Abstract:
:A simple, precise, and rapid method to measure plasma malondialdehyde (MDA) was developed by use of solvent extraction--flow-injection analysis. The reagent solution, containing thiobarbituric acid (TBA), 5 g/L in 100 mL/L phosphoric acid, and extraction solvent (methylisobutyl ketone, MIBK) were propelled with a double-plunger micropump at a flow rate of 0.3 mL/min, and 20 microL of sample was introduced into the reagent stream. After TBA-MDA reactant was extracted into MIBK, the organic phase was continuously separated by a successive phase-separation system equipped with two phase separators, and the absorbance of the TBA-MDA reactant was measured at 532 nm. This approach resulted in excellent sensitivity, a CV of < 1.5%, a good correlation with the conventional manual method, and a sampling frequency of 7 samples/h, suggesting that this semiautomated method is suitable for measuring plasma MDA.
journal_name
Clin Chemjournal_title
Clinical chemistryauthors
Ikatsu H,Nakajima T,Murayama N,Korenaga Tsubject
Has Abstractpub_date
1992-10-01 00:00:00pages
2061-5issue
10eissn
0009-9147issn
1530-8561journal_volume
38pub_type
杂志文章abstract:BACKGROUND:In the workup of patients with suspected hereditary nonpolyposis colorectal cancer (HNPCC), detection of loss of heterozygosity (LOH) could help pinpoint the mismatch-repair (MMR) gene carrying the germline mutation, but analysis of microsatellite markers has proved unreliable for this purpose. We developed ...
journal_title:Clinical chemistry
pub_type: 杂志文章
doi:10.1373/clinchem.2008.108902
更新日期:2008-11-01 00:00:00
abstract::A reaction of urea, o-phthalaldehyde and N-(1-naphthyl)ethylenediamine is described for measurement of urea by manual, continuous-flow, and kinetic methods. The continuous-flow system requires 25 mu-l of sample; 40 samples can be analyzed per hour. The kinetic method requires no enzymes, has no lag phase, and has good...
journal_title:Clinical chemistry
pub_type: 杂志文章
doi:
更新日期:1975-07-01 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::We analyzed pancreatic enzyme data from 508 patients with suspected pancreatitis by neural network analysis, by an Expert multirule generation protocol, and by receiver-operator characteristic (ROC) curve analysis of a single test result. Neural network analysis showed that use of lipase provided the best means for di...
journal_title:Clinical chemistry
pub_type: 杂志文章
doi:
更新日期:1993-09-01 00:00:00
abstract:BACKGROUND:The use of nonstandardized N-terminal pro-B-type natriuretic peptide (NT-proBNP) assays can contribute to the misdiagnosis of heart failure (HF). Moreover, there is yet to be established a common consensus regarding the circulating forms of NT-proBNP being used in current assays. We aimed to characterize and...
journal_title:Clinical chemistry
pub_type: 杂志文章
doi:10.1373/clinchem.2012.200204
更新日期:2013-10-01 00:00:00
abstract::We describe the interlaboratory testing of a candidate Reference Method (Part I) for uric acid in serum. The method is based on the ultrasound spectrophotometric quantitation of uric acid before and after incubation with uricase. A comprehensive investigation involving 12 laboratories was organized to document the tra...
journal_title:Clinical chemistry
pub_type: 杂志文章
doi:
更新日期:1982-02-01 00:00:00
abstract:BACKGROUND:Plasma B-type cardiac natriuretic peptides reflect cardiac structure and function and have proven roles in assisting in the diagnosis of acute heart failure. They are independent prognostic indicators across the full spectrum of cardiovascular disease. Serial changes in plasma B-type cardiac natriuretic pept...
journal_title:Clinical chemistry
pub_type: 杂志文章,评审
doi:10.1373/clinchem.2011.165704
更新日期:2012-01-01 00:00:00
abstract::We describe an improved enzymatic ultraviolet absorbance method for assaying creatinine in serum, plasma, and urine. Creatinine is hydrolyzed by creatinine iminohydrolase (EC 3.5.4.21) to ammonia and N-methylhydantoin. The ammonia produced combines with 2-oxoglutarate and NADPH in the presence of glutamate dehydrogena...
