Periodontal Inflammation Primes the Systemic Innate Immune Response.

The presence of periodontal diseases (PDs) often strongly correlates with other severe chronic inflammatory conditions, including cardiovascular disease, diabetes, and arthritis. However, the mechanisms through which these diseases interact are unclear. In PD, tissue and bone destruction in the mouth is driven by elevated recruitment of polymorphonuclear neutrophils (PMNs), which are primed and recruited from the circulation to sites of inflammation. We predicted that systemic effects on PMN mobilization or priming could account for the interaction between PD and other inflammatory conditions. We tested this using a mouse model of ligature-induced PD and found elevated PMN counts specifically in bone marrow, supporting a systemic effect of periodontal tissue inflammation on PMN production. In contrast, mice with induced peritonitis had elevated PMN counts in the blood, peritoneum, and colon. These elevated counts were further significantly increased when acute peritonitis was induced after ligature-induced PD in mice, revealing a synergistic effect of multiple inflammatory events on PMN levels. Flow cytometric analysis of CD marker expression revealed enhanced priming of PMNs from mice with both PD and peritonitis compared to mice with peritonitis alone. Thus, systemic factors associated with PD produce hyperinflammatory PMN responses during a secondary infection. To analyze this systemic effect in humans, we induced gingival inflammation in volunteers and also found significantly increased activation of blood PMNs in response to ex vivo stimulation, which reverted to normal following resolution of gingivitis. Together, these results demonstrate that periodontal tissue inflammation has systemic effects that predispose toward an exacerbated innate immune response. This indicates that peripheral PMNs can respond synergistically to simultaneous and remote inflammatory triggers and therefore contribute to the interaction between PD and other inflammatory conditions. This suggests larger implications of PD beyond oral health and reveals potential new approaches for treating systemic inflammatory diseases that interact with PD.

Clinical and radiographic features of solitary and cemento-osseous dysplasia-associated simple bone cysts.

UNLABELLED: The simple bone cyst (SBC) is a pseudocyst that can occur as a solitary entity in the jaws or may occur in association with cemento-osseous dysplasia (COD). OBJECTIVE: The purpose of this study was to review the clinical and radiographic features of solitary and COD-associated SBCs. METHODS: Archived imaging reports from the Special Procedures Clinic in Oral and Maxillofacial Radiology at the Faculty of Dentistry at the University of Toronto between 1 January 1989 and 31 December 2009 revealed 23 COD-associated SBCs and 68 solitary SBCs. RESULTS: Almost all solitary and COD-associated SBCs were found in the mandible. Furthermore, 87.0% of COD-associated SBCs were found in females in their fifth decade of life (P < 0.001) while solitary SBCs were found in equal numbers in both sexes in their second decade of life (P < 0.005). COD-associated SBCs were also more likely to cause thinning of the endosteal cortex, bone expansion and scalloping of the superior border between teeth (all P < 0.001) than solitary SBCs that are classically described as having these characteristics. Finally, COD-associated SBC demonstrated a loss of lamina dura more often (P < 0.05) than solitary SBCs. CONCLUSIONS: Knowledge of the sporadic association between COD and SBC and their potential radiographic appearances should prevent inappropriate treatment and management of these patients.

Decomposition and arthropod succession on exposed rabbit carrion during summer at high altitudes in Colorado, USA.

Six rabbit carcasses were exposed during summer at elevations ranging from 2,713 to 4,191 m in Colorado to determine decomposition rates and arthropod succession patterns. Biomass removal, bloat, and internal and ambient air temperatures were measured and the arthropod community was monitored during 51-d succession studies. A total of 53 taxa was collected (range, 8-36 taxa), with diversity apparently decreasing as a negative function of elevation. Extensive scavenging altered decomposition rates and arthropod succession. Rates and duration of biomass removal and bloating of carcasses were slowed and prolonged at higher elevations.