			Home About us Contact

Delta Values (delta + value)

Distribution by Scientific Domains

Life Sciences	27%
Medical Sciences	18%
Earth and Environmental Science	18%

Selected Abstracts

Evaluation of a new, fully automated immunoassay for detection of HTLV-I and HTLV-II antibodies

JOURNAL OF MEDICAL VIROLOGY, Issue 3 2008
Xiaoxing Qiu
Abstract Screening blood donations for human T-lymphotropic virus types I and II (HTLV-I/II) continues to be important in protecting the safety of blood products and controlling the global spread of these retroviruses. We have developed a fully automated, third generation chemiluminescent immunoassay, ARCHITECT rHTLV-I/II, for detection of antibodies to HTLV-I/II. The assay utilizes recombinant proteins and synthetic peptides and is configured in a double antigen sandwich assay format. Specificity of the assay was 99.98% (9,254/9,256, 95% CI,=,99.92,100%) with the negative specimens from the general population including blood donors, hospital patients and pregnant women from the US, Japan and Nicaragua. The assay demonstrated 100% sensitivity by detecting 498 specimens from individuals infected with HTLV-I (n,=,385) and HTLV-II (n,=,113). ARCHITECT rHTLV-I/II results were in complete agreement with the Murex HTLV-I/II reference assay and 99.7% agreement with the Genelabs HTLV Blot 2.4 confirmatory assay. Analytical sensitivity of the assay was equivalent to Murex HTLV-I/II assay based on end point dilutions. Furthermore, using a panel of 397 specimens from Japan, the ARCHITECT rHTLV-I/II assay exhibited distinct discrimination between the antibody negative (Delta Value,=,,7.6) and positive (Delta Value,=,7.6) populations. Based on the excellent specificity and sensitivity, the new ARCHITECT rHTLV-I/II assay should be an effective test for the diagnosis of HTLV-I/II infection and also for blood donor screening. J. Med. Virol. 80:484,493, 2008. © 2008 Wiley-Liss, Inc. [source]

Three Secondary Reference Materials for Lithium Isotope Measurements: Li7-N, Li6-N and LiCl-N Solutions

GEOSTANDARDS & GEOANALYTICAL RESEARCH, Issue 1 2007
Jean Carignan
matériaux de référence; isotopes de Li; solutions de Li; QUAD-ICP-MS; MC-ICP-MS The CRPG (Nancy, France) has prepared secondary reference materials for Li isotope measurements by mixing 7Li or 6Li spikes and either L-SVEC or IRMM-016 certified reference materials to produce solutions having a known Li concentration and isotopic composition. The Li7-N and Li6-N solution samples (1.5 mol l,1 HNO3) have nominal ,7Li isotopic compositions of 30.1, and -9.7, respectively relative to L-SVEC and concentrations of 100 mg l,1. Repeated measurement of these samples using the QUAD-ICP-MS at the CRPG yielded ,7Li of 30.4 ± 1.1, (n = 13) and -8.9 ± 0.9, (n = 9) at the 2s level of confidence. An additional LiCl-N solution was measured and yielded a delta value of 9.5 ± 0.6, (n = 3). Identical results were obtained at the BRGM (Orléans, France) from determinations performed with a Neptune MC-ICP-MS (30.2 ± 0.3,, n = 89 for the Li7-N, -8.0 ± 0.3,, n = 38 for the Li6-N and 10.1 ± 0.2,, n = 46 for LiCl-N at the 2s level of confidence). The deviation of measured composition relative to the nominal value for the Li6-N solution might be explained by either contamination during preparation or an error during sample weighing. These secondary reference materials, previously passed through ion exchange resin or directly analysed, may be used for checking the accuracy of Li isotopic measurements over a range of almost 40, and will be available to the scientific community upon request to J. Carignan or N. Vigier, CRPG. Le CRPG (Nancy, France) a préparé des matériaux secondaires de référence pour l'analyse des isotopes du Li en mélangeant des spikes de 7Li ou 6Li avec les matériaux de référence certifiés L-SVEC ou IRMM-016, ceci afin de produire des solutions ayant des concentrations et compositions isotopiques de Li connues. Les solutions Li7-N et Li6-N (1.5 mol l,1 HNO3) ont des compositions isotopiques nominales de ,7Li, exprimées par rapport à L-SVEC, de 30.1, et de -9.7, respectivement, et des concentrations de 10 0 mg l,1. L'analyse répétée de ces solutions par QUAD-ICP-MS au CRPG donne des ,7Li de 30.4 ± 1.1, (n = 13) et -8.9 ± 0.9, (n = 9) avec une incertitude à 2s. Une solution additionnelle de LiCl-N a été analysée et a donné une valeur de delta de 9.5 ± 0.6, (n = 3). Des résultats identiques ont été obtenus au BRGM (Orléans, France) où les déterminations ont été effectuées sur le MC-ICP-MS Neptune (30.2 ± 0.3,, n = 89 pour Li7-N, -8.0 ± 0.3,, n = 38 pour Li6-N et 10.1 ± 0.2,, n = 46 pour LiCl-N, à 2s d'intervalle de confiance). Le biais entre les compositions mesurées et la valeur nominale, observé pour la solution Li6-N peut être expliqué par une contamination durant la préparation ou par une erreur durant la pesée. Ces matériaux secondaires de référence, préalablement passés sur résine échangeuse d'ions ou analysés directement, peuvent être utilisés pour vérifier la justesse des analyses isotopiques de Li sur une gamme de presque 40% et sont à la disposition de la communauté scientifique sur demande auprès de J. Carignan ou N. Vigier, CRPG. [source]

