Abstract：
:In this assay of tamoxifen and four metabolites in human serum, the serum samples are deproteinized with an equal volume of acetonitrile, then injected into a small (0.21 X 2 cm) precolumn packed with 5-micron-diameter octadecylsilane (ODS) particles. The samples are concentrated on-column by equilibrating the column with an equivolume solution of water and acetonitrile containing 3 mmol of acetic acid and 2 mmol of diethylamine per liter. The drugs are then directed into an analytical ODS column (0.21 X 10 cm) by changing the mobile phase followed by column switching. The primary alcohol of tamoxifen ("metabolite Y"), 4-hydroxytamoxifen ("metabolite B"), tamoxifen, N-desdimethyltamoxifen ("metabolite Z"), N-desmethyltamoxifen ("metabolite X"), and 4-methoxytamoxifen (internal standard) are eluted in this order at a flow rate of 0.3 mL/min with a mobile phase of acetonitrile/water (91/9 by vol) at low ionic strength (1 mmol of acetic acid and 0.67 mmol of diethylamine per liter) and detected by post-column fluorescence activation by passage through a capillary quartz tube exposed to ultraviolet light. Analytical recovery was close to 100%. Within-day precision corresponded to a CV of 1-5% at serum concentrations of tamoxifen or metabolites greater than 10 micrograms/L; the detection limit of the assay for these compounds was about 1 microgram/L. This fully automated assay has the advantage of simple sample processing, high sample output, low solvent consumption, high analytical recovery of tamoxifen and four metabolites in serum, and determination of all these compounds plus an internal standard in a single run.
journal_name
Clin Chemjournal_title
Clinical chemistryauthors
Lien EA,Ueland PM,Solheim E,Kvinnsland Ssubject
Has Abstractpub_date
1987-09-01 00:00:00pages
1608-14issue
9eissn
0009-9147issn
1530-8561journal_volume
33pub_type
杂志文章abstract：:The S-peptide and S-protein fragments of ribonuclease S (RNase S, no EC no. assigned) have been immobilized onto separate Sepharose gels via a "leash" of polycytidylic acid substrate. Each of these gels releases its RNase fragment when treated with the complementary enzyme fragment or with RNase A (EC 3.1.27.5), and t...
journal_title：Clinical chemistry
pub_type： 杂志文章
doi：
更新日期：1986-09-01 00:00:00
abstract：:A region consisting of 19 clinical laboratories harmonized their calibration of seven common enzymes by using fresh patient-pool sera. One of the laboratories was chosen to act as Regional Reference Laboratory (RRL). This laboratory used internationally accepted (mostly IFCC) methods at 37 degrees C, with an intralabo...
journal_title：Clinical chemistry
pub_type： 杂志文章,多中心研究
doi：
更新日期：1998-03-01 00:00:00
abstract：BACKGROUND:The analytical and clinical performance of homogeneous LDL-cholesterol assays has been reported, but their reactions with subfractions of LDL and VLDL have not been described in detail. METHODS:We evaluated reaction selectivity of two homogeneous LDL-cholesterol assays, LDLk (Kyowa Medex) and LDLd (Daiichi ...
journal_title：Clinical chemistry
pub_type： 杂志文章
doi：
更新日期：2002-11-01 00:00:00
abstract：:We describe a novel assay for measuring glycohemoglobin directly from anticoagulated whole blood with the Abbott IMx analyzer. The glycohemoglobin is labeled with a soluble polyanionic affinity reagent and the anionic complex is then captured with a cationic solid-phase matrix. Glycohemoglobin is quantified by measuri...
journal_title：Clinical chemistry
pub_type： 杂志文章
doi：
更新日期：1993-10-01 00:00:00
abstract：:We describe a rapid, reliable radioimmunoassay for unconjugated estriol in plasma. Polyethylene glycol (Carbowax 6000) is used to separate antibody-bound and free steroid. The assay is sensitive (25 pg for standards), precise, and accurate. At high and low concentrations of estriol, intra-assay coefficients of variati...
journal_title：Clinical chemistry
pub_type： 杂志文章
doi：
更新日期：1976-03-01 00:00:00
abstract：:Concentrations of triglycerides are increased and concentrations of high-density lipoprotein (HDL) cholesterol are low in women with hyperandrogenism. These alterations could be related to excessive androgen or estrogen, to hyperinsulinism, or to a combination of these abnormalities. We examined their independent infl...
