415 research outputs found

    The effects of photodynamic treatment with new methylene blue N on the Candida albicans proteome.

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    Candida albicans is a human pathogenic fungus mainly affecting immunocompromised patients. Resistance to the commonly used fungicides can lead to poor treatment of mucosal infections which, in turn, can result in life-threatening systemic candidiasis. In this scenario, antimicrobial photodynamic treatment (PDT) has emerged as an effective alternative to treat superficial and localized fungal infections. Microbial death in PDT is a consequence of the oxidation of many cellular biomolecules, including proteins. Here, we report a combination of two-dimensional electrophoresis and tandem mass spectrometry to study the protein damage resulting from treating C. albicans with PDT with new methylene blue N and red light. Two-dimensional gels of treated cells showed an increase in acidic spots in a fluence-dependent manner. Amino acid analysis revealed a decrease in the histidine content after PDT, which is one plausible explanation for the observed acidic shift. However, some protein spots remained unchanged. Protein identification by mass spectrometry revealed that both modified and unmodified proteins could be localized to the cytoplasm, ruling out subcellular location as the only explanation for damage selectivity. Therefore, we hypothesize that protein modification by PDT is a consequence of both photosensitizer binding affinity and the degree of exposure of the photooxidizable residues on the protein surface

    Inhibitory action of phenothiazinium dyes against Neospora caninum.

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    Neospora caninum is an Apicomplexan parasite related to important losses in livestock, causing abortions and decreased fertility in affected cows. Several chemotherapeutic strategies have been developed for disease control; however, no commercial treatment is available. Among the candidate drugs against neosporosis, phenothiazinium dyes, offer a low cost-efficient approach to parasite control. We report the anti-parasitic effects of the phenothiaziums Methylene Blue (MB), New Methylene Blue (NMB), 1,9-Dimethyl Methylene Blue (DMMB) and Toluidine Blue O (TBO) on N. caninum, using in vitro and in vivo models. The dyes inhibited parasite proliferation at nanomolar concentrations (0.019-1.83 μM) and a synergistic effect was achieved when Methylene Blue was combined with New Methylene Blue (Combination Index = 0.84). Moreover, the phenothiazinium dyes improved parasite clearance when combined with Pyrimethamine (Pyr). Combination of Methylene Blue + 1,9-Dimethyl Methylene Blue demonstrated superior efficacy compared to Pyrimethamine based counterparts in an in vivo model of infection. We also observed that Methylene Blue, New Methylene Blue and 1,9-Dimethyl Methylene Blue increased by 5000% the reactive oxygen species (ROS) levels in N. caninum tachyzoites. Phenothiazinium dyes represent an accessible group of candidates with the potential to compound future formulations for neosporosis control

    Técnica da complementação de frases como recurso para expressão vivencial do aluno em véspera de prova

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    This article evaluates an alternative strategy of group intervention using the technique of complementing sentences to a group of students at University just before their examination. It aimed at offering to the nursing undergraduate students from the College of Nursing at Ribeirão Preto - University of São Paulo, a space to show their feelings related to this peculiar situation. The authors searched to catch the students' emotional conditions regarding their expectations as well as to identify possible aspects that can be handled looking at suggesting alternatives of intervention to alleviated tension.El presente artículo, evalúa la estrategia alternativa de la intervención en grupo mediante la técnica de la complementación de frases en Universitarios, en el día anterior de a pruebas de conocimientos. Tuvo como objetivos: a) ofrecer a los alumnos del curso de pre-grado en enfermería de la Escuela de Enfermería de Ribeirao Preto - USP, una posibilidad de expresión vivencial en situación específica; b) captar sus condiciones emocionales relacionadas a sus expectativas; c) identificar aspectos posibles de ser manejados y; de sugerir una posible alternativa de intervención para alivio de sus tensiones.O presente artigo avalia a estratégia alternativa de integração em grupo por meio da aplicação da técnica da complementação de frases em Universitários, em véspera de prova. Teve como objetivo: a) oferecer aos alunos do curso de graduação em enfermagem da Escola de Enfermagem de Ribeirão Preto da Universidade de São Paulo, uma possibilidade de expressão vivencial da situação peculiar; b) apreender suas condições emocionais relacionadas às suas expectativas; c) identificar aspectos possíveis de serem manejados e; d) sugerir uma possível alternativa de intervenção para alívio de tensões

    Forming a three-dimensional porous organic network via solid-state explosion of organic single crystals

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    Solid-state reaction of organic molecules holds a considerable advantage over liquid-phase processes in the manufacturing industry. However, the research progress in exploring this benefit is largely staggering, which leaves few liquid-phase systems to work with. Here, we show a synthetic protocol for the formation of a three-dimensional porous organic network via solid-state explosion of organic single crystals. The explosive reaction is realized by the Bergman reaction (cycloaromatization) of three enediyne groups on 2,3,6,7,14,15-hexaethynyl-9,10-dihydro-9,10-[1,2]benzenoanthracene. The origin of the explosion is systematically studied using single-crystal X-ray diffraction and differential scanning calorimetry, along with high-speed camera and density functional theory calculations. The results suggest that the solid-state explosion is triggered by an abrupt change in lattice energy induced by release of primer molecules in the 2,3,6,7,14,15-hexaethynyl-9,10-dihydro-9,10-[1,2]benzenoanthracene crystal lattice

    Low prevalence of H. pylori Infection in HIV-Positive Patients in the Northeast of Brazil

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    <p>Abstract</p> <p>Background</p> <p>This study conducted in Northeastern Brazil, evaluated the prevalence of <it>H. pylori </it>infection and the presence of gastritis in HIV-infected patients.</p> <p>Methods</p> <p>There were included 113 HIV-positive and 141 age-matched HIV-negative patients, who underwent upper gastrointestinal endoscopy for dyspeptic symptoms. <it>H. pylori </it>status was evaluated by urease test and histology.</p> <p>Results</p> <p>The prevalence of <it>H. pylori </it>infection was significantly lower (p < 0.001) in HIV-infected (37.2%) than in uninfected (75.2%) patients. There were no significant differences between <it>H. pylori </it>status and gender, age, HIV viral load, antiretroviral therapy and the use of antibiotics. A lower prevalence of <it>H. pylori </it>was observed among patients with T CD4 cell count below 200/mm<sup>3</sup>; however, it was not significant. Chronic active antral gastritis was observed in 87.6% of the HIV-infected patients and in 780.4% of the control group (p = 0.11). <it>H. pylori </it>infection was significantly associated with chronic active gastritis in the antrum in both groups, but it was not associated with corpus chronic active gastritis in the HIV-infected patients.</p> <p>Conclusion</p> <p>We demonstrated that the prevalence of <it>H. pylori </it>was significantly lower in HIV-positive patients compared with HIV-negative ones. However, corpus gastritis was frequently observed in the HIV-positive patients, pointing to different mechanisms than <it>H. pylori </it>infection in the genesis of the lesion.</p
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