Abstract:
:We have developed and evaluated a new procedure for detecting trends in quality-control measurements and applied it to laboratory data. The method requires the use of sequential or "moving" slope estimates to identify trends. Formulae are derived to estimate the regression error for the moving slope directly from the standard deviation of the analytical measurements obtained during characterization runs. Control limits for the moving slope depend only on this regression error, the span of the slope, and the desired statistical level of control. The moving slope can be plotted with control limits to determine out-of-control points. The statistical power of the moving slope is found to be much greater than that of an often-used test for trends. An example of the use of the moving slope is shown for quality-control measurements for total cholesterol obtained over several years. We conclude that the moving slope procedure has considerably more statistical power than trend rules and that it yields more useful information to the analyst.
journal_name
Clin Chemjournal_title
Clinical chemistryauthors
Smith SJ,Myers GLsubject
Has Abstractpub_date
1991-03-01 00:00:00pages
341-6issue
3eissn
0009-9147issn
1530-8561journal_volume
37pub_type
杂志文章abstract::A profile (chromatographic pattern) of the neutral and acidic metabolites present in cerebrospinal fluid from newborns and infants was obtained by gas-liquid chromatography. The metabolites are those extracted with ethyl acetate and diethyl ether. They are converted to trimethylsilyl ether derivatives, and chromatogra...
journal_title:Clinical chemistry
pub_type: 杂志文章
doi:
更新日期:1976-05-01 00:00:00
abstract::It is time-consuming to process and compare the clinical and marker information registered during monitoring of breast cancer patients. To facilitate the assessment, we developed a computer program for interpreting consecutive measurements. The intraindividual biological variation, the analytical precision profile, th...
journal_title:Clinical chemistry
pub_type: 临床试验,杂志文章,随机对照试验
doi:
更新日期:2000-08-01 00:00:00
abstract::Gene mutations responsible for the majority of Duchenne/Becker muscular dystrophy (DMD/BMD) and cystic fibrosis (CF) chromosomes have been identified. We describe a DNA-based strategy, rather than the traditional biochemical assays, for screening newborns. DNA sequences spanning the CF mutation and several DMD/BMD del...
journal_title:Clinical chemistry
pub_type: 杂志文章
doi:
更新日期:1990-10-01 00:00:00
abstract::We compared the activities of thyroid-stimulating antibodies (TSAb) measured in cultures of human thyrocytes and the values for thyrotropin-receptor antibodies (TRAb) as measured with a commercial kit based on use of radiolabeled receptors. Sera were obtained from patients with Graves' disease before, during, and afte...
journal_title:Clinical chemistry
pub_type: 杂志文章
doi:
更新日期:1986-07-01 00:00:00
abstract:BACKGROUND:In 2008, the US Food and Drug Administration (FDA) issued a Guidance for Industry statement formally recognizing (during drug development) the conjoined nature of type 2 diabetes (T2D) and cardiovascular disease (CVD), which has precipitated an urgent need for panels of markers (and means of analysis) that a...
journal_title:Clinical chemistry
pub_type: 杂志文章
doi:10.1373/clinchem.2010.156976
更新日期:2011-05-01 00:00:00
abstract::Using automated measurements of kappa and lambda light chains and IgG, IgA, and IgM, we assessed the utility of the kappa/lambda ratio and the heavy chain/light chain ratio in characterizing monoclonal immunoglobulins previously identified by sensitive electrophoresis on agarose gel and typed by immunofixation or immu...
journal_title:Clinical chemistry
pub_type: 杂志文章
doi:
更新日期:1987-10-01 00:00:00
abstract:BACKGROUND:The Dutch project "Calibration 2000" aims at harmonization of laboratory results via calibration by development of matrix-based secondary reference materials. We considered the selection, preparation, and characterization of 34 potential reference materials (PRMs). METHODS:Sixteen PRMs were prepared either ...
journal_title:Clinical chemistry
pub_type: 杂志文章,多中心研究
doi:
更新日期:2002-09-01 00:00:00
abstract:BACKGROUND:Atherosclerosis is a systemic disease with focal rupture of vulnerable plaque responsible for major clinical events. Several population-based studies indicate an association between lipoprotein-associated phospholipase A2 (Lp-PLA2) and cardiovascular events. Lp-PLA2 is emerging as a biomarker that may be a p...
journal_title:Clinical chemistry
pub_type: 杂志文章,评审
doi:10.1373/clinchem.2006.070672
更新日期:2006-09-01 00:00:00
abstract:BACKGROUND:Remnant lipoprotein-cholesterol (RLP-C) concentrations in sera of healthy individuals are very low (0.080-0.437 mmol/L), making conventional cholesterol methods poorly suited to this purpose. We have developed a highly sensitive cholesterol assay (CD method) and applied it to the RLP-C assay. METHODS:The CD...
