EFAR - Escola de Farmácia
URI permanente desta comunidadehttp://www.hml.repositorio.ufop.br/handle/123456789/451
Notícias
O curso de Farmácia em Ouro Preto foi criado em 1839, sendo a mais antiga Escola de Farmácia da América Latina.
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7 resultados
Resultados da Pesquisa
Item Increase of reactive oxygen species by desferrioxamine during experimental Chagas' disease.(2010) Francisco, Amanda Fortes; Vieira, Paula Melo de Abreu; Arantes, Jerusa Marilda; Silva, Maísa; Pedrosa, Maria Lúcia; Santos, Silvana Maria Elói; Martins Filho, Olindo Assis; Carvalho, Andréa Teixeira de; Araújo, Márcio Sobreira SilvaOxidative stress is common in inflammatory processes associated with many diseases including Chagas’ disease. The aim of the present study was to evaluate, in a murine model, biomarkers of oxidative stress together with components of the antioxidant system in order to provide an overview of the mechanism of action of the iron chelator desferrioxamine (DFO). The study population comprised 48 male Swiss mice, half of which were treated daily by intraperitoneal injection of DFO over a 35-day period, while half were administered sterile water in a similar manner. On the 14th day of the experiment, 12 DFO-treated mice and an equal number of untreated mice were experimentally infected with Trypanosoma cruzi. Serum concentrations of nitric oxide and superoxide dismutase and hepatic levels of total glutathione, thiobarbituric acid reactive species and protein carbonyl, were determined on days 0, 7, 14 and 21 post-infection. The results obtained revealed that DFO enhances antioxidant activity in the host but also increases oxidative stress, indicating that the mode of action of the drug involves a positive contribution to the host together with an effect that is not beneficial to the parasite.Item Different infective forms trigger distinct immune response in experimental Chagas disease.(2012) Vieira, Paula Melo de Abreu; Franscisco, Amanda Fortes; Machado, Evandro Marques de Menezes; Nogueira, Nívia Carolina; Fonseca, Kátia da Silva; Reis, Alexandre Barbosa; Carvalho, Andréa Teixeira de; Martins Filho, Olindo Assis; Tafuri, Washington Luiz; Carneiro, Cláudia MartinsAlthough metacyclic and blood trypomastigotes are completely functional in relation to parasite-host interaction and/or target cell invasion, they differ in the molecules present on the surface. Thus, aspects related to the variability that the forms of T. cruzi interacts with host cells may lead to fundamental implications on the immune response against this parasite and, consequently, the clinical evolution of Chagas disease. We have shown that BT infected mice presented higher levels of parasitemia during all the acute phase of infection. Moreover, the infection with either MT or BT forms resulted in increased levels of total leukocytes, monocytes and lymphocytes, specifically later for MT and earlier for BT. The infection with BT forms presented earlier production of proinflammatory cytokine TNF-a and later of IFN-c by both T cells subpopulations. This event was accompanied by an early cardiac inflammation with an exacerbation of this process at the end of the acute phase. On the other hand, infection with MT forms result in an early production of IFN-c, with subsequent control in the production of this cytokine by IL-10, which provided to these animals an immunomodulatory profile in the end of the acute phase. These results are in agreement with what was found for cardiac inflammation where animals infected with MT forms showed intense cardiac inflammation later at infection, with a decrease in the same at the end of this phase. In summary, our findings emphasize the importance of taking into account the inoculums source of T. cruzi, since vectorial or transfusional routes of T. cruzi infection may trigger distinct parasite-host interactions during the acute phase that may influence relevant biological aspects of chronic Chagas disease.Item Usefulness of the polymerase chain reaction for monitoring cure of mice infected with different Trypanosoma cruzi clonal genotypes following treatment with benznidazole.