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 profiles are fitted to the function for the CV of proportions, which yields the number of theoretically differentiated leukocytes. Differences between fitted curves are evaluated for statistical significance by the F-test. As an example, we compared the precision of two hematology analyzers, a flow-cytometric technique involving fluorescence-labeled monoclonal antibodies, and the manual differential. We were able to establish definite differences in precision between different analyzers and different leukocyte classes. Our data also indicated that conventional within-run imprecision studies may completely misjudge analyzer precision. Furthermore, we could demonstrate that the precision of analyzers that analyze a fixed amount of blood rather than a fixed number of leukocytes is strongly influenced by the leukocyte count of the sample, leading to high imprecision for leukopenic samples. We believe the proposed procedure is a useful addition to currently used protocols; it yields clear results and creates a statistical basis of comparison between various instruments and techniques of differentiation.
journal_name
Clin Chemjournal_title
Clinical chemistryauthors
Hübl W,Tlustos L,Bayer PMsubject
Has Abstractpub_date
1996-07-01 00:00:00pages
1068-73issue
7eissn
0009-9147issn
1530-8561journal_volume
42pub_type
杂志文章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 polymorphism in the human prostate-specific glandular kallikrein (hKLK2) gene was described by direct sequencing (by PCR) of genomic DNAs isolated from prostatic cancer tissue, benign prostatic hyperplasia tissue, and blood leukocyte specimens. Results showed two forms of human prostate-specific glandular kallikrein...
journal_title:Clinical chemistry
pub_type: 杂志文章
doi:
更新日期:1997-02-01 00:00:00
abstract::We evaluated the HemoCue beta-Glucose Photometer system for use in our neonatal intensive care unit by assaying 178 heparinized whole-blood samples obtained by heel stick. The required sample size is 5 microL. Plasma glucose was analysed by a glucose oxidase/oxygen electrode methodology. Across the glucose range of 1....
journal_title:Clinical chemistry
pub_type: 杂志文章
doi:
更新日期:1993-11-01 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::We compared results for measurements of creatine kinase isoenzyme MB (CK-MB) by immunoinhibition vs immunoprecipitation, using sera from 53 normal healthy individuals, 55 patients with increased CK-MB associated with acute myocardial infarction, and 42 patients whose blood exhibited one or more abnormal forms of CK by...
journal_title:Clinical chemistry
pub_type: 杂志文章
doi:
更新日期:1982-10-01 00:00:00
abstract::Plasma concentrations of delta-9-tetrahydrocannabinol, the principal psychoactive cannabinoid in marijuana, decline to values substantially less than 1 microgram/L within a few hours after a subject has smoked a marijuana cigarette. Using a single-quadrupole gas chromatograph-mass spectrometer (GC/MS) operated in the ...
journal_title:Clinical chemistry
pub_type: 杂志文章
doi:
更新日期:1991-12-01 00:00:00
abstract::This new assay procedure for diaphorase eliminates problems of high blank rates and nonlinear kinetics associated with other methods. The dye thiazolyl blue tetrazolium bromide is reduced in the presence of NADH and diaphorase to yield a colored formazan, which as maximum absorbance at 560 nm. ...
journal_title:Clinical chemistry
pub_type: 杂志文章
doi:
更新日期:1979-12-01 00:00:00
abstract::A "high-performance" liquid-chromatographic procedure for 5-hydroxy-3-indoleacetic acid is described and compared with a colorimetric method in which 1-nitroso-2-naphthol is used. The analyte and an internal standard, p-nitrobenzoic acid, were extracted into diethyl ether from urine at pH 4.0 (acidified with HCl) to w...
journal_title:Clinical chemistry
pub_type: 杂志文章
doi:
更新日期:1980-06-01 00:00:00
abstract:BACKGROUND:The determination of cellular beta-galactocerebrosidase activity is an established procedure to diagnose Krabbe disease and monitor the efficacy of gene/stem cell-based therapeutic approaches aimed at restoring defective enzymatic activity in patients or disease models. Current biochemical assays for beta-ga...
