It is necessary for the improvement of the medical education and medical system to reform the model of clinical teaching.This article analyzes some problems of today's clinical teaching and clarifies specific demands and aims of teaching,learning and managing in the process of clinical teaching.In order to improve the quality of clinical teaching,the author puts forward some conceives about constructing the "three-in-one" system including teaching,learning and managing in clinical education.

Objective It has been known that cyclooxygenase-2(COX-2) acts as a tumor promoter in rodent models for colorectal cancer, but its precise role in the processes of carcinogenesis remains unclear. The study was designed to observe the relationship between expression of COX and the expression of vascular endothelial growth factor (VEGF) in the mouse embryo fibroblast (MEF) with knock out of COX-1 gene (COX-1 -/- ) or COX-2 gene (COX-2 -/- ) and wild MEF cells (COX-1 +/+ /COX-2 +/+ ). Methods We cultured the mouse embryo fibroblasts, measured the VEGF levels in the culture medium of these cells using ELISA, and extracted mRNA from these cells to identify the expressions of VEGF isoforms by RT-PCR. Results VEGF level could hardly be measured in the COX 2-deficient cells (COX-2 -/- ), however, the VEGF level was significantly increased in the cells with COX-2 gene (COX-2 +/+ ) and decreased by celecoxib, a COX-2 inhibitor. The level of VEGF was not associated with COX-1 expression. COX-2 inhibited the expressions of three isoforms of VEGF at mRNA level. Conclusions COX-2 plays an important role in the VEGF secretion and synthesis and therefore, it has an effect on the angiogenesis and tumor growth.

Objective To observe the protective effect of probiotics VSL # 3 on the rats of trinitrobenzene sulphonic acid (TNBS) induced acute colitis, and the effect on the expression of tight junction proteins claudins (claudinl, 2, and 3) in colon mucosa. Methods Rat of colitis model was induced by TNBS one time enema. Since the second day after the model established, 2ml 0.9％ sodium chloride was intragastric administrated into 8 rats each day (TNBS group), 8 rats with 100 mg VSL # 3 (VSL # 3 group ), another 8 rats with 5-aminosalicylic acid (5-ASA) intragastric administration (5-ASA group), and 0.9％ sodium chloride was intragastric administrated daily into 5 no modeling rats as control group. All were treated for 7 days and then sacrificed. Fecal samples were collected for bacterial culturing and detecting the changes of colon bacteria colonies. Disease activity index (DAI was calculated according to diarrhea, hemafecia and weight. The colon tissue was taken for HE staining and the pathological changes were observed under microscope.The changes of myeloperoxidase (MPO) level in colon tissue were examined by enzyme-linked immunosorbent assay (ELISA). The expression and distribution of claudins 1, 2, and 3 in colon tissue was detected by a novel quantum dots immunofluorescence labeling technique. Results Compared with TNBS group,both VSL # 3 and 5-ASA treatment could improve colitis, as well as decreas DAI and colonic MPO level, and lower the inflammatory score of colitis. Compared with control group, the bacteria counting in the colon of colitis rats changed, the expression of Claudins 1, 2, and 3 expression was significantly increased (average density: 66.200±5.737, 71.780±6.670 and 61.300±5. 199,t＝17.237, 27.909and 21.788, all P＜0.01). Compared with TNBS group or 5-ASA group, VSL# 3 could adjust the balance of intestinal bacteria and increase the expression of Claudin 1 and 3 (Claudin 1 : 75. 550 ±8.717, 66.200±5.737 and 67.080±5.401;t＝9.348, 8. 469; all P＜0.05; Claudin-3: 68. 820±7.443, 61.300±5. 199 and 59. 830±5. 930;t＝7. 519, 8. 988, all P＜0.05), however claudin 2 expression was down-regulated (58. 740±6. 457, 71. 780±6. 670 and 66. 870±5. 791; t＝ 13. 033,P＜0.01, t＝8. 123, P＜0. 05). Conclusion Probiotics VSL# 3 may enhance the intestinal mucosal barrier function through changing the claudins expression, and play a role in the relief of inflammatory reaction in acute colitis.

Objective To investigate the expression and significance of Syndecan-1 and E-Cadherin proteins in human sporadic colorectal carcinoma(SCC). Methods Immunohistochemical SP method was used to determine the expression of Syndecan-1 and E-Cadherin in 52 cases of SCC and 18 normal colorectal tissues. Results The positive expression rates of Syndecan-1 and E-Cadherin proteins were 65.38%,100% and 61.54%, 100% in SCC and normal colorectal tissues, respectively, the difference of which between SCC and normal colorectal tissues was statistically significant(P

Objective To investigate the role of Survivin gene in the pathogenesis of colorectal adenocarcinoma and its correlation with VEGF in tumor metastasis. Methods The expressions of Survivin mRNA and VEGF protein were detected by RT-PCR and immunohistochemical staining, respectively, in 42 colorectal adenocarcinoma samples. Results Survivin mRNA expression was positive in 23 cancer samples(54 8%), while no expression was detected in adjacent normal tissue. The expression of Survivin gene significantly correlated with histological differentiation and Dukes stage, but not with gender or lymph node metastasis. The expression of VEGF significantly correlated with lymph node metastasis. The expressions of Survivin and VEGF were coincident. The colorectal adenocarcinomas which expressed both the Survivin and VEGF were more inclined to occur lymph node metastasis. Conclusions Survivin gene expression significantly correlated with the clinico-pathologic characteristics and biologic behavior in colorectal adenocarcinoma. Detection of Survivin expression may be valuable for diagnosing colorectal adenocarcinoma, and evaluating malignancy extent and prognosis.

