The verification of hazardous ingredients disclosures in selected material safety data sheets.

Under the provisions of the Workplace Hazardous Materials Information System, workers in Canada must be provided with accurate and comprehensive Material Safety Data Sheets (MSDSs) describing controlled products used in the workplace. As part of an ongoing auditing project, the MSDSs of some controlled products in use under federal jurisdiction were assessed for accuracy and completeness of their ingredient disclosures. Chemical analyses of samples using gas chromatography-mass spectrometry, infrared spectrophotometry, X-ray fluorescence, and wet methods, were performed to verify the ingredient disclosures in accompanying MSDSs. In this article, analytical processes and results are presented for three cases in which MSDS ingredient disclosures were incomplete. The products included a synthetic lubricant used in a mining operation, a detergent concentrate used for aircraft cleaning, and an epoxy reducer used in aircraft maintenance. In each case, undisclosed hazardous ingredients were detected at concentrations which required their disclosure. In at least one of these cases, the information provided in other sections of the MSDS failed to adequately describe the hazards and required protective measures for the composition discovered. Because the results suggest circumstances in which the inaccurate MSDS could act as a mechanism for workplace injury, compliance measures including employer, inspector, and user education, improved MSDS writer qualifications, and the incorporation of chemical analysis in active auditing programs are recommended.

Ureaplasma/Mycoplasma-infected amniotic fluid: pregnancy outcome in treated and nontreated patients.

OBJECTIVE: To determine if treatment of a positive amniotic fluid culture for mycoplasmal colonization obtained at genetic amniocentesis is associated with improved pregnancy outcome. STUDY DESIGN: A retrospective analysis of 2718 genetic amniocentesis specimens cultured for Ureaplasma/Mycoplasma was undertaken. Specimens were obtained between March 1993 and January 1997. The Irvine culture kit was used to culture all specimens. Data collected included indication for amniocentesis, gestational age at amniocentesis, karyotype, gestational age at delivery, pregnancy outcome, and any antimicrobial treatment. RESULTS: During this time period 44 patients were found to be culture-positive for Ureaplasma/Mycoplasma. Thirty-five were treated with oral erythromycin. Mid-trimester loss was 11.4% and 44.4% (p = 0.04) in the treated and untreated groups, respectively. Preterm delivery was similar in the two groups, 19.4% and 20% (p = NS). CONCLUSION: Treatment of an amniotic mycoplasmal colonization with erythromycin was associated with fewer mid-trimester losses after genetic amniocentesis. Preterm delivery rates between the two groups were similar, which may indicate recolonization.

Prediction of acute graft rejection in renal transplantation: the utility of cyclosporine blood concentrations.

While cyclosporine is recommended to be used only in conjunction with monitoring of its blood concentrations, the utility of these measurements in preventing treatment failure is not established. In a group of 52 patients trough levels and steady-state concentrations were monitored in serum and whole blood by specific (SP) and nonspecific (NS) assays (polyclonal radioimmunoassay, PR; fluorescence polarization immunoassay, FP; high-pressure liquid chromatography, HP). From as many as 10 determinations of trough level and steady state concentrations during the first 40 days after renal transplantation, the lowest measurement was selected. In the case of an acute rejection episode within that time period, only values until that event were considered. Trough level measurements in serum by PR/NS and by FP/NS and in whole blood by HP/SP were not significantly different between patients with and patients without rejection episodes. However, simultaneously measured steady-state values (serum/PR/NS and serum/FP/NS) were significantly lower in patients suffering from rejection (with rejection SS/serum/PR/NS mean = 127 ng/ml, SD = 41 ng/ml; without rejection mean = 163 ng/ml, SD = 60 ng/ml; P = 0.027, t test). This difference could not be demonstrated for steady state/whole blood/HP/SP measurements. A logistic regression analysis demonstrated that the probability of rejection can be decreased by up to 40% if steady state/serum/PR/NS or steady state/serum/FP/NS values never drop below 250 ng/ml early after renal transplantation.

Cyclosporine monitoring in renal transplantation: area under the curve monitoring is superior to trough-level monitoring.

Trough levels (TL) of cyclosporine (CS) measured in serum by the polyclonal radioimmunoassay (SR) are useful for dissecting the etiology of clinical events, but they are a poor guide to dosage adjustments. In renal transplant patients immunosuppressed by low doses of prednisone and CS given orally, once-a-day TL (24-h) monitoring was replaced by area under the curve (AUC) monitoring, i.e., measuring the area under the concentration (SR)-time curve from seven blood samples (0, 2, 4, 6, 10, 14, and 24 h) at clinical steady state, which was reached on the 3rd day after a change in the oral dose rate. The therapeutic target was an average concentration at steady state (Css av) of 200 ng/ml during the first 6 months after transplantation and 150 ng/ml thereafter. The Css av was calculated by dividing the AUC by the dosing interval (24 h). Two findings demonstrated the superiority of AUC monitoring over TL monitoring. First, in 71 paired observations AUC but not TL was significantly correlated with the dose expressed as total mg (r = 0.381, p = 0.001) or mg/kg body weight (r = 0.538, p = 0.0001). Second, after adjusting (n = 26) the oral dose rate (to achieve the therapeutic target) the absolute error (i.e., deviation from the target) in the AUC observation (15%) was significantly (p = 0.0005) smaller than in the TL observation (36%). Monitoring AUC at clinical steady state reduced the number of dosage adjustments by a factor of 3.