Junichi Otogoto

Differential Expression of RANKL and Osteoprotegerin in Gingival Crevicular Fluid of Patients with Periodontitis

The receptor activator for NF-κB ligand (RANKL) plays an important role in osteoclast formation. A recent study with animal models suggests the involvement of RANKL in the pathogenesis of this periodontal disease. However, no one has examined the level of RANKL in the body fluid of human subjects. This communication reports on the in vivo concentrations of RANKL and the RANKL decoy receptor osteoprotegerin (OPG) in the gingival crevicular fluid (GCF) of periodontal subjects with severe, moderate, and mild forms of the disease. An increased concentration of RANKL and a decreased concentration of OPG were detected in GCF from patients with periodontitis (*p < 0.05 vs. control subjects). The ratio of the concentration of RANKL to that of OPG in the GCF was significantly higher for periodontal disease patients than for healthy subjects (*p < 0.01). Taken together, these data suggest that RANKL and OPG contribute to osteoclastic bone destruction in periodontal disease. Abbreviations: GCF, gingival crevicular fluid; IL, interleukin; OPG, osteoprotegerin; RANKL, receptor activator for NF-κB ligand.

Interleukin 1β, interleukin 6, β2-microglobulin, and transforming growth factor-α in gingival crevicular fluid from human periodontal disease

Inflammatory mediators are central to the pathogenesis of periodontal diseases and may be used as markers in diagnosis. The aim of this study was to identify and quantify the various growth factors, apoptosis-related modifiers [soluble form of Fas (sFas) and bcl-2] and cytokines in the gingival crevicular fluid (GCF) of patients with different severities of periodontitis as compared with those of controls. GCF samples were taken from patients with periodontal disease and from controls. The concentrations of epidermal growth factor, transforming growth factor (TGF)-alpha, interleukin (IL)-1 beta, IL-6, interferon-gamma, beta 2-microglobulin (beta 2-MG), and apoptosis-related modifiers sFas and bcl-2 in the samples were determined by enzyme-linked immunosorbent assay. TGF-alpha was significantly lower in patients with periodontal disease than in the controls. In contrast, the concentrations of IL-1 beta, IL-6; and beta 2-MG were significantly higher in the group with severe periodontal disease than in the controls. The amount of total protein in the GCF was considerably higher in the disease group than the controls (p < 0.05). TGF-alpha, IL-1 beta, and beta 2-MG concentrations were associated (Spearman rank correlation, r < 0.05 for all) with clinical measures of disease severity (pocket depth) and inflammation (bleeding when probed). Apoptosis-related modifiers (sFas and bcl-2) could not be detected in any samples. These results suggest that the growth factor TGF-alpha and certain cytokines are associated with the presence of periodontal disease.

Cloning and functional expression of rat kidney dipeptidyl peptidase II.

Dipeptidyl peptidase II (DPP II; EC 3.4.14.2) from rat kidney was purified to a specific activity of 65.4 micromol/min per mg of protein for Lys-Ala-beta-naphthylamide. The N-terminal and partial amino acid sequences of the enzyme were determined. The peptide sequences were used to identify expressed sequence tag (EST) clones. By using the cDNA fragment of one of the EST clones as a probe, we isolated a cDNA clone with 1710 bp encoding DPP II from a rat kidney cDNA library. The cDNA of rat DPP II contained an open reading frame of 1500 bp, coding for a protein of 500 amino acids. The first 10 residues of the purified enzyme matched the deduced protein sequence starting with residue 37, suggesting the presence of a signal peptide. The mature enzyme (464 residues) had a calculated molecular mass of 51400 Da, which was lower than the value (about 60000 Da) determined by SDS/PAGE; and the deduced amino acid sequence showed six potential N-glycosylation sites. The deduced amino acid sequence of rat DPP II shared high similarity with quiescent-cell proline dipeptidase (78% identity) and prolyl carboxypeptidase (38% identity) and bore the putative catalytic triad (Ser, Asp, His) conserved in serine peptidase families. We transiently transfected COS-7 cells with pcDNA3.1 containing the cloned cDNA and obtained the overexpression of an immunoreactive protein (of about 60000 Da). The transfected cells showed Lys-Ala-methylcoumarinamide-hydrolysing activity that was 50 times higher than the control cells.

Drop in Transforming Growth Factor-α and Osteoprotegerin Level in Gingival Crevicular Fluid from Patients with Gingivitis

Abstract Inflammatory mediators, especially cytokine, play a central role in the pathogenesis of gingivitis. The aim of this study was to identify and quantify the various growth factors, and cytokines in the gingival crevicular fluid (GCF) of patients with gingivitis, as compared with those of control subjects. The levels of cytokine in the samples were determined by their respective ELISAs. The transforming growth factor (TGF)-α and osteoprotegerin (OPG) level were significantly lower in patients with gingivitis than in the controls (p < 0.05). Also, there was a positive correlation between TGF-α and OPG levels (r = 0.761). These results suggest that the decrease in growth factor TGF-α is associated with the pathophysiology and/or the progress of gingivitis.

The effect of enhanced Nd:YAG laser fiber tip for periodontal treatment

Abstract An activated Nd:YAG fiber tip using fiber-tip enhanced device (FTED) makes an activated and scattered irradiation beam. The enhanced (activated) fiber tip could be irradiated parallel to the target surface. The purpose of this study was to determine the effect of the activated laser fiber tip for calculus removal compared with other techniques. Specimens of extracted teeth with or without calculus were prepared. Nd:YAG laser power pulse 1 (SLT Japan, Tokyo, Japan) was used. The diameter of the optimal fiber was 400 μm. The enhanced condition was firstly examined using irradiation power from 100 to 900 mJ, 1 to 10 pps, in order to verify which is the best condition for calculus removal with scattering irradiation beam. Four types of calculus removal methods were compared: (1) hand curette; (2) ultrasonic scaler; (3) laser irradiation through a normal optimal fiber tip at 900 mJ, 10 pps, using a perpendicular irradiation mode with water coolant; (4) laser irradiation through the active fiber tip at 900 mJ, 10 pps, using a parallel irradiation mode with water coolant. After the roughness of the surfaces was clinically measured, the specimens were then prepared for scanning electron microscopy (SEM) observation. These results indicated that the best enhanced condition of the FTED for calculus removal with scattering irradiation beam was 800 mJ, 10 pps. The FTED was more useful for calculus removal than the normal fiber tip. However, it was less effective than hand and ultrasonic scaling considering the treatment time.