Bothrops jararacussu snake venom decreases CD1d, CD83, and CD86 expression on bone marrow-derived dendritic cells.

This study was designed to characterize mice bone marrow (BM) and bone marrow-derived dendritic cells (BMDC) and to compare the surface markers expression and inflammatory cytokine liberation in response to LPS and Bothrops jararacussu venom (BjV) stimulation. Typical morphology was observed in BM and BMDCs from the 4th up to the 8th day of culture using recombinant mouse GM-CSF and IL-4. A high basal level of MHC-II, CD1d, CD83, CD11c, CD80, and low CD86 was expressed by BM cells. After stimulation with GM-CSF/IL-4 for BMDCs differentiation, the BM cells differentiated into BMDCs presented MHC-II, CD1d, CD83, CD11c, CD86, and CD80 expression on the 4th - 8th day accompanied with high levels of TNF-α liberated. The difference between the surface markers' expression was observed in this time course in which CD1d, CD11c, and CD80 remained in high levels of expression, while MHC-II and CD83 showed moderate expression during the differentiation period. Also, cytokines liberation was monitored over the period of the BMDCs culture, and on the 6th day, low levels of IL-6 and IL-1ß were found, while high levels of TNF-α on the 4th and 8th days, both of which contributed to the maturity of the BMDCs. Maturation of DCs with LPS showed significant upregulation of surface markers (MHC-II, CD1d, CD83, CD86, CD80) and pro-inflammatory cytokines (IL-1ß, IL-6, TNF-α) liberation. On the other hand, BjV induced a decrease in CD1d, CD11c, CD83, and CD86 expression in mature BMDCs which was not observed when LPS was used to stimulate BMDCs which probably induces impairment in T-cell activation.

Bothrops erythromelas venom and its action on isolated murine macrophages.

Snakebite is a universally neglected public health problem. It victimizes approximately 2.5 million people annually and kills around 125 thousand. In Brazil, the Bothrops genus is responsible for 87% of the envenoming. The species Bothrops erythromelas is endemic in the northeast region. Its venom induces local haemorrhage, coagulopathy, oedema, and necrosis and can lead to permanent disability or death. The in vitro effects of Bothrops erythromelas venom (BeV) on thioglycollate-elicited macrophages were investigated in this study. At non-cytotoxic concentrations, BeV did not interfere with the adhesion and detachment of thioglycollate-elicited macrophages. However, BeV induced lipid body formation and the activation of respiratory burst and TNF-α, but not IL-1ß and IL-6. The study aimed to extend the knowledge on the mechanism of action of BeV and its contribution toward a better characterisation of macrophage functionality under the action of Bothrops venom.

Action of two phospholipases A2 purified from Bothrops alternatus snake venom on macrophages.

The in vitro effects of BaltTX-I, a catalytically inactive Lys49 variant of phospholipase A2 (PLA2), and BaltTX-II, an Asp49 catalytically active PLA2 isolated from Bothrops alternatus snake venom, on thioglycollate-elicited macrophages (TG-macrophages) were investigated. At non-cytotoxic concentrations, the secretory PLA2 BaltTX-I but not BaltTX-II stimulated complement receptor-mediated phagocytosis. Pharmacological treatment of TG-macrophages with staurosporine, a protein kinase C (PKC) inhibitor, showed that this kinase is involved in the increase of serum-opsonized zymosan phagocytosis induced by BaltTX-I but not BaltTX-II secretory PLA2, suggesting that PKC may be involved in the stimulatory effect of this toxin in serum-opsonized zymosan phagocytosis. Moreover, BaltTX-I and -II induced superoxide production by TG-macrophages. This superoxide production stimulated by both PLA2s was abolished after treatment of cells with staurosporine, indicating that PKC is an important signaling pathway for the production of this radical. Our experiments showed that, at non-cytotoxic concentrations, BaltTX-I may upregulate phagocytosis via complement receptors, and that both toxins upregulated the respiratory burst in TG-macrophages.

