Abstract:
:We describe an improved "high-pressure" liquid-chromatographic assay for simultaneous determination in serum of the five major antiepileptic drugs (ethosuximide, primidone, phenobarbital, phenytoin, and carbamazepine) and N-desmethylmethsuximide (the compound that must be quantitated for therapeutic drug monitoring of the antiepileptic drug methsuximide). Serum protein is precipitated with an acetone solution containing 5-ethyl-5-(p-methylphenyl)barbituric acid as the internal standard. The centrifuged supernate is injected onto the chromatographic column. Drugs and internal standard are eluted at 30 degrees C with mobile phase containing acetonitrile/methanol/phosphate buffer (17/28/55 by vol) at a flow rate of 0.7 mL/min, monitored at 195 nm. Analysis time is about 20 min. Quantitation is by measurement of peak areas. Analytical and absolute recoveries varied from 95 to 104%. Within-day coefficients of variation ranged from 1.6 to 5.4%, between-day CVs from 0.0 to 3.4% in subtherapeutic, therapeutic, and toxic samples. Resolution of therapeutic concentrations of all six drugs was complete. As yet, we have found no drug or drug metabolite that interferes.
journal_name
Clin Chemjournal_title
Clinical chemistryauthors
Szabo GK,Browne TRsubject
Has Abstractpub_date
1982-01-01 00:00:00pages
100-4issue
1eissn
0009-9147issn
1530-8561journal_volume
28pub_type
杂志文章abstract::In this new method for determining urinary protein, the reaction is complete within 10 min at 37 degrees C. This method is applicable to automated as well as manual measurements. Protein concentration and absorbance at 600 nm are linearly related throughout a wide range of concentrations, 10 to 16 000 mg/L. However, t...
journal_title:Clinical chemistry
pub_type: 杂志文章
doi:
更新日期:1986-08-01 00:00:00
abstract:BACKGROUND:Galectin-3 has emerged as a potential useful novel biomarker for heart failure and cardiovascular disease (CVD). However, it remains unclear whether galectin-3 is associated with recurrent cardiovascular events during long-term follow-up of patients with stable coronary heart disease (CHD) after adjustment f...
journal_title:Clinical chemistry
pub_type: 杂志文章
doi:10.1373/clinchem.2016.257550
更新日期:2016-10-01 00:00:00
abstract:BACKGROUND:Previous methods to measure glycohemoglobin (GHb) have been time-consuming or imprecise; we therefore developed a new enzymatic assay for GHb. METHODS:Blood cells were first hemolyzed, and hemoglobin was digested with protease to yield fructosyl amino acid. Fructosyl amino acid oxidase acts on the fructosyl...
journal_title:Clinical chemistry
pub_type: 杂志文章
doi:10.1373/49.2.269
更新日期:2003-02-01 00:00:00
abstract::We have developed a fully enzymatic method to measure 1,5 anhydro-D-glucitol (1,5-AG) in serum through use of pyranose oxidase (PROD: EC 1.1.3.10), glucokinase (EC 2.7.1.2), and an ATP-regenerating system. In a previous report (Clin Chem 1989;35:2039-43) the glucose interfering with the measurement of 1,5-AG was remov...
journal_title:Clinical chemistry
pub_type: 杂志文章
doi:
更新日期:1994-11-01 00:00:00
abstract::This new assay procedure for diaphorase eliminates problems of high blank rates and nonlinear kinetics associated with other methods. The dye thiazolyl blue tetrazolium bromide is reduced in the presence of NADH and diaphorase to yield a colored formazan, which as maximum absorbance at 560 nm. ...
journal_title:Clinical chemistry
pub_type: 杂志文章
doi:
更新日期:1979-12-01 00:00:00
abstract::We describe a sensitive beta-endorphin (beta-EP) radioimmunoassay specific for beta-EP 1-31 applied to human ventricular and lumbar cerebrospinal fluid (CSF). Specificity was documented by reversed-phase HPLC of CSF pools. Simultaneous ventricular and lumbar CSF samples from 13 patients suspected of having normal-pres...
journal_title:Clinical chemistry
pub_type: 杂志文章
doi:
更新日期:1992-06-01 00:00:00
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 flu...
journal_title:Clinical chemistry
pub_type: 杂志文章
doi:
更新日期:1975-01-01 00:00:00
abstract::We describe a method for measuring urinary oxalate and citrate with capillary electrophoresis (CE) and indirect ultraviolet absorbance detection. Sample preparation is minimal, requiring an acidification, brief centrifugation, and dilution. The method is rapid, with oxalate and citrate having mean migration times of 4...
