Abstract:
:We review recently developed reference methods based on mass fragmentography (specific ion monitoring) with use of isotope-labeled internal standard, for determination of cholesterol, triglycerides, urea, glucose, cortisol, progesterone, and testosterone. With an optimal ratio between standard and material to be determined, the relative standard deviation of these methods, based on duplicate determinations, is between 1.3 and 2.7%. The very high specificity of the methods, in combination with the fact that the ratio between labeled and unlabeled molecules is determined with a high degree of accuracy, makes it likely that the most significant errors in the methods are related to errors in pipetting. The possibility is discussed that these methods might be developed into "absolute" or "definitive" methods by subjecting each individual step in the determination to a detailed analysis with respect to possible error. We also discuss some of the consequences of the different reference methods on the choice of routine methods.
journal_name
Clin Chemjournal_title
Clinical chemistryauthors
Björkhem I,Blomstrand R,Lantto O,Svensson L,Ohman Gsubject
Has Abstractpub_date
1976-11-01 00:00:00pages
1789-801issue
11eissn
0009-9147issn
1530-8561journal_volume
22pub_type
杂志文章abstract:BACKGROUND:Kallikrein-related peptidase 6 (KLK6), a member of the serine protease family of kallikrein (KLK) genes, is dysregulated in ovarian carcinomas (OCa) and its overexpression is associated with poor prognosis. Regulation of its expression is poorly understood and is likely to be influenced by multiple mechanism...
journal_title:Clinical chemistry
pub_type: 杂志文章
doi:10.1373/clinchem.2012.193060
更新日期:2013-01-01 00:00:00
abstract::We describe a rapid and simple insulin RIA in which proinsulin and conversion intermediates do not interfere. Three monoclonal antibodies (S1, S2, and S53) were selected for their specificity (directed, respectively, against the B10 region, the junction between A chain and C-peptide, and the junction between B chain a...
journal_title:Clinical chemistry
pub_type: 杂志文章
doi:
更新日期:1998-07-01 00:00:00
abstract:BACKGROUND:Dried blood spots (DBS) are a convenient and inexpensive method for biobanking. Although many countries have established population-based DBS biobanks from neonatal screening programs, the quality and usefulness of DNA from DBS have not been extensively assessed. METHODS:We compared 4 common DNA extraction ...
journal_title:Clinical chemistry
pub_type: 杂志文章
doi:10.1373/clinchem.2007.087510
更新日期:2007-08-01 00:00:00
abstract::We present an improved Na+-selective liquid membrane electrode for measurement of Na+ concentrations in both undiluted serum and urine. The values for urinary Na+ obtained with the ion-selective electrode agree well with those obtained with the flame photometer. The correlation gives a standard residual deviation of +...
journal_title:Clinical chemistry
pub_type: 杂志文章
doi:
更新日期:1983-08-01 00:00:00
abstract::We have separated serum proteins in only 15 min by high-performance liquid chromatography. The identification of several peaks in the chromatographic profile was greatly aided by the use of multiple-wavelength detection. We have found a good correlation between retention times and electrophoretic mobilities. Serum sam...
journal_title:Clinical chemistry
pub_type: 杂志文章
doi:
更新日期:1980-09-01 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::We describe specifications for high-purity 4-nitrophenol, which is suitable for spectrophotometric standardization. Such a reference material is needed in clinical enzymology to establish the proper molar absorptivity of 4-nitrophenol under final reaction conditions, particularly for measuring alkaline phosphatase act...
journal_title:Clinical chemistry
pub_type: 杂志文章
doi:
更新日期:1980-05-01 00:00:00
abstract::We developed a highly sensitive, convenient assay for measuring blocking-type anti-acetylcholine receptor antibodies, which inhibit the binding of 125I-labeled alpha-bungarotoxin (alpha-BuTx) to the acetylcholine receptor (AChR). This procedure detected inhibitory activities in sera from 76% of patients with myastheni...
journal_title:Clinical chemistry
pub_type: 杂志文章
doi:
更新日期:1993-10-01 00:00:00
abstract::Intravascular monitoring of arterial blood gases provides the means to detect precipitous change in cardiopulmonary function almost instantaneously, promising major improvement in the ability to manage critically ill patients. Attempts to miniaturize and repackage conventional electrodes for continuous intravascular u...
