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-fold at 30 and 37 degrees C. Adding chelators, 5 and 10 mmol/L, to serum stored at 37, 30, 25, 4, and -20 degrees C increased isoenzyme stability in some cases, but under certain conditions decreased it, especially at higher chelator concentrations, and more so for EGTA than for EDTA. Blood sampling into tubes prepared with chelators and storage of plasma has no advantage over serum stored in the presence of chelators. The most striking effect of chelators is their protective effect on thiols in the creatine kinase reagent. In the presence of EDTA, 2 mmol/L, the reagent is stable for at least a day at 25 degrees C or a week at 4 degrees C. The poor stability of glucose-6-phosphate dehydrogenase, which is nearly independent of chelators, is the limiting factor for reagent containing EDTA. Bis-Tris, a buffer recently recommended for assay of creatine kinase activity, is a weak chelator. Imidazole acetate buffer combined with EDTA yields activities identical to those found with Bis-Tris at assay temperatures of either 25 or 30 degrees C.
journal_name
Clin Chemjournal_title
Clinical chemistryauthors
Szasz G,Waldenström J,Gruber Wsubject
Has Abstractpub_date
1979-03-01 00:00:00pages
446-52issue
3eissn
0009-9147issn
1530-8561journal_volume
25pub_type
杂志文章abstract：:We describe a novel ion-selective electrode (ISE) system that can be used in the Abbott Vision analyzer. A reusable sensor pack and a disposable test pack have been miniaturized to approximately the size and weight of a conventional Vision test pack, thus eliminating the need for a separate ISE module. The sensor pack...
journal_title：Clinical chemistry
pub_type： 杂志文章
doi：
更新日期：1990-12-01 00:00:00
abstract：BACKGROUND:Platelet-derived microparticles (PMPs) are generally considered a marker of platelet activation in cardiovascular disease. We studied the extent to which PMP subpopulations parallel platelet activation in vitro and in vivo. METHODS:Using flow cytometry, we analyzed PMP subpopulations from resting and activa...
journal_title：Clinical chemistry
pub_type： 临床试验,杂志文章
doi：10.1373/clinchem.2005.057414
更新日期：2006-04-01 00:00:00
abstract：BACKGROUND:In recent years, a large number of studies have been published on the performance of glucose monitors. The quality of these reports is not known. METHODS:We searched the PubMed database for performance evaluations of handheld glucose monitors published from August 2002 to November 2006. Relevant articles we...
journal_title：Clinical chemistry
pub_type： 杂志文章,评审
doi：10.1373/clinchem.2006.083493
更新日期：2007-06-01 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：BACKGROUND:TMPRSS2:ERG fusions are promising prostate cancer biomarkers. Because they can occur in multiple forms in a single cancer specimen, we developed a quantitative PCR test that detects both type III and type VI TMPRSS2:ERG fusions. The assay is quantified from a standard curve determined with a plasmid-cloned t...
journal_title：Clinical chemistry
pub_type： 杂志文章
doi：10.1373/clinchem.2008.108845
更新日期：2008-12-01 00:00:00
abstract：BACKGROUND:Age-adjusted morbidity and mortality rates from coronary heart disease (CHD) are higher in men than in women. Androgens are suspected to be responsible for the male disadvantage. The genomic effect of androgens is mediated by the androgen receptor (AR), which has a polymorphic CAG repeat in exon 1. The numbe...
journal_title：Clinical chemistry
pub_type： 杂志文章,多中心研究
doi：10.1373/clinchem.2005.049262
更新日期：2005-07-01 00:00:00
abstract：:A rapid and precise immunoassay for quantification of total homocysteine in blood samples is presented. The method avoids the use of radioisotopes and chromatographic separations and relies on enzymatic conversion of homocysteine to S-adenosyl-L-homocysteine, followed by quantification of S-adenosyl-L-homocysteine by ...
journal_title：Clinical chemistry
pub_type： 杂志文章
doi：
更新日期：1998-02-01 00:00:00
abstract：:We have developed an HPLC method for measuring carbamylated hemoglobin (CarHb), based on the quantification of valine hydantoin formed from the released NH2-terminal carbamyl valine residue after acid hydrolysis of hemoglobin. In uremia, CarHb is produced by nonenzymatic post-translational modification of the terminal...