journal_title:Clinical chemistry
pub_type: 杂志文章
doi:
更新日期:1995-09-01 00:00:00
abstract:BACKGROUND:SELDI-TOF mass spectrometry (MS) is a high-throughput proteomic approach with potential for identifying novel forms of serum biomarkers of arthritis. METHODS:We used SELDI-TOF MS to analyze serum samples from patients with various forms of inflammatory arthritis. Several protein profiles were collected on d...
journal_title:Clinical chemistry
pub_type: 杂志文章
doi:10.1373/clinchem.2007.099549
更新日期:2008-06-01 00:00:00
abstract::We compared three current methods (immunoinhibition, "Isomune-CK" immunoprecipitation, and the Tandem-E CKMB II immunoenzymometric assay) for determination of creatine kinase (CK; EC 2.7.3.2) isoenzyme MB in serum. Although results inter-correlated well, the immunoinhibition assay gave higher activity values. Atypical...
journal_title:Clinical chemistry
pub_type: 杂志文章
doi:
更新日期:1990-01-01 00:00:00
abstract::Patients' sera were analyzed for carbamazepine and ethosuximide by enzyme immunoassay (x) and gas chromatography (y), and the results were compared. The correlation coefficients were: for carbamazepine, x vs. y 0.94 (n = 93); for ethosuximide, x vs. y 0.99 (n = 30). These results suggest that the two methods could be ...
journal_title:Clinical chemistry
pub_type: 杂志文章
doi:
更新日期:1977-09-01 00:00:00
abstract:BACKGROUND:The alteration of the bone microenvironment as a consequence of skeletal metastases is poorly understood. The aim of this study was to search for patterns of bone markers in relation to primary tumor type, bone pain, and number of sites involved in patients with bone metastases. METHODS:We studied 323 patie...
journal_title:Clinical chemistry
pub_type: 临床试验,杂志文章
doi:
更新日期:1999-08-01 00:00:00
abstract::We have explored the method of Rapoport et al. (J Clin Endocrinol Metab 1984;58:332-8) for the bioassay of thyroid-stimulating immunoglobulin (TSI) in cultured human thyroid cells, to optimize the assay and to evaluate its utility in clinical diagnosis and management of patients with autoimmune thyroid disease. Here w...
journal_title:Clinical chemistry
pub_type: 杂志文章
doi:
更新日期:1988-02-01 00:00:00
abstract::The precision of estimates of the sensitivity of diagnostic tests is evaluated. "Sensitivity" is defined as the fraction of diseased subjects with test values exceeding the 0.975-fractile of the distribution of control values. An estimate of the sensitivity is subject to sample variation because of variation of both c...
journal_title:Clinical chemistry
pub_type: 杂志文章
doi:
更新日期:1985-04-01 00:00:00
abstract:BACKGROUND:The ratio of plasma aldosterone concentration to plasma renin activity (PRA) is considered the screening test of choice for primary aldosteronism. Uncertainty exists, however, regarding its diagnostic accuracy and the effects of antihypertensive drugs and dietary sodium balance on test characteristics. METH...
journal_title:Clinical chemistry
pub_type: 临床试验,杂志文章
doi:10.1373/clinchem.2004.041780
更新日期:2005-02-01 00:00:00
abstract:BACKGROUND:An accelerated stability model based on the Arrhenius Equation can be used to estimate stability of diagnostic reagents. Here we review 3 examples in which the model does not accurately predict the stability of diagnostic reagents. METHODS:We prepared several pilot lots of quality controls materials contain...
journal_title:Clinical chemistry
pub_type: 杂志文章
doi:10.1093/clinchem/hvaa282
更新日期:2020-12-04 00:00:00
abstract::We describe a convenient, economical procedure for measuring uroporphyrinogen I synthase (EC 4.3 1.8) activity in erythrocytes, the results of which can be used to diagnose acute intermittent porphyria, in either its latent or acute stage. By limiting the test reaction sequence to the conversion of porphobilinogen to ...
journal_title:Clinical chemistry
pub_type: 杂志文章
doi:
更新日期:1980-07-01 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
abstract:BACKGROUND:Multiple genes that are associated with the risk of developing diabetes or the risk of diabetes complications have been identified by candidate gene analysis and genomewide scanning. These molecular markers, together with clinical data and findings from proteomics, metabolomics, pharmacogenetics, and other m...
journal_title:Clinical chemistry
pub_type: 杂志文章,评审
doi:10.1373/clinchem.2010.156901
更新日期:2011-02-01 00:00:00
abstract:BACKGROUND:Neuroblastoma is the most common extracranial malignant solid tumor in children under 5 years and is characterized by a wide clinical and biological heterogeneity, from spontaneously regressive forms to cancers with a rapid and fatal progression. MYCN oncogene amplification is considered the most important p...
