The Impact of Low-Level Benzalkonium Chloride Exposure on Staphylococcus spp. Strains and Control by Photoinactivation.

Exposure of bacteria to low concentrations of biocides can facilitate horizontal gene transfer, which may lead to bacterial adaptive responses and resistance to antimicrobial agents. The emergence of antibacterial resistance not only poses a significant concern to the dairy industry but also adds to the complexity and cost of mastitis treatment. This study was aimed to evaluate how selective stress induced by benzalkonium chloride (BC) promotes antibiotic non-susceptibility in Staphylococcus spp. In addition, we investigated the efficacy of photodynamic inactivation (PDI) in both resistant and susceptible strains. The study determined the minimum inhibitory concentration (MIC) of BC using the broth microdilution method for different Staphylococcus strains. The experiments involved pairing strains carrying the qacA/qacC resistance genes with susceptible strains and exposing them to subinhibitory concentrations of BC for 72 h. The recovered isolates were tested for MIC BC and subjected to disc diffusion tests to assess changes in susceptibility patterns. The results demonstrated that subinhibitory concentrations of BC could select strains with reduced susceptibility and antibiotic resistance, particularly in the presence of S. pasteuri. The results of PDI mediated by toluidine blue (100 µM) followed by 60 min irradiation (total light dose of 2.5 J/cm2) were highly effective, showing complete inactivation for some bacterial strains and a reduction of up to 5 logs in others.

Hydrogen sulfide decreases photodynamic therapy outcome through the modulation of the cellular redox state.

Photodynamic therapy (PDT) is a non-surgical treatment that has been approved for its human medical use in many cancers. PDT involves the interaction of a photosensitizer (PS) with light. The amino acid 5- aminolevulinic acid (ALA) can be used as a pro-PS, leading to the synthesis of Protoporphyrin IX. Hydrogen sulfide (H2S) is an endogenously produced gas that belongs to the gasotransmitter family, which can diffuse through biological membranes and have relevant physiological effects such as cardiovascular functions, vasodilatation, inflammation, cell cycle and neuro-modulation. It was also proposed to have cytoprotective effects. We aimed to study the modulatory effects of H2S on ALAPDT in the mammary adenocarcinoma cell line LM2. Exposure of the cells to NaHS (donor of H2S) in concentrations up to 10 mM impaired the response to ALA-PDT in a dose-dependent manner. The addition of 3 doses of NaHS showed the highest effect. This decreased response to the photodynamic treatment was correlated to an increase in the GSH levels, catalase activity, a dose dependent reduction of PpIX and increased intracellular ALA, decreased levels of oxidized proteins and a decrease of PDT-induced ROS. NaHS also reduced the levels of singlet oxygen in an in vitro assay. H2S also protected other cells of different origins against PDT mediated by ALA and other PSs. These results suggest that H2S has a role in the modulation of the redox state of the cells, and thus impairs the response to ALA-PDT through multifactor pathways. These findings could contribute to developing new strategies to improve the effectiveness of PDT particularly mediated by ALA or other ROS-related treatments.

Synthesis and cytotoxicity evaluation of olivacine-indole hybrids tethered by alkyl linkers.

In this work, eleven new derivatives were prepared of the alkaloid olivacine (1), which was isolated from the bark of Aspidosperma australe. These compounds (7a-k) are hybrids of olivacine and indoles or carbazole, tethered by alkyl chains of variable lengths (C-4, C-5 or C-6). Compounds 7a-k showed increased cytotoxicity towards a panel of four cell lines. The subcellular localization of olivacine and of the synthetic derivatives was studied by fluorescence microscopy. The cycles of K562 cells exposed to olivacine or compounds 7a-k were analysed by flow cytometry, and showed, for some of the new derivatives, a different profile of cell distribution among the phases of the cycle when compared to olivacine, which is indicative of lysosomal apoptosis.

Photosensitization of a subcutaneous tumour by the natural anthraquinone parietin and blue light.

