Abstract：
:A region consisting of 19 clinical laboratories harmonized their calibration of seven common enzymes by using fresh patient-pool sera. One of the laboratories was chosen to act as Regional Reference Laboratory (RRL). This laboratory used internationally accepted (mostly IFCC) methods at 37 degrees C, with an intralaboratory CV < or = 2.5%. First, the reference ranges of the RRL were verified by analysis of a reference population and calculation of the results by a parametric method. Next, all laboratories, including the RRL, received six patient-pool sera and analyzed them at the same time on the same date. Enzyme calibration factors at each laboratory were converted on the basis of the slope, and occasionally the intercept, of regression analysis with the RRL and the individual laboratory. Before harmonization, the interlaboratory CVs varied from 16.9% to 61.6%. After harmonization, CVs decreased to between 5.0% and 9.5%. These results proved to be reproducible over a period of more than a year. Using internationally accepted inaccuracy and imprecision criteria, the achieved interlaboratory CVs permit the use of one set of reference ranges by all participating laboratories. Certified Reference Materials were analyzed, resulting in interlaboratory CVs as low as those achieved with patient-pool sera. These materials can act as commutable reference preparations, except for creatine kinase.
journal_name
Clin Chemjournal_title
Clinical chemistryauthors
Franck PF,Steen G,Lombarts AJ,Souverijn JH,van Wermeskerken RKsubject
Has Abstractpub_date
1998-03-01 00:00:00pages
614-21issue
3eissn
0009-9147issn
1530-8561journal_volume
44pub_type
杂志文章,多中心研究abstract：:I present the general pattern relationship between (a) plasma fibrinogen and cholinesterase activity and (b) plasma fibrinogen and hemoglobin, in 250 and 310 hospitalized adults, respectively. Although responses of cholinesterase were often unrelated to fibrinogen, when its activity in plasma was depressed, above-norm...
journal_title：Clinical chemistry
pub_type： 杂志文章
doi：
更新日期：1977-01-01 00:00:00
abstract：BACKGROUND:Uremic syndrome is the consequence of the retention of solutes usually cleared by the healthy kidneys. p-Cresol can be considered a prototypic protein-bound uremic toxin. It is conceivable, analogous with drugs, that the non-protein-bound fraction of p-cresol exerts toxicity. This aspect had never been evalu...
journal_title：Clinical chemistry
pub_type： 杂志文章
doi：10.1373/49.3.470
更新日期：2003-03-01 00:00:00
abstract：:We have developed a fully enzymatic method to measure 1,5 anhydro-D-glucitol (1,5-AG) in serum through use of pyranose oxidase (PROD: EC 1.1.3.10), glucokinase (EC 2.7.1.2), and an ATP-regenerating system. In a previous report (Clin Chem 1989;35:2039-43) the glucose interfering with the measurement of 1,5-AG was remov...
journal_title：Clinical chemistry
pub_type： 杂志文章
doi：
更新日期：1994-11-01 00:00:00
abstract：:We evaluated the technical performance of the Ciba Corning ACS:180 automated immunoassay system for the following analytes: thyroid-stimulating hormone, free thyroxine, luteinizing hormone, follicle-stimulating hormone, prolactin, human chorionic gonadotropin, carcino-embryonic antigen, and prostate-specific antigen. ...
journal_title：Clinical chemistry
pub_type： 杂志文章
doi：
更新日期：1994-03-01 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：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：:Autocorrelation of clinical chemistry quality-control (Q/C) measurements causes one of the basic assumptions underlying the use of Levey-Jennings control charts to be violated and performance to be degraded. This is the requirement that the observations be statistically independent. We present a proposal for a new app...
journal_title：Clinical chemistry
pub_type： 杂志文章
doi：
更新日期：1988-07-01 00:00:00
abstract：:Two-hour postprandial specimens have a -14% proportional bias for lipoprotein(a) [Lp(a)], a -0.035 g/L systematic bias for apolipoprotein (apo) A-I, and a -9% proportional bias for apo B, compared with values in 12-h fasting specimens. Although a physiological hemodilution appears to account for a portion of these bia...
journal_title：Clinical chemistry
pub_type： 杂志文章
doi：
更新日期：1992-03-01 00:00:00
abstract：:During phase I/II clinical trials of sirolimus (rapamycin; SRL), therapeutic drug monitoring was performed with a multistep liquid-liquid extraction of 1-mL aliquots of whole blood followed by reversed-phase HPLC with ultraviolet detection. Blood was sampled according to a standardized protocol and clinical status. SR...
