Review the microbiological result of infected total hip replacement cases we found that positive rate of preoperative and intraoperative culture is only 77.1% and 78.5%, and the coincidence rate of preoperative and intraoperative culture results only 59.1%. In all organisms about 56.2% and 46% is staphylococcus of preoperative and intraoperative culture respectively. Staphylococcus can form massive biofilm. The result shows that in total hip replacement infection, the accurate rate of preoperative and intraoperative culture is low and need to improve, and the virulent and resistance organisms maintain a high rate lead to it is hard to cure.

BACKGROUND:Staphylococcal infections and its biofilm formation can occur when orthopedic implants or wound is healing, and are regulated by bacterial population sensing mechanism. RNAIII inhibiting peptide intervenes the quorum-sensing system of staphylococcal and blocks the signal transduction among staphylococcal cells, and inhibits staphylococcal biofilm formation, and then prevents staphylococcal infections.
OBJECTIVE:To investigate the influence of RNAIII inhibiting peptide on the adhesion of staphylococcus epidermis to the Hela cells.
METHODS:The Hela cells were cultured in vitro. There were four groups in this study. In the blank group, saline with dimethyl sulfoxide was added in each wel . In the RNAIII inhibiting peptide group, dimethyl sulfoxide solution containing RNAIII inhibiting peptide was added. In the levofloxacin group, levofloxacin was added. In the combination group, the dose was in accordance with above methods. Using intergroup control method, the adhesion of staphylococcus epidermis to the Hela cells was compared under the effects of saline, RNAIII inhibiting peptide and levofloxacin and their combination.
RESULTS AND CONCLUSION:In the blank group, abundant bacterial adhered to Hela cells. The number of adhered bacteria was significantly lower in each medicine group than in the blank group (P<0.001). The spot count was significantly lower in the levofloxacin group than in the RNAIII inhibiting peptide group (P<0.05). In the combination group, the number of bacteria adhered to Hela cells was decreased (P<0.01). Results verified that RNAIII inhibiting peptide effectively suppressed the adhesion of staphylococcus epidermis to the host cells, and showed synergistic effects on antibiotics.

[Objective]To review our experience in treatine infection after total knee arthroplasty with debridement and component retention to determine To the feasibility,indication,factors related to success and failure,and the main points of technique.[Method]Since 1990 to 2004,9 patients were treated with debridement and component retention at our department.[Result]Four of 9 patients successfully retained their component at most recent follow-up,without ongoing infection(mean 18 months,range 10～25 months).We have not draw the statistically significant factors that related to successful and failure,but the factors such as acute infection,surfacing replacement,immediate debrided after onset of symptoms,and the bacteria sensitive to antibiotic were relate to success.[Conclusion]Debridement and component retention can be used in acute postoperative infection and later acute hematogenous infection after total knee replacement,but timing and indication must be chosen strictly.

BACKGROUND: Staphylococci inhibitor, RNAⅢ inhibiting peptide, has been firstly synthesized in China, while RNAIII inhibiting peptide/bioinspired phosphorylcholine-based cytomembrane coating (RIP/PC) has been also prepared.OBJECTIVE: To evaluate the blood compatibility of RIP/PC.DESIGN, TIME AND SETTING: A randomized controlled animal experiment was performed at Institute of Clinical Pharmacologic Research and Medical Animal Experimental Center of General Hospital of Chinese PLA from October 2005 to October 2007.MATERIALS: A total of 30 healthy adult New Zealand rabbits were provided by Animal Experimental Center of General Hospital of Chinese PLA.METHODS: The 316L stainless steel was dip into a mixture of 5 g/L quaternionic copolymer tetrahydrpfuran and 10% RNAⅢ inhibiting peptide to obtain stable polymer coating, which was extracted at density of 1 cm~2/mL in saline at 37 ℃ for 72 hours to get 100% eluent. The same volume of saline was added to make 50% eluent. The effects of RIP/PC on leukocytes, eryfhrocytes,and blood platelet of rabbits were detected via measuring prothrombin time and activated thrombin time during hemolysis test,hemagglutinatin test, and blood platelet aggregation test.MAIN OUTCOME MEASURES: Hemolytic ratio of erythrocytes, clotting time, prothrombin time, activated thrombin time, amounts of leukocytes, erythrocytes, and blood platelet, as well as blood platelet aggregation.RESULTS: Hemolysis test showed that the hemolytic ratio was 3.08% and 1.88% of 100% and 50% eluent, respectively; both the hemolytic ratios were < 5%, suggesting being coincidence with hemolytic requests of biological materials. The hemagglutinatin test showed that both 100% and 50% eluent did not have any effect on clotting time, prothrombin time, activated thrombin time,amounts of leukocytes, erythrocytes, and blood platelet, as well as blood platelet aggregation.CONCLUSION: The firstly synthesized RIP/PC has a good biocompatibility.

