Unterschiede und Gemeinsamkeiten der nicht-kanonischen Wnt-Liganden Wnt5a und Wnt11

Die nicht-kanonischen Zweige des Wnt-Signalnetzwerkes sind Regulatoren der konvergenten Extension während der Xenopus Gastrulation. Dabei übernehmen die nicht-kanonischen Wnt-Liganden Wnt5a und Wnt11 nicht-redundante Aufgaben

Success rate of paramedian palatal implants in adolescent and adult orthodontic patients: a retrospective cohort study

The purpose of this study was to examine the success rate of paramedian palatal Orthosystem first- and second-generation implants used for anchorage in orthodontic treatment in patients treated by one experienced orthodontist. The records of 143 patients (90 female, 53 male, median age: 15.7 years, range: 10.2-50.9) receiving 145 palatal implants of the first or second generation (Orthosystem, Straumann AG, Basel, Switzerland) were examined. All the palatal implants were placed in a paramedian palatal location by three experienced surgeons. Stable implants were orthodontically loaded after a healing period of 3 months. Out of the 145 inserted paramedian palatal implants only seven implants (4.8%) were not considered stable after insertion. All the successfully osseointegrated implants remained stable during orthodontic treatment. Paramedian palatal implants are highly reliable and effective devices to obtain skeletal anchorage for orthodontic treatment. This study has shown that the paramedian location is a good alternative to the median locatio

Immediate versus delayed implant placement after anterior single tooth extraction: the timing randomized controlled clinical trial

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Immediate vs. Delayed Implant Placement after Anterior Single Tooth Extraction: The Timing Randomised Controlled Clinical Trial.

to compare need for bone augmentation, surgical complications, periodontal, radiographic, aesthetic and patient reported outcomes in subjects receiving implant placement at the time of extraction (IMI) or 12 weeks thereafter. METHODS: Subjects requiring single tooth extraction in the anterior and premolar areas were recruited in 7 private practices. Implant position and choice of platform were restoratively driven. Measurements were performed by calibrated and masked examiners. RESULTS: IMI was unfeasible in 7.5% of cases. 124 subjects were randomized. One implant was lost in the IMI group. IMI required bone augmentation in 72% of cases compared with 43.9% for delayed (P=0.01), while wound failure occurred in 26.1% and 5.3% of cases, respectively (P=0.02). At 1 year, IMI had deeper probing depths (4.1±1.2 mm vs. 3.3±1.1 mm, P<0.01). A trend for greater radiographic bone loss was observed at IMI over the initial 3-year period (Ptrend<0.01). Inadequate pink aesthetic scores were obtained in 19% of delayed and in 42% of IMI implant cases (P=0.03). No differences in patient reported outcomes were observed. CONCLUSIONS: Immediate implant placement should not be recommended when aesthetics are important, IMI should be limited to selected cases. Longer follow-up is needed to assess differences in complication rates. This article is protected by copyright. All rights reserved

Microbial colonization patterns predict the outcomes of surgical treatment of infrabony defect

Aim: To explore the impact of bacterial load and microbial colonization patterns on the clinical outcomes of periodontal surgery at deep intrabony defects. Materials and Methods: One hundred and twenty-two patients with advanced chronic periodontitis and at least one intrabony defect of 43mm were recruited in 10 centres. Before recruitment, the infection control phase of periodontal therapy was completed. After surgical access and debridement, the regenerative material was applied in the test subjects, and omitted in the controls. At baseline and 1 year following the interventions, clinical attachment levels (CAL), pocket probing depths (PPD), recession (REC), full-mouth plaque scores and full-mouth bleeding scores were assessed. Microbial colonization of the defect-associated pocket was assessed using a DNA\u2013DNA checkerboard analysis. Results: Total bacterial load and counts of red complex bacteria were negatively associated with CAL gains 1 year following treatment. The probability of achieving above median CAL gains (43 mm) was significantly decreased by higher total bacterial counts, higher red complex and T. forsythensis counts immediately before surgery. Conclusions: Presence of high bacterial load and specific periodontal pathogen complexes in deep periodontal pockets associated with intrabony defects had a significant negative impact on the 1 year outcome of surgical/regenerative treatmen

