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Oral Microorganisms (oral + microorganism)
Selected AbstractsHow does the periapical inflammatory process compromise general health?ENDODONTIC TOPICS, Issue 1 2004Idikó. Several lines of evidence support the causative role of oral inflammatory lesions and certain systemic diseases, such as atherosclerosis and cardiovascular diseases, adverse pregnancy outcome and lung diseases. Properly executed epidemiologic studies identified increased odds ratios. Local or metastatic spread of oral microorganisms, local production of microbial or host-derived soluble regulatory molecules, that may initiate or sustain inflammatory events in remote tissues and organs and the presence of (a) common , extrinsic- or intrinsic-pathological mechanism(s) may result in or contribute to both local and systemic inflammation. A number of cross-sectional studies addressing a possible association between oral health and systemic diseases have also investigated the presence or the absence of periapical lesions. However, these studies cannot either confirm or refute a role of the periapical inflammatory lesion in the observed associations, since other variables of oral health might have exerted an inestimable influence on general health of the assessed population. The literature, dealing with patients with root canal infections and apical periodontitis as sole oral inflammatory lesions is extremely sparse. Our group has demonstrated that young adults with apical periodontitis exhibit certain biochemical changes, such as elevated levels of C-reactive protein and an increased whole blood chemiluminescence, which have been shown to elevate the risk for cardiovascular diseases. Future research will be required to determine whether and to what extent may endodontic diseases affect general health. [source] Periapical lesion progression and cytokine expression in an LPS hyporesponsive modelINTERNATIONAL ENDODONTIC JOURNAL, Issue 7 2001A. F. Fouad Abstract Aim The purpose of this study was to compare periapical lesion progression and the expression of the bone modulating cytokines IL-1,, TNF-,, IL-4, IL-6 and IL-11 in periapical lesions of normal and C3H/HeJ (LPS hyporesponsive) mice. Methodology Pulps of both mandibular first molars from C3H/HeJ and BALB/c (normal) mice were exposed and inoculated with normal mouse oral microorganisms for 2, 4, 6, and 8 weeks. After euthanasia, specimens were prepared for histological examination. A quantitative evaluation of the lesional area and immunohistochemical stain counts was performed. Results There were no statistically significant differences in progression of periapical lesions for both mouse strains with time (two-factor anova, P > 0.05). The immunohistochemical staining revealed no overall differences between the two strains in levels of expression of the cytokines (P > 0.05). IL-11 expression did not change from control levels in BALB/c mice, but correlated with the expression of IL-6 and IL-4 in C3H/HeJ mice. Conclusion Responsiveness to LPS may not be significant in the pathogenesis of periapical lesions and in cytokine expression within the lesions, when the lesions are induced by non-specific oral flora. [source] Salivary IgA subclasses and bacteria-reactive IgA in patients with aggressive periodontitisJOURNAL OF PERIODONTAL RESEARCH, Issue 5 2002S. Hägewald The local salivary immunoglobulin A (IgA) response in patients with aggressive periodontitis to oral microorganisms and its role for the pathogenesis has not been determined. This study investigated the hypothesis that aggressive periodontitis patients have impaired oral secretory immunity. Our test group was made-up of 19 aggressive periodontitis patients and 19 age- and gender-matched periodontally healthy controls. Total IgA, IgA subclass 1, IgA subclass 2 and IgA reactive to Actinobacillus actinomycetemcomitans Y4, Treponema denticola ATCC 35404 and Candida albicans DSM 3454 were determined by enzyme-linked immunosorbent assay in whole unstimulated and stimulated saliva. A statistically significantly lower concentration and secretion rate of total salivary IgA (P < 0.01) and IgA1 (P < 0.001) was found in the aggressive periodontitis group in resting and stimulated saliva. A decrease of IgA2 (P < 0.05) was seen in resting saliva. Although only minor differences were detected in the concentration and secretion of bacteria-reactive IgA in both groups, the proportion of bacteria-reactive IgA from the total IgA was