Abstract:
:We measured total serum bile acids on a fluorescence-light-scattering micro centrifugal analyzer by the direct enzymatic method with 3 alpha-hydroxysteroid dehydrogenase (EC 1.1.1.50) and with resazurin as a fluorogenic electron acceptor. We found that serum protein has an inhibitory effect on the measurement of bile acids, but this effect was eliminated by adding bovine serum albumin to the reaction mixture in a final protein concentration (12.2 g/L) that was high compared with that contributed by a normal serum specimen. The assay is a sensitive method that reaches equilibrium in 5 min. The method is microscale (5 microL of sample, 150 microL of working reagent), is easy to perform, and is accurate (analytical recovery = 104.1%) and precise (CV = 11.1 and 5.7% on specimens with bile acid concentrations of 7.6 and 35.4 mumol/L, respectively). Normal values are 1-12 and less than 9 mumol/L on nonfasting and fasting individuals, respectively. Pure 3 alpha-hydroxysteroid dehydrogenase must be used: we found several enzyme preparations that gave falsely high values for bile acid.
journal_name
Clin Chemjournal_title
Clinical chemistryauthors
Hanson NQ,Freier EFsubject
Has Abstractpub_date
1983-01-01 00:00:00pages
171-5issue
1eissn
0009-9147issn
1530-8561journal_volume
29pub_type
杂志文章abstract:BACKGROUND:Cardiac troponin T (cTnT) is the preferred biomarker for the diagnosis of acute myocardial infarction (AMI). It has been suggested that cTnT is present predominantly in fragmented forms in human serum following AMI. In this study, we have used a targeted mass spectrometry assay and epitope mapping using West...
journal_title:Clinical chemistry
pub_type: 杂志文章
doi:10.1373/clinchem.2016.261511
更新日期:2017-02-01 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::We compared measurements of apoprotein A-I (apoA-I) in plasma and in heparin-MnCl2 supernates analyzed by radial immunodiffusion. The apoA-I values were similar when the samples were fresh [n = 41, mean (SD), mg/L: plasma, 1393.4(349); heparin-MnCl2 supernates, 1364.9(332), p less than 0.01], but were greater than 8% ...
journal_title:Clinical chemistry
pub_type: 杂志文章
doi:
更新日期:1986-06-01 00:00:00
abstract::An optimized assay for alkaline phosphatase (EC 3.1.3.1) is reported. A discrete analyzer, the DuPont Automatic Clinical Analyzer (aca), was used for this study. The assay is based on results of response-surface experimental co-optimization techniques, and response is enhanced over the present aca assay. A key feature...
journal_title:Clinical chemistry
pub_type: 杂志文章
doi:
更新日期:1981-07-01 00:00:00
abstract::The Glucose-Controlled Insulin Infusion System (Biostator) is a modular, computerized, feedback control system for dynamic control of blood glucose concentrations in diabetics. This on-line glucose analyzer for use with whole blood utilizes a novel enzyme (glucose oxidase)-membrane configuration and an electrochemical...
journal_title:Clinical chemistry
pub_type: 杂志文章
doi:
更新日期:1978-08-01 00:00:00
abstract::In photometry, where both the product formed and one or several reactants absorb light at the same wavelength, the absorbance of the "blank" of the sample at the end of the reaction may be less than that measured at the beginning of the reaction, because of consumption of reactant(s). The blank correction factor for t...
journal_title:Clinical chemistry
pub_type: 杂志文章
doi:
更新日期:1985-03-01 00:00:00
abstract::We examined the changes in sensitivity and specificity that would occur with alterations in the sample-collection schedule and (or) cutoff criterion for the increase in hydrogen concentration in breath after administration of doses of lactose in the dietary range. In a breath-analysis test to classify individuals as l...
journal_title:Clinical chemistry
pub_type: 杂志文章
doi:
更新日期:1983-03-01 00:00:00
abstract::This highly sensitive method for determining retinol-binding protein in human serum and urine is based on a double-antibody "sandwich"-type enzyme-linked immunosorbent assay. The assayable concentration range is 0.8-48 micrograms/L, the detection limit 0.2 micrograms/L. Within-assay coefficients of variation for 10 de...
