Based on the basic requirement of medical education criteria,we reform courses by improving the goal,content,form and teaching method,and search for the method of improving the quality of teaching and cultivating.

BACKGROUND: Regeneration of type Ⅱ furcation defects of periodontal tissues is still a great clinical challenge. OBJECTIVE: To compare different densities of autologous bone marrow mesenchymal stem cells (auto-BMSCs) for repairing canine experimental class Ⅱ furcation defects of periodontal tissues. DESIGN: A randomized controlled trial. SETTING: Laboratory in Stomatological Hospital Affiliated to Fujian Medical University and Department of Animal Experiment in Fuzhou General Hospital. MATERIALS: Experiments were performed at the Laboratory in Stomatological Hospital Affiliated to Fujian Medical University and Department of Animal Experiment in Fuzhou General Hospital of Nanjing Military Area Command of Chinese PLA from July 2005 to September 2006. Six 18-month Beagle dogs were provided by Department of Animal Experiment in Fuzhou General Hospital of Nanjing Military Area Command of Chinese PLA. Animal intervention met animal ethical standards. Bio-Gide collagen membrane and BME-10X collagen membrane were used in the study.METHODS: Class Ⅱ furcation defects were induced surgically on the buccal side of canine mandibular second and third premolar (P2, P3) and first molar (M1). The ex vivo expanded auto-BMSCs from six 18-month Beagle dogs were seeded in BME-10X collagen membranes at cell density of 5×108 L-1，5×109 L-1，5×1010 L-1, and delivered into experimental class Ⅱ furcation defects, underneath a Bio-Gide membrane. Bio-Gide membrane alone was used as a control. The percentage of new cementum length and percentage of new alveolar bone area were measured on OLYPUS IX 71 inverted research microscope and OLYSIA BioAutoCell software in a computer.MAIN OUTCOME MEASURES: Each specimen was stained with hematoxylin and eosin. The lengths of new cementum and the area of new alveolar bone were calculated.RESULTS: The percentage of newly formed cementum length and the percentage of newly formed alveolar bone area were (51.5±5.6)% and (27.1±7.7)% in the control group,（84.8±8.9）% and（30.6±7.7）% in the 5×108 L-1 BMSCs group, (91.8±5.2)% and (68.3±11.4)% in the 5×109 L-1 BMSCs group and (88.8±7.2)% and (78.5±12.7)% in the 5×1010 L-1 BMSCs group. There were significant differences when comparing the BMSCs groups to the control group (P < 0.01), but there was no significant difference in each BMSCs group. There were significant differences in the percentage of newly formed alveolar bone when comparing the 5×109 L-1 and 5×1010 L-1 BMSCs groups to 5×108 L-1 BMSCs group and control group (P < 0.05), but there was no significantly difference between the first two groups, and neither was the later.CONCLUSION:Periodontal regeneration can be induced by BMSCs transplantation. The mechanism of regeneration is associated with inoculated density.

BACKGROUND:Previous studies have found that human platelet-derived growth factor-B (PDGF-B)-transfected gingival fibroblasts are capable of rapid proliferationin vitro, which can secrete platelet-derived growth factor BB proteins. OBJECTIVE:To explore the ability of PDGF-B-modified gingival fibroblasts in the acelular dermal matrixin vivo to form periodontal tissue engineering compound. METHODS: Gingival fibroblasts from Beagle dogs transfected with or without PDGF-B gene were implanted into the acelular dermal matrix. Cel growth on the acelular dermal matrix was observed. PDGF-B gene-transfected gingival fibroblasts/acelular dermal matrix composite (experimental group), gingival fibrobalsts/acelular dermal matrix composite (control group) and acelular dermal matrix (blank group) were implanted subcutaneously into the nude mice, respectively. At 2, 4, 8 weeks after implantation, skin tissues were taken and observed histologicaly. RESULTS AND CONCLUSION: PDGF-B gene-modified gingival fibroblasts and non-transfected gingival fibroblasts both grew and proliferated wel in the acelular dermal matrix. At 8 weeks after implantation, in the blank group, the surrounding cels largely entered into the acelular dermal matrix, but produce less new colagen fibers, and the cels only grew on the original colagen scaffold; in the control group, a great amount of colagen fibers formed, the original colagen fibers in the acelular dermal matrix were replaced by newly formed colagens, but the original colagen structure was reserved; in the experimental group, a large scale of permineralization formed, and mineralized nodes were arranged along the original colagen scaffold. These findings indicate that PDGF-B gene modified gingival fibroblasts can acquire osteoplastic abilities in the acelular dermal matrix in vivo.

