Abstract:
:We describe the use of electron-capture gas chromatography or reversed-phase "high-performance" liquid chromatography for concurrent analysis for diazepam and nordiazepam in serum. In the gas-chromatographic analysis our use of a new chemically deactivated stationary liquid phase, SP 2250-DB (Supelco, Inc.), resulted in improved chromatographic sensitivity and peak symmetry for the two benzodiazepines as compared to that obtained with either OV-17or OV-1 phases. Steady-state concentrations of diazepam and nordiazepam in serum as determined by gas-liquid chromatography correlated closely with those found by liquid-liquid chromatography.
journal_name
Clin Chemjournal_title
Clinical chemistryauthors
Wallace JE,Schwertner HA,Shimek EL Jrsubject
Has Abstractpub_date
1979-07-01 00:00:00pages
1296-300issue
7eissn
0009-9147issn
1530-8561journal_volume
25pub_type
杂志文章abstract::Establishing associations between environmental agents and disease presents challenges to both epidemiologists and toxicologists, particularly in cases of complex gene-environment interactions and when there is a long latency between exposure and disease. Biologic markers, physiological signals that reflect exposure, ...
journal_title:Clinical chemistry
pub_type: 杂志文章,评审
doi:
更新日期:1994-07-01 00:00:00
abstract:BACKGROUND:It is important that cardiac troponin be measured accurately with a robust method to limit false results with potentially adverse clinical outcomes. In this study, we characterized the robustness of 4 analytical platforms by measuring the outlier rate between duplicate results. METHODS:We measured cardiac t...
journal_title:Clinical chemistry
pub_type: 杂志文章
doi:10.1373/clinchem.2010.159830
更新日期:2011-05-01 00:00:00
abstract::Clottable fibrinogen in human plasma was determined by measuring spectrophotometrically the increase in turbidity with time due to the fibrinogen-fibrin conversion with thrombin. From the maximal absorbance, Amax, at 450 nm obtained 2 min or less after thrombin as added to plasma, we estimated the fibrinogen concentra...
journal_title:Clinical chemistry
pub_type: 杂志文章
doi:
更新日期:1978-02-01 00:00:00
abstract:BACKGROUND:D-2-Hydroxyglutaric aciduria (D-2-HGA), L-2-hydroxyglutaric aciduria (L-2-HGA), and the combined D/L-2-hydroxyglutaric aciduria (D/L-2-HGA) are poorly understood organic acidurias. To investigate the usefulness of cultured human skin fibroblasts for both diagnostic and research purposes, we measured disease-...
journal_title:Clinical chemistry
pub_type: 杂志文章
doi:10.1373/49.7.1133
更新日期:2003-07-01 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::We have assessed the technical performance and robustness of NycoCard CRP Whole Blood, a near-patient test for C-reactive protein (CRP), when used in realistic daily routine situations in general practice clinics (GPC). Thirteen GPCs participated, five of them with technician staff. From 898 patients, split-sample mea...
journal_title:Clinical chemistry
pub_type: 杂志文章
doi:
更新日期:1997-11-01 00:00:00
abstract::Radiometric, colorimetric, and two immunochemical methods for measuring total iron-binding capacity are compared. We evaluated the procedures on the basis of precision, applicability to a pediatric population, and accuracy as assessed by analytical recovery of purified transferrin. The immunoephelometric assay for tra...
journal_title:Clinical chemistry
pub_type: 杂志文章
doi:
更新日期:1978-10-01 00:00:00
abstract::We describe a fully automated method of analysis for plasma epinephrine and norepinephrine by use of a two-column system of "high-performance" liquid chromatography. Catecholamines in deproteinized plasma are purified on the first (preparation) column, then transferred automatically to the second (analytical) column i...
journal_title:Clinical chemistry
pub_type: 杂志文章
doi:
更新日期:1981-12-01 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::Demonstrable quality of laboratory services entails two parts. First, one needs a quality policy statement, identification of user needs, choice of measurement procedures, reference measurement system to provide traceability, control materials, and proficiency testing with materials having reference-measurement-assign...
journal_title:Clinical chemistry
pub_type: 杂志文章,评审
doi:
更新日期:1994-07-01 00:00:00
abstract:BACKGROUND:There have been no large-scale analyses of resource utilization comparing the overall costs to treat pediatric patients vs adult patients. Likewise, there have been no studies evaluating the costs of the various components of hospitalization (e.g., accommodation, laboratory, radiology, and drugs) among adult...
journal_title:Clinical chemistry
pub_type: 杂志文章
doi:
更新日期:2002-01-01 00:00:00
abstract::The time-course of the contamination of exogenous hydrogen from cigarette smoke on postprandial breath hydrogen concentration was evaluated in 10 subjects, six regular smokers and four occasional smokers. Breath hydrogen values were determined by gas chromatography 10 min, 5 min, and immediately prior to smoking a fil...
journal_title:Clinical chemistry
pub_type: 杂志文章
doi:
更新日期:1983-11-01 00:00:00
abstract::In this liquid-chromatographic method for the determination of bromide in human serum, an important and unique feature is pre-analysis ultrafiltration of the sample, which effectively removes proteins. The chromatographic system consists of an anion-exchange column (Whatman Partisil SAX 10-micron particles), an isocra...
journal_title:Clinical chemistry
pub_type: 杂志文章
doi:
更新日期:1984-05-01 00:00:00
abstract::Quantification of ethanol by a radiative energy attenuation (REA) technique was evaluated and compared with results by gas-liquid chromatography (GLC) and by the Du Pont aca. Within-assay CVs were less than 5.5%. Between-assay CVs ranged from 1.9% to 6.0% for serum and blood controls at concentrations of 0.5, 1.0, and...
