Trypanosoma cruzi recognition by macrophages and muscle cells: perspectives after a 15-year study

Macrophages and muscle cells are the main targets for invasion of Trypanosoma cruzi. Ultrastructural studies of this phenomenon in vitro showed that invasion occurs by endocytosis, with attachment and internalization being mediated by different components capable of recognizing epi-or trypomastigotes (TRY). A parasitophorus vacuole was formed in both cell types, thereafter fusing with lysosomes. Then, the mechanism of T. cruzi invasion of host cells (HC) is essentially similar (during a primary infection in the abscence of a specific immune response), regardless of wether the target cell is a professional or a non-professional phagocytic cell. Using sugars, lectins, glycosidases, proteinases and proteinase inhibitors, we observed that the relative balance between exposed sialic acid and galactose/N-acetyl galactosamine (GAL) residues on the TRY surface, determines the parasite's capacity to invade HC, and that lectin-mediated phagocytosis with GAL specificity is important for internalization of T. cruzi into macrophages. On the other hand, GAL on the surface to heart muscle cells participate on TRY adhesion. TRY need to process proteolytically both the HC and their own surface, to expose the necessary ligands and receptors that allow binding to, and internalization in the host cell. The diverse range of molecular mechanisms which the parasite could use to invade the host cell may correspond to differences in the available "receptors"on the surface of each specific cell type. Acute phase components, with lectin or proteinase inhibitory activities (a-macroglobulins), may also be involved in T. cruzi-host cell interaction.

Comparison of purified 12 kDa and recombinant 15 kDa Fasciola hepatica antigens related to a Schistosoma mansoni fatty acid binding protein

Vaccines in schistosomiasis using homologous antigens have been studied extensively in experimentally infected mammalian hosts. Vaccines using heterologous antigens have received comparatively less attention. This review summarizes recent work on a heterologous 12 kDa Fasciola hepatica antigenic polypeptide which cross reacts with Schistosoma mansoni. A cDNA has been cloned and sequenced, and the predicted amino acid sequence of the recombinant protein has been shown to have significant (44) identity with a 14 kDa S. mansoni fatty acid binding protein. Thus in the parasitic trematodes fatty acid binding proteins may be potential vaccine candidates. The F. hepatica recombinant protein has been overexpressed and purified and denoted rFh15. Preliminary rFh15 migrates more slowly (i.e. may be slightly larger) than nFh12 on SDS-PAGE and has a predicted pI of 6.01 vs. observed pI of 5.45. Mice infected with F. hepatica develop antibodies to nFh12 by 2 weeks of infection vs. 6 weeks of infection to rFh15; on the other hand, mice with schistosomiasis mansoni develop antibodies to both nFh12 and rFh15 by 6 weeks of infection. Both the F. hepatica and S. mansoni cross-reactive antigens may be cross-protective antigens with the protection inducing capability against both species.

High and low doses of antimony (Sb v) in American cutaneous leishmaniasis: a five years follow-up study of 15 patients

Seventeen patients proceeding from the municipality of Rio de Janeiro, Brazil presenting with the cutaneous ulcerative form of American leishmaniasis were treated with one ampoule of pentavalent antimony daily for 30 days. With this regimen the individuals doses varies greatly: from 3.8 mg/kg of body weight to 22.3 mg/kg. After five years, patients receiving either a smaller dose or a bigger one, showed the same therapeutic result: cutaneous scars and no mucosal lesions.

Experimental chemotherapy for Chagas disease: 15 years of research contributions from in vivo and in vitro studies

Chagas disease, which is caused by the intracellular parasite Trypanosoma cruzi, is a neglected illness with 12-14 million reported cases in endemic geographic regions of Latin America. While the disease still represents an important public health problem in these affected areas, the available therapy, which was introduced more than four decades ago, is far from ideal due to its substantial toxicity, its limited effects on different parasite stocks, and its poor activity during the chronic phase of the disease. For the past 15 years, our group, in collaboration with research groups focused on medicinal chemistry, has been working on experimental chemotherapies for Chagas disease, investigating the biological activity, toxicity, selectivity and cellular targets of different classes of compounds on T. cruzi. In this report, we present an overview of these in vitro and in vivo studies, focusing on the most promising classes of compounds with the aim of contributing to the current knowledge of the treatment of Chagas disease and aiding in the development of a new arsenal of candidates with anti-T. cruzi efficacy.

