Abstract：
:Determination of the ratio of testosterone to epitestosterone (T/E) in urine is used to detect testosterone administration in athletes, with a ratio > 6 considered as evidence of an offense. We show that administration of ketoconazole, which inhibits testosterone biosynthesis, may be useful for differentiating between an athlete who is using testosterone and one who naturally gives a ratio > 6. In a control subject pretreated with testosterone, ketoconazole caused the ratio to increase; conversely, it caused a decrease in the ratio in an athlete under investigation. Repeated administration of ketoconazole to two normal men caused a decrease in the ratio due to a large decrease in the urinary excretion rate of testosterone relative to epitestosterone. Stimulation with human chorionic gonadotropin exacerbated the differences in excretion rates. A single administration of ketoconazole to six normal men caused the T/E ratios to decrease significantly within 8 h, a suitable time scale for use in a dynamic test.
journal_name
Clin Chemjournal_title
Clinical chemistryauthors
Kicman AT,Oftebro H,Walker C,Norman N,Cowan DAsubject
Has Abstractpub_date
1993-09-01 00:00:00pages
1798-803issue
9eissn
0009-9147issn
1530-8561journal_volume
39pub_type
杂志文章abstract：:Using a solid-phase monoclonal antibody enzyme immuno-assay, we evaluated in a multicenter study (18 laboratories) the utility of evaluating catalytic activity of human placental alkaline phosphatase (hPLAP, EC 3.1.3.1) in serum as a potential tumor marker. We determined hPLAP in serum samples from 130 patients with o...
journal_title：Clinical chemistry
pub_type： 杂志文章
doi：
更新日期：1988-10-01 00:00:00
abstract：:We have modified the 63Ni radiochemical method of Ho (Anal Biochem 1970;36:105) for determination of free fatty acids (FFA) in plasma. Extracting 1 or 0.1 mL of plasma with Dole's mixture (J Biol Chem 1960;235:2595) and washing the "heptane" layer with two volumes of isopropanol/water/dilute (0.5 mol/L) H2SO4 (25/25/1...
journal_title：Clinical chemistry
pub_type： 杂志文章
doi：
更新日期：1987-01-01 00:00:00
abstract：BACKGROUND:The purpose of this study was to assess the feasibility of infrared (IR) spectroscopy for the simultaneous quantification of serum LDL-cholesterol (LDL-C) and HDL-cholesterol (HDL-C) concentrations. METHODS:Serum samples (n = 90) were obtained. Duplicate aliquots (5 microL) of the serum specimens were dried...
journal_title：Clinical chemistry
pub_type： 杂志文章
doi：
更新日期：2002-03-01 00:00:00
abstract：:We describe a system for detection of leukemia cells involving complement-mediated cytotoxic reaction and an image processing system, consisting of a charge-coupled-device image sensor, an image memory board, a personal computer, and a phase-contrast microscope. Then added to a cell suspension, monoclonal antibody spe...
journal_title：Clinical chemistry
pub_type： 杂志文章
doi：
更新日期：1987-04-01 00:00:00
abstract：:We report a method for the extraction of angiotensin peptides from plasma with a mixture of acetone, 1 mol/L HCl, and water (40/1/5 by vol). The method is highly reproducible for the measurement of angiotensin I and angiotensin II in small sample volumes, with analytical recoveries of about 80% for both peptides. We i...
journal_title：Clinical chemistry
pub_type： 杂志文章
doi：
更新日期：1988-06-01 00:00:00
abstract：:We describe an automated enzymatic procedure for quantifying creatine in erythrocytes. In this assay, after sample clean-up, creatine kinase (CK; EC 2.7.3.2) and pyruvate kinase (EC 2.1.7.40) are used as auxiliary enzymes; lactate dehydrogenase (EC 1.1.1.27) is used in the indicator reaction. CK is also used as the st...
journal_title：Clinical chemistry
pub_type： 杂志文章
doi：
更新日期：1996-02-01 00:00:00
abstract：:We investigated the efficiency, accuracy, and reliability of the ultrafiltration/dipstick methodology commonly used to diagnose myoglobinuria. Twenty-five myoglobin-containing urine specimens were filtered by centrifugation for 15 min at 1500g through a Centricon-30 membrane filter. Both the original specimen and filt...
