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Sample records for carbon-11 methionine pet

  1. A feasibility study on L-[1-carbon-11]tyrosine and L-[methyl-carbon-11]methionine to assess liver protein synthesis by PET

    NARCIS (Netherlands)

    Ishiwata, K; Enomoto, K; Elsinga, PH; Senda, M; Okazumi, SI; Isono, K; Paans, AMJ; Vaalburg, W

    1996-01-01

    We studied the potential of L-[1-C-11]tyrosine ([1-C-11]Tyr) and L-[methyl-C-11]methionine ([Me-C-11]Met) as tracers for measuring protein synthesis rate (PSR) in the liver by PET and proposed their metabolic models. Methods: In the liver and plasma of control and cycloheximide-treated mice injected

  2. Carbon-11-methionine positron emission tomography imaging of chordoma

    Energy Technology Data Exchange (ETDEWEB)

    Zhang, Hong [Department of Medical Imaging, National Institute of Radiological Sciences, Chiba (Japan); Department of Medical Imaging, Research Center Hospital for Charged Particle Therapy, National Institute of Radiological Sciences, 4-9-1, Anagawa, Inage-ku, 263-8555, Chiba (Japan); Yoshikawa, Kyosan; Tamura, Katsumi; Sagou, Kenji; Kandatsu, Susumu [Clinical Diagnosis Section, National Institute of Radiological Sciences, Chiba (Japan); Tian, Mei; Suhara, Tetsuya; Suzuki, Kazutoshi; Tanada, Shuji [Department of Medical Imaging, National Institute of Radiological Sciences, Chiba (Japan); Tsujii, Hirohiko [Research Center for Charged Particle Therapy, National Institute of Radiological Sciences, Chiba (Japan)

    2004-09-01

    Chordoma is a rare malignant bone tumor that arises from notochord remnants. This is the first trial to investigate the utility of {sup 11}C-methionine (MET) positron emission tomography (PET) in the imaging of chordoma before and after carbon-ion radiotherapy (CIRT). Fifteen patients with chordoma were investigated with MET-PET before and after CIRT and the findings analyzed visually and quantitatively. Tumor MET uptake was evaluated by tumor-to-nontumor ratio (T/N ratio). In 12 (80%) patients chordoma was clearly visible in the baseline MET-PET study with a mean T/N ratio of 3.3{+-}1.7. The MET uptake decreased significantly to 2.3{+-}1.4 after CIRT (P<0.05). A significant reduction in tumor MET uptake of 24% was observed after CIRT. Fourteen (93%) patients showed no local recurrence after CIRT with a median follow-up time of 20 months. This study has demonstrated that MET-PET is feasible for imaging of chordoma. MET-PET could provide important tumor metabolic information for the therapeutic monitoring of chordoma after CIRT. (orig.)

  3. Radiation dose estimates for carbon-11-labelled PET tracers

    International Nuclear Information System (INIS)

    Introduction: Carbon-11-labelled positron emission tomography (PET) tracers commonly used in biomedical research expose subjects to ionising radiation. Dosimetry is the measurement of radiation dose, but also commonly refers to the estimation of health risk associated with ionising radiation. This review describes radiation dosimetry of carbon-11-labelled molecules in the context of current PET research and the most widely used regulatory guidelines. Methods: A MEDLINE literature search returned 42 articles; 32 of these were based on human PET data dealing with radiation dosimetry of carbon-11 molecules. Radiation burden expressed as effective dose and maximum absorbed organ dose was compared between tracers. Results: All but one of the carbon-11-labelled PET tracers have an effective dose under 9 μSv/MBq, with a mean of 5.9 μSv/MBq. Data show that serial PET scans in a single subject are feasible for the majority of radiotracers. Conclusion: Although differing in approach, the two most widely used regulatory frameworks (those in the USA and the EU) do not differ substantially with regard to the maximum allowable injected activity per PET study. The predictive validity of animal dosimetry models is critically discussed in relation to human dosimetry. Finally, empirical PET data are related to human dose estimates based on homogenous distribution, generic models and maximum cumulated activities. Despite the contribution of these models to general risk estimation, human dosimetry studies are recommended where continued use of a new PET tracer is foreseen.

  4. A comparative study of carbon-11 methionine PET and Fluorine-18 fluorodeoxyglucose PET for the differentiation of benign lesion and low grade glioma%11碳-蛋氨酸与18氟-脱氧葡萄糖在脑良性病变及低级别胶质瘤诊断中的比较

    Institute of Scientific and Technical Information of China (English)

    王欣璐; 韩立新; 尹吉林; 王成; 姜丽莎; 谭思婷; 王伟民

    2015-01-01

    界的显示均明显优于18 F-FDG FDG,11 C-MET 还可检测和随访低级别胶质瘤(即惰性肿瘤)的生长情况,可为临床提供更多诊断、预后及治疗信息,因此,11 C-MET 可常规应用于脑内占位病变的显示,且其效果优于18 F-FDG.%Aim:As the study of Carbon-11 methionine (MET)and fluorine-18 fluorodeoxyglucose (FDG)in differentiating brain benign and low grade glioma was seldom.The aim of this study was to de-termine the effect of these two tracers for distinguishing two groups of patients and evaluating the extent of lesions.Methods:Both carbon-11 MET and fluorine-18 FDG have been used to evaluate brain benign and low grade glioma (LGG).MET positron emission tomography (PET)and FDG PET were all per-formed in 22 patients (5 brain benign lesions,17 low grade glioma WHO grade I and II)within one week for a single patient,Both MET and FDG uptake of the lesions were evaluated by a semiquantitative analy-sis using the standardized uptake value.The Tumor/normal brain uptake ratio (T/N ratio)were calculat-ed in two groups of patients.Results:MET uptake was not significantly different among these two groups (benign:1.59 ±0.28 and LGG:1.52 ±0.48).Similarily,FDG uptake was not significantly different among the two groups (benign:0.91 ±0.48 and 0.77 ±0.65)also.No significantly correlation was ob-served between MET uptake and FDG uptake.19 /22 hypermetabolization of patients were found in MET PET and 17 /22 hypometabolization of patients were found in FDG PET.The extents of increased MET uptake in 17 cases were larger than that of the increased FDG uptake.Conclusion:It is found that both MET and FDG are not useful for distinguishing with benign and LGG.MET was found to be highly useful for detecting benign and LGG,and for evaluating the extent of these lesions which were blurred in FDG PET.MET was also useful for monitoring the growth of LGG.In a word,MET was considered as routine examination for brain lesions.

  5. Carbon-11-labeled daunorubicin and verapamil for probing P-glycoprotein in tumors with PET

    NARCIS (Netherlands)

    Elsinga, PH; Franssen, EJF; Hendrikse, NH; Fluks, L; Weemaes, AMA; vanderGraaf, WTA; deVries, GE; Visser, GM; Vaalburg, W

    1996-01-01

    One of the mechanisms for multidrug resistance (MDR) of tumors is an overexpression of the P-glycoprotein (P-gp). The cytostatic agent daunorubicin and the modulator verapamil were labeled with C-11 to probe P-gp with PET. Methods: Carbon-11-daunorubicin was prepared from (CCH2N2)-C-11 with an aldeh

  6. Usefulness of {sup 11}C-methionine PET in the evaluation of brain lesions that are hypo- or isometabolic on {sup 18}F-FDG PET

    Energy Technology Data Exchange (ETDEWEB)

    Chung, J.-K.; Lee, Y.J.; Jeong, J.M. [Department of Nuclear Medicine, Seoul National University Hospital (Korea); Cancer Research Institute, Seoul National University College of Medicine, Seoul (Korea); Kim, Y.K.; Kim, S.; Yeo, J.S.; Lee, D.S.; Lee, M.C. [Department of Nuclear Medicine, Seoul National University Hospital (Korea); Paek, S.; Jung, H.W. [Department of Neurosurgery, Seoul National University College of Medicine, Seoul (Korea)

    2002-02-01

    The fact that some brain tumors show hypo- or isometabolism on fluorine-18 fluorodeoxyglucose positron emission tomography (FDG PET) has caused problems in the detection of primary or recurrent tumors and in the differentiation from benign lesions. We investigated the usefulness of carbon-11 methionine PET in characterizing brain lesions under these conditions. {sup 11}C-methionine PET was performed in 45 patients with brain lesions (in 34 for initial diagnosis and in 11 for detection of recurrence) that showed hypo- or isometabolism compared with normal brain tissue on FDG PET. Ten minutes after the injection of 555-740 MBq of {sup 11}C-methionine, attenuation-corrected brain images were obtained with a dedicated PET scanner. The brain lesions comprised 24 gliomas, five metastatic brain tumors, four meningiomas, two other brain tumors and ten benign lesions (including three cases of cysticercosis, two cases of radiation necrosis, one tuberculous granuloma, one hemangioma, one benign cyst, and one organizing infarction). Proliferative activity was measured using the Ki-67 immunostaining method in glioma tissues. Thirty-one of 35 brain tumors (89% sensitivity) showed increased {sup 11}C-methionine uptake despite iso- or hypometabolism on FDG PET. By contrast, all ten benign lesions showed decreased or normal {sup 11}C-methionine uptake (100% specificity). Twenty-two of 24 gliomas (92%) showed increased {sup 11}C-methionine uptake, the extent and degree of which exceeded {sup 18}F-FDG uptake, and the {sup 11}C-methionine uptake correlated with the proliferation index (r=0.67). The mean ({+-}SD) uptake ratios of glioma to normal brain on FDG and {sup 11}C-methionine PET were 0.92{+-}0.34 and 2.54{+-}1.25, respectively. All metastatic tumors except one showed intense {sup 11}C-methionine uptake in the entire tumor or in the peripheral margin of the tumor. In meningiomas, {sup 11}C-methionine uptake showed a variable increase. In conclusion, brain lesions that show hypo

  7. Carbon-11 radiolabeling of iron-oxide nanoparticles for dual-modality PET/MR imaging

    Science.gov (United States)

    Sharma, Ramesh; Xu, Youwen; Kim, Sung Won; Schueller, Michael J.; Alexoff, David; Smith, S. David; Wang, Wei; Schlyer, David

    2013-07-01

    Dual-modality imaging, using Magnetic Resonance Imaging (MRI) and Positron Emission Tomography (PET) simultaneously, is a powerful tool to gain valuable information correlating structure with function in biomedicine. The advantage of this dual approach is that the strengths of one modality can balance the weaknesses of the other. However, success of this technique requires developing imaging probes suitable for both. Here, we report on the development of a nanoparticle labeling procedure via covalent bonding with carbon-11 PET isotope. Carbon-11 in the form of [11C]methyl iodide was used as a methylation agent to react with carboxylic acid (-COOH) and amine (-NH2) functional groups of ligands bound to the nanoparticles (NPs). The surface coating ligands present on superparamagnetic iron-oxide nanoparticles (SPIO NPs) were radiolabeled to achieve dual-modality PET/MR imaging capabilities. The proof-of-concept dual-modality PET/MR imaging using the radiolabeled SPIO NPs was demonstrated in an in vivo experiment.Dual-modality imaging, using Magnetic Resonance Imaging (MRI) and Positron Emission Tomography (PET) simultaneously, is a powerful tool to gain valuable information correlating structure with function in biomedicine. The advantage of this dual approach is that the strengths of one modality can balance the weaknesses of the other. However, success of this technique requires developing imaging probes suitable for both. Here, we report on the development of a nanoparticle labeling procedure via covalent bonding with carbon-11 PET isotope. Carbon-11 in the form of [11C]methyl iodide was used as a methylation agent to react with carboxylic acid (-COOH) and amine (-NH2) functional groups of ligands bound to the nanoparticles (NPs). The surface coating ligands present on superparamagnetic iron-oxide nanoparticles (SPIO NPs) were radiolabeled to achieve dual-modality PET/MR imaging capabilities. The proof-of-concept dual-modality PET/MR imaging using the radiolabeled

  8. [11C] Methionine as PET radiopharmaceutical produced at CDTN/CNEN

    Energy Technology Data Exchange (ETDEWEB)

    Silveira, Marina B.; Ferreira, Soraya Z.; Carvalho, Tiago F.; Silva, Juliana B. da, E-mail: mbs@cdtn.br [Centro de Desenvolvimento da Tecnologia Nuclear (CDTN/CNEN-MG), Belo Horizonte, MG (Brazil). Unidade de Pesquisa e Producao de Radiofarmacos

    2013-07-01

    Carbon-11 ({sup 11}C) is an attractive radionuclide used in positron emission tomography (PET) since carbon is a ubiquitous element in biomolecules. Positron emitter-labeled amino acids are being widely used as indicators of tumor activity due to enhanced expression of amino acid transporter systems in cancer cells. L-[Methyl-({sup 11}C)] Methionine or [{sup 11}C]Methionine is being used in neuro-oncology and, unlike 2-[{sup 18}F]fluoro-2-deoxy-D-glucose ({sup 18}FDG), gives more contrast images and improves brain tumor diagnosis. The aim of this work was to develop the synthesis and quality control of [{sup 11}C]Methionine at the Radiopharmaceuticals Research and Production Facility (UPPR) of CDTN/CNEN. The synthesis of [{sup 11}C] Methionine was performed using two Sep-Pak tC18 plus cartridges one as solid support for the {sup 11}C-methylation of the precursor L-homocysteine thiolactone hydrochloride and another for purification. The pH, radionuclidic identity and purity, residual solvents, radiochemical and chemical purity of the final product were evaluated as described on the European Pharmacopoeia 7.0 monograph. Total synthesis time was 18 minutes, the radiochemical yield was approximately 15% (non-decay corrected) and radiochemical purity was greater than 95%. [{sup 11}C]Methionine was successfully synthesized at CDTN using the described procedures and complied with quality requirements. Due to the rapid growth of oncologic PET scans in last decade, {sup 11}C labelling holds great promises in the next few years with the application of other tracers beyond {sup 18}FDG. This pioneering work of UPPR/CDTN represents a response to the demands of a growing nuclear medicine in the country focused on achieving better diagnostic imaging. (author)

  9. Synthesis of n. c. a. PET-radiotracers with carbon-11. Zur Synthese traegerarme PET-Radiotracer mit Kohlenstoff-11

    Energy Technology Data Exchange (ETDEWEB)

    Schirbel, A.

    1998-11-01

    Carbon-11 offers the unique possibility of authentic labelling of molecules as radioindicators for non invasive and quantitative determination of physiological functions via positron emission tomography (PET). Therefore, the goal of this thesis was to synthesize of different n.c.a. [sup 11]C-labelled pharmaceuticals for in vivo distribution studies with PET. For the determination of the pharmacokinetics of [1-[sup 11]C]acetate in porcine myocardium during prolonged ischemia, n.c.a. [1-[sup 11]C]acetate was synthesized via carboxylation of methylmagnesium bromide with in target produced n.c.a. [[sup 11]C]CO[sub 2] with a radiochemical yield (RCY) of 68 [+-] 7%. The fast (18 min) and reliable radiosynthesis allowed for repeated tracer administration at short intervals (<20 min). In order to study the pharmacokinetics and metabolism of acetylsalicylic acid (Aspirin[sup R]c) in humans, [1-[sup 11]C]acetylsalicylic acid, acetyl-[carboxy-[sup 11]C]salicylic acid and [carboxy-[sup 11]C]salicylic acid were prepared. N.c.a. [1-[sup 11]C]acetylsalicylic acid was synthesized via the reaction of [1-[sup 11]C]acetylchloride with salicylic acid salts. The use of the silver salt proved to be superior to the sodium salt and resulted in radiochemical yields of 32 [+-] 5%. Base-line (clean) separation of the labelled product was achieved using radio-HPLC. With regard to the preparation of n.c.a. [carboxy-[sup 11]C]salicylic acid, several protected and unprotected phenol derivates were metallated and subsequently carboxylated using n.c.a. [[sup 11]C]CO[sub 2]. Best results (87 [+-] 3% RCY) could be achieved with 2-(methoxymethoxy)-phenylmagnesium iodide as a precursor and subsequent quantitative cleavage of the MOM-group. Acetylation of n.c.a. [carboxy-[sup 11]C]salicylic acid to acetyl-[carboxy-[sup 11]C]salicylic acid was performed using acetylchloride in CH[sub 2]Cl[sub 2] with a radiochemical yield of 65 [+-] 4%. (orig.)

  10. Carbon-11 labelled ketamine-synthesis, distribution in mice and PET studies in baboons

    Energy Technology Data Exchange (ETDEWEB)

    Shiue, C.-Y.; Vallabhahosula, Shankar; Wolf, Alfred P.; Dewey, Stephen L.; Fowler, Joanna S.; Schlyer, David J.; Arnett, Carroll D.; Zhou Yiguo

    1997-02-01

    No-carrier-added (NCA)[{sup 11}C]({+-})-ketamine (2a) and its enantiomers (+)-2b and (-)-2c were synthesized by methylation of the corresponding norketamine (1a-c) with [{sup 11}C]H{sub 3}I in an overall radiochemical yield of 20% (EOB) with specific activities of 0.35-0.45 Ci/{mu}mole at EOB in a synthesis time of 40 min from EOB. Compound 2a was metabolized rapidly in mouse brain and labeled metabolites appeared in baboon plasma. PET studies of compounds 2a-c in a baboon showed that influx of compounds 2a-c into the brain was high for the first few min but radioactivity then declined rapidly. Although the retention of radioactivity in the baboon striatum was not significantly different for 2a-c 20 min post-injection, graphical analysis of time-activity data for each enantiomer and for the racemate in baboon striatum suggested that (+)-ketamine may interact with receptors slightly more effectively than its (-)-enantiomer or racemate. However, due to its rapid metabolism in the brain and a similar uptake in the striatum and cerebellum, [{sup 11}C]ketamine may not be an ideal tracer for studying NMDA receptor with PET.

  11. Carbon-11 epidepride: a suitable radioligand for PET investigation of striatal and extrastriatal dopamine D2 receptors.

    Science.gov (United States)

    Langer, O; Halldin, C; Dollé, F; Swahn, C G; Olsson, H; Karlsson, P; Hall, H; Sandell, J; Lundkvist, C; Vaufrey, F; Loc'h, C; Crouzel, C; Mazière, B; Farde, L

    1999-07-01

    Epidepride [(S)-(-)-N-([1-ethyl-2-pyrrolidinyl]methyl)-5-iodo-2,3-dimethoxybenza mide] binds with a picomolar affinity (Ki = 24 pM) to the dopamine D2 receptor. Iodine-123-labeled epidepride has been used previously to study striatal and extrastriatal dopamine D2 receptors with single photon emission computed tomography (SPECT). Our aim was to label epidepride with carbon-11 for comparative quantitative studies between positron emission tomography (PET) and SPECT. Epidepride was synthesized from its bromo-analogue FLB 457 via the corresponding trimethyl-tin derivative. In an alternative synthetic pathway, the corresponding substituted benzoic acid was reacted with the optically pure aminomethylpyrrolidine-derivative. Demethylation of epidepride gave the desmethyl-derivative, which was reacted with [11C]methyl triflate. Total radiochemical yield was 40-50% within a total synthesis time of 30 min. The specific radioactivity at the end of synthesis was 37-111 GBq/micromol (1,000-3,000 Ci/mmol). Human postmortem whole-hemisphere autoradiography demonstrated dense binding in the caudate putamen, and also in extrastriatal areas such as the thalamus and the neocortex. The binding was inhibited by unlabeled raclopride. PET studies in a cynomolgus monkey demonstrated high uptake in the striatum and in several extrastriatal regions. At 90 min after injection, uptake in the striatum, thalamus and neocortex was about 11, 4, and 2 times higher than in the cerebellum, respectively. Pretreatment experiment with unlabeled raclopride (1 mg/kg) inhibited 50-70% of [11C]epidepride binding. The fraction of unchanged [11C]epidepride in monkey plasma determined by a gradient high performance liquid chromatography (HPLC) method was about 30% of the total radioactivity at 30 min after injection of [11C]epidepride. The availability of [11C]epidepride allows the PET-verification of the data obtained from quantitation studies with SPECT. PMID:10473189

  12. Carbon-11 epidepride: a suitable radioligand for PET investigation of striatal and extrastriatal dopamine D2 receptors

    International Nuclear Information System (INIS)

    Epidepride {(S)-(-)-N-([1-ethyl-2-pyrrolidinyl]methyl)-5-iodo-2,3-dimethoxybenzamide} binds with a picomolar affinity (Ki=24 pM) to the dopamine D2 receptor. Iodine-123-labeled epidepride has been used previously to study striatal and extrastriatal dopamine D2 receptors with single photon emission computed tomography (SPECT). Our aim was to label epidepride with carbon-11 for comparative quantitative studies between positron emission tomography (PET) and SPECT. Epidepride was synthesized from its bromo-analogue FLB 457 via the corresponding trimethyl-tin derivative. In an alternative synthetic pathway, the corresponding substituted benzoic acid was reacted with the optically pure aminomethylpyrrolidine-derivative. Demethylation of epidepride gave the desmethyl-derivative, which was reacted with [11C]methyl triflate. Total radiochemical yield was 40-50% within a total synthesis time of 30 min. The specific radioactivity at the end of synthesis was 37-111 GBq/μmol (1,000-3,000 Ci/mmol). Human postmortem whole-hemisphere autoradiography demonstrated dense binding in the caudate putamen, and also in extrastriatal areas such as the thalamus and the neocortex. The binding was inhibited by unlabeled raclopride. PET studies in a cynomolgus monkey demonstrated high uptake in the striatum and in several extrastriatal regions. At 90 min after injection, uptake in the striatum, thalamus and neocortex was about 11, 4, and 2 times higher than in the cerebellum, respectively. Pretreatment experiment with unlabeled raclopride (1 mg/kg) inhibited 50-70% of [11C]epidepride binding. The fraction of unchanged [11C]epidepride in monkey plasma determined by a gradient high performance liquid chromatography (HPLC) method was about 30% of the total radioactivity at 30 min after injection of [11C]epidepride. The availability of [11C]epidepride allows the PET-verification of the data obtained from quantitation studies with SPECT.

  13. Development of rapid multistep carbon-11 radiosynthesis of the myeloperoxidase inhibitor AZD3241 to assess brain exposure by PET microdosing

    International Nuclear Information System (INIS)

    Introduction: The myeloperoxidase inhibitor AZD3241 has been selected as a candidate drug currently being developed to delay progression in patients with neurodegenerative brain disorders. Part of the decision tree for translation of AZD3241 into clinical studies included the need for assessment of brain exposure in non-human primates by PET microdosing. For that purpose a rapid multistep method for 11C-labeling of AZD3241 was developed. Methods: AZD3241 was labeled in the thio-carbonyl position starting from [11C]potassium cyanide in a 4-step procedure using microwave assisted heating. In the first step [11C]potassium cyanide was converted to [11C]potassium thiocyanate followed by reaction with benzoyl chloride to yield benzoyl [11C]isothiocyanate. The benzoyl [11C]isothiocyanate was subsequently reacted with the precursor ethyl 3-(2-isopropoxyethylamino)-1H-pyrrole-2-carboxylate and the formed intermediate underwent a base catalyzed cyclization to obtain [11C]AZD3241 in the final step. To assess [11C]AZD3241 brain exposure PET measurements were performed in three cynomolgus monkeys. Results: [11C]AZD3241 was produced in good and reproducible radiochemical yield 710 ± 294 MBq (mean ± SD, n = 7). Total time of synthesis was 60 min from end of bombardment. The specific radioactivity was 9 ± 4 GBq/μmol and the radiochemical purity was > 98%. Following iv administration of [11C]AZD3241 there was a rapid presence of radioactivity in brain in each of the three monkeys. The distribution of [11C]AZD3241 to brain was fast and a Cmax of 1.9 to 2.6% of the injected radioactivity was observed within 1.5 min. [11C]AZD3241 was homogeneously distributed in brain. Conclusion: The MPO inhibitor AZD3241 was successfully labeled with carbon-11 in a challenging 4-step procedure in good radiochemical yield allowing PET microdosing studies in cynomolgus monkey. [11C]AZD3241 rapidly entered brain and confirmed adequate brain exposure to support translation of AZD3241 to phase 2a

  14. Carbon-11 epidepride: a suitable radioligand for PET investigation of striatal and extrastriatal dopamine D{sub 2} receptors

    Energy Technology Data Exchange (ETDEWEB)

    Langer, Oliver; Halldin, Christer E-mail: christer.halldin@neuro.ks.se; Dolle, Frederic; Swahn, Carl-Gunnar; Olsson, Hans; Lundkvist, Per Karlsson; Hall, Haakan; Sandell, Johan; Vaufrey, Camilla; Loc' h, Christian; Franzoise; Crouzel, Christian; Maziere, Bernard; Farde, Lars

    1999-07-01

    Epidepride {l_brace}(S)-(-)-N-([1-ethyl-2-pyrrolidinyl]methyl)-5-iodo-2,3-dimethoxybenzamide= {r_brace} binds with a picomolar affinity (K{sub i}=24 pM) to the dopamine D{sub 2} receptor. Iodine-123-labeled epidepride has been used previously to study striatal and extrastriatal dopamine D{sub 2} receptors with single photon emission computed tomography (SPECT). Our aim was to label epidepride with carbon-11 for comparative quantitative studies between positron emission tomography (PET) and SPECT. Epidepride was synthesized from its bromo-analogue FLB 457 via the corresponding trimethyl-tin derivative. In an alternative synthetic pathway, the corresponding substituted benzoic acid was reacted with the optically pure aminomethylpyrrolidine-derivative. Demethylation of epidepride gave the desmethyl-derivative, which was reacted with [{sup 11}C]methyl triflate. Total radiochemical yield was 40-50% within a total synthesis time of 30 min. The specific radioactivity at the end of synthesis was 37-111 GBq/{mu}mol (1,000-3,000 Ci/mmol). Human postmortem whole-hemisphere autoradiography demonstrated dense binding in the caudate putamen, and also in extrastriatal areas such as the thalamus and the neocortex. The binding was inhibited by unlabeled raclopride. PET studies in a cynomolgus monkey demonstrated high uptake in the striatum and in several extrastriatal regions. At 90 min after injection, uptake in the striatum, thalamus and neocortex was about 11, 4, and 2 times higher than in the cerebellum, respectively. Pretreatment experiment with unlabeled raclopride (1 mg/kg) inhibited 50-70% of [{sup 11}C]epidepride binding. The fraction of unchanged [{sup 11}C]epidepride in monkey plasma determined by a gradient high performance liquid chromatography (HPLC) method was about 30% of the total radioactivity at 30 min after injection of [{sup 11}C]epidepride. The availability of [{sup 11}C]epidepride allows the PET-verification of the data obtained from quantitation studies with

  15. Usefulness of {sup 11}C-methionine PET in evaluation of brain lesions with hypo- or isometabolism on {sup 18}F-FDG PET

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Y. K.; Chung, J. K.; Yeo, J. S.; Lee, D. S.; Jeong, H. W.; Lee, M. C. [College of Medicine, Seoul National Univ., Seoul (Korea, Republic of)

    2000-07-01

    Because some brain tumors show iso-or hypometabolism on {sup 18}F-FDG PET, there have been problems in detection of primary or recurrent tumor and in differentiation from benign lesion with {sup 18}F-FDG PET. We investigated the usefulness of {sup 11}C-methionine PET in characterizing brain lesions in these conditions. In 34 patients with brain lesions (27 for initial diagnosis, 7 for detecting recurrence ) who showed hypo- or isometabolism compared to normal brain tissue on {sup 18}F-FDG PET, we performed {sup 11}C-methionine PET. Five minutes after injection of 550 MBq {sup 11}C-methionine, attenuation corrected brain images were obtained with a dedicated PET scanner. Brain lesions were 18 gliomas, 4 metastatic brain tumors, 2 meningiomas, 1 mixed germ cell tumor and 3 benign tumors and 6 non-tumorous lesions (3 neurocysticercosis, 2 meningiomas, 1 mixed germ cell tumor and 3 benign tumors and 6 non-tumorous lesions (3 neurocysticercosis, 2 tumor necrosis, 1 granuloma). To find the correlation between methione uptake and proliferation activity, Ki 67 proliferation Index in 8 patients or Proliferation index (P1=G2+M+S/total cycle) using DNA flow cytometry in 10 patients were obtained. Of 25 tumorous lesions without definitive hypermetabolism on {sup 18}F-FDG PET, all except two glioma (92%) showed moderate to high uptake in entire or thick peripheral tumor uptake in {sup 11}C-methionine PET. The uptake ratio of tumor to normal brain in {sup 18}F-FDG and {sup 11}C-methionine PET were 0.96 {+-}0.32 and 2.43 {+-} 1.26, respectively. Nine benign lesions with hypo- or isometabolism on {sup 18}F-FDG PET were also no significantly increased {sup 11}C-methionine uptake. {sup 11}C-methionine uptake and proliferation activity were correlated with Ki 67 index or PI (r=0.6). Two glioma shown no increased {sup 11}C-methionine uptake had low proliferative activity (Ki 67 < 1%). {sup 11}C-methionin PET could detect brain tumors and differentiate brain lesions with high

  16. Pre-operative localisation of hyperfunctional parathyroid tissue with {sup 11}C-methionine PET

    Energy Technology Data Exchange (ETDEWEB)

    Otto, D.; Boerner, A.R.; Hofmann, M.; Brunkhorst, T.; Meyer, G.J.; Petrich, T.; Knapp, W.H. [Hannover University Medical School, Department of Nuclear Medicine, Hannover (Germany); Scheumann, G.F. [Hannover University Medical School, Department of Visceral and Transplant Surgery, Hannover (Germany)

    2004-10-01

    Previous studies have shown high sensitivity of positron emission tomography (PET) with {sup 11}C-methionine in the pre-operative localisation of parathyroid adenoma and hyperplasia. Nonetheless, in secondary and tertiary hyperparathyroidism (HPT) and in patients with recurrent disease, pre-operative localisation of adenomatous (PTA) or hyperplastic tissue is still a problem with all available methods. The aim of this study was to define the optimal imaging protocol and to compare the diagnostic value of {sup 11}C-methionine PET and {sup 99m}Tc-methoxyisobutylisonitrile (MIBI) single-photon emission computed tomography (SPECT): in particular, we wished to define the benefit of {sup 11}C-methionine in those patients with inconclusive or negative conventional imaging. Thirty highly pre-selected patients with HPT were enrolled. Sixteen patients had primary HPT, 12 patients had secondary HPT, and two patients had recurrences of parathyroid carcinomas. All patients had ultrasound of the neck, dual-phase scintigraphy with {sup 99m}Tc-MIBI and PET with {sup 11}C-methionine. SUV{sub parathyroid}/SUV{sub cervical} {sub soft} {sub tissue} (target-to-background) and SUV{sub parathyroid} {sub tissue}/SUV{sub thyroid} {sub tissue} (target-to-non-target) ratios were calculated. After surgery, histology of specimens was obtained in all patients but one. In 12 patients with secondary or tertiary HPT, 36 hyperplastic parathyroid glands were histologically verified. Twenty-five of 36 lesions (69%) were detected with {sup 11}C-methionine PET and 17 (47%) with {sup 99m}Tc-MIBI scintigraphy. PET studies were positive in 17/18 (94%) cases in which HPT was related to adenomas or carcinomas. {sup 99m}Tc-MIBI scintigraphy/SPECT yielded pathological lesions in 9/18 cases (50%). All eight atypical localisations of parathyroid glands were detected with PET but only six of the eight were detected with {sup 99m}Tc-MIBI scintigraphy/SPECT. In 10/11 patients with recurrent HPT and non

  17. Whole-body pharmacokinetics of HDAC inhibitor drugs, butyric acid, valproic acid and 4-phenylbutyric acid measured with carbon-11 labeled analogs by PET

    International Nuclear Information System (INIS)

    The fatty acids, n-butyric acid (BA), 4-phenylbutyric acid (PBA) and valproic acid (VPA, 2-propylpentanoic acid) have been used for many years in the treatment of a variety of CNS and peripheral organ diseases including cancer. New information that these drugs alter epigenetic processes through their inhibition of histone deacetylases (HDACs) has renewed interest in their biodistribution and pharmacokinetics and the relationship of these properties to their therapeutic and side effect profiles. In order to determine the pharmacokinetics and biodistribution of these drugs in primates, we synthesized their carbon-11 labeled analogues and performed dynamic positron emission tomography (PET) in six female baboons over 90 min. The carbon-11 labeled carboxylic acids were prepared by using 11CO2 and the appropriate Grignard reagents. [11C]BA was metabolized rapidly (only 20% of the total carbon-11 in plasma was parent compound at 5 min post injection) whereas for VPA and PBA 98% and 85% of the radioactivity were the unmetabolized compound at 30 min after their administration respectively. The brain uptake of all three carboxylic acids was very low ( VPA > PBA), which is consistent with the need for very high doses for therapeutic efficacy. Most of the radioactivity was excreted through the kidneys and accumulated in the bladder. However, the organ biodistribution between the drugs differed. [11C]BA showed relatively high uptake in spleen and pancreas whereas [11C]PBA showed high uptake in liver and heart. Notably, [11C]VPA showed exceptionally high heart uptake possibly due to its involvement in lipid metabolism. The unique biodistribution of each of these drugs may be of relevance in understanding their therapeutic and side effect profile including their teratogenic effects

  18. Simple synthesis of carbon-11-labeled chromen-4-one derivatives as new potential PET agents for imaging of DNA-dependent protein kinase (DNA-PK) in cancer

    International Nuclear Information System (INIS)

    Carbon-11-labeled chromen-4-one derivatives were synthesized as new potential PET agents for imaging of DNA repair enzyme DNA-dependent protein kinase (DNA-PK) in cancer. The target tracers, X-[11C]methoxy-2-morpholino-4H-chromen-4-ones (X=8, 7, 6, 5; [11C]4a–d), were prepared from their corresponding precursors, X-hydroxy-2-morpholino-4H-chromen-4-ones (X=8, 7, 6, 5; 5a–d), with [11C]CH3OTf through O-[11C]methylation and isolated by a simplified solid-phase extraction (SPE) method using a C-18 Sep-Pak Plus cartridge. The radiochemical yields decay corrected to end of bombardment (EOB), from [11C]CO2, were 40–60%. The specific activity at end of synthesis (EOS) was 185–370 GBq/μmol. - Highlights: ► New chromen-4-one derivatives were synthesized. ► New carbon-11-labeled chromen-4-one derivatives were synthesized. ► Simple solid-phase extraction (SPE) method was employed in radiosynthesis.

  19. Adding {sup 11}C-methionine PET to the EORTC prognostic factors in grade 2 gliomas

    Energy Technology Data Exchange (ETDEWEB)

    Smits, A.; Westerberg, E.; Ribom, D. [University Hospital, Department of Neuroscience, Neurology, Uppsala (Sweden)

    2008-01-15

    The management of adult patients with grade 2 gliomas remains a challenge for the clinical neuro-oncologist. Several clinical prognostic factors appear to be as important as treatment factors in determining outcome. From the European Organisation for Research and Treatment of Cancer (EORTC) trials 22844 and 22845, a prognostic scoring system has been proposed based on the presence of unfavourable prognostic factors. The aim of the present study was to assess the additional prognostic value of {sup 11}C-methionine (MET) measured by positron emission tomography (PET) in the setting of the EORTC prognostic scoring system. In this retrospective review, 129 patients with supratentorial grade 2 gliomas were subjected to a PET study as part of the pre-treatment tumour investigation. One hundred and three cases were classified as low-risk patients (0-2 unfavourable factors) and 26 cases as high-risk patients (3-5 unfavourable factors) according to the EORTC criteria. MET PET was evaluated as an extra prognostic factor in both groups. In the high-risk group, patients with high MET uptake had a worse outcome than patients with low MET uptake. A similar trend was found for the low-risk group in patients with oligodendrocytic tumours. Our findings further strengthen the role of MET PET as an important prognostic tool in the management of this group of patients. (orig.)

  20. Volumetry of [11C]-methionine PET uptake and MRI contrast enhancement in patients with recurrent glioblastoma multiforme

    OpenAIRE

    Galldiks, Norbert; Ullrich, Roland; Schroeter, Michael; Fink, Gereon R.; Kracht, Lutz W.

    2009-01-01

    Purpose We investigated the relationship between three-dimensional volumetric data of the metabolically active tumour volume assessed using [11C]-methionine positron emission tomography (MET-PET) and the area of gadolinium-diethylenetriaminepentaacetic acid (Gd-DTPA) enhancement assessed using magnetic resonance imaging (MRI) in patients with recurrent glioblastoma (GBM). Material and methods MET-PET and contrast-enhanced MRI with Gd-DTPA were performed in 12 uniformly pretreated patients wit...

  1. Synthesis of carbon-11 labelled SCH 39166, a new selective dopamine D-1 receptor ligand, and preliminary PET investigations

    Energy Technology Data Exchange (ETDEWEB)

    Halldin, Christer; Farde, Lars; Sedvall, Goeran (Karolinska Hospital, Stockholm (Sweden). Dept. of Psychiatry and Psychology); Barnett, Allen (Schering-Plough Corp., Bloomfield, NJ (USA))

    1991-01-01

    SCH 39166 ((-)-trans-6,7,7a,8,9,13b-hexahydro-3-chloro-2-hydroxy-N-methyl-5H-benzo(d)naphtho-(2,1-b)azepine ) is a new more selective dopamine D-1 receptor antagonist than the widely used SCH 23390. ({sup 11}C)SCH 39166 was prepared by N-methylation of the desmethyl compound SCH 40853 ((-)-trans-6,7,7a,8,9,13b-hexahydro-3-chloro-2-hydroxy-5H-benzo(d)naphtho -(2,1-b)azepine) with ({sup 11}C)methyl iodide. Reaction in acetone with subsequent straight-phase semi-preparative HPLC resulted in 20-30% radiochemical yield (from EOB and decay-corrected) with a total synthesis time of 35-40 min and a radiochemical purity >99%. The specific activity obtained at EOS was about 1500 Ci/mmol (55 GBq/{mu}mol). ({sup 11}C)SCH 39166 was injected into a Cynomolgus monkey. PET-analysis demonstrated accumulation in the striatum, a region known to have a high density of dopamine D-1 receptors. In a displacement experiment, radioactivity in the striatum was markedly reduced after injection of 6 mg unlabelled SCH 23390, thus demonstrating the specificity and reversibility of ({sup 11}C)SCH 39166 binding to dopamine D-1 receptors. (author).

  2. Comparative evaluation of 11C methionine (MET-PET) and 18F flurodeoxyglucose (FDG) PET/CT for detection of recurrent brain tumors

    International Nuclear Information System (INIS)

    Full text: Comparative evaluation of 11C Methionine (MET-PET) and 18F flurodeoxyglucose (FDG) PET/CT for detection of recurrent brain tumors. Patients and Methods: 23 post-operative, histologically proven cases of primary brain tumors were included; there were two cases of grade I (WHO), 9 cases of grade II, 5 cases of grade III, 3 cases of grade IV, 3 medulloblastomas and one gliosarcoma. Ratio of M:F=16:7, age 27.5+14.4 years (range 5-56 years). All patients underwent the MET-PET and FDG-PET scans on the same day. Images were evaluated for recurrence using visual analysis and final results were compared with MRI/MRS and follow up as gold standard. Results: Fourteen cases were positive for recurrence on the MET-PET study while FDG was unequivocally positive in eleven cases. MET-PET scans were true negative for recurrence in nine cases and concurrent with the MRI/MRS findings in all 23 cases. Tumor to background ratio for the MET-PET study were 2.2+.55. Conclusion: MET-PET is superior to FDG-PET for detection of recurrence in both low and high grade gliomas and has excellent correlation with MRI/MRS

  3. Tracers development for the PET study of nicotinic receptors: [11C]-mecamylamine and [11C]-SIB 1553A. Tritium and carbon-11 radiolabelling of a serine proteinase inhibitor: the t-PAstop

    International Nuclear Information System (INIS)

    In order to develop radiotracers for the Positron Emission Tomography (PET), we labelled both the mecamylamine and SIB-1553A with carbon-11 to study the nicotinic cholinergic receptors (nAChRs). The radiosynthesis of [11C]-t-PAstop and the labelling with tritium of one analogue were realized for cerebral ischemia PET studies. The [11C]-mecamylamine, a non-competitive and non-selective nAChRs antagonist was synthesized in 45 min via a N-[11C]-methylation reaction. In the rat brain, the ex vivo studies showed no radio-metabolite 45 min after the injection of [11C]-mecamylamine. The uptake kinetics in the rat brain or in vivo by PET in the anesthetized baboon or in the conscious monkey, reached a plateau around 45-50 min after injection. However, the saturation or displacement experiments did not permit to exhibit nor a significant difference of labelling between the different cerebral regions nor a specific uptake. In consequence, the [11C]-mecamylamine was not an appropriate radioligand for nAChRs PET study. The labelling of [11C]-SIB 1553A, a selective agonist for the nicotinic β4 subunit, required the synthesis in 5 steps (56% overall yield) of precursor for the incorporation of carbon-11. The radiosynthesis was performed in 36 min by a N-[11C]-methylation reaction (yield: 75%). The [11C]-t-PAstop was obtained from [11C]-KCN with yields from 80 to 90%. For the first time with carbon-11, the formation of an amidine group was realized from a nitrile group. The labelling by isotopic exchange of hydrogen by tritium of the t-PAstop did not permit to obtain the [3H]-t-PAstop but a tritiated analogue. This compound will be used to study its vectorization by micro-encapsulation. (author)

  4. Uptake of 11C-methionine in breast cancer studied by PET. An association with the size of S-phase fraction.

    OpenAIRE

    Leskinen-Kallio, S.; Någren, K.; Lehikoinen, P.; Ruotsalainen, U; Joensuu, H.

    1991-01-01

    L-[methyl-11-C]methionine (11C-methionine) uptake of seven primary breast cancers, four soft tissue metastases of breast cancer, and three other breast lesions was studied by positron emission tomography (PET). 11C-methionine accumulation was assessed by calculating the standardised uptake value (SUV). The mean SUV for breast cancer was 8.5 +/- 3.3 (s.d.), while the maximal uptake in the liver was 12.4 +/- 1.6, in the bone marrow 5.8 +/- 0.7, and in the myocardium 3.4 +/- 0.6. All eight malig...

  5. A False-Negative Case of Primary Central Nervous System Lymphoma on 11C-Methionine PET and Intense 18F-FDG Uptake.

    Science.gov (United States)

    García-Garzon, J R; Villasboas-Rosciolesi, Diego; Baquero, Miguel; Bassa, Pere; Soler, Marina; Riera, Eduard

    2016-08-01

    We report a case of a 44-year-old man with neurological symptoms and MRI findings, which were unable to differentiate between glioma and lymphoma. Metabolic characterization by means of PET imaging with F-FDG and C-methionine is proposed to determine the benign or tumor (high- and low-grade) origin of brain lesions. In this case, the MRI lesion corresponded with an inconclusive metabolic pattern of intense F-FDG uptake and no significant C-methionine uptake. Pathological study revealed a false-negative case of C-methionine due to lymphoma. PMID:27187734

  6. Clinical value of {sup 11}C-methionine PET/CT in patients with plasma cell malignancy: comparison with {sup 18}F-FDG PET/CT

    Energy Technology Data Exchange (ETDEWEB)

    Nakamoto, Yuji; Kurihara, Kensuke; Nakatani, Koya; Togashi, Kaori [Kyoto University Graduate School of Medicine, Department of Diagnostic Imaging and Nuclear Medicine, Kyoto (Japan); Nishizawa, Masatoshi; Yamashita, Kouhei; Kondo, Tadakazu; Takaori-Kondo, Akifumi [Kyoto University Graduate School of Medicine, Department of Hematology and Oncology, Kyoto (Japan)

    2013-05-15

    PET/CT using FDG has been widely used for the imaging of various malignant tumours, including plasma cell malignancy (PCM), but {sup 11}C-methionine (MET), as a radiolabelled amino acid tracer, may also be useful because PCM is able to activate protein synthesis. The purpose of this study was to evaluate the clinical value of PET/CT imaging using MET in PCM, including multiple myeloma, compared with that of FDG PET/CT. The study group comprised 20 patients with histologically proven PCM who underwent FDG PET/CT and MET PET/CT scans before (n = 6) or after (n = 14) treatment. Semiquantitative analysis was performed on a lesion basis. We also visually evaluated the scans qualitatively using a five-point scale (0, negative; 1, probably negative; 2, equivocal; 3, probably positive; 4, positive) on a lesion and a patient basis. The results were compared between the two scans. Active PCM was confirmed in 15 patients, including two patients with extramedullary lesions. Uptake of MET tended to be higher (maximum standardized uptake value 10.3 {+-} 5.6, mean {+-} SD) than that of FDG (3.4 {+-} 2.7, p < 0.001), and more lesions of grade 3 or 4 were depicted by MET (MET 156 lesions vs. FDG 58 lesions). On a patient basis, two patients were accurately diagnosed only by MET. In the remaining 18 patients, consistent results were obtained, but potential upgrade of staging or restaging was necessary in 6 of 11 positive patients because more abnormal lesions were demonstrated by MET. The patient-based sensitivity, specificity and accuracy of MET for restaging were 89 %, 100 % and 93 %, respectively, while those of FDG were 78 %, 100 % and 86 %, respectively. MET revealed an equal or greater number of lesions in PCM than FDG. MET may be especially useful when negative or inconclusive findings are obtained by FDG despite highly suspicious indications of recurrence. (orig.)

  7. Dynamic {sup 11}C-methionine PET analysis has an additional value for differentiating malignant tumors from granulomas: an experimental study using small animal PET

    Energy Technology Data Exchange (ETDEWEB)

    Zhao, Songji; Zhao, Yan [Hokkaido University, Department of Nuclear Medicine, Graduate School of Medicine, Sapporo (Japan); Hokkaido University, Department of Tracer Kinetics and Bioanalysis, Graduate School of Medicine, Sapporo (Japan); Kuge, Yuji; Hatano, Toshiyuki [Hokkaido University, Central Institute of Isotope Science, Sapporo (Japan); Yi, Min; Kohanawa, Masashi [Hokkaido University, Department of Advanced Medicine, Graduate School of Medicine, Sapporo (Japan); Magota, Keiichi; Tamaki, Nagara [Hokkaido University, Department of Nuclear Medicine, Graduate School of Medicine, Sapporo (Japan); Nishijima, Ken-ichi [Hokkaido University, Department of Molecular Imaging, Graduate School of Medicine, Sapporo (Japan)

    2011-10-15

    We evaluated whether the dynamic profile of L-{sup 11}C-methionine ({sup 11}C-MET) may have an additional value in differentiating malignant tumors from granulomas in experimental rat models by small animal positron emission tomography (PET). Rhodococcus aurantiacus and allogenic rat C6 glioma cells were inoculated, respectively, into the right and left calf muscles to generate a rat model bearing both granulomas and tumors (n = 6). Ten days after the inoculations, dynamic {sup 11}C-MET PET was performed by small animal PET up to 120 min after injection of {sup 11}C-MET. The next day, after overnight fasting, the rats were injected with {sup 18}F-2-deoxy-2-fluoro-D-glucose ({sup 18}F-FDG), and dynamic {sup 18}F-FDG PET was performed up to 180 min. The time-activity curves, static images, and mean standardized uptake value (SUV) in the lesions were calculated. {sup 11}C-MET uptake in the granuloma showed a slow exponential clearance after an initial distribution, while the uptake in the tumor gradually increased with time. The dynamic pattern of {sup 11}C-MET uptake in the granuloma was significantly different from that in the tumor (p < 0.001). In the static analysis of {sup 11}C-MET, visual assessment and SUV analysis could not differentiate the tumor from the granuloma in all cases, although the mean SUV in the granuloma (1.48 {+-} 0.09) was significantly lower than that in the tumor (1.72 {+-} 0.18, p < 0.01). The dynamic patterns, static images, and mean SUVs of {sup 18}F-FDG in the granuloma were similar to those in the tumor (p = NS). Dynamic {sup 11}C-MET PET has an additional value for differentiating malignant tumors from granulomatous lesions, which deserves further elucidation in clinical settings. (orig.)

  8. Clinical value of 11C-methionine PET/CT in patients with plasma cell malignancy: comparison with 18F-FDG PET/CT

    International Nuclear Information System (INIS)

    PET/CT using FDG has been widely used for the imaging of various malignant tumours, including plasma cell malignancy (PCM), but 11C-methionine (MET), as a radiolabelled amino acid tracer, may also be useful because PCM is able to activate protein synthesis. The purpose of this study was to evaluate the clinical value of PET/CT imaging using MET in PCM, including multiple myeloma, compared with that of FDG PET/CT. The study group comprised 20 patients with histologically proven PCM who underwent FDG PET/CT and MET PET/CT scans before (n = 6) or after (n = 14) treatment. Semiquantitative analysis was performed on a lesion basis. We also visually evaluated the scans qualitatively using a five-point scale (0, negative; 1, probably negative; 2, equivocal; 3, probably positive; 4, positive) on a lesion and a patient basis. The results were compared between the two scans. Active PCM was confirmed in 15 patients, including two patients with extramedullary lesions. Uptake of MET tended to be higher (maximum standardized uptake value 10.3 ± 5.6, mean ± SD) than that of FDG (3.4 ± 2.7, p < 0.001), and more lesions of grade 3 or 4 were depicted by MET (MET 156 lesions vs. FDG 58 lesions). On a patient basis, two patients were accurately diagnosed only by MET. In the remaining 18 patients, consistent results were obtained, but potential upgrade of staging or restaging was necessary in 6 of 11 positive patients because more abnormal lesions were demonstrated by MET. The patient-based sensitivity, specificity and accuracy of MET for restaging were 89 %, 100 % and 93 %, respectively, while those of FDG were 78 %, 100 % and 86 %, respectively. MET revealed an equal or greater number of lesions in PCM than FDG. MET may be especially useful when negative or inconclusive findings are obtained by FDG despite highly suspicious indications of recurrence. (orig.)

  9. Use of {sup 11}C-methionine PET to monitor the effects of temozolomide chemotherapy in malignant gliomas

    Energy Technology Data Exchange (ETDEWEB)

    Galldiks, Norbert; Kracht, Lutz W.; Burghaus, Lothar; Thomas, Anne; Jacobs, Andreas H.; Heiss, Wolf-Dieter; Herholz, Karl [University of Manchester, Wolfson Molecular Imaging Centre, Manchester (United Kingdom)

    2006-05-15

    The purpose of this study was to monitor the metabolic effects of temozolomide (TMZ) chemotherapy in malignant gliomas by means of repeated positron emission tomography (PET) with [{sup 11}C]methionine (MET). Fifteen patients with histologically proven malignant glioma were treated by TMZ chemotherapy. MET-PET studies were performed before and after the third cycle of TMZ chemotherapy in all patients, and in 12 patients also after the sixth cycle. Gadolinium-enhanced MRI studies were performed in 12 patients before the first and after the sixth cycle. Clinical status was assessed by the modified Rankin scale. Long-term outcome was assessed by calculating the time to progression (TTP) in months. Decline in MET uptake during therapy corresponded to a stable clinical status. The median TTP was significantly longer in patients with decline in MET uptake than in those with increasing MET uptake (23 vs 3.5 months; p=0.01, log rank test). There was no significant correlation between change in MET uptake and change in contrast enhancement during treatment for all patients. The present data demonstrate that clinical stability, which is often achieved under TMZ chemotherapy of malignant glioma, corresponds to a decline in or stability of tumour amino acid metabolism. Tumour responses can already be demonstrated with MET-PET after three cycles of chemotherapy, and absence of progression at that time indicates a high probability of further stability during the next three cycles. A reduction in MET uptake during TMZ treatment predicts a favourable clinical outcome. Molecular imaging of amino acid uptake by MET-PET offers a new method of measurement of the biological activity of recurrent glioma. (orig.)

  10. Correlation of biological aggressiveness assessed by 11C-methionine PET and hypoxic burden assessed by 18F-fluoromisonidazole PET in newly diagnosed glioblastoma

    International Nuclear Information System (INIS)

    Glioblastoma multiforme (GBM) is characterized by tissue hypoxia associated with resistance to radiotherapy and chemotherapy. To clarify the biological link between hypoxia and tumour-induced neovascularization and tumour aggressiveness, we analysed detailed volumetric and spatial information of viable hypoxic tissue assessed by 18F-fluoromisonidazole (FMISO) PET relative to neovascularization in Gd-enhanced MRI and tumour aggressiveness by L-methyl-11C-methionine (MET) PET in newly diagnosed GBMs. Ten patients with newly diagnosed GBMs were investigated with FMISO PET, MET PET and Gd-enhanced MRI before surgery. Tumour volumes were calculated by performing a three-dimensional threshold-based volume of interest (VOI) analysis for metabolically active volume on MET PET (MET uptake indices of ≥1.3 and ≥1.5) and Gd-enhanced volume on MRI. FMISO PET was scaled to the blood FMISO activity to create tumour to blood (T/B) images. The hypoxic volume (HV) was defined as the region with T/B greater than 1.2. PET and MR images of each patient were coregistered to analyse the spatial location of viable hypoxic tissue relative to neovascularization and active tumour extension. Metabolically active tumour volumes defined using MET uptake indices of ≥1.3 and ≥1.5 and the volumes of Gd enhancement showed a strong correlation (r = 0.86, p < 0.01 for an index of ≥1.3 and r = 0.77, p < 0.05 for an index of ≥1.5). The HVs were also excellently correlated with the volumes of Gd enhancement (r = 0.94, p < 0.01). The metabolically active tumour volumes as defined by a MET uptake index of ≥1.3 and the HVs exhibited a strong correlation (r = 0.87, p < 0.01). On superimposed images, the metabolically active area on MET PET defined by a MET uptake index of ≥1.3 was usually larger than the area of the Gd enhancement and about 20-30% of the MET area extended outside the area of the enhancement. On the other hand, the surface area of viable hypoxic tissue with a T/B cutoff of

  11. Combined 18F-FDG and 11C-Methionine PET/CT scans in a case of metastatic hepatocellular carcinoma

    International Nuclear Information System (INIS)

    A 37-year-old male who underwent a central hepatectomy of the liver for hepatocellular carcinoma (HCC) was referred for an 18F-fluorodeoxyglucose positron emission tomography/computed tomography (18F-FDG PET/CT) study to rule out tumor recurrence or metastases. The scan showed a recurrent hepatic mass at the operative site, along with low-grade uptake in bilateral pulmonary metastases, mediastinal and hilar lymph nodes, and few skeletal sites. A non-FDG avid intracranial extradural mass was visualized in the right frontal lobe. The 11C-methionine PET/CT scan performed subsequently revealed a larger area of involvement at the primary site, along with widespread metastases to the lungs, mediastinal, hilar, and abdominal lymph nodes, and multiple skeletal sites. Further, dural metastasis with high tracer uptake was noted in the frontal region. To the best of our knowledge, this is the first case documented in the literature, wherein 11C-methionine PET/CT played a significant role in delineating the widespread dissemination, including the extremely rare dural involvement in a case of HCC. This report highlights the potential value of 11C-methionine PET/CT in assessing the hepatic and extrahepatic tumor burden in cases of HCC, especially in clinically unexpected locations

  12. Investigations of acetonitrile solvent cluster formation in supercritical carbon dioxide, and its impact on microscale syntheses of carbon-11-labeled radiotracers for PET

    International Nuclear Information System (INIS)

    A new strategy has been developed for synthesizing positron emission tomography (PET) radiotracers using [11C]methyl iodide. This strategy relies on the ability of organic co-solvents to cluster within mixtures of supercritical fluids resulting in localized regions of high density which can serve as microscopic pockets for reaction. We've shown that acetonitrile will cluster about dilute solutes when mixtures of this co-solvent with carbon dioxide are forced to behave as a homogeneous fluid at the critical point. We applied this strategy in a systematic investigation of the conditions for optimized reaction between methyl iodide and L-α-methyl-N-2-propynyl phenethylamine (nordeprenyl) to yield L-deprenyl. Variables such as temperature, ultraviolet light exposure, co-solvent concentration, system pressure, and methyl iodide concentration were explored. The synthesis of radioactive [11C]-L-deprenyl using no-carrier-added concentrations of [11C]methyl iodide was also tested. Results showed that greater than 90% radiochemical yield of the desired product could be attained using 40 times less labeling substrate than in conventional PET tracer syntheses

  13. Prognostic value of volume-based measurements on {sup 11}C-methionine PET in glioma patients

    Energy Technology Data Exchange (ETDEWEB)

    Kobayashi, Kentaro; Manabe, Osamu; Shiga, Tohru; Tamaki, Nagara [Hokkaido University, Department of Nuclear Medicine, Graduate School of Medicine, Sapporo, Hokkaido (Japan); Hirata, Kenji [Hokkaido University, Department of Nuclear Medicine, Graduate School of Medicine, Sapporo, Hokkaido (Japan); David Geffen School of Medicine at UCLA, Department of Molecular and Medical Pharmacology, Los Angeles, CA (United States); Yamaguchi, Shigeru; Terasaka, Shunsuke; Kobayashi, Hiroyuki [Hokkaido University, Department of Neurosurgery, Graduate School of Medicine, Sapporo (Japan); Hattori, Naoya [Hokkaido University, Department of Molecular Imaging, Graduate School of Medicine, Sapporo (Japan); Tanaka, Shinya [Hokkaido University, Department of Cancer Pathology, Graduate School of Medicine, Sapporo (Japan); Kuge, Yuji [Hokkaido University, Central Institute of Isotope Science, Sapporo (Japan)

    2015-04-08

    {sup 11}C-methionine (MET) PET is an established diagnostic tool for glioma. Studies have suggested that MET uptake intensity in the tumor is a useful index for predicting patient outcome. Because MET uptake is known to reflect tumor expansion more accurately than MRI, we aimed to elucidate the association between volume-based tumor measurements and patient prognosis. The study population comprised 52 patients with newly diagnosed glioma who underwent PET scanning 20 min after injection of 370 MBq MET. The tumor was contoured using a threshold of 1.3 times the activity of the contralateral normal cortex. Metabolic tumor volume (MTV) was defined as the total volume within the boundary. Total lesion methionine uptake (TLMU) was defined as MTV times the mean standardized uptake value (SUVmean) within the boundary. The tumor-to-normal ratio (TNR), calculated as the maximum standardized uptake value (SUVmax) divided by the contralateral reference value, was also recorded. All patients underwent surgery (biopsy or tumor resection) targeting the tissue with high MET uptake. The Kaplan-Meier method was used to estimate the predictive value of each measurement. Grade II tumor was diagnosed in 12 patients (3 diffuse astrocytoma, 2 oligodendroglioma, and 7 oligoastrocytoma), grade III in 18 patients (8 anaplastic astrocytoma, 6 anaplastic oligodendroglioma, and 4 anaplastic oligoastrocytoma), and grade IV in 22 patients (all glioblastoma). TNR, MTV and TLMU were 3.1 ± 1.2, 51.6 ± 49.9 ml and 147.7 ± 153.3 ml, respectively. None of the three measurements was able to categorize the glioma patients in terms of survival when all patients were analyzed. However, when only patients with astrocytic tumor (N = 33) were analyzed (i.e., when those with oligodendroglial components were excluded), MTV and TLMU successfully predicted patient outcome with higher values associated with a poorer prognosis (P < 0.05 and P < 0.01, respectively), while the predictive ability of TNR did not

  14. Volumetry of [{sup 11}C]-methionine PET uptake and MRI contrast enhancement in patients with recurrent glioblastoma multiforme

    Energy Technology Data Exchange (ETDEWEB)

    Galldiks, Norbert; Schroeter, Michael; Fink, Gereon R. [University Hospital of Cologne, Department of Neurology, Cologne (Germany); Ullrich, Roland; Kracht, Lutz W. [Max Planck-Institute for Neurological Research, Cologne (Germany)

    2010-01-15

    We investigated the relationship between three-dimensional volumetric data of the metabolically active tumour volume assessed using [{sup 11}C]-methionine positron emission tomography (MET-PET) and the area of gadolinium-diethylenetriaminepentaacetic acid (Gd-DTPA) enhancement assessed using magnetic resonance imaging (MRI) in patients with recurrent glioblastoma (GBM). MET-PET and contrast-enhanced MRI with Gd-DTPA were performed in 12 uniformly pretreated patients with recurrent GBM. To calculate the volumes in cubic centimetres, a threshold-based volume-of-interest (VOI) analysis of the metabolically active tumour volume (MET uptake indexes of {>=}1.3 and {>=}1.5) and of the area of Gd-DTPA enhancement was performed after coregistration of all images. In all patients, the metabolically active tumour volume as shown using a MET uptake index of {>=}1.3 was larger than the volume of Gd-DTPA enhancement (30.2 {+-} 22.4 vs. 13.7 {+-} 10.6 cm{sup 3}; p = 0.04). Metabolically active tumour volumes as shown using MET uptake indexes of {>=}1.3 and {>=}1.5 and the volumes of Gd-DTPA enhancement showed a positive correlation (r = 0.76, p = 0.003, for an index of {>=}1.3, and r = 0.74, p = 0.005, for an index of {>=}1.5). The present data suggest that in patients with recurrent GBM the metabolically active tumour volume may be substantially underestimated by Gd-DTPA enhancement. The findings support the notion that complementary information derived from MET uptake and Gd-DTPA enhancement may be helpful in developing individualized, patient-tailored therapy strategies in patients with recurrent GBM. (orig.)

  15. Carbon-11 labelling of eticlopride in two different positions - a selective high-affinity ligand for the study of dopamine D-2 receptors using PET

    International Nuclear Information System (INIS)

    A new highly selective high-affinity dopamine D-2 receptor antagonist, eticlopride ((-)-(S)-5-chloro-3-ethyl-N-(1-ethyl-2-pyrrolidinyl)methyl)-6-methoxysalicylamide), was labelled with 11C in two different positions ([N-ethyl-11C]eticlopride (I) and ([methyl-11C]eticlopride (II)). Product I was prepared by N-alkylation of the N-desethyl compound with [11C]ethyl iodide. II was prepared by O-alkylation of the diphenolic precursor with [11C]methyl iodide followed by separation of the two methylated products. The radiochemical yields were 15-20% (EOB) with an overall synthesis time of 45-60 min. Both compounds were isolated by semi-preparative HPLC and the radiochemical purity was in both cases > 99%. I was injected i.v. in a Cynomolgus monkey and brain radioactivity was measured by positron emission tomography (PET). The specific activity was 70 Ci/mmol at time of injection. There was a marked accumulation of radioactivity in the basal ganglia, regions known to have a high density of dopamine D-2 receptors. (author)

  16. A refined method for quantification of myocardial oxygen consumption rate using mean transit time with carbon-11-acetate and dynamic PET.

    Science.gov (United States)

    Choi, Y; Huang, S C; Hawkins, R A; Hoh, C K; Krivokapich, J; Buxton, D B; Armbrecht, J J; Sun, K T; Phelps, M E; Schelbert, H R

    1993-11-01

    The utility of the mean transit time equation was investigated for estimation of the myocardial clearance rate constant of 11C-acetate, which is proportional to myocardial oxygen consumption rates. The mean transit time approach was also employed to generate parametric images of the clearance rate constant of 11C-acetate with dynamic PET imaging in 20 normal human studies. Input function delays and cutoff errors due to the truncation of the myocardial tissue time-activity curve at a finite time were corrected. The clearance rate constants estimated by mean transit time correlated well with the estimates by conventional monoexponential fitting (15 min (truncation time): Y = 0.01 + 0.94X, correlated coefficient (r) = 0.99; 16 min: Y = 0.03 + 0.94X, r = 0.98; 20 min: Y = 0.03 + 0.84X, r = 0.99). The clearance rate constants estimated by the mean transit time approach also correlated well (r = 0.94) with the measured rate-pressure products. The quality and noise level of parametric images of the clearance rate constants generated by mean transit time are improved over those generated by monoexponential fitting. Additional advantages of the mean transit time approach compared to the standard monoexponential fitting method for estimating myocardial clearance rate constant of 11C-acetate include ease of input function delay correction, less sensitivity to the shape of the input function and elimination of subjective data selection of the linear portion of the clearance data on a semilog plot. Thus, this approach is expected to facilitate objective quantitative analysis of indices of myocardial oxygen consumption. PMID:8229256

  17. Prognostic value of metabolic tumor volume on {sup 11}C-methionine PET in predicting progression-free survival in high-grade glioma

    Energy Technology Data Exchange (ETDEWEB)

    Yoo, Min Young; Paeng, Jin Chul; Cheon, Gi Jeong; Lee, Dong Soo; Chung, June Key; Kang, Keon Wook [Dept. of Nuclear Medicine, Seoul National University Hospital, Seoul (Korea, Republic of); Kim, E. Edmund [Dept. of Molecular Medicine and Biopharmaceutical Sciences, Graduate School of Convergence Science and Technology, Seoul National University, Seoul (Korea, Republic of)

    2015-12-15

    C-11 methionine (MET) PET is commonly used for diagnosing high-grade glioma (HGG). Recently, volumetric analysis has been widely applied to oncologic PET imaging. In this study, we investigated the prognostic value of metabolic tumor volume (MTV) on MET PET in HGG. A total of 30 patients with anaplastic astrocytoma (n = 12) and glioblastoma multiforme (n = 18) who underwent MET PET before treatment (surgery followed by chemo-radiotherapy) were retrospectively enrolled. Maximal tumor-to-normal brain ratio (TNR{sub max}, maximum tumor activity divided by mean of normal tissue) and MTV (volume of tumor tissue that shows uptake >1.3-fold of mean uptake in normal tissue) were measured on MET PET. Adult patients were classified into two subgroups according to Radiation Therapy Oncology Group Recursive Partitioning Analysis (RTOG RPA) classification. Prognostic values of TNR{sub max}, MTV and clinicopathologic factors were evaluated with regard to progression-free survival (PFS). Median PFS of all patients was 7.9 months (range 1.0–53.8 months). In univariate analysis, MTV (cutoff 35 cm{sup 3}) was a significant prognostic factor for PFS (P = 0.01), whereas TNR{sub max} (cutoff 3.3) and RTOG RPA class were not (P = 0.80 and 0.61, respectively). Treatment of surgical resection exhibited a borderline significance (P = 0.06). In multivariate analysis, MTV was the only independent prognostic factor for PFS (P = 0.03). MTV on MET PET is a significant and independent prognostic factor for PFS in HGG patients, whereas TNR{sub max} is not. Thus, performing volumetric analysis of MET PET is recommended in HGG for better prognostication.

  18. Tracer accumulation in radiation necrosis of the brain after thallium-201 SPECT and [{sup 11}C]methionine PET. Case report

    Energy Technology Data Exchange (ETDEWEB)

    Iwai, Yoshiyasu; Yamanaka, Kazuhiro; Oda, Junro [Osaka City General Hospital (Japan); Tsuyuguchi, Naohiro; Ochi, Hironobu

    2001-08-01

    A 69-year-old woman was treated by local irradiation for a malignant lymphoma of the left parotid gland. Three years after the radiation therapy, magnetic resonance imaging revealed heterogeneously enhanced masses in the left temporal lobe and left cerebellum. Thallium-201 chloride single photon emission computed tomography (Tl-SPECT) revealed high uptake and [{sup 11}C]methionine positron emission tomography (Met-PET) revealed moderate uptake in both masses. Stereotactic biopsy was performed. The histological diagnosis was radiation necrosis. She was treated with steroids. Neurosurgeons should be aware of the difficulty in differentiating tumor recurrence from radiation necrosis even with Tl-SPECT and Met-PET, and the importance of obtaining a histological diagnosis for radiation necrosis. (author)

  19. Direct comparison of {sup 18}F-FDG and {sup 11}C-methionine PET in suspected recurrence of glioma: sensitivity, inter-observer variability and prognostic value

    Energy Technology Data Exchange (ETDEWEB)

    Laere, Koen Van; Ceyssens, Sarah; Mortelmans, Luc [University Hospital Leuven, Division of Nuclear Medicine, Leuven (Belgium); Calenbergh, Frank Van [University Hospital Leuven, Department of Neurosurgery, Leuven (Belgium); Groot, Tjibbe de; Bormans, Guy [University Hospital Leuven, Laboratory of Radiopharmaceutical Chemistry, Leuven (Belgium); Menten, Johan [University Hospital Leuven, Division of Radiotherapy, Leuven (Belgium); Flamen, Patrick [University Hospital Leuven, Division of Nuclear Medicine, Leuven (Belgium); Bordet Hospital, Division of Nuclear Medicine, Brussels (Belgium)

    2005-01-01

    {sup 18}F-fluorodeoxyglucose (FDG) and {sup 11}C-methionine (MET) PET imaging studies allow the investigation of metabolism and amino acid transport in brain tumours. Their (relative) usefulness and prognostic value in suspected recurrence or progression of primary brain tumours after previous therapy is an issue of debate. The aim of this study was to compare directly both radioligands in this setting. Cerebral uptake of FDG and MET was determined sequentially on the same day in 30 patients (21 males, nine females; age 40.4{+-}15.6 years), on average 4.0 years (range 0.1-18) after therapy for a primary brain tumour (23 grade II-IV astrocytomas, four oligodendrogliomas and three mixed oligo-astrocytomas). Images were acquired on a Siemens HR+ dedicated PET camera. Two observers scored FDG and MET scans independently. Semi-quantitative indices defined by the tumour (maximum)-to-background ratio were calculated based on manual ROI delineation and by using MET ROIs for FDG after automated co-registration. Patient follow-up was conducted until the last contact with inconspicuous clinical findings (average 41 months, range 12-62 months after PET) [(n=10)] or until death (n=20). Overall median survival was 15.0 months. MET showed pathologically increased uptake in 28/30 scans, and FDG in 17/30. The inter-observer agreement was 100% for MET and 73% for FDG. Using Kaplan-Meier survival analysis, significant differences were found for both FDG (cut-off 0.8, log-rank p=0.007) and MET (cut-off 2.2, log-rank p=0.014). The combination of FDG and MET information resulted in the highest prognostic accuracy (p=0.003), while MET alone was the best prognostic predictor in the subgroup of patients with primary astrocytoma (n=23). FDG and MET PET studies provide complementary prognostic information in patients with suspected brain tumour recurrence or progression after primary therapy. MET is considered the single agent of choice in the evaluation of these patients because of its

  20. Ethanolic Carbon-11 Chemistry: the Introduction of Green Radiochemistry

    Science.gov (United States)

    Shao, Xia; Fawaz, Maria V.; Jang, Keunsam; Scott, Peter J. H.

    2014-01-01

    The principles of green chemistry have been applied to a radiochemistry setting. Eleven carbon-11 labeled radiopharmaceuticals have been prepared using ethanol as the only organic solvent throughout the entire manufacturing process. The removal of all other organic solvents from the process simplifies production and quality control (QC) testing, moving our PET Center towards the first example of a green radiochemistry laboratory. All radiopharmaceutical doses prepared are suitable for clinical use. PMID:24631743

  1. Ethanolic carbon-11 chemistry: the introduction of green radiochemistry.

    Science.gov (United States)

    Shao, Xia; Fawaz, Maria V; Jang, Keunsam; Scott, Peter J H

    2014-07-01

    The principles of green chemistry have been applied to a radiochemistry setting. Eleven carbon-11 labeled radiopharmaceuticals have been prepared using ethanol as the only organic solvent throughout the entire manufacturing process. The removal of all other organic solvents from the process simplifies production and quality control (QC) testing, moving our PET Center towards the first example of a green radiochemistry laboratory. All radiopharmaceutical doses prepared are suitable for clinical use.

  2. Differentiation of Brain Tumor Recurrence from Post-Radiotherapy Necrosis with 11C-Methionine PET: Visual Assessment versus Quantitative Assessment.

    Directory of Open Access Journals (Sweden)

    Ryogo Minamimoto

    Full Text Available The aim of this multi-center study was to assess the diagnostic capability of visual assessment in L-methyl-11C-methionine positron emission tomography (MET-PET for differentiating a recurrent brain tumor from radiation-induced necrosis after radiotherapy, and to compare it to the accuracy of quantitative analysis.A total of 73 brain lesions (glioma: 31, brain metastasis: 42 in 70 patients who underwent MET-PET were included in this study. Visual analysis was performed by comparison of MET uptake in the brain lesion with MET uptake in one of four regions (around the lesion, contralateral frontal lobe, contralateral area, and contralateral cerebellar cortex. The concordance rate and logistic regression analysis were used to evaluate the diagnostic ability of visual assessment. Receiver-operating characteristic curve analysis was used to compare visual assessment with quantitative assessment based on the lesion-to-normal (L/N ratio of MET uptake.Interobserver and intraobserver κ-values were highest at 0.657 and 0.714, respectively, when assessing MET uptake in the lesion compared to that in the contralateral cerebellar cortex. Logistic regression analysis showed that assessing MET uptake in the contralateral cerebellar cortex with brain metastasis was significantly related to the final result. The highest area under the receiver-operating characteristic curve (AUC with visual assessment for brain metastasis was 0.85, showing no statistically significant difference with L/Nmax of the contralateral brain (AUC = 0.89 or with L/Nmean of the contralateral cerebellar cortex (AUC = 0.89, which were the areas that were the highest in the quantitative assessment. For evaluation of gliomas, no specific candidate was confirmed among the four areas used in visual assessment, and no significant difference was seen between visual assessment and quantitative assessment.The visual assessment showed no significant difference from quantitative assessment of MET-PET

  3. PET

    DEFF Research Database (Denmark)

    Mariager, Rasmus Mølgaard; Schmidt, Regin; Heiberg, Morten Rievers

    PET handler om den hemmelige tjenestes arbejde under den kolde krig 1945-1989. Her fortæller Regin Schmidt, Rasmus Mariager og Morten Heiberg om de mest dramatiske og interessante sager fra PET's arkiv. PET er på flere måder en udemokratisk institution, der er sat til at vogte over demokratiet....... Dens virksomhed er skjult for offentligheden, den overvåger borgernes aktiviteter, og den registrerer følsomme personoplysninger. Historien om PET rejser spørgsmålet om, hvad man skal gøre, når befolkningen i et demokrati er kritisk indstillet over for overvågningen af lovlige politiske aktiviteter......, mens myndighederne mener, at det er nødvendigt for at beskytte demokratiet. PET er på en gang en fortælling om konkrete aktioner og begivenheder i PET's arbejde og et stykke Danmarkshistorie. Det handler om overvågning, spioner, politisk ekstremisme og international terrorisme.  ...

  4. A quartz-lined carbon-11 target: striving for increased yield and specific activity

    DEFF Research Database (Denmark)

    Koziorowski, Jacek; Larsen, Peter; Gillings, Nic

    2010-01-01

    The increased demand for high specific radioactivity neuroreceptor ligands for positron emission tomography (PET) requires the production of high specific radioactivity carbon-11 in high yields. We have attempted to address this issue with the development of a new quartz-lined aluminium target fo...

