Epithelial cells treated with genistein inhibit adhesion and endocytosis of Paracoccidioides brasiliensis

Paracoccidioidomycosis is caused by Paracoccidioides brasiliensis, which although not formally considered an intracellular pathogen, can be internalized by epithelial cells in vitro and in vivo. The mechanisms used by P. brasiliensis to adhere to and invade non-professional phagocytes have not been identified. The signal-transduction networks, involving protein tyrosine kinase (PTK) and protein phosphatase activities, can modulate crucial events during fungal infections. In this study, the involvement of PTK has been investigated in P. brasiliensis adherence and invasion in mammalian epithelial cells. A significant inhibition of the fungal invasion occurred after the pre-treatment of the epithelial cells with genistein, a specific tyrosine kinase inhibitor, indicating that the tyrosine kinase pathway is involved in P. brasiliensis internalization. In contrast, when the fungus was treated, a slight (not significant) inhibition of PTK was observed, suggesting that PTK might not be the fungus' transduction signal pathway during the invasion process of epithelial cells. An intense PTK immunofluorescence labeling was observed in the periphery of the P. brasiliensis infected cells, little PTK labeling was found in both uninfected cells and yeast cells, at later infection times (8 and 24 h). Moreover, when the epithelial cells were treated with genistein and infected with P. brasiliensis, no labeling was observed, suggesting the importance of the PTK in the infectious process. These results suggest that PTK pathway participates in the transduction signal during the initial events of the adhesion and invasion processes of P. brasiliensis to mammalian epithelial cells.

Dinâmica de reprodução e comportamento reprodutivo de branchoneta Dendrocephalus brasiliensis Pesata, 1921 como incremento na produção de alimento vivo para peixes ornamentais

Reproductive behavior of Dendrocephalus brasiliensis Pesta, 1921(Crustacean: Anostracan). The reproductive behavior of fresh water Anostracan has been poorly investigated in carcinology specialized literature, specifically in relation to Dendrocephlaus brasiliensis Pesta, 1921, with abundant data just about the geographical distribution of that Anostracan. The objective of this work was to know the reproductive behavior of this Anostracan, in different seasons (dry and raine). For this, ripe individuals of both sexes were collected in four pond of the of Fish farming Station of Paulo Afonso (EPPA), through monthly captures in each ponds, from December 2004 to November 2005. The type of reproduction was observed after the placing in aquariums (a) of then with males and (b) other on individually, at the nauplii phase, where they stayed for 15 days until the reproductive age. The sexual proportion was calculated through the relative frequencies of males and females, every month, for the whole collection period during 10 days. the production of cysts was related to the size of the female. The male: female ratio in the study period was 1 male:1,07 female. The proportion male:female was from 48,25% : 51,75% along the year. Concerning the type of reproduction, it was observed that this specie is characteerized by sexual reproduction

Estratégia reprodutiva do peixe-voador, Hirundichthys affinis e do peixe agulha preta, Hemiramphus brasiliensis no litoral de Caiçara do Norte, Rio Grande do Norte, Brasil

The flyingfish, Hirundichthys affinis (Günther, 1866) (Exocoetidae) and ballyhoo half beak, Hemiramphus brasiliensis (Linnaeus, 1758) (Hemiramphidae) are marine fish species of commercial value, which contribute to artisanal fishery production of Rio Grande do Norte, Brazil. Besides the economic importance, these fish are important from an ecological point of view, being components in pelagic food chain, where they are the preferred prey of larger predators of high commercial value. This study aimed to determine the reproductive strategies of H. affinis and H. brasiliensis and the fishery production of H. affinis in the northern coast of Rio Grande do Norte. The results are presented in the form of six cientific articles and a review paper. The first article presents the morphometric measurements and meristic counts which confirmed the taxonomic status, population structure in length-weight and the gonad development of H. affinis through macroscopic observations of the ovaries and testes. Females of this species were bigger and heavier than males. The second article describes the reproductive tactics, such as, sex ratio, length at first sexual maturity, histological aspects of gonads, fecundity and spawning season, that indicate the reproductive strategy of H. affinis. The third article shows annual changes in the fishery production of H. affinis in Caiçara do Norte, during the period of 1993 to 2010, emphasizing the relevance of this fish in total fishery production of Rio Grande do Norte, besides registering the fall in production in the years 2008 to 2010. The fourth article describes the population structure, with respect to the length and weight, the length-weight relationship, growth type and sex ratio of Hemiramphus brasiliensis. The fifth article describes the reproductive biology of H. brasiliensis, with details about sex ratio, length at first sexual maturity, fecundity, type of breeding and spawning season. The sixth article deals with the reproductive strategy of H. brasiliensis. The review paper presents the topic of age determination of tropical fish using analysis of otoliths. Both species use the coastal waters of Caiçara do Norte for reproductive purposes. The flying fish, H. affinis migrates from the oceanic waters to the coastal waters to reproduce, coinciding with the rainy season. H. affinis presents total spawning and a seasonal reproductive strategy. However, H. brasiliensis lives and reproduces in the coastal waters displaying partial spawning and an equilibrium reproductive strategy