Occupational hepatitis C seroconversions in a Brazilian hospital.

BACKGROUND: There are six known cases of occupational human immunodeficiency virus (HIV) seroconversion in Brazil. However, there are neither published cases of occupational hepatitis C virus (HCV) seroconversion nor systematic studies of blood and body fluid exposures (BBFE) that could estimate the risk of HCV or HIV occupational seroconversion in Brazil. AIMS: To describe the outcomes of BBFEs in a Brazilian hospital over 12 years and 2 months. METHODS: Statistical analysis of a computerized database of exposure events recorded on printed forms. Incidence rates (IR) were calculated as the number of BBFE per 100 full-time equivalent worker-years. RESULTS: There were 1457 BBFE, 87% being percutaneous and 561 (38%) recurring in health care workers (HCWs) who reported having previous exposures. The highest IRs occurred in laboratory technicians (9.7), medical students (9.5), cleaning staff (9.5) and nursing aids (9.2). The IR in temporary employees was 13.0. Two HCWs, a nursing aid and a surgeon, seroconverted to hepatitis C after HCV exposures involving 13 G catheter needles. The risk of acquiring a HCV infection was 2 in 38 percutaneous HCV exposures, i.e. 5% (95% CI: 0.89-16.3). There were no seroconversions to HIV despite 80 percutaneous HIV exposures. CONCLUSIONS: HCV has a higher potential for occupational transmission than HIV. Measures to reduce the risks of BBFE and occupational transmission of blood-borne viral infections should be improved in Brazil.

Effect of Bothrops alternatus snake venom on macrophage phagocytosis and superoxide production: participation of protein kinase C

Envenomations caused by different species of Bothrops snakes result in severe local tissue damage, hemorrhage, pain, myonecrosis, and inflammation with a significant leukocyte accumulation at the bite site. However, the activation state of leukocytes is still unclear. According to clinical cases and experimental work, the local effects observed in envenenomation by Bothrops alternatus are mainly the appearance of edema, hemorrhage, and necrosis. In this study we investigated the ability of Bothrops alternatus crude venom to induce macrophage activation. At 6 to 100 »g/mL, BaV is not toxic to thioglycollate-elicited macrophages; at 3 and 6 »g/mL, it did not interfere in macrophage adhesion or detachment. Moreover, at concentrations of 1.5, 3, and 6 »g/mL the venom induced an increase in phagocytosis via complement receptor one hour after incubation. Pharmacological treatment of thioglycollate-elicited macrophages with staurosporine, a protein kinase (PKC) inhibitor, abolished phagocytosis, suggesting that PKC may be involved in the increase of serum-opsonized zymosan phagocytosis induced by BaV. Moreover, BaV also induced the production of anion superoxide (O2-) by thioglycollate-elicited macrophages. This BaV stimulated superoxide production was abolished after treating the cells with staurosporine, indicating that PKC is an important signaling pathway for the production of this radical. Based on these results, we suggest that phagocytosis and reactive oxygen species are involved in the pathogenesis of local tissue damage characteristic of Bothrops spp. envenomations.

Human parvovirus B19 infection in HIV-positive patients.

Parvovirus B19 infects predominantly erythroid cells, leading to transient inhibition of erythropoiesis. Immunocompromised patients may be unable to produce neutralizing antibodies and may develop severe chronic anemia. Epidemiological studies done on Niterói population showed that B19 infection occurs periodically in late spring and summer. We report a study from 55 HIV infected patients attending an infectious diseases outpatient clinic in this city during a 5-month period in which B19 circulation was well documented. All patients were under anti-retroviral therapy. No anti-B19 IgM was found, but a high prevalence of IgG anti-B19 (91%) was observed. In six patients, B19 DNA was found by dot-blot hybridization techniques, but this was not confirmed by PCR. None of these 6 patients manifested anemia and only one had CD4 cell count below 200 x 10(7)/L. We conclude that persistent infection causing anemia is an infrequent finding in our HIV positive patients under drug therapy.

