0.05). Conclusions The expression of XAF1 decreases in both malignant and benign colo-rectal tumors and is significantly lower in colorectal carcinomas than in adenomas/polyps. Thus, XAF1 may have the potential role in differentiating colorectal cancer from benign tumors.

Objective To evaluate the clinical value of magnifying chromoscopy in combination with Kudo criteria in detection and diagnosis of colorectal lesions. Methods After conventional electronic colonoscopic diagnosis of 125 colorectal lesions, staining and magnifying observation by chromoscopy were made with Kudo criteria, and biopsy specimen and resected samples were sent for pathologic examinations. Results The accuracy of ordinary colonoscopy and magnifying colonoscopy compared with histological diagnosis of inflammatory polyps, tubular adenomas, villous adenomas and colorectal cancer was 95.62%, 80%, 90% and 100% respectively and 100%, 93.75%, 92.86% and 100% respectively. The overall accuracy of two procedures was 85.6% and 95.2% respectively. Conclusions Magnifying chromoscopy is valuable in detection of tiny and slightly elevated colorectal lesion, and has high efficacy in judging the nature of lesions with Kudo criteria.

is able to provide pathologic data and achieve the efficacy equivalent to surgery.

Objective To evaluate the diagnostic yield and accuracy of double balloon enteroscopy and capsule endoscopy in patients with obscure small bowel hemorrhage. Methods Twenty four patients with obscure small bowel hemorrhage were performed double balloon enteroscopy and wireless capsule endoscopy separately. The route of enteroscopy could be underwent either via mouth or via anus. Negative result of initial route was required afterwards for another via mouth or via anus examination. Capsule endoscope produced by GIVEN Imaging Company was used. The results of both methods were analyzed independently and final diagnosis of each case was compared thereafter. Results Totally 21 of 24 (87.5%) patients had positive findings with enterosocpy, while 11 of 24 (45.8%) patients had positive findings with capsule endoscopy. The etiological diagnosis of enteroscopy in all cases was confirmed by surgical exploration and pathological examination with the accuracy of 87.5% , however, the accuracy of capsule endoscopy was only 25% (6 cases). On assessment of procedure tolerance, double balloon enteroscopy under anaesthesia and capsule endoscopy were well tolerated than via mouth or anus route enteroscopy without anaesthesia. There was no severe procedure related complications. Conclusions The entire small intestine could be examined by double balloon enteroscopy with combination of mouth and anus route. Double balloon enteroscopy was superior to capsule endoscopy in etiological diagnosis of obscure small bowel bleeding. Capsule endoscopy had clinical diagnostic value in detection of multiple and long segment small bowel lesions. Double balloon enteroscopy could be served as the first option in diagnosis of obscure small bowel bleeding.

Objective The aim of this study was to describe the FICE application on gastric mucosa characteristics including normal and pathological changes, with or without H.pylori infection, and its corre-lation with histopathoingical evidence. Methods A total of 32 patients with dyspepsia symptoms and 5 healthy controls were enrolled into study. Each one underwent esophngogastreduedenoscopy (EGD) examina-tion with FICE and magnified observation. The whole stomach was examined by 3 steps: including conven-tional endoscopy followed by magnifying and FICE observation of the gastric antrum and body as well as biop-sies. All the patients were asked to take the rapid urease test (RUT) 、13C -urea breath test (13C-UBT) . Gastric antrum and body were both sub-classified into following 3 patterns by FICE observation and high reso-lution magnifying endoscopy. The sensitivity, specificity of each FICE pattern of both gastric antrum and body were analysed for the assessment of H. pylori infection, and the consistency with the results of RUT and 13C-UBT. Furthermore, the histopathologic parameters including inflammation、activity、atrophy and intestinal metaplasia were also assessed, Results FICE patterns of gastric antrum and body of all 5 control subjects were type Ⅰ, corresponded to an H. pylori negative and non-atrephy gastric mueosa. In study group on gastric antrum, 14 cases of FICE type Ⅰ pattern were noted and only 1/14(7. 1%) corresponded to an H. pylori positive gastric mucosa. 13 cases of FICE type Ⅱ pattern were noted and 10/13 (76. 9%) corresponded to an H.pylori positive mucosa and 9/13(69. 2%) were positive for both gastric atrophy. 5 cases of FICE type Ⅲ pattern were noted and 5/5 (100%) corresponded to an H. pylori positive mucosa and 3/5 (60%) were positive for both gastric atrophy and intestinal metaplasia. There was statistical difference in prediction of H. pylori infection between type Ⅰ FICE pattern and type Ⅱ or type Ⅲ pattern on gastric antrum (P <0. 01). In study group on gastric body, 15 cases of FICE type Ⅰ pattern were noted and only 1/14(7. 1%) corre-sponded to an H. pylori positive gastric mucosa. 13 cases of FICE type Ⅱ pattern were noted and 11/13 (84. 6%) corresponded to an H. pylori positive mucosa. 4 cases of FICE type Ⅲ pattern were noted and 4/4 (100%) corresponded to an H.pylori positive mucosa. There was statistical difference in prediction of H. pylori infection between type Ⅰ FICE pattern and type Ⅱ or type Ⅲ pattern on gastric body (P < 0. 01). Conclusion FICE in combination with high resolution magnifying endoscopy is valuable for identifying the normal gastric mucosa, H.pylori infection and its associated gastritis, gastric atrophy as well as intestinal metaplasia.

