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 between serum concentrations and SG, CR, and uncorrected urinary concentrations were compared using paired daily urine and serum specimens from one menstrual cycle from 30 US women. Corrected urinary estrone conjugate and pregnanediol glucuronide concentrations were compared with serum estradiol and progesterone. Urine specimens across one menstrual cycle from 13 Bangladeshi women were used to evaluate the applicability of both methods to a nonindustrialized population. Linear mixed-effects models were used to compare CR and SG values in the Bangladeshi vs US specimens. RESULTS:There was no significant difference between SG-corrected vs serum and CR-corrected vs serum correlations for either assay. Usable CR results were obtained for all US specimens, but 37% of the Bangladeshi specimens were below the CR assay limit of detection. The Bangladeshi sample had significantly lower CR and higher inter- and intrasubject CR variability than the US sample. CONCLUSIONS:SG is a potentially useful alternative to CR correction for normalizing urinary steroid hormone concentrations, particularly in settings where CR values are highly variable or unusually low.
journal_name
Clin Chemjournal_title
Clinical chemistryauthors
Miller RC,Brindle E,Holman DJ,Shofer J,Klein NA,Soules MR,O'Connor KAdoi
10.1373/clinchem.2004.032292subject
Has Abstractpub_date
2004-05-01 00:00:00pages
924-32issue
5eissn
0009-9147issn
1530-8561pii
clinchem.2004.032292journal_volume
50pub_type
杂志文章abstract：BACKGROUND:24,25-Dihydroxyvitamin D [24,25(OH)2D] in serum may be both a nuisance and nutritionally valuable. METHODS:We investigated the impact of 24,25(OH)2D3 on the performance of commercially available immunoassays for serum total 25-hydroxyvitamin D [25(OH)D] using (a) serum from a nationally representative sampl...
journal_title：Clinical chemistry
pub_type： 杂志文章,随机对照试验
doi：10.1373/clinchem.2014.234955
更新日期：2015-04-01 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：: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：BACKGROUND:Measurement of purine and pyrimidine metabolites presents complex problems for separations currently performed by HPLC and thin-layer chromatography in clinical practice. We developed a novel capillary electrophoresis method for this purpose. METHODS:Separations were performed in 60 mmol/L borate-2-amino-2-...
journal_title：Clinical chemistry
pub_type： 杂志文章
doi：
更新日期：1999-12-01 00:00:00
abstract：:We evaluated the analytical performance of new estradiol and progesterone assays performed on the Bayer Immuno 1 system. Within-run and between-day CVs for estradiol at concentrations of 116.8-6645.8 pmol/L were < or = 6.4% and for 5.54-103.95 nmol/L progesterone were < or = 7.7%, thus meeting published analytical goa...
journal_title：Clinical chemistry
pub_type： 杂志文章
doi：
更新日期：1997-09-01 00:00:00
abstract：:We isolated myoglobin from sheep heart by homogenizing cardiac muscle in 70%-saturated ammonium sulfate, followed by chromatography on a column containing carboxymethyl(CM)-Sephadex gel. Two major isoforms of myoglobin, designated Mb 7.9 and Mb 8.1, were separated by chromatofocusing and were distinguished by their di...
journal_title：Clinical chemistry
pub_type： 杂志文章
doi：
更新日期：1989-05-01 00:00:00
abstract：:The clinical value of measuring concentrations of methylmalonic acid in serum (S-MMA) as an aid in the diagnosis of cobalamin deficiency has recently aroused interest. In 58 healthy subjects, ages 40-68 years, we found a 0.95 reference interval of 0.05-0.37 mumol/L (mean 0.21, SD 0.094). In 33 of the subjects, who wer...
journal_title：Clinical chemistry
pub_type： 杂志文章
doi：
更新日期：1990-07-01 00:00:00
abstract：:A recent study has shown that an emission-excitation matrix could be used to provide a unique fingerprint for the selective identification and characterization of certain species of Pseudomonas. This paper describes the results of a systematic study of the variables that contribute to the uniqueness of the fingerprint...
