Effect of fluralaner on the biology, survival, and reproductive fitness of the neotropical malaria vector Anopheles aquasalis.

BACKGROUND: Reducing mosquito abundance or interfering with its ability to support the parasite cycle can help to interrupt malaria in areas of significant risk of malaria transmission. Fluralaner is a safe and effective drug for veterinary use indicated for the treatment against fleas and ticks which acts as an antagonist of chloride ion channels mediated by γ-aminobutyric acid (GABA), preventing the entry of these ions into the postsynaptic neuron, leading to hyperexcitability of the postsynaptic neuron of the central nervous system of arthropods. Fluralaner demonstrated insecticidal activity against different insect species. METHODS: The study aimed to evaluate the effects of fluralaner on the biology, survival, and reproductive fitness of Anopheles aquasalis. The following lethal concentrations (LC) were determined for An. aquasalis: LC5 = 0.511 µM; LC25 = 1.625 µM; LC50 = 3.237 µM. RESULTS: A significant decrease (P < 0.001) was evident in the number of eggs, larvae, and pupae in the group exposed to a sublethal dose of fluralaner when compared to a control group (without the drug). Using blood from dogs after administration of fluralaner, it was observed that the drug causes 100% mortality in An. aquasalis in less than 24 h after feeding; this effect remains even after 90 days in all samples. DISCUSSION: Fluralaner showed the same result for up to 60 days, and after that, there was a slight reduction in its effect, evidenced by a decrease in the percentage of dead females; however, still significant when compared to the control group. CONCLUSION: Fluralaner affects the biology and reduction of survival in An. aquasalis in a lasting and prolonged period, and its fecundity with lower dosages, is a strong candidate for controlling disease vectors.

Unravelling the genome of the brackish water malaria vector Anopheles aquasalis.

Malaria is a severe public health problem in several developing tropical and subtropical countries. Anopheles aquasalis is the primary coastal malaria vector in Central and South America and the Caribbean Islands, and it has the peculiar feature of living in water with large changes in salinity. Recent research has recognised An. aquasalis as an important model for studying the interactions of murine and human Plasmodium parasites. This study presents the complete genome of An. aquasalis and offers insights into its evolution and physiology. The genome is similar in size and gene content to other Neotropical anophelines, with 162 Mb and 12,446 protein-coding genes. There are 1387 single-copy orthologs at the Diptera level (eg. An. gambiae, An. darlingi and Drosophila melanogaster). An. aquasalis diverged from An. darlingi, the primary malaria vector in inland South America, nearly 20 million years ago. Proteins related to ion transport and metabolism belong to the most abundant gene families with 660 genes. We identified gene families relevant to osmosis control (e.g., aquaporins, vacuolar-ATPases, Na+/K+-ATPases, and carbonic anhydrases). Evolutionary analysis suggests that all osmotic regulation genes are under strong purifying selection. We also observed low copy number variation in insecticide resistance and immunity-related genes for all known classical pathways. The data provided by this study offers candidate genes for further studies of parasite-vector interactions and for studies on how anophelines of brackish water deal with the high fluctuation in water salinity. We also established data and insights supporting An. aquasalis as an emerging Neotropical malaria vector model for genetic and molecular studies.

Evolution and assembly of Anopheles aquasalis's immune genes: primary malaria vector of coastal Central and South America and the Caribbean Islands.

Anophelines are vectors of malaria, the deadliest disease worldwide transmitted by mosquitoes. The availability of genomic data from various Anopheles species allowed evolutionary comparisons of the immune response genes in search of alternative vector control of the malarial parasites. Now, with the Anopheles aquasalis genome, it was possible to obtain more information about the evolution of the immune response genes. Anopheles aquasalis has 278 immune genes in 24 families or groups. Comparatively, the American anophelines possess fewer genes than Anopheles gambiae s. s., the most dangerous African vector. The most remarkable differences were found in the pathogen recognition and modulation families like FREPs, CLIP and C-type lectins. Even so, genes related to the modulation of the expression of effectors in response to pathogens and gene families that control the production of reactive oxygen species were more conserved. Overall, the results show a variable pattern of evolution in the immune response genes in the anopheline species. Environmental factors, such as exposure to different pathogens and differences in the microbiota composition, could shape the expression of this group of genes. The results presented here will contribute to a better knowledge of the Neotropical vector and open opportunities for malaria control in the endemic-affected areas of the New World.

Perceptions, feelings, and the routine of older adults during the isolation period caused by the COVID-19 pandemic: a qualitative study in four countries.

