Showing papers by "Oswaldo Cruz Foundation published in 1986"

An outbreak of dengue virus at Rio de Janeiro - 1986

Abstract: Dengue virus type 1 has been isolated in Aedes albopictus cell strain, from sera of patients living in the Nova Iguacu county, by Rio de Janeiro. The clinical picture was characterized by fever, headache, retrobulbar pain, backache, pains in the muscles and the joints and prostration. Studies in paired sera confirmed the presence of recent infection by dengue virus type 1. The outbreak reached adjacent areas, including Rio de Janeiro city (May, 1986).

Potential vectors of malaria and their different susceptibility to Plasmodium falciparum and Plasmodium vivax in northern Brazil identified by immunoassay.

Abstract: During the period from May 1983 to July 1985 we conducted an epidemiological study to determine potential vectors of malaria in 6 districts in the state of Para in northern Brazil. The examination of random human blood smears, prepared at the time of mosquito capture, indicated overall human infection rates of 16.7% and 10.9% for Plasmodium falciparum and P. vivax, respectively. Two immunoassays, the immunoradiometric assay (IRMA) and the enzyme-linked immunosorbent assay (ELISA), based on the use of species-specific antisporozoite monoclonal antibodies, were used to analyze a total of 9,040 field-collected Anopheles mosquitoes for plasmodial infection. P. falciparum sporozoite antigen was detected in A. darlingi at rates varying from 2.7% to 4.2%, and in small numbers of A. oswaldoi collected in 1 of the districts. In contrast, sporozoite antigen of P. vivax was found in A. darlingi, A. triannulatus, A. nuneztovari, and A. albitarsis at rates ranging from 0.9% to 12.0%. By dissection, sporozoites were found in the salivary glands of these same 4 species at rates ranging from 0.8% to 2.2%. The latter 3 species had not previously been implicated as malaria vectors of any significance in northern Brazil.

Participação do cão no ciclo de transmissão da Leishmaniose tegumentar no município de Viana, Estado do Espírito Santo, Brasil

Abstract: In an endemic area of cutaneous leishmaniasis in the viana municipality, Espirito Santo state, an investigation was performed on natural hosts of leishmania among domestic animals, trying to correlate the presence of infected animals with the occurrence of the disease in humans. Within a three weeks period 186 dogs were examined and 32 (17,2%) were found infected.Eleven new cases of cutaneous leishmaniasis were recorded during one year, among people living in the endemic area. A close relationship was between the presence of infected dogs and the occurrence of human leishmaniasis. In the area studied, the disease seems to behave as a zoonosis maintained by domestic dogs.

Isolation of Leishmania mexicana amazonensis from the bone marrow in a case of American visceral leishmaniasis.

Abstract: The first documented human case of visceral leishmaniasis caused by L mexicana amazonensis is reported Leishmania were isolated from bone marrow aspirate material from a typical visceral leishmaniasis patient Further characterization by isoenzyme electrophoresis and by a panel of species- and subspecies-specific monoclonal antibodies established its classification as L m amazonensis

Alguns aspectos da ecologia dos mosquitos (Diptera, Culicidae) de uma área de planície (granjas Calábria), em Jacarepaguá, Rio de Janeiro: V. Criadouros

Abstract: Results are presented of observations on the breeding places of mosquitoes, carried out in a coastal lowland farm - Granjas Calabria, in JAcarepagua, city of Rio de Janeiro, Brazil The majority of species preferred breeding places on the ground, chiefly the natural ones, but also developed in those originated from human activities Cx saltanensis and the species belonging to the Aedini tribe, such as Ae scapularis, Ae taeniorhynchus, Ps ciliata, Ps confinnis and Ps Pseudomelanota were more abundant in temporary breeding places, while Ma titillans, Cx amazonensis, Cx chidesteri, Cx bidens, Cx declarator, cx nigipalpus and Cx plectoporpe occurred usually in the permanent ones Some species were collected in natural recipients: Cx ocellatus, the Cx (Microculex), Ph davisi, Ph deanei and Wy forcipenis, in bromeliads, Ae terrens, Cx imitator and Cx gairus, in tree-holes; and Wy leucostigma, in the submerged Typha dominguensis leaf axils Cx gairus was found for the first time breeding in artificial containers, which were also preferred by Cx corniger, Cx quinquefasciatus and Li durhaml

Cellular immune responses of chagasic patients to antigens derived from different Trypanosoma cruzi strains and clones.