journal_title:Clinical chemistry
pub_type: 杂志文章
doi:
更新日期:1984-01-01 00:00:00
abstract::The manual Reference Method of the Centers for Disease Control for serum iron (CDC/RM/Fe) and a semiautomated adaptation of it were used to evaluate two working methods: one, a detergent solubilization procedure for the Roche Cobas-Bio analyzer, the other, the Kodak Ektachem 700 procedure, based on dry-film technology...
journal_title:Clinical chemistry
pub_type: 杂志文章
doi:
更新日期:1990-10-01 00:00:00
abstract:BACKGROUND:Our previously developed assay for detection of the factor V Leiden mutation (G1691A) based on a nucleic acid photo-cross-linking technology used two allele-specific capture probes and six fluorescein-modified signal-generating reporter probes. We wished to improve the sensitivity and performance of the meth...
journal_title:Clinical chemistry
pub_type: 杂志文章
doi:10.1373/clinchem.2003.023556
更新日期:2004-02-01 00:00:00
abstract::Measurement of alpha-fetoprotein concentration and acetylcholinesterase activity in amniotic fluid can be used to identify chromosomal defects as well as neural tube defects. In seven cases of trisomy 21 and one case of partial trisomy 3, alpha-fetoprotein concentrations were below the reference range but values for a...
journal_title:Clinical chemistry
pub_type: 杂志文章
doi:
更新日期:1985-04-01 00:00:00
abstract::We have developed and evaluated a new procedure for detecting trends in quality-control measurements and applied it to laboratory data. The method requires the use of sequential or "moving" slope estimates to identify trends. Formulae are derived to estimate the regression error for the moving slope directly from the ...
journal_title:Clinical chemistry
pub_type: 杂志文章
doi:
更新日期:1991-03-01 00:00:00
abstract::Four commercial products for urine glucose determination were evaluated and compared with a quantitative hexokinase procedure. We examined precision, sensitivity, and analytical recovery of glucose from glucose-supplemented urine samples and comparison of methods, using patients' samples. Only "Chemstrip uG" (Bio-Dyna...
journal_title:Clinical chemistry
pub_type: 杂志文章
doi:
更新日期:1982-10-01 00:00:00
abstract::In routine analysis for immunoglobulin light chains in pediatric diagnostics, the age-related reference intervals for serum kappa (kappa) and lambda (lambda) light chains were evaluated in 1543 healthy subjects (newborns to age 16 years, including 168 premature infants). Light-chain analysis was performed by rate neph...
journal_title:Clinical chemistry
pub_type: 杂志文章
doi:
更新日期:1992-04-01 00:00:00
abstract:BACKGROUND:D-2-Hydroxyglutaric aciduria (D-2-HGA), L-2-hydroxyglutaric aciduria (L-2-HGA), and the combined D/L-2-hydroxyglutaric aciduria (D/L-2-HGA) are poorly understood organic acidurias. To investigate the usefulness of cultured human skin fibroblasts for both diagnostic and research purposes, we measured disease-...
journal_title:Clinical chemistry
pub_type: 杂志文章
doi:10.1373/49.7.1133
更新日期:2003-07-01 00:00:00
abstract::We evaluated the density-gradient ultracentrifugation method in a swinging-bucket rotor (Anal Biochem 111, 149-157, 1981) in a slightly modified version for isolation and determination of high-density lipoprotein (HDL) subfractions. We prestained the serum with Coomassie Brilliant Blue R, which did not change the hydr...
journal_title:Clinical chemistry
pub_type: 杂志文章
doi:
更新日期:1983-04-01 00:00:00
abstract::We describe an enzymatic fluorometric method for determining glucose concentrations in blood samples by analysis on a semi-solid surface (silicone-rubber pads). The method is an adaptation of existing spectrophotometric procedures based on the sequential coupling reactions with glucose-6-phosphate dehydrogenase and NA...
journal_title:Clinical chemistry
pub_type: 杂志文章
doi:
更新日期:1975-11-01 00:00:00
abstract::Concentrations of free thyroxin (T4) and free triiodothyronine (T3) were measured in sera from pregnant women, in subjects with congenitally increased or decreased thyroxin-binding globulin (TBG), and in euthyroid controls. Measured free hormone concentrations were compared with calculated values for free hormone deri...
