Why biofilms are important in nosocomial infections: the state of the art

As infeções nosocomiais são uma realidade constante no ambiente hospitalar. São responsáveis por um elevado número de casos de infeções e são notoriamente difíceis de erradicar. Um dos motivos pelos quais o tratamento das infeções nosocomiais é difícil deve-se ao facto de muitas destas infeções serem causadas por biofilmes microbianos. Os biofilmes podem ser definidos como comunidades de micro-organismos que vivem aderidos a uma superfície e envoltos numa complexa mistura de compostos tais como proteínas, polissacáridos e DNA extracelular. O crescimento de micro-organismos sob a forma de biofilmes dificulta a sua erradicação, pois estas estruturas podem ser consideradas adaptações dos micro-organismos, de forma a continuar no hospedeiro. É especialmente relevante ter em consideração as infeções causadas por biofilmes no contexto hospitalar, pois podem necessitar de abordagens diferentes para a sua erradicação. Este artigo de revisão tem como objetivo reunir o conhecimento existente do papel dos biofilmes microbianos nas infeções nosocomiais.Nowadays nosocomial infections are a reality in all hospital environments. They are the cause of a high number of infections, morbidity and mortality, and are recognised as being notoriously difficult to eradicate. One of the reasons for the problems in the treatment of nosocomial infection is the fact that many of the pathogens involved in this infections form biofilms. Biofilms are normally defined as communities of microorganisms adhered to a surface and surrounded by a polymeric matrix of extracellular components, such as proteins, polysaccharides and eDNA. The growth of microorganisms in biofilms makes their eradication difficult as this type of growth can be considered an adaptation of the pathogens in order to improve their persistence in the host. As such it is of special interest to account for the role of biofilms in nosocomial infections so that the appropriate approach can be taken in order to eradicate them. The aim of this article is to review the existing information on the prevalence of nosocomial infections potentially caused by biofilms(undefined

Systematic review of N-acetylcysteine in the treatment of addictions

Objective: To conduct the first systematic literature review of clinical trials of N-acetylcysteine (NAC) for the treatment of substance abuse disorders and addictive behaviors. Methods: A search of the MEDLINE, Embase and PsycINFO databases was conducted. The inclusion criteria for the review were clinical trials that used NAC in the treatment of a disorder related to substance use and/or addictive behaviors, limited to texts in English, Spanish, or French. The selected studies were evaluated with respect to type of trial, sample size, diagnostic input, intervention, length of follow-up, outcome variables, and results. Results: Nine studies analyzing a total of 165 patients met the eligibility criteria and were included in qualitative analysis. These studies evaluated the role of NAC in cocaine dependence (three studies), cannabis dependence (two studies), nicotine dependence (two studies), methamphetamine addiction (one study), and pathological gambling (one study). Five of these trials were double-blind, randomized, and placebo-controlled. Conclusions: The studies analyzed suggest a potential role for NAC in the treatment of addiction, especially of cocaine and cannabis dependence. These results are concordant with the hypothesis of the involvement of glutamatergic pathways in the pathophysiology of addiction.Universidade Federal de São Paulo (UNIFESP) Department of Psychiatry Interdisciplinary Laboratory of Clinical Neurosciences (LINC)Santa Marcelina HospitalSchool of Medicine and Barwon Health Deakin University IMPACT Strategic Research CentreUniversity of Melbourne Florey Institute of Neuroscience and Mental Health and Orygen Youth Health Research Centre Department of PsychiatryUNIFESP, Department of Psychiatry Interdisciplinary Laboratory of Clinical Neurosciences (LINC)SciEL

O4 - Exploring the biological properties and regenerative potential of biomaterials using cell culture models