Abstract: The reactivity of peripheral blood mononuclear cells (PBMN) from 62 chagasic patients to antigens prepared with different Trypanosoma cruzi strains and clones belonging to different zymodemes was evaluated by the incorporation of 3H-thymidine into DNA. Standardization of experimental conditions was carried out by establishing the proper antigen concentration (15–20 µg protein), the adequate period of time (5–6 days) and the best cell concentration (300,000/well). Individual analysis of 62 patients showed 2 distinct patterns of cellular response. One group of patients (32%) had low cellular responses to all antigens tested while the remaining patients had high response to at least 1 of the antigens. No relationship of the immune responsiveness to the patients' clinical forms could be established. In addition, the PBMN response to different strain and clone antigens was not statistically significant. Thus, it appears that the cellular response induced by any particular clone or strain represents an expression of the stimulation of their common antigenic make-up.

IgE antibody and resistance to infection II. Effect of IgE suppression on the early and late skin reaction and resistance of rats to Schistosoma mansoni infection

Abstract: Most helminth parasites induce a strong IgE antibody and elevated eosinophil response in their mammalian hosts and a number of in vitro studies have suggested that IgE, possibly in association with eosinophils, may be an essential element of the host protective immunity against helminth infections. To assess the role of IgE in protective immunity, we examined the effect of suppressing the IgE antibody response on rat immunity to Schistosoma mansoni. Suppression was achieved in neonates by injections of rabbit anti-epsilon chain gamma-globulins, control rats received injections of unspecific gamma-globulins. IgE suppression caused a marked reduction of the inflammatory reaction that developed in the skin of immune rats at the site of a cercarial challenge: the early (30 to 60 min) wheal and flare reaction was abolished, and the late cutaneous reaction (6 to 18 h) associated with intense pruritus, edema and local eosinophilia was greatly reduced. This shows that IgE was critical to the recruitment of effector cells and molecules in the skin during the first 24 h following parasite invasion. Worms were recovered 18 to 30 days after a primary infection and 18 days after a challenge infection from IgE-suppressed and control rats. IgE-suppressed rats cured a first infection as rapidly as the control rats; however, they were two to three times less efficient than the controls at eliminating a second or a third challenge. These observations demonstrate that IgE antibodies are essential for the full development of rat acquired protective immunity against Schistosoma mansoni.

Cutaneous leishmaniasis is frequent in equines from an endemic area in Rio de Janeiro, Brazil.

Abstract: In an endemic area of cutaneous leishmaniasis in Rio de Janeiro State where a mule had been found infected, a systematic search among equines was performed, resulting in the detection of Leishmania parasites in skin lesions of 30.8% of the animals, which included horses and mules. The eventual role of equines in the epidemiology of the human disease is being investigated.

Active cutaneous leishmaniasis in Brazil, induced by Leishmania donovani chagasi

Abstract: L.d. chagasi was isolated from active cutaneous leishmaniasis in both human and canine infections in an endemic area in Rio de Janeiro, Brazil. Both isolates were identified by molecular and immunological characterization of the parasite using three different methods: electrophoretic mobility of isoenzymes; restriction endonuclease fragment analysis of kDNA and serodeme analysis using monoclonal antibodies. This seems to be the first well documented case in the New World of a "viscerotropic" Leishmania inducing a case of cutaneous leishmaniasis. This observation emphasizes that the diagnosis of the etiologic agent of human or canine visceral leishmaniasis based solely upon clinical and epidemiological critwria may lead to erroneous conclusions.

