Abstract:
:A literature review of the effects of long-term freezer storage on concentrations of antioxidant micronutrients in serum or plasma showed that a high proportion of the studies that compared the concentrations of retinol, beta-carotene, or alpha-tocopherol in fresh and stored serum were deficient because of small numbers of observations, imprecise descriptions of procedures, and short periods of storage. Data from nested case-control studies of the associations of these micronutrients with cancer are confounded by differences in the study populations. Nevertheless, the overall impression is strong that retinol is stable at storage temperatures as warm as -20 degrees C for at least 15 years, that moderate losses of alpha-tocopherol occur at temperatures above -40 degrees C during that period, and that only a small proportion of beta-carotene persists at storage temperatures above -40 degrees C. At -70 degrees C or colder, all three micronutrients appear to be stable for at least 15 years.
journal_name
Clin Chemjournal_title
Clinical chemistryauthors
Comstock GW,Alberg AJ,Helzlsouer KJsubject
Has Abstractpub_date
1993-06-01 00:00:00pages
1075-8issue
6eissn
0009-9147issn
1530-8561journal_volume
39pub_type
杂志文章abstract::As the domain of monitoring therapeutic drugs rapidly expands from experimental investigations to everyday patient care, all clinical laboratory scientists, but especially clinical chemists, must learn to deal with their involvement in this expansion. First, the theoretical concepts underlying clinical pharmacology mu...
journal_title:Clinical chemistry
pub_type: 杂志文章
doi:
更新日期:1975-09-01 00:00:00
abstract::HbCO in blood sampled from 20 mothers and newborns immediately after birth was measured with a new, simple gas-chromatographic method for CO. The mean ratio of HbCO to total hemoglobin for 13 non-smoking mothers did not differ significantly from that for their infants (mean 0.38%, SD 0.26% vs 0.38%, SD 0.13%), but the...
journal_title:Clinical chemistry
pub_type: 杂志文章
doi:
更新日期:1988-01-01 00:00:00
abstract::We present evidence for the utility of an improved assay for the activity of lactate dehydrogenase (EC 1.1.1.27) isoenzymes 1 and 2 in serum, involving inhibition of the H-subunit of LD by pyruvate at pH 7.1. Results correlate well with the LD-1/total LD ratio as evaluated by immunological assay and, as an index to in...
journal_title:Clinical chemistry
pub_type: 杂志文章
doi:
更新日期:1986-05-01 00:00:00
abstract::We developed a fluorometric method for determining delta-aminolevulinic acid (ALA) in urine of lead workers. A high-performance liquid chromatograph (HPLC) equipped with a fluorescence HPLC monitor is used. The detection limit for aqueous ALA is 20 micrograms/L (15 pmol of ALA in the 100-microL sample). The working li...
journal_title:Clinical chemistry
pub_type: 杂志文章
doi:
更新日期:1987-09-01 00:00:00
abstract:BACKGROUND:Uremic syndrome is the consequence of the retention of solutes usually cleared by the healthy kidneys. p-Cresol can be considered a prototypic protein-bound uremic toxin. It is conceivable, analogous with drugs, that the non-protein-bound fraction of p-cresol exerts toxicity. This aspect had never been evalu...
journal_title:Clinical chemistry
pub_type: 杂志文章
doi:10.1373/49.3.470
更新日期:2003-03-01 00:00:00
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journal_title:Clinical chemistry
pub_type: 杂志文章
doi:
更新日期:1981-01-01 00:00:00
abstract::Apoprotein (apo) C-I, C-II, and C-III were measured in plasma from 35 white American non-diabetic subjects. The mean concentrations (mg/L) in plasma from normolipidemic and hypertriglyceridemic subjects, respectively, were apo C-I, 78 and 311; apo C-II, 37 and 200; and apo C-III, 98 and 529. These concentrations were ...
