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Sample records for bone seeking radiotracer

  1. Intestinal uptake of bone seeking radiotracer: possible mechanisms and review of the literature

    Energy Technology Data Exchange (ETDEWEB)

    Kim, D. W.; Kim, C. G.; Park, S. A.; Chang, J. A. [WonKwang University Hospital, Iksan (Korea, Republic of)

    2007-07-01

    This study was undertaken to investigate the frequency of intestinal accumulation of Tc-99m 3, 3-diphosphono-1, 2-propanedicarboxylic acid (DPD) on bone scans, describe the patterns of intestinal Tc-99m DPD uptake and discuss the possible mechanisms of this unusual finding. Three thousand, one hundred and ninety-four consecutive patients have been evaluated for intestinal Tc-99m DPD uptake on bone scans. A whole-body bone scan and various spot views were obtained to evaluate the location and intensity of intestinal uptake. Delayed scan and SPECT study were performed to define characteristics of intestinal uptake in some of patients. Available reports of co-relative radiologic imaging, endoscopic studies and laboratory tests were also reviewed to explain the intestinal uptake. Eighteen (9 female, 9 male) patients out of 3194 with a mean age of 57 years showed intestinal Tc-99m DPD uptake. The locations of intestinal uptake were well dispersed throughout the abdomen. The majority of the cases showed lower intensity than iliac spine (12/18, 67%). Eight patients didn't show significant change of uptake characteristics on the delayed images, while intestinal uptake traveled distally in nine patients. Two cases were revealed uptake of peritoneal carcinomatosis with small amount ascites and three cases were revealed tumoral uptake of intestine. Four patients with gastritis showed similar characteristic of intestinal uptake. Six cases of distally traveled intestinal uptake suggested intraluminal Tc-99m DPD activity such as gastrointestinal bleeding. However, stool occult blood tests were negative in three patients, and there is no clinical evidence of gastrointestinal bleeding in other three patients. Intestinal Tc-99m DPD uptake can be observed in 0.5% of bone scans. The mechanism of intestinal uptake is still unclear in some of the patients. Delayed imaging additional spot views and SPECT studies help in the differentiation of this finding from possible

  2. Evaluation of bone-seeking novel radiotracer {sup 68}Ga-NO2AP-Bisphosphonate for the detection of skeletal metastases in carcinoma breast

    Energy Technology Data Exchange (ETDEWEB)

    Passah, Averilicia; Tripathi, Madhavi; Ballal, Sanjana; Yadav, Madhav Prasad; Kumar, Rajeev; Chakraborty, Partha Sarathi; Bal, Chandrasekhar [All India Institute of Medical Sciences, Department of Nuclear Medicine, Ansari Nagar, New Delhi (India); Roesch, Frank; Meckel, Marian [Johannes-Gutenberg-University, Nuclear Chemistry, Mainz (Germany)

    2017-01-15

    The successful labelling of bisphosphonates (BP) with {sup 68}Ga using macrocyclic chelators such as the based triazacyclononane (NO2AP) is a step forward in the in-house availability of a novel bone-seeking PET radiopharmaceutical with dual advantage of PET/CT imaging and generator production. In this study, we compared the novel generator-based skeletal radiotracer {sup 68}Ga-1,4,7-triazacyclonone-1,4-diacetic acid ({sup 68}Ga-NO2AP-BP) with sodium fluoride ({sup 18}F-NaF) for the detection of skeletal metastases in breast cancer patients. In addition, dosimetric analysis of {sup 68}Ga-NO2AP-BP was performed in a subset of patients. This was a prospective study of histopathologically proven cases of breast cancer patients who were referred for bone scintigraphy and underwent positron emission tomography/computed tomography (PET/CT) with {sup 18}F-NaF and {sup 68}Ga-NO2AP-BP within a week in random order. The scans of each patient were compared both qualitatively for image quality and quantitatively for number of lesions and SUVmax of lesions. Dosimetric analysis was performed in five patients. Their PET/CT scans were acquired at multiple time points and urine and blood samples were collected. Dosimetric calculations were performed using OLINDA/EXM 1.1 software. Statistical analysis was done using Stata 13 (StataCorp) software package. An agreement analysis regarding number of lesions detected with the two skeletal radiotracers was carried out. The image quality of {sup 68}Ga-NO2AP-BP PET/CT scans were comparable to that of {sup 18}F-NaF. There was no statistically significant difference in the SUVmax of lesions, normal bone and lesion to background ratio between the two skeletal radiotracers. There was good agreement in the number of lesions detected by both skeletal radiotracers. The mean whole body effective dose for {sup 68}Ga-NO2AP-BP was 0.00583 mSv/MBq and the effective dose equivalent was 0.0086 mSv/MBq. The excellent lesion detection agreement between

  3. Evaluation of bone-seeking novel radiotracer (68)Ga-NO2AP-Bisphosphonate for the detection of skeletal metastases in carcinoma breast.

    Science.gov (United States)

    Passah, Averilicia; Tripathi, Madhavi; Ballal, Sanjana; Yadav, Madhav Prasad; Kumar, Rajeev; Roesch, Frank; Meckel, Marian; Sarathi Chakraborty, Partha; Bal, Chandrasekhar

    2017-01-01

    The successful labelling of bisphosphonates (BP) with (68)Ga using macrocyclic chelators such as the based triazacyclononane (NO2AP) is a step forward in the in-house availability of a novel bone-seeking PET radiopharmaceutical with dual advantage of PET/CT imaging and generator production. In this study, we compared the novel generator-based skeletal radiotracer (68)Ga-1,4,7-triazacyclonone-1,4-diacetic acid ((68)Ga-NO2AP-BP) with sodium fluoride ((18)F-NaF) for the detection of skeletal metastases in breast cancer patients. In addition, dosimetric analysis of (68)Ga-NO2AP-BP was performed in a subset of patients. This was a prospective study of histopathologically proven cases of breast cancer patients who were referred for bone scintigraphy and underwent positron emission tomography/computed tomography (PET/CT) with (18)F-NaF and (68)Ga-NO2AP-BP within a week in random order. The scans of each patient were compared both qualitatively for image quality and quantitatively for number of lesions and SUVmax of lesions. Dosimetric analysis was performed in five patients. Their PET/CT scans were acquired at multiple time points and urine and blood samples were collected. Dosimetric calculations were performed using OLINDA/EXM 1.1 software. Statistical analysis was done using Stata 13 (StataCorp) software package. An agreement analysis regarding number of lesions detected with the two skeletal radiotracers was carried out. The image quality of (68)Ga-NO2AP-BP PET/CT scans were comparable to that of (18)F-NaF. There was no statistically significant difference in the SUVmax of lesions, normal bone and lesion to background ratio between the two skeletal radiotracers. There was good agreement in the number of lesions detected by both skeletal radiotracers. The mean whole body effective dose for (68)Ga-NO2AP-BP was 0.00583 mSv/MBq and the effective dose equivalent was 0.0086 mSv/MBq. The excellent lesion detection agreement between (68)Ga-NO2AP-BP and (18)F-NaF favours the

  4. Bone-seeking therapeutic radiopharmaceuticals

    Directory of Open Access Journals (Sweden)

    Srivastava Suresh C.

    2002-01-01

    Full Text Available Bone-seeking therapeutic radiopharmaceuticals are utilized on the basis of the radionuclide?s particulate emissions (primarily low to intermediate beta emission. The requirements therefore are different from those of bone imaging agents that consist mainly of short-lived single photon emitters. Lately, the therapeutic bone seeking radiopharmaceuticals have attained increasing importance due to their potential role in alleviating pain from osseous metastases in cancer patients, for the treatment of joint pain resulting from inflamed synovium (radiosynoviorthesis, or radiosynovectomy, or from various other forms of arthritic disease. There is, however, a paucity of published data on the bio-pharmacokinetics of these agents when used following intravenous administration for bone pain palliation. This paper will briefly review and summarize the presently available chemical and biopharmacokinetic information on the various clinically approved as well as experimental bone-localizing therapeutic radiopharmaceuticals, and make projections on their clinical application for the treatment of primary/metastatic cancer in bone.

  5. Functional investigation of bone implant viability using radiotracers in a new model of osteonecrosis

    OpenAIRE

    Luis Schiper; Bluma Linkowski Faintuch; Roberto José da Silva Badaró; Erica Aparecida de Oliveira; Arana Chavez, Victor E.; Elisangela Chinen; Joel Faintuch

    2016-01-01

    OBJECTIVES: Conventional imaging methods are excellent for the morphological characterization of the consequences of osteonecrosis; however, only specialized techniques have been considered useful for obtaining functional information. To explore the affinity of radiotracers for severely devascularized bone, a new mouse model of isolated femur implanted in a subcutaneous abdominal pocket was devised. To maintain animal mobility and longevity, the femur was harvested from syngeneic donors. Two ...

  6. Functional investigation of bone implant viability using radiotracers in a new model of osteonecrosis

    Directory of Open Access Journals (Sweden)

    Luis Schiper

    Full Text Available OBJECTIVES: Conventional imaging methods are excellent for the morphological characterization of the consequences of osteonecrosis; however, only specialized techniques have been considered useful for obtaining functional information. To explore the affinity of radiotracers for severely devascularized bone, a new mouse model of isolated femur implanted in a subcutaneous abdominal pocket was devised. To maintain animal mobility and longevity, the femur was harvested from syngeneic donors. Two technetium-99m-labeled tracers targeting angiogenesis and bone matrix were selected. METHODS: Medronic acid and a homodimer peptide conjugated with RGDfK were radiolabeled with technetium-99m, and biodistribution was evaluated in Swiss mice. The grafted and control femurs were evaluated after 15, 30 and 60 days, including computed tomography (CT and histological analysis. RESULTS: Radiolabeling achieved high (>95% radiochemical purity. The biodistribution confirmed good blood clearance 1 hour after administration. For 99mTc-hydrazinonicotinic acid (HYNIC-E-[c(RGDfK2, remarkable renal excretion was observed compared to 99mTc-methylene diphosphonate (MDP, but the latter, as expected, revealed higher bone uptake. The results obtained in the control femur were equal at all time points. In the implanted femur, 99mTc-HYNIC-E-[c(RGDfK2 uptake was highest after 15 days, consistent with early angiogenesis. Regarding 99mTc-MDP in the implant, similar uptake was documented at all time points, consistent with sustained bone viability; however, the uptake was lower than that detected in the control femur, as confirmed by histology. CONCLUSIONS: 1 Graft viability was successfully diagnosed using radiotracers in severely ischemic bone at all time points. 2 Analogously, indirect information about angiogenesis could be gathered using 999mTc-HYNIC-E-[c(RGDfK2. 3 These techniques appear promising and warrant further studies to determine their potential clinical applications.

  7. Functional investigation of bone implant viability using radiotracers in a new model of osteonecrosis

    Science.gov (United States)

    Schiper, Luis; Faintuch, Bluma Linkowski; da Silva Badaró, Roberto José; de Oliveira, Erica Aparecida; Chavez, Victor E. Arana; Chinen, Elisangela; Faintuch, Joel

    2016-01-01

    OBJECTIVES: Conventional imaging methods are excellent for the morphological characterization of the consequences of osteonecrosis; however, only specialized techniques have been considered useful for obtaining functional information. To explore the affinity of radiotracers for severely devascularized bone, a new mouse model of isolated femur implanted in a subcutaneous abdominal pocket was devised. To maintain animal mobility and longevity, the femur was harvested from syngeneic donors. Two technetium-99m-labeled tracers targeting angiogenesis and bone matrix were selected. METHODS: Medronic acid and a homodimer peptide conjugated with RGDfK were radiolabeled with technetium-99m, and biodistribution was evaluated in Swiss mice. The grafted and control femurs were evaluated after 15, 30 and 60 days, including computed tomography (CT) and histological analysis. RESULTS: Radiolabeling achieved high (>95%) radiochemical purity. The biodistribution confirmed good blood clearance 1 hour after administration. For 99mTc-hydrazinonicotinic acid (HYNIC)-E-[c(RGDfK)2, remarkable renal excretion was observed compared to 99mTc-methylene diphosphonate (MDP), but the latter, as expected, revealed higher bone uptake. The results obtained in the control femur were equal at all time points. In the implanted femur, 99mTc-HYNIC-E-[c(RGDfK)2 uptake was highest after 15 days, consistent with early angiogenesis. Regarding 99mTc-MDP in the implant, similar uptake was documented at all time points, consistent with sustained bone viability; however, the uptake was lower than that detected in the control femur, as confirmed by histology. CONCLUSIONS: 1) Graft viability was successfully diagnosed using radiotracers in severely ischemic bone at all time points. 2) Analogously, indirect information about angiogenesis could be gathered using 999mTc-HYNIC-E-[c(RGDfK)2. 3) These techniques appear promising and warrant further studies to determine their potential clinical applications.

  8. Treatment with bone-seeking radionuclides for painful bone metastases in patients with lung cancer

    DEFF Research Database (Denmark)

    Zacho, Helle D; Karthigaseu, Nita Nishanthiny; Fuglsang, Randi

    2017-01-01

    Treatment with bone-seeking radionuclides may provide palliation from pain originating from bone metastases. However, most studies have been conducted in patients with prostate cancer and patients with breast cancer. We aimed to perform a systematic review of the use of radionuclide treatment...

  9. Abnormal gastrointestinal accumulation of radiotracer by gastric bleeding during {sup 99m}Tc-MDP bone scintigraphy

    Energy Technology Data Exchange (ETDEWEB)

    Chun, Kyung A.; Lee, Sang Woo; Lee, Jae Tae; Lee, Kyu Bo [College of Medicine, Kyungpook National Univ., Taegu (Korea, Republic of)

    1998-06-01

    We present a case in which a patient with acute hemorrhagic gastritis demonstrated abnormal gastrointestinal accumulation of radiotracer during {sup 99m}Tc-methylene diphosphonate (MDP) skeletal scintigraphy. A hemorrhagic gastritis was subsequently demonstrated by endoscopy. The mechanism for the intestinal localization of {sup 99m}Tc-MDP in this patients is not clear, but we guess that the extravasated blood containing the radiopharmaceutical cannot recirculate and stays at the bleeding site, so we can see the intestinal activity.

  10. Radiotracers for medical applications

    Energy Technology Data Exchange (ETDEWEB)

    Rayudu, G.A.S.

    1983-01-01

    This book discusses the medical applications of radiotracers. Diagnostic uses and pharmacokinetics of isotopes and radiopharmaceuticals is emphasized. The volume one covers the following topics: Radiohalogenated compounds, including radioiodine; Tc-labeled compounds; and in-house prepared radiopharmaceuticals. The charge particle range vs. energy in every element is tabulated for protons for cyclotrons users. Discussions are also provided on nonimaging radiotracer methods; /sup 11/C, /sup 13/N, /sup 15/O, /sup 67/Ga. /sup 111/In, /sup 75/Se, /sup 123m/Te compounds; radioactive noble gases; and miscellaneous radiotracers for imaging. Vol. II: Pertinent nuclear science data such as radiation dosimetry, radionuclide production modes, radionuclides for therapy, human experimentation regulations and consent forms, and radiotracer laboratory designs are presented. 272 pp., 7 x 10, 1983, ISBN-0-8493-6016-1.

  11. Principles of radiotracer methodology

    Energy Technology Data Exchange (ETDEWEB)

    Kisieleski, W.E.

    1975-06-01

    Information is presented on the properties of radioisotopes and radiations, methods and equipment for radiation detection, safety in handling radioactive materials, the biological effects of radiation, and the design of radiotracer studies. (LCL)

  12. New bone-seeking agent. Animal study of Tc-99m-incadronate

    Energy Technology Data Exchange (ETDEWEB)

    Shigematsu, Makoto; Shiomi, Susumu; Iwao, Hiroshi; Ochi, Hironobu [Osaka City Univ. (Japan). Graduate School of Medicine

    2002-02-01

    Disodium cycloheptylaminomethylenediphosphonate monohydrate (incadronate disodium) is a third-generation bisphosphonate compound which potently inhibits bone resorption, and a highly effective drug in the treatment of metastatic bone disease. We first labeled incadronate disodium with {sup 99m}Tc, and examined its biodistribution and bone uptake after intravenous injection in rats to assess its potential for clinical use as a bone-seeking agent for judgment of the therapeutic effect of incadronate on bone metastases. Bone scan with {sup 99m}Tc-labeled incadronate ({sup 99m}Tc-incadronate) may yield important information prior to the use of incadronate for treatment of bone metastases. Synthesis of {sup 99m}Tc-incadronate was carried out by reduction of {sup 99m}Tc-pertechnetate in the presence of SnCl{sub 2} and N{sub 2} gas. Normal rats were injected with 18.5 MBq (0.5 mCi) {sup 99m}Tc-incadronate in a volume of 0.1 ml intravenously and then sacrificed at 15 min, 30 min, 1 h or 2 h (six rats at each time point) after injection. Samples of muscle, stomach, small intestine, kidney, liver and bone (femur) were taken and weighed. In addition, a 1-ml sample of blood was drawn from the heart, and urine was taken from the urinary bladder immediately after sacrifice. Samples were measured for radioactivity and expressed as percent uptake of injected dose per gram or per milliliter (% ID/g or ml). Bone-to-blood and bone-to-muscle uptake ratios were determined from the % ID/g or ml values for these organs. The greatest accumulation of {sup 99m}Tc-incadronate was found in bone. Radioactivity in bone was as high as 3.22{+-}0.68% ID/g at 2 hours after injection. Scintigraphic images of {sup 99m}Tc-incadronate in normal rats revealed highly selective skeletal uptake. {sup 99m}Tc-incadronate exhibited high uptake in bone, and relatively low uptake in soft tissue, suggesting that it may be useful as a bone-seeking agent for judgment of the therapeutic effect of incadronate on

  13. Theory of the induction of bone sarcoma by bone-seeking alpha emitters and its application to risk assessment

    Energy Technology Data Exchange (ETDEWEB)

    Petojan, I.M.

    1992-06-01

    This work discusses the theory of bone sarcoma induction by bone seeking alpha emitters, which is based strictly on biological considerations relative to the mechanism of radiation-induced carcinogenesis, identification of cells at risk and their location in bone, bone tissue renewal processes and bone cell kinetics with or without radiation exposure. The model is consistent with the data on bone sarcoma incidence human with incorporated long-lived isotopes Ra-226 + Ra-228. Extrapolation of these data to a low intake region of the basis of the developed theoretical approach suggests that the linear ICRP-UNSCEAR model overestimates carciogenic risk at low doses, possibly by a factor of 2-4. The model suggests a linear response of target cells to the initiation effects of alpha irradiation. The non-linear (linear-quadratic) initial part of dose-response curve for osteosarcoma induction is explained quantitatively by a model based on a promoter effect of regenerative hyperplasia resulting from invitation effects of alpha radiation. The maximum overestimation inherent to the model of the low-level risk due to the the dose-dependent promotion factor is estimated using bo{sup +1}/bo, where bo is a model parameter which is proportional to the normal division rate of osteogenic cells in vivo and which can be estimated within the framework of the model. The model provides confirming evidence that, for radiation protection purposes, endosteal cells may be considered the only group of cells at risk of sarcoma induction by low doses of bone-seeking alpha emitters, whereas the role of marrow stromal (osteogenic) cells as target cells is much more significant with increasing intakes, and can become dominating if intake is high enough.

  14. Thorium and actinium polyphosphonate compounds as bone-seeking alpha particle-emitting agents.

    Science.gov (United States)

    Henriksen, Gjermund; Bruland, Oyvind S; Larsen, Roy H

    2004-01-01

    The present study explores the use of alpha-particle-emitting, bone-seeking agents as candidates for targeted radiotherapy. Actinium and thorium 1,4,7,10 tetraazacyclododecane N,N',N'',N''' 1,4,7,10-tetra(methylene) phosphonic acid (DOTMP) and thorium-diethylene triamine N,N',N'' penta(methylene) phosphonic acid (DTMP) were prepared and their biodistribution evaluated in conventional Balb/C mice at four hours after injection. All three bone-seeking agents showed a high uptake in bone and a low uptake in soft tissues. Among the soft tissue organs, only kidney had a relatively high uptake. The femur/kidney ratios for 227Th-DTMP, 228-Ac-DOTMP and 227Th-DOTMP were 14.2, 7.6 and 6.0, respectively. A higher liver uptake of 228Ac-DOTMP was seen than for 227Th-DTMP and 227Th-DOTMP. This suggests that some demetallation of the 228Ac-DOTMP complex had occurred. The results indicate that 225Ac-DOTMP, 227Th-DOTMP and 227Th-DTMP have promising properties as potential therapeutic bone-seeking agents.

  15. Accumulation of 99m TC-methylene diphosphonate radiotracer in ...

    African Journals Online (AJOL)

    Accumulation of 99m TC-methylene diphosphonate radiotracer in rat's forelimb. ... by gamma camera 2 h after the injection of 99mTc-MDP via the tail vein. ... can be used for survey radioactivity examination in different bones of the forelimb.

  16. In vivo measurements of bone-seeking radionuclides. Progress report, September 1, 1977--February 28, 1979

    Energy Technology Data Exchange (ETDEWEB)

    Cohen, N.

    1978-11-01

    Progress is reported on the following research projects: estimation of the skeletal burden of bone-seeking radionuclides from in vivo scintillation measurements of their content in the skull; contribution from radionuclides in the thoracic skeleton to in vivo measurements of activity in the lung; design and optimization characterictics of in vivo detection system; development of a calibration phantom structure for determining activity deposited in the thoracic skeleton; computer assisted in vivo measurements of internally deposited radionuclides using dual-crystal scintillation detectors; low energy, photon-emitting nuclides; reference spectra library; and in vivo measurements of exposed individuals. (HLW)

  17. 整合素受体靶向显像诊断乳腺癌溶骨性转移%Imaging of osteolytic bone metastasis from breast cancer with new integrin αvβ3 receptor targeted radiotracer

    Institute of Scientific and Technical Information of China (English)

    邵国强; 赵有财; 崔璨; 梁凯; 孙晋; 杨瑞; 王峰

    2015-01-01

    Objective To investigate the value of integrin αvβ3 targeted micro positron emission tomography (microPET)/CT imaging with 68 Ca-1,4,7,10-tetraazacyclododecane-N,N',N",N"'-tetraacetic acid-arginine-glycine-aspartate peptide dimer (68 Ga-DOTA-RGD2) as radiotracer for the detection of breast cancer osteolytic bone metastases.Methods 68 Ga-DOTA-RGD2 was prepared via one-step method at 100 ℃ for 15 min.Animal model with parathyroid hormone (PTH)-induced osteolysis in the calvarium was established and served as PTH group (BP).Biodistribution study of 68 Ga-DOTA-RGD2 was carried out in BP.Integrin receptor block study was done with pre-injection of high dose of DOTA-RGD2.68Ga-DOTA-RGD2 and 18F-NaF micmPET/CT imaging were perfromed respectively.Breast cancer osteolyic bone metastases was established via intrcardial injection of breast cancer cells.68 Ga-DOTA-RGD2 microPET/CT imaging were perfromed for the detection of breast cancer osetolytic bone metastases.Animals were sarcrificed and bone lesions were harvested for pathological examination.Results 68 Ga-DOTA-RGD2 was stable in vitro and its radiopurity was as high as (96.4 ± 2.1) % 3 h after its preparation.Its blood elimination was fast while its uptake by the liver and kidneys were relativelylow.It was discharged soon after its intravenous injection.In the BP group,regional uptake of 68 Ga-DOTA-RGD2 in osteolytic lesion of calvarium (% ID/g) reached peak (5.14 ±0.65) 60 min after tail vein injection.It was significantly more than that in BC group (2.06 ±0.35,t =7.81,P <0.05).Bone radiotracer uptake ratio of osteolytic lesion to normal calvrium (O/N) was compared based microPET/CT imaging.Bone O/N of 68Ga-DOTA-RGD2 was (6.10 ± 0.97),significantly greater than that of 18F-NaF (1.20 ±0.33,t =10.17,P <0.05).68Ga-DOTA-RGD2 microPET/CT imaging was able to demonstrate the ostelytic bone metastasis in calvarium,thoracic vertebrae and lung metastasis.They were confirmed by pathology results.Conclusion 68 Ga

  18. Development and biological evaluation of {sup 90}Y-BPAMD as a novel bone seeking therapeutic agent

    Energy Technology Data Exchange (ETDEWEB)

    Rabiei, Ali; Shamsaei, Mojtaba [Amir Kabir University of Technology, Tehran (Iran, Islamic Republic of). Energy Engineering and Physics Dept.; Yousefnia, Hassan; Zolghadri, Samaneh; Jalilian, Amir Reza [Nuclear Science and Technology Research Institute (NSTRI), Tehran (Iran, Islamic Republic of); Enayati, Razieh [Islamic Azad Univ. (IAU), Tehran (Iran, Islamic Republic of). Faculty of Engineering

    2016-07-01

    Nowadays, the bone-seeking radiopharmaceuticals play an important role in the treatment of the bone-related pathologies. Whereas various phosphonate ligands have already been identified, a DOTA-based bisphosphonate, 4-{[(bis(phosphonomethyl))carbamoyl]methyl}-7,10-bis(carboxymethyl) -1,4,7,10-tetraazacyclododec-1-yl (BPAMD) with better characteristics has recently been synthesized. In this study, {sup 90}Y-BPAMD was developed with radiochemical purity >98% and the specific activity of 3.52 TBq/mmol in the optimized conditions as a new bone-seeking therapeutic agent. The complex demonstrated significant stability at room temperature and in human serum even after 48 h. At even low amount of hydroxyapatite (5 mg), more than 90% binding to hydroxyapatite was observed. Biodistribution studies after injection of the complex into the Syrian rats showed major accumulation of the labelled compound in the bone tissue and an insignificant uptake in the other organs all the times after injection. Generally, {sup 90}Y-BPAMD demonstrated interesting characteristics compared to the other {sup 90}Y bone-seeking agents and even {sup 166}Ho-BPAMD, and can be considered as a new bone-seeking candidate for therapeutic applications.

  19. Injected radiotracer techniques in hydrology

    Science.gov (United States)

    Rao, S. M.

    1984-08-01

    Radioactive tracers which have several advantages over conventional tracers made significant contributions to the development of the injected tracer method in hydrology. A review of the nuclear and the physico-chemical characteristics of the possible radiotracer compounds leads us to conclude that the most effective groundwater tracers are tritiated water (HTO),82Br- and58Co or60Co as a hexacyanocobaltate complex. A discussion of the various case studies in India and abroad covering the three groups of applications mentioned helps us to conclude that well established radiotracer methods with associated interpretational techniques are available for many short range studies in surface and subsurface hydrology.

  20. The Heritage of Radiotracers for PET

    Science.gov (United States)

    Fowler, J. S.; Wolf, A. P.

    1988-05-01

    The history of PET research clearly demonstrates that it is advances in chemistry coupled with a detailed examination of the biochemistry of new radiotracers which has allowed the PET method to be applied to new areas of biology and medicine. Radiotracers whose regional distribution reflects glucose metabolism, neutrotransmitter activity and enzyme activity have all required the development of rapid synthetic methods for the radiotracers themselves and the characterization of their biochemical behavior. This article traces some of the advances in the production of labeled precursors and in radiotracer synthesis and evaluation which have shaped the rapidly expanding application of PET to problems in the neurosciences, in cardiology and in oncology.

  1. Residual ridge dimensions at edentulous maxillary first molar sites and periodontal bone loss among two ethnic cohorts seeking tooth replacement.

    Science.gov (United States)

    Acharya, Aneesha; Hao, Jia; Mattheos, Nikos; Chau, Anson; Shirke, Prashant; Lang, Niklaus P

    2014-12-01

    To study residual ridge dimensions at edentulous first molar sites in relation to periodontal bone loss among cohorts of partially edentulous Asian Indian and Hong Kong Chinese subjects seeking tooth replacement. A total of 628 edentulous maxillary first molar sites were analyzed on Cone Beam Computed Tomography scans of 225 Asian Indian (I) and 232 Hong Kong Chinese (C) partially edentulous adults seeking tooth replacement. Age, ethnicity, gender, total tooth loss, the presence or absence of adjacent teeth, categories of periodontal status defined according to radiographic alveolar bone loss (P0: periodontal health, P1: incipient to moderate disease, P2: severe periodontal disease) and sinus membrane abnormalities were noted. Alveolar ridge height (RH), widths at 1 and 3 mm from crest (RW1; RW3), and relative position of the bone crest (RR) were measured. Prevalence of P2 status was most frequent in both cohorts(C: 50.4% I: 49.2%). P2 had lowest ridge heights; 13.1% C P2 and 14%I P2 had RH Sinus membrane abnormalities were most frequent in P2. Periodontal status and sinus membrane abnormality increased the odds of RH sinus membrane thickening affected available bone height in the subsinus region, while the presence of adjacent teeth- and age-affected residual ridge width. © 2013 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

  2. A philosophy for CNS radiotracer design.

    Science.gov (United States)

    Van de Bittner, Genevieve C; Ricq, Emily L; Hooker, Jacob M

    2014-10-21

    Decades after its discovery, positron emission tomography (PET) remains the premier tool for imaging neurochemistry in living humans. Technological improvements in radiolabeling methods, camera design, and image analysis have kept PET in the forefront. In addition, the use of PET imaging has expanded because researchers have developed new radiotracers that visualize receptors, transporters, enzymes, and other molecular targets within the human brain. However, of the thousands of proteins in the central nervous system (CNS), researchers have successfully imaged fewer than 40 human proteins. To address the critical need for new radiotracers, this Account expounds on the decisions, strategies, and pitfalls of CNS radiotracer development based on our current experience in this area. We discuss the five key components of radiotracer development for human imaging: choosing a biomedical question, selection of a biological target, design of the radiotracer chemical structure, evaluation of candidate radiotracers, and analysis of preclinical imaging. It is particularly important to analyze the market of scientists or companies who might use a new radiotracer and carefully select a relevant biomedical question(s) for that audience. In the selection of a specific biological target, we emphasize how target localization and identity can constrain this process and discuss the optimal target density and affinity ratios needed for binding-based radiotracers. In addition, we discuss various PET test-retest variability requirements for monitoring changes in density, occupancy, or functionality for new radiotracers. In the synthesis of new radiotracer structures, high-throughput, modular syntheses have proved valuable, and these processes provide compounds with sites for late-stage radioisotope installation. As a result, researchers can manage the time constraints associated with the limited half-lives of isotopes. In order to evaluate brain uptake, a number of methods are available

  3. Radiotracers for SPECT imaging. Current scenario and future prospects

    Energy Technology Data Exchange (ETDEWEB)

    Adak, S.; Vijaya Raj, K.K.; Mandal, S. [GE Healthcare Medical Diagnostics, John F. Welch Technology Center, Bangalore (India).; Bhalla, R.; Pickett, R.; Luthra, S.K. [GE Healthcare Medical Diagnostics, The Grove Centre, Amersham (United Kingdom)

    2012-07-01

    Single photon emission computed tomography (SPECT) has been the cornerstone of nuclear medicine and today it is widely used to detect molecular changes in cardiovascular, neurological and oncological diseases. While SPECT has been available since the 1980s, advances in instrumentation hardware, software and the availability of new radiotracers that are creating a revival in SPECT imaging are reviewed in this paper. The biggest change in the last decade has been the fusion of CT with SPECT, which has improved attenuation correction and image quality. Advances in collimator design, replacement of sodium iodide crystals in the detectors with cadmium zinc telluride (CZT) detectors as well as advances in software and reconstruction algorithms have all helped to retain SPECT as a much needed and used technology. Today, a wide spectrum of radiotracers is available for use in cardiovascular, neurology and oncology applications. The development of several radiotracers for neurological disorders is briefly described in this review, including [{sup 123}I]FP-CIT (DaTSCAN trademark) available for Parkinson's disease. In cardiology, while technetium-99m labeled tetrofosmin and technetium-99m labeled sestamibi have been well known for myocardial perfusion imaging, we describe a recently completed multicenter clinical study on the use of [{sup 123}I]mIBG (AdreView trademark) for imaging in chronic heart failure patients. For oncology, while bone scanning has been prevalent, newer radiotracers that target cancer mechanisms are being developed. Technetium-99m labeled RGD peptides have been reported in the literature that can be used for imaging angiogenesis, while technetium-99m labeled duramycin has been used to image apoptosis. While PET/CT is considered to be the more advanced technology particularly for oncology applications, SPECT continues to be the modality of choice and the workhorse in many hospitals and nuclear medicine centers. The cost of SPECT instruments also

  4. Metal-ion Speciation in Blood Plasma as a Tool in Predicting the "in vivo" Behaviour of Potential Bone-Seeking Radiopharmaceuticals

    NARCIS (Netherlands)

    Zeevaart, J.R.

    2001-01-01

    In a quest for more effective radiopharmaceuticals for palliation of pain experienced by metastatic bone cancer patients, results obtained with the therapeutic radionuclides 153 SM, 166 Ho and 117mSn complexed to bone-seeking phopsphate ligands are related. As phosphonates are known to enhance the r

  5. Imaging in hearing using radiotracers

    Directory of Open Access Journals (Sweden)

    Berding Georg

    2017-09-01

    Full Text Available Radiotracers offer unique options for brain imaging of functional and molecular processes related to hearing. Such imaging can be applied in a broad spectrum of situations from preclinical research to clinical patient care. Functional imaging to assess activation in brain regions and networks involved in auditory processing uses markers of blood flow or energy-metabolism in well-defined conditions with and without auditory stimulation. Molecular markers can be used in hearing research for example to study changes in inhibitory neurotransmission systems related to hearing loss. For imaging either positron emission tomography (PET or single-photon emission computed tomography (SPECT are employed. Data analysis can encompasses voxel-wise statistical analysis of activation and calculation of quantitative parameters like receptor binding-potentials based on bio-kinetic modeling. Functional imaging has been frequently used in the context of auditory implantation. Before implantation it aims to assess intactness of the central auditory pathway and prognosis. After implantation it is used to improve understanding of the outcome with respect to auditory function and finally speech understanding, e.g. by measuring correlates of central auditory processing and neuroplasticity.

  6. Lymphoid tumours and leukaemia induced in mice by bone-seeking radionucleides.

    Science.gov (United States)

    Loutit, J F; Carr, T E

    1978-03-01

    Single intraperitoneal doses of soluble 90Sr and monomeric 239Pu induced generalized lymphomatosis in laboratory mice. Leukaemogenesis due to soluble 226Ra was more uncertain. Clinical expression was variable, but as a generalization the disease was a lymphosarcoma with haematogenous (leukaemic) spread. Only rarely, unlike the commonly recorded forms of natural and X-ray-induced lymphosarcomas, was the thymus apparently the site of onset. The cell-type was lymphoblastic of undifferentiated null form (not T, not B). The average doses of alpha or beta radiation accumulated in the bone-marrow, the presumed site of induction, were at the time of diagnosis usually more than 2500 rad, but, if the cases occurring after radium or low activities of plutonium are accepted as induced, 300-1500 rad of alpha radiation. Mice converted to chimaeras only rarely exhibited any lymphoma, general or local. Abdominal lymphomas were not numerically increased by these radionucleides (perhaps due to shortening of life-span) though some may have been prematurely induced.

  7. Radiotracers for PETT: new developments and perspectives

    Energy Technology Data Exchange (ETDEWEB)

    Fowler, J.S.; Wolf, A.P.

    1983-01-01

    Radiotracer development with positron emitters has its major focus on problems in the neurosciences. Progress is reviewed for high-level isotope production and labelled precurser synthesis with the medical cyclotron. The study of regional brain glucose metabolism represented the first extension of one of the methods of neurochemical autoradiography to humans and the study of brain protein synthesis and neurotransmitter receptors followed. In a more general sense, one PETT instrumentation will provide resolution in the 5 mm range is already emerging. Research status is reviewed. 103 references. (PSB)

  8. An efficient in vitro method for metabolism studies of F-18 labeled radiotracers using mouse liver S9 fraction

    Energy Technology Data Exchange (ETDEWEB)

    Ryu, E. K.; Choi, Y. S.; Kim, D. H.; Ko, B. H.; Lee, K. H.; Choi, Y.; Kim, B. T. [Samsung Medical Center, Seoul (Korea, Republic of)

    2005-07-01

    Metabolism studies are prerequisite for characterization of novel radiotracers. In this study, in vitro metabolism method using mouse liver S9 fraction was established and evaluated using model radiotracers, and the results were compared with those of in vivo method and in vitro method using liver microsomes. 1-(4-[F-18] fluoro methylbenzyl)- ([F-18]1) and 1-(4-[F-18]fluorobenzyl)-4-phen ylpiperazine ([F-18]2) were synthesized and purified by HPLC. Liver S9 fraction and microsomes were prepared from mice. In the in vivo method, mice were injected with the radiotracer, and the bone and blood were collected at 1, 5, 15, 30 and 60 min postinjection. In the in vitro method, the radiotracer was incubated with either S9 fraction or microsomes in the presence of NADPH. The metabolites were analyzed by radio-TLC. Metabolic defluorination was also measured from the incubation of the metabolites with calcium phosphate. [F-18]1 and [F-18]2 were synthesized in 25-35% yield. In the in vivo method, [F-18]1 underwent severe metabolic defluorination based on the increase of bone uptake with time and appearance of [F-18]fluoride ion on radio-TLC in the blood samples. This result was consistent with the in vitro metabolism using either S9 fraction or microsomes, which showed a significant uptake by calcium phosphate. [F-18]2 was converted into unidentified polar metabolites both in vivo and in vitro. There was no increasing uptake by either bone or calcium phosphate with time. The in vitro metabolism of these radiotracers using S9 fraction gave the similar patterns to those using the blood as well as microsomes. This result demonstrated that liver S9 fraction can be used in place of microsomes as well as the blood for the metabolism studies of radiotracers. Moreover, the use of liver S9 fraction has advantages in that it is easily obtained during the early stage of liver microsomal preparation and contains both microsomal and cytosolic fractions.

  9. Bone-seeking radiopharmaceuticals for treatment of osseous metastases, Part 1: α therapy with 223Ra-dichloride.

    Science.gov (United States)

    Pandit-Taskar, Neeta; Larson, Steven M; Carrasquillo, Jorge A

    2014-02-01

    Metastatic disease to bone is commonly seen in the advanced stages of many cancers. The cardinal symptom, pain, is often the cause of significant morbidity and reduced quality of life. Treatment of bone pain includes nonsteroidal analgesics and opiates; however, long-term use of these drugs is commonly associated with significant side effects, and tolerance is common. External-beam radiation therapy is effective mainly in localized disease sites. Bone-targeting radiopharmaceuticals are beneficial in the management of patients with multiple metastatic lesions. This article focuses on the 3 most commonly used agents: the Food and Drug Administration-approved (89)Sr-chloride, (153)Sm-ethylenediaminetetramethylene phosphonic acid (EDTMP), and (223)Ra-dichloride. We will discuss the physical characteristics, clinical data, dosage, and administration of these agents, including optimal patient selection and toxicity associated with their use. These radioactive agents have proven efficacy in the treatment of painful osseous metastases from prostate cancer and breast cancer. Significant recent advances include use of these agents in combination with chemotherapy and the use of the α emitter (223)Ra-dichloride in prostate cancer, primarily to improve survival and skeletal related events. The review is presented in 2 parts. The first will discuss the characteristics and clinical use of (223)Ra-dichloride, and the second will discuss the β emitters (89)Sr and (153)Sm-EDTMP.

  10. A comparative analysis of pharmacokinetics properties of diagnostic bone-seeking radiopharmaceuticals on the basis of phosphonic acids and technetium-99m

    Science.gov (United States)

    Tishchenko, V. K.; Petriev, V. M.; Smoryzanova, O. A.; Zavestovskaya, I. N.

    2017-01-01

    This work is devoted to comparative research of pharmacokinetics properties of four bone-seeking radiopharmaceuticals (RPP) on the basis of bi- tetra- and penta-phosphonic acids. Biodistribution studies were performed in intact rats after intravenous injections of 99mTc-hydroxyethylidenediphosphonic acid (99mTc-HEDP), 99mTc-oxabiphor (99mTc-OXB), 99mTc-ethylenediaminetetramethylenephosphonic acid (99mTc-EDTMP) or 99mTc-diethylenetriaminopentakis(methylphosphonic acid) (99mTc-PPA). In the structure of the HEDP contains two phosphonic groups, OENTMP and EDTMP – four phosphonic groups, PPA – five phosphonic groups. Radiochemical yield of labeled 99mTc HEDP, OENTMP, EDTMP, PPA is not less than 95%, the radiochemical impurities does not exceed 5%. The investigated compounds have high stability in vivo and selective accumulation in osseous tissue. The highest concentrations of labeled compounds is reached in 3–24 hours after their intravenous injections. The investigated compounds are rapidly excreted from blood and soft organs and tissues mainly through the urinary routes. So present study has showed that these RPP have properties, which making them promising candidates as a diagnostic pharmaceuticals of bone metastases.

  11. Biodistribution studies of bee venom and spider toxin using radiotracers

    Directory of Open Access Journals (Sweden)

    C. M. Yonamine

    2005-03-01

    Full Text Available The use of radiotracers allows the understanding of the bioavailability process, biodistribution, and kinetics of any molecule labelled with an isotope, which does not alter the molecule's biological properties. In this work, technetium-99m and iodine-125 were chosen as radiotracers for biodistribution studies in mice using bee (Apis mellifera venom and a toxin (PnTX2-6 from the Brazilian "armed" spider (Phoneutria nigriventer venom. Incorporated radioactivity was measured in the blood, brain, heart, lung, liver, kidney, adrenal gland, spleen, stomach, testicle, intestine, muscle, and thyroid gland. Results provided the blood kinetic parameter, and different organs distribution rates.

  12. Bone

    Science.gov (United States)

    Helmberger, Thomas K.; Hoffmann, Ralf-Thorsten

    The typical clinical signs in bone tumours are pain, destruction and destabilization, immobilization, neurologic deficits, and finally functional impairment. Primary malignant bone tumours are a rare entity, accounting for about 0.2% of all malignancies. Also benign primary bone tumours are in total rare and mostly asymptomatic. The most common symptomatic benign bone tumour is osteoid osteoma with an incidence of 1:2000.

  13. Preclinical Testing of Novel Radiotracers for Positron Emission Tomography (PET)

    NARCIS (Netherlands)

    van Waarde, Aren; Sijbesma, Jurgen; Doorduin, Janine; Elsinga, Philippus; de Vries, Erik; Glaudemans, Andor; Medema, Jitze; van Zanten, Annie K; Dierckx, Rudi; Ahaus, Cees T B

    2017-01-01

    Preclinical tests of novel radiotracers in experimental animals are required to move tracer candidates from the stage of in vitro testing to the stage of toxicity testing and finally studies in human volunteers. Such preclinical tests are aimed at demonstrating: (1) specific in vivo interaction of

  14. Diagnosing plant pipeline system performance using radiotracer techniques

    Energy Technology Data Exchange (ETDEWEB)

    Kasban, H.; Ali, Elsayed H.; Arafa, H. [Engineering Department, Nuclear Research Center, Atomic Energy Authority, Inshas (Egypt)

    2017-02-15

    This study presents an experimental work in a petrochemical company for scanning a buried pipeline using Tc{sup 99m} radiotracer based on the measured velocity changes, in order to determine the flow reduction along a pipeline. In this work, Tc{sup 99m} radiotracer was injected into the pipeline and monitored by sodium iodide scintillation detectors located at several positions along the pipeline. The flow velocity has been calculated between every two consecutive detectors along the pipeline. Practically, six experiments have been carried out using two different data acquisition systems, each of them being connected to four detectors. During the fifth experiment, a bypass was discovered between the scanned pipeline and another buried parallel pipeline connected after the injection point. The results indicate that the bypass had a bad effect on the volumetric flow rate in the scanned pipeline.

  15. PET Radiotracers for Imaging the Proliferation Status of Breast Tumors

    Science.gov (United States)

    2004-12-01

    The mice were implanted in the scapular region 7 days prior to the study. Animals were injected with 100-150 gCi of the "iC-labeled radiotracer and...preparative HPLC using 17.5 % THF/82.5 % of 0.1M ammonium formate (with 0.1% formic acid) buffer at pH = 4.0 as the mobile phase (flow rate = 4.0 mL/min

  16. Radiotracers for PET and SPECT studies of neurotransmitter systems

    Energy Technology Data Exchange (ETDEWEB)

    Fowler, J.S.

    1991-01-01

    The study of neurotransmitter systems is one of the major thrusts in emission tomography today. The current generation of Positron Emission Tomography (PET) and Single Photon Emission Computed Tomography (SPECT) radiotracers examines neurotransmitter properties from a number of different perspectives including their pre and post synaptic sites and the activity of the enzymes which regulate their concentration. Although the dopamine system has been the most extensively investigated, other neurotransmitter systems including the acetylcholine muscarine, serotonin, benzodiazepine, opiate, NMDA and others are also under intensive development. Enzymes involved in the synthesis and regulation of neurotransmitter concentration, for example monoamine oxidase and amino acid decarboxylase has also been probed in vivo. Medical applications range from the study of normal function and the characterization of neurotransmitter activity in neurological and psychiatric diseases and in heart disease and cancer to the study of the binding of therapeutic drugs and substances of abuse. This chapter will provide an overview of the current generation of radiotracers for PET and SPECT studies of neurotransmitter systems including radiotracer design, synthesis localization mechanisms and applications in emission tomography. 60 refs., 1 tab.

  17. Microleakage Evaluation at Implant-Abutment Interface Using Radiotracer Technique

    Directory of Open Access Journals (Sweden)

    Hakimeh Siadat

    2016-10-01

    Full Text Available Objectives: Microbial leakage through the implant-abutment (I-A interface results in bacterial colonization in two-piece implants. The aim of this study was to compare microleakage rates in three types of Replace abutments namely Snappy, GoldAdapt, and customized ceramic using radiotracing.Materials and Methods: Three groups, one for each abutment type, of five implants and one positive and one negative control were considered (a total of 17 regular body implants. A torque of 35 N/cm was applied to the abutments. The samples were immersed in thallium 201 radioisotope solution for 24 hours to let the radiotracers leak through the I-A interface. Then, gamma photons received from the radiotracers were counted using a gamma counter device. In the next phase, cyclic fatigue loading process was applied followed by the same steps of immersion in the radioactive solution and photon counting.Results: Rate of microleakage significantly increased (P≤0.05 in all three types of abutments (i.e. Snappy, GoldAdapt, and ceramic after cyclic loading. No statistically significant differences were observed between abutment types after cyclic loading.Conclusions: Microleakage significantly increases after cyclic loading in all three Replace abutments (GoldAdapt, Snappy, ceramic. Lowest microleakage before and after cyclic loading was observed in GoldAdapt followed by Snappy and ceramic.Keywords: Dental Implants; Dental Implant-Abutment Design; Thallium Chloride

  18. Extraosseous radiotracer uptake on bone scan in beta-thalassemia: report of one case; Fixation extraosseuse du radiotraceur lors de la realisation d'une scintigraphie du squelette chez un patient atteint de beta-thalassemie: a propos d'un cas

    Energy Technology Data Exchange (ETDEWEB)

    Guezguez, M.; Nouira, M.; Sfar, R.; Chatti, K.; Ben Fradj, M.; Ben Ali, K.; Ajmi, S.; Essabbah, H. [CHU Sahloul, Service de Medecine Nucleaire, Sousse (Tunisia); Zrour, S. [EPS F. Bourguiba, Service de Rhumatologie, Monastir (Tunisia)

    2009-10-15

    Red blood cell transfusion, main therapeutic modality of beta-thalassemia, leads to iron overload which may perturb several metabolic ways. The aim of this paper is to illustrate the uptake abnormalities observed on bone scan of thalassaemic patients and to discuss mechanisms of extraosseous accumulation of the radiopharmaceutical in this pathology. We report a 16-year-old child suffering from beta-thalassemia major undergoing transfusion therapy. A bone scan was indicated to look for osseous infection. This study revealed a little skeletal uptake and abnormal liver, splenic and renal accumulation. A repeat bone scan, performed three weeks later showed a better skeletal uptake which enabled the discovery of focal abnormalities and made the diagnostic easier. The effect of iron overload on radiopharmaceuticals uptake in bone scan is known since 1975. Dissociation of {sup 99m}Tc from the carrier ligand due to the presence of iron excess seems the most plausible hypothesis. Free {sup 99m}Tc can be bound to other tissular substrates which can explain extraosseous uptake. The normally available pool for bone is reduced and then the skeletal uptake decreased. This report limits considerably the sensitivity of the bone scan. A well-led iron chelation and eventually the use of diuretic drug may guarantee a better quality of bone scan images. (authors)

  19. Expertise seeking

    DEFF Research Database (Denmark)

    Hertzum, Morten

    2014-01-01

    Expertise seeking is the activity of selecting people as sources for consultation about an information need. This review of 72 expertise-seeking papers shows that across a range of tasks and contexts people, in particular work-group colleagues and other strong ties, are among the most frequently...... used sources. Studies repeatedly show the influence of the social network – of friendships and personal dislikes – on the expertise-seeking network of organisations. In addition, people are no less prominent than documentary sources, in work contexts as well as daily-life contexts. The relative...... influence of source quality and source accessibility on source selection varies across studies. Overall, expertise seekers appear to aim for sufficient quality, composed of reliability and relevance, while also attending to accessibility, composed of access to the source and access to the source information...

  20. Comparison of two peptide radiotracers for prostate carcinoma targeting

    Directory of Open Access Journals (Sweden)

    Bluma Linkowski Faintuch

    2012-01-01

    Full Text Available OBJECTIVES: Scintigraphy is generally not the first choice treatment for prostate cancer, although successful studies using bombesin analog radiopeptides have been performed. Recently, a novel peptide obtained using a phage display library demonstrated an affinity for prostate tumor cells. The aim of this study was to compare the use of a bombesin analog to that of a phage display library peptide (DUP-1 radiolabeled with technetium-99m for the treatment of prostate carcinoma. The peptides were first conjugated to S-acetyl-MAG3 with a 6-carbon spacer, namely aminohexanoic acid. METHODS: The technetium-99m labeling required a sodium tartrate buffer. Radiochemical evaluation was performed using ITLC and was confirmed by high-performance liquid chromatography. The coefficient partition was determined, and in vitro studies were performed using human prostate tumor cells. Biodistribution was evaluated in healthy animals at various time points and also in mice bearing tumors. RESULTS: The radiochemical purity of both radiotracers was greater than 95%. The DUP-1 tracer was more hydrophilic (log P = -2.41 than the bombesin tracer (log P = -0.39. The biodistribution evaluation confirmed this hydrophilicity by revealing the greater kidney uptake of DUP-1. The bombesin concentration in the pancreas was greater than that of DUP-1 due to specific gastrin-releasing peptide receptors. Bombesin internalization occurred for 78.32% of the total binding in tumor cells. The DUP-1 tracer showed very low binding to tumor cells during the in vitro evaluation, although tumor uptake for both tracers was similar. The tumors were primarily blocked by DUP1 and the bombesin radiotracer primarily targeted the pancreas. CONCLUSION: Further studies with the radiolabeled DUP-1 peptide are recommended. With further structural changes, this molecule could become an efficient alternative tracer for prostate tumor diagnosis.

  1. First ex vivo study demonstrating that {sup 99m}Tc-NTP 15-5 radiotracer binds to human articular cartilage

    Energy Technology Data Exchange (ETDEWEB)

    Cachin, Florent; Culot, Damien [Jean Perrin Cancer Centre, Nuclear Medicine Department, Clermont-Ferrand (France); Universite d' Auvergne, UMR 990 INSERM, Clermont-Ferrand (France); Boisgard, Stephane [Gabriel Montpied University Hospital, Orthopaedic Surgery, Clermont-Ferrand (France); Universite d' Auvergne, UMR 990 INSERM, Clermont-Ferrand (France); Vidal, Aurelien; Auzeloux, Philippe; Madelmont, Jean-Claude; Chezal, Jean-Michel; Miot-Noirault, Elisabeth [Universite d' Auvergne, UMR 990 INSERM, Clermont-Ferrand (France); Filaire, Marc [Universite d' Auvergne, Anatomy Laboratory, Clermont-Ferrand (France); Askienazy, Serge [Cyclopharma Laboratoire, Saint-Beauzire (France)

    2011-11-15

    Preclinical data pointed to {sup 99m}Tc-NTP 15-5 as a good candidate for single photon emission computed tomography (SPECT) imaging of cartilaginous disease. We set out to investigate and quantify {sup 99m}Tc-NTP 15-5 ex vivo uptake by human articular cartilage relative to bone {sup 99m}Tc-hydroxymethylene diphosphonate (HMDP) radiotracer. Three osteoarthritic human tibial plateaux and four tibiofemoral joints were incubated with {sup 99m}Tc-NTP 15-5 and {sup 99m}Tc-HMDP for 2 h. Affinity of tracers for cartilage was determined by visual analysis of SPECT/CT acquisitions and measurement of cartilage to cortical bone uptake ratios. Cartilage to cortical bone uptake ratios were 3.90 {+-} 2.35 and 0.76 {+-} 0.24, respectively, for {sup 99m}Tc-NTP 15-5 and {sup 99m}Tc-HMDP radiotracers. Visual analysis of fused SPECT/CT slices showed selective, intense {sup 99m}Tc-NTP 15-5 accumulation in articular cartilage, whereas {sup 99m}Tc-HMDP binding was low. Interestingly, a cartilage defect visualized on CT was clearly associated with focal decreased uptake of {sup 99m}Tc-NTP 15-5. The tracer {sup 99m}Tc-NTP 15-5 is of major interest for human cartilage molecular imaging and could find clinical applications in osteoarthritis staging and monitoring. (orig.)

  2. Radiotracers For Lipid Signaling Pathways In Biological Systems

    Energy Technology Data Exchange (ETDEWEB)

    Gatley, S. J. [Northeastern Univ., Boston, MA (United States)

    2016-09-26

    The primary focus of this project continues to be the development of radiotracers and radiotracer methodology for studying physiology and biochemistry. The compounds that have been labeled areacylethanolamines and acylglycerols that are, as classes, represented in both in plants and in animals. In the latter, some of these act as ligands for cannabinoid receptors and they are therefore known as endocannabinoids. Cannabinoid receptors are not found in plant genomes so that plants must contain other receptors and signaling systems that use acylethanolamines. Relatively little work has been done on that issue, though acylethanolamines do modulate plant growth and stress resistance, thus possessing obvious relevance to agriculture and energy production. Progress has been described in five peer-reviewed papers and seven meeting abstracts. Preparation of 2-acylglycerol lipid messengers in high purity. A novel enzymatic synthesis was developedthat gave pure 2-acylglycerols free of any rearrrangement to the thermodynamically more stable 1(3)-acylglycerol byproducts. The method utilized 1,3-dibutyryl-2-acylglycerol substrate ethanolysis by a resinimobilized lipase. Thus, pure radiolabeled 2-acylglycerols can now be conveniently prepared just prior to their utilization. These synthetic studies were published in the Journal of Medicinal Chemistry, 2011. Diacylglycerol lipase assay methodology. Diacylglycerol lipases (DAGLs) generate 2- acylglycerols, and are thus potential targets for disease- or growth-modifying agents, by means of reducing formation of 2-acylglycerols. A radioTLC assay of the hydrolysis of radiolabeled diglyceride substrate [1''-carbon-14]2-arachidonoyl-1-stearoyl-sn-glycerol has been implemented, and used to validate a novel, potentially highthroughput fluorescence resonance energy transfer (FRET) based assay. A number of new DAGL inhibitors that have selectivity for DAGLs were synthesized and screened. This work was very recently published in

  3. Cabozantinib Resolves Bone Scans in Tumor-Naïve Mice Harboring Skeletal Injuries

    Directory of Open Access Journals (Sweden)

    Michael G. Doran

    2014-10-01

    Full Text Available The receptor tyrosine kinase inhibitor cabozantinib (XL184, BMS-907351 Cometriq has displayed impressive clinical activity against several indications, culminating in its recent approval for medullary thyroid cancer. Among malignancies with tropism for the bone (prostate, breast, one striking feature of early clinical reports about this drug has been the rapid and complete resolution of bone scans, a phenomenon almost never observed even among therapies already shown to confer survival benefit. In castration-resistant prostate cancer, not all conventional response indicators change as dramatically posttreatment, raising the possibility that cabozantinib may impair the ability of bone-seeking radionuclides to integrate within the remodeling bone. To test this hypothesis, we surgically induced bone remodeling via physical insult in non–tumor-bearing mice and performed 18F-sodium fluoride (18F-NaF positron emission tomographic (PET and technetium 99m–methylene diphosphonate (99mTc-MDP single-photon emission computed tomographic (SPECT scans pre- and posttreatment with cabozantinib and related inhibitors. A consistent reduction in the accumulation of either radiotracer at the site of bone remodeling was observed in animals treated with cabozantinib. Given that cabozantinib is known to inhibit several receptor tyrosine kinases, we drugged animals with various permutations of more selective inhibitors to attempt to refine the molecular basis of bone scan resolution. Neither the vascular endothelial growth factor receptor (VEGFR inhibitor axitinib, the MET inhibitor crizotinib, nor the combination was capable of inhibiting 18F-NaF accumulation at known bioactive doses. In summary, although the mechanism by which cabozantinib suppresses radionuclide incorporation into foci undergoing bone remodeling remains unknown, that this phenomenon occurs in tumor-naïve models indicates that caution should be exercised in interpreting the clinical significance

  4. The uses of radiotracers in the life sciences

    Science.gov (United States)

    Ruth, Thomas J.

    2009-01-01

    Radionuclides have been used to follow physical, chemical and biological processes almost from the time of their discovery. Probably the application with the biggest impact has been in the medical field where radionuclides have been incorporated into biologically active molecules and used to diagnose a wide variety of diseases and to treat many disorders. Other uses in the life sciences, in general, are related to using a radioactive isotope as marker for an existing species such as nitrogen-13 in plant studies or copper-67 to track copper catalysts in phytoplankton. This review describes in general terms these uses as well as providing the reader with the background related to the physical properties of radioactive decay, the concepts associated with the production of radionuclides using reactors or accelerators and the fundamentals of imaging radioactivity. The advances in imaging technology in recent years has had a profound impact on the use of radionuclides in positron emission tomography and the coupling of other imaging modalities to provide very precise insights into human disease. The variety of uses for radiotracers in science is almost boundless dependent only upon ones imagination.

  5. Hydrophilic actinide complexation studied by solvent extraction radiotracer technique

    Energy Technology Data Exchange (ETDEWEB)

    Rydberg, J. [Chalmers Univ. of Technology, Goeteborg (Sweden). Dept. of Nuclear Chemistry and Radiochemistry Consultant Group, Vaestra Froelunda (Sweden)

    1996-10-01

    Actinide migration in the ground water is enhanced by the formation of water soluble complexes. It is essential to the risk analysis of a wet repository to know the concentration of central atoms and the ligands in the ground water, and the stability of complexes formed between them. Because the chemical behavior at trace concentrations often differ from that at macro concentrations, it is important to know the chemical behavior of actinides at trace concentrations in ground water. One method used for such investigations is the solvent extraction radiotracer (SXRT) technique. This report describes the SXRT technique in some detail. A particular reason for this analysis is the claim that complex formation constants obtained by SXRT are less reliable than results obtained by other techniques. It is true that several difficulties are encountered in the application of SXRT technique to actinide solution, such as redox instability, hydrophilic complexation by side reactions and sorption, but it is also shown that a careful application of the SXRT technique yields results as reliable as by any other technique. The report contains a literature survey on solvent extraction studies of actinide complexes formed in aqueous solutions, particularly by using the organic reagent thenoyltrifluoroacetone (TTA) dissolved in benzene or chloroform. Hydrolysis constants obtained by solvent extraction are listed as well as all actinide complexes studied by SX with inorganic and organic ligands. 116 refs, 11 tabs.

  6. Receptor-binding radiotracers: a class of potential radiopharmaceuticals

    Energy Technology Data Exchange (ETDEWEB)

    Eckelman, W.C.; Reba, R.C.; Gibson, R.E.; Rzeszotarski, W.J.; Vieras, F.; Mazaitis, J.K.; Francis, B.

    1979-04-01

    To date no radiopharmaceutical is routinely used to study changes in receptor concentration. Frequently changes in receptor concentration, or the appearance of receptors in tumors, indicates a specific pathologic state. With a receptor-binding radiotracer, in vivo studies of these changes will be possible. A reversible bimolecular model and in vitro tests were used to determine equilibrium constants and maximal target-to-blood ratios for new derivatives. Theoretical calculations showed that derivatives binding to the estrogen receptor, the beta adrenoceptor, or the cholinergic receptor are capable of achieving satisfactory target-to-blood ratios. Using in vitro tests, the apparent affinity constant was determined for five iodinated estrogen derivatives and five derivatives of beta blockers. Results of the in vitro study with derivatives of beta blockers. Results of the in vitro study with derivatives of beta blockers, and in vivo displacement studies using propranolol, indicated that the high heart-to-blood ratios (5 to 20) obtained with the new derivatives were not the result of a specific interaction with the receptor. In this instance factors other than receptor binding control the in vivo distribution. The in vitro assay using estrogen receptors showed that of the five derivatives, iodohexestrol and 17-alpha-iodoethynylestradiol bind to the receptor with the highest affinity. In vivo studies confirmed these results; iodohexestrol gave a uterus-to-blood ratio of 10 in immature rats when plasma-protein binding was blocked. With a tritiated muscarinic cholinergic blocking agent, heart-to-blood ratios near the theoretical maximum were obtained. This compound most closely follows the mechanism described by the model. Use of the theoretical model in conjunction with in vitro assays can greatly aid in the design of this new class of receptor-binding radiopharmaceuticals.

  7. Radiotracers For Lipid Signaling Pathways In Biological Systems

    Energy Technology Data Exchange (ETDEWEB)

    Gatley, S. J. [Northeastern Univ., Boston, MA (United States)

    2016-09-26

    The primary focus of this project continues to be the development of radiotracers and radiotracer methodology for studying physiology and biochemistry. The compounds that have been labeled areacylethanolamines and acylglycerols that are, as classes, represented in both in plants and in animals. In the latter, some of these act as ligands for cannabinoid receptors and they are therefore known as endocannabinoids. Cannabinoid receptors are not found in plant genomes so that plants must contain other receptors and signaling systems that use acylethanolamines. Relatively little work has been done on that issue, though acylethanolamines do modulate plant growth and stress resistance, thus possessing obvious relevance to agriculture and energy production. Progress has been described in five peer-reviewed papers and seven meeting abstracts. Preparation of 2-acylglycerol lipid messengers in high purity. A novel enzymatic synthesis was developedthat gave pure 2-acylglycerols free of any rearrrangement to the thermodynamically more stable 1(3)-acylglycerol byproducts. The method utilized 1,3-dibutyryl-2-acylglycerol substrate ethanolysis by a resinimobilized lipase. Thus, pure radiolabeled 2-acylglycerols can now be conveniently prepared just prior to their utilization. These synthetic studies were published in the Journal of Medicinal Chemistry, 2011. Diacylglycerol lipase assay methodology. Diacylglycerol lipases (DAGLs) generate 2- acylglycerols, and are thus potential targets for disease- or growth-modifying agents, by means of reducing formation of 2-acylglycerols. A radioTLC assay of the hydrolysis of radiolabeled diglyceride substrate [1''-carbon-14]2-arachidonoyl-1-stearoyl-sn-glycerol has been implemented, and used to validate a novel, potentially highthroughput fluorescence resonance energy transfer (FRET) based assay. A number of new DAGL inhibitors that have selectivity for DAGLs were synthesized and screened. This work was very recently published in

  8. A study of residence time distribution using radiotracer technique in the large scale plant facility

    Science.gov (United States)

    Wetchagarun, S.; Tippayakul, C.; Petchrak, A.; Sukrod, K.; Khoonkamjorn, P.

    2017-06-01

    As the demand for troubleshooting of large industrial plants increases, radiotracer techniques, which have capability to provide fast, online and effective detections to plant problems, have been continually developed. One of the good potential applications of the radiotracer for troubleshooting in a process plant is the analysis of Residence Time Distribution (RTD). In this paper, the study of RTD in a large scale plant facility using radiotracer technique was presented. The objective of this work is to gain experience on the RTD analysis using radiotracer technique in a “larger than laboratory” scale plant setup which can be comparable to the real industrial application. The experiment was carried out at the sedimentation tank in the water treatment facility of Thailand Institute of Nuclear Technology (Public Organization). Br-82 was selected to use in this work due to its chemical property, its suitable half-life and its on-site availability. NH4Br in the form of aqueous solution was injected into the system as the radiotracer. Six NaI detectors were placed along the pipelines and at the tank in order to determine the RTD of the system. The RTD and the Mean Residence Time (MRT) of the tank was analysed and calculated from the measured data. The experience and knowledge attained from this study is important for extending this technique to be applied to industrial facilities in the future.

  9. Distributed Microprocessor Automation Network for Synthesizing Radiotracers Used in Positron Emission Tomography [PET

    Science.gov (United States)

    Russell, J. A. G.; Alexoff, D. L.; Wolf, A. P.