Objectives:To evaluate the effect of partial parenteral nutrition(PPN) with fat emulsion on liver function and energy metabolism in patients with liver cirrhosis. Methods:67 cirrhotic patients were divided into two groups randomly and given PPN with(group 1, 33 cases) or without(group 2, 34 cases)fat emulsion for two weeks separately.Their liver function test,fasting blood glucose(FGB) and insulin(Ins) and postprandial blood glucose at 2nd hour (PPBG 2 h),lipid metabolism and arteral ketone body ratio(AKBR) were examined respectively before and after PPN. Results:Having been given PPN for two weeks,ALT and TB levels were decreased in group 1( P 0.05 ). Alb level was decreased in group 2( P 0.05). TG,CH and PL levels were normal in group 1( P 0.05).AKBR was increased in group 1( P

Objective To probe into the association between the polymorphisms of HLA DRB1, DQB1 alleles and esophageal squamous cell carcinomas and then to further examine the features of their immunogenetics. Methods The polymorphisms of HLA DRB1, DQB1 alleles were typed by sequence specific primer based on polymerase chain reaction in 42 patients with esophageal squamous cell cancer and 136 normal control subjects. Results Allele frequency of HLA DRB1 *0901 allele was significantly higher in esophageal cancer patients than that in normal controls ( 0.250 0 vs 0.139 7 , P = 0.028 , odd ratio= 2.053 , etiologic fraction= 0.128 2 ) and so was allele frequency of HLA DQB1 * 0301 ( 0.297 6 vs 0.187 5 , P = 0.046 , odd ratio 1.835 , etiologic fraction 0.135 4 ). There was no association between the rested alleles of HLA DRB1 and DQB1 alleles in the patients. Conclusions Individuals carrying HLA DRB1 * 0901 and/or DQB1 * 0301 may be susceptible to esophageal squamous cell carcinoma, and nucleotide sequences of these two alleles were in accordance with the corresponded allele sequence (exon 2) of genebank.

Objective To investigate the expression of inducible nitric oxide synthase (iNOS) in human gastric carcinoma and its relationship with angiogenesis, lymph nodes metastasi s and clinical staging of gastric carcinoma. Methods The expression of iNOS in 50 patients with gastric carcinoma was studied with im munohistochemical method. Microvessel density (MVD) of human gastric carcinoma was also determined with anti-CD34 as the labelled vascular endothelial cells. Results The rate of expression of iNOS in 50 cases of gastric carcinoma was 70.0% , and MVD averaged 22.0?9.8, higher than those in the tissues around cancer (16 .2%,6.1?3.4) and normal gastric tissues (15.0%,5.5?2.6; P

Objective To analyze the influence of Helicobacter pylori (H.pylori) and smoking on serum pepsinogen (PG) levels in gastric adenocarcinoma (GAC).Methods Serum PGⅠand PGⅡ levels were measured by using radioimmunoassay method;H.pylori infection was determined by Hp-IgG antibodies in stored serum samples by using enzyme-linked immunosorbent assay and 14C urea breath test.Results In H.pylori negative cases,the serum PGⅠmean level in current smoking GACs was significantly increased compared with those non-smoking or ever-smoking GACs (the former:t=2.709,P

Objective To investigate the expression of NOD2 and TLR9 in gastric carcinoma and precancerous lesions and their clinical significance. Methods The expression of NOD2 and TLR9 was measured by immunohistochemical staining (S-P method) in 84 patients with atrophic gastritis, 48 eases with gastric ulcer, 80 cases with gastric adenocarcinoma and 40 eases with superficial gastritis. Results NOD2 and TLR9 expression was up-regnlated in superficial gastritis, atrophic gastritis, gastric ulcer and gastric adenocarcinoma. The positive expression rate of NOD2 was 35% ,21% ,33% ,40% respectively, and the positive expression rate of TLR9 were 15%, 12% ,21% ,22% respectively. The expression of NOD2 and TLR9 in Hp complicated atrophic gastritis, gastric carcinoma was significantly higher than that of lip not complicated disease entities ( P < 0. 05 ). Conclusions The expression of NOD2 and TLR9 may be valuable index for predicting the development of gastric mucosal damage from superficial to atrophic gastritis, gastric ulcer and gastric carcinoma.