journal_title:Clinical chemistry
pub_type: 杂志文章
doi:
更新日期:1994-01-01 00:00:00
abstract::We compared measurements of apoprotein A-I (apoA-I) in plasma and in heparin-MnCl2 supernates analyzed by radial immunodiffusion. The apoA-I values were similar when the samples were fresh [n = 41, mean (SD), mg/L: plasma, 1393.4(349); heparin-MnCl2 supernates, 1364.9(332), p less than 0.01], but were greater than 8% ...
journal_title:Clinical chemistry
pub_type: 杂志文章
doi:
更新日期:1986-06-01 00:00:00
abstract::Ornithine carbamoyltransferase (EC 2.1.3.3) activity is a sensitive, specific indicator of hepatocellular injury. This paper describes development of an improved automated procedure for measurement of this activity. Triethanolamine-ethylenediaminetetraacetate is used as a buffer, and activity is determined by measurin...
journal_title:Clinical chemistry
pub_type: 杂志文章
doi:
更新日期:1975-05-01 00:00:00
abstract::This enzyme immunoassay procedure for pregnancy-associated plasma protein type A involves a "sandwich"-type system in microtitration plates. One can detect 0.27 mg of the protein per liter of serum, with a between-batch CV of 10.2%, and the antiserum used does not cross react with any of the other placentally derived ...
journal_title:Clinical chemistry
pub_type: 杂志文章
doi:
更新日期:1984-11-01 00:00:00
abstract::9-(2-Phosphonylmethoxyethyl)adenine (PMEA), (S)-9-(3-hydroxy-2-phosphonylmethoxypropyl)adenine (HPMPA), and (R,S)-9-(3-fluoro-2-phosphonylmethoxypropyl)adenine (FPMPA) are selective antiviral agents with activity against a broad spectrum of DNA viruses and retroviruses. A highly sensitive method has been developed to ...
journal_title:Clinical chemistry
pub_type: 杂志文章
doi:
更新日期:1992-04-01 00:00:00
abstract::We report a continuous-flow fluorometric method for total urinary estrogens that involves the Kober reaction, with extraction of the reaction product into dichloroethane containing trichloroacetic acid as described by Hahnel and Jones [Clin. Chim. Acta 16, 185 (1967)]. The dichloroethane extraction gives greater stabi...
journal_title:Clinical chemistry
pub_type: 杂志文章
doi:
更新日期:1977-10-01 00:00:00
abstract::Using different substance concentrations in an aqueous 1.25 mmol/L solution of CaCl2 plus NaCl to a final solution ionic strength of 160 mmol/L, we tested six buffers for their effect on measurements of ionized calcium (Ca2+). Measured Ca2+ decreased with increasing ionic strength and pH. Increasing concentrations of ...
journal_title:Clinical chemistry
pub_type: 杂志文章
doi:
更新日期:1985-02-01 00:00:00
abstract::We present a comparative evaluation of two commercial kits, the "Quantitope" and "GammaCoat," for radioimmunoassay of digoxin in serum. These kits, in which iodine-125 is used as a label, proved to suitable for digoxin assay as determined by their reproducibility, sensitivity, precision, and a regression analysis. Hem...
journal_title:Clinical chemistry
pub_type: 杂志文章
doi:
更新日期:1976-02-01 00:00:00
abstract:BACKGROUND:Urinary cross-linked N-telopeptide of type I collagen (NTX) is a reliable bone resorption marker in patients with metabolic bone disease. We assessed a clinically available serum NTX assay suitable for anuric patients on hemodialysis (HD). METHODS:Serum concentrations of NTX, C-terminal telopeptide of type ...
journal_title:Clinical chemistry
pub_type: 杂志文章
doi:10.1373/clinchem.2005.051524
更新日期:2005-12-01 00:00:00
abstract:BACKGROUND:Measurements of the ionic current flowing through nanometer-scale pores (nanopores) have been used to analyze single DNA and RNA molecules, with the ultimate goal of achieving ultrafast DNA sequencing. However, attempts at purely electronic measurements have not achieved the signal contrast required for sing...
