Removal of the Antibiotic Sulfamethoxazole by “Green” Clay Sorbents

Contamination of water resources with pharmaceuticals has been one of the top concerns of environmental sciences in the latest years [1, 2], the matter having received very significant media coverage recently [2, 3]. Antibiotics in particular have been gathering considerable attention and are amongst the most serious worries due to the development of antibiotic resistant bacteria as result of prolonged exposure [1, 2, 3]. In particular, antimicrobials and their metabolites are being detected in significant amounts in water supplies, and although no evidence exists that human health is affected by minute doses of antibiotics over long periods of time, changes have been observed in ecosystem functions [3,4]. In addition to antimicrobial resistance, other effects have been observed such as a delay in cell growth of bacteria, limited denitrification, and shifts in community composition [5]. Sulfamethoxazole (SMX), a broad-spectrum biostatic sulfanilamide, has become a point of interest because of its prevalence in contaminated wastewaters at concentrations correlated to bacterial resistance and genetic mutations in organisms [3,4,5]. Taking into account the widespread use of sulfonamides and their potential environmental effects, there is importance in developing new technologies for removing SMX and similar compounds from points of discharge. In fact, most wastewater treatment plants are inefficient for the removal of most micropollutants, especially hardly biodegradable organic xenobiotics which are present in wastewaters at low concentrations, as these conventional systems were only designed for removing bulk pollutants. Several advanced technologies have been evaluated as options to treat these contaminants, e.g. advanced oxidative processes or membrane filtration, but despite the sometimes high removal efficiencies attained, these technologies are too expensive to be considered as viable solutions on a large scale. Adsorption, alone or as part of a more complex water or wastewater treatment process, has been seen as playing a very important role in the removal of many organic xenobiotic pollutants [6, 7]. In this regard, the choice of adsorbent materials is crucial. However, pollutants removal efficiency is not the sole selection criterion, as the cost of the materials may provide or preclude economic viability of the water/wastewater treatment system. Therefore, the quest for efficient adsorbents that are widely available, and do not require expensive processing in order to be used (thereby allowing lower production costs) is a very important aspect of research aimed to manage this environmental problem. In this work we present the study of sorption properties of clay materials (LECA and vermiculite) for the removal of SMX from water. The dependence of removal efficiencies on the antibiotic initial concentrations, contact time with the adsorbents and other system/environment conditions was assessed. The two clay materials were compared in terms of their more balanced performance towards the removal of the pharmaceutical tested and the materials are suggested as a useful component of a water or wastewater treatment system designed for the removal of this contaminant (and others of similar type). Vermiculite was shown to be more efficient than LECA in the adsorption of the pharmaceutical and the one with faster kinetics. In other to gain a deeper insight into the characteristics that favor the removal of this compound by mineral surfaces, quantum chemical theoretical calculations were performed to illustrate the type of interactions that are responsible for the preferable adsorption of the compound to the vermiculite surface

Conjugated linoleic acid reduces permeability and fluidity of adipose plasma membranes from obese Zucker rats

NOTICE: this is the author’s version of a work that was accepted for publication in Biochemical and Biophysical Research Communications. Changes resulting from the publishing process, such as peer review, editing, corrections, structural formatting, and other quality control mechanisms may not be reflected in this document. Changes may have been made to this work since it was submitted for publication. A definitive version was subsequently published in Biochemical and Biophysical Research Communications. July 2010; 398 (2): 199-204.Conjugated linoleic acid (CLA) is a dietary fatty acid frequently used as a body fat reducing agent whose effects upon cell membranes and cellular function remain unknown. Obese Zucker rats were fed atherogenic diets containing saturated fats of vegetable or animal origin with or without 1% CLA, as a mixture of cis(c)9,trans(t)11 and t10,c12 isomers. Plasma membrane vesicles obtained from visceral adi- pose tissue were used to assess the effectiveness of dietary fat and CLA membrane incorporation and its outcome on fluidity and permeability to water and glycerol. A significant decrease in adipose membrane fluidity was correlated with the changes observed in permeability, which seem to be caused by the incor- poration of the t10,c12 CLA isomer into membrane phospholipids. These results indicate that CLA supple- mentation in obese Zucker rats fed saturated and cholesterol rich diets reduces the fluidity and permeability of adipose membranes, therefore not supporting CLA as a body fat reducing agent through membrane fluidification in obese fat consumers

