Abstract:
BACKGROUND:The discovery of cell-free fetal DNA in maternal plasma has opened up new possibilities for noninvasive prenatal diagnosis and monitoring. Among the fetal markers that have been described, methylation markers are sex and polymorphism independent. Methylation-sensitive restriction endonucleases are commonly used to digest hypomethylated DNA molecules, and the hypermethylated molecules remain intact for detection. The positive detection of the cleaved hypomethylated molecules would be useful for certain targets but has not been reported. METHODS:The use of a stem-loop primer in microRNA detection has previously been described. In this study, DNA assays were designed and performed on maternal plasma, which contained the hypomethylated placental serpin peptidase inhibitor, clade B (ovalbumin), member 5 (SERPINB5; maspin) gene in an excess background of hypermethylated maternal SERPINB5. Detection of the enzyme-digested placenta-derived hypomethylated SERPINB5 molecules was achieved by performing stem-loop extension followed by real-time PCR on maternal plasma. The placental origin of the stem-loop-extended SERPINB5 molecules was confirmed by genotyping. RESULTS:From the real-time PCR results on maternal plasma, stem-loop-extended SERPINB5 promoter sequences were detectable in all 11 enzyme-digested predelivery maternal plasma samples. Postpartum clearance was demonstrated. In 9 cases in which the fetal and maternal SERPINB5 genotypes were distinguishable, the placental-specific genotypes were detected in all predelivery maternal plasma samples. CONCLUSION:Detection of restriction enzyme-digested hypomethylated placental DNA molecules in maternal plasma by the use of a stem-loop primer represents a novel approach in fetal epigenetic marker detection. The analytical approach may also be generally applicable to the detection of restriction enzyme-digested nucleic acid fragments.
journal_name
Clin Chemjournal_title
Clinical chemistryauthors
Tong YK,Chiu RW,Leung TY,Ding C,Lau TK,Leung TN,Lo YMdoi
10.1373/clinchem.2007.092619subject
Has Abstractpub_date
2007-11-01 00:00:00pages
1906-14issue
11eissn
0009-9147issn
1530-8561pii
clinchem.2007.092619journal_volume
53pub_type
杂志文章abstract:BACKGROUND:Myeloperoxidase (MPO) is a biomarker of inflammation and oxidative stress produced by neutrophils, monocytes, and endothelial cells. Concentrations of MPO predict mortality in patients with chronic heart failure. This study sought to investigate the diagnostic accuracy and prognostic value of MPO in patients...
journal_title:Clinical chemistry
pub_type: 杂志文章
doi:10.1373/clinchem.2009.142257
更新日期:2010-06-01 00:00:00
abstract:BACKGROUND:Paraoxonase may mitigate oxidative damage and thus lower risk of macrovascular disease. METHODS:DNA samples from 2252 participants in the Coronary Artery Risk Development in Young Adults (CARDIA) study were genotyped for the L55M and Q192R polymorphisms of the PON1 (paraoxonase 1) gene, and paraoxonase acti...
journal_title:Clinical chemistry
pub_type: 杂志文章,多中心研究
doi:10.1373/clinchem.2007.099044
更新日期:2008-04-01 00:00:00
abstract::We evaluated "borderline" increases in overnight albumin excretion rates (AERs)----i.e., those between the upper 95th percentile of normal (7.6 micrograms/min) and the lowest value currently considered predictive of nephropathy (30 micrograms/min)----to determine their importance and to see whether glucose control inf...
journal_title:Clinical chemistry
pub_type: 杂志文章
doi:
更新日期:1991-12-01 00:00:00
abstract::We examined the comparative behavior of subject-specific multivariate and univariate reference regions, using both computer-generated data and serial (semi-annual) measurements of selected analytes in subjects from a large health-maintenance program. Univariate studies under both homeostatic and random-walk time-serie...
journal_title:Clinical chemistry
pub_type: 杂志文章
doi:
更新日期:1982-03-01 00:00:00
abstract::Investigating the interference of danazol in testosterone radioimmunoassays, we measured serum testosterone concentrations in the serum of women receiving danazol, with three testosterone radioimmunoassay kits. All of these showed positive interference by danazol or its metabolites (or both). Values for testosterone o...
journal_title:Clinical chemistry
pub_type: 杂志文章
doi:
更新日期:1983-01-01 00:00:00
abstract::To secure a successful product in today's era of cost containment, manufacturers and developers of new in vitro diagnostic technologies must consider payment issues--coverage and reimbursement by healthcare insurers--as critical market forces that must be addressed in the business plan. Similar to the regulatory hurdl...
journal_title:Clinical chemistry
pub_type: 杂志文章
doi:
更新日期:1996-09-01 00:00:00
abstract::This rapid radioimmunoassay for aldosterone is performed directly on 100 microL of unprocessed plasma, with 125I-labeled aldosterone as the labeled antigen. Our use of steroid-free plasma in preparing the standard curve resulted in an overestimate of aldosterone; this problem was overcome by adding to such plasma a mi...
