Abstract：
BACKGROUND:Nandrolone is one of the most abused anabolic steroids, and its use in doping is increasing, as revealed by numerous positive cases during recent years in various sports. Different authors have reported the possible natural production of nandrolone metabolites in humans, and some of these authors argued that exhaustive exercise could increase nandrolone production in the body or induce dehydration and consequently lead to an increase of nandrolone metabolites in urine. METHODS:Volunteers (n = 22) ingested two 25-mg doses of [(13)C]nandrolone at 24-h intervals and collected urine specimens for 5 days. The labeled nandrolone metabolites 19-norandrosterone and 19-noretiocholanolone were identified and quantified by gas chromatography-mass spectrometry. RESULTS:Interindividual variability was observed in nandrolone excretion patterns and kinetics, as well as for the noretiocholanolone:norandrosterone ratio. The amounts of nandrolone metabolites measured at the excretion peak varied between 1180 and 38 661 microg/L for norandrosterone and 576 and 12 328 microg/L for noretiocholanolone. At the end of the excretion period, the noretiocholanolone:norandrosterone ratio was sometimes >1. The analysis of numerous spot-urine samples allowed the determination of an acceptable correlation between urinary creatinine and specific gravity for placebo- and steroid-treated individuals: y = 0.0052ln(x) + 1.0178 (r(2) = 0.8142) and y = 0.0068ln(x) + 1.0172 (r(2) = 0.7730), respectively. CONCLUSIONS:The excretion kinetics and patterns of labeled nandrolone show interindividual variability. More investigations are currently underway to estimate the influence of exhaustive exercises on excretion of labeled nandrolone metabolites in urine.
journal_name
Clin Chemjournal_title
Clinical chemistryauthors
Baume N,Avois L,Schweizer C,Cardis C,Dvorak J,Cauderay M,Mangin P,Saugy Mdoi
10.1373/clinchem.2003.022848subject
Has Abstractpub_date
2004-02-01 00:00:00pages
355-64issue
2eissn
0009-9147issn
1530-8561pii
clinchem.2003.022848journal_volume
50pub_type
临床试验,杂志文章abstract：:We studied the EMIT (Enzyme Multiplied Immunoassay Technique, Syva) procedures for the assay of phenytoin and phenobarbital in serum, adapting them to the miniature Centrifugal Fast Analyzer. For different concentrations of drug, each rate of reaction decreased continuously with time, tending to converge on a single c...
journal_title：Clinical chemistry
pub_type： 杂志文章
doi：
更新日期：1977-08-01 00:00:00
abstract：:Two-hour postprandial specimens have a -14% proportional bias for lipoprotein(a) [Lp(a)], a -0.035 g/L systematic bias for apolipoprotein (apo) A-I, and a -9% proportional bias for apo B, compared with values in 12-h fasting specimens. Although a physiological hemodilution appears to account for a portion of these bia...
journal_title：Clinical chemistry
pub_type： 杂志文章
doi：
更新日期：1992-03-01 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：:A column-switching HPLC system was utilized for the simultaneous determination of epinephrine, norepinephrine, dopamine, serotonin, and their metabolites metanephrine, normetanephrine, 3, 4-dihydroxyphenylacetic acid, homovanillic acid, and 5-hydroxyindoleacetic acid in human urine. The sample was injected directly on...
journal_title：Clinical chemistry
pub_type： 杂志文章
doi：
更新日期：1999-02-01 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 the measurement of rheumatoid factor in human sera with a rate nephelometer. The National Reference Preparation for Rheumatoid Factors is used to calibrate the assay in International Units. We used Hyland Positive Control, Level I, as a secondary standard. The standard curve is exponential, but is linear w...
journal_title：Clinical chemistry
pub_type： 杂志文章
doi：
更新日期：1979-11-01 00:00:00
abstract：BACKGROUND:Dopa-responsive dystonia (DRD) and tetrahydrobiopterin (BH4) defects are inherited disorders characterized by monoamine neurotransmitter deficiency with decreased activity of one of the BH4-metabolizing enzymes. The aim of the study was to determine the utility of cultured skin fibroblasts for the diagnosis ...
journal_title：Clinical chemistry
pub_type： 杂志文章
doi：
更新日期：2001-03-01 00:00:00
abstract：:A novel flow-through design for a calcium ion-selective liquid membrane and half-cell is proposed. The membrane is based on a neutral carrier for calcium and has the same quantitative chemical composition as that used in most commercial analyzers for ionized calcium (iCa2+). The membrane and half-cell follow the speci...
