With the change of medical mode and deepening of the medical education reforms,such educational idea as giving prominence to practice is widely used to improve students' comprehensive quality and innovative ability and practice ability. The medical shool of Tibet university has established long-term apprentice mechanism during the before class and playtimes and found four county hospitals, five health clinics in towns and townships and gradually improved the construction of mutual win-win 9clinical teaching bases. In this way it has been cultivating many advanced medical personnels, who are reliable, available, able to stay, and highly praised by the employers.

Pseudomonas aeruginosa is one of the most common causes of nosocomial infection due to its intrinsic resistance to antibiotics. In the host,glutathione(GSH) ,one of the most important intracellular antioxidants,provides protection against high levels of oxidative stress. A decrease in GSH levels in tissues infected with P. aeruginosa has been observed while interactions between pyocyanin and GSH maybe partially attribute to P. aeruginosa infection. In this review,the relationship between GSH and the pathogenicity of P. aeruginosa has been discussed based on the author's own research results and the latest literature.

OBJECTIVETo observe the release kinetics of methotrexate-loaded calcium phosphate cement (MTX-CPC) implanted in vivo and histologically investigate its resorption and osteogenesis.

METHODSMTX-CPC consisting of 1% methotrexate (MTX) (weight/weight) was pre-set and implanted into femoral muscles of 24 New Zealand rabbits. The in vivo MTX release kinetics was determined on the 1st, 2nd, 5th, 10th, 15th, 20th, 25th, and 30th post-implantation day. The local concentrations and the residual percentage of MTX were determined. Then the pre-set MTX-CPC was implanted into femoral condyle. Calcium phosphate cement (CPC) without MTX was used as a control. The femurs were harvested at the 1st day and the 1st, 3rd, and 6th month and examined by X ray. Then histomorphometric analyses including percentage of newly formed bone and amount of osteoblast and osteoclast were performed.

RESULTSThe MTX release kinetics in vivo confirmed that MTX-CPC was a monolithic matrix system, with a burst effect in the initial stage and a sudden drop thereafter. The local concentration of the released MTX was 0.372 μg/ml on the 30th post-implantation day; with a concentration higher than the effective concentration,the incorporated MTX was expected to be continuously released over the following 2-3 months. Both MTX-CPC and CPC showed good biodegradability and osteoconduction. Although the release of MTX had an inhibitory effect on osteogenesis, especially in the initial stage, the area of newly formed bone, the amount of osteoblasts, and the amount of osteoclasts were not significantly different between MTX-CPC group and CPC group on the 6th post-implantation month.

CONCLUSIONSMPX-CPC system is an effective drug delivery system. Both MTX-CPC and CPC has good biodegradability and osteoconduction. Therefore,MTX-CPC system can be an ideal material for filling defects and controlling local recurrence.

Animals ; Bone Cements ; Bone Regeneration ; Calcium Phosphates ; Methotrexate ; pharmacokinetics ; Osteogenesis ; Rabbits

OBJECTIVETo study the inhibitory effect of CD133 monoclonal antibody labeled with ¹³¹I (¹³¹I-CD133mAb) on Huh-7 human liver cancer cell line overexpressing CD133 antigen in vitro and in mouse models bearing the tumor cell xenograft.

METHODS¹³¹I-CD133mAb was prepared by chloramines-T method and evaluated for its stability. Flow cytometry and immunohistochemistry were used to detect the expression of CD133 in Huh-7 cells and in Huh-7 cell-derived tumors, respectively. Huh-7 cells treated with ¹³¹I-CD133mAb plus cisplatin (DDP), ¹³¹I -CD133mAb, DDP, or no treatment (blank control) were examined for cell proliferation suppression by MTT assay with the IC₅₀ calculated. BALB/c mice bearing subcutaneous Huh-7 cell xenograft in the right forelegs were treated with ¹³¹I -CD133mAb, DDP, or both every two days for two weeks. The tumor size and volume were measured twice a week, and pathological examination of the tumor was carried out after the treatments. The tumor inhibition rate was calculated and tumor cell apoptosis observed with HE staining.

