Colorectal cancer (CRC) is one of the most common digestive system neoplasms in China. Recently, the morbidity and mortality rates of CRC continue to increase with the improvement of people's living standard and the change of the dietary structure. It was accepted that the etiology of colorectal cancer is a multi-factor and multi-step process. However, the mechanism of CRC is still unclear. MicroRNAs (miRNAs) are a class of -21 nucleotide non-coding RNAs and function as a negative regulator of gene expression after transcription, participating in tumor angiogenesis, tumor cell proliferation and invasion. MicroRNA-21 (miR-21), as an important oncogenic RNA, plays a vital role in the development and progression of CRC. This review summarizes the advances in research on miR-21 in colorectal cancer.

Objective:To investigate the present situation of medical students′medical ethics education and fur-ther to put forward countermeasures for medical colleges and universities. Method:With the methods of question-naire, literature and interview, medical students of the second grade and above in Xi′an Jiaotong University, Xin-jiang University and Xinjiang Medical University were investigated. SPSS 20. 0 was used to establish a database and frequency analysis method was used to analyze data. Results:It is suggested that some medical students′ motiva-tion to be a doctor is pure and the professional ethical identity is correct. There exist problems in the evaluation of ethics anomie behaviors. The students lack of cognition of medical ethics but pay more attention to medical technol-ogy. Most of the medical students think that clinical practice education and the model demonstration of teachers are conducive to medical ethics education. Conclusion: Universities can develop their own medical ethics education mode through various forms of classroom education, the involvement of old professors in teaching, strengthening learning of medical laws, daily ideological education by counselors and the construction of campus spiritual civiliza-tion.

Objectives To establish a reliable method for isolating and purifying soluble collagen type Ⅱ(SCⅡ)by optimizing preparative procedure.Method The chicken sternal cartilage was selected as raw material.Guanidine hydrochloride was used to remove the proteoglycans.The digestion manners of pepsin,sodium chloride concentrations for salting,types of DEAE anion resin were studied for extracting SCⅡ.The SCⅡ identification was made by SDS-PAGE,absorption spectrum and amino acid analysis.Result It was convenient for pre-treatments of chicken sternal cartilage.The proteoglycans could be efficiently removed by 4 mol/L guanidine hydrochloride.The satisfied results were obtained by limited enzyme digestion of pepsin added by two steps.The optimizing concentration of sodium chloride for salting was 2.4mol/L.SDS-PAGE maps revealed that the bands of purified SCⅡand standard CⅡ were at the same location.The absorption peak of SCⅡ was at 230nm.The concentrations of Gly,Pro and Ala were the highest in 15 amino acids.Conclusion The improved method has significant advantages of simple working process,result reliability and convenient source of raw material.It is suitable for purifying the SCⅡ at variable scales in research works and clinic application.The SCⅡ product obtained has high purity and accords with the characteristics of collagen type Ⅱ.

Objective To prepare the solid dispersion of ginsenoside Rg3 with different carriers and measure their solubility and dissolution characterisitics. Methods The solid dispersion of ginsenoside Rg3 was prepared by the melted and dissolved methods with Poloxamer 188(F68), PVP k29/32, and PEG 6000 as carriers, respectively. The equilibrium solubility and dissolution characteristics of the solid dispersion in vitro were measured by HPLC. The existing state of ginsenoside Rg3 in the solid dispersion was identified by the differential scanning calorimetery. Results The ginsenoside Rg3 was completely dispersed in carrier and formed a mixture with carriers. The solubility and dissolution rates of all solid dispersion were increased obviously. Conclusion The solid dispersion of ginsenoside Rg3 with Poloxamer 188 as carriers is better on improving dissolution and solubility than those with PVP and PEG 6000 as carriers.

Objective To investigate the effect of running exercise on cartilage in rats with an unstable knee joint.Methods Twenty 8-week-old Sprague-Dawley rats had their left anterior cruciate ligament cut to model an unstable knee.They were randomly divided into a control group and an experimental group,10 rats in each group.The control group was given no intervention,while the experimental group accepted running exercise training on na animal treadmill at a velocity of 15 m/min for an hour every day.After 3 and 6 weeks of training,5 rats were sacrificed and cartilage from the medial condyle of the femur was sampled,decalcificated,embedded and sliced on the sagittal plane.After hematoxylin-eosin staining,toluidine blue staining and immunohistochemical staining,the cartilage thickness,Mankin' score,the content of matrix collagen and the proteoglycan content of the cartilage matrix were assessed,and the shape and structure of the unstable knee joints were observed under a transmission electron microscope.Results The cartilage thicknesses and Mankin's scores at 6 weeks were significantly different from those at 3 weeks in both groups.In the experimental group the average thickness of cartilage was 154 ± 13 μm at 3 weeks and 131 ± 15 μm at 6 weeks.The corresponding Mankin's scores were 9.93 ± 1.36 and 11.23 ± 1.57,respectively.Both were significantly different from the control group averages at the same time points.There was also a significant difference in the positive rate of toluidine blue and collagen type Ⅱ staining between the experimental group and the control group at both time points,and in the experimental group between 3 and 6 weeks of training.After 3 weeks of training,fewer chondrocytes were observed under the transmission electron microscope in the experimental group,and fissures were seen on the surface of the cartilages.However,3 weeks later,quite a few ruptures and a lot of necrotic cells could be seen.Conclusions Running exercise can damage the cartilage of unstable knee joints and speed up the development of osteoarthritis.Even moderate exercise could aggravate damage to unstable joints and the cartilage matrix,and accelerate chondrocyte degeneration.

