Abstract：
BACKGROUND:Neuroblastoma is the most common extracranial malignant solid tumor in children under 5 years and is characterized by a wide clinical and biological heterogeneity, from spontaneously regressive forms to cancers with a rapid and fatal progression. MYCN oncogene amplification is considered the most important prognostic factor to evaluate survival and therapeutic choices in these patients. METHODS:Here we present a new assay for rapid and accurate measurement of MYCN amplification, based on real-time quantitative PCR with the TaqMan(TM) reaction. The degree of MYCN amplification was derived from the ratio of the MYCN oncogene and the single-copy reference gene, beta-actin. The absolute abundance of these two genes in tumor sample DNA was obtained by extrapolation on external calibration curves generated with reference DNA. RESULTS:We found a variable degree of MYCN amplification, from 2 to 29, in 26 of 49 (53%) neuroblastomas. These results were well correlated to those obtained with a competitive PCR assay in the same samples (r = 0. 987). MYCN amplification was associated mainly with advanced cancer stages, and the analysis of overall survival confirmed that the measurement of MYCN amplification is a predictor of patient outcome in neuroblastoma. Patients without MYCN amplification had a cumulative survival significantly higher than patients with low (<9; P = 0.02) and high (>/=9; P = 0.03) oncogene amplification. CONCLUSION:The assay is rapid and reproducible and does not require any post-PCR analytical procedure.
journal_name
Clin Chemjournal_title
Clinical chemistryauthors
Raggi CC,Bagnoni ML,Tonini GP,Maggi M,Vona G,Pinzani P,Mazzocco K,De Bernardi B,Pazzagli M,Orlando Csubject
Has Abstractpub_date
1999-11-01 00:00:00pages
1918-24issue
11eissn
0009-9147issn
1530-8561journal_volume
45pub_type
杂志文章abstract：BACKGROUND:With the gradual reopening of economies and resumption of social life, robust surveillance mechanisms should be implemented to control the ongoing COVID-19 pandemic. Unlike RT-qPCR, SARS-CoV-2 whole genome sequencing (cWGS) has the added advantage of identifying cryptic origins of the virus, and the extent o...
journal_title：Clinical chemistry
pub_type： 杂志文章
doi：10.1093/clinchem/hvaa187
更新日期：2020-11-01 00:00:00
abstract：:As the clinical utility of glycated hemoglobin (gHb) measurement increases, so does the need for standardization of values between different methods and different laboratories. Using three different methods, we examined the feasibility of interlaboratory standardization of gHb measurement. A liquid-chromatographic (HP...
journal_title：Clinical chemistry
pub_type： 杂志文章
doi：
更新日期：1986-02-01 00:00:00
abstract：:We evaluated the new Greiner G-400 selective multichannel analyzer. Thirty different tests can be run in combination profile and single-test mode at a rate between 150 and 300 tests per hour. The new photometer allows kinetic and equilibrium (endpoint) measurements. The G-400 analyzer demonstrated excellent precision,...
journal_title：Clinical chemistry
pub_type： 杂志文章
doi：
更新日期：1985-02-01 00:00:00
abstract：:The Dutch Foundation for Quality Assessment in Clinical Chemistry (SKZL) is the professional organization that conducts external quality-assessment schemes in The Netherlands. However, such schemes in fact assess the performance of the internal quality-control systems of the participating laboratories. In this paper w...
journal_title：Clinical chemistry
pub_type： 杂志文章
doi：
更新日期：1991-07-01 00:00:00
abstract：:Total protein (TP), albumin (Alb), transferrin (TRF), retinol-binding protein (RPB), N-acetyl-beta-glucosaminidase (NAG), alanine aminopeptidase (AAP), gamma-glutamyltransferase (GGT), and creatinine (Cr) were measured in random (untimed) urine samples from 29 nonpregnant women and from pregnant subjects (11 in the fi...
journal_title：Clinical chemistry
pub_type： 杂志文章
doi：
更新日期：1989-09-01 00:00:00
abstract：:We compared the ionic activity of sodium, as measured with glass electrodes, with sodium concentration in 23 healthy persons, 15 persons with acute renal failure, and before and after dialysis in 46 patients with chronic renal failure. In healthy persons the mean (+/- SEM) sodium concentration was 139.1 +/- 0.6 mmol/L...
journal_title：Clinical chemistry
pub_type： 杂志文章
doi：
更新日期：1985-11-01 00:00:00
abstract：:We compared three radioligands for use in a cytoplasmic estrogen-receptor assay, using pooled cytosol from human breast adenocarcinomas. The estrogen receptor content was determined in vitro by a dextran-coated charcoal method involving a 4-h incubation with and without diethylstilbestrol. Tritiated moxestrol failed t...
journal_title：Clinical chemistry
pub_type： 杂志文章
doi：
更新日期：1982-03-01 00:00:00
abstract：:A recently introduced automated nephelometric immunoassay involving shell/core particles for determination of myoglobin (Behringwerke) was evaluated with the BNA Nephelometer. Method precision was good: the intra-assay CV varied between 1.5% and 6.1%; with daily calibration, the interassay CV ranged between 1.5% and 7...