journal_title:Clinical chemistry
pub_type: 杂志文章
doi:
更新日期:1983-02-01 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::We describe a gas--liquid-chromatographic method for determining the concentration of amantadine hydrochloride in urine with beta-phenylethylamine as internal standard. The urine sample is made alkaline and extracted with 0.5 mL of chloroform. After centrifugation the aqueous layer is aspirated, and an aliquot of the ...
journal_title:Clinical chemistry
pub_type: 杂志文章
doi:
更新日期:1980-02-01 00:00:00
abstract::If there were enzymatically inactive B subunits in a solution containing lactate dehydrogenase (LD) B4 prepared from the hemolysates of heterozygous individuals with LD-B subunit deficiency, the inactive subunits would compete with normal subunits for antibodies to the B4 subunit. Using the activity of normal LD-B4 as...
journal_title:Clinical chemistry
pub_type: 杂志文章
doi:
更新日期:1986-01-01 00:00:00
abstract::The contribution of the exocrine pancreas to hyperamylasemia in diabetic ketoacidosis was investigated by measuring total amylase, salivary and pancreatic isoamylases, cathodic trypsin-like immunoreactivity, and pancreatic lipase in 12 consecutive patients recovering from diabetic ketoacidosis. Hyperamylasemia was pre...
journal_title:Clinical chemistry
pub_type: 杂志文章
doi:
更新日期:1985-12-01 00:00:00
abstract::We describe a two-site time-resolved immunofluorometric assay for guinea pig vascular permeability factor (VPF) for quantifying VPF in different biological fluids. Antibody against the carboxy terminus (C-IgG) is immobilized on microtiter wells, and antibody against the amino terminus (N-IgG) is labeled with Eu(3+)-ch...
journal_title:Clinical chemistry
pub_type: 杂志文章
doi:
更新日期:1992-01-01 00:00:00
abstract::We studied the pattern of acute-phase proteins (orosomucoid, C-reactive protein, and haptoglobin) in hepatocellular deficiency due to chronic alcohol consumption, characterized by a decrease in serum transferrin concentration. We found that their patterns could vary independently of hepatocellular deficiency, but depe...
journal_title:Clinical chemistry
pub_type: 杂志文章
doi:
更新日期:1983-01-01 00:00:00
abstract::We present data on a filter-paper collection and assay method for measurement of glycated hemoglobin (gHb). Onto filter paper dipped into a solution of glucose oxidase (EC 1.1.3.4) and allowed to dry, approximately 20 microL of capillary blood was spotted. For analysis, we eluted the dried blood spot from the paper by...
journal_title:Clinical chemistry
pub_type: 杂志文章
doi:
更新日期:1986-05-01 00:00:00
abstract:BACKGROUND:Total prostate-specific antigen (tPSA) is flawed for prostate cancer (PCa) detection. [-2]proprostate-specific antigen (p2PSA), a molecular isoform of free PSA (fPSA), shows higher specificity compared with tPSA or percentage of free PSA (%fPSA). The prostate health index (Phi), a measure based on p2PSA and ...
journal_title:Clinical chemistry
pub_type: 杂志文章,多中心研究
doi:10.1373/clinchem.2012.195784
更新日期:2013-01-01 00:00:00
abstract:BACKGROUND:About 5% of patients with neurofibromatosis type 1 (NF1) bear constitutional microdeletions that encompass NF1 (neurofibromin 1) and neighboring genes. These patients are characterized by the development of a high number of dermal neurofibromas (dNFs), mental retardation, and an increased risk of developing ...
journal_title:Clinical chemistry
pub_type: 杂志文章
doi:10.1373/clinchem.2012.194217
更新日期:2013-06-01 00:00:00
abstract::Six different procedures for radioiodination of mouse epidermal growth factor (EGF) all resulted in a heterogeneous 125I-labeled EGF preparation, as analyzed by reversed-phase HPLC. EGF preparations that had been iodinated with Chloramine T, lodogen, or lodo-beads were found mainly to consist of oxidized 125I-labeled ...
journal_title:Clinical chemistry
pub_type: 杂志文章
doi:
更新日期:1992-05-01 00:00:00
abstract:BACKGROUND:Concomitant quantification of multiple mutant KRAS (v-Ki-ras2 Kirsten rat sarcoma viral oncogene homolog) alleles may provide information in addition to that provided by standard mutation-detection procedures. We assessed the feasibility of a nanofluidic digital PCR array platform to detect and quantify KRAS...
journal_title:Clinical chemistry
pub_type: 杂志文章
doi:10.1373/clinchem.2012.186577
更新日期:2012-09-01 00:00:00
abstract::We present an improved fructosamine assay for use with the Technicon RA-1000 analyzer. Features of this assay include: specimen throughput of 100 per hour, within-batch CV of 1.5%, between-batch CV of 2.4%, standard curve linear up to 24.9 mmol of fructosamine per liter, and good correlation (r = 0.82) with hemoglobin...
