Clinical Epidemiology of Buruli ulcer from Benin (2005-2013): effect of time-delay to diagnosis on clinical forms and severe phenotypes

Buruli Ulcer (BU) is a neglected infectious disease caused by Mycobacterium ulcerans that is responsible for severe necrotizing cutaneous lesions that may be associated with bone involvement. Clinical presentations of BU lesions are classically classified as papules, nodules, plaques and edematous infiltration, ulcer or osteomyelitis. Within these different clinical forms, lesions can be further classified as severe forms based on focality (multiple lesions), lesions' size (>15 cm diameter) or WHO Category (WHO Category 3 lesions). There are studies reporting an association between delay in seeking medical care and the development of ulcerative forms of BU or osteomyelitis, but the effect of time-delay on the emergence of lesions classified as severe has not been addressed. To address both issues, and in a cohort of laboratory-confirmed BU cases, 476 patients from a medical center in Allada, Benin, were studied. In this laboratory-confirmed cohort, we validated previous observations, demonstrating that time-delay is statistically related to the clinical form of BU. Indeed, for non-ulcerated forms (nodule, edema, and plaque) the median time-delay was 32.5 days (IQR 30.0-67.5), while for ulcerated forms it was 60 days (IQR 20.0-120.0) (p = 0.009), and for bone lesions, 365 days (IQR 228.0-548.0). On the other hand, we show here that time-delay is not associated with the more severe phenotypes of BU, such as multi-focal lesions (median 90 days; IQR 56-217.5; p = 0.09), larger lesions (diameter >15 cm) (median 60 days; IQR 30-120; p = 0.92) or category 3 WHO classification (median 60 days; IQR 30-150; p = 0.20), when compared with unifocal (median 60 days; IQR 30-90), small lesions (diameter =15 cm) (median 60 days; IQR 30-90), or WHO category 1+2 lesions (median 60 days; IQR 30-90), respectively. Our results demonstrate that after an initial period of progression towards ulceration or bone involvement, BU lesions become stable regarding size and focal/multi-focal progression. Therefore, in future studies on BU epidemiology, severe clinical forms should be systematically considered as distinct phenotypes of the same disease and thus subjected to specific risk factor investigation.

Hibridação e pós-colonialismo

A hibridização refere-se a um modo de conhecimento e de ação associados com o híbrido. E esta última idéia denota os interstícios, a rede de relacionamentos, os lugares e as instâncias que, à medida que fundem as suas essências e experiências, geram novas produções e reproduções de si mesmos. O hibridismo é percebido por várias escolas de pensamento e por muitos autores literários como uma das principais armas contra o colonialismo. Isto é especialmente verdadeiro para os teóricos do pós-colonialismo, como Edward Said e Homi Bhabha. Se o entendimento do hibridismo é fundamental para a reflexão que os Estudos Pós-Coloniais empreendem sobre a nossa sociedade intercultural, também é verdade que essa escola de pensamento mostra-se, ela própria, híbrida desde as suas origens. Na verdade, na nossa era pós-colonial, os textos literários e até mesmo a escrita científica (histórica, sociológica, etc ) exibem uma natureza cada vez intercultural. Mas como podem estes ‘Estudos Híbridos’, de que uma manifestação recente é a Hibridologia, através de um historiador, um sociólogo, um antropólogo ou um crítico literário, detectar tais significados públicos polissémicos que conduzem a uma mais intensa comunicação intercultural? Uma das respostas possíveis pode ser a seguinte hipótese: além da leitura e escrita de saberes especializados, os conceitos comuns (um termo central na fenomenologia sociológica de Alfred Schutz), utilizados por pessoas comuns de diferentes origens culturais numa base diária, pode constituir uma das chaves para a compreensão mútua entre as diferentes culturas hoje interligadas nas nossas sociedades pós-coloniais globais.

Bioethanol production by Saccharomyces cerevisiae, Pichia stipitis and Zymomonas mobilis from delignified coconut fibre mature and lignin extraction according to biorefinery concept

In search to increase the offer of liquid, clean, renewable and sustainable energy in the world energy matrix, the use of lignocellulosic materials (LCMs) for bioethanol production arises as a valuable alternative. The objective of this work was to analyze and compare the performance of Saccharomyces cerevisiae, Pichia stipitis and Zymomonas mobilis in the production of bioethanol from coconut fibre mature (CFM) using different strategies: simultaneous saccharification and fermentation (SSF) and semi-simultaneous saccharification and fermentation (SSSF). The CFM was pretreated by hydrothermal pretreatment catalyzed with sodium hydroxide (HPCSH). The pretreated CFM was characterized by X-ray diffractometry and SEM, and the lignin recovered in the liquid phase by FTIR and TGA. After the HPCSH pretreatment (2.5% (v/v) sodium hydroxide at 180 °C for 30 min), the cellulose content was 56.44%, while the hemicellulose and lignin were reduced 69.04% and 89.13%, respectively. Following pretreatment, the obtained cellulosic fraction was submitted to SSF and SSSF. Pichia stipitis allowed for the highest ethanol yield 90.18% in SSSF, 91.17% and 91.03% were obtained with Saccharomyces cerevisiae and Zymomonas mobilis, respectively. It may be concluded that the selection of the most efficient microorganism for the obtention of high bioethanol production yields from cellulose pretreated by HPCSH depends on the operational strategy used and this pretreatment is an interesting alternative for add value of coconut fibre mature compounds (lignin, phenolics) being in accordance with the biorefinery concept.

Folate-targeted nanoparticles for rheumatoid arthritis therapy

Rheumatoid arthritis (RA) is the most common inflammatory rheumatic disease, affecting almost 1% of the world population. Although the cause of RA remains unknown, the complex interaction between immune mediators (cytokines and effector cells) is responsible for the joint damage that begins at the synovial membrane. Activated macrophages are critical in the pathogenesis of RA and have been shown to specifically express a receptor for the vitamin folic acid (FA), folate receptor (FR). This particular receptor allows internalization of FA-coupled cargo. In this review we will address the potential of nanoparticles as an effective drug delivery system for therapies that will directly target activated macrophages. Special attention will be given to stealth degree of the nanoparticles as a strategy to avoid clearance by macrophages of the mononuclear phagocytic system (MPS). This review summarizes the application of FA-target nanoparticles as drug delivery systems for RA and proposes prospective future directions.

Qualidade do relacionamento com pessoas significativas: comparação entre grávidas adolescentes e adultas

Na gravidez, a mulher experiencia mudanças desenvolvimentais ao nível dos seus relacionamentos significativos. Este estudo compara a qualidade do relacionamento com o companheiro e com outra figura significativa em grávidas adolescentes e adultas, e analisa preditores sócio-demográficos para a qualidade destes relacionamentos. Uma amostra de 130 grávidas (66 adolescentes e 64 adultas) foi avaliada no terceiro trimestre de gestação quanto às características sociais e demográficas e à qualidade do relacionamento com figuras significativas. Os resultados mostram que as adolescentes referem menor confiança (χ2 = 3.365, p = 0,055) e maior discórdia (χ2 = 3.842, p = 0,041) no relacionamento com o companheiro e maior sentimento de ligação (χ2 = 19.126, p = 0,000) e apatia (χ2 = 8.568, p = 0,004) no relacionamento com a outra figura significativa, comparativamente com as adultas. Verifica-se ainda que a gravidez na adolescência associa-se a relacionamentos de menor qualidade, especialmente devido a situações sócio-demográficas mais desfavoráveis e não tanto à condição de ser ou não adolescente.