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UNLABELLED: The bactericidal activity (minimum inhibitory concentration (MIC)-test) of Ocimum americanum (inflorescences) essential oil (OAEO) against Aeromonas hydrophila was determined in this study. Also investigated was the potential of OAEO and the main compound found in the oil (linalool) at subinhibitory concentrations to be inhibitors of haemolysis caused by Aer. hydrophila in fish erythrocytes. An in vivo experiment was conducted to evaluate the survival of fish (Rhamdia quelen) experimentally infected with Aer. hydrophila and exposed to OAEO. A second experiment was conducted to evaluate the in vitro and in vivo activity of OAEO (mix from inflorescences and leaves) against the parasite Gyrodactylus sp. The OAEO showed weak in vitro activity against Aer. hydrophila (6400 µg ml(-1) ). Subinhibitory concentrations of OAEO (100 µg ml(-1) ) inhibited haemolysis (90%) caused by Aer. hydrophila in fish erythrocytes, however, linalool did not inhibit haemolysis activity. At the low concentrations (10 and 20 mg l(-1) ) added to the water, OAEO promoted the survival of fish experimentally infected with Aer. hydrophila. Lastly, the OAEO mix (50 mg l(-1) ) was effective against Gyrodactylus sp., significantly reducing (60%) the number of parasites in the fish. SIGNIFICANCE AND IMPACT OF THE STUDY: Phytochemicals, such as essential oils (EOs) are a great source of new molecules and have shown potential to be used in aquaculture systems. However, additional studies focused on the in vivo efficacy, mode of action and identification of the active compounds are needed. This study determined the potential of Ocimum americanum EO for use against two important fish pathogens, Aeromonas hydrophila and Gyrodactylus sp., as well as providing preliminary information about the role of the main EO compound (linalool) against Aer. hydrophila virulence.

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RESUMOA variação nos elementos meteorológicos ao longo do ano, configurando as quatro estações, proporciona diferentes condições de crescimento e desenvolvimento das plantas, alterando o metabolismo e a constituição dos tecidos vegetais. Assim, o presente trabalho teve o objetivo de determinar a influência da sazonalidade em parâmetros fenométricos e na produção de óleo essencial em Aloysia triphylla (L'Hérit) Britton, submetida a diferentes níveis de reposição hídrica cultivada em ambiente protegido. As avaliações foram realizadas no dia que marcou a metade de cada estação do ano (verão, outono, inverno e primavera), sendo coletado todo o material vegetativo 20 cm acima do solo. A reposição hídrica foi baseada na evapotranspiração de referência (ETo) para o ambiente externo em função dos dados de entrada da equação de Penman-Monteith a qual apresenta parametrizações para dados obtidos em estações meteorológicas em padrões oficiais, sendo assim aplicados 125, 100, 75 e 50% da ETo em turno de rega de dois dias. A produção de massa fresca, seca e de parte aérea, bem como a área foliar, apresentaram maiores valores na estação primavera, sendo o inverno e o verão responsáveis pelos menores valores. O maior teor de óleo essencial foi observado nas estações de menor produção de biomassa, ou seja, verão e inverno. A reposição hídrica que proporcionou maior produção de material vegetativo foi a de 125% da ETo; no entanto, o maior teor de óleo foi observado nas menores reposições hídricas (75 e 50 % da ETo, respectivamente). A produção de óleo foi maior na primavera, a qual não sofreu influência da reposição hídrica ao longo do ano.

ABSTRACTThe variation in weather elements throughout the year, setting the four seasons, provides different conditions for growth and development of plants, altering the metabolism and the structure of plants` tissues. This study aimed to determine the influence of seasonality on fenometrics parameters and on the oil production in Aloysia triphylla (L'Herit) Britton, subjected to different levels of water availability cultivated in greenhouse conditions. The evaluations were made on the day that marked the middle of each season (summer, autumn, winter and spring), and all plant material were collected 20 cm above ground. The water reposition was based on the evapotranspiration reference (ETo) to the external environment being applied 125, 100, 75 and 50% of ETo in an irrigation interval of two days. The production of fresh, dry and aerial part mass, as well as leaf areamass, showed higher values in the spring season, while winter and summer were responsible for lower values. The highest content of essential oil was observed at seasons with lower biomass production. The water availability that provided higher production of plant material was the one with 125% of ETo, however, the highest oil content was observed at lower water availability (75% and 50% of ETo, respectively). The oil production was higher in the spring and was not affected throughout the year by the water availability.

