Activities of lysozyme and salivary peroxidase in unstimulated whole saliva in relation to plaque and gingivitis scores in healthy young males

The purpose of the present investigation was to study the suitability of the salivary activity of lysozyme and salivary peroxidase for monitoring the inflammatory state of the gingiva. Salivary peroxidase and lysozyme activities in resting whole saliva were measured in a group of 140 male subjects (aged 18-30 years). A full mouth, clinical assessment of the plaque index (PI) and the sulcus bleeding index (SBI) was made and gingival crevicular fluid (GCF) flow was measured at teeth 16, 12, 24, 36, 32 and 44 with the Periotron 6000. There were no significant differences in the mean values of lysozyme and salivary peroxidase activities between groups with different PI, SBI and GCF flow values. Statistically significant correlations were found among the clinical parameters, with SBI and PI showing the strongest relation (r = 0.47). The correlation between GCF flow and PI was higher (r = 0.43) than the correlation between GCF flow and SBI (r = 0.20). However, there were no statistically significant correlations between the activities of salivary peroxide and lysozyme and the clinical measures of gingival health.

Matrix metalloproteinase 2 (gelatinase A) is related to migration of keratinocytes

The role of matrix metalloproteinases (MMPs) in cell migration was studied by measuring cell growth, migration, and production of MMP-2 and -9 in oral mucosal and skin keratinocytes cultured in the presence of synthetic MMP inhibitors. MMP-2 was the major gelatinolytic MMP produced by these cells while MMP-9 was produced at a low basal level. Inhibitor effects on MMP-9 production were therefore studied in keratinocytes stimulated by tumor necrosis factor alpha (TNFalpha). Tetracycline analogues at concentrations that inhibited the production of MMP-2 but not MMP-9 were able to drastically inhibit migration of both mucosal and skin keratinocytes. Tetracycline analogues also inhibited keratinocyte growth, an effect not found for the other inhibitors tested. Heterocyclic carbonate-derived compounds (LWs) that inhibited MMP-9 but not MMP-2 production had no effect on cell migration. Batimastat, a potent MMP inhibitor, did not have any effect on MMP production or cell growth but did inhibit keratinocyte migration. Tumor growth factor beta (TGFbeta) increased keratinocyte migration as well as both cell-associated and secreted MMP-2 production in wounded cell cultures. The secreted enzyme was partially converted into an active form. In this model batimastat totally blocked TGFbeta-promoted keratinocyte migration. Immunostaining of keratinocytes advancing into the wound revealed that MMP-2 was localized in extracellular matrix contactlike structures against the endogenously produced laminin-5-rich matrix. MMP-9 was localized diffusely along the cell membranes. Using in situ hybridization we observed that in chronically inflamed human gingiva MMP-2 is expressed in epithelium extending into subepithelial connective tissue. These results suggest that MMP-2 plays a specific role in epithelial migration, possibly by detaching the advancing cells from the pericellular matrix or by activating other MMPs.

Activation of neutrophil collagenase in periodontitis

Neutrophil collagenase (matrix metalloproteinase 8 [MMP-8]) is an important mediator of tissue destruction in inflammatory diseases. Studies of anaerobic periodontal infections have shown that active MMP-8 in gingival crevicular fluid is associated with the degradation of periodontal tissues in progressive periodontitis whereas the latent enzyme is predominant in gingivitis. Since the activation of MMP-8 appears to be a crucial step in periodontitis, we have examined the activation of MMP-8 in gingival crevicular fluid samples by using a soluble biotinylated collagen substrate. Analysis of gingival crevicular fluid in periodontitis, gingivitis, and controls revealed sixfold (P < 0.001)-higher levels of active collagenase in periodontitis (n = 12) samples compared to gingivitis (n = 17) samples, which exhibited low levels of activity, while controls (n = 25) showed no activity. After gingival crevicular fluid was collected, no further activation of latent collagenase occurred in vitro. Although both MMP-1 and MMP-8, but not MMP-13, could be detected by immunoblots, blocking antibodies to MMP-1 showed that collagenase activity was largely contributed by MMP-8, which was localized to the matrix of diseased tissues. The MMP-8 in gingival crevicular fluid migrated primarily as a 60-kDa form with smaller amounts of a 78-kDa species, whereas MMP-8 isolated from peripheral neutrophils migrated at 70 and 89 kDa, corresponding to active and latent forms of the enzyme, respectively. Most of the MMP-8 in the 60- and 70-kDa bands selectively bound to tissue inhibitor of metalloproteinase 2 and collagen, indicating that most, but not all, of the enzyme in these bands was in an activated form. However, the amounts of the 78- and 60-kDa forms from gingival crevicular fluid in different samples did not correlate (r2 = 0.028) with the latent and active enzyme measured by collagenase assay. Collectively, these studies have identified distinct forms of latent and active MMP-8 in gingival crevicular fluid that appear to result from a unique activation mechanism that occurs in periodontitis. The complexity of MMP-8 activation is further indicated by the presence of latent, activated, and superactivated forms of MMP-8 in the 60- and 70-kDa bands obtained from gingival crevicular fluid and neutrophil samples, respectively.