Photodynamic therapy (PDT) is an anticancer treatment involving administration of a tumour-localizing photosensitizer, followed by activation by light of a suitable wavelength. In previous work, we showed that the natural anthraquinone (AQ) Parietin (PTN), was a promising photosensitizer for photodynamic therapy of leukemic cells in vitro. The present work aimed to analyze the photosensitizing ability of PTN in the mammary carcinoma LM2 cells in vitro and in vivo in a model of subcutaneously implanted tumours. Photodynamic therapy mediated by parietin (PTN-PDT) (PTN 30 µM, 1 h and 1.78 J/cm2 of blue light) impaired cell growth and migration of LM2 cells in vitro. PTN per se induced a significant decrease in cell migration, and it was even more marked after illumination (migration index was 0.65 for PTN and 0.30 for PTN-PDT, *p < 0.0001, ANOVA test followed by Tukey's multiple comparisons test), suggesting that both PTN and PTN-PDT would be potential inhibitors of metastasis. Fluorescence microscopy observation indicated cytoplasmic localization of the AQ and no fluorescence at all was recorded in the nuclei. When PTN (1.96 mg) dissolved in dimethyl sulfoxide was topically applied on the skin of mice subcutaneously implanted with LM2 cells, PTN orange fluorescence was strongly noticed in the stratum corneum and also in the inner layers of the tumour up to approximately 5 mm. After illumination with 12.74 J/cm2 of blue light, one PDT dose at day 1, induced a significant tumour growth delay at day 3, which was not maintained in time. Therefore, we administered a second PTN-PDT boost on day 3. Under these conditions, the delay of tumour growth was 28% both on days 3 and 4 of the experiment (*p < 0.05 control vs. PTN-PDT, two-way ANOVA, followed by Sidak's multiple comparisons test). Histology of tumours revealed massive tumour necrosis up to 4 mm of depth. Intriguingly, a superficial area of viable tumour in the 1 mm superficial area, and a quite conserved intact skin was evidenced. We hypothesize that this may be due to PTN aggregation in contact with the skin and tumour milieu of the most superficial tumour layers, thus avoiding its photochemical properties. On the other hand, normal skin treated with PTN-PDT exhibited slight histological changes. These preliminary findings encourage further studies of natural AQs administered in different vehicles, for topical treatment of cutaneous malignancies.

Novel meso-substituted porphyrin derivatives and its potential use in photodynamic therapy of cancer.

BACKGROUND: Photodynamic therapy (PDT) is an anticancer treatment that utilizes the interaction of light and a photosensitiser (PS), promoting tumour cell death mediated by generation of reactive oxygen species. In this study, we evaluated the in vitro photoactivity of four meso-substituted porphyrins and a porphyrin coupled to a fullerene. METHODS: The cell line employed was the LM3 mammary adenocarcinoma, and the PS with the best photokilling activity was administered to mice bearing the LM3 subcutaneously implanted adenocarcinoma. The TEMCP4+ porphyrin and its analogue TEMCC4+ chlorine contain four identical carbazoyl substituents at the meso positions of the tetrapyrrolic macrocycle and have A4 symmetry. The TAPP derivative also has A4 symmetry, and it is substituted at the meso positions by aminopropoxy groups. The DAPP molecule has ABAB symmetry with aminopropoxy and the trifluoromethyl substituents in trans positions. The TCP-C604+ dyad is formed by a porphyrin unit covalently attached to the fullerene C60. RESULTS: The PSs are taken up by the cells with the following efficiency: TAPP> TEMCP4+ = TEMCC4+ > DAPP >TCP-C604+, and the amount of intracellular PS correlates fairly with the photodamage degree, but also the quantum yields of singlet oxygen influence the PDT outcome. TAPP, DAPP, TEMCC4+ and TEMCP4+ exhibit high photoactivity against LM3 mammary carcinoma cells, being TAPP the most active. After topical application of TAPP on the skin of mice bearing LM3 tumours, the molecule is localized mainly in the stratum corneum, and at a lower extent in hair follicles and sebaceous glands. Systemic administration of TAPP produces a tumour: normal skin ratio of 31.4, and high accumulation in intestine and lung. CONCLUSION: The results suggest a potential use of topical TAPP for the treatment of actinic keratosis and skin adnexal neoplasms. In addition, selectivity for tumour tissue after systemic administration highlights the selectivity of and potentiality of TAPP as a new PS.

