Abstract：
:Seeking to minimize degradation of NADPH during storage, reagent preparation, and assays, we investigated the effects of pH, temperature, and ionic strength as well as the effects of phosphate and acetate. NADH was also included for comparison. Our results indicate that the rate of degradation of NADPH is proportional most importantly to temperature and concentrations of hydronium ion, but also to concentrations of phosphate and acetate. The degradation rate decreased with increasing ionic strength at neutral pH, but increased slightly at lower pH. NADPH generally is less stable than NADH under the same conditions. The reaction orders with respect to hydronium ion and anions were near 1 for NADH degradation reactions, about 0.5 for NADPH. Rate constants for NADH and NADPH differed more at higher pH and lower phosphate and acetate concentrations.
journal_name
Clin Chemjournal_title
Clinical chemistryauthors
Wu JT,Wu LH,Knight JAsubject
Has Abstractpub_date
1986-02-01 00:00:00pages
314-9issue
2eissn
0009-9147issn
1530-8561journal_volume
32pub_type
杂志文章abstract：:This simple, accurate, and reproducible colorimetric method for determining the activity of angiotensin-I converting enzyme is based upon colorimetry of the quinoneimine dye produced from the substrate p-hydroxyhippuryl-L-histidyl-L-leucine by action of this enzyme through the following series of reactions. The enzyme...
journal_title：Clinical chemistry
pub_type： 杂志文章
doi：
更新日期：1981-11-01 00:00:00
abstract：BACKGROUND:Genomic instability resulting in copy number variation is a hallmark of malignant transformation and may be identified through massive parallel sequencing. Tumor-specific cell free DNA (cfDNA) present in serum and plasma provides a real-time, easily accessible surrogate. METHODS:DNA was extracted from serum...
journal_title：Clinical chemistry
pub_type： 杂志文章
doi：10.1373/clinchem.2014.226571
更新日期：2015-01-01 00:00:00
abstract：:We have compared the operational, medical, and fiscal consequences of performing urgent glucose testing at the bedside vs in the central laboratory. The turnaround time (TAT) with bedside testing was only 1-2 min shorter than that from the central laboratory, to which specimens are sent by pneumatic tube and from whic...
journal_title：Clinical chemistry
pub_type： 杂志文章
doi：
更新日期：1994-08-01 00:00:00
abstract：BACKGROUND:Patients with trophoblastic diseases produce ordinary and irregular forms of human chorionic gonadotropin (hCG; e.g., nicked hCG, hCG missing the beta-subunit C-terminal segment, hyperglycosylated hCG, and free beta subunit) that are recognized to differing extents by automated immunometric hCG (or hCG beta)...
journal_title：Clinical chemistry
pub_type： 杂志文章
doi：
更新日期：2001-02-01 00:00:00
abstract：:Peroxidation of lipids is believed to play a key role in various degenerative diseases. However, few simple tests are able to detect individual susceptibility or resistance to peroxidation. Measurement of the basal concentrations of lipid peroxides in plasma is not satisfactory because they are so low. Therefore, we d...
journal_title：Clinical chemistry
pub_type： 杂志文章
doi：
更新日期：1991-10-01 00:00:00
abstract：:Owing to increased enzymatic hydrolysis of glutamine, additional ammonia is formed in blood and plasma specimens with increased gamma-glutamyltransferase activity (gamma-GT, EC 2.3.2.2.). The close correlation between gamma-GT and glutaminase (EC 3.5.1.2) activities (r = 0.97) in plasma, the inhibition with 6-diazo-5-...
journal_title：Clinical chemistry
pub_type： 杂志文章
doi：
更新日期：1990-08-01 00:00:00
abstract：:We describe a mass-fragmentographic method for determination in urine of the following metabolites of L-3,4-dihydroxyphenylalanine and dopamine: vanillactic acid, 3,4-dihydroxyphenylacetic acid, 3-methoxy-4-hydroxyphenylethanol, and 3,4-dihydroxyphenylethanol. Deuterated analogs were used as internal standards. The me...
journal_title：Clinical chemistry
pub_type： 杂志文章
doi：
更新日期：1978-01-01 00:00:00
abstract：:A 56-year-old Samoan man with a documented history of hypertension, who presented with atrial fibrillation and hypotension, quickly developed renal failure with a serum urea nitrogen of 1.370 g/L and a serum creatinine of 92 mg/L. After hydration of the patient, the creatinine value became normal in two days, the urea...
