Abstract:
:We developed a radioimmunoassay with a gamma-emitting radioligand to measure androstenedione in human serum and in dried blood-spot samples from newborns. Antisera were raised in rabbits against androstenedione linked to bovine serum albumin at positions 3, 6, or 11 on the steroid nucleus. Radioligands were prepared by linking [125I]iodohistamine at positions 3, 6, or 11. Linkages were through either carboxymethyloxime or hemisuccinate bridges. All label and antibody combinations were examined, and the most sensitive and specific combination (antiserum raised against androstenedione-3-carboxymethyloxime-bovine serum albumin with an androstenedione-carboxymethyloxime-[125I]iodohistamine label) was selected for full evaluation. We report the performance of these selected reagents in an immunoassay for androstenedione in both serum and dried blood-spot samples from neonates. We measured concentrations of androstenedione in serum under normal and pathological conditions such as congenital adrenal hyperplasia and polycystic ovarian disease. Diurnal variation in normal men was observed. Androstenedione was measured in blood spots from neonates born at term or prematurely, with respiratory distress syndrome, or with congenital adrenal hyperplasia.
journal_name
Clin Chemjournal_title
Clinical chemistryauthors
Thomson S,Wallace AM,Cook Bsubject
Has Abstractpub_date
1989-08-01 00:00:00pages
1706-12issue
8eissn
0009-9147issn
1530-8561journal_volume
35pub_type
杂志文章abstract:BACKGROUND:The bleeding time (BT) test predicts a higher bleeding complication rate in populations at risk for inherited or acquired platelet dysfunction, but it is of limited assistance in evaluating individual patients. There are no reports of clinical outcomes after discontinuation of the BT test. METHODS:Interview...
journal_title:Clinical chemistry
pub_type: 杂志文章
doi:
更新日期:2001-01-01 00:00:00
abstract::A quantitative "high-performance" liquid-chromatographic method is described for determining porphyrins in human urine. Porphyrinogens in urine are first converted to the corresponding porphyrins by oxidation with iodine. Uroporphyrin, hepatacarboxylic acid porphyrin, hexacarboxylic acid porphyrin, pentacarboxylic aci...
journal_title:Clinical chemistry
pub_type: 杂志文章
doi:
更新日期:1989-08-01 00:00:00
abstract:BACKGROUND:Patients differ in responses to warfarin, which is commonly prescribed to treat thromboembolic events. Genetic variations in the cytochrome P450, family 2, subfamily C, polypeptide 9 (CYP2C9), vitamin K epoxide reductase complex, subunit 1 (VKORC1), and gamma-glutamyl carboxylase (GGCX) genes have been shown...
journal_title:Clinical chemistry
pub_type: 杂志文章
doi:10.1373/clinchem.2008.118497
更新日期:2009-04-01 00:00:00
abstract:BACKGROUND:Fecal calprotectin (FC) has been proposed as a marker of inflammatory bowel disease (IBD), but few studies have evaluated its usefulness in patients with chronic diarrhea of various causes. We evaluated the diagnostic accuracy of a FC assay in identifying "organic" causes of chronic diarrhea in consecutive a...
journal_title:Clinical chemistry
pub_type: 杂志文章
doi:10.1373/49.6.861
更新日期:2003-06-01 00:00:00
abstract:BACKGROUND:Extracellular matrix alterations are important elements in the arterial changes seen in diabetes, being associated with increased vascular stiffness and the development of cardiovascular diseases. However, no biomarkers for diabetes-related arterial changes have been defined. METHODS:Mammary artery specimen...
journal_title:Clinical chemistry
pub_type: 杂志文章
doi:10.1373/clinchem.2011.162966
更新日期:2011-11-01 00:00:00
abstract::Red blood cell (RBC) replacement solutions are being developed as alternatives to allogeneic RBC use in blood transfusions in the treatment of massive trauma, to achieve hemodynamic stability during elective surgery, and to increase oxygen-carrying capacity in anemia. Hemoglobin-based oxygen carrier (HBOC)-201 (Biopur...
journal_title:Clinical chemistry
pub_type: 杂志文章
doi:
更新日期:1997-09-01 00:00:00
abstract::We evaluated a new discrete analyzer, the Hitachi 705. The instrument can process sequentially as many as 19 different enzymes or other analytes, with a throughput of 180 tests per hour. We evaluated the spectrophotometer, the sample and reagent probes, and the performance for 11 assays: creatine kinase, aspartate ami...
