B-cell epitopes of antigenic proteins in Leishmania infantum: an in silico analysis.

Serodiagnosis of visceral leishmaniasis is often hindered by cross-reactions to other parasitic diseases. Identifying specific B-cell epitopes in proteins is therefore important for immunodiagnostics, as well as for disease control by vaccines. This study aimed to identify linear and conformational B-cell epitopes and to evaluate the secondary structure of antigen proteins in Leishmania infantum using in silico analysis. Linear epitopes were predicted using the Immune Epitope Database and Analysis Resource (IEDB), BepiPred and BcePred programs. The conformational B-cell epitopes were identified using the CBTOPE server. The combination of the predictions using IEDB, BepiPred and BcePred generated 148 linear epitopes from the calpain-like cysteine peptidase (CP), thiol-dependent reductase 1 (TDR1) and HSP70 proteins. In total, 164 conformational epitopes were predicted, mostly located in the linear epitope region. The predicted epitopes are located in α helix and random coil regions in the thiol-dependent reductase 1 and HSP70 proteins. New linear and conformational B-cell epitopes of L. infantum proteins were identified in silico, and the prediction using various programs ensures greater accuracy of the results, as suggested by confirmation of previously identified HSP70 epitopes.

New Species and New Records of Dexosarcophaga Townsend (Diptera: Sarcophagidae) from Brazil with a Key to Species of the Subgenus Bezzisca.

Dexosarcophaga tupinamba n. sp. is described based on male specimens from the Brazilian states of Pará and Maranhão; Dexosarcophaga bermudezi Silva & Mello-Patiu is newly recorded from Pará and South America; and Dexosarcophaga avispaensis Mello is newly recorded from Pará (new to Brazil). The Brazilian species Dexosarcophaga limitata (Lopes) and Dexosarcophaga pusilla (Lopes) are both recorded from Pará, which are new records from the Brazilian Amazon, Dexosarcophaga aurifacies (Lopes) is newly recorded from the state of Alagoas and Dexosarcophaga carvalhoi (Lopes) is newly recorded from the states of Mato Grosso, Maranhão, and Pará. A key to the identification of males of the subgenus Bezzisca is provided.

Composition, abundance and richness of sarcophagidae (Diptera: oestroidea) in forests and forest gaps with different vegetation cover.

This study was carried out in the Base Operacional Geólogo Pedro de Moura (BOGPM) in the Urucu River Basin, Coari, state of Amazonas, Brazil, during April, June, and October 2007, in 16 areas, 4 in primary forests (environment MT) and 12 in gaps (environments C1, C2, and C3) at different stages of vegetation recovery, with different plant cover height. We collected 3,547 specimens of flesh flies. The 3,525 individuals identified to species level included 10 genera, 6 subgenera, and 23 species. Sarcodexia lambens (Wiedemann) (47.1%) and Peckia (Peckia) chrysostoma (Wiedemann) (19.1%) were the most abundant species. The abundance patterns and estimated richness differed between the environments, and were separated in two groups, one of the gaps (C1, C2, and C3) and another of forests (MT). Both abundance and estimated richness were higher in the gaps (C1, C2, and C3) than in the forest (MT).

Proteolytic action of Bothrops jararaca venom upon its own constituents.

Many of the components of Bothrops jararaca venom are proteolytic enzymes. In the present work, we investigated the proteolytic action of B. jararaca venom upon its own constituents. Crude venom was reconstituted and incubated at pH 5.0 or 8.5 for up to 48h at room temperature. Aliquots taken at 0, 24 and 48h of incubation were then tested for proteolytic activity and several biological activities, as well as electrophoretic migration pattern and antibody recognition. Rate of hydrolysis of azocasein by venom samples was not changed by the incubation, but hemagglutinating activity decreased by 93% after 24h of incubation at pH 8.5, with no detectable changes at pH 5.0. Incubation of venom samples caused a progressive increase in phospholipase A(2) and procoagulant activities that was more evident in samples incubated at pH 5.0. The electrophoretic migration pattern showed no significant change for venom samples incubated at pH 5.0, whereas in samples incubated at pH 8.5 bands in the region between 66 and 45kDa gradually disappeared. The addition of a mixture of protease inhibitors (EDTA, PMSF, PPACK and benzamidine) effectively protected against venom degradation at pH 8.5. The cocktail of inhibitors also reduced the changes in phospholipase A(2) activity found in venom samples incubated at pH 5.0. Recognition of venom samples by polyclonal antibodies raised against crude venom was progressively lost during incubation at both pH 5.0 and 8.5; again the addition of protease inhibitors protected against loss of antibody recognition. We conclude that prolonged manipulation of B. jararaca venom at an acidic or alkaline pH can produce significant changes in its biological properties.

