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SUMMARYAiming to further characterize the haemocyte subsets in Biomphalaria snails, we have performed a detailed flow cytometric analysis of whole haemolymph cellular components using a multiparametric dual colour labelling procedure. Ethidium bromide/acridine orange fluorescence features were used to first select viable haemocytes followed by flow cytometric morphometric analysis based on the laser scatter properties (forward scatter-FSC and side scatter-SSC). Our findings demonstrated that B. glabrata (BG-BH, highly susceptible to S. mansoni) and 2 strains of B. tenagophila (BT-CF, moderately susceptible and BT-Taim, resistant to S. mansoni) have 3 major circulating haemocyte subsets, referred to as small, medium and large haemocytes. The frequency of small haemocytes was higher in BG-BH, while medium haemocytes were the most abundant cell-type in both B. tenagophila strains. Schistosoma mansoni infection resulted in early reduction of large and medium circulating haemocytes followed by an increase of small haemocytes. Although parasite infection induced haemocyte alterations in all Biomphalaria strains, the response was particularly intense in BT-Taim, the parasite-resistant snail. Interestingly, the trematode infection induces changes in haemocytes with less granular rather than in those with more granular profile. The results indicated that, in B. tenagophila of Taim strain, circulating haemocytes, especially the medium and high subset with less granular profile, are very reactive cells upon S. mansoni infection, suggesting that this cell subset would participate in the early parasite destruction observed in this snail strain.

The objective of this study was to investigate the influence of processing parameters on the quality of the pinch-off welding of an ethylene-vinyl alcohol/polypropylene (EVOH/PP) six-layer bottle for tomato ketchup, evaluated in terms of its structure and properties imparted to the corresponding bottles. The pinch-off welding process was studied on coextruded blow moulded bottles by varying the mould temperature, the mould closing speed and the hold time according to a L9-Taguchi experiment design. It was observed that the mould closing speed is the more influential parameter, determining the layered structure at the pinch-off and the mechanical performance of the bottle. Better properties were obtained when the mould closing speed was set to the highest value allowed by the blow moulding equipment.

Lectins/carbohydrate binding can be involved in the Schistosoma mansoni recognition and activation of the Biomphalaria hemocytes. Therefore, expression of lectin ligands on Biomphalaria hemocytes would be associated with snail resistance against S. mansoni infection. To test this hypothesis, circulating hemocytes were isolated from B. glabrata BH (snail strain highy susceptible to S. mansoni), B. tenagophila Cabo Frio (moderate susceptibility), and B. tenagophila Taim (completely resistant strains), labelled with FITC conjugated lectins (ConA, PNA, SBA, and WGA) and analyzed under fluorescence microscopy. The results demonstrated that although lectin-labelled hemocytes were detected in hemolymph of all snail species tested, circulating hemocytes from both strains of B. tenagophila showed a larger number of lectin-labelled cells than B. glabrata. Moreover, most of circulating hemocytes of B. tenagophila were intensively labelled by lectins PNA-FITC and WGA-FITC, while in B. glabrata small hemocytes were labeled mainly by ConA. Upon S. mansoni infection, lectin-labelled hemocytes almost disappeared from the hemolymph of Taim and accumulated in B. glabrata BH. The role of lectins/carbohydrate binding in resistance of B. tengophila infection to S. mansoni is still not fully understood, but the data suggest that there may be a correlation to its presence with susceptibility or resistance to the parasite.

Concomitant infection with different parasites may be a helpful laboratorial strategy leading to the better understanding of the mechanisms used by the internal defense system (IDS) of Gastropoda to deal with helminth infection, such as Schistosoma mansoni. This work reports the effect of co-infection of Angiostrongylus vasorum and S. mansoni in hemocyte activity and in the outcome of infection. The simultaneous infection resulted in an increase of snail susceptibility to S. mansoni. In contrast, snails infected with both parasites, 15 days apart, did not show differences in the susceptibility compared to a single parasite infection. The increased susceptibility was measured by the significantly higher number of migrating sporocysts, higher percentage of snails shedding cercariae, higher number of cercariae shed and higher mortality in the experimental group that were simultaneously infected with A. vasorum and S. mansoni, when compared to snails infected only with S. mansoni. Snails simultaneously infected with A. vasorum and S. mansoni showed lower hemocyte activation during the first few days of infection, compared to activation induced only by A. vasorum infection. Between 5 and 15 days post-infection (dpi), granulocyte number and nitric oxide (NO) contents of simultaneously infected snails were lower than the S. mansoni-infected snails. Based on the results, we suggest that differences in the level of hemocyte response could explain the increased S. mansoni susceptibility observed in snails simultaneously infected with both parasites. However, when S. mansoni infection occurred after A. vasorum larvae are completely encapsulated, the response against S. mansoni was not altered, and therefore there were no differences in the susceptibility level.