A comparative study of the non-isothermal degradation of natural rubber from Mangabeira (Hancornia speciosa Gomes) and Seringueira (Hevea brasiliensis)

Due to the increasing search for alternative sources of natural rubber (NR) whose properties are similar to Hevea brasiliesis, several sources have been studied in the past few years. Among them, Mangabeira (Hancornia speciosa Gomes), which is native to Amazon rainforest and other regions of Brazil, has a potential as another viable rubber source. As a continuation of a series of comparative studies between Hancornia and Hevea (clone RRIM 600) these two species by our research team, their thermal behavior was analyzed by thermogravimetry (TG) using Flynn-Wall-Ozawa's approach in order to obtain kinetic parameters (reaction order, pre-exponential factor and activation energy) of the decomposition process. Results indicated that the thermal behavior of NR from Hancornia was comparable to Hevea with some differences observed as follows: reaction order for Hancornia was higher than for Hevea at the beginning of degradation and very close for temperatures over 350 A degrees C; activation energy and pre-exponential factor had the same trend, i.e., increased with increasing degree of conversion remaining almost constant between 20 and 70% and then increasing for higher degrees, although Hevea was slightly more thermally stable than Hancornia. These major influences in the degradation process in the early stage are attributed to differences in non-rubber constituents present in these two species.

Comparative Study on the Technological Properties of Latex and Natural Rubber from Hancornia speciosa Gomes and Hevea brasiliensis

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Determinação de Ba, Cd, Cr, Cu, Ni, Pb, Sn e Zn em Tainha (Mugil brasiliensis) nos estuários potiguares

Heavy metals can cause problems of human poisoning by ingestion of contaminated food, and the environment, a negative impact on the aquatic fauna and flora. And for the presence of these metals have been used for aquatic animals biomonitoramento environment. This research was done in order to assess the environmental impact of industrial and domestic sewage dumped in estuaries potiguares, from measures of heavy metals in mullet. The methods used for these determinations are those in the literature for analysis of food and water. Collections were 20 samples of mullet in several municipality of the state of Rio Grande do Norte, from the estuaries potiguares. Were analyzed the content of humidity, ash and heavy metals. The data were subjected to two methods of exploratory analysis: analysis of the main components (PCA), which provided a multivariate interpretation, showing that the samples are grouped according to similarities in the levels of metals and analysis of hierarchical groupings (HCA), producing similar results. These tests have proved useful for the treatment of the data producing information that would hardly viewed directly in the matrix of data. The analysis of the results shows the high levels of metallic species in samples Mugil brasiliensis collected in Estuaries /Potengi, Piranhas/Açu, Guaraíra / Papeba / Arês and Curimataú

Nutritional and chemical composition of culinary-medicinal Royal Sun Agaricus (the Himematsutake mushroom) Agaricus brasiliensis S. Wasser et al. (agaricomycetideae)

The objective of the study was to determine the nutritional and chemical composition (carbohydrates, proteins, lipids, calcium, and iron), water and ash content, and the caloric value of powdered fruiting bodies from six strains and from a mixture of strains of the culinary-medicinal mushroom Agaricus brasiliensis. The Kruskal-Wallis nonparametric and multiple comparisons tests and the Pearson correlation coefficient were used, with a 5% significance level. First, the results showed that strain 99/30 had a similar nutritional composition to the mixed sample. Second, when comparing strain nutrients to the mixture nutrients, the highest levels of carbohydrates, proteins, and calcium were in strain 99/25, and the highest levels of lipids were in strains 97/11, 99/28, and 99/30. Strain 99/30 was highest both in caloric value and moisture content. Finally, the mixture was established as a good source of macronutrients and micronutrients, and strain 99/30 was the closest to the mixture in nutritional composition.

