BACKGROUND:Except for mechanical properties and physical and chemical properties, corrosion resistance testing is necessary for a variety of biomedical materials applied in the oral environment to ensure the biocompatibility of materials. OBJECTIVE:To explore the corrosion resistance of titanium abutment and different titanium aloysin vitro. METHODS:Corrosion environment byin vitroartificial saliva was constructed with pH=6.0 at (37±0.5)℃. Potentiodynamic polarization technique, scanning electron microscope and X-ray diffraction methods were employed to assess the corrosion resistance of titanium aloy, gold aloy, nickel-chromium aloy, and titanium abutment immersed in the artificial saliva for 24 hours. RESULTS AND CONCLUSION:Different aloys had different steady-state potentials, and the range of passivation region was the largest for gold aloy, folowed by titanium abutments and titanium aloys, and the smalest for nickel-chromium aloy. After 24 hours of immersion in the artificial saliva, passivation films appeared on the surface of different materials. under the scanning electron microscope, the nickel-chromium aloy surface showed obvious traces of corrosion and there were a large number of large-diameter deep pits, but no corrosion occurred on the surface of the remaining three kinds of aloys; on the surface of nickel-chromium aloy, the contents of chromium, molybdenum and aluminum were decreased, and the contents of nickel and oxygen were increased, but there were stil no changes on the surface of the remaining aloys. Cr2O3 was found on the surfaceof nickel-chromium aloy, TiO2 was generated on the surface of titanium abutment and titanium aloy, but Au and Pt stil existed in a single phase on the surface of gold aloy. These findings indicate that titanium aloy and titanium abutment have similar corrosion resistance that is inferior to the gold aloy, but better than the nickel-chromium aloy.

Objective To investigate the changes of gene expression in the cardiac outflow tract (OFT) in Cx43 knockout (Cx43-/-) mouse embryos, and to elucidate the genes involved in the myocardialization of proximal cardiae outflow tract septum. Methods The cDNA was retrotranscripted from RNA, which extracted from OFT tissues of both Cx43-/- and Cx43 wild type (Cx43+/+) mouse embryos on embryonic day (ED) 14.5. The biotin-labeled cRNA derived from the transcription of cDNA was fragmented as probes. The probes were hybridized with Affymetrix Mouse Genome 430 2.0 Array. Gene Array Scanner was used to screen the signals of hybridization, and the expression of genes was detected. Results Among the differentially expressed genes, there were 143 upregulated and 235 downregulated in Cx43 knockout OFT tissue compared with those in Cx43+/+ heart. Functions of proteins encoded by the altered genes encompassed all functional categories, with the largest percentage in genes involved in signaling pathways such as regulation of transcription, cell cycle, etc. Among the differentially expressed genes in the Cx43-/- heart, some were related with TGFβ/BMP signaling pathway, and Ssr1, Ptk2 and Bmp6 were related with conotruncal defects. These genes were verified by Real-time PCR, and the result was consistent with that of microarray (P<0.05).Conclusions Scaned by Gene Array and verified by Real-time PCR, genes related with TGFβ/BMP signaling pathway, and Ssr1, Ptk2 and Bmp6 were differentially expressed in ED 14.5 Cx43-/- OFT tissue, which may be involved in the myocardialization of proximal cardiac outflow tract septum.

Objective To analyze the features of dynamic contrast-enhanced CT of blunt hepatic injury in rabbits. Methods The model of blunt hepatic injury was established in 40 New Zealand white rabbits with a steel ball falling down to the xiphoid process of the animals. Plain CT scan and dynamic contrast-enhanced CT scan (Hispeed spiral CT/2i, GE, America) of the liver were performed. Arterial,portal and balanced phases were respectively at 8-10 s, 35-40 s and 120-150 s after initiation of the contrast medium injection. The non-enhanced and enhanced images were compared in aspects of location and range of injury, tear of the liver capsule, active bleeding, involvement of the main hepatic veins and CT features of abdominal hemorrhage, which was further compared with the results of gross anatomy. Results The rate of plain CT scan was obviously lower than that of dynamic contrast-enhanced CT scan,which defined single tear in 13 patients, multiple lacerations in 18, liver subcapsular hematoma in seven,liver hematoma in nine, liver coated gap in 17, active bleeding in nine and main hepatic vein injury in five, with coincidence rates with the results of gross observation for 13/13,18/18,7/9,9/9,25/30,9/5and 5/4 respectively. According to Moore' s classification, CT/Laparotomy performed from grade Ⅰ to grade Ⅵ were 5/4 patients at grade Ⅰ , 15/13 at grade Ⅱ, 9/11 at grade, 5/6 at grade Ⅳ, 1/2 at grade Ⅴ, O at grade respectively. Conclusion Dynamic contrast-enhanced CT scan, especially at portal and balanced phases, is of great value for diagnoses of liver injuries and determination of injury severity.

The report introduces a microcomputer controlled instrument which can be used to identify and diagnose acute cerebral apoplexy.The methods of statistics and probability theory are adopted by the instrument to select “body omen” and compute “value”.Z80A is used as the central processing unit and the external device is processed as an internal storage by using linear encodige.The instrurrent uses ZSOA assembly language to make software.

