Débora de Oliveira Lopes

Sm21.6 a novel EF-hand family protein member located on the surface of Schistosoma mansoni adult worm that failed to induce protection against challenge infection but reduced liver pathology.

Schistosomiasis continues to be a significant public health problem that affects 200 million people worldwide. This is one of the most important parasitic diseases, and one whose effective control is unlikely in the absence of a vaccine. In this study, we have isolated a cDNA clone encoding the Schistosoma mansoni Sm21.6 protein that has 45% and 44% identity with Sm22.6 and Sj21.7 EF-hand containing antigens, respectively. Confocal microscopy analysis revealed that Sm21.6 is a membrane-associated protein localized on the S. mansoni adult worm. Mouse immunization with rSm21.6 induced a mixed Th1/Th2 cytokine profile and no protection against infection. However, vaccination with rSm21.6 reduced by 28% of liver granuloma numbers, 21% of granuloma area and 34% of fibrosis. Finally, rSm21.6 was recognized by sera from individuals resistant to reinfection compared with patients susceptible to reinfection and this molecule should be further studied as potential biomarker for disease resistance. In conclusion, Sm21.6 is a new tegument protein from S. mansoni that plays an important role in reducing pathology induced by parasite infection.

Biochemical studies with DNA polymerase β and DNA polymerase β-PAK of Trypanosoma cruzi suggest the involvement of these proteins in mitochondrial DNA maintenance

Mammalian DNA polymerase beta is a nuclear enzyme involved in the base excision and single-stranded DNA break repair pathways. In trypanosomatids, this protein does not have a defined cellular localization, and its function is poorly understood. We characterized two Trypanosoma cruzi proteins homologous to mammalian DNA polymerasebeta, TcPolbeta and TcPolbetaPAK, and showed that both enzymes localize to the parasite kinetoplast. In vitro assays with purified proteins showed that they have DNA polymerization and deoxyribose phosphate lyase activities. Optimal conditions for polymerization were different for each protein with respect to dNTP concentration and temperature, and TcPolbetaPAK, in comparison to TcPolbeta, conducted DNA synthesis over a much broader pH range. TcPolbeta was unable to carry out mismatch extension or DNA synthesis across 8-oxodG lesions, and was able to discriminate between dNTP and ddNTP. These specific abilities of TcPolbeta were not observed for TcPolbetaPAK or other X family members, and are not due to a phenylalanine residue at position 395 in the C-terminal region of TcPolbeta, as assessed by a site-directed mutagenesis experiment reversing this residue to a well conserved tyrosine. Our data suggest that both polymerases from T. cruzi could cooperate to maintain mitochondrial DNA integrity through their multiple roles in base excision repair, gap filling and translesion synthesis.

Immunization with SmIg, a novel tegument protein from Schistosoma mansoni, fails to induce protection in mice but reduces liver pathology.

Proteins associated with the schistosome tegument are of great importance for the development of new intervention strategies since they may be exposed on the surface of the parasite. Herein, we have isolated a cDNA clone encoding for the Schistosoma mansoni SmIg and its recombinant protein was tested as a potential vaccine candidate. Initially, its amino acid sequence was analysed by bioinformatics and shown to possess an N-terminal signal peptide, a C-terminal transmembrane helix, 4 glycosylation sites, an immunoglobulin conserved domain and 73% similarity with a hypothetical S. japonicum protein of unknown function. SmIg was produced by E. coli as a recombinant protein (rSmIg) and its protective effectiveness was evaluated against S. mansoni infection with 100 cercariae in a murine model. Mice immunized with rSmIg induced an immune response characterized by dominant IgG1 isotype and significant levels of IFN-gamma, TNF-alpha, IL-10 and IL-4. Although immunogenic, the recombinant vaccine failed to induce worm burden reduction when compared to the infected control group. However, rSmIg-immunized mice had significant reductions of liver granuloma volume and fibrosis content by 31.8% and 49%, respectively. In conclusion, SmIg is a new tegument protein from S. mansoni that plays an important role in reducing pathology induced by parasite infection.

Clinical, Molecular, and Epidemiological Analysis of Dengue Cases during a Major Outbreak in the Midwest Region of Minas Gerais, Brazil

This study aims to perform the first molecular and clinical-epidemiological analysis of dengue cases in Divinopolis, MG, Brazil. Data from 4,110 cases of dengue were accessed and 190 clinical samples were collected for molecular analyses. In this study, 2.7% of the men and 3.0% of the women were admitted to hospital. There was no association between gender and hospital admission. The symptoms observed in this study are according to the Health Ministry, but fever was present in 82.2% and not in 100% of cases. The chance of hospital admission was 1.55 higher in patients with any kind of bleeding (334) and 2.4% of individuals without bleeding were also hospitalized due to other warning signs. In the molecular analyses, 23% of the samples were positive for DENV. DENV-2 and DENV-3 were identified in 2010, DENV-3 in 2011, DENV-1 in 2012, and DENV-1 and DENV-4 in 2013. DENV detection was possible in samples with only one day of symptoms. This first report of dengue data in Divinópolis provided more insight into the viral types and effects of disease in the city, confirming the need for caution in assessing cases of suspected dengue and for revision of the criteria proposed by the Health Ministry to classify cases of the disease.