Interaction ofTrypanosoma cruzi with macrophages: effect of previous incubation of the parasites or the host cells with lectins

Abstract: The effect of incubation with lectins of the macrophages or two evolutive stages ofTrypanosoma cruzi (noninfective epimastigotes and infective trypomastigotes) on the ingestion of the parasites by mouse peritoneal macrophages was studied. Lectins which bind to residues of mannose (Lens culinaris, LCA),n-acetyl-d-glucosamine orn-acetylneur-aminic acid (Triticum vulgaris, WGA), β-d-galactose (Ricinus communis, RCA),n-acetyl-d-galactosamine (Phaseolus vulgaris, PHA;Dolichos biflorus, DBA; andWistaria floribunda, WFA), fucose (Lotus tetragonolobus, LTA), andn-acetylneuraminic acid (Limulus polyphemus, LPA) were used. By lectin blockage we concluded that, α-d-mannose-like, β-d-galactose andn-acetyl-d-galactosamine (PHA, reagent) residues, located on the macrophage's surface are required for both epi- and trypomastigote uptake, whilen-acetylneuraminic acid and fucose residues, impede trypomastigote ingestion but do not interfere with epimastigote interiorization. Macrophages'n-acetyl-d-glucosamine residues are required for epimastigote uptake. On the other hand, from theT. cruzi surface, mannose residues prevent ingestion of epi- and trypomastigotes. Galactose residues participate in endocytosis of trypomastigotes, but hinder epimastigote interiorization. Exposedn-acetyl-d-glucosamine residues are required for uptake of the two evolutive forms.n-acetylneuraminic acid residues on the trypomastigote membrane prevent their endocytosis by macrophages. These results together with those reported previously showing the effect of monosaccharides on theT. cruzi-macrophage interaction, indicate that (a) sugar residues located on the parasite and on macrophage surface play some role in the process of recognition ofT. cruzi, (b) different macrophage carbohydrate-containing receptors are involved in the recognition of epimastigotes and trypomastigotes forms ofT. cruzi, (c)n-acetylneuraminic acid residues located on the surface of trypomastigotes or macrophages impede the interaction of the parasite with these host cells, and suggest that (d) sugar-binding proteins located on the macrophage surface participate in the recognition of β-d-galactose andn-acetyl-d-galactosamine residues located on the surface of trypomastigotes and exposed after blockage or splitting off ofn-acetylneuraminic acid residues. Some lectins which bind to macrophages and block the ingestion of parasites did not interfere with their adhesion.

Ectoparasitos de roedores e marsupiais no ambiente silvestre de Ilha Grande, Estado do Rio de Janeiro, Brasil

Abstract: Ectoparasites collected from wild mammals of Ilha Grande, state of Rio de Janeiro, Brazil, are listed. The most frequent species of mammal was Proechimys dimidiatus (Gunther, 1877); Gigantolaelaps oudemansi Fonseca, 1939 and Polygenis lakoi Guimaraes, 1948 were the predominant species of acari and fleas, respectively.

The interaction of myotropic and macrophagotropic strains of Trypanosoma cruzi with myoblasts and fibers of skeletal muscle.

Abstract: The process of interaction of bloodstream trypomastigotes from the myotropic CL and Colombiana strains and the macrophagotropic Y strain ofTrypanosoma cruzi with mouse myoblasts and myotubes was analysed. After 24 h of parasite-host cell interaction, parasites from the CL and Colombiana strains appeared to be more infective to myoblasts than those from the Y strain. Parasites from the Colombiana strain were more infective for myotubes than those from the Y strain, while those from the CL strain showed very a low ability to infect the cells. For all strains the infectivity was low for short periods of interaction, increasing with time. Myoblasts infected with parasites from the Y strain fused with other infected and uninfected cells to form myotubes. However, the process of fusion was blocked when the myoblasts were infected with parasites from the CL and Colombiana strains. These data indicate a different behavior of muscle cells when in contact with myotropic or non-myotropic strains ofT. cruzi.

An outbreak of Chagas' disease in southwestern Bahia, Brazil.