    1984-09-01

    This presentation describes an evolving distributed microprocessor network for automating the routine production synthesis of radiotracers used in Positron Emission Tomography. We first present a brief overview of the PET method for measuring biological function, and then outline the general procedure for producing a radiotracer. The paper identifies several reasons for our automating the syntheses of these compounds. There is a description of the distributed microprocessor network architecture chosen and the rationale for that choice. Finally, we speculate about how this network may be exploited to extend the power of the PET method from the large university or National Laboratory to the biomedical research and clinical community at large. (DT)

  10. Comparative analysis of 11 different radioisotopes for palliative treatment of bone metastases by computational methods

    Energy Technology Data Exchange (ETDEWEB)

    Guerra Liberal, Francisco D. C., E-mail: meb12020@fe.up.pt, E-mail: adriana-tavares@msn.com; Tavares, Adriana Alexandre S., E-mail: meb12020@fe.up.pt, E-mail: adriana-tavares@msn.com; Tavares, João Manuel R. S., E-mail: tavares@fe.up.pt [Instituto de Engenharia Mecânica e Gestão Industrial, Faculdade de Engenharia, Universidade do Porto, Rua Dr. Roberto Frias s/n, Porto 4200-465 (Portugal)

    2014-11-01

    Purpose: Throughout the years, the palliative treatment of bone metastases using bone seeking radiotracers has been part of the therapeutic resources used in oncology, but the choice of which bone seeking agent to use is not consensual across sites and limited data are available comparing the characteristics of each radioisotope. Computational simulation is a simple and practical method to study and to compare a variety of radioisotopes for different medical applications, including the palliative treatment of bone metastases. This study aims to evaluate and compare 11 different radioisotopes currently in use or under research for the palliative treatment of bone metastases using computational methods. Methods: Computational models were used to estimate the percentage of deoxyribonucleic acid (DNA) damage (fast Monte Carlo damage algorithm), the probability of correct DNA repair (Monte Carlo excision repair algorithm), and the radiation-induced cellular effects (virtual cell radiobiology algorithm) post-irradiation with selected particles emitted by phosphorus-32 ({sup 32}P), strontium-89 ({sup 89}Sr), yttrium-90 ({sup 90}Y ), tin-117 ({sup 117m}Sn), samarium-153 ({sup 153}Sm), holmium-166 ({sup 166}Ho), thulium-170 ({sup 170}Tm), lutetium-177 ({sup 177}Lu), rhenium-186 ({sup 186}Re), rhenium-188 ({sup 188}Re), and radium-223 ({sup 223}Ra). Results: {sup 223}Ra alpha particles, {sup 177}Lu beta minus particles, and {sup 170}Tm beta minus particles induced the highest cell death of all investigated particles and radioisotopes. The cell survival fraction measured post-irradiation with beta minus particles emitted by {sup 89}Sr and {sup 153}Sm, two of the most frequently used radionuclides in the palliative treatment of bone metastases in clinical routine practice, was higher than {sup 177}Lu beta minus particles and {sup 223}Ra alpha particles. Conclusions: {sup 223}Ra and {sup 177}Lu hold the highest potential for palliative treatment of bone metastases of all

  11. Nurse exposure doses resulted from bone scintigraphy patient

    Science.gov (United States)

    Tunçman, Duygu; Kovan, Bilal; Poyraz, Leyla; ćapali, Veli; Demir, Bayram; Türkmen, Cüneyt

    2016-03-01

    Bone scintigraphy is used for displaying the radiologic undiagnosed bone lesions in nuclear medicine. It's general indications are researching bone metastases, detection of radiographically occult fractures, staging and follow-up in primary bone tumors, diagnosis of paget's disease, investigation of loosening and infection in orthopedic implants. It is applied with using 99mTc labeled radiopharmaceuticals (e.g 99m Tc MDP,99mTc HEDP and 99mTc HMDP). 20 -25 mCi IV radiotracer was injected into vein and radiotracer emits gamma radiation. Patient waits in isolated room for about 3 hours then a gamma camera scans radiation area and creates an image. When some patient's situation is not good, patients are hospitalized until the scanning because of patients' close contact care need. In this study, measurements were taken from ten patients using Geiger Muller counter. After these measurements, we calculated nurse's exposure radiations from patient's routine treatment, examination and emergency station.

  12. Use of supercritical carbon dioxide fluid as a solvent for the purification of pet radiotracers

    Energy Technology Data Exchange (ETDEWEB)

    Ferrieri, R.A.; Fowler, J.S.; Wolf, A.P.

    1993-12-31

    We have identified superfluid chromatography (SFC) as a promising method which could offer advantages in radiotracer purification through rapid separation, as well as, improved recovery and purity of labeled product. Using SF CO{sub 2} as the mobile phase for chromatographic separation of labeled product would eliminate the need for solvent removal from product prior to delivery.

  13. Increasing the accuracy of radiotracer monitoring in one-dimensional flow using polynomial deconvolution correction.

    Science.gov (United States)

    Gholipour Peyvandi, Reza; Taheri, Ali

    2016-01-01

    Factors such as type of fluid movement and gamma-ray scattering may decrease the precision of the radiotracer monitoring as the response to a short tracer injection. Practical experiences using polynomial deconvolution techniques are presented. These techniques were successfully applied for correcting the obtained experimental results and increasing the time resolution of the method. Copyright © 2015 Elsevier Ltd. All rights reserved.

  14. Collaborative information seeking

    DEFF Research Database (Denmark)

    Hertzum, Morten

    2008-01-01

    , the activities involved in information seeking are often performed by varying subgroups of actors. Consequently, collaborative grounding is necessary to share information among collaborating actors and, thereby, establish and maintain the common ground necessary for their collaborative work. By focusing......Since common ground is pivotal to collaboration, this paper proposes to define collaborative information seeking as the combined activity of information seeking and collaborative grounding. While information-seeking activities are necessary for collaborating actors to acquire new information...... on the collaborative level, collaborative information seeking aims to avoid both individual reductionism and group reductionism, while at the same time recognizing that only some information and understanding need be shared....

  15. Synthesis of carbon-11, fluorine-18, and nitrogen-13 labeled radiotracers for biomedical applications

    Energy Technology Data Exchange (ETDEWEB)

    Fowler, J.S.; Wolf, A.P.

    1981-01-01

    A number of reviews, many of them recent, have appeared on various aspects of /sup 11/C, /sup 18/F and /sup 13/N-labeled radiotracers. This monograph treats the topic principally from the standpoint of synthetic organic chemistry while keeping in perspective the necessity of integrating the organic chemistry with the design and ultimate application of the radiotracer. Where possible, recent examples from the literature of organic synthesis are introduced to suggest potentially new routes which may be applied to problems in labeling organic molecules with the short-lived positron emitters, carbon-11, fluorine-18, and nitrogen-13. The literature survey of carbon-11, fluorine-18 and nitrogen-13 labeled compounds presented are of particular value to scientists working in this field. Two appendices are also included to provide supplementary general references. A subject index concludes this volume.

  16. (68) Ga-labeled Ciprofloxacin Conjugates as Radiotracers for Targeting Bacterial Infection.

    Science.gov (United States)

    Satpati, Drishty; Arjun, Chanda; Krishnamohan, Repaka; Samuel, Grace; Banerjee, Sharmila

    2016-05-01

    With an aim of developing a bacteria-specific molecular imaging agent, ciprofloxacin has been modified with a propylamine spacer and linked to two common bifunctional chelators, p-SCN-Bz-DOTA and p-SCN-Bz-NOTA. The two ciprofloxacin conjugates, CP-PA-SCN-Bz-DOTA (1) and CP-PA-SCN-Bz-NOTA (2), were radiolabeled with (68)Ga in >90% radiochemical yield and were moderately stable in vitro for 4 h. The efficacy of (68)Ga-1 and (68)Ga-2 has been investigated in vitro in Staphylococcus aureus cells where bacterial binding of the radiotracers (0.9-1.0% for (68)Ga-1 and 1.6-2.3% for (68)Ga-2) could not be blocked in the presence of excess amount of unlabeled ciprofloxacin. However, uptake of radiotracers in live bacterial cells was significantly higher (p 68)Ga-1 and (68)Ga-2 was tested in vivo in rats where the infected muscle-to-inflamed muscle ((68)Ga-1: 2 ± 0.2, (68)Ga-2: 3 ± 0.5) and infected muscle-to-normal muscle ratios ((68)Ga-1: 3 ± 0.4, (68)Ga-2: 6.6 ± 0.8) were found to improve at 120 min p.i. Fast blood clearance and renal excretion was observed for both the radiotracers. The two (68)Ga-labeled infection targeting radiotracers could discriminate between bacterial infection and inflammation in vivo and are worthy of further detailed investigation as infection imaging agents at the clinical level.

  17. Investigation of liquid phase axial dispersion in Taylor bubble flow by radiotracer residence time distribution analysis

    Directory of Open Access Journals (Sweden)

    Jin J.H.

    2013-05-01

    Full Text Available A gas-liquid Taylor bubble flow occurs in small diameter channels in which gas bubbles are separated by slugs of pure liquid. This type of flow regime is well suited for solid catalyzed gas-liquid reactors in which the reaction efficiency is a strong function of axial dispersion in the regions of pure liquid. This paper presents an experimental study of liquid phase axial dispersion in a Taylor bubble flow developed in a horizontal tube using high speed photography and radiotracer residence time distribution (RTD analysis. A parametric dependence of axial dispersion on average volume fraction of gas phase was also investigated by varying the relative volumetric flow rates of the two phases. 137mBa produced from a 137Cs/137mBa radionuclide generator was used as radiotracer and measurements were made using the NaI(Tl scintillation detectors. Validation of 137mBa in the form of barium chloride as aqueous phase radiotracer was also carried out. Axial Dispersion Model (ADM was used to simulate the hydrodynamics of the system and the results of the experiment are presented. It was observed that the system is characterized by very high values of Peclet Number (Pe∼102 which reveals an approaching plug type flow. The experimental and model estimated values of mean residence times were observed in agreement with each other.

  18. Prediction of Separation Length of Turbulent Multiphase Flow Using Radiotracer and Computational Fluid Dynamics Simulation

    Directory of Open Access Journals (Sweden)

    S. Sugiharto1

    2013-04-01

    Full Text Available Multiphase flow modeling presents great challenges due to its extreme importance in various industrial and environmental applications. In the present study, prediction of separation length of multiphase flow is examined experimentally by injection of two kinds of iodine-based radiotracer solutions into a hydrocarbon transport pipeline (HCT having an inner diameter of 24 in (60,96 m. The main components of fluids in the pipeline are water 95%, crude oil 3% and gas 2%. A radiotracing experiment was carried out at the segment of pipe which is located far from branch points with assumptions that stratified flows in such segment were achieved. Two radiation detectors located at 80 and 100 m from injection point were used to generate residence time distribution (RTD curve resulting from injection of radiotracer solutions. Multiphase computational fluid dynamics (CFD simulations using Eulerian-Eulerian control volume and commercial CFD package Fluent 6.2 were employed to simulate separation length of multiphase flow. The results of study shows that the flow velocity of water is higher than the flow rate of crude oil in water-dominated system despite the higher density of water than the density of the crude oil. The separation length in multiphase flow predicted by Fluent mixture model is approximately 20 m, measured from injection point. This result confirms that the placement of the first radiation detector at the distance 80 m from the injection point was correct

  19. The Expanding Reach of Environmental Radiotracers - New Chronometers And More Sensitive Measurements

    Science.gov (United States)

    Aalseth, C.

    2015-12-01

    Radiotracers in the environment provide powerful tools for understanding environmental processes. Viewed as an age continuum, methods using shorter-lived radionuclides (1,000 y) like 10Be, 14C, 36Cl, and 81Kr generally rely on atom-counting measurements such as accelerator mass spectrometry. Significant challenges exist in the age range between 100 and 1,000 years where useful radiotracers are difficult to measure by either method and can have very low abundance. These challenges are being addressed with more sensitive measurements using both atom counting and radioactive decay, extending the reach of established radiotracers as well as adding new chronometers. Improvements in atom-counting methods will be reviewed; the practicality of using 81Kr (abundance ~5×10-13 in atmospheric krypton) for age-dating old aquifers has been established and current work focuses on improving sample utilization efficiency to allow smaller samples to be measured. Better efficiency also brings lower-abundance isotopes within reach, for example 39Ar. Improvements in radioactive decay counting will be reviewed; these take advantage of ultra-pure materials to achieve lower backgrounds and are adding new age-dating reach to the environmental science tool-set with intermediate half-life radionuclides, for example 32Si for sediment cores. These methods also improve sensitivity for established radiotracers like 3H and will allow smaller samples to be measured, allowing specific processes to be traced. For example, using 3H as an indicator of carbon cycling through organic compounds in soil systems. Progress in both atom counting and decay counting is expanding the use of 39Ar for age-dating aquifers, measuring ocean mixing, and age-dating younger glacial ice. Argon-39 is a challenging intermediate-age radiotracer (269-year half-life) with low abundance (~8×10-16 in atmospheric argon). New decay counting capabilities have expanded worldwide capacity for 39Ar aquifer measurements, while

  20. Newcomer information seeking

    DEFF Research Database (Denmark)

    Moring, Camilla Elisabeth

    2017-01-01

    Introduction: Research on socialization and learning processes among organizational newcomers is offering valuable insight into the role of information seeking in the workplace, and to why, and how newcomers seek information when entering a new organization. Analysis: The aim of the paper...... is to outline and discuss the significance of information seeking in newcomer socialization and learning, and analyse how different approaches influence our understanding of the role of information seeking in the workplace. Results: It is argued, that a development in research on newcomer information seeking...... in organizations newcomers access to participate and negotiate meaning in practice becomes essential. Information seeking hereby plays a significant role in newcomers learning by establishing, developing, and maintaining a relationship to a given organizational practice. Through accessing textual, social...

  1. Newcomer information seeking

    DEFF Research Database (Denmark)

    Moring, Camilla Elisabeth

    2017-01-01

    Introduction: Research on socialization and learning processes among organizational newcomers is offering valuable insight into the role of information seeking in the workplace, and to why, and how newcomers seek information when entering a new organization. Analysis: The aim of the paper...... is to outline and discuss the significance of information seeking in newcomer socialization and learning, and analyse how different approaches influence our understanding of the role of information seeking in the workplace. Results: It is argued, that a development in research on newcomer information seeking...... in organizations newcomers access to participate and negotiate meaning in practice becomes essential. Information seeking hereby plays a significant role in newcomers learning by establishing, developing, and maintaining a relationship to a given organizational practice. Through accessing textual, social...

  2. Bone tumor

    Science.gov (United States)

    Tumor - bone; Bone cancer; Primary bone tumor; Secondary bone tumor; Bone tumor - benign ... The cause of bone tumors is unknown. They often occur in areas of the bone that grow rapidly. Possible causes include: Genetic defects ...

  3. Applications of Beta Particle Detection for Synthesis and Usage of Radiotracers Developed for Positron Emission Tomography

    Science.gov (United States)

    Dooraghi, Alex Abreu

    Positron Emission Tomography (PET) is a noninvasive molecular imaging tool that requires the use of a radioactive compound or radiotracer which targets a molecular pathway of interest. We have developed and employed three beta particle radiation detection systems to advance PET. Specifically, the goals of these systems are to: 1. Automate dispensing of solutions containing a positron emitting isotope. 2. Monitor radioactivity on-chip during synthesis of a positron emitting radiotracer. 3. Assay cellular uptake on-chip of a positron emitting radiotracer. Automated protocols for measuring and dispensing solutions containing radioisotopes are essential not only for providing an optimum environment for radiation workers, but also to ensure a quantitatively accurate workflow. For the first project, we describe the development and performance of a system for automated radioactivity distribution of beta particle emitting radioisotopes such as fluorine-18 (F-18). Key to the system is a radiation detector in-line with a peristaltic pump. The system demonstrates volume accuracy within 5 % for volumes of 20 muL or greater. When considering volumes of 20 muL or greater, delivered radioactivity is in agreement with the requested radioactivity as measured with the dose calibrator. The integration of the detector and pump leads to a flexible system that can accurately dispense solutions containing F-18 in radioactivity concentrations directly produced from a cyclotron (~ 0.1-1 mCi/muL), to low activity concentrations intended for preclinical mouse scans (~ 1-10 muCi/muL), and anywhere in between. Electrowetting on dielectric (EWOD) is an attractive microfluidic platform for batch synthesis of PET radiotracers. Visualization of radioisotopes on-chip is critical for synthesis optimization and technological development. For the second project, we describe the development and performance of a Cerenkov/real-time imaging system for PET radiotracer synthesis on EWOD. We also investigate

  4. Long-Circulating and pH-Sensitive Liposome Preparation Trapping a Radiotracer for Inflammation Site Detection.

    Science.gov (United States)

    Mota, Luciene Das Graças; de Barros, André Luís Branco; Fuscaldi, Leonardo Lima; de Oliveira, Mônica Cristina; Cardoso, Valbert Nascimento

    2015-06-01

    Inflammatory and infectious diseases are one of the most common causes of mortality and morbidity. This paper aimed to prepare and to evaluate the ability of long-circulating and pH-sensitive liposomes, trapping a radiotracer, to identify inflamed focus. The physicochemical characterization of freeze-dried liposomes, using glucose as cryoprotectant, showed 80% of the vesicles with adequate mean diameter and good vesicle size homogeneity. Radiotracer encapsulation percentage in liposomes was 10.65%, of which 4.88% was adsorbed on the surface of the vesicles. Furthermore, liposomes presented positive zeta potential. Freeze-dried liposomes, stored for 180 days at 4 degrees C, did not show significant changes in the mean diameter, indicating good stability. Free radiotracer and radiolabeled liposomes were injected into inflammation focus-bearing rats, and ex-vivo biodistribution studies and scintigraphic images were performed. Results showed that radiopharmaceutical, free and encapsulated into liposomes, were able to identify the inflamed site. Target/non-target ratios, obtained by scintigraphic images, were greater than 1.5 at all investigated times. Data did not show significant differences between the free radiotracer and radiolabeled liposomes. Results suggest that this liposomal preparation could be employed as an alternative procedure for inflamed site detection by means of scintigraphic images. However, as the radiotracer is adsorbed onto the liposome surface by electrostatic forces, it is suggested that a neutral radiopharmaceutical be used to confirm the potential of this formulation as a scintigraphic probe for inflammation/infection detection.

  5. Radiotracer studies on ion-selective membranes based on poly(vinyl chloride) matrices.

    Science.gov (United States)

    Jaber, A M; Moody, G J; Thomas, J D; Willcox, A

    1977-10-01

    Radiotracer studies with (45)Ca, (89)Sr and (133)Ba have provided evidence that the permeation of magnesium, strontium and barium ions through PVC membranes containing Orion 92-20-02 liquid ion-exchanger is inhibited by their low affinity for the liquid ion-exchanger sites. Experiments with (7)Be indicate a strong affinity of the membrane for beryllium ions with corresponding inhibition of permeation. When acid is present in the solution on one side of the membrane, preferential permeation by protons may lead to transport of ions against their concentration gradient in order to maintain the balance of charge.

  6. Transmutation products may influence radiotracer diffusion rates in an ionic solid.

    Science.gov (United States)

    Wei, G C; Wuensch, B J

    1977-07-08

    An inherent aspect of radiotracer diffusion is that alpha, beta(+), or beta(-) emission produces a daughter element of different ionization state. This process must either cause a change in the vacancy concentrations or create space charge, depending on the effectiveness of the internal sources or sinks. Four coupled equations established to model the kinetics, when solved by numerical methods, predict that the apparent tracer diffusion rate may easily be in error by a factor of 2 or 3 and, under certain conditions, by as much as an order of magnitude.

  7. Ultrasonography of the testis: correlation with radiotracer perfusion. [/sup 99m/Tc-pertechnetate

    Energy Technology Data Exchange (ETDEWEB)

    Winston, M.A.; Handler, S.J.; Pritchard, J.H.

    1978-06-01

    Ultrasonic study of testicular disease and paratesticular masses was carried out in 20 cases. In eight of these comparison was made with pertechnetate perfusion studies performed concurrently. Testicular torsion was well revealed by both techniques. Acute orchitis, in the early stages, was shown more clearly by radiotracer, unless there was associated epididymal swelling or hydrocele. Chronic complications of inflammation, particularly abscess formation, were seen best by ultrasonography. Paratesticular masses could be studied only by ultrasound. These included both solid and cystic masses due to chronic epididymitis.

  8. Prediction of water vapor transport rates across polyvinylchloride packaging systems using a novel radiotracer method

    Energy Technology Data Exchange (ETDEWEB)

    Wood, R.W.; Mulski, M.J.; Kuu, W.Y. (Baxter Healthcare Corporation, Round Lake, IL (USA))

    1990-09-01

    A radiotracer method is used to study the transport properties of water vapor in polyvinylchloride (PVC), a plastic commonly used in the packaging of parenteral solutions. Water vapor transport across a PVC film appears to be Fickian in nature. Using the steady-state solution of Fick's second law and the permeability coefficient of water vapor across the PVC film obtained using the described method, the predicted water vapor transport rate (WVTR) for a parenteral solution packaged in PVC is in reasonable agreement with actual WVTR as determined by weight loss under precisely controlled conditions.

  9. The synthesis and evaluation of N{sup 1}-(4-(2-[{sup 18}F]-fluoroethyl)phenyl)-N{sup 8}-hydroxyoctanediamide ([{sup 18}F]-FESAHA), A PET radiotracer designed for the delineation of histone deacetylase expression in cancer

    Energy Technology Data Exchange (ETDEWEB)

    Zeglis, Brian M.; Pillarsetty, NagaVaraKishore; Divilov, Vadim [Radiochemistry Service, Department of Radiology, Memorial Sloan-Kettering Cancer Center, New York, NY 10021 (United States); Blasberg, Ronald A. [Department of Radiology, Memorial Sloan-Kettering Cancer Center, New York, NY 10021 (United States); Lewis, Jason S., E-mail: lewisj2@mskcc.org [Radiochemistry Service, Department of Radiology, Memorial Sloan-Kettering Cancer Center, New York, NY 10021 (United States); Program in Molecular Pharmacology and Chemistry, Sloan-Kettering Institute, Memorial Sloan-Kettering Cancer Center, New York, NY 10021 (United States)

    2011-07-15

    Introduction: Given the significant utility of suberoylanilide hydroxamic acid (SAHA) in chemotherapeutic protocols, a PET tracer that mimics the histone deacetylase (HDAC) inhibition of SAHA could be a valuable tool in the diagnosis, treatment planning and treatment monitoring of cancer. Here, we describe the synthesis, characterization and evaluation of N{sup 1}-(4-(2-[{sup 18}F]-fluoroethyl)phenyl)-N{sup 8}-hydroxyoctanediamide ([{sup 18}F]-FESAHA), a PET tracer designed for the delineation of HDAC expression in cancer. Methods: FESAHA was synthesized and biologically characterized in vivo and in vitro. [{sup 18}F]-FESAHA was then synthesized in high radiochemical purity, and the logP and serum stability of the radiotracer were determined. In vitro cellular uptake experiments and acute biodistribution and small-animal PET studies were performed with [{sup 18}F]-FESAHA in mice bearing LNCaP xenografts. Results: [{sup 18}F]-FESAHA was synthesized in high radiochemical purity via an innovative one-pot procedure. Enzymatic inhibition assays illustrated that FESAHA is a potent HDAC inhibitor, with IC{sub 50} values from 3 nM to 1.7 {mu}M against the 11 HDAC subtypes. Cell proliferation experiments revealed that the cytostatic properties of FESAHA very closely resemble those of SAHA in both LNCaP cells and PC-3 cells. Acute biodistribution and PET imaging experiments revealed tumor uptake of [{sup 18}F]-FESAHA and substantially higher values in the small intestine, kidneys, liver and bone. Conclusion: The significant non-tumor background uptake of [{sup 18}F]-FESAHA presents a substantial obstacle to the use of the radiotracer as an HDAC expression imaging agent. The study at hand, however, does present a number of lessons critical to both the synthesis of hydroxamic acid containing PET radiotracers and imaging agents aimed at delineating HDAC expression.

  10. seeking behavior in Nigeria

    African Journals Online (AJOL)

    2014-06-02

    Jun 2, 2014 ... Key Words: Immunization; growth chart; health-seeking behavior; child health; Nigeria. African Health ..... expensive but have short waiting time. They were ... urban resident) In the urban area, cost, time, perceived severity of ...

  11. Teaching information seeking

    Directory of Open Access Journals (Sweden)

    Louise Limberg

    2006-01-01

    Full Text Available Introduction. The article argues for a closer association between information seeking research and the practices of teaching information seeking. Findings are presented from a research project on information seeking, didactics and learning (IDOL investigating librarians' and teachers' experiences of teaching information seeking. Method. Thirteen teachers and five librarians, teaching 12-19 year-old students in three schools, participated. Forty-five interviews were conducted over a period of three years. Analysis. The IDOL project adopted a phenomenographic approach with the purpose of describing patterns of variation in experiences. The findings were also analysed by way of relating them to four competing approaches to the mediation of information literacy. Results. A gap was identified between experiences of teaching content that focused on sources and order, and experiences of assessment criteria applied to students' work that focused on the importance of correct facts and the analysis of information. These findings indicate a highly restricted range of teaching contents when compared with the four theoretical approaches to the mediation of information literacy. Conclusion. Teaching information seeking might be enhanced by a wider repertoire of contents reflecting more varied theoretical understanding developed in information seeking research, particularly as regards the importance of content and context related to user perspectives.

  12. Cross-Coupling Reactions as Valuable Tool for the Preparation of PET Radiotracers

    Directory of Open Access Journals (Sweden)

    Marc Pretze

    2011-01-01

    Full Text Available The increasing application of positron emission tomography (PET in nuclear medicine has stimulated the extensive development of a multitude of new radiotracers and novel radiolabeling procedures with the most prominent short-lived positron emitters carbon-11 and fluorine-18. Radiolabeling with these radionuclides represents a remarkable challenge. Special attention has to be paid to synthesis time and specific labeling techniques due to the short physical half life of the respective radionuclides 11C (t1/2 = 20.4 min and 18F (t1/2 = 109.8 min. In the past, numerous transition metal-catalyzed reactions were employed in organic chemistry, even though only a handful of these coupling reactions were adopted in radiochemical practice. Thus, the implementation of modern synthesis methods like cross-coupling reactions offers the possibility to develop a wide variety of novel radiotracers. The introduction of catalysts based on transition metal complexes bears a high potential for rapid, efficient, highly selective and functional group-tolerating incorporation of carbon-11 and fluorine-18 into target molecules. This review deals with design, application and improvement of transition metal-mediated carbon-carbon as well as carbon-heteroatom cross-coupling reactions as a labeling feature with the focus on the preparation of radiolabeled compounds for molecular imaging.

  13. Managing Lymphoma with Non-FDG Radiotracers: Current Clinical and Preclinical Applications

    Directory of Open Access Journals (Sweden)

    Fan-Lin Kong

    2013-01-01

    Full Text Available Nuclear medicine imaging modalities such as positron emission tomography (PET and single-photon emission computed tomography (SPECT have played a prominent role in lymphoma management. PET with [18F]Fluoro-2-deoxy-D-glucose (FDG is the most commonly used tool for lymphoma imaging. However, FDG-PET has several limitations that give the false positive or false negative diagnosis of lymphoma. Therefore, development of new radiotracers with higher sensitivity, specificity, and different uptake mechanism is in great demand in the management of lymphoma. This paper reviews non-FDG radiopharmaceuticals that have been applied for PET and SPECT imaging in patients with different types of lymphoma, with attention to diagnosis, staging, therapy response assessment, and surveillance for disease relapse. In addition, we introduce three radiolabeled anti-CD20 antibodies for radioimmunotherapy, which is another important arm for lymphoma treatment and management. Finally, the relatively promising radiotracers that are currently under preclinical development are also discussed in this paper.

  14. Non-invasive radiotracer imaging as a tool for drug development.

    Science.gov (United States)

    Gibson, R E; Burns, H D; Hamill, T G; Eng, W S; Francis, B E; Ryan, C

    2000-07-01

    Non-Invasive Radiotracer Imaging (NIRI) uses either short-lived positron-emitting isotopes, such as 11C and 18F, for Positron Emis ion Tomography (PET) or single photon emitting nuclides, e.g., 123I, which provide images using planar imaging or Single-Photon Emission Computed Tomography (SPECT). These high-resolution imaging modalities provide anatomical distribution and localization of radiolabeled drugs, which can be used to generate real time receptor occupancy and off-rate studies in humans. This can be accomplished by either isotopically labeling a potential new drug (usually with 11C), or indirectly by studying how the unlabelled drug inhibits specific radioligand binding in vivo. Competitive blockade studies can be accomplished using a radiolabeled analogue which binds to the site of interest, rather than a radiolabeled version of the potential drug. Imaging, particularly PET imaging, can be used to demonstrate the effect of a drug through a biochemical marker of processes such as glucose metabolism or blood flow. NIRI as a development tool in the pharmaceutical industry is gaining increased acceptance as its unique ability to provide such critical information in human subjects is recognized. This section will review recent examples that illustrate the utility of NIRI, principally PET, in drug development, and the potential of imaging advances in the development of cancer drugs and gene therapy. Finally, we provide a brief overview of the design of new radiotracers for novel targets.

  15. [(18)F]6-fluoro-3,4-dihydroxy-L-phenylalanine--recent modern syntheses for an elusive radiotracer.

    Science.gov (United States)

    Edwards, Richard; Wirth, Thomas

    2015-05-15

    [(18)F]6-fluoro-3,4-dihydroxy-L-phenylalanine ([(18)F]F-DOPA) has been known to be a useful radiotracer for over 30 years. Its widespread clinical use has been hampered by the lack of a robust, high yielding synthesis. This review summarises new developments in radiochemistry that are providing solutions to long standing problems involved in the synthesis of this important but elusive radiotracer. Considerable advances in nucleophilic synthesis have been achieved by optimising multistep strategies and using both hypervalent iodine chemistry and transition metal-mediated fluorinations allowing for the production of high specific activity [(18)F]F-DOPA.

  16. Information seeking behavior

    DEFF Research Database (Denmark)

    Hjørland, Birger

    2000-01-01

    the teleological or goal-oriented nature of the behaviour of living organisms. Such a theory should define the essential characteristics in human information seeking, including a description of it cultural and social determinants. It should consider the costs and benefits of information seeking, and the social......A general theory of information seeking behaviour must include an outline of an evolutionary theory of how organisms have adapted their cognitive apparatus to the demands raised in order to cope with their environments. It should describe important qualitative stages in this development and explain...... mechanisms influencing its value. Further, such a theory should explain information neglecting and avoidance, the utilisation of different kinds of information resources, the strategies used, and their efficiency. A general theory should formulate what the essential, non-trivial factors are, which can...

  17. Information seeking behavior

    DEFF Research Database (Denmark)

    Hjørland, Birger

    2000-01-01

    A general theory of information seeking behaviour must include an outline of an evolutionary theory of how organisms have adapted their cognitive apparatus to the demands raised in order to cope with their environments. It should describe important qualitative stages in this development and explain...... the teleological or goal-oriented nature of the behaviour of living organisms. Such a theory should define the essential characteristics in human information seeking, including a description of it cultural and social determinants. It should consider the costs and benefits of information seeking, and the social...... mechanisms influencing its value. Further, such a theory should explain information neglecting and avoidance, the utilisation of different kinds of information resources, the strategies used, and their efficiency. A general theory should formulate what the essential, non-trivial factors are, which can...

  18. In-vivo imaging characteristics of two fluorinated flumazenil radiotracers in the rat

    Energy Technology Data Exchange (ETDEWEB)

    Dedeurwaerdere, Stefanie [University of Melbourne, Department of Medicine (RMH), Parkville, VIC (Australia); ANSTO, Radiopharmaceuticals Research Institute, Sydney (Australia); Gregoire, Marie-Claude; Fookes, Christopher; Greguric, Ivan; Pham, Tien; Loc' h, Christian; Katsifis, Andrew [ANSTO, Radiopharmaceuticals Research Institute, Sydney (Australia); Vivash, Lucy; O' Brien, Terence J.; Myers, Damian E. [University of Melbourne, Department of Medicine (RMH), Parkville, VIC (Australia); Roselt, Peter; Binns, David; Hicks, Rodney J. [Peter MacCallum Cancer Centre, Centre for Molecular Imaging, Melbourne (Australia)

    2009-06-15

    [{sup 11}C]Flumazenil shows promise as a clinical and research PET radiotracer to image changes in GABA{sub A} central benzodiazepine receptor (cBZR), but its widespread use has been limited by practical limitations of [{sup 11}C]. This study evaluated the imaging characteristics of two fluorinated PET radiotracers in rats in vivo: [{sup 18}F]fluoroflumazenil ([{sup 18}F]FFMZ) and [{sup 18}F]flumazenil ([{sup 18}F]FMZ). PET acquisitions were performed on a small-animal scanner following injection of [{sup 18}F]FFMZ in nine rats and [{sup 18}F]FMZ in eight rats. The following treatments were investigated: (1) injection of the tracer dose, (2) presaturation then injection of the tracer dose, and (3) injection of the tracer dose followed by a displacement injection. Unchanged tracer was measured in plasma and brain structures in four animals 10 and 30 min after injection, and ex-vivo autoradiography was also performed. For both [{sup 18}F]FFMZ and [{sup 18}F]FMZ maximal brain activity peaked rapidly, and was highest in the hippocampus (1.12{+-}0.06 SUV, 1.24{+-}0.10 SUV, respectively), and lowest in the pons (1.00{+-}0.07 SUV, 1.03{+-}0.09 SUV, respectively). By 50 min after injection, maximal uptake for [{sup 18}F]FFMZ and [{sup 18}F]FMZ had decreased in the hippocampus to 18{+-}3% and 80{+-}1% (p<0.01), respectively. The presaturation and displacement studies showed a higher nonspecific component for [{sup 18}F]FFMZ than for [{sup 18}F]FMZ. Metabolite studies showed that at 30 min only 10% of the signal was from [{sup 18}F]FFMZ in the brain. This nonspecific binding was apparent on autoradiography. In contrast, [{sup 18}F]FMZ accounted for >70% of the signal in the brain, which resulted in well-defined regional binding on autoradiography. These results demonstrate that [{sup 18}F]FMZ is a superior radiotracer to [{sup 18}F]FFMZ for in-vivo PET imaging of the GABA{sub A}/cBZR, having slower metabolism and leading to lower concentrations of metabolites in the brain

  19. Pharmacokinetic evaluation of the tau PET radiotracer [18F]T807 ([18F]AV-1451) in human subjects.

    Science.gov (United States)

    Wooten, Dustin; Guehl, Nicolas J; Verwer, Eline E; Shoup, Timothy M; Yokell, Daniel L; Zubcevik, Nevena; Vasdev, Neil; Zafonte, Ross D; Johnson, Keith A; El Fakhri, Georges; Normandin, Marc David

    2016-09-22

    [(18)F]T807 is a PET radiotracer developed for imaging tau protein aggregates, which are implicated in neurological disorders including Alzheimer's disease (AD) and traumatic brain injury (TBI). The current study characterizes [(18)F]T807 pharmacokinetics in human subjects using dynamic PET imaging and metabolite-corrected arterial input functions.

  20. Challenges in the development of dopamine D2- and D3-selective radiotracers for PET imaging studies.

    Science.gov (United States)

    Mach, Robert H; Luedtke, Robert R

    2017-08-31

    The dopamine D2-like receptors (ie, D2/3 receptors) have been the most extensively studied CNS receptor with Positron Emission Tomography (PET). The 3 different radiotracers that have been used in these studies are [(11) C]raclopride, [(18) F]fallypride, and [(11) C]PHNO. Because these radiotracers have a high affinity for both dopamine D2 and D3 receptors, the density of dopamine receptors in the CNS is reported as the D2/3 binding potential, which reflects a measure of the density of both receptor subtypes. Although the development of D2- and D3-selective PET radiotracers has been an active area of research for many years, this by and large presents an unmet need in the area of translational PET imaging studies. This article discusses some of the challenges that have inhibited progress in this area of research and the current status of the development of subtype selective radiotracers for imaging D3 and D2 dopamine receptors with PET. Copyright © 2017 John Wiley & Sons, Ltd.

  1. Improving the stability of peptidic radiotracers by the introduction of artificial scaffolds: which structure element is most useful?

    Science.gov (United States)

    Bacher, Lisa; Fischer, Gabriel; Litau, Shanna; Schirrmacher, Ralf; Wängler, Björn; Baller, Marko; Wängler, Carmen

    2015-08-01

    Peptidic radiotracers are highly potent substances for the specific in vivo imaging of various biological targets with Single Photon Emission Computed Tomography and Positron Emission Tomography. However, some radiolabeled peptides such as bombesin analogs were shown to exhibit only a limited stability, hampering a successful target visualization. One option to positively influence the stability of radiolabeled peptides is the introduction of certain artificial molecular scaffolds. In order to comparatively assess the influence of different structure elements on the stability of radiolabeled peptides and to identify those structure elements being most useful for peptide radiotracer stabilization, several monomeric and dimeric bombesin derivatives were synthesized, exhibiting differing molecular designs and the chelator NODAGA for (68) Ga-labeling. The radiolabeled peptides were evaluated regarding their in vitro stability in human serum to determine the influence of the introduced molecular scaffolds on the peptides' serum stabilities. The results of the evaluations showed that the introduction of scaffold structures and the overall molecular design have a substantial impact on the stabilities of the resulting peptidic radiotracers. But besides some general trends found using certain scaffold structures, the obtained results point to the necessity to empirically assess their influence on stability for each susceptible peptidic radiotracer individually.

  2. Radiotracer studies on calcium ion-selective electrode membranes based on poly(vinyl chloride) matrices.

    Science.gov (United States)

    Craggs, A; Moody, G J; Thomas, J D; Willcox, A

    Radiotracer studies with (45)Ca and (36)Cl demonstrate that PVC matrix membranes containing Orion 92-20-02 liquid calcium ion-exchanger are permselective to counter-cations. Diffusion coefficients are quoted for the migration of (45)Ca between pairs of calcium solutions and are discussed in terms of solution concentration, membrane thickness and concentration level of sensor in the membrane. Migration of calcium ions from calcium chloride solution to a Group (II) metal chloride solution through a PVC membrane containing calcium liquid ion-exchanger is discussed in terms of solvent extraction and electrode selectivity coefficient parameters. Thus, magnesium, strontium and barium ions appear to inhibit migration through the membrane by their low affinity for the membrane liquid ion-exchanger sites, while the inhibition by beryllium ions is attributed to site blockage by the strong affinity of dialkylphosphate sites for beryllium.

  3. Applications of radiotracer techniques for the pharmacology and toxicology studies of nanomaterials

    Institute of Scientific and Technical Information of China (English)

    ZHANG ZhiYong; ZHAO YuLiang; CHAI ZhiFang

    2009-01-01

    With the rapid development of nanosciences and nanotechnology, a wide variety of manufactured nanomaterials are now used in commodities, pharmaceutics, cosmetics, biomedical products, and in-dustries. While nanomaterials possess more novel and unique physicochemical properties than bulk materials, they also have an unpredictable impact on human health. In the pharmacology and toxicol-ogy studies of nanomaterials, it is essential to know the basic behavior in vivo, i.e. absorption, distri-bution, metabolism, and excretion (ADME) of these newly designed materials. Radiotracer techniques are especially well suited to such studies and have got the chance to demonstrate their enchantment.In this paper, radiolabeling methods for carbon nanomaterials, metallic and metal oxide nanoparticles,etc. are summarized and the applications of the radiolabeled nanomaterials in pharmacology and toxicology studies are outlined.

  4. Experimental observation of silver and gold penetration into dental ceramic by means of a radiotracer technique

    Energy Technology Data Exchange (ETDEWEB)

    Moya, F.; Payan, J.; Bernardini, J.; Moya, E.G.

    1987-12-01

    A radiotracer technique was used to study silver and gold diffusion into dental porcelain under experimental conditions close to the real conditions in prosthetic laboratories for porcelain bakes. It was clearly shown that these non-oxidizable elements were able to diffuse into the ceramic as well as oxidizable ones. The penetration depth varied widely according to the element. The ratio DAg/DAu was about 10(3) around 850 degrees C. In contrast to gold, the silver diffusion rate was high enough to allow silver, from the metallic alloy, to be present at the external ceramic surface after diffusion into the ceramic. Hence, the greening of dental porcelains baked on silver-rich alloys could be explained mainly by a solid-state diffusion mechanism.

  5. A radiotracer for In vivo studies of acetylcholinesterase: p-[{sup 18}F]fluorodonepezil

    Energy Technology Data Exchange (ETDEWEB)

    Lee, S. Y.; Choi, Y. S.; Choi, Y.; Kim, S. E.; Lee, K. H.; Kim, B. T. [Samsung Medical Center, Seoul (Korea, Republic of); Lee, J. W. [Seoul National Univ., Seoul (Korea, Republic of)

    1999-05-01

    Alzheimer's disease (AD) is one of senile dementia caused by lack of acetylcholine in central nervous system, and in vivo studies of acetylcholinesterase (AChE) have been carried out using many radiolabeled AChE inhibitors (donepezil, tacrine, physostigmine, CP-126,998, etc). Donepezil, a FDA approved drug for AD is now in clinical use. Therefore, we synthesized and evaluated p-[{sup 18}F]fluorodonepezil in mice. Biodistribution studies demonstrated that p-[{sup 18}F]fluorodonepezil binds non-specifically in vivo and does not suffer from metabolism in mouse brain. This study suggests that radioligands with higher binding affinity may be required to visualize AChE in vivo and further studies are needed to develop better radiotracers.

  6. Radiotracer diffusion in semiconductors and metallic compounds using short-lived isotopes

    CERN Multimedia

    Deicher, M; Kronenberg, J; Wagner, F E

    The transport of atoms in solids is of central importance for solid state physics, chemistry, metallurgy, and material sciences. Since the mobility of atoms in solids contributes to many physical phenomena the study of diffusion processes is of fundamental interest for solid state physics. Diffusion processes were frequently investigated using radioactive isotopes (radiotracers). The application of short-lived isotopes delivered at ISOLDE extends substantially the possibilities of investigating diffusion processes in solids. In particular, a new experimental set-up to be installed at ISOLDE in this year will enable the use of radioactive isotopes with half-lives down to minutes. Alternatively, in special cases diffusion processes can be investigated with help of hyperfine techniques on an atomic scale, like by perturbed $\\gamma \\gamma$-angular correlation (PAC). Here, the motion of the atom of interest becomes visible directly via characteristic changes in the measured PAC spectra.

  7. Crystallographic study of PET radiotracers in clinical evaluation for early diagnosis of Alzheimers

    Directory of Open Access Journals (Sweden)

    Angela Altomare

    2014-11-01

    Full Text Available The title compound, C24H25NO3·2CH3OH, which crystallized as a methanol disolvate, has applications as a PET radiotracer in the early diagnosis of Alzheimer's disease. The dihedral angle between the biphenyl rings is 8.2 (2° and the heterocyclic ring adopts a half-chair conformation with the N atom adopting a pyramidal geometry (bond-angle sum = 327.6°. The C atoms of both methoxy groups lie close to the plane of their attached ring [deviations = 0.107 (6 and 0.031 (6 Å]. In the crystal, the components are linked by O—H...O and O—H...N hydrogen bonds, generating [010] chains. C—H...O interactions are also observed.

  8. Radiotracer evaluation of laterite and coal-ash dust discharged into the environment

    Energy Technology Data Exchange (ETDEWEB)

    Thereska, J.; Cuci, T.; Spahiu, P.; Plasari, E. [Institute of Nuclear Physics, Tirane (Albania). Tracer Section

    1993-12-31

    In Elbasan steel plant a large quantity of dust is discharged into the environment by laterite fluidized bed calciner and the coal boiler for steam production. By means of radiotracers the erosion of the laterite in the fluidized bed calciner was estimated experimentally. Based on the experimental data a mathematical model has been constructed for the erosion, which permits calculation of the mass of the dust deriving from erosion when the granulometric composition of the mineral on entry to the calciner is known. The efficiency of two types of cyclones in laterite calciner and coal boiler, for three granulometric classes of laterite dust and coal-ash was studied. Ways of reducing the quantity of dust discharged into environment are proposed.

  9. Auctions with rent seeking

    NARCIS (Netherlands)

    Haan, Marco; Schoonbeek, Lambert

    2000-01-01

    We present a model which combines elements of an auction and a rent-seeking contest. Players compete for a prize. Apart from exerting lobbying efforts, they also have to submit a bid which is payable only if they win the prize. First, we analyze the model if the returns-to-scale parameters of both b

  10. Multidrug resistance mediated by ABC transporters in osteosarcoma cell lines: mRNA analysis and functional radiotracer studies

    Energy Technology Data Exchange (ETDEWEB)

    Gomes, Celia Maria Freitas [Department of Pathology, Leiden University Medical Center, 2300 RC Leiden (Netherlands); Faculty of Medicine, Institute of Biophysics/Biomathematics, IBILI, 3000-354 Coimbra (Portugal)]. E-mail: cgomes@ibili.uc.pt; van Paassen, Heidi [Department of Pathology, Leiden University Medical Center, 2300 RC Leiden (Netherlands); Romeo, Salvatore [Department of Pathology, Leiden University Medical Center, 2300 RC Leiden (Netherlands); Welling, Mick M. [Department of Radiology, Section of Nuclear Medicine, Leiden University Medical Center, 2300 RC Leiden (Netherlands); Feitsma, R.I.J. [Department of Radiology, Section of Nuclear Medicine, Leiden University Medical Center, 2300 RC Leiden (Netherlands); Abrunhosa, Antero J. [Faculty of Medicine, Institute of Biophysics/Biomathematics, IBILI, 3000-354 Coimbra (Portugal); Botelho, M. Filomena [Faculty of Medicine, Institute of Biophysics/Biomathematics, IBILI, 3000-354 Coimbra (Portugal); Hogendoorn, Pancras C.W. [Department of Pathology, Leiden University Medical Center, 2300 RC Leiden (Netherlands); Pauwels, Ernest [Department of Radiology, Section of Nuclear Medicine, Leiden University Medical Center, 2300 RC Leiden (Netherlands); Cleton-Jansen, Anne Marie [Department of Pathology, Leiden University Medical Center, 2300 RC Leiden (Netherlands)

    2006-10-15

    Drug resistance remains a significant impediment to successful chemotherapy and constitutes a major prognostic factor in osteosarcoma (OS) patients. This study was designed to identify the role and prognostic significance of multidrug-resistance (MDR)-related transporters, such as multidrug resistance protein 1 (MDR1), multidrug-resistance-associated protein (MRP1) and breast-cancer-related protein (BCRP), in OS using cationic lipophilic radiotracers. We evaluated the chemosensitivity of four OS cell lines (Saos-2, 143B, MNNG/HOS and U-2OS) to doxorubicin (DOX), cisplatin (CIS) and methotrexate. The expression of MDR-related transporters was analyzed at mRNA level by quantitative polymerase chain reaction and at functional level by {sup 99m}Tc sestamibi and {sup 99m}Tc tetrofosmin. The effectiveness of MDR modulators [cyclosporin A (CsA) and imatinib] on transporter inhibition and on the reversal of resistance was also assessed. MNNG/HOS and U-2OS cells expressing high levels of MDR1 were highly resistant to DOX and showed reduced accumulation and higher efflux for radiotracers. Although MRP1 was uniformly expressed in all cells, only U-2OS was resistant to CIS. CsA restored sensitivity to DOX and CIS, and enhanced the accumulation and efflux half-life of radiotracers in MDR1-expressing cell lines. The chemosensitivity of OS cells to DOX was strongly dependent on mRNA MDR1 expression and could be circumvented by adding CsA. The kinetic parameters of radiotracers correlated with MDR1 expression levels, hence predicting DOX resistance. We concluded that sensitivity to chemotherapy is strongly dependent on the expression of MDR1 transporter and that radiotracer studies could prove clinically useful in predicting chemotherapy response and in evaluating the efficacy of MDR-reversing agents.

  11. Predicting future morphological changes of lesions from radiotracer uptake in 18F-FDG-PET images.

    Directory of Open Access Journals (Sweden)

    Ulas Bagci

    Full Text Available We introduce a novel computational framework to enable automated identification of texture and shape features of lesions on (18F-FDG-PET images through a graph-based image segmentation method. The proposed framework predicts future morphological changes of lesions with high accuracy. The presented methodology has several benefits over conventional qualitative and semi-quantitative methods, due to its fully quantitative nature and high accuracy in each step of (i detection, (ii segmentation, and (iii feature extraction. To evaluate our proposed computational framework, thirty patients received 2 (18F-FDG-PET scans (60 scans total, at two different time points. Metastatic papillary renal cell carcinoma, cerebellar hemongioblastoma, non-small cell lung cancer, neurofibroma, lymphomatoid granulomatosis, lung neoplasm, neuroendocrine tumor, soft tissue thoracic mass, nonnecrotizing granulomatous inflammation, renal cell carcinoma with papillary and cystic features, diffuse large B-cell lymphoma, metastatic alveolar soft part sarcoma, and small cell lung cancer were included in this analysis. The radiotracer accumulation in patients' scans was automatically detected and segmented by the proposed segmentation algorithm. Delineated regions were used to extract shape and textural features, with the proposed adaptive feature extraction framework, as well as standardized uptake values (SUV of uptake regions, to conduct a broad quantitative analysis. Evaluation of segmentation results indicates that our proposed segmentation algorithm has a mean dice similarity coefficient of 85.75 ± 1.75%. We found that 28 of 68 extracted imaging features were correlated well with SUV(max (p<0.05, and some of the textural features (such as entropy and maximum probability were superior in predicting morphological changes of radiotracer uptake regions longitudinally, compared to single intensity feature such as SUV(max. We also found that integrating textural features with

  12. Imaging Atherosclerotic Plaque Inflammation via Folate Receptor Targeting Using a Novel 18F-Folate Radiotracer

    Directory of Open Access Journals (Sweden)

    Adrienne Müller

    2014-03-01

    Full Text Available Folate receptor β (FR-β is overexpressed on activated, but not resting, macrophages involved in a variety of inflammatory and autoimmune diseases. A pivotal step in atherogenesis is the subendothelial accumulation of macrophages. In nascent lesions, they coordinate the scavenging of lipids and cellular debris to define the likelihood of plaque inflammation and eventually rupture. In this study, we determined the presence of FR-β-expressing macrophages in atherosclerotic lesions by the use of a fluorine-18-labeled folate-based radiotracer. Human endarterectomized specimens were used to measure gene expression levels of FR-β and CD68. Increased FR-β and CD68 levels were found in atherosclerotic plaques compared to normal artery walls by quantitative real-time polymerase chain reaction. Western blotting and immunohistochemistry demonstrated prominent FR-β protein levels in plaques. FR- β-positive cells colocalized with activated macrophages (CD68 in plaque tissue. Carotid sections incubated with 3′-aza-2′- [18F]fluorofolic acid displayed increased accumulation in atherosclerotic plaques through in vitro autoradiography. Specific binding of the radiotracer correlated with FR-β-expressing macrophages. These results demonstrate high FR-β expression in atherosclerotic lesions of human carotid tissue correlating with CD68-positive macrophages. Areas of high 3′-aza-2′-[18F]fluorofolic acid binding within the lesions represented FR-β-expressing macrophages. Selectively targeting FR-β-positive macrophages through folate-based radiopharmaceuticals may be useful for noninvasive imaging of plaque inflammation.

  13. Amyloid PET imaging in Alzheimer's disease: a comparison of three radiotracers

    Energy Technology Data Exchange (ETDEWEB)

    Landau, S.M.; Jagust, W.J. [University of California, Berkeley, Helen Wills Neuroscience Institute, Berkeley, CA (United States); Lawrence Berkeley National Laboratory, Life Sciences Division, Berkeley, CA (United States); Thomas, B.A. [University College London, Institute of Nuclear Medicine, London (United Kingdom); Thurfjell, L. [GE Healthcare, Uppsala (Sweden); Schmidt, M. [Janssen Pharmaceutica, NV, Beerse (Belgium); Margolin, R. [Janssen Alzheimer Immunotherapy, South San Francisco, CA (United States); Mintun, M.; Pontecorvo, M. [Avid Radiopharmaceuticals, Inc., Philadelphia, PA (United States); Baker, S.L. [Lawrence Berkeley National Laboratory, Life Sciences Division, Berkeley, CA (United States); Collaboration: The Alzheimer' s Disease Neuroimaging Initiative

    2014-07-15

    The increasing use of amyloid PET in Alzheimer's disease research and clinical trials has motivated efforts to standardize methodology. We compared retention of the {sup 11}C radiotracer Pittsburgh Compound B (PiB) and that of two {sup 18}F amyloid radiotracers (florbetapir and flutemetamol) using two study populations. We also examined the feasibility of converting between tracer-specific measures, using PiB as the common link between the two {sup 18}F tracers. One group of 40 subjects underwent PiB and flutemetamol imaging sessions and a separate group of 32 subjects underwent PiB and florbetapir imaging sessions. We compared cortical and white matter retention for each {sup 18}F tracer relative to that of PiB, as well as retention in several reference regions and image analysis methods. Correlations between tracer pairs were used to convert tracer-specific threshold values for amyloid positivity between tracers. Cortical retention for each pair of tracers was strongly correlated regardless of reference region (PiB-flutemetamol, ρ = 0.84-0.99; PiB-florbetapir, ρ = 0.83-0.97) and analysis method (ρ = 0.90-0.99). Compared to PiB, flutemetamol had higher white matter retention, while florbetapir had lower cortical retention. Two previously established independent thresholds for amyloid positivity were highly consistent when values were converted between tracer pairs. Despite differing white and grey matter retention characteristics, cortical retention for each {sup 18}F tracer was highly correlated with that of PiB, enabling conversion of thresholds across tracer measurement scales with a high level of internal consistency. Standardization of analysis methods and measurement scales may facilitate the comparison of amyloid PET data obtained using different tracers. (orig.)

  14. Bone Biopsy

    Science.gov (United States)

    ... News Physician Resources Professions Site Index A-Z Bone Biopsy Bone biopsy uses a needle and imaging ... the limitations of Bone Biopsy? What is a Bone Biopsy? A bone biopsy is an image-guided ...

  15. Bone Densitometry (Bone Density Scan)

    Science.gov (United States)

    ... News Physician Resources Professions Site Index A-Z Bone Densitometry (DEXA) Bone densitometry, also called dual-energy ... limitations of DEXA Bone Densitometry? What is a Bone Density Scan (DEXA)? Bone density scanning, also called ...

  16. Development of Bone Remodeling Model for Spaceflight Bone Physiology Analysis

    Science.gov (United States)

    Pennline, James A.; Werner, Christopher R.; Lewandowski, Beth; Thompson, Bill; Sibonga, Jean; Mulugeta, Lealem

    2015-01-01

    Current spaceflight exercise countermeasures do not eliminate bone loss. Astronauts lose bone mass at a rate of 1-2% a month (Lang et al. 2004, Buckey 2006, LeBlanc et al. 2007). This may lead to early onset osteoporosis and place the astronauts at greater risk of fracture later in their lives. NASA seeks to improve understanding of the mechanisms of bone remodeling and demineralization in 1g in order to appropriately quantify long term risks to astronauts and improve countermeasures. NASA's Digital Astronaut Project (DAP) is working with NASA's bone discipline to develop a validated computational model to augment research efforts aimed at achieving this goal.

  17. Development of gamma emitting receptor binding radiotracers for imaging the brain and pancreas. Final technical progress report, March 1, 1988--May 31, 1993

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1996-01-01

    This document give paragraph synopses of results in research on brain and pancreas imaging, using radiotracers. General catagories of research included chemistry, pharmacology, imaging physics, and kinetic modeling. A list of publications is included

  18. Radiotracer method for residence time distribution study in multiphase flow system

    Energy Technology Data Exchange (ETDEWEB)

    Sugiharto, S. [Department of Physics, Faculty of Mathematics and Natural Sciences, Bandung Institute of Technology, Jl. Ganesha 10, Bandung 40132 (Indonesia); Center for the Application of Isotopes and Radiation Technology - National Nuclear Energy Agency, Jl Lebak Bulus No. 49, Jakarta 12440 (Indonesia)], E-mail: sugi@batan.go.id; Su' ud, Z. [Department of Physics, Faculty of Mathematics and Natural Sciences, Bandung Institute of Technology, Jl. Ganesha 10, Bandung 40132 (Indonesia)], E-mail: szaki@fi.itb.ac.id; Kurniadi, R. [Department of Physics, Faculty of Mathematics and Natural Sciences, Bandung Institute of Technology, Jl. Ganesha 10, Bandung 40132 (Indonesia); Wibisono, W.; Abidin, Z. [Center for the Application of Isotopes and Radiation Technology - National Nuclear Energy Agency, Jl Lebak Bulus No. 49, Jakarta 12440 (Indonesia)

    2009-07-15

    [{sup 131}I] isotope in different chemical compounds have been injected into 24 in hydrocarbon transmission pipeline containing approximately 95% water, 3% crude oil, 2% gas and negligible solid material, respectively. The system is operated at the temperature around 70 deg. C enabling fluids flow is easier in the pipeline. The segment of measurement was chosen far from the junction point of the pipeline, therefore, it was reasonably to assume that the fluids in such multiphase system were separated distinctively. Expandable tubing of injector was used to ensure that the isotopes were injected at the proper place in the sense that [{sup 131}I]Na isotope was injected into water layer and iodo-benzene, {sup [131]}IC{sub 6}H{sub 5,} was injected into crude oil regime. The radiotracer selection was based on the compatibility of radiotracer with each of fluids under investigation. [{sup 131}I]Na was used for measuring flow of water while iodo-benzene, {sup [131]}IC{sub 6}H{sub 5,} was used for measuring flow of crude oil. Two scintillation detectors were used and they are put at the distances 80 and 100 m, respectively, from injection point. The residence time distribution data were utilized for calculation water and crude oil flows. Several injections were conducted in the experiments. Although the crude oil density is lighter than the density of water, the result of measurement shows that the water flow is faster than the crude oil flow. As the system is water-dominated, water may act as carrier and the movement of crude oil is slowed due to friction between crude oil with water and crude oil with gas at top layer. Above of all, this result was able to give answer on the question why crude oil always arrives behind water as it is checked at gathering station. In addition, the flow patterns of the water in the pipeline calculated by Reynolds number and predicted by simple tank-in-series model is turbulence in character.

  19. Semi-automated lab-on-a-chip for dispensing GA-68 radiotracers

    Energy Technology Data Exchange (ETDEWEB)

    Weinberg, Irving [Weinberg Medical Physics LLC, Bethesda, MD (United States)

    2014-03-12

    We solved a technical problem that is hindering American progress in molecular medicine, and restricting US citizens from receiving optimal diagnostic care. Specifically, the project deals with a mother/daughter generator of positron-emitting radiotracers (Ge-68/Ga-68). These generator systems are approved in Europe but cannot be used in the USA, because of safety issues related to possible breakthrough of long-lived Ge-68 (mother) atoms. Europeans have demonstrated abilities of Ga-68-labeled radiotracers to image cancer foci with high sensitivity and specificity, and to use such methods to effectively plan therapy.The USA Food and Drug Administration (FDA) and Nuclear Regulatory Commission (NRC) have taken the position that every patient administration of Ga-68 should be preceded by an assay demonstrated that Ge-68 breakthrough is within acceptable limits. Breakthrough of parent elements is a sensitive subject at the FDA, as evidenced by the recent recall of Rb-82 generators due to inadvertent administrations of Sr-82. Commercially, there is no acceptable rapid method for assaying breakthrough of Ge-68 prior to each human administration. The gamma emissions of daughter Ga-68 have higher energies than the parent Ge-68, so that the shielding assays typically employed for Mo-99/Tc-99m generators cannot be applied to Ga-68 generators. The half-life of Ga-68 is 68 minutes, so that the standard 10-half-life delay (used to assess breakthrough in Sr-82/Rb-82 generators) cannot be applied to Ga-68 generators. As a result of the aforementioned regulatory requirements, Ga-68 generators are sold in the USA for animal use only.The American clinical community’s inability to utilize Ga-68 generators impairs abilities to treat patients domestically, and puts the USA at a disadvantage in developing exportable products. The proposed DOE project aimed to take advantage of recent technological advances developed for lab-on-a-chip (LOC) applications. Based on our experiences

  20. Simpler and More Accurate: Weighing the Mercury in Electrolytic Cells by Radiotracer Dilution Method

    Directory of Open Access Journals (Sweden)

    Sugiharto

    2010-08-01

    Full Text Available Weight of mercury in electrolytic cell of soda industry is usually measured gravimetrically, which is typical labor work in character. Error sources of the gravimetric method might have come from the fact that some mercury’s are usually trapped in the cell due to complicated structure of electrolytic cell. This cause unknown errors. In addition, formation of amalgam at the cathode may cause a further uncertainty in the measurement. Total error from gravimetric method is 4% on average. Radiotracer dilution method provides advantages either for simplification of procedure and reduction of measurement error. In this experiment radioisotope mercury 203Hg, which was prepared in nuclear reactor was used to examine 13 of 14 electrolytic cells of soda plant. Each electrolytic cell was designed containing approximately 700 kg inactive mercury. Before injection, the radioisotope mercury was mixed with non radioisotope mercury in a bath to obtain a suitable injection aliquots and standard references. Calibration curve, which was derived from two stage dilution processes taken from standard references, was used to examine degree of mixing between radioisotope and non radioisotope mercury and it was also used in weight calculation of non radioisotope mercury in electrolytic cell. Injection was carried out simply by pouring the injection aliquots into the flowing mercury at the inlet side of the cell. Mercury samples from the cells were extracted at regular time intervals and filled into vials for counting. This was done for the primary conformation of the completeness of mixing of the tracer with the non radioisotope mercury in each cell. When complete mixing is achieved, the unknown quantity of mercury in each cell was calculated based on mass balance principle. From the calculation the weight of mercury in each electrolytic cell was not the same and maximum error of measurement obtained from this method is 2.48 %. Compared to gravimetrically error

  1. Seeking Global Minima

    Science.gov (United States)

    Tajuddin, Wan Ahmad

    1994-02-01

    Ease in finding the configuration at the global energy minimum in a symmetric neural network is important for combinatorial optimization problems. We carry out a comprehensive survey of available strategies for seeking global minima by comparing their performances in the binary representation problem. We recall our previous comparison of steepest descent with analog dynamics, genetic hill-climbing, simulated diffusion, simulated annealing, threshold accepting and simulated tunneling. To this, we add comparisons to other strategies including taboo search and one with field-ordered updating.

  2. Chemistry and biology of radiotracers that target changes in sympathetic and parasympathetic nervous systems in heart disease.

    Science.gov (United States)

    Eckelman, William C; Dilsizian, Vasken

    2015-06-01

    Following the discovery of the sympathetic and parasympathetic nervous system, numerous adrenoceptor drugs were radiolabeled and potent radioligands were prepared in order to image the β-adrenergic and the muscarinic systems. But the greatest effort has been in preparing noradrenaline analogs, such as norepinephrine, (11)C-metahydroxyephedrine, and (123)I-metaiodobenzylguanidine that measure cardiac sympathetic nerve varicosities. Given the technical and clinical challenges in designing and validating targeted adrenoceptor-binding radiotracers, namely the heavily weighted flow dependence and relatively low target-to-background ratio, both requiring complicated mathematic analysis, and the inability of targeted adrenoceptor radioligands to have an impact on clinical care of heart disease, the emphasis has been on radioligands monitoring the norepinephrine pathway. The chemistry and biology of such radiotracers, and the clinical and prognostic impact of these innervation imaging studies in patients with heart disease, are examined. © 2015 by the Society of Nuclear Medicine and Molecular Imaging, Inc.

  3. Establishment of a trimodality analytical platform for tracing, imaging and quantification of gold nanoparticles in animals by radiotracer techniques.

    Science.gov (United States)

    Chen, Chien-Hung; Lin, Fong-Sian; Liao, Wei-Neng; Liang, Sanching L; Chen, Min-Hua; Chen, Yo-Wen; Lin, Wan-Yu; Hsu, Ming-Hua; Wang, Mei-Ya; Peir, Jinn-Jer; Chou, Fong-In; Chen, Ching-Ya; Chen, Sih-Yu; Huang, Su-Chin; Yang, Mo-Hsiung; Hueng, Dueng-Yuan; Hwu, Yeukuang; Yang, Chung-Shi; Chen, Jen-Kun

    2015-01-06

    This study aims to establish a (198)Au-radiotracer technique for in vivo tracing, rapid quantification, and ex vivo visualization of PEGylated gold nanoparticles (GNPs) in animals, organs and tissue dissections. The advantages of GNPs lie in its superior optical property, biocompatibility and versatile conjugation chemistry, which are promising to develop diagnostic probes and drug delivery systems. (198)Au is used as a radiotracer because it simultaneously emits beta and gamma radiations with proper energy and half-life; therefore, (198)Au can be used for bioanalytical purposes. The (198)Au-tagged radioactive gold nanoparticles ((198)Au-GNPs) were prepared simply by irradiating the GNPs in a nuclear reactor through the (197)Au(n,γ)(198)Au reaction and subsequently the (198)Au-GNPs were subjected to surface modification with polyethylene glycol to form PEGylated (198)Au-GNPs. The (198)Au-GNPs retained physicochemical properties that were the same as those of GNP before neutron irradiation. Pharmacokinetic and biodisposition studies were performed by intravenously injecting three types of (198)Au-GNPs with or without PEGylation into mice; the γ radiation in blood specimens and dissected organs was then measured. The (198)Au-radiotracer technique enables rapid quantification freed from tedious sample preparation and shows more than 95% recovery of injected GNPs. Clinical gamma scintigraphy was proved feasible to explore spatial- and temporal-resolved biodisposition of (198)Au-GNPs in living animals. Moreover, autoradiography, which recorded beta particles from (198)Au, enabled visualizing the heterogeneous biodisposition of (198)Au-GNPs in different microenvironments and tissues. In this study, the (198)Au-radiotracer technique facilitated creating a trimodality analytical platform for tracing, quantifying and imaging GNPs in animals.

  4. Investigating phosphorus uptake in anoxic and sulfidic surface sediments with 33P radiotracer experiments

    Science.gov (United States)

    Dijkstra, Nikki; Kraal, Peter; Gonzalez, Santiago; Slomp, Caroline

    2016-04-01

    Phosphorus (P) is a key nutrient for marine organisms. Enhanced P availability in the water column can fuel algal blooms and the development of bottom water anoxia. Recently, it was suggested that micro-organisms in sediments overlain by anoxic and sulfidic bottom waters might take up dissolved P and form Fe(II)-P minerals, thereby enhancing P removal. In this study, we investigated the uptake of P in surface sediments with 33P radiotracer experiments. The sediments were recovered from the anoxic and sulfidic deep basin of the Black Sea and, for comparison, from the adjacent oxic shelf. Results suggest a very fast sedimentary uptake of 33P at all sites but in particular for sediments from the oxic shelf. At all sites, most 33P was sequestered in the citrate-dithionite-bicarbonate-(CDB)-extractable sediment P fraction. No significant differences with abiotic controls were observed, implying that micro-organisms were not directly involved in the P uptake. Whereas 33P uptake by the oxic shelf sediment was likely controlled by sorption of 33P to iron(Fe)-(oxyhydr)oxides, the nature of the CDB-extractable P fraction in the deep basin sediments remains unclear. We discuss whether authigenic formation of Fe(II)-P minerals or fast adsorption of P to calcites may explain our findings.

  5. Detailed spatio-temporal solids concentration profiling during batch settling of activated sludge using a radiotracer.

    Science.gov (United States)

    De Clercq, Jeriffa; Jacobs, Filip; Kinnear, David J; Nopens, Ingmar; Dierckx, Rudi A; Defrancq, Jacques; Vanrolleghem, Peter A

    2005-05-01

    In building and tuning good settling models for secondary clarifiers of wastewater treatment plants, there is a need for measured continuous solids concentration profiles during batch settling. Conventional measuring techniques have difficulties in recording this kind of data, either because they are invasive, or because of the low solids concentration and/or solids density of activated sludge. This paper investigates a novel non-invasive measurement technique borrowed from nuclear medicine, using a solids radiotracer and gamma cameras, to obtain solids concentration profiles during the batch settling of activated sludge, in a pilot-scale column with a height of 1m. The technique does not disturb the settling process, does not alter the settling characteristics, gives profiles every minute and every few millimeters, and is capable of measuring in a range of 0-25 g/l with high accuracy. Dynamic solids concentration profile measurements were performed for sludges of different wastewater treatment plants, and at different initial concentrations. The results show a quantitative representation of the settling process, and reveal hindered and compression settling.

