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.

Distinction among the puparia of three blowfly species (Diptera: Calliphoridae) frequently found on unburied corpses

Calliphorid larvae are important in the decomposition of carrion. Since these larvae are present in the primary stages of succession on carcasses, they may be important indicators of death time and the movement of corpses in homicide investigations. In this study we examined the morphological differences among puparia of Chrysomya megacephala, C. putoria and Cochliomyia macellaria. Puparia of the three species (N=30, each) were obtained from the F2 generation bred in culture medium at 25° C, and 60% relative humidity on a 12 h photoperiod. The interspecific differences found were related to the conspicuousness of six tubercles located in the region near the posterior spiracles and to the distance between the two peritrema involving the spiracles. The latter were (mean ± SD) 15.2 ± 3.1 mum for C. megacephala, 18.8 ± 2.8 mum for C. putoria and 16.5 ± 3.5 mum for C. macellaria. The results of the present study may be useful in forensic entomology.

Epidemiological and Serological Aspects in Canine Toxoplasmosis in Animals with Nervous Symptoms

The presence of anti-Toxoplasma gondii IgM and IgG antibodies was studied in samples of blood serum taken from eighty dogs with nervous symptoms at the Serviço de Enfermidades Infecciosas dos Animais, Faculdade de Medicina Veterinária e Zootecnia, Unesp, Botucatu, São Paulo, Brazil. The frequency of IgG titers were 16 (13.7%), 64 (13.7%), and 256 (5%), and for IgM titers were 16 (7.5%), 64 (15%), and 256 (8.7%). Positive reactions were more frequent in the older animals, males, from a rural environment, in constant contact with small animals, principally birds and rodents. There was a higher frequency of a positive reaction in dogs fed with kitchen food, especially in those fed with raw ingredients. The most common neurological pictures were alterations in consciousness, in movement, and in the hand-cart test. The percentage of reagents with specific IgM antibodies was high, indicating active infections, but the possibility of co-infection with the distemper virus can not be discarded, and this may be a predisposing factor for toxoplasmosis infection, once the distemper virus has a potent immunosupressive action.

Intestinal Coccidia (Apicomplexa: Eimeriidae) of Brazilian Lizards. Eimeria carmelinoi n.sp., from Kentropyx calcarata and Acroeimeria paraensis n.sp. from Cnemidophorus lemniscatus lemniscatus (Lacertilia: Teiidae)

Eimeria carmelinoi n.sp., is described in the teiid lizard Kentropyx calcarata Spix, 1825 from north Brazil. Oocysts subspherical to spherical, averaging 21.25 x 20.15 µm. Oocyst wall smooth, colourless and devoid of striae or micropyle. No polar body or conspicuous oocystic residuum, but frequently a small number of fine granules in Brownian movement. Sporocysts, averaging 10.1 x 9 µm, are without a Stieda body. Endogenous stages characteristic of the genus: intra-cytoplasmic, within the epithelial cells of the ileum and above the host cell nucleus. A re-description is given of a parasite previously described as Eimeria cnemidophori, in the teiid lizard Cnemidophorus lemniscatus lemniscatus. A study of the endogenous stages in the ileum necessitates renaming this coccidian as Acroeimeria cnemidophori (Carini, 1941) nov.comb., and suggests that Acroeimeria pintoi Lainson & Paperna, 1999 in the teiid Ameiva ameiva is a synonym of A. cnemidophori. A further intestinal coccidian, Acroeimeria paraensis n.sp. is described in C. l. lemniscatus, frequently as a mixed infection with A. cnemidophori. Mature oocysts, averaging 24.4 x 21.8 µm, have a single-layered, smooth, colourless wall with no micropyle or striae. No polar body, but the frequent presence of a small number of fine granules exhibiting Brownian movements. Sporocysts 9 x 8, without a Stieda body. Endogenous stages epicytoplasmic, characteristic of the genus, in the upper ileum. The importance of a study of the endogenous stages of eimeriid coccidia is discussed.

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.

The role of population movement in the epidemiology and control of schistosomiasis in Brazil: a preliminary typology of population movement

This paper examines recent developments in migration studies. It reviews literature related to the potential role of internal population movement in the occurrence of schistosomiasis in Brazil and modifies Prothero's typology of population movement for use in Brazil. This modified classification system may contribute to a better understanding of schistosome transmission as well as improved research and control programs. The results of this study indicate that population movement in Brazil primarily involves economically-motivated rural-urban and interregional movement. However, several movement patterns have become increasingly important in recent years as a result of changing socioeconomic and urbanisation dynamics. These patterns include urban-urban, intracity and urban-rural movement as well as the movement of environmental refugees and tourists. Little is known about the epidemiological significance of these patterns. This paper also highlights the role of social networks in the decision to migrate and to settle. Prothero's classic population movement typology categorises movement as either one-way migrations or circulations and examines them along spatial and temporal scales. However, the typology must be modified as epidemiological information about new patterns becomes available. This paper identifies areas that require further research and offers recommendations that can improve the measurement and spatial analysis of the relationship between population movement and schistosomiasis.