significantly higher (P < 0.01) in the aggressive periodontitis group in all three microorganisms tested. Our results indicate an inhibition of total secretory IgA. In particular an IgA subclass 1-specific decrease in aggressive periodontitis was noted, while the bacteria-reactive humoral immune system in saliva was activated. The role of the decrease of IgA1 immunoglobulins in aggressive periodontitis with respect to susceptibility for periodontal diseases has to be elucidated. [source] Stress and the periodontal diseases: growth responses of periodontal bacteria to Escherichia coli stress-associated autoinducer and exogenous FeMOLECULAR ORAL MICROBIOLOGY, Issue 3 2005A. Roberts Psychological stress is known to increase the circulating levels of the catecholamine hormones noradrenaline and adrenaline, which have been shown to influence the growth of a large number of bacterial species by acting in a siderophore-like manner or by inducing the production of novel autoinducers of growth. As we have previously demonstrated that periodontal organisms display differing growth responses to noradrenaline and adrenaline, the aim of this study was to determine whether these growth effects were based upon either siderophore-like or autoinducer mechanisms. Initial inocula of 43 microbial organisms normally found within the subgingival biofilm were established under anaerobic conditions (35°C). Each strain was re-inoculated into a serum-based minimal medium and growth was assessed by optical density (OD600nm) with test and control cultures performed in triplicate. Test cultures were supplemented with either 50 ,m ferric nitrate or a previously described Escherichia coli autoinducer of growth. Significant growth effects for supplementation with ferric nitrate (13 species responding positively) and E. coli autoinducer (24 species responding positively) were observed, with differences in growth response within bacterial species and within microbial complexes. When data for all organisms were compared with published responses to catecholamines there were only weak correlations with Fe (r = 0.28) and E. coli autoinducer (r = 0.34) responses. However, large positive responses (> 25% increase) to free Fe and/or E. coli autoinducer were significantly more prevalent in the group of organisms (n = 12) known to exhibit similar responses to catecholamine hormones (P < 0.01; ,2 = 4.56). The results support the view that catecholamines may exert their effects on subgingival organisms by initiating autoinducer production, or simply by acting in a siderophore-like manner, scavenging bound iron from the local environment. It is possible that autoinducer mechanisms may play an important role in the response of oral microorganisms to stress hormones, thereby contributing to the clinical course of stress-associated periodontal diseases. [source] Effects of a herbal gel containing carvacrol and chalcones on alveolar bone resorption in rats on experimental periodontitisPHYTOTHERAPY RESEARCH, Issue 4 2008Marco Antonio Botelho Abstract Carvacrol and dimeric chalcones are the respective bioactive components of Lippia sidoides and Myracrodruon urundeuva, popular medicinal plants of Northeastern Brazil with proven antimicrobial and antiinflammatory properties. Periodontal disease is associated with inflammation and microbiological proliferation, thus the study aimed to investigate the effect of a topical gel based on carvacrol and chalcones in the experimental periodontal disease (EPD) in rats. Animals were treated with carvacrol and/or chalcones gel, immediately after EPD induction, three times a day for 11 days. Appropriate controls were included in the study. Animals were weighed daily. They were killed on day 11, the mandibles dissected and alveolar bone loss was measured. The periodontium were examined at histopathology and the neutrophil influx into the gingiva was assayed using myeloperoxidase activity. The bacterial flora were assessed through culture of the gingival tissue. Alveolar bone loss was significantly (p < 0.05) inhibited by combined carvacrol and chalcones gel, compared with the vehicle and non-treated groups. The treatment with the combined gel reduced tissue lesion at histopathology, decreased myeloperoxidase activity in gingival tissue and inhibited the growth of oral microorganisms as well as the weight loss. Carvacrol and chalcones combination gel has a beneficial effect upon EPD in this model. Copyright © 2008 John Wiley & Sons, Ltd. [source] | ||||||||||