Abstract:
:A rapid technique (5-10 min) has been developed for fractionating nucleotides from base and nucleoside contaminants in acid extracts of cells, by adsorption to silica gels. Silica gels (1-mL bed volume) were washed with 5 mL of water then with 5 mL of acetonitrile/water (90/10 by vol). After applying 3-mL samples, adjusted to 900 mL/L acetonitrile content, we washed the gel with an additional 10 mL of the acetonitrile/water solvent. More than 95% of the amounts of bases and nucleosides prsent, except for cytidine (92%), did not adsorb to silica under these conditions. Nucleotides were then quantitatively eluted with 9 mL of water. The retention volumes for positive, negative, and neutral nucleic acid components have been determined, to investigate the discriminatory properties of nucleic acid components on silica. Compounds (bases, nucleosides) that are not ionized at pH 7 do not bind to silica. However, negative, positive, and zwitterionic compounds are tightly adsorbed to the silica gels. This procedure has been used to purify nucleotides from several normal and transformed cell lines.
journal_name
Clin Chemjournal_title
Clinical chemistryauthors
Lothrop CD Jr,Uziel Msubject
Has Abstractpub_date
1980-09-01 00:00:00pages
1430-4issue
10eissn
0009-9147issn
1530-8561journal_volume
26pub_type
杂志文章abstract:BACKGROUND:Absolute plasma hepcidin concentrations measured by various procedures differ substantially, complicating interpretation of results and rendering reference intervals method dependent. We investigated the degree of equivalence achievable by harmonization and the identification of a commutable secondary refere...
journal_title:Clinical chemistry
pub_type: 杂志文章
doi:10.1373/clinchem.2016.256768
更新日期:2016-07-01 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::We describe a liquid-chromatographic assay for AZT in human plasma and urine. This assay involves the use of two internal standards, allowing reference of AZT peaks to the appropriate internal standard, the choice depending on the range of concentrations encountered. This method is isocratic, specific, sensitive enoug...
journal_title:Clinical chemistry
pub_type: 杂志文章
doi:
更新日期:1988-08-01 00:00:00
abstract::It has been hypothesized over many years that the autoimmune endocrine diseases are each due to antigen-specific defects in suppressor (regulatory) T lymphocyte function. There is now increasing evidence in studies of autoimmune thyroid disease and insulin-dependent diabetes mellitus that suppressor cells are activate...
journal_title:Clinical chemistry
pub_type: 杂志文章,评审
doi:
更新日期:1994-11-01 00:00:00
abstract::To see if saliva is a valid substitute for plasma in assay of progesterone even when concentrations of hormone and binding proteins are fluctuating, we determined the concentrations of total and free progesterone in plasma and salivary progesterone in specimens from 36 women volunteers during the course of pregnancy a...
journal_title:Clinical chemistry
pub_type: 杂志文章
doi:
更新日期:1989-01-01 00:00:00
abstract::Four double-monoclonal time-resolved immunofluorometric assays (TrIFMAs) have been developed for the specific determination of pregnancy-associated plasma protein A/proeosinophil major basic protein (PAPP-A/ proMBP) complex in first-trimester maternal serum samples. The assays have a functional sensitivity of < 4 mIU/...
journal_title:Clinical chemistry
pub_type: 杂志文章
doi:
更新日期:1997-12-01 00:00:00
abstract::We evaluated superoxide dismutase (EC 1.15.1.1) and glutathione peroxidase (EC 1.11.1.9) activities in the erythrocytes of lead-exposed and nonexposed workers from distinct industries localized in the State of São Paulo, Brazil. Concentrations of either lead or protoporphyrin IX, or both, in blood were used to indicat...
journal_title:Clinical chemistry
pub_type: 杂志文章
doi:
更新日期:1985-10-01 00:00:00
abstract:BACKGROUND:There is extended urinary excretion of Δ(9)-tetrahydrocannabinol (THC), 11-hydroxy-THC (11-OH-THC), and 11-nor-9-carboxy-THC (THCCOOH) in abstinent frequent cannabis smokers. We characterized THC, 11-OH-THC, THCCOOH, cannabidiol, cannabinol, THC-glucuronide, and THCCOOH-glucuronide disposition in urine of fr...
