Abstract:
:The analytical performance of laboratories participating in the dialysis fluids and water aluminum program of the Guildford External Quality Assessment Scheme over the period 1986-1993 has been reviewed. For aluminum concentrations > 3.33 mumol/L in dialysis fluids, the between-laboratory CV has fallen from approximately 36% to 23%, whereas for specimens of water the reduction was from 36% to approximately 18%. Improvements at lower concentrations were less impressive. Performance of individual participants varied; only a few consistently provided accurate results. Many of the participants are able to measure serum aluminum well, so lack of expertise is not responsible for poor results. We suggest that matrix effects associated with different specimen types have a significant influence on performance and that due account is not always taken of these factors. Resolution of these problems would be aided by appropriate reference materials.
journal_name
Clin Chemjournal_title
Clinical chemistryauthors
Taylor A,Briggs RJ,Cevik Csubject
Has Abstractpub_date
1994-08-01 00:00:00pages
1517-21issue
8eissn
0009-9147issn
1530-8561journal_volume
40pub_type
杂志文章abstract::Glucose was measured by the ferricyanide, the Beckman glucose oxidase, and the hexokinase procedures in 228 plasma samples taken during standard oral glucose-tolerance tests in 17 normal subjects and in 21 chemical diabetics. The neocuproine method was also used to measure glucose concentration in 156 samples (78 befo...
journal_title:Clinical chemistry
pub_type: 杂志文章
doi:
更新日期:1982-12-01 00:00:00
abstract::We recently proposed a quantitative PCR procedure for the absolute measurement of c-erbB-2 oncogene amplification, based on the simultaneous polymerase chain reaction (PCR) amplification of the target gene and of a competitor DNA molecule acting as internal standard. To increase the number of assayable oncogenes and t...
journal_title:Clinical chemistry
pub_type: 杂志文章
doi:
更新日期:1995-06-01 00:00:00
abstract::For many lysosomal storage disorders, presymptomatic detection, before the onset of irreversible pathology, will greatly improve the efficacy of current and proposed therapies. In the absence of a family history, presymptomatic detection can be achieved only by a comprehensive newborn screening program. Recently we re...
journal_title:Clinical chemistry
pub_type: 杂志文章
doi:
更新日期:1998-10-01 00:00:00
abstract::We report the first solid-phase radioimmunoassay for triiodothyronine with use of antibody-coated tubes, which is designed specifically for the fully automated radioimmunoassay instrument, Micromedic Systems' "Concept 4 Automatic Radioassay." Antisera to triiodothyropropionic acid/bovine serum albumin were raised in r...
journal_title:Clinical chemistry
pub_type: 杂志文章
doi:
更新日期:1977-05-01 00:00:00
abstract::A one-stage semiautomated method for estimating total phospholipids in plasma is reported. The phospholipids are extracted into aqueous ethanol, combined with a Lewis acid, and the change in pH is monitored colorimetrically. The method, compared with the acid digestion method of Gomori [J. Lab. Clin. Med. 27, 955 (194...
journal_title:Clinical chemistry
pub_type: 杂志文章
doi:
更新日期:1977-09-01 00:00:00
abstract::We have developed a sensitive procedure for determination of serum copper by use of the color reagent 4-(3,5-dibromo-2-pyridylazo)-N-ethyl-N-sulfopropylaniline. After mixing serum sample and reagent, and incubating at 37 degrees C for 5 min, we measure the absorbance of the resulting chelate complex at 580 nm (molar a...
journal_title:Clinical chemistry
pub_type: 杂志文章
doi:
更新日期:1989-04-01 00:00:00
abstract::We describe a method used for determining serotonin and tryptamine in urine after oral loading with their precursor amino acid. Several factors affecting prepurification and chromatographic separation of both indoleamines were optimized, including sample extraction and mobile-phase composition. Under optimal condition...
journal_title:Clinical chemistry
pub_type: 杂志文章
doi:
更新日期:1989-01-01 00:00:00
abstract:BACKGROUND:The B-type natriuretic peptides (BNP and N-terminal pro-BNP) are secreted by the heart and, in the case of BNP, serve to maintain circulatory homeostasis through renal and vascular actions and oppose many effects of the renin-angiotensin system. Recent evidence suggests that in patients with severe heart fai...
