Search results for "Reference Standards"
showing 10 items of 156 documents
Echocardiographic reference ranges for normal left atrial function parameters results from the EACVI NORRE study
2018
International audience; Aims - To obtain the normal ranges for echocardiographic measurements of left atrial (LA) function from a large group of healthy volunteers accounting for age and gender. Methods and results - A total of 371 (median age 45 years) healthy subjects were enrolled at 22 collaborating institutions collaborating in the Normal Reference Ranges for Echocardiography (NORRE) study of the European Association of Cardiovascular Imaging (EACVI). Left atrial data sets were analysed with a vendor-independent software (VIS) package allowing homogeneous measurements irrespective of the echocardiographic equipment used to acquire data sets. The lowest expected values of LA function we…
European Sero-Epidemiology Network: standardisation of the assay results for pertussis
2003
A standardisation process was developed in order to compare and harmonize serological results of pertussis toxin (PT) antibody measurements performed by laboratories using different technical procedures for detection. This involved the development of a common panel, of sera by a designed reference centre, the distribution of the panel to each participating laboratory for testing with their routine methods, the comparison of the obtained results to those of the reference centre, and the calculation of standardisation equations by regressing the quantitative results against those of the reference centre. As a cut-off indicative of protection against pertussis has not yet been defined, a parti…
The old and new tests for celiac disease: which is the best test combination to diagnose celiac disease in pediatric patients?
2011
BACKGROUND In the diagnosis of celiac disease (CD), serum assays for anti-endomysium (EMA) and anti-transglutaminase (anti-tTG) antibodies have excellent diagnostic accuracy. However, these assays are less sensitive in young pediatric patients. Recently, a new ELISA test using deamidated gliadin peptides (DGP) as antigen has proved to be very sensitive and specific even in pediatric patients. In addition, anti-actin IgA antibodies (AAA) is another test that can be used in CD patients because antibody concentrations correlate with the degree of villous atrophy. This study evaluated the clinical accuracy of anti-tTG, EMA, AGA, anti-DGP and AAA and the effectiveness of these in different combi…
MRI as the new reference standard in quantifying liver steatosis: the need for international guidelines.
2012
We read with great interest the paper by Raptis et al 1 regarding the quantification of liver steatosis by chemical-shift MRI. Chemical-shift imaging takes advantage of the difference in resonance frequency between water and fat (more precisely methylene, the most abundant group in triglycerides) to differentiate them. The dual-echo (in-phase/out-of-phase) MR technique used by the authors and derived from one of their previously published papers2 neglects T2* decay and assumes that the signal difference is due to fat–water interference alone.3 Yet, liver iron …
Recommendations for standardization and phenotype definitions in genetic studies of osteoarthritis: the TREAT-OA consortium
2011
Objective: To address the need for standardization of osteoarthritis (OA) phenotypes by examining the effect of heterogeneity among symptomatic (SOA) and radiographic osteoarthritis (ROA) phenotypes. Methods: Descriptions of OA phenotypes of the 28 studies involved in the TREAT-OA consortium were collected. We investigated whether different OA definitions result in different association results by creating various hip OA definitions in one large population based cohort (the Rotterdam Study I (RSI)) and testing those for association with gender, age and body mass index using one-way ANOVA. For ROA, we standardized the hip-, knee- and hand ROA definitions and calculated prevalence's of RO…
Gut and microbial resveratrol metabolite profiling after moderate long-term consumption of red wine versus dealcoholized red wine in humans by an opt…
2012
Resveratrol exerts a variety of biological and pharmacological activities, which are observed despite its extremely low bioavailability and rapid clearance from the circulation due to extensive sulfation and glucuronidation in the intestine and liver. In order to more accurately quantify all known resveratrol metabolites, a sensitive and optimized analytical assay was developed and validated by pure standards. Methodology improvements aimed to the chromatographic detection of disulfates and sulfoglucuronides, improving resolution of sulfates, by using a buffered solution, with recovery values of resveratrol and its metabolites, even of sulfates, of 99%. The adapted methodology was then appl…
1H and 13C NMR signal assignment of synthetic (-)-methyl thyrsiflorin B acetate, (-)-thyrsiflorin C and several scopadulane derivatives.
2005
The 1H and 13C NMR signal assignment of the data of 13 scopadulane-type diterpenes is reported. It was based on one- and two- dimensional NMR techniques which included 1H, 13C, DEPT, HMQC and 1D NOE difference spectroscopy. Copyright © 2005 John Wiley & Sons, Ltd.
Fluconazole susceptibility of Italian Candida dabliniensis clinical isolates determined by reference and simplified tests
2001
Candida dubliniensis ia an opportunistic pathogen mainly associated with oral candidiasis in human immunodeficiency virus (HIV)-infected individuals. We recently recovered the first Italian clinical isolates of C. dubliniensis from the oral cavities of seven HIV-seropositive subjects. The in vitro susceptibility to fluconazole (FLCZ) of these isolates was determined according to the National Committee for Clinical Laboratory Standards (NCCLS) M27-A broth microdilution method for yeasts. All seven isolates of C. dubliniensis were susceptible to FLCZ (MICs < or =0.5 microg/ml). Results of this reference method were compared to those obtained with simplified tests, more adapted to routine eval…
Análisis de resultados del Programa Externo de Control de Calidad SEIMC. Año 2013
2015
Resumen El Programa de Control de Calidad Externo de la Sociedad Espanola de Enfermedades Infecciosas y Microbiologia Clinica incluye las areas de bacteriologia trimestral y mensual, serologia, micologia, parasitologia, micobacterias, virologia, microbiologia molecular y cargas virales del virus de la inmunodeficiencia humana-1, virus de la hepatitis C y virus de la hepatitis B. En este manuscrito se presenta el analisis de los resultados remitidos por los participantes en los controles enviados durante el ano 2013, exceptuando los correspondientes a cargas virales, que se presentan en un manuscrito aparte. Los resultados obtenidos confirman de nuevo la buena capacitacion general de los lab…
Characterization and multicentric validation of a common standard for Toxoplasma gondii detection using nucleic acid amplification assays.
2014
ABSTRACT The molecular diagnosis of toxoplasmosis essentially relies upon laboratory-developed methods and suffers from lack of standardization, hence the large diversity of performances between laboratories. Moreover, quantifications of parasitic loads differ among centers, a fact which prevents the possible prediction of the severity of this disease as a function of parasitic loads. The objectives of this multicentric study performed in eight proficient laboratories of the Molecular Biology Pole of the French National Reference Center for Toxoplasmosis (NRC-T) were (i) to assess the suitability of a lyophilized preparation of Toxoplasma gondii as a common standard for use in this PCR-base…