journal_title：Clinical chemistry
pub_type： 杂志文章
doi：
更新日期：1996-12-01 00:00:00
abstract：:We evaluated and compared five commercial radioimmunoassay kits with a standard counter-immunoelectrophoretic assay for the measurement of prostatic acid phosphatase in serum. Four of the five radioimmunoassays performed as described by the supplier with respect to sensitivity, stability, precision, linearity, analyti...
journal_title：Clinical chemistry
pub_type： 杂志文章
doi：
更新日期：1981-10-01 00:00:00
abstract：BACKGROUND:Astilbin is a flavonoid isolated from the rhizome of Smilax glabra. In a previous study, we revealed its unique immunosuppressive activity, a selective inhibition against activated T lymphocytes. This characteristic of astilbin is beneficial for the treatment of human immune diseases. METHODS:We incubated a...
journal_title：Clinical chemistry
pub_type： 杂志文章
doi：10.1373/clinchem.2006.077297
更新日期：2007-03-01 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：:This method for determining aluminum in human serum involves electrothermal atomic absorption spectrophotometry. A longer drying time allows less pre-dilution of the sample, and the method also includes a flush cycle after atomization. Standard-addition methodology is used to eliminate matrix effects and the need for ...
journal_title：Clinical chemistry
pub_type： 杂志文章
doi：
更新日期：1983-06-01 00:00:00
abstract：:We describe a discrete automated radioimmunoassay system for determining choriomammotropin (placental lactogen) in human serum. With the present system it can be measured in as many as 37 unknown sera (50 muL) and three quality-control sera, in duplicate, within 1.5 h. The time required for sample preparation, incubat...
journal_title：Clinical chemistry
pub_type： 杂志文章
doi：
更新日期：1979-01-01 00:00:00
abstract：:To produce bispecific antibodies (BiAbs) for enzyme immunoassay (EIA) to replace antibody-enzyme conjugates, we developed a panel of 8-azaguanine/ouabain-resistant anti-urease variant hybridoma cell lines for use in hybridoma-hybridoma fusions. These variants represent mouse immunoglobulin subclasses IgM, IgG1, IgG2a,...
journal_title：Clinical chemistry
pub_type： 杂志文章
doi：
更新日期：1988-09-01 00:00:00
abstract：:Serum free thyroxin (FT4) was determined in 40 patients with various nonthyroidal illnesses. We studied seven methods: (1) a free thyroxin index calculated from total T4 and triiodothyronine resin uptake; (2) a free T4 index determined by enzyme inhibitor assays (Abbott's "Tetrazyme" and "Thyrozyme"); (3) a free T4 in...
journal_title：Clinical chemistry
pub_type： 杂志文章
doi：
更新日期：1983-12-01 00:00:00
abstract：:The reaction of 5,5'-dithiobis(2-nitrobenzoic acid) (DTNB, Ellman's reagent) with thiols is sensitive to daylight, in particular to ultraviolet radiation at wavelengths around 325 nm. Exposure to light at the absorbance maximum of the yellow product (the thionitrobenzoate ion) at 410 nm had no effect on the reaction. ...
journal_title：Clinical chemistry
pub_type： 杂志文章
doi：
更新日期：1987-10-01 00:00:00
abstract：:Several factors can limit the use of therapeutic drug monitoring (TDM) for cancer chemotherapeutic agents, including poorly defined concentration-effect relationships for many antineoplastic agents. This is further complicated by cancer being a highly heterogeneous group of diseases, each of which may have a unique co...
journal_title：Clinical chemistry
pub_type： 杂志文章
doi：
更新日期：1998-02-01 00:00:00
abstract：:We describe the use of electron-capture gas chromatography or reversed-phase "high-performance" liquid chromatography for concurrent analysis for diazepam and nordiazepam in serum. In the gas-chromatographic analysis our use of a new chemically deactivated stationary liquid phase, SP 2250-DB (Supelco, Inc.), resulted ...
journal_title：Clinical chemistry
pub_type： 杂志文章
doi：
更新日期：1979-07-01 00:00:00
abstract：:We evaluated the Kallestad "Quanticoat" cortisol RIA for direct (no extraction) measurement of urinary free cortisol, which requires no solvent extraction. An analytical-recovery study showed a linear regression of y (measured) = 0.65x (added) + 37.5 micrograms/L (Sy.x = 21.4 micrograms/L, r = 0.978, n = 48). Recovery...
