Abstract:
:To determine when a change in serial measurements of prothrombin time in patients receiving oral anticoagulant therapy (ACT) is a statistically significant biological change necessitating dose adjustment, one must know the size of the "critical difference" in statistical terms (i.e., probabilities). In a cohort of 32 ACT patients at pharmacological steady-state, we studied the within-subject total variation of prothrombin time, expressed as International Normalized Ratio (INR), over 6 months. The total within-subject variation (CV) of INR was 10.1%. The corresponding critical differences required for significance of change in serial INR results was 0.7 at a therapeutic target of 2.5 INR and 1.0 at a therapeutic target of 3.5 INR. The data presented allow generation of objective criteria for monitoring ACT patients and deciding dose adjustments. We recommend that estimations of critical differences for significant change of INR in ACT patients should be based on results obtained in the specific clinic investigated to mirror the routine total variation of INR measurements they obtain.
journal_name
Clin Chemjournal_title
Clinical chemistryauthors
Lassen JF,Brandslund I,Antonsen Ssubject
Has Abstractpub_date
1995-03-01 00:00:00pages
444-7issue
3eissn
0009-9147issn
1530-8561journal_volume
41pub_type
杂志文章abstract:BACKGROUND:Although cardiac troponin (cTn) is a cornerstone marker in the assessment and management of patients with acute coronary syndrome (ACS) and heart failure (HF), cTn is not diagnostically specific for any single myocardial disease process. This narrative review discusses increases in cTn that result from acute...
journal_title:Clinical chemistry
pub_type: 杂志文章,评审
doi:10.1373/clinchem.2009.130799
更新日期:2009-12-01 00:00:00
abstract:BACKGROUND:We have developed a silicon-based biosensor that generates a visual signal in response to nucleic acid targets. METHODS:In this system, capture oligonucleotide probes are immobilized on the surface of the biosensor. Interaction of the capture probes with a complementary target and a biotinylated detector ol...
journal_title:Clinical chemistry
pub_type: 杂志文章
doi:
更新日期:1999-09-01 00:00:00
abstract::With the ultramicroanalytical system described here we can measure glucose in 1 microL of plasma or serum. The sample is placed on a dry, multilayer film element (Eastman Kodak), where a colored spot about 3.5 mm in diameter develops. The reflectance of these spots is measured with a reflectance digital matrix photome...
journal_title:Clinical chemistry
pub_type: 杂志文章
doi:
更新日期:1983-12-01 00:00:00
abstract::We describe a procedure based on equilibrium dialysis that allows the simultaneous determination of free testosterone and testosterone bound to non-sex-hormone-binding globulin (non-SHBG) in plasma. After saturating SHBG with 5 alpha-dihydrotestosterone (DHT) according to a technique recently described, the percentage...
journal_title:Clinical chemistry
pub_type: 杂志文章
doi:
更新日期:1993-06-01 00:00:00
abstract::We describe a competitive enzyme immunoassay, the ExtrAvidin-biotin system, for determining osteocalcin in human serum or plasma. Antibodies were raised against bovine osteocalcin. Binding of the antibodies to osteocalcin was calcium-dependent. Limit of detection is 0.07 nmol/L (0.4 microgram/L). The standard curve fo...
journal_title:Clinical chemistry
pub_type: 杂志文章
doi:
更新日期:1992-10-01 00:00:00
abstract:BACKGROUND:Improved methods are required to screen drug candidates for their influences on protein interactions. There is also a compelling need for miniaturization of screening assays, with attendant reductions in reagent consumption and assay costs. METHODS:We used sensitive, miniaturized proximity ligation assays (...
journal_title:Clinical chemistry
pub_type: 杂志文章
doi:10.1373/clinchem.2007.099424
更新日期:2008-07-01 00:00:00
abstract::Several factors can limit the use of therapeutic drug monitoring (TDM) for cancer chemotherapeutic agents, including poorly defined concentration-effect relationships for many antineoplastic agents. This is further complicated by cancer being a highly heterogeneous group of diseases, each of which may have a unique co...
