Abstract:
:We examined the comparative behavior of subject-specific multivariate and univariate reference regions, using both computer-generated data and serial (semi-annual) measurements of selected analytes in subjects from a large health-maintenance program. Univariate studies under both homeostatic and random-walk time-series models were helpful in defining expected results, but only the homeostatic model was used in multivariate as well as univariate forms. Analysis of the computer-generated data and the real biochemical series produced similar findings, which showed the multivariate subject-specific reference region to be much more conservative than corresponding univariate intervals. That is, a multidimensional point of p correlated observations is quite likely to lie within the individual's multivariate reference region (based on past observation vectors), even when one or more of the observations lie outside their separate reference intervals for that individual. One consequence of this high specificity against univariate false positives in a large surveillance program is a higher than expected proportion of positive multivariate vectors in which none of the values lie outside their univariate ranges. Thus, although the development of multivariate reference regions should be encouraged, they should be used in conjunction with, not instead of, univariate ranges.
journal_name
Clin Chemjournal_title
Clinical chemistryauthors
Harris EK,Yasaka T,Horton MR,Shakarji Gsubject
Has Abstractpub_date
1982-03-01 00:00:00pages
422-6issue
3eissn
0009-9147issn
1530-8561journal_volume
28pub_type
杂志文章abstract:BACKGROUND:Increased plasma troponin T (cTnT), but not troponin I (cTnI), is frequently observed in end-stage renal failure patients. Although generally considered spurious, we previously reported an associated increased mortality at 12 months. METHODS:We studied long-term outcomes in 244 patients on chronic hemodialy...
journal_title:Clinical chemistry
pub_type: 杂志文章
doi:
更新日期:2001-03-01 00:00:00
abstract::Liquid scintillation counting of 3H-labeled whole-blood samples is severely impaired owing to quenching by blood pigments. In this study, dry oxidation and chemical solubilization followed by decolorization were the two general methods used to eliminate color quenching. Three blood volumes were examined: 0.25, 0.50, a...
journal_title:Clinical chemistry
pub_type: 杂志文章
doi:
更新日期:1981-04-01 00:00:00
abstract:BACKGROUND:The lead mobilization test reflects the mobilizable and likely toxicologically active fraction of the lead body burden. We propose a safe and convenient protocol for this test, to assess concomitant copper and zinc excretion and to determine the size of the chelatable lead pool in nonoccupationally exposed a...
journal_title:Clinical chemistry
pub_type: 临床试验,杂志文章
doi:10.1373/clinchem.2005.051128
更新日期:2006-01-01 00:00:00
abstract::We compared cardiac troponin I (cTnI), using Access, Sanofi Pasteur, and cardiac troponin T (cTnT), using Elecsys, Boehringer Mannheim, in the first two routine blood samplings in a routine panel of cardiac markers for the biochemical diagnostic evaluation of patients with symptoms of acute myocardial infarction (AMI)...
journal_title:Clinical chemistry
pub_type: 杂志文章
doi:
更新日期:1998-07-01 00:00:00
abstract:BACKGROUND:Prostate-specific antigen (PSA) occurs in serum both free and in complex with protease inhibitors. The complex with alpha1-antichymotrypsin (ACT) is the major form in serum, and the proportion of PSA-ACT is higher in prostate cancer (PCa) than in benign prostatic hyperplasia (BPH). PSA also forms a complex w...
journal_title:Clinical chemistry
pub_type: 临床试验,杂志文章
doi:
更新日期:1999-06-01 00:00:00
abstract::A new, highly sensitive immunoradiometric thyrotropin (TSH) assay involving solid-phase-coupled monoclonal antibodies (Boots-Celltech Sucrosep IRMA-TSH) has been evaluated in a wide variety of patients with thyroidal and nonthyroidal illnesses and the results compared with those obtained by conventional diagnostic TSH...
journal_title:Clinical chemistry
pub_type: 杂志文章
doi:
更新日期:1986-03-01 00:00:00
abstract:BACKGROUND:Buprenorphine is under investigation as a pharmacotherapeutic agent for treating opioid dependence in pregnant women. We hypothesized that there would be a relationship between the cumulative maternal dose of buprenorphine during pregnancy and the concentration of buprenorphine and norbuprenorphine in matern...
journal_title:Clinical chemistry
pub_type: 临床试验,杂志文章
doi:10.1373/clinchem.2007.091413
更新日期:2007-12-01 00:00:00
abstract::For normal and above-normal concentrations of angiotensin-converting enzyme (ACE; EC 3.4.15.1) activity in plasma, results of a manual fluorometric method [with hippuryl-histidyl-leucine (HHL), 5 mmol/L, as substrate] correlated well with those of an automated spectrophotometric method [with 3-(2-furylacryloyl)-L-phen...
journal_title:Clinical chemistry
pub_type: 杂志文章
doi:
更新日期:1991-08-01 00:00:00
abstract::To assess the distribution of serum concentrations of the atherogenic lipoprotein(a) [Lp(a)] in an obese population and the possible effects of weight reduction, we determined Lp(a) in 52 white, moderately obese subjects (16 men and 36 women). The subjects were participating in a weight-reduction program of diet, exer...
journal_title:Clinical chemistry
pub_type: 临床试验,杂志文章
doi:
更新日期:1991-07-01 00:00:00
abstract::Controversy regarding the presence of a circadian rhythm in unconjugated estriol in serum during pregnancy led us to study the possibility that the observed rhythms actually are the result of partitioning of estriol into serum lipids when these increase postprandially. Addition of triglycerides to purified estriol sta...
