Abstract:
:An enzymatic, fluorometric method is described for determination of serum urea on silicone-rubber pads. In this method, the reagents are lyophilized on the surface of the pads, NADH on one side and a mixture of urease, glutamate dehydrogenase, and alpha-ketoglutarate on the other. The rate of disappearance of NADH fluorescence at 460nm (excitation wavelength, 340 nm) is monitored and related to serum urea concentration. The calibration curve is linear to 250 mg of urea per liter. The method affords a rapid, simple, and inexpensive means for urea assay, the results of which correlate well with automatic diacetyl monoxime method (correlation coefficient, 0.998).
journal_name
Clin Chemjournal_title
Clinical chemistryauthors
Kuan JC,Lau KY,Guilbault GGsubject
Has Abstractpub_date
1975-01-01 00:00:00pages
67-70issue
1eissn
0009-9147issn
1530-8561journal_volume
21pub_type
杂志文章abstract:BACKGROUND:Advances in the biological sciences and technology are providing molecular targets for diagnosing and treating cancer. Current classifications in surgical pathology for staging malignancies are based primarily on anatomic features (e.g., tumor-node-metastasis) and histopathology (e.g., grade). Microarrays to...
journal_title:Clinical chemistry
pub_type: 杂志文章,评审
doi:
更新日期:2002-08-01 00:00:00
abstract:BACKGROUND:Tacrolimus is metabolized predominantly to 13-O-demethyltacrolimus in the liver and intestine by cytochrome P450 3A (CYP3A). Patients with high concentrations of CYP3A5, a CYP3A isoenzyme polymorphically produced in these organs, require higher doses of tacrolimus, but the exact mechanism of this association...
journal_title:Clinical chemistry
pub_type: 杂志文章
doi:10.1373/clinchem.2005.050047
更新日期:2005-08-01 00:00:00
abstract::It has been hypothesized over many years that the autoimmune endocrine diseases are each due to antigen-specific defects in suppressor (regulatory) T lymphocyte function. There is now increasing evidence in studies of autoimmune thyroid disease and insulin-dependent diabetes mellitus that suppressor cells are activate...
journal_title:Clinical chemistry
pub_type: 杂志文章,评审
doi:
更新日期:1994-11-01 00:00:00
abstract::We have studied the influence of triglyceride-rich particles on the analytical bias of apolipoprotein B measurements by various immunoturbidimetric methods. Three commercially available methods grossly overestimate apolipoprotein B in samples with even moderately above-normal triglyceride concentrations. This effect i...
journal_title:Clinical chemistry
pub_type: 杂志文章
doi:
更新日期:1991-05-01 00:00:00
abstract::Single-spin density-gradient ultracentrifugation (DUC) has proven to be a reproducible method for detection of low-density-lipoprotein (LDL) heterogeneity. Recently another method has been described for this: gradient gel electrophoresis (GGE) of serum, a method that might be more suitable for screening. To gain insig...
journal_title:Clinical chemistry
pub_type: 杂志文章
doi:
更新日期:1991-06-01 00:00:00
abstract::In this new radioimmunoassay system for determination of amatoxins in urine and plasma, a novel chemical approach is used for antigen and 125I-tracer production, based on a detoxified alpha-amanitin derivative (aldoamanitin). Total assay time, including data processing, is less than 100 min. The lowest detectable conc...
journal_title:Clinical chemistry
pub_type: 杂志文章
doi:
更新日期:1986-09-01 00:00:00
abstract::Using high-performance liquid chromatography and gas chromatography, we reevaluated the 24-h influence of a serotonin- and dopamine-rich diet on platelet serotonin and serotonin, 5-hydroxyindoleacetic acid (5-HIAA), and major catecholamine metabolites in the urine of 15 healthy adults. Although there were significant ...
journal_title:Clinical chemistry
pub_type: 杂志文章
doi:
更新日期:1992-09-01 00:00:00
abstract:BACKGROUND:Quantification of 5-hydroxyindole-3-acetic acid (5-HIAA) in urine is useful in diagnosing and monitoring of patients with carcinoid tumors and in the study of serotonin (5-hydroxytryptamine) metabolism in various disorders. We describe an automated method that incorporates on-line solid-phase extraction (SPE...