journal_title:Clinical chemistry
pub_type: 杂志文章
doi:
更新日期:1990-08-01 00:00:00
abstract::As the clinical utility of glycated hemoglobin (gHb) measurement increases, so does the need for standardization of values between different methods and different laboratories. Using three different methods, we examined the feasibility of interlaboratory standardization of gHb measurement. A liquid-chromatographic (HP...
journal_title:Clinical chemistry
pub_type: 杂志文章
doi:
更新日期:1986-02-01 00:00:00
abstract::We describe an automated determination of serum hexosamine by the Elson-Morgan reaction, together with reagent modifications that minimiz interference from amino acids and sugars present in acid hydrolysates of sera. We used a novel 15-min autoclave procedure for the acid hydrolysis of sera before analysis to facilita...
journal_title:Clinical chemistry
pub_type: 杂志文章
doi:
更新日期:1976-08-01 00:00:00
abstract::Adrenocortical causes of hypertension are established by examining the mineralocorticoid hormones produced in the zona glomerulosa and zona fasciculata. In the zona glomerulosa, aldosterone excess leads to hypertension, hypokalemia, and suppressed plasma renin activity, with increased concentrations of urinary aldoste...
journal_title:Clinical chemistry
pub_type: 杂志文章,评审
doi:
更新日期:1991-10-01 00:00:00
abstract:BACKGROUND:Growth differentiation factor 15 (GDF15), a stress-responsive cytokine produced in cardiovascular cells under conditions of inflammation and oxidative stress, is emerging as an important prognostic marker in individuals with and without existing cardiovascular disease (CVD). We therefore examined the clinica...
journal_title:Clinical chemistry
pub_type: 杂志文章,meta分析
doi:10.1373/clinchem.2012.190322
更新日期:2012-11-01 00:00:00
abstract:BACKGROUND:High-resolution DNA melting analysis of small amplicons is a simple and inexpensive technique for genotyping. Microfluidics allows precise and rapid control of temperature during melting. METHODS:Using a microfluidic platform for serial PCR and melting analysis, 4 targets containing single nucleotide varian...
journal_title:Clinical chemistry
pub_type: 杂志文章
doi:10.1373/clinchem.2017.276147
更新日期:2017-10-01 00:00:00
abstract::The contribution of the exocrine pancreas to hyperamylasemia in diabetic ketoacidosis was investigated by measuring total amylase, salivary and pancreatic isoamylases, cathodic trypsin-like immunoreactivity, and pancreatic lipase in 12 consecutive patients recovering from diabetic ketoacidosis. Hyperamylasemia was pre...
journal_title:Clinical chemistry
pub_type: 杂志文章
doi:
更新日期:1985-12-01 00:00:00
abstract::We compare measurement of total fast hemoglobin (HbA1) by "high-performance" liquid chromatography and by electrophoresis on agar gel. Blood samples were obtained from a diverse population (n = 222): offspring of two diabetic parents, diabetic patients with and without retinopathy, diabetic and non-diabetic pregnant w...
journal_title:Clinical chemistry
pub_type: 杂志文章
doi:
更新日期:1981-03-01 00:00:00
abstract:BACKGROUND:We describe a simple tetra-primer amplification refractory mutation system PCR (T-ARMS-PCR) for detecting MUTYH mutations, which are associated with colorectal adenomas and colorectal cancer. METHODS:We designed specific T-ARMS-PCR assays for 6 mutations (Y165C, G382D, 1395_7delGGA, Y90X, 1103delC, and R231...
journal_title:Clinical chemistry
pub_type: 杂志文章
doi:10.1373/clinchem.2005.060137
更新日期:2006-04-01 00:00:00
abstract::This new one-step chemiluminescent immunoassay of free thyroxin (FT4) involving a thyroxin-immunoglobulin conjugate labeled with acridinium ester (Magic Lite System; Ciba Corning Diagnostics Corp., Medfield, MA) is rapid (one 1-h incubation), requires two calibrators per run, and takes 10 s per sample for the quantifi...