  5. Detection and Characterization of Parathyroid Adenoma/Hyperplasia for Preoperative Localization: Comparison Between {sup 11}C-Methionine PET/CT and {sup 99m}Tc-Sestamibi Scintigraphy

    Energy Technology Data Exchange (ETDEWEB)

    Chun, In Kook; Cheon, Gi Jeong; Paeng, Jin Chul; Kang, Keon Wook; Chung, Junekey; Lee, Dong Soo [Seoul National Univ. College of Medicine, Seoul (Korea, Republic of)

    2013-09-15

    {sup 11}C-Methionine PET/CT (Met-PET/CT) is a useful imaging method for detection of parathyroid adenoma; however, the reported detection rate has been variable. The current study was intended to investigate detection sensitivity and preoperative localization of parathyroid adenoma (PA) or parathyroid hyperplasia (PH) on Met-PET/CT compared with {sup 99m}Tc-sestamibi (MIBI) scintigraphy in patients with primary hyperparathyroidism (HPT) or suspected PA. Met-PET/CT and MIBI scintigraphy images were reviewed by two nuclear medicine physicians unaware of pathologic results. Detection sensitivities and preoperative localization of detected parathyroid tissues into five predefined segments were evaluated by visual assessment and semiquantitative analysis with ratio of standardized uptake values (SUVR) between parathyroid tissue and normal lung as reference. Linear regression analysis with SUVR and serum parathyroid hormone (sPTH) was performed for characterization of PA or PH. Predicted PTH (pPTH) was calculated and compared with sPTH in PH and PA. Each pPTH was obtained for a calculated SUVR by using linear regression model from the result of previous linear regression analysis between SUVR and sPTH. In 16 patients, detection sensitivities of Met-PET/CT and MIBI scintigraphy were 91.7 % (11/12) and 41.7 % (5/12) for PA and PH including both biopsy-confirmed and clinically-suspected cases, and 100 % (8/8) and 50 % (4/8) for pathologically confirmed PA and PH cases only, respectively. Met-PET/CT showed higher performance than MIBI scintigraphy in localization of parathyroid tissues; correct localization rate was 87.5 % (7/8) on Met-PET/CT and 50 % (4/8) on MIBI scintigraphy. In semi-quantitative analysis, SUVR was linearly associated with sPTH by linear regression analysis (sPTH=39.53ΧSUVR-89.84, p=0.0383). There was a borderline significant difference in pPTH between PH and PA (35.1 vs 204.7±164.0, p=0.052),while there was no significant difference in sPTH between PH

  6. PET STUDIES WITH L-[1-C-11]TYROSINE, L-[METHYL-C-11]METHIONINE AND F-18 FLUORODEOXYGLUCOSE IN PROLACTINOMAS IN RELATION TO BROMOCRYPTINE TREATMENT

    NARCIS (Netherlands)

    DAEMEN, BJG; ZWERTBROEK, R; ELSINGA, PH; PAANS, AMJ; DOORENBOS, H; VAALBURG, W

    1991-01-01

    Aspects of metabolism in prolactinomas were investigated by positron emission tomography using L-[1-C-11]tyrosine, L-[methyl-C-11]methionine and F-18-fluorodeoxyglucose (18FDG). Using L-[1-C-11]tyrosine, four patients were monitored prior to and 18 h after an injection of 50 mg bromocryptine. At 18

  7. Ethanolic carbon-11 chemistry: The introduction of green radiochemistry

    International Nuclear Information System (INIS)

    The principles of green chemistry have been applied to a radiochemistry setting. Eleven carbon-11 labeled radiopharmaceuticals have been prepared using ethanol as the only organic solvent throughout the entire manufacturing process. The removal of all other organic solvents from the process simplifies production and quality control (QC) testing, moving our PET Center towards the first example of a green radiochemistry laboratory. All radiopharmaceutical doses prepared are suitable for clinical use. - Highlights: • We report application of the principles of green chemistry to a radiochemistry setting. • Radiopharmaceuticals are prepared using ethanol as the only organic solvent. • Green radiochemistry simplifies production and QC in busy clinical production laboratories. • Residual solvent analysis can be relegated to a quarterly or annual QC test

  8. Radiochirurgie und stereotaktisch fraktionierte Strahlentherapie am Linearbeschleuniger bei Patienten mit Meningeomen;Wertigkeit der L-[Methyl-11C] Methionin (MET)-PET-Untersuchung als Ergänzung zu morphologischen bildgebenden Verfahren wie CT und MRT bei der Erstellung der Therapieplanung und Definition des Zielvolumens der Schädelbasismeningeome

    OpenAIRE

    Ciuchendea-Dobrei, Mihaela-Andreea

    2012-01-01

    Diese Studie untersuchte die Effektivität der stereotaktischen Strahlentherapie von gutartigen Schädelbasismeningeomen sowie die Wertigkeit der Methionin-PET-Bildgebung für die Bestrahlungsplanung. Bei 137 Patienten zeigte sich nach fraktionierter stereotaktischer Strahlentherapie (121 Patienten) bzw. Radiochirurgie (16 Patienten) eine Ansprechrate von 26,3% und eine Tumorkontrollrate von 93% nach einer medianen Nachbeobachtungszeit von 32 Monaten. Die Symptome verbesserten sich in 38% de...

  9. Experience with carbon-11 choline positron emission tomography in prostate carcinoma

    International Nuclear Information System (INIS)

    We investigated the potential of carbon-11 choline positron emission tomography (PET) for the detection of lymph node and bone metastases in prostate cancer. A total of 23 patients were studied (known metastases: 8; suspicion of metastases: 3; primary staging: 12). Whole-body PET imaging was performed 5 min after injection of the tracer and completed within 1 h. Focally increased tracer uptake in bone or abdominal lymph node regions was interpreted as representing tumour involvement. All known bone and lymph node metastases could be recognized by [11C]choline PET. One out of ten negative scans for primary staging was false-negative (lymph node 11C]choline PET is a promising new tool for the primary staging of prostate cancer, with lymph node and bone metastases demonstrating high tracer uptake. Therapeutic management could be influenced by these results in that the technique may permit avoidance of surgical lymph node exploration. (orig.)

  10. Evaluation of clinial usefulness of [sup 11]C-methionine positron emission tomography ([sup 11]C-MET-PET) as a tool for liver functional imaging

    Energy Technology Data Exchange (ETDEWEB)

    Enomoto, Kazuo; Matsui, Yoshifumi; Okazumi, Shinichi (Chiba Univ. (Japan). School of Medicine) (and others)

    1994-03-01

    We studied [sup 11]C-MET-PET in 17 clinical cases, 10 patients with obstructive jaundice and 7 normal volunteers, and analyzed its efficacy for the evaluation of hepatic functional reserve in major hepatectomy candidates. Differential absorption ratio (DAR) of [sup 11]C was compared to the hepatic protein synthesis rate (HPS), which is measured as the incorporation rate of [sup 3]H-labeled leucine in protein fraction, using needle biopsied liver specimen obtained from each hepatic segment. In the cases of normal liver function, DAR was well correlated with HPS. Also in jaundice cases with two exceptions, low HPS segment was demonstrated as low DAR segment. Consequently, MET-PET images could clearly provide functional liver imaging. After injection of [sup 11]C-MET, the increase in rate of radioactivity of [sup 11]C in plasma protein fraction was higher in jaundice cases than in normal volunteers, which is in accord with the results of our former study that cholestatic liver has accelerated protein synthesis rate. In summary, since [sup 11]C-MET-PET could demonstrate liver functional imaging, it might be a possible tool for liver function assessment in major hepatectomy candidates. (author).

  11. Regional myocardial oxygen consumption estimated by carbon-11 acetate and positron emission tomography before and after repetitive ischemia

    DEFF Research Database (Denmark)

    Kofoed, K F; Hansen, P R; Holm, S;

    2011-01-01

    Preserved myocardial oxygen consumption estimated by carbon 11-acetate and positron emission tomography (PET) in myocardial regions with chronic but reversibly depressed contractile function in patients with ischemic heart disease have been suggested to be caused by repeated short episodes of acute...

  12. Studies to label Alfentanil with carbon-11

    Energy Technology Data Exchange (ETDEWEB)

    Feliu, A.L. (Forschungzentrum Juelich GmbH (Germany). Inst. fuer Chemie I)

    1992-09-01

    Methodology applicable to the synthesis of no-carrier-added (O-methyl-{sup 11}C)alfentanil was developed. The sequence consisted of ({sup 11}C)methylation and propionylation of N-aryl-4-(hydroxymethyl)-4-(N-anilino)-piperidines 1a and 1c, followed by the chemoselective hydrolysis of bulk byproducts to facilitate isolation of the NCA carbon-11-labeled product by prep-HPLC. All three steps could be performed without isolation of intermediates in a single reaction vessel. (author).

  13. Methionine sulfoxide reductase A is a stereospecific methionine oxidase

    OpenAIRE

    Lim, Jung Chae; You, Zheng; Kim, Geumsoo; Levine, Rodney L.

    2011-01-01

    Methionine sulfoxide reductase A (MsrA) catalyzes the reduction of methionine sulfoxide to methionine and is specific for the S epimer of methionine sulfoxide. The enzyme participates in defense against oxidative stresses by reducing methionine sulfoxide residues in proteins back to methionine. Because oxidation of methionine residues is reversible, this covalent modification could also function as a mechanism for cellular regulation, provided there exists a stereospecific methionine oxidase....

  14. 11C—甲硫氨酸PET在乳腺癌诊疗中的价值%The clinical and diagnostic value of 11C-methionine PET in breast cancer

    Institute of Scientific and Technical Information of China (English)

    徐志英; 李善春

    2008-01-01

    乳腺癌是我国妇女最常见的恶性肿瘤之一,也是妇女中除肺癌外病死率最高的恶性肿瘤,早期诊断是降低乳腺癌病死率的关键因素.目前,乳腺癌的诊断方法主要是钼靶X线乳腺摄影、超声检查、磁共振成像、细针穿刺活组织检查等.乳腺癌的基因变化导致癌肿血流增加,葡萄糖代谢、氨基酸转运、蛋白质合成、受体表达增加,DNA合成和细胞增殖活跃,并诱导细胞凋亡.PET结果显示.肿瘤部位对18F-氟脱氧葡萄糖(18F-FDG)和11C-甲硫氨酸(11C-MET)摄取均增高而11C-MET合成方便快捷,价格较18F-FDG低,其在乳腺癌中的应用价值国外已有诸多报道.%Breast cancer is one of the most ordinary malignant tumors in woman, and its mortality is only less than that of lung cancer. Early diagnosis is a key to reducing the mortality rate. The commonly used methods to diagnose breast cancer include mammography, ultrasonography, magnetic resonance imaging.Genetic changes of breast cancer comprise increased tumor blood flow, increased levels of glucose metabolism, amino acid transport, protein synthesis receptor expression, enhanced DNA synthesis and cell proliferation, and induction of apoptosis. It shows high 18F-fluoredeoxyglucose(18F-FDG) or methionine uptake in breast cancer, 11C-methionine (11C-MET) has a lower price. PET with 11C-MET has a high prognostic value in breast cancer.

  15. Methionine sulfoxide reductase contributes to meeting dietary methionine requirements

    OpenAIRE

    Zhao, Hang; Kim, Geumsoo; Levine, Rodney L.

    2012-01-01

    Methionine sulfoxide reductases are present in all aerobic organisms. They contribute to antioxidant defenses by reducing methionine sulfoxide in proteins back to methionine. However, the actual in vivo roles of these reductases are not well defined. Since methionine is an essential amino acid in mammals, we hypothesized that methionine sulfoxide reductases may provide a portion of the dietary methionine requirement by recycling methionine sulfoxide. We used a classical bioassay, the growth o...

  16. PET radiopharmaceuticals for neuroreceptor imaging

    Institute of Scientific and Technical Information of China (English)

    2006-01-01

    Routine clinical PET radiopharmaceuticals for the noninvasive imaging of brain receptors, transporters,and enzymes are commonly labeled with positron emitting nuclides such as carbon-11 or fluorine-18. Certain minimal conditions need to be fulfilled for these PET ligands to be used as imaging agents in vivo. Some of these prerequisites are discussed and examples of the most useful clinical PET radiopharmaceuticals that have found application in the central nervous system are reviewed.

  17. Synthesis of carbon-11 labeled dexetimide and levetimide for studying muscarinic acetylcholine receptors

    International Nuclear Information System (INIS)

    The localization and quantitation of the muscarinic acetylcholine receptor (m-AChR) in the living human brain using a non-invasive method, such as positron emission tomography (PET), may provide valuable information about receptor changes which have been observed post mortem in patients with Huntington's chorea and Alzheimer's dementia, as well as normal brain mechanisms mediated by the m-AChR. Although quinuclidinyl benzilate has been radioiodinated and radiomethylatd, the former is not useful with PET and the latter does not penetrate the blood-brain barrier; therefore, the authors chose to radiolabel dexetimide, a ligand which labels m-AChR in vitro and in vivo, and levetimide, its inactive enantiomer. Carbon-11 labeled carbon dioxide is bubbled through a tetrahydrofuran (THF) solution of phenylmagnesium chloride (1 M, l ml) after which 2 mg of lithium aluminium hydride is added in THF (500 μl). After evaporation of the solvent, 48% hydriodic acid (l ml) is added and the solution is heated for 1 minute. Carbon-11 labeled benzyl iodide is extracted into methylene chloride, added to a solution of nor-benzyl dexetimide or levetimide, and heated for several minutes. Purification is accomplished using semi-preparative reverse phase high performance liquid chromatography (HPLC). Analytical HPLC is used to determine the radiochemical purity and specific activity

  18. Synthesis of carbon-11 labeled dexetimide and levetimide for studying muscarinic acetylcholine receptors

    Energy Technology Data Exchange (ETDEWEB)

    Dannals, R.F.; Langstrom, B.; Ravert, H.T.; Wilson, A.A.; Wagner, H.N. Jr.

    1985-05-01

    The localization and quantitation of the muscarinic acetylcholine receptor (m-AChR) in the living human brain using a non-invasive method, such as positron emission tomography (PET), may provide valuable information about receptor changes which have been observed post mortem in patients with Huntington's chorea and Alzheimer's dementia, as well as normal brain mechanisms mediated by the m-AChR. Although quinuclidinyl benzilate has been radioiodinated and radiomethylatd, the former is not useful with PET and the latter does not penetrate the blood-brain barrier; therefore, the authors chose to radiolabel dexetimide, a ligand which labels m-AChR in vitro and in vivo, and levetimide, its inactive enantiomer. Carbon-11 labeled carbon dioxide is bubbled through a tetrahydrofuran (THF) solution of phenylmagnesium chloride (1 M, l ml) after which 2 mg of lithium aluminium hydride is added in THF (500 ..mu..l). After evaporation of the solvent, 48% hydriodic acid (l ml) is added and the solution is heated for 1 minute. Carbon-11 labeled benzyl iodide is extracted into methylene chloride, added to a solution of nor-benzyl dexetimide or levetimide, and heated for several minutes. Purification is accomplished using semi-preparative reverse phase high performance liquid chromatography (HPLC). Analytical HPLC is used to determine the radiochemical purity and specific activity.

  19. Medical application of PET technology

    Energy Technology Data Exchange (ETDEWEB)

    Lim, Sang Moo; Choi, C. W.; An, S. H.; Woo, K. S.; Chung, W. S.; Yang, S. D.; Jun, G. S. and others

    1999-04-01

    We performed following studies using PET technology: 1. Clinical usefulness of [{sup 18}F]FDG whole body PET in malignant disease 2. Clinical usefulness of quantitative evaluation of F-18-FDG 3. Pilot study of C-11 methionine PET in brain tumor 4. PET study in patients with Parkinson's disease 5. A study on the clinical myocardial PET image. PET gives various metabolic information for the living human body, and is very important, new diagnostic modality. The PET study will give us the information of cancer patients such as early detection of cancer, staging, recurrence detection and characterization of cancer. The quantitative analysis using PET could be applied to evaluate the pathophysiology of various diseases and develop new drugs and develop new radiopharmaceuticals.

  20. Medical application of PET technology

    International Nuclear Information System (INIS)

    We performed following studies using PET technology: 1. Clinical usefulness of [18F]FDG whole body PET in malignant disease 2. Clinical usefulness of quantitative evaluation of F-18-FDG 3. Pilot study of C-11 methionine PET in brain tumor 4. PET study in patients with Parkinson's disease 5. A study on the clinical myocardial PET image. PET gives various metabolic information for the living human body, and is very important, new diagnostic modality. The PET study will give us the information of cancer patients such as early detection of cancer, staging, recurrence detection and characterization of cancer. The quantitative analysis using PET could be applied to evaluate the pathophysiology of various diseases and develop new drugs and develop new radiopharmaceuticals

  1. Impact of [11C]Methionine Positron Emission Tomography for Target Definition of Glioblastoma Multiforme in Radiation Therapy Planning

    International Nuclear Information System (INIS)

    Purpose: The purpose of this work was to define the optimal margins for gadolinium-enhanced T1-weighted magnetic resonance imaging (Gd-MRI) and T2-weighted MRI (T2-MRI) for delineating target volumes in planning radiation therapy for postoperative patients with newly diagnosed glioblastoma multiforme (GBM) by comparison to carbon-11-labeled methionine positron emission tomography ([11C]MET-PET) findings. Methods and Materials: Computed tomography (CT), MRI, and [11C]MET-PET were separately performed for radiation therapy planning for 32 patients newly diagnosed with GBM within 2 weeks after undergoing surgery. The extent of Gd-MRI (Gd-enhanced clinical target volume [CTV-Gd]) uptake and that of T2-MRI of the CTV (CTV-T2) were compared with the extent of [11C]MET-PET (CTV--[11C]MET-PET) uptake by using CT--MRI or CT--[11C]MET-PET fusion imaging. We defined CTV-Gd (x mm) and CTV-T2 (x mm) as the x-mm margins (where x = 0, 2, 5, 10, and 20 mm) outside the CTV-Gd and the CTV-T2, respectively. We evaluated the relationship between CTV-Gd (x mm) and CTV-- [11C]MET-PET and the relationship between CTV-T2 (x mm) and CTV-- [11C]MET-PET. Results: The sensitivity of CTV-Gd (20 mm) (86.4%) was significantly higher than that of the other CTV-Gd. The sensitivity of CTV-T2 (20 mm) (96.4%) was significantly higher than that of the other CTV-T2 (x = 0, 2, 5, 10 mm). The highest sensitivity and lowest specificity was found with CTV-T2 (x = 20 mm). Conclusions: It is necessary to use a margin of at least 2 cm for CTV-T2 for the initial target planning of radiation therapy. However, there is a limit to this setting in defining the optimal margin for Gd-MRI and T2-MRI for the precise delineation of target volumes in radiation therapy planning for postoperative patients with GBM.

  2. Photooxidation of Methionine

    Science.gov (United States)

    Lewis, Catherine; Scouten, William H.

    1976-01-01

    Describes an experiment in which the photooxidation of methionine using free methylene blue as the sensitizer is applied to the isolated amino acid or to the methionyl residues of a complex polypeptide. (MLH)

  3. PET studies with L-(1- sup 11 C)tyrosine, L-(methyl- sup 11 C)methionine and sup 18 F-fluorodeoxyglucose in relation to bromocryptine treatment

    Energy Technology Data Exchange (ETDEWEB)

    Daemen, B.J.G.; Elsinga, P.H.; Paans, A.M.J.; Vaalburg, W. (Rijksuniversiteit Groningen (Netherlands). Dept. of Nuclear Medicine); Zwertbroek, R.; Doorenbos, H. (Rijksuniversiteit Groningen (Netherlands). Dept. of Endocrinology)

    1991-07-01

    Aspects of metabolism in prolactinomas were investigated by positron emission tomography using L-(1-{sup 11}C)tyrosine, L-(methyl-{sup 11}C)methionine and fluorodeoxyl glucose 18. Using L-(1-{sup 11}C)tyrosine, four patients were monitored prior to and 18 h after an injection of 50 mg bromocryptine. At 18 h after bromocryptine intervention L-(1-{sup 11}C)tyrosine uptake into tumour was reduced with 28% (P<0.07). A correlation analysis of the bromocryptine-induced decrease in L-(1-{sup 11}C)tyrosine uptake and the reduction of serum prolactin levels indicated that the action of bromocryptine on prolactin synthesis and prolactin release is not coupled. In the untreated situation, the four patients were investigated with {sup 18}FDG as well, but the prolactinomas could not be visualized. Three untreated patients were studied with L-(methyl-{sup 11}C)methionine. The tumour-imaging potential of L-(methyl-{sup 11}C)methionine and L-(1-{sup 11}C)tyrosine appeared to be nearly equivalent for prolactinomas. Unlike prolactinoma tissue, the salivary glands showed a pronounced preference for L-(1-{sup 11}C)tyrosine as compared to L-(methyl-{sup 11}C)methionine. L-(1-{sup 11}C)tyrosine is a valuable tool to obtain information on the metabolism and treatment of prolactinomas. (orig.).

  4. Synthesis of carbon-11 labelled calcium channel antagonists

    International Nuclear Information System (INIS)

    A useful synthetic approach to carbon-11 labelled 1,4-dihydropyridines is described. Carbon-11 labelled calcium channel antagonists 11C-Nifedipine, 11C-Nisoldipine, 11C-nitrendipine and 11C-CF3-Nifedipine were synthesized by a modified Hantzsch method using protected carboxy functions. Deprotection of the carboxylic acids by alkaline hydrolysis followed by conversion into the corresponding potassium salts and subsequent methylation with 11CH3I produced the labelled compounds in very good chemical and radiochemical yields (94%). (author)

  5. Carbon-11 labeled cathepsin K inhibitors: syntheses and preliminary in vivo evaluation.

    Science.gov (United States)

    Rodnick, Melissa E; Shao, Xia; Kozloff, Kenneth M; Scott, Peter J H; Kilbourn, Michael R

    2014-01-01

    Cathepsin K is a cysteine peptidase primarily located in osteoclasts, cells involved in normal growth and remodeling of bone but that are also responsible for bone loss in osteolytic diseases such as osteoporosis. In vivo imaging of cathepsin K may provide a method to assess changes in osteoclast numbers in such disease states. To that end, two high-affinity and selective cathepsin K inhibitors were radiolabeled with carbon-11. In vivo microPET imaging studies demonstrated uptake and prolonged retention of radioactivity in actively growing or remodeling bone regions (e.g., distal ulnar, carpal, distal and proximal humeral, distal femur, proximal tibia, tail vertebrae). Uptake into bone could be blocked by pre- or co-injection of unlabeled ligand, supporting a specific and saturable binding mechanism for radiotracer localization. These proof-of-concept studies indicate that radiolabeled cathepsin K inhibitors may have potential as in vivo imaging radiotracers for assessing changes of osteoclast numbers in osteolytic diseases.

  6. Carbon-11 and fluorine-18 chemistry devoted to molecular probes for imaging the brain with positron emission tomography

    International Nuclear Information System (INIS)

    Exploration of the living human brain in real-time and in a noninvasive way was for centuries only a dream, made, however, possible today with the remarkable development during the four last decades of powerful molecular imaging techniques, and especially positron emission tomography (PET). Molecular PET imaging relies, from a chemical point of view, on the use and preparation of a positron-emitting radiolabelled probe or radiotracer, notably compounds incorporating one of two short-lived radionuclides fluorine-18 (T1/2: 109.8 min) and carbon-11 (T1/2: 20.38 min). The growing availability and interest for the radio-halogen fluorine-18 in radiopharmaceutical chemistry undoubtedly results from its convenient half-life and the successful use in clinical oncology of 2-[18F]fluoro-2-deoxy-D-glucose ([18F]FDG). The special interest of carbon-11 is not only that carbon is present in virtually all biomolecules and drugs allowing therefore for isotopic labelling of their chemical structures but also that a given molecule could be radiolabelled at different functions or sites, permitting to explore (or to take advantage of) in vivo metabolic pathways. PET chemistry includes production of these short-lived radioactive isotopes via nuclear transmutation reactions using a cyclotron, and is directed towards the development of rapid synthetic methods, at the trace level, for the introduction of these nuclides into a molecule, as well as the use of fast purification, analysis and formulation techniques. PET chemistry is the driving force in molecular PET imaging, and this special issue of the Journal of Labelled Compounds and Radiopharmaceuticals, which is strongly chemistry and radiochemistry-oriented, aims at illustrating, be it in part only, the state-of-the-art arsenal of reactions currently available and its potential for the research and development of specific molecular probes labelled with the positron emitters carbon-11 and fluorine-18,with optimal imaging properties for

  7. A COMPARATIVE PET STUDY USING DIFFERENT C-11 LABELED AMINO-ACIDS IN WALKER 256 CARCINOSARCOMA-BEARING RATS

    NARCIS (Netherlands)

    DAEMEN, BJG; ELSINGA, PH; ISHIWATA, K; PAANS, AMJ; VAALBURG, W

    1991-01-01

    In Walker 256 carcinosarcoma-bearing rats, the dynamic distribution of L-[1-C-11]tyrosine, L-[methyl-C-11]methionine, L-[1-C-11]methionine and D-[1-C-11]methionine has been measured by PET. An equivalent tumor-imaging potential was observed for each of the three L-amino acids. Thirty minutes after i

  8. Reduced myocardial carbon-11 hydroxyephedrine retention is associated with poor prognosis in chronic heart failure

    Energy Technology Data Exchange (ETDEWEB)

    Pietilae, M.; Ukkonen, H. [Dept. of Medicine, Turku University Central Hospital (Finland); Turku PET Centre, Turku (Finland); Malminiemi, K. [Dept. of Clinical Chemistry, Tampere University Hospital (Finland); Saraste, M. [Dept. of Clinical Physiology, Turku University Central Hospital (Finland); Naagren, K.; Lehikoinen, P. [Turku PET Centre, Turku (Finland); Voipio-Pulkki, L.-M. [Dept. of Medicine, Turku University Central Hospital (Finland); Dept. of Medicine, Helsinki University Central Hospital (Finland)

    2001-03-01

    Abnormalities of the autonomic nervous system are known to be of prognostic significance in chronic heart failure (CHF). The prognostic value of positron emission tomography (PET) imaging of cardiac autonomic innervation in CHF has not been explored previously. We retrospectively studied the survival data of 46 NYHA class II-III CHF patients (mean LVEF 35%{+-}8%) who had undergone carbon-11 hydroxyephedrine ({sup 11}C-HED) studies at the Turku PET Centre between August 1992 and March 1996. The origin of CHF was dilated cardiomyopathy in 13 of the 46 patients and coronary artery disease with at least one prior myocardial infarction in the remaining 33. Data on causes of death and heart transplantation were collected, and the statistically significant predictors of prognosis were analysed using Cox's proportional hazards regression. During the mean follow-up period of 55{+-}19 months, 11 deaths occurred and two patients underwent heart transplantation successfully. Eleven end-points were classified as cardiac (nine sudden cardiac deaths and two deaths due to progressive heart failure) and two as non-cardiac. When divided into two groups based on the median of {sup 11}C-HED retention (mean 0.184{+-}0.061, median 0.183), eight end-points (death or cardiac transplantation) were reached in the group with {sup 11}C-HED retention below the median and three in the group with {sup 11}C-HED retention above the median (P<0.02). In proportional hazards regression analysis, only peak oxygen uptake (peak VO{sub 2}), left ventricular end-diastolic volume and HED retention were found to be statistically significant. It is concluded that {sup 11}C-HED PET provides independent prognostic information in patients with CHF. (orig.)

  9. Functional diagnosis of cancer using PET

    International Nuclear Information System (INIS)

    Positron emission tomography (PET) can demonstrate increased metabolic demand as visual images, and it provides alternative information for diagnosis that can be used to complement morphological observations. This year, we carried out a study on the usefulness of methionine PET for diagnosis in ovarian cancer. In this study, 13 cases with ovarian tumor, 9 cases were original or recurrent malignant tumors and 4 cases were benign tumors, were studied by both C-11 methionine and FDG PET. All cases received the two PET studies at intervals of one week. C-11 methionine PET showed mean accumulation of 5.26±0.68 (tumor-to-muscle ratio (TMR)) in malignant group and 2.56±0.40 (TMR) in benign group which were significantly different by p-value=0.030. FDG PET showed mean accumulation of 5.80±1.24 standardized uptake value (SUV)) in malignant group and 2.44±0.40 (SUV) in benign group which were significantly different by p-value=0.029. We compared the diagnostic accuracy with C-11 methionine, FDG PET, X-ray CT and CA125 serum level. In C-11 methionine and FDG PET studies, sensitivity, specificity, positive predictive value (PPV) and negative predictive value (NPV) were 88.9%, 75.0%, 88.9% and 75.0%, respectively. C-11 methionine and FDG-PET showed just the same diagnostic accuracy in our cases. In X-ray CT study, sensitivity, specificity, PPV and NPV were 55.6%, 75.0%, 83.3% and 42.9%, respectively. The tumor marker, CA125 level in the serum, showed that sensitivity, specificity, PPV and NPV were 55.6%, 25.0%, 62.5% and 20.0%, respectively. C-11 methionine PET was superior in diagnostic accuracy to usual diagnostic tools such as X-ray CT findings and CA125 serum level, and it had same diagnostic accuracy with FDG PET. C-11 methionine accumulated in normal liver and normal intestine physiologically, some cases showed that FDG was able to detect lesions in these organs better than C-11 methionine. But FDG accumulated in very high level in urinal system form kidney to bladder

  10. Labeled plasma metabolites of L-methyl-hydrogen-3-methionine and L-methyl-carbon-14-methionine in the dog

    International Nuclear Information System (INIS)

    The validity of the mathematical models that attempt to describe positron emission tomography (PET) images produced with [11CH3] methionine in terms of rates of local cerebral protein synthesis has yet to be established. A major objection to current models is that the use of methionine labeled at the methyl position results in the dispersal of the label among various methyl-accepting compounds that appear in the plasma and may then enter the brain. One approach to overcoming this problem has been the use of ''standard'' corrections for the activity contributed to plasma by labeled plasma protein and labeled serine. In order to determine the validity of this approach, the metabolic fate of labeled methionine was studied in six dogs. After injection with either [C3H3] methionine or [14CH3] methionine arterial blood was sampled. Plasma fractions containing protein were separated by fast gel filtration, counted with standard scintillation techniques, and their radioactivity was compared with total plasma radioactivity. Plasma was also separated by high-pressure liquid chromatography into methionine, serine, and nonmethionine or serine-containing fractions. These fractions were counted, and their radioactivity was compared with total plasma radioactivity. Labeled protein appeared in plasma about 20 minutes postinjection and then increased steadily. Labeled serine also appeared and reached a peak value of 9.4 +/- 2.1% of plasma activity at 40 minutes. Of greatest interest was the appearance in later plasma samples of increasing amounts of activity contained in nonserine low molecular weight metabolites of methionine. At 40 minutes, those metabolites made up 27 +/- 6.9% of total plasma activity

  11. Carbon-11 labeled diacylglycerol for signal transduction imaging by positron CT. Evaluation of the quality and safety for clinical use

    Energy Technology Data Exchange (ETDEWEB)

    Fujii, Ryou [Nishijin Hospital, Kyoto (Japan); Imahori, Yoshio; Ido, Tatsuo [and others

    1995-02-01

    To elucidate the synaptic transmission in the neural system, we have been developing fundamental studies for intracellular signaling. For clinical application of carbon-11 labeled diacylglycerol (1-[1-{sup 11}C]butyryl-2-palmitoyl-rac-glycerol: {sup 11}C-DAG) using positron emission computed tomography (PET), we evaluated the quality and the safety of {sup 11}C-DAG as the solution for injection. As a result, {sup 11}C-DAG was synthesized within 50 minutes, including the preparation step for injection. The half life time and energy spectrum of {sup 11}C-DAG were the same as the physical character of carbon-11, and other radioisotopes were not detected. In the quality control, {sup 11}C-DAG solution was negative in the examination of bacterial contamination and the pyrogen test in three successive synthesis procedures. In the acute toxicity test by administration of {sup 11}C-DAG and 100 {mu}mol/kg of non-radioactive DAG to the rat intravenously, the systemic condition of the rat was not changed and no abnormalities were found in any organ 24 hours after administration. These findings indicated the safety of {sup 11}C-DAG solution. Clinical application of {sup 11}C-DAG using positron emission tomography may be useful to elucidate the dysfunction of intracellular signaling in disorders of higher cortical function such as Alzheimer disease. (author).

  12. Synthesis and biological evaluation of carbon-11 and fluorine-18 labeled tracers for in vivo visualization of PDE10A

    International Nuclear Information System (INIS)

    Introduction: In vivo visualization of PDE10A using PET provides a tool to evaluate the role of PDE10A in various neuropsychiatric diseases and can also be useful in the clinical evaluation of PDE10A inhibitor drug candidates. We evaluated several carbon-11 and fluorine-18 labeled PDE10A inhibitors as potential PDE10A PET radioligands. Materials and Methods: [11C]MP10, [11C]JNJ42071965 and four other tracers were developed. Their biodistribution was evaluated in rats. Rat plasma and brain radiometabolites were quantified. Baseline microPET imaging was performed in normal rats and PDE10A knockout (KO) and wild-type (WT) mice. Blocking and displacement studies were conducted. The selectivity of the tracer binding was further studied in an ex vivo autoradiography experiment in PDE10A KO and WT mice. Results: Biodistribution showed brain uptake for all tracers in the striatum and wash-out from the cerebellum. [11C]1 (11C-MP10) had the highest specific uptake index (striatum (S) vs. cerebellum (C) ratios (S/C)-1) at 60 min (7.4). [11C]5 ([11C]JNJ42071965) had a high index at the early time points (1.0 and 3.7 at 2 and 30 min p.i., respectively). The affinity of [11C]4, [18 F]3 and [18 F]6 was too low to visualize PDE10A using microPET. [11C] 2 showed a specific binding, while kinetics of [11C]1 were too slow. [11C]5 reached equilibrium after 10 min (uptake index = 1.2). Blocking and displacement experiments in rats and baseline imaging in PDE10A KO mice showed specific and reversible binding of [11C]5 to PDE10A. Conclusions: We successfully radiolabeled and evaluated six radiotracers for their potential to visualize PDE10A in vivo. While [11C]1 had the highest striatal specific uptake index, its slow kinetics likely compromise clinical use of this tracer. [11C]5 has a relatively high striatum-to-background ratio and fast kinetic profile, which makes it a valuable carbon-11 alternative

  13. Investigation on the role of integrated PET/MRI for target volume definition and radiotherapy planning in patients with high grade glioma

    International Nuclear Information System (INIS)

    Purpose: To evaluate the impact of fluid-attenuated-inversion-recovery MRI (FLAIR/MRI) and Carbon-11-labeled-methionine PET (11C-MET-PET) on high grade glioma (HGG) tumor volume delineation for radiotherapy planning. Material and methods: Sixty-nine patients with HGG were evaluated. The clinical target volumes (CTV1, generated by adding a 10 mm margin to FLAIRMRI area, CTV2 by adding a 20 mm margin to enhanced T1MRI) and biological target volume (BTV) were delineated on pre-operative MRI images and 11CMETPET respectively. Results: The overlap between CTV1 and CTV2 showed a low correlation between the two volumes with CTV1 not always fully included into the CTV2. In all cases the whole BTV was included into the CTV1, while in 35/69 patients (50%) part of BTV was outside the CTV2 despite larger margins were added. In all cases recurrences were within the CTV1 volume and in 19/38 (50%) partially outside the CTV2. In all patients relapse corresponded to the BTV area. Conclusions: Our data suggest that the target volume definition using FLAIR–MRI is more adequate compared to enhanced T1MRI. 11C-METPET uptake could help identify microscopic residual areas

  14. Synthesis and positron emission tomography studies of carbon-11-labeled imatinib (Gleevec)

    Energy Technology Data Exchange (ETDEWEB)

    Kil, Kun-Eek [Medical Department, Brookhaven National Laboratory, Upton, NY 11973 (United States); Department of Chemistry, State University of New York at Stony Brook, Stony Brook, NY 11794-3400 (United States); Ding Yushin [Department of Radiology, Yale University School of Medicine, New Haven, CT 06520-8048 (United States); Lin Kuoshyan [Department of Radiology, University of Pittsburgh, Pittsburgh, PA 15213 (United States); Alexoff, David [Medical Department, Brookhaven National Laboratory, Upton, NY 11973 (United States); Kim, Sung Won [Medical Department, Brookhaven National Laboratory, Upton, NY 11973 (United States); Department of Chemistry, State University of New York at Stony Brook, Stony Brook, NY 11794-3400 (United States); Shea, Colleen [Medical Department, Brookhaven National Laboratory, Upton, NY 11973 (United States); Xu Youwen [Medical Department, Brookhaven National Laboratory, Upton, NY 11973 (United States); Muench, Lisa [Medical Department, Brookhaven National Laboratory, Upton, NY 11973 (United States); Fowler, Joanna S. [Medical Department, Brookhaven National Laboratory, Upton, NY 11973 (United States) and Department of Chemistry, State University of New York at Stony Brook, Stony Brook, NY 11794-3400 (United States)]. E-mail: fowler@bnl.gov

    2007-02-15

    Introduction: Imatinib mesylate (Gleevec) is a well known drug for treating chronic myeloid leukemia and gastrointestinal stromal tumors. Its active ingredient, imatinib ([4-[(4-methyl-1-piperazinyl)methyl]-N-[4-methyl-3-[[4-(3-pyridyl) -2-pyrimidinyl]amino]phenyl]benzamide), blocks the activity of several tyrosine kinases. Here we labeled imatinib with carbon-11 as a tool for determining the drug distribution and pharmacokinetics of imatinib, and we carried out positron emission tomography (PET) studies in baboons. Methods: [N-{sup 11}C-methyl]imatinib was synthesized from [{sup 11}C]methyl iodide and norimatinib was synthesized by the demethylation of imatinib (isolated from Gleevec tablets) according to a patent procedure [Collins JM, Klecker RW Jr, Anderson LW. Imaging of drug accumulation as a guide to antitumor therapy. US Patent 20030198594A1, 2003]. Norimatinib was also synthesized from the corresponding amine and acid. PET studies were carried out in three baboons to measure pharmacokinetics in the brain and peripheral organs and to determine the effect of a therapeutic dose of imatinib. Log D and plasma protein binding were also measured. Results: [N-{sup 11}C-methyl]imatinib uptake in the brain is negligible (consistent with P-glycoprotein-mediated efflux); it peaks and clears rapidly from the heart, lungs and spleen. Peak uptake and clearance occur more slowly in the liver and kidneys, followed by accumulation in the gallbladder and urinary bladder. Pretreatment with imatinib did not change uptake in the heart, lungs, kidneys and spleen, and increased uptake in the liver and gallbladder. Conclusions: [N-{sup 11}C-methyl]imatinib has potential for assessing the regional distribution and kinetics of imatinib in the human body to determine whether the drug targets tumors and to identify other organs to which the drug or its labeled metabolites distribute. Paired with tracers such as 2'deoxy-2'-[{sup 18}F]fluoro-D-glucose ({sup 18}FDG) and 3&apos

  15. Non selective transport of (/sup 11/C-methyl)-L-and D-methionine into a malignant glioma. Case report

    Energy Technology Data Exchange (ETDEWEB)

    Schober, O.; Duden, C.; Meyer, G.J.; Mueller, J.A.; Hundeshagen, H.

    1987-05-01

    Images obtained by X-ray CT, brain scintigraphy /sup 99m/Tc-DTPA and positron emission tomography (PET) with (/sup 11/C-methyl)-L- and D-methionine in a case of malignant glioma are presented, showing good agreement of PET and CT findings, in particular nearly identical localization of L- and D-methionine accumulation, whereas the blood brain barrier is only slightly disturbed. In a greater number of patients the amount of accumulated stereoisomers do not differ on a significant level, indicating that a raised transport rate mediated by a carrier of low stereospecifity seems to contribute substantially to the increased uptake of (/sup 11/C-methyl)-L-methionine in human brain tumors. Several cerebral functions and diseases have been studied with positron emission tomography (PET), which represents a clinical tool for visualizing metabolic activities rather than morphologic lesions; Mazziotta et al. 1986). With regard to the malignancy of brain tumors showed a correlation between tumor grade and its glucose metabolism measured with /sup 18/F-fluorodeoxyglucose. An increased uptake of (/sup 11/C-methyl)-L-methionine into tumor tissue has also been described; Schober and Bustany developed a model for quantitative determination of protein synthesis, even postulating that methionine incorporation into protein in brain tumors correlates with grade of malignancy. We do not believe that the uptake of (/sup 11/C--methyl)-L-methionine mainly reflects protein synthesis, because (/sup 11/C-methyl)-D-methionine is accumulated in normal brain tissue and intracranial tumors in nearly the same manner as (/sup 11/C-methyl)-L-methionine, the physiological substrate for protein synthesizing enzymes (Meyer et al. 1985; Duden et al. unpublished). (Abstract Truncated)

  16. In vivo evaluation of carbon-11-labelled non-sarcosine-based glycine transporter 1 inhibitors in mice and conscious monkeys

    Energy Technology Data Exchange (ETDEWEB)

    Toyohara, Jun [Division of Clinical Neuroscience, Chiba University Center for Forensic Mental Health, Chiba, Japan 260-8670 (Japan); Positron Medical Center, Tokyo Metropolitan Institute of Gerontology, Tokyo, Japan 173-0022 (Japan); Ishiwata, Kiichi; Sakata, Muneyuki [Positron Medical Center, Tokyo Metropolitan Institute of Gerontology, Tokyo, Japan 173-0022 (Japan); Wu, Jin [Division of Clinical Neuroscience, Chiba University Center for Forensic Mental Health, Chiba, Japan 260-8670 (Japan); Nishiyama, Shingo; Tsukada, Hideo [Central Research Laboratory, Hamamatsu Photonics K.K., Shizuoka, Japan 434-8601 (Japan); Hashimoto, Kenji, E-mail: hashimoto@faculty.chiba-u.j [Division of Clinical Neuroscience, Chiba University Center for Forensic Mental Health, Chiba, Japan 260-8670 (Japan)

    2011-05-15

    Introduction: Glycine transporter 1 (GlyT-1) is an attractive target in positron emission tomography (PET) studies. Here, we report the in vivo evaluation of three carbon-11-labelled non-sarcosine-type GlyT-1 inhibitors - [{sup 11}C]SA1, [{sup 11}C]SA2 and [{sup 11}C]SA3 - as novel PET tracers for GlyT-1. Methods: The regional brain distributions of the three compounds in mice were studied at baseline and under receptor-blockade conditions with co-injection of carrier loading or pretreatment with an excess of selective GlyT-1 inhibitors (ALX-5407 and SSR504734). Metabolic stability was investigated by radio high-performance liquid chromatography. Dynamic PET scans in conscious monkeys were performed with/without selective GlyT-1 inhibitors. Results: The IC{sub 50} values of SA1, SA2 and SA3 were 9.0, 6400 and 39.7 nM, respectively. The regional brain uptakes of [{sup 11}C]SA1 and [{sup 11}C]SA3 in mice were heterogeneous and consistent with the known distribution of GlyT-1. [{sup 11}C]SA2 showed low and homogeneous uptake in the brain. Most radioactivity in the brain was detected in unchanged form, although peripherally these compounds were degraded. Carrier loading decreased the uptake of [{sup 11}C]SA1 in GlyT-1-rich regions. However, similar reductions were not observed with [{sup 11}C]SA3. Pretreatment with ALX-5407 decreased the uptake of [{sup 11}C]SA1 in GlyT-1-rich regions. In the monkey at baseline, regional brain uptake of [{sup 11}C]SA1 was heterogeneous and consistent with the known GlyT-1 distribution. Pretreatment with selective GlyT-1 inhibitors significantly decreased the distribution volume ratio of [{sup 11}C] SA1 in GlyT-1-rich regions. Conclusions: [{sup 11}C]SA1 has the most suitable profile among the three carbon-11-labelled GlyT-1 inhibitors. Lead optimization of [{sup 11}C]SA1 structure will be required to achieve in vivo selective GlyT-1 imaging.

  17. 21 CFR 582.5475 - Methionine.

    Science.gov (United States)

    2010-04-01

    ... 21 Food and Drugs 6 2010-04-01 2010-04-01 false Methionine. 582.5475 Section 582.5475 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) ANIMAL DRUGS... 1 § 582.5475 Methionine. (a) Product. Methionine. (b) (c) Limitations, restrictions, or...

  18. Carbon-11 labelled analogs of alanine by the Strecker synthesis

    Energy Technology Data Exchange (ETDEWEB)

    Prenant, C.; Theobald, A.; Siegel, T.; Joachim, J.; Weber, K.; Haberkorn, U.; Oberdorfer, F. [Deutsches Krebsforschungszentrum, Heidelberg (Germany)

    1995-06-01

    Derivatives of alanine, {alpha}-[2-sup(11)C]aminoisobutyric acid 1a and {alpha}-(N-methyl)-[2-{sup 11} C]aminoisobutyric acid 1b were prepared for the in-vivo study of amino acid transport phenomena by positron-emission-tomography (PET). Compounds 1a and 1b were obtained by a Zelinski-Stadnikoff variant of the Strecker {alpha}-amino acid synthesis from in-situ formed [{sup 11} C]acetone in presence of sodium cyanide and either ammonium sulfate (for 1a) or methylamine hydrochloride (for 1b). The complete preparation required 50 min from the end of [{sup 11}C]CO{sub 2} production, and delivered 1.2 - 2 GBq of labelled product for application (2.4 -4%); not corrected for decay; related to trapped [{sup C}]CO{sub 2}. The specific activity of the labelled products was 16 to 20 GBq{center_dot}{mu}mol{sup -1}. The radiochemical and chemical purity of the preparations was greater than 98%. (Author).

  19. Methionine Uptake and Required Radiation Dose to Control Glioblastoma

    Energy Technology Data Exchange (ETDEWEB)

    Iuchi, Toshihiko, E-mail: tiuchi@chiba-cc.jp [Division of Neurological Surgery, Chiba Cancer Center, Chiba (Japan); Hatano, Kazuo [Division of Radiation Oncology, Tokyo Bay Advanced Imaging and Radiation Oncology Clinic, Makuhari, Chiba (Japan); Uchino, Yoshio [Division of Nuclear Medicine, Chiba Ryogo Center, Chiba (Japan); Itami, Makiko [Division of Surgical Pathology, Chiba Cancer Center, Chiba (Japan); Hasegawa, Yuzo; Kawasaki, Koichiro; Sakaida, Tsukasa [Division of Neurological Surgery, Chiba Cancer Center, Chiba (Japan); Hara, Ryusuke [Division of Radiation Oncology, Chiba Cancer Center, Chiba (Japan)

    2015-09-01

    Purpose: The purpose of this study was to retrospectively assess the feasibility of radiation therapy planning for glioblastoma multiforme (GBM) based on the use of methionine (MET) positron emission tomography (PET), and the correlation among MET uptake, radiation dose, and tumor control. Methods and Materials: Twenty-two patients with GBM who underwent MET-PET prior to radiation therapy were enrolled. MET uptake in 30 regions of interest (ROIs) from 22 GBMs, biologically effective doses (BEDs) for the ROIs and their ratios (MET uptake:BED) were compared in terms of whether the ROIs were controlled for >12 months. Results: MET uptake was significantly correlated with tumor control (odds ratio [OR], 10.0; P=.005); however, there was a higher level of correlation between MET uptake:BED ratio and tumor control (OR, 40.0; P<.0001). These data indicated that the required BEDs for controlling the ROIs could be predicted in terms of MET uptake; BED could be calculated as [34.0 × MET uptake] Gy from the optimal threshold of the MET uptake:BED ratio for tumor control. Conclusions: Target delineation based on MET-PET was demonstrated to be feasible for radiation therapy treatment planning. MET-PET could not only provide precise visualization of infiltrating tumor cells but also predict the required radiation doses to control target regions.

  20. Groningen experience in production and application of fluorine-18 and carbon-11 labeled radiopharmaceuticals

    International Nuclear Information System (INIS)

    In this presentation the preparation of these tracers (fluorine-18 and carbon-11 labeled radiopharmaceuticals), as well as the present stage of development and evaluation, and the potential application in oncology will be discussed. (author)

  1. Tracer transport and metabolism in a patient with juvenile pilocytic astrocytoma. A PET study

    NARCIS (Netherlands)

    Roelcke, U; Radu, EW; Hausmann, O; Vontobel, P; Maguire, RP; Leenders, KL

    1998-01-01

    We studied a patient with juvenile pilocytic astrocytoma (JPA) using positron emission tomography (PET), F-18-fluorodeoxyglucose (FDG), C-11-methionine (MET), and (82)Rubidium (RUB). Non-linear fitting and multiple time graphical plotting of the dynamic PET data revealed values for tumor plasma volu

  2. Quantitation of cellular metabolic fluxes of methionine.

    Science.gov (United States)

    Shlomi, Tomer; Fan, Jing; Tang, Baiqing; Kruger, Warren D; Rabinowitz, Joshua D

    2014-02-01

    Methionine is an essential proteogenic amino acid. In addition, it is a methyl donor for DNA and protein methylation and a propylamine donor for polyamine biosynthesis. Both the methyl and propylamine donation pathways involve metabolic cycles, and methods are needed to quantitate these cycles. Here, we describe an analytical approach for quantifying methionine metabolic fluxes that accounts for the mixing of intracellular and extracellular methionine pools. We observe that such mixing prevents isotope tracing experiments from reaching the steady state due to the large size of the media pools and hence precludes the use of standard stationary metabolic flux analysis. Our approach is based on feeding cells with (13)C methionine and measuring the isotope-labeling kinetics of both intracellular and extracellular methionine by liquid chromatography-mass spectrometry (LC-MS). We apply this method to quantify methionine metabolism in a human fibrosarcoma cell line and study how methionine salvage pathway enzyme methylthioadenosine phosphorylase (MTAP), frequently deleted in cancer, affects methionine metabolism. We find that both transmethylation and propylamine transfer fluxes amount to roughly 15% of the net methionine uptake, with no major changes due to MTAP deletion. Our method further enables the quantification of flux through the pro-tumorigenic enzyme ornithine decarboxylase, and this flux increases 2-fold following MTAP deletion. The analytical approach used to quantify methionine metabolic fluxes is applicable for other metabolic systems affected by mixing of intracellular and extracellular metabolite pools.

  3. Methionine sulfoximine intensifies cancer anorexia.

    Science.gov (United States)

    Chance, W T; Zhang, F S; Fischer, J E

    1991-05-01

    Consistent anorexia was first observed 33 days after inoculating Fischer 344 rats with methylcholanthrene-induced sarcoma. Daily treatment of a similar group of rats with the glutamine synthetase inhibitor, methionine sulfoximine, elicited significant reductions of feeding by day 29 at a dose that had no effect on nontumor-bearing rats. Blood concentrations of ammonia were elevated in both groups of tumor-bearing rats and brain ammonia level was increased in the methionine sulfoximine-treated tumor-bearing rats. Forebrain concentrations of tyrosine, tryptophan, DOPAC and 5-HIAA were elevated in both groups of tumor-bearing rats. Since ammonia is detoxified through the glutamine synthetase reaction, these results suggest that blood and brain ammonia concentrations are more important than the neurochemical consequences of ammonia detoxification for the etiology of cancer anorexia.

  4. Methionine PET/CT Studies In Patients With Cancer

    Science.gov (United States)

    2016-06-07

    Brain Tumors and /or Solid Tumors Including:; Brain Stem Glioma; High Grade CNS Tumors; Ependymoma; Medulloblastoma; Craniopharyngioma; Low Grade CNS Tumors; Hodgkin Lymphoma; Non Hodgkin Lymphoma; Ewing Sarcoma; Osteosarcoma; Rhabdomyosarcoma; Neuroblastoma; Other

  5. Pet Health

    Science.gov (United States)

    Pets can add fun, companionship and a feeling of safety to your life. Before getting a pet, think carefully about which animal is best for ... is each family member looking for in a pet? Who will take care of it? Does anyone ...

  6. Comparative evaluation of transport mechanisms of trans-1-amino-3-[¹⁸F]fluorocyclobutanecarboxylic acid and L-[methyl-¹¹C]methionine in human glioma cell lines.

    Science.gov (United States)

    Ono, Masahiro; Oka, Shuntaro; Okudaira, Hiroyuki; Schuster, David M; Goodman, Mark M; Kawai, Keiichi; Shirakami, Yoshifumi

    2013-10-16

    Positron emission tomography (PET) with amino acid tracers is useful for the visualization and assessment of therapeutic effects on gliomas. Our purpose is to elucidate the transport mechanisms of trans-1-amino-3-[¹⁸F]fluorocyclobutanecarboxylic acid (anti-[¹⁸F]FACBC) and L-[methyl-¹¹C]methionine ([¹¹C]Met) in normal human astrocytes (NHA), low-grade (Hs683, SW1088), and high-grade (U87MG, T98G) human glioma cell lines. Because the short half-lives of fluorine-18 and carbon-11 are inconvenient for in vitro experiments, trans-1-amino-3-fluoro[1-¹⁴C]cyclobutanecarboxylic acid (anti-[¹⁴C]FACBC) and L-[methyl-¹⁴C]methionine ([¹⁴C]Met) were used instead of the PET tracers. Time-course uptake experiments showed that uptake of anti-[¹⁴C]FACBC was 1.4-2.6 times higher than that of [¹⁴C]Met in NHA and low-grade glioma cells, and was almost equal to that of [¹⁴C]Met in high-grade glioma cells. To identify the amino acid transporters (AATs) involved in the transport of anti-[¹⁴C]FACBC and [¹⁴C]Met, we carried out competitive inhibition experiments using synthetic/naturally-occurring amino acids as inhibitors. We found that anti-[¹⁴C]FACBC uptake in the presence of Na⁺ was strongly inhibited by L-glutamine and L-serine (the substrates for ASC system AATs), whereas L-phenylalanine and 2-amino-bicyclo[2,2,1]heptane-2-carboxylic acid (BCH, the substrates for L system AATs) robustly inhibited Na⁺-independent anti-[¹⁴C]FACBC uptake. Regardless of Na⁺, [¹⁴C]Met uptake was inhibited strongly by L-phenylalanine and BCH. Moreover, the exchange transport activity of L-glutamine for anti-[¹⁴C]FACBC was stronger than that of BCH in the presence of Na⁺, whereas that for [¹⁴C]Met was almost equal to BCH. These results demonstrate that ASC and L are important transport systems for anti-[¹⁸F]FACBC uptake, while system L is predominantly involved in [¹¹C]Met transport in human astrocytes and glioma cells.

  7. New developments in radiotracers for PET

    International Nuclear Information System (INIS)

    PET (Positron Emission Tomography) is a medical imaging method in which a radiotracer tagged with a short-lived positron emitting isotope is used to track a specific biochemical process or the distribution and kinetics of a drug in a living human or animal subject. PET can be applied to an almost limitless variety of problems in biology and medicine because of the chemical flexibility of positron emitters such as carbon-11 (half-life: 20.4 min) and fluorine-18 (half-life: 110 min). Today radiotracers have been developed for probing a diversity of biochemical transformations including blood flow, sugar metabolism, neurotransmission and enzyme activity. In addition PET is finding increasing application in the study of therapeutic drugs and substances of abuse. Dopamine metabolism has been an area of intense interest because of derangements in diseases such as schizophrenia and Parkinson's disease. This has been probed from a number of perspectives with carbon-11 and fluorine-18 labeled tracers which participate selectively in dopamine metabolism, or bind to the dopamine reuptake system or post-synaptic receptors. Advances in the design of highly selective radiotracers, in rapid organic synthesis and sophisticated analytical methods and in mechanistic biochemical studies in vivo have all contributed to the advancement of PET and to its application to new problems in basic and clinical research

  8. Imaging Spectrum and Pitfalls of 11C-Methionine Positron Emission Tomography in a Series of Patients with Intracranial Lesions

    Science.gov (United States)

    Matsuda, Hiroshi; Kubota, Kazoo

    2016-01-01

    11C-methionine (Met) positron emission tomography (PET) is one of the most commonly used PET tracers for evaluating brain tumors. However, few reports have described tips and pitfalls of 11C-Met PET for general practitioners. Physiological 11C-Met uptake, anatomical variations, vascular disorders, non-tumorous lesions such as inflammation or dysplasia, benign brain tumors and patient condition during 11C-Met PET examination can potentially affect the image interpretation and cause false positives and negatives. These pitfalls in the interpretation of 11C-Met PET images are important for not only nuclear medicine physicians but also general radiologists. Familiarity with the spectrum and pitfalls of 11C-Met images could help prevent unfavorable clinical results caused by misdiagnoses. PMID:27134530

  9. Non FDG PET

    Energy Technology Data Exchange (ETDEWEB)

    Nanni, C., E-mail: cristina.nanni@aosp.bo.i [Nuclear Medicine Unit, Policlinico S.Orsola, University of Bologna, Bologna (Italy); Fantini, L.; Nicolini, S.; Fanti, S. [Nuclear Medicine Unit, Policlinico S.Orsola, University of Bologna, Bologna (Italy)

    2010-07-15

    2- [{sup 18}F]-fluoro-2-deoxy-D-glucose (FDG) is the radiopharmaceutical most frequently used for clinical positron emission tomography (PET). However, FDG cannot be used for many oncological, cardiological, or neurological conditions, either because the abnormal tissue does not concentrate it, or because the tissues under investigation demonstrate high physiological glucose uptake. Consequently, alternative PET tracers have been produced and introduced into clinical practice. The most important compounds in routine practice are {sup 11}C-choline and {sup 18}F-choline, mainly for the evaluation of prostate cancer; {sup 1}C-methionine for brain tumours; {sup 118}F-DOPA ({sup 18}F- deoxiphenilalanine) for neuroendocrine tumours and movement disorders; {sup 68}Ga-DOTANOC (tetraazacyclododecanetetraacetic acid-[1-Nal3]-octreotide) and other somatostatin analogues for neuroendocrine tumours; 11C-acetate for prostate cancer and hepatic masses and 18F-FLT (3'-deoxy-3'-fluorothymidine) for a number of malignant tumours. Another impetus for the development of new tracers is to enable the investigation of biological processes in tumours other than glucose metabolism. This is especially important in the field of response assessment, where there are new agents that are targeted more specifically at angiogenesis, hypoxia, apoptosis and other processes.

  10. Methionine-sensitive glycolysis in transformed cells.

    Science.gov (United States)

    Boerner, P; Racker, E

    1985-10-01

    Glycolysis in several tumor cell lines grown in tissue culture was inhibited by methionine. Kirsten murine sarcoma virus-transformed rat kidney cells (K-NRK) were inhibited 60-75% by 10 mM methionine, whereas normal rat kidney (NRK-49F) cells showed little or no inhibition. Inhibition of glycolysis in K-NRK cells was manifest 2-4 hr after exposure to the amino acid. Glycolysis in a chemically transformed cell line of Madin-Darby canine kidney cells was also sensitive to methionine, but maximal inhibition (75%) required 18-24 hr of incubation with the amino acid. Under the same conditions glycolysis in the nontransformed canine cells was less than 20% inhibited by methionine. In Ehrlich ascites tumor cells grown in tissue culture, 10 mM methionine inhibited glycolysis by about 50%. Inhibition of glycolysis, even by 50 mM methionine, was rapidly reversible. Within 2 hr after removal of methionine the rate of glycolytic activity was restored to that observed in control cells. Furthermore, inhibition by methionine required a minimum level (7%) of serum in the growth medium and inhibition was not sensitive to cycloheximide. Only amino acids that are transported by system A (including the nonmetabolized analogue methylaminoisobutyric acid) specifically inhibited glycolysis in tumor cells. The only exception was phenylalanine, which was toxic to both transformed and normal cell lines.

  11. Methionine metabolism in Yucatan miniature swine.

    Science.gov (United States)

    McBreairty, Laura E

    2016-06-01

    Methionine is an essential amino acid which when not incorporated into protein, can be converted to S-adenosylmethionine, the universal methyl donor in over 200 transmethylation reactions, which include creatine and phosphatidylcholine (PC) synthesis, as well as deoxyribonucleic acid (DNA) methylation. Following transmethylation, homocysteine is formed, which can be converted to cysteine via transsulfuration or remethylated to methionine by receiving a methyl group from folate or betaine. Changes to methyl group availability in utero can lead to permanent changes in epigenetic patterns of DNA methylation, which has been implicated in "fetal programming", a phenomenon associated with poor nutrition during fetal development that results in low birth weight and disease in later life. It has been shown that programming can also occur in the neonate. Our global objective was to understand how the variability of nutrients involved in methionine metabolism can affect methionine and methyl group availability. We hypothesize that nutrients that converge on methionine metabolism can affect methionine availability for its various functions. In this thesis, we used intrauterine growth restricted (IUGR) piglets to investigate whether a global nutritional insult in utero can lead to a perturbed methionine metabolism. Our results demonstrate that IUGR piglets have a lower capacity to dispose of homocysteine via both transsulfuration and remethylation pathways, as well as a lower incorporation of methyl groups into PC. The second objective of this thesis was to determine whether variation in methionine supply and demand can affect methionine availability. We demonstrated that stimulating either acute or chronic creatine synthesis leads to lower methyl incorporation into protein and PC in pigs. Furthermore, when methionine is limiting, supplementation with either folate or betaine leads to higher methionine availability for protein synthesis. Finally, because creatine is

  12. Simultaneous PET/MR imaging in a human brain PET/MR system in 50 patients-Current state of image quality

    Energy Technology Data Exchange (ETDEWEB)

    Schwenzer, N.F., E-mail: nina.schwenzer@med.uni-tuebingen.de [Department of Diagnostic and Interventional Radiology, Eberhard-Karls University Tuebingen, Tuebingen (Germany); Stegger, L., E-mail: stegger@gmx.net [Department of Nuclear Medicine and European Institute for Molecular Imaging, University of Muenster, Muenster (Germany); Bisdas, S., E-mail: sbisdas@gmail.com [Department of Diagnostic and Interventional Neuroradiology, Eberhard-Karls University Tuebingen, Tuebingen (Germany); Schraml, C., E-mail: christina.schraml@med.uni-tuebingen.de [Department of Diagnostic and Interventional Radiology, Eberhard-Karls University Tuebingen, Tuebingen (Germany); Kolb, A., E-mail: armin.kolb@med.uni-tuebingen.de [Laboratory for Preclinical Imaging and Imaging Technology of the Werner Siemens-Foundation, Department of Preclinical Imaging and Radiopharmacy, Eberhard-Karls University Tuebingen, Tuebingen (Germany); Boss, A., E-mail: Andreas.Boss@usz.ch [Department of Diagnostic and Interventional Radiology, Eberhard-Karls University Tuebingen, Tuebingen (Germany); Institute of Diagnostic and Interventional Radiology, University Hospital Zuerich, Zuerich (Switzerland); Mueller, M., E-mail: mark.mueller@med.uni-tuebingen.de [Department of Nuclear Medicine, Eberhard-Karls University Tuebingen, Tuebingen (Germany); and others

    2012-11-15

    Objectives: The present work illustrates the current state of image quality and diagnostic accuracy in a new hybrid BrainPET/MR. Materials and methods: 50 patients with intracranial masses, head and upper neck tumors or neurodegenerative diseases were examined with a hybrid BrainPET/MR consisting of a conventional 3T MR system and an MR-compatible PET insert. Directly before PET/MR, all patients underwent a PET/CT examination with either [{sup 18}F]-FDG, [{sup 11}C]-methionine or [{sup 68}Ga]-DOTATOC. In addition to anatomical MR scans, functional sequences were performed including diffusion tensor imaging (DTI), arterial spin labeling (ASL) and proton-spectroscopy. Image quality score of MR imaging was evaluated using a 4-point-scale. PET data quality was assessed by evaluating FDG-uptake and tumor delineation with [{sup 11}C]-methionine and [{sup 68}Ga]-DOTATOC. FDG uptake quantification accuracy was evaluated by means of ROI analysis (right and left frontal and temporo-occipital lobes). The asymmetry indices and ratios between frontal and occipital ROIs were compared. Results: In 45/50 patients, PET/MR examination was successful. Visual analysis revealed a diagnostic image quality of anatomical MR imaging (mean quality score T2 FSE: 1.27 {+-} 0.54; FLAIR: 1.38 {+-} 0.61). ASL and proton-spectroscopy was possible in all cases. In DTI, dental artifacts lead to one non-diagnostic dataset (mean quality score DTI: 1.32 {+-} 0.69; ASL: 1.10 {+-} 0.31). PET datasets of PET/MR and PET/CT offered comparable tumor delineation with [{sup 11}C]-methionine; additional lesions were found in 2/8 [{sup 68}Ga]-DOTATOC-PET in the PET/MR. Mean asymmetry index revealed a high accordance between PET/MR and PET/CT (1.5 {+-} 2.2% vs. 0.9 {+-} 3.6%; mean ratio (frontal/parieto-occipital) 0.93 {+-} 0.08 vs. 0.96 {+-} 0.05), respectively. Conclusions: The hybrid BrainPET/MR allows for molecular, anatomical and functional imaging with uncompromised MR image quality and a high accordance

  13. 21 CFR 172.399 - Zinc methionine sulfate.

    Science.gov (United States)

    2010-04-01

    ... 21 Food and Drugs 3 2010-04-01 2009-04-01 true Zinc methionine sulfate. 172.399 Section 172.399... CONSUMPTION Special Dietary and Nutritional Additives § 172.399 Zinc methionine sulfate. Zinc methionine...-methionine in purified water. (b) The additive meets the following specifications: Zinc content—19 to...

  14. Interaction of genetic mechanisms regulating methionine concentration in maize grain

    Science.gov (United States)

    Methionine is a limiting amino acid in poultry diets so methionine supplementation is typically required to meet nutritional demands. Maize varieties with increased methionine levels have been developed utilizing three different approaches: i.) increased levels of the methionine-rich 10 kDa zein, ii...

  15. Preparation, crystallization and preliminary X-ray analysis of the methionine synthase (MetE) from Streptococcus mutans

    Energy Technology Data Exchange (ETDEWEB)

    Fu, Tian-Min; Zhang, Xiao-Yan; Li, Lan-Fen; Liang, Yu-He, E-mail: liangyh@pku.edu.cn; Su, Xiao-Dong [National Laboratory of Protein Engineering and Plant Genetic Engineering, Peking University, Beijing 100871 (China); Department of Biochemistry and Molecular Biology, College of Life Sciences, Peking University, Beijing 100871 (China)

    2006-10-01

    Methionine synthase (MetE) from S. mutans was expressed, purified and crystallized. Diffraction data have been collected to 2.2 Å resolution. The Streptococcus mutans metE gene encodes methionine synthase (MetE), which catalyzes the direct transfer of a methyl group from methyltetrahydrofolate to homocysteine in the last step of methionine synthesis. metE was cloned into pET28a and the gene product was expressed at high levels in the Escherichia coli strain BL21 (DE3). MetE was purified to homogeneity using Ni{sup 2+}-chelating chromatography followed by size-exclusion chromatography. Crystals of the protein were obtained by the hanging-drop vapour-diffusion method and diffracted to 2.2 Å resolution. The crystal belongs to space group P2{sub 1}, with unit-cell parameters a = 52.85, b = 99.48, c = 77.88 Å, β = 94.55°.

  16. Methionine depletion modulates the antitumor and antimetastatic efficacy of ethionine.

    Science.gov (United States)

    Guo, H; Tan, Y; Kubota, T; Moossa, A R; Hoffman, R M

    1996-01-01

    The elevated methionine requirement for the growth of tumors, termed methionine dependence, is a potentially highly effective therapeutic target. To attack this target we are developing anti-methionine chemotherapy. In this study of anti-methionine chemotherapy we have observed that the methionine analog ethionine is synergistic with methionine depletion in arresting the growth of the Yoshida sarcoma both in vitro and when transplanted to nude mice. In contrast, ethionine in vitro in a methionine-containing medium is not effective against Yoshida sarcoma cells. Similarly, ethionine administered along with a methionine-containing diet is ineffective against the Yoshida sarcoma growing in nude mice. A methionine-depleted diet alone is only partially effective against tumor growth. The Yoshida sarcoma gave rise to metastases in 75% of the- organs observed in the mice on the methionine-containing diet, and 43 % of the organs in the mice on the methionine-free diet. In striking contrast, no metastases were observed in the ethionine-treated animals on the methionine-free diet. Anti-methionine chemotherapy consisting of dietary methionine depletion and ethionine administration caused an initial weight loss but the animals weight stabilized resulting in no animal deaths. The synergism of ethionine and methionine depletion is markedly similar in vitro and in vivo suggesting the observed efficacy is due to the specific anti-methionine targeting. Thus methionine depletion highly potentiates the anti-tumor and anti-metastatic effectiveness of ethionine suggesting that anti-methionine chemotherapy consisting of methionine depletion as a modulator of methionine analogs holds great promise as a new, tumor-selective therapeutic approach.

  17. Methionine residues as endogenous antioxidants in proteins

    OpenAIRE

    Levine, Rodney L.; Mosoni, Laurent; Berlett, Barbara S.; Stadtman, Earl R.

    1996-01-01

    Cysteine and methionine are the two sulfur-containing residues normally found in proteins. Cysteine residues function in the catalytic cycle of many enzymes, and they can form disulfide bonds that contribute to protein structure. In contrast, the specific functions of methionine residues are not known. We propose that methionine residues constitute an important antioxidant defense mechanism. A variety of oxidants react readily with methionine to form methionine sulfoxi...

  18. Benzodiazepine receptor quantification in vivo in humans using [11C]flumazenil and PET

    DEFF Research Database (Denmark)

    Lassen, N A; Bartenstein, P A; Lammertsma, A A;

    1995-01-01

    Carbon-11-labeled flumazenil combined with positron emission tomography (PET) was used to measure the concentration (Bmax) of the benzodiazepine (Bz) receptor in the brain and its equilibrium dissociation constant (KD) for flumazenil in five normal subjects. The steady-state approach was used inj...

  19. Biosynthetic preparation of 35-S labelled methionine

    International Nuclear Information System (INIS)

    High specific activity methionine with sulfur-35 was prepared in our laboratory by growing Baker's yeast cells, in a medium containing 35S-sulfate. L-S35 methionine was prepared from the acid hydrolyzate of the proteins by chromatography on whatman paper. The specific activity was determined using o-phtaladehyde as a fluorophore to form a fluorescent complex. The specific activity was found to be usually greater than 800 Ci/mmol. (Author)

  20. Diabetic Pets

    Science.gov (United States)

    ... health or management, contact your veterinarian. In addition, diabetic pets should be monitored for long-term complications such as cataracts, which commonly develop in diabetic dogs and cats. Other problems that can occur ...

  1. Senior Pets

    Science.gov (United States)

    ... Future AVMA Meeting Dates Meetings & CE Calendar Symposiums & Summits Pet Health Awareness Events About AVMA Who We ... and small dogs are generally considered “senior” at seven years of age. Larger breed dogs tend to ...

  2. 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.

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

    International Nuclear Information System (INIS)

    A number of reviews, many of them recent, have appeared on various aspects of 11C, 18F and 13N-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

  4. Metabolism of 5-methylthioribose to methionine

    International Nuclear Information System (INIS)

    During ethylene biosynthesis, the H3CS-group of S-adenosylmethionine is released as 5'-methylthioadenosine, which is recycled to methionine via 5-methylthioribose (MTR). In mungbean hypocotyls and cell-free extracts of avocado, [14C]MTR was converted into labeled methionine via 2-keto-4-methylthiobutyric acid (KMB) and 2-hydroxy-4-methylthiobutyric acid (HMB), as intermediates. Incubation of [ribose-U-14C]MTR with avocado extract resulted in the production of [14C]formate, indicating the conversion of MTR to KMB involves a loss of formate, presumably from C-1 of MTR. Tracer studies showed that KMB was converted readily in vivo and in vitro to methionine, while HMB was converted much more slowly. The conversion of KMB to methionine by dialyzed avocado extract requires an amino donor. Among several potential donors examined, L-glutamine was the most efficient. Anaerobiosis inhibited only partially the oxidation of MTR to formate, KMB/HMB, and methionine by avocado extract. The role of O2 in the conversion of MTR to methionine is discussed

  5. PURIFICATION OF L-METHIONINE AND N-ACETYL-D-METHIONINE FROM THE MIXTURE OF ENZYMATICALLY DEACYLATED N-ACETYL-DL-METHIONINE

    Institute of Scientific and Technical Information of China (English)

    YAN Xiaomin; ZHAO Lin; SHAO Jianhui; TAN Xin; SONG Zhengxiao

    2004-01-01

    N-acetyl-D-methionine, NaAc and the remains of N-acetyl-L-methionine dramatically affect the purification of L-methionine when purified from the mixture of enzymatically deacylated N-acetyl-DL-methionine, leading to a low yield conventionally. Here, this paper reports a successful separation and purification of both L-methionine and N-acetyl-D-methionine by an H ion-exchange column. The pH, L-Met concentration and the ratio between the content of sodium cation and the ion-exchange capacity were optimized to obtain the maximum yield. Experimental results indicate that, under the optimized conditions, the yields of L-methionine and N-acetyl-D-methionine can reach as high as 85% and 75%, respectively.

  6. Positron Emission Tomography (PET)

    Science.gov (United States)

    Welch, M. J.

    1990-01-01

    Positron emission tomography (PET) assesses biochemical processes in the living subject, producing images of function rather than form. Using PET, physicians are able to obtain not the anatomical information provided by other medical imaging techniques, but pictures of physiological activity. In metaphoric terms, traditional imaging methods supply a map of the body's roadways, its, anatomy; PET shows the traffic along those paths, its biochemistry. This document discusses the principles of PET, the radiopharmaceuticals in PET, PET research, clinical applications of PET, the cost of PET, training of individuals for PET, the role of the United States Department of Energy in PET, and the futures of PET.

  7. Positron Emission Tomography (PET)

    Energy Technology Data Exchange (ETDEWEB)

    Welch, M.J.

    1990-01-01

    Positron emission tomography (PET) assesses biochemical processes in the living subject, producing images of function rather than form. Using PET, physicians are able to obtain not the anatomical information provided by other medical imaging techniques, but pictures of physiological activity. In metaphoric terms, traditional imaging methods supply a map of the body's roadways, its, anatomy; PET shows the traffic along those paths, its biochemistry. This document discusses the principles of PET, the radiopharmaceuticals in PET, PET research, clinical applications of PET, the cost of PET, training of individuals for PET, the role of the United States Department of Energy in PET, and the futures of PET. 22 figs.

  8. Positron Emission Tomography (PET)

    International Nuclear Information System (INIS)

    Positron emission tomography (PET) assesses biochemical processes in the living subject, producing images of function rather than form. Using PET, physicians are able to obtain not the anatomical information provided by other medical imaging techniques, but pictures of physiological activity. In metaphoric terms, traditional imaging methods supply a map of the body's roadways, its, anatomy; PET shows the traffic along those paths, its biochemistry. This document discusses the principles of PET, the radiopharmaceuticals in PET, PET research, clinical applications of PET, the cost of PET, training of individuals for PET, the role of the United States Department of Energy in PET, and the futures of PET. 22 figs

  9. Comparison of autologous 111In-leukocytes, 18F-FDG, 11C-methionine, 11C-PK11195 and 68Ga-citrate for diagnostic nuclear imaging in a juvenile porcine haematogenous Staphylococcus aureus osteomyelitis model

    DEFF Research Database (Denmark)

    Nielsen, Ole Lerberg; Afzelius, Pia; Bender, Dirk;

    2015-01-01

    The aim of this study was to compare (111)In-labeled leukocyte single-photon emission computed tomography (SPECT) and (18)F-fluorodeoxyglucose ((18)F-FDG) positron emission tomography (PET) to PET with tracers that potentially could improve detection of osteomyelitis. We chose (11)C-methionine, (11...

  10. Morphological and molecular imaging of hematogenously inoculated and disseminated Staphylococcus aureus lesions in domestic juvenile female pigs by PET/CT. The bio-distribution of the radionuclides 18F-FDG, 11C-methionine, 11C-PK11195, and 68Ga-citrate in pigs is presented

    DEFF Research Database (Denmark)

    Afzelius, Pia; Nielsen, Ole Lerberg; Alstrup, Aage Kristian Olsen;

    2016-01-01

    . Bacteremia may give rise to bacterial spread to different tissues such as e.g. heart, joints, spleen, bones, and skin/soft tissue. Staphylococcus aureus is a conditional pathogen: it is carried on many humans and animals without symptoms, but it is also able to cause serious diseases like osteomyelitis...... tracers that potentially could improve uncovering of infectious lesions in soft tissues. We chose 11C-methionine, 11C-PK11195, and 68Ga-citrate as tracers and validated their diagnostic utility in a porcine model. Four juvenile 14-15 weeks old female domestic pigs were scanned seven days after intra...

  11. Imaging spectrum and pitfalls of {sup 11}C-methionine position emission tomography in a series of patients with intracranial lesions

    Energy Technology Data Exchange (ETDEWEB)

    Ito, Kimiteru [Dept. of Radiology, Tokyo Metropolitan Geriatric Hospital and Institute of Gerontology, Tokyo (Japan); Matsuda, Hiroshi [Integrative Brain Imaging Center, National Center of Neurology and Psychiatry, Tokyo (Japan); Kubota, Kazoo [Div. of Nuclear Medicine, National Center for Global Health and Medicine, Tokyo (Japan)

    2016-06-15

    {sup 11}C-methionine (Met) positron emission tomography (PET) is one of the most commonly used PET tracers for evaluating brain tumors. However, few reports have described tips and pitfalls of {sup 11}C-Met PET for general practitioners. Physiological {sup 11}C-Met uptake, anatomical variations, vascular disorders, non-tumorous lesions such as inflammation or dysplasia, benign brain tumors and patient condition during {sup 11}C-Met PET examination can potentially affect the image interpretation and cause false positives and negatives. These pitfalls in the interpretation of {sup 11}C-Met PET images are important for not only nuclear medicine physicians but also general radiologists. Familiarity with the spectrum and pitfalls of {sup 11}C-Met images could help prevent unfavorable clinical results caused by misdiagnoses.