Human parvovirus B19 infection in HIV-positive patients

Parvovirus B19 infects predominantly erythroid cells, leading to transient inhibition of erythropoiesis. Immunocompromised patients may be unable to produce neutralizing antibodies and may develop severe chronic anemia. Epidemiological studies done on Niterói population showed that B19 infection occurs periodically in late spring and summer. We report a study from 55 HIV infected patients attending an infectious diseases outpatient clinic in this city during a 5-month period in which B19 circulation was well documented. All patients were under anti-retroviral therapy. No anti-B19 IgM was found, but a high prevalence of IgG anti-B19 (91%) was observed. In six patients, B19 DNA was found by dot-blot hybridization techniques, but this was not confirmed by PCR. None of these 6 patients manifested anemia and only one had CD4 cell count below 200 x 10(7)/L. We conclude that persistent infection causing anemia is an infrequent finding in our HIV positive patients under drug therapy.

O parvovírus B19 infecta predominantemente células eritróides, causando inibição transitória da eritropoiese. Pacientes imunocomprometidos podem ser incapazes de produzir anticorpos neutralizantes, evoluindo com grave anemia crônica. Estudos epidemiológicos da população de Niterói mostraram que a infecção ocorre periodicamente no final da primavera e no verão. Descrevem-se 55 pacientes infectados pelo HIV atendidos num ambulatório de doenças infecciosas nesta cidade num período de cinco meses, no qual a circulação do parvovírus B19 foi documentada. Todos os pacientes estavam sob terapia anti-retroviral. Não se encontrou IgM anti-B19, mas notou-se uma prevalência alta de IgG anti-B19 (91%). Em seis pacientes verificou-se a presença de DNA do B19 por hibridização em dot-blot, o que não se confirmou por PCR. Nenhum destes seis pacientes tinha anemia, e apenas um tinha células CD4 abaixo de 200 x 107/L. Conclui-se que infecção persistente causando anemia é um achado infreqüente em nossos pacientes HIV positivos sob terapia medicamentosa.

Aplastic crisis caused by parvovirus B19 in an adult patient with sickle-cell disease.

We describe a case of aplastic crisis caused by parvovirus B19 in an adult sickle-cell patient presenting with paleness, tiredness, fainting and dyspnea. The absence of reticulocytes lead to the diagnosis. Anti-B19 IgM and IgG were detected. Reticulocytopenia in patients with hereditary hemolytic anemia suggests B19 infection.

[The joint manifestations of exanthematous viroses]. / Manifestações articulares nas viroses exantemáticas.

The frequency of arthropathy was evaluated in 251 patients with clinical and serological diagnosis (specific IgM detection by enzyme immunoassay) of exanthematous disease. Arthropathy (arthralgia and/or arthritis) was more frequent in dengue fever (49%) and rubella (38.2%) cases than in human parvovirus (30%) and measles (28.1%) cases. Except for measles cases, joint complaints prevailed in adults (> or = 15 years of age) and this difference was significant. The higher frequency of arthropathy in adults was more evident in human parvovirus (75%), rubella (65%) and dengue fever (57.7%) cases than in measles cases (31%). Arthropathy was also more frequent in females for all rash diseases studied. The results of this study showed the high occurrence of joint complaints in the disease described here and the importance of laboratory confirmation for their differential diagnosis.

Influence of immunopreventable diseases and AIDS on the demand of an infectious diseases department in Rio de Janeiro State, Brazil, in the course of thirty years (1965-1994).

