A pivotal role for starch in the reconfiguration of 14C-partitioning and allocation in Arabidopsis thaliana under short-term abiotic stress.

Plant carbon status is optimized for normal growth but is affected by abiotic stress. Here, we used 14C-labeling to provide the first holistic picture of carbon use changes during short-term osmotic, salinity, and cold stress in Arabidopsis thaliana. This could inform on the early mechanisms plants use to survive adverse environment, which is important for efficient agricultural production. We found that carbon allocation from source to sinks, and partitioning into major metabolite pools in the source leaf, sink leaves and roots showed both conserved and divergent responses to the stresses examined. Carbohydrates changed under all abiotic stresses applied; plants re-partitioned 14C to maintain sugar levels under stress, primarily by reducing 14C into the storage compounds in the source leaf, and decreasing 14C into the pools used for growth processes in the roots. Salinity and cold increased 14C-flux into protein, but as the stress progressed, protein degradation increased to produce amino acids, presumably for osmoprotection. Our work also emphasized that stress regulated the carbon channeled into starch, and its metabolic turnover. These stress-induced changes in starch metabolism and sugar export in the source were partly accompanied by transcriptional alteration in the T6P/SnRK1 regulatory pathway that are normally activated by carbon starvation

A922 Sequential measurement of 1 hour creatinine clearance (1-CRCL) in critically ill patients at risk of acute kidney injury (AKI)

Meeting abstrac

Manual and semi-automatic quantification of in vivo H-1-MRS data for the classification of human primary brain tumors

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)In vivo proton magnetic resonance spectroscopy (H-1-MRS) is a technique capable of assessing biochemical content and pathways in normal and pathological tissue. In the brain, H-1-MRS complements the information given by magnetic resonance images. The main goal of the present study was to assess the accuracy of H-1-MRS for the classification of brain tumors in a pilot study comparing results obtained by manual and semi-automatic quantification of metabolites. In vivo single-voxel H-1-MRS was performed in 24 control subjects and 26 patients with brain neoplasms that included meningiomas, high-grade neuroglial tumors and pilocytic astrocytomas. Seven metabolite groups (lactate, lipids, N-acetyl-aspartate, glutamate and glutamine group, total creatine, total choline, myo-inositol) were evaluated in all spectra by two methods: a manual one consisting of integration of manually defined peak areas, and the advanced method for accurate, robust and efficient spectral fitting (AMARES), a semi-automatic quantification method implemented in the jMRUI software. Statistical methods included discriminant analysis and the leave-one-out cross-validation method. Both manual and semi-automatic analyses detected differences in metabolite content between tumor groups and controls (P < 0.005). The classification accuracy obtained with the manual method was 75% for high-grade neuroglial tumors, 55% for meningiomas and 56% for pilocytic astrocytomas, while for the semi-automatic method it was 78, 70, and 98%, respectively. Both methods classified all control subjects correctly. The study demonstrated that H-1-MRS accurately differentiated normal from tumoral brain tissue and confirmed the superiority of the semi-automatic quantification method.444345353Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq

Multivoxel 1H MR spectroscopy biometrics for preoprerative differentiation between brain tumors

Purpose To investigate multivoxel proton Magnetic Resonance Spectroscopy (1HMRS) biometrics for preoperative differentiation and prognosis of patients with brain metastases (MET), low-(LGG) and high grade glioma (HGG). Methods Thirty-five patients (15 HGG, 9 LGG and 11 MET) were included. Proton Magnetic Resonance Spectroscopy Imaging(1H-MRSI) data was assessed and neurochemical profiles for metabolites (NAA+NAAG, Cr+PCr, Glu+Gln (Glx), Lac, Ins, GPC+PCho) and total Lipids (tLip) and macromolecule (tMM) signals were estimated. Concentrations were reported as either absolute or ratios to total choline (tCho=GPC+PCho) and creatine (tCr=Cr+PCr) levels. Voxels of interest (VOIs) in a MRSI matrix were labelled accordingly to contrast-enhancing/nonenhancing lesional, edema, ipsi- or contralateral healthy appearing tissue and the metabolite averages were reported for each tissue type. Multi-biometric analysis with logistic regression, ROC- and Kaplan-Meier survival analysis was performed in SPSS v.24 and postprocessing with LC Model. Results Across HGG/LGG/MET; the average Ins/tCho was shown to be prognostic for overall survival (OS): with low values (≤1.29) in affected hemisphere predicting worse OS than high values (>1.29), (Log Ran

