Virtual Element Method for fourth order problems: L2−L^2-estimates

We analyse the family of $C^1$-Virtual Elements introduced in \cite{Brezzi:Marini:plates} for fourth-order problems and prove optimal estimates in $L^2$ and in $H^1$ via classical duality arguments

Universal emulsion stabilization from the arrested adsorption of rough particles at liquid-liquid interfaces

Surface heterogeneities, including roughness, significantly affect the adsorption, motion and interactions of particles at fluid interfaces. However, a systematic experimental study, linking surface roughness to particle wettability at a microscopic level, is currently missing. Here we synthesize a library of all-silica microparticles with uniform surface chemistry, but tuneable surface roughness and study their spontaneous adsorption at oil-water interfaces. We demonstrate that surface roughness strongly pins the particles' contact lines and arrests their adsorption in long-lived metastable positions, and we directly measure the roughness-induced interface deformations around isolated particles. Pinning imparts tremendous contact angle hysteresis, which can practically invert the particle wettability for sufficient roughness, irrespective of their chemical nature. As a unique consequence, the same rough particles stabilize both water-in-oil and oil-in-water emulsions depending on the phase they are initially dispersed in. These results both shed light on fundamental phenomena concerning particle adsorption at fluid interfaces and indicate future design rules for particle-based emulsifiers

Aberrant neuronal activity-induced signaling and gene expression in a mouse model of RASopathy

Noonan syndrome (NS) is characterized by reduced growth, craniofacial abnormalities, congenital heart defects, and variable cognitive deficits. NS belongs to the RASopathies, genetic conditions linked to mutations in components and regulators of the Ras signaling pathway. Approximately 50% of NS cases are caused by mutations in PTPN11. However, the molecular mechanisms underlying cognitive impairments in NS patients are still poorly understood. Here, we report the generation and characterization of a new conditional mouse strain that expresses the overactive Ptpn11D61Y allele only in the forebrain. Unlike mice with a global expression of this mutation, this strain is viable and without severe systemic phenotype, but shows lower exploratory activity and reduced memory specificity, which is in line with a causal role of disturbed neuronal Ptpn11 signaling in the development of NS-linked cognitive deficits. To explore the underlying mechanisms we investigated the neuronal activity-regulated Ras signaling in brains and neuronal cultures derived from this model. We observed an altered surface expression and trafficking of synaptic glutamate receptors, which are crucial for hippocampal neuronal plasticity. Furthermore, we show that the neuronal activity-induced ERK signaling, as well as the consecutive regulation of gene expression are strongly perturbed. Microarray-based hippocampal gene expression profiling revealed profound differences in the basal state and upon stimulation of neuronal activity. The neuronal activity-dependent gene regulation was strongly attenuated in Ptpn11D61Y neurons. In silico analysis of functional networks revealed changes in the cellular signaling beyond the dysregulation of Ras/MAPK signaling that is nearly exclusively discussed in the context of NS at present. Importantly, changes in PI3K/AKT/mTOR and JAK/STAT signaling were experimentally confirmed. In summary, this study uncovers aberrant neuronal activity-induced signaling and regulation of gene expression in Ptpn11D61Y mice and suggests that these deficits contribute to the pathophysiology of cognitive impairments in NS

Case report: Childhood epilepsy and borderline intellectual functioning hiding an AADC deficiency disorder associated with compound heterozygous DDC gene pathogenic variants

