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Simão Dias, Brazil

Gontijo V.S.,Federal University of Minas Gerais | Oliveira M.E.,Federal University of Sao Joao del Rei | Resende R.J.,Federal University of Sao Joao del Rei | Fonseca A.L.,Federal University of Sao Joao del Rei | And 9 more authors.
Medicinal Chemistry Research | Year: 2015

A series of novel long-chain alkyltriazoles were prepared from commercial diols in a rapid process with good yields. The compounds were evaluated in vitro for their anticancer potential against two human cancer cell lines: colon carcinoma (RKO) and uterine carcinoma (HeLa). The results of colorimetric MTT assays showed that six of fourteen compounds tested decreased cell viability in these cell lines. Compounds 5e and 6a were the most active against RKO cells, with IC50 values of 16.70 and 14.57 μM, respectively. The same compounds, 5e and 6a, were the most active in HeLa cells as well, with IC50 values of 11.05 and 12.77 μM, respectively. In addition, compound 5e was found to induce apoptosis in RKO cells, as assessed by TUNEL assay. The results suggest that compound 5e may be a promising prototype anticancer agent. © 2014 Springer Science+Business Media New York. Source


Suarez P.,Federal University of Para | Cardozo D.,Institute Biologia Subtropical | Baldo D.,Institute Biologia Subtropical | Pereyra M.O.,Museo Argentino de Ciencias Naturales Bernardino Rivadavia | And 9 more authors.
Cytogenetic and Genome Research | Year: 2013

Dendropsophini is the most species-rich tribe within Hylidae with 234 described species. Although cytogenetic information is sparse, chromosome numbers and morphology have been considered as an important character system for systematic inferences in this group. Using a diversity of standard and molecular techniques, we describe the previously unknown karyotypes of the genera Xenohyla , Scarthyla and Sphaenorhynchus and provide new information on Dendropsophus and Lysapsus . Our results reveal significant karyotype diversity among Dendropsophini, with diploid chromosome numbers ranging from 2n = 22 in S. goinorum , 2n = 24 in Lysapsus , Scinax , Xenohyla , and almost all species of Sphaenorhynchus and Pseudis , 2n = 26 in S. carneus , 2n = 28 in P. cardosoi , to 2n = 30 in all known Dendropsophus species. Although nucleolar organizer regions (NORs) and C-banding patterns show a high degree of variability, NOR positions in 2n = 22, 24 and 28 karyotypes and C-banding patterns in Lysapsus and Pseudis are informative cytological markers. Interstitial telomeric sequences reveal a diploid number reduction from 24 to 22 in Scarthyla by a chromosome fusion event. The diploid number of X. truncata corroborates the character state of 2n = 30 as a synapomorphy of Dendropsophus . © 2013 S. Karger AG, Basel. Source


Rivera Tapia J.A.,Institute Ciencias Of La Buap | Jose Antonio S.H.,Laboratorio Of Biologia Celular
Enfermedades Infecciosas y Microbiologia | Year: 2011

Introduction. Cell cultures are widely used in both biomedical and biotechnological research centers and industry, as well as for diagnostic tests in hospitals. Contamination of cell cultures with microbial organisms as well as with virus or other eukaryotic cell lines are a major problem in cell culture related research. Objective. Mycoplasmas detection in cell cultures came from biomedical laboratories. Material and Methods. The cell cultures screened for mycoplasmas by using microbiological culture and PCR. Cell cultures were grown in the absence of antibiotics for 3-4 days. Detection of mycoplasmas was based on alterations in the pH of the broth in the absence of turbidity, production of colonies with the aspect of fried eggs. Comparison between microbiological and PCR were made using Student T test. Results. Mycoplasmas were detected by culture in 9/20 (45%) of the cell culture samples and PCR revealed the presence of target DNA in 10/20 (50%) samples. Mycoplasmas detection between the microbiological culture and PCR show no significant differences (P>0.05). Conclusion. Mycoplasmas detection in cell cultures must be strengthened with another technique to validate the results. Source