  12. The dynamics of methionine supply and demand during early development.

    Science.gov (United States)

    McBreairty, Laura E; Bertolo, Robert F

    2016-06-01

    Methionine is an indispensable amino acid that, when not incorporated into protein, is converted into the methyl donor S-adenosylmethionine as entry into the methionine cycle. Following transmethylation, homocysteine is either remethylated to reform methionine or irreversibly trans-sulfurated to form cysteine. Methionine flux to transmethylation and to protein synthesis are both high in the neonate and this review focuses on the dynamics of methionine supply and demand during early development, when growth requires expansion of pools of protein and transmethylation products such as creatine and phosphatidylcholine (PC). The nutrients folate and betaine (derived from choline) donate a methyl group during remethylation, providing an endogenous supply of methionine to meet the methionine demand. During early development, variability in the dietary supply of these methionine cycle-related nutrients can affect both the supply and the demand of methionine. For example, a greater need for creatine synthesis can limit methionine availability for protein and PC synthesis, whereas increased availability of remethylation nutrients can increase protein synthesis if dietary methionine is limiting. Moreover, changes to methyl group availability early in life can lead to permanent changes in epigenetic patterns of DNA methylation, which have been implicated in the early origins of adult disease phenomena. This review aims to summarize how changes in methyl supply and demand can affect the availability of methionine for various functions and highlights the importance of variability in methionine-related nutrients in the infant diet. PMID:27177124

  13. A review of methionine dependency and the role of methionine restriction in cancer growth control and life-span extension.

    Science.gov (United States)

    Cavuoto, Paul; Fenech, Michael F

    2012-10-01

    Methionine is an essential amino acid with many key roles in mammalian metabolism such as protein synthesis, methylation of DNA and polyamine synthesis. Restriction of methionine may be an important strategy in cancer growth control particularly in cancers that exhibit dependence on methionine for survival and proliferation. Methionine dependence in cancer may be due to one or a combination of deletions, polymorphisms or alterations in expression of genes in the methionine de novo and salvage pathways. Cancer cells with these defects are unable to regenerate methionine via these pathways. Defects in the metabolism of folate may also contribute to the methionine dependence phenotype in cancer. Selective killing of methionine dependent cancer cells in co-culture with normal cells has been demonstrated using culture media deficient in methionine. Several animal studies utilizing a methionine restricted diet have reported inhibition of cancer growth and extension of a healthy life-span. In humans, vegan diets, which can be low in methionine, may prove to be a useful nutritional strategy in cancer growth control. The development of methioninase which depletes circulating levels of methionine may be another useful strategy in limiting cancer growth. The application of nutritional methionine restriction and methioninase in combination with chemotherapeutic regimens is the current focus of clinical studies.

  14. Pet Therapy.

    Science.gov (United States)

    Kavanagh, Kim

    1994-01-01

    This resource guide presents information on a variety of ways that animals can be used as a therapeutic modality with people having disabilities. Aspects addressed include: pet ownership and selection criteria; dogs (including service dogs, hearing/signal dogs, seeing leader dogs, and social/specialty dogs); horseriding for both therapy and fun;…

  15. Targeted Disruption of the Methionine Synthase Gene in Mice

    OpenAIRE

    Swanson, Deborah A.; Liu, Mei-Lan; Baker, Priscilla J.; Garrett, Lisa; Stitzel, Michael; Wu, Jianmin; Harris, Michelle; Banerjee, Ruma; Shane, Barry; Brody, Lawrence C

    2001-01-01

    Alterations in homocysteine, methionine, folate, and/or B12 homeostasis have been associated with neural tube defects, cardiovascular disease, and cancer. Methionine synthase, one of only two mammalian enzymes known to require vitamin B12 as a cofactor, lies at the intersection of these metabolic pathways. This enzyme catalyzes the transfer of a methyl group from 5-methyl-tetrahydrofolate to homocysteine, generating tetrahydrofolate and methionine. Human patients with methionine synthase defi...

  16. Efficiency of Positron Emission Tomography with 18F-Fluorodeoxyglucose, 11С-Methionine and 82Rb-Chloride in Differential Diagnosis of Lung Tumors and Some Inflammatory Pulmonary Diseases

    Directory of Open Access Journals (Sweden)

    Tlostanova М.S.

    2014-09-01

    Full Text Available The aim of the investigation was to study the informativeness of positron emission tomography (PET using 18F-FDG, 11С-methionine and 82Rb-chloride in differential diagnosis of tumor and some inflammatory pulmonary diseases. Materials and Methods. PET findings of 378 patients with lung tumors and inflammatory pulmonary diseases were studied. PET with 18F-FDG and 11С-methionine were performed 120 and 15 min, respectively, after their intravenous administration. PET with 82Rb-chloride was performed 1 min after distant intravenous administration. Quantitative processing of PET findings regardless the medication used included visual image analysis and calculation of Standardized Uptake Value (SUV in healthy pulmonary parenchyma and in lesion. Results. SUV in patients with lung cancer in PET with 18F-FDG and 11С-methionine were higher than metabolic activity in an inflammation region, while in PET with 82Rb-chloride, SUV levels were significantly higher in the foci of inflammation than in malignant tumors. The patients with benign tumors and most patients with focal pneumofibrosis in pulmonary tissue consolidation area were recorded to have background distribution of radiopharmaceuticals. It enabled to reliably differentiate benign tumors and focal pneumofibrosis from lung cancer regardless the medications used. Conclusion. The obtained data on the informativeness of positron emission tomography performed using 11С-methionine suggest high diagnostic value of the technique in the differential diagnosis of lung cancer, neuroendocrine tumors, benign tumors and inflammatory diseases. Despite good imaging potential PET with 82Rb-chloride is unreasonable in differentiation of lung tumors and inflammatory pulmonary diseases.

  17. Absolute quantitation of iodine-123 epidepride kinetics using single-photon emission tomography: comparison with carbon-11 epidepride and positron emission tomography

    Energy Technology Data Exchange (ETDEWEB)

    Almeida, P. [CEA, 91 - Orsay (France). Service Hospitalier Frederic Joliot; Hospital Garcia de Orta, Servico de Medicina Nuclear, Pragal, Almada (Portugal); Ribeiro, M.J. [CEA, 91 - Orsay (France). Service Hospitalier Frederic Joliot; Servico de Biofisica, IBILI, Faculdade de Medicina de Coimbra (Portugal); Bottlaender, M.; Loc' h, C.; Langer, O.; Strul, D.; Maziere, B.; Bendriem, B. [CEA, 91 - Orsay (France). Service Hospitalier Frederic Joliot; Hugonnard, P.; Grangeat, P. [CEA Centre d' Etudes Nucleaires de Grenoble, 38 (France). Lab. d' Electronique de Technologie et d' Instrumentation

    1999-12-01

    Epidepride labelled with iodine-123 is a suitable probe for the in vivo imaging of striatal and extrastriatal dopamine D{sub 2} receptors using single-photon emission tomography (SPET). Recently, this molecule has also been labelled with carbon-11. The goal of this work was to develop a method allowing the in vivo quantification of radioactivity uptake in baboon brain using SPET and to validate it using positron emission tomography (PET). SPET studies were performed in Papio anubis baboons using {sup 123}I-epidepride. Emission and transmission measurements were acquired on a dual-headed system with variable head angulation and low-energy ultra-high resolution (LEUHR) collimation. The imaging protocol consisted of one transmission measurement (24 min, heads at 90 ), obtained with two sliding line sources of gadolinium-153 prior to injection of 0.21-0.46 GBq of {sup 123}I-epidepride, and 12 emission measurements starting 5 min post injection. For scatter correction (SC) we used a dual-window method adapted to {sup 123}I. Collimator blurring correction (CBC) was done by deconvolution in Fourier space and attenuation correction (AT) was applied on a preliminary (CBC) filtered back-projection reconstruction using 12 iterations of a preconditioned, regularized minimal residual algorithm. For each reconstruction, a calibration factor was derived from a uniform cylinder filled with a {sup 123}I solution of a known radioactivity concentration. Calibration and baboon images were systematically built with the same reconstruction parameters. Uncorrected (UNC) and (AT), (SC+AT) and (SC+CBC+AT) corrected images were compared. PET acquisitions using 0.11-0.44 GBq of {sup 11}C-epidepride were performed on the same baboons and used as a reference. The radioactive concentrations expressed in percent of the injected dose per 100 ml (%ID/100 ml) obtained after (SC+CBC+AT) in SPET are in good agreement with those obtained with PET and {sup 11}C-epidepride. A method for the in vivo

  18. Absolute quantitation of iodine-123 epidepride kinetics using single-photon emission tomography: comparison with carbon-11 epidepride and positron emission tomography.

    Science.gov (United States)

    Almeida, P; Ribeiro, M J; Bottlaender, M; Loc'h, C; Langer, O; Strul, D; Hugonnard, P; Grangeat, P; Mazière, B; Bendriem, B

    1999-12-01

    Epidepride labelled with iodine-123 is a suitable probe for the in vivo imaging of striatal and extrastriatal dopamine D2 receptors using single-photon emission tomography (SPET). Recently, this molecule has also been labelled with carbon-11. The goal of this work was to develop a method allowing the in vivo quantification of radioactivity uptake in baboon brain using SPET and to validate it using positron emission tomography (PET). SPET studies were performed in Papio anubis baboons using 123I-epidepride. Emission and transmission measurements were acquired on a dual-headed system with variable head angulation and low-energy ultra-high resolution (LEUHR) collimation. The imaging protocol consisted of one transmission measurement (24 min, heads at 90 degrees), obtained with two sliding line sources of gadolinium-153 prior to injection of 0.21-0.46 GBq of 123I-epidepride, and 12 emission measurements starting 5 min post injection. For scatter correction (SC) we used a dual-window method adapted to 123I. Collimator blurring correction (CBC) was done by deconvolution in Fourier space and attenuation correction (AT) was applied on a preliminary (CBC) filtered back-projection reconstruction using 12 iterations of a preconditioned, regularized minimal residual algorithm. For each reconstruction, a calibration factor was derived from a uniform cylinder filled with a 123I solution of a known radioactivity concentration. Calibration and baboon images were systematically built with the same reconstruction parameters. Uncorrected (UNC) and (AT), (SC + AT) and (SC + CBC + AT) corrected images were compared. PET acquisitions using 0.11-0.44 GBq of 11C-epidepride were performed on the same baboons and used as a reference. The radioactive concentrations expressed in percent of the injected dose per 100 ml (% ID/100 ml) obtained after (SC + CBC + AT) in SPET are in good agreement with those obtained with PET and 11C-epidepride. A method for the in vivo absolute quantitation of 123

  19. Absolute quantitation of iodine-123 epidepride kinetics using single-photon emission tomography: comparison with carbon-11 epidepride and positron emission tomography

    International Nuclear Information System (INIS)

    Epidepride labelled with iodine-123 is a suitable probe for the in vivo imaging of striatal and extrastriatal dopamine D2 receptors using single-photon emission tomography (SPET). Recently, this molecule has also been labelled with carbon-11. The goal of this work was to develop a method allowing the in vivo quantification of radioactivity uptake in baboon brain using SPET and to validate it using positron emission tomography (PET). SPET studies were performed in Papio anubis baboons using 123I-epidepride. Emission and transmission measurements were acquired on a dual-headed system with variable head angulation and low-energy ultra-high resolution (LEUHR) collimation. The imaging protocol consisted of one transmission measurement (24 min, heads at 90 ), obtained with two sliding line sources of gadolinium-153 prior to injection of 0.21-0.46 GBq of 123I-epidepride, and 12 emission measurements starting 5 min post injection. For scatter correction (SC) we used a dual-window method adapted to 123I. Collimator blurring correction (CBC) was done by deconvolution in Fourier space and attenuation correction (AT) was applied on a preliminary (CBC) filtered back-projection reconstruction using 12 iterations of a preconditioned, regularized minimal residual algorithm. For each reconstruction, a calibration factor was derived from a uniform cylinder filled with a 123I solution of a known radioactivity concentration. Calibration and baboon images were systematically built with the same reconstruction parameters. Uncorrected (UNC) and (AT), (SC+AT) and (SC+CBC+AT) corrected images were compared. PET acquisitions using 0.11-0.44 GBq of 11C-epidepride were performed on the same baboons and used as a reference. The radioactive concentrations expressed in percent of the injected dose per 100 ml (%ID/100 ml) obtained after (SC+CBC+AT) in SPET are in good agreement with those obtained with PET and 11C-epidepride. A method for the in vivo absolute quantitation of 123I

  20. Pet Allergy Quiz

    Science.gov (United States)

    ... people with pet allergy do better with a dog that has short hair or sheds less. Question 2 Pet allergies are triggered by the hair on a pet. True False False: Pet allergies are caused by an allergen found on the pet’s skin (dander), saliva or urine. Question 3 Symptoms of pet allergy ...

  1. Dynamic study of methionine positron emission tomography in patients with glioblastoma with oligodendroglial components.

    Science.gov (United States)

    Yano, Hirohito; Ohe, Naoyuki; Nakayama, Noriyuki; Nomura, Yu-Ichi; Miwa, Kazuhiro; Shinoda, Jun; Iwama, Toru

    2015-10-01

    Anaplastic oligoastrocytoma (AOA) with necrosis is classified as glioblastoma (GBM) with oligodendroglioma component (GBMO), according to the 2007 World Health Organization classification. The prognosis of GBMO remains controversial because definitive diagnostic criteria regarding the percentage of the oligodendroglial components (OC) in the GBM do not exist. We previously reported dynamic methionine (MET) positron emission tomography (PET) in patients with these tumors. A significant decrease in the MET signal was seen in oligodendrocytic tumors, in contrast to a significant MET increase in GBMs. In this study, we analyzed the dynamic MET PET signal in four patients with primary (n = 2) and secondary (n = 2) GBMOs. Static PET scanning was performed in three consecutive phases. Both cases of primary GBMOs and one case of secondary GBMO presented with a gradual decrease in MET PET signal over the consecutive phases. In contrast, the remaining case of secondary GBMO presented with a pattern of slight increase. It is likely that the dynamic change of MET in patients with GBMO resemble those in patients with oligodendroglial tumor, however, further studies are needed to confirm them. We discuss the mechanisms from a viewpoint of pathological findings.

  2. Chemoenzymatic Synthesis of (36)S Isotopologues of Methionine and S-Adenosyl-L-methionine.

    Science.gov (United States)

    Poulin, Myles B; Du, Quan; Schramm, Vern L

    2015-05-15

    Substrates containing isotope labels at specific atoms are required for transition-state analysis based on the measurement of multiple kinetic isotope effects.(36)S-labeled l-methionine and S-adenosyl-l-methionine were synthesized from elemental sulfur using a chemoenzymatic approach with >98% (36)S enrichment. This method provides access to previously inaccessible sulfur isotope-labeled substrates for sulfur kinetic isotope effect studies.

  3. Performance of broilers fed with different levels of methionine hydroxy analogue and DL-methionine

    Directory of Open Access Journals (Sweden)

    Meirelles HT

    2003-01-01

    Full Text Available One-day-old male Ross chicks were used in an experiment designed to compare two methionine sources, DL-methionine and methionine hydroxy analogue free acid (MHA-FA, and four different levels: 0.41; 0.47; 0.53; 0.59% (starter diet; 0.35; 0.41; 0.47; 0.53% (grower diet; and 0.30; 0.36; 0.42; 0.48% (finisher diet. One thousand two hundred and eighty chicks were housed in 32 experimental floor-pens (40 birds each and fed 8 experimental diets based on corn and soybean meal for 47 days. The effects of methionine sources and levels were evaluated by performance data, carcass and cut yields, feather yield and abdominal fat content. Data were analyzed as a completely randomized design in a 2x4 factorial arrangement (2 sources and 4 levels, with 8 treatments and 4 repetitions. Analysis of variance was performed using PROC GLM of SAS©. Data indicated DL-methionine to be more effective in promoting growth than MHA-FA, and weight gain increased numerically in response to increasing levels of methionine in all phases.

  4. Cyclotron-produced radioisotopes and their clinical use at the Austin PET Centre

    Energy Technology Data Exchange (ETDEWEB)

    Tochon-Danguy, H.J. [Centre for PET, Melbourne, VIC (Australia). Austin and Repatriation Medical Centre

    1997-12-31

    A Centre for Positron Emission Tomography (PET) has been established within the Department of Nuclear Medicine at the Austin and Repatriation Medical Centre in Melbourne. PET is a non-invasive technique based on the use of biologically relevant compounds labelled with short-lived positron-emitting radionuclides such as carbon-11, nitrogen-13, oxygen-15 and fluorine-18. The basic equipment consists of a medical cyclotron (10 MeV proton and 5 MeV deuteron), six lead-shielded hot cells with associated radiochemistry facilities and a whole body PET scanner. During its first five years of operation, the Melbourne PET Centre, has pursued a strong radiolabelling development program, leading to an ambitious clinical program in neurology, oncology and cardiology. This presentation will describe the basic principles of the PET technique and review the cyclotron-produced radioisotopes and radiopharmaceuticals. Radiolabelling development programs and clinical applications are also addressed. 30 refs., 1 tab., 1 fig.

  5. Cyclotron-produced radioisotopes and their clinical use at the Austin PET Centre

    International Nuclear Information System (INIS)

    A Centre for Positron Emission Tomography (PET) has been established within the Department of Nuclear Medicine at the Austin and Repatriation Medical Centre in Melbourne. PET is a non-invasive technique based on the use of biologically relevant compounds labelled with short-lived positron-emitting radionuclides such as carbon-11, nitrogen-13, oxygen-15 and fluorine-18. The basic equipment consists of a medical cyclotron (10 MeV proton and 5 MeV deuteron), six lead-shielded hot cells with associated radiochemistry facilities and a whole body PET scanner. During its first five years of operation, the Melbourne PET Centre, has pursued a strong radiolabelling development program, leading to an ambitious clinical program in neurology, oncology and cardiology. This presentation will describe the basic principles of the PET technique and review the cyclotron-produced radioisotopes and radiopharmaceuticals. Radiolabelling development programs and clinical applications are also addressed

  6. Atmospheric tracer study of the emissions from the University of Michigan Cyclotron/PET Facility

    International Nuclear Information System (INIS)

    The University of Michigan (U of M) Cyclotron/Positron Emission Tomography (PET) facility consists of a cyclotron (Model CS-30, The Cyclotron Corporation), radiochemistry laboratory, and Pet scanner. Accelerator-produced radioactive materials, such as, carbon-11 and oxygen-15 are typically emitted from the Cyclotron/PET facility through short stacks located on the roof. This project studied the dispersion of emissions from the facility within the medical complex. To achieve this purpose, the research project had three phases: a physical modeling study; a preliminary field smoke release study; and, a field study using a tracer gas to simulate emission dispersion from the U of M Cyclotron/PET facility vault stack. The objective was to determine normalized concentrations, under selected wind directions and speeds, for use in establishing radionuclide concentrations at the air intakes of the Cyclotron/PET facility and surrounding buildings and at selected ground-level locations

  7. PET/CT in radiation therapy planning; PET/CT in der Strahlentherapieplanung

    Energy Technology Data Exchange (ETDEWEB)

    Grosu, A.L. [Klinik und Poliklinik fuer Strahlentherapie und Radiologische Onkologie, Klinikum rechts der Isar, Technische Univ. Muenchen (Germany); Krause, B.J. [Klinik fuer Nuklearmedizin, Klinikum rechts der Isar, Technische Univ. Muenchen (Germany); Nestle, U. [Klinik fuer Nuklearmedizin, Universitaetsklinikum des Saarlandes, Homburg/Saar (Germany)

    2006-09-15

    Regarding treatment planning in radiotherapy PET offers advantages in terms of tumor delineation and the description of biological processes. To define the real impact of this investigation in radiation treatment planning, following experimental, clinical and cost/benefit analysis are required. FDG-PET has a significant impact on GTV and PTV delineation in lung cancer and can detect lymph node involvement and differentiation of malignant tissue from atelectasis. In high-grade gliomas and meningiomas, methionine-PET helps to define the GTV and differentiate tumor from normal tissue. In head and neck cancer, cervix cancer and prostate cancer the value of FDG-PET for radiation treatment planning is still under investigation. For example, FDG-PET can be superior to CT and MRI in the detection of lymph node metastases in head and neck, unknown primary cancer and differentiation of viable tumor tissue after treatment. Therefore, it could play an important role in GTV definition and sparing of normal tissue. For other entities like gastro-intestinal cancer, lymphomas, sarcoma etc., the data of the literature are yet insufficient. The imaging of hypoxia, cell proliferation, angiogenesis, apoptosis and gene expression leads to the identification of different areas of a biologically heterogeneous tumor mass that can be individually targeted using IMRT. In addition, a biological dose distribution can be generated, the so-called dose painting. However, systematical experimental and clinical trials are necessary to validate this hypothesis. (orig.)

  8. American Pet Culture

    Institute of Scientific and Technical Information of China (English)

    海焰

    2007-01-01

    In America you can find dogs,cats, horses,monkeys, snakes and even pigs in almost every family.They are their pets.Americans love pets and look on them as a part of the family.Sometimes pet owners dress their pets in fashionable clothes.They even buy toys for their pets.Americans love their pets as their children, sometimes even better.

  9. Factors influencing methionine toxicity in young bobwhite quail

    Science.gov (United States)

    Serafin, J.A.

    1981-01-01

    Young Bobwhite quail (Colinus virginianus) were fed low and adequate protein purified diets with and without excess methionine to evaluate factors affecting methionine toxicity. Growth of quail fed an adequate protein (27%) diet, without supplemental glycine, was depressed by 1.75% and 2.25% excess methionine. Supplemental glycine (.3%) alleviated growth depression caused by 2.25% excess methionine. Quail fed 1.75% and 2.25% excess methionine developed signs of toxicity characterized by weakness, a lowered, outstretched neck when moving, and ataxia. In addition, quail would fall on their sides when disturbed and spin with their heads retracted. These conditions were transient in nature. Growth of quail fed a low protein (18.9%) diet was depressed by 1% and 1.5% excess methionine and DL-homocystine. Quail fed 1% and 1.5% excess methionine in this diet also developed signs of toxicity, the incidence of which was greater and the duration longer than occurred with quail fed adequate protein. Supplementing a low protein (20.15%) diet with .3% or .6% glycine or threonine or a combination of these amino acids did not alleviate growth depression caused by 1.5% excess methionine; however, 2% and 3% supplemental glycine were somewhat effective. Supplements of glycine (2%, 3%) and threonine (1%) completely reversed growth depression from 1% excess methionine but did not influence growth of controls, indicating that both amino acids counteract methionine toxicity. Both glycine and threonine alone improved growth by about the same extent in diets with 1% or 1.5% excess methionine; however, these amino acids alleviated less than 30% of the growth depression resulting from 1.5% excess methionine. The effectiveness of glycine in alleviating methionine toxicity in a low protein diet was decreased, and hemoglobin levels were depressed with 1.5% excess methionine compared to less amounts.

  10. Experimental and theoretical proton affinities of methionine, methionine sulfoxide and their N- and C-terminal derivatives

    Science.gov (United States)

    Lioe, Hadi; O'Hair, Richard A. J.; Gronert, Scott; Austin, Allen; Reid, Gavin E.

    2007-11-01

    The proton affinities of methionine, methionine sulfoxide and their derivatives (methionine methyl ester, methionine sulfoxide methyl ester, methionine methyl amide, methionine sulfoxide methyl amide, N-acetyl methionine, N-acetyl methionine sulfoxide, N-acetyl methionine methyl ester, N-acetyl methionine sulfoxide methyl ester, N-acetyl methionine methyl amide and N-acetyl methionine sulfoxide methyl amide) were experimentally determined using the kinetic method, in which proton bound dimers formed via electrospray ionization (ESI) were subjected to collision induced dissociation (CID) in a triple quadrupole mass spectrometer. In addition, theoretical calculations carried out at the MP2/6-311 + G(2d,p)//B3LYP/6-31 + G(d,p) level of theory to determine the global minima of the neutral and protonated species of all derivatives studied, were used to predict theoretical proton affinities. The density function theory calculations not only support the experimental proton affinities, but also provide structural insights into the types of hydrogen bonding that stabilize the neutral and protonated methionine or methionine sulfoxide derivatives. Comparison of the proton affinities of the various methionine and methionine sulfoxide derivatives reveals that: (i) oxidation of methionine derivatives to methionine sulfoxide derivatives results in an increase in proton affinity due to higher intrinsic proton affinity and an increase in the ring size formed through charge complexation of the sulfoxide group, which allows more efficient hydrogen bonding compared to the sulfide group; (ii) C-terminal modification by methyl esterification or methyl amidation increases the proton affinity in the order of methyl amide > methyl ester > carboxylic acid due to improved charge stabilization; (iii) N-terminal modification by N-acetylation decreases proton affinity of the derivatives due to lower intrinsic proton affinity of the N-acetyl group as well as due to stabilization of the attached

  11. L-Methionine inhibits growth of human pancreatic cancer cells.

    Science.gov (United States)

    Benavides, Maximo A; Bosland, Maarten C; da Silva, Cássio P; Gomes Sares, Claudia T; de Oliveira, Alana M Cerqueira; Kemp, Rafael; dos Reis, Rodolfo B; Martins, Vilma R; Sampaio, Suely V; Bland, Kirby I; Grizzle, William E; dos Santos, José S

    2014-02-01

    We have previously shown that L-methionine inhibits proliferation of breast, prostate, and colon cancer cells. This study extends these findings to BXPC-3 (mutated p53) and HPAC (wild-type p53) pancreatic cancer cells and explores the reversibility of these effects. Cells were exposed to L-methionine (5 mg/ml) for 7 days or for 3 days, followed by 4 days of culture without L-methionine (recovery). Cell proliferation, apoptosis, and cell cycle effects were assessed by flow cytometry after staining for Ki-67 or annexin V/propidium iodide. Cell proliferation was reduced by 31-35% after 7 days of methionine exposure; the effect persisted in BXPC-3 and HPAC cells after 4 days of recovery. Methionine increased apoptosis by 40-75% in HPAC cells, but not in BXPC-3 cells. Continuous exposure to methionine caused accumulation of BXPC-3 cells in the S phase and HPAC cells in both the G0/G1 and S phases; however, after 4 days of recovery, these effects disappeared. In conclusion, L-methionine inhibits proliferation and interferes with the cell cycle of BXPC-3 and HPAC pancreatic cancer cells; the effects on apoptosis remarkably persisted after methionine withdrawal. Apoptosis was induced only in BXPC-3 cells. Some of the differences in the effects of methionine between cell lines may be related to disparate p53 status. These findings warrant further studies on the potential therapeutic benefit of L-methionine against pancreatic cancer.

  12. The demonstration of extension of high-grade glioma beyond magnetic resonance imaging defined edema by the use of 11 C-methionine positron emission tomography

    Directory of Open Access Journals (Sweden)

    Sridhar P Susheela

    2013-01-01

    Full Text Available The use of magnetic resonance imaging (MRI is the current standard for the delineation of target volumes for high-grade gliomas (HGG. While the peritumoral edema as per T2-weighted (T2W imaging is utilized as basis to delineate the initial borders of the clinical target volume (CTV, those areas enhancing on T1-weighted (T1W images with gadolinium contrast (T1-Gd are considered for treatment with further boost. However, recent data has emerged concerning the use of positron emission tomography (PET with 11 C-methionine, which seemingly provides additional information beyond MRI. We present the case of a gentleman with an inoperable HGG which was imaged with 11 C-methionine-PET ( 11 C-MET-PET/CT as well as MRI as part of the radiotherapy treatment planning (RTP process. The differences noted between the MRI and the PET defined volumes are presented. This being a patient who was not operated, the potentially confounding issue of surgery-induced PET-avidity is absent.

  13. Methionine restriction and life-span control.

    Science.gov (United States)

    Lee, Byung Cheon; Kaya, Alaattin; Gladyshev, Vadim N

    2016-01-01

    Dietary restriction (DR) without malnutrition is associated with longevity in various organisms. However, it has also been shown that reduced calorie intake is often ineffective in extending life span. Selecting optimal dietary regimens for DR studies is complicated, as the same regimen may lead to different outcomes depending on genotype and environmental factors. Recent studies suggested that interventions such as moderate protein restriction with or without adequate nutrition (e.g., particular amino acids or carbohydrates) may have additional beneficial effects mediated by certain metabolic and hormonal factors implicated in the biology of aging, regardless of total calorie intake. In particular, it was shown that restriction of a single amino acid, methionine, can mimic the effects of DR and extend life span in various model organisms. We discuss the beneficial effects of a methionine-restricted diet, the molecular pathways involved, and the use of this regimen in longevity interventions.

  14. Design, Synthesis, and Evaluation of a Low-Molecular-Weight (11)C-Labeled Tetrazine for Pretargeted PET Imaging Applying Bioorthogonal in Vivo Click Chemistry.

    Science.gov (United States)

    Denk, Christoph; Svatunek, Dennis; Mairinger, Severin; Stanek, Johann; Filip, Thomas; Matscheko, Dominik; Kuntner, Claudia; Wanek, Thomas; Mikula, Hannes

    2016-07-20

    A low-molecular-weight tetrazine labeled with the short-lived positron emitter carbon-11 was developed as a bioorthogonal PET probe for pretargeted imaging. A method for efficient and fast synthesis of this imaging agent is presented using radiolabeling of a readily available precursor. High reactivity with trans-cyclooctenes was observed and in vivo investigations including PET/MR scanning showed homogeneous biodistribution, good metabolic stability, and rapid excretion in naive mice. These properties are key to the success of bioorthogonal (11)C-PET imaging, which has been shown in a simple pretargeting experiment using TCO-modified mesoporous silica nanoparticles. Overall, this (11)C-labeled tetrazine represents a highly versatile and advantageous chemical tool for bioorthogonal PET imaging and enables pretargeting approaches using carbon-11 for the first time. PMID:27308894

  15. Pet Problems at Home: Pet Problems in the Community.

    Science.gov (United States)

    Soltow, Willow

    1984-01-01

    Discusses problems of pets in the community, examining the community's role related to disruptive pets and pet overpopulation. Also discusses pet problems at home, offering advice on selecting a pet, meeting a pet's needs, and disciplining pets. Includes a list of books, films/filmstrips, teaching materials, and various instructional strategies.…

  16. Non-FDG PET in the practice of oncology

    Directory of Open Access Journals (Sweden)

    P Caroli

    2010-01-01

    Full Text Available Fluoro-2-deoxy-d-glucose-positron emission tomography (FDG-PET is utilized in more than 90% of cancers in staging, re-staging, assessing therapy response and during the follow-up. However, not all tumors show significant increase of metabolic activity on FDG-PET imaging. This is particularly true for prostate cancer, neuroendocrine tumors and hepatic tumors. In this review we have considered those already used for clinical applications such as 11C- and 18F-Choline, 11C-Methionine and 18F-FET, 18F-DOPA, 68Ga-DOTA-somatostatine analogues, 11C-Acetate and 18F-FLT. Choline presents a high affinity for malignant prostate tissue, even if low grade. Choline can be labeled with either 11C or 18F, the former being the preference due to lower urinary excretion and patients exposure. The latter is more useful for possible distribution to centers lacking in on-site cyclotron. Methionine is needed for protein synthesis and tumor cells require an external supply of methionine. These tracers have primarily been used for imaging of CNS neoplasms. The most appropriate indication is when conventional imaging procedures do not distinguish between edema, fibrosis or necrosis and disease relapse. In addition, the uptake of 11C-Methionine is proportional to the tumor grade and, therefore, the maximum small unilamellar vesicles (SUV inside the brain mass before therapy is somehow considered a prognostic value. Neuroendocrine tumors (carcinoids, pheocromocytoma, neuroblastoma, medullary thyroid cancer, microcytoma, carotid glomus tumors, and melanoma demonstrate an increased activity of L-DOPA decarboxylase, and hence they show a high uptake of 18FDOPA. For the study of NETs, 68Ga-DOTA-TOC/DOTA-NOC has been introduced as PET tracer. This compound for PET imaging has a high affinity for sst2 and sst5 and has been used in the detection of NETs in preliminary studies; 68Ga-DOTA-NOC PET is useful before metabolic radiotherapy in order to evaluate the biodistribution of the

  17. Methionine restriction beyond life-span extension.

    Science.gov (United States)

    Ables, Gene P; Hens, Julie R; Nichenametla, Sailendra N

    2016-01-01

    Dietary methionine restriction (MR) extends life span across species via various intracellular regulatory mechanisms. In rodents, MR induces resistance against adiposity, improves hepatic glucose metabolism, preserves cardiac function, and reduces body size, all of which can affect the onset of age-related diseases. Recent studies have shown that MR-affected biomarkers, such as fibroblast growth factor 21, adiponectin, leptin, cystathionine β synthase, and insulin-like growth factor 1, can potentially alter physiology. The beneficial effects of MR could be explained in part by its ability to reduce mitochondrial oxidative stress. Studies have revealed that MR can reduce reactive oxygen species that damage cells and promote cancer progression. It has been demonstrated that either MR or the targeting of specific genes in the methionine cycle could induce cell apoptosis while decreasing proliferation in several cancer models. The complete mechanism underlying the actions of MR on the cell cycle during cancer has not been fully elucidated. Epigenetic mechanisms, such as methylation and noncoding RNAs, are also possible downstream effectors of MR; future studies should help to elucidate some of these mechanisms. Despite evidence that changes in dietary methionine can affect epigenetics, it remains unknown whether epigenetics is a mechanism in MR. This review summarizes research on MR and its involvement in metabolism, cancer, and epigenetics.

  18. A Study on Pet Owners' Intention to Purchase Pet Insurance

    OpenAIRE

    Chiehwei Hung; Yen-Shan Chuang

    2014-01-01

    This study investigates the impacts of consumers¡¦ characteristics, pet feeding habits, pet spending and insurance conditions of pet owners on the intention to purchase a pet insurance policy. Our results reveal that family income, average monthly spending on pets, and experience of purchasing medical insurance are the significant determinants of a pet owner¡¦s intention to purchase pet insurance. Pet owners who have higher family income, higher pet spending, and who have previously purchased...

  19. SU-E-J-144: Low Activity Studies of Carbon 11 Activation Via GATE Monte Carlo

    International Nuclear Information System (INIS)

    Purpose: To investigate the behavior of a Monte Carlo simulation code with low levels of activity (∼1,000Bq). Such activity levels are expected from phantoms and patients activated via a proton therapy beam. Methods: Three different ranges for a therapeutic proton radiation beam were examined in a Monte Carlo simulation code: 13.5, 17.0 and 21.0cm. For each range, the decay of an equivalent length11C source and additional sources of length plus or minus one cm was studied in a benchmark PET simulation for activities of 1000, 2000 and 3000Bq. The ranges were chosen to coincide with a previous activation study, and the activities were chosen to coincide with the approximate level of isotope creation expected in a phantom or patient irradiated by a therapeutic proton beam. The GATE 7.0 simulation was completed on a cluster node, running Scientific Linux Carbon 6 (Red Hat©). The resulting Monte Carlo data were investigated with the ROOT (CERN) analysis tool. The half-life of11C was extracted via a histogram fit to the number of simulated PET events vs. time. Results: The average slope of the deviation of the extracted carbon half life from the expected/nominal value vs. activity showed a generally positive value. This was unexpected, as the deviation should, in principal, decrease with increased activity and lower statistical uncertainty. Conclusion: For activity levels on the order of 1,000Bq, the behavior of a benchmark PET test was somewhat unexpected. It is important to be aware of the limitations of low activity PET images, and low activity Monte Carlo simulations. This work was funded in part by the Philips corporation

  20. (18)F-FET-PET in Primary Hyperparathyroidism

    DEFF Research Database (Denmark)

    Krakauer, Martin; Kjaer, Andreas; Bennedbæk, Finn N

    2016-01-01

    Preoperative localisation of the diseased parathyroid gland(s) in primary hyperparathyroidism (PHP) is a prerequisite for subsequent minimally invasive surgery. Recently, as alternatives to conventional sestamibi parathyroid scintigraphy, the (11)C-based positron emission tomography (PET) tracers...... methionine and choline have shown promise for this purpose. We evaluated the feasibility of using the (18)F-based PET tracer fluoroethyl-l-tyrosine (FET), as the longer half-life of (18)F makes it logistically more favourable. As a proof-of-concept study, we included two patients with PHP in which dual...... under study was achieved approximately 30 min after the injection of the tracer and was 1.5 and 1.7, respectively. This ratio was too small to allow for confident visualisation of the adenomas. FET PET/CT seems not feasible as a preoperative imaging modality in PHP....

  1. N-Terminal methionine processing by the zinc-activated Plasmodium falciparum methionine aminopeptidase 1b.

    Science.gov (United States)

    Calcagno, Sarah; Klein, Christian D

    2016-08-01

    The methionine aminopeptidase 1b from Plasmodium falciparum (PfMetAP 1b) was cloned, expressed in Escherichia coli and characterized. Surprisingly, and in contrast to other methionine aminopeptidases (MetAPs) that require heavy-metal cofactors such as cobalt, the enzyme is reliably activated by zinc ions. Immobilization of the enzyme is possible by His-tag metal chelation to iminodiacetic acid-agarose and by covalent binding to chloroacetamido-hexyl-agarose. The covalently immobilized enzyme shows long-term stability, allowing a continuous, heterogenous processing of N-terminal methionines, for example, in recombinant proteins. Activation by zinc, instead of cobalt as for other MetAPs, avoids the introduction of heavy metals with toxicological liabilities and oxidative potential into biotechnological processes. The PfMetAP 1b therefore represents a useful tool for the enzymatic, posttranslational processing of recombinant proteins. PMID:27023914

  2. Bacterial variations on the methionine salvage pathway

    Directory of Open Access Journals (Sweden)

    Haas Dieter

    2004-03-01

    Full Text Available Abstract Background The thiomethyl group of S-adenosylmethionine is often recycled as methionine from methylthioadenosine. The corresponding pathway has been unravelled in Bacillus subtilis. However methylthioadenosine is subjected to alternative degradative pathways depending on the organism. Results This work uses genome in silico analysis to propose methionine salvage pathways for Klebsiella pneumoniae, Leptospira interrogans, Thermoanaerobacter tengcongensis and Xylella fastidiosa. Experiments performed with mutants of B. subtilis and Pseudomonas aeruginosa substantiate the hypotheses proposed. The enzymes that catalyze the reactions are recruited from a variety of origins. The first, ubiquitous, enzyme of the pathway, MtnA (methylthioribose-1-phosphate isomerase, belongs to a family of proteins related to eukaryotic intiation factor 2B alpha. mtnB codes for a methylthioribulose-1-phosphate dehydratase. Two reactions follow, that of an enolase and that of a phosphatase. While in B. subtilis this is performed by two distinct polypeptides, in the other organisms analyzed here an enolase-phosphatase yields 1,2-dihydroxy-3-keto-5-methylthiopentene. In the presence of dioxygen an aci-reductone dioxygenase yields the immediate precursor of methionine, ketomethylthiobutyrate. Under some conditions this enzyme produces carbon monoxide in B. subtilis, suggesting a route for a new gaseous mediator in bacteria. Ketomethylthiobutyrate is finally transaminated by an aminotransferase that exists usually as a broad specificity enzyme (often able to transaminate aromatic aminoacid keto-acid precursors or histidinol-phosphate. Conclusion A functional methionine salvage pathway was experimentally demonstrated, for the first time, in P. aeruginosa. Apparently, methionine salvage pathways are frequent in Bacteria (and in Eukarya, with recruitment of different polypeptides to perform the needed reactions (an ancestor of a translation initiation factor and Ru

  3. PET studies of stroke

    International Nuclear Information System (INIS)

    PET already has been helpful in ischemic stroke disease. It has given us new data on physiological events occurring after a stroke; PET indices of blood flow and metabolism have provided the basis for staging the severity of tissue injury and predicting outcome, and PET has shown alterations in tissue function in response to therapy. Experience with PET in hemorrhagic disease is more limited, but initial results suggest a useful role for PET in the evaluation of nontraumatic intracranial hemorrhage as well [Ackerman et al., 1983a]. This brief review discusses general problems in the study of stroke disease using PET and then the contribution of PET to the stroke field

  4. A Methionine Residue Promotes Hyperoxidation of the Catalytic Cysteine of Mouse Methionine Sulfoxide Reductase A.

    Science.gov (United States)

    Kim, Geumsoo; Levine, Rodney L

    2016-06-28

    Methionine sulfoxide reductase A (msrA) reduces methionine sulfoxide in proteins back to methionine. Its catalytic cysteine (Cys72-SH) has a low pKa that facilitates oxidation by methionine sulfoxide to cysteine sulfenic acid. If the catalytic cycle proceeds efficiently, the sulfenic acid is reduced back to cysteine at the expense of thioredoxin. However, the sulfenic acid is vulnerable to "irreversible" oxidation to cysteine sulfinic acid that inactivates msrA (hyperoxidation). We observed that human msrA is resistant to hyperoxidation while mouse msrA is readily hyperoxidized by micromolar concentrations of hydrogen peroxide. We investigated the basis of this difference in susceptibility to hyperoxidation and established that it is controlled by the presence or absence of a Met residue in the carboxyl-terminal domain of the enzyme, Met229. This residue is Val in human msrA, and when it was mutated to Met, human msrA became sensitive to hyperoxidation. Conversely, mouse msrA was rendered insensitive to hyperoxidation when Met229 was mutated to Val or one of five other residues. Positioning of the methionine at residue 229 is not critical, as hyperoxidation occurred as long as the methionine was located within the group of 14 carboxyl-terminal residues. The carboxyl domain of msrA is known to be flexible and to have access to the active site, and Met residues are known to form stable, noncovalent bonds with aromatic residues through interaction of the sulfur atom with the aromatic ring. We propose that Met229 forms such a bond with Trp74 at the active site, preventing formation of a protective sulfenylamide with Cys72 sulfenic acid. As a consequence, the sulfenic acid is available for facile, irreversible oxidation to cysteine sulfinic acid. PMID:27259041

  5. Comparison of methionine sources around requirement levels using a methionine efficacy method in 0 to 28 day old broilers.

    Science.gov (United States)

    Agostini, P S; Dalibard, P; Mercier, Y; Van der Aar, P; Van der Klis, J D

    2016-03-01

    The addition of methionine in the poultry feed industry is still facing the relative efficacy dilemma between DL-methionine (DLM) and hydroxy-methionine (HMTBA). The aim of this study was to compare the effect of dietary DLM and HMTBA on broiler performance at different levels of total sulfur amino acids (TSAA). The treatments consisted of a basal diet without methionine addition, and 4 increasing methionine doses for both sources resulting in TSAA/Lysine ratios from 0.62 to 0.73 in the starter phase and 0.59 to 0.82 in the grower phase. The comparison of product performance was performed by three-way ANOVA analysis and by methionine efficacy calculation as an alternative method of comparison. Growth results obtained during the starter phase with the different methionine supplementations did not show significant growth responses to TSAA levels, indicating a lower methionine requirement in the starter phase than currently assumed. However, a significant methionine dose effect was obtained for the period 10 to 28 day of age and for the entire growth period of 0 to 28 day of age. Excepting a significant gender effect, the statistical analysis did not allow for the discrimination of methionine sources, and no interaction between source and dose level was observed up to 28 days of age. A significant interaction between source and dose level was observed for methionine efficacy for the grower phase, and the total growth period showed better HMTBA efficacy at higher TSAA value. The exponential model fitted to each methionine source for body weight response depending on methionine intake or for feed conversion ratio (FCR) depending on methionine doses did not allow the methionine sources to be distinguished. Altogether, these results conclude that methionine sources lead to similar performances response when compared at TSAA values around the broiler requirement level. These results also showed that at TSAA values above requirement, HMTBA had a better methionine efficacy

  6. False positive localisation of C-11 methionine in a colloid nodule

    International Nuclear Information System (INIS)

    A 45-year-old female diagnosed with carcinoma of the left breast on histopathological examination underwent both 18F-flourodeoxyglucose (FDG) and 11C-methionine (MET) positron emission tomography/computed tomography (PET/CT) as part of a protocol comparing the utility of these tracers for predicting a response to neoadjuvant chemotherapy in breast carcinoma. Abnormal FDG and MET accumulation was noted in the left breast primary, left axillary lymph nodes, and also in a well-defined nodule present in the left lobe of the thyroid gland. Keeping in mind the possibility of thyroid neoplasm/metastasis, the patient was referred for fine needle aspiration cytology (FNAC) from the thyroid nodule that revealed features of a simple colloid nodule. Focal thyroid lesions incidentally found on 18F-FDG PET/CT have a high risk of thyroid malignancy. Non-specific accumulation of FDG in thyroid adenomas is also known. This case highlights a potential cause for false positive on C-11 MET PET/CT in colloid adenomas, which should be kept in mind while using this tracer for oncological indications

  7. A 4-week toxicity study of methionine in male rats.

    Science.gov (United States)

    Chin, Keigi; Toue, Sakino; Kawamata, Yasuko; Watanabe, Akiko; Miwa, Tadashi; Smriga, Miro; Sakai, Ryosei

    2015-01-01

    To examine 4-week toxicity of l-methionine (methionine), 5-week-old Fisher strain male rats were fed on diets containing 0, 0.1, 0.3, 0.9, 2.7 (w/w) of added methionine. Although no deaths were recorded, the highest dose of methionine (2.7% [w/w] of diet) reduced food intake and significantly suppressed growth rate. Growth suppression was characterized by an increase in hemolysis, splenic, and hepatic accumulation of hemosiderin, hemolytic anemia, and promotion of hematopoiesis. Other changes observed in the highest methionine intake group were a decrease in white blood cell count, thymus atrophy, and histological abnormalities in the adrenal gland and testis. Small, but significant, growth suppression, accompanied by some minor changes in plasma biochemical parameters, was also seen in rats fed on a test diet containing 0.9% (w/w) of additional methionine. Thus, no-observed-adverse-effect-level (NOAEL) and lowest-observed-adverse-effect level (LOAEL) of diet-added methionine were determined at 0.3% and 0.9% (w/w), corresponding to 236 and 705 mg/kg/d body weight, respectively. Since the basal diet contained protein-bound methionine at 0.5% (w/w), NOAEL and LOAEL of total dietary methionine were estimated at 0.8% and 1.4% (w/w) of diet.

  8. Regulation of thrombosis and vascular function by protein methionine oxidation.

    Science.gov (United States)

    Gu, Sean X; Stevens, Jeff W; Lentz, Steven R

    2015-06-18

    Redox biology is fundamental to both normal cellular homeostasis and pathological states associated with excessive oxidative stress. Reactive oxygen species function not only as signaling molecules but also as redox regulators of protein function. In the vascular system, redox reactions help regulate key physiologic responses such as cell adhesion, vasoconstriction, platelet aggregation, angiogenesis, inflammatory gene expression, and apoptosis. During pathologic states, altered redox balance can cause vascular cell dysfunction and affect the equilibrium between procoagulant and anticoagulant systems, contributing to thrombotic vascular disease. This review focuses on the emerging role of a specific reversible redox reaction, protein methionine oxidation, in vascular disease and thrombosis. A growing number of cardiovascular and hemostatic proteins are recognized to undergo reversible methionine oxidation, in which methionine residues are posttranslationally oxidized to methionine sulfoxide. Protein methionine oxidation can be reversed by the action of stereospecific enzymes known as methionine sulfoxide reductases. Calcium/calmodulin-dependent protein kinase II is a prototypical methionine redox sensor that responds to changes in the intracellular redox state via reversible oxidation of tandem methionine residues in its regulatory domain. Several other proteins with oxidation-sensitive methionine residues, including apolipoprotein A-I, thrombomodulin, and von Willebrand factor, may contribute to vascular disease and thrombosis.

  9. Radiation protection problems in a laboratory for the labelling of molecules with carbon-11

    International Nuclear Information System (INIS)

    This paper shows that the qualities of carbon-11, especially its short half-life, which suit it so well for the labelling of radiopharmaceuticals prove to be a great handicap in the preparation of these substances. The operator has to make a fresh preparation for each examination and start with strong radioactivities (200 to 500 mCi) in order to obtain an adequate injected activity at the end of the process, the absorbed dose averaging 1.5 man-rem per manipulation at the fingertips. The development of an automatic preparation method involving as little manual interference as possible has halved the collective dose for twice the dose handled. The labelling of molecules used for diagnosis is now considered to take place under satisfactory radioprotection conditions. The fingertip irradiations are analysed in the light of CIPR recommendations, while regretting that in publication 26 this problem of partial external irradiation of the skin is not dealt with as clearly and precisely as before

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

    OpenAIRE

    Marc Pretze; Constantin Mamat; Philipp Große-Gehling

    2011-01-01

    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 radionuc...

  11. Effects of polymorphisms of methionine synthase and methionine synthase reductase on total plasma homocysteine in the NHLBI Family Heart Study.

    Science.gov (United States)

    Jacques, Paul F; Bostom, Andrew G; Selhub, Jacob; Rich, Sharron; Ellison, R Curtis; Eckfeldt, John H; Gravel, Roy A; Rozen, Rima

    2003-01-01

    The metabolism of homocysteine requires contributions of several enzymes and vitamin cofactors. Earlier studies identified a common polymorphism of methylenetetrahydrofolate reductase that was associated with mild hyperhomocysteinemia. Common variants of two other enzymes involved in homocysteine metabolism, methionine synthase and methionine synthase reductase, have also been identified. Methionine synthase catalyzes the remethylation of homocysteine to form methionine and methionine synthase reductase is required for the reductive activation of the cobalamin-dependent methionine synthase. The methionine synthase gene (MTR) mutation is an A to G substitution, 2756A-->G, which converts an aspartate to a glycine codon. The methionine synthase reductase gene (MTRR) mutation is an A to G substitution, 66A-->G, that converts an isoleucine to a methionine residue. To determine if these polymorphisms were associated with mild hyperhomocysteinemia, we investigated subjects from two of the NHLBI Family Heart Study field centers, Framingham and Utah. Total plasma homocysteine concentrations were determined after an overnight fast and after a 4-h methionine load test. MTR and MTRR genotype data were available for 677 and 562 subjects, respectively. The geometric mean fasting homocysteine was unrelated to the MTR or MTRR genotype categories (AA, AG, GG). After a methionine load, a weak positive association was observed between change in homocysteine after a methionine load and the number of mutant MTR alleles (P-trend=0.04), but this association was not statistically significant according to the overall F-statistic (P=0.12). There was no significant interaction between MTR and MTRR genotype or between these genotypes and any of the vitamins with respect to homocysteine concentrations. This study provides no evidence that these common MTR and MTRR mutations are associated with alterations in plasma homocysteine. PMID:12482550

  12. L-methionine degradation potentialities of cheese-ripening microorganisms.

    Science.gov (United States)

    Bonnarme, P; Lapadatescu, C; Yvon, M; Spinnler, H E

    2001-11-01

    Volatile sulphur compounds are major flavouring compounds in many traditional fermented foods including cheeses. These compounds are products of the catabolism of L-methionine by cheese-ripening microorganisms. The diversity of L-methionine degradation by such microorganisms, however, remains to be characterized. The objective of this work was to compare the capacities to produce volatile sulphur compounds by five yeasts, Geotrichum candidum, Yarrowia lipolytica, Kluyveromyces lactis, Debaryomyces hansenii, Saccharomyces cerevisiae and five bacteria, Brevibacterium linens, Corynebacterium glutamicum, Arthrobacter sp., Micrococcus lutens and Staphylococcus equorum of technological interest for cheese-ripening. The ability of whole cells of these microorganisms to generate volatile sulphur compounds from L-methionine was compared. The microorganisms produced a wide spectrum of sulphur compounds including methanethiol, dimethylsulfide, dimethyldisulfide, dimethyltrisulfide and also S-methylthioesters, which varied in amount and type according to strain. Most of the yeasts produced methanethiol, dimethylsulfide, dimethyldisulfide and dimethyltrisulfide but did not produce S-methylthioesters, apart from G. candidum that produced S-methyl thioacetate. Bacteria, especially Arth. sp. and Brevi. linens, produced the highest amounts and the greatest variety of volatile sulphur compounds includling methanethiol, sulfides and S-methylthioesters, e.g. S-methyl thioacetate, S-methyl thiobutyrate, S-methyl thiopropionate and S-methyl thioisovalerate. Cell-free extracts of all the yeasts and bacteria were examined for the activity of enzymes possibly involved in L-methionine catabolism, i.e. L-methionine demethiolase, L-methionine aminotransferase and L-methionine deaminase. They all possessed L-methionine demethiolase activity, while some (K. lactis, Deb. hansenii, Arth. sp., Staph. equorum) were deficient in L-methionine aminotransferase, and none produced L-methionine deaminase

  13. Cyclotron, positrons and PET [positron emission tomography]. An overview

    International Nuclear Information System (INIS)

    PET (positron emission tomography) is a powerful new scientific tool which is capable of revealing biochemical transformations while they are occurring in the brain and other organs in the living human body. The application of PET to problems in biology and medicine is dominated by the short half-life of the isotopes used to prepare the radiotracers. The most commonly used positron emitting isotopes are carbon-11, fluorine-18, nitrogen-13, and oxygen-15 which have half-lives of 20.4, 110, 10 and 2 minutes, respectively. Their incorporation into radiotracers having diverse chemical structures and biochemical specificities has allowed the study of blood flow, sugar metabolism, oxygen metabolism, neurotransmission, enzyme activity and binding sites for therapeutic drugs and substances of abuse. PET research is most commonly carried out at a Cyclotron-PET Center (cyclotron, positron emission tomography, chemistry laboratory) where the short-lived isotopes can be produced and used efficiently. The number of Cyclotron-PET Centers has grown from 4 in 1976 to several dozen in 1988 and the number is expected to double in the next five years attesting to the vitality of the field and the current and anticipated contributions to research in biology and medicine

  14. Dependence on exogenous methionine of rat sarcoma and murine leukemia cells in culture.

    Science.gov (United States)

    Koziorowska, J; Pieńkowska, K; Tautt, J

    1980-01-01

    A comparative study was performed on methionine auxotrophy of rat sarcoma and murine leukemia cells taken directly from the organism and grown in culture in media lacking methionine or in which methionine was substituted by homocysteine. Methionine auxotrophy was observed in both kinds of cells. At low levels of methionine in the media containing homocysteine rat sarcoma cells showed an increase in growth. Addition of homocysteine to the media with low levels of methionine did not influence the survival of murine leukemia cells.

  15. Measurement of regional pulmonary function with carbon-11-labeled CO2 and CO

    International Nuclear Information System (INIS)

    Carbon dioxide and carbon monoxide labelled with carbon-11 have been produced in the remotecontrolled system for a large scale production of short lived radioactive substance with cyclotron in National Institute of Radiological Sciences. The single breath measurement with 11CO2 and 11CO, using inhalation system and a coincidence positron camera combined with an on-line computer system (TOSBAC 3400 Model 31) has been employed to evaluate regional pulmonary blood flow and diffusing capacity in three normal volunteers and seven patients with chronic obstructive pulmonary disease (COPD), old lung tuberculosis and benign tumor. Regional clearance rate constant (lambda) and distribution index (lambda i/lambda t) were calculated from monoexponential removal curves measured by external counting over the chest in supine position. This process was performed in a short period of breath-holding (10 - 20 sec.) after a single breath of these radioactive gases mixed with room air. These parameters were calculated for each lung fields divided into four zones (bilateral upper and lower lung region). In our method, the activity of the inspired mixture were 5 - 35 mCi/L and each value in lung fields, divided into four zones, can be measured with time interval for one second. While the clearance rate of 11CO2 seemed to be mainly limited by pulmonary blood flow, it was considered that the rate of 11CO were limited by not only the diffusing capacity but also the perfusion in each lung fields. In normal subjects, the distribution of regional clearance rate was showed approximately even for 11CO2 and 11CO. It was caused of the measurement in supine position. In contrast, the distribution of these parameter was showed uneven in patients with lung disease, particularly with COPD. (author)

  16. The use of FDG-PET to target tumors by radiotherapy

    Energy Technology Data Exchange (ETDEWEB)

    Lambin, Philippe [MAASTRO Clinic, Radiation Oncology, Maastricht (Netherlands); Lammering, Guido; Ruysscher, Dirk de; Baardwijk, Angela van; Baumert, Brigitta G.; Borger, Jacques; Lutgens, Ludy; Ende, Piet van den; Oellers, Michel

    2010-09-15

    Fluorodeoxyglucose positron emission tomography (FDG-PET) plays an increasingly important role in radiotherapy, beyond staging and selection of patients. Especially for non-small cell lung cancer, FDG-PET has, in the majority of the patients, led to the safe decrease of radiotherapy volumes, enabling radiation dose escalation and, experimentally, redistribution of radiation doses within the tumor. In limited-disease small cell lung cancer, the role of FDG-PET is emerging. For primary brain tumors, PET based on amino acid tracers is currently the best choice, including high-grade glioma. This is especially true for low-grade gliomas, where most data are available for the use of {sup 11}C-MET (methionine) in radiation treatment planning. For esophageal cancer, the main advantage of FDG-PET is the detection of otherwise unrecognized lymph node metastases. In Hodgkin's disease, FDG-PET is essential for involved-node irradiation and leads to decreased irradiation volumes while also decreasing geographic miss. FDG-PET's major role in the treatment of cervical cancer with radiation lies in the detection of para-aortic nodes that can be encompassed in radiation fields. Besides for staging purposes, FDG-PET is not recommended for routine radiotherapy delineation purposes. It should be emphasized that using PET is only safe when adhering to strictly standardized protocols. (orig.)

  17. High Methionine Diet Poses Cardiac Threat: A Molecular Insight.

    Science.gov (United States)

    Chaturvedi, Pankaj; Kamat, Pradip K; Kalani, Anuradha; Familtseva, Anastasia; Tyagi, Suresh C

    2016-07-01

    High methionine diet (HMD) for example red meat which includes lamb, beef, pork can pose cardiac threat and vascular dysfunction but the mechanisms are unclear. We hypothesize that a diet rich in methionine can malfunction the cardiovascular system in three ways: (1) by augmenting oxidative stress; (2) by inflammatory manifestations; and (3) by matrix/vascular remodeling. To test this hypothesis we used four groups of mice: (1) WT; (2) WT + methionine; (3) CBS(+/-) ; (4) CBS(+/-) +methionine. We observed high oxidative stress in mice fed with methionine which was even higher in CBS(+/-) and CBS(+/-) +methionine. Higher oxidative stress was indicated by high levels of SOD-1 in methionine fed mouse hearts whereas IL-1β, IL-6, TNFα, and TLR4 showed high inflammatory manifestations. The upregulated levels of eNOS/iNOS and upregulated levels of MMP2/MMP9 along with high collagen deposition indicated vascular and matrix remodeling in methionine fed mouse. We evaluated the cardiac function which was dysregulated in the mice fed with HMD. These mice had decreased ejection fraction and left ventricular dysfunction which subsequently leads to adverse cardiac remodeling. In conclusion, our study clearly shows that HMD poses a cardiac threat by increasing oxidative stress, inflammatory manifestations, matrix/vascular remodeling, and decreased cardiac function.

  18. Molecular flexibility and structural instabilities in crystalline L-methionine

    NARCIS (Netherlands)

    Fischer, Jennifer; Lima, Jose A.; Freire, Paulo T. C.; Melo, Francisco E. A.; Havenith, Remco W. A.; Mendes Filho, Josue; Broer, Ria; Eckert, Juergen; Bordallo, Heloisa N.

    2013-01-01

    We have investigated the dynamics in polycrystalline samples of L-methionine related to the structural transition at about 307 K by incoherent inelastic and quasielastic neutron scattering, X-ray powder diffraction as well as ab-initio calculations. L-Methionine is a sulfur amino acid which can be c

  19. S-adenosyl-L-methionine for alcoholic liver diseases

    DEFF Research Database (Denmark)

    Rambaldi, A; Gluud, C

    2006-01-01

    Alcohol is a major cause of liver disease and disrupts methionine and oxidative balances. S-adenosyl-L-methionine (SAMe) acts as a methyl donor for methylation reactions and participates in the synthesis of glutathione, the main cellular antioxidant. Randomised clinical trials have addressed...... the question whether SAMe may benefit patients with alcoholic liver diseases....

  20. Non-invasive estimation of myocardial efficiency using positron emission tomography and carbon-11 acetate--comparison between the normal and failing human heart.

    Science.gov (United States)

    Bengel, F M; Permanetter, B; Ungerer, M; Nekolla, S; Schwaiger, M

    2000-03-01

    The clearance kinetics of carbon-11 acetate, assessed by positron emission tomography (PET), can be combined with measurements of ventricular function for non-invasive estimation of myocardial oxygen consumption and efficiency. In the present study, this approach was applied to gain further insights into alterations in the failing heart by comparison with results obtained in normals. We studied ten patients with idiopathic dilated cardiomyopathy (DCM) and 11 healthy normals by dynamic PET with 11C-acetate and either tomographic radionuclide ventriculography or cine magnetic resonance imaging. A "stroke work index" (SWI) was calculated by: SWI = systolic blood pressure x stroke volume/body surface area. To estimate myocardial efficiency, a "work-metabolic index" (WMI) was then obtained as follows: WMI = SWI x heart rate/k(mono), where k(mono) is the washout constant for 11C-acetate derived from monoexponential fitting. In DCM patients, left ventricular ejection fraction was 19%+/-10% and end-diastolic volume was 92+/-28 ml/m2 (vs 64%+/-7% and 55+/-8 ml/m2 in normals, PSWI (1674+/-761 vs 4736+/-895 mmHg x ml/m2; P<0.001) and the WMI as an estimate of efficiency (2.98+/-1.30 vs 6.20+/-2.25 x 10(6) mmHg x ml/m2; P<0.001) were lower in DCM patients, too. Overall, the WMI correlated positively with ejection parameters (r=0.73, P<0.001 for ejection fraction; r=0.93, P<0.001 for stroke volume), and inversely with systemic vascular resistance (r=-0.77; P<0.001). There was a weak positive correlation between WMI and end-diastolic volume in normals (r=0.45; P=0.17), while in DCM patients, a non-significant negative correlation coefficient (r=-0.21; P=0.57) was obtained. In conclusion non-invasive estimates of oxygen consumption and efficiency in the failing heart were reduced compared with those in normals. Estimates of efficiency increased with increasing contractile performance, and decreased with increasing ventricular afterload. In contrast to normals, the failing heart

  1. Heart PET scan

    Science.gov (United States)

    ... nuclear medicine scan; Heart positron emission tomography; Myocardial PET scan ... A PET scan requires a small amount of radioactive material (tracer). This tracer is given through a vein (IV), ...

  2. Clinical PET application

    Energy Technology Data Exchange (ETDEWEB)

    Lim, Sang-Moo; Hong, S. W.; Choi, C. W.; Yang, S. D.; Choi, J. S.; Kweon, O. J. et al. [Korea Cancer Center Hospital, Seoul (Korea)

    2000-12-01

    PET gives various metabolic images, and is very important, new diagnostic modality in clinical oncology. In Korea Cancer Center Hospital, PET is installed as a research tool of long-mid-term atomic research project. For the efficient use of PET for clinical and research projects, income from the patients should be managed to get the raw material, equipment, manpower, and also for the clinical PET research. 1. Support the clinical application of PET in oncology. 2. Budgetary management of income, costs for raw material, equipment, manpower, and the clinical PET research project. In this year, 1,327 cases of PET images were obtained, which resulted total income of 829,770,000won. Increased demand for {sup 18}FDG in and outside KCCH need more than 2 times production of {sup 18} in a day. Manpower should be added for the second PET operation and RI production. 10 figs., 4 tabs. (Author)

  3. PET and PET-CT. State of the art and future prospects; PET e PET- TC. Stato dell'arte e prospettive future

    Energy Technology Data Exchange (ETDEWEB)

    Fanti, Stefano; Franchi, Roberto [Policlinico S. Orsola-Malpighi, Bologna (Italy). U.O. di medicina legale; Battista, Giuseppe; Monetti, Nino; Canini, Romeo [Bologna Univ., Bologna (Italy). Dipartimento clinico di scienze radiologiche e istocitopatologiche

    2005-07-15

    Fluoro-deoxyglucose positron emission tomography (FDG PET) enables the in vivo study of tissue metabolism, and thus is able to identify malignant tumours as hypermetabolic lesions by an increase in tracer uptake. Many papers have demonstrated both the relevant impact of FDG PET on staging of many cancers and the superior accuracy of the technique compared with conventional diagnostic methods for pre-treatment evaluation, therapy response evaluation and relapse identification. In particular PET was found useful in identifying lymph nodal and metastatic spread. thus altering patient management in more than 30% of cases. PET images, however, provide limited anatomical data, which in regions such as the head and neck, mediastinum and pelvic cavity is a significant drawback. The exact localization of lesions may also be difficult in some cases, on the basis of PET images alone. The introduction of combined PET-computed tomography (PET-CT) scanners enables the almost simultaneous acquisition of transmission and emission images, thus obtaining optimal fusion images in a very short time. PET-CT fusion images enable lesions to be located, reducing false positive studies and increasing accuracy; the overall duration of examination may also be reduced. On the basis of both literature data and our experience we established the clinical indications when PET-CT may be particularly useful, in comparison with PET alone. It should also be underlined that the use of PET-CT is almost mandatory for new traces such as C-choline and C-methionine; these new tracers may be applied for studying tumours not assessable with FDG, such as prostate cancer. In conclusion PET-CT is at present the most advanced method for metabolic imaging, and is capable of precisely localizing and assessing tumours; fusion images reduce false positive and inconclusive studies, thus increasing diagnostic accuracy. [Italian] La PET con FDG F-18 ha consentito di studiare il metabolismo dei tessuti in vivo e di

  4. Development of a modular system for the synthesis of PET [{sup 11}C]labelled radiopharmaceuticals

    Energy Technology Data Exchange (ETDEWEB)

    Boschi, Stefano [PET Radiopharmacy, Nuclear Medicine, Azienda Ospedaliero Universitaria di Bologna, Policlinico S.Orsola-Malpighi, Via Massarenti 9, 40138 Bologna (Italy)], E-mail: stefano.boschi@aosp.bo.it; Lodi, Filippo [PET Radiopharmacy, Nuclear Medicine, Azienda Ospedaliero Universitaria di Bologna, Policlinico S.Orsola-Malpighi, Via Massarenti 9, 40138 Bologna (Italy); Cicoria, Gianfranco [Medical Physics, Azienda Ospedaliero Universitaria di Bologna, Policlinico S.Orsola-Malpighi (Italy); Raul Ledesma, Jorge [Fundacion Escuela de Medicina Nuclear, Mendoza (Argentina); Knopp, Roger [Eckert Ziegler-Eurotope, Berlin (Germany); Rizzello, Anna; Di Pierro, Donato; Trespidi, Silvia [PET Radiopharmacy, Nuclear Medicine, Azienda Ospedaliero Universitaria di Bologna, Policlinico S.Orsola-Malpighi, Via Massarenti 9, 40138 Bologna (Italy); Marengo, Mario [Medical Physics, Azienda Ospedaliero Universitaria di Bologna, Policlinico S.Orsola-Malpighi (Italy)

    2009-10-15

    [{sup 11}C]labelled radiopharmaceuticals as N-[{sup 11}C]methyl-choline ([{sup 11}C]choline), L-(S-methyl-[{sup 11}C])methionine ([{sup 11}C]methionine) and [{sup 11}C]acetate have gained increasing importance in clinical PET and for the routine production of these radiopharmaceuticals, simple and reliable modules are needed to produce clinically relevant radioactivity. On the other hand, flexible devices are needed not only for the routine synthesis but also for more complex applications as the development of new tracers. The aim of this work was the adaptation of an Eckert Ziegler modular system for easy routine synthesis of [{sup 11}C]choline, [{sup 11}C]methionine and [{sup 11}C]acetate using components that account for straightforward scaling up and upgrades.

  5. Protein-borne methionine residues as structural antioxidants in mitochondria.

    Science.gov (United States)

    Schindeldecker, Mario; Moosmann, Bernd

    2015-07-01

    Methionine is an oxidant-labile amino acid whose major oxidation products, methionine sulfoxides, can be readily repaired by various NADPH-dependent methionine sulfoxide reductases. Formally, the methionine oxidation-reduction circuit could act as a cellular antioxidant system, by providing a safe sink for oxidants that might cause much more damage if reacting otherwise. This concept is supported by focal experimental evidence; however, the global importance, scope and biochemical role of protein-borne methionine as an inbuilt macromolecular antioxidant have remained incompletely defined. In analyzing proteomic methionine usage on different levels of comparison, we find that protein methionine (i) is primarily an antioxidant of mitochondria, especially of the inner mitochondrial membrane, (ii) responds strongly to respiratory demands on an evolutionary timescale, (iii) acts locally, by selectively protecting its carrier protein, and (iv) might be utilized as a molecular predictor of aerobic metabolic rate in animals, to complement traditional markers like the presence of a respiratory pigment. Our data support the idea that proteins in need of a long lifespan or acting in dangerous environments may acquire massive structural alterations aimed at increasing their resistance to oxidation. Counterintuitively though, they sometimes do so by accumulating particularly labile rather than particularly stable building blocks, illustrating that the technical concept of cathodic protection is also employed by the animate nature.

  6. Excess dietary methionine does not affect fracture healing in mice

    Science.gov (United States)

    Holstein, Joerg H.; Schmalenbach, Julia; Herrmann, Markus; Ölkü, Ilona; Garcia, Patric; Histing, Tina; Herrmann, Wolfgang; Menger, Michael D.; Pohlemann, Tim; Claes, Lutz

    2012-01-01

    Summary Background An elevated serum concentration of homocysteine (hyperhomocysteinemia) has been shown to disturb fracture healing. As the essential amino acid, methionine, is a precursor of homocysteine, we aimed to investigate whether excess methionine intake affects bone repair. Material/Methods We analyzed bone repair in 2 groups of mice. One group was fed a methionine-rich diet (n=13), and the second group received an equicaloric control diet without methionine supplementation (n=12). Using a closed femoral fracture model, bone repair was analyzed by histomorphometry and biomechanical testing at 4 weeks after fracture. Blood was sampled to measure serum concentrations of homocysteine, the bone formation marker osteocalcin, and the bone resorption marker collagen I C-terminal crosslaps Results Serum concentrations of homocysteine were significantly higher in the methionine group than in the control group, while serum markers of bone turnover did not differ significantly between the 2 groups. Histomorphometry revealed no significant differences in size and tissue composition of the callus between animals fed the methionine-enriched diet and those receiving the control diet. Accordingly, animals of the 2 groups showed a comparable bending stiffness of the healing bones. Conclusions We conclude that excess methionine intake causes hyperhomocysteinemia, but does not affect fracture healing in mice. PMID:23197225

  7. Role of Methionine Adenosyltransferase Genes in Hepatocarcinogenesis

    International Nuclear Information System (INIS)

    Hepatocellular carcinoma (HCC) is the most common primary malignant tumor of the liver. Detection of HCC can be difficult, as most of the patients who develop this tumor have no symptoms other than those related to their longstanding liver disease. There is an urgent need to understand the molecular mechanisms that are responsible for the development of this disease so that appropriate therapies can be designed. Methionine adenosyltransferase (MAT) is an essential enzyme required for the biosynthesis of S-adenosylmethionine (AdoMet), an important methyl donor in the cell. Alterations in the expression of MAT genes and a decline in AdoMet biosynthesis are known to be associated with liver injury, cirrhosis and HCC. This review focuses on the role of MAT genes in HCC development and the scope for therapeutic strategies using these genes

  8. Role of Methionine Adenosyltransferase Genes in Hepatocarcinogenesis

    Directory of Open Access Journals (Sweden)

    Shelly C. Lu

    2011-03-01

    Full Text Available Hepatocellular carcinoma (HCC is the most common primary malignant tumor of the liver. Detection of HCC can be difficult, as most of the patients who develop this tumor have no symptoms other than those related to their longstanding liver disease. There is an urgent need to understand the molecular mechanisms that are responsible for the development of this disease so that appropriate therapies can be designed. Methionine adenosyltransferase (MAT is an essential enzyme required for the biosynthesis of S-adenosylmethionine (AdoMet, an important methyl donor in the cell. Alterations in the expression of MAT genes and a decline in AdoMet biosynthesis are known to be associated with liver injury, cirrhosis and HCC. This review focuses on the role of MAT genes in HCC development and the scope for therapeutic strategies using these genes.

  9. Biodistribution of the radionuclides (18)F-FDG, (11)C-methionine, (11)C-PK11195, and (68)Ga-citrate in domestic juvenile female pigs and morphological and molecular imaging of the tracers in hematogenously disseminated Staphylococcus aureus lesions

    DEFF Research Database (Denmark)

    Afzelius, Pia Maria Tullia; Nielsen, Ole L; Alstrup, Aage Ko;

    2016-01-01

    -FDG) positron emission tomography (PET) to PET with tracers that potentially could improve uncovering of infectious lesions in soft tissues. We chose (11)C-methionine, (11)C-PK11195, and (68)Ga-citrate as tracers and besides presenting their bio-distribution we validated their diagnostic utility in pigs...... with experimental bacterial infection. Four juvenile 14-15 weeks old female domestic pigs were scanned seven days after intra-arterial inoculation in the right femoral artery with a porcine strain of S. aureus using a sequential scanning protocol with (18)F-FDG, (11)C-methionine, (11)C-PK11195 and (68)Ga......-citrate. This was followed by necropsy of the pigs consisting of gross pathology, histopathology and microbial examination. The pigs primarily developed lesions in lungs and neck muscles. (18)F-FDG had higher infection to background ratios and accumulated in most infectious foci caused by S. aureus, while (11)C-methionine...

  10. The Hepatocarcinogenic Effect of Methionine and Choline Deficient Diets: an Adaptation to the Warburg Effect?

    OpenAIRE

    Mato, José M.; Lu, Shelly C

    2011-01-01

    Normal differentiated hepatocytes primarily metabolize methionine, via homocysteine synthesis, through the transsulfuration pathway. In addition to glutathione, this pathway produces α-ketobutyrate that is further metabolized in the mitochondria. It is only under low methionine conditions that differentiated hepatocytes predominantly regenerate methionine from homocysteine. In contrast, proliferating hepatocytes and liver cancer cells regenerate methionine from homocysteine regardless of the ...

  11. Interference by methionine on valine uptake in Acremonium chrysogenum.

    OpenAIRE

    Alonso, M J; Luengo, J M

    1987-01-01

    The incorporation of L-[U-14C]valine into delta-(L-alpha-aminoadipyl)-L-cysteinyl-D-valine (ACV), a direct biosynthetic precursor of penicillins and cephalosporins, was studied. When DL-methionine was added to Acremonium chrysogenum culture broths, no labeled ACV was found, while a large amount of radioactive ACV was detected when methionine was not present. DL-Norleucine, a nonsulfur analog of methionine, also inhibited the synthesis of radioactive ACV to some degree. This effect was due to ...

  12. l-Methionine inhibits growth of human pancreatic cancer cells

    OpenAIRE

    Benavides, Maximo A.; Bosland, Maarten C.; da Silva, Cássio P.; Sares, Claudia T. Gomes; de Oliveira, Alana M. Cerqueira; Kemp, Rafael; dos Reis, Rodolfo B.; VILMA R. MARTINS; Sampaio, Suely V; Bland, Kirby I; Grizzle, William E.; dos Santos, José S.

    2014-01-01

    We have previously shown that l-methionine inhibits proliferation of breast, prostate, and colon cancer cells. This study extends these findings to BXPC-3 (mutated p53) and HPAC (wild-type p53) pancreatic cancer cells and explores the reversibility of these effects. Cells were exposed to l-methionine (5 mg/ml) for 7 days or for 3 days, followed by 4 days of culture without l-methionine (recovery). Cell proliferation, apoptosis, and cell cycle effects were assessed by flow cytometry after stai...

  13. Production and application of synthetic precursors labeled with carbon-11 and fluorine-18

    Energy Technology Data Exchange (ETDEWEB)

    Ferrieri, R.A.

    2001-04-02

    It is evident from this chapter that there is enormous flexibility both in the selection of the nature of the radioisotope and ways to generate it, as well as in the selection of the labeling precursor to appropriately attach that radioisotope to some larger biomolecule of interest. The arsenal of radiolabeling precursors now available to the chemist is quite extensive, and without a doubt will continue to grow as chemists develop new ones. However, the upcoming years will perhaps reflect a greater effort in refining existing methods for preparing some of those precursors that are already available to us. For example, the use of solid-phase reactions to accomplish in a single step what would normally take several using conventional solvent-based reactions has already been shown to work in many occasions. The obvious advantage here is that processes become more amenable to system automation thus affording greater reliability in day-to-day operations. There are perhaps other technologies in science that have yet to be realized by the chemist in the PET laboratory that could provide a similar or even a greater benefit. One only needs to be open to new ideas, and imaginative enough to apply them to the problems at hand.