OBJECTIVE: To evaluate the knowledge, routine, and perception of older adults from four countries about dealing with COVID-19 in the social isolation period. METHODS: Qualitative study with semistructured interviews. Older persons (≥60 years old), who lived in the urban centers of four different countries (Brazil, United States, Italy, and Portugal), were asked about the changes experienced during the pandemic, new habits or restrictions during isolation, sources of social and emotional support, and their knowledge about COVID-19 pandemic. Data was transcribed, codified, and submitted to content analysis. RESULTS: Twenty-five older persons (10 from Brazil, 5 from Italy, 5 from Portugal, and 5 from the United States) were interviewed. Participants reported feeling restricted in their daily life activities and emotional instability. Described adaptations in habits, coping strategies, and greater understanding of the diseased based on information available in the media. There was homogeneity in the statements of the elderly, showing that the pandemic affected them in a similar way, even though they lived in different cultures and contexts. CONCLUSION: The social isolation caused by the COVID-19 pandemic changed the structure for the performance of many occupations, having an impact in the perception social participation and wellbeing of elders. This data can aid health professionals to outline strategies to deal with the impact of the social isolation in older persons.

Dengue and Zika virus infection patterns vary among Aedes aegypti field populations from Belo Horizonte, a Brazilian endemic city.

Dengue virus (DENV) and Zika virus (ZIKV) belong to the same viral family, the Flaviviridae. They cause recurring threats to the public health systems of tropical countries such as Brazil. The primary Brazilian vector of both viruses is the mosquito Aedes aegypti. After the mosquito ingests a blood meal from an infected person, the viruses infect and replicate in the midgut, disseminate to secondary tissues and reach the salivary gland (SG), where they are ready to be transmitted to a vertebrate host. It is thought that the intrinsic discrepancies among mosquitoes could affect their ability to deal with viral infections. This study confirms that the DENV and ZIKV infection patterns of nine Ae. aegypti field populations found in geographically separate health districts of an endemic Brazilian city vary. We analyzed the infection rate, disseminated infection, vector competence, and viral load through quantitative PCR. Mosquitoes were challenged using the membrane-feeding assay technique and were tested seven and fourteen days post-infection (early and late infection phases, respectively). The infection responses varied among the Ae. aegypti populations for both flaviviruses in the two infection phases. There was no similarity between DENV and ZIKV vector competencies or viral loads. According to the results of our study, the risk of viral transmission overtime after infection either increases or remains unaltered in ZIKV infected vectors. However, the risk may increase, decrease, or remain unaltered in DENV-infected vectors depending on the mosquito population. For both flaviviruses, the viral load persisted in the body even until the late infection phase. In contrast to DENV, the ZIKV accumulated in the SG over time in all the mosquito populations. These findings are novel and may help direct the development of control strategies to fight dengue and Zika outbreaks in endemic regions, and provide a warning about the importance of understanding mosquito responses to arboviral infections.

Phenotypic traits of individuals in a long-term colony of Anopheles (Nyssorhynchus) aquasalis (Diptera: Culicidae) show variable susceptibility to Plasmodium and suggest cryptic speciation.

Anopheles aquasalis is an important malaria vector in coastal regions of South America and islands of the Caribbean. In its original description, the species was divided into two varieties, based on the scaling patterns of their hind-tarsomere 2. Specimens from our 25-year established colony, used for Plasmodium experimental infections, still exhibit both scaling tarsomere patterns. This study examined the DNA sequence of the nuclear Internal Transcribed Spacer 2 (ITS2) and susceptibility to Plasmodium, looking for differences among the phenotypes 30BS and 50BS. One hundred mosquitoes, 25 males and 25 females of each sex, and phenotype were analyzed. Twenty-seven novel haplotypes were identified. Three were found in both phenotypes (30BS and 50BS) regardless of gender. Among the other 27 genotypes, we observed a male-oriented bias in both phenotypic categories. Evaluation of Plasmodium yoelii N67 infections, based on oocyst counts, showed a higher susceptibility of 30BS compared with 50BS. Future studies need to be conducted to evaluate if these genotype assortments among the phenotypic groups reflect differences in fitness, mating, and their susceptibility to infection by Plasmodium parasites.

Cardiovascular risk, lifestyle and anthropometric status of rural workers in Pardo River Valley, Rio Grande do Sul, Brazil.

