Toxicity and Alkaloid Profiling of the Skin of the Golfo Dulcean Poison Frog Phyllobates vittatus (Dendrobatidae).

Frogs in the genus Phyllobates are known for the presence of batrachotoxin, a highly toxic alkaloid, in their skin. Nevertheless, Phyllobates frogs from Costa Rica and Panama (P. lugubris and P. vittatus) are considered non-toxic, as they have been reported to harbor low concentrations of this alkaloid. However, the potential toxicity of Central American Phyllobates has not been assessed experimentally. Our goal was to determine the toxicity of the whole skin of P. vittatus, an endemic species from the Southeastern Pacific region of Costa Rica. We performed median lethal dose (LD50) tests in mice to determine general toxicity, and an irritant assay based on the behavioral responses of mice to subcutaneous injection, to determine differences in irritability, as a measure of toxicity, among three study localities. Using UPLC-ESI-QTOF, we obtained chemical profiles of the methanolic extract of frog skins. Due to the absence of mortality at the studied doses, we were unable to estimate LD50. However, we recorded a list of toxicity symptoms in mice that are consistent with cardiotoxic effects, and found that mice presented more symptoms at higher concentrations of skin extracts during the first hour of the LD50 assays, recovering completely at all doses by the end of the assay. On the other hand, we did not detect differences in irritability among studied localities. Additionally, we putatively identified three toxic alkaloids (Batrachotoxinin A, DHQ 251A and Lehm 275A). This study provides the first experimental data on the toxicity and associated symptoms in mice, as well as the chemical profile of the skin of P. vittatus. We suggest that the skin alkaloids of P. vitattus may confer a chemical defense towards predators.

Changes in nesting sites abundance and their use by woodpeckers along an urban gradient: a ten-year comparison

Woodpeckers nesting substrate abundance may be reduced by urban expansion, negatively affecting their reproduction. Long-term studies in the tropics are rare but valuable to estimate how urban development has affected ecological communities. We present a ten-year comparison on nesting substrate abundance and their use by Melanerpes rubricapillus and M. chrysauchen woodpeckers along an urban gradient in Golfito, Costa Rica; which include three habitats and three substrates (snags, palms, and posts). Conditions remained unchanged in non-urban areas. In semi-urban areas, snag, posts, and nests on them, have decreased. In urban areas, despite snags and posts remaining constant, their use also decreased. In semi-urban and urban areas, palms and palm nests increased. This long term comparison indicates that woodpeckers took advantage of the increased presence of ornamental palms in gardens.

La abundancia de sustratos para anidación de pájaras carpinteros puede reducirse debido a la expansión urbana, afectando negativamente su reproducción. Los estudios a largo plazo en los trópicos son escazos, pero valiosos para estimar cómo el desarrollo urbano ha afectado las comunidades ecológicas. Presentamos una comparación de diez años sobre la abundancia y uso de sustratos de anidación de los carpinteros Melanerpes rubricapillus y M. chrysauchen en un gradiente urbano en Golfito, Costa Rica; que incluye tres hábitats y tres sustratos (tocones, palmas y postes). Las condiciones permanecieron similares en áreas no urbanas. En las áreas semi urbanas, los postes y tocones, así como los nidos en ellos disminuyeron. En áreas urbanas, a pesar de que los postes permanecieron constantes, su uso disminuyó. En las áreas semi urbanas y urbanas, la cantidad de palmas y de nidos en estas aumentó. Esta comparación a largo plazo indica que los carpinteros tomaron ventaja del aumento en la presencia de palmas ornamentales en los jardines.

[Indoor air pollution caused by cigarette smoke in public places in Portugal]. / Poluição do ar interior provocada pelo fumo do cigarro em locais públicos de Portugal.

OBJECTIVE: There have been few studies investigating the level of cigarette smoke pollution to which people in several public and private places are exposed. The purpose of this study was to quantify the level of air pollution produced by cigarette smoking in workplaces and leisure settings. METHODS: The study was carried out in Braga, Portugal, in 2005. Nicotine content in indoor air was measured using passive monitors containing a 37-mm diameter filter inside treated with sodium bisulphate. The monitors were installed in predefined public workplaces and leisure settings. Median nicotine content was estimated for each place studied. RESULTS: Nicotine was detected in 85% of the samples. Extremely high air contamination levels were found in discos with a median of 82.26 microg/m3, ranging between 5.79 and 106.31 microg/m3. Workplaces of public administration and university buildings showed the lowest nicotine content. CONCLUSIONS: The study findings confirm the need to promote the implementation of smoke-free policies in workplaces and leisure settings to protect workers' health and as a reinforcing measure of an environment which facilitates smokers to quit smoking.

Poluição do ar interior provocada pelo fumo do cigarro em locais públicos de Portugal / Indoor air pollution caused by cigarette smoke in public places in Portugal

OBJETIVO: Poucos têm sido os estudos para conhecer o grau de poluição pelo fumo do tabaco a que estão sujeitas as pessoas em vários lugares públicos e privados. O objectivo do estudo foi quantificar o nível de poluição do ar provocada pelo fumo do cigarro em locais de trabalho e de lazer. MÉTODOS: O estudo foi realizado no concelho de Braga, Portugal, em 2005. A medição dos teores de nicotina no ar interior foi realizada com monitores passivos contendo um filtro de 37 mm de diâmetro tratado com bissulfato sódico no seu interior. Os monitores foram colocados em lugares públicos, de trabalho e de lazer, pré-definidos. Para cada um dos locais, calculou-se a mediana da nicotina. RESULTADOS: A presença de nicotina foi detectada em 85 por cento das amostras. Foram encontrados valores elevados de contaminação do ar nas discotecas, com mediana de 82,26 mug/m³, variando entre os 5,79 e os 106,31 mug/m³.Os locais de trabalho da administração pública e da universidade apresentaram os valores mais baixos de nicotina. CONCLUSÕES: Os dados confirmam a necessidade de reforçar a implemen-tação e sobretudo, o cumprimento de políticas sem fumo nos locais de trabalho e de lazer, em benefício da saúde dos trabalhadores e como medida reforçadora de um ambiente que facilite aos fumadores o abandono do fumo do tabaco.

OBJECTIVE: There have been few studies investigating the level of cigarette smoke pollution to which people in several public and private places are exposed. The purpose of this study was to quantify the level of air pollution produced by cigarette smoking in workplaces and leisure settings. METHODS: The study was carried out in Braga, Portugal, in 2005. Nicotine content in indoor air was measured using passive monitors containing a 37-mm diameter filter inside treated with sodium bisulphate. The monitors were installed in predefined public workplaces and leisure settings. Median nicotine content was estimated for each place studied. RESULTS: Nicotine was detected in 85 percent of the samples. Extremely high air contamination levels were found in discos with a median of 82.26 mug/m³, ranging between 5.79 and 106.31 mug/m³. Workplaces of public administration and university buildings showed the lowest nicotine content. CONCLUSIONS: The study findings confirm the need to promote the implementation of smoke-free policies in workplaces and leisure settings to protect workers' health and as a reinforcing measure of an environment which facilitates smokers to quit smoking.