  14. Synthesis and initial evaluation of [{sup 11}C](R)-RWAY in monkey - a new, simply labeled antagonist radioligand for imaging brain 5-HT{sub 1A} receptors with PET

    Energy Technology Data Exchange (ETDEWEB)

    McCarron, Julie A.; Zoghbi, Sami S.; Shetty, H.U.; Ichise, Masanori; Yasuno, Fumihiko; Innis, Robert B.; Pike, Victor W. [National Institutes of Health, Molecular Imaging Branch, National Institute of Mental Health, Bethesda, MD (United States); Vermeulen, Eric S.; Wikstroem, Haakan V. [University of Groningen, Department of Medicinal Chemistry, University Center for Pharmacy, Groningen (Netherlands); Halldin, Christer [Karolinska Institutet, Department of Clinical Neuroscience, Psychiatry Section, Stockholm (Sweden)

    2007-10-15

    We aimed to fulfill a need for a radioligand that may be simply labeled with carbon-11 for effective positron emission tomography (PET) imaging of brain 5-HT{sub 1A} receptors. Racemic RWAY (2,3,4,5,6,7-hexahydro-1-[4-[1-[4-(2-methoxyphenyl)piperazinyl

  15. Vitamin-Dependent Methionine Metabolism and Alcoholic Liver Disease1

    Science.gov (United States)

    Halsted, Charles H.; Medici, Valentina

    2011-01-01

    Emerging evidence indicates that ethanol-induced alterations in hepatic methionine metabolism play a central role in the pathogenesis of alcoholic liver disease (ALD). Because malnutrition is a universal clinical finding in this disease and hepatic methionine metabolism is dependent upon dietary folate and vitamins B-6 and B-12, ALD can be considered an induced nutritional disorder that is conditioned by alcohol abuse. The present review describes the etiologies of these 3 vitamin deficiencies in ALD and how they interact with chronic ethanol exposure to alter hepatic methionine metabolism. Subsequent sections focus on molecular mechanisms for the interactions of aberrant methionine metabolism with ethanol in the pathogenesis of ALD, in particular the role of S-adenosylmethionine (SAM) in regulating the epigenetic expressions of genes relevant to pathways of liver injury. The review will conclude with descriptions of studies on the efficacy of SAM in the treatment of ALD and with discussion of potentially fruitful future avenues of research. PMID:22332083

  16. Salmonella: Dry Pet Foods and Pet Treats (FAQ)

    Science.gov (United States)

    ... Guides Reports Salmonella: Dry Pet Foods and Pet Treats (FAQ) Originally posted August 9, 2010; Updated August ... as a result of the outbreak. “Natural” pet treats , such as pig ears and dehydrated/dried beef ...

  17. Conversion of Methionine to Thiols by Lactococci, Lactobacilli, and Brevibacteria†

    OpenAIRE

    Dias, Benjamin; Weimer, Bart

    1998-01-01

    Methanethiol has been strongly associated with desirable Cheddar cheese flavor and can be formed from the degradation of methionine (Met) via a number of microbial enzymes. Methionine γ-lyase is thought to play a major role in the catabolism of Met and generation of methanethiol in several species of bacteria. Other enzymes that have been reported to be capable of producing methanethiol from Met in lactic acid bacteria include cystathionine β-lyase and cystathionine γ-lyase. The objective of ...

  18. A new cytokine: the possible effect pathway of methionine enkephalin

    Institute of Scientific and Technical Information of China (English)

    Xin-Hua Liu; Dong-Ai Huang; Fei-Yi Yang; Yan-Sheng Hao; Guo-Guang Du; Ping-Feng Li; Gang Li

    2003-01-01

    AIM: To investigate experimentally the effects of methionineenkephalin on signal transduction of mouse myeloma NS-1cells.METHODS: The antigen determinate of delta opioidreceptor was designed in this lab and the polypeptidefragment of antigen determinate with 12 amino acidsresidues was synthesized. Monoclonal antibody against thispeptide fragment was prepared. Proliferation of Mouse NS-L cells treated with methionine enkephalin of 1x10-6 mol.L-1was observed. The activities of protein kinase A (PKA) andprotein kinase C (PKC) were measured and thereby themechanism of effect of methionine enkephalin was postulated.RESULTS: The results demonstrated that methionineenkephalin could enhance the proliferation of NS-1 cells andthe effect of methionine enkephalin could be particularlyblocked by monoclonal antibody. The activity of PKA wasincreased in both cytosol and cell membrane. With referenceto PKC, the intracellular activity of PKC in NS-1 cells waselevated at 1x10-7 mol.L-1 and then declined gradually asthe concentration of methionine enkephalin was raised. Theeffects of methionine enkephalin might be reversed by bothnaloxone and monoclonal antibody.CONCLUSION: Coupled with the findings, it in-dicates thatthe signal transduction systems via PKA and PKC are involvedin the effects of methionine enkephalin by binding with thetraditional opioid receptors, and therefore resulting in differentbiological effects.

  19. Protein Methionine Sulfoxide Dynamics in Arabidopsis thaliana under Oxidative Stress.

    Science.gov (United States)

    Jacques, Silke; Ghesquière, Bart; De Bock, Pieter-Jan; Demol, Hans; Wahni, Khadija; Willems, Patrick; Messens, Joris; Van Breusegem, Frank; Gevaert, Kris

    2015-05-01

    Reactive oxygen species such as hydrogen peroxide can modify proteins via direct oxidation of their sulfur-containing amino acids, cysteine and methionine. Methionine oxidation, studied here, is a reversible posttranslational modification that is emerging as a mechanism by which proteins perceive oxidative stress and function in redox signaling. Identification of proteins with oxidized methionines is the first prerequisite toward understanding the functional effect of methionine oxidation on proteins and the biological processes in which they are involved. Here, we describe a proteome-wide study of in vivo protein-bound methionine oxidation in plants upon oxidative stress using Arabidopsis thaliana catalase 2 knock-out plants as a model system. We identified over 500 sites of oxidation in about 400 proteins and quantified the differences in oxidation between wild-type and catalase 2 knock-out plants. We show that the activity of two plant-specific glutathione S-transferases, GSTF9 and GSTT23, is significantly reduced upon oxidation. And, by sampling over time, we mapped the dynamics of methionine oxidation and gained new insights into this complex and dynamic landscape of a part of the plant proteome that is sculpted by oxidative stress.

  20. [NMR screening of potential inhibitors of Citrobacter freundii methionine].

    Science.gov (United States)

    Batuev, E A; Lizunov, A Iu; Morozova, E A; Klochkov, V V; Anufrieva, N V; Demidkina, T V; Pol'shakov, V I

    2014-01-01

    Methionine γ-lyase [EC 4.4.1.11] participates in a methionine catabolism at a number of bacteria and protozoa eukaryotes, including pathogenic microorganisms. Lack of this enzyme at mammals allows consider it as a perspective target for rational antibacterial drug design. Currently in medical practice there are no the preparations based on an inhibition of methionine γ-lyase activity. We present results of the search of potential inhibitors of the enzyme using the NMR screening techniques based on identification of compounds, which able to bind specifically to their biological target. Study included a stage of in silico virtual screening of the library of commercially available compounds and subsequent experimental selection of the leading compounds, capable to interact with enzyme. Identification of binding was carried out by means of saturation transfer difference (STD) spectroscopy and WaterLOGSY technique. At the final stage the experimental assessment of inhibiting ability of the selected compounds in the reaction of γ-elimination of L-methionine catalyzed by methionine γ-lyase was carried out. Binding constants of two leading compounds were determined using the WaterLOGSY method. The research expands structural group of potential inhibitors of methionine γ-lyase and allows approach to the design of the inhibitors with higher efficacy.

  1. Methionine salvage pathway in relation to ethylene biosynthesis

    International Nuclear Information System (INIS)

    The recycling of methionine during ethylene biosynthesis (the methionine cycle) was studied. During ethylene biosynthesis, the H3CS-group of S-adenosylmethionine (SAM) is released at 5'-methylthioadenosine (MTA), which is recycled to methionine via 5'-methylthioribose (MTS). In mungbean hypocotyls and cell-free extracts of avocado fruit, [14C]MTR was converted to labeled methionine via 2-keto-4-methylthiobutyric acid (KMB) and 2-hydroxy-4-methylthiobutyric acid (HMB) as intermediates. Radioactive tracer studies showed that KMB was converted readily in vivo and in vitro to methionine, while HMB was converted much more slowly. The conversion of KMB to methionine by dialyzed avocado extract required an amino group donor. Among several potential donors tested, L-glutamine was the most efficient. Incubation of [ribose-U-14C]MTR with avocado extract resulted in the production of [14C]formate, with little evolution of other 14C-labeled one-carbon compounds, indicating that the conversion of MTR to KMB involves a loss of formate, presumably from C-1 of MTR

  2. Synthesis and carbon-11 labeling of (R)- and (S)-thionisoxetine, norepinephrine reuptake inhibitors, potential radioligands for positron emission tomography

    International Nuclear Information System (INIS)

    Standards and des-methyl precursors of (R)- and (S)-thionisoxetine, potent and selective norepinephrine reuptake inhibitors, were synthesized and radiolabeled with carbon-11. Both enantiomers of the N-methyl-3-(2-thiomethylphenoxy)-3-phenylpropanamine and the 3-(2-thiomethylphenoxy)-3-phenylpropylamine were obtained via multi-step syntheses, while the radiosyntheses were carried out using [11C]CH3I. The radiochemical yields were 26%, decay corrected and the specific radioactivity ranging from 2 to 3 Ci/μmol. The HPLC analyses were performed using a chiral column: during the radiolabeling, no racemization occurred and the isomers were synthesized with high enantiomeric purity

  3. Synthesis of suicide inhibitors of monoamine oxidase: carbon-11 labeled clorgyline, L-deprenyl and D-deprenyl

    International Nuclear Information System (INIS)

    The suicide inhibitors of monoamine oxidase type A and B, clorgyline and L-deprenyl have been labeled with carbon-11 by [11C]methylation of the norbases with [11C]H3I. The less active enantiomer of deprenyl (D-deprenyl) was also labeled using this procedure. The synthesis time was 35 minutes, the radiochemical yield was 25-40% and the specific activity was 0.8-2.0 Ci/μmol (calculated to EOB). Procedures for synthesis of the precursor norbases as well as the synthesis of unlabeled clorgyline, L-deprenyl and D-deprenyl are given. (author)

  4. Comparison of 99mTc-labeled methionine and 11C methionine radiotracer in the detection of breast carcinomas

    International Nuclear Information System (INIS)

    The cost effectiveness and non-availability of Cyclotron in underdeveloped and developing countries is a basic problem. Therefore studies were undertaken after labeling Methionine with generator produced Technetium-99m for its possible use in breast cancer imaging

  5. Report on compounds labelled with nitrogen-13 or carbon-11 used in cancer metabolic studies with quantitative two-dimensional scanning and pet tomography

    International Nuclear Information System (INIS)

    The use of compounds labelled with radionuclides of the elements commonly involved in metabolic processes (oxygen, carbon, nitrogen) is becoming important in the non-invasive study of organ and tumour function. The application of compounds labelled with 13N and 11C to the study of amino-acid metabolism and changes in vasculature following chemotherapy and radiation therapy is described. In particular, 13N-labelled L-glutamate has been found to be useful in visualizing a number of human tumours including osteogenic sarcoma, rhabdomyosarcoma, Ewing's sarcoma, malignant fibrous histiocytoma, pineal gland tumours, primitive neuroectodermal tumours, medulloblastoma and several other solid tumours. In patients with bone tumours, changes in 13N-L-glutamate scans during chemotherapy were found to correlate with changes in other clinical parameters, such as serum alkaline phosphatase, histology and 99Tcsup(m)-bone scans, thus indicating that labelled L-glutamate is potentially useful in evaluating the response of solid tumours to chemotherapy. Scans of patients and volunteers using 13N-L-glutamate and 13N-L-valine indicate that the L-amino acids may be useful in studies of metabolic processes in the liver, myocardium and pancreas. Red blood cells, labelled with 11C-carbon monoxide via inhalation of the radioactive gas, have been used to assess changes in tumour vascularity following radiation therapy. Alpha-aminoisobutyric acid labelled with 11C has been synthesized and its distribution in normal and tumour-bearing dogs has been studied. (author)

  6. Clinical PET application

    Energy Technology Data Exchange (ETDEWEB)

    Lim, Sang Moo; Hong, Song W.; Choi, Chang W.; Yang, Seong Dae [Korea Cancer Center Hospital, Seoul (Korea)

    1997-12-01

    PET gives various methabolic images, and is very important, new diagnostic modality in clinical oncology. In Korea Cancer Center Hospital, PET is installed as a research tool of long-mid-term atomic research project. For the efficient use of PET for clinical and research projects, income from the patients should be managed to get the raw material, equipment, manpower, and also for the clinical PET research. 1. Support the clinical application of PET in oncology. 2. Budgetary management of income, costs for raw material, equipment, manpower, and the clinical PET research project. In this year, 250 cases of PET images were obtained, which resulted total income of 180,000,000 won. 50,000,000 won was deposited for the 1998 PET clinical research. Second year PET clinical research should be managed under unified project. Increased demand for {sup 18}FDG in and outside KCCH need more than 2 times production of {sup 18}FDG in a day purchase of HPLC pump and {sup 68}Ga pin source which was delayed due to economic crisis, should be done early in 1998. (author). 2 figs., 3 tabs.

  7. The low-methionine content of vegan diets may make methionine restriction feasible as a life extension strategy.

    Science.gov (United States)

    McCarty, Mark F; Barroso-Aranda, Jorge; Contreras, Francisco

    2009-02-01

    Recent studies confirm that dietary methionine restriction increases both mean and maximal lifespan in rats and mice, achieving "aging retardant" effects very similar to those of caloric restriction, including a suppression of mitochondrial superoxide generation. Although voluntary caloric restriction is never likely to gain much popularity as a pro-longevity strategy for humans, it may be more feasible to achieve moderate methionine restriction, in light of the fact that vegan diets tend to be relatively low in this amino acid. Plant proteins - especially those derived from legumes or nuts - tend to be lower in methionine than animal proteins. Furthermore, the total protein content of vegan diets, as a function of calorie content, tends to be lower than that of omnivore diets, and plant protein has somewhat lower bioavailability than animal protein. Whole-food vegan diets that moderate bean and soy intake, while including ample amounts of fruit and wine or beer, can be quite low in methionine, while supplying abundant nutrition for health (assuming concurrent B12 supplementation). Furthermore, low-fat vegan diets, coupled with exercise training, can be expected to promote longevity by decreasing systemic levels of insulin and free IGF-I; the latter effect would be amplified by methionine restriction - though it is not clear whether IGF-I down-regulation is the sole basis for the impact of low-methionine diets on longevity in rodents.

  8. Efficacy of C-11 L-methionine positron emission tomography and intraoperative methylene blue staining for localization of parathyroid glands in primary hyperparathyroidism

    Energy Technology Data Exchange (ETDEWEB)

    Takahashi, Hiromasa; Takahashi, Masato; Taguchi, Kazunori; Takada, Naoyuki; Nakada, Kunihiro; Sasaki, Fumiaki; Todo, Satoru [Hokkaido Univ., Sapporo (Japan). School of Medicine

    2002-12-01

    For localization of parathyroid glands in primary hyperparathyroidism we carried out C-11 L-methionine positron emission tomography (Met-PET) in 10 patients (one with hyperplasia and 9 with adenoma) and intraoperative methylene blue staining in 20 patients (one with hyperplasia and 19 with adenoma) and compared the predictive value with that of US and {sup 99m}Tc-sestamibi scintigraphy (MIBI). Methylene blue was administrated at a calculated dose of 5 mg/kg body weight intravenously for 1 h before surgery. The accuracy of identification of pathological parathyroid glands with Met-PET, US and MIBI was 90%, 80% and 70% respectively. Met-PET was more sensitive than US and MIBI and could identify smaller parathyroid glands, particularly in cases with lower serum calcium levels. Met-PET imaging was not affected even in 2 reoperative cases. Intraoperative methylene blue staining of parathyroid glands was successful in 19 patients without major side effects. Met-PET was the most effective method for preoperative imaging of parathyroid glands. Intraoperative methylene blue staining was a safe and effective method and able to facilitate dissection of pathological glands during surgery. (author)

  9. My Pet Rock

    Science.gov (United States)

    Lark, Adam; Kramp, Robyne; Nurnberger-Haag, Julie

    2008-01-01

    Many teachers and students have experienced the classic pet rock experiment in conjunction with a geology unit. A teacher has students bring in a "pet" rock found outside of school, and the students run geologic tests on the rock. The tests include determining relative hardness using Mohs scale, checking for magnetization, and assessing luster.…

  10. Genetic engineering for high methionine grain legumes.

    Science.gov (United States)

    Müntz, K; Christov, V; Saalbach, G; Saalbach, I; Waddell, D; Pickardt, T; Schieder, O; Wüstenhagen, T

    1998-08-01

    Methionine (Met) is the primary limiting essential amino acid in grain legumes. The imbalance in amino acid composition restricts their biological value (BV) to 55 to 75% of that of animal protein. So far improvement of the BV could not be achieved by conventional breeding. Therefore, genetic engineering was employed by several laboratories to resolve the problem. Three strategies have been followed. A) Engineering for increased free Met levels; B) engineering of endogenous storage proteins with increased numbers of Met residues; C) transfer of foreign genes encoding Met-rich proteins, e.g. the Brazil nut 2S albumin (BNA) and its homologue from sunflower, into grain legumes. The latter strategy turned out to be most promising. In all cases the gene was put under the control of a developmentally regulated seed specific promoter and transferred into grain legumes using the bacterial Agrobacterium tumefaciens-system. Integration into and copy numbers in the plant genome as well as Mendelian inheritance and gene dosage effects were verified. After correct precursor processing the mature 2S albumin was intracellularly deposited in protein bodies which are part of the vacuolar compartment. The foreign protein amounted to 5 to 10% of the total seed protein in the best transgenic lines of narbon bean (Vicia narbonensis L., used in the authors' laboratories), lupins (Lupinus angustifolius L., used in CSIRO, Australia), and soybean (Glycine max (L.) Merr., used by Pioneer Hi-Bred, Inc., USA). In the narbon bean the increase of Met was directly related to the amount of 2S albumin in the transgenic seeds, but in soybean it remained below the theoretically expected value. Nevertheless, trangenic soybean reached 100%, whereas narbon bean and lupins reached approximately 80% of the FAO-standard for nutritionally balanced food proteins. These results document that the Met problem of grain legumes can be resolved by genetic engineering.

  11. Mammals Reduce Methionine-S-sulfoxide with MsrA and Are Unable to Reduce Methionine-R-sulfoxide, and This Function Can Be Restored with a Yeast Reductase*S⃞

    OpenAIRE

    Lee, Byung Cheon; Le, Dung Tien; Gladyshev, Vadim N.

    2008-01-01

    Methionine is an essential amino acid in mammals at the junction of methylation, protein synthesis, and sulfur pathways. However, this amino acid is highly susceptible to oxidation, resulting in a mixture of methionine-S-sulfoxide and methionine-R-sulfoxide. Whether methionine is quantitatively regenerated from these compounds is unknown. Here we report that SK-Hep1 hepatocytes grew on methionine-S-sulfoxide and consumed this compound by import and methionine-S-sulfoxi...

  12. Usage of Recycled Pet

    Directory of Open Access Journals (Sweden)

    A. Ebru Tayyar

    2010-01-01

    Full Text Available The increasing industrialization, urbanization and the technological development have caused to increase depletion of the natural resources and environmental pollution's problem. Especially, for the countries which have not enough space recycling of the waste eliminating waste on regular basis or decreasing the amount and volume of waste have provided the important advantages. There are lots of studies and projects to develop both protect resources and prevent environmental pollution. PET bottles are commonly used in beverage industry and can be reused after physical and chemical recycling processes. Usage areas of recycled PET have been developed rapidly. Although recycled PET is used in plastic industry, composite industry also provides usage alternatives of recycled PET. Textile is a suitable sector for recycling of some plastics made of polymers too. In this study, the recycling technologies and applications of waste PET bottles have been investigated and scientific works in this area have been summarized.

  13. PET and PET/CT for imaging of prostate cancer

    International Nuclear Information System (INIS)

    This review article provides an overview of the current literature data regarding the value of PET and PET/CT for imaging of prostate cancer. Most widely used PET tracers for prostate cancer imaging are 11C-acetate and 11C- or 18F-labeled choline. Available literature data on the performance of PET and PET/CT in the detection of the primary malignancy as well as local or distant metastases are presented and discussed. In addition, our own preliminary results regarding the diagnostic efficacy of 11C-choline PET and PET/CT in 43 patients with suspected prostate cancer are provided. The prevalence of prostate cancer in this patient sample was 55.8%. PET and PET/CT showed a sensitivity of 88% with a specificity of 63% in the detection of the primary prostate cancer. The sensitivity in the detection of metastatic spread was 77% and no false-positives were found. The possible value and limitations of combined PET/CT systems when compared to stand alone PET scanners are discussed. PET and PET/CT is at present the single imaging modality providing functional information not only regarding the primary malignancy but also its metastases. This unique feature distinguishes PET from MRI complemented with magnetic resonance spectroscopy - a competing procedure. Our own results as well as the still limited literature data suggest, that PET and PET/CT may prove to be useful methods for imaging of prostate cancer. (orig.)

  14. Effect of excess methionine and methionine hydroxy analogue on growth performance and plasma homocysteine of growing Pekin ducks.

    Science.gov (United States)

    Xie, M; Hou, S S; Huang, W; Fan, H P

    2007-09-01

    One experiment was conducted to study the effect of excess dl-methionine (DLM) and dl-2-hydroxy-4-methylthiobutanoic acid free acid (dl-HMB-FA) on duck growth. One-day-old male white Pekin ducklings were fed common starter diets from hatch to 21 d of age and then fed the experimental diets from 21 to 42 d of age. Three hundred twenty 21-d-old birds were allotted to 40 raised wire-floor pens with 8 birds per pen according to similar pen weight. There were 5 dietary treatments that included a methionine-adequate control diet and control diets supplemented with 2 levels of dry DLM (1 or 2%) or 2 equimolar levels of liquid dl-HMB-FA (1.13 or 2.26%). Each dietary treatment was replicated 8 times. At 42 d of age, weight gain, feed intake, and gain/feed were measured and plasma was collected to analyze homocysteine. Compared with ducks fed control diets, excess DLM or dl-HMB-FA supplementation reduced weight gain and feed intake of birds significantly. However, on the equimolar basis, at 1 or 2% supplemental methionine activity, dl-HMB-FA was less growth-depressing than DLM. According to the growth response to excess methionine, the tolerable upper limit of dietary methionine for growing ducks may be less than 1.38% when the methionine level of the control diet (0.38%) was considered. On the other hand, plasma homocysteine was elevated markedly when 2% DLM or 2.26% dl-HMB-FA was added to control diets, but plasma homocysteine of ducks fed 2.26% dl-HMB-FA supplemented diets was lower significantly than birds fed equimolar DLM-supplemented diets, which indicated the toxicity of excess methionine sources and less toxicity of dl-HMB-FA relative to DLM.

  15. AUTOMATION FOR THE SYNTHESIS AND APPLICATION OF PET RADIOPHARMACEUTICALS.

    Energy Technology Data Exchange (ETDEWEB)

    Alexoff, D.L.

    2001-09-21

    The development of automated systems supporting the production and application of PET radiopharmaceuticals has been an important focus of researchers since the first successes of using carbon-11 (Comar et al., 1979) and fluorine-18 (Reivich et al., 1979) labeled compounds to visualize functional activity of the human brain. These initial successes of imaging the human brain soon led to applications in the human heart (Schelbert et al., 1980), and quickly radiochemists began to see the importance of automation to support PET studies in humans (Lambrecht, 1982; Langstrom et al., 1983). Driven by the necessity of controlling processes emanating high fluxes of 511 KeV photons, and by the tedium of repetitive syntheses for carrying out these human PET investigations, academic and government scientists have designed, developed and tested many useful and novel automated systems in the past twenty years. These systems, originally designed primarily by radiochemists, not only carry out effectively the tasks they were designed for, but also demonstrate significant engineering innovation in the field of laboratory automation.

  16. Utilization of PET imaging in differential diagnostics between a tumefactive multiple sclerosis lesion and low-grade glioma.

    Science.gov (United States)

    Tarkkonen, Aleksi; Rissanen, Eero; Tuokkola, Terhi; Airas, Laura

    2016-09-01

    We present a case where a 30-year-old man with a history of combined MS and Charcot-Marie-Tooth (CMT I) disease was additionally diagnosed and treated for grade II glioma (astrocytoma). Tumefactive MS and gliomas are sometimes difficult to distinguish from one another based on conventional magnetic resonance imaging (MRI). In our case, positron emission tomography (PET) scans with(11)C-methionine ((11)C-MET) and (11)C-PK11195 radioligands were performed to aid in differential diagnostics. The diagnosis was confirmed finally by brain biopsy. The usefulness of PET imaging in differential diagnostics between tumefactive MS and glioma is discussed. PMID:27645363

  17. Monitoring methionine sulfoxide with stereospecific mechanism-based fluorescent sensors.

    Science.gov (United States)

    Tarrago, Lionel; Péterfi, Zalán; Lee, Byung Cheon; Michel, Thomas; Gladyshev, Vadim N

    2015-05-01

    Methionine can be reversibly oxidized to methionine sulfoxide (MetO) under physiological and pathophysiological conditions, but its use as a redox marker suffers from the lack of tools to detect and quantify MetO within cells. In this work, we created a pair of complementary stereospecific genetically encoded mechanism-based ratiometric fluorescent sensors of MetO by inserting a circularly permuted yellow fluorescent protein between yeast methionine sulfoxide reductases and thioredoxins. The two sensors, respectively named MetSOx and MetROx for their ability to detect S and R forms of MetO, were used for targeted analysis of protein oxidation, regulation and repair as well as for monitoring MetO in bacterial and mammalian cells, analyzing compartment-specific changes in MetO and examining responses to physiological stimuli.

  18. Crystallography captures catalytic steps in human methionine adenosyltransferase enzymes.

    Science.gov (United States)

    Murray, Ben; Antonyuk, Svetlana V; Marina, Alberto; Lu, Shelly C; Mato, Jose M; Hasnain, S Samar; Rojas, Adriana L

    2016-02-23

    The principal methyl donor of the cell, S-adenosylmethionine (SAMe), is produced by the highly conserved family of methionine adenosyltranferases (MATs) via an ATP-driven process. These enzymes play an important role in the preservation of life, and their dysregulation has been tightly linked to liver and colon cancers. We present crystal structures of human MATα2 containing various bound ligands, providing a "structural movie" of the catalytic steps. High- to atomic-resolution structures reveal the structural elements of the enzyme involved in utilization of the substrates methionine and adenosine and in formation of the product SAMe. MAT enzymes are also able to produce S-adenosylethionine (SAE) from substrate ethionine. Ethionine, an S-ethyl analog of the amino acid methionine, is known to induce steatosis and pancreatitis. We show that SAE occupies the active site in a manner similar to SAMe, confirming that ethionine also uses the same catalytic site to form the product SAE.

  19. In vivo kinetics and displacement study of a carbon-11-labeled hallucinogen, N,N-[11C]dimethyltryptamine

    International Nuclear Information System (INIS)

    The endogenous hallucinogen, N,N-dimethyltryptamine (DMT), was labeled with carbon-11 and its regional distribution in rat brain studied. [11C]DMT showed higher accumulation in the cerebral cortex, caudate putamen, and amygdaloid nuclei. Studies of the subcellular distribution of [11C]DMT revealed the specific localization in the fractions enriched with serotonin receptors only when a very low dose was injected into rats. The proportions of the radioactivity in receptor-rich fractions were greatly enhanced by pretreatment with the monoamine oxidase inhibitor, pargyline. Specific binding of [11C]DMT to serotonin receptors in dog brain was demonstrated by a positron emission tomographic study in which 5-methoxy-N,N-dimethyltryptamine caused approximately 20% displacement of the radioligand from the receptors. (orig.)

  20. In vivo kinetics and displacement study of a carbon-11-labeled hallucinogen, N,N-(/sup 11/C)dimethyltryptamine

    Energy Technology Data Exchange (ETDEWEB)

    Yanai, Kazuhiko; Ido, Tatsuo; Ishiwata, Kiichi; Takahashi, Toshihiro; Iwata, Ren; Hatazawa, Jun; Matsuzawa, Taiju

    1986-07-01

    The endogenous hallucinogen, N,N-dimethyltryptamine (DMT), was labeled with carbon-11 and its regional distribution in rat brain studied. (/sup 11/C)DMT showed higher accumulation in the cerebral cortex, caudate putamen, and amygdaloid nuclei. Studies of the subcellular distribution of (/sup 11/C)DMT revealed the specific localization in the fractions enriched with serotonin receptors only when a very low dose was injected into rats. The proportions of the radioactivity in receptor-rich fractions were greatly enhanced by pretreatment with the monoamine oxidase inhibitor, pargyline. Specific binding of (/sup 11/C)DMT to serotonin receptors in dog brain was demonstrated by a positron emission tomographic study in which 5-methoxy-N,N-dimethyltryptamine caused approximately 20% displacement of the radioligand from the receptors.

  1. In vivo kinetics and displacement study of a carbon-11-labeled hallucinogen, N,N-[11C]dimethyltryptamine.

    Science.gov (United States)

    Yanai, K; Ido, T; Ishiwata, K; Hatazawa, J; Takahashi, T; Iwata, R; Matsuzawa, T

    1986-01-01

    The endogenous hallucinogen, N,N-dimethyltryptamine (DMT), was labeled with carbon-11 and its regional distribution in rat brain studied. [11C]DMT showed higher accumulation in the cerebral cortex, caudate putamen, and amygdaloid nuclei. Studies of the subcellular distribution of [11C]DMT revealed the specific localization in the fractions enriched with serotonin receptors only when a very low dose was injected into rats. The proportions of the radioactivity in receptor-rich fractions were greatly enhanced by pretreatment with the monoamine oxidase inhibitor, pargyline. Specific binding of [11C]DMT to serotonin receptors in dog brain was demonstrated by a positron emission tomographic study in which 5-methoxy-N,N-dimethyltryptamine caused approximately 20% displacement of the radioligand from the receptors. PMID:3489620

  2. Biodistribution of a positron-emitting suicide inactivator of monoamine oxidase, carbon-11 pargyline, in mice and a rabbit

    International Nuclear Information System (INIS)

    Carbon-11 (11C) pargyline, which is a suicide inactivator of Type B monoamine oxidase (MAO), was synthesized by the reaction of N-demethylpargyline with 11CH3l. Biodistribution was investigated in mice, and positron tomographic images of the heart and lung in a rabbit were obtained. The distribution of 11C after administration of [11C]pargyline was measured in several organs and blood at various time intervals. After 30 min its concentrations in the organs were constant. Subcellular distribution studies in the brain, lung, liver, and kidney showed that 59-70% of the 11C became acid-insoluble and 9-33% was present in the crude mitochondrial fraction at 60 min after injection. The uptakes of the 11C in each organ except for the kidney and spleen seemed to correlate with the in vitro enzymatic activity of Type B MAO. At high loading dose a nonspecific uptake was observed

  3. A comparative study of two novel nanosized radiolabeled analogues of methionine for SPECT tumor imaging.

    Science.gov (United States)

    Khosroshahi, A G; Amanlou, M; Sabzevari, O; Daha, F J; Aghasadeghi, M R; Ghorbani, M; Ardestani, M S; Alavidjeh, M S; Sadat, S M; Pouriayevali, M H; Mousavi, L; Ebrahimi, S E S

    2013-01-01

    It has been reported that most tumor cells show an increased uptake of variety of amino acids specially methionine when compared with normal cells and amino acid transport is generally increased in malignant transformation. Based on the evidences, two novel nanosized analogues of methionine (Anionic Linear Globular Dendrimer G(2), a biodigredabale anionic linear globular-Methionin, and DTPA-Methionine(1) conjugates) were synthesized and labeled with (99m)Tc and used in tumor imaging/ therapy in vitro and in vivo. The results showed marked tumor SPECT molecular imaging liabilities for both compounds but with a better performance by administration of (99m)Tc-Dendrimer G(2)-Methionin. The results also showed a good anticancer activity for 99mTc-DTPA-Methionine. Based on the present study (99m)Tc-Dendrimer G(2)-Methionin or 99mTc-DTPA-(Methionine)(1) have potentials to be used in tumor molecular imaging as well as cancer therapy in future.

  4. Characterisation of methionine adenosyltransferase from Mycobacterium smegmatis and M. tuberculosis

    Directory of Open Access Journals (Sweden)

    Knodel Marvin H

    2003-06-01

    Full Text Available Abstract Background Tuberculosis remains a serious world-wide health threat which requires the characterisation of novel drug targets for the development of future antimycobacterials. One of the key obstacles in the definition of new targets is the large variety of metabolic alterations that occur between cells in the active growth and chronic/dormant phases of tuberculosis. The ideal biochemical target should be active in both growth phases. Methionine adenosyltransferase, which catalyses the formation of S-adenosylmethionine from methionine and ATP, is involved in polyamine biosynthesis during active growth and is also required for the methylation and cyclopropylation of mycolipids necessary for survival in the chronic phase. Results The gene encoding methionine adenosyltransferase has been cloned from Mycobacterium tuberculosis and the model organism M. smegmatis. Both enzymes retained all amino acids known to be involved in catalysing the reaction. While the M. smegmatis enzyme could be functionally expressed, the M. tuberculosis homologue was insoluble and inactive under a large variety of expression conditions. For the M. smegmatis enzyme, the Vmax for S-adenosylmethionine formation was 1.30 μmol/min/mg protein and the Km for methionine and ATP was 288 μM and 76 μM respectively. In addition, the enzyme was competitively inhibited by 8-azaguanine and azathioprine with a Ki of 4.7 mM and 3.7 mM respectively. Azathioprine inhibited the in vitro growth of M. smegmatis with a minimal inhibitory concentration (MIC of 500 μM, while the MIC for 8-azaguanine was >1.0 mM. Conclusion The methionine adenosyltransferase from both organisms had a primary structure very similar those previously characterised in other prokaryotic and eukaryotic organisms. The kinetic properties of the M. smegmatis enzyme were also similar to known prokaryotic methionine adenosyltransferases. Inhibition of the enzyme by 8-azaguanine and azathioprine provides a starting

  5. Separation Of Methionine Enantiomers By Using Teicoplanin And Cyclofructan Columns

    Directory of Open Access Journals (Sweden)

    Hroboňová Katarína

    2015-06-01

    Full Text Available Methionine is a naturally occurring amino acid. Its enantiomeric separation by using high performance liquid chromatography on various types of chiral stationary phases was studied. The effect of mobile phase composition on enantioselectivity and retention was considered. The separation of the enantiomers was attained in different separation modes – reversed phase mode for the macrocyclic antibiotic chiral stationary phases (teicoplanin, teicoplanin aglycone, normal phase and polar organic phase modes for the isopropyl carbamate cyclofructan 6 chiral stationary phase. It was shown that the hydrogen bonding, dipole interactions, steric effects between methionine molecules and stationary phases play an important role in the separation of enantiomers.

  6. Traumatic brain injury alters methionine metabolism: implications for pathophysiology

    Directory of Open Access Journals (Sweden)

    Pramod K Dash

    2016-04-01

    Full Text Available Methionine is an essential proteinogenic amino acid that is obtained from the diet. In addition to its requirement for protein biosynthesis, methionine is metabolized to generate metabolites that play key roles in a number of cellular functions. Metabolism of methionine via the transmethylation pathway generates S-adenosylmethionine (SAM that serves as the principal methyl (-CH3 donor for DNA and histone methyltransferases to regulate epigenetic changes in gene expression. SAM is also required for methylation of other cellular proteins that serve various functions and phosphatidylcholine synthesis that participate in cellular signaling.. Under conditions of oxidative stress, homocysteine (which is derived from SAM enters the transsulfuration pathway to generate glutathione, an important cytoprotective molecule against oxidative damage. As both experimental and clinical studies have shown that traumatic brain injury (TBI alters DNA and histone methylation and causes oxidative stress, we examined if TBI alters the plasma levels of methionine and its metabolites in human patients. Blood samples were collected from healthy volunteers (n = 20 and patients with mild TBI (GCS > 12; n = 20 or severe TBI (GCS < 8; n = 20 within the first 24 hours of injury. The levels of methionine and its metabolites in the plasma samples were analyzed by either liquid chromatography-mass spectrometry or gas chromatography-mass spectrometry (LC-MS or GC-MS. Severe TBI decreased the levels of methionine, SAM, betaine and 2-methylglycine as compared to healthy volunteers, indicating a decrease in metabolism through the transmethylation cycle. In addition, precursors for the generation of glutathione, cysteine and glycine were also found to be decreased as were intermediate metabolites of the gamma-glutamyl cycle (gamma-glutamyl amino acids and 5-oxoproline. Mild TBI also decreased the levels of methionine, α-ketobutyrate, 2 hydroxybutyrate and glycine, albeit to lesser

  7. Novel tracer for radiation treatment planning; Welche neuen PET-Tracer braucht die Strahlentherapie?

    Energy Technology Data Exchange (ETDEWEB)

    Schwarzenboeck, S.; Krause, B.J. [Rostock Univ. (Germany). Klinik fuer Nuklearmedizin; Herrmann, K.; Gaertner, F.; Souvatzoglou, M. [Technische Univ. Muenchen (Germany). Klinik fuer Nuklearmedizin; Klaesner, B. [Klinikum Bogenhausen, Muenchen (Germany). Inst. fuer Radiologie und Nuklearmedizin

    2011-07-15

    PET and PET/CT with innovative tracers gain increasing importance in diagnosis and therapy management, and radiation treatment planning in radio-oncology besides the widely established FDG. The introduction of [{sup 18}F]Fluorothymidine ([{sup 18}F]FLT) as marker of proliferation, [{sup 18}F]Fluoromisonidazole ([{sup 18}F]FMISO) and [{sup 18}F]Fluoroazomycin-Arabinoside ([{sup 18}F]FAZA) as tracer of hypoxia, [{sup 18}F]Fluoroethyltyrosine ([{sup 18}F]FET) and [{sup 11}C]Methionine for brain tumour imaging, [{sup 68}Ga]DOTATOC for somatostatin receptor imaging, [{sup 18}F]FDOPA for dopamine synthesis and radioactively labeled choline derivatives for imaging phospholipid metabolism have opened novel approaches to tumour imaging. Some of these tracers have already been implemented into radio-oncology: Amino acid PET and PET/CT have the potential to optimise radiation treatment planning of brain tumours through accurate delineation of tumour tissue from normal tissue, necrosis and edema. Hypoxia represents a major therapeutic problem in radiation therapy. Hypoxia imaging is very attractive as it may allow to increase the dose in hypoxic tumours potentially allowing for a better tumour control. Advances in hybrid imaging, i.e. the introduction of MR/PET, may also have an impact in radio-oncology through synergies related to the combination of molecular signals of PET and a high soft tissue contrast of MRI as well as functional MRI capabilities. (orig.)

  8. 21 CFR 582.5477 - Methionine hydroxy analog and its calcium salts.

    Science.gov (United States)

    2010-04-01

    ... 21 Food and Drugs 6 2010-04-01 2010-04-01 false Methionine hydroxy analog and its calcium salts... Nutrients and/or Dietary Supplements 1 § 582.5477 Methionine hydroxy analog and its calcium salts. (a) Product. Methionine hydroxy analog and its calcium salts. (b) (c) Limitations, restrictions,...

  9. Determination of the specific activities of methionine sulfoxide reductase A and B by capillary electrophoresis

    Science.gov (United States)

    A capillary electrophoresis (CE) method for the determination of methionine sulfoxide reductase A and methionine sulfoxide reductase B activities in mouse liver is described. The method is based on detection of the 4-(dimethylamino)azobenzene-4’-sulfonyl derivative of L-methionine (dabsyl Met), the ...

  10. Your Pet's Medications

    Science.gov (United States)

    ... by Animal/Species Browse by Topic Browse by Discipline Resources VMA Resource Center Tools for K-12 ... infection because giving the preventive to a heartworm-positive pet will not treat the infection and could ...

  11. Cold Weather Pet Safety

    Science.gov (United States)

    ... Emergency Care Animal Welfare Veterinary Careers Public Health Cold Weather Pet Safety Client Handout Available for download ... in hot cars , but did you know that cold weather also poses serious threats to your pets’ ...

  12. Clinical application of PET

    Energy Technology Data Exchange (ETDEWEB)

    Lomena, Francisco [Hospital Clinico Villarroel, Barcelona (Spain). Nuclear Medicine]. E-mail: flomena@clinic.ub.es; Soler, Marina [CETIR Grup Medic. Esplkugues de Llobregat, Barcelona (Spain). PET Unit

    2005-10-15

    Positron emission tomography (PET) is an imaging modality that gives information on tissue metabolism and functionalism, different from other imaging techniques like computed tomography (CT) and magnetic resonance imaging (MRI), which provide anatomical or structural information. PET has reached its development in biomedical research because of its capacity to use analogous compounds of many endogenous substance as tracers, and to measure, in vivo and in a non-invasive way, their consumption by the different organs and tissues of the mammalian body. Fluorodeoxyglucose-F 18 (FDG) PET has been proven to be a tracer adequate for clinical use in oncology and in many neurological diseases, with an excellent cost-efficiency ratio. The current PET-CT scanners can come to be the best tools for exploring patients who suffer from cancer.(author)

  13. Clinical application of pet

    OpenAIRE

    Francisco Lomeña; Marina Soler

    2005-01-01

    Positron emission tomography (PET) is an imaging modality that gives information on tissue metabolism and functionalism, different from other imaging techniques like computed tomography (CT) and magnetic resonance imaging (MRI), which provide anatomical or structural information. PET has reached its development in biomedical research because of its capacity to use analogous compounds of many endogenous substance as tracers, and to measure, in vivo and in a non-invasive way, their consumption ...

  14. Technical Note: Methionine, a precursor of methane in living plants

    Science.gov (United States)

    Lenhart, K.; Althoff, F.; Greule, M.; Keppler, F.

    2015-03-01

    When terrestrial plants were identified as producers of the greenhouse gas methane, much discussion and debate ensued not only about their contribution to the global methane budget but also with regard to the validity of the observation itself. Although the phenomenon has now become more accepted for both living and dead plants, the mechanism of methane formation in living plants remains to be elucidated and its precursor compounds to be identified. We made use of stable isotope techniques to verify the in vivo formation of methane, and, in order to identify the carbon precursor, 13C positionally labeled organic compounds were employed. Here we show that the amino acid L-methionine acts as a methane precursor in living plants. Employing 13C-labeled methionine clearly identified the sulfur-bound methyl group of methionine as a carbon precursor of methane released from lavender (Lavandula angustifolia). Furthermore, when lavender plants were stressed physically, methane release rates and the stable carbon isotope values of the emitted methane greatly increased. Our results provide additional support that plants possess a mechanism for methane production and suggest that methionine might play an important role in the formation of methane in living plants, particularly under stress conditions.

  15. Oxidized methionine is not a prion-specific covalent modification

    Science.gov (United States)

    The oxidation of methionine residues in the '-helical region of PrPC has been proposed to be important for prion formation. This proposal has been supported by structural studies, model systems and antibody-based experimental evidence. We developed a sensitive mass spectrometry-based method to stu...

  16. Technical note: Methionine, a precursor of methane in living plants

    Directory of Open Access Journals (Sweden)

    K. Lenhart

    2014-11-01

    Full Text Available When terrestrial plants were identified as producers of the greenhouse gas methane, much discussion and debate ensued, not only about their contribution to the global methane budget, but also with regard to the validity of the observation itself. Although the phenomenon has now become more accepted for both living and dead plants, the mechanism of methane formation in living plants remains to be elucidated and its precursor compounds identified. We made use of stable isotope techniques to verify in vivo formation of methane and, in order to identify the carbon precursor, 13C-positionally labelled organic compounds were employed. Here we show that the amino acid L-methionine acts as a methane precursor in living plants. Employing 13C-labelled methionine clearly identified the sulphur-bound methyl group of methionine as a carbon precursor of methane released from lavender (Lavandula angustifolia. Furthermore, when lavender plants were stressed physically, methane release rates and the stable carbon isotope values of the emitted methane greatly increased. Our results provide additional support that plants possess a mechanism for methane production and suggest that methionine might play an important role in the formation of methane in living plants, particularly under stress conditions.

  17. Methionine enkephalin: immunomodulator in normal volunteers, cancer and AIDS patients

    Directory of Open Access Journals (Sweden)

    Nicholas P. Plotnikoff

    1987-01-01

    Full Text Available Clinical studies of the immunological effects of methionine enkephalin in normal volunteers, cancer, and AIDS patients are summarized. The major immunology changes seen were increases in T cell subsets, natural killer activity, as well as mitogen blastogenesis. Clinically, the cancer and ARC patients did not develop infections.

  18. 21 CFR 172.372 - N-Acetyl-L-methionine.

    Science.gov (United States)

    2010-04-01

    ... HUMAN CONSUMPTION (CONTINUED) FOOD ADDITIVES PERMITTED FOR DIRECT ADDITION TO FOOD FOR HUMAN CONSUMPTION Special Dietary and Nutritional Additives § 172.372 N-Acetyl-L-methionine. The food additive N-acetyl-L... section. The minimum amount of the additive to achieve the desired effect must be used, and the...

  19. FDG-PET and MET-PET for differentiation between benign lesions and lung cancer in pneumoconiosis

    International Nuclear Information System (INIS)

    We retrospectively assessed the usefulness of fluorodeoxyglucose-positron emission tomography (FDG-PET) and methionine (MET)-PET for the differentiation between benign lesions and lung cancer in patients with pneumoconiosis. A total of 54 patients with pneumoconiosis underwent both wholebody MET-PET and FDG-PET on the same day. Of the 54 patients, 50 were former coal miners. These patients were divided into three groups. The first was lung cancer group, which consisted of 12 patients with pneumoconiosis (4 with squamous cell carcinoma, 6 with adenocarcinoma, 1 with small cell carcinoma, 1 with large cell carcinoma). The second was benign lesion group, which consisted of 21 patients with pneumoconiosis. These subject had no evidence of lung cancer, which was confirmed on the basis of a long term follow-up to date. The third was control group, which consisted of 21 patients with pneumoconiosis. In the pneumoconiotic nodules, significant correlation between nodule size and standardized uptake value (SUV)max of the two PET tracers were observed, and the SUVmax of MET was lower than that of FDG. The SUVmax of benign lesions were not different from that of pneumoconiotic nodules. In FDG and MET-PET study, the SUVmax of lung cancer measuring more than 2 cm and less than 3 cm in diameter were significantly higher than that of pneumoconiotic nodules. In the 3 cases of bronchiolo-alveolar cell carcinoma (BAC), no abnormal accumulation was observed by either FDG or MET. A cut-off value of SUVmax of FDG-PET which we determined for differentiating lung cancer from pneumoconiotic nodules is 4 in nodules with diameter less than 3 cm, 6 with diameter more than 3 cm and less than 4 cm, and 9 with diameter more than 4 cm. In MET-PET, a cut-off value of SUVmax is 5. On the basis of these criteria, FDG and MET identified lung cancer other than BAC with sensitivity of 89% (8/9), specificity of 96% (90/94). Our results suggest that quantitative assessment of uptake of FDG and MET

  20. Comparison of autologous 111In-leukocytes, 18F-FDG, 11C-methionine, 11C-PK11195 and 68Ga-citrate for diagnostic nuclear imaging in a juvenile porcine haematogenous Staphylococcus aureus osteomyelitis model

    DEFF Research Database (Denmark)

    Nielsen, Ole Lehberg; Afzelius, Pia; Bender, Dirk;

    2014-01-01

    The aim of this study was to compare 111In-labeled leukocyte single-photon emission computed tomography (SPECT) and 18F-fluorodeoxyglucose (18F-FDG) positron emission tomography (PET) to PET with tracers that potentially could improve detection of osteomyelitis. We chose 11C-methionine, 11C-PK11195...... protocol with 18F-FDG, 68Ga-citrate, 11C-methionine, 11C-PK11195, 99mTc-Nanocoll and 111In-labelled autologous leukocytes. This was followed by necropsy of the pigs and gross pathology, histopathology and microbial examination. The pigs developed a total of five osteomyelitis lesions, five lesions...... characterized as abscesses/cellulitis, arthritis in three joints and five enlarged lymph nodes. None of the tracers accumulated in joints with arthritis. By comparing the 10 infectious lesions, 18F-FDG accumulated in nine, 111In-leukocytes in eight, 11C-methionine in six, 68Ga-citrate in four and 11C-PK11195...

  1. Tissue methionine cycle activity and homocysteine metabolism in female rats: impact of dietary methionine and folate plus choline

    NARCIS (Netherlands)

    Wilson, F.A.; Borne, van den J.J.G.C.; Calder, A.G.; O'Kennedy, N.; Holtrop, G.; Rees, W.D.; Lobley, G.E.

    2009-01-01

    Impaired transfer of methyl groups via the methionine cycle leads to plasma hyperhomocysteinemia. The tissue sources of plasma homocysteine in vivo have not been quantified nor whether hyperhomocysteinemia is due to increased entry or decreased removal. These issues were addressed in female rats off

  2. Enhanced anticancer effect of vincristine with methionine infusion after methionine-depleting total parenteral nutrition in tumor-bearing rats.

    Science.gov (United States)

    Goseki, N; Nagahama, T; Maruyama, M; Endo, M

    1996-02-01

    Methionine-depleting total parenteral nutrition (Met(-) TPN), in which an amino acid solution devoid of L-methionine and L-cysteine is infused, is thought to reduce tumor cell growth through acting as a partial late S-G2 (i.e., late-S and G2 phases) blocker. The antitumor effect of vincristine (VCR), which acts on mitotic phase cells, was examined with methionine infusion immediately after Met(-) TPN in Yoshida sarcoma (YS)-bearing rats. Rats were given Met(-) TPN for 8 days immediately after inoculation with YS cells (days 0 to 8), which was followed by methionine-containing (Met(+)) regular TPN for 3 days (days 9-11) along with intraperitoneal administration of 0.05 mg/kg/day VCR. All rats were then fed solid food and water ad libitum until they died, with 0.1 mg/kg VCR administration on days 12 and 13. As controls, a Met(-) TPN only group, Met(+) TPN groups with and without VCR, and freely fed groups with and without VCR were studied. The progression of YS was markedly suppressed by Met(-) TPN with VCR. The median survival time in days was 25 days, significantly longer (Pmethionine after Met(-) TPN.

  3. Engineering of methionine chain elongation part of glucoraphanin pathway in E. coli

    DEFF Research Database (Denmark)

    Mirza, Nadia Muhammad Akram; Crocoll, Christoph; Olsen, Carl Erik;

    2016-01-01

    The methionine-derived glucosinolate glucoraphanin is associated with the health-promoting properties of broccoli. This has developed a strong interest in producing this compound in high amounts from a microbial source. Glucoraphanin synthesis starts with a five-gene chain elongation pathway...... that converts methionine to dihomo-methionine, which is subsequently converted to glucoraphanin by the seven-gene glucosinolate core structure pathway. As dihomo-methionine is the precursor amino acid for glucoraphanin production, a first challenge is to establish an expression system for production of dihomo-methionine....... In planta, the methionine chain elongation enzymes are physically separated within the cell with the first enzyme in the cytosol while the rest are located in the chloroplast. A de-compartmentalization approach was applied to produce dihomo-methionine by expression of the respective plant genes...

  4. Efficacy of DL-methionine hydroxy analogue-free acid in comparison to DL-methionine in growing male white Pekin ducks.

    Science.gov (United States)

    Kluge, H; Gessner, D K; Herzog, E; Eder, K

    2016-03-01

    The present study was performed to assess the bioefficacy of DL-methionine hydroxy analogue-free acid (MHA) in comparison to DL-methionine (DLM) as sources of methionine for growing male white Pekin ducks in the first 3 wk of life. For this aim, 580 1-day-old male ducks were allocated into 12 treatment groups and received a basal diet that contained 0.29% of methionine, 0.34% of cysteine and 0.63% of total sulphur containing amino acids or the same diet supplemented with either DLM or MHA in amounts to supply 0.05, 0.10, 0.15, 0.20, and 0.25% of methionine equivalents. Ducks fed the control diet without methionine supplement had the lowest final body weights, daily body weight gains and feed intake among all groups. Supplementation of methionine improved final body weights and daily body weight gains in a dose dependent-manner. There was, however, no significant effect of the source of methionine on all of the performance responses. Evaluation of the data of daily body weight gains with an exponential model of regression revealed a nearly identical efficacy (slope of the curves) of both compounds for growth (DLM = 100%, MHA = 101%). According to the exponential model of regression, 95% of the maximum values of daily body weight gain were reached at methionine supplementary levels of 0.080% and 0.079% for DLM and MHA, respectively. Overall, the present study indicates that MHA and DLM have a similar efficacy as sources of methionine for growing ducks. It is moreover shown that dietary methionine concentrations of 0.37% are required to reach 95% of the maximum of daily body weight gains in ducks during the first 3 wk of life.

  5. Novel PET sensors

    International Nuclear Information System (INIS)

    This thesis describes the design, synthesis and evaluation of novel molecular sensors that utilize the phenomena of Photoinduced Electron Transfer (PET). PET design can be incorporated into molecules to allow them to selectively bind certain guest molecules. PET works by the modulation of electron potentials within a molecule. Binding events between a host and guest can, if designed suitably, change these potentials enough to cause a transfer of electronic charge within the molecular sensor. This event can be accurately and sensitively monitored by the use of ultra violet or fluorescence spectroscopy. A sensor molecule can be constructed by matching the guest to a suitable receptor site and incorporating this into a molecule containing a fluorophore with the correct electron potential characteristics. By using existing synthetic routes as well as exploiting new pathways these sensor molecules C n be constructed to contain a fluorophore separated from a guest receptor(s) by suitable spacers units. When put together these facets go to creating molecules that by design are sensitive and selective for certain guest molecules or functional groups. This methodology allows the synthetic chemist to rationally design and synthesise PET sensors, tailored to the needs of the guest. In this thesis the synthesis and evaluation of a novel PET sensors for D-glucosamine, disaccharides and fluoride is presented. It is believed that the novel sensors using the PET phenomenon presented in this thesis are a worthwhile extension of previous works undertaken by other groups around the world and shows new pathways to increasingly complex and sophisticated sensor molecular design. (author)

  6. Clinical application of pet

    Directory of Open Access Journals (Sweden)

    Francisco Lomeña

    2005-10-01

    Full Text Available Positron emission tomography (PET is an imaging modality that gives information on tissue metabolism and functionalism, different from other imaging techniques like computed tomography (CT and magnetic resonance imaging (MRI, which provide anatomical or structural information. PET has reached its development in biomedical research because of its capacity to use analogous compounds of many endogenous substance as tracers, and to measure, in vivo and in a non-invasive way, their consumption by the different organs and tissues of the mammalian body. Fluordeoxyglucose-F18 (FDG PET has been proven to be a tracer adequate for clinical use in oncology and in many neurological diseases, with an excellent cost-efficiency ratio. The current PET-CT scanners can come to be the best tools for exploring patients who suffer from cancer.A tomografia por emissão de pósitrons (PET é uma técnica de diagnóstico por imagem que fornece informação sobre o metabolismo e funcionamento dos tecidos, diferente de outras técnicas de imagens como tomografia computadorizada (TC e ressonância magnética (RM, as quais fornecem informações estruturais ou anatômicas. O PET alcançou seu desenvolvimento em investigação biomédica devido à sua capacidade de usar traçadores análogos a muitas substâncias endógenas e de medir in vivo e de forma não invasiva seu consumo em diferentes órgãos e tecidos dos mamíferos 18Fluordesoxiglicose (FDG PET tem provado ser uma exploração de uso clínico com excelente relação custo benefício em oncologia e em muitas doenças neurológicas. Os atuais tomógrafos por PET-CT podem chegar a ser a melhor ferramenta de diagnóstico nos pacientes que sofrem de câncer.

  7. Effect of cysteine on methionine production by a regulatory mutant of Corynebacterium lilium

    Energy Technology Data Exchange (ETDEWEB)

    Kumar, Dharmendra; Subramanian, Kartik; Bisaria, Virendra S.; Sreekrishnan, T.R.; Gomes, James [Indian Inst. of Technology, Dept. of Biochemical Engineering and Biotechnology, New Delhi (India)

    2005-02-01

    The production of methionine by submerged fermentation using a mutant strain of Corynebacterium lilium was studied to determine suitable conditions for obtaining high productivity. The mutant strain resistant to the methionine analogues ethionine, norleucine, methionine sulfoxide and methionine methylsulfonium chloride produced 2.34 g l{sup -1} of methionine in minimal medium containing glucose as carbon source. The effect of cysteine on methionine production in a 15 l bioreactor was studied by supplementing cysteine intermittently during the course of fermentation. The addition of cysteine (0.75 g l{sup -1} h{sup -1}) every 2 h to the production medium increased the production of methionine to 3.39 g l{sup -1}. A metabolic flux analysis showed that during cysteine supplementation the ATP consumption reduced by 20%. It also showed that the increase in flux from phosphoenol pyruvate to oxaloacetate leads to higher methionine production. Results indicate that controlling the respiratory quotient close to 0.75 will produce the highest amount of methionine and that regulatory mutants also resistant to analogues of cysteine would be better methionine over producers. (Author)

  8. Total cyanide mass measurement with micro-ion selective electrode for determination of specific activity of carbon-11 cyanide

    International Nuclear Information System (INIS)

    In this research, we aim to directly measure the specific activity (SA) of the carbon-11 cyanide ([11C]CN¯) produced by our in-house built automated [11C]HCN production system and to identify the major sources of 12C-cyanide (12CN¯). The [11C]CN¯ is produced from [11C]CO2, which is generated by the 14N(p,α)11C nuclear reaction using a cyclotron. Direct measurement of cyanide concentrations was accomplished using a relatively inexpensive, and easy to use ion selective electrode (ISE) which offered an appropriate range of sensitivity for detecting mass. Multiple components of the [11C]HCN production system were isolated in order to determine their relative contributions to 12CN¯ mass. It was determined that the system gases were responsible for approximately 30% of the mass, and that the molecular sieve/nickel furnace unit contributed approximately 70% of the mass. Beam on target (33 µA for 1 and 10 min) did not contribute significantly to the mass. Additionally, we compared the SA of our [11C]HCN precursor determined using the ISE to the SA of our current [11C]CN¯ derived radiotracers determined by HPLC to assure there was no significant difference between the two methods. These results are the first reported use of an ion selective electrode to determine the SA of no-carrier-added cyanide ion, and clearly show that it is a valuable, inexpensive and readily available tool suitable for this purpose. - Highlights: • Measurement of cyanide mass contribution from different component of automated [11C]HCN production system. • Determination of specific activity of [11C]HCN by micro ion selective electrode

  9. The ''in vivo'' distribution of carbon 11 labeled-nicotine in animals. A method suitable for use in man

    International Nuclear Information System (INIS)

    A method is described to label nicotine with carbon 11. A hundred millicuries can be obtained, in 45 minutes, with a high specific activity. This labeling of nicotine has allowed an ''in vivo'' study of the distribution of this very toxic drug in animals. Five minutes after injection in rabbits or monkeys, it was shown with a gamma camera or with a positron camera that the radioactivity was very rapidly distributed throughout the tissues especially in brain, lungs and kidneys. 11C-nicotine readily penetrates the blood-brain barrier and the brain radioactivity decreases very sharply with time. The eyes however retained activity, possibly in the retina. Unfortunately the monkey is not the ideal subject for 11C-nicotine brain study because: the brain is small, considering the resolution of the cameras and the cerebral lobes are also quite overlaped in this animal; Japanese authors have shown that compared with dogs the nicotine brain uptake is lower, due to the high affinity of nicotine for skeletal muscle which occupies approximately forty to fifty % of the body weight of the monkey. Also in monkeys, the nicotine destruction is faster than in dogs because there is a higher enzyme nicotine metabolizing activity in the liver of this animal. The differences observed between various animals studies using nicotine indicate that we should not draw any firm conclusions about the behaviour of this drug in humans. In order to do so, examinations must be conducted in man and the method described in spite of its limitations provides a means for such a study

  10. Separation Of Methionine Enantiomers By Using Teicoplanin And Cyclofructan Columns

    OpenAIRE

    Hroboňová Katarína; Deáková Zuzana; Moravčík Jakub; Lehotay Jozef; Armstrong Daniel W.; Lomenová Anna

    2015-01-01

    Methionine is a naturally occurring amino acid. Its enantiomeric separation by using high performance liquid chromatography on various types of chiral stationary phases was studied. The effect of mobile phase composition on enantioselectivity and retention was considered. The separation of the enantiomers was attained in different separation modes – reversed phase mode for the macrocyclic antibiotic chiral stationary phases (teicoplanin, teicoplanin aglycone), normal phase and polar organic p...

  11. PET pharmacokinetic analysis to estimate boron concentration in tumor and brain as a guide to plan BNCT for malignant cerebral glioma

    Energy Technology Data Exchange (ETDEWEB)

    Nariai, Tadashi [Department of Neurosurgery, Tokyo Medical and Dental University, 1-5-45 Yushima, Bunkyo-ku, Tokyo (Japan)], E-mail: nariai.nsrg@tmd.ac.jp; Ishiwata, Kiichi [Positron Medical Center, Tokyo Metropolitan Institute of Gerontology, 1-1, Nakacho, Itabashi-ku, Tokyo (Japan); Kimura, Yuichi [Molecular Imaging Center, National Institute of Radiological Sciences, 4-9-1 Anagawa, Inage-ku, Chiba (Japan); Inaji, Motoki; Momose, Toshiya [Department of Neurosurgery, Tokyo Medical and Dental University, 1-5-45 Yushima, Bunkyo-ku, Tokyo (Japan); Yamamoto, Tetsuya; Matsumura, Akira [Department of Neurosurgery, University of Tsukuba, Tennodai, Tsukuba, Igaraki (Japan); Ishii, Kenji [Positron Medical Center, Tokyo Metropolitan Institute of Gerontology, 1-1, Nakacho, Itabashi-ku, Tokyo (Japan); Ohno, Kikuo [Department of Neurosurgery, Tokyo Medical and Dental University, 1-5-45 Yushima, Bunkyo-ku, Tokyo (Japan)

    2009-07-15

    Introduction: To plan the optimal BNCT for patients with malignant cerebral glioma, estimation of the ratio of boron concentration in tumor tissue against that in the surrounding normal brain (T/N ratio of boron) is important. We report a positron emission tomography (PET) imaging method to estimate T/N ratio of tissue boron concentration based on pharmacokinetic analysis of amino acid probes. Methods: Twelve patients with cerebral malignant glioma underwent 60 min dynamic PET scanning of brain after bolus injection of {sup 18}F-borono-phenyl-alanine (FBPA) with timed arterial blood sampling. Using kinetic parameter obtained by this scan, T/N ratio of boron concentration elicited by one-hour constant infusion of BPA, as performed in BNCT, was simulated on Runge-Kutta algorithm. {sup 11}C-methionine (MET) PET scan, which is commonly used in worldwide PET center as brain tumor imaging tool, was also performed on the same day to compare the image characteristics of FBPA and that of MET. Result: PET glioma images obtained with FBPA and MET are almost identical in all patients by visual inspection. Estimated T/N ratio of tissue boron concentration after one-hour constant infusion of BPA, T/N ratio of FBPA on static condition, and T/N ratio of MET on static condition showed significant linear correlation between each other. Conclusion: T/N ratio of boron concentration that is obtained by constant infusion of BPA during BNCT can be estimated by FBPA PET scan. This ratio can also be estimated by MET-PET imaging. As MET-PET study is available in many clinical PET center, selection of candidates for BNCT may be possible by MET-PET images. Accurate planning of BNCT may be performed by static images of FBPA PET. Use of PET imaging with amino acid probes may contribute very much to establish an appropriate application of BNCT for patients with malignant glioma.

  12. PET/MR in oncology

    DEFF Research Database (Denmark)

    Balyasnikova, Svetlana; Löfgren, Johan; de Nijs, Robin;

    2012-01-01

    of the challenges inherent in this new technology, but focus on potential applications for simultaneous PET/MR in the field of oncology. Methods and tracers for use with the PET technology will be familiar to most readers of this journal; thus this paper aims to provide a short and basic introduction to a number...... be applied together with PET increasing the amount of information about the tissues of interest. The potential clinical benefit of applying PET/MR in staging, radiotherapy planning and treatment evaluation in oncology, as well as the research perspectives for the use of PET/MR in the development of new...

  13. Simultaneous PET and MR imaging

    International Nuclear Information System (INIS)

    We have developed a prototype PET detector which is compatible with a clinical MRI system to provide simultaneous PET and MR imaging. This single-slice PET system consists of 48 2x2x10mm3 LSO crystals in a 38 mm diameter ring configuration that can be placed inside the receiver coil of the MRI system, coupled to three multi-channel photomultipliers housed outside the main magnetic field via 4 m long and 2 mm diameter optical fibres. The PET system exhibits 2 mm spatial resolution, 41% energy resolution at 511 keV and 20 ns timing resolution. Simultaneous PET and MR phantom images were successfully acquired. (author)

  14. Comparative genomics of transcriptional regulation of methionine metabolism in Proteobacteria.

    Directory of Open Access Journals (Sweden)

    Semen A Leyn

    Full Text Available Methionine metabolism and uptake genes in Proteobacteria are controlled by a variety of RNA and DNA regulatory systems. We have applied comparative genomics to reconstruct regulons for three known transcription factors, MetJ, MetR, and SahR, and three known riboswitch motifs, SAH, SAM-SAH, and SAM_alpha, in ∼ 200 genomes from 22 taxonomic groups of Proteobacteria. We also identified two novel regulons: a SahR-like transcription factor SamR controlling various methionine biosynthesis genes in the Xanthomonadales group, and a potential RNA regulatory element with terminator-antiterminator mechanism controlling the metX or metZ genes in beta-proteobacteria. For each analyzed regulator we identified the core, taxon-specific and genome-specific regulon members. By analyzing the distribution of these regulators in bacterial genomes and by comparing their regulon contents we elucidated possible evolutionary scenarios for the regulation of the methionine metabolism genes in Proteobacteria.

  15. Comparative genomics of transcriptional regulation of methionine metabolism in Proteobacteria.

    Science.gov (United States)

    Leyn, Semen A; Suvorova, Inna A; Kholina, Tatiana D; Sherstneva, Sofia S; Novichkov, Pavel S; Gelfand, Mikhail S; Rodionov, Dmitry A

    2014-01-01

    Methionine metabolism and uptake genes in Proteobacteria are controlled by a variety of RNA and DNA regulatory systems. We have applied comparative genomics to reconstruct regulons for three known transcription factors, MetJ, MetR, and SahR, and three known riboswitch motifs, SAH, SAM-SAH, and SAM_alpha, in ∼ 200 genomes from 22 taxonomic groups of Proteobacteria. We also identified two novel regulons: a SahR-like transcription factor SamR controlling various methionine biosynthesis genes in the Xanthomonadales group, and a potential RNA regulatory element with terminator-antiterminator mechanism controlling the metX or metZ genes in beta-proteobacteria. For each analyzed regulator we identified the core, taxon-specific and genome-specific regulon members. By analyzing the distribution of these regulators in bacterial genomes and by comparing their regulon contents we elucidated possible evolutionary scenarios for the regulation of the methionine metabolism genes in Proteobacteria. PMID:25411846

  16. Cloning and Identification of Methionine Synthase Gene from Pichia pastoris

    Institute of Scientific and Technical Information of China (English)

    Lan HUANG; Dong-Yang LI; Shao-Xiao WANG; Shi-Ming ZHANG; Jun-Hui CHEN; Xiang-Fu WU

    2005-01-01

    Methionine synthase (MS) is grouped into two classes. Class One MS (MetH) and Class Two MS (MetE) share no homology and differ in their catalytic model. Based on the conserved sequences of metE genes from different organisms, a segment of the metE gene was first cloned from Pichia pastoris genomic DNA by PCR, and its 5' and 3' regions were further cloned by 5'- and 3'-rapid amplification of cDNA ends (RACE), respectively. The assembled sequence reveals an open reading frame encoding a polypeptide of 768 residues, and the deduced product shares 76% identity with MetE of Saccharomyces cerevisiae. P. pastoris methionine synthase (PpMetE) consists of two domains common to MetEs. The active site is located in the C-terminal domain, in which the residues involved in the interaction of zinc with substrates are conserved. Homologous expression of PpMetE in P. pastoris was achieved, and the heterologous expression of PpMetE in the S. cerevisiae strain XJB3-1D that is MetE-defective restored the growth of the mutant on methionine-free minimal media. The gene sequence has been submitted to GenBank/EMBL/DDBJ under accession No. AY601648.

  17. Comparison of MET-PET and FDG-PET for differentiation between benign lesions and lung cancer in pneumoconiosis

    International Nuclear Information System (INIS)

    The aim of this study was to evaluate and compare the ability of C-11-methionine (MET) and F-18 fluoro-deoxy-D-glucose positron emission tomography (FDG-PET) to diagnose lung cancer in patients with pneumoconiosis. Twenty-six subjects underwent both wholebody MET-PET and FDG-PET on the same day. The first group was a lung cancer group, which consisted of 15 patients, and included those with pneumoconiosis with increased nodules (13 cases), hemoptysis (1 case), and positive sputum cytology (1 case). The second group was a no-malignancy control group, consisting of 11 patients with pneumoconiosis. Significant correlations between nodule size and the maximum standardized uptake value (SUVmax) of the two PET tracers were observed in the control group. The larger the nodule size, the greater were the amounts of these tracers accumulated (MET: r=0.771, Pmax of MET was significantly lower than that of FDG in the pneumoconiotic nodules (Pmax of MET was significantly higher in the lung cancer than in the pneumoconiotic nodules, with 3.48±1.18 (mean ± SE) for the lung cancer and 1.48±0.08 for the pneumoconiotic nodules (Pmax of FDG, with 7.12±2.36 and 2.85±0.24 (P<0.05), respectively. On the basis of the criteria for the control group, FDG and MET identified lung cancer with sensitivities of 60% and 80%, specificities of 100% and 93%, accuracies of 90% and 90%, positive predictive values of 100% and 80%, and negative predictive values of 88% and 93%, respectively. Our results indicate that nodules with an intense uptake of MET and FDG relative to their size should be carefully observed because of a high risk for lung cancer. (author)

  18. Diagnostic Value of 11C-Methionine (MET and 18F-Fluorothymidine (FLT Positron Emission Tomography in Recurrent High-Grade Gliomas; Differentiation from Treatment-Induced Tissue Necrosis

    Directory of Open Access Journals (Sweden)

    Takashi Tamiya

    2012-03-01

    Full Text Available We retrospectively evaluated the usefulness of combined measurement of L-methyl-[11C]methionine (MET and 3'-deoxy-3'-[18F]fluorothymidine (FLT positron emission tomography (PET in the differential diagnosis between recurrent gliomas and necrotic lesions. Twenty-one patients with high-grade glioma, previously treated with surgery and radiotherapy with chemotherapy and first radiological suspicion of recurrence were enrolled. The uptake was assessed by the maximum standardized uptake value (SUVmax and lesion-to-normal tissue count density ratio (L/N ratio. Of the 21 lesions, 15 were diagnosed recurrent gliomas and six were necrotic lesions. The average SUVmax was not significantly different between recurrent gliomas and necrotic lesions on either MET-PET or FLT-PET. The average L/N ratio of recurrent gliomas (3.36 ± 1.06 was significantly higher than that of necrotic lesions (2.18 ± 0.66 on MET-PET (p < 0.01 and the average L/N ratio of recurrent gliomas (7.01 ± 2.26 was also significantly higher than that of necrotic lesions (4.60 ± 1.23 on FLT-PET (p < 0.01. ROC curve analysis showed that the areas under the curves were high but not different between MET- and FLT-PET. PET studies using MET and FLT are useful in the differentiation of recurrent glioma from treatment-induced necrotic lesion. However, there is no complementary information in the differentiation with simultaneous measurements of MET- and FLT-PET.

  19. Soluble methionine enhances accumulation of a 15 kDa zein, a methionine-rich storage protein, in transgenic alfalfa but not in transgenic tobacco plants.

    Science.gov (United States)

    Amira, Golan; Ifat, Matityahu; Tal, Avraham; Hana, Badani; Shmuel, Galili; Rachel, Amir

    2005-09-01

    With the general aim of elevating the content of the essential amino acid methionine in vegetative tissues of plants, alfalfa (Medicago sativa L.) and tobacco plants, as well as BY2 tobacco suspension cells, were transformed with a beta-zein::3HA gene under the 35S promoter of cauliflower mosaic virus encoding a rumen-stable methionine-rich storage protein of 15 kDa zein. To examine whether soluble methionine content limited the accumulation of the 15 kDa zein::3HA, methionine was first added to the growth medium of the different transgenic plants and the level of the alien protein was determined. Results demonstrated that the added methionine enhanced the accumulation of the 15 kDa zein::3HA in transgenic alfalfa and tobacco BY2 cells, but not in whole transgenic tobacco plants. Next, the endogenous levels of methionine were elevated in the transgenic tobacco and alfalfa plants by crossing them with plants expressing the Arabidopsis cystathionine gamma-synthase (AtCGS) having significantly higher levels of soluble methionine in their leaves. Compared with plants expressing only the 15 kDa zein::3HA, transgenic alfalfa co-expressing both alien genes showed significantly enhanced levels of this protein concurrently with a reduction in the soluble methionine content, thus implying that soluble methionine was incorporated into the 15 kDa zein::3HA. Similar phenomena also occurred in tobacco, but were considerably less pronounced. The results demonstrate that the accumulation of the 15 kDa zein::3HA is regulated in a species-specific manner and that soluble methionine plays a major role in the accumulation of the 15 kDa zein in some plant species but less so in others. PMID:16061510

  20. Healthy Pets and People

    Science.gov (United States)

    ... food and treats might include dry dog or cat food, dog biscuits, pig ears, beef hooves, and rodents ... after your pet, and before eating or preparing foods. Make sure to remove your ... contain dog or cat feces to prevent the spread of roundworms and ...

  1. I Love Petting Zoos!

    Centers for Disease Control (CDC) Podcasts

    2010-03-23

    This Kidtastics podcast helps children learn about how to stay safe and healthy when visiting petting zoos and other animal exhibits.  Created: 3/23/2010 by Centers for Disease Control and Prevention (CDC).   Date Released: 3/23/2010.

  2. Polyesteramides based on PET

    NARCIS (Netherlands)

    Bouma, Krista

    1999-01-01

    Engineering plastics have good mechanical, thermal and electrical properties, and can be easily processed. Typical engineering plastics include polyamides (PA6,6, PA6, PA4,6) and polyesters (PBT, PET). Compared to polyesters of a similar structure, polyamides have a high glass transition (Tg) and me

  3. Combined PET/MRI

    DEFF Research Database (Denmark)

    Bailey, D. L.; Pichler, B. J.; Gückel, B.;

    2015-01-01

    February 23 to 27, 2015. Specifically, we summarise the three days of invited presentations from active researchers in this and associated fields augmented by round table discussions and dialogue boards with specific topics. These include the use of PET/MRI in cardiovascular disease, paediatrics, oncology......, the conclusion of last year's meeting "the real work has just started" still holds true....

  4. PET CT and lymphomas

    International Nuclear Information System (INIS)

    This presentation is about Tc and lymphomas. Classification and clinical cases of various cancer such as gastro duodenal or ulcer, mama, medullary, lymph and neck, leukemia, nodular sclerosis. Metabolic information, anatomical nature of lymphoma and its clinical presentation determine the extent that PET should be used in the patient.

