The anticancer drug tamoxifen is active against Trypanosoma cruzi in vitro but ineffective in the treatment of the acute phase of Chagas disease in mice

The activity of the antineoplastic drug tamoxifen was evaluated against Trypanosoma cruzi. In vitro activity was determined against epimastigote, trypomastigote and amastigote forms of CL14, Y and Y benznidazole resistant T. cruzi strains. Regardless of the strain used, the drug was active against all life-cycle stages of the parasite with a half maximal effective concentration ranging from 0.7-17.9 µM. Two experimental models of acute Chagas disease were used to evaluate the in vivo efficacy of treatment with tamoxifen. No differences in parasitemia and mortality were observed between control mock-treated and tamoxifen-treated mice.FAPESPFIOCRUZCNP

Óbito por dengue 4 no Brasil em paciente com púrpura trombocitopênica idiopática

Dengue é atualmente um importante problema de saúde pública. O vírus da dengue (DENV) é classificado em quatro sorotipos distintos, DENV 1-4. Após 28 anos de ausência, o DENV-4 foi detectado novamente no Brasil em 2010 no Estado de Roraima, e um ano depois, o vírus foi identificado em outros estados do norte do país, Amazonas e Pará, seguido pelos estados do Rio de Janeiro e São Paulo. Em Minas Gerais, o primeiro caso confirmado de DENV-4 ocorreu no município de Frutal em 2011 e, desde então, o sorotipo foi isolado em um número crescente de pacientes. Apesar do DENV-2 estar associado a um maior risco de formas graves e morte, o DENV-4 também tem sido associado a casos graves e a risco aumentado de manifestações hemorrágicas. Neste relato, descrevemos o primeiro caso fatal confirmado por DENV-4 no Brasil. A paciente era uma menina de 11 anos do município de Montes Claros, no norte de Minas Gerais, Brasil. Apresentava púrpura trombocitopênica idiopática e evoluiu de forma fulminante durante a infecção por dengue, com óbito associado a complicações hemorrágicas. O diagnóstico foi confirmado pela detecção de anticorpos IgM específicos para dengue, por método imunoenzimático, e por semi-nested RT-PCR. Médicos e outros profissionais de saúde devem estar cientes que infecções por DENV-4 também podem resultar em formas graves da doença com complicações hemorrágicas e óbito, principalmente em pacientes com comorbidades.Dengue is currently a major public-health problem. Dengue virus (DENV) is classified into four distinct serotypes, DENV 1-4. After 28 years of absence, DENV-4 was again detected in Brazil in 2010 in Roraima State, and one year later, the virus was identified in the northern Brazilian states of Amazonas and Pará, followed by Rio de Janeiro and São Paulo. In Minas Gerais, the first confirmed case of DENV-4 occurred in the municipality of Frutal in 2011 and has now been isolated from a growing number of patients. Although DENV-2 is associated with the highest risk of severe forms of the disease and death due to the infection, DENV-4 has also been associated with severe forms of the disease and an increasing risk of hemorrhagic manifestations. Herein, the first fatal case of confirmed DENV-4 in Brazil is reported. The patient was an 11-year-old girl from the municipality of Montes Claros in northern Minas Gerais State, Brazil. She had idiopathic thrombocytopenic purpura as a comorbid condition and presented with a fulminant course of infection, leading to death due to hemorrhagic complications. Diagnosis was confirmed by detection of Dengue-specific antibodies using IgM capture enzyme-linked immunosorbent assay and semi-nested RT-PCR. Primary care physicians and other health-care providers should bear in mind that DENV-4 can also result in severe forms of the disease and lead to hemorrhagic complications and death, mainly when dengue infection is associated with coexisting conditions

