Abstract：
BACKGROUND:Standardization of hemoglobin (Hb)A(1c) measurements is a process of considerable interest for quality assurance in diabetes management. To contribute to continuous quality improvement and fulfillment of the requirements for reference measurement procedures according to the standards of the International Organization for Standardization, we developed a calibration system of highest metrological order using isotope dilution-mass spectrometry with a reference material. METHOD:Samples were prepared by enzymatic cleavage based on the IFCC reference measurement procedure for LC-MS analysis. After digestion the samples were spiked with [D7]-labeled glycated and nonglycated hexapeptides as internal standards for quantification. LC-MS analysis was performed by using a C12 reversed-phase column and a gradient of acetonitrile/H(2)O containing 0.1% formic acid. RESULTS:Calibration systems for HbA(1c) determination based on liquid chromatography-isotope dilution-mass spectrometry (LC-ID-MS) and on the IFCC reference measurement procedure were compared. A linear regression analysis demonstrated a correlation of r(2) = 1.00 between the 2 different calibration systems. Mean deviation was 5.5% for the calibration and 3.3% for hemolysate samples, with a mean expanded uncertainty of 4.9%. CONCLUSIONS:This LC-ID-MS procedure allows the current IFCC reference measurement procedure for HbA(1c) to be raised to a higher order of accuracy.
journal_name
Clin Chemjournal_title
Clinical chemistryauthors
Kaiser P,Akerboom T,Ohlendorf R,Reinauer Hdoi
10.1373/clinchem.2009.139477subject
Has Abstractpub_date
2010-05-01 00:00:00pages
750-4issue
5eissn
0009-9147issn
1530-8561pii
clinchem.2009.139477journal_volume
56pub_type
杂志文章abstract：:We compared cotinine, carboxyhemoglobin, and thiocyanate concentrations in blood sampled from 187 cigarette smokers and 181 non-smokers. All three differed significantly between smokers and non-smokers. Cotinine performed best as a test for assessing smoking status, with a sensitivity of 98% as compared with 94% for c...
journal_title：Clinical chemistry
pub_type： 杂志文章
doi：
更新日期：1984-08-01 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：:In response to the pressures of cost reduction, we established and evaluated a carefully integrated program to deliver clinical laboratory services more promptly and efficiently to the intensive care units (ICUs). The new protocol reduced the steps and turnaround time from ordering tests by physicians to reporting res...
journal_title：Clinical chemistry
pub_type： 杂志文章
doi：
更新日期：1996-03-01 00:00:00
abstract：:To demonstrate oligoclonal IgG bands (I) in unconcentrated cerebrospinal fluid, we used isoelectric focusing in agarose followed by protein transfer to cellulose nitrate membrane, double-antibody peroxidase labeling, and avidin-biotin amplification. I can be reliably seen after isoelectric focusing of 5-microL specime...
journal_title：Clinical chemistry
pub_type： 杂志文章
doi：
更新日期：1984-07-01 00:00:00
abstract：:We studied the pattern of acute-phase proteins (orosomucoid, C-reactive protein, and haptoglobin) in hepatocellular deficiency due to chronic alcohol consumption, characterized by a decrease in serum transferrin concentration. We found that their patterns could vary independently of hepatocellular deficiency, but depe...
journal_title：Clinical chemistry
pub_type： 杂志文章
doi：
更新日期：1983-01-01 00:00:00
abstract：:Haptoglobin is a hemoglobin-binding protein expressed by a genetic polymorphism as three major phenotypes: 1-1, 2-1, and 2-2. Most attention has been paid to determining haptoglobin phenotype as a genetic fingerprint used in forensic medicine. More recently, several functional differences between haptoglobin phenotype...
journal_title：Clinical chemistry
pub_type： 杂志文章,评审
doi：
更新日期：1996-10-01 00:00:00
abstract：:We report microchromatographic measurement of fetal hemoglobin (HbF) proportions in a 36-year-old African-American multigravida woman. At 34 weeks she delivered a 630-g male infant who subsequently did well. Hemoglobin electrophoresis of the hemolysate revealed nearly 100% HbF without HbA, an extremely unusual natural...
journal_title：Clinical chemistry
pub_type： 杂志文章
doi：
更新日期：1992-11-01 00:00:00
abstract：:We investigated the ability of neural networks to diagnose acute myocardial infarction (AMI) from laboratory data only. Several networks were trained with different combinations of data obtained at admission and within the first 12 h and 24 h after admission. The data used included the electrocardiogram (ECG) and the ...
