Abstract：
BACKGROUND:Human chorionic gonadotropin (hCG) is a heterodimeric glycoprotein hormone that exists in multiple forms. Immunoassays commonly used in clinical laboratories measure intact hCG, total beta hCG (intact hCG + hCG free beta-subunit), and/or hCG free beta-subunit. Measurement of serum concentrations of hCG is useful for confirmation and monitoring of pregnancy, diagnosis of trophoblastic diseases and monitoring of the efficacy of treatment, and prenatal screening. Correctly reporting results for the various forms of hCG is clinically important. METHOD:We prepared samples by addition of intact hCG and hCG free beta-subunit to an essentially hCG-free human serum matrix. The samples were analyzed by participant laboratories using various immunoassay methods. RESULTS:We identified errors in participant reporting of intact hCG results as total beta hCG (9.3%; 22 of 235 laboratories) and total beta hCG as intact hCG (13.1%; 8 of 61 laboratories). CONCLUSIONS:Many factors contribute to the erroneous reporting of hCG results, including (a) the complexity of hCG molecule and confusion of nomenclature on the various forms of hCG; (b) laboratory personnel's lack of awareness of the distinctions of the forms of hCG and failure to recognize the specificity of assays for their measurement; (c) lack of clarity and uniformity in manufacturers' reagent labeling; and (d) most product inserts' lack of information on the specificity of each method to the various forms of hCG.
journal_name
Clin Chemjournal_title
Clinical chemistryauthors
Cao ZT,Rej Rdoi
10.1373/clinchem.2007.098822subject
Has Abstractpub_date
2008-04-01 00:00:00pages
761-4issue
4eissn
0009-9147issn
1530-8561pii
clinchem.2007.098822journal_volume
54pub_type
杂志文章abstract：:A rapid and precise immunoassay for quantification of total homocysteine in blood samples is presented. The method avoids the use of radioisotopes and chromatographic separations and relies on enzymatic conversion of homocysteine to S-adenosyl-L-homocysteine, followed by quantification of S-adenosyl-L-homocysteine by ...
journal_title：Clinical chemistry
pub_type： 杂志文章
doi：
更新日期：1998-02-01 00:00:00
abstract：:We detected increased concentrations of lipoperoxidation products, as malondialdehyde, in the serum of an infant with classic hemolytic-uremic syndrome. The concentrations declined when peritoneal dialysis was initiated and eventually returned to normal after clinical recovery. Our observation adds to the existing bod...
journal_title：Clinical chemistry
pub_type： 杂志文章
doi：
更新日期：1988-11-01 00:00:00
abstract：:A highly sensitive two-site enzyme immunoassay (Capcellia) was developed to determine the concentration of CD4 and CD8 molecules expressed on the surface of human T lymphocytes. This assay, performed in one step (20 min), involves the specific immunocapture of T lymphocytes and reaction of the CD4 or CD8 molecules wit...
journal_title：Clinical chemistry
pub_type： 杂志文章
doi：
更新日期：1994-01-01 00:00:00
abstract：:The Axial Separation Module (ASM), which separates whole-blood specimens serially in Axial Process Containers (APC), was evaluated for clinical performance at the University of Virginia Health Sciences Center (UVA HSC) in a community-based outpatient laboratory (North Ridge Clinic). We hypothesized that moving the tas...
journal_title：Clinical chemistry
pub_type： 杂志文章
doi：
更新日期：1997-02-01 00:00:00
abstract：:Estrogen receptor (ER) and progestin receptor (PR) concentrations in tumor biopsies are important predictive indicators of a clinical response to endocrine therapy of breast cancer. To assess interference of O.C.T. (optimum cutting temperature) embedding compound in assays of ER and PR by radioligand binding, we deter...
journal_title：Clinical chemistry
pub_type： 杂志文章
doi：
更新日期：1989-12-01 00:00:00
abstract：:We adapted the method of McCaman and Robins for fluorometry of phenylalanine to a microplate assay for routine phenylketonuria screening. Sensitivity is 15 mumol/L for the plasma assay and 30 mumol/L for the dried blood-spot assay, with CV less than 10% for both assays. Results for human plasma by microplate assay cor...
journal_title：Clinical chemistry
pub_type： 杂志文章
doi：
更新日期：1989-10-01 00:00:00
abstract：:We describe a solid-phase radioimmunometric sandwich assay for a new tumor marker defined by a monoclonal antibody (19-9). This antibody reacts with a carbohydrate antigenic determinant (CA 19-9) found at low concentrations in sera from healthy individuals but frequently increased in sera from patients with adenocarci...
