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https://www.readbyqxmd.com/read/26707914/development-of-new-quantitative-mass-spectrometry-and-semi-automatic-isofocusing-methods-for-the-determination-of-apolipoprotein-e-typing
#1
Christophe Hirtz, Jerome Vialaret, Georges Nouadje, Susanna Schraen, Pascale Benlian, Sandrine Mary, Pascal Philibert, Laurent Tiers, Pauline Bros, Constance Delaby, Audrey Gabelle, Sylvain Lehmann
BACKGROUND: Apolipoprotein E (Apo E) is a 36 Kda glycoprotein involved in lipid transport. It exists in 3 major isoforms: E2, E3 and E4. ApoE status is known to be a major risk factor for late-onset Alzheimer's and cardiovascular diseases. Genotyping is commonly used to obtain ApoE status but can show technical issues with ambiguous determinations. Phenotyping can be an alternative, not requiring genetic material. We evaluated the ability to accurately type ApoE isoforms by 2 phenotyping tests in comparison with genotyping...
February 15, 2016: Clinica Chimica Acta; International Journal of Clinical Chemistry
https://www.readbyqxmd.com/read/26226314/quantification-of-remifentanil-and-propofol-in-human-plasma-a-lc-ms-ms-assay-validated-according-to-the-ema-guideline
#2
Jean Claude Alvarez, Emuri Abe, Isabelle Etting, Morgan Le Guen, Philippe Devillier, Stanislas Grassin-Delyle
BACKGROUND: Remifentanil and propofol are often used in combination for general anesthesia. We developed a method using LC-MS for their simultaneous measurement in human plasma. Methodology & results: After addition of remifentanil-(13)C6 and propofol-d18 (IS), 500 µl of plasma were extracted with ethylacetate/hexane. Analysis conditions included gradient elution (water/acetonitrile), electrospray ionization and detection with a triple quadripole mass spectrometer. Remifentanil and propofol were ionized in the positive and negative mode, respectively...
2015: Bioanalysis
https://www.readbyqxmd.com/read/25582721/-mass-spectrometry-and-clinical-proteomics
#3
REVIEW
Bruno Baudin
Proteomic analysis was promising from many years proposing new markers of pathologies and new targets for drug development. Constant progress in technics makes proteomics more efficient. This progress needs the development of mass spectrometers more precise on mass determination, more resolutive on ions separation, more sensitive for their detection, much more adapted to quantification of peaks, and with automated apparatus built for high throughput proteomics. MALDI-TOF keeps an important place in proteomics, as well as for low budget teams as for laboratories developing quantification and high throughput with TOF/TOF mode...
January 2015: Annales de Biologie Clinique
https://www.readbyqxmd.com/read/24930405/a-simple-robust-and-rapid-approach-to-detect-carbapenemases-in-gram-negative-isolates-by-maldi-tof-mass-spectrometry-validation-with-triple-quadripole-tandem-mass-spectrometry-microarray-and-pcr
#4
COMPARATIVE STUDY
C Vogne, G Prod'hom, K Jaton, L A Decosterd, G Greub
Carbapenemases should be accurately and rapidly detected, given their possible epidemiological spread and their impact on treatment options. Here, we developed a simple, easy and rapid matrix-assisted laser desorption ionization-time of flight (MALDI-TOF)-based assay to detect carbapenemases and compared this innovative test with four other diagnostic approaches on 47 clinical isolates. Tandem mass spectrometry (MS-MS) was also used to determine accurately the amount of antibiotic present in the supernatant after 1 h of incubation and both MALDI-TOF and MS-MS approaches exhibited a 100% sensitivity and a 100% specificity...