journal_title：Clinical chemistry
pub_type： 杂志文章
doi：
更新日期：1990-04-01 00:00:00
abstract：BACKGROUND:Increased plasma lipoprotein(a) [Lp(a)] concentrations have been reported to be an independent risk factor for coronary heart disease (CHD) in some prospective studies, but not in others. These inconsistencies may relate to a lack of standardization and the failure of some immunoassays to measure all apolipo...
journal_title：Clinical chemistry
pub_type： 临床试验,杂志文章
doi：
更新日期：1999-07-01 00:00:00
abstract：:Ornithine carbamoyltransferase (EC 2.1.3.3) activity is a sensitive, specific indicator of hepatocellular injury. This paper describes development of an improved automated procedure for measurement of this activity. Triethanolamine-ethylenediaminetetraacetate is used as a buffer, and activity is determined by measurin...
journal_title：Clinical chemistry
pub_type： 杂志文章
doi：
更新日期：1975-05-01 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：:This time-resolved immunofluorometric assay (IFMA) developed for measurement of placental protein 5 (PP5) involves two antibodies: a monoclonal anti-PP5 antibody attached to a solid phase and an europium(III) chelate-labeled polyclonal anti-PP5 antibody as a tracer. The measuring range is 0.05-100 micrograms/L and the...
journal_title：Clinical chemistry
pub_type： 杂志文章
doi：
更新日期：1988-08-01 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：:We compared five ion-selective electrodes (ISEs; AVL 985S, Baxter Lytening 2Z, Beckman EL-ISE, Ciba-Corning 654 Na/K/Li, and Nova CRT 11) and a colorimetric method (Ektachem) for determination of lithium with flame atomic absorption and atomic emission spectroscopy. We evaluated precision, recovery, interference by dr...
journal_title：Clinical chemistry
pub_type： 杂志文章
doi：
更新日期：1994-06-01 00:00:00
abstract：:We used flameless atomic absorption spectrophotometry to measure concentrations of Fe, Mo, Li, As, and Zn in cerebrospinal fluid (CSF) of patients with malignant brain tumors benign brain tumors, non-brain malignant tumors and control (non-neoplastic disease) patients. Mean (and SD) concentrations (microgram/L) of the...
journal_title：Clinical chemistry
pub_type： 杂志文章
doi：
更新日期：1986-12-01 00:00:00
abstract：:In considering factors that might influence measurement of free thyroxin (T4), we evaluated the proportion (%) of T4 that could be stripped from thyroxin-binding globulin (TBG). The percentage of free T4 was measured in serially diluted sera from four normal subjects, four patients with hyperthyroidism or hypothyroidi...
journal_title：Clinical chemistry
pub_type： 杂志文章
doi：
更新日期：1990-02-01 00:00:00
abstract：:We describe a rapid polarization fluoroimmunoassay for screening for the presence of barbiturates in urine. The single reagent is prepared by pre-mixing antiserum with a fluorescein-labeled barbiturate derivative as tracer. Use of a mixture of two sheep antisera, raised against different barbiturate immunogens, result...
journal_title：Clinical chemistry
pub_type： 杂志文章
doi：
更新日期：1984-11-01 00:00:00
abstract：:I evaluated use of the fluorescence polarization technique to measure neocarzinostatin, a proteinaceous antitumor antibiotic, and its antibody, in serum. The antigen (neocarzinostatin), labeled with fluorescein isothiocyanate, was allowed to interact with its antibody in a cuvet, in the instrument, yielding an increas...
journal_title：Clinical chemistry
pub_type： 杂志文章
doi：
更新日期：1978-12-01 00:00:00
abstract：:This rapid radioimmunoassay for aldosterone is performed directly on 100 microL of unprocessed plasma, with 125I-labeled aldosterone as the labeled antigen. Our use of steroid-free plasma in preparing the standard curve resulted in an overestimate of aldosterone; this problem was overcome by adding to such plasma a mi...
journal_title：Clinical chemistry
pub_type： 杂志文章
doi：
更新日期：1983-02-01 00:00:00
abstract：:Market forces have dramatically influenced the environment in which healthcare is delivered, but these changes do not need to be interpreted negatively by community laboratorians. Only total vertical integration of laboratory medicine can control episode-of-care cost. Opportunities also exist for horizontal integratio...
journal_title：Clinical chemistry
pub_type： 杂志文章,评审
doi：
更新日期：1996-05-01 00:00:00
abstract：:A total of 1357 polypeptides [946 acidic (isoelectric focusing) and 411 basic (nonequilibrium pH-gradient electrophoresis)] from human HeLa cells have been separated and catalogued with use of high-resolution two-dimensional gel electrophoresis. Of these polypeptides, 1266 were detected by labeling cells with [35S]met...