journal_title:Clinical chemistry
pub_type: 临床试验,杂志文章
doi:10.1373/clinchem.2013.214106
更新日期:2014-02-01 00:00:00
abstract::We describe a novel ion-selective electrode (ISE) system that can be used in the Abbott Vision analyzer. A reusable sensor pack and a disposable test pack have been miniaturized to approximately the size and weight of a conventional Vision test pack, thus eliminating the need for a separate ISE module. The sensor pack...
journal_title:Clinical chemistry
pub_type: 杂志文章
doi:
更新日期:1990-12-01 00:00:00
abstract::Cholinesterase activity in human serum was measured calorimetrically and compared to values obtained with the spectrophotometric method of Rappaport et al. [Clin. Chim. Acta 4, 227 (1959)]. The response of the calorimeter upon mixing serum with acetylcholine corresponded to the cholinesterase activity of the serum, th...
journal_title:Clinical chemistry
pub_type: 杂志文章
doi:
更新日期:1977-10-01 00:00:00
abstract::A test kit (Iso-ALP, Boehringer Mannheim) for measuring human bone alkaline phosphatase activity in serum or plasma was evaluated in five laboratories in three countries. The assay is based on the principle described by Rosalki and Foo (Clin Chem 1984;30:1182-6) and uses wheat germ lectin to precipitate bone alkaline ...
journal_title:Clinical chemistry
pub_type: 杂志文章
doi:
更新日期:1993-04-01 00:00:00
abstract::A simple computer-based screening technique has been developed for classifying human expired air components into 16 chemical classes, based on empirical formulas. The sort procedure was developed to simplify the screening of the composition of expired air samples by sorting all components into chemical classes and cla...
journal_title:Clinical chemistry
pub_type: 杂志文章
doi:
更新日期:1988-08-01 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:The sex differential in coronary heart disease (CHD) risk, which is not explained by male/female differences in lipid and lipoprotein concentrations, narrows with age. We examined whether this differential CHD risk might, in part, be attributable to the sizes of lipoprotein particles or concentrations of lip...
journal_title:Clinical chemistry
pub_type: 杂志文章
doi:10.1373/clinchem.2004.032763
更新日期:2004-07-01 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:BACKGROUND:The thiopurine S:-methyltransferase (TPMT) genetic polymorphism has a significant clinical impact on the toxicity of thiopurine drugs, which are used in the treatment of leukemia and as immunosuppressants. To date, 10 mutant alleles are known that are associated with intermediate or low TPMT activity. To fac...
journal_title:Clinical chemistry
pub_type: 杂志文章
doi:
更新日期:2001-03-01 00:00:00
abstract::We describe a ratio gas-chromatographic method for determination of cortisol production rate by measuring the isotope dilution of urinary cortisol metabolites. The method was calibrated by analyzing [3H]tetrahydrocortisol and [3H]tetrahydrocortisone of known specific activities. Results are reasonably well reproducibl...
journal_title:Clinical chemistry
pub_type: 杂志文章
doi:
更新日期:1977-03-01 00:00:00
abstract::Using a solid-phase monoclonal antibody enzyme immuno-assay, we evaluated in a multicenter study (18 laboratories) the utility of evaluating catalytic activity of human placental alkaline phosphatase (hPLAP, EC 3.1.3.1) in serum as a potential tumor marker. We determined hPLAP in serum samples from 130 patients with o...
journal_title:Clinical chemistry
pub_type: 杂志文章
doi:
更新日期:1988-10-01 00:00:00
abstract::We compared relative increases in creatine kinase (EC 2.7.3.2) MB isoenzyme (CK-MB) after reperfusion in myocardial infarction for four popular methods: electrophoresis, immunoinhibition, the "Magic Lite" (Ciba-Corning) system, and the Stratus (Dade). In a method comparison study, we confirmed that all four methods co...
journal_title:Clinical chemistry
pub_type: 杂志文章
doi:
更新日期:1990-08-01 00:00:00
abstract::Consecutive values for serum osmolality measured in a patient exceeded (548 mOsm) the previously reported pathological range and, indeed, exceeded that generally considered compatible with life. The patient was receiving large amounts of intravenous dimethyl sulfoxide as part of an experimental protocol to control int...
