Mass spectrometry of refractory body composition - 6. Structual analysis of peptide and protein by mass spectrometry (2) .

Abstract Context: Previous in vitro studies have demonstrated that the UDP glucuronosyltransferase (UGT)2B15 and UGT2B17 glucuronidate androgens and their metabolites. Objective: Our objective was to determine in vivo whether the UGT2B15 D85Y and the UGT2B17 deletion polymorphisms predict androgen glucuronidation and body composition. Participants: Two population-based cohorts including young adult (n = 1068; age = 18.9 yr) and elderly (n = 1001; age = 75.3 yr) men were included in the study. Main Outcome Measures: Serum and urine levels of testosterone (T) and dihydrotestosterone (DHT) were measured by gas chromatography-mass spectrometry, and serum levels of the major glucuronidated androgen metabolites androstane-3α,17β-diol(androstanediol)-3-glucuronide, androstanediol-17-glucuronide, and androsterone-glucuronide were measured by liquid chromatography-tandem mass spectrometry. Body composition was measured by dual-energy x-ray absorptiometry. Results: Both the UGT2B15 D85Y and the UGT2B17 deletion polymorphisms were associated with serum levels of androstanediol-17-glucuronide (P < 0.001) but not with levels of androstanediol-3-glucuronide or androsterone-glucuronide in both cohorts. Glucuronidation of T and DHT was associated with the UGT2B17 deletion but not with the UGT2B15 D85Y polymorphism, suggested by strong associations between the deletion polymorphism and urine levels of these two hormones. Both polymorphisms were associated with several different measures of fat mass (P < 0.01). The UGT2B17 deletion polymorphism was associated with insulin sensitivity (P < 0.05) as indicated by the homeostasis model assessment index. Conclusions: The UGT2B15 D85Y and the UGT2B17 deletion polymorphisms are both predictors of the glucuronidation pattern of androgens/androgen metabolites. Our findings indicate that UGT2B17 is involved in 17-glucuronidation of mainly T but also of DHT and androstanediol and that UGT2B15 is involved in the 17-glucuronidation of androstanediol. Furthermore, these two polymorphisms are predictors of fat mass in men.

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Reproducibility of gas chromatography–mass spectrometry measurements of 2H labeling of water: Application for measuring body composition in mice

Analytical Biochemistry ◽

10.1016/j.ab.2006.01.020 ◽

2006 ◽

Vol 350 (2) ◽

pp. 171-176 ◽

Cited By ~ 37

Author(s):

Brendan J. McCabe ◽

Ilya R. Bederman ◽

Colleen Croniger ◽

Carrie Millward ◽

Christopher Norment ◽

...

Keyword(s):

Mass Spectrometry ◽

Gas Chromatography ◽

Body Composition ◽

Gas Chromatography Mass Spectrometry ◽

Water Application ◽

Chromatography Mass Spectrometry

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How SIMS microscopy can be used in medicine

Proceedings, annual meeting, Electron Microscopy Society of America ◽

10.1017/s0424820100132649 ◽

1992 ◽

Vol 50 (2) ◽

pp. 1602-1603

Author(s):

Philippe Fragu

Keyword(s):

Mass Spectrometry ◽

Biomedical Applications ◽

Secondary Ion Mass Spectrometry ◽

Chemical Elements ◽

Biological Applications ◽

The Past ◽

Potential Source ◽

Secondary Ion ◽

Chemical Integrity ◽

Scientific Endeavour

The identification, localization and quantification of intracellular chemical elements is an area of scientific endeavour which has not ceased to develop over the past 30 years. Secondary Ion Mass Spectrometry (SIMS) microscopy is widely used for elemental localization problems in geochemistry, metallurgy and electronics. Although the first commercial instruments were available in 1968, biological applications have been gradual as investigators have systematically examined the potential source of artefacts inherent in the method and sought to develop strategies for the analysis of soft biological material with a lateral resolution equivalent to that of the light microscope. In 1992, the prospects offered by this technique are even more encouraging as prototypes of new ion probes appear capable of achieving the ultimate goal, namely the quantitative analysis of micron and submicron regions. The purpose of this review is to underline the requirements for biomedical applications of SIMS microscopy.Sample preparation methodology should preserve both the structural and the chemical integrity of the tissue.

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Imaging of Al-Li-Cu alloys with a Scanning Ion Microprobe

Proceedings, annual meeting, Electron Microscopy Society of America ◽

10.1017/s0424820100135174 ◽

1990 ◽

Vol 48 (2) ◽

pp. 314-315

Author(s):

K.K. Soni ◽

D.B. Williams ◽

J.M. Chabala ◽

R. Levi-Setti ◽

D.E. Newbury

Keyword(s):

Mass Spectrometry ◽

Secondary Ion Mass Spectrometry ◽

Equilibrium Phase ◽

Icosahedral Symmetry ◽

Ion Microprobe ◽

X Ray ◽

Cu Alloys ◽

Two Phases ◽

The University ◽

Secondary Ion

In contrast to the inability of x-ray microanalysis to detect Li, secondary ion mass spectrometry (SIMS) generates a very strong Li+ signal. The latter’s potential was recently exploited by Williams et al. in the study of binary Al-Li alloys. The present study of Al-Li-Cu was done using the high resolution scanning ion microprobe (SIM) at the University of Chicago (UC). The UC SIM employs a 40 keV, ∼70 nm diameter Ga+ probe extracted from a liquid Ga source, which is scanned over areas smaller than 160×160 μm2 using a 512×512 raster. During this experiment, the sample was held at 2 × 10-8 torr.In the Al-Li-Cu system, two phases of major importance are T1 and T2, with nominal compositions of Al2LiCu and Al6Li3Cu respectively. In commercial alloys, T1 develops a plate-like structure with a thickness <∼2 nm and is therefore inaccessible to conventional microanalytical techniques. T2 is the equilibrium phase with apparent icosahedral symmetry and its presence is undesirable in industrial alloys.

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Applications of Time-OF-Flight Secondary Ion Mass Spectrometry (TOF-SIMS)

Proceedings, annual meeting, Electron Microscopy Society of America ◽

10.1017/s0424820100135149 ◽

1990 ◽

Vol 48 (2) ◽

pp. 308-309

Author(s):

Bruno Schueler ◽

Robert W. Odom

Keyword(s):

Mass Spectrometry ◽

Secondary Ion Mass Spectrometry ◽

Structural Information ◽

Time Of Flight ◽

Biological Tissues ◽

Polymer Surfaces ◽

Tof Sims ◽

Secondary Ions ◽

Ion Mass Spectrometry ◽

Secondary Ion

Time-of-flight secondary ion mass spectrometry (TOF-SIMS) provides unique capabilities for elemental and molecular compositional analysis of a wide variety of surfaces. This relatively new technique is finding increasing applications in analyses concerned with determining the chemical composition of various polymer surfaces, identifying the composition of organic and inorganic residues on surfaces and the localization of molecular or structurally significant secondary ions signals from biological tissues. TOF-SIMS analyses are typically performed under low primary ion dose (static SIMS) conditions and hence the secondary ions formed often contain significant structural information.This paper will present an overview of current TOF-SIMS instrumentation with particular emphasis on the stigmatic imaging ion microscope developed in the authors’ laboratory. This discussion will be followed by a presentation of several useful applications of the technique for the characterization of polymer surfaces and biological tissues specimens. Particular attention in these applications will focus on how the analytical problem impacts the performance requirements of the mass spectrometer and vice-versa.

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