472 research outputs found

    The gingival Stillman's clefts: histopathology and cellular characteristics

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    Stillman's cleft is a mucogingival triangular-shaped defect on the buccal surface of a root with unknown etiology and pathogenesis. The aim of this study is to examine the Stillman's cleft obtained from excision during root coverage surgical procedures at an histopathological level

    Metal free graphene oxide (GO) nanosheets and pristine-single wall carbon nanotubes (p-SWCNTs) biocompatibility investigation: a comparative study in different human cell lines

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    The in vitro biocompatibility of Graphene Oxide (GO) nanosheets, which were obtained by the electrochemical exfoliation of graphite electrodes in an electrolytic bath containing salts, was compared with the pristine Single Wall Carbon Nanotubes (p-SWCNTs) under the same experimental conditions in different human cell lines. The cells were treated with different concentrations of GO and SWCNTs for up to 48 h. GO did not induce any significant morphological or functional modifications (demonstrating a high biocompatibility), while SWNCTs were toxic at any concentration used after a few hours of treatment. The cell viability or cytotoxicity were detected by the trypan blue assay and the lactate dehydrogenase LDH quantitative enzymatic test. The Confocal Laser Scanning Microscopy (CLSM) and transmission electron microscopy (TEM) analysis demonstrated the uptake and internalization of GO sheets into cells, which was localized mainly in the cytoplasm. Different results were observed in the same cell lines treated with p-SWCNTs. TEM and CLSM (Confocal Laser Scanning Microscopy) showed that the p-SWCNTs induced vacuolization in the cytoplasm, disruption of cellular architecture and damage to the nuclei. The most important result of this study is our finding of a higher GO biocompatibility compared to the p-SWCNTs in the same cell lines. This means that GO nanosheets, which are obtained by the electrochemical exfoliation of a graphite-based electrode (carried out in saline solutions or other physiological working media) could represent an eligible nanocarrier for drug delivery, gene transfection and molecular cell imaging tests

    O Sócrates de Hannah Arendt

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    In order to understand Arendt’s conceptions of history and political judgment, this article discusses her peculiar interpretation of Socrates. As with her other ideas, such as the banality of evil, the nature of totalitarian terror, and the public space, her portrayal of the Greek philosopher demands that we discriminate between thinking and acting. Would judgment by chance be the bridge between the activities of thought and political action? My aim in this essay is to show how Arendt, from beginning of her work, was looking for an authentic mode of political life, the major example of which is Socrates. I also address what Arendt meant by her idea of a reflexive judgment, an idea that has proved enormously suggestive yet which remains elusive. Recebido: 11/07/2016Aceito: 16/06/2017Com o fito de compreender as noções de história e juízo político, este artigo pretende mostrar a peculiar interpretação que Hannah Arendt faz da mais conhecida e discutida personalidade filosófica: Sócrates. Assim como outras idéias, tais como a de banalidade do mal, a natureza do terror totalitário e de espaço público, sua estrita pintura do filósofo grego nos demanda a tarefa de discriminar a diferença entre pensamento e ação. Seria acaso o juízo a ponte entre as atividades de pensamento e da ação política? Minha preocupação nesse ensaio é a de mostrar como Hannah Arendt estava procurando por um modo autêntico de filosofia política cujo maior exemplo seria Sócrates. No mesmo sentido, também nos debruçamos acerca do significado do juízo reflexionante, idéia bastante fecunda em sua obra que permanece ainda bastante alusiva. Recebido: 11/07/2016Aceito: 16/06/201

    Long‐term follow‐up comparison of two different bi‐layer dermal substitutes in tissue regeneration: Clinical outcomes and histological findings

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    Double layer dermal substitute (DS) consist of a 3-dimensional collagen structures and a superficial silicon layer that are positioned within the defect provide to promote tissue regeneration in skin wounds. DS often have unique physical characteristics due to differences in manufacturing techniques. The aim of this study is the clinical and histological comparison of Nevelia and Integra double layer DSs in patients with post-traumatic injury wounds. Thirty patients with post-traumatic wounds localised on the inferior limbs were randomised in 2 groups Nevelia or Integra, followed by autologous dermal epidermal graft (DEG). Clinical results were evaluated through the healing time; Manchester Scar Scale (MSS) and Visual Analog Scale (VAS) at 1, 2, and 3 weeks and after 1 and 3 years. Histological and immunohistochemical evaluation were performed at 0, 2, and 3 weeks. The difference in healing time between groups (P = .467, log-rank test), pain and self-estimation was not statistically significant after 35, 42, and 49 days and at 1-year follow up. Histological data showed evident healing of wound after 2 weeks compared with preoperative with both DSs. At 3 weeks reepithelialisation and dermal regeneration were evident with both substitutes; however Nevelia showed early regenerative properties in terms of epidermal proliferation and dermal renewal compared with Integra. Nevelia showed also a more evident angiogenesis vs Integra evaluated as α-SMA immunohistochemistry. Differences in the MSS score were statistically significant at 3 years follow up in favour of Nevelia group (P = .001). At long-term follow up, Nevelia showed a better clinical outcome measured as MSS score vs Integra measured as MSS. Histological and immunohistochemistry data showed that Nevelia allows faster neoangiogenesis and tissue regeneration with neoformed tissue architecture closer to the physiology of the skin

    Adipose-Derived Stem Cells in Bone Tissue Engineering: Useful Tools with New Applications

