Abstract：
:Development of a new, sensitive immunoassay for measuring transforming growth factor beta 1 (TGF-beta1) is described and compared with four commercially available TGF-beta1 immunoassays. Preanalytical conditions were evaluated. The nonlinearity found in serum or plasma is due to masking of TGF-beta1 by binding proteins in blood. Mixing TGF-beta1 with latency-associated peptide or alpha2-macroglobulin at physiological concentrations suppressed most of the TGF-beta1 signal. Plasma fibronectin showed no effect, even at concentrations exceeding its physiological range. Equilibrium concentrations computed from a model system confirmed the experimental results. Dilutional nonlinearity could be markedly reduced by an appropriately designed activation procedure that minimized the effects of reassociation between TGF-beta1 and its binding partners during restoration of a neutral pH. Plasma should be used for measuring TGF-beta1 in blood. Because serum TGF-beta1 is highly significantly correlated with the platelet count, probably most of the TGF-beta1 is released by platelet degranulation.
journal_name
Clin Chemjournal_title
Clinical chemistryauthors
Kropf J,Schurek JO,Wollner A,Gressner AMsubject
Has Abstractpub_date
1997-10-01 00:00:00pages
1965-74issue
10eissn
0009-9147issn
1530-8561journal_volume
43pub_type
杂志文章abstract：:We have developed a sensitive procedure for determination of serum copper by use of the color reagent 4-(3,5-dibromo-2-pyridylazo)-N-ethyl-N-sulfopropylaniline. After mixing serum sample and reagent, and incubating at 37 degrees C for 5 min, we measure the absorbance of the resulting chelate complex at 580 nm (molar a...
journal_title：Clinical chemistry
pub_type： 杂志文章
doi：
更新日期：1989-04-01 00:00:00
abstract：:Urinary acidic and alcoholic catecholamine metabolites were isolated separately from 24-h urines by simple extraction procedures. After derivatization, extracts were analyzed by means of simultaneous gas chromatography on two different stationary phases. The quality of the assay was checked by running "normal" and enr...
journal_title：Clinical chemistry
pub_type： 杂志文章
doi：
更新日期：1977-05-01 00:00:00
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：:We report a procedure for determining fecal long-chain fatty acids (LCFA), triglycerides, and cholesterol after detergent extraction with 10 mL/L Triton X-100, 6 mL/L Brij 30, and 0.1 mol/L HCl in isotonic saline by enzymatic analysis of the extraction supernates. Mean recoveries of calibrators ranged from 105% to 117...
journal_title：Clinical chemistry
pub_type： 杂志文章
doi：
更新日期：1994-12-01 00:00:00
abstract：:The poly-T tract in intron 8 of the cystic fibrosis conductance transmembrane regulator (CFTR) gene exists in three variants, 5T, 7T, and 9T. The 7T and 9T variants generate a predominantly normal transcript, whereas the 5T variant engenders an anomalous product. The analysis of the poly-T tract is assuming increasing...
journal_title：Clinical chemistry
pub_type： 杂志文章
doi：
更新日期：1998-05-01 00:00:00
abstract：:We describe a highly accurate and precise method for determination of total cholesterol in serum by isotope dilution/mass spectrometry. The method was developed for a Study Group of the Committee on Standards of the American Association for Clinical Chemistry, for use in establishing the accuracy of a candidate refere...
journal_title：Clinical chemistry
pub_type： 杂志文章
doi：
更新日期：1980-06-01 00:00:00
abstract：BACKGROUND:Different technologies, such as quantitative real-time PCR or microarrays, have been developed to measure microRNA (miRNA) expression levels. Quantification of miRNA transcripts implicates data normalization using endogenous and exogenous reference genes for data correction. However, there is no consensus ab...
journal_title：Clinical chemistry
pub_type： 杂志文章,评审
doi：10.1373/clinchem.2015.239459
更新日期：2015-11-01 00:00:00
abstract：:Six alpha-amylase (EC 3.2.1.1) isoenzymes have been resolved electrophoretically on cellulose acetate membranes in a discontinuous buffer system. The fastest migrating isoenzymes are of salivary origin (S1, S2, S3), the slower ones of pancreatic origin (P1, P2, P3). We determined the amylase isoenzyme distribution in ...
journal_title：Clinical chemistry
pub_type： 杂志文章
doi：
更新日期：1976-01-01 00:00:00
abstract：:The biological variability of total cholesterol (TC), triglycerides (TG), high-density lipoprotein cholesterol (HDL-C), and calculated low-density lipoprotein cholesterol (LDL-C) was determined in three serial (monthly) capillary and venous specimens from 83 subjects. The analytes were quantified with a desktop analyz...
journal_title：Clinical chemistry
pub_type： 杂志文章
doi：
更新日期：1996-12-01 00:00:00
abstract：BACKGROUND:Patients differ in responses to warfarin, which is commonly prescribed to treat thromboembolic events. Genetic variations in the cytochrome P450, family 2, subfamily C, polypeptide 9 (CYP2C9), vitamin K epoxide reductase complex, subunit 1 (VKORC1), and gamma-glutamyl carboxylase (GGCX) genes have been shown...
journal_title：Clinical chemistry
pub_type： 杂志文章
doi：10.1373/clinchem.2008.118497
更新日期：2009-04-01 00:00:00
abstract：:Two hundred patients with liver disease were re-studied after six to eight years. The initial routine diagnosis (mainly based on morphological criteria) was confirmed in almost 80% of cases of chronic liver disease. In chronic active hepatitis, agreement was found in 86%. An alternative classification based on cluster...
