Abstract：
BACKGROUND:Standardization of clinical measurements of C-reactive protein (CRP) is based on the availability of reference materials. The serum protein reference material ERM-DA470 was used as a calibrant for various commercially available immunoassays but has now been exhausted. The recently released ERM-DA470k/IFCC was intended to fully replace ERM-DA470. However, the new material was not suited for the certification of CRP because of a bias introduced by the lyophilization process that caused loss of about 20% of CRP measurable by routine immunoassays, compared with the nonlyophilized material that was stored in a liquid frozen state. METHODS:We investigated the physicochemical state of CRP in a set of 4 lyophilized and 2 nonlyophilized serum-based CRP-containing materials by semi-native gel electrophoresis, Western blotting, and gel filtration. RESULTS:We detected a monomeric form of CRP (mCRP) in lyophilized materials at a concentration significantly higher than seen in the materials not subjected to lyophilization. Different reconstitution protocols led to variations of the monomeric CRP fraction found in reconstituted, previously lyophilized material. CONCLUSIONS:Most of the 20% loss in measured CRP after lyophilization of the material can be accounted for by the dissociation of natively pentameric CRP into subunits. The observed dissociation results from lyophilization and subsequent reconstitution of the material at insufficient concentration levels of calcium ions. In the presence of various protein forms, differences in antibody specificity and reactivity between immunoassays and alterations of stoichiometry of antigen-antibody interactions can contribute to the divergence of the measured values.
journal_name
Clin Chemjournal_title
Clinical chemistryauthors
Rzychon M,Zegers I,Schimmel Hdoi
10.1373/clinchem.2010.147124subject
Has Abstractpub_date
2010-09-01 00:00:00pages
1475-82issue
9eissn
0009-9147issn
1530-8561pii
clinchem.2010.147124journal_volume
56pub_type
杂志文章abstract：:A new method (enzyme-ligand immunoassay, ELIA) is described for the estimation of estrogen (ER) and progesterone (PR) receptors in microsamples of human breast cancer tissue. The technique, based on the nonisotopic measurement of receptor-bound estradiol and progesterone, involves three steps: (a) simultaneous saturat...
journal_title：Clinical chemistry
pub_type： 杂志文章
doi：
更新日期：1995-01-01 00:00:00
abstract：:9-(2-Phosphonylmethoxyethyl)adenine (PMEA), (S)-9-(3-hydroxy-2-phosphonylmethoxypropyl)adenine (HPMPA), and (R,S)-9-(3-fluoro-2-phosphonylmethoxypropyl)adenine (FPMPA) are selective antiviral agents with activity against a broad spectrum of DNA viruses and retroviruses. A highly sensitive method has been developed to ...
journal_title：Clinical chemistry
pub_type： 杂志文章
doi：
更新日期：1992-04-01 00:00:00
abstract：BACKGROUND:Hyperhomocysteinemia (HHcy) has been linked to impaired left ventricular function and clinical class in patients with chronic heart failure. We hypothesized that HHcy stimulates myocardial brain natriuretic peptide (BNP) expression and induces adverse left ventricular remodeling. METHODS:We randomized 50 ra...
journal_title：Clinical chemistry
pub_type： 杂志文章
doi：10.1373/clinchem.2006.077859
更新日期：2007-04-01 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:Distinguishing adenocarcinoma and squamous cell carcinoma subtypes of non-small cell lung cancers is critical to patient care. Preoperative minimally-invasive biopsy techniques, such as fine needle aspiration (FNA), are increasingly used for lung cancer diagnosis and subtyping. Yet, histologic distinction of...
journal_title：Clinical chemistry
pub_type： 杂志文章
doi：10.1093/clinchem/hvaa207
更新日期：2020-11-01 00:00:00
abstract：:We compared a selection of quantitative immunological methods for prostatic acid phosphatase (PAP) with routine colorimetric assays for total and tartrate-labile acid phosphatase and evaluated their relative clinical merits in the differential diagnosis of prostatic carcinoma. We also assessed a wide range of commerci...
journal_title：Clinical chemistry
pub_type： 杂志文章
doi：
更新日期：1986-09-01 00:00:00
abstract：:This two-site immunoradiometric assay for human parathyrin-related protein 1-86 (PTHRP1-86) in plasma uses a mouse monoclonal antibody to PTHRP1-34 coupled to cellulose particles for immunoextraction of N-terminal immunoreactivity, and a rabbit antiserum to PTHRP37-67 that is indirectly labeled with 125I-labeled PTHRP...
