Composition, richness and nestedness of gallery forest bird assemblages in an Amazonian savanna landscape: lessons for conservation.

Gallery forests are important to the maintenance of a substantial portion of the biodiversity in neotropical savanna regions, but management guidelines specific to this forest type are limited. Here, we use birds as study group to assess if: (1) functional traits can predict the abundance and occupancy of forest species within a savanna landscape, (2) habitat structures influence the taxonomic, functional, and phylogenetic diversity of forest assemblages, and (3) less diverse gallery forest assemblages are a nested subset of more diverse assemblages living near continuous forests. Then, we propose strategies on how gallery forests can be managed to maintain their species assemblages amidst the fast expansion of human activities across tropical savanna landscapes. We studied 26 sites of gallery forests in an Amazonian savanna landscape and found that: (1) habitat specificity is the only functional trait that predicts species abundance and occupancy across a landscape; (2) phylogenetic diversity is negatively correlated with understory foliage density; (3) the percentage of forests and savannas around sites is positively correlated with both phylogenetic and functional diversity; (4) increasing human activities around gallery forest negatively influences taxonomic and functional diversity; and (5) forest bird assemblages are not distributed at random across the landscape but show a nested pattern caused by selective colonization mediated by habitat filtering. Our combined findings have three implications for the design of conservation strategies for gallery forest bird assemblages. First, maintaining the connectivity between gallery forests and adjacent continuous forests is essential because gallery forest bird assemblages are derived from continuous forest species assemblages. Second, because most species use the savanna matrix to move across the landscape, effectively managing the savanna matrices where gallery forests are embedded is as important to maintaining viable populations of forest bird species as managing the gallery forest themselves. Third, in savanna landscapes planned to be used for agriculture production, protecting gallery forests alone is not enough. Instead, gallery forests should be protected with surrounding savanna buffers to avoid the detrimental effects (edge effects and isolation) of human activities on their biodiversity.

Extinction risk of narrowly distributed species of seed plants in Brazil due to habitat loss and climate change.

In a world where changes in land cover and climate happen faster than ever due to the expansion of human activities, narrowly distributed species are predicted to be the first to go extinct. Studies projecting species extinction in tropical regions consider either habitat loss or climate change as drivers of biodiversity loss but rarely evaluate them together. Here, the contribution of these two factors to the extinction risk of narrowly distributed species (with ranges smaller than 10,000 km2) of seed plants endemic to a fifth-order watershed in Brazil (microendemics) is assessed. We estimated the Regional Climate Change Index (RCCI) of these watersheds (areas with microendemics) and projected three scenarios of land use up to the year 2100 based on the average annual rates of habitat loss in these watersheds from 2000 to 2014. These scenarios correspond to immediate conservation action (scenario 1), long-term conservation action (scenario 2), and no conservation action (scenario 3). In each scenario, areas with microendemics were classified into four classes: (1) areas with low risk, (2) areas threatened by habitat loss, (3) areas threatened by climate change, and (4) areas threatened by climate change and habitat loss. We found 2,354 microendemic species of seed plants in 776 areas that altogether cover 17.5% of Brazil. Almost 70% (1,597) of these species are projected to be under high extinction risk by the end of the century due to habitat loss, climate change, or both, assuming that these areas will not lose habitat in the future due to land use. However, if habitat loss in these areas continues at the prevailing annual rates, the number of threatened species is projected to increase to more than 85% (2,054). The importance of climate change and habitat loss as drivers of species extinction varies across phytogeographic domains, and this variation requires the adoption of retrospective and prospective conservation strategies that are context specific. We suggest that tropical countries, such as Brazil, should integrate biodiversity conservation and climate change policies (both mitigation and adaptation) to achieve win-win social and environmental gains while halting species extinction.

Effect of γ-lactones and γ-lactams compounds on Streptococcus mutans biofilms.

Considering oral diseases, antibiofilm compounds can decrease the accumulation of pathogenic species such as Streptococcus mutans at micro-areas of teeth, dental restorations or implant-supported prostheses. OBJECTIVE: To assess the effect of thirteen different novel lactam-based compounds on the inhibition of S. mutans biofilm formation. MATERIAL AND METHODS: We synthesized compounds based on γ-lactones analogues from rubrolides by a mucochloric acid process and converted them into their corresponding γ-hydroxy-γ-lactams by a reaction with isobutylamine and propylamine. Compounds concentrations ranging from 0.17 up to 87.5 µg mL-1 were tested against S. mutans. We diluted the exponential cultures in TSB and incubated them (37°C) in the presence of different γ-lactones or γ-lactams dilutions. Afterwards, we measured the planktonic growth by optical density at 630 nm and therefore assessed the biofilm density by the crystal violet staining method. RESULTS: Twelve compounds were active against biofilm formation, showing no effect on bacterial viability. Only one compound was inactive against both planktonic and biofilm growth. The highest biofilm inhibition (inhibition rate above 60%) was obtained for two compounds while three other compounds revealed an inhibition rate above 40%. CONCLUSIONS: Twelve of the thirteen compounds revealed effective inhibition of S. mutans biofilm formation, with eight of them showing a specific antibiofilm effect.