journal_title：Clinical chemistry
pub_type： 杂志文章
doi：
更新日期：1989-01-01 00:00:00
abstract：:Serum specimens from patients on primidone therapy were assayed by two currently available procedures: a commercially available enzyme immunoassay (EMIT) and a published gas-chromatographic procedure. Both procedures were done with commercially available materials and equipment. Results by the two procedures agreed we...
journal_title：Clinical chemistry
pub_type： 杂志文章
doi：
更新日期：1976-06-01 00:00:00
abstract：:The potential errors of the one-point calibration technique are described mathematically. I examine the theoretical causes and effects of analytical errors in absorbance and of errors in determining calibration concentration, and discuss techniques for minimizing their impact. The dependence of these errors on the cal...
journal_title：Clinical chemistry
pub_type： 杂志文章
doi：
更新日期：1984-07-01 00:00:00
abstract：:We describe specifications for high-purity 4-nitrophenol, which is suitable for spectrophotometric standardization. Such a reference material is needed in clinical enzymology to establish the proper molar absorptivity of 4-nitrophenol under final reaction conditions, particularly for measuring alkaline phosphatase act...
journal_title：Clinical chemistry
pub_type： 杂志文章
doi：
更新日期：1980-05-01 00:00:00
abstract：BACKGROUND:Aberrant DNA hypermethylation of CpG islands occurs frequently throughout the genome in human colorectal cancer (CRC). A genome-wide DNA hypermethylation analysis technique using circulating cell-free DNA (cfDNA) is attractive for the noninvasive early detection of CRC and discrimination between CRC and othe...
journal_title：Clinical chemistry
pub_type： 杂志文章
doi：10.1373/clinchem.2019.301804
更新日期：2019-07-01 00:00:00
abstract：:In this automated apoenzyme reactivation immunoassay system (Ames Optimate) for thyroxin-binding globulin (TBG), the sample and N6-aminohexylflavin adenine dinucleotide-labeled TBG react sequentially with antiserum. Then apoglucose oxidase is added to combine with the free fraction and generate glucose oxidase activit...
journal_title：Clinical chemistry
pub_type： 杂志文章
doi：
更新日期：1986-05-01 00:00:00
abstract：:The location of the Reference Value for an analyte within the population distribution affects the magnitude of error due to methodological bias. Using the gaussian distribution, we evaluated the effects of systematic and proportional biases of the method (positive and negative), mean value, and standard deviation on t...
journal_title：Clinical chemistry
pub_type： 杂志文章
doi：
更新日期：1988-11-01 00:00:00
abstract：BACKGROUND:Studies of the effects of tobacco smoke often rely on reported exposure to cigarette smoke, a measure that is subject to bias. We describe here the relationship between parental smoking exposure as assessed by urinary cotinine excretion and lung function in children with asthma. METHODS:We studied 90 childr...
journal_title：Clinical chemistry
pub_type： 临床试验,杂志文章
doi：
更新日期：1999-04-01 00:00:00
abstract：BACKGROUND:The liver is frequently subject to insult because of viral infection, alcohol abuse, or toxic chemical exposure. Extensive research has been conducted to identify blood markers that can better discern liver damage, but little progress has been achieved in clinical practice. Recently, circulating microRNAs (m...
journal_title：Clinical chemistry
pub_type： 杂志文章
doi：10.1373/clinchem.2010.147850
更新日期：2010-12-01 00:00:00
abstract：:Endotoxin, the lipopolysaccharide cell wall constituent of Gram-negative bacteria, produces symptoms of the Gram-negative sepsis syndrome. By measuring endotoxin in blood from septic patients it may be possible to select a subpopulation of patients in which mortality can be prevented by treatment with anti-endotoxin a...
journal_title：Clinical chemistry
pub_type： 杂志文章
doi：
更新日期：1994-08-01 00:00:00
abstract：BACKGROUND:In recent years, a large number of studies have been published on the performance of glucose monitors. The quality of these reports is not known. METHODS:We searched the PubMed database for performance evaluations of handheld glucose monitors published from August 2002 to November 2006. Relevant articles we...
journal_title：Clinical chemistry
pub_type： 杂志文章,评审
doi：10.1373/clinchem.2006.083493
更新日期：2007-06-01 00:00:00
