410 research outputs found
Evaluation of the first automated thyroglobulin assay
The aim of this study was to investigate technical and analytical performance of the first automated thyroglobulin (Tg) assay (DPC-Immulite(R); Diagnostic Products Corporation, Los Angeles, USA). In imprecision studies using several human serum pools ranging from 21 to 58 replicates, a coefficient of variation of 9.0 % was obtained at a mean Tg concentration of 0.84 ng/ml and of 6.1 % at a Tg concentration of 62.1 ng/ml. In a method comparison with a non-automated assay (BRAHMS LUMItest Tg(R), BRAHMS, Berlin, Germany) using 383 sera of 303 patients with thyroid carcinoma, regression analysis according to Passing and Bablock yielded in the following equation: Immulite Tg=1.6 x BRAHMS Tg - 0.1 ng/ml (Pearson's r=0.979). Sera obtained from 59 patients with thyroid carcinoma enabled comparative follow-up studies; in all cases qualitative agreement was found with regard to increase or decrease of serum Tg; in eight cases, however, Tg was detected with the Immulite assay but not with the BRAHMS assay. Further follow-up proved the presence of thyroid tissue in these patients. From these and further methodological data (dilution linearity, interference studies, carry-over study, high-dose hook properties, and short report time) it is concluded that the DPC-Immulite Tg assay meets the requirements of routine diagnostic use
Comparison between BNP values measured in capillary blood samples with a POCT method and those measured in plasma venous samples with an automated platform
Letter to the Editor. Our data suggest that it is possible
to measure BNP in fresh finger-stick samples of capillary
whole blood with an acceptable reproducibility,
and within 10 â 20 min to obtain results close correlated
to those measured by the automated platform in plasma
blood samples collected from a vein. The measurement
of BNP in fresh finger-stick samples of capillary whole
blood with this POCT method is in particular indicated for
the management of HF patients at home and for the BNP
assay in neonates and children
State of the art of aldosterone immunoassays. A multicenter collaborative study on the behalf of the Cardiovascular Biomarkers Study Group of the Italian Section of European Society of Ligand Assay (ELAS) and SocietĂ Italiana di Biochimica Clinica (SIBIOC).
Background: Two newimmunoassay methods for aldosterone assay using automated platforms recently became
available into market. The main aim of the present study is to evaluate the analytical performance of these automated
direct immunoassay methods, and also to compare their analytical characteristics to those of the most
popular RIA and EIA methods used in an Italian External Quality Assessment (EQA) study.
Methods: In this study analytical performances of twoaldosterone immunoassays using the IDS iSYS and DiaSorin
LIAISON fully automated platforms, were evaluated. Results obtained with the two platforms in EDTA plasma
samples of healthy subjects and patients were compared with those obtained by RIA and EIA methods used in
the Italian EQA scheme, named Immunocheck study.
Results: The two automated methods showed similar analytical performances: LoD 83.9 vs 92.2 pmol/L, LoQ
104.4 vs 111.1 pmol/L, respectively; moreover, the within-run and total imprecision values showed CV%
between 8.1 and 14.1 for samples with 180.8 and 387.2 pmol/L concentration for both methods. There was a
close linear regression between methods, however we found a significant proportional bias between LIAISON
and iSYS methods. The EQA samples results obtainedwith these two methods were highly correlated to the consensus
mean values.
Conclusions: Our data indicate that aldosterone values measuredwith the two automated methods actually show
better reproducibility, shorter laboratory Turn Around Time (TAT) and require less âhands on laborâ compared to
RIA and EIA immunoassays. However, in our study significant biaswas observed in result comparison, this means
that translating aldosterone concentration in clinical information an appropriate definition of reference ranges
for each method is mandatory
Evaluation of analytical performance and comparison of clinical results of the new generation method AccuTnI+3 for the measurement of cardiac troponin I using both patients and quality control plasma samples
The study aims are to evaluate the analytical performance and the clinical results of the chemiluminescent Access
AccuTnI+3 immunoassay for the determination of cardiac troponin I (cTnI)with DxI 800 and Access2 platforms
and to compare the clinical results obtained with this method with those of three cTnI immunoassays, recently
introduced in the European market. The limits of blank (LoB), detection (LoD), and quantitation (LoQ) at 20%
CV and 10% CV were 4.5 ng/L and 10.9 ng/L, 17.1 and 30.4 ng/L, respectively. The results of STAT Architect high
Sensitive TnI (Abbott Diagnostics), ADVIA Centaur Troponin I Ultra (Siemens Healthcare Diagnostics), ST AIA-Pack
cTnI third generation (Tosoh Bioscience), and Access AccuTnI + 3 (Beckman Coulter Diagnostics) showed very
close correlations (R ranging from 0.901 to 0.994) in 122 samples of patients admitted to the emergency department.
