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Objective: To study non-osteoclastic sources of cathepsin K in periodontitis., Materials and Methods: Tissue samples were obtained from 10 otherwise healthy periodontitis pati-ents during routine periodontal flap operations and 10 systemically and periodontally healthy individuals who underwent extraction operations for retained third molars. Methods used were immunohistochemistry, image analysis, immunofluorescence double-staining, gingival fibroblast culture, tumour necrosis factor-α (TNF-α) stimulation and Western blotting., Results: Macrophage-like cells, fibroblast-like cells, vascular endothelial cells and gingival epithelial cells were more intensively stained for cathepsin K and also more frequent in periodontitis than in controls (665 ± 104 vs 258 ± 40 cells mm(-2) , P < 0.01). Some cathepsin K(+) cells in periodontal tissues were CD68(+) , but some were CD68(-) and probably fibroblasts. Indeed, in gingival fibroblast culture, resting fibroblasts released cathepsin K, more 43 kD procathepsin K than 29 kD active cathepsin K. TNF-α increased the release of the activated cathepsin K 4- to 5-fold., Conclusions: Results suggest that GCF-cathepsin K is not only osteoclast-derived, but in periodontitis, also other cells contribute to it. GCF-cathepsin K, perhaps together with intracellular, lysosomal collagenolytically active cathepsin K in fibroblasts, macrophages and gingival epithelial cells, can contribute to the loss of attachment and destruction of the periodontal ligament., (© 2014 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.)

Objective: The aim of this study was to evaluate the presence and distribution of CD1a and S100 protein markers in states of gingival health and chronic periodontitis in human subjects., Materials and Methods: Gingival tissue samples were derived from 10 healthy and 10 chronic periodontitis-affected human subjects. The presence and distribution of CD1a and S100 protein was assessed using immunohistochemistry, and the cell types involved in their expression was determined., Results: The presence and distribution of CD1a was confined only to the gingival epithelium, whereas S100 was seen in the epithelium and connective tissue. However, increased expression of both CD1a and S100 protein was seen in periodontitis-affected gingival tissues compared with healthy gingiva. Immunohistochemistry demonstrated that CD1a- and S100-positive cells in the epithelium are Langerhans cells (LCs) and S100 positive cells in the connective tissue are dendritic cells (DCs)., Conclusion: Our findings suggest the transition of CD1a-positive LCs to S100-positive DCs from epithelium to connective tissue in response to an antigenic challenge. Demonstration of increased number of S100-positive DCs in the gingival connective tissue in chronic periodontitis possibly suggests their involvement in bone resorption in addition to their antigen presentation property., (© 2012 John Wiley & Sons A/S.)

Background: This study investigated the phagocytic function of peripheral granulocytes and monocytes from adult individuals with Down syndrome (DS) and assessed the relation between phagocytic function and periodontal status., Methods: Fifty-five DS individuals (18-56 years old), 74 mentally retarded individuals, and 88 medically healthy controls (HC) participated in the study. Gingival inflammation index, plaque index, probing depth, periodontal attachment level (AL), and bleeding on probing were taken for each subject. Whole blood was collected for granulocyte/monocyte phagocytosis tests. Phagocytic function was determined by flow cytometry in terms of percentage of cells actively involved in phagocytosis, and phagocytic intensity (magnitude of the bacterial staining per cell)., Results: Phagocytic intensity of both granulocytes and monocytes was comparable in HC and DS subjects. While AL was directly related to phagocytic intensity of both granulocytes (r = 0.14, P = 0.03) and monocytes (r = 0.2, P = 0.003) in all subjects, this relationship was stronger in DS than in other subjects, even after controlling for known risk factors for periodontitis (P < 0.05). Monocyte phagocytic intensity was the only necessary predictor of AL (P = 0.003), indicating a similar relationship between AL and phagocytic activity in either cell type., Conclusions: While granulocyte and monocyte phagocytic intensities are similar in Down and non-DS individuals, phagocytic intensity was associated with more AL in DS than non-DS individuals., (© 2011 John Wiley & Sons A/S.)

Background/aim: In periodontitis, bacteria and pathogen-associated molecular patterns are sensed by Toll-like receptors (TLRs), which initiate intracellular signaling cascades that may lead to host inflammation. In this study, the expression and distribution of TLRs (TLR-1 to TLR-10) were immunohistochemically detected in gingival epithelium and connective tissue., Methods: Immunohistochemistry was used for the localization of TLRs in gingival tissue samples from 10 patients with chronic periodontitis and 10 healthy controls; these samples were obtained during routine periodontal flap operations and during extraction operations performed for retained wisdom teeth, respectively. For the evaluation, epithelial layers were stratified to basal, spinous, and superficial layers, and the percentages of TLR-positive cells were determined., Results: Both healthy and periodontitis gingival tissues expressed all TLRs except TLR-10. In patients with periodontitis, epithelial cells showed increased TLR expression towards the basal layer. Healthy controls showed more variable cellular TLR expression and distribution between the layers of epithelium. In the connective tissue, consistently higher TLR expression was found within the periodontitis group compared to the healthy group., Conclusions: For the first time, the cellular expression and distribution of TLR-1 to TLR-10 have been studied in periodontitis, indicating that TLR-1 to TLR-9 are differentially expressed both in connective tissue and epithelial layers. Except for TLR-7 and TLR-8, all the other TLRs showed statistically significant differences between patients with periodontitis and healthy controls, suggesting their involvement in the pathogenesis of periodontitis.

