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https://www.readbyqxmd.com/read/28204572/o-2-18f-fluoroethyl-l-tyrosine-pet-for-evaluation-of-brain-metastasis-recurrence-after-radiotherapy-an-effectiveness-and-cost-effectiveness-analysis
#1
Alexander Heinzel, Dirk Müller, Sareh Said Yekta-Michael, Garry Ceccon, Karl-Josef Langen, Felix M Mottaghy, Martin Wiesmann, Martin Kocher, Elke Hattingen, Norbert Galldiks
No abstract text is available yet for this article.
February 13, 2017: Neuro-oncology
https://www.readbyqxmd.com/read/28202018/de-novo-biosynthesis-of-pterostilbene-in-an-escherichia-coli-strain-using-a-new-resveratrol-o-methyltransferase-from-arabidopsis
#2
Kyung Taek Heo, Sun-Young Kang, Young-Soo Hong
BACKGROUND: Pterostilbene, a structural analog of resveratrol, has higher oral bioavailability and bioactivity than that of the parent compound; but is far less abundant in natural sources. Thus, to efficiently obtain this bioactive resveratrol analog, it is necessary to develop new bioproduction systems. RESULTS: We identified a resveratrol O-methyltransferase (ROMT) function from a multifunctional caffeic acid O-methyltransferase (COMT) originating from Arabidopsis, which catalyzes the transfer of a methyl group to resveratrol resulting in pterostilbene production...
February 15, 2017: Microbial Cell Factories
https://www.readbyqxmd.com/read/28192140/action-of-2-2-4-4-tetrahydroxybenzophenone-in-the-biosynthesis-pathway-of-melanin
#3
Antonio Garcia-Jimenez, Jose Antonio Teruel-Puche, Pedro Antonio Garcia-Ruiz, Jose Berna, Jose Neptuno Rodríguez-López, Jose Tudela, Francisco Garcia-Canovas
2,2',4,4'-tetrahydroxybenzophenone (Uvinul D50), a sunscreen used in cosmetics, has two effects in the melanin biosynthesis pathway. On the one hand, it acts a weak inhibitor of tyrosinase and on the other, it accelerates the conversion of dopachrome to melanin. Uvinul D50 was seen to behave as a weak competitive inhibitor: apparent constant inhibition=2.02±0.09mM and IC50=3.82±0.39mM established in this work. These values are higher than those in the bibliography, which tend to be undersetimated. This discrepancy could be explained by the reaction of Uvinul D50 with the dopachrome produced from l-tyrosine or l-dopa, which would interfere in the measurement...
February 10, 2017: International Journal of Biological Macromolecules
https://www.readbyqxmd.com/read/28187333/localization-of-cl-35-nuclei-in-biological-solids-using-rotational-echo-double-resonance-experiments
#4
D Iuga, P Rossi, J Herzfeld, R G Griffin
Chloride ions play important roles in many chemical and biological processes. This paper investigates the possibility of localizing (35)Cl nuclei using solid-state NMR. It demonstrates that distances shorter than 3.8Å, between (13)C atoms and (35)Cl atoms in 10% uniformly labeled (13)C L-tyrosine·HCl and natural abundance Glycine·HCl can be measured using rotational-echo (adiabatic passage) double-resonance (RE(AP)DOR). Furthermore the effect of quadrupolar interaction on the REDOR/REAPDOR experiment is quantified...
January 30, 2017: Solid State Nuclear Magnetic Resonance
https://www.readbyqxmd.com/read/28153956/influence-of-bevacizumab-on-blood-brain-barrier-permeability-and-o-2-18f-fluoroethyl-l-tyrosine-uptake-in-rat-gliomas
#5
Carina Stegmayr, Dennis Oliveira, Nicole Niemietz, Antje Willuweit, Philipp Lohmann, Norbert Galldiks, N Jon Shah, Johannes Ermert, Karl-Josef Langen
PURPOSE: Restoration of the blood-brain barrier (BBB) following antiangiogenic therapy of gliomas using Bevacizumab may result in a decrease of contrast enhancement in magnet resonance imaging (MRI) despite tumor progression. This so called pseudoresponse is difficult to differentiate from true tumor response with conventional MRI. First patient studies have indicated that positron emission tomography (PET) using O-(2-(18)F-fluoroethyl)-L-tyrosine ((18)F-FET) may be helpful to solve this diagnostic problem...
