Interaction of periodontitis and orthodontic tooth movement-an in vitro and in vivo study.

OBJECTIVES The aim of this in vitro and in vivo study was to investigate the interaction of periodontitis and orthodontic tooth movement on interleukin (IL)-6 and C-X-C motif chemokine 2 (CXCL2). MATERIALS AND METHODS The effect of periodontitis and/or orthodontic tooth movement (OTM) on alveolar bone and gingival IL-6 and CXCL2 expressions was studied in rats by histology and RT-PCR, respectively. The animals were assigned to four groups (control, periodontitis, OTM, and combination of periodontitis and OTM). The IL-6 and CXCL2 levels were also studied in human gingival biopsies from periodontally healthy and periodontitis subjects by RT-PCR and immunohistochemistry. Additionally, the synthesis of IL-6 and CXCL2 in response to the periodontopathogen Fusobacterium nucleatum and/or mechanical strain was studied in periodontal fibroblasts by RT-PCR and ELISA. RESULTS Periodontitis caused an increase in gingival levels of IL-6 and CXCL2 in the animal model. Moreover, orthodontic tooth movement further enhanced the bacteria-induced periodontal destruction and gingival IL-6 gene expression. Elevated IL-6 and CXCL2 gingival levels were also found in human periodontitis. Furthermore, mechanical strain increased the stimulatory effect of F. nucleatum on IL-6 protein in vitro. CONCLUSIONS Our study suggests that orthodontic tooth movement can enhance bacteria-induced periodontal inflammation and thus destruction and that IL-6 may play a pivotal role in this process. CLINICAL RELEVANCE Orthodontic tooth movement should only be performed after periodontal therapy. In case of periodontitis relapse, orthodontic therapy should be suspended until the periodontal inflammation has been successfully treated and thus the periodontal disease is controlled again

Effect of Bacterial Infection on Ghrelin Receptor Regulation in Periodontal Cells and Tissues.

The effect of bacterial infection on the expression of growth hormone secretagogue receptor (GHS-R) was investigated in periodontal cells and tissues, and the actions of ghrelin were evaluated. GHS-R was assessed in periodontal tissues of rats with and without periodontitis. Human gingival fibroblasts (HGFs) were exposed to Fusobacterium nucleatum in the presence and absence of ghrelin. GHS-R expression was determined by real-time PCR and immunocytochemistry. Furthermore, wound healing, cell viability, proliferation, and migration were evaluated. GHS-R expression was significantly higher at periodontitis sites as compared to healthy sites in rat tissues. F. nucleatum significantly increased the GHS-R expression and protein level in HGFs. Moreover, ghrelin significantly abrogated the stimulatory effects of F. nucleatum on CCL2 and IL-6 expressions in HGFs and did not affect cell viability and proliferation significantly. Ghrelin stimulated while F. nucleatum decreased wound closure, probably due to reduced cell migration. Our results show original evidence that bacterial infection upregulates GHS-R in rat periodontal tissues and HGFs. Moreover, our study shows that ghrelin inhibited the proinflammatory actions of F. nucleatum on HGFs without interfering with cell viability and proliferation, suggesting that ghrelin and its receptor may act as a protective molecule during bacterial infection on periodontal cells

Regulation of NAMPT in Human Gingival Fibroblasts and Biopsies

Adipokines, such as nicotinamide phosphoribosyltransferase (NAMPT), are molecules, which are produced in adipose tissue. Recent studies suggest that NAMPT might also be produced in the tooth-supporting tissues, that is, periodontium, which also includes the gingiva. The aim of this study was to examine if and under what conditions NAMPT is produced in gingival fibroblasts and biopsies from healthy and inflamed gingiva. Gingival fibroblasts produced constitutively NAMPT, and this synthesis was significantly increased by interleukin-1β and the oral bacteria P. gingivalis and F. nucleatum. Inhibition of the MEK1/2 and NFκB pathways abrogated the stimulatory effects of F. nucleatum on NAMPT. Furthermore, the expression and protein levels of NAMPT were significantly enhanced in gingival biopsies from patients with periodontitis, a chronic inflammatory infectious disease of the periodontium, as compared to gingiva from periodontally healthy individuals. In summary, the present study provides original evidence that gingival fibroblasts produce NAMPT and that this synthesis is increased under inflammatory and infectious conditions. Local synthesis of NAMPT in the inflamed gingiva may contribute to the enhanced gingival and serum levels of NAMPT, as observed in periodontitis patients. Moreover, local production of NAMPT by gingival fibroblasts may represent a possible mechanism whereby periodontitis may impact on systemic diseases

