Abstract：
:I describe a gas-chromatographic procedure involving a nitrogen detector for "free" (or "unbound") phenytoin in the concentration range 0.2-4.0 mg/L in ultrafiltrates of plasma. The CV (n = 10) for the assay was 2.9% for a 0.49 mg/L concentration, 1.5% for 2.02 mg/L. The sensitivity was 0.05 mg/L. The ultrafiltration process ("Ultra-Free" filters) used to separate the free phenytoin fraction from the bound fraction was tested. The mean of and CV for free phenytoin concentrations measured in eight replicate serum filtrates were 0.68 mg/L and 15%; for eight replicate plasma filtrates the values were 0.42 mg/L and 2.9%. Thus serum is not suitable for this procedure. Storage of plasma before filtration under a wide variety of times and temperatures has an insignificant effect upon the filtration process. Some evidence was found of occasional protein "leakage" through the filters.
journal_name
Clin Chemjournal_title
Clinical chemistryauthors
Joern WAsubject
Has Abstractpub_date
1981-03-01 00:00:00pages
417-21issue
3eissn
0009-9147issn
1530-8561journal_volume
27pub_type
杂志文章abstract：:Intra- and interindividual components of biological variation have been determined for total thyroxin (TT4), free thyroxin (FT4), total triiodothyronine (TT3), free triiodothyronine (FT3), and thyrotropin (TSH). Calculated analytical goals (CV, %) for the precision required for optimal patient care are: TT4 less than ...
journal_title：Clinical chemistry
pub_type： 杂志文章
doi：
更新日期：1986-06-01 00:00:00
abstract：:This method for determining aluminum in human serum involves electrothermal atomic absorption spectrophotometry. A longer drying time allows less pre-dilution of the sample, and the method also includes a flush cycle after atomization. Standard-addition methodology is used to eliminate matrix effects and the need for ...
journal_title：Clinical chemistry
pub_type： 杂志文章
doi：
更新日期：1983-06-01 00:00:00
abstract：BACKGROUND:The hepatocyte-derived acute-phase reactant C-reactive protein (CRP) has been the subject of intense research over the last 2 decades for its possible role in the pathogenesis of cardiovascular diseases. This research has spawned interest in the use of the blood concentration of CRP for predicting a first co...
journal_title：Clinical chemistry
pub_type： 杂志文章,评审
doi：10.1373/clinchem.2008.115923
更新日期：2009-02-01 00:00:00
abstract：:In this simple, quick procedure for determining copper in human serum and urine, the serum and urine specimens were analyzed directly after dilution with a solution of HNO3 and Triton X-100, 1 mL/L each. We calibrated with aqueous standards for quantitation in Zeeman background atomic absorption spectrometry. By modif...
journal_title：Clinical chemistry
pub_type： 杂志文章
doi：
更新日期：1993-09-01 00:00:00
abstract：BACKGROUND:Studies of the effects of tobacco smoke often rely on reported exposure to cigarette smoke, a measure that is subject to bias. We describe here the relationship between parental smoking exposure as assessed by urinary cotinine excretion and lung function in children with asthma. METHODS:We studied 90 childr...
journal_title：Clinical chemistry
pub_type： 临床试验,杂志文章
doi：
更新日期：1999-04-01 00:00:00
abstract：BACKGROUND:Δ(9)-Tetrahydrocannabinol (THC), 11-nor-9-carboxy-THC (THCCOOH), and cannabinol (CBN) were measured in breath following controlled cannabis smoking to characterize the time course and windows of detection of breath cannabinoids. METHODS:Exhaled breath was collected from chronic (≥4 times per week) and occas...
journal_title：Clinical chemistry
pub_type： 杂志文章
doi：10.1373/clinchem.2013.207407
更新日期：2013-12-01 00:00:00
abstract：:We describe a ratio gas-chromatographic method for determination of cortisol production rate by measuring the isotope dilution of urinary cortisol metabolites. The method was calibrated by analyzing [3H]tetrahydrocortisol and [3H]tetrahydrocortisone of known specific activities. Results are reasonably well reproducibl...
journal_title：Clinical chemistry
pub_type： 杂志文章
doi：
更新日期：1977-03-01 00:00:00
abstract：BACKGROUND:A sensitive gas chromatography-negative ion chemical ionization mass spectrometry (GC/MS-NICI) method was developed and validated for the measurement of Delta(9)-tetrahydrocannabinol (THC) in human sweat patches. METHODS:THC-d(0) and THC-d(3) were added to worn blank sweat patches (PharmChek; PharmChem Inco...