February 2, 2017: Journal of Nuclear Medicine: Official Publication, Society of Nuclear Medicine
https://www.readbyqxmd.com/read/28150904/rationally-developed-organic-salts-of-tolfenamic-acid-and-its-%C3%AE-alanine-derivatives-for-dual-purpose-anti-inflammatory-topical-gel-and-anti-cancer-agent
#6
Parthasarathi Dastidar, Rumana Parveen, Bommagani Sravanthi
A new series of primary ammonium monocarboxylate (PAM) salts of a non-steroidal-anti-Inflammatory-drug (NSAID) namely Tolfenamic acid (TA) and its β-alanine derivative was generated; nearly 67% of the salts in the series showed gelling ability with various solvents including water (biogenic solvent) and methyl salicylate (typically used for topical gel formulations). Gels were characterized by table top and dynamic rheology, electron microscopy etc. Structure-property correlation based on single crystal and powder X-ray diffraction data of several gelator and non-gelator salts revealed intriguing insights...
February 2, 2017: Chemistry, An Asian Journal
https://www.readbyqxmd.com/read/28121442/investigation-of-fibril-forming-mechanisms-of-l-phenylalanine-and-l-tyrosine-microscopic-insight-toward-phenylketonuria-and-tyrosinemia-type-ii
#7
Debasis Banik, Sangita Kundu, Pavel Banerjee, Rupam Dutta, Nilmoni Sarkar
Phenylketonuria and tyrosinemia type II, the two metabolic disorders, are originated due to the complications in metabolism of phenylalanine (Phe) and tyrosine (Tyr), respectively. Several neurological injuries, involving microcephaly, mental retardation, epilepsy, motor disease, and skin problems etc., are the symptoms of these two diseases. It has been reported that toxic amyloid fibrils are formed at high concentrations of Phe and Tyr. Our study indicates that the fibril forming mechanisms of Phe and Tyr are completely different...
February 8, 2017: Journal of Physical Chemistry. B
https://www.readbyqxmd.com/read/28116231/the-use-of-amino-acid-pet-and-conventional-mri-for-monitoring-of-brain-tumor-therapy
#8
REVIEW
Norbert Galldiks, Ian Law, Whitney B Pope, Javier Arbizu, Karl-Josef Langen
Routine diagnostics and treatment monitoring of brain tumors is usually based on contrast-enhanced MRI. However, the capacity of conventional MRI to differentiate tumor tissue from posttherapeutic effects following neurosurgical resection, chemoradiation, alkylating chemotherapy, radiosurgery, and/or immunotherapy may be limited. Metabolic imaging using PET can provide relevant additional information on tumor metabolism, which allows for more accurate diagnostics especially in clinically equivocal situations...
2017: NeuroImage: Clinical
https://www.readbyqxmd.com/read/28110959/patterns-of-failure-for-patients-with-glioblastoma-following-o-2-18-f-fluoroethyl-l-tyrosine-pet-and-mri-guided-radiotherapy
#9
Michael Lundemann, Junia Cardoso Costa, Ian Law, Svend Aage Engelholm, Aida Muhic, Hans Skovgaard Poulsen, Per Munck Af Rosenschold
BACKGROUND AND PURPOSE: To evaluate the patterns of failure following clinical introduction of amino-acid O-(2-[(18)F]fluoroethyl)-L-tyrosine (FET)-PET-guided target definition for radiotherapy (RT) of glioblastoma patients. MATERIALS AND METHODS: The first 66 consecutive patients with confirmed histology, scanned using FET-PET/CT and MRI were selected for evaluation. Chemo-radiotherapy was delivered to a volume based on both MRI and FET-PET (PETvol). The volume of recurrence (RV) was defined on MRI data collected at the time of progression according to RANO criteria...