  6. Radiotracer Methods for Targeted Imaging of the Epidermal Growth Factor Receptor

    Energy Technology Data Exchange (ETDEWEB)

    Jung, Kyung Ho; Lee, Kyung Han [Samsung Medical Center, Sungkyunkwan University School of Medicine, Seoul (Korea, Republic of)

    2008-06-15

    While indirect targeting strategies using reporter-genes are taking center stage in current molecular imaging research, another vital strategy has long involved direct imaging of specific receptors using radiolabeled ligands. Recently, there is renewal of immense interest in this area with particular attention to the epidermal growth factor receptor (EGFR), a transmembrane glycoprotein critically involved in the regulation of many cellular functions and malignancies. Recently, two novel classes of EGFR-targeting anticancer drugs have entered clinical trials with great expectations. These are monoclonal antibodies such as cetuximab that target the extracellular domain, and small molecule tyrosine kinase inhibitors such as gefitinib (Iressa) and erlotinib (Tarceva) that target the catalytic domain of the receptor. However, early results have showed disappointing survival benefits, disclosing a major challenge for this therapeutic strategy; namely, the need to identify tumors that are most likely to respond to the agents. To address this important clinical issue, several noninvasive imaging techniques are under investigation including radiolabeled probes based on small molecule tyrosine kinase inhibitors, anti-EGFR antibodies, and EGF peptides. This review describes the current status, limitations, and future prospects in the development of radiotracer methods for EGFR imaging.

  7. Bone within a bone

    Energy Technology Data Exchange (ETDEWEB)

    Williams, H.J.; Davies, A.M. E-mail: wendy.turner@roh.nhs.uk; Chapman, S

    2004-02-01

    The 'bone within a bone' appearance is a well-recognized radiological term with a variety of causes. It is important to recognize this appearance and also to be aware of the differential diagnosis. A number of common conditions infrequently cause this appearance. Other causes are rare and some remain primarily of historical interest, as they are no longer encountered in clinical practice. In this review we illustrate some of the conditions that can give the bone within a bone appearance and discuss the physiological and pathological aetiology of each where known.

  8. Sensation Seeking in Street Violence

    DEFF Research Database (Denmark)

    Heinskou, Marie Bruvik; Liebst, Lasse Suonperä

    Sensation seeking leads to violence—runs an influential hypothesis in the social scientific study of violent behavior. Although studies confirm that violence is sometimes structured by sensation-seeking motives, the literature seldom comments on the limits to this explanation of violence....... The present study examines the scale of violence motivated by sensation seeking and the degree to which there are several distinct forms of sensation seeking motives operative in violence, rather than a sensation-seeking motive in the singular. The study draws on a sample of situations from Copenhagen...... involving street violence, which are coded quantitatively and qualitatively. Our analysis shows that sensation seeking only seldom seems to play a role in the structuring of street violence. Moreover, the data indicate that sensation seeking finds expression in street violence situations in two different...

  9. Calciphylaxis on bone scan: correlation between molecular and cross-sectional findings

    Directory of Open Access Journals (Sweden)

    Malak Itani, MD

    2017-03-01

    Full Text Available Calciphylaxis is a rare devastating medical condition commonly associated with end-stage renal disease and characterized by extensive microvascular calcifications. We describe a case of calciphylaxis presenting on Tc-99m MDP bone scan imaging with asymmetric radiotracer uptake within the lower extremities corresponding to extensive soft tissue calcifications on Computed tomography. Familiarity with the classic clinical presentation and imaging features of this rare entity may help its early identification and treatment.

  10. Sexual minorities seeking services.

    Science.gov (United States)

    Rogers, Tracey L; Emanuel, Kristen; Bradford, Judith

    2003-01-01

    SUMMARY Understanding the mental health needs of lesbian and bisexual (sexual minority) women is an integral part of designing and providing appropriate mental health services and treatment for them. In an effort to understand the mental health needs of sexual minority women who seek community treatment, a chart review was conducted of the 223 lesbian and bisexual women who presented for services between July 1, 1997 and December 31, 2000 at Fenway Community Health in Boston, MA. Data are based on clients' self-reports and clinician assessments of clients' presenting problem, relevant developmental history, prior mental health and substance abuse treatment, current reports of emotional/psychological symptoms, and areas of impaired functioning. Although substance abuse and suicidal ideation were commonly reported problems, other concerns were more frequently reported. High percentages of lesbians and bisexual women reported relationship concerns and lack of adequate social networks; rates of depression and anxiety based on clinicians' assessments were also high. Overall, lesbians and bisexual women did not differ in the issues they brought to treatment or level or types of impairment. Compared with previous community survey samples, however, study participants appeared to be healthier than general, non-clinical samples of self-identified lesbians, possibly reflecting the special characteristics of sexual minority women who seek treatment in specialized community sites such as the Fenway. Although patients who come to these sites may not represent the more general population of sexual minority women, community health centers known to serve lesbian, gay, bisexual and transgender (LGBT) individuals may be fruitful access points for studying the mental health status and treatment needs of sexual minority women.

  11. Comparison of In Vitro Assays in Selecting Radiotracers for In Vivo P-Glycoprotein PET Imaging

    Directory of Open Access Journals (Sweden)

    Renske M. Raaphorst

    2017-09-01

    Full Text Available Positron emission tomography (PET imaging of P-glycoprotein (P-gp in the blood-brain barrier can be important in neurological diseases where P-gp is affected, such as Alzheimer´s disease. Radiotracers used in the imaging studies are present at very small, nanomolar, concentration, whereas in vitro assays where these tracers are characterized, are usually performed at micromolar concentration, causing often discrepant in vivo and in vitro data. We had in vivo rodent PET data of [11C]verapamil, (R-N-[18F]fluoroethylverapamil, (R-O-[18F]fluoroethyl-norverapamil, [18F]MC225 and [18F]MC224 and we included also two new molecules [18F]MC198 and [18F]KE64 in this study. To improve the predictive value of in vitro assays, we labeled all the tracers with tritium and performed bidirectional substrate transport assay in MDCKII-MDR1 cells at three different concentrations (0.01, 1 and 50 µM and also inhibition assay with P-gp inhibitors. As a comparison, we used non-radioactive molecules in transport assay in Caco-2 cells at a concentration of 10 µM and in calcein-AM inhibition assay in MDCKII-MDR1 cells. All the P-gp substrates were transported dose-dependently. At the highest concentration (50 µM, P-gp was saturated in a similar way as after treatment with P-gp inhibitors. Best in vivo correlation was obtained with the bidirectional transport assay at a concentration of 0.01 µM. One micromolar concentration in a transport assay or calcein-AM assay alone is not sufficient for correct in vivo prediction of substrate P-gp PET ligands.

  12. Care seeking for orofacial pain

    NARCIS (Netherlands)

    Rollman, A.; Visscher, C.M.; Gorter, R.C.; Naeije, M.

    2012-01-01

    AIMS: To determine the contribution of a wide range of factors to care-seeking behavior in orofacial pain patients, expressed as (A) decision to seek care and (B) number of health care practitioners visited. METHODS: Subjects with orofacial pain complaints were recruited in seven TMD clinics and fro

  13. Care seeking for orofacial pain

    NARCIS (Netherlands)

    Rollman, A.; Visscher, C.M.; Gorter, R.C.; Naeije, M.

    2012-01-01

    AIMS: To determine the contribution of a wide range of factors to care-seeking behavior in orofacial pain patients, expressed as (A) decision to seek care and (B) number of health care practitioners visited. METHODS: Subjects with orofacial pain complaints were recruited in seven TMD clinics and

  14. Clinical Translation of a Dual Integrin αvβ3- and Gastrin-Releasing Peptide Receptor-Targeting PET Radiotracer, 68Ga-BBN-RGD.

    Science.gov (United States)

    Zhang, Jingjing; Niu, Gang; Lang, Lixin; Li, Fang; Fan, Xinrong; Yan, Xuefeng; Yao, Shaobo; Yan, Weigang; Huo, Li; Chen, Libo; Li, Zhiyuan; Zhu, Zhaohui; Chen, Xiaoyuan

    2017-02-01

    This study aimed to document the first-in-human application of a (68)Ga-labeled heterodimeric peptide BBN-RGD (bombesin-RGD) that targets both integrin αvβ3 and gastrin-releasing peptide receptor (GRPR). We evaluated the safety and assessed the clinical diagnostic value of (68)Ga-BBN-RGD PET/CT in prostate cancer patients in comparison with (68)Ga-BBN. Five healthy volunteers (4 men and 1 woman; age range, 28-53 y) were enrolled to validate the safety of (68)Ga-BBN-RGD. Dosimetry was calculated using the OLINDA/EXM software. Thirteen patients with prostate cancer (4 newly diagnosed and 9 posttherapy) were enrolled. All the patients underwent PET/CT scans 15-30 min after intravenous injection of 1.85 MBq (0.05 mCi) per kilogram of body weight of (68)Ga-BBN-RGD and also accepted (68)Ga-BBN PET/CT within 2 wk for comparison. With a mean injected dose of 107.3 ± 14.8 MBq per patient, no side effect was found during the whole procedure and 2 wk follow-up, demonstrating the safety of (68)Ga-BBN-RGD. A patient would be exposed to a radiation dose of 2.90 mSv with an injected dose of 129.5 MBq (3.5 mCi), which is much lower than the dose limit set by the Food and Drug Administration. In 13 patients with prostate cancer diagnosed by biopsy, (68)Ga-BBN-RGD PET/CT detected 3 of 4 primary tumors, 14 metastatic lymph nodes, and 20 bone lesions with an SUVmax of 4.46 ± 0.50, 6.26 ± 2.95, and 4.84 ± 1.57, respectively. Only 2 of 4 primary tumors, 5 lymph nodes, and 12 bone lesions were positive on (68)Ga-BBN PET/CT, with the SUVmax of 2.98 ± 1.24, 4.17 ± 1.89, and 3.61 ± 1.85, respectively. This study indicates the safety and efficiency of a new type of dual integrin αvβ3- and GRPR-targeting PET radiotracer in prostate cancer diagnosis and staging. © 2017 by the Society of Nuclear Medicine and Molecular Imaging.

  15. Bone scan

    Science.gov (United States)

    ... legs, or spine fractures) Diagnose a bone infection (osteomyelitis) Diagnose or determine the cause of bone pain, ... 2015:chap 43. Read More Broken bone Metabolism Osteomyelitis Review Date 12/10/2015 Updated by: Jatin ...

  16. Bone Cancer

    Science.gov (United States)

    Cancer that starts in a bone is uncommon. Cancer that has spread to the bone from another ... more common. There are three types of bone cancer: Osteosarcoma - occurs most often between ages 10 and ...

  17. Bone Diseases

    Science.gov (United States)

    Your bones help you move, give you shape and support your body. They are living tissues that rebuild constantly ... childhood and your teens, your body adds new bone faster than it removes old bone. After about ...

  18. Bone Markers

    Science.gov (United States)

    ... markers may be seen in conditions such as: Osteoporosis Paget disease Cancer that has spread to the bone (metastatic bone disease) Hyperparathyroidism Hyperthyroidism Osteomalacia in adults and rickets in children—lack of bone mineralization, ...

  19. Breakdowns in collaborative information seeking

    DEFF Research Database (Denmark)

    Hertzum, Morten

    2010-01-01

    of the use of the electronic medication record adopted in a Danish healthcare region and of the reports of five years of medication incidents at Danish hospitals. The results show that breakdowns in collaborative information seeking is a major source of medication incidents, that most of these breakdowns......Collaborative information seeking is integral to many professional activities. In hospital work, the medication process encompasses continual seeking for information and collaborative grounding of information. This study investigates breakdowns in collaborative information seeking through analyses...... are breakdowns in collaborative grounding rather than information seeking, that the medication incidents mainly concern breakdowns in the use of records as opposed to oral communication, that the breakdowns span multiple degrees of separation between clinicians, and that the electronic medication record has...

  20. [{sup 11}C]CURB: Evaluation of a novel radiotracer for imaging fatty acid amide hydrolase by positron emission tomography

    Energy Technology Data Exchange (ETDEWEB)

    Wilson, Alan A., E-mail: alan.wilson@camhpet.c [PET Centre, Centre for Addiction and Mental Health, Toronto, Ontario, M5T 1R8 (Canada); Human Neurochemical Pathology Laboratory, Centre for Addiction and Mental Health, Toronto, Ontario, M5T 1R8 (Canada); Garcia, Armando; Parkes, Jun [PET Centre, Centre for Addiction and Mental Health, Toronto, Ontario, M5T 1R8 (Canada); Houle, Sylvain [PET Centre, Centre for Addiction and Mental Health, Toronto, Ontario, M5T 1R8 (Canada); Human Neurochemical Pathology Laboratory, Centre for Addiction and Mental Health, Toronto, Ontario, M5T 1R8 (Canada); Tong, Junchao [Department of Psychiatry, University of Toronto, Toronto, Ontario, M5T 1R8 (Canada); Vasdev, Neil [PET Centre, Centre for Addiction and Mental Health, Toronto, Ontario, M5T 1R8 (Canada); Human Neurochemical Pathology Laboratory, Centre for Addiction and Mental Health, Toronto, Ontario, M5T 1R8 (Canada)

    2011-02-15

    Introduction: Fatty acid amide hydrolase (FAAH) is the enzyme responsible for metabolising the endogenous cannabinoid, anandamide, and thus represents an important target for molecular imaging. To date, no radiotracer has been shown to be useful for imaging of FAAH using either positron emission tomography (PET) or single photon emission computed tomography (SPECT). We here determine the suitability of a novel carbon-11-labeled inhibitor of FAAH via ex vivo biodistribution studies in rat brain in conjunction with pharmacological challenges. Methods: A potent irreversible inhibitor of FAAH, URB694, radiolabeled with carbon-11 in the carbonyl position ([{sup 11}C]CURB), was administered to male rats via tail-vein injection. Rats were sacrificed at various time points postinjection, and tissue samples were dissected, counted and weighed. Specific binding to FAAH was investigated by pretreatment of animals with URB694 or URB597. For metabolism and mechanism of binding studies, whole brains were excised post-radiotracer injection, homogenised and extracted exhaustively with 80% aq. acetonitrile to determine the time course and fraction of radioactivity that was irreversibly bound to brain parenchyma. Results: Upon intravenous injection into rats, [{sup 11}C]CURB showed high brain uptake [standard uptake value (SUV) of 1.6-2.4 at 5 min] with little washout over time, which is characteristic of irreversible binding. Highest uptake of radioactivity was seen in the cortex, intermediate in the cerebellum and lowest in the hypothalamus, reflecting the reported distribution of FAAH. Brain uptake of radioactivity was decreased in a dose-dependent manner by pretreatment with increasing amounts of URB694, demonstrating that binding was saturable. Pretreatment with the well-characterised FAAH inhibitor, URB597, reduced binding in all brain regions by 70-80%. Homogenised brain extraction experiments demonstrated unequivocally that [{sup 11}C]CURB was irreversibly bound to FAAH

  1. Pancreatic Ductal Adenocarcinoma With High Radiotracer Uptake in 68Ga-Prostate-Specific Membrane Antigen PET/CT.

    Science.gov (United States)

    Sahbai, Samine; Rieping, Petra; Pfannenberg, Christina; la Fougére, Christian; Reimold, Matthias

    2017-09-01

    Prostate-specific membrane antigen imaging with PET/CT is increasingly used in prostate cancer and was shown to have a high diagnostic performance. We report a clinical case of a 67-year-old man with previous history of operated prostate cancer and increasing prostate-specific antigen blood level. Ga-HBED-CC prostate-specific membrane antigen PET/CT imaging was indicated for the assessment of local recurrence and lymph node metastases of prostate cancer. In addition, a soft tissue mass in the body of the pancreas with high radiotracer uptake was detected. Histopathology confirmed a pancreatic ductal adenocarcinoma.

  2. Radiopharmacological evaluation of 6-deoxy-6-[{sup 18}F]fluoro-D-fructose as a radiotracer for PET imaging of GLUT5 in breast cancer

    Energy Technology Data Exchange (ETDEWEB)

    Wuest, Melinda, E-mail: mwuest@ualberta.c [Department of Oncology, University of Alberta - Cross Cancer Institute, Edmonton, AB-T6G 1Z2 (Canada); Trayner, Brendan J. [Department of Physiology, University of Alberta, Edmonton, AB-T6G 1Z2 (Canada); Grant, Tina N. [Department of Physiology, University of Alberta, Edmonton, AB-T6G 1Z2 (Canada); Department of Chemistry, University of Alberta, Edmonton, AB-T6G 1Z2 (Canada); Jans, Hans-Soenke; Mercer, John R.; Murray, David [Department of Oncology, University of Alberta - Cross Cancer Institute, Edmonton, AB-T6G 1Z2 (Canada); West, Frederick G. [Department of Chemistry, University of Alberta, Edmonton, AB-T6G 1Z2 (Canada); McEwan, Alexander J.B.; Wuest, Frank [Department of Oncology, University of Alberta - Cross Cancer Institute, Edmonton, AB-T6G 1Z2 (Canada); Cheeseman, Chris I. [Department of Physiology, University of Alberta, Edmonton, AB-T6G 1Z2 (Canada)

    2011-05-15

    Introduction: Several clinical studies have shown low or no expression of GLUT1 in breast cancer patients, which may account for the low clinical specificity and sensitivity of 2-deoxy-2-[{sup 18}F]fluoro-D-glucose ([{sup 18}F]FDG) used in positron emission tomography (PET). Therefore, it has been proposed that other tumor characteristics such as the high expression of GLUT2 and GLUT5 in many breast tumors could be used to develop alternative strategies to detect breast cancer. Here we have studied the in vitro and in vivo radiopharmacological profile of 6-deoxy-6-[{sup 18}F]fluoro-D-fructose (6-[{sup 18}F]FDF) as a potential PET radiotracer to image GLUT5 expression in breast cancers. Methods: Uptake of 6-[{sup 18}F]FDF was studied in murine EMT-6 and human MCF-7 breast cancer cells over 60 min and compared to [{sup 18}F]FDG. Biodistribution of 6-[{sup 18}F]FDF was determined in BALB/c mice. Tumor uptake was studied with dynamic small animal PET in EMT-6 tumor-bearing BALB/c mice and human xenograft MCF-7 tumor-bearing NIH-III mice in comparison to [{sup 18}F]FDG. 6-[{sup 18}F]FDF metabolism was investigated in mouse blood and urine. Results: 6-[{sup 18}F]FDF is taken up by EMT-6 and MCF-7 breast tumor cells independent of extracellular glucose levels but dependent on the extracellular concentration of fructose. After 60 min, 30{+-}4% (n=9) and 12{+-}1% (n=7) ID/mg protein 6-[{sup 18}F]FDF was found in EMT-6 and MCF-7 cells, respectively. 6-deoxy-6-fluoro-D-fructose had a 10-fold higher potency than fructose to inhibit 6-[{sup 18}F]FDF uptake into EMT-6 cells. Biodistribution in normal mice revealed radioactivity uptake in bone and brain. Radioactivity was accumulated in EMT-6 tumors reaching 3.65{+-}0.30% ID/g (n=3) at 5 min post injection and decreasing to 1.75{+-}0.03% ID/g (n=3) at 120 min post injection. Dynamic small animal PET showed significantly lower radioactivity uptake after 15 min post injection in MCF-7 tumors [standard uptake value (SUV)=0

  3. Synthesis and Biological Evaluation of Thiophene-Based Cannabinoid Receptor Type 2 Radiotracers for PET Imaging

    Directory of Open Access Journals (Sweden)

    Ahmed Haider

    2016-07-01

    -vein injection. Evaluation of the CB2-positive spleen, however, showed no accumulation of the radiotracer. Despite the promising in vitro binding affinities, specific binding of [11C]AAT-015 and [11C]AAT-778 could not be demonstrated.

  4. Mercury methylation and reduction potentials in marine water: An improved methodology using {sup 197}Hg radiotracer

    Energy Technology Data Exchange (ETDEWEB)

    Koron, Neza [National Institute of Biology, Marine Biology Station, Fornace 41, 6330 Piran (Slovenia); Bratkic, Arne [Department of Environmental Sciences, ' Jozef Stefan' Institute, Jamova 39, 1000 Ljubljana (Slovenia); Ribeiro Guevara, Sergio, E-mail: ribeiro@cab.cnea.gov.ar [Laboratorio de Analisis por Activacion Neutronica, Centro Atomico Bariloche, Av. Bustillo km 9.5, 8400 Bariloche (Argentina); Vahcic, Mitja; Horvat, Milena [Department of Environmental Sciences, ' Jozef Stefan' Institute, Jamova 39, 1000 Ljubljana (Slovenia)

    2012-01-15

    A highly sensitive laboratory methodology for simultaneous determination of methylation and reduction of spiked inorganic mercury (Hg{sup 2+}) in marine water labelled with high specific activity radiotracer ({sup 197}Hg prepared from enriched {sup 196}Hg stable isotope) was developed. A conventional extraction protocol for methylmercury (CH{sub 3}Hg{sup +}) was modified in order to significantly reduce the partitioning of interfering labelled Hg{sup 2+} into the final extract, thus allowing the detection of as little as 0.1% of the Hg{sup 2+} spike transformed to labelled CH{sub 3}Hg{sup +}. The efficiency of the modified CH{sub 3}Hg{sup +} extraction procedure was assessed by radiolabelled CH{sub 3}Hg{sup +} spikes corresponding to concentrations of methylmercury between 0.05 and 4 ng L{sup -1}. The recoveries were 73.0{+-}6.0% and 77.5{+-}3.9% for marine and MilliQ water, respectively. The reduction potential was assessed by purging and trapping the radiolabelled elemental Hg in a permanganate solution. The method allows detection of the reduction of as little as 0.001% of labelled Hg{sup 2+} spiked to natural waters. To our knowledge, the optimised methodology is among the most sensitive available to study the Hg methylation and reduction potential, therefore allowing experiments to be done at spikes close to natural levels (1-10 ng L{sup -1}). - Highlights: Black-Right-Pointing-Pointer Inorganic mercury methylation and reduction in marine water were studied. Black-Right-Pointing-Pointer High specific activity {sup 197}Hg was used to label Hg{sup 2+} spikes at natural levels. Black-Right-Pointing-Pointer Methylmercury extraction had 73% efficiency for 0.05-4 ng L{sup -1} levels. Black-Right-Pointing-Pointer High sensibility to assess methylation potentials, below 0.1% of the spike. Black-Right-Pointing-Pointer High sensibility also for reduction potentials, as low as 0.001% of the spike.

  5. Synthesis and Biological Evaluation of Thiophene-Based Cannabinoid Receptor Type 2 Radiotracers for PET Imaging

    Science.gov (United States)

    Haider, Ahmed; Müller Herde, Adrienne; Slavik, Roger; Weber, Markus; Mugnaini, Claudia; Ligresti, Alessia; Schibli, Roger; Mu, Linjing; Mensah Ametamey, Simon

    2016-01-01

    . Evaluation of the CB2-positive spleen, however, showed no accumulation of the radiotracer. Despite the promising in vitro binding affinities, specific binding of [11C]AAT-015, and [11C]AAT-778 could not be demonstrated. PMID:27512365

  6. Unusual appearance for urinary bladder obstruction detected with 99mTc-MDP bone scintigraphy.

    Science.gov (United States)

    Wright, Chadwick L; Sharma, Akash

    2015-12-01

    Unanticipated but clinically significant nonosseous findings can be detected during routine bone scintigraphy. We present a case of an 83-year-old man who presented with a pathologic fracture of the right femur. Whole-body bone scintigraphy for osseous staging revealed intense radiotracer accumulation in the kidneys and ureters but no activity within the urinary bladder. The patient had not voided for 14 hours. A Foley catheter was inserted, and more than 2000 mL of urine was drained, most consistent with urinary bladder obstruction. Subsequent repeat images demonstrated marked reduction of the renal and ureteral activity with trace activity in the urinary bladder.

  7. Measurements of liquid phase residence time distributions in a pilot-scale continuous leaching reactor using radiotracer technique.

    Science.gov (United States)

    Pant, H J; Sharma, V K; Shenoy, K T; Sreenivas, T

    2015-03-01

    An alkaline based continuous leaching process is commonly used for extraction of uranium from uranium ore. The reactor in which the leaching process is carried out is called a continuous leaching reactor (CLR) and is expected to behave as a continuously stirred tank reactor (CSTR) for the liquid phase. A pilot-scale CLR used in a Technology Demonstration Pilot Plant (TDPP) was designed, installed and operated; and thus needed to be tested for its hydrodynamic behavior. A radiotracer investigation was carried out in the CLR for measurement of residence time distribution (RTD) of liquid phase with specific objectives to characterize the flow behavior of the reactor and validate its design. Bromine-82 as ammonium bromide was used as a radiotracer and about 40-60MBq activity was used in each run. The measured RTD curves were treated and mean residence times were determined and simulated using a tanks-in-series model. The result of simulation indicated no flow abnormality and the reactor behaved as an ideal CSTR for the range of the operating conditions used in the investigation.

  8. Development of Tyrosine-Based Radiotracer Tc99m-N4-Tyrosine for Breast Cancer Imaging

    Directory of Open Access Journals (Sweden)

    Fan-Lin Kong

    2012-01-01

    Full Text Available The purpose of this study was to develop an efficient way to synthesize Tc99m-O-[3-(1,4,8,11-tetraazabicyclohexadecane-propyl]-tyrosine (Tc99m-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 Tc99m with high radiochemical purity (>95%. Cellular uptake of Tc99m-N4-Tyrosine was much higher than that of Tc99m-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 Tc99m-N4-Tyrosine could be safely administered to humans. Evaluation in breast tumor-bearing rats showed that although Tc99m-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. Tc99m-N4-Tyrosine could thus be a useful radiotracer for use in breast tumor diagnostic imaging.

  9. Synthesis, radioiodination and in vivo screening of novel potent iodinated and fluorinated radiotracers as melanoma imaging and therapeutic probes.

    Science.gov (United States)

    Maisonial, Aurélie; Billaud, Emilie M F; Besse, Sophie; Rbah-Vidal, Latifa; Papon, Janine; Audin, Laurent; Bayle, Martine; Galmier, Marie-Josèphe; Tarrit, Sébastien; Borel, Michèle; Askienazy, Serge; Madelmont, Jean-Claude; Moins, Nicole; Auzeloux, Philippe; Miot-Noirault, Elisabeth; Chezal, Jean-Michel

    2013-05-01

    In order to develop new iodinated and fluorinated matched-pair radiotracers for Single-Photon Emission Computed Tomography (SPECT)/Positron Emission Tomography (PET) imaging and targeted radionuclide therapy of melanoma, we successfully synthesized and radiolabelled with iodine-125 seven new derivatives, starting from our previously described lead structure 3. The relevance of these radiotracers for gamma scintigraphic imaging of melanoma in rodent was assessed. The tumoural radioactivity uptake was most often high and specific even at early time points (12.1-18.3% ID/g at 3 h p.i. for [(125)I]39-42) and a fast clearance from the non-target organs was observed. Also, calculated effective doses that could be delivered to tumours when using corresponding [(131)I]-labelled analogues were generally higher than 100 cGy/MBq injected (98.9-150.5 cGy/MBq for [(131)I]39-42). These results make compounds 39-42 suitable candidates for (i) PET imaging of melanoma after labelling with fluorine-18 and (ii) targeted radionuclide therapy of disseminated melanoma after labelling with iodine-131.

  10. Somatization and health seeking behavior

    National Research Council Canada - National Science Library

    Vishal Garala; Mehul Brahmbhatt; Hemang Shah; Ganpat Vankar

    2014-01-01

    Background: Somatization is the state of being symptomatic which is not explained medically associated with psychological distress and health-seeking behavior and is present in at least 10% to 15% in OPD. Methods...

  11. {sup 18}F-GE-180: a novel TSPO radiotracer compared to {sup 11}C-R-PK11195 in a preclinical model of stroke

    Energy Technology Data Exchange (ETDEWEB)

    Boutin, Herve; Gerhard, Alexander [University of Manchester, Faculty of Medical and Human Sciences, Manchester (United Kingdom); University of Manchester, Wolfson Molecular Imaging Centre, Manchester (United Kingdom); Murray, Katie [University of Manchester, Faculty of Life Sciences, Manchester (United Kingdom); Pradillo, Jesus [University of Manchester, Faculty of Life Sciences, Manchester (United Kingdom); Universidad Complutense/Politecnica de Madrid, Madrid (Spain); Maroy, Renaud [SHFJ - CEA Orsay, Orsay (France); Smigova, Alison [University of Manchester, Wolfson Molecular Imaging Centre, Manchester (United Kingdom); Jones, Paul A.; Trigg, William [GE Healthcare Ltd., Amersham (United Kingdom)

    2014-10-29

    Neuroinflammation plays a critical role in various neuropathological conditions, and hence there is renewed interest in the translocator protein (TSPO) as a biomarker of microglial activation and macrophage infiltration in the brain. This is reflected in the large amount of research conducted seeking to replace the prototypical PET radiotracer {sup 11}C-R-PK11195 with a TSPO ligand with higher performance. Here we report the in vivo preclinical investigation of the novel TSPO tracer {sup 18}F-GE-180 in a rat model of stroke. Focal cerebral ischaemia was induced in Wistar rats by 60-min occlusion of the middle cerebral artery (MCAO). Brain damage was assessed 24 h after MCAO by T2 MRI. Rats were scanned with {sup 11}C-R-PK11195 and {sup 18}F-GE-180 5 or 6 days after MCAO. Specificity of binding was confirmed by injection of unlabelled R-PK11195 or GE-180 20 min after injection of {sup 18}F-GE-180. In vivo data were confirmed by ex vivo immunohistochemistry for microglial (CD11b) and astrocytic biomarkers (GFAP). {sup 18}F-GE-180 uptake was 24 % higher in the core of the ischaemic lesion and 18 % lower in the contralateral healthy tissue than that of {sup 11}C-R-PK11195 uptake (1.5 ± 0.2-fold higher signal to noise ratio). We confirmed this finding using the simplified reference tissue model (BP{sub ND} = 3.5 ± 0.4 and 2.4 ± 0.5 for {sup 18}F-GE-180 and {sup 11}C-R-PK11195, respectively, with R{sub 1} = 1). Injection of unlabelled R-PK11195 or GE-180 20 min after injection of {sup 18}F-GE-180 significantly displaced {sup 18}F-GE-180 (69 ± 5 % and 63 ± 4 %, respectively). Specificity of the binding was also confirmed by in vitro autoradiography, and the location and presence of activated microglia and infiltrated macrophages were confirmed by immunohistochemistry. The in vivo binding characteristics of {sup 18}F-GE-180 demonstrate a better signal to noise ratio than {sup 11}C-R-PK11195 due to both a better signal in the lesion and lower nonspecific binding in

  12. Bone Densitometry (Bone Density Scan)

    Science.gov (United States)

    ... of DXA Bone Densitometry? What is a Bone Density Scan (DXA)? Bone density scanning, also called dual-energy x-ray absorptiometry ( ... is today's established standard for measuring bone mineral density (BMD). An x-ray (radiograph) is a noninvasive ...

  13. Bone marrow aspiration

    Science.gov (United States)

    Iliac crest tap; Sternal tap; Leukemia - bone marrow aspiration; Aplastic anemia - bone marrow aspiration; Myelodysplastic syndrome - bone marrow aspiration; Thrombocytopenia - bone marrow aspiration; Myelofibrosis - bone marrow aspiration

  14. Development of new folate-based PET radiotracers: preclinical evaluation of {sup 68}Ga-DOTA-folate conjugates

    Energy Technology Data Exchange (ETDEWEB)

    Fani, Melpomeni; Maecke, Helmut R. [University Hospital Basel, Division of Radiological Chemistry, Basel (Switzerland); University Hospital Freiburg, Clinic for Nuclear Medicine, Freiburg (Germany); Wang, Xuejuan [University Hospital Basel, Division of Radiological Chemistry, Basel (Switzerland); Nicolas, Guillaume [University Hospital Basel, Department of Nuclear Medicine, Basel (Switzerland); Medina, Christelle; Raynal, Isabelle; Port, Marc [Guerbet, Research Department, Aulnay-sous-Bois (France)

    2011-01-15

    A number of {sup 111}In- and {sup 99m}Tc-folate-based tracers have been evaluated as diagnostic agents for imaging folate receptor (FR)-positive tumours. A {sup 68}Ga-folate-based radiopharmaceutical would be of great interest, combining the advantages of PET technology and the availability of {sup 68}Ga from a generator. The aim of the study was to develop a new {sup 68}Ga-folate-based PET radiotracer. Two new DOTA-folate conjugates, named P3026 and P1254, were synthesized using the 1,2-diaminoethane and 3-{l_brace}2-[2-(3-amino-propoxy)-ethoxy]-ethoxy{r_brace}-propylamine as a spacer, respectively. Both conjugates were labelled with {sup 67/68}Ga. Binding affinity, internalization and externalization studies were performed using the FR-positive KB cell line. Biodistribution and PET/CT imaging studies were performed in nude mice, on a folate-deficient diet, bearing KB and HT1080 (FR-negative) tumours, concurrently. The new radiotracers were evaluated comparatively to the reference molecule {sup 111}In-DTPA-folate ({sup 111}In-P3139). The K{sub d} values of {sup 67/68}Ga-P3026 (4.65 {+-} 0.82 nM) and {sup 67/68}Ga-P1254 (4.27 {+-} 0.42 nM) showed high affinity for the FR. The internalization rate followed the order {sup 67/68}Ga-P3026 >{sup 67/68}Ga-P1254 >{sup 111}In-P3139, while almost double cellular retention was found for {sup 67/68}Ga-P3026 and {sup 67/68}Ga-P1254, compared to {sup 111}In-P3139. The biodistribution data of {sup 67/68}Ga-DOTA-folates showed high and receptor-mediated uptake on the FR-positive tumours and kidneys, with no significant differences compared to {sup 111}In-P3139. PET/CT images, performed with {sup 68}Ga-P3026, showed high uptake in the kidneys and clear visualization of the FR-positive tumours. The DOTA-folate conjugates can be efficiently labelled with {sup 68}Ga in labelling yields and specific activities which allow clinical application. The characteristics of the {sup 67/68}Ga-DOTA-folates are comparable to {sup 111}In

  15. PET imaging of HSV1-tk mutants with acquired specificity toward pyrimidine- and acycloguanosine-based radiotracers

    Energy Technology Data Exchange (ETDEWEB)

    Likar, Yury; Dobrenkov, Konstantin; Olszewska, Malgorzata; Shenker, Larissa; Hricak, Hedvig; Ponomarev, Vladimir [Memorial Sloan-Kettering Cancer Center, Molecular Imaging Laboratory, Department of Radiology, New York, NY (United States); Cai, Shangde [Memorial Sloan-Kettering Cancer Center, Radiochemistry/Cyclotron Core Facility, New York, NY (United States)

    2009-08-15

    The aim of this study was to create an alternative mutant of the herpes simplex virus type 1 thymidine kinase (HSV1-tk) reporter gene with reduced phosphorylation capacity for acycloguanosine derivatives, but not pyrimidine-based compounds that will allow for successful PET imaging. A new mutant of HSV1-tk reporter gene, suitable for PET imaging using pyrimidine-based radiotracers, was developed. The HSV1-tk mutant contains an arginine-to-glutamine substitution at position 176 (HSV1-R176Qtk) of the nucleoside binding region of the enzyme. The mutant-gene product showed favorable enzymatic characteristics toward pyrimidine-based nucleosides, while exhibiting reduced activity with acycloguanosine derivatives. In order to enhance HSV1-R176Qtk reporter activity with pyrimidine-based radiotracers, we introduced the R176Q substitution into the more active HSV1-sr39tk mutant. U87 human glioma cells transduced with the HSV1-R176Qsr39tk double mutant reporter gene showed high {sup 3}H-FEAU pyrimidine nucleoside and low {sup 3}H-penciclovir acycloguanosine analog uptake in vitro. PET imaging also demonstrated high {sup 18}F-FEAU and low {sup 18}F-FHBG accumulation in HSV1-R176Qsr39tk+ xenografts. The feasibility of imaging two independent nucleoside-specific HSV1-tk mutants in the same animal with PET was demonstrated. Two opposite xenografts expressing the HSV1-R176Qsr39tk reporter gene and the previously described acycloguanosine-specific mutant of HSV1-tk, HSV1-A167Ysr39tk reporter gene, were imaged using a short-lived pyrimidine-based {sup 18}F-FEAU and an acycloguanosine-based {sup 18}F-FHBG radiotracer, respectively, administered on 2 consecutive days. We conclude that in combination with acycloguanosine-specific HSV1-A167Ysr39tk reporter gene, a HSV1-tk mutant containing the R176Q substitution could be used for PET imaging of two different cell populations or concurrent molecular biological processes in the same living subject. (orig.)

  16. DOE Final Technical Report (2009-2016): "Research Projects for Interrogations of Biological Systems: Training for the Development of Novel Radiotracers"

    Energy Technology Data Exchange (ETDEWEB)

    Jurisson, Silvia [University of Missouri-Columbia; Lever, Susan [University of Missouri-Columbia; Robertson, J. David [University of Missouri-Columbia

    2016-10-04

    This is the final technical report for DOE grant DE-SC-0002040, which was entitled "Research Projects for Interrogations of Biological Systems: Training for the Development of Novel Radiotracers". Included are the students and postdoctoral fellows trained, the publications, dissertations, presentations, and other deliverables for this project.

  17. Radiosynthesis and radiopharmacological evaluation of [N-methyl-{sup 11}C]Org 34850 as a glucocorticoid receptor (GR)-binding radiotracer

    Energy Technology Data Exchange (ETDEWEB)

    Wuest, Frank [Institut fuer Radiopharmazie, Forschungszentrum Dresden-Rossendorf e.V., POB 51 01 19, D-01314 Dresden (Germany); Department of Oncologic Imaging, Cross Cancer Institute, University of Alberta, Edmonton, Alberta, Canada T6G 1Z2 (Canada)], E-mail: frankwue@cancerboard.ab.ca; Kniess, Torsten [Institut fuer Radiopharmazie, Forschungszentrum Dresden-Rossendorf e.V., POB 51 01 19, D-01314 Dresden (Germany); Henry, Brian; Peeters, Bernardus W.M.M.; Wiegerinck, Peter H.G. [Schering-Plough, PO Box 20, 5340 BH Oss (Netherlands); Pietzsch, Jens; Bergmann, Ralf [Institut fuer Radiopharmazie, Forschungszentrum Dresden-Rossendorf e.V., POB 51 01 19, D-01314 Dresden (Germany)

    2009-02-15

    The radiosynthesis of [N-methyl-{sup 11}C]Org 34850 as a potential brain glucocorticoid receptor (GR)-binding radiotracer is described. The radiosynthesis was accomplished via N-methylation of the corresponding desmethyl precursor with [{sup 11}C]methyl triflate in a remotely controlled synthesis module to give the desired compound in a radiochemical yield of 23{+-}5% (decay-corrected, based upon [{sup 11}C]CO{sub 2}) at a specific activity of 47{+-}12 GBq/{mu}mol (n=15) at the end-of-synthesis (EOS). The radiochemical purity after semi-preparative HPLC purification exceeded 95%. The total synthesis time was 35-40 min after end-of-bombardment (EOB). The radiotracer is rapidly metabolized in rat plasma leading to the formation of two more hydrophilic metabolites as the major metabolites. Radiopharmacological evaluation involving biodistribution and small animal PET imaging in normal Wistar rats showed that the compound [N-methyl-{sup 11}C]Org 34850 is not able to sufficiently penetrate the blood-brain barrier. Therefore, compound [N-methyl-{sup 11}C]Org 34850 seems not to be a suitable PET radiotracer for imaging rat brain GRs. However, involvement of Pgp or species differences requires further clarification to establish whether the radiotracer [N-methyl-{sup 11}C]Org 34850 may still represent a suitable candidate for imaging GRs in humans.

  18. International students’ information seeking behavior

    DEFF Research Database (Denmark)

    Hyldegård, Jette Seiden

    2016-01-01

    This report presents the first results and reflections from an exploratory case study carried out at The Royal School of Library and Information Science in 2015 on international students’ information seeking behavior. A convenient sample of five international master students participated in the s...... and academic life and 5) social networks and support for cultural adjustment. Insights into the characteristics of international students’ information needs and behavior may help host institutions serve international students.......This report presents the first results and reflections from an exploratory case study carried out at The Royal School of Library and Information Science in 2015 on international students’ information seeking behavior. A convenient sample of five international master students participated...... in the study, including a questionnaire and in-depth interviews. The focus was on international students’ private and academic information needs and behavior ‘abroad’ in addition to their experiences of information seeking. Based on the analysis of survey data and participants’ descriptions of incidents...

  19. In situ lithium diffusion measurement in solid ionic conductors using short-lived radiotracer beam of {sup 8}Li

    Energy Technology Data Exchange (ETDEWEB)

    Ishiyama, H. [Institute of Particle and Nuclear Studies, High Energy Accelerator Research Organization (KEK), Oho 1-1, Tsukuba, Ibaraki 305-0801 (Japan); Jeong, S.C., E-mail: sunchan.jeong@kek.jp [Institute of Particle and Nuclear Studies, High Energy Accelerator Research Organization (KEK), Oho 1-1, Tsukuba, Ibaraki 305-0801 (Japan); Watanabe, Y.X.; Hirayama, Y.; Imai, N.; Miyatake, H.; Oyaizu, M. [Institute of Particle and Nuclear Studies, High Energy Accelerator Research Organization (KEK), Oho 1-1, Tsukuba, Ibaraki 305-0801 (Japan); Osa, A.; Otokawa, Y.; Matsuda, M.; Nishio, K.; Makii, H.; Sato, T.K. [Japan Atomic Energy Agency (JAEA), Shirane 2-4, Tokai, Ibaraki 319-1195 (Japan); Kuwata, N.; Kawamura, J. [Institute of Multidisciplinary Research for Advance Materials, Tohoku University, Sendai 980-8577 (Japan); Nakao, A.; Ueno, H. [Nishina Center for Accelerator-Based Science, RIKEN, Wako, Saitama 351-0198 (Japan); Kim, Y.H. [Seoul National University, Gwanak-ro, Gwanak-gu, Seoul 151-747 (Korea, Republic of); Kimura, S.; Mukai, M. [University of Tsukuba, Tsukuba, Ibaraki 305-8577 (Japan)

    2015-07-01

    We developed an in situ radiotracer method for diffusion studies in solids using short-lived α-emitting {sup 8}Li tracer. In the method, while implanting a pulsed {sup 8}Li beam into a solid material of interest, the α particles emitted into the implantation side of the sample surface were detected as a function of time. By changing the implantation depth and the detection angle against the sample surface according to lithium diffusivity (deep implantation and large angle with a large solid angle, or shallow implantation and small angle with a narrow solid angle), the method can be sensitive to a wide range of diffusion length ranging from micrometer scale to nanometer scale per second. The feasibility of the method was demonstrated by measuring the lithium diffusion coefficients to the order of 10{sup −12} cm{sup 2}/s in lithium ionic conductors.

  20. The role of electromagnetic separators in the production of radiotracers for bio-medical research and nuclear medical application

    Science.gov (United States)

    Beyer, Gerd J.; Ruth, Thomas J.

    2003-05-01

    With the growing complexity of positron emission tomography/single photon emission computed tomography imaging and the new developments in systemic radionuclide therapy there is a growing need for radioisotope preparations with higher radiochemical and radionuclidic purity that has not been achievable before. Especially important for the new applications is the specific activity of the radiotracer. Conventional methods in medical isotope production have reached their technical limitations. The role of isotope separators is discussed with examples of typical production and characterization experiments conducted at the ISOLDE and TRIUMF facilities. These preliminary experiments indicate that isotope separators have a definite role to play in the future for the production of radioisotopes for biomedical research and medical application.

  1. The role of electromagnetic separators in the production of radiotracers for bio-medical research and nuclear medical application

    CERN Document Server

    Beyer, Gerd-Jürgen

    2003-01-01

    With the growing complexity of positron emission tomography/single photon emission computed tomography imaging and the new developments in systemic radionuclide therapy there is a growing need for radioisotope preparations with higher radiochemical and radionuclidic purity that has not been achievable before. Especially important for the new applications is the specific activity of the radiotracer. Conventional methods in medical isotope production have reached their technical limitations. The role of isotope separators is discussed with examples of typical production and characterization experiments conducted at the ISOLDE and TRIUMF facilities. These preliminary experiments indicate that isotope separators have a definite role to play in the future for the production of radioisotopes for biomedical research and medical application.

  2. Efficient Removal of Ce(III and Eu(III Ions from Aqueous Solutions by Local Clay -A Radiotracer Study

    Directory of Open Access Journals (Sweden)

    Som Shankar Dubey

    2011-01-01

    Full Text Available Radiotracer technique has been used to study the removal behavior of Ce(III and Eu(III ions from aqueous solutions by local clay. Adsorptive concentration (10-4–10-6 mol dm-3, pH (ca 2.0-9.0 and temperature (303-333 K were examined for assessing optimal conditions for removal of these ions. The adsorption phenomenon was highly dependent on the amount of the adsorbent concentrations. The uptake of ions, which fitted well for Freundlich isotherm, increased with increase in the temperature and no significant desorption took place in the studied temperature range. The energy of adsorption process for the both cations indicates that the adsorption phenomenon is of chemisorption type. The rate kinetics of the adsorption followed the first order rate kinetics.

  3. Application of palladium-mediated (18F-fluorination to PET radiotracer development: overcoming hurdles to translation.

    Directory of Open Access Journals (Sweden)

    Adam S Kamlet

    Full Text Available New chemistry methods for the synthesis of radiolabeled small molecules have the potential to impact clinical positron emission tomography (PET imaging, if they can be successfully translated. However, progression of modern reactions from the stage of synthetic chemistry development to the preparation of radiotracer doses ready for use in human PET imaging is challenging and rare. Here we describe the process of and the successful translation of a modern palladium-mediated fluorination reaction to non-human primate (NHP baboon PET imaging-an important milestone on the path to human PET imaging. The method, which transforms [(18F]fluoride into an electrophilic fluorination reagent, provides access to aryl-(18F bonds that would be challenging to synthesize via conventional radiochemistry methods.

  4. UV-photochemical vapor generation of selenium for atomic absorption spectrometry: Optimization and 75Se radiotracer efficiency study

    Science.gov (United States)

    Rybínová, Marcela; Musil, Stanislav; Červený, Václav; Vobecký, Miloslav; Rychlovský, Petr

    2016-09-01

    Volatile selenium compounds were generated UV-photochemically in the continuous flow mode using four UV-photoreactors differing in the material of the reaction coil; Teflon tubing and quartz tubes with various inner diameters and wall thicknesses were tested. Atomic absorption spectrometry with an externally heated quartz furnace atomizer was employed as the detector. The relevant experimental generation parameters were optimized and the basic analytical characteristics were determined. Using formic acid as the photochemical agent, limits of detection achieved for selenium were in the range 46-102 ng L- 1 in dependence on the type of UV-photoreactor employed. When nitric acid was also added to the photochemical agent, the limits of detection were reduced to 27-44 ng L- 1. The repeatability did not exceed 2.4% (5 μg L- 1 Se(IV), n = 10). Experiments with 75Se radiotracer have been performed for the first time to quantify the efficiency of UV-photochemical vapor generation (UV-PVG) of selenium. The highest efficiency of 67 ± 1% was obtained for a UV-photoreactor containing a quartz reaction coil (2.0 mm i.d., 4.0 mm o.d.). The generation efficiency of 61 ± 1% was obtained for a Teflon reaction coil (1.0 mm i.d., 1.4 mm o.d.). Mapping of the radiotracer distribution in the individual parts of the apparatus did not reveal substantial transport losses of the analyte in the UV-PVG system.

  5. Preclinical Comparative Study of (68)Ga-Labeled DOTA, NOTA, and HBED-CC Chelated Radiotracers for Targeting PSMA.

    Science.gov (United States)

    Ray Banerjee, Sangeeta; Chen, Zhengping; Pullambhatla, Mrudula; Lisok, Ala; Chen, Jian; Mease, Ronnie C; Pomper, Martin G

    2016-06-15

    (68)Ga-labeled, low-molecular-weight imaging agents that target the prostate-specific membrane antigen (PSMA) are increasingly used clinically to detect prostate and other cancers with positron emission tomography (PET). The goal of this study was to compare the pharmacokinetics of three PSMA-targeted radiotracers: (68)Ga-1, using DOTA-monoamide as the chelating agent; (68)Ga-2, containing the macrocyclic chelating agent p-SCN-Bn-NOTA; and (68)Ga-DKFZ-PSMA-11, currently in clinical trials, which uses the acyclic chelating agent, HBED-CC. The PSMA-targeting scaffold for all three agents utilized a similar Glu-urea-Lys-linker construct. Each radiotracer enabled visualization of PSMA+ PC3 PIP tumor, kidney, and urinary bladder as early as 15 min post-injection using small animal PET/computed tomography (PET/CT). (68)Ga-2 demonstrated the fastest rate of clearance from all tissues in this series and displayed higher uptake in PSMA+ PC3 PIP tumor compared to (68)Ga-1 at 1 h post-injection. There was no significant difference in PSMA+ PC3 PIP tumor uptake for the three agents at 2 and 3 h post-injection. (68)Ga-DKFZ-PSMA-11 demonstrated the highest uptake and retention in normal tissues, including kidney, blood, spleen, and salivary glands and PSMA-negative PC3 flu tumors up to 3 h post-injection. In this preclinical evaluation (68)Ga-2 had the most advantageous characteristics for PSMA-targeted PET imaging.

  6. Effect of cyclosporin A on the uptake of D{sub 3}-selective PET radiotracers in rat brain

    Energy Technology Data Exchange (ETDEWEB)

    Tu Zhude; Li Shihong; Xu Jinbin; Chu Wenhua; Jones, Lynne A. [Department of Radiology, Washington University School of Medicine, St. Louis, MO 63110 (United States); Luedtke, Robert R. [Department of Pharmacology and Neuroscience, University of North Texas Health Science Center, Fort Worth, TX 76107 (United States); Mach, Robert H., E-mail: rhmach@mir.wustl.edu [Department of Radiology, Washington University School of Medicine, St. Louis, MO 63110 (United States); Department of Cell Biology and Physiology, Washington University School of Medicine, St. Louis, MO 63110 (United States); Department of Biochemistry and Molecular Biophysics, Washington University School of Medicine, St. Louis, MO 63110 (United States)

    2011-07-15

    Introduction: Four benzamide analogs having a high affinity and selectivity for D{sub 3} versus D{sub 2} receptors were radiolabeled with {sup 11}C or {sup 18}F for in vivo evaluation. Methods: Precursors were synthesized, and the four D{sub 3} selective benzamide analogs were radiolabeled. The tissue distribution and brain uptake of the four compounds were evaluated in control rats and rats pretreated with cyclosporin A, a modulator of P-glycoprotein and an inhibitor of other ABC efflux transporters that contribute to the blood brain barrier. Micro-positron emission tomographic (PET) imaging was carried out for [{sup 11}C]6 in a control and a cyclosporin A pretreated rat. Results: All four compounds showed low brain uptake in control rats at 5 and 30 min post-injection; despite recently reported rat behavioral studies conducted on analogs 6 (WC-10) and 7 (WC-44). Following administration of cyclosporin A, increased brain uptake was observed with all four PET radiotracers at both 5 and 30 min post-intravenous injection. An increase in brain uptake following modulation/inhibition of the ABC transporters was also observed in the microPET study. Conclusions: These data suggest that D3 selective conformationally-flexible benzamide analogs which contain a N-2-methoxyphenylpiperazine moiety are substrates for P-glycoprotein or other adenosine triphosphate (ATP)-binding cassette transporters expressed at the blood-brain barrier, and that PET radiotracers containing this pharmacophore may display low brain uptake in rodents due to the action of these efflux transporters.

  7. Strategic Asset Seeking by EMNEs

    DEFF Research Database (Denmark)

    Petersen, Bent; Seifert, Jr., Rene E.

    2014-01-01

    as the more relevant concept to use when explaining strategic asset seeking of EMNEs. A set of propositions are formulated to guide empirical testing. Originality/value: The insights gained from using the springboard perspective and the LOO concept are non-trivial: They basically predict future dominance...

  8. CHINA SEEKS REGIONAL ENERGY COOPERATION

    Institute of Scientific and Technical Information of China (English)

    2012-01-01

    China is seeking to diversify channels for energy cooperation as it faces mounting challenges from surging energy demand, geopolitical risks and price volatility. The endowment and distribution of China's resources does not match the current situation of China's economic development. Those are the opinions aired by officials and experts at an international expo recently held in West China's Xinjiang Uygur Autonomous Region.

  9. Improving radionuclide therapy in prostate cancer patients with metastatic bone pain

    NARCIS (Netherlands)

    Lam, M.G.E.H.

    2009-01-01

    Bone seeking radiopharmaceuticals are indicated in cancer patients with multiple painful skeletal metastases. The majority of these patients are hormone-refractory prostate cancer patients in an advanced stage of their disease. Bone seeking radiopharmaceuticals relieve pain and improve the patients

  10. [{sup 123}I]-3-Iodcytisin as possible radiotracer for the imaging of nicotinic acetylcholine receptors using single photon emission computer tomography; [{sup 123}I]-3-Iodcytisin als moeglicher Radiotracer fuer die Darstellung der nikotinergen Acetylcholin Rezeptoren mittels Single-Photon-Emissions-Computertomographie

    Energy Technology Data Exchange (ETDEWEB)

    Paulik, Dagmar Julia

    2015-03-06

    For the synthesis of [{sup 123}I]-3-Iodcytisin as possible radiotracer for the imaging of nicotinic acetylcholine (nACh) receptors using SPECT two different technologies were used: the radio-iodination with iodogen and the radio-iodination with nitric acid. The latter one showed higher efficiency. The radiotracer will allow to detect degenerative processes and other nACh-depending diseases in the brain (Alzheimer, Parkinson) and to observe the progress. The autoradiography is aimed to the imaging of the nACh receptors in the brain bypassing the brain-blood barrier. The highest activity was measured in the thalamus of mice and rat brains.

  11. Focal hot spot induced by a central subclavian line on bone scan

    Directory of Open Access Journals (Sweden)

    Masood Moslehi

    2014-01-01

    Full Text Available The diagnostic accuracy of nuclear medicine reporting can be improved by awareness of these instrument-related artifacts. Both awareness and experience are also important when it comes to detecting and identifying normal (and abnormal variants. We present a case of hot spot on the upper right chest in the region of right subclavicular region resulting from injection of radiotracer from central subclavian line. A 52-year-old woman with a history of left breast cancer and recent bone pain was referred to our nuclear medicine department for skeletal survey. Anterior views of chest show a focus of increased radiotracer uptake corresponding to anterior arch of one of the right second rib. The nuclear physician reported it as a focal rib bony lesion and recommended radiological evaluation. As technician later explained, physicians realized that injection site was a central subclavian line on the right side and hot spot on that region is due to injection site. The appearance of both skeletal and soft-tissue uptake depends heavily on imaging technique (such as the route of radiotracer administration and the interpreting physicians should be aware of the impact of technical factors on image quality.

  12. International students’ information seeking behavior

    DEFF Research Database (Denmark)

    Hyldegård, Jette Seiden

    2016-01-01

    This report presents the first results and reflections from an exploratory case study carried out at The Royal School of Library and Information Science in 2015 on international students’ information seeking behavior. A convenient sample of five international master students participated...... in the study, including a questionnaire and in-depth interviews. The focus was on international students’ private and academic information needs and behavior ‘abroad’ in addition to their experiences of information seeking. Based on the analysis of survey data and participants’ descriptions of incidents...... and academic life and 5) social networks and support for cultural adjustment. Insights into the characteristics of international students’ information needs and behavior may help host institutions serve international students....

  13. Novel methodology for the study of mercury methylation and reduction in sediments and water using {sup 197}Hg radiotracer

    Energy Technology Data Exchange (ETDEWEB)

    Ribeiro Guevara, Sergio; Perez Catan, Soledad [Centro Atomico Bariloche, Laboratorio de Analisis por Activacion Neutronica, Bariloche (Argentina); Zizek, Suzana; Repinc, Urska; Jacimovic, Radojko; Horvat, Milena [Jozef Stefan Institute, Department of Environmental Sciences, Ljubljana (Slovenia)

    2007-03-15

    Mercury tracers are powerful tools that can be used to study mercury transformations in environmental systems, particularly mercury methylation, demethylation and reduction in sediments and water. However, mercury transformation studies using tracers can be subject to error, especially when used to assess methylation potential. The organic mercury extracted can be as low as 0.01% of the endogenous labeled mercury, and artefacts and contamination present during methylmercury (MeHg) extraction processes can cause interference. Solvent extraction methods based on the use of either KBr/H{sub 2}SO{sub 4} or HCl were evaluated in freshwater sediments using {sup 197}Hg radiotracer. Values obtained for the {sup 197}Hg tracer in the organic phase were up to 25-fold higher when HCl was used, which is due to the coextraction of {sup 197}Hg{sup 2+} into the organic phase during MeHg extraction. Evaluations of the production of MeHg gave similar results with both MeHg extraction procedures, but due to the higher Hg{sup 2+} contamination of the controls, the uncertainty in the determination was higher when HCl was used. The Hg{sup 2+} contamination of controls in the HCl extraction method showed a nonlinear correlation with the humic acid content of sediment pore water. Therefore, use of the KBr/H{sub 2}SO{sub 4} method is recommended, since it is free from these interferences. {sup 197}Hg radiotracer (T{sub 1/2} = 2.673 d) has a production rate that is about 50 times higher than that of {sup 203}Hg (T{sub 1/2} = 46.595 d), the most frequently used mercury radiotracer. Hence it is possible to obtain a similar level of performance to {sup 203}Hg when it is used it in short-term experiments and produced by the irradiation of {sup 196}Hg with thermal neutrons, using mercury targets with the natural isotopic composition. However, if the 0.15% natural abundance of the {sup 196}Hg isotope is increased, the specific activity of the {sup 197}Hg tracer can be significantly improved. In

  14. Novel methodology for the study of mercury methylation and reduction in sediments and water using 197Hg radiotracer.

    Science.gov (United States)

    Ribeiro Guevara, Sergio; Zizek, Suzana; Repinc, Urska; Pérez Catán, Soledad; Jaćimović, Radojko; Horvat, Milena

    2007-03-01

    Mercury tracers are powerful tools that can be used to study mercury transformations in environmental systems, particularly mercury methylation, demethylation and reduction in sediments and water. However, mercury transformation studies using tracers can be subject to error, especially when used to assess methylation potential. The organic mercury extracted can be as low as 0.01% of the endogenous labeled mercury, and artefacts and contamination present during methylmercury (MeHg) extraction processes can cause interference. Solvent extraction methods based on the use of either KBr/H2SO4 or HCl were evaluated in freshwater sediments using 197Hg radiotracer. Values obtained for the 197Hg tracer in the organic phase were up to 25-fold higher when HCl was used, which is due to the coextraction of 197Hg2+ into the organic phase during MeHg extraction. Evaluations of the production of MeHg gave similar results with both MeHg extraction procedures, but due to the higher Hg2+ contamination of the controls, the uncertainty in the determination was higher when HCl was used. The Hg2+ contamination of controls in the HCl extraction method showed a nonlinear correlation with the humic acid content of sediment pore water. Therefore, use of the KBr/H2SO4 method is recommended, since it is free from these interferences. 197Hg radiotracer (T1/2=2.673 d) has a production rate that is about 50 times higher than that of 203Hg (T1/2=46.595 d), the most frequently used mercury radiotracer. Hence it is possible to obtain a similar level of performance to 203Hg when it is used it in short-term experiments and produced by the irradiation of 196Hg with thermal neutrons, using mercury targets with the natural isotopic composition. However, if the 0.15% natural abundance of the 196Hg isotope is increased, the specific activity of the 197Hg tracer can be significantly improved. In the present work, 197Hg tracer was produced from mercury 51.58% enriched in the 196Hg isotope, and a 340-fold

  15. Predictors of help‐seeking behavior: Distinction between help‐seeking intentions and help‐seeking behavior

    National Research Council Canada - National Science Library

    Nagai, Satoru

    2015-01-01

    The overall goals of this research were to: (a) examine whether help‐seeking intentions, subjective needs, depressive symptoms, and social support can predict actual help‐seeking behavior; and (b...

  16. Predicting job-seeking intensity and job-seeking intention in the sample of unemployed

    Directory of Open Access Journals (Sweden)

    Marić Zorica

    2005-01-01

    Full Text Available In this study Ajzen' theory (1991 of planned behavior was used to predict job - seek intention and behavior among unemployed people (N = 650. In addition to theory of planned behavior variables (job - seek attitude, subjective norm, self - efficacy and controllability of job seek process we used several other psychological (financial pressure, self - mastery, self - esteem and depression and demographic (gender, age, education, marriage and lent of unemployment variables to build a model of predictors for both criterion variables. Financial pressure, intention to seek employment, job seek - self - efficacy, job - seek controllability, marriage and job - seek attitude predicted job - seeking behavior, while attitude toward job - seeking, subjective norm, job - seek self - efficacy and financial pressure predicted job seek - intention. Results are discussed in light of theory of planned behavior, current research of job - seeking behavior and recommendations are made for practice.

  17. Bone cutting.

    Science.gov (United States)

    Giraud, J Y; Villemin, S; Darmana, R; Cahuzac, J P; Autefage, A; Morucci, J P

    1991-02-01

    Bone cutting has always been a problem for surgeons because bone is a hard living material, and many osteotomes are still very crude tools. Technical improvement of these surgical tools has first been their motorization. Studies of the bone cutting process have indicated better features for conventional tools. Several non-conventional osteotomes, particularly ultrasonic osteotomes are described. Some studies on the possible use of lasers for bone cutting are also reported. Use of a pressurised water jet is also briefly examined. Despite their advantages, non-conventional tools still require improvement if they are to be used by surgeons.

  18. Development of a system for real-time measurements of metabolite transport in plants using short-lived positron-emitting radiotracers

    Science.gov (United States)

    Kiser, Matthew R.

    Over the past 200 years, the Earth's atmospheric carbon dioxide (CO 2) concentration has increased by more than 35%, and climate experts predict that CO2 levels may double by the end of this century. Understanding the mechanisms of resource management in plants is fundamental for predicting how plants will respond to the increase in atmospheric CO 2. Plant productivity sustains life on Earth and is a principal component of the planet's system that regulates atmospheric CO2 concentration. As such, one of the central goals of plant science is to understand the regulatory mechanisms of plant growth in a changing environment. Short-lived positron-emitting radiotracer techniques provide time-dependent data that are critical for developing models of metabolite transport and resource distribution in plants and their microenvironments. To better understand the effects of environmental changes on resource transport and allocation in plants, we have developed a system for real-time measurements of rnetabolite transport in plants using short-lived positron-emitting radio-tracers. This thesis project includes the design, construction, and demonstration of the capabilities of this system for performing real-time measurements of metabolite transport in plants. The short-lived radiotracer system described in this dissertation takes advantage of the combined capabilities and close proximity of two research facilities at. Duke University: the Triangle Universities Nuclear Laboratory (TUNL) and the Duke University Phytotron, which are separated by approximately 100 meters. The short-lived positron-emitting radioisotopes are generated using the 10-MV tandem Van de Graaff accelerator located in the main TUNL building, which provides the capability of producing short-lived positron-emitting isotopes such as carbon-11 (11C: 20 minute half-life), nitrogen-13 (13N; 10 minute half-life), fluorine-18 (18F; 110 minute half-life), and oxygen-15 (15O; 2 minute half-life). The radioisotopes may

  19. Estimating Endogenous Dopamine Levels at D2 and D3 Receptors in Humans using the Agonist Radiotracer [11C]-(+)-PHNO

    Science.gov (United States)

    Caravaggio, Fernando; Nakajima, Shinichiro; Borlido, Carol; Remington, Gary; Gerretsen, Philip; Wilson, Alan; Houle, Sylvain; Menon, Mahesh; Mamo, David; Graff-Guerrero, Ariel

    2014-01-01

    Using positron emission tomography (PET) and an acute dopamine depletion challenge it is possible to estimate endogenous dopamine levels occupying dopamine D2/3 receptors (D2/3R) in humans in vivo. Our group has developed [11C]-(+)-PHNO, the first agonist radiotracer with preferential in vivo affinity for D3R. Thus, the use of [11C]-(+)-PHNO offers the novel possibility of (i) estimating in vivo endogenous dopamine levels at D2/3R using an agonist radiotracer, and (ii) estimating endogenous dopamine levels at D3R in extrastriatal regions such as the substantia nigra, hypothalamus, and ventral pallidum. Ten healthy participants underwent a [11C]-(+)-PHNO PET scan under baseline conditions and another under acute endogenous dopamine depletion achieved via oral administration of alpha-methyl-para-tyrosine (64 mg/kg). [11C]-(+)-PHNO binding was sensitive to acute dopamine depletion, allowing in vivo estimates of endogenous dopamine in D2R-rich regions (caudate and putamen), mixed D2/3R-rich regions (ventral striatum and globus pallidus), and extrastriatal D3R-rich regions (hypothalamus and ventral pallidum). Dopamine depletion decreased self-reported vigor, which was correlated with the reduction in dopamine levels in the globus pallidus. [11C]-(+)-PHNO is a suitable radiotracer for use in estimating endogenous dopamine levels at D2R and D3R in neuropsychiatric populations. PMID:24874713

  20. Estimating endogenous dopamine levels at D2 and D3 receptors in humans using the agonist radiotracer [(11)C]-(+)-PHNO.

    Science.gov (United States)

    Caravaggio, Fernando; Nakajima, Shinichiro; Borlido, Carol; Remington, Gary; Gerretsen, Philip; Wilson, Alan; Houle, Sylvain; Menon, Mahesh; Mamo, David; Graff-Guerrero, Ariel

    2014-11-01

    Using positron emission tomography (PET) and an acute dopamine depletion challenge it is possible to estimate endogenous dopamine levels occupying dopamine D2/3 receptors (D2/3R) in humans in vivo. Our group has developed [(11)C]-(+)-PHNO, the first agonist radiotracer with preferential in vivo affinity for D3R. Thus, the use of [(11)C]-(+)-PHNO offers the novel possibility of (i) estimating in vivo endogenous dopamine levels at D2/3R using an agonist radiotracer, and (ii) estimating endogenous dopamine levels at D3R in extrastriatal regions such as the substantia nigra, hypothalamus, and ventral pallidum. Ten healthy participants underwent a [(11)C]-(+)-PHNO PET scan under baseline conditions and another under acute endogenous dopamine depletion achieved via oral administration of alpha-methyl-para-tyrosine (64 mg/kg). [(11)C]-(+)-PHNO binding was sensitive to acute dopamine depletion, allowing in vivo estimates of endogenous dopamine in D2R-rich regions (caudate and putamen), mixed D2/3R-rich regions (ventral striatum and globus pallidus), and extrastriatal D3R-rich regions (hypothalamus and ventral pallidum). Dopamine depletion decreased self-reported vigor, which was correlated with the reduction in dopamine levels in the globus pallidus. [(11)C]-(+)-PHNO is a suitable radiotracer for use in estimating endogenous dopamine levels at D2R and D3R in neuropsychiatric populations.