journal_title：Clinical chemistry
pub_type： 杂志文章
doi：
更新日期：1990-09-01 00:00:00
abstract：BACKGROUND:Concentrations of physiological response variables fluctuate over time. The present study describes within-day and seasonal fluctuations for total cholesterol, dehydroepiandrosterone sulfate (DHEA-S), hemoglobin A(1c) (HbA(1c)), IgA, prolactin, and free testosterone in blood, and estimates within- (CV(i)) an...
journal_title：Clinical chemistry
pub_type： 杂志文章
doi：
更新日期：2000-04-01 00:00:00
abstract：:A simple and convenient method using commercially available derivatization reagents is described for the measurement of betaine and N,N-dimethylglycine (DMG) in blood and urine. Precolumn derivatization of plasma or urine is performed directly in acetonitrile without extraction with p-bromophenacyl bromide and crown e...
journal_title：Clinical chemistry
pub_type： 杂志文章
doi：
更新日期：1998-09-01 00:00:00
abstract：BACKGROUND:Dopa-responsive dystonia (DRD) and tetrahydrobiopterin (BH4) defects are inherited disorders characterized by monoamine neurotransmitter deficiency with decreased activity of one of the BH4-metabolizing enzymes. The aim of the study was to determine the utility of cultured skin fibroblasts for the diagnosis ...
journal_title：Clinical chemistry
pub_type： 杂志文章
doi：
更新日期：2001-03-01 00:00:00
abstract：BACKGROUND:Non-(1-84) parathyroid hormone (PTH) fragments are large C-terminal fragments of PTH with a partially preserved N-terminal structure. They differ from other C-terminal PTH fragments, which do not have an N-terminal structure and do not react in intact PTH assays. We aimed to identify the minimal N-terminal s...
journal_title：Clinical chemistry
pub_type： 杂志文章
doi：10.1373/clinchem.2004.040485
更新日期：2005-01-01 00:00:00
abstract：:In photometry, where both the product formed and one or several reactants absorb light at the same wavelength, the absorbance of the "blank" of the sample at the end of the reaction may be less than that measured at the beginning of the reaction, because of consumption of reactant(s). The blank correction factor for t...
journal_title：Clinical chemistry
pub_type： 杂志文章
doi：
更新日期：1985-03-01 00:00:00
abstract：BACKGROUND:The thiopurine S:-methyltransferase (TPMT) genetic polymorphism has a significant clinical impact on the toxicity of thiopurine drugs, which are used in the treatment of leukemia and as immunosuppressants. To date, 10 mutant alleles are known that are associated with intermediate or low TPMT activity. To fac...
journal_title：Clinical chemistry
pub_type： 杂志文章
doi：
更新日期：2001-03-01 00:00:00
abstract：:We describe a time-resolved immunofluorometric assay (IFMA) for corticotropin in unextracted human plasma, based on the use of two monoclonal antibodies: europium-labeled antibody 1A12 and antibody 2A3 coated onto microtiter wells. We compared the results of this assay with those of an immunoradiometric assay (IRMA) p...
journal_title：Clinical chemistry
pub_type： 杂志文章
doi：
更新日期：1987-10-01 00:00:00
abstract：BACKGROUND:Risk assessments of patients should be based on objective variables, such as biological markers that can be measured routinely. The acute response to stress causes the release of catecholamines from the adrenal medulla accompanied by chromogranin A (CGA). To date, no study has evaluated the prognostic value ...
journal_title：Clinical chemistry
pub_type： 杂志文章
doi：10.1373/clinchem.2007.102442
更新日期：2008-09-01 00:00:00
abstract：:Detection and characterization of small IgM paraproteins by immunoelectrophoresis are often difficult because of (a) slow diffusion of the macromolecular immunoglobulin, and (b) the obscuring of the light chain, especially kappa, by the light chains of background polyclonal immunoglobulin (the "umbrella effect"). Vari...
journal_title：Clinical chemistry
pub_type： 杂志文章
doi：
更新日期：1988-08-01 00:00:00
abstract：:Creatine kinase isoenzyme BB (CK-BB) is found in the serum of patients with various types of cancer. Using both radioimmunoassay and agarose electrophoresis, we found abnormal amounts of this isoenzyme in the serum of 15 of 17 patients with untreated prostatic carcinoma. Among patients with other types of adenocarcino...
journal_title：Clinical chemistry
pub_type： 杂志文章
doi：
更新日期：1979-08-01 00:00:00
abstract：BACKGROUND:Iron may promote coronary atherosclerotic disease (CAD) by increasing lipid peroxidation. Studies on biochemical or genetic markers of body iron stores as risk factors for CAD have yielded conflicting results. METHODS:We studied 849 individuals with a clear-cut definition of the CAD phenotype, i.e., with (C...