journal_title：Clinical chemistry
pub_type： 杂志文章
doi：
更新日期：1979-11-01 00:00:00
abstract：:Detection and characterization of small IgM paraproteins by immunoelectrophoresis are often difficult because of (a) slow diffusion of the macromolecular immunoglobulin, and (b) the obscuring of the light chain, especially kappa, by the light chains of background polyclonal immunoglobulin (the "umbrella effect"). Vari...
journal_title：Clinical chemistry
pub_type： 杂志文章
doi：
更新日期：1988-08-01 00:00:00
abstract：BACKGROUND:The analysis of bodily fluids using SELDI-TOF MS has been reported to identify signatures of spectral peaks that can be used to differentiate patients with a specific disease from normal or control patients. This report is the 2nd of 2 companion articles describing a validation study of a SELDI-TOF MS approa...
journal_title：Clinical chemistry
pub_type： 杂志文章,多中心研究
doi：10.1373/clinchem.2007.091496
更新日期：2008-01-01 00:00:00
abstract：:Creatine kinase (CK; EC 2.7.3.2) has been used as an indicator of myocardial cellular damage. In this study we used a Krebs-Henseleit (KH) solution to reperfuse isolated rat hearts after 24 h of cold preservation and collected the KH reperfusate for assay of CK to assess cellular damage. We wanted to determine the sta...
journal_title：Clinical chemistry
pub_type： 杂志文章
doi：
更新日期：1990-05-01 00:00:00
abstract：BACKGROUND:Some of the genetic variants of hemoglobin (Hb) and their chemically modified species are known to affect the measurement of Hb A(1c). The purpose of this study was to characterize Hb species in the blood sample of a 74-year-old German male with an exceptionally low Hb A(1c) value. METHODS:Hemolysates from ...
journal_title：Clinical chemistry
pub_type： 杂志文章
doi：10.1373/49.1.137
更新日期：2003-01-01 00:00:00
abstract：:We review the following labels used as substitutes for radioisotopes in immunoassay systems: bacteriophages, chemiluminescence precursors, fluorochromes, fluorogens, fluorescence quenchers, enzymes, coenzymes, inhibitors, substrates, various particulates, metal atoms, and stable free radicals. New methods for performi...
journal_title：Clinical chemistry
pub_type： 杂志文章,评审
doi：
更新日期：1981-07-01 00:00:00
abstract：BACKGROUND:The analysis of red cell folate (RCF) depends on complete hemolysis of erythrocytes, and it is assumed that complete hemolysis is achieved by 10-fold dilution of whole blood with hypotonic solutions of 10 g/L ascorbic acid/ascorbate. This report challenges this assumption. METHODS:The conventional method of...
journal_title：Clinical chemistry
pub_type： 杂志文章
doi：
更新日期：2000-12-01 00:00:00
abstract：:We describe specific EMIT homogeneous enzyme immunoassays for amitriptyline, nortriptyline, imipramine, and desipramine in patients' serum samples. Before analysis, an easily performed extraction step involving the use of 500 microL of sample and a 1-mL disposable column eliminates cross-reacting polar metabolites. Th...
journal_title：Clinical chemistry
pub_type： 杂志文章
doi：
更新日期：1986-05-01 00:00:00
abstract：BACKGROUND:The determination of cellular beta-galactocerebrosidase activity is an established procedure to diagnose Krabbe disease and monitor the efficacy of gene/stem cell-based therapeutic approaches aimed at restoring defective enzymatic activity in patients or disease models. Current biochemical assays for beta-ga...
journal_title：Clinical chemistry
pub_type： 杂志文章
doi：10.1373/clinchem.2008.115873
更新日期：2009-03-01 00:00:00
abstract：BACKGROUND:HDL is quantitatively the most important lipoprotein in most species and mechanistic evidence points toward a role for HDL in normal immune function. We tested the hypothesis that concentrations of HDL cholesterol are associated with risk of autoimmune disease. METHODS:From 2 studies of the general populati...
journal_title：Clinical chemistry
pub_type： 杂志文章
doi：10.1373/clinchem.2018.299636
更新日期：2019-05-01 00:00:00
abstract：BACKGROUND:Increasing numbers of patients are presenting worldwide to emergency departments with suspected myocardial infarction. The use of point-of-care troponin assays might enable faster decision-making in this high-risk population and reduce the burden on emergency facilities. Here, we evaluate the diagnostic perf...
