Abstract：
:Clinically relevant interassay precision profiles for thyrotropin (thyroid-stimulating hormone; TSH) were constructed with human serum pools measured over 4-8 weeks by six immunometric assays, in at least two different reagent lots. Functional sensitivities (the concentration at which the interassay CV is < or = 20%) were determined in four to eight clinical laboratories plus the respective manufacturer's laboratory. These studies revealed that the manufacturer's stated functional sensitivity limit is rarely duplicated in clinical practice. Loss of specificity (indicated by artifactually high values) was seen with some methods when used to measure certain unrefrigerated low-TSH sera. Measurement of TSH in four human serum pools (TSH < 0.05-0.25 mIU/L) by 16 different methods (each in at least eight UK or US laboratories) showed that some methods could not reliably distinguish subnormal from normal TSH values. Better pool rankings and fewer misclassifications of low-TSH sera as "normal" were seen with use of assays capable of "third-generation" functional sensitivity (0.01-0.02 mIU/L) than with assays with "second-generation" functional sensitivity (0.1-0.2 mIU/L). Because inter- and intramethod differences in functional sensitivity negatively impact the diagnostic accuracy and cost-effectiveness of a TSH-centered thyroid-testing strategy, laboratories should independently establish an assay's functional sensitivity by a clinically relevant protocol. Moreover, manufacturers should assess functional sensitivity more realistically and improve the robustness of assays to ensure that their performance potential is consistently met in clinical practice.
journal_name
Clin Chemjournal_title
Clinical chemistryauthors
Spencer CA,Takeuchi M,Kazarosyan M,MacKenzie F,Beckett GJ,Wilkinson Esubject
Has Abstractpub_date
1995-03-01 00:00:00pages
367-74issue
3eissn
0009-9147issn
1530-8561journal_volume
41pub_type
杂志文章abstract：:This one-dimensional thin-layer chromatographic method is used for assay of phospholipids in the gastric aspirate of newborns. The solvent mixture (chloroform/hexane/methanol/glacial acetic acid/water, 12/7/4/3/0.3 by vol) completely resolves lecithin, sphingomyelin, phosphatidylinositol, phosphatidylserine, phosphati...
journal_title：Clinical chemistry
pub_type： 杂志文章
doi：
更新日期：1988-04-01 00:00:00
abstract：:We evaluated the analytical performance of new estradiol and progesterone assays performed on the Bayer Immuno 1 system. Within-run and between-day CVs for estradiol at concentrations of 116.8-6645.8 pmol/L were < or = 6.4% and for 5.54-103.95 nmol/L progesterone were < or = 7.7%, thus meeting published analytical goa...
journal_title：Clinical chemistry
pub_type： 杂志文章
doi：
更新日期：1997-09-01 00:00:00
abstract：BACKGROUND:Direct equilibrium dialysis and direct ultrafiltration free thyroxine (T(4)) assays rely on semipermeable membranes to exclude T(4)-binding serum proteins from dialysates and ultrafiltrates. The presence of these proteins in dialysates or ultrafiltrates will yield spuriously high free T(4) values when free T...
journal_title：Clinical chemistry
pub_type： 杂志文章
doi：10.1373/clinchem.2007.085316
更新日期：2007-05-01 00:00:00
abstract：:The most popular pretreatment method of plasma samples for the measurement of ascorbate (AsA) and dehydroascorbate (DHA) has been an acidic deproteinization via metaphosphoric acid or trichloroacetic acid. In general, DHA is absent in plasma samples prepared from human blood in a conventional manner. However, when the...
journal_title：Clinical chemistry
pub_type： 杂志文章
doi：
更新日期：1998-04-01 00:00:00
abstract：:This two-site immunoradiometric assay for human parathyrin-related protein 1-86 (PTHRP1-86) in plasma uses a mouse monoclonal antibody to PTHRP1-34 coupled to cellulose particles for immunoextraction of N-terminal immunoreactivity, and a rabbit antiserum to PTHRP37-67 that is indirectly labeled with 125I-labeled PTHRP...
journal_title：Clinical chemistry
pub_type： 杂志文章
doi：
更新日期：1991-05-01 00:00:00
abstract：:A plasma protein required for the support of ristocetin-induced platelet aggregation was isolated from antihemophilic factor concentrate and radiolabeled with 125I. A double-antibody radioimmunoassay was developed, with use of specific rabbit anti-VIII related antigen serum and goat anti-rabbit globulin. The assay is ...
journal_title：Clinical chemistry
pub_type： 杂志文章
doi：
更新日期：1977-09-01 00:00:00
abstract：:The new oral formulation of cyclosporine (CsA), Neoral (CsA-N), results in increased area under the curve (AUC) and decreased intra- and interindividual variation in blood concentrations and other pharmacokinetic (PK) parameters when compared with the current Sand-immune (CsA-S) formulation. The present study examines...