Tissue inhibitors of metalloproteinases level and collagenase activity in gingival crevicular fluid: the relevance to periodontal diseases

OBJECTIVES

To provide an overall assessment of levels of tissue inhibitors of metalloproteinases (TIMPs), collagenase activities, and of immuno-reactivities for matrix metalloproteinases (MMP)-1 and -8 in gingival crevicular fluid (GCF) obtained from healthy subjects, and gingivitis and periodontitis patients, and to analyse the relationships between periodontal tissue destruction and the GCF components in periodontal diseases by principal component analysis.

MATERIALS AND METHODS

GCF was sampled with sterile paper strips from 10 gingivitis and 11 periodontitis patients. Ten volunteers served as clinically healthy controls. TIMP-1 and -2 protein amounts in GCF were measured by ELISA, and active and APMA-activatable collagenase activities were determined by functional assays using image-analysis after SDS-PAGE.

RESULTS

GCF TIMP-1 level and both active and latent collagenase activities were significantly higher in the diseased groups than in the healthy group. TIMP-2 was detectable in only 29% of all subjects (mean: 2.06 ng). Western blot analysis showed that MMP-8 was the major interstitial collagenase in the GCF of the diseased groups. Principal component analysis using clinical parameters and the GCF components has indicated components one to three account for 87% of total variation when evaluating the relevance of their measurements to periodontal diseases.

CONCLUSIONS

We conducted the functional and immunological characterization of MMPs and TIMPs in the GCF of periodontally diseased patients. Principal component analysis indicated components one to three explaining 87% of total variation, and further suggested that higher collagenase activity (especially in active collagenase) would be an important marker in evaluating the pathogenesis of periodontitis. Consequently, these observations may have significant therapeutic and diagnostic implications.

Crevicular fluid level of beta-glucuronidase in relation to clinical periodontal parameters and putative periodontal pathogens in early-onset periodontitis

Analysis of beta-glucuronidase (betaG) in the gingival crevicular fluid (GCF) provides an indication of neutrophil influx into the crevicular environment. The aim of this study was to test the hypotheses that: (1) betaG is significantly elevated in individuals with early-onset periodontitis (EOP) and that betaG activity correlates with disease severity; and (2) betaG level may reflect the local bacterial challenge in the gingival crevice. The study subjects consisted of a sub-sample of individuals examined in the National Survey of Oral Health of United States Children, which was undertaken during the 1986/87 school year. A total of 249 individuals were selected based on presence or absence of clinical attachment loss at baseline. The individuals were examined a second time 6 years later and the clinical attachment loss was assessed, and subgingival plaque and GCF were collected. The subjects were classified into 3 types of EOP and a control group. BetaG activity in the GCF and the levels of 7 putative micro-organisms in the pocket were assessed. The generalized EOP group had the highest betaG activity, followed by the localized and incidental EOP groups, and the controls, respectively. There was a significant increase in betaG activity with the increase in probing depth. Also, sites with bleeding on probing had a significantly higher betaG activity than sites without bleeding. However, the effect of gingival inflammation on betaG activity was more evident in the generalized and localized EOP groups. Sites harboring high levels of one or more of the micro-organisms tended to have high betaG activity. There were moderate differences between the organisms with respect to their effect on betaG activity, but sites with high numbers of Porphyromonas gingivalis, Prevotella intermedia, or Treponema denticola also had the highest betaG activity. The present findings suggest that betaG activity in GCF from patients with EOP can be of value in the early identification of individuals at higher risk of developing EOP The findings also suggest that host mechanisms leading to higher betaG activity in EOP represent systemic responses and are only partly related to the presence of local factors at the site-level.

