque was limited by cooling ability.« less

  7. Dose calibrator linearity test: 99mTc versus 18F radioisotopes*

    PubMed Central

    Willegaignon, José; Sapienza, Marcelo Tatit; Coura-Filho, George Barberio; Garcez, Alexandre Teles; Alves, Carlos Eduardo Gonzalez Ribeiro; Cardona, Marissa Anabel Rivera; Gutterres, Ricardo Fraga; Buchpiguel, Carlos Alberto

    2015-01-01

    Objective The present study was aimed at evaluating the viability of replacing 18F with 99mTc in dose calibrator linearity testing. Materials and Methods The test was performed with sources of 99mTc (62 GBq) and 18F (12 GBq) whose activities were measured up to values lower than 1 MBq. Ratios and deviations between experimental and theoretical 99mTc and 18F sources activities were calculated and subsequently compared. Results Mean deviations between experimental and theoretical 99mTc and 18F sources activities were 0.56 (± 1.79)% and 0.92 (± 1.19)%, respectively. The mean ratio between activities indicated by the device for the 99mTc source as measured with the equipment pre-calibrated to measure 99mTc and 18F was 3.42 (± 0.06), and for the 18F source this ratio was 3.39 (± 0.05), values considered constant over the measurement time. Conclusion The results of the linearity test using 99mTc were compatible with those obtained with the 18F 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 18F acquisition suggest 99mTc as the element of choice to perform dose calibrator linearity tests in centers that use 18F, without any detriment to the procedure as well as to the quality of the nuclear medicine service. PMID:25798005

  8. /sup 99m/Tc-fibrinogen scanning in adult respiratory distress syndrome

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Quinn, D.A.; Carvalho, A.C.; Geller, E.

    1987-01-01

    Fibrin is often seen occluding the lung vessels of patients dying from ARDS and is surrounded by regions of lung necrosis. To learn if we could observe increased or focal fibrin deposition and assess the kinetics of plasma fibrinogen turnover during severe acute respiratory failure, we injected technetium 99m-labeled human purified fibrinogen (Tc-HF) and used gamma camera scanning for as long as 12 h in 13 sequential patients as soon as possible after ICU admission. The fibrinogen uptake rates were determined by calculating the lung:heart radioactivity ratios at each time point. Slopes of the lung:heart ratio versus time were comparedmore » between ARDS and mild acute respiratory failure (ARF). The slope of the lung:heart Tc-HF ratio of the 9 patients with ARDS (2.9 +/- 0.4 units) was markedly higher (p less than 0.02) than the slope of the 4 patients with mild ARF (1.1 +/- 0.4) and the 3 patients studied 5 to 9 months after recovery from respiratory failure (0.7 +/- 0.07). In the 1 patient with ARDS and the 2 patients with mild ARF studied both during acute lung injury and after recovery, the lung:heart Tc-HF ratio had decreased at recovery. To compare the pulmonary uptake of Tc-HF to /sup 99m/Tc-labeled human serum albumin (Tc-HSA), 5 patients were injected with 10 mCi of Tc-HSA, and scanning of the thorax was performed with a similar sequential imaging protocol 24 h after conclusion of the Tc-HF study.« less

  9. Validation of a kinetic model for receptor-mediated uptake of Tc-99m-galactosyl-neoglycoalbumin (Tc-NGA)

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Vera, D.R.; Krohn, K.A.; Woodle, E.S.

    1984-01-01

    Tc-NGA is a receptor-binding radiopharmaceutical which localizes specifically to the liver. The rate of uptake depends upon: 1) Tc-NGA-receptor affinity, k/sub b/, 2) molar dose, L/sub e/(O), and 3) hepatic blood flow, Q. The authors have proposed a kinetic model which describes hepatic uptake in terms of measurable physiochemical quantities: Q, k/sub b/, R, V/sub e/, V/sub h/ (systemic and liver blood volumes), and V/sub r/ (liver plasma volume). Computer simulations were compared to kinetic data (ROIs: precordium and liver, 420 data pts) resulting from injection into pigs (n=12) of Tc-NGAs of differing k/sub b/(0.6,1.2,1.8 x 10/sup 5/ M/sup -1/sec/supmore » -1/). Each pig was studied twice using different molar doses (0.5 - 10. x 10/sup -8/mole). Measurements of V/sub e/ (Tc-RBCs) and Q (indocyanine green extraction) were obtained during each study. Weights of excised livers were used to calculate V/sub h/ and r. With exception of the low-dose, low-affinity studies, all data was fit to within a reduced chi-square of 3 by adjustment of 1/sub e/, 1/sub h/, c, ..cap alpha../sub m/ and the sigmas. The authors conclude that this model is a valid description of a receptor-binding process, however competition by endogenous ligand may prevent its use at low molar doses of low-k/sub b/ NGA.« less

  10. 99 Tc NMR determination of the oxygen isotope content in 18 O-enriched water.

    PubMed

    Tarasov, Valerii P; Kirakosyan, Gayana А; German, Konstantin E

    2018-03-01

    99 Tc NMR has been suggested as an original method of evaluating the content of oxygen isotopes in oxygen-18-enriched water, a precursor for the production of radioisotope fluorine-18 used in positron emission tomography. To this end, solutions of NH 4 TcO 4 or NaTcO 4 (up to 0.28 mol/L) with natural abundance of oxygen isotopes in virgin or recycled 18 O-enriched water have been studied by 99 Tc NMR. The method is based on 16 O/ 17 O/ 18 O intrinsic isotope effects in the 99 Tc NMR chemical shifts, and the statistical distribution of oxygen isotopes in the coordination sphere of TcO 4 - and makes it possible to quantify the composition of enriched water by measuring the relative intensities of the 99 Tc NMR signals of the Tc 16 O 4-n 18 O n - isotopologues. Because the oxygen exchange between TcO 4 - and enriched water in neutral and alkaline solutions is characterized by slow kinetics, gaseous HCl was bubbled through a solution for a few seconds to achieve the equilibrium distribution of oxygen isotopes in the Tc coordination sphere without distortion of the oxygen composition of the water. Pertechnetate ion was selected as a probe due to its high stability in solutions and the significant 99 Tc NMR shift induced by a single 16 O→ 18 O substitution (-0.43 ± 0.01 ppm) in TcO 4 - and spin coupling constant 1 J( 99 Tc- 17 O) (131.46 Hz) favourable for the observation of individual signals of Tc 16 O 4-n 18 O n - isotopologues. Copyright © 2017 John Wiley & Sons, Ltd.

  11. Magnetically-related properties of bismuth containing high Tc superconductors

    NASA Astrophysics Data System (ADS)

    Vezzoli, Gary C.; Chen, M. F.; Craver, F.; Safari, A.; Moon, B. M.; Lalevic, B.; Burke, Terence; Shoga, M.

    1990-08-01

    The effect of magnetic fields to 15 T on electrical resistance has been measured for the BiSrCaCuO superconductor at precise temperatures during the transition to the superconducting state from pre-onset conditions to essentially zero resistance conditions. The results show that the temperature at which the magnetic field causes a divergence in the resistance versus 1000/ T curve is approximately the same temperature as the value at which, during cooling, the positive Hall coefficient begins its abrupt descent to zero. This temperature gives the best measure of Tc. It is also shown that small oscillations of low frequency start near onset conditions, the amplitude of which at a given temperature is B-field dependent. Additionally, Hall effect studies as a function of temperature at 4 T in three separate experiments (including high Tc BiSrCaCu PbO of > 90% theoretical density) show that sharp delta-function-like peaks in + RH are observed near Tc and are superimposed on a broader maximum. The Hall data are explicable in terms of exciton formation and ionization. The bound holes associated with these excitons are believed to be the mediators producing Cooper-pairing, and scale very well with Tc for all the known high Tc oxides.

  12. Life-threatening gastrointestinal system bleeding in Hodgkin disease: multidetector CT findings and review of the literature.

    PubMed

    Akpinar, Erhan; Türkbey, Bariş; Cil, Barbaros Erhan; Canyiğit, Murat; Dündar, Ziya; Balkanci, Ferhun

    2007-06-01

    Acute lower gastrointestinal system (GIS) bleeding is a life-threatening condition. Immediate determination of the origin of the bleeding is crucial, since hemostatic management must be initiated as rapidly as possible. Colonoscopy, radionuclide studies, and conventional angiography are considered the most important methods for assessing the origin of the bleeding. There are few published reports about the feasibility of computed tomography (CT) in acute GIS bleeding. We present multidetector CT (MDCT) findings in a case of Hodgkin disease status one month post-chemotherapy (CHOP protocol; cyclophosphamide, doxorubicin, vincristine, prednisone) that presented with acute lower GIS bleeding.

  13. Bimetallic Porous Iron (pFe) Materials for Remediation/Removal of Tc from Aqueous Systems

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Li, D.

    Remediation of Tc remains an unresolved challenge at SRS and other DOE sites. The objective of this project was to develop novel bimetallic porous iron (pFe) materials for Tc removal from aqueous systems. We showed that the pFe is much more effective in removing TcO 4 - (×30) and ReO 4 - (×8) from artificial groundwater than granular iron. Tc K-edge XANES spectroscopy indicated that Tc speciation on the pFe was 18% adsorbed TcO 4 -, 28% Tc(IV) in Tc dioxide and 54% Tc(IV) into the structure of Fe hydroxide. A variety of catalytic metal nanoparticles (i.e., Ni, Cu, Zn,more » Ag, Sn and Pd) were successfully deposited on the pFe using scalable chemical reduction methods. The Zn-pFe was outstanding among the six bimetallic pFe materials, with a capacity increase of >100% for TcO 4 - removal and of 50% for ReO 4 - removal, compared to the pFe. These results provide a highly applicable platform for solving critical DOE and industrial needs related to nuclear environmental stewardship and nuclear power production.« less

  14. Current role of multidetector computed tomography in imaging of wrist injuries.

    PubMed

    Syed, Mohd Arif; Raj, Vimal; Jeyapalan, Kanagaratnam

    2013-01-01

    Imaging of the wrist is challenging to both radiologists and orthopedic surgeons. This is primarily because of the complex anatomy/functionality of the wrist and also the fact that many frequent injuries are sustained to the hands. On going developments in multidetector computed tomography (MDCT) technology with its "state of the art" postprocessing capabilities have revolutionized this field. Apart from routine imaging of wrist trauma, it is now possible to assess intrinsic ligaments with MDCT arthrography, thereby avoiding invasive diagnostic arthroscopies. Postoperative wrist imaging can be a diagnostic challenge, and MDCT can be helpful in assessment of these cases because volume acquisition and excellent postprocessing abilities help to evaluate these wrists in any desired plane and thinner slices. This article pictorially reviews the current clinical role of MDCT imaging of wrist in our practice. It also describes arthrography technique and scanning parameters used at our center. Copyright © 2013 Mosby, Inc. All rights reserved.

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

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Asmussen, R. Matthew; Neeway, James J.; Lawter, Amanda R.

    2016-11-01

    Technetium-99 is a radioactive contaminant of high concern at many nuclear waste storage sites. At the U.S. Department of Energy Hanford Site, 99Tc is a component of low-activity waste (LAW) fractions of the nuclear tank waste, which are highly caustic, high ionic strength and have high concentrations of chromate. Removal of 99Tc from LAW streams would greatly benefit the site remediation process. In this study, we investigated the removal of 99Tc(VII), as pertechnetate, from deionized water (DIW) and a LAW simulant using two solid sorbents, tin (II) apatite (Sn-A) and SnCl2 through batch sorption testing and solid phase characterization. Sn-Amore » showed higher levels of removal of Tc from both DIW and LAW simulant compared with the SnCl2. Scanning electron microscopy/energy dispersive X-ray spectroscopy (SEM/XEDS) and X-ray adsorption spectroscopy (XAS) of Sn-A following batch experiments in DIW showed that TcO4- is reduced to Tc(IV) on the Sn-A surface with no incorporation into the lattice structure of Sn-A. The performance of Sn-A in the LAW simulant was lowered due to a combined effect of the high alkalinity, which lead to an increased dissolution of Sn from the Sn-A, and a preference for the reduction of Cr(VI) over Tc(VII).« less

  16. In vitro and in vivo comparison of binding of 99m-Tc-labeled anti-CEA MAb F33-104 with 99m-Tc-labeled anti-CEA MAb BW431/26.

    PubMed

    Watanabe, N; Oriuchi, N; Sugiyama, S; Kuroki, M; Matsuoka, Y; Tanada, S; Murata, H; Inoue, T; Sasaki, Y

    1999-01-01

    The purpose of this study was to assess the potential for radio-immunodetection (RAID) of murine anti-carcinoembryonic antigen (CEA) monoclonal antibody (MAb) F33-104 labeled with technetium-99m (99m-Tc) by a reduction-mediated labeling method. The binding capacity of 99m-Tc-labeled anti-CEA MAb F33-104 with CEA by means of in vitro procedures such as immunoradiometric assay and cell binding assay and the biodistribution of 99m-Tc-labeled anti-CEA MAb F33-104 in normal nude mice and nude mice bearing human colon adenocarcinoma LS180 tumor were investigated and compared with 99m-Tc-labeled anti-CEA MAb BW431/26. The in vitro binding rate of 99m-Tc-labeled anti-CEA MAb F33-104 with CEA in solution and attached to the cell membrane was significantly higher than 99m-Tc-labeled anti-CEA MAb BW431/261 (31.4 +/- 0.95% vs. 11.9 +/- 0.55% at 100 ng/mL of soluble CEA, 83.5 +/- 2.84% vs. 54.0 +/- 2.54% at 10(7) of LS 180 cells). In vivo, accumulation of 99m-Tc-labeled anti-CEA MAb F33-104 was higher at 18 h postinjection than 99m-Tc-labeled anti-CEA MAb BW431/26 (20.1 +/- 3.50% ID/g vs. 14.4 +/- 3.30% ID/g). 99m-Tc-activity in the kidneys of nude mice bearing tumor was higher at 18 h postinjection than at 3 h (12.8 +/- 2.10% ID/g vs. 8.01 +/- 2.40% ID/g of 99m-Tc-labeled anti-CEA MAb F33-104, 10.7 +/- 1.70% ID/g vs. 8.10 +/- 1.75% ID/g of 99m-Tc-labeled anti-CEA MAb BW431/26). 99m-Tc-labeled anti-CEA MAb F33-104 is a potential novel agent for RAID of recurrent colorectal cancer.

  17. (99m)Tc(CO)3(NTA): a (99m)Tc renal tracer with pharmacokinetic properties comparable to those of (131)I-OIH in healthy volunteers.

    PubMed

    Taylor, Andrew T; Lipowska, Malgorzata; Marzilli, Luigi G

    2010-03-01

    Studies in rats showed that the pharmacokinetics of the tricarbonyl core radiopharmaceutical (99m)Tc(CO)(3)-nitrilotriacetic acid, (99m)Tc(CO)(3)(NTA), were essentially identical to those of (131)I ortho-iodohippuran ((131)I-OIH), the clinical gold standard for the measurement of effective renal plasma flow. Our objective was to compare the pharmacokinetics of these 2 tracers in healthy volunteers. (99m)Tc(CO)(3)(NTA) was prepared with commercially available NTA and a commercially available kit and isolated by reversed-phase high-performance liquid chromatography. Approximately 74 MBq (2 mCi) of (99m)Tc(CO)(3)(NTA) were coinjected with 9.25 MBq (250 microCi) of (131)I-OIH in 9 volunteers, and simultaneous imaging of each tracer was performed for 24 min. Plasma clearances were determined from 8 blood samples obtained 3-90 min after injection using the single-injection, 2-compartment model. Plasma protein binding, red cell uptake, and percentage injected dose in the urine at 30 and 180 min were determined. There was no difference in the plasma clearances of (99m)Tc(CO)(3)(NTA) and (131)I-OIH, 475 +/- 105 mL/min versus 472 +/- 108 mL/min, respectively. The plasma protein binding and red cell uptake of (99m)Tc(CO)(3)(NTA) were 43% +/- 5% and 9% +/- 6%, respectively; both values were significantly lower (P < 0.001) than the plasma protein binding (75% +/- 3%) and red cell uptake (17% +/- 5%) of (131)I-OIH. There was no significant difference in the percentage injected dose recovered in the urine at 30 min and at 3 h; for comparison, the percentage dose in the urine at 3 h was 91% +/- 4% for (99m)Tc(CO)(3)(NTA) and 91% +/- 6% for (131)I-OIH (P = 0.96). Image quality with (99m)Tc(CO)(3)(NTA) was excellent, and the renogram parameters were similar to those of (131)I-OIH. Preliminary results in healthy volunteers suggest that the pharmacokinetic behavior of (99m)Tc(CO)(3)(NTA) is comparable to that of (131)I-OIH.

  18. Multi-detector row CT colonography: effect of collimation, pitch, and orientation on polyp detection in a human colectomy specimen.

    PubMed

    Taylor, Stuart A; Halligan, Steve; Bartram, Clive I; Morgan, Paul R; Talbot, Ian C; Fry, Nicola; Saunders, Brian P; Khosraviani, Kirosh; Atkin, Wendy

    2003-10-01

    To investigate the effects of orientation, collimation, pitch, and tube current setting on polyp detection at multi-detector row computed tomographic (CT) colonography and to determine the optimal combination of scanning parameters for screening. A colectomy specimen containing 117 polyps of different sizes was insufflated and imaged with a multi-detector row CT scanner at various collimation (1.25 and 2.5 mm), pitch (3 and 6), and tube current (50, 100, and 150 mA) settings. Two-dimensional multiplanar reformatted images and three-dimensional endoluminal surface renderings from the 12 resultant data sets were examined by one observer for the presence and conspicuity of polyps. The results were analyzed with Poisson regression and logistic regression to determine the effects of scanning parameters and of specimen orientation on polyp detection. The percentage of polyps that were detected significantly increased when collimation (P =.008) and table feed (P =.03) were decreased. Increased tube current resulted in improved detection only of polyps with a diameter of less than 5 mm. Polyps of less than 5 mm were optimally depicted with a collimation of 1.25 mm, a pitch of 3, and a tube current setting of 150 mA; polyps with a diameter greater than 5 mm were adequately depicted with 1.25-mm collimation and with either pitch setting and any of the three tube current settings. Small polyps in the transverse segment (positioned at a 90 degrees angle to the z axis of scanning) were significantly less visible than those in parallel or oblique orientations (P <.001). The effective radiation dose, calculated with a Monte Carlo simulation, was 1.4-10.0 mSv. Detection of small polyps (<5 mm) with multi-detector row CT is highly dependent on collimation, pitch, and, to a lesser extent, tube current. Collimation of 1.25 mm, combined with pitch of 6 and tube current of 50 mA, provides for reliable detection of polyps 5 mm or larger while limiting the effective radiation dose

  19. New Gastrin Releasing Peptide Receptor-Directed [99mTc]Demobesin 1 Mimics: Synthesis and Comparative Evaluation.

    PubMed

    Nock, Berthold A; Charalambidis, David; Sallegger, Werner; Waser, Beatrice; Mansi, Rosalba; Nicolas, Guillaume P; Ketani, Eleni; Nikolopoulou, Anastasia; Fani, Melpomeni; Reubi, Jean-Claude; Maina, Theodosia

    2018-04-12

    We have previously reported on the gastrin releasing peptide receptor (GRPR) antagonist [ 99m Tc]1, ([ 99m Tc]demobesin 1, 99m Tc-[N 4 '-diglycolate-dPhe 6 ,Leu-NHEt 13 ]BBN(6-13)). [ 99m Tc]1 has shown superior biological profile compared to analogous agonist-based 99m Tc-radioligands. We herein present a small library of [ 99m Tc]1 mimics generated after structural modifications in (a) the linker ([ 99m Tc]2, [ 99m Tc]3, [ 99m Tc]4), (b) the peptide chain ([ 99m Tc]5, [ 99m Tc]6), and (c) the C-terminus ([ 99m Tc]7 or [ 99m Tc]8). The effects of above modifications on the biological properties of analogs were studied in PC-3 cells and tumor-bearing SCID mice. All analogs showed subnanomolar affinity for the human GRPR, while most receptor-affine 4 and 8 behaved as potent GRPR antagonists in a functional internalization assay. In mice bearing PC-3 tumors, [ 99m Tc]1-[ 99m Tc]6 exhibited GRPR-specific tumor uptake, rapidly clearing from normal tissues. [ 99m Tc]4 displayed the highest tumor uptake (28.8 ± 4.1%ID/g at 1 h pi), which remained high even after 24 h pi (16.3 ± 1.8%ID/g), well surpassing that of [ 99m Tc]1 (5.4 ± 0.7%ID/g at 24 h pi).

  20. Study on Thermal Deformation Behavior of TC4 – ELI Titanium Alloy

    NASA Astrophysics Data System (ADS)

    Song, Y.; Zhang, F. S.; Huang, T.; Song, K. X.

    2018-05-01

    The TC4-ELI titanium alloy was subjected to hot compression deformation test by the Gleeble-1500D thermal simulation test machine. The thermal deformation behavior of the TC4-ELI titanium alloy was studied under the condition of 850°C-1050°C, 0.001s-1-10s-1 strain rate and 50% deformation. The constitutive equation of TC4-ELI titanium alloy was established based on the hyperbolic sine model of Arrhenius equation. The results show that the flow stress of TC4-ELI titanium alloy decreases with the increase of temperature at high temperature. The calculated heat activation energy of TC4-ELI titanium alloy is 300367.5807J / mol.

  1. Synthesis and evaluation of (99m)Tc chelate-conjugated bevacizumab.

    PubMed

    Camacho, Ximena; García, María Fernanda; Calzada, Victoria; Fernández, Marcelo; Porcal, Williams; Alonso, Omar; Gambini, Juan Pablo; Cabral, Pablo

    2013-03-01

    Vascular endothelial growth factor (VEGF) is one of the classic factors involved in tumor-induced angiognesis in several solid tumors. Bevacizumab, a monoclonal antibody against VEGF, can be used as an imaging tool in preclinical studies. The aim of this study was to radiolabel Bevacizumab with (99m)Tc and to evaluate in vivo its imaging properties in an adenocarcinoma animal model. For this purpose, Bevacizumab was derivatized with Suc-HYNIC as a bifunctional coupling agent. A mixture of Tricine/SnCl(2).2H(2)O was added to Bevacizumab-HYNIC and radiolabeled with (99m)TcO(4)(-). The radiochemical stability of the radiolabeled antibody was assessed. Biodistribution and scintigraphy imaging were performed in normal CD1 female mice and in spontaneous adenocarcinoma tumor bearing CD1 mice (n = 5). We demonstrated that 99mTc-HYNIC-Bevacizumab was stable. In vivo biodistribution studies revealed that tumor uptake of (99m)Tc-HYNIC-Bevacizumab was 1.37 ± 0.51% and 5.33 ± 2.13% at 4 and 24 h postinjection, respectively. Scintigraphy image studies showed tumor selective uptake of (99m)Tc-HYNIC-Bevacizumab in the tumor-bearing mice. We conclude that (99m)Tc-HYNIC-Bevacizumb has the potential to be used as a tracer for tumor imaging in preclinical studies.

  2. Deformation behavior of TC6 alloy in isothermal forging

    NASA Astrophysics Data System (ADS)

    Li, Xiaoli; Li, Miaoquan; Zhu, Dasong; Xiong, Aiming

    2005-10-01

    Isothermal compression of the TC6 alloy was carried out in a Thermecmaster-Z (Wuhan Iron and Steel Corporation, P.R. China) simulator at deformation temperatures of 800˜1040 °C, strain rates of 0.001˜50.0 s-1, and maximum height reduction of 50%. The deformation behavior of the TC6 alloy in isothermal forging was characterized based on stress-strain behavior and kinetic analysis. The activation energy of deformation obtained in the isothermal forging of the TC6 alloy was 267.49 kJ/mol in the β phase region and 472.76 kJ/mol in the α+β phase region. The processing map was constructed based on the dynamic materials model, and the optimal deformation parameters were obtained. Constitutive equations describing the flow stress as a function of strain rate, strain, and deformation temperature were proposed for the isothermal forging of the TC6 alloy, and a good agreement between the predicted and experimental stress-strain curves was achieved.

  3. Hydrometeor Trajectories and Distributions in a Simulation of TC Rapid Intensification (RI)

    NASA Astrophysics Data System (ADS)

    Zhu, Z.; Zhu, P.

    2010-12-01

    It has long been recognized that the microphysics scheme used in a numerical simulation of tropical cyclones (TC) can greatly affect the precipitation distribution, intensity and thermodynamic structure of the simulated TC. This suggests that the mixing ratios, concentrations and size distributions of hydrometeor(snow, graupel,rain,cloud ice) are important factors in the evolution of TC . The transport of hydrometeor may have a strong influence on these factors through its interactions with the growth and the latent heat forcing of hydrometeor and the wind filed, hence is a key to understanding TC microphysics. Schematic hydrometeor trajectories were first constructed using 3-D wind field and particle fallspeeds derived from airborne radar observations in a steady-state mature hurricane,Alicia(1983). Since then, little effort has been put in understanding hydrometeor transport in TC, especially the potential link between its evolution and the intensity and structure changes in a non-steady-state TC. This study is focused on investigating such a link by means of numerical simulations of TC Rapid Intensification(RI) using WRF model. We use the tracer utility in WRF to construct hydrometeor trajectories. Most of the popular microphysics schemes are tested, and the most reasonable test( which is determined by comparing the simulated TC intensity and structure with airborne radar observations) and the ensemble mean of all the tests are picked for detailed examinations.

  4. Imaging of Cerebral Amyloid Angiopathy with Bivalent 99mTc-Hydroxamamide Complexes

    NASA Astrophysics Data System (ADS)

    Iikuni, Shimpei; Ono, Masahiro; Watanabe, Hiroyuki; Matsumura, Kenji; Yoshimura, Masashi; Kimura, Hiroyuki; Ishibashi-Ueda, Hatsue; Okamoto, Yoko; Ihara, Masafumi; Saji, Hideo

    2016-05-01

    Cerebral amyloid angiopathy (CAA), characterized by the deposition of amyloid aggregates in the walls of cerebral vasculature, is a major factor in intracerebral hemorrhage and vascular cognitive impairment and is also associated closely with Alzheimer’s disease (AD). We previously reported 99mTc-hydroxamamide (99mTc-Ham) complexes with a bivalent amyloid ligand showing high binding affinity for β-amyloid peptide (Aβ(1-42)) aggregates present frequently in the form in AD. In this article, we applied them to CAA-specific imaging probes, and evaluated their utility for CAA-specific imaging. In vitro inhibition assay using Aβ(1-40) aggregates deposited mainly in CAA and a brain uptake study were performed for 99mTc-Ham complexes, and all 99mTc-Ham complexes with an amyloid ligand showed binding affinity for Aβ(1-40) aggregates and very low brain uptake. In vitro autoradiography of human CAA brain sections and ex vivo autoradiography of Tg2576 mice were carried out for bivalent 99mTc-Ham complexes ([99mTc]SB2A and [99mTc]BT2B), and they displayed excellent labeling of Aβ depositions in human CAA brain sections and high affinity and selectivity to CAA in transgenic mice. These results may offer new possibilities for the development of clinically useful CAA-specific imaging probes based on the 99mTc-Ham complex.

  5. Imaging of Cerebral Amyloid Angiopathy with Bivalent (99m)Tc-Hydroxamamide Complexes.

    PubMed

    Iikuni, Shimpei; Ono, Masahiro; Watanabe, Hiroyuki; Matsumura, Kenji; Yoshimura, Masashi; Kimura, Hiroyuki; Ishibashi-Ueda, Hatsue; Okamoto, Yoko; Ihara, Masafumi; Saji, Hideo

    2016-05-16

    Cerebral amyloid angiopathy (CAA), characterized by the deposition of amyloid aggregates in the walls of cerebral vasculature, is a major factor in intracerebral hemorrhage and vascular cognitive impairment and is also associated closely with Alzheimer's disease (AD). We previously reported (99m)Tc-hydroxamamide ((99m)Tc-Ham) complexes with a bivalent amyloid ligand showing high binding affinity for β-amyloid peptide (Aβ(1-42)) aggregates present frequently in the form in AD. In this article, we applied them to CAA-specific imaging probes, and evaluated their utility for CAA-specific imaging. In vitro inhibition assay using Aβ(1-40) aggregates deposited mainly in CAA and a brain uptake study were performed for (99m)Tc-Ham complexes, and all (99m)Tc-Ham complexes with an amyloid ligand showed binding affinity for Aβ(1-40) aggregates and very low brain uptake. In vitro autoradiography of human CAA brain sections and ex vivo autoradiography of Tg2576 mice were carried out for bivalent (99m)Tc-Ham complexes ([(99m)Tc]SB2A and [(99m)Tc]BT2B), and they displayed excellent labeling of Aβ depositions in human CAA brain sections and high affinity and selectivity to CAA in transgenic mice. These results may offer new possibilities for the development of clinically useful CAA-specific imaging probes based on the (99m)Tc-Ham complex.

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

    PubMed

    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.

  7. Localized chemistry of 99Tc in simulated low activity waste glass

    NASA Astrophysics Data System (ADS)

    Weaver, Jamie L.

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

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

    PubMed

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

    2013-05-01

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

  9. Emerging role of multi-detector computed tomography in the diagnosis of hematuria following percutaneous nephrolithotomy: A case scenario.

    PubMed

    Sivanandam, S E; Mathew, Georgie; Bhat, Sanjay H

    2009-07-01

    Persistent hematuria is one of the most dreaded complications following percutanous nephrolithotomy (PCNL). Although invasive, a catheter-based angiogram is usually used to localize the bleeding vessel and subsequently embolize it. Advances in imaging technology have now made it possible to use a non invasive multi-detector computed tomography (MDCT) angiogram with 3-D reconstruction to establish the diagnosis. We report a case of post-PCNL hemorrhage due to a pseudo aneurysm that was missed by a conventional angiogram and subsequently detected on MDCT angiogram.

  10. Statistical inference for tumor growth inhibition T/C ratio.

    PubMed

    Wu, Jianrong

    2010-09-01

    The tumor growth inhibition T/C ratio is commonly used to quantify treatment effects in drug screening tumor xenograft experiments. The T/C ratio is converted to an antitumor activity rating using an arbitrary cutoff point and often without any formal statistical inference. Here, we applied a nonparametric bootstrap method and a small sample likelihood ratio statistic to make a statistical inference of the T/C ratio, including both hypothesis testing and a confidence interval estimate. Furthermore, sample size and power are also discussed for statistical design of tumor xenograft experiments. Tumor xenograft data from an actual experiment were analyzed to illustrate the application.

  11. Oxidative Stability of Tc(I) Tricarbonyl Species Relevant to the Hanford Tank Waste

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Chatterjee, Sayandev; Hall, Gabriel B.; Levitskaia, Tatiana G.

    Technetium (Tc), which exists predominately in the liquid supernatant and salt cake fractions of the nuclear tank waste stored at the U.S. DOE Hanford Site, is one of the most difficult contaminants to dispose of and/or remediate. In the strongly alkaline environments prevalent in the tank waste, its dominant chemical form is pertechnetate (TcO 4 -, oxidation state +7). However, based on experimentation to-date, a significant fraction of the soluble Tc cannot be effectively separated from the wastes and may be present as a non-pertechnetate species. The presence of a non pertechnetate species significantly complicates disposition of low-activity waste (LAW),more » and the development of methods to either convert them to pertechnetate or to separate the non-pertechnetate species directly is needed. The challenge is the uncertainty regarding the nature and stability of the alkaline-soluble, low-valence, non pertechnetate species in the liquid tank waste. One objective of the Tc management project is to address this knowledge gap. This fiscal year (FY) 2015 report summarizes experimental work exploring the oxidative stability of model low-valence Tc(I) tricarbonyl species, derived from the [Tc(CO) 3] + moiety. These compounds are of interest due to their implied presence in several Hanford tank waste supernatants. Work in part was initiated in FY 2014, and a series of samples containing non-pertechnetate Tc generated ex situ or in situ in pseudo-Hanford tank supernatant simulant solutions was prepared and monitored for oxidation to Tc(VII) (Levitskaia et al. 2014). This experimentation continued in FY 2015, and new series of samples containing Tc(I) as [Tc(CO) 3] +•Ligand was tested. The monitoring method used for these studies was a combination of 99Tc NMR and EPR spectroscopies.« less

  12. Development and Pharmacological Evaluation of New Bone-Targeted (99m)Tc-Radiolabeled Bisphosphonates.

    PubMed

    Makris, George; Tseligka, Eirini D; Pirmettis, Ioannis; Papadopoulos, Minas S; Vizirianakis, Ioannis S; Papagiannopoulou, Dionysia

    2016-07-05

    A novel bisphosphonate, 1-(3-aminopropylamino)ethane-1,1-diyldiphosphonic acid (3), was coupled to the tridentate chelators di-2-picolylamine, 2-picolylamine-N-acetic acid, iminodiacetic acid, 3-((2-aminoethyl)thio)-3-(1H-imidazol-4-yl)propanoic acid, and 2-((2-carboxyethyl)thio)-3-(1H-imidazol-4-yl)propanoic acid to form ligands 6, 9, 11, 15, and 19, respectively. Organometallic complexes of the general formula [Re/(99m)Tc(CO)3(κ(3)-L)] were synthesized, where L denotes ligand 6, 9, 11, 15, or 19. The rhenium complexes were prepared at the macroscopic level and characterized by spectroscopic methods. The technetium-99m organometallic complexes were synthesized in high yield and were identified by comparative reversed-phase HPLC with their Re analogues. The (99m)Tc tracers were stable in vitro and exhibited binding to hydroxyapatite. In biodistribution studies, all of the (99m)Tc complexes exhibited high bone uptake superior to that of 25, which is the directly (99m)Tc-labeled bisphosphonate 3, and comparable to that of (99m)Tc-methylene diphosphonate ((99m)Tc-MDP). The tracers [(99m)Tc(CO)3(6)] (26), [(99m)Tc(CO)3(9)] (27), [(99m)Tc(CO)3(11)] (28), and [(99m)Tc(CO)3(15)] (29) exhibited higher bone/blood ratios than (99m)Tc-MDP. 26 had the highest bone uptake at 1 h p.i. The new bisphosphonates showed no substantial growth inhibitory capacity in PC-3, Saos-2, and MCF-7 established cancer cell lines at low concentrations. Incubation of 26 with the same cancer cell lines indicated a rapid and saturated uptake. The promising properties of 26-29 indicate their potential for use as bone-imaging agents.

  13. Update of global TC simulations using a variable resolution non-hydrostatic model

    NASA Astrophysics Data System (ADS)

    Park, S. H.

    2017-12-01

    Using in a variable resolution meshes in MPAS during 2017 summer., Tropical cyclone (TC) forecasts are simulated. Two physics suite are tested to explore performance and bias of each physics suite for TC forecasting. A WRF physics suite is selected from experience on weather forecasting and CAM (Community Atmosphere Model) physics is taken from a AMIP type climate simulation. Based on the last year results from CAM5 physical parameterization package and comparing with WRF physics, we investigated a issue with intensity bias using updated version of CAM physics (CAM6). We also compared these results with coupled version of TC simulations. During this talk, TC structure will be compared specially around of boundary layer and investigate their relationship between TC intensity and different physics package.

  14. Oxidative dissolution potential of biogenic and abiogenic TcO 2 in subsurface sediments

    NASA Astrophysics Data System (ADS)

    Fredrickson, James K.; Zachara, John M.; Plymale, Andrew E.; Heald, Steve M.; McKinley, James P.; Kennedy, David W.; Liu, Chongxuan; Nachimuthu, Ponnusamy

    2009-04-01

    Technetium-99 (Tc) is an important fission product contaminant associated with sites of nuclear fuels reprocessing and geologic nuclear waste disposal. Tc is highly mobile in its most oxidized state [Tc(VII)O4-] and less mobile in the reduced form [Tc(IV)O 2· nH 2O]. Here we investigate the potential for oxidation of Tc(IV) that was heterogeneously reduced by reaction with biogenic Fe(II) in two sediments differing in mineralogy and aggregation state; unconsolidated Pliocene-age fluvial sediment from the upper Ringold (RG) Formation at the Hanford Site and a clay-rich saprolite from the Field Research Center (FRC) background site on the Oak Ridge Site. Both sediments contained Fe(III) and Mn(III/IV) as redox active phases, but FRC also contained mass-dominant Fe-phyllosilicates of different types. Shewanella putrefaciens CN32 reduced Mn(III/IV) oxides and generated Fe(II) that was reactive with Tc(VII) in heat-killed, bioreduced sediment. After bioreduction and heat-killing, biogenic Fe(II) in the FRC exceeded that in RG by a factor of two. More rapid reduction rates were observed in the RG that had lower biogenic Fe(II), and less particle aggregation. EXAFS measurements indicated that the primary reduction product was a TcO 2-like phase in both sediments. The biogenic redox product Tc(IV) oxidized rapidly and completely in RG when contacted with air. Oxidation, in contrast, was slow and incomplete in the FRC, in spite of similar molecular scale speciation of Tc compared to RG. X-ray microprobe, electron microprobe, X-ray absorption spectroscopy, and micro X-ray diffraction were applied to the whole sediment and isolated Tc-containing particles. These analyses revealed that non-oxidizable Tc(IV) in the FRC existed as complexes with octahedral Fe(III) within intra-grain domains of 50-100 μm-sized, Fe-containing micas presumptively identified as celadonite. The markedly slower oxidation rates in FRC as compared to RG were attributed to mass

  15. Specificity and sensitivity of ⁹⁹mTc-EDDA/HYNIC-Tyr³-octreotide (⁹⁹mTc-TOC) for imaging neuroendocrine tumors.

    PubMed

    Sepúlveda-Méndez, Jesús; de Murphy, Consuelo Arteaga; Pedraza-López, Martha; Murphy-Stack, Eduardo; Rojas-Bautista, Juan Carlos; González-Treviño, Ofelia

    2012-01-01

    Gastroenteropancreatic neuroendocrine tumors (NETs) are cancers originating from neuroendocrine organs such as the pancreas, pituitary, thyroid, and adrenal glands and tumors arising from the diffuse neuroendocrine cells that are widely distributed throughout the body. NETs express somatostatin (SS) and contain a high density of SS receptors; therefore, they can be specifically targeted with SS-based radiopharmaceuticals. The aim of this research was to determine the validity in terms of specificity, sensitivity, and the agreement beyond chance with the biopsy (gold standard) of the ⁹⁹mTc-EDDA-HYNIC-Tyr³octreotide (⁹⁹mTc-TOC) to image and localize NETs and their metastases. Freeze-dried kits containing 0.0125 mg HYNIC-octreotide and co-ligands were easily labeled and quality controlled within the hospital radiopharmacy. Fifty-six consecutive Mexican patients with a previous presumptive diagnosis of NETs underwent several clinical and laboratory studies and were referred to the Nuclear Medicine Department for a routine scan with ⁹⁹mTc-TOC. The patients were injected with 500-600 MBq ⁹⁹mTc-TOC, and whole-body images were obtained 2 h later with a SPECT or a SPECT/CT camera. Two nuclear medicine physicians observed the images and classified them as 17 negative and 39 positive. After correlating the image of each patient with our 'gold standard' (biopsy, clinical history, morphological images, and tumor marker assays), the ⁹⁹mTc-TOC images were classified by the same two physicians as 12 true negatives, five false negatives, 38 true positives and one false positive. The validity of ⁹⁹mTc-TOC in terms of relative frequencies with corresponding 95% confidence intervals were as follows: 92.3% (64-100%) specificity; 88.4% (78-97%) sensitivity; and the agreement beyond chance was 73% (60-84%). The positive predictive value was 97.4% (87-100%); the negative predicted value was 70.6% (48-93%); the accuracy was 89.3% (89-97%); and the prevalence was 76

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

    PubMed

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

    2013-10-01

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

  17. Structural characterization of a bridged 99Tc-Sn-dimethylglyoxime complex: implications for the chemistry of 99mTc-radiopharmaceuticals prepared by the Sn (II) reduction of pertechnetate.

    PubMed Central

    Deutsch, E; Elder, R C; Lange, B A; Vaal, M J; Lay, D G

    1976-01-01

    Reduction of pertechnetate by tin(II) in the presence of dimethylglyoxime is shown, by single crystal x-ray analysis, to yield a technetium-tin-dimethylglyoxime complex in which tin and technetium are intimately connected by a triple bridging arrangement. One bridge consists of a single oxygen atom and it is hypothesized that this bridge arises from the inner sphere reduction of technetium by tin(II), the electrons being transferred through a technetium "yl" oxygen which eventually becomes the bridging atom. Two additional bridges arise from two dimethylglyoxime ligands that function as bidentate nitrogen donors towards Tc and monodentate oxygen donors towards Sn. The tin atom can thus be viewed as providing a three-pronged "cap" on one end of the Tc-dimethylglyoxime complex. The additional coordination sites around Tc are occupied by the two nitrogens of a third dimethylglyoxime ligand, making the Tc seven-coordinate. The additional coordination sites around Sn are occupied by three chloride anions, giving the Sn a fac octahedral coordination environment. From indirect evidence the oxidation states of tin and technetium are tentatively assigned to be IV and V, respectively. Since most 99mTc-radiopharmaceuticals are synthesized by the tin(II) reduction of pertechnetate, it is likely that the Sn-O-Tc linkage described in this work is an important feature of the chemistry of these species. This linkage also provides a ready rationale for the close association of tin and technetium observed in many 99mTc-radiopharmaceuticals. PMID:1069984

  18. Evaluation of (99)  (m)TcN-MPO as a new myocardial perfusion imaging agent in normal dogs and in an acute myocardial infarction canine model: comparison with (99)  (m)Tc-sestamibi.

    PubMed

    Bu, Lihong; Li, Renfei; Jin, Zhongnan; Wen, Xiaofei; Liu, Shuang; Yang, Baofeng; Shen, Baozhong; Chen, Xiaoyuan

    2011-02-01

    (99)  (m)TcN-MPO ([(99)  (m)TcN(mpo)(PNP5)](+): mpo = 2-mercaptopyridine oxide and PNP5 = N-ethoxyethyl-N,N-bis[2-(bis(3-methoxypropyl)phosphino)ethyl]amine) is a cationic (99)  (m)Tc-nitrido complex, which has favorable biodistribution and myocardial uptake with rapid liver clearance in Sprague Dawley rats. The objective of this study was to compare the biodistribution and pharmacokinetics of (99)  (m)TcN-MPO and (99)  (m)Tc-Sestamibi in normal dogs, and to evaluate the potential of (99)  (m)TcN-MPO as a myocardial perfusion agent in canines with acute myocardial infarction. Five normal mongrel dogs were injected intravenously with (99)  (m)TcN-MPO. Venous blood samples were collected via a femoral vein catheter at 0.5, 1, 2, 3, 4, 5, 10, 20, 30, 40, 60, and 90 min post-injection (p.i.). Anterior-posterior planar images were acquired by γ-camera at 10, 20, 30, 60, 90, and 120 min p.i. Regions of interest (ROIs) were drawn around the heart, liver, and lungs. The heart/liver and heart/lung ratios were calculated by dividing the mean counts in heart ROI by the mean counts in the liver and lung ROI, respectively. For comparison, (99)  (m)Tc-sestamibi was also evaluated in the same five dogs. The interval period between the two examinations was 1 week to eliminate possible interference between these two radiotracers. In addition, single positron emission computed tomography (SPECT) images in the canine infarct model were collected 24 h after myocardial infarction at 30 and 60 min after the administration of (99)  (m)TcN-MPO (n = 4) or (99)  (m)Tc-Sestamibi (n = 4). It was found that (99)  (m)TcN-MPO and (99)  (m)Tc-Sestamibi displayed very similar blood clearance characteristics during the first 90 min p.i. Both (99)  (m)TcN-MPO and (99)  (m)Tc-Sestamibi had a rapid blood clearance with less than 50% of initial radioactivity remaining at 1 min and less than 5% at 30 min p.i. (99)  (m)TcN-MPO and (99)  (m)Tc-Sestamibi both showed good

  19. Tc-99m TRODAT uptake in an osteoid tumor of clivus.

    PubMed

    Taywade, Sameer; Tripathi, Madhavi; Tandon, Vivek; Das, Chandan Jyoti; Damle, Nishikant Avinash; Shamim, Shamim Ahmed; Thukral, Parul; Bal, Chandrasekhar

    2016-01-01

    Tc-99m TRODAT is cocaine analog and binds to the dopamine transporter in vivo . Tc-99m TRODAT single-photon emission computed tomography/computed tomography. (SPECT/CT) is useful for demonstrating presynaptic dopaminergic dysfunction in patients with Parkinsonism. However, few reports have shown extrastriatal uptake of Tc-99m TRODAT. We present the case of a 67-year-old male who underwent Tc-99m TRODAT SPECT/CT for evaluation of Parkinsonism. In addition to tracer binding in the striatum, tracer uptake was noted in an osteoid tumor of the clivus. Integrated SPECT/CT enabled precise localization and characterization of the extrastriatal site of tracer binding and emphasizes the importance of such coincidental findings.

  20. A Tc-99m-labeled long chain fatty acid derivative for myocardial imaging.

    PubMed

    Magata, Yasuhiro; Kawaguchi, Takayoshi; Ukon, Misa; Yamamura, Norio; Uehara, Tomoya; Ogawa, Kazuma; Arano, Yasushi; Temma, Takashi; Mukai, Takahiro; Tadamura, Eiji; Saji, Hideo

    2004-01-01

    C-11- and I-123-labeled long chain fatty acid derivatives have been reported as useful radiopharmaceuticals for the estimation of myocardial fatty acid metabolism. We have reported that Tc-99m-labeled N-[[[(2-mercaptoethyl)amino]carbonyl]methyl]-N-(2-mercaptoethyl)-6-aminohexanoic acid ([(99m)Tc]MAMA-HA), a medium chain fatty acid derivative, is metabolized by beta-oxidation in the liver and that the MAMA ligand is useful for attaching to the omega-position of fatty acid derivatives as a chelating group for Tc-99m. On the basis of these findings, we focused on developing a Tc-99m-labeled long chain fatty acid derivative that reflected fatty acid metabolism in the myocardium. In this study, we synthesized a dodecanoic acid derivative, MAMA-DA, and a hexadecanoic acid derivative, MAMA-HDA, and performed radiolabeling and biodistribution studies. [(99m)Tc]MAMA-DA and [(99m)Tc]MAMA-HDA were prepared using a ligand-exchange reaction. Biodistribution studies were carried out in normal mice and rats. Then, a high initial uptake of Tc-99m was observed, followed by a rapid clearance from the heart. The maximum heart/blood ratio was 3.6 at 2 min postinjection of [(99m)Tc]MAMA-HDA. These kinetics were similar to those with postinjection of p-[(125)I]iodophenylpentadecanoic acid. Metabolite analysis showed [(99m)Tc]MAMA-HDA was metabolized by beta-oxidation in the body. In conclusion, [(99m)Tc]MAMA-HDA is a promising compound as a long chain fatty acid analogue for estimating beta-oxidation of fatty acid in the heart.

  1. Fabrication Of High-Tc Superconducting Integrated Circuits

    NASA Technical Reports Server (NTRS)

    Bhasin, Kul B.; Warner, Joseph D.

    1992-01-01

    Microwave ring resonator fabricated to demonstrate process for fabrication of passive integrated circuits containing high-transition-temperature superconductors. Superconductors increase efficiencies of communication systems, particularly microwave communication systems, by reducing ohmic losses and dispersion of signals. Used to reduce sizes and masses and increase aiming accuracies and tracking speeds of millimeter-wavelength, electronically steerable antennas. High-Tc superconductors preferable for such applications because they operate at higher temperatures than low-Tc superconductors do, therefore, refrigeration systems needed to maintain superconductivity designed smaller and lighter and to consume less power.

  2. Synthesis, 99m Tc-labeling, and preliminary biological evaluation of DTPA-melphalan conjugates.

    PubMed

    Wang, Jianjun; Yang, Wenjiang; Xue, Jinquan; Zhang, Yanhua; Liu, Yu

    2017-12-01

    Melphalan (MFL) is a typical nitrogen mustard for the treatment of many types of cancer. For the purpose to develop novel 99m Tc-labeled tumor imaging agents with SPECT, MFL was directly labeled by 99m Tc using diethylene triamine pentacetate acid (DTPA) as bifunctional chelating agent. The novel ligands were successfully synthesized by conjugation of DTPA to MFL to get monosubstituted DTPA-MFL and bis-substituted DTPA-2MFL. Radiolabeling was performed in high yield to get 99m Tc-DTPA-MFL and 99m Tc-DTPA-2MFL, respectively, which were hydrophilic and stable at room temperature. The high initial tumor uptake with retention, good tumor/muscle ratios, and satisfactory scintigraphic images suggested the potential of 99m Tc-DTPA-MFL and 99m Tc-DTPA-2MFL for tumor imaging. However, the slow normal tissue clearance would be a great obstacle. Further modification on the linker and/or 99m Tc-chelate to improve the tumor targeting efficacy and in vivo kinetic profiles is currently in progress. Copyright © 2017 John Wiley & Sons, Ltd.

  3. Multidetector CT of expected findings and complications after contemporary inguinal hernia repair surgery

    PubMed Central

    Tonolini, Massimo

    2016-01-01

    Inguinal hernia repair (IHR) with prosthetic mesh implantation is the most common procedure in general surgery, and may be performed using either an open or laparoscopic approach. This paper provides an overview of contemporary tension-free IHR techniques and materials, and illustrates the expected postoperative imaging findings and iatrogenic injuries. Emphasis is placed on multidetector CT, which represents the ideal modality to comprehensively visualize the operated groin region and deeper intra-abdominal structures. CT consistently depicts seroma, mesh infections, hemorrhages, bowel complications and urinary bladder injuries, and thus generally provides a consistent basis for therapeutic choice. Since radiologists are increasingly requested to investigate suspected iatrogenic complications, this paper aims to provide an increased familiarity with early CT studies after IHR, including complications and normal postoperative appearances such as focal pseudolesions, in order to avoid misinterpretation and inappropriate management. PMID:27460285

  4. Experimental study of {sup 99m}Tc-aluminum oxide use for sentinel lymph nodes detection

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Chernov, V. I., E-mail: Chernov@oncology.tomsk.ru; Sinilkin, I. G.; Zelchan, R. V.

    The purpose of the study was a comparative research in the possibility of using the radiopharmaceuticals {sup 99m}Tc-Al{sub 2}O{sub 3} and {sup 99m}Tc-Nanocis for visualizing sentinel lymph nodes. The measurement of the sizes of {sup 99m}Tc-Al{sub 2}O{sub 3} and {sup 99m}Tc-Nanocis colloidal particles was performed in seven series of radiopharmaceuticals. The pharmacokinetics of {sup 99m}Tc-Al{sub 2}O{sub 3} and {sup 99m}Tc-Nanocis was researched on 50 white male rats. The possibility of the use of {sup 99m}Tc-Al{sub 2}O{sub 3} and {sup 99m}Tc-Nanocis for lymphoscintigraphy was studied in the experiments on 12 white male rats. The average dynamic diameter of the sol particlemore » was 52–77 nm for {sup 99m}Tc-Al{sub 2}O{sub 3} and 16.7–24.5 nm for {sup 99m}Tc-Nanocis. Radiopharmaceuticals accumulated in the inguinal lymph node in 1 hour after administration; the average uptake of {sup 99}mTc-Al{sub 2}O{sub 3} was 8.6% in it, and the accumulation of {sup 99m}Tc-Nanocis was significantly lower—1.8% (p < 0.05). In all study points the average uptake of {sup 99m}Tc-Al{sub 2}O{sub 3} in the lymph node was significantly higher than {sup 99m}Tc-Nanocis accumulation. The results of dynamic scintigraphic studies in rats showed that {sup 99m}Tc-Al{sub 2}O{sub 3} and {sup 99m}Tc-Nanocis actively accumulated into the lymphatic system. By using {sup 99m}Tc-Al{sub 2}O{sub 3} inguinal lymph node was determined in 5 minutes after injection and clearly visualized in all the animals in the 15th minute, when the accumulation became more than 1% of the administered dose. Further observation indicated that the {sup 99m}Tc-Al{sub 2}O{sub 3} accumulation reached a plateau in a lymph node (average 10.5%) during 2-hour study and then its accumulation remained practically at the same level, slightly increasing to 12% in 24 hours. In case of {sup 99m}Tc-Nanocis inguinal lymph node was visualized in all animals for 15 min when it was accumulated on the average 1.03% of the

  5. (99)Tc(VII) Retardation, Reduction, and Redox Rate Scaling in Naturally Reduced Sediments.

    PubMed

    Liu, Yuanyuan; Liu, Chongxuan; Kukkadapu, Ravi K; McKinley, James P; Zachara, John; Plymale, Andrew E; Miller, Micah D; Varga, Tamas; Resch, Charles T

    2015-11-17

    An experimental and modeling study was conducted to investigate pertechnetate (Tc(VII)O4(-)) retardation, reduction, and rate scaling in three sediments from Ringold formation at U.S. Department of Energy's Hanford site, where (99)Tc is a major contaminant in groundwater. Tc(VII) was reduced in all the sediments in both batch reactors and diffusion columns, with a faster rate in a sediment containing a higher concentration of HCl-extractable Fe(II). Tc(VII) migration in the diffusion columns was reductively retarded with retardation degrees correlated with Tc(VII) reduction rates. The reduction rates were faster in the diffusion columns than those in the batch reactors, apparently influenced by the spatial distribution of redox-reactive minerals along transport paths that supplied Tc(VII). X-ray computed tomography and autoradiography were performed to identify the spatial locations of Tc(VII) reduction and transport paths in the sediments, and results generally confirmed the newly found behavior of reaction rate changes from batch to column. The results from this study implied that Tc(VII) migration can be reductively retarded at Hanford site with a retardation degree dependent on reactive Fe(II) content and its distribution in sediments. This study also demonstrated that an effective reaction rate may be faster in transport systems than that in well-mixed reactors.

  6. Preclinical evaluation of 99mTc(CO)3-aspartic-N-monoacetic acid, 99mTc(CO)3(ASMA), a new renal radiotracer with pharmacokinetic properties comparable to 131I-OIH

    PubMed Central

    Lipowska, Malgorzata; Klenc, Jeffrey; Marzilli, Luigi G.; Taylor, Andrew T.

    2014-01-01

    In an ongoing effort to develop a renal tracer with pharmacokinetic properties comparable to PAH and superior to those of both 99mTc-MAG3 and 131I-OIH, we evaluated a new renal tricarbonyl radiotracer based on the aspartic-N-monoacetic acid ligand, 99mTc(CO)3(ASMA). The ASMA ligand features two carboxyl groups and an amine function for the coordination of the {99mTc(CO)3}+ core as well as a dangling carboxylate to facilitate rapid renal clearance. Methods rac-ASMA and L-ASMA were labeled with a 99mTc-tricarbonyl precursor and radiochemical purity of the labeled products was determined by HPLC. Using 131I-OIH as an internal control, we evaluated biodistribution in normal rats with 99mTc(CO)3(ASMA) isomers and in rats with renal pedicle ligation with 99mTc(CO)3(rac-ASMA). Clearance studies were conducted in 4 additional rats. In vitro radiotracer stability was determined in PBS buffer pH 7.4 and in challenge studies with cysteine and histidine. 99mTc(CO)3(ASMA) metabolites in urine were analyzed by HPLC. Results Both 99mTc(CO)3(ASMA) preparations had > 99% radiochemical purity and were stable in PBS buffer pH 7.4 for 24 h. Challenge studies on both revealed no significant displacement of the ligand. In normal rats, % injected dose in urine at 10 and 60 min for both preparations averaged 103% and 106% that of 131I-OIH, respectively. The renal clearances of 99mTc(CO)3(rac-ASMA) and 131I-OIH were comparable (P = 0.48). The tracer was excreted unchanged in the urine, proving its in vivo stability. In pedicle-ligated rats, 99mTc(CO)3(rac-ASMA) had less excretion into the bowel (P < 0.05) and was better retained in the blood (P < 0.05) than 131I-OIH. Conclusion Both 99mTc(CO)3(ASMA) complexes have pharmacokinetic properties in rats comparable to or superior to those of 131I-OIH, and human studies are warranted for their further evaluation. PMID:22717977

  7. Role of various microorganisms on Tc behavior in sediments

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Pignolet, L.; Auvray, F.; Fonsny, K.

    1989-11-01

    Marine bacteria (Moraxella sp., Planococcus sp. and a mixed population of anaerobes) from a coastal sediment were found to concentrate Tc. Maximum concentration of this element occurred during the stationary phase of growth of the bacteria, at low redox potential. A metabolic process seems responsible for Tc concentration by bacteria, in which it binds to high molecular weight cellular constituents. Polysaccharidic polymers, which were visualized around the bacterial cells with the scanning electron microscope, might bind Tc, but direct experimental evidence in favor of this hypothesis was not yet obtained. The role of sedimentary bacteria in the behavior of Tcmore » in the marine environment is briefly discussed. The action of sulfate-reducing microorganisms is considered.« less

  8. Bioreduction of Fe-bearing clay minerals and their reactivity toward pertechnetate (Tc-99)

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Bishop, Michael E.; Dong, Hailiang; Kukkadapu, Ravi K.

    2011-07-01

    99Technetium (99Tc) is a fission product of uranium-235 and plutonium-239 and poses a high environmental hazard due to its long half-life (t1/2 = 2.13 x 105 y), abundance in nuclear wastes, and environmental mobility under oxidizing conditions [i.e., Tc(VII)]. Under reducing conditions, Tc(VII) can be reduced to insoluble Tc(IV). Ferrous iron [Fe(II)], either in aqueous form or in mineral form, has been used to reduce Tc(VII) to Tc(IV). However, the reactivity of Fe(II) from clay minerals, other than nontronite, toward immobilization of Tc(VII) and its role in retention of reduced Tc(IV) have not been investigated. In this study the reactivitymore » of a suite of clay minerals toward Tc(VII) reduction and immobilization was evaluated. The clay minerals chosen for this study included five members in the smectite-illite (S-I) series, (montmorillonite, nontronite, rectorite, mixed layered I-S, and illite), chlorite, and palygorskite. Fe-oxides were removed from these minerals with a modified dithionite-citrate-bicarbonate (DCB) procedure. The total Fe content of these clay minerals, after Fe-oxide removal, ranged from 0.7 to 30.4% by weight, and the Fe(III)/Fe(total) ratio ranged from 44.9 to 98.5%. X-ray diffraction (XRD) and Mössbauer spectroscopy results showed that after Fe oxide removal the clay minerals were free of Fe-oxides. Scanning electron microscopy (SEM) revealed that little dissolution occurred during the DCB treatment. Bioreduction experiments were performed in bicarbonate buffer (pH-7) with Fe(III) in the clay minerals as the sole electron acceptor, lactate as the sole electron donor, and Shewanella Putrifaciens CN32 cells as mediators. In select tubes, anthraquinone-2,6-disulfate (AQDS) was added as electron shuttle to facilitate electron transfer. The extent of Fe(III) bioreduction was the highest for chlorite (~43 wt%) and the lowest for palygorskite (~4.17 wt%). In the S-I series, NAu-2 was the most reducible (~31 %) and illite the least (~0

  9. Preparation and comparative evaluation of 99m Tc-HYNIC-cNGR and 99m Tc-HYNIC-PEG2 -cNGR as tumor-targeting molecular imaging probes.

    PubMed

    Vats, Kusum; Satpati, Drishty; Sharma, Rohit; Kumar, Chandan; Sarma, Haladhar Dev; Banerjee, Sharmila

    2018-02-01

    The tripeptide sequence asparagine-glycine-arginine (NGR) specifically recognizes aminopeptidase N (APN or CD13) receptors highly expressed on tumor cells and vasculature. Thus, NGR peptides can precisely deliver therapeutic and diagnostic compounds to CD13 expressing cancer sites. In this regard, 2 NGR peptide ligands, HYNIC-c(NGR) and HYNIC-PEG 2 -c(NGR), were synthesized, radiolabeled with 99m Tc, and evaluated in CD13-positive human fibrosarcoma HT-1080 tumor xenografts. The radiotracers, 99m Tc-HYNIC-c(NGR) and 99m Tc-HYNIC-PEG 2 -c(NGR), could be prepared in approximately 95% radiochemical purity and exhibited excellent in vitro and in vivo stability. The radiotracers were hydrophilic in nature with log P values being -2.33 ± 0.05 and -2.61 ± 0.08. The uptake of 2 radiotracers 99m Tc-HYNIC-c(NGR) and 99m Tc-HYNIC-PEG 2 -c(NGR) was similar in nude mice bearing human fibrosarcoma HT-1080 tumor xenografts, which was significantly reduced (P < .05) during blocking studies. The 2 radiotracers being hydrophilic cleared rapidly from blood, liver, and intestine and were excreted through renal pathway. The pharmacokinetics of 99m Tc-labeled HYNIC peptide could not be modulated through introduction of PEG 2 unit, thus posing a challenge for studies with other linkers towards enhanced tumor uptake and retention. Copyright © 2017 John Wiley & Sons, Ltd.

