Abstract:
:The difference in absorbance (delta A) between equimolar acid and alkaline solutions of methyl red, at a wavelength near the isosbestic point of the indicator, is reproducible. Furthermore, this delta A is sensitive to changes in the wavelength calibration of the instrument used to make the measurement. The delta A of methyl red can be used to monitor wavelength accuracy in both manual and automated spectrophotometric instruments. Although this measurement does not establish wavelength calibration, it is useful for monitoring the wavelength accuracy of previously calibrated, automated spectrophotometers that do not easily lend themselves to calibration checks by conventional techniques.
journal_name
Clin Chemjournal_title
Clinical chemistryauthors
Korzun WJ,Miller WGsubject
Has Abstractpub_date
1986-01-01 00:00:00pages
162-5issue
1 Pt 1eissn
0009-9147issn
1530-8561journal_volume
32pub_type
杂志文章abstract:BACKGROUND:Testing for troponin has important clinical value for patients who present with typical symptoms of acute coronary syndromes (ACS) such as chest pain (CP). Much less is known about the value of troponin testing for patients who present with other symptoms of ACS (anginal equivalent symptoms). METHODS:The ut...
journal_title:Clinical chemistry
pub_type: 杂志文章
doi:10.1373/clinchem.2003.016311
更新日期:2004-01-01 00:00:00
abstract::We evaluated the enzymic mechanism by which 3-keto butylidene-beta-2-chloro-4-nitrophenyl maltopentaoside (3KB-G5-CNP) serves as a substrate for serum pancreatic (p-) and salivary (s-) amylases. In aliquots of the reaction mixture, three kinds of beta-2-chloro-4-nitrophenyl oligosaccharides (glucose, maltoside, and ma...
journal_title:Clinical chemistry
pub_type: 杂志文章
doi:
更新日期:1991-08-01 00:00:00
abstract::Sensitive and specific radioimmunoassays of metanephrine and normetanephrine were developed by use of 125I-labeled synephrine and specific metanephrine antibody, and 125I-labeled octopamine and specific normetanephrine antibody. Specific antibody for both metanephrine and normetanephrine was raised in rabbits by immun...
journal_title:Clinical chemistry
pub_type: 杂志文章
doi:
更新日期:1986-10-01 00:00:00
abstract::We have improved the protocol for RNA quantification by using RNase protection. Instead of precipitation and extraction with phenol and chloroform, we use a faster and more reliable precipitation based on guanidinium thiocyanate (GdSCN). The internal standard is produced by in vitro transcription of a DNA template con...
journal_title:Clinical chemistry
pub_type: 杂志文章
doi:
更新日期:1995-11-01 00:00:00
abstract::We report microchromatographic measurement of fetal hemoglobin (HbF) proportions in a 36-year-old African-American multigravida woman. At 34 weeks she delivered a 630-g male infant who subsequently did well. Hemoglobin electrophoresis of the hemolysate revealed nearly 100% HbF without HbA, an extremely unusual natural...
journal_title:Clinical chemistry
pub_type: 杂志文章
doi:
更新日期:1992-11-01 00:00:00
abstract::We studied several risk factors in relation to parental cardiovascular heart disease: total cholesterol, triglycerides, high-density lipoprotein (HDL) cholesterol, low-density lipoprotein (LDL) cholesterol, apolipoprotein (apo) A-I, apo B, and lipoprotein(a) [Lp(a)] were determined in 322 serum samples (43 from subjec...
journal_title:Clinical chemistry
pub_type: 杂志文章
doi:
更新日期:1993-03-01 00:00:00
abstract::We report the adaptation of four radioassays to the prototype of an automated radioimmunoassay system ("Centria," Union Carbide). The system consists of three integrated modules: (a) an automated pipettor, which dispenses samples and reagents; (b) the key module, an incubator/separator, in which centrifugal force is u...
journal_title:Clinical chemistry
pub_type: 杂志文章
doi:
更新日期:1975-08-01 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:BACKGROUND:Noninvasive prenatal testing (NIPT) uses cell-free DNA (cfDNA) as an analyte to detect copy-number alterations in the fetal genome. Because maternal and fetal cfDNA contributions are comingled, changes in the maternal genome can manifest as abnormal NIPT results. Circulating tumor DNA (ctDNA) present in case...
journal_title:Clinical chemistry
pub_type: 杂志文章
doi:10.1373/clinchem.2017.277517
更新日期:2018-02-01 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::We describe an improved enzymatic ultraviolet absorbance method for assaying creatinine in serum, plasma, and urine. Creatinine is hydrolyzed by creatinine iminohydrolase (EC 3.5.4.21) to ammonia and N-methylhydantoin. The ammonia produced combines with 2-oxoglutarate and NADPH in the presence of glutamate dehydrogena...
journal_title:Clinical chemistry
pub_type: 杂志文章
doi:
更新日期:1994-01-01 00:00:00
abstract::We determined estrogen receptor protein and carcinoembryonic antigen in cytosols prepared from 189 human breast carcinoma tissues, 85 benign or normal breast biopsies, and 101 tissue specimens metastatic from breast carcinoma. Carcinoembryonic antigen was observed in 70% of the primary carcinomatous tissues, 15% of th...
journal_title:Clinical chemistry
pub_type: 杂志文章
doi:
更新日期:1976-08-01 00:00:00
abstract:BACKGROUND:Although minimum regulatory standards exist for determining QC testing frequency, decisions regarding when and how to run QC samples are not standardized. Most QC testing strategies test control samples at fixed time intervals, often placing the samples in the same position on an instrument during subsequent...
