1000 resultados para Two-soliton resonances
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Cyclospora cayetanensis is a coccidium which has been identified in diarrheal feces or immunocompetent individuals or in AIDS patients. The main aspects related to its epidemiology and pathogeny have not been solved so far, as well as the possibility of human infection by this protozoan being a zoonosis. We describe in this work the first case identifying the Cyclospora in dogs. Our findings, notwithstanding their preliminary characteristics, could suggest that besides untreated water, other transmission means, along with contact with dogs, there could be important factors in the human diarrhea associated with Cyclospora
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Two cases of subcutaneous scedosporiosis, caused by Scedosporium apiospermum, are reported. Both patients had lesions localized in the forearm: a solitary ulceration in one and a sporotrichoid-like lesion in the other. The literature is reviewed
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Two cases of Chronic Pulmonary Histoplasmosis are reported and other eleven cases, collected from Brazilian literature, are commented. After being clinically cured, one of our patients presented an Aspergillus fungus ball inside a cavitation in the wall of which H. capsulatum was disclosed. Comments are also done on the diagnosis of the mycosis
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To evaluate the prevalence of antibodies against hepatitis A in two socioeconomically distinct populations, 101 and 82 serum samples from high and low socioeconomic groups, respectively, were analysed for the presence of IgG anti-HAV using a commercial ELISA. The prevalence in low socioeconomic level subjects was 95.0%, whereas in high socioeconomic subjects was only 19.6% (p<0.001). These data show a duality in Brazil: anti-HAV prevalence in low socioeconomic subjects is similar to that of developing countries, while in high socioeconomic subjects, a pattern typical of developed countries is found. The control of this infection in our country is primarily related to the improvement of sanitation, but especially for high socioeconomic level populations, the use of vaccination against hepatitis A is strongly advisable to avoid the occasional appearance of this disease in adults.
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Two cases of ectopic cutaneous schistosomiasis are described. Both patients presented with abdominal papular skin lesions, which on biopsy were found to contain granulomas with Schistosoma mansoni eggs. Twenty-five other cases were retrieved from the literature. Most patients were female, mean age 24.9 year, with a predominance of the white race. The most common localization was anterior thorax and abdomen. Usually, the lesions were asymptomatic. In few cases, however, severe clinical syndromes due to the parasite coexisted, such as transverse myelitis or the acute-toxemic form of the disease. Intestinal infection was not frequently demonstrated in these patients. The importance of the recognition of these cutaneous lesions may rest on the opportunity to provide an etiological diagnosis in these difficult cases.
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The records of the first two Colombian patients with AIDS and paracoccidioidomycosis are presented. Both patients were males and had no known risk factors for HIV although in the past they had worked in the field where they could have been infected with the fungus. They exhibited the juvenile type of disease with multiple organ system involvement and symptoms of short duration. They were deeply immunodepressed as indicated by less than 100 CD4 T lymphocytes per mL; however, serologic tests revealed circulating anti-Paracoccidioides brasiliensis antibodies and in one patient the first diagnostic clue came from such tests. In one case, the mycosis preceded the AIDS diagnosis while in the other, both pathologies were discovered simultaneously. Antimycotic therapy with itraconazole was administered for over 10 months, with an initial dose of 200 mg/day followed by 100 mg/day; marked improvement of the mycotic signs and symptoms was soon noticed an there have been no signs of relapse. The patients´ improvement was also due to the combined retroviral treatment that was instituted. In spite of the rarity of the AIDS-paracoccidioidomycosis association, physicians practicing in endemic areas should consider the presence of the mycosis in immunosuppressed patients, since a prompt diagnosis and institution of combined antimycotic-anti-retroviral treatments would result in patient improvement and survival. It appears possible that the longer survival time of today's AIDS patients would give the quiescent fungus the opportunity to revive, multiply and cause overt disease.
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Dissertação apresentada na Faculdade de Ciências e Tecnologia da Universidade Nova de Lisboa para obtenção do grau de Mestre em Biotecnologia
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The authors conducted a mycologic, immunochemical and molecular biology study on two strains of Paracoccidioides brasiliensis, one of them, called IBIÁ, isolated from soil in the municipality of IBIÁ (Minas Gerais) by Silva-Vergara et al. (l996,1998)20,21, and the other, BAT, cultivated from a human case of paracoccidioidomycosis in Ribeirão Preto (São Paulo/Brazil) by Freitas da Silva (l996)6. Both strains showed cotton-like (M) and yeast-like (Y) forms and were pathogenic for testicularly inoculated guinea pigs, producing granulomatous and/or suppurative orchitis. Immunochemically was demonstrated the presence of gp43 by double immunodiffusion, immunoelectrophoresis and immunoblotting.
