Abstract：
BACKGROUND:The American Diabetes Association task force on standardization of insulin assays in 1996 showed wide variation in assay bias. Newer assays are specific for insulin, with several now available on automated immunoassay analyzers. METHODS:In 2004, we compared 11 commercially available insulin assays by analyzing 150 serum samples (99 fasting/51 postprandial) from study participants with various degrees of glucose intolerance (exclusions being type 1 diabetes, insulin treatment, or presence of insulin antibodies). All assays were calibrated against International Reference Preparation 66/304. One assay was not specific for insulin and another was an RIA; 10 assays used enzyme/chemiluminescent labels. Bland-Altman difference plots were modified to use the mean insulin from all assays on the x-axis as a common comparator. RESULTS:As in the 1996 study, insulin values from the different assays varied by a factor of 2, with the nonspecific assay ranking in the middle of the distribution. Spearman rank correlation coefficients, for ranking samples vs the mean, were 0.983-0.997. Both offsets and concentration-dependent differences were seen in the modified difference plots. Imprecision (mean CV) for automated assays (3%) was not significantly different from manual assays (5%). Similar values were obtained when one automated assay was run in laboratories in both the UK and the US. Results of 1 assay showed lower insulin concentrations in heparinized plasma than in serum. CONCLUSIONS:Assay performance must be considered before comparing insulin results. The 2-fold variation in insulin results may be related to specificity, manufacturers' calibration procedures or conversion factors.
journal_name
Clin Chemjournal_title
Clinical chemistryauthors
Manley SE,Stratton IM,Clark PM,Luzio SDdoi
10.1373/clinchem.2006.077784subject
Has Abstractpub_date
2007-05-01 00:00:00pages
922-32issue
5eissn
0009-9147issn
1530-8561pii
clinchem.2006.077784journal_volume
53pub_type
杂志文章,多中心研究abstract：BACKGROUND:Multiple genes that are associated with the risk of developing diabetes or the risk of diabetes complications have been identified by candidate gene analysis and genomewide scanning. These molecular markers, together with clinical data and findings from proteomics, metabolomics, pharmacogenetics, and other m...
journal_title：Clinical chemistry
pub_type： 杂志文章,评审
doi：10.1373/clinchem.2010.156901
更新日期：2011-02-01 00:00:00
abstract：BACKGROUND:The hepatocyte-derived acute-phase reactant C-reactive protein (CRP) has been the subject of intense research over the last 2 decades for its possible role in the pathogenesis of cardiovascular diseases. This research has spawned interest in the use of the blood concentration of CRP for predicting a first co...
journal_title：Clinical chemistry
pub_type： 杂志文章,评审
doi：10.1373/clinchem.2008.115923
更新日期：2009-02-01 00:00:00
abstract：:Ethchlorvynol is a commonly abused sedative hypnotic. I report here a seven-day study of serum ethchlorvynol concentrations in a patient who had received an extreme overdose. These concentrations were correlated with the patient's response to stimuli. Serum ethchlorvynol concentrations were logarithmically related to ...
journal_title：Clinical chemistry
pub_type： 杂志文章
doi：
更新日期：1975-06-01 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-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
abstract：BACKGROUND:An association has been described between mortality in children with meningococcal disease and functional polymorphisms in the interleukin-1 (IL1) cluster. We undertook a multicenter study to evaluate associations of these polymorphisms in a Central European population. PATIENTS AND METHODS:The study involv...
journal_title：Clinical chemistry
pub_type： 杂志文章,多中心研究
doi：10.1373/clinchem.2005.058537
更新日期：2006-03-01 00:00:00
abstract：BACKGROUND:Diabetes mellitus has been historically divided into type 1 and type 2 diabetes, with type 1 being an autoimmune disease and type 2 being primarily a metabolic disease. CONTENT:The current diabetes classification scheme needs to be reevaluated because of the accumulating evidence of immune system involvemen...
journal_title：Clinical chemistry
pub_type： 杂志文章,评审
doi：10.1373/clinchem.2010.148270
更新日期：2011-02-01 00:00:00
abstract：:A patient who ingested a methanol/nitromethane mixture (model airplane fuel) showed an apparent plasma creatinine concentration of 8.0 mmol/L by the Jaffé reaction when the actual creatinine concentration, as measured by a specific enzymatic method, was 0.09 mmol/L. This effect was due to nitromethane in the plasma. I...