Interleukin-15 augments oxidative metabolism and fungicidal activity of human monocytes against Paracoccidioides brasiliensis

Interleukin (IL)-15 is a pleiotropic cytokine that regulates the proliferation and survival of many cell types. IL-15 is produced by monocytes and macrophages against infectious agents and plays a pivotal role in innate and adaptive immune responses. This study analyzed the effect of IL-15 on fungicidal activity, oxidative metabolism and cytokine production by human monocytes challenged in vitro with Paracoccidioides brasiliensis (Pb18), the agent of paracoccidioidomycosis. Peripheral blood monocytes were pre-incubated with IL-15 and then challenged with Pb18. Fungicidal activity was assessed by viable fungi recovery from cultures after plating on brain-heart infusion-agar. Superoxide anion (O2-), hydrogen peroxide (H2O2), tumour necrosis factor-alpha (TNF-α), IL-6, IL-15 and IL-10 production by monocytes were also determined. IL-15 enhanced fungicidal activity against Pb18 in a dose-dependent pattern. This effect was abrogated by addition of anti-IL-15 monoclonal antibody. A significant stimulatory effect of IL-15 on O2- and H2O2 release suggests that fungicidal activity was dependent on the activation of oxidative metabolism. Pre-treatment of monocytes with IL-15 induced significantly higher levels of TNF-α, IL-10 and IL-15 production by cells challenged with the fungus. These results suggest a modulatory effect of IL-15 on pro and anti-inflammatory cytokine production, oxidative metabolism and fungicidal activity of monocytes during Pb18 infection.

Draft genome sequence of Bacillus thuringiensis 147, a Brazilian strain with high insecticidal activity

Bacillus thuringiensisis a ubiquitous Gram-positive and sporulating bacterium. Its crystals and secreted toxins are useful tools against larvae of diverse insect orders and, as a consequence, an alternative to recalcitrant chemical insecticides. We report here the draft genome sequence ofB. thuringiensis147, a strain isolated from Brazil and with high insecticidal activity. The assembled genome contained 6,167,994 bp and was distributed in seven replicons (a chromosome and 6 plasmids). We identified 12 coding regions, located in two plasmids, which encode insecticidal proteins.

Leprosy in children and adolescents under 15 years old in an urban centre in Brazil

This original study describes the intra-urban distribution of cases of leprosy in residents under 15 years old in Salvador, Bahia, Brazil; the study also identifies the environment in which Mycobacterium leprae is being transmitted. The cases were distributed by operational classification, clinical forms, type of contact and the addresses were geo-referenced by neighborhood. Between 2007 and 2011, were reported 145 cases of leprosy in target population living in Salvador, corresponding to detection rates of 6.21, 6.14, 5.58, 5.41 and 6.88/100,000 inhabitants, respectively. The spatial distribution of the disease was focal. Of the 157 neighborhoods of Salvador, 44 (28.6%) notified cases of leprosy and in 22 (50%) of these were detected more than 10 cases per 100,000 inhabitants. The infectious forms were found in 40% of cases. Over 90% of cases had been living in Salvador for more than five years. Overall, 52.6% reported having had contact with another infected individual inside the household and 25% in their social circle. In Salvador, M. leprae transmission is established. The situation is a major concern, since transmission is intense at an early age, indicating that this endemic disease is expanding and contacts extend beyond individual households.

The 15-minute family interview: a family health strategy tool

The 15-minute family interview is a condensed form of the Calgary Family Assessment and Intervention Models (CFAM and CFIM) that aims to contribute to the establishment of a therapeutic relationship between nurses and family and to implement interventions to promote health and suffering relief, even during brief interactions. This study investigated the experience of nurses from the Family Health Strategy (FHS) who used the 15-minute interview on postpartum home. The qualitative research was conducted in three stages: participants' training program, utilization of the 15-minute family interview by participants, and interviews with nurses. The data were collected through semi-structured interviews with eight nurses. The thematic analysis revealed two main themes: dealing with the challenge of a new practice and evaluating the assignment. This work shows that this tool can be used to deepen relationships between nurses and families in the Family Health Strategy.

