Abstract:
:Four routine assays commonly used for monitoring plasma methotrexate (MTX) during high-dose therapy were validated by HPLC as the comparison method. MTX and its main metabolite, 7-hydroxymethotrexate (7-OHMTX), were analyzed by HPLC with postcolumn derivatization and fluorometric detection. About 200 clinical plasma samples from 13 children with acute lymphoblastic leukemia who received 5-8 g/m2 MTX as 24-h infusions were analyzed. The fraction of measured concentrations of MTX that were within 75-125% of the values obtained by HPLC were 64.5% for enzyme inhibition assay, 56.4% for fluorescence polarization immunoassay with polyclonal antibodies (FPIA1; Abbott), 58.9% for FPIA2 (with monoclonal antibodies; Abbott), and 46.4% for enzyme-multiplied immunoassay (Emit; Syva). All nonchromatographic procedures were subject to interferences from MTX plasma metabolites or endogenous substances. The interference from 7-OHMTX was, however, somewhat less pronounced for FPIA2 (monoclonal) than for FPIA1 (polyclonal).
journal_name
Clin Chemjournal_title
Clinical chemistryauthors
Albertioni F,Rask C,Eksborg S,Poulsen JH,Pettersson B,Beck O,Schroeder H,Peterson Csubject
Has Abstractpub_date
1996-01-01 00:00:00pages
39-44issue
1eissn
0009-9147issn
1530-8561journal_volume
42pub_type
杂志文章abstract::Noninvasive monitoring of blood/tissue glucose concentrations has been successfully accomplished in individual diabetic subjects by using near-infrared (NIR) spectroscopy coupled with chemometric methods. Three different spectrometer configurations were tested: a) a Fourier-transform infrared spectrometer with an indi...
journal_title:Clinical chemistry
pub_type: 杂志文章
doi:
更新日期:1992-09-01 00:00:00
abstract:BACKGROUND:ADB-PINACA and its 5-fluoropentyl analog 5F-ADB-PINACA are among the most potent synthetic cannabinoids tested to date, with several severe intoxication cases. ADB-PINACA and 5F-ADB-PINACA have a different legal status, depending on the country. Synthetic cannabinoid metabolites predominate in urine, making ...
journal_title:Clinical chemistry
pub_type: 杂志文章
doi:10.1373/clinchem.2016.267575
更新日期:2017-05-01 00:00:00
abstract:BACKGROUND:Concerns exist regarding how the 99th percentile upper reference limit (URL) of cardiac troponin (cTn) is determined and whether it should be derived from normal healthy individuals. CONTENT:The 99th percentile URL of cTn is an important criterion to standardize the diagnosis of myocardial infarction (MI) f...
journal_title:Clinical chemistry
pub_type: 杂志文章
doi:10.1093/clinchem/hvaa158
更新日期:2020-09-01 00:00:00
abstract::We report a case of hyperphosphatasemia in a 35-year-old patient with hepatitis B who underwent an orthotopic xenogeneic liver transplant. Marked increases in total alkaline phosphatase (ALP; EC 3.1.3.1) activity began 5 days posttransplantation (six times human normal) and increased to approximately 17 times normal a...
journal_title:Clinical chemistry
pub_type: 杂志文章
doi:
更新日期:1994-07-01 00:00:00
abstract::To evaluate a theoretical model for calculating free thyroid hormones, based on the law of mass action, we compared values for both calculated and measured free thyroxin and free triiodothyronine in a group of normal subjects. To determine whether the concentrations of circulating free hormones were also predictable f...
journal_title:Clinical chemistry
pub_type: 杂志文章
doi:
更新日期:1982-06-01 00:00:00
abstract::We established the validity of a quantitative reverse transcription (RT)-PCR assay for the RNA component of human telomerase (hTR), using the TaqMan fluorogenic detection system. Using this assay, we quantified hTR expression in two human pancreatic cancer cell lines, ASPC-1 and MIAPaCa-2. Our results indicated that h...
journal_title:Clinical chemistry
pub_type: 杂志文章
doi:
更新日期:1998-12-01 00:00:00
abstract::A highly sensitive two-site sandwich ELISA measuring total proinsulin immunoreactive material in serum or plasma was developed. The assay was based on two monoclonal antibodies, an anti-C-peptide antibody bound to a microtest plate and a biotin-labeled anti-insulin antibody. The detection limit (3 SD above zero value)...
journal_title:Clinical chemistry
pub_type: 杂志文章
doi:
更新日期:1993-10-01 00:00:00
abstract::Cerebrospinal fluid (CSF) from uninfected patients and from patients with bacterial and viral meningitis was analyzed by gas-liquid chromatography, with use of a flame ionization detector, and by gas chromatography-mass spectrometry. The resulting profiles were consistent and reproducible. Hydroxy acids were the compo...