  1. Potential therapeutic radiotracers: preparation, biodistribution and metabolic characteristics of 177Lu-labeled cyclic RGDfK dimer.

    Science.gov (United States)

    Shi, Jiyun; Liu, Zhaofei; Jia, Bing; Yu, Zilin; Zhao, Huiyun; Wang, Fan

    2010-06-01

    In this study, we reported the preparation and evaluation of (177)Lu-DOTA-RGD2, (177)Lu-DOTA-Bz-RGD2 and (177)Lu-DTPA-Bz-RGD2 (RGD2 = E[c(RGDfK)](2)) as a potential therapeutic radiotracers for the treatment of integrin alpha(v)beta(3)-positive tumors. The BALB/c nude mice bearing the U87MG human glioma xenografts were used to evaluate the biodistribution characteristics and excretion kinetics of (177)Lu-DOTA-RGD2, (177)Lu-DOTA-Bz-RGD2 and (177)Lu-DTPA-Bz-RGD2. It was found that there were no major differences in their lipophilicity and biodistribution characteristics, particularly at latter time points. A major advantage of using DTPA-Bz as the bifunctional chelator (BFC) was its high radiolabeling efficiency (fast and high yield radiolabeling) at room temperature. Using DOTA and DOTA-Bz as BFCs, the radiolabeling kinetics was slow, and heating at 100 degrees C and higher DOTA-conjugate concentration were needed for successful (177)Lu-labeling. Therefore, DTPA-Bz is an optimal BFC for routine preparation of (177)Lu-labeled cyclic RGDfK peptides, and (177)Lu-DTPA-Bz-RGD2 is worthy of further investigation for targeted radiotherapy of integrin alpha(v)beta(3)-positive tumors.

  2. Optimizing tumor targeting of the lipophilic EGFR-binding radiotracer SKI 243 using a liposomal nanoparticle delivery system.

    Science.gov (United States)

    Medina, Oula Penate; Pillarsetty, Nagavarakishore; Glekas, Athanasios; Punzalan, Blesida; Longo, Valerie; Gönen, Mithat; Zanzonico, Pat; Smith-Jones, Peter; Larson, Steven M

    2011-02-10

    Positron emission tomography (PET) of epidermal growth factor receptor (EGFR) kinase-specific radiolabeled tracers could provide a means for non-invasively characterizing EGFR expression and signaling activity in patients' tumors before, during, and after therapy with EGFR inhibitors. Towards this goal, our group has developed PET tracers which irreversibly bind to EGFR. However, tumor uptake is relatively low because of both the lipophilicity of such tracers (e.g. the morpholino-[124I]-IPQA [SKI 212243]), with octanol-to-water partition coefficients of up to 4, and a short dwell time in the blood and significant hepatobiliary clearance and intestinal reuptake. Liposomal nanoparticle delivery systems may favorably alter the pharmacokinetic profile and improve tumor targeting of highly lipophilic but otherwise promising cancer imaging tracers, such as the EGFR inhibitor SKI 243. SKI 243 is therefore an interesting model molecule for incorporation into lipid-based nanoparticles, as it would not only improve their solubility but also increase the circulation time, availability and, potentially, targeting of tumors. In the current study, we compared the pharmacokinetics and tumor targeting of the bare EGFR kinase-targeting radiotracer SKI 212243 (SKI 243) with that of the same tracer embedded in liposomes. SKI 243 and liposomal SKI 243 are both taken up by tumor xenografts but liposomal SKI 243 remained in the blood longer and consequently exhibited a 3- to 6-fold increase in uptake in the tumor among several other organs.

  3. Financial Literacy, Confidence and Financial Advice Seeking

    NARCIS (Netherlands)

    Kramer, Marc M.

    2016-01-01

    We find that people with higher confidence in their own financial literacy are less likely to seek financial advice, but no relation between objective measures of literacy and advice seeking. The negative association between confidence and advice seeking is more pronounced among wealthy households.

  4. Whole body bone scintigraphy in tenofovir-related osteomalacia: a case report

    Directory of Open Access Journals (Sweden)

    Di Biagio Antonio

    2009-07-01

    Full Text Available Abstract Introduction Tenofovir disoproxil fumarate (Viread® is the only nucleotide reverse transcriptase inhibitor currently approved for the treatment of HIV. It is frequently prescribed not only for its efficacy but also for its decreased side effect profile compared with other nucleotide analogs. In addition, it is now increasingly recognized as a cause of acquired Fanconi's syndrome in individuals with HIV. Case presentation We describe a 48-year-old woman infected with HIV, with chronic renal insufficiency, who developed Fanconi's syndrome after inclusion of tenofovir disoproxil fumarate in her antiretroviral therapy. A whole body bone scintigraphy was performed, revealing an abnormal distribution of radiotracer uptake, with characteristic changes compatible with osteomalacia. All symptoms disappeared after tenofovir discontinuation and mineral supplementation. No other explanation for the sudden and complete resolution of the bone disease was found. Conclusion The case highlights the role of whole body bone scintigraphy in the diagnosis of tenofovir-related osteomalacia.

  5. Aneurysmal bone cyst of the mandible managed by conservative surgical therapy with preoperative embolization

    Energy Technology Data Exchange (ETDEWEB)

    An, Seo Young [School of Dentistry, Kyungpook National University, Daegu (Korea, Republic of)

    2012-03-15

    A 9-year-old girl visited our hospital, complaining of a rapid-growing and rigid swelling on the left posterior mandibular area. Panoramic radiograph showed a moderately defined multilocular honeycomb appearance involving the left mandibular body. CT scan revealed an expansile, multilocular osteolytic lesion and multiple fluid levels within cystic spaces. Bone scan demonstrated increased radiotracer uptake and angiography showed a highly vascularized lesion. The lesion was suspected as aneurysmal bone cyst (ABC) and preoperative embolization was performed, which minimize the extent of operation and the surgical complication. The lesion was treated by surgical curettage and lateral decortication with repositioning. No additional treatment such as a surgical reconstruction or bone graft was needed. Early diagnosis of ABC is very important and appropriate treatment should be performed considering several factors such as age, surgical complication, and possibility of recurrence.

  6. Determination of oil reservoir radiotracer (S{sup 14}CN{sup -}) in a single step using a plastic scintillator extractive resin

    Energy Technology Data Exchange (ETDEWEB)

    Bagan, H.; Tarancon, A. [Departament de Quimica Analitica, Universitat de Barcelona, Diagonal 645, E-08028 Barcelona (Spain); Stavsetra, L. [Department for Reservoir and Exploration Technology, Institute for Energy Technology (IFE), Instituttveien 18, N-2027 Kjeller (Norway); Rauret, G. [Departament de Quimica Analitica, Universitat de Barcelona, Diagonal 645, E-08028 Barcelona (Spain); Garcia, J.F., E-mail: jfgarcia@ub.edu [Departament de Quimica Analitica, Universitat de Barcelona, Diagonal 645, E-08028 Barcelona (Spain)

    2012-07-29

    Highlights: Black-Right-Pointing-Pointer A new procedure for S{sup 14}CN{sup -} radiotracer determination using PS resin was established. Black-Right-Pointing-Pointer The minimum detectable activity for a 100 mL sample is 0.08 Bq L{sup -1}. Black-Right-Pointing-Pointer The minimum quantifiable activity for a 100 mL sample is 0.31 Bq L{sup -1}. Black-Right-Pointing-Pointer PS resin is capable to quantify S{sup 14}CN{sup -} radiotracer samples with errors lower than 5%. Black-Right-Pointing-Pointer PS resin is also capable to quantify complex matrices obtained from oil reservoirs. - Abstract: The analysis of radiotracers is important in the study of oil reservoir dynamics. One of the most widely used radiotracer is S{sup 14}CN{sup -}. Prior to activity measurements by Liquid Scintillation (LS), routine determinations require the pretreatment steps of purification and concentration of the samples using anion exchange columns. The final elution media produces samples with high salt concentration that may lead to problems with phase separation during the LS measurement. Plastic Scintillation (PS) is an alternative technique that provides a solid surface that can be used as a platform for the immobilisation of selective extractants to obtain a PS resin. The proposed procedure unifies chemical separation and sample measurement preparation in a single step, serving to reduce the number of reagents needed and manpower required for the analysis while also avoiding mixed waste production by LS. The objective of this study is to develop a PS resin for the determination of {sup 14}C-labelled thiocyanate radiotracer in water samples. For this purpose, the immobilisation procedure was optimised, including optimisation of the proportion of PS microspheres:extractant and the use of a control blank to monitor the PS resin immobilisation process. The breakthrough volume was studied and the detection and quantification limits for 100 mL of sample were determined to be 0.08 Bq L{sup -1

  7. Brain SPECT imaging and whole-body biodistribution with [{sup 123}I]ADAM - a serotonin transporter radiotracer in healthy human subjects

    Energy Technology Data Exchange (ETDEWEB)

    Lin, K.-J. [Graduate Institute of Clinical Medical Sciences, Chang-Gung University, Tao-Yuan 333, Taiwan (China); Molecular Imaging Center, Chang-Gung Memorial Hospital, Tao-Yuan 333, Taiwan (China); Department of Nuclear Medicine, Chang-Gung Memorial Hospital, Tao-Yuan 333, Taiwan (China); Liu, C.-Y. [Neuroscience Research Center, Chang-Gung Memorial Hospital, Tao-Yuan 333, Taiwan (China); Department of Psychiatry, Chang-Gung Memorial Hospital, Tao-Yuan 333, Taiwan (China); Wey, S.-P. [Molecular Imaging Center, Chang-Gung Memorial Hospital, Tao-Yuan 333, Taiwan (China); Department of Medical Imaging and Radiological Sciences, Chang-Gung University, Tao-Yuan 333, Taiwan (China); Hsiao, I.-T. [Molecular Imaging Center, Chang-Gung Memorial Hospital, Tao-Yuan 333, Taiwan (China); Department of Medical Imaging and Radiological Sciences, Chang-Gung University, Tao-Yuan 333, Taiwan (China); Wu, Jay [Health Physics Divisions, Atomic Energy Council, Institute of Nuclear Energy Research, Tao-Yuan 325, Taiwan (China); Fu, Y.-K. [Atomic Energy Council, Institute of Nuclear Energy Research, Tao-Yuan 325, Taiwan (China); Yen, T.-C. [Molecular Imaging Center, Chang-Gung Memorial Hospital, Tao-Yuan 333, Taiwan (China) and Department of Nuclear Medicine, Chang-Gung Memorial Hospital, Tao-Yuan 333, Taiwan (China)]. E-mail: yen1110@adm.cgmh.org.tw

    2006-02-15

    Introduction: [{sup 123}I]-2-((2-((dimethylamino)methyl)phenyl)thio)-5-iodophenylamine ([{sup 123}I]ADAM), a novel radiotracer, has promising application in the imaging of the serotonin transporter (SERT) in the human brain. In this study, the optimal scanning time for acquiring brain single photon emission computed tomography (SPECT) images was determined by performing dynamic SPECT studies at intervals from 0 to 6 h postinjection of [{sup 123}I]ADAM. Additionally, radiation-absorbed doses were determined for three healthy human subjects using attenuation-corrected images. Methods: Twelve subjects were randomized into one of three study groups as follows: whole-body distribution imaging (n=3), dynamic SPECT imaging (n=3) and brain SPECT imaging (n=6). The radiation-absorbed dose was calculated using MIRDOSE 3.0 software with attenuation-corrected data. The specific binding (SB) ratio of the brain stem was measured from dynamic SPECT images to determine the optimal scanning time. Results: Dynamic SPECT images showed that the SB of the brain stem gradually increased to a maximum 4 h postinjection. Single photon emission computed tomography images at 4 h postinjection showed a high uptake of the radiotracer (SB) in the hypothalamus (1.40{+-}0.12), brain stem (1.44{+-}0.16), pons (1.13{+-}0.14) and medial temporal lobe (0.59{+-}0.10). The mean adult male value of effective dose was 3.37x10{sup -2} mSv/MBq with a 4.8-h urine-voiding interval. Initial high uptake in SERT-rich sites was demonstrated in the lung and brain. A prominent washout of the radiotracer from the lung further increased brain radioactivity that reached a peak value of 5.03% of injected dose 40 min postinjection. Conclusions: [{sup 123}I]ADAM is a promising radiotracer for SPECT imaging of SERT in humans with acceptable dosimetry and high uptake in SERT-rich regions. Brain SPECT images taken within 4 h following injection show optimal levels of radiotracer uptake in known SERT sites. However, dynamic

  8. A rare case of polyostotic fibrous dysplasia assessed by bone scintigraphy with Tc-99m methylene diphosphonate (MDP)

    Energy Technology Data Exchange (ETDEWEB)

    Di Leo, C.; Ardemagni, A.; Bestetti, A.; Tagliabue, L.; Del Sole, A.; Conte, A.; Tarolo, G.L. [Milano Univ. (Italy). Servizio di Medicina Nucleare

    1999-07-01

    A 66-year-old man affected by polyostotic form of fibrous dysplasia in consequence of worsening of lower extremity bone pain aggravated by walking and concomitant increase of serum alkaline phosphatase and osteocalcin, was subjected first to a radionuclide study. Bone scan demonstrated a pathological uptake of the radiotracer in the craniofacial bones, right scapula, left and right posterior ribs, right hemipelvis and lower extremities confirming the diagnosis but establishing especially the extent of bone involvement, greater than expected on the basis of symptoms and X-ray findings, underlying the importance of nuclear medicine imaging in the assessment and follow-up of this rare disease. (orig.) [German] Bei einem 66jaehrigen Mann, der an der polyostotischen Form der fibroesen Dysplasie leidet, wurde aufgrund einer Verschlimmerung der Knochenschmerzen im Bereich der unteren Extremitaeten, die sich beim Gehen verschlechterten, und einer gleichzeitigen Erhoehung der Serumwerte fuer alkalische Phosphatase und Osteocalzin erstmals eine Radionuklid-Untersuchung durchgefuehrt. Das Knochenszintigramm zeigte eine pathologische Aufnahme des Radiotracers in den kraniofazialen Knochen, im rechten Schulterblatt, den linken und rechten posterioren Rippen, im Bereich von rechtem Hemipelvis und unteren Extremitaeten; damit wird die Diagnose bestaetigt, vor allem jedoch das Ausmass der Knochenbeteiligung nachgewiesen, das ueber das ausgehend von den Symptomen und Roentgenbefunden erwartete Ausmass hinausgeht; die Bedeutung des nuklearmedizinischen bildgebenden Verfahrens zur Beurteilung und Verlaufskontrolle dieser seltenen Erkrankung wird dadurch unterstrichen. (orig.)

  9. Preliminary results of automated removal of degenerative joint disease in bone scan lesion segmentation

    Science.gov (United States)

    Chu, Gregory H.; Lo, Pechin; Kim, Hyun J.; Auerbach, Martin; Goldin, Jonathan; Henkel, Keith; Banola, Ashley; Morris, Darren; Coy, Heidi; Brown, Matthew S.

    2013-03-01

    Whole-body bone scintigraphy (or bone scan) is a highly sensitive method for visualizing bone metastases and is the accepted standard imaging modality for detection of metastases and assessment of treatment outcomes. The development of a quantitative biomarker using computer-aided detection on bone scans for treatment response assessment may have a significant impact on the evaluation of novel oncologic drugs directed at bone metastases. One of the challenges to lesion segmentation on bone scans is the non-specificity of the radiotracer, manifesting as high activity related to non-malignant processes like degenerative joint disease, sinuses, kidneys, thyroid and bladder. In this paper, we developed an automated bone scan lesion segmentation method that implements intensity normalization, a two-threshold model, and automated detection and removal of areas consistent with non-malignant processes from the segmentation. The two-threshold model serves to account for outlier bone scans with elevated and diffuse intensity distributions. Parameters to remove degenerative joint disease were trained using a multi-start Nelder-Mead simplex optimization scheme. The segmentation reference standard was constructed manually by a panel of physicians. We compared the performance of the proposed method against a previously published method. The results of a two-fold cross validation show that the overlap ratio improved in 67.0% of scans, with an average improvement of 5.1% points.

  10. Bone x-ray

    Science.gov (United States)

    ... or broken bone Bone tumors Degenerative bone conditions Osteomyelitis (inflammation of the bone caused by an infection) ... Multiple myeloma Osgood-Schlatter disease Osteogenesis imperfecta Osteomalacia Osteomyelitis Paget disease of the bone Rickets X-ray ...

  11. The role of radioisotopes for the palliation of bone pain from bone metastases

    Institute of Scientific and Technical Information of China (English)

    YANG Ji-gang; LI Chun-lin

    2006-01-01

    Bone metastasis occurs as a result of a complex pathophysiologic process between host and tumor cells leading to cellular invasion, migration adhesion, and stimulation of osteoclastic and osteoblastic activity. Several sequences occur as a result of osseous metastases and resulting bone pain can lead to significant debilitation. Pain associated with osseous metastasis is thought to be distinct from neuropathic or inflammatory pain. Several mechanisms, such as invasion of tumor cells, spinal cord astrogliosis,and sensitization of nervous system, have been postulated to cause pain. Pharmaceutical therapy of bone pain includes nonsteroidal analgesics and opiates. These drags are associated with side effects, and tolerance to these agents necessitates treatment with other modalities. Bisphosphonates act by inhibiting osteoclast-mediated resorption and have been increasingly used in treatment of painful bone metastasis. While external beam radiation therapy remains the mainstay of pain palliation of solitary lesions, bone-seeking radiopharmaceuticals have entered the therapeutic armamentarium for the treatment of multiple painful osseous lesions. 32p has been used for over 3 decades in the treatment of multiple osseous metastases. The myelosuppression caused by this agent has led to the development of other bone-seeking radiopharmaceuticals, including 89SrCl, and 153Sm-ethylenediaminetetramethylene phosphonic acid (153Sm-EDTMP). 89Sr is a bone-seeking radionuclide, whereas 153Sm-EDTMP is a bone-seeking tetraphosphonate; both have been approved by the Food and Drug Administration for the treatment of painful osseous metastases. While both agents have been shown to have efficacy in the treatment of painful osseous metastases from prostate cancer, they may also have utility in the treatment of painful osseous metastases from breast cancer and perhaps from non-small cell lung cancer. This article illustrates the salient features of these radiopharmaceuticals, including the

  12. Bone pain

    DEFF Research Database (Denmark)

    Frost, Charlotte Ørsted; Hansen, Rikke Rie; Heegaard, Anne-Marie

    2016-01-01

    Skeletal conditions are common causes of chronic pain and there is an unmet medical need for improved treatment options. Bone pain is currently managed with disease modifying agents and/or analgesics depending on the condition. Disease modifying agents affect the underlying pathophysiology...... of the disease and reduce as a secondary effect bone pain. Antiresorptive and anabolic agents, such as bisphosphonates and intermittent parathyroid hormone (1-34), respectively, have proven effective as pain relieving agents. Cathepsin K inhibitors and anti-sclerostin antibodies hold, due to their disease...... modifying effects, promise of a pain relieving effect. NSAIDs and opioids are widely employed in the treatment of bone pain. However, recent preclinical findings demonstrating a unique neuronal innervation of bone tissue and sprouting of sensory nerve fibers open for new treatment possibilities....

  13. Bone graft

    Science.gov (United States)

    ... around the area. The bone graft can be held in place with pins, plates, or screws. Why ... Orthopaedic Surgery, San Francosco, CA. Also reviewed by David Zieve, MD, MHA, Isla Ogilvie, PhD, and the ...

  14. SPECT imaging with the serotonin transporter radiotracer [{sup 123}I]p ZIENT in nonhuman primate brain

    Energy Technology Data Exchange (ETDEWEB)

    Cosgrove, Kelly P., E-mail: kelly.cosgrove@yale.ed [Yale University School of Medicine, VA Connecticut HCS (116A6), West Haven, CT 06516 (United States); Staley, Julie K.; Baldwin, Ronald M.; Bois, Frederic [Yale University School of Medicine, VA Connecticut HCS (116A6), West Haven, CT 06516 (United States); Plisson, Christophe [Emory University School of Medicine, Atlanta, GA 30322 (United States); Al-Tikriti, Mohammed S. [Yale University School of Medicine, VA Connecticut HCS (116A6), West Haven, CT 06516 (United States); Seibyl, John P. [Institute for Neurodegenerative Disorders, New Haven, CT 06510 (United States); Goodman, Mark M. [Emory University School of Medicine, Atlanta, GA 30322 (United States); Tamagnan, Gilles D. [Yale University School of Medicine, VA Connecticut HCS (116A6), West Haven, CT 06516 (United States); Institute for Neurodegenerative Disorders, New Haven, CT 06510 (United States)

    2010-07-15

    Introduction: Serotonin dysfunction has been linked to a variety of psychiatric diseases; however, an adequate SPECT radioligand to probe the serotonin transporter system has not been successfully developed. The purpose of this study was to characterize and determine the in vivo selectivity of iodine-123-labeled 2{beta}-carbomethoxy-3{beta}-(4'-((Z)-2-iodoethenyl)phenyl)nortropane, [{sup 123}I]p ZIENT, in nonhuman primate brain. Methods: Two ovariohysterectomized female baboons participated in nine studies (one bolus and eight bolus to constant infusion at a ratio of 9.0 h) to evaluate [{sup 123}I]p ZIENT. To evaluate the selectivity of [{sup 123}I]p ZIENT, the serotonin transporter blockers fenfluramine (1.5, 2.5 mg/kg) and citalopram (5 mg/kg), the dopamine transporter blocker methylphenidate (0.5 mg/kg) and the norepinephrine transporter blocker nisoxetine (1 mg/kg) were given at 8 h post-radiotracer injection. Results: In the bolus to constant infusion studies, equilibrium was established by 4-8 h. [{sup 123}I]p ZIENT was 93% and 90% protein bound in the two baboons and there was no detection of lipophilic radiolabeled metabolites entering the brain. In the high-density serotonin transporter regions (diencephalon and brainstem), fenfluramine and citalopram resulted in 35-71% and 129-151% displacement, respectively, whereas methylphenidate and nisoxetine did not produce significant changes (<10%). Conclusion: These findings suggest that [{sup 123}I]p ZIENT is a favorable compound for in vivo SPECT imaging of serotonin transporters with negligible binding to norepinephrine and dopamine transporters.

  15. [{sup 67}Ga]Gallium-complex with 2-acetylpyridine N4-ortho fluorophenylthiosemicarbazone as a radiotracer for brain tumor diagnosis

    Energy Technology Data Exchange (ETDEWEB)

    Pesquero, Jorge L. [Universidade Federal de Minas Gerais (UFMG), Belo Horizonte, MG (Brazil). Dept. de Fisiologia e Biofisica; Pujatti, Priscilla B.; Araujo, Elaine B. de [Instituto de Pesquisas Energeticas Nucleares (DIRF/IPEN/CNEN-SP), Sao Paulo, SP (Brazil). Diretoria de Radiofarmacia; Lessa, Josane A.; Beraldo, Heloisa [Universidade Federal de Minas Gerais (UFMG), Belo Horizonte, MG (Brazil). Dept. de Quimica; Soares, Marcella A.; Santos, Raquel G. dos, E-mail: santosr@cdtn.br [Centro de Desenvolvimento da Tecnologia Nuclear (CDTN/CNEN-MG), Belo Horizonte, MG (Brazil)

    2011-07-01

    The aim of this work was to develop a {sup 67}Ga-based SPECT imaging agent derived from 2-acetylpyridine N4-orthofluorophenyl - thiosemicarbazone (PhoF). For this purpose, PhoF was radiolabeled using {sup 67}Ga as radiotracer, and after quality control analysis its biodistribution and SPECT imaging were evaluated on Swiss mice and Nude mice bearing glioblastoma multiform tumor (U87-MG). The labelling of PhoF with {sup 67}GaCl{sub 3} was performed in methanol for 30 minutes at room temperature. Radiochemical analyses were done by HPLC with radioactivity detection. {sup 67}Ga- PhoF was successful produced with 97.5 {+-} 0.6% of radiochemical purity and high specific activity (1.0 TBq /mmol). {sup 67}Ga- PhoF showed to be a stable compound keeping its stability, when stored at 2-4 deg C. In biodistribution studies, {sup 67}Ga- PhoF displayed not only a significant tumor uptake, but also rapid blood clearance (T{sub 1/2} {sub fast} {sub phase}= 3.7 min. and T{sub 1/2} {sub slow} {sub phase}= 127.2 min.) and low accumulations in non target tissues, resulting in high target-to-non target ratios. Scintigraphic images of {sup 67}Ga- PhoF in nude mice bearing U87-MG tumor showed a significant activity in tumor ({approx} 7% of total activity) and tumor-to-normal tissue ratio was more than 10-fold higher depending on the organ. Our results suggest that {sup 67}Ga-PhoF possess indispensable characteristics for a good radiopharmaceutical for brain tumor diagnosis. (author)

  16. Metabolite identification of a radiotracer by electrochemistry coupled to liquid chromatography with mass spectrometric and radioactivity detection.

    Science.gov (United States)

    Baumann, Anne; Faust, Andreas; Law, Marylin P; Kuhlmann, Michael T; Kopka, Klaus; Schäfers, Michael; Karst, Uwe

    2011-07-01

    Radioligands, which specifically bind to a receptor or enzyme (target), enable molecular imaging of the target expression by positron emission tomography (PET). One very promising PET tracer is (S)-1-(4-(2-[(18)F]-fluoroethoxy)benzyl)-5-[1-(2-methoxymethylpyrrolidinyl)sulfonyl]isatin (isatin), a caspase-3 inhibitor, which has been developed at the University Hospital of Münster to image cell death (apoptosis). The translation of this novel tracer from preclinical evaluation to clinical examinations requires biodistribution studies, which characterize the pharmakodynamics and metabolic fate of the compound. This information is used to further optimize the radioligands and to interpret radioactive signals from tissues upon injection of the radioligand in vivo with respect to their specificity. The analysis of the metabolism of radioligands is hampered by the low amount of the compound being typically injected (nano/picomolar amount per injection). In the present study, electrochemistry (EC) is applied to elucidate the oxidative metabolism pathway of the radiotracer. Previous studies have demonstrated that EC can be utilized as a complementary tool to conventional in vitro approaches in drug metabolism studies. Thereby, potential oxidative metabolites of the isatin are determined by EC coupled to electrospray ionization mass spectrometry (EC/ESI-MS). Moreover, using EC/liquid chromatography (LC) and ESI-ion trap MS(n), structural elucidation of the oxidation products is performed. Comparatively to EC, in vitro metabolism studies with rat liver microsomes are conducted. Finally, the developed LC/ESI-MS method is applied to determine metabolites in body fluids and cell extracts from in vivo studies with the nonradioactive ((19)F) and radioactive isatin ((18)F). On the basis of the electrochemically generated oxidation products of the radioligand, the major radioactive metabolite occurring in vivo was successfully identified.

  17. Iodine-124 labelled Annexin-V as a potential radiotracer to study apoptosis using positron emission tomography

    Energy Technology Data Exchange (ETDEWEB)

    Glaser, Matthias E-mail: m.glaser@csc.mrc.ac.uk; Collingridge, D.R.; Aboagye, E.O.; Bouchier-Hayes, Lisa; Hutchinson, O. Clyde; Martin, S.J.; Price, Pat; Brady, Frank; Luthra, S.K

    2003-01-01

    Annexin-V is a calcium-dependent protein that binds with high affinity to phosphaditylserine exposed during apoptosis. The aim of this study was to radiolabel annexin-V with iodine-124 for use as a potential probe of apoptosis by positron emission tomography. Annexin-V was radioiodinated directly using the cyclotron-produced positron emitter iodine-124 by the chloramine-T (CAT) method and indirectly by the pre-labelled reagent N-succinimidyl 3-[{sup 124}I]iodobenzoate ([{sup 124}I]m-SIB). Some reaction parameters of the CAT method such as reaction time and pH were optimised to give radiochemical yields of 22.3{+-}2.6% (n=3, gel-filtration). After incubation with [{sup 124}I]m-SIB, radiolabelled annexin-V was obtained in 14% and 25% yield by FPLC and gel-filtration, respectively. The radiochemical purities from direct and indirect labelling were 97.7{+-}1.0% (n=3) and 96.7{+-}2.1% (n=3), respectively. The new radiotracers could be stored for up to four days without significant de-iodination. The biological activity of radiolabelled annexin-V was tested in control and camptothecin-treated (i.e. apoptotic) human leukaemic HL60 cells. A significantly higher (21%) binding in treated cells was observed with [{sup 125}I]m-SIB-annexin-V. The binding of [{sup 125}I]m-SIB labelled annexin-V to camptothecin treated cells was blocked (68%) by a 100-fold excess of unlabelled annexin-V. Abbreviations: Fast protein liquid chromatography (FPLC), Instant thin layer chromatography (ITLC), Sodium dodecylsulphate polyacrylamide gel electrophoresis (SDS-PAGE), 3-iodobenzoate (m-IBA), N-succinimidyl 3-(trimethylstannyl)benzoate (m-MeATE)

  18. 2'[(18)F]-fluoroethylrhodamine B is a promising radiotracer to measure P-glycoprotein function.

    Science.gov (United States)

    Trencsényi, György; Kertész, István; Krasznai, Zoárd T; Máté, Gábor; Szalóki, Gábor; Szabó Judit, P; Kárpáti, Levente; Krasznai, Zoltán; Márián, Teréz; Goda, Katalin

    2015-07-10

    In vivo detection of the emergence of P-glycoprotein (Pgp) mediated multidrug resistance in tumors could be beneficial for patients treated with anticancer drugs. PET technique in combination with appropriate radiotracers could be the most convenient method for detection of Pgp function. Rhodamine derivatives are validated fluorescent probes for measurement of mitochondrial membrane potential and also Pgp function. The aim of this study was to investigate whether 2'[(18)F]-fluoroethylrhodamine B ((18)FRB) a halogenated rhodamine derivative previously synthesized for PET assessment of myocardial perfusion preserved its Pgp substrate character. ATPase assay as well as accumulation experiments carried out using Pgp(+) and Pgp(-) human gynecologic (A2780/A2780(AD) and KB-3-1/KB-V1) and a mouse fibroblast cell pairs (NIH 3T3 and NIH 3T3 MDR1) were applied to study the interaction of (18)FRB with Pgp. ATPase assay proved that (18)FRB is a high affinity substrate of Pgp. Pgp(-) cells accumulated the (18)FRB rapidly in accordance with its lipophilic character. Dissipation of the mitochondrial proton gradient by a proton ionophore CCCP decreased the accumulation of rhodamine 123 (R123) and (18)FRB into Pgp(-) cells. Pgp(+) cells exhibited very low R123 and (18)FRB accumulation (around 1-8% of the Pgp(-) cell lines) which was not sensitive to the mitochondrial proton gradient; rather it was increased by the Pgp inhibitor cyclosporine A (CsA). Based on the above data we conclude that (18)FRB is a high affinity Pgp substrate and consequently a potential PET tracer to detect multidrug resistant tumors as well as the function of physiological barriers expressing Pgp.

  19. Synthesis and in vivo evaluation of novel radiotracers for the in vivo imaging of the norepinephrine transporter

    Energy Technology Data Exchange (ETDEWEB)

    Wilson, Alan A. E-mail: aaw@camhpet.on.ca; Patrick Johnson, David; Mozley, David; Hussey, Doug; Ginovart, Nathalie; Nobrega, Jose; Garcia, Armando; Meyer, Jeffery; Houle, Sylvain

    2003-02-01

    The (R,R) and (S,S) enantiomers of 2-[(2-methoxyphenoxy)phenylmethyl]morpholine (MeNER) have been radiolabelled with carbon-11 in good yield and at high specific activity. These radiotracers are close analogues of reboxetine, a potent and selective ligand for the norepinephrine transporter (NET). They were examined as potential ligands for imaging NET in vivo by positron emission tomography (PET). The in vivo brain distribution of both [{sup 11}C]-labeled enantiomers were evaluated in rats. Following tail-vein injection of the (R,R)-enantiomer regional brain uptake and washout of radioactivity was homogeneous at all time points examined (5-60 min). In contrast, administration of the (S,S)-enantiomer produced a heterogeneous distribution of radioactivity in brain with highest uptake in the hypothalamus, a NET rich region, and lowest uptake in the striatum, a brain region devoid of NET. Hypothalamus to striatum ratios of 2.5 to one were achieved at 60 min post injection of (S,S)-[{sup 11}C]-MeNER. Pre-injection of the norepinephrine reuptake inhibitors, reboxetine or desipramine, reduced hypothalamus to striatum ratios to near unity while reuptake inhibitors of dopamine and serotonin had no significant effect on binding. In vitro autoradiography studies (rat brain slices) with (S,S)-[{sup 11}C]-MeNER produced a regional distribution pattern that was consistent with the reported distribution of NET. (S,S)-[{sup 11}C]-MeNER has the potential to be the first successful PET ligand to image NET.

  20. Investigating the pharmacokinetics and biological distribution of silver-loaded polyphosphoester-based nanoparticles using (111) Ag as a radiotracer.

    Science.gov (United States)

    Aweda, Tolulope A; Zhang, Shiyi; Mupanomunda, Chiedza; Burkemper, Jennifer; Heo, Gyu Seong; Bandara, Nilantha; Lin, Mai; Cutler, Cathy S; Cannon, Carolyn L; Youngs, Wiley J; Wooley, Karen L; Lapi, Suzanne E

    2015-05-30

    Purified (111) Ag was used as a radiotracer to investigate silver loading and release, pharmacokinetics, and biodistribution of polyphosphoester-based degradable shell crosslinked knedel-like (SCK) nanoparticles as a comparison to the previously reported small molecule, N-heterocyclic silver carbene complex analog (SCC1) for the delivery of therapeutic silver ions in mouse models. Biodistribution studies were conducted by aerosol administration of (111) Ag acetate, [(111) Ag]SCC1, and [(111) Ag]SCK doses directly into the lungs of C57BL/6 mice. Nebulization of the (111) Ag antimicrobials resulted in an average uptake of 1.07 ± 0.12% of the total aerosolized dose given per mouse. The average dose taken into the lungs of mice was estimated to be 2.6 ± 0.3% of the dose inhaled per mouse for [(111) Ag]SCC1 and twice as much dose was observed for the [(111) Ag]SCKs (5.0 ± 0.3% and 5.9 ± 0.8% for [(111) Ag]aSCK and [(111) Ag]zSCK, respectively) at 1 h post administration (p.a.). [(111) Ag]SCKs also exhibited higher dose retention in the lungs; 62-68% for [(111) Ag]SCKs and 43% for [(111) Ag]SCC1 of the initial 1 h dose were observed in the lungs at 24 h p.a.. This study demonstrates the utility of (111) Ag as a useful tool for monitoring the pharmacokinetics of silver-loaded antimicrobials in vivo.

  1. A radiotracer method to study efflux transport of iodide liberated from thyroid hormones via deiodination metabolism in the brain.

    Science.gov (United States)

    Okamura, Toshimitsu; Igarashi, Jun; Kikuchi, Tatsuya; Fukushi, Kiyoshi; Arano, Yasushi; Irie, Toshiaki

    2009-06-05

    Thyroid hormones (TH) play an important role in the development and functional maintenance of the central nervous system. The purpose of this study was to develop a radiotracer method for studying the in vivo efflux transport of iodide liberated by the TH metabolism in the brain. The rationale of our method is as follows: a radioiodinated compound can enter the brain and rapidly release iodide in situ; the iodide efflux rate can be estimated from the clearance of brain radioactivity after disappearance of the iodinated compound. 6-[(125)I]Iodo-9-pentylpurine ([(125)I]9Pe6IP) was designed to enter the brain and release (125)I(-) by the reaction with glutathione and synthesized from the corresponding bromo derivative in a Br/(125)I exchange reaction. The brain kinetics of radioactivity and radioactive metabolites were investigated after intravenous injection of [(125)I]9Pe6IP into mice. The iodide efflux rate was estimated in mice pretreated with perchlorate, an inhibitor of iodide transport from the brain. High brain uptake (5.3% injected dose/g) was observed at 1 min, and almost complete conversion of [(125)I]9Pe6IP to (125)I(-) occurred 10 min after injection. The (125)I(-) uptake from the blood was negligible. (125)I(-) was eliminated from the brain along a single-exponential curve with a half-life of 6.0 min. Furthermore, dose-dependent inhibition of (125)I(-) efflux was observed in mice pretreated with perchlorate. We conclude that 9Pe6IP labeled with (124)I (positron emitter) or (123)I (single-photon emitter) may be useful for studying the in vivo efflux transport of iodide in the brain using nuclear medicine imaging devices.

  2. H-CRRETAWAC-OH, a Lead Structure for the Development of Radiotracer Targeting Integrin α5β1?

    Directory of Open Access Journals (Sweden)

    Roland Haubner

    2014-01-01

    Full Text Available Imaging of angiogenic processes is of great interest in preclinical research as well as in clinical settings. The most commonly addressed target structure for imaging angiogenesis is the integrin αvβ3. Here we describe the synthesis and evaluation of [18F]FProp-Cys*-Arg-Arg-Glu-Thr-Ala-Trp-Ala-Cys*-OH, a radiolabelled peptide designed to selectively target the integrin α5β1. Conjugation of 4-nitrophenyl-(RS-2-[18F]fluoropropionate provided [18F]FProp-Cys*-Arg-Arg-Glu-Thr-Ala-Trp-Ala-Cys*-OH in high radiochemical purity (>95% and a radiochemical yield of approx. 55%. In vitro evaluation showed α5β1 binding affinity in the nanomolar range, whereas affinity to αvβ3 and αIIbβ3 was >50 μM. Cell uptake studies using human melanoma M21 (αvβ3-positive and α5β1-negative, human melanoma M21-L (αvβ3-negative and α5β1-negative, and human prostate carcinoma DU145 (αvβ3-negative and α5β1-positive confirmed receptor-specific binding. The radiotracer was stable in human serum and showed low protein binding. Biodistribution studies showed tumour uptake ranging from 2.5 to 3.5% ID/g between 30 and 120 min post-injection. However, blocking studies and studies using mice bearing α5β1-negative M21 tumours did not confirm receptor-specific uptake of [18F]FProp-Cys*-Arg-Arg-Glu-Thr-Ala-Trp-Ala-Cys*-OH, although this radiopeptide revealed high affinity and substantial selectivity to α5β1 in vitro. Further experiments are needed to study the in vivo metabolism of this peptide and to develop improved radiopeptide candidates suitable for PET imaging of α5β1 expression in vivo.

  3. Low Bone Density

    Science.gov (United States)

    ... Information › Bone Density Exam/Testing › Low Bone Density Low Bone Density Low bone density is when your ... compared to people with normal bone density. Detecting Low Bone Density A bone density test will determine ...

  4. Low-Dose Adefovir-Induced Hypophosphatemic Osteomalacia on Whole-Body Bone Scintigraphy

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Sung Hoon; Won, Kyoung Sook; Song, Bongil; Jo, Il; Zeon, Seok Kil [Keimyung Univ., Daegu (Korea, Republic of)

    2013-12-15

    While adefovir dipivoxil (ADV) effectively suppresses the hepatitis B virus, it can cause proximal renal tubular dysfunction leading to phosphate wasting. The safety of low-dose ADV (a dose of 10 mg/day), which does not induce clinically significant nephrotoxicity, is well recognized, but a few cases of hypophosphatemic osteomalacia (HO) caused by low-dose ADV therapy have recently been reported. Although HO induced by low-dose ADV therapy is rare, the presence of bone pain in patients treated with ADV should be monitored. Bone scintigraphy can be performed to confirm the occurrence of osteomalacia and to determine the disease extent. Bone scintigraphic and radiological image findings with a brief review of the literature are presented in this article. We report two cases of HO induced by low-dose ADV therapy that showed multifocal increased radiotracer uptakes in the bilateral bony ribs, spines, pelvic bones and lower extremities on whole-body bone scintigraphy. Bone pain gradually improved after phosphate supplementation and by changing the antiviral agent. Whole-body bone scintigraphy is a highly sensitive imaging tool and can show disease extent at once in the setting of the wide range of the clinical spectrum with nonspecific radiological findings. Furthermore, frequent involvement of the lower extremities, as a result of maximum weight bearing, could be an additional scintigraphic clue for the diagnosis of HO. These cases could be helpful for both clinicians prescribing ADV and nuclear physicians to prevent delayed diagnosis and plan further appropriate treatment.

  5. Professional e-government seeking behavior

    DEFF Research Database (Denmark)

    Jonasen, Tanja Svarre; Lykke, Marianne

    2013-01-01

    behavior and if so how they change it. We focus on the status of current seeking behavior in a Danish government administration. The results showed that information needs are commonly verificative and consciously topical and that information seeking most often takes the form of mere “look-ups.” Employees......The present paper is concerned with professional e-government seeking behavior. With the digitalization of governments, expectations have been raised with regard to changes in the composition of employee work tasks. The purpose of our study is to determine whether these changes affect seeking...

  6. Bone marrow transplant

    Science.gov (United States)

    Transplant - bone marrow; Stem cell transplant; Hematopoietic stem cell transplant; Reduced intensity nonmyeloablative transplant; Mini transplant; Allogenic bone marrow transplant; Autologous bone marrow transplant; Umbilical ...

  7. Environmental biochemistry of current environmental levels of heavy metals: preparation of radiotracers with very high specific radioactivity for metallobiochemical experiments on laboratory animals.

    Science.gov (United States)

    Sabbioni, E; Goetz, L; Birattari, C; Bonardi, M

    1981-03-01

    Environmental toxicology research on dose-response relationships of heavy metals requires experiments on laboratory animals exposed to "low doses" of trace elements which should reflect "present or actual environmental levels" characteristic of polluted environments. Unfortunately no criteria exist to establish the "low doses" to which laboratory animals must be exposed, in practice the choice of the level used is made in an almost arbitrary manner. In order to define the "present environmental levels" of heavy metals which should be administered to laboratory animals an approach is suggested, based upon knowledge of the concentrations of trace elements in the diet, air and food as well as the fractions absorbed. Today daily intakes of trace elements by man are of the order of few micrograms or nanograms thus requiring the use of extremely sensitive analytical techniques to determine the very low amounts of heavy metals in tissues and cellular components. In these fields of research the use of radiotracers with very high specific radioactivity appears particularly advantageous but requires considerable care during their preparation and use. The first part of this paper deals with a definition of the ranges of concentrations of trace elements which should be used for metabolic studies on laboratory animals when they are exposed via different routes such as ingestion, inhalation in injection; the second part describes the production of radiotracers with very high specific radioactivity by proton activation in the cyclotron and by neutron irradiation in the nuclear reactor. Their use to label present levels of heavy metals under conditions adapted for biochemical purposes, as well as the preparation of different metal-labelled chemical species is also reported. Particular attention is directed to quality control of the radiotracer solutions which are administered to the animals including those of radioactivity concentrations, radioisotopic purity, radiochemical purity

  8. Separation of lanthanum, hafnium, barium and radiotracers yttrium-88 and barium-133 using crystalline zirconium phosphate and phosphonate compounds as prospective materials for a Ra-223 radioisotope generator

    Energy Technology Data Exchange (ETDEWEB)

    Moeller, Teresia [Lynntech Inc., 7610 Eastmark Dr, College Station, TX 77840 (United States); Bestaoui, Naima, E-mail: Naima.Bestaoui@Lynntech.co [Lynntech Inc., 7610 Eastmark Dr, College Station, TX 77840 (United States); Wierzbicki, Melissa; Adams, Todd; Clearfield, Abraham [Lynntech Inc., 7610 Eastmark Dr, College Station, TX 77840 (United States)

    2011-07-15

    Crystalline hybrid organic/inorganic ion exchangers based on zirconium phosphate and phosphonate compounds were evaluated for application in radium-223 generator for radiopharmaceutical applications. Various compositions were synthesized and the selectivity of these materials was determined for inactive lanthanum, hafnium and barium, and radiotracers yttrium-88 and barium-133. The hybrid materials show very efficient lanthanum/barium separation; the response for zirconium phosphate was even better. A small-scale column loaded with pelletized zirconium phosphate compound demonstrated excellent retention of {sup 88}Y and release of {sup 133}Ba.

  9. Dopamine D2 receptor radiotracers [{sup 11}C](+)-PHNO and [{sup 3}H]raclopride are indistinguishably inhibited by D2 agonists and antagonists ex vivo

    Energy Technology Data Exchange (ETDEWEB)

    McCormick, Patrick N. [Institute of Medical Science, University of Toronto, Toronto, Ontario, M5S 1A8 (Canada)], E-mail: patrick.mccormick@camhpet.ca; Kapur, Shitij [Department of Psychiatry, University of Toronto, Toronto, Ontario, M5S 1A8 (Canada); PET Center, Center for Addiction and Mental Health, Toronto, Ontario, M5T 1R8 (Canada); Seeman, Philip [Department of Psychiatry, University of Toronto, Toronto, Ontario, M5S 1A8 (Canada); Department of Pharmacology, University of Toronto, Toronto, Ontario, M5S 1A8 (Canada); Wilson, Alan A. [Department of Psychiatry, University of Toronto, Toronto, Ontario, M5S 1A8 (Canada); PET Center, Center for Addiction and Mental Health, Toronto, Ontario, M5T 1R8 (Canada)

    2008-01-15

    Introduction: In vitro, the dopamine D2 receptor exists in two states, with high and low affinity for agonists. The high-affinity state is the physiologically active state thought to be involved in dopaminergic illnesses such as schizophrenia. The positron emission tomography radiotracer [{sup 11}C](+)-PHNO ([{sup 11}C](+)-4-propyl-3,4,4a,5,6,10b-hexahydro-2H-naphtho[1,2-b][1,4] oxazin-9-o l), being a D2 agonist, should selectively label the high-affinity state at tracer dose and therefore be more susceptible to competition by agonist as compared to the antagonist [{sup 3}H]raclopride, which binds to both affinity states. Methods: We tested this prediction using ex vivo dual-radiotracer experiments in conscious rats. D2 antagonists (haloperidol or clozapine), a partial agonist (aripiprazole), a full agonist [(-)-NPA] or the dopamine-releasing drug amphetamine (AMPH) were administered to rats prior to an intravenous coinjection of [{sup 11}C](+)-PHNO and [{sup 3}H]raclopride. Rats were sacrificed 60 min after radiotracer injection. Striatum, cerebellum and plasma samples were counted for {sup 11}C and {sup 3}H. The specific binding ratio {l_brace}SBR, i.e., [%ID/g (striatum)-%ID/g (cerebellum)]/(%ID/g (cerebellum){r_brace} was used as the outcome measure. Results: In response to D2 antagonists, partial agonist or full agonist, [{sup 11}C](+)-PHNO and [{sup 3}H]raclopride SBRs responded indistinguishably in terms of both ED{sub 50} and Hill slope (e.g., (-)-NPA ED{sub 50} values are 0.027 and 0.023 mg/kg for [{sup 11}C](+)-PHNO and [{sup 3}H]raclopride, respectively). In response to AMPH challenge, [{sup 11}C](+)-PHNO and [{sup 3}H]raclopride SBRs were inhibited to the same degree. Conclusions: We have shown that the SBRs of [{sup 11}C](+)-PHNO- and [{sup 3}H]raclopride do not differ in their response to agonist challenge. These results do not support predictions of the in vivo binding behavior of a D2 agonist radiotracer and cast some doubt on the in vivo

  10. Bone development

    DEFF Research Database (Denmark)

    Tatara, M.R.; Tygesen, Malin Plumhoff; Sawa-Wojtanowicz, B.

    2007-01-01

    The objective of this study was to determine the long-term effect of alpha-ketoglutarate (AKG) administration during early neonatal life on skeletal development and function, with emphasis on bone exposed to regular stress and used to serve for systemic changes monitoring, the rib. Shropshire ram...... the groups were recorded int erms of: (1) growth rate, (2) body weight at days 14, 28 and 130 of age or (3) final body weight. The weight and length of ribs were, however, significantly increased in the lambs given AKG for the first 14 days of neonatal life by 8.2% and 3.2%, respectively (P....01). Furthermore, AKG administration induced significantly higher bone mineral density of the cortical bone by 7.1% (P

  11. [Bone transplant].

    Science.gov (United States)

    San Julián, M; Valentí, A

    2006-01-01

    We describe the methodology of the Bone and Soft Tissue Bank, from extraction and storage until use. Since the year 1986, with the creation of the Bone Bank in the University Clinic of Navarra, more than 3,000 grafts have been used for very different types of surgery. Bone grafts can be classified into cortical and spongy; the former are principally used in surgery to save tumour patients, in large post-traumatic reconstructions and in replacement surgery where there are massive bone defects and a structural support is required. The spongy grafts are the most used due to their numerous indications; they are especially useful in filling cavities that require a significant quantity of graft when the autograft is insufficient, or as a complement. They are also of special help in treating fractures when there is bone loss and in the treatment of delays in consolidation and pseudoarthrosis in little vascularized and atrophic zones. They are also used in prosthetic surgery against the presence of cavity type defects. Allografts of soft tissues are specially recognised in multiple ligament injuries that require reconstructions. Nowadays, the most utilised are those employed in surgery of the anterior cruciate ligament although they can be used for filling any ligament or tendon defect. The principal difficulties of the cortical allografts are in the consolidation of the ends with the bone itself and in tumour surgery, given that these are patients immunodepressed by the treatment, the incidence of infection is increased with respect to spongy grafts and soft tissues, which is irrelevant. In short, the increasingly widespread use of allografts is an essential therapeutic weapon in orthopaedic surgery and traumatology. It must be used by expert hands.

  12. Bone mineral content and bone metabolism in young adults with severe periodontitis

    DEFF Research Database (Denmark)

    Wowern von, N.; Westergaard, J.; Kollerup, G.

    2001-01-01

    Bone loss, bone markers, bone metabolism, bone mineral content, osteoporosis, severe periodontitis......Bone loss, bone markers, bone metabolism, bone mineral content, osteoporosis, severe periodontitis...

  13. [{sup 11}C]d-threo-Methylphenidate, a new radiotracer for the dopamine transporter. Characterization in baboon and human brain

    Energy Technology Data Exchange (ETDEWEB)

    Ding, Y.S.; Volkow, N.D.; Fowler, J.S. [Brookhaven National Laboratory, Upton, NY (United States)] [and others

    1995-05-01

    dl-threo Methylphenidate (MP, Ritalin) is a psychostimulant drug which binds to the dopamine transporter (DAT). We evaluated [{sup 11}C]d-threo-methylphenidate ([{sup 11}C]d-MP), the more active enantiomer, as a radiotracer for the DAT in baboons and human brain. Stereoselectivity, saturability and pharmacological specificity and reproducibility were examined. Stereoselectivity was examined in baboons by comparing [{sup 11C}]d-MP,[{sup 11}C]l-MP and [{sup 11}C]dl-MP. Unlabeled MP was used to assess the reversibility and saturability of the binding. GBR 12909,{beta}-(4-iodophenyl)tropane-2-carboxylic acid methyl ester ({beta}-CIT), tomoxetine and citalopram were used to assess the specificity of the binding. The ratios between the radioactivity in the striatum to that in cerebellum (ST/CB) were 3.3,2.2 and 1.1 for [{sup 11}C]d-MP,[{sup 11}C]dl-MP and [{sup 11}C]l-MP respectively. Most of the striatal binding of [{sup 11}C]d-threo-MP was displaced by injection of nonradioactive MP demonstrating reversibility. Pretreatment with MP (0.5 mg/kg), GBR12909 (1.5 mg/kg) or {beta}-CIT (0.3 mg/kg) reduced ST/CB by about 60% and the ratios of distribution volumes at the steady-state for the triatum to cerebellum (DV{sub st/}DV{sub cb}) by about 50%. Pretreatment with tomoxetine (3.0 mg/kg) or citalopram (2.0 mg/kg), inhibitors of the norepinephrine and serotonin transporter, had no effect. Studies of [{sup 11}C]d-MP in the human brain showed highest uptake in basal ganglia with a half clearance time of about 60 minutes. Repeated studies in 6 normal human subjects showed differences in DV{sub st/}DV{sub cb} between -7% and 8%. MP pretreatment decreased BG but no cortical or cerebellar binding and reduced Bmax/Kd by 91%.

  14. Radiosynthesis and biodistribution of {sup 99m}Tc-rifampicin: A novel radiotracer for in-vivo infection imaging

    Energy Technology Data Exchange (ETDEWEB)

    Shah, Syed Qaiser, E-mail: ssqaiser2002@yahoo.co [Nuclear Medicine Research Laboratory (NMRL), University of Peshawar, Room no 111, Academic Block I, Peshawar, NWFP (Pakistan); Khan, Aakif Ullah [Nuclear Medicine, Oncology and Radiotherapy Institute (NORI), Islamabad (Pakistan); Khan, Muhammad Rafiullah [Phyotopharmaceutical and Neutraceuticals Research Laboratory (PNRL), University of Peshawar, Peshawar, NWFP (Pakistan)

    2010-12-15

    {sup 99m}Tc-rifampicin ({sup 99m}Tc-RMP) a new radioantibiotic complex was synthesized specifically for the infection localization caused by methicillin-resistant Staphylococcus aureus (MRSA). The in-vitro radiochemical purity (RCP) yield, in-vivo biodistribution behavior in artificially infected rats (AIT) and scintigraphic accuracy in artificially infected rabbit (AIB) of the {sup 99m}Tc-RMP complex was investigated using different concentration of the RMP, sodium pertechnetate (Na{sup 99m}TcO{sub 4}), stannous chloride dihydrate (SnCl{sub 2}.2H{sub 2}O) at different pH ranges 5-6. The best RCP yield observed at 30, 60, 90 and 120 min after labeling was; 98.95{+-}0.20, 98.15{+-}0.24, 96.50{+-}0.27 and 91.55{+-}0.22%, respectively, using 1.5 mg RMP, 175 {mu}L of SnCl{sub 2}.2H{sub 2}O (1 {mu}g/{mu}L in 0.01 N HCl), 3 mCi of Na{sup 99m}TcO{sub 4}, at pH 5.6. Initially in the infected muscle (INM) of the AIT the activity was lower but after 90 min it went up to 18.35{+-}0.20% from 5.95{+-}0.25%. The activity in the inflamed muscle (IMM), normal (NM) muscle, blood, liver and spleen was initially high that decreased with time. The ratios of the INM/NM and IMM/NM were 7.34{+-}0.74 and 1.20{+-}0.85, respectively. The whole body static (WBS) imaging of the MRSA infected rabbit confirmed the usefulness of the {sup 99m}Tc-RMP as a precise radiotracer for MRSA infection imaging. On the basis of in-vitro RCP, in-vivo biodistribution and scintigraphic precision, we recommend the {sup 99m}Tc-RMP complex prepared aseptically for in-vivo assessment of MRSA infection.

  15. Exploring Older Adults' Health Information Seeking Behaviors

    Science.gov (United States)

    Manafo, Elizabeth; Wong, Sharon

    2012-01-01

    Objective: To explore older adults' (55-70 years) health information-seeking behaviors. Methods: Using a qualitative methodology, based on grounded theory, data were collected using in-depth interviews. Participants were community-living, older adults in Toronto, Canada who independently seek nutrition and health information. Interview transcripts…

  16. Design of Interfaces for Information Seeking.

    Science.gov (United States)

    Marchionini, Gary; Komlodi, Anita

    1998-01-01

    Examines the current state of user interface design for information seeking. Topics include technology push and interdisciplinarity; research and development; literature trends; user-centered interface design; information seeking in electronic environments; online information retrieval system interfaces; online public access catalog interfaces;…

  17. Exploring Older Adults' Health Information Seeking Behaviors

    Science.gov (United States)

    Manafo, Elizabeth; Wong, Sharon

    2012-01-01

    Objective: To explore older adults' (55-70 years) health information-seeking behaviors. Methods: Using a qualitative methodology, based on grounded theory, data were collected using in-depth interviews. Participants were community-living, older adults in Toronto, Canada who independently seek nutrition and health information. Interview transcripts…

  18. Information-Seeking Habits of Education Faculty

    Science.gov (United States)

    Rupp-Serrano, Karen; Robbins, Sarah

    2013-01-01

    This study explores the information-seeking behavior of academic education faculty from twenty large public research universities. The investigation includes an examination of how frequently education faculty seek or access information, how they stay up-to-date on current developments in the field and identify less recent journal literature, how…

  19. Professional e-government seeking behavior

    DEFF Research Database (Denmark)

    Jonasen, Tanja Svarre; Lykke, Marianne

    2013-01-01

    The present paper is concerned with professional e-government seeking behavior. With the digitalization of governments, expectations have been raised with regard to changes in the composition of employee work tasks. The purpose of our study is to determine whether these changes affect seeking...

  20. PRISM: a planned risk information seeking model.

    Science.gov (United States)

    Kahlor, LeeAnn

    2010-06-01

    Recent attention on health-related information seeking has focused primarily on information seeking within specific health and health risk contexts. This study attempts to shift some of that focus to individual-level variables that may impact health risk information seeking across contexts. To locate these variables, the researcher posits an integrated model, the Planned Risk Information Seeking Model (PRISM). The model, which treats risk information seeking as a deliberate (planned) behavior, maps variables found in the Theory of Planned Behavior (TPB; Ajzen, 1991) and the Risk Information Seeking and Processing Model (RISP; Griffin, Dunwoody, & Neuwirth, 1999), and posits linkages among those variables. This effort is further informed by Kahlor's (2007) Augmented RISP, the Theory of Motivated Information Management (Afifi & Weiner, 2004), the Comprehensive Model of Information Seeking (Johnson & Meischke, 1993), the Health Information Acquisition Model (Freimuth, Stein, & Kean, 1989), and the Extended Parallel Processing Model (Witte, 1998). The resulting integrated model accounted for 59% of the variance in health risk information-seeking intent and performed better than the TPB or the RISP alone.

  1. Information-Seeking Habits of Education Faculty

    Science.gov (United States)

    Rupp-Serrano, Karen; Robbins, Sarah

    2013-01-01

    This study explores the information-seeking behavior of academic education faculty from twenty large public research universities. The investigation includes an examination of how frequently education faculty seek or access information, how they stay up-to-date on current developments in the field and identify less recent journal literature, how…

  2. Bone lesion biopsy

    Science.gov (United States)

    Bone biopsy; Biopsy - bone ... needle is gently pushed and twisted into the bone. Once the sample is obtained, the needle is ... sample is sent to a lab for examination. Bone biopsy may also be done under general anesthesia ...

  3. Facts about Broken Bones

    Science.gov (United States)

    ... Room? What Happens in the Operating Room? Broken Bones KidsHealth > For Kids > Broken Bones Print A A ... sticking through the skin . What Happens When a Bone Breaks? It hurts to break a bone! It's ...

  4. Calcium and bones

    Science.gov (United States)

    Bone strength and calcium ... calcium (as well as phosphorus) to make healthy bones. Bones are the main storage site of calcium in ... your body does not absorb enough calcium, your bones can get weak or will not grow properly. ...

  5. Broken Bones (For Parents)

    Science.gov (United States)

    ... Feeding Your 1- to 2-Year-Old Broken Bones KidsHealth > For Parents > Broken Bones Print A A ... bone fragments in place. When Will a Broken Bone Heal? Fractures heal at different rates, depending upon ...

  6. Bone biopsy (image)

    Science.gov (United States)

    A bone biopsy is performed by making a small incision into the skin. A biopsy needle retrieves a sample of bone and it ... examination. The most common reasons for bone lesion biopsy are to distinguish between benign and malignant bone ...

  7. Bone densitometry

    DEFF Research Database (Denmark)

    Ravn, Pernille; Alexandersen, P; Møllgaard, A

    1999-01-01

    The bisphosphonates have been introduced as alternatives to hormone replacement therapy (HRT) for the treatment and prevention of postmenopausal osteoporosis. The expected increasing application in at clinical practice demands cost-effective and easily handled methods to monitor the effect on bone...

  8. Osteoclasts prefer aged bone

    DEFF Research Database (Denmark)

    Henriksen, K; Leeming, Diana Julie; Byrjalsen, I

    2007-01-01

    We investigated whether the age of the bones endogenously exerts control over the bone resorption ability of the osteoclasts, and found that osteoclasts preferentially develop and resorb bone on aged bone. These findings indicate that the bone matrix itself plays a role in targeted remodeling...... of aged bones....

  9. Design, synthesis and evaluation of [(3)H]PF-7191, a highly specific nociceptin opioid peptide (NOP) receptor radiotracer for in vivo receptor occupancy (RO) studies.

    Science.gov (United States)

    Zhang, Lei; Drummond, Elena; Brodney, Michael A; Cianfrogna, Julie; Drozda, Susan E; Grimwood, Sarah; Vanase-Frawley, Michelle A; Villalobos, Anabella

    2014-11-15

    Herein we report the identification of (+)-N-(2-((1H-pyrazol-1-yl)methyl)-3-((1R,3r,5S)-6'-fluoro-8-azaspiro[bicyclo[3.2.1]octane-3,1'-isochroman]-8-yl)propyl)-N-[(3)H]-methylacetamide {[(3)H]PF-7191 [(+)-11]} as a promising radiotracer for the nociceptin opioid peptide (NOP) receptor. (+)-11 demonstrated high NOP binding affinity (Ki = 0.1 nM), excellent selectivity over other opioid receptors (>1000×) and good brain permeability in rats (C(b,u)/C(p,u) = 0.29). Subsequent characterization of [(3)H](+)-11 showed a high level of specific binding and a brain bio-distribution pattern consistent with known NOP receptor expression. Furthermore, the in vivo brain binding of [(3)H](+)-11 in rats was inhibited by a selective NOP receptor antagonist in a dose-responsive manner. This overall favorable profile indicated that [(3)H](+)-11 is a robust radiotracer for pre-clinical in vivo receptor occupancy (RO) measurements and a possible substrate for carbon-11 labeling for positron emission tomography (PET) imaging in higher species. Copyright © 2014 Elsevier Ltd. All rights reserved.

  10. Determination of the particle size distribution in a powder using radiotracers; Determinacion de la distribucion de tamano de particulas en un polvo utilizando radiotrazadores

    Energy Technology Data Exchange (ETDEWEB)

    Revilla D, R

    1974-07-01

    To determine experimentally the particle size distribution in a powder the meshed method is generally used. This method has the disadvantage that in the obtained distribution is not observed at detail the fine structure of such distribution. In this work, a method for obtaining the distribution of particle size using radiotracers is presented. In the obtained distribution by this method it is observed with more detail the fine structure of the distribution, comparing with the obtained results by the classical method of meshed. The radiotracer method has major resolution for the experimental determination mentioned. In the chapter 1, it is done a brief analysis about theoretical aspects related with the method. In the first part it is analysed the particle behavior (sedimenting) in a fluid. The second part treats the relating with the radioactivity of an activated material as well as its detection. In the chapter 2, a description of the method is done also the experimental problems to applying to the alumina crystals sample are discussed. In the chapter 3 the obtained results and the mistake calculations in such results are showed. Finally, in the chapter 4 the conclusions and recommendations are given which is possible to obtain better results and improve to those in this work were obtained. (Author)

  11. Assessment of Bone Metastases in Patients with Prostate Cancer—A Comparison between 99mTc-Bone-Scintigraphy and [68Ga]Ga-PSMA PET/CT

    Directory of Open Access Journals (Sweden)

    Lena Thomas

    2017-07-01

    Full Text Available Purpose: Bone scintigraphy is the standard of reference in bone metastases in prostate cancer patients. However, new radiotracers employed in prostate-specific membrane antigen (PSMA-ligands has led to the growing importance of PET/CT as diagnostic tool. The aim of our study was to investigate the difference between bone scan and PSMA-PET/CT for the detection of bone metastases in prostate cancer. Methods: Thirty patients with bone metastases originating from prostate cancer were examined by 99mTc-MDP bone scan and 68Ga-PSMA-PET/CT within an average of 21 days. Bone scans were analyzed visually according to the number of lesions and using the software package ExiniBONE by Exini Diagnostics. PET/CT data was analyzed visually. Numbers of detected lesions were compared for the different methods for the whole patient and for different regions. In addition, results were compared to serum prostate-specific antigen (PSA, alkaline phosphatase (ALP, bone alkaline phosphatase (bALP, pro gastrin releasing peptide (pGRP and eastern cooperative oncology group (ECOG performance status. Results: In the bone scans, visual and semiautomatic lesion detection showed similar results with an average of 19.4 and 17.8 detected bone lesion per patient. However, in PSMA-PET/CT, on average double the numbers of lesions (40.0 were detected. The largest differences were found in the thorax and pelvis, which can be explained by the advantages of tomographic imaging. Bland-Altman analysis showed greater differences in patients with large numbers of bone metastases. Conclusion: No significant difference was found when using semiautomatic analysis compared to visual reading for bone scans. Fewer bone metastases were detected in bone scans than in PSMA-PET/CT. However, in none of our patients would the difference have led to clinical consequences. Therefore, it seems that for patients undergoing PSMA-PET/CT, there is no need to perform additional bone scans if the appropriate

  12. Automated segmentation of tumors on bone scans using anatomy-specific thresholding

    Science.gov (United States)

    Chu, Gregory H.; Lo, Pechin; Kim, Hyun J.; Lu, Peiyun; Ramakrishna, Bharath; Gjertson, David; Poon, Cheryce; Auerbach, Martin; Goldin, Jonathan; Brown, Matthew S.

    2012-03-01

    Quantification of overall tumor area on bone scans may be a potential biomarker for treatment response assessment and has, to date, not been investigated. Segmentation of bone metastases on bone scans is a fundamental step for this response marker. In this paper, we propose a fully automated computerized method for the segmentation of bone metastases on bone scans, taking into account characteristics of different anatomic regions. A scan is first segmented into anatomic regions via an atlas-based segmentation procedure, which involves non-rigidly registering a labeled atlas scan to the patient scan. Next, an intensity normalization method is applied to account for varying levels of radiotracer dosing levels and scan timing. Lastly, lesions are segmented via anatomic regionspecific intensity thresholding. Thresholds are chosen by receiver operating characteristic (ROC) curve analysis against manual contouring by board certified nuclear medicine physicians. A leave-one-out cross validation of our method on a set of 39 bone scans with metastases marked by 2 board-certified nuclear medicine physicians yielded a median sensitivity of 95.5%, and specificity of 93.9%. Our method was compared with a global intensity thresholding method. The results show a comparable sensitivity and significantly improved overall specificity, with a p-value of 0.0069.