journal_title：Clinical chemistry
pub_type： 杂志文章
doi：
更新日期：1989-08-01 00:00:00
abstract：:As the clinical utility of glycated hemoglobin (gHb) measurement increases, so does the need for standardization of values between different methods and different laboratories. Using three different methods, we examined the feasibility of interlaboratory standardization of gHb measurement. A liquid-chromatographic (HP...
journal_title：Clinical chemistry
pub_type： 杂志文章
doi：
更新日期：1986-02-01 00:00:00
abstract：BACKGROUND:PCR-based mutation detection is prone to methodological errors, e.g., in restriction length fragment polymorphism (RFLP) and allele-specific amplification (ASA), false PCR results may occur because of technical faults or atypical new mutations. METHODS:We investigated the ability of a genotyping assay based...
journal_title：Clinical chemistry
pub_type： 杂志文章
doi：
更新日期：1999-12-01 00:00:00
abstract：:We describe modifications to two cartridges, those for alkaline phosphatase and creatinine, on an 18-channel SMAC (Sequential Multichannel Analyzer Computerized), which allow all 18 tests to be run with a commonly prediluted sample. This decreases the required sample size and eliminates the problem of fibrin clots in ...
journal_title：Clinical chemistry
pub_type： 杂志文章
doi：
更新日期：1980-05-01 00:00:00
abstract：:We divided patients with brain lesions into three groups: (a) patients with primary or metastatic brain cancer, (b) brain infarctions, and (c) brain contusion(s). We analyzed each patient's sera for creatine kinase isoenzyme BB (CK-BB), using a monoclonal antibody kit (Impres-BB; International Immunoassay Laboratories...
journal_title：Clinical chemistry
pub_type： 杂志文章
doi：
更新日期：1989-04-01 00:00:00
abstract：BACKGROUND:Prediction of cyclosporine (CSA) efficacy and toxicity in individual patients is difficult. There is no practical, biologically relevant, pharmacodynamic measure of CSA effect. A major effect of CSA is to decrease interleukin-2 (IL-2) production; however, measurement of this effect in isolated lymphocytes as...
journal_title：Clinical chemistry
pub_type： 杂志文章
doi：
更新日期：1999-09-01 00:00:00
abstract：BACKGROUND:Until recently, clinical laboratories have monitored hemophilia treatment by measuring coagulation factors before/after infusion of human-derived or recombinant factors. Substantial changes are expected in the near future based on new therapeutic approaches that have been or are being developed. CONTENT:Hem...
journal_title：Clinical chemistry
pub_type： 杂志文章,评审
doi：10.1373/clinchem.2017.284356
更新日期：2019-02-01 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：:In this simple, quick procedure for determining copper in human serum and urine, the serum and urine specimens were analyzed directly after dilution with a solution of HNO3 and Triton X-100, 1 mL/L each. We calibrated with aqueous standards for quantitation in Zeeman background atomic absorption spectrometry. By modif...
journal_title：Clinical chemistry
pub_type： 杂志文章
doi：
更新日期：1993-09-01 00:00:00
abstract：BACKGROUND:Standardization of hemoglobin (Hb)A(1c) measurements is a process of considerable interest for quality assurance in diabetes management. To contribute to continuous quality improvement and fulfillment of the requirements for reference measurement procedures according to the standards of the International Org...
journal_title：Clinical chemistry
pub_type： 杂志文章
doi：10.1373/clinchem.2009.139477
更新日期：2010-05-01 00:00:00
abstract：:We compared results obtained with the Beckman Creatinine Analyzer (Beckman Instruments, Inc.) to those with the GEMSAEC Centrifugal Analyzer (Electro-Nucleonics, Inc.) and with a manual method for determination of creatinine in serum and urine. Linearity, stability, recovery, and precision were evaluated. Interference...
