Abstract:
BACKGROUND:Patients with trophoblastic diseases produce ordinary and irregular forms of human chorionic gonadotropin (hCG; e.g., nicked hCG, hCG missing the beta-subunit C-terminal segment, hyperglycosylated hCG, and free beta subunit) that are recognized to differing extents by automated immunometric hCG (or hCG beta) assays. This has led to low or false-negative results and misdiagnosis of persistent disease. False-positive hCG immunoreactivity has also been detected, leading to needless therapy for trophoblastic diseases. Here we compare seven commonly used hCG assays. METHODS:Standards for five irregular forms hCG produced in trophoblastic diseases, serum samples from 59 patients with confirmed trophoblastic diseases, and serum samples from 12 women with previous false-positive hCG results (primarily in the Abbott AxSYM assay) were blindly tested by commercial laboratories in the Beckman Access hCG beta, the Abbott AxSYM hCG beta, the Chiron ACS:180 hCG beta, the Baxter Stratus hCG test, the DPC Immulite hCG test, the Serono MAIAclone hCG beta tests, and in the hCG beta RIA. RESULTS:Only the RIA and the DPC appropriately detected the five irregular hCG standards. Only the Beckman, DPC, and Abbott assays gave results similar to the RIA in the patients with confirmed trophoblastic diseases (values within 25% of RIA in 49, 49, and 54 of 59 patients, respectively). For samples that were previously found to produce false-positive hCG results, no false-positive results were detected with the DPC and Chiron tests (5 samples, median <2 IU/L), but up to one-third of samples were false positive (>10 IU/L) in the Beckman (1 of 5), Serono (2 of 9), and Baxter assays (1 of 5), and the hCG beta RIA (3 of 9; median for all assays, <5 IU/L). These samples, which produced false-positive results earlier in the Abbott AxSYM assay, continued to produce high values upon reassessment (median, 81 IU/L). CONCLUSIONS:Of six frequently used hCG immunometric assays, only the DPC detected the five irregular forms of beta hCG, agreed with the RIA, and avoided false-positive results in the samples tested. This assay, and similarly designed assays not tested here, seem appropriate for hCG testing in the diagnosis and management of trophoblastic diseases.
journal_name
Clin Chemjournal_title
Clinical chemistryauthors
Cole LA,Shahabi S,Butler SA,Mitchell H,Newlands ES,Behrman HR,Verrill HLsubject
Has Abstractpub_date
2001-02-01 00:00:00pages
308-15issue
2eissn
0009-9147issn
1530-8561journal_volume
47pub_type
杂志文章abstract::Methods are described for detection of lactate dehydrogenase (LDH) inhibitors in preparations of reduced nicotinamide adenine dinucleotide. They are (a) comparison of values by kinetic methods with those measured for highly purified NADH and (b) examination of Lineweaver-Burk plots. Chromatographic inhomogeneities are...
journal_title:Clinical chemistry
pub_type: 杂志文章
doi:
更新日期:1976-10-01 00:00:00
abstract::Red blood cell (RBC) replacement solutions are being developed as alternatives to allogeneic RBC use in blood transfusions in the treatment of massive trauma, to achieve hemodynamic stability during elective surgery, and to increase oxygen-carrying capacity in anemia. Hemoglobin-based oxygen carrier (HBOC)-201 (Biopur...
journal_title:Clinical chemistry
pub_type: 杂志文章
doi:
更新日期:1997-09-01 00:00:00
abstract::Polyacrylamide has been the matrix of choice for isoelectric focusing owing to the virtual absence of electroendosmosis in this medium. Certain inherent limitations associated with polyacrylamide have prompted some investigators to use low-electroendosmosis agarose for isoelectric focusing, but with limited success th...
journal_title:Clinical chemistry
pub_type: 杂志文章
doi:
更新日期:1983-02-01 00:00:00
abstract::We report a case of hyperphosphatasemia in a 35-year-old patient with hepatitis B who underwent an orthotopic xenogeneic liver transplant. Marked increases in total alkaline phosphatase (ALP; EC 3.1.3.1) activity began 5 days posttransplantation (six times human normal) and increased to approximately 17 times normal a...