  13. An adaptation model for trabecular bone at different mechanical levels

    Directory of Open Access Journals (Sweden)

    Lv Linwei

    2010-07-01

    Full Text Available Abstract Background Bone has the ability to adapt to mechanical usage or other biophysical stimuli in terms of its mass and architecture, indicating that a certain mechanism exists for monitoring mechanical usage and controlling the bone's adaptation behaviors. There are four zones describing different bone adaptation behaviors: the disuse, adaptation, overload, and pathologic overload zones. In different zones, the changes of bone mass, as calculated by the difference between the amount of bone formed and what is resorbed, should be different. Methods An adaptation model for the trabecular bone at different mechanical levels was presented in this study based on a number of experimental observations and numerical algorithms in the literature. In the proposed model, the amount of bone formation and the probability of bone remodeling activation were proposed in accordance with the mechanical levels. Seven numerical simulation cases under different mechanical conditions were analyzed as examples by incorporating the adaptation model presented in this paper with the finite element method. Results The proposed bone adaptation model describes the well-known bone adaptation behaviors in different zones. The bone mass and architecture of the bone tissue within the adaptation zone almost remained unchanged. Although the probability of osteoclastic activation is enhanced in the overload zone, the potential of osteoblasts to form bones compensate for the osteoclastic resorption, eventually strengthening the bones. In the disuse zone, the disuse-mode remodeling removes bone tissue in disuse zone. Conclusions The study seeks to provide better understanding of the relationships between bone morphology and the mechanical, as well as biological environments. Furthermore, this paper provides a computational model and methodology for the numerical simulation of changes of bone structural morphology that are caused by changes of mechanical and biological

  14. Whole Body Bone Scan Findings after High Intensity Focused Ultrasound (HIFU) Treatment

    Energy Technology Data Exchange (ETDEWEB)

    Seo, Ye Young; O, Joo Hyun; Sohn, Hyung Sun; Choi, Eun Kyoung; Yoo, Ik Dong; Oh, Jin Kyoung; Han, Eun Ji; Jung, Seung Eun; Kim, Sung Hoon [The Catholic Univ. of Korea, Seoul (Korea, Republic of)

    2011-12-15

    This study aims to examine the findings of {sup 99mT}c diphosphonate bone scans in cancer patients with a history of HIFU treatment. Bone scan images of patients with a history of HIFU treatment for primary of metastatic cancer from January 2006 to July 2010 were retrospectively reviewed. Cases of primary bone tumor or HIFU treatment reaching only the superficial soft tissue layer were excluded. Bone scan images of 62 patients (26 female, 36 male; mean age 57{+-}9 years) were studied. HIFU treatment was performed in the liver (n=40), pancreas (n=40), pancreas (n=16), and breast (n=6). Mean interval time between HIFU treatment and bone scan was 106{+-}105 days (range: 1-572 days). Of 62 scans, 43 showed diffusely decreased uptake of bone within the path of HIFU treatment: antero axillary and/or posterior arcs of right 5th to 11th ribs in 34 cases after treatment of hepatic lesions; anterior arcs of 2nd to 5th ribs in 5 cases after treatment for breast tumors; and posterior arcs of left 9th to 11th ribs or thoraco lumbar vertebrae in 4 cases after treatment for pancreas tumor. Of 20 patients who had bone scans more than twice, five showed recovered uptake of the radiotracer in the involved ribs in the follow up bone scan. Of 62 bone scans in patients with a history of HIFU treatment for primary of metastatic cancer, 69% presented diffusely decreased uptake in the bone in the path of HIFU treatment.

  15. PID Tuning Using Extremum Seeking

    Energy Technology Data Exchange (ETDEWEB)

    Killingsworth, N; Krstic, M

    2005-11-15

    ]. This method is based on the performance of the closed-loop system during a step response experiment [10], [11]. In this article we present a method for optimizing the step response of a closed-loop system consisting of a PID controller and an unknown plant with a discrete version of extremum seeking (ES). Specifically, ES is used to minimize a cost function similar to that used in [10], [11], which quantifies the performance of the PID controller. ES, a non-model-based method, iteratively modifies the arguments (in this application the PID parameters) of a cost function so that the output of the cost function reaches a local minimum or local maximum. In the next section we apply ES to PID controller tuning. We illustrate this technique through simulations comparing the effectiveness of ES to other PID tuning methods. Next, we address the importance of the choice of cost function and consider the effect of controller saturation. Furthermore, we discuss the choice of ES tuning parameters. Finally, we offer some conclusions.

  16. Stochastic Control Model on Rent Seeking

    Institute of Scientific and Technical Information of China (English)

    2008-01-01

    A continuous-time stochastic model is constructed to analyze how to control rent seeking behaviors. Using the stochastic optimization methods based on the modern risky theory, a unique positive solution to the dynamic model is derived. The effects of preference-related parameters on the optimal control level of rent seeking are discussed, and some policy measures are given. The results show that there exists a unique solution to the stochastic dynamic model under some macroeconomic assumptions, and that raising public expenditure may have reverse effects on rent seeking in an underdeveloped or developed economic environment.

  17. Differences in Bone Quality between High versus Low Turnover Renal Osteodystrophy

    Energy Technology Data Exchange (ETDEWEB)

    Porter, Daniel S. [University of Kentucky, Lexington; Pienkowski, David [University of Kentucky, Lexington; Faugere, Marie-Claude [Albert B. Chandler Medical Center; Malluche, Hartmut H. [Albert B. Chandler Medical Center

    2012-01-01

    Abnormal bone turnover is common in chronic kidney disease (CKD), but its effects on bone quality remain unclear. This study sought to quantify the relationship between abnormal bone turnover and bone quality. Iliac crest bone biopsies were obtained from CKD-5 patients on dialysis with low (n=18) or high (n=17) turnover, and from volunteers (n=12) with normal turnover and normal kidney function. Histomorphometric methods were used to quantify the microstructural parameters; Fourier transform infrared spectroscopy and nanoindentation were used to quantify the material and mechanical properties in bone. Reduced mineral-to-matrix ratio, mineral crystal size, stiffness and hardness were observed in bone with high turnover compared to bone with normal or low turnover. Decreased cancellous bone volume and trabecular thickness were seen in bone with low turnover compared to bone with normal or high turnover. Bone quality, as defined by its microstructural, material, and mechanical properties, is related to bone turnover. These data suggest that turnover related alterations in bone quality may contribute to the known diminished mechanical competence of bone in CKD patients, albeit from different mechanisms for bone with high (material abnormality) vs. low (microstructural alteration) turnover. The present findings suggest that improved treatments for renal osteodystrophy should seek to avoid low or high bone turnover and aim for turnover rates as close to normal as possible.

  18. Sexual information seeking on web search engines.

    Science.gov (United States)

    Spink, Amanda; Koricich, Andrew; Jansen, B J; Cole, Charles

    2004-02-01

    Sexual information seeking is an important element within human information behavior. Seeking sexually related information on the Internet takes many forms and channels, including chat rooms discussions, accessing Websites or searching Web search engines for sexual materials. The study of sexual Web queries provides insight into sexually-related information-seeking behavior, of value to Web users and providers alike. We qualitatively analyzed queries from logs of 1,025,910 Alta Vista and AlltheWeb.com Web user queries from 2001. We compared the differences in sexually-related Web searching between Alta Vista and AlltheWeb.com users. Differences were found in session duration, query outcomes, and search term choices. Implications of the findings for sexual information seeking are discussed.

  19. INFORMATION SEEKING BEHAVIOUR OF PREGNANT WOMEN IN ...

    African Journals Online (AJOL)

    Challenges facing information seeking were attributed mainly to ... India, being a developing country, contributes ... required by rural women. 79 ... identified family and friends, local herb hawkers, local drug sellers (hawkers) .... Lack of Radio.

  20. Vocational Information-Seeking Behavior: Another View.

    Science.gov (United States)

    Sharf, Richard S.

    1984-01-01

    Used an unobtrusive measure to examine vocational information-seeking behavior (VISB) patterns in three groups of noncollege-bound youths (N=95). Results showed no meaningful relationship between VISB and certainty of choice or Holland type. (JAC)

  1. Social Work with unaccompanied aylum seeking children

    DEFF Research Database (Denmark)

    Jensen, Niels Rosendal

    2010-01-01

    Review of "textbook" on social work with unaccompanied asyum seeking children. This book presents national and international research findings, case stories and interviews, is written on a high level and deserves a braod audience......Review of "textbook" on social work with unaccompanied asyum seeking children. This book presents national and international research findings, case stories and interviews, is written on a high level and deserves a braod audience...

  2. Rent seeking and the economics of corruption

    OpenAIRE

    Aidt, T.S.

    2016-01-01

    The paper studies the influence of Gordon Tullock (1967) and the rent-seeking literature more generally on the study of corruption. The theoretical corruption literature with its emphasis on principal-agent relationships within government and rent creation by corruption politicians has largely, but not entirely, overlooked that contestable rents encourage unproductive use of real resources in seeking these rents. As a consequence, the literature underestimates the value of corruption control ...

  3. Horizontal alveolar bone loss: A periodontal orphan

    Directory of Open Access Journals (Sweden)

    Jayakumar A

    2010-01-01

    Full Text Available Background: Attempts to successfully regenerate lost alveolar bone have always been a clinician′s dream. Angular defects, at least, have a fairer chance, but the same cannot be said about horizontal bone loss. The purpose of the present study was to evaluate the prevalence of horizontal alveolar bone loss and vertical bone defects in periodontal patients; and later, to correlate it with the treatment modalities available in the literature for horizontal and vertical bone defects. Materials and Methods: The study was conducted in two parts. Part I was the radiographic evaluation of 150 orthopantomographs (OPGs (of patients diagnosed with chronic periodontitis and seeking periodontal care, which were digitized and read using the AutoCAD 2006 software. All the periodontitis-affected teeth were categorized as teeth with vertical defects (if the defect angle was ≤45° and defect depth was ≥3 mm or as having horizontal bone loss. Part II of the study comprised search of the literature on treatment modalities for horizontal and vertical bone loss in four selected periodontal journals. Results: Out of the 150 OPGs studied, 54 (36% OPGs showed one or more vertical defects. Totally, 3,371 teeth were studied, out of which horizontal bone loss was found in 3,107 (92.2% teeth, and vertical defects were found only in 264 (7.8% of the teeth, which was statistically significant (P<.001. Search of the selected journals revealed 477 papers have addressed the treatment modalities for vertical and horizontal types of bone loss specifically. Out of the 477 papers, 461 (96.3% have addressed vertical bone loss, and 18 (3.7% have addressed treatment options for horizontal bone loss. Two papers have addressed both types of bone loss and are included in both categories. Conclusion: Horizontal bone loss is more prevalent than vertical bone loss but has been sidelined by researchers as very few papers have been published on the subject of regenerative treatment

  4. Intention to seek information on cancer genetics

    Directory of Open Access Journals (Sweden)

    J.E. Andrews

    2005-01-01

    Full Text Available Objective. The public has a high interest in seeking personal genetic information, which holds implications for health information seeking research and health care policy. Rapid advances in cancer genetics research promise early detection, prevention and treatment, yet consumers may have greater difficulty finding and using the information they may need to make informed decisions regarding their personal health and the future of their families. Design. A statewide telephone survey was conducted of non-institutionalized Kentucky residents 18 years of age or older to investigate factors associated with the intention to seek cancer genetics information, including the need for such information seeking help. Results. The results show that intention to seek cancer genetics information, if testing were readily available, is moderately high (62.5% of those responding; n=835, and that status as a racial minority, the perception that cancer runs in one's family, and frequent worrying about cancer risk are statistically significant predictors of intent to seek genetics information. Conclusion. . We argue that an already complex health information environment will be even more difficult for individuals to navigate as genetic research becomes more ubiquitous in health care. An increase in demand for genetics information in various forms, as suggested by these results and those of other studies, implies that enduring intervention strategies are needed to help individuals acquire necessary health information literacy skills, with special attention given to racial minorities.

  5. Model studies using supercritical carbon dioxide fluid (SF CO{sub 2}) as a reaction medium for radiotracer synthesis and purification

    Energy Technology Data Exchange (ETDEWEB)

    Ferrieri, R.A.; Fowler, J.S.; Wolf, A.P. [Brookhaven National Lab., Upton, NY (United States)

    1994-05-01

    Supercritical fluids (SFs) have found widespread use in the analytical field as solvents for compound purification, and initial results on their use for radiotracer synthesis have been reported. SF`s possess the unique feature that their solvating strength can be altered drastically through small changes in pressure and temperature of the fluid within the supercritical regime. We have modified a SF chromatograph to allow us to investigate its use in radiotracer synthesis and purification. The solubility of several PET radiotracers was measured in SF CO{sub 2} at 5000 psi and 55{degrees}C and showed the following: raclopride, 68 {mu}g/mL{sup 2}; (L)-deprenyl, 85 {mu}g/mL; flumazenil, 61 {mu}g/mL; (-)cocaine, 108 {mu}g/mL; ritalin, 45 {mu}g/Ml; and cogentin, 250 {mu}g/mL. Analytical separations were achieved on 30 to 50 {mu}g amounts of (L)-deprenyl (3.9 min RT) and nor-deprenyl (4.7 min RT), as well as raclopride (10.8 min RT) and nor-raclopride (10.3 min RT) using 250 mm x 4.5 mm i.d. Ultracarb 5 ODS (30), and 75 mm x 4.5 mm i.d. silica columns, respectively, and pure SF CO{sub 2} as the mobile phase. Model studies on simple N-alkylation reactions were also carried out using pur SF CO{sub 2} as the reaction medium on a modified alumina support. (L)-Deprenyl was synthesized from only 100 {mu}g of the starting labelling substrate using 500 mg of alumina impregnated with triphenylphosphine diiodide (20% by wt.) and maintained at 170{degrees}C. The methylating agent, methyl iodide, was generated in situ from methanol, but was always present in excess of the substrate. Studies are in progress to reduce methanol amounts. Pressure studies of SF CO{sub 2} ranging from 3000 to 6000 psi showed an 80% increase in the methylation reaction relative to the amount of starting substrate suggesting an effect of the fluid density. Temperature was also a critical parameter here as the reaction did not proceed at 80{degrees}C for similiar pressures.

  6. Evaluation of [18F]MC225 as a PET radiotracer for measuring P-glycoprotein function at the blood-brain barrier in rats: Kinetics, metabolism, and selectivity.

    NARCIS (Netherlands)

    Savolainen, Heli; Windhorst, Albert D.; Elsinga, Philip H.; Cantore, Mariangela; Colabufo, Nicola A.; Willemsen, Antoon T.M.; Luurtsema, Geert

    2016-01-01

    P-glycoprotein is a protective efflux transporter at the blood-brain barrier showing altered function in many neurological disorders. The purpose of this study was to validate [18F]MC225 as a radiotracer for measuring P-glycoprotein function with positron emission tomography. Three groups of Sprague

  7. Bovine Calcined Bone for the Repair of Radial Defect in a Rabbit Model

    Institute of Scientific and Technical Information of China (English)

    2000-01-01

    In order to investigate the bovine calcined bone's ability of repairing segmental bone defect and seek a new artificial bone substitute material, the bovine calcined bone (450℃,32 h) was implanted into the 10-mm middle radial defect of rabbits with tricalcium phosphate ceramics as the control. By using the methods of histology, radiology and biomechanics their osteogenic ability were measured. It was found that the bovine calcined bone's ability of repairing bone defect was better than that of tricalcium phosphate ceramics. The histological Nilsson′s scores at 3rd, 5th, 9th week after operation were significantly increased (P<0.01). At 12th week after operation the bending strength of radius in experimental group was much higher than that of control group and turned normal. It was suggested that bovine calcined bone is an ideal artificial bone substitute material with good ability of repairing segmental bone defect and some degree of mechanical strength.

  8. Dating of cremated bones

    NARCIS (Netherlands)

    Lanting, JN; Aerts-Bijma, AT; van der Plicht, J; Boaretto, E.; Carmi, I.

    2001-01-01

    When dating unburnt bone, bone collagen, the organic fraction of the bone, is used. Collagen does not survive the heat of the cremation pyre, so dating of cremated bone has been considered impossible. Structural carbonate in the mineral fraction of the bone, however, survives the cremation process.

  9. Radioiodinated 2-hydroxy-3-(4-iodophenyl)-1-(4-phenylpiperidinyl)propane: potential radiotracer for mapping central cholinergic innervation in vivo

    Energy Technology Data Exchange (ETDEWEB)

    Efange, S.M.N.; Dutta, A.K.; Michelson, R.H.; Thomas, J.R.; Boudreau, R.J. (Minnesota Univ., Minneapolis, MN (United States)); Kung, H.F.; Billings, J. (Pennsylvania Univ., Philadelphia, PA (United States). Dept. of Radiology)

    1992-04-01

    Radioiodinated 2-hydroxy-3-(4-iodophenyl)-1-(4-phenylpiperidinyl)propane, (4-HIPP), was synthesized and evaluated as a simple vesamicol-like radiotracer for mapping cholinergic pathways in the brain. Both enantiomers of 4-HIPP exhibit significant accumulation (approx. 2% of injected dose) and prolonged retention (t[sub 1/2] > 3h) within the rat brain. The accumulation of radioiodinated 4-HIPP in the rat brain was reduced by up to 70% in the presence of vesamicol and its analogs. The levorotary isomer (-)-4-[[sup 123]I]HIPP exhibits significant accumulation in the monkey brain, with a half-life of about 9 h. Radioiodinated 4-HIPP may therefore be a useful tool for studying cholinergic pathways in the brain. (author).

  10. Axial dispersion, holdup and slip velocity of dispersed phase in a pulsed sieve plate extraction column by radiotracer residence time distribution analysis

    Energy Technology Data Exchange (ETDEWEB)

    Din, Ghiyas Ud [Department of Nuclear Engineering, Pakistan Institute of Engineering and Applied Sciences (PIEAS), P.O. Nilore, Islamabad (Pakistan); Isotope Applications Division, Pakistan Institute of Nuclear Science and Technology (PINSTECH), P.O. Nilore, Islamabad (Pakistan)], E-mail: fac192@pieas.edu.pk; Chughtai, Imran Rafiq; Inayat, Mansoor Hameed [Department of Chemical and Materials Engineering, Pakistan Institute of Engineering and Applied Sciences (PIEAS), P.O. Nilore, Islamabad (Pakistan); Khan, Iqbal Hussain [Isotope Applications Division, Pakistan Institute of Nuclear Science and Technology (PINSTECH), P.O. Nilore, Islamabad (Pakistan)

    2008-12-15

    Axial dispersion, holdup and slip velocity of dispersed phase have been investigated for a range of dispersed and continuous phase superficial velocities in a pulsed sieve plate extraction column using radiotracer residence time distribution (RTD) analysis. Axial dispersion model (ADM) was used to simulate the hydrodynamics of the system. It has been observed that increase in dispersed phase superficial velocity results in a decrease in its axial dispersion and increase in its slip velocity while its holdup increases till a maximum asymptotic value is achieved. An increase in superficial velocity of continuous phase increases the axial dispersion and holdup of dispersed phase until a maximum value is obtained, while slip velocity of dispersed phase is found to decrease in the beginning and then it increases with increase in superficial velocity of continuous phase.

  11. Inappropriate cervical injection of radiotracer for sentinel node mapping in a uterine cervix cancer patient: importance of lymphoscintigraphy and blue dye injection

    Directory of Open Access Journals (Sweden)

    Sima Kadkhodayan

    2014-10-01

    Full Text Available Herein, we report a case of sentinel lymph node mapping in a uterine cervix cancer patient, referring to the nuclear medicine department of our institute. Lymphoscintigraphy images showed inappropriate intra‐cervical injection of radiotracer. Blue dye technique was applied for sentinel lymph node mapping, using intra‐cervical injection of methylene blue. Two blue/cold sentinel lymph nodes, with no pathological involvement, were intra‐operatively identified, and the patient was spared pelvic lymph node dissection. The present case underscores the importance of lymphoscintigraphy imaging in sentinel lymph node mapping and demonstrates the added value of blue dye injection in selected patients. It is suggested that preoperative lymphoscintigraphy imaging be considered as an integral part of sentinel lymph node mapping in surgical oncology. Detailed results of lymphoscintigraphy images should be provided for surgeons prior to surgery, and in case the sentinel lymph nodes are not visualized, use of blue dye for sentinel node mapping should be encouraged.

  12. Study of axial mixing, holdup and slip velocity of dispersed phase in a pulsed sieve plate extraction column using radiotracer technique

    Energy Technology Data Exchange (ETDEWEB)

    Ghiyas Ud Din [Department of Nuclear Engineering, Pakistan Institute of Engineering and Applied Sciences -PIEAS, P.O Nilore, Islamabad (Pakistan); Isotope Application Division, Pakistan Institute of Nuclear Science and Technology - PINSTECH, P.O Nilore, Islamabad (Pakistan)], E-mail: fac192@pieas.edu.pk; Imran Rafiq Chughtai; Mansoor Hameed Inayat [Department of Chemical and Materials Engineering, Pakistan Institute of Engineering and Applied Sciences - PIEAS, P.O Nilore, Islamabad (Pakistan); Iqbal Hussain Khan [Isotope Application Division, Pakistan Institute of Nuclear Science and Technology - PINSTECH, P.O Nilore, Islamabad (Pakistan)

    2009-07-15

    Axial mixing, holdup and slip velocity of dispersed phase which are parameters of fundamental importance in the design and operation of liquid-liquid extraction pulsed sieve plate columns have been investigated. Experiments for residence time distribution (RTD) analysis have been carried out for a range of pulsation frequency and amplitude in a liquid-liquid extraction pulsed sieve plate column with water as dispersed and kerosene as continuous phase using radiotracer technique. The column was operated in emulsion region and {sup 99m}Tc in the form of sodium pertechnetate eluted from a {sup 99}Mo/{sup 99m}Tc generator was used to trace the dispersed phase. Axial dispersed plug flow model with open-open boundary condition and two points measurement method was used to simulate the hydrodynamics of dispersed phase. It has been observed that the axial mixing and holdup of dispersed phase increases with increase in pulsation frequency and amplitude until a maximum value is achieved while slip velocity decreases with increase in pulsation frequency and amplitude until it approaches a minimum value. Short lived and low energy radiotracer {sup 99m}Tc in the form of sodium pertechnetate was found to be a good water tracer to study the hydrodynamics of a liquid-liquid extraction pulsed sieve plate column operating with two immiscible liquids, water and kerosene. Axial dispersed plug flow model with open-open boundary condition was found to be a suitable model to describe the hydrodynamics of dispersed phase in the pulsed sieve plate extraction column.

  13. Radium-223 treatment of bone metastases from castration-resistant prostate cancer

    DEFF Research Database (Denmark)

    Mortensen, Jann; Højgaard, Liselotte

    2014-01-01

    The alpha emitter Radium-223 ((22)3Ra-Cl2) is a bone-seeking radionuclide studied as a new treatment for patients with bone metastases from hormone refractory prostate cancer. More than 1,000 patients have been included in clinical phase I-III tests showing significant reduction in alkaline...

  14. An anlaysis of engineers information seeking activity

    DEFF Research Database (Denmark)

    Cash, Philip; Stanković, Tino; Štorga, Mario

    2013-01-01

    Information seeking is an important part of the engineering design process. In this context the Internet has become a significant source of information, shaping the way engineers work and interact. Current work has focused on characterizing this activity in terms of total time allocated to differ...... complete, the visual network analysis is used to explore patterns of information seeking and other design activity. Based on the results, three clearly differentiated types of information seeking activity are identified and discussed.......Information seeking is an important part of the engineering design process. In this context the Internet has become a significant source of information, shaping the way engineers work and interact. Current work has focused on characterizing this activity in terms of total time allocated...... to different information sources or overall tasks, such as evaluating. However, these approaches do not give an understanding of how engineers information seeking affects their problem solving activity and ultimately their performance in the context of the design process. As such, a new approach is needed...

  15. Mechanisms of host seeking by parasitic nematodes.

    Science.gov (United States)

    Gang, Spencer S; Hallem, Elissa A

    2016-07-01

    The phylum Nematoda comprises a diverse group of roundworms that includes parasites of vertebrates, invertebrates, and plants. Human-parasitic nematodes infect more than one billion people worldwide and cause some of the most common neglected tropical diseases, particularly in low-resource countries [1]. Parasitic nematodes of livestock and crops result in billions of dollars in losses each year [1]. Many nematode infections are treatable with low-cost anthelmintic drugs, but repeated infections are common in endemic areas and drug resistance is a growing concern with increasing therapeutic and agricultural administration [1]. Many parasitic nematodes have an environmental infective larval stage that engages in host seeking, a process whereby the infective larvae use sensory cues to search for hosts. Host seeking is a complex behavior that involves multiple sensory modalities, including olfaction, gustation, thermosensation, and humidity sensation. As the initial step of the parasite-host interaction, host seeking could be a powerful target for preventative intervention. However, host-seeking behavior remains poorly understood. Here we review what is currently known about the host-seeking behaviors of different parasitic nematodes, including insect-parasitic nematodes, mammalian-parasitic nematodes, and plant-parasitic nematodes. We also discuss the neural bases of these behaviors.

  16. Smoking and Bone Health

    Science.gov (United States)

    ... supported by your browser. Home Bone Basics Lifestyle Smoking and Bone Health Publication available in: PDF (85 ... late to adopt new habits for healthy bones. Smoking and Osteoporosis Cigarette smoking was first identified as ...

  17. Anorexia nervosa and bone

    National Research Council Canada - National Science Library

    Misra, Madhusmita; Klibanski, Anne

    2014-01-01

    Anorexia nervosa (AN) is a condition of severe low weight that is associated with low bone mass, impaired bone structure, and reduced bone strength, all of which contribute to increased fracture risk...

  18. Menopause and Bone Loss

    Science.gov (United States)

    Fact Sheet & Menopause Bone Loss How are bone loss and menopause related? Throughout life your body keeps a balance between the ... lose bone faster than it can be replaced. Menopause—the time when menstrual periods end, which usually ...

  19. Disturbances of fluid balance reduce the image quality of bone scintigraphy. Experimental studies in mice

    Energy Technology Data Exchange (ETDEWEB)

    Cronhjort, M.; Schnell, P.-O.; Jacobsson, H. (Karolinska Sjukhuset, Stockholm (Sweden))

    1994-06-01

    The effects of hydration, dehydration and osmotic diuresis on the activity distribution of bone-seeking radiopharmaceuticals have been studied in an experimental mouse system. It was found that any change of the water balance impairs the activity distribution of the radiolabelled phosphonate in the potential bone scintigraphic image. The findings suggest that in order to maintain image quality, elderly patients should not be instructed to drink a large volume of fluid after the administration of a bone-seeking radiopharmaceutical. Further investigations, though, have to be performed in humans. (author).

  20. Help Seeking in Online Collaborative Groupwork: A Multilevel Analysis

    Science.gov (United States)

    Du, Jianxia; Xu, Jianzhong; Fan, Xitao

    2015-01-01

    This study examined predictive models for students' help seeking in the context of online collaborative groupwork. Results from multilevel analysis revealed that most of the variance in help seeking was at the individual student level, and multiple variables at the individual level were predictive of help-seeking behaviour. Help seeking was…

  1. Help Seeking in Online Collaborative Groupwork: A Multilevel Analysis

    Science.gov (United States)

    Du, Jianxia; Xu, Jianzhong; Fan, Xitao

    2015-01-01

    This study examined predictive models for students' help seeking in the context of online collaborative groupwork. Results from multilevel analysis revealed that most of the variance in help seeking was at the individual student level, and multiple variables at the individual level were predictive of help-seeking behaviour. Help seeking was…

  2. Memory complaints associated with seeking clinical care

    NARCIS (Netherlands)

    Pires, C.; Silva, D.; Maroco, J.; Ginó, S.; Mendes, T.; Schmand, B.A.; Guerreiro, M.; de Mendonça, A.

    2012-01-01

    Diagnosis of mild cognitive impairment relies on the presence of memory complaints. However, memory complaints are very frequent in healthy people. The objective of this study was to determine the severity and type of memory difficulties presented by elderly patients who seek for clinical help, as c

  3. Assertiveness Training for Job-Seeking Skills

    Science.gov (United States)

    Ball, Patricia G.; McLoughlin, Mary Ellen

    1977-01-01

    Assertiveness Training for Job-Seeking Skills includes skill development in initiating the job search; arranging actual interviews; preparing a resume; articulating strengths, weaknesses, and career objectives; responding assertively in interviews; asking appropriate questions; accepting or rejecting job offers; confronting discrimination;…

  4. Assertiveness Training for Job-Seeking Skills

    Science.gov (United States)

    Ball, Patricia G.; McLoughlin, Mary Ellen

    1977-01-01

    Assertiveness Training for Job-Seeking Skills includes skill development in initiating the job search; arranging actual interviews; preparing a resume; articulating strengths, weaknesses, and career objectives; responding assertively in interviews; asking appropriate questions; accepting or rejecting job offers; confronting discrimination;…

  5. Information seeking behaviour of online museum visitors

    DEFF Research Database (Denmark)

    Skov, Mette

    two research projects on online museum visitors. The first case study will illustrate the information seeking and searching characteristics of online museum visitors at the National Museum of Military History in Copenhagen. Participants in this case study are characterised as special interest museum...

  6. Introducing “Seeking Truth in Love”

    Institute of Scientific and Technical Information of China (English)

    Theresa; Carino

    2006-01-01

    An excellent guide and commentary on Bishop KH Ting’s writings by scholars from Asia, Europe and North America, the bilingual volume Seeking Truth in Love"is now available at bookstores in China. Compiled and edited by Wang Peng,Dean of Studies at Nanjing Union Theological Seminary,the 393-page book was published in February,2006 by the Reli-

  7. Unaccompanied Asylum-Seeking Children: Whose Perspective?

    Science.gov (United States)

    Wernesjo, Ulrika

    2012-01-01

    Recent years have seen increasing attention being paid to unaccompanied asylum-seeking children. This article provides an overview of research in the field and its implications for an understanding of these children as a particularly vulnerable category. The existing research focuses primarily on investigating the children's emotional well-being…

  8. Health-Seeking Behavior Among the Elderly.

    Science.gov (United States)

    Bausell, R. Barker

    1986-01-01

    Compared persons 65 years of age or older (N=177) to younger adults (n=997) with respect to compliance with 20 recommended health-seeking behaviors. Overall, the elderly group reported greater compliance with these behaviors, attributed more importance to their value, but perceived themselves as having less control over their future health.…

  9. Rent seeking with efforts and bids

    NARCIS (Netherlands)

    Haan, M.A.; Schoonbeek, L.

    2003-01-01

    We introduce bids in a rent-seeking contest. Players compete for a prize. Apart from exerting lobbying efforts, they also submit a bid which is payable only if they win the prize. We show that our model has a unique Nash equilibrium in pure strategies, in which each active player submits the same bi

  10. Understanding cultural heritage experts’ information seeking needs

    NARCIS (Netherlands)

    A.K. Amin (Alia); J.R. van Ossenbruggen (Jacco); L. Hardman (Lynda); A. van Nispen

    2008-01-01

    htmlabstractWe report on our user study on the information seeking behavior of cultural heritage experts and the sources they use to carry out search tasks. Seventeen experts from nine cultural heritage institutes in the Netherlands were interviewed and asked to answer questionnaires about their

  11. Physicians' Internet Information-Seeking Behaviors

    Science.gov (United States)

    Bennett, Nancy L.; Casebeer, Linda L.; Kristofco, Robert E.; Strasser, Sheryl M.

    2004-01-01

    Introduction: Our understanding about the role of the Internet as a resource for physicians has improved in the past several years with reports of patterns for use and measures of impact on medical practice. The purpose of this study was to begin to shape a theory base for more fully describing physicians' information-seeking behaviors as they…

  12. Interactive information seeking, behaviour and retrieval

    CERN Document Server

    Ruthven, Ian

    2011-01-01

    Information retrieval (IR) is a complex human activity supported by sophisticated systems. This book covers the whole spectrum of information retrieval, including: history and background information; behaviour and seeking task-based information; searching and retrieval approaches to investigating information; and, evaluation interfaces for IR.

  13. Multitasking Information Seeking and Searching Processes.

    Science.gov (United States)

    Spink, Amanda; Ozmutlu, H. Cenk; Ozmutlu, Seda

    2002-01-01

    Presents findings from four studies of the prevalence of multitasking information seeking and searching by Web (via the Excite search engine), information retrieval system (mediated online database searching), and academic library users. Highlights include human information coordinating behavior (HICB); and implications for models of information…

  14. Leaders, laggards and technology seeking strategies

    NARCIS (Netherlands)

    Smeets, Roger; Bosker, E. M.

    2011-01-01

    We analyze the conditions determining optimal technology seeking strategies for leader and laggard firms. We extend existing theories by differentiating leaders and laggards in terms of absorptive capacity and intra-firm technology transfer skills, next to productivity levels. In addition, both Fore

  15. Information Seeking in a Virtual Learning Environment.

    Science.gov (United States)

    Byron, Suzanne M.; Young, Jon I.

    2000-01-01

    Examines the applicability of Kuhlthau's Information Search Process Model in the context of a virtual learning environment at the University of North Texas that used virtual collaborative software. Highlights include cognitive and affective aspects of information seeking; computer experience and confidence; and implications for future research.…

  16. A Principle of Uncertainty for Information Seeking.

    Science.gov (United States)

    Kuhlthau, Carol C.

    1993-01-01

    Proposes an uncertainty principle for information seeking based on the results of a series of studies that investigated the user's perspective of the information search process. Constructivist theory is discussed as a conceptual framework for studying the user's perspective, and areas for further research are suggested. (Contains 44 references.)…

  17. Changing Attitudes toward Seeking Professional Help.

    Science.gov (United States)

    Chrisler, Joan C.

    Despite the increasing acceptance of the value of psychotherapy, there are still those who think people should solve their own problems. A study was conducted to investigate the attitudes of college students toward seeking professional help before and after taking a course in abnormal psychology to determine whether exposure to the purposes and…

  18. Unaccompanied Asylum-Seeking Children: Whose Perspective?

    Science.gov (United States)

    Wernesjo, Ulrika

    2012-01-01

    Recent years have seen increasing attention being paid to unaccompanied asylum-seeking children. This article provides an overview of research in the field and its implications for an understanding of these children as a particularly vulnerable category. The existing research focuses primarily on investigating the children's emotional well-being…

  19. Multitasking Information Seeking and Searching Processes.

    Science.gov (United States)

    Spink, Amanda; Ozmutlu, H. Cenk; Ozmutlu, Seda

    2002-01-01

    Presents findings from four studies of the prevalence of multitasking information seeking and searching by Web (via the Excite search engine), information retrieval system (mediated online database searching), and academic library users. Highlights include human information coordinating behavior (HICB); and implications for models of information…

  20. Memory Loss: When to Seek Help

    Science.gov (United States)

    Memory loss: When to seek help A number of conditions — not only Alzheimer's disease — can cause memory loss in older adults. Getting a prompt diagnosis ... a person you just met? Some degree of memory problems, as well as a modest decline in ...

  1. Bone grafting: An overview

    Directory of Open Access Journals (Sweden)

    D. O. Joshi

    2010-08-01

    Full Text Available Bone grafting is the process by which bone is transferred from a source (donor to site (recipient. Due to trauma from accidents by speedy vehicles, falling down from height or gunshot injury particularly in human being, acquired or developmental diseases like rickets, congenital defects like abnormal bone development, wearing out because of age and overuse; lead to bone loss and to replace the loss we need the bone grafting. Osteogenesis, osteoinduction, osteoconduction, mechanical supports are the four basic mechanisms of bone graft. Bone graft can be harvested from the iliac crest, proximal tibia, proximal humerus, proximal femur, ribs and sternum. An ideal bone graft material is biologically inert, source of osteogenic, act as a mechanical support, readily available, easily adaptable in terms of size, shape, length and replaced by the host bone. Except blood, bone is grafted with greater frequency. Bone graft indicated for variety of orthopedic abnormalities, comminuted fractures, delayed unions, non-unions, arthrodesis and osteomyelitis. Bone graft can be harvested from the iliac crest, proximal tibia, proximal humerus, proximal femur, ribs and sternum. By adopting different procedure of graft preservation its antigenicity can be minimized. The concept of bone banking for obtaining bone grafts and implants is very useful for clinical application. Absolute stability require for successful incorporation. Ideal bone graft must possess osteogenic, osteoinductive and osteocon-ductive properties. Cancellous bone graft is superior to cortical bone graft. Usually autologous cancellous bone graft are used as fresh grafts where as allografts are employed as an alloimplant. None of the available type of bone grafts possesses all these properties therefore, a single type of graft cannot be recomm-ended for all types of orthopedic abnormalities. Bone grafts and implants can be selected as per clinical problems, the equipments available and preference of

  2. Bone Marrow Diseases

    Science.gov (United States)

    Bone marrow is the spongy tissue inside some of your bones, such as your hip and thigh bones. It contains stem cells. The stem cells can ... the platelets that help with blood clotting. With bone marrow disease, there are problems with the stem ...

  3. Orchestration of bone remodeling

    NARCIS (Netherlands)

    Moester, Martiene Johanna Catharina

    2014-01-01

    In healthy individuals, a balance exists between bone formation and resorption. Disruption of this balance can lead to higher or lower bone mass, and disease such as osteoporosis. Treatment for osteoporosis generally inhibits bone resorption, but does not rebuild bone to a healthy strength. More kno

  4. Bone grafts in dentistry

    Directory of Open Access Journals (Sweden)

    Prasanna Kumar

    2013-01-01

    Full Text Available Bone grafts are used as a filler and scaffold to facilitate bone formation and promote wound healing. These grafts are bioresorbable and have no antigen-antibody reaction. These bone grafts act as a mineral reservoir which induces new bone formation.

  5. Bone Health and Osteoporosis.

    Science.gov (United States)

    Lupsa, Beatrice C; Insogna, Karl

    2015-09-01

    Osteoporosis is characterized by low bone mass and microarchitectural deterioration of bone tissue leading to decreased bone strength and an increased risk of low-energy fractures. Central dual-energy X-ray absorptiometry measurements are the gold standard for determining bone mineral density. Bone loss is an inevitable consequence of the decrease in estrogen levels during and following menopause, but additional risk factors for bone loss can also contribute to osteoporosis in older women. A well-balanced diet, exercise, and smoking cessation are key to maintaining bone health as women age. Pharmacologic agents should be recommended in patients at high risk for fracture.

  6. BONE IN OSTEOPETROSIS

    Directory of Open Access Journals (Sweden)

    Ramkumar

    2014-04-01

    Full Text Available Osteopetrosis, a generalized developmental bone disease due to genetic disturbances, characterized by failure of bone re sorption and continuous bone formation making the bone hard, dense and brittle. Bones of intramembranous ossification and enchondrial ossification are affected genetically and symmetrically. During the process of disease the excess bone formation obliterates the cranial foramina and presses the optic, auditory and facial nerves resulting in defective vision, impaired hearing and facial paralysis. The bone formation in osteopetrosis affects bone marrow function leading to severe anemia and deficient of blood cells. The bone devoid of blood supply due to compression of blood vessels by excess formation of bone are prone to osteomyelitic changes with suppuration and pathological fracture if exposed to infection. Though the condition is chronic progressive, it produces changes leading to fatal condition, it should be studied thoroughly by everyone and hence this article presents a classical case of osteopetrosis with detailed description and discussion for the benefit of readers

  7. Development of a fluidized-bed method for on-line evaluation of radiotracers in vitro; Entwicklung einer Fliessbettechnik zur Bewertung von Radiopharmaka an Zellkulturen

    Energy Technology Data Exchange (ETDEWEB)

    Noll, T.

    1999-05-01

    This study presents the development of a continuously operating fluidized-bed bioreactor for on-line evaluation of radiotracers in vitro, which combines tissue-like three-dimensional cell cultivation in open porous microcarriers with a technique for on-line radioactivity detection. The long time stability of steady-state permits a large number of experiments using the same culture. All relevant parameters (O{sub 2}, pH, T, etc.) can be adjusted according to the experimental requirements. The flux of the circulating medium can be adapted to the blood flow of the corresponding organism, while the input function of the radiotracer is freely adjustable for simulation of in vivo conditions. Sampling and examination of the immobilized cells care possible at any time. Using this system, the kinetics of 2-[{sup 18}F]fluoro-2-deoxyglucose (FDG) in human glioma cells (86HG39) were studied and it was shown that the dependence of the lumped constant (LC) for FDG on the medium glucose concentration is similar to that obtained in the rat brain. For normoglycemic concentrations the LC was determined to be in the range of 0.7, while in hypoglycemia it increased progressively up to a value of 1.22 at a glucose concentration of 3 mM. The rate constants in the three compartment model were found to be similar to those obtained in vivo using PET; indicating the validity of the system for tracer evaluation. Furthermore the kinetics of both diastereomeric forms of 4-[{sup 18}F]fluoro-proline was investigated and found that both diastereomeres were not metabolized and reached an identical intracellular steady state concentration. The trans-form was transported three times faster than the cis-diastereomere, indicated by the rate constants. (orig.) [German] Diese Arbeit beschreibt die Entwicklung eines kontinuierlich betriebenen Wirbelschichtreaktors zur on-line Bewertung von Radiotracern an Zellkulturen. Der Bioreaktor kombiniert eine gewebeaehnliche, dreidimensionale Zellkultivierung in

  8. Novel (99m)Tc(III) Complexes [(99m)TcCl(CDO)(CDOH)2B-R] (CDOH2 = Cyclohexanedione Dioxime) Useful as Radiotracers for Heart Imaging.

    Science.gov (United States)

    Liu, Min; Fang, Wei; Liu, Shuang

    2016-11-16

    In this study, we evaluated seven new (99m)Tc(III) complexes [(99m)TcCl(CDO)(CDOH)2B-R] ((99m)Tc-2Fboroxime: R = 2-formylfuran-3-yl (2F); (99m)Tc-3Fboroxime: R = furan-3-yl (3F); (99m)Tc-5Fboroxime: R = 5-formyfuran-2-yl (5F); (99m)Tc-HPboroxime: R = 6-hydroxylpyridin-2-yl (HP); (99m)Tc-MPYboroxime: R = 5-methoxypyridin-3-yl (MPY); (99m)Tc-PMboroxime: R = 1,5-pyrimidin-3-yl (PM); and (99m)Tc-4PYboroxime: R = pyridin-4-yl (4PY)) for their potential as heart imaging agents. All new (99m)Tc(III) radiotracers except (99m)Tc-2Fboroxime were prepared with high radiochemical purity (RCP > 95%). The low RCP (∼75%) for (99m)Tc-2Fboroxime is most likely caused by steric hindrance from the 3-formyl group. Biodistribution and imaging studies were performed in SD rats. Planar image quantification was performed to compare their myocardial retention times. We found that the myocardial washout curves of new (99m)Tc(III) radiotracers were best fitted the biexponential decay function. The AUC (area under the curve) values followed the general trend: (99m)Tc-5Fboroxime (129 ± 6) > (99m)Tc-3Fboroxime (114 ± 11) > (99m)Tc-Teboroxime (104 ± 16) > (99m)Tc-MPYboroxime (92 ± 18) > (99m)Tc-4PYboroxime (77 ± 10) > (99m)Tc-PMboroxime (68 ± 14) ≈ (99m)Tc-HPboroxime (62 ± 14). The 2 min heart uptake values from biodistribution studies follow the ranking order of (99m)Tc-5Fboroxime (3.75 ± 0.15%ID/g) ≈ (99m)Tc-MPYboroxime (3.73 ± 0.24%ID/g) > (99m)Tc-PMboroxime (3.47 ± 0.15%ID/g) ≈ (99m)Tc-3Fboroxime ≈ (3.25 ± 0.77%ID/g). The 5 min heart uptake of (99m)Tc-5Fboroxime (3.91 ± 0.09%ID/g) was almost identical to its 2 min heart uptake (3.75 ± 0.15%ID/g), and its 15 min heart uptake value (2.83 ± 0.08%ID/g) compared well to the 2 min heart uptake of (99m)Tc-Teboroxime (3.00 ± 0.37%ID/g). It took ∼5 min for (99m)Tc-5Fboroxime to approach the 1 min heart uptake value of (99m)Tc-Teboroxime (∼3.5% ID/g) and ∼9.5 min to reach the 2 min heart uptake value of (99m

  9. Health Seeking Behaviour of Elderly in Myanmar

    Directory of Open Access Journals (Sweden)

    Soe Moe

    2012-08-01

    Full Text Available Introduction: Improvement in health technologies and socio economic conditions increase life expectancy of people leading to higher proportion of elderly in total population of every country worldwide. Developing countries have less comprehensive policy and elderly health agenda, and Myanmar is not an exception. The World Health Organization highlighted that aging process and problems related to elderly should be better understood so that effective elderly health prevention can be planned and implemented. However, there are very limited studies in Myanmar for aging health care. Objective: 1 To identify the Health status of aging population in selected townships of upper and lower Myanmar. 2 To identify the health seeking behavior of elderly. 3 To find out the association between the health seeking behavior of elderly and socio-demographic characteristics. Method: This is a cross sectional survey to study health status and health seeking behavior of the elderly people in Myanmar. Study areas are Taungu from Lower Myanmar and Ye Oo from Upper Myanmar both of which are not under cover of elderly project and have no adequate data for elderly health care. Sample size calculation was done by Epi Info StatCalc. Total 729 elderly were under study. According to elderly population in Taungu and Ye Oo, 1/3 of the sample was taken from Taungu and 2/3 taken from Ye Oo. Result: Male, Female ratio of study population is 1:1.44. Around half of elderly population has primary or lower level education, only one third are working but with low income. One third of male and female elderly perceived that they are in good health. Regarding illnesses present at the time of interview, three percent of male and thirteen percent of female did not get treatment. Significant difference between the health seeking behavior of upper and lower Myanmar was seen with chi square alue 1155, P= <00000001. Health seeking behavior was not associated with Gender, ethnicity, religion

  10. Improved Estrogen Receptor Assessment by PET Using the Novel Radiotracer 4FMFES in ER+ Breast Cancer Patients: an Ongoing Phase II Clinical Trial.

    Science.gov (United States)

    Paquette, Michel; Lavallée, Éric; Phoenix, Serge; Ouellet, René; Senta, Helena; van Lier, Johan E; Guérin, Brigitte; Lecomte, Roger; Turcotte, Éric E

    2017-08-10

    Following encouraging preclinical and human dosimetry results for the novel estrogen receptor (ER) positron emission tomography (PET) radiotracer 4-fluoro-11β-methoxy-16α-[(18)F]fluoroestradiol (4FMFES), a phase II clinical trial was initiated to compare the PET imaging diagnostic potential of 4FMFES to 16α-[(18)F]fluoroestradiol (FES) in ER positive (ER+) breast cancer patients. Methods: Patients diagnosed with ER+ breast cancer (n = 31) were recruited for this study, including six patients that undertook mastectomy and/or axillary node dissection. For each patient, FES- and 4FMFES-PET/CT scans were done sequentially (within a week) and in random order. One hour following injection of either radiotracer, a head-to-thigh static scan with 2 minutes acquisition per bed position was obtained. Blood samples were taken at different times following injection to assess each tracer metabolism by reverse-phase thin-layer chromatography (TLC). The mean standardized uptake values (SUVMean) of non-specific tissues and the maximum SUV (SUVMax) of the tumor were evaluated for each detected lesion, and tumor-to-non-specific organs ratios were calculated. Results: Blood metabolite analysis 60 minutes after injection of the tracer showed a 2.5-fold increase in metabolic stability of 4FMFES over FES. While for most foci 4FMFES-PET scored similar SUVMax values as compared to FES-PET, tumor contrast improved substantially in all cases. Lower uptake was consistently observed in non-specific tissues for 4FMFES, notably a 4-fold decrease in blood pool activity as compared to FES. Consequently, image quality was considerably improved using 4FMFES, with lower overall background. As a result, 4FMFES successfully identified 9 more lesions than FES. Conclusion: This phase II study with ER+ breast cancer patients shows that 4FMFES-PET achieves lower non-specific signal and better tumor contrast than FES-PET resulting in improved diagnostic confidence and lower false negative diagnoses

  11. Discovery of a fluorinated 4-oxo-quinoline derivative as a potential positron emission tomography radiotracer for imaging cannabinoid receptor type 2.

    Science.gov (United States)

    Slavik, Roger; Müller Herde, Adrienne; Haider, Ahmed; Krämer, Stefanie D; Weber, Markus; Schibli, Roger; Ametamey, Simon M; Mu, Linjing

    2016-09-01

    The cannabinoid receptor type 2 (CB2) is part of the endocannabinoid system and has gained growing attention in recent years because of its important role in neuroinflammatory/neurodegenerative diseases. Recently, we reported on a carbon-11 labeled 4-oxo-quinoline derivative, designated RS-016, as a promising radiotracer for imaging CB2 using PET. In this study, three novel fluorinated analogs of RS-016 were designed, synthesized, and pharmacologically evaluated. The results of our efforts led to the identification of N-(1-adamantyl)-1-(2-(2-fluoroethoxy)ethyl)-8-methoxy-4-oxo-1,4-dihydroquinoline-3-carboxamide (RS-126) as the most potent candidate for evaluation as a CB2 PET ligand. [(18) F]RS-126 was obtained in ≥ 99% radiochemical purity with an average specific radioactivity of 98 GBq/μmol at the end of the radiosynthesis. [(18) F]RS-126 showed a logD7.4 value of 1.99 and is stable in vitro in rat and human plasma over 120 min, whereas 55% intact parent compound was found in vivo in rat blood plasma at 10 min post injection. In vitro autoradiographic studies with CB2-positive rat spleen tissue revealed high and blockable binding which was confirmed in in vivo displacement experiments with rats by dynamic PET imaging. Ex vivo biodistribution studies confirmed accumulation of [(18) F]RS-126 in rat spleen with a specificity of 79% under blocking conditions. The moderate elevated CB2 levels in LPS-treated mice brain did not permit the detection of CB2 by [(18) F]RS-126 using PET imaging. In summary, [(18) F]RS-126 demonstrated high specificity toward CB2 receptor in vitro and in vivo and is a promising radioligand for imaging CB2 receptor expression. Cannabinoid receptor type 2 (CB2) is an interesting target for PET imaging. Specific binding of [(18) F]RS-126 in CB2-positive spleen tissue (white arrow head) was confirmed in in vivo displacement experiments with rats. Time activity curve of [(18) F]RS-126 in the spleen after the addition of GW405833 (CB2

  12. Synthesis and characterization of (68)Ga-labeled curcumin and curcuminoid complexes as potential radiotracers for imaging of cancer and Alzheimer's disease.

    Science.gov (United States)

    Asti, Mattia; Ferrari, Erika; Croci, Stefania; Atti, Giulia; Rubagotti, Sara; Iori, Michele; Capponi, Pier C; Zerbini, Alessandro; Saladini, Monica; Versari, Annibale

    2014-05-19

    Curcumin (CUR) and curcuminoids complexes labeled with fluorine-18 or technetium-99m have recently shown their potential as diagnostic tools for Alzheimer's disease. Gallium-68 is a positron-emitting, generator-produced radionuclide, and its properties can be exploited in situ in medical facilities without a cyclotron. Moreover, CUR showed a higher uptake in tumor cells compared to normal cells, suggesting potential diagnostic applications in this field. In spite of this, no studies using labeled CUR have been performed in this direction, so far. Herein, (68)Ga-labeled complexes with CUR and two curcuminoids, namely diacetyl-curcumin (DAC) and bis(dehydroxy)curcumin (bDHC), were synthesized and characterized by means of experimental and theoretical approaches. Moreover, a first evaluation of their affinity to synthetic β-amyloid fibrils and uptake by A549 lung cancer cells was performed to show the potential application of these new labeled curcuminoids in these diagnostic fields. The radiotracers were prepared by reacting (68)Ga(3+) obtained from a (68)Ge/(68)Ga generator with 1 mg/mL curcuminoids solutions. Reaction parameters (precursor amount, reaction temperature, and pH) were optimized to obtain high and reproducible radiochemical yield and purity. Stoichiometry and formation of the curcuminoid complexes were investigated by matrix-assisted laser desorption ionization time-of-flight mass spectrometry, NMR, ultraviolet-visible, and fluorescence spectroscopy on the equivalent (nat)Ga-curcuminoids (nat = natural) complexes, and their structure was computed by theoretical density functional theory calculations. The analyses evidenced that CUR, DAC, and bDHC were predominantly in the keto-enol form and attested to Ga(L)2(+) species formation. Identity of the (68)Ga(L)2(+) complexes was confirmed by coelution with the equivalent (nat)Ga(L)2(+) complexes in ultrahigh-performance liquid chromatography analyses.(68)Ga(CUR)2(+), (68)Ga(DAC)2(+), and (68)Ga(bDHC)2

  13. Bone cysts: unicameral and aneurysmal bone cyst.

    Science.gov (United States)

    Mascard, E; Gomez-Brouchet, A; Lambot, K

    2015-02-01

    Simple and aneurysmal bone cysts are benign lytic bone lesions, usually encountered in children and adolescents. Simple bone cyst is a cystic, fluid-filled lesion, which may be unicameral (UBC) or partially separated. UBC can involve all bones, but usually the long bone metaphysis and otherwise primarily the proximal humerus and proximal femur. The classic aneurysmal bone cyst (ABC) is an expansive and hemorrhagic tumor, usually showing characteristic translocation. About 30% of ABCs are secondary, without translocation; they occur in reaction to another, usually benign, bone lesion. ABCs are metaphyseal, excentric, bulging, fluid-filled and multicameral, and may develop in all bones of the skeleton. On MRI, the fluid level is evocative. It is mandatory to distinguish ABC from UBC, as prognosis and treatment are different. UBCs resolve spontaneously between adolescence and adulthood; the main concern is the risk of pathologic fracture. Treatment in non-threatening forms consists in intracystic injection of methylprednisolone. When there is a risk of fracture, especially of the femoral neck, surgery with curettage, filling with bone substitute or graft and osteosynthesis may be required. ABCs are potentially more aggressive, with a risk of bone destruction. Diagnosis must systematically be confirmed by biopsy, identifying soft-tissue parts, as telangiectatic sarcoma can mimic ABC. Intra-lesional sclerotherapy with alcohol is an effective treatment. In spinal ABC and in aggressive lesions with a risk of fracture, surgical treatment should be preferred, possibly after preoperative embolization. The risk of malignant transformation is very low, except in case of radiation therapy.

  14. Health information seeking in the information society.

    Science.gov (United States)

    Mukherjee, Abir; Bawden, David

    2012-09-01

    This article is the second student contribution to the Dissertations into Practice feature. It reports on a study that investigated the everyday health information-seeking practices of a small group of the 'general public' and the implications for information-seeking theory and health information provision. The first student article, about the implementation of radio frequency identification (RFID) in a hospital library, was very different, and the two articles illustrate the broad spectrum of possible subjects for the Dissertations into Practice feature. This study was conducted in summer 2011 by Abir Mukherjee for his MSc dissertation in the Library and Information Sciences programme at City University London. Further information and copies of the full dissertation may be obtained from Abir Mukherjee or David Bawden. AM.

  15. Stochastic Averaging and Stochastic Extremum Seeking

    CERN Document Server

    Liu, Shu-Jun

    2012-01-01

    Stochastic Averaging and Stochastic Extremum Seeking develops methods of mathematical analysis inspired by the interest in reverse engineering  and analysis of bacterial  convergence by chemotaxis and to apply similar stochastic optimization techniques in other environments. The first half of the text presents significant advances in stochastic averaging theory, necessitated by the fact that existing theorems are restricted to systems with linear growth, globally exponentially stable average models, vanishing stochastic perturbations, and prevent analysis over infinite time horizon. The second half of the text introduces stochastic extremum seeking algorithms for model-free optimization of systems in real time using stochastic perturbations for estimation of their gradients. Both gradient- and Newton-based algorithms are presented, offering the user the choice between the simplicity of implementation (gradient) and the ability to achieve a known, arbitrary convergence rate (Newton). The design of algorithms...

  16. Journey to seek the meaning of life

    Institute of Scientific and Technical Information of China (English)

    田亚楠

    2015-01-01

    It’s about my journey to seek the meaning of life. What’s the meaning of life? I found the life of great men were really meaningful, but what about the life of ordinary people? Is their life meaningless? Through my observation and thinking, I have that the life of ordinary people is also meaningful as long as they live their life to the fullest.

  17. Nigeria Seeks Energy Investment from China

    Institute of Scientific and Technical Information of China (English)

    Shan Wenge

    2006-01-01

    @@ Nigeria sent a delegation to China in mid-July to seek investment in the oil-enriched nation. Currently, Nigeria has granted the Chinese oil companies the permits of four oil fields while the Chinese side offered technical support in the energy cooperation field. In addition to the energy sector, Nigeria's invitation of investment this time also covers transportation, finance, telecommunications and manufacturing sector.

  18. Seeking health care through international medical tourism.

    Science.gov (United States)

    Eissler, Lee Ann; Casken, John

    2013-06-01

    The purpose of this study was the exploration of international travel experiences for the purpose of medical or dental care from the perspective of patients from Alaska and to develop insight and understanding of the essence of the phenomenon of medical tourism. The study is conceptually oriented within a model of health-seeking behavior. Using a qualitative design, 15 Alaska medical tourists were individually interviewed. The data were analyzed using a hermeneutic process of inquiry to uncover the meaning of the experience. Six themes reflecting the experiences of Alaska medical tourists emerged: "my motivation," "I did the research," "the medical care I need," "follow-up care," "the advice I give," and "in the future." Subthemes further categorized data for increased understanding of the phenomenon. The thematic analysis provides insight into the experience and reflects a modern approach to health-seeking behavior through international medical tourism. The results of this study provide increased understanding of the experience of obtaining health care internationally from the patient perspective. Improved understanding of medical tourism provides additional information about a contemporary approach to health-seeking behavior. Results of this study will aid nursing professionals in counseling regarding medical tourism options and providing follow-up health care after medical tourism. Nurses will be able to actively participate in global health policy discussions regarding medical tourism trends. © 2013 Sigma Theta Tau International.

  19. GENDER-SPECIFIC INFORMATION SEEKING BEHAVIOUR

    Directory of Open Access Journals (Sweden)

    Paramita Pathak

    2017-03-01

    Full Text Available Makes an attempt to examine the validity of the construct regarding gendered information behavior. A survey was made for the purpose on a sample of eighty people covering both male and female in equal proportion from four distinct groups, namely Teacher, Student, Skilled Labour and Unskilled Labour from both urban and rural areas. Data were collected from the selected audience, using a combination of both questionnaire and interview, on a set of fixed queries. Results have revealed that the information needs as well as the information seeking behaviour, in general, among the male and female do not show any uniform and consistent pattern. The findings also have revealed that there are variations of needs and behavior for seeking information among an individual man and woman, an individual man and man, as well as an individual woman and woman. But the differences in this regard have been found as quantitative and not qualitative. The findings do not show any evidence of gendered information need as well as information seeking behavior exclusive to the male or female.

  20. Healthcare seeking behaviour among Chinese elderly.

    Science.gov (United States)

    Lu, Hui; Wang, Wei; Xu, Ling; Li, Zhenhong; Ding, Yan; Zhang, Jian; Yan, Fei

    2017-04-18

    Purpose The Chinese population is rapidly ageing before they are rich. The purpose of this paper is to describe healthcare seeking behaviour and the critical factors associated with healthcare seeking behaviour. Design/methodology/approach Using a purposive sampling method, the authors recruited 44 adults aged 60 years or older from three provinces, representing the developed (Shanghai), undeveloped (Ningxia) regions and the regions in between (Hubei). From July to September 2008, using a semi-structured guide, the authors interviewed participants in focus group discussions. Findings The healthcare needs for chronic and catastrophic diseases were high; however, the healthcare demands were low and healthcare utilizations were even lower owing to the limited accessibility to healthcare services, particularly, in underdeveloped rural areas. "Too expensive to see a doctor" was a prime complaint, explaining substantial discrepancies between healthcare needs, demands and use. Care seeking behaviour varied depending on insurance availability, perceived performance, particularly hospital services, and prescription medications. Participants consistently rated increasing healthcare accessibility as a high priority, including offering financial aid, and improving service convenience. Improving social security fairness was the first on the elderly's wish list. Originality/value Healthcare demand and use were lower than needs, and were influenced by multiple factors, primarily, service affordability and efficiency, perceived performance and hospital service quality.

  1. Evaluating information-seeking approaches to metacognition.

    Science.gov (United States)

    Crystal, Jonathon D; Foote, Allison L

    Metacognition has been divided into information monitoring and control processes. Monitoring involves knowing that you know or do not know some information without taking corrective action. Control involves taking corrective action based on the knowledge that you know or do not know some information. In comparative metacognition, considerable attention has been paid toward critically assessing putative evidence for information monitoring in non-human animals. However, less attention has been paid toward critically evaluating evidence for control processes in animals. We briefly review a critique of information-monitoring in animals. Next, we apply these concepts to a number of studies that focus on information seeking in animals. The main type of evidence for control processes in animals come from tube tipping experiments. Before having the opportunity to search for the bait in these experiments, the subject sometimes observes opaque tubes being baited but is sometimes prevented from seeing the baiting. The observations that the subjects look more if baiting was not seen and are more accurate if baiting was seen have been taken as evidence for metacognition in information-seeking experiments. We propose simple alternative hypotheses that are sufficient to explain putative evidence for information seeking in animals without positing metacognition. The alternative explanation focuses on two relatively simple principles: First, an animal has a default "look before you go" response which supersedes random searches in space. Second, spatially guided behavior follows a default rule of "go where something good is." These principles can explain the results of tube tipping experiments without proposing metacognition.

  2. Regulation of Bone Metabolism

    Science.gov (United States)

    Shahi, Maryam; Peymani, Amir; Sahmani, Mehdi

    2017-01-01

    Bone is formed through the processes of endochondral and intramembranous ossification. In endochondral ossification primary mesenchymal cells differentiate to chondrocytes and then are progressively substituted by bone, while in intramembranous ossification mesenchymal stem cells (MSCs) differentiate directly into osteoblasts to form bone. The steps of osteogenic proliferation, differentiation, and bone homeostasis are controlled by various markers and signaling pathways. Bone needs to be remodeled to maintain integrity with osteoblasts, which are bone-forming cells, and osteoclasts, which are bone-degrading cells.In this review we considered the major factors and signaling pathways in bone formation; these include fibroblast growth factors (FGFs), bone morphogenetic proteins (BMPs), wingless-type (Wnt) genes, runt-related transcription factor 2 (RUNX2) and osteoblast-specific transcription factor (osterix or OSX). PMID:28367467

  3. Regulation of Bone Metabolism.

    Science.gov (United States)

    Shahi, Maryam; Peymani, Amir; Sahmani, Mehdi

    2017-04-01

    Bone is formed through the processes of endochondral and intramembranous ossification. In endochondral ossification primary mesenchymal cells differentiate to chondrocytes and then are progressively substituted by bone, while in intramembranous ossification mesenchymal stem cells (MSCs) differentiate directly into osteoblasts to form bone. The steps of osteogenic proliferation, differentiation, and bone homeostasis are controlled by various markers and signaling pathways. Bone needs to be remodeled to maintain integrity with osteoblasts, which are bone-forming cells, and osteoclasts, which are bone-degrading cells.In this review we considered the major factors and signaling pathways in bone formation; these include fibroblast growth factors (FGFs), bone morphogenetic proteins (BMPs), wingless-type (Wnt) genes, runt-related transcription factor 2 (RUNX2) and osteoblast-specific transcription factor (osterix or OSX).

  4. Health Care Seeking Behavior in Southwest Ethiopia.

    Science.gov (United States)

    Begashaw, Bayu; Tessema, Fasil; Gesesew, Hailay Abrha

    2016-01-01

    Rural and urban populations have disparate socio-demographic and economic characteristics, which have an influence on equity and their health seeking behavior. We examined and compared the health care seeking behavior for perceived morbidity between urban and rural households in Southwest Ethiopia. Analytic cross-sectional study was conducted among urban and rural households living in Esera district of Southwest Ethiopia. A random sample of 388 head of households (126 urban and 262 rural) were selected. A pretested and structured questionnaire was used for data collection with face-to-face interview. In addition to descriptive methods, binary logistic regression was used to identify factors associated with health seeking behavior at p value of less than 0.05. Of the sample household heads, 377 (97.2%) (119 urban and 258 rural) were successfully interviewed. Among these, 58.4% (95% CI, 53.3-63.3%) of the households sought care from modern health care that was lower among rural (48.1%) than urban (80.7%) households. The prevalence of self-treatment was 35.3% in urban and 46.1% in rural households. Among the factors considered for modern health care utilization, higher monthly income (AOR, 5.6; 95% CI, 2.04-15.4), perceived severity of disease (AOR, 2.5; 95% CI, 1.1-5.8), acute duration of disease (AOR, 8.9; 95% CI, 2.4-33.3) and short distance from health facilities (AOR, 3; 95% CI, 1.2-8.4) among rural and being married (AOR, 11.3; 95% CI, 1.2-110.2) and perceived severity of disease (AOR, 6.6; 95% CI, 1.1-10.9) among urban households showed statistically significant association. The general health seeking behavior of households on perceived morbidity was satisfactory but lower in rural compared to urban households. Self-medication was also widely practiced in the study area. The findings signal the need to work more on accessibility and promotion of healthcare seeking behavior especially among rural households.

  5. Fatty acid oxidation by the osteoblast is required for normal bone acquisition in a sex- and diet-dependent manner.

    Science.gov (United States)

    Kim, Soohyun P; Li, Zhu; Zoch, Meredith L; Frey, Julie L; Bowman, Caitlyn E; Kushwaha, Priyanka; Ryan, Kathleen A; Goh, Brian C; Scafidi, Susanna; Pickett, Julie E; Faugere, Marie-Claude; Kershaw, Erin E; Thorek, Daniel L J; Clemens, Thomas L; Wolfgang, Michael J; Riddle, Ryan C

    2017-08-17

    Postnatal bone formation is influenced by nutritional status and compromised by disturbances in metabolism. The oxidation of dietary lipids represents a critical source of ATP for many cells but has been poorly studied in the skeleton, where the prevailing view is that glucose is the primary energy source. Here, we examined fatty acid uptake by bone and probed the requirement for fatty acid catabolism during bone formation by specifically disrupting the expression of carnitine palmitoyltransferase 2 (Cpt2), an obligate enzyme in fatty acid oxidation, in osteoblasts and osteocytes. Radiotracer studies demonstrated that the skeleton accumulates a significant fraction of postprandial fatty acids, which was equal to or in excess of that acquired by skeletal muscle or adipose tissue. Female, but not male, Cpt2 mutant mice exhibited significant impairments in postnatal bone acquisition, potentially due to an inability of osteoblasts to modify fuel selection. Intriguingly, suppression of fatty acid utilization by osteoblasts and osteocytes also resulted in the development of dyslipidemia and diet-dependent modifications in body composition. Taken together, these studies demonstrate a requirement for fatty acid oxidation during bone accrual and suggest a role for the skeleton in lipid homeostasis.