Objective To investigate the effect of hyperurieemia on cardiovascular and cerebrovaseular complications in type 2 diabetes mellitus(T2DM). Methods According to the level of blood uric acid,430 patients with T2DM were divided into hyperuricemia group and non-hyperurieemia group, the differences of uric acid(UA) ,creatine(Cr) ,total cholesterol(TC) ,triglyeride(TG) ,fasting blood glucose(FBG) ,glycosylated hemoglobin(HbA1c) and body mass index(BMI) were compared,and the occurrences of coronary heart disease, hypertension and acute cerebrovascular accidence were observed. Results The FBG and HbAIc were not significantly different between the two groups(P＞0.05). The BMI ,TG,TC and Cr in the hyperurieemia group were significantly higher than those in the non-hyperuricemia group(P＜0.05 ). The incidence rates of coronary heart disease, hypertension and acute cerebrovascular diseases in the hyperuricemia group were also significantly higher than those in the non-hyperuricemia group (P＜0.05 ). Conclusion Hyperuricemia is obviously correlated with obesity and blood lipid abnormalities. Hyperurieemia can aggravate the metabolic disturbances,and can accelerate the occurrence and development of cardiovascular and eerebrovascular diseases in the patients with T2DM.

BACKGROUND: A new material of porous carbonated hydroxyapatite cement (PCHC) is discovered using foaming technique.The new material characterizes original solidification and forms porous structure.OBJECTIVE: To investigate the biomechanical effect of PCHC on repairing cancellous bone defect.METHODS: Among 30 New Land rabbits, 25 ones were considered as surgery group, whose bilateral condyles of femur was used to establish bone defect model (5.5 mm diameter and 12 mm depth). PCHC was implanted into the left side, which was considered as the experimental group, and carbonated hydroxyapatite cement (CHC) was implanted into the right side, which was considered as the control group. Another 5 rabbits were used as normal mechanical control group. Both PCHC and CHC were dip in simulated body fluid (SBF) to test mechanical intension. PCHC and CHC were then implanted into muscles of back in the surgery group. Rabbits Were-sacrificed after 2, 4, 8, 12, and 16 weeks postoperatively. Mechanical analysis was tested following intra-bone and intramuscular implantation, and compressive strength was then tested following dipping into SBF.RESULTS AND CONCLUSION: PCHC: Intra-bone mechanical strength was lower at 2 weeks, the lowest at 4 weeks, but then closed to intension of normal cancellated bone at 8 weeks, higher than normal cancellated bone at 12 weeks, and recovered to the level of normal cancellated bone at 16 weeks. CHC: Intra-bone strength was higher than that of PCHC at 2 weeks, decreased at 4 weeks, gradually increased at 8, 12, and 16 weeks, but still lower than intension of normal cancallated bone. Compressive strength of both PCHC and CHC was not changed following dipping in SBF; however, compressive strength was changed remarkably following intramuscular implantation. The results demonstrated that PCHC characterized by immobilization in situ and mechanical supporting. Thus it could be used for one kind of bone substitute material to repair the bone defect.

OBJECTIVE: To evaluate the histocompatibility of poly (lactic-co-glycolic acid)/RNA Ⅲ inhibiting peptide (PLGNRIP) sustained release microspheres.METHODS: The crude peptide comprising N to C-terminals was synthesized using Fmoc method. The crude synthetic RNAⅢ peptide was purified by reverse phase high performance liquid chromatography, followed by component harvesting according to ultraviolet absorption peak, and freeze-drying. PLGNRIP sustained release microspheres with a diameter of 50-70 pm were prepared using liquid-phase multiple emulsion method. The histocompatibility of PLGNRIP sustained release microscopes were preliminarily evaluated through the use of acute general toxicity test, MTT cytotoxicity test, intramuscular implantation test, sensitivity test, and pyrogen test.RESULTS: Acute general toxicity test results showed that all included animals survived and presented with no toxicosis reaction and obviously changed body mass. MTT cytotoxicity test results revealed that the average relative growth rate of cells from two eluents was over 85%, with cytotoxicity grade 1, which indicated no cytotoxicity. Intramuscular implantation tests showed that at 4 weeks after implantation of RiP powder or PLGNRIP microscopes, no obviously congested, degenerated, or necrotic tissue was observed. All RIP powder and a part PLGNRIP microscopes were degraded. Fibroblasts accounted for a large proportion in all cells. NO inflammatory cell infiltration, involving neutrophits and multinucleated giant celts, was observed. Sensitivity test rasults displayed that the average primary irritation index was 0.38, 0.33, arid 0.31 in the eluent stock solution, 2% dinitoflruorobenzene, and physiological saline-administerd groups, respectively. Pyrogen test results showed that fervescence of each rabbit in the experiment was under 0.5 ℃ and the sum of fervescence was under 1.3 ℃ .This is in coincidence with evaluation criteria of pyrogen test.CONCLUSION: PLGNRIP sustained release microspheras exhibit good histocompatibility.