  10. [Evaluation of cardiac tumors by multidetector computed tomography and magnetic resonance imaging].

    PubMed

    Mercado-Guzman, Marcela P; Meléndez-Ramírez, Gabriela; Castillo-Castellon, Francisco; Kimura-Hayama, Eric

    Cardiac tumors, are a rare pathology (0.002-0.3%) in all age groups, however, they have a clinic importance, due the affected organ. They are classified in primary (benign or malignant) and secondary (metastasis) types. Among primary type, mixoma, is the most common benign tumor, and sarcoma represents most of the malignant injuries. Cardiac metastasis are more frequent than primary tumors. Clinic effects of cardiac tumors are unspecific and vary according their location, size and agresivity. The use of Multidetector Computed Tomography (MDCT) and Magnetic Resonance Imaging (MRI) assist on the location, sizing, anatomical relationships and the compromise of adyacents structures, besides, MRI is useful for tissue characterization of the tumor. Due to the previous reasons, studies based on noninvasive cardiovascular imaging, have an important role on the characterization of these lesions and the differential diagnosis among them. Copyright © 2016 Instituto Nacional de Cardiología Ignacio Chávez. Publicado por Masson Doyma México S.A. All rights reserved.

  11. 99mTc-N4-[Tyr3]Octreotate Versus 99mTc-EDDA/HYNIC-[Tyr3]Octreotide: an intrapatient comparison of two novel Technetium-99m labeled tracers for somatostatin receptor scintigraphy.

    PubMed

    Gabriel, Michael; Decristoforo, Clemens; Maina, Theodosia; Nock, Berthold; vonGuggenberg, Elisabeth; Cordopatis, Paul; Moncayo, Roy

    2004-02-01

    Tetraamine-[Tyr3]octreotate (Demotate) is a somatostatin (SST) analogue that can be easily labeled with 99mTc at high specific activities and showed promising preclinical properties for SST receptor scintigraphy. This study reports on the first intra-patient comparison of 99mTc-Demotate and another 99mTc-labeled SST analogue, 99mTc-EDDA/HYNIC-TOC (HYNIC-TOC). Five patients with carcinoid tumors (n = 2) and endocrine pancreatic tumors (n = 3) were investigated with both radiopharmaceuticals. 99mTc-Demotate rapidly visualized somatostatin receptor positive tumors as early as 15 minutes post-injection (p.i.) with maximum tumor uptake and tumor/organ ratios already 1 hour p.i. Organs of predominant physiological uptake were the spleen and the kidneys with no intestinal excretion detectable up to 24 hours. 99mTc-Demotate exhibited faster pharmacokinetic properties compared to HYNIC-TOC. Tumor/organ ratios at equivalent time points were higher or comparable for 99mTc-Demotate in three patients with a matching scan result. Equivocal findings were observed in two patients, i.e. comparable uptake behavior in larger lesions with differences in smaller ones. 99mTc-Demotate is a promising agent for somatostatin receptor scintigraphy providing images of excellent quality as early as 1 hour after injection.

  12. [Review of pre- and post-treatment multidetector computed tomography findings in abdominal aortic aneurysms].

    PubMed

    Casula, E; Lonjedo, E; Cerverón, M J; Ruiz, A; Gómez, J

    2014-01-01

    The increase in the frequency of abdominal aortic aneurysms (AAA) and the widely accepted use of endovascular aneurysm repair (EVAR) as a first-line treatment or as an alternative to conventional surgery make it necessary for radiologists to have thorough knowledge of the pre- and post-treatment findings. The high image quality provided by multidetector computed tomography (MDCT) enables CT angiography to play a fundamental role in the study of AAA and in planning treatment. The objective of this article is to review the cases of AAA in which CT angiography was the main imaging technique, so that radiologists will be able to detect the signs related to this disease, to diagnose it, to plan treatment, and to detect complications in the postoperative period. Copyright © 2012 SERAM. Published by Elsevier Espana. All rights reserved.

  13. Photochemical behavior of the quadruply metal-metal bonded [Tc 2Cl 8] 2– anion in acetonitrile

    DOE PAGES

    Burton-Pye, Benjamin P.; Poineau, Frederic; Bertoia, Julie; ...

    2016-09-23

    Here, the photochemical behavior of [Tc 2Cl 8] 2– was investigated in acetonitrile. The speciation of Tc before and after irradiation at 254 nm was performed by UV-visible spectroscopy and electrospray ionization mass spectrometry (ESI-MS). Upon irradiation at 254 nm, [Tc 2Cl 8] 2– was unstable, the scission of the TcTc unit occurred and the complex [TcCl 4(CH 3CN) 2] was identified. The disappearance rate of [M 2Cl 8] 2– (M = Tc, Re) under irradiation has been measured and was ~7.5 time faster for Tc than for Re.

  14. Synthesis of trevorite to capture Tc

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Tsui, Colin

    2011-09-02

    Spinel containing technetium can be used to prevent Tc volatilization during vitrification of radioactive waste. Spinel dissolves in glass at elevated temperatures. This study focuses on the synthesis of spinel and the retention of rhenium, a nonradioactive surrogate for Tc in the crystals. To produce trevorite, a nickel-iron spinel (NiFe2O4), Fe and Ni nitrates were mixed with alkali nitrates along with Al(OH)3 and heated to 500 to 800°C. The trevorite content in samples (up to 40 mass%) was measured with x-ray diffraction. Viable samples were rerun with KReO4. Scanning electron microscopy-energy dispersive spectroscopy detected that Re became partly immobilized inmore » spinel-forming crystals.« less

  15. Ibogaine labeling with 99mTc-tricarbonyl: synthesis and transport at the mouse blood-brain barrier.

    PubMed

    Tournier, Nicolas; André, Pascal; Blondeel, Sandy; Rizzo-Padoin, Nathalie; du Moulinet d'Hardemarre, Amaury; Declèves, Xavier; Scherrmann, Jean-Michel; Cisternino, Salvatore

    2009-12-01

    The (99m)Tc-tricarbonyl core may be used as an ideal tool for gamma-labeling ligands in noninvasive SPECT imaging. However, most (99m)Tc-tricarbonyl-labeled agents have difficulty crossing the blood-brain barrier (BBB). We radiolabeled the neuroactive indole ibogaine with (99m)Tc-tricarbonyl and measured its transport into the mouse brain by in situ brain perfusion. We measured the interactions of [(99m)Tc(CO)(3)-ibogaine](+) and (99m)Tc-tricarbonyl with the main BBB efflux transporters P-gp and BCRP in vitro and in vivo. Ibogaine was radiolabeled (yield: over 95%). [(99m)Tc(CO)(3)-ibogaine](+) entered the brain (K(in)) poorly (0.18 microL/g/s), at about the same rate as (99m)Tc-tricarbonyl (0.16 microL/g/s) and [(99m)Tc-sestamibi](+) (0.10 microL/g/s). The CNS tracer [(99m)Tc-HMPAO](0) entered the brain approximately 70-times higher than [(99m)Tc(CO)(3)-ibogaine](+). In vitro studies revealed that neither [(99m)Tc(CO)(3)-ibogaine](+) nor (99m)Tc-tricarbonyl ion were substrates for P-gp or BCRP. But lowering the membrane dipole potential barrier with phloretin enhanced the brain transport of [(99m)Tc(OH(2))(3)(CO)(3)](+) approximately 3-fold. Thus, ibogaine directly labeled with (99m)Tc-tricarbonyl is not suitable for CNS imaging because of its poor uptake. Brain transport is not restricted by efflux transporters but is reduced by its lipophilicity and interaction with the membrane-positive dipole potential. 2009 Wiley-Liss, Inc. and the American Pharmacists Association

  16. Radionuclide imaging of myocardial infarction using Tc-99m TBI

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Holman, B.L.; Campbell, S.; Kirshenbaum, J.M.

    The cationic complex Tc-99m t-butylisonitrile (TBI) concentrates in the myocardial tissue of several animal species. Its myocardial distribution is proportional to blood flow both in zones of ischemia and in normal myocardium at rest. Planar, tomographic, and gated myocardial images have been obtained using Tc-99m TBI in the human. The authors investigated the potential application of Tc-99m TBI imaging to detect and localize myocardial infarction. Four subjects without clinical evidence of cardiovascular disease and five patients with ECG evidence of previous myocardial infarction were studied. Tc-99m TBI (10mCi) was injected intravenously with the patient in a resting state with planarmore » imaging in the anterior, 30 and 70 degree LAO projections beginning one hr after injection. The distribution of the tracer was homogeneous throughout the left ventricular wall in the normal subjects. Regional perfusion defects were present in 4/5 of the patients with myocardial infarction. Location of the defects corresponded to the location of the infarct using ECG criteria (2 inferoposterior and 2 anterior). The patient in whom the Tc-99m TBI image appeared normal had sustained a subendocardial myocardial infarct which could not be localized by ECG; the other 4 pts had transmural infarcts. Anterior and 30 degree LAO images were of excellent quality in all cases; there was overlap of the liver on the inferior wall of the left ventricle on the 70 degree LAO views. The authors conclude that accurate perfusion imaging may be possible using Tc-99m TBI in patients with transmural myocardial infarction.« less

  17. Rugged Low-Resistance Contacts To High-Tc Superconductors

    NASA Technical Reports Server (NTRS)

    Caton, Randall; Selim, Raouf; Byvik, Charles E.; Buoncristiani, A. Martin

    1992-01-01

    Newly developed technique involving use of gold makes possible to fabricate low-resistance contacts with rugged connections to high-Tc superconductors. Gold diffused into specimen of superconducting material by melting gold beads onto surface of specimen, making strong mechanical contacts. Shear strength of gold bead contacts greater than epoxy or silver paste. Practical use in high-current-carrying applications of new high-Tc materials, including superconducting magnets, long-wavelength sensors, electrical ground planes at low temperatures, and efficient transmission of power.

  18. The inducible costimulator augments Tc17 cell responses to self and tumor tissue

    PubMed Central

    Nelson, Michelle H.; Kundimi, Sreenath; Bowers, Jacob S.; Rogers, Carolyn E.; Huff, Logan W.; Schwartz, Kristina M.; Thyagarajan, Krishnamurthy; Little, Elizabeth C.; Mehrotra, Shikhar; Cole, David J.; Rubinstein, Mark P.; Paulos, Chrystal M.

    2014-01-01

    The inducible costimulator (ICOS) plays a key role in CD4+ Th17 cell development, but its role in CD8+ Tc17 cell development and self/tumor immunity remains unknown. We found that ICOS co-stimulation was important for the functional maintenance but not differentiation of Tc17 cells in vitro. Blocking the ICOS pathway using an antagonist antibody or by using mice genetically deficient in the ICOS ligand (ICOSL) reduced the antitumor activity of adoptively transferred Tc17 cells. Conversely, activating Tc17 cells with an ICOS agonist in vitro enhanced their capacity to eradicate melanoma and induce autoimmune vitiligo when infused into mice. However, ICOS stimulation did not augment the antitumor activity of IL-2 expanded T cells. Additional investigation revealed that ICOS stimulation not only increased IL-2Rα, CXCR3 and IL-23R expression on Tc17 cells, but also dampened their expression of suppressive molecule CD39. Although Tc17 cells activated with an ICOS agonist co-secreted heightened IL-17A, IL-9 and IFN-γ, their therapeutic effectiveness was critically dependent on IFN-γ production. Depletion of IL-17A and IL-9 had little impact of antitumor Tc17 cells activated with an ICOS agonist. Collectively, our work reveals that the ICOS pathway potentiates the antitumor activity of adoptively transferred Tc17 cells. This work has major implications for the design of vaccine, antibody and cell-based therapies for autoimmunity, infectious disease and cancer. PMID:25576595

  19. A variant Tc4 transposable element in the nematode C. elegans could encode a novel protein.

    PubMed Central

    Li, W; Shaw, J E

    1993-01-01

    A variant C. elegans Tc4 transposable element, Tc4-rh1030, has been sequenced and is 3483 bp long. The Tc4 element that had been analyzed previously is 1605 bp long, consists of two 774-bp nearly perfect inverted terminal repeats connected by a 57-bp loop, and lacks significant open reading frames. In Tc4-rh1030, by comparison, a 2343-bp novel sequence is present in place of a 477-bp segment in one of the inverted repeats. The novel sequence of Tc4-rh1030 is present about five times per haploid genome and is invariably associated with Tc4 elements; we have used the designation Tc4v to denote this variant subfamily of Tc4 elements. Sequence analysis of three cDNA clones suggests that a Tc4v element contains at least five exons that could encode a novel basic protein of 537 amino acid residues. On northern blots, a 1.6-kb Tc4v-specific transcript was detected in the mutator strain TR679 but not in the wild-type strain N2; Tc4 elements are known to transpose in TR679 but appear to be quiescent in N2. We have analyzed transcripts produced by an unc-33 gene that has the Tc4-rh1030 insertional mutation in its transcribed region; all or almost all of the Tc4v sequence is frequently spliced out of the mutant unc-33 transcripts, sometimes by means of non-consensus splice acceptor sites. Images PMID:8382791

  20. Chlamydia muridarum with Mutations in Chromosomal Genes tc0237 and/or tc0668 Is Deficient in Colonizing the Mouse Gastrointestinal Tract

    PubMed Central

    Shao, Lili; Zhang, Tianyuan; Liu, Quanzhong; Wang, Jie

    2017-01-01

    ABSTRACT Chlamydiae colonize the gastrointestinal tracts of both animals and humans. However, their medical significance remains unknown. We have previously shown that wild-type Chlamydia muridarum spreads to and establishes stable colonization of the gastrointestinal tract following intravaginal inoculation. In the present study, we found that C. muridarum with mutations in chromosomal genes tc0237 and/or tc0668 was defective in spreading to the mouse gastrointestinal tract, which correlated with its attenuated pathogenicity in the upper genital tract. This correlation was more consistent than that of chlamydial pathogenicity with ascending infection in the genital tract, since attenuated C. muridarum spread significantly less to the gastrointestinal tract but maintained robust ascending infection of the upper genital tract. Transcervical inoculation further confirmed the correlation between C. muridarum spreading to the gastrointestinal tract and its pathogenicity in the upper genital tract. Finally, defective spreading of C. muridarum mutants was due to their inability to colonize the gastrointestinal tract since intragastric inoculation did not rescue the mutants' colonization. Thus, promoting C. muridarum colonization of the gastrointestinal tract may represent a primary function of the TC0237 and TC0668 proteins. Correlation of chlamydial colonization of the gastrointestinal tract with chlamydial pathogenicity in the upper genital tract suggests a potential role for gastrointestinal chlamydiae in genital tract pathogenicity. PMID:28584162

  1. Radiation dose in 320-slice multidetector cardiac CT: a single center experience of evolving dose minimization.

    PubMed

    Tung, Matthew K; Cameron, James D; Casan, Joshua M; Crossett, Marcus; Troupis, John M; Meredith, Ian T; Seneviratne, Sujith K

    2013-01-01

    Minimization of radiation exposure remains an important subject that occurs in parallel with advances in scanner technology. We report our experience of evolving radiation dose and its determinants after the introduction of 320-multidetector row cardiac CT within a single tertiary cardiology referral service. Four cohorts of consecutive patients (total 525 scans), who underwent cardiac CT at defined time points as early as 2008, are described. These include a cohort just after scanner installation, after 2 upgrades of the operating system, and after introduction of an adaptive iterative image reconstruction algorithm. The proportions of nondiagnostic coronary artery segments and studies with nondiagnostic segments were compared between cohorts. Significant reductions were observed in median radiation doses in all cohorts compared with the initial cohort (P < .001). Median dose-length product fell from 944 mGy · cm (interquartile range [IQR], 567.3-1426.5 mGy · cm) to 156 mGy · cm (IQR, 99.2-265.0 mGy · cm). Although the proportion of prospectively triggered scans has increased, reductions in radiation dose have occurred independently of distribution of scan formats. In multiple regression that combined all groups, determinants of dose-length product were tube output, the number of cardiac cycles scanned, tube voltage, scan length, scan format, body mass index, phase width, and heart rate (adjusted R(2) = 0.85, P < .001). The proportion of nondiagnostic coronary artery segments was slightly increased in group 4 (2.9%; P < .01). While maintaining diagnostic quality in 320-multidetector row cardiac CT, the radiation dose has decreased substantially because of a combination of dose-reduction protocols and technical improvements. Continued minimization of radiation dose will increase the potential for cardiac CT to expand as a cardiac imaging modality. Copyright © 2013 Society of Cardiovascular Computed Tomography. Published by Elsevier Inc. All rights reserved.

  2. Experimental evidences of 95 mTc production in a nuclear reactor.

    PubMed

    Cohen, I M; Robles, A; Mendoza, P; Airas, R M; Montoya, E H

    2018-05-01

    95 m Tc has been identified as by-product in some solutions of 99 m Tc obtained by irradiation of molybdenum trioxide in a reactor neutron flux. The characterization was carried out using both measurements by gamma spectrometry and half-life determination. The possible ways that lead to the 95 m Tc production in a nuclear reactor are discussed. Copyright © 2018. Published by Elsevier Ltd.

  3. Mass estimate and close approaches of near-Earth asteroid 2015 TC25

    NASA Astrophysics Data System (ADS)

    Farnocchia, Davide; Tholen, David J.; Micheli, Marco; Ryan, William; Rivera-Valentin, Edgard G.; Taylor, Patrick A.; Giorgini, Jon D.

    2017-10-01

    Near-Earth asteroid 2015 TC25 was discovered by the Catalina Sky Survey in October 2015, just two days before an Earth flyby at 0.3 lunar distances. By using ground-based optical, near-infrared, and radar assets during the flyby, Reddy et al. (2016) successfully characterized 2015 TC25. They suggested that the object has a high albedo and a diameter of 2 m, which makes 2015 TC25 one of the smallest asteroids ever detected. Moreover, the orbital information available at the end of the 2015 apparition indicated that 2015 TC25 had a probability of an Earth impact of more than 1 in 10000 from 2070 to 2115. To rule out possible impacts we recovered 2015 TC25 at the end of March 2017 and continued tracking the object through the end of April, when it became too faint to be observable. The recent 2017 astrometry clearly shows the action of solar radiation pressure on the orbit of 2015 TC25 with a 7.6-sigma detection. This solar radiation pressure estimate allows us to put constraints on the density and mass of 2015 TC25 and further suggests that the object is only a couple of meters in size. In particular, the area-to-mass ratio is between 0.6 m^2/t and 0.7 m^2/t and, for a diameter of 2 m, the density is about 1.1 g/cm^3. By accounting for the contribution of non-gravitational perturbations, we analyze the future trajectory of 2015 TC25. Based on the extended data arc, ephemeris predictions are now deterministic until the Earth close approach in 2089 and a Monte Carlo search rules out impacts for the next 100 years.

  4. OMPS TC EDR Algorithm: Improvement and Verification

    NASA Astrophysics Data System (ADS)

    Novicki, M.; Sen, B.; Hao, X.; Qu, J. J.

    2009-12-01

    The Ozone Mapper and Profiler Suite (OMPS) is scheduled to be launched on the NPOESS Preparatory Project (NPP) platform in early 2011. The OMPS will continue monitoring ozone from space, using three instruments, namely the Total Column Mapper (heritage: TOMS), the Nadir Profiler (heritage: SBUV) and the Limb Profiler (heritage: SOLSE/LORE). The Total Column Mapper (TC) sensor images the Earth through a slit, nadir-cell horizontally spaced at 49.5 km cross-track with an along-track reporting interval of 50 km. The total field of view (FOV) cross track is 110 degrees to provide daily global coverage. The TC sensor, a grating spectrometer, provides 0.45 nm spectral sampling across the wavelength range of 300-380 nm. The calibration stability, which is essential to enable long-term ozone monitoring, is maintained by periodic observations of the Sun, using a diffuser to redirect the solar irradiance into the sensor. We describe the data analysis method being presently implemented to retrieve the total column ozone Earth Data Record (EDR) from the radiance data measured by the TC sensor. We discuss the software changes, the test data used to verify the functional performance and the test results.

  5. Radiopharmaceutical considerations for using Tc-99m MAA in lung transplant patients.

    PubMed

    Ponto, James A

    2010-01-01

    To elucidate radiopharmaceutical considerations for using technetium Tc-99m albumin aggregated (Tc-99m MAA) in lung transplant patients and to establish an appropriate routine dose and preparation procedure. Tertiary care academic hospital during May 2007 to May 2009. Nuclear pharmacist working in nuclear medicine department. Radiopharmaceutical considerations deemed important for the use of Tc-99m MAA in lung transplant patients included radioactivity dose, particulate dose, rate of the radiolabeling reaction (preparation time), and final radiochemical purity. Evaluation of our initial 12-month experience, published literature, and professional practice guidelines provided the basis for establishing an appropriate dose and preparation procedure of Tc-99m MAA for use in lung transplant patients. Radiochemical purity at typical incubation times and image quality in subsequent lung transplant patients imaged during the next 12 months. Based on considerations of radioactivity dose, particulate dose, rate of the radiolabeling reaction (preparation time), and final radiochemical purity, a routine dose consisting of 3 mCi (111 MBq) and 100,000 particles of Tc-99m MAA for planar perfusion lung imaging of adult lung transplant patients was established as reasonable and appropriate. MAA kits were prepared with a more reasonable amount of Tc-99m and yielded high radiochemical purity values in typical incubation times. Images have continued to be of high diagnostic quality. Tc-99m MAA used for lung transplant imaging can be readily prepared with high radiochemical purity to provide a dose of 3 mCi (111 GBq)/100,000 particles, which provides images of high diagnostic quality.

  6. Origin of the pressure-dependent Tc valley in superconducting simple cubic phosphorus

    NASA Astrophysics Data System (ADS)

    Wu, Xianxin; Jeschke, Harald O.; Di Sante, Domenico; von Rohr, Fabian O.; Cava, Robert J.; Thomale, Ronny

    2018-03-01

    Motivated by recent experiments, we investigate the pressure-dependent electronic structure and electron-phonon (e-ph) coupling for simple cubic phosphorus by performing first-principles calculations within the full potential linearized augmented plane-wave method. As a function of increasing pressure, our calculations show a valley feature in Tc, followed by an eventual decrease for higher pressures. We demonstrate that this Tc valley at low pressures is due to two nearby Lifshitz transitions, as we analyze the band-resolved contributions to the e-ph coupling. Below the first Lifshitz transition, the phonon hardening and shrinking of the γ Fermi surface with s -orbital character results in a decreased Tc with increasing pressure. After the second Lifshitz transition, the appearance of δ Fermi surfaces with 3 d -orbital character generate strong e-ph interband couplings in α δ and β δ channels, and hence lead to an increase of Tc. For higher pressures, the phonon hardening finally dominates, and Tc decreases again. Our study reveals that the intriguing Tc valley discovered in experiment can be attributed to Lifshitz transitions, while the plateau of Tc detected at intermediate pressures appears to be beyond the scope of our analysis. This strongly suggests that aside from e-ph coupling, electronic correlations along with plasmonic contributions may be relevant for simple cubic phosphorus. Our findings hint at the notion that increasing pressure can shift the low-energy orbital weight towards d character, and as such even trigger an enhanced importance of orbital-selective electronic correlations despite an increase of the overall bandwidth.

  7. Dependence of Tc on the q -ω structure of the spin-fluctuation spectrum

    NASA Astrophysics Data System (ADS)

    Dahm, Thomas; Scalapino, D. J.

    2018-05-01

    A phenomenological spin-fluctuation analysis [Dahm et al., Nat. Phys. 5, 217 (2009), 10.1038/nphys1180], based upon inelastic neutron scattering (INS) and angular resolved photoemission spectroscopy (ARPES) data for YBCO6.6(Tc=61 K) , is used to calculate the functional derivative of the d -wave eigenvalue λd of the linearized gap equation with respect to the imaginary part of the spin susceptibility χ''(q ,ω ) at 70 K. For temperatures near Tc, the variation of Tc with respect to χ''(q ,ω ) is proportional to this functional derivative. We find that above an energy ˜4 Tc the functional derivative becomes positive so that adding spin-fluctuation spectral weight at higher frequencies leads to an increase in Tc. The strongest pairing occurs for large momentum transfers, and small momentum spin-fluctuations suppress the pairing.

  8. Limitations and pitfalls of 99mTc-EDDA/HYNIC-TOC (Tektrotyd) scintigraphy.

    PubMed

    Garai, Ildikó; Barna, Sandor; Nagy, Gabor; Forgacs, Attila

    2016-01-01

    Tektrotyd kit was developed by Polatom company for 99mTc labeling to make an alternative tracer of somatostatin receptor scintigraphy available. Since 2005, 99mTc-EDDA/HYNIC-Tyr3-Octreotide has been used in clinical imaging and achieved high impact in management of patients with neuroendocrine tumors. Knowing the limitations and pitfalls is essential to provide ac-curate diagnosis. Therefore, the potential pitfalls associated with the use of 99mTc-EDDA/HYNIC-TOC are reviewed on the basis of own experience. Data were analyzed of 310 patients who underwent somatostatin receptor scintigraphy with 99mTc-Tektrotyd. Pitfalls during radiolabeling process or acquisition can worsen the sensitivity of SRS (somatostatin receptor scintigraphy). Recognizing physi-ological and clinical pitfalls, the diagnostic accuracy will improve.

  9. The Joint Strength and Fracture Mechanisms of TC4/TC4 and TA0/TA0 Brazed with Ti-25Cu-15Ni Braze Alloy

    NASA Astrophysics Data System (ADS)

    Zou, Zhihuan; Zeng, Fanhao; Wu, Haobo; Liu, Jian; Li, Yi; Gu, Yi; Yuan, Tiechui; Zhang, Fuqin

    2017-05-01

    In this paper, Ti-25Cu-15Ni (mass ratio) braze alloys were prepared by vacuum arc melting. Additionally, the TA0 pure titanium and TC4 titanium alloy were brazed with the Ti-25Cu-15Ni braze alloy at 960, 980, 1000, 1020, and 1040 °C. The effects of the braze temperature on the tensile strength of the TA0 and TC4 joints and their fracture mechanisms were studied. The maximum tensile strength of the TA0 joints of 219.9 ± 0.1 MPa was achieved at a brazing temperature of 980 °C, and the maximum tensile strength of the TC4 joints of 832.9 ± 0.1 MPa was achieved at the same brazing temperature. These results indicate that their ideal joint strength is comparable. According to the fractography results of the TA0 joints, a mixed fracture morphology is indicated. The TA0 fracture surface is dominated by cleavage fracture with a small contribution from ductile fracture. The TC4 joint fracture arises from cleavage.

  10. Reduction and Simultaneous Removal of 99 Tc and Cr by Fe(OH) 2 (s) Mineral Transformation

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Saslow, Sarah A.; Um, Wooyong; Pearce, Carolyn I.

    Technetium (Tc) remains a priority remediation concern due to persistent challenges, including rapid re-oxidation of immobilized Tc, and competing contaminants, e.g. Cr(VI), that inhibit targeted Tc reduction and incorporation into stable mineral phases. Here Fe(OH) 2(s) is investigated as a comprehensive solution for overcoming these challenges, by serving as both the reductant, (Fe(II)), and immobilization agent to form Tc-incorporated magnetite (Fe 3O 4). Trace metal analysis suggests removal of Tc(VII) and Cr(VI) from solution occurs simultaneously; however, complete removal and reduction of Cr(VI) is achieved earlier than the removal/reduction of co-mingled Tc(VII). Bulk oxidation state analysis of the magnetite solidmore » phase by XANES confirms that the majority of Tc is Tc(IV), which is corroborated by XPS. Furthermore, EXAFS results show successful Tc(IV) incorporation into magnetite octahedral sites without additional substitution of Cr or Tc into neighboring Fe octahedral sites. XPS analysis of Cr confirms reduction to Cr(III) and the formation of a Cr-incorporated spinel, Cr2O 3, and Cr(OH)3 phases. Spinel (modeled as Fe 3O 4), goethite, and feroxyhyte are detected in all reacted solid phase samples analyzed by XRD, where Tc(IV) incorporation has little effect on the spinel lattice structure. In the presence of Cr(III) a spinel phase along the magnetite-chromite (Fe 3O 4-FeCr 2O 4) solid-solution line is formed.« less

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

    PubMed Central

    2013-01-01

    Background Arabidopsis thaliana (Arabidopsis) NON-EXPRESSOR OF PR1 (NPR1) is a transcription coactivator that plays a central role in regulating the transcriptional response to plant pathogens. Developing flowers of homozygous npr3 mutants are dramatically more resistant to infection by the pathogenic bacterium Pseudomonas syringae, suggesting a role of NPR3 as a repressor of NPR1-mediated defense response with a novel role in flower development. Results We report here the characterization of a putative NPR3 gene from the tropical tree species Theobroma cacao (TcNPR3). Like in Arabidopsis, TcNPR3 was constitutively expressed across a wide range of tissue types and developmental stages but with some differences in relative levels compared to Arabidopsis. To test the function of TcNPR3, we performed transgenic complementation analysis by introducing a constitutively expressing putative TcNPR3 transgene into an Arabidopsis npr3 mutant. TcNPR3 expressing Arabidopsis plants were partially restored to the WT pathogen phenotype (immature flowers susceptible to bacterial infection). To test TcNPR3 function directly in cacao tissues, a synthetic microRNA targeting TcNPR3 mRNA was transiently expressed in cacao leaves using an Agrobacterium-infiltration method. TcNPR3 knock down leaf tissues were dramatically more resistance to infection with Phytophthora capsici in a leaf bioassay, showing smaller lesion sizes and reduced pathogen replication. Conclusions We conclude that TcNPR3 functions similar to the Arabidopsis NPR3 gene in the regulation of the cacao defense response. Since TcNPR3 did not show a perfect complementation of the Arabidopsis NPR3 mutation, the possibility remains that other functions of TcNPR3 remain to be found. This novel knowledge can contribute to the breeding of resistant cacao varieties against pathogens through molecular markers based approaches or biotechnological strategies. PMID:24314063

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

    PubMed

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

    2013-12-06

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

  13. Sternal uptake of 99mTc-MAA in thoracic outlet syndrome.

    PubMed

    Matsusaka, Yohji; Nakahara, Tadaki; Iwabuchi, Yu; Kameyama, Masashi; Murakami, Koji

    2015-12-01

    Tc-macroaggregated albumin (MAA) uptake in the vertebrae has been reported in central vein occlusion, although its sternal uptake is rarely seen. We present a case in which Tc-MAA SPECT/CT showed spotty uptake in the sternum. Contrast-enhanced CT revealed marked narrowing of the left subclavian vein at the thoracic outlet with a developed collateral vein running, in the left anterior chest subcutaneous tissue, between the sternum and left axilla. In this case, IV injection of Tc-MAA from the left forearm probably led to bone marrow uptake in the sternum due to retrograde venous flow through the collateral vein.

  14. 99mTc-EDDA/HYNIC-TOC in the management of medullary thyroid carcinoma.

    PubMed

    Parisella, Maria; D'Alessandria, Calogero; van de Bossche, Bieke; Chianelli, Marco; Ronga, Giuseppe; Papini, Enrico; Mikolajczak, Renata; Letizia, Claudio; De Toma, Giorgio; Veneziani, Augusto; Scopinaro, Francesco; Signore, Alberto

    2004-04-01

    An early diagnosis of distant metastases or local recurrences of medullary thyroid carcinoma (MTC) can be achieved by several conventional radiological modalities (e.g., ultrasonography, computed tomography [CT], and magnetic resonance imaging [MRI] as well as by radioisotopic procedures, such as positron emission tomography (PET), scintigraphy with different types of radiopharmaceuticals, and radiolabeled receptor-ligands in particular. The aim of this study was to evaluate the clinical utility of 99mTc-EDDA/HYNIC-TOC, a new octreotide derivative, to detect recurrences of disease or distant metastases in MTC. Images obtained of 5 patients with high levels of serum calcitonin were compared to findings obtained with other diagnostic procedures: 111In-octreotide, 99mTc-DMSA-V, 18F-flouro-D-deoxyglucose-PET, and CT/MRI. 99mTc-EDDA/HYNIC-TOC was positive in all patients and showed 15 areas of pathological uptake in the cervical and mediastinal regions. 111In-octreotide was positive in 3 of 3 patients and showed 4 areas, compared to 8 of 99mTc-EDDA/HYNIC-TOC. 99mTc-V-DMSA was positive in 3 of 4 patients but showed 6 pathological areas, compared to 13 of 99mTc-EDDA/HYNIC-TOC. 18F-FDG-PET was positive in 5 of 5 patients but showed only 11 areas, compared to 15 of 99mTc-EDDA/HYNIC-TOC. The CT scan was positive in only 2 patients. In conclusion, 99mTc-EDDA/HYNIC-TOC detected more sites of pathological uptake than other modalities, showed better imaging properties than 111In-octreotide, and might be the radiopharmaceutical of choice for providing a rationale for radioisotopic therapy.

  15. Evaluation of hepatic function with (99m)Tc-galactosylated serum albumin scintigraphy in patients with malaria: comparison with (99m)Tc-colloid scintigraphy and liver ultrasonography.

    PubMed

    Lee, Sang-Woo; Lee, Jaetae; Lee, Deog-Young; Chun, Kyung-Ah; Ahn, Byeong-Cheol; Kang, Young-Mo; Lee, Kyubo

    2007-02-01

    Malarial parasites injected by the mosquito rapidly target hepatocytes, and hepatomegaly is commonly observed during the progress of the disease in malaria patients. To evaluate the degree of hepatic damage and functional status of hepatocytes in malaria patients, we performed liver scintigraphy using (99m)Tc-galactosylated serum albumin (GSA) prospectively and the findings were compared with those of (99m)Tc-colloid scintigraphy, ultrasonography and clinical results in the same subject. Eight malaria patients (all male, mean age 22 years) confirmed to be infected with Plasmodium vivax underwent (99m)Tc-GSA liver scintigraphy, followed by liver ultrasonography and (99m)Tc-colloid scintigraphy using phytate within 3 days. For hepatocyte scintigraphy, anterior images of cardiac blood-pool and liver were continuously acquired for 30 min after injection of 185 MBq (99m)Tc-GSA (3 mg). In addition to visual interpretation of the images, quantitative measurement of hepatic function was performed with several functional parameters, such as hepatic uptake index (LHL15), blood clearance index (HH15) and modified receptor index (LHL/HH) calculated from the radioactivity of the liver and heart. (99m)Tc-colloid images were assessed and graded visually. Severity of hepatic dysfunction or reticuloendothelial system activation was classified as normal, mild, moderate and severe on GSA or colloid images. Hepatomegaly was observed in five and splenomegaly in seven of the eight patients. Serum levels of transaminase and alkaline phosphatase were mildly elevated in two. Visual assessment of GSA scintigraphy revealed normal findings in all subjects, except for mild increases in size. The mean values of LHL15, HH15 and LHL/HH were 0.928+/-0.014, 0.537+/-0.031 and 1.732+/-0.106, respectively. They were graded as normal in five, and near-normal to mild dysfunction in three subjects. In contrast, (99m)Tc-colloid scintigraphy revealed abnormal findings in all of the subjects, and graded as

  16. Blunt cerebrovascular injury screening with 64-channel multidetector computed tomography: more slices finally cut it.

    PubMed

    Paulus, Elena M; Fabian, Timothy C; Savage, Stephanie A; Zarzaur, Ben L; Botta, Vandana; Dutton, Wesley; Croce, Martin A

    2014-02-01

    Aggressive screening to diagnose blunt cerebrovascular injury (BCVI) results in early treatment, leading to improved outcomes and reduced stroke rates. While computed tomographic angiography (CTA) has been widely adopted for BCVI screening, evidence of its diagnostic sensitivity is marginal. Previous work from our institution using 32-channel multidetector CTA in 684 patients demonstrated an inadequate sensitivity of 51% (Ann Surg. 2011,253: 444-450). Digital subtraction angiography (DSA) continues to be the reference standard of diagnosis but has significant drawbacks of invasiveness and resource demands. There have been continued advances in CT technology, and this is the first report of an extensive experience with 64-channel multidetector CTA. Patients screened for BCVI using CTA and DSA (reference) at a Level 1 trauma center during the 12-month period ending in May 2012 were identified. Results of CTA and DSA, complications, and strokes were retrospectively reviewed and compared. A total of 594 patients met criteria for BCVI screening and underwent both CTA and DSA. One hundred twenty-eight patients (22% of those screened) had 163 injured vessels: 99 (61%) carotid artery injuries and 64 (39%) vertebral artery injuries. Sixty-four-channel CTA demonstrated an overall sensitivity per vessel of 68% and specificity of 92%. The 52 false-negative findings on CTA were composed of 34 carotid artery injuries and 18 vertebral artery injuries; 32 (62%) were Grade I injuries. Overall, positive predictive value was 36.2%, and negative predictive value was 97.5%. Six procedure-related complications (1%) occurred with DSA, including two iatrogenic dissections and one stroke. Sixty-four-channel CTA demonstrated a significantly improved sensitivity of 68% versus the 51% previously reported for the 32-channel CTA (p = 0.0075). Sixty-two percent of the false-negative findings occurred with low-grade injuries. Considering complications, cost, and resource demand associated with

  17. [Assessment of myocardial perfusion and left ventricular function with 99mTc-PPN 1011].

    PubMed

    Kumita, S; Mizumura, S; Oishi, T; Kumazaki, T; Sano, J; Yamazaki, Y; Munakata, K

    1993-04-01

    First-pass radionuclide angiography (FPRNA) was performed with the new myocardial perfusion agent 99mTc-1,2,bis[bis(2-ethoxyethyl)phosphino] ethane (99mTc-PPN 1011) on stress and at rest. One hour after that, myocardial perfusion was counted by 99mTc-PPN 1011 SPECT. Left ventricular ejection fraction (LVEF) obtained by FPRNA correlated with that by multigated image with 99mTc-HSAD (r = 0.94, n = 11). The reduction of left ventricular function under the exercise (delta LVEF) and the increase of severity score (delta Severity score) have a good relation (r = 0.88) in 7 patients with prior myocardial infarction. Thus 99mTc-PPN 1011 appears to be an ideal radiopharmaceutical for evaluation of ventricular function and myocardial perfusion.

  18. Assessment of bronchial wall thickness and lumen diameter in human adults using multi-detector computed tomography: comparison with theoretical models

    PubMed Central

    Montaudon, M; Desbarats, P; Berger, P; de Dietrich, G; Marthan, R; Laurent, F

    2007-01-01

    A thickened bronchial wall is the morphological substratum of most diseases of the airway. Theoretical and clinical models of bronchial morphometry have so far focused on bronchial lumen diameter, and bronchial length and angles, mainly assessed from bronchial casts. However, these models do not provide information on bronchial wall thickness. This paper reports in vivo values of cross-sectional wall area, lumen area, wall thickness and lumen diameter in ten healthy subjects as assessed by multi-detector computed tomography. A validated dedicated software package was used to measure these morphometric parameters up to the 14th bronchial generation, with respect to Weibel's model of bronchial morphometry, and up to the 12th according to Boyden's classification. Measured lumen diameters and homothety ratios were compared with theoretical values obtained from previously published studies, and no difference was found when considering dichotomic division of the bronchial tree. Mean wall area, lumen area, wall thickness and lumen diameter were then provided according to bronchial generation order, and mean homothety ratios were computed for wall area, lumen area and wall thickness as well as equations giving the mean value of each parameter for a given bronchial generation with respect to its value in generation 0 (trachea). Multi-detector computed tomography measurements of bronchial morphometric parameters may help to improve our knowledge of bronchial anatomy in vivo, our understanding of the pathophysiology of bronchial diseases and the evaluation of pharmacological effects on the bronchial wall. PMID:17919291

  19. Detection of atherosclerotic plaques in ApoE-deficient mice using (99m)Tc-duramycin.

    PubMed

    Liu, Zhonglin; Larsen, Brandon T; Lerman, Lilach O; Gray, Brian D; Barber, Christy; Hedayat, Ahmad F; Zhao, Ming; Furenlid, Lars R; Pak, Koon Y; Woolfenden, James M

    2016-08-01

    Apoptosis of macrophages and smooth muscle cells is linked to atherosclerotic plaque destabilization. The apoptotic cascade leads to exposure of phosphatidylethanolamine (PE) on the outer leaflet of the cell membrane, thereby making apoptosis detectable using probes targeting PE. The objective of this study was to exploit capabilities of a PE-specific imaging probe, (99m)Tc-duramycin, in localizing atherosclerotic plaque and assessing plaque evolution in apolipoprotein-E knockout (ApoE(-/-)) mice. Atherosclerosis was induced in ApoE(-/-) mice by feeding an atherogenic diet. (99m)Tc-duramycin images were acquired using a small-animal SPECT imager. Six ApoE(-/-) mice at 20weeks of age (Group I) were imaged and then sacrificed for ex vivo analyses. Six additional ApoE(-/-) mice (Group II) were imaged at 20 and 40weeks of age before sacrifice. Six ApoE wild-type (ApoE(+/+)) mice (Group III) were imaged at 40weeks as controls. Five additional ApoE(-/-) mice (40weeks of age) (Group IV) were imaged with a (99m)Tc-labeled inactive peptide, (99m)Tc-LinDUR, to assess (99m)Tc-duramycin targeting specificity. Focal (99m)Tc-duramycin uptake in the ascending aorta and aortic arch was detected at 20 and 40weeks in the ApoE(-/-) mice but not in ApoE(+/+) mice. (99m)Tc-duramycin uptake in the aortic lesions increased 2.2-fold on quantitative imaging in the ApoE(-/-) mice between 20 and 40weeks. Autoradiographic and histological data indicated significantly increased (99m)Tc-duramycin uptake in the ascending aorta and aortic arch associated with advanced plaques. Quantitative autoradiography showed that the ratio of activity in the aortic arch to descending thoracic aorta, which had no plaques or radioactive uptake, was 2.1 times higher at 40weeks than at 20weeks (6.62±0.89 vs. 3.18±0.29, P<0.01). There was barely detectable focal uptake of (99m)Tc-duramycin in the aortic arch of ApoE(+/+) mice. No detectable (99m)Tc-LinDUR uptake was observed in the aortas of ApoE(-/-) mice. PE

  20. 99Tc and Re incorporated into metal oxide polyoxometalates: oxidation state stability elucidated by electrochemistry and theory.

    PubMed

    McGregor, Donna; Burton-Pye, Benjamin P; Mbomekalle, Israel M; Aparicio, Pablo A; Romo, Susanna; López, Xavier; Poblet, Josep M; Francesconi, Lynn C

    2012-08-20

    The radioactive element technetium-99 ((99)Tc, half-life = 2.1 × 10(5) years, β(-) of 253 keV), is a major byproduct of (235)U fission in the nuclear fuel cycle. (99)Tc is also found in radioactive waste tanks and in the environment at National Lab sites and fuel reprocessing centers. Separation and storage of the long-lived (99)Tc in an appropriate and stable waste-form is an important issue that needs to be addressed. Considering metal oxide solid-state materials as potential storage matrixes for Tc, we are examining the redox speciation of Tc on the molecular level using polyoxometalates (POMs) as models. In this study we investigate the electrochemistry of Tc complexes of the monovacant Wells-Dawson isomers, α(1)-P(2)W(17)O(61)(10-) (α1) and α(2)-P(2)W(17)O(61)(10-) (α2) to identify features of metal oxide materials that can stabilize the immobile Tc(IV) oxidation state accessed from the synthesized Tc(V)O species and to interrogate other possible oxidation states available to Tc within these materials. The experimental results are consistent with density functional theory (DFT) calculations. Electrochemistry of K(7-n)H(n)[Tc(V)O(α(1)-P(2)W(17)O(61))] (Tc(V)O-α1), K(7-n)H(n)[Tc(V)O(α(2)-P(2)W(17)O(61))] (Tc(V)O-α2) and their rhenium analogues as a function of pH show that the Tc-containing derivatives are always more readily reduced than their Re analogues. Both Tc and Re are reduced more readily in the lacunary α1 site as compared to the α2 site. The DFT calculations elucidate that the highest oxidation state attainable for Re is VII while, under the same electrochemistry conditions, the highest oxidation state for Tc is VI. The M(V)→ M(IV) reduction processes for Tc(V)O-α1 are not pH dependent or only slightly pH dependent suggesting that protonation does not accompany reduction of this species unlike the M(V)O-α2 (M = (99)Tc, Re) and Re(V)O-α1 where M(V/IV) reduction process must occur hand in hand with protonation of the terminal M═O to

  1. In situ Spectroscopic Analysis and Quantification of [Tc(CO)3]+ in Hanford Tank Waste.

    PubMed

    Branch, Shirmir D; French, Amanda D; Lines, Amanda M; Soderquist, Chuck Z; Rapko, Brian M; Heineman, William R; Bryan, Samuel A

    2018-06-12

    The quantitative conversion of non-pertechnetate [Tc(CO)3]+ species in nuclear waste storage tank 241-AN-102 at the Hanford Site is demonstrated. A waste sample containing the [Tc(CO)3]+ species is added to a developer solution that rapidly converts the non-emissive species into a luminescent complex, which is detected spectroscopically. This method was first demonstrated using a [Tc(CO)3]+ sample non-waste containing matrix to determine a detection limit (LOD), resulting in a [Tc(CO)3]+ LOD of 2.20 × 10-7 M, very near the LOD of the independently synthesized standard (2.10 × 10-7 M). The method was then used to detect [Tc(CO)3]+ in a simulated waste using the standard addition method, resulting in a [Tc(CO)3]+ concentration of 1.89 × 10-5 M (within 27.7% of the concentration determined by β- liquid scintillation counting). Three samples from 241-AN-102 were tested by the standard addition method: (1) a 5 M Na adjusted fraction, (2) a fraction depleted of 137Cs, (3) and an acid-stripped eluate. The concentrations of [Tc(CO)3]+ in these fractions were determined to be 9.90 × 10-6 M (1), 0 M (2), and 2.46 × 10-6 M (3), respectively. The concentration of [Tc(CO)3]+ in the as-received AN-102 tank waste supernatant was determined to be 1.84 × 10-5 M.

  2. Sorption of99mTc radiopharmaceutical compounds by soils

    USGS Publications Warehouse

    Jurisson, S.; Gawenis, J.; Landa, E.R.

    2004-01-01

    Study of the sorption of 99mTc radiopharmaceutical compounds by soils has assessed the fate of these compounds in the event of a surface spill and examined the potential of these compounds as hydrologic tracers. Sorption from deionized water, filtered Missouri River water, and artificial seawater by five surface soils was investigated. For all water types, the Tc radiopharmaceutical compounds showed greater sorption than the uncomplexed pertechnetate. The most lipophilic complexes showed the highest sorption on soils.

  3. A search for technetium (Tc II) in barium stars

    NASA Technical Reports Server (NTRS)

    Little-Marenin, Irene R.; Little, Stephen J.

    1987-01-01

    The authors searched without success for the lines of Tc II at 2647.02, 2610.00 and 2543.24 A in IUE spectra of the barium stars HR 5058, Omicron Vir, and Zeta Cap. The lack of Tc II implies that the observed s-process enhancements were produced more than half a million years ago and supports the suggestion that the spectral peculiarities of barium stars are probably related to the binary nature of the stars.

  4. Evaluating 99mTc Auger electrons for targeted tumor radiotherapy by computational methods.

    PubMed

    Tavares, Adriana Alexandre S; Tavares, João Manuel R S

    2010-07-01

    Technetium-99m (99mTc) has been widely used as an imaging agent but only recently has been considered for therapeutic applications. This study aims to analyze the potential use of 99mTc Auger electrons for targeted tumor radiotherapy by evaluating the DNA damage and its probability of correct repair and by studying the cellular kinetics, following 99mTc Auger electron irradiation in comparison to iodine-131 (131I) beta minus particles and astatine-211 (211At) alpha particle irradiation. Computational models were used to estimate the yield of DNA damage (fast Monte Carlo damage algorithm), the probability of correct repair (Monte Carlo excision repair algorithm), and cell kinetic effects (virtual cell radiobiology algorithm) after irradiation with the selected particles. The results obtained with the algorithms used suggested that 99mTc CKMMX (all M-shell Coster-Kroning--CK--and super-CK transitions) electrons and Auger MXY (all M-shell Auger transitions) have a therapeutic potential comparable to high linear energy transfer 211At alpha particles and higher than 131I beta minus particles. All the other 99mTc electrons had a therapeutic potential similar to 131I beta minus particles. 99mTc CKMMX electrons and Auger MXY presented a higher probability to induce apoptosis than 131I beta minus particles and a probability similar to 211At alpha particles. Based on the results here, 99mTc CKMMX electrons and Auger MXY are useful electrons for targeted tumor radiotherapy.

  5. Development of Tyrosine-Based Radiotracer 99mTc-N4-Tyrosine for Breast Cancer Imaging

    PubMed Central

    Kong, Fan-Lin; Ali, Mohammad S.; Rollo, Alex; Smith, Daniel L.; Zhang, Yinhan; Yu, Dong-Fang; Yang, David J.

    2012-01-01

    The purpose of this study was to develop an efficient way to synthesize 99mTc-O-[3-(1,4,8,11-tetraazabicyclohexadecane)-propyl]-tyrosine (99mTc-N4-Tyrosine), a novel amino acid-based radiotracer, and evaluate its potential in breast cancer gamma imaging. Precursor N4-Tyrosine was synthesized using a 5-step procedure, and its total synthesis yield was 38%. It was successfully labeled with 99mTc with high radiochemical purity (>95%). Cellular uptake of 99mTc-N4-Tyrosine was much higher than that of 99mTc-N4 and the clinical gold standard 18F-2-deoxy-2-fluoro-glucose (18F-FDG) in rat breast tumor cells in vitro. Tissue uptake and dosimetry estimation in normal rats revealed that 99mTc-N4-Tyrosine could be safely administered to humans. Evaluation in breast tumor-bearing rats showed that although 99mTc-N4-Tyrosine appeared to be inferior to 18F-FDG in distinguishing breast tumor tissue from chemical-induced inflammatory tissue, it had high tumor-to-muscle uptake ratios and could detect breast tumors clearly by planar scintigraphic imaging. 99mTc-N4-Tyrosine could thus be a useful radiotracer for use in breast tumor diagnostic imaging. PMID:22496612

  6. Thoracic Injuries in earthquake-related versus non-earthquake-related trauma patients: differentiation via Multi-detector Computed Tomography.

    PubMed

    Dong, Zhi-Hui; Yang, Zhi-Gang; Chen, Tian-Wu; Chu, Zhi-Gang; Deng, Wen; Shao, Heng

    2011-01-01

    Massive earthquakes are harmful to humankind. This study of a historical cohort aimed to investigate the difference between earthquake-related crush thoracic traumas and thoracic traumas unrelated to earthquakes using a multi-detector Computed Tomography (CT). We retrospectively compared an earthquake-exposed cohort of 215 thoracic trauma crush victims of the Sichuan earthquake to a cohort of 215 non-earthquake-related thoracic trauma patients, focusing on the lesions and coexisting injuries to the thoracic cage and the pulmonary parenchyma and pleura using a multi-detector CT. The incidence of rib fracture was elevated in the earthquake-exposed cohort (143 vs. 66 patients in the non-earthquake-exposed cohort, Risk Ratio (RR) = 2.2; p<0.001). Among these patients, those with more than 3 fractured ribs (106/143 vs. 41/66 patients, RR=1.2; p<0.05) or flail chest (45/143 vs. 11/66 patients, RR=1.9; p<0.05) were more frequently seen in the earthquake cohort. Earthquake-related crush injuries more frequently resulted in bilateral rib fractures (66/143 vs. 18/66 patients, RR= 1.7; p<0.01). Additionally, the incidence of non-rib fracture was higher in the earthquake cohort (85 vs. 60 patients, RR= 1.4; p<0.01). Pulmonary parenchymal and pleural injuries were more frequently seen in earthquake-related crush injuries (117 vs. 80 patients, RR=1.5 for parenchymal and 146 vs. 74 patients, RR = 2.0 for pleural injuries; p<0.001). Non-rib fractures, pulmonary parenchymal and pleural injuries had significant positive correlation with rib fractures in these two cohorts. Thoracic crush traumas resulting from the earthquake were life threatening with a high incidence of bony thoracic fractures. The ribs were frequently involved in bilateral and severe types of fractures, which were accompanied by non-rib fractures, pulmonary parenchymal and pleural injuries.

  7. Determination of 99Tc in fresh water using TRU resin by ICP-MS.

    PubMed

    Guérin, Nicolas; Riopel, Remi; Kramer-Tremblay, Sheila; de Silva, Nimal; Cornett, Jack; Dai, Xiongxin

    2017-10-02

    Technetium-99 ( 99 Tc) determination at trace level by inductively coupled plasma mass spectrometry (ICP-MS) is challenging because there is no readily available appropriate Tc isotopic tracer. A new method using Re as a recovery tracer to determine 99 Tc in fresh water samples, which does not require any evaporation step, was developed. Tc(VII) and Re(VII) were pre-concentrated on a small anion exchange resin (AER) cartridge from one litre of water sample. They were then efficiently eluted from the AER using a potassium permanganate (KMnO 4 ) solution. After the reduction of KMnO 4 in 2 M sulfuric acid solution, the sample was passed through a small TRU resin cartridge. Tc(VII) and Re(VII) retained on the TRU resin were eluted using near boiling water, which can be directly used for the ICP-MS measurement. The results for method optimisation, validation and application were reported. Crown Copyright © 2017. Published by Elsevier B.V. All rights reserved.

  8. Evaluation of the technical performance of novel holotranscobalamin (holoTC) assays in a multicenter European demonstration project.

    PubMed

    Morkbak, Anne L; Heimdal, Randi M; Emmens, Kathleen; Molloy, Anne; Hvas, Anne-Mette; Schneede, Joern; Clarke, Robert; Scott, John M; Ueland, Per M; Nexo, Ebba

    2005-01-01

    A commercially available holotranscobalamin (holo-TC) radioimmunoassay (RIA) (Axis-Shield, Dundee, Scotland) was evaluated in four laboratories and compared with a holoTC ELISA run in one laboratory. The performance of the holoTC RIA assay was comparable in three of the four participating laboratories. The results from these three laboratories, involving at least 20 initial runs of "low", "medium" and "high" serum-based controls (mean holoTC concentrations 34, 60 and 110 pmol/L, respectively) yielded an intra-laboratory imprecision of 6-10%. No systematic inter-laboratory deviations were observed on runs involving 72 patient samples (holoTC concentration range 10-160 pmol/L). A fourth laboratory demonstrated higher assay imprecision for control samples and systematic deviation of results for the patient samples. Measurement of holoTC by ELISA showed an imprecision of 4-5%, and slightly higher mean values for the controls (mean holoTC concentrations 40, 70 and 114 pmol/L, respectively). Comparable results were obtained for the patient samples. The long-term intra-laboratory imprecision was 12% for the holoTC RIA and 6% for the ELISA. In conclusion, it would be prudent to check the calibration and precision prior to starting to use these holoTC assays in research or clinical practice. The results obtained using the holoTC RIA were similar to those obtained using the holoTC ELISA assay.

  9. (99m)Tc-HYNIC-TOC scintigraphy in evaluation of active Graves' ophthalmopathy (GO).

    PubMed

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

    2007-06-01

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

  10. High Tc superconducting films from metallo-organic precursors

    NASA Astrophysics Data System (ADS)

    Davison, W. W.; Shyu, S. G.; Buchanan, R. C.

    High Tc superconducting films of heavy metal soaps (derived from carboxylic acid precursors) have been prepared on Si and other substrates. The precursors were synthesized and mixed in appropriate molar ratios to form the high Tc compound YBa2Cu3O(7-x), using a high boiling point common solvent base. The precursor solution was deposited by a spin casting technique on the substrates. Film thicknesses of 0.1-1.0 micron were achieved after heat treatment at 550-850 C at not longer than 4 hours. Films were analyzed as to orientation, appropriate phase, interfacial reaction, and superconducting properties.

  11. Understanding the in vivo uptake kinetics of a phosphatidylethanolamine-binding agent (99m)Tc-Duramycin.

    PubMed

    Audi, Said; Li, Zhixin; Capacete, Joseph; Liu, Yu; Fang, Wei; Shu, Laura G; Zhao, Ming

    2012-08-01

    (99m)Tc-Duramycin is a peptide-based molecular probe that binds specifically to phosphatidylethanolamine (PE). The goal was to characterize the kinetics of molecular interactions between (99m)Tc-Duramycin and the target tissue. High level of accessible PE is induced in cardiac tissues by myocardial ischemia (30 min) and reperfusion (120 min) in Sprague-Dawley rats. Target binding and biodistribution of (99m)Tc-duramycin were captured using SPECT/CT. To quantify the binding kinetics, the presence of radioactivity in ischemic versus normal cardiac tissues was measured by gamma counting at 3, 10, 20, 60 and 180 min after injection. A partially inactivated form of (99m)Tc-Duramycin was analyzed in the same fashion. A compartment model was developed to quantify the uptake kinetics of (99m)Tc-Duramycin in normal and ischemic myocardial tissue. (99m)Tc-duramycin binds avidly to the damaged tissue with a high target-to-background radio. Compartment modeling shows that accessibility of binding sites in myocardial tissue to (99m)Tc-Duramycin is not a limiting factor and the rate constant of target binding in the target tissue is at 2.2 ml/nmol/min/g. The number of available binding sites for (99m)Tc-Duramycin in ischemic myocardium was estimated at 0.14 nmol/g. Covalent modification of D15 resulted in a 9-fold reduction in binding affinity. (99m)Tc-Duramycin accumulates avidly in target tissues in a PE-dependent fashion. Model results reflect an efficient uptake mechanism, consistent with the low molecular weight of the radiopharmaceutical and the relatively high density of available binding sites. These data help better define the imaging utilities of (99m)Tc-Duramycin as a novel PE-binding agent. Copyright © 2012 Elsevier Inc. All rights reserved.

  12. Understanding the in vivo uptake kinetics of a phosphatidylethanolamine-binding agent 99mTc-Duramycin

    PubMed Central

    Audi, Said; Li, Zhixin; Capacete, Joseph; Liu, Yu; Fang, Wei; Shu, Laura G.; Zhao, Ming

    2013-01-01

    Introduction 99mTc-Duramycin is a peptide-based molecular probe that binds specifically to phosphatidylethanolamine (PE). The goal was to characterize the kinetics of molecular interactions between 99mTc-Duramycin and the target tissue. Methods High level of accessible PE is induced in cardiac tissues by myocardial ischemia (30 min) and reperfusion (120 min) in Sprague Dawley rats. Target binding and biodistribution of 99mTc-duramycin was captured using SPECT/CT. To quantify the binding kinetics, the presence of radioactivity in ischemic versus normal cardiac tissues was measured by gamma counting at 3, 10, 20, 60 and 180 min after injection. A partially inactivated form of 99mTc-Duramycin was analyzed in the same fashion. A compartment model was developed to quantify the uptake kinetics of 99mTc-Duramycin in normal and ischemic myocardial tissue. Results 99mTc-duramycin binds avidly to the damaged tissue with a high target-to-background radio. Compartment modeling shows that accessibility of binding sites in myocardial tissue to 99mTc-Duramycin is not a limiting factor and the rate constant of target binding in the target tissue is at 2.2 ml/nmol/min/g. The number of available binding sites for 99mTc-Duramycin in ischemic myocardium was estimated at 0.14 nmol/g. Covalent modification of D15 resulted in a 9 fold reduction in binding affinity. Conclusion 99mTc-Duramycin accumulates avidly in target tissues in a PE-dependent fashion. Model results reflect an efficient uptake mechanism, consistent with the low molecular weight of the radiopharmaceutical and the relatively high density of available binding sites. These data help better define the imaging utilities of 99mTc-Duramycin as a novel PE-binding agent. PMID:22534031

  13. Two peptide receptor ligands (99m)Tc-EDDA/HYNIC-Tyr(3)-octreotide and (99m)Tc-EDDA/HYNIC-(D)Glu-octagastrin for scintigraphy of medullary thyroid carcinoma.