journal_title：Clinical chemistry
pub_type： 历史文章,杂志文章
doi：
更新日期：1980-09-01 00:00:00
abstract：BACKGROUND:With the gradual reopening of economies and resumption of social life, robust surveillance mechanisms should be implemented to control the ongoing COVID-19 pandemic. Unlike RT-qPCR, SARS-CoV-2 whole genome sequencing (cWGS) has the added advantage of identifying cryptic origins of the virus, and the extent o...
journal_title：Clinical chemistry
pub_type： 杂志文章
doi：10.1093/clinchem/hvaa187
更新日期：2020-11-01 00:00:00
abstract：:Patients' sera were analyzed for carbamazepine and ethosuximide by enzyme immunoassay (x) and gas chromatography (y), and the results were compared. The correlation coefficients were: for carbamazepine, x vs. y 0.94 (n = 93); for ethosuximide, x vs. y 0.99 (n = 30). These results suggest that the two methods could be ...
journal_title：Clinical chemistry
pub_type： 杂志文章
doi：
更新日期：1977-09-01 00:00:00
abstract：:We describe a process for preparing a cholesterol-rich lipoprotein extract from bovine serum. The material is used to enhance cholestrol concentration up to 3.5 g/liter in a clear control material from human serum. The optical clarity of the enriched serum is only slightly affected by lyophilization and reconstitution...
journal_title：Clinical chemistry
pub_type： 杂志文章
doi：
更新日期：1976-08-01 00:00:00
abstract：:We describe a procedure for determining amitriptyline and imipramine and their active metabolites nortriptyline and desipramine, respectively, at therapeutic concentrations in human plasma by use of liquid chromatography. The drugs are extracted at pH 10.5 into hexane/isoamyl alcohol, which is evaporated and the resid...
journal_title：Clinical chemistry
pub_type： 杂志文章
doi：
更新日期：1978-01-01 00:00:00
abstract：:A number of immunological techniques--radioimmunoassay, enzyme-linked immunosorbent assay (ELISA), electroimmunoassay, radial immunodiffusion, and a variety of immunoprecipitin assays--have been used to quantify apolipoproteins in plasma. This paper outlines their technical details and discusses their major advantages...
journal_title：Clinical chemistry
pub_type： 杂志文章,评审
doi：
更新日期：1990-04-01 00:00:00
abstract：:The values of apolipoproteins (apo) A-I and B were determined in a population sample of hospital outpatients with a standardized method to verify if the cutpoints calculated in a cross-sectional study in the US are usable with other populations. We also tested the apolipoproteins' ability to discriminate between healt...
journal_title：Clinical chemistry
pub_type： 杂志文章
doi：
更新日期：1998-01-01 00:00:00
abstract：:We measured three renal tubular brush-border enzymes (lactate dehydrogenase, LDH, EC 1.1.1.27; gamma-glutamyltransferase, GGT, EC 2.3.2.2; and alkaline phosphatase, AP, EC 3.1.3.1) in morning urine samples from 48 healthy subjects to check whether different storage times and temperatures could modify enzyme concentrat...
journal_title：Clinical chemistry
pub_type： 杂志文章
doi：
更新日期：1991-08-01 00:00:00
abstract：:We have improved the protocol for RNA quantification by using RNase protection. Instead of precipitation and extraction with phenol and chloroform, we use a faster and more reliable precipitation based on guanidinium thiocyanate (GdSCN). The internal standard is produced by in vitro transcription of a DNA template con...
journal_title：Clinical chemistry
pub_type： 杂志文章
doi：
更新日期：1995-11-01 00:00:00
abstract：BACKGROUND:About 5% of patients with neurofibromatosis type 1 (NF1) bear constitutional microdeletions that encompass NF1 (neurofibromin 1) and neighboring genes. These patients are characterized by the development of a high number of dermal neurofibromas (dNFs), mental retardation, and an increased risk of developing ...