journal_title：Clinical chemistry
pub_type： 杂志文章
doi：
更新日期：1992-07-01 00:00:00
abstract：BACKGROUND:The lead mobilization test reflects the mobilizable and likely toxicologically active fraction of the lead body burden. We propose a safe and convenient protocol for this test, to assess concomitant copper and zinc excretion and to determine the size of the chelatable lead pool in nonoccupationally exposed a...
journal_title：Clinical chemistry
pub_type： 临床试验,杂志文章
doi：10.1373/clinchem.2005.051128
更新日期：2006-01-01 00:00:00
abstract：:We compared different sample-handling techniques for measurement of Na+ and K+ with ion-selective electrodes (ISE). Imprecision was less for venous blood (with a minimum of heparin) than for plasma, serum, or capillary blood. The results for K+ were higher for serum than for whole blood, and higher for whole blood tha...
journal_title：Clinical chemistry
pub_type： 杂志文章
doi：
更新日期：1984-03-01 00:00:00
abstract：BACKGROUND:The aims of this study were to measure the N-terminal fragment of pro-brain natriuretic peptide (proBNP) in plasma in medical conditions commonly found in primary care and to evaluate the utility of these measurements in identifying impaired cardiac function in elderly patients with symptoms associated with ...
journal_title：Clinical chemistry
pub_type： 杂志文章
doi：10.1373/49.8.1337
更新日期：2003-08-01 00:00:00
abstract：:A highly sensitive two-site sandwich ELISA measuring total proinsulin immunoreactive material in serum or plasma was developed. The assay was based on two monoclonal antibodies, an anti-C-peptide antibody bound to a microtest plate and a biotin-labeled anti-insulin antibody. The detection limit (3 SD above zero value)...
journal_title：Clinical chemistry
pub_type： 杂志文章
doi：
更新日期：1993-10-01 00:00:00
abstract：:Determination of the MB isoenzyme of creatine kinase in patients with acute myocardial infarction may be disturbed by the presence of macro creatine kinase. The relative molecular mass of this form of creatine kinase in human serum is at least threefold that of the ordinary enzyme, and it is more thermostable. Here we...
journal_title：Clinical chemistry
pub_type： 杂志文章
doi：
更新日期：1982-01-01 00:00:00
abstract：BACKGROUND:Tartrate-resistant acid phosphatase (AcP) 5b is a marker of osteoclastic activity and bone resorption. Immunoassays for serum TRAcP may lack sensitivity and specificity because of the presence of non-bone isoform 5a. The purpose of this study was to isolate the serum isoforms, quantify their disease-related ...
journal_title：Clinical chemistry
pub_type： 杂志文章
doi：
更新日期：2001-01-01 00:00:00
abstract：BACKGROUND:Extracellular matrix alterations are important elements in the arterial changes seen in diabetes, being associated with increased vascular stiffness and the development of cardiovascular diseases. However, no biomarkers for diabetes-related arterial changes have been defined. METHODS:Mammary artery specimen...
journal_title：Clinical chemistry
pub_type： 杂志文章
doi：10.1373/clinchem.2011.162966
更新日期：2011-11-01 00:00:00
abstract：BACKGROUND:Mitochondrial diseases are clinically and genetically heterogeneous, with variable penetrance, expressivity, and differing age of onset. Disease-causing point mutations and large deletions in the mitochondrial genome often exist in a heteroplasmic state. Current molecular analyses require multiple different ...
journal_title：Clinical chemistry
pub_type： 杂志文章
doi：10.1373/clinchem.2011.181438
更新日期：2012-09-01 00:00:00
abstract：BACKGROUND:In the workup of patients with suspected hereditary nonpolyposis colorectal cancer (HNPCC), detection of loss of heterozygosity (LOH) could help pinpoint the mismatch-repair (MMR) gene carrying the germline mutation, but analysis of microsatellite markers has proved unreliable for this purpose. We developed ...
journal_title：Clinical chemistry
pub_type： 杂志文章
doi：10.1373/clinchem.2008.108902
更新日期：2008-11-01 00:00:00
abstract：:By using bivariate probability estimation for the diagnosis of acute myocardial infarction (AMI) we show how to overcome the difficulties encountered for patients whose clinical presentation is atypical and those encountered when multiple isoenzyme determinations are treated by univariate methods. We use the values fo...
journal_title：Clinical chemistry
pub_type： 杂志文章
doi：
更新日期：1989-03-01 00:00:00
abstract：:The location of the Reference Value for an analyte within the population distribution affects the magnitude of error due to methodological bias. Using the gaussian distribution, we evaluated the effects of systematic and proportional biases of the method (positive and negative), mean value, and standard deviation on t...