FATAL OUTCOME OF INFECTION BY DENGUE 4 IN A PATIENT WITH THROMBOCYTOPENIC PURPURA AS A COMORBID CONDITION IN BRAZIL

Dengue is currently a major public-health problem. Dengue virus (DENV) is classified into four distinct serotypes, DENV 1-4. After 28 years of absence, DENV-4 was again detected in Brazil in 2010 in Roraima State, and one year later, the virus was identified in the northern Brazilian states of Amazonas and Pará, followed by Rio de Janeiro and São Paulo. In Minas Gerais, the first confirmed case of DENV-4 occurred in the municipality of Frutal in 2011 and has now been isolated from a growing number of patients. Although DENV-2 is associated with the highest risk of severe forms of the disease and death due to the infection, DENV-4 has also been associated with severe forms of the disease and an increasing risk of hemorrhagic manifestations. Herein, the first fatal case of confirmed DENV-4 in Brazil is reported. The patient was an 11-year-old girl from the municipality of Montes Claros in northern Minas Gerais State, Brazil. She had idiopathic thrombocytopenic purpura as a comorbid condition and presented with a fulminant course of infection, leading to death due to hemorrhagic complications. Diagnosis was confirmed by detection of Dengue-specific antibodies using IgM capture enzyme-linked immunosorbent assay and semi-nested RT-PCR. Primary care physicians and other health-care providers should bear in mind that DENV-4 can also result in severe forms of the disease and lead to hemorrhagic complications and death, mainly when dengue infection is associated with coexisting conditions

Influence of citocinas and cells of the immune system in the activity of the inibidor of the biossintese of ergosterol (posaconazol) in the experimental infection by the trypanosoma cruzi