Apoptotic cell death induced by dendritic derivatives of aminolevulinic acid in endothelial and foam cells co-cultures.

Photodynamic therapy (PDT) is an effective procedure for the treatment of lesions diseases based on the selectivity of a photosensitising compound with the ability to accumulate in the target cell. Atherosclerotic plaque is a suitable target for PDT because of the preferential accumulation of photosensitisers in atherosclerotic plaques. Dendrimers are hyperbranched polymers conjugated to drugs. The dendrimers of ALA hold ester bonds that inside the cells are cleaved and release ALA, yielding PpIX production. The dendrimer 6m-ALA was chosen to perform this study since in previous studies it induced the highest porphyrin macrophage: endothelial cell ratio (Rodriguez et al. in Photochem Photobiol Sci 14:1617-1627, 2015). We transformed Raw 264.7 macrophages to foam cells by exposure to oxidised LDLs, and we employed a co-culture model of HMEC-1 endothelial cells and foam cells to study the affinity of ALA dendrimers for the foam cells. In this work it was proposed an in vitro model of atheromatous plaque, the aim was to study the selectivity of an ALA dendrimer for the foam cells as compared to the endothelial cells in a co-culture system and the type of cell death triggered by the photodynamic treatment. The ALA dendrimer 6m-ALA showed selectivity PDT response for foam cells against endothelial cells. A light dose of 1 J/cm2 eliminate foam cells, whereas less than 50% of HMEC-1 is killed, and apoptosis cell death is involved in this process, and no necrosis is present. We propose the use of ALA dendrimers as pro-photosensitisers to be employed in photoangioplasty to aid in the treatment of obstructive cardiovascular diseases, and these molecules can also be employed as a theranostic agent.

Evaluación formativa con los estudiantes en prácticas, para reducir la brecha teoría-práctica en la formación inicial del profesorado / Formative Assessment with Students in Practice, to Reduce the Theoretical-Practical Gap in Initial Teacher Training / Avaliação formativa com os alunos na prática, para reduzir a lacuna teórico-prática na formação inicial de professores

Entre los docentes en formación inicial, hoy en día existe una apreciación generalizada respecto a que hay una brecha demasiado amplia entre los conocimientos teóricos que se transmiten en el aula universitaria, y la práctica real a la que se enfrenta el docente en sus primeros acercamientos al aula escolar. En España, los planes de estudio universitarios orientados a la formación inicial del profesorado, permiten al docente tomar contacto con la realidad educativa a través de la asignatura del Prácticum. No obstante, es justamente en este proceso de prácticas donde el alumnado puede experimentar ese abismo entre teoría y práctica. En el presente artículo, se plantea la evaluación formativa como un medio idóneo y necesario para unir lo aprendido en el aula universitaria, con las demandas diarias que acontecen en el ámbito escolar.

There is today among teachers in initial training a generalized appreciation of the existence of too wide a gap between the theoretical knowledge transmitted in the university classroom and the actual practice faced by teachers in their first approaches to the school classroom. In Spain, university study plans aimed at initial teacher training allow teachers to contact educational reality through the Practicum course. However, it is precisely in this process of practice where students can experience the existence of a gap between theory and practice. In this article, the formative assessment is presented as an ideal and necessary means to unite what has been learned in the university classroom with the daily demands existing in the school environment.