journal_title：Clinical chemistry
pub_type： 临床试验,杂志文章
doi：10.1373/clinchem.2004.034868
更新日期：2004-11-01 00:00:00
abstract：:After extraction of the sample (on filter paper) in the counting vial, cortisol is assayed by adding 50 microL of horse serum containing tritiated cortisol, and 2 mL of toluene scintillator, shaking for 20 min, and counting the radioactivity in a liquid-scintillation counter at ambient temperature. The method can be a...
journal_title：Clinical chemistry
pub_type： 杂志文章
doi：
更新日期：1987-07-01 00:00:00
abstract：BACKGROUND:Although minimum regulatory standards exist for determining QC testing frequency, decisions regarding when and how to run QC samples are not standardized. Most QC testing strategies test control samples at fixed time intervals, often placing the samples in the same position on an instrument during subsequent...
journal_title：Clinical chemistry
pub_type： 杂志文章
doi：10.1373/clinchem.2006.083311
更新日期：2007-04-01 00:00:00
abstract：:We report results for adjusted ionized calcium (at pH 7.4) and actual ionized calcium (at actual pH) in capillary blood from 183 patients with disorders of calcium metabolism (primary hyperparathyroidism, secondary hyperparathyroidism of malabsorption, primary hypoparathyroidism, Paget's disease, acromegaly, hypercalc...
journal_title：Clinical chemistry
pub_type： 杂志文章
doi：
更新日期：1990-03-01 00:00:00
abstract：:We measured the concentration of erythrocyte protoporphyrin in 43 blood samples by two fluorometric methods. In the indirect method, protoporphyrin was extracted from blood and the fluorescence of the free acid in the extract was determined with a filter-fluorometer. These results were compared with results of direct ...
journal_title：Clinical chemistry
pub_type： 杂志文章
doi：
更新日期：1978-09-01 00:00:00
abstract：:Using results from patients, we studied several methods for long-term (years) monitoring of the analytical stability of various chemistry tests. For each test, we obtained on a bimonthly basis histograms of > or = 200 to approximately 2000 data points and determined the median, mean, and mean of those data points in t...
journal_title：Clinical chemistry
pub_type： 杂志文章
doi：
更新日期：1996-06-01 00:00:00
abstract：:This case demonstrates the importance of monitoring theophylline concentrations in serum during therapy with this drug. The commonly used body-weight-derived guidelines for therapeutic dose are not adequate and do not preclude the necessity for such monitoring. The ultraviolet spectrophotometric methods available for ...
journal_title：Clinical chemistry
pub_type： 杂志文章
doi：
更新日期：1978-09-01 00:00:00
abstract：:Urinary excretion of orally administered lactulose is used as an index of intestinal permeability. We have developed a simple thin-layer chromatographic technique for measuring lactulose in urine, using silica gel 60 plates and a propanol-borate solvent system. Lactulose concentrations as low as 62.5 mg/L can be detec...
journal_title：Clinical chemistry
pub_type： 杂志文章
doi：
更新日期：1987-07-01 00:00:00
abstract：BACKGROUND:Myeloperoxidase (MPO) is a biomarker of inflammation and oxidative stress produced by neutrophils, monocytes, and endothelial cells. Concentrations of MPO predict mortality in patients with chronic heart failure. This study sought to investigate the diagnostic accuracy and prognostic value of MPO in patients...
journal_title：Clinical chemistry
pub_type： 杂志文章
doi：10.1373/clinchem.2009.142257
更新日期：2010-06-01 00:00:00
abstract：BACKGROUND:At concentrations <500 microg/L, serum alpha-fetoprotein (AFP) has low specificity in the diagnosis of hepatocellular carcinoma (HCC), but monosialylated AFP (msAFP) is more specific for HCC. We describe two strategies for quantitative analysis of msAFP and explore their diagnostic accuracy in cases of HCC w...
journal_title：Clinical chemistry
pub_type： 杂志文章
doi：
更新日期：2002-07-01 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：:Various laboratories have reported endogenous digoxin-like immunoreactive factor(s) (DLIF) in blood from patients in renal failure or liver failure, from newborn infants, and from third-trimester pregnant women. Similar immunoreactivity has been detected in amniotic fluid, in cord blood, and in urine and serum from no...