December 2014: Clinical Microbiology and Infection
https://www.readbyqxmd.com/read/23084788/measurement-of-atropine-and-scopolamine-in-hair-by-lc-ms-ms-after-datura-stramonium-chronic-exposure
#5
Florian Ricard, Emuri Abe, Charlotte Duverneuil-Mayer, Philippe Charlier, Geoffroy de la Grandmaison, Jean Claude Alvarez
BACKGROUND: Datura stramonium is an herbaceous annual plant. All parts of the plant contain tropane alkaloids such as atropine and scopolamine. We report the case of a 22-year-old man admitted to a general hospital for visual and aural hallucinations. One week after his admission, as the hallucinations remained, the patient was transferred to a psychiatric hospital. Neither blood nor urine was conserved during his hospitalization, so a hair analysis was requested in order to identify a possible consumption of a Datura seed infusion...
November 30, 2012: Forensic Science International
https://www.readbyqxmd.com/read/20352024/identification-of-crystallin-modifications-in-the-human-lens-cortex-and-nucleus-using-laser-capture-microdissection-and-cydye-labeling
#6
C O Asomugha, R Gupta, O P Srivastava
PURPOSE: With aging, lens crystallins undergo post-translational modifications (PTMs) and these modifications are believed to play a major role in age-related cataract development. The purpose of the present study was to determine the protein profiles of crystallins and their PTMs in the cortical and nuclear regions within an aging human lens to gain a better understanding about changes in crystallins as fiber cells migrate from cortical to nuclear region. METHODS: Laser capture microdissection (LCM) was used to select and capture cells from cortical and nuclear regions of 12 mum, optimum cutting temperature (OCT) compound-embedded frozen lens sections from a 69-year-old human lens...
March 23, 2010: Molecular Vision
https://www.readbyqxmd.com/read/20222116/synovial-fluid-proteins-differentiate-between-the-subtypes-of-juvenile-idiopathic-arthritis
#7
Margalit E Rosenkranz, David C Wilson, Anthony D Marinov, Alisha Decewicz, Patrick Grof-Tisza, David Kirchner, Brendan Giles, Paul R Reynolds, Michael N Liebman, V S Kumar Kolli, Susan D Thompson, Raphael Hirsch
OBJECTIVE: Juvenile idiopathic arthritis (JIA) is a heterogeneous group of inflammatory diseases, and no clinically useful prognostic markers to predict disease outcome in children with JIA are currently available. Synovial fluid likely reflects the proteins present in the inflamed synovium. The purpose of this study was to delineate the synovial fluid proteome and determine whether protein expression differs in the different subtypes of JIA. METHODS: Synovial fluid samples obtained from children with oligoarticular JIA, polyarticular JIA, or systemic JIA were compared...
June 2010: Arthritis and Rheumatism
https://www.readbyqxmd.com/read/17291782/effects-of-neuronal-magnetic-fields-on-mri-numerical-analysis-with-axon-and-dendrite-models
#8
COMPARATIVE STUDY
Tae Seok Park, Soo Yeol Lee
Whether the neuronal magnetic fields (NMFs) could cause measurable MRI signal changes in the human brain seems to be still controversial. In this study, we have numerically investigated the NMF effects on the MRI signal using two separate current source models for axons and dendrites. Since intracellular current distributions are different in axons and dendrites, the NMFs emanating from axons and dendrites are also very different from each other. Due to the quadripole configuration of the intracellular current flowing through an axon, the axonal magnetic field is bipolar causing virtually no changes in the MRI signal...
April 1, 2007: NeuroImage
https://www.readbyqxmd.com/read/15874897/characterization-of-a-morphine-like-molecule-in-secretory-granules-of-chromaffin-cells
#9
Yannick Goumon, Jean-Marc Strub, George B Stefano, Alain Van Dorsselaer, Dominique Aunis, Marie-Hélène Metz-Boutigue
BACKGROUND: Morphine and morphine-like molecules were identified in numerous mammalian tissues. In particularly, morphine was present in adrenal gland and in PC-12 cells, corresponding to the cell line derived from rat adrenal medullary chromaffin cells. MATERIAL/METHODS: Morphine-like compounds were isolated after a deproteinization followed by a reverse phase high pressure chromatography purification coupled to a UV detector. This alkaloid was identified using nano-eletrospray ionization quadripole time of flight tandem mass spectrometry...
