Photodynamic Antimicrobial Chemotherapy in Aquaculture: Photoinactivation Studies of Vibrio fischeri

BACKGROUND: Photodynamic antimicrobial chemotherapy (PACT) combines light, a light-absorbing molecule that initiates a photochemical or photophysical reaction, and oxygen. The combined action of these three components originates reactive oxygen species that lead to microorganisms' destruction. The aim was to evaluate the efficiency of PACT on Vibrio fischeri: 1) with buffer solution, varying temperature, pH, salinity and oxygen concentration values; 2) with aquaculture water, to reproduce photoinactivation (PI) conditions in situ. METHODOLOGY/PRINCIPAL FINDINGS: To monitor the PI kinetics, the bioluminescence of V. fischeri was measured during the experiments. A tricationic meso-substituted porphyrin (Tri-Py(+)-Me-PF) was used as photosensitizer (5 µM in the studies with buffer solution and 10-50 µM in the studies with aquaculture water); artificial white light (4 mW cm(-2)) and solar irradiation (40 mW cm(-2)) were used as light sources; and the bacterial concentration used for all experiments was ≈10(7) CFU mL(-1) (corresponding to a bioluminescence level of 10(5) relative light units--RLU). The variations in pH (6.5-8.5), temperature (10-25°C), salinity (20-40 g L(-1)) and oxygen concentration did not significantly affect the PI of V. fischeri, once in all tested conditions the bioluminescent signal decreased to the detection limit of the method (≈7 log reduction). The assays using aquaculture water showed that the efficiency of the process is affected by the suspended matter. Total PI of V. fischeri in aquaculture water was achieved under solar light in the presence of 20 µM of Tri-Py(+)-Me-PF. CONCLUSIONS/SIGNIFICANCE: If PACT is to be used in environmental applications, the matrix containing target microbial communities should be previously characterized in order to establish an efficient protocol having into account the photosensitizer concentration, the light source and the total light dose delivered. The possibility of using solar light in PACT to treat aquaculture water makes this technology cost-effective and attractive

Markers of vulnerability for cervical cancer in HIV-infected women

This study identifies the dimensions and markers of vulnerability among women infected with HIV regarding the development of cervical cancer. A total of 76 HIV-infected women cared for in Fortaleza, CE, Brazil from October 2007 to June 2008 participated in the study. Semi-structured interviews were used to collect socio-demographic, clinical, and sexual data, as well as situations related to health care follow-up and the prevention of cervical cancer. Identified situations were grouped according to the dimensions and markers of vulnerability. HIV-infected women experience different situations linked to individual, programmatic and social dimensions that leave them vulnerable to the development of cervical cancer. The conclusion is that this population is vulnerable to cervical cancer and specific preventive actions are necessary to supply information associated with early detection, improve knowledge, encourage self-care, and improve the quality of health services directed to this population.Se objetivó identificar las dimensiones y los marcadores de vulnerabilidad entre mujeres infectadas por el HIV, en el caso del desarrollo del cáncer cérvico uterino. Participaron 76 mujeres, infectadas por el HIV, de octubre de 2007 a junio de 2008, atendidas en Fortaleza, estado de Ceará, en Brasil. La entrevista semiestructurada propició evaluar datos sociodemográficos, clínicos, sexuales y situaciones relacionadas al seguimiento en salud y a la prevención contra cáncer cérvico uterino. Los datos posibilitaron el agrupamiento de situaciones indicadas en las dimensiones y marcadores de vulnerabilidad. Las mujeres infectadas por el HIV presentan diferentes situaciones que las tornan vulnerables al desarrollo del cáncer de cuello uterino, ligadas a las dimensiones individual, programática y social. Se concluye que esta población es vulnerable al cáncer de cuello uterino y que son necesarias acciones preventivas específicas, para ofrecer informaciones asociadas a la detección precoz de la enfermedad, mejorar el nivel de conocimiento, estimular el autocuidado y mejorar la calidad de los servicios de salud destinados a esa clientela.Objetivou-se identificar as dimensões e os marcadores de vulnerabilidade entre mulheres infectadas pelo HIV, para o desenvolvimento do câncer cérvico-uterino. Participaram 76 mulheres, infectadas pelo HIV, de outubro de 2007 a junho de 2008, atendidas em Fortaleza, CE, Brasil. Entrevista semiestruturada propiciou avaliar dados sociodemográficos, clínicos, sexuais e situações relacionadas ao seguimento em saúde e à prevenção contra câncer cérvico-uterino. Os dados possibilitaram o agrupamento de situações indicadas nas dimensões e marcadores de vulnerabilidade. As mulheres infectadas pelo HIV possuem diferentes situações que as tornam vulneráveis ao desenvolvimento do câncer de colo uterino, ligadas às dimensões individual, programática e social. Conclui-se ser essa população vulnerável ao câncer de colo do útero e serem necessárias ações preventivas específicas, para fornecer informações associadas à detecção precoce da doença, melhoria do nível de conhecimento, estímulo ao autocuidado e melhoria da qualidade dos serviços de saúde destinados a essa clientela