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    Adipose stem cells (ASCs) are a crucial element in bone tissue engineering (BTE). They are easy to harvest and isolate, and they are available in significative quantities, thus offering a feasible and valid alternative to other sources of mesenchymal stem cells (MSCs), like bone marrow. Together with an advantageous proliferative and differentiative profile, they also offer a high paracrine activity through the secretion of several bioactive molecules (such as growth factors and miRNAs) via a sustained exosomal release which can exert efficient conditioning on the surrounding microenvironment. BTE relies on three key elements: (1) scaffold, (2) osteoprogenitor cells, and (3) bioactive factors. These elements have been thoroughly investigated over the years. The use of ASCs has offered significative new advancements in the efficacy of each of these elements. Notably, the phenotypic study of ASCs allowed discovering cell subpopulations, which have enhanced osteogenic and vasculogenic capacity. ASCs favored a better vascularization and integration of the scaffolds, while improvements in scaffolds' materials and design tried to exploit the osteogenic features of ASCs, thus reducing the need for external bioactive factors. At the same time, ASCs proved to be an incredible source of bioactive, proosteogenic factors that are released through their abundant exosome secretion. ASC exosomes can exert significant paracrine effects in the surroundings, even in the absence of the primary cells. These paracrine signals recruit progenitor cells from the host tissues and enhance regeneration. In this review, we will focus on the recent discoveries which have involved the use of ASCs in BTE. In particular, we are going to analyze the different ASCs' subpopulations, the interaction between ASCs and scaffolds, and the bioactive factors which are secreted by ASCs or can induce their osteogenic commitment. All these advancements are ultimately intended for a faster translational and clinical application of BTE

    Cellular retinol binding protein 1 transfection reduces proliferation and AKT-related gene expression in H460 non-small lung cancer cells

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    In recent years, new treatments with novel action mechanisms have been explored for advanced non-small cell lung cancer (NSCLC). Retinoids promote cancer cell differentiation and death and their trafficking and action is mediated from specific cytoplasmic and nuclear receptors, respectively. The purpose of this study was to investigate the effect of Cellular retinol binding protein-1 (CRBP-1) transfection in H460 human NSCLC cell line, normally not expressing CRBP-1. H460 cells were transfected by using a vector pTargeT Mammalian expression system carrying the whole sequence of CRBP-1 gene. For proliferation and apoptosis studies, cells were treated with different concentrations ofall-transRetinoic Acid (atRA) and retinol. AKT-related gene expression was analyzed by using western blot and Signosis array and results analysed by one-way analysis of variance (ANOVA) or by t-student test. CRBP-1(+)showed reduced proliferation and viability in basal condition and afteratRA treatment when compared to empty-transfected H460 cells. Reduced proliferation in CRBP-1(+)H460 cells associated to the down-regulation of pAKT/pERK/pEGFR-related genes. In particular, gene array documented the down-regulation of AKT and Stat-3-related genes, including M-Tor, Akt1, Akt2, Akt3, Foxo1, p27, Jun. Restoration of CRBP-1 expression in H460 cells reduced proliferation and viability in both basal condition and afteratRA treatment, likely by down-regulating AKT-related gene level. Further studies are needed to better clarify how those CRBP-1-related intracellular pathways contribute to counteract NSCLC progression in order to suggest a potential tool to improve efficacy of retinoid anti lung cancer adjuvant therapy

    The key role of miRNA in syndromic and sporadic forms of ascending aortic aneurysms as biomarkers and targets of novel therapeutic strategies

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    Increasing evidence shows that epigenetics also plays a key role in regulating the pathogenetic mechanism of all types of aortic aneurysms. It is well-known that epigenetic factors modulate gene expression. This mechanism appears to be of interest especially knowing the relevance of genetic susceptibility and genetic factors in the complex pathophysiology of aortic aneurysms, and of sporadic forms; in fact, the latter are the result of a close interaction between genetic and modifiable lifestyle factors (i.e., nutrition, smoking, infections, use of drugs, alcohol, sedentary lifestyle, etc.). Epigenetic factors include DNA methylation, post-translational histone modifications, and non-coding RNA. Here, our attention is focused on the role of miRNA in syndromic and sporadic forms of thoracic aortic aneurysms. They could be both biomarkers and targets of novel therapeutic strategies

    Wound Healing: In Vitro and In Vivo Evaluation of a Bio-Functionalized Scaffold Based on Hyaluronic Acid and Platelet-Rich Plasma in Chronic Ulcers

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    Chronic ulcers are characterized by loss of substance without a normal tendency towards spontaneous healing. The Wound Bed Preparation Guideline advises that after diagnosis, the expert should correct the biological state of the ulcer micro-environment based on TIME principles (Tissue, Infection, Moisture balance, Epidermal). There are many ways to treat such ulcers, for example through use of advanced dressings, negative pressure, surgical toilets, dermal substitutes, autologous skin grafting, and free or local flaps. In vitro and in vivo pre-clinical models hold widely acknowledged potential yet complex limitations. Tissue bioengineering could be an ideal approach to foster innovative strategies in wound healing. Our observational study reports on an in vitro and in vivo evaluation of a bio-functionalized scaffold composed of platelet-rich plasma (PRP) and hyaluronic acid (HA) used in 182 patients affected by chronic ulcers (diabetic and vascular), comparing the results with a control group of 182 patients treated with traditional dressings (HA alone). After 30 days the patients who had undergone the combined treatment (PRP + HA), showed 96.8% +/- 1.5% re-epithelialization, as compared to 78.4% +/- 4.4% in the control group (HA only). Within 80 days, they had 98.4% +/- 1.3% re-epithelialization as compared to 87.8% +/- 4.1% in the control group (HA only; p < 0.05). No local recurrence was observed during the follow-up period. PRP + HA treatment showed stronger regenerative potential in terms of epidermal proliferation and dermal renewal compared with HA alone
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