May 2005: Medical Science Monitor: International Medical Journal of Experimental and Clinical Research
https://www.readbyqxmd.com/read/15866528/a-validated-liquid-chromatography-mass-spectrometry-method-for-the-determination-of-leukotrienes-b4-and-b5-produced-by-stimulated-human-polymorphonuclear-leukocytes
#10
A Panchaud, L Avois, M Roulet, M Pilet, C Hug, M Saugy, L A Decosterd
A validated high-performance liquid chromatography (HPLC)-mass spectrometry method has been developed for the simultaneous assay of leukotrienes (LTs) B4 and B5, derived from omega-6 arachidonic acid and omega-3 polyunsaturated fatty acids (PUFA), respectively, produced by human polymorphonuclear leukocytes (PMNLs) stimulated with calcium ionophore A23187. The HPLC separation of PMNL ether extracts was performed on a reversed-phase column using a gradient elution program of 15 mM ammonium acetate and MeOH. Detection was performed by electrospray ionization-single quadripole mass spectrometry using single ion reaction monitoring in the negative mode at m/z 333...
June 1, 2005: Analytical Biochemistry
https://www.readbyqxmd.com/read/15833290/intracellular-measurements-of-anti-hiv-drugs-indinavir-amprenavir-saquinavir-ritonavir-nelfinavir-lopinavir-atazanavir-efavirenz-and-nevirapine-in-peripheral-blood-mononuclear-cells-by-liquid-chromatography-coupled-to-tandem-mass-spectrometry
#11
S Colombo, A Beguin, A Telenti, J Biollaz, T Buclin, B Rochat, L A Decosterd
A sensitive and accurate liquid chromatography-tandem mass spectrometric (LC-MS/MS) method for the intracellular determination of nine antiretroviral drugs in human peripheral blood mononuclear cells (PBMCs) is proposed. PBMCs are isolated by density gradient centrifugation using Vacutainer CPT tubes and cell count is performed with a Coulter instrument. Single-step extraction of drugs from PBMCs pellets is performed with MeOH 50% (with clozapine added as internal standard, I.S.) and the supernatant is injected onto a 2...
May 25, 2005: Journal of Chromatography. B, Analytical Technologies in the Biomedical and Life Sciences
https://www.readbyqxmd.com/read/15729828/towards-gas-chromatography-mass-spectrometry-coupling-protocols-for-both-identifying-and-quantification-essential-oils-of-thymus-capitatus-hoff-et-link
#12
Lassaad Hedhili, Mehrez Romdhane, Henri Planche, Manef Abderrabba
Essential oil of Thymus capitatus Hoff et Link is analysed by using four techniques: GC/pyrolyse/MS, GC/FID, electronic impact GC/MS (quadripole), and GC/MS (ion trap). Both major and trace components are analysed. The GC/pyrolyse/MS coupling provides reference to the exact mass compositions without any need of the previously purified references, neither for major or trace components. The comparison between this reference analysis and GC/FID shows that the FID response coefficients may vary by a mean 7% from one component to another...
January 28, 2005: Journal of Chromatography. A
https://www.readbyqxmd.com/read/15047298/modeling-ndt-piezoelectric-ultrasonic-transmitters
#13
J L San Emeterio, A Ramos, P T Sanz, A Ruíz, A Azbaid
Ultrasonic NDT applications are frequently based on the spike excitation of piezoelectric transducers by means of efficient pulsers which usually include a power switching device (e.g. SCR or MOS-FET) and some rectifier components. In this paper we present an approximate frequency domain electro-acoustic model for pulsed piezoelectric ultrasonic transmitters which, by integrating partial models of the different stages (driving electronics, tuning/matching networks and broadband piezoelectric transducer), allows the computation of the emission transfer function and output force temporal waveform...
