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 factors that might be important in modulating the free fraction of this drug. Human serum albumin (HSA), high concentrations of the primary glucuronide metabolite of MPA, and sodium salicylate significantly affected MPA binding. For HSA the mean +/- SE binding capacity (Bmax) and the dissociation constant (Kd) were 1095 +/- 34 mumol/L and 12.98 +/- 0.93 mumol/L, respectively. The dose for 50% inhibition (IC50) of inosine monophosphate dehydrogenase isoform II by MPA increased 5.4-fold as the concentration of HSA added to the enzyme reaction mixture increased from 0 to 50 g/L (0-724 mumol/L). Furthermore, the IC50 MPA concentration for phytohemagglutinin A-stimulated human peripheral blood mononuclear cells increased 4.8-fold when incubations were performed in the presence of 10 g/L (145 mumol/L) HSA vs no added HSA. These data support the hypothesis that the pharmacological activity of MPA is a function of unbound drug concentration.
journal_name
Clin Chemjournal_title
Clinical chemistryauthors
Nowak I,Shaw LMsubject
Has Abstractpub_date
1995-07-01 00:00:00pages
1011-7issue
7eissn
0009-9147issn
1530-8561journal_volume
41pub_type
杂志文章abstract::Diabetic patients in poor glycemic control show increased glycation of total plasma proteins, but little is yet known about the relative extents to which the various individual proteins are glycated. Thus, we studied the non-enzymic glycation of several major plasma proteins and plasma protein fractions in normal and ...
journal_title:Clinical chemistry
pub_type: 杂志文章
doi:
更新日期:1987-12-01 00:00:00
abstract::We describe a rapid, sensitive, and specific "high performance" liquid chromatographic analysis for disopyramide and its mono-N-dealkylated metabolite in serum, urine, and saliva. We used a mu-Bondapak CN column and an acetate buffer mobile phase containing methanol. Retention times for the two compounds and the inter...
journal_title:Clinical chemistry
pub_type: 杂志文章
doi:
更新日期:1979-03-01 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:BACKGROUND:A substantial proportion of the variability in the absorption and clearance of cyclosporin A (CsA) after oral administration has been attributed to variability in liver cytochrome P-450 3A4 (CYP3A4) activity and intestinal P-glycoprotein (P-gp) concentration. A polymorphism in the CYP3A4 promoter region, ter...
journal_title:Clinical chemistry
pub_type: 杂志文章
doi:
更新日期:2001-06-01 00:00:00
abstract::Nitric oxide is a soluble gas continuously synthesized by the endothelium. This substance has a wide range of biological properties that maintain vascular homeostasis, including modulation of vascular dilator tone, regulation of local cell growth, and protection of the vessel from injurious consequences of platelets a...
journal_title:Clinical chemistry
pub_type: 杂志文章,评审
doi:
更新日期:1998-08-01 00:00:00
abstract::We determined estrogen receptor protein and carcinoembryonic antigen in cytosols prepared from 189 human breast carcinoma tissues, 85 benign or normal breast biopsies, and 101 tissue specimens metastatic from breast carcinoma. Carcinoembryonic antigen was observed in 70% of the primary carcinomatous tissues, 15% of th...
journal_title:Clinical chemistry
pub_type: 杂志文章
doi:
更新日期:1976-08-01 00:00:00
abstract::The clinical value of measuring concentrations of methylmalonic acid in serum (S-MMA) as an aid in the diagnosis of cobalamin deficiency has recently aroused interest. In 58 healthy subjects, ages 40-68 years, we found a 0.95 reference interval of 0.05-0.37 mumol/L (mean 0.21, SD 0.094). In 33 of the subjects, who wer...
journal_title:Clinical chemistry
pub_type: 杂志文章
doi:
更新日期:1990-07-01 00:00:00
abstract::In the disposable rotor of the SAM microcentrifugal analyzer, various lyophilized reagents are predistributed in 24 33-microL cuvets, for determination of multiple analytes in one specimen (e.g., for patient profiles). We evaluated a prototype of this system, which can be used at 25, 30, or 37 degrees C; absorbance re...