ALERGIA A FÁRMACOS COM MANIFESTAÇÕES CUTÂNEAS - ABORDAGEM DIAGNÓSTICA

Adverse drug reactions constitute a major health problem in clinical practice. Drug allergy is defined as an immunologically mediated hypersensitivity reaction and represents 6-10% of all adverse drug reactions. Cli- nically, drug-induced allergic reactions can be classified as immediate (type I) and non-immediate (heterogeneous clinical manifestations, mostly related to type IV reactions). Several issues are considered in this revision, particularly immunopathologic mechanisms, cross-reactivity and the most relevant cutaneous reactions (maculopapular exanthe- ma, fixed drug eruption, acute generalized exanthematic pustulosis, drug hypersensitivity syndrome, also referred as drug rash with eosinophilia and systemic symptoms – DRESS, Stevens-Johnson syndrome and toxic epidermal necrolysis). The role of skin tests (epicutaneous or intradermal with late reading) in the diagnostic approach of non- -immediate reactions is also analysed. The most important causes of hypersensitivity reactions are antibiotics, parti- cularly beta-lactams. This group poses significant diagnostic and management difficulties and deserves, therefore, a more thorough attention, with particular attention to cross-reactivity patterns. Induction of drug tolerance should be considered in selected cases, especially when no safe or effective drug alternatives are available.KEYWORDS – Drug hypersensitivity; Beta-Lactams; Cross reactions; Skin Tests.As reacções adversas a fármacos (RAF) representam um problema frequente na prática clínica. A alergia a fármacos resulta de mecanismos de hipersensibilidade imunológica e representa 6-10% do total de RAF. Clinica- mente, as reacções alérgicas a fármacos podem ser classificadas como imediatas (tipo I) ou não-imediatas (com manifestações clínicas diversas e associadas sobretudo a reacções de tipo IV). Neste artigo são abordados aspectos gerais, nomeadamente os mecanismos imunopatogénicos implicados na alergia a fármacos e reactividade cruzada mas também as manifestações cutâneas mais relevantes, nomeadamente exantemas máculo-papulares, eritema fixo a fármacos (EFF), pustulose exantemática aguda generalizada (PEAG), síndrome de hipersensibilidade a fármacos (DRESS – drug rash with eosinophilia and systemic symptoms), síndrome de Stevens-Johnson/necrólise epidérmica tóxica (SSJ/NET). O papel dos testes cutâneos (epicutâneos ou intradérmicos de leitura tardia) na abordagem de reacções não-imediatas é também revisto. Os beta-lactâmicos (BL) são o grupo farmacológico mais frequentemente envolvido em reacções de hipersensibilidade imunológica e que mais dificuldades coloca na prática clínica diária, nomeadamente devido aos riscos de reactividade cruzada, pelo que é analisado em maior detalhe ao longo da revisão. A indução de tolerância a fármacos poderá ser considerada em casos selecionados, sobretudo quando na ausência de alternativas terapêuticas igualmente eficazes ou seguras.PALAVRAS-CHAVE – Hipersensibilidade a fármacos; Beta-Lactâmicos; Reactividade cruzada; Testes cutâneos

Effect of dietary conjugated linoleic acid isomers on water and glycerol permeability of kidney membranes