Cerebral gene expression in response to single or combined gestational exposure to methylmercury and selenium through the maternal diet

Controversy remains regarding the safety of consuming certain types of seafood, particularly during pregnancy. While seafood is rich in vital nutrients, it may also be an important source of environmental contaminants such as methylmercury (MeHg). Selenium (Se) is one essential element present in seafood, hypothesised to ameliorate MeHg toxicity. The aim of the present study was to ascertain the impact of Se on MeHg-induced cerebral gene expression in a mammalian model. Microarray analysis was performed on brain tissue from 15-day-old mice that had been exposed to MeHg throughout development via the maternal diet. The results from the microarray analysis were validated using qPCR. The exposure groups included: MeHg alone (2.6 mg kg−1), Se alone (1.3 mg kg−1), and MeHg + Se. MeHg was presented in a cysteinate form, and Se as Se–methionine, one of the elemental species occurring naturally in seafood. Eight genes responded to Se exposure alone, five were specific to MeHg, and 63 were regulated under the concurrent exposure of MeHg and Se. Significantly enriched functional classes relating to the immune system and cell adhesion were identified, highlighting potential ameliorating mechanisms of Se on MeHg toxicity. Key developmental genes, such as Wnt3 and Sparcl1, were also identified as putative ameliorative targets. This study, utilising environmentally realistic forms of toxicants, delivered through the natural route of exposure, in association with the power of transcriptomics, highlights significant novel information regarding putative pathways of selenium and MeHg interaction in the mammalian brain

Pollen-ovule relation in Adesmia tristis and reflections on the seed–ovule ratio by interaction with pollinators in two vertical strata

The vertical distribution of pollinators is an important component in the foraging pattern of plants strata, and it influences the reproductive system (pollen/ovule ratio) and seed/ovule ratio. Niches in two different strata from Adesmia tristis Vogel were evaluated in these aspects. This plant is an endemic shrub from the Campos de Cima da Serra in Southern Brazil. The studies were carried out from January 2010, to January 2011, at Pró-Mata/PUCRS (Catholic University of Rio Grande do Sul) (29°27'-29°35'S and 50°08'-50°15'W), São Francisco de Paula, sate of Rio Grande do Sul, Brazil. Breeding system of A. tristis is mandatory allogamy. The vertical profile in A. tristis has differentiated foraging niches among the most common pollinators. Bees of Megachile genus forage in the upper stratum, and representative bees of the Andrenidae family explore the lower stratum. The upper stratum of the vertical profile had more contribution to seed production. Adesmia tristis showed evidence of pollination deficitA distribuição vertical dos polinizadores é um importante componente no padrão de forrageamento nos estratos das plantas e influencia o sistema reprodutivo (relação pólen/ óvulo) e a razão semente/óvulo. Nichos em dois estratos diferentes de Adesmia tristis Vogel foram avaliados quanto a esses aspectos. Essa planta é um arbusto endêmico dos campos de Cima da Serra no Sul do Brasil. Os estudos ocorreram de janeiro de 2010 a janeiro de 2011, no Pró- Mata/PUCRS (Pontifícia Universidade Católica do Rio Grande do Sul) (29°27'-29°35'S e 50°08'-50°15'W), São Francisco de Paula, estado do Rio Grande do Sul, Brasil. O sistema reprodutivo de A. tristis é alogamia obrigatória. O perfil vertical em A. tristis possui diferentes nichos de forrageamento entre os polinizadores mais comuns. Abelhas do gênero Megachile forrageiam no estrato superior e as abelhas representantes da família Andrenidae exploram o estrato inferior. O estrato superior do perfil vertical contribui mais na produção de sementes. Adesmia tristis apresentou evidências de déficit de polinizaçã