    PubMed

    Kosowicz, Jerzy; Mikołajczak, Renata; Czepczyński, Rafał; Ziemnicka, Katarzyna; Gryczyńska, Maria; Sowiński, Jerzy

    2007-10-01

    Somatostatin and gastrin receptors are overexpressed in medullary thyroid carcinoma (MTC) cells; hence, both of them are potential targets for peptide receptor scintigraphy and radiotherapy. Therefore, the aim of our study was to assess the clinical value of two technetium-99m-labeled peptides, a new gastrin analog, the EDDA/HYNIC-(D)Glu-octagastrin and a somatostatin analog, EDDA/HYNIC-Tyr(3)-octreotide (EDDA/HYNIC-TOC) for scintigraphy in patients with MTC to detect recurrences and metastases and select patients for peptide receptor radiotherapy. Thirty (30) patients, 20 females and 10 males, 22-83 years of age (mean, 52.7) with the diagnosis of MTC in different stages of the disease (preoperative, postsurgery, remission, recurrence, or metastatic disease) were included in this study. Before surgery, in all patients serum calcitonin concentrations were elevated. The diagnosis of MTC was confirmed in all cases by histopathology of the removed tumor and immunohistochemical staining giving positive reactions for calcitonin and chromogranin A. Imaging studies using (99m)Tc-EDDA/HYNIC-TOC and a new minigastrin analog, (99m)Tc-EDDA/HYNIC-(D)Glu-octagastrin, were performed in each patient and the results compared with each other and with other imaging methods. Scans of the whole body, head, neck, and chest were performed 2 and 4 hours after injections of the tracer, 500-600 MBq in each case, using a double-head Varicam (Elscint, Israel) gamma camera. (99m)Tc-EDDA/HYNIC-TOC detected somatostatin receptor-positive lesions in 20 patients with MTC, whereas (99m)Tc-EDDA/HYNIC-(D)Glu-octagastrin displayed gastrin receptors in 11 patients. In 9 cases, the scans were positive in both methods, although in 2 cases different pathologic foci were visualized. In 12 cases, only (99m)Tc-EDDA/HYNIC-TOC scintigraphy was positive, whereas in 3 other cases only (99m)Tc-EDDA/HYNIC-(D)Glu-octagastrin revealed pathologic lesions. Scintigraphy using (99m)Tc-HYNIC-TOC permits the visualization

  14. High Tc superconductors as thermal radiation shields

    NASA Astrophysics Data System (ADS)

    Zeller, A. F.

    1990-06-01

    The feasibility of using high-Tc superconductor films as IR-radiation shields for liquid-helium-temperature dewars is investigated. Calculations show that a Ba-Ca-Sr-Cu-O superconductor with Tc of 110 K, combined with a liquid-nitrogen temperature shield with an emissivity of 0.03 should produce an upper limit to the radiative heat transfer of 15 mW/sq m. The reduction of reflectivity depends on the field level and the extent of field penetration into the superconductor film, whose surface also would provide magnetic shielding for low magnetic fields. Such shields, providing both magnetic and thermal radiation shielding would be useful for spaceborne applications where exposure to the degrading effects of moist air would not be a problem.

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

    NASA Astrophysics Data System (ADS)

    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.

  16. Reductive Sequestration Of Pertechnetate (99TcO4–) By Nano Zerovalent Iron (nZVI) Transformed By Abiotic Sulfide

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Fan, Dimin; Anitori, Roberto; Tebo, Bradley M.

    2013-04-24

    Under anoxic conditions, soluble 99TcO4– can be reduced to less soluble TcO2•nH2O, but the oxide is highly susceptible to reoxidation. Here we investigate an alternative strategy for remediation of Tc-contaminated groundwater whereby sequestration as Tc sulfide is favored by sulfidic conditions stimulated by nano zero-valent iron (nZVI). nZVI was pre-exposed to increasing concentrations of sulfide in simulated Hanford groundwater for 24 hrs to mimic the stages of aquifer sulfate reduction and onset of biotic sulfidogenesis. Solid-phase characterizations of the sulfidated nZVI confirmed the formation of nanocrystalline FeS phases, but higher S/Fe ratios (>0.112) did not result in the formation ofmore » significantly more FeS. The kinetics of Tc sequestration by these materials showed faster Tc removal rates with increasing S/Fe between S/Fe = 0–0.056, but decreasing Tc removal rates with S/Fe > 0.224. The more favorable Tc removal kinetics at low S/Fe could be due to a higher affinity of TcO4– for FeS (over iron oxides), and electron microscopy confirmed that the majority of the Tc was associated with FeS phases. The inhibition of Tc removal at high S/Fe appears to have been caused by excess HS–. X-ray absorption spectroscopy revealed that as S/Fe increased, Tc speciation shifted from TcO2•nH2O to TcS2. The most substantial change of Tc speciation occurred at low S/Fe, coinciding with the rapid increase of Tc removal rate. This agreement further confirms the importance of FeS in Tc sequestration.« less

  17. High Tc superconducting materials and devices

    NASA Technical Reports Server (NTRS)

    Haertling, Gene H.

    1990-01-01

    The high Tc Y1Ba2Cu3O(7-x) ceramic materials, initially developed in 1987, are now being extensively investigated for a variety of engineering applications. The superconductor applications which are presently identified as of most interest to NASA-LaRC are low-noise, low thermal conductivity grounding links; large-area linear Meissner-effect bearings; and sensitive, low-noise sensors and leads. Devices designed for these applications require the development of a number of processing and fabrication technologies. Included among the technologies most specific to the present needs are tapecasting, melt texturing, magnetic field grain alignment, superconductor/polymer composite fabrication, thin film MOD (metal-organic decomposition) processing, screen printing of thick films, and photolithography of thin films. The overall objective of the program was to establish a high Tc superconductivity laboratory capability at NASA-LaRC and demonstrate this capability by fabricating superconducting 123 material via bulk and thin film processes. Specific objectives include: order equipment and set up laboratory; prepare 1 kg batches of 123 material via oxide raw material; construct tapecaster and tapecaster 123 material; fabricate 123 grounding link; fabricate 123 composite for Meissner linear bearing; develop 123 thin film processes (nitrates, acetates); establish Tc and Jc measurement capability; and set up a commercial use of space program in superconductivity at LaRC. In general, most of the objectives of the program were met. Finally, efforts to implement a commercial use of space program in superconductivity at LaRC were completed and at least two industrial companies have indicated their interest in participating.

  18. The Current Experimental Status of the High Tc Problem

    NASA Astrophysics Data System (ADS)

    Greene, Richard

    Over 50,000 experimental papers have been published since 1987 on the copper oxide (cuprate) high Tc superconductors. In this talk, I will attempt to summarize the experimental properties that we presently understand and those that we don't yet understand. I will not speculate on the ``unknown unknowns'', although some examples of these have appeared during the past 30 years of research. I may also present a few slides about the status of iron-based superconductors, the other major class of unconventional high Tc materials.

  19. ECT imaging with Tc(V)-99m dimercaptosuccinic acid useful to detect lung metastases of osteosarcoma

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Ohta, H.; Ishii, M.; Yoshizumi, M.

    1985-01-01

    ECT imaging, using Tc(V)-99m dimercaptosuccinic acid (Tc(V)-DMS) was performed in two patients with lung metastasis of osteosarcoma, and the results were compared with those of CT scan. Clear accumulation of Tc(V)-DMS was recognized in all cases in the same area that CT scans demonstrated. Tc(V)-DMS was labeled under optimal pH 8, had very low SnCl/sub 2/ concentrations, an equilibrium between a stable form and a dissociated form of anion TcO/sub 4/(3-) structurally similar to PO/sub 4/(3-), and was postulated for tumor uptake. Considering this proposed mechanism for Tc(V)-DMS uptake by tumor cells, ECT imaging using this tracer could be ofmore » use in the early detection of lung metastasis of osteosarcoma.« less

  20. Modified TC for MICA offenders: crime outcomes.

    PubMed

    Sacks, Stanley; Sacks, JoAnn Y; McKendrick, Karen; Banks, Steven; Stommel, Joe

    2004-01-01

    The study randomly assigned male inmates with co-occurring serious mental illness and chemical abuse (MICA) disorders to either modified therapeutic community (MTC) or mental health (MH) treatment programs. On their release from prison, MICA inmates who completed the prison MTC program could enter the MTC aftercare program. The results, obtained from an intent-to-treat analysis of all study entries, showed that inmates randomized into the MTC group had significantly lower rates of reincarceration compared with those in the MH group. The results also show that differences between the MTC + aftercare and comparison group across a variety of crime outcomes (i.e. any criminal activity, and alcohol or drug related criminal activity) are consistent and significant, and persist after an examination of various threats to validity (e.g. initial motivation, duration of treatment, exposure to risk). This study provides some support for the effectiveness of the prison TC only condition. The findings are encouraging and consonant with other studies of integrated prison and aftercare TC programs for substance abusing non-MICA offenders, although qualified by the possibility that selection bias (i.e. differences in motivation on entry into aftercare) may be operating. Nevertheless, given the available evidence and the need for effective programming for MICA offenders, program and policy makers should strongly consider developing integrated prison and aftercare modified TC programs for MICA offenders. Copyright 2004 John Wiley & Sons, Ltd.

  1. Preoperative diagnosis of orbital cavernous hemangioma: a 99mTc-RBC SPECT study.

    PubMed

    Burroni, Luca; Borsari, Giulia; Pichierri, Patrizia; Polito, Ennio; Toscano, Olga; Grassetto, Gaia; Al-Nahhas, Adil; Rubello, Domenico; Vattimo, Angelo Giuseppe

    2012-11-01

    This study aimed to describe 99mTc-labeled RBC scintigraphy as a diagnostic method for orbital cavernous hemangiomas and to evaluate this diagnostic tool according to surgical outcomes. Fifty-five patients with clinical and radiological (US, CT, and/or MRI) suspicion of unilateral cavernous hemangioma of the orbit underwent 99mTc-RBC SPECT study.Qualitative and semiquantitative evaluations were performed, and results were statistically analyzed. SPECT images showed focal uptake in the orbital mass in 36 of 55 patients. Nineteen patients had a negative scintigraphic pattern, with concordance of early and late absence of uptake of 99mTc-RBC.Our procedure showed 100% sensitivity and 88.9% specificity for the diagnosis of orbital cavernous hemangioma, with a positive predictive value of 90.9% and a negative predictive value of 100%. 99mTc-RBC imaging is safe, easy to perform, and highly accurate in providing adequate clinical and surgical management. As a noninvasive and highly specific method for diagnosing orbital hemangioma, 99mTc-RBC scintigraphy can avoid more invasive imaging or biopsy.

  2. 99mTc-EDDA/HYNIC-octreotate in detection of atypical bronchial carcinoid.

    PubMed

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

    2007-01-01

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

  3. Multi-Detector Row Computed Tomography Findings of Pelvic Congestion Syndrome Caused by Dilated Ovarian Veins

    PubMed Central

    Eren, Suat

    2010-01-01

    Objective: To evaluate the efficacy of multi-detector row CT (MDCT) on pelvic congestion syndrome (PCS), which is often overlooked or poorly visualized with routine imaging examination. Materials and Methods: We evaluated the MDCT features of 40 patients with PCS (mean age, 45 years; range, 29–60 years) using axial, coronal, sagittal, 3D volume-rendered, and Maximum Intensity Projection MIP images. Results: MDCT revealed pelvic varices and ovarian vein dilatations in all patients. Bilateral ovarian vein dilatation was present in 25 patients, and 15 patients had unilateral dilatation. While 12 cases of secondary pelvic varices occurred simultaneously with a retroaortic left renal vein, 10 cases were due solely to a mass obstruction or stenosis of venous structures. Conclusion: MDCT is an effective tool in the evaluation of PCS, and it has more advantages than other imaging modalities. PMID:25610142

  4. The absorption of (99m)Tc-alendronate given by rectal route in rabbits.

    PubMed

    Asikoğlu, Makbule; Ozguney, Isik; Ozcan, Ipek; Orumlu, Oya; Guneri, Tamer; Koseoğlu, Kamil; Ozkilic, Hayal

    2008-01-01

    Alendronate sodium (ALD) is a bisphosphonate medication used in the treatment and prevention of osteoporosis. Absorption of ALD as oral formulation is very poor (0.5%-1%). Its bioavailability can decrease with food effect. It has some gastrointestinal adverse effects such as gastritis, gastric ulcer, and esophagitis. The aim of this study was to develop a rectal formulation of ALD as an alternative to oral route and to investigate the absorption of it by using gamma scintigraphy. For this reason, ALD was labeled with Technetium-99m ((99m)Tc) by direct method. The radiochemical characterization of the (99m)Tc-ALD was carried out by paper chromatography, thin layer chromatography, and electrophoresis methods. The labeling efficiency of (99m)Tc-ALD was found 99% without significant changes until 6 h postlabeling at room temperature. The rectal suppositories containing (99m)Tc-ALD were prepared by fusion method using polyethylene glycol (PEG) 1500. The (99m)Tc-labeled ALD suppositories were administrated to rabbits by rectal route. Serial scintigrams over all bodies of the rabbits were obtained at different time intervals using a gamma camera. We found that the rectal absorption of (99m)Tc-ALD from suppository formulation was possible. According to our results, this formulation of ALD can be suggested for the therapy of osteoporosis as an alternative route.

  5. Papiloma invertido sinunasal con invasión intracraneal: Reporte de caso y revisión bibliográfica

    PubMed Central

    Di Pietrantonio, Andrés; Asmus, Humberto; Ingratta, Christian; Brennan, Walter; Schulz, Javier; Carballo, Leandro

    2018-01-01

    Resumen IntroducciÓn: El papiloma invertido es una neoplasia benigna de los senos paranasales localmente agresiva con alto potencial de recurrencia y de malignización. La extensión intracraneal es infrecuente y más aún, la penetración dural, asociándose a menudo a la recurrencia de la enfermedad o a su degeneración en carcinoma de células escamosas. Caso clínico: Presentamos el caso de una paciente de 32 años que consultó por lesión exofítica en fosa nasal derecha y exoftalmos, asociada a cefalea, anosmia y disgeusia. Se estudió con TC cerebro, macizo facial y RM de encéfalo que evidencian lesión en fosa nasal derecha con ocupación de senos aéreos, osteólisis de pared medial orbitaria y base de cráneo anterior e invasión intracraneal frontal derecha, con efecto de masa y compresión del parénquima encefálico adyacente. Intervención: Se realizó una nasofibroscopía en primer tiempo con diagnóstico anatomopatológico de papiloma invertido y posteriormente resección de la lesión mediante doble abordaje más reconstrucción de la fosa craneal anterior. Se obtuvo diagnóstico definitivo de papiloma invertido de tipo Schneideriano con áreas de transformación atípica in situ. La paciente evolucionó de forma favorable y sin complicaciones, con permeabilidad de vía aérea superior, sin signos de recidiva lesional luego de 4 años de seguimiento. Conclusión: La invasión intracraneal de esta patología es sumamente infrecuente. Cuando existe, es indicador de agresividad y potencial recidiva, por lo que la exéresis completa de la misma define el pronóstico de la enfermedad. PMID:29430328

  6. Adolescent Services & the TC. Chapter 6.

    ERIC Educational Resources Information Center

    Acampora, Alfonso P., Ed.; Nebelkopf, Ethan, Ed.

    This document contains seven papers from the ninth World Conference of Therapeutic Communities (TCs) that deal with adolescent clients and TCs. Papers include: (1) Preliminary Consideration on "Adolescence and the TC" (David Deitch); (2) "Daytop's Full Service Adolescent Treatment Program" (Charles Devlin and Lois Morris); (3)…

  7. Imaging study of using radiopharmaceuticals labeled with cyclotron-produced 99mTc.

    PubMed

    Hou, X; Tanguay, J; Vuckovic, M; Buckley, K; Schaffer, P; Bénard, F; Ruth, T J; Celler, A

    2016-12-07

    Cyclotron-produced 99m Tc (CPTc) has been recognized as an attractive and practical substitution of reactor/generator based 99m Tc. However, the small amount of 92-98 Mo in the irradiation of enriched 100 Mo could lead to the production of other radioactive technetium isotopes (Tc-impurities) which cannot be chemically separated. Thus, these impurities could contribute to patient dose and affect image quality. The potential radiation dose caused by these Tc-impurities produced using different targets, irradiation conditions, and corresponding to different injection times have been investigated, leading us to create dose-based limits of these parameters for producing clinically acceptable CPTc. However, image quality has been not considered. The aim of the present work is to provide a comprehensive and quantitative analysis of image quality for CPTc. The impact of Tc-impurities in CPTc on image resolution, background noise, and contrast is investigated by performing both Monte-Carlo simulations and phantom experiments. Various targets, irradiation, and acquisition conditions are employed for investigating the image-based limits of CPTc production parameters. Additionally, the relationship between patient dose and image quality of CPTc samples is studied. Only those samples which meet both dose- and image-based limits should be accepted in future clinical studies.

  8. Influence of Storage Temperature on Radiochemical Purity of 99mTc-Radiopharmaceuticals.

    PubMed

    Uccelli, Licia; Boschi, Alessandra; Martini, Petra; Cittanti, Corrado; Bertelli, Stefania; Bortolotti, Doretta; Govoni, Elena; Lodi, Luca; Romani, Simona; Zaccaria, Samanta; Zappaterra, Elisa; Farina, Donatella; Rizzo, Carlotta; Giganti, Melchiore; Bartolomei, Mirco

    2018-03-15

    The influence of effective room temperature on the radiochemical purity of 99m Tc-radiopharmaceuticals was reported. This study was born from the observation that in the isolators used for the preparation of the 99m Tc-radiopharmaceuticals the temperatures can be higher than those reported in the commercial illustrative leaflets of the kits. This is due, in particular, to the small size of the work area, the presence of instruments for heating, the continuous activation of air filtration, in addition to the fact that the environment of the isolator used for the 99m Tc-radiopharmaceuticals preparation and storage is completely isolated and not conditioned. A total of 244 99m Tc-radiopharmaceutical preparations (seven different types) have been tested and the radiochemical purity was checked at the end of preparation and until the expiry time. Moreover, we found that the mean temperature into the isolator was significantly higher than 25 °C, the temperature, in general, required for the preparation and storage of 99m Tc-radiopharmaceuticals. Results confirmed the radiochemical stability of radiopharmaceutical products. However, as required in the field of quality assurance, the impact that different conditions than those required by the manufacturer on the radiopharmaceuticals quality have to be verified before human administration.

  9. Imaging study of using radiopharmaceuticals labeled with cyclotron-produced 99mTc

    NASA Astrophysics Data System (ADS)

    Hou, X.; Tanguay, J.; Vuckovic, M.; Buckley, K.; Schaffer, P.; Bénard, F.; Ruth, T. J.; Celler, A.

    2016-12-01

    Cyclotron-produced 99mTc (CPTc) has been recognized as an attractive and practical substitution of reactor/generator based 99mTc. However, the small amount of 92-98Mo in the irradiation of enriched 100Mo could lead to the production of other radioactive technetium isotopes (Tc-impurities) which cannot be chemically separated. Thus, these impurities could contribute to patient dose and affect image quality. The potential radiation dose caused by these Tc-impurities produced using different targets, irradiation conditions, and corresponding to different injection times have been investigated, leading us to create dose-based limits of these parameters for producing clinically acceptable CPTc. However, image quality has been not considered. The aim of the present work is to provide a comprehensive and quantitative analysis of image quality for CPTc. The impact of Tc-impurities in CPTc on image resolution, background noise, and contrast is investigated by performing both Monte-Carlo simulations and phantom experiments. Various targets, irradiation, and acquisition conditions are employed for investigating the image-based limits of CPTc production parameters. Additionally, the relationship between patient dose and image quality of CPTc samples is studied. Only those samples which meet both dose- and image-based limits should be accepted in future clinical studies.

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

    PubMed

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

    2014-10-01

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

  11. A fast and simple dose-calibrator-based quality control test for the radionuclidic purity of cyclotron-produced (99m)Tc.

    PubMed

    Tanguay, J; Hou, X; Esquinas, P; Vuckovic, M; Buckley, K; Schaffer, P; Bénard, F; Ruth, T J; Celler, A

    2015-11-07

    Cyclotron production of 99mTc through the (100)Mo(p,2n)99mTc reaction channel is actively being investigated as an alternative to reactor-based (99)Mo generation by nuclear fission of (235)U. Like most radioisotope production methods, cyclotron production of 99mTc will result in creation of unwanted impurities, including Tc and non-Tc isotopes. It is important to measure the amounts of these impurities for release of cyclotron-produced 99mTc (CPTc) for clinical use. Detection of radioactive impurities will rely on measurements of their gamma (γ) emissions. Gamma spectroscopy is not suitable for this purpose because the overwhelming presence of 99mTc and the count-rate limitations of γ spectroscopy systems preclude fast and accurate measurement of small amounts of impurities. In this article we describe a simple and fast method for measuring γ emission rates from radioactive impurities in CPTc. The proposed method is similar to that used to identify (99)Mo breakthrough in generator-produced 99mTc: one dose calibrator (DC) reading of a CPTc source placed in a lead shield is followed by a second reading of the same source in air. Our experimental and theoretical analysis show that the ratio of DC readings in lead to those in air are linearly related to γ emission rates from impurities per MBq of 99mTc over a large range of clinically-relevant production conditions. We show that estimates of the γ emission rates from Tc impurities per MBq of 99mTc can be used to estimate increases in radiation dose (relative to pure 99mTc) to patients injected with CPTc-based radiopharmaceuticals. This enables establishing dosimetry-based clinical-release criteria that can be tested using commercially-available dose calibrators. We show that our approach is highly sensitive to the presence of 93gTc, 93mTc, 94gTc, 94mTc, 95mTc, 95gTc, and 96gTc, in addition to a number of non-Tc impurities.

  12. Biokinetics and dosimetric studies about 99mTc(V)-DMSA distribution.

    PubMed

    Correia, M B L; Magnata, S S L P; Silva, I M S; Catanho, M T J A; Lima, F F

    2010-05-10

    Research for radiodiagnostic agents should considerate biological critical parameters which will give own contribution on the absorbed dose. The dimercaptosuccinic acid (DMSA) labeled with (99m)Tc(V) is a radiopharmaceutical which has well established role in medullar thyroid carcinoma and has been proposed in evaluation of bone metastasis. This work studied the biokinetics and dosimetry of (99m)Tc(V)-DMSA by animal model. The (99m)Tc(V)-DMSA was prepared from a (III)DMSA kit alkalized. Mice (n=5) received (99m)Tc(V)DMSA i.v., they were sacrificed (30 min, 1h, 5h and 12h), the organs excised and the activities measured by a gamma counter. The results were evaluated based on %activity/g and the absorbed dose was estimated (MIRDOSE 3.0 program) by extrapolation of data from animal to human scale. The results showed the majority of organs reached the top uptake at 30 min, the greatest kidney uptake was (4.81 +/- 1.38)% activity/g, while the bone presented its highest uptake at 1h (5.49+/- 0.47)% activity/g, after 1h all the organs had activity exponential decrease. The biokinetic profile of (99m)Tc(V)-DMSA was well established, allowing quantifying of residence time, and the radiation dose estimates were made for this agent. About the absorbed dose, the preliminary results showed higher value to bone, being the soft tissue dose relatively low.

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

    PubMed

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

    2016-04-01

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

  14. Immune Protection against Trypanosoma cruzi Induced by TcVac4 in a Canine Model

    PubMed Central

    Aparicio-Burgos, José E.; Zepeda-Escobar, José A.; de Oca-Jimenez, Roberto Montes; Estrada-Franco, José G.; Barbabosa-Pliego, Alberto; Ochoa-García, Laucel; Alejandre-Aguilar, Ricardo; Rivas, Nancy; Peñuelas-Rivas, Giovanna; Val-Arreola, Margarita; Gupta, Shivali; Salazar-García, Felix; Garg, Nisha J.; Vázquez-Chagoyán, Juan C.

    2015-01-01

    Chagas disease, caused by Trypanosoma cruzi, is endemic in southern parts of the American continent. Herein, we have tested the protective efficacy of a DNA-prime/T. rangeli-boost (TcVac4) vaccine in a dog (Canis familiaris) model. Dogs were immunized with two-doses of DNA vaccine (pcDNA3.1 encoding TcG1, TcG2, and TcG4 antigens plus IL-12- and GM-CSF-encoding plasmids) followed by two doses of glutaraldehyde-inactivated T. rangeli epimastigotes (TrIE); and challenged with highly pathogenic T. cruzi (SylvioX10/4) isolate. Dogs given TrIE or empty pcDNA3.1 were used as controls. We monitored post-vaccination and post-challenge infection antibody response by an ELISA, parasitemia by blood analysis and xenodiagnosis, and heart function by electrocardiography. Post-mortem anatomic and pathologic evaluation of the heart was conducted. TcVac4 induced a strong IgG response (IgG2>IgG1) that was significantly expanded post-infection, and moved to a nearly balanced IgG2/IgG1 response in chronic phase. In comparison, dogs given TrIE or empty plasmid DNA only developed high IgG titers with IgG2 predominance in response to T. cruzi infection. Blood parasitemia, tissue parasite foci, parasite transmission to triatomines, electrocardiographic abnormalities were significantly lower in TcVac4-vaccinated dogs than was observed in dogs given TrIE or empty plasmid DNA only. Macroscopic and microscopic alterations, the hallmarks of chronic Chagas disease, were significantly decreased in the myocardium of TcVac4-vaccinated dogs. We conclude that TcVac4 induced immunity was beneficial in providing resistance to T. cruzi infection, evidenced by control of chronic pathology of the heart and preservation of cardiac function in dogs. Additionally, TcVac4 vaccination decreased the transmission of parasites from vaccinated/infected animals to triatomines. PMID:25853654

  15. Immune protection against Trypanosoma cruzi induced by TcVac4 in a canine model.

    PubMed

    Aparicio-Burgos, José E; Zepeda-Escobar, José A; de Oca-Jimenez, Roberto Montes; Estrada-Franco, José G; Barbabosa-Pliego, Alberto; Ochoa-García, Laucel; Alejandre-Aguilar, Ricardo; Rivas, Nancy; Peñuelas-Rivas, Giovanna; Val-Arreola, Margarita; Gupta, Shivali; Salazar-García, Felix; Garg, Nisha J; Vázquez-Chagoyán, Juan C

    2015-04-01

    Chagas disease, caused by Trypanosoma cruzi, is endemic in southern parts of the American continent. Herein, we have tested the protective efficacy of a DNA-prime/T. rangeli-boost (TcVac4) vaccine in a dog (Canis familiaris) model. Dogs were immunized with two-doses of DNA vaccine (pcDNA3.1 encoding TcG1, TcG2, and TcG4 antigens plus IL-12- and GM-CSF-encoding plasmids) followed by two doses of glutaraldehyde-inactivated T. rangeli epimastigotes (TrIE); and challenged with highly pathogenic T. cruzi (SylvioX10/4) isolate. Dogs given TrIE or empty pcDNA3.1 were used as controls. We monitored post-vaccination and post-challenge infection antibody response by an ELISA, parasitemia by blood analysis and xenodiagnosis, and heart function by electrocardiography. Post-mortem anatomic and pathologic evaluation of the heart was conducted. TcVac4 induced a strong IgG response (IgG2>IgG1) that was significantly expanded post-infection, and moved to a nearly balanced IgG2/IgG1 response in chronic phase. In comparison, dogs given TrIE or empty plasmid DNA only developed high IgG titers with IgG2 predominance in response to T. cruzi infection. Blood parasitemia, tissue parasite foci, parasite transmission to triatomines, electrocardiographic abnormalities were significantly lower in TcVac4-vaccinated dogs than was observed in dogs given TrIE or empty plasmid DNA only. Macroscopic and microscopic alterations, the hallmarks of chronic Chagas disease, were significantly decreased in the myocardium of TcVac4-vaccinated dogs. We conclude that TcVac4 induced immunity was beneficial in providing resistance to T. cruzi infection, evidenced by control of chronic pathology of the heart and preservation of cardiac function in dogs. Additionally, TcVac4 vaccination decreased the transmission of parasites from vaccinated/infected animals to triatomines.

  16. Synthesis and biological evaluation of new diisocyanide- and triisocyanide-99mTc complexes.

    PubMed

    Chemin, N; du Moulinet d'Hardemare, A; Bouquillon, S; Fagret, D; Vidal, M

    1996-01-01

    This paper describes the synthesis of four new polyisocyanides (three diisocyanides and one triisocyanide). The complexation of 99mTc with these ligands is also studied through chromatography and revealed the formation of hexacoordinated 99mTc+1 complexes. Finally, biodistributions of these complexes in mice are given and compared. Heart captations are lower than the ones with [99mTc(MIBI)6]+ but remain constant and a satisfactory lungs clearance, probably due to the metabolization of the ligands, is observed.

  17. HiTC: exploration of high-throughput ‘C’ experiments

    PubMed Central

    Servant, Nicolas; Lajoie, Bryan R.; Nora, Elphège P.; Giorgetti, Luca; Chen, Chong-Jian; Heard, Edith; Dekker, Job; Barillot, Emmanuel

    2012-01-01

    Summary: The R/Bioconductor package HiTC facilitates the exploration of high-throughput 3C-based data. It allows users to import and export ‘C’ data, to transform, normalize, annotate and visualize interaction maps. The package operates within the Bioconductor framework and thus offers new opportunities for future development in this field. Availability and implementation: The R package HiTC is available from the Bioconductor website. A detailed vignette provides additional documentation and help for using the package. Contact: nicolas.servant@curie.fr Supplementary information: Supplementary data are available at Bioinformatics online. PMID:22923296

  18. High Tc superconducting bolometric and nonbolometric infrared (IR) detectors

    NASA Technical Reports Server (NTRS)

    Lakeou, Samuel

    1994-01-01

    The original workplan for the first year of the project includes the following: establishment of a pilot superconductivity application laboratory at UDC to support the research component of the project; research on the source of electrical noise in High Tc superconducting films in order to optimize the film microstructure and lower the NEP; and lay the foundation of an academic support for exposing UDC students to the theory and application of High Tc superconductivity. Attached to this status report are abstracts and the course description for Introduction to Applications of Superconductivity.

  19. Multidetector computed tomography findings of central bronchopleural fistulas as sequelae of tuberculosis, chemo radiation and trauma: A report of three cases

    PubMed Central

    Yuksekkaya, Ruken; Ozturk, Banu; Celikyay, Fatih; Sade, Recep; Kupeli, Mustafa; Yeginsu, Ali

    2013-01-01

    A bronchopleural fistula (BPF) is defined as a direct pathway between the bronchial tree or lung parenchyma and the pleural space. Herein, we describe the clinical findings and imaging results of BPFs in three cases. The patients' medical histories revealed that the first had recurrent pulmonary tuberculosis, the second had small-cell lung cancer (SCLC) and had previously undergone chemoradiotherapy, and the third had trauma. Multidetector computed tomography (MDCT) showed clear communication between the airways and pleural spaces which was sufficient for a proper diagnosis without performing a bronchoscopy. PMID:26029624

  20. An autotrophic H 2 -oxidizing, nitrate-respiring, Tc(VII)-reducing A cidovorax sp. isolated from a subsurface oxic-anoxic transition zone: H 2 -oxidizing, Tc-reducing Acidovorax spp.

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Lee, Ji-Hoon; Fredrickson, James K.; Plymale, Andrew E.

    2015-04-08

    Increasing concentrations of H 2 with depth were observed across a geologic unconformity and associated redox transition zone in the subsurface at the Hanford Site in south-central Washington, USA. An opposing gradient characterized by decreasing O 2 and nitrate concentrations was consistent with microbial-catalyzed biogeochemical processes. Sterile sand was incubated in situ within a multi-level sampler placed across the redox transition zone to evaluate the potential for Tc(VII) reduction and for enrichment of H 2-oxidizing denitrifiers capable of reducing Tc(VII). H 2-driven TcO 4- reduction was detected in sand incubated at all depths but was strongest in material from amore » depth of 17.1 m. Acidovorax spp. were isolated from H 2-nitrate enrichments from colonized sand from 15.1 m, with one representative, strain JHL-9, subsequently characterized. JHL-9 grew on acetate with either O 2 or nitrate as electron acceptor (data not shown) and on medium with bicarbonate, H 2 and nitrate. JHL-9 also reduced pertechnetate (TcO 4-) under denitrifying conditions with H 2 as the electron donor. H 2-oxidizing Acidovorax spp. in the subsurface at Hanford and other locations may contribute to the maintenance of subsurface redox gradients and offer the potential for Tc(VII) reduction.« less

  1. Passport, a native Tc1 transposon from flatfish, is functionally active in vertebrate cells

    PubMed Central

    Clark, Karl J.; Carlson, Daniel F.; Leaver, Michael J.; Foster, Linda K.; Fahrenkrug, Scott C.

    2009-01-01

    The Tc1/mariner family of DNA transposons is widespread across fungal, plant and animal kingdoms, and thought to contribute to the evolution of their host genomes. To date, an active Tc1 transposon has not been identified within the native genome of a vertebrate. We demonstrate that Passport, a native transposon isolated from a fish (Pleuronectes platessa), is active in a variety of vertebrate cells. In transposition assays, we found that the Passport transposon system improved stable cellular transgenesis by 40-fold, has an apparent preference for insertion into genes, and is subject to overproduction inhibition like other Tc1 elements. Passport represents the first vertebrate Tc1 element described as both natively intact and functionally active, and given its restricted phylogenetic distribution, may be contemporaneously active. The Passport transposon system thus complements the available genetic tools for the manipulation of vertebrate genomes, and may provide a unique system for studying the infiltration of vertebrate genomes by Tc1 elements. PMID:19136468

  2. Passport, a native Tc1 transposon from flatfish, is functionally active in vertebrate cells.

    PubMed

    Clark, Karl J; Carlson, Daniel F; Leaver, Michael J; Foster, Linda K; Fahrenkrug, Scott C

    2009-03-01

    The Tc1/mariner family of DNA transposons is widespread across fungal, plant and animal kingdoms, and thought to contribute to the evolution of their host genomes. To date, an active Tc1 transposon has not been identified within the native genome of a vertebrate. We demonstrate that Passport, a native transposon isolated from a fish (Pleuronectes platessa), is active in a variety of vertebrate cells. In transposition assays, we found that the Passport transposon system improved stable cellular transgenesis by 40-fold, has an apparent preference for insertion into genes, and is subject to overproduction inhibition like other Tc1 elements. Passport represents the first vertebrate Tc1 element described as both natively intact and functionally active, and given its restricted phylogenetic distribution, may be contemporaneously active. The Passport transposon system thus complements the available genetic tools for the manipulation of vertebrate genomes, and may provide a unique system for studying the infiltration of vertebrate genomes by Tc1 elements.

  3. Water-stable fac-{TcO₃}⁺ complexes - a new field of technetium chemistry.

    PubMed

    Braband, Henrik

    2011-01-01

    The development of technetium chemistry has been lagging behind that of its heavier congener rhenium, primarily because the inherent radioactivity of all Tc isotopes has limited the number of laboratories that can study the chemistry of this fascinating element. Although technetium is an artificial element, it is not rare. Significant amounts of the isotope (99)Tc are produced every day as a fission byproduct in nuclear power plants. Therefore, a fundamental understanding of the chemistry of (99)Tc is essential to avoid its release into the environment. In this article the chemistry of technetium at its highest oxidation state (+VII) is reviewed with a special focus on recent developments which make water-stable complexes of the general type [TcO(3)(tacn-R)](+) (tacn-R = 1,4,7-triazacyclononane or derivatives) accessible. Complexes containing the fac-{TcO(3)}(+) core display a unique reactivity. In analogy to [OsO(4)] and [RuO(4)], complexes containing the fac-{TcO(3)}(+) core undergo with alkenes metal-mediated, vicinal cis-dihydroxylation reactions (alkene-glycol interconversion) in water via a (3+2)-cycloaddition reaction. Therefore, water-stable fac-{(99m)TcO(3)}(+) complexes pave the way for a new labeling strategy for radiopharmaceutical applications, based on (3+2)-cycloaddition reactions. This new concept for the labeling of biomolecules with small [(99m)TcO(3)(tacn-R)](+)-type complexes by way of a (3+2)-cycloaddition with alkenes is discussed in detail. The herein reported developments in high-valent technetium chemistry create a new field of research with this artificial element. This demonstrates the potential of fundamental research to provide new impetus of innovation for the development of new methods for radiopharmaceutical applications.

  4. [Gastrointestinal bleeding from capillary hemangioma of the ileum detected by 99mTc-HSAD scintigraphy].

    PubMed

    Asano, Y; Ishii, K; Sagiuchi, T; Aoki, Y; Yanaihara, H; Hayakawa, K

    2001-05-01

    It has been well-known that technetium-99m-human serum albumin-diethylenetriaminepenta-acetic acid (99mTc-HSAD) scintigraphy is useful for diagnosis of the localization of the gastrointestinal arterial or venous bleeding. In this report, we describe a case of venous bleeding from capillary hemangioma of the ileum end detected by 99mTc-HSAD scintigraphy. This patient was a 9-year-old girl with severe anemia. Gastrointestinal bleeding was suspected from her clinical course and laboratory tests. Immediately after melena occurred, 99mTc-HSAD scintigraphy showed the extravasation of RI suggesting gastrointestinal bleeding in the ileum end. Abdominal angiography immediately after 99mTc-HSAD scintigraphy, however, could not show the extravasation of contrast agent. Because the condition of the patient became worse, laparotomy was performed on the basis of 99mTc-HSAD scintigraphy findings. At surgery, venous bleeding from capillary hemangioma in the ileum end was observed. It was suggested that 99mTc-HSAD scintigraphy was very useful for identifying the gastrointestinal venous bleeding.

  5. Radionuclide imaging in myocardial sarcoidosis. Demonstration of myocardial uptake of /sup 99m/Tc pyrophosphate and gallium

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Forman, M.B.; Sandler, M.P.; Sacks, G.A.

    1983-03-01

    A patient had severe congestive cardiomyopathy secondary to myocardial sarcoidosis. The clinical diagnosis was confirmed by radionuclide ventriculography, /sup 201/Tl, /sup 67/Ga, and /sup 99m/Tc pyrophosphate (TcPYP) scintigraphy. Myocardial TcPYP uptake has not been reported previously in sarcoidosis. In this patient, TcPYP was as useful as gallium scanning and thallium imaging in documenting the myocardial process.

  6. Potential Ways to Address Shortage Situations of 99Mo/99mTc.

    PubMed

    Filzen, Leah M; Ellingson, Lacey R; Paulsen, Andrew M; Hung, Joseph C

    2017-03-01

    99m Tc, the most common radioisotope used in nuclear medicine, is produced in a nuclear reactor from the decay of 99 Mo. There are only a few aging nuclear reactors around the world that produce 99 Mo, and one of the major contributors, the National Research Universal (Canada), ceased production on October 31, 2016. The National Research Universal produced approximately 40% of the world's 99 Mo supply, so with its shut down, shortages of 99 Mo/ 99m Tc are expected. Methods: Nuclear pharmacies and nuclear medicine departments throughout the United States were contacted and asked to provide their strategies for coping with a shortage of 99 Mo/ 99m Tc. Each of these strategies was evaluated on the basis of its effectiveness for conserving 99m Tc while still meeting the needs of the patients. Results: From the responses, the following 6 categories of strategies, in order of importance, were compiled: contractual agreements with commercial nuclear pharmacies, alternative imaging protocols, changes in imaging schedules, software use, generator management, and reduction of ordered doses or elimination of backup doses. Conclusion: The supply chain of 99 Mo/ 99m Tc is quite fragile; therefore, being aware of the most appropriate coping strategies is crucial. It is essential to build a strong collaboration between the nuclear pharmacy and nuclear medicine department during a shortage situation. With both nuclear medicine departments and nuclear pharmacies implementing viable strategies, such as the ones proposed, the amount of 99m Tc available during a shortage situation can be maximized. © 2017 by the Society of Nuclear Medicine and Molecular Imaging.

  7. Power Systems Development Facility Gasification Test Campaing TC18

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Southern Company Services

    2005-08-31

    In support of technology development to utilize coal for efficient, affordable, and environmentally clean power generation, the Power Systems Development Facility (PSDF) located in Wilsonville, Alabama, routinely demonstrates gasification technologies using various types of coals. The PSDF is an engineering scale demonstration of key features of advanced coal-fired power systems, including a KBR Transport Gasifier, a hot gas particulate control device (PCD), advanced syngas cleanup systems, and high pressure solids handling systems. This report details Test Campaign TC18 of the PSDF gasification process. Test campaign TC18 began on June 23, 2005, and ended on August 22, 2005, with the gasifiermore » train accumulating 1,342 hours of operation using Powder River Basin (PRB) subbituminous coal. Some of the testing conducted included commissioning of a new recycle syngas compressor for gasifier aeration, evaluation of PCD filter elements and failsafes, testing of gas cleanup technologies, and further evaluation of solids handling equipment. At the conclusion of TC18, the PSDF gasification process had been operated for more than 7,750 hours.« less

  8. A fast and simple dose-calibrator-based quality control test for the radionuclidic purity of cyclotron-produced 99mTc

    NASA Astrophysics Data System (ADS)

    Tanguay, J.; Hou, X.; Esquinas, P.; Vuckovic, M.; Buckley, K.; Schaffer, P.; Bénard, F.; Ruth, T. J.; Celler, A.

    2015-11-01

    Cyclotron production of {{}99\\text{m}} Tc through the 100Mo(p,2n){{}99\\text{m}} Tc reaction channel is actively being investigated as an alternative to reactor-based 99Mo generation by nuclear fission of 235U. Like most radioisotope production methods, cyclotron production of {{}99\\text{m}} Tc will result in creation of unwanted impurities, including Tc and non-Tc isotopes. It is important to measure the amounts of these impurities for release of cyclotron-produced {{}99\\text{m}} Tc (CPTc) for clinical use. Detection of radioactive impurities will rely on measurements of their gamma (γ) emissions. Gamma spectroscopy is not suitable for this purpose because the overwhelming presence of {{}99\\text{m}} Tc and the count-rate limitations of γ spectroscopy systems preclude fast and accurate measurement of small amounts of impurities. In this article we describe a simple and fast method for measuring γ emission rates from radioactive impurities in CPTc. The proposed method is similar to that used to identify 99Mo breakthrough in generator-produced {{}99\\text{m}} Tc: one dose calibrator (DC) reading of a CPTc source placed in a lead shield is followed by a second reading of the same source in air. Our experimental and theoretical analysis show that the ratio of DC readings in lead to those in air are linearly related to γ emission rates from impurities per MBq of {{}99\\text{m}} Tc over a large range of clinically-relevant production conditions. We show that estimates of the γ emission rates from Tc impurities per MBq of {{}99\\text{m}} Tc can be used to estimate increases in radiation dose (relative to pure {{}99\\text{m}} Tc) to patients injected with CPTc-based radiopharmaceuticals. This enables establishing dosimetry-based clinical-release criteria that can be tested using commercially-available dose calibrators. We show that our approach is highly sensitive to the presence of {{}93\\text{g}} Tc, {{}93\\text{m}} Tc, {{}94\\text{g}} Tc, {{}94\\text{m}} Tc

  9. Trypanosoma cruzi H+-ATPase 1 (TcHA1) and 2 (TcHA2) genes complement yeast mutants defective in H+ pumps and encode plasma membrane P-type H+-ATPases with different enzymatic properties.

    PubMed

    Luo, Shuhong; Scott, David A; Docampo, Roberto

    2002-11-15

    Previous studies in Trypanosoma cruzi have shown that intracellular pH homeostasis requires ATP and is affected by H(+)-ATPase inhibitors, indicating a major role for ATP-driven proton pumps in intracellular pH control. In the present study, we report the cloning and sequencing of a pair of genes linked in tandem (TcHA1 and TcHA2) in T. cruzi which encode proteins with homology to fungal and plant P-type proton-pumping ATPases. The genes are expressed at the mRNA level in different developmental stages of T. cruzi: TcHA1 is expressed maximally in epimastigotes, whereas TcHA2 is expressed predominantly in trypomastigotes. The proteins predicted from the nucleotide sequence of the genes have 875 and 917 amino acids and molecular masses of 96.3 and 101.2 kDa, respectively. Full-length TcHA1 and an N-terminal truncated version of TcHA2 complemented a Saccharomyces cerevisiae strain deficient in P-type H(+)-ATPase activity, the proteins localized to the yeast plasma membrane, and ATP-driven proton pumping could be detected in proteoliposomes reconstituted from plasma membrane purified from transfected yeast. The reconstituted proton transport activity was reduced by inhibitors of P-type H(+)-ATPases. C-terminal truncation did not affect complementation of mutant yeast, suggesting the lack of C-terminal autoinhibitory domains in these proteins. ATPase activity in plasma membrane from TcHA1- and (N-terminal truncated) TcHA2-transfected yeast was inhibited to different extents by vanadate, whereas the latter yeast strain was more resistant to extremes of pH, suggesting that the native proteins may serve different functions at different stages in the T. cruzi life cycle.

  10. Secrets of soil survival revealed by the genome sequence of Arthrobacter aurescens TC1.

    PubMed

    Mongodin, Emmanuel F; Shapir, Nir; Daugherty, Sean C; DeBoy, Robert T; Emerson, Joanne B; Shvartzbeyn, Alla; Radune, Diana; Vamathevan, Jessica; Riggs, Florenta; Grinberg, Viktoria; Khouri, Hoda; Wackett, Lawrence P; Nelson, Karen E; Sadowsky, Michael J

    2006-12-01

    Arthrobacter sp. strains are among the most frequently isolated, indigenous, aerobic bacterial genera found in soils. Member of the genus are metabolically and ecologically diverse and have the ability to survive in environmentally harsh conditions for extended periods of time. The genome of Arthrobacter aurescens strain TC1, which was originally isolated from soil at an atrazine spill site, is composed of a single 4,597,686 basepair (bp) circular chromosome and two circular plasmids, pTC1 and pTC2, which are 408,237 bp and 300,725 bp, respectively. Over 66% of the 4,702 open reading frames (ORFs) present in the TC1 genome could be assigned a putative function, and 13.2% (623 genes) appear to be unique to this bacterium, suggesting niche specialization. The genome of TC1 is most similar to that of Tropheryma, Leifsonia, Streptomyces, and Corynebacterium glutamicum, and analyses suggest that A. aurescens TC1 has expanded its metabolic abilities by relying on the duplication of catabolic genes and by funneling metabolic intermediates generated by plasmid-borne genes to chromosomally encoded pathways. The data presented here suggest that Arthrobacter's environmental prevalence may be due to its ability to survive under stressful conditions induced by starvation, ionizing radiation, oxygen radicals, and toxic chemicals.

  11. Estimating cancer risk from 99mTc pyrophosphate imaging for transthyretin cardiac amyloidosis.

    PubMed

    Einstein, Andrew J; Shuryak, Igor; Castaño, Adam; Mintz, Akiva; Maurer, Mathew S; Bokhari, Sabahat

    2018-05-30

    Increasing recognition that transthyretin cardiac amyloidosis (ATTR-CA) is much more common than previously appreciated and the emergence of novel disease-modifying therapeutic agents have led to a paradigm shift in which ATTR-CA screening is considered in high-risk populations, such as patients with heart failure with preserved ejection fraction (HFpEF) or aortic stenosis. Radiation risk from 99m Tc-pyrophosphate ( 99m Tc-PYP) scintigraphy, a test with very high sensitivity and specificity for ATTR-CA, has not been previously determined. Radiation doses to individual organs from 99m Tc-PYP were estimated using models developed by the Medical Internal Radiation Dose Committee and the International Commission on Radiological Protection. Excess future cancer risks were estimated from organ doses, using risk projection models developed by the National Academies and extended by the National Cancer Institute. Excess future risks were estimated for men and women aged 40-80 and compared to total (excess plus baseline) future risks. All-organ excess cancer risks (90% uncertainty intervals) ranged from 5.88 (2.45,11.4) to 12.2 (4.11,26.0) cases per 100,000 patients undergoing 99m Tc-PYP testing, were similar for men and women, and decreased with increasing age at testing. Cancer risks were highest to the urinary bladder, and bladder risk varied nearly twofold depending on which model was used. Excess 99m Tc-PYP-related cancers constituted < 1% of total future cancers to the critical organs. Very low cancer risks associated with 99m Tc-PYP testing suggest a favorable benefit-risk profile for 99m Tc-PYP as a screening test for ATTR-CA in high-risk populations, such as such as patients with HFpEF or aortic stenosis.

  12. Transgenic maize event TC1507: Global status of food, feed, and environmental safety

    PubMed Central

    Baktavachalam, Gajendra B; Delaney, Bryan; Fisher, Tracey L; Ladics, Gregory S; Layton, Raymond J; Locke, Mary EH; Schmidt, Jean; Anderson, Jennifer A; Weber, Natalie N; Herman, Rod A; Evans, Steven L

    2015-01-01

    Maize (Zea mays) is a widely cultivated cereal that has been safely consumed by humans and animals for centuries. Transgenic or genetically engineered insect-resistant and herbicide-tolerant maize, are commercially grown on a broad scale. Event TC1507 (OECD unique identifier: DAS-Ø15Ø7–1) or the Herculex®# I trait, an insect-resistant and herbicide-tolerant maize expressing Cry1F and PAT proteins, has been registered for commercial cultivation in the US since 2001. A science-based safety assessment was conducted on TC1507 prior to commercialization. The safety assessment addressed allergenicity; acute oral toxicity; subchronic toxicity; substantial equivalence with conventional comparators, as well as environmental impact. Results from biochemical, physicochemical, and in silico investigations supported the conclusion that Cry1F and PAT proteins are unlikely to be either allergenic or toxic to humans. Also, findings from toxicological and animal feeding studies supported that maize with TC1507 is as safe and nutritious as conventional maize. Maize with TC1507 is not expected to behave differently than conventional maize in terms of its potential for invasiveness, gene flow to wild and weedy relatives, or impact on non-target organisms. These safety conclusions regarding TC1507 were acknowledged by over 20 regulatory agencies including United States Environment Protection Agency (US EPA), US Department of Agriculture (USDA), Canadian Food Inspection Agency (CFIA), and European Food Safety Authority (EFSA) before authorizing cultivation and/or food and feed uses. A comprehensive review of the safety studies on TC1507, as well as some benefits, are presented here to serve as a reference for regulatory agencies and decision makers in other countries where authorization of TC1507 is or will be pursued. PMID:26018138

  13. Transgenic maize event TC1507: Global status of food, feed, and environmental safety.

    PubMed

    Baktavachalam, Gajendra B; Delaney, Bryan; Fisher, Tracey L; Ladics, Gregory S; Layton, Raymond J; Locke, Mary Eh; Schmidt, Jean; Anderson, Jennifer A; Weber, Natalie N; Herman, Rod A; Evans, Steven L

    2015-01-01

    Maize (Zea mays) is a widely cultivated cereal that has been safely consumed by humans and animals for centuries. Transgenic or genetically engineered insect-resistant and herbicide-tolerant maize, are commercially grown on a broad scale. Event TC1507 (OECD unique identifier: DAS-Ø15Ø7-1) or the Herculex®(#) I trait, an insect-resistant and herbicide-tolerant maize expressing Cry1F and PAT proteins, has been registered for commercial cultivation in the US since 2001. A science-based safety assessment was conducted on TC1507 prior to commercialization. The safety assessment addressed allergenicity; acute oral toxicity; subchronic toxicity; substantial equivalence with conventional comparators, as well as environmental impact. Results from biochemical, physicochemical, and in silico investigations supported the conclusion that Cry1F and PAT proteins are unlikely to be either allergenic or toxic to humans. Also, findings from toxicological and animal feeding studies supported that maize with TC1507 is as safe and nutritious as conventional maize. Maize with TC1507 is not expected to behave differently than conventional maize in terms of its potential for invasiveness, gene flow to wild and weedy relatives, or impact on non-target organisms. These safety conclusions regarding TC1507 were acknowledged by over 20 regulatory agencies including United States Environment Protection Agency (US EPA), US Department of Agriculture (USDA), Canadian Food Inspection Agency (CFIA), and European Food Safety Authority (EFSA) before authorizing cultivation and/or food and feed uses. A comprehensive review of the safety studies on TC1507, as well as some benefits, are presented here to serve as a reference for regulatory agencies and decision makers in other countries where authorization of TC1507 is or will be pursued.

  14. Evaluation of 99mTc labeled diadenosine tetraphosphate as an atherosclerotic plaque imaging agent in experimental models.

    PubMed

    Cao, Wei; Zhang, Yongxue; An, Rui

    2006-01-01

    The potential of 99mTc labeled P1, P4-di (adenosine-5')-tetraphosphate (Ap4A) for imaging experimental atherosclerotic plaques was evaluated in New Zealand white (NZW) rabbits. To label the 99mTc to Ap4A, stannous tartrate solution was used. 99mTc-Ap4A was purified on a Sephadex G-25 column. The radiochemistry purities of 99mTc-Ap4A were 85% to 91%. Biodistribution study revealed 99mTc-Ap4A cleared from blood rapidly. Thirty min after 99mTc-Ap4A administrated on NZW atherosclerotic rabbits, lesion to blood (target/blood, T/B) ratio was 3.17 +/- 1.27, and lesions to normal (target/non-target, T/NT) ratio was 5.23 +/- 1.87. Shadows of atherosclerotic plaques were clearly visible on radioautographic film. Aortas with atherosclerotic plaques also could be seen on ex vivo gamma camera images. Atherosclerotic abdominal aortas were clearly visible on in vivo images 15 min to 3 h after 99mTc-Ap4A administration. 99mTc-labeled Ap4A can be used for rapid noninvasive detection of experimental atherosclerotic plaque.

  15. 75 FR 32458 - TC Ravenswood, LLC v. New York Independent System Operator, Inc.; Notice of Complaint

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-06-08

    ... DEPARTMENT OF ENERGY Federal Energy Regulatory Commission [Docket No. EL10-70-000] TC Ravenswood... 385.206, TC Ravenswood, LLC (Complainant) filed a complaint against New York Independent System Operator, Inc. (NYISO) (Respondent), requesting FERC order the NYISO to reimburse TC Ravenswood, LLC, as...

  16. Fe(II)- and Sulfide-Facilitated Reduction of 99Tc(VII)O4- in Microbially Reduced Hyporheic Zone Sediments

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Lee, Ji-Hoon; Zachara, John M.; Fredrickson, Jim K.

    Redox-reactive, biogeochemical phases generated by reductive microbial activity in hyporheic zone sediments from a dynamic groundwater-river interaction zone were evaluated for their ability to reduce soluble pertechnetate [99Tc(VII)O4-] to less soluble Tc(IV). The sediments were bioreduced by indigenous microorganisms that were stimulated by organic substrate addition in synthetic groundwater with or without sulfate. In most treatments, 20 µmol L-1 initial aqueous Tc(VII) was reduced to near or below detection (3.82×10-9 mol L-1) over periods of days to months in suspensions of variable solids concentrations. Native sediments containing significant lithogenic Fe(II) in various phases were, in contrast, unreactive with Tc(VII). Themore » reduction rates in the bioreduced sediments increased with increases in sediment mass, in proportion to weak acid-extractable Fe(II) and sediment-associated sulfide (AVS). The rate of Tc(VII) reduction was first order with respect to both aqueous Tc(VII) concentration and sediment mass, but correlations between specific reductant concentrations and reaction rate were not found. X-ray microprobe measurements revealed a strong correlation between Tc hot spots and Fe-containing mineral particles in the sediment. However, only a portion of Fe-containing particles were Tc-hosts. The Tc-hot spots displayed a chemical signature (by EDXRF) similar to pyroxene. The application of autoradiography and electron microprobe allowed further isolation of Tc-containing particles that were invariably found to be ca 100 µm aggregates of primary mineral material embedded within a fine-grained phyllosilicate matrix. EXAFS spectroscopy revealed that the Tc(IV) within these were a combination of a Tc(IV)O2-like phase and Tc(IV)-Fe surface clusters, with a significant fraction of a TcSx-like phase in sediments incubated with SO42-. AVS was implicated as a more selective reductant at low solids concentration even though its concentration was below

  17. Fe(II)- and sulfide-facilitated reduction of 99Tc(VII)O4- in microbially reduced hyporheic zone sediments

    NASA Astrophysics Data System (ADS)

    Lee, Ji-Hoon; Zachara, John M.; Fredrickson, James K.; Heald, Steve M.; McKinley, James P.; Plymale, Andrew E.; Resch, Charles T.; Moore, Dean A.

    2014-07-01

    Redox-reactive, biogeochemical phases generated by reductive microbial activity in hyporheic zone sediments from a dynamic groundwater-river interaction zone were evaluated for their ability to reduce soluble pertechnetate [99Tc(VII)O4-] to less soluble Tc(IV). The sediments were bioreduced by indigenous microorganisms that were stimulated by organic substrate addition in synthetic groundwater with or without sulfate. In most treatments, 20 μmol L-1 initial aqueous Tc(VII) was reduced to near or below detection (3.82 × 10-9 mol L-1) over periods of days to months in suspensions of variable solids concentrations. Native sediments containing significant lithogenic Fe(II) in various phases were, in contrast, unreactive with Tc(VII). The reduction rates in the bioreduced sediments increased with increases in sediment mass, in proportion to weak acid-extractable Fe(II) and sediment-associated sulfide (AVS). The rate of Tc(VII) reduction was first order with respect to both aqueous Tc(VII) concentration and sediment mass, but correlations between specific reductant concentrations and reaction rate were not found. X-ray microprobe measurements revealed a strong correlation between Tc hot spots and Fe-containing mineral particles in the sediment. However, only a portion of Fe-containing particles were Tc-hosts. The Tc-hot spots displayed a chemical signature (by EDXRF) similar to pyroxene. The application of autoradiography and electron microprobe allowed further isolation of Tc-containing particles that were invariably found to be ca 100 μm aggregates of primary mineral material embedded within a fine-grained phyllosilicate matrix. EXAFS spectroscopy revealed that the Tc(IV) within these were a combination of a Tc(IV)O2-like phase and Tc(IV)-Fe surface clusters, with a significant fraction of a TcSx-like phase in sediments incubated with SO42-. AVS was implicated as a more selective reductant at low solids concentration even though its concentration was below that

  18. Stability of stabilized 99mTc-D,L-HMPAO stored in vials and syringes.

    PubMed

    Del Carmen Plancha-Mansanet, Maria; Caballero-Calabuig, Elisa; Félix-Fontestad, Jesús; Reyes-Ojeda, María Dolores; Sopena-Novales, Pablo; Abreu-Sánchez, Pedro; Del Carmen Cano-Terol, Maria; Sopena-Monforte, Ramón

    2008-12-01

    Our objective was to determine the stability of stabilized (99m)Tc-hexamethylpropylene amine oxime ((99m)Tc-d,l-HMPAO) dispensed by vial and syringe, with the storage time and labeling activity varied. (99m)Tc-d,l-HMPAO was labeled according to the manufacturer's instructions, but with modification of the (99m)TcO(4)Na activity. Two groups were prepared: 1,110 MBq (30 mCi) and 2,600-3,700 MBq (70.3-100 mCi). Five minutes after labeling, the radiochemical purity (RCP) of the vial content was determined. Afterward, the same activity was distributed into two 2-mL syringes and into the manufacturer's vial. In one of the syringes, the radiopharmaceutical stayed in contact with the needle for 4 h. At 2 and 4 h after labeling, the RCP of the vial and syringe content was checked and compared. The mean RCP of stabilized (99m)Tc-d,l-HMPAO labeled with 1,110 MBq (30 mCi) and stored in a vial decreased from 93.1% at 5 min to 92.1% at 2 h and to 91.1% at 4 h. With storage in a syringe, the RCP decreased from 89.8% at 2 h to 88.7% at 4 h. This diminution increased for labeling with higher activities (2,600-3,700 MBq [70.3-100 mCi]), ranging from 91.4% at 5 min, 89.0% at 2 h, and 85.3% at 4 h in a vial and from 85.9% at 2 h to 80.2% in a syringe. (99m)TcO(2) and secondary (99m)Tc-HMPAO were the main impurities at t = 0. (99m)TcO(4)(-) was an impurity that increased with time in both vials and syringes but significantly so in syringes. All these impurities were higher with labeling activities in the range of 2,600-3,700 MBq (70.3-100 mCi). Contact of the needle with (99m)Tc-d,l-HMPAO sharply decreased the RCP to 57.1% at 4 h. The RCP of stabilized (99m)Tc-d,l-HMPAO decreases significantly in both vials and syringes with high labeling activities. The product is less stable when stored in a syringe than in a vial. The fraction of dose in contact with the needle affects the RCP results.