Abstract: An outbreak of 20 cases of acute Chagas' disease followed the movement of Triatoma infestans into the county of Riacho de Santana, Bahia, Brazil. The outbreak was unusual in that the majority of cases occurred in adults. Vector control measures were implemented. Three years after the outbreak, a rural community was examined to determine the extent of human infection and disease due to Trypanosoma cruzi. Ninety of 440 residents (20.5%) had serologic evidence of infection, but rates of electrocardiographic (EKG) abnormalities were low. Comparison of age-specific rates of seropositivity and EKG abnormalities with rates from areas with endemic Chagas' disease supported the hypothesis of a recent epidemic. Control measures appear to have interrupted transmission in the region.

Epidemiologia descritiva do alcoolismo em grupos populacionais do Brasil

Abstract: A partir de estudos nacionais, publicados entre 1943 e 1985, que fornecem dados sobre o alcoolismo, foram utilizados no presente artigo, especialmente aqueles que tem algum cunho epidemiologico. Seus dados foram reanalisados e utilizados apenas em seus valores absolutos; recalcularam-se as taxas e porcentagens, aglutinando-as em resultados que tivessem as mesmas caracteristicas. Pelos dados analisados, encontramos maior predominância de alcoolismo em adultos jovens, concentrando-se entre 20 e 49 anos de idade, na razao de 10 homens para 1 mulher. No que diz respeito a taxas de prevalencia, verificou-se que em tres estudos em populacoes acima de 15 anos de idade, houve uniformidade para o alcoolismo-doenca, que no sexo masculino variou de 6% a 13%, e no feminino de 0,7% a 1,4%. Em relacao as internacoes, constatamos que o diagnostico de alcoolismo alcanca elevada proporcao nos estabelecimentos psiquiatricos do pais, a qual, somada a esquizofrenia, compreende 50% do total destas internacoes. Foi impossivel generalizar os dados para todo o Brasil, devido a heterogeneidade cultural e economica da populacao, a extensao territorial, aos criterios divergentes de classificacao utilizados pelos diferentes autores, e a escassez de estudos que fornecam taxas de prevalencia.

Behavior of triatomines (Hemiptera: Reduviidae) vectors of Chagas' disease: I. Courtship and copulation of Panstrongylus megistus (Burm-1835) in the laboratory

Abstract: A study of the courtship and copulation behavior of Panstrongylus megistus was carried out in the laboratory. Fifty-five newly-fed virgin couples were used. Experiments were performed during the day (9:00 to 12:00 a.m.) and at night (7:00 to 10:00 p.m.). Behavior was recorded by direct observation and was found to consist of the following sequence of behavioral patterns: the male approached the female and jumped on her or mounted her; he took on a dorsolateral position and immobilized the female dorsally and ventrally with his three pairs of legs; the male genital was placed below those of the female; the paramers of the male immobilized the female's genitals; copulation started. The couple joined by the iniciative of the male. The female could be receptive and accept copulation, or nonreceptive and reject the male. Copulation occurred more often on the occasion of the first attempt by the male. Duration of copulation was X = 29.3 +/- 9.3 min (CV = 83%). No behavioral differences were observed between couples tested during the day or at night.

Ruralização da Lutzomyia intermedia, um provável caso de pré-adaptação

Abstract: A Lutzomyia intermedia ha muito vem sendo encontrada em areas de colonizacao antiga Analisando dados de capturas deste flebotomineo, com diferentes iscas e em diferentes locais, acredita-se que esta especie esta pre-adaptada a ambientes abertos e a se alimentar em mamiferos, entre eles o homem

Estudo comparativo entre o método convencional e o método da peroxidase anti-peroxidase na pesquisa do parasitismo tissular na cardiopatia chagásica crônica

