Objective To evaluate the therapeutic effect and the mechanism of herpes simplex virus thymidine kinase Ⅰ type (HSV 1\|tk) and Ganciclovir(GCV) in animal model of human glioma. Methods We demonstrated that tk gene was stably integrated into the genome of retrovirus vector producing cell line pN 2A\|tk/VPC(VPC) by Southern blot hybridization; then we established the nude mice model of glioma by inoculating the VPC and the human glioma cells DBTRG\|05MG(05MG) at 1∶1,1∶4 ratios respectively(only inoculated 05MG cells as control group), then GCV treatment was administrated i.p.,30mg/(kg\5d), twice daily for 14 days. A week later, the nude mice were sacrificed and the pathological sections of tumor tissues were observed by light microscopy. Results The tumor mass of 1∶1 group decreased remarkably compared with 1∶4 group or control group respectively ( P

The establishment of a serum-free culture medium (SFM) for SSV-NIH3T3 cells is reported in this paper. In this medium DMEM/Ham's F12 is the fundamental element in basal medium, insulin and undefatty bovine serum albumin are key elements among the supplements. In this SFM SSV-NIH3T3 cells grow well, they keep the ability of secreting platelet-derived growth factor-like material into culture medium and causing tumor growth in nude mice.

The wild type cells of human stomach glandular carcinoma, cell line BGC 823, were treated firstly by a chemical carcinogen (MNNG) for the induction of mutagenesis, then the cells were selected in medium with gradually increasing amount of 8-AG (8-azaguanine) from 1-20?g/ml. It was found that the mutant cells could grow vigorously in the medium containing 20?g/ml of 8-AG but not in HAT medium. The HGPRT assay showed an obvious quantitative difference between the wild type and HGPRT mutant cells of BGC 823.

Objective In this experiment,we explored the effects of rAAV\|hGDNF on protecting spinal neurons From death. Methods rAAV\|hGDNF particals were produced by recombinant virus technolgy,and infected the culture spinal neurons which were exposed to glutamate.We counted the mortality rate and detected the expression of NOS mRNA by RT\|PCR. Results In the group transfering rAAV\|hGDNF the death rate was inhibited(50%?0\^02,control 59\^25%?0\^023, P

Objective:To provide a new morning check method for the output dose stability of the multileaf collimator (MLC) of the CyberKnife M6 (CK-M6) system.Methods:The CT images of a verification phantom with a size of 20 cm × 20 cm × 10 cm were transmitted into the Precision Treatment Plan ning System (ver. 1.1.1.1). The high-precision alignment between the accelerator output front and the fixed position of the phantom surface was achieved using the fiducial tracking method. A 10 cm × 10 cm radiation field was formed by the MLC and a DailyCheck plan with an output of 200 MU was designed. The repeatability, sensitivity, and accuracy of the DailyCheck plan were measured, and the CK-M6 system was continuously tested for one month using the artificial fixed method and the DailyCheck plan designed in this study. Results:The average and the standard deviation of 10 repeated measurements by the DailyCheck plan were 492.28 pC and 0.09, respectively, indicating good stability. There was a linear correlation between the measured values and the output dose, with a correlation coefficient of R2 > 0.999. Moreover, there was a position deviation of 2 mm between the phantom and the accelerator output front, and the result ant effect on the measured values was equivalent to a dose deviation caused by an output of 1.24 MU. The result from the continuous measurement of both the artificial fixed method and the DailyCheck plan fell within permissible limits, showing high consistency. Conclusions:The DailyCheck plan established through the fiducial tracking of a verification phantom can achieve the convenient, quick, and accurate daily detection of the output dose stability of the MLC of CK-M6. Therefore, this method can be widely applied in the clinical quality control of the CK-M6 system.

Objective: To evaluate the efficacy and safety of maintenance therapy with reduced dose of rhTPO in the patients with primary immune thrombocytopenia (ITP) who attained stable platelet (PLT) counts after daily administration of rhTPO. Methods: Treatment was started with a daily administration of rhTPO (300 U/kg) for 2 consecutive weeks. Patients who attained stable PLT≥50×10⁹/L were enrolled to maintenance therapy starting with every other day administration of rhTPO, then adjusted dose interval to maintain platelet count (30-100) ×10⁹/L. Results: A total of 91 eligible patients were enrolled. Fourteen patients discontinued the study due to noncompliance (12/14) and investigator decision (2/14) . Among 77 patients who completed the study, 38 patients with the administration of rhTPO at every other day or less could maintain PLT≥30×10⁹/L for 12 weeks. The percentage of patients with a platelet response (PLT≥30×10⁹/L) at 4^th week, 8^th week and 12^th week of maintain therapy was 92.6% (63/68) , 82.7% (43/52) and 85.0% (34/40) , respectively. Median platelet counts remained in the range of (70-124) ×10⁹/L. The overall incidence of rhTPO-related adverse events was 7.7%. All the adverse events were generally mild. Conclusion Extending the dose interval of rhTPO is feasible to maintain stable platelet count in the patients with ITP, but the optimal dose interval is uncertain and might vary with individuals.