Human plasma fibronectin potentiates the mitogenic activity of platelet-derived growth factor and complements its wound healing effects

Integrin-mediated cell adhesion and growth factor stimuli are both required for optimal control of cell proliferation. In the context of skin injury, cell-derived fibronectin and platelet-derived growth factor play important roles in the stimulation of cell proliferation and migration, activities that are crucial to the healing process. To assess the ability of exogenously supplied plasma-derived fibronectin to stimulate wound repair and to study its ability to cooperate with platelet-derived growth factor-BB during healing, we devised a novel topical delivery formulation that allows the controlled release of both molecules to a wound. Using this topical formulation and the rabbit ear model of dermal wound healing, we show that plasma fibronectin is a potent stimulator of the wound healing process. We also show that administration of fibronectin and platelet-derived growth factor-BB in combination has additive wound healing effects. Finally, we report novel findings on the ability of soluble plasma fibronectin to potentiate the mitogenic effects of platelet-derived growth factor-BB in vitro. These findings not only show that optimal concentrations of exogenous fibronectin administered using an effective delivery system stimulate wound healing; they also suggest that PDGF-BB should be administered with fibronectin to achieve optimal therapeutic stimulation of wound healing.     

IMMUNOLOGICAL FEATURES OF HLA-B27 ANTERIOR UVEITIS

Analysis ol the immunological features of anterior Uveitis (AU) revealed a dichotomy of abnormalities defined in terms of the HLA-B27 status of the patient. HLA-B27-positive AU was characterised by the occurrence of ins autoantibodies and an absolute T cell lymphopenia during active disease which returned to normal with recovery. This phenomenon was not observed in HLA-B27-negative AU or in controls and could not be attributed to antilymphocyte antibodies as these were not detected. Furthermore, there were no changes in T-cell subsets (helper and suppressor T lymphocytes). Compared with HLA-B27-positive AU patients, the HLA-B27-negative group demonstrated elevated lgE levels and increased prevalence of smooth muscle autoantibodies. Key words: anterior Uveitis, HLA-B27, immunological abnormalities, T lymphocytes, autoantibodies.     

Effects of Vibration Training and Detraining on Balance and Muscle Strength in Older Adults

The purpose of this study was to analyze the effects of 2 days/week versus 4 days/week of Whole Body Vibration (WBV) during eight weeks of WBV training on health-related quality of life (SF-36), balance and lower body strength, as well as short-term detraining (3 weeks) on balance and lower body strength among older adults. Thirty-four older adults were randomly assigned to a control group (Control; n = 11) or to one of the vibration training groups: WBV 2 days/week (WBV_2d; n = 11) or WBV 4 days/week (WBV_4d; n = 12). The WBV groups exercised for 8 weeks, following 3 weeks of detraining. Lower body strength increased significantly (p < 0.05) for both groups, WBV_2d and WBV_4d, after 8-week training. A significant reduction in strength was observed following 3 weeks of detraining only in WBV_2d group (p < 0.05). All variables of the SF-36 and the balance test did not change after intervention in any group. 2 days/week and 4 days/week of WBV during 8 weeks showed the same improvements on muscle strength. 3 weeks of detraining did not reverse the gains in strength made during 32 sessions of WBV.

Key points

• 2 days and 4 days per week of WBV training during 8 weeks showed the same improvements on muscle strength.
• 3 weeks of detraining did not reverse the gains in strength made during 32 sessions of WBV exercise.
• 3 weeks of detraining did reverse the gains in strength made during 16 sessions of WBV exercise.

Key words: Whole-body vibrations, posturography, dose-response, equilibrium