  19. Solubility Control of Technetium Release from Saltstone by Tc02•xH20

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Cantrell, Kirk J.; Williams, Benjamin D.

    2013-11-12

    Saltstone leaching experiments were conducted using a modified single-pass flow-through method under anoxic conditions. The analytical results of leachates collected from these experiments were evaluated using thermodynamic modeling to determine if the data were consistent with potential solubility controlling phases. The results demonstrate that technetium concentrations in water in contact with Saltstone under anoxic conditions is controlled by the solubility of TcO2•xH2O (likely TcO2•1.6H2O). In our system equilibrium solubility appears to have been reached within two weeks at a concentration of approximately 1.5 x 10-6 M. This concentration is likely to vary as the composition of Saltstone pore fluid evolvesmore » over time. As the pH goes from the initial high values (~12.5-13) to lower values, the solubility of technetium will decrease significantly. The thermodynamic data used to determine the solubility of TcO2•1.6H2O were taken from the tabulation of critically selected thermodynamic data determined by the Nuclear Energy Agency. Solid phase characterization to demonstrate the presence of TcO2•xH2O was not possible due to the low concentrations of technetium in our samples. Previous solid phase characterization studies with cementitious waste forms that were very similar to our Saltstone samples as well as reaction products derived from reductive immobilization of TcO4- by amorphous FeS clearly indicate the presence of TcO2 with varying degrees of hydration. Although, the presence of TcSx or other reduced technetium sulfide phases in our samples cannot be ruled out, release of technetium from Saltstone will be controlled by TcO2•1.6H2O because of its higher solubility. Our results clearly demonstrate that the release mechanism of technetium from Saltstone under reducing conditions is solubility controlled by TcO2•xH2O (likely TcO2•1.6H2O); however, distribution coefficients (Kds), that describe sorption and not solubility, were calculated

  20. Induction magnetometer using a high-Tc superconductor coil

    NASA Astrophysics Data System (ADS)

    Sasada, Ichiro

    2010-05-01

    An induction magnetometer consisting of a search coil and an inverting operational amplifier is simple in structure and in signal transferring mechanism from the magnetic field input to the voltage output. Because this magnetometer is based on Faraday's law of induction, it has a lower cutoff frequency r/(2πL), where r is the resistance of the coil and L is its inductance. An attempt has been made to lower the cutoff frequency of the induction magnetometer by using a high-Tc superconductor coil. With a pancake coil (inner diameter ≈18 cm and outer diameter ≈23 cm, 92 turns, 3.23 mH) made of a Bismuth strontium calcium copper oxide (BSCCO) superconductor tape of 5 mm in width and 0.23 mm in thickness, the cutoff frequency achieved was 1.7 Hz which is much lower than that obtained with a bulky copper search coil which is typically in the range of 10-20 Hz. In the experiment, an inverting amplifier was made with a complementary metal-oxide semiconductor operational amplifier and was immersed in liquid nitrogen together with a BSCCO high-Tc superconducting coil. Discussion is made on the resolution of the induction magnetometer using a high-Tc superconductor search coil.

  1. 99mTc-labeling of HYNIC-conjugated cyclic RGDfK dimer and tetramer using EDDA as coligand.

    PubMed

    Wang, Jianjun; Kim, Young-Seung; Liu, Shuang

    2008-03-01

    In this study, EDDA (ethylenediamine- N, N'-diacetic acid) was used as the coligand for 99mTc-labeling of cyclic RGDfK conjugates: HYNIC-dimer (HYNIC = 6-hydrazinonicotinamide; dimer = E[c(RGDfK)]2) and HYNIC-tetramer (tetramer = E{E[c(RGDfK)]2}2). First, HYNIC-dimer was allowed to react with 99mTcO4 (-) in the presence of excess tricine and stannous chloride to form the intermediate complex [99mTc(HYNIC-dimer)(tricine)2], which was then allowed to react with EDDA to afford [99mTc(HYNIC-dimer)(EDDA)] with high yield (>90%) and high specific activity ( approximately 8.0 Ci/micromol). Under the same radiolabeling conditions, the yield for [99mTc(HYNIC-tetramer)(EDDA)] was always <65%. The results from a mixed-ligand experiment show that there is only one EDDA bonding to the 99mTc-HYNIC core in [99mTc(HYNIC-dimer)(EDDA)]. The athymic nude mice bearing subcutaneous U87MG human glioma xenografts were used to evaluate the impact of EDDA coligand on the biodistribution characteristics and excretion kinetics of the 99mTc-labeled HYNIC-dimer and HYNIC-tetramer. Surprisingly, [99mTc(HYNIC-dimer)(EDDA)] and [99mTc(HYNIC-tetramer)(EDDA)] had almost identical tumor uptake over the 2 h period. The use of EDDA as coligand to replace tricine/TPPTS (TPPTS = trisodium triphenylphosphine-3,3',3''-trisulfonate) did not significantly change the uptake of the 99mTc-labeled HYNIC-dimer in noncancerous organs, such as the liver, kidneys, and lungs; but it did result in a significantly lower kidney uptake for the 99mTc-labeled HYNIC-tetramer due to faster renal excretion. It was also found that the radiotracer tumor uptake decreases in a linear fashion as the tumor size increases. The smaller the tumors are, the higher the tumor uptake is regardless of the identity of radiotracer.

  2. Synthesis and Characterization of Tc(I) Carbonyl Nitrosyl Species Relevant to the Hanford Tank Waste: FY 2016 Status Report

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Hall, Gabriel B.; Chatterjee, Sayandev; Levitskaia, Tatiana G.

    Among long-lived radioactive constituents in the Hanford tank waste, Tc presents a unique challenge in that it exists predominantly in the liquid phase, generally in the anionic form of pertechnetate, TcO 4 -, which is highly volatile at low-activity waste (LAW) vitrification melter temperatures and mobile in the Hanford site’s subsurface environment. The complex behavior of Tc under storage, treatment, and immobilization conditions significantly affects its management options, which to-date remain uncertain. In strongly alkaline environments, Tc exists as pertechnetate, TcO 4 - (oxidation state +7), and in the reduced forms (oxidation state < +7) collectively known as non-pertechnetate species.more » Pertechnetate is a well-characterized, anionic Tc species that can be removed from LAW by anion exchange or solvent extraction methods. There is no definitive information on the origin of the non-pertechnetate Tc species, nor is there a comprehensive description of their composition and behavior. It has been recently proposed that the non-pertechnetate species can comprise Tc(I) metal center and carbonyl or mixed carbonyl nitrosyl ligands stabilizing low-valent Tc. Recent work by our group has significantly expanded this previous work, generating a series of Tc(I) carbonyl compounds and demonstrating that they can be generated from reduction of TcO 4 - in the simulated Hanford tank waste in presence of CO at elevated temperature (Levitskaia et al. 2014). These results are consistent with the previous proposal that [Tc(CO) 3] + species can be present in the Hanford tank waste and suggest that the low Tc(I) oxidation state is stabilized by the π-accepting ability of the CO ligands. The continuation work has been initiated to develop model Tc carbonyl nitrosyl compounds and investigate their potential presence in the Hanford tank wastes. This report summarizes our to-date results.« less

  3. UVB-induced nuclear translocation of TC-PTP by AKT/14-3-3σ axis inhibits keratinocyte survival and proliferation.

    PubMed

    Kim, Mihwa; Morales, Liza D; Baek, Minwoo; Slaga, Thomas J; DiGiovanni, John; Kim, Dae Joon

    2017-10-31

    Understanding protein subcellular localization is important to determining the functional role of specific proteins. T-cell protein tyrosine phosphatase (TC-PTP) contains bipartite nuclear localization signals (NLSI and NLSII) in its C-terminus. We previously have demonstrated that the nuclear form of TC-PTP (TC45) is mainly localized to the cytoplasm in keratinocytes and it is translocated to the nucleus following UVB irradiation. Here, we report that TC45 is translocated by an AKT/14-3-3σ-mediated mechanism in response to UVB exposure, resulting in increased apoptosis and decreased keratinocyte proliferation. We demonstrate that UVB irradiation increased phosphorylation of AKT and induced nuclear translocation of 14-3-3σ and TC45. However, inhibition of AKT blocked nuclear translocation of TC45 and 14-3-3σ. Site-directed mutagenesis of 14-3-3σ binding sites within TC45 showed that a substitution at Threonine 179 (TC45/T179A) effectively blocked UVB-induced nuclear translocation of ectopic TC45 due to the disruption of the direct binding between TC45 and 14-3-3σ. Overexpression of TC45/T179A in keratinocytes resulted in a decrease of UVB-induced apoptosis which corresponded to an increase in nuclear phosphorylated STAT3, and cell proliferation was higher in TC45/T179A-overexpressing keratinocytes compared to control keratinocytes following UVB irradiation. Furthermore, deletion of TC45 NLSII blocked its UVB-induced nuclear translocation, indicating that both T179 and NLSII are required. Taken together, our findings suggest that AKT and 14-3-3σ cooperatively regulate TC45 nuclear translocation in a critical step of an early protective mechanism against UVB exposure that signals the deactivation of STAT3 in order to promote keratinocyte cell death and inhibit keratinocyte proliferation.

  4. .sup.100Mo compounds as accelerator targets for production of .sup.99mTc

    DOEpatents

    Richards, Vernal; Lapi, Suzanne

    2016-09-20

    Methods of synthesizing .sup.100Mo.sub.2C and .sup.99mTcO.sub.4.sup.- are disclosed. Methods of .sup.100Mo.sub.2C generation involve thermally carburizing .sup.100MoO.sub.3. Methods of .sup.99mTcO.sub.4 generation involve proton bombardment of .sup.100Mo.sub.2C in a cyclotron. Yields of .sup.99mTcO.sub.4 can be increased by sintering .sup.100Mo.sub.2C prior to bombardment. The methods also include recycling of .sup.100Mo.sub.2C to form .sup.100MoO.sub.3. SPECT images obtained using .sup.99mTcO.sub.4 generated by the disclosed methods are also presented.

  5. Localization of hemorrhage in a recurrent hemothorax using Tc-99m-sulfur colloid

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Taillefer, R.; Essiambre, R.; Lemieux, R.

    1981-05-01

    Tc99m-sulfur colloid scintigraphy has proven clinically useful in identifying gastrointestinal hemorrhages. The authors describe a patient with recurrent hemothorax under oral anticoagulation therapy in which Tc-99m-sulfur colloid imaging was used to determine the site of bleeding.

  6. Dietary n-3 PUFA affect TcR-mediated activation of purified murine T cells and accessory cell function in co-cultures

    PubMed Central

    CHAPKIN, R S; ARRINGTON, J L; APANASOVICH, T V; CARROLL, R J; MCMURRAY, D N

    2002-01-01

    Diets enriched in n-3 polyunsaturated fatty acids (PUFA) suppress several functions of murine splenic T cells by acting directly on the T cells and/or indirectly on accessory cells. In this study, the relative contribution of highly purified populations of the two cell types to the dietary suppression of T cell function was examined. Mice were fed diets containing different levels of n-3 PUFA; safflower oil (SAF; control containing no n-3 PUFA), fish oil (FO) at 2% and 4%, or 1% purified docosahexaenoic acid (DHA) for 2 weeks. Purified (>90%) T cells were obtained from the spleen, and accessory cells (>95% adherent, esterase-positive) were obtained by peritoneal lavage. Purified T cells or accessory cells from each diet group were co-cultured with the alternative cell type from every other diet group, yielding a total of 16 different co-culture combinations. The T cells were stimulated with either concanavalin A (ConA) or antibodies to the T cell receptor (TcR)/CD3 complex and the costimulatory molecule CD28 (αCD3/αCD28), and proliferation was measured after four days. Suppression of T cell proliferation in the co-cultures was dependent upon the dose of dietary n-3 PUFA fed to mice from which the T cells were derived, irrespective of the dietary treatment of accessory cell donors. The greatest dietary effect was seen in mice consuming the DHA diet (P = 0·034 in the anova; P = 0·0053 in the Trend Test), and was observed with direct stimulation of the T cell receptor and CD28 costimulatory ligand, but not with ConA. A significant dietary effect was also contributed accessory cells (P = 0·033 in the Trend Test). We conclude that dietary n-3 PUFA affect TcR-mediated by T cell activation by both direct and indirect (accessory cell) mechanisms. PMID:12296847

  7. (99m)Tc-bioorthogonal click chemistry reagent for in vivo pretargeted imaging.

    PubMed

    García, María Fernanda; Zhang, Xiuli; Shah, Manankumar; Newton-Northup, Jessica; Cabral, Pablo; Cerecetto, Hugo; Quinn, Thomas

    2016-03-15

    Metal-free click chemistry has become an important tool for pretargeted approaches in the molecular imaging field. The application of bioorthogonal click chemistry between a pretargeted trans-cyclooctene (TCO) derivatized monoclonal antibody (mAb) and a (99m)Tc-modified 1,2,4,5-tetrazine for tumor imaging was examined in vitro and in vivo. The HYNIC tetrazine compound was synthesized and structurally characterized, confirming its identity. Radiolabeling studies demonstrated that the HYNIC tetrazine was labeled with (99m)Tc at an efficiency of >95% and was radiochemically stable. (99m)Tc-HYNIC tetrazine reacted with the TCO-CC49 mAb in vitro demonstrating its selective reactivity. In vivo biodistribution studies revealed non-specific liver and GI uptake due to the hydrophobic property of the compound, however pretargeted SPECT imaging studies demonstrated tumor visualization confirming the success of the cycloaddition reaction in vivo. These results demonstrated the potential of (99m)Tc-HYNIC-tetrazine for tumor imaging with pretargeted mAbs. Copyright © 2016 Elsevier Ltd. All rights reserved.

  8. Measurement of pulmonary epithelial permeability with /sup 99m/Tc-DTPA aerosol

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Coates, G.; O'Brodovich, H.

    1986-10-01

    The rate at which inhaled aerosol of /sup 99m/Tc-diethylenetriamine pentaacetate (DTPA) leaves the lung by diffusion into the vascular space can be measured with a gamma camera or simple probe. In normal humans, /sup 99m/Tc-DTPA clears from the lung with a half time of about 80 minutes. Many acute and chronic conditions that alter the integrity of the pulmonary epithelium cause an increased clearance rate. Thus cigarette smoking, alveolitis from a variety of causes, adult respiratory distress syndrome (ARDS), and hyaline membrane disease (HMD) in the infant have all been shown to be associated with rapid pulmonary clearance of /supmore » 99m/Tc-DTPA. Rapid clearance is also promoted by increased lung volume and decreased surfactant activity. Although the mechanism of increased clearance in pathological states is not known, the /sup 99m/Tc-DTPA lung-clearance technique has great potential clinically, particularly in patients at risk from ARDS and HMD and in the diagnosis and follow-up of alveolitis. 58 references.« less

  9. SPECT measurements with /sup 99m/Tc-HM-PAO in focal epilepsy

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Ryding, E.; Rosen, I.; Elmqvist, D.

    1988-12-01

    The ability of SPECT measurements with (/sup 99m/Tc)-HM-PAO (Ceretec) to find the location of the epileptic focus was studied in patients under consideration for neurosurgical treatment for therapy-resistant focal epilepsy. The location of low (/sup 99m/Tc)-HM-PAO uptake regions found at interictal measurements, and of high (/sup 99m/Tc)-HM-PAO uptake regions found at ictal measurements, was compared to the findings of extensive ictal and interictal EEG examinations, and to the results of CT and MRT. While EEG revealed focal epileptic activity in all of the 14 patients, SPECT showed regional abnormalities in 13 (93%). CT and MRT showed abnormal findings in 30%.

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

    PubMed

    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

  11. Photothermal measurements of high Tc superconductors

    NASA Astrophysics Data System (ADS)

    Fanton, J. T.; Mitzi, D. B.; Kapitulnik, A.; Khuri-Yakub, B. T.; Kino, G. S.; Gazit, D.; Feigelson, R. S.

    1989-08-01

    We demonstrate a photothermal method for making point measurements of the thermal conductivities of high Tc superconductors. Images made at room temperature on polycrystalline materials show the thermal inhomogeneities. Measurements on single-crystal Bi2Sr2CaCu2Ox compounds reveal a very large anisotropy of about 7:1 in the thermal conductivity.

  12. Design and performance of an automated radionuclide separator: its application on the determination of ⁹⁹Tc in groundwater.

    PubMed

    Chung, Kun Ho; Choi, Sang Do; Choi, Geun Sik; Kang, Mun Ja

    2013-11-01

    A modular automated radionuclide separator for (99)Tc (MARS Tc-99) has been developed for the rapid and reproducible separation of technetium in groundwater samples. The control software of MARS Tc-99 was developed in the LabView programming language. An automated radiochemical method for separating (99)Tc was developed and validated by the purification of (99m)Tc tracer solution eluted from a commercial (99)Mo/(99m)Tc generator. The chemical recovery and analytical time for this radiochemical method were found to be 96 ± 2% and 81 min, respectively. Copyright © 2013 Elsevier Ltd. All rights reserved.

  13. Tc-99m imaging in thyroidectomized differentiated thyroid cancer patients immediately before I-131 treatment.

    PubMed

    Tsai, Chi-Jung; Cheng, Cheng-Yi; Shen, Daniel Hueng-Yuan; Kuo, Shou Jen; Wang, Lien-Yen; Lee, Chiang-Hsuan; Wang, Jhi-Joung; Chang, Ming-Che; Huang, Wen-Sheng

    2016-02-01

    The aim of this study was to evaluate the clinical role of technetium-99m pertechnetate (Tc-99m) imaging in thyroidectomized differentiated thyroid cancer patients immediately before radioiodine-131 (I-131) treatment (Tx). Eighty-six consecutive post-total-thyroidectomy patients (15 men, 71 women; mean age: 46.8 years) with pathologically diagnosed differentiated thyroid cancer were retrospectively studied. Tc-99m imaging immediately before I-131 Tx using both patient-based and lesion-based measurements were analyzed and were further compared with those of post-Tx I-131 whole-body scans. For patients with unequivocally positive Tc-99m uptake, the sensitivity was 77% (patient-based) and 59% (site-based). The positive predictive value (PPV) was 100% for both patient-based and site-based measurements. If equivocal Tc-99m uptake was counted as positive, the sensitivity was 83 and 67%, and the PPV was 100 and 99% for patient-based and site-based measurements, respectively. (a) To increase sensitivity yet maintaining high PPV, equivocal Tc-99m uptake should be considered a positive finding. (b) The nearly 100% PPV of Tc-99m imaging immediately before I-131 Tx for remnant detection suggests that Tc-99m imaging not only serves as an alternative to low-dose I-131 scanning in the low-risk post-thyroidectomy patients but also provides a clue for the subsequent I-131 therapeutic dosage and even for the outcome prediction.

  14. Thoracic Injuries in earthquake-related versus non-earthquake-related trauma patients: differentiation via Multi-detector Computed Tomography

    PubMed Central

    Dong, Zhi-hui; Yang, Zhi-gang; Chen, Tian-wu; Chu, Zhi-gang; Deng, Wen; Shao, Heng

    2011-01-01

    PURPOSE: Massive earthquakes are harmful to humankind. This study of a historical cohort aimed to investigate the difference between earthquake-related crush thoracic traumas and thoracic traumas unrelated to earthquakes using a multi-detector Computed Tomography (CT). METHODS: We retrospectively compared an earthquake-exposed cohort of 215 thoracic trauma crush victims of the Sichuan earthquake to a cohort of 215 non-earthquake-related thoracic trauma patients, focusing on the lesions and coexisting injuries to the thoracic cage and the pulmonary parenchyma and pleura using a multi-detector CT. RESULTS: The incidence of rib fracture was elevated in the earthquake-exposed cohort (143 vs. 66 patients in the non-earthquake-exposed cohort, Risk Ratio (RR) = 2.2; p<0.001). Among these patients, those with more than 3 fractured ribs (106/143 vs. 41/66 patients, RR = 1.2; p<0.05) or flail chest (45/143 vs. 11/66 patients, RR = 1.9; p<0.05) were more frequently seen in the earthquake cohort. Earthquake-related crush injuries more frequently resulted in bilateral rib fractures (66/143 vs. 18/66 patients, RR = 1.7; p<0.01). Additionally, the incidence of non-rib fracture was higher in the earthquake cohort (85 vs. 60 patients, RR = 1.4; p<0.01). Pulmonary parenchymal and pleural injuries were more frequently seen in earthquake-related crush injuries (117 vs. 80 patients, RR = 1.5 for parenchymal and 146 vs. 74 patients, RR = 2.0 for pleural injuries; p<0.001). Non-rib fractures, pulmonary parenchymal and pleural injuries had significant positive correlation with rib fractures in these two cohorts. CONCLUSIONS: Thoracic crush traumas resulting from the earthquake were life threatening with a high incidence of bony thoracic fractures. The ribs were frequently involved in bilateral and severe types of fractures, which were accompanied by non-rib fractures, pulmonary parenchymal and pleural injuries. PMID:21789386

  15. A system of {sup 99m}Tc production based on distributed electron accelerators and thermal separation

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Bennett, R.G.; Christian, J.D.; Petti, D.A.

    1999-04-01

    A system has been developed for the production of {sup 99m}Tc based on distributed electron accelerators and thermal separation. The radioactive decay parent of {sup 99m}Tc, {sup 99}Mo, is produced from {sup 100}Mo by a photoneutron reaction. Two alternative thermal separation processes have been developed to extract {sup 99m}Tc. Experiments have been performed to verify the technical feasibility of the production and assess the efficiency of the extraction processes. A system based on this technology enables the economical supply of {sup 99m}Tc for a large nuclear pharmacy. Twenty such production centers distributed near major metropolitan areas could produce the entiremore » US supply of {sup 99m}Tc at a cost less than the current subsidized price.« less

  16. 99Tc atom counting by quadrupole ICP-MS. Optimisation of the instrumental response

    NASA Astrophysics Data System (ADS)

    Más, José L.; Garcia-León, Manuel; Bolívar, Juan P.

    2002-05-01

    In this paper, an extensive work is done on the specific tune of a conventional ICP-MS for 99Tc atom counting. For this, two methods have been used and compared: the partial variable control method and the 5D Simplex method. Instrumental limits of detection of 0.2 and 0.8 ppt, respectively, were obtained. They are noticeably lower than that found with the automatic tune method of the spectrometer, 47 ppt, which shows the need of a specific tune when very low levels of 99Tc have to be determined. A study is presented on the mass interferences for 99Tc. Our experiments show that the formation of polyatomic atoms or refractory oxides as well as 98Mo hydrides seem to be irrelevant for 99Tc atom counting. The opposite occurs with the presence of isobaric interferences, i.e. 99Ru, and the effect of abundance sensitivity, or low-mass resolution, which can modify the response at m/ z=99 to a non-negligible extent.

  17. Diagnostic accuracy of [99mTc]Tc-Sestamibi in the assessment of thyroid nodules.

    PubMed

    Yordanova, Anna; Mahjoob, Soha; Lingohr, Philipp; Kalff, Jörg; Türler, Andreas; Palmedo, Holger; Biersack, Hans-Jürgen; Kristiansen, Glen; Farahati, Jamshid; Essler, Markus; Ahmadzadehfar, Hojjat

    2017-11-07

    [ 99m Tc]Tc-Sestamibi (MIBI) is an increasingly used tool for evaluation of thyroid nodules. However, there is a lack of evidence about the accuracy of this method in the European population. The aim of this study was to assess the utility of MIBI for the differentiation of thyroid nodules in a large cohort. 161 patients underwent MIBI, followed by a thyroidectomy. We used a dual phase MIBI protocol. Interpretation of the images included a scoring system from 0 (absent) to 3 (increased); this was to provide a scale for the uptake of the thyroid nodule in comparison to the paranodular tissue. Additionally, we evaluated the tracer uptake trend in late images compared to early images. We used the final histopathology as the reference standard. Scores 0-1 in early images, scores 0-2 in late images, and an absence of increasing uptake in the thyroid nodule in late images, showed the best predictive values to exclude malignancy, respectively (negative predictive value (NPV) 89%). Highest sensitivity (91%) for malignant nodules was evident in early images with a score 1-3. Highest specificity (91%) was obtained when the negative was defined as an absence of uptake-increase, in the late images. This study confirms that the most valuable feature of MIBI is the high NPV. Thus, with the appropriate interpretation method, high sensitivity and specificity, and moderate PPV can be obtained.

  18. Development of (99m)Tc-Labeled Pyridyl Benzofuran Derivatives To Detect Pancreatic Amylin in Islet Amyloid Model Mice.

    PubMed

    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.

  19. Evaluation of lymphoma in a cat using 99mTc-sestamibi.

    PubMed

    Lenard, Zoe M; Zuber, Richard M; Nicoll, Robert G; O'Hara, Amanda J; Lester, Nola V

    2005-01-01

    This report describes the evaluation of cutaneous lymphoma in a cat using 99mTc-sestamibi. A mass in the left pes with extension to the left popliteal lymph node was diagnosed as B-cell lymphoma. Thoracic and abdominal radiography and abdominal ultrasound were unremarkable. Scintigraphy using 99mTc-sestamibi confirmed the lesion was confined to the left hind leg, and the leg was amputated. The cat made a full recovery.

  20. Bone marrow uptake of 99mTc-MIBI in patients with multiple myeloma.

    PubMed

    Fonti, R; Del Vecchio, S; Zannetti, A; De Renzo, A; Di Gennaro, F; Catalano, L; Califano, C; Pace, L; Rotoli, B; Salvatore, M

    2001-02-01

    In a previous study, we showed the ability of technetium-99m methoxyisobutylisonitrile (99mTc-MIBI) scan to identify active disease in patients with multiple myeloma (Eur J Nucl Med 1998; 25: 714-720). In particular, a semiquantitative score of the extension and intensity of bone marrow uptake was derived and correlated with both the clinical status of the disease and plasma cell bone marrow infiltration. In order to estimate quantitatively 99mTc-MIBI bone marrow uptake and to verify the intracellular localization of the tracer, bone marrow samples obtained from 24 multiple myeloma patients, three patients with monoclonal gammopathy of undetermined significance (MGUS) and two healthy donors were studied for in vitro uptake. After centrifugation over Ficoll-Hypaque gradient, cell suspensions were incubated with 99mTc-MIBI and the uptake was expressed as the percentage of radioactivity specifically retained within the cells. The cellular localization of the tracer was assessed by micro-autoradiography. Twenty-two out of 27 patients underwent 99mTc-MIBI scan within a week of bone marrow sampling. Whole-body images were obtained 10 min after intravenous injection of 555 MBq of the tracer; the extension and intensity of 99mTc-MIBI uptake were graded using the semiquantitative score. A statistically significant correlation was found between in vitro uptake of 99mTc-MIBI and both plasma cell infiltration (Pearson's coefficient of correlation r=0.69, P<0.0001) and in vivo score (Spearman rank correlation coefficient r=0.60, P<0.01). No specific tracer uptake was found in bone marrow samples obtained from the two healthy donors. Micro-autoradiography showed localization of 99mTc-MIBI inside the plasma cells infiltrating the bone marrow. Therefore, our findings show that the degree of tracer uptake both in vitro and in vivo is related to the percentage of infiltrating plasma cells which accumulate the tracer in their inner compartments.

  1. Safe cervical spine clearance in adult obtunded blunt trauma patients on the basis of a normal multidetector CT scan--a meta-analysis and cohort study.

    PubMed

    Raza, Mushahid; Elkhodair, Samer; Zaheer, Asif; Yousaf, Sohail

    2013-11-01

    A true gold standard to rule out a significant cervical spine injury in subset of blunt trauma patients with altered sensorium is still to be agreed upon. The objective of this study is to determine whether in obtunded adult patients with blunt trauma, a clinically significant injury to the cervical spine be ruled out on the basis of a normal multidetector cervical spine computed tomography. Comprehensive database search was conducted to include all the prospective and retrospective studies on blunt trauma patients with altered sensorium undergoing cervical spine multidetector CT scan as core imaging modality to "clear" the cervical spine. The studies used two main gold standards, magnetic resonance imaging of the cervical spine and/or prolonged clinical follow-up. The data was extracted to report true positive, true negatives, false positives and false negatives. Meta-analysis of sensitivity, specificity, negative and positive predictive values was performed using Meta Analyst Beta 3.13 software. We also performed a retrospective investigation comparing a robust clinical follow-up and/or cervical spine MR findings in 53 obtunded blunt trauma patients, who previously had undergone a normal multidetector CT scan of the cervical spine reported by a radiologist. A total of 10 studies involving 1850 obtunded blunt trauma patients with initial cervical spine CT scan reported as normal were included in the final meta-analysis. The cumulative negative predictive value and specificity of cervical spine CT of the ten studies was 99.7% (99.4-99.9%, 95% confidence interval). The positive predictive value and sensitivity was 93.7% (84.0-97.7%, 95% confidence interval). In the retrospective review of our obtunded blunt trauma patients, none was later diagnosed to have significant cervical spine injury that required a change in clinical management. In a blunt trauma patient with altered sensorium, a normal cervical spine CT scan is conclusive to safely rule out a clinically

  2. Synthesis and evaluation of novel Tc-99m labeled NGR-containing hexapeptides as tumor imaging agents.

    PubMed

    Kim, Dae-Weung; Kim, Woo Hyoung; Kim, Myoung Hyoun; Kim, Chang Guhn

    2015-02-01

    Asparagine-glycine-arginine (NGR)-containing peptides targeting aminopeptidase N (APN)/CD13 can be an excellent candidate for targeting ligands in molecular tumor imaging. In this study, we developed two NGR-containing hexapeptides, and evaluated the diagnostic performance of Tc-99m labeled hexapeptides as molecular imaging agents in an HT-1080 fibrosarcoma-bearing murine model. Peptides were synthesized using Fmoc solid-phase peptide synthesis. Radiochemical purity of Tc-99m was evaluated using instant thin-layer chromatography. The uptake of two NGR-containing hexapeptides within HT-1080 cells was evaluated in vitro. In HT-1080 fibrosarcoma tumor-bearing mice, gamma images were acquired. A biodistribution study was performed to calculate percentage of the injected dose per gram of tissue (%ID/g). Two hexapeptides, glutamic acid-cysteine-glycine (ECG)-NGR and NGR-ECG were successfully synthesized. After radiolabeling procedures with Tc-99m, the complexes Tc-99m hexapeptides were prepared in high yield. The uptake of Tc-99m ECG-NGR within the tumor cells had been assured by in vitro studies. The gamma camera imaging in the murine model showed that Tc-99m ECG-NGR was accumulated substantially in the subcutaneously engrafted tumor. However, Tc-99m NGR-ECG was accumulated minimally in the tumor. Two NGR-containing hexapeptides, ECG-NGR and NGR-ECG were developed as molecular imaging agents to target APN/CD13 in HT-1080 fibrosarcoma. Tc-99m ECG-NGR showed a significant uptake in the tumor, and it is a good candidate for tumor imaging. Copyright © 2015 John Wiley & Sons, Ltd.

  3. Early detection of rheumatoid arthritis in rats and humans with 99mTc-3PRGD2 scintigraphy: imaging synovial neoangiogenesis.

    PubMed

    Wu, Yu; Zhang, Guojian; Wang, Xiangcheng; Zhao, Zhenfang; Wang, Tao; Wang, Xuemei; Li, Xiao-Feng

    2017-01-24

    To validate 99mTc-labeled arginylglycylaspartic acid (99mTc-3PRGD2) scintigraphy as a means to image synovial neoangiogenesis in joints afflicted by rheumatoid arthritis and to investigate its potential in the early detection and management of rheumatoid arthritis. Rheumatoid arthritis and osteoarthritis were generated in Sprague Dawley rats by type II collagen immunization and papain injection, respectively. Rats were imaged with 99mTc-3PRGD2 and 99mTc- methyl diphosphonate (99mTc MDP). X-ray images were also obtained and assessed by a radiologist. Immunohistochemistry of αvβ3 and CD31confirmed the onset of synovial neoangiogenesis. The effect of bevacizumab on rheumatoid arthritis was followed with 99mTc-3PRGD2 scintigraphy. A patient with rheumatoid arthritis and a healthy volunteer were scanned with 99mTc-3PRGD2. Two weeks after immunization, a significant increase in 99mTc-3PRGD2 was observed in the joints of the rheumatoid arthritis model though uptake in osteoarthritis model and untreated controls was low. 99mTc-MDP whole body scans failed to distinguish early rheumatoid arthritis joints from healthy controls. The expression of αvβ3 and CD31was significantly higher in the joints of rheumatoid arthritis rats compared to normal controls. In serial 99mTc-3PRGD2 scintigraphy studies, 99mTc-3PRGD2 uptake increased in parallel with disease progression. Bevacizumab anti-angiogenetic therapy both improved the symptoms of the rheumatoid arthritis rats and significantly decreased 99mTc-3PRGD2 uptake. Significantly higher 99mTc-3PRGD2 accumulation was also observed in rheumatoid arthritis joints in the patient. Our findings indicate that 99mTc-3PRGD2 scintigraphy could detect early rheumatoid arthritis by imaging the associated synovial neoangiogenesis, and may be useful in disease management.

  4. Evaluation of New Tc-99m-Labeled Arg-X-Asp-Conjugated Alpha-Melanocyte Stimulating Hormone Peptides for Melanoma Imaging

    PubMed Central

    Flook, Adam M.; Yang, Jianquan; Miao, Yubin

    2013-01-01

    The purpose of this study was to examine the melanoma targeting and imaging properties of two new 99mTc-labeled Arg-X-Asp-conjugated alpha-melanocyte stimulating hormone (α-MSH) peptides. RTD-Lys-(Arg11)CCMSH {c[Asp-Arg-Thr-Asp-DTyr]-Lys-Cys-Cys-Glu-His-DPhe-Arg-Trp-Cys-Arg-Pro-Val-NH2} and RVD-Lys-(Arg11)CCMSH peptides were synthesized and their melanocortin-1 (MC1) receptor binding affinities were determined in B16/F1 melanoma cells. The biodistribution and melanoma imaging properties of 99mTc-RTD-Lys-(Arg11)CCMSH and 99mTc-RVD-Lys-(Arg11)CCMSH were determined in B16/F1 melanoma-bearing C57 mice. The IC50 values of RTD-Lys-(Arg11)CCMSH and RVD-Lys-(Arg11)CCMSH were 0.7 ± 0.07 and 1.0 ± 0.3 nM in B16/F1 melanoma cells. Both 99mTc-RTD-Lys-(Arg11)CCMSH and 99mTc-RVD-Lys-(Arg11)CCMSH displayed high melanoma uptake. 99mTc-RTD-Lys-(Arg11)CCMSH exhibited the peak tumor uptake of 18.77 ± 5.13% ID/g at 2 h post-injection, whereas 99mTc-RVD-Lys-(Arg11)CCMSH reached the peak tumor uptake of 19.63 ± 4.68% ID/g at 4 h post-injection. Both 99mTc-RTD-Lys-(Arg11)CCMSH and 99mTc-RVD-Lys-(Arg11)CCMSH showed low accumulation in normal organs (<1.7% ID/g) except for the kidneys at 2 h post-injection. The renal uptake of 99mTc-RTD-Lys-(Arg11)CCMSH and 99mTc-RVD-Lys-(Arg11)CCMSH was 135.14 ± 23.62 and 94.01 ± 18.31% ID/g at 2 h post-injection, respectively. The melanoma lesions were clearly visualized by SPECT/CT using either 99mTc-RTD-Lys-(Arg11)CCMSH or 99mTc-RVD-Lys-(Arg11)CCMSH as an imaging probe at 2 h post-injection. Overall, the introduction of Thr or Val residue retained high melanoma uptake of 99mTc-RTD-Lys-(Arg11)CCMSH and 99mTc-RVD-Lys-(Arg11)CCMSH. However, high renal uptake of 99mTc-RTD-Lys-(Arg11)CCMSH and 99mTc-RVD-Lys-(Arg11)CCMSH need to be reduced to facilitate their future applications. PMID:23885640

  5. Evaluation of new Tc-99m-labeled Arg-X-Asp-conjugated α-melanocyte stimulating hormone peptides for melanoma imaging.

    PubMed

    Flook, Adam M; Yang, Jianquan; Miao, Yubin

    2013-09-03

    The purpose of this study was to examine the melanoma targeting and imaging properties of two new (99m)Tc-labeled Arg-X-Asp-conjugated α-melanocyte stimulating hormone (α-MSH) peptides. RTD-Lys-(Arg(11))CCMSH {c[Asp-Arg-Thr-Asp-DTyr]-Lys-Cys-Cys-Glu-His-DPhe-Arg-Trp-Cys-Arg-Pro-Val-NH2} and RVD-Lys-(Arg(11))CCMSH peptides were synthesized, and their melanocortin-1 (MC1) receptor binding affinities were determined in B16/F1 melanoma cells. The biodistribution and melanoma imaging properties of (99m)Tc-RTD-Lys-(Arg(11))CCMSH and (99m)Tc-RVD-Lys-(Arg(11))CCMSH were determined in B16/F1 melanoma-bearing C57 mice. The IC50 values of RTD-Lys-(Arg(11))CCMSH and RVD-Lys-(Arg(11))CCMSH were 0.7 ± 0.07 and 1.0 ± 0.3 nM in B16/F1 melanoma cells. Both (99m)Tc-RTD-Lys-(Arg(11))CCMSH and (99m)Tc-RVD-Lys-(Arg(11))CCMSH displayed high melanoma uptake. (99m)Tc-RTD-Lys-(Arg(11))CCMSH exhibited the highest tumor uptake of 18.77 ± 5.13% ID/g at 2 h postinjection, whereas (99m)Tc-RVD-Lys-(Arg(11))CCMSH reached the highest tumor uptake of 19.63 ± 4.68% ID/g at 4 h postinjection. Both (99m)Tc-RTD-Lys-(Arg(11))CCMSH and (99m)Tc-RVD-Lys-(Arg(11))CCMSH showed low accumulation in normal organs (<1.7% ID/g) except for the kidneys at 2 h postinjection. The renal uptake of (99m)Tc-RTD-Lys-(Arg(11))CCMSH and (99m)Tc-RVD-Lys-(Arg(11))CCMSH was 135.14 ± 23.62 and 94.01 ± 18.31% ID/g at 2 h postinjection, respectively. The melanoma lesions were clearly visualized by single-photon emission computed tomography (SPECT)/CT using either (99m)Tc-RTD-Lys-(Arg(11))CCMSH or (99m)Tc-RVD-Lys-(Arg(11))CCMSH as an imaging probe at 2 h postinjection. Overall, the introduction of Thr or Val residue retained high melanoma uptake of (99m)Tc-RTD-Lys-(Arg(11))CCMSH and (99m)Tc-RVD-Lys-(Arg(11))CCMSH. However, high renal uptake of (99m)Tc-RTD-Lys-(Arg(11))CCMSH and (99m)Tc-RVD-Lys-(Arg(11))CCMSH need to be reduced to facilitate their future applications.

  6. Monoanionic 99mTc-tricarbonyl-aminopolycarboxylate complexes with uncharged pendant groups: Radiosynthesis and evaluation as potential renal tubular tracers.

    PubMed

    Lipowska, Malgorzata; Klenc, Jeffrey; Jarkas, Nashwa; Marzilli, Luigi G; Taylor, Andrew T

    2017-04-01

    99m Tc(CO) 3 -nitrilotriacetic acid, 99m Tc(CO) 3 (NTA), is a new renal tubular agent with pharmacokinetic properties comparable to those of 131 I-OIH but the clearance of 99m Tc(CO) 3 (NTA) and 131 I-OIH is still less than the clearance of PAH, the gold standard for the measurement of effective renal plasma flow. At physiological pH, dianionic 99m Tc(CO) 3 (NTA) has a mononegative inner metal-coordination sphere and a mononegative uncoordinated carboxyl group. To evaluate alternate synthetic approaches, we assessed the importance of an uncoordinated carboxyl group, long considered essential for tubular transport, by evaluating the pharmacokinetics of three analogs with the 99m Tc(CO) 3 (NTA) metal-coordination sphere but with uncharged pendant groups. 99m Tc(CO) 3 complexes with N-(2-acetamido)iminodiacetic acid (ADA), N-(2-hydroxyethyl)iminodiacetic acid (HDA) and N-(fluoroethyl)iminodiacetic acid (FEDA) were prepared using a tricarbonyl kit and isolated by HPLC. The pharmacokinetics were evaluated in Sprague-Dawley rats, with 131 I-OIH as an internal control; urine was analyzed for metabolites. Plasma protein binding and erythrocyte uptake were determined from the 10min blood samples. Re(CO) 3 (FEDA), the analog of 99m Tc(CO) 3 (FEDA), was prepared and characterized. 99m Tc(CO) 3 (ADA), 99m Tc(CO) 3 (HDA) and 99m Tc(CO) 3 (FEDA) were efficiently prepared as a single species with high radiochemical purities (>99%). These new monoanionic 99m Tc(CO) 3 tracers with uncharged dangling groups all showed rapid blood clearance and high specificity for renal excretion. Activity in the urine, as a percent of 131 I-OIH at 10 and 60min, was 96% and 99% for ADA, 96% and 100% for HDA, and 100% and 99% for FEDA, respectively. Each new tracer was excreted unchanged in the urine. The Re(CO) 3 (FEDA) structure adds compelling evidence that such 99m Tc(CO) 3 (NTA) analogs have metal-coordination spheres identical to that of 99m Tc(CO) 3 (NTA). New tracers lacking the negatively

  7. Long-term study of 99Tc in the marine environment on the Swedish west coast.

    PubMed

    Lindahl, P; Ellmark, C; Gäfvert, T; Mattsson, S; Roos, P; Holm, E; Erlandsson, B

    2003-01-01

    The activity concentration of (99)Tc in brown seaweed (Fucus vesiculosus and Fucus serratus) and seawater were analysed in samples collected in 1991, 1995 and 2001 at several stations along the Swedish west coast. In addition to these locations, a well-defined site (Särdal, 56.76 degrees N, 12.63 degrees E) was included with (99)Tc activity concentration data in seaweed from 1967 to 2000. Over the years, the major source of (99)Tc in the coastal waters of western Sweden has been the radioactive liquid discharge from the nuclear fuel reprocessing plant in Sellafield (UK) transported via ocean currents in the North Sea. The (99)Tc activity concentration in seaweed at the Särdal site increased from approximately 30 Bq kg(-1) up to 230 Bq kg(-1) (dry weight) between 1997 and 2000 due to the Sellafield EARP (Enhanced Actinide Removal Plant) discharges in 1995-1996, yielding an approximate transport time of 4-5 years between the Irish Sea and the Kattegat. Due to the very sharp gradient in (99)Tc concentration between the Baltic Sea and the North Sea, (99)Tc is presently one of the best transit tracers for the recent ventilation events in the Baltic Sea.

  8. Multidetector CT of Surgically Proven Blunt Bowel and Mesenteric Injury.

    PubMed

    Bates, David D B; Wasserman, Michael; Malek, Anita; Gorantla, Varun; Anderson, Stephan W; Soto, Jorge A; LeBedis, Christina A

    2017-01-01

    Blunt traumatic injury is one of the leading causes of morbidity and mortality in the United States. Unintentional injury represents the leading cause of death in the United States for all persons between the ages of 1 and 44 years. In the setting of blunt abdominal trauma, the reported rate of occurrence of bowel and mesenteric injuries ranges from 1% to 5%. Despite the relatively low rate of blunt bowel and mesenteric injury in patients with abdominal and pelvic trauma, delays in diagnosis are associated with increased rates of sepsis, a prolonged course in the intensive care unit, and increased mortality. During the past 2 decades, as multidetector computed tomography (CT) has emerged as an essential tool in emergency radiology, several direct and indirect imaging features have been identified that are associated with blunt bowel and mesenteric injury. The imaging findings in cases of blunt bowel and mesenteric injury can be subtle and may be seen in the setting of multiple complex injuries, such as multiple solid-organ injuries and spinal fractures. Familiarity with the various imaging features of blunt bowel and mesenteric injury, as well as an understanding of their clinical importance with regard to the care of the patient, is essential to making a timely diagnosis. Once radiologists are familiar with the spectrum of findings of blunt bowel and mesenteric injury, they will be able to make timely diagnoses that will lead to improved patient outcomes. © RSNA, 2017.

  9. Sixteen-slice multidetector computed tomographic virtual cystoscopy in the evaluation of a patient with suspected bladder tumor and history of bladder carcinoma operation.

    PubMed

    Basak, Muzaffer; Ozkurt, Huseyin; Tanriverdi, Orhan; Cay, Esra; Aydin, Mustafa; Miroglu, Cengiz

    2009-01-01

    The purpose of this study was to evaluate the use of virtual cystoscopy performed with multidetector computed tomography (CT) in patients with suspected bladder tumors and histories of bladder carcinoma operation. Thirty-six patients (29 men and 7 women) with a mean age of 66 years (range, 24-88 years) with suspected bladder tumors and histories of bladder carcinoma operation were included in this prospective study. Virtual cystoscopy was performed by 16-slice multidetector CT scanner. The bladder was filled with diluted contrast material solution through a Foley catheter. Then, all patients underwent conventional cystoscopy examination. Two reviewers found 18 lesions detected by virtual cystoscopy by consensus, whereas 19 lesions were depicted by conventional cystoscopy. At virtual and conventional cystoscopies, the conditions of 3 patients, 2 with chronic inflammations and 1 with foreign body reaction, were wrongly diagnosed as tumors. At conventional cystoscopy, one patient's result was wrongly interpreted as normal. In pathologic evaluation, all tumors were diagnosed as transitional cell carcinoma. Bladder tumor can be noninvasively diagnosed using virtual cystoscopy. Use of virtual cystoscopy should be considered inpatients who present with hematuria or have histories of bladder carcinoma operation and are for follow-up because of its lesser complication risk and its being a less invasive, easily applied procedure without need of anesthesia. In the future, owing to the development of the CT technology and image processing technique, virtual cystoscopy may have a part in the detection of bladder cancer.

  10. Photoreduction of 99Tc Pertechnetate by Nanometer-Sized Metal Oxides: New Strategies for Formation and Sequestration of Low-Valent Technetium

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Burton-Pye, Benjamin P.; Radivojevic, Ivana; McGregor, Donna

    2011-11-23

    Technetium-99 ( 99Tc)(β - max: 293.7 keV; t 1/2: 2.1 x 10 5 years) is a byproduct of uranium-235 fission and comprises a large component of radioactive waste. Under aerobic conditions and in a neutral- basic environment, the pertechnetate anion ( 99TcO 4 -) is stable. 99TcO 4 - is very soluble, migrates easily through the environment and does not sorb well onto mineral surfaces, soils or sediments. This study moves forward a new strategy for the reduction of TcO 4 - and chemical incorporation of the reduced 99Tc into a metal oxide material. This strategy employs a single material,more » a polyoxometalate (POM), α 2-[P 2W 17O 61] 10-, that can be photoactivated in the presence of 2-propanol to transfer electrons to TcO 4 - and incorporate the reduced 99Tc covalently into the α 2 - framework to form the Tc VO species, Tc VO(α 2-P 2W 17O 61) 7-. This occurs via the formation of an intermediate species that slowly converts to Tc VO(α 2-P 2W 17O 61) 7-. EXAFS and XANES analysis and preliminary EPR analysis, suggests that the intermediate consists of a Tc(IV) α 2- species where the 99Tc is likely bound to only 2 of the 4 W-O oxygen atoms in the α 2-[P 2W 17O 61] 10- defect. This intermediate then oxidizes and converts to the 99Tc VO(α 2-P 2W 17O 61) 7- product. The reduction and incorporation of 99TcO 4- was accomplished in a ''one pot'' reaction using both sunlight and UV irradiation, and monitored as a function of time using multinuclear NMR and radio TLC. The process was further probed by the ''step-wise'' generation of reduced α 2-P 2W 17O 61 12- through bulk electrolysis followed by the addition of TcO 4 -. The reduction and incorporation of ReO 4 -, as a non-radioactive surrogate for 99Tc, does not proceed through the intermediate species, and Re VO is incorporated quickly into the α 2-[P 2W 17O 61] 10- defect. These observations are consistent with the periodic trends of 99Tc and Re. Specifically, 99Tc is more easily reduced compared to Re. In addition

  11. 78 FR 7395 - Foreign-Trade Zone 129-Bellingham, WA; Notification of Proposed Production Activity; T.C. Trading...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-02-01

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

  12. 76 FR 71966 - TC Ravenswood, LLC v. New York Independent System Operator, Inc., New York State Reliability...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-11-21

    ... DEPARTMENT OF ENERGY Federal Energy Regulatory Commission [Docket No. EL12-9-000] TC Ravenswood... Procedures, 18 CFR 385.206, TC Ravenswood, LLC (Complainant) filed a complaint against the New York... York Public Service Commission. \\1\\ TC Ravenswood, LLC, 136 FERC ] 61,213 (2011). The Complainant...

  13. Genetic Characterization of Trypanosoma cruzi DTUs in Wild Triatoma infestans from Bolivia: Predominance of TcI

    PubMed Central

    Brenière, Simone Frédérique; Aliaga, Claudia; Waleckx, Etienne; Buitrago, Rosio; Salas, Renata; Barnabé, Christian; Tibayrenc, Michel; Noireau, François

    2012-01-01

    Background The current persistence of Triatoma infestans (one of the main vectors of Chagas disease) in some domestic areas could be related to re-colonization by wild populations which are increasingly reported. However, the infection rate and the genetic characterization of the Trypanosoma cruzi strains infecting these populations are very limited. Methodology/Principal Findings Of 333 wild Triatoma infestans specimens collected from north to south of a Chagas disease endemic area in Bolivia, we characterized 234 stocks of Trypanosoma cruzi using mini-exon multiplex PCR (MMPCR) and sequencing the glucose phosphate isomerase (Gpi) gene. Of the six genetic lineages (“discrete typing units”; DTU) (TcI-VI) presently recognized in T. cruzi, TcI (99.1%) was overdominant on TcIII (0.9%) in wild Andean T. infestans, which presented a 71.7% infection rate as evaluated by microscopy. In the lowlands (Bolivian Chaco), 17 “dark morph” T. infestans were analyzed. None of them were positive for parasites after microscopic examination, although one TcI stock and one TcII stock were identified using MMPCR and sequencing. Conclusions/Significance By exploring large-scale DTUs that infect the wild populations of T. infestans, this study opens the discussion on the origin of TcI and TcV DTUs that are predominant in domestic Bolivian cycles. PMID:22685616

  14. Chondro-Protective and Antiarthritic Effects of Sulfonamido-Based Gallate-ZXHA-TC in Vitro and in Vivo.

    PubMed

    Lu, Zhenhui; Wu, Huayu; Lin, Xiao; Liu, Buming; Lin, Cuiwu; Zheng, Li; Zhao, Jinmin

    2016-06-17

    The effects of gallic acid (GA) on arthritis are limited by weak antioxidant effects and inferior biological properties of GA. We recently described a new series of synthesized GA derivatives by coupling with sulfonamides. Among these analogs, a novel compound synthesized from GA and sulfadimoxine (SDM) named ZXHA-TC exhibited the most robust anti-inflammatory potential. In this current study, the chondro-protective and antiarthritic effects of ZXHA-TC were investigated both in vitro and in vivo. In the in vitro study, ZXHA-TC exerted chondro-protective effects as evidenced by promoting cell proliferation and the maintaining of the phenotype of articular chondrocytes treated with interleukin-1-beta (IL-1β). The potential of ZXHA-TC to slow the progress of osteoarthritis (OA) was suggested by a reduction in matrix metalloproteinases (MMPs) and the up-regulation of the tissue inhibitor of metalloproteinase-1 (TIMP-1). In a rabbit anterior cruciate ligament transaction (ACLT) model of OA, ZXHA-TC exerted a protective effect on arthritis as assessed by macroscopic scores, histological, qRT-PCR, and immunohistochemical analyses. The effects of ZXHA-TC on inhibiting the production of inflammatory mediators in OA may be mediated partly by the suppression of the PI3K/AKT pathway or MAPK cascades, leading to NF-κB inactivation. Thus, this study indicates that ZXHA-TC may be developed as a potential therapeutic agent for OA.

  15. Contractor Performed Quality Control on KyTC Projects.

    DOT National Transportation Integrated Search

    2002-08-01

    This report addresses issues related to transferring the responsibility for quality control from the Kentucky Transportation Cabinet (KyTC) to construction contractors. : Several key topics related to Contractor Performed Quality Control (CPQC) are p...

  16. The Tc Trend In The Zetta Reticuli System: N Spectra - N Trends.

    NASA Astrophysics Data System (ADS)

    Adibekyan, V.; Figueira, P.; Delgado Mena, E.; Sousa, S. G.; Santos, N. C.; González Hernández; , I.; Israelian, G.

    2017-10-01

    It is suggested that the chemical abundance trend with the condensation temperature, Tc , can be a signature of rocky planet formation or accretion. Recently, a strong Tc trend was reported in the Zetta Reticuli binary system (Saffe et al., 2016), where ζ2 Ret Ret shows a deficit of refractory elements relative to its companion (ζ1 Ret). This depletion was explained by the presence of a debris disk around ζ2 Ret. Later, Adibekyan et al. (2016b) confirmed the significance of the trend, however, casted doubts on the interpretation proposed. Using three individual highest quality spectra for each star, they found that the Tc trends depend on the individual spectra (three spectra of each star were used) used in the analaysis. In the current work we re-evaluated the presence and variability of the Tc trend in this system using a larger number of individual spectra. In total, 62 spectra of ζ2 Ret and 31 spectra of ζ1 Ret was used. Our results confirm the word of caution issued by Adibekyan et al. (2016b) that nonphysical factors can be at the root of the T c trends for the cases of individual spectra.

  17. Sperwer After S/A TC. Military Aviation Requirements; An Approach to Address the New RNLA UAV Domain

    DTIC Science & Technology

    2003-09-02

    houder BVLn (t.z.t. over te dragen aan C-1Div) D-DMKLu (Airworthiness Authority RNLAF) BLS Type Certificate Holder (DM) Sagem (delegated TC Holder...1Div 1 ) Airworthiness Authority (RNLAF) TC-Houder (LE-21) Ontwerper, Producent, Sagem (JAR-21) Type certificaat (TC) Bewijzen van Luchtwaardig- heid

  18. The differentiation and plasticity of Tc17 cells are regulated by CTLA-4-mediated effects on STATs.

    PubMed

    Arra, Aditya; Lingel, Holger; Kuropka, Benno; Pick, Jonas; Schnoeder, Tina; Fischer, Thomas; Freund, Christian; Pierau, Mandy; Brunner-Weinzierl, Monika C

    2017-01-01

    As the blockade of inhibitory surface-molecules such as CTLA-4 on T cells has led to recent advances in antitumor immune therapy, there is great interest in identifying novel mechanisms of action of CD8 + T cells to evoke effective cytotoxic antitumor responses. Using in vitro and in vivo models, we investigated the molecular pathways underlying the CTLA-4-mediated differentiation of IL-17-producing CD8 + T cells (Tc17 cells) that strongly impairs cytotoxicity. Our studies demonstrate that Tc17 cells lacking CTLA-4 signaling have limited production of STAT3-target gene products such as IL-17, IL-21, IL-23R and RORγt. Upon re-stimulation with IL-12, these cells display fast downregulation of Tc17 hallmarks and acquire Tc1 characteristics such as IFNγ and TNF-α co-expression, which is known to correlate with tumor control. Indeed, upon adoptive transfer, these cells were highly efficient in the antigen-specific rejection of established OVA-expressing B16 melanoma in vivo . Mechanistically, in primary and re-stimulated Tc17 cells, STAT3 binding to the IL-17 promoter was strongly augmented by CTLA-4, associated with less binding of STAT5 and reduced relative activation of STAT1 which is known to block STAT3 activity. Inhibiting CTLA-4-induced STAT3 activity reverses enhancement of signature Tc17 gene products, rendering Tc17 cells susceptible to conversion to Tc1-like cells with enhanced cytotoxic potential. Thus, CTLA-4 critically shapes the characteristics of Tc17 cells by regulating relative STAT3 activation, which provides new perspectives to enhance cytotoxicity of antitumor responses.

  19. Technetium-99m galactosyl-neoglycoalbumin (Tc-NGA) liver imaging: Application in liver transplantation

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Woodle, E.S.; Ward, R.E.; Vera, D.R.

    1985-05-01

    Tc-NGA is a new liver imaging agent which binds to hepatic binding protein (HBP), a hepatocyte-specific membrane receptor. The purpose of the present study was to evaluate the potential role of Tc-NGA imaging in liver transplantation. The molar Tc-NGA dose was standardized according to patient weight (0.7 nmole/kg). After a 30 minute dynamic imaging study (5 mCi, IV), kinetic analysis of time activity data (heart, liver), provided values for receptor concentration, (HBP), and hepatic blood flow, Q. Eleven Tc-NGA imaging studies were performed in transplant candidates and 22 studies were performed in seven transplant recipients. Preservation damage was manifested bymore » diffuse patchiness in tracer distribution which resolved during the following two weeks. Histologically proven, localized hepatic infarcts were demonstrated in three recipients. Lobar infarction was demonstrated in one recipient. Hepatic regeneration was later demonstrated in this patient after hepatic lobectomy. Hepatic blood flow was markedly decreased in the early postoperative period, but improved with time. Increased (HBP) was demonstrated with regeneration. Markedly decreased (HBP) and Q were obtained in several candidates who died awaiting transplantation. These studies indicate that TC-NGA liver imaging provides a valuable new means for: (1) evaluation of preservation damage, (2) early demonstration of hepatic infarction, (3) evaluation of hepatic rejection, and (4) selection of patients for hepatic transplantation.« less

  20. Sentinel lymph node accumulation of Lymphoseek and Tc-99m-sulfur colloid using a “2-day” protocol☆

    PubMed Central

    Wallace, Anne M.; Hoh, Carl K.; Limmer, Karl K.; Darrah, Denise D.; Schulteis, Gery; Vera, David R.