Approaches in biotechnological applications of natural polymers

Natural polymers, such as gums and mucilage, are biocompatible, cheap, easily available and non-toxic materials of native origin. These polymers are increasingly preferred over synthetic materials for industrial applications due to their intrinsic properties, as well as they are considered alternative sources of raw materials since they present characteristics of sustainability, biodegradability and biosafety. As definition, gums and mucilages are polysaccharides or complex carbohydrates consisting of one or more monosaccharides or their derivatives linked in bewildering variety of linkages and structures. Natural gums are considered polysaccharides naturally occurring in varieties of plant seeds and exudates, tree or shrub exudates, seaweed extracts, fungi, bacteria, and animal sources. Water-soluble gums, also known as hydrocolloids, are considered exudates and are pathological products; therefore, they do not form a part of cell wall. On the other hand, mucilages are part of cell and physiological products. It is important to highlight that gums represent the largest amounts of polymer materials derived from plants. Gums have enormously large and broad applications in both food and non-food industries, being commonly used as thickening, binding, emulsifying, suspending, stabilizing agents and matrices for drug release in pharmaceutical and cosmetic industries. In the food industry, their gelling properties and the ability to mold edible films and coatings are extensively studied. The use of gums depends on the intrinsic properties that they provide, often at costs below those of synthetic polymers. For upgrading the value of gums, they are being processed into various forms, including the most recent nanomaterials, for various biotechnological applications. Thus, the main natural polymers including galactomannans, cellulose, chitin, agar, carrageenan, alginate, cashew gum, pectin and starch, in addition to the current researches about them are reviewed in this article.. }To the Conselho Nacional de Desenvolvimento Cientfíico e Tecnológico (CNPq) for fellowships (LCBBC and MGCC) and the Coordenação de Aperfeiçoamento de Pessoal de Nvíel Superior (CAPES) (PBSA). This study was supported by the Portuguese Foundation for Science and Technology (FCT) under the scope of the strategic funding of UID/BIO/04469/2013 unit, the Project RECI/BBB-EBI/0179/2012 (FCOMP-01-0124-FEDER-027462) and COMPETE 2020 (POCI-01-0145-FEDER-006684) (JAT)

Reverse micelles as reaction media for lipases

Reversed micelles are at the present time faced as common organic media to perform biocatalysis. They have been associated to the idea of a microreactor where the enzyme can be sheltered and protected from solvent detrimental effects. This simplistic idea led some investigators to ignore some basic understanding, such as the recognition of the enzyme-specific microenvironment and what the enzyme experiences inside the reversed micelle. To date the number of reactions catalyzed by lipases in reversed micelles is large. This review aims to highlight some of the fundamental aspects of the lipase microencapsulation as well as to resume the outstanding progress of the reversed micellar systems. The properties of the micellar microenvironment are reviewed and related to the lipases' performance both in terms of activity and stability. The heterogeneity of reversed micellar systems is discussed in relation to component distribution models and also to enzymatic kinetics. The new trends and the practical aspects where efforts should be centralized in order to spread out the micellar bioreactor technology over industrial processes are also discussed. (C) 2000 Societe francaise de biochimie et biologie moleculaire / Editions scientifiques et medicales Elsevier SAS