journal_title:Clinical chemistry
pub_type: 杂志文章
doi:
更新日期:1983-04-01 00:00:00
abstract:BACKGROUND:Consideration of circulating biomarkers for risk stratification in heart failure (HF) is recommended, but the influence of atrial fibrillation (AF) on prognostic performance of many markers is unclear. We investigated the influence of AF on the prognostic performance of circulating biomarkers in HF. METHODS...
journal_title:Clinical chemistry
pub_type: 杂志文章
doi:10.1093/clinchem/hvaa287
更新日期:2021-01-08 00:00:00
abstract::Discrepancies among different methods for assaying human growth hormone have been described in various studies. The two major sources of discordant results are the heterogeneity of the antibodies and the different standardization bases used by the assay manufacturers. We propose standardizing assays with 22-kDa biosyn...
journal_title:Clinical chemistry
pub_type: 杂志文章
doi:
更新日期:1992-10-01 00:00:00
abstract::A highly sensitive sandwich-type chemiluminescence enzyme immunoassay for plasma endothelin-I (ET-1), involving no extraction steps, has been developed. Two populations of polyclonal antibodies were used in the present study: One is specific to the C-terminus of the endothelin family of peptides; the other, a Fab' fra...
journal_title:Clinical chemistry
pub_type: 杂志文章
doi:
更新日期:1996-08-01 00:00:00
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journal_title:Clinical chemistry
pub_type: 杂志文章
doi:
更新日期:1994-03-01 00:00:00
abstract::In this simple and low-cost radioimmunoassay (RIA) procedure for thyroxin (T4), ethacridine (6,9-diamino-2-ethoxyacridine lactate; Rivanol) is used to separate antibody-bound ligand and free ligand. This acridine dye precipitates free T4 not bound to antibody. At pH 8.6, it precipitates more than 90% of 125I-labeled T...
journal_title:Clinical chemistry
pub_type: 杂志文章
doi:
更新日期:1983-11-01 00:00:00
abstract::In the Prospective Cardiovascular Münster (PROCAM) study, serum lipoprotein(a) [Lp(a)] and its relationship to pro- and anticoagulatory as well as fibrinolytic indices were determined in a large group of employees: 864 men (m) and 373 women (f), ages 16-65 years. Univariate statistical analysis showed Lp(a) concentrat...
journal_title:Clinical chemistry
pub_type: 杂志文章
doi:
更新日期:1991-11-01 00:00:00
abstract::We describe a fixed-time, enzymatic, reaction-rate procedure for determining plasma ammonia with a centrifugal analyzer (Rotochem IIA/36; American Instrument Co., silver Spring, MD 20910), with NADPH as cofactor. The reaction is based on that of da Fonseca-Wollheim's modification [J. Clin. Chem. Clin. Biochem. 11, 421...
journal_title:Clinical chemistry
pub_type: 杂志文章
doi:
更新日期:1979-04-01 00:00:00
abstract::Controversy regarding the presence of a circadian rhythm in unconjugated estriol in serum during pregnancy led us to study the possibility that the observed rhythms actually are the result of partitioning of estriol into serum lipids when these increase postprandially. Addition of triglycerides to purified estriol sta...
journal_title:Clinical chemistry
pub_type: 杂志文章
doi:
更新日期:1981-02-01 00:00:00
abstract::We compared three current methods (immunoinhibition, "Isomune-CK" immunoprecipitation, and the Tandem-E CKMB II immunoenzymometric assay) for determination of creatine kinase (CK; EC 2.7.3.2) isoenzyme MB in serum. Although results inter-correlated well, the immunoinhibition assay gave higher activity values. Atypical...
journal_title:Clinical chemistry
pub_type: 杂志文章
doi:
更新日期:1990-01-01 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:BACKGROUND:Several compounds in the choline oxidation pathway are associated with insulin resistance and prevalent diabetes; however, prospective data are scarce.We explored the relationships between systemic and urinary choline-related metabolites and incident type 2 diabetes in an observational prospective study amon...
