Abstract:
:We describe a rapid and simple insulin RIA in which proinsulin and conversion intermediates do not interfere. Three monoclonal antibodies (S1, S2, and S53) were selected for their specificity (directed, respectively, against the B10 region, the junction between A chain and C-peptide, and the junction between B chain and C-peptide), their affinity constant (approximately 10(10) L/mol), and their interactive properties in mixture. S2 and S53 were able to bind simultaneously to the same proinsulin molecule, whereas neither could bind simultaneously with S1. Preincubation of serum samples with an excess of S2 resulted in capture of proinsulin and conversion intermediates modified at the junction between B chain and C-peptide into immune complexes that no longer reacted with S1. Similarly, preincubation with S53 prevented proinsulin and conversion intermediates modified at the junction between A chain and C-peptide from reacting with S1. Preincubation with an excess of both S2 and S53 left insulin as the sole reactant with S1. Thus, separation of insulin precursors from insulin by mutually exclusive antibodies is feasible, and on the basis of this new principle, a highly specific RIA for insulin was designed. The detection limit was 11 pmol/L, and the inter- and intraassay coefficients of variation were 11% and 5%, respectively. The potential of the assay for use in clinical studies was verified by application to serum samples from control subjects and patients with diabetes or insulinoma.
journal_name
Clin Chemjournal_title
Clinical chemistryauthors
Deberg M,Houssa P,Frank BH,Sodoyez-Goffaux F,Sodoyez JCsubject
Has Abstractpub_date
1998-07-01 00:00:00pages
1504-13issue
7eissn
0009-9147issn
1530-8561journal_volume
44pub_type
杂志文章abstract::We report here the normal range of serum alkaline phophatase activity as measured by the method proposed by Hausamen et al. [Clin. Chim. Acta 15, 241 (1967)] with a much larger sample size than used in previous investigations. In the statistical analysis the sample population is subdivided by sex and age, two variable...
journal_title:Clinical chemistry
pub_type: 杂志文章
doi:
更新日期:1977-09-01 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::Determination of the ratio of testosterone to epitestosterone (T/E) in urine is used to detect testosterone administration in athletes, with a ratio > 6 considered as evidence of an offense. We show that administration of ketoconazole, which inhibits testosterone biosynthesis, may be useful for differentiating between...
journal_title:Clinical chemistry
pub_type: 杂志文章
doi:
更新日期:1993-09-01 00:00:00
abstract::We measured total and dialyzable calcium concentrations in consecutive sera submitted for routine lithium analysis. Of 98 samples from 61 different individuals, six (6.1%) total calcium results and 32 (33%) dialyzable calcium results were above the respective reference intervals. By comparison, when both total and dia...
journal_title:Clinical chemistry
pub_type: 杂志文章
doi:
更新日期:1979-10-01 00:00:00
abstract:BACKGROUND:Quantitative, miniaturized nucleic acid assays and immunoassays can be developed with single microparticles, microfluorometric detection, and intrinsically fluorescent lanthanide chelates in a multiple assay format to decrease reagent consumption, cost, and assay time. We used recombinant Fab fragments to ca...
journal_title:Clinical chemistry
pub_type: 杂志文章
doi:
更新日期:2000-11-01 00:00:00
abstract:BACKGROUND:Atherosclerosis is a systemic disease with focal rupture of vulnerable plaque responsible for major clinical events. Several population-based studies indicate an association between lipoprotein-associated phospholipase A2 (Lp-PLA2) and cardiovascular events. Lp-PLA2 is emerging as a biomarker that may be a p...
journal_title:Clinical chemistry
pub_type: 杂志文章,评审
doi:10.1373/clinchem.2006.070672
更新日期:2006-09-01 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 reported (Clin Chem 29: 42-44, 1983) that prestaining with Remazol Brilliant Blue permits direct visualization of serum components on disc electrophoresis, and apparently purifies the proteins well. Here we have cut out the bands corresponding to the prestained albumin and transferrin after disc electrophoresi...
