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For more than half a century it has been generally believed that cancer cells are more acidic than normal cells. This dogma arose from the studies of Warburg and co-workers (Warburg, 1930) who showed that tumour cells preferentially convert glucose and other substrates to lactic acid, even under aerobic conditions. Since lactic acid has a pK of 3.7 it(More)
Proton spectroscopy can noninvasively provide useful information on brain tumor type and grade. Short- (30 ms) and long- (136 ms) echo time (TE) (1)H spectra were acquired from normal white matter (NWM), meningiomas, grade II astrocytomas, anaplastic astrocytomas, glioblastomas, and metastases. Very low myo-Inositol ([mI]) and creatine ([Cr]) were(More)
Cell growth (accumulation of mass) needs to be coordinated with metabolic processes that are required for the synthesis of macromolecules. The PI3-kinase/Akt signaling pathway induces cell growth via activation of complex 1 of the target of rapamycin (TORC1). Here we show that Akt-dependent lipogenesis requires mTORC1 activity. Furthermore, nuclear(More)
The purpose of this study was to examine the effect of aging on brain metabolite concentrations, including N-acetyl aspartate (NAA), the major marker of neurones, using short echo proton spectroscopy. Single-voxel proton spectra (TE 30 msec, TR 2 seconds) were obtained from white and gray matter using automated software (PROBE, G.E., Milwaukee, WI). Spectra(More)
Automated pattern recognition techniques are needed to help radiologists categorize MRS data of brain tumors according to histological type and grade. A major question is whether a computer program "trained" on spectra from one hospital will be able to classify those from another, particularly if the acquisition protocol is different. A subset of 144(More)
A comparison between a time domain analysis algorithm (VARPRO) and a frequency domain analysis algorithm (FITPLAC) for parameter estimation of magnetic resonance spectroscopy (MRS) data series is presented. VARPRO analyses the measured MRS signal (free induction decay; FID); FITPLAC analyses the discrete Fourier transform of the FID, the frequency domain(More)
BACKGROUND 17-allylamino,17-demethoxygeldanamycin (17AAG) is a novel anticancer drug that inhibits heat shock protein 90 (Hsp90), resulting in proteasomal degradation of several oncogenic proteins. We used phosphorus magnetic resonance spectroscopy (31P-MRS) to determine whether 17AAG treatment leads to alterations in phospholipids that could serve as(More)
OBJECTIVES We sought to decipher metabolic processes servicing the increased energy demand during persistent atrial fibrillation (AF) and to ascertain whether metabolic derangements might instigate this arrhythmia. BACKGROUND Whereas electrical, structural, and contractile remodeling processes are well-recognized contributors to the self-perpetuating(More)
We have previously demonstrated (M. Stubbs, Z. M. Bhujwalla, G. M. Tozer, L. M. Rodrigues, R. J. Maxwell, R. Morgan, F. A. Howe, and J. R. Griffiths, NMR Biomed., 5: 351, 1992) that the intracellular pH (pHi) of several rat tumors is higher (> pH 7.0) than that of the tumor extracellular fluid (pHe), in contrast to normal tissues (e.g., liver) in which pHi(More)
MN58b is a novel anticancer drug that inhibits choline kinase, resulting in inhibition of phosphocholine synthesis. The aim of this work was to develop a noninvasive and robust pharmacodynamic biomarker for target inhibition and, potentially, tumor response following MN58b treatment. Human HT29 (colon) and MDA-MB-231 (breast) carcinoma cells were examined(More)