journal_title:Clinical chemistry
pub_type: 杂志文章
doi:10.1373/clinchem.2005.050062
更新日期:2005-09-01 00:00:00
abstract::A gas-chromatographic method for urinary organic acid analysis is described, designed to be used routinely for the diagnosis of organic aciduria. It involves extraction of urine with ethyl acetate, dehydration of extract residues, and trimethylsilylation. Organic acids are identified by using an extensive list of rete...
journal_title:Clinical chemistry
pub_type: 杂志文章
doi:
更新日期:1980-12-01 00:00:00
abstract:BACKGROUND:Remnant lipoprotein-cholesterol (RLP-C) concentrations in sera of healthy individuals are very low (0.080-0.437 mmol/L), making conventional cholesterol methods poorly suited to this purpose. We have developed a highly sensitive cholesterol assay (CD method) and applied it to the RLP-C assay. METHODS:The CD...
journal_title:Clinical chemistry
pub_type: 杂志文章
doi:
更新日期:2002-05-01 00:00:00
abstract::I describe a micro-scale method for determining lead in whole blood by utilizing a graphite furnace. Sample pretreatment consists of fivefold dilution with a dilute surfactant. The method is directly calibrated with lead standards prepared in dilute HNO3. To eliminate a small, nonspecific absorption signal from the...
journal_title:Clinical chemistry
pub_type: 杂志文章
doi:
更新日期:1975-04-01 00:00:00
abstract::Changes in values for myoglobin, total creatine kinase (EC 2.7.3.2), and creatine kinase B-subunit in the serum of patients with thyroid disease are compared with values for these during the 24-h after myocardial infarction. Concentrations of all three of these muscle-derived proteins were significantly higher than no...
journal_title:Clinical chemistry
pub_type: 杂志文章
doi:
更新日期:1984-01-01 00:00:00
abstract::Crystalline preparations of diiodotyrosine contain trace quantities of thyroxine that can be detected by several competitive radioassays and by chromatography on Sephadex. Spontaneous coupling of diiodotyrosine to thyroxine during iodination of tyrosine and coprecipitation of hormone with diiodotyrosine crystals are l...
journal_title:Clinical chemistry
pub_type: 杂志文章
doi:
更新日期:1978-10-01 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:BACKGROUND:Mass spectrometric assays could potentially replace protein immunoassays in many applications. Previous studies have demonstrated the utility of liquid chromatography-multiple-reaction monitoring-mass spectrometry (LC-MRM/MS) for the quantification of proteins in biological samples, and many examples of the ...
journal_title:Clinical chemistry
pub_type: 杂志文章
doi:10.1373/clinchem.2011.173856
更新日期:2012-04-01 00:00:00
abstract::The molar absorptivity of unconjugated bilirubin in caffeine reagent is independent of the protein matrix. This finding, together with the simplicity of a dilution step for direct spectrophotometry, will improve the calibration methods of bilirubin and make them more nearly accurate. This is encouraging for the develo...
journal_title:Clinical chemistry
pub_type: 杂志文章
doi:
更新日期:1986-07-01 00:00:00
abstract:BACKGROUND:Increasing numbers of patients are presenting worldwide to emergency departments with suspected myocardial infarction. The use of point-of-care troponin assays might enable faster decision-making in this high-risk population and reduce the burden on emergency facilities. Here, we evaluate the diagnostic perf...
journal_title:Clinical chemistry
pub_type: 杂志文章
doi:10.1373/clinchem.2019.307405
更新日期:2019-12-01 00:00:00
abstract:BACKGROUND:Cystic fibrosis is a life-threatening genetic disorder that has been associated with mutations in the CFTR [cystic fibrosis transmembrane conductance regulator (ATP-binding cassette sub-family C, member 7)] gene. Hundreds of CFTR mutations have been detected to date. Current CFTR genotyping assays target a s...
journal_title:Clinical chemistry
pub_type: 杂志文章
doi:10.1373/clinchem.2013.206466
更新日期:2013-10-01 00:00:00
abstract::Highly purified human lactate dehydrogenases I and V were assayed in 17 different buffers, at a variety of reaction pH's. Diethanolamine and 2-amino-2-methyl-1,3-propanediol provided the best measurements of the enzyme, assayed lactate-to-pyruvate. However, the commercial preparation of 2-amino-2-methyl-1,3-propanedio...
journal_title:Clinical chemistry
pub_type: 杂志文章
doi:
更新日期:1976-11-01 00:00:00
abstract:BACKGROUND:The TDx Fetal Lung Maturity II (FLM II) assay uses amniotic fluid to assess lung maturity of the unborn infant. We investigated common preanalytical factors that influence FLM results, including centrifugation, sample storage, and contamination by whole blood. METHODS:We tested 18 specimens after centrifuga...