Objective To investigate the characteristics of growth and angiogenesis of colon cancer xenograft in nude mice with metabolic syndrome induced by high fat diet.Methods Female BALB/C nude mice were fed with high fat diet (45.0％ from fat,HFD group) or common diet (13.8％ from fat,CD group) for 12 weeks (n=15,respectively).Colon cancer cell line SW480 was marked with green fluorescent protein (GFP) and subcutaneous xenograft model was established.The tumor growth was observed by the in vivo imaging system in small animal at the 4th week.By the end of the experiment,serum glucose and lipid level of the two groups were measured,visceral subcutaneous and visceral adipose tissue,liver and xenograft tumor were dissociated and weighted.The differences of proliferating cell nuclear antigen (PCNA) and CD31 expression in the tumors between groups were analyzed.The t-test or x2 test were performed for group comparison.Results Compared with CD group,the body weight,blood serum glucose level,triglyceride and cholesterol level,adipose content of subcutaneous and visceral of the HFD group significantly increased (t=2.91,4.12,4.43,3.92,3.77 and 4.02,all P＜0.05).Averagedaily energy intake of HFD group was significantly higher than that of CD group (t=2.34,P＜0.05).There was no significant difference between the two groups in liver weight (t=1.02,P＞0.05).However,by HE staining lipid vacuoles in the liver tissue was obvious in HFD group.Average bioluminescent index,tumor volume and weight of xenografts of HFD group were remarkably higher than those of CD group (t=8.84,2.48 and 2.86,all P＜0.05).The immunohistochemical staining results indicated that the strong positive rate of PCNA in xenografts of HFD group was 80.00％ and the microvessel density (MVD) was (25.75±0.96)/per high power field,both of which were higher than those of CD group (14.29％ and (13.33±1.53)/per high power field respectively,x2 =12.52,t=13.35,both P＜0.01).Conclusions The colon cancer xenograft in nude mice with metabolic syndrome induced by high fat diet had a high MVD and grew fast.

Objective Survivin is overexpressed in gastric cancer. However it not expressed in normal gastric mucosa. The expression of survivin is tightly related to the prognosis of gastric cancer.By gene reconstruction we generated pcDNA3 survivin mutant(Cys84Ala) plasmid, and observed its effect on the gastric carcinoma cell lines. Methods The survivin mRNA and protein expression levels were determined by reverse transcription polymerase chain reaction(RT PCR) analysis,Western blot and immunohistochemical staining respectively . Flowcytometry and acridine orange staning were employed to detect apoptosis. Results Overexpression of survivin mRNA and protein were detected in the gastric cancer cell lines. Inhibition of survivin by survivin mutant cDNA induced apoptosis,activated caspase 3 activity,cleaved PARP and promoted cytochrome C releasing in gastric cancer cells,and effectively sensitized gastric cancer cells to chemotherapeutic agents. Conclusion Inhibition of survivin may induce apoptosis in gastic cancer and sensitize gastric cancer cells to chemotherapeutic agents.Survivin targeted therapeutic protocol may potentially benefit gastric cancer therapy.