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The authors report two cases of onychomycosis in the dystrophic form, one of them involving an HIV-positive patient, provoked by Scytalidium dimidiatum, previously called Scytalidium lignicola. The subject is reviewed from the taxonomic viewpoint, considering the anamorph Hendersonula toruloidea as a synonym of Nattrassia mangiferae, and having Scytalidium dimidiatum as the major synanamorph. According to many mycologists, Scytalidium hyalinum may be a separate species or a hyaline mutant of Scytalidium dimidiatum. Scytalidium lignicola Pesante 1957 was considered to be the type-species of the genus by ELLIS (1971)13 and later to be a "conidial state" of Hendersonula toruloidea by the same author, today known as Nattrassia mangiferae. The microorganism lives only on the roots of certain plants (mainly Platanus and Pinus). It produces pycnidia and is not considered to be a pathogen, although it is considered as a possible emerging agent capable of provoking opportunistic fungal lesions. The importance of this topic as one of the most outstanding in fungal taxonomy, so likely to be modified over time, as well as its interest in the field of dermatologic mycology, are emphasized.
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O vírus da hepatite delta (HDV) é o agente etiológico de uma das formas mais graves de hepatite viral e é ainda endémico em diversas regiões do globo, nomeadamente em África, na Amazónia e no Extremo Oriente. O HDV co-infecta ou super-infecta hepatócitos infectados com o vírus da hepatite B (HBV) aumentando em cerca de 10 vezes o risco de cirrose e hepatite fulminante. A associação clínica entre os dois vírus deve-se ao facto do invólucro do HDV ser constituído pelos antigénios de superfície do HBV (HBsAgs) que são necessários para a propagação da infecção. O genoma do HDV é constituído por uma molécula de RNA de cadeia simples, circular, com cerca de 1.7 Kb, que possui cerca de 70% de emparelhamento interno. Foi identificada uma única grelha de leitura aberta (ORF) no RNA viral que codifica para o antigénio delta (HDAg). A ocorrência de um mecanismo de editing do RNA, resulta na expressão de duas formas do HDAg, a pequena (S-HDAg) e a grande (L-HDAg). Várias funções essenciais para a replicação do HDV têm sido atribuídas a ambas as formas do HDAg, sendo a S-HDAg essencial para a acumulação de RNA viral e a L-HDAg responsável pela interacção com os HBsAgs para formar partículas virais. No entanto, dada a simplicidade dos seus componentes, admite-se que a replicação viral depende das interacções estabelecidas entre os HDAgs e factores celulares do hospedeiro. Apesar do número considerável de factores celulares descritos como interactores dos HDAgs ou RNA virais, a importância de muitas destas interacções não foi elucidada e muitas etapas do ciclo de replicação do HDV permanecem pouco claras. Para além disso, dado o número limitado de factores do hospedeiro que estão envolvidos na sua replicação, é muito provável que um número elevado de interactores do HDV permaneça por identificar. Este trabalho teve como objectivo a identificação de proteínas de fígado humano capazes de interagir com os HDAgs, utilizando o sistema yeast Two-Hybrid (YTH). Identificaram-se trinta proteínas com capacidade de interagir com a S-HDAg no sistema YTH, sendo que estas proteínas se encontram envolvidas em diferentes processos celulares. Com base nas características funcionais, foram seleccionadas três destas proteínas e as suas interacções com a S-HDAg foram investigadas com maior detalhe. As três proteínas seleccionadas foram a ribonucleoproteína nuclear heterogénea C (hnRNPC), a embryonic lethal abnormal vision like1 (ELAVL1/HuR) e a proteína 2 de ligação a EBNA1 (EBP2). As duas primeiras são proteínas de ligação a RNA, previamente descritas como envolvidas em processos de replicações de outros vírus com genoma RNA, enquanto a EBP2, é uma proteína de localização preferencialmente nucleolar, tal como por vezes acontece com os HDAgs. As interacções foram analisadas recorrendo a vários ensaios bioquímicos. No caso da hnRNPC e da HuR, após validação no sistema YTH, a capacidade de interacção com a S-HDAg foi confirmada quer in vitro por blot overlay quer in vivo por co-imunoprecipitação em células de hepatoma humano. Nas mesmas