journal_title：Clinical chemistry
pub_type： 杂志文章
doi：10.1373/clinchem.2019.307405
更新日期：2019-12-01 00:00:00
abstract：:We have studied the influence of triglyceride-rich particles on the analytical bias of apolipoprotein B measurements by various immunoturbidimetric methods. Three commercially available methods grossly overestimate apolipoprotein B in samples with even moderately above-normal triglyceride concentrations. This effect i...
journal_title：Clinical chemistry
pub_type： 杂志文章
doi：
更新日期：1991-05-01 00:00:00
abstract：BACKGROUND:Recent use of Bacillus anthracis spores as a bioweapon has highlighted the need for a continuous monitoring system. Current monitoring systems rely on antibody-derived probes, which are not hardy enough to withstand long-term use under extreme conditions. We describe new, phage-derived probes that can be use...
journal_title：Clinical chemistry
pub_type： 杂志文章
doi：10.1373/clinchem.2004.038018
更新日期：2004-10-01 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：:Four commercial products for urine glucose determination were evaluated and compared with a quantitative hexokinase procedure. We examined precision, sensitivity, and analytical recovery of glucose from glucose-supplemented urine samples and comparison of methods, using patients' samples. Only "Chemstrip uG" (Bio-Dyna...
journal_title：Clinical chemistry
pub_type： 杂志文章
doi：
更新日期：1982-10-01 00:00:00
abstract：BACKGROUND:The European Atherosclerosis Society-European Federation of Clinical Chemistry and Laboratory Medicine Consensus Panel aims to provide recommendations to optimize atherogenic lipoprotein quantification for cardiovascular risk management. CONTENT:We critically examined LDL cholesterol, non-HDL cholesterol, a...
journal_title：Clinical chemistry
pub_type： 杂志文章
doi：10.1373/clinchem.2018.287037
更新日期：2018-07-01 00:00:00
abstract：:The method is based on the selective activating capacity of dithiothreitol on creatine kinase isoenzyme MB, after isoenzyme MM is activated by glutathione. Isolated isoenzymes MM and MB of human and canine origin were assayed individually and in mixtures of known activities. When glutathione was present in the assay m...
journal_title：Clinical chemistry
pub_type： 杂志文章
doi：
更新日期：1975-10-01 00:00:00
abstract：:A modified agarose electrophoretic system for the separation of alkaline phosphatase (ALP, EC 3.1.3.1) isoenzymes is described. Bone, liver, high-molecular-mass, and intestinal ALP are separated with high reproducibility. The sensitivity of the agarose system is superior to cellulose acetate in detecting high-Mr ALP. ...
journal_title：Clinical chemistry
pub_type： 杂志文章
doi：
更新日期：1988-09-01 00:00:00
abstract：BACKGROUND:ADB-PINACA and its 5-fluoropentyl analog 5F-ADB-PINACA are among the most potent synthetic cannabinoids tested to date, with several severe intoxication cases. ADB-PINACA and 5F-ADB-PINACA have a different legal status, depending on the country. Synthetic cannabinoid metabolites predominate in urine, making ...
journal_title：Clinical chemistry
pub_type： 杂志文章
doi：10.1373/clinchem.2016.267575
更新日期：2017-05-01 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：:In this method for serum and urinary urea determination, the same reagent is used without predilution of urine samples. The method is based on the pH increase resulting from the ammonia released by urease hydrolysis of urea. o-Cresolphthalein complexone is used to monitor the pH change colorimetrically. Urea concentra...
journal_title：Clinical chemistry
pub_type： 杂志文章
doi：
更新日期：1992-05-01 00:00:00
abstract：:We devised a method for assaying serum lactate dehydrogenase isoenzyme 1 (LD-1) activity specifically by preincubation with alpha-chymotrypsin and guanidine. Cleavage of phenylalanine bonds in the loop of A and B subunits of LD-3, LD-4, and LD-5 isoenzymes (residues 117-119) by incubation with alpha-chymotrypsin for a...
journal_title：Clinical chemistry
pub_type： 杂志文章
doi：
更新日期：1992-11-01 00:00:00
abstract：:Urinary excretion of orally administered lactulose is used as an index of intestinal permeability. We have developed a simple thin-layer chromatographic technique for measuring lactulose in urine, using silica gel 60 plates and a propanol-borate solvent system. Lactulose concentrations as low as 62.5 mg/L can be detec...
journal_title：Clinical chemistry
pub_type： 杂志文章
doi：
更新日期：1987-07-01 00:00:00