journal_title:Clinical chemistry
pub_type: 杂志文章
doi:
更新日期:1986-10-01 00:00:00
abstract:BACKGROUND:It is important that cardiac troponin be measured accurately with a robust method to limit false results with potentially adverse clinical outcomes. In this study, we characterized the robustness of 4 analytical platforms by measuring the outlier rate between duplicate results. METHODS:We measured cardiac t...
journal_title:Clinical chemistry
pub_type: 杂志文章
doi:10.1373/clinchem.2010.159830
更新日期:2011-05-01 00:00:00
abstract::The effect of serum-clot contact time on laboratory results was studied by dividing each blood specimen into four blood collection tubes. The control sera were separated from the clot within 30 min of the collection. The other tubes were incubated at 32 degrees C, and the sera were separated at 3, 6, and 24 h. The ser...
journal_title:Clinical chemistry
pub_type: 杂志文章
doi:
更新日期:1998-06-01 00:00:00
abstract:BACKGROUND:The liver is frequently subject to insult because of viral infection, alcohol abuse, or toxic chemical exposure. Extensive research has been conducted to identify blood markers that can better discern liver damage, but little progress has been achieved in clinical practice. Recently, circulating microRNAs (m...
journal_title:Clinical chemistry
pub_type: 杂志文章
doi:10.1373/clinchem.2010.147850
更新日期:2010-12-01 00:00:00
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journal_title:Clinical chemistry
pub_type: 杂志文章
doi:
更新日期:1991-12-01 00:00:00
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...
journal_title:Clinical chemistry
pub_type: 杂志文章
doi:10.1373/clinchem.2005.050062
更新日期:2005-09-01 00:00:00
abstract:BACKGROUND:The thiopurine S:-methyltransferase (TPMT) genetic polymorphism has a significant clinical impact on the toxicity of thiopurine drugs, which are used in the treatment of leukemia and as immunosuppressants. To date, 10 mutant alleles are known that are associated with intermediate or low TPMT activity. To fac...
journal_title:Clinical chemistry
pub_type: 杂志文章
doi:
更新日期:2001-03-01 00:00:00
abstract::We studied 25 borderline-hyperparathyroidism patients whose total serum calcium concentration was within normal limits (reference range: 2.25--2.75 mmol/liter) but whose concentrations of serum ionized calcium were above normal (reference range: 1.03--1.23 mmol/liter). Their hyperparathyroidism was histopathologically...
journal_title:Clinical chemistry
pub_type: 杂志文章
doi:
更新日期:1978-11-01 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::We recently proposed a quantitative PCR procedure for the absolute measurement of c-erbB-2 oncogene amplification, based on the simultaneous polymerase chain reaction (PCR) amplification of the target gene and of a competitor DNA molecule acting as internal standard. To increase the number of assayable oncogenes and t...
journal_title:Clinical chemistry
pub_type: 杂志文章
doi:
更新日期:1995-06-01 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::Five genetic defects have been established as risk factors for venous thrombosis. Three are protein C, protein S, and antithrombin deficiencies, defects in the anticoagulant pathways of blood coagulation. Together they can be found in approximately 15% of families with inherited thrombophilia. Their laboratory diagnos...
journal_title:Clinical chemistry
pub_type: 杂志文章,评审
doi:
更新日期:1997-09-01 00:00:00
abstract::We have studied the influence of triglyceride-rich particles on the analytical bias of apolipoprotein B measurements by various immunoturbidimetric methods. Three commercially available methods grossly overestimate apolipoprotein B in samples with even moderately above-normal triglyceride concentrations. This effect i...
journal_title:Clinical chemistry
pub_type: 杂志文章
doi:
更新日期:1991-05-01 00:00:00
abstract::A sensitive, specific, and simple method for determining serum or urine arylesterase (EC 3.1.1.2) is described. The enzyme acts on phenyl acetate to release phenol, which produces a stable indophenol dye with 4-aminoantipyrine and potassium ferricyanide. Arylesterase, a thiol enzyme, is reactivated by 2-mercaptoethano...
