ObjectiveTo explore whether FTY-720P could enhance the effect of allograft bone for bone defect repair by suppressing osteoclast formation and function. MethodAnimal experiment:Forty-eight New Zealand white rabbits were selected to establish the tibia defect model (1.5 cm in length) and were divided into 4 groups (n=12) . Defect was not repaired in group A, defect was repaired with allograft bone in group B, with autogenous fibula in group C, and with allograft bone and FTY-720P in group D. Lane-Sandhu scoring system and bone density examination were used to evaluate the effect at 2, 4, 8, and 12 weeks after operation. Cell experiment:Bone marrow-derived mononuclear phagocytes (BMMs) were harvested from 1-month-old Sprague Dawley rats and induced into osteoclasts with macrophage colony stimulating factor (M-CSF) and receptor activator of nuclear factor-κB ligand (RANKL), then were identified with tartrate-resistant acid phosphatas (TRAP). According to different concentrations of FTY-720P before induction, experiment was divided into 0, 500, 600, 700, 800, 900, 1 000, and 1 500 ng/mL groups. The effect of FTY-720P was studied by counting the number of osteoclasts and the number of bone resorption lacunae made by osteoclasts. ResultsAnimal experiment:Lane-Sandhu score showed no significant difference between groups at 2 weeks after operation (P>0.05) , but the score was significantly better in groups C and D than groups A and B, and in group B than group A (P<0.05) . The bone density of group C was significantly greater than that of groups A, B, and D at 2 weeks after operation (P<0.05) , but no significant difference was found among groups A, B, and D (P>0.05) ; the bone density of groups B, C, and D was significantly greater than that of group A at 4, 8, and 12 weeks (P<0.05) , but no significant difference was shown among groups B, C, and D (P>0.05) . Cell experiment:BMMs could be induced into osteoclasts by the addition of M-CSF and RANKL, which could be proved by counting the number of the nuclear and TRAP staining. The osteoclasts were significantly more in 0, 500, 600, 700, 800, 900 ng/mL groups than 1 000 and 1 500 ng/mL groups (P<0.05) , in 0, 500, 600, and 700 ng/mL groups than 800 and 900 ng/mL groups (P<0.05) , in 0, 500, 600 ng/mL groups than 700 ng/mL group (P<0.05) ; and there was no significant difference between the other groups (P>0.05) . The number of bone resorption lacunae in 0, 500, 600, and 700 ng/mL groups was significantly higher than that in 800, 900, 1 000, and 1 500 ng/mL groups (P<0.05) , and it was significantly higher in 0, 500 and 600 ng/mL groups than 700 ng/mL group (P<0.05) , but difference was not significant between the other groups (P>0.05) . ConclusionsFTY-720P combined with allograft bone for bone defect repair can have the same effect to autogenous bone by means of inhibiting osteoclast formation and function, which reduces bone loss.
ObjectiveTo investigate the effects of intermittent irrigation of insulin solution combined with continuous drainage of vacuum sealing drainage (VSD) in chronic diabetic lower limb ulcers. MethodsBetween January 2012 and December 2014, 45 patients with diabetic lower limb ulcer were treated with VSD (group A, n=15), with VSD combining irrigation of normal saline (group B, n=15), and with VSD combining irrigation of insulin solution (group C, n=15) after debridement. There was no significant difference in gender, age, course of ulcers, area and depth of wound, glycosylated hemoglobin, and Wagner grade among 3 groups (P>0.05), and the data were comparable. The levels of fasting blood glucose, 2-hour postprandial blood glucose, and random blood glucose were determined everyday during treatment. The contents of insulin growth factor 1 (IGF-1), tumor growth factor α (TNF-α), and nitric oxide (NO) in necrotic tissue after drainage were determined. The coverage rate and thickness of granulation tissue and clearance rate of bacteria in wound were calculated, the granulation tissue in the center of the wound was harvested for pathological observation with HE staining after 6 days of treatment. The second stage operation was performed according to the condition of wounds, and the time to the second stage operation and the method of the second stage operation were recorded and the survival rate of grafted skin or flap was calculated. ResultsThe pathological staining showed that there were a few new microvessels and fibroblasts in group A after treatment;more new microvessels and fibroblasts were observed in group B;and many new microvessels and fibroblasts were found in group C. There was no significant difference in levels of fasting blood glucose, 2-hour postprandial blood glucose, and random blood glucose among 3 groups during treatment (P>0.05). The coverage rate and thickness of granulation tissue and clearance rate of bacteria in group C were significantly higher than those in groups A and B after treatment (P<0.05). The contents of IGF-1 and NO were significantly increased and TNF-α was significantly decreased in group C when compared with those in group A (P<0.05). Compared with group B, IGF-1 and NO contents were significantly increased at 3-6 days and at 2-6 days respectively, and TNF-α content was significantly decreased at 3-6 days in group C (P<0.05). The method of the second stage operation showed no significant difference among 3 groups (χ2=2.920, P=0.230), but the time to the second stage operation in group C was significantly shorter than that in groups A and B (P<0.05), and the survival rate of grafted skin or flap in group C was significantly higher than that in groups A and B (P<0.05). ConclusionThe treatment of diabetic lower limb ulcers with intermittent irrigation of insulin solution combined with continuous drainage of VSD can reduce inflammatory reaction effectively, promote development of granulation tissue, improve recovery function of tissue, increase the rate and speed of wound healing obviously, but it has no effect on blood glucose levels.