journal_title：Clinical chemistry
pub_type： 杂志文章
doi：10.1373/clinchem.2012.194217
更新日期：2013-06-01 00:00:00
abstract：:Light that penetrates scattering media shows nonlinearities that mask the broad and shallow perturbations made by trace analytes on the background illuminant spectrum. Narrow-band spectroscopic decomposition and deconvolution of such weak bands is a formidable analytical task that pushes the fundamentally linear spect...
journal_title：Clinical chemistry
pub_type： 杂志文章
doi：
更新日期：1994-09-01 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：:We examined the cholesterol/protein ratio and the apoprotein composition of serum lipoproteins in a randomly selected population of maturity-onset diabetics and in a group of nondiabetics of similar age. We found no differences in cholesterol distribution between the groups as a whole, but diabetics with above-normal ...
journal_title：Clinical chemistry
pub_type： 杂志文章
doi：
更新日期：1980-08-01 00:00:00
abstract：:Agarose column chromatography has been used to separate plasma lipoproteins into very-low-density lipoproteins (VLDL), low-density lipoproteins (LDL) and high-density lipoproteins (HDL). Applied to the diagnosis of primary type III hyperlipoproteinemia, the procedure is capable of demonstrating three characteristic an...
journal_title：Clinical chemistry
pub_type： 杂志文章
doi：
更新日期：1975-12-01 00:00:00
abstract：:Measurement of acetaminophen by analysis of the second derivative of its spectrum is specific and sensitive. The method of extraction and the use of just one phosphate buffer as reagent makes this method very convenient. Readings are reliable from 10 to 1500 mg/L. A turnaround time of 20 min makes this method well sui...
journal_title：Clinical chemistry
pub_type： 杂志文章
doi：
更新日期：1988-06-01 00:00:00
abstract：BACKGROUND:Cardiac troponins are specific biochemical markers of myocardial injury used in the diagnosis of acute myocardial disease and cardiac risk stratification. To avoid misclassification of patients, troponin assays must demonstrate precision at the low end of the measuring range. We report our evaluation of the ...
journal_title：Clinical chemistry
pub_type： 杂志文章
doi：10.1373/clinchem.2005.057216
更新日期：2006-02-01 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:The optimal situation in external quality assessment (EQA) is to use commutable materials. No previous study has examined the commutability of a whole-blood material for point-of-care (POC) testing. The aim of this study was to determine the commutability of the Norwegian Quality Improvement of Laboratory Ex...
journal_title：Clinical chemistry
pub_type： 杂志文章
doi：10.1373/clinchem.2018.300202
更新日期：2019-06-01 00:00:00
abstract：BACKGROUND:The B-type natriuretic peptides (BNP and N-terminal pro-BNP) are secreted by the heart and, in the case of BNP, serve to maintain circulatory homeostasis through renal and vascular actions and oppose many effects of the renin-angiotensin system. Recent evidence suggests that in patients with severe heart fai...
journal_title：Clinical chemistry
pub_type： 杂志文章
doi：10.1373/clinchem.2013.210435
更新日期：2014-03-01 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：:We describe a simple, rapid fluorometric assay for separate quantitative analysis of procainamide and N-acetylprocainamide in mixtures. The effective lenear range (fluorescence vs. concentration) in serum is 0.1 to 10.0 mg/liter, regardless of the ratio (by weight) of the two drugs from 1:10 to 10:1. Analytical recove...
journal_title：Clinical chemistry
pub_type： 杂志文章
doi：
更新日期：1975-12-01 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：:A fluorometric assay for free erythrocyte porphyrins (FEP) is described in detail, the direct test being used for the analysis of blood specimens collected with anticoagulants and the spot test for analysis of blood specimens collected on filter paper. A method for determining the amount of blood absorbed by different...
journal_title：Clinical chemistry
pub_type： 杂志文章
doi：
更新日期：1977-02-01 00:00:00