The present work demonstrates that silica treatment represents a suitable in vivo method to evaluate the role of host phagocytic hemocytes in the mechanisms of resistance to parasitic infection. Silica inoculation into Biomphalaria tenagophila snail induced a significant reduction in the circulating hemolymph granulocytes in both strains tested (Taim and Cabo Frio). The granulocyte reduction was accompanied by a significant increase in the number of circulating dead cells. In B. tenagophila Cabo Frio, silica treatment enhanced snail susceptibility to Schistosoma mansoni, shortening the intramolluskan phase of the parasite and increasing the number of sporocysts and cercariae produced. In B. tenagophila Taim, the same treatment did not abrogate natural resistance to S. mansoni reported for this snail strain. These in vivo results demonstrate that macrophage-like granulocytes are involved in the mechanism of S. mansoni sporocyst destruction in Cabo Frio snails and suggest that another, different mechanism may be responsible to the natural resistance of B. tenagophila Taim.

Infrared spectroscopy coupled with adsorption of probe molecules such as CO and NO was used to investigate the surface adsorption properties of reduced Ru and Ru−Pt/NaY catalysts. CO adsorption at room temperature on the monometallic catalyst yielded three main bands at 2145, 2088, and 2031 cm-1, which were assigned to CO bonded on Ru-oxidized species in close interaction with the support, a carbonyl cluster compound with Ru atoms highly coordinated with CO molecules, and CO linearly bonded on Ru0 particles, respectively. They were not thermally stable and moved around between 1843 and 1881 cm-1 as the temperature was increased. This new band was attributed to CO bonded in a bridge form on two Ru0 atoms, the metal being in a different dispersion state when compared to the just-reduced catalyst. The same three bands were observed for CO adsorption on the bimetallic catalyst, in addition to the 2074 cm-1 band, which was attributed to CO linearly bonded to Pt0. As the temperature was raised, no CO was bonded...

Two woody species of Eriotheca (Bombacaceae) of the Central Brazilian Cerrados were submitted to RAPD analyses. Both species are bee pollinated and have a similar flower structure, but E. pubescens presents adventitious embryony and apomixis, while E. gracilipes is self-incompatible. The RAPD screening reflects these differences in breeding systems, with very low genetic variation in the apomictic species, while the sexual species presented much higher variability with no similar genotypes among the sampled trees. The results suggest that adventitious embryony in E. pubescens effectively results in clonal populations or population mosaics of clonal individuals. Since recent studies have indicated poly-embryony and possibly apomixis in a number of Cerrado woody species otherwise considered obligatorily allogamous, the RAPD results presented here indicate the technique will be a useful tool to detect clonal populations of apomictic origin among Cerrado woody species with mixed mating systems and will help to assess the importance of apomixis as a breeding system for the Cerrado flora.

High doses of gamma radiation (10 Krad) in Biomphalaria tenagophila snails (Taim strain), which have been found to be resistant to Schistosoma mansoni, were not sufficient to impair their resistance to the parasite. The number of hemocytes, as well as their phagocytic activity, were not affected by irradiation, thus showing resemblance with mammal macrophages, which are resistant to gamma irradiation also.

Human infection bySchistosoma mansoniaffects more than 100 million people worldwide, most often in populations of developing countries of Africa, Asia, and Latin America. The transmission ofS. mansoniin human populations depends on the presence of some species ofBiomphalariathat act as an intermediate host. The compatibility betweenS. mansoniand its intermediate host is influenced by behavioral, physiological, and genetical factors of the mollusc and the parasite. The susceptibility level of the mollusc has been attributed to the capacity of internal defense system (IDS)—hemocytes and soluble components of the hemolymph—to recognize and destroy the parasite, and this will be the center of interest of this paper. The schistosome-resistantBiomphalariacan be an alternative strategy for the control of schistosomiasis.

SUMMARY Biomphalaria tenagophila of Taim strain is able to completely destroy Schistosoma mansoni sporocyst few hours after parasite penetration, although the mechanism is still not well known. In this experimental work we show that passive transference of cell-free haemolymph, especially from B. tenagophila Taim, resulted in higher resistance of B. tenagophila Cabo Frio to S. mansoni infection. This effect was demonstrated in vivo, by the reduction in the infection rate, and the significantly lower production of sporocysts and cercariae of the parasite in snails treated with Taim cell-free haemolymph compared to CBSS-inoculated snails. The protective effect of Taim cell-free haemolymph was also observed during the in vitro interaction between haemocytes and sporocysts. In this system, addition of B. tenagophila cell-free haemolymph, especially from Taim strain, was responsible for significant increase in sporocyst mortality compared to B. glabrata cell-free haemolymph or culture medium. Moreover, the combination of Taim cell-free haemolymph and Cabo Frio haemocytes increased significantly the mortality of sporocysts. The results show that Taim cell-free haemolymph would act direct and indirectly on destruction of S. mansoni sporocysts. The results also suggest that cell-free haemolymph indirectly increases parasite recognition by the circulating granulocytes and it is species specific.