Activity and inhibition of elastase in GCF

The aim of this study was to investigate the presence of free elastase in GCF Samples were taken from inflamed sites in 12 subjects with gingivitis alone and from inflamed sites with and without tissue destruction in 19 patients having periodontitis. Elastase activity was measured with a low molecular weight substrate. To distinguish between free elastase and elastase bound to alpha-2-macroglobulin (A2MG), an excess of alpha-1-antitrypsin (A1AT) was added to the samples. The activity that could be inhibited by A1AT was considered as free elastase, and the uninhibited activity as derived from the elastase-A2MG complex. The elastase-A1AT complex was measured with an ELISA. Free elastase was found in almost all samples, but both the total amount and the proportion of free elastase were higher in samples from sites showing destruction. The elastase-A2MG complex was also increased in sites with tissue destruction, while there was no significant difference in the amount of A1AT complex between the 3 categories of sites. In conclusion, our study clearly reveals free elastase in GCF The elevated levels of free elastase in sites showing tissue destruction seem to be due to a combination of increased release of elastase and an inactivation of A1AT.

Collagenase-3 (matrix metalloproteinase-13) expression is induced in oral mucosal epithelium during chronic inflammation

Increased proliferation of mucosal epithelium during inflammation is associated with degradation of subepithelial connective tissue matrix and local invasion of the epithelial cells. Here we have studied, whether collagenase-3 (MMP-13), a collagenolytic matrix metalloproteinase with an exceptionally wide substrate specificity, is expressed in the epithelium of chronically inflamed mucosa. Examination of human gingival tissue sections from subjects with chronic adult periodontitis with in situ hybridization revealed marked expression of MMP-13 in basal cells of some epithelial rete ridges expanding into connective tissue. Immunohistochemical staining demonstrated that these cells also expressed strongly laminin-5, suggesting that they are actively migrating cells. A strong signal for MMP-13 mRNA was occasionally also noted in the suprabasal epithelial cells facing the gingival pocket, whereas no collagenase-1 (MMP-1) mRNA was detected in any areas of the epithelium. MMP-13 expression was also detected in fibroblast-like cells associated with collagen fibers of the inflamed subepithelial connective tissue. In organ culture of human oral mucosa, MMP-13 mRNA expression was observed in epithelial cells growing into connective tissue of the specimens. Regulation of MMP-13 expression was examined in cultured normal nonkeratinizing epithelial cells isolated from porcine periodontal ligament. In these cells, MMP-13 expression at the mRNA and protein level was potently enhanced (up to sixfold) by tumor necrosis factor-alpha, transforming growth factor-beta(1), and transforming growth factor-alpha and by keratinocyte growth factor in the presence of heparin. In addition, plating periodontal ligament epithelial cells on type I collagen stimulated MMP-13 expression (sevenfold) as compared with cells grown on tissue culture plastic. The results of this study show, that expression of MMP-13 is specifically induced in undifferentiated epithelial cells during chronic inflammation due to exposure to cytokines and collagen. Thus, it is likely that MMP-13 expression is instrumental in the subepithelial collagenolysis and local invasion of the activated mucosal epithelium into the connective tissue.

Association of crevicular fluid elastase-like activity with histologically-confirmed attachment loss in ligature-induced periodontitis in beagle dogs

Experimental periodontitis was induced using ligatures in 6 beagle dogs over 57 days. Levels of elastase like activity in healthy sites, gingivitis sites, and in sites ligated for different time points were analyzed with respect to levels of histologically confirmed attachment loss. Attachment loss increased with increasing periods of ligation and reached a maximum of 0.15 mm at 57 days. Maximum loss of histological attachment was found to coincide with the period of maximum enzyme activity; during the first 7 days of ligature. Spearman correlation analysis of enzyme activity with attachment loss yielded a significant correlation (0.73, p=0.0396). The healthy and gingivitis sites were found to have minimal levels of enzyme activity throughout. Thus, this prospective study in beagle dogs found a relationship between histologically confirmed attachment loss and increased levels of elastase like activity indicating the probable usefulness of this parameter, either alone or in conjunction with other markers, for disclosing active periodontitis.

Advances in periodontal diagnosis. 8. Commercial diagnostic kits based on GCF proteolytic and hydrolytic enzyme levels

Biomarkers of periodontal disease activity may be obtained from potential proteolytic and hydrolytic enzymes of inflammatory cell origin. Commercial diagnostic tests and those under development are discussed along with their advantages and disadvantages.