Abstract: In most patients with chronic Chagas disease the Trypanosoma cruzi has been shown to be present in extremely scanty numbers in all tissues extensively studied using conventional non-specific histologic techniques presently available. The present work was carried out in order to compare the immunocytochemical method of peroxidase anti-peroxidase (PAP) with the Haematoxilin and Eosin (HE) technique in the quantification of the parasitism in formalin fixed tissues from chronic chagasic patients. Using the same tissue fragment from each one of 3 cases of chronic chagasic cardiomyopathy, sections were obtained for HE (average: 100 sections per fragment) and for PAP (average: 70 sections per fragment). The fragment from case Nip. 1 was first studied in 1952 and presented with relatively great number of parasites. The results, expressed as amastigotes nests per 100 sections stained by HE and PAP were, respectively (HE — PAP): case No. 1, 80 — 171; case No. 2, 5-116 and case No. 3, 1-2. The present results show that the immunocytochemical method improves the quantitative evaluation of the parasitism in tissues of chronic Chagas disease. Furthemore. it should be preferred not only for the specific diagnosis taut also for quantitative studies on the tissular parasitism even in those tissues included in paraffin wax for long periods of time.

Trypanosoma cruzi : Inhibition of host cell uptake of infective bloodstream forms by alpha-2-macroglobulin

Abstract: The infection of murine macrophages and fibroblasts by recently isolated infective bloodstream trypomastigotes ofTrypanosoma cruzi is inhibited by the addition of human plasma protease inhibitor alpha-2-macroglobulin (α2M) or of soybean trypsin inhibitor. The ingestion of the non-infective epimastigotes by macrophages is not affected by the physiological protease inhibitor. Incubation of bloodstream trypomastigotes for 20 h in a serum-free axenic medium enhances their ability to infect macrophages in a process influenced by the temperature and sensitive to α2M. After this period the infectivity of the parasites to cells was not sensitive to α2M. These observations suggest that proteases located on the surface and/or secreted by the bloodstream trypomastigote form ofT. cruzi may modulate its ability to infect host cells.

Study of molluscs of the genus biomphalaria from State of Minas Gerais in regard with host parasite adaptation and importance in epidemiology of schistosomiasis

Abstract: Biomphalaria tenagophila and B. straminea snails bred from snails collected at 8 counties of Minas Gerais, Brazil, were infected with Schistosoma mansoni miracidia of the strains LE and SJ. The percent experimental infection range was 0-28% for B. tenagophila and 0-21% for B. straminea. These results were compared with the ones by other authors showing that more than 70% of 32 populations from Minas Gerais (12 populations of B. tena- gophila and 20 of B. straminea) were suscep- tible to experimental infection with S. mansoni. These experimental data together with reports claiming the finding of naturally S. mansoni infected B. tenogophila and B. straminea at four localities since 1982 seem to indicate the existance of favourable conditions to the pre-adaptation to parasitism, as no infected snails had been found in these regions before. This adaptation has been described to occur in Sao Paulo and in brazilian northeastern region. These data are important to the control of the dissemination of schistosomiass to undamaged areas, as these two species of Biomphalaria are widely distributed in Brazil.

Non‐radioactive nucleic acid probes for the diagnosis of virus infections

Abstract: Nucleic acid hybridization is being increasingly used in viral diagnosis. Most of the assays described so far for this purpose require the use of radioactive probes. Their replacement by Non-radioactive assays has many advantages and makes the technique feasible in routine diagnostic work. Non-radioactive assays have had limited use but their diagnostic value has been demonstrated for a number of virus infections. They have the main advantages of employing stable probes, of avoiding safety hazards and of being easy and rapid to perform with limited laboratory facilities. Their main disadvantage compared to radioactive assays is in having relatively low sensitivity. Improvements in probe construction, in labelling and detecting methods, in sample treatment and in hybridization conditions may well increase their usefulness.