    2014-01-01

    Lymphoseek is a receptor-binding radiopharmaceutical specifically designed for sentinel lymph node (SLN) mapping. We conducted a clinical trial which measured the injection site clearance and sentinel lymph node accumulation after a single intradermal injection of Lymphoseek or unfiltered [99mTc]sulfur colloid (TcSC) using a “2-day” protocol for SLN mapping of breast cancer. Eleven patients with breast cancer participated in this study. Five patients received an intradermal administration of 1.0 nmol of 99mTc-labeled Lymphoseek; SLN mapping was performed on four subjects within 19 to 27 h. Six subjects received an intradermal administration of TcSC; SLN mapping was performed on five subjects within 18 to 26 h. Lymphoseek exhibited a significantly (P<.001) faster injection site clearance than TcSC. The mean Lymphoseek clearance half-time was 2.18±1.09 h compared to 57.4±92.8 h for TcSC. The mean sentinel lymph node uptake of Lymphoseek (1.5±1.7%) and TcSC (3.5±3.1%) was statistically equivalent (P=.213). When an intradermal injection is employed, Lymphoseek demonstrated faster injection site clearance than unfiltered [99mTc]sulfur colloid and persistent SLN accumulation for at least 24 h. PMID:19647175

  1. Aspergilosis cervical con diseminación al sistema nervioso central. Presentación de un caso y revisión de bibliografía

    PubMed Central

    Vergara, Guillermo Enrique; Roura, Natalia; del Castillo, Marcelo; Mora, Andrea; Alcorta, Santiago Condomi; Mormandi, Rubén; Cervio, Andrés; Salvat, Jorge

    2015-01-01

    Introducción: la Aspergilosis Invasiva (AI) del Sistema Nervioso Central (SNC) es infrecuente y ocurre generalmente en pacientes inmunocomprometidos. Puede presentarse con cuadros de meningitis, aneurismas micóticos, infartos o abscesos. Es una infección con pronóstico reservado y puede afectar el SNC de forma primaria o secundaria a partir de un foco que se disemina por vía hematógena. Presentamos el caso de un paciente con AI con invasión primaria a nivel óseo y diseminación posterior al cerebro. Caso clínico: Paciente masculino de 25 años con diagnóstico de leucemia linfática aguda en tratamiento quimioterápico que presentó neumonitis por metotrexate por lo que inicia tratamiento con corticoides. Posteriormente agregó cervicalgia y con el diagnóstico de osteomielitis cervical se realiza punción bajo tomografía computada (TC) sin aislarse gérmenes. Se colocó Halo Vest e inició tratamiento antibiótico empírico. Posteriormente presentó afasia de expresión secundaria a lesión frontal izquierda. Se realizó evacuación de absceso cerebral aislando A. fumigatus. El tratamiento antibiótico específico posterior permitió una buena respuesta clínica y radiológica. Conclusión: La presencia de lesiones en el SNC de pacientes inmunocomprometidos debe incluir a las micosis como diagnóstico diferencial. La evacuación quirúrgica permite llegar rápidamente al diagnóstico mejorando la respuesta posterior al tratamiento antibiótico. Para evaluar la respuesta terapéutica y posibles recaídas se debe realizar un seguimiento periódico clínico radiológico. Palabras clave: Aspergilosis cerebral; Aspergilosis cervical; Aspergilosis invasiva; Voriconazol. PMID:26600985

  2. Epitaxial effects in thin films of high-Tc cuprates with the K2NiF4 structure

    NASA Astrophysics Data System (ADS)

    Naito, Michio; Sato, Hisashi; Tsukada, Akio; Yamamoto, Hideki

    2018-03-01

    La2-xSrxCuO4 (LSCO) and La2-xBaxCuO4 (LBCO) have been recognized as the archetype materials of "hole-doped" high-Tc superconductors. Their crystal structures are relatively simple with a small number of constituent cation elements. In addition, the doping level can be varied by the chemical substitution over a wide range enough to obtain the full spectrum of doping-dependent electronic and magnetic properties. These attractive features have dedicated many researchers to thin-film growth of LSCO and LBCO. The critical temperature (Tc) of LSCO and LBCO is sensitive to strain as manifested by a positive pressure coefficient of Tc in bulk samples. In general, films are strained if they are grown on lattice-mismatched substrates (epitaxial strain). Early attempts (before 1997) at the growth of LSCO and LBCO films resulted in depressed Tc below 30 K as they were grown on a commonly used SrTiO3 substrate (in-plane lattice parameter asub = 3.905 Å): the in-plane lattice parameters of LSCO and LBCO are ≤3.80 Å, and hence tensile epitaxial strain is introduced. The situation was changed by the use of LaSrAlO4 substrates with a slightly shorter in-plane lattice constant (asub = 3.756 Å). On LaSrAlO4 substrates, the Tc reaches 45 K in La1.85Sr0.15CuO4, 47 K in La1.85Ba0.15CuO4, and 56 K in ozone-oxidized La2CuO4+δ films, substantially higher than the Tc's of the bulk compounds. The Tc increase in La1.85Sr0.15CuO4 films on LaSrAlO4 and decrease on SrTiO3 are semi-quantitatively in accord with the phenomenological estimations based on the anisotropic strain coefficients of Tc (dTc/dεi). In this review article, we describe the growth and properties of films of cuprates having the K2NiF4 structure, mainly focusing on the increase/decrease of Tc by epitaxial strain and quasi-stable phase formation by epitaxial stabilization. We further extract the structural and/or physical parameters controlling Tc toward microscopic understanding of the variation of Tc by epitaxial strain.

  3. Initial Evaluation of (99m)Tc(CO)3(ASMA) as a Renal Tracer in Healthy Human Volunteers.

    PubMed

    Lipowska, Malgorzata; Klenc, Jeffrey; Folks, Russell D; Taylor, Andrew T

    2014-09-01

    Preclinical studies in rats showed that two of (99m)Tc(CO)3(ASMA) isomers (rac- and L-ASMA) had pharmacokinetic properties equivalent to that of (131)I-OIH, the radiopharmaceutical standard for the measurement of effective renal plasma flow. The aim of this study was to evaluate the pharmacokinetics of (99m)Tc(CO)3(ASMA) isomers in healthy human subjects. Three ASMA ligands (rac-, L- and D-ASMA) were labeled with (99m)Tc(CO)3 using an IsoLink kit (Covidien), and each formed (99m)Tc(CO)3(ASMA) tracer was co-injected with (131)I-OIH into healthy human subjects followed by sequential imaging, plasma clearance measurements and timed urine collection. Plasma protein binding, red cell uptake and percent injected dose in the urine were determined. Urine from each group of volunteers was analyzed for metabolites by HPLC. Image quality was excellent with all three agents. Each (99m)Tc(CO)3(ASMA) preparation was excreted unchanged in the urine. The plasma clearance ratio ((99m)Tc(CO)3(ASMA)/(131)I-OIH) was 81 ± 3 % for D-ASMA compared to only 20 ± 4 % for L-ASMA and 37 ± 7 % for rac-ASMA; the 81 % clearance ratio for D-ASMA isomer is still ∼ 30 % higher than the (99m)Tc-MAG3/(131)I-OIH clearance ratio (∼50-60 %). Red cell uptake was similar for all three tracers (6-9 %), and all tracers had a relatively rapid renal excretion; at 3 h, the (99m)Tc(CO)3(ASMA)/(131)I-OIH urine ratio was 100 ± 3 % for D-ASMA, 80 ± 2 % for L-ASMA and 88 ± 1 % for rac-ASMA. The renal excretion characteristics of (99m)Tc(CO)3(D-ASMA) in humans are superior to those of the other two (99m)Tc(CO)3(ASMA) isomers studied, but are still inferior to (131)I-OIH, even though there was no difference in the clearance of two of (99m)Tc(CO)3(ASMA) isomers and (131)I-OIH in rats. The work described here demonstrates the sensitivity in in vivo biological behavior of (99m)Tc(CO)3(ASMA) isomers to their subtle structural differences.

  4. Lung function declines in patients with pulmonary sarcoidosis and increased respiratory epithelial permeability to sup 99m Tc-DTPA

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Chinet, T.; Dusser, D.; Labrune, S.

    1990-02-01

    Respiratory epithelial clearance of {sup 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 {sup 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 stablemore » 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.« less

  5. Migrating data from TcSE to DOORS : an evaluation of the T-Plan Integrator software application.

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Post, Debra S.; Manzanares, David A.; Taylor, Jeffrey L.

    2011-02-01

    This report describes our evaluation of the T-Plan Integrator software application as it was used to transfer a real data set from the Teamcenter for Systems Engineering (TcSE) software application to the DOORS software application. The T-Plan Integrator was evaluated to determine if it would meet the needs of Sandia National Laboratories to migrate our existing data sets from TcSE to DOORS. This report presents the struggles of migrating data and focuses on how the Integrator can be used to map a data set and its data architecture from TcSE to DOORS. Finally, this report describes how the bulk ofmore » the migration can take place using the Integrator; however, about 20-30% of the data would need to be transferred from TcSE to DOORS manually. This report does not evaluate the transfer of data from DOORS to TcSE.« less

  6. Role of multidetector computed tomography in evaluating incidentally detected breast lesions.

    PubMed

    Moschetta, Marco; Scardapane, Arnaldo; Lorusso, Valentina; Rella, Leonarda; Telegrafo, Michele; Serio, Gabriella; Angelelli, Giuseppe; Ianora, Amato Antonio Stabile

    2015-01-01

    Computed tomography (CT) does not represent the primary method for the evaluation of breast lesions; however, it can detect breast abnormalities, even when performed for other reasons related to thoracic structures. The aim of this study is to evaluate the potential benefits of 320-row multidetector CT (MDCT) in evaluating and differentiating incidentally detected breast lesions by using vessel probe and 3D analysis software with net enhancement value. Sixty-two breast lesions in 46 patients who underwent 320-row chest CT examination were retrospectively evaluated. CT scans were assessed searching for the presence, location, number, morphological features, and density of breast nodules. Net enhancement was calculated by subtracting precontrast density from the density obtained by postcontrast values. The sensitivity, specificity, positive predictive value (PPV), negative predictive value (NPV), and diagnostic accuracy of CT were calculated for morphological features and net enhancement. Thirty of 62 lesions were found to be malignant at histological examination and 32 were found to be benign. When morphological features were considered, the sensitivity, specificity, accuracy, PPV, and NPV of CT were 87%, 100%, 88%, 100%, and 50%, respectively. Based on net enhancement, CT reached a sensitivity, specificity, accuracy, PPV, and NPV of 100%, 94%, 97%, 94%, and 100%, respectively. MDCT allows to recognize and characterize breast lesions based on morphological features. Net enhancement can be proposed as an additional accurate feature of CT.

  7. Quantitative analysis of relationships between irradiation parameters and the reproducibility of cyclotron-produced (99m)Tc yields.

    PubMed

    Tanguay, J; Hou, X; Buckley, K; Schaffer, P; Bénard, F; Ruth, T J; Celler, A

    2015-05-21

    Cyclotron production of (99m)Tc through the (100)Mo(p,2n) (99m)Tc reaction channel is actively being investigated as an alternative to reactor-based (99)Mo generation by nuclear fission of (235)U. An exciting aspect of this approach is that it can be implemented using currently-existing cyclotron infrastructure to supplement, or potentially replace, conventional (99m)Tc production methods that are based on aging and increasingly unreliable nuclear reactors. Successful implementation will require consistent production of large quantities of high-radionuclidic-purity (99m)Tc. However, variations in proton beam currents and the thickness and isotopic composition of enriched (100)Mo targets, in addition to other irradiation parameters, may degrade reproducibility of both radionuclidic purity and absolute (99m)Tc yields. The purpose of this article is to present a method for quantifying relationships between random variations in production parameters, including (100)Mo target thicknesses and proton beam currents, and reproducibility of absolute (99m)Tc yields (defined as the end of bombardment (EOB) (99m)Tc activity). Using the concepts of linear error propagation and the theory of stochastic point processes, we derive a mathematical expression that quantifies the influence of variations in various irradiation parameters on yield reproducibility, quantified in terms of the coefficient of variation of the EOB (99m)Tc activity. The utility of the developed formalism is demonstrated with an example. We show that achieving less than 20% variability in (99m)Tc yields will require highly-reproducible target thicknesses and proton currents. These results are related to the service rate which is defined as the percentage of (99m)Tc production runs that meet the minimum daily requirement of one (or many) nuclear medicine departments. For example, we show that achieving service rates of 84.0%, 97.5% and 99.9% with 20% variations in target thicknesses requires producing on average

  8. Quantitative analysis of relationships between irradiation parameters and the reproducibility of cyclotron-produced 99mTc yields

    NASA Astrophysics Data System (ADS)

    Tanguay, J.; Hou, X.; Buckley, K.; Schaffer, P.; Bénard, F.; Ruth, T. J.; Celler, A.

    2015-05-01

    Cyclotron production of 99mTc through the 100Mo(p,2n) 99mTc reaction channel is actively being investigated as an alternative to reactor-based 99Mo generation by nuclear fission of 235U. An exciting aspect of this approach is that it can be implemented using currently-existing cyclotron infrastructure to supplement, or potentially replace, conventional 99mTc production methods that are based on aging and increasingly unreliable nuclear reactors. Successful implementation will require consistent production of large quantities of high-radionuclidic-purity 99mTc. However, variations in proton beam currents and the thickness and isotopic composition of enriched 100Mo targets, in addition to other irradiation parameters, may degrade reproducibility of both radionuclidic purity and absolute 99mTc yields. The purpose of this article is to present a method for quantifying relationships between random variations in production parameters, including 100Mo target thicknesses and proton beam currents, and reproducibility of absolute 99mTc yields (defined as the end of bombardment (EOB) 99mTc activity). Using the concepts of linear error propagation and the theory of stochastic point processes, we derive a mathematical expression that quantifies the influence of variations in various irradiation parameters on yield reproducibility, quantified in terms of the coefficient of variation of the EOB 99mTc activity. The utility of the developed formalism is demonstrated with an example. We show that achieving less than 20% variability in 99mTc yields will require highly-reproducible target thicknesses and proton currents. These results are related to the service rate which is defined as the percentage of 99mTc production runs that meet the minimum daily requirement of one (or many) nuclear medicine departments. For example, we show that achieving service rates of 84.0%, 97.5% and 99.9% with 20% variations in target thicknesses requires producing on average 1.2, 1.5 and 1.9 times the

  9. Experimental partitioning of Tc, Mo, Ru, and Re between solid and liquid during crystallization in Fe-Ni-S 1

    NASA Astrophysics Data System (ADS)

    Lazar, C.; Walker, D.; Walker, R. J.

    2004-02-01

    Technetium isotopes 97Tc, 98Tc and 99Tc decay to 97Mo, 98Ru and 99Ru, with half-lives of 2.6 My, 4.1 My, and 0.21 My respectively. If there were early solar system processes that resulted in significant fractionation of Tc from the daughter elements, decay of extant Tc could have led to the creation of Mo and Ru isotopic heterogeneities. To assess the potential of metallic core crystallization to fractionate these elements, we examine the partitioning behavior of Tc relative to Re, Mo and Ru in the Fe-Ni-S system between solid metal and liquid metal alloy. The experimental evidence shows that Tc behaves more like the modestly compatible siderophile element Ru than the more highly compatible siderophile element Re, and that Tc is substantially more compatible than Mo. We also demonstrate a pressure effect in the partitioning of Mo during the crystallization of Fe-Ni-S melts. For a sulfur concentration in the liquid fraction of the core of 10 wt% (16.3 at%), the Jones and Malvin (1990) parameter is -ln(1-2 × 1.09 × 0.163) ≅ 0.44, which yields: D(Re) ≅ 4.1; D(Ru) ≅ 2.3; D(Tc) ≅ 1.7; D(Mo) Lo-P ≅ 1.0;.and D(Mo) Hi-P ≅ 0.5. Our results suggest that detectable Tc-induced isotopic anomalies (≥0.1 ɛ unit) in Ru and Mo could only be produced by unrealistically extreme degrees of crystallization of metal during asteroidal core fractionation, regardless of the time scales and initial Tc abundances involved.

  10. 99mTc-CXCL8 SPECT to Monitor Disease Activity in Inflammatory Bowel Disease.

    PubMed

    Aarntzen, Erik H J G; Hermsen, Rick; Drenth, Joost P H; Boerman, Otto C; Oyen, Wim J G

    2016-03-01

    Inflammatory bowel diseases (IBDs) are defined as chronic relapsing immune-mediated disorders of the gastrointestinal tract. IBD exacerbations are characterized by recruitment of mainly CXCL8 receptor-expressing activated neutrophils into the intestinal wall, leading to severe damage. Considering its chronic relapsing character, accurate and timely diagnosis of an exacerbation is pivotal for early adaptation of the treatment and reduction of the disease burden. However, endoscopic evaluation is invasive and associated with an increased risk of perforation. We previously developed a (99m)Tc-labeled CXCL8 preparation in preclinical models including colitis and clinical studies. In this study, we investigate the accuracy of (99m)Tc-CXCL8 SPECT to detect and localize disease activity in a prospective series of patients with IBD. Thirty patients (15 Crohns disease, 15 ulcerative colitis) participated, and 92 segmental pairs of histology and (99m)Tc-CXCL8 scans were studied. Imaging was performed after injection of 400 MBq of (99m)Tc-CXCL8. Planar and SPECT images of the abdomen were acquired at 30 min and 4 h after the injection. The overall sensitivity and specificity on a per-patient basis for the detection of active disease were 95% and 44% for (99m)Tc-CXCL8 scan and 71% and 70% for endoscopy. The degree of (99m)Tc-CXCL8 accumulation correlated to the degree of neutrophilic influx in affected mucosa. Sensitivity and specificity on a per-segment basis, calculated from the 92 segmental pairs, were 82% and 72%, negative predictive value was 81%, and overall positive predictive value was 74%. Specificity could be increased at the expense of sensitivity using different cutoffs. In 74 segmental pairs, overall sensitivity and specificity for endoscopy were 74% and 85%, positive predictive value was 81%, and negative predictive value was 79%. (99m)Tc-CXCL8 SPECT provides a novel imaging technique to target neutrophil recruitment to the intestinal wall, especially in moderate

  11. Clinical translation of a PSMA inhibitor for 99mTc-based SPECT.

    PubMed

    Ferro-Flores, Guillermina; Luna-Gutiérrez, Myrna; Ocampo-García, Blanca; Santos-Cuevas, Clara; Azorín-Vega, Erika; Jiménez-Mancilla, Nallely; Orocio-Rodríguez, Emmanuel; Davanzo, Jenny; García-Pérez, Francisco O

    2017-05-01

    Prostate-specific membrane antigen (PSMA) is highly over-expressed in advanced prostate cancers. 68 Ga-labeled PSMA inhibitors (iPSMA) are currently used for prostate cancer detection by PET imaging. The availability of simple, efficient and reproducible radiolabeling procedures is essential for developing new SPECT radiopharmaceuticals for clinical translation. The aim of this research was to prepare 99m Tc-EDDA/HYNIC-Lys(Nal)-Urea-Glu ( 99m Tc-EDDA/HYNIC-iPSMA) obtained from lyophilized kit formulations and evaluate the in vitro and in vivo radiopharmaceutical binding to prostate cancer cells over-expressing PSMA, as well as the 99m Tc-EDDA/HYNIC-iPSMA normal biodistribution in humans and the preliminary uptake in patients with prostate cancer. 99m Tc labeling was performed by adding sodium pertechnetate solution and a 0.2M phosphate buffer (pH 7.0) to a lyophilized formulation containing HYNIC-iPSMA, EDDA, tricine, mannitol and stannous chloride. The radiochemical purity was evaluated by reversed-phase HPLC and ITLC-SG analyses. Stability studies in human serum were performed by size-exclusion HPLC. In vitro cell uptake was tested using prostate cancer cells (LNCaP) with blocked and non-blocked receptors. Biodistribution and tumor uptake were determined in LNCaP tumor-bearing nude mice with blocked and non-blocked receptors, and images were obtained using a micro-SPECT/CT. Whole-body images from three healthy men and two patients with histologically-confirmed prostate cancer (one of them with a previous 68 Ga-PSMA-617scan) were acquired at 1h and 3h after 99m Tc-EDDA/HYNIC-iPSMA administration with radiochemical purities of >98%. In vitro and in vivo studies showed high radiopharmaceutical stability in human serum, specific recognition for PSMA, high tumor uptake (10.22±2.96% ID/g at 1h) with rapid blood clearance and mainly kidney elimination. Preliminary images in patients demonstrated the ability of 99m Tc-EDDA/HYNIC-iPSMA to detect tumors and metastases of

  12. Circulation of Tc Ia discrete type unit Trypanosoma cruzi in Yucatan Mexico.

    PubMed

    Monteón, Victor; Triana-Chávez, Omar; Mejía-Jaramillo, Ana; Pennignton, Pamela; Ramos-Ligonio, Ángel; Acosta, Karla; Lopez, Ruth

    2016-06-01

    The etiologic agent Trypanosoma cruzi (Tc) has been grouped into six discrete type units (DTU I-VI); within DTU-I exists four subgroups defined Ia-Id. In Colombia, the genotype Ia is associated with human infection and domiciliated Rhodnius vector. In the Yucatan Peninsula of Mexico, the main vector involved in T. cruzi transmission is Triatoma dimidiata predominantly via sylvatic and peridomiciliated cycles. In this study, multiple sequence analysis of mini-exon intergenic regions of T. cruzi isolates obtained from T. dimidiata in the Yucatan Peninsula of Mexico revealed they belonged to Tc Ia DTU along with two additional Mexican strains located 1,570 km away from Yucatan. In conclusion Tc Ia circulates in the Yucatan peninsula in T. dimidiata vector and likewise in the northwest region of Mexico.

  13. Early detection of rheumatoid arthritis in rats and humans with 99mTc-3PRGD2 scintigraphy: imaging synovial neoangiogenesis

    PubMed Central

    Wang, Xiangcheng; Zhao, Zhenfang; Wang, Tao; Wang, Xuemei; Li, Xiao-Feng

    2017-01-01

    Objectives: To validate 99mTc-labeled arginylglycylaspartic acid (99mTc-3PRGD2) scintigraphy as a means to image synovial neoangiogenesis in joints afflicted by rheumatoid arthritis and to investigate its potential in the early detection and management of rheumatoid arthritis. Methods: Rheumatoid arthritis and osteoarthritis were generated in Sprague Dawley rats by type II collagen immunization and papain injection, respectively. Rats were imaged with 99mTc-3PRGD2 and 99mTc- methyl diphosphonate (99mTc MDP). X-ray images were also obtained and assessed by a radiologist. Immunohistochemistry of αvβ3 and CD31confirmed the onset of synovial neoangiogenesis. The effect of bevacizumab on rheumatoid arthritis was followed with 99mTc-3PRGD2 scintigraphy. A patient with rheumatoid arthritis and a healthy volunteer were scanned with 99mTc-3PRGD2. Results: Two weeks after immunization, a significant increase in 99mTc-3PRGD2 was observed in the joints of the rheumatoid arthritis model though uptake in osteoarthritis model and untreated controls was low. 99mTc-MDP whole body scans failed to distinguish early rheumatoid arthritis joints from healthy controls. The expression of αvβ3 and CD31was significantly higher in the joints of rheumatoid arthritis rats compared to normal controls. In serial 99mTc-3PRGD2 scintigraphy studies, 99mTc-3PRGD2 uptake increased in parallel with disease progression. Bevacizumab anti-angiogenetic therapy both improved the symptoms of the rheumatoid arthritis rats and significantly decreased 99mTc-3PRGD2 uptake. Significantly higher 99mTc-3PRGD2 accumulation was also observed in rheumatoid arthritis joints in the patient. Conclusions: Our findings indicate that 99mTc-3PRGD2 scintigraphy could detect early rheumatoid arthritis by imaging the associated synovial neoangiogenesis, and may be useful in disease management. PMID:27992368

  14. Synthesis and biological assessment of folate-accepted developer (99m)Tc-DTPA-folate-polymer.

    PubMed

    Chen, Fei; Shao, Kejing; Zhu, Bao; Jiang, Mengjun

    2016-05-15

    A novel cancer-targetable folate-poly(2-hydroxyethyl methacrylate) (PFDH) copolymer containing DTPA segment was prepared by conventional chemical synthesis and labeled with (99m)Tc subsequently. The (99m)Tc-labled PFDH could be produced easily with high radiochemical yield of 91% and radiochemical purity of 95%. The LogP octanol-water value for the (99m)Tc-labled PFDH was -2.19 and the radiotracer was stable in phosphate-buffered saline and human serum for 2h (>95% in PBS or ∼90% in human serum). To investigate (99m)Tc-labled PFDH tumor targeting, the in vitro and in vivo stability, cell uptake, in vivo biodistribution, and SPECT imaging were evaluated, respectively. These preliminary results strongly suggest that the novel folate conjugated dendrimer maybe developed to be potential for delivery of therapeutic radionuclides. Copyright © 2016 Elsevier Ltd. All rights reserved.

  15. Streptozotocin (STZ) and schistosomiasis mansoni change the biodistribution of radiopharmaceutical sodium (99m)Tc-pertechnetate in mice.

    PubMed

    Góes, Vanessa Coelho; Neves, Renata Heisler; Arnóbio, Adriano; Bernardo-Filho, Mario; Machado-Silva, José Roberto

    2016-09-01

    Technetium-99m ((99m)Tc) is a radionuclide commonly used in nuclear medicine to obtain (99m)Tc-radiopharmaceuticals, which can be used to evaluate either physiological processes or changes related to diseases. It is also used in some experimental studies. Streptozotocin (STZ) administration to rodents causes lesions in very early stages and induces severe and permanent diabetes. Most morbidity of schistosomiasis mansoni is attributed to a granulomatous inflammatory response and associated liver fibrosis. This study was designed to investigate whether STZ administration and schistosomiasis modify the biodistribution of the radiopharmaceutical sodium (99m)Tc-pertechnetate. Adult female mice were infected by exposure to 100Schistosoma mansoni cercariae (BH strain, Belo Horizonte, Brazil) and euthanized after nine weeks. STZ was administered by a single intraperitoneal injection of 100mg/kg body weight, 3 or 15days before euthanasia. Each animal received 100μl of sodium (Na) (99m)Tc-pertechnetate ((99m)TcO4(-)) (740kBq). The animals were divided into four groups: A, uninfected; B, infected; C, uninfected + STZ; and D, infected + STZ. Blood, brain, thyroid, heart, lungs, liver, spleen, pancreas and kidneys were removed. The radioactivity was counted and the percentage of the injected dose of Na(99m)TcO4 per gram of the organ (% ID/g) was determined. Three days after the STZ injection, there was a decrease of Na(99m)TcO4 uptake by the liver, lungs, pancreas and kidneys (p<0.05) in group D when compared with group A. After 15days, the decrease of Na(99m)TcO4 uptake occurred also in the brain, thyroid, heart, spleen and blood (p<0.05) in group D. We demonstrated modifications on the biodistribution of Na(99m)TcO4 due to STZ administration and schistosomiasis, possibly due to physiological alterations in some organs. The biodistribution of radiopharmaceutical Na(99m)TcO4 should be carefully evaluated in subjects with diabetes and/or schistosomiasis infection. Copyright

  16. Molybdenum target specifications for cyclotron production of 99mTc based on patient dose estimates.

    PubMed

    Hou, X; Tanguay, J; Buckley, K; Schaffer, P; Bénard, F; Ruth, T J; Celler, A

    2016-01-21

    In response to the recognized fragility of reactor-produced (99)Mo supply, direct production of (99m)Tc via (100)Mo(p,2n)(99m)Tc reaction using medical cyclotrons has been investigated. However, due to the existence of other Molybdenum (Mo) isotopes in the target, in parallel with (99m)Tc, other technetium (Tc) radioactive isotopes (impurities) will be produced. They will be incorporated into the labeled radiopharmaceuticals and result in increased patient dose. The isotopic composition of the target and beam energy are main factors that determine production of impurities, thus also dose increases. Therefore, they both must be considered when selecting targets for clinical (99m)Tc production. Although for any given Mo target, the patient dose can be predicted based on complicated calculations of production yields for each Tc radioisotope, it would be very difficult to reverse these calculations to specify target composition based on dosimetry considerations. In this article, a relationship between patient dosimetry and Mo target composition is studied. A simple and easy algorithm for dose estimation, based solely on the knowledge of target composition and beam energy, is described. Using this algorithm, the patient dose increase due to every Mo isotope that could be present in the target is estimated. Most importantly, a technique to determine Mo target composition thresholds that would meet any given dosimetry requirement is proposed.

  17. Molybdenum target specifications for cyclotron production of 99mTc based on patient dose estimates

    NASA Astrophysics Data System (ADS)

    Hou, X.; Tanguay, J.; Buckley, K.; Schaffer, P.; Bénard, F.; Ruth, T. J.; Celler, A.

    2016-01-01

    In response to the recognized fragility of reactor-produced 99Mo supply, direct production of 99mTc via 100Mo(p,2n)99mTc reaction using medical cyclotrons has been investigated. However, due to the existence of other Molybdenum (Mo) isotopes in the target, in parallel with 99mTc, other technetium (Tc) radioactive isotopes (impurities) will be produced. They will be incorporated into the labeled radiopharmaceuticals and result in increased patient dose. The isotopic composition of the target and beam energy are main factors that determine production of impurities, thus also dose increases. Therefore, they both must be considered when selecting targets for clinical 99mTc production. Although for any given Mo target, the patient dose can be predicted based on complicated calculations of production yields for each Tc radioisotope, it would be very difficult to reverse these calculations to specify target composition based on dosimetry considerations. In this article, a relationship between patient dosimetry and Mo target composition is studied. A simple and easy algorithm for dose estimation, based solely on the knowledge of target composition and beam energy, is described. Using this algorithm, the patient dose increase due to every Mo isotope that could be present in the target is estimated. Most importantly, a technique to determine Mo target composition thresholds that would meet any given dosimetry requirement is proposed.

  18. 99mTc-stannous colloid white cell scintigraphy in childhood inflammatory bowel disease.

    PubMed

    Peacock, Kenneth; Porn, Ute; Howman-Giles, Robert; O'Loughlin, Edward; Uren, Roger; Gaskin, Kevin; Dorney, Stuart; Kamath, Ramanand

    2004-02-01

    99mTc-Labeled white cell scintigraphy (WCS) has been used for the investigation of inflammatory bowel disease (IBD) in adults, but data on children are limited. The most common agent used is (99m) Tc-hexamethylpropyleneamine oxime (HMPAO); however, this agent has limitations. In a retrospective study, we assessed the use of (99m)Tc-stannous colloid WCS for the initial evaluation of children with suspected IBD. Diagnostic, endoscopic, and contrast radiography results were retrospectively collected from the medical records. Two experienced nuclear physicians unaware of the patient data interpreted the WCS results, with agreement reached by consensus. Statistical analysis was performed on the ability of WCS to detect active disease and localize it topographically and on a comparison of diagnostic methods, using a combination of clinical features and endoscopy as the reference standard. Between 1996 and 1999, 64 patients (35 male and 29 female; mean age, 12.5 y; age range, 2-19 y) had WCS performed, with IBD subsequently diagnosed in 34 patients. (99m)Tc-Stannous colloid WCS had an 88% sensitivity, 90% specificity, and 8.8 likelihood ratio for initial investigation of IBD. Agreement was poor for topographic localization of disease. Small-bowel series had a 75% sensitivity, 50% specificity, and 1.5 likelihood ratio for detecting endoscopic disease of the terminal ileum and proximal colon. Our results confirm that WCS is a useful imaging technique for the initial evaluation of patients with suspected IBD. (99m)Tc-Stannous colloid had results at least comparable to those of other WCS agents, and in children, (99m)Tc-stannous colloid WCS should be preferred in view of lower cost, shorter preparation time, and the smaller blood volumes required.

  19. Design and evaluation of new Tc-99m-labeled lactam bridge-cyclized alpha-MSH peptides for melanoma imaging.

    PubMed

    Guo, Haixun; Gallazzi, Fabio; Miao, Yubin

    2013-04-01

    The purpose of this study was to examine the melanoma targeting and imaging properties of new (99m)Tc-labeled lactam bridge-cyclized alpha-melanocyte stimulating hormone (α-MSH) peptides using bifunctional chelating agents. MAG3-GGNle-CycMSH(hex), AcCG3-GGNle-CycMSH(hex), and HYNIC-GGNle-CycMSH(hex) peptides were synthesized, and their melanocortin-1 (MC1) receptor binding affinities were determined in B16/F1 melanoma cells. The biodistribution of (99m)Tc-MAG3-GGNle-CycMSH(hex), (99m)Tc-AcCG3-GGNle-CycMSH(hex), (99m)Tc(CO)3-HYNIC-GGNle-CycMSH(hex), and (99m)Tc(EDDA)-HYNIC-GGNle-CycMSH(hex) were determined in B16/F1 melanoma-bearing C57 mice at 2 h postinjection to select a lead peptide for further evaluation. The melanoma targeting and imaging properties of (99m)Tc(EDDA)-HYNIC-GGNle-CycMSH(hex) were further examined because of its high melanoma uptake and fast urinary clearance. The IC50 values of MAG3-GGNle-CycMSH(hex), AcCG3-GGNle-CycMSH(hex), and HYNIC-GGNle-CycMSH(hex) were 1.0 ± 0.05, 1.2 ± 0.19, and 0.6 ± 0.04 nM in B16/F1 melanoma cells, respectively. Among these four (99m)Tc-peptides, (99m)Tc(EDDA)-HYNIC-GGNle-CycMSH(hex) exhibited the highest melanoma uptake (14.14 ± 4.90% ID/g) and fastest urinary clearance (91.26 ± 1.96% ID) at 2 h postinjection. (99m)Tc(EDDA)-HYNIC-GGNle-CycMSH(hex) showed high tumor to normal organ uptake ratios except for the kidneys. The tumor/kidney uptake ratios of (99m)Tc(EDDA)-HYNIC-GGNle-CycMSH(hex) were 2.50 and 3.55 at 4 and 24 h postinjection. The melanoma lesions were clearly visualized by SPECT/CT using (99m)Tc(EDDA)-HYNIC-GGNle-CycMSH(hex) as an imaging probe at 2 h postinjection. Overall, high melanoma uptake coupled with fast urinary clearance of (99m)Tc(EDDA)-HYNIC-GGNle-CycMSH(hex) highlighted its potential for metastatic melanoma detection in the future.

  20. Design and Evaluation of New Tc-99m-Labeled Lactam Bridge-Cyclized Alpha-MSH Peptides for Melanoma Imaging

    PubMed Central

    Guo, Haixun; Gallazzi, Fabio; Miao, Yubin

    2013-01-01

    The purpose of this study was to examine the melanoma targeting and imaging properties of new 99mTc-labeled lactam bridge-cyclized alpha-melanocyte stimulating hormone (α-MSH) peptides using bifunctional chelating agents. MAG3-GGNle-CycMSHhex, AcCG3-GGNle-CycMSHhex and HYNIC-GGNle-CycMSHhex peptides were synthesized and their melanocortin-1 (MC1) receptor binding affinities were determined in B16/F1 melanoma cells. The biodistribution of 99mTc-MAG3-GGNle-CycMSHhex, 99mTc-AcCG3-GGNle-CycMSHhex, 99mTc(CO)3-HYNIC-GGNle-CycMSHhex and 99mTc(EDDA)-HYNIC-GGNle-CycMSHhex were determined in B16/F1 melanoma-bearing C57 mice at 2 h post-injection to select a lead peptide for further evaluation. The melanoma targeting and imaging properties of 99mTc(EDDA)-HYNIC-GGNle-CycMSHhex were further examined because of its high melanoma uptake and fast urinary clearance. The IC50 values of MAG3-GGNle-CycMSHhex, AcCG3-GGNle-CycMSHhex and HYNIC-GGNle-CycMSHhex were 1.0 ± 0.05, 1.2 ± 0.19 and 0.6 ± 0.04 nM in B16/F1 melanoma cells, respectively. Among these four 99mTc-peptides, 99mTc(EDDA)-HYNIC-GGNle-CycMSHhex exhibited the highest melanoma uptake (14.14 ± 4.90% ID/g) and fastest urinary clearance (91.26 ± 1.96% ID) at 2 h post-injection. 99mTc(EDDA)-HYNIC-GGNle-CycMSHhex showed high tumor to normal organ uptake ratios except for the kidneys. The tumor/kidney uptake ratios of 99mTc(EDDA)-HYNIC-GGNle-CycMSHhex were 2.50 and 3.55 at 4 and 24 h post-injection. The melanoma lesions were clearly visualized by SPECT/CT using 99mTc(EDDA)-HYNIC-GGNle-CycMSHhex as an imaging probe at 2 h post-injection. Overall, high melanoma uptake coupled with fast urinary clearance of 99mTc(EDDA)-HYNIC-GGNle-CycMSHhex highlighted its potential for metastatic melanoma detection in the future. PMID:23418722

  1. Initial evaluation of 99m Tc-tricarbonyl-cyclopentadienyl fatty acids derivatives as SPECT tracers for myocardium.

    PubMed

    Liu, Jianping; Wang, Huan; Wang, Shuxia; Xue, Qianqian; Wang, Dawei; Wang, Hang; Zhang, Huabei

    2017-05-15

    Fatty acids are myocardial metabolic agent for detecting myocardial ischemia and infraction. However, no 99m Tc-labeled fatty acids had potential use in clinical practice. In this study, 99m Tc-CpTT-10-oxo-para-PPA (1d), 99m Tc-CpTT-11-oxo-para-PPA (2d), 99m Tc-CpTT-12-oxo-para-PPA (3d), 99m Tc-CpTT-11-oxo-ortho-PPA (4d), and 99m Tc-CpTT-11-oxo-meta-PPA (5d) were synthesized by a double ligand transfer reaction, and their biological behaviors were investigated. Compound 2d achieved good heart to blood ratio (3.39 at 5 min after intravenous), and 2d showed high-heart uptake of 6.20% ID/g at 5 minutes after injection. Compound 3d displayed a prolonged retention in the myocardium (1.43% ID/g at 60 min after injection). Radioactivity accumulation in the lungs, spleen, and blood was eliminated rapidly. In vivo, metabolite analysis presented that compound 6d may be metabolite of 2d through β-oxidation in tissue. Unfortunately, the biodistribution studies of 1d, 2d, 3d, 4d, and 5d showed fast heart clearance and poor heart to liver ratios, which suggested that the 5 99m Tc-labeled fatty acid analogues cannot be used for diagnosis. Copyright © 2017 John Wiley & Sons, Ltd.

  2. Multidetector Computed Tomography Features in Differentiating Exophytic Renal Angiomyolipoma from Retroperitoneal Liposarcoma

    PubMed Central

    Wang, Qiushi; Juan, Yu-Hsiang; Li, Yong; Xie, Jia-Jun; Liu, Hui; Huang, Hongfei; Liu, Zaiyi; Zheng, Junhui; Saboo, Ujwala S.; Saboo, Sachin S.; Liang, Changhong

    2015-01-01

    Abstract This study aims to evaluate the multidetector computed tomography (CT) imaging features in differentiating exophytic renal angiomyolipoma (AML) from retroperitoneal liposarcoma. We retrospectively enrolled 42 patients with confirmed exophytic renal AML (31 patients) or retroperitoneal liposarcoma (11 patients) during 8 years period to assess: renal parenchymal defect at site of tumor contact, supply from branches of renal artery, tumoral vessel extending through the renal parenchyma, dilated intratumoral vessels, hemorrhage, non–fat-containing intratumoral nodules with postcontrast enhancement, calcification, renal sinus enlargement, anterior displacement of kidneys, and other associated AML. Renal parenchymal defect, renal arterial blood supply, tumoral vessel through the renal parenchyma, dilated intratumoral vessels, intratumoral/perirenal hemorrhage, renal sinus enlargement, and associated AML were seen only or mainly in exophytic renal AML (all P value < 0.05); however, non–fat-attenuating enhancing intratumoral nodules, intratumoral calcification, and anterior displacement of the kidney were more common in liposarcoma (all P value < 0.05). AMLs reveal renal parenchymal defect at the site of tumor contact, supply from renal artery, tumoral vessel extending through the renal parenchyma, dilated intratumoral vessels, intratumoral and/or perirenal hemorrhage, renal sinus enlargement, and associated AML. Non–fat-attenuating enhancing intratumoral nodules, intratumoral calcifications, and anterior displacement of kidney were more commonly seen in liposarcoma. PMID:26376398

  3. TC-1 Overexpression Promotes Cell Proliferation in Human Non-Small Cell Lung Cancer that Can Be Inhibited by PD173074

    PubMed Central

    Zhang, Na; Bai, Guangzhen; Zhong, Daixing; Su, Kai; Liu, Boya; Li, Xiaofei; Wang, Yunjie; Wang, Xiaoping

    2014-01-01

    Thyroid cancer-1 (TC-1), a natively disordered protein, is widely expressed in vertebrates and overexpressed in many kinds of tumors. However, its exact role and regulation mechanism in human non-small cell lung cancer (NSCLC) are still unclear. In the present study, we found that TC-1 is highly expressed in NSCLC and that its aberrant expression is strongly associated with NSCLC cell proliferation. Exogenous TC-1 overexpression promotes cell proliferation, accelerates the cell G1-to-S-phase transition, and reduces apoptosis in NSCLC. The knockdown of TC-1, however, inhibits NSCLC cell proliferation, cycle transition, and apoptosis resistance. Furthermore, we also demonstrated that PD173074, which functions as an inhibitor of the TC-1 in NSCLC, decreases the expression of TC-1 and inhibits TC-1 overexpression mediated cell proliferation in vitro and in vivo. Nevertheless, the inhibition function of PD173074 on NSCLC cell proliferation was eliminated in cells with TC-1 knockdown. These results suggest that PD173074 plays a significant role in TC-1 overexpression mediated NSCLC cell proliferation and may be a potential intervention target for the prevention of cell proliferation in NSCLC. PMID:24941347

  4. Growth And Patterning Of High-Tc Superconducting Films

    NASA Technical Reports Server (NTRS)

    Warner, J. D.; Bhasin, K. B.; Varaljay, N. C.; Bohman, D. Y.; Chorey, C. M.

    1992-01-01

    Superconducting films of YBa(2)Cu(3)O(7-delta), having high superconducting-transition temperatures (Tc's), deposited on LaAlO3 substrates and etched into patterns representative of passive microwave devices, with no deterioration of superconducting properties.

  5. Potential high-Tc superconducting lanthanum and yttrium hydrides at high pressure

    PubMed Central

    Liu, Hanyu; Naumov, Ivan I.; Hoffmann, Roald; Ashcroft, N. W.; Hemley, Russell J.

    2017-01-01

    A systematic structure search in the La–H and Y–H systems under pressure reveals some hydrogen-rich structures with intriguing electronic properties. For example, LaH10 is found to adopt a sodalite-like face-centered cubic (fcc) structure, stable above 200 GPa, and LaH8 a C2/m space group structure. Phonon calculations indicate both are dynamically stable; electron phonon calculations coupled to Bardeen–Cooper–Schrieffer (BCS) arguments indicate they might be high-Tc superconductors. In particular, the superconducting transition temperature Tc calculated for LaH10 is 274–286 K at 210 GPa. Similar calculations for the Y–H system predict stability of the sodalite-like fcc YH10 and a Tc above room temperature, reaching 305–326 K at 250 GPa. The study suggests that dense hydrides consisting of these and related hydrogen polyhedral networks may represent new classes of potential very high-temperature superconductors. PMID:28630301

  6. Anomalous Normal State and Quasi Particle Transport in High-Tc Superconductors

    NASA Astrophysics Data System (ADS)

    Ong, N. P.

    1997-03-01

    The quasi-particles (qp) below Tc are much less studied compared to excitations of the normal state. The thermal conductivity tensor κ_ij provides a window on their transport properties. In YBaCuO, the large thermal Hall response allows the qp mean-free-path l to be estimated. l rises rapidly from 90 Åat Tc to over 6,000 Åat 20 K in untwinned crystals. The intense scattering rate above Tc is rapidly suppressed, leaving qp's that travel great distances at low T. In LaSrCuO, where there is substantial disorder, κ_xx varies logarithmically with field B. While the field dependence is entirely electronic, it is incompatible with scattering from vortices. κ_xx fits well to the digamma function form ψ(1/2+ fracB_0B) + ln(fracBB_0), with a T-linear field-scale B_0. Possible field destruction of a quantum interference effect or depairing effects in a d-wave superconductor will be discussed.

  7. Diagnostic accuracy of [99mTc]Tc-Sestamibi in the assessment of thyroid nodules

    PubMed Central

    Yordanova, Anna; Mahjoob, Soha; Lingohr, Philipp; Kalff, Jörg; Türler, Andreas; Palmedo, Holger; Biersack, Hans-Jürgen; Kristiansen, Glen; Farahati, Jamshid; Essler, Markus; Ahmadzadehfar, Hojjat

    2017-01-01

    [99mTc]Tc-Sestamibi (MIBI) is an increasingly used tool for evaluation of thyroid nodules. However, there is a lack of evidence about the accuracy of this method in the European population. The aim of this study was to assess the utility of MIBI for the differentiation of thyroid nodules in a large cohort. 161 patients underwent MIBI, followed by a thyroidectomy. We used a dual phase MIBI protocol. Interpretation of the images included a scoring system from 0 (absent) to 3 (increased); this was to provide a scale for the uptake of the thyroid nodule in comparison to the paranodular tissue. Additionally, we evaluated the tracer uptake trend in late images compared to early images. We used the final histopathology as the reference standard. Scores 0-1 in early images, scores 0-2 in late images, and an absence of increasing uptake in the thyroid nodule in late images, showed the best predictive values to exclude malignancy, respectively (negative predictive value (NPV) 89%). Highest sensitivity (91%) for malignant nodules was evident in early images with a score 1-3. Highest specificity (91%) was obtained when the negative was defined as an absence of uptake-increase, in the late images. This study confirms that the most valuable feature of MIBI is the high NPV. Thus, with the appropriate interpretation method, high sensitivity and specificity, and moderate PPV can be obtained. PMID:29212258

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

    PubMed

    Wu, Dapeng; Li, Lei; Yan, Wei

    2016-04-15

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

  9. Improved synthesis and biological evaluation of Tc-99m radiolabeled AMO for miRNA imaging in tumor xenografts.

    PubMed

    Kang, Lei; Fan, Zhongyi; Sun, Hongwei; Feng, Yingying; Ma, Chao; Yan, Ping; Zhang, Chunli; Ma, Huan; Hao, Pan; Chen, Xueqi; Zheng, Zhibing; Xu, Xiaojie; Wang, Rongfu

    2015-01-01

    MicroRNAs (miRNAs) have been considered as important biomarkers for malignant tumors. In this study, we introduced an improved (99m)Tc labeling method for noninvasive visualization of overexpressed miRNAs in tumor-bearing mice. Anti-miRNA-21 oligonucleotide (AMO) with partial 2'-O-methyl and phosphorothioate modification was designed and chemically synthesized. After conjugated with NHS-MAG3, AMO was labeled with (99m)Tc. Optimization was made to shorten reaction time and to improve labeling efficiency. Labeling efficiency was 97%, and specific activity was 2.78 MBq/ng. During 12 h, (99m)Tc-AMO showed no significant degradation by gel electrophoresis. Its radiochemical purity was stable, between 95.8% and 99.1%. Further, (99m)Tc-AMO decreased the level of miR-21 and increased the expression of PTEN protein at cellular level, shown by qRT-PCR and Western blot. Fluorescent protein labeled AMO displayed specific distribution and good stability in tumor cells. After the administration in tumor-bearing mice, (99m)Tc-AMO showed more radioactive uptake in the miR-21 over-expressed tumors than scramble control. Biodistribution results further proved the significant difference of tumor uptake between (99m)Tc-AMO and (99m)Tc-control. Therefore, this study presents an improved method with shorten time to prepare a (99m)Tc radiolabeled AMO. In addition, it supports the role of (99m)Tc-AMO for noninvasive visualization of miR-21 in malignant tumors. Copyright © 2015 John Wiley & Sons, Ltd.

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

    PubMed Central

    Wu, Dapeng; Li, Lei; Yan, Wei

    2016-01-01

    ABSTRACT Thyroid cancer 1 (TC-1, C8ofr4) is widely expressed in vertebrates and associated with many kinds of tumors. Previous studies indicated that TC-1 functions as a positive regulator in the Wnt/β-catenin signaling pathway in non-small cell lung cancer (NSCLC). However, its exact role and regulation mechanism in radiosensitivity of NSCLC are still unclear. The expression level of TC-1 was measured by qRT-PCR and western blot in NSCLC cell lines. Proliferation and apoptosis of NSCLC cells in response to TC-1 knockdown or/and radiation were determined by MTT assay and flow cytometry, respectively. The activation of the Wnt/β-catenin signaling pathway was further examined by western blot in vitro and in vivo. Compared to TC-1 siRNA or radiotherapy alone, TC-1 silencing combined with radiation inhibited cell proliferation and induced apoptosis in NSCLC cell lines by inactivating of the Wnt/β-catenin signaling pathway. Furthermore, inhibition of the Wnt/β-catenin signaling pathway by XAV939, a Wnt/β-catenin signaling inhibitor, contributed to proliferation inhibition and apoptosis induction in NSCLC A549 cells. Combinative treatment of A549 xenografts with TC-1 siRNA and radiation caused significant tumor regression and inactivation of the Wnt/β-catenin signaling pathway relative to TC-1 siRNA or radiotherapy alone. The results from in vitro and in vivo studies indicated that TC-1 silencing sensitized NSCLC cell lines to radiotherapy through the Wnt/β-catenin signaling pathway. PMID:27029901

  11. 99mTc-tagged chicken liver as a marker of solid food in the human stomach.

    PubMed

    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.

  12. The importance of Tc-MAA SPECT/CT for therapy planning of radioembolization in a patient treated with bevacizumab.

    PubMed

    Ahmadzadehfar, Hojjat; Sabet, Amir; Meyer, Carsten; Habibi, Elham; Biersack, Hans-Jürgen; Ezziddin, Samer

    2012-11-01

    A 76-year-old man with colorectal cancer and hepatic metastases was referred to us for radioembolization of the liver. Angiography with 99mTc-MAA SPECT/CT was performed 8 weeks after the discontinuation of bevacizumab. 99mTc-MAA SPECT/CT showed a diffused intrahepatic tracer distribution with no focally accentuated accumulation in the tumorous region. The test was repeated 6 weeks later and Tc-MAA SPECT/CT showed this time a tumor accentuated tracer accumulation in the liver. Subsequently, the patient was treated with resin microspheres. Tc-MAA SPECT/CT allows a better evaluation of intrahepatic tracer accumulation of Tc-MAA and facilitates the determination of the most appropriate treatment time.

  13. 2'β-Fluoro-Tricyclo Nucleic Acids (2'F-tc-ANA): Thermal Duplex Stability, Structural Studies, and RNase H Activation.

    PubMed

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

    2017-08-01

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

  14. (99m)Tc-labeled SWL specific peptide for targeting EphA2 receptor.

    PubMed

    Liu, Yu; Lan, Xiaoli; Wu, Tao; Lang, Juntao; Jin, Xueyan; Sun, Xun; Wen, Qiong; An, Rui

    2014-07-01

    EphA2, one member of the Eph receptor family, is widely expressed in multiple aggressive cancers. SWL, a small peptide identified by phage display, has high binding affinity to EphA2, suggesting that it could be exploited for targeted molecular imaging. Therefore, a novel peptide-based probe, (99m)Tc-HYNIC-SWL, was developed and its potential to specifically target EphA2-positive tumors was investigated. The SWL peptide was labeled with hydrazinonicotinic acid (HYNIC), followed by (99m)Tc labeling. Immunofluorescence staining was carried out to detect the expression of EphA2 in A549 lung cancer cells and OCM-1 melanoma cells. Saturation binding experiments were performed by incubating A549 cells with increasing concentrations of radiolabeled peptide in vitro. To test the probe in vivo, nude mice bearing either A549 or OCM-1 derived tumors were established, injected with (99m)Tc-HYNIC-SWL, and subjected to SPECT imaging. Mice injected with excess unlabeled SWL were used as a specific control. Ex vivo γ-counting of dissected tissues from the mice was also performed to evaluate biodistribution. Immunofluorescence staining showed that A549 cells intensively expressed EphA2, while OCM-1 cells had little expression. (99m)Tc-HYNIC-SWL displayed high binding affinity with A549 cells (KD=2.6±0.7nM). From the SPECT images and the results of the biodistribution study, significantly higher uptake of the tracer was seen in A549 tumors (1.44±0.12 %ID/g) than in OCM-1 tumors (0.43±0.20 %ID/g) at 1h after injection. Pre-injection with excess unlabeled peptide in A549-bearing nude mice, significantly reduced tumor uptake of the radiolabeled probe (0.58±0.20 %ID/g) was seen. These data suggest that (99m)Tc-HYNIC-SWL specifically targets EphA2 in tumors. The expression of EphA2 can be noninvasively investigated using (99m)Tc-HYNIC-SWL by SPECT imaging. The in vitro and in vivo characteristics of (99m)Tc-HYNIC-SWL make it a promising probe for EphA2-positive tumor imaging

  15. Evaluation of polyethylene glycol coated liposomes labeled with Tc-99m as a blood pool agent

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Phillips, W.T.; Klipper, R.; Goins, B.

    1994-05-01

    This investigation evaluated Tc-99m liposomes coated with polyethylene glycol (PEG) as a blood pool agent in comparison with Tc-99m liposomes carrying no surface charge (Neutral) and with Tc-99m autologous red cells. Liposomes (135 nm diameter) encapsulating glutathione were labeled with Tc-99m using the lipophilic chelator, HMPAO as previously described. Autologous red cells were labeled using an Ultratag kit. Labeling efficiencies averaged 66%, 52%, and 97% for the PEG liposomes. Neutral liposomes, and red cells, respectively. Rabbits (3-3.5 Kg) were injected IV via ear vein with 2.0 mls of PEG liposomes (2 mCi, 17 mg phospholipid/Kg body weight, n=5). Neutral liposomesmore » (1.3 mCi, 17 mg phospholipid/Kg body weight, n=4), or red cells (2.6 mCi, n=2). Gamma camera images were acquired at 5,22, and 45 minutes, and 2,20,and 44 hours post-injection. Blood samples were obtained at each time point to determine clearance kinetics. Circulation half lives of both Tc-99m liposome formulations were longer than Tc-99m red cells (8 hrs), with the half life of PEG liposomes (35 hrs) 1.6 times longer than Neutral liposomes (22 hrs). In vivo stability of the Tc-99m label was excellent for the liposomes with only 3.5-4% bladder activity at 45 minutes compared to 12% bladder activity for the red cells. Excellent blood pool images were obtained for the PEG liposomes in the rabbit. Heart/liver ratios calculated from region of interest analysis of 45 minutes images were 1.9, 1.5, and 1.7 for PEG liposomes, Neutral liposomes and red cells. This study demonstrates the feasibility of using Tc-99m PEG liposomes to perform gated cardiac blood pool and rapid gastrointestinal bleeding studies.« less

  16. Dissecting the phyloepidemiology of Trypanosoma cruzi I (TcI) in Brazil by the use of high resolution genetic markers.

    PubMed

    Roman, Fabiola; das Chagas Xavier, Samanta; Messenger, Louisa A; Pavan, Márcio G; Miles, Michael A; Jansen, Ana María; Yeo, Matthew

    2018-05-01

    Trypanosoma cruzi, the causal agent of Chagas disease, is monophyletic but genetically heterogeneous. It is currently represented by six genetic lineages (Discrete Typing Units, DTUs) designated TcI-TcVI. TcI is the most geographically widespread and genetically heterogeneous lineage, this as is evidenced by a wide range of genetic markers applied to isolates spanning a vast geographic range in Latin America. In total, 78 TcI isolated from hosts and vectors distributed in 5 different biomes of Brazil, were analyzed using 6 nuclear housekeeping genes, 25 microsatellite loci and one mitochondrial marker. Nuclear markers reveal substantial genetic diversity, significant gene flow between biomes, incongruence in phylogenies, and haplotypic analysis indicative of intra-DTU genetic exchange. Phylogenetic reconstructions based on mitochondrial and nuclear loci were incongruent, and consistent with introgression. Structure analysis of microsatellite data reveals that, amongst biomes, the Amazon is the most genetically diverse and experiences the lowest level of gene flow. Investigation of population structure based on the host species/genus, indicated that Didelphis marsupialis might play a role as the main disperser of TcI. The present work considers a large TcI sample from different hosts and vectors spanning multiple ecologically diverse biomes in Brazil. Importantly, we combine fast and slow evolving markers to contribute to the epizootiological understanding of TcI in five distinct Brazilian biomes. This constitutes the first instance in which MLST analysis was combined with the use of MLMT and maxicircle markers to evaluate the genetic diversity of TcI isolates in Brazil. Our results demonstrate the existence of substantial genetic diversity and the occurrence of introgression events. We provide evidence of genetic exchange in TcI isolates from Brazil and of the relative isolation of TcI in the Amazon biome. We observe the absence of strict associations with Tc

  17. Effect of Dietary Intake of Stable Iodine on Dose-per-unit-intake Factors for 99Tc

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Strom, Daniel J.

    It is well-known that the human thyroid concentrates iodine more than 100 times the concentration in plasma. Also well-known is the fact that large amounts of stable iodine in the diet can limit thyroid uptake of total iodine; this is the basis for administering potassium iodide following a release of radioiodine from a nuclear reactor accident or nuclear weapon detonation. Many researchers have shown enhanced concentrations of both organic and inorganic iodine in saliva and breast milk. Technetium-99 is a long-lived (231,000 year half-life) radionuclide of concern in the management of high-level radioactive waste. There is no doubt that 99Tc,more » if it is in groundwater, will be found in the chemical form of pertechnetate, 99TcO4?. Pertechnetate is a large anion, almost identical in size to iodide, I?. The nuclear medicine literature shows that pertechnetate concentrates in the thyroid, salivary glands, and lactating breast in addition to the stomach, liver, and alimentary tract as currently recognized by the International Commission on Radiological Protection (ICRP). The fact that large intakes of stable iodine (127I) in the diet limit uptake of iodine by the thyroid leads one to generalize that stable iodine in the diet may also limit thyroid uptake of pertechnetate. While there is at least one report that iodine in the diet blocks uptake of 99mTcO4? by the thyroid and salivary glands (which have the same Na/I symporter, the biochemical concentration mechanism), the level of protective effect seen for blocking radioactive iodine is not expected for 99TcO4? because pertechnetate does not become organically bound in the thyroid and thus is not retained for months the way iodide is. While it does account for Tc concentration in the thyroid, the existing ICRP biokinetic model for technetium does not take enhanced concentrations in salivary gland and breast tissue into account. From the survey of the nuclear medicine literature, it is not possible to compute the

  18. Effects of dose reduction on multi-detector computed tomographic images in evaluating the maxilla and mandible for pre-surgical implant planning: a cadaveric study.

    PubMed

    Koizumi, Hiroshi; Sur, Jaideep; Seki, Kenji; Nakajima, Koh; Sano, Tsukasa; Okano, Tomohiro

    2010-08-01

    To assess effects of dose reduction on image quality in evaluating maxilla and mandible for pre-surgical implant planning using cadavers. Six cadavers were used for the study using multi-detector computed tomography (CT) operated at 120 kV and the variable tube current of 80, 40, 20 and 10 mA. A slice thickness of 0.625 mm and pitch 1 were used. Multi-planar images perpendicular and parallel to dentitions were created. The images were evaluated by five oral radiologists in terms of visibility of the anatomical landmarks including alveolar crest, mandibular canal, floors of the maxillary sinus and nasal cavity, contours/cortical layer of jaw bones and the details of trabecular bone. Observers were asked to determine the quality of the images in comparison with 80 mA images based on the criteria: excellent, good, fair or non-diagnostic. The average scores of all observers were calculated for each specimen in all exposure conditions. The 40 mA images could visualize such landmarks and were evaluated to be same or almost equivalent in quality to the 80 mA images. Even the 20 mA images could be accepted just for diagnostic purpose for implant with substantial deterioration of the image quality. The 10 mA images may not be accepted because of the obscured contour caused by image noise. Significant dose reduction by lowering mA can be utilized for pre-surgical implant planning in multi-detector CT.

  19. Adsorption of (99m)Tc-radiopharmaceuticals onto injection vials and syringes.

    PubMed

    Mushtaq, Ahmad; Ur Rehman, Taj; Safdar Mansur, Muhammad; Jehangir, Mustanser

    2008-06-01

    Many groups have reported the adsorption or retention of (99m)Tc-radiopharmaceuticals on injection vials and disposable plastic syringes. Such an enormously high loss of radioactivity would result in poor images, radiation exposure, waste, and economic burdens. We therefore decided to investigate the extent of adsorption or retention of several (99m)Tc-radiopharmaceuticals on injection vials, rubber stoppers, and plastic syringes. These radiopharmaceuticals are produced as lyophilized kits in our department and supplied to various hospitals practicing nuclear medicine in Pakistan. A vial containing lyophilized material was reconstituted with 3 mL of freshly eluted Na(99m)TcO(4). A 1-mL aliquot of the resulting solution was withdrawn into a syringe at 0.25, 0.5, 1, 3, and 5 h after preparation. All preparations were stored at room temperature ( approximately 22 degrees C). After each withdrawal, the vial was reweighed and the activity remaining in the vial was measured using a radioisotope calibrator. The sample was reinjected into the vial. From the original weight and activity of solution in the vial, the initial activity per gram was calculated. From the weight and activity remaining in the vial after withdrawal of the sample, the activity per gram of the sample was calculated. From the difference between the initial activity per gram and the activity per gram of the sample, the percentage of (99m)Tc adsorbed on the vial was calculated. All preparations were kept in the syringe for 15 min, and the activity was measured before and after the syringe was emptied. The needle and plunger of the syringe were separated, and activity in the needle and plunger was also measured. The labeling efficiency of all radiopharmaceuticals used during these studies was more than 95%. In most cases, the activity of (99m)Tc found on the rubber stopper was less than 1%. Adsorption of (99m)Tc onto vials increased gradually with storage time. Adsorption was minimal at the initial stages

  20. Trypanosoma cruzi TcSMUG L-surface mucins promote development and infectivity in the triatomine vector Rhodnius prolixus.