journal_title:Clinical chemistry
pub_type: 杂志文章
doi:10.1373/clinchem.2013.210435
更新日期:2014-03-01 00:00:00
abstract::Various laboratories have reported endogenous digoxin-like immunoreactive factor(s) (DLIF) in blood from patients in renal failure or liver failure, from newborn infants, and from third-trimester pregnant women. Similar immunoreactivity has been detected in amniotic fluid, in cord blood, and in urine and serum from no...
journal_title:Clinical chemistry
pub_type: 杂志文章,评审
doi:
更新日期:1985-09-01 00:00:00
abstract::We describe the case of a three-year-old girl with Wilms' tumor, whose serum showed at least a fivefold increase in relative viscosity although concentrations of albumin and immunoglobulins were normal. An unusual electrophoretogram of serum protein prompted further investigation. The increased viscosity was caused by...
journal_title:Clinical chemistry
pub_type: 杂志文章
doi:
更新日期:1984-06-01 00:00:00
abstract:BACKGROUND:The optimal situation in external quality assessment (EQA) is to use commutable materials. No previous study has examined the commutability of a whole-blood material for point-of-care (POC) testing. The aim of this study was to determine the commutability of the Norwegian Quality Improvement of Laboratory Ex...
journal_title:Clinical chemistry
pub_type: 杂志文章
doi:10.1373/clinchem.2018.300202
更新日期:2019-06-01 00:00:00
abstract::This enzyme immunoassay procedure for pregnancy-associated plasma protein type A involves a "sandwich"-type system in microtitration plates. One can detect 0.27 mg of the protein per liter of serum, with a between-batch CV of 10.2%, and the antiserum used does not cross react with any of the other placentally derived ...
journal_title:Clinical chemistry
pub_type: 杂志文章
doi:
更新日期:1984-11-01 00:00:00
abstract::Sensitivity, stability, and specificity of the color-producing reaction of hydrogen peroxide with bezidine, leuco-malachite green, or o-dianisidine were tested in numerous systems containing hemoglobin and other hemoproteins. Use of urea or low temperature (to minus 12 degrees C), or both, was highly beneficial, espec...
journal_title:Clinical chemistry
pub_type: 杂志文章
doi:
更新日期:1975-03-01 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:BACKGROUND:We analyzed the low-dose (1 microg) rapid adrenocorticotropic hormone test (LDST) in 17 patients with a normal hypothalamic-pituitary-adrenal axis to determine reference intervals for the LDST on the basis of poststimulation cortisol increments. METHODS:We analyzed test results for 17 patients (14 females a...
journal_title:Clinical chemistry
pub_type: 杂志文章
doi:10.1373/clinchem.2005.061267
更新日期:2006-04-01 00:00:00
abstract::Creatinine and specific gravity (relative density) measurements both allow differences in urine concentration to be taken into account in determining urine cotinine concentrations. In this study we demonstrate that the variance of urine cotinine measurements is reduced comparably when either creatinine or specific gra...
journal_title:Clinical chemistry
pub_type: 杂志文章
doi:
更新日期:1994-04-01 00:00:00
abstract::We describe a gas--liquid-chromatographic method for determining the concentration of amantadine hydrochloride in urine with beta-phenylethylamine as internal standard. The urine sample is made alkaline and extracted with 0.5 mL of chloroform. After centrifugation the aqueous layer is aspirated, and an aliquot of the ...
journal_title:Clinical chemistry
pub_type: 杂志文章
doi:
更新日期:1980-02-01 00:00:00
abstract::We describe a rapid, precise, and sensitive radiometric assay for human lactoferrin. In this typical "sandwich"-type assay, anti-human lactoferrin is adsorbed onto a polystyrene sphere and bound lactoferrin is detected by the subsequent binding of 125I-labeled anti-human lactoferrin. The assay is accurate for lactofer...
