The influence of partial implant-supported restorations on chewing side preference.

This study aimed at determining whether the individual's chewing side preference is affected by local effects, produced by the presence of implant-supported restorations. The test group included 81 patients with partial implant-supported prosthesis. The control group included 108 subjects with no implants. All subjects went through a series of laterality tests for chewing and tasks (hand, foot, eye and ear) side preference. The preferred chewing side (PCS) was determined by observing the first stroke of the chewing cycle during chewing a gum. A positive and significant correlation between the chewing side preference and the subject's sidedness during the different tasks was examined, by performing four Phi correlation tests for: chewing and handedness(r = 0·54; P < 0·001); chewing and footedness (r = 0·49; P < 0·001); chewing and eyedness (r = 0·65; P < 0·001) and chewing and earedness (r = 0·66, P < 0·001). Of the subjects, 78·3% preferred the right side for chewing, 19·1% preferred the left and 2·1% had no clear side preference. There was no statistical difference in chewing side preference distribution between genders. The distribution of chewing side preference was not significantly affected by the location of missing teeth or implants. In conclusion, implant placement will not affect PCS. Therefore, information on chewing side preference should be part of the routine preoperative examination for implant-supported restorations to provide a better treatment plan in those cases that the implant-supported restoration will be on the PCS.

Purification, characterization and anticoagulant activity of a proteolytic enzyme from Vespa orientalis venom.

The anticoagulant effect of Vespa orientalis venom sac extract (VSE) was attributed to a proteolytic process, involving mainly coagulation factors VIII and IX [Joshua, H., Ishay, J., 1975. Toxicon 13, 11-20; Korenberg et al., 1988. Toxicon 26, 1169-1176]. Preliminary purification of the proteolytic activity showed the presence of three separate proteases. One of which, protease I, was purified. The purified enzyme migrated as a double band on sodium dodecyl sulfate polyacrylamide gel electrophoresis (SDS PAGE). The molecular weights of the bands, under reduced conditions were 42 and 44 kD. Both bands retained activity after the electrophoretic run. The enzyme hydrolyses bovine factor IX (BFIX), factor X (BFX) and prothrombin. The pH optimum for the degradation of BFIX was 7.0 and its isoelectric point is above pH 10. The amino acid composition of the protease was determined.