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.

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.

Sharing competences in strategic alliances: a case study of the Cosan and Shell biofuel venture

In a competitive world, the way a firm establishes its organizational arrangements may determine the enhancement of its core competences and the possibility of reaching new markets. Firms that find their skills to be applicable in just one type of market encounter constraints in expanding their markets, and through alliances may find a competitive form of value capture. Hybrid forms of organization appear primarily as an alternative to capturing value and managing joint assets when the market and hierarchy modes do not present any yields for the firm's competitiveness. As a result, this form may present other challenging issues, such as the allocation of rights and principal-agent problems. The biofuel market has presented a strong pattern of changes over the last 10 years. New intra-firm arrangements have appeared as a path to participate or survive among global competition. Given the need for capital to achieve better results, there has been a consistent movement of mergers and acquisitions in the Biofuel sector, especially since the 2008 financial crisis. In 2011 there were five major groups in Brazil with a grinding capacity of more than 15 million tons per year: Raízen (joint venture formed by Cosan and Shell), Louis Dreyfus, Tereos Petrobras, ETH, and Bunge. Major oil companies have implemented the strategy of diversification as a hedge against the rising cost of oil. Using the alliance of Cosan and Shell in the Brazilian biofuel market as a case study, this paper analyses the governance mode and challenging issues raised by strategic alliances when firms aim to reach new markets through the sharing of core competences with local firms. The article is based on documentary research and interviews with Cosan's Investor Relations staff, and examines the main questions involving hybrid forms through the lens of the Transaction Cost Economics (TCE), Agency Theory, Resource Based View (RBV), and dynamic capabilities theoretical approaches. One focal point is knowledge "appropriability" and the specific assets originated by the joint venture. Once the alliance is formed, it is expected that competences will be shared and new capabilities will expand the limits of the firm. In the case studied, Cosan and Shell shared a number of strategic assets related to their competences. Raízen was formed with economizing incentives, as well to continue marshalling internal resources to enhance the company's presence in the world energy sector. Therefore, some challenges might be related to the control and monitoring agents' behavior, considering the two-part organism formed by distinctive organizational culture, tacit knowledge, and long-term incentives. The case study analyzed illustrates the hybrid arrangement as a middle form for organizing the transaction: neither in the market nor in the hierarchy mode, but rather a more flexible commitment agreement with a strategic central authority. The corporate governance devices are also a challenge, since the alignment between the parent companies in the joint ventures is far more complex. These characteristics have led to an organism with bilateral dependence, offering favorable conditions for developing dynamic capabilities. However, these conditions might rely on the partners' long-term interest in the joint venture.

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.

Surface swimming behavior of the curculionid Ochetina uniformis Pascoe (Erirhininae, Stenopelmini) and Ludovix fasciatus (Gyllenhal) (Curculioninae, Erodiscini)

The swimming behavior exhibited by specimens of L. fasciatus and O. uniformis was analyzed frame-by-frame with video observation recorded with a digital camera, attached to a stereomicroscope. Adults of O. uniformis, an aquatic insect, swim with all three pairs of legs. During the process of swimming the majority of the abdomen and rostrum remain submerged, part of the fore and hind tibiae remain above the surface, while the mid tibiae remain submerged. The mesothoracic legs, during the power-stroke stage, provide the greatest thrust while the metathoracic legs provide the least forward propulsion. The prothoracic legs, extended forward, help to direct the swimming. The semi-aquatic specie L. fasciatus shows the same swimming style as O. uniformis, that is, with movement of all the three pairs of legs; the mesothoracic legs are responsible for the main propulsion. The insect body remains on the water surface during the process of swimming, while the legs remain submerged. Both species complete a swimming cycle in 0.33 and 0.32 seconds, respectively, with an average speed of 1.38 cm/s and a maximum and minimum swimming duration time of 11.15 and 5.05 minutes, respectively, for L. fasciatus. The swimming behavior exhibited by O. uniformis and L. fasciatus corresponds to the style known as a breast strokelike maneuver. This is the first record of this kind of swimming for both species here observed and increases to seven the number of genera of Curculionidae exhibiting this behavior.

Adaptations of two specialist herbivores to movement on the hairy leaf surface of their host, Solanum guaraniticum Hassl (Solanaceae)

Plant trichomes can difficult the attachment and movement of small insects. Here, we examine the hypothesis that the success on the use of densely haired hosts by two cassidine species is determined by differential morphology and behavior. Larvae of Gratiana graminea (Klug, 1829) and Gratiana conformis (Boheman, 1854) move on the leaf surface of their host, Solanum guaraniticum Hassl by anchoring their tarsungulus on the trichome rays or by inserting the tarsungulus tip directly into epidermis. This kind of movement is only possible due to a similar tarsungulus shape among the species. Tarsungulus growth pattern is also similar between species, being relatively small on the posterior aperture, matching the diameter of the host plant trichome rays. The tarsungulus shape associated with differences on ontogenetic growth and attachment pattern allow these two Cassidinae larvae to efficiently move on the pubescent leaf surface of their host.

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.