Changes in the natural abundance of 13CO2/12CO2 in breath due to lipopolysacchride-induced acute phase response

RAPID COMMUNICATIONS IN MASS SPECTROMETRY, Issue 23 2009
Daniel E. Butz
The natural abundance of carbon-13 in blood proteins increases during the cachectic state and may be a biomarker for disease status. We hypothesized a corresponding drop in the relative abundance of 13C in breath CO2. Using the lipopolysacchride (LPS)-induced endotoxemia model of the acute cachectic state, we demonstrated that the acute phase response causes shifts in the stable isotopes of carbon in exhaled CO2 (13CO2/12CO2 delta value) shortly after administration of LPS while glucocorticoid treatment does not. Mice were injected with LPS and stable isotopes of blood amino acids and carbon in exhaled CO2 were monitored. An increase in the relative isotopic mass of serum alanine, proline and threonine was observed at 3,h after LPS injection. Breath delta values began dropping immediately after administration of LPS, and were 4,5 delta values lower than those of the control animals by 2.5,h after injection. A corresponding drop in delta value was not observed with dexamethasone treatment. Thus protein synthesis during the acute phase response probably caused the fractionation of stable isotopes observed in the plasma amino acids and in exhaled breath 13CO2 delta values. The exhaled breath 13CO2 delta value may be a valuable real-time biomarker of cachexia associated with an acute phase response due to endotoxemia. Copyright © 2009 John Wiley & Sons, Ltd. [source]

Golimumab, a human anti,tumor necrosis factor , monoclonal antibody, injected subcutaneously every four weeks in methotrexate-naive patients with active rheumatoid arthritis: Twenty-four,week results of a phase III, multicenter, randomized, double-blind, placebo-controlled study of golimumab before methotrexate as first-line therapy for early-onset rheumatoid arthritis,

ARTHRITIS & RHEUMATISM, Issue 8 2009
Paul Emery
Objective To assess the safety and efficacy of golimumab in methotrexate (MTX),naive patients with active rheumatoid arthritis (RA). Methods MTX-naive patients with RA (n = 637) were randomized to receive placebo plus MTX (group 1), golimumab 100 mg plus placebo (group 2), golimumab 50 mg plus MTX (group 3), or golimumab 100 mg plus MTX (group 4). Subcutaneous injections of golimumab or placebo were administered every 4 weeks. The dosage of MTX/placebo capsules started at 10 mg/week and escalated to 20 mg/week. The primary end point, the proportion of patients meeting the American College of Rheumatology 50% improvement criteria (achieving an ACR50 response) at week 24, required significant differences between groups 3 and 4 combined (combined group) versus group 1 and significant differences in a pairwise comparison (group 3 or group 4 versus group 1). Results An intent-to-treat (ITT) analysis of the ACR50 response at week 24 did not show a significant difference between the combined group and group 1 (38.4% and 29.4%, respectively; P = 0.053), while a post hoc modified ITT analysis (excluding 3 untreated patients) of the ACR50 response showed statistically significant differences between the combined group and group 1 (38.5% versus 29.4%; P = 0.049) and between group 3 (40.5%; P = 0.038) but not group 4 (36.5%; P = 0.177) and group 1. Group 2 was noninferior to group 1 for the ACR50 response at week 24 (33.1%; 95% confidence interval lower bound ,5.2%; predefined delta value for noninferiority ,10%). The combination of golimumab plus MTX demonstrated a significantly better response compared with placebo plus MTX in most other efficacy parameters, including response/remission according to the Disease Activity Score in 28 joints. Serious adverse events occurred in 7%, 3%, 6%, and 6% of patients in groups 1, 2, 3, and 4, respectively. Conclusion Although the primary end point was not met, the modified ITT analysis of the primary end point and other prespecified efficacy measures demonstrated that the efficacy of golimumab plus MTX is better than, and the efficacy of golimumab alone is similar to, the efficacy of MTX alone in reducing RA signs and symptoms in MTX-naive patients, with no unexpected safety concerns. [source]