    PubMed

    Gonzalez, Marcelo S; Souza, Marcela S; Garcia, Eloi S; Nogueira, Nadir F S; Mello, Cícero B; Cánepa, Gaspar E; Bertotti, Santiago; Durante, Ignacio M; Azambuja, Patrícia; Buscaglia, Carlos A

    2013-11-01

    TcSMUG L products were recently identified as novel mucin-type glycoconjugates restricted to the surface of insect-dwelling epimastigote forms of Trypanosoma cruzi, the etiological agent of Chagas disease. The remarkable conservation of their predicted mature N-terminal region, which is exposed to the extracellular milieu, suggests that TcSMUG L products may be involved in structural and/or functional aspects of the interaction with the insect vector. Here, we investigated the putative roles of TcSMUG L mucins in both in vivo development and ex vivo attachment of epimastigotes to the luminal surface of the digestive tract of Rhodnius prolixus. Our results indicate that the exogenous addition of TcSMUG L N-terminal peptide, but not control T. cruzi mucin peptides, to the infected bloodmeal inhibited the development of parasites in R. prolixus in a dose-dependent manner. Pre-incubation of insect midguts with the TcSMUG L peptide impaired the ex vivo attachment of epimastigotes to the luminal surface epithelium, likely by competing out TcSMUG L binding sites on the luminal surface of the posterior midgut, as revealed by fluorescence microscopy. Together, these observations indicate that TcSMUG L mucins are a determinant of both adhesion of T. cruzi epimastigotes to the posterior midgut epithelial cells of the triatomine, and the infection of the insect vector, R. prolixus.

  1. Enhanced inhibitory synaptic transmission in the spinal dorsal horn mediates antinociceptive effects of TC-2559

    PubMed Central

    2011-01-01

    Background TC-2559 is a selective α4β2 subtype of nicotinic acetylcholine receptor (nAChR) partial agonist and α4β2 nAChR activation has been related to antinociception. The aim of this study is to investigate the analgesic effect of TC-2559 and its underlying spinal mechanisms. Results 1) In vivo bioavailability study: TC-2559 (3 mg/kg) had high absorption rate in rats with maximal total brain concentration reached over 4.6 μM within first 15 min after administration and eliminated rapidly with brain half life of about 20 min after injection. 2) In vivo behavioral experiments: TC-2559 exerts dose dependent antinociceptive effects in both formalin test in mice and chronic constriction injury (CCI) model in rats by activation of α4β2 nAChRs; 3) Whole-cell patch-clamp studies in the superficial dorsal horn neurons of the spinal cord slices: perfusion of TC-2559 (2 μM) significantly increased the frequency, but not amplitude of spontaneous inhibitory postsynaptic currents (sIPSCs). The enhancement of sIPSCs was blocked by pre-application of DHβE (2 μM), a selective α4β2 nicotinic receptor antagonist. Neither the frequency nor the amplitude of spontaneous excitatory postsynaptic currents (sEPSCs) of spinal dorsal horn neurons were affected by TC-2559. Conclusions Enhancement of inhibitory synaptic transmission in the spinal dorsal horn via activation of α4β2 nAChRs may be one of the mechanisms of the antinociceptive effects of TC-2559 on pathological pain models. It provides further evidence to support the notion that selective α4β2 subtype nAChR agonist may be developed as new analgesic drug for the treatment of neuropathic pain. PMID:21816108

  2. A randomized multicenter clinical trial of 99 Tc-methylene diphosphonate in treatment of rheumatoid arthritis.

    PubMed

    Mu, Rong; Liang, Jun; Sun, Lingyun; Zhang, Zhuoli; Liu, Xiangyuan; Huang, Cibo; Zhu, Ping; Zuo, Xiaoxia; Gu, Jieruo; Li, Xiangpei; Li, Xingfu; Liu, Yi; Feng, Ping; Li, Zhanguo

    2018-01-01

    To investigate the efficacy and safety of technetium-99 conjugated with methylene diphosphonate ( 99 Tc-MDP, Yunke Pharmaceutical industry) in the treatment of rheumatoid arthritis (RA). A total of 120 patients with active RA were randomly divided into three groups: Group A (receiving oral meloxicam tablets); Group B (receiving intravenous drip of 99 TC-MDP); Group C (receiving combination treatment of intravenous drip of 99 Tc-MDP and oral meloxicam tablets). The main clinical and laboratory parameters were evaluated at baseline and after 14 days of therapy. After 14 days of treatment, American College of Rheumatology 20 response was 15.62%, 34.04% and 48.78% in the three groups, respectively. The incidence of adverse events in three groups were 3.13%, 8.51% and 9.76% respectly, and has no significant difference. In addition, biochemical markers of bone metabolism including bone alkaline phosphatase (BAP), tartrate resistant acid phosphatase (TRAP) and dickkopf-1 (DKK-1), all improved in the three groups, although more significant in Group B than Group A, and more significant in the combination group than monotherapy groups. 99 Tc-MDP has good efficacy and safety in the treatment of active RA patients; the benefit was more remarkable when 99 Tc-MDP was combined with NSAIDs. 99 Tc-MDP may also have potential to improve bone metabolism. © 2017 Asia Pacific League of Associations for Rheumatology and John Wiley & Sons Australia, Ltd.

  3. Long-Duration Space Flight Provokes Pathologic Q-Tc Interval Prolongation

    NASA Technical Reports Server (NTRS)

    D'Aunno, DOminick S.; Dougherty, Anne H.; DeBlock, Heidi F.; Meck, Janice V.

    2002-01-01

    Space flight has a profound influence on the cardiovascular and autonomic nervous systems. Alterations in baroreflex function, plasma catecholamine concentrations, and arterial pressure regulation have been observed. Changes in autonomic regulation of cardiac function may lead to serious rhythm disturbances. In fact, ventricular tachycardia has been reported during long-duration space flight. The study aim was to determine the effects of space flight on cardiac conduction. Methods and Results: Electrocardiograms (ECGs) and serum electrolytes were obtained before and after short-duration (SD) (4-16 days) and long-duration (LD) (4-6 months) missions. Holter recordings were obtained from 3 different subjects before, during and after a 4-month mission. P-R, R-R, and Q-T intervals were measured manually in a random, blinded fashion and Bazzet's formula used to correct the Q-T interval (Q-Tc). Space flight had no clinically significant effect on electrolyte concentrations. P-R and RR intervals were decreased after SD flight (p<0.05) and recovered 3 days after landing. In the same subjects, P-R and Q-Tc intervals were prolonged after LD flight (p<0.01). Clinically significant Q-Tc prolongation (>0.44 sec) occurred during the first month of flight and persisted until 3 days after landing (p<0.01). Conclusions - Space flight alters cardiac conduction with more ominous changes seen with LD missions. Alterations in autonomic tone may explain ECG changes associated with space flight. Primary cardiac changes may also contribute to the conduction changes with LD flight. Q-Tc prolongation may predispose astronauts to ventricular arrhythmias during and after long-duration space flight.

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

    PubMed

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

    2012-01-01

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

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

    PubMed Central

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

    2012-01-01

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

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

    PubMed

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

    2014-09-01

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

  7. Clinical Trial with Sodium 99mTc-Pertechnetate Produced by a Medium-Energy Cyclotron: Biodistribution and Safety Assessment in Patients with Abnormal Thyroid Function.

    PubMed

    Selivanova, Svetlana V; Lavallée, Éric; Senta, Helena; Caouette, Lyne; McEwan, Alexander J B; Guérin, Brigitte; Lecomte, Roger; Turcotte, Éric

    2017-05-01

    A single-site prospective open-label clinical study with cyclotron-produced sodium 99m Tc-pertechnetate ( 99m Tc-NaTcO 4 ) was performed in patients with indications for a thyroid scan to demonstrate the clinical safety and diagnostic efficacy of the drug and to confirm its equivalence with conventional 99m Tc-NaTcO 4 eluted from a generator. Methods: 99m Tc-NaTcO 4 was produced from enriched 100 Mo (99.815%) with a cyclotron (24 MeV; 2 h of irradiation) or supplied by a commercial manufacturer (bulk vial eluted from a generator). Eleven patients received 325 ± 29 (mean ± SD) MBq of the cyclotron-produced 99m Tc-NaTcO 4 , whereas the age- and sex-matched controls received a comparable amount of the generator-derived tracer. Whole-body and thyroid planar images were obtained for each participant. In addition to the standard-energy window (140.5 keV ± 7.5%), data were acquired in lower-energy (117 keV ± 10%) and higher-energy (170 keV ± 10%) windows. Vital signs and hematologic and biochemical parameters were monitored before and after tracer administration. Results: Cyclotron-produced 99m Tc-NaTcO 4 showed organ and whole-body distributions identical to those of conventional 99m Tc-NaTcO 4 and was well tolerated. All images led to a clear final diagnosis. The fact that the number of counts in the higher-energy window was significantly higher for cyclotron-produced 99m Tc-NaTcO 4 did not influence image quality in the standard-energy window. Image definition in the standard-energy window with cyclotron-produced 99m Tc was equivalent to that with generator-eluted 99m Tc and had no particular features allowing discrimination between the 99m Tc production methods. Conclusion: The systemic distribution, clinical safety, and imaging efficacy of cyclotron-produced 99m Tc-NaTcO 4 in humans provide supporting evidence for the use of this tracer as an equivalent for generator-eluted 99m Tc-NaTcO 4 in routine clinical practice. © 2017 by the Society of Nuclear Medicine

  8. Assessment of Using 99Mo and 99mTc Isotopes in Kuwait Medical Sector.

    PubMed

    Ali, Naser

    2016-04-01

    The Ministry of Health (MOH) in the state of Kuwait currently depends on importing the radioisotope molybdenum (Mo) in its isotopic form (Mo) to fulfill its demands. The present study was conducted on all nuclear medicine departments in the state of Kuwait. Daily, weekly, and monthly data were analyzed to statistically determine the current and future demands for the isotope Tc. This analysis was performed by collecting and analyzing data on MOH consumption of Tc for different diagnostic applications. The overall results indicate a partial decrease of 1.012% in the overall total demand for Tc up to the year 2018 for the state of Kuwait.

  9. Development of kit formulations for (99m) TcN-MPO: a cationic radiotracer for myocardial perfusion imaging.

    PubMed

    Zheng, Yumin; Ji, Shundong; Tomaselli, Elena; Liu, Shuang

    2014-07-01

    The objective of this study was to develop a kit formulation for [(99m) TcN(mpo)(PNP5)](+) (MPO = 2-mercaptopyridine oxide), ((99m) TcN-MPO) to support its clinical evaluations as a SPECT radiotracer. Radiolabeling studies were performed using three different formulations (two-vial formulation and single-vial formulations with/without SnCl2 ) to explore the factors influencing radiochemical purity (RCP) of (99m) TcN-MPO. We found that the most important factor affecting the RCP of (99m) TcN-MPO was the purity of PNP5. (99m) TcN-MPO was prepared >98% RCP (n = 20) using the two-vial formulation. For single-vial formulations with/without SnCl2 , β-cyclodextrin (β-CD) is particularly useful as a stabilizer for PNP5. The RCP of (99m) TcN-MPO was 95-98% using β-CD, but its RCP was only 90-93% with γ-cyclodextrin (γ-CD). It seems that PNP5 fits better into the inner cavity of β-CD, which forms more stable inclusion complex than γ-CD in the single-vial formulations. The results from biodistribution and imaging studies in Sprague-Dawley rats clearly demonstrated biological equivalence of three different formulations. Single photon-emission computed tomography data suggested that high quality images could be obtained at 0-30-min post-injection without significant interference from the liver radioactivity. Considering the ease for (99m) Tc-labeling and high RCP of (99m) TcN-MPO, the non-SnCl2 single-vial formulation is an attractive choice for future clinical studies. Copyright © 2014 John Wiley & Sons, Ltd.

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

    PubMed

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

    2016-05-01

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

  11. [Evaluation of left ventricular diastolic function using gated SPECT with 99mTc-MIBI].

    PubMed

    Toba, M; Kumita, S I; Mizumura, S; Cho, K; Kijima, T; Takahama, K; Kumazaki, T

    1996-04-01

    Development of 3 head SPECT system and 99mTc-labeled radiopharmaceuticals enable us to evaluate left ventricular systolic function on the basis of once gated SPECT routine. This study was focused on assessment of left ventricular diastolic function using 99mTc-MIBI gated SPECT data. Twenty nine patients with ischemic heart diseases underwent 99mTc-MIBI gated SPECT and 99mTc-HSAD ventriculographic assessment of left ventricular diastolic function within 1 month. Region of interests (ROI), simultaneously calculating counts per pixel within ROI, were placed over whole myocardium of 16 serial phasic images reconstructed from gated SPECT data, following selection of the central slice within short axial images. Then, 29 patients were classified into 3 patterns of phase count curve (normal, mixed, and delayed relaxation = diastolic dysfunction). Moreover, 1/3 Count Decreasing Fraction (1/3 CDF) was calculated on the same concept as 1/3 FF. The curve pattern showed significant differences between normal and abnormal group divided on the basis of established indices such as 1/3 FF and PFR, and 1/3 CDF has correlations with 1/3 FF (r = 0.61) and PFR (r = 0.58). We concluded that the new parameters drawn from 99mTc-MIBI gated SPECT data might be feasible for evaluation of diastolic function.

  12. Liquid scintillation counting methodology for 99Tc analysis. A remedy for radiopharmaceutical waste

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Khan, Mumtaz; Um, Wooyong

    2015-08-13

    This paper presents a new approach for liquid scintillation counting (LSC) analysis of single-radionuclide samples containing appreciable organic or inorganic quench. This work offers better analytical results than existing LSC methods for technetium-99 ( 99gTc) analysis with significant savings in analysis cost and time. The method was developed to quantify 99gTc in environmental liquid and urine samples using LSC. Method efficiency was measured in the presence of 1.9 to 11,900 ppm total dissolved solids. The quench curve was proved to be effective in the case of spiked 99gTc activity calculation for deionized water, tap water, groundwater, seawater, and urine samples.more » Counting efficiency was found to be 91.66% for Ultima Gold LLT (ULG-LLT) and Ultima Gold (ULG). Relative error in spiked 99gTc samples was ±3.98% in ULG and ULG-LLT cocktails. Minimum detectable activity was determined to be 25.3 mBq and 22.7 mBq for ULG-LLT and ULG cocktails, respectively. A pre-concentration factor of 1000 was achieved at 100°C for 100% chemical recovery.« less

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

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Hinkle, G.H.; Basmadjian, G.P.; Peek, C.

    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 withmore » 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.« less

  14. The Aurora kinase A inhibitor TC-A2317 disrupts mitotic progression and inhibits cancer cell proliferation

    PubMed Central

    Min, Yoo Hong; Kim, Wootae; Kim, Ja-Eun

    2016-01-01

    Mitotic progression is crucial for the maintenance of chromosomal stability. A proper progression is ensured by the activities of multiple kinases. One of these enzymes, the serine/threonine kinase Aurora A, is required for proper mitosis through the regulation of centrosome and spindle assembly. In this study, we functionally characterized a newly developed Aurora kinase A inhibitor, TC-A2317. In human lung cancer cells, TC-A2317 slowed proliferation by causing aberrant formation of centrosome and microtubule spindles and prolonging the duration of mitosis. Abnormal mitotic progression led to accumulation of cells containing micronuclei or multinuclei. Furthermore, TC-A2317–treated cells underwent apoptosis, autophagy or senescence depending on cell type. In addition, TC-A2317 inactivated the spindle assembly checkpoint triggered by paclitaxel, thereby exacerbating mitotic catastrophe. Consistent with this, the expression level of Aurora A in tumors was inversely correlated with survival in lung cancer patients. Collectively, these data suggest that inhibition of Aurora kinase A using TC-A2317 is a promising target for anti-cancer therapeutics. PMID:27713168

  15. TC > 0.05 as a Pharmacokinetic Parameter of Paclitaxel for Therapeutic Efficacy and Toxicity in Cancer Patients.

    PubMed

    Xin, D S; Zhou, L; Li, C Z; Zhang, S Q; Huang, H Q; Qiu, G D; Lin, L F; She, Y Q; Zheng, J T; Chen, C; Fang, L; Chen, Zhe-Sheng; Zhang, S Y

    2018-03-05

    Paclitaxel (PTX) has remarkable anti-tumor activity, but it causes severe toxicities. There is an urgent need to seek an appropriate pharmacokinetic parameter of PTX to improve treatment efficacy and reduce adverse effects. To evaluate the association of pharmacokinetic parameter TC>0.05 of paclitaxel (PTX) and its therapeutic efficacy and toxicity in patients with solid tumors. A total of 295 patients with ovarian cancer, esophageal cancer, breast cancer, and non-small cell lung cancer (NSCLC), who were admitted to the Tumor Hospital of Shantou University Medical College, China, were recruited for this study. Patients received 3 weeks of PTX chemotherapy. The plasma concentrations of PTX were examined using the MyPaclitaxelTM kit. The patients' PTX TC>0.05 (the time during which PTX plasma concentration exceed 0.05 μmol/L) were calculated based on pharmacokinetic analysis. The results showed that: (1) the concentrations of PTX in these 295 patients ranged from 0.0358-0.127 μmol/L; (2) the PTX TC> 0.05 ranged from 14 to 38 h with a median time of 27 h; (3) among all treatment cycles, there was a statistically significant difference in the PTX TC>0.05 between CR+PR and SD+PD; (4) with the increasing value of TC>0.05, level of leukopenia and leukopenic fever increased; (5) high PTX TC>0.05 led to the occurrence of neutropenia, neutropenic fever, severe anemia, and severe peripheral neurotoxicity. Taken together, our results indicated that the pharmacokinetic parameter PTX TC>0.05 was an effective measure of treatment efficacy and toxicity in patients with solid tumors. Maintaining PTX TC>0.05 at 26 to 30 h could improve its efficacy and reduce the incidence of leukopenia, neutropenia, anemia, and peripheral neurotoxicity in these patients. PTX TC>0.05 is a key pharmacokinetic parameter of PTX which should be monitored to optimize individual treatment in patients with solid tumors. Copyright© Bentham Science Publishers; For any queries, please email at epub@benthamscience.org.

  16. Dissecting the phyloepidemiology of Trypanosoma cruzi I (TcI) in Brazil by the use of high resolution genetic markers

    PubMed Central

    das Chagas Xavier, Samanta; Messenger, Louisa A.; Pavan, Márcio G.; Miles, Michael A.; Jansen, Ana María; Yeo, Matthew

    2018-01-01

    Background Trypanosoma cruzi, the causal agent of Chagas disease, is monophyletic but genetically heterogeneous. It is currently represented by six genetic lineages (Discrete Typing Units, DTUs) designated TcI-TcVI. TcI is the most geographically widespread and genetically heterogeneous lineage, this as is evidenced by a wide range of genetic markers applied to isolates spanning a vast geographic range in Latin America. Methodology/Principal findings In total, 78 TcI isolated from hosts and vectors distributed in 5 different biomes of Brazil, were analyzed using 6 nuclear housekeeping genes, 25 microsatellite loci and one mitochondrial marker. Nuclear markers reveal substantial genetic diversity, significant gene flow between biomes, incongruence in phylogenies, and haplotypic analysis indicative of intra-DTU genetic exchange. Phylogenetic reconstructions based on mitochondrial and nuclear loci were incongruent, and consistent with introgression. Structure analysis of microsatellite data reveals that, amongst biomes, the Amazon is the most genetically diverse and experiences the lowest level of gene flow. Investigation of population structure based on the host species/genus, indicated that Didelphis marsupialis might play a role as the main disperser of TcI. Conclusions/Significance The present work considers a large TcI sample from different hosts and vectors spanning multiple ecologically diverse biomes in Brazil. Importantly, we combine fast and slow evolving markers to contribute to the epizootiological understanding of TcI in five distinct Brazilian biomes. This constitutes the first instance in which MLST analysis was combined with the use of MLMT and maxicircle markers to evaluate the genetic diversity of TcI isolates in Brazil. Our results demonstrate the existence of substantial genetic diversity and the occurrence of introgression events. We provide evidence of genetic exchange in TcI isolates from Brazil and of the relative isolation of TcI in the Amazon

  17. Imaging Thromboembolism with Fibrin-Avid 99mTc-Peptide: Evaluation in Swine

    PubMed Central

    Aruva, Mohan R.; Daviau, Judy; Sharma, Shubh S.; Thakur, Mathew L.

    2006-01-01

    A pentapeptide, Gly-Pro-Arg-Pro-Pro, with high affinity for α-chain-fibrin was labeled with 99mTc (99mTc-TP850) and evaluated in swine to image experimental venous thromboembolism (deep vein thrombosis [DVT]) and pulmonary embolism (PE). Methods Scatchard analysis was performed to determine fibrin affinity for TP850 and the number of binding sites (receptors) per milligram of fibrin. DVT was induced in the left jugular vein and PE was induced by introducing a preformed autologous blood clot into the right atrium using a 7-French introducer sheath inserted into the right jugular vein. 99mTc-TP850 was injected at 4, 24, 48, 72, 96, or 120 h later. Animals were imaged for up to 4 h after injection, heparinized, and sacrificed. Lungs were extirpated, radiographed, and imaged, and the PE was removed. Other tissues, including blood and normal lungs, were harvested and, concomitantly, 99mTc was counted for determination of target-to-tissue ratios and the percentage injected dose per gram of tissue. Results The affinity for human fibrin was 10−9 mol/L and there were >1015 receptors per milligram of fibrin. DVT and PE were visualized for up to 4 h after injection with high DVT/blood (7.9–22.6), DVT/muscle (31.1–89.4), PE/blood (1–155), and PE/lung (0.8–245) ratios. Thereafter, the PEs fragmented spontaneously below the spatial resolution of the γ-camera and, despite the high associated radioactivity, could not be localized in vivo. The fragmented clots were detectable by scintigraphy on excised lungs and provided excellent concordance with radiograms. Conclusion 99mTc-TP850 with its modest affinity (10−9 mol/L), rapid blood clearance, and high DVT and PE uptake is a promising agent for imaging vascular thrombosis. PMID:16391200

  18. Rapid diagnosis of occult abscesses using sup 99m Tc-labeled monoclonal antibodies

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Coons, T.A.; Rhodes, B.A.; Thakur, M.L.

    1991-01-01

    Acute infections, such as appendicitis and occult infections in AIDS patients, can be diagnosed within two hours by gamma scintigraphy after i.v. administration of {sup 99m}Tc labeled antibodies reactive with human granulocytes. The antibody, murine IgM anti-SSEA-1, is partially reduced using Sn(II) to expose and protect reactive sulfide groups. The antibody is then purified, stannous tartrate and stabilizers are added, and the mixture is lyophilized. To label, sodium pertechnetate is added. After a 15 minute incubation the tracer drug is injected. The rate of accumulation and degree of concentration at the site of infection is presumptively determinative of the severitymore » of the infection. Acceptance criteria and tests for the {sup 99m}Tc labeled antibody product have been established and validated. Greater than 93% of the {sup 99m}Tc is firmly bound to the protein as determined by quantitative HPLC. Radiochemical impurities, colloidal {sup 99m}Tc and free pertechnetate are together less than 4% as determined by thin layer chromatography. The immunoreactive fraction, measured by binding to solid phase antigen, and affinity measured be ELISA, are unchanged by the {sup 99m}Tc-direct labeling process. Two hour blood clearance in rats is within 90% of the value of the {sup 125}I labeled analog. The immunoreactive fraction decreases less than 10% when incubated in human plasma for 24 hours. This method has been compared to other direct labeling methods, and found to give higher radiochemical yields. 5 figs.« less

  19. Method for the production of .sup.99m Tc compositions from .sup.99 Mo-containing materials

    DOEpatents

    Bennett, Ralph G.; Christian, Jerry D.; Grover, S. Blaine; Petti, David A.; Terry, William K.; Yoon, Woo Y.

    1998-01-01

    An improved method for producing .sup.99m Tc compositions from .sup.99 Mo compounds. .sup.100 Mo metal or .sup.100 MoO.sub.3 is irradiated with photons in a particle (electron) accelerator to ultimately produce .sup.99 MoO.sub.3. This composition is then heated in a reaction chamber to form a pool of molten .sup.99 MoO.sub.3 with an optimum depth of 0.5-5 mm. A gaseous mixture thereafter evolves from the molten .sup.99 MoO.sub.3 which contains vaporized .sup.99 MoO.sub.3, vaporized .sup.99m TcO.sub.3, and vaporized .sup.99m TcO.sub.2. This mixture is then combined with an oxidizing gas (O.sub.2(g)) to generate a gaseous stream containing vaporized .sup.99m Tc.sub.2 O.sub.7 and vaporized .sup.99 MoO.sub.3. Next, the gaseous stream is cooled in a primary condensation stage in the reaction chamber to remove vaporized .sup.99 MoO.sub.3. Cooling is undertaken at a specially-controlled rate to achieve maximum separation efficiency. The gaseous stream is then cooled in a sequential secondary condensation stage to convert vaporized .sup.99m Tc.sub.2 O.sub.7 into a condensed .sup.99m Tc-containing reaction product which is collected.

  20. Method for the production of {sup 99m}Tc compositions from {sup 99}Mo-containing materials

    DOEpatents

    Bennett, R.G.; Christian, J.D.; Grover, S.B.; Petti, D.A.; Terry, W.K.; Yoon, W.Y.

    1998-09-01

    An improved method is described for producing {sup 99m}Tc compositions from {sup 99}Mo compounds. {sup 100}Mo metal or {sup 100}MoO{sub 3} is irradiated with photons in a particle (electron) accelerator to ultimately produce {sup 99}MoO{sub 3}. This composition is then heated in a reaction chamber to form a pool of molten {sup 99}MoO{sub 3} with an optimum depth of 0.5--5 mm. A gaseous mixture thereafter evolves from the molten {sup 99}MoO{sub 3} which contains vaporized {sup 99}MoO{sub 3}, vaporized {sup 99m}TcO{sub 3}, and vaporized {sup 99m}TcO{sub 2}. This mixture is then combined with an oxidizing gas (O{sub 2(g)}) to generate a gaseous stream containing vaporized {sup 99m}Tc{sub 2}O{sub 7} and vaporized {sup 99}MoO{sub 3}. Next, the gaseous stream is cooled in a primary condensation stage in the reaction chamber to remove vaporized {sup 99}MoO{sub 3}. Cooling is undertaken at a specially-controlled rate to achieve maximum separation efficiency. The gaseous stream is then cooled in a sequential secondary condensation stage to convert vaporized {sup 99m}Tc{sub 2}O{sub 7} into a condensed {sup 99m}Tc-containing reaction product which is collected. 1 fig.

  1. Detection of gastritis by /sup 99m/Tc-labeled red-blood-cell scintigraphy

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Wilton, G.P.; Wahl, R.L.; Juni, J.E.

    1984-10-01

    Gastritis is a common condition, with a variety of causes, that is diagnosed most often by barium upper gastrointestinal tract series or endoscopy. The authors report a case in which gastritis without active bleeding was apparent in scintiscans obtained during the evaluation of GI bleeding using /sup 99m/Tc-labeled red blood cells (TcRBC). The scintigraphic findings that suggest gastritis are described.

  2. Trypanosoma cruzi TcSMUG L-surface Mucins Promote Development and Infectivity in the Triatomine Vector Rhodnius prolixus

    PubMed Central

    Gonzalez, Marcelo S.; Souza, Marcela S.; Garcia, Eloi S.; Nogueira, Nadir F. S.; Mello, Cícero B.; Cánepa, Gaspar E.; Bertotti, Santiago; Durante, Ignacio M.; Azambuja, Patrícia; Buscaglia, Carlos A.

    2013-01-01

    Background TcSMUG L products were recently identified as novel mucin-type glycoconjugates restricted to the surface of insect-dwelling epimastigote forms of Trypanosoma cruzi, the etiological agent of Chagas disease. The remarkable conservation of their predicted mature N-terminal region, which is exposed to the extracellular milieu, suggests that TcSMUG L products may be involved in structural and/or functional aspects of the interaction with the insect vector. Methodology and Principal Findings Here, we investigated the putative roles of TcSMUG L mucins in both in vivo development and ex vivo attachment of epimastigotes to the luminal surface of the digestive tract of Rhodnius prolixus. Our results indicate that the exogenous addition of TcSMUG L N-terminal peptide, but not control T. cruzi mucin peptides, to the infected bloodmeal inhibited the development of parasites in R. prolixus in a dose-dependent manner. Pre-incubation of insect midguts with the TcSMUG L peptide impaired the ex vivo attachment of epimastigotes to the luminal surface epithelium, likely by competing out TcSMUG L binding sites on the luminal surface of the posterior midgut, as revealed by fluorescence microscopy. Conclusion and Significance Together, these observations indicate that TcSMUG L mucins are a determinant of both adhesion of T. cruzi epimastigotes to the posterior midgut epithelial cells of the triatomine, and the infection of the insect vector, R. prolixus. PMID:24244781

  3. Comparison of Biological Properties of 99mTc-Labeled Cyclic RGD Peptide Trimer and Dimer Useful as SPECT Radiotracers for Tumor Imaging

    PubMed Central

    Zhao, Zuo-Quan; Yang, Yong; Fang, Wei; Liu, Shuang

    2016-01-01

    Introduction This study sought to evaluate a 99mTc-labeled trimeric cyclic RGD peptide (99mTc-4P-RGD3) as the new radiotracer for tumor imaging. The objective was to compare its biological properties with those of 99mTc-3P-RGD2 in the same animal model. Methods HYNIC-4P-RGD3 was prepared by reacting 4P-RGD3 with excess HYNIC-OSu in the presence of diisopropylethylamine. 99mTc-4P-RGD3 was prepared using a kit formulation, and evaluated for its tumor-targeting capability and biodistribution properties in the BALB/c nude mice with U87MG human glioma xenografts. Planar and SPECT imaging studies were performed in athymic nude mice with U87MG glioma xenografts. For comparison purpose, 99mTc-3P-RGD2 (a αvβ3-targeted radiotracer currently under clinical evaluation for tumor imaging in cancer patients) was also evaluated in the same animal models. Blocking experiments were used to demonstrate the αvβ3 specificity of 99mTc-4P-RGD3. Results 99mTc-4P-RGD3 was prepared with >95% RCP and high specific activity (~200 GBq/µmol). 99mTc-4P-RGD3 and 99mTc-3P-RGD2 shared almost identical tumor uptake and similar biodistribution properties. 99mTc-4P-RGD3 had higher uptake than 99mTc-3P-RGD2 in the intestines and kidneys; but it showed better metabolic stability. The U87MG tumors were clearly visualized by SPECT with excellent contrast with 99mTc-4P-RGD3 and 99mTc-3P-RGD2. Conclusion Increasing peptide multiplicity from 3P-RGD2 to 4P-RGD3 offers no advantages with respect to the tumor-targeting capability. 99mTc-4P-RGD3 is as good a SPECT radiotracer as 99mTc-3P-RGD2 for imaging αvβ3-positive tumors. PMID:27556955

  4. 99mTc-zolmitriptan: radiolabeling, molecular modeling, biodistribution and gamma scintigraphy as a hopeful radiopharmaceutical for lung nuclear imaging.

    PubMed

    Rashed, H M; Marzook, F A; Farag, H

    2016-12-01

    Lung imaging radiopharmaceuticals are helpful agents for measuring pulmonary blood flow and allow detection of pulmonary embolism and lung cancer. The goal of this study was to develop a novel potential radiopharmaceutical for lung imaging. Zolmitriptan (a selective serotonin receptor agonist) was successfully labeled with 99m Tc via direct labeling method under reductive conditions studying different factors affecting the labeling efficiency. 99m Tc-zolmitriptan was obtained with a maximum labeling yield of 92.5 ± 0.61 % and in vitro stability up to 24 h. Molecular modeling was done to predict the structure of 99m Tc-zolmitriptan and ensure that radiolabeling did not affect binding ability of zolmitriptan to its receptor. Biodistribution studies showed that maximum lung uptake of 99m Tc-zolmitriptan was 23.89 ± 1.2 % injected dose/g tissue at 15 min post-injection and retention in lungs remained high up to 1 h, whereas the clearance from mice appeared to proceed mainly via the renal pathway. Scintigraphic images confirmed the biodistribution results showing a high resolution lung image with low accumulation of radioactivity in other organs except kidneys and urinary bladder. 99m Tc-zolmitriptan is not a blood product and so it is more safe than the currently available 99m Tc-MAA, and its lung uptake is higher than that of the recently discovered 123 I-IPMPD, 99m Tc(CO) 5 I and 99m Tc-DHPM. So, 99m Tc-zolmitriptan could be used as a hopeful radiopharmaceutical for lung scintigraphic imaging.

  5. Targeted disruption of TC-PTP in the proliferative compartment augments STAT3 and AKT signaling and skin tumor development.

    PubMed

    Lee, Hyunseung; Kim, Mihwa; Baek, Minwoo; Morales, Liza D; Jang, Ik-Soon; Slaga, Thomas J; DiGiovanni, John; Kim, Dae Joon

    2017-03-21

    Tyrosine phosphorylation is a vital mechanism that contributes to skin carcinogenesis. It is regulated by the counter-activities of protein tyrosine kinases (PTKs) and protein tyrosine phosphatases (PTPs). Here, we report the critical role of T-cell protein tyrosine phosphatase (TC-PTP), encoded by Ptpn2, in chemically-induced skin carcinogenesis via the negative regulation of STAT3 and AKT signaling. Using epidermal specific TC-PTP knockout (K14Cre.Ptpn2 fl/fl ) mice, we demonstrate loss of TC-PTP led to a desensitization to tumor initiator 7,12-dimethylbenz[a]anthracene (DMBA)-induced apoptosis both in vivo epidermis and in vitro keratinocytes. TC-PTP deficiency also resulted in a significant increase in epidermal thickness and hyperproliferation following exposure to the tumor promoter, 12-O-tetradecanoylphorbol-13-acetate (TPA). Western blot analysis showed that both phosphorylated STAT3 and phosphorylated AKT expressions were significantly increased in epidermis of TC-PTP-deficient mice compared to control mice following TPA treatment. Inhibition of STAT3 or AKT reversed the effects of TC-PTP deficiency on apoptosis and proliferation. Finally, TC-PTP knockout mice showed a shortened latency of tumorigenesis and significantly increased numbers of tumors during two-stage skin carcinogenesis. Our findings reveal that TC-PTP has potential as a novel target for the prevention of skin cancer through its role in the regulation of STAT3 and AKT signaling.

  6. Targeted disruption of TC-PTP in the proliferative compartment augments STAT3 and AKT signaling and skin tumor development

    PubMed Central

    Lee, Hyunseung; Kim, Mihwa; Baek, Minwoo; Morales, Liza D.; Jang, Ik-Soon; Slaga, Thomas J.; DiGiovanni, John; Kim, Dae Joon

    2017-01-01

    Tyrosine phosphorylation is a vital mechanism that contributes to skin carcinogenesis. It is regulated by the counter-activities of protein tyrosine kinases (PTKs) and protein tyrosine phosphatases (PTPs). Here, we report the critical role of T-cell protein tyrosine phosphatase (TC-PTP), encoded by Ptpn2, in chemically-induced skin carcinogenesis via the negative regulation of STAT3 and AKT signaling. Using epidermal specific TC-PTP knockout (K14Cre.Ptpn2fl/fl) mice, we demonstrate loss of TC-PTP led to a desensitization to tumor initiator 7,12-dimethylbenz[a]anthracene (DMBA)-induced apoptosis both in vivo epidermis and in vitro keratinocytes. TC-PTP deficiency also resulted in a significant increase in epidermal thickness and hyperproliferation following exposure to the tumor promoter, 12-O-tetradecanoylphorbol-13-acetate (TPA). Western blot analysis showed that both phosphorylated STAT3 and phosphorylated AKT expressions were significantly increased in epidermis of TC-PTP-deficient mice compared to control mice following TPA treatment. Inhibition of STAT3 or AKT reversed the effects of TC-PTP deficiency on apoptosis and proliferation. Finally, TC-PTP knockout mice showed a shortened latency of tumorigenesis and significantly increased numbers of tumors during two-stage skin carcinogenesis. Our findings reveal that TC-PTP has potential as a novel target for the prevention of skin cancer through its role in the regulation of STAT3 and AKT signaling. PMID:28322331

  7. Diagnostic value of 99mTc-ethambutol scintigraphy in tuberculosis: compared to microbiological and histopathological tests.

    PubMed

    Kartamihardja, A H S; Kurniawati, Y; Gunawan, R

    2018-01-01

    Tuberculosis (TB) still remains the world's endemic infection. TB affects the lungs and any part of the body other than the lung. The diagnosis of TB has not changed much over the decades. Ethambutol is one of the first line treatments for TB. It can be labeled using 99m Tc. 99m Tc-ethambutol will be accumulated in the site of TB lesion and can be imaged using gamma camera. The aim of this study was to evaluate the diagnostic value of 99m Tc-ethambutol scintigraphy in detecting and localizing of TB. Retrospective cross-sectional study was done. Subjects were patients suspected of having TB infection. Whole body and SPECT-CT imaging at the suspected area was done 1 and 4 h after injection of 370-555 MBq 99m Tc-ethambutol. 99m Tc-ethambutol scintigraphy was analyzed visually. The results were compared with that of histopathological or microbiological tests. Statistical analysis was done to determine the sensitivity, specificity, PPV, NPV and accuracy. One hundred and sixty-eight subjects were involved in this study. There were 110 men and 58 women with mean age of 34.52 ± 11.94 years. There were concordance results in 156 (92.86%) and discordant in 12 (7.14%) subjects between 99m Tc-ethambutol scintigraphy and histopathological or microbiological result. The sensitivity, specificity, PPV, NPV and accuracy of 99m Tc-ethambutol scintigraphy in the diagnosis of pulmonary TB were 93.9, 85.7, 93.9, 85.7 and 91.4%, respectively, for extra-pulmonary TB 95.5, 77.8, 97.9, 63.6, and 85.1%, respectively, and for total tuberculosis 94.9, 83.3, 96.3, 78.1 and 92.8%, respectively. There was no side effect observed in this study. 99m Tc-ethambutol scintigraphy is a useful diagnostic imaging technique to detect and localize intra- and extra-pulmonary TB. It is safe to be performed even in pediatric patient. Consuming ethambutol less than 2 weeks did not influence the result.

  8. Imaging of Herniated Discs of the Cervical Spine: Inter-Modality Differences between 64-Slice Multidetector CT and 1.5-T MRI

    PubMed Central

    Yi, Ji Sook; Han, Jong Kyu; Kim, Hyun-Joo

    2015-01-01

    Objective To assess inter-modality variability when evaluating cervical intervertebral disc herniation using 64-slice multidetector-row computed tomography (MDCT) and magnetic resonance imaging (MRI). Materials and Methods Three musculoskeletal radiologists independently reviewed cervical spine 1.5-T MRI and 64-slice MDCT data on C2-3 though C6-7 of 51 patients in the context of intervertebral disc herniation. Interobserver and inter-modality agreements were expressed as unweighted kappa values. Weighted kappa statistics were used to assess the extents of agreement in terms of the number of involved segments (NIS) in disc herniation and epicenter measurements collected using MDCT and MRI. Results The interobserver agreement rates upon evaluation of disc morphology by the three radiologists were in fair to moderate agreement (k = 0.39-0.53 for MDCT images; k = 0.45-0.56 for MRIs). When the disc morphology was categorized into two and four grades, the inter-modality agreement rates were moderate (k-value, 0.59) and substantial (k-value, 0.66), respectively. The inter-modality agreements for evaluations of the NIS (k-value, 0.78) and the epicenter (k-value, 0.79) were substantial. Also, the interobserver agreements for the NIS (CT; k-value, 0.85 and MRI; k-value, 0.88) and epicenter (CT; k-value, 0.74 and MRI; k-value, 0.70) evaluations by two readers were substantial. MDCT tended to underestimate the extent of herniated disc lesions compared with MRI. Conclusion Multidetector-row computed tomography and MRI showed a moderate-to-substantial degree of inter-modality agreement for the assessment of herniated cervical discs. MDCT images have a tendency to underestimate the anterior/posterior extent of the herniated disc compared with MRI. PMID:26175589

  9. NMR/MRI with hyperpolarized gas and high Tc SQUID

    DOEpatents

    Schlenga, Klaus; de Souza, Ricardo E.; Wong-Foy, Annjoe; Clarke, John; Pines, Alexander

    2000-01-01

    A method and apparatus for the detection of nuclear magnetic resonance (NMR) signals and production of magnetic resonance imaging (MRI) from samples combines the use of hyperpolarized inert gases to enhance the NMR signals from target nuclei in a sample and a high critical temperature (Tc) superconducting quantum interference device (SQUID) to detect the NMR signals. The system operates in static magnetic fields of 3 mT or less (down to 0.1 mT), and at temperatures from liquid nitrogen (77K) to room temperature. Sample size is limited only by the size of the magnetic field coils and not by the detector. The detector is a high Tc SQUID magnetometer designed so that the SQUID detector can be very close to the sample, which can be at room temperature.

  10. Role of 99mTc-ECD SPECT in the Management of Children with Craniosynostosis

    PubMed Central

    Barik, Mayadhar; Bajpai, Minu; Das, Rashmi Ranajn; Malhotra, Arun; Panda, Shasanka Shekhar; Sahoo, Manas Kumar; Dwivedi, Sadanand

    2014-01-01

    Purpose of the Report. There is a paucity of data on correlation of various imaging modalities with clinical findings in craniosynostosis. Moreover, no study has specifically reported the role of 99mTc-ECD SPECT in a large number of subjects with craniosynostosis. Materials and Methods. We prospectively analyzed a cohort of 85 patients with craniosynostosis from year 2007 to 2012. All patients underwent evaluation with 99mTc-ECD SPECT and the results were correlated with radiological and surgical findings. Results. 99mTc-ECD SPECT revealed regional perfusion abnormalities in the cerebral hemisphere corresponding to the fused sutures preoperatively that disappeared postoperatively in all the cases. Corresponding to this, the mean mental performance quotient (MPQ) increased significantly (P < 0.05) postoperatively only in those children with absent perfusion defect postoperatively. Conclusions. Our study suggests that early surgery and release of craniosynostosis in patients with preoperative perfusion defects (absent on 99mTc-ECD SPECT study) are beneficial, as theylead to improved MPQ after surgery. PMID:24987670

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

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Benko, Heather

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

  12. Development and study of 99mTc-1-Thio-D-glucose for visualization of malignant tumors

    NASA Astrophysics Data System (ADS)

    Zeltchan, R.; Medvedeva, A.; Sinilkin, I.; Bragina, O.; Chernov, V.; Stasyuk, E.; Rogov, A.; Il'ina, E.; Skuridin, V.

    2017-09-01

    The preclinical studies of 99mTc-1-Thio-D-glucose, a new tumor-seeking agent based on technetium-99m-labeled glucose derivative, were conducted, and the feasibility of using this radiopharmaceutical for tumor visualization was studied. The preclinical studies were carried out strictly in accordance with the local legislation and were regulated by the generally accepted research standards. 99mTc-1-Thio-D-glucose was found to have optimal pharmacokinetic and physico-chemical properties for diagnostic imaging and was proved to belong to the low-toxic substances. The potential utility of 99mTc-1-thio-D-glucose for tumor imaging was studied in vitro and in vivo models. The present study demonstrated that 99mTc-1-Thio-D-glucose is a prospective radiopharmaceutical for cancer visualization.

  13. 99mTc Labeled Glucagon-Like Peptide-1-Analogue (99mTc-GLP1) Scintigraphy in the Management of Patients with Occult Insulinoma

    PubMed Central

    Sowa-Staszczak, Anna; Trofimiuk-Müldner, Małgorzata; Stefańska, Agnieszka; Tomaszuk, Monika; Buziak-Bereza, Monika; Gilis-Januszewska, Aleksandra; Jabrocka-Hybel, Agata; Głowa, Bogusław; Małecki, Maciej; Bednarczuk, Tomasz; Kamiński, Grzegorz; Kowalska, Aldona; Mikołajczak, Renata; Janota, Barbara; Hubalewska-Dydejczyk, Alicja

    2016-01-01

    Introduction The aim of this study was to assess the utility of [Lys40(Ahx-HYNIC-99mTc/EDDA)NH2]-exendin-4 scintigraphy in the management of patients with hypoglycemia, particularly in the detection of occult insulinoma. Materials and Methods Forty patients with hypoglycemia and increased/confusing results of serum insulin and C-peptide concentration and negative/inconclusive results of other imaging examinations were enrolled in the study. In all patients GLP-1 receptor imaging was performed to localise potential pancreatic lesions. Results Positive results of GLP-1 scintigraphy were observed in 28 patients. In 18 patients postsurgical histopathological examination confirmed diagnosis of insulinoma. Two patients had contraindications to the surgery, one patient did not want to be operated. One patient, who presented with postprandial hypoglycemia, with positive result of GLP-1 imaging was not qualified for surgery and is in the observational group. Eight patients were lost for follow up, among them 6 patients with positive GLP-1 scintigraphy result. One patient with negative scintigraphy was diagnosed with malignant insulinoma. In two patients with negative scintigraphy Munchausen syndrome was diagnosed (patients were taking insulin). Other seven patients with negative results of 99mTcGLP-1 scintigraphy and postprandial hypoglycemia with C-peptide and insulin levels within the limits of normal ranges are in the observational group. We would like to mention that 99mTc-GLP1-SPECT/CT was also performed in 3 pts with nesidioblastosis (revealing diffuse tracer uptake in two and a focal lesion in one case) and in two patients with malignant insulinoma (with the a focal uptake in the localization of a removed pancreatic headin one case and negative GLP-1 1 scintigraphy in the other patient). Conclusions 99mTc-GLP1-SPECT/CT could be helpful examination in the management of patients with hypoglycemia enabling proper localization of the pancreatic lesion and effective

  14. Safety of multidetector computed tomography pulmonary angiography to exclude pulmonary embolism in patients with a likely pretest clinical probability.

    PubMed

    Robert-Ebadi, H; Glauser, F; Planquette, B; Moumneh, T; Le Gal, G; Righini, M

    2017-08-01

    Essentials Safety of computed tomography (CTPA) to exclude pulmonary embolism (PE) in all patients is debated. We analysed the outcome of PE-likely outpatients left untreated after negative CTPA alone. The 3-month venous thromboembolic risk in these patients was very low (0.6%; 95% CI 0.2-2.3). Multidetector CTPA alone safely excludes PE in patients with likely clinical probability. Background In patients with suspected pulmonary embolism (PE) classified as having a likely or high pretest clinical probability, the need to perform additional testing after a negative multidetector computed tomography pulmonary angiography (CTPA) finding remains a matter of debate. Objectives To assess the safety of excluding PE by CTPA without additional imaging in patients with a likely pretest probability of PE. Patients/Methods We retrospectively analyzed patients included in two multicenter management outcome studies that assessed diagnostic algorithms for PE diagnosis. Results Two thousand five hundred and twenty-two outpatients with suspected PE were available for analysis. Of these 2522 patients, 845 had a likely clinical probability as assessed by use of the simplified revised Geneva score. Of all of these patients, 314 had the diagnosis of PE excluded by a negative CTPA finding alone without additional testing, and were left without anticoagulant treatment and followed up for 3 months. Two patients presented with a venous thromboembolism (VTE) during follow-up. Therefore, the 3-month VTE risk in likely-probability patients after a negative CTPA finding alone was 2/314 (0.6%; 95% confidence interval [CI] 0.2-2.3%). Conclusions In outpatients with suspected PE and a likely clinical probability as assessed by use of the simplified revised Geneva score, CTPA alone seems to be able to safely exclude PE, with a low 3-month VTE rate, which is similar to the VTE rate following the gold standard, i.e. pulmonary angiography. © 2017 International Society on Thrombosis and Haemostasis.

  15. Microstructural characterization and tribological behavior of surface plasma Zr-Er alloying on TC11 alloy

    NASA Astrophysics Data System (ADS)

    Wei, Dongbo; Zhang, Pingze; Liu, Yingchao; Chen, Xiaohu; Ding, Feng; Li, Fengkun

    2018-02-01

    The Zr coating and Zr-Er coating are grown on TC11 substrate by double-glow plasma surface metallurgy technique, followed by the wear tests at ambient temperature and 500 °C. The data of nanohardness and elastic modulus of the samples are collected by the nano-indentation test. The adhesion strength of coatings is investigated by means of the scratch test. The study of wear resistance is performed using a ball-on-disc wear test system by running against the Si3N4 ball and measured by scanning electron microscope (SEM) and X-ray diffraction (XRD). Experimental results indicate that the nanohardness of the Zr coating and Zr-Er coating are 5.94 GPa and 7.98 GPa, respectively, which are 1.79 times and 2.41 times greater than that of TC11 substrate. Zr coating and Zr-Er coating realize the metallurgical bonding with TC11 substrate with continuous and compact structure. Compared with the Zr coating and TC11, the Zr-Er coating presents the lowest specific wear rates, which are 1.689 × 10-6 mm3 Nm-1 and 1.851 × 10-6 mm3 Nm-1 at ambient temperature and 500 °C respectively, indicating the excellent and improved wear resistance of TC11.

  16. Tc depression and superconductor-insulator transition in molybdenum nitride thin films

    NASA Astrophysics Data System (ADS)

    Ichikawa, F.; Makise, K.; Tsuneoka, T.; Maeda, S.; Shinozaki, B.

    2018-03-01

    We have studied that the Tc depression and the superconductor-insulator transition (SIT) in molybdenum nitride (MoN) thin films. Thin films were fabricated by reactive DC magnetron sputtering method onto (100) MgO substrates in the mixture of Ar and N2 gases. Several dozen MoN thin films were prepared in the range of 3 nm < thickness d < 60 nm. The resistance was measured by a DC four-probe technique. It is found that Tc decreases from 6.6 K for thick films with increase of the normal state sheet resistance {R}{{sq}}{{N}} and experimental data were fitted to the Finkel’stein formula using the bulk superconducting transition temperature Tc 0 = 6.45 K and the elastic scattering time of electron τ = 1.6 × 10‑16 s. From this analysis the critical sheet resistance Rc is found about 2 kΩ, which is smaller than the quantum sheet resistance R Q. This value of Rc is almost the same as those for 2D NbN films. The value of τ for MoN films is also the similar value for NbN films 1.0 × 10‑16 s, while Tc 0 is different from that for NbN films 14.85 K. It is indicated that the mechanism of SIT for MoN films is similar to that of NbN films, while the mean free path ℓ for MoN films is larger than that for NbN films.

  17. Evaluation of hepatic arterial anatomy by multidetector computed tomographic angiography in living donor liver transplantation.

    PubMed

    Keles, Papatya; Yuce, Ihsan; Keles, Sait; Kantarci, Mecit

    2016-06-01

    The aim of this study was to define the different courses and percentages of hepatic artery that were detected during preoperative evaluation of living liver donors by multidetector computed tomographic angiography (MDCTA). We evaluated 150 donors before hepatic transplantation. All of the donors were evaluated by multislice CT scan with 256 detectors. For each patient, arterial, portal and venous phase images were obtained. The hepatic arterial variations were evaluated by the same radiologist according to Michels' classification. Common hepatic arterial anatomy (type I) was observed in 95 donors (63.3%). Other arterial variations were determined in the remaining 55 donors (36.6%). The second common variation was type XI which did not match with the description of Michels' classification variation in 15 donors (10%). The remaining variations described in Michels' classification were seen at lower rates. Type VII or X variation was not seen. MDCTA is a useful method to identify the blood supply of the liver before the liver transplantations, and surgeons can make their plan on the basis of CT data.

  18. Carotid stenosis assessment with multi-detector CT angiography: comparison between manual and automatic segmentation methods.

    PubMed

    Zhu, Chengcheng; Patterson, Andrew J; Thomas, Owen M; Sadat, Umar; Graves, Martin J; Gillard, Jonathan H

    2013-04-01

    Luminal stenosis is used for selecting the optimal management strategy for patients with carotid artery disease. The aim of this study is to evaluate the reproducibility of carotid stenosis quantification using manual and automated segmentation methods using submillimeter through-plane resolution Multi-Detector CT angiography (MDCTA). 35 patients having carotid artery disease with >30 % luminal stenosis as identified by carotid duplex imaging underwent contrast enhanced MDCTA. Two experienced CT readers quantified carotid stenosis from axial source images, reconstructed maximum intensity projection (MIP) and 3D-carotid geometry which was automatically segmented by an open-source toolkit (Vascular Modelling Toolkit, VMTK) using NASCET criteria. Good agreement among the measurement using axial images, MIP and automatic segmentation was observed. Automatic segmentation methods show better inter-observer agreement between the readers (intra-class correlation coefficient (ICC): 0.99 for diameter stenosis measurement) than manual measurement of axial (ICC = 0.82) and MIP (ICC = 0.86) images. Carotid stenosis quantification using an automatic segmentation method has higher reproducibility compared with manual methods.

  19. Standardization of Assistive Products with Robotic Technology - From a Perspective of ISO/TC173.

    PubMed

    Inoue, Takenobu; Yamauchi, Shigeru; Westman, Karl-Erik

    2017-01-01

    ISO/TC173 is a technical committee, in charge of international standardization of assistive products (APs). Robotic technology (RT) is currently an important topic in this field. APs with RT will be included in future revisions of the scope of TC173. Cooperation between the AP and RT space is essential to reach suitable solutions of future standardization.

  20. 99mTc-HYNIC-TOC imaging in the evaluation of pancreatic masses which are potential neuroendocrine tumors.

    PubMed

    Qiao, Zhen; Zhang, Jingjing; Jin, Xiaona; Huo, Li; Zhu, Zhaohui; Xing, Haiqun; Li, Fang

    2015-05-01

    The aim of this investigation was to determine the accuracy of the findings and the diagnoses of Tc-hydrazinonicotinyl-Tyr3-octreotide scan (Tc-HYNIC-TOC imaging) in patients with pancreatic masses which were potential neuroendocrine tumors. Records of total 20 patients with pancreatic masses were retrospectively reviewed. All of the patients had been revealed by abdominal contrast CT and possibility of neuroendocrine tumors could not be excluded by CT imaging before Tc-HYNIC-TOC imaging. Tc-HYNIC-TOC imaging was performed at 1 and 4 hours post-tracer injection, and SPECT/CT images of the abdomen were also acquired. The image findings were compared to final diagnoses which were made from pathological examination. Among all 20 pancreatic masses evaluated, there were 16 malignant lesions which included 1 ductal adenocarcinoma and 15 neuroendocrine tumors. Tc-HYNIC-TOC imaging identified 14 of 15 pancreatic neuroendocrine tumors and excluded 4 of 5 lesions which were not neuroendocrine tumors. The overall sensitivity, specificity, and accuracy was therefore 93.3% (14 of 15), 80% (4 of 5), and 90.0% (18 of 20), respectively, in our patient population. Tc-HYNIC-TOC imaging provides reasonable accuracy in the evaluation pancreatic mass suspected to be neuroendocrine tumors.

  1. Multi-detector CT features of acute intestinal ischemia and their prognostic correlations.

    PubMed

    Moschetta, Marco; Telegrafo, Michele; Rella, Leonarda; Stabile Ianora, Amato Antonio; Angelelli, Giuseppe

    2014-05-28

    Acute intestinal ischemia is an abdominal emergency occurring in nearly 1% of patients presenting with acute abdomen. The causes can be occlusive or non occlusive. Early diagnosis is important to improve survival rates. In most cases of late or missed diagnosis, the mortality rate from intestinal infarction is very high, with a reported value ranging from 60% to 90%. Multi-detector computed tomography (MDCT) is a fundamental imaging technique that must be promptly performed in all patients with suspected bowel ischemia. Thanks to the new dedicated reconstruction program, its diagnostic potential is much improved compared to the past and currently it is superior to that of any other noninvasive technique. The increased spatial and temporal resolution, high-quality multi-planar reconstructions, maximum intensity projections, vessel probe, surface-shaded volume rending and tissue transition projections make MDCT the gold standard for the diagnosis of intestinal ischemia, with reported sensitivity, specificity, positive and negative predictive values of 64%-93%, 92%-100%, 90%-100% and 94%-98%, respectively. MDCT contributes to appropriate treatment planning and provides important prognostic information thanks to its ability to define the nature and extent of the disease. The purpose of this review is to examine the diagnostic and prognostic role of MDCT in bowel ischemia with special regard to the state of art new reconstruction software.

  2. Non-perforated peptic ulcer disease: multidetector CT findings, complications, and differential diagnosis.

    PubMed

    Tonolini, Massimo; Ierardi, Anna Maria; Bracchi, Elena; Magistrelli, Paolo; Vella, Adriana; Carrafiello, Gianpaolo

    2017-10-01

    Despite availability of effective therapies, peptic ulcer disease (PUD) remains a major global disease, resulting from a combination of persistent Helicobacter pylori infection and widespread use of nonsteroidal anti-inflammatory drugs. Albeit endoscopy definitely represents the mainstay diagnostic technique, patients presenting to emergency departments with unexplained abdominal pain generally undergo multidetector CT as an initial investigation. Although superficial ulcers generally remain inconspicuous, careful multiplanar CT interpretation may allow to detect deep ulcers, secondary mural and extraluminal signs of peptic gastroduodenitis, thereby allowing timely endoscopic verification and appropriate treatment. This pictorial essay aims to provide radiologists with an increased familiarity with CT diagnosis of non-perforated PUD, with emphasis on differential diagnosis. Following an overview of current disease epidemiology and complications, it explains the appropriate CT acquisition and interpretation techniques, and reviews with several examples the cross-sectional findings of uncomplicated PUD. Afterwards, the CT features of PUD complications such as ulcer haemorrhage, gastric outlet obstruction, biliary and pancreatic fistulisation are presented. • Gastric and duodenal peptic ulcers are increasingly caused by nonsteroidal anti-inflammatory drugs • Multiplanar CT interpretation allows detecting deep ulcers and secondary signs of gastroduodenitis • CT diagnosis of uncomplicated peptic disease relies on direct and indirect signs • Currently the commonest complication, haemorrhage may be treated with transarterial embolisation • Other uncommon complications include gastric outlet obstruction and biliopancreatic fistulisation.

  3. Development of a Trypanosoma cruzi strain typing assay using MS2 peptide spectral libraries (Tc-STAMS2)

    PubMed Central

    de Oliveira, Gilberto Santos; Kawahara, Rebeca; Rosa-Fernandes, Livia; Avila, Carla Cristi; Teixeira, Marta M. G.; Larsen, Martin R.

