Abstract：
BACKGROUND:Adequate detection of designer steroids in the urine of athletes is still a challenge in doping control analysis and requires knowledge of steroid metabolism. In this study we investigated whether uPA(+/+)-SCID mice carrying functional primary human hepatocytes in their liver would provide a suitable alternative small animal model for the investigation of human steroid metabolism in vivo. METHODS:A quantitative method based on liquid chromatography-tandem mass spectrometry (LC-MS/MS) was developed and validated for the urinary detection of 7 known methandienone metabolites. Application of this method to urine samples from humanized mice after methandienone administration allowed for comparison with data from in vivo human samples and with reported methandienone data from in vitro hepatocyte cultures. RESULTS:The LC-MS/MS method validation in mouse and human urine indicated good linearity, precision, and recovery. Using this method we quantified 6 of 7 known human methandienone metabolites in the urine of chimeric mice, whereas in control nonchimeric mice we detected only 2 metabolites. These results correlated very well with methandienone metabolism in humans. In addition, we detected 4 isomers of methandienone metabolites in both human and chimeric mouse urine. One of these isomers has never been reported before. CONCLUSIONS:The results of this proof-of-concept study indicate that the human liver-uPA(+/+)-SCID mouse appears to be a suitable small animal model for the investigation of human-type metabolism of anabolic steroids and possibly also for other types of drugs and medications.
journal_name
Clin Chemjournal_title
Clinical chemistryauthors
Lootens L,Meuleman P,Pozo OJ,Van Eenoo P,Leroux-Roels G,Delbeke FTdoi
10.1373/clinchem.2008.119396subject
Has Abstractpub_date
2009-10-01 00:00:00pages
1783-93issue
10eissn
0009-9147issn
1530-8561pii
clinchem.2008.119396journal_volume
55pub_type
杂志文章abstract：BACKGROUND:We have developed a silicon-based biosensor that generates a visual signal in response to nucleic acid targets. METHODS:In this system, capture oligonucleotide probes are immobilized on the surface of the biosensor. Interaction of the capture probes with a complementary target and a biotinylated detector ol...
journal_title：Clinical chemistry
pub_type： 杂志文章
doi：
更新日期：1999-09-01 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：:Clinicians confront the classical problem of decision making under uncertainty, but a universal procedure by which they deal with this situation, both in diagnosis and therapy, can be defined. This consists in the choice of a specific course of action from available alternatives so as to reduce uncertainty. Formal ana...
journal_title：Clinical chemistry
pub_type： 杂志文章,评审
doi：
更新日期：1995-08-01 00:00:00
abstract：:We describe a simple and convenient method for processing small amounts of tissue samples for trace-metal measurements by atomic absorption spectrometry, by use of a modified Parr microwave digestion bomb. Digestion proceeds rapidly (less than or equal to 90 s) in a sealed Teflon-lined vessel that eliminates contamina...
journal_title：Clinical chemistry
pub_type： 杂志文章
doi：
更新日期：1989-03-01 00:00:00
abstract：BACKGROUND:The TDx Fetal Lung Maturity II (FLM II) assay uses amniotic fluid to assess lung maturity of the unborn infant. We investigated common preanalytical factors that influence FLM results, including centrifugation, sample storage, and contamination by whole blood. METHODS:We tested 18 specimens after centrifuga...
journal_title：Clinical chemistry
pub_type： 杂志文章
doi：10.1373/49.6.935
更新日期：2003-06-01 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：:We report the first solid-phase radioimmunoassay for triiodothyronine with use of antibody-coated tubes, which is designed specifically for the fully automated radioimmunoassay instrument, Micromedic Systems' "Concept 4 Automatic Radioassay." Antisera to triiodothyropropionic acid/bovine serum albumin were raised in r...
journal_title：Clinical chemistry
pub_type： 杂志文章
doi：
更新日期：1977-05-01 00:00:00
abstract：:We describe the influence of autoantibodies that bind creatine kinase BB (CK-BB) on the methods for MB isoenzyme. If these autoantibodies are present in patients' sera, they cause the formation of macro CK type 1 (immunoglobulin-linked CK-BB). In some of these cases they can bind not only endogenous CK-BB but also CK-...
