BACKGROUND:The form and structure of antigen-extracted xenogeneic cancel ous bone through series of physical and chemical treatment are similar to human tissue. OBJECTIVE:To detect the biocompatibility of antigen-extracted xenogeneic cancel ous bone matrix prepared by three different ways. METHODS:The antigen-extracted xenogeneic cancel ous bone scaffold materials which were prepared through physical, chemical and physical-chemical combined methods and hydroxy apatite biological ceramic materials were implanted into the dorsum subcutaneous tissue. Histological observation was done at 4, 8 and 12 weeks after surgery. The antigen-extracted xenogeneic cancel ous bone scaffold materials which were prepared through physical, chemical and physical-chemical combined methods respectively was used to culture sheep bone marrow mesenchymal stem cells for 7 days. Cel adhesion, growth, proliferation and stroma secretion were observed. RESULTS AND CONCLUSION:At 4 weeks after surgery, a strong inflammatory reaction was detected around materials in four groups. At 12 weeks, the xenogeneic bone materials prepared through physical and physical-chemical combined methods and hydroxy apatite biological ceramic materials internal pore and surrounding tissue inflammation disappeared basical y, with the presence of thimbleful inflammation cells. The material degradation was more than at 8 weeks. The xenogeneic bone materials prepared through chemical methods material internal pore and surrounding tissue inflammation stil existed, suggesting that the xenogeneic bone materials prepared through physical and physical-chemical combined methods exhibited good histocompatibility. A smal amount of orderly osteoblasts existed around hydroxy apatite biological ceramic materials and physical-chemical prepared materials, with a smal amount of bone. These suggested that there was a tendency for ectopic bone formation. The xenogeneic cancel ous bone materials prepared through physical or physical-chemical combined methods have better cytocompatibility. However, scaffold materials prepared through chemical method have poor cytocompatibility and they are not qualified for the safety standards of biological materials.

Objective:To investigate Bcl-2 and Bax gene expression in acute myelogenous Leukemia and the relationship between Bcl-2/Bax ratio and drug resistance.Method:Expression of Bcl-2、Bax was detected by immunohistochemical method while drug resistance of AML was detected by cell culture and MTT assay.Results:A high expression of Bcl-2 and a low expression of Bax were detected in AML,respectively,and the ratio between Bcl-2 and Bax was significantly higher than that in normal control (P＜0.01). The ratio in those who are resistant to chemotherapy was significantly higher than that in those sensitive to chemotherapy (P＜0.05).The responsiveness to chemotherapy of those with a high ratio was poorer than thos with a low ratio (P＜0.05).Conclusion:The alteration of Bcl-2 and Bax played certain role in the development of drug resistance in AML,the test of Bcl-2/Bax ratio may have great significance in choice of chemotherapeutic agents and also provide important information for outcome prediction.

OBJECTIVE To investigate the drug sensitivity situation of Acinetobacter baumannii(ABA) in 3 years to instruct clinical application of the antibiotics.METHODS The drug sensitivity test data of the 428 A.baumannii(ABA) strains from 2006 to 2008 were analyzed retrospectively.RESULTS It was showed from the drug sensitivity test in vitro that the most sensitive drug for A.baumannii(ABA) was imipenem,which resistance rate was 11.3-34%.The resistance rate to amikacin was 29.8-49.5% and to penicillins was is 57.7-91%,the resistance rate to of penicillins drugs was 54-74.5%.The resistance of ABA to ampicillin,cefazolin,cefpodoxime and Cefoxitin was over 91%,and showed the multi-drug resistance features.CONCLUSIONS According to the result of drug sensitive test,the most effective antibiotics are imipenem,meropenem and polymyxin B sulfate.

The conduction of performance appraisal in the hospital is of great significance to the perfection of the appraisal system and the improvement of the managerial efficiency of the hospital. The authors suggest that in the process of establishing an appraisal system of hospital performance, it is necessary to use for reference enterprises' experience in performance appraisal and the theories of performance management. Firstly, single-faceted pursuit of economic benefits should be avoided, the establishment of an external hospital appraisal system and the establishment of an internal hospital appraisal system should be combined, and attention should be paid to the overall application of performance appraisal in performance management. Secondly, in light of their own experience in hospital management, the authors put forward the suggestion of establishing a performance appraisal system of three levels: the hospital , the department and the post. They also argue that attention should be given to the selection of comprehensive appraisal methods, continuous communication about performance, and readjustment in a timely manner.