Objective: To study the changes of andrographolides in the drying process of the extract of Andrographis paniculata Nees. Methods: HPLC method was applied to analyze andrographolide and 14 deoxy 11, 12 didehydroandrographolide in the process. Results: The content of andrographolide descended rapidly in the whole drying process, while the content of 14 deoxy 11, 12 didehydroandrographolide ascended at first 12 hours, declined in content was slowly to follow. Conclusion: Baking temperature is not the only main factor to stimulate the transformation of andrographolide and 14 deoxy 11, 12 didehydroandrographolide.

The evolution of hepatocellular carcinoma (HCC) is a compound process which involves many kinds of genes and transductional pathways. The expression of the peptidyl-proplyl-isomerase PIN1 gene, the mutation in exon 3 of beta-catenin and its correspondent abnormal expression and their roles in the hepatocellular carcinogeneisis were investigated. Among 29 pair cases of HCC and non-carcinoma tissues, the expression of PIN1 gene was detected by immunochemical staining. Mutations in exon 3 of beta-catenin gene and differential expression of beta-catenin gene were investigated by the methods of PCR-SSCP, direct sequencing and immunohistochemical technique as well. The results indicated: (1) 44.8% (13/29) cases of HCC presented higher level of PIN1 gene expression than non-cancerous tissues (chi2=32.63, P<0.05), especially in cytoplasm and nucleus, while there was lower level of PIN1 expression in non-cancerous tissues; (2) 58.6% (17/29) HCC tissues showed beta-catenin protein accumulation in cytoplasm and nucleus. 46.2% (6/13) HCC tissues indicated beta-catenin protein accumulation with higher level of PIN1 expression, while 53.8% (7/13) HCC tissues indicated beta-catenin protein accumulation with lower level or trace of PIN1 expression (chi2=0.00, P>0.05); (3) 24.1% (7/29) of primary tumor lesions carried gene mutations in exon 3 of beta-catenin, and accompanied by beta-catenin protein accumulation. There was no mutation in non-cancerous tissues. All the mutation presented in tissues with low level of PIN1 expression. There was no mutation of beta-catenin gene in tissues with high PIN1 expression level (chi2=58.12, P<0.05). So it was postulated that the increase of PIN1 gene expression could promote hepatocellular carcinogenesis via a way different from beta-catenin gene mutation.

ObjectiveTo investigate the influence of cobalt chloride ( CoCl2 )-mimetic hypoxia on theproliferation,apoptosis and migration of human pancreatic cancer cell fine PANC1.MethodsPANC1 cells were treated with 0(control),100,200,400,800 μmol/L CoCl2 respectively for 24 h.Real-time RT-PCR and Western blot were used to determine hypoxia induced factor ( HIF)-1o mRNA and protein expression respectively,and cell counting kit-8(CCK-8) assays,flow cytometry and cell scratch test were used to examine the proliferation,apoptosis and migration of PANC1 cells,respectively.ResultsIn the control group and 100,200,400 and 800 μmol/L CoCl-2 groups,the expressions of HIF-1t mRNA were 1,1.08 ±0.12,1.12 ± 0.09,1.04±0.11,0.66 ±0.07,and the expressions of VEGF mRNA were 1,2.69±0.35,4.81 ±0.54,2.19 ± 0.21,0.79 ± 0.08,while the expressions of HIF-1 α protein were 0.23 ± 0.03,0.36 ± 0.04,1.15 ± 0.11,1.08 ± 0.09,0.44 ± 0.04; and the expressions of VEGF protein were 0.14 ± 0.02,0.12 ± 0.01,0.95 ±0.09,0.87 ±0.09,0.55 ±0.06; and cell viability rates were 100％,(98.43 ±2.88)％,(76.15 ± 0.70)％,(53.87 ±0.77)％,(35.23 ±0.67)％ ; while cell apoptotic rates were (5.2 ±1.12)％,(5.74 ± 1.07)％,(6.82 ± 1.85)％,(12.09 ±3.53)％,(31.88 ±6.95)％ ; the cell migration distance of PANC1 cells were (43.24 ±3.67)％,(59.46 ±5.39)％,(80.56 ±8.05)％,(63.89 ±5.96)％,(9.09 ± 1.59 ) ％.Compared with those of control group,the expressions of VEGF mRNA,VEGF and HIF-1 α protein,cell migration distance showed a two-way variation ( ascending first and descending later) (P ＜0.05 ),and the expression of HIF-1α mRNA and cell proliferation rate was decreased in a dose-dependent manner,while the cell apoptosis was increased in a dose-dependent manner.Conclusions CoCl2 significantly inhibits the proliferation and promotes apoptosis of PANC1 cells at certain level.CoCl2 has a two-way effect on the migration of PANC1 cells,and it may be related to the direct injury of high concentration of CoCl2 on cells.