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Os fatores ambientais, tais como: temperatura do ar, umidade relativa do ar e radiação solar, influenciam no comportamento fisiológico dos vegetais refletindo no seu crescimento e desenvolvimento. O objetivo do trabalho foi avaliar o comportamento fisiológico em mudas de pata-de-vaca ao longo do dia e constatar qual o melhor horário para a realização de determinações de trocas gasosas. Para tanto, foram realizadas avaliações de temperatura da folha, radiação fotossinteticamente ativa, resistência estomática e transpiração, utilizando-se um porômetro, das 8:00 às 17:00 horas, em intervalos de uma hora entre as medidas. A espécie apresenta oscilações no seu mecanismo fisiológico em função do horário de avaliação e das condições climáticas, sendo o intervalo mais indicado para a realização de determinações das trocas gasosas das 10:00 às 13:00 horas.

Environmental elements, such as air temperature, relative humidity and solar radiation, affect the physiological behavior of plants, which is reflected in their growth and development. The objective of this study was to evaluate the physiological changes of Brazilian Orchid Tree seedlings over a typical day and find the best time to carry out determinations of gas exchanges. For this end, we evaluated temperature of the leaf, photosynthetically active radiation, stomatal resistance and perspiration, using a porometer, from 8:00 a.m. to 05:00 p.m., in intervals of one hour between measurements. The species presents oscillations in its physiologic mechanism in function of the time of evaluation and climatic conditions, being the most suitable interval to determine gas exchanges from 10:00 a.m. to 01:00 p.m.

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The objective of this study was to identify the possible involvement of the GABAergic system in the anesthetic effect of Lippia alba essential oil (EO). We propose a new animal model using silver catfish (Rhamdia quelen) exposed to an anesthetic bath to study the mechanism of action of EO. To observe the induction and potentiation of the anesthetic effect of EO, juvenile silver catfish (9.30 ± 1.85 g; 10.15 ± 0.95 cm; N = 6) were exposed to various concentrations of L. alba EO in the presence or absence of diazepam [an agonist of high-affinity binding sites for benzodiazepinic (BDZ) sites coupled to the GABA A receptor complex]. In another experiment, fish (N = 6) were initially anesthetized with the EO and then transferred to an anesthetic-free aquarium containing flumazenil (a selective antagonist of binding sites for BDZ coupled to the GABA A receptor complex) or water to assess recovery time from the anesthesia. In this case, flumazenil was used to observe the involvement of the GABA-BDZ receptor in the EO mechanism of action. The results showed that diazepam potentiates the anesthetic effect of EO at all concentrations tested. Fish exposed to diazepam and EO showed faster recovery from anesthesia when flumazenil was added to the recovery bath (12.0 ± 0.3 and 7.2 ± 0.7, respectively) than those exposed to water (9.2 ± 0.2 and 3.5 ± 0.3, respectively). In conclusion, the results demonstrated the involvement of the GABAergic system in the anesthetic effect of L. alba EO on silver catfish.

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The objective of this study was to identify the possible involvement of the GABAergic system in the anesthetic effect of Lippia alba essential oil (EO). We propose a new animal model using silver catfish (Rhamdia quelen) exposed to an anesthetic bath to study the mechanism of action of EO. To observe the induction and potentiation of the anesthetic effect of EO, juvenile silver catfish (9.30 ± 1.85 g; 10.15 ± 0.95 cm; N = 6) were exposed to various concentrations of L. alba EO in the presence or absence of diazepam [an agonist of high-affinity binding sites for benzodiazepinic (BDZ) sites coupled to the GABA A receptor complex]. In another experiment, fish (N = 6) were initially anesthetized with the EO and then transferred to an anesthetic-free aquarium containing flumazenil (a selective antagonist of binding sites for BDZ coupled to the GABA A receptor complex) or water to assess recovery time from the anesthesia. In this case, flumazenil was used to observe the involvement of the GABA-BDZ receptor in the EO mechanism of action. The results showed that diazepam potentiates the anesthetic effect of EO at all concentrations tested. Fish exposed to diazepam and EO showed faster recovery from anesthesia when flumazenil was added to the recovery bath (12.0 ± 0.3 and 7.2 ± 0.7, respectively) than those exposed to water (9.2 ± 0.2 and 3.5 ± 0.3, respectively). In conclusion, the results demonstrated the involvement of the GABAergic system in the anesthetic effect of L. alba EO on silver catfish.