journal_title:Clinical chemistry
pub_type: 杂志文章
doi:
更新日期:1994-07-01 00:00:00
abstract::Recent evidence indicates that high-density lipoprotein triglyceride (HDL-Tg) may be a predictor of coronary artery disease. We examined three methods for HDL-Tg measurement, comparing results obtained by measurement of Tg in the supernate after heparin-manganese chloride (heparin-Mn) precipitation of EDTA-treated pla...
journal_title:Clinical chemistry
pub_type: 杂志文章
doi:
更新日期:1988-10-01 00:00:00
abstract:BACKGROUND:High-resolution DNA melting analysis of small amplicons is a simple and inexpensive technique for genotyping. Microfluidics allows precise and rapid control of temperature during melting. METHODS:Using a microfluidic platform for serial PCR and melting analysis, 4 targets containing single nucleotide varian...
journal_title:Clinical chemistry
pub_type: 杂志文章
doi:10.1373/clinchem.2017.276147
更新日期:2017-10-01 00:00:00
abstract::We developed an automated method for measurement of alpha-amylase isoenzymes in serum by a single kinetic assay (SKA) and a double kinetic assay (DKA) with 2-chloro-4-nitrophenyl-6(5)-azido-6(5)-deoxy-beta-maltopentaoside as a substrate and 6(3)-deoxymaltotriose (DOG3) as a novel selective amylase inhibitor. DOG3 show...
journal_title:Clinical chemistry
pub_type: 杂志文章
doi:
更新日期:1995-04-01 00:00:00
abstract:BACKGROUND:Paraoxonase may mitigate oxidative damage and thus lower risk of macrovascular disease. METHODS:DNA samples from 2252 participants in the Coronary Artery Risk Development in Young Adults (CARDIA) study were genotyped for the L55M and Q192R polymorphisms of the PON1 (paraoxonase 1) gene, and paraoxonase acti...
journal_title:Clinical chemistry
pub_type: 杂志文章,多中心研究
doi:10.1373/clinchem.2007.099044
更新日期:2008-04-01 00:00:00
abstract::We studied the effect of lyophilization of serum pools on the determination of cholesterol with the enzymatic methods used in five automated analyzers: SMAC (Technicon), the RA-1000 (Technicon), the aca (Du Pont), the TDx (Abbott), and the Ektachem 700P (Kodak). We prepared two serum pools: pool A (2.2 g/L) and pool B...
journal_title:Clinical chemistry
pub_type: 杂志文章
doi:
更新日期:1989-07-01 00:00:00
abstract::A digestion procedure involving nitric acid is described for determination of aluminum in blood, serum, and plasma by graphite-furnace atomic absorption spectroscopy. Contamination was not a severe problem if all operations were performed in a dust-free atmosphere. Conditions for such determination of aluminum in bloo...
journal_title:Clinical chemistry
pub_type: 杂志文章
doi:
更新日期:1982-11-01 00:00:00
abstract::We can detect the beta-globin gene sickle cell mutation by using an assay based on the ligase chain reaction. The simultaneous amplification of the human growth hormone gene in the same reaction serves as a control for the amount of template DNA or amplification efficiency. Ligation products, which are biotinylated at...
journal_title:Clinical chemistry
pub_type: 杂志文章
doi:
更新日期:1997-01-01 00:00:00
abstract:BACKGROUND:Recent reports have described inherent problems with androgen immunoassays compared with mass spectrometry analyses. METHODS:We developed a method for measuring serum testosterone (T) and 5alpha-dihydrotestosterone (DHT) simultaneously via liquid-liquid extraction followed by liquid chromatography-tandem ma...