  5. PET and PET/CT in malignant melanoma; PET y PET/CT en melanoma maligno

    Energy Technology Data Exchange (ETDEWEB)

    Garcia O, J.R. [Nuclear Medicine and Molecular Imaging PET/CT, Centro Medico ABC, Mexico D.F. (Mexico)

    2007-07-01

    The advantages that it has the PET/CT are: 1. It diminishes mainly positive false lesions. It identifies physiologic accumulate places. 2. It diminishes in smaller grade false negative. Small injuries. Injuries with low grade concentration. Injure on intense activity areas. 3. Precise anatomical localization of accumulate places. 4. Reduction of the acquisition time. (Author)

  6. Choosing a Pet

    Institute of Scientific and Technical Information of China (English)

    2011-01-01

    THE capital boasts countless markets of all kinds,but some of its insect,bird and pet markets immortalize Beijing culture and folkloric traditions.Don’t miss it! The Huasheng Tianqiao Market,south of the famous Panjiayuan Antique Market, was moved a few years ago and rebuilt in the

  7. Kinetics of microbial methionine metabolism in continuous cultures administered different methionine sources.

    Science.gov (United States)

    Firkins, J L; Fowler, C M; Devillard, E; Bequette, B J

    2015-02-01

    The Met precursor 2-hydroxy-4-(methylthio) butanoic acid (HMB) is expected to be more extensively degraded in the rumen than its isopropyl ester (HMBi). A control and 3 isomolar treatments-0.097% dl-methionine, 0.11% HMBi (HMBi), and 0.055% HMBi plus 0.048% Met (Met + HMBi)-were dosed every 8h simultaneously with 3-times-daily feeding into continuous cultures. Starting on d 9, for 6 consecutive doses, both [1-(13)C]-l-Met and [methyl-(2)H3]-l-Met replaced part of the unlabeled dl-Met, [(13)C5]-dl-HMBi replaced a portion of the unlabeled dl-HMBi, and [1-(13)C]-l-Met plus [(13)C5]-dl-HMBi replaced a portion of the respective unlabeled doses for the Met + HMBi treatment. After the sixth dose (d 11), unlabeled Met or HMBi provided 100% of the doses to follow elimination kinetics of the labels in HMBi, free Met, and bacterial Met compartments. The free [1-(13)C]-l-Met recycled more and was recovered in bacterial Met to a lesser extent than was the free [methyl-(2)H3]-l-Met recycling and that was recovered in bacterial Met. Increasing HMBi inclusion (0, 50, and 100% substitution of the exogenously dosed Met on a molar equivalent basis) tended to increase HMBi escape from 54.7 to 71.3% for the 50 and 100% HMBi treatments, respectively. Despite HMBi substituting for and decreasing the dosage of Met, increasing HMBi increased accumulation of free Met in fermenter fluid. The HMBi (after de-esterification of the isopropyl group) presumably produces Met through the intermediate α-ketomethylthyiobutyrate with an aminotransferase that also has high affinity for branched-chain AA. We provide evidence that the HMBi-derived Met is likely released from bacterial cells and accumulates rather than being degraded, potentially as a result of lagging d-stereoisomer metabolism. More research is needed to evaluate racemization and metabolism of stereoisomers of HMBi, Met, and other AA in ruminal microbes.

  8. Oxidation of Methionine Residues in Polypeptide Ions Via Gas-Phase Ion/Ion Chemistry

    Science.gov (United States)

    Pilo, Alice L.; McLuckey, Scott A.

    2014-06-01

    The gas-phase oxidation of methionine residues is demonstrated here using ion/ion reactions with periodate anions. Periodate anions are observed to attach in varying degrees to all polypeptide ions irrespective of amino acid composition. Direct proton transfer yielding a charge-reduced peptide ion is also observed. In the case of methionine and, to a much lesser degree, tryptophan-containing peptide ions, collisional activation of the complex ion generated by periodate attachment yields an oxidized peptide product (i.e., [M + H + O]+), in addition to periodic acid detachment. Detachment of periodic acid takes place exclusively for peptides that do not contain either a methionine or tryptophan side chain. In the case of methionine-containing peptides, the [M + H + O]+ product is observed at a much greater abundance than the proton transfer product (viz., [M + H]+). Collisional activation of oxidized Met-containing peptides yields a signature loss of 64 Da from the precursor and/or product ions. This unique loss corresponds to the ejection of methanesulfenic acid from the oxidized methionine side chain and is commonly used in solution-phase proteomics studies to determine the presence of oxidized methionine residues. The present work shows that periodate anions can be used to `label' methionine residues in polypeptides in the gas phase. The selectivity of the periodate anion for the methionine side chain suggests several applications including identification and location of methionine residues in sequencing applications.

  9. Serine hydroxymethyltransferase: a key player connecting purine, folate and methionine metabolism in Saccharomyces cerevisiae.

    Science.gov (United States)

    Saint-Marc, Christelle; Hürlimann, Hans C; Daignan-Fornier, Bertrand; Pinson, Benoît

    2015-11-01

    Previous genetic analyses showed phenotypic interactions between 5-amino-4-imidazole carboxamide ribonucleotide 5'-phosphate (AICAR) produced from the purine and histidine pathways and methionine biosynthesis. Here, we revisited the effect of AICAR on methionine requirement due to AICAR accumulation in the presence of the fau1 mutation invalidating folinic acid remobilization. We found that this methionine auxotrophy could be suppressed by overexpression of the methionine synthase Met6 or by deletion of the serine hydroxymethyltransferase gene SHM2. We propose that in a fau1 background, AICAR, by stimulating the transcriptional expression of SHM2, leads to a folinic acid accumulation inhibiting methionine synthesis by Met6. In addition, we uncovered a new methionine auxotrophy for the ade3 bas1 double mutant that can be rescued by overexpressing the SHM2 gene. We propose that methionine auxotrophy in this mutant is the result of a competition for 5,10-methylenetetrahydrofolate between methionine and deoxythymidine monophosphate synthesis. Altogether, our data show intricate genetic interactions between one-carbon units, purine and methionine metabolism through fine-tuning of serine hydroxymethyltransferase by AICAR and the transcription factor Bas1.

  10. Methionine Metabolism Alters Oxidative Stress Resistance via the Pentose Phosphate Pathway.

    Science.gov (United States)

    Campbell, Kate; Vowinckel, Jakob; Keller, Markus A; Ralser, Markus

    2016-04-01

    Nutrient uptake and metabolism have a significant impact on the way cells respond to stress. The amino acid methionine is, in particular, a key player in the oxidative stress response, and acting as a reactive oxygen species scavenger, methionine is implicated in caloric restriction phenotypes and aging. We here provide evidence that some effects of methionine in stress situations are indirect and caused by altered activity of the nicotinamide adenine dinucleotide phosphate (NADPH) producing oxidative part of the pentose phosphate pathway (PPP). In Saccharomyces cerevisiae, both methionine prototrophic (MET15) and auxotrophic (met15Δ) cells supplemented with methionine showed an increase in PPP metabolite concentrations downstream of the NADPH producing enzyme, 6-phosphogluconate dehydrogenase. Proteomics revealed this enzyme to also increase in expression compared to methionine self-synthesizing cells. Oxidant tolerance was increased in cells preincubated with methionine; however, this effect was abolished when flux through the oxidative PPP was prevented by deletion of its rate limiting enzyme, ZWF1. Stress resistance phenotypes that follow methionine supplementation hence involve the oxidative PPP. Effects of methionine on oxidative metabolism, stress signaling, and aging have thus to be seen in the context of an altered activity of this NADP reducing pathway.

  11. Influence of protein level and supplemental methionine in practical rations for young endangered masked bobwhite quail

    Science.gov (United States)

    Serafin, J.A.

    1982-01-01

    A study was conducted to examine the protein requirement of young endangered masked Bobwhite quail (Colinus virginianus ridgwayi). Five practical starting rations containing 24 to 32% protein were fed alone and supplemented with methionine for 5 weeks. Supplemental methionine significantly improved growth of quail fed diets containing 24 and 26% protein. Increasing the protein level improved growth of quail fed unsupplemented diets but did not do so when diets contained supplemental methionine. A methionine-supplemented ration containing 24% protein appeared adequate for supporting rapid growth of masked Bobwhite quail.

  12. Oxidation of methionine residues in polypeptide ions via gas-phase ion/ion chemistry.

    Science.gov (United States)

    Pilo, Alice L; McLuckey, Scott A

    2014-06-01

    The gas-phase oxidation of methionine residues is demonstrated here using ion/ion reactions with periodate anions. Periodate anions are observed to attach in varying degrees to all polypeptide ions irrespective of amino acid composition. Direct proton transfer yielding a charge-reduced peptide ion is also observed. In the case of methionine and, to a much lesser degree, tryptophan-containing peptide ions, collisional activation of the complex ion generated by periodate attachment yields an oxidized peptide product (i.e., [M + H + O](+)), in addition to periodic acid detachment. Detachment of periodic acid takes place exclusively for peptides that do not contain either a methionine or tryptophan side chain. In the case of methionine-containing peptides, the [M + H + O](+) product is observed at a much greater abundance than the proton transfer product (viz., [M + H](+)). Collisional activation of oxidized Met-containing peptides yields a signature loss of 64 Da from the precursor and/or product ions. This unique loss corresponds to the ejection of methanesulfenic acid from the oxidized methionine side chain and is commonly used in solution-phase proteomics studies to determine the presence of oxidized methionine residues. The present work shows that periodate anions can be used to 'label' methionine residues in polypeptides in the gas phase. The selectivity of the periodate anion for the methionine side chain suggests several applications including identification and location of methionine residues in sequencing applications.

  13. Are Pets Good For Us?

    Institute of Scientific and Technical Information of China (English)

    邢连香

    2006-01-01

    A pet animal keeps us feel happy.Pets can staywith us when we are left by ourselves,and pets in-vite us to love and be loved.Often a cat or dog cankeep us easy at time when human words don’t help.Pets also keep us get close to the more natural animalworld.Learning to care for a pet helps a child to growup into a loving man or woman who feels responsible(有责任的) towards those dependent (依靠) on him.A pet dog can make us believe in others for we cansee faithfulness (忠诚) in the dog.In fact,we keeppets not only fo...

  14. Usage of Recycled Pet

    OpenAIRE

    A. Ebru Tayyar; Sevcan Üstün

    2010-01-01

    The increasing industrialization, urbanization and the technological development have caused to increase depletion of the natural resources and environmental pollution's problem. Especially, for the countries which have not enough space recycling of the waste eliminating waste on regular basis or decreasing the amount and volume of waste have provided the important advantages. There are lots of studies and projects to develop both protect resources and prevent environmental pollution. PET bot...

  15. PET studies in dementia

    International Nuclear Information System (INIS)

    Measurement of local cerebral glucose metabolism (lCMRGlc) by positron emission tomography (PET) and 18F-2-fluoro-2-deoxy-D-glucose (FDG) has become a standard technique during the past 20 years and is now available at many university hospitals in all highly developed countries. Many studies have documented a close relation between lCMRGlc and localized cognitive functions, such as language and visuoconstructive abilities. Alzheimer's disease (AD) is characterized by regional impairment of cerebral glucose metabolism in neocortical association areas (posterior cingulate, temporoparietal and frontal multimodal association cortex), whereas primary visual and sensorimotor cortex, basal ganglia, and cerebellum are relatively well preserved. In a multicenter study comprising 10 PET centers (Network for Efficiency and Standardization of Dementia Diagnosis, NEST-DD) that employed an automated voxel-based analysis of FDG PET images, the distinction between controls and AD patients was 93% sensitive and 93% specific, and even in very mild dementia (at Mini Mental Status Examination (MMSE) 24 or higher) sensitivity was still 84% at 93% specificity. Significantly abnormal metabolism in mild cognitive deficit (MCI) indicates a high risk to develop dementia within the next two years. Reduced neocortical glucose metabolism can probably be detected with FDG PET in AD on average one year before onset of subjective cognitive impairment. In addition to glucose metabolism, specific tracers for dopamine synthesis (18F-F-DOPA) and for (11C-MP4A) are of interest for differentiation among dementia subtypes. Cortical acetylcholine esterase activity (AChE) activity is significantly lower in patients with AD or with dementia with Lewy bodies (DLB) than in age-matched normal controls. In LBD there is also impairment of dopamine synthesis, similar to Parkinson disease. (author) 115 refs

  16. The effects of enhanced methionine synthesis on amino acid and anthocyanin content of potato tubers

    Directory of Open Access Journals (Sweden)

    Bánfalvi Zsófia

    2008-06-01

    Full Text Available Abstract Background Potato is a staple food in the diet of the world's population and also being used as animal feed. Compared to other crops, however, potato tubers are relatively poor in the essential amino acid, methionine. Our aim was to increase the methionine content of tubers by co-expressing a gene involved in methionine synthesis with a gene encoding a methionine-rich storage protein in potato plants. Results In higher plants, cystathionine γ-synthase (CgS is the first enzyme specific to methionine biosynthesis. We attempted to increase the methionine content of tubers by expressing the deleted form of the Arabidopsis CgS (CgSΔ90, which is not regulated by methionine, in potato plants. To increase the incorporation of free methionine into a storage protein the CgSΔ90 was co-transformed with the methionine-rich 15-kD β-zein. Results demonstrated a 2- to 6-fold increase in the free methionine content and in the methionine content of the zein-containing protein fraction of the transgenic tubers. In addition, in line with higher methionine content, the amounts of soluble isoleucine and serine were also increased. However, all of the lines with high level of CgSΔ90 expression were phenotypically abnormal showing severe growth retardation, changes in leaf architecture and 40- to 60% reduction in tuber yield. Furthermore, the colour of the transgenic tubers was altered due to the reduced amounts of anthocyanin pigments. The mRNA levels of phenylalanine ammonia-lyase (PAL, the enzyme catalysing the first step of anthocyanin synthesis, were decreased. Conclusion Ectopic expression of CgSΔ90 increases the methionine content of tubers, however, results in phenotypic aberrations in potato. Co-expression of the 15-kD β-zein with CgSΔ90 results in elevation of protein-bound methionine content of tubers, but can not overcome the phenotypical changes caused by CgSΔ90 and can not significantly improve the nutritional value of tubers. The level

  17. The role of new PET tracers for lung cancer.

    Science.gov (United States)

    Szyszko, Teresa A; Yip, Connie; Szlosarek, Peter; Goh, Vicky; Cook, Gary J R

    2016-04-01

    18F-fluorodeoxyglucose (18F-FDG) positron emission tomography-computed tomography (PET/CT) is established for characterising indeterminate pulmonary nodules and staging lung cancer where there is curative intent. Whilst a sensitive technique, specificity for characterising lung cancer is limited. There is recognition that evaluation of other aspects of abnormal cancer biology in addition to glucose metabolism may be more helpful in characterising tumours and predicting response to novel targeted cancer therapeutics. Therefore, efforts have been made to develop and evaluate new radiopharmaceuticals in order to improve the sensitivity and specificity of PET imaging in lung cancer with regards to characterisation, treatment stratification and therapeutic monitoring. 18F-fluorothymidine (18F-FLT) is a marker of cellular proliferation. It shows a lower accumulation in tumours than 18F-FDG as it only accumulates in the cells that are in the S phase of growth and demonstrates a low sensitivity for nodal staging. Its main role is in evaluating treatment response. Methionine is an essential amino acid. 11C-methionine is more specific and sensitive than 18F-FDG in differentiating benign and malignant thoracic nodules. 18Ffluoromisonidazole (18F-FMISO) is used for imaging tumour hypoxia. Tumour response to treatment is significantly related to the level of tumour oxygenation. Angiogenesis is the process by which new blood vessels are formed in tumours and is involved in tumour growth and metastatic tumour spread and is a therapeutic target. Most clinical studies have focused on targeted integrin PET imaging of which αvβ3 integrin is the most extensively investigated. It is upregulated on activated endothelial cells in association with tumour angiogenesis. Neuroendocrine tumour tracers, particularly 68Ga-DOTA-peptides, have an established role in imaging of carcinoid tumours. Whilst most of these tracers have predominantly been used in the research environment, they offer

  18. PET and Recycling

    Directory of Open Access Journals (Sweden)

    Funda Sevencan

    2007-08-01

    Full Text Available This review aims to clarify the need of decreasing the environmental effects caused by human and draw attention to the increasing environmental effects of plastics wastes. Plastics consist of organic molecules with high density molecules or polymers. Main resources of plastics are the residue of oil rafineries. Several advantages of plastics, have increased the usage continuously. Polyethylene Terephthalate (PET is the most commonly used plastics. PET is used to protect food, drinking water, fruit juice, alcoholic beverage, and food packing films. By the increasing interest on the environmental effects of plastic wastes, concerns on the recyclable packing materials also grew up. Also the daily use of recyclable containers consisting PET have increased. There are five steps for recycling of plastics. These steps are; using large amounts of plastics, collecting them in a big center, classifying and sorting the plastics, reproducing the polymers and obtaining new products with melted plastics. Providing a healthy recycling of plastics, the consumers should have knowledge and responsibility. The consumer should know what he/she has to do before putting the plastics in the recycling containers. Recycling containers and bags should be placed near the sources of plastic wastes. Consequently, the plastic wastes and environmental problems they cause will be on the agenda in future. [TAF Prev Med Bull. 2007; 6(4: 307-312

  19. Pet Overpopulation: An Economic Analysis

    OpenAIRE

    Coate, Stephen; Knight, Brian

    2009-01-01

    This paper considers the problem of pet overpopulation. It develops a tractable dynamic model whose positive predictions square well with key features of the current U.S. market for pets. The model is used to understand, from a welfare economic perspective, the sense in which there is \\overpopulation" of pets and the underlying causes of the problem. The paper also employs the model to consider what policies might be implemented to deal with the problem. A calibrated example is developed to i...

  20. Client services for geriatric pets.

    Science.gov (United States)

    Hancock, G; Yates, J

    1989-01-01

    Some veterinarians have been reluctant to discuss the prospect of the death of a pet because of a sense of discomfort and a lack of understanding about how to respond to the client's grief reaction. It is essential to take the time for this important communication and help clients deal with fears about the process, any feelings of guilt and helplessness, and judgments about the medical aspects of a case. Clients must be encouraged to express grief over the loss of a pet, particularly a geriatric pet that has lived with them many years and to which they are deeply bonded. Veterinarians need to counsel clients about obtaining additional pets or another pet. The phrase "replacement pet" must be stricken from the veterinarian's vocabulary. One does not "replace" a deceased spouse, mother, father, or child. It is possible to have another child or find another spouse, but it is not possible to replace a person. Neither can a pet be "replaced," because each pet is a unique living being. It is disrespectful to the memory of deceased pets to belittle their uniqueness by suggesting that they can be replaced. Instead, the veterinarian has the capability and responsibility to help pet owners maintain fond and happy memories of an irreplacable pet, while finding room in their hearts for another new pet to create happiness for the future. Once the grief is resolved, clients will be thankful for having had the privilege of sharing their life with an animal and experiencing the joy of the bond between two unique individuals. PMID:2646816

  1. Cyclotron/PET project in Uruguay

    International Nuclear Information System (INIS)

    The Positron Computed Tomography (PET) is a tri dimensional image technique which shows biochemical information. PET is used in neurology and cardiology diseases. The National Center Cyclotron PET has been found to research, development and health science applications.

  2. RPC PET: Status and perspectives

    Science.gov (United States)

    Couceiro, M.; Blanco, A.; Ferreira, Nuno C.; Ferreira Marques, R.; Fonte, P.; Lopes, L.

    2007-10-01

    The status of the resistive plate chamber (RPC)-PET technology for small animals is briefly reviewed and its sensitivity performance for human PET studied through Monte-Carlo simulations. The cost-effectiveness of these detectors and their very good timing characteristics open the possibility to build affordable Time of Flight (TOF)-PET systems with very large fields of view. Simulations suggest that the sensitivity of such systems for human whole-body screening, under reasonable assumptions, may exceed the present crystal-based PET technology by a factor up to 20.

  3. Extended suicide with a pet.

    Science.gov (United States)

    Cooke, Brian K

    2013-01-01

    The combination of the killing of a pet and a suicide is a perplexing scenario that is largely unexplored in the literature. Many forensic psychiatrists and psychologists may be unaccustomed to considering the significance of the killing of a pet. The subject is important, however, because many people regard their pets as members of their family. A case is presented of a woman who killed her pet dog and herself by carbon monoxide poisoning. The purpose of this article is to provide an initial exploration of the topic of extended suicide with a pet. Forensic mental health evaluations may have a role in understanding the etiology of this event and in opining as to the culpability of individuals who attempt to or successfully kill a pet and then commit suicide. Because the scientific literature is lacking, there is a need to understand this act from a variety of perspectives. First, a social and anthropological perspective will be presented that summarizes the history of the practice of killing of one's pet, with a focus on the ancient Egyptians. A clinical context will examine what relationship animals have to mental illness. A vast body of existing scientific data showing the relevance of human attachment to pets suggests that conclusions from the phenomena of homicide-suicide and filicide-suicide are applicable to extended suicide with a pet. Finally, recommendations will be proposed for both clinical and forensic psychiatrists faced with similar cases. PMID:24051598

  4. Carbon-11 labeled stilbene derivatives from natural products for the imaging of Aβ plaques in the brain

    International Nuclear Information System (INIS)

    Four stilbene derivatives from natural products were screened as novel β-amyloid (Aβ) imaging ligands. In vitro binding assay showed that the methylated ligand, (E)-1-methoxy-4-styrylbenzene (8) displayed high binding affinity to Aβ1-42 aggregates (Ki = 19.5 nM). Moreover, the 11C-labeled ligand, [11C]8 was prepared through an O-methylation reaction using [11C]CH3OTf. In vitro autoradiography with sections of transgenic mouse brain also confirmed the high and specific binding of [11C]8 to Aβ plaques. In vivo biodistribution experiments in normal mice indicated that [11C]8 displayed high initial uptake (9.41 ± 0.51% ID/g at 5 min post-injection) into and rapid washout from the brain, with a brain5min/brain30min ratio of 6.63. These preliminary results suggest that [11C]8 may be served as a novel Aβ imaging probe for PET. (orig.)

  5. 18F-FET-PET in Primary Hyperparathyroidism: A Pilot Study

    Science.gov (United States)

    Krakauer, Martin; Kjaer, Andreas; Bennedbæk, Finn N.

    2016-01-01

    Preoperative localisation of the diseased parathyroid gland(s) in primary hyperparathyroidism (PHP) is a prerequisite for subsequent minimally invasive surgery. Recently, as alternatives to conventional sestamibi parathyroid scintigraphy, the 11C-based positron emission tomography (PET) tracers methionine and choline have shown promise for this purpose. We evaluated the feasibility of using the 18F-based PET tracer fluoroethyl-l-tyrosine (FET), as the longer half-life of 18F makes it logistically more favourable. As a proof-of-concept study, we included two patients with PHP in which dual-isotope parathyroid subtraction single photon emission computed tomography had determined the exact location of the parathyroid adenoma. A dynamic FET PET/CT scan was performed with subsequent visual evaluation and calculation of target-to-background (TBR; parathyroid vs. thyroid). The maximum TBR in the two patients under study was achieved approximately 30 min after the injection of the tracer and was 1.5 and 1.7, respectively. This ratio was too small to allow for confident visualisation of the adenomas. FET PET/CT seems not feasible as a preoperative imaging modality in PHP. PMID:27548229

  6. 18F-FET-PET in Primary Hyperparathyroidism: A Pilot Study

    Directory of Open Access Journals (Sweden)

    Martin Krakauer

    2016-08-01

    Full Text Available Preoperative localisation of the diseased parathyroid gland(s in primary hyperparathyroidism (PHP is a prerequisite for subsequent minimally invasive surgery. Recently, as alternatives to conventional sestamibi parathyroid scintigraphy, the 11C-based positron emission tomography (PET tracers methionine and choline have shown promise for this purpose. We evaluated the feasibility of using the 18F-based PET tracer fluoroethyl-l-tyrosine (FET, as the longer half-life of 18F makes it logistically more favourable. As a proof-of-concept study, we included two patients with PHP in which dual-isotope parathyroid subtraction single photon emission computed tomography had determined the exact location of the parathyroid adenoma. A dynamic FET PET/CT scan was performed with subsequent visual evaluation and calculation of target-to-background (TBR; parathyroid vs. thyroid. The maximum TBR in the two patients under study was achieved approximately 30 min after the injection of the tracer and was 1.5 and 1.7, respectively. This ratio was too small to allow for confident visualisation of the adenomas. FET PET/CT seems not feasible as a preoperative imaging modality in PHP.

  7. (18)F-FET-PET in Primary Hyperparathyroidism: A Pilot Study.

    Science.gov (United States)

    Krakauer, Martin; Kjaer, Andreas; Bennedbæk, Finn N

    2016-01-01

    Preoperative localisation of the diseased parathyroid gland(s) in primary hyperparathyroidism (PHP) is a prerequisite for subsequent minimally invasive surgery. Recently, as alternatives to conventional sestamibi parathyroid scintigraphy, the (11)C-based positron emission tomography (PET) tracers methionine and choline have shown promise for this purpose. We evaluated the feasibility of using the (18)F-based PET tracer fluoroethyl-l-tyrosine (FET), as the longer half-life of (18)F makes it logistically more favourable. As a proof-of-concept study, we included two patients with PHP in which dual-isotope parathyroid subtraction single photon emission computed tomography had determined the exact location of the parathyroid adenoma. A dynamic FET PET/CT scan was performed with subsequent visual evaluation and calculation of target-to-background (TBR; parathyroid vs. thyroid). The maximum TBR in the two patients under study was achieved approximately 30 min after the injection of the tracer and was 1.5 and 1.7, respectively. This ratio was too small to allow for confident visualisation of the adenomas. FET PET/CT seems not feasible as a preoperative imaging modality in PHP. PMID:27548229

  8. Multimodal imaging utilising integrated MR-PET for human brain tumour assessment

    Energy Technology Data Exchange (ETDEWEB)

    Neuner, Irene [Institute of Neuroscience and Medicine 4, INM 4, Juelich (Germany); RWTH Aachen University, Department of Psychiatry, Psychotherapy and Psychosomatics, Aachen (Germany); JARA-BRAIN-Translational Medicine, Aachen (Germany); Kaffanke, Joachim B. [Institute of Neuroscience and Medicine 4, INM 4, Juelich (Germany); MR-Transfer e.K., Wuppertal (Germany); Langen, Karl-Josef; Kops, Elena Rota; Tellmann, Lutz; Stoffels, Gabriele; Weirich, Christoph; Filss, Christian; Scheins, Juergen; Herzog, Hans [Institute of Neuroscience and Medicine 4, INM 4, Juelich (Germany); Shah, N. Jon [Institute of Neuroscience and Medicine 4, INM 4, Juelich (Germany); RWTH Aachen University, Department of Neurology, Aachen (Germany); JARA-BRAIN-Translational Medicine, Aachen (Germany)

    2012-12-15

    The development of integrated magnetic resonance (MR)-positron emission tomography (PET) hybrid imaging opens up new horizons for imaging in neuro-oncology. In cerebral gliomas the definition of tumour extent may be difficult to ascertain using standard MR imaging (MRI) only. The differentiation of post-therapeutic scar tissue, tumour rests and tumour recurrence is challenging. The relationship to structures such as the pyramidal tract to the tumour mass influences the therapeutic neurosurgical approach. The diagnostic information may be enriched by sophisticated MR techniques such as diffusion tensor imaging (DTI), multiple-volume proton MR spectroscopic imaging (MRSI) and functional MRI (fMRI). Metabolic imaging with PET, especially using amino acid tracers such as {sup 18}F-fluoroethyl-l-tyrosine (FET) or {sup 11}C-l-methionine (MET) will indicate tumour extent and response to treatment. The new technologies comprising MR-PET hybrid systems have the advantage of providing comprehensive answers by a one-stop-job of 40-50 min. The combined approach provides data of different modalities using the same iso-centre, resulting in optimal spatial and temporal realignment. All images are acquired exactly under the same physiological conditions. We describe the imaging protocol in detail and provide patient examples for the different imaging modalities such as FET-PET, standard structural imaging (T1-weighted, T2-weighted, T1-weighted contrast agent enhanced), DTI, MRSI and fMRI. (orig.)

  9. Multimodal imaging utilising integrated MR-PET for human brain tumour assessment

    International Nuclear Information System (INIS)

    The development of integrated magnetic resonance (MR)-positron emission tomography (PET) hybrid imaging opens up new horizons for imaging in neuro-oncology. In cerebral gliomas the definition of tumour extent may be difficult to ascertain using standard MR imaging (MRI) only. The differentiation of post-therapeutic scar tissue, tumour rests and tumour recurrence is challenging. The relationship to structures such as the pyramidal tract to the tumour mass influences the therapeutic neurosurgical approach. The diagnostic information may be enriched by sophisticated MR techniques such as diffusion tensor imaging (DTI), multiple-volume proton MR spectroscopic imaging (MRSI) and functional MRI (fMRI). Metabolic imaging with PET, especially using amino acid tracers such as 18F-fluoroethyl-l-tyrosine (FET) or 11C-l-methionine (MET) will indicate tumour extent and response to treatment. The new technologies comprising MR-PET hybrid systems have the advantage of providing comprehensive answers by a one-stop-job of 40-50 min. The combined approach provides data of different modalities using the same iso-centre, resulting in optimal spatial and temporal realignment. All images are acquired exactly under the same physiological conditions. We describe the imaging protocol in detail and provide patient examples for the different imaging modalities such as FET-PET, standard structural imaging (T1-weighted, T2-weighted, T1-weighted contrast agent enhanced), DTI, MRSI and fMRI. (orig.)

  10. From yeast to human: exploring the comparative biology of methionine restriction in extending eukaryotic life span.

    Science.gov (United States)

    McIsaac, R Scott; Lewis, Kaitlyn N; Gibney, Patrick A; Buffenstein, Rochelle

    2016-01-01

    Methionine restriction is a widely reported intervention for increasing life span in several model organisms. Low circulating levels of methionine are evident in the long-lived naked mole-rat, suggesting that it naturally presents with a life-extending phenotype akin to that observed in methionine-restricted animals. Similarly, long-lived dwarf mice also appear to have altered methionine metabolism. The mechanisms underlying methionine-restriction effects on life-span extension, however, remain unknown, as do their potential connections with caloric restriction, another well-established intervention for prolonging life span. Paradoxically, methionine is enriched in proteins expressed in mitochondria and may itself serve an important role in the detoxification of reactive oxygen species and may thereby contribute to delayed aging. Collectively, we highlight the evidence that modulation of the methionine metabolic network can extend life span-from yeast to humans-and explore the evidence that sulfur amino acids and the concomitant transsulfuration pathway play a privileged role in this regard. However, systematic studies in single organisms (particularly those that exhibit extreme longevity) are still required to distinguish the fundamental principles concerning the role of methionine and other amino acids in regulating life span.

  11. A NOVEL S-ADENOSYL-L-METHIONINE: ARSENIC (III) METHYLTRANSFERASE FROM RAT LIVER CYTOSOL

    Science.gov (United States)

    A Novel S-Adenosyl-L-methionine: Arsenic(III) Methyltransferase from Rat Liver CytosolShan Lin, Qing Shi, F. Brent Nix, Miroslav Styblo, Melinda A. Beck, Karen M. Herbin-Davis, Larry L. Hall, Josef B. Simeonsson, and David J. Thomas S-adenosyl-L-methionine (AdoMet): ar...

  12. Comparison of the sustainability metrics of the petrochemical and biomass-based routes to methionine

    NARCIS (Netherlands)

    Sanders, J.P.M.; Sheldon, R.A.

    2015-01-01

    Sustainability metrics, based on material efficiency, energy input, land use and costs, of three processesfor the manufacture of methionine are compared. The petrochemical process affords dl-methionine whilethe two biomass-based routes afford the l-enantiomer. From the point of view of the major

  13. Thermodynamics of the dissolution of crystalline L-methionine in water

    Science.gov (United States)

    Lytkin, A. I.; Chernikov, V. V.; Krutova, O. N.; Damrina, K. V.; Skvortsov, I. A.

    2016-05-01

    The enthalpies of dissolution of crystalline L-methionine in water and aqueous solutions of potasium hydroxide at 298.15 K are measured by means of direct calorimetry. The standard enthalpies of formation are calculated for L-methionine and products of its dissociation in aqueous solution.

  14. Interactive effects of selenium, methionine, and dietary protein on survival, growth, and physiology in mallard ducklings

    Science.gov (United States)

    Hoffman, D.J.; Sanderson, C.J.; LeCaptain, L.J.; Cromartie, E.; Pendleton, G.W.

    1992-01-01

    Concentrations of over 100 ppm (100 mg/kg) selenium (Se) have been found in aquatic food chains associated with irrigation drainwater. Both quantity and composition of dietary protein for wild ducklings may vary in selenium-contaminated environments. Day-old mallard (Anas platyrhynchos) ducklings received one of the following diets containing 22% protein: unsupplemented (controls), 15 ppm Se (as selenomethionine), 60 ppm Se, methionine supplemented, 15 ppm Se with methionine supplement, or 60 ppm Se with methionine supplement. In a second concurrent experiment the above sequence was repeated with a protein-restricted (11%) but isocaloric diet. In a third concurrent experiment all ducklings received 44% protein with 0, 15, or 60 ppm Se added. After 4 weeks, blood and tissue samples were collected for biochemical and histological examination. With 22% protein and 60 ppm Se in the diet, duckling survival and growth was reduced and histopathological lesions of the liver occurred. Antagonistic interactive effects occurred between supplementary methionine and Se, including complete to partial alleviation of the following Se effects by methionine: mortality, hepatic lesions, and altered glutathione and thiol status. With 11% protein, growth of controls was less than that with 22% protein, Se (60 ppm) caused 100% mortality, and methionine supplementation, although protective afforded less protection than it did with 22% protein. With 44% protein, ducklings experienced physiological stress, and Se was more toxic than with methionine-supplemented 22% protein. These findings suggest the potential for antagonistic effects of Se, methionine, and protein on duckling survival and physiology.

  15. Cost-effectiveness of PET and PET/Computed Tomography

    DEFF Research Database (Denmark)

    Gerke, Oke; Hermansson, Ronnie; Hess, Søren;

    2015-01-01

    measure by means of incremental cost-effectiveness ratios when considering the replacement of the standard regimen by a new diagnostic procedure. This article discusses economic assessments of PET and PET/computed tomography reported until mid-July 2014. Forty-seven studies on cancer and noncancer...

  16. Downregulation of Cdc6 and pre-replication complexes in response to methionine stress in breast cancer cells

    OpenAIRE

    Booher, Keith; Lin, Da-Wei; Borrego, Stacey L.; Kaiser, Peter

    2012-01-01

    Methionine and homocysteine are metabolites in the transmethylation pathway leading to synthesis of the methyl-donor S-adenosylmethionine (SAM). Most cancer cells stop proliferating during methionine stress conditions, when methionine is replaced in the growth media by its immediate metabolic precursor homocysteine (Met-Hcy+). Non-transformed cells proliferate in Met-Hcy+ media, making the methionine metabolic requirement of cancer cells an attractive target for therapy, yet there is relative...

  17. Thioredoxin-dependent Redox Regulation of Cellular Signaling and Stress Response through Reversible Oxidation of Methionines

    Energy Technology Data Exchange (ETDEWEB)

    Bigelow, Diana J.; Squier, Thomas C.

    2011-06-01

    Generation of reactive oxygen species (ROS) is a common feature of many forms of stress to which plants are exposed. Successful adaptation to changing environmental conditions requires sensitive sensors of ROS such as protein-bound methionines that are converted to their corresponding methionine sulfoxides, which in turn can influence cellular signaling pathways. Such a signaling protein is calmodulin, which represents an early and central point in calcium signaling pathways important to stress response in plants. We describe recent work elucidating fundamental mechanisms of reversible methionine oxidation within calmodulin, including the sensitivity of individual methionines within plant and animal calmodulin to ROS, the structural and functional consequences of their oxidation, and the interactions of oxidized calmodulin with methionine sulfoxide reductase enzymes.

  18. Therapeutic tumor-specific cell cycle block induced by methionine starvation in vivo.

    Science.gov (United States)

    Guo, H; Lishko, V K; Herrera, H; Groce, A; Kubota, T; Hoffman, R M

    1993-12-01

    The ability to induce a specific cell cycle block selectively in the tumor could have many uses in chemotherapy. In the present study we have achieved this goal of inducing a tumor-specific cell cycle block in vivo by depriving Yoshida sarcoma-bearing nude mice of dietary methionine. Further, we demonstrate that methionine depletion also causes the tumor to eventually regress. The antitumor effect of methionine depletion resulted in the extended survival of the tumor-bearing mice. The mice on the methionine-deprived diets maintained their body weight for the time period studied, indicating that tumor regression was not a function of body weight loss. The data reported here support future experiments utilizing methionine depletion as a target for tumor-selective cell cycle-dependent therapy.

  19. Methionine uptake in Corynebacterium glutamicum by MetQNI and by MetPS, a novel methionine and alanine importer of the NSS neurotransmitter transporter family.

    Science.gov (United States)

    Trötschel, Christian; Follmann, Martin; Nettekoven, Jeannine A; Mohrbach, Tobias; Forrest, Lucy R; Burkovski, Andreas; Marin, Kay; Krämer, Reinhard

    2008-12-01

    The soil bacterium Corynebacterium glutamicum is a model organism in amino acid biotechnology. Here we present the identification of two different L-methionine uptake systems including the first characterization of a bacterial secondary methionine carrier. The primary carrier MetQNI is a high affinity ABC-type transporter specific for l-methionine. Its expression is under the control of the transcription factor McbR, the global regulator of sulfur metabolism in C. glutamicum. Besides MetQNI, a novel secondary methionine uptake system of the NSS (neurotransmitter:sodium symporter) family was identified and named MetP. The MetP system is characterized by a lower affinity for methionine and uses Na(+) ions for energetic coupling. It is also the main alanine transporter in C. glutamicum and is expressed constitutively. These observations are consistent with models of methionine, alanine, and leucine bound to MetP, derived from the X-ray crystal structure of the LeuT transporter from Aquifex aeolicus. Complementation studies show that MetP consists of two components, a large subunit with 12 predicted transmembrane segments and, surprisingly, an additional subunit with one predicted transmembrane segment only. Thus, this new member of the NSS transporter family adds a novel feature to this class of carriers, namely, the functional dependence on an additional small subunit.

  20. Increasing levels of dietary crystalline methionine affect plasma methionine profiles, ammonia excretion, and the expression of genes related to the hepatic intermediary metabolism in rainbow trout (Oncorhynchus mykiss).

    Science.gov (United States)

    Rolland, Marine; Skov, Peter V; Larsen, Bodil K; Holm, Jørgen; Gómez-Requeni, Pedro; Dalsgaard, Johanne

    2016-08-01

    Strictly carnivorous fish with high requirements for dietary protein, such as rainbow trout (Oncorhynchus mykiss) are interesting models for studying the role of amino acids as key regulators of intermediary metabolism. Methionine is an essential amino acid for rainbow trout, and works as a signalling factor in different metabolic pathways. The study investigated the effect of increasing dietary methionine intake on the intermediary metabolism in the liver of juvenile rainbow trout. For this purpose, five diets were formulated with increasing methionine levels from 0.60 to 1.29% dry matter. The diets were fed in excess for six weeks before three sampling campaigns carried out successively to elucidate (i) the hepatic expression of selected genes involved in lipid, glucose and amino acid metabolism; (ii) the postprandial ammonia excretion; and (iii) the postprandial plasma methionine concentrations. The transcript levels of enzymes involved in lipid metabolism (fatty acid synthase, glucose 6 phosphate dehydrogenase and carnitine palmitoyl transferase 1 a), gluconeogenesis (fructose-1,6-biphosphatase) and amino acid catabolism (alanine amino transferase and glutamate dehydrogenase) were significantly affected by the increase in dietary methionine. Changes in gene expression reflected to some extent the decrease in ammonia excretion (P=0.022) and in the hepatosomatic index (HSI; Ptrout responded in a dose-dependent manner to increasing levels of dietary methionine. PMID:27105833

  1. Peptide backbone cleavage by α-amidation is enhanced at methionine residues.

    Science.gov (United States)

    Hellwig, Michael; Löbmann, Katja; Orywol, Tom

    2015-01-01

    Cleavage reactions at backbone loci are one of the consequences of oxidation of proteins and peptides. During α-amidation, the Cα -N bond in the backbone is cleaved under formation of an N-terminal peptide amide and a C-terminal keto acyl peptide. On the basis of earlier works, a facilitation of α-amidation by the thioether group of adjacent methionine side chains was proposed. This reaction was characterized by using benzoyl methionine and benzoyl alanyl methionine as peptide models. The decomposition of benzoylated amino acids (benzoyl-methionine, benzoyl-alanine, and benzoyl-methionine sulfoxide) to benzamide in the presence of different carbohydrate compounds (reducing sugars, Amadori products, and reductones) was studied during incubation for up to 48 h at 80 °C in acetate-buffered solution (pH 6.0). Small amounts of benzamide (0.3-1.5 mol%) were formed in the presence of all sugars and from all benzoylated species. However, benzamide formation was strongly enhanced, when benzoyl methionine was incubated in the presence of reductones and Amadori compounds (3.5-4.2 mol%). The reaction was found to be intramolecular, because α-amidation of a similar 4-methylbenzoylated amino acid was not enhanced in the presence of benzoyl-methionine and carbohydrate compounds. In the peptide benzoyl-alanyl-methionine, α-amidation at the methionine residue is preferred over α-amidation at the benzoyl peptide bond. We propose here a mechanism for the enhancement of α-amidation at methionine residues.

  2. [Effects of L-methionine on nitrification and N2O emission in subtropical forest soil].

    Science.gov (United States)

    Lin, Wei; Pei, Guang-ting; Ma, Hong-liang; Gao, Ren; Yin, Yun-feng; Peng, Yuan-zhen

    2015-09-01

    The objective of this study was to investigate the influence of L-methionine on nitrification and nitrous oxide emission in a red soil under laboratory incubation experiments. A subtropical broad-leaved forest soil sample was collected from Wanmulin natural reserve in Fujian Province, Southeast China. Five treatments were carried out with three replications, i. e., control (CK), L- methionine addition (M), L-methionine and NH(4+)-N addition (MA), L-methionine and NO(2-)-N addition (MN), L-methionine and glucose addition (MC). The soil moisture was maintained at 60% WHC or 90% WHC. The results indicated that the soil NH(4+)-N content in the M treatment significantly increased by 0.8%-61.3%, while the soil NO(3-)-N content reduced by 13.2%-40.7% compared with CK. Under 60% WHC condition, soil NO(2-)-N content in the MC treatment was higher than in the M treatment, soil NO(3-)-N content in the MA and MN treatments were greater than that in the M treatment, and greater in the MN treatment than in the MA treatment. The soil NO(3-)-N content was lowest in the M treatment after incubation. These results suggested that L-methionine could inhibit nitrosation process of autotrophic nitrification. To some extent, carbon addition as glucose with L-methionine decreased the NH(4+)-N content, inhibited the autotrophic nitrification and their effects were dependent on water level. Under 90% WHC condition, carbon addition improved denitrification more obviously, but the decrease of NO(3-)-N content was not sufficient to prove the inhibition of hetero-nitrification due to carbon addition in the presence of L-methionine. The nitrous oxide emission from soil was increased by L-methionine addition. Compared with 60% WHC condition, the nitrous oxide emission was higher under 90% WHC condition, and the promotion of L-methionine addition on N2O was greater when glucose added.

  3. [Effects of L-methionine on nitrification and N2O emission in subtropical forest soil].

    Science.gov (United States)

    Lin, Wei; Pei, Guang-ting; Ma, Hong-liang; Gao, Ren; Yin, Yun-feng; Peng, Yuan-zhen

    2015-09-01

    The objective of this study was to investigate the influence of L-methionine on nitrification and nitrous oxide emission in a red soil under laboratory incubation experiments. A subtropical broad-leaved forest soil sample was collected from Wanmulin natural reserve in Fujian Province, Southeast China. Five treatments were carried out with three replications, i. e., control (CK), L- methionine addition (M), L-methionine and NH(4+)-N addition (MA), L-methionine and NO(2-)-N addition (MN), L-methionine and glucose addition (MC). The soil moisture was maintained at 60% WHC or 90% WHC. The results indicated that the soil NH(4+)-N content in the M treatment significantly increased by 0.8%-61.3%, while the soil NO(3-)-N content reduced by 13.2%-40.7% compared with CK. Under 60% WHC condition, soil NO(2-)-N content in the MC treatment was higher than in the M treatment, soil NO(3-)-N content in the MA and MN treatments were greater than that in the M treatment, and greater in the MN treatment than in the MA treatment. The soil NO(3-)-N content was lowest in the M treatment after incubation. These results suggested that L-methionine could inhibit nitrosation process of autotrophic nitrification. To some extent, carbon addition as glucose with L-methionine decreased the NH(4+)-N content, inhibited the autotrophic nitrification and their effects were dependent on water level. Under 90% WHC condition, carbon addition improved denitrification more obviously, but the decrease of NO(3-)-N content was not sufficient to prove the inhibition of hetero-nitrification due to carbon addition in the presence of L-methionine. The nitrous oxide emission from soil was increased by L-methionine addition. Compared with 60% WHC condition, the nitrous oxide emission was higher under 90% WHC condition, and the promotion of L-methionine addition on N2O was greater when glucose added. PMID:26785545

  4. Neurotransmission imaging by PET

    Energy Technology Data Exchange (ETDEWEB)

    Takano, Akihiro; Suhara, Tetsuya [National Inst. of Radiological Sciences, Chiba (Japan)

    2001-08-01

    PET studies on neurotransmission in psychological disorders to evaluate abnormal neurotransmission and therapeutic effects are thoroughly reviewed by type of major neurotransmitters. Studies on dopaminergic neurotransmission have focused on the function of dopamine D{sub 2} receptors, receptor subtypes, such as the D{sub 1} receptor, and ligands, such as transporters. PET studies of dopamine D{sub 2} receptor, which began in the early 1980s, have predominantly been performed in schizophrenia, and most have failed to detect any statistically significant differences between schizophrenia patients and controls. The studies in the early 1980s were performed by using [{sup 11}C]N-methyl-spiperone (NMSP) and [{sup 11}C]raclopride, ligands for striatal dopamine D{sub 2} receptors. [{sup 11}C]FLB457, which has much higher affinity for D{sub 2} receptors than raclopride, began to be used in the 1990s. Dopamine D{sub 2} occupancy after drug ingestion has also been investigated to clarify the mechanisms and effects of antipsychotic drugs, and there have also been studies on the effect of aging and personality traits on dopamine D{sub 2} receptor levels in healthy subjects. In studies on dopamine receptor subtypes other than D{sub 2}, dopamine D{sub 1} receptors have been studied in connection with assessments of cognitive functions. Most studies on dopamine transporters have been related to drug dependence. Serotonin 5-HT{sub 2A} receptors have been studied with [{sup 11}C]NMSP in schizophrenia patients, while studies of another serotonin receptor subtype, 5-HT{sub 1A} receptors, have been mainly conducted in patients with depression. [{sup 11}C]NMSP PET showed no difference between schizophrenia patients who had not undergone phamacotherapy and normal subjects. Because serotonin selective reuptake inhibitors (SSRIs) affect serotonin transporters, and abnormalities in serotonin transporters detected in mood disorders, PET ligands for serotonin transporters have increasingly

  5. Get Set for a Pet.

    Science.gov (United States)

    DeRosa, Bill

    1987-01-01

    Describes a game in which students deal with some of the factors involved in being a responsible pet owner. Includes a list of the materials needed for the game and provides the game board and the game pieces, along with a fold-out poster about neutering and spaying pets. (TW)

  6. Welfare assessment in pet rabbits

    NARCIS (Netherlands)

    Schepers, F.; Koene, P.; Beerda, B.

    2009-01-01

    One million pet rabbits are kept in The Netherlands, but there are no data available on their behaviour and welfare. This study seeks to assess the welfare of pet rabbits in Dutch households and is a first step in the development of a welfare assessment system. In an internet survey, housing systems

  7. Use of PET Imaging to Evaluate Transporter-Mediated Drug-Drug Interactions.

    Science.gov (United States)

    Langer, Oliver

    2016-07-01

    Several membrane transporters belonging to the adenosine triphosphate-binding cassette (ABC) and solute carrier (SLC) families can transport drugs and drug metabolites and thereby exert an effect on drug absorption, distribution, and excretion, which may potentially lead to transporter-mediated drug-drug interactions (DDIs). Some transporter-mediated DDIs may lead to changes in organ distribution of drugs (eg, brain, liver, kidneys) without affecting plasma concentrations. Positron emission tomography (PET) is a noninvasive imaging method that allows studying of the distribution of radiolabeled drugs to different organs and tissues and is therefore the method of choice to quantitatively assess transporter-mediated DDIs on a tissue level. There are 2 approaches to how PET can be used in transporter-mediated DDI studies. When the drug of interest is a potential perpetrator of DDIs, it may be administered in unlabeled form to assess its influence on tissue distribution of a generic transporter-specific PET tracer (probe substrate). When the drug of interest is a potential victim of DDIs, it may be radiolabeled with carbon-11 or fluorine-18 and used in combination with a prototypical transporter inhibitor (eg, rifampicin). PET has already been used both in preclinical species and in humans to assess the effects of transporter-mediated DDIs on drug disposition in different organ systems, such as brain, liver, and kidneys, for which examples are given in the present review article. Given the growing importance of membrane transporters with respect to drug safety and efficacy, PET is expected to play an increasingly important role in future drug development. PMID:27385172

  8. Ligands for SPECT and PET imaging of muscarinic-cholinergic receptors of the heart and brain

    Energy Technology Data Exchange (ETDEWEB)

    Knapp, F.F. Jr.; McPherson, D.W.; Luo, H. [and others

    1995-06-01

    Interest in the potential use of cerebral SPECT and PET imaging for determination of the density and activity of muscarinic-cholinergic receptors (mAChR) has been stimulated by the changes in these receptors which occur in many neurological diseases. In addition, the important involvement of mAChR in modulating negative inotropic cardiac activity suggests that such receptor ligands may have important applications in evaluation of changes which may occur in cardiac disease. In this paper, the properties of several key muscarinic receptor ligands being developed or which have been used for clinical SPECT and PET are discussed. In addition, the ORNL development of the new iodinated IQNP ligand based on QNB and the results of in vivo biodistribution studies in rats, in vitro competitive binding studies and ex vivo autoradiographic experiments are described. The use of radioiodinated IQNP may offer several advantages in comparison to IQNB because of its easy and high yield preparation and high brain uptake and the potential usefulness of the {open_quotes}partial{close_quotes} subtype selective IONP isomers. We also describe the development of new IQNP-type analogues which offer the opportunity for radiolabeling with positron-emitting radioisotopes (carbon-11, fluorine-18 and bromine-76) for potential use with PET.

  9. Neuropsychiatry: PET and SPECT

    International Nuclear Information System (INIS)

    Functional brain imaging with PET and SPECT have a definitive and well established role in the investigation of a variety of conditions such as dementia, epilepsy and drug addiction. With these methods it is possible to detect early rCBF (regional Cerebral Blood Flow) changes seen in dementia (even before clinical symptoms) and differentiate Alzheimer's disease from other dementias by means of the rCBF pattern change. 18-F-FDG PET imaging is a useful tool in partial epilepsy because both rCBF and brain metabolism are compromised at the epileptogenic focus. During the seizure, rCBF dramatically increases locally. Using SPECT it is possible to locate such foci with 97% accuracy. In drug addiction, particularly with cocaine, functional imaging has proven to be very sensitive to detect brain flow and metabolism derangement early in the course of this condition. These findings are important in many ways: prognostic value, they are used as a powerful reinforcement tool and to monitor functional recovery with rehabilitation. There are many other conditions in which functional brain imaging is of importance such as acute stroke treatment assessment, trauma rehabilitation and in psychiatric and abnormal movement diseases specially with the development of receptor imaging (au)

  10. FDG PET imaging dementia

    International Nuclear Information System (INIS)

    Dementia is a major burden for many countries including South Korea, where life expectancy is continuously growing and the proportion of aged people is rapidly growing. Neurodegenerative disorders, such as, Alzheimer disease, dementia with Lewy bodies, frontotemporal dementia. Parkinson disease, progressive supranuclear palsy, corticobasal degeneration, Huntington disease, can cause dementia, and cerebrovascular disease also can cause dementia. Depression or hypothyroidism also can cause cognitive deficits, but they are reversible by management of underlying cause unlike the forementioned dementias. Therefore these are called pseudodementia. We are entering an era of dementia care that will be based upon the identification of potentially modifiable risk factors and early disease markers, and the application of new drugs postpone progression of dementias or target specific proteins that cause dementia. Efficient pharmacologic treatment of dementia needs not only to distinguish underlying causes of dementia but also to be installed as soon as possible. Therefore, differential diagnosis and early diagnosis of dementia are utmost importance. F-18 FDG PET is useful for clarifying dementing diseases and is also useful for early detection of the disease. Purpose of this article is to review the current value of FDG PET for dementing diseases including differential diagnosis of dementia and prediction of evolving dementia

  11. FDG PET imaging dementia

    Energy Technology Data Exchange (ETDEWEB)

    Ahn, Byeong Cheol [Kyungpook National University Medical School and Kyungpook National University Hospital, Daegu (Korea, Republic of)

    2007-04-15

    Dementia is a major burden for many countries including South Korea, where life expectancy is continuously growing and the proportion of aged people is rapidly growing. Neurodegenerative disorders, such as, Alzheimer disease, dementia with Lewy bodies, frontotemporal dementia. Parkinson disease, progressive supranuclear palsy, corticobasal degeneration, Huntington disease, can cause dementia, and cerebrovascular disease also can cause dementia. Depression or hypothyroidism also can cause cognitive deficits, but they are reversible by management of underlying cause unlike the forementioned dementias. Therefore these are called pseudodementia. We are entering an era of dementia care that will be based upon the identification of potentially modifiable risk factors and early disease markers, and the application of new drugs postpone progression of dementias or target specific proteins that cause dementia. Efficient pharmacologic treatment of dementia needs not only to distinguish underlying causes of dementia but also to be installed as soon as possible. Therefore, differential diagnosis and early diagnosis of dementia are utmost importance. F-18 FDG PET is useful for clarifying dementing diseases and is also useful for early detection of the disease. Purpose of this article is to review the current value of FDG PET for dementing diseases including differential diagnosis of dementia and prediction of evolving dementia.

  12. Sulfur amino acids and atherosclerosis: a role for excess dietary methionine.

    Science.gov (United States)

    Selhub, Jacob; Troen, Aron M

    2016-01-01

    The homocysteine theory of arteriosclerosis received credence when it was shown that after a methionine load, circulating homocysteine-cysteine concentrations were higher in cardiovascular disease patients than in healthy controls. Subsequent studies showing associations between homocysteine and coronary artery disease, stroke and cognitive impairment, relied on small increases in homocysteine concentration unlike the very high homocysteine seen in the rare genetic disorders that lead to homocystinuria and much higher homocysteine levels. Subsequent studies in cell culture, animals, and humans showed that a variety of cardiovascular adverse effects of "high homocysteine" introduced either as a nonphysiological bolus or as a methionine load led to high homocysteine. We fed apolipoprotein E-deficient mice diets designed to achieve three conditions: (1) high methionine intake with normal blood homocysteine, (2) high methionine intake with B vitamin deficiency and hyperhomocysteinemia, and (3) normal methionine intake with both B vitamin deficiency and hyperhomocysteinemia. We found that the mice fed methionine-rich diets had significant atheromatous pathology in the aortic arch even with normal plasma homocysteine levels. Mice fed B vitamin-deficient diets developed severe hyperhomocysteinemia but without any increase in vascular pathology. Our findings suggest that even moderate increases in methionine intake are atherogenic in susceptible mice while high plasma homocysteine is not.

  13. Growth hormone signaling is necessary for lifespan extension by dietary methionine.

    Science.gov (United States)

    Brown-Borg, Holly M; Rakoczy, Sharlene G; Wonderlich, Joseph A; Rojanathammanee, Lalida; Kopchick, John J; Armstrong, Vanessa; Raasakka, Debbie

    2014-12-01

    Growth hormone significantly impacts lifespan in mammals. Mouse longevity is extended when growth hormone (GH) signaling is interrupted but markedly shortened with high-plasma hormone levels. Methionine metabolism is enhanced in growth hormone deficiency, for example, in the Ames dwarf, but suppressed in GH transgenic mice. Methionine intake affects also lifespan, and thus, GH mutant mice and respective wild-type littermates were fed 0.16%, 0.43%, or 1.3% methionine to evaluate the interaction between hormone status and methionine. All wild-type and GH transgenic mice lived longer when fed 0.16% methionine but not when fed higher levels. In contrast, animals without growth hormone signaling due to hormone deficiency or resistance did not respond to altered levels of methionine in terms of lifespan, body weight, or food consumption. Taken together, our results suggest that the presence of growth hormone is necessary to sense dietary methionine changes, thus strongly linking growth and lifespan to amino acid availability.

  14. Methionine protects against hyperthermia-induced cell injury in cultured bovine mammary epithelial cells.

    Science.gov (United States)

    Han, Zhao-Yu; Mu, Tian; Yang, Zhen

    2015-01-01

    The aim of this study was to investigate the effects of methionine on cell proliferation, antioxidant activity, apoptosis, the expression levels of related genes (HSF-1, HSP70, Bax and Bcl-2) and the expression levels of protein (HSP70) in mammary epithelial cells, after heat treatment. Methionine (60 mg/L) increased the viability and attenuated morphological damage in hyperthermia-treated bovine mammary epithelial cells (BMECs). Additionally, methionine significantly reduced lactate dehydrogenase leakage, malondialdehyde formation, nitric oxide, and nitric oxide synthase activity. Superoxide dismutase, catalase, and glutathione peroxidase enzymatic activity was increased significantly in the presence of methionine. Bovine mammary epithelial cells also exhibited a certain amount of HSP70 reserve after methionine pretreatment for 24 h, and the expression level of the HSP70 gene and protein further increased with incubation at 42 °C for 30 min. Compared to the control, the expression of HSF-1 mRNA increased, and there was a significantly reduced expression of Bax/Bcl-2 mRNA and a reduced activity of caspase-3 against heat stress. Methionine also increased survival and decreased early apoptosis of hyperthermia-treated BMECs. Thus, methionine has cytoprotective effects on hyperthermia-induced damage in BMECs.

  15. Sulphur Atoms from Methionines Interacting with Aromatic Residues Are Less Prone to Oxidation

    Science.gov (United States)

    Aledo, Juan C.; Cantón, Francisco R.; Veredas, Francisco J.

    2015-11-01

    Methionine residues exhibit different degrees of susceptibility to oxidation. Although solvent accessibility is a relevant factor, oxidation at particular sites cannot be unequivocally explained by accessibility alone. To explore other possible structural determinants, we assembled different sets of oxidation-sensitive and oxidation-resistant methionines contained in human proteins. Comparisons of the proteins containing oxidized methionines with all proteins in the human proteome led to the conclusion that the former exhibit a significantly higher mean value of methionine content than the latter. Within a given protein, an examination of the sequence surrounding the non-oxidized methionine revealed a preference for neighbouring tyrosine and tryptophan residues, but not for phenylalanine residues. However, because the interaction between sulphur atoms and aromatic residues has been reported to be important for the stabilization of protein structure, we carried out an analysis of the spatial interatomic distances between methionines and aromatic residues, including phenylalanine. The results of these analyses uncovered a new determinant for methionine oxidation: the S-aromatic motif, which decreases the reactivity of the involved sulphur towards oxidants.

  16. PET-Based Thoracic Radiation Oncology.

    Science.gov (United States)

    Simone, Charles B; Houshmand, Sina; Kalbasi, Anusha; Salavati, Ali; Alavi, Abass

    2016-07-01

    Fluorodeoxyglucose-PET is increasingly being integrated into multiple aspects of oncology. PET/computed tomography (PET/CT) has become especially important in radiation oncology. With the increasing use of advanced techniques like intensity-modulated radiation therapy and proton therapy, PET/CT scans have played critical roles in the target delineation of tumors for radiation oncologists delivering conformal treatment techniques. Use of PET/CT is well established in lung cancer and several other thoracic malignancies. This article details the current uses of PET/CT in thoracic radiation oncology with a focus on lung cancer and describes expected future roles of PET/CT for thoracic tumors.

  17. Methionine restriction fundamentally supports health by tightening epithelial barriers.

    Science.gov (United States)

    Mullin, James M; Skrovanek, Sonja M; Ramalingam, Arivudainambi; DiGuilio, Katherine M; Valenzano, Mary C

    2016-01-01

    Dietary methionine restriction (MR) has been found to affect one of the most primary tissue-level functions of an organism: the efficiency with which the epithelial linings of major organs separate the fluid compartments that they border. This process, epithelial barrier function, is basic for proper function of all organs, including the lung, liver, gastrointestinal tract, reproductive tract, blood-brain barrier, and kidney. Specifically, MR has been found to modify the protein composition of tight junctional complexes surrounding individual epithelial cells in a manner that renders the complexes less leaky. This has been observed in both a renal epithelial cell culture model and in gastrointestinal tissue. In both cases, MR increased the transepithelial electrical resistance across the epithelium, while decreasing passive leak of small nonelectrolytes. However, the specific target protein modifications involved were unique to each case. Overall, this provides an example of the primary level on which MR functions to modify, and improve, an organism.

  18. Refolding and characterization of methionine adenosyltransferase from Euglena gracilis.

    Science.gov (United States)

    Garrido, Francisco; Estrela, Sylvie; Alves, Claudia; Sánchez-Pérez, Gabino F; Sillero, Antonio; Pajares, María A

    2011-09-01

    Methionine adenosyltransferase from Euglena gracilis (MATX) is a recently discovered member of the MAT family of proteins that synthesize S-adenosylmethionine. Heterologous overexpression of MATX in Escherichia coli rendered the protein mostly in inclusion bodies under all conditions tested. Therefore, a refolding and purification procedure from these aggregates was developed to characterize the enzyme. Maximal recovery was obtained using inclusion bodies devoid of extraneous proteins by washing under mild urea (2M) and detergent (5%) concentrations. Refolding was achieved in two steps following solubilization in the presence of Mg(2+); chaotrope dilution to UV circular dichroism revealed β-sheet and random coil as the main secondary structure elements of the protein. The high level of sequence conservation allowed construction of a structural model that preserved the main features of the MAT family, the major changes involving the N-terminal domain.

  19. Methionine enkephalin, its role in immunoregulation and cancer therapy.

    Science.gov (United States)

    Zhao, Dingliang; Plotnikoff, Nicolas; Griffin, Noreen; Song, Tao; Shan, Fengping

    2016-08-01

    Methionine enkephalin (MENK), an endogenous neuropeptide has a crucial role in both neuroendocrine and immune systems. MENK is believed to have an immunoregulatory activity to have cancer biotherapy activity by binding to the opioid receptors on immune and cancer cells. Clinical trial studies in cancer patients have shown that MENK activates immune cells directly and by inhibiting regulatory T-cells (Tregs). MENK may also change the tumor microenvironment by binding to opioid receptor on or in cancer cells. All of these mechanisms of action have biologic significance and potential for use in cancer immunotherapy. Furthermore, they reveal a relationship between the endocrine and immune systems. Due to the apparent role of MENK in cancer therapy we reviewed herein, the research undertaken with MENK in recent years; which has advanced our understanding of the role MENK has in cancer progression and its relationship to immunity, supporting MENK as a new strategy for cancer immunotherapy. PMID:26927200

  20. Methionine enkephalin, its role in immunoregulation and cancer therapy.

    Science.gov (United States)

    Zhao, Dingliang; Plotnikoff, Nicolas; Griffin, Noreen; Song, Tao; Shan, Fengping

    2016-08-01

    Methionine enkephalin (MENK), an endogenous neuropeptide has a crucial role in both neuroendocrine and immune systems. MENK is believed to have an immunoregulatory activity to have cancer biotherapy activity by binding to the opioid receptors on immune and cancer cells. Clinical trial studies in cancer patients have shown that MENK activates immune cells directly and by inhibiting regulatory T-cells (Tregs). MENK may also change the tumor microenvironment by binding to opioid receptor on or in cancer cells. All of these mechanisms of action have biologic significance and potential for use in cancer immunotherapy. Furthermore, they reveal a relationship between the endocrine and immune systems. Due to the apparent role of MENK in cancer therapy we reviewed herein, the research undertaken with MENK in recent years; which has advanced our understanding of the role MENK has in cancer progression and its relationship to immunity, supporting MENK as a new strategy for cancer immunotherapy.

  1. Formation of methionine sulfoxide during glycoxidation and lipoxidation of ribonuclease A.

    Science.gov (United States)

    Brock, Jonathan W C; Ames, Jennifer M; Thorpe, Suzanne R; Baynes, John W

    2007-01-15

    Chemical modification of proteins by reactive oxygen species affects protein structure, function and turnover during aging and chronic disease. Some of this damage is direct, for example by oxidation of amino acids in protein by peroxide or other reactive oxygen species, but autoxidation of ambient carbohydrates and lipids amplifies both the oxidative and chemical damage to protein and leads to formation of advanced glycoxidation and lipoxidation end-products (AGE/ALEs). In previous work, we have observed the oxidation of methionine during glycoxidation and lipoxidation reactions, and in the present work we set out to determine if methionine sulfoxide (MetSO) in protein was a more sensitive indicator of glycoxidative and lipoxidative damage than AGE/ALEs. We also investigated the sites of methionine oxidation in a model protein, ribonuclease A (RNase), in order to determine whether analysis of the site specificity of methionine oxidation in proteins could be used to indicate the source of the oxidative damage, i.e. carbohydrate or lipid. We describe here the development of an LC/MS/MS for quantification of methionine oxidation at specific sites in RNase during glycoxidation or lipoxidation by glucose or arachidonate, respectively. Glycoxidized and lipoxidized RNase were analyzed by tryptic digestion, followed by reversed phase HPLC and mass spectrometric analysis to quantify methionine and methionine sulfoxide containing peptides. We observed that: (1) compared to AGE/ALEs, methionine sulfoxide was a more sensitive biomarker of glycoxidative or lipoxidative damage to proteins; (2) regardless of oxidizable substrate, the relative rate of oxidation of methionine residues in RNase was Met29>Met30>Met13, with Met79 being resistant to oxidation; and (3) arachidonate produced a significantly greater yield of MetSO, compared to glucose. The methods developed here should be useful for assessing a protein's overall exposure to oxidative stress from a variety of sources in

  2. Effects of Glycine, Water, Ammonia, and Ammonium Bicarbonate on the Oligomerization of Methionine

    Science.gov (United States)

    Huang, Rui; Furukawa, Yoshihiro; Otake, Tsubasa; Kakegawa, Takeshi

    2016-09-01

    The abiotic oligomerization of amino acids may have created primordial, protein-like biological catalysts on the early Earth. Previous studies have proposed and evaluated the potential of diagenesis for the amino acid oligomerization, simulating the formation of peptides that include glycine, alanine, and valine, separately. However, whether such conditions can promote the formation of peptides composed of multiple amino acids remains unclear. Furthermore, the chemistry of pore water in sediments should affect the oligomerization and degradation of amino acids and oligomers, but these effects have not been studied extensively. In this study, we investigated the effects of water, ammonia, ammonium bicarbonate, pH, and glycine on the oligomerization and degradation of methionine under high pressure (150 MPa) and high temperature conditions (175 °C) for 96 h. Methionine is more difficult to oligomerize than glycine and methionine dimer was formed in the incubation of dry powder of methionine. Methionine oligomers as long as trimers, as well as methionylglycine and glycylmethionine, were formed under every condition with these additional compounds. Among the compounds tested, the oligomerization reaction rate was accelerated by the presence of water and by an increase in pH. Ammonia also increased the oligomerization rate but consumed methionine by side reactions and resulted in the rapid degradation of methionine and its peptides. Similarly, glycine accelerated the oligomerization rate of methionine and the degradation of methionine, producing water, ammonia, and bicarbonate through its decomposition. With Gly, heterogeneous dimers (methionylglycine and glycylmethionine) were formed in greater amounts than with other additional compounds although smaller amount of these heterogeneous dimers were formed with other additional compounds. These results suggest that accelerated reaction rates induced by water and co-existing reactive compounds promote the oligomerization

  3. Dietary Supplementation of Alternative Methionine and Choline Sources in the Organic Broiler Production in Brazil

    Directory of Open Access Journals (Sweden)

    LC Demattê Filho

    2015-12-01

    Full Text Available ABSTRACT The objective of this study was to evaluate the use of natural and alternative sources of methionine and choline which can be allowed to use in organic livestock systems to feed broilers produced in Brazil. Seven hundred and twenty one-d-old male Cobb broilers were randomly allocated to four treatments with six replicates of 24 birds each. The treatments consisted in substituting the commonly used DL-methionine 99% by a vegetable source of methionine and cholinechloride 60% by alternative source of choline in the form of phosphatidylcholine. The following treatments were evaluated: I feed with DL-methionine 99% and choline chloride 60%, II feed with an vegetable methionine source and choline chloride 60%, III feed with DL-methionine 99% and choline as phosphatidylcholine, and IV feed with vegetable methionine source and choline as phosphatidylcholine. Daily weight gain, body weight, feed intake, feed conversion ratio, and mortality were evaluated for the periods of 1 to 21 and 1 to 42 days of age. During both periods, broilers fed the vegetable methionine source presented lower daily gain and lower body weight. When only choline chloride was substituted by the alternative choline source, broiler performance was not different compared with that of the control group. The group fed the diet with substitution of both DL-methionine 99% and choline chloride 60% by natural sources presented lower daily weight gain, final body weight, and feed intake. Further research on alternative nutrient sources are required for the development of the organic production chain.

  4. Serine Metabolism Supports the Methionine Cycle and DNA/RNA Methylation through De Novo ATP Synthesis in Cancer Cells.

    Science.gov (United States)

    Maddocks, Oliver D K; Labuschagne, Christiaan F; Adams, Peter D; Vousden, Karen H

    2016-01-21

    Crosstalk between cellular metabolism and the epigenome regulates epigenetic and metabolic homeostasis and normal cell behavior. Changes in cancer cell metabolism can directly impact epigenetic regulation and promote transformation. Here we analyzed the contribution of methionine and serine metabolism to methylation of DNA and RNA. Serine can contribute to this pathway by providing one-carbon units to regenerate methionine from homocysteine. While we observed this contribution under methionine-depleted conditions, unexpectedly, we found that serine supported the methionine cycle in the presence and absence of methionine through de novo ATP synthesis. Serine starvation increased the methionine/S-adenosyl methionine ratio, decreasing the transfer of methyl groups to DNA and RNA. While serine starvation dramatically decreased ATP levels, this was accompanied by lower AMP and did not activate AMPK. This work highlights the difference between ATP turnover and new ATP synthesis and defines a vital function of nucleotide synthesis beyond making nucleic acids.

  5. PET i prekirurgisk evaluering av epilepsi

    OpenAIRE

    2010-01-01

    PET in presurgical evaluation of epilepsy. Background: Today, at Rikshospitalet PET medical center, FDG is used as a tracer in the PET investigations during the presurgical evaluation of patients with epilepsy. The purpose of this paper is to see if FGD-PET gives additional information compared with EEG and MR. Another purpose was to find out whether there is a need for new ligands, and which ones. Material and methods: All epilepsy order forms to FDG-PET at Rikshopitalet, during 2007...

  6. Investigation of the metal binding site in methionine aminopeptidase by density functional theory

    DEFF Research Database (Denmark)

    Jørgensen, Anne Techau; Norrby, Per-Ola; Liljefors, Tommy

    2002-01-01

    All methionine aminopeptidases exhibit the same conserved metal binding site. The structure of this site with either Co2+ ions or Zn2+ ions was investigated using density functional theory. The calculations showed that the structure of the site was not influenced by the identity of the metal ions....... This was the case for both of the systems studied; one based on the X-ray structure of the human methionine aminopeptidase type 2 (hMetAP-2) and the other based on the X-ray structure of the E. coli methionine aminopeptidase type 1 (eMetAP-1). Another important structural issue is the identity of the bridging...

  7. Review of Synthesis of Methionine%蛋氨酸合成方法概述

    Institute of Scientific and Technical Information of China (English)

    刘勤; 李宏

    2011-01-01

    Methionine is an important fine chemical. The domestic industry of methionine had fallen behind foreign same industry. The synthesis methods and production processes of methionine are reviewed, and their merits and demerits are also presented and discussed in detail.%蛋氨酸是重要的精细化工产品,国内蛋氨酸产业发展落后于国外.总结了蛋氨酸的各种合成方法及生产工艺流程,并且各种方法的优缺点得到了详细的介绍和讨论.

  8. Identification and Functional Analysis of the Gene Encoding Methionine-γ-Lyase in Brevibacterium linens

    OpenAIRE

    Amarita, Felix; Yvon, Mireille; Nardi, Michele; Chambellon, Emilie; Delettre, Jerôme; Bonnarme, Pascal

    2004-01-01

    The enzymatic degradation of l-methionine and subsequent formation of volatile sulfur compounds (VSCs) is believed to be essential for flavor development in cheese. l-Methionine-γ-lyase (MGL) can convert l-methionine to methanethiol (MTL), α-ketobutyrate, and ammonia. The mgl gene encoding MGL was cloned from the type strain Brevibacterium linens ATCC 9175 known to produce copious amounts of MTL and related VSCs. The disruption of the mgl gene, achieved in strain ATCC 9175, resulted in a 62% ...

  9. Autoradiographic visualization in comparison with the incorporation of 35S-methionine by various tissue protein

    International Nuclear Information System (INIS)

    The purpose of the present study was to observe the incorporation level of 35S-methionine by various tissue protein in organism. By the use of the macro- and micro-autoradiographic technique, the incorporation of 35S-methionine by the tissues has been utilized as an index of tissue protein synthesis. Further experiments showed that 35S-methionine was dominantly incorporated in the liver, kidney and spleen. It indicated that a strong protein metabolism produced in these tissues. In spite of the important physiological function of the heart, lung and skeletal muscle, the protein metabolism in those tissues was in a low level

  10. Scintillation crystals required for PET

    International Nuclear Information System (INIS)

    In PET, inorganic scintillator crystals are used to record γ rays produced by the annihilation of positrons emitted by injected tracers. The ultimate performance of the camera is strongly tied to both the physical and scintillation properties of the crystals. For this reason, researchers have investigated virtually all known scintillator crystals for possible use in PET. Despite this massive research effort, only a few different scintillators have been found that have a suitable use. Two recently developed scintillator crystals (LSO and GSO), appears to surpass all previously used materials in most respects and promises to be the basis for the next generation of PET cameras. (authors)

  11. PET and PET/CT in tumour of undetermined origin

    International Nuclear Information System (INIS)

    In this presentation the following conclusions were obtained regarding the use of PET and PET/CT in patient with cancer of unknown primary: 1. Detection of the primary one in 1/3 at 1/2 of patient. 2. It detects metastases in other places in 50%. 3. It changes the initial therapy planned in 1/3 at 1/2 of patient. 4. Useful in initial phases of protocol study to limit the other procedures. After standard evaluation. Before advanced protocol. 5. PET/CT study increases the % of primary detection, although in a non significant way vs. PET. 6. They are required more studies to value their utility to a more objective manner. (Author)

  12. A novel, integrated PET-guided MRS technique resulting in more accurate initial diagnosis of high-grade glioma.

    Science.gov (United States)

    Kim, Ellen S; Satter, Martin; Reed, Marilyn; Fadell, Ronald; Kardan, Arash

    2016-06-01

    Glioblastoma multiforme (GBM) is the most common and lethal malignant glioma in adults. Currently, the modality of choice for diagnosing brain tumor is high-resolution magnetic resonance imaging (MRI) with contrast, which provides anatomic detail and localization. Studies have demonstrated, however, that MRI may have limited utility in delineating the full tumor extent precisely. Studies suggest that MR spectroscopy (MRS) can also be used to distinguish high-grade from low-grade gliomas. However, due to operator dependent variables and the heterogeneous nature of gliomas, the potential for error in diagnostic accuracy with MRS is a concern. Positron emission tomography (PET) imaging with (11)C-methionine (MET) and (18)F-fluorodeoxyglucose (FDG) has been shown to add additional information with respect to tumor grade, extent, and prognosis based on the premise of biochemical changes preceding anatomic changes. Combined PET/MRS is a technique that integrates information from PET in guiding the location for the most accurate metabolic characterization of a lesion via MRS. We describe a case of glioblastoma multiforme in which MRS was initially non-diagnostic for malignancy, but when MRS was repeated with PET guidance, demonstrated elevated choline/N-acetylaspartate (Cho/NAA) ratio in the right parietal mass consistent with a high-grade malignancy. Stereotactic biopsy, followed by PET image-guided resection, confirmed the diagnosis of grade IV GBM. To our knowledge, this is the first reported case of an integrated PET/MRS technique for the voxel placement of MRS. Our findings suggest that integrated PET/MRS may potentially improve diagnostic accuracy in high-grade gliomas.

