摘要:

An automated column-switching high-performance liquid chromatographic (HPLC) method with ultraviolet detection is described for a simple and rapid determination of melphalan, an alkylating agent, in human plasma following direct sample injection. The system consists of a pretreatment column and an analytical column connected in series via a switching valve. Plasma samples are loaded onto a pretreatment column with an aqueous mobile phase, with which the sample to be analyzed is retained and the solubilized plasma proteins are flushed to be discarded. The retained compound is eluted from the pretreatment column onto the analytical column by using the chromatographic mobile phase with a higher elution capacity. The column-switching technique can be used to achieve an automated assay. Analytical recovery of the compound was 99.1%, and the coefficients of both intra- and interday variations did not exceed 3.5%. The detection limit was 10 ng/ml for the compound. Recovery of melphalan in plasma was only 2.1% after 4 weeks at 25°C, as compared to 24.5% at 5°C and 100.1% at −20°C.

ISSN:0163-4356    

出版商:OVID    

年代:1992

数据来源: OVID

摘要:

A heterogeneous enzyme-labeled immunometric assay for quantifying digoxin in serum or plasma was developed. The sample's drug reacts with an excess of an antidigoxin Fab‘-β-galactosidase monoconjugate and then the free monoconjugate is removed by polyacrylamide digitoxigenin-coupled beads; the β-galactosidase activity of the supernatant measured photometrically at 634 nm is directly proportional to the digoxin concentration in the sample. The assay shares the basic reagents for the immunological reaction with the Seralyzer dry-strip immunometric assay; the reagents for the indicator enzyme reaction were instead formulated in liquid form for use with common clinical analyzers. The test requires a two-point calibration (a 3.0 μg/L digoxin calibrator and a reagent blank). One sample can be assayed in ∼20 min; the assay range is from 0.3 to 5.0 μg/L. Dilution tests showed an average found/expected ratio of 100.6%. Mean analytical recovery was 99.2%. Overall coefficients of variation (CVs) (three replicates for 12 runs over 15 days; daily calibration) ranged from 4.9 to 10.0% (Technicon RA-50) and from 2.5 to 10.0% (Cobas Fara) for samples with digoxin concentrations of 4.7 to 0.5 μg/L. No interference was found by high levels of common analytes (bilirubin, triglycerides, hemoglobin, total protein, uric acid) or anticoagulants. Cross-reactivity by digoxin metabolites and structurally-related compounds was investigated. Good correlations were found with radioimmunoassay (RIA) (r= 0.986) and enzyme immunoassay (EIA) (r= 0.994). Thus, the assay is a specific, reliable, and convenient method for measuring digoxin in both small and large laboratories.

ISSN:0163-4356    

出版商:OVID    

年代:1992

数据来源: OVID

摘要:

We have compared the whole blood concentrations of parent cyclosporin A (CsA) using monoclonal fluorescence polarization immunoassay (FPIA) and radioimmunoassay (RIA) as well as polyclonal FPIA in kidney, heart, and bone marrow transplant patients (n = 89). A good correlation was found between monoclonal FPIA and monoclonal RIA (r= 0.96) and a slightly worse one between polyclonal and monoclonal FPIA (r= 0.90). The interassay coefficient of variation was satisfactory for all the methods—<5% for monoclonal FPIA. The monoclonal FPIA assay with Abbott TDx appears to provide rapid, precise, and accurate measurement of parent CsA. It is therefore useful for therapeutic monitoring of CsA in whole blood in kidney, heart, and bone marrow transplant patients.

ISSN:0163-4356    

出版商:OVID    

年代:1992

数据来源: OVID

摘要:

The purpose of this study was to document the effect of education on the appropriateness of serum drug concentration (SDC) collection. This study included a period of education for hospital personnel involved in the acquisition of drug levels. These included nursing staff, lab personnel, housestaff (residents/interns), ward clerks, and pharmacists. This study included patients receiving aminoglycoside and/or vancomycin while on the general medicine service during the specified study periods. Patients receiving <72 h of antimicrobial therapy and patients transferred to or from the surgery service were excluded from the study. A retrospective pre- and posteducation comparison using Chi-square analysis was made to determine whether the percentage of appropriate and useful SDCs was improved through education. There was a significant difference (p< 0.005) between the percentage of appropriate SDCs in the pre- and posteducation period. As a result of the study, a change in procedure for ordering SDCs was initiated, using an educational program, in order to continue the trend of appropriate SDCs at the Veterans Administration.

ISSN:0163-4356    

出版商:OVID    

年代:1992

数据来源: OVID