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 dehydrogenase to yield glutamate and NADP+. The consumption of NADPH, measured by a two-point fixed-time assay, is proportional to the amount of creatinine in the sample. The assay is carried out in two steps: The first step eliminates background absorbance in hyperlipemic samples and endogenous ammonia through a "clearing system" and an isocitrate dehydrogenase-based "ammonia scavenger system"; the second step starts creatinine measurement. The method affords a simple, rapid, and sensitive assay with good precision and extended linearity; it employs working solutions stable at least 4 months. Test results compare closely with those of the isotope dilution-mass spectrometry Definitive Method, the HPLC procedure, and the fuller's earth method. The proposed method is not subject to interference from several metabolites or from the 72 drugs tested. Because it is easily automated, the method is suitable for routine work in clinical laboratories.
journal_name
Clin Chemjournal_title
Clinical chemistryauthors
Fossati P,Ponti M,Passoni G,Tarenghi G,Melzi d'Eril GV,Prencipe Lsubject
Has Abstractpub_date
1994-01-01 00:00:00pages
130-7issue
1eissn
0009-9147issn
1530-8561journal_volume
40pub_type
杂志文章abstract：BACKGROUND:At concentrations <500 microg/L, serum alpha-fetoprotein (AFP) has low specificity in the diagnosis of hepatocellular carcinoma (HCC), but monosialylated AFP (msAFP) is more specific for HCC. We describe two strategies for quantitative analysis of msAFP and explore their diagnostic accuracy in cases of HCC w...
journal_title：Clinical chemistry
pub_type： 杂志文章
doi：
更新日期：2002-07-01 00:00:00
abstract：:This paper compares a logistic curve and a mass-action curve in their ability to represent radioimmunoassay standard curves. A data base from 10 different assays is used in this comparison. Six of the 10 assays could be modeled equally well by either the logistic or the mass-action curve. In one case the mass-action c...
journal_title：Clinical chemistry
pub_type： 杂志文章
doi：
更新日期：1983-10-01 00:00:00
abstract：BACKGROUND:Simple, reproducible assays are needed for the quantification of sphingolipids, ceramide (Cer), and sphingoid bases. We developed an HPLC method for simultaneous quantification of total plasma concentrations of Cer, glucosylceramide (GlcCer), and ceramide trihexoside (CTH). METHODS:After addition of sphinga...
journal_title：Clinical chemistry
pub_type： 杂志文章
doi：10.1373/clinchem.2006.079012
更新日期：2007-04-01 00:00:00
abstract：:Carbohydrate-deficient transferrin (CDT) may now be the most valuable biological marker for diagnosis of alcohol abuse. We compared the diagnostic performance of two new CDT tests, Axis %CDT turbidimetric immunoassay (TIA) and Axis %CDT HPLC, against Specialty Laboratories' isoelectric focusing/immunoblotting/laser de...
journal_title：Clinical chemistry
pub_type： 临床试验,杂志文章
doi：
更新日期：1997-06-01 00:00:00
abstract：:In this immunoenzymatic assay for human lutropin (hLH) we used bi-specific antibodies (BiAbs) obtained from the fusion of two hybridomas producing antibodies to beta-D-galactosidase and hLh. The BiAb complexed with the enzyme beta-D-galactosidase was used as tracer in a double-determinant assay. We compared the assay ...
journal_title：Clinical chemistry
pub_type： 杂志文章
doi：
更新日期：1990-01-01 00:00:00
abstract：BACKGROUND:A unique requirement for the molecular diagnosis of mitochondrial DNA (mtDNA) disorders is the ability to detect heteroplasmic mtDNA mutations and to distinguish them from homoplasmic sequence variations before further testing (e.g., sequencing) is performed. We evaluated the potential utility of temporal te...
journal_title：Clinical chemistry
pub_type： 临床试验,杂志文章
doi：
更新日期：1999-08-01 00:00:00
abstract：:The commonly used methods of assessing the precision of the automated leukocyte differential have certain drawbacks that affect the validity and comparability of results. In the present report, we introduce a procedure based on building precision profiles from a large number of within-run imprecision experiments. The ...
journal_title：Clinical chemistry
pub_type： 杂志文章
doi：
更新日期：1996-07-01 00:00:00
abstract：:Urinary excretion of orally administered lactulose is used as an index of intestinal permeability. We have developed a simple thin-layer chromatographic technique for measuring lactulose in urine, using silica gel 60 plates and a propanol-borate solvent system. Lactulose concentrations as low as 62.5 mg/L can be detec...
