Abstract：
:We report a simple, enzymatic, end point method for determining nitrate in serum and urine with use of nitrate reductase from Aspergillus sp. (EC 1.6.6.2). The decrease in absorbance at 340 nm as a result of the oxidation of beta-NADPH is measured. We used FAD as a supplementary electron carrier and added an internal standard to avoid interference from possible inhibitors of the enzymatic reaction. The method was linear from 5 to 200 mumol/L nitrate in serum. Within-run (n = 12) and total (n = 14 days) imprecisions (CV) were 5.1-7.7% and 6.2-9.8%, respectively, at 20-90 mumol/L nitrate in serum. Recoveries of added nitrate were 80-106%. The median (range) concentration in serum of 20 healthy subjects was 16 (0-42) mumol/L.
journal_name
Clin Chemjournal_title
Clinical chemistryauthors
Bories PN,Bories Csubject
Has Abstractpub_date
1995-06-01 00:00:00pages
904-7issue
6 Pt 1eissn
0009-9147issn
1530-8561journal_volume
41pub_type
杂志文章abstract：:Clinically relevant interassay precision profiles for thyrotropin (thyroid-stimulating hormone; TSH) were constructed with human serum pools measured over 4-8 weeks by six immunometric assays, in at least two different reagent lots. Functional sensitivities (the concentration at which the interassay CV is < or = 20%) ...
journal_title：Clinical chemistry
pub_type： 杂志文章
doi：
更新日期：1995-03-01 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：:Autocorrelation of clinical chemistry quality-control (Q/C) measurements causes one of the basic assumptions underlying the use of Levey-Jennings control charts to be violated and performance to be degraded. This is the requirement that the observations be statistically independent. We present a proposal for a new app...
journal_title：Clinical chemistry
pub_type： 杂志文章
doi：
更新日期：1988-07-01 00:00:00
abstract：BACKGROUND:Standardization of clinical measurements of C-reactive protein (CRP) is based on the availability of reference materials. The serum protein reference material ERM-DA470 was used as a calibrant for various commercially available immunoassays but has now been exhausted. The recently released ERM-DA470k/IFCC wa...
journal_title：Clinical chemistry
pub_type： 杂志文章
doi：10.1373/clinchem.2010.147124
更新日期：2010-09-01 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：:Brain proteins extractable with distilled water or 9 mol/L urea were subjected to two-dimensional gel electrophoresis. They are examined in relation to the identification of actin, tubulin, neurofilament proteins, glial fibrillary acidic protein; proteins of human embryonic neocortex, synaptosomes, myelin, and plasma;...
journal_title：Clinical chemistry
pub_type： 杂志文章
doi：
更新日期：1982-04-01 00:00:00
abstract：:We have developed an interactive statistical quality-control system for the small- to medium-sized radioimmunoassay laboratory, which can be used in a programmable desk-top calculator instead of the medium- or large-scale computer systems usually required. The design of this quality-control system is modeled after the...
journal_title：Clinical chemistry
pub_type： 杂志文章
doi：
更新日期：1978-07-01 00:00:00
abstract：:A fixed-time incubation method for measuring acetylsalicylic acid esterase was improved by using a higher concentration of the substrate, acetylsalicylic acid, and an activator, Ca2+. The enzymatic activity in serum was 25-fold that measured by earlier methods. Inhibition studies showed a pattern similar to that repor...
journal_title：Clinical chemistry
pub_type： 杂志文章
doi：
更新日期：1983-03-01 00:00:00
abstract：BACKGROUND:The purpose of this study was to assess the feasibility of infrared (IR) spectroscopy for the simultaneous quantification of serum LDL-cholesterol (LDL-C) and HDL-cholesterol (HDL-C) concentrations. METHODS:Serum samples (n = 90) were obtained. Duplicate aliquots (5 microL) of the serum specimens were dried...
journal_title：Clinical chemistry
pub_type： 杂志文章
doi：
更新日期：2002-03-01 00:00:00
abstract：:We report a continuous-flow fluorometric method for total urinary estrogens that involves the Kober reaction, with extraction of the reaction product into dichloroethane containing trichloroacetic acid as described by Hahnel and Jones [Clin. Chim. Acta 16, 185 (1967)]. The dichloroethane extraction gives greater stabi...