January 19, 2017: Radiotherapy and Oncology: Journal of the European Society for Therapeutic Radiology and Oncology
https://www.readbyqxmd.com/read/28105177/-18-f-fluoroethyl-l-tyrosine-positron-emission-tomography-guided-diagnosis-of-a-malignant-intramedullary-spinal-cord-tumor
#10
Sied Kebir, Okka Kimmich, Pitt Niehusmann, Florian C Gaertner, Markus Essler, Jennifer Landsberg, Thomas Klockgether, Matthias Simon, Ulrich Herrlinger, Martin Glas
Diagnosis in patients with a suspected malignant intramedullary lesion that requires biopsy for definitive diagnosis may be challenging, as spinal cord surgery carries the risk of irreversible neurological deficits. The current study presents the first case of (18)F-fluoroethyl-L-tyrosine ((18)F-FET) positron emission tomography (PET) imaging in a patient with a spinal cord tumor. The patient was unsuitable for magnetic resonance imaging due to his implanted cardiac defibrillator. (18)F-FET PET indicated a high-grade malignancy of the spinal cord, justifying tumor biopsy...
December 2016: Oncology Letters
https://www.readbyqxmd.com/read/28102943/comparison-of-five-cluster-validity-indices-performance-in-brain-18-f-fet-pet-image-segmentation-using-k-means
#11
Bedor Abualhaj, Guoyang Weng, Melissa Ong, Ali Asgar Attarwala, Flavia Molina, Karen Büsing, Gerhard Glatting
PURPOSE: Dynamic [(18) F]fluoro-ethyl-L-tyrosine positron emission tomography ([(18) F]FET-PET) is used to identify tumor lesions for radiotherapy treatment planning, to differentiate glioma recurrence from radiation necrosis and to classify gliomas grading. To segment different regions in the brain k-means cluster analysis can be used. The main disadvantage of k-means is that the number of clusters must be pre-defined. In this study, we therefore compared different cluster validity indices for automated and reproducible determination of the optimal number of clusters based on the dynamic PET data...
January 2017: Medical Physics
https://www.readbyqxmd.com/read/28102485/-18-f-fet-pet-prior-to-recurrent-high-grade-glioma-re-irradiation-additional-prognostic-value-of-dynamic-time-to-peak-analysis-and-early-static-summation-images
#12
Daniel F Fleischmann, Marcus Unterrainer, Peter Bartenstein, Claus Belka, Nathalie L Albert, Maximilian Niyazi
Most high-grade gliomas (HGG) recur after initial multimodal therapy and re-irradiation (Re-RT) has been shown to be a valuable re-treatment option in selected patients. We evaluated the prognostic value of dynamic time-to-peak analysis and early static summation images in O-(2-(18)F-fluoroethyl)-l-tyrosine ((18)F-FET) PET for patients treated with Re-RT ± concomitant bevacizumab. We retrospectively analyzed 72 patients suffering from recurrent HGG with (18)F-FET PET prior to Re-RT. PET analysis revealed the maximal tumor-to-background-ratio (TBRmax), the biological tumor volume, the number of PET-foci and pattern of time-activity-curves (TACs; increasing vs...