RESULTSThe labeling ratio of ¹³¹I-CD133mAb was 90.25% and the radiochemical purity was 97.78%. Huh-7 cells showed obviously higher CD133 expression than HepG2 cells. ¹³¹I-CD133mAb combined with DDP group resulted in a significantly higher tumor inhibition rate than other treatments in the tumor-bearing mice.

CONCLUSION¹³¹I-CD133mAb can inhibit the growth of liver cancer cells with a high CD133 expression both in vivo and in vitro.

AC133 Antigen ; Animals ; Antibodies, Monoclonal ; pharmacology ; Antigens, CD ; immunology ; Apoptosis ; Carcinoma, Hepatocellular ; drug therapy ; Cell Line, Tumor ; drug effects ; Cell Proliferation ; Cisplatin ; pharmacology ; Glycoproteins ; immunology ; Hep G2 Cells ; Humans ; Liver Neoplasms ; Mice ; Mice, Inbred BALB C ; Mice, Nude ; Peptides ; immunology ; Xenograft Model Antitumor Assays

OBJECTIVETo investigate the effect of amphotericinB (AmB) on migration and invasion of esophageal carcinoma Eca109 cells exposed to hypoxia and explore the molecular mechanisms.

METHODSRoutinely cultured esophageal carcinoma Eca109 cells were treated with 0, 1.25, 2.5, or 5 µg/ml AmB in hypoxic condition (3% O2, 5% CO2, and 92% N2) for 24 h. The cell migration and invasion were assessed by cell scratch test and Transwell chamber assay, respectively. Real-time quantitative PCR and Western blotting were used to detect the mRNA and protein expressions of hypoxia-inducible factor-1α (HIF-1α), matrix metalloproteinase-2 (MMP-2), and E-cadherin in the cells, respectively.

RESULTSCompared with the control cells, the cells treated with different doses of AmB showed attenuated ability of migration and invasion (P<0.05). AmB treatment resulted in significantly lowered mRNA and protein expressions of MMP-2 (P<0.05) and increased expressions of E-cadherin (P<0.05); the protein expression of HIF-1α decreased significantly in cells after AmB treatment (P<0.05) but its mRNA levels showed no significant changes (P>0.05).

CONCLUSIONAmB can suppress the migration and invasion of esophageal carcinoma Eca109 cells in hypoxic microenvironment possibly by regulating the expressions of HIF-1α, MMP-2 and E-cadherin.

Amphotericin B ; pharmacology ; Cadherins ; metabolism ; Cell Hypoxia ; Cell Line, Tumor ; drug effects ; Cell Movement ; drug effects ; Down-Regulation ; Esophageal Neoplasms ; metabolism ; pathology ; Humans ; Hypoxia-Inducible Factor 1, alpha Subunit ; metabolism ; Matrix Metalloproteinase 2 ; metabolism ; RNA, Messenger