journal_title:Clinical chemistry
pub_type: 杂志文章
doi:
更新日期:1984-07-01 00:00:00
abstract::For many lysosomal storage disorders, presymptomatic detection, before the onset of irreversible pathology, will greatly improve the efficacy of current and proposed therapies. In the absence of a family history, presymptomatic detection can be achieved only by a comprehensive newborn screening program. Recently we re...
journal_title:Clinical chemistry
pub_type: 杂志文章
doi:
更新日期:1998-10-01 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::I describe a gas-chromatographic procedure involving a nitrogen detector for "free" (or "unbound") phenytoin in the concentration range 0.2-4.0 mg/L in ultrafiltrates of plasma. The CV (n = 10) for the assay was 2.9% for a 0.49 mg/L concentration, 1.5% for 2.02 mg/L. The sensitivity was 0.05 mg/L. The ultrafiltration ...
journal_title:Clinical chemistry
pub_type: 杂志文章
doi:
更新日期:1981-03-01 00:00:00
abstract:BACKGROUND:In 2008, the US Food and Drug Administration (FDA) issued a Guidance for Industry statement formally recognizing (during drug development) the conjoined nature of type 2 diabetes (T2D) and cardiovascular disease (CVD), which has precipitated an urgent need for panels of markers (and means of analysis) that a...
journal_title:Clinical chemistry
pub_type: 杂志文章
doi:10.1373/clinchem.2010.156976
更新日期:2011-05-01 00:00:00
abstract::We report the first solid-phase radioimmunoassay for triiodothyronine with use of antibody-coated tubes, which is designed specifically for the fully automated radioimmunoassay instrument, Micromedic Systems' "Concept 4 Automatic Radioassay." Antisera to triiodothyropropionic acid/bovine serum albumin were raised in r...
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:Recent studies have suggested that glial fibrillary acidic protein (GFAP) serum concentrations distinguish between intracerebral hemorrhage (ICH) and ischemic stroke (IS) shortly after symptom onset. In this prospective multicenter trial we validated GFAP in an independent patient cohort and assessed the qua...
journal_title:Clinical chemistry
pub_type: 杂志文章
doi:10.1373/clinchem.2016.263335
更新日期:2017-01-01 00:00:00
abstract::We measured the free amino acids in plasma of 58 patients with HIV infection and in six persons in the risk group. The HIV+ patients had significantly increased concentrations of arginine, phenylalanine, and glutamate in comparison with both age- and sex-matched controls and the members of the risk group. Glutamate co...
journal_title:Clinical chemistry
pub_type: 杂志文章
doi:
更新日期:1988-09-01 00:00:00
abstract::This highly sensitive method for determination of beta 2-microglobulin (beta 2-m) in human urine or serum is based on direct agglutination by beta 2-m of latex particles on which an antibody against beta 2-m is adsorbed. The agglutination is quantified by counting the remaining unagglutinated particles, or by turbidim...
journal_title:Clinical chemistry
pub_type: 杂志文章
doi:
更新日期:1981-06-01 00:00:00
abstract::We measured immunoglobulins in the sera of 33 patients on days 1, 3, 6, 10, and 17 and three to four weeks after surgical operations (mostly hysterectomy or appendectomy) or (six patients) after spinal injury. In the absence of infection or blood transfusion, IgG usually decreased slightly and transiently after hyster...
journal_title:Clinical chemistry
pub_type: 杂志文章
doi:
更新日期:1975-05-01 00:00:00
abstract::We evaluated five quantitative, commercially available radioimmunoassay methods (Beta-Tec, BIO-RIA, Cambridge Nuclear, Mallinckrodt, and Serono) for rapid determination of the beta-subunit of human choriogonadotropin in serum or plasma. Only three of the kits (Beta-Tec, Mallinckrodt, and Serono) were found suitable fo...
journal_title:Clinical chemistry
pub_type: 杂志文章
doi:
更新日期:1980-12-01 00:00:00
abstract::We compared the performance of three methods for quantifying high-density lipoprotein cholesterol (HDL-C) with the Reference Method for HDL-C, using samples with a wide range of triglyceride (TG) concentrations (290-18000 mg/L). All three comparison assays-- utilizing a magnetic dextran sulfate precipitating reagent, ...
