DEFAR - Artigos publicados em periódicos
URI permanente para esta coleçãohttp://www.hml.repositorio.ufop.br/handle/123456789/531
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Item In vitro interaction of polyethylene glycol‐block‐poly (D,L‐lactide) nanocapsule devices with host cardiomyoblasts and trypanosoma cruzi‐infective forms.(2022) Siqueira, Raoni Pais; Milagre, Matheus Marques; Oliveira, Maria Alice de; Branquinho, Renata Tupinambá; Torchelsen, Fernanda Karoline Vieira da Silva; Lana, Marta de; Machado, Marina Guimarães Carvalho; Andrade, Margareth Spangler; Bahia, Maria Terezinha; Mosqueira, Vanessa Carla FurtadoChagas disease, caused by the protozoan Trypanosoma cruzi, is an important public health problem in Latin America. Nanoencapsulation of anti-T. cruzi drugs has signifcantly improved their efcacy and reduced cardiotoxicity. Thus, we investigated the in vitro interaction of polyethylene glycol-block-poly(D,L-lactide) nanocapsules (PEG-PLA) with trypomas- tigotes and with intracellular amastigotes of the Y strain in cardiomyoblasts, which are the infective forms of T. cruzi, using fuorescence and confocal microscopy. Fluorescently labeled nanocapsules (NCs) were internalized by non-infected H9c2 cells toward the perinuclear region. The NCs did not induce signifcant cytotoxicity in the H9c2 cells, even at the highest concentrations and interacted equally with infected and non-infected cells. In infected cardiomyocytes, NCs were distrib- uted in the cytoplasm and located near intracellular amastigote forms. PEG-PLA NCs and trypomastigote form interactions also occurred. Altogether, this study contributes to the development of engineered polymeric nanocarriers as a platform to encapsulate drugs and to improve their uptake by diferent intra- and extracellular forms of T. cruzi, paving the way to fnd new therapeutic strategies to fght the causative agent of Chagas disease.Item Synthesis, trypanocidal and cytotoxic activities of α,β-unsaturated ketones derived from eugenol and analogues.(2022) Reis, Rúbia Castro Fernandes Melo; Reis, Adriana Cotta Cardoso; Torchelsen, Fernanda Karoline Vieira da Silva; Lana, Marta de; Sales Júnior, Policarpo Ademar; Brandão, Geraldo Célio; Braga, Saulo Fehelberg Pinto; Souza, Thiago Belarmino deThis work describes the synthesis, structural characterization, trypanocide and cytotoxic evaluation of α,β-unsaturated ketones derived from eugenol and analogues. Among the synthesized compounds, the cyclopentanonic/dihydroeugenol derivative 12 was active against amastigote forms of Trypanosoma cruzi at 5.2 nM (700 times more potent than benznidazole) and represents a potential hit for future structural optimizations to reduce its toxicity. All the compounds were also evaluated against a healthy human and four cancer cell lines and the derivative 10 was more active than doxorubicin against three cancer cells (IC50 values between 2.03–23.51 μM) and showed the higher selectivity index considering the human cells. Derivative 14 was also more potent and selective than doxorubicin against two cancer cells (IC50 values between 4.71–8.86 μM).Item Lychnopholide in PLA-PEG nanocapsules cures infection by drug resistant Trypanosoma cruzi strain in acute and chronic phases.(2020) Branquinho, Renata Tupinambá; Mello, Carlos Geraldo Campos de; Oliveira, Maykon Tavares de; Reis, Levi Eduardo Soares; Vieira, Paula Melo de Abreu; Guimarães, Dênia Antunes Saúde; Mosqueira, Vanessa Carla Furtado; Lana, Marta deChagas disease remains neglected, and current chemotherapeutics present severe limitations. Lychnopholide (LYC) at low doses loaded in polymeric poly(d,l-lactide)-block-polyethylene glycol (PLA-PEG) nanocapsules (LYC-PLA-PEG-NC) exhibits anti-Trypanosoma cruzi efficacy in mice infected with a partially drug-resistant strain. This study reports the efficacy of LYC-PLA-PEG-NC at higher doses in mice infected with a T. cruzi strain resistant to benznidazole (BZ) and nifurtimox (NF) treated at both the acute phase (AP) and the chronic phase (CP) of infection by the oral route. Mice infected with the T. cruzi VL-10 strain were treated by the oral route with free LYC (12 mg/kg of body weight/day), LYC-PLA-PEG-NC (8 or 12 mg/kg/day), or BZ at 100 mg/kg/day or were not treated (controls). Treatment efficacy was assessed by hemoculture (HC), PCR, enzyme-linked immunosorbent assay (ELISA), heart tissue quantitative PCR (qPCR), and histopathology. According to classical cure criteria, treatment with LYC-PLA-PEG-NC at 12 mg/kg/day cured 75% (AP) and 88% (CP) of the animals, while at a dose of 8 mg/kg/day, 43% (AP) and 43% (CP) were cured, showing dose-dependent efficacy. The negative qPCR results for heart tissue and the absence of inflammation/fibrosis agreed with the negative results obtained by HC and PCR. Thus, the mice treated with the highest dose could be considered 100% cured, in spite of a low ELISA reactivity in some animals. No cure was observed in animals treated with free LYC or BZ or the controls. These results are exceptional in terms of experimental Chagas disease chemotherapy and provide evidence of the outstanding contribution of nanotechnology in mice infected with a T. cruzi strain totally resistant to BZ and NF at both phases of infection. Therefore, LYC-PLA-PEG-NC has great potential as a new treatment for Chagas disease and deserves further investigations in clinical trials.Item Increased body exposure to new anti-trypanosomal through nanoencapsulation.(2017) Branquinho, Renata Tupinambá; Lana, Gwenaelle Elza Nathalie Pound; Milagre, Matheus Marques; Guimarães, Dênia Antunes Saúde; Vilela, José Mário Carneiro; Andrade, Margareth Spangler; Lana, Marta de; Mosqueira, Vanessa Carla FurtadoLychnopholide, a lipophilic sesquiterpene lactone, is efficacious in mice at the acute and chronic phases of Chagas disease. Conventional poly-ε-caprolactone (PCL) and long-circulating poly(D,L-lactide)-block-polyethylene glycol (PLA-PEG) nanocapsules containing lychnopholide were developed and characterized. Lychnopholide presented high association efficiency (>90%) with the nanocapsules. A new, fast and simple HPLC-UV-based bioanalytical method was developed, validated in mouse plasma and applied to lychnopholide quantification in in vitro release kinetics and pharmacokinetics. The nanocapsules had mean hydrodynamic diameters in the range of 100–250 nm, negative zeta potentials (−30 mV to −57 mV), with good physical stability under storage. Atomic force microscopy morphological analysis revealed spherical monodispersed particles and the absence of lychnopholide crystallization or aggregation. Association of lychnopholide to PLA-PEG nanocapsules resulted in a 16-fold increase in body exposure, a 26-fold increase in plasma half-life and a dramatic reduction of the lychnopholide plasma clearance (17-fold) in comparison with free lychnopholide. The improved pharmacokinetic profile of lychnopholide in long-circulating nanocapsules is in agreement with the previously reported improved efficacy observed in Trypanosoma cruzi-infected mice. The present lychnopholide intravenous dosage form showed great potential for further pre-clinical and clinical studies in Chagas disease and cancer therapies.Item Preclinical monitoring of drug association in experimental chemotherapy of Chagas’ disease by a new HPLC-UV method.(2012) Silva, Ricardo Moreira da; Oliveira, Líliam Teixeira; Barcellos, Neila Marcia Silva; Souza, Jacqueline de; Lana, Marta deA combination of drugs in experimental chemotherapy of Chagas’ disease may increase the effectiveness of treatment. To evaluate the possible mechanisms that influence the improvement of therapy, we investigated the pharmacokinetic interaction between benznidazole and itraconazole in a murine model treated orally with single doses of 5 mg of each compound separately or together. Blood samples from treated mice were collected at different intervals for 48 h, and a high-performance liquid chromatography (HPLC)-UV method was used to quantify both drugs in the plasma. A decrease of 1.5-fold in the maximum drug concentration in the plasma (Cmax) and an increase of 2.66-fold in the volume of distribution (V) and 7.5-fold in the elimination half-life (t1/2 ) of benznidazole when coadministered with itraconazole were observed. The parameters area under the curve (AUC0-t), area under the curve extrapolated to infinity (AUC0- ), time to maximum concentration of drug in serum (Tmax), and clearance (CL) for benznidazole were not significantly different in this therapeutic regime. None of the evaluated parameters for ITC demonstrated a significant difference between isolated and associated administration. These results suggest that the main effect of this interaction leads to accumulation of benznidazole in the biological system. This effect may contribute to the improved therapeutic efficacy of this combination of drugs, in addition to synergism of the different mechanisms of action of benznidazole and itraconazole against Trypanosoma cruzi in vivo.Item Posttherapeutic cure criteria in Chagas disease : conventional serology followed by supplementary serological, parasitological, and molecular tests.