(2008) Miyamoto, Cláudia Tiemi; Gomes, Mônica Lúcia; Marangon, Aline Vansan; Araújo, Silvana Marques de; Bahia, Maria Terezinha; Martins Filho, Olindo Assis; Lana, Marta de; Toledo, Max Jean de OrnelasThe capacity of the polymerase chain reaction (PCR) to detect the DNA of Trypanosoma cruzi was evaluated in 90 blood samples from BALB/c mice infected with T. cruzi cloned stocks of genotypes 19 and 20 (T. cruzi I) and 39 and 32 (T. cruzi II), and treated with benznidazole. The results from the fresh blood examination, hemoculture, and ELISA allowed to group the treated animals into: cured (TC), dissociated (DIS) and non-cured (NC). The PCR detected T. cruzi DNA in 50.9%, 58.3% and 100.0% of the samples from TC, DIS and NC mice, respectively. These DNA possibly derives from live T. cruzi or from recently lysed parasites, suggests that these animals are in fact not cured. The difference between the PCR results and results obtained using other techniques was statistically significant and independent of the parasite genotype. The PCR described has therefore potential to be used in cure control of treated patients.Item Follow-up of experimental chronic Chagas’ disease in dogs : use of polymerase chain reaction (PCR) compared with parasitological and serological methods.(2002) Araújo, Flávio Marcos Gomes de; Bahia, Maria Terezinha; Magalhães, Neuza Maria de; Martins Filho, Olindo Assis; Veloso, Vanja Maria; Carneiro, Cláudia Martins; Tafuri, Washington Luiz; Lana, Marta deIn this study, the polymerase chain reaction (PCR) was compared with parasitological and serological methods to detect the infection in dogs, 5–12 years after experimental infection with Trypanosoma cruzi. The ability of parasitological methods to identify a positive animal was 22 and 11% by hemoculture and xenodiagnosis/xenoculture, respectively. On the other hand, the serological tests, including conventional serology and anti-live trypomastigote antibodies (ALTA) were positive in all infected dogs. Despite its low sensitivity, if considering only one reaction, the PCR analysis showed 100% of positivity, demonstrating the presence of parasite kDNA in all infected dogs. To identify a positive dog required at least two blood samples and up to nine repeated reactions using the same sample. Serial blood sample collection, ranging from 1 to 9, revealed that the percentage of dogs with positive PCR ranged from 67 to 100%. These findings suggested that, although the PCR is useful to detect the parasite in infected hosts, it should not be used isolated for the diagnosis of Chagas’ disease and warn for the necessity of serial blood collection and re-tests. Moreover, these data validate once more the dog as a model for Chagas’ disease since they demonstrate the permanence of infection by PCR, parasitological and serological methods, reaching relevant requisites for an ideal model to study this disease.Item Trypanosoma cruzi : desferrioxamine decreases mortality and parasitemia in infected mice through a trypanostatic effect.(2011) Arantes, Jerusa Marilda; Francisco, Amanda Fortes; Vieira, Paula Melo de Abreu; Silva, Maísa; Araújo, Márcio Sobreira Silva; Carvalho, Andréa Teixeira de; Pedrosa, Maria Lúcia; Carneiro, Cláudia Martins; Tafuri, Washington Luiz; Martins Filho, Olindo Assis; Santos, Silvana Maria ElóiDesferrioxamine (DFO) is a potent iron chelator that is also known to modulate inflammation and act as an efficient antioxidant under normal conditions and under oxidative stress. Many in vitro and in vivo studies have shown the efficacy of DFO in the treatment of viral, bacterial and protozoan infections. DFO is known to reduce the intensity of Trypanosoma cruzi infections in mice even during a course of therapy that is not effective in maintaining anaemia or low iron levels. To further clarify these findings, we investigated the action of DFO on mouse T. cruzi infection outcomes and the direct impact of DFO on parasites. Infected animals treated with DFO (5 mg/animal/day) for 35 days, beginning 14 days prior to infection, presented lower parasitemia and lower cumulative mortality rate. No significant effect was observed on iron metabolism markers, erythrograms, leukograms or lymphocyte subsets. In the rapid method for