Article
Lipid mapping of colonic mucosa by cluster TOF-SIMS imaging and multivariate analysis in cftr knockout mice.
Centre de Recherche de Gif, Institut de Chimie des Substances Naturelles, CNRS, Gif-sur-Yvette, France.
The Journal of Lipid Research (impact factor:
5.56).
10/2010;
51(10):3034-45.
DOI:10.1194/jlr.M008870
Source: PubMed
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Article: Vitamin E imaging and localization in the neuronal membrane.
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ABSTRACT: Vitamin E (alpha-tocopherol) has been implicated in several cellular processes including signaling, transport, lipid membrane curvature, and several neurodegenerative disorders. Vitamin E imaging has been hindered by the inaccessibility of the molecule to traditional immunohistochemical methods. Using time-of-flight secondary ion mass spectrometry (ToF-SIMS), the distribution of major constituents in the cellular membrane of isolated neurons was investigated. There is a significant increase in the vitamin E signal at the soma-neurite junction compared to the cell as a whole (165 +/- 11% of that found across the cell, p = 0.004, n = 12). The observed membrane distribution suggests an important new role for vitamin E in neuronal function.Journal of the American Chemical Society 10/2005; 127(35):12152-3. · 9.91 Impact Factor -
Article: A C60 primary ion beam system for time of flight secondary ion mass spectrometry: its development and secondary ion yield characteristics.
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ABSTRACT: A buckminsterfullerene (C60)-based primary ion beam system has been developed for routine application in TOF-SIMS analysis of organic materials. The ion beam system is described, and its performance is characterized. Nanoamp beam currents of C60+ are obtainable in continuous current mode. C60(2+) can be obtained in pulsed mode. At 10 keV, the beam can be focused to less than 3 microm with 0.1 nA currents. TOF-SIMS studies of a series of molecular solids and a number of polymer systems in monolayer and thick film forms are reported. Very significant enhancement of secondary ion yields, particularly at higher mass, were observed using 10-keV C60+ for all samples other than PTFE, as compared to those observed from 10 keV Ga+ primary ions. Three materials (PS2000, Irganox 1010, PET) were studied in detail to investigate primary ion-induced disappearance (damage) cross sections to determine the increase in secondary ion formation efficiency. The C60 disappearance cross sections observed from monolayer film PS2000 and self-supporting PET film are close to those observed from Ga+. The resulting C60 efficiencies are 30-100 times those observed from gallium. The cross sections observed from C60 bombardment of multilayer molecular solids are approximately 100 times less, such that essentially zero damage sputtering is possible. The resulting efficiencies are > 10(3) greater than from gallium. It is also shown that C60 primary ions do not generate any more low-mass fragments than any other ion beam system does. C60 is shown to be a very favorable ion beam system for TOF-SIMS, delivering high yield, close to 10% total yield, favoring high-mass ions, and on thick samples, offering the possibility of analysis well beyond the static limit.Analytical Chemistry 04/2003; 75(7):1754-64. · 5.86 Impact Factor -
Article: Chemical imaging on liver steatosis using synchrotron infrared and ToF-SIMS microspectroscopies.
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ABSTRACT: Fatty liver or steatosis is a frequent histopathological change. It is a precursor for steatohepatitis that may progress to cirrhosis and in some cases to hepatocellular carcinoma. In this study we addressed the in situ composition and distribution of biochemical compounds on tissue sections of steatotic liver using both synchrotron FTIR (Fourier transform infrared) and ToF-SIMS (time of flight secondary ion mass spectrometry) microspectroscopies. FTIR is a vibrational spectroscopy that allows investigating the global biochemical composition and ToF-SIMS lead to identify molecular species in particular lipids. Synchrotron FTIR microspectroscopy demonstrated that bands linked to lipid contribution such as -CH(3) and -CH(2) as well as esters were highly intense in steatotic vesicles. Moreover, a careful analysis of the -CH(2) symmetric and anti-symmetric stretching modes revealed a slight downward shift in spectra recorded inside steatotic vesicles when compared to spectra recorded outside, suggesting a different lipid environment inside the steatotic vesicles. ToF-SIMS analysis of such steatotic vesicles disclosed a selective enrichment in cholesterol as well as in diacylglycerol (DAG) species carrying long alkyl chains. Indeed, DAG C36 species were selectively localized inside the steatotic vesicles whereas DAG C30 species were detected mostly outside. Furthermore, FTIR detected a signal corresponding to olefin (C = C, 3000-3060 cm(-1)) and revealed a selective localization of unsaturated lipids inside the steatotic vesicles. ToF-SIMS analysis definitely demonstrated that DAG species C30, C32, C34 and C36 carrying at least one unsaturated alkyl chain were selectively concentrated into the steatotic vesicles. On the other hand, investigations performed on the non-steatotic part of the fatty livers have revealed important changes when compared to the normal liver. Although the non-steatotic regions of fatty livers exhibited normal histological aspect, IR spectra demonstrated an increase in the lipid content and ToF-SIMS detected small lipid droplets corresponding most likely to the first steps of lipid accretion.PLoS ONE 01/2009; 4(10):e7408. · 4.09 Impact Factor
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Keywords
cftr knockout mouse model
cluster time
colonic mucosa
different structural regions
epithelial border
fatty acid imbalance
flight secondary-ion mass spectrometry
intestinal mucosa
intestinal obstruction
lamina propria
localize lipid alterations
multivariate analyses
multivariate statistical methods
partitioning clustering
phosphatidylinositol glycerolipids
powerful tool
Principal component analysis
Significant increases
vitamin E
WT individuals