journal_title：Clinical chemistry
pub_type： 杂志文章
doi：
更新日期：1996-04-01 00:00:00
abstract：BACKGROUND:Screening for heterozygous sequence changes in PCR products, also known as "mutation scanning", is an important tool for genetic research and clinical applications. Conventional methods require a separation step. METHODS:We evaluated the sensitivity and specificity of homogeneous scanning, using a saturatin...
journal_title：Clinical chemistry
pub_type： 杂志文章
doi：10.1373/clinchem.2003.029751
更新日期：2004-10-01 00:00:00
abstract：:A 56-year-old Samoan man with a documented history of hypertension, who presented with atrial fibrillation and hypotension, quickly developed renal failure with a serum urea nitrogen of 1.370 g/L and a serum creatinine of 92 mg/L. After hydration of the patient, the creatinine value became normal in two days, the urea...
journal_title：Clinical chemistry
pub_type： 杂志文章
doi：
更新日期：1979-11-01 00:00:00
abstract：BACKGROUND:Measurement of serum thyroglobulin (Tg) is used to monitor patients after treatment for differentiated thyroid carcinoma (TC). Difficulty in using Tg as a biomarker of the recurrence of TC in many patients stems from the presence of endogenous anti-Tg autoantibodies (Tg-AAbs), which can interfere with immuno...
journal_title：Clinical chemistry
pub_type： 杂志文章
doi：10.1373/clinchem.2012.195594
更新日期：2013-06-01 00:00:00
abstract：:A potential genetic marker for hypertriglyceridemia and coronary disease, an apolipoprotein-CIII gene allele displaying a single nucleotide substitution, was found in 71% of Arabs with primary hypertriglyceridemia. Over 96% of the unrelated adults possessing this allele showed hypertriglyceridemia. The same allele was...
journal_title：Clinical chemistry
pub_type： 杂志文章
doi：
更新日期：1989-02-01 00:00:00
abstract：BACKGROUND:In patient and population samples, generation of analytical results that are comparable and independent of the measurement system, time, and location is essential for the utility of laboratory information supplied in healthcare. Obtaining analytical measurement results with such characteristics is the aim of...
journal_title：Clinical chemistry
pub_type： 杂志文章,评审
doi：10.1373/clinchem.2008.107052
更新日期：2009-06-01 00:00:00
abstract：:Highly purified human lactate dehydrogenases I and V were assayed in 17 different buffers, at a variety of reaction pH's. Diethanolamine and 2-amino-2-methyl-1,3-propanediol provided the best measurements of the enzyme, assayed lactate-to-pyruvate. However, the commercial preparation of 2-amino-2-methyl-1,3-propanedio...
journal_title：Clinical chemistry
pub_type： 杂志文章
doi：
更新日期：1976-11-01 00:00:00
abstract：:Discrepancies among different methods for assaying human growth hormone have been described in various studies. The two major sources of discordant results are the heterogeneity of the antibodies and the different standardization bases used by the assay manufacturers. We propose standardizing assays with 22-kDa biosyn...
journal_title：Clinical chemistry
pub_type： 杂志文章
doi：
更新日期：1992-10-01 00:00:00
abstract：:We present a case of advanced ovarian carcinoma associated with high concentrations of serum and urine amylase. Biochemical analysis to elucidate the nature and origin of the hyperamylasemia identified seven amylase isoenzymes, of which five appeared to be distinct from normal salivary and pancreatic amylase. We discu...
journal_title：Clinical chemistry
pub_type： 杂志文章
doi：
更新日期：1979-06-01 00:00:00
abstract：:Backpropagation neural networks are a computer-based pattern-recognition method that has been applied to the interpretation of clinical data. Unlike rule-based pattern recognition, backpropagation networks learn by being repetitively trained with examples of the patterns to be differentiated. We describe and analyze t...
journal_title：Clinical chemistry
pub_type： 临床试验,杂志文章,随机对照试验
doi：
更新日期：1993-09-01 00:00:00
abstract：BACKGROUND:The aim of our present study was to establish new reference intervals for thyrotropin (TSH) and thyroid hormones based on National Academy of Clinical Biochemistry (NACB) criteria and regular thyroid ultrasonography. We also assessed the effect of potentially confounding factors to modulate the limits of the...