April 2004: Ultrasonics
https://www.readbyqxmd.com/read/11538512/orthostatic-stress-by-lower-body-negative-pressure-and-its-body-fluid-distribution-kinetics-under-microgravity
#14
F J Baisch
To support the hypothesis that interstitial fluid loss is one of the components of the "cardiovascular deconditioning" induced by space flight, a series of three experiments was performed in one subject, after 5 days in space: 1) standard thigh cuffs were inflated up to suprasystolic pressure values (CUFF I) for two minutes, 2) Half an hour later a lower body negative pressure test (LBNP) followed with -15 mmHg for 15, -30 mmHg for 5, and -40 mmHg for 15 minutes, 3) Twenty minutes after that, the CUFF maneuver was repeated (CUFF II)...
February 1993: Physiologist
https://www.readbyqxmd.com/read/8241718/body-fluid-distribution-in-man-in-space-and-effect-of-lower-body-negative-pressure-treatment
#15
F J Baisch
The lack of hydrostatic forces in space eventually produces a fluid deficit within the circulatory system. This deficit may alter the circulatory regulation patterns. The aim of the present study was to determine how much of this fluid deficit is attributable to interstitial fluid losses and to determine the effects of lower body negative pressure (LBNP) treatment on fluid distribution. The body fluid distribution of one subject was assessed before, during, and after weightlessness using two electrical impedance methods: (a) standard quadripole impedance for the segments of upper torso, lower torso, thigh, and calf and (b) an electrical impedance tomography technique (applied potential tomography) for a thigh cross-section...
September 1993: Clinical Investigator
https://www.readbyqxmd.com/read/8171594/use-of-a-quadripole-magnet-significantly-improves-immunomagnetic-islet-purification
#16
J E Davies, G S Robertson, S Swift, J Chamberlain, P R Bell, R F James, N J London
No abstract text is available yet for this article.
April 1994: Transplantation Proceedings
https://www.readbyqxmd.com/read/7533957/optimization-of-the-magnetic-field-used-for-immunomagnetic-islet-purification
#17
COMPARATIVE STUDY
J E Davies, R F James, N J London, G S Robertson
Purification of islets based on the physical differences in density between exocrine and islet tissue reduces islet yields and remains one of the factors limiting islet transplantation. Immunomagnetic cell separation methods provide an attractive, highly specific alternative capable of rapid, gentle, high volume cell separation, but they require modification to be applied effectively to separation of the much larger tissue fragments involved in islet purification. In this study, mAb to rat exocrine tissue were coupled to 4...
March 15, 1995: Transplantation
https://www.readbyqxmd.com/read/4930412/dipole-quadripole-and-octapole-measurements-in-isolated-beating-heart-preparations
#18
F H Terry, D A Brody, C O Eddlemon, J W Cox, F W Keller, H A Phillips
No abstract text is available yet for this article.
March 1971: IEEE Transactions on Bio-medical Engineering
https://www.readbyqxmd.com/read/4858470/-quadripole-components-of-the-resected-heart
#19
S Majima, H Yamamoto, H Matsuo, K Shimomura, R Kato
No abstract text is available yet for this article.
February 1974: Nihon Rinsho. Japanese Journal of Clinical Medicine
https://www.readbyqxmd.com/read/926545/-study-of-a-multifield-equivalent-cardiac-generator
#20
B M Tsukerman, I A Toropchina
The electric field of the isolated dog heart immersed into a liquid volumetric conductor was subjected to a thorough investigation. Measurements and subsequent calculations showed that in precordial leads the quantitative description of the cardiac generator by a multipole equivalent generator of the 1st order (dipole) is rough approximation. Addition of a multipole component of the 2nd order (quadripole) to the equivalent generator increases but relatively little the accuracy of description. It is suggested that in this problem the multipole expansion proves to be a slowly convergent series...
July 1977: Kardiologiia
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