Brazil's nosologic profile has been sustaining profound modifications. Some occurred because of massive immunization campaigns and socioeconomic and demographic trends. Some yet were pure nosologic transitions, such as the emergence of AIDS. In this demand study it is described how these changes reflected on the 8,630 admission of an Infectious Diseases Department in Niterói, along a thirty year period. Brazilian rural endemic diseases were infrequent (3.45%). Men predominated (62%) all the time, in all age strata and in nearly all diseases. Children under fifteen predominated until 1983. There was, in the case of tetanus, a striking rise in age strata. Institutional mortality dropped from 31% in 1965 to 10% in 1984, but rose since then to 15% in 1994. However, if AIDS patients had not been computed, mortality would have kept descending till 8% at the end of the study period. The crescent unimportance of immunopreventable diseases paralleled with the growing prominence of AIDS. In less than a decade, AIDS ranked fifth among the most frequent diseases in the whole period of thirty years. As opposed to the immunopreventable diseases, neither meningitides nor pneumonia appear to be in decline. AIDS, by its exponential incidence, by its chronic character, and by the uncountable opportunistic infections it determines, imposes itself as a challenge for the coming years.

Itinerantes e itinerarios na busca da palavra

Pensar a sala como um espaco de nascimento de leitores/escritores e propor que nela se intalem a interacao e a palavra. Em questao, portanto, o silencio forcado e o repetir sem sentido que nao raro fazem parte de nossas classes de leitura e escrita. Ao se apagarem as vozes das criancas, se emudece tambem o professor, que na eloquencia disfarcada tenta esconder os sentimentos difusos e o cansaco de alguem que se perdeu no caminho. Na busca desse caminho, colaca-se para o professor o dialogo com o seu proprio texto, com o texto de seu aluno e com a prodecao cultural. Meditando o dialogo, a linguagem entendida como interlocucao, como lugar de acontecimento e de fruicao.

A construcao do papel do professor: uma experiencia com alfabetizadoras

Diante da precariedade da situacao educacional do pais, sobre que bases pode ser construida a identidade do papel de professor? Apoiando-se principalmente na teoria da acao comunicativa de habermas - onde a identidade se constroi na interacao com o outro, e onde o papel profissional é central a essa construcao - o artigo analisa depoimentos e relatos de um grupo de nove professoras alfabetizadoras em escolas publicas da Grande Sao Paulo, buscando responder aquela questao. A analise sugere a necessidade de que professores, transcendendo a esfera do privado, construam uma identidade na interacao com seus pares. Insiste-se, pois, na importancia da formacao de grupos para Interacao de professores, em escolas onde a direcao e a coordenacao pedagogica assumam, conjuntamente, um compromisso com um projeto educacional para sua clientela.

Papel e valor das interacoes sociais em sala de aula

Este artigo pretende discutir o conceito de interacoes sociais, de modo a clarificar seu papel e valor para a dinamica da sala de aula. Para tanto, dois aspectos serao discutidos: 1- a concepcao de Vygotsky, uma vez que esta se encontra na base de uma nova proposta teorica de relacoes entre as interacoes sociais e as construcoes cognitivas e 2- O conceito de interacoes sociais, no contexto escolar, a partir de uma reflexao sobre as pedagogias ditas ativas. Espera-se que tal discussao propicie alcancar uma nocao mais precisa a respeito das interacoes sociais que possuem valor formativo, as quais cabe ao professor incentivar e/ou promover.

Associacao da rifampicina a anfotericina B no tratamento da paracoccidioidomicose. Resultados em tres pacientes tratados. / Combination of rifampicin with amphotericin B in the treatment of paracoccidioidomycosis.Results in 3 treated patients

Trabalhos experimentais demonstraram que a anfotericina B, desorganizando funcionalmente a membrana celular fungica, permite a penetracao da rifampicina no citoplasma e sua consequente acao contra Histoplasma capsulatum, Blastomyces dermatitidis e Candida albicans. Com metade das doses habituais de anfotericina B associada a rifampicina conseguem-se melhores resultados do que com a anfotericina B isoladamente em doses plenas. Os Autores discutem as possiveis aplicacoes desta associacao no tratamento da paracoccidioidomicose e apresentam 3 casos desta micose em que a inatividade clinica e micologica so foi obtida apos o emprego combinado destas drogas