journal_title:Clinical chemistry
pub_type: 杂志文章
doi:
更新日期:1985-09-01 00:00:00
abstract::In iron deficiency, zinc protoporphyrin (ZPP) is produced instead of heme, and the ZPP concentration in erythrocytes is increased (normal < or = 40 mumol/mol heme). We investigated the relevance of ZPP for staging iron deficiency. ZPP was determined by hematofluorometry in samples from 103 patients. Nineteen patients ...
journal_title:Clinical chemistry
pub_type: 杂志文章
doi:
更新日期:1994-05-01 00:00:00
abstract::This method for determining aluminum in human serum involves electrothermal atomic absorption spectrophotometry. A longer drying time allows less pre-dilution of the sample, and the method also includes a flush cycle after atomization. Standard-addition methodology is used to eliminate matrix effects and the need for ...
journal_title:Clinical chemistry
pub_type: 杂志文章
doi:
更新日期:1983-06-01 00:00:00
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journal_title:Clinical chemistry
pub_type: 杂志文章
doi:
更新日期:1978-02-01 00:00:00
abstract::The deleterious, disruptive effects of estrogen mimics on the endocrine system were discovered after the compounds were released into the environment. Their chemical structure does not obviously resemble that of steroid hormones; hence, their estrogenic effects were totally unexpected. In addition to occupational expo...
journal_title:Clinical chemistry
pub_type: 杂志文章
doi:
更新日期:1995-12-01 00:00:00
abstract::We evaluated a dual-precipitation method for determining cholesterol in high-density lipoprotein (HDL) and its subfractions HDL2 and HDL3. After total HDL was isolated by precipitation of very-low-density (VLDL) and low-density (LDL) lipoproteins with polyethylene glycol (Mr 8000), HDL2 was isolated from total HDL by ...
journal_title:Clinical chemistry
pub_type: 杂志文章
doi:
更新日期:1988-11-01 00:00:00
abstract::We describe an automated assay of glycohemoglobin performed with the Abbott Vision analyzer. The assay is based on batch affinity-extraction with 3-aminophenylboronic acid-derivatized agarose beads. Reagents are packaged in a disposable test pack. Whole-blood specimens are hemolyzed with saponin within a glass capilla...
journal_title:Clinical chemistry
pub_type: 杂志文章
doi:
更新日期:1992-12-01 00:00:00
abstract:BACKGROUND:Plasma creatinine concentration and calculated creatinine clearance are of limited value as glomerular filtration rate (GFR) markers in patients with decompensated liver cirrhosis. We assessed plasma cystatin C as an indicator of GFR in such patients. METHODS:We studied 36 patients with decompensated liver ...
journal_title:Clinical chemistry
pub_type: 杂志文章
doi:
更新日期:2002-06-01 00:00:00
abstract:BACKGROUND:Formation of deposits of the insoluble amyloid beta-peptide is believed to be causally related with neurodegeneration in Alzheimer disease (AD). The beta-peptide originates from a larger amyloid precursor protein (APP) by the action of proteolytic enzymes. The first proteolytic event leading to amyloid forma...
journal_title:Clinical chemistry
pub_type: 杂志文章
doi:10.1373/clinchem.2006.066720
更新日期:2006-06-01 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::Transcutaneous pCO2 electrode response time was optimized by use of a new electrode filling solution composed of NaCl/NaHCO3 electrolyte buffer (100 and 20 mmol/L, respectively) in an equivolume mixture of glycerol and water. The 95% response time to a step change in pCO2 was 49.9 +/- 2.8 s (mean +/- SD) when there wa...
journal_title:Clinical chemistry
pub_type: 杂志文章
doi:
更新日期:1982-07-01 00:00:00
abstract::Numerous outcome measures can be used to characterize and compare the performance of alternative quality-control (QC) strategies. The performance measure traditionally used in the QC planning process is the probability of rejecting an analytical run when a critical out-of-control error condition exists. Another perfor...
journal_title:Clinical chemistry
pub_type: 杂志文章
doi:
更新日期:1997-04-01 00:00:00
abstract::We report the production and comparative specificities of antisera raised to different immunogens containing codeine, morphine, and oxycodone. Antisera raised to bovine serum albumin (BSA) conjugates of codeine-6-hemisuccinate, ethylmorphine-6-hemisuccinate, or oxycodone-6-carboxymethyloxime had greatest recognition o...