  6. Synthesis and evaluation of inhaled [11C]butane and intravenously injected [11C]acetone as potential radiotracers for studying inhalant abuse.

    Science.gov (United States)

    Gerasimov, Madina R; Ferrieri, Richard A; Pareto, Deborah; Logan, Jean; Alexoff, David; Ding, Yu-Shin

    2005-02-01

    The phenomenon of inhalant abuse is a growing problem in the US and many countries around the world. Yet, relatively little is known about the pharmacokinetic properties of inhalants that underlie their abuse potential. While the synthesis of 11C-labeled toluene, acetone and butane has been proposed in the literature, none of these compounds has been developed as radiotracers for PET studies. In the present report we extend our previous studies with [11C]toluene to include [11C]acetone and [11C]butane with the goal of comparing the pharmacokinetic profiles of these three volatile abused substances. Both [11C]toluene and [11C]acetone were administered intravenously and [11C]butane was administered via inhalation to anesthesized baboons. Rapid and efficient uptake of radiolabeled toluene and acetone into the brain was followed by fast clearance in the case of toluene and slower kinetics in the case of acetone. [11C]Butane was detected in the blood and brain following inhalation, but the levels of radioactivity in both tissues dropped to half of the maximal values over the period of less than a minute. To our knowledge, this is the first reported study of the in vivo brain pharmacokinetics of labeled acetone and butane in nonhuman primates. These data provide insight into the pharmacokinetic features possibly associated with the abuse liability of toluene, acetone and butane.

  7. Methodological considerations regarding the use of inorganic {sup 197}Hg(II) radiotracer to assess mercury methylation potential rates in lake sediment

    Energy Technology Data Exchange (ETDEWEB)

    Perez Catan, Soledad [Laboratorio de Analisis por Activacion Neutronica, Comision Nacional de Energia Atomica, Centro Atomico Bariloche, 8400 Bariloche (Argentina); Guevara, Sergio Ribeiro [Laboratorio de Analisis por Activacion Neutronica, Comision Nacional de Energia Atomica, Centro Atomico Bariloche, 8400 Bariloche (Argentina)], E-mail: ribeiro@cab.cnea.gov.ar; Marvin-DiPasquale, Mark [US Geological Survey, 345 Middlefield Rd./MS 480, Menlo Park, CA 94025 (United States); Magnavacca, Cecilia [Centro Atomico Ezeiza, Comision Nacional de Energia Atomica, Presbitero Gonzalez y Aragon No. 15, B1802AYA, Ezeiza, Buenos Aires (Argentina); Cohen, Isaac Marcos [Departamento de Ingenieria Quimica, Facultad Regional Buenos Aires, Universidad Tecnologica Nacional, Medrano 951 (C1179AAQ) Buenos Aires (Argentina); Arribere, Maria [Laboratorio de Analisis por Activacion Neutronica, Comision Nacional de Energia Atomica, Centro Atomico Bariloche, 8400 Bariloche (Argentina)

    2007-09-15

    Methodological considerations on the determination of benthic methyl-mercury (CH{sub 3}Hg) production potentials were investigated on lake sediment, using {sup 197}Hg radiotracer. Three methods to arrest bacterial activity were compared: flash freezing, thermal sterilization, and {gamma}-irradiation. Flash freezing showed similar CH{sub 3}Hg recoveries as thermal sterilization, which was both 50% higher than the recoveries obtained with {gamma}-ray irradiation. No additional radiolabel was recovered in kill-control samples after an additional 24 or 65 h of incubation, suggesting that all treatments were effective at arresting Hg(II)-methylating bacterial activity, and that the initial recoveries are likely due to non-methylated {sup 197}Hg(II) carry-over in the organic extraction and/or [{sup 197}Hg]CH{sub 3}Hg produced via abiotic reactions. Two CH{sub 3}Hg extraction methods from sediment were compared: (a) direct extraction into toluene after sediment leaching with CuSO{sub 4} and HCl and (b) the same extraction with an additional back-extraction step to thiosulphate. Similar information was obtained with both methods, but the low efficiency observed and the extra work associated with the back-extraction procedure represent significant disadvantages, even tough the direct extraction involves higher Hg(II) carry over.

  8. Methodological considerations regarding the use of inorganic 197Hg(II) radiotracer to assess mercury methylation potential rates in lake sediment

    Science.gov (United States)

    Perez, Catan S.; Guevara, S.R.; Marvin-DiPasquale, M.; Magnavacca, C.; Cohen, I.M.; Arribere, M.

    2007-01-01

    Methodological considerations on the determination of benthic methyl-mercury (CH3Hg) production potentials were investigated on lake sediment, using 197Hg radiotracer. Three methods to arrest bacterial activity were compared: flash freezing, thermal sterilization, and ??-irradiation. Flash freezing showed similar CH3Hg recoveries as thermal sterilization, which was both 50% higher than the recoveries obtained with ??-ray irradiation. No additional radiolabel was recovered in kill-control samples after an additional 24 or 65 h of incubation, suggesting that all treatments were effective at arresting Hg(II)-methylating bacterial activity, and that the initial recoveries are likely due to non-methylated 197Hg(II) carry-over in the organic extraction and/or [197Hg]CH3Hg produced via abiotic reactions. Two CH3Hg extraction methods from sediment were compared: (a) direct extraction into toluene after sediment leaching with CuSO4 and HCl and (b) the same extraction with an additional back-extraction step to thiosulphate. Similar information was obtained with both methods, but the low efficiency observed and the extra work associated with the back-extraction procedure represent significant disadvantages, even tough the direct extraction involves higher Hg(II) carry over. ?? 2007 Elsevier Ltd. All rights reserved.

  9. Radiosynthesis of 9{sup 9mT}c(CO){sup 3C}linafloxacin Dithiocarbamate and Its Biological Evaluation as a Potential staphylococcus aureus Infection Radiotracer

    Energy Technology Data Exchange (ETDEWEB)

    Shah, Syed Qaiser; Khan, Mohammad Rafiullah; Ali, Syed Mohammad [Univ. of Peshawar/Univ. of Engineering and Technology Peshawar, Peshawar (Pakistan)

    2011-12-15

    Clinafloxacin dithiocarbamate (CNND) was radiolabeled with technetium 99m ({sup 99mT}c) using [{sup 99mT}c(CO){sub 3}(H{sub 2O}){sub 3]}{sup +a}nd assessed for its radiochemical stability in saline and serum, its in vitro binding with methicillin resistant Staphylococcus aureus (MRSA) and biodistribution in female nude mice (FNM) artificially infected with live and heat killed MRSA. In normal saline (NS) the {sup 99mT}c(CO){sub 3c}linafloxacin dithiocarbamate ({sup 99mT}c(CO){sub 3C}NND) showed radiochemical stability with a maximum value of 99.10{+-}0.20% and remained stable up to 4 h (92.65{+-}0.18%). In human serum at 37.deg.C within 16 h of incubation, 14.85% side products as a result of de tagging developed. Incubation with MRSA gave saturated binding with a maximum value of 72.75{+-}1.20%. Almost six fold higher uptake was seen in the infected and normal muscle. The {sup 99mT}c (CO){sub 3C}NND complex showed a normal route of excretion from the body of the FNM model. The higher stability in NS, HS, saturated in vitro binding with a live strain of MRSA and six fold higher uptake in the target organ showed the {sup 99mT}c(CO){sub 3C}NND complex to be a potential MRSA infection radiotracer.

  10. Affinity of (nat/68)Ga-Labelled Curcumin and Curcuminoid Complexes for β-Amyloid Plaques: Towards the Development of New Metal-Curcumin Based Radiotracers.

    Science.gov (United States)

    Rubagotti, Sara; Croci, Stefania; Ferrari, Erika; Iori, Michele; Capponi, Pier C; Lorenzini, Luca; Calzà, Laura; Versari, Annibale; Asti, Mattia

    2016-09-06

    Curcumin derivatives labelled with fluorine-18 or technetium-99m have recently shown their potential as diagnostic tools for Alzheimer's disease. Nevertheless, no study by exploiting the labelling with gallium-68 has been performed so far, in spite of its suitable properties (positron emitter, generator produced radionuclide). Herein, an evaluation of the affinity for synthetic β-amyloid fibrils and for amyloid plaques of three (nat/68)Ga-labelled curcumin analogues, namely curcumin curcumin (CUR), bis-dehydroxy-curcumin (bDHC) and diacetyl-curcumin (DAC), was performed. Affinity and specificity were tested in vitro on amyloid synthetic fibrils by using gallium-68 labelled compounds. Post-mortem brain cryosections from Tg2576 mice were used for the ex vivo visualization of amyloid plaques. The affinity of (68)Ga(CUR)₂⁺, (68)Ga(DAC)₂⁺, and (68)Ga(bDHC)₂⁺ for synthetic β-amyloid fibrils was moderate and their uptake could be observed in vitro. On the other hand, amyloid plaques could not be visualized on brain sections of Tg2576 mice after injection, probably due to the low stability of the complexes in vivo and of a hampered passage through the blood-brain barrier. Like curcumin, all (nat/68)Ga-curcuminoid complexes maintain a high affinity for β-amyloid plaques. However, structural modifications are still needed to improve their applicability as radiotracers in vivo.

  11. Methodological considerations regarding the use of inorganic 197Hg(II) radiotracer to assess mercury methylation potential rates in lake sediment.

    Science.gov (United States)

    Pérez Catán, Soledad; Guevara, Sergio Ribeiro; Marvin-DiPasquale, Mark; Magnavacca, Cecilia; Cohen, Isaac Marcos; Arribere, María

    2007-09-01

    Methodological considerations on the determination of benthic methyl-mercury (CH(3)Hg) production potentials were investigated on lake sediment, using (197)Hg radiotracer. Three methods to arrest bacterial activity were compared: flash freezing, thermal sterilization, and gamma-irradiation. Flash freezing showed similar CH(3)Hg recoveries as thermal sterilization, which was both 50% higher than the recoveries obtained with gamma-ray irradiation. No additional radiolabel was recovered in kill-control samples after an additional 24 or 65 h of incubation, suggesting that all treatments were effective at arresting Hg(II)-methylating bacterial activity, and that the initial recoveries are likely due to non-methylated (197)Hg(II) carry-over in the organic extraction and/or [(197)Hg]CH(3)Hg produced via abiotic reactions. Two CH(3)Hg extraction methods from sediment were compared: (a) direct extraction into toluene after sediment leaching with CuSO(4) and HCl and (b) the same extraction with an additional back-extraction step to thiosulphate. Similar information was obtained with both methods, but the low efficiency observed and the extra work associated with the back-extraction procedure represent significant disadvantages, even tough the direct extraction involves higher Hg(II) carry over.

  12. A Mn-54 Radiotracer Study of Mn Isotope Solid-Liquid Exchange during Reductive Transformation of Vernadite (δ-MnO₂) by Aqueous Mn(II)

    Energy Technology Data Exchange (ETDEWEB)

    Elzinga, Evert J.; Kustka, Adam B. [Rutgers

    2015-04-09

    We employed Mn-54 radiotracers to characterize the extent and dynamics of Mn atom exchange between aqueous Mn(II) and vernadite (δ-Mn(IV)O2) at pH 7.5 under anoxic conditions. Exchange of Mn atoms between the solid and liquid phase is rapid, reaching dynamic equilibrium in 2–4 days. We propose that during the initial stages of reaction, Mn atom exchange occurs through consecutive comproportionation-disproportionation reactions where interfacial electron transfer from adsorbed Mn(II) to lattice Mn(IV) generates labile Mn(III) cations that rapidly disproportionate to reform aqueous Mn(II) and solid-phase Mn(IV). Following nucleation of Mn(III)OOH phases, additional exchange likely occurs through electron transfer from aqueous Mn(II) to solid-phase Mn(III). Our results provide evidence for the fast and extensive production of transient Mn(III) species at the vernadite surface upon contact of this substrate with dissolved Mn(II). We further show that HEPES buffer is a reductant of lattice Mn(IV) in the vernadite structure in our experiments. The methods and results presented here introduce application of Mn-54 tracers as a facile tool to further investigate the formation kinetics of labile Mn(III) surface species and their impacts on Mn-oxide structure and reactivity over a range of environmentally relevant geochemical conditions.

  13. Measurement of Bmax and Kd with the glycine transporter 1 radiotracer ¹⁸F-MK6577 using a novel multi-infusion paradigm.

    Science.gov (United States)

    Xia, Yan; Zheng, Ming-Qiang; Holden, Daniel; Lin, Shu-fei; Kapinos, Michael; Ropchan, Jim; Gallezot, Jean-Dominique; Huang, Yiyun; Carson, Richard E

    2015-12-01

    Glycine is a co-agonist of glutamate at the NMDA receptor. Glycine transporter 1 (GlyT1) inhibitors are reported to be potential therapeutic agents for schizophrenia. (18)F-MK6577 is a new positron emission tomography (PET) radiotracer useful for imaging brain GlyT1 and its occupancy in humans. We devised a novel multi-infusion paradigm of radiolabeled and unlabeled compound and an iterative linear/nonlinear alternating fitting method to allow for the determination of in vivo affinity (Kd) and target concentration (Bmax) images, constraining Kd to be uniform across the brain. This paradigm was tested with (18)F-MK6577 in baboons. Voxel-based analysis produced high quality Bmax images and reliable Kd estimates, and also suggested that the nondisplaceable distribution volume (VND) is not uniform throughout the brain. In vivo GlyT1 Kd was estimated to be 1.87 nmol/L for (18)F-MK6577, and the rank order of GlyT1 distribution measured in the baboon brain was: high in the brainstem (133 nmol/L), medium in the cerebellum (83 nmol/L), and low in the cortex (30 nmol/L). These in vivo Kd and Bmax values agreed well with those determined in vitro, thus validating our novel multi-infusion approach.

  14. Novel [99mTcN]2+ Labeled EGFR Inhibitors as Potential Radiotracers for Single Photon Emission Computed Tomography (SPECT Tumor Imaging

    Directory of Open Access Journals (Sweden)

    Mingxia Zhao

    2014-04-01

    Full Text Available The epidermal growth factor receptor (EGFR is overexpressed in many cancers, including breast, ovarian, endometrial and non-small cell lung cancer. An EGFR-specific imaging agent could facilitate clinical evaluation of primary tumors or metastases. To achieve this goal, 4-(2-aminoethylamino-6,7-dimethoxyquinazoline (ADMQ was synthesized based on a 4-aminoquinazoline core and then conjugated with N-mercapto- acetylglycine (MAG and N-mercaptoacetyltriglycine (MAG3, respectively, to give compounds 1 and 2. The final complexes [99mTcN]-1 and [99mTcN]-2 were successfully obtained with radiochemical purities of >99% and >98% as measured by radio-HPLC. No decomposition of the two complexes at room temperature was observed over a period of 2 h. Their partition coefficients indicated they were hydrophilic and the electrophoresis results showed they were negatively charged. Biodistribution in tumor-bearing mice demonstrated that the two new complexes showed tumor accumulation, high tumor-tomuscle (T/M ratios and fast clearance from blood and muscle. Between the two compounds, the 99mTcN-MAG3-ADMQ ([99mTcN]-2 showed the better characteristics, with the tumor/muscle and tumor/blood ratios reached 2.11 and 1.90 at 60 min post-injection, 4.20 and 1.10 at 120 min post-injection, suggesting it could be a promising radiotracer for SPECT tumor imaging.

  15. Patterns of Antenatal Care Seeking Behavior in South East Nigeria ...

    African Journals Online (AJOL)

    The effects of age, education, SES, and ANC seeking behavior were analyzed. ... KEY WORDS: Antenatal care, health seeking behavior, inequities, Nigeria, women of childbearing age ..... individual, family or community choice of health care.

  16. [Determinants of information-seeking about crime and crime prevention: information-seeking on the Internet].

    Science.gov (United States)

    Arai, Takashi; Fuji, Kei; Yoshida, Fujio

    2013-06-01

    This study explores determinants of information-seeking about crime and crime prevention on the Internet, including how it was influenced by personal conversations with others. An analysis of a web survey of mothers (N = 1,040) of 3-12 years old children in Japan indicated that many mothers briefly saw basic information about crime on the Internet, while only a few mothers sought further details. Structural equation modeling indicated the following results. Overall, an increased frequency of conversations about children's safety with family and friends made mothers realize their own responsibility for crime prevention. It also encouraged mothers to seek more information about crime prevention by increasing their willingness to cooperate with neighbors. However, when individuals' realization of responsibility for crime prevention strengthened their attitudes toward the responsibility of the police and government for crime problems, then these attitudes decreased mothers' information-seeking. Finally, while a heightened frequency of conversations about news contents directly increased information-seeking about crime, such conversations could indirectly weaken mothers' information-seeking when mothers emphasized the responsibility of the police and government.

  17. The Digital Astronaut Project Computational Bone Remodeling Model (Beta Version) Bone Summit Summary Report

    Science.gov (United States)

    Pennline, James; Mulugeta, Lealem

    2013-01-01

    Under the conditions of microgravity, astronauts lose bone mass at a rate of 1% to 2% a month, particularly in the lower extremities such as the proximal femur [1-3]. The most commonly used countermeasure against bone loss in microgravity has been prescribed exercise [4]. However, data has shown that existing exercise countermeasures are not as effective as desired for preventing bone loss in long duration, 4 to 6 months, spaceflight [1,3,5,6]. This spaceflight related bone loss may cause early onset of osteoporosis to place the astronauts at greater risk of fracture later in their lives. Consequently, NASA seeks to have improved understanding of the mechanisms of bone demineralization in microgravity in order to appropriately quantify this risk, and to establish appropriate countermeasures [7]. In this light, NASA's Digital Astronaut Project (DAP) is working with the NASA Bone Discipline Lead to implement well-validated computational models to help predict and assess bone loss during spaceflight, and enhance exercise countermeasure development. More specifically, computational modeling is proposed as a way to augment bone research and exercise countermeasure development to target weight-bearing skeletal sites that are most susceptible to bone loss in microgravity, and thus at higher risk for fracture. Given that hip fractures can be debilitating, the initial model development focused on the femoral neck. Future efforts will focus on including other key load bearing bone sites such as the greater trochanter, lower lumbar, proximal femur and calcaneus. The DAP has currently established an initial model (Beta Version) of bone loss due to skeletal unloading in femoral neck region. The model calculates changes in mineralized volume fraction of bone in this segment and relates it to changes in bone mineral density (vBMD) measured by Quantitative Computed Tomography (QCT). The model is governed by equations describing changes in bone volume fraction (BVF), and rates of

  18. What causes bone loss?

    Science.gov (United States)

    ... bone biology. In: Melmed S, Polonsky KS, Larsen PR, Kronenberg HM, eds. Williams Textbook of Endocrinology . 13th ed. Philadelphia, PA: Elsevier; 2016:chap 29. Maes C, Kronenberg HM. Bone development and remodeling. In: Jameson JL, ...

  19. Osteochondroma (Bone Tumor)

    Science.gov (United States)

    ... to be the most common benign bone tumor, accounting for 35% to 40% of all benign bone ... imaging scans. Doctors may also request computed tomography (CT) scans or magnetic resonance imaging (MRI) scans to ...

  20. What Is Bone Cancer?

    Science.gov (United States)

    ... arms, and jaw are most often affected. Giant cell tumor of bone: This type of primary bone ... Our Volunteers More ACS Sites Bookstore Shop Cancer Atlas Press Room Cancer Statistics Center Volunteer Learning Center ...

  1. Bone substitute biomaterials

    CERN Document Server

    Mallick, K

    2014-01-01

    Bone substitute biomaterials are fundamental to the biomedical sector, and have recently benefitted from extensive research and technological advances aimed at minimizing failure rates and reducing the need for further surgery. This book reviews these developments, with a particular focus on the desirable properties for bone substitute materials and their potential to encourage bone repair and regeneration. Part I covers the principles of bone substitute biomaterials for medical applications. One chapter reviews the quantification of bone mechanics at the whole-bone, micro-scale, and non-scale levels, while others discuss biomineralization, osteoductivization, materials to fill bone defects, and bioresorbable materials. Part II focuses on biomaterials as scaffolds and implants, including multi-functional scaffolds, bioceramics, and titanium-based foams. Finally, Part III reviews further materials with the potential to encourage bone repair and regeneration, including cartilage grafts, chitosan, inorganic poly...

  2. Bone mineral density test

    Science.gov (United States)

    BMD test; Bone density test; Bone densitometry; DEXA scan; DXA; Dual-energy x-ray absorptiometry; p-DEXA; Osteoporosis-BMD ... need to undress. This scan is the best test to predict your risk of fractures. Peripheral DEXA ( ...

  3. Evaluating information-seeking approaches to metacognition

    Science.gov (United States)

    Crystal, Jonathon D.; Foote, Allison L.

    2015-01-01

    Metacognition has been divided into information monitoring and control processes. Monitoring involves knowing that you know or do not know some information without taking corrective action. Control involves taking corrective action based on the knowledge that you know or do not know some information. In comparative metacognition, considerable attention has been paid toward critically assessing putative evidence for information monitoring in non-human animals. However, less attention has been paid toward critically evaluating evidence for control processes in animals. We briefly review a critique of information-monitoring in animals. Next, we apply these concepts to a number of studies that focus on information seeking in animals. The main type of evidence for control processes in animals come from tube tipping experiments. Before having the opportunity to search for the bait in these experiments, the subject sometimes observes opaque tubes being baited but is sometimes prevented from seeing the baiting. The observations that the subjects look more if baiting was not seen and are more accurate if baiting was seen have been taken as evidence for metacognition in information-seeking experiments. We propose simple alternative hypotheses that are sufficient to explain putative evidence for information seeking in animals without positing metacognition. The alternative explanation focuses on two relatively simple principles: First, an animal has a default "look before you go" response which supersedes random searches in space. Second, spatially guided behavior follows a default rule of "go where something good is." These principles can explain the results of tube tipping experiments without proposing metacognition. PMID:26779256

  4. Gracile bone dysplasias

    Energy Technology Data Exchange (ETDEWEB)

    Kozlowski, Kazimierz [Department of Medical Imaging, The Children' s Hospital at Westmead, Locked Bag 4001, Westmead 2145, NSW (Australia); Masel, John [Department of Radiology, Royal Children' s Hospital, Brisbane (Australia); Sillence, David O. [Department of Paediatrics and Child Health, The University of Sydney (Australia); Arbuckle, Susan [Department of Anatomical Pathology, The Children' s Hospital at Westmead, NSW (Australia); Juttnerova, Vera [Oddeleni Lekarske Genetiky, Hradec Kralove (Czech Republic)

    2002-09-01

    Gracile bone dysplasias constitute a group of disorders characterised by extremely slender bones with or without fractures. We report four newborns, two of whom showed multiple fractures. Two babies had osteocraniostenosis and one had features of oligohydramnios sequence. The diagnosis in the fourth newborn, which showed thin long bones and clavicles and extremely thin, poorly ossified ribs, is uncertain. Exact diagnosis of a gracile bone dysplasia is important for genetic counselling and medico-legal reasons. (orig.)

  5. Androgens and bone.

    Science.gov (United States)

    Vanderschueren, Dirk; Vandenput, Liesbeth; Boonen, Steven; Lindberg, Marie K; Bouillon, Roger; Ohlsson, Claes

    2004-06-01

    Loss of estrogens or androgens increases the rate of bone remodeling by removing restraining effects on osteoblastogenesis and osteoclastogenesis, and also causes a focal imbalance between resorption and formation by prolonging the lifespan of osteoclasts and shortening the lifespan of osteoblasts. Conversely, androgens, as well as estrogens, maintain cancellous bone mass and integrity, regardless of age or sex. Although androgens, via the androgen receptor (AR), and estrogens, via the estrogen receptors (ERs), can exert these effects, their relative contribution remains uncertain. Recent studies suggest that androgen action on cancellous bone depends on (local) aromatization of androgens into estrogens. However, at least in rodents, androgen action on cancellous bone can be directly mediated via AR activation, even in the absence of ERs. Androgens also increase cortical bone size via stimulation of both longitudinal and radial growth. First, androgens, like estrogens, have a biphasic effect on endochondral bone formation: at the start of puberty, sex steroids stimulate endochondral bone formation, whereas they induce epiphyseal closure at the end of puberty. Androgen action on the growth plate is, however, clearly mediated via aromatization in estrogens and interaction with ERalpha. Androgens increase radial growth, whereas estrogens decrease periosteal bone formation. This effect of androgens may be important because bone strength in males seems to be determined by relatively higher periosteal bone formation and, therefore, greater bone dimensions, relative to muscle mass at older age. Experiments in mice again suggest that both the AR and ERalpha pathways are involved in androgen action on radial bone growth. ERbeta may mediate growth-limiting effects of estrogens in the female but does not seem to be involved in the regulation of bone size in males. In conclusion, androgens may protect men against osteoporosis via maintenance of cancellous bone mass and

  6. Identifying Health-Seeking Behaviors: A Study of Adolescents.

    Science.gov (United States)

    Newell-Withrow, Cora

    1986-01-01

    Sought to determine how adolescents' (N=156) health-seeking behaviors, which include self-management and information-seeking behaviors, differ according to age, race, socioeconomic status, gender, and religion. Findings confirmed gender as a differentiating variable for performance of information-seeking behavior and found positive health…

  7. Seeking Help for Psychological Distress in Urban China

    Science.gov (United States)

    Chen, Juan

    2012-01-01

    Based on data gathered through a household survey of 1,474 urban residents in Beijing, this study examines Chinese help-seeking behaviors in times of psychological distress and perceived barriers to seeking professional help. The results demonstrate that most respondents rely on informal means of seeking help whereas mental health and medical…

  8. Seeking Help for Psychological Distress in Urban China

    Science.gov (United States)

    Chen, Juan

    2012-01-01

    Based on data gathered through a household survey of 1,474 urban residents in Beijing, this study examines Chinese help-seeking behaviors in times of psychological distress and perceived barriers to seeking professional help. The results demonstrate that most respondents rely on informal means of seeking help whereas mental health and medical…

  9. Enzymatic maceration of bone

    DEFF Research Database (Denmark)

    Uhre, Marie-Louise; Eriksen, Anne Marie; Simonsen, Kim Pilkjær;

    2015-01-01

    the bones. The DNA analysis showed that DNA was preserved on all the pieces of bones which were examined. Finally, the investigation suggests that enzyme maceration could be gentler on the bones, as the edges appeared less frayed. The enzyme maceration was also a quicker method; it took three hours compared...

  10. Psychiatric disorders of patients seeking obesity treatment

    Directory of Open Access Journals (Sweden)

    Lin Hung-Yen

    2013-01-01

    Full Text Available Abstract Background Obese and overweight people have a higher risk of both chronic physical illness and mental illness. Obesity is reported to be positively associated with psychiatric disorders, especially in people who seek obesity treatment. At the same time, obesity treatment may be influenced by psychological factors or personality characteristics. This study aimed to understand the prevalence of mental disorders among ethnic Chinese who sought obesity treatment. Methods Subjects were retrospectively recruited from an obesity treatment center in Taiwan. The obesity treatments included bariatric surgery and non-surgery treatment. All subjects underwent a standardized clinical evaluation with two questionnaires and a psychiatric referral when needed. The psychiatric diagnosis was made thorough psychiatric clinic interviews using the SCID. A total of 841 patients were recruited. We compared the difference in psychiatric disorder prevalence between patients with surgical and non-surgical treatment. Results Of the 841 patients, 42% had at least one psychiatric disorder. Mood disorders, anxiety disorders and eating disorders were the most prevalent categories of psychiatric disorders. Females had more mood disorders and eating disorders than males. The surgical group had more binge-eating disorder, adjustment disorder, and sleep disorders than the non-surgical group. Conclusion A high prevalence of psychiatric disorders was found among ethnic Chinese seeking obesity treatment. This is consistent with study results in the US and Europe.

  11. Adaptive interface for personalizing information seeking.

    Science.gov (United States)

    Narayanan, S; Koppaka, Lavanya; Edala, Narasimha; Loritz, Don; Daley, Raymond

    2004-12-01

    An adaptive interface autonomously adjusts its display and available actions to current goals and abilities of the user by assessing user status, system task, and the context. Knowledge content adaptability is needed for knowledge acquisition and refinement tasks. In the case of knowledge content adaptability, the requirements of interface design focus on the elicitation of information from the user and the refinement of information based on patterns of interaction. In such cases, the emphasis on adaptability is on facilitating information search and knowledge discovery. In this article, we present research on adaptive interfaces that facilitates personalized information seeking from a large data warehouse. The resulting proof-of-concept system, called source recommendation system (SRS), assists users in locating and navigating data sources in the repository. Based on the initial user query and an analysis of the content of the search results, the SRS system generates a profile of the user tailored to the individual's context during information seeking. The user profiles are refined successively and are used in progressively guiding the user to the appropriate set of sources within the knowledge base. The SRS system is implemented as an Internet browser plug-in to provide a seamless and unobtrusive, personalized experience to the users during the information search process. The rationale behind our approach, system design, empirical evaluation, and implications for research on adaptive interfaces are described in this paper.

  12. Memory Complaints Associated with Seeking Clinical Care

    Directory of Open Access Journals (Sweden)

    Carolina Pires

    2012-01-01

    Full Text Available Diagnosis of mild cognitive impairment relies on the presence of memory complaints. However, memory complaints are very frequent in healthy people. The objective of this study was to determine the severity and type of memory difficulties presented by elderly patients who seek for clinical help, as compared to the memory difficulties reported by subjects in the community. Assessment of subjective memory complaints was done with the subjective memory complaints scale (SMC. The mini-mental state examination was used for general cognitive evaluation and the geriatric depression scale for the assessment of depressive symptoms. Eight-hundred and seventy-one nondemented subjects older than 50 years were included. Participants in the clinical setting had a higher total SMC score (10.3±4.2 than those in the community (5.1±3.0. Item 3 of the SMC, Do you ever forget names of family members or friends? contributed significantly more to the variance of the total SMC score in the clinical sample (18% as compared to the community sample (11%. Forgetting names of family members or friends plays an important role in subjective memory complaints in the clinical setting. This symptom is possibly perceived as particularly worrisome and likely drives people to seek for clinical help.

  13. [Seeking tuberculosis care in Chiapas, Mexico].

    Science.gov (United States)

    Alvarez Gordillo, G C; Dorantes Jiménez, J E; Molina Rosales, D

    2001-05-01

    To analyze the process of seeking tuberculosis care and this process's impact on treatment adherence in the Mexican state of Chiapas, given that the two primary factors in successful tuberculosis (TB) control programs are early diagnosis and adherence to TB treatment. We conducted a qualitative study using group interviews with 11 groups of patients in three of the nine socioeconomic regions of the state of the Chiapas (Altos, Centro, and Fronteriza). The patients applied a variety of approaches in seeking care. The patients reported considerable delays in diagnosis due to problems that the patients themselves had and because of shortcomings in the care they received from the formal health care system. The treatment options that they followed were the result of their perceptions of the causes of TB and of the variety of traditional medical practices accepted in their communities. The lack of knowledge about TB encourages people to consider various alternatives for their care. Tuberculosis control in Chiapas requires an optimal utilization of the health services that exist in the state as well as a program of health education. TB control in Chiapas must take into account the social, cultural, and economic reality of the population.

  14. Integrating knowledge seeking into knowledge management models and frameworks

    Directory of Open Access Journals (Sweden)

    Francois Lottering

    2012-02-01

    Full Text Available Background: A striking feature of the knowledge management (KM literature is that the standard list of KM processes either subsumes or overlooks the process of knowledge seeking. Knowledge seeking is manifestly under-theorised, making the need to address this gap in KM theory and practice clear and urgent.Objectives: This article investigates the theoretical status of the knowledge-seeking process in extant KM models and frameworks. It also statistically describes knowledge seeking and knowledge sharing practices in a sample of South African companies. Using this data, it proposes a KM model based on knowledge seeking.Method: Knowledge seeking is traced in a number of KM models and frameworks with a specific focus on Han Lai and Margaret Graham’s adapted KM cycle model, which separates knowledge seeking from knowledge sharing. This empirical investigation used a questionnaire to examine knowledge seeking and knowledge sharing practices in a sample of South African companies.Results: This article critiqued and elaborated on the adapted KM cycle model of Lai and Graham. It identified some of the key features of knowledge seeking practices in the workplace. It showed that knowledge seeking and sharing are human-centric actions and that seeking knowledge uses trust and loyalty as its basis. It also showed that one cannot separate knowledge seeking from knowledge sharing.Conclusion: The knowledge seeking-based KM model elaborates on Lai and Graham’s model. It provides insight into how and where people seek and share knowledge in the workplace. The article concludes that it is necessary to cement the place of knowledge seeking in KM models as well as frameworks and suggests that organisations should apply its findings to improving their knowledge management strategies. 

  15. Oxytocin and bone

    Science.gov (United States)

    Sun, Li; Zaidi, Mone; Zallone, Alberta

    2014-01-01

    One of the most meaningful results recently achieved in bone research has been to reveal that the pituitary hormones have profound effect on bone, so that the pituitary-bone axis has become one of the major topics in skeletal physiology. Here, we discuss the relevant evidence about the posterior pituitary hormone oxytocin (OT), previously thought to exclusively regulate parturition and breastfeeding, which has recently been established to directly regulate bone mass. Both osteoblasts and osteoclasts express OT receptors (OTR), whose stimulation enhances bone mass. Consistent with this, mice deficient in OT or OTR display profoundly impaired bone formation. In contrast, bone resorption remains unaffected in OT deficiency because, even while OT stimulates the genesis of osteoclasts, it inhibits their resorptive function. Furthermore, in addition to its origin from the pituitary, OT is also produced by bone marrow osteoblasts acting as paracrine-autocrine regulator of bone formation modulated by estrogens. In turn, the power of estrogen to increase bone mass is OTR-dependent. Therefore, OTR−/− mice injected with 17β-estradiol do not show any effects on bone formation parameters, while the same treatment increases bone mass in wild-type mice. These findings together provide evidence for an anabolic action of OT in regulating bone mass and suggest that bone marrow OT may enhance the bone-forming action of estrogen through an autocrine circuit. This established new physiological role for OT in the maintenance of skeletal integrity further suggests the potential use of this hormone for the treatment of osteoporosis. PMID:25209411

  16. Factors associated with mobile health information seeking among Singaporean women.

    Science.gov (United States)

    Chang, Leanne; Chiuan Yen, Ching; Xue, Lishan; Choo Tai, Bee; Chuan Chan, Hock; Been-Lirn Duh, Henry; Choolani, Mahesh

    2017-01-01

    This study examined effects of age and social psychological factors on women's willingness to be mobile health information seekers. A national survey of 1,878 Singaporean women was conducted to obtain information on women's mobile phone usage, experiences of health information seeking, and appraisals of using mobile phones to seek health information. Results showed that young, middle-aged, and older women exhibited distinct mobile phone usage behaviors, health information-seeking patterns, and assessments of mobile health information seeking. Factors that accounted for their mobile information-seeking intention also varied. Data reported in this study provide insights into mobile health interventions in the future.

  17. Bone regeneration with cultured human bone grafts

    Energy Technology Data Exchange (ETDEWEB)

    Yoshikawa, T.; Nakajima, H. [Nara Medical Univ., Kashihara City (Japan). Dept. of Pathology; Nara Medical Univ., Kashihara City (Japan). Dept. of Orthopedic Surgery; Ohgushi, H.; Ueda, Y.; Takakura, Y. [Nara Medical Univ., Kashihara City (Japan). Dept. of Orthopedic Surgery; Uemura, T.; Tateishi, T. [National Inst. for Advanced Interdisciplinary Research (NAIR), Ibaraki (Japan). Tsukuba Research Center; Enomoto, Y.; Ichijima, K. [Nara Medical Univ., Kashihara City (Japan). Dept. of Pathology

    2001-07-01

    From 73 year old female patient, 3 ml of bone marrow was collected from the ilium. The marrow was cultured to concentrate and expand the marrow mesenchymal cells on a culture dish. The cultured cells were then subculturedeither on another culture dish or in porous areas of hydroxyapatite ceramics in the presence of dexamethasone and beta-glycerophosphate (osteo genic medium). The subculturedtissues on the dishes were analyzed by scanning electron microscopy (SEM), and subculturedtissues in the ceramics were implanted intraperitoneally into athymic nude mice. Vigorous growth of spindle-shaped cells and a marked formation of bone matrix beneath the cell layers was observed on the subculture dishes by SEM. The intraperitoneally implanted ceramics with cultured tissues revealed thick layer of lamellar bone together with active osteoblasts lining in many pore areas of the ceramics after 8 weeks. The in vitro bone formations on the culture dishes and in vivo bone formation in porous ceramics were detected. These results indicate that we can assemble an in vitro bone/ceramic construct, and due to the porous framework of the ceramic, the construct has osteogenic potential similar to that of autologous cancellous bone. A significant benefit of this method is that the construct can be made with only a small amount of aspirated marrow cells from aged patients with little host morbidity. (orig.)

  18. Cytology of Bone.

    Science.gov (United States)

    Barger, Anne M

    2017-01-01

    Cytology of bone is a useful diagnostic tool. Aspiration of lytic or proliferative lesions can assist with the diagnosis of inflammatory or neoplastic processes. Bacterial, fungal, and protozoal organisms can result in significant osteomyelitis, and these organisms can be identified on cytology. Neoplasms of bone including primary bone tumors such as osteosarcoma, chondrosarcoma, fibrosarcoma, synovial cell sarcoma, and histiocytic sarcoma and tumors of bone marrow including plasma cell neoplasia and lymphoma and metastatic neoplasia can result in significant bone lysis or proliferation and can be diagnosed effectively with cytology. Copyright © 2016 Elsevier Inc. All rights reserved.

  19. Reinvestigation of the synthesis and evaluation of [N-methyl-{sup 11}C]vorozole, a radiotracer targeting cytochrome P450 aromatase

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Sung Won [Medical Department, Brookhaven National Laboratory, Upton, NY 11973 (United States)], E-mail: swkim@bnl.gov; Biegon, Anat; Katsamanis, Zachary E. [Medical Department, Brookhaven National Laboratory, Upton, NY 11973 (United States); Ehrlich, Carolin W. [Johannes-Gutenberg Universitaet Mainz, Institut fuer Organische Chemie, Duesbergweg 10-14, Mainz (Germany); Hooker, Jacob M.; Shea, Colleen [Medical Department, Brookhaven National Laboratory, Upton, NY 11973 (United States); Muench, Lisa [National Institute on Alcoholism and Alcohol Abuse, Bethesda, MD (United States); Xu Youwen; King, Payton; Carter, Pauline; Alexoff, David L. [Medical Department, Brookhaven National Laboratory, Upton, NY 11973 (United States); Fowler, Joanna S. [Medical Department, Brookhaven National Laboratory, Upton, NY 11973 (United States); Department of Psychiatry, Mount Sinai School of Medicine, New York, NY (United States); Department of Chemistry, State University of New York at Stony Brook, Stony Brook, NY (United States)

    2009-04-15

    Introduction: We reinvestigated the synthesis of [N-methyl-{sup 11}C]vorozole, a radiotracer for aromatase, and discovered the presence of an N-methyl isomer which was not removed in the original purification method. Herein we report the preparation and positron emission tomography (PET) studies of pure [N-methyl-{sup 11}C]vorozole. Methods: Norvorozole was alkylated with [{sup 11}C]methyl iodide as previously described and also with unlabeled methyl iodide. A high-performance liquid chromatography (HPLC) method was developed to separate the regioisomers. Nuclear magnetic resonance (NMR) spectroscopy ({sup 13}C and 2D-nuclear Overhauser effect spectroscopy NMR) was used to identify and assign structures to the N-methylated products. Pure [N-methyl-{sup 11}C]vorozole and the contaminating isomer were compared by PET imaging in the baboon. Results: Methylation of norvorozole resulted in a mixture of isomers (1:1:1 ratio) based on new HPLC analysis using a pentafluorophenylpropyl bonded silica column, in which vorozole coeluted one of its isomers under the original HPLC conditions. Baseline separation of the three labeled isomers was achieved. The N-3 isomer was the contaminant of vorozole, thus correcting the original assignment of isomers. PET studies of pure [N-methyl-{sup 11}C]vorozole with and without the contaminating N-3 isomer revealed that only [N-methyl-{sup 11}C]vorozole binds to aromatase. [N-methyl-{sup 11}C]Vorozole accumulated in all brain regions with highest accumulation in the aromatase-rich amygdala and preoptic area. Accumulation was blocked with vorozole and letrozole consistent with reports of some level of aromatase in many brain regions. Conclusions: The discovery of a contaminating labeled isomer and the development of a method for isolating pure [N-methyl-{sup 11}C]vorozole combine to provide a new scientific tool for PET studies of the biology of aromatase and for drug research and development.

  20. Young learners' use of social media for information seeking

    DEFF Research Database (Denmark)

    Hyldegård, Jette Seiden

    2015-01-01

    information seeking activities, strategies and preferences can be identified when young learners use social media for information seeking in relation to course work and other study-related work tasks? 2) What motivations can be identified among young learners for using social media for information seeking....... The reported factors motivating information seeking were convenience and easy access to information, in addition to the content associated with specific social media types. Students’ use of social media for information seeking was associated primarily with their private information landscape. Contributions......Background. Increased use of social media for information seeking and learning calls for more research and knowledge of how these emerging technologies can support students’ learning. Objectives. The focus is on recent studies of young learners’ use of social media for information seeking...

  1. BONES WITH BIOCERAMICS

    Directory of Open Access Journals (Sweden)

    Wijianto Wijianto

    2017-01-01

    Full Text Available This paper discuss about ceramics in application as bone implant. Bioceramics for instance Hydroxyapatite, usually is abbreviated with HA or HAp, is a mineral that is very good physical properties as bone replacement in human body. To produce Hydroxyapatite, coating process is used which have good potential as they can exploit the biocompatible and bone bonding properties of the ceramic. There are many advantages and disadvantages of bioceramics as bone implant. Advantages of hydroxyapatite as bone implant are rapidly integrated into the human body, and is most interesting property that will bond to bone forming indistinguishable unions. On contrary, disadvantages of hydroxyapatite as bone implant are poor mechanical properties (in particular fatigue properties mean that hydroxyapatite cannot be used in bulk form for load bearing applications such as orthopaedics and poor adhesion between the calcium phosphate coating and the material implant will occur.

  2. Bone scintiscanning updated.

    Science.gov (United States)

    Lentle, B C; Russell, A S; Percy, J S; Scott, J R; Jackson, F I

    1976-03-01

    Use of modern materials and methods has given bone scintiscanning a larger role in clinical medicine, The safety and ready availability of newer agents have led to its greater use in investigating both benign and malignant disease of bone and joint. Present evidence suggests that abnormal accumulation of 99mTc-polyphosphate and its analogues results from ionic deposition at crystal surfaces in immature bone, this process being facilitated by an increase in bone vascularity. There is, also, a component of matrix localization. These factors are in keeping with the concept that abnormal scintiscan sites represent areas of increased osteoblastic activity, although this may be an oversimplification. Increasing evidence shows that the bone scintiscan is more sensitive than conventional radiography in detecting focal disease of bone, and its ability to reflect the immediate status of bone further complements radiographic findings. The main limitation of this method relates to nonspecificity of the results obtained.

  3. Bone disease in diabetes

    DEFF Research Database (Denmark)

    Shanbhogue, Vikram V.; Hansen, Stinus; Frost, Morten

    2017-01-01

    Type 1 and type 2 diabetes are generally accepted to be associated with increased bone fracture risk. However, the pathophysiological mechanisms of diabetic bone disease are poorly understood, and whether the associated increased skeletal fragility is a comorbidity or a complication of diabetes...... remains under debate. Although there is some indication of a direct deleterious effect of microangiopathy on bone, the evidence is open to question, and whether diabetic osteopathy can be classified as a chronic, microvascular complication of diabetes remains uncertain. Here, we review the current...... knowledge of potential contributory factors to diabetic bone disease, particularly the association between diabetic microangiopathy and bone mineral density, bone structure, and bone turnover. Additionally, we discuss and propose a pathophysiological model of the effects of diabetic microvascular disease...

  4. Seeking Safety and Empathy: Adolescent Health Seeking Behavior during Pregnancy and Early Motherhood in Central Uganda

    Science.gov (United States)

    Atuyambe, Lynn; Mirembe, Florence; Annika, Johansson; Kirumira, Edward K.; Faxelid, Elisabeth

    2009-01-01

    Purpose: To explore adolescent health seeking behavior during pregnancy and early motherhood in order to contribute to health policy formulation and improved access to health care. This will in long-term have an impact on the reduction of morbidity and mortality among adolescent mothers and their newborns. Methods: This was a qualitative study…

  5. Different Types of Sensation Seeking: A Person-Oriented Approach in Sensation-Seeking Research

    Science.gov (United States)

    Suranyi, Zsuzsanna; Hitchcock, David B.; Hittner, James B.; Vargha, Andras; Urban, Robert

    2013-01-01

    Previous research on sensation seeking (SS) was dominated by a variable-oriented approach indicating that SS level has a linear relation with a host of problem behaviors. Our aim was to provide a person-oriented methodology--a probabilistic clustering--that enables examination of both inter- and intra-individual differences in not only the level,…

  6. Diabetes, Biochemical Markers of Bone Turnover, Diabetes Control, and Bone

    OpenAIRE

    Starup-Linde, Jakob

    2013-01-01

    Diabetes mellitus is known to have late complications including micro vascular and macro vascular disease. This review focuses on another possible area of complication regarding diabetes; bone. Diabetes may affect bone via bone structure, bone density, and biochemical markers of bone turnover. The aim of the present review is to examine in vivo from humans on biochemical markers of bone turnover in diabetics compared to non-diabetics. Furthermore, the effect of glycemic control on bone marker...

  7. Improving radionuclide therapy in prostate cancer patients with metastatic bone pain

    OpenAIRE

    2009-01-01

    Bone seeking radiopharmaceuticals are indicated in cancer patients with multiple painful skeletal metastases. The majority of these patients are hormone-refractory prostate cancer patients in an advanced stage of their disease. Bone seeking radiopharmaceuticals relieve pain and improve the patients quality of life. The mostly used radiopharmaceuticals are 89SrCl2 (Metastron), 153Sm-EDTMP (Quadramet) and 186Re-HEDP. Differences between 89SrCl2, 153Sm-EDTMP and 186Re-HEDP were investigated. It ...

  8. Why breast cancer patients seek traditional healers.

    Science.gov (United States)

    Muhamad, Mazanah; Merriam, Sharan; Suhami, Norhasmilia

    2012-01-01

    Traditional healing is a common practice in low and middle income countries such as Malaysia. Eighty percent of Malaysians consult traditional healers or "bomoh" at some time in their life for health-related issues. The purpose of our study was to explore why breast cancer patients visit traditional healers. This is a qualitative study utilizing in-depth interviews with 11 cancer survivors who sought both traditional and Western medicine. The findings revealed the following reasons for which patients seek traditional healers: (1) recommendation from family and friends, (2) sanction from family, (3) perceived benefit and compatibility, (4) healer credibility, and (5) reservation with Western medicine and system delay. These factors work together and are strongly influenced by the Malaysian cultural context. The issue with the Western health system is common in a developing country with limited health facilities.

  9. Seeking for Simplicity in Complex Networks

    CERN Document Server

    Costa, L F

    2007-01-01

    Complex networks can be understood as graphs whose connectivity deviates from those of regular or near-regular graphs (which can be understood as `simple'). While a great deal of the attention so far foressen for complex networks has been duly driven by the above principle, in this work we take the dual approach and address the identification of simplicity, in the sense of regularity, in complex networks. The basic idea is to seek for subgraphs exhibiting small dispersion (e.g. standard deviation or entropy) of local measurements such as the node degree and clustering coefficient. Here we consider two types of subgraphs: (a) those defined by the progressive neighborhoods around each node and (b) subgraphs obtained from sets of nodes presenting similar local measurements. The former approach allows the assignment of a hierarchical regularity index to all network nodes, the latter paves the way for the identification of subgraphs (patches) in the original network, with nearly uniform connectivity. We illustrate...

  10. New wave seeks Indonesian coal mining concessions

    Energy Technology Data Exchange (ETDEWEB)

    Symon, A.

    1996-03-01

    A further wave of new mine exploration and development is on the horizon in Indonesia with 40 companies seeking major new concessions. Successful companies will enjoy a more attractive regulatory framework than their predecessors. The Indonesian Government is recasting the terms of the agreements under which it allows private domestic and foreign invested companies to operate large scale operations in order to encourage more investment in the industry. The Government`s intent to encourage expansion of the industry reflects looming pressure to provide sufficient coal to meet ambitious power plant expansion plans, while being able to maintain coal`s now important role as an export earner. In 1995, steam coal exports reached 40 billion tonnes, and contributed more than 1 billion dollars to Indonesia`s trade accounts. With Indonesia facing a widening current account deficit - combined with high foreign debt - the coal industry is playing a not insignificant role in helping to stabilise Indonesia`s external accounts. 1 tab.

  11. Why Breast Cancer Patients Seek Traditional Healers

    Directory of Open Access Journals (Sweden)

    Mazanah Muhamad

    2012-01-01

    Full Text Available Traditional healing is a common practice in low and middle income countries such as Malaysia. Eighty percent of Malaysians consult traditional healers or “bomoh” at some time in their life for health-related issues. The purpose of our study was to explore why breast cancer patients visit traditional healers. This is a qualitative study utilizing in-depth interviews with 11 cancer survivors who sought both traditional and Western medicine. The findings revealed the following reasons for which patients seek traditional healers: (1 recommendation from family and friends, (2 sanction from family, (3 perceived benefit and compatibility, (4 healer credibility, and (5 reservation with Western medicine and system delay. These factors work together and are strongly influenced by the Malaysian cultural context. The issue with the Western health system is common in a developing country with limited health facilities.

  12. Model-free stabilization by extremum seeking

    CERN Document Server

    Scheinker, Alexander

    2017-01-01

    With this brief, the authors present algorithms for model-free stabilization of unstable dynamic systems. An extremum-seeking algorithm assigns the role of a cost function to the dynamic system’s control Lyapunov function (clf) aiming at its minimization. The minimization of the clf drives the clf to zero and achieves asymptotic stabilization. This approach does not rely on, or require knowledge of, the system model. Instead, it employs periodic perturbation signals, along with the clf. The same effect is achieved as by using clf-based feedback laws that profit from modeling knowledge, but in a time-average sense. Rather than use integrals of the systems vector field, we employ Lie-bracket-based (i.e., derivative-based) averaging. The brief contains numerous examples and applications, including examples with unknown control directions and experiments with charged particle accelerators. It is intended for theoretical control engineers and mathematicians, and practitioners working in various industrial areas ...

  13. Seeking prospects for enhanced gas recovery

    Energy Technology Data Exchange (ETDEWEB)

    Doherty, M.G.; Randolph, P.L.

    1982-01-01

    As part of the Institute of Gas Technology's (IGT) ongoing research on unconventional natural gas sources, a methodology to locate gas wells that had watered-out under over-pressured conditions was developed and implemented. Each year several trillion cubic feet (Tcf) of gas are produced from reservoirs that are basically geopressured aquifers with large gas caps. As the gas is produced, the gas-water interface moves upward in the sandstone body trapping a portion of gas at the producing reservoir pressure. The methodology for identifying such formations consisted of a computer search of a large data base using a series of screening criteria to select or reject wells. The screening criteria consisted of depth cutoff, minimum production volume, minimum pressure gradient, and minimum water production. Wells chosen by the computer search were further screened manually to seek out those wells that exhibited rapid and large increases in water production with an associated quick decline in gas production indicating possible imbibition trapping of gas in the reservoir. The search was performed in an attempt to characterize the watered-out geopressured gas cap resource. Over 475 wells in the Gulf Coast area of Louisiana and Texas were identified as possible candidates representing an estimated potential of up to about 1 Tcf (2.83 x 10/sup 10/ m/sup 3/) of gas production through enhanced recovery operations. A process to determine the suitability of a watered-out geopressured gas cap reservoir for application of enhanced recovery is outlined. This paper addresses the identification of a potential gas source that is considered an unconventional resource. The methodology developed to identify watered-out geopressured gas cap wells can be utilized in seeking other types of watered-out gas reservoirs with the appropriate changes in the screening criteria. 12 references, 2 figures, 5 tables.

  14. Polymeric scaffolds as stem cell carriers in bone repair.

    Science.gov (United States)

    Rossi, Filippo; Santoro, Marco; Perale, Giuseppe

    2015-10-01

    Although bone has a high potential to regenerate itself after damage and injury, the efficacious repair of large bone defects resulting from resection, trauma or non-union fractures still requires the implantation of bone grafts. Materials science, in conjunction with biotechnology, can satisfy these needs by developing artificial bones, synthetic substitutes and organ implants. In particular, recent advances in polymer science have provided several innovations, underlying the increasing importance of macromolecules in this field. To address the increasing need for improved bone substitutes, tissue engineering seeks to create synthetic, three-dimensional scaffolds made from polymeric materials, incorporating stem cells and growth factors, to induce new bone tissue formation. Polymeric materials have shown a great affinity for cell transplantation and differentiation and, moreover, their structure can be tuned in order to maintain an adequate mechanical resistance and contemporarily be fully bioresorbable. This review emphasizes recent progress in polymer science that allows relaible polymeric scaffolds to be synthesized for stem cell growth in bone regeneration.

  15. Seeking safety and empathy: adolescent health seeking behavior during pregnancy and early motherhood in central Uganda.

    Science.gov (United States)

    Atuyambe, Lynn; Mirembe, Florence; Annika, Johansson; Kirumira, Edward K; Faxelid, Elisabeth

    2009-08-01

    To explore adolescent health seeking behavior during pregnancy and early motherhood in order to contribute to health policy formulation and improved access to health care. This will in long-term have an impact on the reduction of morbidity and mortality among adolescent mothers and their newborns. This was a qualitative study that employed focus group discussions (FGDs) among adolescent girls (10-19 years) and key informant (KI) interviews with health workers. Age for FGD participants ranged from 16 to 19 years. The FGD participants were recruited while seeking antenatal care for their first pregnancy or immunization service for their first child, not being older than 6 months. Six health facilities were selected. Key informants were purposefully selected on the basis of being in-charge of maternity units. Thirteen FGDs comprising of a total of 92 adolescent girls were conducted. The FGDs were held with homogeneously constituted categories; married pregnant adolescents (5), unmarried pregnant adolescents (3) and married or not married adolescents with children (5). Semi structured interviews were held with six KIs who were in-charge of maternity units of health facilities. Latent content analysis technique was used for data analysis. Two main themes emerged; 'feeling exposed and powerless', and 'seeking safety and empathy'. The categories identified in the first theme were "the dilemma of becoming an adolescent mother" and "lack of decision power". In the second theme the following categories were identified: "cultural practices and beliefs about birth", "expectations and experiences", "transport, a key determinant to health seeking", and "dealing with constraints". Adolescents felt exposed and powerless due to the dilemma of early motherhood and lack of decision making power. The adolescent mothers seemed to be in continuous quest for safety and empathy. In so doing they are part of cultural practices and beliefs about birth. They had expectations about the health

  16. Study of water flowrate using time transient and cross-correlation techniques with {sup 82}Br radiotracer; Estudo da vazao da agua utilizando as tecnicas de transiente de tempo e cross-correlacao com 82-Bromine como radiotracador

    Energy Technology Data Exchange (ETDEWEB)

    Salgado, William L., E-mail: william.otero@hotmail.com [Instituto Federal do Rio de Janeiro (IFRJ), Rio de Janeiro, RJ (Brazil); Brandao, Luiz E.B., E-mail: brandao@ien.gov.br [Instituto de Engenharia Nuclear (IEN/CNEN-RJ), Rio de Janeiro, RJ (Brazil)

    2013-07-01

    This paper aims to determinate the water flowrate using Time Transient and Cross-Correlation techniques. The detection system uses two NaI (T1) detectors adequately positioned on the outside of pipe and a gamma-ray source ({sup 82}Br radiotracer). The water flowrate measurements using Time Transient and Cross-Correlation techniques were compared to invasive conventional measurements of the flowrate previously installed in pipeline. Discrepancies between Time Transient and Cross-Correlation techniques flowmeter previously installed in pipeline. Discrepancies between Time Transient and Cross-Correlation techniques flowrate values were found to be less than 3% in relation to conventional ones. (author)

  17. Bone building with bortezomib

    Science.gov (United States)

    Roodman, G. David

    2008-01-01

    In this issue of the JCI, Mukherjee et al. report that bortezomib, a clinically available proteasome inhibitor active against myeloma, induces the differentiation of mesenchymal stem/progenitor cells (MSCs) — rather than mature osteoprogenitor cells — into osteoblasts, resulting in new bone formation (see the related article beginning on page 491). These results were observed when MSCs were implanted subcutaneously in mice or were used to treat a mouse model of postmenopausal bone loss. Others have reported that immunomodulatory drugs (e.g., thalidomide and lenalidomide), which are active against myeloma, also block the activity of bone-resorbing osteoclasts. These results reflect the utility of targeting endogenous MSCs for the purpose of tissue repair and suggest that combining different classes of agents that are antineoplastic and also inhibit bone destruction and increase bone formation should be very beneficial for myeloma patients suffering from severe bone disease. PMID:18219395

  18. Young learners' use of social media for information seeking

    DEFF Research Database (Denmark)

    Hyldegård, Jette Seiden

    2015-01-01

    . The challenges of using non-traditional social sources for information seeking identified in the studies raise questions of how teachers and information professionals can educate young learners to use social media competently as information seekers and authors of information.......Background. Increased use of social media for information seeking and learning calls for more research and knowledge of how these emerging technologies can support students’ learning. Objectives. The focus is on recent studies of young learners’ use of social media for information seeking...... information seeking activities, strategies and preferences can be identified when young learners use social media for information seeking in relation to course work and other study-related work tasks? 2) What motivations can be identified among young learners for using social media for information seeking...

  19. Young learners' use of social media for information seeking

    DEFF Research Database (Denmark)

    Hyldegård, Jette Seiden

    2015-01-01

    Background. Increased use of social media for information seeking and learning calls for more research and knowledge of how these emerging technologies can support students’ learning. Objectives. The focus is on recent studies of young learners’ use of social media for information seeking in an a....... The challenges of using non-traditional social sources for information seeking identified in the studies raise questions of how teachers and information professionals can educate young learners to use social media competently as information seekers and authors of information....... information seeking activities, strategies and preferences can be identified when young learners use social media for information seeking in relation to course work and other study-related work tasks? 2) What motivations can be identified among young learners for using social media for information seeking...

  20. Adrenal gland and bone.

    Science.gov (United States)

    Hardy, Rowan; Cooper, Mark S

    2010-11-01

    The adrenal gland synthesizes steroid hormones from the adrenal cortex and catecholamines from the adrenal medulla. Both cortisol and adrenal androgens can have powerful effects on bone. The overproduction of cortisol in Cushing's disease leads to a dramatic reduction in bone density and an increase risk of fracture. Overproduction of adrenal androgens in congenital adrenal hyperplasia (CAH) leads to marked changes in bone growth and development with early growth acceleration but ultimately a significant reduction in final adult height. The role of more physiological levels of glucocorticoids and androgens on bone metabolism is less clear. Cortisol levels measured in elderly individuals show a weak correlation with measures of bone density and change in bone density over time with a high cortisol level associated with lower bone density and more rapid bone loss. Cortisol levels and the dynamics of cortisol secretion change with age which could also explain some age related changes in bone physiology. It is also now clear that adrenal steroids can be metabolized within bone tissue itself. Local synthesis of cortisol within bone from its inactive precursor cortisone has been demonstrated and the amount of cortisol produced within osteoblasts appears to increase with age. With regard to adrenal androgens there is a dramatic reduction in levels with aging and several studies have examined the impact that restoration of these levels back to those seen in younger individuals has on bone health. Most of these studies show small positive effects in women, not men, but the skeletal sites where benefits are seen varies from study to study.

  1. Bone scanning in otolaryngology.

    Science.gov (United States)

    Noyek, A M

    1979-09-01

    Modern radionuclide bone scanning has introduced a new concept in physiologic and anatomic diagnostic imaging to general medicine. As otolaryngologists must diagnose and treat disease in relation to the bony and/or cartilaginous supporting structures of the neurocranium and upper airway, this modality should be included in the otolaryngologist's diagnostic armamentarium. It is the purpose of this manuscript to study the specific applications of bone scanning to our specialty at this time, based on clinical experience over the past three years. This thesis describes the development of bone scanning in general (history of nuclear medicine and nuclear physics; history of bone scanning in particular). General concepts in nuclear medicine are then presented; these include a discussion of nuclear semantics, principles of radioactive emmissions, the properties 99mTc as a radionuclide, and the tracer principle. On the basis of these general concepts, specific concepts in bone scanning are then brought forth. The physiology of bone and the action of the bone scan agents is presented. Further discussion considers the availability and production of the bone scan agent, patient factors, the gamma camera, the triphasic bone scan and the ultimate diagnostic principle of the bone scan. Clinical applications of bone scanning in otolaryngology are then presented in three sections. Proven areas of application include the evaluation of malignant tumors of the head and neck, the diagnosis of temporomandibular joint disorders, the diagnosis of facial fractures, the evaluation of osteomyelitis, nuclear medicine imaging of the larynx, and the assessment of systemic disease. Areas of adjunctive or supplementary value are also noted, such as diagnostic imaging of meningioma. Finally, areas of marginal value in the application of bone scanning are described.

  2. Rent-Seeking or Wealth-Creating: What to Choose?

    OpenAIRE

    Gillund, Nils Ove

    2012-01-01

    This thesis presents a quite extensive literature review on literature concerning entrepreneurship, allocation of talent and rent-seeking. There is also a presentation of two models, one model concerning the allocation of talent and rent seeking. The second, demonstrates how rent-seeking affects investments in an economy. In the empirical part of the thesis there is a re-estimation of the results found in Murphy, Shleifer and Vishny, The Allocation of Talent: Implications for Growth (1991...

  3. Olecranon bone graft: revisited.

    Science.gov (United States)

    Mersa, Berkan; Ozcelik, Ismail Bulent; Kabakas, Fatih; Sacak, Bulent; Aydin, Atakan

    2010-09-01

    Autogenous bone grafts are frequently in use in the field of reconstructive upper extremity surgery. Cancellous bone grafts are applied to traumatic osseous defects, nonunions, defects after the resection of benign bone tumors, arthrodesis, and osteotomy procedures. Cancellous bone grafts do not only have benefits such as rapid revascularization, but they also have mechanical advantages. Despite the proximity to the primary surgical field, cancellous olecranon grafts have not gained the popularity they deserve in the field of reconstructive hand surgery. In this study, the properties, advantages, and technical details of harvesting cancellous olecranon grafts are discussed.

  4. Blood: bone equilibrium

    Energy Technology Data Exchange (ETDEWEB)

    Neuman, M.W.

    1982-01-01

    The conundrum of blood undersaturation with respect to bone mineralization and its supersaturation with respect to bone's homeostatic function has acquired a new equation. On the supply side, Ca/sup 2 +/ is pumped in across bone cells to provide the needed Ca/sup 2 +/ x P/sub i/ for brushite precipitation. On the demand side, blood is in equilibrium with bone fluid, which is in equilibrium with a mineral more soluble than apatite. The function of potassium in this equation is yet to be found.

  5. Glutamate signalling in bone.

    Directory of Open Access Journals (Sweden)

    Karen eBrakspear

    2012-08-01

    Full Text Available Mechanical loading plays a key role in the physiology of bone, allowing bone to functionally adapt to its environment, however characterisation of the signalling events linking load to bone formation is incomplete. A screen for genes associated with mechanical load-induced bone formation identified the glutamate transporter GLAST, implicating the excitatory amino acid, glutamate, in the mechanoresponse. When an osteogenic load (10N, 10Hz was externally applied to the rat ulna, GLAST (EAAT1 mRNA, was significantly down-regulated in osteocytes in the loaded limb. Functional components from each stage of the glutamate signalling pathway have since been identified within bone, including proteins necessary for calcium-mediated glutamate exocytosis, receptors, transporters and signal propagation. Activation of ionotropic glutamate receptors has been shown to regulate the phenotype of osteoblasts and osteoclasts in vitro and bone mass in vivo. Furthermore, glutamatergic nerves have been identified in the vicinity of bone cells expressing glutamate receptors in vivo. However, it is not yet known how a glutamate signalling event is initiated in bone or its physiological significance. This review will examine the role of the glutamate signalling pathway in bone, with emphasis on the functions of glutamate transporters in osteoblasts.

  6. Hypercalciuric Bone Disease

    Science.gov (United States)

    Favus, Murray J.

    2008-09-01

    Hypercalciuria plays an important causal role in many patients with calcium oxalate (CaOx) stones. The source of the hypercalciuria includes increased intestinal Ca absorption and decreased renal tubule Ca reabsorption. In CaOx stone formers with idiopathic hypercalciuria (IH), Ca metabolic balance studies have revealed negative Ca balance and persistent hypercalciuria in the fasting state and during low dietary Ca intake. Bone resorption may also contribute to the high urine Ca excretion and increase the risk of bone loss. Indeed, low bone mass by DEXA scanning has been discovered in many IH patients. Thiazide diuretic agents reduce urine Ca excretion and may increase bone mineral density (BMD), thereby reducing fracture risk. Dietary Ca restriction that has been used unsuccessfully in the treatment of CaOx nephrolithiasis in the past may enhance negative Ca balance and accelerate bone loss. DEXA scans may demonstrate low BMD at the spine, hip, or forearm, with no predictable pattern. The unique pattern of bone histologic changes in IH differs from other causes of low DEXA bone density including postmenopausal osteoporosis, male hypogonadal osteoporosis, and glucocorticoid-induced osteoporosis. Hypercalciuria appears to play an important pathologic role in the development of low bone mass, and therefore correction of urine Ca losses should be a primary target for treatment of the bone disease accompanying IH.