Life expectancy has improved signifcantly and, along with the declining birthrate, has contributed to the aging of populations, especially in industrialized countries. Alas, aging is intrinsically associated with the incidence of health problems including bone and tooth loss that require suitable solutions to support the quality of life. To meet these demands, signifcant research eforts have been undertaken to develop novel biomaterials, both orthopedic and dental implants. The feld of biomaterials for bone tissue engineering is increasingly evolving. The most recent generations of biomaterials have increasingly more activity and interaction with the biological environment and stimulate the regeneration of functional tissue. Natural polymers and compounds have been combined with each other to improve workability and are strategically integrated with ceramics or bioactive glasses to reinforce the structure of the fnal system, thus producing composites with a better mechanical performance. Our research group has been focused on the biological characterization of diferent added-value materials and composites, namely by evaluating their antimicrobial, biocompatibility, and regenerative properties. Some of our recent work results allowed us to conclude that marine fungal extracts, as well as sol–gel-derived bioactive glass nanoparticles, have inhibitory efects on the growth of C. albicans and E. faecalis (main pathogens in persistent root canal infections). Additionally, we have characterized cuttlefsh bone powders for endodontic applications. We are also committed to developing strategies for monitoring cell response to these biomaterials at the molecular level that could be used to follow infammation and osteoconduction.info:eu-repo/semantics/publishedVersio

The symmetric N-matrix completion problem

An $n\times n$ matrix is called an $N$-matrix if all its principal minors are negative. In this paper, we are interested in the symmetric $N$-matrix completion problem, that is, when a partial symmetric $N$-matrix has a symmetric $N$-matrix completion. Here, we prove that a partial symmetric $N$-matrix has a symmetric $N$-matrix completion if the graph of its specified entries is chordal. Furthermore, if this graph is not chordal, then examples exist without symmetric $N$-matrix completions. Necessary and sufficient conditions for the existence of a symmetric $N$-matrix completion of a partial symmetric $N$-matrix whose associated graph is a cycle are given.Fundação para a Ciência e a Tecnologia (FCT) - Programa Operacional "Ciência, Tecnologia, Inovação" (POCTI). Spanish DGI - grant number BFM2001-0081-C03-02. Generalitat Valenciana - GRUPOS03/062

Optimization of a protocol for gene expression using biofilm cells from S. epidermidis

Gene expression assays are one of the most common tools used nowadays to evaluate the importance of genes in many different life sciences areas, namely, in clinical microbiology. Since most gene expression kits for qPCR have been optimized for assays with planktonic cells it is important to also optimize protocols for this type of assays, to be used with biofilms. Biofilms are communities of bacteria that grow attached to a surface and embedded in an extracellular matrix, what poses some difficulties to RNA extraction. Proper RNA quality is of the upmost importance during all the downstream processes, namely cDNA synthesis and qPCR quantification. The aim of this work was to optimize a protocol for gene quantification from biofilm samples of S. epidermidis, a known biofilm forming nosocomial pathogen. This optimization was made in many different steps, from the RNA extraction (a crucial step) to complementary DNA (cDNA) synthesis and qPCR reactions, using growth conditions well described in the literature, so that the results obtained could be anticipated beforehand. The expression of the icaA gene was tested from RNA extracted with a custom made protocol and then quantified using a combination of 4 commercial kits of cDNA synthesis and 4 commercial kits of qPCR quantification. Furthermore, the volumes of reaction were either the volume recommended by the manufacturer (20 µl) or half that volume. From our results, we conclude that there were no significant differences of icaA expression when using any of the qPCR kits used in this study. However, using different cDNA synthesis kits, a statistical difference was found in the results obtained using one of the kits, with an icaA expression near 4-fold different than that obtained using the other kits. Interestingly, the 10 µl reaction generally resulted in higher icaA expression than when using the 20 µl reaction volume, but within the expected range of values, indicating that any of the two volumes could be used for quantification studies. Excluding the cDNA kit with low icaA levels expression, the average of icaA expression induced by glucose was similar in both cDNA and qPCR optimization steps (9.5 and 9.4 fold, respectively). The obtained protocol provides reliable results, comparable to the ones in literature, with the advantage of saving reagents. Furthermore, our results confirm that cDNA synthesis is a more crucial step that previous thought

