Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UMLS:C0031099 (periodontitis)
 12,489 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Actinobacillus actinomycetemcomitans has an important aetiological role in localized juvenile periodontitis and in progressive periodontitis in adults. A. actinomycetemcomitans is found mainly in periodontal pockets but also in whole saliva, a potential transmission medium. It is sensitive to peroxidase-halide systems, but the differences between periodontitis associated clinical isolates and type strains are unclear. The sensitivities of these 2 strain groups to lactoperoxidase (LP)-iodide (I(-))-hydrogen peroxide (H(2)O(2)) combinations were investigated, and the sensitivities were compared with the susceptibilities to four antibiotics. There was great variation between the sensitivities of different strains, but the 2 strain groups responded similarly. The LP (75 microg)-I(-) (100 nmol)-H(2)O(2) (1000 nmol) combination produced a similar degree of inhibition as 2 microg ampicillin. The LP-I(-) system might be a potential antimicrobial agent against A. actinomycetemcomitans transmission via saliva.
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PMID:Susceptibilities of different Actinobacillus actinomycetemcomitans strains to lactoperoxidase-iodide-hydrogen peroxide combination and different antibiotics. 1272 76

Porphyromonas gingivalis, an obligately anaerobic bacterium, is implicated as a major pathogen in the development and progression of chronic periodontitis. Although expression of several virulence factors of the bacterium has been found to be affected by environmental stress such as entrance into the stationary growth phase and heat, there is relatively little information on the mechanisms that may operate in the bacterium in response to environmental stress. In this study, a novel protein (UstA) was investigated that was initially identified following two-dimensional gel analysis. Expression of UstA was upregulated in stationary phase or by exposure to atmospheric oxygen. N-terminal sequencing and database analysis with the P. gingivalis genome sequence revealed that the UstA-encoding gene (ustA) was located upstream of a homologue of the usp gene encoding the universal stress protein on the chromosome. The ustA gene appeared to be transcribed in a monocistronic fashion, as revealed by primer extension and Northern blot analysis. To elucidate the role of UstA in the bacterium, chromosomal mutants carrying a disruption of the ustA gene were constructed. The ustA mutant grew slower than the wild-type parent strain in rich medium, resulting in a lower yield in stationary phase. Furthermore, in this mutant, expression levels of the P. gingivalis homologues of superoxide dismutase, thiol peroxidase and thioredoxin were markedly higher than those in the wild-type, especially in stationary phase. The ustA mutant was more resistant to diamide, a thiol-specific oxidant, than the wild-type. In addition, the ustA mutation suppressed hypersensitivities of the oxyR mutant to diamide, metronidazole and mitomycin C. These results suggest that UstA may play a significant role in oxidative stress responses in the bacterium.
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PMID:Novel stationary-phase-upregulated protein of Porphyromonas gingivalis influences production of superoxide dismutase, thiol peroxidase and thioredoxin. 1575 30

Some Gram-negative anaerobic bacteria have been associated with the infection of tooth supporting tissues, i.e. periodontitis. Of these bacteria, Fusobacterium nucleatum is sensitive to lactoperoxidase/myeloperoxidase-iodide-hydrogen peroxide system in vitro, but salivary concentrations of thiocyanate abolishes the bactericidality. These bacteria are located in periodontal pockets, on oral mucosa and in saliva. Although F. nucleatum most probably does not belong to the group of main periodontal pathogens, it sustains its proportion in the periodontal flora when gingivitis progresses to periodontitis. In this study, the sensitivity of F. nucleatum to different horseradish peroxidase-iodide-hydrogen peroxide combinations was tested both in buffer and in sterilized human whole saliva. Horseradish peroxidase was chosen because it does not bind thiocyanate at pH > or = 6. After 1h incubation at 37 degrees C, the cell viability was estimated by plate count and with flow cytometer using LIVE/DEAD BacLight kit (Molecular Probes, USA). In saliva, the horseradish peroxidase (50 microg/mL)-iodide (2.5 mM)-hydrogen peroxide (2.5 mM) combination decreased the amount of viable bacteria to 37% compared to 85% in the control without any of the components when measured with flow cytometer. Replacement of buffer by saliva decreased the bactericidality of the peroxidase system. However, in buffer less iodide and hydrogen peroxide was needed to produce significant decrease in the number of viable bacteria when measured by plate count than with flow cytometer. Our study shows that horseradish peroxidase-iodide-hydrogen peroxide combination is able to kill F. nucleatum cells in saliva. Horseradish peroxidase-iodide-hydrogen peroxide combination may be useful to diminish the degree of re-colonization of periodontitis-associated bacteria after periodontal therapy and to inhibit the transmission of these bacteria via saliva.
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PMID:Susceptibility of Fusobacterium nucleatum to killing by peroxidase-iodide-hydrogen peroxide combination in buffer solution and in human whole saliva. 1688 84