Injuries caused by scorpionfishes and (Scorpaena plumieri Bloch, 1789 Scorpaena brasiliensis Cuvier 1829) in the Southwestern Atlantic Ocean (Brazilian coast): epidemiologic, clinic and therapeutic aspects of 23 stings in humans

Fishes of the family Scorpaenidae are responsible for severe injuries and occasionally deaths in humans around the world. The more venomous fishes on the Brazilian coast and in the Southwestern Atlantic region are classified in the genus Scorpaena (family Scorpaenidae). However, there are few studies on the venomous apparatus, the effects of the venom, or clinical aspects of human envenoming provoked by Atlantic scorpionfishes.In this communication, the authors present 23 accidents caused by scorpionfishes of the genus Scorpaena among fishermen, and report the species that provoked the injuries, the circumstances of contacts, the clinical aspects observed and the therapeutic measures utilized for control of the symptoms of the victims. The intense pain and the systemic findings observed in the patients were very frequent and we think that the injuries provoked by scorpionfishes should be considered the most important manifestations caused by venomous fishes of the East Atlantic Ocean. (C) 2003 Elsevier B.V. Ltd. All rights reserved.

Modulatory effect of prostaglandins on human monocyte activation for killing of high- and low-virulence strains of Paracoccidioides brasiliensis

The effect of indomethacin (Indo), a cyclo-oxygenase inhibitor, on the monocyte-mediated killing of a low-(Pb265) and a high-(Pb18) virulence strain of Paracoccidioides brasiliensis was examined. The Pb18 strain was not killed by either non-activated or interferon-gamma (IFN-gamma)-activated human monocytes but these cells did show fungicidal activity if pretreated with Indo. In contrast with IFN-gamma tumour necrosis factor-alpha (TNF-alpha) was very effective at stimulating the fungicidal activity of monocytes. While the low-virulence strain, Pb265, could not be killed by monocytes, cells preincubated with IFN-gamma demonstrated fungicidal activity. The killing of this strain was also induced by pretreatment of monocytes with Indo. The results suggest a negative role for prostaglandins, which are synthesized via the cyclo-oxygenase pathway, in the regulation of monocyte-mediated killing of virulent and avirulent strains of P. brasiliensis and that TNF-alpha generation during the fungus-monocyte interaction is more important in the killing of Pb265 than Pb18.

Granulocyte macrophage colony-stimulating factor enhances the modulatory effect of cytokines on monocyte-derived multinucleated giant cell formation and fungicidal activity against Paracoccidioides brasiliensis

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Interleukin-15 increases Paracoccidioides brasiliensis killing by human neutrophils

Interleukin-15 is a pro-inflammatory cytokine produced by a wide range of different cell types, especially monocytes and macrophages, in response to infective agents, playing a crucial and modulatory role in innate and adaptive immune response. Infections by intracellular microorganisms such as some bacteria, protozoa and fungi point out the role of IL-15 in the activation of monocytes/macrophages and neutrophils, a process that represents an important defense mechanism in early periods of infection during the development of innate immune response. The aims of the present study were to evaluate the effects of IL-15 on human neutrophil fungicidal activity against a high virulent Paracoccidioides brasiliensis strain ( Pb18) and to verify whether this activity was mediated by oxidative metabolism such as the production of superoxide anion and H2O2 and if it was associated with an alteration of cytokine ( IL-8 and TNF-alpha) levels. Neutrophils from peripheral blood of healthy individuals were incubated in the presence and absence of IL-15 ( 12.5 - 250ng/ml) for 18h, at 37 degrees C, under tension of 5% CO2, then infected with Pb18 for 4h and evaluated for fungicidal activity, production of superoxide anion and H2O2, and quantification of cytokines IL-8 and TNF-a in the supernatant. Preincubation of neutrophils with IL-15 induced a significant increase in the fungicidal activity of such cells in a dose-dependent manner. After activation, there was an increase in the production of superoxide anion and H2O2 by these cells, suggesting participation of such metabolites in fungicidal activity. Catalase inhibits fungicidal activity, confirming the role of H2O2 in fungus killing. However, the levels of TNF-alpha and IL-8 were not modified after incubation with IL-15, which suggests that its role is not mediated by those cytokines. Taken together, results showed that IL-15 had a modulatory effect on human neutrophils infected in vitro with a high virulent strain of P. brasiliensis, which was characterized by an increased fungicidal activity mediated by a dependent mechanism of oxidative metabolism.