journal_title:Clinical chemistry
pub_type: 杂志文章
doi:
更新日期:1998-02-01 00:00:00
abstract::We have compared the operational, medical, and fiscal consequences of performing urgent glucose testing at the bedside vs in the central laboratory. The turnaround time (TAT) with bedside testing was only 1-2 min shorter than that from the central laboratory, to which specimens are sent by pneumatic tube and from whic...
journal_title:Clinical chemistry
pub_type: 杂志文章
doi:
更新日期:1994-08-01 00:00:00
abstract::Synovial fluid samples were collected from 45 patients with rheumatoid arthritis, spondylarthropathy, or osteoarthritis, to study their content of elastase (EC 3.4.21.37) and of cysteine proteinases (EC 3.4.22.1, 3.4.22.15). We measured both elastase complexed with alpha 1-proteinase inhibitor and elastase activity to...
journal_title:Clinical chemistry
pub_type: 杂志文章
doi:
更新日期:1992-09-01 00:00:00
abstract:BACKGROUND:It has been shown that a high percentage of interleukin-8 (IL-8) in blood is cell associated. Recently, a simple method for determination of cell-associated IL-8 in whole blood after cell lysis has been described. The purpose of this study was to evaluate this method, to examine the influence of preanalytic ...
journal_title:Clinical chemistry
pub_type: 杂志文章
doi:
更新日期:2000-09-01 00:00:00
abstract:BACKGROUND:We explored the utility of multiplexed temperature gradient capillary electrophoresis (TGCE) as a screening tool for identifying genetic changes in the human mitochondrial genome. We examined changes in mitochondrial DNA (mtDNA) in nonmelanoma skin cancers (NMSCs), using TGCE to resolve genetic differences c...
journal_title:Clinical chemistry
pub_type: 杂志文章
doi:10.1373/clinchem.2004.040311
更新日期:2005-02-01 00:00:00
abstract:BACKGROUND:New genetic forms of hereditary hemochromatosis (HH) or hereditary hyperferritinemia (HF) have been identified over the last few years, and abnormalities of various genes may interact in a single patient. This study aimed to develop a rapid automated method for sequencing the main genes involved. METHODS:We...
journal_title:Clinical chemistry
pub_type: 杂志文章
doi:10.1373/clinchem.2007.090605
更新日期:2007-12-01 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
abstract::I describe a micro-scale method for determining lead in whole blood by utilizing a graphite furnace. Sample pretreatment consists of fivefold dilution with a dilute surfactant. The method is directly calibrated with lead standards prepared in dilute HNO3. To eliminate a small, nonspecific absorption signal from the...
journal_title:Clinical chemistry
pub_type: 杂志文章
doi:
更新日期:1975-04-01 00:00:00
abstract::We investigated the efficiency, accuracy, and reliability of the ultrafiltration/dipstick methodology commonly used to diagnose myoglobinuria. Twenty-five myoglobin-containing urine specimens were filtered by centrifugation for 15 min at 1500g through a Centricon-30 membrane filter. Both the original specimen and filt...
journal_title:Clinical chemistry
pub_type: 杂志文章
doi:
更新日期:1996-06-01 00:00:00
abstract::We describe a sensitive, simple, and rapid two-site immunoenzymometric assay for thyrotropin in dried blood samples on filter paper, for use in screening for neonatal primary hypothyroidism. In this method, two dried-blood spots of 3 mm diameter (equivalent to about 5.4 microliter of blood) are incubated overnight wit...
journal_title:Clinical chemistry
pub_type: 杂志文章
doi:
更新日期:1981-08-01 00:00:00
abstract:BACKGROUND:Mass spectrometric assays could potentially replace protein immunoassays in many applications. Previous studies have demonstrated the utility of liquid chromatography-multiple-reaction monitoring-mass spectrometry (LC-MRM/MS) for the quantification of proteins in biological samples, and many examples of the ...
journal_title:Clinical chemistry
pub_type: 杂志文章
doi:10.1373/clinchem.2011.173856
更新日期:2012-04-01 00:00:00
abstract::Ethchlorvynol is a commonly abused sedative hypnotic. I report here a seven-day study of serum ethchlorvynol concentrations in a patient who had received an extreme overdose. These concentrations were correlated with the patient's response to stimuli. Serum ethchlorvynol concentrations were logarithmically related to ...