Objective To investigate the possible signal pathway of the apoptosis in gastric cancer cell lines(SGC 7901 and MKN 45)induced by arsenic trioxide. Methods TUNEL method was used to observe the influence of calcium antagonist, inhibitors of protein kinase C (PKC) and protein tyrosine kinase(PTK) on the apoptosis of gastric cancer cells induced by arsenic trioxide. Levels of cAMP, PKC and PTK were detected before and after the treatment with arsenic trioxide. Results Both PKC and PTK inhibitors could induce apoptosis of gastric cancer cell lines, also both of them had a cooperative action with arsenic trioxide in inducing apoptosis of gastric cancer cells, while calcium antagonist had no any effect on the apoptosis of gastric cancer cell lines. PKC and PTK levels decreased but cAMP level increased during the apoptosis of gastric cancer cells induced by arsenic trioxide ( P

Objective:To compare the image quality, radiation dose, and total iodine content of abdominal computed tomography (CT) enhancement scanning of overweight and obese patients with different scanning protocols, and to explore the optimal keV image serial for abdominal CT.Methods:A total of 90 overweight or obese patients [24 kg/m 2 ≤ body mass index (BMI) < 28 kg/m 2 or BMI ≥ 28 kg/m 2] were divied into groups A, B and C, with 30 patients in each group. Group A used Gemstone spectral imaging (GSI) mode and contrast medium with 320 mg I/ml, group B used low tube voltage mode (100 kVp) and contrast medium with 370 mg I/ml, and group C used conventional tube voltage mode (120 kVp) and contrast medium with 370 mg I/ml. Monochromatic energy images at 50-70 keV (5 keV interval) were reconstructed for the arterial and portal vein phases of group A. Radiation dose and total iodine content were recorded and calculated for the 3 groups. The region of interest was placed on the organ, blood vessel, and erector spinae muscle at same level. The CT values and image noise values were measured, and the contrast-to-noise ratio (CNR) was calculated. All images were scored subjectively in double-blinded by two radiologists. One-way analysis of variance or Kruskal-Wallis H test were used to compare The CT values, CNRs, and subjective scores of each subgroup image in group A, group B and group C, and the radiation doses and total iodine contents in 3 groups were compared. The optimal keV value for group A was selected. Results:At 50-60 keV, the CT values and CNRs of arterial and portal vein phases in group A were higher ( P < 0.05) than or similar to those in groups B and C ( P > 0.05), and the subjective scores were lower than those of groups B and C at 50 and 55 keV ( H = 34.47, 41.27, P < 0.05), whereas there was no statistically significant difference at 60 keV ( P > 0.05). At 65 and 70 keV, only the CT value and CNR of the renal cortex in group A at the 65 keV of arterial phase were higher than those in groups B and C ( F = 102.38, 29.47, P < 0.001). The subjective scores were not significantly between groups B and C ( P > 0.05). There were no statistically significant difference between CT values, CNRs, or subjective scores in group B and group C ( P > 0.05). The effective doses in groups A and B were 24.72% and 25.78% lower than those in group C, respectively. Compared to groups B and C, the total iodine content in group A decreased by 12.50% and 13.34%, respectively. Conclusions:GSI model combined with a low-concentration contrast medium in abdominal CT for overweight and obese patients can meet the image quality requirements while reducing patient total iodine content and radiation dose. The optimal keV value of enhanced abdominal CT for double phases was 60 keV.

Assessment is an indispensable and critical activity in the educational process. In the recent decades, with the birth and development of competence-based educational paradigm, the rationale behind assessment is shifting from "assessment of learning" to "assessment for learning". Workplace-based assessment (WPBA), which aims to improve the quality of both learning and teaching through assessment in real workplace circumstances, is a set of assessment tools that conforms to the new concepts of medical education. In this article, with the purpose to promote the application of WPBA and thus enhance the quality of dental education in our country, a thorough discussion is performed regarding the core principles, tools, advantages of WPBA as well as attentions that should be noted when applying WPBA. It is recommended to establish a longitudinal assessment system which employs various WPBA tools and assesses the development of students' competencies through the whole educational process. Such a dynamic assessment system may be helpful to provide all-rounded and competent dental talents who can eventually benefit the society.