Abstract:
:We describe a fixed-time, enzymatic, reaction-rate procedure for determining plasma ammonia with a centrifugal analyzer (Rotochem IIA/36; American Instrument Co., silver Spring, MD 20910), with NADPH as cofactor. The reaction is based on that of da Fonseca-Wollheim's modification [J. Clin. Chem. Clin. Biochem. 11, 421 (1973)] of the Kirstein reaction, which depends on the catalytic amination of alpha-ketoglutarate by the action of glutamate dehydrogenase with NADPH as the cofactor instead of NADH. Use of NADPH minimizes interference from endogenous reactions such as that between lactate dehydrogenase and pyruvate. This method permits shortened preincubation time and thus improves both specificity and precision. This assay requires 100 microliter of freshly collected heparinized plasma, gives quantitative analytical recovery, and the standard curve is linear to 430 mumol/L. Data are presented comparing results with those by two other enzymatic ammonia procedures.
journal_name
Clin Chemjournal_title
Clinical chemistryauthors
Li PK,Shull BCsubject
Has Abstractpub_date
1979-04-01 00:00:00pages
611-3issue
4eissn
0009-9147issn
1530-8561journal_volume
25pub_type
杂志文章abstract:BACKGROUND:Institutions face increasing charges related to molecular genetic testing for neurological diseases. The literature contains little information on the utilization and performance of these tests. METHODS:A retrospective utilization review was performed to determine the diagnostic yield of neurogenetic tests ...
journal_title:Clinical chemistry
pub_type: 杂志文章
doi:10.1373/clinchem.2006.083360
更新日期:2007-06-01 00:00:00
abstract::We describe a high-performance liquid chromatographic method for the quantitative determination of gentamicin in serum. The antibiotic was separated from serum by passage through a silicic acid column, derivatized with o-phthalaldehyde, and eluted with ethanol. The derivatized gentamicin was then separated into all th...
journal_title:Clinical chemistry
pub_type: 杂志文章
doi:
更新日期:1977-12-01 00:00:00
abstract:BACKGROUND:Human herpesvirus 6 (HHV-6) latently infects a majority of adults. In about 1% of the population HHV-6 exists in a chromosomally integrated form (ciHHV-6) that resides in every somatic and germ cell and can be transmitted through the germ line. Patients with ciHHV-6 have been misdiagnosed and unnecessarily t...
journal_title:Clinical chemistry
pub_type: 杂志文章
doi:10.1373/clinchem.2013.217240
更新日期:2014-05-01 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 describe a time-resolved immunofluorometric assay (IFMA) for corticotropin in unextracted human plasma, based on the use of two monoclonal antibodies: europium-labeled antibody 1A12 and antibody 2A3 coated onto microtiter wells. We compared the results of this assay with those of an immunoradiometric assay (IRMA) p...
journal_title:Clinical chemistry
pub_type: 杂志文章
doi:
更新日期:1987-10-01 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::The main developments in the "ligand assay" field in which I have been involved are traced. These include the original development of "first generation" competitive assays relying on radiolabeled analyte markers; the development of the first "second generation", noncompetitive (ultrasensitive) methods, which rely on t...
journal_title:Clinical chemistry
pub_type: 历史文章,杂志文章
doi:
更新日期:1998-09-01 00:00:00
abstract::We describe a method for measuring apolipoprotein (apo) C distribution between apo B-containing lipoprotein (apo B-LP) and non-apo B-LP. The procedure requires the precipitation of apo B-LP, the redissolution of the pellet, and the quantification of C peptides in the redissolved pellet. The ratio of apo C in non-apo B...
journal_title:Clinical chemistry
pub_type: 杂志文章
doi:
更新日期:1994-02-01 00:00:00
abstract::We describe a rapid, precise, and sensitive radiometric assay for human lactoferrin. In this typical "sandwich"-type assay, anti-human lactoferrin is adsorbed onto a polystyrene sphere and bound lactoferrin is detected by the subsequent binding of 125I-labeled anti-human lactoferrin. The assay is accurate for lactofer...
journal_title:Clinical chemistry
pub_type: 杂志文章
doi:
更新日期:1985-03-01 00:00:00
abstract::We determined fluoxetine (Prozac) and its major metabolite norfluoxetine in plasma by liquid chromatography with fluorescence detection. After liquid-liquid extraction from 1 mL of plasma, the extract was derivatized at room temperature with dansyl chloride, and the highly fluorescent derivatives were chromatographed ...
