Severity: Warning
Message: file_get_contents(https://...@gmail.com&api_key=61f08fa0b96a73de8c900d749fcb997acc09): Failed to open stream: HTTP request failed! HTTP/1.1 429 Too Many Requests
Filename: helpers/my_audit_helper.php
Line Number: 143
Backtrace:
File: /var/www/html/application/helpers/my_audit_helper.php
Line: 143
Function: file_get_contents
File: /var/www/html/application/helpers/my_audit_helper.php
Line: 209
Function: simplexml_load_file_from_url
File: /var/www/html/application/helpers/my_audit_helper.php
Line: 994
Function: getPubMedXML
File: /var/www/html/application/helpers/my_audit_helper.php
Line: 3134
Function: GetPubMedArticleOutput_2016
File: /var/www/html/application/controllers/Detail.php
Line: 574
Function: pubMedSearch_Global
File: /var/www/html/application/controllers/Detail.php
Line: 488
Function: pubMedGetRelatedKeyword
File: /var/www/html/index.php
Line: 316
Function: require_once
Introduction: The present study investigated whether bacteria infecting the root canal can activate any infiltrating T cells to produce receptor activator of nuclear factor kappa B (NF-κB) ligand (RANKL).
Methods: Using a mouse model of periapical lesion induced by artificial dental pulp exposure, the presence of RANKL-positive T cells and osteoclasts in the periapical lesion was examined by an immunohistochemical approach. The bacteria colonizing the exposed root canal were identified by 16S ribosomal RNA (rRNA) sequence analysis. The isolated endodontic bacteria were further immunized to normal mice, and soluble activator of NF-κB ligand (sRANKL) production by the T cells isolated from the immunized mice was evaluated by ex vivo culture system.
Results: RANKL-positive T cells along with TRAP+ osteoclasts were identified in periapical bone resorption lesions. The gram-negative bacterium Pasteurella pnumotropica, which was most frequently detected from the root canal of exposed pulp, showed remarkably elevated serum immunoglobulin G (IgG)-antibody response in pulp-exposed mice compared with control nontreated mice. Immunization of mice with P. pneumotropica induced not only serum IgG-antibody but also primed bacteria-reactive T cells that produced sRANKL in response to ex vivo exposure to P. pneumotropica.
Conclusions: T cells infiltrating the periapical region express RANKL, and the endodontic bacteria colonizing the root canal appear to induce RANKL expression from bacteria-reactive T cells, suggesting the possible pathogenic engagement of the immune response to endodontic bacteria in the context of developing bone resorptive periapical lesions.
Download full-text PDF |
Source |
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http://www.ncbi.nlm.nih.gov/pmc/articles/PMC3291477 | PMC |
http://dx.doi.org/10.1016/j.joen.2011.12.029 | DOI Listing |
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