journal_title:Clinical chemistry
pub_type: 杂志文章
doi:
更新日期:1979-10-01 00:00:00
abstract::We compared a selection of quantitative immunological methods for prostatic acid phosphatase (PAP) with routine colorimetric assays for total and tartrate-labile acid phosphatase and evaluated their relative clinical merits in the differential diagnosis of prostatic carcinoma. We also assessed a wide range of commerci...
journal_title:Clinical chemistry
pub_type: 杂志文章
doi:
更新日期:1986-09-01 00:00:00
abstract::Over the past decade, significant improvements in immunochemical and electrophoretic techniques have enabled collection of heretofore unavailable data on proteins in biological fluids, greatly increasing our understanding of protein physiology in the various body compartments and providing the foundation for clinical ...
journal_title:Clinical chemistry
pub_type: 杂志文章,评审
doi:
更新日期:1982-05-01 00:00:00
abstract::This one-dimensional thin-layer chromatographic method is used for assay of phospholipids in the gastric aspirate of newborns. The solvent mixture (chloroform/hexane/methanol/glacial acetic acid/water, 12/7/4/3/0.3 by vol) completely resolves lecithin, sphingomyelin, phosphatidylinositol, phosphatidylserine, phosphati...
journal_title:Clinical chemistry
pub_type: 杂志文章
doi:
更新日期:1988-04-01 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::To evaluate their potential usefulness in the differential diagnosis of Cushing's syndrome, we estimated the urinary excretion rates of the following non-metabolized, unbound steroid hormones: pregnenolone, progesterone, 17-OH-pregnenolone, 17-OH-progesterone, dehydroepiandrosterone (DHEA), androstenedione, testostero...
journal_title:Clinical chemistry
pub_type: 杂志文章
doi:
更新日期:1986-01-01 00:00:00
abstract::Two patients with Paget's disease of bone were subjected to plasmapheresis. Alkaline phosphatase activities of serum declined sharply, but returned to preplasmapheresis values within eight to 10 days. The biological half-life of circulating skeletal alkaline phosphatase, as calculated from these experiments, is betwee...
journal_title:Clinical chemistry
pub_type: 杂志文章
doi:
更新日期:1982-01-01 00:00:00
abstract::We evaluated the new Greiner G-400 selective multichannel analyzer. Thirty different tests can be run in combination profile and single-test mode at a rate between 150 and 300 tests per hour. The new photometer allows kinetic and equilibrium (endpoint) measurements. The G-400 analyzer demonstrated excellent precision,...
journal_title:Clinical chemistry
pub_type: 杂志文章
doi:
更新日期:1985-02-01 00:00:00
abstract::Single-spin density-gradient ultracentrifugation (DUC) has proven to be a reproducible method for detection of low-density-lipoprotein (LDL) heterogeneity. Recently another method has been described for this: gradient gel electrophoresis (GGE) of serum, a method that might be more suitable for screening. To gain insig...
journal_title:Clinical chemistry
pub_type: 杂志文章
doi:
更新日期:1991-06-01 00:00:00
abstract::Unsaturated cobalamin-binding capacity in plasma (P-UBBC) is determined by use of a silica gel (QUSO G32) to separate haptocorrin (P-ApoHC) and transcobalamin (P-ApoTC). The method is sensitive and precise: detection limit 13 pmol/L, interassay coefficients of variation 3% for P-UBBC (mean = 1080 pmol/L), 4% for P-Apo...
journal_title:Clinical chemistry
pub_type: 杂志文章
doi:
更新日期:1989-07-01 00:00:00
abstract:BACKGROUND:Intraventricular hemorrhage (IVH) is a major cause of neurologic disabilities in preterm newborns. We evaluated the use of plasma activin A concentrations to predict the development of perinatal IVH. METHODS:We measured nucleated erythrocyte (NRBC) counts, plasma activin A, hypoxanthine (Hyp), and xanthine ...
journal_title:Clinical chemistry
pub_type: 杂志文章
doi:10.1373/clinchem.2005.065979
更新日期:2006-08-01 00:00:00