Aggregatibacter actinomycetemcomitans is an oral pathogen causing localized aggressive periodontitis (LAP). Recently, we characterized for the first time a quinol peroxidase (QPO) that catalyzes peroxidase activity using quinol in the respiratory chain of A. actinomycetemcomitans for the reduction of hydrogen peroxide. In the present study, we characterized the phenotype of a QPO null mutant. The QPO null mutant shows an oxidative stress phenotype, suggesting that QPO plays a certain role in scavenging endogenously generated reactive oxygen species. Notably, we discovered that the QPO null mutant exhibits a production defect of leukotoxin (LtxA), which is a secreted bacterial toxin and is known to target human leukocytes and erythrocytes. This result suggests that QPO would be considered as a potential drug target to inhibit the expression of LtxA from A. actinomycetemcomitans for the treatment and prevention of LAP.
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PMID:Characterization of a quinol peroxidase mutant in Aggregatibacter actinomycetemcomitans. 1861 92

Periodontitis is a chronic inflammatory disease characterized by tissue destruction which is usually diagnosed through clinical and radiographic signs. The detection of changes in the chemical composition of saliva could be used to reflect gingivo-periodontal alterations. The aim of this study was to identify salivary parameters that could identify different stages of the periodontal disease. The study group included 118 adults, 89 of them with mild, moderate or severe chronic periodontitis. The remaining participants comprised the control group. Total saliva was analyzed for physical and chemical properties. Dodecyl sulphate polyacrylamide gel electrophoresis (SDS-PAGE) was used for protein detection and zymography for type IV collagenase identification. Salivary flow rate, pH and buffer capacity showed similar values in all groups. Proteins were augmented in severe periodontitis, as also shown by SDS-PAGE. Hydroxyproline rose significantly in all periodontal groups as secretory Immunoglobulin A significantly diminished compared with the control group. An increase in peroxidase was detected in moderate and severe periodontitis. All salivary samples contained 200-116-92 kDa gelatinases; minor bands at 66-31 kDa were also present in all periodontitis groups. Calcium levels showed significant differences between all periodontitis groups compared with the control group. Quantitative changes in the chemical composition of the saliva of patients with periodontal disease could be of significance in the diagnosis and progression of periodontal disease.
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PMID:Changes in saliva protein composition in patients with periodontal disease. 1983 86