journal_title:Clinical chemistry
pub_type: 杂志文章
doi:10.1373/clinchem.2008.115873
更新日期:2009-03-01 00:00:00
abstract::We determined approximately 15,000 laboratory values in 236 individuals between the ages of 60 and 90 y, 22 individuals between 90 and 99 y, and 69 individuals greater than or equal to 100 y, and compared these with values in young adults. We tested 47 different analytes in the 60-90-y group and 93 analytes in the gre...
journal_title:Clinical chemistry
pub_type: 杂志文章
doi:
更新日期:1992-06-01 00:00:00
abstract:BACKGROUND:The resurgence of the parasitic disease schistosomiasis calls for more efficient diagnostic tests. We developed a rapid, simple, portable, and sensitive immunoagglutination assay that uses SiO(2) particles and quartz crystal microbalance (QCM) for quantifying Schistosoma japonicum (Sj) antibodies (SjAb). ME...
journal_title:Clinical chemistry
pub_type: 杂志文章
doi:10.1373/clinchem.2006.071555
更新日期:2006-11-01 00:00:00
abstract::We describe a "high-performance" liquid-chromatographic assay for measuring ritalinic acid in 300 muL of serum. The procedure includes adsorption of ritalinic acid and internal standard (alpha,alpha-dimethyl-beta-emthylsuccinimide) from serum onto charcoal, from which both compounds are eluted with methanol. The metha...
journal_title:Clinical chemistry
pub_type: 杂志文章
doi:
更新日期:1979-01-01 00:00:00
abstract::We measured three renal tubular brush-border enzymes (lactate dehydrogenase, LDH, EC 1.1.1.27; gamma-glutamyltransferase, GGT, EC 2.3.2.2; and alkaline phosphatase, AP, EC 3.1.3.1) in morning urine samples from 48 healthy subjects to check whether different storage times and temperatures could modify enzyme concentrat...
journal_title:Clinical chemistry
pub_type: 杂志文章
doi:
更新日期:1991-08-01 00:00:00
abstract::We evaluated the effect on drug concentration of the duration of sample storage in three different tubes for blood collection: SST (Becton Dickinson), AutoSep (Terumo), and Microvette (Sarstedt), all of which contain an inert barrier (e.g., gel) for cleaner separation of serum from coagulum during centrifugation. With...
journal_title:Clinical chemistry
pub_type: 杂志文章
doi:
更新日期:1984-03-01 00:00:00
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::A gas-chromatographic method for urinary organic acid analysis is described, designed to be used routinely for the diagnosis of organic aciduria. It involves extraction of urine with ethyl acetate, dehydration of extract residues, and trimethylsilylation. Organic acids are identified by using an extensive list of rete...
journal_title:Clinical chemistry
pub_type: 杂志文章
doi:
更新日期:1980-12-01 00:00:00
abstract:BACKGROUND:Fetuin-A inhibits inflammation and has a protective effect against myocardial ischemia. Its deficiency has been found to be associated with cardiovascular death in patients with end-stage renal failure disease. We investigated the association between plasma fetuin-A and clinical outcome after ST-elevation ac...
journal_title:Clinical chemistry
pub_type: 杂志文章
doi:10.1373/clinchem.2006.084947
更新日期:2007-10-01 00:00:00
abstract::The basic theory of thyroxin-analog-based radioimmunoassays for free thyroxin has been extended to evaluate definitively the effects arising from residual binding of the tracer analog to serum proteins. Using experimentally determined binding constants and computer simulation techniques, we studied the effects of thyr...
journal_title:Clinical chemistry
pub_type: 杂志文章
doi:
更新日期:1985-10-01 00:00:00
abstract:BACKGROUND:Measurement of hemoglobin A1c (HbA1c) in the blood is integral to and essential for the treatment of patients with diabetes mellitus. HbA1c reflects the mean blood glucose concentration over the preceding 8 to 12 weeks. Although the clinical value of HbA1c was initially limited by large differences in result...
journal_title:Clinical chemistry
pub_type: 杂志文章,评审
doi:10.1373/clinchem.2018.296962
更新日期:2019-07-01 00:00:00
abstract:BACKGROUND:Hyperglycosylated human chorionic gonadotropin (hCG-h) contains larger and more complex carbohydrate chains than regular human chorionic gonadotropin (hCG). hCG-h is thought to be the major form of hCG produced by testicular cancers and it has been suggested to play a key role in tumor invasion, but studies ...