journal_title:Clinical chemistry
pub_type: 杂志文章
doi:
更新日期:1985-12-01 00:00:00
abstract::I describe a micro-scale method for determining lead in whole blood by utilizing a graphite furnace. Sample pretreatment consists of fivefold dilution with a dilute surfactant. The method is directly calibrated with lead standards prepared in dilute HNO3. To eliminate a small, nonspecific absorption signal from the...
journal_title:Clinical chemistry
pub_type: 杂志文章
doi:
更新日期:1975-04-01 00:00:00
abstract::We report spectrophotometric methods for quantifying sodium and potassium in serum and plasma without sample pretreatment or solvent-extraction steps. The methods are based on novel chromogenic ionophores characterized by molecular structures highly preorganized for binding, which result in exceptionally high sensitiv...
journal_title:Clinical chemistry
pub_type: 杂志文章
doi:
更新日期:1988-09-01 00:00:00
abstract:BACKGROUND:Little is known about trace metal alterations in the bones of dialysis patients or whether particular types of renal osteodystrophy are associated with either increased or decreased skeletal concentrations of trace elements. Because these patients are at risk for alterations of trace elements as well as for ...
journal_title:Clinical chemistry
pub_type: 杂志文章,多中心研究
doi:
更新日期:1999-09-01 00:00:00
abstract::A radioimmunoassay for barbiturates is shown to be equally sensitive to phenobarbital and its major urinary metabolite, p-hydroxyphenobarbital, in serum and urine. Interference by the metabolite can be essentially eliminated by selectively extracting phenobarbital into chloroform. The extraction efficiency of the meth...
journal_title:Clinical chemistry
pub_type: 杂志文章
doi:
更新日期:1977-05-01 00:00:00
abstract::Biological variation is inherent in all medical tests and is a major source of error in clinical test interpretation. We use inherent test error due to biological variability as the touchstone by which to validate the clinical acceptability of analytical goals. Analytical goals should consist of sets of complementary ...
journal_title:Clinical chemistry
pub_type: 杂志文章,评审
doi:
更新日期:1993-07-01 00:00:00
abstract:BACKGROUND:We evaluated the completeness of reporting of diagnostic test accuracy (DTA) systematic reviews using the recently developed Preferred Reporting Items for Systematic Reviews and MetaAnalyses (PRISMA)-DTA guidelines. METHODS:MEDLINE® was searched for DTA systematic reviews published October 2017 to January 2...
journal_title:Clinical chemistry
pub_type: 杂志文章,meta分析
doi:10.1373/clinchem.2018.292987
更新日期:2019-02-01 00:00:00
abstract:BACKGROUND:High-resolution DNA melting analysis of small amplicons is a simple and inexpensive technique for genotyping. Microfluidics allows precise and rapid control of temperature during melting. METHODS:Using a microfluidic platform for serial PCR and melting analysis, 4 targets containing single nucleotide varian...
journal_title:Clinical chemistry
pub_type: 杂志文章
doi:10.1373/clinchem.2017.276147
更新日期:2017-10-01 00:00:00
abstract::A potential genetic marker for hypertriglyceridemia and coronary disease, an apolipoprotein-CIII gene allele displaying a single nucleotide substitution, was found in 71% of Arabs with primary hypertriglyceridemia. Over 96% of the unrelated adults possessing this allele showed hypertriglyceridemia. The same allele was...
journal_title:Clinical chemistry
pub_type: 杂志文章
doi:
更新日期:1989-02-01 00:00:00
abstract::We have used a monoclonal antibody-based ELISA for plasma prothrombin fragment 1.2 (F1.2) to establish appropriate sample collection and storage conditions for this biomarker of thrombin generation. F1.2 concentrations were not altered by exogenous factor Xa, thrombin, or thromboplastin if blood was collected by routi...
journal_title:Clinical chemistry
pub_type: 杂志文章
doi:
更新日期:1994-10-01 00:00:00
abstract::Single-strand conformation polymorphism (SSCP) analysis is widely used to prescreen mutations in p53 gene. However, standardization of SSCP to detect p53 mutations has rarely been pursued so far. We have developed complete conditions for a temperature-controlled nonradioactive SSCP for mutation detection in amplified ...
journal_title:Clinical chemistry
pub_type: 杂志文章
doi:
更新日期:1997-12-01 00:00:00
abstract::Numerous outcome measures can be used to characterize and compare the performance of alternative quality-control (QC) strategies. The performance measure traditionally used in the QC planning process is the probability of rejecting an analytical run when a critical out-of-control error condition exists. Another perfor...
journal_title:Clinical chemistry
pub_type: 杂志文章
doi:
更新日期:1997-04-01 00:00:00