journal_title:Clinical chemistry
pub_type: 杂志文章
doi:10.1373/clinchem.2008.103846
更新日期:2008-11-01 00:00:00
abstract::We have developed a new assay for cortisone (E) in serum, saliva, and urine involving Celite chromatography followed by RIA with 125I-labeled E and scintillation proximity assay. The chromatography step separates cortisol (F) from E, and in combination with their RIAs, permits assessment of the status of the F-E shutt...
journal_title:Clinical chemistry
pub_type: 杂志文章
doi:
更新日期:1997-08-01 00:00:00
abstract::The Arg-to-Trp substitution at codon 3500 in the apolipoprotein (apo) B-100 gene is established as a cause of familial defective apo B-100 (FDB), a functional mutation, resulting in reduced LDL receptor binding and manifest hypercholesterolemia. In a search for similar mutations in 163 Malaysians, we screened the puta...
journal_title:Clinical chemistry
pub_type: 杂志文章
doi:
更新日期:1997-06-01 00:00:00
abstract::We evaluated a newly developed solid-phase immunoassay (EIA) of terminal deoxynucleotidyl transferase (TdT, EC 2.7.7.3) and compared it with the enzymatic assay of TdT involving DNA polymerase. We assessed the precision, performance characteristics, and clinical efficacy of the EIA procedure, using 249 specimens of pe...
journal_title:Clinical chemistry
pub_type: 杂志文章
doi:
更新日期:1987-02-01 00:00:00
abstract::This rapid radioimmunoassay for aldosterone is performed directly on 100 microL of unprocessed plasma, with 125I-labeled aldosterone as the labeled antigen. Our use of steroid-free plasma in preparing the standard curve resulted in an overestimate of aldosterone; this problem was overcome by adding to such plasma a mi...
journal_title:Clinical chemistry
pub_type: 杂志文章
doi:
更新日期:1983-02-01 00:00:00
abstract::We studied the recently developed Abbott fluorescence polarization immunoassay (FPIA) for amphetamine and methamphetamine in urine and compared the results with those of the Syva enzyme-multiplied immunoassay technique (EMIT) and a gas-chromatographic assay. The FPIA method showed a limit of quantification of 0.3 mg/L...
journal_title:Clinical chemistry
pub_type: 杂志文章
doi:
更新日期:1987-07-01 00:00:00
abstract::We have compared the operational, medical, and fiscal consequences of performing urgent glucose testing at the bedside vs in the central laboratory. The turnaround time (TAT) with bedside testing was only 1-2 min shorter than that from the central laboratory, to which specimens are sent by pneumatic tube and from whic...
journal_title:Clinical chemistry
pub_type: 杂志文章
doi:
更新日期:1994-08-01 00:00:00
abstract::We tested a new amylase reagent involving chromogenic substrates (Pantrak, Calbiochem-Behring) for precision, dynamic range, and susceptibility to potential interferences. Two p-nitrophenyl-alpha-maltaosides are used as substrates, which amylase cleaves to shorter-chain p-nitrophenyl maltaosides, the latter then yield...
journal_title:Clinical chemistry
pub_type: 杂志文章
doi:
更新日期:1982-04-01 00:00:00
abstract::We determined fluoxetine (Prozac) and its major metabolite norfluoxetine in plasma by liquid chromatography with fluorescence detection. After liquid-liquid extraction from 1 mL of plasma, the extract was derivatized at room temperature with dansyl chloride, and the highly fluorescent derivatives were chromatographed ...
journal_title:Clinical chemistry
pub_type: 杂志文章
doi:
更新日期:1992-09-01 00:00:00
abstract::A new, highly sensitive immunoradiometric thyrotropin (TSH) assay involving solid-phase-coupled monoclonal antibodies (Boots-Celltech Sucrosep IRMA-TSH) has been evaluated in a wide variety of patients with thyroidal and nonthyroidal illnesses and the results compared with those obtained by conventional diagnostic TSH...