January 19, 2017: Journal of Neuro-oncology
https://www.readbyqxmd.com/read/28096758/effects-of-acute-ingestion-of-a-pre-workout-dietary-supplement-with-and-without-p-synephrine-on-resting-energy-expenditure-cognitive-function-and-exercise-performance
#13
Y Peter Jung, Conrad P Earnest, Majid Koozehchian, Elfego Galvan, Ryan Dalton, Dillon Walker, Christopher Rasmussen, Peter S Murano, Mike Greenwood, Richard B Kreider
BACKGROUND: The purpose of this study was to examine the effects of acute ingestion of a pre-workout dietary supplement (PWS) with and without p-synephrine (S) on perceptions of readiness to perform, cognitive function, exercise performance, and markers of safety. METHODS: In a randomized, double-blind, and counterbalanced manner; 25 healthy and recreationally active male and female participants ingested a flavored maltodextrin placebo (PLA), a PWS containing beta-alanine (3 g), creatine nitrate as a salt (2 g), arginine alpha-ketoglutarate (2 g), N-Acetyl-L-Tyrosine (300 mg), caffeine (284 mg), Mucuna pruiriens extract standardized for 15% L-Dopa (15 mg), Vitamin C as Ascorbic Acid (500 mg), niacin (60 mg), folate as folic acid (50 mg), and Vitamin B12 as Methylcobalamin (70 mg) with 2 g of maltodextrin and flavoring; or, the PWS with Citrus aurantium (PWS + S) extract standardized for 30% p-synephrine (20 mg)...
2017: Journal of the International Society of Sports Nutrition
https://www.readbyqxmd.com/read/28096757/effects-of-ingesting-a-pre-workout-dietary-supplement-with-and-without-synephrine-for-8%C3%A2-weeks-on-training-adaptations-in-resistance-trained-males
#14
Y Peter Jung, Conrad P Earnest, Majid Koozehchian, Minye Cho, Nick Barringer, Dillon Walker, Christopher Rasmussen, Mike Greenwood, Peter S Murano, Richard B Kreider
BACKGROUND: The purpose of this study was to examine whether ingesting a pre-workout dietary supplement (PWS) with and without synephrine (S) during training affects training responses in resistance-trained males. METHODS: Resistance-trained males (N = 80) were randomly assigned to supplement their diet in a double-blind manner with either a flavored placebo (PLA); a PWS containing beta-alanine (3 g), creatine nitrate as a salt (2 g), arginine alpha-ketoglutarate (2 g), N-Acetyl-L-Tyrosine (300 mg), caffeine (284 mg), Mucuna pruiriens extract standardized for 15% L-Dopa (15 mg), Vitamin C as Ascorbic Acid (500 mg), niacin (60 mg), folate as folic acid (50 mg), and Vitamin B12 as Methylcobalamin (70 mg); or, the PWS supplement with Citrus aurantium extract containing 20 mg of synephrine (PWS + S) once per day for 8-weeks during training...
2017: Journal of the International Society of Sports Nutrition
https://www.readbyqxmd.com/read/28077650/melanin-or-melanin-like-substance-interacts-with-the-n-terminal-portion-of-prion-protein-and-inhibits-abnormal-prion-protein-formation-in-prion-infected-cells
#15
Taichi Hamanaka, Keiko Nishizawa, Yuji Sakasegawa, Ayumi Oguma, Kenta Teruya, Hiroshi Kurahashi, Hideyuki Hara, Suehiro Sakaguchi, Katsumi Doh-Ura
Prion diseases are progressive fatal neurodegenerative illnesses caused by the accumulation of transmissible abnormal prion protein (PrP). To find treatments for prion diseases, we searched for substances from natural resources that inhibit abnormal PrP formation in prion-infected cells. We found that high-molecular-weight components from insect cuticle extracts reduced abnormal PrP levels. The chemical nature of these components was consistent with that of melanin. In fact, synthetic melanin produced from tyrosine or 3-hydroxy-l-tyrosine inhibited abnormal PrP formation...
January 11, 2017: Journal of Virology
https://www.readbyqxmd.com/read/28064504/development-of-l-tyrosine-based-enzyme-responsive-amphiphilic-poly-ester-urethane-nanocarriers-for-multiple-drug-delivery-to-cancer-cells
#16
Rajendra Aluri, Manickam Jayakannan
New classes of enzymatic-biodegradable amphiphilic poly(ester-urethane)s were designed and developed from l-tyrosine amino acid resources and their self-assembled nanoparticles were employed as multiple drug delivery vehicles in cancer therapy. The amine and carboxylic acid functional groups in l-tyrosine were converted into dual functional ester-urethane monomers and they were subjected to solvent free melt polycondensation with hydrophilic polyethylene glycols to produce comb-type poly(ester-urethane)s. The phenolic unit in the l-tyrosine was anchored with hydrophobic alkyl side chain to bring appropriate amphiphilicity in the polymer geometry to self-assemble them as stable nanoscaffolds in aqueous medium...