(2012) Assis, Girley Francisco Machado de; Silva, Alexandre Rotondo da; Bem, Vitor Antônio Lemos do; Bahia, Maria Terezinha; Martins Filho, Olindo Assis; Dias, João Carlos Pinto; Viñas, Pedro Albajar; Torres, Rosália Morais; Lana, Marta deWe performed a critical study of conventional serology, followed by supplementary serological, parasitological, and molecular tests, to assess the response to etiologic treatment of Chagas’ disease. A group of 94 Chagas’ disease patients treated with benznidazole at least 10 years earlier were evaluated from the laboratory and clinical points of view. When conventional serology (enzyme- linked immunosorbent assay [ELISA], indirect immunofluorescence [IIF], and indirect hemagglutination [IHA]) and classic criteria (consistent results with any two of the three tests) or more rigorous criteria (consistent results from the three tests) were used, 10.6% and 8.5% of patients were considered treated and cured (TC) by classic and rigorous criteria, respectively. Patients were then evaluated using supplementary (recombinant ELISA and Trypanosoma cruzi excreted-secreted antigen blotting [TESA-blot]), parasitological (hemoculture), and molecular (PCR) tests. The results of recombinant ELISA were similar to those with the rigorous criterion (three consistent test results). The TESA-blot group showed a higher percentage (21.3%) of negative results than the groups defined by either cure criterion. Hemoculture and PCR gave negative results for all treated and cured (TC) patients, regardless of the criterion used. Recombinant ELISA and TESA-blot tests showed negative results for 70% and 87.5% of the patients categorized as TC by the classic and three-test criteria, respectively. For patients with discordant conventional serology, the supplementary serological and molecular tests were the decisive factor in determining therapeutic failure. Clinical evaluation showed that 62.5% of TC patients presented with the indeterminate form of the disease. Additionally, treated patients with negative TESA-blot results should be reevaluated later with all methodologies used here to verify whether TESAblot is a reliable way to determine early parasitological cure of Chagas’ disease.Item Heart autonomic innervation during the acute phase of the experimental American trypanosomiasis in the dog.(1998) Machado, Conceição Ribeiro da Silva; Caliari, Marcelo Vidigal; Lana, Marta de; Tafuri, Washington LuizHeart autonomic innervation was studied in dogs during the acute phase of the experimental infection with the Berenice-78 strain of Trypanosoma cruzi. A glyoxylic acid–induced fluorescence method for catecholamines and a thiocholine method for demonstrating acetylcholinesterase activity showed the sympathetic and the parasympathetic nerve fibers, respectively. At day 34 of infection, moderate-to-intense rarefaction of both cholinergic and noradrenergic nerve fibers occurred in the atria of all animals coincident with moderate to intense myocarditis. In the ventricles, sympathetic denervation was clearly present only when the inflammatory processes were moderate to intense. Preliminary results on the chronic phase indicate that normal autonomic innervation coexists with an incipient chronic fibrosing myocarditis.Item Compared vectorial transmissibility of pure and mixed clonal genotypes of Trypanosoma cruzi in Triatoma infestans.