Abstract：
BACKGROUND:The TDx Fetal Lung Maturity II (FLM II) assay uses amniotic fluid to assess lung maturity of the unborn infant. We investigated common preanalytical factors that influence FLM results, including centrifugation, sample storage, and contamination by whole blood. METHODS:We tested 18 specimens after centrifugation and after resuspension by vortex-mixing. We also analyzed 23 specimens stored at -20 degrees C for up to 448 days and then thawed (duplicate measurements), 20 specimens stored at 4 degrees C, and 24 specimens stored at room temperature. In addition, we evaluated the effects of whole blood diluted into 19 different specimens. RESULTS:Centrifugation significantly decreased FLM II results from baseline (P <0.0001), and resuspension returned results to baseline values (P = 0.286). Storage at -20 degrees C produced highly variable results that demonstrated a nonsignificant negative trend associated with storage time. Specimens were stable for 24 h when stored at 4 degrees C and 16 h at room temperature. Blood contamination produced significantly positive differences in results only in specimens with baseline values < or =39 mg/g with a 5.8 mg/g increase in FLM II for every 0.1 x 10(12)/L increase in the erythrocyte count (slope = 58.4). CONCLUSIONS:Resuspension of centrifuged specimens produces clinically valid FLM II results. Results from specimens stored at -20 degrees C can be highly variable and decrease over time. Results from specimens stored at 4 degrees C and at room temperature are stable for 24 and 16 h, respectively. Blood contamination up to 0.03 x 10(12) erythrocytes/L is acceptable for FLM II analysis.
journal_name
Clin Chemjournal_title
Clinical chemistryauthors
Grenache DG,Parvin CA,Gronowski AMdoi
10.1373/49.6.935subject
Has Abstractpub_date
2003-06-01 00:00:00pages
935-9issue
6 Pt 1eissn
0009-9147issn
1530-8561journal_volume
49pub_type
杂志文章abstract：:The location of the Reference Value for an analyte within the population distribution affects the magnitude of error due to methodological bias. Using the gaussian distribution, we evaluated the effects of systematic and proportional biases of the method (positive and negative), mean value, and standard deviation on t...
journal_title：Clinical chemistry
pub_type： 杂志文章
doi：
更新日期：1988-11-01 00:00:00
abstract：BACKGROUND:Protein tyrosine phosphatase 1B (PTPN1) dephosphorylates insulin receptors and attenuates insulin signaling. Polymorphisms in the coding sequence of PTPN1 have been variably associated with type 2 diabetes (T2D). We hypothesized that variations within the PTPN1 promoter might contribute to the development of...
journal_title：Clinical chemistry
pub_type： 杂志文章
doi：10.1373/clinchem.2007.088146
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journal_title：Clinical chemistry
pub_type： 杂志文章
doi：
更新日期：1983-07-01 00:00:00
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journal_title：Clinical chemistry
pub_type： 杂志文章
doi：10.1373/49.2.269
更新日期：2003-02-01 00:00:00
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journal_title：Clinical chemistry
pub_type： 杂志文章
doi：
更新日期：1990-03-01 00:00:00
abstract：:We measured cyclosporine in whole blood from normal volunteers administered single oral doses of the drug and from two renal-transplant patients on immunosuppressive maintenance therapy, by liquid chromatography (I) and by radioimmunoassay with use of nonspecific polyclonal (II), specific monoclonal (III), and nonspec...
journal_title：Clinical chemistry
pub_type： 杂志文章
doi：
更新日期：1987-12-01 00:00:00
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journal_title：Clinical chemistry
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doi：
更新日期：1998-03-01 00:00:00
abstract：BACKGROUND:Hypoxic ischemic encephalopathy (HIE) is a major cause of permanent neurological disabilities in full-term newborns. We measured activin A in urine collected immediately after birth in asphyxiated full-term newborns, and assessed the ability of the measurements to predict the occurrence of perinatal encephal...
journal_title：Clinical chemistry
pub_type： 杂志文章
doi：10.1373/clinchem.2005.062604
更新日期：2007-03-01 00:00:00
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journal_title：Clinical chemistry
pub_type： 杂志文章
doi：
更新日期：1983-03-01 00:00:00
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doi：10.1373/clinchem.2013.213264
更新日期：2014-02-01 00:00:00
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journal_title：Clinical chemistry
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doi：
更新日期：1975-11-01 00:00:00
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journal_title：Clinical chemistry
pub_type： 临床试验,杂志文章,多中心研究
doi：
更新日期：1999-10-01 00:00:00
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journal_title：Clinical chemistry
pub_type： 杂志文章
doi：10.1373/clinchem.2004.036863
更新日期：2004-11-01 00:00:00
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journal_title：Clinical chemistry
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doi：
更新日期：2001-06-01 00:00:00
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doi：10.1093/clinchem/hvaa207
更新日期：2020-11-01 00:00:00
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journal_title：Clinical chemistry
pub_type： 杂志文章
doi：10.1373/clinchem.2012.193060
更新日期：2013-01-01 00:00:00
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journal_title：Clinical chemistry
pub_type： 杂志文章
doi：
更新日期：1990-01-01 00:00:00
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doi：
更新日期：2000-09-01 00:00:00
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journal_title：Clinical chemistry
pub_type： 杂志文章
doi：
更新日期：1984-12-01 00:00:00
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journal_title：Clinical chemistry
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doi：
更新日期：1988-02-01 00:00:00
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doi：
更新日期：1992-11-01 00:00:00
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doi：
更新日期：1977-05-01 00:00:00
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doi：
更新日期：1987-10-01 00:00:00
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doi：
更新日期：1976-10-01 00:00:00
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doi：
更新日期：1997-02-01 00:00:00
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doi：
更新日期：1992-09-01 00:00:00
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doi：
更新日期：1998-08-01 00:00:00
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journal_title：Clinical chemistry
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doi：
更新日期：1980-03-01 00:00:00
