Abstract：
:We compared the performance of an automated assay of creatine kinase MB isoenzyme (CK-MB) mass (Stratus) with that of a CK-MB enzymatic assay routinely used at our institutions. Both of these assays use the same CK-MB-specific monoclonal antibody to immunocapture CK-MB, thus providing a direct means of comparing a mass assay with an activity assay. Routine CK-MB measurements for 206 samples within the analytical range of both assays revealed the following relationship: Stratus (micrograms/L) = 0.67 (activity U/L) + 0.18 (r = 0.95, Sx.y = 4.45). The linearity, sensitivity, and precision of the Stratus assay were acceptable for routine clinical use. Icteric, lipemic, and hemolyzed samples do not interfere with the assay. During our evaluation we identified a single, clinically significant false-positive sample. Because this patient had alkaline phosphatase values greater than 1100 U/L, we investigated additional samples with increased activities of alkaline phosphatase and found that samples from 12 of 23 patients selected for alkaline phosphatase values greater than 460 U/L produced falsely increased CK-MB values. We determined that a membrane-associated, high-molecular-mass form of alkaline phosphatase was a cause of these falsely increased values and instituted an approach to identify falsely increased Stratus CK-MB values. Samples from 23 of 1933 patients were falsely increased, the increase being clinically significant in samples from 14 of these patients. Consultation with the manufacturer resulted in the successful reformulation of the substrate/wash solution to minimize interferences from high-molecular-mass forms of alkaline phosphatase.
journal_name
Clin Chemjournal_title
Clinical chemistryauthors
Butch AW,Goodnow TT,Brown WS,McClellan A,Kessler G,Scott MGsubject
Has Abstractpub_date
1989-10-01 00:00:00pages
2048-53issue
10eissn
0009-9147issn
1530-8561journal_volume
35pub_type
杂志文章abstract：:Five genetic defects have been established as risk factors for venous thrombosis. Three are protein C, protein S, and antithrombin deficiencies, defects in the anticoagulant pathways of blood coagulation. Together they can be found in approximately 15% of families with inherited thrombophilia. Their laboratory diagnos...
journal_title：Clinical chemistry
pub_type： 杂志文章,评审
doi：
更新日期：1997-09-01 00:00:00
abstract：BACKGROUND:Paraoxonase may protect lipoproteins and cell membranes from peroxidation, and alterations in the activity of this enzyme have been associated with some chronic diseases. Serum paraoxonase appears to be mainly under genetic control, but some studies suggest that environmental factors may also modulate its ac...
journal_title：Clinical chemistry
pub_type： 杂志文章
doi：10.1373/49.9.1491
更新日期：2003-09-01 00:00:00
abstract：:In this efficient extraction and isocratic liquid-chromatographic procedure for measuring eight antidepressant drugs in serum (amoxapine, 8-hydroxyamoxapine, doxepin, desmethyldoxepin, imipramine, desipramine, amitriptyline, and nortriptyline), they are extracted from serum as a group by use of disposable solid-phase ...
journal_title：Clinical chemistry
pub_type： 杂志文章
doi：
更新日期：1984-11-01 00:00:00
abstract：:We investigated two techniques of immunoblotting--the Western blot and the dot blot--for use in detecting prostatic acid phosphatase (PAP, EC 3.1.3.2). We used polyclonal antisera to human PAP, produced in rabbits by hyperimmunization with purified PAP, and PAP-specific monoclonal antibodies in the immunoenzymatic pro...
journal_title：Clinical chemistry
pub_type： 杂志文章
doi：
更新日期：1986-10-01 00:00:00
abstract：:Using image-analyzing equipment, we measured the effect of quinidine on the activity of naphthol AS-D chloroacetate esterase, alpha-naphthyl butyrate esterase, alpha-naphthyl acetate esterase, and acid phosphatase in individual cells of a human Hep G2 hepatoma cell line. The impact of the drug on the morphology of the...
journal_title：Clinical chemistry
pub_type： 杂志文章
doi：
更新日期：1988-03-01 00:00:00
abstract：BACKGROUND:Whether low plasma 25-hydroxyvitamin D concentrations cause osteoporotic fractures is unclear. We tested the hypothesis that low plasma 25-hydroxyvitamin D concentrations are associated with increased risk of osteoporotic fractures using a Mendelian randomization analysis. METHODS:We genotyped 116 335 rando...
journal_title：Clinical chemistry
pub_type： 杂志文章
doi：10.1093/clinchem/hvaa049
更新日期：2020-05-01 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：:We developed a radioimmunoassay with a gamma-emitting radioligand to measure androstenedione in human serum and in dried blood-spot samples from newborns. Antisera were raised in rabbits against androstenedione linked to bovine serum albumin at positions 3, 6, or 11 on the steroid nucleus. Radioligands were prepared b...