Live Imaging of Xwnt5A-ROR2 Complexes

Secreted molecules of the Wnt family regulate key decisions in embryogenesis and adult tissue homeostasis by activating a complex network of Wnt signaling pathways. Although the different branches of Wnt signaling have been studied for more than 25 years, fluorophore tagged constructs for live cell imaging of Wnt molecules activating the Wnt/β-catenin pathway have become available only recently. We have generated a fluorophore tagged Wnt construct of the Xenopus Wnt5a protein (Xwnt5A) with the enhanced green fluorescent protein (EGFP), Xwnt5A-EGFP. This construct activates non-canonical Wnt pathways in an endocytosis dependent manner and is capable of compensating for the loss of endogenous Xwnt5A in Xenopus embryos. Strikingly, non-canonical Wnt pathway activation was restricted to short-range signaling while an inhibitory effect was observed in transwell cell cultures taken as long-range signaling model sytem. We used our Xwnt5A-EGFP construct to analyze in vivo binding of Wnt5A to its co-receptor ROR2 on the microscopic and on the molecular level. On the microscopic level, Xwnt5A-EGFP clusters in the membrane and recruits ROR2-mCherry to these clusters. Applying dual-colour dual-focus line-scanning fluorescence correlation spectroscopy on dorsal marginal zone explants, we identified membrane tethered Xwnt5A-EGFP molecules binding to ROR2-mCherry molecules. Our data favour a model, in which membrane-tethered Wnt-5A recruits ROR2 to form large ligand/receptor clusters and signals in an endocytosis-dependent manner

Enamel matrix proteins in the regenerative therapy of deep intrabony defects A multicentre randomized controlled clinical trial

Abstract Aim: This prospective multicentre randomized controlled clinical trial was designed to compare the clinical outcomes of papilla preservation flap surgery with or without the application of enamel matrix proteins (EMD). Material and methods: 172 patients with advanced chronic periodontitis were recruited in 12 centers in 7 countries. All patients had at least one intrabony defect of у3mm. Heavy smokers (у20 cigarettes/day) were excluded. The surgical procedures included access for root instrumentation using either the simplified or the modified papilla preservation flap in order to obtain optimal tissue adaptation and primary closure. After debridement, roots were conditioned for 2 min with a gel containing 24% EDTA. EMD was applied in the test subjects, and omitted in the controls. Postsurgically, a strict plaque control protocol was followed. At baseline and 1 year following the interventions, clinical attachment levels (CAL), pocket probing depths (PPD), recession (REC), full-mouth plaque scores and full-mouth bleeding scores were assessed. A total of 166 patients were available for the 1-year follow-up

Wnt/PCP controls spreading of Wnt/β-catenin signals by cytonemes in vertebrates

This is the author accepted manuscript.The final version is available from eLife Sciences Publications via the DOI in this record.Signaling filopodia, termed cytonemes, are dynamic actin-based membrane structures that regulate the exchange of signaling molecules and their receptors within tissues. However, how cytoneme formation is regulated remains unclear. Here, we show that Wnt/PCP autocrine signaling controls the emergence of cytonemes, and that cytonemes subsequently control paracrine Wnt/β-catenin signal activation. Upon binding of the Wnt family member Wnt8a, the receptor tyrosine kinase Ror2 gets activated. Ror2/PCP signaling leads to induction of cytonemes, which mediate transport of Wnt8a to neighboring cells. In the Wnt receiving cells, Wnt8a on cytonemes triggers Wnt/β-catenin-dependent gene transcription and proliferation. We show that cytoneme-based Wnt transport operates in diverse processes, including zebrafish development, the murine intestinal crypt, and human cancer organoids, demonstrating that Wnt transport by cytonemes and its control via the Ror2 pathway is highly conserved in vertebrates.This project was funded by the Living Systems Institute, the University of Exeter and the Boehringer Ingelheim Foundation to SS. Studies in the DMV lab are supported by the National Research Foundation of Singapore and National Medical Research Council under its STAR Award Program. JR and AS were supported by the Impuls- und Vernetzungsfond of the Helmholtz Association. GUN was funded by the Deutsche Forschungsgemeinschaft (SFB 1324, projects A6 and Z2, GRK2039) and Helmholtz Association Program STN

The significance of angiogenesis in guided bone regeneration: A case report of a rabbit experiment

A dome-shaped bioresorbable membrane was fixed to the wounded rabbit calvaria and filled with a bioresorbable fibre conglomerate. After 4 weeks, the histologic preparation revealed an intimate spatial and temporal correlation between newly formed blood vessels and de novo extraskeletal bone formation. These observations emphasize the significance of angiogenesis in guided bone generation. © Munksgaard 1997.link_to_subscribed_fulltex