121 research outputs found

    Stones for the production of binding materials in Florence area (Tuscany, italy)

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    From the Roman times to nowadays the exploitation of natural resources has been of primary importance for the expansion and developments of cities and population in general. As long as for more precious natural materials, like gold and silver, even the exploitation of limestones and other lithotypes of stones for building purposes, as the production of quicklime, hydraulic lime and cements, has covered and still has a great importance (Cantisani et al., 2018; Fratini et al. 1994). The limestone exploitation to produce mortar and concrete in the territories of Florence and Prato has been active in the area from the Roman times (Cantini et al., 2017; Raneri et al., 2018). The main goal of this paper is to characterize the different lithotypes useful to the production of cement and limes for mortar production in this area by mean of chemical, mineralogical and petrographic studies and by defining their physical and mechanical properties. This study analyses stone samples from different quarries, one from the province of Prato, Mt. Calvana, and two quarries from the province of Florence, Settimello and Greve in Chianti. A mapping of these quarries and a comparison between the chemical, mineralogical and petrographic characteristics and physical and mechanical properties of these lithotypes are made

    Septic Shock by Gram-Negative Infections: Role of Outer Membrane Proteins

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    The magnitude of septic shock as a clinical problem is often understated. Despite advances in our ability to diagnose and treat infectious diseases, severe sepsis leading to shock due to gram-negative infections remains one of the leading causes of mortality worldwide. Septic shock develops because of a disregulation in the host response, and the mechanisms initially recruited to fight infection produce life-threatening tissue damage and death. Recent research has witnessed a significant increase in our understanding of host-pathogen interactions, particularly in the area of innate immunity and the molecular recognition of gram-positive and gram-negative bacteria. Important new mediators of sepsis and novel mechanisms of host-cell toxicity have been identified and, together with clinical trials targeting pathways considered central to sepsis pathogenesis, provide new insight into the molecular and cellular basis of sepsis for the formulation of new strategies of intervention. Research on septic shock pathogenesis by gram-negative bacteria is mainly focused on the understanding of the molecular and cellular role played by lipopolysaccharide (LPS). Strong experimental evidence and clinical observations suggest that the release of proinflammatory cytokine mediators by LPS-responsive cells (mainly macrophages, endothelial cells and neutrophils) in response to toxic products sets in motion the genetic and physiologic program that manifests as shock. The best characterized of these toxic components is LPS, which is considered as a paradigm for other less well-characterized toxic microbial molecules. The immune protection stimulated by highly purified LPS in animals does not resolve the symptomatology of septic shock, while LPS mixed to outer membrane proteins shows a better protective activity. Several studies evidence the major role played by outer membrane proteins in the molecular interaction between the host cell and the gram-negative bacteria. Endotoxin-associated proteins consist of a complex of several major proteins that are intimately associated with the LPS. Very little is known about release of non-LPS gramnegative outer membrane components such as OMPs in sepsis. Among the OMPs, porins have been shown to play an important role in pathogenesis of bacterial infections. Porins were pyrogenic in rabbits and elicited a localized reaction when used as the sensiting and eliciting agent. Porins were also shown to kill D-galactosamine sensitized LPS-responsive and LPS-unresponsive mice. Treatment of Human Umbilical Vein Endothelial Cells: (HUVEC) with porins increased the transmigration of different leukocyte populations, inparticular of neutrophils. Porins by several gram-negative bacteria induce cytokine release by human leukocytes as well as enhancement of cytokine gene expression. Also, other components of the bacterial envelope are important in the induction and pathogenesis of septic shock such as bacterial lipoproteins (LP). As anti-LPS therapies does not seem to improve by the addition of proteins from the outer membrane or small fragments of these proteins, a great alternative to existing strategies will involve the blockage of signal transduction pathways, cytokine and inflammatory mechanisms

    Review of a viral peptide nanosystem for intracellular delivery

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    The internalization of bioactive molecules is one of the most critical problems to overcome in theranostics. In order to improve pharmacokinetic and pharmacodynamic proper- ties, synthetic transporters are widely investigated. A new nanotechnological transporter, gH625, is based on a viral peptide sequence derived from the herpes simplex virus type 1 glycoprotein H (gH) that has proved to be a useful delivery vehicle, due to its intrinsic properties of inducing membrane perturbation. The peptide functionalization with several kinds of nanoparticles like quantum dots, dendrimers, and liposomes could be of particular interest in biomedical applica- tions to improve drug release within cells, to increase site-specific action, and eventually to reduce related cytotoxicity. © The Authors. Published by SPIE under a Creative Commons Attribution 3.0 Unported License. Distribution or reproduction of this work in whole or in part requires full attribution of the original publication, including its DOI. (DOI: 10.1117/1.JNP.7.071599