testing in vivo T. cruzi susceptibility, DFO also induced lower parasitemia. In regard to its direct impact on parasites, DFO slightly inhibited the growth of amastigotes and trypomastigotes in fibroblast culture. Trypan blue staining showed no effects of DFO on parasite viability, and only minor apoptosis in trypomastigotes was observed. Nevertheless, a clear decrease in parasite mobility was detected. In conclusion, the beneficial actions of DFO on mice T. cruzi infection seem to be independent of host iron metabolism and free of significant haematological side effects. Through direct action on the parasite, DFO has more effective trypanostatic than trypanocidal properties.Item Differential impact of metacyclic and blood trypomastigotes on parasitological, serological and phenotypic features triggered during acute Trypanosoma cruzi infection in dogs.(2007) Carneiro, Cláudia Martins; Martins Filho, Olindo Assis; Reis, Alexandre Barbosa; Veloso, Vanja Maria; Araújo, Flávio Marcos Gomes de; Bahia, Maria Terezinha; Lana, Marta de; Coelho, George Luiz Lins Machado; Gazzinelli, Giovanni; Oliveira, Rodrigo Corrêa de; Tafuri, Wagner LuizDifferential impact of metacyclic and blood trypomastigotes on parasitological, serological and phenotypic features triggered during acute Trypanosoma cruzi infection in dogs A detailed follow-up investigation of the major parasitological, serological and phenotypic features in dogs experimentally infected with metacyclic (MT) and blood (BT) trypomastigotes of Trypanosoma cruzi strain Berenice-78, typifying vectorial and transfusional transmission of human Chagas disease, has been conducted. Although there were no changes with respect to the window of patent-parasitaemia, significant differences between MT- and BT-infected dogs in both the prepatent period (days 23 and 19, respectively) and the day of maximum parasitaemia (days 26 and 22, respectively) were recorded. A progressive enhancement in the level of T. cruzi -specific antibodies accompanied infection by both MT and BT forms, although higher IgG titres developed on days 14 and 21 following infection with MT forms. Higher Thy-1 + /CD21 + and lower CD4 + /CD8 + cell ratios, occasioned by increased levels of Thy-1 + and CD8 + T-cells and reduced frequencies of CD4 + T-cells and CD21 + B-lymphocytes, were observed in both MT- and BT-infected animals. The reduced frequency of CD14 + leukocytes was revealed as the most relevant phenotypic feature intrinsic to T. cruzi infection independent of inoculum source. BT-specific phenotypic features included an early reductionItem Trypanosoma cruzi : immunoglobulin isotype profiles during the acute phase of canine experimental infection with metacyclic or blood trypomastigotes.(2008) Vital, Wendel Coura; Carneiro, Cláudia Martins; Martins, Helen Rodrigues; Lana, Marta de; Veloso, Vanja Maria; Carvalho, Andréa Teixeira de; Bahia, Maria Terezinha; Oliveira, Rodrigo Corrêa de; Martins Filho, Olindo Assis; Tafuri, Wagner Luiz; Reis, Alexandre BarbosaA detailed investigation has been carried out about the serological profiles of groups of dogs experimen-tally infected with metacyclic (MT) or blood (BT) trypomastigotes of Berenice-78 Trypanosoma cruzi strain. Peripheral blood was collected from infected dogs and uninfected controls, weekly during 35 days following the acute phase of infection, and immunoglobulin profiles were determined by ELISA. Dogs infected with BT exhibited unaltered levels of IgG2, increases in IgM, IgE, IgA, IgG and IgG1. In contrast, dogs infected with MT presented unaltered levels of IgE and IgG1 and an increase in IgM, IgA, IgG and IgG2 levels. Compared with the MT group, animals infected with BT showed significant increases in IgM on days 7, 14 and 28, in IgA on days 7, 14 and 21, in IgE on days 7 and 14, in IgG on days 14 and 28, and in IgG1 on days 7, 14 and 21. Parasitemia levels of the infected animals were measured over the same time period. No correlations were found between the immunoglobulin profiles and the parasi-temia levels. The results demonstrated that the inoculum source (BT or MT) influence the immunoglob-ulin isotype profile that may drive distinct outcome of acute canine Chagas disease