journal_title:Clinical chemistry
pub_type: 杂志文章
doi:
更新日期:1975-06-01 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::The isoenzyme pattern of N-acetyl-beta-glucosaminidase (NAG) in serum and urine was studied in two groups of patients with diabetes mellitus and in 30 control subjects. Total NAG activity was significantly (P less than 0.001) increased in the serum and urine of the 20 diabetics with vascular complications, but was ins...
journal_title:Clinical chemistry
pub_type: 杂志文章
doi:
更新日期:1988-12-01 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::A digestion procedure involving nitric acid is described for determination of aluminum in blood, serum, and plasma by graphite-furnace atomic absorption spectroscopy. Contamination was not a severe problem if all operations were performed in a dust-free atmosphere. Conditions for such determination of aluminum in bloo...
journal_title:Clinical chemistry
pub_type: 杂志文章
doi:
更新日期:1982-11-01 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:In clinical and forensic toxicology, general unknown screening is used to detect and identify exogenous compounds. In this study, we aimed to develop a comprehensive general unknown screening method based on liquid chromatography coupled with a hybrid triple-quadrupole linear ion trap mass spectrometer. MET...
journal_title:Clinical chemistry
pub_type: 杂志文章
doi:10.1373/clinchem.2006.067116
更新日期:2006-09-01 00:00:00
abstract:BACKGROUND:B-type natriuretic peptide (BNP), which is activated in heart failure (HF), is processed to an active form by corin. The corin gene is expressed in the human heart and kidney, but corin protein expression in the heart, kidney, and circulation, along with whether proBNP is processed by circulating corin, rema...
journal_title:Clinical chemistry
pub_type: 杂志文章
doi:10.1373/clinchem.2010.153908
更新日期:2011-01-01 00:00:00
abstract::Circulating prostate cells can be detected in cancer patients by using reverse transcriptase-PCR (RT-PCR) assay for prostate-specific antigen (PSA) and prostate-specific membrane antigen (PSM) mRNA. A quality-control study involving a conventional RT-PCR assay was performed and, surprisingly, detected both transcripts...
journal_title:Clinical chemistry
pub_type: 杂志文章
doi:
更新日期:1998-03-01 00:00:00
abstract:BACKGROUND:Risk assessments of patients should be based on objective variables, such as biological markers that can be measured routinely. The acute response to stress causes the release of catecholamines from the adrenal medulla accompanied by chromogranin A (CGA). To date, no study has evaluated the prognostic value ...
journal_title:Clinical chemistry
pub_type: 杂志文章
doi:10.1373/clinchem.2007.102442
更新日期:2008-09-01 00:00:00
abstract::We describe a discrete automated radioimmunoassay system for determining choriomammotropin (placental lactogen) in human serum. With the present system it can be measured in as many as 37 unknown sera (50 muL) and three quality-control sera, in duplicate, within 1.5 h. The time required for sample preparation, incubat...
journal_title:Clinical chemistry
pub_type: 杂志文章
doi:
更新日期:1979-01-01 00:00:00
abstract:BACKGROUND:Small RNAs are key players in the regulation of gene expression and differentiation. However, many different classes of small RNAs (sRNAs) have been described with distinct biogenesis pathways and, as a result, with different biochemical properties. To analyze sRNAs by deep sequencing, complementary DNA synt...
journal_title:Clinical chemistry
pub_type: 杂志文章
doi:10.1373/clinchem.2019.305045
更新日期:2019-12-01 00:00:00
abstract:BACKGROUND:Kallikrein-related peptidase 6 (KLK6), a member of the serine protease family of kallikrein (KLK) genes, is dysregulated in ovarian carcinomas (OCa) and its overexpression is associated with poor prognosis. Regulation of its expression is poorly understood and is likely to be influenced by multiple mechanism...
journal_title:Clinical chemistry
pub_type: 杂志文章
doi:10.1373/clinchem.2012.193060
更新日期:2013-01-01 00:00:00