    2018-01-01

    Background Chagas disease also known as American trypanosomiasis is caused by the protozoan Trypanosoma cruzi. Over the last 30 years, Chagas disease has expanded from a neglected parasitic infection of the rural population to an urbanized chronic disease, becoming a potentially emergent global health problem. T. cruzi strains were assigned to seven genetic groups (TcI-TcVI and TcBat), named discrete typing units (DTUs), which represent a set of isolates that differ in virulence, pathogenicity and immunological features. Indeed, diverse clinical manifestations (from asymptomatic to highly severe disease) have been attempted to be related to T.cruzi genetic variability. Due to that, several DTU typing methods have been introduced. Each method has its own advantages and drawbacks such as high complexity and analysis time and all of them are based on genetic signatures. Recently, a novel method discriminated bacterial strains using a peptide identification-free, genome sequence-independent shotgun proteomics workflow. Here, we aimed to develop a Trypanosoma cruzi Strain Typing Assay using MS/MS peptide spectral libraries, named Tc-STAMS2. Methods/Principal findings The Tc-STAMS2 method uses shotgun proteomics combined with spectral library search to assign and discriminate T. cruzi strains independently on the genome knowledge. The method is based on the construction of a library of MS/MS peptide spectra built using genotyped T. cruzi reference strains. For identification, the MS/MS peptide spectra of unknown T. cruzi cells are identified using the spectral matching algorithm SpectraST. The Tc-STAMS2 method allowed correct identification of all DTUs with high confidence. The method was robust towards different sample preparations, length of chromatographic gradients and fragmentation techniques. Moreover, a pilot inter-laboratory study showed the applicability to different MS platforms. Conclusions and significance This is the first study that develops a MS

  4. Development of a Trypanosoma cruzi strain typing assay using MS2 peptide spectral libraries (Tc-STAMS2).

    PubMed

    de Oliveira, Gilberto Santos; Kawahara, Rebeca; Rosa-Fernandes, Livia; Mule, Simon Ngao; Avila, Carla Cristi; Teixeira, Marta M G; Larsen, Martin R; Palmisano, Giuseppe

    2018-04-01

    Chagas disease also known as American trypanosomiasis is caused by the protozoan Trypanosoma cruzi. Over the last 30 years, Chagas disease has expanded from a neglected parasitic infection of the rural population to an urbanized chronic disease, becoming a potentially emergent global health problem. T. cruzi strains were assigned to seven genetic groups (TcI-TcVI and TcBat), named discrete typing units (DTUs), which represent a set of isolates that differ in virulence, pathogenicity and immunological features. Indeed, diverse clinical manifestations (from asymptomatic to highly severe disease) have been attempted to be related to T.cruzi genetic variability. Due to that, several DTU typing methods have been introduced. Each method has its own advantages and drawbacks such as high complexity and analysis time and all of them are based on genetic signatures. Recently, a novel method discriminated bacterial strains using a peptide identification-free, genome sequence-independent shotgun proteomics workflow. Here, we aimed to develop a Trypanosoma cruzi Strain Typing Assay using MS/MS peptide spectral libraries, named Tc-STAMS2. The Tc-STAMS2 method uses shotgun proteomics combined with spectral library search to assign and discriminate T. cruzi strains independently on the genome knowledge. The method is based on the construction of a library of MS/MS peptide spectra built using genotyped T. cruzi reference strains. For identification, the MS/MS peptide spectra of unknown T. cruzi cells are identified using the spectral matching algorithm SpectraST. The Tc-STAMS2 method allowed correct identification of all DTUs with high confidence. The method was robust towards different sample preparations, length of chromatographic gradients and fragmentation techniques. Moreover, a pilot inter-laboratory study showed the applicability to different MS platforms. This is the first study that develops a MS-based platform for T. cruzi strain typing. Indeed, the Tc-STAMS2 method

  5. Pixelized Measurement of (99m)Tc-HDP Micro Particles Formed in Gamma Correction Phantom Pinhole Scan: a Reference Study.

    PubMed

    Jung, Joo-Young; Cheon, Gi Jeong; Lee, Yun-Sang; Ha, Seunggyun; Chae, Mi-Hye; Chung, Yong-An; Yoon, Do Kyun; Bahk, Yong-Whee

    2016-09-01

    Currently, traumatic bone diseases are diagnosed by assessing the micro (99m)Tc-hydroxymethylene diphosphonate (HDP) uptake in injured trabeculae with ongoing osteoneogenesis demonstrated by gamma correction pinhole scan (GCPS). However, the mathematic size quantification of micro-uptake is not yet available. We designed and performed this phantom-based study to set up an in-vitro model of the mathematical calculation of micro-uptake by the pixelized measurement. The micro (99m)Tc-HDP deposits used in this study were spontaneously formed both in a large standard flood and small house-made dish phantoms. The processing was as follows: first, phantoms were flooded with distilled water and (99m)Tc-HDP was therein injected to induce micro (99m)Tc-HDP deposition; second, the deposits were scanned using parallel-hole and pinhole collimator to generally survey (99m)Tc-HDP deposition pattern; and third, the scans underwent gamma correction (GC) to discern individual deposits for size measurement. In original naïve scans, tracer distribution was simply nebulous in appearance and, hence, could not be measured. Impressively, however, GCPS could discern individual micro deposits so that they were calculated by pixelized measurement. Phantoms naturally formed micro (99m)Tc-HDP deposits that are analogous to (99m)Tc-HDP uptake on in-vivo bone scan. The smallest one we measured was 0.414 mm. Flooded phantoms and therein injected (99m)Tc-HDP form nebulous micro (99m)Tc-HDP deposits that are rendered discernible by GCPB and precisely calculable using pixelized measurement. This method can be used for precise quantitative and qualitative diagnosis of bone and joint diseases at the trabecular level.

  6. Evaluation of cardiovascular anomalies in patients with asymptomatic turner syndrome using multidetector computed tomography.

    PubMed

    Lee, Sun Hee; Jung, Ji Mi; Song, Min Seob; Choi, Seok jin; Chung, Woo Yeong

    2013-08-01

    Turner syndrome is well known to be associated with significant cardiovascular abnormalities. This paper studied the incidence of cardiovascular abnormalities in asymptomatic adolescent patients with Turner syndrome using multidetector computed tomography (MDCT) instead of echocardiography. Twenty subjects diagnosed with Turner syndrome who had no cardiac symptoms were included. Blood pressure and electrocardiography (ECG) was checked. Cardiovascular abnormalities were checked by MDCT. According to the ECG results, 11 had a prolonged QTc interval, 5 had a posterior fascicular block, 3 had a ventricular conduction disorder. MDCT revealed vascular abnormalities in 13 patients (65%). Three patients had an aberrant right subclavian artery, 2 had dilatation of left subclavian artery, and others had an aortic root dilatation, aortic diverticulum, and abnormal left vertebral artery. As for venous abnormalities, 3 patients had partial anomalous pulmonary venous return and 2 had a persistent left superior vena cava. This study found cardiovascular abnormalities in 65% of asymptomatic Turner syndrome patients using MDCT. Even though, there are no cardiac symptoms in Turner syndrome patients, a complete evaluation of the heart with echocardiography or MDCT at transition period to adults must be performed.

  7. Radiolabeling of rituximab with (188)Re and (99m)Tc using the tricarbonyl technology.

    PubMed

    Dias, Carla Roberta; Jeger, Simone; Osso, João Alberto; Müller, Cristina; De Pasquale, Christine; Hohn, Alexander; Waibel, Robert; Schibli, Roger

    2011-01-01

    The most successful clinical studies of immunotherapy in patients with non-Hodgkin's lymphoma (NHL) use the antibody rituximab (RTX) targeting CD20(+) B-cell tumors. Rituximab radiolabeled with β(-) 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 (99m)Tc- and (188)Re-tricarbonyl core (IsoLink technology). The native format of the antibody (RTX(wt)) as well as a reduced form (RTX(red)) was labeled with (99m)Tc/(188)Re(CO)(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. The radiolabeling efficiency and kinetics of RTX(red) were superior to that of RTX(wt) ((99m)Tc: 98% after 3 h for RTX(red) vs. 70% after 24 h for RTX(wt)). (99m)Tc(CO)(3)-RTX(red) was used without purification for in vitro and in vivo studies whereas (188)Re(CO)(3)-RTX(red) was purified to eliminate free (188)Re-precursor. Both radioimmunoconjugates were stable in human plasma for 24 h at 37 °C. In contrast, displacement experiments with excess cysteine/histidine showed significant transchelation in the case of (99m)Tc(CO)(3)-RTX(red) but not with pre-purified (188)Re(CO)(3)-RTX(red). Both conjugates revealed high binding affinity to the CD20 antigen (K(d) = 5-6 nM). Tumor uptake of (188)Re(CO)(3)-RTX(red) was 2.5 %ID/g and 0.8 %ID/g for (99m)Tc(CO)(3)-RTX(red) 48 h after injection. The values for other organs and tissues were similar for both compounds, for example the tumor-to-blood and tumor-to-liver ratios were 0.4 and 0.3 for (99m)Tc(CO)(3)-RTX(red) and for (188)Re(CO)(3)-RTX

  8. Somatostatin receptor scintigraphy using 99mTc-EDDA/HYNIC-TOC in patients with medullary thyroid carcinoma.

    PubMed

    Czepczyński, Rafał; Parisella, Maria Gemma; Kosowicz, Jerzy; Mikołajczak, Renata; Ziemnicka, Katarzyna; Gryczyńska, Maria; Sowiński, Jerzy; Signore, Alberto

    2007-10-01

    Several new somatostatin analogues have been developed for the diagnosis and therapy of different tumours. Since somatostatin receptors are often over-expressed in medullary thyroid carcinoma (MTC), the aim of our study was to evaluate the utility of scintigraphy with the somatostatin analogue (99m)Tc-EDDA/HYNIC-TOC in MTC in comparison with other diagnostic techniques. Forty-five patients with MTC, aged 14-83 years, were investigated. Scintigraphy using (99m)Tc-EDDA/HYNIC-TOC (Tektrotyd) was performed 2 and 4 h post injection of 740 MBq (20 mCi) of the tracer. Other imaging techniques were also applied and analysed in individual cases (ultrasonography, computed tomography, (99m)Tc(V)-DMSA, (131)I-MIBG, (99m)Tc-MDP, (111)In-DTPA-octreotide and (18)F-FDG-PET) and compared with (99m)Tc-EDDA/HYNIC-TOC. In group 1 (eight patients before thyroidectomy), uptake of the tracer was found in the primary tumours. In group 2 (six patients with remission), a false positive result was found in one patient; in the remaining five patients, no pathological foci were visualised. In group 3 (31 patients with post-surgical hypercalcitoninaemia), scintigraphy was true positive in 23 patients (74.2%): uptake in the thyroid bed was found in five patients, in the lymph nodes in 18 and in bone metastases in four. Using (99m)Tc-EDDA/HYNIC-TOC scintigraphy, the overall sensitivity was 79.5%, specificity 83.3%, accuracy 80.0%, positive predictive value 96.9% and negative predictive value 38.5%. (99m)Tc-EDDA/HYNIC-TOC is clinically useful for scintigraphy in the follow-up of patients with MTC. It can be used in clinical practice for preoperative evaluation, for localisation of local recurrence or distant metastases and particularly for therapy decision making.

  9. 99mTc-HYNIC-(tricine/EDDA)-FROP peptide for MCF-7 breast tumor targeting and imaging.

    PubMed

    Ahmadpour, Sajjad; Noaparast, Zohreh; Abedi, Seyed Mohammad; Hosseinimehr, Seyed Jalal

    2018-02-19

    Breast cancer is the most common malignancy among women in the world. Development of novel tumor-specific radiopharmaceuticals for early breast tumor diagnosis is highly desirable. In this study we developed 99m Tc-HYNIC-(tricine/EDDA)-Lys-FROP peptide with the ability of specific binding to MCF-7 breast tumor. The FROP-1 peptide was conjugated with the bifunctional chelator hydrazinonicotinamide (HYNIC) and labeled with 99m Tc using tricine/EDDA co-ligand. The cellular specific binding of 99m Tc-HYNIC-FROP was evaluated on different cell lines as well as with blocking experiment on MCF-7 (human breast adenocarcinoma). The tumor targeting and imaging of this labeled peptide were performed on MCF-7 tumor bearing mice. Radiochemical purity for 99m Tc-HYNIC-(tricine/EDDA)-FROP was 99% which was determined with ITLC method. This radiolabeled peptide showed high stability in normal saline and serum about 98% which was monitored with HPLC method. In saturation binding experiments, the binding constant (K d ) to MCF-7 cells was determined to be 158 nM. Biodistribution results revealed that the 99m Tc-HYNIC-FROP was mainly exerted from urinary route. The maximum tumor uptake was found after 30 min post injection (p.i.); however maximum tumor/muscle ratio was seen at 15 min p.i. The tumor uptake of this labeled peptide was specific and blocked by co-injection of excess FROP. According to the planar gamma imaging result, tumor was clearly visible due to the tumor uptake of 99m Tc-HYNIC-(tricine/EDDA)-FROP in mouse after 15 min p.i. The 99m Tc-HYNIC-(tricine/EDDA)-FROP is considered a promising probe with high specific binding to MCF-7 breast cancer cells.

  10. Effect of ketamine, pentobarbital, and morphine on Tc-99m-DISIDA hepatobiliary kinetics

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Durakovic, A.; Dubois, A.

    1985-05-01

    The purpose of this study was to evaluate hapatobiliary kinetics of Tc-99m-DISIDA in dogs after administration of anesthetic sedative or narcotic agents. Four groups of six male Beagle dogs were studied as a non-treated control group and after parenteral administration of ketamine (30 mg/kg IM), pentobarbital (25 mg/kg IV) or morphine (1 mg/kg IV). Each animal was injected with 4 mCi Tc-99m-DISIDA and hepatobiliary scintigraphic studies were obtained using a gamma camera with parallel hole multipurpose collimator and an A/sup 3/ MDS computer. The authors determined; peak activity of Tc-99m-DISIDA in the liver, visualization and peak activity of gallbladder, andmore » intestinal visualization of Tc-99m-DISIDA. Total bilirubin, LDH, SGOT and SGPT were not modified significantly after any drug compared to control. The results showed that two commonly used anesthetics and sedatives (ketamine and pentobarbital) have dramatic and opposite effects on extrahepatic biliary kinetics. Furthermore, ketamine, but not pentobarbital, significantly accelerates intrahepatic biliary kinetics. Finally, as expected, morphine delayed extrahepatic biliary kinetics. Thus, studies of biliary kinetics should be interpreted with caution when measurements are made after administration of anesthetic, sedative or narcotic agents.« less

  11. Telecom 2-A (TC2A)

    NASA Technical Reports Server (NTRS)

    Dulac, J.; Latour, J.

    1991-01-01

    The DSN (Deep Space Network) mission support requirements for Telecom 2-A (TC2A) are summarized. The Telecom 2-A will provide high-speed data link applications, telephone, and television service between France and overseas territories. The mission objectives are outlined and the DSN support requirements are defined through the presentation of tables and narratives describing the spacecraft flight profile; DSN support coverage; frequency assignments; support parameters for telemetry, command and support systems; and tracking support responsibility.

  12. TC-99m MIBI SPECT imaging in patients with lung carcinoma: is it a functional probe of multidrug resistance genes?

    PubMed

    Ak, Ilknur; Gülbaş, Zafer; Ocak, Suna; Kaya, Eser; Alataş, Füsun; Vardareli, Erkan; Metintaş, Muzaffer

    2007-01-01

    Multidrug-resistance (MDR) phenotype concerns altered membrane transport that results in lower cell concentrations of cytotoxic drug in many cancer types, including lung cancer, and is related to the overexpression of a variety of proteins that act as adenosine triphosphate-dependent extrusion pumps. Tc-99m Sestamibi (MIBI) is a transport substrate for P-glycoprotein (Pgp) pump. In this study, we assessed the uptake and clearance of technetium-99m-2-hexakis 2-methoxyisobutylisonitrile (Tc-99m MIBI) from the tumor and its correlation with messenger RNA (mRNA) levels of Pgp, MDR-associated protein (MRP1), and lung resistance protein (LRP) in lung carcinoma. This study was carried out on 19 patients (mean age, 60.1 +/- 2.07 years) with advanced-stage lung carcinoma. The tumor samples obtained by bronchoscopy were assessed to estimate the levels of Pgp, MRP1, and LRP expression on mRNA level by quantitative real-time reverse-transcription polymerase chain reaction. Tc-99m MIBI chest imaging was performed 15 and 180 minutes after injection of 740 MBq Tc-99m MIBI. The early (T/Be) and delayed (T/Bd) Tc-99m MIBI uptakes and washout rate (WR) of Tc-99m MIBI from the tumor were measured. No correlation was found between the T/Be Tc-99m MIBI uptake of tumors (T/Be) and the levels of Pgp mRNA, MRP1 mRNA, and LRP mRNA by reverse-transcription polymerase chain reaction. There was a correlation between the mean T/Bd Tc-99m MIBI uptake and Pgp expression of the tumors (P = 0.001, Spearman rho = - 0.702). There was a correlation between the WR of Tc-99m MIBI from the tumor and Pgp expression of the tumor (P = 0.000, Spearman rho = 0.875). Washout rate of Tc-99m MIBI was not related to the levels of MRP1 mRNA (P = 0.93, Spearman rho = 0.02) or LRP mRNA (P = 0.47, Spearman rho = 0.177). Increased WR of Tc-99m MIBI is related in Pgp over expression of the tumor. Tc-99m MIBI single photon emission computed tomography imaging may be a functional probe of overexpression of Pgp in

  13. The presence of sodium nitrate in generator eluate decreases the radiochemical purity of 99mTc-sestamibi.

    PubMed

    Métayé, Thierry; Rosenberg, Thierry; Guilhot, Joëlle; Bouin-Pineau, Marie-Hélène; Perdrisot, Rémy

    2012-09-01

    A high radiochemical purity (RCP) is recommended for radiopharmaceutical compounds used in the clinical practice of nuclear medicine. However, some preparations of (99m)Tc-sestamibi contain excess impurities (>6%). To understand the origin of these impurities, we investigated the effect of sodium nitrate on the RCP of sestamibi preparations by testing eluates from 3 commercially available (99m)Tc generators. The sestamibi kits (Stamicis) were reconstituted with (99m)Tc eluate from nitrate-containing wet-column (NCWC), nitrate-free wet-column (NFWC), and nitrate-free dry-column (NFDC) generators. Sodium nitrate was 0.05 mg/mL in eluates from the NCWC generators. The RCP was determined using aluminum oxide sheets as the stationary phase and absolute ethanol as the mobile phase. Succimer, tetrofosmin, oxidronate, exametazine, albumin nanocolloid, and soluble albumin were also tested for their RCP values with eluates from the 3 different (99m)Tc generators. The RCP assessment of (99m)Tc-sestamibi was performed on 127 Stamicis preparations. Significantly lower RCP values were found for Stamicis kits prepared with the NCWC generator than for Stamicis prepared with the NFWC (P < 0.0001) and NFDC (P < 0.0001) generators. The number of Stamicis preparations with an RCP under 94% was greater with the NCWC generator (32 of 53 kits) than with the NFDC (2 of 51 kits) or NFWC (0 of 23 kits) generator. Furthermore, the addition of a 0.05 mg/mL concentration of nitrate in NFWC generator eluates significantly decreased the RCP of the Stamicis preparation. In the absence of nitrate in (99m)Tc eluate, no difference was observed between the RCP values of Stamicis kits prepared with the NFWC and NFDC generators. The (99m)Tc impurities generated by nitrates did not modify the quality of myocardial imaging (normal heart-to-lung ratio, 2.2), probably because these impurities are not in the heart field of view. No other tested (99m)Tc-radiopharmaceutical interfered with nitrates. We

  14. 99mTc-HYNIC-TOC scintigraphy is superior to 131I-MIBG imaging in the evaluation of extraadrenal pheochromocytoma.

    PubMed

    Chen, Libo; Li, Fang; Zhuang, Hongming; Jing, Hongli; Du, Yanrong; Zeng, Zhengpei

    2009-03-01

    In this investigation, the efficacy of scintigraphy using (99m)Tc-labeled hydrazinonicotinyl-Tyr3-octreotide (HYNIC-TOC) in the evaluation of extraadrenal pheochromocytoma was assessed and compared with (131)I-labeled metaiodobenzylguanidine (MIBG) imaging. Ninety-seven patients who were suspected of having pheochromocytoma but showed no definite adrenal abnormalities on CT were evaluated by both (99m)Tc-HYNIC-TOC scintigraphy and (131)I-MIBG imaging. The results were compared with pathology findings or clinical follow-up. Of 58 patients proven to be without pheochromocytoma, (99m)Tc-HYNIC-TOC and (131)I-MIBG imaging excluded 56 and 58 patients, respectively, rendering a specificity of 96.6% for (99m)Tc-HYNIC-TOC imaging and 100% for (131)I-MIBG imaging. In the evaluation of adrenal pheochromocytoma (14 patients), the sensitivity of (99m)Tc-HYNIC-TOC scintigraphy and (131)I-MIBG imaging was 50% and 85.7%, respectively. However, in the evaluation of extraadrenal pheochromocytomas (25 patients), the sensitivity of (99m)Tc-HYNIC-TOC scintigraphy and (131)I-MIBG imaging was 96.0% and 72.0%, respectively. (99m)Tc-HYNIC-TOC scintigraphy is more sensitive than (131)I-MIBG imaging in the detection of extraadrenal pheochromocytomas.

  15. The Role of (99m)Tc-Annexin V Apoptosis Scintigraphy in Visualizing Early Stage Glucocorticoid-Induced Femoral Head Osteonecrosis in the Rabbit.

    PubMed

    Wang, Xiaolong; Liu, Yu; Wang, Xuemei; Liu, Rui; Li, Jianbo; Zhang, Guoliang; Li, Qiang; Wang, Lei; Bai, Zhigang; Zhao, Jianmin

    2016-01-01

    To validate the ability of (99m)Tc-Annexin V to visualize early stage of glucocorticoid-induced femoral head necrosis by comparing with (99m)Tc-MDP bone scanning. Femoral head necrosis was induced in adult New Zealand white rabbits by intramuscular injection of methylprednisolone. (99m)Tc-Annexin scintigraphy and (99m)Tc-MDP scans were performed before and 5, 6, and 8 weeks after methylprednisolone administration. Rabbits were sacrificed at various time points and conducted for TUNEL and H&E staining. All methylprednisolone treated animals developed femoral head necrosis; at 8 weeks postinjection, destruction of bone structure was evident in H&E staining, and apoptosis was confirmed by the TUNEL assay. This was matched by (99m)Tc-Annexin V images, which showed a significant increase in signal over baseline. Serial (99m)Tc-Annexin V scans revealed that increased (99m)Tc-Annexin V uptake could be observed in 5 weeks. In contrast, there was no effect on (99m)Tc-MDP signal until 8 weeks. The TUNEL assay revealed that bone cell apoptosis occurred at 5 weeks. (99m)Tc-Annexin V is superior to (99m)Tc-MDP for the early detection of glucocorticoid-induced femoral head necrosis in the rabbit and may be a better strategy for the early detection of glucocorticoid-induced femoral head necrosis in patients.

  16. 99mTc: Labeling Chemistry and Labeled Compounds

    NASA Astrophysics Data System (ADS)

    Alberto, R.; Abram, U.

    This chapter reviews the radiopharmaceutical chemistry of technetium related to the synthesis of perfusion agents and to the labeling of receptor-binding biomolecules. To understand the limitations of technetium chemistry imposed by future application of the complexes in nuclear medicine, an introductory section analyzes the compulsory requirements to be considered when facing the incentive of introducing a novel radiopharmaceutical into the market. Requirements from chemistry, routine application, and market are discussed. In a subsequent section, commercially available 99mTc-based radiopharmaceuticals are treated. It covers the complexes in use for imaging the most important target organs such as heart, brain, or kidney. The commercially available radiopharmaceuticals fulfill the requirements outlined earlier and are discussed with this background. In a following section, the properties and perspectives of the different generations of radiopharmaceuticals are described in a general way, covering characteristics for perfusion agents and for receptor-specific molecules. Technetium chemistry for the synthesis of perfusion agents and the different labeling approaches for target-specific biomolecules are summarized. The review comprises a general introduction to the common approaches currently in use, employing the N x S4-x , [3+1] and 2-hydrazino-nicotinicacid (HYNIC) method as well as more recent strategies such as the carbonyl and the TcN approach. Direct labeling without the need of a bifunctional chelator is briefly reviewed as well. More particularly, recent developments in the labeling of concrete targeting molecules, the second generation of radiopharmaceuticals, is then discussed and prominent examples with antibodies/peptides, neuroreceptor targeting small molecules, myocardial imaging agents, vitamins, thymidine, and complexes relevant to multidrug resistance are given. In addition, a new approach toward peptide drug development is described. The section

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

    PubMed

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

    2018-07-01

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

  18. High Tc screen-printed YBa2Cu3O(7-x) films - Effect of the substrate material

    NASA Astrophysics Data System (ADS)

    Bansal, Narottam P.; Simons, Rainee N.; Farrell, D. E.

    1988-08-01

    Thick films of YBa2Cu3O(7-x) have been deposited on highly polished alumina, magnesia spinel, nickel aluminum titanate (Ni-Al-Ti), and barium tetratitanate (Ba-Ti) substrates by the screen printing technique. Properties of the films were found to be highly sensitive to the choice of the substrate material. The film on Ba-Ti turned green after firing, due to a reaction with the substrate and were insulating. A film on Ni-Al-Ti had a Tc (onset) of about 95 K and lost 90 percent of its resistance by about 75 K. However, even at 4 K it was not fully superconducting, possibly due to a reaction between the film and the substrate and interdiffusion of the reaction products. The film on alumina had Tc (onset) of about 96 K, Tc (zero) of about 66 K, and Delta Tc of about 10 K. The best film was obtained on spinel and had Tc (onset) of about 94 K, zero resistance at 81 K, and a transition width of about 7 K.

  19. High Tc screen-printed YBa2Cu3O(7-x) films - Effect of the substrate material

    NASA Technical Reports Server (NTRS)

    Bansal, Narottam P.; Simons, Rainee N.; Farrell, D. E.

    1988-01-01

    Thick films of YBa2Cu3O(7-x) have been deposited on highly polished alumina, magnesia spinel, nickel aluminum titanate (Ni-Al-Ti), and barium tetratitanate (Ba-Ti) substrates by the screen printing technique. Properties of the films were found to be highly sensitive to the choice of the substrate material. The film on Ba-Ti turned green after firing, due to a reaction with the substrate and were insulating. A film on Ni-Al-Ti had a Tc (onset) of about 95 K and lost 90 percent of its resistance by about 75 K. However, even at 4 K it was not fully superconducting, possibly due to a reaction between the film and the substrate and interdiffusion of the reaction products. The film on alumina had Tc (onset) of about 96 K, Tc (zero) of about 66 K, and Delta Tc of about 10 K. The best film was obtained on spinel and had Tc (onset) of about 94 K, zero resistance at 81 K, and a transition width of about 7 K.

  20. Evaluation of lung epithelial permeability in the volatile substance abuse using Tc-99m DTPA aerosol scintigraphy.

    PubMed

    Cayir, Derya; Demirel, Koray; Korkmaz, Meliha; Koca, Gokhan

    2011-10-01

    Chronic inhalant use is associated with significant toxic effects, including neurological, renal, hepatic, and pulmonary damage. However, there is a paucity of reports regarding respiratory complications in inhalant abusers. The aim of this study was to evaluate pulmonary epithelial permeability in the volatile substance abuse (VSA) using Tc-99m DTPA aerosol scintigraphy. This study included 18 patients with volatile substance abuse and 18 volunteer controls. All of patients and controls were smokers. Tc-99m DTPA aerosol scintigraphy was performed in all cases. Time-activity curves from each lung were generated and clearance half-time (T(1/2)) of Tc-99m DTPA were calculated. T(1/2) of whole lung was calculated as a mean of the T(1/2) of left and right lung. The T(1/2) values of Tc-99m DTPA clearance in the substance abusers were significantly decreased as compared to the control group with respective mean values of 28.86 ± 8.44, and 62.14 ± 26.12 min (p = 0.001). It was seen Tc-99m DTPA clearance from lung was faster as the duration of substance abuse was increased. Tc-99m DTPA pulmonary clearance is markedly accelerated in the volatile substance abuse. This suggests that inhalant abuse of substance may produce abnormalities in pulmonary alveolo-capillary membrane function.

  1. Media Fill Test for validation of autologous leukocytes separation and labelling by (99m)Tc-HmPAO.

    PubMed

    Urbano, Nicoletta; Modoni, Sergio; Schillaci, Orazio

    2013-01-01

    Manufacturing of sterile products must be carried out in order to minimize risks of microbiological contamination. White blood cells (WBC) labelled with (99m)Tc-exametazime ((99m)Tc-hexamethylpropyleneamine oxime; (99m)Tc-HMPAO) are being successfully applied in the field of infection/inflammation scintigraphy for many years. In our radiopharmacy lab, separation and labelling of autologous leukocytes with (99m)Tc-HMPAO were performed in a laminar flow cabinet not classified and placed in a controlled area, whereas (99m)Tc-HMPAO radiolabelling procedure was carried out in a hot cell with manipulator gloves. This study was conducted to validate this process using a Media Fill simulation test. The study was performed using sterile Tryptic Soy Broth (TSB) in place of active product, reproducing as closely as possible the routine aseptic production process with all the critical steps, as described in the our internal standard operative procedures (SOP). The final vials containing the media of each processed step were then incubated for 14 days and examined for the evidence of microbial growth. No evidence of turbidity was observed in all the steps assayed by the Media Fill. In the separation and labelling of autologous leukocytes with (99m)Tc-HmPAO, Media-Fill test represents a reliable tool to validate the aseptic process. Copyright © 2013 Elsevier Inc. All rights reserved.

  2. Soil-to-soybean transfer of (99)Tc and its underground distribution in differently contaminated upland soils.

    PubMed

    Choi, Yong-Ho; Lim, Kwang-Muk; Jun, In; Kim, Byung-Ho; Keum, Dong-Kwon; Kim, In-Gyu

    2014-06-01

    Pot experiments were performed in a greenhouse to investigate the soil-to-soybean transfer of (99)Tc in two different upland soils labeled with (99)TcO4(-) in two contrasting ways. One was to mix the soil with a (99)TcO4(-) solution 26 d before sowing (pre-sowing deposition: PSD), and the other was to apply the solution onto the soil surface 44 d after sowing (growing-period deposition: GPD). The soil-to-plant transfer was quantified with the transfer factor (TF, ratio of the plant concentration to the average of at-planting and at-harvest soil concentrations) or the aggregated transfer factor (TFag, ratio of the plant concentration to the deposition density). For both the depositions, the transfer of (99)Tc to aerial parts decreased in the order of leaf > stem > pod > seed. TF values (dimensionless) from the PSD were 0.22 and 0.27 (no statistically significant difference) for mature dry seeds in the respective soils, whereas a 600-fold higher value occurred for dry leaves. The post-harvest concentrations of the PSD (99)Tc in the top 20 cm soils as a whole were about half the initial concentrations. Around 25% of the total applied activity remained in the GPD soils after the harvest. The post-harvest depth profiles of the GPD (99)Tc in the two soils showed similar patterns of logarithmic activity decrease with increasing soil depths. Only 1.5-4.3% of the total applied activity was removed through the harvested biomass (seeds, pods and stems), and it was estimated that a great part of the total pant uptake returned to the soil through the fallen leaves. TFag values (m(2) kg(-1)) were about 2-4 times higher for the GPD than for the PSD. This finding and generally high root uptake of Tc may indicate that the use of empirical deposition time-dependent TFag data is particularly important for predicting the plant concentrations of Tc after its growing-period deposition. Copyright © 2014 Elsevier Ltd. All rights reserved.

  3. Temperature Dependence of Quasiparticle Spectral Weight and Coherence in High Tc Superconductors

    NASA Astrophysics Data System (ADS)

    He, Yang; Zhang, Jessie; Hoffman, Jennifer; Hoffman Lab Team

    2014-03-01

    Superconductivity arises from the Cooper pairing of quasiparticles on the Fermi surface. Understanding the formation of Cooper pairs is an essential step towards unveiling the mechanism of high Tc superconductivity. We compare scanning tunneling microscope investigations of the temperature dependence of quasiparticle spectral weight and quasiparticle interference in several families of high Tc materials. We calculate the coherent spectral weight related to superconductivity, despite the coexistence of competing orders. The relation between pairing temperature and coherent spectral weight is discussed. We acknowledge support by the New York Community Trust-George Merck Fund.

  4. A novel Tc-99m and fluorescence labeled peptide as a multimodal imaging agent for targeting angiogenesis in a murine hindlimb ischemia model.

    PubMed

    Hyoun Kim, Myoung; Kim, Seul-Gi; Guhn Kim, Chang; Kim, Dae-Weung

    2017-03-01

    The serine-aspartic acid-valine (SDV) peptide binds specifically to integrin αvβ3. We developed a Tc-99m and TAMRA labeled peptide, Tc-99m SDV-ECG-K-TAMRA for multimodal imaging of angiogenesis. Tc-99m SDV-ECG-K-TAMRA was prepared in high yield (>96%) and showed low cytotoxicity. Tc-99m tetrofosmin images 1 week after operation, revealed significantly decreased perfusion of the ischemic hindlimb, and the perfusion recovered gradually for 4 weeks. In contrast, Tc-99m SDV-ECG-K-TAMRA uptake was maximal 1 week after the operation (ischemic-to-non-ischemic uptake ratio =5.03±1.01) and decreased gradually. The ischemic-to-non-ischemic ratio of Tc-99m SDV-ECG-K-TAMRA and Tc-99m tetrofosmin was strongly negatively correlated (r =-0.94). A postmortem analysis revealed increased angiogenesis markers and uptake of Tc-99m SDV-ECG-K-TAMRA by ischemic tissue. Our in vivo and in vitro studies revealed substantial uptake of Tc-99m SDV-ECG-K-TAMRA by ischemic tissue. Tc-99m SDV-ECG-K-TAMRA could be a good candidate dual-modality imaging agent to assess angiogenesis. Copyright © 2016 Elsevier Ltd. All rights reserved.

  5. Biodistribution of free and encapsulated 99mTc-fluconazole in an infection model induced by Candida albicans.

    PubMed

    de Assis, Danielle Nogueira; Araújo, Raquel Silva; Fuscaldi, Leonardo Lima; Fernandes, Simone Odília Antunes; Mosqueira, Vanessa Carla Furtado; Cardoso, Valbert Nascimento

    2018-03-01

    Candida spp is an etiologic agent of fungal infections in hospitals and resistance to treatment with antifungals has been extensively reported. Thus, it is very important to develop formulations that increase effectiveness with low toxicity. In this sense, nanocarriers have been investigated, once they modify drug biodistribution profile. Thus, this study aimed to evaluate the biodistribution of free and encapsulated 99m Tc-fluconazole into nanocapsules (NCs) in an experimental immunosuppressed murine model of Candida albicans infection. Fluconazole was radiolabeled with technetium-99 metastable ( 99m Tc) and encapsulated into conventional ( 99m Tc-Fluconazole-PLA-POLOX) and surface-modified ( 99m Tc-Fluconazole-PLA-PEG) NCs by the interfacial deposition of the preformed biodegradable polymer [poly (D,L-lactic acid) (PLA) and PLA-PEG (polyethyleneglycol)] followed by solvent evaporation. The size distribution and zeta potential of the NCs preparations were determined in a Zetasizer by photon correlation spectroscopy and laser Doppler anemometry, respectively. Free and encapsulated 99m Tc-fluconazole were administered intravenously in immunosuppressed mice bearing a local infection induced by Candida Albicans inoculation in the right thigh muscle. At pre-established time intervals, tissues and organs of interest were removed and radioactivity was measured in an automatic gamma radiation counter. The NCs diameter was between 200 and 400 nm with negative zeta potential values. Free 99m Tc-fluconazole was more rapidly eliminated by the renal system compared to the encapsulated drug in NCs, which remained longer in blood circulation. The uptake of conventional NCs by mononuclear phagocyte system organs was higher than the one demonstrated by the surface-modified NCs. Both NCs remained longer in the infectious focus when compared to free 99m Tc-fluconazole, but the results did not show a significant difference between NC formulations. These data indicate that these NCs

  6. A Thiazole Coumarin (TC) Turn-On Fluorescence Probe for AT-Base Pair Detection and Multipurpose Applications in Different Biological Systems

    NASA Astrophysics Data System (ADS)

    Narayanaswamy, Nagarjun; Kumar, Manoj; Das, Sadhan; Sharma, Rahul; Samanta, Pralok K.; Pati, Swapan K.; Dhar, Suman K.; Kundu, Tapas K.; Govindaraju, T.

    2014-09-01

    Sequence-specific recognition of DNA by small turn-on fluorescence probes is a promising tool for bioimaging, bioanalytical and biomedical applications. Here, the authors report a novel cell-permeable and red fluorescent hemicyanine-based thiazole coumarin (TC) probe for DNA recognition, nuclear staining and cell cycle analysis. TC exhibited strong fluorescence enhancement in the presence of DNA containing AT-base pairs, but did not fluoresce with GC sequences, single-stranded DNA, RNA and proteins. The fluorescence staining of HeLa S3 and HEK 293 cells by TC followed by DNase and RNase digestion studies depicted the selective staining of DNA in the nucleus over the cytoplasmic region. Fluorescence-activated cell sorting (FACS) analysis by flow cytometry demonstrated the potential application of TC in cell cycle analysis in HEK 293 cells. Metaphase chromosome and malaria parasite DNA imaging studies further confirmed the in vivo diagnostic and therapeutic applications of probe TC. Probe TC may find multiple applications in fluorescence spectroscopy, diagnostics, bioimaging and molecular and cell biology.

  7. Improvement of High-Resolution Tropical Cyclone Structure and Intensity Forecasts using COAMPS-TC

    DTIC Science & Technology

    2012-09-30

    techniques, as well as observational results from the scientific community including the recent T- PARC /TCS08 and ITOP field campaigns to build upon the...real-time COAMPS-TC forecast for the recent Hurricane Irene is shown in Figure 2. The composite National Weather Service radar reflectivity is shown in...the top panel near the time of landfall in North Carolina at 1148 UTC 27 August 2011 and the COAMPS-TC predicted radar reflectivity at 36 h valid

  8. Intravitreal injection of (99)Tc-MDP inhibits the development of laser-induced choroidal neovascularization in rhesus monkeys.

    PubMed

    Lai, Kunbei; Jin, Chenjin; Tu, Shu; Xiong, Yunfan; Huang, Rui; Ge, Jian

    2014-07-01

    The aim of this study was to investigate the safety and efficacy of intravitreal injection of (99)Tc-MDP, a decay product of (99m)Tc-MDP, on the development of laser-induced choroidal neovascularization (CNV) in rhesus monkeys. Experimental CNV was induced by argon laser with a small high-energy laser spot. Monkeys were given 50 μL of (99)Tc-MDP at a concentration of 0.005 μg/mL (n = 6) or 0.01 μg/mL (n = 6) by intravitreal injection once a week immediately after laser injury for a period of 56 days. Control animals were treated with the same volume of PBS (n = 6) in the same way. Eyes were monitored by ophthalmic examination, color fundus photography, fluorescence fundus angiography (FFA), optical coherence tomography (OCT) and histology. Incidences of grade 4 CNV lesions as well as the leakage areas of grade 4 CNVs on the late-phase of fluorescein angiograms were measured in a standardized, randomized and masked fashion fortnightly. The maximum widths and heights of grade 4 CNVs were also calculated by histology at the end of the experiment. Toxicity of (99)Tc-MDP on the retina was evaluated by electroretinogram (ERG) and histologic analysis. (99)Tc-MDP reduced the incidences of grade 4 CNVs by 33.33 % and 39.40 % in the 0.005 μg/mL and 0.01 μg/mL groups, respectively, compared with the PBS group on day 28 (P < 0.05; n = 6). The leakage areas of grade 4 CNVs were smaller in the 0.005 μg/mL (0.7136 ± 0.0283 mm(2), p <0.01; n = 6) and 0.01 μg/mL (0.4351 ± 0.0349 mm(2), p < 0.01; n = 6) groups than those in the PBS control group (0.9373 ± 0.0455 mm(2); n = 6) in a dose-dependent manner on day 28. OCT and histology also showed that the sizes of CNVs were smaller in the (99)Tc-MDP treated groups than those in the PBS group. Although intravitreal injection of (99)Tc-MDP led to mild inflammatory reaction in the anterior chamber, histology and ERG findings demonstrated that (99)Tc-MDP did not cause any change in

  9. Hydroxyapatite Based 99Mo - 99Tc and 188W - 188Re Generator Systems

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Knapp Jr, Russ F; Monroy-Guzman, F.; Badillo, V. E.

    2006-01-01

    This paper describes studies evaluating the use of hydroxyapatite as the adsorbent material for both {sup 99}Mo-{sup 99m}Tc and {sup 188}W-{sup 188}Re generator systems. Hydroxyapatite is an insoluble solid with anion exchange properties. A study of the sorption behaviour of {sup 99}Mo, {sup 99m}Tc, {sup 188}W and {sup 188}Re on hydroxyapatite in NaCl medium was evaluated by batch experiments. The results demonstrated that while {sup 99}Mo, {sup 99m}Tc and {sup 188}Re are not adsorbed by the hydroxyapatite in NaCl solutions (Kd <5), {sup 188}W is strongly adsorbed (Kd >500). On the basis of these measurements, hydroxyapatite {sup 188}W-{sup 188}Re generatormore » systems were then constructed and eluted in NaCl solutions. The hydroxyapatite based {sup 188}W-{sup 188}Re generator performances are presented.« less

  10. Tumour angiogenesis is reduced in the Tc1 mouse model of Down's syndrome.

    PubMed

    Reynolds, Louise E; Watson, Alan R; Baker, Marianne; Jones, Tania A; D'Amico, Gabriela; Robinson, Stephen D; Joffre, Carine; Garrido-Urbani, Sarah; Rodriguez-Manzaneque, Juan Carlos; Martino-Echarri, Estefanía; Aurrand-Lions, Michel; Sheer, Denise; Dagna-Bricarelli, Franca; Nizetic, Dean; McCabe, Christopher J; Turnell, Andrew S; Kermorgant, Stephanie; Imhof, Beat A; Adams, Ralf; Fisher, Elizabeth M C; Tybulewicz, Victor L J; Hart, Ian R; Hodivala-Dilke, Kairbaan M

    2010-06-10

    Down's syndrome (DS) is a genetic disorder caused by full or partial trisomy of human chromosome 21 and presents with many clinical phenotypes including a reduced incidence of solid tumours. Recent work with the Ts65Dn model of DS, which has orthologues of about 50% of the genes on chromosome 21 (Hsa21), has indicated that three copies of the ETS2 (ref. 3) or DS candidate region 1 (DSCR1) genes (a previously known suppressor of angiogenesis) is sufficient to inhibit tumour growth. Here we use the Tc1 transchromosomic mouse model of DS to dissect the contribution of extra copies of genes on Hsa21 to tumour angiogenesis. This mouse expresses roughly 81% of Hsa21 genes but not the human DSCR1 region. We transplanted B16F0 and Lewis lung carcinoma tumour cells into Tc1 mice and showed that growth of these tumours was substantially reduced compared with wild-type littermate controls. Furthermore, tumour angiogenesis was significantly repressed in Tc1 mice. In particular, in vitro and in vivo angiogenic responses to vascular endothelial growth factor (VEGF) were inhibited. Examination of the genes on the segment of Hsa21 in Tc1 mice identified putative anti-angiogenic genes (ADAMTS1and ERG) and novel endothelial cell-specific genes, never previously shown to be involved in angiogenesis (JAM-B and PTTG1IP), that, when overexpressed, are responsible for inhibiting angiogenic responses to VEGF. Three copies of these genes within the stromal compartment reduced tumour angiogenesis, explaining the reduced tumour growth in DS. Furthermore, we expect that, in addition to the candidate genes that we show to be involved in the repression of angiogenesis, the Tc1 mouse model of DS will permit the identification of other endothelium-specific anti-angiogenic targets relevant to a broad spectrum of cancer patients.

  11. Small Column Testing of Superlig 639 for Removal of 99Tc from Hanford Tank Waste Envelope C (Tank 241-AN-107)

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    DL Blanchard; DE Kurath; BM Rapko

    The current BNFL Inc. flow sheet for pretreating Hanford High-Level tank wastes includes the use of Superlig(reg.sign)639 (SL-639) in a dual column system for removing technetium-99 ({sup 99}Tc) from the aqueous fraction of the waste. This sorbent material has been developed and supplied by IBC Advanced Technologies, Inc., American Fork, UT. This report documents the results of testing the SL-639 sorbent with diluted waste [Na{sup +}] {approx} 5 M from Tank 241-AN-107 (an Envelope C waste, abbreviated AN-107) at Battelle Northwest Laboratories (BNW). The equilibrium behavior was assessed with batch contacts between the sorbent and the waste. Two AN-107 samplesmore » were used: (1) an archived sample from previous testing and (2) a more recent sample collected specifically for BNFL. A portion of the archive sample and all of the BNFL sample were treated to remove Sr-90 and transuranic elements (TRU). All samples had also been Cs decontaminated by ion exchange (IX), and were spiked with a technetium-95m ({sup 95m}Tc) pertechnetate tracer, {sup 95m}TcO{sub 4}{sup -}.The TcO{sub 4}{sup -} and total Tc K{sub d} values, assumed equal to the {sup 95m}Tc and {sup 99}Tc K{sub d}'s, respectively, are shown in Table S1. Values are averages of duplicates, which showed significant scatter. The total Tc K{sub d} for the BNFL sample is much lower than the TcO{sub 4}{sup -}, indicating that a large fraction of the {sup 99}Tc is not pertechnetate.« less

  12. Macrocyclic triamine derived glucose analogues for 99m Tc(CO)3 labeling: synthesis and biological evaluation as potential tumor-imaging agents.

    PubMed

    Liu, Teli; Gan, Qianqian; Zhang, Junbo

    2017-02-01

    [ 99m Tc(CO) 3 (H 2 O) 3 ] + has attracted great attention among 99m Tc-labeling techniques, due to its ease of preparation, readily substituted water molecules of the precursor fac-[ 99m Tc(CO) 3 (H 2 O) 3 ] + by a variety of functional groups, small size and inertness. Bifunctional chelator based on a macrocyclic polyamine framework shows easy complexation with [ 99m Tc(CO) 3 (H 2 O) 3 ] + to produce stable complex. In this study, two novel 1, 5, 9-triazacyclododecane derivatives containing a glucose group (6 and 7) were successfully synthesized by reacting different glucose-azides with alkyne-[12]aneN 3 via the so-called click chemistry and radiolabeled with [ 99m Tc(CO) 3 (H 2 O) 3 ] + to form 99m Tc(CO) 3 -6 (C-1-substituted complex) and 99m Tc(CO) 3 -7 (C-2-substituted complex) in high yields. The complexes were stable in vitro over 6 h when incubated in saline at room temperature and in mouse serum at 37 °C. The partition coefficient results showed that they were hydrophilic. The biodistribution studies in Kunming mice bearing S 180 tumor showed both complexes showed accumulation in the tumor. Between them, 99m Tc(CO) 3 -7 had the advantages of much higher tumor uptake and tumor/muscle ratio. Compared with other reported 99m Tc-radiolabeled glucose derivatives, 99m Tc(CO) 3 -7 also showed a higher tumor uptake and tumor/muscle ratio, suggesting it would be a potential candidate for further development as a tumor-imaging agent. © 2017 John Wiley & Sons A/S.

  13. A novel approach to infection imaging using a synthetic Tc-99m-labeled leukotactic peptide

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Som, P.; Oster, Z.H.; Sharma, S.

    1996-05-01

    RMT1, a synthetic peptide binding to PMN and macrophage receptors was labeled with Tc-99m and investigated as a potential imaging agent for abscess and inflammation. Experimental abscesses were induced in rabbits and dogs by turpentine and E.coli injection. After injection of Tc-99m-RMT1 two and twelve day old abscesses were visualized within 20 min. In initial studies, a dose of 30 {mu}g of peptide/3 mCi was used. This amount was subsequently reduced to 1.5 {mu}g peptide with same amount of Tc-99m yielding similar imaging results. Technetium-99m-IgG and Tc-99m-MAG-3 were used as positive and negative controls, respectively. After injection of IgG abscessesmore » were visualized but activity in blood was always higher than in abscess. When using Tc-99m RMT1 rapid abscess visualization and faster blood clearance was observed. The accumulation of RMT1 was monophasic, i.e., following the initial visualization, activity continued to build up continuously for 1{1/2} hr. Tc-99m-MAG3 accumulated initially in abscess, but activity washed out. In dogs, RMT1 blood clearance showed three components: a fast component with t{1/2}=1.9 min, 73%, intermediate t{1/2}=22 min, 24.5% and slow component, t{1/2}=115, 9.5% with 3 hours cumulative urine excretion of 40-51%. RMT1 appears to be more advantageous than currently available methods because of rapidity of imaging, simpler preparation before injection and will probably be less expensive and time consuming compared to labeled WBC. These results indicate that clinical experiments are warranted.« less

  14. Radiochemical studies of 99mTc complexes of modified cysteine ligands and bifunctional chelating agents.

    PubMed

    Pillai, M R; Kothari, K; Banerjee, S; Samuel, G; Suresh, M; Sarma, H D; Jurisson, S

    1999-07-01

    The synthesis of four novel ligands using the amino-acid cysteine and its ethyl carboxylate derivative is described. The synthetic method involves a two-step procedure, wherein the intermediate Schiff base formed by the condensation of the amino group of the cysteine substrate and salicylaldehyde is reduced to give the target ligands. The intermediates and the final products were characterized by high resolution nuclear magnetic resonance spectroscopy. Complexation studies of the ligands with 99mTc were optimized using stannous tartrate as the reducing agent under varying reaction conditions. The complexes were characterized using standard quality control techniques such as thin layer chromatography, paper electrophoresis, and paper chromatography. Lipophilicities of the complexes were estimated by solvent extraction into chloroform. Substantial changes in net charge and lipophilicity of the 99mTc complexes were observed on substituting the carboxylic acid functionality in ligands I and II with the ethyl carboxylate groups (ligands II and IV). All the ligands formed 99mTc complexes in high yield. Whereas the complexes with ligands I and II were observed to be hydrophilic in nature and not extractable into CHCl3, ligands III and IV resulted in neutral and lipophilic 99mTc complexes. The 99mTc complex with ligand II was not stable and on storage formed a hydrophilic and nonextractable species. The biodistribution of the complexes of ligands I and II showed that they cleared predominantly through the kidneys, whereas the complexes with ligands III and IV were excreted primarily through the hepatobiliary system. No significant brain uptake was observed with the 99mTc complexes with ligands III and IV despite their favorable properties of neutrality, lipophilicity, and conversion into a hydrophilic species. These ligands offer potential for use as bifunctional chelating agents.

  15. 75 FR 10244 - TC Energy Trading, LLC; Supplemental Notice That Initial Market-Based Rate Filing Includes...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-03-05

    ... DEPARTMENT OF ENERGY Federal Energy Regulatory Commission [Docket No. ER10-792-000] TC Energy Trading, LLC; Supplemental Notice That Initial Market- Based Rate Filing Includes Request for Blanket... proceeding of TC Energy Trading, LLC's application for market-based rate authority, with an accompanying rate...

  16. Multidetector computed tomography urography for diagnosing upper urinary tract urothelial tumour.

    PubMed

    Cowan, Nigel C; Turney, Ben W; Taylor, Nia J; McCarthy, Catherine L; Crew, Jeremy P

    2007-06-01

    To evaluate multidetector computed tomography urography (MDCTU) for diagnosing upper urinary tract (UUT) urothelial tumour by comparison with retrograde ureteropyelography (RUP). MDCTU and RUP were used in a selected series of adult patients presenting with haematuria. Entry criteria were based on findings on intravenous urography and were chosen to ensure a high prevalence of UUT urothelial tumour to allow a valid retrospective comparison of the diagnostic techniques. MDCTU and RUP studies were scored for the presence and absence of UUT urothelial tumour by two radiologists, retrospectively and independently, and while unaware of the demographic and clinical information. The reference standards were the histopathology and clinical follow-up. MDCTU and RUP were used in 106 patients over a 24-month period. RUP was attempted in 151 of 212 UUTs; the corresponding MDCTU for each UUT was reviewed. MDCTU was a true-positive (TP) for urothelial tumour in 31, true-negative (TN) in 111, false-positive (FP) in eight and false-negative (FN) in one UUT, giving a sensitivity of 0.97, a specificity of 0.93, a positive predictive value (PPV) of 0.79 and a negative PV (NPV) of 0.99. RUP was technically successful and diagnostic in 96% of the UUTs (143/151). For diagnosing urothelial tumour, RUP was TP in 26, TN in 112, FP in four and FN in one UUT, giving a sensitivity of 0.97, specificity of 0.93, a PPV of 0.79 and NPV of 0.99. This study validates quantitatively the use of MDCTU for diagnosing UUT urothelial tumour.

  17. Multidetector computed tomographic morphology of ovaries in cynomolgus macaques (Macaca fascicularis).

    PubMed

    Jones, Jeryl C; Appt, Susan E; Bourland, J Daniel; Hoyer, Patricia B; Clarkson, Thomas B; Kaplan, Jay R

    2007-09-01

    Macaques are important models for menopause and associated diseases in women. A sensitive, noninvasive technique for quantifying changes in ovarian morphology would facilitate longitudinal studies focused on the health-related sequelae of naturally occurring or experimentally induced alterations in ovarian structure and function. Multidetector computed tomography (MDCT) is a fast, non-invasive imaging technique that uses X-rays, multiple rows of detectors, and computers to generate detailed slice images of structures. The purpose of this study was to describe the utility of MDCT for reliably characterizing ovarian morphology in macaques. Five macaques were scanned using contrast-enhanced MDCT. The following characteristics were described: 1) appearance of ovaries and adjacent landmarks, 2) effects of varying technical protocols on ovarian image quality, 3) radiation doses delivered to the pelvic region during scanning, and 4) MDCT estimates of ovarian volume and antral follicle counts versus those measured directly in ovarian tissue. Ovaries were distinguishable in all MDCT scans and exhibited heterogeneous contrast enhancement. Antral follicles appeared as focal areas of nonenhancement. Ovarian image quality with 5 pediatric scanning protocols was sufficient for discriminating ovarian margins. Pelvic region radiation doses ranged from 0.5 to 0.7 rad. Antral follicles counted using MDCT ranged from 3 to 5 compared with 3 to 4 counted using histology. Ovarian volumes measured using MDCT ranged from 0.41 to 0.67 ml compared with 0.40 to 0.65 ml by water displacement. MDCT is a promising technique for measuring longitudinal changes in macaque ovarian morphology reliably and noninvasively.

  18. Space-time interface-tracking with topology change (ST-TC)

    NASA Astrophysics Data System (ADS)

    Takizawa, Kenji; Tezduyar, Tayfun E.; Buscher, Austin; Asada, Shohei

    2014-10-01

    To address the computational challenges associated with contact between moving interfaces, such as those in cardiovascular fluid-structure interaction (FSI), parachute FSI, and flapping-wing aerodynamics, we introduce a space-time (ST) interface-tracking method that can deal with topology change (TC). In cardiovascular FSI, our primary target is heart valves. The method is a new version of the deforming-spatial-domain/stabilized space-time (DSD/SST) method, and we call it ST-TC. It includes a master-slave system that maintains the connectivity of the "parent" mesh when there is contact between the moving interfaces. It is an efficient, practical alternative to using unstructured ST meshes, but without giving up on the accurate representation of the interface or consistent representation of the interface motion. We explain the method with conceptual examples and present 2D test computations with models representative of the classes of problems we are targeting.

  19. Tc-99m galactosyl-neoglycoalbumin: in vitro characterization of receptor-mediated binding

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Vera, D.R.; Krohn, K.A.; Stadalnik, R.C.

    1984-07-01

    Hepatic binding protein (HBP) is a membrane receptor that binds and transports plasma glycoproteins from hepatic blood to hepatocellular lysosomes. A characterization is made of the in vitro binding of Tc-99m galactosyl-neoglycoalbumin (Tc-NGA), a synthetic HBP ligand, to liver membrane. Structural modifications of NGA resulted in the alteration of the equilibrium constant, KA, and the forward-binding rate constant, kb. Binding was second-order; the relative amount of membrane-bound NGA depended on the initial concentrations of ligand and membrane. Membrane displacement studies, using carrier ligands in contrast to previously bound Tc-NGA or I-NGA, correlated with the binding characteristics of a native HBPmore » ligand, asialo-orosomucoid. Computer simulation was used to study the detectability of the changes in HBP concentration at different values of kb. The simulations indicated that radiopharmacokinetic sensitivity to alterations in (HBP) should be possible using a neoglycoalbumin preparation with a carbohydrate density within the range of 15 to 25 galactose units per albumin molecule.« less

  20. Novel Approach to Prepare {sup 99m}Tc-Based Multivalent RGD Peptides

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Shuang Liu

    2012-10-24

    This project presents a novel approach to prepare the {sup 99m}Tc-bridged multivalent RGD (arginine-glycine-aspartate) peptides. This project will focus on fundamentals of {sup 99m}Tc radiochemistry. The main objective of this project is to demonstrate the proof-of-principle for the proposed radiotracers. Once a kit formulation is developed for preparation of the {sup 99m}Tc-bridged multivalent RGD peptides, various tumor-bearing animal models will be used to evaluate their potential for SPECT (single photon-emission computed tomography) imaging of cancer. We have demonstrated that (1) multimerization of cyclic RGD peptides enhances the integrin {alpha}{sub v}{beta}{sub 3} bonding affinity and radiotracer tumor uptake; (2) addition ofmore » G{sub 3} or PEG{sub 4} linkers makes it possible for two RGD motifs in 3P-RGD{sub 2} and 3G-RGD{sub 2} to achieve simultaneous integrin {alpha}{sub v}{beta}{sub 3} binding; and (3) multimers are actually bivalent (not multivalent), the presence of extra RGD motifs can enhance the tumor retention time of the radiotracer.« less

  1. 78 FR 30269 - Foreign-Trade Zone 129-Bellingham, Washington; Authorization of Production Activity; T.C. Trading...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-05-22

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

  2. (99m)Tc-labeled gastrins of varying peptide chain length: Distinct impact of NEP/ACE-inhibition on stability and tumor uptake in mice.

    PubMed

    Kaloudi, Aikaterini; Nock, Berthold A; Lymperis, Emmanouil; Krenning, Eric P; de Jong, Marion; Maina, Theodosia

    2016-06-01

    In situ inhibition of neutral endopeptidase (NEP) has been recently shown to impressively increase the bioavailability and tumor uptake of biodegradable gastrin radioligands. Furthermore, angiotensin converting enzyme (ACE) has been previously shown to cleave gastrin analogs in vitro. In the present study, we have assessed the effects induced by single or dual NEP/ACE-inhibition on the pharmacokinetic profile of three (99m)Tc-labeled gastrins of varying peptide chain length: [(99m)Tc]SG6 ([(99m)Tc-N4-Gln(1)]gastrin(1-17)), [(99m)Tc]DG2 ([(99m)Tc-N4-Gly(4),DGlu(5)]gastrin(4-17)) and [(99m)Tc]DG4 ([(99m)Tc-N4-DGlu(10)]gastrin(10-17)). Mouse blood samples were collected 5min after injection of each of [(99m)Tc]SG6/DG2/DG4 together with: a) vehicle, b) the NEP-inhibitor phosphoramidon (PA), c) the ACE-inhibitor lisinopril (Lis), or d) PA plus Lis and were analyzed by RP-HPLC for radiometabolite detection. Biodistribution was studied in SCID mice bearing A431-CCK2R(+/-) xenografts at 4h postinjection (pi). [(99m)Tc]SG6 or [(99m)Tc]DG4 was coinjected with either vehicle or the above described NEP/ACE-inhibitor regimens; for [(99m)Tc]DG2 control and PA animal groups were only included. Treatment of mice with PA induced significant stabilization of (99m)Tc-radiotracers in peripheral blood, while treatment with Lis or Lis+PA affected the stability of des(Glu)5 [(99m)Tc]DG4 only. In line with these findings, PA coinjection led to notable amplification of tumor uptake of radiopeptides compared to controls (P<0.01). Only [(99m)Tc]DG4 profited by single Lis (2.06±0.39%ID/g vs 0.99±0.13%ID/g in controls) or combined Lis+PA coinjection (8.91±1.61%ID/g vs 4.89±1.33%ID/g in PA-group). Furthermore, kidney uptake remained favourably low and unaffected by PA and/or Lis coinjection only in the case of [(99m)Tc]DG4 (<1.9%ID/g) resulting in the most optimal tumor-to-kidney ratios. In situ NEP/ACE-inhibition diversely affected the in vivo profile of (99m)Tc-radioligands based on

  3. Phase 2 Trial of an Alpha-7 Nicotinic Receptor Agonist (TC-5619) in Negative and Cognitive Symptoms of Schizophrenia

    PubMed Central

    Walling, David; Marder, Stephen R.; Kane, John; Fleischhacker, W. Wolfgang; Keefe, Richard S. E.; Hosford, David A.; Dvergsten, Chris; Segreti, Anthony C.; Beaver, Jessica S.; Toler, Steven M.; Jett, John E.; Dunbar, Geoffrey C.