journal_title：Clinical chemistry
pub_type： 杂志文章
doi：
更新日期：1985-07-01 00:00:00
abstract：:Estrogen receptor (ER) and progestin receptor (PR) concentrations in tumor biopsies are important predictive indicators of a clinical response to endocrine therapy of breast cancer. To assess interference of O.C.T. (optimum cutting temperature) embedding compound in assays of ER and PR by radioligand binding, we deter...
journal_title：Clinical chemistry
pub_type： 杂志文章
doi：
更新日期：1989-12-01 00:00:00
abstract：:A method is described for separating antibody-bound from free fractions in ligand assays by column affinity chromatography, and its application to radioimmunoassay of choriomammotropin. In the method, 70 x 10 mm (i.d.) polypropylene columns containing about 150 mg of immunosorbent (goat anti-rabbit gamma-globulins cov...
journal_title：Clinical chemistry
pub_type： 杂志文章
doi：
更新日期：1981-06-01 00:00:00
abstract：BACKGROUND:Diabetes mellitus has been historically divided into type 1 and type 2 diabetes, with type 1 being an autoimmune disease and type 2 being primarily a metabolic disease. CONTENT:The current diabetes classification scheme needs to be reevaluated because of the accumulating evidence of immune system involvemen...
journal_title：Clinical chemistry
pub_type： 杂志文章,评审
doi：10.1373/clinchem.2010.148270
更新日期：2011-02-01 00:00:00
abstract：:We present evidence for the utility of an improved assay for the activity of lactate dehydrogenase (EC 1.1.1.27) isoenzymes 1 and 2 in serum, involving inhibition of the H-subunit of LD by pyruvate at pH 7.1. Results correlate well with the LD-1/total LD ratio as evaluated by immunological assay and, as an index to in...
journal_title：Clinical chemistry
pub_type： 杂志文章
doi：
更新日期：1986-05-01 00:00:00
abstract：:I present the general pattern relationship between (a) plasma fibrinogen and cholinesterase activity and (b) plasma fibrinogen and hemoglobin, in 250 and 310 hospitalized adults, respectively. Although responses of cholinesterase were often unrelated to fibrinogen, when its activity in plasma was depressed, above-norm...
journal_title：Clinical chemistry
pub_type： 杂志文章
doi：
更新日期：1977-01-01 00:00:00
abstract：:Determination of the concentration of erythrocyte folate by means of competitive protein binding assay critically depends on the extraction procedure applied. Results will be influenced by variable factors such as the in vitro age of the blood samples, the degree of hemolysis, the presence of ascorbic acid, and the pH...
journal_title：Clinical chemistry
pub_type： 杂志文章
doi：
更新日期：1976-07-01 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：:We describe a chromatographic system involving a high-performance chemically-bonded reverse-phase column and fluorescence detection for measurement of indoles in urine. We controlled retention and selectivity by optimizing the methanol content and pH of the mobile phase. Six reference indoles were separated in less th...
journal_title：Clinical chemistry
pub_type： 杂志文章
doi：
更新日期：1976-02-01 00:00:00
abstract：:To assess the distribution of serum concentrations of the atherogenic lipoprotein(a) [Lp(a)] in an obese population and the possible effects of weight reduction, we determined Lp(a) in 52 white, moderately obese subjects (16 men and 36 women). The subjects were participating in a weight-reduction program of diet, exer...
journal_title：Clinical chemistry
pub_type： 临床试验,杂志文章
doi：
更新日期：1991-07-01 00:00:00
abstract：:We evaluated six precipitation methods for high-density lipoprotein cholesterol (HDL-chol) determination: the heparin/Mn2+ precipitation reagent method (Hep), two variants of the phosphotungstic acid/Mg2+ method (Tung-L and Tung-B), the dextran sulfate 50,000/Mg2+ method (Dex), the PEG 6000 method (PEG), and the PEG 6...
journal_title：Clinical chemistry
pub_type： 杂志文章
doi：
更新日期：1997-04-01 00:00:00
abstract：:We compared measurements of apoprotein A-I (apoA-I) in plasma and in heparin-MnCl2 supernates analyzed by radial immunodiffusion. The apoA-I values were similar when the samples were fresh [n = 41, mean (SD), mg/L: plasma, 1393.4(349); heparin-MnCl2 supernates, 1364.9(332), p less than 0.01], but were greater than 8% ...