journal_title:Clinical chemistry
pub_type: 杂志文章
doi:
更新日期:1984-07-01 00:00:00
abstract::We developed and evaluated a direct ultraviolet method for the enzymatic determination of uric acid in serum, plasma, or urine, without deproteinization of sera and plasma. Equilibrium and nonlinear curve-fitting kinetic options are evaluated and compared, and results of the proposed method are compared with those of ...
journal_title:Clinical chemistry
pub_type: 杂志文章
doi:
更新日期:1986-03-01 00:00:00
abstract:BACKGROUND:PS-341, a selective inhibitor of the proteasome, currently is under evaluation as an anticancer agent in multiple phase I clinical trials. In animal-model studies, PS-341 was rapidly removed from the vascular compartment and distributed widely, quickly approaching the limits of detection. An accurate pharmac...
journal_title:Clinical chemistry
pub_type: 杂志文章
doi:
更新日期:2000-05-01 00:00:00
abstract:BACKGROUND:Measurement of purine and pyrimidine metabolites presents complex problems for separations currently performed by HPLC and thin-layer chromatography in clinical practice. We developed a novel capillary electrophoresis method for this purpose. METHODS:Separations were performed in 60 mmol/L borate-2-amino-2-...
journal_title:Clinical chemistry
pub_type: 杂志文章
doi:
更新日期:1999-12-01 00:00:00
abstract::Using different substance concentrations in an aqueous 1.25 mmol/L solution of CaCl2 plus NaCl to a final solution ionic strength of 160 mmol/L, we tested six buffers for their effect on measurements of ionized calcium (Ca2+). Measured Ca2+ decreased with increasing ionic strength and pH. Increasing concentrations of ...
journal_title:Clinical chemistry
pub_type: 杂志文章
doi:
更新日期:1985-02-01 00:00:00
abstract::Major depression is one of the most common clinical problems seen by primary-care physicians. The prevalence is 5% to 10% in primary-care outpatients and 15% in medically ill inpatients. Despite this high prevalence rate, depression is frequently not accurately diagnosed. Evidence suggests that misdiagnosis often occu...
journal_title:Clinical chemistry
pub_type: 杂志文章,评审
doi:
更新日期:1988-05-01 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:Atherosclerosis is a complex, chronic disease that usually arises from the converging action of several pathogenic processes, including hypertension, hyperlipidemia, obesity, and the accumulation of oxidized LDL. Platelet-activating factor acetylhydrolase (PAF-AH) is a LDL- and HDL-bound enzyme that hydrolyz...
journal_title:Clinical chemistry
pub_type: 杂志文章
doi:10.1373/clinchem.2004.036863
更新日期:2004-11-01 00:00:00
abstract::Polyol concentrations were determined by selected-ion monitoring in 10 sample sets taken before dialysis and hourly for 4 h during dialysis. Predialysis concentrations (mumol/L) exceeding the upper limit of normal (mean + 2 SD; n = 33) were found for erythritol (25.4-59.0), threitol (11.5-46.7), and arabinitol (21.0-4...
journal_title:Clinical chemistry
pub_type: 杂志文章
doi:
更新日期:1990-12-01 00:00:00
abstract:BACKGROUND:Molecular analysis of plasma DNA during human pregnancy has led to the discovery that maternal plasma contains both fetal and maternal DNA. This valuable source of fetal DNA opens up new possibilities for noninvasive prenatal diagnosis. APPROACH:Published data from the last 3 years demonstrating the feasibi...
journal_title:Clinical chemistry
pub_type: 杂志文章,评审
doi:
更新日期:2000-12-01 00:00:00
abstract::A patient with the hyperviscosity syndrome exhibited very high concentrations of intermediate to small circulating immune complexes (CIC), involving 40-50% of the IgG present, with IgG rheumatoid factor activity. We demonstrate that precipitation of CIC by polyethylene glycol in the reaction mixture caused interferenc...
journal_title:Clinical chemistry
pub_type: 杂志文章
doi:
更新日期:1988-04-01 00:00:00
abstract::Creatine kinase (CK) isoenzymes MM, MB, and BB are located primarily in the cell cytosol, and increased CKMB in plasma is the hallmark of myocardial infarction. However, whether CK is released with reversible ischemic injury remains controversial. Here, we assessed plasma CK activity--cytosolic and mitochondrial CK--i...
journal_title:Clinical chemistry
pub_type: 杂志文章
doi:
更新日期:1997-03-01 00:00:00
abstract::We describe a simple method for evaluating thyroxine-binding globulin capacity and concentration from a single 1-cm blood spot on filter-paper used in a screening program for neonatal hypothyroidism. This method permits prompt diagnosis of about 90% of the infants with thyroxine-binding globulin deficiency in our abno...
