25 research outputs found
Toward dynamic isotopomer analysis in the rat brain in vivo: automatic quantitation of 13C NMR spectra using LCModel
The LCModel method was adapted to analyze localized in vivo (13)C NMR spectra obtained from the rat brain in vivo at 9.4 T. Prior knowledge of chemical-shifts, J-coupling constants and J-evolution was included in the analysis. Up to 50 different isotopomer signals corresponding to 10 metabolites were quantified simultaneously in 400 microl volumes in the rat brain in vivo during infusion of [1,6-(13)C(2)]glucose. The analysis remained accurate even at low signal-to-noise ratio of the order of 3:1. The relative distribution of isotopomers in glutamate, glutamine and aspartate determined in vivo in 22 min was in excellent agreement with that measured in brain extracts. Quantitation of time series of (13)C spectra yielded time courses of total (13)C label incorporation into up to 16 carbon positions, as well as time courses of individual isotopomer signals, with a temporal resolution as low as 5 min (dynamic isotopomer analysis). The possibility of measuring in vivo a wealth of information that was hitherto accessible only in extracts is likely to expand the scope of metabolic studies in the intact brain
Artefact 2001 : Sculptures urbaines : Du latin artis facta : les effets de l'art = Artefact 2001 : Urban Sculptures : Artis Facta in Latin Means the Effects of Art
Catalogue for the first presentation of a triennial event in which ten artists created site-specific public artworks along the Lachine Canal (Montreal). Five authors (including curator G. Daigneault) examine the works according to their connection with the site and its history, while also discussing topics such as: the “urban landscape”, the socio-historical role of the Canal, machines and industrial heritage. Includes documentation of a gallery exhibition based on the projects. Texts in French and English. Biographical notes on artists and authors; circa 30 bibl. ref
Anaemia as an independent key risk factor for major haemorrhage in patients treated with vitamin K antagonists: Results of the SCORE prospective cohort
International audienc
Standardized Procedure for the Simultaneous Determination of the Matrix Effect, Recovery, Process Efficiency, and Internal Standard Association
The
matrix effects (MEs) on the quantification of an analyte can
be significant and should not be neglected during development and
validation of an analytical method. According to this premise, we
developed a standardized procedure based on a set of six tests performed
on six different sample matrices to detect and characterize the effects
of the matrix for single and multiple analytes methods. The link between
the matrix effect, recovery, process efficiency, accuracy, precision,
and calibration curve was underscored by calculations performed with
peak areas, ratios of standard/internal standard peak area, and concentrations.
The terms instrumental ME and global ME were introduced, and the term
recovery was subdivided for clarity. The test accounts for the presence
of ubiquitous and endogenous analytes through background subtraction.
The results showed the necessity for using samples with an original
concentration in the same range and that the concentration selected
for the addition had a definite impact on the results. The use of
six-sample matrices provided a standard deviation on the results,
and this information could be inserted in a method performance result
to show precision. The tool also allows for testing of different analytes/internal
standard combinations, which helps with the selection of the association
with minimum MEs. A UPLC-MS/MS method for the quantification of several
phthalate metabolites in urine was developed and validated with this
test. This methodology responds to a scientific need for homogeneity,
clarity, and understanding of the results and facilitates the decision-making
process while lowering the required costs and time
Phase III study of bevacizumab plus docetaxel compared with placebo plus docetaxel for the first-line treatment of human epidermal growth factor receptor 2-negative metastatic breast cancer
The efficacy and safety of combining bevacizumab (7.5 and 15 mg/kg) with docetaxel as first-line therapy for human epidermal growth factor receptor 2 (HER2) -negative, locally recurrent or metastatic breast cancer (MBC) was investigated in a three-arm, placebo-controlled, phase III trial.Patients (N = 736) were randomly assigned to docetaxel 100 mg/m(2) plus either placebo or bevacizumab 7.5 or 15 mg/kg every 3 weeks. The primary end point was progression-free survival (PFS); secondary end points included best overall response, duration of response, time to treatment failure, overall survival, and safety.Combination of bevacizumab 15 mg/kg, but not 7.5 mg/kg, with docetaxel showed superior median PFS (mPFS) to placebo plus docetaxel in unstratified analysis (placebo mPFS, 8.2 months; 7.5 mg/kg mPFS, 9.0 months [hazard ratio (HR), 0.86; P = .12]; 15 mg/kg mPFS, 10.1 months [HR, 0.77; P = .006]) and stratified analysis (placebo mPFS, 8.1 months; 7.5 mg/kg mPFS, 9.0 months [HR, 0.80; P = .045]; 15 mg/kg mPFS, 10.0 months [HR, 0.67; P < .001]). Response rates in patients with measurable disease at baseline also increased with bevacizumab 15 mg/kg (46\% [placebo] v 55\% [7.5 mg/kg; P = .07] and 64\% [15 mg/kg; P < .001]). Combination with bevacizumab had limited impact on the known toxicity profile of docetaxel.Combination of bevacizumab with docetaxel did not significantly impact on the safety profile of docetaxel. Bevacizumab 15 mg/kg every 3 weeks significantly increased PFS when combined with docetaxel as first-line therapy for MBC compared with docetaxel plus placebo