BACKGROUND: The state of health of rural workers is influenced by the living conditions to which they are subjected, including social, economic, technological and organizational aspects. Given the scarcity of studies on this population of workers, establishing their profile is necessary. OBJECTIVES: To analyze cardiovascular risk according to demographic factors and anthropometric status of rural workers under the Pardo River Valley Regional Development Council (COREDE-VRP). METHODS: Cross-sectional analytical study with rural workers in five municipalities in the COREDE-VRP southern region. We administered a structured questionnaire for lifestyle socioeconomic information, physical activity and self-reported health. Anthropometric measurements, resting heart rate and electrocardiogram (ECG) were performed to analyze heart rate variability (HRV). RESULTS: Women exhibited higher cardiovascular risk, which in turn did not differ as a function of age, marital status, socioeconomic status or lifestyle. We found a relationship between cardiovascular risk and anthropometric measurements, but not with cardiovascular variables. CONCLUSION: Women exhibited higher cardiovascular risk, which was not associated with marital status, socioeconomic status, alcohol use, smoking, sleep disorders or physical activity. Therefore, we emphasize the relationship between cardiovascular risk and anthropometric variables, as well as the lack of association with heart rate and autonomic imbalance.

INTRODUÇÃO: A saúde dos trabalhadores rurais sofre influência decorrente das condições de vida a que estão submetidos, como fatores sociais, econômicos, tecnológicos e organizacionais. Nesse contexto, surge a necessidade de identificar o perfil de saúde de trabalhadores rurais, pela escassez de pesquisas relacionadas a essa área. OBJETIVO: Avaliar o risco cardiovascular de acordo com fatores demográficos e composição corporal em trabalhadores rurais do Conselho Regional de Desenvolvimento do Vale do Rio Pardo (COREDE/VRP). MÉTODO: Estudo transversal analítico realizado com trabalhadores rurais de cinco municípios da microrregião sul do COREDE/VRP. Utilizou-se um questionário de estilo de vida estruturado com informações socioeconômicas sobre atividade física e saúde autorreferida. Foram feitas avaliação antropométrica, verificação da frequência cardíaca de repouso e gravação do eletrocardiograma (ECG), para análise da variabilidade da frequência cardíaca (VFC). RESULTADOS: As mulheres apresentaram significativamente mais risco cardiovascular. Não foram encontradas diferenças para idade, estado civil, classe socioeconômica e estilo de vida. Ao se comparar variáveis antropométricas e cardiovasculares, observou-se que existe relação significativa do risco com a antropometria, não havendo relação entre o risco e as variáveis cardiovasculares. CONCLUSÕES: Observou-se que as mulheres da área rural apresentam significativamente maior risco cardiovascular, não sendo observada relação com o estilo de vida. Além disso, é possível destacar a relação estatisticamente significativa entre as variáveis antropométricas e o risco cardiovascular, não havendo relação entre o risco cardiovascular e a frequência cardíaca e entre o risco cardiovascular e o desequilíbrio autonômico.

Risco cardiovascular, estilo de vida e composição corporal de trabalhadores rurais do Vale do Rio Pardo, RS / Cardiovascular risk, lifestyle and anthropometric status of rural workers in Pardo River Valley, Rio Grande do Sul, Brazil

Introdução: A saúde dos trabalhadores rurais sofre influência decorrente das condições de vida a que estão submetidos, como fatores sociais, econômicos, tecnológicos e organizacionais. Nesse contexto, surge a necessidade de identificar o perfil de saúde de trabalhadores rurais, pela escassez de pesquisas relacionadas a essa área. Objetivo: Avaliar o risco cardiovascular de acordo com fatores demográficos e composição corporal em trabalhadores rurais do Conselho Regional de Desenvolvimento do Vale do Rio Pardo (COREDE/VRP). Método: Estudo transversal analítico realizado com trabalhadores rurais de cinco municípios da microrregião sul do COREDE/VRP. Utilizou-se um questionário de estilo de vida estruturado com informações socioeconômicas sobre atividade física e saúde autorreferida. Foram feitas avaliação antropométrica, verificação da frequência cardíaca de repouso e gravação do eletrocardiograma (ECG), para análise da variabilidade da frequência cardíaca (VFC). Resultados: As mulheres apresentaram significativamente mais risco cardiovascular. Não foram encontradas diferenças para idade, estado civil, classe socioeconômica e estilo de vida. Ao se comparar variáveis antropométricas e cardiovasculares, observou-se que existe relação significativa do risco com a antropometria, não havendo relação entre o risco e as variáveis cardiovasculares. Conclusões: Observou-se que as mulheres da área rural apresentam significativamente maior risco cardiovascular, não sendo observada relação com o estilo de vida. Além disso, é possível destacar a relação estatisticamente significativa entre as variáveis antropométricas e o risco cardiovascular, não havendo relação entre o risco cardiovascular e a frequência cardíaca e entre o risco cardiovascular e o desequilíbrio autonômico.