AIM: RNAⅢ inhibiting peptide (RIP) has been previously proved to possess good histocompatibility and safety for preventing and curing staphylococcal infection, and this study evaluated histocompatibility of polyaiticglycolic acid/RIP (PLGA/RIP) sustained release microsphere. METHODS: The experiment was performed in the Orthopedic Institute, Pharmacologic Research Institute and Animal Experimental Center of General Hospital of Chinese PLA from October 2005 to October 2007.①Preparation of PLGA/RIP: The solid-phase synthesis (Fmoc) method was used to synthesize RIP from C end to N end, then the synthesized peptide was purified by the reverse phase high performance liquid chromatography, and composition was collected by means of ultraviolet absorption peak. The purified RIP was obtained after freezing and drying. Liquid-phase multiple emulsion method was used to synthesize PLGA/RIP microsphere of 50-70 ?m diameter.②Acute general toxicity test was studied in PLGA/RIP. Effect of PLGA/RIP on the cell proliferation was detected with cytotoxicity test by MTT method. Intramuscular implanting test was used to observe the irritation reaction of muscles by implantation materials. Sensitivity test was used to observe the sensitization of PLGA/RIP. Changes of animal's body temperature were determined with pyrogen test. RESULTS: ①Acute general toxicity test: Neither toxicosis reaction nor animal death was found after animals were injected with 100% and 50% eluents of PLGA/RIP peritoneally. Animal's body weight was not changed significantly.②Cytotoxiciity test by MTT method: The average proliferation rate of cell in two kinds of eluents exceeded 85% and cytotoxicity was graded in 1 rank, indicating no cytotoxicity.③Intramuscular implanting test: At 4 weeks after RIP and PLGA/RIP were implanted into the animals, there was not obvious synathresis, denaturation or necrosis in tissues. No inflammatory cell infiltration occurred around the materials. There had been the fibrous capsules around the materials.④Sensitivity test: Average primary irritation index of three groups were 0.38, 0.33 and 0.31 respectively. There was no significant difference among three groups.⑤Pyrogen test: Fervescence of each animal in the experiment was under 0.5 ℃, confirming that the materials had no pyrogenic characteristics. This was in coincidence with evaluation criterion of pyrogen test. CONCLUSION: PLGA/RIP has good histocompatibility and safety, without general toxic reaction, cytotoxicity, immunological rejection, hypersensitive response or pyrogenic characteristics.

OBJECTIVE: To evaluate blood compatibility of polyaiticglycolic acid/RNA Ⅲ inhibiting peptide (PLGA/RIP) delayed release microspheres.METHODS: ① Preparation of PLGA/RIP microspheres: The solid-phase synthesis (Fmoc) method was used to synthesize RIP crude sample from C end to N end; the synthesized crude peptide was purified by the reverse phase high performance liquid chromatography. According to UV absorption peak, the components were collected and freeze-dried, to obtain RIP purifications. Then liquid-phase multiple emulsion method was used to prepare PLGA/RIP microspheres at the diameter of 50-70 μm. ② Preparation of eluent: The PLGA/RIP microsphere powders were eluted with sterile physiological saline at 37 ℃, to prepare 1 g/L eluent; then 0.5 g/L eluent was obtained adding equal volume of sterile physiological saline. The hemolysis test, blood clotting test, and platelet aggregation test were conducted to measure prothrombin time and activated partial thromboplastin time, to observe the influence on rabbit leucocytes, erythrocytes and thrombocytes, and to preliminarily evaluate the blood compatibility of PLGA/RIP microspheres. RESULTS: ①The haemolysis rates of eluent stock solution and 0.5 g/L eluents were 3.24% and 2.67% respectively, which were in coincidence with the criteria of medical biomaterials, less than 5%. ② The eluent stock solution and 0.5 g/L eluents of PLGA/RIP microspheres had no significant effect on rabbit clotting time, prothrombin time and activated partial thromboplastin time, the number of rabbit leucocytes, erythrocytes and thrombocytes, as well as platelet aggregation.CONCLUSION: PLGA/RIP delayed release microspheres have a good blood compatibility.

Objective To investigate the clinical effects of gliclazide sustained-release tablet for recently diag-nosed type 2 diabetes mellitus. Methods 118 subjects with recently diagnosed type 2 diabetes and normal figure were divided into three groups. The three group subjects used gliclazide sustained-release tablet, repaglinide(import-ed) ,novolin 30R for 12 weeks,respectively. For all pretherapy and post-treatment cases, blood glucose and glycosy-lated hemoglobin were tested before meal. After two hours of meal, blood glucose was tested again. Meanwhile, hypo-glycaemia event was inspected. The test results were analyzed by "mean ± standard deviation" method. Results There are no significant difference(P>0.05) in fasting blood sugar and postprandial blood sugar(2h) level between the group using gliclazide sustained-release tablet and the group using novolin 30R. The clinical effects of both gli-clazide sustained-release tablet and novolin 30R to fasting blood sugar are all better than that of repaglinide(import-ed) (P < 0.01). But there are no significant difference in postprandial blood sugar(2h) level between the group of us-ing gliclazide sustained-release tablet and the following two group: repaglinide(imported) and novolin 30R. Conclu-sion The investigation results show that gliclazide sustained-release tablet is better than repaglinide(imported) in fasting blood sugar. But for the effects of postprandial blood sugar(2h), there is no significant difference between gli-clazide sustained-release tablet, repaglinide(imported) and novolin 30R.