journal_title：Clinical chemistry
pub_type： 杂志文章
doi：
更新日期：1988-11-01 00:00:00
abstract：BACKGROUND:Specific gravity (SG) may perform as well as creatinine (CR) correction for adjusting urinary hormone concentrations, as well as offer some advantages. We compared the two methods and applied them to US and Bangladeshi specimens to evaluate their use in different populations. METHODS:Pearson correlations be...
journal_title：Clinical chemistry
pub_type： 杂志文章
doi：10.1373/clinchem.2004.032292
更新日期：2004-05-01 00:00:00
abstract：:We describe radioimmunoassay for human prostatic acid phosphatase [orthophosphoric-monoester phospho-hydrolase (acid optimum), EC 3.1.3.2] in serum, with use of monospecific antisera raised in rabbits against highly purified acid phosphatase from human prostates. The antiserum did not cross react with partly purified ...
journal_title：Clinical chemistry
pub_type： 杂志文章
doi：
更新日期：1978-11-01 00:00:00
abstract：:Erythrocyte protoporphyrin content is increased in several human and veterinary disorders in which heme synthesis is disrupted. The nature of the defect determines whether zinc protoporphyrin, unchelated (free) protoporphyrin, or both are present in the erythrocytes. Extraction of the protoporphyrin into acetone/water...
journal_title：Clinical chemistry
pub_type： 杂志文章
doi：
更新日期：1981-02-01 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：BACKGROUND:Commercial immunoassays for testosterone (Te) may give inaccurate results for samples from women and children, leading to misdiagnosis and inappropriate treatment. We developed a sensitive and specific tandem mass spectrometric assay for measurement of Te at the concentrations encountered in women and childr...
journal_title：Clinical chemistry
pub_type： 杂志文章
doi：10.1373/clinchem.2005.052167
更新日期：2006-01-01 00:00:00
abstract：:Strand displacement amplification (SDA) is an isothermal, in vitro method of amplifying a DNA sequence for diagnostic purposes. We have combined SDA with fluorescence polarization detection in a closed, homogeneous format. A fluorescently labeled oligodeoxynucleotide detector probe hybridizes to the amplification prod...
journal_title：Clinical chemistry
pub_type： 杂志文章
doi：
更新日期：1996-01-01 00:00:00
abstract：BACKGROUND:Improved methods are required to screen drug candidates for their influences on protein interactions. There is also a compelling need for miniaturization of screening assays, with attendant reductions in reagent consumption and assay costs. METHODS:We used sensitive, miniaturized proximity ligation assays (...
journal_title：Clinical chemistry
pub_type： 杂志文章
doi：10.1373/clinchem.2007.099424
更新日期：2008-07-01 00:00:00
abstract：:Biological variation is inherent in all medical tests and is a major source of error in clinical test interpretation. We use inherent test error due to biological variability as the touchstone by which to validate the clinical acceptability of analytical goals. Analytical goals should consist of sets of complementary ...
journal_title：Clinical chemistry
pub_type： 杂志文章,评审
doi：
更新日期：1993-07-01 00:00:00
abstract：:Three different techniques of lipase (EC 3.1.1.3) determination (titrimetry, nephelometry, and enzyme immunoassay) were used to investigate an interesting effect of ionic strength on enzyme activity. Both activation in the presence of NaCl (140 mmol/L) and strong immunoinhibition were observed for lipase from plasma o...
journal_title：Clinical chemistry
pub_type： 杂志文章
doi：
更新日期：1984-03-01 00:00:00
abstract：:We describe the production and characterization of a high-affinity monoclonal antibody, HB-22, for apolipoprotein (apo) A-I, a major protein of human high-density lipoproteins (HDL). Including Tween 20 in the reaction mixture increased the binding capacity of HB-22 to apo A-I. HB-22 showed monospecific reactivity with...
journal_title：Clinical chemistry
pub_type： 杂志文章
doi：
更新日期：1995-08-01 00:00:00
abstract：:We determined approximately 15,000 laboratory values in 236 individuals between the ages of 60 and 90 y, 22 individuals between 90 and 99 y, and 69 individuals greater than or equal to 100 y, and compared these with values in young adults. We tested 47 different analytes in the 60-90-y group and 93 analytes in the gre...
journal_title：Clinical chemistry
pub_type： 杂志文章
doi：
更新日期：1992-06-01 00:00:00