journal_title：Clinical chemistry
pub_type： 杂志文章
doi：
更新日期：1991-05-01 00:00:00
abstract：:I describe the automation/mechanization of several areas of sample processing at SmithKline Beecham Clinical Laboratories. By analyzing and implementing new systems for conveyance and sorting of incoming specimens, specimen processing, within-laboratory specimen delivery, specimen storage and retrieval, and client res...
journal_title：Clinical chemistry
pub_type： 杂志文章
doi：
更新日期：1990-09-01 00:00:00
abstract：BACKGROUND:Little research has been done to examine whether gamma-glutamyltransferase (GGT) is prospectively associated with the development of chronic kidney disease (CKD). We performed a prospective study to examine the association between GGT and the risk for the development of CKD. METHODS:The study cohort include...
journal_title：Clinical chemistry
pub_type： 杂志文章
doi：10.1373/clinchem.2006.078980
更新日期：2007-01-01 00:00:00
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journal_title：Clinical chemistry
pub_type： 杂志文章
doi：
更新日期：1996-12-01 00:00:00
abstract：:Clinicians experience difficulty in correctly interpreting the results of in vitro thyroid function tests in the presence of abnormalities of thyrobinding proteins or when results are borderline. This difficulty has been largely resolved in our laboratory by three innovations. First, the borderline areas for each of t...
journal_title：Clinical chemistry
pub_type： 杂志文章
doi：
更新日期：1976-10-01 00:00:00
abstract：:We evaluated a new agarose-gel-electrophoretic procedure (Corning) (I) for separating and quantitating of high-density lipoprotein cholesterol (HDLC), comparing it with the modified Lipid Research Clinics (LRC) procedure (heparin 183 kilounits/L, MnCl2 92 mmol/L) (II). Method I was insensitive to an HDLC concentration...
journal_title：Clinical chemistry
pub_type： 杂志文章
doi：
更新日期：1979-11-01 00:00:00
abstract：:We describe the sensitive and precise determination 5-hydroxytryptophan in plasma from patients treated with this compound. The method is based on solvent extraction of plasma, high-performance liquid chromatography and continuous fluorometric detection after reaction with phthaldialdehyde in strong acid. The combined...
journal_title：Clinical chemistry
pub_type： 杂志文章
doi：
更新日期：1978-02-01 00:00:00
abstract：:We report the accuracy, imprecision, total analytical errors, and patient misclassification errors for cholesterol measured from capillary whole blood, venous whole blood, and venous plasma samples by five devices used in public cholesterol screening environments: Reflotron, Vision, Ektachem DT-60, QuickRead, and Lipo...
journal_title：Clinical chemistry
pub_type： 杂志文章
doi：
更新日期：1993-02-01 00:00:00
abstract：:Noninvasive monitoring of blood/tissue glucose concentrations has been successfully accomplished in individual diabetic subjects by using near-infrared (NIR) spectroscopy coupled with chemometric methods. Three different spectrometer configurations were tested: a) a Fourier-transform infrared spectrometer with an indi...
journal_title：Clinical chemistry
pub_type： 杂志文章
doi：
更新日期：1992-09-01 00:00:00
abstract：:In this clinically useful enzyme immunoassay of digoxin in serum, we mix sample, beta-galactosidase-labeled digoxin, and anti-digoxin Fab fragments for 30 min at room temperature, then use Sepharose-bound second antibody for phase separation, and measure the unbound enzyme activity directly in the supernate of the equ...
journal_title：Clinical chemistry
pub_type： 杂志文章
doi：
更新日期：1986-01-01 00:00:00
abstract：:Urinary acidic and alcoholic catecholamine metabolites were isolated separately from 24-h urines by simple extraction procedures. After derivatization, extracts were analyzed by means of simultaneous gas chromatography on two different stationary phases. The quality of the assay was checked by running "normal" and enr...
journal_title：Clinical chemistry
pub_type： 杂志文章
doi：
更新日期：1977-05-01 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：BACKGROUND:Increased plasma lipoprotein(a) [Lp(a)] concentrations have been reported to be an independent risk factor for coronary heart disease (CHD) in some prospective studies, but not in others. These inconsistencies may relate to a lack of standardization and the failure of some immunoassays to measure all apolipo...