Regulation of Ghrelin Receptor by Periodontal Bacteria In Vitro

Ghrelin plays a major role in obesity-related diseases which have been shown to be associated with periodontitis. This study sought to analyze the expression of the functional receptor for ghrelin (GHS-R1a) in periodontal cells and tissues under microbial conditions in vitro and in vivo. The GHS-R1a expression in human periodontal cells challenged with the periodontopathogen Fusobacterium nucleatum, in gingival biopsies from periodontally healthy and diseased individuals, and from rats with and without ligature-induced periodontitis was analyzed by real-time PCR, immunocytochemistry, and immunofluorescence. F. nucleatum induced an initial upregulation and subsequent downregulation of GHS-R1a in periodontal cells. In rat experimental periodontitis, the GHS-R1a expression at periodontitis sites was increased during the early stage of periodontitis, but significantly reduced afterwards, when compared with healthy sites. In human gingival biopsies, periodontally diseased sites showed a significantly lower GHS-R1a expression than the healthy sites. The expression of the functional ghrelin receptor in periodontal cells and tissues is modulated by periodontal bacteria. Due to the downregulation of the functional ghrelin receptor by long-term exposure to periodontal bacteria, the anti-inflammatory actions of ghrelin may be diminished in chronic periodontal infections, which could lead to an enhanced periodontal inflammation and tissue destruction

The Science of Marine Protected Areas (3rd edition, Mediterranean)

The main purpose of the booklet is to present the latest scientific information about the effects of MPAs in the Mediterranean in order to inform current management dialogues. This is particularly relevant given the increasing legislative frameworks and political initiatives to implement networks of MPAs in countries across the Mediterranean Sea. Importantly, this Edition does much more than simply tailor the earlier content for the Mediterranean region. The edition update the basic content of the booklet, drawing on the wealth of new published scientific literature, highlighting case studies from the Mediterranean Sea

Political travel across the ‘Iron Curtain’ and Communist youth identities in West Germany and Greece in the 1970s and 1980s

This article explores tours through the Iron Curtain arranged by West German and Greek pro-Soviet Communist youth groups, in an attempt to shed light on the transformation of European youth cultures beyond the ‘Americanisation’ story. It argues that the concept of the ‘black box’, employed by Rob Kroes to describe the influence of American cultural patterns on Western European youth, also applies to the reception of Eastern Bloc policies and norms by the Communists under study. Such selective reception was part of these groups’ efforts to devise a modernity alternative to the ‘capitalist’ one, an alternative modernity which tours across the Iron Curtain would help establish. Nevertheless, the organisers did not wish such travel to help eliminate American/Western influences on youth lifestyles entirely: the article analyses the excursions’ aims with regard to two core components of youth lifestyles in Western Europe since the 1960s, which have been affected by intra-Western flows, the spirit of ‘doing one’s own thing’ and transformations of sexual practices. The article also addresses the experience of the travellers in question, showing that they felt an unresolved tension: the tours neither served as a means of Sovietisation nor as an impulse to develop an openly anti-Soviet stance.PostprintPeer reviewe