Motivations to interact with brands on Facebook– Towards a typology of consumer–brand interactions

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Preliminary feasibility study for the use of an adsorption/bio-regeneration system for molinate removal from effluents

This work studies the feasibility of the use of a combined physical-biological remediation procedure for treatment of effluents contaminated with molinate, where the herbicide is removed through adsorption and biodegraded in a subsequent stage, with the regeneration of the adsorbent. In order to select the most adequate absorbent for molinate, different materials were tested, namely pine bark, activated carbon and resin Amberlite XAD-4. Activated carbon and resin Amberlite XAD-4 were the most efficient on the removal of molinate from solutions, although the activated carbon used proved not to be bio-regenerable. It was also observed that factors such as temperature, pH, and conductivity did not affect significantly molinate adsorption onto resin Amberlite XAD-4. Resin Amberlite XAD-4 was successfully bio-regenerated, being observed that biodegradation was mainly dependent on spontaneous desorption of the molinate. After bio-regeneration, the resin could be re-utilised as adsorbent

Development of PVD-deposited Pd-Ag functional thin films membranes on ceramic supports for hydrogen purification/separation

Palladium (Pd)-based membranes have been studied for many years, regarding applications in production and purifi-cation of hydrogen. The reaction of water gas shift (CO+ H2O ↔ CO2 + H2), for example, can advantageously be conducted in a Pd-based membrane reactor, where hydrogen produced selectively permeates the membrane [1]. When hydrogen permeates with an infinite selectivity, its passage is governed by sorption-diffusion mechanism through the atomic struc-ture. Among all metals, palladium is the material that exhibits the highest atomic hydrogen permeability, resulting from the high capability in the catalytic dissociation of H2 molecules it in its metallic structure [2]. However, the use of pure palladi-um membranes has some limitations [3]. When palladium alloys such as Pd-Ag are used, the result is a homogeneous solid solution with a fcc structure [4,5]. This alloy prevents the formation of hybrid phases, allowing higher hydrogen permeation along with chemical and mechanical stability, reducing also the overall cost of raw material [2].Patricia Pérez is grateful to Fundação para a Ciência e a Tecnologia (FCT) for the doctoral grant (reference: SFRH/BD/73673/2010). The authors also acknowledge fi-nancing from FCT through the project PTDC/EQU-ERQ/098730/2008 and COMPETE scientific program. The authors show appreciation for the collaboration of Sandra Rodrigues on the permeation experiments

Totally nonpositive completions on partial matrices

An n £ n real matrix is said to be totally no positive if every minor is no positive. In this paper, we are interested in totally no positive completion problems, that is, does A partial totally no positive matrix have a totally no positive matrix completion? This Problem has, in general, a negative answer. Therefore, we analyze the question: for which Labelled graphs G does every partial totally no positive matrix, whose associated graph is G, have a totally no positive completion? Here we study the mentioned problem when G Is a choral graph or an undirected cycle.Spanish DGI grant number BFM2001-0081-C03-02 and Generalitat Valenciana GRUPOS03/062Fundação para a Ciência e a Tecnologia (FCT

Innovative approach for decolorizing textile effluents using yeast-alginate capsules

Textile industry is an economic activity that produces high volumes of effluents used in fabric processing that are discharged in the environment [1]. These discharged effluents loaded with synthetic dyes and other chemicals, are resistant to biodegradation and persistent in water, and are responsible for toxicity and mutagenic effects on the aquatic life, causing a potential risk to the aquatic ecosystems [2]. Traditionally, industry uses classic chemical methods to treat these effluents that are expensive and potentially harmful, since it could further generate large quantities of toxic by-products that are also difficult to eliminate [3]. In order to aid and complement the traditional wastewater treatment, a yeast-based solution for decolorization of textile industrial wastewater is under evaluation. This research aims to develop a new and innovative biological solution for the effective decolorization of the textile effluents usingalginate-calcium capsules filled with a proven decolorizing yeast.info:eu-repo/semantics/publishedVersio