Objective It is difficult to treat chronic osteomyel itis due to the formation of the Staphylococcus aureus biofilms. Liposomal gentamicin-impregnated allogeneic cortical bone can inhibit the formation of the Staphylococcus aureusbiofilms. To explore the treatment of chronic osteomyel itis of rabbit by l iposomal gentamicin-impregnated allogeneic cortical bone. Methods The l iposomal gentamicin, l iposomal gentamicin-impregnated allogeneic cortical bone and gentamicinimpregnated allogeneic cortical bone were produced. Then the chronic Staphylococcus aureus osteomyel itis models of rabbit were made in left lower l imbs of 40 6-month-old rabbits and the right lower l imbs were used as controls. After 2 weeks, the observations of gross and X-ray were done. Four rabbits died within 10 days after the models were made and other 36 rabbits were devided into 6 groups: group A (no antibiotics), group B (intravenous injection of gentamicin), group C (intravenous injection of l i posomal gentamicin), group D (implantation of gentamicin-impregnated allogeneic cortical bone), group E (implantation of l i posomal gentamicin-impregnated allogeneic cortical bone), and group F (implantation of allogeneic cortical bone). After 2 weeks of treatment, the bacterial culture, X-ray and HE staining were done. Results The chronic Staphylococcus aureus osteomyel itis model of rabbit was made successfully. The X-ray showed dissolution of bone and periosteal reaction in groups A, B, C, and F, and no obvious dissolution of bone and periosteal reaction in groups D and E. The Norden scores were (2.5 ± 0.3), (2.1 ± 0.2), (1.5 ± 0.3), (1.5 ± 0.2), (0.9 ± 0.3), and (2.7 ± 0.3) points in groups A-F, respectively; showing significant differences between group A and groups B-E (P lt; 0.05), between groups B, E, F and other groups (P lt; 0.05). The results of blood and marrow cultures for Staphylococcus aureus were positive in groups A and F, and negative in other 4 groups; the results of bone marrow culture for Staphylococcus aureus were positive in 6 rabbits of group B, 4 rabbits of group C and 3 rabitts of group D; and the results were negative in group E. HE staining showed: in groups A and F, abscess and dead bone formed, and no new bone formation were observed; in groups B and C, different degrees of neutrophil accumulation was seen; in group D, some neutrophil accumulation occurred, and osteoprogenitor cells and osteoclasts were seen around implanted bone; and in group E, no neutrophil accumulation was observed, a lot of granulation tissues formed, and osteoprogenitor cells and osteoclasts were seen around implanted bone. Conclusion Implantation of l iposomal gentamicin-impregnated allogeneic cortical bone has remarkly better effect in treating chronic osteomyel itis than intravenous injection of l iposomal gentamicin and implantation of gentamicin-impregnated allogeneic cortical bone.
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.
An clinical and pharmacokinetic study for a drug delivery system (DDS) of gentamycin-loaded chitosan bar were carried out with the purpose to evaluate its efficacy and giving further data for its clinical applications. Eighteen cases of chronic osteomyelitis were treated by surgical necrectomy with implantation of gentamycin-load chitosan bar in the prepared bone cavity. After operation, the concentration of gentamycin in serum and wound drainage fluid were examined at different times and blood urea nitrogen (BUN) and serum creatinine (Cr) as well. The clinical results were evaluated by the conditions of wound healing and clinical and roentgenographic manifestations. The results showed that the serum gentamycin concentration reached its peak level (0.86 microgram/ml) at 24 hours after operation and lasted for 4 days. No increase in the concentrations of BUN and Cr were observed after implantation. The gentamycin concentration in wound drainage fluid was several hundred times higher than the minimum inhibitory concentration (MIC) for staphylococcus aureus. All of the 18 cases were followed up for 24.8 months (in an range of 6-34 months) 16 patients received initial cure and without any recurrence. So, it could be concluded that the gentamycin-loaded chitosan DDS was a simple and effective method for the treatment of chronic osteomylitis without the necessity to carry out a second operation to remove the drug carrier, and it was sound to popularize its clinical application.
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）
In order to explore the histochemical changes in retina after intravitreal injection of gentamycin,a histochemical quantitative analysis of cytochrome oxidase(CYO)and acetylcholinesterase(ACHE)was performed with a computerized image analysis system and was compared with that of morphological study.The results showed that CYO decreased significantly in 100mu;g dosage group.With increasing intravitreal gentamycin dosage or observed days,CYO decreased gradually in all rabbits.In 100~500mu;g dosage groups,ACHE changed mildly at 3 days of injection.It decreased significantly at 7 days.However,it was destroyed completely in 1000~3000mu;g dosage groups at 3 days. （Chin J Ocul Fundus Dis,1994,10:232-235）
【摘要】目的 比较复方中药金喉健和庆大霉素超声雾化吸入治疗急性咽炎的疗效。方法 2003年3月2006年5月急性咽炎患者200例,分为金喉健组100例和庆大霉素组100例,分别用金喉健和庆大霉素注射液配合地塞米松注射液进行超声雾化吸入治疗,1次/d,连续治疗7 d。治疗前后进行临床和实验室检查,观察疗效和安全性。结果金喉健和庆大霉素超声雾化吸入治疗急性咽炎的疗效无差异。结论金喉健雾化吸入治疗急性咽炎疗效显著,无毒副作用。
Objective To extend its application in the field of bone repair by adding oxygen-carboxymethylated chitosan (O-CMC) and gentamicin for modification of the calcium sulfate cement (CSC). Methods The O-CMC/CSC was prepared by adding O-CMC with different concentrations (0.1wt%, 0.3wt%, 0.5wt%, 0.7wt%, and 1.0wt%) in the CSC liquid phase. The effect of O-CMC on the CSC was evaluated by testing the injectability, compressive strength, degradation rate, pH value, cytotoxicity and osteogenesis. After the optimal concentration of O-CMC was determined, gentamicin with different concentrations (0.5wt%, 1.5wt%, and 2.5wt%) was added in the O-CMC/CSC, and then the compressive strength and antibacterial properties were investigated. Results After adding O-CMC in the CSC liquid phase, the injection time of O-CMC/CSC was increased to more than 5 minutes; it significantly prolonged with increased concentration of O-CMC (P<0.05). The compressive strength of the modified bone cement was in the range of 11-18 MPa and it was the highest when the concentration of O-CMC was 0.5wt% (P<0.05). The degradation rate of O-CMC/CSC was not influenced obviously by O-CMC (P>0.05). The pH value was in the range of 7.2-7.4 and Ca2+ concentration was in the range of 6-8 mmol/L.In vitro mineralization experiment indicated that the induced mineralization ability of O-CMC/CSC was much higher than that of pure CSC. The 0.5wt% O-CMC/CSC had the best performance; the compressive strength of the composite bone cement was above 5 MPa after gentamicin was added, which had antibacterial effect. Conclusion O-CMC is able to effectively improve the injection, compressive strength, and osteogenic activity of CSC; in addition, antibacterial properties is obtained in the CSC after adding gentamicin.