journal_title：Clinical chemistry
pub_type： 杂志文章
doi：
更新日期：1983-03-01 00:00:00
abstract：BACKGROUND:Previous studies have shown a single linear relationship between mean plasma glucose (MPG) and hemoglobin A(1c) (HbA(1c)). We examined the relationship in different treatment groups of patients with type 1 diabetes participating in the Diabetes Control and Complications Trial (DCCT). METHODS:Seven-point glu...
journal_title：Clinical chemistry
pub_type： 杂志文章,随机对照试验
doi：10.1373/clinchem.2006.079756
更新日期：2007-05-01 00:00:00
abstract：:We assessed the performance of three commercially available polyclonal immunoassays for apparent cyclosporine in 120 whole-blood specimens collected from transplant recipients just before their next dose of cyclosporine (CsA). The assays were (a) Abbott's TDx fluorescent polarization immunoassay for CsA and its metabo...
journal_title：Clinical chemistry
pub_type： 杂志文章
doi：
更新日期：1990-01-01 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：:We evaluated the homogeneous enzyme immunoassay ("EMIT") of serum thyroxine with use of an ABA- 100 Bichromatic Analyzer, modified with an auxiliary dispenser syringe and a dual probe assembly. The modification allows two reagents to be dispensed at one time. The sera must be pre-treated with 0.1 mol/liter NaOH. The p...
journal_title：Clinical chemistry
pub_type： 杂志文章
doi：
更新日期：1978-01-01 00:00:00
abstract：:This simple polarization fluoroimmunoassay for detection of amphetamine in urine involves the use of a single reagent: suitably diluted antiserum plus fluorescein-labeled amphetamine as tracer. To this, one adds 10 microL of urine, incubates for a few minutes at room temperature, and measures the fluorescence polariza...
journal_title：Clinical chemistry
pub_type： 杂志文章
doi：
更新日期：1985-07-01 00:00:00
abstract：:We coupled a kinetic procedure to a selective inhibiting method for determining amylase isoenzymes in biological samples, using 4-nitrophenylmaltopentaoside plus 4-nitrophenylmaltohexaoside as substrate and a wheat-germ selective inhibitor with the Gilford S-III spectrophotometer. On plotting remaining amylase activit...
journal_title：Clinical chemistry
pub_type： 杂志文章
doi：
更新日期：1986-08-01 00:00:00
abstract：BACKGROUND:Growth differentiation factor 15 (GDF15), a stress-responsive cytokine produced in cardiovascular cells under conditions of inflammation and oxidative stress, is emerging as an important prognostic marker in individuals with and without existing cardiovascular disease (CVD). We therefore examined the clinica...
journal_title：Clinical chemistry
pub_type： 杂志文章,meta分析
doi：10.1373/clinchem.2012.190322
更新日期：2012-11-01 00:00:00
abstract：BACKGROUND:A simple point-of-care method for measuring leukocyte counts in a doctor's office or emergency room could be of great importance. We developed a protocol for measuring cell count by disrupting the cell membrane and analyzing specific proteins within the cells and used it to analyze proteins from eosinophils ...
journal_title：Clinical chemistry
pub_type： 杂志文章
doi：10.1373/clinchem.2006.074021
更新日期：2007-02-01 00:00:00
abstract：:To determine the molar absorptivities of beta-NADH and beta-NAD at 260 nm, we purified the reduced form of the coenzyme by repeated anion-exchange chromatography. A NADH preparation was so obtained for which the 260 nm/340 nm absorbance ratio was 2.265. When calculated with epsilon 340 beta-NADH = 6.22 times 10-3 for ...
journal_title：Clinical chemistry
pub_type： 杂志文章
doi：
更新日期：1975-06-01 00:00:00
abstract：:Even in the absence of detectable ethanol or visible lipemia, a large plasma osmolal gap is the usual finding in cases of diabetic ketoacidosis. This gap decreases to an insignificant value within 20 h of treatment. Detailed biochemical analysis of six cases showed that, on average, the gap could be almost wholly acco...
journal_title：Clinical chemistry
pub_type： 杂志文章
doi：
更新日期：1992-05-01 00:00:00
abstract：:The accuracy of estimates of blood-alcohol concentration based on measurements of breath-alcohol concentration in a randomly selected subject by a random quantitative evidential breath-alcohol analyzer is evaluated with respect to the breath analyzer itself, its calibration, and the biological variables of the subject...
journal_title：Clinical chemistry
pub_type： 杂志文章
doi：
更新日期：1987-02-01 00:00:00
abstract：BACKGROUND:The recent discovery of the presence of circulating cell-free fetal DNA in maternal plasma opens up new prenatal diagnostic applications and provides new avenues for clinical investigation. It is of research and potential diagnostic interest to determine whether fetal trisomy 21 may be associated with quanti...