journal_title:Clinical chemistry
pub_type: 杂志文章
doi:10.1373/clinchem.2007.091231
更新日期:2007-11-01 00:00:00
abstract::Determination of the MB isoenzyme of creatine kinase in patients with acute myocardial infarction may be disturbed by the presence of macro creatine kinase. The relative molecular mass of this form of creatine kinase in human serum is at least threefold that of the ordinary enzyme, and it is more thermostable. Here we...
journal_title:Clinical chemistry
pub_type: 杂志文章
doi:
更新日期:1982-01-01 00:00:00
abstract::We describe an enzyme-linked two-site immunoassay for quantitation of intact insulin in human serum and plasma. The method uses two murine monoclonal antibodies that bind to two different epitopes on the insulin molecule. The immunoassay is specific. Human proinsulin is not bound by the antibodies, and the binding of ...
journal_title:Clinical chemistry
pub_type: 杂志文章
doi:
更新日期:1993-04-01 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::We report the kinetics of the reactions of unconjugated bilirubin and conjugated bilirubin with p-diazobenzene sulfonic acid in aqueous media. Our studies confirm that each reaction proceeds in two steps and that the second step is catalyzed by sulfanilic acid. In the presence of an excess of p-diazobenzenesulfonic ac...
journal_title:Clinical chemistry
pub_type: 杂志文章
doi:
更新日期:1978-10-01 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::This paper reviews our ability to predict survival and neurodevelopmental outcome in the newborn period. Traditionally, prognosis is based on individual risk factors or disease states. The laboratory plays an important role in diagnosing some of these. For example, prenatal and newborn screening are important in the d...
journal_title:Clinical chemistry
pub_type: 杂志文章,评审
doi:
更新日期:1997-01-01 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:BACKGROUND:Direct equilibrium dialysis and direct ultrafiltration free thyroxine (T(4)) assays rely on semipermeable membranes to exclude T(4)-binding serum proteins from dialysates and ultrafiltrates. The presence of these proteins in dialysates or ultrafiltrates will yield spuriously high free T(4) values when free T...
journal_title:Clinical chemistry
pub_type: 杂志文章
doi:10.1373/clinchem.2007.085316
更新日期:2007-05-01 00:00:00
abstract::Demonstrable quality of laboratory services entails two parts. First, one needs a quality policy statement, identification of user needs, choice of measurement procedures, reference measurement system to provide traceability, control materials, and proficiency testing with materials having reference-measurement-assign...
journal_title:Clinical chemistry
pub_type: 杂志文章,评审
doi:
更新日期:1994-07-01 00:00:00
abstract::Problems encountered in the uroporphyrinogen I synthase assay were found to be due to the Triton reagent, slit-width and excitation wavelength settings of the spectrophotofluorometer, and leg-phase in the enzyme reaction. Of Triton X-100 from four suppliers, only three were found suitable. Differences in enzyme activi...
journal_title:Clinical chemistry
pub_type: 杂志文章
doi:
更新日期:1980-08-01 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::Measurement of colloid osmotic pressure complements measurements of pulmonary artery wedge pressure for assessing the risks of pulmonary edema and constitutes an increasingly important reference for purposes of guiding selection of colloid or crystalloid fluids in patients with acute cardiac disease. We describe a sim...
journal_title:Clinical chemistry
pub_type: 杂志文章
doi:
更新日期:1978-09-01 00:00:00
abstract::We report the intermediate-term effects of three consecutive evenings of moderate ethanol ingestion (0.75 g/kg body weight each evening) on activity values for alkaline phosphatase, gamma-glutamyltransferase, creatine kinase, aspartate aminotransferase, alanine aminotransferase, and lactate dehydrogenase in sera of ni...
journal_title:Clinical chemistry
pub_type: 杂志文章
doi:
更新日期:1977-05-01 00:00:00