journal_title：Clinical chemistry
pub_type： 杂志文章
doi：
更新日期：1977-10-01 00:00:00
abstract：:The purpose of Medicare's Demonstration of Competitive Bidding for Clinical Laboratory Services is to determine whether competitive bidding can be used to provide quality laboratory services at prices below current Medicare reimbursement rates. Here, we present key features of the preliminary design for the demonstrat...
journal_title：Clinical chemistry
pub_type： 杂志文章
doi：
更新日期：1998-08-01 00:00:00
abstract：BACKGROUND:Genotyping methods that reveal single-nucleotide differences are useful for a wide range of applications. We used digestion of 3-way DNA junctions in a novel technology, OneCutEventAmplificatioN (OCEAN) that allows sequence-specific signal generation and amplification. We combined OCEAN with peptide-nucleic-...
journal_title：Clinical chemistry
pub_type： 杂志文章
doi：10.1373/clinchem.2006.068817
更新日期：2006-10-01 00:00:00
abstract：:We describe the production and characterization of a high-affinity monoclonal antibody, HB-22, for apolipoprotein (apo) A-I, a major protein of human high-density lipoproteins (HDL). Including Tween 20 in the reaction mixture increased the binding capacity of HB-22 to apo A-I. HB-22 showed monospecific reactivity with...
journal_title：Clinical chemistry
pub_type： 杂志文章
doi：
更新日期：1995-08-01 00:00:00
abstract：BACKGROUND:High circulating concentrations of N-terminal fragments of A- and B-type natriuretic peptides (NT-proANP and NT-proBNP) identify patients with impaired cardiac function. ProANP-derived peptides are particularly sensitive to increased preload of the heart and proBNP-derived peptides to increased afterload; th...
journal_title：Clinical chemistry
pub_type： 杂志文章
doi：10.1373/clinchem.2004.039891
更新日期：2005-04-01 00:00:00
abstract：BACKGROUND:Adequate detection of designer steroids in the urine of athletes is still a challenge in doping control analysis and requires knowledge of steroid metabolism. In this study we investigated whether uPA(+/+)-SCID mice carrying functional primary human hepatocytes in their liver would provide a suitable alterna...
journal_title：Clinical chemistry
pub_type： 杂志文章
doi：10.1373/clinchem.2008.119396
更新日期：2009-10-01 00:00:00
abstract：BACKGROUND:Distinguishing adenocarcinoma and squamous cell carcinoma subtypes of non-small cell lung cancers is critical to patient care. Preoperative minimally-invasive biopsy techniques, such as fine needle aspiration (FNA), are increasingly used for lung cancer diagnosis and subtyping. Yet, histologic distinction of...
journal_title：Clinical chemistry
pub_type： 杂志文章
doi：10.1093/clinchem/hvaa207
更新日期：2020-11-01 00:00:00
abstract：:We evaluated a newly developed solid-phase immunoassay (EIA) of terminal deoxynucleotidyl transferase (TdT, EC 2.7.7.3) and compared it with the enzymatic assay of TdT involving DNA polymerase. We assessed the precision, performance characteristics, and clinical efficacy of the EIA procedure, using 249 specimens of pe...
journal_title：Clinical chemistry
pub_type： 杂志文章
doi：
更新日期：1987-02-01 00:00:00
abstract：:To compare six assays of hyaluronan (hyaluronic acid; HYA) in serum, developed in different laboratories, we analyzed 10 samples from each of three groups: healthy persons, patients with primary biliary cirrhosis, and patients with rheumatoid arthritis. All the assays are based on the use of affinity proteins specific...
journal_title：Clinical chemistry
pub_type： 杂志文章
doi：
更新日期：1992-01-01 00:00:00
abstract：:To investigate the use of streptavidin-hapten derivatives as potential protein-tracer conjugates for competitive-type immunoassays, we labeled streptavidin with cortisol and compared biotin-binding activity of the conjugates with that of unlabeled streptavidin. In this model system, streptavidin labeled with one to ap...