journal_title:Clinical chemistry
pub_type: 杂志文章
doi:
更新日期:2002-05-01 00:00:00
abstract::We describe an enzyme-linked immunosorbent assay (ELISA) for urinary albumin. It requires only commercially available reagents, can detect as little as 16 micrograms of albumin per liter, and analytical recovery ranges from 92 to 116%. The assay is simple, rapid, and inexpensive. Albumin excretion was 6.2 (SD 4.1) mg/...
journal_title:Clinical chemistry
pub_type: 杂志文章
doi:
更新日期:1987-04-01 00:00:00
abstract::We investigated the effects on plasma osteocalcin concentrations of different anticoagulants used to collect the blood samples. Plasma osteocalcin concentrations measured by enzyme immunoassay and radioimmunoassay are influenced by the nature of the anticoagulants used. The most significant difference between concentr...
journal_title:Clinical chemistry
pub_type: 杂志文章
doi:
更新日期:1991-02-01 00:00:00
abstract::We describe a novel assay for measuring glycohemoglobin directly from anticoagulated whole blood with the Abbott IMx analyzer. The glycohemoglobin is labeled with a soluble polyanionic affinity reagent and the anionic complex is then captured with a cationic solid-phase matrix. Glycohemoglobin is quantified by measuri...
journal_title:Clinical chemistry
pub_type: 杂志文章
doi:
更新日期:1993-10-01 00:00:00
abstract:BACKGROUND:Altered germline expression of genes may represent a powerful marker of genetic or epigenetic predisposition to cancer or other diseases. METHODS:We developed and validated a method of nonfluorescent primer extension that uses a single dideoxynucleotide and denaturing HPLC (DHPLC) to analyze the relative al...
journal_title:Clinical chemistry
pub_type: 杂志文章
doi:10.1373/clinchem.2009.126300
更新日期:2009-09-01 00:00:00
abstract::Lactate dehydrogenase (LD) isoenzymes 1 and 2 in human serum were separated on a column of diethylaminoethyl-Sephadex. Samples layered on mini-columns were eluted with buffered sodium chloride (100, 150, and 200 mmol/liter). Lactate dehydrogenase activity in column effluents was measured by the Wacker method, and thei...
journal_title:Clinical chemistry
pub_type: 杂志文章
doi:
更新日期:1978-03-01 00:00:00
abstract:BACKGROUND:To address the continuing need for the standardization of clinical human cardiac troponin I (cTnI) assays, NIST, with the assistance of the AACC/IFCC Cardiac Troponin I Standardization Committee, has developed a new certified reference material, Standard Reference Material (SRM) 2921: Human Cardiac Troponin ...
journal_title:Clinical chemistry
pub_type: 杂志文章
doi:10.1373/clinchem.2005.051359
更新日期:2006-02-01 00:00:00
abstract:BACKGROUND:Epidemiologists have observed that blood donation is associated with decreased risk of type 2 diabetes and cardiovascular disease. METHODS:We investigated the relationship between iron stores and insulin sensitivity, after controlling for known confounding factors, and compared insulin sensitivity between b...
journal_title:Clinical chemistry
pub_type: 杂志文章
doi:10.1373/clinchem.2004.046847
更新日期:2005-07-01 00:00:00
abstract::Backpropagation neural networks are a computer-based pattern-recognition method that has been applied to the interpretation of clinical data. Unlike rule-based pattern recognition, backpropagation networks learn by being repetitively trained with examples of the patterns to be differentiated. We describe and analyze t...
journal_title:Clinical chemistry
pub_type: 临床试验,杂志文章,随机对照试验
doi:
更新日期:1993-09-01 00:00:00
abstract:BACKGROUND:The 2447 A > T pathogenic variation at codon 816 of exon 17 (D816V) in the KIT gene, occurring in systemic mastocytosis (SM), leads to constitutive activation of tyrosine kinase activity and confers resistance to the tyrosine kinase inhibitor imatinib mesylate. Thus detection of this variation in SM patients...
journal_title:Clinical chemistry
pub_type: 杂志文章
doi:10.1373/clinchem.2006.068205
更新日期:2006-12-01 00:00:00
abstract:BACKGROUND:The European Atherosclerosis Society-European Federation of Clinical Chemistry and Laboratory Medicine Consensus Panel aims to provide recommendations to optimize atherogenic lipoprotein quantification for cardiovascular risk management. CONTENT:We critically examined LDL cholesterol, non-HDL cholesterol, a...
journal_title:Clinical chemistry
pub_type: 杂志文章
doi:10.1373/clinchem.2018.287037
更新日期:2018-07-01 00:00:00
abstract::A literature review of the effects of long-term freezer storage on concentrations of antioxidant micronutrients in serum or plasma showed that a high proportion of the studies that compared the concentrations of retinol, beta-carotene, or alpha-tocopherol in fresh and stored serum were deficient because of small numbe...