Platelets and hypersensitivity.

Platelets are anucleated blood cells not exclusively committed to hemostasis. They participate in inflammation, tissue repair, the immune response and hypersensitivity. In this review, the role of platelets in hypersensitivity is summarized. In order to understand the profound implications of these cells, the authors introduce the involvement of platelets in inflammation and immune reactions. Both the pathophysiology and the biology of the interaction of platelets with other cells are then summarized. These interactions justify the actual knowledge about the possibilities for the involvement of platelets in clinical states of hypersensitivity. Furthermore, the participation of platelets in allergy is supported by biological and clinical evidence, including in vitro studies of platelet activity in hypersensitivity states, the demonstration of platelet killing and the response to parasite contact, as well as animal studies in which the response to immune aggression is dependent on platelet reactivity. However, the need for more complete and developed clinical studies is clearly stressed, as several therapeutic approaches can already be proposed for a better control of these processes.

Platelet reactivity to "in vitro" allergen challenge in asthmatic patients.

Platelet involvement in inflammation and allergic states is now well documented. In fact, it has been suggested that platelets can be triggered by either activated cells as monocytes and macrophages or by allergen itself. This latter possibility is still a matter of controversy. In this study we analysed platelet "in vitro" response to allergen, by optical aggregation technique, in 25 asthmatic patients, being 20 atopic and 5 non atopic patients. Platelet aggregation response to epinephrine, ADP, collagen and arachidonic acid was studied in all patients. In addition, allergen was added to platelet rich plasma and platelet reactivity was recorded both before and after stimulations with collagen. Platelet aggregation studies confirmed and abnormality of ADP induced platelet aggregation, that exhibited great variability among patients. In most cases this defect was the only one found in asthmatic patients and it should be further analysed. Results also showed a nonspecific response to allergen when dissolved in glycerol. This was due to glycerol rather than to allergen, since lyophilized allergen did not affect platelets, and glycerol added to platelet rich plasma induced the same type of curve. So, allergen by itself does not imply platelet aggregation. Experiments with IgE did not provoke either platelet agglutination or platelet aggregation. Furthermore, previous incubation with allergen immediately before collagen induced aggregation did not significantly change platelet response. This study allows the conclusion that platelet reactivity to allergen contact must be an expression of multicellular cooperation rather than a direct effect on platelet IgE receptors stimulation.

T cells, macrophages and platelets in asthma.

The role of T cells, macrophages and platelets in asthma is discussed. Peripheric T cell populations are normal as well in atopic as in non atopic. Macrophages can release histamine releasing factors and PAF in presence of allergens. Platelets stimulated by contact with allergens or PAF decreased the aggregation pattern induced by common inducers. These data show that different cells can play a role in the inflammatory process in asthma.

Cellular interactions in asthma.

Immediate phase of asthma is induced by mast cells. Late phase asthmatic response is related to other cells such as, macrophages, lymphocytes, eosinophils, and could pass to chronicity and is usually associated with bronchial hyperreactivity. Pathological or functional studies of the different cells involved, could be done in peripheral blood, broncho-alveolar lavage, bronchial biopsies or nasal lavages.

Platelet aggregation in allergic reactions.

The platelet aggregation in the presence of 4 aggregation inducers was studied in 63 allergic patients, consisting of atopic and non-atopic asthmatics and aspirin-sensitive subjects, before and after inhalation tests or in vitro incubation with allergen. Basal platelet aggregation was decreased in 43% of the atopic patients for adrenaline and also in a smaller percentage for other agonists. A decreased aggregation was also observed in 3 out of 6 nonatopic patients and in aspirin-sensitive patients. In vivo or in vitro provocation tests decreased aggregation in some additional patients. These results point out to a compromise of platelets in allergic mechanisms.

Tratamento cirurgico da tetralogia de Fallot com agenesia da arteria pulmonar esquerda. Relato de dois casos. / Surgical treatment of tetralogy of Fallot with left pulmonary artery agenesia. Report of 2 cases

Dois pacientes com tetralogia de Fallot (TF) e agenesia da arteria pulmonar esquerda(AAPE) foram tratados cirurgicamente, com bons resultados. Como no ato cirurgico o anel pulmonar era inadequado, a via de saida do ventriculo direito (VSVD) foi ampliada com um "patch" de dacron. Uma revisao da literatura demonstrou que os resultados cirurgicos desta rara anomalia nao eram bons ate que, em duas experiencias recentes, a competencia valvular pulmonar foi mantida com o uso de protese biologica na VSVD. Apesar da incompetencia valvular pulmonar, bem tolerada na correcao classica da TF, os nossos pacientes evoluiram bem. Persiste a controversia sobre qual o melhor tratamento da VSVD na TF com AAPE