Distribution of P.gingivalis fimA genotypes in individuals with cardiovascular risk

Objectives: Porphyromonas gingivalis has been associated with both periodontitis and cardiovascular disease. Filamentous components on P. gingivalis cell surfaces (fimA) play an important role in the colonization and invasion of host cells. In this study, P.gingivalis fimA genotypic distribution was analysed in dental plaque specimens from high and low cardiovascular (CV) risk patients in an Australian population. Methods: Patients were retrospectively selected from an existing longitudinal study. A total of 90 patients with P.gingivalis positive plaque samples were selected according to CV-risk (≥6 classical risk factors=high CV-risk, n=48; ≤1 classical risk factor=low CV-risk, n=42) and periodontal status (≥6 sites with ≥4mm periodontal probing depth (PPD)=periodontitis, n=42; ≤1 site with ≥4mm PPD=periodontal health, n=48). The plaque specimens were analysed to discriminate the fimA genotype using conventional polymerase chain reaction with fimA type-specific primer sets. Results: The distribution of fimA genotypes was similar in periodontally healthy individuals irrespective of their CV-risk group. In contrast, the prevalence of the type II, type IV and type 1b virulent fimA genotypes was greater in periodontitis patients with high CV-risk than in periodontitis patients with low CV-risk. The virulent type II fimA genotype had the highest prevalence in high CV-risk periodontitis patients (40%) and was 8 times greater than in low CV-risk periodontitis patients. The non-virulent type III fimA genotype was most prevalent in low CV-risk periodontitis patients (27%). Conclusions: The results of this study indicate that virulent fimA genotypes occurred more frequently in patients with an increased risk of developing CVD, suggesting that the presence of specific fimA genotypes in dental plaque is associated with an increased risk of developing CVD. Acknowledgements: This study was supported by unrestricted grants from National Health and Medical Research Council, HCF Health and Medical Research Foundation, Australian Dental Research Foundation and Queensland Health

Improvement in periodontal health and systemic markers of inflammation

The relationship between periodontal disease, systemic inflammation and atherosclerosis is complex. Chronic periodontal infections are known to elevate systemic levels of inflammatory mediators. It has been proposed that this may lead to endothelial cell activation and atherogenesis. Objectives: To examine changes in serum levels of inflammatory mediators following improvement in periodontal health in patients with cardiovascular disease (CVD) and in patients with high cardiovascular (CV) risk and low CV risk. Methods: Patients were selected from two longitudinal studies and had undergone yearly periodontal examinations and peripheral blood collections. CVD patients selected from one study had experienced a significant CV event (myocardial infarct or unstable angina requiring hospitalisation) while patients derived from the other study had not. These latter patients were further classified according to CV risk (6 classical risk factors=high CV risk; 1 classical risk factor=low CV risk). Patients demonstrating a quantifiable improvement in periodontal health (62% reduction in number of sites with probing depth4mm) from the baseline visit were selected. Commercial high sensitivity ELISA kits were used to measure serum levels of soluble intercellular adhesion molecule-1 (sICAM-1), IL-6, IL-1 and tumour necrosis factor- in CVD patients (n=8), high CV risk (n=18) and low CV risk (n=14) patients. Results: Improved periodontal health resulted in reductions in mean levels of the four inflammatory markers in patients with CVD. Reductions in sICAM-1 levels following improved periodontal health reached significance in CVD (

Relationship between periodontal infections and systemic disease

Oral conditions such as gingivitis and chronic periodontitis are found worldwide and are among the most prevalent microbial diseases of mankind. The cause of these common inflammatory conditions is the complex microbiota found as dental plaque, a complex microbial biofilm. Despite 3000 years of history demonstrating the influence of oral status on general health, it is only in recent decades that the association between periodontal diseases and systemic conditions such as coronary heart disease and stroke, and a higher risk of preterm low birth-weight babies, has been realised. Similarly, recognition of the threats posed by periodontal diseases to individuals with chronic diseases such as diabetes, respiratory diseases and osteoporosis is relatively recent. Despite these epidemiological associations, the mechanisms for the various relationships remain unknown. Nevertheless, a number of hypotheses have been postulated, including common susceptibility, systemic inflammation with increased circulating cytokines and mediators, direct infection and cross-reactivity or molecular mimicry between bacterial antigens and self-antigens. With respect to the latter, cross-reactive antibodies and T-cells between self heat-shock proteins (HSPs) and Porphyromonas gingivalis GroEL have been demonstrated in the peripheral blood of patients with atherosclerosis as well as in the atherosclerotic plaques themselves. In addition, P. gingivalis infection has been shown to enhance the development and progression of atherosclerosis in apoE-deficient mice. From these data, it is clear that oral infection may represent a significant risk-factor for systemic diseases, and hence the control of oral disease is essential in the prevention and management of these systemic conditions

A review of morphing aircraft

Aircraft wings are a compromise that allows the aircraft to fly at a range of flight conditions, but the performance at each condition is sub-optimal. The ability of a wing surface to change its geometry during flight has interested researchers and designers over the years as this reduces the design compromises required. Morphing is short for metamorphose: however, there is neither an exact definition nor an agreement between the researchers about the type or the extent of the geometrical changes necessary to qualify an aircraft for the title “shape morphing”. Geometrical parameters that can be affected by morphing solutions can be categorized into: planform alteration (span, sweep and chord), out-of-plane transformation (twist, dihedral/gull, spanwise bending) and airfoil adjustment (camber and thickness).Changing the wing shape or geometry is not new. Historically, morphing solutions always led to penalties in terms of cost, complexity or weight, although in certain circumstances these were overcome by system level benefits. The current trend for highly efficient and “green” aircraft makes such compromises less acceptable, calling for innovative morphing designs able to provide more benefits and fewer drawbacks. Recent developments in “smart” materials may overcome the limitations and enhance the benefits from existing design solutions. The challenge is to design a structure that is capable of withstanding the prescribed loads, but is also able to change its shape: ideally there should be no distinction between the structure and the actuation system. The blending of morphing and smart structures in an integrated approach requires multi-disciplinary thinking from the early development, which significantly increases the overall complexity, even at the preliminary design stage. Morphing is a promising enabling technology for future, next generation aircraft. However, manufacturers and end users are still too skeptical of the benefits to adopt morphing in the near future. Many developed concepts have a technology readiness level that is still very low. The recent explosive growth of satellite services means that UAVs are the technology of choice for many investigations on wing morphing.This paper presents a review of the state of the art on morphing aircraft and focuses on structural, shape changing morphing concepts for both fixed and rotary wings, with particular reference to active systems. Inflatable solutions have been not considered, and skin issues and challenges are not discussed in detail. Although many interesting concepts have been synthesized, few have progressed to wing tunnel testing, and even fewer have flown. Furthermore, any successful wing morphing system must overcome the weight penalty due to the additional actuation systems.<br/