ABSTRACT
Objective The purpose of this study was to investigate the knowledge，attitude and behaviors (KAB) of rural residents. Methods A correlative-descriptive design was used for the study. A cluster sampling of 1952 rural residents aged 18-60 years old in 8 villages of Lantian county was selected. Results The results showed as follows. The total correct rate of knowledge was 50.9%; 43.5% believed that the prevalence of HIV/AIDS in China indicated decline of the moral value; 71.3% never use condom when having sex in the past;There were positive relationships between knowledge and attitude,using condoms during sex and using condoms during first sex respectively (P<0.01). Conclusion The attitude and behavior on HIV/AIDS of the rural residents are largely determined by their knowledge.
ABSTRACT
Objective To investigate the best protective solution that could maintain the cell activity and prolong the survival time of the human retinal pigment epithelium (hRPE) cells after break away in vitro culture case. Methods hRPE cells (stored in our laboratory) culture in DMEM/F12, added 10% FBS, EGF 20?g/L and bFGF 20?g/L, which had been cultured for more than five generations. When these culture hRPE cells had been confluenced more than 80%, the hRPE cells were harvested and placed into six kinds of protective solutions (balanced salt solution, Quinn's advantage medium, physiological salt solution, 18-amino acid solution, 5% glucose solution, artificial cerebrospinal fluid), then the cells were stained with the Annexin V /FITC, and the numbers of cell death and cell apoptosis were detected with the fluorescence activated cell sorter (FACS). The hRPE cells were in six kinds of protective solutions and were investigated at three different times from 2 hours to 8 hours. Results The result presented as follows: At the room temperature, the hRPE cells in all six kinds of protective solutions occurred necrosis within 30 minutes. To investigate the state at 4℃, in a duration of 2 hours, the apoptosis rate in the group of balanced salt solution was lowest (0.9%); As compared with the group of balanced salt solution, the apoptosis rate of artificial cerebrospinal presented a great difference (P
ABSTRACT
To control thrombopoietin (TPO) expression by doxycycline in CHO cells, Tet-On gene expression system was used. Recombinant plasmid pTRE-TPO was successfully constructed. pTRE-TPO and pTK-Hyg were cotransfected into CHO-Tet-On cells. Cells resistant to hygromycin were cloned, high expression and low background clone was selected, and named as CHO-Tet-On-TPO. There was no significant TPO expression in the absence of doxycycline, the TPO level in the cell culture supernatant was 0.1 micro g/L. After exposure to 2 mg/L doxycycline, TPO expression was greatly increased, the TPO level in the cell culture supernatant reached 10.8 micro g/L. Tet-On gene expression system is a ready access to the tight-regulated and high-level gene expression system. It is likely to provide a safe and regulatable way for TPO gene therapy.