NOTICE: this is the author’s version of a work that was accepted for publication in Biochemical and Biophysical Research Communications. Changes resulting from the publishing process, such as peer review, editing, corrections, structural formatting, and other quality control mechanisms may not be reflected in this document. Changes may have been made to this work since it was submitted for publication. A definitive version was subsequently published in Biochemical and Biophysical Research Communications. May 2009; 383(1): 108-112.Conjugated linoleic acid (CLA) refers to a group of positional and geometrical isomers of linoleic acid in which the double bonds are conjugated. Dietary CLA has been associated with various health benefits although details of its molecular mode of action remain elusive. The effect of CLA supplemented to palm oil-based diets in Wistar rats, as a mixture of both or isolated c9,t11 and t10,c12 isomers, was examined on water and glycerol membrane permeability of kidney proximal tubule. Although water permeability was unaltered, an increase in glycerol permeability was obtained for the group supplemented with CLA mixture, even though the activation energy for glycerol permeation remained high. This effect was correlated with an increased CLA isomeric membrane incorporation for the same dietary group. These results suggest that diet supplementation with CLA mixture, in contrast to its individual isomers, may enhance membrane fluidity subsequently raising kidney glycerol reabsorption

Influence of feeding graded levels of canned sardines on the inflammatory markers and tissue fatty acid composition of Wistar rats

The present study was supported by Fundacao para a Ciencia e a Tecnologia (FCT) through the grant PTDC-SAU/OSM/2006/70560 (principal investigator: P. O. R). S. V. M. is the recipient of a FCT individual fellowship SFRH/BPD/2009/63019 and P. A. L. is a researcher involved in the FCT programme 'Ciencia 2008'.Canned sardines are a ready-to-use fish product with excellent nutritional properties owing to its high n-3 long-chain PUFA content, mainly EPA (20 : 5n-3) and DHA (22 : 6n-3). The present study aimed to assess the effect of two dosages of canned sardines, recommended for the primary and secondary prevention of human CVD, on the inflammatory marker concentrations and fatty acid composition of erythrocytes and key metabolic tissues (liver, muscle, adipose tissue and brain) in the rat model. Wistar rats were fed a diet containing 11\% (w/w) of canned sardines (low-sardine (LS) diet) and a diet containing 22\% (w/w) of canned sardines (high-sardine (HS) diet) for 10 weeks. Daily food intake, weight gain, and organ and final body weights were not affected by the dietary treatments. The concentrations of total cholesterol, HDL-cholesterol and LDL-cholesterol decreased in both the LS and HS groups, while those of alanine aminotransferase and adiponectin increased. The concentrations of IL-1 beta increased only with the highest dosage of sardine. The dose-dependent influence of the graded levels of EPA+DHA was tissue specific. Compared with that of other tissues and erythrocytes, the fatty acid composition of the brain was less affected by the canned sardine-supplemented diets. In contrast, the retroperitoneal adipose tissue was highly responsive. The deposition ratios of EPA and DHA indicated that the LS diet was optimal for DHA deposition across the tissues, except in the retroperitoneal adipose tissue. Taken together, our findings indicate that a LS diet positively affects plasma lipid profiles and inflammatory mediators, whereas a HS diet has contradictory effects on IL-1 beta, which, in turn, is not associated with variations in the concentrations of other pro-inflammatory cytokines. This finding requires further investigation and pathophysiological understanding.publishersversionpublishe

Estudos Artísticos

Arte: ativar o humano. Dentro do desafio do “Congresso CSO, Criadores Sobre outras Obras,”– em que artistas são chamados a escrever sobre a obra de outros artistas, no âmbito dos países de língua portuguesa ou espanhola, – a Revista Croma interessa-se pelas instâncias de intervenção, implicação, aproximação junto das comunidades, de excluídos, de comunidades menos diferenciadas. Há um vasto campo de ação onde têm surgido movimentos para novas relações, conhecimentos, atitudes e práticas. Se a dimensão relacional tem vindo a ser problematizada com maior insistência no contexto da crítica contemporânea, especialmente na vertente que se debruça sobre o efeito ideológico do orientalismo e da realidade pós-colonial, então os 16 artigos que se alinham nesta edição fornecem leituras alternativas sobre as dinâmicas da arte contemporânea. Sobre as relações sociais tecem-se ligações intermediadoras. Os seus resultados habitam as cidades, geram novas formas de pensar, renovam discursos, promovem identidade. Trata-se de habitar de novo os espaços vazios, de ativar o humano, que é também onde se podem encontrar as novas formulações artísticas.info:eu-repo/semantics/publishedVersio