    Mapping key interactions in the dimerization process of HBHA from Mycobacterium tuberculosis, insights into bacterial agglutination

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    AbstractHBHA is a cell-surface protein implicated in the dissemination of Mycobacterium tuberculosis (Mtb) from the site of primary infection. Its N-terminal coiled-coil region is also involved in bacterial agglutination. However, despite the importance of HBHA dimerization in agglutination, protein regions involved in dimerization are hitherto not known. Here, we mapped these regions by coupling peptide synthesis, biochemical and computational analyses, and identified structural determinants for HBHA monomer–monomer recognition. Importantly, we obtained the first molecule able to induce HBHA dimer disaggregation at 37°C, the typical growth temperature of Mtb. This result provides new opportunities towards the development of Mtb anti-aggregation molecules with therapeutic interest.Structured summary of protein interactionsHBHA and HBHA bind by molecular sieving (View interaction)HBHA and H1 peptide bind by competition binding (View Interaction)HBHA and H1ext peptide bind by competition binding (View Interaction)HBHA and H2ext peptide bind by competition binding (View Interaction)HBHA and H2 peptide bind by competition binding (View Interaction)HBHA and H2ext peptide bind by competition binding (View Interaction)HBHA and HBHA bind by blue native page (View interaction

    Viral fusion peptides induce several signal transduction pathway activations that are essential for interleukin-10 and beta-interferon production

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    Objectives: The deciphering of intracellular signaling pathways that are activated by the interaction between viral fusion peptides and cellular membranes are important for the understanding of both viral replication strategies and host defense mechanisms. Methods: Fusion peptides of several enveloped viruses belonging to different virus families were prepared by standard 9-fluorenylmethoxycarbonyl polyamine solid-phase synthesis and used to stimulate U937 cells in vitro to analyze the phosphorylation patterns of the signaling pathways (PKC, Src, Akt, and MAPK pathways). Immunoprecipitation and Western blotting were carried out by using phosphospecific antibodies. All samples were also assayed for the presence of IL-10 and IFN-beta by ELISA and activation of nuclear factors (AP-1 and NF-kappa B). Results: We have demonstrated that hydrophobic domains of fusion proteins are able to induce several transduction pathways that lead to cytokine (IFN-beta and IL-10) production, an event that appears to be dependent on early activation of AP-1 and NF-kappa B. Conclusions: The results obtained on the signaling activity of fusion peptides from different viruses enabled us to shed some light on the complex mechanism of viral entry and more precisely we focused on the exact signaling event induced by hydrophobic domains characteristic of fusion peptides interacting with the cell membrane. Copyright (C) 2010 S. Karger AG, Base

    Reconstruction of the nose. management of nasal cutaneous defects according to aesthetic subunit and defect size. a review

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    The nose represents the most common site for the presentation of cutaneous cancer, especially in sun-exposed areas: ala, dorsum, and tip. Even the smallest loss of substance can create aesthetic and psychosocial concerns for patients; therefore, surgeons who perform nasal reconstruction should be strictly confident with the pertinent surgical anatomy in order to tailor the procedure to the patient's condition and needs. Radical tumor excision and satisfactory aesthetic and functional results are primary targets. Restoring the original shape is the goal of any reconstruction: appropriate reshaping of three-dimensional geometry, proper establishment of symmetry, and excellent color and texture match to the adjacent structures are paramount features. Multiple options exist to re-establish functional and aesthetic integrity after surgical oncology; nevertheless, the management of nasal defects can be often challenging, and the gold standard is yet to be found. The current goal is to highlight some of the more common techniques used to reconstruct cutaneous defects of the nose with a specific focus on decision making based on the aesthetic subunit and defect size. The authors attempt to share common pitfalls and offer practical suggestions that they have found helpful in their clinical experience

