Abstract:
:The calculation of within-laboratory imprecision in quality-assessment (QA) programmes normally involves combining data from different analyte concentrations to calculate an average standard deviation (SD) or coefficient of variation. However, for immunoassay neither of these parameters is concentration independent. This paper describes a method of calculating within-laboratory imprecision in QA programmes by assuming a linear relationship between SD and analyte concentration. This method is used in programmes conducted by the Australian Joint Working Party for Quality Control in Immunoassay to calculate imprecision at the limits of the reference range. Results from these programmes show that this method better represents the differences in imprecision between analytes, methods and laboratories than the calculation of a single imprecision parameter. The method is trivial for a computer and its robustness has been validated by Monte Carlo simulation. It is suggested that major differences in laboratory performance between different QA programmes may be due to inappropriate calculation of single imprecision parameters.
journal_name
Ann Clin Biochemjournal_title
Annals of clinical biochemistryauthors
Compton P,Cole B,Stuart M,Egan Gdoi
10.1177/000456328402100611subject
Has Abstractpub_date
1984-11-01 00:00:00pages
498-503eissn
0004-5632issn
1758-1001journal_volume
21 ( Pt 6)pub_type
杂志文章abstract::A study of conditions for the elution of apo A1 and B lipoproteins from dried blood spots has led to the development of an apo B/A1 ratio assay with results for dried blood spots which are comparable with serum assays. This assay has been developed to be suitable for large scale population screening. The concept of me...
journal_title:Annals of clinical biochemistry
pub_type: 杂志文章
doi:10.1177/000456329303000511
更新日期:1993-09-01 00:00:00
abstract::A comparative evaluation of Beckman (A), Boehringer (B), and Calbiochem (C) kits for the enzymatic end-point determination of urea has been carried out. Acceptable within-day and day-to-day precision was obtained with all kits. The recoveries obtained fulfilled the criteria of Logan (CRC Critical Reviews in Clinical L...
journal_title:Annals of clinical biochemistry
pub_type: 杂志文章
doi:10.1177/000456327801500163
更新日期:1978-09-01 00:00:00
abstract::The effect of acetate and bicarbonate haemodialysis (HD) on the concentrations of erythrocyte, whole-blood and plasma total carnitine (TC), free carnitine (FC), short- (SC) and long-chain acylcarnitine (LC) and acylcarnitine (AC) as well as the ratio of AC to FC was investigated in 30 healthy subjects (15 men and 15 w...
journal_title:Annals of clinical biochemistry
pub_type: 杂志文章
doi:10.1177/000456329903600106
更新日期:1999-01-01 00:00:00
abstract:BACKGROUND:In humans, leptin circulates in a free form and is also bound to macromolecules. The aim of the present study was to compare a rapid acid-ethanol precipitation (AEP) method of measuring bound leptin with the more laborious gel exclusion chromatography (GEC) reference procedure. Serum samples collected from h...
journal_title:Annals of clinical biochemistry
pub_type: 杂志文章
doi:10.1258/000456303763046157
更新日期:2003-03-01 00:00:00
abstract::The osmolality of plasma and heparinised whole blood samples collected from hospital patients was estimated using measurement of the depression of freezing point. There was no clinically significant difference between osmolality measurement made on either whole blood, or plasma taken from the same patient. Neither cel...
journal_title:Annals of clinical biochemistry
pub_type: 杂志文章
doi:10.1177/000456328602300115
更新日期:1986-01-01 00:00:00
abstract:BACKGROUND:It is important to explain target proteins for the understanding of the pathogenesis of vitreoretinal diseases. In a previous study, we identified more than 100 proteins including seven angiogenic-modulated factors in vitreous humours (VHs). Although there have been many reports of expressed protein profiles...
journal_title:Annals of clinical biochemistry
pub_type: 杂志文章
doi:10.1258/acb.2007.007151
更新日期:2008-05-01 00:00:00
abstract:BACKGROUND:Glycated haemoglobin (HbA1c) concentration is lower relative to glyacemic control in diabetic patients on haemodialysis. However, it is unknown as to whether this is also true for diabetic patients with end-stage renal disease but not on haemodialysis. METHODS:Correlations between HbA1c or glycated albumin ...
journal_title:Annals of clinical biochemistry
pub_type: 杂志文章
doi:10.1258/acb.2011.011161
更新日期:2012-01-01 00:00:00
abstract:BACKGROUND:Neutrophilic polymorphonuclear leukocytes play a crucial role in the host defence against bacterial and fungal infections. They participate in the inflammatory response through the liberation of peptides and enzymes like myeloperoxidase (MPO). Therefore, MPO has a potential as a marker enzyme for the diagnos...
journal_title:Annals of clinical biochemistry
pub_type: 杂志文章
doi:10.1258/acb.2011.010249
更新日期:2013-05-01 00:00:00
abstract:BACKGROUND:In the enzyme reaction for the determination of the unbound (free) bilirubin concentration by glucose oxidase and peroxidase, materials with low affinity for serum protein are reactive. The influence of these materials on the determination of serum unbound bilirubin was investigated. METHODS Serum samples fr...