Variação da pressão arterial em trabalhadores de uma siderúrgica

Abstract: Com o objetivo de estudar a evolucao da pressao arterial ao londo da vida ativa de nove categorias de trabalhadores da Companhia Siderurgica Nacional de Volta Redonda (Rio de Janeiro, Brasil), foi analisada uma amostra de 426 homens, atraves das fichas do servico medico. Destas fichas, foram coletadas as pressoes registradas na admissao na empresa e no ultimo exame de rotina. Cerca de 90% dos trabalhadores tinham idades entre 20 e 50 anos em qualquer das medidas e o intervalo medio entre estas foi de 13,5 anos para aqueles com pelo menos 5 anos de atividade. Nao foi possivel rejeitar a homogeneidade das ideias de incrementos anuais de sistolica e diastolica entre os grupos ocupacionais. Em relacao as variacoes observadas, houve incrementos estatisticamente significativos na sistolica apenas para os trabalhadores de escritorio e almoxarifado, laboratorio e controle de qualidade, com pelos menos 5 anos de atividade. Quanto a diastolica, as categorias que sofreram incremento significativo foram escritorio e almoxarifado, maquinaria e ocupacoes especificas da producao, eletro-mecânicas de manutencao, construcao civil, transporte e comunicacoes e trabalhadores nao-qualificados. Tambem foi analisada a passagem destes trabalhadores de um status de pressao normal para outro de pressao mais elevada (sistolica 140 ou diastolica 90 mmHg). Com relacao a sistolica, apenas os funcionarios nao-qualificados mudaram de categoria; quanto a diastolica, repetiram-se os achados para incremento de pressao. O grupo da construcao civil destacou-se pelo maior aumento de diastolica entre as duas medidas, ao passo que os administradores e profissionais tecnico-cientificos foram os que apresentaram as menores variacoes de pressao. Fatores ambientais como ruido, calor, linha de montagem e outros implicados na elevacao de pressao arterial estao presentes nesta industria siderurgica. Os dados apontam maior risco de elevacao de pressao arterial em alguns grupos ocupacionais, o que justifica abordagens diferenciadas pelo servico medico da empresa.

A comparison of simian rotavirus SA11 preparations maintained in different laboratories

Abstract: Preparations of simian SA11 maintained in different laboratories were compared with each other by polyacrylamide gel electrophoresis of genomic RNA. Differences in the migration of genome segments 4,5 and 7 allowed the classification of eight virus preparations into four electrophoretic types.

Mortalidade por causas externas no estado do Rio de Janeiro no período de 1976 a 1980

Abstract: O presente trabalho teve por objetivo o de determinar as tendencias da mortalidade por causas externas no periodo de 1976 a 1980, no Estado do Rio de Janeiro. Foram estudadas as principais causas externas de obito e sua distribuicao temporal e espacial. Os acidentes de trânsito de veiculo a motor se revelaram como a principal causa externa de morte e, entre eles, os atropelamentos mostraram-se de real gravidade, sobretudo entre as criancas em idade escolar (5 a 14 anos). O estudo revelou um aumento de 70% na taxa de homicidios nos 5 anos pesquisados, e estes ja se constituem no principal f ator de mortalidade entre os adultos jovens de 20 a 29 anos. Evidenciou-se, tambem, grande numero de obitos classificados como "lesoes ignoradas se acidental ou intencionalmente infligidas", apontando para falhas no sistema de classificacao dos obitos por causas externas no Estado do Rio de Janeiro.

Platelet involvement in rat paw edema induced by 2-methoxy-PAF.

Abstract: PAF-acether (PAF) or 2-methoxy-PAF (2-MX) caused a dose-dependent paw edema showing a 1: 25 ratio between their inflammatory activities. 2-MX caused a thrombocytopenia, whereas PAF did not alter the number of these cells. Both phospholipids induced reductions in total leukocyte count. Rat antiplatelet serum produced platelet depletion by PAF-induced paw edema was unaffected. The edema of 2-MX was significantly reduced by antiplatelet serum, under conditions where normal serum was inactive against the edema induced by PAF or 2-MX. Histopathological analysis of PAF and 2-MX-induced edema showed, in the first case, a small infiltrate of neutrophils, some lymphocytes, and several mastocytes around the vessels and, in the second, a neutrophilic infiltrate. These results suggest that PAF and 2-MX may produce edema through different mechanisms and that 2-MX causes edema in part through platelet activation.