journal_title：Clinical chemistry
pub_type： 杂志文章,评审
doi：
更新日期：1985-09-01 00:00:00
abstract：:Ethchlorvynol is a commonly abused sedative hypnotic. I report here a seven-day study of serum ethchlorvynol concentrations in a patient who had received an extreme overdose. These concentrations were correlated with the patient's response to stimuli. Serum ethchlorvynol concentrations were logarithmically related to ...
journal_title：Clinical chemistry
pub_type： 杂志文章
doi：
更新日期：1975-06-01 00:00:00
abstract：:We can detect the beta-globin gene sickle cell mutation by using an assay based on the ligase chain reaction. The simultaneous amplification of the human growth hormone gene in the same reaction serves as a control for the amount of template DNA or amplification efficiency. Ligation products, which are biotinylated at...
journal_title：Clinical chemistry
pub_type： 杂志文章
doi：
更新日期：1997-01-01 00:00:00
abstract：:We describe a procedure for determining thiocyanate in plasma with a Technicon AutoAnalyzer I, modified with a 50-mm tubular flow cell to increase the sensitivity of thiocyanate detection. The procedure is suitable for distinguishing cigarette smokers from non-smokers, the mean for smokers being 151 (SD 43) micromol/L...
journal_title：Clinical chemistry
pub_type： 杂志文章
doi：
更新日期：1980-03-01 00:00:00
abstract：:We describe the development of a stable reference material for prostatic acid phosphatase, derived from human prostatic tissue and human seminal fluid. The enzyme was purified by an L-tartramic acid affinity-chromatography technique. Two-dimensional electrophoresis revealed essentially no contaminating proteins, and s...
journal_title：Clinical chemistry
pub_type： 杂志文章
doi：
更新日期：1984-08-01 00:00:00
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 ...
journal_title：Clinical chemistry
pub_type： 杂志文章
doi：
更新日期：1979-07-01 00:00:00
abstract：BACKGROUND:We describe a simple tetra-primer amplification refractory mutation system PCR (T-ARMS-PCR) for detecting MUTYH mutations, which are associated with colorectal adenomas and colorectal cancer. METHODS:We designed specific T-ARMS-PCR assays for 6 mutations (Y165C, G382D, 1395_7delGGA, Y90X, 1103delC, and R231...
journal_title：Clinical chemistry
pub_type： 杂志文章
doi：10.1373/clinchem.2005.060137
更新日期：2006-04-01 00:00:00
abstract：:A new instrument has been developed that is similar in design and concept to the GeMSAEC centrifugal analyzer (Oak Ridge National Laboratory) except that electrochemical detection is used rather than optical detection. The present version has eight channels, each with its own detector. Problems of speed control and sa...
journal_title：Clinical chemistry
pub_type： 杂志文章
doi：
更新日期：1982-09-01 00:00:00
abstract：BACKGROUND:Until recently, clinical laboratories have monitored hemophilia treatment by measuring coagulation factors before/after infusion of human-derived or recombinant factors. Substantial changes are expected in the near future based on new therapeutic approaches that have been or are being developed. CONTENT:Hem...
journal_title：Clinical chemistry
pub_type： 杂志文章,评审
doi：10.1373/clinchem.2017.284356
更新日期：2019-02-01 00:00:00
abstract：:A new, highly sensitive immunoradiometric thyrotropin (TSH) assay involving solid-phase-coupled monoclonal antibodies (Boots-Celltech Sucrosep IRMA-TSH) has been evaluated in a wide variety of patients with thyroidal and nonthyroidal illnesses and the results compared with those obtained by conventional diagnostic TSH...
journal_title：Clinical chemistry
pub_type： 杂志文章
doi：
更新日期：1986-03-01 00:00:00
abstract：:If there were enzymatically inactive B subunits in a solution containing lactate dehydrogenase (LD) B4 prepared from the hemolysates of heterozygous individuals with LD-B subunit deficiency, the inactive subunits would compete with normal subunits for antibodies to the B4 subunit. Using the activity of normal LD-B4 as...
journal_title：Clinical chemistry
pub_type： 杂志文章
doi：
更新日期：1986-01-01 00:00:00
abstract：:The poly-T tract in intron 8 of the cystic fibrosis conductance transmembrane regulator (CFTR) gene exists in three variants, 5T, 7T, and 9T. The 7T and 9T variants generate a predominantly normal transcript, whereas the 5T variant engenders an anomalous product. The analysis of the poly-T tract is assuming increasing...
journal_title：Clinical chemistry
pub_type： 杂志文章
doi：
更新日期：1998-05-01 00:00:00