journal_title：Clinical chemistry
pub_type： 杂志文章
doi：
更新日期：1986-06-01 00:00:00
abstract：:The new oral formulation of cyclosporine (CsA), Neoral (CsA-N), results in increased area under the curve (AUC) and decreased intra- and interindividual variation in blood concentrations and other pharmacokinetic (PK) parameters when compared with the current Sand-immune (CsA-S) formulation. The present study examines...
journal_title：Clinical chemistry
pub_type： 杂志文章
doi：
更新日期：1997-01-01 00:00:00
abstract：:Serum free thyroxin (FT4) was determined in 40 patients with various nonthyroidal illnesses. We studied seven methods: (1) a free thyroxin index calculated from total T4 and triiodothyronine resin uptake; (2) a free T4 index determined by enzyme inhibitor assays (Abbott's "Tetrazyme" and "Thyrozyme"); (3) a free T4 in...
journal_title：Clinical chemistry
pub_type： 杂志文章
doi：
更新日期：1983-12-01 00:00:00
abstract：:We describe a mechanized method for centrifugal analyzer determination of sorbitol dehydrogenase in serum, based on conversion of D-fructose to sorbitol with simultaneous oxidation of NADH, in triethanolamine buffer at pH 7.4 and 30 degrees C. The standard curve for this assay is linear to 200 U of activity per liter ...
journal_title：Clinical chemistry
pub_type： 杂志文章
doi：
更新日期：1979-12-01 00:00:00
abstract：BACKGROUND:Little research has been done to examine whether gamma-glutamyltransferase (GGT) is prospectively associated with the development of chronic kidney disease (CKD). We performed a prospective study to examine the association between GGT and the risk for the development of CKD. METHODS:The study cohort include...
journal_title：Clinical chemistry
pub_type： 杂志文章
doi：10.1373/clinchem.2006.078980
更新日期：2007-01-01 00:00:00
abstract：BACKGROUND:Coffee consumption has been associated with several risk factors for coronary heart disease, including increased cholesterol, increased blood pressure, and increased plasma total homocysteine (tHcy). tHcy is determined by several B-vitamins. However, reports about the association between coffee intake and B-...
journal_title：Clinical chemistry
pub_type： 杂志文章
doi：10.1373/clinchem.2008.103465
更新日期：2008-09-01 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：BACKGROUND:Although cardiac troponin (cTn) is a cornerstone marker in the assessment and management of patients with acute coronary syndrome (ACS) and heart failure (HF), cTn is not diagnostically specific for any single myocardial disease process. This narrative review discusses increases in cTn that result from acute...
journal_title：Clinical chemistry
pub_type： 杂志文章,评审
doi：10.1373/clinchem.2009.130799
更新日期：2009-12-01 00:00:00
abstract：:Circulating prostate cells can be detected in cancer patients by using reverse transcriptase-PCR (RT-PCR) assay for prostate-specific antigen (PSA) and prostate-specific membrane antigen (PSM) mRNA. A quality-control study involving a conventional RT-PCR assay was performed and, surprisingly, detected both transcripts...
journal_title：Clinical chemistry
pub_type： 杂志文章
doi：
更新日期：1998-03-01 00:00:00
abstract：:Numerous papers have been written to show which combinations of Shewhart-type quality-control charts are optimal for detecting systematic shifts in the mean response of a process, increases in the random error of a process, and linear drift effects in the mean response across the assay batch. One paper by Westgard et ...
journal_title：Clinical chemistry
pub_type： 杂志文章
doi：
更新日期：1993-08-01 00:00:00
abstract：:We evaluated the EMIT (enzyme-multiplied immuno technique) and FPIA (fluorescence polarization immunoassay) urine screening systems for detection of benzodiazepine intake. Healthy male volunteers were given single oral therapeutic doses of alprazolam (2 mg), chlordiazepoxide (25 mg), flunitrazepam (1 mg), lorazepam (3...
journal_title：Clinical chemistry
pub_type： 杂志文章
doi：
更新日期：1992-02-01 00:00:00
abstract：:Imferon (Merrell-National), an iron-dextran complex, is widely used in patients with iron deficiency. It is present in the circulation in appreciable amounts for two to three weeks after administration and interferes with all tested colorimetric iron assays, both with and without deproteinization. The amount of the pl...
journal_title：Clinical chemistry
pub_type： 杂志文章
doi：
更新日期：1980-04-01 00:00:00