Background: The state of health of rural workers is influenced by the living conditions to which they are subjected, including social, economic, technological and organizational aspects. Given the scarcity of studies on this population of workers, establishing their profile is necessary. Objectives: To analyze cardiovascular risk according to demographic factors and anthropometric status of rural workers under the Pardo River Valley Regional Development Council (COREDE-VRP). Methods: Cross-sectional analytical study with rural workers in five municipalities in the COREDE-VRP southern region. We administered a structured questionnaire for lifestyle socioeconomic information, physical activity and self-reported health. Anthropometric measurements, resting heart rate and electrocardiogram (ECG) were performed to analyze heart rate variability (HRV). Results: Women exhibited higher cardiovascular risk, which in turn did not differ as a function of age, marital status, socioeconomic status or lifestyle. We found a relationship between cardiovascular risk and anthropometric measurements, but not with cardiovascular variables. Conclusion: Women exhibited higher cardiovascular risk, which was not associated with marital status, socioeconomic status, alcohol use, smoking, sleep disorders or physical activity. Therefore, we emphasize the relationship between cardiovascular risk and anthropometric variables, as well as the lack of association with heart rate and autonomic imbalance.

Socio-economic and demographic characteristics associated with risk behaviour patterns for chronic non-communicable diseases in Brazil: data from the National Health Survey, 2013.

OBJECTIVE: To identify risk behaviour patterns for chronic non-communicable diseases (NCD) in the Brazilian population and to investigate associated socio-economic and demographic factors. DESIGN: Factor analysis was used to identify patterns considering the following risk behaviours: consumption of soft drinks/artificial juice, sweet foods, red meat with apparent fat, chicken skin; inadequate consumption of fruits and vegetables; alcohol abuse; smoking; absence of physical activity during leisure time; and time spent watching television. The χ 2 test was used to compare ratios. All analyses accounted for weighting factors and the study's complex sampling design effect. The socio-economic and demographic variables evaluated were gender, age, schooling level and macro region of residence. SETTING: National Health Survey, a household survey with national representation, conducted in 2013 in Brazil.ParticipantsIndividuals (n 60202) aged 18 years or over. RESULTS: Four risk behaviour patterns were identified: 'Physical inactivity in leisure time and Inadequate consumption of fruits and vegetables', 'Saturated fat', 'Alcohol and Smoking' and 'Sedentary behaviour and Sugar', explaining 52·01 % of the total variance. Overall, greater adherence to 'Saturated fat' and 'Alcohol and Smoking' patterns was observed among men and those with lower education level. The 'Sedentary behaviour and Sugar' and 'Physical inactivity in leisure time and Inadequate consumption of fruits and vegetables' patterns had greater adherence among younger individuals, and the first was associated with higher education whereas the second with less education among individuals residing in the North and Northeast regions. CONCLUSIONS: Risk behaviour patterns for NCD were heterogeneous, reflecting the socio-economic and demographic differences in Brazil.

GD3 ganglioside-enriched extracellular vesicles stimulate melanocyte migration.

Melanomas often accumulate gangliosides, sialic acid-containing glycosphingolipids found in the outer leaflet of plasma membranes, as disialoganglioside GD3 and its derivatives. Here, we have transfected the GD3 synthase gene (ST8Sia I) in a normal melanocyte cell line in order to evaluate changes in the biological behavior of non-transformed cells. GD3-synthase expressing cells converted GM3 into GD3 and accumulated both GD3 and its acetylated form, 9-O-acetyl-GD3. Melanocytes were rendered more migratory on laminin-1 surfaces. Cell migration studies using the different transfectants, either treated or not with the glucosylceramide synthase inhibitor d-1-threo-1-phenyl-2-palmitoylamino-3-pyrrolidino-1-propanol (PPPP), allowed us to show that while GM3 is a negative regulator of melanocyte migration, GD3 increases it. We showed that gangliosides were shed to the matrix by migrating cells and that GD3 synthase transfected cells shed extracellular vesicles (EVs) enriched in GD3. EVs enriched in GD3 stimulated cell migration of GD3 negative cells, as observed in time lapse microscopy studies. Otherwise, EVs shed by GM3+veGD3-ve cells impaired migration and diminished cell velocity in cells overexpressing GD3. The balance of antimigratory GM3 and promigratory GD3 gangliosides in melanocytes could be altered not only by the overexpression of enzymes such as ST8Sia I, but also by the horizontal transfer of ganglioside enriched extracellular vesicles. This study highlights that extracellular vesicles transfer biological information also through their membrane components, which include a variety of glycosphingolipids remodeled in disease states such as cancer.

Overexpression of eukaryotic initiation factor 5A (eIF5A) affects susceptibility to benznidazole in Trypanosoma cruzi populations.