journal_title:Clinical chemistry
pub_type: 杂志文章
doi:10.1373/clinchem.2006.083311
更新日期:2007-04-01 00:00:00
abstract::We describe the development of a stable reference material for prostatic acid phosphatase, derived from human prostatic tissue and human seminal fluid. The enzyme was purified by an L-tartramic acid affinity-chromatography technique. Two-dimensional electrophoresis revealed essentially no contaminating proteins, and s...
journal_title:Clinical chemistry
pub_type: 杂志文章
doi:
更新日期:1984-08-01 00:00:00
abstract::We present evidence for the utility of an improved assay for the activity of lactate dehydrogenase (EC 1.1.1.27) isoenzymes 1 and 2 in serum, involving inhibition of the H-subunit of LD by pyruvate at pH 7.1. Results correlate well with the LD-1/total LD ratio as evaluated by immunological assay and, as an index to in...
journal_title:Clinical chemistry
pub_type: 杂志文章
doi:
更新日期:1986-05-01 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: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::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::Quantification of ethanol by a radiative energy attenuation (REA) technique was evaluated and compared with results by gas-liquid chromatography (GLC) and by the Du Pont aca. Within-assay CVs were less than 5.5%. Between-assay CVs ranged from 1.9% to 6.0% for serum and blood controls at concentrations of 0.5, 1.0, and...
journal_title:Clinical chemistry
pub_type: 杂志文章
doi:
更新日期:1984-11-01 00:00:00
abstract::Antiserum performance in a nephelometric system can be characterized by parameters derived from measuring reaction rates. The characterization process is derived from a series of dose-response curves (elicited nephelometric response vs antigen concentration) generated from various dilutions of the antiserum being test...
journal_title:Clinical chemistry
pub_type: 杂志文章
doi:
更新日期:1981-11-01 00:00:00
abstract::Applying the principles of chemometrics can lead to development of a powerful, simple, comprehensive system for characterizing measurement reliability of analytical processes. The system described here consists of a format for specifications, definitions, and decision rules for evaluating and comparing analytical proc...
journal_title:Clinical chemistry
pub_type: 杂志文章
doi:
更新日期:1988-12-01 00:00:00
abstract::We compared a stabilized-temperature L'vov platform furnace containing an end-heated graphite atomizer (HGA) and transverse Zeeman background-correction system with a side-heated furnace system (transversely heated graphite atomizer; THGA) containing a longitudinal Zeeman background-correction system for the determina...
journal_title:Clinical chemistry
pub_type: 杂志文章
doi:
更新日期:1994-03-01 00:00:00
abstract:BACKGROUND:We previously reported a family in which the propositus and both her father and paternal grandmother had high serum aminopeptidase N (CD13; EC 3.4.11.2) activity (autosomal dominant). The molecular mass of the serum CD13 polypeptide of the propositus was larger than that of normal CD13, suggesting either a m...
journal_title:Clinical chemistry
pub_type: 杂志文章
doi:
更新日期:2001-02-01 00:00:00
abstract::Liquid scintillation counting of 3H-labeled whole-blood samples is severely impaired owing to quenching by blood pigments. In this study, dry oxidation and chemical solubilization followed by decolorization were the two general methods used to eliminate color quenching. Three blood volumes were examined: 0.25, 0.50, a...
journal_title:Clinical chemistry
pub_type: 杂志文章
doi:
更新日期:1981-04-01 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::At the clinical level, we have seen the emergence of a subspecialty of affective disorders within psychiatry. Mood clinics, depression units, and affective disorders centers are appearing in many academic and clinical settings, where clinical skill and knowledge can be concentrated and new research furthered. By using...
journal_title:Clinical chemistry
pub_type: 杂志文章
doi:
更新日期:1988-05-01 00:00:00
abstract:BACKGROUND:Galectin-3 has emerged as a potential useful novel biomarker for heart failure and cardiovascular disease (CVD). However, it remains unclear whether galectin-3 is associated with recurrent cardiovascular events during long-term follow-up of patients with stable coronary heart disease (CHD) after adjustment f...
journal_title:Clinical chemistry
pub_type: 杂志文章
doi:10.1373/clinchem.2016.257550
更新日期:2016-10-01 00:00:00
abstract::A method for determining platinum in biological materials by flameless atomic absorption spectrometry has been developed for use in pharmacological studies of platinum antitumor compounds. Tissue digests are analyzed in a heated graphite atomizer, with use of background correction and ramp temperature charring. We hav...
journal_title:Clinical chemistry
pub_type: 杂志文章
doi:
更新日期:1977-07-01 00:00:00
abstract::Erythromycin, phenazopyridine, methenamine mandelate, acetazolamide, and ascorbic acid reportedly interfere with the Porter-Silber reaction in the determination of urinary 17-hydroxycorticosteroids. Sodium bisulfite, added to the urine after hydrolysis with glucuronidase, removed almost all nonsteroidal interferences ...
journal_title:Clinical chemistry
pub_type: 杂志文章
doi:
更新日期:1977-11-01 00:00:00
abstract::The concentrations of 25 plasma proteins were measured in 22 patients with membranous nephropathy. For some large proteins, the plasma concentrations were increased; there were also large proteins with low plasma concentrations, but small or medium-sized proteins showed uniformly lower plasma concentration than the co...
journal_title:Clinical chemistry
pub_type: 杂志文章
doi:
更新日期:1997-07-01 00:00:00