journal_title：Clinical chemistry
pub_type： 杂志文章
doi：
更新日期：1997-01-01 00:00:00
abstract：:We have developed two methods for determining serum concentrations of felbamate, a new anticonvulsant drug. The first method is based on protein precipitation with acetonitrile, followed by HPLC. The between-run CV for this method is 5.7% (mean 55 mg/L), and the linearity extends from 5 to 175 mg/L. Results by this me...
journal_title：Clinical chemistry
pub_type： 杂志文章
doi：
更新日期：1994-10-01 00:00:00
abstract：BACKGROUND:Commercial immunoassays for testosterone (Te) may give inaccurate results for samples from women and children, leading to misdiagnosis and inappropriate treatment. We developed a sensitive and specific tandem mass spectrometric assay for measurement of Te at the concentrations encountered in women and childr...
journal_title：Clinical chemistry
pub_type： 杂志文章
doi：10.1373/clinchem.2005.052167
更新日期：2006-01-01 00:00:00
abstract：BACKGROUND:Formation of deposits of the insoluble amyloid beta-peptide is believed to be causally related with neurodegeneration in Alzheimer disease (AD). The beta-peptide originates from a larger amyloid precursor protein (APP) by the action of proteolytic enzymes. The first proteolytic event leading to amyloid forma...
journal_title：Clinical chemistry
pub_type： 杂志文章
doi：10.1373/clinchem.2006.066720
更新日期：2006-06-01 00:00:00
abstract：:Measurements of alanine aminotransferase and aspartate aminotransferase with the SMAC were evaluated for correlation with the ABA-100, precision, linearity, and carryover. We assayed 200 specimens with normal and abnormal aminotransferase activities with both the SMAC (y) and the ABA-100 (X). Linear regression analysi...
journal_title：Clinical chemistry
pub_type： 杂志文章
doi：
更新日期：1979-05-01 00:00:00
abstract：BACKGROUND:The European Atherosclerosis Society-European Federation of Clinical Chemistry and Laboratory Medicine Consensus Panel aims to provide recommendations to optimize atherogenic lipoprotein quantification for cardiovascular risk management. CONTENT:We critically examined LDL cholesterol, non-HDL cholesterol, a...
journal_title：Clinical chemistry
pub_type： 杂志文章
doi：10.1373/clinchem.2018.287037
更新日期：2018-07-01 00:00:00
abstract：:In iron deficiency, zinc protoporphyrin (ZPP) is produced instead of heme, and the ZPP concentration in erythrocytes is increased (normal < or = 40 mumol/mol heme). We investigated the relevance of ZPP for staging iron deficiency. ZPP was determined by hematofluorometry in samples from 103 patients. Nineteen patients ...
journal_title：Clinical chemistry
pub_type： 杂志文章
doi：
更新日期：1994-05-01 00:00:00
abstract：:We describe a gas chromatographic method for measuring submicrogram quantities of dianhydrogalactitol, a promising antineoplastic agent (currently undergoing clinical trials in humans), in plasma. The drug is first extracted from blood plasma by saturating the aqueous phase with solid potassium carbonate and extractin...
journal_title：Clinical chemistry
pub_type： 杂志文章
doi：
更新日期：1976-10-01 00:00:00
abstract：:A highly sensitive sandwich-type chemiluminescence enzyme immunoassay for plasma endothelin-I (ET-1), involving no extraction steps, has been developed. Two populations of polyclonal antibodies were used in the present study: One is specific to the C-terminus of the endothelin family of peptides; the other, a Fab' fra...
journal_title：Clinical chemistry
pub_type： 杂志文章
doi：
更新日期：1996-08-01 00:00:00
abstract：BACKGROUND:Plant-derived cardenolides reportedly possess anticancer properties in human leukemic cells via selective induction of apoptosis, cell cycle arrest, and differentiation. Selective induction of apoptosis with mammalian-derived digoxin-like immunoreactive factor (DLIF) could provide new strategies for anticanc...
journal_title：Clinical chemistry
pub_type： 杂志文章
doi：10.1373/clinchem.2006.082081
更新日期：2007-07-01 00:00:00
abstract：BACKGROUND:Suspension array technology has surpassed ELISA for automated, simultaneous detection and quantification of soluble biomarkers such as virus-specific antibodies. We describe assays in which antigens are attached to a lipid bilayer surrounding color-coded particles. METHODS:We used layer-by-layer technology ...
journal_title：Clinical chemistry
pub_type： 杂志文章
doi：10.1373/clinchem.2005.065789
更新日期：2006-08-01 00:00:00
abstract：:The identification of nicotinamide-N1-oxide as a metabolite in the urine of a schizophrenic patient prompted a study of the relative metabolism of nicotinic acid and nicotinamide in mental patients and healthy volunteers. Metabolites quantified included N1-methyl-2-pyridone-5-carboxamide, N1-methyl-4-pyridone-3-carbox...