Aromatic L-amino acid decarboxylase (AADC) deficiency is a rare autosomal recessive neurometabolic disorder leading to severe combined serotonin, dopamine, norepinephrine, and epinephrine deficiency. We report on a female patient with borderline functioning and sporadic clear-cut focal to bilateral seizures from age 10 years. A neuropsychological assessment highlighted a mild impairment in executive functions, affecting attention span and visual-spatial abilities. Following the diagnosis of epilepsy with a presumed genetic etiology, we applied a diagnostic approach inclusive of a next-generation sequencing (NGS) gene panel, which uncovered two variants in trans in the DOPA decarboxylase (DDC) gene underlying an AADC deficiency. This compound heterozygous genotype was associated with a mild reduction of homovanillic acid, a low level of the norepinephrine catabolite, and a significant reduction of 5-hydroxyindoleacetic acid in cerebrospinal fluid. Remarkably, 3-O-methyldopa (3-OMD) and 5-hydroxytryptophan were instead increased. During the genetically guided re-evaluation process, some mild signs of dysautonomic dysfunction (nasal congestion, abnormal sweating, hypotension and fainting, excessive sleepiness, small hands and feet, and increased levels of prolactin, tiredness, and fatigue), more typical of AADC deficiency, were evaluated with new insight. Of the two AADC variants, the R347Q has already been characterized as a loss-of-function with severe catalytic impairments, while the novel L391P variant has been predicted to have a less severe impact. Bioinformatic analyses suggest that the amino acid substitution may affect affinity for the PLP coenzyme. Thus, the genotype corresponds to a phenotype with mild and late-onset symptoms, of which seizures were the clinical sign, leading to medical attention. This case report expands the spectrum of AADC deficiency phenotypes to encompass a less-disabling clinical condition including borderline cognitive functioning, drug-responsive epilepsy, and mild autonomic dysfunction

A novel role of c-FLIP protein in regulation of ER stress response

Cellular-Flice-like Inhibitory Protein (c-FLIP) is an apoptosis modulator known to inhibit the extrinsic apoptotic pathway thus blocking Caspase-8 processing in the Death Inducing Signalling Complex (DISC). We previously demonstrated that c-FLIP localizes at the Endoplasmic Reticulum (ER) and that c-FLIP-deficient Mouse Embryonic Fibroblasts (MEFs) display an enlarged ER morphology. In the present study, we have addressed the consequences of c-FLIP ablation in the ER stress response by investigating the effects of pharmacologically-induced ER stress in Wild Type (WT) and c-FLIP-/- MEFs. Surprisingly, c-FLIP-/- MEFs were found to be strikingly more resistant than WT MEFs to ER stress-mediated apoptosis. Analysis of Unfolded Protein Response (UPR) pathways revealed that Pancreatic ER Kinase (PERK) and Inositol-Requiring Enzyme 1 (IRE1) branch signalling is compromised in c-FLIP-/- cells when compared with WT cells. We found that c-FLIP modulates the PERK pathway by interfering with the activity of the serine threonine kinase AKT. Indeed, c-FLIP-/- MEFs display higher levels of active AKT than WT MEFs upon ER stress, while treatment with a specific AKT inhibitor of c-FLIP-/- MEFs subjected to ER stress restores the PERK but not the IRE1 pathway. Importantly, the AKT inhibitor or dominant negative AKT transfection sensitizes c-FLIP-/- cells to ER stress-induced cell death while the expression of a constitutively active AKT reduces WT cells sensitivity to ER stress-induced death. Thus, our results demonstrate that c-FLIP modulation of AKT activity is crucial in controlling PERK signalling and sensitivity to ER stress, and highlight c-FLIP as a novel molecular player in PERK and IRE1-mediated ER stress response

Clinical, histological, immunohistochemical and biomolecular analysis of hyaluronic acid in early wound healing of human gingival tissues: a randomized, split‐mouth trial

Background: Hyaluronic acid (HA) exerts a fundamental role in tissue repair. In vitro and animal studies demonstrated its ability to enhance wound healing. Nevertheless, in vivo human studies evaluating mechanisms involved in oral soft tissue repair are lacking. The aim of this study was to evaluate the in vivo effect of HA on early wound healing of human gingival tissues (G). Methods: In the present randomized, split-mouth, double-blind, clinical trial, G biopsies were obtained in eight patients 24 hours after surgery after HA application (treatment group-HA) and compared with those obtained from the same patients without HA application (no treatment group-NT). Clinical response was evaluated through Early Wound Healing Score (EHS). Microvascular density (MVD), collagen content and cellular proliferation were evaluated through Sirius red, Masson trichrome staining and Ki67 immunohistochemistry, respectively. To assess collagen turnover, MMP-1, MMP-2, MMP-9, TGF-β1 protein levels and LOX, MMP-1, TIMP-1, TGF-β1 gene expression were analysed by Western Blot and Real Time PCR. Results: Twenty-four hours after surgery, EHS was significantly higher in HA group. MVD, collagen content and cell proliferation were not affected. LOX mRNA, MMP-1 protein and TIMP-1 gene expression were significantly up-regulated in HA compared to NT group. Conclusions: The additional use of 0.8% HA gel does not modify the new blood vessels growth in the early phase of gingival wound healing. Concerning the secondary outcomes, HA seems to enhance extracellular matrix remodelling and collagen maturation, that could drive the early wound healing of gingival tissues to improve clinical parameters. This article is protected by copyright. All rights reserved