journal_title:Clinical chemistry
pub_type: 杂志文章
doi:
更新日期:1985-03-01 00:00:00
abstract::We report the kinetics of the reactions of unconjugated bilirubin and conjugated bilirubin with p-diazobenzene sulfonic acid in aqueous media. Our studies confirm that each reaction proceeds in two steps and that the second step is catalyzed by sulfanilic acid. In the presence of an excess of p-diazobenzenesulfonic ac...
journal_title:Clinical chemistry
pub_type: 杂志文章
doi:
更新日期:1978-10-01 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::We devised a method for assaying serum lactate dehydrogenase isoenzyme 1 (LD-1) activity specifically by preincubation with alpha-chymotrypsin and guanidine. Cleavage of phenylalanine bonds in the loop of A and B subunits of LD-3, LD-4, and LD-5 isoenzymes (residues 117-119) by incubation with alpha-chymotrypsin for a...
journal_title:Clinical chemistry
pub_type: 杂志文章
doi:
更新日期:1992-11-01 00:00:00
abstract::A method has been developed for the determination of inorganic arsenic [As(III) and As(V)] and its organic metabolites (monomethylarsenic and dimethylarsenic) in urine by flow-injection hydride generation atomic absorption spectrometry. The nontoxic seafood-derived arsenobetaine and arsenocholine species were first se...
journal_title:Clinical chemistry
pub_type: 杂志文章
doi:
更新日期:1993-08-01 00:00:00
abstract:BACKGROUND:The goal of this study was to establish a plasma microRNA profile by use of next-generation sequencing that could aid in assessment of patient prognosis in nasopharyngeal carcinoma (NPC). METHODS:Two panels of NPC patients and healthy controls (HCs) were recruited for this study. We used deep sequencing to ...
journal_title:Clinical chemistry
pub_type: 杂志文章
doi:10.1373/clinchem.2013.214213
更新日期:2014-05-01 00:00:00
abstract::Determination of the ratio of testosterone to epitestosterone (T/E) in urine is used to detect testosterone administration in athletes, with a ratio > 6 considered as evidence of an offense. We show that administration of ketoconazole, which inhibits testosterone biosynthesis, may be useful for differentiating between...
journal_title:Clinical chemistry
pub_type: 杂志文章
doi:
更新日期:1993-09-01 00:00:00
abstract:BACKGROUND:The recent interest of clinical laboratories in developing serum testosterone assays based on isotope dilution-liquid chromatography-tandem mass spectrometry (ID-LC-MS/MS) stems from the lack of accuracy of direct immunoassays. In this study, we assessed the accuracy and state of standardization (traceabilit...
journal_title:Clinical chemistry
pub_type: 杂志文章
doi:10.1373/clinchem.2008.105841
更新日期:2008-08-01 00:00:00
abstract::We studied several risk factors in relation to parental cardiovascular heart disease: total cholesterol, triglycerides, high-density lipoprotein (HDL) cholesterol, low-density lipoprotein (LDL) cholesterol, apolipoprotein (apo) A-I, apo B, and lipoprotein(a) [Lp(a)] were determined in 322 serum samples (43 from subjec...
journal_title:Clinical chemistry
pub_type: 杂志文章
doi:
更新日期:1993-03-01 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::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::Establishing associations between environmental agents and disease presents challenges to both epidemiologists and toxicologists, particularly in cases of complex gene-environment interactions and when there is a long latency between exposure and disease. Biologic markers, physiological signals that reflect exposure, ...
journal_title:Clinical chemistry
pub_type: 杂志文章,评审
doi:
更新日期:1994-07-01 00:00:00
abstract::We describe a gas-chromatographic method for measuring chlorpromazine and its metabolites chlorpromazine sulfoxide, mono-N-desmethylchlorpromazine, and di-N-desmethylchlorpromazine at therapeutic concentrations in human serum, with use of a nitrogen detector. The compounds are extracted from serum at pH 10.5 into hexa...
journal_title:Clinical chemistry
pub_type: 杂志文章
doi:
更新日期:1979-07-01 00:00:00