26 research outputs found
Development of a fast LC-MS/MS protocol for combined measurement of six LSDs on dried blood spot in a newborn screening program
Detection of DNA Sequence Variations in Homo- and Heterozygous Samples via Molecular Mass Measurements by Electrospray Ionization Time-of-Flight Mass Spectrometry
Letter: Support for the proposed observation by ionspray mass spectrometry of piroxicam/β-cyclodextrin and terfenadine/β cyclodextrin non-covalent inclusion complexes
Development of a highly sensitive method for the quantification of estrone and estradiol in serum by liquid chromatography tandem mass spectrometry without derivatization
SMART-E: A TOOL FOR ENERGY DEMAND SIMULATION AND OPTIMIZATION AT THE CITY SCALE
International audienceAdding flexibility to the demand may rationalize energy production. Indeed, it should be possible to maximize the use of low CO2 and low-cost energy production systems by managing the demand at the city scale. In this context, numerical simulation may be a great help for setting up various demand response (DR) strategies in a short-term. For that purpose, a simulation environment called Smart-E which focuses on the thermal and electrical uses of energy in dwellings and commercial buildings has been developed. This library of algorithms is specially designed to simulate hypothetical or real cities and it uses techno-explicit bottom-up models fed with public databases and the specific users’ data. First the paper presents the Smart-E tool architecture. Then, a case study is conducted on a French typical medium city to show how Smart-E may help the aggregator to predict the impact of specific DR strategies. For this purpose two load shedding strategies are tested at the city scale with indoor temperature comfort criteria. Strategies reduce maximum electric power for heating by 25% for 24h
Proteomic analysis of high-density lipoprotein
Plasma lipoproteins, such as high-density lipoprotein (HDL), can serve as carriers for a wide range of proteins that are involved in processes such as lipid metabolism, thrombosis, inflammation and atherosclerosis. The identification of HDL-associated proteins is essential with regards to understanding these processes at the molecular level. In this study, a combination of proteomic approaches including 1-DE and 2-DE MALDI-TOF, isotope-coded affinity tag and Western blot analysis were employed to identify proteins associated with human HDL. To minimize potential losses of HDL-associated proteins during isolation, a one-step ultracentrifugation technique was applied and the quality of purified HDL was confirmed by nephelometry, high-performance gel chromatography, and Western blot analysis. MS analysis revealed the presence of 56 HDL-associated proteins including all known apolipoproteins and lipid transport proteins. Furthermore, proteins involved in hemostasis and thrombosis, the immune and complement system were found. In addition, growth factors, receptors, hormone-associated proteins and many other proteins were found to be associated with HDL. Our approach thus resulted in the identification of a large number of proteins associated with HDL. The combination of proteomic technologies proved to be a powerful and comprehensive tool for the identification of proteins on HD
Analysis of organo-chlorine pesticides residue in raw coffee with a modified “quick easy cheap effective rugged and safe” extraction/clean up procedure for reducing the impact of caffeine on the gas chromatography–mass spectrometry measurement
Development and validation of LC-MS/MS method for imatinib and norimatinib monitoring by finger-prick DBS in gastrointestinal stromal tumor patients.
The introduction of imatinib, an oral tyrosine kinase inhibitor, as first-line standard therapy in patients with unresectable, metastatic, or recurrent gastro-intestinal stromal tumor (GIST), strongly improved their treatment outcomes. However, therapeutic drug monitoring (TDM) is recommended for this drug due to the large inter-individual variability in plasma concentration when standard dose is administered. A Cmin higher than 760 ng/mL was associated with a longer progression free survival. Thus, a LC-MS/MS method has been developed and fully validated to quantify imatinib and its active metabolite, norimatinib, in finger-prick dried blood spot (DBS). The influence of hematocrit, sample homogeneity, and spot size and the correlation between finger-prick and venous DBS measurements were also assessed. The method showed a good linearity (R2 > 0,996) between 50-7500 ng/mL for imatinib and 10-1500 ng/mL for norimatinib. Analytes were extracted from DBS samples by simply adding to 3 mm-discs 150 μL of acidified methanol containing IMA-D8. The collected extract was then injected on a LC Nexera system in-house configured for the on-line cleanup, coupled with an API-4000 QT. The chromatographic separation was conducted on a Synergi Fusion-RP column (4 μm, 2x50 mm) while the trapping column was a POROS R1/20 (20 μm, 2x30 mm). The total run time was 8.5 min. DBSs stored at room temperature in plastic envelopes containing a silica-gel drying bag were stable up to 16 months. The proposed method was applied to 67 clinical samples, showing a good correlation between patients' finger-prick DBS and plasma concentrations, measured by the reference LC-MS/MS method, internally validated. Imatinib and norimatinib concentrations found in finger-prick DBS were adjusted by hematocrit or by an experimental correction factor to estimate the corresponding plasma measurements. At the best of our knowledge, the proposed LC-MS/MS method is the first analytical assay to measure imatinib and norimatinib in DBS samples
Enzyme-Based Electrochemical Biosensor for Therapeutic Drug Monitoring of Anticancer Drug Irinotecan
Therapeutic drug
monitoring (TDM) is the clinical practice of measuring
pharmaceutical drug concentrations in patients’ biofluids at
designated intervals, thus allowing a close and timely control of
their dosage. To date, TDM in oncology can only be performed by trained
personnel in centralized laboratories and core facilities employing
conventional analytical techniques (e.g., MS). CPT-11 is an antineoplastic
drug that inhibits topoisomerase type I, causing cell death, and is
widely used in the treatment of colorectal cancer. CPT-11 was also
found to directly inhibit acetylcholine esterase (AChE), an enzyme
involved in neuromuscular junction. In this work, we describe an enzymatic
biosensor, based on AChE and choline oxidase (ChOx), which can quantify
CPT-11. ACh (acetylcholine) substrate is converted to choline, which
is subsequently metabolized by ChOx to give betaine aldehyde and hydrogen
peroxide. The latter one is then oxidized at a suitably polarized
platinum electrode, providing a current transient proportional to
the amount of ACh. Such an enzymatic process is hampered by CPT-11.
The biosensor showed a ∼60% maximal inhibition toward AChE
activity in the clinically relevant concentration range 10–10 000
ng/mL of CPT-11 in both simple (phosphate buffer) and complex (fetal
bovine serum) matrixes, while its metabolites showed negligible effects.
These findings could open new routes toward a real-time TDM in oncology,
thus improving the therapeutic treatments and lowering the related
costs