journal_title：Clinical chemistry
pub_type： 杂志文章
doi：
更新日期：1991-01-01 00:00:00
abstract：:This semi-automated colorimetric assay for the MB isoenzyme of creatine kinase (EC 2.7.3.2) is based on a monoclonal antibody ("Conan-MB") specific for this isoenzyme and is a modification of a previously published method (Vaidya et al., Clin Chem 1986;32:657-63). A 0.64-cm bead coated with 2 to 3 micrograms of antibo...
journal_title：Clinical chemistry
pub_type： 杂志文章
doi：
更新日期：1988-03-01 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：:We describe the measurement of rheumatoid factor in human sera with a rate nephelometer. The National Reference Preparation for Rheumatoid Factors is used to calibrate the assay in International Units. We used Hyland Positive Control, Level I, as a secondary standard. The standard curve is exponential, but is linear w...
journal_title：Clinical chemistry
pub_type： 杂志文章
doi：
更新日期：1979-11-01 00:00:00
abstract：BACKGROUND:Lectin-like oxidized LDL receptor 1 (LOX-1) is implicated in atherothrombotic diseases. Activation of LOX-1 in humans can be evaluated by use of the LOX index, obtained by multiplying the circulating concentration of LOX-1 ligands containing apolipoprotein B (LAB) times that of the soluble form of LOX-1 (sLO...
journal_title：Clinical chemistry
pub_type： 杂志文章
doi：10.1373/clinchem.2009.140707
更新日期：2010-04-01 00:00:00
abstract：:We describe a chromatographic system involving a high-performance chemically-bonded reverse-phase column and fluorescence detection for measurement of indoles in urine. We controlled retention and selectivity by optimizing the methanol content and pH of the mobile phase. Six reference indoles were separated in less th...
journal_title：Clinical chemistry
pub_type： 杂志文章
doi：
更新日期：1976-02-01 00:00:00
abstract：:Correlation between coronary heart disease and lipoprotein size and composition is well documented. Within the low-density lipoprotein (LDL) family the small LDL particles are associated with increased risk of coronary heart disease. These particles also have increased apolipoprotein (apo) B content. The appearance of...
journal_title：Clinical chemistry
pub_type： 杂志文章,评审
doi：
更新日期：1995-01-01 00:00:00
abstract：:We assessed the accuracy and precision of seven commercial kits for serum ferritin. The concentration of ferritin as determined by these assays for a liver ferritin reference standard, a human heart ferritin standard, and normal sera correlated highly, but the absolute values varied widely. Use of an international ref...
journal_title：Clinical chemistry
pub_type： 杂志文章
doi：
更新日期：1984-02-01 00:00:00
abstract：BACKGROUND:In patient and population samples, generation of analytical results that are comparable and independent of the measurement system, time, and location is essential for the utility of laboratory information supplied in healthcare. Obtaining analytical measurement results with such characteristics is the aim of...
journal_title：Clinical chemistry
pub_type： 杂志文章,评审
doi：10.1373/clinchem.2008.107052
更新日期：2009-06-01 00:00:00
abstract：:We describe the case of a three-year-old girl with Wilms' tumor, whose serum showed at least a fivefold increase in relative viscosity although concentrations of albumin and immunoglobulins were normal. An unusual electrophoretogram of serum protein prompted further investigation. The increased viscosity was caused by...
journal_title：Clinical chemistry
pub_type： 杂志文章
doi：
更新日期：1984-06-01 00:00:00
abstract：BACKGROUND:Yersinia pestis, the causative agent of the zoonotic infection plague, is a major concern as a potential bioweapon. Current real-time PCR assays used for Y. pestis detection are based on plasmid targets, some of which may generate false-positive results. METHODS:Using the yp48 gene of Y. pestis, we designed...
journal_title：Clinical chemistry
pub_type： 杂志文章
doi：10.1373/clinchem.2005.051839
更新日期：2005-10-01 00:00:00
abstract：:A reaction of urea, o-phthalaldehyde and N-(1-naphthyl)ethylenediamine is described for measurement of urea by manual, continuous-flow, and kinetic methods. The continuous-flow system requires 25 mu-l of sample; 40 samples can be analyzed per hour. The kinetic method requires no enzymes, has no lag phase, and has good...
journal_title：Clinical chemistry
pub_type： 杂志文章
doi：
更新日期：1975-07-01 00:00:00
