Turning off the switch in medulloblastoma. The inhibitory acetylation of an oncogene

[No abstract available

Topology optimization of flexoelectric metamaterials with apparent piezoelectricity

The flexoelectric effect, coupling polarization and strain gradient as well as strain and electric field gradients, is universal to dielectrics, but, as compared to piezoelectricity, it is more difficult to harness as it requires field gradients and it is a small-scale effect. These drawbacks can be overcome by suitably designing metamaterials made of a non-piezoelectric base material but exhibiting apparent piezoelectricity. We develop a theoretical and computational framework to perform topology optimization of the representative volume element of such metamaterials by accurately modeling the governing equations of flexoelectricity using a Cartesian B-spline method, describing geometry with a level set, and resorting to genetic algorithms for optimization. We consider a multi-objective optimization problem where area fraction competes with four fundamental piezoelectric functionalities (stress/strain sensor/ actuator). We computationally obtain Pareto fronts, and discuss the different geometries depending on the apparent piezoelectric coefficient being optimized. In general, we find competitive estimations of apparent piezoelectricity as compared to reference materials such as quartz and PZT ceramics. This opens the possibility to design devices for sensing, actuation and energy harvesting from a much wider, cheaper and effective class of materials

Mechanisms underlying heterologous skin scaffold-mediated tissue remodeling

Biocompatibility of two newly developed porcine skin scaffolds was assessed after 3, 14, 21 and 90 days of implantation in rats. Both scaffolds showed absence of cells, preservation of ECM and mechanical properties comparable to non-decellularised skin before implantation. Host cell infiltration was much prominent on both scaffolds when compared to Permacol (surgical control). At day 3, the grafts were surrounded by polymorphonuclear cells, which were replaced by a notable number of IL-6-positive cells at day 14. Simultaneously, the number of pro-inflammatory M1-macrophage was enhanced. Interestingly, a predominant pro-remodeling M2 response, with newly formed vessels, myofibroblasts activation and a shift on the type of collagen expression was sequentially delayed (around 21 days). The gene expression of some trophic factors involved in tissue remodeling was congruent with the cellular events. Our findings suggested that the responsiveness of macrophages after non-crosslinked skin scaffolds implantation seemed to intimately affect various cell responses and molecular eventsand this range of mutually reinforcing actions was predictive of a positive tissue remodeling that was essential for the long-standing success of the implants. Furthermore, our study indicates that non-crosslinked biologic scaffold implantation is biocompatible to the host tissue and somehow underlying molecular events involved in tissue repair.Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)Fed Univ Sao Paulo UNIFESP, Postgrad Struct & Funct Biol, BR-04023900 Sao Paulo, SP, BrazilSao Paulo State Univ UNESP, Dept Biol, BR-15054000 Sao Jose Do Rio Preto, SP, BrazilSao Paulo State Univ UNESP, Inst Biociencias Letras & Ciencias Exatas, BR-15054000 Sao Jose Do Rio Preto, SP, BrazilUCL, Northwick Pk Inst Med Res, Dept Surg Res, London HA1 3UJ, Middx, EnglandPost-Graduation in Structural and Functional Biology, Universidade Federal de São Paulo (UNIFESP), São Paulo, SP, 04023-900, BrazilFAPESP: 2012/21603-2FAPESP: 2012/13041-4FAPESP: 2014/18557-4CNPq: 308144/2014-7CNPq: 245859/2012-8Web of Scienc

Lambliasis-associated Schönlein-Henoch purpura in an Italian traveller: first case report in Italy

A unique report of Schönlein-Henoch purpura (SHP) associated with a recent Giardia lamblia enteric infectionis described and discussed on the ground of the available literature. Tinidazole plus an appropriateprobiotic therapy, including Lactobacillus reuteri and vitamin D, proved to be effective in the condition.SHP is an immunocomplex-mediated disorder characterised by a number of differently associated signsand symptoms, leading to the possible involvement of the skin, joints, abdomen and kidneys. Recentbacterial, viral, or protozoan infections may trigger the disease onset in patients of all ages. The paper describesthe first case of SHP triggered by a giardiasis. Tinidazole plus an appropriate probiotic therapy, i.e.L. reuteri and vitamin D proved to be effective in this condition. To our knowledge, this is the first reportedcase of lambliasis-associated SHP described in an international traveller

Spontaneous bacterial peritonitis by Listeria monocytogenes. A rare case and literature review

Spontaneous bacterial peritonitis (SBP) is a bacterial infection of ascites and a common complication in patients with cirrhosis, associated with a high morbidity and mortality rate. Gram-negative Enterobacteriaceae bacteria are usually the major pathogens involved in SBP, with Klebsiella pneumoniae accounting for 50% of these. Individuals with chronic liver and /or kidney disease associated with long-standing ascites are predisposed to SBP. Nosocomial SBP presents most commonly a poorer outcome. Although Listeria monocytogenes peritonitis is a relatively rare focal manifestation of Listeria infection, its incidence is increasing. It is associated with a mortality rate approaching 30% in cases of systemic involvement, despite first-line therapy. To our knowledge, this is the first case of L.monocytogenes-associated SBP described in Italy. Clinicians should be aware of the uncommon agents of SBP, such as Listeria, because, if diagnosed early, early antibiotic administration is crucial in minimizing adverse outcomes.