journal_title：Clinical chemistry
pub_type： 杂志文章
doi：
更新日期：1990-02-01 00:00:00
abstract：BACKGROUND:Vascular smooth muscle cells (SMCs) migrate from the arterial media to the intima in the progression of atherosclerosis, and dysfunction of SMCs leads to enhanced atherogenesis. A soluble form of the LDL receptor relative with 11 ligand-binding repeats (sLR11) is produced by the intimal SMCs, and the circula...
journal_title：Clinical chemistry
pub_type： 杂志文章
doi：10.1373/clinchem.2009.127027
更新日期：2009-10-01 00:00:00
abstract：:We describe a simple method in which a water-soluble mixture of triocatanoin and a surfactant, "Triton X-114," are used in preparing solutions of triglycerides (triacylglycerols) in either human serum, solutions of albumin, or water. Analytical recovery added triglyceride was quantitative by two methods. The addition ...
journal_title：Clinical chemistry
pub_type： 杂志文章
doi：
更新日期：1976-08-01 00:00:00
abstract：:Serum concentrations of apolipoprotein (apo) B and apo A-I were measured from 1985-1996 in a Swedish population sample of 83 112 males and 64 464 females, ages <20 to >80 years, using an automated immunoturbidimetric method calibrated against fresh pools of human serum and commercial calibrators. All values were recal...
journal_title：Clinical chemistry
pub_type： 杂志文章
doi：
更新日期：1998-08-01 00:00:00
abstract：:We evaluated a method for quantifying high-density lipoprotein cholesterol in plasma, based on electrophoretic migration of the prestained (with Sudan Black III) sample through a discontinuous polyacrylamide++ gel and densitometric integration of the stain associated with each class of lipoprotein. With this method, o...
journal_title：Clinical chemistry
pub_type： 杂志文章
doi：
更新日期：1985-11-01 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：BACKGROUND:Measurement of plasma renin is important for the clinical assessment of hypertensive patients. The most common methods for measuring plasma renin are the plasma renin activity (PRA) assay and the renin immunoassay. The clinical application of renin inhibitor therapy has thrown into focus the differences in i...
journal_title：Clinical chemistry
pub_type： 杂志文章,评审
doi：10.1373/clinchem.2008.118000
更新日期：2009-05-01 00:00:00
abstract：BACKGROUND:Intravenous and subcutaneous microdialysis was performed to compare the free concentrations and pharmacokinetics of L-3, 4-dihyroxyphenylalanine (L-dopa) in blood and tissue in healthy subjects and in patients with Parkinson disease. METHODS:Nine healthy volunteers and 10 patients with Parkinson disease, st...
journal_title：Clinical chemistry
pub_type： 临床试验,杂志文章
doi：
更新日期：1999-10-01 00:00:00
abstract：:The metabolism of the synthetic substrate 7-ethoxyresorufin is a selective measure of the activity of cytochrome P-448 monooxygenase, the subset of cytochrome P-450-mediated enzymes preferentially induced by polycyclic aromatic hydrocarbons and related compounds. 7-Ethoxycoumarin metabolism, on the other hand, reflect...
journal_title：Clinical chemistry
pub_type： 杂志文章
doi：
更新日期：1981-09-01 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：:A new method (enzyme-ligand immunoassay, ELIA) is described for the estimation of estrogen (ER) and progesterone (PR) receptors in microsamples of human breast cancer tissue. The technique, based on the nonisotopic measurement of receptor-bound estradiol and progesterone, involves three steps: (a) simultaneous saturat...
journal_title：Clinical chemistry
pub_type： 杂志文章
doi：
更新日期：1995-01-01 00:00:00
abstract：:We report here the evaluation of the Abbott TDx assay with a monoclonal antibody for selectively quantifying cyclosporine (CsA) in whole blood. Over the clinically relevant concentration ranges, results with this assay demonstrated within- and between-run CVs of less than 2.5% and 5%, respectively; sensitivity of 25 m...
journal_title：Clinical chemistry
pub_type： 杂志文章
doi：
更新日期：1990-11-01 00:00:00
abstract：:Discrepancies among different methods for assaying human growth hormone have been described in various studies. The two major sources of discordant results are the heterogeneity of the antibodies and the different standardization bases used by the assay manufacturers. We propose standardizing assays with 22-kDa biosyn...
journal_title：Clinical chemistry
pub_type： 杂志文章
doi：
更新日期：1992-10-01 00:00:00
abstract：:Serum folate, pteroylglutamic acid standards, and N-5-methyltetrahydrofolate standards extract differently during sample preparation for radiometric assay. B/B0 values for each material were determined before and after an alkaline extraction procedure. Serum folate most closely resembled N-5-methyltetrahydrofolate sta...