  13. 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.

  14. Cross-coupling reactions as valuable tool for the preparation of PET radiotracers.

    Science.gov (United States)

    Pretze, Marc; Grosse-Gehling, Philipp; Mamat, Constantin

    2011-01-01

    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 (t(½) = 20.4 min) and ¹⁸F (t½) = 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. PMID:21270732

  15. PET/TAC in Oncology; PET/TAC en Oncologia

    Energy Technology Data Exchange (ETDEWEB)

    Jimenez V, A.M. [Especialista en Medicina Nuclear, Profa. Depto. Radiologia de la Facultad de Medicina, Universidad Complutense de Madrid, Madrid (Spain)

    2007-07-01

    From this presentation of PET-TAC in oncology the following advantages on the conventional PET are obtained: 1. More short study and stadium in one session. 2. It adds the information of both techniques. 3. Better localization of leisure: affected organ, stadium change (neck, mediastinum, abdomen). 4. Reduction of false positive (muscle, brown fat, atelectasis, pneumonias, intestine, urinary vials, etc.). 5. Reduction of negative false. 6. Reduction of not conclusive. 7. More understandable for other specialists. 8. Biopsies guide. 9. Planning radiotherapy.

  16. PET study of cholinergic system in the brain

    International Nuclear Information System (INIS)

    Recently, we have developed a method to measure acetylcholinesterase (AChE) activity, a functional marker for cholinergic system, by positron emission tomography (PET) and carbon-11 labeled N-methyl-4-piperidyl acetate. Kinetic analysis of the radioactivity in the brain and the plasma yielded a rate constant ''k 3'' as an index of AChE activity. The ratios for the k 3 values for the cerebral cortex/thalamus/cerebellum/striatum found in healthy participants were 1/ 3/ 8/ 10, respectively, corresponding well with AChE activity ratios in the brain at necropsy (1/ 3/ 8/ 38), except for the striatum. In 23 healthy volunteers (age range: 24-89 years), there was no age-related decline of k 3 values in the cerebral cortex, suggesting AChE activity is preserved in aged cerebral cortex. In 11 patients with Alzheimer's disease, there was a significant reduction (-24%) of k 3 values in the cerebral cortex and hippocampus, suggesting a loss of ascending cholinergic system from the basal forebrain to the cerebral cortex and hippocampus. In 16 patients with Parkinson's disease, there was a significant reduction (-18%) of k 3 values in the cerebral cortex. In 10 patients with progressive supra nuclear palsy, there was a significant reduction (-38%) of k 3 values in the thalamus. This technique is useful for investigating central cholinergic system in neuro degenerative disorders with dementia. (author)

  17. PET study of cholinergic system in the brain

    Energy Technology Data Exchange (ETDEWEB)

    Shinotoh, Hitoshi [Chiba Univ. (Japan). School of Medicine

    1999-01-01

    Recently, we have developed a method to measure acetylcholinesterase (AChE) activity, a functional marker for cholinergic system, by positron emission tomography (PET) and carbon-11 labeled N-methyl-4-piperidyl acetate. Kinetic analysis of the radioactivity in the brain and the plasma yielded a rate constant ``k 3`` as an index of AChE activity. The ratios for the k 3 values for the cerebral cortex/thalamus/cerebellum/striatum found in healthy participants were 1/ 3/ 8/ 10, respectively, corresponding well with AChE activity ratios in the brain at necropsy (1/ 3/ 8/ 38), except for the striatum. In 23 healthy volunteers (age range: 24-89 years), there was no age-related decline of k 3 values in the cerebral cortex, suggesting AChE activity is preserved in aged cerebral cortex. In 11 patients with Alzheimer`s disease, there was a significant reduction (-24%) of k 3 values in the cerebral cortex and hippocampus, suggesting a loss of ascending cholinergic system from the basal forebrain to the cerebral cortex and hippocampus. In 16 patients with Parkinson`s disease, there was a significant reduction (-18%) of k 3 values in the cerebral cortex. In 10 patients with progressive supra nuclear palsy, there was a significant reduction (-38%) of k 3 values in the thalamus. This technique is useful for investigating central cholinergic system in neuro degenerative disorders with dementia. (author)

  18. Design, synthesis, radiolabeling and in vivo evaluation of potential positron emission tomography (PET) radioligands for brain imaging of the 5-HT7 receptor

    DEFF Research Database (Denmark)

    Lacivita, Enza; Niso, Mauro; Hansen, Hanne D.;

    2014-01-01

    considered optimal for brain penetration and low non-specific binding. 4-[2-(4-Methoxyphenyl)phenyl]-N-(pyridin-4-ylmethyl)piperazinehexanamide (23a) and N-pyridin-4-ylmethyl-3-[4-[2-(4-methoxyphenyl)phenyl]piperazin-1-yl]ethoxy]propanamide (26a) were radiolabeled on the methoxy group with carbon-11....... Positron emission tomography (PET) analysis revealed that [(11)C]-23a and [(11)C]-26a were P-glycoprotein (P-gp) substrates and rapidly metabolized, resulting in poor brain uptake. These features were not predicted by in vitro tests....

  19. Positron emission tomography (PET) study of patients with pituitary adenoma using labeled amino acid

    Energy Technology Data Exchange (ETDEWEB)

    Mineura, Katsuyoshi; Sasajima, Toshio; Sakamoto, Tetsuya; Kowada, Masayoshi (Akita Univ. (Japan). Hospital); Shishido, Fumio; Uemura, Kazuo

    1989-12-01

    Four cases with pituitary adenomas were studied using {sup 11}C-L-methionine (C-11 Met) positron-emission tomography (PET). The C-11 Met was intravenously administered at a dose of 0.6 mCi/kg. The uptake of the tracer for tumors was calculated on the PET images 45 min after the injection; the uptake index was represented as a percentage of the total count in the arterial blood over a period of 45 min. In all cases, the C-11 Met accumulated intensely in the tumor regions; the PET images clearly delineated the extent of the tumor. The C-11 Met uptake index for pituitary adenomas varied widely from 3.94 x 10{sup -2}% to 15.36 x 10{sup -2}%, with a mean of 7.87 x 10{sup -2}%. These indices for the tumors increased markedly in comparison with that of the contralateral left temporal gray matter as a nontumor region (1.89 x 10{sup -2}% to 2.43 x 10{sup -2}% with a mean of 2.06 x 10{sup -2}%). In a case of prolactinoma, repeated PET following bromocriptine treatment showed a decrease in the C-11 Met uptake index; this decrease reflected changes in the serum prolactin value. In another case with ACTH-producing adenoma, the T/NT (tumor/nontumor) ratio fell from 3.44 to 2.40; however, the C-11 Met index remained unchanged. C-11 Met PET images facilitate determining the extent of pituitary adenomas and the monitoring of tumor response to treatment. Further application may give useful knowledge on the amino-acid metabolism of the tumor. (author).

  20. 10 "Poison Pills" for Pets

    Science.gov (United States)

    ... Care Animal Welfare Veterinary Careers Public Health 10 "Poison Pills" for Pets Anyone who takes medication prescribed ... of all phone calls to the ASPCA Animal Poison Control Center (APCC) are about human medications. Your ...

  1. Pets and the immunocompromised person

    Science.gov (United States)

    ... affect the cat's immune system. This puts your cat at risk of other infections that may be spread to humans. Feed your pet only commercially prepared food and treats. Animals can get sick from undercooked ...

  2. Disaster Preparedness for Your Pet

    Science.gov (United States)

    ... Do not let your pet interact with other animals Use disinfectant to clean the cage and litter box Leptospirosis is a bacterial disease found in the urine of infected animals that can cause kidney damage and affect other ...

  3. Innovations in PET/CT

    DEFF Research Database (Denmark)

    Levin Klausen, T; Høgild Keller, S; Vinter Olesen, O;

    2012-01-01

    impressive anatomical details. PET/CT designs are facing many challenges such as the conversion of CT numbers to attenuation coefficients, giving rise to artefacts due to the presence of high Zeff material. Patient motion during scans degrades image quality and subsequent analysis, and is a challenge......There has been a longstanding interest in positron emission tomography (PET) in combination with computed tomography (CT). Mostly because of the lack of structural information in PET which makes it difficult to assess the precise location of tissue with metabolic uptake, whereas CT can provide...... especially as spatial resolution improves. Software based image fusion remains a complex issue outside the brain. State of the art image quality in a modern PET/CT system includes incorporation of point spread function (PSF) and time-of-flight (TOF) information into the reconstruction leading to the high...

  4. Selecting Safe Pets (For Parents)

    Science.gov (United States)

    ... Reports? What to Say Vaccines: Which Ones & When? Smart School Lunches Emmy-Nominated Video "Cerebral Palsy: Shannon's ... pets. If you're interested in rabbits, the House Rabbit Society is an excellent resource — visit its ...

  5. Preventing Ticks on Your Pets

    Science.gov (United States)

    ... Tickborne diseases abroad Borrelia miyamotoi Borrelia mayonii Preventing ticks on your pets Recommend on Facebook Tweet Share ... your cats without first consulting your veterinarian! Kill Ticks on Dogs A pesticide product that kills ticks ...

  6. PET/CT and PET - application in pediatric oncology; PET/CT und PET - Einsatz in der paediatrischen Onkologie

    Energy Technology Data Exchange (ETDEWEB)

    Franzius, C.; Lang, K.; Schober, O. [Klinik und Poliklinik fuer Nuklearmedizin, Univ. Muenster (Germany); Wormanns, D. [Inst. fuer klinische Radiologie, Univ. Muenster (Germany); Vormoor, J. [Klinik und Poliklinik fuer Kinder- und Jugendmedizin - Paediatrische Haematologie und Onkologie, Univ. Muenster (Germany)

    2004-12-01

    PET-CT is a new imaging technology with a high capability to improve oncologic imaging. Introduction into clinical practise started approximately 3 years ago. Consequently, the available literature data are preliminary. There are no studies concerning PET-CT in pediatric patients. Nevertheless, it can already be supposed that the synthesis of structural and metabolic information improves the accuracy of staging and has the realistic potential to change patient management in a relevant percentage rate in pediatric patients. In this article, the advantages and special features of the application of PET-CT in young oncologic patients are pointed out. Potential clinical applications of PET-CT in this patient group include Hodgkin and non-Hodgkin lymphomas, Ewing tumors, osteosarcomas, rhabdomyosarcomas and neuroblastomas. (orig.)

  7. PET and PET/CT in tumour of undetermined origin; PET y PET/CT en tumor de origen indeterminado

    Energy Technology Data Exchange (ETDEWEB)

    Garcia O, J.R. [Nuclear Medicine and Molecular Imaging, PET/CT, Centro Medico ABC, Mexico D.F. (Mexico)

    2007-07-01

    In this presentation the following conclusions were obtained regarding the use of PET and PET/CT in patient with cancer of unknown primary: 1. Detection of the primary one in 1/3 at 1/2 of patient. 2. It detects metastases in other places in 50%. 3. It changes the initial therapy planned in 1/3 at 1/2 of patient. 4. Useful in initial phases of protocol study to limit the other procedures. After standard evaluation. Before advanced protocol. 5. PET/CT study increases the % of primary detection, although in a non significant way vs. PET. 6. They are required more studies to value their utility to a more objective manner. (Author)

  8. PET/TAC in Oncology

    International Nuclear Information System (INIS)

    From this presentation of PET-TAC in oncology the following advantages on the conventional PET are obtained: 1. More short study and stadium in one session. 2. It adds the information of both techniques. 3. Better localization of leisure: affected organ, stadium change (neck, mediastinum, abdomen). 4. Reduction of false positive (muscle, brown fat, atelectasis, pneumonias, intestine, urinary vials, etc.). 5. Reduction of negative false. 6. Reduction of not conclusive. 7. More understandable for other specialists. 8. Biopsies guide. 9. Planning radiotherapy

  9. Increasing levels of dietary crystalline methionine affect plasma methionine profiles, ammonia excretion, and the expression of genes related to the hepatic intermediary metabolism in rainbow trout (Oncorhynchus mykiss)

    DEFF Research Database (Denmark)

    Rolland, Marine; Skov, Peter Vilhelm; Larsen, Bodil Katrine;

    2016-01-01

    concentrations. The transcript levels of enzymes involved in lipid metabolism (fatty acid synthase, glucose 6 phosphate dehydrogenase and carnitine palmitoyl transferase 1 a), gluconeogenesis (fructose-1,6-biphosphatase) and amino acid catabolism (alanine amino transferase and glutamate dehydrogenase) were......Strictly carnivorous fish with high requirements for dietary protein, such as rainbow trout (Oncorhynchus mykiss) are interesting models for studying the role of amino acids as key regulators of intermediary metabolism. Methionine is an essential amino acid for rainbow trout, and works...... as a signalling factor in different metabolic pathways. The study investigated the effect of increasing dietary methionine intake on the intermediary metabolism in the liver of juvenile rainbow trout. For this purpose, five diets were formulated with increasing methionine levels from 0.60 to 1.29% dry matter...

  10. Ferulic acid depletion by cultured soybean seedlings under action of glucose and methionine

    Directory of Open Access Journals (Sweden)

    Herrig Vanessa

    2000-01-01

    Full Text Available Cultured soybean seedlings were used to investigate how glucose or methionine influenced depletion of ferulic acid. Three-day-old seedlings were grown in hydroponic solution containing ferulic acid plus glucose or methionine, and the level of the phenolic acid were monitored in the nutrient culture. The results showed that ferulic acid depletion was more rapid in the presence of those compounds. After 6 h, the increase caused by glucose (0.01 and 0.05 mM was more pronounced than methionine in the same concentrations. On the other hand, methionine (0.1 and 0.2 mM increased depletion more significantly than glucose. Results suggested that both compounds might to increase the allelopathic effects of ferulic acid in the seedlings.

  11. Tetracene confinement in L-methionine gratings on the Ag(111) surface

    Science.gov (United States)

    Urgel, José I.; Vijayaraghavan, S.; Ecija, D.; Auwärter, W.; Barth, J. V.

    2016-01-01

    We present a direct study on the positioning and mobility of tetracene molecules in self-assembled methionine nanogratings on the Ag(111) surface. Our scanning tunneling microscopy observations reveal the preferential arrangement of isolated tetracene units within substrate stripes framed by one-dimensional methionine supramolecular rows, under the influence of long-range indirect interactions. However, the orientational order of the rod-like tetracene species is induced by the epitaxial fit to the underlying surface atomic lattice; and preferential alignment with the tetracene axes along the direction of the methionine grating could not be achieved. In scanning tunneling microscopy measurements under perturbative conditions, we find a one-dimensional diffusion of the confined tetracene along the direction of the molecular axis and restricted by the methionine gratings for non-parallel orientations.

  12. Methionine-choline deprivation alters liver and brain acetylcholinesterase activity in C57BL6 mice.

    Science.gov (United States)

    Vučević, Danijela B; Cerović, Ivana B; Mladenović, Dušan R; Vesković, Milena N; Stevanović, Ivana; Jorgačević, Bojan Z; Ješić Vukićević, Rada; Radosavljević, Tatjana S

    2016-07-01

    Choline and methionine are precursors of acetylcholine, whose hydrolysis is catalyzed by acetylcholinesterase (AChE). Considering the possibility of their common deficiency, we investigated the influence of methionine-choline deprivation on AChE activity in liver and various brain regions (hypothalamus, hippocampus, cerebral cortex and striatum) in mice fed with methionine-choline deficient (MCD) diet. Male C57BL/6 mice (n = 28) were randomly and equally divided into following groups: control group fed with standard diet for 6 weeks (C) and groups fed with MCD diet for 2 weeks (MCD2), 4 weeks (MCD4) and for 6 weeks (MCD6). After the diet, mice were sacrificied and AChE activity in liver and brain was determined spectrophotometrically. Hepatic AChE activity was higher in MCD2, MCD4 and MCD6 compared to control (p methionine-choline deprivation.

  13. Dietary folate, methionine, riboflavin, and vitamin B-6 and risk of sporadic colorectal cancer

    NARCIS (Netherlands)

    Vogel, S. de; Dindore, V.; Engeland, M. van; Goldbohm, R.A.; Brandt, P.A. van den; Weijenberg, M.P.

    2008-01-01

    Adequate intake of folate, methionine, riboflavin, and vitamin B-6 may prevent aberrant DNA methylation and thereby protect against colorectal cancer (CRC). However, previous epidemiological studies investigating associations between dietary intakes of these nutrients and CRC have been inconsistent.

  14. Nutritional sustainability of pet foods.

    Science.gov (United States)

    Swanson, Kelly S; Carter, Rebecca A; Yount, Tracy P; Aretz, Jan; Buff, Preston R

    2013-03-01

    Sustainable practices meet the needs of the present without compromising the ability of future generations to meet their needs. Applying these concepts to food and feed production, nutritional sustainability is the ability of a food system to provide sufficient energy and essential nutrients required to maintain good health in a population without compromising the ability of future generations to meet their nutritional needs. Ecological, social, and economic aspects must be balanced to support the sustainability of the overall food system. The nutritional sustainability of a food system can be influenced by several factors, including the ingredient selection, nutrient composition, digestibility, and consumption rates of a diet. Carbon and water footprints vary greatly among plant- and animal-based ingredients, production strategy, and geographical location. Because the pet food industry is based largely on by-products and is tightly interlinked with livestock production and the human food system, however, it is quite unique with regard to sustainability. Often based on consumer demand rather than nutritional requirements, many commercial pet foods are formulated to provide nutrients in excess of current minimum recommendations, use ingredients that compete directly with the human food system, or are overconsumed by pets, resulting in food wastage and obesity. Pet food professionals have the opportunity to address these challenges and influence the sustainability of pet ownership through product design, manufacturing processes, public education, and policy change. A coordinated effort across the industry that includes ingredient buyers, formulators, and nutritionists may result in a more sustainable pet food system. PMID:23493530

  15. PET-CT beyond FDG. A quick guide to image interpretation

    Energy Technology Data Exchange (ETDEWEB)

    Fanti, Stefano [Bologna Univ. (Italy). Policlinico S.Orsola-Malpighi Medicina Nucleare; Farsad, Mohsen [Central Hospital Bozen, Bolzano (Italy). Nuclear Medicine; Mansi, Luigi [Napoli Univ. (Italy). Ist. Scienze Radiologiche

    2010-07-01

    Although [{sup 18}F]fluorodeoxyglucose (FDG) generally shows an excellent performance as a cancer-imaging agent when using PET-CT, there are some settings in which other radiopharmaceuticals offer advantages. Such non-FDG tracers are now gaining widespread acceptance not only in research but also in clinical practice, with the acquisition of promising results in the management of various cancers. This atlas, including about 500 high-quality images, is a user-friendly guide to PET-CT imaging beyond FDG. A wide range of tracers is covered, such as {sup 18}F- and {sup 11}C-choline, {sup 11}C-methionine, {sup 18}F-ethyl-L-tyrosine, {sup 68}Ga-DOTA-NOC, {sup 11}C-acetate, {sup 11}C-thymidine, and {sup 18}F-DOPA. Throughout, the emphasis is on image interpretation, with guidance on the recognition of normal, benign, and malignant uptake and clear instruction on learning points and pitfalls. This book is a companion to the editors' recently published Atlas of PET-CT, which focuses exclusively on the use of FDG. It is designed to serve as a reference text for both nuclear physicians and radiologists, and will also be of great benefit to radiographers, technologists, and nuclear medicine and radiology residents. (orig.)

  16. Palm tocotrienol-rich fraction inhibits methionine-induced cystathionine β-synthase in rat liver.

    Science.gov (United States)

    Kamisah, Yusof; Norsidah, Ku-Zaifah; Azizi, Ayob; Faizah, Othman; Nonan, Mohd Rizal; Asmadi, Ahmad Yusof

    2015-12-01

    Oxidative stress plays an important role in cardiovascular diseases. The study investigated the effects of dietary palm tocotrienol-rich fraction on homocysteine metabolism in rats fed a high-methionine diet. Forty-two male Wistar rats were randomly assigned to six groups. Five groups were fed with high-methionine diet (1%) for 10 weeks. Groups 2 to 5 were also given dietary folate (8 mg/kg) and three doses of palm tocotrienol-rich fraction (30, 60 and 150 mg/kg) from week 6 to week 10. The last group was only given basal rat chow. High-methionine diet increased plasma homocysteine after 10 weeks, which was prevented by the supplementations of folate and high-dose palm tocotrienol-rich fraction. Hepatic S-adenosyl methionine (SAM) content was unaffected in all groups but S-adenosyl homocysteine (SAH) content was reduced in the folate group. Folate supplementation increased the SAM/SAH ratio, while in the palm tocotrienol-rich fraction groups, the ratio was lower compared with the folate. Augmented activity of hepatic cystathionine β-synthase and lipid peroxidation content by high-methionine diet was inhibited by palm tocotrienol-rich fraction supplementations (moderate and high doses), but not by folate. The supplemented groups had lower hepatic lipid peroxidation than the high-methionine diet. In conclusion, palm tocotrienol-rich fraction reduced high-methionine-induced hyperhomocysteinaemia possibly by reducing hepatic oxidative stress in high-methionine-fed rats. It may also exert a direct inhibitory effect on hepatic cystathionine β-synthase.

  17. Methionine biosynthesis is essential for infection in the rice blast fungus Magnaporthe oryzae.

    Science.gov (United States)

    Saint-Macary, Marie Emmanuelle; Barbisan, Crystel; Gagey, Marie Josèphe; Frelin, Océane; Beffa, Roland; Lebrun, Marc Henri; Droux, Michel

    2015-01-01

    Methionine is a sulfur amino acid standing at the crossroads of several biosynthetic pathways. In fungi, the last step of methionine biosynthesis is catalyzed by a cobalamine-independent methionine synthase (Met6, EC 2.1.1.14). In the present work, we studied the role of Met6 in the infection process of the rice blast fungus, Magnaporthe oryzae. To this end MET6 null mutants were obtained by targeted gene replacement. On minimum medium, MET6 null mutants were auxotrophic for methionine. Even when grown in presence of excess methionine, these mutants displayed developmental defects, such as reduced mycelium pigmentation, aerial hypha formation and sporulation. They also displayed characteristic metabolic signatures such as increased levels of cysteine, cystathionine, homocysteine, S-adenosylmethionine, S-adenosylhomocysteine while methionine and glutathione levels remained unchanged. These metabolic perturbations were associated with the over-expression of MgCBS1 involved in the reversed transsulfuration pathway that metabolizes homocysteine into cysteine and MgSAM1 and MgSAHH1 involved in the methyl cycle. This suggests a physiological adaptation of M. oryzae to metabolic defects induced by the loss of Met6, in particular an increase in homocysteine levels. Pathogenicity assays showed that MET6 null mutants were non-pathogenic on both barley and rice leaves. These mutants were defective in appressorium-mediated penetration and invasive infectious growth. These pathogenicity defects were rescued by addition of exogenous methionine and S-methylmethionine. These results show that M. oryzae cannot assimilate sufficient methionine from plant tissues and must synthesize this amino acid de novo to fulfill its sulfur amino acid requirement during infection.

  18. Methionine synthase reductase deficiency results in adverse reproductive outcomes and congenital heart defects in mice

    OpenAIRE

    Deng, Liyuan; Elmore, C. Lee; Lawrance, Andrea K.; Matthews, Rowena G.; Rozen, Rima

    2008-01-01

    Low dietary folate and polymorphisms in genes of folate metabolism can influence risk for pregnancy complications and birth defects. Methionine synthase reductase (MTRR) is required for activation of methionine synthase, a folate- and vitamin B12-dependent enzyme. A polymorphism in MTRR (p.I22M), present in the homozygous state in 25% of many populations, may increase risk for neural tube defects. To examine the impact of MTRR deficiency on early development and congenital heart defects, we u...

  19. A Methionine-Induced Animal Model of Schizophrenia: Face and Predictive Validity

    OpenAIRE

    Wang, Lien; Alachkar, Amal; Sanathara, Nayna; Belluzzi, James D.; Wang, Zhiwei; Civelli, Olivier

    2015-01-01

    Background: Modulating the methylation process induces broad biochemical changes, some of which may be involved in schizophrenia. Methylation is in particular central to epigenesis, which is also recognized as a factor in the etiology of schizophrenia. Because methionine administration to patients with schizophrenia has been reported to exacerbate their psychotic symptoms and because mice treated with methionine exhibited social deficits and prepulse inhibition impairment, we investigated whe...

  20. Effect of methionine hydroxy analog supplementation on dairy cattle hoof growth and composition.

    Science.gov (United States)

    Clark, A K; Rakes, A H

    1982-08-01

    Fifty lactating Holstein cows were assigned randomly to one of two treatments, control and control plus approximately 30 g methionine hydroxy analog, and confined on concrete for 11 mo. The control diet consisted of sorghum silage and concentrate fed as a blended ration. Sulfur contents of dry matter were .12% and .16% for control and methionine hydroxy analog rations. Hoof growth and hardness were measured on front and rear right abaxial claws in the dorsal and lateral regions. Hoof growth rates were measured for four periods; summer-fall, fall-winter, winter-spring, and spring-summer, each 70 to 90 days. Hooves of cows fed methionine hydroxy analog grew faster than those of control cows during spring-summer in all regions. Variations of growth rates of hooves were seasonal and tended to follow variations in daily photoperiod. Wear rates were not affected significantly by treatment. Hooves of cows fed methionine hydroxy analog were softer in the top dorsal region at the end of winter-spring and in the dorsal toe region at the end of spring-summer. All other locations were not affected significantly by treatment. The toe region was harder than the top of the hoof. Cows fed methionine hydroxy analog had less cysteine and proline in hoof than control cows and greater percentages of methionine lysine, tyrosine, and glutamic acid. These results suggest that a decrease of disulfide bonding occurred in the hoof tissue of cows fed methionine hydroxy analog. Cows fed methionine hydroxy analog produced more actual milk, milk fat, and 4% fat-corrected milk during 180 days than did control cows.

  1. The effect of methionine and 5-azacytidine on fragile X expression.

    OpenAIRE

    Abruzzo, M A; Mayer, M.; Jacobs, P A

    1985-01-01

    The cellular mechanism for the expression of the fragile site at Xq28 is unknown. We tested the effect of 5-azacytidine and methionine on fragile X expression in lymphocytes and lymphoblastoid cells in an attempt to determine if DNA methylation was involved. We were unable to demonstrate a consistent dosage effect of methionine on fragile X expression. While 5-azacytidine was found to inhibit the fragile X in both males and females, it did so only at relatively high concentrations. We conclud...

  2. Low-Dose Methotrexate Inhibits Methionine S-Adenosyltransferase In Vitro and In Vivo

    OpenAIRE

    Wang, Yi-cheng; Chiang, En-Pei Isabel

    2011-01-01

    Methionine S-adenosyltransferase (MAT) catalyzes the only reaction that produces the major methyl donor in mammals. Low-dose methotrexate is the most commonly used disease-modifying antirheumatic drug in human rheumatic conditions. The present study was conducted to test the hypothesis that methotrexate inhibits MAT expression and activity in vitro and in vivo. HepG2 cells were cultured under folate restriction or in low-dose methotrexate with and without folate or methionine supplementation....

  3. Methionine flux to transsulfuration is enhanced in the long living Ames dwarf mouse

    OpenAIRE

    Uthus, Eric O; Holly M. Brown-Borg

    2006-01-01

    Long-lived Ames dwarf mice lack growth hormone, prolactin, and thyroid stimulating hormone. Additionally the dwarf mice have enzyme activities and levels that combat oxidative stress more efficiently than those of normal mice. We have shown that methionine metabolism in Ames mice is markedly different than in their wild type littermates. In our previous work we hypothesized that the flux of methionine to the transsulfuration pathway is enhanced in the dwarf mice. The current study was designe...

  4. PET AND PET-CT: PHYSICAL PRINCIPLE AND MEDICAL APLICATIONS

    Directory of Open Access Journals (Sweden)

    V.Rusu

    2007-04-01

    Full Text Available Positron emission tomography (PET is a noninvasive imaging method that can “see” the metabolisms inside the living cells. It involves the acquisition of functional images based on the detection of radiation coming from the positron emission of a radiotracer administered to the patient. This radiotracer can be a metabolic analog, like is the case of glucose analog 2-[fluorine-18]-fluoro-2-deoxy-D-glucose (18FDG, the most commonly used PET radiotracer. PET images of the human body are used to evaluate a variety of diseases, most often to detect cancer and to examine the effects of cancer therapy by characterizing cell viability and biochemical changes in the cell. It is potentially useful in cancer imaging because the increased metabolism of tumor cells leads to increased uptake of glucose, and, therefore, uptake of 18FDG, also. PET-CT is the fusion of functional and anatomic information acquired almost simultaneously, that lets us see both the structural anatomy and the functional data on the same image. They complete each other: if PET scan is powerful in evaluating the functional characteristics of the tissues, CT is a powerful structural resolution imaging method. The highly sensitive PET scan detects the metabolic signal of actively growing cancer cells in the body and the CT scan provides a detailed picture of the internal anatomy that reveals sites, size and shape of cancer tissue. Alone, each imaging test has particular benefits and limitations but when the results of PET and CT scans are "fused" together, the combined image provides complete information on cancer location and metabolism.

  5. Impact of methionine oxidation on calmodulin structural dynamics

    Energy Technology Data Exchange (ETDEWEB)

    McCarthy, Megan R.; Thompson, Andrew R.; Nitu, Florentin [Biochemistry, Molecular Biology and Biophysics Department, University of Minnesota, Minneapolis, MN 55455 (United States); Moen, Rebecca J. [Chemistry and Geology Department, Minnesota State University, Mankato, MN 56001 (United States); Olenek, Michael J. [Biology Department, University of Wisconsin, La Crosse, WI 54601 (United States); Klein, Jennifer C., E-mail: jklein@uwlax.edu [Biology Department, University of Wisconsin, La Crosse, WI 54601 (United States); Thomas, David D., E-mail: ddt@umn.edu [Biochemistry, Molecular Biology and Biophysics Department, University of Minnesota, Minneapolis, MN 55455 (United States)

    2015-01-09

    Highlights: • We measured the distance distribution between two spin labels on calmodulin by DEER. • Two structural states, open and closed, were resolved at both low and high Ca. • Ca shifted the equilibrium toward the open state by a factor of 13. • Methionine oxidation, simulated by glutamine substitution, decreased the Ca effect. • These results have important implications for aging in muscle and other tissues. - Abstract: We have used electron paramagnetic resonance (EPR) to examine the structural impact of oxidizing specific methionine (M) side chains in calmodulin (CaM). It has been shown that oxidation of either M109 or M124 in CaM diminishes CaM regulation of the muscle calcium release channel, the ryanodine receptor (RyR), and that mutation of M to Q (glutamine) in either case produces functional effects identical to those of oxidation. Here we have used site-directed spin labeling and double electron–electron resonance (DEER), a pulsed EPR technique that measures distances between spin labels, to characterize the structural changes resulting from these mutations. Spin labels were attached to a pair of introduced cysteine residues, one in the C-lobe (T117C) and one in the N-lobe (T34C) of CaM, and DEER was used to determine the distribution of interspin distances. Ca binding induced a large increase in the mean distance, in concert with previous X-ray crystallography and NMR data, showing a closed structure in the absence of Ca and an open structure in the presence of Ca. DEER revealed additional information about CaM’s structural heterogeneity in solution: in both the presence and absence of Ca, CaM populates both structural states, one with probes separated by ∼4 nm (closed) and another at ∼6 nm (open). Ca shifts the structural equilibrium constant toward the open state by a factor of 13. DEER reveals the distribution of interprobe distances, showing that each of these states is itself partially disordered, with the width of each

  6. Dysregulated Hepatic Methionine Metabolism Drives Homocysteine Elevation in Diet-Induced Nonalcoholic Fatty Liver Disease.

    Science.gov (United States)

    Pacana, Tommy; Cazanave, Sophie; Verdianelli, Aurora; Patel, Vaishali; Min, Hae-Ki; Mirshahi, Faridoddin; Quinlivan, Eoin; Sanyal, Arun J

    2015-01-01

    Methionine metabolism plays a central role in methylation reactions, production of glutathione and methylarginines, and modulating homocysteine levels. The mechanisms by which these are affected in NAFLD are not fully understood. The aim is to perform a metabolomic, molecular and epigenetic analyses of hepatic methionine metabolism in diet-induced NAFLD. Female 129S1/SvlmJ;C57Bl/6J mice were fed a chow (n = 6) or high-fat high-cholesterol (HFHC) diet (n = 8) for 52 weeks. Metabolomic study, enzymatic expression and DNA methylation analyses were performed. HFHC diet led to weight gain, marked steatosis and extensive fibrosis. In the methionine cycle, hepatic methionine was depleted (30%, pmethionine ratio (pmethionine adenosyltransferase 1A, cystathionine β-synthase, γ-glutamylcysteine synthetase, betaine-homocysteine methyltransferase, and methionine synthase remained unchanged. Although gene expression of the DNA methyltransferase Dnmt3a decreased, the global DNA methylation was unaltered. Among individual genes, only HMG-CoA reductase (Hmgcr) was hypermethylated, and no methylation changes were observed in fatty acid synthase (Fasn), nuclear factor of kappa light polypeptide gene enhancer in B-cells 1 (Nfκb1), c-Jun, B-cell lymphoma 2 (Bcl-2) and Caspase 3. NAFLD was associated with hepatic methionine deficiency and homocysteine elevation, resulting mainly from impaired homocysteine remethylation, and aberrancy in methyltransferase reactions. Despite increased PRMT1 expression, hepatic ADMA was depleted while circulating ADMA was increased, suggesting increased export to circulation.

  7. D-methionine protects against cisplatin-induced neurotoxicity in the hippocampus of the adult rat.

    Science.gov (United States)

    Hinduja, Sneha; Kraus, Kari Suzanne; Manohar, Senthilvelan; Salvi, Richard J

    2015-04-01

    The hippocampus plays an important role in memory, mood, and spatial navigation. In the dentate gyrus of the adult hippocampus, in the subgranular zone (SGZ), new cells are generated, which differentiate and mature into new neurons. Cisplatin, a highly effective antineoplastic drug with nephrotoxic and ototoxic side effects, induces apoptosis and suppresses neurogenesis in the hippocampus leading to memory impairment. Previous studies have shown that the antioxidant D-methionine protects against cisplatin-induced ototoxicity and nephrotoxicity suggesting that it might also prevent neurogenesis from being suppressed by cisplatin treatment. To test this hypothesis, rats were treated with cisplatin, D-methionine, cisplatin plus D-methionine, or saline (controls). Seven days after treatment, the rats were sacrificed, and hippocampal sections immunolabeled for doublecortin (DCX) to identify neuronal precursor cells and maturing neurons in the SGZ. Cisplatin significantly reduced the number of DCX-labeled cells (~80 %) relative to controls. In contrast, DCX cell counts in rats treated with D-methionine prior to cisplatin were similar to controls. The treatment with D-methionine alone did not affect the number of DCX cells. These results indicate that D-methionine prevents the dramatic cisplatin-induced decrease of neurogenesis.

  8. Selective Oxidation of Methionine and Tryptophan Residues in a Therapeutic IgG1 Molecule.

    Science.gov (United States)

    Folzer, Emilien; Diepold, Katharina; Bomans, Katrin; Finkler, Christof; Schmidt, Roland; Bulau, Patrick; Huwyler, Jörg; Mahler, Hanns-Christian; Koulov, Atanas V

    2015-09-01

    Oxidation of methionine and tryptophan are common degradation pathways for monoclonal antibodies and present major analytical challenges in biotechnology. Generally, protein oxidation is detectable in stability and/or stressed samples (e.g., exposed to hydrogen peroxide, UV light, or metal ions). The induced chemical modifications may impact the biological activity of antibodies and may have biological consequences. However, these effects and the contribution of individual protein modifications are difficult to delineate as different amino acids are often oxidized simultaneously and accompanied by other degradants such as aggregates, especially in forced degradation studies. Here, we report a new method to obtain selective oxidation of methionine or tryptophan by using oxidation reagents combined with large excess of free tryptophan or methionine, correspondingly. More specifically, using hydrogen peroxide or tert-butyl hydroperoxide in combination with addition of free tryptophan allowed for selective oxidation of methionine. Conversely, the use of 2,2-azobis(2-amidinopropane) dihydrochloride in combination with free methionine resulted in selective tryptophan oxidation, whereas methionine oxidation was not significantly altered. This novel stress model system may prove to be valuable tool in future mechanistic studies of oxidative degradation of protein therapeutics.

  9. Influence of dietary protein and excess methionine on choline needs for young bobwhite quail

    Science.gov (United States)

    Serafin, J.A.

    1982-01-01

    Experiments were conducted with young Bobwhite quail (Colinus virginianus) to investigate the effect of differing dietary protein levels and nondetrimental amounts of excess methionine on choline needs. Growth and feed consumption of quail fed an adequate (27.3%) protein purified diet supplemented with 2000 mg/kg of choline were unaffected by increasing the level of excess methionine to 1.75%; however, greater amounts (2.0%, 2.25%) of excess methionine depressed growth (P less than .01), reduced feed consumption (P less than .01), and decreased feed utilization (P less than .05). Quail fed a purified diet containing 13.85% protein and 515 mg/kg of choline grew poorly. Growth was unaffected by additional choline in this diet. Growth was suboptimal among quail fed purified diets containing adequate or high (41.55%) levels of protein in which choline was limiting; however, a high level of protein did not in itself affect performance. Growth was improved by supplemental choline in these diets. Growth of quail fed purified diets with up to 1.35% excess methionine which were limiting (531 mg/kg) in choline was less than that of groups fed 2000 mg/kg of added dietary choline (P less than .01); however, excess methionine did not significantly influence growth of quail fed choline-deficient diets. These experiments indicate that neither high dietary protein nor excess methionine, fed at non-growth-depressing levels, increases dietary choline needs for young Bobwhite quail.

  10. Changes in plasma methionine and total homocysteine levels in patients receiving methotrexate infusions.

    Science.gov (United States)

    Broxson, E H; Stork, L C; Allen, R H; Stabler, S P; Kolhouse, J F

    1989-11-01

    Methotrexate reduces intracellular pools of 5-methyltetrahydrofolate and could result in reduced conversion of homocysteine to methionine by methionine synthetase. This study was designed to investigate the effects of moderate dose to very high dose methotrexate on methionine and total homocysteine as reflections of methotrexate induced intracellular events. Methionine and total homocysteine were measured prior to, during, and following twenty-six 24-h i.v. infusions of 33.6 g/m2 methotrexate (very high dose methotrexate) in 16 children with acute lymphocytic leukemia and seven 4-h i.v. infusions of 8 g/m2 methotrexate (high dose methotrexate) in 5 children with osteogenic sarcoma. Amino acids were measured by gas chromatography/mass spectrophotometry. Mean methionine levels decreased by 70.0 +/- 3.1% (SE) with very high dose methotrexate and 72.6 +/- 5.9% with high dose methotrexate at 24 and 4.5 h, respectively, after beginning methotrexate infusions. Mean total homocysteine levels increased by 61.7 +/- 3.1% with very high dose methotrexate and 55.6 +/- 17.5% with high dose methotrexate at 36 and 24 h, respectively, after beginning methotrexate infusions. No consistent or significant changes were noted in levels of total cysteine, leucine, isoleucine, or valine. Similar changes did not occur in patients receiving prednisone, vincristine, daunomycin, and intrathecal methotrexate as therapy for acute lymphocytic leukemia. These changes in homocysteine and methionine may reflect biological effects of methotrexate that may predict cytotoxicity of methotrexate.

  11. Gamma camera based FDG PET in oncology

    International Nuclear Information System (INIS)

    Positron Emission Tomography(PET) was introduced as a research tool in the 1970s and it took about 20 years before PET became an useful clinical imaging modality. In the USA, insurance coverage for PET procedures in the 1990s was the turning point, I believe, for this progress. Initially PET was used in neurology but recently more than 80% of PET procedures are in oncological applications. I firmly believe, in the 21st century, one can not manage cancer patients properly without PET and PET is very important medical imaging modality in basic and clinical sciences. PET is grouped into 2 categories; conventional (c) and gamma camera based (CB) PET. CBPET is more readily available utilizing dual-head gamma cameras and commercially available FDG to many medical centers at low cost to patients. In fact there are more CBPET in operation than cPET in the USA. CBPET is inferior to cPET in its performance but clinical studies in oncology is feasible without expensive infrastructures such as staffing, rooms and equipments. At Ajou university Hospital, CBPET was installed in late 1997 for the first time in Korea as well as in Asia and the system has been used successfully and effectively in oncological applications. Our was the fourth PET operation in Korea and I believe this may have been instrumental for other institutions got interested in clinical PET. The following is a brief description of our clinical experience of FDG CBPET in oncology

  12. Expression of Four Methionine Sulfoxide Reductases in Staphylococcus aureus

    Directory of Open Access Journals (Sweden)

    Kuldeep Singh

    2012-01-01

    Full Text Available Staphylococcus aureus possesses three MsrA enzymes (MsrA1, MsrA2, MsrA3 that reduce the S-epimer of methionine sulfoxide (MetO and an MsrB enzyme that reduces R-MetO. The four msr genes are expressed from three different promoters. The msrA1/msrB genes are coexpressed. To determine the expression pattern of msr genes, three independent reporter strains were constructed where msr promoter was cloned in front of a promoterless lacZ and the resulting construct was integrated in the chromosome. Using these strains, it was determined that the msrA1/B expression is significantly higher in S. aureus compared to msrA2 or msrA3. Expression of msrA1/B was highest during stationary phase growth, but the expression of msrA2 and msrA3 was highest during the early to midexponential growth phase. Expression of msrA1/B was induced by oxacillin and the expression of msrA3 was upregulated by salt. Expression of msrA2 remained unchanged under all tested conditions.

  13. Fragmentation network of doubly charged methionine: Interpretation using graph theory

    Science.gov (United States)

    Ha, D. T.; Yamazaki, K.; Wang, Y.; Alcamí, M.; Maeda, S.; Kono, H.; Martín, F.; Kukk, E.

    2016-09-01

    The fragmentation of doubly charged gas-phase methionine (HO2CCH(NH2)CH2CH2SCH3) is systematically studied using the self-consistent charge density functional tight-binding molecular dynamics (MD) simulation method. We applied graph theory to analyze the large number of the calculated MD trajectories, which appears to be a highly effective and convenient means of extracting versatile information from the large data. The present theoretical results strongly concur with the earlier studied experimental ones. Essentially, the dication dissociates into acidic group CO2H and basic group C4NSH10. The former may carry a single or no charge and stays intact in most cases, whereas the latter may hold either a single or a double charge and tends to dissociate into smaller fragments. The decay of the basic group is observed to follow the Arrhenius law. The dissociation pathways to CO2H and C4NSH10 and subsequent fragmentations are also supported by ab initio calculations.

  14. Methionine AminoPeptidase Type-2 Inhibitors Targeting Angiogenesis.

    Science.gov (United States)

    Ehlers, Tedman; Furness, Scott; Robinson, Thomas Philip; Zhong, Haizhen A; Goldsmith, David; Aribser, Jack; Bowen, J Phillip

    2016-01-01

    Angiogenesis has been identified as a crucial process in the development and spread of cancers. There are many regulators of angiogenesis which are not yet fully understood. Methionine aminiopeptidase is a metalloenzyme with two structurally distinct forms in humans, Type-1 (MetAP-1) and Type-2 (MetAP-2). It has been shown that small molecule inhibitors of MetAP-2 suppress endothelial cell proliferation. The initial discovery by Donald Ingber of MetAP-2 inhibition as a potential target in angiogenesis began with a fortuitous observation similar to the discovery of penicillin activity by Sir Alexander Fleming. From a drug design perspective, MetAP-2 is an attractive target. Fumagillin and ovalicin, known natural products, bind with IC50 values in low nanomolar concentrations. Crystal structures of the bound complexes provide 3-dimensional coordinates for advanced computational studies. More recent discoveries have shown other biological activities for MetAP-2 inhibition, which has generated new interests in the design of novel inhibitors. Semisynthetic fumagillin derivatives such as AGM-1470 (TNP-470) have been shown to have better drug properties, but have not been very successful in clinical trials. The rationale and development of novel multicyclic analogs of fumagillin are reviewed. PMID:26369821

  15. [11C]PR04.MZ, a promising DAT ligand for low concentration imaging: synthesis, efficient 11C-0-methylation and initial small animal PET studies

    Energy Technology Data Exchange (ETDEWEB)

    Riss, P.J.; Hooker, J.; Alexoff, D.; Kim, Sung-Won; Fowler, J.S.; Roesch, F.

    2009-05-01

    PR04.MZ was designed as a highly selective dopamine transporter inhibitor, derived from natural cocaine. Its binding profile indicates that [{sup 11}C]PR04.MZ may be suited as a PET radioligand for the non-invasive exploration of striatal and extrastriatal DAT populations. As a key feature, its structural design facilitates both, labelling with fluorine-18 at its terminally fluorinated butynyl moiety and carbon-11 at its methyl ester function. The present report concerns the efficient [{sup 11}C]MeI mediated synthesis of [{sup 11}C]PR04.MZ from an O-desmethyl precursor trifluoroacetic acid salt with Rb{sub 2}CO{sub 3} in DMF in up to 95 {+-} 5% labelling yield. A preliminary {mu}PET-experiment demonstrates the reversible, highly specific binding of [{sup 11}C]PR04.MZ in the brain of a male Sprague-Dawley rat.

  16. Cysteine dietary supplementation reverses the decrease in mitochondrial ROS production at complex I induced by methionine restriction.

    Science.gov (United States)

    Gomez, A; Gomez, J; Lopez Torres, M; Naudi, A; Mota-Martorell, N; Pamplona, R; Barja, G

    2015-06-01

    It has been described that dietary cysteine reverses many of the beneficial changes induced by methionine restriction in aging rodents. In this investigation male Wistar rats were subjected to diets low in methionine, supplemented with cysteine, or simultaneously low in methionine and supplemented with cysteine. The results obtained in liver showed that cysteine supplementation reverses the decrease in mitochondrial ROS generation induced by methionine restriction at complex I. Methionine restriction also decreased various markers of oxidative and non-oxidative stress on mitochondrial proteins which were not reversed by cysteine. Instead, cysteine supplementation also lowered protein damage in association with decreases in mTOR activation. The results of the present study add the decrease in mitochondrial ROS production to the various beneficial changes induced by methionine restriction that are reversed by cysteine dietary supplementation.

  17. PET and PET/CT in oncology: the key of diagnostic challenge

    International Nuclear Information System (INIS)

    In this presentation authors present use of positron emission tomography (PET) in oncology. This lecture is divided to the following parts: (1) Assessment of treatment response; (2) Treatment monitoring by PET: clinical examples; (3) PET for early response assessment; (4) Use of PET in Radiotherapy planning

  18. Exercises in PET Image Reconstruction

    Science.gov (United States)

    Nix, Oliver

    These exercises are complementary to the theoretical lectures about positron emission tomography (PET) image reconstruction. They aim at providing some hands on experience in PET image reconstruction and focus on demonstrating the different data preprocessing steps and reconstruction algorithms needed to obtain high quality PET images. Normalisation, geometric-, attenuation- and scatter correction are introduced. To explain the necessity of those some basics about PET scanner hardware, data acquisition and organisation are reviewed. During the course the students use a software application based on the STIR (software for tomographic image reconstruction) library 1,2 which allows them to dynamically select or deselect corrections and reconstruction methods as well as to modify their most important parameters. Following the guided tutorial, the students get an impression on the effect the individual data precorrections have on image quality and what happens if they are forgotten. Several data sets in sinogram format are provided, such as line source data, Jaszczak phantom data sets with high and low statistics and NEMA whole body phantom data. The two most frequently used reconstruction algorithms in PET image reconstruction, filtered back projection (FBP) and the iterative OSEM (ordered subset expectation maximation) approach are used to reconstruct images. The exercise should help the students gaining an understanding what the reasons for inferior image quality and artefacts are and how to improve quality by a clever choice of reconstruction parameters.

  19. PET for Staging of Esophageal Cancer

    Institute of Scientific and Technical Information of China (English)

    A.H.Hoelscher

    2004-01-01

    FDG-PET is of clinical value especially for detection of distant metastases or recurrent esophageal cancer. For the staging of primary tumor or locoregional lymph node metastasis PET is currently not suitable.

  20. PET/MRI in cancer patients

    DEFF Research Database (Denmark)

    Kjær, Andreas; Loft, Annika; Law, Ian;

    2013-01-01

    described include brain tumors, pediatric oncology as well as lung, abdominal and pelvic cancer. In general the cases show that PET/MRI performs well in all these types of cancer when compared to PET/CT. However, future large-scale clinical studies are needed to establish when to use PET/MRI. We envision......Combined PET/MRI systems are now commercially available and are expected to change the medical imaging field by providing combined anato-metabolic image information. We believe this will be of particular relevance in imaging of cancer patients. At the Department of Clinical Physiology, Nuclear...... Medicine & PET at Rigshospitalet in Copenhagen we installed an integrated PET/MRI in December 2011. Here, we describe our first clinical PET/MR cases and discuss some of the areas within oncology where we envision promising future application of integrated PET/MR imaging in clinical routine. Cases...

  1. 7 CFR 500.10 - Pets.

    Science.gov (United States)

    2010-01-01

    ... NATIONAL ARBORETUM Conduct on U.S. National Arboreturm Property § 500.10 Pets. Pets brought upon USNA property must have proper vaccinations and, except assistance trained animals, must be kept on leash at...

  2. Children's drawings and attachment to pets.

    Science.gov (United States)

    Kidd, A H; Kidd, R M

    1995-08-01

    To help confirm the concept that distances placed between the self and other figures in children's drawings represent emotional distances, 242 pet-owning and 35 nonpet-owning kindergartners through eighth graders drew pictures of themselves, a pet, and/or a family member. Owners drew pets significantly closer than family-figures although the younger the child, the greater the distance between self and pet. Older children drew themselves holding pets significantly more often, but younger children placed the family-figure between the self and the pet significantly more often. There were no significant gender differences in self-figure/pet-figure distances, but cats, dogs, caged animals, and farm animals were placed significantly closer to self-figures than were fish. Over-all, owners were clearly emotionally closer to pets than to family members, but nonowners were as close emotionally to family members as were owners. PMID:7501763

  3. Modulation of cell cycle and gene expression in pancreatic tumor cell lines by methionine deprivation (methionine stress): implications to the therapy of pancreatic adenocarcinoma.

    Science.gov (United States)

    Kokkinakis, Demetrius M; Liu, Xiaoyan; Neuner, Russell D

    2005-09-01

    The effect of methionine deprivation (methionine stress) on the proliferation, survival, resistance to chemotherapy, and regulation of gene and protein expression in pancreatic tumor lines is examined. Methionine stress prevents successful mitosis and promotes cell cycle arrest and accumulation of cells with multiple micronuclei with decondensed chromatin. Inhibition of mitosis correlates with CDK1 down-regulation and/or inhibition of its function by Tyr(15) phosphorylation or Thr(161) dephosphorylation. Inhibition of cell cycle progression correlates with loss of hyperphosphorylated Rb and up-regulation of p21 via p53 and/or transforming growth factor-beta (TGF-beta) activation depending on p53 status. Although methionine stress-induced toxicity is not solely dependent on p53, the gain in p21 and loss in CDK1 transcription are more enhanced in wild-type p53 tumors. Up-regulation of SMAD7, a TGF-beta signaling inhibitor, suggests that SMAD7 does not restrict the TGF-beta-mediated induction of p21, although it may prevent up-regulation of p27. cDNA oligoarray analysis indicated a pleiotropic response to methionine stress. Cell cycle and mitotic arrest is in agreement with up-regulation of NF2, ETS2, CLU, GADD45alpha, GADD45beta, and GADD45gamma and down-regulation of AURKB, TOP2A, CCNA, CCNB, PRC1, BUB1, NuSAP, IFI16, and BRCA1. Down-regulation of AREG, AGTR1, M-CSF, and EGF, IGF, and VEGF receptors and up-regulation of GNA11 and IGFBP4 signify loss of growth factor support. PIN1, FEN1, and cABL up-regulation and LMNB1, AREG, RhoB, CCNG, TYMS, F3, and MGMT down-regulation suggest that methionine stress sensitizes the tumor cells to DNA-alkylating drugs, 5-fluorouracil, and radiation. Increased sensitivity of pancreatic tumor cell lines to temozolomide is shown under methionine stress conditions and is attributed in part to diminished O(6)-methylguanine-DNA methyltransferase and possibly to inhibition of the cell cycle progression. PMID:16170025

  4. Modulation of cell cycle and gene expression in pancreatic tumor cell lines by methionine deprivation (methionine stress): implications to the therapy of pancreatic adenocarcinoma.

    Science.gov (United States)

    Kokkinakis, Demetrius M; Liu, Xiaoyan; Neuner, Russell D

    2005-09-01

    The effect of methionine deprivation (methionine stress) on the proliferation, survival, resistance to chemotherapy, and regulation of gene and protein expression in pancreatic tumor lines is examined. Methionine stress prevents successful mitosis and promotes cell cycle arrest and accumulation of cells with multiple micronuclei with decondensed chromatin. Inhibition of mitosis correlates with CDK1 down-regulation and/or inhibition of its function by Tyr(15) phosphorylation or Thr(161) dephosphorylation. Inhibition of cell cycle progression correlates with loss of hyperphosphorylated Rb and up-regulation of p21 via p53 and/or transforming growth factor-beta (TGF-beta) activation depending on p53 status. Although methionine stress-induced toxicity is not solely dependent on p53, the gain in p21 and loss in CDK1 transcription are more enhanced in wild-type p53 tumors. Up-regulation of SMAD7, a TGF-beta signaling inhibitor, suggests that SMAD7 does not restrict the TGF-beta-mediated induction of p21, although it may prevent up-regulation of p27. cDNA oligoarray analysis indicated a pleiotropic response to methionine stress. Cell cycle and mitotic arrest is in agreement with up-regulation of NF2, ETS2, CLU, GADD45alpha, GADD45beta, and GADD45gamma and down-regulation of AURKB, TOP2A, CCNA, CCNB, PRC1, BUB1, NuSAP, IFI16, and BRCA1. Down-regulation of AREG, AGTR1, M-CSF, and EGF, IGF, and VEGF receptors and up-regulation of GNA11 and IGFBP4 signify loss of growth factor support. PIN1, FEN1, and cABL up-regulation and LMNB1, AREG, RhoB, CCNG, TYMS, F3, and MGMT down-regulation suggest that methionine stress sensitizes the tumor cells to DNA-alkylating drugs, 5-fluorouracil, and radiation. Increased sensitivity of pancreatic tumor cell lines to temozolomide is shown under methionine stress conditions and is attributed in part to diminished O(6)-methylguanine-DNA methyltransferase and possibly to inhibition of the cell cycle progression.

  5. Proton Therapy Verification with PET Imaging

    OpenAIRE

    Zhu, Xuping; Fakhri, Georges El

    2013-01-01

    Proton therapy is very sensitive to uncertainties introduced during treatment planning and dose delivery. PET imaging of proton induced positron emitter distributions is the only practical approach for in vivo, in situ verification of proton therapy. This article reviews the current status of proton therapy verification with PET imaging. The different data detecting systems (in-beam, in-room and off-line PET), calculation methods for the prediction of proton induced PET activity distributions...

  6. Methionine sulfoxide reductase A: Structure, function and role in ocular pathology

    Institute of Scientific and Technical Information of China (English)

    Parameswaran; G; Sreekumar; David; R; Hinton; Ram; Kannan

    2011-01-01

    Methionine is a highly susceptible amino acid that can be oxidized to S and R diastereomeric forms of methionine sulfoxide by many of the reactive oxygen species generated in biological systems. Methionine sulfoxide reductases (Msrs) are thioredoxin-linked enzymes involved in the enzymatic conversion of methionine sulfoxide to methionine. Although MsrA and MsrB have the same function of methionine reduction, they differ in substrate specifi city, active site composition, subcellular localization, and evolution. MsrA has been localized in different ocular regions and is abundantly expressed in the retina and in retinal pigment epithelial (RPE) cells. MsrA protects cells from oxidative stress. Overexpression of MsrA increases resistance to cell death, while silencing or knocking down MsrA decreases cell survival; events that are mediated by mitochondria. MsrA participates in protein-protein interaction with several other cellular proteins. The interaction of MsrAwith α-crystallins is of utmost importance given the known functions of the latter in protein folding, neuroprotection, and cell survival. Oxidation of methionine residues in α-crystallins results in loss of chaperone function and possibly its antiapoptotic properties. Recent work from our laboratory has shown that MsrA is co-localized with αA and αB crystallins in the retinal samples of patients with age-related macular degen- eration. We have also found that chemically induced hypoxia regulates the expression of MsrA and MsrB2 in human RPE cells. Thus, MsrA is a critical enzyme that participates in cell and tissue protection, and its interaction with other proteins/growth factors may provide a target for therapeutic strategies to prevent degenerative diseases.

  7. Structural and functional characteristics of cGMP-dependent methionine oxidation in Arabidopsis thaliana proteins

    KAUST Repository

    Marondedze, Claudius

    2013-01-05

    Background: Increasing structural and biochemical evidence suggests that post-translational methionine oxidation of proteins is not just a result of cellular damage but may provide the cell with information on the cellular oxidative status. In addition, oxidation of methionine residues in key regulatory proteins, such as calmodulin, does influence cellular homeostasis. Previous findings also indicate that oxidation of methionine residues in signaling molecules may have a role in stress responses since these specific structural modifications can in turn change biological activities of proteins. Findings. Here we use tandem mass spectrometry-based proteomics to show that treatment of Arabidopsis thaliana cells with a non-oxidative signaling molecule, the cell-permeant second messenger analogue, 8-bromo-3,5-cyclic guanosine monophosphate (8-Br-cGMP), results in a time-dependent increase in the content of oxidised methionine residues. Interestingly, the group of proteins affected by cGMP-dependent methionine oxidation is functionally enriched for stress response proteins. Furthermore, we also noted distinct signatures in the frequency of amino acids flanking oxidised and un-oxidised methionine residues on both the C- and N-terminus. Conclusions: Given both a structural and functional bias in methionine oxidation events in response to a signaling molecule, we propose that these are indicative of a specific role of such post-translational modifications in the direct or indirect regulation of cellular responses. The mechanisms that determine the specificity of the modifications remain to be elucidated. 2013 Marondedze et al.; licensee BioMed Central Ltd.

  8. Improved automated synthesis and preliminary animal PET/CT imaging of 11C-acetate

    International Nuclear Information System (INIS)

    To study a simple and rapid automated synthetic technology of 11C-acetate (11C- AC), automated synthesis of 11C-AC was performed by carboxylation of MeMgBr/tetrahydrofuran (THF) on a polyethylene loop with 11C-CO2, followed by hydrolysis and purification on solid-phase extraction cartridges using a 11C-Choline/Methionine synthesizer made in China. A high and reproducible radiochemical yield of above 40% (decay corrected) was obtained within the whole synthesis time about 8 min from 11C-CO2. The radiochemical purity of 11C-AC was over 95%. The novel, simple and rapid on-column hydrolysis-purification procedure should adaptable to the fully automated synthesis of 11C-AC at several commercial synthesis module. 11C-AC injection produced by the automated procedure is safe and effective, and can be used for PET imaging of animals and humans. (authors)

  9. Sulfur-containing amino acid methionine as the precursor of volatile organic sulfur compounds in algea-induced black bloom

    Institute of Scientific and Technical Information of China (English)

    Xin Lu; Chengxin Fan; Wei He; Jiancai Deng; Hongbin Yin

    2013-01-01

    After the application of methionine,a progressive and significant increase occurred in five volatile organic sulfur compounds (VOSCs):methanethiol (MeSH),dimethyl sulfide (DMS),dimethyl disulfide (DMDS),dimethyl trisulfide (DMTS) and dimethyl tetrasulfide (DMTeS).Even in the untreated control without a methionine addition,methionine and its catabolites (VOSCs,mainly DMDS) were found in considerable amounts that were high enough to account for the water's offensive odor.However,blackening only occurred in two methionine-amended treatments.The VOSCs production was observed to precede black color development,and the reaching of a peak value for total VOSCs was often followed by water blackening.The presence of glucose stimulated the degradation of methionine while postponing the occurrence of the black color and inhibiting the production of VOSCs.In addition,DMDS was found to be the most abundant species produced after the addition of methionine alone,and DMTeS appeared to be the most important compound produced after the addition of methionine+glucose.These results suggest that methionine acted as an important precursor of the VOSCs in lakes suffering from algea-induced black bloom.The existence of glucose may change the transformation pathway of methionine into VOSCs to form larger molecular weight compounds,such as DMTS and DMTeS.

  10. Methionine restriction inhibits chemically-induced malignant transformation in the BALB/c 3T3 cell transformation assay.

    Science.gov (United States)

    Nicken, Petra; Empl, Michael T; Gerhard, Daniel; Hausmann, Julia; Steinberg, Pablo

    2016-09-01

    High consumption of red meat entails a higher risk of developing colorectal cancer. Methionine, which is more frequently a component of animal proteins, and folic acid are members of the one carbon cycle and as such important players in DNA methylation and cancer development. Therefore, dietary modifications involving altered methionine and folic acid content might inhibit colon cancer development. In the present study, the BALB/c 3T3 cell transformation assay was used to investigate whether methionine and folic acid are able to influence the malignant transformation of mouse fibroblasts after treatment with the known tumour initiator 3-methylcholanthrene. Three different methionine concentrations (representing a -40%, a "normal" and a +40% cell culture medium concentration, respectively) and two different folic acid concentrations (6 and 20 μM) were thereby investigated. Methionine restriction led to a decrease of type III foci, while enhancement of both methionine and folic acid did not significantly increase the cell transformation rate. Interestingly, the focus-lowering effect of methionine was only significant in conjunction with an elevated folic acid concentration. In summary, we conclude that the malignant transformation of mouse fibroblasts is influenced by methionine levels and that methionine restriction could be a possible approach to reduce cancer development.

  11. Downregulation of Cdc6 and pre-replication complexes in response to methionine stress in breast cancer cells.

    Science.gov (United States)

    Booher, Keith; Lin, Da-Wei; Borrego, Stacey L; Kaiser, Peter

    2012-12-01

    Methionine and homocysteine are metabolites in the transmethylation pathway leading to synthesis of the methyl-donor S-adenosylmethionine (SAM). Most cancer cells stop proliferating during methionine stress conditions, when methionine is replaced in the growth media by its immediate metabolic precursor homocysteine (Met-Hcy+). Non-transformed cells proliferate in Met-Hcy+ media, making the methionine metabolic requirement of cancer cells an attractive target for therapy, yet there is relatively little known about the molecular mechanisms governing the methionine stress response in cancer cells. To study this phenomenon in breast cancer cells, we selected methionine-independent-resistant cell lines derived from MDAMB468 breast cancer cells. Resistant cells grew normally in Met-Hcy+ media, whereas their parental MDAMB468 cells rapidly arrest in the G 1 phase. Remarkably, supplementing Met-Hcy+ growth media with S-adenosylmethionine suppressed the cell proliferation defects, indicating that methionine stress is a consequence of SAM limitation rather than low amino acid concentrations. Accordingly, mTORC1 activity, the primary effector responding to amino acid limitation, remained high. However, we found that levels of the replication factor Cdc6 decreased and pre-replication complexes were destabilized in methionine-stressed MDAMB468 but not resistant cells. Our study characterizes metabolite requirements and cell cycle responses that occur during methionine stress in breast cancer cells and helps explain the metabolic uniqueness of cancer cells.

  12. Methionine restriction inhibits chemically-induced malignant transformation in the BALB/c 3T3 cell transformation assay.

    Science.gov (United States)

    Nicken, Petra; Empl, Michael T; Gerhard, Daniel; Hausmann, Julia; Steinberg, Pablo

    2016-09-01

    High consumption of red meat entails a higher risk of developing colorectal cancer. Methionine, which is more frequently a component of animal proteins, and folic acid are members of the one carbon cycle and as such important players in DNA methylation and cancer development. Therefore, dietary modifications involving altered methionine and folic acid content might inhibit colon cancer development. In the present study, the BALB/c 3T3 cell transformation assay was used to investigate whether methionine and folic acid are able to influence the malignant transformation of mouse fibroblasts after treatment with the known tumour initiator 3-methylcholanthrene. Three different methionine concentrations (representing a -40%, a "normal" and a +40% cell culture medium concentration, respectively) and two different folic acid concentrations (6 and 20 μM) were thereby investigated. Methionine restriction led to a decrease of type III foci, while enhancement of both methionine and folic acid did not significantly increase the cell transformation rate. Interestingly, the focus-lowering effect of methionine was only significant in conjunction with an elevated folic acid concentration. In summary, we conclude that the malignant transformation of mouse fibroblasts is influenced by methionine levels and that methionine restriction could be a possible approach to reduce cancer development. PMID:27427305

  13. Definitive Endoderm Differentiation of Human Embryonic Stem Cells Combined with Selective Elimination of Undifferentiated Cells by Methionine Deprivation.

    Science.gov (United States)

    Tsuyama, Tomonori; Shiraki, Nobuaki; Kume, Shoen

    2016-01-01

    Human embryonic stem cells (ESCs) show a characteristic feature in that they are highly dependent on methionine metabolism. Undifferentiated human ESCs cannot survive under condition that methionine is deprived from culture medium. We describe here a procedure for definitive endoderm differentiation from human ESCs, in which human ESCs are subject to 10 days' (d) differentiation combined with methionine deprivation between differentiation days (d) 8 to (d) 10. Methionine deprivation results in elimination of undifferentiated cells from the culture with no significant loss of definitive endoderm cells, as compared to those cultured under complete condition throughout the whole culture period.

  14. LAT1 targeted delivery of methionine based imaging probe derived from M(III) metal ions for early diagnosis of proliferating tumours using molecular imaging modalities.

    Science.gov (United States)

    Hazari, Puja Panwar; Prakash, Surbhi; Meena, Virendra K; Jaswal, Ambika; Khurana, Harleen; Mishra, Surabhi Kirti; Bhonsle, Hemanth Kumar; Singh, Lokendra; Mishra, Anil K

    2015-01-01

    We investigated the potential of DTPA-bis(Methionine), a target specific amino acid based probe for detection of L-type amino acid transporters (LAT1) known to over express in proliferating tumours using multimodality imaging. The ligand, DTPA-bis(Met) was readily converted to lanthanide complexes and was found capable of targeting cancer cells using multimodality imaging. DTPA-bis(Met) complexes were synthesized and characterized by mass spectroscopy. MR longitudinal relaxivity, r₁ = 4.067 ± 0.31 mM⁻¹s⁻¹ and transverse relaxivity, r₂ = 8.61 ± 0.07 mM⁻¹s⁻¹ of Gd(III)-DTPA-bis(Met) were observed at pH 7.4 at 7 T. Bright, localized fluorescence of Eu(III)-DTPA-bis(Met) was observed with standard microscopy and displacement studies indicated ligand functionality. K(D) value determined for Eu(III)-DTPA-bis(Met) on U-87 MG cells was found to be 17.3 pM and showed appreciable fluorescence within the cells. Radio HPLC showed a radiochemical purity more than 95% (specific activity = 400-500 MBq/μmol, labelling efficiency 78 %) for ⁶⁸Ga(III)-DTPA-bis(Met). Pre-treatment of xenografted U-87 MG athymic mice with ⁶⁸Ga(III)-DTPA-bis(Met) following unlabelled L-methionine administration reduced tumour uptake by 10-folds in Micro PET. These data support the specific binding of ⁶⁸Ga(III)-DTPA-bis(Met) to the LAT1 transporter. To summarize, this agent possesses high stability in biological environment and exhibits effective interaction with its LAT1 transporters giving high accumulation in tumour area, excellent tumour/non-tumour ratio and low non-specific retention in vivo.

  15. PET Metabolic Biomarkers for Cancer

    Science.gov (United States)

    Croteau, Etienne; Renaud, Jennifer M.; Richard, Marie Anne; Ruddy, Terrence D.; Bénard, François; deKemp, Robert A.

    2016-01-01

    The body’s main fuel sources are fats, carbohydrates (glucose), proteins, and ketone bodies. It is well known that an important hallmark of cancer cells is the overconsumption of glucose. Positron emission tomography (PET) imaging using the glucose analog 18F-fluorodeoxyglucose (18F-FDG) has been a powerful cancer diagnostic tool for many decades. Apart from surgery, chemotherapy and radiotherapy represent the two main domains for cancer therapy, targeting tumor proliferation, cell division, and DNA replication—all processes that require a large amount of energy. Currently, in vivo clinical imaging of metabolism is performed almost exclusively using PET radiotracers that assess oxygen consumption and mechanisms of energy substrate consumption. This paper reviews the utility of PET imaging biomarkers for the detection of cancer proliferation, vascularization, metabolism, treatment response, and follow-up after radiation therapy, chemotherapy, and chemotherapy-related side effects.

  16. PET and SPECT in neurology

    Energy Technology Data Exchange (ETDEWEB)

    Dierckx, Rudi A.J.O. [Groningen University Medical Center (Netherlands). Dept. of Nuclear Medicine and Molecular Imaging; Ghent Univ. (Belgium). Dept. of Radiology and Nuclear Medicine; Vries, Erik F.J. de; Waarde, Aren van [Groningen University Medical Center (Netherlands). Dept. of Nuclear Medicine and Molecular Imaging; Otte, Andreas (ed.) [Univ. of Applied Sciences Offenburg (Germany). Faculty of Electrical Engineering and Information Technology

    2014-07-01

    PET and SPECT in Neurology highlights the combined expertise of renowned authors whose dedication to the investigation of neurological disorders through nuclear medicine technology has achieved international recognition. Classical neurodegenerative disorders are discussed as well as cerebrovascular disorders, brain tumors, epilepsy, head trauma, coma, sleeping disorders, and inflammatory and infectious diseases of the CNS. The latest results in nuclear brain imaging are detailed. Most chapters are written jointly by a clinical neurologist and a nuclear medicine specialist to ensure a multidisciplinary approach. This state-of-the-art compendium will be valuable to anybody in the field of neuroscience, from the neurologist and the radiologist/nuclear medicine specialist to the interested general practitioner and geriatrician. It is the second volume of a trilogy on PET and SPECT imaging in the neurosciences, the other volumes covering PET and SPECT in psychiatry and in neurobiological systems.

  17. PET and SPECT in neurology

    International Nuclear Information System (INIS)

    PET and SPECT in Neurology highlights the combined expertise of renowned authors whose dedication to the investigation of neurological disorders through nuclear medicine technology has achieved international recognition. Classical neurodegenerative disorders are discussed as well as cerebrovascular disorders, brain tumors, epilepsy, head trauma, coma, sleeping disorders, and inflammatory and infectious diseases of the CNS. The latest results in nuclear brain imaging are detailed. Most chapters are written jointly by a clinical neurologist and a nuclear medicine specialist to ensure a multidisciplinary approach. This state-of-the-art compendium will be valuable to anybody in the field of neuroscience, from the neurologist and the radiologist/nuclear medicine specialist to the interested general practitioner and geriatrician. It is the second volume of a trilogy on PET and SPECT imaging in the neurosciences, the other volumes covering PET and SPECT in psychiatry and in neurobiological systems.

  18. The rise and fall of PET and PET/CT. A German perspective

    International Nuclear Information System (INIS)

    PET is being considered a diagnostic commodity in clinical practice worldwide and thus receives increasing attention by health insurances and governmental organizations. In Germany, however, neither PET nor PET/CT are subject to reimbursement. This renders clinical PET and PET/CT imaging a challenge both in general hospital environment and in private practice. This article describes briefly these challenges, which are not solely related to turf battles and associated costs. (orig.)

  19. THE CHARACTERISTICS OF EEC PET INSTRUMENTATION

    NARCIS (Netherlands)

    PAANS, AMJ

    1991-01-01

    As a result of a Guide-Questionnaire distributed among all European PET centers an inventory of the European PET instrumentation has become available in a data base. An overview and analysis of the European PET equipment, cyclotrons, scanners and software, together with some global information on th

  20. 36 CFR 13.1234 - Pets.

    Science.gov (United States)

    2010-07-01

    ... 36 Parks, Forests, and Public Property 1 2010-07-01 2010-07-01 false Pets. 13.1234 Section 13.1234 Parks, Forests, and Public Property NATIONAL PARK SERVICE, DEPARTMENT OF THE INTERIOR NATIONAL PARK... § 13.1234 Pets. Possessing a pet in the BCDA is prohibited....

  1. Kinetic modeling in PET imaging of hypoxia

    DEFF Research Database (Denmark)

    Li, Fan; Jørgensen, Jesper Tranekjær; Hansen, Anders E;

    2014-01-01

    be used for non-invasive mapping of tissue oxygenation in vivo and several hypoxia specific PET tracers have been developed. Evaluation of PET data in the clinic is commonly based on visual assessment together with semiquantitative measurements e.g. standard uptake value (SUV). However, dynamic PET...

  2. Saying Goodbye: Pet Loss and Its Implications

    Science.gov (United States)

    Duffey, Thelma

    2005-01-01

    Pets can be loyal, loving, and entertaining members of a family. Their deaths are generally experienced as painful losses by the people who love them, even though the grief experience is often culturally disenfranchised. In this manuscript, we discuss the role that pets can play in a person's life; the effects that pet loss can have on the people…

  3. Understanding advertising in pet nutrition.

    OpenAIRE

    Brown, R G

    1994-01-01

    Advertising is part of the effort to attract attention of consumers to products, in this case, pet foods. It is generally benign in its effect, but it can be misleading, although rarely deliberately so. It uses a specialized vocabulary, which must be mastered if one is to understand what is intended. For all of the expense and effort, advertising figures directly in relatively few decisions to purchase. Its main intention is to call our attention to a particular pet food and to give that prod...

  4. PET and PET/CT in malignant melanoma

    International Nuclear Information System (INIS)

    The advantages that it has the PET/CT are: 1. It diminishes mainly positive false lesions. It identifies physiologic accumulate places. 2. It diminishes in smaller grade false negative. Small injuries. Injuries with low grade concentration. Injure on intense activity areas. 3. Precise anatomical localization of accumulate places. 4. Reduction of the acquisition time. (Author)

  5. Competitive advantage of PET/MRI.

    Science.gov (United States)

    Jadvar, Hossein; Colletti, Patrick M

    2014-01-01

    Multimodality imaging has made great strides in the imaging evaluation of patients with a variety of diseases. Positron emission tomography/computed tomography (PET/CT) is now established as the imaging modality of choice in many clinical conditions, particularly in oncology. While the initial development of combined PET/magnetic resonance imaging (PET/MRI) was in the preclinical arena, hybrid PET/MR scanners are now available for clinical use. PET/MRI combines the unique features of MRI including excellent soft tissue contrast, diffusion-weighted imaging, dynamic contrast-enhanced imaging, fMRI and other specialized sequences as well as MR spectroscopy with the quantitative physiologic information that is provided by PET. Most evidence for the potential clinical utility of PET/MRI is based on studies performed with side-by-side comparison or software-fused MRI and PET images. Data on distinctive utility of hybrid PET/MRI are rapidly emerging. There are potential competitive advantages of PET/MRI over PET/CT. In general, PET/MRI may be preferred over PET/CT where the unique features of MRI provide more robust imaging evaluation in certain clinical settings. The exact role and potential utility of simultaneous data acquisition in specific research and clinical settings will need to be defined. It may be that simultaneous PET/MRI will be best suited for clinical situations that are disease-specific, organ-specific, related to diseases of the children or in those patients undergoing repeated imaging for whom cumulative radiation dose must be kept as low as reasonably achievable. PET/MRI also offers interesting opportunities for use of dual modality probes. Upon clear definition of clinical utility, other important and practical issues related to business operational model, clinical workflow and reimbursement will also be resolved.

  6. Metabolic engineering of Corynebacterium glutamicum strain ATCC13032 to produce L-methionine.

    Science.gov (United States)

    Qin, Tianyu; Hu, Xiaoqing; Hu, Jinyu; Wang, Xiaoyuan

    2015-01-01

    L-Methionine-producing strain QW102/pJYW-4-hom(m) -lysC(m) -brnFE was developed from Corynebacterium glutamicum strain ATCC13032, using metabolic engineering strategies. These strategies involved (i) deletion of the gene thrB encoding homoserine kinase to increase the precursor supply, (ii) deletion of the gene mcbR encoding the regulator McbR to release the transcriptional repression to various genes in the l-methionine biosynthetic pathway, (iii) overexpression of the gene lysC(m) encoding feedback-resistant aspartate kinase and the gene hom(m) encoding feedback-resistant homoserine dehydrogenase to further increase the precursor supply, and (iv) overexpression of the gene cluster brnF and brnE encoding the export protein complex BrnFE to increase extracellular l-methionine concentration. QW102/pJYW-4-hom(m) -lysC(m) -brnFE produced 42.2 mM (6.3 g/L) l-methionine after 64-H fed-batch fermentation. These results suggest that l-methionine-producing strains can be developed from wild-type C. glutamicum strains by rationally metabolic engineering.