journal_title：Clinical chemistry
pub_type： 杂志文章
doi：
更新日期：1982-04-01 00:00:00
abstract：BACKGROUND:False-positive results are a common problem in real-time PCR identification of DNA sequences that differ from near neighbors by a single-nucleotide polymorphism (SNP) or deletion. Because of a lack of sufficient probe specificity, post-PCR analysis, such as a melting curve, is often required for mutation dif...
journal_title：Clinical chemistry
pub_type： 杂志文章
doi：10.1373/clinchem.2007.091488
更新日期：2007-12-01 00:00:00
abstract：:We describe a simple, rapid fluorometric assay for separate quantitative analysis of procainamide and N-acetylprocainamide in mixtures. The effective lenear range (fluorescence vs. concentration) in serum is 0.1 to 10.0 mg/liter, regardless of the ratio (by weight) of the two drugs from 1:10 to 10:1. Analytical recove...
journal_title：Clinical chemistry
pub_type： 杂志文章
doi：
更新日期：1975-12-01 00:00:00
abstract：:Pairs of values for serum triiodothyronine and serum triiodothyronine binding capacity were represented as maps of points for euthyroid populations (including subjects who were pregnant or were receiving estrogens) in the age groups 18-50, 51-64, 65-79, and greater than 80 years (504 subjects) and thyrotoxic populatio...
journal_title：Clinical chemistry
pub_type： 杂志文章
doi：
更新日期：1978-10-01 00:00:00
abstract：BACKGROUND:Plasma creatinine concentration and calculated creatinine clearance are of limited value as glomerular filtration rate (GFR) markers in patients with decompensated liver cirrhosis. We assessed plasma cystatin C as an indicator of GFR in such patients. METHODS:We studied 36 patients with decompensated liver ...
journal_title：Clinical chemistry
pub_type： 杂志文章
doi：
更新日期：2002-06-01 00:00:00
abstract：BACKGROUND:Measurement of serum thyroglobulin (Tg) is used to monitor patients after treatment for differentiated thyroid carcinoma (TC). Difficulty in using Tg as a biomarker of the recurrence of TC in many patients stems from the presence of endogenous anti-Tg autoantibodies (Tg-AAbs), which can interfere with immuno...
journal_title：Clinical chemistry
pub_type： 杂志文章
doi：10.1373/clinchem.2012.195594
更新日期：2013-06-01 00:00:00
abstract：BACKGROUND:We evaluated the completeness of reporting of diagnostic test accuracy (DTA) systematic reviews using the recently developed Preferred Reporting Items for Systematic Reviews and MetaAnalyses (PRISMA)-DTA guidelines. METHODS:MEDLINE® was searched for DTA systematic reviews published October 2017 to January 2...
journal_title：Clinical chemistry
pub_type： 杂志文章,meta分析
doi：10.1373/clinchem.2018.292987
更新日期：2019-02-01 00:00:00
abstract：:Light that penetrates scattering media shows nonlinearities that mask the broad and shallow perturbations made by trace analytes on the background illuminant spectrum. Narrow-band spectroscopic decomposition and deconvolution of such weak bands is a formidable analytical task that pushes the fundamentally linear spect...
journal_title：Clinical chemistry
pub_type： 杂志文章
doi：
更新日期：1994-09-01 00:00:00
abstract：BACKGROUND:Test repetition could be a readily modifiable component of laboratory utilization. Laboratory test repetition has not been rigorously studied at a population-based level. Our objective was to determine the prevalence of, and charges associated with, repetition of eight common laboratory tests. METHODS:We pe...
journal_title：Clinical chemistry
pub_type： 杂志文章
doi：10.1373/clinchem.2003.021220
更新日期：2003-12-01 00:00:00
abstract：BACKGROUND:Hyperglycosylated human chorionic gonadotropin (hCG-h) contains larger and more complex carbohydrate chains than regular human chorionic gonadotropin (hCG). hCG-h is thought to be the major form of hCG produced by testicular cancers and it has been suggested to play a key role in tumor invasion, but studies ...
journal_title：Clinical chemistry
pub_type： 杂志文章
doi：10.1373/clinchem.2012.183723
更新日期：2012-07-01 00:00:00