Eukaryotic initiation factor 5A (eIF5A) is a conserved protein with an essential role in translation elongation. Using one and two-dimensional western blotting, we showed that the eIF5A protein level was 2-fold lower in benznidazole (BZ)-resistant (BZR and 17LER) Trypanosoma cruzi populations than in their respective susceptible counterparts (BZS and 17WTS). To confirm the role of eIF5A in BZ resistance, we transfected BZS and 17WTS with the wild-type eIF5A or mutant eIF5A-S2A (in which serine 2 was replaced by alanine). Upon overexpressing eIF5A, both susceptible lines became approximately 3- and 5-fold more sensitive to BZ. In contrast, the eIF5A-S2A mutant did not alter its susceptibility to BZ. These data suggest that BZ resistance might arise from either decreasing the translation of proteins that require eIF5A, or as a consequence of differential levels of precursors for the hypusination reactions (e.g., spermidine and trypanothione), both of which alter BZ's effects in the parasite.

Infection of Anopheles aquasalis from symptomatic and asymptomatic Plasmodium vivax infections in Manaus, western Brazilian Amazon.

BACKGROUND: Asymptomatic individuals are one of the major challenges for malaria elimination programs in endemic areas. In the absence of clinical symptoms and with a lower parasite density they constitute silent reservoirs considered important for maintaining transmission of human malaria. Studies from Brazil have shown that infected individuals may carry these parasites for long periods. RESULTS: Patients were selected from three periurban endemic areas of the city of Manaus, in the western Brazilian Amazon. Symptomatic and asymptomatic patients with positive thick blood smear and quantitative real-time PCR (qPCR) positive for Plasmodium vivax were invited to participate in the study. A standardised pvs25 gene amplification by qPCR was used for P. vivax gametocytes detection. Anopheles aquasalis were fed using membrane feeding assays (MFA) containing blood from malaria patients. Parasitemia of 42 symptomatic and 25 asymptomatic individuals was determined by microscopic examination of blood smears and qPCR. Parasitemia density and gametocyte density were assessed as determinants of infection rates and oocysts densities. A strong correlation between gametocyte densities (microscopy and molecular techniques) and mosquito infectivity (P < 0.001) and oocysts median numbers (P < 0.05) was found in both groups. The ability to infect mosquitoes was higher in the symptomatic group (41%), but infectivity in the asymptomatic group was also seen (1.42%). CONCLUSIONS: Although their infectivity to mosquitoes is relatively low, given the high prevalence of P. vivax asymptomatic carriers they are likely to play and important role in malaria transmission in the city of Manaus. The role of asymptomatic infections therefore needs to be considered in future malaria elimination programs in Brazil.

Overexpression of eukaryotic initiation factor 5A (eIF5A) affects susceptibility to benznidazole in Trypanosoma cruzi populations

Eukaryotic initiation factor 5A (eIF5A) is a conserved protein with an essential role in translation elongation. Using one and two-dimensional western blotting, we showed that the eIF5A protein level was 2-fold lower in benznidazole (BZ)-resistant (BZR and 17LER) Trypanosoma cruzi populations than in their respective susceptible counterparts (BZS and 17WTS). To confirm the role of eIF5A in BZ resistance, we transfected BZS and 17WTS with the wild-type eIF5A or mutant eIF5A-S2A (in which serine 2 was replaced by alanine). Upon overexpressing eIF5A, both susceptible lines became approximately 3- and 5-fold more sensitive to BZ. In contrast, the eIF5A-S2A mutant did not alter its susceptibility to BZ. These data suggest that BZ resistance might arise from either decreasing the translation of proteins that require eIF5A, or as a consequence of differential levels of precursors for the hypusination reactions (e.g., spermidine and trypanothione), both of which alter BZ's effects in the parasite.

Plasmodium yoelii nigeriensis (N67) Is a Robust Animal Model to Study Malaria Transmission by South American Anopheline Mosquitoes.

Malaria is endemic in the American continent and the Amazonian rainforest is the region with the highest risk of transmission. However, the lack of suitable experimental models to infect malaria vectors from the Americas has limited the progress to understand the biology of transmission in this region. Anopheles aquasalis, a major vector in coastal areas of South America, was found to be highly refractory to infection with two strains of Plasmodium falciparum (NF54 and 7G8) and with Plasmodium berghei (mouse malaria), even when the microbiota was eliminated with antibiotics and oxidative stress was reduced with uric acid. In contrast, An. aquasalis females treated with antibiotics and uric acid are susceptible to infection with a second murine parasite, Plasmodium yoelii nigeriensis N67 (PyN67). Anopheles albimanus, one of the main malaria vectors in Central America, Southern Mexico and the Caribbean, was more susceptible to infection with PyN67 than An. aquasalis, even in the absence of any pre-treatment, but was still less susceptible than Anopheles stephensi. Disruption of the complement-like system in An. albimanus significantly enhanced PyN67 infection, indicating that the mosquito immune system is mounting effective antiplasmodial responses. PyN67 has the ability to infect a broad range of anophelines and is an excellent model to study malaria transmission by South American vectors.