journal_title：Clinical chemistry
pub_type： 杂志文章
doi：10.1373/clinchem.2004.047399
更新日期：2005-08-01 00:00:00
abstract：BACKGROUND:alpha(1)-Antitrypsin is the major plasma serine protease inhibitor. Its deficiency is mainly associated with the alleles PI*S and PI*Z and can lead to obstructive lung disease in adults and to liver cirrhosis during childhood. METHODS:A multiplex PCR method has been established that uses two sets of primers...
journal_title：Clinical chemistry
pub_type： 杂志文章
doi：
更新日期：2000-02-01 00:00:00
abstract：BACKGROUND:Reports of the use of multiplex enzyme assay screening for Pompe disease, Fabry disease, Gaucher disease, Niemann-Pick disease types A and B, and Krabbe disease have engendered interest in the use of this assay in newborn screening. We modified the assay for high-throughput use in screening laboratories. ME...
journal_title：Clinical chemistry
pub_type： 杂志文章
doi：10.1373/clinchem.2008.104711
更新日期：2008-10-01 00:00:00
abstract：:To study the effect of fatty acid chain saturation on the fluorescence polarization assay as a measure of fetal lung maturity, we used purified phospholipids isolated from human amniotic fluid and various commercial phospholipids. We found that the fluorescence polarization value decreased as the concentration of unsa...
journal_title：Clinical chemistry
pub_type： 杂志文章
doi：
更新日期：1986-03-01 00:00:00
abstract：:Use of immunoassays that do not detect endogenous digoxin-like immunoreactive factors (DLIF) in serum significantly improves the between-assay correlation of digoxin results for patients. We investigated five different immunoassay methods (Abbott, Clinical Assays, Corning, Du Pont, and Syva), measuring digoxin by all ...
journal_title：Clinical chemistry
pub_type： 杂志文章
doi：
更新日期：1987-06-01 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：:To correct the results of a radioimmunoassay for beta-thyrotropin (TSH) subunit by eliminating the proportion ascribable to intact TSH, we have devised a method that experimentally reproduces the conditions under which the interference develops. Beta-TSH subunit was assayed in several preparations containing known con...
journal_title：Clinical chemistry
pub_type： 杂志文章
doi：
更新日期：1987-05-01 00:00:00
abstract：:Comparison of two methods for determining a substance is a common procedure in clinical chemistry. Almost without exception, normal theory statistics are used with the tacit assumption that the data under test show gaussian distributions. Experience has led us to question this assumption for populations of differences...
journal_title：Clinical chemistry
pub_type： 杂志文章
doi：
更新日期：1975-03-01 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:To allow multianalyte binding assays, we have developed a novel polystyrene microtiter plate containing 24 main wells, each divided into 7 subwells. We explored its clinical potential by developing a PCR-chemiluminescent immunoassay (PCR-CLEIA) for simultaneous detection and typing of seven high oncogenic ri...
journal_title：Clinical chemistry
pub_type： 临床试验,杂志文章
doi：
更新日期：2002-10-01 00:00:00
abstract：:A method is described for separating antibody-bound from free fractions in ligand assays by column affinity chromatography, and its application to radioimmunoassay of choriomammotropin. In the method, 70 x 10 mm (i.d.) polypropylene columns containing about 150 mg of immunosorbent (goat anti-rabbit gamma-globulins cov...
journal_title：Clinical chemistry
pub_type： 杂志文章
doi：
更新日期：1981-06-01 00:00:00
abstract：BACKGROUND:Prostate-specific antigen (PSA) is a valuable prostatic cancer biomarker that is now widely used for population screening, diagnosis, and monitoring of patients with prostate cancer. Despite the voluminous literature on this biomarker, relatively few reports have addressed the issue of its physiological func...
journal_title：Clinical chemistry
pub_type： 杂志文章,评审
doi：
更新日期：2000-07-01 00:00:00
abstract：:We have evaluated Fructosamine Test-Plus, a commercial fructosamine assay based on the reduction of nitro-blue tetrazolium dye in alkaline buffer (Clin Chem 1985;31:1550-4), modified by including a detergent and uricase in the reagent, by changing the concentrations of buffer and dye, and by changing the approach to p...
journal_title：Clinical chemistry
pub_type： 杂志文章
doi：
更新日期：1991-04-01 00:00:00