Submitted by Repositório Arca ([email protected]) on 2019-05-07T13:26:29Z No. of bitstreams: 2 license.txt: 1748 bytes, checksum: 8a4605be74aa9ea9d79846c1fba20a33 (MD5) marcela_lencine.pdf: 1480816 bytes, checksum: 38e40b7d7fde58cd1f3f9b2660b80451 (MD5)Approved for entry into archive by Nuzia Santos ([email protected]) on 2019-09-20T17:18:23Z (GMT) No. of bitstreams: 2 marcela_lencine.pdf: 1480816 bytes, checksum: 38e40b7d7fde58cd1f3f9b2660b80451 (MD5) license.txt: 1748 bytes, checksum: 8a4605be74aa9ea9d79846c1fba20a33 (MD5)Made available in DSpace on 2019-09-20T17:18:23Z (GMT). No. of bitstreams: 2 marcela_lencine.pdf: 1480816 bytes, checksum: 38e40b7d7fde58cd1f3f9b2660b80451 (MD5) license.txt: 1748 bytes, checksum: 8a4605be74aa9ea9d79846c1fba20a33 (MD5) Previous issue date: 2005Fundação Oswaldo Cruz. Centro de Pesquisas René Rachou. Belo Horizonte, MG, Brasil.A doença de Chagas afeta aproximadamente 18 milhões de pessoas na América Latina. O Benzonidazol (BZ) é o único fármaco utiliza do no Brasil para o tratamento e apresenta eficácia limitada na fase crônica da doença ou no tratamento de indivíduos imunossuprimidos. Na tentativa de identificar novos fármacos para o tratamento da doença de Chagas, observou- se que o Trypanosoma cruzi necessita de ergosterol para a sua sobrevivência e seu crescimento. O parasito não pode utilizar o colesterol do hospedeiro e é sensível aos inibidores da biossíntese de ergosterol (IBEs). Os bis-triazóis são uma nova geração de IBEs, que foram ativos nas fases aguda e crônica da doença de Chagas experimental. Entre eles, o Posaconazol (POS) destacou-se, apresentando eficácia no combate ao T. cruzi “in vitro” e “in vivo”. O POS é uma droga candidata ao tratam ento clínico da doença de Chagas. Nesta dissertação, nós avaliamos a atividade do POS em camundongos deficientes em populações de linfócitos (TCD4 + , TCD8 + , B) e citocinas (IFN- γ e IL-12), na tentativa de identificar se há influência de alguns efetores da resposta imune na eficácia terapêutica da droga. Os camundongos deficientes (knockouts) foram infectados com a cepa Y de T. cruzi (5000 tripomastigotas/camundongo) e foram tratados por 20 dias consecutivos. Para fins comparativos, camundongos deficientes também foram tratados com BZ, assim como camundongos selvagens C57Bl/6. A parasitemia foi realizada até 60 dias após a infecção, como descrito por Brener (1962). No mesmo período, a sobrevivência dos camundongos foi monitorada. Entre 30-40 dias após o término do tratamento, camundongos com parasitemia não detectáel ao microscópio óptico foram submetidos à hemocultura, para determinar a cura. Considerando a sobrevida e a cura dos camundongos knockouts infectados pelo T. cruzi, observamos que é necessária a interação entr e o sistema imune do hospedeiro e as drogas estudadas, para que se obtenha cura parasitológica. Os linfócitos T CD4 + foram essenciais para a atividade do POS e BZ e a sua ausência torna os animais altamente suscetíveis. A citocina IFN- γ também foi essencial para o tratamento com BZ, porém, o POS foi menos influenciado por este componente. Os camundongos deficientes em linfócitos T CD8 + tiveram os melhores resultados quando tratados com BZ, ao contrário dos camundongos deficientes em linfócitos B que foram mais curados pelo POS. Nos camundongos deficientes em IL-12, o POS e o BZ tiveram a mesma atividade para reativação, mortalidade e cura. Os nossos resultados sugerem que ambas as drogas são in fluenciadas por componentes específicos do sistema imunológico. Porém, possuem mecanismo s distintos de atuação e interação com o sistema imune.Chagas disease affects 18 million people approximately in Latin America. Benznidazol (BZ) is the only drug used in Brazil for the treatment and it presents limited effectiveness in the chronic phase of the disease or in the treatment of individuals imunossupressed. In the attempt of identifying new drugs for the treatment of Chagas disease, it was observed that the Trypanosoma cruzi needs of ergosterol for survival a nd growth. The parasite cannot use the cholesterol of the host and it is sensitive to the ergosterol biosynthesis inhibitors (IBEs). The bis-triazols are a new generation of IBEs, that were active in the acute and chronic phases of the experimental Chagas disease. Among them, Posaconazole (POS), presenting effectiveness in the combat to T. cruzi "in vitro" and "in vivo". POS is a dr ug of choice for clinical trials in human Chagas disease. In this dissertation, we evaluated the activity of the POS in deficient mice in populations of lymphocytes (TCD4 + , TCD8 + , B) and cytokines (IFN- γ and IL-12), in the attempt of identifying if there is influence of some efectors of the immune system in the therapeutic effectiveness of the drug. The defici ent mice (knockouts) were infected with the Y strain of T. cruzi (5000 trypomastigotes/mice) and they were treated by 20 consecutive days. For comparative ends, deficient mice were al so treated with BZ, as well as wild mice C57Bl/6. The parasitemia was accomplished up to 60 days after the infection, as described by Brener (1962). In the same period, the surv ival of the mice was monitored. Among 30-40 days after the end of the treatment, mice with parasitaemia no detectable to the optical microscope were submitted to the hemoculture, to determine the cure. Considering the survival and the cure of the mice knockouts infected by the T. cruzi , we observed that it is necessary the interaction between the immune system of the host and the studied drugs, so that it is obtained cure. The lymphocytes T CD4 + went essential for the activity of the POS and BZ and his absence turns the animals highly susceptible. The cytokine IFN- γ also went essential for the treatment with BZ, however, POS was it less influenced by this component. The deficient mice in lymphocytes T CD8 + had the best results when treaties with BZ, unlike the deficient mice in lymphocytes B that were more cured for the POS. In the deficient mice in IL-12, POS and BZ had the same activity for reactivation, mortality and cure. Our results suggest that both drugs are influenced by sp ecific components of the immunological system. However, they possess mechanisms different from performance and interaction with the immune system

Caracterização de potenciais alvos moleculares e teste de fármacos candidatos ao tratamento da doença de Chagas experimental

