Postmortem Analyses Unveil the Poor Efficacy of Decontamination, Anti-Inflammatory and Immunosuppressive Therapies in Paraquat Human Intoxications

studies resulting from human PQ poisonings have assessed the relationship of these therapeutic measures with PQ toxicokinetics and related histopathological lesions, these being the aims of the present study.For that purpose, during 2008, we collected human fluids and tissues from five forensic autopsies following fatal PQ poisonings. PQ levels were measured by gas chromatography-ion trap mass spectrometry. Structural inflammatory lesions were evaluated by histological and immunohistochemistry analysis. The samples of cardiac blood, urine, gastric and duodenal wall, liver, lung, kidney, heart and diaphragm, showed quantifiable levels of PQ even at 6 days post-intoxication. Structural analysis showed diffused necrotic areas, intense macrophage activation and leukocyte infiltration in all analyzed tissues. By immunohistochemistry it was possible to observe a strong nuclear factor kappa-B (NF-κB) activation and excessive collagen deposition.Considering the observed PQ levels in all analyzed tissues and the expressive inflammatory reaction that ultimately leads to fibrosis, we conclude that the therapeutic protocol usually performed needs to be reviewed, in order to increase the efficacy of PQ elimination from the body as well as to diminish the inflammatory process

Análise dos fatores de risco que levam ao desenvolvimento de pré-eclâmpsia/ Analysis of the risk factors that lead to the development of pre-eclampsia

Introdução: A pré-eclâmpsia pode ser caracterizada por hipertensão, proteinúria ou outras alterações de órgãos alvo, durante a gestação após a vigésima semana. Essa síndrome é marcada por um caráter multissistêmico e alterações no sistema cardiovascular que, predispõem a gestante ao desenvolvimento de aterosclerose e tromboembolismo. Assim, a associação entre possíveis fatores de risco e a incidência da pré-eclâmpsia, é algo que merece uma atenção especial.  Métodos: Revisão integrativa da literatura. As bases de dados consultadas foram LILACS, BVS, Scielo e Pubmed. Resultados: Foram selecionados 20 artigos entre os anos de 2011 a 2020. Discussão: A hipertensão quando presente na gravidez constitui a principal causa de mortalidade materno fetal e diversos fatores de risco estão envolvidos em sua patogênese. A idade materna, a obesidade, o tabagismo, infecções bacterianas, níveis elevados de ferro sanguíneo, hipertensão arterial, história prévia e familiar pré-eclâmpsia devem ser levados em consideração. Conclusão: A pré-eclâmpsia é um problema de saúde pública, sendo importante causa de morbimortalidade materno-fetal. Estudos sugerem que a história familiar e pessoal prévia de pré-eclâmpsia aumentam a incidência da doença. A identificação precoce dos fatores de risco e o manejo correto das gestantes com risco de pré-eclâmpsia é fator decisivo no desfecho clínico materno-fetal

Towards the design of 3D multiscale instructive tissue engineering constructs: Current approaches and trends

The design of 3D constructs with adequate properties to instruct and guide cells both in vitro and in vivo is one of the major focuses of tissue engineering. Successful tissue regeneration depends on the favorable crosstalk between the supporting structure, the cells and the host tissue so that a balanced matrix production and degradation is achieved. Herein, the major occurring events and players in normal and regenerative tissue are overviewed. These have been inspiring the selection or synthesis of instructive cues to include into the 3D constructs. We further highlight the importance of a multiscale perception of the range of features that can be included on the biomimetic structures. Lastly, we focus on the current and developing tissue-engineering approaches for the preparation of such 3D constructs: top-down, bottom-up and integrative. Bottom-up and integrative approaches present a higher potential for the design of tissue engineering devices with multiscale features and higher biochemichal control than top-down strategies, and are the main focus of this review.The research leading to these results has received funding from the European Research Council grant agreement ERC-2012-ADG-20120216-321266 for the project ComplexiTE. Portuguese Foundation for Science and Technology is gratefully acknowledged for the fellowship of Sara M. Oliveira (SFRH/BD/70107/2010)

The role of polymeric nanofibers on the mechanical behavior of polymethyl methacrylate resin

This study aimed to synthesize and characterize non-woven acrylonitrile butadiene styrene (ABS), polyamide-6 (P6), and polystyrene (PS) nanofibers, and evaluate their effects on the flexural strength and fracture resistance of fiber-modified polymethyl methacrylate (PMMA) resin. ABS, P6, and PS polymer solutions were prepared and electrospun into fiber mats, which were characterized by means of morphological, chemical, physical, and mechanical analyses. The fiber mats were then used to modify a thermally-activated PMMA resin, resulting in four testing groups: one unmodified group (control) and three fiber-modified groups incorporated with ABS, P6, or PS fiber mats. Flexural strength, work of fracture, and fractographic analysis were performed for all groups. Data were analyzed using Kruskal-Wallis or ANOVA tests (α = 0.05). The fiber diameter decreased, respectively, as follows: ABS > P6 > PS. Only the P6 fiber mats demonstrated a crystalline structure. Wettability was similar among the distinct fiber mats, although tensile strength was significantly greater for P6, followed by ABS, and then PS mats. Flexural strength of the fiber-modified PMMA resins was similar to the control, except for the weaker P6-based material. The work of fracture seemed to be greater and lower when the P6 and PS fibers were used, respectively. The fiber-modified groups exhibited a rougher pattern in the fractured surfaces when compared to the control, which may suggest that the presence of fibers deviates the direction of crack propa- gation, making the fracture mechanism of the PMMA resin more dynamic. While the neat PMMA showed a typical brittle response, the fiber-modified PMMA resins demonstrated a ductile response, combined with voids, suggesting large shear deformation during fracture. Altogether, despite the lack of direct reinforcement in the mechanical strength of the PMMA resin, the use of electrospun fibers showed promising application for the improvement of fracture behavior of PMMA resins, turning them into more compliant materials, although this effect may depend on the fiber compositio