Protease activity in gingival crevicular fluid: presence of free protease

Our aim was to study protease activity in GCF from inflamed sites with or without tissue destruction. 19 patients with both periodontitis and gingivitis sites and 12 patients having gingivitis alone participated in the study. GCF samples were collected by an intracrevicular washing method. The protease activity was measured as degradation of FITC-conjugated casein. To obtain a semiquantitative estimate of the harvested GCF volume, we measured the transferrin concentration in the wash-fluid. The protease activity was significantly higher in the deep pockets in periodontitis patients than in shallow pockets in the same patients. This difference was still higher when the ratio of protease activity to the amount of transferrin in the sample was plotted. Although protease activity was lower in samples from gingivitis patients than in the deep pockets in periodontitis patients, the difference was not significant. About 90% of the activity could be inhibited by the addition of an excess amount of alpha-1-antitrypsin (A1AT). This study shows that protease activity is higher in inflamed sites with tissue destruction than in inflamed sites without. Most of this activity could be inhibited by A1AT, which suggests that the activity is due to an imbalance between protease and antiprotease rather than to proteases insensitive to A1AT.

[The treatment of periodontal diseases using Diplen-Denta films with chlorhexidine (a clinico-laboratory study)]

Diplen-Denta biopolymer adhesive film with chlorohexidine-was used in the treatment of periodontal inflammations of different severity. The efficacy of treatment of gingivitis and periodontitis is assessed from changes in the clinical parameters and in the activity of neutrophil elastase in the gingival liquid. The new treatment is highly effective in patients with catarrhal gingivitis and generalized periodontitis of light and medium severity.

Effects of the anti-androgen finasteride on 5alpha-reductase activity in human gingival fibroblasts in response to minocycline

In addition to their antimicrobial properties, tetracyclines have antiinflammatory and pro-anabolic effects on the reparatory potential of connective tissue and bone. The physiologically active androgen 5alpha-dihydrotestosterone (DHT) implicated in matrix synthesis is formed in gingivae from androgen substrates. The aim of this investigation is to study the androgen metabolic response of gingivae to minocycline, in the presence or absence of the anti-androgen finasteride. Chronically inflamed gingival tissue derived from 12 subjects aged 30-50 years and passaged fibroblasts derived from this source, were used for the experiments. Duplicate incubations were performed in Eagle's MEM with 14C-testosterone/14C-4-androstenedione in the presence or absence of minocycline (5-60 microg/ml) or finasteride for 24 h. The androgen substrate 14C-testosterone was metabolised mainly to DHT and 4-androstenedione, while 14C-4-androstenedione was converted mainly to DHT and testosterone. Minocycline at 20-30 microg/ml stimulated the formation of these metabolites from both substrates by 13-25%. In the tissue incubations there were 3- and 2-fold increases in DHT and 4-androstenedione formation (n=12; p<0.01). The anti-androgen finasteride caused significant inhibition of 5alpha-reductase activity on both substrates at 0.1 & 1.0 microg/ml with total inhibition at 10 & 50 microg/ml (n=3; p<0.01). Minocycline-induced stimulation of 5alpha-reductase activity was also inhibited by finasteride (n=4; p<0.02). Since finasteride inhibition of 5alpha-reductase activity is specific for the type 2 isoenzyme associated with anabolic functions of target tissue, this enzyme activity may contribute to some of the cited anabolic tissue responses to minocycline.

Effect of an encapsulated anti-elastase compound on experimental gingival inflammation in the rat

An animal (rat) model of gingival injury ("impaction") induced a gingival inflammatory reaction, which was characterized by a breakdown of gingival collagen and the elastic network, as well as a significant increase of gingival elastase. The present study was conducted to investigate whether ceramides, sphingolipids composed of sphingosine N-acyl-linked to fatty acids, a chemical structure with antielastase properties, could counteract the development of such an inflammatory process. The ceramides used in these experimental series were extracted from wheat and characterized. The main fatty acids were 16:0, 18:1, 18:2, and the sphingoid moiety was phytosphingosine. Inhibition of elastase by ceramides was demonstrated in vitro and the concentration necessary to inhibit 50% of elastase activity was 41 mg/l using the synthetic substrate methoxysuccinyl-alanine-alanine-proline-valine-p-nitroanilide (MeOSuc-AlaAlaProValpNA). However, this anti-elastase activity was not observed in vivo in our animal model of gingival inflammation. A glycosaminoglycan (Heparin), recognized as a potent inhibitor of elastase, was entrapped in ceramides. A local treatment of impacted gingivae by encapsulated heparin led to a dose-related decrease of the elastase level in gingival extracts. Encapsulation in ceramides potentiated the effect exerted by heparin alone. This inhibitory effect of encapsulated heparin on elastase suggested a vector effect of these amphipathic molecules.