Caracterização da madeira de quatro espécies florestais / Characterization of wood of four forest species

O conhecimento das relações existentes entre a estrutura anatômica da madeira com suas propriedades físicas ou mecânicas é importante para seu uso adequado. Este trabalho teve como objetivo caracterizar a anatomia microscópica e propriedades físicas da madeira de quatro diferentes espécies florestais. A madeira estudada foi proveniente das seguintes espécies: Cedrela fissilis (Cedro), Híbrido clonal Eucalyptus urophylla × Eucalyptus grandis (Eucalipto urograndis), Hovenia dulcis (Uva do Japão) e Gallesia integrifolia (Pau d'alho). Para a determinação da retratibilidade, utilizou-se a norma MB26/40 da ABNT (1940); as dimensões lineares foram obtidas com palmer, precisão de 0,001mm. O estudo da anatomia da madeira seguiu as recomendações da norma de procedimento em estudos de anatomia de madeira, da COPANT (1974) e também da IAWA (1989). Os caracteres anatômicos avaliados foram: diâmetro tangencial (µm) e frequência de vasos (nomm-2); comprimento de fibra (µm), diâmetro de lume (µm) e espessura de parede de fibra (µm); altura (µm), largura (µm) e frequência de raios (nomm-1). Os valores do coeficiente anisotrópico foram de 1,16; 1,77; 1,81 e 1,84 para a madeira de C. fissilis, H. dulcis, Híbrido clonal e G. integrifolia, respectivamente, demonstrando que a madeira de C. fissilis possui elevada estabilidade dimensional e as demais madeiras, valores aceitáveis para esse coeficiente.

This study aimed to characterize the microscopic anatomy and physical properties of wood from four different forest species. The wood has been studied from the following species: Cedrela fissilis, Crossbreed clone Eucalyptus urophylla × Eucalyptus grandis, Hovenia dulcis and Gallesia integrifolia. To determine the shrinkage it was used the standard of MB26/40 of ABNT (1940), the linear dimensions were obtained with palmer, accuracy of 0.001mm. The study of wood anatomy followed the recommendations of standard procedure in studies of anatomy of wood, COPANT (1974) and also the IAWA (1989). The anatomical characters evaluated were: tangential diameter (µm) and frequency of vessels (nomm-2), fiber length (µm), diameter of lumen (µm) and wall thickness of fiber (µm), height (µm), width (µm) and frequency of rays (nomm-1). The anisotropic factor values were of 1.17, 1.83, 1.89 and 1.90 for C. fissilis, H. dulcis, Crossbreed clone and G. integrifolia, respectively, showing that the C. fissilis wood has high stability dimensional and wood other acceptable values for this coefficient.

Caracterização da madeira de quatro espécies florestais / Characterization of wood of four forest species

O conhecimento das relações existentes entre a estrutura anatômica da madeira com suas propriedades físicas ou mecânicas é importante para seu uso adequado. Este trabalho teve como objetivo caracterizar a anatomia microscópica e propriedades físicas da madeira de quatro diferentes espécies florestais. A madeira estudada foi proveniente das seguintes espécies: Cedrela fissilis (Cedro), Híbrido clonal Eucalyptus urophylla × Eucalyptus grandis (Eucalipto urograndis), Hovenia dulcis (Uva do Japão) e Gallesia integrifolia (Pau d'alho). Para a determinação da retratibilidade, utilizou-se a norma MB26/40 da ABNT (1940); as dimensões lineares foram obtidas com palmer, precisão de 0,001mm. O estudo da anatomia da madeira seguiu as recomendações da norma de procedimento em estudos de anatomia de madeira, da COPANT (1974) e também da IAWA (1989). Os caracteres anatômicos avaliados foram: diâmetro tangencial (µm) e frequência de vasos (nomm-2); comprimento de fibra (µm), diâmetro de lume (µm) e espessura de parede de fibra (µm); altura (µm), largura (µm) e frequência de raios (nomm-1). Os valores do coeficiente anisotrópico foram de 1,16; 1,77; 1,81 e 1,84 para a madeira de C. fissilis, H. dulcis, Híbrido clonal e G. integrifolia, respectivamente, demonstrando que a madeira de C. fissilis possui elevada estabilidade dimensional e as demais madeiras, valores aceitáveis para esse coeficiente.