journal_title:Clinical chemistry
pub_type: 杂志文章
doi:
更新日期:1983-08-01 00:00:00
abstract:BACKGROUND:Prostate-specific antigen (PSA) occurs in serum both free and in complex with protease inhibitors. The complex with alpha1-antichymotrypsin (ACT) is the major form in serum, and the proportion of PSA-ACT is higher in prostate cancer (PCa) than in benign prostatic hyperplasia (BPH). PSA also forms a complex w...
journal_title:Clinical chemistry
pub_type: 临床试验,杂志文章
doi:
更新日期:1999-06-01 00:00:00
abstract::Clinicians confront the classical problem of decision making under uncertainty, but a universal procedure by which they deal with this situation, both in diagnosis and therapy, can be defined. This consists in the choice of a specific course of action from available alternatives so as to reduce uncertainty. Formal ana...
journal_title:Clinical chemistry
pub_type: 杂志文章,评审
doi:
更新日期:1995-08-01 00:00:00
abstract::In the diagnosis of chronic (as opposed to acute) liver diseases, combinations of indicators are needed to improve specificity. Alanine aminopeptidase (AAP; microsomal aminopeptidase, EC 3.4.11.2) activity in serum reportedly is a very sensitive indicator of intrahepatic cholestasis and biliary obstruction; it is also...
journal_title:Clinical chemistry
pub_type: 杂志文章
doi:
更新日期:1987-03-01 00:00:00
abstract::Physiologic systems have substantial reserves in younger individuals. The process of aging and intercurrent pathologic processes gradually eliminate these reserves. Changes in endocrine systems, including menopause in women, androgen deficiency in men, loss of skeletal mass, decrease in growth hormone serum concentrat...
journal_title:Clinical chemistry
pub_type: 杂志文章,评审
doi:
更新日期:1999-08-01 00:00:00
abstract:BACKGROUND:To address the continuing need for the standardization of clinical human cardiac troponin I (cTnI) assays, NIST, with the assistance of the AACC/IFCC Cardiac Troponin I Standardization Committee, has developed a new certified reference material, Standard Reference Material (SRM) 2921: Human Cardiac Troponin ...
journal_title:Clinical chemistry
pub_type: 杂志文章
doi:10.1373/clinchem.2005.051359
更新日期:2006-02-01 00:00:00
abstract::We studied the effects of some chelators on creatine kinase activity. Creatine kinase is competitively inhibited by endogenous polyvalent cations (e.g., calcium, Ki = 4.5 mmol/L); this can be reversed by adding chelators to the reagent, resulting in a mean increase in activity of 1.14-fold at 25 degrees C and 1.18-fol...
journal_title:Clinical chemistry
pub_type: 杂志文章
doi:
更新日期:1979-03-01 00:00:00
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::Purified arylsulfatase A (EC 3.1.6.1) from human urine was radioiodinated under conditions that caused no significant loss of antigenic activity. We used this labeled arylsulfatase A (specific radioactivity 4-7.5 Ci/g) together with nonlabeled enzyme and rabbit antiserum produced against homogeneous enzyme to develop ...
journal_title:Clinical chemistry
pub_type: 杂志文章
doi:
更新日期:1985-03-01 00:00:00
abstract::This ultrafiltration technique allows determination of free drug in 50 microL of serum. We ultrafiltered sera containing the following drugs--valproic acid (and its major metabolites), phenobarbital, diazepam, indomethacin, phenytoin, furosemide, and chloramphenicol--using both the commercially available micropartitio...
journal_title:Clinical chemistry
pub_type: 杂志文章
doi:
更新日期:1984-06-01 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::In this method for separating glycosylated from nonglycosylated hemoglobin in blood by electrophoresis on cellulose acetate membranes, we exploit the affinity of low-molecular-mass dextran sulfate for the nonglycosylated fraction, which increases the mobility of the latter relative to that of glycosylated hemoglobin. ...
journal_title:Clinical chemistry
pub_type: 杂志文章
doi:
更新日期:1983-02-01 00:00:00
abstract::We describe a sensitive method for the determination of vanadium in biological substances by atomic absorption spectroscopy. By using background correction and pyrolytically coated graphite tubes with flameless apparatus, this vanadium assay has a sensitivity of 65 pg and a detection limit of 30 pg, approximately sixf...
journal_title:Clinical chemistry
pub_type: 杂志文章
doi:
更新日期:1982-01-01 00:00:00