(1998) Pinto, Artur da Silveira; Lana, Marta de; Bastrenta, Brigitte; Barnabé, Christian; Quesney, Virginie; Noel, Sébastien; Tibayrenc, MichelA total of 15 mixtures involving 9 di erent stocks attributed to the 19/20, 32 and 39 major clonal genotypes of Trypanosoma cruzi were used to infect third-instar nymphs of Triatoma infestans via an arti®- cial feeding device. Three biological parameters were considered: (1) the percentage of infected insects (%II), (2) the number of ¯agellates per insect (NFI), and (3) the percentage of trypomastigotes per insect (%DIF). Ge- netic characterization by both multilocus enzyme elec- trophoresis (MLEE) and random ampli®cation of polymorphic DNA (RAPD) indicated that in almost all cases (87%), mixtures remained present after completion of the whole cycle in the insect vector. Two lines of comparison were performed: (1) pure clonal genotypes versus corresponding mixed clonal genotypes and (2) the actual behavior of mixed clonal genotypes versus the expected behavior of the theoretical mixture (i.e. the arithmetic mean of the results observed for each of the two clonal genotypes taken separately). Statistical analyses of the variables were made di cult because of the presence of large standard deviations. Nevertheless, in several cases, mixtures di ered signi®cantly from pure clonal genotypes, and in one case the actual mixture di ered signi®cantly from the theoretical mixture. In some cases, interaction (either potentialization or re- ciprocal inhibition) could be suspected.Item Characterization of two isolates of Trypanosoma cruzi obtained from the patient Berenice, the first human case of Chagas disease.(1996) Lana, Marta de; Chiari, Cléa de Andrade; Chiari, Egler; Morel, Carlos Medicis; Gonçalves, Antônio M.; Romanha, Alvaro JoséTwo isolates of Trypanosoma cruzi were obtained from the patient Berenice, the first human case of Chagas’ disease (Chagas 1909), when she was 55 and 71 years old, respectively. The isolates were characterized on the basis of their epimastigote-trypomastigote differentiation in liquid media and of the electrophoretic pattern of EcoR1 digestion products of kinetoplast DNA (k- DNA) minicircles (schizodeme) and isoenzyme patterns (zymodeme). Clear differences were found between the isolates, suggesting the occurrence of a heterogeneous population of T. cruzi in the infection of this patient.Item Are increased frequency of macrophage-like and natural killer (NK) cells, together with high levels of NK T and CD4+CD25high T cells balancing activated CD8+ T cells, the key to control Chagas'disease morbidity?.(2006) Avelar, Danielle Marchetti Vitelli; Avelar, Renato Sathler; Massara, Rodrigo Lima; Borges, Jaila Dias; Lage, Paula Souza; Lana, Marta de; Carvalho, Andréa Teixeira de; Dias, João Carlos Pinto; Santos, Silvana Maria Elói; Martins Filho, Olindo AssisThe immunological response during early human Trypanosoma cruzi infection is not completely understood, despite its role in driving the development of distinct clinical manifestations of chronic infection. Herein we report the results of a descriptive flow cytometric immunophenotyping investigation of major and minor peripheral blood leucocyte subpopulations in T. cruzi - infected children, characterizing the early stages of the indeterminate clinical form of Chagas’ disease. Our results indicated significant alterations by comparison with uninfected children, including increased values of pre-natural killer (NK)-cells (CD3 – CD16 + CD56 – ), and higher values of proinflammatory monocytes (CD14 + CD16 + HLA-DR ++ ). The higher values of activated B lymphocytes (CD19 + CD23 + ) contrasted with impaired T cell activation, indicated by lower values of CD4 + CD38 + and CD4 + HLA-DR + lymphocytes, a lower frequency of CD8 + CD38 + and CD8 + HLA-DR + cells; a decreased frequency of CD4 + CD25 HIGH regulatory T cells was also observed. These findings reinforce the hypothesis that simultaneous activation of innate and adaptive immunity mechanisms in addition to suppression of adaptive cellular immune response occur during early events of Chagas’ disease. Comparative cross-sectional analysis of these immunophenotypes with those exhibited by patients with late chronic indeterminate and cardiac forms of disease suggested that a shift toward high values of macrophage-like cells extended to basal levels of proinflammatory monocytes as well as high values of mature NK cells, NKT and regulatory T cells, may account for limited tissue damage during chronic infection favouring the establishment/maintenance of a lifelong indeterminate clinical form of the disease. On the other hand, development of an adaptive cell-mediated inflammatory immunoprofile characterized by high levels of activated CD8 + cells and basal levels of mature NK cells, NKT and CD4 + CD25 HIGH cells might lead to late chronic pathologies associated with chagasic heart disease.