journal_title：Clinical chemistry
pub_type： 临床试验,杂志文章,多中心研究
doi：
更新日期：1999-10-01 00:00:00
abstract：BACKGROUND:The kidney performs a multitude of essential functions to maintain homeostasis. In clinical medicine, glomerular filtration rate (GFR) provides the best index of overall kidney function, and proteinuria adds additional information on renal and nonrenal prognosis. Several novel biomarkers of kidney injury and...
journal_title：Clinical chemistry
pub_type： 杂志文章,评审
doi：10.1373/clinchem.2011.167494
更新日期：2012-04-01 00:00:00
abstract：BACKGROUND:There are 45 known genetic diseases that impair the lysosomal degradation of macromolecules. The loss of a single lysosomal hydrolase leads to the accumulation of its undegraded substrates in tissues and increases of related glycoconjugates in urine, some of which can be detected by screening of free oligosa...
journal_title：Clinical chemistry
pub_type： 杂志文章
doi：10.1373/clinchem.2012.201053
更新日期：2013-09-01 00:00:00
abstract：BACKGROUND:Next generation sequencing (NGS)-based assays continue to redefine the field of genetic testing. Owing to the complexity of the data, bioinformatics has become a necessary component in any laboratory implementing a clinical NGS test. CONTENT:The computational components of an NGS-based work flow can be conc...
journal_title：Clinical chemistry
pub_type： 杂志文章,评审
doi：10.1373/clinchem.2014.224360
更新日期：2015-01-01 00:00:00
abstract：:We describe a multiprobe colorimeter that permits the reading of enzyme-linked immunosorbent assays (ELISA) in situ, by use of microhemagglutination plates. The use of dipping probes eliminates interference from meniscus effects and air-bubble entrapment. Detailed validation tests have been done and potential sources ...
journal_title：Clinical chemistry
pub_type： 杂志文章
doi：
更新日期：1979-04-01 00:00:00
abstract：:We compared results obtained with the Beckman Creatinine Analyzer (Beckman Instruments, Inc.) to those with the GEMSAEC Centrifugal Analyzer (Electro-Nucleonics, Inc.) and with a manual method for determination of creatinine in serum and urine. Linearity, stability, recovery, and precision were evaluated. Interference...
journal_title：Clinical chemistry
pub_type： 杂志文章
doi：
更新日期：1979-06-01 00:00:00
abstract：BACKGROUND:Meconium analysis is a diagnostically sensitive and objective alternative to maternal self-report for detecting prenatal tobacco exposure. Nicotine and metabolite disposition in meconium is poorly characterized, and correlation of analytes' concentrations with neonatal outcomes is unexplored. Our objectives ...
journal_title：Clinical chemistry
pub_type： 杂志文章
doi：10.1373/clinchem.2008.109173
更新日期：2008-12-01 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：:Numerous xenobiotics regulate cellular functions by altering transcription of target genes. Use of sensitive and specific biomarkers based on gene transcript levels may help clarify the shape of the dose-response curve in the low-dose region associated with human exposures to environmental concentrations of chemicals....
journal_title：Clinical chemistry
pub_type： 杂志文章,评审
doi：
更新日期：1995-12-01 00:00:00
abstract：:The concentrations of 25 plasma proteins were measured in 22 patients with membranous nephropathy. For some large proteins, the plasma concentrations were increased; there were also large proteins with low plasma concentrations, but small or medium-sized proteins showed uniformly lower plasma concentration than the co...
journal_title：Clinical chemistry
pub_type： 杂志文章
doi：
更新日期：1997-07-01 00:00:00
abstract：:We compared the activities of thyroid-stimulating antibodies (TSAb) measured in cultures of human thyrocytes and the values for thyrotropin-receptor antibodies (TRAb) as measured with a commercial kit based on use of radiolabeled receptors. Sera were obtained from patients with Graves' disease before, during, and afte...
journal_title：Clinical chemistry
pub_type： 杂志文章
doi：
更新日期：1986-07-01 00:00:00
abstract：:Intra-erythrocytic pH, ATP concentrations, and 2,3-diphosphoglycerate relaxation times were studied in living erythrocytes by "high-resolution" 31P NMR spectroscopy to assess homeostasis within the cells. In uremic patients, intra-erythrocytic pH is significantly decreased before hemodialysis, but is corrected equally...
journal_title：Clinical chemistry
pub_type： 杂志文章
doi：
更新日期：1987-01-01 00:00:00