journal_title：Clinical chemistry
pub_type： 杂志文章
doi：
更新日期：1987-07-01 00:00:00
abstract：BACKGROUND:First introduced into clinical microbiology laboratories in Europe, MALDI-TOF MS is being rapidly embraced by laboratories around the globe. Although it has multiple applications, its widespread adoption in clinical microbiology relates to its use as an inexpensive, easy, fast, and accurate method for identi...
journal_title：Clinical chemistry
pub_type： 杂志文章,评审
doi：10.1373/clinchem.2014.221770
更新日期：2015-01-01 00:00:00
abstract：:A three-parameter model for directly estimating imprecision profiles from replicated immunoassay results is compared with a six-parameter indirect profile model obtained by the usual method of combining error in the raw response measurements with the slope of the standard curve. Direct estimation is likely to be less ...
journal_title：Clinical chemistry
pub_type： 杂志文章
doi：
更新日期：1988-06-01 00:00:00
abstract：BACKGROUND:Clinical proteomics presents great promise in biology and medicine because of its potential for improving our understanding of diseases at the molecular level and for detecting disease-related biomarkers for diagnosis, prognosis, and prediction of therapeutic responses. To realize its full potential to impro...
journal_title：Clinical chemistry
pub_type： 杂志文章
doi：10.1373/clinchem.2010.156034
更新日期：2011-04-01 00:00:00
abstract：:We describe a liquid-chromatographic assay for AZT in human plasma and urine. This assay involves the use of two internal standards, allowing reference of AZT peaks to the appropriate internal standard, the choice depending on the range of concentrations encountered. This method is isocratic, specific, sensitive enoug...
journal_title：Clinical chemistry
pub_type： 杂志文章
doi：
更新日期：1988-08-01 00:00:00
abstract：BACKGROUND:A simple point-of-care method for measuring leukocyte counts in a doctor's office or emergency room could be of great importance. We developed a protocol for measuring cell count by disrupting the cell membrane and analyzing specific proteins within the cells and used it to analyze proteins from eosinophils ...
journal_title：Clinical chemistry
pub_type： 杂志文章
doi：10.1373/clinchem.2006.074021
更新日期：2007-02-01 00:00:00
abstract：BACKGROUND:The term "transrenal DNA" was coined in 2000 to signify that DNA in urine may come from the passage of plasma DNA through the kidney barrier. Although DNA in the urine has the potential to provide a completely noninvasive source of nucleic acids for molecular diagnosis, its existence remains controversial. ...
journal_title：Clinical chemistry
pub_type： 杂志文章
doi：10.1373/clinchem.2008.113530
更新日期：2009-04-01 00:00:00
abstract：:The deleterious, disruptive effects of estrogen mimics on the endocrine system were discovered after the compounds were released into the environment. Their chemical structure does not obviously resemble that of steroid hormones; hence, their estrogenic effects were totally unexpected. In addition to occupational expo...
journal_title：Clinical chemistry
pub_type： 杂志文章
doi：
更新日期：1995-12-01 00:00:00
abstract：BACKGROUND:In the workup of patients with suspected hereditary nonpolyposis colorectal cancer (HNPCC), detection of loss of heterozygosity (LOH) could help pinpoint the mismatch-repair (MMR) gene carrying the germline mutation, but analysis of microsatellite markers has proved unreliable for this purpose. We developed ...
journal_title：Clinical chemistry
pub_type： 杂志文章
doi：10.1373/clinchem.2008.108902
更新日期：2008-11-01 00:00:00
abstract：:This assay was developed to measure apolipoprotein (apo) B in blood samples spotted onto filter paper. The long-term aim is to detect young families with the dominantly inherited familial hypercholesterolemia, during current neonatal screening programs. The interassay CV was 5.6%, and apo B concentrations correlated c...
journal_title：Clinical chemistry
pub_type： 杂志文章
doi：
更新日期：1989-06-01 00:00:00
abstract：:To obtain the best estimates of the average intraindividual biological variability (CVb) in the concentrations of total cholesterol (TC), low-density lipoprotein cholesterol (LDLC), high-density lipoprotein cholesterol (HDLC), and triglyceride serum lipids in a person's blood, we evaluated results from 30 studies publ...
journal_title：Clinical chemistry
pub_type： 杂志文章,meta分析
doi：
更新日期：1993-06-01 00:00:00
abstract：:Numerous xenobiotics regulate cellular functions by altering transcription of target genes. Use of sensitive and specific biomarkers based on gene transcript levels may help clarify the shape of the dose-response curve in the low-dose region associated with human exposures to environmental concentrations of chemicals....
journal_title：Clinical chemistry
pub_type： 杂志文章,评审
doi：
更新日期：1995-12-01 00:00:00
abstract：:Diminished ability to utilize acetate (acetate intolerance) developed in a male patient on chronic hemodialysis after five years of maintenance dialysis. His ability to utilize lactate was also subnormal. We studied acetate metabolism in vitro by isolating lymphocytes from the patient's blood before dialysis and measu...
