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

Polymorphonuclear leukocytes (PMNs) have been implicated in the pathogenesis of inflammatory gingivitis and periodontitis. To further study the role of PMNs in mediating gingival injury, we cocultured these cells in vitro with monolayers of human gingival epithelial cells. Scanning electron microscopy revealed that the epithelial cells were homogeneous and SDS-PAGE/immunoblot analysis identified the presence of keratins K3, K13 and the K6/16 pair which authenticated the oral origin of the cells. Injury to the gingival cells was determined by scanning electron microscopy and measurement of cell detachment and cytolysis. Unstimulated PMNs produced minimal lysis or detachment, but PMNs stimulated by phorbol myristate acetate produced marked epithelial cell detachment without lysis, which was time- and PMN-dose-dependent. Supernatants of activated PMNs were similarly effective, indicating that the mediator was a stable soluble substance. Elastase and cathepsin G, two neutral proteases of PMN origin, produced time- and concentration-dependent detachment of gingival epithelial cells, suggesting that these enzymes may mediate this form of injury. In other studies, gingival epithelial cells were exposed to PMN myeloperoxidase (MPO), chloride and glucose plus glucose oxidase (GO) as a hydrogen peroxide (H2O2) generating system. The toxic oxygen species produced by this system caused lysis of the epithelial targets which was dependent on the duration of incubation and the concentrations of MPO and GO. Azide, an inhibitor of MPO, and catalase, a scavenger of H2O2, inhibited the lytic activity of this system. Scanning electron micrographs of gingival epithelial cells cocultured with activated PMNs showed lifting of the cells from the plating surface, while target cells attacked by the MPO system revealed extensive damage of cell membranes. These studies indicate that activated PMNs cause nonlytic detachment injury to gingival epithelial cells which may be mediated by digestion of their extracellular matrix by granule neutral proteases. Furthermore, PMN MPO is capable of generating toxic oxygen species which can lyse these epithelial cells. Collectively, these actions could have profound adverse effects on the function and integrity of the gingival epithelium.
 ...
PMID:Neutrophil-mediated damage to human gingival epithelial cells. 131 Oct 41

Collagenases are known to be associated with tissue destruction in chronic inflammatory diseases such as periodontal diseases and rheumatoid arthritis. Collagenases are secreted by circulating inflammatory cells (polymorphonuclear leukocytes and monocytes), resident mesenchymal cells and epithelial cells in latent forms, which can be activated by proteases and compounds reacting with protein thiol groups. We have studied here the effects of oxygen-derived free radicals (ODFR) on latent human neutrophil collagenase. Also, in order to elucidate the cellular sources of collagenases, the ability of human gingival crevicular fluid (GCF) collagenases both from adult periodontitis (AP) and localized juvenile periodontitis (LJP) patients to degrade soluble interstitial collagen types I and II was studied. ODFR generated by the xanthine oxidase/hypoxanthine system in the presence of trace amounts of iron and EDTA activated latent neutrophil collagenase to an equal extent as the known activators phenylmercuric chloride and gold thioglucose. ODFR activation was inhibited by desferoxamine and mannitol as well as by superoxide dismutase and catalase. Clear differences in the susceptibility of collagen types I and II to AP and LJP GCF collagenases were observed. AP GCF collagenase degraded type I and II collagens at equal rates, resembling the substrate-specificity of human neutrophil collagenase. LJP GCF collagenase degraded type I collagen considerably faster than type II collagen, which was only negligibly degraded. This corresponds to the substrate specificity of fibroblast collagenase. Zymographic evaluation of gelatinolytic proteases showed the presence of 90 and 68 kD gelatinases in both AP and LJP GCF. Non-proteolytic means apparently provide a potent activation pathway of neutrophil collagenase in vivo and the hydroxyl radical was identified to be one of the potent activating oxidants.(ABSTRACT TRUNCATED AT 250 WORDS)
 ...
PMID:Non-proteolytic activation of latent human neutrophil collagenase and its role in matrix destruction in periodontal diseases. 256 61