ObjectiveTo detect the mRNA and protein expressions of Bmi-1 in hepatocellular carcinoma (HCC) tissue,pericarcinomatous tissue,portal vein tumor thrombus and normal liver tissue,and to investiage the significance of Bmi-1 in the genesis and progression of HCC.MethodsForty tissues of HCC were collected from the Tongji Hospital of Huazhong University of Science and Technology from January 2005 to December 2009.The mRNA and protein expressions of Bmi-1 in the HCC tissues (40 cases),pericarcinomatous tissues (40 cases),portal vein tumor thrombus ( 11 cases) and normal liver tissues ( 10 cases) were detected by immunohistochemistry,Western blot and real-time polymerase chain reaction.The relationship between the expressions of Bmi-1 and the clinicopathological factors was analyzed.Differences in each group were compared by using the Nemenyi test or Dunnet t test,and the relationship between the clinicopathological factors and the protein expression in the HCC tissues was analyzed by the chi-square test or Fisher exact probability.The survival curve was drawn by the Kaplan-Meier method,and the survival rate was analyzed by the Log-rank test.Results The median relative mRNA expressions of Bmi-1 in the normal liver tissues,pericarcinomatous tissues,HCC tissues and portal vein tumor thrombus were 0.96,2.60,7.51 and 29.95,respectively.The results of immunohistochemistry showed that the high protein expression rates of Bmi-1 in the normal liver tissues,pericarcinomatous tissues,HCC tissues and portal vein tumor thrombus were 10.0％,20.0％,67.5％ and 100.0％,respectively.The high protein expression rates of Bmi-1 in the HCC tissues and portal vein tumor thrombus were significantly higher than those in the normal liver tissues and pericarcinomatous tissues (x2 =17.25,22.77;22.04,23.95,P ＜ 0.05 ). High protein expression of Bmi-1 was also detected in 11 cases of HCC tissues with portal vein tumor thrombus.The results of western blot were consistent with those of the immunohistochemistry.The mRNA and protein expressions of Bmi-1 were correlated with Edmondson grade and portal vein metastasis ( x2 =5.572,P ＜ 0.05 ),whereas they were irrelevant to the tumor size,serum levels of α-fetoprotein and hepatitis B surface antigen ( x2 =0.000,0.019,0.663,P ＞0.05).Patients with high expression of Bmi-1 had poor prognosis.ConclusionsBmi-1 is correlated with the genesis and progression of HCC as well as the formation of portal vein tumor thrombosis.Patients with high Bmi-1 expression have poorer prognosis when compared with those with low Bmi-1 expression.

Objective To investigate the expressions of RGC-32 and E-cadherin in pancreatic cancer and analyze their clinicopathological significance and the correlation with each other.Methods SP immunohistochemistry was used to detect the expressions of RGC-32 and E-cadherin in 42 cases of pancreatic cancer tissues,12 cases of chronic pancreatitis tissues and 8 cases of normal pancreatic tissues.Results The positive staining for RGC-32 was predominantly observed in the cytoplasm of pancreatic acinar cells.The positive staining for E-cadherin was mainly observed in the cytomembrane of normal pancreatic and chronic pancreatitis acinar cells,but aberrant expression ( cytoplasm expression and ( or ) weaker expression) could be found in pancreatic cancer cells.The positive expression rate of RGC-32 and aberrant expression rate of E-cadherin were 78.6％ (33/42) and 54.8％ (23/42),respectively,in pancreatic cancer tissues,which were significantly higher than those in normal pancreatic tissues [37.5％ (3/8) and 0] and chronic pancreatitis [41.7％ (5/12)and 8.3％ (1/12) with statisticai significance,P ＜0.05].The expression of RG C-32 in pancreatic cancer was associated with lymph node metastasis and TNM staging (P =0.016,0.025,respectively),but not with age,gender and differentiation degree ( P =0.831,1.000,0.629,respectively).The aberrant expression of E-cadherin was associated with differentiation degree,lymph node metastasis and TNM staging ( P =0.024,0.004,0.004,respectively),but not with age and gender ( P =0.970,1.000,respectively).A significantly positive correlation was found between positive expression rate of RGC-32 and aberrant expression rate of E-cadherin (r =0.458,P ＜0.01 ).Conclusions Both positive expression rate of RGC-32 and aberrant expression rate of E-cadherin are up-regulated significantly in pancreatic cancer tissues and RGC-32 may be involved in the invasion and metastasis of pancreatic cancer by regulating epithelial mesenchymal transition.