Abstract：
:o-Phthaldialdehdye reagent was used in assaying urea with a miniature centrifugal analyzer. Seventeen samples can be assayed kinetically in 2 min at a current cost of less than a penny per test. The reaction is initiated in the instrument upon simultaneous mixing of the o-phthaldialdehyde reagent containing 10 microliter of sample with dilute sulfuric acid/N-(1-naphthyl)ethylenediamine dihydrochloride reagent. The reaction is monitored kinetically at 546 nm during the initial 2 min, when the rate is nearly constant. The reaction of o-phthaldialdehyde with urea reaches equilibrium by about 7 or 8 min, but the method cannot be used for end-point analysis because of interference by the blank reaction. A 1.2 g/liter solution of o-phthaldialdehyde used in conjunction with 2 mol/liter sulfuric acid solution was found to be most suitable for centrifugal analyzers. I also describe a manual version of the procedure that gives a linear standard curve up to 1.0 g of urea nitrogen per liter.
journal_name
Clin Chemjournal_title
Clinical chemistryauthors
Levinson SSsubject
Has Abstractpub_date
1978-12-01 00:00:00pages
2199-202issue
12eissn
0009-9147issn
1530-8561journal_volume
24pub_type
杂志文章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：:To clarify whether manganese nutritional status is better reflected by the manganese concentration in lymphocytes or in whole blood, we injected manganese solutions intravenously into manganese-deficient rats and determined manganese concentrations in lymphocytes, whole blood, and various tissues. The manganese concen...
journal_title：Clinical chemistry
pub_type： 杂志文章
doi：
更新日期：1989-09-01 00:00:00
abstract：:We describe a fully automated method of analysis for plasma epinephrine and norepinephrine by use of a two-column system of "high-performance" liquid chromatography. Catecholamines in deproteinized plasma are purified on the first (preparation) column, then transferred automatically to the second (analytical) column i...
journal_title：Clinical chemistry
pub_type： 杂志文章
doi：
更新日期：1981-12-01 00:00:00
abstract：:We measured three renal tubular brush-border enzymes (lactate dehydrogenase, LDH, EC 1.1.1.27; gamma-glutamyltransferase, GGT, EC 2.3.2.2; and alkaline phosphatase, AP, EC 3.1.3.1) in morning urine samples from 48 healthy subjects to check whether different storage times and temperatures could modify enzyme concentrat...
journal_title：Clinical chemistry
pub_type： 杂志文章
doi：
更新日期：1991-08-01 00:00:00
abstract：:Brain proteins extractable with distilled water or 9 mol/L urea were subjected to two-dimensional gel electrophoresis. They are examined in relation to the identification of actin, tubulin, neurofilament proteins, glial fibrillary acidic protein; proteins of human embryonic neocortex, synaptosomes, myelin, and plasma;...
journal_title：Clinical chemistry
pub_type： 杂志文章
doi：
更新日期：1982-04-01 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：BACKGROUND:It has been postulated that changes in S-adenosylhomocysteine (AdoHcy), a potent inhibitor of transmethylation, provide a mechanism by which increased homocysteine causes its detrimental effects. We aimed to develop a rapid and sensitive method to measure AdoHcy and its precursor S-adenosylmethionine (AdoMet...
journal_title：Clinical chemistry
pub_type： 杂志文章
doi：10.1373/clinchem.2004.046995
更新日期：2005-08-01 00:00:00
abstract：:We compared a stabilized-temperature L'vov platform furnace containing an end-heated graphite atomizer (HGA) and transverse Zeeman background-correction system with a side-heated furnace system (transversely heated graphite atomizer; THGA) containing a longitudinal Zeeman background-correction system for the determina...
journal_title：Clinical chemistry
pub_type： 杂志文章
doi：
更新日期：1994-03-01 00:00:00
abstract：:Estrogen receptor (ER) and progestin receptor (PR) concentrations in tumor biopsies are important predictive indicators of a clinical response to endocrine therapy of breast cancer. To assess interference of O.C.T. (optimum cutting temperature) embedding compound in assays of ER and PR by radioligand binding, we deter...
journal_title：Clinical chemistry
pub_type： 杂志文章
doi：
更新日期：1989-12-01 00:00:00
abstract：BACKGROUND:The current diagnosis and monitoring of bladder cancer are heavily reliant on cystoscopy, an invasive and costly procedure. Previous efforts in urine-based detection of bladder cancer focused on targeted approaches that are predicated on the tumor expressing specific aberrations. We aimed to noninvasively de...
journal_title：Clinical chemistry
pub_type： 杂志文章
doi：10.1373/clinchem.2018.301341
更新日期：2019-07-01 00:00:00
abstract：:In this paper, we present initial quality-control evaluations for a prototype clinical laboratory, recommendations for clinical and technical data record-keeping, and laboratory protocols designed to minimize operator-dependent analytical error in a multi-user environment. These evaluations and recommendations are bas...
journal_title：Clinical chemistry
pub_type： 杂志文章
doi：
更新日期：1984-12-01 00:00:00
abstract：:We assessed the performance of three commercially available polyclonal immunoassays for apparent cyclosporine in 120 whole-blood specimens collected from transplant recipients just before their next dose of cyclosporine (CsA). The assays were (a) Abbott's TDx fluorescent polarization immunoassay for CsA and its metabo...
