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Objective: To investigate the selective killing of colorectal tumor cells by lentivirus-mediated double suicide gene under the regulation of KDR promoter., Methods: 293T packaging cells were transfected with the plasmid FGW-KDRP-CD/TK to obtain the infectious viruses. KDR-expressing LoVo cells and LS174T cells that did not produce KDR were transfected with the recombinant virus, and the transfection efficiency was evaluated by the fluorecence microscope. RT-PCR was employed to examine the expression of CDglyTK. After treatment of the cells with 5-FC and GCV, the killing effects on the two cell lines were evaluated., Results: The recombinant construct showed similar infection rate of the two cell lines. RT-PCR demonstrated that CDglyTK gene was expressed only in LoVo cells infected with FGW-KDRP-CD/TK but not in LS147T cells, and the sensitivity of the two cell lines to the prodrugs was significantly different (P<0.001). The killing effect of the double suicide gene was much stronger than that of single suicide gene administered (P<0.001)., Conclusion: The double suicide gene driven by KDR promoter has specific killing effect on the KDR-expressing colorectal tumor cells.

Objective: To evaluate the immunological characteristics of an immunonanoparticles targeting to human lens epithelial cells and to study if it could internalize into and inhibit the proliferation of target cells in vitro., Methods: Crosslinker carbodiimide was used to couple McAb HILE6 (anti-lens epithelial cells antibody) with 5-fluourouracil-loaded polyactic acid nanoparticles PLA (5-FU)-NP to prepare the immunonanoparticles HILE6-PLA (5-FU)-NP. The molar ratio of HILE6 and 5-FU in the immunonanoparticles were observed. The immunological activity of the antibodies in the immunonanoparticles was assessed by ELISA. The third passage lens epithelial cells were divided into four groups; immunonanoparticles, 5-FU nanoparticles, mixed HILE6 and 5-FU nanoparticles and the controls. The proliferation of lens epithelial cells were evaluated by MTT analysis. Internalization of immunonanoparticles, 5-FU nanoparticles and McAb HILE6 were observed by indirect immunofluorescence study of lens epithelial cells., Results: The molar ratio of 5-FU to HILE6 in the immunonanoparticles was 1809:1 and 84% of the original immunological activity of antibodies could be retained. The immunonanoparticles inhibited the proliferation of lens epithelial cells, which was significantly greater than original 5-FU nanoparticles or the blend group. The IC(50) inhibition of immunonanoparticles was 5.0 microg/ml 2 hours after treatment. The immunonanoparticles were bound to the cells surface in 30 minutes; internalized in 2 hours and accumulated around the nucleus after 4 hours., Conclusion: The immunonanoparticles retain immunological activity and could specifically internalize into the lens epithelial cells to inhibit their proliferation.

Objective: To study the effect of X-ray on gene transfer and the antitumoral effect of X-ray combined with suicide gene therapy on colorectal carcinoma cells., Methods: Green fluorescent protein (GFP) was seen under fluorescent microscope. GFP gene was used for reporting gene to learn gene transfer efficiency and gene expressing time under the influence of radiation. G418 was used to select cytosine deaminase (CD) positive neoplasm cells and CD gene transfer efficiency was tested by cloning efficiency. Antitumoral effect of X-ray combined with CD and 5-FC on colorectal carcinoma cells was tested by MTT., Results: 4 Gy radiation could improve supercoiled plasmid DNA transfer efficiency for about 2 - 4 times and 30 times for linearized plasmid DNA. The mean durations of GFP gene expression treated with 4 Gy radiation were 14 d for supercoiled plasmid and 21 and for linearized plasmid, while in control group, the time was 12 d. Middle-dose radiation combined with CD and 5-FC could kill 99 percent of colorectal carcinoma cells, while in the control group, 5-FC only killed 15 percent of colorectal carcinoma cells which were transduced with CD gene., Conclusions: X-Ray combined with suicide gene therapy may be used as a promising method for treating colorectal neoplasm.

Objective: To discuss the long-term effect of inducible nitric oxide synthase inhibitor S-methylisothiourea (SMT) on repair of articular cartilage defects., Methods: Twenty-four adult New Zealand White rabbits with full-thickness defects of cartilage created in the trochlear groove of their bilateral femurs were divided into three groups randomly, 8 in each group: (1) control group in which nothing was filled into the defects; (2) BMP group in which the defects were filled with collagen fibrin gel impregnated with recombinant human bone morphogenic protein (rhBMP); and (3) SMT group in which the defects were filled with collagen fibrin gel impregnated with rhBMP and hypodermic injection of SMT (5 mg .(-1) 12 h(-1)) was given. The animals were killed one year later. The gross appearance of the defects was assessed. The amount of released NO and the activity of NOS were examined by chemical colorimetry. The distribution of collagen was examined by immunohistochemistry. The proteoglycan synthesis and cell activity was assessed by incorporation of radiolabelled sodium sulphate Na(2)(35)SO(4) and bromodeoxyuridine., Results: One year after the defects in SMT group showed greater improvement in margin integration, cellular morphology, and architecture within defect than those in BMP group and control group (P < 0.01). Immunohistochemistry showed that there was less type-I collagen and more type-II collagen in SMT group than in the other two groups. Radiolabelled sodium sulphate (Na(2)(35)SO(4)) incorporation test showed that the proteoglycan synthesis in defects was higher in SMT group than in the other two groups (P < 0.01). BrdU incorporation test showed cells in repaired tissue with remarkable proliferous activity., Conclusion: iNOS inhibitor SMT significantly improves the quality of repair of defected cartilage and delays its degradation.

To evaluate the anti-osteoporosis effect of clodronate in ovariectomized rats, 44 female Wistar rats, aged 8 months, were divided randomly into 4 groups: the SHAM group (subjected to sham operation); the OVX group (subjected to bilateral ovariectomy); the E3 group (subjected to bilateral ovariectomy and treated after surgery with nilestriol 1 mg/kg BW by gavage once a week for 12 weeks), and the clodronate group (subjected to bilateral ovariectomy and treated after surgery with clodronate 5 mg/kg BW by subcutaneous injection twice a week for 12 weeks). All the animals were sacrificed 12 weeks after the operation. The blood and urine samples were collected for determination of biochemical indices. The humeri and tibiae were prepared for determination of net weight, ash weight, calcium and phosphorus content, bone density, as well as bone histopathology and histomorphometry. The left femora were processed for bone anti-curve power. The results showed that as compared with the SHAM group, the net weight, ash weight, calcium content, density and anti-curve power of bones, te trabecular bone volume and thickness were all significantly reduced in the OVS group, while its osteoblast index, osteoclast index and urine hydroxyproline content were obviously close to normal levels. The data indicates that both clodronate and E3 can effectively prevent bone loss in ovariectomized rats.

Purpose: To evaluate the potential effect of interferon-alpha 2b(IFN alpha-2b) as antifibrotic treatment after glaucoma filtering surgery., Methods: The MTT method was used to study the inhibitory effect of IFN alpha-2b on human Tenon capsule fibroblasts in vitro. The antimetabolites including 5-fluorouracil (5-FU), homoharringtonine(H.H) and mitomycin C(MMC) were also assessed., Results: The IC50 values of IFN alpha-2b, 5-FU, H.H and MMC on fibroblasts at 48 hours were 60.578 mg/L, 5.447 mg/L, 0.531 mg/L, 1.329 mg/L respectively., Conclusion: The effect of IFN alpha-2b to inhibit proliferation of fibroblast was less than that of antimetabolites. Further investigation of other aspects of suppress(suppress) wound healing as a possible antifibrotic agent should be deserved.