Abstract: 【Objective】To study the effects of notoginsenoside R1 on the levels of intercellular adhesion molecule- 1（ICAM- 1），tumor necrosis factor- α （TNF- α），metalloproteinase- 2 （MMP- 2） and metalloproteinase- 2 inhibitor （TIMP- 2）in rats with atrial fibrillation in order to explore the mechanism of notoginsenoside R1 on the preventing and treating atrial fibrillation. 【Methods】 102 rats were randomly divided into control group ，atrial fibrillation group and notoginsenoside R1 group，with 34 rats in each group. The rat model of atrial fibrillation was established by injection of acetylcholine-calcium chloride into the tail vein. The rats in the notoginsenoside R1 group were intraperitoneally injected with 2 mL of notoginsenoside R1. ECG was used to measure the duration of atrial fibrillation. Masson staining was used to observe the degree of myocardial fibrosis. Immunohistochemistry was used to detect the expression of MMP-2 and TIMP-2 in atrial tissue. The serum ICAM-1，TNF-α，MMP-2 and TIMP-2 levels were determined by enzyme-linked immunosorbent assay（ELISA）. The levels of ICAM-1，TNF-α and type I collagen in atrial tissue were determined by Western blotting.【Results】Before the treatment of notoginsenoside R1 ，there was no significant difference in the duration of atrial fibrillation between the two groups（P > 0.05）. After treatment，the duration of atrial fibrillation in the notoginsenoside R1 group［（6.37±2.02）s］was lower than that in the pre-treatment and the atrial fibrillation groups（P < 0.05）. Masson staining showed：the amount of atrial fibrillar collagen fibers in control group was normal；a large number of collagen fibers were seen in the atrial myocytes of atrial fibrillation group；the patchy and punctate collagen fibers were seen in the atrial myocytes of notoginsenoside R1 group. Compared with control group，the serum levels of ICAM-1，TNF- α and MMP-2 ［（137.52±16.59）10-6 g/L，（14.25±1.08）10-6 g/L，（435.26±17.63）10-9 g/L；（109.25±14.62）10-6 g/L ，（12.31±1.27）10-6 g/L， （288.47±15.52）10-9 g/L］were increased（P < 0.05），the serum levels of TIMP-2 levels［（3 541.27±331.24）10-9 g/L ； （3 975.46 ± 313.24）10- 9 g/L］was decreased（P < 0.05），the atrial tissue ICAM- 1，TNF- α and type I collagen levels （0.23±0.07 ，0.51±0.09 、0.63±0.14 ；0.15±0.06 ，0.22±0.07 ，0.27±0.12）were increased（P < 0.05），the atrial tissue MMP-2 protein optical density（0.35±0.07；0.18±0.06）was increased（P < 0.05），the atrial tissue TIMP-2 protein optical density（0.11±0.04；0.18±0.03）was decreased（P < 0.05）in atrial fibrillation group and the notoginsenoside R1 group； Compared with atrial fibrillation group，the levels of serum ICAM-1，TNF- α and MMP-2 were decreased（P < 0.05）， the levels of serum TIMP-2 was increased（P < 0.05），the atrial tissue ICAM- 1 ，TNF- α and type I collagen levels were decreased（P < 0.05），the density of MMP-2 protein in atrial tissue was decreased（P < 0.05），and the optical density of TIMP-2 protein in atrial tissue was increased（P < 0.05）in the rats in notoginsenoside R1 group.【Conclusion】 Notoginsenoside R1 can prevent and treat atrial fibrillation by reducing the levels of ICAM- 1，TNF- α and MMP-2 and increasing the levels of TIMP-2 in serum and atrial tissue of rats with atrial fibrillation.

Objective To investigate the effect of amphotericinB (AmB) on migration and invasion of esophageal carcinoma Eca109 cells exposed to hypoxia and explore the molecular mechanisms. Methods Routinely cultured esophageal carcinoma Eca109 cells were treated with 0, 1.25, 2.5, or 5μg/ml AmB in hypoxic condition (3%O2, 5%CO2, and 92%N2) for 24 h. The cell migration and invasion were assessed by cell scratch test and Transwell chamber assay, respectively. Real-time quantitative PCR and Western blotting were used to detect the mRNA and protein expressions of hypoxia-inducible factor-1α (HIF-1α), matrix metalloproteinase-2 (MMP-2), and E-cadherin in the cells, respectively. Results Compared with the control cells, the cells treated with different doses of AmB showed attenuated ability of migration and invasion (P<0.05). AmB treatment resulted in significantly lowered mRNA and protein expressions of MMP-2 (P<0.05) and increased expressions of E-cadherin (P<0.05); the protein expression of HIF-1α decreased significantly in cells after AmB treatment (P<0.05) but its mRNA levels showed no significant changes (P>0.05). Conclusion AmB can suppress the migration and invasion of esophageal carcinoma Eca109 cells in hypoxic microenvironment possibly by regulating the expressions of HIF-1α, MMP-2 and E-cadherin.