journal_title:Clinical chemistry
pub_type: 杂志文章
doi:
更新日期:1996-05-01 00:00:00
abstract::We describe a novel radioimmunoassay procedure for the direct estimation of aldosterone in unextracted plasma and serum samples, in which interfering binding proteins are digested by Proteinase K (Tritirachium alkaline proteinase, EC 3.4.21.14), a powerful proteolytic enzyme. Heating at 75 degrees C for 15 min inactiv...
journal_title:Clinical chemistry
pub_type: 杂志文章
doi:
更新日期:1981-12-01 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 new method for quantitatively measuring substances of clinical interest by high-performance liquid affinity chromatography (HPLAC). As a model system we selected analysis for transferrin in human serum with immobilized antibodies in a high-performance liquid chromatographic system. SelectiSpher-10 Activa...
journal_title:Clinical chemistry
pub_type: 杂志文章
doi:
更新日期:1988-10-01 00:00:00
abstract:BACKGROUND:Aberrant DNA hypermethylation of CpG islands occurs frequently throughout the genome in human colorectal cancer (CRC). A genome-wide DNA hypermethylation analysis technique using circulating cell-free DNA (cfDNA) is attractive for the noninvasive early detection of CRC and discrimination between CRC and othe...
journal_title:Clinical chemistry
pub_type: 杂志文章
doi:10.1373/clinchem.2019.301804
更新日期:2019-07-01 00:00:00
abstract:BACKGROUND:FMR1 full mutations (FMs) (CGG expansion >200) in males mosaic for a normal (<45 CGG) or gray-zone (GZ) (45-54 CGG) allele can be missed with the standard 2-step fragile X syndrome (FXS) testing protocols, largely because the first-line PCR tests showing a normal or GZ allele are not reflexed to the second-l...
journal_title:Clinical chemistry
pub_type: 杂志文章
doi:10.1373/clinchem.2015.244681
更新日期:2016-02-01 00:00:00
abstract::Monoclonal antibodies were raised against neuron-specific enolase, gamma gamma-enolase, and used in an immunoradiometric assay (IRMA), with mono-disperse magnetizable particles as the solid phase. The assay's sensitivity was 0.4 microgram/L and the interassay coefficient of variation was less than 5% in the working ra...
journal_title:Clinical chemistry
pub_type: 杂志文章
doi:
更新日期:1989-10-01 00:00:00
abstract::Binary-system capillary electrophoresis (CE) with head-column field-amplified sample stacking permits determination of amiodarone and desethylamiodarone in 20-microL serum samples. The assay is characterized by a detection limit for both compounds of 80 nmol/L and by excellent linear response over the recommended ther...
journal_title:Clinical chemistry
pub_type: 杂志文章
doi:
更新日期:1996-11-01 00:00:00
abstract::We evaluated superoxide dismutase (EC 1.15.1.1) and glutathione peroxidase (EC 1.11.1.9) activities in the erythrocytes of lead-exposed and nonexposed workers from distinct industries localized in the State of São Paulo, Brazil. Concentrations of either lead or protoporphyrin IX, or both, in blood were used to indicat...
journal_title:Clinical chemistry
pub_type: 杂志文章
doi:
更新日期:1985-10-01 00:00:00
abstract:BACKGROUND:Cyclosporin A (CsA) is commonly measured by immunoassay techniques that have a limited analytical range. The consequence of this is that low CsA concentrations that may be clinically significant are difficult to measure and that high concentrations require sample dilution, which introduces error and increase...
journal_title:Clinical chemistry
pub_type: 杂志文章
doi:
更新日期:2002-01-01 00:00:00
abstract::We compared results obtained from two parathyrin (parathyroid hormone) assays with differing specificities, using sera from 172 normal donors and from 98 patients with disorders of calcium regulation. Intact parathyrin was measured in both assays; the C-parathyrin assay also measured the 53-84 amino acid C-terminal ho...
journal_title:Clinical chemistry
pub_type: 杂志文章
doi:
更新日期:1980-11-01 00:00:00