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Mobile Lipids (mobile + lipid)

Distribution by Scientific Domains
Medical Sciences80%

Selected Abstracts

1H MRS studies of signals from mobile lipids and from lipid metabolites: comparison of the behavior in cultured tumor cells and in spheroids

NMR IN BIOMEDICINE, Issue 2 2004
Antonella Rosi
Abstract 1H magnetic resonance studies on MCF-7 and HeLa cells were undertaken to reveal differences in lipid and lipid metabolite signals during the growth in culture. High intensity mobile lipid (ML) signals were found during the first days in culture, while afterwards the same signals declined and started increasing again at confluence and at late confluence. At the same time, signals from the lipid metabolite phosphocholine decreased in intensity while signals from glycerophosphocholine in MCF-7 and from choline in HeLa increased as cells approached confluence. Spectral parameters from actively proliferating and non-proliferating cells were used to classify cells with respect to the proliferative conditions by means of a multivariate statistical analysis. Furthermore, it was shown that polyunsaturation of mobile lipid chains was lower in the confluent group with respect to the actively proliferating cells. The examination of spectra from suspensions of MCF-7 spheroids with diameter smaller than 500,,m suggests that cells in spheroids are in condition of lipid metabolism similar to that of confluent cultured cells. Copyright © 2004 John Wiley & Sons, Ltd. [source]

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]

Eliminating spurious lipid sidebands in 1H MRS of breast lesions

MAGNETIC RESONANCE IN MEDICINE, Issue 2 2002
Patrick J. Bolan
Abstract Detecting metabolites in breast lesions by in vivo 1H MR spectroscopy can be difficult due to the abundance of mobile lipids in the breast which can produce spurious sidebands that interfere with the metabolite signals. Two-dimensional J -resolved spectroscopy has been demonstrated in the brain as a means to eliminate these artifacts from a large water signal; coherent sidebands are resolved at their natural frequencies, leaving the noncoupled metabolite resonances in the zero-frequency trace of the 2D spectrum. This work demonstrates that using the zero-frequency trace,or equivalently the average of spectra acquired with different echo times,can be used to separate noncoupled metabolite signals from the lipid-induced sidebands. This technique is demonstrated with simulations, phantom studies, and in several breast lesions. Compared to the conventional approach using a single echo time, echo time averaging provides increased sensitivity for the study of small and irregularly shaped lesions. Magn Reson Med 48:215,222, 2002. © 2002 Wiley-Liss, Inc. [source]

1H MRS studies of signals from mobile lipids and from lipid metabolites: comparison of the behavior in cultured tumor cells and in spheroids

NMR IN BIOMEDICINE, Issue 2 2004
Antonella Rosi
Abstract 1H magnetic resonance studies on MCF-7 and HeLa cells were undertaken to reveal differences in lipid and lipid metabolite signals during the growth in culture. High intensity mobile lipid (ML) signals were found during the first days in culture, while afterwards the same signals declined and started increasing again at confluence and at late confluence. At the same time, signals from the lipid metabolite phosphocholine decreased in intensity while signals from glycerophosphocholine in MCF-7 and from choline in HeLa increased as cells approached confluence. Spectral parameters from actively proliferating and non-proliferating cells were used to classify cells with respect to the proliferative conditions by means of a multivariate statistical analysis. Furthermore, it was shown that polyunsaturation of mobile lipid chains was lower in the confluent group with respect to the actively proliferating cells. The examination of spectra from suspensions of MCF-7 spheroids with diameter smaller than 500,,m suggests that cells in spheroids are in condition of lipid metabolism similar to that of confluent cultured cells. Copyright © 2004 John Wiley & Sons, Ltd. [source]

Correlation between the occurrence of 1H-MRS lipid signal, necrosis and lipid droplets during C6 rat glioma development

NMR IN BIOMEDICINE, Issue 4 2003
Sonja Zoula
Abstract The aim of this study was to investigate the possible correlation between the 1H MRS mobile lipid signal, necrosis and lipid droplets in C6 rat glioma. First, the occurrence of necrosis and lipid droplets was determined during tumor development, by a histological analysis performed on 34 rats. Neither necrosis nor lipid droplets were observed before 18 days post-implantation. At later stages of development, both necrosis and lipid droplets were apparent, the lipid droplets being mainly located within the necrotic areas. Using a second group of eight rats, a temporal correlation was evidenced between mobile lipid signal detected by in vivo single-voxel one- (136,ms echo time) and two-dimensional J -resolved 1H MR spectroscopy, and the presence of necrosis and lipid droplets on the histological sections obtained from the brains of the same rats. Finally, spatial distribution of the mobile lipid signal was analyzed by chemical-shift imaging performed on a third group of eight animals, at the end of the tumor growth. The spectroscopic image corresponding to the resonance of mobile lipids had its maximum intensity in the center of the tumor where necrotic regions were observed on the histological sections. These necrotic areas contained large amounts of lipid droplets. All these results suggest that mobile lipids detected in vivo by 1H MRS (136,ms echo time) in C6 rat brain glioma arise mainly from lipid droplets located in necrosis. Copyright © 2003 John Wiley & Sons, Ltd. [source]