24 research outputs found
Morphological and morphometric studies of the antennal sensilla from two populations of Atta robusta (Borgmeier 1939) (Hymenoptera: Formicidae)
Leishmanicidal Metabolites from Cochliobolus sp., an Endophytic Fungus Isolated from Piptadenia adiantoides (Fabaceae)
Protozoan parasites belonging to genera Leishmania and Trypanosoma are the etiological agents of severe neglected tropical diseases (NTDs) that cause enormous social and economic impact in many countries of tropical and sub-tropical areas of the world. In our screening program for new drug leads from natural sources, we found that the crude extract of the endophytic fungus Cochliobolus sp. (UFMGCB-555) could kill 90% of the amastigote-like forms of Leishmania amazonensis and inhibit by 100% Ellman's reagent reduction in the trypanothione reductase (TryR) assay, when tested at 20 ”g mLâ1. UFMGCB-555 was isolated from the plant Piptadenia adiantoides J.F. Macbr (Fabaceae) and identified based on the sequence of the internally transcribed spacer (ITS) regions of its ribosomal DNA. The chromatographic fractionation of the extract was guided by the TryR assay and resulted in the isolation of cochlioquinone A and isocochlioquinone A. Both compounds were active in the assay with L. amazonensis, disclosing EC50 values (effective concentrations required to kill 50% of the parasite) of 1.7 ”M (95% confidence intervalâ=â1.6 to 1.9 ”M) and 4.1 ”M (95% confidence intervalâ=â3.6 to 4.7 ”M), respectively. These compounds were not active against three human cancer cell lines (MCF-7, TK-10, and UACC-62), indicating some degree of selectivity towards the parasites. These results suggest that cochlioquinones are attractive lead compounds that deserve further investigation aiming at developing new drugs to treat leishmaniasis. The findings also reinforce the role of endophytic fungi as an important source of compounds with potential to enter the pipeline for drug development against NTDs
HOOKWORM AND THREADWORM INFECTIONS AND THEIR ASSOCIATION WITH HEMOGLOBIN AND EOSINOPHIL CONCENTRATIONS IN RESIDENTS OF SALVADOR-BAHIA, BRAZIL
Organização do trabalho de enfermagem na Atenção BĂĄsica: uma questĂŁo para a saĂșde do trabalhador
As segmentaçÔes da oferta de serviços de saĂșde no Brasil: arranjos institucionais, credores, pagadores e provedores
Reconhecer Flexner: inquérito sobre produção de mitos na educação médica no Brasil contemporùneo
Visceral leishmaniasis in Rio de Janeiro, Brazil: eco-epidemiological aspects and control
In vitro and in vivo activity of meglumine antimoniate produced at Farmanguinhos-Fiocruz, Brazil, against Leishmania (Leishmania) amazonensis, L (L.) chagasi and L (Viannia) braziliensis
The leishmanicidal activity of four batches of meglumine antimoniate, produced in Farmanguinhos-Fiocruz, Brazil (TAMs), was assessed and compared to GlucantimeŸ-Aventis Pharma Ltda. Using the amastigote-like in vitro model, the active concentrations of Sb v varied from 10”g/ml to 300 ”g/ml for L. (L.) chagasi and from 50”g/ml to 300”g/ml for L. (L.) amazonensis, with no statistically significant differences among the four batches of TAMs and GlucantimeŸ. The inhibitory concentrations (IC50) determined by the amastigote-infected macrophage model for TAM01/03 and GlucantimeŸ were, respectively: 26.3”g/ml and 127.6”g/ml for L. chagasi, 15.4”g /ml and 22.9”g/ml for L. amazonensis, and 12.1”g/ml and 24.2”g/ml for L. (V.) braziliensis. The activities of the four batches of TAMs were confirmed in an in vivo model by assessing, during eight weeks skin lesions caused by L. braziliensis in hamster that were treated with 20mg Sb v/Kg/day for 30 consecutive days. The meglumine antimoniate produced by Farmanguinhos was as effective as the reference drug, GlucantimeŸ-Aventis, against three species of Leishmania that are of medical importance in Brazil