    2016-01-01

    Objectives: This trial was conducted to test the effects of an alpha7 nicotinic receptor full agonist, TC-5619, on negative and cognitive symptoms in subjects with schizophrenia. Methods: In 64 sites in the United States, Russia, Ukraine, Hungary, Romania, and Serbia, 477 outpatients (18–65 years; male 62%; 55% tobacco users) with schizophrenia, treated with a new-generation antipsychotic, were randomized to 24 weeks of placebo (n = 235), TC-5619, 5mg (n = 121), or TC-5619, 50mg (n = 121), administered orally once daily. The primary efficacy measure was the Scale for the Assessment of Negative Symptoms (SANS) composite score. Key secondary measures were the Cogstate Schizophrenia Battery (CSB) composite score and the University of California San Diego Performance-Based Skills Assessment-Brief Version (UPSA-B) total score. Secondary measures included: Positive and Negative Syndrome Scale in Schizophrenia (PANSS) total and subscale scores, SANS domain scores, CSB item scores, Clinical Global Impression-Global Improvement (CGI-I) score, CGI-Severity (CGI-S) score, and Subject Global Impression-Cognition (SGI-Cog) total score. Results: SANS score showed no statistical benefit for TC-5619 vs placebo at week 24 (5mg, 2-tailed P = .159; 50mg, P = .689). Likewise, no scores of CSB, UPSA-B, PANSS, CGI-I, CGI-S, or SGI-Cog favored TC-5619 (P > .05). Sporadic statistical benefit favoring TC-5619 in some of these outcome measures were observed in tobacco users, but these benefits did not show concordance by dose, country, gender, or other relevant measures. TC-5619 was generally well tolerated. Conclusion: These results do not support a benefit of TC-5619 for negative or cognitive symptoms in schizophrenia. PMID:26071208

  4. Permeability of ferret trachea in vitro to {sup 99m}{Tc}-DTPA and [{sup 14}C]antipyrine

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Hanafi, Z.; Webber, S.E.; Widdicombe, J.G.

    1994-09-01

    Platelet-activating factor (PAF) and vasoactive drugs were tested on permeability of ferret trachea in vitro by measuring fluxes of {sup 99m}{Tc}-diethylenetriamine pentaacetic acid ({sup 99m}{Tc}-DTPA; hydrophilic) and [{sup 14}C]antipyrine ([{sup 14}C]AP; lipophilic) across the tracheal wall. Tracheae were bathed on both sides with Krebs-Henseleit buffer, with luminal buffer containing either {sup 99m}{Tc}-DTPA or [{sup 14}C]AP. Luminal and abluminal radioactivities, potential difference, and tracheal smooth muscle tone were measured. Baseline {sup 99m}{Tc}-DTPA and [{sup 14}C]AP permeability coefficients were - 4.7 {+-} 0.6 (SE) x 10{sup {minus}7} and -2.2 {+-} 0.1 x 10{sup {minus}5} cm/s, respectively. PAF (10 {mu}M) increased permeability tomore » {sup 99m}{Tc}-DTPA to -35.3 {+-} 7.6 x 10{sup {minus}7} cm/s (P < 0.05), but permeability to [{sup 14}C]AP did not change, suggesting that paracellular but not transcellular transport was affected. Abluminal and luminal applications of methacholine (MCh, 20 {mu}M), phenylephrine (PE, 100 {mu}M), and albuterol (Alb, 100 {mu}M) caused no change in permeability to {sup 99m}{Tc}-DTPA before or after exposure to luminal PAF, but abluminal histamine (Hist, 10 {mu}M) significantly increased permeability. Abluminal Hist decreased permeability to [{sup 14}C]AP before and after exposure to PAF. MCh, PE, and Hist increased smooth muscle tone; Alb and PAF had no effect. Thus, only PAF and Hist altered permeability to {sup 99m}{Tc}-DTPA, and MCh, PE, and Hist changed smooth muscle tone. Tracheal permeability changes were greater for the hydrophilic than for the lipophilic agent. 37 refs., 11 figs., 1 tab.« less

  5. Preparation and first biological evaluation of novel Re-188/Tc-99m peptide conjugates with substance-P.

    PubMed

    Smilkov, Katarina; Janevik, Emilija; Guerrini, Remo; Pasquali, Micol; Boschi, Alessandra; Uccelli, Licia; Di Domenico, Giovanni; Duatti, Adriano

    2014-09-01

    New (188)Re and (99m)Tc peptide conjugates with substance- P (SP) were prepared and biologically evaluated. The radiopharmaceuticals have been labelled with the [M≡N](2+) (M=(99m)Tc, (188)Re) core using a combination of π-donor tridentate and π-acceptor monodentate ancillary ligands. The new radiopharmaceuticals have been prepared through a two-step reaction by simultaneous addition of the tridentate and monodentate ligands to a vial containing a preformed [M≡N](2+) core. The tridentate ligand was formed by linking two cysteine residues to the terminal arginine of the undecapeptide SP, whereas the monodentate ligand was a tertiary phosphine. The preparation of the corresponding Re-188 derivative required developing a more complex chemical procedure to obtain the [Re≡N](2+) core in satisfactory yields. Characterization of the resulting products was obtained by chromatographic methods. Biological evaluation was performed for both Tc-99m and Re-188 derivatives by in-vitro studies on isolated cells expressing NK1-receptors. In-vivo imaging in mice was carried out using a small-animal YAP(S)PET tomograph. New Tc-99m and Re-188 peptide radiopharmaceuticals with SP have been prepared in high-yield and with high-specific activity. Both Tc-99m and Re-188 peptide radioconjugates exhibit high affinity for NK1 receptors, thus giving further evidence to the empirical rule that structurally related Tc-99m and Re-188 radiopharmaceuticals exhibit identical biological properties. Copyright © 2014 Elsevier Ltd. All rights reserved.

  6. Correlation of Tc17 cells at early stages after allogeneic hematopoietic stem cell transplantation with acute graft-versus-host disease.

    PubMed

    Wang, Ling; Zhao, Peng; Song, Lingling; Yan, Fahong; Shi, Chunlei; Li, Ying; Han, Mingzhe; Lan, Ketao

    2016-12-01

    Acute graft-versus-host disease (aGVHD) is associated with an immune dysregulation usually mediated by T lymphocytes. Recently, IL-17-producing T cells including Th17 and Tc17 cells have been implicated in immune-related diseases. However, their roles in aGVHD remain uncertain. In the study, we analyzed IL-17-producing cell recovery and association with the occurrence of aGVHD. While Th17 cells steadily recovered, Tc17 cell numbers remained unaltered during the first 3months after transplantation. Occurrence of aGVHD was correlated with increased level of Tc17 cells at the second months after allo-SCT. Interestingly, Tc17 cells were negatively associated with CD4 + CD25 + FOXP3 + regulatory T (Treg) cells, which was an important prognostic predictor in patients with aGVHD. In addition, we found that Tc17 numbers increased as the increased concentrations of TGF-β and IL-6, which are known to drive Th17 polarization. These finding supported that Tc17 subset is involved in the immunopathology of aGVHD. Blocking the abnormally increased number of Tc17 may be a reasonable therapeutic strategy for aGVHD. Copyright © 2016 Elsevier B.V. All rights reserved.

  7. Histopathological Effects of the Yen-Tc Toxin Complex from Yersinia entomophaga MH96 (Enterobacteriaceae) on the Costelytra zealandica (Coleoptera: Scarabaeidae) Larval Midgut

    PubMed Central

    Hares, Michelle C.; Jones, Sandra A.; Harper, Lincoln A.; Vernon, James R.; Harland, Duane P.; Jackson, Trevor A.; Hurst, Mark R. H.

    2012-01-01

    Yersinia entomophaga MH96, which was originally isolated from the New Zealand grass grub, Costelytra zealandica, produces an orally active proteinaceous toxin complex (Yen-Tc), and this toxin is responsible for mortality in a range of insect species, mainly within the Coleoptera and Lepidoptera. The genes encoding Yen-Tc are members of the toxin complex (Tc) family, with orthologs identified in several other bacterial species. As the mechanism of Yen-Tc activity remains unknown, a histopathological examination of C. zealandica larvae was undertaken in conjunction with cultured cells to identify the effects of Yen-Tc and to distinguish the contributions that its individual subunit components make upon intoxication. A progressive series of events that led to the deterioration of the midgut epithelium was observed. Additionally, experiments using a cell culture assay system were carried out to determine the cellular effects of intoxication on cells after topical application and the transient expression of Yen-Tc and its individual components. While observations were broadly consistent with those previously reported for other Tc family members, some differences were noted. In particular, the distinct stepwise disintegration of the midgut shared features associated with both apoptosis and necrotic programmed cell death pathways. Second, we observed, for the first time, a contribution of toxicity from two chitinases associated with the Yen-Tc complex. Our findings were suggestive of the activities encoded within the subunit components of Yen-Tc targeting different sites along putative programmed cell death pathways. Given the observed broad host range for Yen-Tc, these targeted loci are likely to be widely shared among insects. PMID:22544254

  8. Reduction in clonogenic survival of sodium-iodide symporter (NIS)-positive cells following intracellular uptake of (99m)Tc versus (188)Re.

    PubMed

    Freudenberg, Robert; Wendisch, Maria; Runge, Roswitha; Wunderlich, Gerd; Kotzerke, Jörg

    2012-12-01

    Cellular radionuclide uptake increases the heterogeneity of absorbed dose to biological structures. Dose increase depends on uptake yield and emission characteristics of radioisotopes. We used an in vitro model to compare the impact of cellular uptake of (188)Re-perrhenate and (99m)Tc-pertechnetate on cellular survival. Rat thyroid PC Cl3 cells in culture were incubated with (188)Re or (99m)Tc in the presence or absence of perchlorate for 1 hour. Clonogenic cell survival was measured by colony formation. In addition, intracellular radionuclide uptake was quantified. Dose effect curves were established for (188)Re and (99m)Tc for various extra- and intracellular distributions of the radioactivity. In the presence of perchlorate, no uptake of radionuclides was detected and (188)Re reduced cell survival more efficiently than (99m)Tc. A(37), the activity that is necessary to yield 37% cell survival was 14 MBq/ml for (188)Re and 480 MBq/ml for (99m)Tc. In the absence of perchlorate, both radionuclides showed similar uptakes; however, A(37) was reduced by 30% for the beta-emitter and by 95% for (99m)Tc. The dose D(37) that yields 37% cell survival was between 2.3 and 2.8 Gy for both radionuclides. Uptake of (188)Re and (99m)Tc decreased cell survival. Intracellular (99m)Tc yielded a dose increase that was higher compared to (188)Re due to emitted Auger and internal conversion-electrons. Up to 5 Gy there was no difference in radiotoxicity of (188)Re and (99m)Tc. At doses higher than 5 Gy intracellular (99m)Tc became less radiotoxic than (188)Re, probably due to a non-uniform lognormal radionuclide uptake.

  9. Structural stability and mechanical properties of technetium mononitride (TcN)

    NASA Astrophysics Data System (ADS)

    Soni, Shubhangi; Choudhary, K. K.; Kaurav, Netram

    2018-05-01

    Among the nitrides, 3d and 4d transition metal nitrides have been investigated both experimentally and theoretically due to their predominant performances and enormous applications. In the present paper, we have attempted to predict the structural stability and mechanical properties of technetium mononitride (TcN) using an effective interionic interaction potential, which includes the long range Coulomb, van der Waals (vdW) interaction and the short-range repulsive interaction upto second-neighbor ions within the Hafemeister and Flygare approach. Our theoretical approach reveals the structural phase transition of the TcN B3 to B1 structure, wherein, the Gibbs' free energies of both the structures were minimized. The variations of elastic constants with pressure follow a systematic trend identical to that observed in other compounds of ZnS type structure family.

  10. In vivo imaging of tumour angiogenesis in mice with the alpha(v)beta (3) integrin-targeted tracer 99mTc-RAFT-RGD.

    PubMed

    Sancey, Lucie; Ardisson, Valérie; Riou, Laurent M; Ahmadi, Mitra; Marti-Batlle, Danièle; Boturyn, Didier; Dumy, Pascal; Fagret, Daniel; Ghezzi, Catherine; Vuillez, Jean-Philippe

    2007-12-01

    The molecular imaging of tumour neoangiogenesis currently represents a major field of research for the diagnostic and treatment strategy of solid tumours. Endothelial cells from tumour neovessels overexpress the alpha(v)beta(3) integrin, which selectively binds to Arg-Gly-Asp (RGD)-containing peptides. We evaluated the potential of the novel radiotracer (99m)Tc-RAFT-RGD for the non-invasive molecular imaging of alpha(v)beta(3) integrin expression in mice models of tumour development. (99m)Tc-RAFT-RGD, (99m)Tc-cRGD (specific control) and (99m)Tc-RAFT-RAD (non-specific control) were injected intravenously to mice bearing B16F0 or TS/A-pc tumours. In vivo whole-body tomographic imaging and post-mortem biodistribution studies were performed 60 min following tracer injection. Adjacent tumour slices were used to compare the localisation of neovessels from immunostaining and the pattern of (99m)Tc-RAFT-RGD uptake from autoradiographic ex vivo imaging. Biodistribution studies indicated that (99m)Tc-RAFT-RGD tumour uptake was significantly higher than that of (99m)Tc-RAFT-RAD in B16F0 (2.4+/-0.5 vs 1.0+/-0.1%ID/g, respectively) and in TS/A-pc tumours (2.7+/-0.8 vs 0.7+/-0.1%ID/g, respectively). Immunohistochemical and autoradiographic studies indicated that (99m)Tc-RAFT-RGD intratumoural uptake preferentially occurred in angiogenic areas. Tomographic imaging allowed tumour visualisation following injection of (99m)Tc-RAFT-RGD and (99m)Tc-cRGD with similar tumour-to-contralateral muscle (T/CM) ratios in B16F0 and in TS/A-pc tumours whereas (99m)Tc-RAFT-RAD T/CM ratios did not allow tumour imaging. In accordance with the higher level of alpha(v)beta(3) integrin expression on TS/A-pc tumours than on B16F0 tumours as determined from western blot and immunoprecipitation analyses, the (99m)Tc-RAFT-RGD T/CM ratio was significantly higher in TS/A-pc than in B16F0 tumours. (99m)Tc-RAFT-RGD allowed the in vivo imaging of alpha(v)beta(3) integrin tumour expression.

  11. Physiological expression of pancreatic somatostatin receptors in 99mTc-HYNIC-TOC scintigraphy.

    PubMed

    de la Cueva, L; Lloro, P; Sangrós, M J; López Vélez, L; Navarro, P; Sarria, L; Álvarez, S; Abós, D

    2017-07-01

    To describe the frequency of head and/or pancreas uncinate process uptake of 99mTc-HYNIC-TOC, to study its nature, and analyze its diagnostic value. Retrospective evaluation of 47 consecutive 99mTc-HYNIC-TOC examinations was conducted. Head and/or pancreas uncinate process uptake was considered to be physiological in patients with normal CT at the same episode and in follow-up. It was analyzed if age or diabetes mellitus was justifying the existence or not of uptake. 32.5% patients showed uptake; 73% of them were mild. 84.6% patients with uptake have no pathology and 4% had neuroendocrine pancreatic disease at CT. Neither the age nor the diabetes mellitus established differences in patients without lesion. Near one-third of patients show physiological uptake by head and/or pancreas uncinate process at 99mTc-HYNIC-TOC scintigraphy. It seems that neither the diabetes nor the ages are factors that determine this physiological uptake.

  12. Blockade of IL-23 ameliorates allergic lung inflammation via decreasing the infiltration of Tc17 cells.

    PubMed

    Cheng, Sheng; Chen, Huilong; Wang, Aili; Bunjhoo, Hansvin; Cao, Yong; Xie, Jungang; Xu, Yongjian; Xiong, Weining

    2016-12-01

    Tc17 cells are interleukin (IL)-17-producing CD8 + T cells and have been found to participate in the development of allergic asthma. Interleukin-23 is a cytokine that may be involved in modulating the IL-17 response via Th17 cells. This study aimed to investigate whether IL-23 also has immunomodulatory effects on Tc17 cells. An allergic asthmatic mouse model was induced by sensitizing and challenging with ovalbumin (OVA). Anti-IL-23 antibody was administered intratracheally before challenge to the OVA-induced asthmatic mouse model. Airway hyperresponsiveness, lung inflammation, Tc17 cell percentages and IL-17 level in the lung tissue homogenate were measured. Anti-IL-23 treatment reduced airway hyperresponsiveness (Rn 2.471 ±0.5077 vs. 4.051 ±0.2334, p < 0.05), inflammatory cell infiltration in bronchoalveolar lavage fluid (eosinophils 140.0 ±9.869 vs. 222.4 ±31.55, p < 0.05, neutrophils 75.93 ±6.745 vs. 127.4 ±19.73, p < 0.05), airway inflammation and mucus secretion. Treatment with anti-IL-23 antibody also markedly reduced IL-17 level (398.1 ±28.74 vs. 590.6 ±36.13, p < 0.01) and percentage of Th17 and Tc17 cells in lung tissue homogenate (4.200 ±0.1581 vs. 9.314 ±1.027, p < 0.01 and 2.852 ±0.2566 vs. 5.588 ±0.3631, p < 0.01, Th17 and Tc17 cells respectively). Our data suggest that the IL-23/Tc17 cell axis may be involved in the pathogenesis of asthma as the complement of IL-23/Th17 cells.

  13. Bone scintigraphy of the aged patient. 1. /sup 99m/Tc-polyphosphate bone scintigraphy (in Japanese)

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Yamamoto, M.; Chiba, K.; Tanno, M.

    Application and evaluation of a new bone-seeking radiopharmaceuticai, / sup 99m/Tc-polyphosphate are reported. Analysis of the image by digital color display data analyzer (Phosdac) was performed. The subjects of the study were cases at Tokyo Metropolitan Geriatric Hospital ranging from 63 to 85 years old with several kinds of bone diseases. Polyphosphate kits (Diagnostic Isotopes, Inc.) were used to prepare /sup 99m/Tc, and a Rho/gamma HP gamma-camera was used for scintigraphy. The images obtained were analyzed by Phosdac to obtain clear image of the bone system. In the final preparation, presence of approximately 30% of free /sup 99m/Tc was noticedmore » by paper chromatography. /sup 99m/Tc- polyphosphate was cleared from the blood with a half time of about 60 min. Urinary excretion proved to be 40 to 60% within 24 hrs. The bone system was visualized rather clearly with high accumulation of the label in the diseased region in spite of the fact that geriatric cases had marked general osteoporotic tendencies. In some cases, ribs were clearly visualized, and different information from that of x-ray was obtained by scanning images. Data processing by Phosdac increased diagnostic accuracy by enhancing the difference of the density of the image as well as eliminating the background caused by free /sup 99m/TcO/sub 4/. In conclusion, /sup 99m/Tc-polyphosphate was proved to be useful for bone scanning in geriatric cases. A digital color display data analyzer was successfully applied for the processing of the original data. (auth)« less

  14. Dependence of the quasiparticle recombination rate on the superconducting gap and TC

    NASA Astrophysics Data System (ADS)

    Carr, G. L.; Xi, Xiaoxiang; Hwang, J.; Tashiro, H.; Reitze, D. H.; Tanner, D. B.

    2010-03-01

    The relaxation of excess quasiparticles in a BCS superconductor is known to depend on quantities such as the quasiparticle & phonon density of states, and their coupling (Kaplan et al, Phys. Rev. B 14 4854, 1976). Disorder or an applied field can disrupt superconductivity, as evidenced by a reduced TC. We consider some simple modifications to the quasiparticle density of states consistent with a suppressed energy gap and TC, leading to changes in the intrinsic and effective (measured) rates for excess quasiparticles to recombine into pairs. We review some results for disordered MoGe and discuss the magnetic-field dependence of the recombination process.

  15. Small GTPase Tc10 and its homologue RhoT induce N-WASP-mediated long process formation and neurite outgrowth.

    PubMed

    Abe, Tomoyuki; Kato, Masayoshi; Miki, Hiroaki; Takenawa, Tadaomi; Endo, Takeshi

    2003-01-01

    Rho family small GTPases regulate multiple cellular functions through reorganization of the actin cytoskeleton. Among them, Cdc42 and Tc10 induce filopodia or peripheral processes in cultured cells. We have identified a member of the family, designated as RhoT, which is closely related to Tc10. Tc10 was highly expressed in muscular tissues and brain and remarkably induced during differentiation of C2 skeletal muscle cells and neuronal differentiation of PC12 and N1E-115 cells. On the other hand, RhoT was predominantly expressed in heart and uterus and induced during neuronal differentiation of N1E-115 cells. Tc10 exogenously expressed in fibroblasts generated actin-filament-containing peripheral processes longer than the Cdc42-formed filopodia, whereas RhoT produced much longer and thicker processes containing actin filaments. Furthermore, both Tc10 and RhoT induced neurite outgrowth in PC12 and N1E-115 cells, but Cdc42 did not do this by itself. Tc10 and RhoT as well as Cdc42 bound to the N-terminal CRIB-motif-containing portion of N-WASP and activated N-WASP to induce Arp2/3-complex-mediated actin polymerization. The formation of peripheral processes and neurites by Tc10 and RhoT was prevented by the coexpression of dominant-negative mutants of N-WASP. Thus, N-WASP is essential for the process formation and neurite outgrowth induced by Tc10 and RhoT. Neuronal differentiation of PC12 and N1E-115 cells induced by dibutyryl cyclic AMP and by serum starvation, respectively, was prevented by dominant-negative Cdc42, Tc10 and RhoT. Taken together, all these Rho family proteins are required for neuronal differentiation, but they exert their functions differentially in process formation and neurite extension. Consequently, N-WASP activated by these small GTPases mediates neuronal differentiation in addition to its recently identified role in glucose uptake.

  16. Assessment of functional liver reserve: old and new in 99mTc-sulfur colloid scintigraphy.

    PubMed

    Matesan, Manuela M; Bowen, Stephen R; Chapman, Tobias R; Miyaoka, Robert S; Velez, James W; Wanner, Michele F; Nyflot, Matthew J; Apisarnthanarax, Smith; Vesselle, Hubert J

    2017-07-01

    A semiquantitative assessment of hepatic reticuloendothelial system function using colloidal particles scintigraphy has been proposed previously as a surrogate for liver function evaluation. In this article, we present an updated method for the overall assessment of technetium-99m (Tc)-sulfur colloid (SC) biodistribution that combines information from planar and attenuation-corrected Tc-SC single-photon emission computed tomography (SPECT) images. The imaging protocol described here was developed as an easy-to-implement method to assess overall and regional liver function changes associated with chronic liver disease. Thirty patients with chronic liver disease and primary liver cancers underwent Tc-SC whole-body planar imaging and upper-abdomen SPECT/computed tomography (CT) imaging before external beam radiation therapy. Liver plus spleen and bone marrow counts as a fraction of whole-body total counts were calculated from SC planar imaging. Attenuation correction Tc-SC images were rigidly coregistered with treatment planning CT images that contained liver and spleen regions-of-interest. Ratios of total liver counts to total spleen counts were obtained from the aligned Tc-SC SPECT and CT images, and were subsequently used to separate liver plus spleen counts obtained on the planar images. This hybrid SPECT/CT and planar scintigraphy approach yielded an updated estimation of whole-body SC distribution. These biodistribution estimates were compared with historical data for reference. Statistical associations of Tc-SC biodistribution to liver function parameters and liver disease scoring systems (Child-Pugh) were evaluated by Spearman rank correlation. Percentages of Tc-SC uptake ranged from 19.3 to 77.3% for the liver; 3.4 to 40.7% for the spleen; and 19.0 to 56.7% for the bone marrow. Spearman's correlation coefficient showed a significant statistical association between Child-Pugh score and bone marrow uptake at 0.55 (P≤0.05), liver uptake at 0.71 (P≤0

  17. The lymphoscintigraphic manifestation of (99m)Tc-dextran lymphatic imaging in primary intestinal lymphangiectasia.

    PubMed

    Wen, Zhe; Tong, Guansheng; Liu, Yong; Meeks, Jacqui K; Ma, Daqing; Yang, Jigang

    2014-05-01

    The aim of this study was to analyze the imaging characteristics of (99m)Tc-dextran ((99m)Tc-DX) lymphatic imaging in the diagnosis of primary intestinal lymphangiectasia (PIL). Forty-one PIL patients were diagnosed as having PIL with the diagnosis being subsequently confirmed by laparotomy, endoscopy, biopsy, or capsule colonoscopy. Nineteen patients were male and 22 were female. A whole-body (99m)Tc-DX scan was performed at 10 min, 1 h, 3 h, and 6 h intervals after injection. The 10 min and 1 h postinjection intervals were considered the early phase, the 3 h postinjection interval was considered the middle phase, and the 6 h postinjection interval was considered the delayed phase. The imaging characteristics of (99m)Tc-DX lymphatic imaging in PIL were of five different types: (i) presence of dynamic radioactivity in the intestine, associated with radioactivity moving from the small intestine to the ascending and transverse colon; (ii) presence of delayed dynamic radioactivity in the intestine, no radioactivity or little radioactivity distributing in the intestine in the early phase, or significant radioactivity distributing in the intestine in the delayed phase; (iii) radioactivity distributing in the intestine and abdominal cavity; (iv) radioactivity distributing only in the abdominal cavity with no radioactivity in the intestines; and (v) no radioactivity distributing in the intestine and abdominal activity. (99m)Tc-DX lymphatic imaging in PIL showed different imaging characteristics. Caution should be exercised in the diagnosis of PIL using lymphoscintigraphy. Lymphoscintigraphy is a safe and accurate examination method and is a significant diagnostic tool in the diagnosis of PIL.

  18. Evaluation of ⁹⁹(m)Tc-labeled antibiotics for infection detection.

    PubMed

    Lambrecht, Fatma Yurt

    2011-01-01

    One of the fields of research in nuclear medicine is the development of new radiopharmaceuticals for imaging infection and inflammation in humans. For this development, several antimicrobial peptides, antibiotics, antibiotic peptide and chemotactic peptides, etc., have been radiolabeled with different radionuclides (⁶⁷Ga, ⁹⁹(m)Tc, ¹¹¹In, ¹⁸F, ¹³¹I, etc.) and their imaging potentials studied. Actually, it is very important to distinguish between infection and inflammation. In this respect, radiolabeled antibiotics have advantages because many of the properties of the ideal infection-specific agent through antibiotics localizes in infection site. In this review, only ⁹⁹(m)Tc-labeled antibiotics are evaluated and discussed.

  19. A Thiazole Coumarin (TC) Turn-On Fluorescence Probe for AT-Base Pair Detection and Multipurpose Applications in Different Biological Systems

    PubMed Central

    Narayanaswamy, Nagarjun; Kumar, Manoj; Das, Sadhan; Sharma, Rahul; Samanta, Pralok K.; Pati, Swapan K.; Dhar, Suman K.; Kundu, Tapas K.; Govindaraju, T.

    2014-01-01

    Sequence-specific recognition of DNA by small turn-on fluorescence probes is a promising tool for bioimaging, bioanalytical and biomedical applications. Here, the authors report a novel cell-permeable and red fluorescent hemicyanine-based thiazole coumarin (TC) probe for DNA recognition, nuclear staining and cell cycle analysis. TC exhibited strong fluorescence enhancement in the presence of DNA containing AT-base pairs, but did not fluoresce with GC sequences, single-stranded DNA, RNA and proteins. The fluorescence staining of HeLa S3 and HEK 293 cells by TC followed by DNase and RNase digestion studies depicted the selective staining of DNA in the nucleus over the cytoplasmic region. Fluorescence-activated cell sorting (FACS) analysis by flow cytometry demonstrated the potential application of TC in cell cycle analysis in HEK 293 cells. Metaphase chromosome and malaria parasite DNA imaging studies further confirmed the in vivo diagnostic and therapeutic applications of probe TC. Probe TC may find multiple applications in fluorescence spectroscopy, diagnostics, bioimaging and molecular and cell biology. PMID:25252596

  20. Real-time new satellite product demonstration from microwave sensors and GOES-16 at NRL TC web

    NASA Astrophysics Data System (ADS)

    Cossuth, J.; Richardson, K.; Surratt, M. L.; Bankert, R.

    2017-12-01

    The Naval Research Laboratory (NRL) Tropical Cyclone (TC) satellite webpage (https://www.nrlmry.navy.mil/TC.html) provides demonstration analyses of storm imagery to benefit operational TC forecast centers around the world. With the availability of new spectral information provided by GOES-16 satellite data and recent research into improved visualization methods of microwave data, experimental imagery was operationally tested to visualize the structural changes of TCs during the 2017 hurricane season. This presentation provides an introduction into these innovative satellite analysis methods, NRL's next generation satellite analysis system (the Geolocated Information Processing System, GeoIPSTM), and demonstration the added value of additional spectral frequencies when monitoring storms in near-realtime.

  1. OAT3-mediated extrusion of the 99mTc-ECD metabolite in the mouse brain

    PubMed Central

    Kikuchi, Tatsuya; Okamura, Toshimitsu; Wakizaka, Hidekatsu; Okada, Maki; Odaka, Kenichi; Yui, Joji; Tsuji, Atsushi B; Fukumura, Toshimitsu; Zhang, Ming-Rong

    2014-01-01

    After administration of the 99mTc complex with N,N'-1,2-ethylenediylbis-L-cysteine diethyl ester (99mTc-ECD), a brain perfusion imaging agent, the radioactive metabolite is trapped in primate brain, but not in mouse and rat. Here, we investigate the involvement of metabolite extrusion by organic anion transporter 3 (OAT3), which is highly expressed at the blood–brain barrier in mice, in this species difference. The efflux rate of radioactivity in the cerebrum of Oat3−/− mice at later phase was 20% of that of control mice. Thus, organic anion transporters in mouse brain would be involved in the low brain retention of radioactivity after 99mTc-ECD administration. PMID:24496177

  2. Pulmonary involvement in rheumatoid arthritis: multidetector computed tomography findings.

    PubMed

    Yuksekkaya, Ruken; Celikyay, Fatih; Yilmaz, Ayse; Arslan, Sule; Inanir, Ahmet; Inonu, Handan; Deniz, Caglar

    2013-12-01

    Pulmonary involvement in rheumatoid arthritis (RA) is common and encompasses a large spectrum of disease with different treatment options and prognoses. Therefore, assessment of these patients with multidetector computed tomography (MDCT) is vital. To evaluate the MDCT pulmonary findings of patients with RA and to compare these findings with the clinical status. Chest MDCT scans of 85 patients with RA between 2006-2012 were assessed. One patient with a pulmonary infection was excluded from the study. MDCT findings and distribution of the CT findings were examined, and patients were classified according to the predominant CT pattern. The pulmonary function test (PFT) results and categories, demographic characteristics, and clinical status of some of the patients for whom the results were obtained were evaluated, and the CT findings, PFT results, demographic characteristics, and clinical status were compared. The study group consisted of 20 men (mean age, 58.1 years ± 13.1; range, 15-77 years) and 64 women (mean age, 55.3 years ± 11.5; range, 30-84 years). The most frequent findings were nodules (78.6%) and pleural thickening (48.8%). The most common CT patterns were follicular bronchiolitis (FB) in 28 (33.3%) patients and nodular disease (ND) in 12 (14.3%) others. There was no statistically significant difference between the CT findings and PFT results, and no statistically significant difference was noted in the CT findings between symptomatic and asymptomatic patients. In addition, there were some patients who exhibited no symptoms and/or had abnormal PFT results but had abnormal CT findings. Rheumatoid arthritis is associated with a high frequency of CT findings and CT patterns, with nodules and pleural thickening being the most common CT findings and FB and ND being the most common CT patterns. MDCT identification of patients with RA may be helpful in the evaluation of pulmonary disease, even in patients without symptoms and PFT abnormalities.

  3. 99mTc-EDDA/HYNIC-TOC: a new 99mTc-labelled radiopharmaceutical for imaging somatostatin receptor-positive tumours; first clinical results and intra-patient comparison with 111In-labelled octreotide derivatives.

    PubMed

    Decristoforo, C; Mather, S J; Cholewinski, W; Donnemiller, E; Riccabona, G; Moncayo, R

    2000-09-01

    [111In-diethylene triamine penta-acetic acid-D-Phe1]-octreotide (DTPA-octreotide) scintigraphy has gained widespread acceptance as a diagnostic clinical procedure in oncology for imaging somatostatin receptor-positive tumours. However, indium-111 as a radiolabel has several drawbacks, including limited availability, suboptimal gamma energy and high radiation burden to the patient. We have recently reported on the preclinical development of 99mTc-EDDA/HYNIC-TOC, a new octreotide derivative which showed promising results both in vitro and in vivo. We now report our initial clinical experiences with this new radiopharmaceutical in ten oncological patients. The clinical diagnoses were: carcinoid syndrome (n=5), thyroid cancer (n=3), pancreatic cancer (n=1) and pituitary tumour (n=1). The biodistribution and kinetics of 99mTc-EDDA/HYNIC-TOC were compared with those of 111In-DTPA-octreotide in six cases, and with those of 111In-DOTA-TOC in five cases. With the new tracer tumours were imaged within 15 min after injection and showed the highest target/non-target ratios 4 h after injection. Tumour uptake persisted up to 20 h p.i. The rate of blood clearance was similar to that of 111In-DTPA-octreotide but faster than that of 111In-DOTA-TOC, while urinary excretion was lower compared with the 111In derivatives. Semi-quantitative region of interest analysis showed that 99mTc-EDDA/HYNIC-TOC produced higher tumour/organ (target/non-target) ratios than the 111In derivatives, especially in relation to heart and muscle. Significantly more lesions could be detected in 99mTc images. We conclude that 99mTcEDDA/HYNIC-TOC shows better imaging properties for the identification of somatostatin receptor-positive tumour sites than currently available 111In-labelled octreotide derivatives.

  4. Morphometric analysis of sex differences in contemporary Japanese pelves using multidetector computed tomography.

    PubMed

    Torimitsu, Suguru; Makino, Yohsuke; Saitoh, Hisako; Sakuma, Ayaka; Ishii, Namiko; Yajima, Daisuke; Inokuchi, Go; Motomura, Ayumi; Chiba, Fumiko; Yamaguchi, Rutsuko; Hashimoto, Mari; Hoshioka, Yumi; Iwase, Hirotaro

    2015-12-01

    Sex estimation of decomposed or skeletal remains is clearly important in forensic contexts. Recently, contemporary population-specific data has been obtained using multidetector computed tomography (MDCT) scanning. The main purpose of this study was to investigate skeletal pelvic dimorphism in a contemporary Japanese forensic sample and to quantify the accuracy of sex estimation using various pelvic measurements obtained from three-dimensional (3D) CT images. This study used a total of 208 cadavers (104 males, 104 females) of which postmortem CT scanning and subsequent forensic autopsy were conducted between December 2011 and August 2014. Eleven measurements of each pelvis were obtained from 3D CT reconstructed images that extracted only bone data. The measurements were analyzed using descriptive statistics and discriminant function analyses. All except one measurement were dimorphic in terms of sex differences. Univariate discriminant function analyses using these measurements provided sex classification accuracy rates of 62.0-98.1%. The subpubic angle was found to contribute most significantly to accurate sex estimation. Multivariate discriminant functions yielded sex prediction accuracy rates of 63.9-98.1%. In conclusion, the pelvic measurements obtained from 3D CT images of a contemporary Japanese population successfully demonstrated sexual dimorphism and may be useful for the estimation of skeletal sex in the field of forensic anthropology. Copyright © 2015 Elsevier Ireland Ltd. All rights reserved.

  5. Radiation dose of digital tomosynthesis for sinonasal examination: comparison with multi-detector CT.

    PubMed

    Machida, Haruhiko; Yuhara, Toshiyuki; Tamura, Mieko; Numano, Tomokazu; Abe, Shinji; Sabol, John M; Suzuki, Shigeru; Ueno, Eiko

    2012-06-01

    Using an anthropomorphic phantom, we have investigated the feasibility of digital tomosynthesis (DT) of flat-panel detector (FPD) radiography to reduce radiation dose for sinonasal examination compared to multi-detector computed tomography (MDCT). A female Rando phantom was scanned covering frontal to maxillary sinus using the clinically routine protocol by both 64-detector CT (120 kV, 200 mAs, and 1.375-pitch) and DT radiography (80 kV, 1.0 mAs per projection, 60 projections, 40° sweep, and posterior-anterior projections). Glass dosimeters were used to measure the radiation dose to internal organs including the thyroid gland, brain, submandibular gland, and the surface dose at various sites including the eyes during those scans. We compared the radiation dose to those anatomies between both modalities. In DT radiography, the doses of the thyroid gland, brain, submandibular gland, skin, and eyes were 230 ± 90 μGy, 1770 ± 560 μGy, 1400 ± 80 μGy, 1160 ± 2100 μGy, and 112 ± 6 μGy, respectively. These doses were reduced to approximately 1/5, 1/8, 1/12, 1/17, and 1/290 of the respective MDCT dose. For sinonasal examinations, DT radiography enables dramatic reduction in radiation exposure and dose to the head and neck region, particularly to the lens of the eye. Copyright © 2011 Elsevier Ireland Ltd. All rights reserved.

  6. Technical issues of a high-Tc superconducting bulk magnet

    NASA Astrophysics Data System (ADS)

    Fujimoto, Hiroyuki

    2000-06-01

    Superconducting magnets made of high-Tc superconductors are promising for industrial applications. It is well known that REBa2Cu3O7-x superconductors prepared by melt processes have a high critical current density, Jc, at 77 K and high magnetic fields. The materials are very promising for high magnetic field applications as a superconducting permanent/bulk magnet with liquid-nitrogen refrigeration. Light rare-earth (LRE) BaCuO bulks, compared with REBaCuO bulks, exhibit a larger Jc in high magnetic fields and a much improved irreversibility field, Hirr, at 77 K. In this study, we discuss technical issues of a high-Tc superconducting bulk magnet, namely the aspects of the melt processing for bulk superconductors, their characteristic superconducting properties and mechanical properties, and trapped field properties of a superconducting bulk magnet. One of the possible applications is a superconducting bulk magnet for the magnetically levitated (Maglev) train in the future.

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

    PubMed

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

    2016-10-01

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

  8. [Contamination levels to room air arising from the use of 99mTc-gas and prevention from the contamination].

    PubMed

    Komatani, A; Akutsu, T; Yamaguchi, K; Onodera, Y; Manaka, Y; Takahashi, K

    1996-04-01

    99mTc-gas (TECHNEGAS) is a 99mTc-labeled micro-aerosol which is considered to have different behavior from 133Xe or 81mKr gas. In order to estimate contamination levels to room air arising from the use of 99mTc-gas, filtered expired air during administration and 1, 2, 3, 5, 10 min after the administration were collected in each polyethylene bag. Radioactivities of the polyethylene bags, used filter and the lung were measured with 3-head scintillation camera. The activity of the expired air diminished within 6-10 min and about 5% of whole discharged 99mTc-gas was released to room air. The activity of the used filter was two times of the lung. According to these results, it is recommended that the 99mTc-gas may be administrated in a exclusive room. The administrated patient and used filter must be remain in the exclusive room.

  9. The protein family TcTASV-C is a novel Trypanosoma cruzi virulence factor secreted in extracellular vesicles by trypomastigotes and highly expressed in bloodstream forms.

    PubMed

    Caeiro, Lucas D; Alba-Soto, Catalina D; Rizzi, Mariana; Solana, María Elisa; Rodriguez, Giselle; Chidichimo, Agustina M; Rodriguez, Matías E; Sánchez, Daniel O; Levy, Gabriela V; Tekiel, Valeria

    2018-05-01

    TcTASV-C is a protein family of about 15 members that is expressed only in the trypomastigote stage of Trypanosoma cruzi. We have previously shown that TcTASV-C is located at the parasite surface and secreted to the medium. Here we report that the expression of different TcTASV-C genes occurs simultaneously at the trypomastigote stage and while some secreted and parasite-associated products are found in both fractions, others are different. Secreted TcTASV-C are mainly shedded through trypomastigote extracellular vesicles, of which they are an abundant constituent, despite its scarce expression on culture-derived trypomastigotes. In contrast, TcTASV-C is highly expressed in bloodstream trypomastigotes; its upregulation in bloodstream parasites was observed in different T. cruzi strains and was specific for TcTASV-C, suggesting that some host-molecules trigger TcTASV-C expression. TcTASV-C is also strongly secreted by bloodstream parasites. A DNA prime-protein boost immunization scheme with TcTASV-C was only partially effective to control the infection in mice challenged with a highly virulent T. cruzi strain. Vaccination triggered a strong humoral response that delayed the appearance of bloodstream trypomastigotes at the early phase of the infection. Linear epitopes recognized by vaccinated mice were mapped within the TcTASV-C family motif, suggesting that blockade of secreted TcTASV-C impacts on the settlement of infection. Furthermore, although experimental and naturally T. cruzi-infected hosts did not react with antigens from extracellular vesicles, vaccinated and challenged mice recognized not only TcTASV-C but also other vesicle-antigens. We hypothesize that TcTASV-C is involved in the establishment of the initial T. cruzi infection in the mammalian host. Altogether, these results point towards TcTASV-C as a novel secreted virulence factor of T. cruzi trypomastigotes.

  10. Insights into the failure of the potential, neutral myocardial imaging agent TcN-NOET: physicochemical identification of by-products and degradation species.

    PubMed

    Tisato, Francesco; Bolzati, Cristina; Refosco, Fiorenzo; Porchia, Marina; Seraglia, Roberta; Carta, Davide; Pasqualini, Roberto

    2012-04-01

    The neutral complex [(99m)Tc(N)(NOEt)(2)], often referred to as TcN-NOET [NOEt=N-ethoxy,N-ethyldithiocarbamate(1-)], was proposed several years ago as a myocardial imaging agent. Despite some favorable clinical properties evidenced during phase I and phase II studies, the overall results of the European and American phase III clinical studies have been judged insufficient for a successful approval process by the regulatory agencies. Non-carrier-added and carrier-added experiments using short-lived (99m)Tc and long-lived (99g)Tc have been utilized to prepare a series of bis-substituted [Tc(N)(DTC)(2)] complexes [DTC=dithiocarbamate(1-)]. They have been purified by means of chromatographic techniques (high-performance liquid chromatography and thin-layer chromatography) and identified via double detection (UV-vis and radiometry) by comparison with authenticated samples of (99g)Tc compounds prepared by conventional coordination chemistry procedures. The molecular structure of the lipophilic, neutral complex cis-[Tc(N)(NOEt)(2)] has been assigned by comparison with similar nitrido-Tc(V) complexes already reported in the literature. Novel bis-substituted nitrido-Tc complexes containing hydrolyzed portions of coordinated NOEt, namely, N-ethyldithiocarbamate [NHEt(1-)] and N-hydroxy, N-ethyldithiocarbamate [NOHEt(1-)], have been prepared and characterized by means of multinuclear nuclear magnetic resonance spectroscopy and mass spectrometry. Despite the identification of these "hydrolyzed" species, it is still unclear whether the failure to reach the clinical goal of the perfusion tracer [(99m)Tc(N)(NOEt)(2)] is related to the degradation processes evidenced in this study or is the result of the mediocre imaging properties of the tracer. Copyright © 2012 Elsevier Inc. All rights reserved.

  11. Synthesis and evaluation of Tc-99m and fluorescence-labeled elastin-derived peptide, VAPG for multimodal tumor imaging in murine tumor model.

    PubMed

    Kim, Myoung Hyoun; Kim, Chang Guhn; Kim, Seul-Gi; Kim, Dae-Weung

    2017-12-01

    We developed a Tc-99m and fluorescence-labeled peptide, Tc-99m TAMRA-GHEG-ECG-VAPG to target tumor cells and evaluated the diagnostic performance as a dual-modality imaging agent for tumor in a murine model. TAMRA-GHEG-ECG-VAPG was synthesized by using Fmoc solid-phase peptide synthesis. Radiolabeling of TAMRA-GHEG-ECG-VAPG with Tc-99m was done by using ligand exchange via tartrate. Binding affinity and in vitro cellular uptake studies were performed. Gamma camera imaging, biodistribution, and ex vivo imaging studies were performed in murine models with SW620 tumors. Tumor tissue slides were prepared and analyzed with immunohistochemistry by using confocal microscopy. After radiolabeling procedures with Tc-99m, Tc-99m TAMRA-GHEG-ECG-VAPG complexes were prepared in high yield (>96%). The K d of Tc-99m TAMRA-GHEG-ECG-VAPG determined by saturation binding was 16.8 ± 3.6 nM. Confocal microscopy images of SW620 cells incubated with TAMRA-GHEG-ECG-VAPG showed strong fluorescence in the cytoplasm. Gamma camera imaging revealed substantial uptake of Tc-99m TAMRA-GHEG-ECG-VAPG in tumors. Tumor uptake was effectively blocked by the coinjection of an excess concentration of VAPG. Specific uptake of Tc-99m TAMRA-GHEG-ECG-VAPG was confirmed by biodistribution, ex vivo imaging, and immunohistochemistry stain studies. In vivo and in vitro studies revealed substantial uptake of Tc-99m TAMRA-GHEG-ECG-VAPG in tumor cells. Tc-99m TAMRA-GHEG-ECG-VAPG has potential as a dual-modality tumor imaging agent. Copyright © 2017 John Wiley & Sons, Ltd.

  12. Advances of multidetector computed tomography in the characterization and staging of renal cell carcinoma

    PubMed Central

    Tsili, Athina C; Argyropoulou, Maria I

    2015-01-01

    Renal cell carcinoma (RCC) accounts for approximately 90%-95% of kidney tumors. With the widespread use of cross-sectional imaging modalities, more than half of RCCs are detected incidentally, often diagnosed at an early stage. This may allow the planning of more conservative treatment strategies. Computed tomography (CT) is considered the examination of choice for the detection and staging of RCC. Multidetector CT (MDCT) with the improvement of spatial resolution and the ability to obtain multiphase imaging, multiplanar and three-dimensional reconstructions in any desired plane brought about further improvement in the evaluation of RCC. Differentiation of RCC from benign renal tumors based on MDCT features is improved. Tumor enhancement characteristics on MDCT have been found closely to correlate with the histologic subtype of RCC, the nuclear grade and the cytogenetic characteristics of clear cell RCC. Important information, including tumor size, localization, and organ involvement, presence and extent of venous thrombus, possible invasion of adjacent organs or lymph nodes, and presence of distant metastases are provided by MDCT examination. The preoperative evaluation of patients with RCC was improved by depicting the presence or absence of renal pseudocapsule and by assessing the possible neoplastic infiltration of the perirenal fat tissue and/or renal sinus fat compartment. PMID:26120380

  13. Multidetector row computed tomography evaluation of the micropig kidney as a potential renal donor.

    PubMed

    Yoon, Woong; Lee, Min Young; Ryu, Jung Min; Moon, Yong Ju; Lee, Sang Hun; Park, Jae Hong; Yun, Seung Pil; Jang, Min Woo; Park, Sung Su; Han, Ho Jae

    2010-03-01

    Multidetector row computed tomography (MDCT) provides anatomical information about the kidney and other internal organs. Presently, the suitability of 64-channel MDCT to assess the kidney of healthy micropigs was evaluated. Morphological evaluations of the kidney and the major renal vessels of six healthy micropigs were carried out using MDCT, recording kidney volume and the diameter and length of renal arteries and veins. The mean diameters and lengths of the renal artery were 0.44 +/- 0.05 and 4.51 +/- 0.55 cm on the right side and 0.46 +/- 0.06 and 3.36 +/- 0.27 cm on the left side, respectively. The mean diameters and lengths of the renal vein were 1.44 +/- 0.52 and 4.22 +/- 1.29 cm on the right side and 1.38 +/- 0.17 and 5.15 +/- 0.87 cm on the left side, respectively. The mean volume of the right kidney was 79.3 +/- 14.5 mL and of the left kidney was 78.0 +/- 13.9 mL. The data presented in this study suggest that the MDCT offers a noninvasive, rapid, and accurate method for the evaluation of the renal anatomy in living kidney donors. It also provides sufficient information about extra-renal anatomy important for donor surgery and determination of organ suitability.

  14. Phase 2 Trial of an Alpha-7 Nicotinic Receptor Agonist (TC-5619) in Negative and Cognitive Symptoms of Schizophrenia.

    PubMed

    Walling, David; Marder, Stephen R; Kane, John; Fleischhacker, W Wolfgang; Keefe, Richard S E; Hosford, David A; Dvergsten, Chris; Segreti, Anthony C; Beaver, Jessica S; Toler, Steven M; Jett, John E; Dunbar, Geoffrey C

    2016-03-01

    This trial was conducted to test the effects of an alpha7 nicotinic receptor full agonist, TC-5619, on negative and cognitive symptoms in subjects with schizophrenia. In 64 sites in the United States, Russia, Ukraine, Hungary, Romania, and Serbia, 477 outpatients (18-65 years; male 62%; 55% tobacco users) with schizophrenia, treated with a new-generation antipsychotic, were randomized to 24 weeks of placebo (n = 235), TC-5619, 5mg (n = 121), or TC-5619, 50 mg (n = 121), administered orally once daily. The primary efficacy measure was the Scale for the Assessment of Negative Symptoms (SANS) composite score. Key secondary measures were the Cogstate Schizophrenia Battery (CSB) composite score and the University of California San Diego Performance-Based Skills Assessment-Brief Version (UPSA-B) total score. Secondary measures included: Positive and Negative Syndrome Scale in Schizophrenia (PANSS) total and subscale scores, SANS domain scores, CSB item scores, Clinical Global Impression-Global Improvement (CGI-I) score, CGI-Severity (CGI-S) score, and Subject Global Impression-Cognition (SGI-Cog) total score. SANS score showed no statistical benefit for TC-5619 vs placebo at week 24 (5 mg, 2-tailed P = .159; 50 mg, P = .689). Likewise, no scores of CSB, UPSA-B, PANSS, CGI-I, CGI-S, or SGI-Cog favored TC-5619 (P > .05). Sporadic statistical benefit favoring TC-5619 in some of these outcome measures were observed in tobacco users, but these benefits did not show concordance by dose, country, gender, or other relevant measures. TC-5619 was generally well tolerated. These results do not support a benefit of TC-5619 for negative or cognitive symptoms in schizophrenia. © The Author 2015. Published by Oxford University Press on behalf of the Maryland Psychiatric Research Center. All rights reserved. For permissions, please email: journals.permissions@oup.com.

  15. Effectiveness of TC-325 (Hemospray) for treatment of diffuse or refractory upper gastrointestinal bleeding - a single center experience.

    PubMed

    Cahyadi, Oscar; Bauder, Markus; Meier, Benjamin; Caca, Karel; Schmidt, Arthur

    2017-11-01

    TC-325 (Hemospray, Cook Medical) is a powder agent for endoscopic hemostasis in patients with upper gastrointestinal bleeding (UGIB). Although most publications are based on case-reports and retrospective studies, data on efficacy are promising. Here we report our experience with TC-325 for diffuse or refractory UGIB.  Data on patients receiving TC-325 for endoscopic hemostasis from November 2013 to February 2017 at our center were analyzed retrospectively. Primary endpoints were technical success (successful immediate hemostasis) and clinical success (effective hemostasis and no recurrent bleeding). Secondary endpoints were recurrent bleeding within 3 and 7 days, hospital mortality and TC-325 associated complications. TC-325 was used for bleeding not amenable to standard endoscopic treatment (e. g. diffuse bleeding) or as salvage therapy after failure of conventional methods.  Fifty-two patients received TC-325 treatment. Most of the patients were treated for peptic ulcer bleeding (18/52 patients, 34.6 %) and post-interventional bleeding (13/52 patients, 25 %). Hemospray was used in 23/52 (44.2 %) patients as monotherapy and in 29/52 (55.8 %) patients as a salvage therapy. Application of the powder on the bleeding source was successful in all patients with no therapy-related adverse events (AEs). Immediate hemostasis was achieved in 51/52 (98.1 %) patients. Recurrent bleeding within 3 and 7 days was observed in 22/51 and 25/51 patients respectively (43.1 % and 49 %). The overall clinical success was 56.9 % on day 3 and 51 % on day 7. Total mortality was 15.4 % (8 patients), bleeding associated mortality was 3.8 % (2 patients). There were no therapy-related AEs.  TC-325 showed a high technical success rate as monotherapy for bleeding sources not amenable to standard methods or as an "add-on" therapy after unsuccessful hemostasis. However, rebleeding was frequent in this cohort and further studies are warranted to exactly define a

  16. First principles study of structural stability, electronic structure and mechanical properties of ReN and TcN

    NASA Astrophysics Data System (ADS)

    Rajeswarapalanichamy, R.; Kavitha, M.; Sudha Priyanga, G.; Iyakutti, K.

    2015-03-01

    The crystal structure, structural stability, electronic and mechanical properties of ReN and TcN are investigated using first principles calculations. We have considered five different crystal structures: NaCl, zinc blende (ZB), NiAs, tungsten carbide (WC) and wurtzite (WZ). Among these ZB phase is found to be the lowest energy phase for ReN and TcN at normal pressure. Pressure induced structural phase transitions from ZB to WZ phase at 214 GPa in ReN and ZB to NiAs phase at 171 GPa in TcN are predicted. The electronic structure reveals that both ReN and TcN are metallic in nature. The computed elastic constants indicate that both the nitrides are mechanically stable. As ReN in NiAs phase has high bulk and shear moduli and low Poisson's ratio, it is found to be a potential ultra incompressible super hard material.

  17. The TcI and TcII Trypanosoma cruzi experimental infections induce distinct immune responses and cardiac fibrosis in dogs

    PubMed Central

    Duz, Ana Luiza Cassin; Vieira, Paula Melo de Abreu; Roatt, Bruno Mendes; Aguiar-Soares, Rodrigo Dian Oliveira; Cardoso, Jamille Mirelle de Oliveira; de Oliveira, Flávia Carvalho Bitencourt; Reis, Levi Eduardo Soares; Tafuri, Washington Luiz; Veloso, Vanja Maria; Reis, Alexandre Barbosa; Carneiro, Cláudia Martins

    2014-01-01

    Trypanosoma cruzi infection may be caused by different strains with distinct discrete typing units (DTUs) that can result in variable clinical forms of chronic Chagas disease. The present study evaluates the immune response and cardiac lesions in dogs experimentally infected with different T. cruzi strains with distinct DTUs, namely, the Colombian (Col) and Y strains of TcI and TcII DTU, respectively. During infection with the Col strain, increased levels of alanine aminotransferase, erythrocytes, haematocrit and haemoglobin were observed. In addition, CD8+ T-lymphocytes isolated from the peripheral blood produced higher levels of interleukin (IL)-4. The latter suggests that during the acute phase, infection with the Col strain may remain unnoticed by circulating mononuclear cells. In the chronic phase, a significant increase in the number of inflammatory cells was detected in the right atrium. Conversely, infection with the Y strain led to leucopoenia, thrombopoenia, inversion of the ratio of CD4+/CD8+ T-lymphocytes and alterations in monocyte number. The Y strain stimulated the production of interferon-γ by CD4+ and CD8+ T-lymphocytes and IL-4 by CD8+ T-cells. In the chronic phase, significant heart inflammation and fibrosis were observed, demonstrating that strains of different DTUs interact differently with the host. PMID:25591108

  18. TC-PTP directly interacts with connexin43 to regulate gap junction intercellular communication

    PubMed Central

    Li, Hanjun; Spagnol, Gaelle; Naslavsky, Naava; Caplan, Steve; Sorgen, Paul L.

    2014-01-01

    ABSTRACT Protein kinases have long been reported to regulate connexins; however, little is known about the involvement of phosphatases in the modulation of intercellular communication through gap junctions and the subsequent downstream effects on cellular processes. Here, we identify an interaction between the T-cell protein tyrosine phosphatase (TC-PTP, officially known as PTPN2) and the carboxyl terminus of connexin43 (Cx43, officially known as GJA1). Two cell lines, normal rat kidney (NRK) cells endogenously expressing Cx43 and an NRK-derived cell line expressing v-Src with temperature-sensitive activity, were used to demonstrate that EGF and v-Src stimulation, respectively, induced TC-PTP to colocalize with Cx43 at the plasma membrane. Cell biology experiments using phospho-specific antibodies and biophysical assays demonstrated that the interaction is direct and that TC-PTP dephosphorylates Cx43 residues Y247 and Y265, but does not affect v-Src. Transfection of TC-PTP also indirectly led to the dephosphorylation of Cx43 S368, by inactivating PKCα and PKCδ, with no effect on the phosphorylation of S279 and S282 (MAPK-dependent phosphorylation sites). Dephosphorylation maintained Cx43 gap junctions at the plaque and partially reversed the channel closure caused by v-Src-mediated phosphorylation of Cx43. Understanding dephosphorylation, along with the well-documented roles of Cx43 phosphorylation, might eventually lead to methods to modulate the regulation of gap junction channels, with potential benefits for human health. PMID:24849651

  19. [(99m)Tc(CO)(3)]-radiolabeled bevacizumab: in vitro and in vivo evaluation in a melanoma model.

    PubMed

    Camacho, Ximena; García, María Fernanda; Calzada, Victoria; Fernández, Marcelo; Chabalgoity, Jose A; Moreno, Maria; Barbosa de Aguiar, Rodrigo; Alonso, Omar; Gambini, Juan Pablo; Chammas, Roger; Cabral, Pablo

    2013-01-01

    Vascular endothelial growth factor (VEGF) is one of the classic factors to tumor-induced angiogenesis in several tumor types, including melanoma. Bevacizumab, a monoclonal antibody against VEGF, could be used as an imaging tool in preclinical studies. To radiolabel bevacizumab with [(99m)Tc(CO)3(OH2)3](+) and evaluate it in vivo and in vitro for melanoma imaging properties. Bevacizumab was radiolabeled with [(99m)Tc(CO)3(OH2)3](+) ion in saline. The radiochemical stability of the labeled antibody was assessed. The biodistribution and scintigraphy imaging of the radiolabeled antibody were evaluated in normal C57BL/6J mice and in C57BL/6J mice bearing murine B16F1 melanoma tumors. Immunoreactivity of bevacizumab to murine tumors was determined from direct immunofluorescence and immunoblotting assays. We demonstrate that (99m)Tc(CO)3-bevacizumab was stable. In vivo biodistribution studies revealed that tumor uptake of (99m)Tc(CO)3-bevacizumab was 2.64 and 2.51 %ID/g at 4 and 24 h postinjection. Scintigraphy image studies showed tumor selective uptake of (99m)Tc(CO)3-bevacizumab in the tumor-bearing mice. This affinity was confirmed by immunoassays performed on B16F10 tumor samples. (99m)Tc(CO)3-bevacizumab could be used as an approach for tumor nuclear imaging in preclinical studies. This should be useful to provide insights into the angiogenic stimulus before and after chemotherapy, which might help improve current antitumor therapy. Copyright © 2013 S. Karger AG, Basel.

  20. TcPho91 is a contractile vacuole phosphate sodium symporter that regulates phosphate and polyphosphate metabolism in Trypanosoma cruzi

    PubMed Central

    Jimenez, Veronica; Docampo, Roberto

    2015-01-01

    Summary We have identified a phosphate transporter (TcPho91) localized to the bladder of the contractile vacuole complex (CVC) of Trypanosoma cruzi, the etiologic agent of Chagas disease. TcPho91 has 12 transmembrane domains, an N-terminal regulatory SPX domain and an anion permease domain. Functional expression in Xenopus laevis oocytes followed by two-electrode voltage clamp showed that TcPho91 is a low affinity transporter with a Km for Pi in the millimolar range, and sodium-dependency. Epimastigotes overexpressing TcPho91-GFP have significantly higher levels of pyrophosphate (PPi) and short chain polyphosphate (polyP), suggesting accumulation of Pi in these cells. Moreover, when overexpressing parasites were maintained in a medium with low Pi, they grew at higher rates than control parasites. Only one allele of TcPho91 in the CL strain encodes for the complete open reading frame, while the other one is truncated encoding for only the N-terminal domain. Taking advantage of this characteristic, knockdown experiments were performed resulting in cells with reduced growth rate as well as a reduction in PPi and short-chain polyP levels. Our results indicate that TcPho91 is a phosphate sodium symporter involved in Pi homeostasis in T. cruzi. PMID:26031800