journal_title：Clinical chemistry
pub_type： 杂志文章
doi：
更新日期：1976-11-01 00:00:00
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 developed a simple method for the analysis of bismuth (Bi) in biological tissue, using wet digestion for sample pretreatment. Bi was determined by electrothermal atomic absorption spectrometry with platinum as a matrix modifier to decrease the volatility of Bi. The furnace program included a gas stop for sensitivit...
journal_title：Clinical chemistry
pub_type： 杂志文章
doi：
更新日期：1993-05-01 00:00:00
abstract：:Apoprotein (apo) C-I, C-II, and C-III were measured in plasma from 35 white American non-diabetic subjects. The mean concentrations (mg/L) in plasma from normolipidemic and hypertriglyceridemic subjects, respectively, were apo C-I, 78 and 311; apo C-II, 37 and 200; and apo C-III, 98 and 529. These concentrations were ...
journal_title：Clinical chemistry
pub_type： 杂志文章
doi：
更新日期：1986-10-01 00:00:00
abstract：:We describe a convenient, economical procedure for measuring uroporphyrinogen I synthase (EC 4.3 1.8) activity in erythrocytes, the results of which can be used to diagnose acute intermittent porphyria, in either its latent or acute stage. By limiting the test reaction sequence to the conversion of porphobilinogen to ...
journal_title：Clinical chemistry
pub_type： 杂志文章
doi：
更新日期：1980-07-01 00:00:00
abstract：:We measured cyclosporine in whole blood from normal volunteers administered single oral doses of the drug and from two renal-transplant patients on immunosuppressive maintenance therapy, by liquid chromatography (I) and by radioimmunoassay with use of nonspecific polyclonal (II), specific monoclonal (III), and nonspec...
journal_title：Clinical chemistry
pub_type： 杂志文章
doi：
更新日期：1987-12-01 00:00:00
abstract：BACKGROUND:Although microRNAs (miRNAs) play essential roles in spermatogenesis, little is known about seminal plasma miRNAs in infertile men. We investigated the profile of seminal plasma miRNAs in infertile men to identify miRNAs that are altered in infertility; we then evaluated their diagnostic value. METHODS:Semin...
journal_title：Clinical chemistry
pub_type： 杂志文章
doi：10.1373/clinchem.2011.169714
更新日期：2011-12-01 00:00:00
abstract：:We have developed a liquid chromatography-isotope dilution mass spectrometry procedure to quantify total cholesterol in serum. A particle-beam interface was used for coupling the liquid chromatograph and the mass spectrometer. After electron impact ionization the ions m/z = 386 and m/z = 389 were used for selective io...
journal_title：Clinical chemistry
pub_type： 杂志文章
doi：
更新日期：1997-10-01 00:00:00
abstract：BACKGROUND:Hepcidin-25 reduces iron absorption by binding to the intestinal iron transporter ferroportin and causing its degradation. Currently, little is known about the basal regulation of circulating hepcidin-25. In addition, although erythropoietin administration has been reported to decrease the circulating hepcid...
journal_title：Clinical chemistry
pub_type： 杂志文章
doi：10.1373/clinchem.2012.186866
更新日期：2012-08-01 00:00:00
abstract：:We compared cyclosporine concentrations in whole blood as measured by HPLC and by RIA with a monoclonal antibody specific for cyclosporine with 3H- or 125I-labeled cyclosporine ligand. The 3H-RIA kit slightly underestimated cyclosporine concentrations (greater than 600 micrograms/L) in comparison with HPLC. Over a wid...
journal_title：Clinical chemistry
pub_type： 杂志文章
doi：
更新日期：1989-01-01 00:00:00
abstract：BACKGROUND:Subfractions of HDL, particularly large HDL (HDL2), are inversely correlated with the severity of coronary artery disease (CAD). alpha-Tocopherol (AT) is the main lipid-soluble antioxidant in plasma. Results of a previous small study (n = 44) suggested that either a combination of an antioxidant cocktail [80...
journal_title：Clinical chemistry
pub_type： 杂志文章,随机对照试验
doi：10.1373/clinchem.2006.078865
更新日期：2007-03-01 00:00:00
abstract：:Lactate dehydrogenase (LD) isoenzymes 1 and 2 in human serum were separated on a column of diethylaminoethyl-Sephadex. Samples layered on mini-columns were eluted with buffered sodium chloride (100, 150, and 200 mmol/liter). Lactate dehydrogenase activity in column effluents was measured by the Wacker method, and thei...
journal_title：Clinical chemistry
pub_type： 杂志文章
doi：
更新日期：1978-03-01 00:00:00
abstract：BACKGROUND:Bilirubin has antioxidative and cytoprotective properties. Low plasma concentrations of bilirubin are reportedly associated with the development of coronary and cerebrovascular disease, and bilirubin concentrations are strongly correlated with the enzyme activity of the hepatic uridine diphosphate glucuronos...
journal_title：Clinical chemistry
pub_type： 临床试验,杂志文章
doi：10.1373/clinchem.2007.102046
更新日期：2008-05-01 00:00:00
