Time of flight-secondary ion mass spectrometry (ToF-SIMS) is an ideal technique for probing lipids in situ in cells and other biological material. Sophisticated advances in instrumentation and ...methodology mean that higher sensitivity can be achieved than ever before, and in the quest to fight diseases prevalent in the twenty-first century, ToF-SIMS is a powerful addition to the analytical toolbox. Lipids play an essential role in cellular biochemical processes and as such, the malfunction of lipid synthesis pathways can result in disease. This article provides essential background to the technique and an overview of the current applications of ToF-SIMS in cancer and other diseases which have particular implications for lipid biochemistry. Challenges and successes are discussed.
Celotno besedilo
Dostopno za:
DOBA, IZUM, KILJ, NUK, PILJ, PNG, SAZU, UILJ, UKNU, UL, UM, UPUK
Prostate cancer (CaP) preferentially metastasises to the bone, and we have previously shown that the poly-unsaturated fatty acid (PUFA) arachidonic acid (AA) is a potent stimulator of CaP invasion. ...Here we present that AA promotes CaP invasion by inducing bone marrow adipocyte formation.
Boyden invasion-chamber assays assessed the ability of dietary oils, their PUFA components, and specific PUFA-loaded adipocytes to induce PC-3 invasion. Lipid transfer and metabolism was followed using deuterated AA and Fourier Transform Infrared spectroscopy (FTIR).
Poly-unsaturated fatty acid constituents, but not their corresponding dietary oils, induced PC-3 invasion. PUFAs induce bone marrow adipocyte (BM-Ad) differentiation with AA inducing higher levels of BM-Ad differentiation, as compared with other PUFAs (3998+/-514.4 vs 932+/-265.8; P=0.00002), which stimulated greater PC-3 invasion than free AA (22 408.5+/-607.4 vs 16 236+/-313.9; P=0.01111) or adipocytes generated in the presence of other PUFAs. In bone marrow co-culture PC-3 and BM-Ad interactions result in direct uptake and metabolism of AA by PC-3 cells, destruction of the adipocyte and subsequent formation of a bone metastasis.
The data supports the hypothesis that AA not only promotes CaP invasion, it also prepares the 'soil', making it more supportive for implantation and propagation of the migrating metastatic cell.
A liquid metal ion source (LMIS) based upon a gold/germanium eutectic has been developed. The LMIS emits a variety of ions including monatomic gold and gold clusters. Gold ions have been utilised for ...SIMS analysis of the polypeptide gramicidin and the polymer poly(ethylene-terepthalate) (PET). It has been found that monatomic gold (Au
+) increases secondary ion yields up to a factor of four compared to gallium, for both gramicidin and PET. The Au
3
+ cluster produces a strong non-linear increase in yield over monatomic gold, for both gramicidin and PET. This effect is greatest at high mass, the yield for the gramicidin molecular ion increasing by a factor of over 60. No evidence has been found to suggest increased fragmentation as a result of cluster ion bombardment. The LMIS also exhibits good static SIMS imaging capacity.
In this work we investigate superconducting properties of niobium samples via application of the muon spin rotation/relaxation (μSR ) technique. We employ for the first time the μSR technique to ...study samples that are cut out from large and small grain 1.5 GHz radio frequency (rf) single cell niobium cavities. The rf test of these cavities was accompanied by full temperature mapping to characterize the rf losses in each of the samples. Results of the μSR measurements show that standard cavity surface treatments like mild baking and buffered chemical polishing performed on the studied samples affect their surface pinning strength. We find an interesting correlation between high field rf losses and field dependence of the sample magnetic volume fraction measured via μSR . The μSR line width observed in zero-field-μSR measurements matches the behavior of Nb samples doped with minute amounts of Ta or N impurities. A lower and an upper bound for the upper critical field Hc2 of these cutouts is found.
This paper reviews the results obtained with a C
60-based ion beam system developed for routine application in ToF-SIMS analysis of organic materials. The bombardment of some representative organic ...materials by C
60
+ results in yield enhancements of at least 30–100-fold as compared to yields observed under Ga
+ bombardment at the same energy. The total ion yields for C
60
+ are in the order of 1–10%. High molecular-weight polymers and monolayer molecular solids are damaged at about the same rate as under Ga
+ bombardment. Thick films of molecular solids show ∼100 times less damage than Ga
+, such that essentially zero damage sputtering is possible, offering the possibility of analysis well beyond the static limit. The resulting efficiencies are greater than other polyatomic primary ions such as Au
3
+ or SF
5
+ and >10
3 for Ga
+. C
60
+ delivers no more molecular fragmentation than any other primary projectile used in SIMS. Some results on biological test samples to access the potential of the C
60
+ as a primary ion beam in bio-system analysis are reported. A brief discussion on a possible mechanism for ion enhancement by C
60
+ is presented.
We present a TOF-SIMS analysis of the cell surface differences between four yeast strains from two species, Candida glabrata and Saccharomyces cerevisiae (haploid strains BY4742 and BY4741 and the ...derived diploid BY4743). The study assesses the suitability of TOF-SIMS analysis in combination with statistical methods (principal component analysis, Fisher's discriminant analysis, and cluster analysis) for the discrimination between the four yeast strains. We demonstrate that a combination of these statistical methods identifies 34 ions, from a total data set of 1200, which can be used to distinguish between the four yeasts. The study discusses the assignments of surface cell membrane phospholipids for the identified ions and the resulting differences in the phospholipid pattern between the four yeasts, particularly in relation to ploidy and budding pattern. The method shows that fatty acids, phosphatidylglycerols, phosphatidylethanolamines, phosphatidylserines, and phosphatidylcholines, as well as cardiolipins, are of diagnostic importance.
PDF