  7. Foreign Entry Modes Under Institutional Pressures: The Impact of Strategic Resource Seeking and Market Seeking Strategies

    Directory of Open Access Journals (Sweden)

    Manuel Portugal Ferreira

    2008-01-01

    Full Text Available http://dx.doi.org/10.5007/2175-8069.2008v10n22p11Multinational corporations (MNCs are subject to the various dimensions of the external institutional environments. Institutional theory suggests that MNCs need to conform to the prevailing rules, norms and procedures of the locations where they operate in order to survive and grow. This means that MNCs need to develop the best possible configuration of strategy-structure for their worldwide operations. Previous research has noted that in these conditions firms may simply seek to follow a referent other. However, MNCs’ specific strategy for a focal foreign operation is likely to determine the entry mode for each host country. In certain circumstances it may be whether MNCs are pursuing a market-seeking strategy or a strategic resource seeking strategy that shapes the entry mode in face of the prevailing institutional pressures. We contribute to the understanding of entry modes into foreign markets as a reflection of a strategic choice that is bound by institutional constraints.

  8. Synthesis and preliminary evaluation of n.c.a. iodoquine: a novel radiotracer with high uptake in cells with high ALDH1 expression.

    Science.gov (United States)

    Chin, Bennett B; Hjelemand, Anita; Rich, Jeremy; Song, Haijing; Lascola, Christopher; Storms, Robert; McLendon, Roger; Reiman, Robert; Greer, Kim L; Metzler, Scott D; McDougald, Darryl; Dai, Diana; Vaidyanathan, Ganesan

    2012-01-01

    Chloroquine has demonstrated high affinity for aldehyde dehydrogenase 1A1 (ALDH1), an enzyme expressed in the highly tumorigenic CD133+ brain tumor initiating subpopulation. The purpose of this study is to report the novel synthesis of a chloroquine analogue, n.c.a. iodoquine, and the in vitro and in vivo uptake in cells with high ALDH1 content. Iodoquine was synthesized in novel no-carrier-added forms (n.c.a.) for both 125I and 123I. I25I IQ and 18F FDG cell uptake assays were performed in the L1210 and L1210cpa (cyclophosphamide resistant), A549, and MG456 glioblastoma cell lines. Uptake was expressed as a percent of the administered activity. 125I IQ biodistribution studies assessed organ uptake at 1, 4, and 24 hours after IV administration (n= 15 total; 5 mice/timepoint). Radiation dosimetry estimates were calculated using standard OLINDA/EXM software. In vivo imaging of 123I IQ uptake in MG456 glioblastoma mouse model (n=10) was performed with small animal high resolution micro-SPECT. Autoradiography and histology co-localized radiotracer and tumor biodistribution. Uptake in MG456 glioblastoma tumors was quantified with gamma counting. L1210 cpa (high ALDH1) showed significantly higher 125I IQ uptake compared to the parental L1210 (low ALDH1) for all time points through 4 hours (20.7% ± 1.4% versus 11.0% ± 0.5%; 21.3% ± 0.9% versus 11.0% ± 0.4%; 20.6% ± 0.7% versus 9.4% ± 0.3%; and 15.7% ± 0.7% versus 7.5% + 0.4% at 30 minutes, and 1, 2 and 4 hours, respectively; p 0.001 for all time points). The A549 lung cancer cell line also showed high IQ uptake through 4 hours. IQ normal biodistribution studies showed rapid renal excretion and very low normal background brain activity after IV administration. In vivo micro-SPECT images showed mild uptake in larger MG456 glioblastomas (n=6) as verified with autoradiography and histology. Gamma well counter uptake in large tumors was 2.3% ± 0.48% ID/g (n=5). Iodoquine localizes to cells with high ALDH1 content. Cell

  9. Systemic catechol-O-methyl transferase inhibition enables the D{sub 1} agonist radiotracer R-[{sup 11}C]SKF 82957

    Energy Technology Data Exchange (ETDEWEB)

    Palner, Mikael, E-mail: mikael.palner@nru.d [Neurobiology Research Unit, Rigshospitalet and University of Copenhagen, Copenhagen (Denmark); Center for Integrated Molecular Brain Imaging, Rigshospitalet (Denmark); McCormick, Patrick; Parkes, Jun [PET Center, Center for Addiction and Mental Health, Toronto, Ontario (Canada); Knudsen, Gitte M. [Neurobiology Research Unit, Rigshospitalet and University of Copenhagen, Copenhagen (Denmark); Center for Integrated Molecular Brain Imaging, Rigshospitalet (Denmark); Wilson, Alan A. [PET Center, Center for Addiction and Mental Health, Toronto, Ontario (Canada); Department of Psychiatry, University of Toronto, Toronto, Ontario (Canada)

    2010-10-15

    Introduction: R-[{sup 11}C]-SKF 82957 is a high-affinity and potent dopamine D{sub 1} receptor agonist radioligand, which gives rise to a brain-penetrant lipophilic metabolite. In this study, we demonstrate that systemic administration of catechol-O-methyl transferase (COMT) inhibitors blocks this metabolic pathway, facilitating the use of R-[{sup 11}C]-SKF 82957 to image the high-affinity state of the dopamine D{sub 1} receptor with PET. Methods: R-[{sup 11}C]SKF 82957 was administered to untreated and COMT inhibitor-treated conscious rats, and the radioactive metabolites present in the brain and plasma were quantified by HPLC. Under optimal conditions, cerebral uptake and dopamine D{sub 1} binding of R-[{sup 11}C]SKF 82957 were measured ex vivo. In addition, pharmacological challenges with the receptor antagonist SCH 23390, amphetamine, the dopamine reuptake inhibitor RTI-32 and the dopamine hydroxylase inhibitor {alpha}-methyl-p-tyrosine were performed to study the specificity and sensitivity of R-[{sup 11}C]-SKF 82957 dopamine D{sub 1} binding in COMT-inhibited animals. Results: Treatment with the COMT inhibitor tolcapone was associated with a dose-dependent (EC{sub 90} 5.3{+-}4.3 mg/kg) reduction in the lipophilic metabolite. Tolcapone treatment (20 mg/kg) also resulted in a significant increase in the striatum/cerebellum ratio of R-[{sup 11}C]SKF 82957, from 15 (controls) to 24. Treatment with the dopamine D{sub 1} antagonist SCH 23390 reduced the striatal binding to the levels of the cerebellum, demonstrating a high specificity and selectivity of R-[{sup 11}C]SKF 82957 binding. Conclusions: Pre-treatment with the COMT inhibitor tolcapone inhibits formation of an interfering metabolite of R-[{sup 11}C]SKF 82957. Under such conditions, R-[{sup 11}C]SKF 82957 demonstrates high potential as the first agonist radiotracer for imaging the dopamine D{sub 1} receptor by PET.

  10. Evaluation of two novel {sup 64}Cu-labeled RGD peptide radiotracers for enhanced PET imaging of tumor integrin α{sub v}β{sub 3}

    Energy Technology Data Exchange (ETDEWEB)

    Hernandez, Reinier; Graves, Stephen A.; Nickles, Robert J. [University of Wisconsin, Department of Medical Physics, Madison, WI (United States); Czerwinski, Andrzej; Valenzuela, Francisco [Peptides International, Inc., Louisville, KY (United States); Chakravarty, Rubel; Yang, Yunan; England, Christopher G. [University of Wisconsin, Department of Radiology, Madison, WI (United States); Cai, Weibo [University of Wisconsin, Department of Medical Physics, Madison, WI (United States); University of Wisconsin, Department of Radiology, Madison, WI (United States); University of Wisconsin Carbone Cancer Center, Madison, WI (United States)

    2015-11-15

    Our goal was to demonstrate that suitably derivatized monomeric RGD peptide-based PET tracers, targeting integrin α{sub v}β{sub 3}, may offer advantages in image contrast, time for imaging, and low uptake in nontarget tissues. Two cyclic RGDfK derivatives, (PEG){sub 2}-c(RGDfK) and PEG{sub 4}-SAA{sub 4}-c(RGDfK), were constructed and conjugated to NOTA for {sup 64}Cu labeling. Their integrin α{sub v}β{sub 3}-binding properties were determined via a competitive cell binding assay. Mice bearing U87MG tumors were intravenously injected with each of the {sup 64}Cu-labeled peptides, and PET scans were acquired during the first 30 min, and 2 and 4 h after injection. Blocking and ex vivo biodistribution studies were carried out to validate the PET data and confirm the specificity of the tracers. The IC{sub 50} values of NOTA-(PEG){sub 2}-c(RGDfK) and NOTA-PEG{sub 4}-SAA{sub 4}-c(RGDfK) were 444 ± 41 nM and 288 ± 66 nM, respectively. Dynamic PET data of {sup 64}Cu-NOTA-(PEG){sub 2}-c(RGDfK) and {sup 64}Cu-NOTA-PEG{sub 4}-SAA{sub 4}-c(RGDfK) showed similar circulation t{sub 1/2} and peak tumor uptake of about 4 %ID/g for both tracers. Due to its marked hydrophilicity, {sup 64}Cu-NOTA-PEG{sub 4}-SAA{sub 4}-c(RGDfK) provided faster clearance from tumor and normal tissues yet maintained excellent tumor-to-background ratios. Static PET scans at later time-points corroborated the enhanced excretion of the tracer, especially from abdominal organs. Ex vivo biodistribution and receptor blocking studies confirmed the accuracy of the PET data and the integrin α{sub v}β{sub 3}-specificity of the peptides. Our two novel RGD-based radiotracers with optimized pharmacokinetic properties allowed fast, high-contrast PET imaging of tumor-associated integrin α{sub v}β{sub 3}. These tracers may facilitate the imaging of abdominal malignancies, normally precluded by high background uptake. (orig.)

  11. Women's rights, domestic violence, and recourse seeking in rural Bangladesh.

    Science.gov (United States)

    Schuler, Sidney Ruth; Bates, Lisa M; Islam, Farzana

    2008-03-01

    This article seeks to deepen understanding of the reasons that abused women in a resource-poor rural setting seek recourse so seldom and with so little success. Data from in-depth interviews and group discussions are used to explore the range of responses to domestic violence and to examine barriers to recourse seeking. Findings illustrate how the combination of poverty and gender inequality, inequities in the legal framework, and patriarchal attitudes and corruption in both formal and informal institutions at the local level discourage abused women from seeking recourse and decrease the likelihood of a favorable outcome when they do.

  12. Edward W. Soja. Seeking Spatial Justice

    Directory of Open Access Journals (Sweden)

    Navarrete Cardona Steven

    2012-12-01

    Full Text Available La urbanización ha tomado un curso dramático a nivel mundial durante los últimos veinte años. El crecimiento demográfico, el acelerado cambio tecnológico, los amplios flujos migratorios desde América Latina, Asia y África, hacia Europa y Estados Unidos, así como la división internacional del trabajo y el auge de las comunidades virtuales repercuten no solo de manera visible en la organización espacial urbana del mundo entero, sino también en la reestructuración epistemológica y en los cambios, que, a su vez, tiene al interior la geografía como ciencia. La obra de Edward Soja, Seeking Spatial Justice, aparece en momentos en que la cuestión urbana se convierte en un tema de investigación apremiante en las agendas de diversos investigadores del mundo que tratan de dar cuenta de los profundos cambios que las ciudades enfrentan en los últimos años.

  13. Physical activity information seeking and advertising recall.

    Science.gov (United States)

    Berry, Tanya R; Spence, John C; Plotnikoff, Ronald C; Bauman, Adrian

    2011-04-01

    The purposes of this research were to examine the characteristics of those who look for physical activity-related information, where they find it, and to examine what types of physical activity-related advertisements are recalled (i.e., publicly funded or commercial). These purposes were tested using secondary data analyses from two population health surveys. Results from the first survey (n=1211) showed gender, age, education, and activity-level differences in who is more likely to search for physical activity-related information. Adding the goal of being active into the model made age and activity level no longer significant but gender and education remained significant factors. The Internet was the most often cited source of physical activity information. The second survey (n=1600) showed that adults 55 years of age or older and participants with the least amount of education were more than twice as likely to name commercial advertisements than were participants aged 18-54 years or those with more education. These results help further our understanding of how publicly funded promotional campaigns fare against commercial advertising and also highlight the need to understand physical activity information-seeking behavior on the Internet and its implications for health promotion.

  14. Social seeking declines in young adolescents.

    Science.gov (United States)

    Dubey, Indu; Ropar, Danielle; Hamilton, Antonia F de C

    2017-08-01

    The desire to engage with others is an important motivational force throughout our lifespan. It is known that social behaviour and preferences change from childhood to adulthood, but whether this change is linked with any changes in social motivation is not known. We evaluated 255 typically developing participants from ages 4-20 years on a behavioural paradigm 'Choose a Movie' (CAM). On every trial, participants had a choice between viewing social or non-social movies presented with different levels of effort (key presses/screen touch required). Hence, participants chose not only the movie they would watch but also how much effort they would make. The difference between the effort levels of the chosen and not chosen stimuli helps in quantifying the motivation to seek it. This task could be used with all the age groups with minimal adaptations, allowing comparison between the groups. Results showed that children (4-8 years), older adolescents (12-16 years) and young adults (17-20 years) made more effort to look at social movies. Counterintuitively, this preference was not seen in young adolescents (around 9-12 years), giving a U-shaped developmental trajectory over the population. We present the first evidence for non-monotonic developmental change in social motivation in typical participants.

  15. Radiotracer Imaging of Sediment Columns

    Science.gov (United States)

    Moses, W. W.; O'Neil, J. P.; Boutchko, R.; Nico, P. S.; Druhan, J. L.; Vandehey, N. T.

    2010-12-01

    Nuclear medical PET and SPECT cameras routinely image radioactivity concentration of gamma ray emitting isotopes (PET - 511 keV; SPECT - 75-300 keV). We have used nuclear medical imaging technology to study contaminant transport in sediment columns. Specifically, we use Tc-99m (T1/2 = 6 h, Eγ = 140 keV) and a SPECT camera to image the bacteria mediated reduction of pertechnetate, [Tc(VII)O4]- + Fe(II) → Tc(IV)O2 + Fe(III). A 45 mL bolus of Tc-99m (32 mCi) labeled sodium pertechnetate was infused into a column (35cm x 10cm Ø) containing uranium-contaminated subsurface sediment from the Rifle, CO site. A flow rate of 1.25 ml/min of artificial groundwater was maintained in the column. Using a GE Millennium VG camera, we imaged the column for 12 hours, acquiring 44 frames. As the microbes in the sediment were inactive, we expected most of the iron to be Fe(III). The images were consistent with this hypothesis, and the Tc-99m pertechnetate acted like a conservative tracer. Virtually no binding of the Tc-99m was observed, and while the bolus of activity propagated fairly uniformly through the column, some inhomogeneity attributed to sediment packing was observed. We expect that after augmentation by acetate, the bacteria will metabolically reduce Fe(III) to Fe(II), leading to significant Tc-99m binding. Imaging sediment columns using nuclear medicine techniques has many attractive features. Trace quantities of the radiolabeled compounds are used (micro- to nano- molar) and the half-lives of many of these tracers are short (Image of Tc-99m distribution in a column containing Rifle sediment at four times.

  16. Bone Marrow Aspiration and Biopsy

    Science.gov (United States)

    ... Advertising & Sponsorship: Policy | Opportunities Bone Marrow Aspiration and Biopsy Share this page: Was this page helpful? Also ... Examination Formal name: Bone Marrow Aspiration; Bone Marrow Biopsy Related tests: Complete Blood Count ; WBC Differential ; Reticulocyte ...

  17. Bone X-Ray (Radiography)

    Medline Plus

    Full Text Available ... the body. X-rays are the oldest and most frequently used form of medical imaging. A bone ... bones. top of page How should I prepare? Most bone x-rays require no special preparation. You ...

  18. Bone X-Ray (Radiography)

    Medline Plus

    Full Text Available ... ionizing radiation to produce pictures of any bone in the body. It is commonly used to diagnose ... bone x-ray makes images of any bone in the body, including the hand, wrist, arm, elbow, ...

  19. Children's bone health

    NARCIS (Netherlands)

    I.M. van der Sluis (Inge)

    2002-01-01

    textabstractThe thesis can be divided in two main parts. In the first part (Chapter 2 to 5) bone mineral density, bone metabolism and body composition in healthy children and young adults have been evaluated, while in the second part (Chapter 6 to 10) these issues were studied in children with vario

  20. BONES, TEACHER'S GUIDE.

    Science.gov (United States)

    Elementary Science Study, Newton, MA.

    THIS GUIDE WAS DEVELOPED FOR USE WITH THE ELEMENTARY SCIENCE STUDY UNIT ON "BONES.""BONES" HAS BEEN TAUGHT IN THE FOURTH GRADE AND REQUIRES FROM 10 TO 25 LESSONS, DEPENDING ON THE NUMBER OF ACTIVITIES USED. THE GUIDE DOES NOT PROVIDE DETAILED INSTRUCTION FOR CONDUCTING CLASSES, BUT RATHER SOME POSSIBLE ACTIVITIES, AND LEAVES THE DAY-TO-DAY…

  1. Pseudoanaplastic tumors of bone

    Energy Technology Data Exchange (ETDEWEB)

    Bahk, Won-Jong [Uijongbu St. Mary Hospital, The Catholic University of Korea, Department of Orthopaedic Surgery, Gyunggido, 480-821 (Korea); Mirra, Joseph M. [Orthopaedic Hospital, Orthopedic Oncology, Los Angeles, California (United States)

    2004-11-01

    To discuss the concept of pseudoanaplastic tumors of bone, which pathologically show hyperchromatism and marked pleomorphism with quite enlarged, pleomorphic nuclei, but with no to extremely rare, typical mitoses, and to propose guidelines for their diagnosis. From a database of 4,262 bone tumors covering from 1971 to 2001, 15 cases of pseudoanaplastic bone tumors (0.35% of total) were retrieved for clinical, radiographic and pathologic review. Postoperative follow-up after surgical treatment was at least 3 years and a maximum of 7 years. There were eight male and seven female patients. Their ages ranged from 10 to 64 years with average of 29.7 years. Pathologic diagnoses of pseudoanaplastic variants of benign bone tumors included: osteoblastoma (4 cases), giant cell tumor (4 cases), chondromyxoid fibroma (3 cases), fibrous dysplasia (2 cases), fibrous cortical defect (1 case) and aneurysmal bone cyst (1 case). Radiography of all cases showed features of a benign bone lesion. Six cases, one case each of osteoblastoma, fibrous dysplasia, aneurysmal bone cyst, chondromyxoid fibroma, giant cell tumor and osteoblastoma, were initially misdiagnosed as osteosarcoma. The remaining cases were referred for a second opinion to rule out sarcoma. Despite the presence of significant cytologic aberrations, none of our cases showed malignant behavior following simple curettage or removal of bony lesions. Our observation justifies the concept of pseudoanaplasia in some benign bone tumors as in benign soft tissue tumors, especially in their late evolutionary stage when bizarre cytologic alterations strongly mimic a sarcoma. (orig.)

  2. Biodegradable synthetic bone composites

    Science.gov (United States)

    Liu, Gao; Zhao, Dacheng; Saiz, Eduardo; Tomsia, Antoni P.

    2013-01-01

    The invention provides for a biodegradable synthetic bone composition comprising a biodegradable hydrogel polymer scaffold comprising a plurality of hydrolytically unstable linkages, and an inorganic component; such as a biodegradable poly(hydroxyethylmethacrylate)/hydroxyapatite (pHEMA/HA) hydrogel composite possessing mineral content approximately that of human bone.

  3. Osteotransductive bone cements.

    Science.gov (United States)

    Driessens, F C; Planell, J A; Boltong, M G; Khairoun, I; Ginebra, M P

    1998-01-01

    Calcium phosphate bone cements (CPBCs) are osteotransductive, i.e. after implantation in bone they are transformed into new bone tissue. Furthermore, due to the fact that they are mouldable, their osteointegration is immediate. Their chemistry has been established previously. Some CPBCs contain amorphous calcium phosphate (ACP) and set by a sol-gel transition. The others are crystalline and can give as the reaction product dicalcium phosphate dihydrate (DCPD), calcium-deficient hydroxyapatite (CDHA), carbonated apatite (CA) or hydroxyapatite (HA). Mixed-type gypsum-DCPD cements are also described. In vivo rates of osteotransduction vary as follows: gypsum-DCPD > DCPD > CDHA approximately CA > HA. The osteotransduction of CDHA-type cements may be increased by adding dicalcium phosphate anhydrous (DCP) and/or CaCO3 to the cement powder. CPBCs can be used for healing of bone defects, bone augmentation and bone reconstruction. Incorporation of drugs like antibiotics and bone morphogenetic protein is envisaged. Load-bearing applications are allowed for CHDA-type, CA-type and HA-type CPBCs as they have a higher compressive strength than human trabecular bone (10 MPa).

  4. Children's bone health

    NARCIS (Netherlands)

    I.M. van der Sluis (Inge)

    2002-01-01

    textabstractThe thesis can be divided in two main parts. In the first part (Chapter 2 to 5) bone mineral density, bone metabolism and body composition in healthy children and young adults have been evaluated, while in the second part (Chapter 6 to 10) these issues were studied in children

  5. Bone Loss in IBD

    Science.gov (United States)

    ... may notice some back pain or change in posture, this disorder generally produces no symptoms until the bone becomes so weakened that it breaks. Bone fractures due to osteoporosis most often occur in the spine and hips. This is why screening tests for ...

  6. Nanomaterials promise better bone repair

    OpenAIRE

    Qifei Wang; Jianhua Yan; Junlin Yang; Bingyun Li

    2016-01-01

    Nanomaterials mimicking the nano-features of bones and offering unique smart functions are promising for better bone fracture repair. This review provides an overview of the current state-of-the-art research in developing and using nanomaterials for better bone fracture repair. This review begins with a brief introduction of bone fracture repair processes, then discusses the importance of vascularization, the role of growth factors in bone fracture repair, and the failure of bone fracture rep...

  7. Estimative of dilution factor for radioactive liquid effluents employing the H-3 and Cs-137 radiotracers present as pollutant; Estimativa do fator de diluicao para efluentes radioativos liquidos empregando os radiotracadores H-3 e Cs-137 presentes como poluentes

    Energy Technology Data Exchange (ETDEWEB)

    Nisti, Marcelo Bessa; Santos, Adir Janete Godoy dos, E-mail: mbnisti@ipen.b [Instituto de Pesquisas Energeticas e Nucleares (IPEN/CNEN-SP), Sao Paulo, SP (Brazil)

    2011-07-01

    It was estimated the dilution factor for liquid effluents at the discharge points of the IPEN, Sao Paulo, Brazil, employing as radiotracers the radioisotope routinely liberated for the sewage of 'Cidade Universitaria Armando de Salles Oliveira' - CUASO {sup 3}H and {sup 137}Cs, not generating either monetary or environmental cost associated to the estimation. The {sup 137}Cs was determined by gamma spectrometry and the {sup 3}H was determined liquid phase scintillation. The results showed that the dilution factor varied according to the employed radiotracer in a crescent order of {sup 3}H and {sup 137}Cs according to the characteristics of each element. The average of dilution factors obtained at the first and second liberation day were 4.3 and 7.4 respectively for the {sup 3}H and 6.2 and 13.9 for the {sup 137}Cs. The ratio of dilution factors of calculated {sup 3}H and {sup 137}Cs were coherent with the ratio verified at the twelve hydrometers distributed by the IPEN campus. The dilution factors were estimated in operational and laboratory study, in a single controlled discharge of the TR1 tank

  8. Colon visualization on (99m)Tc-HDP whole-body bone scan due to sigmoid colon cancer-related enterovesical fistula.

    Science.gov (United States)

    Kim, Sung Hoon; Song, Bong-Il; Won, Kyoung Sook

    2015-01-01

    An abnormally increased uptake of the bone-seeking agent is rarely observed in structures other than the bone and urinary track on bone scintigraphy. The general etiologies of soft tissue uptake can be explained by heterotopic ossification or dystrophic and metastatic calcification. We report a case of serendipitous visualization of the entire colon on bone scintigraphy. Diffuse colonic uptake was detected on the whole-body bone scan in a patient with biopsy-proven sigmoid colon cancer. Additional imaging studies clearly showed direct bladder invasion of the sigmoid colon cancer. Imaging findings with a brief review of the literature are presented in this article.

  9. 7 CFR 22.309 - Seeking Federal review.

    Science.gov (United States)

    2010-01-01

    ... 7 Agriculture 1 2010-01-01 2010-01-01 false Seeking Federal review. 22.309 Section 22.309 Agriculture Office of the Secretary of Agriculture RURAL DEVELOPMENT COORDINATION Roles and Responsibilities of State Governments § 22.309 Seeking Federal review. States may, if they elect, submit multicounty...

  10. Spatial factors as contextual qualifiers of information seeking

    Directory of Open Access Journals (Sweden)

    R. Savolainen

    2006-01-01

    Full Text Available Introduction. This paper investigates the ways in which spatial factors have been approached in information seeking studies. The main attention was focused on studies discussing information seeking on the level of source selection and use. Method. Conceptual analysis of about 100 articles and books thematizing spatial issues of information seeking. Due to research economy, the main attention was paid to studies on everyday life information seeking. Results. Three major viewpoints were identified with regard to the degree of objectivity of spatial factors. The objectifying approach conceives of spatial factors as external and entity-like qualifiers that primarly constrain information seeking. The realistic-pragmatic approach emphasizes the ways in which the availabilty of information sources in different places such as daily work environments orient information seeking. The perspectivist approach focuses on how people subjectively assess the significance of various sources by means of spatial constructs such as information horizons. Conclusion. Spatial factors are centrally important contextual qualifiers of information seeking. There is a need to further explore the potential of the above viewpoints by relating the spatial and temporal factors of information seeking.

  11. The Information Seeking and Use Behaviors of Retired Investors

    Science.gov (United States)

    O'Connor, Lisa G.

    2013-01-01

    This exploratory study examines the information seeking and use behaviors of a group of US retired or near-retirement investors from everyday life information seeking and serious leisure perspectives. Although primarily qualitative, it also collects and analyzes quantitative data to describe retired investors' information preferences and use.…

  12. Social Support Seeking and Early Adolescent Depression and Anxiety Symptoms

    Science.gov (United States)

    Vélez, Clorinda E.; Krause, Elizabeth D.; McKinnon, Allison; Brunwasser, Steven M.; Freres, Derek R.; Abenavoli, Rachel M.; Gillham, Jane E.

    2016-01-01

    This study examined how social support seeking and rumination interacted to predict depression and anxiety symptoms 6 months later in early adolescents (N = 118; 11-14 years at baseline). We expected social support seeking would be more helpful for adolescents engaging in low rather than high levels of rumination. Adolescents self-reported on all…

  13. Help-Seeking Behavior among Black Males. Final Report.

    Science.gov (United States)

    Gary, Lawrence E.; And Others

    This study concerns the help-seeking behavior of black males as it relates to mental health and attempts to identify the day-to-day concerns and problems of black males, describe their help seeking patterns, and make suggestions for future research and policy development to improve black males' mental health. The sample was 142 black males, ages…

  14. Reputation-Seeking by a Government Agency in Europe

    DEFF Research Database (Denmark)

    Bækkeskov, Erik

    2017-01-01

    Reputation-seeking can explain some decisions of U.S. federal agencies. However, it has remained unclear whether it could be used in the European context where agencies have proliferated in national and regional governance in the past few decades. This article shows that reputation-seeking can...

  15. Help-Seeking Behaviors of Accounting Principles I Students.

    Science.gov (United States)

    Moncada, Susan M.; Sanders, Joseph C.

    This study examined the help-seeking propensities of college students enrolled in a "Principles of Financial Accounting I" course. A total of 364 students responded to a questionnaire on various aspects of help-seeking behavior. It was found that the most frequently used source of help was friends or classmates, followed by the instructor and the…

  16. Social Support Seeking and Early Adolescent Depression and Anxiety Symptoms

    Science.gov (United States)

    Vélez, Clorinda E.; Krause, Elizabeth D.; McKinnon, Allison; Brunwasser, Steven M.; Freres, Derek R.; Abenavoli, Rachel M.; Gillham, Jane E.

    2016-01-01

    This study examined how social support seeking and rumination interacted to predict depression and anxiety symptoms 6 months later in early adolescents (N = 118; 11-14 years at baseline). We expected social support seeking would be more helpful for adolescents engaging in low rather than high levels of rumination. Adolescents self-reported on all…

  17. Predicting Intentions to Seek Psychological Help Among Botswana University Students

    Directory of Open Access Journals (Sweden)

    Mpho M. Pheko

    2013-07-01

    Full Text Available The current study had two main objectives. The first was to investigate Botswana’s university students’ intentions to seek psychological help. The second was to investigate whether (a Attitude Toward Seeking Professional Psychological Help (ATSPPH, (b Self-Stigma of Seeking Help (SSOSH, and (c Social Stigma of Receiving Psychological Help (SSRPH predicted the students’ intentions to seek psychological help. A total of N = 519 (283 females and 236 males students from the University of Botswana completed the survey. Results indicated that generally, the students had moderate intentions of seeking psychological help. Multiple regression analysis revealed that of the three predictors, only ATSPPH and SSRPH significantly predicted intentions to seek psychological help. The current study is important because while it has been established that university students are a high-risk population for mental health problems, there is close to nothing documented on university students in Botswana. Findings of the current study will undoubtedly increase knowledge relating to psychological help-seeking and its predictors in Botswana and may inform interventions that aim to encourage young people to seek psychological or counseling help.

  18. Patients' intentions to seek medication information from pharmacists.

    Science.gov (United States)

    Huston, Sally A

    2013-01-01

    To determine whether perceived medication use knowledge held and/or needed influenced intention to seek information from pharmacists, whether an information-intention relationship held after accounting for other variables, and whether asking medication use knowledge questions increased pharmacist information-seeking intention. Cross-sectional study. SETTING United States during July 2012. Qualtrics national panel members 21 years or older obtaining a new chronic medication within previous 30 days. Internet-administered survey. Medication information-seeking intention, medication knowledge held and needed, and pharmacist medication information-seeking intention. Although knowledge held and needed were initially significant, they became nonsignificant after adding affective and evaluative attitudes, perceived control, and risk. The final best-fitting model explained 21% of variance in pharmacist information-seeking intention. Patient intentions to seek information from pharmacists increased significantly after being asked medication use knowledge questions. Perceptions of medication risk, attitudes, and information-seeking control predict pharmacist information-seeking intention and offer pharmacists an opportunity to market information services.

  19. Suicidal Behavior and Help Seeking among Diverse College Students

    Science.gov (United States)

    Brownson, Chris; Becker, Martin Swanbrow; Shadick, Richard; Jaggars, Shanna S.; Nitkin-Kaner, Yael

    2014-01-01

    Suicidal and help-seeking behaviors of students of color remain a significant problem on college campuses. Self-reported suicidal experiences and help-seeking behavior of diverse students are examined on the basis of results from a national survey of college student mental health. The results suggest significant differences in the expression of…

  20. The Information-Seeking Habits of Engineering Faculty

    Science.gov (United States)

    Engel, Debra; Robbins, Sarah; Kulp, Christina

    2011-01-01

    Many studies of information-seeking habits of engineers focus on understanding the similarities and differences between scientists and engineers. This study explores the information-seeking behavior of academic engineering faculty from twenty public research universities. This investigation includes an examination of how frequently engineer- ing…

  1. The Information Seeking and Use Behaviors of Retired Investors

    Science.gov (United States)

    O'Connor, Lisa G.

    2013-01-01

    This exploratory study examines the information seeking and use behaviors of a group of US retired or near-retirement investors from everyday life information seeking and serious leisure perspectives. Although primarily qualitative, it also collects and analyzes quantitative data to describe retired investors' information preferences and use.…

  2. Investigating the News Seeking Behavior of Young Adults

    Science.gov (United States)

    Qayyum, M. Asim; Williamson, Kirsty; Liu, Ying-Hsang; Hider, Philip

    2010-01-01

    This study investigated the news-seeking and browsing behaviours of young adults, partly in the context of everyday life information seeking (ELIS), in order to explore their perceptions of and attitudes towards print and online news media. The study is significant because traditional print newspapers face a steady decline in their readership with…

  3. Social Goals and Willingness to Seek Help for School Violence

    Science.gov (United States)

    Yablon, Yaacov B.

    2012-01-01

    The relation between students' social goals and their willingness to seek help for school violence was examined. Four hundred and sixty-two students from sixth, eighth, and tenth grades responded to vignettes used to assess willingness to seek help from teachers and friends for dealing with relational and physical violence. Intimacy goals enhanced…

  4. Social Comparison Information and Judgments about Depression and Seeking Counseling.

    Science.gov (United States)

    Strohmer, Douglas C.; And Others

    1984-01-01

    Used a role playing technique to examine the influence of social comparison on help seeking attitudes in 80 students. Results indicated that subjects who received serious social comparison information reported the highest depression scores and were more willing to seek counseling help. (JAC)

  5. How nurses seek and evaluate clinical guidelines on the Internet

    NARCIS (Netherlands)

    Verhoeven, F.; Steehouder, M.F.; Hendrix, Ron M.G.; van Gemert-Pijnen, Julia E.W.C.

    2010-01-01

    Aim: This paper is a report of a study conducted to assess nurses’ information-seeking strategies and problems encountered when seeking clinical guidelines on the Internet, and to investigate the criteria they apply when evaluating the guidelines and the websites communicating the guidelines. -

  6. The Role of Personality in Musicians' Information Seeking for Creativity

    Science.gov (United States)

    Kostagiolas, Petros; Lavranos, Charilaos; Martzoukou, Konstantina; Papadatos, Joseph

    2017-01-01

    Introduction: This paper explores the relationship between musicians' information seeking behaviour and their personality traits within the context of musical creativity. Although previous research has addressed different socio-technological and behavioral aspects of music information seeking, the role of personality characteristics around…

  7. Attitude and help-seeking for hearing impairment

    NARCIS (Netherlands)

    vandenBrink, RHS; Wit, HP; Kempen, GIJM; vanHeuvelen, MJG

    1996-01-01

    The aim of the present study was to investigate help-seeking for hearing impairment in the elderly, and to compare groups showing dissimilar help-seeking on their attitude toward hearing loss and hearing aids. Attitude factors were based on a revised version of the Health Belief Model, and included

  8. Family Functioning and Adolescent Help-Seeking Behavior.

    Science.gov (United States)

    Fallon, Barry J.; Bowles, Terry V. P.

    2001-01-01

    Examined relationship between help seeking behavior and family functioning. Adolescents who sought help clustered into two groups of families - one high in conflict and low in democratic parenting style, and one low in conflict and high in democratic parenting style. Complex relationships between help seeking behavior, type of family, and type of…

  9. Exploring University Students' Online Information Seeking about Prescription Medications

    Science.gov (United States)

    Alkhalaf, Ahmad Abdullah

    2013-01-01

    This study explored university students' information seeking behaviors related to prescription medication (PM) information. Specifically, it examined the different sources students use for PM information, their use and perceptions of online sources, the types of PM information they seek, their concerns about, and methods they apply to verify the…

  10. Investigating the News Seeking Behavior of Young Adults

    Science.gov (United States)

    Qayyum, M. Asim; Williamson, Kirsty; Liu, Ying-Hsang; Hider, Philip

    2010-01-01

    This study investigated the news-seeking and browsing behaviours of young adults, partly in the context of everyday life information seeking (ELIS), in order to explore their perceptions of and attitudes towards print and online news media. The study is significant because traditional print newspapers face a steady decline in their readership with…

  11. Hypothalamic control of male aggression-seeking behavior.

    Science.gov (United States)

    Falkner, Annegret L; Grosenick, Logan; Davidson, Thomas J; Deisseroth, Karl; Lin, Dayu

    2016-04-01

    In many vertebrate species, certain individuals will seek out opportunities for aggression, even in the absence of threat-provoking cues. Although several brain areas have been implicated in the generation of attack in response to social threat, little is known about the neural mechanisms that promote self-initiated or 'voluntary' aggression-seeking when no threat is present. To explore this directly, we utilized an aggression-seeking task in which male mice self-initiated aggression trials to gain brief and repeated access to a weaker male that they could attack. In males that exhibited rapid task learning, we found that the ventrolateral part of the ventromedial hypothalamus (VMHvl), an area with a known role in attack, was essential for aggression-seeking. Using both single-unit electrophysiology and population optical recording, we found that VMHvl neurons became active during aggression-seeking and that their activity tracked changes in task learning and extinction. Inactivation of the VMHvl reduced aggression-seeking behavior, whereas optogenetic stimulation of the VMHvl accelerated moment-to-moment aggression-seeking and intensified future attack. These data demonstrate that the VMHvl can mediate both acute attack and flexible seeking actions that precede attack.

  12. 19 CFR 171.3 - Oral presentations seeking relief.

    Science.gov (United States)

    2010-04-01

    ... 19 Customs Duties 2 2010-04-01 2010-04-01 false Oral presentations seeking relief. 171.3 Section... OF THE TREASURY (CONTINUED) FINES, PENALTIES, AND FORFEITURES Application for Relief § 171.3 Oral presentations seeking relief. (a) For violation of section 592 or section 593A. If the penalty incurred is for a...

  13. The role of 18F–NaF PET/CT in metastatic bone disease

    Directory of Open Access Journals (Sweden)

    Mine Araz

    2015-09-01

    Conclusion: Although further prospective clinical studies in specific cancer populations are indicated to set the place of 18F–NaF PET/CT in diagnostic scheme, the results of this pilot study from our country support the superiority of 18F–NaF PET/CT in investigation of bone metastasis over 99mTc-MDP bone scan and 18F-FDG PET/CT in various malignancies. 18F–NaF PET/CT is coming forward as a single step bone seeking study, considering all the advantages, but especially potential of detecting occult metastases and reliably directing patient management.

  14. Establishment of an experimental human lung adenocarcinoma cell line SPC-A-1BM with high bone metastases potency by {sup 99m}Tc-MDP bone scintigraphy

    Energy Technology Data Exchange (ETDEWEB)

    Yang Shunfang [Department of Nuclear Medicine, Shanghai Chest Hospital of Shanghai Jiaotong University, Shanghai 200030 (China)], E-mail: yzyg@sh163.net; Dong Qianggang [Laboratory of Mol-diagnosis, Shanghai Cancer Institute of Shanghai Jiaotong University, Shanghai 200032 (China); Yao Ming [Laboratory of Pathology, Shanghai Cancer Institute of Shanghai Jiaotong University, Shanghai 200032 (China); Shi Meiping [Department of Pathology, Shanghai Chest Hospital of Shanghai Jiaotong University, Shanghai 200030 (China); Ye Jianding [Department of Radiology, Shanghai Chest Hospital of Shanghai Jiaotong University, Shanghai 200030 (China); Zhao Langxiang [Department of Pathology, Shanghai Chest Hospital of Shanghai Jiaotong University, Shanghai 200030 (China); Su Jianzhong; Gu Weiyong [Shanghai Thoracic Tumor Institute, Shanghai Chest Hospital of Shanghai Jiaotong University, Shanghai 200030 (China); Xie Wenhui [Department of Nuclear Medicine, Shanghai Chest Hospital of Shanghai Jiaotong University, Shanghai 200030 (China); Wang Kankan; Du Yanzhi [State Key Laboratory of Medical Genomics, Ruijin Hospital of Shanghai Jiaotong University, Shanghai 200025 (China); Li Yao [State Key Laboratory of Genetic Engineering, Institute of Genetics, School of Life Science, Fudan University, Shanghai 200433 (China); Huang Yan [State Key Laboratory of Genetic Engineering, Institute of Genetics, School of Life Science, Fudan University, Shanghai 200433 (China)], E-mail: huangyan@fudan.edu.cn

    2009-04-15

    Background: Bone metastasis is one of the most common clinical phenomena of late stage lung cancer. A major impediment to understanding the pathogenesis of bone metastasis has been the lack of an appropriate animal and cell model. This study aims to establish human lung adenocarcinoma cell line with highly bone metastases potency with {sup 99m}Tc-MDP bone scintigraphy. Methods: The human lung adenocarcinoma cancer cells SPC-A-1 were injected into the left cardiac ventricle of NIH-Beige-Nude-XID (NIH-BNX) immunodeficient mice. The metastatic lesions of tumor-bearing mice were imaged with {sup 99m}Tc-MDP bone scintigraphy on a Siemens multi-single photon emission computed tomography. Pinhole images were acquired on a GZ-B conventional gamma camera with a self-designed pinhole collimator. The mice with bone metastasis were sacrificed under deep anesthesia, and the lesions were resected. Bone metastatic cancer cells in the resected lesions were subjected for culture and then reinoculated into the NIH-BNX mice through left cardiac ventricle. The process was repeated for eight cycles to obtain a novel cell subline SPC-A-1BM. Real-time polymerase chain reaction (PCR) was used to compare the gene expression differences in the parental and SPC-A-1BM cells. Results: The bone metastasis sites were successfully revealed by bone scintigraphy. The established bone metastasis cell line SPC-A-1BM had a high potential to metastasize in bone, including mandible, humerus, thoracic vertebra, lumbar, femur, patella, ilium and cartilage rib. The expression level of vascular endothelial growth factor gene family, Bcl-2 and cell adhesion-related genes ECM1, ESM1, AF1Q, SERPINE2 and FN1 were examined. Gene expression difference was found between parental and bone-seeking metastasis cell SPC-A-1BM, which indicates SPC-A-1BM has metastatic capacity vs. its parental cells. Conclusion: SPC-A-1BM is a bone-seeking metastasis human lung adenocarcinoma cell line. Bone scintigraphy may be used as

  15. Establishment of an experimental human lung adenocarcinoma cell line SPC-A-1BM with high bone metastases potency by (99m)Tc-MDP bone scintigraphy.

    Science.gov (United States)

    Yang, Shunfang; Dong, Qianggang; Yao, Ming; Shi, Meiping; Ye, Jianding; Zhao, Langxiang; Su, Jianzhong; Gu, Weiyong; Xie, Wenhui; Wang, Kankan; Du, Yanzhi; Li, Yao; Huang, Yan

    2009-04-01

    Bone metastasis is one of the most common clinical phenomena of late stage lung cancer. A major impediment to understanding the pathogenesis of bone metastasis has been the lack of an appropriate animal and cell model. This study aims to establish human lung adenocarcinoma cell line with highly bone metastases potency with (99m)Tc-MDP bone scintigraphy. The human lung adenocarcinoma cancer cells SPC-A-1 were injected into the left cardiac ventricle of NIH-Beige-Nude-XID (NIH-BNX) immunodeficient mice. The metastatic lesions of tumor-bearing mice were imaged with (99m)Tc-MDP bone scintigraphy on a Siemens multi-single photon emission computed tomography. Pinhole images were acquired on a GZ-B conventional gamma camera with a self-designed pinhole collimator. The mice with bone metastasis were sacrificed under deep anesthesia, and the lesions were resected. Bone metastatic cancer cells in the resected lesions were subjected for culture and then reinoculated into the NIH-BNX mice through left cardiac ventricle. The process was repeated for eight cycles to obtain a novel cell subline SPC-A-1BM. Real-time polymerase chain reaction (PCR) was used to compare the gene expression differences in the parental and SPC-A-1BM cells. The bone metastasis sites were successfully revealed by bone scintigraphy. The established bone metastasis cell line SPC-A-1BM had a high potential to metastasize in bone, including mandible, humerus, thoracic vertebra, lumbar, femur, patella, ilium and cartilage rib. The expression level of vascular endothelial growth factor gene family, Bcl-2 and cell adhesion-related genes ECM1, ESM1, AF1Q, SERPINE2 and FN1 were examined. Gene expression difference was found between parental and bone-seeking metastasis cell SPC-A-1BM, which indicates SPC-A-1BM has metastatic capacity vs. its parental cells. SPC-A-1BM is a bone-seeking metastasis human lung adenocarcinoma cell line. Bone scintigraphy may be used as an accurate, sensitive, noninvasive tool to detect

  16. Information Seeking When Problem Solving: Perspectives of Public Health Professionals.

    Science.gov (United States)

    Newman, Kristine; Dobbins, Maureen; Yost, Jennifer; Ciliska, Donna

    2017-04-01

    Given the many different types of professionals working in public health and their diverse roles, it is likely that their information needs, information-seeking behaviors, and problem-solving abilities differ. Although public health professionals often work in interdisciplinary teams, few studies have explored their information needs and behaviors within the context of teamwork. This study explored the relationship between Canadian public health professionals' perceptions of their problem-solving abilities and their information-seeking behaviors with a specific focus on the use of evidence in practice settings. It also explored their perceptions of collaborative information seeking and the work contexts in which they sought information. Key Canadian contacts at public health organizations helped recruit study participants through their list-servs. An electronic survey was used to gather data about (a) individual information-seeking behaviors, (b) collaborative information-seeking behaviors, (c) use of evidence in practice environments, (d) perceived problem-solving abilities, and (e) demographic characteristics. Fifty-eight public health professionals were recruited, with different roles and representing most Canadian provinces and one territory. A significant relationship was found between perceived problem-solving abilities and collaborative information-seeking behavior (r = -.44, p information seeking. The results suggested that when public health professionals take a shared, active approach to problem solving, maintain personal control, and have confidence, they are more likely collaborate with others in seeking information to complete a work task. Administrators of public health organizations should promote collaboration by implementing effective communication and information-seeking strategies, and by providing information resources and retrieval tools. Public health professionals' perceived problem-solving abilities can influence how they collaborate in

  17. Neural substrate of cold-seeking behavior in endotoxin shock.

    Directory of Open Access Journals (Sweden)

    Maria C Almeida

    Full Text Available Systemic inflammation is a leading cause of hospital death. Mild systemic inflammation is accompanied by warmth-seeking behavior (and fever, whereas severe inflammation is associated with cold-seeking behavior (and hypothermia. Both behaviors are adaptive. Which brain structures mediate which behavior is unknown. The involvement of hypothalamic structures, namely, the preoptic area (POA, paraventricular nucleus (PVH, or dorsomedial nucleus (DMH, in thermoregulatory behaviors associated with endotoxin (lipopolysaccharide [LPS]-induced systemic inflammation was studied in rats. The rats were allowed to select their thermal environment by freely moving in a thermogradient apparatus. A low intravenous dose of Escherichia coli LPS (10 microg/kg caused warmth-seeking behavior, whereas a high, shock-inducing dose (5,000 microg/kg caused cold-seeking behavior. Bilateral electrocoagulation of the PVH or DMH, but not of the POA, prevented this cold-seeking response. Lesioning the DMH with ibotenic acid, an excitotoxin that destroys neuronal bodies but spares fibers of passage, also prevented LPS-induced cold-seeking behavior; lesioning the PVH with ibotenate did not affect it. Lesion of no structure affected cold-seeking behavior induced by heat exposure or by pharmacological stimulation of the transient receptor potential (TRP vanilloid-1 channel ("warmth receptor". Nor did any lesion affect warmth-seeking behavior induced by a low dose of LPS, cold exposure, or pharmacological stimulation of the TRP melastatin-8 ("cold receptor". We conclude that LPS-induced cold-seeking response is mediated by neuronal bodies located in the DMH and neural fibers passing through the PVH. These are the first two landmarks on the map of the circuitry of cold-seeking behavior associated with endotoxin shock.

  18. A simple way to distinguish bed clothing contamination in a whole body bone scan: a case report

    Directory of Open Access Journals (Sweden)

    Assadi Majid

    2007-12-01

    Full Text Available Abstract Whole body bone scan with Technetium-99m MDP (methylene diphosphate can detect bony lesions due to altered osteoblastic activity. Non-physiologic or increased radiotracer uptake in the bony structures of patients with a history of malignant diseases is usually interpreted as being suspicious of bone metastasis. It is extremely important to properly distinguish false positive sites of Tc-99m MDP localization. We present three patients with the same pattern of Tc-99m MDP abnormality in different locations. These scans were all performed on the same day to evaluate possible bone metastases in three patients with breast carcinoma. After careful examination, repeated images revealed bed clothing contamination. This is different from bed contamination by displacement among different patients. It is also different from detector contamination by limited area of involvement where detector contamination appears as a line throughout the total body projection. It can be helpful if a nuclear medicine specialist has a brief look at all scans prior to reporting them. In cases where the same pattern of abnormality is repeated in all images, the possibility of technical error such as bed clothing contamination rather than a pathological abnormality should be borne in mind.

  19. Critical Thinking I:Seeking Conceptual Clarity

    Institute of Scientific and Technical Information of China (English)

    ZHAN Lin; LEE Shirleatha; FLEMING Belinda

    2014-01-01

    “Critical Thinking”在20世纪90年代初引入中国护理界,被译为“评判性思维(批判性思维)”,相关护理研究多着眼于其字面含义的“评判”“批判”,然而“Critical Thinking”是指“以解决问题为目的导向,基于对问题的认知,训练有素且公正地收集、评估和分析相关信息,不断质疑、反思和评判,进而应用逻辑推理和归纳的方法,做出最佳决策的综合性思维模式”,故“评判”“批判”仅仅是“Critical Thinking”的一部分,这也就导致了部分护理工作者对“Critical Thinking”概念的局限性理解和学术上的误导。为厘清“Critical Thinking”的概念,本刊名誉主编美国护理科学院院士、孟菲斯大学鲁文贝格护理学院院长、终身教授、护理学博士詹林教授,以及鲁文贝格护理学院Lee Shirleatha教授和Fleming Belinda教授共同撰写3篇专题稿件,本期刊登第1篇《Critical Thinking I:Seeking Conceptual Clarity》,从哲学、心理学、教育学和护理学角度阐释“Critical Thinking”的定义、特征及构成要素,并介绍“Critical Thinking”在护理临床实践和护理教育领域的引申含义,旨在引发护理同仁针对“Critical Thinking”的思考与讨论,欢迎广大读者就该主题撰稿探讨。投稿方式为登录护理学报网站www.hlxb.com.cn在线投稿,文题后加括号注明“讨论”二字。

  20. Perfluorodecalin and bone regeneration

    Directory of Open Access Journals (Sweden)

    F Tamimi

    2013-01-01

    Full Text Available Perfluorodecalin (PFD is a chemically and biologically inert biomaterial and, as many perfluorocarbons, is also hydrophobic, radiopaque and has a high solute capacity for gases such as oxygen. In this article we have demonstrated, both in vitro and in vivo, that PFD may significantly enhance bone regeneration. Firstly, the potential benefit of PFD was demonstrated by prolonging the survival of bone marrow cells cultured in anaerobic conditions. These findings translated in vivo, where PFD incorporated into bone-marrow-loaded 3D-printed scaffolds substantially improved their capacity to regenerate bone. Secondly, in addition to biological applications, we have also shown that PFD improves the radiopacity of bone regeneration biomaterials, a key feature required for the visualisation of biomaterials during and after surgical implantation. Finally, we have shown how the extreme hydrophobicity of PFD enables the fabrication of highly cohesive self-setting injectable biomaterials for bone regeneration. In conclusion, perfluorocarbons would appear to be highly beneficial additives to a number of regenerative biomaterials, especially those for bone regeneration.

  1. Pathogenesis of bone metastasis

    Directory of Open Access Journals (Sweden)

    Erdinc Nayir

    2016-01-01

    Full Text Available Bone metastases are more frequently seen as a complication of cancer than primary bone tumors. For example, it can be seen in as many as 70% of advanced stage breast and prostate cancer cases. Metastatic bone disease is generally categorized as osteoblastic, and osteolytic disease. However most of the cancer types demonstrate a wide spectrum between these two extremes. Paracrine interaction between parathyroid hormone–related protein (PTHrP which increases the rate of bone osteolysis, and transforming growth factor-β (TGF-β plays a role in osteolytic metastasis. Increased local bone PTHrP concentration increases expression of receptor activator of nuclear factor kappa-B ligand (RANKL with resultant activation of osteoclastogenesis. Endothelin – 1 (ET-1, and dickkopf homolog -1 (DKK-1 produced by tumor involve in osteoblastic metastasis. DKK-1 is the central regulator of osteoblastic activity, and osteoblastic bone metastasis. For the elaboration of treatment strategies against frequently seen complication, that is, bone metastases, targets involving in pathogenesis of these complications should be taken into consideration.

  2. Mechanotransduction by bone cells in vitro: mechanobiology of bone tissue

    NARCIS (Netherlands)

    Mullender, M.; El Haj, A.J.; Yang, Y.; van Duin, M.A.; Burger, E.H.; Klein-Nulend, J.

    2004-01-01

    Mechanical force plays an important role in the regulation of bone remodelling in intact bone and bone repair. In vitro, bone cells demonstrate a high responsiveness to mechanical stimuli. Much debate exists regarding the critical components in the load profile and whether different components, such

  3. Seeking Haven and Seeking Jobs: Migrant Workers’ Networks in Two Thai Locales

    Directory of Open Access Journals (Sweden)

    Nobpaon Rabibhadana

    2013-08-01

    Full Text Available Thailand has seen a large increase in migrant workers from Myanmar since the 1990s. A constant flow of migrants arrive to seek refuge from dire circumstances in their homeland and/or to seek better work opportunities. They have adapted to changing state policy regarding their migrant status and work permits as well as to more immediate means of control. Previous works on this subject have tended either toward macro-level policy and economics, or more journalistic accounts of individual migrant experiences. Little attention has been paid to differences in the migrant processes and networks formed across the border and within the country.  In this paper two locales, one on the border (Mae Sot and one in the interior (Samut Songkhram, are compared based on interviews conducted with migrant workers on their mode of arrival, living and working conditions, migrant status and control, and how they form networks and relations within and across the border. By comparing the two locales, rather than emphasize how the state and geopolitical space define mobility we argue that transnational migrant workers formulate and define their space through adaptive networks in articulation with geopolitical factors as well as local socioeconomic and historical-cultural dynamics. The dynamics among macro policies, micro-level agency of migrants, and meso-level networks define each locale.

  4. Avoiding versus seeking: the relationship of information seeking to avoidance, blunting, coping, dissonance, and related concepts*

    Science.gov (United States)

    Case, Donald O.; Andrews, James E.; Johnson, J. David; Allard, Suzanne L.

    2005-01-01

    Question: How have theorists and empirical researchers treated the human tendency to avoid discomforting information? Data Sources: A historical review (1890–2004) of theory literature in communication and information studies, coupled with searches of recent studies on uptake of genetic testing and on coping strategies of cancer patients, was performed. Study Selection: The authors' review of the recent literature included searches of the MEDLINE, PsychInfo, and CINAHL databases between 1992 and summer of 2004 and selective, manual searches of earlier literature. Search strategies included the following subject headings and key words: MeSH headings: Genetic Screening/psychology, Decision Making, Neoplasms/diagnosis/genetics/psychology; CINAHL headings: Genetic Screening, Genetic Counseling, Anxiety, Decision Making, Decision Making/Patient; additional key words: avoidance, worry, monitoring, blunting, cancer. The “Related Articles” function in MEDLINE was used to perform additional “citation pearl” searching. Main Results: The assumption that individuals actively seek information underlies much of psychological theory and communication practice, as well as most models of the information-seeking process. However, much research has also noted that sometimes people avoid information, if paying attention to it will cause mental discomfort or dissonance. Cancer information in general and genetic screening for cancer in particular are discussed as examples to illustrate this pattern. Conclusion: That some patients avoid knowledge of imminent disease makes avoidance behavior an important area for social and psychological research, particularly with regard to genetic testing. PMID:16059425

  5. Avoiding versus seeking: the relationship of information seeking to avoidance, blunting, coping, dissonance, and related concepts.

    Science.gov (United States)

    Case, Donald O; Andrews, James E; Johnson, J David; Allard, Suzanne L

    2005-07-01

    How have theorists and empirical researchers treated the human tendency to avoid discomforting information? A historical review (1890-2004) of theory literature in communication and information studies, coupled with searches of recent studies on uptake of genetic testing and on coping strategies of cancer patients, was performed. The authors' review of the recent literature included searches of the MEDLINE, PsychInfo, and CINAHL databases between 1992 and summer of 2004 and selective, manual searches of earlier literature. Search strategies included the following subject headings and key words: MeSH headings: Genetic Screening/psychology, Decision Making, Neoplasms/diagnosis/genetics/psychology; CINAHL headings: Genetic Screening, Genetic Counseling, Anxiety, Decision Making, Decision Making/Patient; additional key words: avoidance, worry, monitoring, blunting, cancer. The "Related Articles" function in MEDLINE was used to perform additional "citation pearl" searching. The assumption that individuals actively seek information underlies much of psychological theory and communication practice, as well as most models of the information-seeking process. However, much research has also noted that sometimes people avoid information, if paying attention to it will cause mental discomfort or dissonance. Cancer information in general and genetic screening for cancer in particular are discussed as examples to illustrate this pattern. That some patients avoid knowledge of imminent disease makes avoidance behavior an important area for social and psychological research, particularly with regard to genetic testing.

  6. Acidosis, hypoxia and bone.

    Science.gov (United States)

    Arnett, Timothy R

    2010-11-01

    Bone homeostasis is profoundly affected by local pH and oxygen tension. It has long been recognised that the skeleton contains a large reserve of alkaline mineral (hydroxyapatite), which is ultimately available to neutralise metabolic H(+) if acid-base balance is not maintained within narrow limits. Bone cells are extremely sensitive to the direct effects of pH: acidosis inhibits mineral deposition by osteoblasts but it activates osteoclasts to resorb bone and other mineralised tissues. These reciprocal responses act to maximise the availability of OH(-) ions from hydroxyapatite in solution, where they can buffer excess H(+). The mechanisms by which bone cells sense small pH changes are likely to be complex, involving ion channels and receptors in the cell membrane, as well as direct intracellular effects. The importance of oxygen tension in the skeleton has also long been known. Recent work shows that hypoxia blocks the growth and differentiation of osteoblasts (and thus bone formation), whilst strongly stimulating osteoclast formation (and thus bone resorption). Surprisingly, the resorptive function of osteoclasts is unimpaired in hypoxia. In vivo, tissue hypoxia is usually accompanied by acidosis due to reduced vascular perfusion and increased glycolytic metabolism. Thus, disruption of the blood supply can engender a multiple negative impact on bone via the direct actions of reduced pO(2) and pH on bone cells. These observations may contribute to our understanding of the bone disturbances that occur in numerous settings, including ageing, inflammation, fractures, tumours, anaemias, kidney disease, diabetes, respiratory disease and smoking.

  7. Osteosarcoma of jaw bone

    Directory of Open Access Journals (Sweden)

    Avani Gandhi Dixit

    2008-01-01

    Full Text Available Osteosarcoma is the most common primary malignant bone tumor in children. Its radiolographic appearances vary considerably. It may show a number of presentations from onion skin or sunburst appearance. Osteosarcoma of maxilla and mandible are distinct from long bone osteosarcoma and shows a distinct clinical, histologic and prognostic characteristic that when diagnosed and treated properly have a better prognosis from the later. The present article reports a case of osteogenic sarcoma of maxillary alveolar ridge and compares it with long bones osteosarcomas.

  8. Extinction of drug seeking: Neural circuits and approaches to augmentation.

    Science.gov (United States)

    McNally, Gavan P

    2014-01-01

    Extinction training can reduce drug seeking behavior. This article reviews the neural circuits that contribute to extinction and approaches to enhancing the efficacy of extinction. Extinction of drug seeking depends on cortical-striatal-hypothalamic and cortical-hypothalamic-thalamic pathways. These pathways interface, in the hypothalamus and thalamus respectively, with the neural circuits controlling reinstatement of drug seeking. The actions of these pathways at lateral hypothalamic orexin neurons, and of perifornical/dorsomedial hypothalamic derived opioid peptides at kappa opioid receptors in the paraventricular thalamus, are important for inhibiting drug seeking. Despite effectively reducing or inhibiting drug seeking in the short term, extinguished drug seeking is prone to relapse. Three different strategies to augment extinction learning or retrieval are reviewed: pharmacological augmentation, retrieval - extinction training, and provision of extinction memory retrieval cues. These strategies have been used in animal models and with human drug users to enhance extinction or cue exposure treatments. They hold promise as novel strategies to promote abstinence from drug seeking. This article is part of a Special Issue entitled 'NIDA 40th Anniversary Issue'.

  9. Relatives' advice and health care-seeking behaviour in oman.

    Science.gov (United States)

    Al-Mandhari, Ahmed; Al-Adawi, Samir; Al-Zakwani, Ibrahim; Al-Shafaee, Mohammed; Eloul, Liyam

    2009-12-01

    It has been well established that pathways to care are considerably modified by local, social and psychological characteristics as well as the doctor-patient relationship. Scant attention has been paid to the role of family advice in care-seeking. In Omani society, traditional family values and a collective mindset are the norm rather than the exception. This paper examines how family advice affects the trajectory of care seeking. During 2006-2007, data was collected through face-to-face interviews among a randomised sample of patients seeking medical consultation in various primary health care centres in the northern region of Oman. This study enrolled a total of 493 patients. The association between the advice of family members as a reason to seek health care and other predictors was analysed using multivariable logistic regression. The data suggest that the advice of family members in care-seeking is strongly associated with gender, education, history of chronic illness, previous exposure to traditional medicine, and health education, as well as the history of immunisation. These findings suggest that the advice of family members remains a strong catalyst for care-seeking in Oman. The psychosocial factors affecting care-seeking leading to underutilisation of services or otherwise are discussed.

  10. A Review on Information Seeking Behaviour Literature in Iran

    Directory of Open Access Journals (Sweden)

    shiva yari

    2014-12-01

    Full Text Available This article reviews the condition of information seeking behavior in Iran with analytical and qualittatire approaches to exhibit a clear, scientific, and read condition of it. Published literature has been reviewed both in theoretical bases and accomplished researches. So, all published literature including books, articles, theses, and research plans that has been released and distributed in Iran and were effective in this domain, has been studied. Reviews showed that the information seeking behavior has had a developing trend in quality and quantity form the last seventeen years of its emerging in Iran. Lower than 4% of published literature has been translated. Most resources have studied the information seeking behavior in research form. Scholar’s information seeking behavior has been done in most researches (about 34% of all researches. Then students’ information seeking behavior (about 17% and researches’ information seeking behavior (about 14% has been done. The least attention has been about examination of publics’ information seeking behavior and public library members. Reviews show that most researches have been at science and research units of Azad University in Tehran and Ahvaz. According to accomplished analysis, most articles has been published in National Studies of Librarianship and Information quarterly (previously Faslname Ketab, Processing and management of Information quarterly, and Librarianship and Information quarterly, respectively. This domain has been focused by librarians and somewhat by specialists of agricultural, social communication science, course planning, and government management fields.

  11. Sexual Health Information Seeking Online Among Runaway and Homeless Youth.

    Science.gov (United States)

    Barman-Adhikari, Anamika; Rice, Eric

    2011-06-01

    Research shows runaway and homeless youth are reluctant to seek help from traditional health providers. The Internet can be useful in engaging this population and meeting their needs for sexual health information, including information about HIV and other sexually transmitted infections (STIs). Using a sample of homeless youth living in Los Angeles, California in June 2009, this study assesses the frequency with which runaway and homeless youth seek sexual health information via the Internet, and assesses which youth are more likely to engage in seeking health information from online sources. Drawing from Andersen's (1968) health behavior model and Pescosolido's (1992) network episode model, we develop and refine a model for seeking online sexual health information among homeless youth. Rather than testing the predicative strength of a given model, our aim is to identify and explore conceptually driven correlates that may shed light on the characteristics associated with these help seeking behaviors among homeless youth. Analyses using multivariate logistic regression models reveal that among the sample of youth, females and gay males most frequently seek sexual health information online. We demonstrate the structure of social network ties (e.g., connection with parents) and the content of interactions (e.g., e-mail forwards of health information) across ties are critical correlates of online sexual health information seeking. Results show a continued connection with parents via the Internet is significantly associated with youth seeking HIV or STI information. Similarly for content of interactions, more youth who were sent health information online also reported seeking HIV information and HIV-testing information. We discuss implications for intervention and practice, focusing on how the Internet may be used for dissemination of sexual health information and as a resource for social workers to link transient, runaway, and homeless youth to care.

  12. Oral Health and Bone Disease

    Science.gov (United States)

    ... low bone mass. Research suggests a link between osteoporosis and bone loss in the jaw. The bone in the jaw supports and anchors the teeth. When the jawbone becomes less dense, tooth loss can occur, a common occurrence in older adults. Skeletal Bone Density and Dental Concerns Periodontal Disease ...

  13. Procedures and Collaborative Information Seeking: A Study of Emergency Departments

    DEFF Research Database (Denmark)

    Hertzum, Morten; Reddy, Madhu

    2015-01-01

    Information seeking is a central and inherently collaborative activity in the emergency department (ED) which is the common entry point to hospitals for nearly all acute patients. In this paper, we investigate how ED clinicians’ collabo-rative information seeking (CIS) is shaped by the procedures...... that the clinicians follow in the ED. Based on observations in two Danish EDs, we identify four pro-cedures prominent to how CIS is accomplished: the triage procedure, the timeouts, the coordinating nurse, and the recurrent opportunities for information seeking at the whiteboard. We then discuss how CIS activities...

  14. Procedures and Collaborative Information Seeking: A Study of Emergency Departments

    DEFF Research Database (Denmark)

    Hertzum, Morten; Reddy, Madhu

    2015-01-01

    Information seeking is a central and inherently collaborative activity in the emergency department (ED) which is the common entry point to hospitals for nearly all acute patients. In this paper, we investigate how ED clinicians’ collabo-rative information seeking (CIS) is shaped by the procedures...... that the clinicians follow in the ED. Based on observations in two Danish EDs, we identify four pro-cedures prominent to how CIS is accomplished: the triage procedure, the timeouts, the coordinating nurse, and the recurrent opportunities for information seeking at the whiteboard. We then discuss how CIS activities...

  15. Obstacles in the optimization of bone health outcomes in the female athlete triad.

    Science.gov (United States)

    Ducher, Gaele; Turner, Anne I; Kukuljan, Sonja; Pantano, Kathleen J; Carlson, Jennifer L; Williams, Nancy I; De Souza, Mary Jane

    2011-07-01

    Maintaining low body weight for the sake of performance and aesthetic purposes is a common feature among young girls and women who exercise on a regular basis, including elite, college and high-school athletes, members of fitness centres, and recreational exercisers. High energy expenditure without adequate compensation in energy intake leads to an energy deficiency, which may ultimately affect reproductive function and bone health. The combination of low energy availability, menstrual disturbances and low bone mineral density is referred to as the 'female athlete triad'. Not all athletes seek medical assistance in response to the absence of menstruation for 3 or more months as some believe that long-term amenorrhoea is not harmful. Indeed, many women may not seek medical attention until they sustain a stress fracture. This review investigates current issues, controversies and strategies in the clinical management of bone health concerns related to the female athlete triad. Current recommendations focus on either increasing energy intake or decreasing energy expenditure, as this approach remains the most efficient strategy to prevent further bone health complications. However, convincing the athlete to increase energy availability can be extremely challenging. Oral contraceptive therapy seems to be a common strategy chosen by many physicians to address bone health issues in young women with amenorrhoea, although there is little evidence that this strategy improves bone mineral density in this population. Assessment of bone health itself is difficult due to the limitations of dual-energy X-ray absorptiometry (DXA) to estimate bone strength. Understanding how bone strength is affected by low energy availability, weight gain and resumption of menses requires further investigations using 3-dimensional bone imaging techniques in order to improve the clinical management of the female athlete triad.