journal_title：Clinical chemistry
pub_type： 杂志文章
doi：
更新日期：1990-01-01 00:00:00
abstract：:Measurement of the mass concentration of serum enzymes by radioimmunoassay provides direct quantitation of specific isoenzymes and may be less subject to some of the limitations of traditional assay procedures for enzymes. We describe the development of a sensitive and specific radioimmunoassay for the muscle isoenzym...
journal_title：Clinical chemistry
pub_type： 杂志文章
doi：
更新日期：1978-03-01 00:00:00
abstract：:Purified arylsulfatase A (EC 3.1.6.1) from human urine was radioiodinated under conditions that caused no significant loss of antigenic activity. We used this labeled arylsulfatase A (specific radioactivity 4-7.5 Ci/g) together with nonlabeled enzyme and rabbit antiserum produced against homogeneous enzyme to develop ...
journal_title：Clinical chemistry
pub_type： 杂志文章
doi：
更新日期：1985-03-01 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：:To determine the molar absorptivities of beta-NADH and beta-NAD at 260 nm, we purified the reduced form of the coenzyme by repeated anion-exchange chromatography. A NADH preparation was so obtained for which the 260 nm/340 nm absorbance ratio was 2.265. When calculated with epsilon 340 beta-NADH = 6.22 times 10-3 for ...
journal_title：Clinical chemistry
pub_type： 杂志文章
doi：
更新日期：1975-06-01 00:00:00
abstract：:A potential genetic marker for hypertriglyceridemia and coronary disease, an apolipoprotein-CIII gene allele displaying a single nucleotide substitution, was found in 71% of Arabs with primary hypertriglyceridemia. Over 96% of the unrelated adults possessing this allele showed hypertriglyceridemia. The same allele was...
journal_title：Clinical chemistry
pub_type： 杂志文章
doi：
更新日期：1989-02-01 00:00:00
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 protein...
journal_title：Clinical chemistry
pub_type： 杂志文章
doi：
更新日期：1997-10-01 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 procedure for measuring dialyzable calcium in 60 sera per hour with use of AutoAnalyzer (Technicon) modules. The serum is buffered, then dialyzed in a regular 6-inch (15-cm) dialysis block. A constant proportion of the dialyzable calcium is fluorometrically measured. Analysis of samples containing protei...
journal_title：Clinical chemistry
pub_type： 杂志文章
doi：
更新日期：1977-07-01 00:00:00
abstract：:To compare six assays of hyaluronan (hyaluronic acid; HYA) in serum, developed in different laboratories, we analyzed 10 samples from each of three groups: healthy persons, patients with primary biliary cirrhosis, and patients with rheumatoid arthritis. All the assays are based on the use of affinity proteins specific...
journal_title：Clinical chemistry
pub_type： 杂志文章
doi：
更新日期：1992-01-01 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：:The core antigen component of hepatitis B virus (HBV), HBcAg, may be used as a marker of viral replication. We describe a radioimmunoassay for HBcAg in serum, and compare results with those by other similar methods. Samples are centrifuged over a sucrose gradient containing 2-mercaptoethanol, and the resulting pellets...
journal_title：Clinical chemistry
pub_type： 杂志文章
doi：
更新日期：1985-06-01 00:00:00
abstract：BACKGROUND:The resurgence of the parasitic disease schistosomiasis calls for more efficient diagnostic tests. We developed a rapid, simple, portable, and sensitive immunoagglutination assay that uses SiO(2) particles and quartz crystal microbalance (QCM) for quantifying Schistosoma japonicum (Sj) antibodies (SjAb). ME...
journal_title：Clinical chemistry
pub_type： 杂志文章
doi：10.1373/clinchem.2006.071555
更新日期：2006-11-01 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
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：:alpha 1-Antitrypsin (A1AT) deficiency is a relatively common autosomal recessive disease, resulting most often from a single base pair (1 bp) substitution called the Z mutation. Previous genetic tests for carriers and affected patients have relied on quantitative binding of radioactive probes to an amplified gene prod...
journal_title：Clinical chemistry
pub_type： 杂志文章
doi：
更新日期：1992-08-01 00:00:00
abstract：:We describe a method for measuring urinary oxalate and citrate with capillary electrophoresis (CE) and indirect ultraviolet absorbance detection. Sample preparation is minimal, requiring an acidification, brief centrifugation, and dilution. The method is rapid, with oxalate and citrate having mean migration times of 4...
journal_title：Clinical chemistry
pub_type： 杂志文章
doi：
更新日期：1995-09-01 00:00:00
abstract：:This semi-automated colorimetric assay for the MB isoenzyme of creatine kinase (EC 2.7.3.2) is based on a monoclonal antibody ("Conan-MB") specific for this isoenzyme and is a modification of a previously published method (Vaidya et al., Clin Chem 1986;32:657-63). A 0.64-cm bead coated with 2 to 3 micrograms of antibo...
journal_title：Clinical chemistry
pub_type： 杂志文章
doi：
更新日期：1988-03-01 00:00:00
abstract：:The fructosamine test is considered clinically useful for assessing short-term integrated control of blood glucose, but there are few published data to support this hypothesis. We fractionated glycated and nonglycated proteins by affinity chromatography on phenylboronate columns and, with specific immunochemical metho...
journal_title：Clinical chemistry
pub_type： 杂志文章
doi：
更新日期：1987-10-01 00:00:00