journal_title:Clinical chemistry
pub_type: 杂志文章
doi:
更新日期:1981-09-01 00:00:00
abstract:BACKGROUND:The Elecsys beta-CrossLaps serum assay measures type I collagen degradation fragments (beta-CTx) that contain the beta-isomerized octapeptide EKAHD-beta-GGR. We investigated the analytical performance of the assay and changes in beta-CrossLaps in patients with metabolic bone diseases. METHODS:The electroche...
journal_title:Clinical chemistry
pub_type: 临床试验,杂志文章
doi:
更新日期:2001-08-01 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::An optimized assay for alkaline phosphatase (EC 3.1.3.1) is reported. A discrete analyzer, the DuPont Automatic Clinical Analyzer (aca), was used for this study. The assay is based on results of response-surface experimental co-optimization techniques, and response is enhanced over the present aca assay. A key feature...
journal_title:Clinical chemistry
pub_type: 杂志文章
doi:
更新日期:1981-07-01 00:00:00
abstract::Histograms of the results of quantitative clinical laboratory analyses are usually broadly skewed because some of the patients have normal values with respect to the analyte being measured while values for others are below or above normal. We describe a technique for calculating the maximum possible number of individu...
journal_title:Clinical chemistry
pub_type: 杂志文章
doi:
更新日期:1978-04-01 00:00:00
abstract::We describe modifications to two cartridges, those for alkaline phosphatase and creatinine, on an 18-channel SMAC (Sequential Multichannel Analyzer Computerized), which allow all 18 tests to be run with a commonly prediluted sample. This decreases the required sample size and eliminates the problem of fibrin clots in ...
journal_title:Clinical chemistry
pub_type: 杂志文章
doi:
更新日期:1980-05-01 00:00:00
abstract::In this immunoenzymatic assay for human lutropin (hLH) we used bi-specific antibodies (BiAbs) obtained from the fusion of two hybridomas producing antibodies to beta-D-galactosidase and hLh. The BiAb complexed with the enzyme beta-D-galactosidase was used as tracer in a double-determinant assay. We compared the assay ...
journal_title:Clinical chemistry
pub_type: 杂志文章
doi:
更新日期:1990-01-01 00:00:00
abstract::Using image-analyzing equipment, we measured the effect of quinidine on the activity of naphthol AS-D chloroacetate esterase, alpha-naphthyl butyrate esterase, alpha-naphthyl acetate esterase, and acid phosphatase in individual cells of a human Hep G2 hepatoma cell line. The impact of the drug on the morphology of the...
journal_title:Clinical chemistry
pub_type: 杂志文章
doi:
更新日期:1988-03-01 00:00:00
abstract::We evaluated a new EMIT II monoclonal amphetamine/methamphetamine assay for screening human urine by comparing it with the EMIT d.a.u. monoclonal amphetamine/methamphetamine assay and a fluorescence polarization assay. The EMIT II assay has a cutoff of 1 mg/L d-methamphetamine. The EMIT II and EMIT d.a.u. assays were ...
journal_title:Clinical chemistry
pub_type: 杂志文章
doi:
更新日期:1993-01-01 00:00:00
abstract::Using a high-affinity solid-phase-bound antibody (Ka = 1.2 X 10(11) L/mol), we have standardized a two-step radioimmunoassay for free triiodothyronine (FT3) in serum, based on immunoextraction. The method was validated by comparison with an equilibrium-dialysis procedure (r = 0.96) involving RIA of T3 in the dialysate...
journal_title:Clinical chemistry
pub_type: 杂志文章
doi:
更新日期:1987-03-01 00:00:00
abstract::A fixed-time incubation method for measuring acetylsalicylic acid esterase was improved by using a higher concentration of the substrate, acetylsalicylic acid, and an activator, Ca2+. The enzymatic activity in serum was 25-fold that measured by earlier methods. Inhibition studies showed a pattern similar to that repor...
journal_title:Clinical chemistry
pub_type: 杂志文章
doi:
更新日期:1983-03-01 00:00:00