This study aimed to characterize the microscopic anatomy and physical properties of wood from four different forest species. The wood has been studied from the following species: Cedrela fissilis, Crossbreed clone Eucalyptus urophylla × Eucalyptus grandis, Hovenia dulcis and Gallesia integrifolia. To determine the shrinkage it was used the standard of MB26/40 of ABNT (1940), the linear dimensions were obtained with palmer, accuracy of 0.001mm. The study of wood anatomy followed the recommendations of standard procedure in studies of anatomy of wood, COPANT (1974) and also the IAWA (1989). The anatomical characters evaluated were: tangential diameter (µm) and frequency of vessels (nomm-2), fiber length (µm), diameter of lumen (µm) and wall thickness of fiber (µm), height (µm), width (µm) and frequency of rays (nomm-1). The anisotropic factor values were of 1.17, 1.83, 1.89 and 1.90 for C. fissilis, H. dulcis, Crossbreed clone and G. integrifolia, respectively, showing that the C. fissilis wood has high stability dimensional and wood other acceptable values for this coefficient.

Caracterização da madeira de quatro espécies florestais / Characterization of wood of four forest species

O conhecimento das relações existentes entre a estrutura anatômica da madeira com suas propriedades físicas ou mecânicas é importante para seu uso adequado. Este trabalho teve como objetivo caracterizar a anatomia microscópica e propriedades físicas da madeira de quatro diferentes espécies florestais. A madeira estudada foi proveniente das seguintes espécies: Cedrela fissilis (Cedro), Híbrido clonal Eucalyptus urophylla × Eucalyptus grandis (Eucalipto urograndis), Hovenia dulcis (Uva do Japão) e Gallesia integrifolia (Pau d'alho). Para a determinação da retratibilidade, utilizou-se a norma MB26/40 da ABNT (1940); as dimensões lineares foram obtidas com palmer, precisão de 0,001mm. O estudo da anatomia da madeira seguiu as recomendações da norma de procedimento em estudos de anatomia de madeira, da COPANT (1974) e também da IAWA (1989). Os caracteres anatômicos avaliados foram: diâmetro tangencial (µm) e frequência de vasos (nomm-2); comprimento de fibra (µm), diâmetro de lume (µm) e espessura de parede de fibra (µm); altura (µm), largura (µm) e frequência de raios (nomm-1). Os valores do coeficiente anisotrópico foram de 1,16; 1,77; 1,81 e 1,84 para a madeira de C. fissilis, H. dulcis, Híbrido clonal e G. integrifolia, respectivamente, demonstrando que a madeira de C. fissilis possui elevada estabilidade dimensional e as demais madeiras, valores aceitáveis para esse coeficiente.(AU)

This study aimed to characterize the microscopic anatomy and physical properties of wood from four different forest species. The wood has been studied from the following species: Cedrela fissilis, Crossbreed clone Eucalyptus urophylla × Eucalyptus grandis, Hovenia dulcis and Gallesia integrifolia. To determine the shrinkage it was used the standard of MB26/40 of ABNT (1940), the linear dimensions were obtained with palmer, accuracy of 0.001mm. The study of wood anatomy followed the recommendations of standard procedure in studies of anatomy of wood, COPANT (1974) and also the IAWA (1989). The anatomical characters evaluated were: tangential diameter (µm) and frequency of vessels (nomm-2), fiber length (µm), diameter of lumen (µm) and wall thickness of fiber (µm), height (µm), width (µm) and frequency of rays (nomm-1). The anisotropic factor values were of 1.17, 1.83, 1.89 and 1.90 for C. fissilis, H. dulcis, Crossbreed clone and G. integrifolia, respectively, showing that the C. fissilis wood has high stability dimensional and wood other acceptable values for this coefficient.(AU)

In vitro susceptibility of environmental isolates of Exophiala dermatitidis to five antifungal drugs.

Several dematiaceous fungi frequently isolated from nature are involved in cases of superficial lesions to lethal cerebral infections. Antifungal susceptibility data on environmental and clinical isolates are still sparse despite the advances in testing methods. The objective of this study was to examine the activities of 5-flucytosine, amphotericin B, itraconazole, voriconazole and terbinafine against environmental isolates of Exophiala strains by minimum inhibition concentration (MIC) determination. The strains were obtained from hydrocarbon-contaminated soil, ant cuticle and fungal pellets from the infrabuccal pocket of attine gynes. Broth microdilution assay using M38-A2 reference methodology for the five antifungal drugs and DNA sequencing for fungal identification were applied. Terbinafine was the most active drug against the tested strains. It was observed that amphotericin B was less effective, notably against Exophiala spinifera, also studied. High MICs of 5-flucytosine against Exophiala dermatitidis occurred. This finding highlights the relevance of studies on the antifungal resistance of these potential opportunistic species. Our results also contribute to a future improvement of the standard methods to access the drug efficacy currently applied to black fungi.