journal_title:Clinical chemistry
pub_type: 杂志文章
doi:
更新日期:1993-06-01 00:00:00
abstract::Radioimmunoassay of triiodothyronine was performed with a homogeneous incubation system. Bound and free ligand were separated by partitioning in an aqueous two-phase system. The agreement between the results obtained with this technique and conventional heterogeneous radioimmunoassay was very good (r = 0.981). ...
journal_title:Clinical chemistry
pub_type: 杂志文章
doi:
更新日期:1982-04-01 00:00:00
abstract:BACKGROUND:Variability among assays used to measure intact parathyroid hormone (iPTH) is of particular concern because of the routine use of iPTH assay results to guide management of osteodystrophy and calcium metabolism in patients with end-stage renal disease (ESRD). The aim of this study was to determine the extent ...
journal_title:Clinical chemistry
pub_type: 杂志文章
doi:10.1373/clinchem.2006.071589
更新日期:2006-09-01 00:00:00
abstract:BACKGROUND:Measurement of purine and pyrimidine metabolites presents complex problems for separations currently performed by HPLC and thin-layer chromatography in clinical practice. We developed a novel capillary electrophoresis method for this purpose. METHODS:Separations were performed in 60 mmol/L borate-2-amino-2-...
journal_title:Clinical chemistry
pub_type: 杂志文章
doi:
更新日期:1999-12-01 00:00:00
abstract:BACKGROUND:Since its beginnings, newborn screening for cystic fibrosis (CF) using an assay for immunoreactive trypsinogen (IRT) has been plagued by a high rate of false-positive results (screen positive, diagnosis negative), despite attempts to reduce this rate by use of altered cutoffs and second-tier DNA testing. IRT...
journal_title:Clinical chemistry
pub_type: 杂志文章
doi:10.1373/clinchem.2009.132480
更新日期:2010-03-01 00:00:00
abstract::Peroxidation of lipids is believed to play a key role in various degenerative diseases. However, few simple tests are able to detect individual susceptibility or resistance to peroxidation. Measurement of the basal concentrations of lipid peroxides in plasma is not satisfactory because they are so low. Therefore, we d...
journal_title:Clinical chemistry
pub_type: 杂志文章
doi:
更新日期:1991-10-01 00:00:00
abstract::We developed an enzyme-linked immunosorbent assay (ELISA) system for antibodies to the hepatitis C virus (HCV), using two new recombinant antigens (c11 and c7) derived from the HCV genome. The performance of this ELISA system (Imucheck HCV Ab) was examined. The CV values for both intra-assay precision and reproducibil...
journal_title:Clinical chemistry
pub_type: 杂志文章
doi:
更新日期:1992-12-01 00:00:00
abstract::We describe a mass-fragmentographic method for determination in urine of the following metabolites of L-3,4-dihydroxyphenylalanine and dopamine: vanillactic acid, 3,4-dihydroxyphenylacetic acid, 3-methoxy-4-hydroxyphenylethanol, and 3,4-dihydroxyphenylethanol. Deuterated analogs were used as internal standards. The me...
journal_title:Clinical chemistry
pub_type: 杂志文章
doi:
更新日期:1978-01-01 00:00:00
abstract::Owing to increased enzymatic hydrolysis of glutamine, additional ammonia is formed in blood and plasma specimens with increased gamma-glutamyltransferase activity (gamma-GT, EC 2.3.2.2.). The close correlation between gamma-GT and glutaminase (EC 3.5.1.2) activities (r = 0.97) in plasma, the inhibition with 6-diazo-5-...
journal_title:Clinical chemistry
pub_type: 杂志文章
doi:
更新日期:1990-08-01 00:00:00
abstract:BACKGROUND:Hemoglobin-based oxygen carriers (HBOCs) are being developed as potential substitutes for the oxygen-carrying functions of erythrocytes, but athletes may obtain and experiment with HBOCs as an illicit means of enhancing oxygen transport. An electrophoretic technique has been developed to screen for the prese...
journal_title:Clinical chemistry
pub_type: 杂志文章
doi:10.1373/clinchem.2003.026591
更新日期:2004-04-01 00:00:00
abstract:BACKGROUND:Prostate-specific antigen (PSA) is an important marker for the diagnosis and management of prostate cancer, and the free PSA/total PSA ratio has been shown to be efficient for distinguishing prostate cancer from benign prostatic hyperplasia. We report here the characterization of seven mouse monoclonal antib...
journal_title:Clinical chemistry
pub_type: 杂志文章
doi:
更新日期:1999-05-01 00:00:00