Purpose To investigate the clinicopathologic features, diagnosis and differential diagnosis of primary gastric inflammatory myofibroblastic tumor ( IMT) . Methods Four cases of gastric IMTs were studied by clinicopathologic analysis, immunohistochemistry and in situ hybridization, and the related literature was reviewed. Results In four cases there are two males and two females, age range from 21 to 51 years old, and tumor size ranged from 1. 5 to 6. 5 cm in the greatest dimension. Histologically, these tumors were composed of varied spindle cells and chronic inflammatory cells, in a myxoid or hyalinized stroma. Occasionally, there were calcifica-tion and ossification areas. Most of the spindle cells had bland appearance and a minority of the tumor cells showed mild atypia. One to two mitotic figures were recognized in 10 high power fields ( HPFs) in 1 to 2 patients. Smooth muscle actin staining was observed in all tumors and ALK staining observed in two tumors. One tumor focally expressed CD34. S-100, desmin, CD68, CD117 and DOG1 was negative in all IMTs. The patients were followed up from 24 to 66 months, and none of them had tumor relapsed or metastasis. Conclu-sions Primary gastric IMTs have an intermediate behavior, and a few cases have malignant potential. It should be distinguished from other spindle cell lesions similar to IMT.

Objective To explore the classification of ultrasound images of hepatic parenchyma of schistosomiasis japonica. Methods A total of 2 918 hepatic photographs were selected and classified . All the photographs came from the former research project, which had B ultrasonography examination for residents from three medium endemic villages adjacent to the Dongting Lake,such as Huarong, Hanshou, Lixian, and for advanced schistosomiasis patients in Xiangyue hospital. Results For these hepatic parenchyma images there were five types, including normal echogenic dots (91 photographs), widened echogenic dots (1 757 photographs), echogenic paths(121 photographs), e-chogenic strips (467 photographs) and echogenic bands (482 photographs), etc. , and eight patterns, including nomal echogenic dots (91 photographs), widened echogenic dots (1 757 photographs), echogenic slices (59 photographs), echogenic patches (62 photographs), fine strips (323 photographs), coarse strips (144 photographs), narrow reticular(280 photographs) and wide reticular (202 photographs). Conclusion B ultrasonic images of the liver of schistosomiasis japonica can be classified into five types and eight patterns.

Objective To explore the value of interphase fluorescence in situ hybridization(FISH) in the detection of trisomy 8 in patients with hematologic disorders. Methods Seventy-seven patients were vestigated by directly labeled centrome DNA probes specific for 8 chromosome. The results were compared with that of conventional cytogenetic (CC) analysis. Results The proportion of trisomy 8 of 77 cases of hematologic disorders detected by FISH is higher than by G-banding karyotyping and FISH could offer the result when conventional cytogenetic methods failed to diagnose. Conclusion Interphase FISH is more sensitive in the detection of trisomy 8 than CC, and FISH displays its superiority in the detection of small clone.

Objective To explore the clinical outcomes of the percutaneous radiofrequency nucleoplasty in the treatment of cervical disc herniation.Methods 183 patients with cervical disc herniation were treated with percutaneous radiofrequency nucleoplasty.A retrospective analysis of 183 patients was made,and their effects were evaluated using the VAS and the subjective satisfactory degree of the patients.Results All cases were followed up for 3 to 36 months( average 12 months).There were no complications observed such as hemorrhages,infections and nerve root injurys due to the procedure.One week after operation,symptom remission rate was 58.4％ and perfect rate of subjective satisfaction was 95.1％.At final follow up,symptom remission' rate was 66.1％ and perfect rate of subjective satisfaction was 85.8％.Conclusion Percutaneous radiofrequency nucleoplasty was an effective,minimally invasive and safe procedure to treat cervical disc herniation,and the operative treatment had shown better results.

Objective To investigate the surgical techniques and curative effect for the treatment of tibial plmeau fracture. Methods Totally 107 cases( male 62 cases;female 45 cases) of tibia plateau fractures were operated with internal fixation from January 2000 to December 2006 in our hospital. According to Schatzker classification,there were type Ⅰ fracture 2 cases,type Ⅱ 37 cases,type Ⅲ 29 cases,type Ⅳ 22 cases,type Ⅴ 10 cases,type Ⅵ 7 csses. Type Ⅰ fractures were treated with cannulated screws,other type fractures were treated by open reduction,internal fixation with buttress plates,and bone graft if bone defect existed. The therapeutic characteristics and the functions of the knee were evaluated. Results 107 cases cases were followed-up for 15 ～96 months,mean 28. 8 months.All fractures were healed without any complications. The knee Merchant scores were excellent in 62 cases, good in 24 cases,common in 17 cases,bad in 4 cases. The rate of fineness was 80. 37%. Conclusion Surgical operation is effective methods of treating tibia plateau fracture.

Objective To study the changes of pressure in cervical disc after percutaneous radiofrequency nucleoplasty,and provide theoretical basis for percutaneous radiofrequency nucleoplasty in the treatment of cervical disc herniation. Methods Forty-two patients with cervical disc herniation (33 cases of nerve root-type cervical spondylopathy and 9 cases of vertebral artery-type cervical spondylopathy) were treated with pereutaneous radiofrequeney nucleoplasty. The pressures of operated cervical disc were measured in the operation, and their clinical effects were evaluated using the JOA values 1 week after operation. The relationship between pressure changes in cervical disc and clinical effect was studied. Results The pressure in the cervical disc in 33 cases of nerve root-type cervical spondylopathy was decreased (1.84 ± 0.96) kPa (P=0.000), and the JOA values increased (3.27 ± 1.35) scares (P=0.000) 1 week after operation. The pressure in the cervical disc in 9 cases of vertebral artery-type cervical spondylopathy was decreased (1.72 ± 0.92) kPa (P= 0.000), and the JOA values increased (2.78 ± 0.67) scores (P= 0.000) 1 week after operation. Correlative analysis showed that there was a positive correlation between the pressure decrease of cervical disc and the JOA values increase (P < 0.05). Conclusion Percutaneous radiofrequency nucleoplasty can help to reduce pressure in the cervical disc and relieve the clinical symptoms.