Submitted by Nuzia Santos ([email protected]) on 2017-08-30T16:41:35Z No. of bitstreams: 1 Marcela Lencine Ferraz.pdf: 52620176 bytes, checksum: 65da5b30d4dbc1d56a13ac087c714c09 (MD5)Approved for entry into archive by Nuzia Santos ([email protected]) on 2017-08-30T16:44:47Z (GMT) No. of bitstreams: 1 Marcela Lencine Ferraz.pdf: 52620176 bytes, checksum: 65da5b30d4dbc1d56a13ac087c714c09 (MD5)Made available in DSpace on 2017-08-30T16:44:47Z (GMT). No. of bitstreams: 1 Marcela Lencine Ferraz.pdf: 52620176 bytes, checksum: 65da5b30d4dbc1d56a13ac087c714c09 (MD5) Previous issue date: 2009Fundação Oswaldo Cruz. Centro de Pesquisas René Rachou. Belo Horizonte, MG, Brasil.No ano de comemoração do centenário de de scoberta da doença de Chagas ainda são muitos os desafios e as dificuldades na busca de novas alternativ as eficazes para o tratamento da doença. O objetivo deste trabalho foi caracterizar potenciais alvos moleculares e testar fármacos candidatos para o tratamento da doença de Chagas. Como alvos foram analisadas três enzimas: a Tiol Transferase (Tc52), a Glutamato Desidrogenase (TcGluDH) e a Aldo/ceto Reduta se (TcAKR), selecionadas a partir de prévias análises de genômica e proteômica em cepas de Trypanosoma cruzi sensíveis e resistentes ao Benzonidazol. Como poten ciais fármacos, foram escolhidos três medicamentos: o Tamoxifeno, a Amiodarona e o Ravuconazol, testados in vitro e in vivo, nas fases aguda e crônica da doença de Ch agas experimental. Para os testes in vivo os fármacos foram utilizados isoladamente ou em combinação. Adicionalmente, foi avaliado o efeito cooperativo do sistema imune na at ividade dos inibidores da biossíntese de ergosterol, Posaconazol e Ravuconazol. Os resultados mostraram que apenas a TcGluDH foi diferencialmente expressa, apresenta ndo uma menor expressão da proteína e do respectivo mRNA nas cepas re sistentes ao Benzonidazol em comparação com as cepas sensíveis. Para TcAKR não foi possível completar a caracterização, mas observamos um aumento no nível de mRNA nas cepas resist entes analisadas quando comparada com as sensíveis. Não houve correlação entre a expres são da Tc52 e o fenótipo de resistência a fármacos do T. cruzi. Nos testes de fármacos, as melhores resultados foram obtidos com a associação Ravuconazol e Amiodarona: 60% de cura e 90% de sobrevivência dos camundongos infectados e tratados nas fase s aguda e crônica. A associação entre Amiodarona e Benzonidazol não gerou efeito sinérgico ou aditivo na cura da doença de Chagas experimental. O Tamoxifeno apesar de ter se mostrado potente nos testes in vitro foi inativo in vivo. Com relação a avaliação da coopera ção do sistema imune na atividade do Posaconazol, nossos resultados mostraram uma nítida influência dos diferentes tipos de linfócitos na atividade desse fármaco assim como para o Benzonidazol. Provavelmente, esse efeito foi devido a ação preferencial de sses fármacos sobre diferentes estágios do parasito, em cooperação com diferentes el ementos do sistema imune. A utilização de camundongos knockout mostrou que a ausência de Interferon- reduziu a atividade do Ravuconazol e Benzonidazol. O presente trabalho abre perspectivas para serem exploradas.In the year of commemoration of the centenary of Chagas disease discovery, the challenges and difficulties in the search of new efficien t alternatives for the treatment of the illness still remain. The objectives of this work were to characterize potential molecular targets and test drugs candidates for the treatment of the Chagas disease. Three potential targets had been selected: Thiol Transferase (Tc5 2), Glutamate Dehidrogenase (TcGluDH) and the Aldo/Keto Reductase (TcAKR). They we re pointed out by genomic and proteomic analysis of Benznidazole susceptible and resistant Trypanosoma cruzi strains. As potential drugs, three medicines had been chosen: Ta moxifen (TAM), Amiodarone (AMIO) and Ravuconazole (RAVU). They were tested in vitro and in vivo , in the acute and chronic phases of the experimental Chagas disease. For the tests in vivo the drugs had been used separately or in combination. Additionally, we evaluate the cooperative effect of the host immune system in the activity of inhibitors of the biosynthesis of ergosterol, Posaconazole (POS) and RAVU. The results show that only the TcGluDH was differentially expressed, presenting a reduction in the prot ein expression and mRNA levels in resistant strains to Benznidazole. Although a complete characteri zation of TcAKR could not be reached, we observe difference in the mRNA levels in the strains analyzed. However no correlation between the expression of the Tc52 and resist ance phenotype was observed. In the tests of drugs, the highest activities were observed fo r RAVU and AMIO associ ation: 60% of cure and 90% of survival of the infected and trea ted mice in the chronic phase. The association between AMIO and BZ generate neither synerg ic or additive effect in the cure of the experimental Chagas disease. Although TAM presen ted high activity in vitro it was inactive in vivo . In regard to cooperation effect of the host immune system a clear influence of the lymphocytes were observed on the activity of POS and BZ. Our results show that the absence of different lymphocyt es activities has dist inct effects on the efficacy of POS and BZ in th e treatment of murine acute T. cruzi infection. Probably, this effect had the preferred stock of these drugs on different parasite stages, in cooperation with different elements of the immune syst em. The use of knockout mice showed that the absence of gamma interferon reduced the R AVU and BZ activities. The present work considers new alternatives for the Chagas di sease chemotherapy, and opens perspectives to be further explore