journal_title:Clinical chemistry
pub_type: 杂志文章
doi:
更新日期:1981-02-01 00:00:00
abstract::We present a rate-determination method for analyzing glucose. A glucose enzyme electrode serves as the sensor and is made by placing a gel-immobilized layer of glucose oxidase over the tip of a Clark-type O2 electrode. The electrode membrane is made of Teflon and is derivatized by etching with a suspension of colloida...
journal_title:Clinical chemistry
pub_type: 杂志文章
doi:
更新日期:1980-01-01 00:00:00
abstract::Patients' sera were analyzed for carbamazepine and ethosuximide by enzyme immunoassay (x) and gas chromatography (y), and the results were compared. The correlation coefficients were: for carbamazepine, x vs. y 0.94 (n = 93); for ethosuximide, x vs. y 0.99 (n = 30). These results suggest that the two methods could be ...
journal_title:Clinical chemistry
pub_type: 杂志文章
doi:
更新日期:1977-09-01 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::To investigate the use of streptavidin-hapten derivatives as potential protein-tracer conjugates for competitive-type immunoassays, we labeled streptavidin with cortisol and compared biotin-binding activity of the conjugates with that of unlabeled streptavidin. In this model system, streptavidin labeled with one to ap...
journal_title:Clinical chemistry
pub_type: 杂志文章
doi:
更新日期:1991-01-01 00:00:00
abstract::Intra-erythrocytic pH, ATP concentrations, and 2,3-diphosphoglycerate relaxation times were studied in living erythrocytes by "high-resolution" 31P NMR spectroscopy to assess homeostasis within the cells. In uremic patients, intra-erythrocytic pH is significantly decreased before hemodialysis, but is corrected equally...
journal_title:Clinical chemistry
pub_type: 杂志文章
doi:
更新日期:1987-01-01 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::Diminished ability to utilize acetate (acetate intolerance) developed in a male patient on chronic hemodialysis after five years of maintenance dialysis. His ability to utilize lactate was also subnormal. We studied acetate metabolism in vitro by isolating lymphocytes from the patient's blood before dialysis and measu...
journal_title:Clinical chemistry
pub_type: 杂志文章
doi:
更新日期:1979-03-01 00:00:00
abstract::We describe radioimmunoassay for human prostatic acid phosphatase [orthophosphoric-monoester phospho-hydrolase (acid optimum), EC 3.1.3.2] in serum, with use of monospecific antisera raised in rabbits against highly purified acid phosphatase from human prostates. The antiserum did not cross react with partly purified ...
journal_title:Clinical chemistry
pub_type: 杂志文章
doi:
更新日期:1978-11-01 00:00:00
abstract::We evaluated a new multiple-channel chemistry analyzer, the Boehringer Mannheim "Diagnostic M." This instrument can perform 25 tests at the rate of 120 1.3-mL serum samples per hour. The instrument may be run in either a profile mode or single-test mode. In the single-test mode only the necessary reagent is pumped. th...
journal_title:Clinical chemistry
pub_type: 杂志文章
doi:
更新日期:1982-01-01 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::We describe a novel radioimmunoassay procedure for the direct estimation of aldosterone in unextracted plasma and serum samples, in which interfering binding proteins are digested by Proteinase K (Tritirachium alkaline proteinase, EC 3.4.21.14), a powerful proteolytic enzyme. Heating at 75 degrees C for 15 min inactiv...
journal_title:Clinical chemistry
pub_type: 杂志文章
doi:
更新日期:1981-12-01 00:00:00
abstract::The ultraviolet fluorescence emission spectra of sera from apparently healthy persons and of sera from cancer patients frequently show significantly different curve shapes. A biparametric fluorescence method has been developed to use these deviations to detect patients with malignant diseases (Clin Chem 1986;32:1974-8...
journal_title:Clinical chemistry
pub_type: 杂志文章
doi:
更新日期:1990-11-01 00:00:00
abstract:BACKGROUND:Paraoxonase may protect lipoproteins and cell membranes from peroxidation, and alterations in the activity of this enzyme have been associated with some chronic diseases. Serum paraoxonase appears to be mainly under genetic control, but some studies suggest that environmental factors may also modulate its ac...
journal_title:Clinical chemistry
pub_type: 杂志文章
doi:10.1373/49.9.1491
更新日期:2003-09-01 00:00:00
abstract::Mycophenolate mofetil, the prodrug form of the immunosuppressive agent mycophenolic acid (MPA), is currently in clinical trials evaluating its effectiveness in transplant recipients. In this study, we validated an ultrafiltration system for the reliable measurement of free MPA. Using this technique, we evaluated facto...
journal_title:Clinical chemistry
pub_type: 杂志文章
doi:
更新日期:1995-07-01 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::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 describe a method used for determining serotonin and tryptamine in urine after oral loading with their precursor amino acid. Several factors affecting prepurification and chromatographic separation of both indoleamines were optimized, including sample extraction and mobile-phase composition. Under optimal condition...
journal_title:Clinical chemistry
pub_type: 杂志文章
doi:
更新日期:1989-01-01 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::To correct the results of a radioimmunoassay for beta-thyrotropin (TSH) subunit by eliminating the proportion ascribable to intact TSH, we have devised a method that experimentally reproduces the conditions under which the interference develops. Beta-TSH subunit was assayed in several preparations containing known con...
journal_title:Clinical chemistry
pub_type: 杂志文章
doi:
更新日期:1987-05-01 00:00:00
abstract::It has been hypothesized over many years that the autoimmune endocrine diseases are each due to antigen-specific defects in suppressor (regulatory) T lymphocyte function. There is now increasing evidence in studies of autoimmune thyroid disease and insulin-dependent diabetes mellitus that suppressor cells are activate...
journal_title:Clinical chemistry
pub_type: 杂志文章,评审
doi:
更新日期:1994-11-01 00:00:00