43 research outputs found
Evaluation of Colloids and Activation Agents for Determination of Melamine Using UV-SERS
UV-SERS measurements offer a great potential for environmental or food (detection of food contaminats) analytics. Here, the UV-SERS enhancement potential of various kinds of metal colloids, such as Pd, Pt, Au, Ag, Au-Ag core-shell, and Ag-Au core-shell with different shapes and sizes, were studied using melamine as a test molecule. The influence of different activation (KF, KCl, KBr, K 2SO 4) agents onto the SERS activity of the nanomaterials was investigated, showing that the combination of a particular nanoparticle with a special activation agent is extremely crucial for the observed SERS enhancement. In particular, the size dependence of spherical nanoparticles of one particular metal on the activator has been exploited. By doing so, it could be shown that the SERS enhancement increases or decreases for increasing or decreasing size of a nanoparticle, respectively. Overall, the presented results demonstrate the necessity to adjust the nanoparticle size and the activation agent for different experiments in order to achieve the best possible UV-SERS results
Isolation and characterisation of human gingival margin-derived STRO-1/MACS+ and MACS− cell populations
Recently, gingival margin-derived stem/progenitor cells isolated via
STRO-1/magnetic activated cell sorting (MACS) showed remarkable periodontal
regenerative potential in vivo. As a second-stage investigation, the present
study's aim was to perform in vitro characterisation and comparison of the
stem/progenitor cell characteristics of sorted STRO-1-positive (MACS+) and
STRO-1-negative (MACS−) cell populations from the human free gingival margin.
Cells were isolated from the free gingiva using a minimally invasive technique
and were magnetically sorted using anti-STRO-1 antibodies. Subsequently, the
MACS+ and MACS− cell fractions were characterized by flow cytometry for
expression of CD14, CD34, CD45, CD73, CD90, CD105, CD146/MUC18 and STRO-1.
Colony-forming unit (CFU) and multilineage differentiation potential were
assayed for both cell fractions. Mineralisation marker expression was examined
using real-time polymerase chain reaction (PCR). MACS+ and MACS− cell
fractions showed plastic adherence. MACS+ cells, in contrast to MACS− cells,
showed all of the predefined mesenchymal stem/progenitor cell characteristics
and a significantly higher number of CFUs (P<0.01). More than 95% of MACS+
cells expressed CD105, CD90 and CD73; lacked the haematopoietic markers CD45,
CD34 and CD14, and expressed STRO-1 and CD146/MUC18. MACS− cells showed a
different surface marker expression profile, with almost no expression of CD14
or STRO-1, and more than 95% of these cells expressed CD73, CD90 and
CD146/MUC18, as well as the haematopoietic markers CD34 and CD45 and CD105.
MACS+ cells could be differentiated along osteoblastic, adipocytic and
chondroblastic lineages. In contrast, MACS− cells demonstrated slight
osteogenic potential. Unstimulated MACS+ cells showed significantly higher
expression of collagen I (P<0.05) and collagen III (P<0.01), whereas MACS−
cells demonstrated higher expression of osteonectin (P<0.05; Mann–Whitney).
The present study is the first to compare gingival MACS+ and MACS− cell
populations demonstrating that MACS+ cells, in contrast to MACS− cells,
harbour stem/progenitor cell characteristics. This study also validates the
effectiveness of the STRO-1/MACS+ technique for the isolation of gingival
stem/progenitor cells. Human free gingival margin-derived STRO-1/MACS+ cells
are a unique renewable source of multipotent stem/progenitor cells
Treatment of stage I-III periodontitis-The EFP S3 level clinical practice guideline
Background: The recently introduced 2017 World Workshop on the classification of periodontitis, incorporating stages and grades of disease, aims to link disease classification with approaches to prevention and treatment, as it describes not only disease severity and extent but also the degree of complexity and an individual's risk. There is, therefore, a need for evidence-based clinical guidelines providing recommendations to treat periodontitis. Aim: The objective of the current project was to develop a S3 Level Clinical Practice Guideline (CPG) for the treatment of Stage I–III periodontitis. Material and Methods: This S3 CPG was developed under the auspices of the European Federation of Periodontology (EFP), following the methodological guidance of the Association of Scientific Medical Societies in Germany and the Grading of Recommendations Assessment, Development and Evaluation (GRADE). The rigorous and transparent process included synthesis of relevant research in 15 specifically commissioned systematic reviews, evaluation of the quality and strength of evidence, the formulation of specific recommendations and consensus, on those recommendations, by leading experts and a broad base of stakeholders. Results: The S3 CPG approaches the treatment of periodontitis (stages I, II and III) using a pre-established stepwise approach to therapy that, depending on the disease stage, should be incremental, each including different interventions. Consensus was achieved on recommendations covering different interventions, aimed at (a) behavioural changes, supragingival biofilm, gingival inflammation and risk factor control; (b) supra- and sub-gingival instrumentation, with and without adjunctive therapies; (c) different types of periodontal surgical interventions; and (d) the necessary supportive periodontal care to extend benefits over time. Conclusion: This S3 guideline informs clinical practice, health systems, policymakers and, indirectly, the public on the available and most effective modalities to treat periodontitis and to maintain a healthy dentition for a lifetime, according to the available evidence at the time of publication