BACKGROUND: The conical telescopic crown denture has a better long-term effect on dentition defects of few remaining teeth than the traditional removable denture. However, there are few studies to analyze the application of these two kinds of repair methods using the finite element method. OBJECTIVE: To compare the stress distribution of the isolated abutment tooth repaired using the conical telescopic crown denture and traditional removable denture. METHODS: Two-dimensional images of the mandible and dentition in healthy adults were scanned by CT. Three-dimensional finite element models of conical telescopic crown denture and traditional removable denture were established in the mandible only with the bilateral canines. Under the same vertical and oblique loadings, the maximum equivalent stress of the abutment, periodontal membrane or edentulous alveolar ridge was compared between two repair methods. RESULTS AND CONCLUSION: Under the vertical and oblique loadings, the total stress of abutment and periodontal membrane in the traditional removable denture was higher than that in the conical telescopic crown denture and the stress in the corresponding ring was concentrated obviously; the total stress of edentulous alveolar ridge in the conical telescopic crown denture was slightly larger than that in the traditional removable denture, but the stress was wel -distributed and concentrated in a smal area. Under the oblique loading, the total stress of abutment, periodontal membrane and edentulous alveolar ridge was higher than that under the vertical loading in these two dentures, and the stress was concentrated in the periodontal membrane of lingual neck, but the total stress in the traditional removable denture was larger, with a wider concentration range. These findings indicate that the stress on the supporting tissue of conical telescopic crown denture is more evenly distributed within a smal er range than that of traditional removable denture, and the former is more fit for the health of abutment, periodontal tissues and edentulous alveolar ridge.

BACKGROUND: Hydroxyapatite/β-tricalcium phosphate biphasic ceramic bone has good cel compatibility, but its mechanical properties are poor. OBJECTIVE: To construct chitosan/ or calcium alginate/biphasic ceramic bone scaffolds and to detect their mechanical properties and cytocompatibility. METHODS: Different concentrations of chitosan (2%, 4%, 7%, 10%) or calcium alginate (3%, 4%, 5%, 7%) were mixed with biphasic ceramic bone to prepare chitosan/biphasic ceramic bone scaffold and calcium alginate/biphasic ceramic bone scaffold. Their morphology and structure, coagulation time, anti-dissolution properties, shear force, compressive strength and cel compatibility were detected. RESULTS AND CONCLUSION: (1) Coagulation time: with the concentration increase, the initial and final setting time of these two kinds of composite scaffolds were prolonged to some extent. (2) Scanning electron microscopy: these two kinds of composite scaffolds showed porous microstructures with different pore sizes. (3) Anti-dissolution properties: the calcium alginate/biphasic ceramic bone scaffold (3%, 4%, 5%, 7%) and chitosan/biphasic ceramic bone scaffold (7%, 10%) had good anti-dissolution properties in the liquid. (4) Mechanical strength: with the concentration increase, the shear force and compressive strength of the calcium alginate/biphasic ceramic bone scaffold were reduced. (5) Cel compatibility: the cytotoxicity of chitosan/ or calcium alginate/biphasic ceramic bone scaffolds was graded as 0-1 or 2-3, respectively. These results show that the chitosan/biphasic ceramic bone scaffold has better mechanical properties and cel compatibility than the calcium alginate/biphasic ceramic bone scaffold.

Two hundred women with singleton pregnancy at full term undergoing cesarean section with combined spinal-epidural anesthesia were randomly assigned into 2 groups (n=100 in each group). During anesthesia the polyvinyl chloride epidural catheter was used in control group and the wire-reinforced epidural catheter was used in study group.The results showed that the number of patients in whom blood or blood-tinted fluid was withdrawn from epidural catheter was significantly lower in study group than that in control group.The domestic wire-reinforced epidural catheter can reduce the incidence of blood vessel injury induced by insertion of epidural catheter.