Objective:To study the correlation of elastase(EA) and ? 1-antitrypsin (? 1-AT) level in gingival crevicular fluid(GCF) of different periodontal status and their roles in periodontal inflammatary pathogenesis. Methods: 62 volunteers aged 45～51 years old were enroled.Their periodental status were examined and grouped into healthy periodontium (H),8 cases,marginal gingivitis (MG),12 cases,mild chronic periodontitis (MCP),20 cases and advanced chronic periodontitis (ACP),22 cases.EA in GCF were measured with a chromogenic low molecular weight substrate reaction and the ? 1-AT with ELISA. Results: Significantly positive correlation was found between GCF-EA activity and clinical periodontal parameters (P

Objective To evaluate the mult iphase hepatic CT scan for detecting the hypervascular hepatocellular carcinoma (HCC) by using multidetector row helical CT (MDCT). Methods Multiphase hepatic CT scan of the liver in 40 patients with HCC was carried out with Marconi 8000 multidetector row helical CT scanner .The early arterial phase scan, late arterial phase scan, and portal venous phase scan were started at 20 s, 34 s, and 80 s after the injection of contrast medium, respectively. The numbers of the detected lesions were calculated in each phase. The density values of the liver and tumor were measured for HCC ≥1 cm, and the density difference values of the liver and tumor in each phase were statistically calculated and analyzed. Results The study showed that a total of 61 lesions was found in 40 cases, and the lesions ≥ 1 cm were 47. The density difference values between hepatic parenchyma and HCC in the 47 lesions were significantly different at the early arterial phase, the late arterial phase, and the portal venous phase ( P

Objective To analyze the variable appearances of hepatic angiomyolipomas on CT and MRI, and to improve the diagnostic accuracy with CT and MRI. Methods All 13 cases were proved by surgical pathology. Helical CT scanning of pre- and post-contrast arterial phase, portal venous phase were performed in 12 cases, delayed phase scanning was performed in 5 of 12 cases. Magnetic resonance imaging with SE T 1WI, FSE T 2WI, and FMPSPGR axial dynamic multi-phase contrast scanning were performed in 7 cases. Results On pre-contrast CT scans, 11 of 12 lesions appeared as hypodensity, the other one appeared as slight hyperdensity. On the arterial phase scans, all lesions were markedly enhanced, the central vascular structure could be seen in 8 lesions. On the portal venous phase, 8 lesions remained enhanced and the central vascular structure could also be seen in 6 lesions. 5 of 7 lesions showed inhomogeneous hypointensity on SE T 1WI, and all of 7 lesions showed hyperintensity (from slight hyperintensity to strong hyperintensity) on FSE T 2WI. 6 lesions showed enhancement on the MR arterial phase scans, the other one showed no marked enhancement because the most parts of the lesion were fat. 4 lesions showed prolonged enhancement on the portal venous phase, and the other 3 lesions showed hypointensity. The central vascular structure could also be seen in 4 of 7 lesions on MR contrast dynamic scanning. Conclusion Both CT and MR could demonstrate the characterization of hepatic angiomyolipomas, especially the central vascular structure in the lesions strongly hint the diagnosis of angiomyolipomas. MR SE sequence with fat suppression is more sensitive than CT in the demonstration of the fat. CT and MR dynamic multi-phase contrast scanning can fully reflect the characterization of hepatic angiomyolipomas and can be helpful to improve the diagnostic accuracy.

Computed tomography (CT) has become a very important method for preoperative examination for hilar cholangiocarcinoma.In this article,the multidetector helical CT findings of 20 patients with hilar cholangiocarcinoma who were confirmed by surgical pathological examination or biopsy in the Ruijin Hospital of Shanghai Jiaotong University from September 2010 to September 2012 were retrospectively analyzed to investigate the value of muhidetector helical CT in the diagnosis and resectability evaluation of hilar cholangiocarcinoma.All the 20 patients received dynamic contrast enhanced CT scanning after abdominal plain scanning,including arterial phase and portal venous phase scanning.Six patients received additional delayed phase scanning for 3-4 minutes.Muhi-phase reconstruction (MPR) and CT angiography were performed after the scanning.The location and sizes of lesious,the range of invasion of adjacent vessels,swelling of lymph nodes of hilar and retroperitoneum,and hepatic metastasis were recorded.The results showed that only 8 lesions were found on CT plain scanning,and they were presented as hypodense nodules.All lesions were showed on contrast enhanced images.Five cases with infiltrating type were showed as focal wall thickness of hilar bile duct,ringlike enhancement appeared on arterial phase scanning,and the enhancement was more apparent in portal venous and delayed phasc scanning.Eight cases with intraductal growing type demonstrated as intraductal nodules,obvious enhancement was detected on delayed phase scanning,and the dilation of intrahepatic bile duct was also found.Seven cases of tumoral type showed as mass located in hilar region and involved adjacent vessels and partial hepatic parenchyma.Diffused or local dilation of bile duct could be seen on CT images.Combination of 2and 3-dimensional reconstruction images can show more clearly of hilar cholangiocarcinoma lesions,invasion of hepatic arery or portal vein,segmental atrophy and metastasis of lymph nodes and liver.One-stop CT examination combined with axial multiphase dynamic contrast enhanced scanning with MPR and CT angiography of multidetector helical CT can clearly show the lesions of hilar cholangiocarcinoma,improve the preoperative tumor staging and help to design the surgical treatment.