The Influence of Lactobacillus brevis on Ornithine Decarboxylase Activity and Polyamine Profiles in Helicobacter pylori -Infected Gastric Mucosa

HELICOBACTER, Issue 2 2004
Michele Linsalata
ABSTRACT Background., Functional probiotics may prevent Helicobacter pylori infection, and some evidence suggests that they also possess antitumor properties. Lactobacillus brevis (CD2) is a functional Lactobacillus strain with peculiar biochemical features, essentially related to the activity of arginine deiminase. This enzyme catalyzes the catabolism of arginine and affects the biosynthesis of polyamines (putrescine, spermidine, and spermine). Polyamines are polycations found in high concentrations in both normal and neoplastic cells. Our aims were: 1, to assess whether oral administration of L. brevis (CD2) affects H. pylori survival in the human gastric mucosa; 2, to evaluate the effects of L. brevis (CD2) on polyamine biosynthesis in gastric biopsies from H. pylori- positive patients. Materials and Methods., For 3 weeks before endoscopy, 22 H. pylori- positive dyspeptic patients randomly received (ratio 1 : 1) high oral doses of L. brevis (CD2) or placebo. Before and after treatment, H. pylori infection was determined by urea breath test (UBT). In gastric biopsies, ornithine decarboxylase activity and polyamine levels were, respectively, evaluated by a radiometric technique and high-pressure liquid chromatography (HPLC). Results.,L. brevis (CD2) treatment did not eradicate H. pylori. However, a reduction in the UBT delta values occurred, suggesting a decrease in intragastric bacterial load. Significantly, L. brevis (CD2) induced a decrease in gastric ornithine decarboxylase activity and polyamine levels. Conclusions., Our data support the hypothesis that L. brevis (CD2) treatment decreases H. pylori colonization, thus reducing polyamine biosynthesis. Alternatively, the arginine deiminase activity following L. brevis (CD2) administration might cause arginine deficiency, preventing polyamine generation from gastric cells. [source]

A comparison of cyclic variations in anterior knee laxity, genu recurvatum, and general joint laxity across the menstrual cycle

JOURNAL OF ORTHOPAEDIC RESEARCH, Issue 11 2010
Sandra J. Shultz
Abstract Changes in anterior knee laxity (AKL), genu recurvatum (GR) and general joint laxity (GJL) were quantified across days of the early follicular and early luteal phases of the menstrual cycle in 66 females, and the similarity in their pattern of cyclic variations examined. Laxity was measured on each of the first 6 days of menses (M1,M6) and the first 8 days following ovulation (L1,L8) over two cycles. The largest mean differences were observed between L5 and L8 for AKL (0.32,mm), and between L5 and M1 for GR (0.56°) and GJL (0.26) (p,<,0.013). At the individual level, mean absolute cyclic changes in AKL (1.8,±,0.7,mm, 1.6,±,0.7,mm), GR (2.8,±,1.0°, 2.4,±,1.0°), and GJL (1.1,±,1.1, 0.7,±,1.0) were more apparent, with minimum, maximum and delta values being quite consistent from month to month (ICC2,3,=,0.51,0.98). Although the average daily pattern of change in laxity was quite similar between variables (Spearman correlation range 0.61 and 0.90), correlations between laxity measures at the individual level were much lower (range ,0.07 to 0.43). Substantial, similar, and reproducible cyclic changes in AKL, GR, and GJL were observed across the menstrual cycle, with the magnitude and pattern of cyclic changes varying considerably among females. © 2010 Orthopaedic Research Society. Published by Wiley Periodicals, Inc. J Orthop Res 28:1411,1417, 2010 [source]

The influence of maternal insulin-dependent diabetes on fetal nuchal translucency thickness and first-trimester maternal serum biochemical markers of aneuploidy