Inflammatory reaction is always accompanied by increased intensity of free-radical oxidation, especially when the phenomena of hypoxia and microcirculatory disorders that occur during the development of side-effects of acrylic removable dentures. This study determined the effectiveness of adaptogens, antioxidants in the complex treatment of diseases of tissues prosthetic field and their influence on the processes of LPO in whole mixed unstimulated saliva. Formed in the reaction to initiate the process of oxygen radicals (OH, RO, O(2)), initiate the formation of lipid peroxide radicals RO(2) biological substrate, the recombination of which leads to the emergence of unsustainable tetroxids, which decays with the release of light quanta. This luminescence is recorded as an amplified current of the photomultiplier, the registration systems. The results suggest the intensive formation of free radicals and peroxides in diseased tissue prosthetic field. Probably the main reason for increasing free-radical oxidation is the release of peroxidase from the crumbling inflammation, phagocytes (mainly neutrophils). The process of peroxidation contributes to an increase in blood supply to inflamed tissues, leading to local enrichment of oxygen, as well as toxic effects of acrylic bases of partial and complete removable dentures in the prosthetic field of tissue. Effect of antioxidants in combination with traditional treatment in 70 patients with periodontal disease and prosthetic bed was assessed by chemiluminescence analysis of whole mixed unstimulated saliva. The level of lipid peroxidation and chemiluminescence activity exceeded the normal values in the 1,5-2 - twice before the treatment. After treatment with antioxidants, these parameters decreased and increased during remission. Thus, studies to determine the status of saliva chemiluminescence method to treat and monitor the dynamics after treatment of periodontitis tissues supporting teeth prosthetic field in the control group and the main observation, revealed the following pattern: the approach of all the indices to normal in patients with a core group, which corresponded to the clinical dynamic index parameters of periodontal tissues supporting teeth prosthetic field, and a similar core group of the positive dynamics of the intensity values of chemiluminescence-indicators in the control group up to 3 months of observation, with a significant deterioration of the same indicators at a later time dynamic monitoring.
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PMID:[Chemiluminescence of whole saliva in antioxidant treatment of prosthetic bed tissues]. 2041 12

Periodontitis is commonly observed in dogs. In human medicine, it is well documented that matrix metalloproteinases (MMPs) are involved in the destruction of the periodontium. Therefore, the aim of this prospective study was to investigate the impact of MMPs and their inhibitors, the TIMPs (tissue inhibitors of metalloproteinases), on canine periodontitis. The oral cavities of 57 dogs were examined clinically and radiologically. Gingival biopsies were obtained from the examined dogs and histologically analysed via haematoxylin and eosin stained sections. Immunohistological detection of MMP-2, MMP-3, MMP-8 and MMP-9 as well as TIMP-1 and TIMP-2 was performed by the avidin-biotin peroxidase complex technique. All sections were evaluated by light microscopy. Statistically significant positive correlations were detected between the histologically verified degree of inflammation and the expression of MMP-2, MMP-3, MMP-8 and MMP-9 as well as between changes in collagen fibre content and the occurrence of MMP-2, MMP-8 and MMP-9. Concerning TIMP-1 and TIMP-2, non-significant, generally negative correlations were observed. In summary, in canine periodontitis, an increased expression of the above mentioned MMPs and a tendentially decreased expression of TIMPs are present. In conclusion, in canine periodontitis, a MMP-TIMP imbalance is suggestive of contributing to the destruction of the periodontium.
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PMID:Immunohistochemical localisation and effect of matrix metalloproteinases and their inhibitors on canine spontaneous periodontitis. 2626 63

Aggregatibacter actinomycetemcomitans is an oral pathogen for aggressive periodontitis, and encodes a triheme c-containing membrane-bound enzyme, quinol peroxidase (QPO) that catalyzes peroxidase activity using quinol in the respiratory chain. In the previous work, we have characterized recombinant QPO purified from the membrane fraction of Escherichia coli harboring a plasmid containing QPO gene. Irreversible inactivation of QPO by high concentration of H2O2 exhibited pseudo-first order kinetics. Analysis of initial-rate kinetics of QPO may suggest that enzyme catalytic mechanism is explained by a Ping Pong Bi Bi system rather than sequential systems. In addition, the redox reactions of cytochrome c in the presence of several values of [Q1H2]/[Q1] were at equilibrium, and only about 2/3 of the cytochrome c of QPO is reduced at high ratios of [Q1H2]/[Q1]. These results indicated that one of the three heme c moieties of QPO is maintained in an oxidized form even at increased ratios of [Q1H2]/[Q1], suggesting that QPO is reduced in the absence of H2O2 and only two of the three heme c moieties are reduced in the presence of high concentration of the Q1H2. Product inhibition of QPO accorded with our theoretical model for the reaction mechanism. Considered together, the enzymatic kinetics data for QPO confirm the Ping Pong Bi Bi system.
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PMID:Enzymatic kinetics of the quinol peroxidase of an aggressive periodontopathic bacterium. 2808 20


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