journal_title:Clinical chemistry
pub_type: 杂志文章
doi:10.1373/clinchem.2015.250761
更新日期:2016-05-01 00:00:00
abstract::We have developed two methods for determining serum concentrations of felbamate, a new anticonvulsant drug. The first method is based on protein precipitation with acetonitrile, followed by HPLC. The between-run CV for this method is 5.7% (mean 55 mg/L), and the linearity extends from 5 to 175 mg/L. Results by this me...
journal_title:Clinical chemistry
pub_type: 杂志文章
doi:
更新日期:1994-10-01 00:00:00
abstract::Determination of the concentration of erythrocyte folate by means of competitive protein binding assay critically depends on the extraction procedure applied. Results will be influenced by variable factors such as the in vitro age of the blood samples, the degree of hemolysis, the presence of ascorbic acid, and the pH...
journal_title:Clinical chemistry
pub_type: 杂志文章
doi:
更新日期:1976-07-01 00:00:00
abstract::Hemostasis is initiated by injury to the vascular wall, leading to the deposition of platelets adhering to components of the subendothelium. Platelet adhesion requires the presence of von Willebrand factor and platelet receptors (IIb/IIIa and Ib/IX). Additional platelets are recruited to the site of injury by release ...
journal_title:Clinical chemistry
pub_type: 杂志文章,评审
doi:
更新日期:2000-08-01 00:00:00
abstract::A highly sensitive two-site enzyme immunoassay (Capcellia) was developed to determine the concentration of CD4 and CD8 molecules expressed on the surface of human T lymphocytes. This assay, performed in one step (20 min), involves the specific immunocapture of T lymphocytes and reaction of the CD4 or CD8 molecules wit...
journal_title:Clinical chemistry
pub_type: 杂志文章
doi:
更新日期:1994-01-01 00:00:00
abstract::Measurement of serum ascorbate may be useful in long-term population studies because of the possible influence of ascorbate on numerous physiological factors. We describe an automated method for determining ascorbate in serum and urine by using the reduction of ferric iron by ascorbate and the formation of a color bet...
journal_title:Clinical chemistry
pub_type: 杂志文章
doi:
更新日期:1975-09-01 00:00:00
abstract::A rapid technique (5-10 min) has been developed for fractionating nucleotides from base and nucleoside contaminants in acid extracts of cells, by adsorption to silica gels. Silica gels (1-mL bed volume) were washed with 5 mL of water then with 5 mL of acetonitrile/water (90/10 by vol). After applying 3-mL samples, adj...
journal_title:Clinical chemistry
pub_type: 杂志文章
doi:
更新日期:1980-09-01 00:00:00
abstract::The most popular pretreatment method of plasma samples for the measurement of ascorbate (AsA) and dehydroascorbate (DHA) has been an acidic deproteinization via metaphosphoric acid or trichloroacetic acid. In general, DHA is absent in plasma samples prepared from human blood in a conventional manner. However, when the...
journal_title:Clinical chemistry
pub_type: 杂志文章
doi:
更新日期:1998-04-01 00:00:00
abstract::We report the kinetics of the reactions of unconjugated bilirubin and conjugated bilirubin with p-diazobenzene sulfonic acid in aqueous media. Our studies confirm that each reaction proceeds in two steps and that the second step is catalyzed by sulfanilic acid. In the presence of an excess of p-diazobenzenesulfonic ac...
journal_title:Clinical chemistry
pub_type: 杂志文章
doi:
更新日期:1978-10-01 00:00:00
abstract:BACKGROUND:Standardization of hemoglobin (Hb)A(1c) measurements is a process of considerable interest for quality assurance in diabetes management. To contribute to continuous quality improvement and fulfillment of the requirements for reference measurement procedures according to the standards of the International Org...
journal_title:Clinical chemistry
pub_type: 杂志文章
doi:10.1373/clinchem.2009.139477
更新日期:2010-05-01 00:00:00
abstract::This case demonstrates the importance of monitoring theophylline concentrations in serum during therapy with this drug. The commonly used body-weight-derived guidelines for therapeutic dose are not adequate and do not preclude the necessity for such monitoring. The ultraviolet spectrophotometric methods available for ...
journal_title:Clinical chemistry
pub_type: 杂志文章
doi:
更新日期:1978-09-01 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::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