Há hoje entre os professores em formação inicial uma apreciação generalizada da existência de uma lacuna muito grande entre o conhecimento teórico transmitido na sala de aula da universidade e a prática real enfrentada pelos professores em suas primeiras aproximações à sala de aula da escola. Currículos universitários em Espanha, visando à formação inicial dos professores permitem que eles possam entrar em contato com a realidade educativa através da disciplina nomeada Prácticum. Contudo, é precisamente no estágio que os alunos podem experimentar a existência de uma lacuna entre a teoria e a prática. Neste artigo, a avaliação formativa é apresentada como um instrumento ideal e necessário para unir o que foi aprendido na sala de aula universitária com as demandas diárias existentes no ambiente escolar.

¿por qué quiero ser profesor de educación física? análisis del cambio de percepción durante la formación universitaria y los primeros años de la carrera docente / Por que é que eu quero ser professor de educação física? análise da mudança na percepção durante a formação universitária e anos iniciais da carreira docente / Why do i want to be a physical education teacher? analysis of the change in perception during university education and early years of teaching career

Resumen: El presente estudio tiene dos objetivos: a) analizar la evolución de la percepción de futuros maestros EF de primer, cuarto curso de carrera y egresados; b) contrastar la realidad profesional del maestro de EF con la valoración de profesores universitarios de EF. Participaron 10 estudiantes en un diseño longitudinal de seis años, dividido en tres fases (2012, 2015 y 2017). También participaron ocho docentes universitarios. Se utilizó un enfoque cualitativo con dos instrumentos de recogida de datos y se establecieron tres categorías de análisis. Los resultados mostraron cómo, en primer curso, los estudiantes dudan sobre qué es ser docente en EF, mientras que en cuarto curso muestran desmotivación respecto a la posibilidad de serlo. Por su parte, los egresados reflejan la incoherencia existente entre la formación universitaria recibida y la exigencia del sistema de acceso a la función pública, cuestión sobre la que los profesores universitarios no muestran concordancia.

Resumo: O presente estudo tem dois objetivos: a) analisar a evolução da percepção dos futuros professores de EF do primeiro, quarto ano de carreira e graduados; b) contrastar a realidade profissional do professor de EF com a avaliação dos professores universitários de EF. Dez alunos participaram de um projeto longitudinal de seis anos, dividido em três fases (2012, 2015 e 2017). Oito professores universitários também participaram. Foi utilizada uma abordagem qualitativa com dois instrumentos de recolha de dados e foram estabelecidas três categorias de análise. Os resultados mostraram como, no primeiro ano, os alunos duvidam do que é ser professor na EF, enquanto no quarto ano mostram falta de motivação em relação à possibilidade de se tornar um. Por outro lado, os graduados refletem a incoerência existente entre a formação universitária recebida e a exigência do sistema de acesso ao serviço público, uma questão sobre a qual os professores universitários não concordam.

Abstract: The present study has two objectives: a) to analyse the evolution of the perception of future EF teachers of first, fourth year of career and graduates; b) to contrast the professional reality of the EF teacher with the assessment of EF university professors. Ten students participated in a six-year longitudinal design, divided into three phases (2012, 2015 and 2017). Eight university professors also participated. A qualitative approach was used with two data collection instruments. The results showed how, in the first year, students doubt what it is like to be a teacher in EF, while in the fourth year they show a lack of motivation regarding the possibility of becoming one. On the other hand, the graduates reflect the incoherence existing between the university training received and the requirement of the system of access to the public service, an issue on which the university professors do not agree.

Disaccharides obtained from carrageenans as potential antitumor agents.