journal_title：Clinical chemistry
pub_type： 杂志文章
doi：
更新日期：1979-06-01 00:00:00
abstract：:Assays with different specificity are used for cyclosporin monitoring in clinical transplantation. A recent survey of 35 centers showed that 86% used immunoassays for cyclosporin A (CsA). In consensus documents the following performance criteria were recommended: (a) imprecision < or = 10% at 50 microg/L and < or = 5%...
journal_title：Clinical chemistry
pub_type： 杂志文章
doi：
更新日期：1998-10-01 00:00:00
abstract：:Consecutive values for serum osmolality measured in a patient exceeded (548 mOsm) the previously reported pathological range and, indeed, exceeded that generally considered compatible with life. The patient was receiving large amounts of intravenous dimethyl sulfoxide as part of an experimental protocol to control int...
journal_title：Clinical chemistry
pub_type： 杂志文章
doi：
更新日期：1980-11-01 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：: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：:We describe a simple method for evaluating thyroxine-binding globulin capacity and concentration from a single 1-cm blood spot on filter-paper used in a screening program for neonatal hypothyroidism. This method permits prompt diagnosis of about 90% of the infants with thyroxine-binding globulin deficiency in our abno...
journal_title：Clinical chemistry
pub_type： 杂志文章
doi：
更新日期：1980-03-01 00:00:00
abstract：BACKGROUND:Patients with trophoblastic diseases produce ordinary and irregular forms of human chorionic gonadotropin (hCG; e.g., nicked hCG, hCG missing the beta-subunit C-terminal segment, hyperglycosylated hCG, and free beta subunit) that are recognized to differing extents by automated immunometric hCG (or hCG beta)...
journal_title：Clinical chemistry
pub_type： 杂志文章
doi：
更新日期：2001-02-01 00:00:00
abstract：:We have developed a simple, specific, and sensitive reversed-phase liquid-chromatographic method for accurate and simultaneous analysis of corticosterone and cortisol in human plasma. We achieved a detection limit of 300 ng/L for both steroids by modifying the old solid-phase extraction method to make use of "Tef Elut...
journal_title：Clinical chemistry
pub_type： 杂志文章
doi：
更新日期：1992-03-01 00:00:00
abstract：:Recombinant DNA techniques are contributing to the understanding of the pathogeneses of genetic, neoplastic, and viral diseases, and are used in the diagnosis of certain genetic and viral diseases. Such techniques will have wider application in the future and will play an increasing role in the clinical laboratory. Th...
journal_title：Clinical chemistry
pub_type： 杂志文章
doi：
更新日期：1985-06-01 00:00:00
abstract：:We examined the mechanism by which hypertriglyceridemia interferes with the Roche Diagnostics "Amylochrome" procedure for measurement of amylase in lactescent samples with normal and above-normal amylase activity. The serum blank recommended in the Amylochrome protocol to compensate for lactescence remains inappropria...
journal_title：Clinical chemistry
pub_type： 杂志文章
doi：
更新日期：1982-10-01 00:00:00
abstract：:We examined the relationship in a large-living population between the concentration of triglycerides in plasma from fasting persons and the concentration of very-low-density lipoprotein cholesterol (VLDL-C) as determined after preparative ultracentrifugation. Data from individuals in the Framingham Heart Study who wer...
journal_title：Clinical chemistry
pub_type： 杂志文章
doi：
更新日期：1981-12-01 00:00:00
abstract：:In the Prospective Cardiovascular Münster (PROCAM) study, serum lipoprotein(a) [Lp(a)] and its relationship to pro- and anticoagulatory as well as fibrinolytic indices were determined in a large group of employees: 864 men (m) and 373 women (f), ages 16-65 years. Univariate statistical analysis showed Lp(a) concentrat...
journal_title：Clinical chemistry
pub_type： 杂志文章
doi：
更新日期：1991-11-01 00:00:00
abstract：BACKGROUND:Tamoxifen is a standard endocrine therapy for the prevention and treatment of steroid hormone receptor-positive breast cancer. CONTENT:Tamoxifen requires enzymatic activation by cytochrome P450 (CYP) enzymes for the formation of active metabolites 4-hydroxytamoxifen and endoxifen. As compared with the paren...
journal_title：Clinical chemistry
pub_type： 杂志文章,评审
doi：10.1373/clinchem.2008.121756
更新日期：2009-10-01 00:00:00