In situ hybridization study on tissue inhibitors of metalloproteinases (TIMPs) mRNA-expressing cells in human inflamed gingival tissue

This study presents the exact cell types and localization of tissue inhibitors of metalloproteinases (TIMPs) production sites in periodontal diseased gingiva by means of in situ hybridization. Gingival tissue specimens were fixed, embedded and hybridized in situ with specific digoxigenin-labeled cRNA probes (386 and 496 bp). TIMP-1 and -2 mRNAs were expressed on macrophages, mononuclear cells, capillary endothelial cells and some fibroblasts throughout the gingival tissue. In periodontitis, TIMP-1 and -2 mRNA-expressing cells showed significantly different localization. TIMP-1 mRNA was broadly observed in the gingival connective tissue while TIMP-2 mRNA was predominantly expressed in the connective tissue adjacent to the pocket epithelium (p < 0.01). Fewer TIMPs mRNA were observed in minimal gingivitis than in periodontitis, especially in the middle zone of gingival tissue. Thus, TIMP-1 and TIMP-2 mRNA was detected differentially and site-specifically in periodontal diseased gingival tissue.

Effects of nonopsonized Escherichia coli on myeloperoxidase activity in medium used for incubation of leukocytes from patients with gingivitis and periodontitis

An attempt was made to explore the myeloperoxidase (MPO) activity in medium used for incubation of peripheral venous blood (PVB) leukocytes from patients with gingivitis and periodontitis and to compare it with that of periodontally healthy subjects. The study population included 54 gingivitis patients (G), 52 periodontitis patients (P) and 52 control subjects (C). All these groups were assessed by clinical, laboratory and statistical methods. The leukocytes were incubated with opsonized zymosan, Escherichia coli ATCC25922, nonopsonized E.coli or Staphylococcus aureus 256. The respective levels of MPO activity in incubation media of PVB leukocytes taken from group G patients were 598.0 +/- 29.2 conventional units (c.u.), 640.0 +/- 26.3 c.u., 662.0 +/- 37.6 c.u. and 750.0 +/- 40.8 c.u. (control incubation medium: 564.0 +/- 25.1 c.u.); those for group P patients were 672.0 +/- 34.3 c.u., 678.0 +/- 43.1 c.u., 692.0 +/- 47.9 c.u. and 762.0 +/- 34.7 c.u. (control: 612.0 +/- 35.2 c.u.); those for group C subjects were 556.0 +/- 30.2 c. u., 714.0 +/- 28.2 c.u., 1276.0 +/- 69.0 c.u. and 794.0 +/- 47.1 c.u. (control: 534.0 +/- 29.0 c.u.). MPO activity was increased most significantly when nonopsonized E.coli was added to the incubation medium of PVB leukocytes taken from subjects with intact periodontium. MPO activity was unchanged when the leukocytes were taken from periodontitis patients.

Immunohistochemical study of cathepsin G and medullasin in inflamed gingival tissues from periodontal patients

Cathepsin G and medullasin are 2 major serine proteinases associated with the granular fraction of polymorphonuclear leukocytes (PMNs). To know their possible involvement in the pathophysiological gingival connective tissue turnover, we have determined the distribution and localization of these 2 enzymes in inflamed gingival tissues from periodontal patients by immunohistochemistry with discriminating antibodies specific for each enzyme. The gingival connective tissues were obtained from periodontitis patients with various inflammatory conditions and control healthy subjects without any clinical signs of periodontal inflammation. In all gingival specimens examined, cathepsin G and medullasin were found mainly in neutrophil-like cells and partly in macrophage-like cells. No positive staining for both enzymes was obtained in endothelial cells and fibroblasts in every part of the gingival tissues. Immunoreactivity for each enzyme in the gingival tissues from the periodontitis group was stronger and greater in the intensity and frequency than that from the control group and appeared to be increased with the severity of the disease In both groups, the number of immunoreactive cells for each enzyme was greater in the vicinity of pocket epithelium (zone I) than in the area of central connective tissue (zone II) or the area subjacent to the oral epithelium (zone III). While both enzymes in zones II and III were exclusively found in coarse granules, their stainings in zone I were not only coarse but also diffuse. These results strongly suggest that both enzymes may have some association with inflamed gingival tissue degradation.

