Objective To study and prepare a new kind of bone graft, which has osteogenesis, local anti-infective function and low immunogenicity. Methods Gentamicin-impregnated bone was prepared bymeans of ultrasonic and vacuum, the release of gentamicin in vivo was measured by inhibition bacteria. Ten healthy male adult sheep were made animal infection models of thigh bone or humerus defect of 6 mm×6 mm×20 mm at size, and the defect was inoculated into 1 ml 5×1010CFU/ml Staphylococcus aureus. The animals were randomly divided into the experimental group (n=5, the bone graft with gentamicin was implanted) and the control group (n=5, the bone graft without gentamincin). Macroscopic, WBC count, radiological, and histological investigations were carried out to evaluate the antiinfective and osteosis capability. Results The concentrations of gentamicin were 46.1 μg/ml in bone allograft and 17.3 μg/ml in muscles after 1 day. The concentrations of gentamicin exceeding the minimum inhibitory concentration lastedfor 14 days in vivo. WBC in the control group was higher than that in the experimental group. In the control group, 1 case died owing to septemia 3 weeks afteroperation. The implanted bones were wrapped in pus 4 and 6 weeks, and the defects were filled with fibre tissue 8 and 10 weeks after operation. In the experimental group, 1 case was infected, the others had a good concrescence. The bone allografts began to integrate with adjacent bone after 4-8 weeks and integrate well after 12 weeks. The X-ray and histological observation showed that new bone formed and took the place of bone allograft. Conclusion The gentamicinimpregnated bone allograft was of a good sustained release feature in vivo, local antiinfection and osteogenesis. It might be an ideal bone grafting material for bone defects with infection.
Objective To investigate the effect of anti-infective reconstitutedbone xenograft (ARBX) as primary grafting on repair of a segmental contaminateddefect in canine radius. Methods The contaminated segmentaldefects of 1.5 cm were made in both radius of 8 canine and 1 ml of staphylococal suspension was injected into the defect region at a concentration of 5×106 CFU/ml. ARBX(experimental side) or RBX(control side) was implanted into the two sides of the defects respectively as primary grafting followed by internal fixation. The results were compared between the two grafting materials in repairing the contaminated segmental defect. Results In ARBX side, the defects were repaired completely in 5 cases and partially in 1 case, and there existed no osteomyelitis in all cases; while in RBX side, the defects were repaired partially in 1 case and were not repaired in 5 cases after 6 months of operation, and there existed osteomyelitis in all cases. Conclusion Besides its b osteoinductive and osteoconductive activity, ARBX is highly antibacterial and can be used as primary grafting in repairing contaminated segmental defects.
In order to explore retinal toxicity and to estimatequot;safe dosagequot;of intravitreal gentamicin 21 Dutch-belted rabbits divided into 5 dosage groups and 1 control group were investigated.The results showed that, in 3 000mu;g group, optic disc swelling and vein dilating were observed ophthalmoscopieally. Histopathologie study displayed the retinal necrolysis. In 50~500mu;g groups,the retinal pigment change was revealed within 3~14 days after the injection.Histopathologic study displayed that the retinal damages were confined in outer layers of retina in early stage. Inner layers of retina were also influenced in late stage. The results demontrated that with increasing intravitreal gentamiein,retinal damages are gradully aggravated,and even if intravitreal gentamicin was in minimum dose,retinal damages was still observed. （Chin J Ocul Fundus Dis,1994,10:167-169）