journal_title：Clinical chemistry
pub_type： 杂志文章
doi：
更新日期：1996-06-01 00:00:00
abstract：:The currently available radioimmunoassays of trypsin measure total immunoreactive trypsin (EC 3.1.1.7), which includes both trypsinogen and alpha 1-protease inhibitor-bound trypsin. Hitherto, the only way to differentiate these two forms of trypsin has been to fractionate them on a gel-filtration column. We describe h...
journal_title：Clinical chemistry
pub_type： 杂志文章
doi：
更新日期：1986-09-01 00:00:00
abstract：BACKGROUND:Associations between dairy intake and body composition and cardiometabolic traits have been inconsistently observed in epidemiological studies, and the causal relationship remains ill-defined. METHODS:We performed Mendelian randomization analysis using an established genetic variant located upstream of the ...
journal_title：Clinical chemistry
pub_type： 杂志文章
doi：10.1373/clinchem.2018.300335
更新日期：2019-06-01 00:00:00
abstract：BACKGROUND:Prediction of cyclosporine (CSA) efficacy and toxicity in individual patients is difficult. There is no practical, biologically relevant, pharmacodynamic measure of CSA effect. A major effect of CSA is to decrease interleukin-2 (IL-2) production; however, measurement of this effect in isolated lymphocytes as...
journal_title：Clinical chemistry
pub_type： 杂志文章
doi：
更新日期：1999-09-01 00:00:00
abstract：:We report a continuous-flow fluorometric method for total urinary estrogens that involves the Kober reaction, with extraction of the reaction product into dichloroethane containing trichloroacetic acid as described by Hahnel and Jones [Clin. Chim. Acta 16, 185 (1967)]. The dichloroethane extraction gives greater stabi...
journal_title：Clinical chemistry
pub_type： 杂志文章
doi：
更新日期：1977-10-01 00:00:00
abstract：BACKGROUND:Quantification of integrated proviral HIV DNA by repetitive-sampling Alu-HIV PCR is a candidate virological tool to monitor the HIV reservoir in patients. However, the experimental procedures and data analysis of the assay are complex and hinder its widespread use. Here, we provide an improved and simplified...
journal_title：Clinical chemistry
pub_type： 杂志文章
doi：10.1373/clinchem.2013.219378
更新日期：2014-06-01 00:00:00
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 s...
journal_title：Clinical chemistry
pub_type： 杂志文章
doi：
更新日期：1996-01-01 00:00:00
abstract：BACKGROUND:Screening for heterozygous sequence changes in PCR products, also known as "mutation scanning", is an important tool for genetic research and clinical applications. Conventional methods require a separation step. METHODS:We evaluated the sensitivity and specificity of homogeneous scanning, using a saturatin...
journal_title：Clinical chemistry
pub_type： 杂志文章
doi：10.1373/clinchem.2003.029751
更新日期：2004-10-01 00:00:00
abstract：:We measured certain enzyme activities (aldolase, aspartate aminotransferase, creatine kinase, and lactate dehydrogenase) and inflammation markers (alpha 1-antitrypsin, C-reactive protein, fibrinogen, and leukocytes) each day for four days in plasma of patients with severe head injury. The univariate prognostic efficie...
journal_title：Clinical chemistry
pub_type： 杂志文章
doi：
更新日期：1983-11-01 00:00:00
abstract：:Kappa Bence Jones proteinuria was found by immunoelectrophoretic techniques in a patient with plasma cell leukemia, who presented with no M-proteins either in serum or urine. However, a significant decrease in normal immunoglobulins was observed. On microscopic examination of kidney sections obtained a autopsy, protei...
journal_title：Clinical chemistry
pub_type： 杂志文章
doi：
更新日期：1975-10-01 00:00:00
abstract：:6-thioguanine (6-TGN) and methyl 6-mercaptopurine nucleotides (Me6-MPNs) are the two major metabolites found in erythrocytes after administration of azathioprine. In an attempt to understand the role of these metabolites in the pharmacologic and toxic activity of thiopurines, we have developed a HPLC method for the si...
journal_title：Clinical chemistry
pub_type： 杂志文章
doi：
更新日期：1998-03-01 00:00:00
abstract：:We present a simple method for subclass typing of IgG paraproteins, with which we have demonstrated a large number of paraproteins that were undetected by conventional immunofixation techniques. The types and distribution of IgG subclass paraproteins were analyzed in 92 human sera in which IgG paraproteins had been de...