Matrix metalloproteinases-1 and -8 and TIMP-1 mRNA levels in normal and diseased human gingivae

Interstitial collagenases, including matrix metalloproteinase-1 (MMP-1) and -8 (MMP-8), serve as initiators of extracellular matrix destruction in periodontal disease. Collagenase activities are mainly regulated by tissue inhibitors of metalloproteinases (TIMPs). We tested the effects of inflammation on MMP-1 and MMP-8 gene expression in periodontal disease. To determine the relative abundance of these mRNAs in gingiva, we used a reverse transcription-polymerase chain reaction (RT-PCR) assay. Gingival biopsies were divided into 2 groups; a control group and an inflamed group with severe gingivitis or periodontitis. The MMP-1 mRNA levels were significantly elevated in inflamed gingiva, while the levels of the MMP-8 transcript were not different in the 2 groups and barely detectable by RT-PCR assay. The expression of the TIMP-1 gene was not altered, and remained higher than any of these other genes in both control and diseased gingivae. These results suggest that MMP-1 rather than MMP-8 may play an important role in the initiation of collagen degradation in periodontal disease. However, the possibility remains that MMP-8 plays an important role in periodontal tissue destruction, since the mRNA abundance and not the enzyme activity was assessed.

[Activity of glutamate dehydrogenase, gamma-glutamyltranspeptidase and creatine kinase in saliva in gingivitis]

In the human saliva (oral fluid), the activity of glutamate dehydrogenase tends to decrease in gingivitis and diminishes in periodontitis. That of gamma-glutamyl transpeptidase and creatine kinase increases in gingivitis. In periodontitis, their activity is higher than that in gingivitis. The above changes in enzymatic activities reflect metabolic changes in the gingiva and periodontium in inflammation. The saliva from the salivary ducts shows no activity of the above enzymes. They enter the mixed saliva (oral fluid) together with epithelial and other oral tissue cells, with leukocytes and microbes which manifold in gingivitis.

Histochemical and immunocytochemical localization of dipeptidyl peptidases II and IV in human gingiva

Dipeptidyl peptidase (DPP) II and IV activities were demonstrated in unfixed cryostat sections of gingival tissue from chronic periodontitis patients using histochemistry with 2-methoxy-4-naphthylamine (MNA) substrates. In the case of DPP IV, enzyme localization was confirmed by immunocytochemistry with mouse monoclonal antihuman DPP IV (CD26) antibody. Inflammatory cells containing enzyme were identified in adjacent sections with mouse monoclonal antibodies directed against leukocyte differentiation antigens. Lys-Ala-MNA and Ala-Pro-MNA staining in acid buffer for DPP II was only found in a few fibroblasts in superficial tissue. Staining with Gly-Pro-MNA and Ala-Pro-MNA in alkaline buffer for DPP IV was localized in some CD4 and CD8 positive T lymphocytes, CD68 positive macrophages, and fibroblasts and these cells also reacted with the enzyme antibody. DPP IV-containing macrophages and T lymphocytes were seen in the epithelium. In deeper granulomatous tissue Gram positive and negative bacteria stained with the histochemical substrates, but not the DPP IV antibody. Fibroblast DPP II and IV might participate in cellular interactions with collagen, while T lymphocyte DPP IV may be involved in cell signalling.

Characterization of matrix metalloproteinase (MMP-8 and -9) activities in the saliva and in gingival crevicular fluid of children with Down's syndrome

Previous studies have shown increased susceptibility to periodontal diseases in children with Down's syndrome (DS). The mechanisms involved in the periodontal inflammatory processes in DS are not fully understood. The present study characterized the periodontal status of 9 non-institutionalized DS children 9 to 17 years old (mean 13.6 years) relative to their age-matched systemically and periodontally healthy controls. The periodontal status was assessed by visible plaque index (VPI), gingival bleeding index (GBI), and probing depth. We also assessed, by sodium dodecyl sulphate polyacrylamide gel electrophoresis/laser densitometry and by zymography, the collagenase and gelatinase activities in the gingival crevicular fluid (GCF) and saliva samples collected from DS patients and from the controls. Eight of the nine DS children showed a periodontium comparable to that seen in healthy controls; beginning alveolar bone loss was radiographically seen in the DS patient with deep periodontal pockets. The endogenously active collagenase and total collagenase activities were slightly higher in GCF of DS children compared to healthy controls. Western blot demonstrated that GCF collagenase of DS patients was human neutrophil collagenase (MMP-8 or collagenase-2), which occurred in 75 kDa proMMP-8 and in DS patients, but not in controls, also in 65 kDa active MMP-8 form and occasionally lower 40-50 kDa MMP-8 species. Zymographic analysis revealed the presence of 120 kDa (MMP-9 complexed with neutrophil gelatinase associated lipocalin or NGAL), 92 kDa (MMP-9) and 72 kDa (MMP-2) gelatinases in DS and control GCF. Especially in DS GCF MMP-9 occurred in part in 82-85 kDa activated form. Salivary collagenase in DS was high when compared to controls but of the same MMP-8 type as in control saliva. Our findings suggest that in vivo activated MMP-8 in GCF derived from triggered PMNs and/or cytokine-induced periodontal fibroblasts may reflect periodontal tissue and alveolar bone destruction seen in the early stages of gingivitis/periodontitis associated with Down's syndrome.