  7. Effect of methionine and glucosamine conjugation on the anticancer activity of aromatic dinitrobenzamide mustards

    Indian Academy of Sciences (India)

    Karmakar Subhendu; Sudipta Bhattacharyya; Arindam Mukherjee

    2016-03-01

    Certain nutrients viz.,glucose and methionine are consumed more by cancer cells. Hence, an anticancer agent conjugated to them may render more toxicity in cancer cells due to higher uptake. To probe this effect, methionine and glucosamine were conjugated to a series of well-known aromatic dinitrobenzamide mustards. The in vitro cytotoxicity studies performed to probe the effect of such conjugation showed that the conjugation of methionine and glucosamine to one of the dinitrobenzamide mustard led to more toxicity selectively in human breast adenocarcinoma (MCF-7) cell lines. However, effect of functionalization cannot be generalized. Hypoxia based studies showed that IC50 value did not show much change from normoxic condition which is encouraging as many drugs deactivate in hypoxia. Among the glucosamine and methionine conjugated dinitrobenzamide mustards, the methionine conjugated aromatic dinitrobenzamide mustard of 2-chlorobenzoic acid is the most effective one. It acts by inducing apoptosis through G2/M phase arrest and encouragingly, is much less toxic to nontumorigenic human embryonic kidney (HEK-293T) and mouse embryonic fibroblast (NIH 3T3) cell lines in vitro.

  8. A Methionine-Induced Animal Model of Schizophrenia: Face and Predictive Validity

    Science.gov (United States)

    Wang, Lien; Alachkar, Amal; Sanathara, Nayna; Belluzzi, James D.; Wang, Zhiwei

    2015-01-01

    Background: Modulating the methylation process induces broad biochemical changes, some of which may be involved in schizophrenia. Methylation is in particular central to epigenesis, which is also recognized as a factor in the etiology of schizophrenia. Because methionine administration to patients with schizophrenia has been reported to exacerbate their psychotic symptoms and because mice treated with methionine exhibited social deficits and prepulse inhibition impairment, we investigated whether methionine administration could lead to behavioral changes that reflect schizophrenic symptoms in mice. Methods: l-Methionine was administered to mice twice a day for 7 days. Results: We found that this treatment induces behavioral responses that reflect the 3 types of schizophrenia-like symptoms (positive, negative, or cognitive deficits) as monitored in a battery of behavioral assays (locomotion, stereotypy, social interaction, forced swimming, prepulse inhibition, novel object recognition, and inhibitory avoidance). Moreover, these responses were differentially reversed by typical haloperidol and atypical clozapine antipsychotics in ways that parallel their effects in schizophrenics. Conclusion: We thus propose the l-methionine treatment as an animal model recapitulating several symptoms of schizophrenia. We have established the face and predictive validity for this model. Our model relies on an essential natural amino acid and on an intervention that is relatively simple and time effective and may offer an additional tool for assessing novel antipsychotics. PMID:25991655

  9. Tumor therapy by deprivation of L-methionine: rationale and results.

    Science.gov (United States)

    Kreis, W

    1979-06-01

    Published reports indicate that normal rodent cells can grow in medium containing either L-methionine or L-homocysteine, whereas malignant rodent cells have an absolute requirement for L-methionine. Our studies with two normal human cell lines (fetal lung fibroblasts and bladder epithelial cells) exhibit equal growth in media containing either L-methionine or L-homocysteine. The same is true for five malignant human cell lines (carcinoma of the cervix [HeLa], adenocarcinoma of the breast [AlAb], acute lymphoblastic leukemia [MOLT-3], Wilms' tumor [SK-NEP-1], and reticulum cell sarcoma [T-77], whereas four other malignant cell lines (adenocarcinoma of the breast [SK-BR-2-III], the two lymphoblastic leukemias [CCRF-HSB-2 and CCRF-SB], and a neuroblastoma [SK-N-MC]) have absolute requirements for L-methionine. Two malignant cell lines, an adenocarcinoma of the lung (A549) and an adenocarcinoma of the pancreas (Capan-1), showed restricted growth under the experimental conditions used. L-Methionlinase (L-methionine-alpha-deamino-gamma-mercaptomethane-lyase, EC 4.4.1.11) at a concentration of 0.1 unit/ml leads to complete growth inhibition of cell cultures of both the normal human fetal lung fibroblasts (F-136-35-56) and the acute lymphoblastic leukemia (CCRF-HSB-2). L-Homocysteine-thiolactone in medium containing L-methioninase could partly "rescue" the normal but not the malignant cells.

  10. Cytotoxic effects of methionine alkyl esters and amides in normal and neoplastic cell lines.

    Science.gov (United States)

    Clement, M A; Chapman, J M; Roberts, J

    1989-06-01

    Homologous series of L-methionine alkyl ester hydrochlorides and tosylates were synthesized and evaluated for in vitro growth inhibitory activity in Meth A sarcoma. Cytotoxicity, as determined by [3H]thymidine incorporation, was found to be directly proportional to alkyl chain length and surface tension lowering activity. L-Methionine decyl and dodecyl ester hydrochlorides possessed optimum cytotoxic activity (IC50 = 29, 28 microM) which was not reversible by the addition of L-methionine. Surface tension of a 50 microM solution of the decyl and dodecyl ester hydrochlorides were 35.4 and 32.7 dyn/cm, respectively. The corresponding decyl and dodecyl ester tosylates and amide hydrochlorides were less active. The N-t-butoxycarbonyl analogues were essentially inactive, demonstrating the necessity of an unsubstituted and/or potentially cationic amino group. Methionine dependence characteristics and cytotoxicity were also determined for three human (IMR-90, LX-1, MCF7) and four additional murine (L1210, L5178Y, 3T3, SV-T2) cell lines. The human cell lines Meth A, LX-1, and SV-T2 were found to be methionine independent. The LX-1 tumor cell line and the SV-T2 transformed line exhibited two to four times more sensitivity to the cytotoxic and cytolytic properties of the decyl and dodecyl ester hydrochlorides than their normal counterparts. The dodecyl amide hydrochloride derivative demonstrated enhanced cytotoxic activity in vivo relative to the corresponding ester, possibly due to decreased metabolic hydrolysis.

  11. Determination of the specific activities of methionine sulfoxide reductase A and B by capillary electrophoresis.

    Science.gov (United States)

    Uthus, Eric O

    2010-06-01

    A capillary electrophoresis (CE) method for the determination of methionine sulfoxide reductase A and methionine sulfoxide reductase B activities in mouse liver is described. The method is based on detection of the 4-(dimethylamino)azobenzene-4'-sulfonyl derivative of l-methionine (dabsyl Met), the product of the enzymatic reactions when either dabsyl l-methionine S-sulfoxide or dabsyl l-methionine R-sulfoxide is used as a substrate. The method provides baseline resolution of the substrates and, therefore, can be used to easily determine the purity of the substrates. The method is rapid ( approximately 20min sample to sample), requires no column regeneration, and uses very small amounts of buffers. Separation was performed by using a 75-mum internal diameter polyimide-coated fused silica capillary (no inside coating) with 60cm total length (50cm to the detector window). Samples were separated at 22.5kV, and the separation buffer was 25mM KH(2)PO(4) (pH 8.0) containing 0.9ml of N-lauroylsarcosine (sodium salt, 30% [w/v] solution) per 100ml of buffer. Prior to use, the capillary was conditioned with the same buffer that also contained 25mM sodium dodecyl sulfate. The CE method is compared with high-performance liquid chromatography (HPLC) as determined by comparing results from measurements of hepatic enzyme activities in mice fed either deficient or adequate selenium. PMID:20167203

  12. Parasites suppress immune-enhancing effect of methionine in nestling great tits.

    Science.gov (United States)

    Wegmann, Michèle; Voegeli, Beatrice; Richner, Heinz

    2015-01-01

    After birth, an organism needs to invest both in somatic growth and in the development of efficient immune functions to counter the effects of pathogens, and hence an investment trade-off is predicted. To explore this trade-off, we simultaneously exposed nestling great tits (Parus major) to a common ectoparasite, while stimulating immune function. Using a 2 × 2 experimental design, we first infested half of the nests with hen fleas (Ceratophyllus gallinae) on day 3 post-hatch and later, on day 9-13 post-hatch, and then supplemented half of the nestlings within each nest with an immuno-enhancing amino acid (methionine). We then assessed the non-specific immune response by measuring both the inflammatory response to a lipopolysaccharide (LPS) and assessing the levels of acute phase proteins (APP). In parasite-infested nestlings, methionine had a negative effect on body mass close to fledging. Methionine had an immune-enhancing effect in the absence of ectoparasites only. The inflammatory response to LPS was significantly lower in nestlings infested with fleas and was also lower in nestlings supplemented with methionine. These patterns of immune responses suggest an immunosuppressive effect of ectoparasites that could neutralise the immune-enhancing effect of methionine. Our study thus suggests that the trade-off between investment in life history traits and immune function is only partly dependent on available resources, but shows that parasites may influence this trade-off in a more complex way, by also inhibiting important physiological functions.

  13. Intermediates in the recycling of 5-methylthioribose to methionine in fruits.

    Science.gov (United States)

    Kushad, M M; Richardson, D G; Ferro, A J

    1983-10-01

    The recycling of 5-methylthioribose (MTR) to methionine in avocado (Persea americana Mill, cv Hass) and tomato (Lycopersicum esculentum Mill, cv unknown) was examined. [(14)CH(3)]MTR was not metabolized in cell free extract from avocado fruit. Either [(14)CH(3)]MTR plus ATP or [(14)CH(3)]5-methylthioribose-1-phosphate (MTR-1-P) alone, however, were metabolized to two new products by these extracts. MTR kinase activity has previously been detected in these fruit extracts. These data indicate that MTR must be converted to MTR-1-P by MTR kinase before further metabolism can occur. The products of MTR-1-P metabolism were tentatively identified as alpha-keto-gamma-methylthiobutyric acid (alpha-KMB) and alpha-hydroxy-gamma-methylthiobutyric acid (alpha-HMB) by chromatography in several solvent systems. [(35)S]alpha-KMB was found to be further metabolized to methionine and alpha-HMB by these extracts, whereas alpha-HMB was not. However, alpha-HMB inhibited the conversion of alpha-KMB to methionine. Both [U-(14)C]alpha-KMB and [U-(14)C]methionine, but not [U-(14)C]alpha-HMB, were converted to ethylene in tomato pericarp tissue. In addition, aminoethoxyvinylglycine inhibited the conversion of alpha-KMB to ethylene. These data suggest that the recycling pathway leading to ethylene is MTR --> MTR-1-P --> alpha-KMB --> methionine --> S-adenosylmethionine --> 1-aminocyclopropane-1-carboxylic acid --> ethylene.

  14. Difference in brain distributions of carbon 11-labeled 4-hydroxy-2(1H)-quinolones as PET radioligands for the glycine-binding site of the NMDA ion channel

    Energy Technology Data Exchange (ETDEWEB)

    Fuchigami, Takeshi [Graduate School of Pharmaceutical Sciences, Kyushu University, Higashi-ku, Fukuoka 812-8582 (Japan); Photon Medical Research Center, Hamamatsu University School of Medicine, Hamamatsu 431-3192 (Japan); Haradahira, Terushi [Molecular Imaging Center, National Institute of Radiological Sciences, Inage-ku, Chiba 263-8555 (Japan)], E-mail: terushi@niu.ac.jp; Fujimoto, Noriko [Graduate School of Pharmaceutical Sciences, Kyushu University, Higashi-ku, Fukuoka 812-8582 (Japan); Okauchi, Takashi; Maeda, Jun; Suzuki, Kazutoshi; Suhara, Tetsuya [Molecular Imaging Center, National Institute of Radiological Sciences, Inage-ku, Chiba 263-8555 (Japan); Yamamoto, Fumihiko; Sasaki, Shigeki; Mukai, Takahiro [Graduate School of Pharmaceutical Sciences, Kyushu University, Higashi-ku, Fukuoka 812-8582 (Japan); Yamaguchi, Hiroshi [Molecular Imaging Frontier Research Center, Hamamatsu University School of Medicine, Hamamatsu 431-3192 (Japan); Ogawa, Mikako [Photon Medical Research Center, Hamamatsu University School of Medicine, Hamamatsu 431-3192 (Japan); Magata, Yasuhiro [Photon Medical Research Center, Hamamatsu University School of Medicine, Hamamatsu 431-3192 (Japan); Molecular Imaging Frontier Research Center, Hamamatsu University School of Medicine, Hamamatsu 431-3192 (Japan); Maeda, Minoru [Graduate School of Pharmaceutical Sciences, Kyushu University, Higashi-ku, Fukuoka 812-8582 (Japan)

    2008-02-15

    High-affinity iodine- and ethyl-C-5 substituted analogs of 4-hydroxy-3-(3-[{sup 11}C]methoxyphenyl)-2(1H)-quinolone ([{sup 11}C]4HQ) were synthesized as new positron emission tomography radioligands for the glycine-binding sites of the N-methyl-D-aspartate (NMDA) ion channel. Although both radioligands showed high in vitro specific binding to rat brain slices, their binding characteristics were quite different from each other. 5-Ethyl-[{sup 11}C]4HQ (5Et-[{sup 11}C]4HQ) showed higher in vitro binding in the forebrain regions than in the cerebellum, bindings that were strongly inhibited by both glycine-site agonists and antagonists. In contrast, 5-iodo-[{sup 11}C]4HQ (5I-[{sup 11}C]4HQ) showed a homogeneous in vitro binding throughout the brain, which was inhibited by antagonists but not by agonists. This difference in in vitro binding between 5Et-[{sup 11}C]4HQ and 5I-[{sup 11}C]4HQ was quite similar to that previously observed between [{sup 11}C]L-703,717 and [{sup 11}C]4HQ, both glycine-site antagonists. In vivo brain uptakes of these {sup 11}C-labeled 4-hydroxyquinolones were examined in mice. Initial brain uptakes of 5Et- and 5I-[{sup 11}C]4HQ at 1 min after intravenous injections were comparable to that of [{sup 11}C]4HQ, but they were 1.3-2.1 times higher than that of [{sup 11}C]L-703,717. The treatment with an anticoagulant, warfarin, only slightly increased the initial uptakes of [{sup 11}C]4HQ and 5Et-[{sup 11}C]4HQ in contrast to [{sup 11}C]L-703,717. The in vivo regional brain distributions were slightly different between the two radioligands. Pretreatment with nonradioactive ligand (2 mg/kg) slightly inhibited the binding of 5Et-[{sup 11}C]4HQ (16-36% inhibition) but not that of 5I-[{sup 11}C]4HQ. In this study, it was found that a small structural change in [{sup 11}C]4HQ resulted in a major change in binding characteristics and distributions, suggesting the existence of two binding sites for [{sup 11}C]4-hydroxyquinolones on the NMDA ion channel - agonist-sensitive and agonist-insensitive (or antagonist-preferring) sites.

  15. The MiniPET: a didactic PET system

    Science.gov (United States)

    Pedro, R.; Silva, J.; Gurriana, L.; Silva, J. M.; Maio, A.; Soares Augusto, J.

    2013-03-01

    The MiniPET project aims to design and build a small PET system. It consists of two 4 × 4 matrices of 16 LYSO scintillator crystals and two PMTs with 16 channels resulting in a low cost system with the essential functionality of a clinical PET instrument. It is designed to illustrate the physics of the PET technique and to provide a didactic platform for the training of students and nuclear imaging professionals as well as for scientific outreach. The PET modules can be configured to test for the coincidence of 511 keV gamma rays. The model has a flexible mechanical setup [1] and can simulate 14 diferent ring geometries, from a configuration with as few as 18 detectors per ring (ring radius phi=51 mm), up to a geometry with 70 detectors per ring (phi=200 mm). A second version of the electronic system [2] allowed measurement and recording of the energy deposited in 4 detector channels by photons from a 137Cs radioactive source and by photons resulting of the annihilation of positrons from a 22Na radioactive source. These energy spectra are used for detector performance studies, as well as angular dependency studies. In this paper, the mechanical setup, the front-end high-speed analog electronics, the digital acquisition and control electronics implemented in a FPGA, as well as the data-transfer interface between the FPGA board and a host PC are described. Recent preliminary results obtained with the 4 active channels in the prototype are also presented.

  16. Synthesis and PET studies of [11C-cyano]letrozole (Femara), an aromatase inhibitor drug

    International Nuclear Information System (INIS)

    Introduction: Aromatase, a member of the cytochrome P450 family, converts androgens such as androstenedione and testosterone into estrone and estradiol, respectively. Letrozole (1-[bis-(4-cyanophenyl)methyl]-1H-1,2,4-triazole; Femara) is a high-affinity aromatase inhibitor (Ki=11.5 nM) that has Food and Drug Administration approval for breast cancer treatment. Here we report the synthesis of carbon-11-labeled letrozole and its assessment as a radiotracer for brain aromatase in the baboon. Methods: Letrozole and its precursor (4-[(4-bromophenyl)-1H-1,2,4-triazol-1-ylmethyl]benzonitrile) were prepared in a two-step synthesis from 4-cyanobenzyl bromide and 4-bromobenzyl bromide, respectively. The [11C]cyano group was introduced via tetrakis(triphenylphosphine)palladium(0)-catalyzed coupling of [11C]cyanide with the bromo precursor. Positron emission tomography (PET) studies in the baboon brain were carried out to assess regional distribution and kinetics, reproducibility of repeated measures and saturability. Log D, the free fraction of letrozole in plasma and the [11C-cyano]letrozole fraction in arterial plasma were also measured. Results: [11C-cyano]Letrozole was synthesized in 60 min with a radiochemical yield of 79-80%, with a radiochemical purity greater than 98% and a specific activity of 4.16±2.21 Ci/μmol at the end of bombardment (n=4). PET studies in the baboon revealed initial rapid and high uptake and initial rapid clearance, followed by slow clearance of carbon-11 from the brain, with no difference between brain regions. Brain kinetics was not affected by coinjection of unlabeled letrozole (0.1 mg/kg). The free fraction of letrozole in plasma was 48.9%, and log D was 1.84. Conclusion: [11C-cyano]Letrozole is readily synthesized via a palladium-catalyzed coupling reaction with [11C]cyanide. Although it is unsuitable as a PET radiotracer for brain aromatase, as revealed by the absence of regional specificity and saturability in brain regions such as

  17. Development of PET/MRI with insertable PET for simultaneous PET and MR imaging of human brain

    Energy Technology Data Exchange (ETDEWEB)

    Jung, Jin Ho; Choi, Yong, E-mail: ychoi.image@gmail.com; Jung, Jiwoong; Kim, Sangsu; Lim, Hyun Keong; Im, Ki Chun [Department of Electronic Engineering, Sogang University, 35 Baekbeom-ro, Mapo-gu, Seoul 121-742 (Korea, Republic of); Oh, Chang Hyun; Park, Hyun-wook [Department of Electrical Engineering, Korea Advanced Institute of Science and Technology, 291 Daehak-ro, Yuseong-gu, Daejeon 305-701 (Korea, Republic of); Kim, Kyung Min; Kim, Jong Guk [Korea Institute of Radiological and Medical Science, 75 Nowon-ro, Nowon-gu, Seoul 139-709 (Korea, Republic of)

    2015-05-15

    Purpose: The purpose of this study was to develop a dual-modality positron emission tomography (PET)/magnetic resonance imaging (MRI) with insertable PET for simultaneous PET and MR imaging of the human brain. Methods: The PET detector block was composed of a 4 × 4 matrix of detector modules, each consisting of a 4 × 4 array LYSO coupled to a 4 × 4 Geiger-mode avalanche photodiode (GAPD) array. The PET insert consisted of 18 detector blocks, circularly mounted on a custom-made plastic base to form a ring with an inner diameter of 390 mm and axial length of 60 mm. The PET gantry was shielded with gold-plated conductive fabric tapes with a thickness of 0.1 mm. The charge signals of PET detector transferred via 4 m long flat cables were fed into the position decoder circuit. The flat cables were shielded with a mesh-type aluminum sheet with a thickness of 0.24 mm. The position decoder circuit and field programmable gate array-embedded DAQ modules were enclosed in an aluminum box with a thickness of 10 mm and located at the rear of the MR bore inside the MRI room. A 3-T human MRI system with a Larmor frequency of 123.7 MHz and inner bore diameter of 60 cm was used as the PET/MRI hybrid system. A custom-made radio frequency (RF) coil with an inner diameter of 25 cm was fabricated. The PET was positioned between gradient and the RF coils. PET performance was measured outside and inside the MRI scanner using echo planar imaging, spin echo, turbo spin echo, and gradient echo sequences. MRI performance was also evaluated with and without the PET insert. The stability of the newly developed PET insert was evaluated and simultaneous PET and MR images of a brain phantom were acquired. Results: No significant degradation of the PET performance caused by MR was observed when the PET was operated using various MR imaging sequences. The signal-to-noise ratio of MR images was slightly degraded due to the PET insert installed inside the MR bore while the homogeneity was

  18. Development of PET/MRI with insertable PET for simultaneous PET and MR imaging of human brain

    International Nuclear Information System (INIS)

    Purpose: The purpose of this study was to develop a dual-modality positron emission tomography (PET)/magnetic resonance imaging (MRI) with insertable PET for simultaneous PET and MR imaging of the human brain. Methods: The PET detector block was composed of a 4 × 4 matrix of detector modules, each consisting of a 4 × 4 array LYSO coupled to a 4 × 4 Geiger-mode avalanche photodiode (GAPD) array. The PET insert consisted of 18 detector blocks, circularly mounted on a custom-made plastic base to form a ring with an inner diameter of 390 mm and axial length of 60 mm. The PET gantry was shielded with gold-plated conductive fabric tapes with a thickness of 0.1 mm. The charge signals of PET detector transferred via 4 m long flat cables were fed into the position decoder circuit. The flat cables were shielded with a mesh-type aluminum sheet with a thickness of 0.24 mm. The position decoder circuit and field programmable gate array-embedded DAQ modules were enclosed in an aluminum box with a thickness of 10 mm and located at the rear of the MR bore inside the MRI room. A 3-T human MRI system with a Larmor frequency of 123.7 MHz and inner bore diameter of 60 cm was used as the PET/MRI hybrid system. A custom-made radio frequency (RF) coil with an inner diameter of 25 cm was fabricated. The PET was positioned between gradient and the RF coils. PET performance was measured outside and inside the MRI scanner using echo planar imaging, spin echo, turbo spin echo, and gradient echo sequences. MRI performance was also evaluated with and without the PET insert. The stability of the newly developed PET insert was evaluated and simultaneous PET and MR images of a brain phantom were acquired. Results: No significant degradation of the PET performance caused by MR was observed when the PET was operated using various MR imaging sequences. The signal-to-noise ratio of MR images was slightly degraded due to the PET insert installed inside the MR bore while the homogeneity was

  19. Principles of PET/MR Imaging.

    Science.gov (United States)

    Disselhorst, Jonathan A; Bezrukov, Ilja; Kolb, Armin; Parl, Christoph; Pichler, Bernd J

    2014-05-12

    Hybrid PET/MR systems have rapidly progressed from the prototype stage to systems that are increasingly being used in the clinics. This review provides an overview of developments in hybrid PET/MR systems and summarizes the current state of the art in PET/MR instrumentation, correction techniques, and data analysis. The strong magnetic field requires considerable changes in the manner by which PET images are acquired and has led, among others, to the development of new PET detectors, such as silicon photomultipliers. During more than a decade of active PET/MR development, several system designs have been described. The technical background of combined PET/MR systems is explained and related challenges are discussed. The necessity for PET attenuation correction required new methods based on MR data. Therefore, an overview of recent developments in this field is provided. Furthermore, MR-based motion correction techniques for PET are discussed, as integrated PET/MR systems provide a platform for measuring motion with high temporal resolution without additional instrumentation. The MR component in PET/MR systems can provide functional information about disease processes or brain function alongside anatomic images. Against this background, we point out new opportunities for data analysis in this new field of multimodal molecular imaging. PMID:24819419

  20. Diseases Transmitted by Less Common House Pets.

    Science.gov (United States)

    Chomel, Bruno B

    2015-12-01

    Beside dogs and cats, the most common pets worldwide, an increasing number of pocket pets and exotic pets are making their way to more and more households, especially in North America and Europe. Although many of these animals make appropriate pets, they also can be a source of many zoonotic diseases, especially in young children and immunocompromised individuals. Some of these diseases can be life threatening, such as rabies, rat bite fever, and plague. Some others are quite common, because of the frequency of the pathogens harbored by these species, such as salmonellosis in reptiles and amphibians. Appropriate knowledge of the zoonotic agents carried by these "new" pet species is strongly recommended prior to acquiring pocket or exotic pets. Furthermore, adopting wildlife as pets is strongly discouraged, because it is always a risky action that can lead to major health issues. PMID:27337276

  1. SPECT og PET i neurobiologien

    DEFF Research Database (Denmark)

    Paulson, O.B.; Lassen, N.A.

    1997-01-01

    PET (positron emission tomography) and SPECT (single photon emission computed tomography) are isotopic methods in which the distribution is registered of radiolabelled tracers given in such small amounts that they are without effect on the organism or the organism's disposal of them. Thus, a series...

  2. Particle Accelerators for PET radionuclides

    DEFF Research Database (Denmark)

    Jensen, Mikael

    2012-01-01

    The requirements set for particle accelerators for production of radioactive isotopes for PET can easily be derived from first principles. The simple general need is for proton beams with energy in the region 10–20 MeV and current 20–100 microAmps. This is most reliably and cost-effectively achie......The requirements set for particle accelerators for production of radioactive isotopes for PET can easily be derived from first principles. The simple general need is for proton beams with energy in the region 10–20 MeV and current 20–100 microAmps. This is most reliably and cost...... different manufacturers will be discussed the light of what is actually needed for a given PET site operation. Alternatives to the conventional cyclotron have been proposed and tested but have at present very limited use. These alternatives will be discussed, as well as the future possibilities of supplying...... point of demand tracer production with very small cyclotrons of energy well below 10 MeV. The authors best advice at present for new PET sites is to negotiate for conventional cyclotron solutions from experienced manufacturers. It is the combined performance of cyclotron and target in terms of available...

  3. Diagnostic imaging of exotic pets

    International Nuclear Information System (INIS)

    Radiographic, ultrasonographic, and computed tomographic (CT) imaging are important diagnostic modalities in exotic pets. The use of appropriate radiographic equipment, film-screen combinations, and radiographic projections enhances the information obtained from radiographs. Both normal findings and common radiographic abnormalities are discussed. The use of ultrasonography and CT scanning for exotic small mammals and reptiles is described

  4. PET and SPECT in psychiatry

    International Nuclear Information System (INIS)

    Covers classical psychiatric disorders as well as other subjects such as suicide, sleep, eating disorders, and autism. Emphasis on a multidisciplinary approach. Written by internationally acclaimed experts. PET and SPECT in Psychiatry showcases the combined expertise of renowned authors whose dedication to the investigation of psychiatric disease through nuclear medicine technology has achieved international recognition. The classical psychiatric disorders as well as other subjects - such as suicide, sleep, eating disorders, and autism - are discussed and the latest results in functional neuroimaging are detailed. Most chapters are written jointly by a clinical psychiatrist and a nuclear medicine expert to ensure a multidisciplinary approach. This state of the art compendium will be valuable to all who have an interest in the field of neuroscience, from the psychiatrist and the radiologist/nuclear medicine specialist to the interested general practitioner and cognitive psychologist. It is the first volume of a trilogy on PET and SPECT imaging in the neurosciences; other volumes will focus on PET and SPECT in neurology and PET and SPECT of neurobiological systems.

  5. PET and SPECT in psychiatry

    Energy Technology Data Exchange (ETDEWEB)

    Dierckx, Rudi A.J.O. [University Medical Center Groningen (Netherlands). Dept. of Nuclear Medicine and Molecular Imaging; Ghent Univ. (Belgium); Otte, Andreas [Univ. of Applied Sciences Offenburg (Germany). Faculty of Electrical Engineering and Information Technology; Vries, Erik F.J. de; Waarde, Aren van (eds.) [University Medical Center Groningen (Netherlands). Dept. of Nuclear Medicine and Molecular Imaging

    2014-09-01

    Covers classical psychiatric disorders as well as other subjects such as suicide, sleep, eating disorders, and autism. Emphasis on a multidisciplinary approach. Written by internationally acclaimed experts. PET and SPECT in Psychiatry showcases the combined expertise of renowned authors whose dedication to the investigation of psychiatric disease through nuclear medicine technology has achieved international recognition. The classical psychiatric disorders as well as other subjects - such as suicide, sleep, eating disorders, and autism - are discussed and the latest results in functional neuroimaging are detailed. Most chapters are written jointly by a clinical psychiatrist and a nuclear medicine expert to ensure a multidisciplinary approach. This state of the art compendium will be valuable to all who have an interest in the field of neuroscience, from the psychiatrist and the radiologist/nuclear medicine specialist to the interested general practitioner and cognitive psychologist. It is the first volume of a trilogy on PET and SPECT imaging in the neurosciences; other volumes will focus on PET and SPECT in neurology and PET and SPECT of neurobiological systems.

  6. Studies on the shelf-life of L-35S methionine

    International Nuclear Information System (INIS)

    A systematic study conducted on the shelf -life of L-35S- methionine, an important radiotracer used in protein synthesis experiments is reported. Aliquots of 35S-methionine from bulk sample prepared by us were kept under chosen conditions of storage and were analysed by paper chromatography coupled with autoradiography. The radiochemical purity (RCP) of 35S-methionine at various time interval spanning over a period of about one half-life of 35S radioisotope (87.4 days) was determined. It was observed that the RCP came down only to about 89% from the original value of 96% at the end of the period of study under the chosen conditions. (author)

  7. Effects of Rumen Protected Methionine on Milk Yield and Milk Composition in Earlier Lactating Cow

    Institute of Scientific and Technical Information of China (English)

    SUN Manji; SHAN Anshan

    2008-01-01

    A total of 12 mature healthy Holstein dairy cows of the nearly body weight (580±30) kg, milk yield (22.5±2.8) kg in the early stages of lactation were selected in this experiment. The cows were randomly divided into 2 groups, every group had 6 cows, every group had 6 repeats, and every repeat had I cow. Added 20 g protected methionine in earlier lactating cow food every day. The results showed that protected methionine increased milk yield by 10.83%, testing group milk yield was significantly different than that of control (P<0.05);protected methionine increased milk fat by 5.98%, testing group milk fat was significantly different than that of control (P<0.05);Milk protein increased by 2.15%, but had insignificantly different (P>0.05);dry matter of milk had the tendency of decrease, but had insignificant difference (P>0.05).

  8. Effects of sucrose on rFVIIa aggregation and methionine oxidation

    DEFF Research Database (Denmark)

    Soenderkaer, Susanne; Carpenter, John F; van de Weert, Marco;

    2004-01-01

    The aim of this study was to characterize the effects of sucrose on the stability of recombinant factor VIIa (rFVIIa), with special emphasis on aggregation and methionine oxidation, as well as to investigate the impact of various environmental conditions on the rFVIIa conformation. The stability...... of rFVIIa was studied at pH 5. Aggregation was monitored using size exclusion high-performance liquid chromatography (SE-HPLC), whereas formation of methionine oxidation products was measured by reversed-phase high-performance liquid chromatography (RP-HPLC). Fourier transform infrared (FTIR...... the protein's surface, which shifts the protein molecular population away from expanded aggregation competent species and toward the compact native state, is thought to account for these observations. rFVIIa is sensitive to methionine oxidation; two mono-oxidized and one di-oxidized product were formed upon...

  9. Comparison of autologous 111In-leukocytes, 18F-FDG, 11C-methionine, 11C-PK11195 and 68Ga-citrate for diagnostic nuclear imaging in a juvenile porcine haematogenous Staphylococcus aureus osteomyelitis model

    DEFF Research Database (Denmark)

    Nielsen, Ole L.; Afzelius, Pia; Bender, Dirk;

    characterized as abscesses/cellulitis, arthritis in three joints and five enlarged lymph nodes. None of the tracers accumulated in joints with arthritis. By comparing the 10 infectious lesions, 18F-FDG accumulated in nine, 111In-leukocytes in eight, 11C-methionine in six, 68Ga-citrate in four and 11C-PK11195...... accumulated in only one lesion. Overall, 18F-FDG PET was superior to 111In-leukocyte SPECT in marking infectious and proliferative, i.e. hyperplastic, lesions. However, leukocyte SPECT was performed as early scans, approximately 6 h after injection of the leukocytes, to match the requirements of the 18 h long...

  10. Pet insurance--essential option?

    Science.gov (United States)

    Stowe, J D

    2000-08-01

    As Hawn (2) says, "insurance is about risk and peace of mind." She reports that the American Humane Society supports pet insurance because companion animals are able to be treated for disease or accidents that are life-threatening where, otherwise, they would have been euthanized. For veterinarians, she suggests that pet insurance allows them to practice veterinary medicine "as if it were free." It is inevitable that pet insurance will grow as a recourse for veterinary fees. This may be a savior to some families whose budget is stretched to the limit at a critical moment in the health care of their cherished pet. We in the veterinary profession have an advantage over other professions. We have seen the good, the bad, and the ugly of insurance, as it applies to human health and dental care. If we work hand-in-hand with our own industries, collectively we may be able to develop a system that wins for everyone, with fees that allow practice to thrive and growth strategies that accommodate new treatment and diagnostic modalities, as well as consistent and exemplary customer service. The path ahead is always fraught with bumps and potholes. We can be a passive passenger and become a victim of the times or an active driver to steer the profession to a clearer route. Pet insurance is but one of the solutions for the profession; the others are a careful assessment of our fees--charging what we are worth, not what we think the client will pay; business management; customer service; leadership of our health care team; lifelong learning; and more efficient delivery systems. Let us stop being a victim, stop shooting ourselves in the professional foot, and seize the day! PMID:10945132

  11. Modified bean seed protein phaseolin did not accumulate stably in transgenic tobacco seeds after methionine enhancement mutations

    Science.gov (United States)

    The major seed storage protein phaseolin of common bean (Phaseolus vulgaris L.) is deficient in methionine, an essential amino acid for human and animal health. To improve the nutritional quality of common bean, we designed methionine enhancement of phaseolin based on the three dimensional structure...

  12. Nutritional levels of digestible methionine + cystine to brown-egg laying hens from 50 to 66 weeks of age

    Directory of Open Access Journals (Sweden)

    Clauber Polese

    2012-07-01

    Full Text Available The objective of this study was to determine the requirement of digestible methionine + cystine of brown-eggs laying hens from 50 to 66 weeks age at the end of the first production cycle. The design was completely randomized, with 150 Brown Shaver hens, which were distributed in five treatments with six replications of five birds each. Birds received a basal diet with 2857 kcal/kg metabolizable energy and 15.97% crude protein, supplemented with 0.132; 0.174, 0.215, 0.256 and 0.298% DL-methionine (98%, in order to provide 0.572, 0.613, 0.653, 0.693 and 0.734% digestible methionine + cystine. The levels of digestible methionine + digestible cystine followed, respectively, the relations of 67, 72, 77, 81 and 86% with lysine fixed at 0.851%. Feed intake, methionine + cystine intake, feed conversion per dozen eggs, egg weigth and mass, percentage of egg components, internal egg quality and weight gain were evaluated. Methionine + cystine levels showed a quadratic effect on feed conversion per dozen eggs and egg weight, a linear effect on feed conversion per kilogram of eggs and percentage of albumen. There was also a positive linear effect on yolk percentage. The methionine + cystine requirement was estimated at 0.572%, corresponding to 682 mg of digestible methionine + cystine/bird/day.

  13. PET in cerebrovascular disease; PET bei zerebrovaskulaeren Erkrankungen

    Energy Technology Data Exchange (ETDEWEB)

    Herholz, K. [Neurologische Universitaetsklinik der Univ. Koeln (Germany)]|[Max-Planck-Institut fuer Neurologische Forschung, Koeln (Germany)

    1997-03-01

    Tissue viability is of particular interest in acute cerebral ischemia because it may be preserved if reperfusion can be achieved rapidly, e.g. by acute thrombolysis. Measurements of regional cerebral blood flow (CBF) and oxygen consumption by PET can assess tissue viability, and they have substantially increased our knowledge of th pathophysiology of ischemic stroke and the associated penumbra. Widerspread clinical application in acute stroke, however, is unlikely because of the large logistic and personnel resources required. In chronic cerebrovascular disease, measurement of regional CBF and glucose metabolism, which is usually coupled, provide detailed insights in disturbance of cortical function, e.g. due to deafferentiation, and contribute to differentiation of dementia types. Chronic misery perfusion, i.e. reduced perfusion that does not match the metabolic demand of the tissue, can be demonstrated by PET. It may be found in some patients with high-grade arterial stenoses. Less severe impairment of brain perfusion can be demonstrated by measurement of the cerebrovascular reserve capacity. The most frequent clinical situations can be assessed by less demanding procedures, e.g. by SPECT. In conclusion, PET has its role in cerebrovascular disease primarily within scientific studies, where high resolution and absolute quantitation of physiological variables are essential. (orig.). 65 refs. [Deutsch] Beim akuten ischaemischen Insult ist die Vitalitaet des Gewebes von besonderem Interesse, da sie durch rasche Reperfusion, z.B. durch Thrombolyse, erhalten bleiben kann. Messungen der zerebralen Durchblutung und des Sauerstoffumsatzes mittels PET geben darueber wesentliche Aufschluesse, und sie sind wichtig fuer das Verstaendnis der Pathophysiologie ischaemischer Infarkte und der Penumbra mit kritischer Perfusion beim Menschen. Ihre breitere Anwendung in der klinischen Patientenversorgung kommt allerdings wegen des hohen Aufwandes derzeit kaum in Betracht. Bei

  14. Realization of an apparatus for the synthesis and detection of carbon 11 labelled fatty acids and of a data acquisition system for the study of the myocardial methabolism of radiopharmaceuticals

    International Nuclear Information System (INIS)

    This thesis describes the study and the realization of an apparatus to synthesize fatty acids labelled with carbon 11, a radioactive isotope with an half-life of 20.38 minutes. A system of gamma-ray detection with data processing designed for the study of the myocardiac metabolism of radiopharmaceuticals using isolated rat hearts as experimental models. The synthesis of carbon 11 labelled fatty acids required a preliminary study of the manufacture of this isotope at the synchrocyclotron of the I.P.N. (Lyon). The method chosen is the nuclear reaction (d,xn) with naturally occurring boron trioxide as the target. The apparatus was designed so as extract carbon 11 from the target in the form of 11CO2 which can then be used in the synthesis of carbon 11 labelled hexadecanoique, heptadecanoic and beta-methyl hexadecanoic acids. The time scale of this synthesis must be compatible with the short half-like of the isotope. In order to study these compounds 'in vivo' on the experimental model of isolated rat hearts, a system of detection, which functions either in a simple gamma mode or in a gamma-gamma coincidence mode, was developed. This apparatus can attain a rate of approximately 50 000 counts/sec. per channel, thus it is possible to obtain information about rapid phases of metabolism with a satisfactory statistical precision. Moreover the spectral analysis of the gamma-ray permits the simultaneous detection of different radioisotopes. Hence it was possible to compare the behaviour of carbon 11 labelled fatty acids with homologous molecules marked with iodine 123. The analysis of the experimental results was achieved witha computer based on an I.B.M. compatible PC-XT. The essential parts of this system are a data-acquisition card for the PC, code for the acquisition and the data processing

  15. PET and SPET tracers for mapping the cardiac nervous system

    International Nuclear Information System (INIS)

    The human cardiac nervous system consists of a sympathetic and a parasympathetic branch with (-)-norepinephrine and acetylcholine as the respective endogenous neurotransmitters. Dysfunction of the cardiac nervous system is implicated in various types of cardiac disease, such as heart failure, myocardial infarction and diabetic autonomic neuropathy. In vivo assessment of the distribution and function of cardiac sympathetic and parasympathetic neurones with positron emission tomography (PET) and single-photon emission tomography (SPET) can be achieved by means of a number of carbon-11-, fluorine-18-, bromine-76- and iodine-123-labelled tracer molecules. Available tracers for mapping sympathetic neurones can be divided into radiolabelled catecholamines, such as 6-[18F]fluorodopamine, (-)-6-[18F]fluoronorepinephrine and (-)-[11C]epinephrine, and radiolabelled catecholamine analogues, such as [123I]meta-iodobenzylguanidine, [11C]meta-hydroxyephedrine, [18F]fluorometaraminol, [11C]phenylephrine and meta-[76Br]bromobenzylguanidine. Resistance to metabolism by monoamine oxidase and catechol-O-methyl transferase simplifies the myocardial kinetics of the second group. Both groups of compounds are excellent agents for an overall assessment of sympathetic innervation. Biomathematical modelling of tracer kinetics is complicated by the complexity of the steps governing neuronal uptake, retention and release of these agents as well as by their high neuronal affinity, which leads to partial flow dependence of uptake. Mapping of cardiac parasympathetic neurones is limited by a low density and focal distribution pattern of these neurones in myocardium. Available tracers are derivatives of vesamicol, a molecule that binds to a receptor associated with the vesicular acetylcholine transporter. Compounds like (-)-[18F]fluoroethoxybenzovesamicol display a high degree of non-specific binding in myocardium which restricts their utility for cardiac neuronal imaging. (orig.)

  16. PET and SPET tracers for mapping the cardiac nervous system

    Energy Technology Data Exchange (ETDEWEB)

    Langer, Oliver; Halldin, Christer [Department of Clinical Neuroscience, Psychiatry Section, Karolinska Institute, Karolinska Hospital, 17176 Stockholm (Sweden)

    2002-03-01

    The human cardiac nervous system consists of a sympathetic and a parasympathetic branch with (-)-norepinephrine and acetylcholine as the respective endogenous neurotransmitters. Dysfunction of the cardiac nervous system is implicated in various types of cardiac disease, such as heart failure, myocardial infarction and diabetic autonomic neuropathy. In vivo assessment of the distribution and function of cardiac sympathetic and parasympathetic neurones with positron emission tomography (PET) and single-photon emission tomography (SPET) can be achieved by means of a number of carbon-11-, fluorine-18-, bromine-76- and iodine-123-labelled tracer molecules. Available tracers for mapping sympathetic neurones can be divided into radiolabelled catecholamines, such as 6-[{sup 18}F]fluorodopamine, (-)-6-[{sup 18}F]fluoronorepinephrine and (-)-[{sup 11}C]epinephrine, and radiolabelled catecholamine analogues, such as [{sup 123}I]meta-iodobenzylguanidine, [{sup 11}C]meta-hydroxyephedrine, [{sup 18}F]fluorometaraminol, [{sup 11}C]phenylephrine and meta-[{sup 76}Br]bromobenzylguanidine. Resistance to metabolism by monoamine oxidase and catechol-O-methyl transferase simplifies the myocardial kinetics of the second group. Both groups of compounds are excellent agents for an overall assessment of sympathetic innervation. Biomathematical modelling of tracer kinetics is complicated by the complexity of the steps governing neuronal uptake, retention and release of these agents as well as by their high neuronal affinity, which leads to partial flow dependence of uptake. Mapping of cardiac parasympathetic neurones is limited by a low density and focal distribution pattern of these neurones in myocardium. Available tracers are derivatives of vesamicol, a molecule that binds to a receptor associated with the vesicular acetylcholine transporter. Compounds like (-)-[{sup 18}F]fluoroethoxybenzovesamicol display a high degree of non-specific binding in myocardium which restricts their utility

  17. Purification and Characterization of l-Methionine γ-Lyase from Brevibacterium linens BL2†

    OpenAIRE

    Dias, Benjamin; Weimer, Bart

    1998-01-01

    l-Methionine γ-lyase (EC 4.4.1.11) was purified to homogeneity from Brevibacterium linens BL2, a coryneform bacterium which has been used successfully as an adjunct bacterium to improve the flavor of Cheddar cheese. The enzyme catalyzes the α,γ elimination of methionine to produce methanethiol, α-ketobutyrate, and ammonia. It is a pyridoxal phosphate-dependent enzyme, with a native molecular mass of approximately 170 kDa, consisting of four identical subunits of 43 kDa each. The purified enzy...

  18. Molecular characterization of the mde operon involved in L-methionine catabolism of Pseudomonas putida.

    OpenAIRE

    H. Inoue; Inagaki, K.; Eriguchi, S I; Tamura, T.; Esaki, N; Soda, K; Tanaka, H.

    1997-01-01

    A 15-kb region of Pseudomonas putida chromosomal DNA containing the mde operon and an upstream regulatory gene (mdeR) has been cloned and sequenced. The mde operon contains two structural genes involved in L-methionine degradative metabolism: the already-identified mdeA, which encodes L-methionine gamma-lyase (H. Inoue, K. Inagaki, M. Sugimoto, N. Esaki, K. Soda, and H. Tanaka. J. Biochem. (Tokyo) 117:1120-1125, 1995), and mdeB, which encodes a homologous protein to the homodimeric-type E1 co...

  19. Oxidation of methionine-containing peptides by rad OH radicals: Is sulfoxide the only product? Study by mass spectrometry and IRMPD spectroscopy

    Science.gov (United States)

    Ignasiak, Marta; de Oliveira, Pedro; Levin, Chantal Houée; Scuderi, Debora

    2013-12-01

    Although the first steps of the oxidation of methionine containing peptides by rad OH radicals have been very well documented, not much is known about the final products. They have been characterized and unraveled by mass spectrometry and IR Multiple Photon Dissociation (IRMPD) spectroscopy carried out with model dipeptides and methionine enkephalin, often involving the transformation of residues other than methionine. Several products were found, in addition to methionine sulfoxide, which is omnipresent. Thus IRMPD proved to be very useful in oxidative proteomics.

  20. Differences in plasma metabolomics between sows fed DL-methionine and its hydroxy analogue reveal a strong association of milk composition and neonatal growth with maternal methionine nutrition.

    Science.gov (United States)

    Zhang, Xiaoling; Li, Hao; Liu, Guangmang; Wan, Haifeng; Mercier, Yves; Wu, Caimei; Wu, Xiuqun; Che, Lianqiang; Lin, Yan; Xu, Shengyu; Tian, Gang; Chen, Daiwen; Wu, De; Fang, Zhengfeng

    2015-02-28

    The aim of the present study was to determine whether increased consumption of methionine as DL-methionine (DLM) or its hydroxy analogue DL-2-hydroxy-4-methylthiobutanoic acid (HMTBA) could benefit milk synthesis and neonatal growth. For this purpose, eighteen cross-bred (Landrace × Yorkshire) primiparous sows were fed a control (CON), DLM or HMTBA diet (n 6 per diet) from 0 to 14 d post-partum. At postnatal day 14, piglets in the HMTBA group had higher body weight (P= 0·02) than those in the CON group, tended (P= 0·07) to be higher than those in the DLM group, and had higher (Pmethionine and valine levels; however, consumption of the DLM diet led to lower (Pmethionine levels and sources, which resulted in marked alterations in amino acid, lipid and glycogen metabolism.

  1. Present and future aspects of PET examinations

    International Nuclear Information System (INIS)

    The PET examination gives the body distribution image of a compound labeled with the positron emitter manufactured by cyclotron. Recently, PET with F18-deoxyglucose (FDG) attracts considerable attention because the imaging is particularly useful for cancer detection. Since the technique was authorized by the United States (US) official health insurance in 1998, the number of the examination is increasing, which is also under similar situation in Japan due to the latest partial authorization for some malignant tumors. In Japan, about 30,000 examinations per year are carried out, half of which, in private hospitals. Their purpose is increasingly for cancer detection. For future PET examination, awaited are improvement of PET camera and development of a novel imaging agent. PET/CT imaging is for the former and F18-α-methyltyrosine, for the latter. Miniaturization of cyclotron, FDG delivery system, improved FDG synthetic method, popularization of PET/CT, development of PET camera for health examination, clinical trial of a novel imaging agent, and spread of PET health examination and operation of PET Center, are expected for future progress of PET technique. (N.I.)

  2. PET/MRI and PET/CT in advanced gynaecological tumours: initial experience and comparison

    Energy Technology Data Exchange (ETDEWEB)

    Queiroz, Marcelo A.; Schulthess, Gustav von; Veit-Haibach, Patrick [University Hospital Zurich, Department Medical Radiology, Nuclear Medicine, Zurich (Switzerland); University Hospital Zurich, Department Medical Radiology, Diagnostic and Interventional Radiology, Zurich (Switzerland); University of Zurich, Zurich (Switzerland); Kubik-Huch, Rahel A.; Freiwald-Chilla, Bianka [Kantonsspital Baden AG, Department of Radiology, Baden (Switzerland); Hauser, Nik [Kantonsspital Baden AG, Department of Gynaecology, Baden (Switzerland); Froehlich, Johannes M. [Guerbet AG, Zurich (Switzerland)

    2015-08-15

    To compare the diagnostic accuracy of PET/MRI and PET/CT for staging and re-staging advanced gynaecological cancer patients as well as identify the potential benefits of each method in such a population. Twenty-six patients with suspicious or proven advanced gynaecological cancer (12 ovarian, seven cervical, one vulvar and four endometrial tumours, one uterine metastasis, and one primary peritoneal cancer) underwent whole-body imaging with a sequential trimodality PET/CT/MR system. Images were analysed regarding primary tumour detection and delineation, loco-regional lymph node staging, and abdominal/extra-abdominal distant metastasis detection (last only by PET/CT). Eighteen (69.2 %) patients underwent PET/MRI for primary staging and eight patients (30.8 %) for re-staging their gynaecological malignancies. For primary tumour delineation, PET/MRI accuracy was statistically superior to PET/CT (p < 0.001). Among the different types of cancer, PET/MRI presented better tumour delineation mainly for cervical (6/7) and endometrial (2/3) cancers. PET/MRI for local evaluation as well as PET/CT for extra-abdominal metastases had therapeutic consequences in three and one patients, respectively. PET/CT detected 12 extra-abdominal distant metastases in 26 patients. PET/MRI is superior to PET/CT for primary tumour delineation. No differences were found in detection of regional lymph node involvement and abdominal metastases detection. (orig.)

  3. Basic study of entire whole-body PET scanners based on the OpenPET geometry

    Energy Technology Data Exchange (ETDEWEB)

    Yoshida, Eiji, E-mail: rush@nirs.go.j [National Institute of Radiological Sciences, 4-9-1 Inage-ku, Chiba 263-8555 (Japan); Yamaya, Taiga; Nishikido, Fumihiko; Inadama, Naoko; Murayama, Hideo [National Institute of Radiological Sciences, 4-9-1 Inage-ku, Chiba 263-8555 (Japan)

    2010-09-21

    A conventional PET scanner has a 15-25 cm axial field-of-view (FOV) and images a whole body using about six bed positions. An OpenPET geometry can extend the axial FOV with a limited number of detectors. The entire whole-body PET scanner must be able to process a large amount of data effectively. In this work, we study feasibility of the fully 3D entire whole-body PET scanner using the GATE simulation. The OpenPET has 12 block detector rings with the ring diameter of 840 mm and each block detector ring consists of 48 depth-of-interaction (DOI) detectors. The OpenPET has the axial length of 895.95 mm with five parts of 58.95 mm open gaps. The OpenPET has higher single data loss than a conventional PET scanner at grouping circuits. NECR of the OpenPET decreases by single data loss. But single data loss is mitigated by separating the axially arranged detector into two parts. Also, multiple coincidences are found to be important for the entire whole-body PET scanner. The entire whole-body PET scanner with the OpenPET geometry promises to provide a large axial FOV with the open space and to have sufficient performance values. But single data loss at the grouping circuits and multiple coincidences are limited to the peak noise equivalent count rate (NECR) for the entire whole-body PET scanner.

  4. Progression-free and overall survival in metastatic castration-resistant prostate cancer treated with abiraterone acetate can be predicted with serial C11-acetate PET/CT.

    Science.gov (United States)

    Farnebo, Jacob; Wadelius, Agnes; Sandström, Per; Nilsson, Sten; Jacobsson, Hans; Blomqvist, Lennart; Ullén, Anders

    2016-08-01

    In this retrospective study, we evaluated the benefit of repeated carbon 11 (C11)-acetate positron emission tomography/computed tomography (PET/CT) to assess response in patients with metastatic castration-resistant prostate cancer (mCRPC) treated with abiraterone acetate (AA).A total of 30 patients with mCRPC were monitored with C11-acetate PET/CT and PSA levels during their treatment with AA. Retrospective evaluation of their response was made after 102 days (median; range 70-155) of treatment. Statistical analyses were employed to detect predictors of progression-free survival (PFS) and overall survival (OS), and potential correlation between serum levels of PSA, standardized uptake values (SUVpeak), and bone lesion index measured from PET were investigated.At follow-up 10 patients exhibited partial response (PR), 10 progressive disease (PD), and 10 stable disease (SD), as assessed by PET/CT. In survival analysis, both PR and PD were significantly associated with PFS and OS. CT response was also associated with OS, but only 19/30 patients demonstrated a lesion meeting target lesion criteria according to RECIST 1.1. No PET/CT baseline characteristic was significantly associated with PFS or OS. A PSA response (reduction in the level by >50%) could also predict PFS and OS. In the subgroup lacking a PSA response, those with PD had significantly shorter OS than those with PR or SD.PFS and OS in patients with mCRPC treated with AA can be predicted from repeated C11-acetate PET/CT. This may be of particular clinical value in patients who do not exhibit a PSA response to treatment. PMID:27495034

  5. Chemoprotection by D-methionine against cisplatin-induced side-effects: insight from in vitro studies using human plasma.

    Science.gov (United States)

    Sooriyaarachchi, Melani; White, Wade M; Narendran, Aru; Gailer, Jürgen

    2014-03-01

    Animal studies have shown that the nephrotoxicity and ototoxicity of the anti-cancer drug cisplatin (CP) can be ameliorated by the co-administration with D-methionine. The molecular mechanisms of this activity, however, are not well understood. Since CP is intravenously administered, the underlying chemistry may involve the interaction of CP-derived Pt-species with D-methionine in the bloodstream. Our previous studies have shown that the chemoprotective agents N-acetyl-l-cysteine and sodium thiosulfate modulate the metabolism of CP in human plasma in vitro, albeit in a different manner. Using a metallomics approach, we show that the incubation of human plasma with D-methionine and CP (molar ratio of 20 : 1) leads to the formation of a Pt-D-methionine complex independent of the order of addition. These results were corroborated by analogous experiments that were carried out using PBS-buffer instead of plasma. In addition, CP and D-methionine were added simultaneously to PBS-buffer and samples were analyzed at certain time intervals by the same metallomics method and LC-ESI-MS over a ∼21 h time period. Whereas the intermediate [Pt(NH3)Cl(D-methionine)](+) species was detected between 1-4 h, only the terminal [Pt(D-methionine)2](+) complex was present 21 h later. Combined, these studies demonstrate that in plasma and at the 20 : 1 D-methionine : CP molar ratio, an early CP hydrolysis product reacts with D-methionine to form a 1 : 1 complex that is followed by the formation of a 2 : 1 compound at a later time point. The formation of these Pt-D-methionine species may therefore play an important role in the processes by which D-methionine protects mammalian organisms against CP-induced toxicities.

  6. Bioavailability of D-methionine relative to L-methionine for nursery pigs using the slope-ratio assay

    Science.gov (United States)

    Kong, Changsu; Ahn, Jong Young

    2016-01-01

    This experiment was conducted to determine the bioavailability of D-methionine (Met) relative to L-Met for nursery pigs using the slope-ratio assay. A total of 50 crossbred barrows with an initial BW of 13.5 kg (SD = 1.0) were used in an N balance study. A Met-deficient basal diet (BD) was formulated to contain an adequate amount of all amino acids (AA) for 10–20 kg pigs except for Met. The two reference diets were prepared by supplementing the BD with 0.4 or 0.8 g L-Met/kg at the expense of corn starch, and an equivalent concentration of D-Met was added to the BD for the two test diets. The pigs were adapted to the experimental diets for 5 d and then total but separated collection of feces and urine was conducted for 4 d according to the marker-to-marker procedure. Nitrogen intakes were similar across the treatments. Fecal N output was not affected by Met supplementation regardless of source and consequently apparent N digestibility did not change. Conversely, there was a negative linear response (P < 0.01) to Met supplementation with both Met isomers in urinary N output, which resulted in increased retained N (g/4 d) and N retention (% of intake). No quadratic response was observed in any of the N balance criteria. The estimated bioavailability of D-Met relative to L-Met from urinary N output (g/4 d) and N retention (% of intake) as dependent variables using supplemental Met intake (g/4 d) as an independent variable were 87.6% and 89.6%, respectively; however, approximately 95% of the fiducial limits for the relative bioavailability estimates included 100%. In conclusion, with an absence of statistical significance, the present study indicated that the mean relative bioequivalence of D- to L-Met was 87.6% based on urinary N output or 89.6% based on N retention. PMID:27651987

  7. Bioavailability of D-methionine relative to L-methionine for nursery pigs using the slope-ratio assay.

    Science.gov (United States)

    Kong, Changsu; Ahn, Jong Young; Kim, Beob G

    2016-01-01

    This experiment was conducted to determine the bioavailability of D-methionine (Met) relative to L-Met for nursery pigs using the slope-ratio assay. A total of 50 crossbred barrows with an initial BW of 13.5 kg (SD = 1.0) were used in an N balance study. A Met-deficient basal diet (BD) was formulated to contain an adequate amount of all amino acids (AA) for 10-20 kg pigs except for Met. The two reference diets were prepared by supplementing the BD with 0.4 or 0.8 g L-Met/kg at the expense of corn starch, and an equivalent concentration of D-Met was added to the BD for the two test diets. The pigs were adapted to the experimental diets for 5 d and then total but separated collection of feces and urine was conducted for 4 d according to the marker-to-marker procedure. Nitrogen intakes were similar across the treatments. Fecal N output was not affected by Met supplementation regardless of source and consequently apparent N digestibility did not change. Conversely, there was a negative linear response (P < 0.01) to Met supplementation with both Met isomers in urinary N output, which resulted in increased retained N (g/4 d) and N retention (% of intake). No quadratic response was observed in any of the N balance criteria. The estimated bioavailability of D-Met relative to L-Met from urinary N output (g/4 d) and N retention (% of intake) as dependent variables using supplemental Met intake (g/4 d) as an independent variable were 87.6% and 89.6%, respectively; however, approximately 95% of the fiducial limits for the relative bioavailability estimates included 100%. In conclusion, with an absence of statistical significance, the present study indicated that the mean relative bioequivalence of D- to L-Met was 87.6% based on urinary N output or 89.6% based on N retention. PMID:27651987

  8. Differences in plasma metabolomics between sows fed DL-methionine and its hydroxy analogue reveal a strong association of milk composition and neonatal growth with maternal methionine nutrition.

    Science.gov (United States)

    Zhang, Xiaoling; Li, Hao; Liu, Guangmang; Wan, Haifeng; Mercier, Yves; Wu, Caimei; Wu, Xiuqun; Che, Lianqiang; Lin, Yan; Xu, Shengyu; Tian, Gang; Chen, Daiwen; Wu, De; Fang, Zhengfeng

    2015-02-28

    The aim of the present study was to determine whether increased consumption of methionine as DL-methionine (DLM) or its hydroxy analogue DL-2-hydroxy-4-methylthiobutanoic acid (HMTBA) could benefit milk synthesis and neonatal growth. For this purpose, eighteen cross-bred (Landrace × Yorkshire) primiparous sows were fed a control (CON), DLM or HMTBA diet (n 6 per diet) from 0 to 14 d post-partum. At postnatal day 14, piglets in the HMTBA group had higher body weight (P= 0·02) than those in the CON group, tended (P= 0·07) to be higher than those in the DLM group, and had higher (Phistidine and ornithine concentrations decreased in the DLM diet-fed sows (Pacetate and higher (P< 0·05) plasma levels of citrate, lactate, formate, glycerol, myo-inositol and N-acetyl glycoprotein in sows. Collectively, neonatal growth and milk synthesis were regulated by dietary methionine levels and sources, which resulted in marked alterations in amino acid, lipid and glycogen metabolism. PMID:25639894

  9. Comparative PET/CT study with 11C-MET and 18F-FDG for diagnosing Glioma

    International Nuclear Information System (INIS)

    In this paper, we investigate the diagnostic value of 11C-methionine (MET) positron emission tomography/computed tomography (PET/CT) for brain gliomas, and compare the results to 18F-fluorodeoxyglucose. Forty-four patients with suspected gliomas were examined with 11C-MET and 18F-FDG PET/CT. 18F-FDG and 11C-MET PET/CT images were compared and evaluated by visual and semiquantitative analysis. The accuracy of 11C-MET and 18F-FDG PET/CT for detecting gliomas were 88.6% and 65.9%, respectively. Semiquantitative analysis showed that the 26 gliomas had higher mean ± SD T/NGmax ratio on 11C-MET PET/CT than on 18F-FDG PET/CT(1.95±0.52 vs. 0.90±0.27, t=9.101, P11C-MET had a higher sensitivity than 18F-FDG (83.3% vs.33.3%, χ2 =4.16, P18F-FDG in the sensitivity for high-grade gliomas(100% vs. 64.3%, χ2=3.20, P>0.05). The difference was no significant, too, between high-and low-grade gliomas, compared by 11C-MET T/NGmax ratio (2.07±0.51 vs. 1.81±0.52, t=1.302, P=0.205). 18F-FDG T/NGmax ratio in high-grade gliomas was significantly higher than that in low-grade gliomas (1.03±0.30 vs. 0.75±0.11, t=3.198, P=0.004). It is concluded that 11C-MET PET/CT is more accurate than 18F-FDG PET/CT for detecting and delineating gliomas, especially for low-grade gliomas, and it can play a complement role to 18F-FDG in tumor grading. (authors)

  10. The potential of carbon-11 and fluorine-18 chemistry: illustration through the development of positron emission tomography radioligands targeting the translocator protein 18 kDa

    International Nuclear Information System (INIS)

    The TSPO (translocator protein), also known as the peripheral benzodiazepine receptor, is up-regulated in the brain of subjects suffering from neuro-degenerative disorders such as Alzheimer's, Parkinson's and Huntington's disease. Moreover, this overexpression has been proved to be linked to micro-glia activation making thus the TSPO a marker of choice of neuro-inflammatory processes and therefore a potential target for the development of radioligands for positron emission tomography imaging. The discovery of selective TSPO ligands and their labelling with the short-lived positron-emitter isotopes carbon-11 and fluorine-18 emerged in the mid-1980's with the preparation of the 3-iso-quinolinecarboxamide [11C]PK11195. To date, an impressive number of promising compounds - [11C]PK11195-challengers - have been developed; some radioligands - for example, [11C]PBR28, [11C]DPA-713, [18F]FEDAA1106 and [18F]DPA-714 - are currently used in clinical trials. As illustrated in this review, the methodologies applied for the preparation of these compounds remain mainly [11C]methylations using [11C]MeI or [11C]MeOTf and SN2- type nucleophilic aliphatic [18F]fluorinations - two processes illustrating the state-of-the-art arsenal of reactions that involves these two short-lived radioisotopes - but alternative processes, such as [11C]carbonylations using [11C]CO and [11C]COCl2 as well as SNAr-type nucleophilic [18F]fluorinations, have also been reported and as such, reviewed herein. (authors)

  11. Assessment of the effects of dobutamine on myocardial blood flow and oxidative metabolism in normal human subjects using nitrogen-13 ammonia and carbon-11 acetate.

    Science.gov (United States)

    Krivokapich, J; Huang, S C; Schelbert, H R

    1993-06-01

    The dual purposes of this study with positron emission tomography were to measure the effects of dobutamine on myocardial blood flow and oxidative metabolism, and to compare carbon-11 (C-11) acetate versus nitrogen-13 (N-13) ammonia in quantitating flow in normal subjects. Flow was quantitated with N-13 ammonia at rest and at peak dobutamine infusion (40 micrograms/kg/min) in 21 subjects. In 11 subjects, oxidative metabolism was also estimated at rest and peak dobutamine infusion using the clearance rate of C-11 acetate, k mono (min-1). A 2-compartment kinetic model was applied to the early phase of the C-11 acetate data to estimate flow. The rest and peak dobutamine rate-pressure products were 7,318 +/- 1,102 and 19,937 +/- 3,964 beats/min/mm Hg, respectively, and correlated well (r = 0.77) with rest and peak dobutamine flows of 0.77 +/- 0.14 and 2.25 ml/min/g determined using N-13 ammonia as a flow tracer. Rest and dobutamine flows estimated with C-11 acetate were highly correlated with those determined with N-13 ammonia (r = 0.92). k mono increased from 0.05 +/- 0.01 to 0.18 +/- 0.02 min-1, and correlated highly with the increase in flows (r = 0.91) and rate-pressure products (r = 0.94). Thus, the increase in cardiac demand associated with dobutamine is highly correlated with an increase in supply and oxidative metabolism. C-11 acetate is a unique tracer that can be used to image both flow and metabolism simultaneously. PMID:8498380

  12. In vitro selenium accessibility in pet foods is affected by diet composition and type.

    Science.gov (United States)

    van Zelst, Mariëlle; Hesta, Myriam; Alexander, Lucille G; Gray, Kerry; Bosch, Guido; Hendriks, Wouter H; Du Laing, Gijs; De Meulenaer, Bruno; Goethals, Klara; Janssens, Geert P J

    2015-06-28

    Se bioavailability in commercial pet foods has been shown to be highly variable. The aim of the present study was to identify dietary factors associated with in vitro accessibility of Se (Se Aiv) in pet foods. Se Aiv is defined as the percentage of Se from the diet that is potentially available for absorption after in vitro digestion. Sixty-two diets (dog, n 52; cat, n 10) were in vitro enzymatically digested: fifty-four of them were commercially available (kibble, n 20; pellet, n 8; canned, n 17; raw meat, n 6; steamed meat, n 3) and eight were unprocessed (kibble, n 4; canned, n 4) from the same batch as the corresponding processed diets. The present investigation examined if Se Aiv was affected by diet type, dietary protein, methionine, cysteine, lysine and Se content, DM, organic matter and crude protein (CP) digestibility. Se Aiv differed significantly among diet types (Pextrusion (n 4) revealed no effect on Se Aiv (P =0·297). These differences in Se Aiv between diet types warrant quantification of diet type effects on in vivo Se bioavailability. PMID:25994047

  13. Clinical Application of {sup 18}F-FDG PET and PET-CT in Adrenal Tumor

    Energy Technology Data Exchange (ETDEWEB)

    Hwang, Kyung Hoon; Choi, Duck Joo; Lee, Min Kyung; Choe, Won Sick [Gachon University Gil Hospital, Incheon (Korea, Republic of)

    2008-12-15

    Adrenal tumors are increasingly detected by widespread use of anatomical imaging such as CT, MRI, etc. For these adrenal tumors, differentiation between malignancy and benignancy is very important. In diagnostic assessment of adrenal tumor, {sup 18}F-FDG PET and PET-CT have been reported to have high diagnostic performance, especially, very excellent performance in evaluation of adrenal metastasis in the oncologic patient. In cases of adrenal incidentalomas, {sup 18}F-FDG PET or PET-CT is helpful if CT or chemical-shift MRI is inconclusive. {sup 18}F-FDG PET and PET-CT may be applied to the patients with MIBG-negative pheochromocytomas. In summary, {sup 18}F-FDG PET and PET-CT are expected to be effective diagnostic tools in the management of adrenal tumor.

  14. FDG PET and PET/CT: EANM procedure guidelines for tumour PET imaging: version 1.0

    DEFF Research Database (Denmark)

    Boellaard, Ronald; O'Doherty, Mike J; Weber, Wolfgang A;

    2010-01-01

    The aim of this guideline is to provide a minimum standard for the acquisition and interpretation of PET and PET/CT scans with [18F]-fluorodeoxyglucose (FDG). This guideline will therefore address general information about[18F]-fluorodeoxyglucose (FDG) positron emission tomography......-computed tomography (PET/CT) and is provided to help the physician and physicist to assist to carrying out,interpret, and document quantitative FDG PET/CT examinations,but will concentrate on the optimisation of diagnostic quality and quantitative information....

  15. Plasma input function determination for PET using a commercial laboratory robot

    International Nuclear Information System (INIS)

    A commercial laboratory robot system (Zymate PyTechnology II Laboratory Automation System) was interfaced to standard and custom laboratory equipment and programmed to perform rapid radiochemical assays necessary for plasma input function determination in quantitative PET studies in humans and baboons. A Zymark XP robot arm was used to carry out two assays: (1) the determination of total plasma radioactivity concentrations in a series of small-volume whole blood samples and (2) the determination of unchanged (parent) radiotracer in plasma using only solid phase extraction methods. Steady state robotic throughput for determination of total plasma radioactivity in whole blood samples (0.350 mL) is 14.3 samples/h, which includes automated centrifugation, pipetting, weighing and radioactivity counting. Robotic throughput for the assay of parent radiotracer in plasma is 4-6 samples/h depending on the radiotracer. Percents of total radioactivities present as parent radiotracers at 60 min. postinjection of 25 ± 5.0 (N 25), 26 ± 6.8 (N = 68), 13 ± 4.4 (N = 30), 32 ± 7.2 (N = 18), 16 ± 4.9 (N = 20), were obtained for carbon-11 labeled benztropine, raclopride, methylphenidate, SR 46349B (trans, 4-[(3Z)3-(2-dimethylamino-ethyl) oxyimino-3 (2-fluorophenyl)propen-1-yl]phenol), and cocaine respectively in baboon plasma and 84 ± 6.4 (N = 9), 18 ± 11 (N = 10), 74 ± 5.7 (N = 118) and 16 ± 3.7 (N = 18) for carbon-11 labeled benztropine, deprenyl, raclopride, and methylphenidate respectively in human plasma. The automated system has been used for more than 4 years for all plasma analyses for 7 different C-11 labeled compounds used routinely in our laboratory. The robotic radiotracer assay runs unattended and includes automated cleanup procedures that eliminates all human contact with plasma-contaminated containers

  16. Plasma input function determination for PET using a commercial laboratory robot

    Energy Technology Data Exchange (ETDEWEB)

    Alexoff, David L.; Shea, Colleen; Fowler, Joanna S.; King, Payton; Gatley, S. John; Schlyer, David J.; Wolf, Alfred P

    1995-10-01

    A commercial laboratory robot system (Zymate PyTechnology II Laboratory Automation System) was interfaced to standard and custom laboratory equipment and programmed to perform rapid radiochemical assays necessary for plasma input function determination in quantitative PET studies in humans and baboons. A Zymark XP robot arm was used to carry out two assays: (1) the determination of total plasma radioactivity concentrations in a series of small-volume whole blood samples and (2) the determination of unchanged (parent) radiotracer in plasma using only solid phase extraction methods. Steady state robotic throughput for determination of total plasma radioactivity in whole blood samples (0.350 mL) is 14.3 samples/h, which includes automated centrifugation, pipetting, weighing and radioactivity counting. Robotic throughput for the assay of parent radiotracer in plasma is 4-6 samples/h depending on the radiotracer. Percents of total radioactivities present as parent radiotracers at 60 min. postinjection of 25 {+-} 5.0 (N 25), 26 {+-} 6.8 (N = 68), 13 {+-} 4.4 (N = 30), 32 {+-} 7.2 (N = 18), 16 {+-} 4.9 (N = 20), were obtained for carbon-11 labeled benztropine, raclopride, methylphenidate, SR 46349B (trans, 4-[(3Z)3-(2-dimethylamino-ethyl) oxyimino-3 (2-fluorophenyl)propen-1-yl]phenol), and cocaine respectively in baboon plasma and 84 {+-} 6.4 (N = 9), 18 {+-} 11 (N = 10), 74 {+-} 5.7 (N = 118) and 16 {+-} 3.7 (N = 18) for carbon-11 labeled benztropine, deprenyl, raclopride, and methylphenidate respectively in human plasma. The automated system has been used for more than 4 years for all plasma analyses for 7 different C-11 labeled compounds used routinely in our laboratory. The robotic radiotracer assay runs unattended and includes automated cleanup procedures that eliminates all human contact with plasma-contaminated containers.

  17. Isotope specific resolution recovery image reconstruction in high resolution PET imaging

    Energy Technology Data Exchange (ETDEWEB)

    Kotasidis, Fotis A. [Division of Nuclear Medicine and Molecular Imaging, Geneva University Hospital, CH-1211 Geneva, Switzerland and Wolfson Molecular Imaging Centre, MAHSC, University of Manchester, M20 3LJ, Manchester (United Kingdom); Angelis, Georgios I. [Faculty of Health Sciences, Brain and Mind Research Institute, University of Sydney, NSW 2006, Sydney (Australia); Anton-Rodriguez, Jose; Matthews, Julian C. [Wolfson Molecular Imaging Centre, MAHSC, University of Manchester, Manchester M20 3LJ (United Kingdom); Reader, Andrew J. [Montreal Neurological Institute, McGill University, Montreal QC H3A 2B4, Canada and Department of Biomedical Engineering, Division of Imaging Sciences and Biomedical Engineering, King' s College London, St. Thomas’ Hospital, London SE1 7EH (United Kingdom); Zaidi, Habib [Division of Nuclear Medicine and Molecular Imaging, Geneva University Hospital, CH-1211 Geneva (Switzerland); Geneva Neuroscience Centre, Geneva University, CH-1205 Geneva (Switzerland); Department of Nuclear Medicine and Molecular Imaging, University of Groningen, University Medical Center Groningen, PO Box 30 001, Groningen 9700 RB (Netherlands)

    2014-05-15

    Purpose: Measuring and incorporating a scanner-specific point spread function (PSF) within image reconstruction has been shown to improve spatial resolution in PET. However, due to the short half-life of clinically used isotopes, other long-lived isotopes not used in clinical practice are used to perform the PSF measurements. As such, non-optimal PSF models that do not correspond to those needed for the data to be reconstructed are used within resolution modeling (RM) image reconstruction, usually underestimating the true PSF owing to the difference in positron range. In high resolution brain and preclinical imaging, this effect is of particular importance since the PSFs become more positron range limited and isotope-specific PSFs can help maximize the performance benefit from using resolution recovery image reconstruction algorithms. Methods: In this work, the authors used a printing technique to simultaneously measure multiple point sources on the High Resolution Research Tomograph (HRRT), and the authors demonstrated the feasibility of deriving isotope-dependent system matrices from fluorine-18 and carbon-11 point sources. Furthermore, the authors evaluated the impact of incorporating them within RM image reconstruction, using carbon-11 phantom and clinical datasets on the HRRT. Results: The results obtained using these two isotopes illustrate that even small differences in positron range can result in different PSF maps, leading to further improvements in contrast recovery when used in image reconstruction. The difference is more pronounced in the centre of the field-of-view where the full width at half maximum (FWHM) from the positron range has a larger contribution to the overall FWHM compared to the edge where the parallax error dominates the overall FWHM. Conclusions: Based on the proposed methodology, measured isotope-specific and spatially variant PSFs can be reliably derived and used for improved spatial resolution and variance performance in resolution

  18. PET/MRI in cancer patients

    DEFF Research Database (Denmark)

    Kjær, Andreas; Loft, Annika; Law, Ian;

    2013-01-01

    Combined PET/MRI systems are now commercially available and are expected to change the medical imaging field by providing combined anato-metabolic image information. We believe this will be of particular relevance in imaging of cancer patients. At the Department of Clinical Physiology, Nuclear...... described include brain tumors, pediatric oncology as well as lung, abdominal and pelvic cancer. In general the cases show that PET/MRI performs well in all these types of cancer when compared to PET/CT. However, future large-scale clinical studies are needed to establish when to use PET/MRI. We envision...... that PET/MRI in oncology will prove to become a valuable addition to PET/CT in diagnosing, tailoring and monitoring cancer therapy in selected patient populations....