journal_title:Annals of clinical biochemistry
pub_type: 杂志文章
doi:10.1177/000456320203900606
更新日期:2002-11-01 00:00:00
abstract::Background Faecal occult blood testing is an important diagnostic tool for the detection of colorectal cancer. However, it has not been standardized due to the absence of suitable specimens for surveillance. Methods We developed a ready-to-use artificial stool made from rice flour. This new artificial stool homogeneou...
journal_title:Annals of clinical biochemistry
pub_type: 杂志文章
doi:10.1177/0004563217732587
更新日期:2018-05-01 00:00:00
abstract:BACKGROUND:It is now established that the bioactive lipid lysophosphatidic acid (LPA) contributes to cancer initiation, progression and metastasis, including those of prostate cancer. LPA is produced in the serum and plasma mainly by conversion from lysophospholipids through the action of lysophospholipase D (lysoPLD),...
journal_title:Annals of clinical biochemistry
pub_type: 杂志文章
doi:10.1258/000456307782268147
更新日期:2007-11-01 00:00:00
abstract:BACKGROUND:Apolipoprotein concentrations in reflex tears from healthy and noninsulin-dependent diabetes mellitus (NIDDM) subjects were measured and correlated with the stage of diabetic retinopathy. METHODS AND RESULTS:The apolipoprotein A-I (apo A-I) concentrations in the tears from NIDDM patients with retinopathy we...
journal_title:Annals of clinical biochemistry
pub_type: 杂志文章
doi:10.1258/0004563021901748
更新日期:2002-01-01 00:00:00
abstract::Plasma C1 inhibitor (C1-INH) was determined in 64 patients with different malignant diseases and in 58 healthy persons. C1-INH antigen concentration was measured by radial immunodiffusion (RID), whereas its functional activity was assayed with chromogenic substrate. Within-run and day-to-day precision of both methods ...
journal_title:Annals of clinical biochemistry
pub_type: 杂志文章
doi:10.1177/000456329102800609
更新日期:1991-11-01 00:00:00
abstract::The presence of antibodies in some patients' serum has long been known to be a potential source of interference in immunoassays, as shown by numerous case reports. These often appear after the introduction of a new analyte (e.g. troponin) and then decrease in number as the topic becomes exhausted. This highlights the ...
journal_title:Annals of clinical biochemistry
pub_type: 杂志文章,评审
doi:10.1258/000456302760042128
更新日期:2002-07-01 00:00:00
abstract::Acid-urea extract of rat brain was examined by glucagon-like peptide-1 (GLP-1) specific radioimmunoassay. A single peak was observed which co-eluted with GLP-1(7-36)amide on gel filtration and anion exchange chromatography. In contrast, GLP-1(1-37) was not detected under our experimental conditions. The fact that GLP-...
journal_title:Annals of clinical biochemistry
pub_type: 杂志文章
doi:10.1177/000456328902600214
更新日期:1989-03-01 00:00:00
abstract::Quadriceps muscle specimens from autopsy of 28 neonates (gestational age 25-42 weeks) were investigated to determine pyruvate and malate oxidation rates and several enzymes of the mitochondrial oxidative process. In general, the levels of all mitochondrial parameters measured, including carnitine levels, were lower in...
journal_title:Annals of clinical biochemistry
pub_type: 杂志文章
doi:10.1177/000456329202900604
更新日期:1992-11-01 00:00:00
abstract::Erythrocuprein (superoxide dismutase) has recently been shown to have an enzymic function towards superoxide anions. The discovery of superoxide dismutase, its mode of action, and estimation are reviewed along with a brief introduction to oxygen activation and free-radical chemistry. The formation, activity, and destr...
journal_title:Annals of clinical biochemistry
pub_type: 杂志文章
doi:10.1177/000456327601300125
更新日期:1976-05-01 00:00:00
abstract:BACKGROUND:Combined lipid and glucose point-of-care testing (POCT) devices could facilitate widespread population screening for cardiovascular disease (CVD) and diabetes as part of the NHS Vascular Risk Assessment and Management Program (NHS Health Checks). An evaluation of the Cholestech LDX and CardioChek PA POCT ana...
journal_title:Annals of clinical biochemistry
pub_type: 杂志文章
doi:10.1177/0004563213482890
更新日期:2014-01-01 00:00:00
abstract::During incubation with rabbit blood in vitro rabbit-muscle lactate dehydrogenase-5 was inactivated at a rate similar to that observed in vivo. By contrast plasma and plasma containing erythrocytes had no effect on the enzyme activity, but plasma containing leucocytes inactivated the enzyme at the same rate as whole bl...