journal_title：Clinical chemistry
pub_type： 杂志文章
doi：
更新日期：1995-10-01 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：: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：BACKGROUND:To determine the contribution of laboratory costs to the overall costs of managing hospital patients with different diseases, we studied the costs of laboratory testing overall and in relation to the other costs incurred during hospitalization. METHODS:We used a database developed by the University HealthSy...
journal_title：Clinical chemistry
pub_type： 杂志文章
doi：
更新日期：2000-07-01 00:00:00
abstract：BACKGROUND:Our previously developed assay for detection of the factor V Leiden mutation (G1691A) based on a nucleic acid photo-cross-linking technology used two allele-specific capture probes and six fluorescein-modified signal-generating reporter probes. We wished to improve the sensitivity and performance of the meth...
journal_title：Clinical chemistry
pub_type： 杂志文章
doi：10.1373/clinchem.2003.023556
更新日期：2004-02-01 00:00:00
abstract：BACKGROUND:The association of changes in oxidative and proinflammatory states with vascular function after diet and exercise intervention among obese children has not been previously explored. METHODS:In this 6-week diet and exercise intervention study in 35 obese children, age 12 to 18 years, we evaluated the relatio...
journal_title：Clinical chemistry
pub_type： 临床试验,杂志文章
doi：10.1373/clinchem.2007.089953
更新日期：2008-01-01 00:00:00
abstract：:We evaluated the Kallestad "Quanticoat" cortisol RIA for direct (no extraction) measurement of urinary free cortisol, which requires no solvent extraction. An analytical-recovery study showed a linear regression of y (measured) = 0.65x (added) + 37.5 micrograms/L (Sy.x = 21.4 micrograms/L, r = 0.978, n = 48). Recovery...
journal_title：Clinical chemistry
pub_type： 杂志文章
doi：
更新日期：1989-01-01 00:00:00
abstract：:We compared cotinine, carboxyhemoglobin, and thiocyanate concentrations in blood sampled from 187 cigarette smokers and 181 non-smokers. All three differed significantly between smokers and non-smokers. Cotinine performed best as a test for assessing smoking status, with a sensitivity of 98% as compared with 94% for c...
journal_title：Clinical chemistry
pub_type： 杂志文章
doi：
更新日期：1984-08-01 00:00:00
abstract：:Based on the quantitative determination of creatinine, total protein, albumin, alpha 1-microglobulin, IgG, alpha 2-macroglobulin, and N-acetyl-beta, D-glucosaminidase in urine in combination with a test strip screening, the findings of hematuria, leukocyturia, and proteinuria can be assigned to prerenal, renal, or pos...
journal_title：Clinical chemistry
pub_type： 杂志文章
doi：
更新日期：1996-08-01 00:00:00
abstract：:Diagnosing cobalamin deficiency is often difficult. We investigated the diagnostic strategies that 224 general practitioners used to assess cobalamin status and the criteria on which they based their decisions to supplement patients. From all serum cobalamin analyses carried out at a single laboratory during 1993, ind...
journal_title：Clinical chemistry
pub_type： 杂志文章
doi：
更新日期：1999-02-01 00:00:00
abstract：BACKGROUND:Epidemiologists have observed that blood donation is associated with decreased risk of type 2 diabetes and cardiovascular disease. METHODS:We investigated the relationship between iron stores and insulin sensitivity, after controlling for known confounding factors, and compared insulin sensitivity between b...
journal_title：Clinical chemistry
pub_type： 杂志文章
doi：10.1373/clinchem.2004.046847
更新日期：2005-07-01 00:00:00
abstract：:We describe a group of glycoproteins that are synthesized and released by human breast tumors maintained in organ culture and similar glycoproteins released by a human breast carcinoma cell line (BT-20). The electrophoretic mobility of these glycoproteins on cellulose acetate is consistent with increased glycoprotein-...
journal_title：Clinical chemistry
pub_type： 杂志文章
doi：
更新日期：1977-11-01 00:00:00
abstract：BACKGROUND:Lysosomal storage disorders (LSDs) comprise more than 40 genetic diseases that result in the accumulation of products that would normally be degraded by lysosomal enzymes. A tandem mass spectrometry (MS/MS)-based method is available for newborn screening for 5 LSDs, and many laboratories are initiating pilot...
journal_title：Clinical chemistry
pub_type： 杂志文章
doi：10.1373/clinchem.2008.111864
更新日期：2009-01-01 00:00:00