Carrageenans are sulfated galactans found in certain red seaweeds with proven biological activities. In this work, we have prepared purified native and degraded κ-, ι-; and λ-carrageenans, including the disaccharides (carrabioses) and disaccharide-alditols (carrabiitols) from seaweed extracts as potential antitumor compounds and identified the active principle of the cytotoxic and potential antitumor properties of these compounds. Both κ and ι-carrageenan, as well as carrageenan oligosaccharides showed cytotoxic effect over LM2 tumor cells. Characterized disaccharides (carrabioses) and the reduced product carrabiitols, were also tested. Only carrabioses were cytotoxic, and among them, κ-carrabiose was the most effective, showing high cytotoxic properties, killing the cells through an apoptotic pathway. In addition, the cells surviving treatment with κ-carrabiose, showed a decreased metastatic ability in vitro, together with a decreased cell-cell and cell-matrix interactions, thus suggesting possible antitumor potential. Overall, our results indicate that most cytotoxic compounds derived from carrageenans have lower molecular weights and sulfate content. Potential applications of the results emerging from the present work include the use of disaccharide units such as carrabioses coupled to antineoplasics in order to improve its cytotoxicity and antimetastatic properties, and the use of ι-carrageenan as adjuvant or carrier in anticancer treatments.

La foto-elicitación como instrumento para profundizar en la construcción de las subjetividades corporales de maestros de educación física en formación / A foto-elicitação como um instrumento para aprofundar a construção das subjetividades corporais de professores de educação física em formação / Photo-elicitation as a tool to look into bodily subjectivities of physical education students

El objetivo del presente estudio fue conocer la influencia que tienen los medios de comunicación en la construcción de las subjetividades corporales de futuros docentes de Educación Física (EF). Participaron ocho futuros maestros (cinco hombres y tres mujeres). Se empleó la foto-elicitación como técnica de análisis y las entrevistas como instrumentos de recogida de datos. Los resultados reflejaron cómo la manera de concebir la materia de EF está claramente condicionada por el prototipo de cuerpo que tenga el docente. Es el musculado en hombres y el esbelto y definido en mujeres el más valorado, algo que se asocia con el modelo ideal ensalzado en los medios de comunicación. Reconocen que el cuerpo es su herramienta de trabajo y su tarjeta de presentación hacia los demás. Se destaca la importancia de analizar el cuerpo desde un enfoque pedagógico que se vincule a la creación de identidad profesional de los futuros docentes

O objetivo do presente estudo foi conhecer a influência que a mídia tem sobre a construção das subjetividades corporais dos futuros professores de Educação Física (EF). Participaram oito futuros professores (cinco homens e três mulheres). A foto-elicitação foi utilizada como técnica de análise e as entrevistas foram usadas como instrumentos de coleta de dados. Os resultados refletiram como a maneira de conceber o assunto da EF é claramente condicionada pelo protótipo do corpo do professor. É o músculo nos homens e o delgado e definido nas mulheres o mais valorizado, algo que está associado ao modelo ideal exaltado na mídia. Eles reconhecem que o corpo é sua ferramenta de trabalho e sua maneira de se apresentar a outros. Enfatizamos a importância de analisar o corpo a partir de uma abordagem pedagógica ligada à criação da identidade profissional dos futuros professores

This study was aimed at knowing the media's influence on the construction of future Physical Education (PE) teachers' bodily subjectivities. Participants were eight future teachers (five male and three female). Photo-elicitation was used for analysis and interviews were used as data collection instruments. The results reflected how PE conceptions are clearly conditioned by teachers' body prototypes. The most valued ones are muscular for men and slender and well-defined for women ­ something that is associated with the ideal model promoted by the media. They recognize that their bodies are their work tools and their ways to introduce themselves to others. We stress the importance of analyzing the body under a pedagogical approach linked to the creation of future teachers' professional identities

Reversal of the Migratory and Invasive Phenotype of Ras-Transfected Mammary Cells by Photodynamic Therapy Treatment.