journal_title:Clinical chemistry
pub_type: 杂志文章
doi:
更新日期:1984-11-01 00:00:00
abstract::Peroxidation of lipids is believed to play a key role in various degenerative diseases. However, few simple tests are able to detect individual susceptibility or resistance to peroxidation. Measurement of the basal concentrations of lipid peroxides in plasma is not satisfactory because they are so low. Therefore, we d...
journal_title:Clinical chemistry
pub_type: 杂志文章
doi:
更新日期:1991-10-01 00:00:00
abstract:BACKGROUND:Immunoassays specific for 1-84 parathyroid hormone (PTH) reportedly reflect the bioactivity of PTH; however, PTH immunoassays can be susceptible to interference by cross-reacting PTH fragments. In addition, these assays currently lack standardization. A methodology using immunocapture purification with liqui...
journal_title:Clinical chemistry
pub_type: 杂志文章
doi:10.1373/clinchem.2009.134643
更新日期:2010-02-01 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::To study the effect of fatty acid chain saturation on the fluorescence polarization assay as a measure of fetal lung maturity, we used purified phospholipids isolated from human amniotic fluid and various commercial phospholipids. We found that the fluorescence polarization value decreased as the concentration of unsa...
journal_title:Clinical chemistry
pub_type: 杂志文章
doi:
更新日期:1986-03-01 00:00:00
abstract:BACKGROUND:Identifying novel risk markers in cardiovascular patients remains a research priority. Longer follow-up generally is considered favorable in such studies, but associations of interest may become attenuated with increasing follow-up. This issue has not been adequately addressed in the context of patient cohor...
journal_title:Clinical chemistry
pub_type: 杂志文章
doi:10.1373/clinchem.2016.263202
更新日期:2017-03-01 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::Four commercial products for urine glucose determination were evaluated and compared with a quantitative hexokinase procedure. We examined precision, sensitivity, and analytical recovery of glucose from glucose-supplemented urine samples and comparison of methods, using patients' samples. Only "Chemstrip uG" (Bio-Dyna...
journal_title:Clinical chemistry
pub_type: 杂志文章
doi:
更新日期:1982-10-01 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:BACKGROUND:There is extended urinary excretion of Δ(9)-tetrahydrocannabinol (THC), 11-hydroxy-THC (11-OH-THC), and 11-nor-9-carboxy-THC (THCCOOH) in abstinent frequent cannabis smokers. We characterized THC, 11-OH-THC, THCCOOH, cannabidiol, cannabinol, THC-glucuronide, and THCCOOH-glucuronide disposition in urine of fr...
journal_title:Clinical chemistry
pub_type: 临床试验,杂志文章
doi:10.1373/clinchem.2013.214106
更新日期:2014-02-01 00:00:00
abstract:BACKGROUND:Cyclosporin A (CsA) is commonly measured by immunoassay techniques that have a limited analytical range. The consequence of this is that low CsA concentrations that may be clinically significant are difficult to measure and that high concentrations require sample dilution, which introduces error and increase...
journal_title:Clinical chemistry
pub_type: 杂志文章
doi:
更新日期:2002-01-01 00:00:00
abstract::Each of 65 laboratories analyzed 10 whole-blood samples for erythrocyte protoporphyrin by one or more of several analytical procedures. These procedures were of two types: (a) extraction of protoporphyrin from the erythrocytes into ethyl acetate/acetic acid, re-extraction into hydrochloric acid, and fluorometric measu...
journal_title:Clinical chemistry
pub_type: 杂志文章
doi:
更新日期:1978-12-01 00:00:00
abstract:BACKGROUND:Formalin-fixed paraffin-embedded (FFPE) tumor material represents a valuable resource for the analysis of RNA-based biomarkers, both in research laboratories and in routine clinical testing. A robust and automated RNA-extraction method with a high sample throughput is required. METHODS:We evaluated extracti...
journal_title:Clinical chemistry
pub_type: 杂志文章
doi:10.1373/clinchem.2008.122572
更新日期:2009-09-01 00:00:00
abstract::We used gas chromatography-mass spectrometry to analyze serum specimens from a patient whose metabolic ketoacidosis resulted from sniffing a toluene-containing substance; we also analyzed a sample of the abused substance itself and a serum specimen from a normal subject. The blood samples from the patient showed abnor...
journal_title:Clinical chemistry
pub_type: 杂志文章
doi:
更新日期:1988-12-01 00:00:00
abstract::We evaluated a new EMIT II monoclonal amphetamine/methamphetamine assay for screening human urine by comparing it with the EMIT d.a.u. monoclonal amphetamine/methamphetamine assay and a fluorescence polarization assay. The EMIT II assay has a cutoff of 1 mg/L d-methamphetamine. The EMIT II and EMIT d.a.u. assays were ...
journal_title:Clinical chemistry
pub_type: 杂志文章
doi:
更新日期:1993-01-01 00:00:00
abstract::We recently proposed a quantitative PCR procedure for the absolute measurement of c-erbB-2 oncogene amplification, based on the simultaneous polymerase chain reaction (PCR) amplification of the target gene and of a competitor DNA molecule acting as internal standard. To increase the number of assayable oncogenes and t...
journal_title:Clinical chemistry
pub_type: 杂志文章
doi:
更新日期:1995-06-01 00:00:00
abstract::We used a modification of the polymerase chain reaction (PCR), involving two pairs of oligonucleotide primers, to detect a mutation in the low-density lipoprotein (LDL) receptor gene, commonly occurring among patients with familial hypercholesterolemia (FH) in Finland. This mutation, called FH-Helsinki, involves a lar...
journal_title:Clinical chemistry
pub_type: 杂志文章
doi:
更新日期:1990-06-01 00:00:00