journal_title：Clinical chemistry
pub_type： 杂志文章
doi：
更新日期：1982-05-01 00:00:00
abstract：:We developed a simple method for the analysis of bismuth (Bi) in biological tissue, using wet digestion for sample pretreatment. Bi was determined by electrothermal atomic absorption spectrometry with platinum as a matrix modifier to decrease the volatility of Bi. The furnace program included a gas stop for sensitivit...
journal_title：Clinical chemistry
pub_type： 杂志文章
doi：
更新日期：1993-05-01 00:00:00
abstract：:Cerebrospinal fluid (CSF) from uninfected patients and from patients with bacterial and viral meningitis was analyzed by gas-liquid chromatography, with use of a flame ionization detector, and by gas chromatography-mass spectrometry. The resulting profiles were consistent and reproducible. Hydroxy acids were the compo...
journal_title：Clinical chemistry
pub_type： 杂志文章
doi：
更新日期：1984-07-01 00:00:00
abstract：:Numerous xenobiotics regulate cellular functions by altering transcription of target genes. Use of sensitive and specific biomarkers based on gene transcript levels may help clarify the shape of the dose-response curve in the low-dose region associated with human exposures to environmental concentrations of chemicals....
journal_title：Clinical chemistry
pub_type： 杂志文章,评审
doi：
更新日期：1995-12-01 00:00:00
abstract：:Gel filtration of serum by use of dextran bisacrylamide beads ("Sephacryl S-200," fractionation range: 5000-250 000 daltons), separates the serum proteins into three distinct peaks. We used an eluent containing (per liter) 140 mmol of sodium, 1.10 mmol of calcium, 0.50 mmol of magnesium, and 10 mmol of 2-([2-hydroxy-1...
journal_title：Clinical chemistry
pub_type： 杂志文章
doi：
更新日期：1977-12-01 00:00:00
abstract：:We evaluated a new kinetic assay for alpha-amylase (Phadebas IsoAmylase Test), using modified starch as the substrate and a CentrifiChem 400 centrifugal analyzer system. We determined isoamylase activities by using a selective inhibitor. Results were compared with those obtained with the chromogenic Phadebas dyed-star...
journal_title：Clinical chemistry
pub_type： 杂志文章
doi：
更新日期：1983-06-01 00:00:00
abstract：:We evaluated the enzymic mechanism by which 3-keto butylidene-beta-2-chloro-4-nitrophenyl maltopentaoside (3KB-G5-CNP) serves as a substrate for serum pancreatic (p-) and salivary (s-) amylases. In aliquots of the reaction mixture, three kinds of beta-2-chloro-4-nitrophenyl oligosaccharides (glucose, maltoside, and ma...
journal_title：Clinical chemistry
pub_type： 杂志文章
doi：
更新日期：1991-08-01 00:00:00
abstract：:We describe the measurement of human immunoglobulins IgG, IgA, and IgM in diluted sera, with diluted commercial monospecific antisera, with use of a 36-place centrifugal analyzer (RotoChem IIa; American Instrument Co., Silver Spring, MD 20920). The assay involves a two-point kinetic turbidimetric technique. The change...
journal_title：Clinical chemistry
pub_type： 杂志文章
doi：
更新日期：1979-04-01 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：: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：:We developed a radioimmunoassay with a gamma-emitting radioligand to measure androstenedione in human serum and in dried blood-spot samples from newborns. Antisera were raised in rabbits against androstenedione linked to bovine serum albumin at positions 3, 6, or 11 on the steroid nucleus. Radioligands were prepared b...
journal_title：Clinical chemistry
pub_type： 杂志文章
doi：
更新日期：1989-08-01 00:00:00
abstract：:I describe a micro-scale method for determining lead in whole blood by utilizing a graphite furnace. Sample pretreatment consists of fivefold dilution with a dilute surfactant. The method is directly calibrated with lead standards prepared in dilute HNO3. To eliminate a small, nonspecific absorption signal from the...
journal_title：Clinical chemistry
pub_type： 杂志文章
doi：
更新日期：1975-04-01 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：:We have reported (Clin Chem 29: 42-44, 1983) that prestaining with Remazol Brilliant Blue permits direct visualization of serum components on disc electrophoresis, and apparently purifies the proteins well. Here we have cut out the bands corresponding to the prestained albumin and transferrin after disc electrophoresi...
journal_title：Clinical chemistry
pub_type： 杂志文章
doi：
更新日期：1984-07-01 00:00:00
abstract：:In photometry, where both the product formed and one or several reactants absorb light at the same wavelength, the absorbance of the "blank" of the sample at the end of the reaction may be less than that measured at the beginning of the reaction, because of consumption of reactant(s). The blank correction factor for t...
journal_title：Clinical chemistry
pub_type： 杂志文章
doi：
更新日期：1985-03-01 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：:Even though significant progress has been made in the development of electrodes for the in vivo detection of catecholamines, oxygen, and various cations, there has been little research on the feasibility of continuously monitoring drugs in whole blood by electrochemical sensing devices. Electroanalytical problems asso...
journal_title：Clinical chemistry
pub_type： 杂志文章
doi：
更新日期：1982-09-01 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:Test repetition could be a readily modifiable component of laboratory utilization. Laboratory test repetition has not been rigorously studied at a population-based level. Our objective was to determine the prevalence of, and charges associated with, repetition of eight common laboratory tests. METHODS:We pe...
journal_title：Clinical chemistry
pub_type： 杂志文章
doi：10.1373/clinchem.2003.021220
更新日期：2003-12-01 00:00:00
abstract：:To understand the regulation of immunity one must understand the processes and the consequences of the activation of the lymphoid cell, its clonal proliferation, and the ultimate differentiation of the progeny into the effector elements that constitute the immune system. By use of polyclonal mitogens, individual T-cel...
journal_title：Clinical chemistry
pub_type： 杂志文章
doi：
更新日期：1984-12-01 00:00:00