  16. Metastatic Bone Disease

    Science.gov (United States)

    ... begin in bone are much less common in adults older than 45 years. Other diseases, such as Paget’s sarcoma, post-radiation sarcoma, hyperparathyroidism, and fractures due to osteoporosis, are also possibilities. Additional tests will likely be ...

  17. Exercise and Bone Health

    Science.gov (United States)

    ... include: Brisk walking and hiking Jogging/running Dancing Jumping rope Tennis Team sports, such as basketball and soccer ... climbing Higher impact activities, such as jogging and jumping rope, increase the weight on bones and provide more ...

  18. Osteopetrosis (marble bone disease

    Directory of Open Access Journals (Sweden)

    Alexey Nikolayevich Kalyagin

    2014-01-01

    Full Text Available We report the data of the history of describing osteopetrosis (marble bone disease, its clinical features, diagnosis, and possible therapy approaches. Our own clinical case is presented.

  19. Calcaneus (Heel Bone) Fractures

    Science.gov (United States)

    ... metal plates and screws. Recovery Bones have a remarkable capacity to heal. The more severe your injury, ... herein. This information is provided as an educational service and is not intended to serve as medical ...

  20. Immunoregulation of bone remodelling.

    Science.gov (United States)

    Singh, Ajai; Mehdi, Abbass A; Srivastava, Rajeshwer N; Verma, Nar Singh

    2012-05-01

    Remodeling, a continuous physiological process maintains the strength of the bones, which maintains a delicate balance between bone formation and resorption process. This review gives an insight to the complex interaction and correlation between the bone remodeling and the corresponding changes in host immunological environment and also summarises the most recent developments occuring in the understanding of this complex field. T cells, both directly and indirectly increase the expression of receptor activator of nuclear factor kB ligand (RANKL); a vital step in the activation of osteoclasts, thus positively regulates the osteoclastogenesis. Though various cytokines, chemikines, transcription factors and co-stimulatory molecules are shared by both skeletal and immune systems, but researches are being conducted to establish and analyse their role and / or control on this complex but vital process. The understanding of this part of research may open new horizons in the management of inflammatory and autoimmune diseases, resulting into bone loss and that of osteoporosis also.

  1. Petrous Bone Cholesteatoma

    Science.gov (United States)

    Sanna, Mario; Zini, Carlo; Gamoletti, Roberto; Frau, Niccolò; Taibah, Abdel Kader; Russo, Alessandra; Pasanisi, Enrico

    1993-01-01

    Petrous bone cholesteatoma is a rare pathologic entity and may be a difficult surgical challenge because of potential involvement of the facial nerve, carotid artery, dura mater, otic capsule, and risk of cerebrospinal fluid leak. The objective of this article is to present a personal classification of petrous bone cholesteatomas, a survey of recent surgical attitudes, and our present surgical strategy based on our experience with 54 operations between 1978 and 1990. Radical petromastoid exenteration with marsupialization and the middle cranial fossa approach were used only for small pure infra- or supralabyrinthine cholesteatomas, respectively. The enlarged transcochlear approach with closure of the external auditory canal was used for infralabyrinthine, infralabyrinthine-apical, and massive petrous bone cholesteatomas. Five cases with petrous bone cholesteatomas in different locations are described in detail to present the signs and symptoms together with the management. ImagesFigure 10Figure 11Figure 12Figure 13Figure 14Figure 15Figure 16Figure 17Figure 18 PMID:17170912

  2. Bone changes in leprosy

    Energy Technology Data Exchange (ETDEWEB)

    Mende, B.; Stein, G.; Kreysel, H.W.

    1985-02-01

    Bone lesions is a frequent organic manifestation in leprosy. Osseal destructions caused by granulomatous process induced by M. leprae are so-called specific lesions in contrast to non specific lesions based on nerval or arterial diseases. The specific osseal alterations are characterized by cystic brightenings in roentgenograms while non specific osseal changes show absorption to bone structure as akroosterolysis and osteoporosis. Typical radiologic findings in different stages of mutilation are demonstrated.

  3. SHEEP TEMPORAL BONE

    Directory of Open Access Journals (Sweden)

    Kesavan

    2016-03-01

    Full Text Available INTRODUCTION Human temporal bones are difficult to procure now a days due to various ethical issues. Sheep temporal bone is a good alternative due to morphological similarities, easy to procure and less cost. Many middle ear exercises can be done easily and handling of instruments is done in the procedures like myringoplasty, tympanoplasty, stapedotomy, facial nerve dissection and some middle ear implants. This is useful for resident training programme.

  4. Calculation of the Dose of Samarium-153-Ethylene Diamine Tetramethylene Phosphonate (153Sm-EDTMP as a Radiopharmaceutical for Pain Relief of bone Metastasis

    Directory of Open Access Journals (Sweden)

    Fatemeh Razghandi

    2016-04-01

    Full Text Available Introduction One of the important applications of nuclear physics in medicine is the use of radioactive elements as radiopharmaceuticals. Metastatic bone disease is the most common form of malignant bone tumors. Samarium-153-ethylene diamine tetramethylene phosphonate (153Sm-EDTMP as a radiopharmaceutical is used for pain palliation. This radiopharmaceutical usually emits beta particles, which have a high uptake in bone tissues. The purpose of this study was to calculate the radiation dose distribution of 153Sm-EDTMP in bone and other tissues, using MCNPX Monte Carlo code in the particle transport model. Materials and Methods Dose delivery to the bone was simulated by seeking radiopharmaceuticals on the bone surface. The phantom model had a simple cylindrical geometry and included bone, bone marrow, and soft tissue. Results The simulation results showed that a significant amount of radiation dose was delivered to the bone by the use of this radiopharmaceutical. Conclusion Thebone acted as a fine protective shield against rays for the bone marrow. Therefore, the trivial absorbed dose by the bone marrow caused less damage to bone-making cells. Also, the high absorbed dose of the bone could destroy cancer cells and relieve the pain in the bone.

  5. Bone Remodeling Monitor

    Science.gov (United States)

    Foucar, Charlie; Goldberg, Leslie; Hon, Bodin; Moore, Shannon; Williams, Evan

    2009-01-01

    The impact of bone loss due to different mechanical loadings in microgravity is a major concern for astronauts upon reintroduction to gravitational forces in exploration missions to the Moon and Mars. it has been shown that astronauts not only lose bone at differing rates, with levels up to 2% per month, but each astronaut will respond to bone loss treatments differently. Pre- and post-flight imaging techniques and frozen urine samples for post-flight laboratory immunoassays To develop a novel, non-invasive, highly . sensitive, portable, intuitive, and low-powered device to measure bone resorption levels in 'real time' to provide rapid and Individualized feedback to maximize the efficacy of bone loss countermeasures 1. Collect urine specimen and analyze the level of bone resorption marker, DPD (deoxypridinoline) excreted. 2. Antibodies specific to DPD conjugated with nanoshells and mixed with specimen, the change in absorbance from agglutination is measured by an optical device. 3. The concentration of DPD is displayed and recorded on a PDA

  6. Guided bone regeneration : the influence of barrier membranes on bone grafts and bone defects

    NARCIS (Netherlands)

    Gielkens, Pepijn Frans Marie

    2008-01-01

    Guided bone regeneration (GBR) can be described as the use of a barrier membrane to provide a space available for new bone formation in a bony defect. The barrier membrane protects the defect from in-growth of soft tissue cells and allows bone progenitor cells to develop bone within a blood clot tha

  7. Health seeking behaviour of infertile women in Gombe, north ...

    African Journals Online (AJOL)

    Health seeking behaviour of infertile women in Gombe, north eastern Nigeria. ... Almost 40% sought for care more than three years after being unable to conceive ... Most of the traditional healers visited were herbalists (18.5%) native doctors ...

  8. The role of hope in financial risk seeking.

    Science.gov (United States)

    Reimann, Martin; Nenkov, Gergana Y; MacInnis, Deborah; Morrin, Maureen

    2014-12-01

    One construct validation study and four experiments showed that the relationship between hope and financial risk seeking depended on whether or not the possibility of a hoped-for outcome was threatened. Whereas high (vs. low) hope decreased financial risk seeking when the possibility of a hoped-for outcome was not threatened, high (vs. low) hope increased financial risk seeking when the outcome's possibility was threatened. These effects were observed in different contexts (i.e., gambling, stock investing, bidding, retirement investing), when applying different operationalizations of hope and threats to possibility, and when controlling for alternative explanations. We also showed that individuals' motivations to either achieve gains or avoid losses mediated the effects of hope on financial risk seeking. This research, which is the first to study the role of hope in financial decision making, adds to the extant literature by underscoring the psychological impact of threats to the possibility of attaining a hoped-for financial outcome.

  9. Rabies Exposure: When Should I Seek Medical Attention?

    Science.gov (United States)

    ... Rabies Share Compartir When should I seek medical attention? Were you exposed to rabies? What materials can ... with soap and water. See your doctor for attention for any trauma due to an animal attack ...

  10. Medical advice seeking behaviors of pregnant women in imo state ...

    African Journals Online (AJOL)

    Medical advice seeking behaviors of pregnant women in imo state, nigeria. ... instrument was ensured through constructive criticisms of seven health professionals. ... safe motherhood and family life education concepts that would sensitize the ...

  11. Some Melanoma Survivors Still Seek Out the Sun

    Science.gov (United States)

    ... https://medlineplus.gov/news/fullstory_163887.html Some Melanoma Survivors Still Seek Out the Sun 1 in ... Even after surviving the potentially deadly skin cancer melanoma, some people continue to go out in the ...

  12. Mobile information-seeking behavior: A comparative study

    National Research Council Canada - National Science Library

    Lee, Jong-Moon; Song, Yoo-Seong

    2015-01-01

    .... While such a rapid adoption of mobile devices is a worldwide phenomenon, the authors sought to investigate similarities and differences of mobile information-seeking behavior of college students in diverse regions...

  13. Chinese,Algerian Enterprises Seek to Expand Business Cooperation

    Institute of Scientific and Technical Information of China (English)

    2009-01-01

    @@ A Chinese trade delegation and representatives from Algerian companies met in Algiers,capital of Algeria on November 15 seeking further cooperation in areas such as infrastructure construction,machine building,finance,service and agriculture.

  14. Social support seeking and self-efficacy-building strategies in ...

    African Journals Online (AJOL)

    Social support seeking and self-efficacy-building strategies in enhancing the emotional ... A 3 × 2 factorial design consisting of treatment and a control group was used. The columns have two levels of gender being male and female caregivers.

  15. Care seeking for maternal health: challenges remain for poor women

    African Journals Online (AJOL)

    Bernt Lindtjorn

    The pregnant woman is influenced by her attendants; families only seek care for complications if local or herbal, remedies .... onset of complications; the lack of accessible roads, harsh terrain ... genitalia and causes prolonged/obstructed labor.

  16. Knowledge, Attitude, and Healthcare-Seeking Behavior Towards ...

    African Journals Online (AJOL)

    Knowledge, Attitude, and Healthcare-Seeking Behavior Towards. Dysmenorrhea among Female ... had negative attitude towards dysmenorrhea. Major effects of ..... to cite this article:***. Source of Support: Nil, Conflict of Interest: None declared.

  17. Health seeking behaviour and challenges in utilising health facilities ...

    African Journals Online (AJOL)

    University College London Medical School, UK. 3. School of Sciences, Nkumba University, Uganda. Abstract ..... that are disabled or pregnant may not attempt long dis- tances to seek ... vices in Uganda: impact of women's status, traditional.

  18. Delay in Seeking and Receiving Emergency Obstetric Care in Eritrea.

    African Journals Online (AJOL)

    MBY

    Objective: To determine the extent of and main reasons for failure or delay in seeking and ... most pertinent avoidable factors for maternal death. ... assisted by health professionals. Women ... (7 randomly selected communities from each zone).

  19. Biomarkers of bone and mineral metabolism following bone marrow transplantation.

    Science.gov (United States)

    Baek, Ki Hyun; Kang, Moo Il

    2009-01-01

    The loss of bone mass often occurs after patients undergo bone marrow transplantation (BMT). The rapid impairment of bone formation and the increase in bone resorption, as mirrored by the biochemical markers of bone turnover, might play a role in this bone loss, and especially during the immediate post-BMT period. The possible direct causes for this paradoxical uncoupling are exposure to immunosuppressants, hypogonadism, the changes of cytokines, the changes of the bone growth factors, and the damage to the osteoprogenitor cells because of myeloablative therapy. In this chapter, we discuss the general aspects of post-BMT bone loss with a peculiar focus on the remodeling imbalance of bone and its relation to the use of immunosuppressants and the changes of sex hormones, growth factors, and cytokines.

  20. A Review on Information Seeking Behaviour Literature in Iran

    OpenAIRE

    shiva yari; hamid ahmadi

    2014-01-01

    This article reviews the condition of information seeking behavior in Iran with analytical and qualittatire approaches to exhibit a clear, scientific, and read condition of it. Published literature has been reviewed both in theoretical bases and accomplished researches. So, all published literature including books, articles, theses, and research plans that has been released and distributed in Iran and were effective in this domain, has been studied. Reviews showed that the information seeking...

  1. Exploring information seeking behaviour in a digital museum context

    DEFF Research Database (Denmark)

    Skov, Mette; Ingwersen, Peter

    2008-01-01

    information needs, and 2) main characteristics of virtual museum visitors' information seeking behaviour. Both quantitative and qualitative data were gathered from written enquiries to the museum, an online questionnaire and a user study of simulated interest tasks combined with retrospective think......-aloud sessions. The data collected did not show exploratory behaviour to be predominant as expected. Rather analysis of data indicates a broad coverage of different types of needs. Finally, four main characteristics of virtual museum guests' information seeking behaviour were identified....

  2. Health Seeking Behavior among Mothers of Sick Children.

    Science.gov (United States)

    Shrestha, P D

    2015-01-01

    Infant and under-five mortality rate in Nepal are 46 and 54 deaths per 1,000 live births, respectively. These mortality indicates, one in every 22 Nepalese children dies before reaching age 1, and one in every 19 does not survive to his or her fifth birthday. Delay in seeking appropriate care and not seeking any care contributes to the large number of child deaths. Existing interventions could prevent many deaths among children if they are presented at health facility and timely care. A descriptive research was carried out in Lele VDC, ward no.7, Lalitpur. The objective of this study was to find out health seeking behavior among mothers of sick children. Non probability, purposive sampling method was used. Sample size was 102 mothers who had sick children from 0 to 59 months. A set of semi structured questionnaire was used to obtain the data. The mean age of the respondent was 25.8 years and child was 29 months. Respondents' children who suffered with pneumonia, diarrhoea and malnutrition were 64(62.7%),29(28%), 9(8.8%) respectively. Majority 84(81.4%) mothers had sought treatment and among them 58(69%) sought treatment from health facility whereas 26(31%) sought treatment from traditional healer. There was significant relationship between education of the mother(p=0.05), sex of the child (p=0.004), type of sickness of children (p=0.001) of the mother and health seeking behaviour of mothers. However occupation of the mothers for seeking treatment (p=0.66) and treatment seeking at first (p=0.82) were not significant. So there was no relationship between occupation of the mothers and health seeking behaviour. Majority of the mothers sought treatment from health facility, yet around one fourth went at traditional healers. Education of the mother, sex of the child, sickness of child and mother's awareness are the factors affecting health seeking behavior of the mothers.

  3. Sexual Health Information Seeking Online Among Runaway and Homeless Youth

    OpenAIRE

    Barman-Adhikari, Anamika; Rice, Eric

    2011-01-01

    Research shows runaway and homeless youth are reluctant to seek help from traditional health providers. The Internet can be useful in engaging this population and meeting their needs for sexual health information, including information about HIV and other sexually transmitted infections (STIs). Using a sample of homeless youth living in Los Angeles, California in June 2009, this study assesses the frequency with which runaway and homeless youth seek sexual health information via the Internet,...

  4. Porous surface modified bioactive bone cement for enhanced bone bonding.

    Directory of Open Access Journals (Sweden)

    Qiang He

    Full Text Available BACKGROUND: Polymethylmethacrylate bone cement cannot provide an adhesive chemical bonding to form a stable cement-bone interface. Bioactive bone cements show bone bonding ability, but their clinical application is limited because bone resorption is observed after implantation. Porous polymethylmethacrylate can be achieved with the addition of carboxymethylcellulose, alginate and gelatin microparticles to promote bone ingrowth, but the mechanical properties are too low to be used in orthopedic applications. Bone ingrowth into cement could decrease the possibility of bone resorption and promote the formation of a stable interface. However, scarce literature is reported on bioactive bone cements that allow bone ingrowth. In this paper, we reported a porous surface modified bioactive bone cement with desired mechanical properties, which could allow for bone ingrowth. MATERIALS AND METHODS: The porous surface modified bioactive bone cement was evaluated to determine its handling characteristics, mechanical properties and behavior in a simulated body fluid. The in vitro cellular responses of the samples were also investigated in terms of cell attachment, proliferation, and osteoblastic differentiation. Furthermore, bone ingrowth was examined in a rabbit femoral condyle defect model by using micro-CT imaging and histological analysis. The strength of the implant-bone interface was also investigated by push-out tests. RESULTS: The modified bone cement with a low content of bioactive fillers resulted in proper handling characteristics and adequate mechanical properties, but slightly affected its bioactivity. Moreover, the degree of attachment, proliferation and osteogenic differentiation of preosteoblast cells was also increased. The results of the push-out test revealed that higher interfacial bonding strength was achieved with the modified bone cement because of the formation of the apatite layer and the osseointegration after implantation in the bony

  5. Role of bone marrow macrophages in controlling homeostasis and repair in bone and bone marrow niches.

    Science.gov (United States)

    Kaur, Simranpreet; Raggatt, Liza Jane; Batoon, Lena; Hume, David Arthur; Levesque, Jean-Pierre; Pettit, Allison Robyn

    2017-01-01

    Macrophages, named for their phagocytic ability, participate in homeostasis, tissue regeneration and inflammatory responses. Bone and adjacent marrow contain multiple functionally unique resident tissue macrophage subsets which maintain and regulate anatomically distinct niche environments within these interconnected tissues. Three subsets of bone-bone marrow resident tissue macrophages have been characterised; erythroblastic island macrophages, haematopoietic stem cell niche macrophages and osteal macrophages. The role of these macrophages in controlling homeostasis and repair in bone and bone marrow niches is reviewed in detail.

  6. Children's Attentional Processing of Mother and Proximity Seeking.

    Directory of Open Access Journals (Sweden)

    Guy Bosmans

    Full Text Available Attachment expectations regarding the availability of mother as a source for support are supposed to influence distressed children's support seeking behavior. Because research is needed to better understand the mechanisms related to support seeking behavior, this study tested the hypothesis that the cognitive processing of mother-related information is linked to proximity and support seeking behavior. Uncertainty in maternal support has been shown to be characterized by a biased attentional encoding of mother, reducing the breadth of children's attentional field around her. We investigated whether this attentional bias is related to how long distressed children wait before seeking their mother's proximity. Thirty-three children (9-11 years participated in this study that consisted of experimental tasks to measure attentional breadth and to observe proximity seeking behavior and of questionnaires to measure confidence in maternal support and experienced distress. Results suggested that distressed children with a more narrow attentional field around their mother wait longer to seek her proximity. Key Message: These findings provide a first support for the hypothesis that the attentional processing of mother is related to children's attachment behavior.

  7. Exploring Professional Help-Seeking for Mental Disorders.

    Science.gov (United States)

    Savage, Hannah; Murray, Joanna; Hatch, Stephani L; Hotopf, Matthew; Evans-Lacko, Sara; Brown, June S L

    2016-10-01

    Only a third of people with mental disorders seek professional help. In this study, we aimed to investigate attitudes toward help-seeking among non-help-seekers drawn from a community survey in South London. We conducted qualitative interviews with 24 participants with symptoms of mental disorders. We analyzed data using thematic analysis. Participants' reasons for not seeking professional help included perceiving their problems as normal or unsuitable for professional help, negative expectations of professional help, believing informal strategies were sufficient, fearing being stigmatized for having a mental disorder and help-seeking, and self-perceptions of being strong and/or self-reliant. A small number (n = 4) had resolved their problems. Participants with unresolved mental disorders (n = 20) had more chronic stressors, particularly about finances and family relationships, and greater concerns about professional help and stigma than other participants. Potential targets for interventions to encourage help-seeking could be focused around stigma about help-seeking as well as the self-perception of being strong.

  8. Impulsivity and sensation seeking in alcohol abusing patients with schizophrenia

    Directory of Open Access Journals (Sweden)

    Alain Dervaux

    2010-09-01

    Full Text Available Objective: Some studies have found that high levels of impulsivity and sensation seeking, particularly disinhibition are associated with substance abuse in patients with schizophrenia, as in the general population. However, no study has assessed impulsivity and sensation seeking specifically in schizophrenia patients with alcohol abuse or dependence. Material and Methods: We compared impulsivity and sensation seeking in a group of schizophrenia patients (DSM-III-R criteria with lifetime alcohol abuse or dependence (n=34 and in a group without lifetime substance abuse or dependence (n=66. The patients were assessed using the Composite International Diagnostic Interview (CIDI for DSM-III-R disorders, the Positive and Negative Syndrome Scale, the Barratt Impulsivity Scale (BIS, the Zuckerman Seeking Sensation Scale (SSS, and the Physical Anhedonia Scale (PAS. Results: The mean scores for impulsivity and sensation seeking were higher in the group with lifetime alcohol abuse or dependence than in the group without substance abuse or dependence (BIS: 63.4 SD: 18,7 vs 51.3 SD: 14.2 respectively, ANOVA: F=11.12, p=0.001; SSS: 17.6 SD: 5.9 vs 13.5 SD: 6.7 respectively, ANOVA: F=7.45, p=0.008. There was no significant differences between the two groups on PAS score. Conclusion: Increased impulsivity or sensation seeking may be a link between schizophrenia and alcohol abuse or dependence.

  9. Mimicking the nanostructure of bone matrix to regenerate bone

    Directory of Open Access Journals (Sweden)

    Robert Kane

    2013-11-01

    Full Text Available Key features of bone tissue structure and composition are capable of directing cellular behavior toward the generation of new bone tissue. Bone tissue, as well as materials derived from bone, have a long and successful history of use as bone grafting materials. Recent developments in design and processing of synthetic scaffolding systems has allowed the replication of the bone's desirable biological activity in easy to fabricate polymeric materials with nano-scale features exposed on the surface. The biological response to these new tissue-engineering scaffold materials oftentimes exceeds that seen on scaffolds produced using biological materials.

  10. Virtual Temporal Bone Anatomy

    Institute of Scientific and Technical Information of China (English)

    2007-01-01

    Background The Visible Human Project(VHP) initiated by the U.S. National Library of Medicine has drawn much attention and interests from around the world. The Visible Chinese Human (VCH) project has started in China. The current study aims at acquiring a feasible virtual methodology for reconstructing the temporal bone of the Chinese population, which may provide an accurate 3-D model of important temporal bone structures that can be used in teaching and patient care for medical scientists and clinicians. Methods A series of sectional images of the temporal bone were generated from section slices of a female cadaver head. On each sectional image, SOIs (structures of interest) were segmented by carefully defining their contours and filling their areas with certain gray scale values. The processed volume data were then inducted into the 3D Slicer software(developed by the Surgical Planning Lab at Brigham and Women's Hospital and the MIT AI Lab) for resegmentation and generation of a set of tagged images of the SOIs. 3D surface models of SOIs were then reconstructed from these images. Results The temporal bone and structures in the temporal bone, including the tympanic cavity, mastoid cells, sigmoid sinus and internal carotid artery, were successfully reconstructed. The orientation of and spatial relationship among these structures were easily visualized in the reconstructed surface models. Conclusion The 3D Slicer software can be used for 3-dimensional visualization of anatomic structures in the temporal bone, which will greatly facilitate the advance of knowledge and techniques critical for studying and treating disorders involving the temporal bone.

  11. In vivo evaluation of [{sup 11}C]-3-[2-[(3-methoxyphenylamino)carbonyl]ethenyl]-4,6-dichloroindole- 2-carboxylic acid ([{sup 11}C]3MPICA) as a PET radiotracer for the glycine site of the NMDA ion channel

    Energy Technology Data Exchange (ETDEWEB)

    Waterhouse, Rikki N. E-mail: rnw7@columbia.edu; Sultana, Abida; Laruelle, M

    2002-11-01

    Alterations in normal NMDA receptor composition, densities and function have been implicated in the pathophysiology of certain neurological and neuropsychiatric disorders such as Parkinson's Disease, Huntington's Chorea, schizophrenia, alcoholism and stroke. In our first effort to provide PET ligands for the NMDA/glycine site, we reported the synthesis of a novel high affinity glycine site ligand, 3-[2-[(3-methoxyphenylamino)carbonyl]ethenyl]-4,6-dichloroindole-2 -carboxylic acid ((3MPICA), Ki=4.8{+-}0.9 nM) and the corresponding carbon-11 labeled PET ligand, [{sup 11}C]3MPICA. We report here the in vivo evaluation of [{sup 11}C]3MPICA in rats. Biodistribution analysis revealed that [{sup 11}C]3MPICA exhibited low degree of brain penetration and high blood concentration. The average uptake at two minutes was highest in the cerebellum (0.19{+-}0.04 %ID/g) and thalamus (0.18{+-}0.05 %ID/g) and lower in the hippocampus (0.13{+-}0.03) and frontal cortex (0.11{+-}0.04 %ID/g). The radioactivity cleared quickly from all brain regions examined. Administration of unlabeled 3MPICA (1 mg/kg, i.v.) revealed at 60 minutes a small general reduction in regional brain radioactivity concentrations in treated animals versus controls, however, the blood radioactivity concentration was also lowered, confounding the assessment of the degree of saturable binding. Warfarin co-administration (100 mg/kg, i.v.) significantly lowered blood activity at 5 minutes post-injection (-27%, P<0.01) but failed to significantly increase the brain uptake of the radiotracer. In view of these results, and especially considering the low brain penetration of this tracer, [{sup 11}C]3MPICA does not appear to be a promising PET radiotracer for in vivo use.

  12. Synthesis and in vivo Evaluation of Fluorine-18 and Iodine-123 Pyrazolo[4,3-e]-1,2,4-triazolo[1,5-c]pyrimidine Derivatives as PET and SPECT Radiotracers for Mapping A2A Receptors.

    Science.gov (United States)

    Vala, Christine; Morley, Thomas J; Zhang, Xuechun; Papin, Caroline; Tavares, Adriana Alexandre S; Lee, H Sharon; Constantinescu, Cristian; Barret, Olivier; Carroll, Vincent M; Baldwin, Ronald M; Tamagnan, Gilles D; Alagille, David

    2016-09-06

    Imaging agents that target adenosine type 2A (A2A ) receptors play an important role in evaluating new pharmaceuticals targeting these receptors, such as those currently being developed for the treatment of movement disorders like Parkinson's disease. They are also useful for monitoring progression and treatment efficacy by providing a noninvasive tool to map changes in A2A receptor density and function in neurodegenerative diseases. We previously described the successful evaluation of two A2A -specific radiotracers in both nonhuman primates and in subsequent human clinical trials: [(123) I]MNI-420 and [(18) F]MNI-444. Herein we describe the development of both of these radiotracers by selection from a series of A2A ligands, based on the pyrazolo[4,3-e]-1,2,4-triazolo[1,5-c]pyrimidine core of preladenant. Each of this series of 16 ligands was found to bind to recombinant human A2A receptor in the low nanomolar range, and of these 16, six were radiolabeled with either fluorine-18 or iodine-123 and evaluated in nonhuman primates. These initial in vivo results resulted in the identification of 7-(2-(4-(4-(2-[(18) F]fluoroethoxy)phenyl)piperazin-1-yl)ethyl)-2-(furan-2-yl)-7H-pyrazolo[4,3-e][1,2,4]triazolo[1,5-c]pyrimidin-5-amine ([(18) F]MNI-444) and 7-(2-(4-(2-fluoro-4-[(123) I]iodophenyl)piperazin-1-yl)ethyl)-2-(furan-2-yl)-7H-imidazo[1,2-c]pyrazolo[4,3-e]pyrimidin-5-amine ([(123) I]MNI-420) as PET and SPECT radiopharmaceuticals for mapping A2A receptors in brain.

  13. Seeking help from everyone and no-one: Conceptualising the online help-seeking process among adolescent males

    OpenAIRE

    Best, Paul; Gil-Rodriguez, Elena; Manktelow, Roger; Taylor, Brian J.

    2016-01-01

    Online help-seeking is an emerging trend within the 21st century. Yet despite some movement towards developing online services, little is known about how young people locate, access and receive support online. This study aims to conceptualise the process of online help-seeking among adolescent males. Modified photo-elicitation techniques were employed within eight semi-structured focus group sessions with adolescent males aged 14 – 15 years (n= 56) across seven schools in Northern Ireland. Th...

  14. Inca bones at asterion

    Directory of Open Access Journals (Sweden)

    Prashant E Natekar

    2014-01-01

    Full Text Available Background: Surgical approach towards asterion has to be done with caution as many surgeons are unfamiliar with the anatomical variations. The asterion corresponds to the site of the posterolateral (mastoid fontanelle of the neonatal skull which closes at the end of the first year. Inca bones provide information as markers for various diseases, and can mislead in the diagnosis of fractures. Observation and Results: 150 dry skull bones from the Department of Anatomy at Goa Medical College, India and other neighboring medical colleges by examining the asterion, and its sutural articulations with parietal, temporal and occipital bones and also anatomical variations if any in adults. Discussion: The anatomical landmarks selected must be reliable and above all easy to identify. Bony structures are more suitable than soft tissue or cartilaginous landmarks because of their rigid and reliable location. Presence of these bones provides false impressions of fractures or the fractures may be interpreted for inca bones especially in the region of asterion either radiologically or clinically which may lead to complications during burr hole surgeries.

  15. Bone metabolism during pregnancy.

    Science.gov (United States)

    Salles, Jean Pierre

    2016-06-01

    During pregnancy, mineral concentrations, of calcium and phosphorus in particular, are maintained at a high level in fetal blood so that the developing skeleton may accrete adequate mineral content. The placenta actively transports minerals for this purpose. Maternal intestinal absorption increases in order to meet the fetal demand for calcium, which is only partly dependent on calcitriol. Mineral regulation is essentially dependent on parathyroid hormone (PTH) and PTH-related protein (PTHrP). The calcium-sensing receptor (CaSR) regulates PTH and PTHrP production. If calcium intake is insufficient, the maternal skeleton will undergo resorption due to PTHrP. After birth, a switch from fetal to neonatal homeostasis occurs through increase in PTH and calcitriol, and developmental adaptation of the kidneys and intestines with bone turnover contributing additional mineral to the circulation. Calcium absorption becomes progressively active and dependent on calcitriol. The postnatal skeleton can transiently present with osteoposis but adequate mineral diet usually allows full restoration. Cases of primary osteoporosis must be identified. Loss of trabecular mineral content occurs during lactation in order to provide calcium to the newborn. This programmed bone loss is dependent on a "brain-breast-bone" circuit. The physiological bone resorption during reproduction does not normally cause fractures or persistent osteoporosis. Women who experience fracture are likely to have other causes of bone loss. Copyright © 2016. Published by Elsevier Masson SAS.

  16. Motivation and Academic Help-Seeking in High School Computer Science

    Science.gov (United States)

    Cheong, Yuk Fai; Pajares, Frank; Oberman, Paul S.

    2004-01-01

    The primary objective of this study was to determine the degree to which academic motivation predicted the executive help-seeking, instrumental help-seeking, perceived benefits of help-seeking, and avoidance of help-seeking of high school students enrolled in computer science ( n = 314). Task goals were positively associated with instrumental help-seeking and perceiving the benefits of help-seeking and negatively associated with executive help-seeking; performance-avoid goals were negatively associated with instrumental help-seeking and positively associated with avoiding help-seeking. Controlling for motivation and computer science competence, girls were more likely to seek instrumental help and to perceive the benefits of help-seeking, and African American students were more likely to seek help than were White students or Asian American students. Despite possessing equal computer science skills, girls reported lower self-efficacy, self-concept, self-efficacy for self-regulation, and value than did boys.

  17. Online Health Information Seeking in Hand and Upper Extremity Surgery.

    Science.gov (United States)

    Özkan, Sezai; Mellema, Jos J; Nazzal, Adam; Lee, Sang-Gil; Ring, David

    2016-12-01

    Information gathering is a key component of shared decision making and has a measurable effect on treatment decisions. Access to health information might improve quality of care in hand surgery. Our purpose was to identify socio-demographic, condition-related, and psychosocial factors associated with online information-seeking behavior in patients with hand and upper-extremity conditions. From June 2015 to February 2016, we enrolled 134 patients with an upper-extremity condition who presented to an outpatient hand surgery office at an urban level I trauma center in this cross-sectional study. Participants provided socio-demographic information and completed online questionnaires assessing their online information-seeking behavior, pain intensity, symptoms of depression, and pain interference, and an upper extremity-specific, patient-reported outcome measure. A total of 57 patients (43%) sought information regarding their condition online before their visit. Compared with patients with no online information-seeking behavior, patients who sought information online were more educated. Psychosocial and condition-related factors were not associated with online information seeking. In multivariable analysis, education in years and involvement of the dominant upper limb were independently associated with online information-seeking behavior. Education in years and involvement of the dominant upper limb were independently associated with online information-seeking behavior but psychosocial and condition-related factors were not. As health information seeking is becoming an integral part of the modern day clinical experience, efforts to make online information more appealing and useful to people of all education levels are merited. Copyright © 2016 American Society for Surgery of the Hand. Published by Elsevier Inc. All rights reserved.

  18. Personality and sensation seeking in high-risk sports

    Directory of Open Access Journals (Sweden)

    Polona Klinar

    2017-03-01

    Full Text Available Background: Personality represents a relatively consistent and unique sum of psychological, cognitive and physical characteristics of an individual. Sensation seeking is defined as an action, characterized by the search for different, new, complex and intensive emotions and experiences and preparedness to take physical, social, legal and financial risks in order to achieve these experiences.Objective: We were looking for differences in personality and sensation seeking between high-risk sports athletes and recreational athletes and the correlation between one's purpose to participate in high-risk sports and actual participation.Method: The data was acquired using three different questionnaires: Sensation Seeking Scale (forms SSS - V and SSS - VI and the Big Five Questionnaire. The sample consisted of 76 high-risk sports athletes and 51 recreational athletes. Data was analyzed using the SPSS statistical program.Results: The results were unexpected because we noticed differences between the two groups in which recreational athletes received higher results, especially in openness. Mostly results from such research show the converse - athletes of high-risk sports are more open. We did not find any difference between the two groups in sensation seeking. We found some correlations between personality traits and factors of Sensation Seeking Scale (SSS - V and SSS - VI. Openness and the Thrill and adventure seeking factor correlated in both versions of SSS.Conclusions: We conclude that high-risk sports athletes differ from recreational athletes, especially in openness. Also, we can confirm that both used versions of SSS are equally effective for analyzing sensation seeking.

  19. Fractures and stresses in Bone Spring sandstones

    Energy Technology Data Exchange (ETDEWEB)

    Lorenz, J.C.; Warpinski, N.R.; Sattler, A.R.; Northrop, D.A.

    1990-09-01

    This project is a collaboration between Sandia National Laboratories and Harvey E. Yates Company being conducted under the auspices of the Oil Recovery Technology Partnership. The project seeks to apply perspectives related to the effects of natural fractures, stress, and sedimentology to the simulation and production of low-permeability gas reservoirs to low-permeability oil reservoirs as typified by the Bone Spring sandstones of the Permian Basin, southeast New Mexico. This report presents the results and analysis obtained in 1989 from 233 ft of oriented core, comprehensive suite of logs, various in situ stress measurements, and detailed well tests conducted in conjunction with the drilling of two development wells. Natural fractures were observed in core and logs in the interbed carbonates, but there was no direct evidence of fractures in the sandstones. However, production tests of the sandstones indicated permeabilities and behavior typical of a dual porosity reservoir. A general northeast trend for the maximum principal horizontal stress was observed in an elastic strain recovery measurements and in strikes of drilling-induced fractures; this direction is subparallel to the principal fracture trend observed in the interbed carbonates. Many of the results presented are believed to be new information for the Bone Spring sandstones. 57 figs., 18 tabs.

  20. Bone printing: new frontiers in the treatment of bone defects.

    Science.gov (United States)

    Arealis, Georgios; Nikolaou, Vasileios S

    2015-12-01

    Bone defects can be congenital or acquired resulting from trauma, infection, neoplasm and failed arthroplasty. The osseous reconstruction of these defects is challenging. Unfortunately, none of the current techniques for the repair of bone defects has proven to be fully satisfactory. Bone tissue engineering (BTE) is the field of regenerative medicine (RM) that focuses on alternative treatment options for bone defects that will ideally address all the issues of the traditional techniques in treating large bone defects. However, current techniques of BTE is laborious and have their own shortcomings. More recently, 2D and 3D bone printing has been introduced to overcome most of the limitations of bone grafts and BTE. So far, results are extremely promising, setting new frontiers in the management of bone defects.

  1. Analysis of bone biopsies.

    Science.gov (United States)

    Goodrich, J A; Difiore, R J; Tippens, J K

    1983-11-01

    The orthopedic surgeon is frequently confronted with the decision of when to perform a bone biopsy and whether to do a needle biopsy or an open biopsy. Frequently consultations are received from other services requesting bone biopsies with questionable indications. The indications and contraindications for performing bone biopsies are discussed as well as advantages and disadvantages of either closed or open technique. Four selective cases are discussed with illustrations. The challenge of undiagnosed osseous lesions is best met by rational evaluation of each individual case and coordinated with the team effort of the primary care physician, surgeon, pathologist, and radiologist. The decision for either an open or closed biopsy technique must be based on the experience and skills of the surgeon and pathologist.

  2. Bone healing in 2016

    Science.gov (United States)

    Buza, John A.; Einhorn, Thomas

    2016-01-01

    Summary Delayed fracture healing and nonunion occurs in up to 5–10% of all fractures, and can present a challenging clinical scenario for the treating physician. Methods for the enhancement of skeletal repair may benefit patients that are at risk of, or have experienced, delayed healing or nonunion. These methods can be categorized into either physical stimulation therapies or biological therapies. Physical stimulation therapies include electrical stimulation, low-intensity pulsed ultrasonography, or extracorporeal shock wave therapy. Biological therapies can be further classified into local or systemic therapy based on the method of delivery. Local methods include autologous bone marrow, autologous bone graft, fibroblast growth factor-2, platelet-rich plasma, platelet-derived growth factor, and bone morphogenetic proteins. Systemic therapies include parathyroid hormone and bisphosphonates. This article reviews the current applications and supporting evidence for the use of these therapies in the enhancement of fracture healing. PMID:27920804

  3. Alveolar bone grafting

    Directory of Open Access Journals (Sweden)

    Lilja Jan

    2009-10-01

    Full Text Available In patients with cleft lip and palate, bone grafting in the mixed dentition in the residual alveolar cleft has become a well-established procedure. The main advantages can be summarised as follows: stabilisation of the maxillary arch; facilitation of eruption of the canine and sometimes facilitation of the lateral incisor eruption; providing bony support to the teeth adjacent to the cleft; raising the alar base of the nose; facilitation of closure of an oro-nasal fistula; making it possible to insert a titanium fixture in the grafted site and to obtain favourable periodontal conditions of the teeth within and adjacent to the cleft. The timing of the ABG surgery take into consideration not only eruption of the canine but also that of the lateral incisor, if present. The best time for bone grafting surgery is when a thin shell of bone still covers the soon erupting lateral incisor or canine tooth close to the cleft.

  4. Biochemical markers of bone turnover

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Deog Yoon [College of Medicine, Kyunghee Univ., Seoul (Korea, Republic of)

    1999-08-01

    Biochemical markers of bone turnover has received increasing attention over the past few years, because of the need for sensitivity and specific tool in the clinical investigation of osteoporosis. Bone markers should be unique to bone, reflect changes of bone less, and should be correlated with radiocalcium kinetics, histomorphometry, or changes in bone mass. The markers also should be useful in monitoring treatment efficacy. Although no bone marker has been established to meet all these criteria, currently osteocalcin and pyridinium crosslinks are the most efficient markers to assess the level of bone turnover in the menopausal and senile osteoporosis. Recently, N-terminal telopeptide (NTX), C-terminal telopeptide (CTX) and bone specific alkaline phosphatase are considered as new valid markers of bone turnover. Recent data suggest that CTX and free deoxypyridinoline could predict the subsequent risk of hip fracture of elderly women. Treatment of postmenopausal women with estrogen, calcitonin and bisphosphonates demonstrated rapid decrease of the levels of bone markers that correlated with the long-term increase of bone mass. Factors such as circadian rhythms, diet, age, sex, bone mass and renal function affect the results of biochemical markers and should be appropriately adjusted whenever possible. Each biochemical markers of bone turnover may have its own specific advantages and limitations. Recent advances in research will provide more sensitive and specific assays.

  5. Bone pathology inpsoriatic arthritis

    Directory of Open Access Journals (Sweden)

    V. V. Badokin

    2007-01-01

    Full Text Available Objective. To study different variants of osteolysis in pts with psoriatic arthritis (PA and to reveal their relationship with other clinico-radiological features of joint damage. Material and methods. 370 pts with definite PA having different variants of joint damage were included. Radiological examination of bones and joints (in some cases large picture frame was performed. Morphological evaluation of synovial biopsies was done in 34 pts with PA and 10 pts with rheumatoid arthritis (RA. Results. Different types of osteolysis were revealed in 80 (21,6% pts. Osteolytic variant of joint damage was present in 29 pts. 33 pts had acral, 48 — intra-articular osteolysis and 16 - true bone atrophy. Frequency and intensity of bone resorption were associated with severity of PA. Acral osteolysis correlated with arthritis of distal interphalangeal joints and onychodystrophy. Intra-articular osteolysis was most often present in distal interphalangeal joints of hands and metacarpophalangeal joints (39,6% and 41,7% respectively. Characteristic feature of PA was combination of prominent resorption with formation of bone ankylosis and periosteal reaction. Ankylosis was present in 33,3% of pts with intra-articular osteolysis and in 60% of pts with combination of different osteolysis variants. Systemic reaction of microcirculation in synovial biopsies was most prominent in osteolytic variant: marked thickening of capillary and venule basal membrane with high level of acid phosphatase, increased capillary and precapillary blood flow with stasis features, vascular lymphocyte and macrophage infiltration, productive vasculitis with annular wall thickening, thrombovasculitis and villi deep layer sclerosis. Conclusion. Different variants of osteolysis show bone involvement in PA. Acral and intra- articular osteolysis association with bone ankylosis and periostitis proves their common pathogenetic entity.

  6. Archival bone marrow samples

    DEFF Research Database (Denmark)

    Lund, Bendik; Najmi, Laeya A; Wesolowska-Andersen, Agata;

    2015-01-01

    AB Archival samples represent a significant potential for genetic studies, particularly in severe diseases with risk of lethal outcome, such as in cancer. In this pilot study, we aimed to evaluate the usability of archival bone marrow smears and biopsies for DNA extraction and purification, whole...... with samples stored for 4 to 10 years. Acceptable call rates for SNPs were detected for 7 of 42 archival samples. In conclusion, archival bone marrow samples are suitable for DNA extraction and multiple marker analysis, but WGA was less successful, especially when longer fragments were analyzed. Multiple SNP...

  7. Sex steroids and bone.

    Science.gov (United States)

    Manolagas, S C; Kousteni, S; Jilka, R L

    2002-01-01

    The adult skeleton is periodically remodeled by temporary anatomic structures that comprise juxtaposed osteoclast and osteoblast teams and replace old bone with new. Estrogens and androgens slow the rate of bone remodeling and protect against bone loss. Conversely, loss of estrogen leads to increased rate of remodeling and tilts the balance between bone resorption and formation in favor of the former. Studies from our group during the last 10 years have elucidated that estrogens and androgens decrease the number of remodeling cycles by attenuating the birth rate of osteoclasts and osteoblasts from their respective progenitors. These effects result, in part, from the transcriptional regulation of genes responsible for osteoclastogenesis and mesenchymal cell replication and/or differentiation and are exerted through interactions of the ligand-activated receptors with other transcription factors. However, increased remodeling alone cannot explain why loss of sex steroids tilts the balance of resorption and formation in favor of the former. Estrogens and androgens also exert effects on the lifespan of mature bone cells: pro-apoptotic effects on osteoclasts but anti-apoptotic effects on osteoblasts and osteocytes. These latter effects stem from a heretofore unexpected function of the classical "nuclear" sex steroid receptors outside the nucleus and result from activation of a Src/Shc/extracellular signal-regulated kinase signal transduction pathway probably within preassembled scaffolds called caveolae. Strikingly, estrogen receptor (ER) alpha or beta or the androgen receptor can transmit anti-apoptotic signals with similar efficiency, irrespective of whether the ligand is an estrogen or an androgen. More importantly, these nongenotropic, sex-nonspecific actions are mediated by the ligand-binding domain of the receptor and can be functionally dissociated from transcriptional activity with synthetic ligands. Taken together, these lines of evidence strongly suggest that

  8. Computerized geometric features of carpal bone for bone age estimation

    Institute of Scientific and Technical Information of China (English)

    Chi-Wen Hsieh; Tai-Lang Jong; Yi-Hong Chou; Chui-Mei Tiu

    2007-01-01

    Background Bone age development is one of the significant indicators depicting the growth status of children.However, bone age assessment is an heuristic and tedious work for pediatricians. We developed a computerized bone age estimation system based on the analysis of geometric features of carpal bones.Methods The geometric features of carpals were extracted and analyzed to judge the bone age of children by computerized shape and area description. Four classifiers, linear, nearest neighbor, back-propagation neural network,and radial basis function neural network, were adopted to categorize bone age. Principal component and discriminate analyses were employed to improve assorting accuracy.Results The hand X-ray films of 465 boys and 444 girls served as our database. The features were extracted from carpal bone images, including shape, area, and sequence. The proposed normalization area ratio method was effective in bone age classification by simulation. Besides, features statistics showed similar results between the standard of the Greulich and Pyle atlas and our database.Conclusions The bone area has a higher discriminating power to judge bone age. The ossification sequence of trapezium and trapezoid bones between Taiwanese and the atlas of the GP method is quite different. These results also indicate that carpal bone assessment with classification of neural networks can be correct and practical.

  9. Health Information Seeking and Cancer Screening Adherence Rates.

    Science.gov (United States)

    Shneyderman, Yuliya; Rutten, Lila J Finney; Arheart, Kristopher L; Byrne, Margaret M; Kornfeld, Julie; Schwartz, Seth J

    2016-03-01

    Effective screening tools are available for many of the top cancer killers in the USA. Searching for health information has previously been found to be associated with adhering to cancer screening guidelines, but Internet information seeking has not been examined separately. The current study examines the relationship between health and cancer Internet information seeking and adherence to cancer screening guidelines for breast, cervical, and colorectal cancer in a large nationally representative dataset. The current study was conducted using data from the Health Information National Trends Survey from 2003 and 2007. The study examined age-stratified models which correlated health and cancer information seeking with getting breast, cervical, and colorectal cancer screening on schedule, while controlling for several key variables. Internet health and cancer information seeking was positively associated with getting Pap screening on schedule, while information seeking from any sources was positively associated with getting colorectal screening on schedule. People who look for health or cancer information are more likely to get screened on schedule. Some groups of people, however, do not exhibit this relationship and, thus, may be more vulnerable to under-screening. These groups may benefit more from targeted interventions that attempt to engage people in their health care more actively.

  10. A non-linear model of information seeking behaviour

    Directory of Open Access Journals (Sweden)

    Allen E. Foster

    2005-01-01

    Full Text Available The results of a qualitative, naturalistic, study of information seeking behaviour are reported in this paper. The study applied the methods recommended by Lincoln and Guba for maximising credibility, transferability, dependability, and confirmability in data collection and analysis. Sampling combined purposive and snowball methods, and led to a final sample of 45 inter-disciplinary researchers from the University of Sheffield. In-depth semi-structured interviews were used to elicit detailed examples of information seeking. Coding of interview transcripts took place in multiple iterations over time and used Atlas-ti software to support the process. The results of the study are represented in a non-linear Model of Information Seeking Behaviour. The model describes three core processes (Opening, Orientation, and Consolidation and three levels of contextual interaction (Internal Context, External Context, and Cognitive Approach, each composed of several individual activities and attributes. The interactivity and shifts described by the model show information seeking to be non-linear, dynamic, holistic, and flowing. The paper concludes by describing the whole model of behaviours as analogous to an artist's palette, in which activities remain available throughout information seeking. A summary of key implications of the model and directions for further research are included.

  11. Motion sickness history, food neophobia, and sensation seeking.

    Science.gov (United States)

    Alley, Thomas R; Willet, Kathleen A; Muth, Eric R

    2006-06-01

    Motion sickness is believed to be caused by conflicting sensory signals, a situation that mimics the effects of ingesting certain toxins. Thus, one might suspect that individuals who have experienced a relatively high frequency of motion sickness may be particularly vigilant about avoiding anything that produces nausea, induding potentially nauseating toxins. Consequently, they may be more resistant to trying new foods, i.e., be more food neophobic, since unfamiliar foods can have unexpected adverse effects due to toxins or allergens. Likewise, many highly stimulating experiences can trigger motion sickness, so individuals who are more susceptible may be more prone to avoid such experiences, i.e., be less sensation seeking. Finally, it was expected that food neophobia would be more frequent in individuals low on sensation seeking tendencies. Self-reported motion sickness history in 308 adults (M= 18.8 yr.; SD = 1.6) was correlated with scores on the Arnett Inventory of Sensation Seeking and the Food Neophobia Scale. As predicted, greater history of motion sickness was associated with lower Sensation Seeking scores. Food Neophobia was not correlated with motion sickness history but, as expected, was negatively correlated (r = -.42) with scores on Sensation Seeking. Further research is recommended that measures actual sensitivity to motion sickness.

  12. Lamellar bone is an incremental tissue reconciling enamel rhythms, body size, and organismal life history.

    Science.gov (United States)

    Bromage, Timothy G; Lacruz, Rodrigo S; Hogg, Russell; Goldman, Haviva M; McFarlin, Shannon C; Warshaw, Johanna; Dirks, Wendy; Perez-Ochoa, Alejandro; Smolyar, Igor; Enlow, Donald H; Boyde, Alan

    2009-05-01

    Mammalian enamel formation is periodic, including fluctuations attributable to the daily biological clock as well as longer-period oscillations that enigmatically correlate with body mass. Because the scaling of bone mass to body mass is an axiom of vertebrate hard tissue biology, we consider that long-period enamel formation rhythms may reflect corresponding and heretofore unrecognized rhythms in bone growth. The principal aim of this study is to seek a rhythm in bone growth demonstrably related to enamel oscillatory development. Our analytical approach is based in morphology, using a variety of hard tissue microscopy techniques. We first ascertain the relationship among long-period enamel rhythms, the striae of Retzius, and body mass using a large sample of mammalian taxa. In addition, we test whether osteocyte lacuna density (a surrogate for rates of cell proliferation) in bone is correlated with mammalian body mass. Finally, using fluorescently labeled developing bone tissues, we investigate whether the bone lamella, a fundamental microanatomical unit of bone, relates to rhythmic enamel growth increments. Our results confirm a positive correlation between long-period enamel rhythms and body mass and a negative correlation between osteocyte density and body mass. We also confirm that lamellar bone is an incremental tissue, one lamella formed in the species-specific time dependency of striae of Retzius formation. We conclude by contextualizing our morphological research with a current understanding of autonomic regulatory control of the skeleton and body mass, suggesting a central contribution to the coordination of organismal life history and body mass.

  13. Vitamin D, Calcium, and Bone Health

    Science.gov (United States)

    ... in Balance › Vitamin D, Calcium, and Bone Health Vitamin D, Calcium, and Bone Health March 2012 Download ... also helps keep your bones strong. Why are vitamin D and calcium important to bone health? Vitamin ...

  14. Vitamin D, Calcium, and Bone Health

    Science.gov (United States)

    ... Bone Health Featured Resource Find an Endocrinologist Search Vitamin D, Calcium, and Bone Health March 2012 Download ... also helps keep your bones strong. Why are vitamin D and calcium important to bone health? Vitamin ...

  15. Bone X-Ray (Radiography)

    Medline Plus

    Full Text Available ... little information about muscles, tendons or joints. An MRI may be more useful in identifying bone and ... bones and the spinal cord can be evaluated). MRI can also detect subtle or occult fractures or ...

  16. Bone X-Ray (Radiography)

    Medline Plus

    Full Text Available ... reductions. look for injury, infection, arthritis , abnormal bone growths and bony changes seen in metabolic conditions. assist ... of the unaffected limb, or of a child's growth plate (where new bone is forming), for comparison ...

  17. Exercise, lifestyle, and your bones

    Science.gov (United States)

    Osteoporosis - exercise; Low bone density - exercise; Osteopenia - exercise ... your bones strong and lower your risk of osteoporosis and fractures as you get older. Before you begin an exercise program, talk with your health care provider if: ...

  18. Bone X-Ray (Radiography)

    Medline Plus

    Full Text Available ... the limitations of Bone X-ray (Radiography)? What is Bone X-ray (Radiography)? An x-ray (radiograph) ... diagnosis and disease management. top of page How is the procedure performed? The technologist, an individual specially ...

  19. Vitamin A and Bone Health

    Science.gov (United States)

    ... supported by your browser. Home Bone Basics Nutrition Vitamin A and Bone Health Publication available in: PDF ( ... Find More Information? For Your Information What Is Vitamin A? Vitamin A is a family of compounds ...

  20. Bone X-Ray (Radiography)

    Medline Plus

    Full Text Available ... Us News Physician Resources Professions Site Index A-Z X-ray (Radiography) - Bone Bone x-ray uses ... assess trauma patients in emergency departments. A CT scan can image complicated fractures, subtle fractures or dislocations. ...

  1. Bone X-Ray (Radiography)

    Medline Plus

    Full Text Available ... produce pictures of any bone in the body. It is commonly used to diagnose fractured bones or ... pass through most objects, including the body. Once it is carefully aimed at the part of the ...

  2. Bone X-Ray (Radiography)

    Medline Plus

    Full Text Available ... your doctor to view and assess bone fractures, injuries and joint abnormalities. This exam requires little to ... fusion, joint replacement and fracture reductions. look for injury, infection, arthritis , abnormal bone growths and bony changes ...

  3. Marijuana May Blunt Bone Health

    Science.gov (United States)

    ... page: https://medlineplus.gov/news/fullstory_161575.html Marijuana May Blunt Bone Health Study finds heavy users ... 19, 2016 WEDNESDAY, Oct. 19, 2016 (HealthDay News) -- Marijuana may be bad to the bone, a new ...

  4. Breast Cancer and Bone Loss

    Science.gov (United States)

    ... Menopause Map Featured Resource Find an Endocrinologist Search Breast Cancer and Bone Loss July 2010 Download PDFs English ... G. Komen Foundation What is the link between breast cancer and bone loss? Certain treatments for breast cancer ...

  5. Nanomaterials promise better bone repair

    Directory of Open Access Journals (Sweden)

    Qifei Wang

    2016-10-01

    Full Text Available Nanomaterials mimicking the nano-features of bones and offering unique smart functions are promising for better bone fracture repair. This review provides an overview of the current state-of-the-art research in developing and using nanomaterials for better bone fracture repair. This review begins with a brief introduction of bone fracture repair processes, then discusses the importance of vascularization, the role of growth factors in bone fracture repair, and the failure of bone fracture repair. Next, the review discusses the applications of nanomaterials for bone fracture repair, with a focus on the recent breakthroughs such as nanomaterials leading to precise immobilization of growth factors at the molecular level, promoting vascularization without the use of growth factors, and re-loading therapeutic agents after implantation. The review concludes with perspectives on challenges and future directions for developing nanomaterials for improved bone fracture repair.

  6. Bone X-Ray (Radiography)

    Medline Plus

    Full Text Available ... produce pictures of any bone in the body. It is commonly used to diagnose fractured bones or ... pass through most objects, including the body. Once it is carefully aimed at the part of the ...

  7. Implant fixation by bone ingrowth.

    Science.gov (United States)

    Kienapfel, H; Sprey, C; Wilke, A; Griss, P

    1999-04-01

    The term osseointegration referred originally to an intimate contact of bone tissue with the surface of a titanium implant; the term bone ingrowth refers to bone formation within an irregular (beads, wire mesh, casting voids, cut grooves) surface of an implant. The section dealing with the historical background describes the development of macroporous, microporous, and textured surfaces with an emphasis on the evolution of porous and textured metal surfaces. The principal requirements for osseointegration and bone ingrowth are systematically reviewed as follows: i) the physiology of osseointegration and bone ingrowth, including biomaterial biocompatibility with respect to cellular and matrix response at the interface; ii) the implant surface geometry characteristics; iii) implant micromotion and fixation modes; and iv) the implant-bone interface distances. Based on current methods of bone ingrowth assessment, this article comparatively reviews and discusses the results of experimental studies with the objective of determining local and systemic factors that enhance bone ingrowth fixation.

  8. Bone X-Ray (Radiography)

    Medline Plus

    Full Text Available ... your doctor to view and assess bone fractures, injuries and joint abnormalities. This exam requires little to ... fusion, joint replacement and fracture reductions. look for injury, infection, arthritis , abnormal bone growths and bony changes ...

  9. Transcutaneous Raman Spectroscopy of Bone

    Science.gov (United States)

    Maher, Jason R.

    Clinical diagnoses of bone health and fracture risk typically rely upon measurements of bone density or structure, but the strength of a bone is also dependent upon its chemical composition. One technology that has been used extensively in ex vivo, exposed-bone studies to measure the chemical composition of bone is Raman spectroscopy. This spectroscopic technique provides chemical information about a sample by probing its molecular vibrations. In the case of bone tissue, Raman spectra provide chemical information about both the inorganic mineral and organic matrix components, which each contribute to bone strength. To explore the relationship between bone strength and chemical composition, our laboratory has contributed to ex vivo, exposed-bone animal studies of rheumatoid arthritis, glucocorticoid-induced osteoporosis, and prolonged lead exposure. All of these studies suggest that Raman-based predictions of biomechanical strength may be more accurate than those produced by the clinically-used parameter of bone mineral density. The utility of Raman spectroscopy in ex vivo, exposed-bone studies has inspired attempts to perform bone spectroscopy transcutaneously. Although the results are promising, further advancements are necessary to make non-invasive, in vivo measurements of bone that are of sufficient quality to generate accurate predictions of fracture risk. In order to separate the signals from bone and soft tissue that contribute to a transcutaneous measurement, we developed an overconstrained extraction algorithm that is based upon fitting with spectral libraries derived from separately-acquired measurements of the underlying tissue components. This approach allows for accurate spectral unmixing despite the fact that similar chemical components (e.g., type I collagen) are present in both soft tissue and bone and was applied to experimental data in order to transcutaneously detect, to our knowledge for the first time, age- and disease-related spectral

  10. Bone healing around nanocrystalline hydroxyapatite, deproteinized bovine bone mineral, biphasic calcium phosphate, and autogenous bone in mandibular bone defects

    DEFF Research Database (Denmark)

    Broggini, Nina; Bosshardt, Dieter D; Jensen, Simon S

    2015-01-01

    The individual healing profile of a given bone substitute with respect to osteogenic potential and substitution rate must be considered when selecting adjunctive grafting materials for bone regeneration procedures. In this study, standardized mandibular defects in minipigs were filled with nanocr......The individual healing profile of a given bone substitute with respect to osteogenic potential and substitution rate must be considered when selecting adjunctive grafting materials for bone regeneration procedures. In this study, standardized mandibular defects in minipigs were filled...

  11. Chemical makeup of microdamaged bone differs from undamaged bone.

    Science.gov (United States)

    Ruppel, Meghan E; Burr, David B; Miller, Lisa M

    2006-08-01

    Microdamage naturally occurs in bone tissue as a result of cyclic loading placed on the body from normal daily activities. While it is usually repaired through the bone turnover process, accumulation of microdamage may result in reduced bone quality and increased fracture risk. It is unclear whether certain areas of bone are more susceptible to microdamage than others due to compositional differences. This study examines whether areas of microdamaged bone are chemically different than undamaged areas of bone. Bone samples (L3 vertebrae) were harvested from 15 dogs. Samples were stained with basic fuchsin, embedded in poly-methylmethacrylate, and cut into 5-microm-thick sections. Fuchsin staining was used to identify regions of microdamage, and synchrotron infrared microspectroscopic imaging was used to determine the local bone composition. Results showed that microdamaged areas of bone were chemically different than the surrounding undamaged areas. Specifically, the mineral stoichiometry was altered in microdamaged bone, where the carbonate/protein ratio and carbonate/phosphate ratio were significantly lower in areas of microdamage, and the acid phosphate content was higher. No differences were observed in tissue mineralization (phosphate/protein ratio) or crystallinity between the microdamaged and undamaged bone, indicating that the microdamaged regions of bone were not over-mineralized. The collagen cross-linking structure was also significantly different in microdamaged areas of bone, consistent with ruptured cross-links and reduced fracture resistance. All differences in composition had well-defined boundaries in the microcrack region, strongly suggesting that they occurred after microcrack formation. Even so, because microdamage results in an altered bone composition, an accumulation of microdamage might result in a long-term reduction in bone quality.

  12. Community Context and Men's Control-Seeking in Intimate Relationships.

    Science.gov (United States)

    Whitaker, M Pippin

    2015-01-01

    This study explores social-ecological influences on men's control-seeking in intimate relationships with women. Desire for control is central to the battered women's movement and is incorporated into intimate partner violence (IPV) prevention work. Recent IPV scholarship re-focuses on control, but the role of community contexts is underdeveloped. Community contexts have been associated with men's risk for IPV and evidence supports that social ecology facilitates IPV against women. Given the importance of the social ecology to control in IPV, this study examines community contexts that influence men's control-seeking of women partners. The sample comprised 2,342 in-state, male undergraduate students who completed a cross-sectional survey at a public university. Hypotheses were tested using hierarchical linear modeling. Results support a connection between county contexts and men's control-seeking toward women partners. Implications for IPV research and practice are discussed.

  13. Men's health in question: seeking assistance in primary health care

    Directory of Open Access Journals (Sweden)

    Max Moura de Oliveira

    2015-01-01

    Full Text Available The scope of this study was to analyze the socio-demographic profile, morbidity and frequency of seeking of adult men enrolled in a Family Doctor Program for health care in Niterói in the State of Rio de Janeiro. It is a cross-sectional study using secondary data, files and records of the first care visit in November 2003 through August 2009. The frequencies of the variables studied and the prevalence rates among those who sought and those who did not seek attention were calculated. Among the 323 men registered, 56% sought attendance. The main reason given for the first visit was a routine appointment. It was observed that 43 men were overweight, 26 were obese and 44 had abnormal blood pressure. The profile of the men who sought and those who did not seek care presented statistically significant differences (p

  14. Exploring information seeking behaviour in a digital museum context

    DEFF Research Database (Denmark)

    Skov, Mette; Ingwersen, Peter

    2008-01-01

    -aloud sessions. The data collected did not show exploratory behaviour to be predominant as expected. Rather analysis of data indicates a broad coverage of different types of needs. Finally, four main characteristics of virtual museum guests' information seeking behaviour were identified.......This paper describes the preliminary results of a case study of task-based interactive information seeking and retrieval behaviour of virtual museum visitors in context. The research described here is part of a larger study: this paper specifically looks at 1) leisure tasks/interests and derived...... information needs, and 2) main characteristics of virtual museum visitors' information seeking behaviour. Both quantitative and qualitative data were gathered from written enquiries to the museum, an online questionnaire and a user study of simulated interest tasks combined with retrospective think...

  15. Seeking professional help for nightmares: a representative study

    Directory of Open Access Journals (Sweden)

    Michael Schredl

    2013-12-01

    Full Text Available Background and Objectives: Nightmares are defined as disturbing mental experiences that generally occur during REM sleep and often result in awakening. Even though about 5% of the general population suffers from nightmares, little is known about seeking professional help in this patient group. Methods: A quota sample of 2019 participants representative for the German population was studied. Results: The findings indicate that every eighth person with frequent nightmares (cutoff: every other week or more often sought at one time of his/her life for professional help for coping with nightmares. Socio-demographic variables did not correlate with help-seeking behavior. Conclusions: Nightmares are an undertreated condition and future studies should aim at a more throughout understanding why nightmare sufferers rarely seek help for their condition.

  16. Bone X-Ray (Radiography)

    Medline Plus

    Full Text Available ... Resources Professions Site Index A-Z X-ray (Radiography) - Bone Bone x-ray uses a very small ... X-ray (Radiography)? What is Bone X-ray (Radiography)? An x-ray (radiograph) is a noninvasive medical ...

  17. Fibromatosis of bone in children

    Energy Technology Data Exchange (ETDEWEB)

    Capusten, B.M.; Azouz, E.M.; Rosman, M.A.

    1984-09-01

    Radiographs, computed tomograms, and radionuclide bone scans were obtained preoperatively in three children with fibromatosis involving the bones and soft tissues of the extremities. Two of the children had identical scar-like bone lesions of the proximal tibia, which, to the author's knowledge, have not been reported before in this disease. The lesions recurred in two children.

  18. Playing with bone and fat

    DEFF Research Database (Denmark)

    Gimble, Jeffrey M.; Zvonic, Sanjin; Floyd, Z. Elisabeth

    2006-01-01

    The relationship between bone and fat formation within the bone marrow microenvironment is complex and remains an area of active investigation. Classical in vitro and in vivo studies strongly support an inverse relationship between the commitment of bone marrow-derived mesenchymal stem cells...

  19. Bone regeneration during distraction osteogenesis

    NARCIS (Netherlands)

    Amir, L.R.; Everts, V.; Bronckers, A.L.J.J.

    2009-01-01

    Bone has the capacity to regenerate in response to injury. During distraction osteogenesis, the renewal of bone is enhanced by gradual stretching of the soft connec- tive tissues in the gap area between two separated bone segments. This procedure has received much clinical atten- tion as a way to co

  20. Gout: Value of bone scanning

    Energy Technology Data Exchange (ETDEWEB)

    Oliva, J.P.; Cardenas, R.; Bell, L.; Gonzalez Griego, J.

    1986-12-01

    11 male patients with gout were studied by means of bone scintigraphy with /sup 99m/TcMDP. This diagnostic method rendered possible the diagnosis of clinically or roentgenologically occult bone involvement. Bone scintigraphy may be useful procedure to monitor therapy of gout.