Ennes-Vidal V.,Instituto Oswaldo Cruz IOC | Menna-Barreto R.F.S.,Laboratorio Of Biologia Celular | Santos A.L.S.,Federal University of Rio de Janeiro | Branquinha M.H.,Federal University of Rio de Janeiro | d'Avila-Levy C.M.,Instituto Oswaldo Cruz IOC
Journal of Antimicrobial Chemotherapy | Year: 2010

Objectives: There is a general lack of effective and non-toxic chemotherapeutic agents for treating Chagas' disease. In the present work, we evaluated the in vitro activity of the calpain inhibitor MDL28170 against Trypanosoma cruzi relevant clinical forms. Methods: The effect of MDL28170 on bloodstream trypomastigotes at different concentrations was assessed by counting the parasites in a Neubauer chamber, which allowed the determination of IC50 values. Sub-sequently, parasite-macrophage interaction was assessed by two approaches: (i) peritoneal mouse macrophages were pre-infected with trypomastigotes for 3 h and then treated daily for 72 h with MDL28170; or (ii) bloodstream trypomastigotes were pre-treated with the calpain inhibitor for 1 h and then subjected to the infection assay. Results: MDL28170 was capable of significantly reducing the viability of bloodstream trypomastigotes, presenting an IC50/24 h value of 20.4 μM. Also, parasites pre-treated with the inhibitor, at subinhibitory drug concentrations, prior to macrophage infection presented a clear dose-dependent inhibition profile, where the inhibition increased from 20% to 50% (in relation to control) as MDL28170 concentration rose from 6.25 to 50 μM. In addition, macrophages experimentally infected with T. cruzi that were treated with the calpain inhibitor presented a significant reduction in the percentage of infection even at the lowest concentrations (6.25 μM). Conclusions: These data may contribute to the study of the calpains in T. cruzi infection and add new in vitro insights into the possibility of exploiting calpains as promising targets to treat Chagas' disease. © The Author 2010. Source


Ennes-Vidal V.,Instituto Oswaldo Cruz IOC | Menna-Barreto R.F.S.,Laboratorio Of Biologia Celular | Santos A.L.S.,Federal University of Rio de Janeiro | Branquinha M.H.,Federal University of Rio de Janeiro | d'Avila-Levy C.M.,Instituto Oswaldo Cruz IOC
PLoS ONE | Year: 2011

Background: Trypanosoma cruzi is the etiological agent of Chagas' disease. During the parasite life cycle, many molecules are involved in the differentiation process and infectivity. Peptidases are relevant for crucial steps of T. cruzi life cycle; as such, it is conceivable that they may participate in the metacyclogenesis and interaction with the invertebrate host. Methodology/Principal Findings: In this paper, we have investigated the effect of the calpain inhibitor MDL28170 on the attachment of T. cruzi epimastigotes to the luminal midgut surface of Rhodnius prolixus, as well as on the metacyclogenesis process and ultrastructure. MDL28170 treatment was capable of significantly reducing the number of bound epimastigotes to the luminal surface midgut of the insect. Once the cross-reactivity of the anti-Dm-calpain was assessed, it was possible to block calpain molecules by the antibody, leading to a significant reduction in the capacity of adhesion to the insect guts by T. cruzi. However, the antibodies were unable to interfere in metacyclogenesis, which was impaired by the calpain inhibitor presenting a significant reduction in the number of metacyclic trypomastigotes. The calpain inhibitor also promoted a direct effect against bloodstream trypomastigotes. Ultrastructural analysis of epimastigotes treated with the calpain inhibitor revealed disorganization in the reservosomes, Golgi and plasma membrane disruption. Conclusions/Significance: The presence of calpain and calpain-like molecules in a wide range of organisms suggests that these proteins could be necessary for basic cellular functions. Herein, we demonstrated the effects of MDL28170 in crucial steps of the T. cruzi life cycle, such as attachment to the insect midgut and metacyclogenesis, as well as in parasite viability and morphology. Together with our previous findings, these results help to shed some light on the functions of T. cruzi calpains. Considering the potential roles of these molecules on the interaction with both invertebrate and vertebrate hosts, it is interesting to improve knowledge on these molecules in T. cruzi. © 2011 Ennes-Vidal et al. Source

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