Production of prostaglandins and leukotrienes by Paracoccidioides brasiliensis

Paracoccidioides brasiliensis is the causative agent of paracoccidioidomycosis, the most prevalent deep mycosis in Latin America. Production of eicosanoids, including prostaglandins and leukotrienes, during fungal infections is theorized to play a critical role on fungal survival and/or growth as well as on host immune response modulation. Host cells are one source of these mediators; however another potential source may be the fungus itself. The purpose of our study was to assess whether P. brasiliensis strains with different degree of virulence (Pb18, Pb265, PbBT79, Pb192) produce both, prostaglandin E(2) (PGE(2)) and leukotriene B(4) (LTB(4)). Moreover, we asked if P. brasiliensis can use exogenous sources of arachidonic acid (AA), as well as metabolic pathways dependent on cyclooxygenase (COX) and lipoxygenase (5-LO) enzymes, for PGE(2) and LTB(4) production, respectively. Finally, a possible association between these eicosanoids and fungus viability was assessed. We demonstrated, using ELISA assays, that all P. brasiliensis strains, independently of their virulence, produce high PGE(2) and LTB(4) levels after a 4-hour culture, which were reduced after 8 hours. However, in both culture times, higher eicosanoids levels were detected when culture medium was supplemented with exogenous AA. Differently, treatment with indomethacin, a COX inhibitor, or MK886, a 5-LO inhibitor, induces a reduction on PGE(2) and LTB(4) levels, respectively, as well as in fungus viability. The data provide evidence that P. brasiliensis is able to metabolize either endogenous or exogenous AA by pathways that depend on COX and 5-LO enzymes for producing, respectively, PGE(2) and LTB(4) that are critical for its viability.

Killing of Paracoccidioides brasiliensis yeast cells by IFN-gamma and TNF-alpha activated murine peritoneal macrophages: evidence of H(2)O(2) and NO effector mechanisms

Paracoccidioidomycosis is a deep mycosis, endemic in Latin America, caused by Paracoccidioides brasiliensis. Macrophage activation by cytokines is the major effector mechanism against this fungus. This work aimed at a better understanding of the interaction between yeast cells-murine peritoneal macrophages and the cytokine signals required for the effective killing of high virulence yeast-form of P. brasiliensis. In addition, the killing effector mechanisms dependent on the generation of reactive oxygen or nitrogen intermediates were investigated. Cell preincubation with IFN-gamma or TNF-alpha, at adequate doses, resulted in effective yeast killing as demonstrated in short-term (4-h) assays. Both, IFN-gamma and TNF-alpha activation were associated with higher levels of H(2)O(2) and NO when compared to nonactivation. Treatment with catalase (CAT), a H(2)O(2) scavenger, and N(G)-monomethyl-L-arginine (L-NMMA), a nitric oxide synthase inhibitor, reverted the killing effect of activated cells. Taken together, these results suggest that both oxygen and L-arginine-nitric oxide pathways play a role in the killing of highly virulent P. brasiliensis.

Interleukin-6 treatment enhances human monocyte permissiveness for Paracoccidioides brasiliensis growth by modulating cytokine production

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Involvement of GABA(A)-benzodiazepine receptor in the anxiolytic effect induced by hexanic fraction of Rubus brasiliensis

To investigate the ability of hexanic ethanolic fraction of Rubus brasiliensis Martius (Roseceae), to induce anxiolytic effect and also the possible involvement of the GABA(A)-benzodiazepine receptor complex, male Wistar rats and Swiss mice behaviour were tested in the elevated plus maze (EPM). All the doses of the extract, 50, 100 and 150 mg/kg, administered per gavage (vo), 30 min before the behavioural evaluation, induced an anxiolytic effect expressed by: increased number of entries in and time spent in the open arms and percentage of open arm entries: and decreased number of entries and time spent in the closed arms. The treatment of mice with flumazenil (Ro 15-1788), 0.5, 1.0 and 1.5 mg/kg, i.p., 15-min before the administration of hexanic fraction, 100 mg/kg, vo, blocked the hexanic fraction-induced anxiolytic effect. The LD50 for the hexanic fraction was 1512 mg/kg. In conclusion, it was shown that the hexanic fraction of R. brasiliensis induced an anxiolytic effect in rats and mice. This effect can be attributed to a liposoluble principle with low toxicity which may be acting as an agonist on GABA(A)-benzodiazepine receptor complex. (C) 1998 Elsevier B.V. Ireland Ltd. All rights reserved.