21‑Benzylidene digoxin, a novel digoxin hemi-synthetic derivative, presents an anti-inflammatory activity through inhibition of edema, tumour necrosis factor alpha production, inducible nitric oxide synthase expression and leucocyte migration

&NA; Recent findings have demonstrated new therapeutic functions of cardiotonic steroids, a process that is termed drug repositioning. Despite the confirmed anti‐inflammatory effects of cardiotonic steroids, their clinical use has been discouraged due to toxicity related to inhibition of the Na+/K+ ATPase. A novel synthetic compound derived from digoxin, 21‐benzylidene digoxin (21‐BD), does not inhibit this enzyme. Herein, we evaluated the anti‐inflammatory and antinociceptive effects and acute toxicity of 21‐BD. Murine (Swiss mice) models of paw oedema induced by carrageenan, acetic acid‐induced abdominal writhing, and formalin and acute toxicity tests were used. Oral administration of 21‐BD (0.3 mg/kg) showed a significant and prolonged inhibition of paw oedema. Histological analysis demonstrated a reduction in inflammatory cells and expression of inducible nitric oxide synthase (iNOS) in footpads 6 h after administration of carrageenan. 21‐BD (0.3 mg/kg) also reduced the levels of tumour necrosis factor (TNF)‐&agr; 2 and 4 h after carrageenan. 21‐BD demonstrated antinociceptive activity, inhibiting abdominal writhes at all tested doses. However, in the formalin test, 21‐BD did not present antinociceptive activity. In the acute toxicity test, 21‐BD did not cause symptoms of toxicity or mortality. The present study demonstrated, for the first time, that 21‐BD is safe and exhibits a marked anti‐inflammatory activity in acute local inflammation. This effect might be a consequence of its ability to inhibit the release of the PMN leucocyte‐derived mediators, including TNF‐&agr;, and iNOS expression as well as its inhibitory effect on oedema and PMN leucocyte infiltration.

Occurrence of schistosomiasis in Divinópolis-MG based on study of schoolchildren and surveys of disease notification

Introduction: Schistosomiasis is a neglected chronic disease that affects mainly underdeveloped regions, including Brazil. Objective: To evaluate the distribution profile of the schistosomiasis in Divinopolis-MG. Material and methods: It is characterized as a descriptive and analytical epidemiological study. A parasitological study performed in schoolchildren of public municipal schools; simultaneously, a survey of schistosomiasis cases reported in the city between 2005 and 2011 years was performed with the Municipal Department of Health. Data related to the characteristics of the infection were observed, such as: affected areas, age, gender, and professional occupation. Results: This survey showed 33 cases of schistosomiasis in the city during this period, which the most of them (84.8%) were between 20-59 years of age. The results of the study with the schoolchildren are in agreement with those obtained through the reporting forms, both indicating no occurrence of schistosomiasis in individuals between 6-14 years of age in Divinopolis. Conclusion: The absence of the disease in children and adolescents analyzed and the presence in adults is a strong evidence of exogenous contamination in the city, especially as a result of immigration or rural tourism, and possible changes in habits, related to risk factors.

Cervical uterine lesions: An epidemiological and molecular investigation in midwestern Minas Gerais, Brazil

Cervical uterine cancer is the second most frequent form of cancer in the female population and the fourth cause of cancer deaths among Brazilian women. In Divinópolis county, Minas Gerais state, cervical cancer accounted for 6.6% of deaths in 2007. The purpose of this study was to conduct an epidemiological and molecular investigation of samples of pre‐neoplastic and neoplastic cervical uterine lesions from patients assisted at public healthcare services in the county. The study was based on clinical–epidemiological descriptions retrieved from cytological examination request forms from 2006 to 2010. For molecular analysis, samples from 95 patients were collected and DNA was extracted using the Chelex 100 method. PCR was performed for detection and typing of HPV 6/11, 16, 18, 31, and 33. Of the 52 168 patients who underwent cytological examination, 625 had pre‐neoplastic or neoplastic lesions during the study period. Age distribution was consistent with the literature, with a predominance of patients aged 20–49 years. The microorganism found most frequently was Lactobacillus sp. (65%). Prominent among cellular alterations were cervical intraepithelial neoplasia I (39.7%) and atypical squamous cells of undetermined significance (32%). Molecular analysis revealed 72.6% of positive samples for HPV. HPV 16 (26.3%) was the most frequent type, followed by types 6/11 (7.4%), 18 (5.3%), 33 (2.1%), and 31 (1%). The results provided improved understanding of the association between HPV and cancer in Divinópolis, in addition to providing data that can contribute to the design of measures to prevent and control HPV infection in the county investigated. J. Med. Virol. 85:860–865, 2013.