Abstract:
BACKGROUND:C-peptide is a marker of insulin secretion in diabetic patients. We assessed within- and between-laboratory imprecision of C-peptide assays and determined whether serum calibrators with values assigned by mass spectrometry could be used to harmonize C-peptide results. METHODS:We sent 40 different serum samples to 15 laboratories, which used 9 different routine C-peptide assay methods. We also sent matched plasma samples to another laboratory for C-peptide analysis with a reference mass spectrometry method. Each laboratory analyzed 8 of these samples in duplicate on each of 4 days to evaluate within- and between-day imprecision. The same 8 samples were also used to normalize the results for the remaining samples to the mass spectrometry reference method. RESULTS:Within- and between-run CVs ranged from <2% to >10% and from <2% to >18%, respectively. Normalizing the results with serum samples significantly improved the comparability among laboratories and methods. After normalization, the differences among laboratories in mean response were no longer statistically significant (P = 0.24), with least-squares means of 0.93-1.02. CONCLUSIONS:C-peptide results generated by different methods and laboratories do not always agree, especially at higher C-peptide concentrations. Within-laboratory imprecision also varied, with some methods giving much more consistent results than others. These data show that calibrating C-peptide measurement to a reference method can increase comparability between laboratories.
journal_name
Clin Chemjournal_title
Clinical chemistryauthors
Little RR,Rohlfing CL,Tennill AL,Madsen RW,Polonsky KS,Myers GL,Greenbaum CJ,Palmer JP,Rogatsky E,Stein DTdoi
10.1373/clinchem.2007.101287subject
Has Abstractpub_date
2008-06-01 00:00:00pages
1023-6issue
6eissn
0009-9147issn
1530-8561pii
clinchem.2007.101287journal_volume
54pub_type
杂志文章,多中心研究abstract::We evaluated the EMIT Cyclosporine Assay (Syva Co., Palo Alto, CA), using the Cobas-Mira analyzer to assess the precision, accuracy, and analytical recovery from whole-blood samples supplemented with cyclosporine. We also performed comparative analysis of whole-blood samples containing cyclosporine from liver and kidn...
journal_title:Clinical chemistry
pub_type: 杂志文章
doi:
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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
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doi:10.1373/clinchem.2013.214213
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journal_title:Clinical chemistry
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journal_title:Clinical chemistry
pub_type: 杂志文章
doi:
更新日期:1986-01-01 00:00:00
abstract::We developed a new colorimetric method, DNA enzyme immunoassay (DEIA), for detecting specific hybrids of complementary nucleic acids and applied it to the detection of hepatitis B virus (HBV) DNA amplified from serum samples by means of the polymerase chain reaction (PCR) technique. The method is based on the ability ...
journal_title:Clinical chemistry
pub_type: 杂志文章
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更新日期:1991-03-01 00:00:00
abstract::We have explored the method of Rapoport et al. (J Clin Endocrinol Metab 1984;58:332-8) for the bioassay of thyroid-stimulating immunoglobulin (TSI) in cultured human thyroid cells, to optimize the assay and to evaluate its utility in clinical diagnosis and management of patients with autoimmune thyroid disease. Here w...
journal_title:Clinical chemistry
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journal_title:Clinical chemistry
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doi:
更新日期:1980-04-01 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
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journal_title:Clinical chemistry
pub_type: 杂志文章
doi:
更新日期:1990-08-01 00:00:00
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journal_title:Clinical chemistry
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journal_title:Clinical chemistry
pub_type: 杂志文章
doi:
更新日期:1995-02-01 00:00:00
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journal_title:Clinical chemistry
pub_type: 杂志文章
doi:
更新日期:1990-06-01 00:00:00
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journal_title:Clinical chemistry
pub_type: 杂志文章
doi:
更新日期:2001-04-01 00:00:00
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journal_title:Clinical chemistry
pub_type: 杂志文章
doi:
更新日期:1998-07-01 00:00:00
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journal_title:Clinical chemistry
pub_type: 杂志文章
doi:
更新日期:1993-09-01 00:00:00
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journal_title:Clinical chemistry
pub_type: 杂志文章
doi:
更新日期:1981-02-01 00:00:00
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journal_title:Clinical chemistry
pub_type: 杂志文章
doi:
更新日期:1997-05-01 00:00:00
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journal_title:Clinical chemistry
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doi:10.1373/clinchem.2005.065581
更新日期:2006-06-01 00:00:00
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journal_title:Clinical chemistry
pub_type: 杂志文章
doi:
更新日期:1982-04-01 00:00:00
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journal_title:Clinical chemistry
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更新日期:1996-01-01 00:00:00
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journal_title:Clinical chemistry
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doi:
更新日期:2000-10-01 00:00:00
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journal_title:Clinical chemistry
pub_type: 杂志文章
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更新日期:1982-01-01 00:00:00
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journal_title:Clinical chemistry
pub_type: 杂志文章
doi:
更新日期:1982-04-01 00:00:00
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journal_title:Clinical chemistry
pub_type: 杂志文章,评审
doi:
更新日期:1986-08-01 00:00:00
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journal_title:Clinical chemistry
pub_type: 杂志文章
doi:
更新日期:1983-01-01 00:00:00
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journal_title:Clinical chemistry
pub_type: 杂志文章
doi:
更新日期:1985-03-01 00:00:00
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journal_title:Clinical chemistry
pub_type: 杂志文章
doi:
更新日期:1975-01-01 00:00:00
abstract::A new method for the reliable identification of localized variations in DNA by detection of associated diagnostic products with matrix-assisted laser desorption ionization time-of-flight mass spectrometry is described. The diagnostic products are generated by the primer oligo base extension (PROBE) reaction, which req...
journal_title:Clinical chemistry
pub_type: 杂志文章
doi:
更新日期:1997-07-01 00:00:00
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journal_title:Clinical chemistry
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