    Pelvic pain in reproductive age: US findings

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    Pelvic pain in reproductive age often represents a diagnostic challenge due to the variety of potential causes characterized by overlapping clinical symptoms, including gynecological and other disorders (e.g., entero-colic or urological). It is also necessary to determine if there is a possibility of pregnancy to rule out any related complications, such as ectopic pregnancy. Although ultrasound (US), computed tomography (CT), and magnetic resonance imaging (MRI) are strongly integrated, the choice of which is the ideal diagnostic tool should be guided both by clinical suspicion (gynecological vs. non-gynecological cause) and by the risk ratio-benefit (ionizing radiation and instrumental costs), too. The didactic objective proposed by this review consists in the diagnosis of the cause and differential of pelvic pain in reproductive age by describing and critically analyzing the US diagnostic clues of the most frequent adnexal, uterine, and vascular causes

    Preoperative Multiparametric Ultrasound and Fine Needle Aspiration Cytology evaluation of parotid gland tumors : which is the best technique?

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    Publisher Copyright: © 2021 Societatea Romana de Ultrasonografie in Medicina si Biologie. All rights reserved.AIMS: To evaluate the pre-surgical diagnostic value of Multiparametric Ultrasound (MPUS) and Fine Needle Aspiration Cytology (FNAC) in differentiating parotid gland tumors, comparing the results with histology. MATERIALS AND METHODS: The study enrolled 84 patients with parotid gland lesions surgically treated in a single tertiary center and evaluated by MPUS. Each patient underwent FNAC. Histological examination was considered the gold standard. RESULTS: Histology identified 62 benign tumors and 22 malignancies. In the differential diagnosis between malignant and benign lesions, B-mode Ultrasound (US), Color-Doppler US, Contrast-Enhanced US (CEUS), Elastography (USE) and FNAC showed the following values of sensitivity: 82%, 81%, 86%, 77%, 73% respectively; specificity: 97%, 61%, 95%, 71%, 97% respectively; PPV: 90%, 43%, 86%, 50%, 89% respectively; NPV: 93%, 90%, 95%, 88%, 91% respectively; and accuracy: 89%, 71%, 90%, 78%, 84% re-spectively. CONCLUSIONS: CEUS proved to be a valid and accurate method for identifying malignant tumors of parotid gland; the combination of B-mode US with CEUS showed similar diagnostic accuracy, but better sensitivity than CEUS taken alone. USE did not improve the diagnostic performance of the B-mode US, alone or in association with CEUS; however, it revealed the highest diagnostic accuracy in the differentiation between benign lesions. FNAC demonstrated lower values in comparison with CEUS and with USE. Therefore, according to our study, MPUS could be proposed as a valid alternative to FNAC.publishersversionPeer reviewe

    Lentigo maligna and lentigo maligna melanoma in vivo differentiation with dermoscopy and reflectance confocal microscopy. a retrospective, multicentre study

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    IntroductionDermoscopic predictors of lentigo maligna (LM) and lentigo maligna melanoma (LMM) have been recently reported, but these have not been reported in reflectance confocal microscopy (RCM). Objectives(i) To validate dermoscopic predictors for LM/LMM, (ii) to identify RCM patterns in LM and LMM, and (iii) correlations between dermoscopic and RCM features in LM and LMM. Materials and MethodsA retrospective, multicentre study of consecutive lesions with histologically proven LM or LMM subtypes of the head and face, with complete sets of dermoscopic and RCM images. ResultsA total of 180 lesions were included (n = 40 LMM). Previously reported differential dermoscopic features for LM subtypes were confirmed. Other features significantly associated with LMM diagnosis included irregular hyperpigmented areas, shiny white streaks, atypical vessels and light brown colour at dermoscopy and medusa head-like structures, dermal nests and nucleated cells within the papillae at RCM (p < 0.05). Correlations among LM lesions between dermoscopic and RCM features included brown to-grey dots and atypical cells (epidermis), grey colour and inflammation and obliterated follicles and medusa head-like structures. Among LMM lesions, significant correlations included obliterated follicles with folliculotropism, both irregular hyperpigmented areas and irregular blotches with widespread atypical cell distribution (epidermis), dermal nests and nucleated cells within the papillae (dermis). Irregular blotches were also associated with medusa head-like structures (dermal epidermal junction [DEJ]). ConclusionsDermoscopic and RCM features can assist in the in vivo identification of LM and LMM and many are correlated. RCM three-dimensional analysis of skin layers allows the identification of invasive components in the DEJ and dermis
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