DESENVOLVIMENTO E AVALIAÇÃO DE ELETRODOS DE DIFUSÃO GASOSA (EDG) PARA GERAÇÃO DE H2O2 IN SITU E SUA APLICAÇÃO NA DEGRADAÇÃO DO CORANTE REATIVO AZUL 19

DEVELOPMENT AND EVALUATION OF GAS DIFFUSION ELECTRODES (GDE) FOR GENERATION OF H2O2 IN SITU AND THEIR APPLICATION IN THE DEGRADATION OF REACTIVE BLUE 19 DYE. This work reports the development of GDE for electrogeneration of H2O2 and their application in the degradation process of Reactive Blue 19 dye. GDE produced by carbon black with 20% polytetrafluoroethylene generated up to 500 mg L-1 of H2O2 through the electrolysis of acidic medium at -0.8 V vs Ag/AgCl. Reactive Blue 19 dye was degraded most efficiently with H2O2 electrogenerated in the presence of Fe(II) ions, leading to removal of 95% of the original color and 39% of TOC at -0.8 V vs Ag/AgCl.

Photodynamic therapy in actinic cheilitis: clinical and anatomopathological evaluation of 19 patients

BACKGROUND: Actinic cheilitis, a common disease caused by chronic solar exposure and tobacco use, is considered a premalignant lesion with potential to develop into squamous cell carcinoma. Some of the available treatments are invasive, have unaesthetic results and require multiple sessions. OBJECTIVE: To assess the efficacy of a therapy and its cosmetic results. METHODS: In this uncontrolled clinical trial a single photodynamic therapy (PDT) session using 16% methyl-aminolevulinate was performed on actinic cheilitis of the lower lip. A standardized questionnaire was applied in order to assess the clinical improvement from the patients' point of view and the satisfaction with the treatment. Anatomopathological evaluation was performed before the treatment and two months afterwards. RESULTS: The sample was composed of 19 patients (10 males and 9 females), phototypes I to III, with average age of 62 years. Main adverse effects were: sudden pain, scabs, herpes flare-up, and edema. The average score of pain during the procedure was 5,8+2,9. At the final assessment the patients reported improvement of 80% and satisfaction of 85% (p<0.01). Anatomopathological analysis showed a significant decrease of dysplasia (p=0.03) in spite of its presence in 84% of cases. There was no significant correlation between the level of dysplasia with either the subjective impression of clinical improvement (p=0.82) or with the patients' final satisfaction (p=0.96). CONCLUSION: PDT is effective in the treatment of actinic cheilitis, but it is associated with a significant level of pain. Due to the persistence of dysplasia, more research needs to be done in order to define the ideal number of sessions for the effective treatment of these lesions.

Naturally acquired antibodies to Plasmodium vivax blood-stage vaccine candidates (PvMSP-1(19) and PvMSP-3 alpha(359-798)) and their relationship with hematological features in malaria patients from the Brazilian Amazon

An important step when designing a vaccine is identifying the antigens that function as targets of naturally acquired antibodies. We investigated specific antibody responses against two Plasmodium vivax vaccine candidates, PvMSP-1(19) and PvMSP-3 alpha(359-798). Moreover, we assessed the relationship between these antibodies and morbidity parameters. PvMSP-1(19) was the most immunogenic antigen and the frequency of responders to this protein tended to increase in P. vivax patients with higher parasitemia. For both antigens, IgG antibody responses tended to be lower in patients who had experienced their first bout of malaria. Furthermore, anemic patients presented higher IgG antibody responses to PvMSP-3 alpha(359-798). Since the humoral response involves a number of antibodies acting simultaneously on different targets, we performed a Principal Component Analysis (PCA). Anemic patients had, on average, higher first principal component scores (IgG1/IgG2/IgG3/IgG4 anti-MSP3 alpha), which were negatively correlated with hemoglobin levels. Since antibodies against PfMSP-3 have been strongly associated with clinical protection, we cannot exclude the possibility of a dual role of PvMSP-3 specific antibodies in both immunity and pathogenesis of vivax malaria. Our results confirm the high immunogenicity of the conserved C terminus of PvMSP-1 and points to the considerable immunogenicity of polymorphic PvMSP-3 alpha(359-798) during natural infection. (C) 2012 Institut Pasteur. Published by Elsevier Masson SAS. All rights reserved.

Serological detection of Plasmodium vivax malaria using recombinant proteins corresponding to the 19-kDa C-terminal region of the merozoite surface protein-1

Abstract Background Serological tests to detect antibodies specific to Plasmodium vivax could be a valuable tool for epidemiological studies, for screening blood donors in areas where the malaria is not endemic and for diagnosis of infected individuals. Because P. vivax cannot be easily obtained in vitro, ELISA assays using total or semi-purified antigens are rarely used. Based on this limitation, we tested whether recombinant proteins representing the 19 kDa C-terminal region of the merozoite surface protein-1 of P. vivax (MSP119) could be useful for serological detection of malaria infection. Methods Three purified recombinant proteins produced in Escherichia coli (GST-MSP119, His6-MSP119 and His6-MSP119-PADRE) and one in Pichia pastoris (yMSP119-PADRE) were compared for their ability to bind to IgG antibodies of individuals with patent P. vivax infection. The method was tested with 200 serum samples collected from individuals living in the north of Brazil in areas endemic for malaria, 53 serum samples from individuals exposed to Plasmodium falciparum infection and 177 serum samples from individuals never exposed to malaria. Results Overall, the sensitivity of the ELISA assessed with sera from naturally infected individuals was 95%. The proportion of serum samples that reacted with recombinant proteins GST-MSP119, His6-MSP119, His6-MSP119-PADRE and yMSP119-PADRE was 90%, 93.5%, 93.5% and 93.5%, respectively. The specificity values of the ELISA determined with sera from healthy individuals and from individuals with other infectious diseases were 98.3% (GST-MSP119), 97.7% (His6-MSP119 and His6-MSP119-PADRE) or 100% (yMSP119-PADRE). Conclusions Our study demonstrated that for the Brazilian population, an ELISA using a recombinant protein of the MSP119 can be used as the basis for the development of a valuable serological assay for the detection of P. vivax malaria.

Desenvolvimento e avaliação de eletrodos de difusão gasosa (EDG) para geração de H2O2 in situ e sua aplicação na degradação do corante reativo azul 19

This work reports the development of GDE for electrogeneration of H2O2 and their application in the degradation process of Reactive Blue 19 dye. GDE produced by carbon black with 20% polytetrafluoroethylene generated up to 500 mg L-1 of H2O2 through the electrolysis of acidic medium at -0.8 V vs Ag/AgCl. Reactive Blue 19 dye was degraded most efficiently with H2O2 electrogenerated in the presence of Fe(II) ions, leading to removal of 95% of the original color and 39% of TOC at -0.8 V vs Ag/AgCl.