journal_title:Clinical chemistry
pub_type: 杂志文章
doi:
更新日期:1992-09-01 00:00:00
abstract:BACKGROUND:Quantitative PCR of viral nucleic acids can be useful clinically in diagnosis, risk assessment, and monitoring of antiviral therapy. We wished to develop a chemiluminescence competitive PCR (cPCR) for parvovirus B19. METHODS:Parvovirus DNA target sequences and competitor sequences were coamplified and direc...
journal_title:Clinical chemistry
pub_type: 杂志文章
doi:
更新日期:1999-09-01 00:00:00
abstract::This solid-phase competitive europium immunoassay of progesterone in plasma relies on antigen labeling. With this new approach, time-resolved fluoroimmunoassay can attain sensitivity and precision similar to that of conventional radioimmunoassay. The europium-labeling involves coupling diethylenetriaminepentaacetic ac...
journal_title:Clinical chemistry
pub_type: 杂志文章
doi:
更新日期:1988-03-01 00:00:00
abstract::To produce bispecific antibodies (BiAbs) for enzyme immunoassay (EIA) to replace antibody-enzyme conjugates, we developed a panel of 8-azaguanine/ouabain-resistant anti-urease variant hybridoma cell lines for use in hybridoma-hybridoma fusions. These variants represent mouse immunoglobulin subclasses IgM, IgG1, IgG2a,...
journal_title:Clinical chemistry
pub_type: 杂志文章
doi:
更新日期:1988-09-01 00:00:00
abstract::A method is presented for the assay of delta-aminolaevulinate dehydratase (EC 4.2.1.24) to be performed on 10 microL of whole blood. Results compare favorably with those obtained with an accepted method (J. Clin. Chem. Clin. Bio-chem. 12: 389-390, 1974) that involves use of 200 microL of blood. ...
journal_title:Clinical chemistry
pub_type: 杂志文章
doi:
更新日期:1981-01-01 00:00:00
abstract::A coated microtiter-well, enzyme-linked immunometric assay for quantifying immunoreactive trypsinogen in dried blood spots was modified to use time-resolved fluorescence of europium in place of end-point enzymatic color development as the quantification step. The streptavidin-horseradish peroxidase and color developme...
journal_title:Clinical chemistry
pub_type: 杂志文章
doi:
更新日期:1993-02-01 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::This method for determining aluminum in human serum involves electrothermal atomic absorption spectrophotometry. A longer drying time allows less pre-dilution of the sample, and the method also includes a flush cycle after atomization. Standard-addition methodology is used to eliminate matrix effects and the need for ...
journal_title:Clinical chemistry
pub_type: 杂志文章
doi:
更新日期:1983-06-01 00:00:00
abstract:BACKGROUND:Gas6 is a vitamin K-dependent antiapoptotic protein that has been implicated in cardiovascular pathophysiology. We report the development and validation of an ELISA for Gas6, and the variation of plasma Gas6 with hormonal status in a study designed to evaluate the effect of oral contraception on plasma marke...
journal_title:Clinical chemistry
pub_type: 杂志文章
doi:10.1373/clinchem.2007.089102
更新日期:2007-10-01 00:00:00
abstract:BACKGROUND:Carcinoembryonic antigen (CEA) is one of the most widely used tumor markers worldwide. Its main application is mostly in gastrointestinal cancers, especially in colorectal malignancy. Although in use for almost 30 years, the clinical value of CEA in colorectal cancer is still not clear. METHODS:The literatu...
journal_title:Clinical chemistry
pub_type: 杂志文章,评审
doi:
更新日期:2001-04-01 00:00:00
abstract:BACKGROUND:Total prostate-specific antigen (tPSA) is flawed for prostate cancer (PCa) detection. [-2]proprostate-specific antigen (p2PSA), a molecular isoform of free PSA (fPSA), shows higher specificity compared with tPSA or percentage of free PSA (%fPSA). The prostate health index (Phi), a measure based on p2PSA and ...