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Dengue virus currently causes 50-100 million infections annually. Comprehensive knowledge about the evolution of Dengue in response to selection pressure is currently unavailable, but would greatly enhance vaccine design efforts. In the current study, we sequenced 187 new dengue virus serotype 3 (DENV-3) genotype III whole genomes isolated from Asia and the Americas. We analyzed them together with previously-sequenced isolates to gain a more detailed understanding of the evolutionary adaptations existing in this prevalent American serotype. In order to analyze the phylogenetic dynamics of DENV-3 during outbreak periods; we incorporated datasets of 48 and 11 sequences spanning two major outbreaks in Venezuela during 2001 and 2007-2008, respectively. Our phylogenetic analysis of newly sequenced viruses shows that subsets of genomes cluster primarily by geographic location, and secondarily by time of virus isolation. DENV-3 genotype III sequences from Asia are significantly divergent from those from the Americas due to their geographical separation and subsequent speciation. We measured amino acid variation for the E protein by calculating the Shannon entropy at each position between Asian and American genomes. We found a cluster of seven amino acid substitutions having high variability within E protein domain III, which has previously been implicated in serotype-specific neutralization escape mutants. No novel mutations were found in the E protein of sequences isolated during either Venezuelan outbreak. Shannon entropy analysis of the NS5 polymerase mature protein revealed that a G374E mutation, in a region that contributes to interferon resistance in other flaviviruses by interfering with JAK-STAT signaling was present in both the Asian and American sequences from the 2007-2008 Venezuelan outbreak, but was absent in the sequences from the 2001 Venezuelan outbreak. In addition to E, several NS5 amino acid changes were unique to the 2007-2008 epidemic in Venezuela and may give additional insight into the adaptive response of DENV-3 at the population level.

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El objetivo del presente estudio fue examinar cómo se relacionaban el temor hacia la muerte reportado por adolescentes y su actitud hacia la donación de órganos post-mortem. Se hipotetizó que mayores niveles de temor hacia la muerte se asociarían con actitudes más negativas hacia la donación, y que se presentarían diferencias en cuanto a la actitud hacia la donación dependiendo del género, nivel socioeconómico familiar y nivel educacional de los padres de los adolescentes. Se aplicó el Cuestionario de Actitud General hacia la Donación de Órganos (CADO) y la Escala de Temor hacia la Muerte de Collet-Lester (CL-FODS) a 101 adolescentes que cursaban educación media en las ciudades de Concepción y San Pedro de la Paz, Chile. Los resultados del estudio corroboraron parcialmente la H1, pero no dieron respaldo a las hipótesis que relacionaban el género, los niveles socioeconómicos familiares y los niveles de escolaridad parentales con la actitud hacia la donación de órganos.

The objective of this study was to examine how the fear of death reported by adolescents and their attitude towards donating post-mortem organs were related. It was hypothesized that higher levels of fear of death would be associated with more negative attitudes towards donation, and that differences in attitude towards donation would be presented depending on the gender, family socioeconomic level and educational level of the parents of adolescents. The General Attitude Questionnaire towards Organ Donation (CADO) and the Scale of Death Fear of Collet-Lester (CL-FODS) were applied to 101 adolescents attending secondary education in the cities of Concepción and San Pedro de la Paz , Chile. The results of the study partially corroborated H1, but did not support the hypotheses that related gender, family socioeconomic levels and parental education levels to the attitude towards organ donation.

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BACKGROUND: Infections caused by Varicella Zoster virus in children with cancer have a high rate of complications and mortality. AIM: To report the outcome of this infection in children with cancer. PATIENTS AND METHODS: Retrospective analysis of medical records of 216 children aged less than 15 years old with the diagnosis of an hematological or solid tumor, admitted to the National Program of Antineoplastic Drugs (PINDA). RESULTS: Eighty seven children had a Varicella Zoster virus infections, 73 (84 per cent) had varicella, 8 (9 per cent) had herpes zoster and 6 (7 per cent) had varicella and herpes zoster. Ninety four percent acquired the infection during antineoplastic treatment and 78 per cent received Acyclovir as antiviral therapy. During a nosocomial outbreak of varicella, three patients with an Acute Lymphoblastic leukemia died in the initial phase of chemotherapy, in spite of an early administration of Acyclovir. No patient with herpes zoster died. CONCLUSIONS: The incidence of varicella was higher in children with leukemia or lymphoma than in children with other types of cancer. Virus reactivation was uncommon and had a benign course. Varicella mortality in these children could be favorably modified through an active immunization of immunocompetent children.

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