Activity of oxantel pamoate monotherapy and combination chemotherapy against Trichuris muris and hookworms : revival of an old drug

BACKGROUND: It is widely recognized that only a handful of drugs are available against soil-transmitted helminthiasis, all of which are characterized by a low efficacy against Trichuris trichiura, when administered as single doses. The re-evaluation of old, forgotten drugs is a promising strategy to identify alternative anthelminthic drug candidates or drug combinations. METHODOLOGY: We studied the activity of the veterinary drug oxantel pamoate against Trichuris muris, Ancylostoma ceylanicum and Necator americanus in vitro and in vivo. In addition, the dose-effect of oxantel pamoate combined with albendazole, mebendazole, levamisole, pyrantel pamoate and ivermectin was studied against T. muris in vitro and additive or synergistic combinations were followed up in vivo. PRINCIPAL FINDINGS: We calculated an ED50 of 4.7 mg/kg for oxantel pamoate against T. muris in mice. Combinations of oxantel pamoate with pyrantel pamoate behaved antagonistically in vitro (combination index (CI) = 2.53). Oxantel pamoate combined with levamisole, albendazole or ivermectin using ratios based on their ED50s revealed antagonistic effects in vivo (CI = 1.27, 1.90 and 1.27, respectively). A highly synergistic effect (CI = 0.15) was observed when oxantel pamoate-mebendazole was administered to T. muris-infected mice. Oxantel pamoate (10 mg/kg) lacked activity against Ancylostoma ceylanicum and Necator americanus in vivo. CONCLUSIONSIGNIFICANCE: Our study confirms the excellent trichuricidal properties of oxantel pamoate. Since the drug lacks activity against hookworms it is necessary to combine oxantel pamoate with a partner drug with anti-hookworm properties. Synergistic effects were observed for oxantel pamoate-mebendazole, hence this combination should be studied in more detail. Since, of the standard drugs, albendazole has the highest efficacy against hookworms, additional investigations on the combination effect of oxantel pamoate-albendazole should be launche

Multiwavelength study of the starburst galaxy NGC7714. I: Ultraviolet-Optical spectroscopy

We have studied the physical conditions in the central 300 pc of the proto-typical starburst galaxy NGC 7714. Our analysis is based on ultraviolet spectroscopy with the HST+GHRS and ground-based optical observations.The data are interpreted using evolutionary models optimized for young starburst regions. The massive stellar population is derived in a self-consistent way using the continuum and stellar absorption lines in the ultraviolet and the nebular emission line optical spectrum. The central starburst has an age of about 4.5 Myr, with little evidence for an age spread. Wolf-Rayet features at the ultraviolet indicates a stellar population of $\sim$ 2000 Wolf-Rayet stars. The overall properties of the newly formed stars are quite similar to those derived, e.g., in 30 Doradus. A standard Salpeter IMF is consistent with all observational constraints. We find evidence for spatial structure within the central 300 pc sampled. Therefore it is unlikely that the nucleus of NGC 7714 hosts a single star cluster exceeding the properties of other known clusters. Contrary to previous suggestions, we find no evidence for a nuclear supernova rate that would significantly exceed the total disk-integrated rate. About one supernova event per century is predicted.Comment: 19 pages, 9 figures in a tar file. Accepted for publication in ApJ, 1999, March, issue 51

Sistema de apoio à decisão para a gestão escolar

Os Sistemas de Informação com recursos às Tecnologias da Informação e da Comunicação contribuem de forma decisiva para o sucesso das organizações. A Escola não é excepção. A Gestão da Informação e do Conhecimento assumem um papel relevante nas organizações para que estas possam responder a um mundo em constante mudança. É, portanto, necessário que as organizações e os seus profissionais desenvolvam novas posturas e novas formas de gerir a inteligência organizacional, investindo na melhoria conjunta e equilibrada dos seus recursos tecnológicos e humanos. Neste contexto, tendo presente o papel relevante que os Sistemas de Apoio à Decisão podem desempenhar no Ensino, surge esta dissertação que se pretende que contribua para enriquecer o Sistema de Informação existente na Escola Secundária das Laranjeiras, numa perspectiva sociotécnica. Desenvolvemos um Sistema de Apoio à Decisão para o Conselho Executivo da Escola que integra: (1) um sistema de classificação automática de alunos com base em parâmetros de comportamento e rendimento, capaz de caracterizar o perfil/rendimento de cada aluno, com uma interface gráfica de fácil utilização e uma base de dados para armazenamento de dados e resultados; (2) um sistema de contactos de funcionários docentes e não docentes com uma base de dados e uma interface gráfica que permite efectuar consultas com facilidade; (3) uma interface gráfica que permite o acesso directo a uma multiplicidade de aplicações utilizadas pelos vários serviços da Escola, ao sistema de classificação de alunos, ao sistema de contactos e ao sítio Web da Escola.N/