The expression of the inducible nitric oxide synthase enzyme (iNOS) is a response to an inflammatory stimulus and produces a large amount of nitric oxide (NO), which may act as a cytotoxic molecule against the invading microorganism and may be related to both harmful and beneficial effects to tissues., Objective and Material and Methods: In order to further characterize the presence of NO in human periodontal disease, we undertook a quantitative study of iNOS positive cells in samples of clinically healthy gingival tissues, plaque-induced gingivitis and localized chronic periodontitis using immunohistochemistry., Results: A significant increase in the number of iNOS+ cells mm-2 was found in the samples of the gingivitis and periodontitis compared with those of the control. In all groups most of the polymorphonuclear cells showed intense immunoreactivity for iNOS independent of the disease stage, and the percentage of iNOS+ polymorphonuclear cells increased significantly in periodontal disease when compared with the control., Conclusion: Our results indicate that iNOS increases in the presence of periodontal disease. In addition, our findings suggest that polymorphonuclear cells present an additional activation pathway in periodontal disease, expressing significant iNOS and probably representing an important source of NO in human periodontal disease that has not been previously reported.

Objective: Identify types, prevalence and severity of periodontal changes associated with HIV infection., Design: Cross-sectional controlled blinded study., Setting: Open access genito-urinary medicine clinic., Participants: Convenience sample of 794 homosexual men aged 18-65., Outcome Measures: Prevalence, extent and severity of probing attachment loss (PAL), pocketing, gingival ulceration, gingivitis, bleeding on probing (BOP), gingival red bands and diffuse and punctate erythema of the attached gingiva (selected a priori)., Results: Prevalences in men with (n = 312) and without HIV (n = 260) were: PAL (> or = 1 site > or = 4mm), 59.6% and 28.5% respectively (P < 0.001, chi 2); pocketing (> or = 1 site > or = 4mm) 51.0% and 31.9% (P < 0.001); BOP, 96.5% and 92.3% (P = 0.038); gingival ulceration, 3.2% and 1.0% (P = 0.031), red banding, 12.2% and 10.0% (P = 0.410); diffuse erythema, 12.5% and 3.1% (P < 0.001) and punctate erythema, 9.6% and 1.1% (P < 0.001). Decreased CD4 lymphocyte counts predicted the presence, extent and severity of PAL (P = 0.023, 0.027 and 0.060) but not pocketing. Oral candidiasis predicted the extent and severity of gingivitis and the presence of diffuse and punctate erythema. (P = 0.037, 0.011, 0.002 and < 0.001)., Conclusions: Destruction of periodontal attachment is associated with progression of HIV disease whereas pocketing is associated with HIV infection but not disease progression. Gingival ulceration is associated with HIV but gingivitis and erythema of the attached gingiva are most strongly associated with oral candidiasis. Gingival red bands were not associated with HIV infection.

Background: In biological studies of periodontitis, there has been long-standing confusion between the ubiquitous phenomena of inflammation and the essential criterion of attachment loss. This is partly attributable to inadequate methods of clinical measurement, but seems also to be a consequence of an unproven and usually unstated assumption that the same biological processes underlie both inflammation and attachment loss. Developments in unidimensional clinical probing methods have helped in studies of periodontal treatment. However, such methods are intrinsically unsuitable in studies of periodontal diseases, and may have given them a false sense of security. the confusion has been compounded by inappropriate use of statistical techniques in an attempt to solve problems which do not arise from mathematical models but are intrinsic to measurement methods., Objective: This paper is a clinician's attempt to state the current difficulties and suggest some ways forward, including the development of three-dimensional measurement, non-invasive probing, and several objectives for biochemical, microbiological and immunological research.

Unlabelled: Porphyromonas gingivalis demonstrates a strong association with adult periodontitis although some individuals with the infection do not experience attachment loss. Therefore differences in the immune response to this organism may be of importance to the outcome of the disease., Objective: The aim of this study was to determine whether P. gingivalis positive subjects with and without periodontal breakdown, reacted differently to P. gingivalis antigens as assessed by the pattern of serum antibody reactivity., Materials and Methods: Two highly defined groups of subjects were chosen for this study. Both demonstrated P. gingivalis in their plaque and both had responded to P. gingivalis as shown by the presence of serum antibodies. The two groups differed only in their apparent clinical susceptibility to periodontal breakdown. Western blots of P. gingivalis membrane antigens were probed with sera from the two groups to determine their reactivity to specific antigens., Results: Analysis of the immunoblots showed that there were no differences in either the total numbers of bands, or bands recognized by the majority of subjects in the gingivitis and adult periodontitis groups. There were however, four bands recognized by the majority of the gingivitis group and not by the majority of the adult periodontitis group, there being a significant difference (P = 0.03) in the recognition of the 91.4-kDa antigen band. A further five antigens of lower molecular weight were seen by the majority of the adult periodontitis group and not by the majority of the gingivitis group. When sera were tested against purified P. gingivalis LPS, the results indicated that the five antigens seen by the majority of the adult periodontitis group had molecular weights which were in the range exhibited by the LPS antigens., Conclusion: These results suggest that gingivitis and adult periodontitis subjects with P. gingivalis infection, may recognize different P. gingivalis antigens.