Chemiluminescent assay of alkaline phosphatase in human gingival crevicular fluid: investigations with an experimental gingivitis model and studies on the source of the enzyme within crevicular fluid

The purpose of this study was to investigate how levels of gingival crevicular fluid (GCF) alkaline phosphatase (ALP) change in relation to levels of plaque and gingival inflammation in 20 adults during a 21 day period of experimental gingivitis. The source of ALP within GCF was also investigated using a repeat sampling protocol; by determining enzyme levels derived from 30 putative periodontal pathogenic and non-pathogenic species; and by examining inhibition profiles from a variety of host and bacterial ALP isoenzymes. Total 30-s GCF ALP levels increased significantly (p < 0.002) during experimental gingivitis and preceded an increase in gingival index (GI) by approximately 7 days. Enzyme levels correlated with GCF volume (R = 0.7; p < 0.0001), but repeat sampling indicated that entry of ALP into the gingival crevice was independent of the rate of fluid flow. Only 5 of the bacterial species investigated produced clearly detectable levels of ALP in culture supernatants, these were P. gingivalis (381), P. intermedia (581), P. nigrescens (8944), Dentin P. gingivalis (TW 471: clinical isolate) and C. ochracea (25). Levamisole inhibition and studies on suspensions of washed plaque demonstrated that host-derived ALP contributed to > 80% of the enzyme in GCF. We conclude that elevated 30-s GCF ALP levels measured using the chemiluminescent assay reported, are detectable before increases in gingival indices and appear to be a better marker of gingival inflammation than ALP concentrations. The major source of ALP within GCF is host derived and in early inflammatory disease is likely to be of polymophonuclear leukocyte origin.

Crevicular fluid enzymes from endosseous dental implants and natural teeth

Several neutrophil-derived enzymes that are present in the gingival crevicular fluid have been evaluated for use as risk markers for periodontal disease progression. However, very little information is available about the presence of these enzymes in peri-implant tissues. The purpose of this cross-sectional study was to compare levels of enzymes in gingival crevicular fluid between natural teeth and endosseous dental implants and between well-integrated and failing implants. Scores of plaque and gingivitis were recorded for 68 integrated implants, five failing implants, and 34 natural teeth in 12 completely edentulous and 18 partially edentulous subjects. Samples of gingival crevicular fluid were obtained from these sites using filter paper strips and were assayed for levels of neutral protease, neutrophil elastase, myeloperoxidase, and beta-glucuronidase. Neutral protease levels were higher (P = .066) at moderately to severely inflamed implant sites (Gingival Index of 2, 3) compared to mildly or noninflamed sites (Gingival Index of = 0, 1). Despite the small number (n = 5) of failing implants evaluated in this study, levels of neutrophil elastase, myeloperoxidase, and beta-glucuronidase were significantly higher (P < or = .001) around failing implants compared to successful implants. Neutral protease levels were also elevated around failing implants, but the difference was not statistically significant. Results of this study indicate that neutrophil elastase, myeloperoxidase, and beta-glucuronidase levels in GCF appear to be good candidates for study as risk markers of implant failure.