journal_title：Clinical chemistry
pub_type： 杂志文章
doi：
更新日期：1989-08-01 00:00:00
abstract：:We compared the analytical performance of the Kodak Ektachem XR700 assays of iron (Fe) and total iron-binding capacity (TIBC) with that of a conventional ferrozine assay (performed with a Cobas-Bio) and occasionally with that of atomic-absorption spectrometry (AAS). The correlation was modest between Kodak and Cobas-B...
journal_title：Clinical chemistry
pub_type： 杂志文章
doi：
更新日期：1990-10-01 00:00:00
abstract：BACKGROUND:ADB-PINACA and its 5-fluoropentyl analog 5F-ADB-PINACA are among the most potent synthetic cannabinoids tested to date, with several severe intoxication cases. ADB-PINACA and 5F-ADB-PINACA have a different legal status, depending on the country. Synthetic cannabinoid metabolites predominate in urine, making ...
journal_title：Clinical chemistry
pub_type： 杂志文章
doi：10.1373/clinchem.2016.267575
更新日期：2017-05-01 00:00:00
abstract：:The human ras gene plays a fundamental role in the transduction of extracellular signals to the nucleus, thereby regulating cell growth and differentiation. Point mutations in the ras gene convert it into a transforming oncogene that has been found in many solid and hematologic malignancies. We describe a rapid and se...
journal_title：Clinical chemistry
pub_type： 杂志文章
doi：
更新日期：1994-05-01 00:00:00
abstract：:In this clinically useful enzyme immunoassay of digoxin in serum, we mix sample, beta-galactosidase-labeled digoxin, and anti-digoxin Fab fragments for 30 min at room temperature, then use Sepharose-bound second antibody for phase separation, and measure the unbound enzyme activity directly in the supernate of the equ...
journal_title：Clinical chemistry
pub_type： 杂志文章
doi：
更新日期：1986-01-01 00:00:00
abstract：:We evaluated the performance of two homogeneous assays for quantifying HDL cholesterol (HDL-C) and compared them with the phosphotungstic acid (PTA)/ MgCl2 assay. Both homogeneous HDL-C assays were precise, having a within-run CV of < 1.20% and a between-run CV of < 4.07%. The HDL-C values (y) measured by the two homo...
journal_title：Clinical chemistry
pub_type： 杂志文章
doi：
更新日期：1997-06-01 00:00:00
abstract：BACKGROUND:Rapid intraoperative parathyroid hormone (PTH) measurements are an important prerequisite for minimally invasive parathyroidectomy, serving as a feasible marker for "cure" because of the short half-life of PTH. Because automated analysis may facilitate monitoring, two automated PTH assays were compared with ...
journal_title：Clinical chemistry
pub_type： 杂志文章
doi：
更新日期：2002-10-01 00:00:00
abstract：BACKGROUND:There is extended urinary excretion of Δ(9)-tetrahydrocannabinol (THC), 11-hydroxy-THC (11-OH-THC), and 11-nor-9-carboxy-THC (THCCOOH) in abstinent frequent cannabis smokers. We characterized THC, 11-OH-THC, THCCOOH, cannabidiol, cannabinol, THC-glucuronide, and THCCOOH-glucuronide disposition in urine of fr...
journal_title：Clinical chemistry
pub_type： 临床试验,杂志文章
doi：10.1373/clinchem.2013.214106
更新日期：2014-02-01 00:00:00
abstract：:In this simple and low-cost radioimmunoassay (RIA) procedure for thyroxin (T4), ethacridine (6,9-diamino-2-ethoxyacridine lactate; Rivanol) is used to separate antibody-bound ligand and free ligand. This acridine dye precipitates free T4 not bound to antibody. At pH 8.6, it precipitates more than 90% of 125I-labeled T...
journal_title：Clinical chemistry
pub_type： 杂志文章
doi：
更新日期：1983-11-01 00:00:00
abstract：:The commonly used methods of assessing the precision of the automated leukocyte differential have certain drawbacks that affect the validity and comparability of results. In the present report, we introduce a procedure based on building precision profiles from a large number of within-run imprecision experiments. The ...
journal_title：Clinical chemistry
pub_type： 杂志文章
doi：
更新日期：1996-07-01 00:00:00
abstract：:Serum folate, pteroylglutamic acid standards, and N-5-methyltetrahydrofolate standards extract differently during sample preparation for radiometric assay. B/B0 values for each material were determined before and after an alkaline extraction procedure. Serum folate most closely resembled N-5-methyltetrahydrofolate sta...
journal_title：Clinical chemistry
pub_type： 杂志文章
doi：
更新日期：1981-04-01 00:00:00
abstract：:We describe a new multilayer immunoassay element for the determination of haptens in undiluted serum and plasma. Polysaccharide layers are coated onto a plastic base. The signal layer contains an immobilized antibody and a fluorescent-labeled hapten. A second layer, containing a pigment, acts as an optical screen. Sam...