journal_title:Clinical chemistry
pub_type: 杂志文章
doi:
更新日期:1980-03-01 00:00:00
abstract::A direct mehtod [Clin. Chim. Acta 46, 113 (1973)] for determination of inorganic phosphate in serum was adapted for use with a centrifugal analyzer. Contamination is minimized and analysis rate maximized by doing the reaction in the reagent wells of the transfer disc and by utilizing the high-speed spectrophotometric ...
journal_title:Clinical chemistry
pub_type: 杂志文章
doi:
更新日期:1976-02-01 00:00:00
abstract:BACKGROUND:Absolute plasma hepcidin concentrations measured by various procedures differ substantially, complicating interpretation of results and rendering reference intervals method dependent. We investigated the degree of equivalence achievable by harmonization and the identification of a commutable secondary refere...
journal_title:Clinical chemistry
pub_type: 杂志文章
doi:10.1373/clinchem.2016.256768
更新日期:2016-07-01 00:00:00
abstract:BACKGROUND:Genomic instability resulting in copy number variation is a hallmark of malignant transformation and may be identified through massive parallel sequencing. Tumor-specific cell free DNA (cfDNA) present in serum and plasma provides a real-time, easily accessible surrogate. METHODS:DNA was extracted from serum...
journal_title:Clinical chemistry
pub_type: 杂志文章
doi:10.1373/clinchem.2014.226571
更新日期:2015-01-01 00:00:00
abstract::We examined the variability of lipid and lipoprotein concentrations in plasma from a population sample from the Jerusalem Lipid Research Clinic study. Coefficients of variation of about 8% for plasma cholesterol, 11% to 15% for low- and high-density-lipoprotein cholesterol, and about 30% for triglyceride were reported...
journal_title:Clinical chemistry
pub_type: 杂志文章
doi:
更新日期:1985-07-01 00:00:00
abstract:BACKGROUND:Evidence suggests that systemic inflammation may adversely impact HDL function. In this study we sought to evaluate the independent and incremental predictive performance of GlycA-a novel serum inflammatory biomarker that is an aggregate measure of enzymatically glycosylated acute phase proteins-and HDL subc...
journal_title:Clinical chemistry
pub_type: 杂志文章
doi:10.1373/clinchem.2016.261636
更新日期:2017-01-01 00:00:00
abstract::The tricyclic antidepressants amitriptyline, nortriptyline, imipramine, and desipramine in serum of patients taking one of the drugs were quantified in two laboratories by high-performance liquid chromatography (HPLC) and enzyme-multiplied immunoassay (EMIT; Syva). Results for split samples were highly correlated, but...
journal_title:Clinical chemistry
pub_type: 杂志文章
doi:
更新日期:1988-11-01 00:00:00
abstract::We present a unified approach to the use of linear models and matrix least squares with the intention of providing a better understanding of the techniques themselves and of the statistics that arise from these techniques as they are used in clinical chemistry. Emphasis is placed on the importance of appropriate exper...
journal_title:Clinical chemistry
pub_type: 杂志文章
doi:
更新日期:1979-06-01 00:00:00
abstract::We compared results obtained with a commercial immunoradiometric assay kit for human thyrotropin in which monoclonal antibodies are used (Tandem -R TSH (ONE STEP) ImmunoRadioMetricAssay; Hybritech Inc.) with those obtained with two commercial radioimmunoassay methods: GAMMA-DAB [125I]HS-hTSH RIA (Clinical Assays) and ...
journal_title:Clinical chemistry
pub_type: 杂志文章
doi:
更新日期:1986-06-01 00:00:00
abstract::To determine the molar absorptivities of beta-NADH and beta-NAD at 260 nm, we purified the reduced form of the coenzyme by repeated anion-exchange chromatography. A NADH preparation was so obtained for which the 260 nm/340 nm absorbance ratio was 2.265. When calculated with epsilon 340 beta-NADH = 6.22 times 10-3 for ...
journal_title:Clinical chemistry
pub_type: 杂志文章
doi:
更新日期:1975-06-01 00:00:00
abstract:BACKGROUND:Diabetes mellitus has been historically divided into type 1 and type 2 diabetes, with type 1 being an autoimmune disease and type 2 being primarily a metabolic disease. CONTENT:The current diabetes classification scheme needs to be reevaluated because of the accumulating evidence of immune system involvemen...
journal_title:Clinical chemistry
pub_type: 杂志文章,评审
doi:10.1373/clinchem.2010.148270
更新日期:2011-02-01 00:00:00