However, on average there was a difference up to 2.4-fold between the method measuring the highest
(ADVIA method) and lowest cTnI values (AccuTnI + 3 method). The consensus mean values between methods
ranged from 6.2% to 29.6% in 18 quality control samples distributed in an external quality control study (cTnI
concentrations ranging from 29.3 ng/L to 1557.5 ng/L). In conclusion, the results of our analytical evaluation
concerning the AccuTnI + 3 method, using the DxI platform, are well in agreement with those suggested by the
manufacturer as well as those reported by some recent studies using the Access2 platform. Our results confirm
that the AccuTnI + 3 method for the Access2 and DxI 800 platforms is a clinically usable method for cTnI
measurement
State of the science on controversial topics: orthodontic therapy and gingival recession (a report of the Angle Society of Europe 2013 meeting).
BACKGROUND: Controversy exists in the literature between the role of orthodontic treatment and gingival recession. Whilst movement of teeth outside the alveolar bone has been reported as a risk factor for gingival recession, others have found no such association. FINDINGS: The Angle Society of Europe devoted a study day to explore the evidence surrounding these controversies. The aim of the day was for a panel of experts to evaluate the current evidence base in relation to either the beneficial or detrimental effects of orthodontic treatment on the gingival tissue. CONCLUSIONS: There remains a relatively weak evidence base for the role of orthodontic treatment and gingival recession and thus a need to undertake a risk assessment and appropriate consent prior to the commencement of treatment. In further prospective, well designed trials are needed
New physics searches at near detectors of neutrino oscillation experiments
We systematically investigate the prospects of testing new physics with tau
sensitive near detectors at neutrino oscillation facilities. For neutrino beams
from pion decay, from the decay of radiative ions, as well as from the decays
of muons in a storage ring at a neutrino factory, we discuss which effective
operators can lead to new physics effects. Furthermore, we discuss the present
bounds on such operators set by other experimental data currently available.
For operators with two leptons and two quarks we present the first complete
analysis including all relevant operators simultaneously and performing a
Markov Chain Monte Carlo fit to the data. We find that these effects can induce
tau neutrino appearance probabilities as large as O(10^{-4}), which are within
reach of forthcoming experiments. We highlight to which kind of new physics a
tau sensitive near detector would be most sensitive.Comment: 20 pages, 2 figures, REVTeX
Tumor markers in breast cancer - European Group on Tumor Markers recommendations
Recommendations are presented for the routine clinical use of serum and tissue-based markers in the diagnosis and management of patients with breast cancer. Their low sensitivity and specificity preclude the use of serum markers such as the MUC-1 mucin glycoproteins ( CA 15.3, BR 27.29) and carcinoembryonic antigen in the diagnosis of early breast cancer. However, serial measurement of these markers can result in the early detection of recurrent disease as well as indicate the efficacy of therapy. Of the tissue-based markers, measurement of estrogen and progesterone receptors is mandatory in the selection of patients for treatment with hormone therapy, while HER-2 is essential in selecting patients with advanced breast cancer for treatment with Herceptin ( trastuzumab). Urokinase plasminogen activator and plasminogen activator inhibitor 1 are recently validated prognostic markers for lymph node-negative breast cancer patients and thus may be of value in selecting node-negative patients that do not require adjuvant chemotherapy. Copyright (C) 2005 S. Karger AG, Basel
Search for supersymmetric particles in scenarios with a gravitino LSP and stau NLSP
Sleptons, neutralinos and charginos were searched for in the context of
scenarios where the lightest supersymmetric particle is the gravitino. It was
assumed that the stau is the next-to-lightest supersymmetric particle. Data
collected with the DELPHI detector at a centre-of-mass energy near 189 GeV were
analysed combining the methods developed in previous searches at lower
energies. No evidence for the production of these supersymmetric particles was
found. Hence, limits were derived at 95% confidence level.Comment: 31 pages, 14 figure
Measurement of the Bottom-Strange Meson Mixing Phase in the Full CDF Data Set
We report a measurement of the bottom-strange meson mixing phase \beta_s
using the time evolution of B0_s -> J/\psi (->\mu+\mu-) \phi (-> K+ K-) decays
in which the quark-flavor content of the bottom-strange meson is identified at
production. This measurement uses the full data set of proton-antiproton
collisions at sqrt(s)= 1.96 TeV collected by the Collider Detector experiment
at the Fermilab Tevatron, corresponding to 9.6 fb-1 of integrated luminosity.
We report confidence regions in the two-dimensional space of \beta_s and the
B0_s decay-width difference \Delta\Gamma_s, and measure \beta_s in [-\pi/2,
-1.51] U [-0.06, 0.30] U [1.26, \pi/2] at the 68% confidence level, in
agreement with the standard model expectation. Assuming the standard model
value of \beta_s, we also determine \Delta\Gamma_s = 0.068 +- 0.026 (stat) +-
0.009 (syst) ps-1 and the mean B0_s lifetime, \tau_s = 1.528 +- 0.019 (stat) +-
0.009 (syst) ps, which are consistent and competitive with determinations by
other experiments.Comment: 8 pages, 2 figures, Phys. Rev. Lett 109, 171802 (2012
- âŠ