Objective To study the inhibitory effect of CD133 monoclonal antibody labeled with 131I (131I-CD133mAb) on Huh-7 human liver cancer cell line overexpressing CD133 antigen in vitro and in mouse models bearing the tumor cell xenograft. Methods 131I-CD133mAb was prepared by chloramines-T method and evaluated for its stability. Flow cytometry and immunohistochemistry were used to detect the expression of CD133 in Huh-7 cells and in Huh-7 cell-derived tumors, respectively. Huh-7 cells treated with 131I-CD133mAb plus cisplatin (DDP), 131I-CD133mAb, DDP, or no treatment (blank control) were examined for cell proliferation suppression by MTT assay with the IC50 calculated. BALB/c mice bearing subcutaneous Huh-7 cell xenograft in the right forelegs were treated with 131I-CD133mAb, DDP, or both every two days for two weeks. The tumor size and volume were measured twice a week, and pathological examination of the tumor was carried out after the treatments. The tumor inhibition rate was calculated and tumor cell apoptosis observed with HE staining. Results The labeling ratio of 131I-CD133mAb was 90.25% and the radiochemical purity was 97.78%. Huh-7 cells showed obviously higher CD133 expression than HepG2 cells. 131I-CD133mAb combined with DDP group resulted in a significantly higher tumor inhibition rate than other treatments in the tumor-bearing mice. Conclusion 131I-CD133mAb can inhibit the growth of liver cancer cells with a high CD133 expression both in vivo and in vitro.

Objective To investigate the effect of amphotericinB (AmB) on migration and invasion of esophageal carcinoma Eca109 cells exposed to hypoxia and explore the molecular mechanisms. Methods Routinely cultured esophageal carcinoma Eca109 cells were treated with 0, 1.25, 2.5, or 5μg/ml AmB in hypoxic condition (3%O2, 5%CO2, and 92%N2) for 24 h. The cell migration and invasion were assessed by cell scratch test and Transwell chamber assay, respectively. Real-time quantitative PCR and Western blotting were used to detect the mRNA and protein expressions of hypoxia-inducible factor-1α (HIF-1α), matrix metalloproteinase-2 (MMP-2), and E-cadherin in the cells, respectively. Results Compared with the control cells, the cells treated with different doses of AmB showed attenuated ability of migration and invasion (P<0.05). AmB treatment resulted in significantly lowered mRNA and protein expressions of MMP-2 (P<0.05) and increased expressions of E-cadherin (P<0.05); the protein expression of HIF-1α decreased significantly in cells after AmB treatment (P<0.05) but its mRNA levels showed no significant changes (P>0.05). Conclusion AmB can suppress the migration and invasion of esophageal carcinoma Eca109 cells in hypoxic microenvironment possibly by regulating the expressions of HIF-1α, MMP-2 and E-cadherin.

Objective To study the inhibitory effect of CD133 monoclonal antibody labeled with 131I (131I-CD133mAb) on Huh-7 human liver cancer cell line overexpressing CD133 antigen in vitro and in mouse models bearing the tumor cell xenograft. Methods 131I-CD133mAb was prepared by chloramines-T method and evaluated for its stability. Flow cytometry and immunohistochemistry were used to detect the expression of CD133 in Huh-7 cells and in Huh-7 cell-derived tumors, respectively. Huh-7 cells treated with 131I-CD133mAb plus cisplatin (DDP), 131I-CD133mAb, DDP, or no treatment (blank control) were examined for cell proliferation suppression by MTT assay with the IC50 calculated. BALB/c mice bearing subcutaneous Huh-7 cell xenograft in the right forelegs were treated with 131I-CD133mAb, DDP, or both every two days for two weeks. The tumor size and volume were measured twice a week, and pathological examination of the tumor was carried out after the treatments. The tumor inhibition rate was calculated and tumor cell apoptosis observed with HE staining. Results The labeling ratio of 131I-CD133mAb was 90.25% and the radiochemical purity was 97.78%. Huh-7 cells showed obviously higher CD133 expression than HepG2 cells. 131I-CD133mAb combined with DDP group resulted in a significantly higher tumor inhibition rate than other treatments in the tumor-bearing mice. Conclusion 131I-CD133mAb can inhibit the growth of liver cancer cells with a high CD133 expression both in vivo and in vitro.