Actinobacillus (Haemophilus) actinomycetemcomitans is a facultatively anaerobic, gram-negative coccobacillus which is a possible etiological agent in juvenile periodontitis (JP). In this study, bacterial flora, especially the occurrence of A. actinomycetemcomitans, in the periodontal pockets of one juvenile with gingivitis (G), one JP patients, five rapidly progressive periodontitis (RP) patients and one adult periodontitis(AP) patient, and one adult with healthy periodontium was investigated using a blood agar medium and a selective medium for A. actinomycetemcomitans. Eight hundred and sixty-five bacteria were isolated from the periodontal pockets, examined for their gram-stain, cell morphologies, relations to O2 and CO2 and catalase reaction, and divided into 21 groups on the basis of these characters. Among the isolates, 604 isolates were further characterized biochemically and identified. A. actinomycetemcomitans was found as 0.2% of the flora of a site in the JP patient, as 9% of the flora of a site in the G patient, and as 19% and 1%, respectively, of the flora of a site in the two RP patients. However, the organism was not detected in another lesion site of the JP patient. In our JP and RP patients, Fusobacterium, Wolinella, Streptococcus, and obligately anaerobic, gram-positive cocci were frequently found at high levels. The bacterial flora of the G and AP patients were more heterogeneous and included Bacteroides at relatively high proportions. These results indicate that A. actinomycetemcomitans is not always associated with JP but occurred in some patients with RP and G.
 ...
PMID:Actinobacillus (Haemophilus) actinomycetemcomitans in periodontal disease. 377 88

Spirochetes have been implicated in the pathogenesis of several human infections including syphilis, yaws, Lyme disease, and periodontal diseases. We examined soluble sonic extracts of oral spirochetes (Treponema denticola and T. vincentii) for their ability to alter human lymphocyte function. These organisms were isolated from subgingival plaque of patients with periodontitis. We found that sonicates of several but not all strains of T. denticola caused a dose-dependent inhibition of human lymphocyte responsiveness to Con A, PHA, PWM, and the recall antigen SKSD. Suppression involved alterations in DNA, RNA, and protein synthesis; there was no effect on cell viability. In contrast, sonicates of T. vincentii (medium-sized spirochetes) had no demonstrable effects on lymphocyte activation. The suppressive factor derived from T. denticola is heat-labile with a m.w. of approximately 100,000. To achieve maximal suppression, sonicates had to be added during the first 24 hr of incubation; there was no inhibition observed when added at 48 or 72 hr (along with 3H-TdR). Suppression was dependent on the presence of adherent monocytes; removal of these cells prevented spirochete-induced suppression of lymphocyte proliferation. Furthermore, the combination of indomethacin and catalase were able to reverse (or prevent) the inhibitory effects of the spirochete extracts, demonstrating a requirement for both prostaglandins and hydrogen peroxide. The potential role of such suppressive factors in periodontal disease is discussed.
 ...
PMID:Suppression of human lymphocyte responses by oral spirochetes: a monocyte-dependent phenomenon. 669 6

Gram-negative, non-saccharolytic, brown- or black-pigment-forming, nonmotile anaerboic coccobacilli, capable of decomposing hydrogen peroxide and identified as Bacteroides asaccharolyticus (B. melaninogenicus subsp. asaccharolyticus), were isolated from the supra- and subgingival plaques of beagle dogs with gingivitis or periodontitis. The organisms remained viable for many hours in an aerobic atmosphere as evidenced by their ability to grow subsequently in an anaerobic environment. They also grew well on agar media that were not reduced before use. Although blood was required for pigmentation of colonies, organisms grew on media that lacked hemin, menadione, blood, or reducing compounds. Increased oxygen tolerance, catalase activity, and different nutritional requirements differentiate these organisms from strains of B. asaccharolyticus isolated from humans.
 ...
PMID:Characteristics of Bacteroides asaccharolyticus from dental plaques of beagle dogs. 738 Oct 20