journal_title：Clinical chemistry
pub_type： 杂志文章
doi：
更新日期：1981-04-01 00:00:00
abstract：:A continuous-monitoring method for measuring acid phosphatase activity with alpha-naphthyl phosphate as the substrate was critically evaluated and modified. Using partially purified prostatic acid phosphatase, we show that certain conditions for the assay must be satisfied to ensure linearity. These conditions include...
journal_title：Clinical chemistry
pub_type： 杂志文章
doi：
更新日期：1976-12-01 00:00:00
abstract：:We describe a new liquid-chromatographic method with fluorescence detection for direct simultaneous determination of four urinary sulfate conjugates of 17-oxosteroids (17OS), without use of solvolysis or enzymatic hydrolysis. The 17OS sulfates in urine samples are extracted with benzene as ion pairs in the presence of...
journal_title：Clinical chemistry
pub_type： 杂志文章
doi：
更新日期：1986-05-01 00:00:00
abstract：BACKGROUND:Stability of chemical speciation during sample handling and storage is a prerequisite to obtaining reliable results of trace element speciation analysis. There is no comprehensive information on the stability of common arsenic species, such as inorganic arsenite [As(III)], arsenate [As(V)], monomethylarsonic...
journal_title：Clinical chemistry
pub_type： 杂志文章
doi：
更新日期：1999-11-01 00:00:00
abstract：BACKGROUND:Increased cardiac troponin concentrations in acute coronary syndrome (ACS) identify patients with ongoing cardiomyocyte necrosis who are at increased risk. However, with the use of more precise assays, cardiac troponin increases are commonly noted in other cardiovascular conditions as well. This has generate...
journal_title：Clinical chemistry
pub_type： 杂志文章,评审
doi：10.1373/clinchem.2016.261495
更新日期：2017-01-01 00:00:00
abstract：BACKGROUND:We sought to develop a tandem mass spectrometry assay in which the enzymatic activities of 3 lysosomal enzymes (α-glucosidase, α-galactosidase A, and α-l-iduronidase) could be quantified in dried blood spots by using a single assay buffer. METHODS:A 3-mm dried blood spot punch was incubated in a single assa...
journal_title：Clinical chemistry
pub_type： 杂志文章
doi：10.1373/clinchem.2010.152009
更新日期：2010-12-01 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：:On-line, simultaneous measurement of blood K+, Ca2+, Na+, and pH has been achieved by using a quadruple-function ChemFET (chemical-sensitive field-effect transistor) integrated-circuit sensor. Blood is withdrawn from the subject through an actively heparinized, dual-lumen cannula and passed into a flow-cell containing...
journal_title：Clinical chemistry
pub_type： 杂志文章
doi：
更新日期：1984-01-01 00:00:00
abstract：:We describe a fixed-time, enzymatic, reaction-rate procedure for determining plasma ammonia with a centrifugal analyzer (Rotochem IIA/36; American Instrument Co., silver Spring, MD 20910), with NADPH as cofactor. The reaction is based on that of da Fonseca-Wollheim's modification [J. Clin. Chem. Clin. Biochem. 11, 421...
journal_title：Clinical chemistry
pub_type： 杂志文章
doi：
更新日期：1979-04-01 00:00:00
abstract：BACKGROUND:The 2447 A > T pathogenic variation at codon 816 of exon 17 (D816V) in the KIT gene, occurring in systemic mastocytosis (SM), leads to constitutive activation of tyrosine kinase activity and confers resistance to the tyrosine kinase inhibitor imatinib mesylate. Thus detection of this variation in SM patients...
journal_title：Clinical chemistry
pub_type： 杂志文章
doi：10.1373/clinchem.2006.068205
更新日期：2006-12-01 00:00:00
abstract：:We analyzed pancreatic enzyme data from 508 patients with suspected pancreatitis by neural network analysis, by an Expert multirule generation protocol, and by receiver-operator characteristic (ROC) curve analysis of a single test result. Neural network analysis showed that use of lipase provided the best means for di...
journal_title：Clinical chemistry
pub_type： 杂志文章
doi：
更新日期：1993-09-01 00:00:00
abstract：:We compared the analytical performance of the Kodak Ektachem XR700 assays of iron (Fe) and total iron-binding capacity (TIBC) with that of a conventional ferrozine assay (performed with a Cobas-Bio) and occasionally with that of atomic-absorption spectrometry (AAS). The correlation was modest between Kodak and Cobas-B...
journal_title：Clinical chemistry
pub_type： 杂志文章
doi：
更新日期：1990-10-01 00:00:00
