Abstract：
BACKGROUND:Quantification of 5-hydroxyindole-3-acetic acid (5-HIAA) in urine is useful in diagnosing and monitoring of patients with carcinoid tumors and in the study of serotonin (5-hydroxytryptamine) metabolism in various disorders. We describe an automated method that incorporates on-line solid-phase extraction (SPE) and HPLC to measure urinary 5-HIAA. METHODS:Automated prepurification of urine was accomplished with HySphere-resin GP SPE cartridges containing strong hydrophobic polystyrene resin. The analyte (5-HIAA) and internal standard [5-hydroxyindole-3-carboxylic acid (5-HICA)] were eluted from the SPE cartridge, separated by reversed-phase HPLC, and detected fluorometrically with a total cycle time of 20 min. Urinary excretion of 5-HIAA was measured in a group of patients with known and suspected carcinoid tumors (n=63) and in 20 patients with autism. RESULTS:The internal standard (5-HICA) and 5-HIAA were recovered in high yields (87.2%-114%). Within- and between-series CVs for the measurement of 5-HIAA in urine ranged from 1.2% to 3.9% and 3.2% to 7.6%, respectively. For urine samples from patients with known or suspected carcinoid tumors, results obtained by the automated method were highly correlated (r=0.988) with those from an established manual extraction method. For samples from autistic patients, urinary excretion of 5-HIAA was similar to that reported for healthy individuals. CONCLUSION:This SPE-HPLC method demonstrated lower imprecision and time per analysis than the manual solvent extraction method.
journal_name
Clin Chemjournal_title
Clinical chemistryauthors
Mulder EJ,Oosterloo-Duinkerken A,Anderson GM,De Vries EG,Minderaa RB,Kema IPdoi
10.1373/clinchem.2005.050062subject
Has Abstractpub_date
2005-09-01 00:00:00pages
1698-703issue
9eissn
0009-9147issn
1530-8561pii
clinchem.2005.050062journal_volume
51pub_type
杂志文章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：:Intra- and interindividual components of biological variation have been determined for total thyroxin (TT4), free thyroxin (FT4), total triiodothyronine (TT3), free triiodothyronine (FT3), and thyrotropin (TSH). Calculated analytical goals (CV, %) for the precision required for optimal patient care are: TT4 less than ...
journal_title：Clinical chemistry
pub_type： 杂志文章
doi：
更新日期：1986-06-01 00:00:00
abstract：:We determined approximately 15,000 laboratory values in 236 individuals between the ages of 60 and 90 y, 22 individuals between 90 and 99 y, and 69 individuals greater than or equal to 100 y, and compared these with values in young adults. We tested 47 different analytes in the 60-90-y group and 93 analytes in the gre...
journal_title：Clinical chemistry
pub_type： 杂志文章
doi：
更新日期：1992-06-01 00:00:00
abstract：:We describe a simple, highly reproducible kinetic technique for precisely measuring temperature in spectrophotometric systems having reaction cells that are inaccessible to conventional temperature probes. The method is based on the temperature dependence of pseudo-first-order rate constants for the acid-catalyzed hyd...
journal_title：Clinical chemistry
pub_type： 杂志文章
doi：
更新日期：1981-05-01 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：:Investigating the feasibility and validity of determining plasma ferritin concentration in blood obtained by finger prick, we studied 29 adults (ages 21-49 years) and 35 children (ages 14-66 months). Blood was sampled simultaneously in the same subject from both the antecubital vein (venous blood) and by finger pricki...
journal_title：Clinical chemistry
pub_type： 杂志文章
doi：
更新日期：1983-05-01 00:00:00
abstract：:Use of immunoassays that do not detect endogenous digoxin-like immunoreactive factors (DLIF) in serum significantly improves the between-assay correlation of digoxin results for patients. We investigated five different immunoassay methods (Abbott, Clinical Assays, Corning, Du Pont, and Syva), measuring digoxin by all ...
journal_title：Clinical chemistry
pub_type： 杂志文章
doi：
更新日期：1987-06-01 00:00:00
abstract：:Human myocardial creatine kinase isoenzyme MM is present as a single form in tissue, but upon its release into plasma two additional forms, with faster anodal migration, are apparent on polyacrylamide electrophoresis. We designate the three forms as MM3, MM2, and MM1 in increasing order of anodal mobility. When tissue...