Effect of γ-lactones and γ-lactams compounds on Streptococcus mutans biofilms

Abstract Considering oral diseases, antibiofilm compounds can decrease the accumulation of pathogenic species such as Streptococcus mutans at micro-areas of teeth, dental restorations or implant-supported prostheses. Objective To assess the effect of thirteen different novel lactam-based compounds on the inhibition of S. mutans biofilm formation. Material and methods We synthesized compounds based on γ-lactones analogues from rubrolides by a mucochloric acid process and converted them into their corresponding γ-hydroxy-γ-lactams by a reaction with isobutylamine and propylamine. Compounds concentrations ranging from 0.17 up to 87.5 μg mL-1 were tested against S. mutans. We diluted the exponential cultures in TSB and incubated them (37°C) in the presence of different γ-lactones or γ-lactams dilutions. Afterwards, we measured the planktonic growth by optical density at 630 nm and therefore assessed the biofilm density by the crystal violet staining method. Results Twelve compounds were active against biofilm formation, showing no effect on bacterial viability. Only one compound was inactive against both planktonic and biofilm growth. The highest biofilm inhibition (inhibition rate above 60%) was obtained for two compounds while three other compounds revealed an inhibition rate above 40%. Conclusions Twelve of the thirteen compounds revealed effective inhibition of S. mutans biofilm formation, with eight of them showing a specific antibiofilm effect.

Perfil dos pacientes portadores de câncer colorretal operados em um hospital geral: necessitamos de um programa de rastreamento acessível e efetivo / Profile of patients with colorectal cancer operated in a general hospital: we need an accessible and effective screening program

O objetivo do presente trabalho é demonstrar o panorama atual do câncer colorretal em um hospital geral no estado do Rio de Janeiro, enfocando aspectos relacionados à apresentação clínica e ao diagnóstico tardio. Trata-se de um estudo retrospectivo que incluiu os pacientes em acompanhamento no ambulatório de seguimento de câncer colorretal da II Clínica Cirúrgica do Hospital Federal de Bonsucesso nos últimos 5 anos (2004-2009). Os sintomas mais comuns foram dor abdominal (60,1 por cento), obstrução intestinal (41,1 por cento), emagrecimento (36,7 por cento), sangramento (33.5 por cento), anemia (14,5 por cento), perfuração (6,3 por cento) e fístula (1,2 por cento). Em relação aos pacientes com tumores de cólon direito, os sintomas mais prevalentes foram emagrecimento (54,5 por cento), dor (45,4 por cento), obstrução (45,4 por cento) e anemia (27,2 por cento). Nos pacientes com tumores de cólon esquerdo e sigmóide foram dor (60,5 por cento), obstrução (42,9 por cento), emagrecimento (38,5 por cento), sangramento (32,4 por cento) e anemia (16,6 por cento). Enquanto nos pacientes com tumores de reto foram sangramento (70 por cento), obstrução (60 por cento), dor (60 por cento), emagrecimento (20 por cento) e perfuração (10 por cento). No momento da cirurgia, 53 pacientes apresentavam metástases à distância (33,5 por cento), sendo o fígado o órgão mais acometido, em 36 pacientes (67,9 por cento), seguido pelo peritônio com 11 casos (20,7 por cento) e pelos anexos (ovários) com 4 casos (7,5 por cento). Oitenta e oito pacientes (55,6 por cento) apresentavam metástase linfonodal.Quanto ao estadiamento, observamos que os pacientes operados na emergência apresentavam a seguinte distribuição: 0 por cento Estádio I, 28,2 por cento Estádio II, 30,4 por cento Estádio III e 41,3 por cento Estádio IV. Os pacientes operados eletivamente foram estratificados como Estádio I 2,7 por cento, Estádio II 27,7 por cento, Estádio III 25 por cento e Estádio IV 44 por cento. Conclusã...

The aim of this study is to demonstrate the current panorama of colorectal cancer in a general hospital in Rio de Janeiro, focusing on aspects related to the clinical presentation and delayed diagnosis. This is a retrospective study that included patients followed at the outpatient section of colorectal cancer follow-up of the Segunda Clínica Cirúrgica do Hospital Federal Bonsucesso in the past five years (2004-2009). The most common symptoms were abdominal pain (60.1 percent), intestinal obstruction (41.1 percent), weight loss (36.7 percent), bleeding (33.5 percent), anemia (14.5 percent), perforation (6.3 percent) and fistula (1.2 percent). Patients with right colon tumors presented with weight loss (54.5 percent), pain (45.4 percent), obstruction (45.4 percent) and anemia (27.2 percent). In patients with tumors of the left colon and sigmoid, the most common symptoms were pain (60.5 percent), obstruction (42.9 percent), weight loss (38.5 percent), bleeding (32.4 percent) and anemia (16.6 percent). Patients with rectal tumors presented with bleeding (70 percent), obstruction (60 percent), pain (60 percent), weight loss (20 percent) and perforation (10 percent). At surgery, 53 patients had distant metastases (33.5 percent), the liver being the organ most affected in 36 patients (67.9 percent), followed by the peritoneum in 11 cases (20.7 percent) and ovaries with 4 cases (7.5 percent). Eighty-eight patients (55.6 percent) had nodal metastasis. Regarding TNM staging, we found that the emergency group distribution was as follows: Stage I 0 percent, 28.2 percent Stage II, Stage III 30.4 percent and 41 3 percent Stage IV, whereas the elective group staging distribution was: 2.7 percent Stage I, Stage II 27.7 percent, 25 percent Stage III and Stage IV 44 percent. Conclusion: The profile of patients operated in our institution (which reflects the national reality) is composed mainly with patients with advanced cancer stages. Based on the data presented, it is nece...