ABSTRACT
Cancer constitutes the second main mortality cause in the world, after cardiovascular diseases. In spite of the progresses in the chemotherapeutics treatments, many patients fail chemotherapy, mainly because of side effects or multi-drugs resistance, proving the need and importance of the research for new molecules with anticancer activity, more effective and with smaller adverse effects. Various compounds derived from plant secondary metabolites are commonly used in the chemotherapy against cancer and the natural products play an important role in the research for new molecules. Among several molecules of natural origin evaluated by MTT assay in murine tumor cell lines [breast (LM3) and lung (LP07)] the quinona-methide triterpenes tingenone and pristimerin showed marked cytotoxic activity presenting IC50 around 2 and 5 µM respectively. The structure-activity relationship suggests that rings A and B containing an α, ß-unsaturated carbonyl group are essential for the observed cytotoxic activity. The interaction between these positions and acetylcisteyne residues suggests a probable mechanism of action. The in vitro mutagenic activity was also evaluated by the Salmonella microsome assay (Ames test) for pristimerin and tingenone with and without metabolic activation (S9) in the strains TA98, TA97a, TA100 and TA102, none of which showed mutagenic potential in any strains. Estrogenic and anti-estrogenic activities were also studied by the e-screen assay in MCF-7 cells with negative results. The present data point to the importance of pristimerin and tingenone as representative of an emerging class of potential anticancer chemicals.
ABSTRACT
The objective of this study was to determine the effects of forest fragmentation on ant richness in a landscape of Atlantic Forest in Northeast Brazil. More specifically, the ant richness was related to the attributes of fragments (area and distance from the fragment central point to the edge), landscape (forest cover surrounding the fragments), and tree community (plant density, richness, and percentage of shade tolerant species). The surveys were carried out in 19 fragments located in Alagoas State from October 2007 to March 2008. Samples were collected through a 300 m transect established in the center of each fragment, where 30 1-m² leaf litter samples were collected at 10 m intervals. A total of 146 ant species was collected, which belonged to 42 genera, 24 tribes and nine subfamilies. The attributes of fragments and landscape did not influence ant richness. On the other hand, tree density explained ca. 23 percent of ant richness. In relation to functional groups, both density and richness of trees explained the richness of general myrmicines (the whole model explained ca. 42 percent of the variation in this group) and percentage of shade tolerant trees explained the richness of specialist predator ants (30 percent for the whole model). These results indicate that ant fauna is more influenced by vegetation integrity than by fragment size, distance to edge or forest cover surrounding fragments.
Subject(s)
Animals , Ecosystem , Trees , Ants , Brazil , Population DynamicsABSTRACT
A síndrome Melkersson-Rosenthal é idiopática caracterizada por uma ou mais das seguintes manifestações: edema orofacial recorrente, causando aumento gradual dos tecidos envolvidos, paralisia facial recorrente e língua plicata. O inicío da manifestação ocorre, geralmente, na infância e recidivas são comuns. Os tratamentos sugeridos são empíricos e incluem uso de antibióticos e antiflamatórios corticosteróides e cirurgia para excisão de tecidocicatricial e decompressão nervosa. Este trabalho apresenta características clínicas, meios de diagnóstico e tratamento dessa patologia através da apresentação de um caso clínico acompanhado no Serviço de Cirurgia e Traumatologia Bucomaxilofacial do Complexo Hospitalar da Santa Casa desde 2000. O paciente do relato é do genero masculino, apresentava a tríade de sintomatologia da doença completa e acreditava ser portador de alguma neoplasia. O paciente apresentou melhora ao ser tratado com clofazamina