Deltamethrin toxicological profile of peridomestic Triatoma sordida in the North of Minas Gerais, Brazil

Submitted by Nuzia Santos ([email protected]) on 2016-02-25T18:39:05Z No. of bitstreams: 1 Deltamethrin toxicological profile of peridomestic Triatoma sordida in the North of Minas Gerais, Brazil.pdf: 5120034 bytes, checksum: cab9c44109ae839c9982847dfed5bb6b (MD5)Approved for entry into archive by Nuzia Santos ([email protected]) on 2016-02-25T18:48:00Z (GMT) No. of bitstreams: 1 Deltamethrin toxicological profile of peridomestic Triatoma sordida in the North of Minas Gerais, Brazil.pdf: 5120034 bytes, checksum: cab9c44109ae839c9982847dfed5bb6b (MD5)Made available in DSpace on 2016-02-25T18:48:00Z (GMT). No. of bitstreams: 1 Deltamethrin toxicological profile of peridomestic Triatoma sordida in the North of Minas Gerais, Brazil.pdf: 5120034 bytes, checksum: cab9c44109ae839c9982847dfed5bb6b (MD5) Previous issue date: 2015Fundação Oswaldo Cruz. Centro de Pesquisas René Rachou. Laboratório de Triatomíneos e Epidemiologia da Doença de Chagas. Belo Horizonte, MG, BrasilUniversidade Federal de Brasília. Laboratório de Entomologia. Brasília, DF, BrasilGerência Regional de Saúde de Montes Claros. Montes Claros, MG, BrasilSecretaria de Saúde do Estado de Minas Gerais. Belo Horizonte, MG, BrasilSecretaria de Saúde do Estado de Minas Gerais. Belo Horizonte, MG, BrasilFundação Oswaldo Cruz. Centro de Pesquisas René Rachou. Laboratório de Triatomíneos e Epidemiologia da Doença de Chagas. Belo Horizonte, MG, BrasilBackground: In general, there was a large reduction in the occurrence of cases of Chagas disease in the last decades in Brazil. However, despite all of these efforts, there have been various reports of persistent reinfestations of T. sordida in a large part of the state of Minas Gerais, for reasons still little investigated. Thus, this purpose of this study was to characterize the deltamethrin susceptibility profile of peridomestic T. sordida populations from North of Minas Gerais – Brazil. Methods: Susceptibility to deltamethrin was assessed in seventeen peridomestic populations of T. sordida from North region of Minas Gerais, Brazil. Serial dilutions of deltamethrin in acetone (0.2 μL) were topically applied in first instar nymphs (F1, five days old, fasting, weight 1.2 ± 0.2 mg). Dose response results were analyzed with POLO program, determining the lethal doses, slope and resistance ratios (RR). Results: Susceptibility profile characterization of T. sordida populations revealed resistance ratios (RR50) ranging from 2.50 to 7.08. Conclusions: In fact, we know very little about the real impact of the resistance ratios obtained in the laboratory bioassays on the effectiveness of the vector control activities in the field. Thus, we prefer to refer to the populations with RR > 5 as populations with altered susceptibility. For these populations, the realization of laboratory and field trials, simultaneous and complementary, permitting the evaluation of both, is recommended