journal_title:Annals of clinical biochemistry
pub_type: 杂志文章
doi:10.1177/000456327701400109
更新日期:1977-01-01 00:00:00
abstract::Adequate control of performance in immunoassays of maternal serum alpha-fetoprotein is an essential part of screening for neural tube defects. Information derived from external quality assessment schemes may be of limited value in monitoring individual laboratory performance and stresses the need for proper internal q...
journal_title:Annals of clinical biochemistry
pub_type: 杂志文章
doi:10.1177/000456328001700611
更新日期:1980-11-01 00:00:00
abstract::Whole blood and washed erythrocytes from nutritionally normal and abnormal elderly patients were stored at room temperature, 4 degrees C and -20 degrees C for up to 14 days. In both groups, and under all storage conditions, the erythrocyte transketolase (ETK) activity and the thiamine pyrophosphate (TPP) effect decrea...
journal_title:Annals of clinical biochemistry
pub_type: 杂志文章
doi:10.1177/000456328502200417
更新日期:1985-07-01 00:00:00
abstract::A high-pressure liquid chromatography procedure for the measurement of free catecholamines in urine is described. 'On-line' sample preparation using a cartesian robot combined with the ASTED process ensures minimal operator intervention and reduced costs. ...
journal_title:Annals of clinical biochemistry
pub_type: 杂志文章
doi:10.1177/000456328902600412
更新日期:1989-07-01 00:00:00
abstract::Background Measurement of serum dexamethasone during the overnight dexamethasone-suppression test has been recommended to reduce false-positive results when investigating Cushing's syndrome or increasingly commonly found adrenal incidentalomas. Despite this, there remains a paucity of well-validated dexamethasone meth...
journal_title:Annals of clinical biochemistry
pub_type: 杂志文章
doi:10.1177/0004563218766566
更新日期:2018-11-01 00:00:00
abstract:BACKGROUND:Pharmacometabonomics is a new branch of science, first described in 2006 and defined as 'the prediction of the effects of a drug on the basis of a mathematical model of pre-dose metabolite profiles'. Pharmacometabonomics has been used to predict drug metabolism, pharmacokinetics (PK), drug safety and drug ef...
journal_title:Annals of clinical biochemistry
pub_type: 杂志文章,评审
doi:10.1177/0004563213497929
更新日期:2013-11-01 00:00:00
abstract::The seasonal variation of serum 25-hydroxy vitamin D3 and 1,25-dihydroxy-vitamin D has been investigated. Blood was taken from 27 healthy volunteers, aged 21-44 years old at 3 monthly intervals over a period of 1 year. A scrolling monthly programme with 12 quarterly (3 month) time periods was developed. A summer assoc...
journal_title:Annals of clinical biochemistry
pub_type: 杂志文章
doi:10.1177/000456329403100105
更新日期:1994-01-01 00:00:00
abstract:BACKGROUND AND METHODS:We report a case of insulinoma in which the diagnosis was very challenging as some of the biochemical data were consistently equivocal. In order to assess the relative reliability of the analytical tests, retrospective biochemical data on 45 other cases of histologically confirmed insulinoma were...
journal_title:Annals of clinical biochemistry
pub_type: 杂志文章
doi:10.1258/000456303770367315
更新日期:2003-11-01 00:00:00
abstract:BACKGROUND:We found a unique cholesteryl ester transfer protein (CETP) deficient case with markedly elevated serum triglyceride (TG) as well as high-density lipoprotein cholesterol (HDL-C) levels. Most of the CETP deficiency cases were reported to have normal or reduced serum TG with elevated HDL-C. METHODS:The case s...
journal_title:Annals of clinical biochemistry
pub_type: 杂志文章
doi:10.1258/acb.2009.008249
更新日期:2009-11-01 00:00:00
abstract::Some inherited metabolic disorders (IMDs) can cause significant complications during pregnancy, affecting the mother and/or the fetus. Although it appears that only a minority of IMDs have these effects, experience is still being acquired. For some disorders, patients will not have reached child-bearing age. Pregnanci...
journal_title:Annals of clinical biochemistry
pub_type: 杂志文章,评审
doi:10.1258/000456302320314458
更新日期:2002-09-01 00:00:00
abstract:BACKGROUND:Individuals who are unable to metabolize the short-acting muscle relaxant succinylcholine due to abnormal cholinesterase activity are currently investigated via spectrophotometry using artificial substrates and enzyme inhibitors. Methods have been described using succinylcholine as substrate but with measure...
journal_title:Annals of clinical biochemistry
pub_type: 杂志文章
doi:10.1258/acb.2010.009169
更新日期:2010-05-01 00:00:00
abstract::Using a high-performance liquid chromatography method, we measured seven commonly prescribed benzodiazepines (chlordiazepoxide, nitrazepam, nordiazepam, oxazepam, lorazepam, temazepam and diazepam) in 100 urine samples obtained from patients attending the Leeds Addiction Unit. All of the urines selected for investigat...
journal_title:Annals of clinical biochemistry
pub_type: 杂志文章
doi:10.1177/000456329703400110
更新日期:1997-01-01 00:00:00