journal_title:Clinical chemistry
pub_type: 杂志文章
doi:10.1373/49.6.935
更新日期:2003-06-01 00:00:00
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...
journal_title:Clinical chemistry
pub_type: 杂志文章
doi:
更新日期:1986-01-01 00:00:00
abstract::A modified gas-liquid chromatographic method for determining plasma concentrations of bupivacaine and lidocaine is described, with cyclizine as an internal standard. The extraction procedure requires no solvent evaporation, thus overcoming the problem of drug volatility. Concentrations as low as 0.1 mg/liter can be de...
journal_title:Clinical chemistry
pub_type: 杂志文章
doi:
更新日期:1978-09-01 00:00:00
abstract:BACKGROUND:Biochemical markers of bone turnover can provide prognostic information about the risk of osteoporotic fracture and are useful tools for monitoring efficacy of antiresorptive therapy. A serum-based automated assay may be of better clinical value than urinary markers because of lower imprecision and day-to-da...
journal_title:Clinical chemistry
pub_type: 杂志文章
doi:
更新日期:2001-04-01 00:00:00
abstract:BACKGROUND:Monogenic autoinflammatory diseases are caused by pathogenic variants in genes that regulate innate immune responses, and are characterized by sterile systemic inflammatory episodes. Since symptoms can overlap within this rapidly expanding disease category, accurate genetic diagnosis is of the utmost importa...
journal_title:Clinical chemistry
pub_type: 杂志文章
doi:10.1093/clinchem/hvaa024
更新日期:2020-04-01 00:00:00
abstract::We describe the process of certification for a gamma-glutamyltransferase reference material (CRM no. 319). Fifteen laboratories participated to this interlaboratory evaluation. All steps of the measurements were controlled in an effort to locate potential sources of variations. In particular, the exclusion of some dat...
journal_title:Clinical chemistry
pub_type: 杂志文章
doi:
更新日期:1987-11-01 00:00:00
abstract::Single-strand conformation polymorphism (SSCP) analysis is widely used to prescreen mutations in p53 gene. However, standardization of SSCP to detect p53 mutations has rarely been pursued so far. We have developed complete conditions for a temperature-controlled nonradioactive SSCP for mutation detection in amplified ...
journal_title:Clinical chemistry
pub_type: 杂志文章
doi:
更新日期:1997-12-01 00:00:00
abstract:BACKGROUND:The majority of patients with chronic kidney disease are diagnosed and monitored in primary care. Glomerular filtration rate (GFR) is a key marker of renal function, but direct measurement is invasive; in routine practice, equations are used for estimated GFR (eGFR) from serum creatinine. We systematically a...
journal_title:Clinical chemistry
pub_type: 杂志文章,meta分析
doi:10.1373/clinchem.2017.276683
更新日期:2018-03-01 00:00:00
abstract:BACKGROUND:An association has been described between mortality in children with meningococcal disease and functional polymorphisms in the interleukin-1 (IL1) cluster. We undertook a multicenter study to evaluate associations of these polymorphisms in a Central European population. PATIENTS AND METHODS:The study involv...
journal_title:Clinical chemistry
pub_type: 杂志文章,多中心研究
doi:10.1373/clinchem.2005.058537
更新日期:2006-03-01 00:00:00
abstract::We evaluated the homogeneous enzyme immunoassay ("EMIT") of serum thyroxine with use of an ABA- 100 Bichromatic Analyzer, modified with an auxiliary dispenser syringe and a dual probe assembly. The modification allows two reagents to be dispensed at one time. The sera must be pre-treated with 0.1 mol/liter NaOH. The p...
journal_title:Clinical chemistry
pub_type: 杂志文章
doi:
更新日期:1978-01-01 00:00:00
abstract:BACKGROUND:An assay using a mouse antisialyl Lewis X (sLeX) antibody (CSLEX-1) is used clinically for screening and monitoring patients with breast cancer in Japan. However, the IgM isoform of CSLEX-1 is not preferred for the assay because the bulkiness of IgM generally causes poor accessibility to the antigen. To solv...
journal_title:Clinical chemistry
pub_type: 杂志文章
doi:10.1373/clinchem.2016.260968
更新日期:2016-11-01 00:00:00