Acute ecotoxicity of coated colloidal goethite nanoparticles on Daphnia magna: Evaluating the influence of exposure approaches.

Synthesized iron oxide nanoparticles have been proposed as an alternative to non-dispersed iron oxides for in situ environmental remediation. Their colloidal properties enable their injection into porous media, i.e. soils and aquifers, and offer a higher efficiency in removing contaminants. However, this dispersed state is also the cause of concerns over their environmental fate and toxicity, e.g., by increasing the exposure time to aquatic organisms in groundwater remediation activities. Therefore, the objective of in situ groundwater remediation is to establish local reactive barriers in the subsurface by injection by means of reactive colloids with a controllable mobility under in situ conditions and present as colloids as shortly as possible. In this work, we examined the toxicity of humic acid-coated colloidal goethite nanoparticles in Daphnia magna. The adaptation of the ecotoxicological standard tests for nanomaterials is intensely discussed to increase comparability and reliability of results. In the present study, the effect of different exposure conditions on goethite nanoparticles colloidal behaviour and acute Daphnia immobilization effects was investigated. For this purpose, iron concentration in the water column, aggregation state and acute effects were studied in: i) a standard test, ii) test design with exposure dispersions incubated for a week and iii) water accommodated fraction. Despite the different aggregation and settling of the particles found between the approaches tested, no differences in toxicity were observed. Coated nanoparticles were found clogging up the filtering apparatus, and/or adhered to the exoskeleton, hindering the swimming and molting, and causing the immobilization and death of the organisms at doses of ≥943mg/L (EC50). The data suggests that the toxic potential of these nanoparticles is mainly related to the physical interaction with the daphnids.

[Systematic review of the effectiveness and indications of antidigoxin antibodies in the treatment of digitalis intoxication]. / Revisión sistemática sobre la efectividad e indicaciones de los anticuerpos antidigoxina en la intoxicación digitálica.

INTRODUCTION AND OBJECTIVES: Cardiac glucoside intoxication is a frequent medical problem given the following: the very narrow therapeutic range, its use in advanced aged patients, in patients with altered renal function, and because of interaction with other drugs. There are two types of digitalis intoxication: one that appears as a complication of the treatment with digitalis, and the other as a result of an accidental ingestion or in suicide attempt. The objective of this study was to review and assess the level of scientific evidence on the effectiveness and the indications of use of Fab fragments of antidigoxine antibodies. METHODS: A systematic bibliographic search in the following databases was made: MEDLINE, The Cochrane Library, The Iowa Drug Information Service, Embase, LMS/R&D Insight, and Indice Médico Español. The selected papers were classified according to their level of scientific evidence. RESULTS: Abstracts of 252 references were reviewed. In the reviewed bibliography no controlled, randomized trials were found. Most of the studies found are descriptions of case series or single cases that were treated with antidigoxin Fab fragments. These types of studies provide little or no scientific evidence to speak of. None of the treatment regimes with antidigoxin antibody Fab fragments so far proposed have proven to be valid in a controlled, randomized clinical trial. CONCLUSIONS: There is a very high level of concordance among the studies reviewed with regards to the efficacy and the indications for the use of Fab fragments in severe acute accidental digitalis intoxication and in suicide attempts. Regarding those intoxications that result in patients undergoing digitalis therapy, usual therapeutic approach is traditional treatment and the monitorization of the severity of the intoxication.

[Minimal criteria of epidemiologic studies of dental health of school children]. / Criterios mínimos de los estudios epidemiológicos de salud dental en escolares.

Epidemiological studies of oral health in schools constitute a basic instrument for planning prevention and dental health programs. This paper sets forth some minimum common elements in the design, execution, and analysis of such studies, and presents a method for the adjustment of examining teams, index ages, diagnostic criteria, classification of dental malocclusions, and indicators for analysis of results.