Dental Pulp Diseases ; diagnosis ; therapy ; Humans ; Periodontics

Objective To compare the ability of CT and MRI in evaluating the residual of tumor of hepatocellular carcinoma (HCC) and its stability after treated by transcatheter arterial chemoembolization (TACE) with Lipiodol.Methods 28 patients with HCC underwent CT, MRI and angiography within 2～6 months after 1～4 procedure(s) of TACE. These three examinations were completed sequentially within one month. CT and MRI findings were thus compared on the basis of the results of arteriography and clinical follow-up at least 6 months.Results 46 lesions were found in 28 patients. 31 lesions with and the other 15 lesions without residual viable tumor were confirmed by arteriography and clinical follow-up. 20 lesions with and 26 lesions without residual viable tumor were found on CT images, and CT displayed 64.5% sensitivity, 100% specificity, and 76.1% accuracy respectively. 29 lesions with and 17 lesions without residual viable tumor were found on MRI images, and its sensitivity, specificity, and accuracy were 93.5%, 100%, and 95.7% respectively. The sensitivity and accuracy between CT and MRI in evaluating the residual viable tumor of HCCs after TACE were significant different(?

BACKGROUND: The biological functions of platelet-rich plasma (PRP) are affected by multiple factors, such as individual difference, PRP concentration, PRP carder, PRP-activated methods and so on. OBJECTIVE: To evaluate the effect of PRP, activated by different concentrations of thrombin, on the repair of cranial defects. METHODS: Whole blood of the central artery of rabbit ears was extracted to prepare PRP, which was then diluted so that the final platetet count was about 5 times of the whole blood. Four whole-thickness layer of cranial defects at an 8-mm diameter were created in 16 New Zealand rabbits and randomly grafted with β-tdcalcium phosphate (β-TCP) and PRP, activated by 60 U/mL. thrombin; β-TCP and PRP, activated by 1 000 U/mL thrombin; β-TCP and PRP; β-TCP alone. At 1 and 3 months following implantation, X-ray analysis and microscopic observation were performed to onserve cranial repair, the area percent of new bone formation was calculated. RESULTS AND CONCLUSION: At one month post-surgery, the edge of defects was clear in each group, with varying degrees of new bone formation surrounding the defects, β-TCP particles partially degraded and the degradation lesion was replaced by new bone, only a small amount of bone lacunae was seen, fiber wrapped around the defect center β-TCP, only a small number of specimens showed new bone formation; X-ray showed a clear boundary and uniform defect density; the percentage of new bone formation in the PRP groups were higher than β-TCP groups (P < 0.05). However, there was no significant difference between PRP group groups (P > 0.05). At 3 months post-surgery, the defect boundary was unclear in each group, the new bone formation increased, the β-TCP particles surrounding defects partially or all degraded and were replaced by new bones, some regions appeared trabecular bone, bone lacuna in new bone was increased, the central defect of the majority of specimens exhibited new bone formation; X-ray showed defect boundary was unclear in each group, defect surrounding density was higher than the center defect, and bone mineral density was equivalent to other normal parts; the percentage of new bone formation in the PRP groups was significantly higher than that in the β-TCP groups (P < 0.05), PRP +β-TCP group was higher than the other 3 groups (P <0.05), there was no significant difference between two thrombin groups (P > 0.05). It is indicated that although PRP improves the repair of cranial defects, 60 and 1 000 U/mL of thrombin has no effects on PRP rapairing cranial defects in New Zealand white rabbits, compared with PRP+β-TCP group, possible the absence of the optimal concentration of thrombin.