18 research outputs found

    Approaches in biotechnological applications of natural polymers

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    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)

    Estudio funcional de los polimorfismos del promotor del gen de la esclerostina

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    La esclerostina, codificada por el gen SOST, es un inhibidor de la vía Wnt, y por ello tiene una influencia negativa sobre la masa ósea. Algunos polimorfismos del promotor de SOST se han asociado a diferencias en la densidad mineral ósea (DMO) en varios estudios, pero se desconocen cuáles son los mecanismos moleculares implicados. El objetivo de este estudio fue comprobar las consecuencias funcionales de uno de esos polimorfismos in vitro. Para ello se clonó la región promotora proximal del gen SOST, con diferentes alelos del polimorfismo rs851054, y se transfectaron en células HEK-293T, SAOS-2 y HOS-TE85. En ningún caso se observaron diferencias significativas en la actividad transcripcional entre los vectores con el alelo A y los vectores con el alelo G. La co-transfección de vectores de expresión de los factores de transcripción RUNX2 y OSX estimuló claramente la actividad transcripcional (2,5±0,9 veces sobre el valor basal para el alelo A y 1,9±0,8 veces para el alelo G; en ambos casos, p<0,05), sin que hubiera, sin embargo, diferencias entre los alelos. Tampoco se hallaron diferencias en la fijación a proteínas nucleares analizadas en experimentos de retardo de la movilidad electroforética. En conclusión, la región situada antes del inicio de la traducción del gen SOST tiene una potente actividad promotora, que es aumentada por los factores RUNX2 y OSX. Las variantes frecuentes de esta región se han asociado con la DMO, pero los mecanismos implicados son aún desconocidos, puesto que los alelos analizados no muestran diferencias en la actividad transcripcional in vitro

    Polypharmacy Patterns: Unravelling Systematic Associations between Prescribed Medications

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    OBJECTIVES: The aim of this study was to demonstrate the existence of systematic associations in drug prescription that lead to the establishment of patterns of polypharmacy, and the clinical interpretation of the associations found in each pattern. METHODS: A cross-sectional study was conducted based on information obtained from electronic medical records and the primary care pharmacy database in 2008. An exploratory factor analysis of drug dispensing information regarding 79,089 adult patients was performed to identify the patterns of polypharmacy. The analysis was stratified by age and sex. RESULTS: Seven patterns of polypharmacy were identified, which may be classified depending on the type of disease they are intended to treat: cardiovascular, depression-anxiety, acute respiratory infection (ARI), chronic obstructive pulmonary disease (COPD), rhinitis-asthma, pain, and menopause. Some of these patterns revealed a clear clinical consistency and included drugs that are prescribed together for the same clinical indication (i.e., ARI and COPD patterns). Other patterns were more complex but also clinically consistent: in the cardiovascular pattern, drugs for the treatment of known risk factors—such as hypertension or dyslipidemia—were combined with other medications for the treatment of diabetes or established cardiovascular pathology (e.g., antiplatelet agents). Almost all of the patterns included drugs for preventing or treating potential side effects of other drugs in the same pattern. CONCLUSIONS: The present study demonstrated the existence of non-random associations in drug prescription, resulting in patterns of polypharmacy that are sound from the pharmacological and clinical viewpoints and that exist in a significant proportion of the population. This finding necessitates future longitudinal studies to confirm some of the proposed causal associations. The information discovered would further the development and/or adaptation of clinical patient guidelines to patients with multimorbidity who are taking multiple drugs

    Strategies at Bioreactor Scale for the Production of Recombinant Proteins in Yarrowia lipolytica

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    Recombinant protein production represents a multibillion-dollar market. Therefore, it constitutes an important research field both in academia and industry. The use of yeast as cell factory presents several advantages such as ease of genetic manipulation, growth at high cell density, and possibility of posttranslational modifications. Yarrowia lipolytica is considered as one of the most attractive hosts due to its ability to metabolize raw substrate, to express genes at high level, and to secrete protein in large amounts. In the recent years, several reviews were dedicated to genetic tools developed for this purpose. Although the construction of efficient cell factory for recombinant protein synthesis is important, the development of an efficient process for protein production constitutes an equally vital aspect. Indeed, a sports car could not drive fast on a gravel road. The aim of this review is to provide a comprehensive snapshot of process tools to consider for recombinant protein production in bioreactor using Y. lipolytica as a cell factory, in order to facilitate the decision-making for future strain and process engineering
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