journal_title:Clinical chemistry
pub_type: 杂志文章
doi:
更新日期:1980-11-01 00:00:00
abstract:BACKGROUND:Recent publications have explored the possibility of using fingerprints to confirm drug use, but none has yet dealt with environmental contamination from fingertips. Here we explored the possibility of establishing an environmental cutoff for drug testing from a single fingerprint. METHODS:Fingerprint sampl...
journal_title:Clinical chemistry
pub_type: 杂志文章
doi:10.1373/clinchem.2017.281469
更新日期:2018-06-01 00:00:00
abstract::Values of low-density lipoprotein (LDL) cholesterol (C) according to the Friedewald formula (Clin Chem 1972;18:499-502) were compared with those obtained by lipoprotein fractionation in 98 healthy subjects (control group), 135 specimens from patients with peripheral vascular and cerebrovascular disease (atheroscleroti...
journal_title:Clinical chemistry
pub_type: 杂志文章
doi:
更新日期:1991-08-01 00:00:00
abstract::We report here the development of a new method that allows continuous determination of the oxygen dissociation curve for microsamples (600 mul) of whole blood under conditions of pH, pCO2, methemoglobin concentration, and 2,3-diphosphoglycerate content closely approaching those found in the circulatory system. The met...
journal_title:Clinical chemistry
pub_type: 杂志文章
doi:
更新日期:1975-11-01 00:00:00
abstract:BACKGROUND:Laboratory tests can be an important source of blood loss in hospitals, especially for newborns and patients in intensive care. The aim of this study was to quantify blood loss for laboratory diagnostic tests in a large number of patients in a teaching hospital. METHODS:We estimated blood loss by multiplyin...
journal_title:Clinical chemistry
pub_type: 杂志文章
doi:10.1373/49.10.1651
更新日期:2003-10-01 00:00:00
abstract::The carboxyl terminal region of corticotropin (ACTH), (Ala34-Phe-Pro-Glu-Leu-Phe39), a region of the hormone conserved during evolution, served as an antigen for the production of a sequence-specific antiserum. In a radioimmunoassay, peptides that extend toward the amino terminal from Ala34, such as [Tyr,Gly]-ACTH34-3...
journal_title:Clinical chemistry
pub_type: 杂志文章
doi:
更新日期:1981-04-01 00:00:00
abstract::A micro version of a nuclear binding assay to assess the biological activity of receptors for steroid hormones was developed for application to small (needle) biopsies of human tumors for the purpose of predicting responses to steroid therapy. This easier assay requires 10-fold less tissue than the original nuclear bi...
journal_title:Clinical chemistry
pub_type: 杂志文章
doi:
更新日期:1988-02-01 00:00:00
abstract::A region consisting of 19 clinical laboratories harmonized their calibration of seven common enzymes by using fresh patient-pool sera. One of the laboratories was chosen to act as Regional Reference Laboratory (RRL). This laboratory used internationally accepted (mostly IFCC) methods at 37 degrees C, with an intralabo...
journal_title:Clinical chemistry
pub_type: 杂志文章,多中心研究
doi:
更新日期:1998-03-01 00:00:00
abstract::Intra-erythrocytic pH, ATP concentrations, and 2,3-diphosphoglycerate relaxation times were studied in living erythrocytes by "high-resolution" 31P NMR spectroscopy to assess homeostasis within the cells. In uremic patients, intra-erythrocytic pH is significantly decreased before hemodialysis, but is corrected equally...
journal_title:Clinical chemistry
pub_type: 杂志文章
doi:
更新日期:1987-01-01 00:00:00
abstract::We studied the association between gamma-glutamyltransferase (GGT) and apolipoproteins A or B in serum of 42 patients with various hepatobiliary diseases. Binding of the enzyme to apolipoprotein A is not related to a clearly defined disease, but appears to be mainly influenced by the ratio of total cholesterol to GGT ...
journal_title:Clinical chemistry
pub_type: 杂志文章
doi:
更新日期:1984-08-01 00:00:00
abstract:BACKGROUND:The liver is frequently subject to insult because of viral infection, alcohol abuse, or toxic chemical exposure. Extensive research has been conducted to identify blood markers that can better discern liver damage, but little progress has been achieved in clinical practice. Recently, circulating microRNAs (m...
journal_title:Clinical chemistry
pub_type: 杂志文章
doi:10.1373/clinchem.2010.147850
更新日期:2010-12-01 00:00:00