Ancient Greek vase painting as a museum exhibit: from gaze to meaning

The thesis defines three objectives: the comparative study of representative examples of vase painting exhibitions in archaeological museums, the investigation of the factors which shape the visitors’ experience, and the comparative study of the visitors’ perception of ancient Greek vase painting. The purpose of the study is to establish whether the art of vase painting through the museum practice functions as a carrier of knowledge and transmission of information about the ancient world. Cases of permanent exhibitions in museums in Greece and abroad were selected as well as an example of a temporary exhibition where the vases play a leading role in presenting the subject matter. Based on the objectives, there were two research questions. First, what are the main characteristics of representative examples of pottery displays in archaeological museums? Second, what are the factors that shape the visitor experience and to what extent are they successful? In order to answer these questions, a literature review was conducted, in order to examine the interpretation of vase painting, as well as the museum practices to understand the particularities of these archaeological remains. On a theoretical level, it was considered appropriate to examine theories from the fields of neuroscience, the physiology of vision, and visual perception. For the examination of the case studies, the model of F. Monti and S. Keene as described in “Museums and Silent Objects: Designing Effective Exhibitions” was chosen because it facilitates the comparison of different approaches to a subject matter. The model was adapted to the objectives and the present research as well as the characteristics of archaeological museums. Specifically, the case studies were examined through the lens of architecture, space syntax, aesthetics and usability, museology, the use of new technologies, and the educations role of a museum exhibition. For the analysis, both the opinions of museum curators and the experience of visitors was studied. Semi-structured interviews with curators of the selected museums were carried out, based on questionnaires designed for this research, as well as visitor survey of the National Archaeological Museum, the Cycladic Art Museum, and an online survey of the visitors of the temporary exhibition “Troy: myth and reality”. The study reaches certain conclusions based on which proposals are formulated for the improvement of exhibitions of ancient Greek pottery with an aim to harmonize the interpretation with current museological trends and enriching the visitor experience inside and outside of the museum.Η παρούσα μελέτη θέτει τρεις στόχους: τη συγκριτική μελέτη αντιπροσωπευτικών παραδειγμάτων εκθέσεων αγγειογραφίας σε αρχαιολογικά μουσεία, τη διερεύνηση των παραγόντων που διαμορφώνουν την εμπειρία των επισκεπτών, και τη συγκριτική εξέταση της εμπειρίας επισκεπτών στην πρόσληψη της αρχαίας ελληνικής τέχνης της αγγειογραφίας. Απώτερος σκοπός της μελέτης είναι να διαπιστώσει κατά πόσον η τέχνη της αγγειογραφίας μέσω της μουσειακής πράξης λειτουργεί ως φορέας γνώσης και μετάδοσης πληροφοριών για όψεις του αρχαίου κόσμου. Για τους παραπάνω στόχους επιλέχθηκαν περιπτώσεις μόνιμων εκθέσεων σε μουσεία της Ελλάδας και του εξωτερικού με κριτήρια να είναι μουσεία