January 9, 2017: Biomacromolecules
https://www.readbyqxmd.com/read/28045730/neurosarcoidosis-on-fet-and-fdg-pet-ct
#17
Mico Chan, Edward Hsiao
O-(2-fluoroethyl)-L-tyrosine (FET) PET/CT is a promising imaging modality for brain tumor imaging because of its reported high sensitivity for biologically active tumor tissue. We present a case of biopsy-proven neurosarcoidosis showing FET uptake. It is an important cause of false-positive uptake on FET PET/CT.
March 2017: Clinical Nuclear Medicine
https://www.readbyqxmd.com/read/28039366/the-use-of-o-2-18f-fluoroethyl-l-tyrosine-pet-in-the-diagnosis-of-gliomas-located-in-the-brainstem-and-spinal-cord
#18
Caroline Tscherpel, Veronika Dunkl, Garry Ceccon, Gabriele Stoffels, Natalie Judov, Marion Rapp, Philipp T Meyer, Elena Rota Kops, Johannes Ermert, Gereon R Fink, Nadim J Shah, Karl-Josef Langen, Norbert Galldiks
BACKGROUND: Despite an increasing number of O-(2-(18)F-fluoroethyl)-L-tyrosine ((18)F-FET) PET studies in supratentorial gliomas, studies regarding the usefulness of (18)F-FET PET in brainstem and spinal cord gliomas to date remain scarce. METHODS: Thirty-six (18)F-FET PET scans were performed in 29 patients with brainstem (n = 29 scans) or spinal cord glioma (n = 7 scans). In 32 of 36 PET scans, a dynamic acquisition was performed. Fifteen scans in 15 patients were performed to assess newly diagnosed lesions, and 21 scans were obtained during follow-up: for diagnosing tumor progression (n = 15 scans in 14 patients) as well as for treatment monitoring (n = 6 scans in 3 patients)...
December 29, 2016: Neuro-oncology
https://www.readbyqxmd.com/read/28030820/unsupervised-consensus-cluster-analysis-of-18f-fluoroethyl-l-tyrosine-positron-emission-tomography-identified-textural-features-for-the-diagnosis-of-pseudoprogression-in-high-grade-glioma
#19
Sied Kebir, Zain Khurshid, Florian C Gaertner, Markus Essler, Elke Hattingen, Rolf Fimmers, Björn Scheffler, Ulrich Herrlinger, Ralph A Bundschuh, Martin Glas
RATIONALE: Timely detection of pseudoprogression (PSP) is crucial for the management of patients with high-grade glioma (HGG) but remains difficult. Textural features of O-(2-[18F]fluoroethyl)-L-tyrosine positron emission tomography (FET-PET) mirror tumor uptake heterogeneity; some of them may be associated with tumor progression. METHODS: Fourteen patients with HGG and suspected of PSP underwent FET-PET imaging. A set of 19 conventional and textural FET-PET features were evaluated and subjected to unsupervised consensus clustering...
January 31, 2017: Oncotarget
https://www.readbyqxmd.com/read/28028844/improved-tlc-bioautographic-assay-for-qualitative-and-quantitative-estimation-of-tyrosinase-inhibitors-in-natural-products
#20
Jinge Zhou, Qingjiu Tang, Tao Wu, Zhihong Cheng
INTRODUCTION: TLC bioautography for tyrosinase inhibitors has made recent progress; however, an assay with a relative low consumption of enzyme and quantitative capability would greatly advance the efficacy of related TLC bioautographic assays. OBJECTIVE: An improved TLC bioautographic assay for detecting tyrosinase inhibitors was developed and validated in this study. METHODS: L-DOPA (better water-solubility than L-tyrosine) was used as the substrate instead of reported L-tyrosine...
December 28, 2016: Phytochemical Analysis: PCA
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