journal_title：Clinical chemistry
pub_type： 杂志文章
doi：
更新日期：1984-05-01 00:00:00
abstract：BACKGROUND:Cardiac troponin T (cTnT) is the preferred biomarker for the diagnosis of acute myocardial infarction (AMI). It has been suggested that cTnT is present predominantly in fragmented forms in human serum following AMI. In this study, we have used a targeted mass spectrometry assay and epitope mapping using West...
journal_title：Clinical chemistry
pub_type： 杂志文章
doi：10.1373/clinchem.2016.261511
更新日期：2017-02-01 00:00:00
abstract：:Hepatitis A virus (HAV) infection occurs worldwide and is an important cause of acute viral hepatitis in the US. In this review, I cover the epidemiology, course of infection, clinical manifestations, serological responses, and prevention of this infection. Although most patients completely recover from this disease, ...
journal_title：Clinical chemistry
pub_type： 杂志文章,评审
doi：
更新日期：1997-08-01 00:00:00
abstract：:Bush and Reed reported (Clin Chem 1987;33:821-3) that the reaction of albumin with bromcresol purple but not with bromcresol green underestimated the concentration of albumin in synthetically obtained bilirubin-albumin (Bd) by 29%. Their unproven assumption was that chemically synthesized Bd behaved in a manner indist...
journal_title：Clinical chemistry
pub_type： 杂志文章
doi：
更新日期：1991-07-01 00:00:00
abstract：:We describe a mechanized method for centrifugal analyzer determination of sorbitol dehydrogenase in serum, based on conversion of D-fructose to sorbitol with simultaneous oxidation of NADH, in triethanolamine buffer at pH 7.4 and 30 degrees C. The standard curve for this assay is linear to 200 U of activity per liter ...
journal_title：Clinical chemistry
pub_type： 杂志文章
doi：
更新日期：1979-12-01 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：:A simple and convenient method using commercially available derivatization reagents is described for the measurement of betaine and N,N-dimethylglycine (DMG) in blood and urine. Precolumn derivatization of plasma or urine is performed directly in acetonitrile without extraction with p-bromophenacyl bromide and crown e...
journal_title：Clinical chemistry
pub_type： 杂志文章
doi：
更新日期：1998-09-01 00:00:00
abstract：:Clinicians experience difficulty in correctly interpreting the results of in vitro thyroid function tests in the presence of abnormalities of thyrobinding proteins or when results are borderline. This difficulty has been largely resolved in our laboratory by three innovations. First, the borderline areas for each of t...
journal_title：Clinical chemistry
pub_type： 杂志文章
doi：
更新日期：1976-10-01 00:00:00
abstract：BACKGROUND:Advances in the biological sciences and technology are providing molecular targets for diagnosing and treating cancer. Current classifications in surgical pathology for staging malignancies are based primarily on anatomic features (e.g., tumor-node-metastasis) and histopathology (e.g., grade). Microarrays to...
journal_title：Clinical chemistry
pub_type： 杂志文章,评审
doi：
更新日期：2002-08-01 00:00:00
abstract：:Four routine assays commonly used for monitoring plasma methotrexate (MTX) during high-dose therapy were validated by HPLC as the comparison method. MTX and its main metabolite, 7-hydroxymethotrexate (7-OHMTX), were analyzed by HPLC with postcolumn derivatization and fluorometric detection. About 200 clinical plasma s...
journal_title：Clinical chemistry
pub_type： 杂志文章
doi：
更新日期：1996-01-01 00:00:00
abstract：:We measured the free amino acids in plasma of 58 patients with HIV infection and in six persons in the risk group. The HIV+ patients had significantly increased concentrations of arginine, phenylalanine, and glutamate in comparison with both age- and sex-matched controls and the members of the risk group. Glutamate co...
journal_title：Clinical chemistry
pub_type： 杂志文章
doi：
更新日期：1988-09-01 00:00:00
abstract：BACKGROUND:The susceptibility of plasma lipids to oxidation is thought to be a factor contributing to atherogenic risk. Various groups have studied the in vitro oxidizability of isolated LDL and examined the effects of conventional antioxidants. The drawbacks associated with the isolation of LDL for evaluation of in vi...