Biomphalaria tenagophila is very important for schistosomiasis transmission in Brazil. However its mechanisms of interaction with Schistosoma mansoni are still scantly studied. Since this snail displays strains highly susceptible or completely resistant to the parasite infection, the knowledge of that would be a useful tool to understand the mechanism of snail resistance. Particularly, the Taim strain consistently shows absolute resistance against the trematode, and this resistance is a dominant character. A multidisciplinary research group was created aiming at studying B. tenagophila/S. mansoni interaction. The possibility for applying the knowledge acquired to obtain a biological model for the control of S. mansoni transmission in endemic areas is discussed.

Objetivo: determinar a prevalencia dos agentes etiologicos das meningites bacterianas em servico de referencia, no atendimento de doencas infecciosas para o estado de Minas Gerais, e verificar a resposta ao tratamento utilizado.Metodos: estudo descritivo em que foram incluidas todas as criancas com diagnostico provavel de meningite, admitidas na instituicao no periodo de junho a novembro/99.Resultados: obteve-se 210 casos de meningite, sendo 111 casos de etiologia bacteriana (52,9%). Destes, 52 casos foram diagnosticos provaveis (por alteracao do liquor rotina) e 59 com diagnosticos de certeza (por cultura e/ou isolamento de antigeno). Os principais agentes isolados foram, em ordem decrescente, H. influenzae, N. meningitidis e S. pneumoniae. O tratamento inicial para a faixa etaria de tres meses a cinco anos foi ampicilina e cloranfenicol, sendo posteriormente restrito para penicilina em casos de meningococo e pneumococo, e para cloranfenicol nos casos de H. influenzae. A mudanca para antimicrobiano de maior espectro foi realizada com base em dados clinicos ou laboratoriais, nao havendo isolamento de microorganismo resistente.Conclusoes: o acompanhamento do perfil epidemiologico das meningites deve ser continuo, e cada servico deve se basear em dados locais para direcionar a terapia antimicrobiana. A monitorizacao continua dos agentes prevalentes em cada instituicao e de sua resistencia e fundamental para a escolha antimicrobiana, atuando com menor interferencia na colonizacao individual, sem contribuir para a crescente resistencia dos agentes responsaveis pelas infeccoes meningeas.

A case of pulmonary coccidioidomycosis from the rural zone of Bertolinia, PI, is reported. The patient, a farm worker, attributed his illness to the dust inhaled while digging a water well during the dry season of the year, some weeks before the onset of the clinical manifestations. The main symptoms of the disease were severe chest pain and moderate fever. The diagnosis was made histopathologically: tissue phase fungal organisms--immature spherules and spherules with endospores--were observed in histological sections of a lung fragment obtained by open chest biopsy. This is the twelfth autochthonous case of coccidioidomycosis found so far in Brazil. All of them involved native inhabitants of the semi-arid part of Northeastern Brazil. The hot and dry environment of the region seems to favor the development of C. immitis in the soil. Humans and animals probably acquire the infection by digging the soil, when they become exposed to the conidium-bearing dust raised by this activity.

A case of human disseminated pulmonary adiaspiromycosis is reported. The patient, from Goianésia, GO, was admitted to the Brasilia University Hospital, in November 1992, with wet cough, dyspnea and weight loss--manifestations that had appeared two months before. Prior to admission, he had been treated for a suspected miliary tuberculosis, because a chest roentgenogram had shown a diffuse reticulonodular infiltrate in both lungs. This therapy brought no improvement to the patient status. An open chest biopsy was then performed, and the microscopic examination of the lung tissue revealed the fungal nature of the disease. Ketoconazole, 400mg/day, was started and the patient discharged from the hospital. He was seen again two months later: the respiratory manifestations had disappeared and a new chest roentgenogram showed complete resolution of the pulmonary lesions. The usefulness of ketoconazole is, however, questioned, since, as there is no multiplication of the fungus in the host organism--adiaspiromycosis is believed to be, usually, a self-healing disease--the efficacy of this imidazole derivative against the agent in animal tissues remains to be confirmed.

The anesthetic effect of some water-soluble anesthesic or narcotic drugs currently used in mice was tested in molluscs of the Biomphalaria genus. Sodium thiopental was very toxic to the snails resulting in high rates of mortality in all the treatment schedules tested. Cetamine base, at concentration of 0.25 mg/ml of water, resulted in partial snail anesthesia (40% of snails were anesthetized) only after 20 h of exposition. The association of Cetamine base with Tiazine chloridrate did not improve the anesthesic effect, and higher concentrations of these drugs were toxic to the snails. Sodium pentobarbital at 0.4 mg/ml in water for 8 h was the best treatment schedule to anesthetize Biomphalaria snails. In this schedule, the snails were anesthetized without any toxic effect. The procedure provides a powerful tool for in vivo studies that demande a complete state of snail anesthesia.