Desenvolvimento pós-embrionário de Pattonella intermutans (Thomson) (Diptera: Sarcophagidae) em diferentes dietas

A proposta deste estudo foi de avaliar o desenvolvimento pós-embrionário de Pattonella intermutans (Thomson, 1869) em dietas artificiais preparadas com agar-agar. Dieta D1: leite em pó integral + fermento biológico; Dieta D2: leite em pó integral + fermento biológico + caseína; Dieta D3: leite em pó integral + ovo cru; Dieta D4: carne bovina moída (dieta controle). A carne bovina moída foi a dieta mais eficiente (peso larval de 195,63 mg e viabilidade de neolarva a adulto de 86,5%), quando comparada com as dietas artificiais. Os seguintes resultados foram obtidos para o grupo experimental: Dieta D3: 180,15 mg e 63,5%; Dieta D2: 141,07 mg e 61% e na Dieta D1: 147,98 mg e 51,5%.

A 15-year post evaluation of the fire effects on ant community in an area of Amazonian forest

Fire represents an important disturbance to ant communities in areas of fire regime. Otherwise, little is known about the effects of fire on ant communities in areas of non-fire regimes, such as in the Amazonian region. We evaluated the long-term effect of fire on ant species richness in a rain forest (Bacaba Plateau) burned 15-years ago and compare our data with the data of primary unburned forest. A total of 85 ant species distributed in 21 genera and 14 tribes were collected; among them, 72 and 44 species were found on the litter and vegetation, respectively. The fire damaged forest studied supports an intermediate richness of ants when compared to a primary unburned rain forest in the same region. A comparative analysis of ant species richness showed that the Bacaba Plateau presented a different ant fauna when compared with the primary unburned forests, suggesting that fire can alter ant species composition. Although, our results cannot be conclusive on the effects of fire on ant community, they represent a pioneer data on human induced fire in tropical rain forests.

Para onde caminham os Cieps? Uma análise após 15 anos

O trabalho descreve aspectos da realidade dos Centros Integrados de Educação Pública - Cieps -, da rede estadual do Rio de Janeiro, baseando-se em pesquisa, realizada em 2001, com 50 diretores. Estabelece comparações com a época em que essas escolas foram implantadas sob a forma de programa especial de governo, levando em conta o funcionamento em horário integral, as dificuldades de gestão, as atividades oferecidas, a quantidade de alunos por escola, a utilização e conservação dos espaços. Conclui que a variedade dos níveis de ensino abarcados e a convivência de diferentes regimes horários num mesmo estabelecimento demonstram a vocação ainda pouco definida de tais escolas. A opinião dos gestores sobre o trabalho desenvolvido nos Cieps que mantiveram o horário integral mostra que eles o consideram, muitas vezes, assistencialista, embora essa definição seja vaga e muito variada. Após mais de 15 anos de existência, a tendente municipalização do ensino fundamental e a pressão por vagas no ensino médio parecem ser os maiores entraves para a manutenção dessas escolas segundo seu projeto original.

Expressão dos genes nodC, nodW e nopP em Bradyrhizobium japonicum estirpe CPAC 15 avaliada por RT-qPCR

O objetivo deste trabalho foi avaliar a expressão, por RT-qPCR, dos genes de nodulação nodC e nodW e do gene nopP da estirpe CPAC 15, que provavelmente atuam na infecção das raízes da soja. Foram realizados dois experimentos. No primeiro, a expressão dos genes foi avaliada nas células após a incubação com genisteína por 15 min, 1, 4 e 8 horas. Os resultados revelaram que os três genes apresentaram maior expressão imediatamente após o contato com o indutor (15 min). No segundo experimento, a bactéria foi cultivada na presença de indutores (genisteína ou exsudatos de sementes de soja) por 48 horas. A expressão dos três genes foi maior na presença de genisteína, com valores de expressão para nodC, nodW e nopP superiores ao controle. Os resultados obtidos confirmam a funcionalidade dos três genes na estirpe CPAC 15, com ênfase para o nopP, cuja funcionalidade em Bradyrhizobium japonicum foi descrita pela primeira vez.