Development of Leishmania (Leishmania) infantum chagasi in its natural sandfly vector Lutzomyia longipalpis.

We analyzed the development of Leishmania (Leishmania) infantum chagasi in its natural sandfly vector Lutzomyia longipalpis. In addition, we compared sandfly infections initiated with axenic amastigotes or promastigotes. Our data showed no important difference between Lu. longipalpis infection rates resulting from either type of infections. Furthermore, development of infection was equivalent in both cases. All promastigote forms were found inside the sandfly and, after blood digestion, most of the population consisted of procyclics and nectomonads. A low percentage of metacyclic forms was coincident with a high number of nectomonads during late stages of infection, but which form gives rise to metacyclic forms in L. infantum chagasi is unknown. These results also show that the promastigote infection model, at least for this situation, is suitable for obtaining of infected sandflies because it is easier and less laborious.

Papel de dissialogangliosídeos na progressão tumoral de melanomas / Role of disialoganglioside in melanoma tumor progression

Na progressão tumoral, células de melanoma acumulam derivados de dissialogangliosídeos. A função desses glicoconjugados na progressão do tumor ainda é desconhecida. Tem-se estudado um possível papel de dissialogangliosídeos na migração celular. A linhagem celular de melanócito, melan-a, foi usada como modelo para a expressão do gene da GD3-sintase (ST8Sia I), a qual é a única enzima conhecida na conversão de GM3 no gangliosídio associado a tumor, GD3... Essas células também foram mais migratórias do que as células GM3+/GD3-, sugerindo que GM3 tem um papel negativo na migração celular. Depois foi examinado o efeito da adição de gangliosídeos exógenos. A adição de GM3 em células derivadas de melan-a também inibiu a migração celular; enquanto que a adição de GD3 a promoveu a migração. Juntos, nossos resultados sugerem que a razão entre GM3 e GD3 em melanócitos mostra um papel modulatório na motilidade celular dependente de integrina. Nós também mostramos a papel pró-apoptótico de GD3 em células de melanoma murino (TM1). Uma vez que, o insucesso de transfecção da expressão estável de GD3 sintase em TM1 pode ser devido a sensibilização destas células a morte celular na presença de uma superexpressão de GD3. As células sobreviventes seriam aquelas que adquiriam a capacidade de modificar o seu produto da GD3 sintase para um dos seus derivados, não-apoptogênico. Desta forma, nós propomos que a persistência da expressão de GD3 pode selecionar células resistentes a apoptose, as quais, por sua vez adquiririam um fenótipo mais migratório...(aU)

Upon tumor progression, melanoma cells accumulate disialoganglioside derivatives. The function of these molecules in tumor progression remains unknown. To address possible functions of the disialoganglioside G03 , the murine melanocyte cell line, melan-a, was transfected with the G03 synthase gene (ST8Sia 1). In melan-a transfectants, disialogangliosides modulated melanocyte cell adhesion and migration. Ali transfectants displayed equivalent . . + + leveis of 1ntegnns on the cell surface. GM3 /G03 melanocytes tended to adhere and migrate more towards laminin-1 coated surfaces than GM3 +/G03- cells. Depletion of glycosphingolipids, using phenyl-palmitoylamino-pirrolidinopropanol (PPPP), rendered cells (LacCer-)/GM3- /G03-.These latter cells were also more migratory than GM3 +fG03- cells, suggesting that GM3 plays a negative role in cell migration. We next examined the effect of exogenously added gangliosides. Addition of GM3 to melan-a cells also inhibited cell migration; whereas exogenously added G03 promoted it. Taken together, our results suggest that the ratio between GM3 and G03 in melanocytes modulates migration. We have also uncovered a pro-apoptogenic function of G03 in murine melanomas, as we failed to achieve stable expression of G03 in melanoma cells due to their increased sensitivity to cell death inducing agents. Failure of maintaining high expression of G03 in murine melanoma cells was associated with de novo expression of GM2/Go2 synthase gene. This gene converts G03 in Go2. GM2/Go2 synthase gene expression could warrant survival of G03 synthase expressing cells, by consuming Go3 and therefore releasing cells from the pro-apoptogenic effect of this ganglioside (AU)