journal_title：Clinical chemistry
pub_type： 杂志文章
doi：10.1373/clinchem.2005.051078
更新日期：2005-11-01 00:00:00
abstract：:Cardiac troponin I (cTnI) is a regulatory protein unique to myocardium. We used a cardiospecific 30-min ELISA to measure cTnI in EDTA-plasma samples serially drawn from 28 patients before and after coronary artery bypass grafting (CABG)--26 elective and 2 salvage cases. The cTnI increase in 22 of the elective CABG pat...
journal_title：Clinical chemistry
pub_type： 杂志文章
doi：
更新日期：1994-11-01 00:00:00
abstract：:The values of apolipoproteins (apo) A-I and B were determined in a population sample of hospital outpatients with a standardized method to verify if the cutpoints calculated in a cross-sectional study in the US are usable with other populations. We also tested the apolipoproteins' ability to discriminate between healt...
journal_title：Clinical chemistry
pub_type： 杂志文章
doi：
更新日期：1998-01-01 00:00:00
abstract：BACKGROUND:Although it is being increasingly applied, blood collection for drug testing in sport presents some logistic issues that complicate full applicability on a large scale. The use of dried blood spots (DBS) could benefit compliant blood testing considerably owing to its simplicity, minimal invasiveness, analyte...
journal_title：Clinical chemistry
pub_type： 杂志文章
doi：10.1373/clinchem.2016.257592
更新日期：2016-10-01 00:00:00
abstract：:The technology needed to genetically engineer antibodies is evolving rapidly and the potential utility of these novel reagents is being explored with vigor. The process includes cloning of the antibody genes, their in vitro manipulation and mutagenesis, expression in a suitable host/vector system, and, for commercial ...
journal_title：Clinical chemistry
pub_type： 杂志文章,评审
doi：
更新日期：1989-09-01 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：:We evaluated the density-gradient ultracentrifugation method in a swinging-bucket rotor (Anal Biochem 111, 149-157, 1981) in a slightly modified version for isolation and determination of high-density lipoprotein (HDL) subfractions. We prestained the serum with Coomassie Brilliant Blue R, which did not change the hydr...
journal_title：Clinical chemistry
pub_type： 杂志文章
doi：
更新日期：1983-04-01 00:00:00
abstract：:Total protein (TP), albumin (Alb), transferrin (TRF), retinol-binding protein (RPB), N-acetyl-beta-glucosaminidase (NAG), alanine aminopeptidase (AAP), gamma-glutamyltransferase (GGT), and creatinine (Cr) were measured in random (untimed) urine samples from 29 nonpregnant women and from pregnant subjects (11 in the fi...
journal_title：Clinical chemistry
pub_type： 杂志文章
doi：
更新日期：1989-09-01 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：:Carbohydrate-deficient transferrin (CDT) may now be the most valuable biological marker for diagnosis of alcohol abuse. We compared the diagnostic performance of two new CDT tests, Axis %CDT turbidimetric immunoassay (TIA) and Axis %CDT HPLC, against Specialty Laboratories' isoelectric focusing/immunoblotting/laser de...
journal_title：Clinical chemistry
pub_type： 临床试验,杂志文章
doi：
更新日期：1997-06-01 00:00:00
abstract：:The immunoreactivity of anti-triiodothyronine (anti-T3) IgG, pretreated at acidic pH and adsorbed onto polystyrene beads, was significantly greater than that determined for native anti-T3 IgG immobilized at optimum pH 3.5. Acidic-pH-pretreated IgG, adsorbed at pH 7.0 onto ethanol-treated beads, had less immunoreactivi...
journal_title：Clinical chemistry
pub_type： 杂志文章
doi：
更新日期：1990-03-01 00:00:00
abstract：BACKGROUND:Different technologies, such as quantitative real-time PCR or microarrays, have been developed to measure microRNA (miRNA) expression levels. Quantification of miRNA transcripts implicates data normalization using endogenous and exogenous reference genes for data correction. However, there is no consensus ab...
journal_title：Clinical chemistry
pub_type： 杂志文章,评审
doi：10.1373/clinchem.2015.239459
更新日期：2015-11-01 00:00:00