journal_title:Clinical chemistry
pub_type: 杂志文章
doi:10.1373/clinchem.2012.183723
更新日期:2012-07-01 00:00:00
abstract:BACKGROUND:Because reference values for vitamin B(12) concentrations and vitamin B(12)-binding capacities for pregnant women have not been established, the reference values for nonpregnant women are often applied to assess vitamin B(12) status. The aim of the present study was to describe ranges of biochemical indices ...
journal_title:Clinical chemistry
pub_type: 杂志文章
doi:
更新日期:2002-06-01 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::Urinary polyamines were measured by a fluorometric thin-layer chromatographic technique in samples collected daily throughout a single menstrual cycle by each of 13 healthy women. Polyamine excretion fluctuated considerably, but excretion of putrescine, spermidine, and spermine combined was consistently greatest durin...
journal_title:Clinical chemistry
pub_type: 杂志文章
doi:
更新日期:1978-05-01 00:00:00
abstract:BACKGROUND:Formalin-fixed paraffin-embedded (FFPE) tumor material represents a valuable resource for the analysis of RNA-based biomarkers, both in research laboratories and in routine clinical testing. A robust and automated RNA-extraction method with a high sample throughput is required. METHODS:We evaluated extracti...
journal_title:Clinical chemistry
pub_type: 杂志文章
doi:10.1373/clinchem.2008.122572
更新日期:2009-09-01 00:00:00
abstract::The biological variability of total cholesterol (TC), triglycerides (TG), high-density lipoprotein cholesterol (HDL-C), and calculated low-density lipoprotein cholesterol (LDL-C) was determined in three serial (monthly) capillary and venous specimens from 83 subjects. The analytes were quantified with a desktop analyz...
journal_title:Clinical chemistry
pub_type: 杂志文章
doi:
更新日期:1996-12-01 00:00:00
abstract::We evaluated the enzymic mechanism by which 3-keto butylidene-beta-2-chloro-4-nitrophenyl maltopentaoside (3KB-G5-CNP) serves as a substrate for serum pancreatic (p-) and salivary (s-) amylases. In aliquots of the reaction mixture, three kinds of beta-2-chloro-4-nitrophenyl oligosaccharides (glucose, maltoside, and ma...
journal_title:Clinical chemistry
pub_type: 杂志文章
doi:
更新日期:1991-08-01 00:00:00
abstract::The enzymatic determination of serum uric acid by use of uricase, catalase, and aldehyde dehydrogenase according to Haeckel [J. Clin. Chem. Clin Biochem. 14, 101 (1976)] showed interferences from ethanol-converting enzymes, which are present in some patients' sera. We have identified these enzymes as alcohol dehydroge...
journal_title:Clinical chemistry
pub_type: 杂志文章
doi:
更新日期:1979-04-01 00:00:00
abstract::Considerable evidence has accrued in the last two decades to support the hypothesis that alterations in serotonergic neuronal function in the central nervous system occur in patients with major depression. These findings include the following: (a) reduced cerebrospinal fluid (CSF) concentrations of 5-hydroxyindoleacet...
journal_title:Clinical chemistry
pub_type: 杂志文章,评审
doi:
更新日期:1994-02-01 00:00:00
abstract::We describe a ratio gas-chromatographic method for determination of cortisol production rate by measuring the isotope dilution of urinary cortisol metabolites. The method was calibrated by analyzing [3H]tetrahydrocortisol and [3H]tetrahydrocortisone of known specific activities. Results are reasonably well reproducibl...
journal_title:Clinical chemistry
pub_type: 杂志文章
doi:
更新日期:1977-03-01 00:00:00
abstract::This compendium represents what we believe to be the most current and reliable pharmacological data on anticonvulsant drugs. The information presented is derived from determinations of the drugs in plasma or serum by gas--liquid chromatography in studies of the efficacy of anti-epileptic agents. We present information...
journal_title:Clinical chemistry
pub_type: 杂志文章
doi:
更新日期:1977-11-01 00:00:00