journal_title：Clinical chemistry
pub_type： 杂志文章
doi：
更新日期：2002-01-01 00:00:00
abstract：BACKGROUND:Plasma creatinine concentration and calculated creatinine clearance are of limited value as glomerular filtration rate (GFR) markers in patients with decompensated liver cirrhosis. We assessed plasma cystatin C as an indicator of GFR in such patients. METHODS:We studied 36 patients with decompensated liver ...
journal_title：Clinical chemistry
pub_type： 杂志文章
doi：
更新日期：2002-06-01 00:00:00
abstract：:To evaluate a theoretical model for calculating free thyroid hormones, based on the law of mass action, we compared values for both calculated and measured free thyroxin and free triiodothyronine in a group of normal subjects. To determine whether the concentrations of circulating free hormones were also predictable f...
journal_title：Clinical chemistry
pub_type： 杂志文章
doi：
更新日期：1982-06-01 00:00:00
abstract：BACKGROUND:Recurrent pregnancy loss, (RPL) affecting 1%-2% of couples, is defined as ≥3 consecutive pregnancy losses before 20-week' gestation. Women with RPL are routinely screened for etiological factors, but routine screening of male partners is not currently recommended. Recently it has been suggested that sperm qu...
journal_title：Clinical chemistry
pub_type： 杂志文章
doi：10.1373/clinchem.2018.289348
更新日期：2019-01-01 00:00:00
abstract：BACKGROUND:Plasma concentrations of small dense (sd)-LDL are associated with the prevalence of cardiovascular events. However, the special equipment and long assay times required for sd-LDL measurement have hindered its clinical application. Herein, we report development of a simple homogeneous assay for sd-LDL-cholest...
journal_title：Clinical chemistry
pub_type： 杂志文章
doi：10.1373/clinchem.2010.149559
更新日期：2011-01-01 00:00:00
abstract：:Cholinesterase activity in human serum was measured calorimetrically and compared to values obtained with the spectrophotometric method of Rappaport et al. [Clin. Chim. Acta 4, 227 (1959)]. The response of the calorimeter upon mixing serum with acetylcholine corresponded to the cholinesterase activity of the serum, th...
journal_title：Clinical chemistry
pub_type： 杂志文章
doi：
更新日期：1977-10-01 00:00:00
abstract：BACKGROUND:The American Diabetes Association task force on standardization of insulin assays in 1996 showed wide variation in assay bias. Newer assays are specific for insulin, with several now available on automated immunoassay analyzers. METHODS:In 2004, we compared 11 commercially available insulin assays by analyz...
journal_title：Clinical chemistry
pub_type： 杂志文章,多中心研究
doi：10.1373/clinchem.2006.077784
更新日期：2007-05-01 00:00:00
abstract：:We developed a new colorimetric method, DNA enzyme immunoassay (DEIA), for detecting specific hybrids of complementary nucleic acids and applied it to the detection of hepatitis B virus (HBV) DNA amplified from serum samples by means of the polymerase chain reaction (PCR) technique. The method is based on the ability ...
journal_title：Clinical chemistry
pub_type： 杂志文章
doi：
更新日期：1991-03-01 00:00:00
abstract：:Seeking to minimize degradation of NADPH during storage, reagent preparation, and assays, we investigated the effects of pH, temperature, and ionic strength as well as the effects of phosphate and acetate. NADH was also included for comparison. Our results indicate that the rate of degradation of NADPH is proportional...
journal_title：Clinical chemistry
pub_type： 杂志文章
doi：
更新日期：1986-02-01 00:00:00
abstract：:We report the results of a laboratory and clinical evaluation of a commercial kit procedure (Immuno Nuclear Corp.) for measuring the mid-region of the parathyrin molecule. The estimated dose at 50% binding averaged 130 pmol/L, and the minimum detectable concentration was 14 pmol/L. The within-assay CV was less than or...
journal_title：Clinical chemistry
pub_type： 杂志文章
doi：
更新日期：1986-11-01 00:00:00
abstract：BACKGROUND:Increasing numbers of patients are presenting worldwide to emergency departments with suspected myocardial infarction. The use of point-of-care troponin assays might enable faster decision-making in this high-risk population and reduce the burden on emergency facilities. Here, we evaluate the diagnostic perf...
journal_title：Clinical chemistry
pub_type： 杂志文章
doi：10.1373/clinchem.2019.307405
更新日期：2019-12-01 00:00:00
abstract：:I describe a gas-chromatographic procedure involving a nitrogen detector for "free" (or "unbound") phenytoin in the concentration range 0.2-4.0 mg/L in ultrafiltrates of plasma. The CV (n = 10) for the assay was 2.9% for a 0.49 mg/L concentration, 1.5% for 2.02 mg/L. The sensitivity was 0.05 mg/L. The ultrafiltration ...
journal_title：Clinical chemistry
pub_type： 杂志文章
doi：
更新日期：1981-03-01 00:00:00
