Metabolic Information (metabolic + information)

Distribution by Scientific Domains

Selected Abstracts

Characterization of 1H NMR detectable mobile lipids in cells from human adenocarcinomas

FEBS JOURNAL, Issue 5 2009
Anna Maria Luciani
Magnetic resonance spectroscopy studies are often carried out to provide metabolic information on tumour cell metabolism, aiming for increased knowledge for use in anti-cancer treatments. Accordingly, the presence of intense lipid signals in tumour cells has been the subject of many studies aiming to obtain further insight on the reaction of cancer cells to external agents that eventually cause cell death. The present study explored the relationship between changes in neutral lipid signals during cell growth and after irradiation with gamma rays to provide arrest in cell cycle and cell death. Two cell lines from human tumours were used that were differently prone to apoptosis following irradiation. A sub-G1 peak was present only in the radiosensitive HeLa cells. Different patterns of neutral lipids changes were observed in spectra from intact cells, either during unperturbed cell growth in culture or after radiation-induced growth arrest. The intensities of triglyceride signals in the spectra from extracted total lipids changed concurrently. The increase in lipid peak intensities did not correlate with the apoptotic fate. Modelling to fit the experimental data revealed a dynamic equilibrium between the production and depletion of neutral lipids. This is observed for the first time in cells that are different from adipocytes. [source]

FDG PET studies during treatment: Prediction of therapy outcome in head and neck squamous cell carcinoma

Eva Brun MD
Background Positron emission tomography (PET) provides metabolic information of tissues in vivo. The purpose of this study was to assess the value of PET with 2-[18 F] fluoro-2-deoxy- D -glucose (FDG) in prediction of therapy outcome (tumor response, survival, and locoregional control) in locally advanced HNSCC. Methods Between 1993 and 1999 47 patients underwent PET before (PET1) and after (PET2) 1 to 3 weeks of radical treatment with evaluation of metabolic rate (MR) and standardized uptake value (SUV) of FDG. All patients received radiotherapy, and 10 also received neoadjuvant chemotherapy. Median follow-up time was 3.3 years. Results Low and high MR FDG at PET2, with median value as cutoff, was associated with complete remission in 96% and 62% (p = .007), with 5-year overall survival in 72% and 35% (p = .0042) and with local control in 96% and 55% (p = .002), respectively. Conclusions FDG PET in the early phase of treatment of HNSCC is associated with tumor response, survival, and local control. 2002 John Wiley & Sons, Inc. [source]

Fast 3D 1H MRSI of the corticospinal tract in pediatric brain

Dong-Hyun Kim PhD
Abstract Purpose To develop a 1H magnetic resonance spectroscopic imaging (MRSI) sequence that can be used to image infants/children at 3T and by combining it with diffusion tensor imaging (DTI) tractography, extract relevant metabolic information corresponding to the corticospinal tract (CST). Materials and Methods A fast 3D MRSI sequence was developed for pediatric neuroimaging at 3T using spiral k-space readout and dual band RF pulses (32 32 8 cm field of view [FOV], 1 cc iso-resolution, TR/TE = 1500/130, 6:24 minute scan). Using DTI tractography to identify the motor tracts, spectra were extracted from the CSTs and quantified. Initial data from infants/children with suspected motor delay (n = 5) and age-matched controls (n = 3) were collected and N -acetylaspartate (NAA) ratios were quantified. Results The average signal-to-noise ratio of the NAA peak from the studies was ,22. Metabolite profiles were successfully acquired from the CST by using DTI tractography. Decreased NAA ratios in those with motor delay compared to controls of ,10% at the CST were observed. Conclusion A fast and robust 3D MRSI technique targeted for pediatric neuroimaging has been developed. By combining with DTI tractography, metabolic information from the CSTs can be retrieved and estimated. By combining DTI and 3D MRSI, spectral information from various tracts can be obtained and processed. J. Magn. Reson. Imaging 2009;29:1,6. 2008 Wiley-Liss, Inc. [source]

Multiple spin-echo spectroscopic imaging for rapid quantitative assessment of N-acetylaspartate and lactate in acute stroke

Astrid Stengel
Abstract Monitoring the signal levels of lactate (Lac) and N-acetylaspartate (NAA) by chemical shift imaging can provide additional knowledge about tissue damage in acute stroke. Despite the need for this metabolic information, spectroscopic imaging (SI) has not been used routinely for acute stroke patients, mainly due to the long acquisition time required. The presented data demonstrate that the application of a fast multiple spin-echo (MSE) SI sequence can reduce the measurement time to 6 min (four spin echoes per echo train, 32 32 matrix). Quantification of Lac and NAA in terms of absolute concentrations (i.e., mmol/l) can be achieved by means of the phantom replacement approach, with correction terms for the longitudinal and transversal relaxation adapted to the multiple spin-echo sequence. In this pilot study of 10 stroke patients (symptom onset < 24 hr), metabolite concentrations obtained from MSE-SI add important information regarding tissue viability that is not provided by other sequences (e.g., diffusion-weighted imaging (DWI) and perfusion-weighted imaging (PWI)). Metabolic changes extended beyond the borders of the apparent diffusion coefficient (ADC) lesion in nine of the 10 patients, showing a rise in Lac concentrations up to 18 mmol/l, while NAA levels sometimes dropped below the detection level. Considerable differences among the patients in terms of the Lac concentrations and the size of the SI-ADC mismatch were observed. Magn Reson Med 52:228,238, 2004. 2004 Wiley-Liss, Inc. [source]

Carbonate extraction process for the metabolic, isozymic and proteomic profiling of rose-scented geranium (Pelargonium sp.), a hyper-acidic plant

Rajender Singh Sangwan
Abstract Rose-scented geranium (Pelargonium sp.) is a valuable monoterpene-yielding plant. It has been well characterised phytochemically through the isolation of >270 secondary metabolites, however, there is hardly any biochemical or metabolic information concerning this plant. Initial attempts to investigate its metabolism failed to produce any enzyme activity in the tissue extracts prepared in routine extraction buffers owing to the intrinsic properties of the tissue matrix. It was recognised that cellular hyper-acidity (cell sap pH ,3.0) gave rise to very low protein levels in the extracts, thus prohibiting detection of activities of even primary metabolic enzymes that are usually abundantly present in plants. Tissue extraction in Tris solution without pH adjustment (as used for studies involving citrus and banana) led to little or no improvement. Therefore, a novel approach using sodium carbonate solution as an efficient extraction system for enzymes and proteins from the plant was studied. Functionality of the carbonate extraction has been demonstrated through its effectiveness, a several-fold superior performance, in yielding protein, monitoring primary metabolism and secondary metabolic enzymes, and isozymic and polypeptide profiling. The process may also be helpful in the reliable analysis of other acidic plant tissues. Copyright 2007 John Wiley & Sons, Ltd. [source]