journal_title：Clinical chemistry
pub_type： 杂志文章
doi：
更新日期：1979-03-01 00:00:00
abstract：:A dissociation-enhanced lanthanide fluoroimmunoassay of serum cortisol based on time-resolved fluorescence is described. The assay is a direct assay, where cortisol immobilized on the wall of a microtiter-strip well competes with cortisol in the sample for the europium-labeled polyclonal antibody. The amount of bound ...
journal_title：Clinical chemistry
pub_type： 杂志文章
doi：
更新日期：1985-10-01 00:00:00
abstract：:We evaluated the performance of two homogeneous assays for quantifying HDL cholesterol (HDL-C) and compared them with the phosphotungstic acid (PTA)/ MgCl2 assay. Both homogeneous HDL-C assays were precise, having a within-run CV of < 1.20% and a between-run CV of < 4.07%. The HDL-C values (y) measured by the two homo...
journal_title：Clinical chemistry
pub_type： 杂志文章
doi：
更新日期：1997-06-01 00:00:00
abstract：:Considerable evidence has accrued in the last two decades to support the hypothesis that alterations in serotonergic neuronal function in the central nervous system occur in patients with major depression. These findings include the following: (a) reduced cerebrospinal fluid (CSF) concentrations of 5-hydroxyindoleacet...
journal_title：Clinical chemistry
pub_type： 杂志文章,评审
doi：
更新日期：1994-02-01 00:00:00
abstract：:A profile (chromatographic pattern) of the neutral and acidic metabolites present in cerebrospinal fluid from newborns and infants was obtained by gas-liquid chromatography. The metabolites are those extracted with ethyl acetate and diethyl ether. They are converted to trimethylsilyl ether derivatives, and chromatogra...
journal_title：Clinical chemistry
pub_type： 杂志文章
doi：
更新日期：1976-05-01 00:00:00
abstract：:We evaluated the Kallestad "Quanticoat" cortisol RIA for direct (no extraction) measurement of urinary free cortisol, which requires no solvent extraction. An analytical-recovery study showed a linear regression of y (measured) = 0.65x (added) + 37.5 micrograms/L (Sy.x = 21.4 micrograms/L, r = 0.978, n = 48). Recovery...
journal_title：Clinical chemistry
pub_type： 杂志文章
doi：
更新日期：1989-01-01 00:00:00
abstract：BACKGROUND:Multiple reaction monitoring mass spectrometry (MRM-MS) of peptides with stable isotope-labeled internal standards (SISs) is increasingly being used to develop quantitative assays for proteins in complex biological matrices. These assays can be highly precise and quantitative, but the frequent occurrence of ...
journal_title：Clinical chemistry
pub_type： 杂志文章
doi：10.1373/clinchem.2009.138420
更新日期：2010-02-01 00:00:00
abstract：BACKGROUND:Cardiac troponins are associated with cardiovascular risk in the general population, but whether temporal changes in cardiac troponin I provide independent prognostic information remains uncertain. Using a large community-based cohort with follow-up close to the present day, we aimed to investigate the assoc...
journal_title：Clinical chemistry
pub_type： 杂志文章
doi：10.1373/clinchem.2018.301069
更新日期：2019-07-01 00:00:00
abstract：:We describe a new and specific method for measurement of lecithin palmitic acid in amniotic fluid. Dipalmitoyl lecithin, the major alveolar surfactant, has previously been estimated by measuring the lecithin-sphingomyelin ratio, total lecithin, total phospholipid phosphorus, and (or) total palmitic acid. Our method is...
journal_title：Clinical chemistry
pub_type： 杂志文章
doi：
更新日期：1977-01-01 00:00:00
abstract：BACKGROUND:Current noninvasive assays for urothelial carcinoma (UC) lack clinical sensitivity and specificity. Given the utility of plasma cell-free DNA (cfDNA) biomarkers, the development of urinary cfDNA biomarkers may improve the diagnostic sensitivity. METHODS:We assessed copy number alterations (CNAs) by shallow ...
journal_title：Clinical chemistry
pub_type： 杂志文章
doi：10.1373/clinchem.2019.309633
更新日期：2020-01-01 00:00:00
abstract：:We report results for adjusted ionized calcium (at pH 7.4) and actual ionized calcium (at actual pH) in capillary blood from 183 patients with disorders of calcium metabolism (primary hyperparathyroidism, secondary hyperparathyroidism of malabsorption, primary hypoparathyroidism, Paget's disease, acromegaly, hypercalc...
journal_title：Clinical chemistry
pub_type： 杂志文章
doi：
更新日期：1990-03-01 00:00:00