journal_title:Clinical chemistry
pub_type: 杂志文章,多中心研究
doi:10.1373/clinchem.2012.195784
更新日期:2013-01-01 00:00:00
abstract::Discrepancies among different methods for assaying human growth hormone have been described in various studies. The two major sources of discordant results are the heterogeneity of the antibodies and the different standardization bases used by the assay manufacturers. We propose standardizing assays with 22-kDa biosyn...
journal_title:Clinical chemistry
pub_type: 杂志文章
doi:
更新日期:1992-10-01 00:00:00
abstract::A new radiometric assay specific for creatine kinase isoenzyme MB was evaluated with respect to its precision and agreement with a conventional electrophoretic CK-MB assay for the diagnosis of myocardial infarction. The reference interval we find for serum CK-MB in healthy subjects is 0--30 micrograms/L. The coefficie...
journal_title:Clinical chemistry
pub_type: 杂志文章
doi:
更新日期:1981-06-01 00:00:00
abstract:INTRODUCTION:Pro or precursor forms of prostate-specific antigen (PSA) have emerged as potentially important diagnostic serum markers for prostate cancer detection. Immunoassays were developed to measure specific proPSA forms containing propeptides of 2, 4, and 7 amino acids [(-2)proPSA, (-4)proPSA, and (-7)proPSA, res...
journal_title:Clinical chemistry
pub_type: 杂志文章
doi:10.1373/clinchem.2003.026823
更新日期:2004-06-01 00:00:00
abstract::We used enzyme immunoassay to measure apolipoprotein B concentration in human plasma. Pure lipoprotein B was isolated from serum samples of fasting normolipidemic subjects by sequential preparative ultracentrifugation and coated to a polystyrene tube surface by adsorption. Human serum samples and rabbit antiserum to h...
journal_title:Clinical chemistry
pub_type: 杂志文章
doi:
更新日期:1978-03-01 00:00:00
abstract::We report the adaptation of four radioassays to the prototype of an automated radioimmunoassay system ("Centria," Union Carbide). The system consists of three integrated modules: (a) an automated pipettor, which dispenses samples and reagents; (b) the key module, an incubator/separator, in which centrifugal force is u...
journal_title:Clinical chemistry
pub_type: 杂志文章
doi:
更新日期:1975-08-01 00:00:00
abstract::Energy-dispersive x-ray spectroscopy and inductively coupled plasma emission spectrometry were evaluated as methods for routine multielement analysis of biological material. Standard samples included Standard Reference Materials (National Bureau of Standards), compounded mixtures, and supplements that provided a wide ...
journal_title:Clinical chemistry
pub_type: 杂志文章
doi:
更新日期:1976-12-01 00:00:00
abstract:BACKGROUND:Functional antibody surfaces were prepared on ultraflat polystyrene surfaces by physical adsorption, and the uniform distribution of monoclonal antibodies against hepatitis B surface antigen (anti-HBs) on such surfaces and the presence of dense hepatitis B surface antigen (HBsAg) particles captured by immobi...
journal_title:Clinical chemistry
pub_type: 杂志文章
doi:
更新日期:2000-09-01 00:00:00
abstract:BACKGROUND:Measurement of serum thyroglobulin (Tg) is used to monitor patients after treatment for differentiated thyroid carcinoma (TC). Difficulty in using Tg as a biomarker of the recurrence of TC in many patients stems from the presence of endogenous anti-Tg autoantibodies (Tg-AAbs), which can interfere with immuno...
journal_title:Clinical chemistry
pub_type: 杂志文章
doi:10.1373/clinchem.2012.195594
更新日期:2013-06-01 00:00:00
abstract:BACKGROUND:Our previously developed assay for detection of the factor V Leiden mutation (G1691A) based on a nucleic acid photo-cross-linking technology used two allele-specific capture probes and six fluorescein-modified signal-generating reporter probes. We wished to improve the sensitivity and performance of the meth...
journal_title:Clinical chemistry
pub_type: 杂志文章
doi:10.1373/clinchem.2003.023556
更新日期:2004-02-01 00:00:00
abstract:BACKGROUND:Proteomic technology permits the investigation of genetic metabolic diseases at the level of protein expression. Changes in the expression, polypeptide structure, and posttranslational modification of individual proteins can be detected in complex mixtures of proteins. METHODS:We used high-resolution two-di...
journal_title:Clinical chemistry
pub_type: 杂志文章
doi:
更新日期:2001-11-01 00:00:00