Galactosylated Prodrugs: A Strategy to Improve the Profile of Nonsteroidal Anti-Inflammatory Drugs

Carbohydrates are one of the most abundant and important classes of biomolecules. The variety in their structures makes them valuable carriers that can improve the pharmaceutical phase, pharmacokinetics and pharmacodynamics of well-known drugs. D-galactose is a simple, naturally occurring monosaccharide sugar that has been extensively studied for use as a carrier and has proven to be valuable in this role. With the aim of validating the galactose-prodrug approach, we have investigated the galactosylated prodrugs ibuprofen, ketoprofen, flurbiprofen and indomethacin, which we have named IbuGAL, OkyGAL, FluGAL and IndoGAL, respectively. Their physicochemical profiles in terms of lipophilicity, solubility and chemical stability have been evaluated at different physiological pH values, as have human serum stability and serum protein binding. Ex vivo intestinal permeation experiments were performed to provide preliminary insights into the oral bioavailability of the galactosylated prodrugs. Finally, their anti-inflammatory, analgesic and ulcerogenic activities were investigated in vivo in mice after oral treatment. The present results, taken together with those of previous studies, undoubtedly validate the galactosylated prodrug strategy as a problem-solving technique that can overcome the disadvantages of NSAIDs

Microvesicles secreted from equine amniotic cells and their potential role in in vitro cell tendon repair

The regenerative mechanisms ascribed to mesenchymal stem cells (MSCs) are classified into 3 categories: differentiating into damaged cell types, supplying nutrients, and improving survival/functions of the endogenous cells via paracrine actions. However, because of the inhospitable microenvironment of the injured tissues, a proportion of the implanted MSCs may quickly die, suggesting that other mechanisms might be present. This notion is supported by the overlapping beneficial effect (in terms of time of healing) resulted  after the injection of AMCs or of amniotic mesenchymal cells - conditioned medium (AMC-CM)  in equine spontaneous injured tendons and ligaments. Microvesicles (MVs) released by cells are an integral component of the cell-to-cell communication network involved in tissue regeneration.In the present study, MVs secreted by AMCs were investigated with Nanosigth instrument and TEM. Then, the in vitro incorporation of MVs into equine tendon cells was studied by a dose-response curve. Lastly, the ability of MVs to counteract an in vitro inflammatory process induced by lipolysaccaride on tendon cells was studied evaluating the expression of pro-inflammatory genes like metallopeptidase (MPP) 1 and 13, and prostaglandin-endoperoxide synthase 2 (COX2). Results demonstrated that AMCs secreted MVs ranging in size from 100 to 1000 nm with a prevalence of 100-200 nm large MVs. Tendon cells were able to uptake them with an inverse relationship between concentration and time. The greatest incorporation was detectable at 40x106 MVs/ml after 72h. MVs induced down-regulation of MMP1 and MMP13, suggesting that they may have contributed, along with soluble factors, to in vivo tendon regeneration

O LIVRO, O ESPAÇO, A MEMÓRIA: A DICOTOMIA DOM/MALDIÇÃO NOS CONTOS BORGEANOS

RESUMO: Os contos “O livro de Areia”, “O Aleph” e “Funes, o memorioso” são perpassados pela dicotomia dom/maldição, pois repetem o mesmo conceito de se possuir algo precioso, mas que também se torna algo terrível, intolerável. Borges urde novos arranjos numa série combinatória de contos entrelaçados pela mesma dicotomia e uso de temas recorrentes. O objetivo do artigo é ressaltar as repetições de variantes nos contos ficcionais borgeanos elencados acima. Com a análise dos contos selecionados propõe-se destacar os procedimentos empreendidos pelo escritor na tessitura da ficção do realismo fantástico.PALAVRAS-CHAVE: contos borgeanos; dicotomia dom/maldição; temas recorrentes