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 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.

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 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 evaluate the effect of the conspecific bone marrow mesenchymal stem cells (MSCs) infusion on the platelets count and the ratio of CD4+ CD25highCD127low regulatory T (Treg) cells in mice with immune thrombocytopenia and the mechanisms.Method ITP mice models were induced by daily intraperitoneal injection of 200 μL phosphate buffer solution [containing 2 μg rat anti-platelet membrane CD41 antibody (MWReg30)] into female Balb/c mice.MSCs were got from male mice.Then different number of MSCs was injected into ITP mice through the tail veins.After 5,7 and 14 days,the number of blood platelets was counted and the ratio of Treg cells was detected by flow cytometry,and compared with those in the healthy mice.Result Twenty-four h after injection of CD41 antibody,platelet counts were reduced sharply to the lowest point,which was about a quarter of the normal level.Then ITP mice models were induced successfully.Platelet counts were increased after the injection of MSCs.On 7th day after injection of MSCs,the platelet counts were significantly higher than those in control mice,and the greater the degree of injection dosage,the greater the elevated platelets (P＜0.05 for all).The ratio of Treg cells in ITP mice models was significantly lower than in the normal mice.The ratio of peripheral blood Treg cells in ITP mice was increased after injection of MSCs and the higher the dose,the greater the effect (P＜0.05 for all) but did not reach the normal level.Conclusion The conspecific bone marrow MSCs infusion can increase the platelet counts in mice with ITP,which may be related to the increase of CD4+ CD25highCD127low Treg 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.

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.

Objective To investigate the expression of livin in hepatocarcinoma tissues and its relationship with hepatitis B virus X protein. Methods Immunohistochemistry was used to detect the expression of livin in 30 cases of hepatic carcinoma tissues and 10 cases of normal liver tissues. Stable L02 cell hne tansfected with HBx was established. Real-time PCR and Western blot were used to observe the expression of livin gene before and after the HBx transfeetion. Results The protein expression of livin was higher in hepatocarcinoma tissues than in normal tissues, and correlated with the exist of portal vein cancer embolus (t = 2.24, P = 0.033 ; P<0.05), but it was not correlated with cancer size or classification pathologically(t = 1.688, P = 0.103 ; γ = - 0.137, P = 0.471 ; P＞0.05). Livin Mrna expression was up-regulated after the HBx gene transfection (t = 6.73, P<0.05). Conclusions Apoptosis inhibition induced by livin up-regulation may play a role in pathogenesis and development of hepatocarcinoma. HBx up-regulates livin expression at transcriptional level.