BACKGROUND: Due to dentition defect, dentition loss, periodontal disease, trauma and tumor, many patients have to face insufficient buccal-lingual mandibular width. At present, there is no consistent conclusion in suitable peri-implant buccal-lingual mandibular width. OBJECTIVE: To investigate the stress of implant-bone interface with three-dimensional finite element method, in order to evaluate buccal-lingual mandibular width suitable for implants. METHODS: Classes Ⅰ and Ⅲ mandible implant models (the buccal-lingual width of implant neck region was 1, 1.5, 2, 2.5, 3 and 3.5 mm) were loaded with 200 N forces vertical y and at 60° oblique. Then, the stress and strain in the implant-bone interfacial were analyzed. RESULTS AND CONCLUSION: Almost 2 mm or more than 2 mm of mandible bone width could result in good stress distribution in implant-bone interface. The stress distribution of oblique loading was much greater than that of vertical loading. Proper quantity of peri-implant mandibular width is good for stress distribution in implant-bone interface. In the clinical treatment, the oblique loading should be avoided or reduced.

BACKGROUND:Currently, there are many studies on colapsed repair, but a systematic and horizontal comparison is not reported yet. OBJECTIVE: To compare the effect of conventional resin adhesive, resin adhesive+silane coupling agent and adjacent surface open part of the crown on colapsed repair through clinical trial and in vitro experiment. METHODS: (1) Clinical trial: 90 patients with porcelain colapse were randomized into three groups, and respectively treated with conventional resin adhesive, resin adhesive+silane coupling agent and adjacent surface open part of the crown. Success rate was measured and compared among three groups at 1 year after repair. (2) In vitro test: Twenty test specimens were equaly divided into two groups, and treated with conventional resin adhesive and resin adhesive+silane coupling agent, respectively. Then, shear strength was detected in the two groups. Twenty double-crown specimens were equaly divided into four groups. The first three groups were treated with sand blasting, silane coupling agent and their combination treatment, respectively; the rest group had no treatment (control group). After repair, the tensile strength of each specimen was detected.RESULTS AND CONCLUSION:The success rate of colapsed repair was 37% for conventional resin adhesive, 90% for resin adhesive+silane coupling agent and 100% for adjacent surface open part of the crown. The shear strength was (13.978±0.343) MPa for the conventional resin adhesive and (10.058±0.64) MPa for resin adhesive+silane coupling agent, and there was a significant difference between two methods (P < 0.01). The tensile strength was (0.68±0.04) kN in the control group, (1.00±0.02) kN in the sand blasting group, (1.31±0.08) kN in silane coupling agent group, and (1.09±0.04) kN in the combination group, and there was a significant differences between groups (P < 0.01). Experimental results show that the silane coupling agent+resin adhesive treatment and adjacent surface open part of the crown are superior to conventional resin adhesive.

BACKGROUND:There are less reports on how to successfuly build the internal spatial configuration of tissue-engineered tooth scaffolds.
OBJECTIVE:To find a way to establish a series of three-dimensional digital modes for tissue-engineered tooth scaffold, such as CAD spatial configuration and Standard Template Library (STL) files.
METHODS:In order to get three-dimensional printing format of STL files, MICRO CT data of DICOM format were input into MIMICS and GEOMAGIC softwares, creating the outline of STL files. Then CATIA V5R17 software was used to create the three-dimensional digital mode of tissue-engineered tooth. Then, the overal model of the internal scaffold was obtained by arraying at the proper coordinates. Various overal scaffold configurations could be built rapidly by varying monomer configuration. The STL files of CAD model of three-dimensional printing tissue-engineered tooth were obtained by assembling the tooth outline mode and the internal scaffold.
RESULTS AND CONCLUSION: The CAD model was constructed successfuly, and this model could be directly used for three-dimensional printing rapid prototyping system to produce tissue-engineered tooth scaffolds. These findings indicate that the three-dimensional digital mode based on reverse engineering and positive engineering can be established, which can be used to quickly build a variety of internal spatial configurations of scaffold materials required for tissue-engineered teeth.