  19. Critical Care of Pet Birds.

    Science.gov (United States)

    Jenkins, Jeffrey Rowe

    2016-05-01

    Successful care of the critical pet bird patient is dependent on preparation and planning and begins with the veterinarian and hospital staff. An understanding of avian physiology and pathophysiology is key. Physical preparation of the hospital or clinic includes proper equipment and understanding of the procedures necessary to provide therapeutic and supportive care to the avian patient. An overview of patient intake and assessment, intensive care environment, and fluid therapy is included. PMID:27131161

  20. Pet Store Loyalty in Malaysia

    OpenAIRE

    Leong, Yuen Yee

    2010-01-01

    Loyalty is open studied topic within the retailing and marketing discipline. A strong and profitable base of loyal customers is an asset to any organization, and is one of the epitomes of success for a company. The flourishing of large, specialty niche retailers like Starbucks, Victoria Secret and Barnes & Noble are stellar success stories that thrive on their troop of staunch followers. Pet retailing is a niche market which has its own interesting market characteristics. The emergence of ...

  1. Joint PET-MR respiratory motion models for clinical PET motion correction

    Science.gov (United States)

    Manber, Richard; Thielemans, Kris; Hutton, Brian F.; Wan, Simon; McClelland, Jamie; Barnes, Anna; Arridge, Simon; Ourselin, Sébastien; Atkinson, David

    2016-09-01

    Patient motion due to respiration can lead to artefacts and blurring in positron emission tomography (PET) images, in addition to quantification errors. The integration of PET with magnetic resonance (MR) imaging in PET-MR scanners provides complementary clinical information, and allows the use of high spatial resolution and high contrast MR images to monitor and correct motion-corrupted PET data. In this paper we build on previous work to form a methodology for respiratory motion correction of PET data, and show it can improve PET image quality whilst having minimal impact on clinical PET-MR protocols. We introduce a joint PET-MR motion model, using only 1 min per PET bed position of simultaneously acquired PET and MR data to provide a respiratory motion correspondence model that captures inter-cycle and intra-cycle breathing variations. In the model setup, 2D multi-slice MR provides the dynamic imaging component, and PET data, via low spatial resolution framing and principal component analysis, provides the model surrogate. We evaluate different motion models (1D and 2D linear, and 1D and 2D polynomial) by computing model-fit and model-prediction errors on dynamic MR images on a data set of 45 patients. Finally we apply the motion model methodology to 5 clinical PET-MR oncology patient datasets. Qualitative PET reconstruction improvements and artefact reduction are assessed with visual analysis, and quantitative improvements are calculated using standardised uptake value (SUVpeak and SUVmax) changes in avid lesions. We demonstrate the capability of a joint PET-MR motion model to predict respiratory motion by showing significantly improved image quality of PET data acquired before the motion model data. The method can be used to incorporate motion into the reconstruction of any length of PET acquisition, with only 1 min of extra scan time, and with no external hardware required.

  2. Validation of peneloPET simulations of the Biograph PET/CT scanner with TOF capabilities

    OpenAIRE

    Abushab, K. M.; Herraiz, J. L.; Vicente, E.; España, Samuel; Vaquero, Juan José; Udías, José Manuel

    2010-01-01

    Monte Carlo simulations are currently widely used in positron emission tomography (PET) imaging for optimizing detector design and acquisition protocols, and for developing and assessing corrections and reconstruction methods. PeneloPET is a Monte Carlo code for PET simulations with basic components of detector geometry, acquisition electronics and material and source definitions. The purpose of the present study was to validate the simulations of the Siemens Biograph PET/CT scanner with TOF ...

  3. Joint PET-MR respiratory motion models for clinical PET motion correction.

    Science.gov (United States)

    Manber, Richard; Thielemans, Kris; Hutton, Brian F; Wan, Simon; McClelland, Jamie; Barnes, Anna; Arridge, Simon; Ourselin, Sébastien; Atkinson, David

    2016-09-01

    Patient motion due to respiration can lead to artefacts and blurring in positron emission tomography (PET) images, in addition to quantification errors. The integration of PET with magnetic resonance (MR) imaging in PET-MR scanners provides complementary clinical information, and allows the use of high spatial resolution and high contrast MR images to monitor and correct motion-corrupted PET data. In this paper we build on previous work to form a methodology for respiratory motion correction of PET data, and show it can improve PET image quality whilst having minimal impact on clinical PET-MR protocols. We introduce a joint PET-MR motion model, using only 1 min per PET bed position of simultaneously acquired PET and MR data to provide a respiratory motion correspondence model that captures inter-cycle and intra-cycle breathing variations. In the model setup, 2D multi-slice MR provides the dynamic imaging component, and PET data, via low spatial resolution framing and principal component analysis, provides the model surrogate. We evaluate different motion models (1D and 2D linear, and 1D and 2D polynomial) by computing model-fit and model-prediction errors on dynamic MR images on a data set of 45 patients. Finally we apply the motion model methodology to 5 clinical PET-MR oncology patient datasets. Qualitative PET reconstruction improvements and artefact reduction are assessed with visual analysis, and quantitative improvements are calculated using standardised uptake value (SUV(peak) and SUV(max)) changes in avid lesions. We demonstrate the capability of a joint PET-MR motion model to predict respiratory motion by showing significantly improved image quality of PET data acquired before the motion model data. The method can be used to incorporate motion into the reconstruction of any length of PET acquisition, with only 1 min of extra scan time, and with no external hardware required. PMID:27524409

  4. Induction of Alzheimer's-like changes in brain of mice expressing mutant APP fed excess methionine.

    NARCIS (Netherlands)

    A. McCampbell; K. Wessner; M.W. Marlatt; C. Wolffe; D. Toolan; A. Podtelezhnikov; S. Yeh; R. Zhang; P. Szcerba; K.Q. Tanis; J. Majercak; W.J. Ray; M. Savage

    2011-01-01

    Elevated plasma homocysteine, a risk factor for Alzheimer's disease, could result from increased production from methionine or by inefficient clearance by folate- and B-vitamin-dependent pathways. Understanding the relative contributions of these processes to pathogenesis is important for therapeuti

  5. Urine acidification and mineral metabolism in growing pigs feddiets supplemented with dietary methionine and benzoic acid

    DEFF Research Database (Denmark)

    Nørgaard, Jan Værum; Fernández, José Adalberto; Eriksen, Jørgen;

    2010-01-01

    Benzoic acid (BA) reduces pH of urine and thereby reduces the emission of ammonia and possibly also odorous sulphur-compounds from slurry. The effect of BA on mineral metabolism in growing pigs is not clear. The objective was therefore to study the effect of BA and methionine (Met) as a sulphur (S...

  6. Toward an era of utilizing methionine overproducing hosts for recombinant protein production in Escherichia coli.

    Science.gov (United States)

    Veeravalli, Karthik; Laird, Michael W

    2015-01-01

    Amino acid sequence variants, especially variants containing non-canonical amino acids such as norleucine and norvaline, are a concern during therapeutic protein production in microbial systems. Substitution of methionine residues with norleucine in recombinant proteins produced in Escherichia coli is well known. Continuous feeding of amino acids such as methionine is commonly used in E. coli fermentation processes to control incorporation of norleucine in the recombinant protein. There are several disadvantages associated with continuous feeding during a fermentation process. For example, a continuous feed increases the operational complexity and cost of a manufacturing process and results in dilution of culture medium which could result in lower cell densities and product yields. To overcome the limitations of existing approaches to prevent norleucine incorporation during E. coli fermentations, a new approach using an engineered host was developed that overproduces methionine in the cell to prevent norleucine incorporation without negatively impacting fermentation process performance and product yields. In this commentary, the results on using methionine overproducing hosts for recombinant protein production in E. coli and some "watch outs" when using these hosts for recombinant protein production are discussed.

  7. S-adenosyl-L-methionine for alcoholic liver diseases. Protocol for a Cochrane Review

    DEFF Research Database (Denmark)

    Rambaldi, A; Gluud, C

    2000-01-01

    Alcohol is a major cause of liver disease in the Western world today. S-adenosyl-L-methionine (SAMe) acts as a methyl donor for all known biological methylation reactions and participates in the synthesis of glutathione, the main cellular anti-oxidant. Randomised clinical trials have addressed...

  8. CLONING, EXPRESSION, AND MUTATIONAL ANALYSIS OF RAT S-ADENOSYL-1-METHIONINE: ARSENIC (III) METHYLTRANSFERASE

    Science.gov (United States)

    CLONING, EXPRESSION, AND MUTATIONAL ANALYSIS OF RAT S-ADENOSYL-L-METHIONINE: ARSENIC(III) METHYLTRANSFERASEStephen B. Waters, Ph.D., Miroslav Styblo, Ph.D., Melinda A. Beck, Ph.D., University of North Carolina at Chapel Hill; David J. Thomas, Ph.D., U.S. Environmental...

  9. CLONING, EXPRESSION, AND CHARACTERIZATION OF RAT S-ADENOSYL-L-METHIONINE: ARSENIC (III) METHYLTRANSFERASE (CYT19)

    Science.gov (United States)

    CLONING, EXPRESSION, AND CHARACTERIZATION OF RAT S-ADENOSYL-L-METHIONINE: ARSENIC(III) METHYLTRANSFERASE (cyt19)Stephen B. Waters1 , Felicia Walton1 , Miroslav Styblo1 , Karen Herbin-Davis2, and David J. Thomas2 1 School of Medicine, University of North Carolina at Chape...

  10. Convergent signaling pathways – interaction between methionine oxidation and serine/threonine/tyrosine O-phosphorylation

    Science.gov (United States)

    Oxidation of Methionine (Met) to Met sulfoxide (MetSO) is a frequently found reversible post-translational modification. It has been presumed that the major functional role for oxidation-labile Met residues is to protect proteins/cells from oxidative stress. However, Met oxidation has been establi...

  11. On the Correlation between EPR and Positron Annihilation Measurements on gamma-Irradiated Acetyl Methionine

    DEFF Research Database (Denmark)

    Eldrup, Morten Mostgaard; Lund-Thomsen, E.; Mogensen, O. E.

    1972-01-01

    The dose dependence of the relative EPR signal intensity and positron lifetime spectrum was measured for γ‐irradiated acetyl methionine in the dose range from 0 to 30 Mrad. Angular correlation measurements were performed for the doses 0 and 30 Mrad. The result of the irradiation was the creation...

  12. Tissue nonautonomous effects of fat body methionine metabolism on imaginal disc repair in Drosophila.

    Science.gov (United States)

    Kashio, Soshiro; Obata, Fumiaki; Zhang, Liu; Katsuyama, Tomonori; Chihara, Takahiro; Miura, Masayuki

    2016-02-16

    Regulatory mechanisms for tissue repair and regeneration within damaged tissue have been extensively studied. However, the systemic regulation of tissue repair remains poorly understood. To elucidate tissue nonautonomous control of repair process, it is essential to induce local damage, independent of genetic manipulations in uninjured parts of the body. Herein, we develop a system in Drosophila for spatiotemporal tissue injury using a temperature-sensitive form of diphtheria toxin A domain driven by the Q system to study factors contributing to imaginal disc repair. Using this technique, we demonstrate that methionine metabolism in the fat body, a counterpart of mammalian liver and adipose tissue, supports the repair processes of wing discs. Local injury to wing discs decreases methionine and S-adenosylmethionine, whereas it increases S-adenosylhomocysteine in the fat body. Fat body-specific genetic manipulation of methionine metabolism results in defective disc repair but does not affect normal wing development. Our data indicate the contribution of tissue interactions to tissue repair in Drosophila, as local damage to wing discs influences fat body metabolism, and proper control of methionine metabolism in the fat body, in turn, affects wing regeneration.

  13. Levels of Key Enzymes of Methionine-Homocysteine Metabolism in Preeclampsia

    Directory of Open Access Journals (Sweden)

    Alejandra Pérez-Sepúlveda

    2013-01-01

    Full Text Available Objective. To evaluate the role of key enzymes in the methionine-homocysteine metabolism (MHM in the physiopathology of preeclampsia (PE. Methods. Plasma and placenta from pregnant women (32 controls and 16 PE patients were analyzed after informed consent. Protein was quantified by western blot. RNA was obtained with RNA purification kit and was quantified by reverse transcritase followed by real-time PCR (RT-qPCR. Identification of the C677T and A1298C methylenetetrahydrofolate reductase (MTHFR single-nucleotide polymorphisms (SNPs and A2756G methionine synthase (MTR SNP was performed using PCR followed by a high-resolution melting (HRM analysis. S-adenosyl methionine (SAM and S-adenosyl homocysteine (SAH were measured in plasma using high-performance liquid chromatography-tandem mass spectrometry (HPLC/MS/MS. The SNP association analysis was carried out using Fisher’s exact test. Statistical analysis was performed using a Mann-Whitney test. Results. RNA expression of MTHFR and MTR was significantly higher in patients with PE as compared with controls. Protein, SAM, and SAH levels showed no significant difference between preeclamptic patients and controls. No statistical differences between controls and PE patients were observed with the different SNPs studied. Conclusion. The RNA expression of MTHFR and MTR is elevated in placentas of PE patients, highlighting a potential compensation mechanism of the methionine-homocysteine metabolism in the physiopathology of this disease.

  14. The First International Mini-Symposium on Methionine Restriction and Lifespan

    Directory of Open Access Journals (Sweden)

    Gene eAbles

    2014-05-01

    Full Text Available It has been 20 years since the Orentreich Foundation for the Advancement of Science, under the leadership Dr. Norman Orentreich, first reported that low methionine (Met ingestion by rats extends lifespan [1]. Since then, several studies have replicated the effects of dietary methionine restriction (MR in delaying age-related diseases [2–5]. We report the abstracts from the First International Mini-Symposium on Methionine Restriction and Lifespan held in Tarrytown, NY last September 2013. The goals were 1 to gather researchers with an interest in methionine restriction and lifespan, 2 to exchange knowledge, 3 to generate ideas for future investigations, and 4 to strengthen relationships within this community. The presentations highlighted the importance of research on cysteine, growth hormone (GH, and ATF4 in the paradigm of aging. In addition, the effects of dietary restriction or MR in the kidneys, liver, bones and the adipose tissue were discussed. The symposium also emphasized the value of other species, e.g. the naked mole rat, Brandt’s bat and drosophila in aging research. Overall, the symposium consolidated scientists with similar research interests and provided opportunities to conduct future collaborative studies.

  15. Dietary intake of B vitamins and methionine and colorectal cancer risk.

    Science.gov (United States)

    Bassett, Julie K; Severi, Gianluca; Hodge, Allison M; Baglietto, Laura; Hopper, John L; English, Dallas R; Giles, Graham G

    2013-01-01

    B vitamins are involved in 1-carbon metabolism, which is necessary for DNA replication, DNA repair, and regulation of gene expression. Recent studies suggest inverse associations between folate and vitamin B6 intakes and colorectal cancer risk but associations with other B vitamins and methionine have not been widely studied. After following 14,645 men and 22,467 women for 15 yr on average, we ascertained 910 incident colorectal cancers. Dietary intakes were estimated using a 121-item food frequency questionnaire. Hazard ratios (HRs) and 95% confidence intervals were estimated using Cox regression. We found some evidence of a U-shaped relationship between colon cancer risk and vitamin B6 and an inverse U-shaped relationship between rectal cancer risk and B12 (test for the quadratic trend, P = 0.005 and P = 0.0005 respectively). For colon cancer, we observed a reduced risk associated with low methionine/high folate, HR = 0.63 (0.49, 0.80) and an increased risk associated with high methionine/high folate, HR = 1.36 (1.06, 1.74) (P interaction cancer risk and vitamin B6 intake and an inverse U-shaped association between rectal cancer risk and vitamin B12. Adequate folate intake might protect against colon cancer risk in those with low methionine intake.

  16. Modulatory effect of curcumin on methionine-induced hyperlipidemia and hyperhomocysteinemia in albino rats.

    Science.gov (United States)

    Kapoor, Puneet; Ansari, M Nazam; Bhandari, Uma

    2008-07-01

    The present study was designed to investigate the antioxidant effect of curcumin on methionine-induced hyperlipidemia and hyperhomocysteinemia in Wistar rats (200-250 g) of either sex. The vehicle control rats were treated with 1% Tween 80 in normal saline (2 ml/kg, po) for 30 days. Hyperlipidemia and hyperhomocysteinemia was induced by methionine administration (1 g/kg, po) for 30 days. A significant increase in total cholesterol, triglycerides, low density lipoprotein cholesterol (LDL-C) and homocysteine levels in serum and thiobarbituric acid reactive substances (TBARS) levels in heart homogenates were observed with a concomitant decrease in serum high density lipoprotein (HDL-C) levels in pathogenic control (i.e. group II) rats, as compared to vehicle control (i.e. group I) rats. Further, curcumin (200 mg/kg, p.o.) treatment in methionine treated rats for 30 days significantly decreased the total cholesterol, triglycerides, LDL-C and homocysteine levels in serum and TBARS levels in heart homogenates and increased serum HDL-C levels, as compared to pathogenic control (i.e. group II) rats. The results of biochemical observations were supplemented by histopathological examination of rat's aortic section. The results of test drug were comparable to that obtained with folic acid (100 mg/kg, p.o.). The results suggest that curcumin has significant antihyperlipidemic and antihyperhomocysteinemic effect against methionine-induced hyperlipidemia and hyperhomocysteinemia in rats.

  17. Egg Production and Quality of Quails Fed Diets with Varying Levels of Methionine and Choline Chloride

    Directory of Open Access Journals (Sweden)

    Khairani

    2016-04-01

    Full Text Available The aim of the present study was to determine the effect of choline chloride supplementation at 1500 ppm in diets containing various levels of methionine on egg production and egg quality in quails. A total of 180 birds, at 6 week-old quail were divided into 18 experimental units, and assigned to a 2 x 3 factorial design experiment with 3 replications (10 birds each in each treatment. The birds were offered diets containing choline chloride at either 0 (A1 or 1500 ppm (A2, with three levels of methionine namely, low (0.19%, B1, standard (0.79%, B2 and, high (1.05%, B3. The feeding trial lasted for 8 weeks. Supplementation of choline chloride in low methionine diet significantly (P<0.05 increased egg production, egg mass, and egg weight as compared to those without choline chloride supplementation. Supplementation of choline chloride significantly (P<0.05 increased egg yolk weight but decreased albumen and egg shell weight as compared to those fed diets without choline chloride supplementation. It can be concluded that supplementation of choline chloride to a diet containing low methionine increased egg production, without affecting egg quality.

  18. Acceleration of Selenium Volatilization in Seleniferous Agricultural Drainage Sediments Amended With Methionine and Casein.

    Science.gov (United States)

    Phytoremediation is a potential tool for the management of excessive Se in drainage sediment residing in the San Luis Drain in central California via plant extraction or biological volatilization of Se. This two-year field study in 2004/2005 examined the ability of organic amendments-methionine and ...

  19. Synthesis and evaluation of [11C]PyrATP-1, a novel radiotracer for PET imaging of glycogen synthase kinase-3β (GSK-3β)

    International Nuclear Information System (INIS)

    Introduction: The dysfunction of glycogen synthase kinase-3β (GSK-3β) has been implicated in a number of diseases, including Alzheimer’s disease. The ability to non-invasively quantify GSK-3β activity in vivo is therefore of critical importance, and this work is focused upon development of inhibitors of GSK-3β radiolabeled with carbon-11 to examine quantification of the enzyme using positron emission tomography (PET) imaging. Methods: 11C PyrATP-1 was prepared from the corresponding desmethyl-piperazine precursor in an automated synthesis module. In vivo rodent and primate imaging studies were conducted on a Concorde MicroPET P4 scanner to evaluate imaging properties and in vitro autoradiography studies with rat brain samples were carried out to examine specific binding. Results: 2035 ± 518 MBq (55 ± 14 mCi) of [11C]PyrATP-1 was obtained (1%–2% non-corrected radiochemical yield at end-of-synthesis based upon [11C]CO2) with high chemical (> 95%) and radiochemical (> 99%) purities, and good specific activities (143 ± 52 GBq/μmol (3874 ± 1424 Ci/mmol)), n = 5. In vivo microPET imaging studies revealed poor brain uptake in rodents and non-human primates. Pretreatment of rodents with cyclosporin A resulted in moderately increased brain uptake suggesting Pgp transporter involvement. Autoradiography demonstrated high levels of specific binding in areas of the rodent brain known to be rich in GSK-3β. Conclusion: 11C PyrATP-1 is readily synthesized using standard carbon-11 radiochemistry. However the poor brain uptake in rodents and non-human primates indicates that the radiotracer is not suitable for the purposes of quantifying GSK-3β in neurological and psychiatric disorders

  20. FDG-PET imaging in hematological malignancies.

    Science.gov (United States)

    Valls, L; Badve, C; Avril, S; Herrmann, K; Faulhaber, P; O'Donnell, J; Avril, N

    2016-07-01

    The majority of aggressive lymphomas is characterized by an up regulated glycolytic activity, which enables the visualization by F-18 FDG-PET/CT. One-stop hybrid FDG-PET/CT combines the functional and morphologic information, outperforming both, CT and FDG-PET as separate imaging modalities. This has resulted in several recommendations using FDG-PET/CT for staging, restaging, monitoring during therapy, and assessment of treatment response as well as identification of malignant transformation. FDG-PET/CT may obviate the need for a bone marrow biopsy in patients with Hodgkin's lymphoma and diffuse large B cell lymphoma. FDG-PET/CT response assessment is recommended for FDG-avid lymphomas, whereas CT-based response evaluation remains important in lymphomas with low or variable FDG avidity. The treatment induced change in metabolic activity allows for assessment of response after completion of therapy as well as prediction of outcome early during therapy. The five-point scale Deauville Criteria allows the assessment of treatment response based on visual FDG-PET analysis. Although the use of FDG-PET/CT for prediction of therapeutic response is promising it should only be conducted in the context of clinical trials. Surveillance FDG-PET/CT after complete remission is discouraged due to the relative high number of false-positive findings, which in turn may result in further unnecessary investigations. Future directions include the use of new PET tracers such as F-18 fluorothymidine (FLT), a surrogate biomarker of cellular proliferation and Ga-68 CXCR4, a chemokine receptor imaging biomarker as well as innovative digital PET/CT and PET/MRI techniques. PMID:27090170

  1. PET-CT imaging in pediatric oncology

    OpenAIRE

    McCarville, M. Beth

    2009-01-01

    Abstract Positron emission tomography (PET)-computed tomography (CT) is emerging as a valuable tool for assessing a wide variety of pediatric malignancies, including lymphomas, soft-tissue tumors, and bone sarcomas. PET-CT may provide information that is not apparent on conventional imaging performed to stage these diseases and monitor their response to treatment. The use of PET-CT in children requires an awareness of the technical and logistical issues unique to this patient population. In a...

  2. PET/MR: a paradigm shift

    OpenAIRE

    Gaertner, Florian C.; Furst, Sebastian; Schwaiger, Markus

    2013-01-01

    Abstract More than a decade ago, multimodality imaging was introduced into clinical routine with the development of the positron emission tomography (PET)/computed tomography (CT) technique. Since then, PET/CT has been widely accepted in clinical imaging and has emerged as one of the main cancer imaging modalities. With the recent development of combined PET/magnetic resonance (MR) systems for clinical use, a promising new hybrid imaging modality is now becoming increasingly available. The co...

  3. Pet Ownership and Evacuation Prior to Hurricane Irene.

    Science.gov (United States)

    Hunt, Melissa G; Bogue, Kelsey; Rohrbaugh, Nick

    2012-01-01

    Pet ownership has historically been one of the biggest risk factors for evacuation failure prior to natural disasters. The forced abandonment of pets during Hurricane Katrina in 2005 made national headlines and led to the passage of the Pet Evacuation and Transportation Standards Act (PETS, 2006) which mandated local authorities to plan for companion animal evacuation. Hurricane Irene hit the East Coast of the United States in 2011, providing an excellent opportunity to examine the impact of the PETS legislation on frequency and ease of evacuation among pet owners and non-pet owners. Ninety pet owners and 27 non-pet owners who lived in mandatory evacuation zones completed questionnaires assessing their experiences during the hurricane and symptoms of depression, PTSD, dissociative experiences, and acute stress. Pet ownership was not found to be a statistical risk factor for evacuation failure. However, many pet owners who failed to evacuate continue to cite pet related reasons. PMID:26487162

  4. Pet Ownership and Evacuation Prior to Hurricane Irene

    Directory of Open Access Journals (Sweden)

    Nick Rohrbaugh

    2012-09-01

    Full Text Available Pet ownership has historically been one of the biggest risk factors for evacuation failure prior to natural disasters. The forced abandonment of pets during Hurricane Katrina in 2005 made national headlines and led to the passage of the Pet Evacuation and Transportation Standards Act (PETS, 2006 which mandated local authorities to plan for companion animal evacuation. Hurricane Irene hit the East Coast of the United States in 2011, providing an excellent opportunity to examine the impact of the PETS legislation on frequency and ease of evacuation among pet owners and non-pet owners. Ninety pet owners and 27 non-pet owners who lived in mandatory evacuation zones completed questionnaires assessing their experiences during the hurricane and symptoms of depression, PTSD, dissociative experiences, and acute stress. Pet ownership was not found to be a statistical risk factor for evacuation failure. However, many pet owners who failed to evacuate continue to cite pet related reasons.

  5. Methionine as a potential precursor for halogenated compounds by the reaction with iron minerals

    Science.gov (United States)

    Tubbesing, C.; Krause, T.; Mulder, I.; Kotte, K.; Schöler, H. F.

    2012-04-01

    Volatile halogenated compounds (VOX) play an important role in different photochemical reactions within the troposphere and the stratosphere. Soils and sediments seem to act as a major natural source for VOX, but investigations of the reaction mechanisms are rather scarce. To get further information on potential intermediates the reaction of the amino acid methionine with the ferrous and ferric iron minerals pyrite and ferrihydrite as well as solute ferrous sulfate was studied using a gas chromatography-flame ionization detector (GC-FID). Methionine is an important amino acid in the biosynthesis of plants used as a starting compound for the messenger ethene with aminocyclopropane carboxylic acid as an intermediate product. This pathway may also occur under abiotic conditions. Ethene is assumed as precursor for various halogenated C2-compounds like vinyl chloride and dichloroethene. Due to its ubiquity by an average concentration of 10 to 290 ng/g soil and its potential to regenerate in soils and organic litter by microorganisms, methionine may be an important educt for both abiotic and biotic terrestrial halogenation processes. In laboratory tests methionine was exposed to different iron species like pyrite, iron sulfate or ferrihydrite. The oxidant H2O2 was used to start the reaction. Production values of methyl chloride and other halogenated compounds are discussed in the context of methionine as their potential precursor and several Fe-minerals as soil-borne catalysers. Several possible intermediates for the production of VOX have been detected e.g. methane, ethene or propane. A formation of isobutylene is noteworthy for some cases. In addition to VOC the production of methyl chloride and dimethyl sulfide (DMS) was observed. Only the DMS bears upon a specific mineral. The samples containing pyrite reveal the highest concentrations. To get a better assessment of methionine, respectively VOC released from methionine as precursors for halogenated compounds

  6. Biodistribution of the radionuclides (18)F-FDG, (11)C-methionine, (11)C-PK11195, and (68)Ga-citrate in domestic juvenile female pigs and morphological and molecular imaging of the tracers in hematogenously disseminated Staphylococcus aureus lesions.

    Science.gov (United States)

    Afzelius, Pia; Nielsen, Ole L; Alstrup, Aage Ko; Bender, Dirk; Leifsson, Páll S; Jensen, Svend B; Schønheyder, Henrik C

    2016-01-01

    Approximately 5-7% of acute-care patients suffer from bacteremia. Bacteremia may give rise to bacterial spread to different tissues. Conventional imaging procedures as X-ray, Computed Tomography (CT), Magnetic Resonance Imaging (MRI), and ultrasound are often first-line imaging methods for identification and localization of infection. These methods are, however, not always successful. Early identification and localization of infection is critical for the appropriate and timely selection of therapy. The aim of this study was thus; a head to head comparison of (18)F-fluorodeoxyglucose ((18)F-FDG) positron emission tomography (PET) to PET with tracers that potentially could improve uncovering of infectious lesions in soft tissues. We chose (11)C-methionine, (11)C-PK11195, and (68)Ga-citrate as tracers and besides presenting their bio-distribution we validated their diagnostic utility in pigs with experimental bacterial infection. Four juvenile 14-15 weeks old female domestic pigs were scanned seven days after intra-arterial inoculation in the right femoral artery with a porcine strain of S. aureus using a sequential scanning protocol with (18)F-FDG, (11)C-methionine, (11)C-PK11195 and (68)Ga-citrate. This was followed by necropsy of the pigs consisting of gross pathology, histopathology and microbial examination. The pigs primarily developed lesions in lungs and neck muscles. (18)F-FDG had higher infection to background ratios and accumulated in most infectious foci caused by S. aureus, while (11)C-methionine and particularly (11)C-PK11195 and (68)Ga-citrate accumulated to a lesser extent in infectious foci. (18)F-FDG-uptake was seen in the areas of inflammatory cells and to a much lesser extent in reparative infiltration surrounding necrotic regions. PMID:27069765

  7. Proton Therapy Verification with PET Imaging

    Science.gov (United States)

    Zhu, Xuping; Fakhri, Georges El

    2013-01-01

    Proton therapy is very sensitive to uncertainties introduced during treatment planning and dose delivery. PET imaging of proton induced positron emitter distributions is the only practical approach for in vivo, in situ verification of proton therapy. This article reviews the current status of proton therapy verification with PET imaging. The different data detecting systems (in-beam, in-room and off-line PET), calculation methods for the prediction of proton induced PET activity distributions, and approaches for data evaluation are discussed. PMID:24312147

  8. PET/MR Imaging in Heart Disease.

    Science.gov (United States)

    Rischpler, Christoph; Nekolla, Stephan G

    2016-10-01

    Hybrid PET/MR imaging is a complex imaging modality that has raised high expectations not only for oncological and neurologic imaging applications, but also for cardiac imaging applications. Initially, physicians and physicists had to become accustomed to technical challenges including attenuation correction, gating, and more complex workflow and more elaborate image analysis as compared with PET/CT or standalone MR imaging. PET/MR imaging seems to be particularly valuable to assess inflammatory myocardial diseases (such as sarcoidosis), to cross-validate PET versus MR imaging data (eg, myocardial perfusion imaging), and to help validate novel biomarkers of various disease states (eg, postinfarction inflammation). PMID:27593250

  9. Advances in time-of-flight PET.

    Science.gov (United States)

    Surti, Suleman; Karp, Joel S

    2016-01-01

    This paper provides a review and an update on time-of-flight PET imaging with a focus on PET instrumentation, ranging from hardware design to software algorithms. We first present a short introduction to PET, followed by a description of TOF PET imaging and its history from the early days. Next, we introduce the current state-of-art in TOF PET technology and briefly summarize the benefits of TOF PET imaging. This is followed by a discussion of the various technological advancements in hardware (scintillators, photo-sensors, electronics) and software (image reconstruction) that have led to the current widespread use of TOF PET technology, and future developments that have the potential for further improvements in the TOF imaging performance. We conclude with a discussion of some new research areas that have opened up in PET imaging as a result of having good system timing resolution, ranging from new algorithms for attenuation correction, through efficient system calibration techniques, to potential for new PET system designs.

  10. The role of PET in thyroid cancer

    Energy Technology Data Exchange (ETDEWEB)

    Seok, Yeo Jeong [College of Medicine, Ulsan Univ., Seoul (Korea, Republic of)

    2002-06-01

    The role of PET in the diagnosis and management of thyroid cancer is discussed. The major role of F-18 FDG PET is in patients with discordant negative I-131 scan and a positive serum thyroglobulin values. F-18 FDG PET scan localized metastatic sites in I-131 scan-negative thyroid carcinoma patients with high accuracy. F-18 PET is also valuable in medullary thyroid cancer with high calcitonin level. Focal thyroid uptake in patients with non-thyroidal disease has high likelihood of thyroid cancer.

  11. Dynamic observation by PET in epilepsy

    International Nuclear Information System (INIS)

    Before the era when positron emission tomography (PET) has emerged, much controversy has existed concerning regional cerebral blood flow in partial epilepsy. In 1979, PET revealed that cerebral blood flow is decreased during the interictal period, but is remarkably increased in the intraictal phase. In this paper, historical process of dynamic observation in epilepsy is reviewed. Potential use and limitations of PET in the clinical setting are discussed in view of the scanning methods and the relationships between PET and electroencephalograms, magnetic resonance imaging, and surgical treatment. (N.K.) 106 refs

  12. PET-Computed Tomography in Veterinary Medicine.

    Science.gov (United States)

    Randall, Elissa K

    2016-05-01

    PET/CT is an advanced imaging modality that is becoming more commonly used in veterinary medicine. It is most commonly used to image patients with cancer, and the most frequently used radiopharmaceutical is F-18 FDG. F-18 FDG is a glucose analog that highlights areas of increased glucose metabolism on the PET images. CT images provide excellent anatomic depiction and aid in interpretation of the PET data. Many types of cancer are hypermetabolic on PET/CT scans, but normal structures and areas of inflammation are also hypermetabolic, so knowledge of normal imaging and cytologic or histopathologic evaluation of lesions is essential.

  13. Uptake of positron emission tomography tracers in experimental bacterial infections: a comparative biodistribution study of radiolabeled FDG, thymidine, l-methionine, {sup 67}Ga-citrate, and {sup 125}I-HSA

    Energy Technology Data Exchange (ETDEWEB)

    Sugawara, Y.; Gutowski, T.D.; Fisher, S.J.; Brown, R.S. [Michigan Univ., Ann Arbor (United States). Medical Center; Wahl, R.L. [Michigan Univ., Ann Arbor (United States). Medical Center]|[Department of Radiology, University of Michigan Medical Center, Ann Arbor (United States)

    1999-04-29

    The purpose of this study was to evaluate the localization of positron emission tomography (PET) tracers [2-deoxy-2-fluoro-d-glucose (FDG), thymidine, and l-methionine] in sites of bacterial infection, and to contrast this with that of other tracers. The left calf muscles of rats were infected with a suspension of Escherichia coli and the biodistribution of {sup 18}F- or {sup 3}H-FDG, {sup 3}H-thymidine, l-{sup 11}C- or {sup 3}H-methionine, gallium-67 citrate ({sup 67}Ga-citrate) and iodine-125 human serum albumin ({sup 125}I-HSA) was determined in these animals. {sup 3}H-FDG uptake in the infectious foci was evaluated by autoradiography of histological sections. Although {sup 18}F-FDG, {sup 67}Ga-citrate, and {sup 125}I-HSA showed comparatively high uptake in the infected muscle [the percentage activity of injected dose (ID) per gram of tissue normalized for rat weight in kilogram (%ID/g) x kg at 2 h postinjection was as follows: {sup 18}F-FDG, 0.184{+-}0.026 to 0.218{+-}0.046; {sup 67}Ga-citrate, 0.221{+-}0.016; {sup 125}I-HSA, 0.198{+-}0.019], the infected muscle to blood ratio was much higher for {sup 18}F-FDG than for {sup 67}Ga-citrate or {sup 125}I-HSA ({sup 18}F-FDG, 10.31{+-}0.76 to 14.89{+-}2.26; {sup 67}Ga-citrate, 1.24{+-}0.67; {sup 125}I-HSA, 0.20{+-}0.02). The draining reactive lymph nodes also showed higher accumulation of {sup 18}F-FDG than of {sup 67}Ga-citrate or {sup 125}I-HSA. The uptake of {sup 3}H-thymidine and l-{sup 11}C- or {sup 3}H-methionine in the infected muscle was lower than that of {sup 18}F- or {sup 3}H-FDG at 2 h postinjection, {sup 3}H-thymidine = 0.039{+-}0.005 and L-{sup 3}H-methionine = 0.063{+-}0.007 (%ID/g) x kg. Autoradiographs showed that the highest {sup 3}H-FDG uptake was seen in the area of inflammatory cell infiltration surrounding the necrotic region. In conclusion, {sup 18}F-FDG, which rapidly accumulates in sites of bacterial infection and in reactive lymph nodes with a high target to background ratio, appears to be

  14. Methionine- and choline-deficient diet induces hepatic changes characteristic of non-alcoholic steatohepatitis

    Directory of Open Access Journals (Sweden)

    Éder Marcolin

    2011-03-01

    Full Text Available CONTEXT: Non-alcoholic steatohepatitis is a disease with a high incidence, difficult diagnosis, and as yet no effective treatment. So, the use of experimental models for non-alcoholic steatohepatitis induction and the study of its routes of development have been studied. OBJECTIVES: This study was designed to develop an experimental model of non-alcoholic steatohepatitis based on a methionine- and choline-deficient diet that is manufactured in Brazil so as to evaluate the liver alterations resulting from the disorder. METHODS: Thirty male C57BL6 mice divided in two groups (n = 15 were used: the experimental group fed a methionine- and choline-deficient diet manufactured by Brazilian company PragSoluções®, and the control group fed a normal diet, for a period of 2 weeks. The animals were then killed by exsanguination to sample blood for systemic biochemical analyses, and subsequently submitted to laparotomy with total hepatectomy and preparation of the material for histological analysis. The statistical analysis was done using the Student's t-test for independent samples, with significance level of 5%. RESULTS: The mice that received the methionine- and choline-deficient diet showed weight loss and significant increase in hepatic damage enzymes, as well as decreased systemic levels of glycemia, triglycerides, total cholesterol, HDL and VLDL. The diagnosis of non-alcoholic steatohepatitis was performed in 100% of the mice that were fed the methionine- and choline-deficient diet. All non-alcoholic steatohepatitis animals showed some degree of macrovesicular steatosis, ballooning, and inflammatory process. None of the animals which were fed the control diet presented histological alterations. All non-alcoholic steatohepatitis animals showed significantly increased lipoperoxidation and antioxidant enzyme GSH activity. CONCLUSION: The low cost and easily accessible methionine- and choline-deficient diet explored in this study is highly effective in

  15. Utilization of zinc methionine supplementation in Friesian cows: somatic cell count in milk and mastitis

    International Nuclear Information System (INIS)

    Full text: Two hundreds and forty lactating Friesian cows on the 1st to 8th of lactation and different stages of lactation were used to study some factors affecting on somatic cell count and its effects on milk yield and composition. Also, 12 normal cows, 15 subclinical and 15 clinical mastitis cows were used to study the effect of zinc methionine supplementation on somatic cell count and mastitis. Cows were divided into three similar groups, the first groups was unsupplemented, while the second and third groups were supplemented with 5 and 10 gm zinc methionine / head / day, respectively. Subclinical and clinical mastitis cows were intramammary injected by antibiotic Gentamast (Gentamicin 100 mg) till complete recovery. The obtained results showed that winter season showed significantly (P < 0.05) the highest somatic cell count followed by summer season, while the lowest value was in autumn season. Somatic cell count tended to decrease with the progress of lactation up to the peak period and increased significantly (P < 0.05) thereafter and also with the progress number of lactation. The percentages of normal, subclinical and clinical mastitis cows were 77.71, 15.82 and 6.46%, respectively. Milk yield and composition and its output decreased significantly (P < 0.05) with increasing somatic cell count. Zinc methionine supplementation resulted in significant (P < 0.05) decrease in somatic cell count in milk. Zinc methionine supplementation for subclinical and clinical mastitis cows led to significant decrease (P < 0.05) on somatic cell count, electrical conductivity, recovery time and the cost of therapy compared with unsupplemented group. It could be concluded that increasing somatic cell count decreased milk yield and composition. Zinc methionine supplementation at the level of 5 g per head daily to lactating Friesian cows reduced somatic cell count in milk, recovery time and therapy cost of mastitis. (author)

  16. Methionine sulfoxide profiling of milk proteins to assess the influence of lipids on protein oxidation in milk.

    Science.gov (United States)

    Wüst, Johannes; Pischetsrieder, Monika

    2016-06-15

    Thermal treatment of milk and milk products leads to protein oxidation, mainly the formation of methionine sulfoxide. Reactive oxygen species, responsible for the oxidation, can be generated by Maillard reaction, autoxidation of sugars, or lipid peroxidation. The present study investigated the influence of milk fat on methionine oxidation in milk. For this purpose, quantitative methionine sulfoxide profiling of all ten methionine residues of β-lactoglobulin, α-lactalbumin, and αs1-casein was carried out by ultrahigh-performance liquid chromatography-electrospray ionization tandem mass spectrometry with scheduled multiple reaction monitoring (UHPLC-ESI-MS/MS-sMRM). Analysis of defatted and regular raw milk samples after heating for up to 8 min at 120 °C and analysis of ultrahigh-temperature milk samples with 0.1%, 1.5%, and 3.5% fat revealed that methionine oxidation of the five residues of the whey proteins and of residues M 123, M 135, and M 196 of αs1-casein was not affected or even suppressed in the presence of milk fat. Only the oxidation of residues M 54 and M 60 of αs1-casein was promoted by lipids. In evaporated milk samples, formation of methionine sulfoxide was hardly influenced by the fat content of the samples. Thus, it can be concluded that lipid oxidation products are not the major cause of methionine oxidation in milk.

  17. Antitumor effect of methionine-depleting total parenteral nutrition with doxorubicin administration on Yoshida sarcoma-bearing rats.

    Science.gov (United States)

    Goseki, N; Yamazaki, S; Endo, M; Onodera, T; Kosaki, G; Hibino, Y; Kuwahata, T

    1992-04-01

    Methionine-depleting total parenteral nutrition (methionine-depleting TPN), which infuses an amino acid solution devoid of L-methionine and L-cysteine as the sole protein source, showed enhancement of the effect of several anti-cancer agents. In this study, the combined effect of the methionine-depleting TPN with the administration of doxorubicin was examined in Yoshida sarcoma (YS)-bearing rats with regard to effects on the primary tumor growth, the extension of metastasis, and the host animal's life span. In the first experiment, immediately after receiving methionine-depleting TPN for 8 days, the animals were killed. Pathologic findings evaluated tumor growth in the implanted site and extension of the metastasis. In the second experiment, the survival period was determined after animals received methionine-depleting TPN for 10 days, with subsequent oral feeding until they died naturally. Proliferation of YS was markedly suppressed. In particular, hematogenous metastasis, which is a characteristic of YS, was suppressed, and a longer survival period (42.7 +/- 15.6 days, mean +/- SD) was attained in rats in the group treated with the methionine-depleting TPN combined with the administration of doxorubicin.

  18. Methionine sulfoxide profiling of milk proteins to assess the influence of lipids on protein oxidation in milk.

    Science.gov (United States)

    Wüst, Johannes; Pischetsrieder, Monika

    2016-06-15

    Thermal treatment of milk and milk products leads to protein oxidation, mainly the formation of methionine sulfoxide. Reactive oxygen species, responsible for the oxidation, can be generated by Maillard reaction, autoxidation of sugars, or lipid peroxidation. The present study investigated the influence of milk fat on methionine oxidation in milk. For this purpose, quantitative methionine sulfoxide profiling of all ten methionine residues of β-lactoglobulin, α-lactalbumin, and αs1-casein was carried out by ultrahigh-performance liquid chromatography-electrospray ionization tandem mass spectrometry with scheduled multiple reaction monitoring (UHPLC-ESI-MS/MS-sMRM). Analysis of defatted and regular raw milk samples after heating for up to 8 min at 120 °C and analysis of ultrahigh-temperature milk samples with 0.1%, 1.5%, and 3.5% fat revealed that methionine oxidation of the five residues of the whey proteins and of residues M 123, M 135, and M 196 of αs1-casein was not affected or even suppressed in the presence of milk fat. Only the oxidation of residues M 54 and M 60 of αs1-casein was promoted by lipids. In evaporated milk samples, formation of methionine sulfoxide was hardly influenced by the fat content of the samples. Thus, it can be concluded that lipid oxidation products are not the major cause of methionine oxidation in milk. PMID:26927981

  19. Functional identification of APIP as human mtnB, a key enzyme in the methionine salvage pathway.

    Directory of Open Access Journals (Sweden)

    Camille Mary

    Full Text Available The methionine salvage pathway is widely distributed among some eubacteria, yeast, plants and animals and recycles the sulfur-containing metabolite 5-methylthioadenosine (MTA to methionine. In eukaryotic cells, the methionine salvage pathway takes place in the cytosol and usually involves six enzymatic activities: MTA phosphorylase (MTAP, EC 2.4.2.28, 5'-methylthioribose-1-phosphate isomerase (mtnA, EC 5.3.1.23, 5'-methylthioribulose-1-phosphate dehydratase (mtnB, EC: 4.2.1.109, 2,3-dioxomethiopentane-1-phosphate enolase/phosphatase (mtnC, EC 3.1.3.77, aci-reductone dioxygenase (mtnD, EC 1.13.11.54 and 4-methylthio-2-oxo-butanoate (MTOB transaminase (EC 2.6.1.-. The aim of this study was to complete the available information on the methionine salvage pathway in human by identifying the enzyme responsible for the dehydratase step. Using a bioinformatics approach, we propose that a protein called APIP could perform this role. The involvement of this protein in the methionine salvage pathway was investigated directly in HeLa cells by transient and stable short hairpin RNA interference. We show that APIP depletion specifically impaired the capacity of cells to grow in media where methionine is replaced by MTA. Using a Shigella mutant auxotroph for methionine, we confirm that the knockdown of APIP specifically affects the recycling of methionine. We also show that mutation of three potential phosphorylation sites does not affect APIP activity whereas mutation of the potential zinc binding site completely abrogates it. Finally, we show that the N-terminal region of APIP that is missing in the short isoform is required for activity. Together, these results confirm the involvement of APIP in the methionine salvage pathway, which plays a key role in many biological functions like cancer, apoptosis, microbial proliferation and inflammation.

  20. {sup 18}F-FDG PET and PET/CT in Burkitt's lymphoma

    Energy Technology Data Exchange (ETDEWEB)

    Karantanis, Dimitrios, E-mail: dkarantanis@nuclmed.ne [Division of Nuclear Medicine, Department of Radiology, Mayo Clinic, Rochester, MN (United States); Durski, Jolanta M.; Lowe, Val J.; Nathan, Mark A.; Mullan, Brian P. [Division of Nuclear Medicine, Department of Radiology, Mayo Clinic, Rochester, MN (United States); Georgiou, Evangelos [Medical Physics Department, Medical School, University of Athens (Greece); Johnston, Patrick B. [Division of Hematology, Department of Medicine, Mayo Clinic, Rochester, MN (United States); Wiseman, Gregory A. [Division of Nuclear Medicine, Department of Radiology, Mayo Clinic, Rochester, MN (United States)

    2010-07-15

    Objective: To explore the value of {sup 18}F fluorodeoxy-glucose (FDG) positron emission tomography (PET) in Burkitt's lymphoma. Methods: All Burkitt's lymphoma patients referred for FDG PET or FDG PET/computed tomography (CT) exams at our institution from June 2003 to June 2006 were included. Selected patients were followed and clinical information was reviewed retrospectively. Results from FDG PET-PET/CT, as blindly reviewed by a consensus of two experienced readers, were compared with the status of the disease as determined by other laboratory, clinical and imaging exams and clinical follow-up. FDG PET-PET/CT results were classified as true positive or negative and false positive or negative. The degree of FDG uptake in the positive lesions was semiquantified as maximum standard uptake value (SUVmax). Results: Fifty-seven FDG PET-PET/CT exams were done in 15 patients. Seven exams were done for initial staging, 8 during and 14 after the completion of therapy, and 28 for disease surveillance. For nodal disease FDG PET-PET/CT was true positive in 8, true negative in 47 and false positive in 2 exams (sensitivity 100%, specificity 96%). For extranodal disease FDG PET-PET/CT was true positive in 6, true negative in 48 and false positive in 3 exams (sensitivity 100%, specificity 94%). The mean SUVmax for the positive nodal lesions was 15.7 (range 6.9-21.7, median 18.5) and for extranodal lesions was 14.2 (range 6.2-24.3, median 12.4). Conclusions: FDG PET-PET/CT is sensitive for the detection of viable disease in Burkitt's lymphoma. Affected areas demonstrated high degree of uptake that was reversible upon successful implementation of treatment.

  1. The Methionine Transamination Pathway Controls Hepatic Glucose Metabolism through Regulation of the GCN5 Acetyltransferase and the PGC-1α Transcriptional Coactivator.

    Science.gov (United States)

    Tavares, Clint D J; Sharabi, Kfir; Dominy, John E; Lee, Yoonjin; Isasa, Marta; Orozco, Jose M; Jedrychowski, Mark P; Kamenecka, Theodore M; Griffin, Patrick R; Gygi, Steven P; Puigserver, Pere

    2016-05-13

    Methionine is an essential sulfur amino acid that is engaged in key cellular functions such as protein synthesis and is a precursor for critical metabolites involved in maintaining cellular homeostasis. In mammals, in response to nutrient conditions, the liver plays a significant role in regulating methionine concentrations by altering its flux through the transmethylation, transsulfuration, and transamination metabolic pathways. A comprehensive understanding of how hepatic methionine metabolism intersects with other regulatory nutrient signaling and transcriptional events is, however, lacking. Here, we show that methionine and derived-sulfur metabolites in the transamination pathway activate the GCN5 acetyltransferase promoting acetylation of the transcriptional coactivator PGC-1α to control hepatic gluconeogenesis. Methionine was the only essential amino acid that rapidly induced PGC-1α acetylation through activating the GCN5 acetyltransferase. Experiments employing metabolic pathway intermediates revealed that methionine transamination, and not the transmethylation or transsulfuration pathways, contributed to methionine-induced PGC-1α acetylation. Moreover, aminooxyacetic acid, a transaminase inhibitor, was able to potently suppress PGC-1α acetylation stimulated by methionine, which was accompanied by predicted alterations in PGC-1α-mediated gluconeogenic gene expression and glucose production in primary murine hepatocytes. Methionine administration in mice likewise induced hepatic PGC-1α acetylation, suppressed the gluconeogenic gene program, and lowered glycemia, indicating that a similar phenomenon occurs in vivo These results highlight a communication between methionine metabolism and PGC-1α-mediated hepatic gluconeogenesis, suggesting that influencing methionine metabolic flux has the potential to be therapeutically exploited for diabetes treatment.

  2. A proposal of an open PET geometry

    Energy Technology Data Exchange (ETDEWEB)

    Yamaya, Taiga [Molecular Imaging Center, National Institute of Radiological Sciences, 4-9-1 Anagawa, Inage-ku, Chiba, 263-8555 (Japan); Inaniwa, Taku [Research Center for Charged Particle Therapy, National Institute of Radiological Sciences, 4-9-1 Anagawa, Inage-ku, Chiba 263-8555 (Japan); Minohara, Shinichi [Research Center for Charged Particle Therapy, National Institute of Radiological Sciences, 4-9-1 Anagawa, Inage-ku, Chiba 263-8555 (Japan); Yoshida, Eiji [Molecular Imaging Center, National Institute of Radiological Sciences, 4-9-1 Anagawa, Inage-ku, Chiba, 263-8555 (Japan); Inadama, Naoko [Molecular Imaging Center, National Institute of Radiological Sciences, 4-9-1 Anagawa, Inage-ku, Chiba, 263-8555 (Japan); Nishikido, Fumihiko [Molecular Imaging Center, National Institute of Radiological Sciences, 4-9-1 Anagawa, Inage-ku, Chiba, 263-8555 (Japan); Shibuya, Kengo [Molecular Imaging Center, National Institute of Radiological Sciences, 4-9-1 Anagawa, Inage-ku, Chiba, 263-8555 (Japan); Lam, Chih Fung [Molecular Imaging Center, National Institute of Radiological Sciences, 4-9-1 Anagawa, Inage-ku, Chiba, 263-8555 (Japan); Murayama, Hideo [Molecular Imaging Center, National Institute of Radiological Sciences, 4-9-1 Anagawa, Inage-ku, Chiba, 263-8555 (Japan)

    2008-02-07

    The long patient port of a PET scanner tends to put stress on patients, especially patients with claustrophobia. It also prevents doctors and technicians from taking care of patients during scanning. In this paper, we proposed an 'open PET' geometry, which consists of two axially separated detector rings. A long and continuous field-of-view (FOV) including a 360 deg. opened gap between two detector rings can be imaged enabling a fully 3D image reconstruction of all the possible lines-of-response. The open PET will become practical if iterative image reconstruction methods are applied even though image reconstruction of the open PET is analytically an incomplete problem. First we implemented a 'masked' 3D ordered subset expectation maximization (OS-EM) in which the system matrix was obtained from a long 'gapless' scanner by applying a mask to detectors corresponding to the open space. Next, in order to evaluate imaging performance of the proposed open PET geometry, we simulated a dual HR+ scanner (ring diameter of D = 827 mm, axial length of W = 154 mm x 2) separated by a variable gap. The gap W was the maximum limit to have axially continuous FOV of 3W though the maximum diameter of FOV at the central slice was limited to D/2. Artifacts, observed on both sides of the open space when the gap exceeded W, were effectively reduced by inserting detectors partially into unnecessary open spaces. We also tested the open PET geometry using experimental data obtained by the jPET-D4. The jPET-D4 is a prototype brain scanner, which has 5 rings of 24 detector blocks. We simulated the open jPET-D4 with a gap of 66 mm by eliminating 1 block-ring from experimental data. Although some artifacts were seen at both ends of the opened gap, very similar images were obtained with and without the gap. The proposed open PET geometry is expected to lead to realization of in-beam PET, which is a method for an in situ monitoring of charged particle therapy, by

  3. Positron emission tomography (PET) in psychiatry. PET in der Psychiatrie

    Energy Technology Data Exchange (ETDEWEB)

    Herholz, K. (Max-Planck-Institut fuer Neurologische Forschung und Neurologische Klinik der Universitaet Koeln (Germany))

    1993-08-13

    Currently, clinical PET is mainly useful in psychiatry and related areas for differential diagnosis of dementia. In dementia of Alzheimer type reductions of glucose metabolism are found mainly in the temporoparietal assocaiton cortex, in Pick's disease mainly in the frontal cortex, and in Huntington's disease in the striatum. Other demential diseases usually show less toposelective metabolic impairment. In the future, new diagnostic possibilities may arise from analysis of functional stimulation of specific brain areas and from the use of ligands for specific neurotransmitter systems. (orig.)

  4. Role of FDG-PET and PET/CT in the diagnosis of prolonged febrile states

    Energy Technology Data Exchange (ETDEWEB)

    Jaruskova, M.; Belohlavek, O. [Na Homolce Hospital, PET Center, Prague 5 (Czech Republic)

    2006-08-15

    The role of FDG-PET and PET/CT in patients whose main symptom is prolonged fever has not yet been defined. We addressed this topic in a retrospective study. A total of 124 patients (referred between May 2001 and December 2004) with fever of unknown origin or prolonged fever due to a suspected infection of a joint or vascular prosthesis were included in the study. The patients underwent either FDG-PET or FDG-PET/CT scanning. Sixty-seven patients had a negative focal FDG-PET finding; in this group the method was regarded as unhelpful in determining a diagnosis, and no further investigation was pursued. We tried to obtain clinical confirmation for all patients with positive PET findings. Fifty-seven (46%) patients had positive FDG-PET findings. In six of them no further clinical information was available. Fifty-one patients with positive PET findings and 118 patients in total were subsequently evaluated. Systemic connective tissue disease was confirmed in 17 patients, lymphoma in three patients, inflammatory bowel disease in two patients, vascular prosthesis infection in seven patients, infection of a hip or knee replacement in seven patients, mycotic aneurysm in two patients, abscess in four patients and AIDS in one patient. In eight (16%) patients the finding was falsely positive. FDG-PET or PET/CT contributed to establishing a final diagnosis in 84% of the 51 patients with positive PET findings and in 36% of all 118 evaluated patients with prolonged fever. (orig.)

  5. PET and PET/CT imaging for the earliest detection and treatment of colorectal carcinoma

    Energy Technology Data Exchange (ETDEWEB)

    Carter, Kevin [Michigan State Univ., Pontiac, MI (United States). POH Medical Center; Kotlyarov, Eduard [Michigan State Univ., Pontiac, MI (United States). POH Medical Center; Georgetown Univ. (United States)

    2005-10-15

    Approximately 150,000 new cases of colorectal cancer are diagnosed each year with the life time risk of developing colon caner in developed nations being 4.6% in men and 3.2% in women. Screening patients is essential early detection of colon carcinoma to aid in complete resection. Unfortunately current screening methods carry with them poor patient compliance. PET and PET/CT may be a significant part of this screening solution. The authors reviewed and analyzed the English language articles and case reports identified on Medline during the last 10 years. PET and PET/CT results for colorectal carcinoma were tabulated and presented for the fifth Scientific Meeting of the Brazilian Society of Nuclear Biosciences. Though most studies have been retrospective analysis in using PET for staging for other malignant processes the cases that have identified additional uptake in the colon are important. The accuracy when utilizing PET and PET/CT in this screening method has a sensitivity between 65 and 90% with a specificity of 84 to 90% and a positive predictive value 71 to 78%. Early stages of malignancies and pre-cancerous polyps avidly accumulates F-18 Deoxyfluoro glucose allowing us to conclude that whole body PET and PET/CT is an essential component in the work up, staging or treatment monitoring in colon carcinoma. We have to continue to accumulate data for possible introduction for whole body PET and PET/CT scanning for colon carcinoma and precancerous polyps.(author)

  6. Bio-efficacy comparison of herbal-methionine and DL-methionine based on performance and blood parameters of broiler chickens

    Directory of Open Access Journals (Sweden)

    Sheila Hadinia

    2014-06-01

    Full Text Available This study was conducted to compare the bio-efficacy of herbal methionine (H-Met relative to DL-methionine (DL-Met on 160 “Ross 308” broiler chickens. DL-Met and H-Met were added to the basal diet in eight experimental treatments with three and four concentrations respectively in starter, grower and finisher period. Blood parameters which were measured at 24 and 42 days of age consisted of: serum proteins (total protein, albumin and globulin, serum uric acid, serum fats (low density lipoprotein, high density lipoprotein, triglyceride and cholesterol and serum enzymes (alanine amino transaminase and aspartate amino transaminase. Completely randomized design, multi-exponential and multilinear regressions were used to determine bio-efficacy of H-Met in terms of performance and blood parameters of broilers. The results showed that supplemented methionine (Met sources had no significant effect on blood parameters at 24 day of age. At 42 day of age the amounts of globulin and serum high density lipoprotein (HDL increased with supplemented Met, (p < 0.05. Regression analysis revealed that H-Met was 55.00, 71.00, 78.00, 47.00, 58.00 and 73.00% as efficacious as DL-Met for body weight gain, feed intake, feed conversion ratio, albumin, globulin and high density lipoprotein criteria, respectively. The average of bio-efficacy of H-Met compared to DL-Met was 67.00% and 59.00% on average across performance criteria and blood criteria respectively and was 63.00% across these two criteria tested. The results of the present study indicated that H-Met can be administered as a new and a natural source of Met in poultry industry.

  7. Inventarisatie van ontwikkelingen van PET-CT

    NARCIS (Netherlands)

    Bijwaard H; LSO; mev

    2011-01-01

    De Nederlandse ziekenhuispraktijk heeft de relatief nieuwe PET-CT-technologie omarmd: het aantal PET-CT-scanners en hun toepassingen nemen snel toe. De toepassingen in de medische praktijk lopen voor op de richtlijnen uit 2007. Voor deze richtlijnen wordt daarom een frequentere update aanbevolen. Vo

  8. Quantitative Techniques in PET-CT Imaging

    NARCIS (Netherlands)

    Basu, Sandip; Zaidi, Habib; Holm, Soren; Alavi, Abass

    2011-01-01

    The appearance of hybrid PET/CT scanners has made quantitative whole body scanning of radioactive tracers feasible. This paper deals with the novel concepts for assessing global organ function and disease activity based on combined functional (PET) and structural (CT or MR) imaging techniques, their

  9. Integrating Pet Therapy into Daily School Life

    Science.gov (United States)

    Brous, Miriam T.

    2010-01-01

    Stories abound in literature of the ways that people and their pets have fostered and created valuable relationships. More recently, research has shown a strong impact from the pet relationship in health-related settings. Positive changes have been seen in people developing resilience, self-reliance, and in making progress in treatment. Children…

  10. Application of PET and PET/CT imaging for cancer screening

    International Nuclear Information System (INIS)

    The aim of this study was to evaluate the potential application of 18F-fluorodeoxyglucose (FDG) Positron Emission Tomography (PET) and PET/CT for cancer screening in asymptomatic individuals. Methods: The subjects consisted of 3631 physical check up examinees (1947 men, 1684 women; mean age ±SD, 52.1±8.2 y) with non-specific medical histories. Whole-body FDG PET (or PET/CT), ultrasound and tumor markers were performed on all patients. Focal hypermetabolic areas with intensities equal to or exceeding the level of FDG uptake in the brain and bladder were considered abnormal and interpreted as neoplasia. Follow-up periods were longer than one year. Results: Among the 3631 FDG PET (including 1687 PET/CT), ultrasound and tumor markers examinations, malignant tumors were discovered in 47 examinees (1.29%). PET findings were true-positive in 38 of the 47 cancers (80.9%). In addition, 32 of the 47 cancers were performed with the PET-CT scan. PET detected cancer lesions in 28 of the 32 examinees. However, the CT detected cancer lesions in only 15 of 32 examinees. Conclusion: The sensitivity of FDG PET in the detection of a wide variety of cancers is high. Most cancer can be detected with FDG PET in a resectable stage. CT of the PET/CT for localization and characteristics of the lesion shows an increased specificity of the PET scan. Using ultrasound and tumor markers may complement the PET scan in cancer screening for hepatic and urologic neoplasms. (authors)

  11. Choline-PET/CT for imaging prostate cancer; Cholin-PET/CT zur Bildgebung des Prostatakarzinoms

    Energy Technology Data Exchange (ETDEWEB)

    Krause, Bernd Joachim [Klinik- und Poliklinik fuer Nuklearmedizin, Klinikum rechts der Isar, Technische Univ. Muenchen (Germany); Treiber, U.; Schwarzenboeck, S.; Souvatzoglou, M. [Klinik fuer Urologie, Klinikum rechts der Isar, Technische Univ. Muenchen (Germany)

    2010-09-15

    PET and PET/CT using [{sup 11}C]- and [{sup 18}F]-labelled choline derivatives are increasingly being used for imaging of prostate cancer. The value of PET and PET/CT with [{sup 11}C]- and [{sup 18}F]-labelled choline derivates in biochemical recurrence of prostate cancer has been examined in many studies and demonstrates an increasing importance. Primary prostate cancer can be detected with moderate sensitivity using PET and PET/CT using [{sup 11}C]- and [{sup 18}F]-labelled choline derivatives - the differentiation between benign prostatic hyperplasia, prostatitis or high-grade intraepithelial neoplasia (HGPIN) is not always possible. At the present time [{sup 11}C]choline PET/CT is not recommended in the primary setting but may be utilized in clinically suspected prostate cancer with repeatedly negative prostate biopsies, in preparation of a focused re-biopsy. Promising results have been obtained for the use of PET and PET/CT with [{sup 11}C]- and [{sup 18}F]-labelled choline derivates in patients with biochemical recurrence. The detection rate of choline PET and PET/CT for local, regional, and distant recurrence in patients with a biochemical recurrence shows a linear correlation with PSA values at the time of imaging and reaches about 75% in patients with PSA > 3 ng/mL. At PSA values below 1 ng/mL, the recurrence can be diagnosed with choline PET/CT in approximately 1/3 of the patients. PET and PET/CT with [{sup 11}C]- and [{sup 18}F]choline derivates can be helpful for choosing a therapeutic strategy in the sense of an individualized treatment: since an early diagnosis of recurrence is crucial to the choice of optimal treatment. The localization of the site of recurrence - local recurrence, lymph node metastasis or systemic dissemination - has important influence on the therapy regimen. (orig.)

  12. Can pets function as family members?

    Science.gov (United States)

    Cohen, Susan Phillips

    2002-10-01

    This exploratory study investigated how clients of a large urban veterinary center viewed the role of their pet in the famil and how they compared this role to that of humans. In Phase 1, randomly selected clients (N = 201) completed a questionnaire containing scales delineating family relationships and pet attachment. Being either a man or a college graduate was associated with lesser feelings of psychological kinship and intimacy, both with pets and people. Neither living with a partner norhaving a child affected the strength of pet relationships. In Phase 2, 16 participants from Phase I completed a social network instrument and answered questions about family roles and boundaries. Thirteen of the 16 respondents said that there were circumstances in which they would give a scarce drug to their pet in preference to a person outside the family. PMID:12365764

  13. Activities of methionine-γ-lyase in the acidophilic archaeon “Ferroplasma acidarmanus” strain fer1

    Directory of Open Access Journals (Sweden)

    Khan MA

    2013-04-01

    Full Text Available M A Khan,1 Madeline M López-Muñoz,2 Charles W Kaspar,3 Kai F Hung1 1Department of Biological Sciences, Eastern Illinois University, Charleston, IL, USA; 2Department of Biology, Universidad de Puerto Rico, Mayaguez, Puerto Rico; 3Bacteriology Department, University of Wisconsin, Madison, WI, USA Abstract: Biogeochemical processes on exposed pyrite ores result in extremely high levels of sulfuric acid at these locations. Acidophiles that thrive in these conditions must overcome significant challenges, including an environment with proton concentrations at pH 3 or below. The role of sulfur metabolism in the archaeon “Ferroplasma acidarmanus” strain fer1's ability to thrive in this environment was investigated due to its growth-dependent production of methanethiol, a volatile organic sulfur compound. Two putative sequences for methionine-γ-lyase (EC 4.4.1.11, an enzyme known to carry out α, γ-elimination on L-methionine to produce methanethiol, were identified in fer1. Bioinformatic analyses identified a conserved pyridoxal-5'-phosphate (PLP binding domain and a partially conserved catalytic domain in both putative sequences. Detection of PLP-dependent and L-methionine-dependent production of α-keto compounds and thiol groups in fer1 confirmed the presence of methionine-γ-lyase activity. Further, fer1 lysate was capable of processing related substrates, including D-methionine, L-cysteine, L-cystathionine, and L/D-homocysteine. When the two putative fer1 methionine-γ-lyase gene-coded proteins were expressed in Escherichia coli cells, one sequence demonstrated an ability to carry out α, γ-elimination activity, while the other exhibited γ-replacement activity. These fer1 methionine-γ-lyases also exhibited optimum pH, substrate specificity, and catalytic preferences that are different from methionine-γ-lyases from other organisms. These differences are discussed in the context of molecular phylogeny constructed using a maximum

  14. Effects of methionine supplementation on the expression of oxidative stress-related genes in acute heat stress-exposed broilers.

    Science.gov (United States)

    Del Vesco, Ana Paula; Gasparino, Eliane; Grieser, Daiane de Oliveira; Zancanela, Vittor; Soares, Maria Amélia Menck; Neto, Adhemar Rodrigues de Oliveira

    2015-02-28

    The aim of the present study was to evaluate the effects of heat stress (HS) and methionine supplementation on the markers of stress and on the gene expression levels of uncoupling proteins (UCP), betaine-homocysteine methyltransferase (BHMT), cystathionine β-synthase (CBS), glutathione synthetase (GSS) and glutathione peroxidase 7 (GPx7). Broilers from 1 to 21 d and from 22 to 42 d of age were divided into three treatment groups related to methionine supplementation: without methionine supplementation (MD); recommended level of methionine supplementation (DL1); excess methionine supplementation (DL2). The broilers were either kept at a comfortable thermal temperature or exposed to HS (38°C for 24 h). During the starter period, we observed the effects of the interaction between diet and environment on the gene expression levels of UCP, BHMT and GSS. Higher gene expression levels of UCP and BHMT were observed in broilers that were maintained at thermal comfort conditions and received the MD diet. HS broilers fed the DL1 and DL2 diets had the highest expression level of GSS. The expression levels of the CBS and GPx7 genes were influenced by both the environment and methionine supplementation. During the grower period, the gene expression levels of BHMT, CBS, GSS and GPx7 were affected by the diet × environment interaction. A higher expression level of BHMT was observed in broilers maintained at thermal comfort conditions and on the MD diet. HS induced higher expression levels of CBS, GSS and GPx7 in broilers that received the DL1 and DL2 diets. The present results suggest that under HS conditions, methionine supplementation could mitigate the effects of stress, since methionine contributed to the increased expression levels of genes related to antioxidant activity.

  15. Heterologous production of methionine-γ-lyase from brevibacterium linens in lactococcus lactis and formation of volatile sulfur compounds

    OpenAIRE

    Hanniffy, Sean; Philo, Mark; Peláez, Carmen; Gasson, M. J.; Requena, Teresa; Martínez-Cuesta, M. Carmen

    2009-01-01

    The conversion of methionine to volatile sulfur compounds (VSCs) is of great importance in flavor formation during cheese ripening and is the focus of biotechnological approaches toward flavor improvement. A synthetic mgl gene encoding methionine-γ-lyase (MGL) from Brevibacterium linens BL2 was cloned into a Lactococcus lactis expression plasmid under the control of the nisin-inducible promoter PnisA. When expressed in L. lactis and purified as a recombinant protein, MGL was shown to degrade ...

  16. A Methionine Deficient Diet Enhances Adipose Tissue Lipid Metabolism and Alters Anti-Oxidant Pathways in Young Growing Pigs.

    Directory of Open Access Journals (Sweden)

    Rosa Castellano

    Full Text Available Methionine is a rate-limiting amino-acid for protein synthesis but non-proteinogenic roles on lipid metabolism and oxidative stress have been demonstrated. Contrary to rodents where a dietary methionine deficiency led to a lower adiposity, an increased lipid accretion rate has been reported in growing pigs fed a methionine deficient diet. This study aimed to clarify the effects of a dietary methionine deficiency on different aspects of tissue lipid metabolism and anti-oxidant pathways in young pigs. Post-weaned pigs (9.8 kg initial body weight were restrictively-fed diets providing either an adequate (CTRL or a deficient methionine supply (MD during 10 days (n=6 per group. At the end of the feeding trial, pigs fed the MD diet had higher lipid content in subcutaneous adipose tissue. Expression levels of genes involved in glucose uptake, lipogenesis but also lipolysis, and activities of NADPH enzyme suppliers were generally higher in subcutaneous and perirenal adipose tissues of MD pigs, suggesting an increased lipid turnover in those pigs. Activities of the anti-oxidant enzymes superoxide dismutase, catalase and glutathione reductase were increased in adipose tissues and muscle of MD pigs. Expression level and activity of the glutathione peroxidase were also higher in liver of MD pigs, but hepatic contents in the reduced and oxidized forms of glutathione and glutathione reductase activity were lower compared with control pigs. In plasma, superoxide dismutase activity was higher but total anti-oxidant power was lower in MD pigs. These results show that a dietary methionine deficiency resulted in increased levels of lipogenesis and lipolytic indicators in porcine adipose tissues. Decreased glutathione content in the liver and coordinated increase of enzymatic antioxidant activities in adipose tissues altered the cellular redox status of young pigs fed a methionine-deficient diet. These findings illustrate that a rapidly growing animal differently

  17. Serine Metabolism Supports the Methionine Cycle and DNA/RNA Methylation through De Novo ATP Synthesis in Cancer Cells

    OpenAIRE

    Maddocks, Oliver D. K.; Labuschagne, Christiaan F.; Adams, Peter D; Vousden, Karen H

    2016-01-01

    Summary: Crosstalk between cellular metabolism and the epigenome regulates epigenetic and metabolic homeostasis and normal cell behavior. Changes in cancer cell metabolism can directly impact epigenetic regulation and promote transformation. Here we analyzed the contribution of methionine and serine metabolism to methylation of DNA and RNA. Serine can contribute to this pathway by providing one-carbon units to regenerate methionine from homocysteine. While we observed this contribution under ...

  18. A Methionine Deficient Diet Enhances Adipose Tissue Lipid Metabolism and Alters Anti-Oxidant Pathways in Young Growing Pigs.

    Science.gov (United States)

    Castellano, Rosa; Perruchot, Marie-Hélène; Conde-Aguilera, José Alberto; van Milgen, Jaap; Collin, Anne; Tesseraud, Sophie; Mercier, Yves; Gondret, Florence

    2015-01-01

    Methionine is a rate-limiting amino-acid for protein synthesis but non-proteinogenic roles on lipid metabolism and oxidative stress have been demonstrated. Contrary to rodents where a dietary methionine deficiency led to a lower adiposity, an increased lipid accretion rate has been reported in growing pigs fed a methionine deficient diet. This study aimed to clarify the effects of a dietary methionine deficiency on different aspects of tissue lipid metabolism and anti-oxidant pathways in young pigs. Post-weaned pigs (9.8 kg initial body weight) were restrictively-fed diets providing either an adequate (CTRL) or a deficient methionine supply (MD) during 10 days (n=6 per group). At the end of the feeding trial, pigs fed the MD diet had higher lipid content in subcutaneous adipose tissue. Expression levels of genes involved in glucose uptake, lipogenesis but also lipolysis, and activities of NADPH enzyme suppliers were generally higher in subcutaneous and perirenal adipose tissues of MD pigs, suggesting an increased lipid turnover in those pigs. Activities of the anti-oxidant enzymes superoxide dismutase, catalase and glutathione reductase were increased in adipose tissues and muscle of MD pigs. Expression level and activity of the glutathione peroxidase were also higher in liver of MD pigs, but hepatic contents in the reduced and oxidized forms of glutathione and glutathione reductase activity were lower compared with control pigs. In plasma, superoxide dismutase activity was higher but total anti-oxidant power was lower in MD pigs. These results show that a dietary methionine deficiency resulted in increased levels of lipogenesis and lipolytic indicators in porcine adipose tissues. Decreased glutathione content in the liver and coordinated increase of enzymatic antioxidant activities in adipose tissues altered the cellular redox status of young pigs fed a methionine-deficient diet. These findings illustrate that a rapidly growing animal differently adapts tissue

  19. Anti-tumor effect of L-methionine-deprived total parenteral nutrition with 5-fluorouracil administration on Yoshida sarcoma-bearing rats.

    Science.gov (United States)

    Goseki, N; Endo, M; Onodera, T; Kosaki, G

    1991-07-01

    L-methionine-deprived total parenteral nutrition (methionine-deprived TPN), infusing amino acid solution devoid of L-methionine and L-cysteine by the method of TPN as an only protein source, showed enhancement of the effect of several anti-cancer agents. In this study the combined effect of the methionine-deprived TPN with administration of 5-fluorouracil (5-FU) was examined in Yoshida Sarcoma (YS)-bearing rats, from aspects of effects on the tumor metastasis and the host animal's life span, in the following four groups treated with: methionine-deprived TPN with administration of 5-FU, methionine-deprived TPN without administration of 5-FU, L-methionine-contained TPN plus 5-FU, and L-methionine-contained TPN without 5-FU. In the first experiment, TPN was continued for 8 days in the four groups, and the anti-cancer effect of methionine-deprived TPN and administration of 5-FU based on both the growth of the primary tumor at the implanted site and the tumor metastasis was studied from the view point of pathologic findings of animals killed immediately after these treatments. In experiment 2 the survival period was examined after these treatments for 10 days with subsequent oral feeding until death. The results were as follows: proliferation of YS, transplanted subcutaneously, was markedly suppressed; particularly hematogenous metastasis, characteristic in YS, was prominently blunted then obtained an apparent longer survival period in rats treated with the methionine-deprived TPN with administration of 5-FU.

  20. Clinical Applications of FDG PET and PET/CT in Head and Neck Cancer

    Directory of Open Access Journals (Sweden)

    Akram Al-Ibraheem

    2009-01-01

    Full Text Available 18F-FDG PET plays an increasing role in diagnosis and management planning of head and neck cancer. Hybrid PET/CT has promoted the field of molecular imaging in head and neck cancer. This modality is particular relevant in the head and neck region, given the complex anatomy and variable physiologic FDG uptake patterns. The vast majority of 18F-FDG PET and PET/CT applications in head and neck cancer related to head and neck squamous cell carcinoma. Clinical applications of 18F-FDG PET and PET/CT in head and neck cancer include diagnosis of distant metastases, identification of synchronous 2nd primaries, detection of carcinoma of unknown primary and detection of residual or recurrent disease. Emerging applications are precise delineation of the tumor volume for radiation treatment planning, monitoring treatment, and providing prognostic information. The clinical role of 18F-FDG PET/CT in N0 disease is limited which is in line with findings of other imaging modalities. MRI is usually used for T staging with an intense discussion concerning the preferable imaging modality for regional lymph node staging as PET/CT, MRI, and multi-slice spiral CT are all improving rapidly. Is this review, we summarize recent literature on 18F-FDG PET and PET/CT imaging of head and neck cancer.