RESUMEN
As a result of the stringent data requirements of the Registration, Evaluation, Authorisation, and Restriction of Chemicals (REACH) regulation, a vast amount of ecotoxicological data has become available through the dissemination portal of the European Chemicals Agency (ECHA). As of April 2014, the database contained 12,439 unique substances from 47,909 dossiers. This vast database could be used to refine existing, or to create new, non-testing methods, such as quantitative structure-activity relationships (QSARs). Acute fish toxicity data were mined from the ECHA database using the eChemPortal; after filtering for single organic substances, 1159 experimental data points remained, representing 564 compounds. To evaluate the quality and accessibility of this data, the authors used the data to refine and improve an existing QSAR. The reliability of the data submitted to the ECHA database, as well as the effectiveness of the Klimisch scoring system, were assessed by comparing the refined QSAR with established QSAR benchmarks. The model developed meets all Organisation for Economic Co-operation and Development principles, has strong internal (leave-one-out internally cross-validated correlation coefficient [Q(2)(LOO)] = 0.91) and external (external coefficient of determination (predicted vs experimental [test set])) validation statistics, and can provide reliable fish median lethal concentration (LC50) predictions for non-polar narcotics. Although some issues with dossier misinformation were discovered, it was found that the ECHA dissemination portal is a valuable and reliable data source. When queried using the eChemPortal, chemical dossiers containing reliable data could be found quickly. The ECHA dissemination portal holds great potential for future QSAR development and improvement, such as updating QSARs within the Ecological Structure-Activity Relationships (ECOSAR) program.
Asunto(s)
Cyprinidae/fisiología , Bases de Datos como Asunto , Modelos Biológicos , Oncorhynchus mykiss/fisiología , Pruebas de Toxicidad Aguda , Animales , Ecotoxicología , Europa (Continente) , Concentración 50 Inhibidora , Relación Estructura-Actividad Cuantitativa , Reproducibilidad de los ResultadosRESUMEN
A "gold standard" method for the diagnosis of bacterial vaginosis (BV) is lacking. The clinical criteria described by the Amsel technique are subjective and difficult to quantify. Alternatively, the reading of Gram-stained vaginal smears by scoring techniques such as those that use the Nugent or Hay-Ison scoring systems is again subjective, requires expert personnel to perform the reading, and is infrequently used clinically. Recently, a new diagnostic device, the Osmetech Microbial Analyzer--Bacterial Vaginosis (OMA-BV), which determines a patient's BV status on the basis of measurement of the amount of acetic acid present in a vaginal swab specimen, was approved by the Food and Drug Administration. The present study uses the conducting polymer gas-sensing technology of OMA-BV to measure the concentration of acetic acid in the headspace above vaginal swab specimens from patients undergoing treatment for BV with metronidazole. In 97.8% of the cases the level of acetic acid detected fell sharply during the treatment period, crossing from above to below the diagnostic threshold of 900 ppm. The diagnosis obtained on the basis of the level of vaginal acetic acid was compared with the diagnoses obtained by use of the Amsel criteria and the Nugent scoring system both at the time of initial entry into the study and at the repeat samplings on days 7 and 14. The results obtained with OMA-BV showed overall agreements compared with the results of the Amsel and Nugent tests of 98 and 94%, respectively, for the 34 patients monitored through the treatment process. This provides further evidence that the measurement of vaginal acetic acid by headspace analysis with conducting polymer sensors is a valid alternative to present tests for the diagnosis of BV.