The cells of a human oral spirochete, Treponema denticola ATCC 35405, and of seven clinical isolates of this organism obtained from the subgingival dental plaque of periodontitis patients were studied for their ability to grow in an aerobic and an anaerobic environment, and for their profile of peptidohydrolase and oxidoreductase enzymes. The growth yield of aerobically grown cultures was either comparable to or higher than that of anaerobically grown ones regardless of whether prereduced broth, freshly prepared broth or oxidized broth was used. However, elimination of certain supplements from the growth media resulted in poor growth regardless of the nature of the gaseous environment. The microscopic morphology and motility of the cells were not affected by differences in the gaseous atmosphere. Quantitative studies on several peptidohydrolase activities suggest that anaerobically grown cells displayed higher specific activity especially toward N alpha-L-prolyl-2-naphthylamine, indicating that increased synthesis of proline iminopeptidase enzymes (or enzyme) of the cells was associated with anaerobic growth conditions. The formation of enzymes hydrolysing N alpha-benzoyl-DL-arginyl-2-naphthylamine (and the corresponding p-nitroaniline) was not affected to the same extent. Growth experiments suggest that T. denticola ATCC 35405 is a facultatively anaerobic spirochete instead of an obligate anaerobe as reported in previous literature. The quantitative enzyme studies suggest that the gaseous growth atmosphere of the cells can exert a selective effect on the activity levels of certain peptidolytic enzymes of this organism. Such effects were not observed when the whole cells were studied by means of qualitative or semi-quantitative enzyme tests. The activities of catalase, peroxidase and superoxide dismutase of the cells were low and variable. Because of this, it was not possible to relate these oxidoreductase activities to the composition of the gaseous atmosphere.
 ...
PMID:Proteolytic and oxidoreductase activity of Treponema denticola ATCC 35405 grown in an aerobic and anaerobic gaseous environment. 824 25

The inability to examine initiation and progression of periodontal disease and to assess certain therapies in humans has led to a great interest in the use of animal models in periodontal research. Some of the most prominent animals used are non-human primates. This article reviews the characteristics of non-human primate models in periodontal health, in the transition from health to gingivitis to periodontitis, and in experimental gingivitis and periodontitis. Where possible, the results of these studies are compared with results from human studies. Only a few studies have compared in detail the anatomy, physiology, immunology, and tissue interactions in monkeys with those of humans. With the exceptions of differences and variations in size of the dentition, the number of each tooth type as well as larger canines, presence of diastemata between anterior teeth, and an edge-to-edge relationship of the incisors, the dental and periodontal anatomy of non-human primates seem quite similar to that of humans. Clinically healthy gingiva can be established and maintained in non-human primates, and gingivitis as well as periodontitis occur in these animals. It is possible to induce experimental periodontitis by placement of peri-dental silk ligatures or orthodontic elastics as well as by surgical removal of alveolar bone. Although the most appropriate model for studies of periodontal disease pathogenesis in non-human primates appears to involve the application of silk ligatures, some difficulties may occur in establishing periodontal break-down by using this model. Many clinical, histological, microbiological, and immunological characteristics of spontaneous and experimental marginal inflammation in most non-human primates are similar to those in humans. The most significant differences between small non-human primates and humans are the very limited number of lymphocytes and plasma cells in the inflammatory infiltrate of squirrel monkeys (Saimiri sciureus) and marmosets. Therefore, the use of squirrel monkeys and marmosets may not be appropriate in many studies of periodontal disease pathogenesis. The most significant microbial differences between macaque species and humans are a lower proportion of Actinomyces species, the presence of a catalase-producing Prevotella melaninogenica strain, and the high carrier rate for Actinobacillus actinomycetemcomitans in subgingival plaque of macaque species. The significance of these differences is presently unknown. It is concluded that the use of many non-human primate species due to the apparent close anatomic and biologic similarities to humans is appropriate in experimental studies of periodontal disease, provided the use of laboratory animals is requisite and lower species are not applicable.(ABSTRACT TRUNCATED AT 400 WORDS)
 ...
PMID:Non-human primates used in studies of periodontal disease pathogenesis: a review of the literature. 833 50