células, observou-se uma co-localização considerável entre os HDAgs e os RNAs virais. Finalmente, de modo a investigar a contribuição das proteínas hnRNPC e HuR na replicação do HDV, procedeu-se ao silenciamento destas proteínas pela utilização de short hairpin RNAs (shRNAs) específicos para os mRNAs correspondentes Observou-se que o silenciamento de ambas as proteínas hnRNPC e HuR endógenas, individualmente resultou numa diminuição acentuada nos níveis de expressão dos HDAgs. No que respeita à EBP2, a interacção com a S-HDAg foi confirmada em condições in vitro com recurso a ensaios de blot overlay e de cromatografia de afinidade. A análise por imunofluorescência indirecta e microscopia confocal revelou co-localização elevada entre os HDAgs e a EBP2, principalmente nos nucléolos de células de hepatoma humano. Finalmente, foi ainda utilizado o sistema YTH para estudar os mecanismos de importação dos HDAgs. Assim, este sistema foi utilizado com o propósito de identificar proteínas celulares capazes de interagir com um domínio específico dos HDAgs, o sinal de localização nuclear (NLS). Na pesquisa YTH realizada obtiveram-se 161 clones positivos, sendo que um deles mostrou codificar para a carioferina α4 (KPNA4). A interacção da KPNA4 com a S-HDAg foi reproduzida em condições in vitro através de um ensaio de cromatografia de afinidade tendo sido utilizadas formas recombinantes das duas proteínas. Este trabalho permitiu identificar várias proteínas celulares que interagem com a S-HDAg. Obtiveram-se evidências sugestivas de que algumas das proteínas identificadas podem desempenhar funções importantes no ciclo de replicação do HDV e que abrem novas perspectivas para o estudo do ciclo de replicação do vírus.
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Congenital Chagas disease (CChD) has been reported in different countries, mostly in Latin America. In 1987 a fatal case of CChD of second generation (CChDSG) was published. Within a period of six months - 1989-1990 - two cases of CChDSG were diagnosed and studied in the city of Santiago. Two premature newborns, sons of two sisters, with moderate liver and spleen enlargement, were found to have positive serology for Chagas disease and xenodiagnoses. The mothers, urban residents all their lives, without antecedents of triatomine bugs contact or blood transfusions, showed positive serology and xenodiagnoses. Their mother (grandmother of the infants), lived 20 years in a Northern rural Chagas disease endemic locality, in a triatomine infested house. Afterwards, she moved to Santiago, where she married and has resided up to now. Serology and xenodiagnoses were also positive. All the Trypanosoma cruzi infected individuals were successfully treated with nifurtimox.
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In the present study, we have analyzed by sodium docecyl sulphate - polyacrilamide gel electrophoresis (SDS-PAGE), immunoblotting and Concanavalin A blotting (Con A blotting) proteins of membrane fractions and soluble fractions obtained from Giardia duodenalis trophozoites of two axenic strains isolated in Brazil from a symptomatic (BTU-11) and an asymptomatic patient (BTU-10), as compared to the reference strain Portland 1. Both Brazilian strains showed a complex and homogeneous electrophoretic pattern of proteins, but some differences could be observed. Several glycoproteins were detected, particularly the proteins of 81, 72, 59 kDa and the protein of 62 kDa in the membrane proteins and cytosol, respectively. Many antigenic components were revealed by anti-Giardia rabbit IgG antibodies in the immunoblotting analysis. Among these components, the membrane protein of 32 kDa and the cytosol protein of 30 kDa could be related to giardin, as previously demonstrated.
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Deegan and Packel (1979) and Holler (1982) proposed two power indices for simple games: the Deegan–Packel index and the Public Good Index. In the definition of these indices, only minimal winning coalitions are taken into account. Using similar arguments, we define two new power indices. These new indices are defined taking into account only those winning coalitions that do not contain null players. The results obtained with the different power indices are compared by means of two real-world examples taken from the political field.