journal_title:Clinical chemistry
pub_type: 杂志文章
doi:
更新日期:1986-03-01 00:00:00
abstract::Values of low-density lipoprotein (LDL) cholesterol (C) according to the Friedewald formula (Clin Chem 1972;18:499-502) were compared with those obtained by lipoprotein fractionation in 98 healthy subjects (control group), 135 specimens from patients with peripheral vascular and cerebrovascular disease (atheroscleroti...
journal_title:Clinical chemistry
pub_type: 杂志文章
doi:
更新日期:1991-08-01 00:00:00
abstract:BACKGROUND:Microalbuminuria (MA) is recognized as an important risk factor for cardiovascular and renal complications in diabetes. We sought to evaluate how screening for MA is conducted and how urine albumin (UA) results are interpreted in primary care internationally. METHODS:General practitioners (GPs) received a c...
journal_title:Clinical chemistry
pub_type: 杂志文章
doi:10.1373/clinchem.2007.100917
更新日期:2008-10-01 00:00:00
abstract::Human myocardial creatine kinase isoenzyme MM is present as a single form in tissue, but upon its release into plasma two additional forms, with faster anodal migration, are apparent on polyacrylamide electrophoresis. We designate the three forms as MM3, MM2, and MM1 in increasing order of anodal mobility. When tissue...
journal_title:Clinical chemistry
pub_type: 杂志文章
doi:
更新日期:1984-05-01 00:00:00
abstract::We have assessed the technical performance and robustness of NycoCard CRP Whole Blood, a near-patient test for C-reactive protein (CRP), when used in realistic daily routine situations in general practice clinics (GPC). Thirteen GPCs participated, five of them with technician staff. From 898 patients, split-sample mea...
journal_title:Clinical chemistry
pub_type: 杂志文章
doi:
更新日期:1997-11-01 00:00:00
abstract::We describe a radioassay for cobalamin (vitamin B12) in human serum or plasma that requires no boiling or other pretreatment of the sample. Normal chicken serum covalently coupled to magnetizable particles is used as the binding agent. The assay is performed at pH 12.9, at which pH all cobalamin in human serum is rele...
journal_title:Clinical chemistry
pub_type: 杂志文章
doi:
更新日期:1981-02-01 00:00:00
abstract::Two hundred patients with liver disease were re-studied after six to eight years. The initial routine diagnosis (mainly based on morphological criteria) was confirmed in almost 80% of cases of chronic liver disease. In chronic active hepatitis, agreement was found in 86%. An alternative classification based on cluster...
journal_title:Clinical chemistry
pub_type: 杂志文章
doi:
更新日期:1982-05-01 00:00:00
abstract:BACKGROUND:C-reactive protein (CRP) increases in response to inflammation and is purported to be a risk factor for atherogenesis. We recently demonstrated that a scavenger receptor, lectin-like oxidized LDL receptor (LOX-1), is a receptor for CRP. In light of the overlapping ligand spectrum of scavenger receptors such ...
journal_title:Clinical chemistry
pub_type: 杂志文章
doi:10.1373/clinchem.2009.140202
更新日期:2010-03-01 00:00:00
abstract:BACKGROUND:Calcitonin (CT) is a sensitive marker for evaluation of medullary thyroid cancer (MTC). However, CT measurement can vary with assay- and nonassay-dependent factors, and procalcitonin (PCT) measurement has been proposed for evaluating questionable increases in CT. METHODS:We tested 2 fully automated CT assay...
journal_title:Clinical chemistry
pub_type: 杂志文章
doi:10.1373/clinchem.2010.151688
更新日期:2011-03-01 00:00:00
abstract::We describe a chromatographic procedure for sensitive (2.0 mumol/L), specific quantification of vanillylmandelic acid (VMA) in urine with iso-VMA as an internal standard. After rapid extraction from urine, the VMA is determined by isocratic reversed-phase ion-pair chromatography on a bonded C8 column and detection of ...
journal_title:Clinical chemistry
pub_type: 杂志文章
doi:
更新日期:1986-04-01 00:00:00