διαφορετικής κατηγορίας και συλλογής και να παρουσιάζουν ομοιότητες αλλά και διαφορές ως προς την παρουσίαση της συλλογής αγγείων, καθώς και ένα παράδειγμα περιοδικής έκθεσης όπου τα αγγεία διαδραματίζουν πρωταγωνιστικό ρόλο στην διαπραγμάτευση του θέματος της έκθεσης. Συγκεκριμένα, τις μελέτες περίπτωσης αποτέλεσαν η μόνιμη έκθεση αρχαίων ελληνικών αγγείων στο Εθνικό Αρχαιολογικό Μουσείο της Αθήνας, η μόνιμη έκθεση Σκηνές από την Καθημερινή Ζωή στην Αρχαιότητα στο Μουσείο Κυκλαδικής Τέχνης, οι μόνιμες εκθέσεις αγγείων στο Εθνικό Αρχαιολογικό Μουσείο της Φλωρεντίας και το Μητροπολιτικό Μουσείο Τέχνης της Νέας Υόρκης, και, τέλος, η περιοδική έκθεση Troy: myth and reality που πραγματοποιήθηκε στο Βρετανικό Μουσείο από 21/10/2019 έως 8/05/2020.Με βάση τους στόχους τέθηκαν δύο ερευνητικά ερωτήματα. Πρώτον, ποια είναι τα κύρια χαρακτηριστικά αντιπροσωπευτικών παραδειγμάτων εκθέσεων αγγείων σε αρχαιολογικά μουσεία; Δεύτερον, ποιοι είναι οι παράγοντες που διαμορφώνουν την εμπειρία του επισκέπτη και σε ποιον βαθμό το επιτυγχάνουν; Για την απάντηση των ερωτημάτων αυτών πραγματοποιήθηκε αρχικά βιβλιογραφική έρευνα, προκειμένου να εξεταστεί ο τρόπος ερμηνείας της τέχνης της αγγειογραφίας, αλλά και των μουσειακών πρακτικών ώστε να κατανοηθούν οι ιδιαιτερότητες του συγκεκριμένου αρχαιολογικού καταλοίπου. Σε θεωρητικό επίπεδο αναζητήθηκαν αρχικά οι προσεγγίσεις και οι θεωρίες που διατυπώθηκαν για την προσέγγιση και ερμηνεία της αρχαίας ελληνικής αγγειογραφίας από τον 13ο έως τις μέρες μας. Στη θεωρητική προσέγγιση κρίθηκε σκόπιμο να εξεταστούν και θεωρίες από τον χώρο των νευροεπιστημών, της φυσιολογίας της όρασης, και της οπτικής αντίληψης.Για την εξέταση των επιλεγμένων μουσειακών παραδειγμάτων επιλέχθηκε το μοντέλο ανάλυσης εκθέσεων των F. Monti και S. Keene Museums and Silent Objects: Designing Effective Exhibitions (2013) διότι διευκολύνει τη σύγκριση των διαφορετικών προσεγγίσεων στην παρουσίαση των εκθεμάτων. Το μοντέλο προσαρμόστηκε στους στόχους της παρούσας έρευνας και τα χαρακτηριστικά των αρχαιολογικών μουσείων, καθώς και τη σχετική με αυτά βιβλιογραφία. Ειδικότερα, οι εκθέσεις εξετάζονται μέσα από το πρίσμα της αρχιτεκτονικής, της συντακτικής θεωρίας του χώρου, του σχεδιασμού, της αισθητικής και της χρηστικότητας, της μουσειολογίας (βιογραφία των αντικειμένων, εμβληματικά αντικείμενα, επίπεδα ερμηνείας), τη χρήση νέων τεχνολογιών εντός και εκτός της έκθεσης, και του εκπαιδευτικού ρόλου της έκθεσης.Για την ανάλυση και συγκριτική μελέτη τόσο των απόψεων των επιμελητών των μουσείων όσο και της εμπειρίας των επισκεπτών πραγματοποιήθηκαν, βάσει ερωτηματολογίων που σχεδιάστηκαν για αυτήν την έρευνα, ημιδομημένες συνεντεύξεις με επιμελητές και υπευθύνους των επιλεγμένων μουσείων, καθώς και έρευνα κοινού στην μόνιμη έκθεση της Συλλογής Αγγείων στο Εθνικό Αρχαιολογικό Μουσείο, το Μουσείο Κυκλαδικής Τέχνης, και διαδικτυακή έρευνα κοινού στην περιοδική έκθεση Troy: myth and reality.Η έρευνα μέσα από την εξέταση των παραδειγμάτων και τα αποτελέσματα της έρευνας κοινού καταλήγει σε ορισμένα συμπεράσματα βάσει των οποίων διατυπώνονται προτάσεις για την βελτίωση των εκθέσεων της τέχνης της αγγειογραφίας και των ερμηνευτικών μέσων με στόχο την εναρμόνιση τους με τις σύγχρονες μουσειολογικές τάσεις και την ψηφιακή πραγματικότητα, την προσέλκυση επισκεπτών και την αναβάθμιση της εμπειρίας τους εντός και εκτός μουσείου