ABSTRACT
Objective@#Aerobic exercise may be associated with changes in brain activity within the default mode network (DMN) and dorsal attention network (DAN). We hypothesized that changes in functional connectivity (FC) within the DMN and DAN might be most effectively activated by moderate-intensity exercise. @*Methods@#Resting-state functional magnetic resonance imaging scans and visuospatial attention tests after resting were performed before and after each of moderate- and high-intensity aerobic exercises (10 min each) in 15 healthy male volunteers. @*Results@#The reaction time during the attention test increased significantly, and the rate of correct responses decreased from moderate-intensity exercise condition to high-intensity exercise condition. FC within the DMN under high-intensity exercise condition was higher than that under pre-exercise and moderate-intensity exercise conditions. FC within the DAN under moderate-intensity exercise condition was the highest, whereas FC between the DMN and DAN under moderate-intensity exercise condition was the lowest. Changes in cognitive domain functions were associated with changes in FC between the DMN and DAN. @*Conclusion@#Our results support the inverted-U hypothesis of maximum arousal efficacy during moderate exercise. Both cognitive domains, namely, the attention system and brain activity domains, may be better under moderate-intensity exercise than under high-intensity exercise.
ABSTRACT
Several effective treatment methods and materials have been developed for the treatment of furcation involvement. Currently, the combination of guided tissue regeneration (GTR) and bone grafts is the most commonly prescribed method of treating furcation involved defects. But because these cases often present with poor accessibility, placement of the membrane may be difficult and consequently, clinically impractical. In this study, the alveolar bone healing patterns of adult beagle dogs presenting with alveolar bone destruction treated by one of two methods - treatment using solely bone aIlografts (BBP(R)), or treatment using bone allografts (BBP(R)) stabilized by a fibrin adhesive - were comp ared. The effects of the fibrin adhesive on the initial stabilization of the newly formed bone, subsequent regeneration of bone, and the feasibility of the clinical application of the fibrin adhesive were analyzed. The results of the study were as follows: 1. Clinical signs of inflammation at the 4-8 week interval were not observed: but signs of mild inflammation were histologically observed at the 4-week interval. 2. Allografts stabilized by fibrin adhesive showed good bone formation, whereas defects treated with only the allograft material showed incomplete alveolar bone regeneration. 3. Allografts stabilized by fibrin adhesive showed a decrease in the amount old bone with a concurrent increase in the formation of new lamellar bone four weeks post-op, whereas defects treated with only the allograft material showed no new lamellar bone formation at the same interval. 4. In detects treated with only the allograft material, the defective area was filled with connective tissue 8- weeks post-op, whereas fibrin adhesive stabilized allografts showed viable connections between the original bone and the newly formed bone, in addition to neovascularization 8-weeks post-op. The results of this study show that concurrent use of fibrin adhesive materials can stabilize the allograft material and aid in new bone formation Although the stability of fibrin adhesives fall short of the results achievable by GTR membranes, in cases presenting with poor accessibility that contraindicate the use of membranes, fibrin adhesive materials provide a viable and effective alternative to graft stabilization and new bone formation.