journal_title:Clinical chemistry
pub_type: 杂志文章
doi:
更新日期:1988-12-01 00:00:00
abstract:BACKGROUND:Buprenorphine is under investigation as a pharmacotherapeutic agent for treating opioid dependence in pregnant women. We hypothesized that there would be a relationship between the cumulative maternal dose of buprenorphine during pregnancy and the concentration of buprenorphine and norbuprenorphine in matern...
journal_title:Clinical chemistry
pub_type: 临床试验,杂志文章
doi:10.1373/clinchem.2007.091413
更新日期:2007-12-01 00:00:00
abstract::We describe a gas--liquid-chromatographic method for determining the concentration of amantadine hydrochloride in urine with beta-phenylethylamine as internal standard. The urine sample is made alkaline and extracted with 0.5 mL of chloroform. After centrifugation the aqueous layer is aspirated, and an aliquot of the ...
journal_title:Clinical chemistry
pub_type: 杂志文章
doi:
更新日期:1980-02-01 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::Mycophenolate mofetil, the prodrug form of the immunosuppressive agent mycophenolic acid (MPA), is currently in clinical trials evaluating its effectiveness in transplant recipients. In this study, we validated an ultrafiltration system for the reliable measurement of free MPA. Using this technique, we evaluated facto...
journal_title:Clinical chemistry
pub_type: 杂志文章
doi:
更新日期:1995-07-01 00:00:00
abstract::Six different procedures for radioiodination of mouse epidermal growth factor (EGF) all resulted in a heterogeneous 125I-labeled EGF preparation, as analyzed by reversed-phase HPLC. EGF preparations that had been iodinated with Chloramine T, lodogen, or lodo-beads were found mainly to consist of oxidized 125I-labeled ...
journal_title:Clinical chemistry
pub_type: 杂志文章
doi:
更新日期:1992-05-01 00:00:00
abstract:BACKGROUND:Uremic syndrome is the consequence of the retention of solutes usually cleared by the healthy kidneys. p-Cresol can be considered a prototypic protein-bound uremic toxin. It is conceivable, analogous with drugs, that the non-protein-bound fraction of p-cresol exerts toxicity. This aspect had never been evalu...
journal_title:Clinical chemistry
pub_type: 杂志文章
doi:10.1373/49.3.470
更新日期:2003-03-01 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::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::We modified the liquid-chromatographic assay of Schleicher and Wieland (J Clin Chem Clin Biochem 1981; 19:81-7) for measuring lysine-bound glucose in serum proteins, increasing its performance and practicality. After precipitating serum proteins from 10- to 50-microL samples with ethanol (700 mL/L) and hydrolyzing the...
journal_title:Clinical chemistry
pub_type: 杂志文章
doi:
更新日期:1987-09-01 00:00:00
abstract::We describe a novel radioimmunoassay procedure for the direct estimation of aldosterone in unextracted plasma and serum samples, in which interfering binding proteins are digested by Proteinase K (Tritirachium alkaline proteinase, EC 3.4.21.14), a powerful proteolytic enzyme. Heating at 75 degrees C for 15 min inactiv...
journal_title:Clinical chemistry
pub_type: 杂志文章
doi:
更新日期:1981-12-01 00:00:00
abstract::In this liquid-chromatographic method for the determination of bromide in human serum, an important and unique feature is pre-analysis ultrafiltration of the sample, which effectively removes proteins. The chromatographic system consists of an anion-exchange column (Whatman Partisil SAX 10-micron particles), an isocra...
journal_title:Clinical chemistry
pub_type: 杂志文章
doi:
更新日期:1984-05-01 00:00:00
abstract::We compared the analytical performance of the Kodak Ektachem XR700 assays of iron (Fe) and total iron-binding capacity (TIBC) with that of a conventional ferrozine assay (performed with a Cobas-Bio) and occasionally with that of atomic-absorption spectrometry (AAS). The correlation was modest between Kodak and Cobas-B...
journal_title:Clinical chemistry
pub_type: 杂志文章
doi:
更新日期:1990-10-01 00:00:00