PRENATAL DIAGNOSIS, Issue 10 2005
Kevin Spencer
Abstract Objective To evaluate the influence of maternal insulin dependent diabetes mellitus (IDDM) on maternal serum free ,-hCG, PAPP-A and fetal nuchal translucency (NT), thickness at 11 to 13+6 weeks of gestation in a large cohort of women screened prospectively for chromosomal anomalies. Methods Information on maternal IDDM status, maternal serum biochemical marker levels and fetal NT were collected from the prenatal screening computer records in two first-trimester screening centres. In total the control group included 33 301 pregnancies of which 16 366 had NT and maternal serum biochemistry results and 16 305 with NT only. The IDDM group included 195 pregnancies of which 79 had NT and maternal serum biochemistry results and 127 with NT only. The median maternal weight corrected free ,-hCG and PAPP-A, expressed as multiple of the median (MoM), and fetal NT, expressed as delta values, in the IDDM and non-IDDM groups were compared. Results There were no significant differences between the IDDM and non-IDDM groups in median maternal weight corrected free ,-hCG (IDDM 0.87 MoM, 95% Confidence Interval 0.75 to 1.16 MoM, non-IDDM 1.00 MoM), median maternal weight corrected PAPP-A (IDDM 1.02 MoM, 95% Confidence Interval 0.83 to 1.05 MoM, non-IDDM 1.01 MoM), or mean delta NT (IDDM 0.0358 mm, non-IDDM 0.0002 mm). Conclusions In pregnancies with maternal IDDM, first-trimester screening for chromosomal defects does not require adjustments for the measured fetal NT. However, more data are required before the possible reduction in maternal serum free ,-hCG and the reduction of PAPP-A suggested by the published world series can be considered sufficiently important to take into account in the calculation of risks for chromosomal defects. Copyright © 2005 John Wiley & Sons, Ltd. [source]

Changes in the natural abundance of 13CO2/12CO2 in breath due to lipopolysacchride-induced acute phase response

Detection of royal jelly adulteration using carbon and nitrogen stable isotope ratio analysis

RAPID COMMUNICATIONS IN MASS SPECTROMETRY, Issue 2 2006
A. Stocker
Stable isotope ratios (13C/12C and 15N/14N) were measured in royal jelly (RJ) samples by isotope ratio mass spectrometry (IRMS) to evaluate authenticity and adulteration. Carbon and nitrogen isotope contents (given as delta values relative to a standard, ,13C, ,15N) of RJ samples from various European origins and samples from commercial sources were analyzed. Uniform ,13C values from ,26.7 to ,24.9, were observed for authentic RJ from European origins. Values of ,15N ranged from ,1.1 to 5.8, depending on the plant sources of nectars and pollen. High ,13C values of several commercial RJ samples from ,20.8 to ,13.3, indicated adulteration with high fructose corn syrup (HFCS) as a sugar source. Use of biotechnologically produced yeast powder as protein source for the adulterated samples was assumed as ,15N values were lower, as described for C4 or CAM plant sources. RJ samples from authentic and from adulterated production were distinguished. The rapid and reliable method is suitable for urgent actual requirements in food monitoring. Copyright © 2005 John Wiley & Sons, Ltd. [source]

Natural abundance of 15N and 13C in fish tissues and the use of stable isotopes as dietary protein tracers in rainbow trout and gilthead sea bream

AQUACULTURE NUTRITION, Issue 1 2009
M. BELTRÁN
Abstract For developing efficient diets, two sets of experiments examined whether the use and allocation of dietary protein can be traced by labelling with stable isotopes (15N and 13C) in two culture fish (Oncorhynchus mykiss and Sparus aurata). In the first experiment, natural abundance and tissue distribution of these isotopes were determined, by measuring the ,13C and ,15N values by isotopic ratio mass spectrometry, in fingerlings (14,17 g) adapted to diets differing in the percentage of fish meal replacement by plant protein sources. For both species, ,15N and ,13C were greater in tissues with higher protein and lower lipid content. Delta 15N of diets and tissues decreased as replacement increased, suggesting ,15N can be used as a marker for dietary protein origin. The 15N fractionation (,15N fish , ,15N diet) differed between groups, and could thus be used to indicate protein catabolism. In the second experiment, fish (75,90 g) of each species ingested a diet enriched with 15N-protein (10 g kg,1 diet) and 13C-protein (30 g kg,1 diet). These proportions were suitable for determining that the delta values of tissue components were high enough above natural levels to allow protein allocation to be traced at 11 and 24 h after feeding, and revealed clear metabolic differences between species. [source]