One hundred isolates of the oral pathogenic bacterium Porphyromonas gingivalis were genetically characterized by determining the electrophoretic mobilities of 16 metabolic enzymes and the presence or absence of catalase activity. A total of 78 distinct electrophoretic types (ETs), representing multilocus genotypes, were identified, and cluster analysis placed them in three major phylogenetic divisions. Division I (71 ETs) included all 88 human isolates examined, most of which had been recovered from patients with periodontitis, together with 4 monkey isolates. The strains in division II (four ETs) and division III (three ETs) are strongly differentiated from those in division I and apparently represent two previously unclassified (cryptic) species. The mean genetic diversity per enzyme locus among the 92 isolates of division I (P. gingivalis, strict sense) was 0.321, and the strains were distributed among 14 phylogenetic clusters and single-ET lineages. The population structure is basically clonal, with some clonal genotypes being widespread, and even global, in distribution. There was no evidence of association between specific genetic lineages or clusters of ETs and the type of disease (periodontitis or root canal infections), invasive potential, serogroup, or fimbrial restriction fragment length polymorphism group. The finding that dental patients are infected by strains of a wide variety of chromosomal genotypes suggests that interstrain variation in pathogenicity is small. On the basis of the observed genetic structure of natural populations of P. gingivalis, we hypothesize that the role of this microorganism in the pathogenesis of periodontitis and other dental infections is largely opportunistic.
 ...
PMID:Genetic structure of populations of Porphyromonas gingivalis associated with periodontitis and other oral infections. 838 Feb 81

A total of 259 Gram-negative Porphyromonas-like rods isolated from subgingival plaque samples of 16 family-owned dogs with naturally occurring periodontitis were characterized phenotypically by biochemical reactions, metabolic end products and enzymatic activities (API-ZYMTM, RoscoTM). Four distinct groups were found. Group A isolates (63) were asaccharolytic, lipase negative, trypsin positive and produced phenylacetic acid (PAA) from peptone-yeast extract glucose broth. Unlike P. gingivalis strains they were catalase positive. Group B isolates (42) differed from those of group A by a positive lipase reaction and from those of group D by failing to ferment sugars. Group C isolates (88) were asaccharolytic and did not produce PAA. They were alpha-fucosidase, N-acetyl-beta-glucosaminidase (beta-NAG) and trypsin negative, resembling P. endodontalis, but unlike human isolates, they were catalase positive. Subgroup C.1 isolates (6) differed from those of parent group C by producing minor amounts of PAA, and subgroup C.2 isolates (12) were beta-NAG positive. Group D isolates (46) were weakly fermentative, lipase, catalase and trypsin positive, and produced PAA. They resembled the B (P.) salivosus type strain which, in our hands, fermented weakly glucose, lactose and mannose. Two isolates could not be assigned to any of the previous groups.
 ...
PMID:Porphyromonas-like gram-negative rods in naturally occurring periodontitis in dogs. 851 57

Clinical study of the efficacy of oliphen treatment in generalized periodontitis in comparison with galascorbin treatment was conducted. Oliphen arrested the inflammatory process in the periodontium quickly and effectively and shortened the duration of treatment by half. Under its effect lipid peroxidation became less intense, the level of malonic dealdehyde decreased, and the activity of catalase in the oral fluid of patients with periodontitis increased. The favorable effect of oliphen in periodontitis is connected with its antioxidant and antihypoxant properties.
 ...
PMID:[A clinico-pharmacological study of olifen in periodontal inflammation]. 920 79


1 2 3 4 Next >>