Characterization of fibromodulin isolated from bovine periodontal ligament

Although several proteoglycans (PGs) have been reported in bovine periodontal ligament (PDL), the composition of PGs in PDL has been poorly characterized. In the present study, we isolated and characterized keratan sulfate-substituted PG (fibromodulin) in bovine PDL. Fibromodulin was purified from 4 m guanidine hydrochloride (GdmCl) extracts of bovine PDL tissues using DEAE Sephacel ion-exchange chromatography and preparative electrophoresis. Fibromodulin appeared as a single polydisperse band with an apparent molecular weight (MW) of 80, 000 (80 kDa) on SDS-PAGE. Digestion of fibromodulin with keratanase or neuraminidase reduced the apparent molecular size, and N-glycanase treatment produced core protein bands of around 40 kDa. Fibromodulin reacted with keratan sulfate monoclonal antibody (5D4) and fibromodulin polyclonal antibodies (α-FM). The keratanase-digested fibromodulin reacted with α-FM, but not with 5D4. These data suggest that fibromodulin is one of the small PGs in the PDL-matrix and may fulfill construction and maintenance functions in this tissue.     

Mandibular stability after sagittal split ramus osteotomy without post-operative maxillomandibular fixation in the treatment of prognathic patients with symmetric mandibles

This study was designed to examine post-operative stability in prognathic patients with symmetric lower jaws who underwent sagittal split ramus osteotomy (SSRO) of the mandible without post-operative maxillomandibular fixation (MMF). Twenty prognathic patients with symmetric mandibles were investigated. An appliance for repositioning the proximal segment and titanium screw fixation was applied in all patients. Ten patients underwent post-operative MMF with stainless steel wire (mean duration, 9.6 days) and intermaxillary rubber traction after removal of the MMF (Group I), and the remaining ten underwent intermaxillary rubber traction only (Group II) post-operatively. Cephalograms were obtained 2–3 days post-operatively, and 3, 6, and 12 months after surgery. Changes in the positions of upper incisors (U-1), lower incisors (L-1), B-point, and pogonion were examined on lateral cephalograms. In the early stages of follow-up, decreases in the overbite tended to be more marked in Group I than in Group II, and the forward movement of each standard point was significantly larger in Group I than in Group II. No significant differences, however, were revealed between the two groups at 12 months after surgery. Forward movement of anterior cephalometric landmarks, post-operatively, in Group II were significant, however, this pattern differed from Group I, in which big changes occurred in the early stages after surgery. Although the patterns of post-operative changes in the two groups are different, there are no significant differences in their post-operative stability in long-term follow-up. Therefore, post-operative MMF may be avoided when prognathic patients with symmetric mandibles undergo SSRO with an appliance for repositioning the proximal segment and titanium screw fixation.     

Histopathological changes in collagen and matrix metalloproteinase levels in articular condyle of experimental model rats with jaw deformity

OBJECTIVE: To investigate the dynamics of the cartilage matrix in the articular condyle after removal of a side shift plate; Emergence of type I, II, and III collagen in the matrix as well as changes in levels of matrix metalloproteinase (MMP)-1, -8, and -13 that degrade collagen were studied histopathologically and immunohistochemically. DESIGN: Lateral displacement of the mandible was achieved by attaching a side shift plate to the anterior teeth of the maxilla in male rats at 6 weeks. The wearing period of the side shift plate was 8 weeks. Observations were made at 0, 1, 2, 4 and 8 weeks after removal. RESULTS: In histopathological findings, the timing of proliferation of the layer of hypertrophy varied between the bilateral sides. In immunohistochemical findings a significant decline in the expression of type II collagen in the displacement side was observed immediately after removal. Moreover, the expressions of MMPs were elevated in both sides on 0 weeks. At 1 week after removal, a significant elevated in the expression of type II collagen, MMPs was decline in both sides. CONCLUSIONS: After removal, the levels of MMP-1, -8, and 13 were reduced and the emergence of type II collagen increased. Thus, cellular outgrowth was initiated to trigger intracartilaginous ossification to restore the cartilage matrix.     

Heterogeneity of exo-type of beta-N-acetylglucosaminidase in human parotid saliva

The exo-type of β-N-acetylglucosaminidase (NAGase) in human parotid saliva was separated into two fractions, NAGase A and B, by diethylaminoethanol (DEAE)-cellulose column chromatography. The heterogeneity was confirmed by isoelectric focusing and disc electrophoresis. Isoelectric points of NAGase A and B were at pH 7.2 and 5.0, respectively. NAGase A was more heat-stable than NAGase B. A slight difference in pH optimum was found between NAGase A and B. Both components had almost the same Km values for p-nitrophenyl N-acetylβ-glucosaminide, p-nitrophenyl N-acetyl-β-galactosaminide, phenyl N-acetyl-β-glucosaminide and phenyl N-acetyl-β-galactosaminide.