journal_title:Clinical chemistry
pub_type: 杂志文章
doi:
更新日期:1999-11-01 00:00:00
abstract:BACKGROUND:We explored the utility of multiplexed temperature gradient capillary electrophoresis (TGCE) as a screening tool for identifying genetic changes in the human mitochondrial genome. We examined changes in mitochondrial DNA (mtDNA) in nonmelanoma skin cancers (NMSCs), using TGCE to resolve genetic differences c...
journal_title:Clinical chemistry
pub_type: 杂志文章
doi:10.1373/clinchem.2004.040311
更新日期:2005-02-01 00:00:00
abstract::We describe a single-cuvette enzyme-linked immunosorbent assay (ELISA) based on enzymic rate kinetics. This kinetic assay can yield linear quantitative data on immunoglobin concentrations. Optimum assay conditions, component concentrations, reaction intervals, and pH are described. Assay linearity and sensitivity are ...
journal_title:Clinical chemistry
pub_type: 杂志文章
doi:
更新日期:1980-08-01 00:00:00
abstract::Extensive data implicate cholesterol in the atherosclerotic process responsible for coronary disease. Of the atherosclerotic disease outcomes, serum cholesterol is most strongly related to coronary disease. A significant relationship of serum cholesterol to all clinical manifestations of coronary heart disease has bee...
journal_title:Clinical chemistry
pub_type: 杂志文章,评审
doi:
更新日期:1988-01-01 00:00:00
abstract::We measured glucocorticoid receptors (GR) in mononuclear leukocytes (MNL) isolated from peripheral blood of 145 apparently healthy volunteers (86 men and 59 women). An age-related decrease in the number of GR was suggested between subjects younger than 20 years and elderly subjects; there was no apparent seasonal vari...
journal_title:Clinical chemistry
pub_type: 杂志文章
doi:
更新日期:1991-10-01 00:00:00
abstract::Several factors can limit the use of therapeutic drug monitoring (TDM) for cancer chemotherapeutic agents, including poorly defined concentration-effect relationships for many antineoplastic agents. This is further complicated by cancer being a highly heterogeneous group of diseases, each of which may have a unique co...
journal_title:Clinical chemistry
pub_type: 杂志文章
doi:
更新日期:1998-02-01 00:00:00
abstract::We describe the sensitive and precise determination 5-hydroxytryptophan in plasma from patients treated with this compound. The method is based on solvent extraction of plasma, high-performance liquid chromatography and continuous fluorometric detection after reaction with phthaldialdehyde in strong acid. The combined...
journal_title:Clinical chemistry
pub_type: 杂志文章
doi:
更新日期:1978-02-01 00:00:00
abstract::We tested a new amylase reagent involving chromogenic substrates (Pantrak, Calbiochem-Behring) for precision, dynamic range, and susceptibility to potential interferences. Two p-nitrophenyl-alpha-maltaosides are used as substrates, which amylase cleaves to shorter-chain p-nitrophenyl maltaosides, the latter then yield...
journal_title:Clinical chemistry
pub_type: 杂志文章
doi:
更新日期:1982-04-01 00:00:00
abstract::Synovial fluid samples were collected from 45 patients with rheumatoid arthritis, spondylarthropathy, or osteoarthritis, to study their content of elastase (EC 3.4.21.37) and of cysteine proteinases (EC 3.4.22.1, 3.4.22.15). We measured both elastase complexed with alpha 1-proteinase inhibitor and elastase activity to...
journal_title:Clinical chemistry
pub_type: 杂志文章
doi:
更新日期:1992-09-01 00:00:00
abstract::Patients' urines gave an unexpectedly high percentage of false-negative results for erythrocytes on a reagent strip, even when the test field for ascorbic acid indicated that none of this substance was present to inhibit the test reaction. By adding known amounts of erythrocytes to normal urines, we found that this ph...
journal_title:Clinical chemistry
pub_type: 杂志文章
doi:
更新日期:1984-11-01 00:00:00
abstract::We describe a sensitive, simple, and rapid two-site immunoenzymometric assay for thyrotropin in dried blood samples on filter paper, for use in screening for neonatal primary hypothyroidism. In this method, two dried-blood spots of 3 mm diameter (equivalent to about 5.4 microliter of blood) are incubated overnight wit...
journal_title:Clinical chemistry
pub_type: 杂志文章
doi:
更新日期:1981-08-01 00:00:00