Photodynamic therapy (PDT) is a non-thermal technique for inducing tumor damage following administration of a light-activated photosensitizing drug (PS). In a previous work we found that PDT induces cytoskeleton changes in HB4a-Ras cells (human mammary breast carcinoma HB4a cells transfected with the RAS oncogene). In the present work we have studied the migratory and invasive features and the expression of proteins related to these processes on HB4a-Ras cells after three successive cycles of PDT using different PSs: 5-aminolevulinic acid (ALA), Verteporfin (Verte), m-tetrahydroxyphenylchlorin (m-THPC), and Merocyanine 540 (MC). A slight (1.25- to 2-fold) degree of resistance was acquired in cell populations subjected to the three successive PDT treatments. However, complete cell killing was achieved after a light dose increase. Regardless of the PS employed, all the PDT-treated populations had shorter stress fibres than the untreated control HB4a-Ras cells, and the number of dorsal stress fibres was decreased in the PDT-treated populations. E-Cadherin distribution, which was already aberrant in HB4a-Ras cells, became even more diffuse in the PDT-treated populations, though its expression was increased in some of them. The strong migratory and invasive ability of HB4a-Ras cells in vitro was impaired in all the PDT-treated populations, with a behavior that was similar to the parental non-tumoral HB4a cells. MMP-2 and -9 metalloproteinase activities were also impaired in the PDT-treated populations. The evidence presented herein suggests that the cells surviving PDT would be less metastatic than the initial population. These findings encourage the use of PDT in combination with other treatments such as intraoperative or post-surgery therapeutic procedures. J. Cell. Biochem. 118: 464-477, 2017. © 2016 Wiley Periodicals, Inc.

Estudiando el proceso de configuración de multiscopic, una red on-line profesional de análisis de la práctica de educación física / Estudar o processo de configuração de multiscopic, uma análise profissional da rede on-line da prática da educação física / Studying the configuration process of multiscopic, a professional online network that analyses the physical education practice

Presentamos aquí algunos de los primeros resultados sobre el desarrollo de una red profesional en línea llamada MultiScopic (múltiples puntos de vista sobre un fenómeno), tratando de entender cuáles son las tensiones y limitaciones en torno al proceso de consolidación de una comunidad on-line de análisis de la práctica educativa. En este sentido, MultiScopic es una red social que involucra, entre otros, a maestros y profesores de Educación Física en activo y que ofrece un espacio, a través del intercambio, del diálogo, de la aplicación, reflexión y evaluación de diferentes prácticas pedagógicas, para compartir diferentes puntos de vista, intercambiar procedimientos de análisis y llevar a cabo una formación permanente reflexiva capaz de mejorar los procesos de enseñanza/aprendizaje. A la vista de los primeros resultados, concluimos que este proyecto permite generar significados compartidos en torno a la Educación Física y dotar al profesorado de procedimientos para el análisis y mejora de su práctica.

Apresentamos aqui alguns dos primeiros resultados sobre o desenvolvimento de uma rede profissional online chamada MultiScopic (múltiplos pontos de vista sobre um fenômeno), tentando entender quais são as tensões e limitações ao redor do processo de consolidação de uma comunidade online de análise da prática educativa. Nesse sentido, MultiScopic é uma rede social que envolve, entre outros, professores formados ou não em Educação Física, ativos e que oferece um espaço, através do intercâmbio, do diálogo, da aplicação, reflexão e avaliação de diferentes práticas pedagógicas, para dividir diferentes pontos de vista, intercambiar procedimentos de análise e levar a cabo uma formação permanente reflexiva capaz de melhorar os processos de ensino/aprendizagem. Tendo em vista os primeiros resultados, concluímos que esse projeto permite gerar significados compartilhados em torno da Educação Física e dotar o profesorado de procedimentos para a análise e melhora das suas práticas.

This article presents some of the initial results on the development of a professional online network called MultiScopic (multiple points of view of a phenomenon), in an attempt to understand what are the tensions and limitations surrounding the process of consolidation of an online analysis community in the educational practice. From this standpoint, MultiScopic is a social network that involves, among others, teachers and active Physical Educators and offers a space, through exchange, dialog, application, reflection and evaluation of different pedagogical practices, to share different points of view, exchange analysis procedures, and carry out a permanent reflexive formation, capable of improving the teaching-learning process. In light of the initial results, it can be concluded that this project generates shared meanings around Physical Education and provides educators with procedures for the analysis and the improvement their practice.