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)

A comparative study of prevalence of periodontal diseases in an indigenous Armenian population and a population of refugees in Armenia has been performed. The refugees population was considered a population of subjects under permanent stress conditions. It has been shown that in the refugees population there are higher prevalence of periodontal diseases, first of all periodontitis, and more marked heaviness of injures in periodontal tissues that those in the indigenous population. These changes were accompanied with elevated signs of disturbances of hemo-endothelial balance. In particular, there were profound alterations of normal ratio of 6-keto-PGF1a/NXB2 and increased level of markers for endothelial disorganization, thrombomodulin and von Willebrand factor, in the blood. It is that stress-induced disturbances of the hemo-endothelial balance among the refugees may contribute to developing periodontal diseases in this population.
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PMID:[The clinico-biochemical characteristics of periodontal diseases in subjects who are under conditions of constant, permanent stress]. 865 70

In order to determine the effect of bacterial proteinases on activation of the protein C system, a negative regulator of blood coagulation, two arginine-specific cysteine proteinases (gingipains R) from Porphyromonas gingivalis, a causative bacterium of adult periodontitis, were examined. Each enzyme activated human protein C in a dose- and incubation time-dependent manner. Interestingly, the form of enzyme being composed of a non-covalent complex containing both catalytic and adhesion domains (RgpA) produced activated protein C 14-fold more efficiently than RgpB which contained the catalytic domain alone. The kcat/Km value of RgpA was 18-fold higher than that of RgpB and comparable to that of the thrombin-thrombomodulin complex, the physiological activator of protein C. RgpA catalyzed protein C activation was augmented 1.4-fold by phospholipids, ubiquitous cell membrane components. Furthermore, RgpA, but not RgpB, could activate protein C in plasma and this resulted in a decrease of the protein C concentration in plasma, which is often observed in patients with sepsis during the development of disseminated intravascular coagulation (DIC). These data indicate that RgpA is a more potent activator of protein C than RgpB and suggest that only the former enzyme can cause protein C activation in vivo. The present study further suggests that bacterial proteinases may possibly contribute to the consumption of plasma protein C which predisposes to DIC and/or promotes a thrombotic tendency towards DIC in sepsis.
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PMID:Activation of protein C by arginine-specific cysteine proteinases (gingipains-R) from Porphyromonas gingivalis. 1006 39

Epidermal keratinocytes thrombomodulin (TM) has been shown to regulate thrombin at sites of cutaneous injury in addition to a role for epidermal differentiation. TM, a major anticoagulant proteoglycan of the endothelial cell membrane, is a thrombin receptor that acts as a co-factor for protein C activation. Thrombin has pro-inflammatory effects for periodontitis. However, little is known about TM in gingival tissue with periodontitis. We used immunohistochemistry to examine expression of TM in gingival epithelium from patients with periodontitis. In vitro, we observed TM expression at varying Ca2+ concentrations by confocal laser scanning microscopy, examined the expression of TM mRNA and tested TM co-factor activity. Furthermore, we measured TM concentration in gingival crevicular fluid (GCF) from 11 severe adult cases of periodontitis using enzyme-linked immunosorbent assay. Immunoreactive TM was present in gingival epithelium and junctional epithelium, and was reduced in inflamed gingival epithelium compared to healthy gingival epithelium. Ultrastructurally, TM, including microvilli, was observed on the cell membrane. TM localization in cells cultured in 0.09 mM Ca2+ differed from that in cells exposed to 1.2 mM Ca2+. Northern analysis demonstrated TM mRNA in gingival keratinocytes more than in human umbilical vein endothelial cells (HUVEC). Gingival keratinocytes also facilitated protein C activation by thrombin, although less strongly than HUVEC. TM in GCF at sites with bleeding on probing in patients was significantly elevated (p < 0.001, Student's t-test). TM in gingival epithelium may regulate thrombin activity at sites of coagulation and inflammation with periodontal disease, although inflammation may impair this regulation of thrombin.
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PMID:Expression and activity of thrombomodulin in human gingival epithelium: in vivo and in vitro studies. 1092 69