ABSTRACT
This study was carried out to evaluation the effect of human platelet rich plasma [hPRP] on the bone repair process in rabbit model which could be used in many procedures of orthopedic or maxillofacial bone and implant reconstructive surgery. This study is a prospective experimental study on animal model. A critical size defect [10 mm] was created in the radial diaphysis of 24 rabbit and then supplied with human PRP [treatment group] or the defect left empty [control group]. Radiographs of each forelimb was taken postoperatively on 1st day and at the 2nd, 4th, 6th and 8th weeks post injury to evaluate bone formation, union and remodeling of the defect. The operated radii were removed on 56th postoperative day and were evaluated for biomechanical properties and histopathological criteria. The results indicate that human PRP [as a xenogenic PRP] in treatment group significantly promote bone regeneration in critical size defects compared with control group [p<0.05]. This study showed that hPRP has a high regenerative capacity in critical size bone defects in rabbit model after 8 weeks
ABSTRACT
The effect of corticosteroid therapy on corneal wound healing is controversial. The objective of this study was to evaluate the effects of combination therapy with dexamethasone and acetylcysteine at different times and duration on experimentally-induced corneals wounds and haze in rabbits. Eighteen adult New Zealand white rabbits were divided into three groups of six each. Under anesthesia corneal wounds were created surgically in the center of all eyes. The right eyes of rabbits in group 1 were treated topically with acetylcysteine and dexamethasone immediately after surgery, those in group 2 were treated with acetylcysteine from day 8, and those in group 3 were treated with acetylcysteine from day 1 and with acetylcysteine and dexamethasone from day 1 and with acetylcysteine and dexamethasone from day 15. The left eyes were assigned as controls and were treated with normal saline. All eyes were treated six times a day for 28 days. Corneal wounds were measured by fluorescein staining every day. The combination of acetylcysteine and dexamethasone in group 1 significantly increased mean healing time, but did not change that in groups 2 and 3. Clinical and histopathologic examinations revealed that one month after the ulceration in groups 1 corneal haze was greater in treated than in the control eyes. Moreover, there was no significant difference between the control and treated eyes of group 1, 2, or 3 in terms of corneal haze at two or three months after the ulceration. The findings of the present study show that the association of 3% concentration of NAC and 0.1% concentration of dexamethasone immediately after corneal ulceration can delay corneal wound healing, and consequently produce more corneal haze. Thus, the use of 0.1% concentration of dexamethasone should be delayed at least until the completion of the epithelial defects