Structure of intact chitinase with hevein domain from the plant Simarouba glauca, known for its traditional anti-inflammatory efficacy.

Chitinase from the leaves of Simarouba glauca, a plant used in traditional anti-inflammatory therapy is purified and characterized. Peptide mass finger print analysis revealed the protein as an endo-chitinase which was further confirmed using chitin-agar assay. The enzyme exhibited significant anti-fungal efficacy against phyto-pathogens such as Macrophomina phaseolina, Fusarium oxysporum and Sclerotium rolfsii. Chitinolysis was also examined against insoluble chitin using SEM. Using X-ray diffraction data up to 1.66 Å, the structure was determined by Molecular Replacement using crystal structure of GH19 Chitinase-like protein from Hevea brasiliensis. During structure refinement, an extra domain could be traced and identified as hevein domain. To our knowledge, this is the first report of any chitinase with intact hevein domain. The GH19 chitinase and hevein domains though connected by a lengthy loop, are restricted to be close by disulfide bridges. These bridges connecting each domain with the loop may be important for proper chitin feeding into the active site. By considering reports on hevein and chitinase domains as well as the traditional use of the plant, this report of an intact hevein-chitinase protein and their relative orientation may add further insights for the usefulness of this protein.

Guided bone regeneration in the treatment of fenestration osseous defect.

This article presents a case with a fenestration defect which was treated by placing a resorbable barrier alone. In the case presented, the osseous defect was a natural space maker with the wall of the defect providing sufficient support to prevent collapse of the membrane into the space. So the use of membrane alone is the preferred treatment. Resorbable collagen membrane was placed in order to avoid a second surgical procedure to remove the nonresorbable membrane. The membrane was positioned by placing a resorbable sling suture such that it covered the defective site adequately. Postsurgical healing of the defect was evaluated 1 month after the surgery and it was satisfactory. Thus guided bone regeneration of the fenestration defect is a reliable treatment procedure.

Gingival pigmentation reduction: a novel therapeutic modality.

AIM: The objective of the present clinical study was to compare the effectiveness of radiofrequency de-epithelialization and conventional (slicing) method in reducing gingival pigmentation on long term basis by split mouth design. MATERIALS AND METHODS: A total of 28 maxillary gingival units from 4 subjects aged between 15-30 years were considered for this clincal study and the selected gingival units were made plaque free and clinically healthy before subjectiing these sites to one of the procedures. The selected sites were abraded by either the conventional (slicing) method (14 gingival units of 21, 22, 23, 24) or by radiofrequency (14 gingival units of 11, 12, 13, 14). After the procedure periodontal dressing was applied to protect the operated area. After 1 week periodontal dressing was removed and the area was irrigated with saline. Follow up examination was done on 30(th), 60(th) and 90(th) days to evaluate the recurrence of pigmentation, if any. RESULTS: It was obsereved that, sites operated with conventional (slicing) method, showed higher mean pigmentation than the sites treated with the radioablation during the follow up period of 90 days. CONCLUSION: When used judiciously, radiofrequency can be clinically valuable, safe and effective method to reduce pigmentation of gingiva.