Comparative metabolic profiling of paediatric ependymoma, medulloblastoma and pilocytic astrocytoma

Brain tumours are the most common solid tumours in children and a major cause of childhood mortality. The most common paediatric brain tumours include ependymomas, cerebellar astrocytomas and medulloblastomas. These brain tumours are highly heterogeneous regarding their histology, prognosis and therapeutic response. Subtle biochemical changes can be detected in intact tissues by High-Resolution Proton Magnetic Angle Spinning Spectroscopy (HR-MAS) revealing the status of tumour microheterogeneity and metabolic alterations before they are morphologically detectable. In this study, we present metabolic profiles by HR-MAS of 20 intact tissue samples from paediatric brain tumours. Tumour types include ependymoma, medulloblastoma and pilocytic astrocytoma. The metabolic characterization of paediatric brain tumour tissue by HR-MAS spectroscopy provided differential patterns for these tumours. The metabolic composition of the tumour tissue was highly consistent with previous in vivo and ex vivo studies. Some resonances detected in this work and not previously observed by in vivo spectroscopy also show potential in determining tumour type and grade (fatty acids, phenylalanine, glutamate). Overall, this work suggests that the additional information obtained by NMR metabolic profiling applied to tissue from paediatric brain tumours may be useful for assessing tumour grade and determining optimum treatment strategies.O TEXTO COMPLETO DESTE ARTIGO, ESTARÁ DISPONÍVEL À PARTIR DE FEVEREIRO DE 2015.266941948Ministry of Science and Innovation of Spain [SAF 2008-00270, SAF2007-65473]Conselleria de Educacion of the Generalitat Valenciana [ACOMP/2009/200]Conselleria de Sanidad of the Generalitat Valenciana [AP076/08]Ministry of Education of SpainEuropean Comission [FP6-2002-LIFESCIHEALTH 503094]Banco Santander-BANESPAMinistry of Science and Innovation of Spain [SAF 2008-00270, SAF2007-65473]Conselleria de Educacion of the Generalitat Valenciana [ACOMP/2009/200]Conselleria de Sanidad of the Generalitat Valenciana [AP076/08]European Comission [FP6-2002-LIFESCIHEALTH 503094

Comparative Metabolic Profiling Of Paediatric Ependymoma, Medulloblastoma And Pilocytic Astrocytoma.

Brain tumours are the most common solid tumours in children and a major cause of childhood mortality. The most common paediatric brain tumours include ependymomas, cerebellar astrocytomas and medulloblastomas. These brain tumours are highly heterogeneous regarding their histology, prognosis and therapeutic response. Subtle biochemical changes can be detected in intact tissues by High-Resolution Proton Magnetic Angle Spinning Spectroscopy (HR-MAS) revealing the status of tumour microheterogeneity and metabolic alterations before they are morphologically detectable. In this study, we present metabolic profiles by HR-MAS of 20 intact tissue samples from paediatric brain tumours. Tumour types include ependymoma, medulloblastoma and pilocytic astrocytoma. The metabolic characterization of paediatric brain tumour tissue by HR-MAS spectroscopy provided differential patterns for these tumours. The metabolic composition of the tumour tissue was highly consistent with previous in vivo and ex vivo studies. Some resonances detected in this work and not previously observed by in vivo spectroscopy also show potential in determining tumour type and grade (fatty acids, phenylalanine, glutamate). Overall, this work suggests that the additional information obtained by NMR metabolic profiling applied to tissue from paediatric brain tumours may be useful for assessing tumour grade and determining optimum treatment strategies.26941-