The measurement of acid and alkaline phosphatase in gingival crevicular fluid during orthodontic tooth movement

This study examines acid and alkaline phosphatase activities in gingival crevicular fluid (GCF) to learn whether bone turnover dynamics can be monitored in human subjects during orthodontic tooth movement. Three female subjects were observed longitudinally to assess tooth movement, plaque, and inflammation. For each subject, one randomly selected premolar served as the control and was not treated, and another was moved buccally with 100 gm of force. The GCF was collected weekly and assayed for phosphatases. Alkaline phosphatase peaked between the first and third weeks, followed by an increase in acid phosphatase between the third and sixth weeks. After the first week, tooth movement averaged 0.9 mm. Additional 0.9 mm of movement occurred during the next 3 weeks, followed by 1.4 mm during weeks 4 to 6. Thirty additional patients, randomly divided into headgear/biteplate, bionator, and control groups, were also sampled cross-sectionally at the maxillary first molars. The GCF phosphatase activities were assessed as functions of location on the tooth, treatment modality, duration of treatment, gingival inflammation, and plaque accumulation. The plaque index did not show a relationship to either acid or alkaline phosphatase activity on the mesial or distal in the treated groups. However, alkaline phosphatase increased with inflammation on the distal in treated groups and acid phosphatase was consistently higher on the mesial than on the distal in the treatment groups. Alternating peaks of acid and alkaline phosphatase were found in the GCF of treated teeth as functions of treatment duration. The sequence of these changes is similar to that reported for alveolar bone turnover in a rodent orthodontic tooth movement model. We conclude that phosphatase activities in GCF may be a useful means for monitoring tissue responses to orthodontic treatment.

Cathepsin G in gingival tissue and crevicular fluid in adult periodontitis

The presence, localization and activities of cathepsin G in gingival tissue specimens and crevicular fluid (GCF) from 9 adult periodontitis patients and 6 controls with clinically healthy periodontium were studied by use of avidinbiotin-peroxidase complex method, Western and dot blotting, and spectrophotometric activity assay. In contrast to healthy gingival tissue specimens, gingival tissue specimens collected from adult periodontitis patients contained inflammatory cells in lamina propria, beneath the oral sulcular epithelium, 10-50% of which were cathepsin G positive polymorphonuclear neutrophilic leukocytes (PMNs) and monocyte/macrophage-like cells. Cathepsin G activities were increased in adult periodontitis GCF when compared to periodontally healthy controls' GCF (p < 0.05). In adult periodontitis GCF, Western blotting disclosed free cathepsin G but also clear complexes of cathepsin G with its predominant endogenous inhibitor alpha 1-antichymotrypsin (alpha 1-ACT). The present results demonstrate that part of the cathepsin G, despite the presence of increased concentrations of alpha 1-ACT, was in an uncomplexed, free and functionally active form. Our results suggest that GCF cathepsin G reflects the disease process in adjacent inflamed gingiva and also increased host response to microbiota and/or dental plaque in the periodontitis lesions. Cathepsin G may contribute to periodontal tissue destruction directly and indirectly, via proteolytic activation of latent neutrophil procollagenase (promatrix metalloproteinase-8 [proMMP-8]).

The effect of non-surgical periodontal and adjunctive minocycline-HCL treatments on the activity of salivary proteases

The purpose of this investigation was to evaluate the effect of non-surgical periodontal treatment and adjunctive systemic minocycline therapy on the level of neutral protease activity in whole saliva of adults with periodontitis. A test group of 21 adult patients with moderate to severe periodontitis was compared to a control group of 5 adults with healthy periodontium. Four test groups were examined: 1) scaling and root planing (SRP), probing depth = 4 to 5 mm; 2) SRP, PD > or = 6 mm; 3) SRP and adjunctive systemic minocycline therapy, PD = 4 to 5 mm; 4) SRP and adjunctive systemic minocycline therapy, PD > or = 6 mm. Clinical parameters and levels of neutral protease in whole saliva were assessed at baseline and on the sixth week after the non-surgical periodontal treatment. Neutral protease activity was measured by spectrofluorimetric method. Statistical tests of Mann-Whitney and Spearman Rank correlation coefficient were used in the evaluation of the mean values of measurements. The mean values of protease activity were significantly higher in the test groups than in the control group at baseline. Six weeks after non-surgical therapy, patients with 4 to 5 mm probing depth had approximate values of protease activity comparable to the control group. Hence it can be argued that these patients did not need minocycline HCL as an adjunctive therapy. However, non-surgical therapy had limited effects on both clinical parameters and enzyme activities for subjects with > or = 6 mm probing depth; on the other hand, gingival inflammation and enzyme activities were reduced significantly by the usage of minocycline as adjunctive therapy in these patients. According to our results, neutral protease activity in saliva is related to probing depth and gingival bleeding index, and not related to age and epithelial cell number. For these reasons, systemic minocycline therapy might be useful as an adjunct to non-surgical therapy in the presence of deep pockets, especially for reinfected cases. Further investigations are needed to confirm this suggestion.