journal_title：Clinical chemistry
pub_type： 临床试验,杂志文章
doi：
更新日期：1999-07-01 00:00:00
abstract：:We compared cyclosporine concentrations in whole blood as measured by HPLC and by RIA with a monoclonal antibody specific for cyclosporine with 3H- or 125I-labeled cyclosporine ligand. The 3H-RIA kit slightly underestimated cyclosporine concentrations (greater than 600 micrograms/L) in comparison with HPLC. Over a wid...
journal_title：Clinical chemistry
pub_type： 杂志文章
doi：
更新日期：1989-01-01 00:00:00
abstract：:A simple, precise, and rapid method to measure plasma malondialdehyde (MDA) was developed by use of solvent extraction--flow-injection analysis. The reagent solution, containing thiobarbituric acid (TBA), 5 g/L in 100 mL/L phosphoric acid, and extraction solvent (methylisobutyl ketone, MIBK) were propelled with a doub...
journal_title：Clinical chemistry
pub_type： 杂志文章
doi：
更新日期：1992-10-01 00:00:00
abstract：BACKGROUND:Plasma amino acid (PAA) profiles are used in routine clinical practice for the diagnosis and monitoring of inherited disorders of amino acid metabolism, organic acidemias, and urea cycle defects. Interpretation of PAA profiles is complex and requires substantial training and expertise to perform. Given previ...
journal_title：Clinical chemistry
pub_type： 杂志文章
doi：10.1093/clinchem/hvaa134
更新日期：2020-09-01 00:00:00
abstract：:We find lag phases exceeding 20 min in measuring creatine kinase activity, by using the kinetic creatin phosphate leads to creatine assay, in sera of some patients with carcinoma metastatic to the liver. Such long lag phases are accompanied by a decreased apparent enzyme activity. These problems are eliminated by addi...
journal_title：Clinical chemistry
pub_type： 杂志文章
doi：
更新日期：1976-11-01 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：BACKGROUND:The time required for bloodstream pathogen detection, identification (ID), and antimicrobial susceptibility testing (AST) does not satisfy the acute needs of disease management. Conventional methods take up to 3 days for ID and AST. Molecular diagnostics have reduced times for ID, but their promise to suppla...
journal_title：Clinical chemistry
pub_type： 杂志文章
doi：10.1373/clinchem.2018.290189
更新日期：2018-10-01 00:00:00
abstract：:Taurine was measured in cerebrospinal fluid by reacting it with fluorescamine to form a fluorescent derivative, followed by separation on a reversed-phase column and fluorometric detection and evaluation. The assay is rapid (17 min) and sensitive to as little as 1 mumol/L. The mean value for 27 cerebrospinal fluid sam...
journal_title：Clinical chemistry
pub_type： 杂志文章
doi：
更新日期：1979-08-01 00:00:00
abstract：:Alanine aminotransferase activity in serum increases significantly when serum is incubated with pyridoxal phosphate. The increase depends on the L-alanine concentration in the final assay mixture, being greatest at 800 mmol/liter. Preincubation of 22 normal sera, in a 10:1 ratio with an 8.09 mmol/liter pyridoxal phosp...
journal_title：Clinical chemistry
pub_type： 杂志文章
doi：
更新日期：1977-02-01 00:00:00
abstract：BACKGROUND:Cerebrospinal fluid (CSF) tau is a common biomarker for Alzheimer disease (AD). Measurements of tau have historically been performed using immunoassays. Given the molecular diversity of tau in CSF, the selectivity of these immunoassays has often been questioned. Therefore, we aimed to develop an analytically...
journal_title：Clinical chemistry
pub_type： 杂志文章
doi：10.1373/clinchem.2013.216515
更新日期：2014-04-01 00:00:00
abstract：BACKGROUND:Hepcidin-25 reduces iron absorption by binding to the intestinal iron transporter ferroportin and causing its degradation. Currently, little is known about the basal regulation of circulating hepcidin-25. In addition, although erythropoietin administration has been reported to decrease the circulating hepcid...
journal_title：Clinical chemistry
pub_type： 杂志文章
doi：10.1373/clinchem.2012.186866
更新日期：2012-08-01 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