journal_title：Clinical chemistry
pub_type： 杂志文章
doi：
更新日期：1989-09-01 00:00:00
abstract：:We describe a procedure for determining thiocyanate in plasma with a Technicon AutoAnalyzer I, modified with a 50-mm tubular flow cell to increase the sensitivity of thiocyanate detection. The procedure is suitable for distinguishing cigarette smokers from non-smokers, the mean for smokers being 151 (SD 43) micromol/L...
journal_title：Clinical chemistry
pub_type： 杂志文章
doi：
更新日期：1980-03-01 00:00:00
abstract：BACKGROUND:Biochemical markers of bone turnover can provide prognostic information about the risk of osteoporotic fracture and are useful tools for monitoring efficacy of antiresorptive therapy. A serum-based automated assay may be of better clinical value than urinary markers because of lower imprecision and day-to-da...
journal_title：Clinical chemistry
pub_type： 杂志文章
doi：
更新日期：2001-04-01 00:00:00
abstract：:The clinical relevance of likelihood ratios (L-values) for revising the physician's diagnostic probabilities has been recognized. However, the calculation of L-values, particularly in the case of quantitative or mixed quantitative-binary test results, raises problems that have not yet been addressed. Based on a very g...
journal_title：Clinical chemistry
pub_type： 杂志文章
doi：
更新日期：1982-05-01 00:00:00
abstract：:We describe estimation of total cortisol in serum by HPLC. Incorporation of a new technique to totally automate sample preparation decreases costs. The benefits of HPLC ensure that interferences from other steroids are avoided. The method can also be used to estimate concentrations of other glucocorticoids in serum. ...
journal_title：Clinical chemistry
pub_type： 杂志文章
doi：
更新日期：1988-09-01 00:00:00
abstract：:The molar absorptivity of unconjugated bilirubin in caffeine reagent is independent of the protein matrix. This finding, together with the simplicity of a dilution step for direct spectrophotometry, will improve the calibration methods of bilirubin and make them more nearly accurate. This is encouraging for the develo...
journal_title：Clinical chemistry
pub_type： 杂志文章
doi：
更新日期：1986-07-01 00:00:00
abstract：:We describe an enzyme-linked two-site immunoassay for quantitation of intact insulin in human serum and plasma. The method uses two murine monoclonal antibodies that bind to two different epitopes on the insulin molecule. The immunoassay is specific. Human proinsulin is not bound by the antibodies, and the binding of ...
journal_title：Clinical chemistry
pub_type： 杂志文章
doi：
更新日期：1993-04-01 00:00:00
abstract：:We describe a simple, rapid fluorometric assay for separate quantitative analysis of procainamide and N-acetylprocainamide in mixtures. The effective lenear range (fluorescence vs. concentration) in serum is 0.1 to 10.0 mg/liter, regardless of the ratio (by weight) of the two drugs from 1:10 to 10:1. Analytical recove...
journal_title：Clinical chemistry
pub_type： 杂志文章
doi：
更新日期：1975-12-01 00:00:00
abstract：BACKGROUND:Vascular age is an emerging health indicator and predictor of end-organ damage to the heart, brain, and kidney. Although there have been many review publications concerning risk factors for vascular aging, most include cross-sectional epidemiological studies, limiting inferences about temporality. There is a...
journal_title：Clinical chemistry
pub_type： 杂志文章,评审
doi：10.1373/clinchem.2018.287623
更新日期：2019-01-01 00:00:00
abstract：BACKGROUND:An accelerated stability model based on the Arrhenius Equation can be used to estimate stability of diagnostic reagents. Here we review 3 examples in which the model does not accurately predict the stability of diagnostic reagents. METHODS:We prepared several pilot lots of quality controls materials contain...
journal_title：Clinical chemistry
pub_type： 杂志文章
doi：10.1093/clinchem/hvaa282
更新日期：2020-12-04 00:00:00
abstract：:The historical development of a charitable children's hospital and the evolution of its clinical laboratory are presented. With the appearance of practical quantitative blood chemistry tests in the period between the two World Wars, applications to pediatrics were hampered by the need for ultramicro procedures then un...
journal_title：Clinical chemistry
pub_type： 历史文章,杂志文章
doi：
更新日期：2000-07-01 00:00:00
abstract：:Clinicians confront the classical problem of decision making under uncertainty, but a universal procedure by which they deal with this situation, both in diagnosis and therapy, can be defined. This consists in the choice of a specific course of action from available alternatives so as to reduce uncertainty. Formal ana...
journal_title：Clinical chemistry
pub_type： 杂志文章,评审
doi：
更新日期：1995-08-01 00:00:00
