The effects and mechanisms of exogenous phosphatase and tensin homolog deleted from chromosome ten (PTEN) gene on phosphatase activity-dependent apoptosis of breast cancer cell line MDA468 were investigated. PTEN gene packaged with lipofectin was transferred into breast cancer cell line MDA468 and parental MDA468 cells served as controls. RT-PCR and Western blot were done to detect the expression of target genes. The expression of phosphospecific protein kinase B (PKB/Akt) and focal adhesion kinase (FAK) protein stimulated by epidermal growth factor (EGF) was also detected. Apoptosis was determined by flow cytometry with a double-staining method using FITC-conjugated annexin V and PI. MDA468 cells transfected with PTEN gene could express PTEN mRNA and protein. PTEN decreased the phosphorylation level of AKT protein and down-regulated FAK protein expression in MDA468 stimulated by EGF. The apoptosis rate was 21.68%. PTEN induced breast cancer apoptosis phosphatase activity-dependently. The mechanism is possibly related with phosphoinositide 3-kinase (PI3K)/protein kinase B (PKB)/AKT signaling pathway. Those results may provide new clues on the gene therapy in breast cancer.

In order to study bladder intravesical instillation methods in pure line LEW rats and nude mice, female LEW rats and nude mice aged 2 to 4 weeks were sacrificed. Their urethra and bladder were observed under anatomical microscopy. A trochar was prepared according to the outline and angle of the urethra. Ink was poured into female rats and nude mice bladder though urethra. Filling and staining of bladder were observed and evaluated under anatomical microscopy. Status and methral injury of rats and mice were observed. The results showed that urethra anatomic structure of rats and nude mice was different from that of human urethra. When bladder was filled with ink and became blue, liquid was not seen to leak out. The success rate of intubation was high (100%). Living activities of animals weren’t influenced by intravesical instillation. It was concluded that bladder irrigation might be a kind of valid and utilizable method in pure line rat and nude mouse empirical study. The model may be a more effective tool for study of bladder tumor.

In order to study the effect of excessive iodine on immune function of lymphocytes and the role of selenium supplementation with excessive iodine intake, the changes of T lymphocyte number, ratio of subsets, activity of natural killer (NK) cells and lymphocytes proliferation response were investigated. 150 female BALB/C mice were randomly divided into 5 groups in terms of their body weight (n=30 in each group), and 10 of each group were taken as one batch for test. Mice in the 5 groups were orally administrated with iodine 0 (group I), 1500 (group II), 3000 (group III), 6000 μg/L (group IV), iodine 6000 μg/L plus selenium 0.3 mg/L (group V) respectively for 30 days Lymphocyte proliferation response, CD4⁺/CD8⁺, Th1/Th2 and the activity of NK cells were measured. CD4⁺/CD8⁺ was significantly lower, while lymphocyte proliferation response stronger, and Th1/Th2 and the activity of NK cells significantly higher in group IV than in group I (P<0.01). There was no significant difference in all indexes between group V and group I (P>0.05). It was suggested that excessive iodine as exogenous chemical materials can induce disorders of T lymphocyte immune function in mice. 0.3 mg/L selenium supplementation can protect mice against toxicity induced by 6000 μg/L iodine.

In order to investigate the effects of eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA) on the proliferation, apoptosis of pancreatic cancer cell line SW1990 cells and the expression of cyclin E mRNA, the SW1990 cells were treated with different concentrations of EPA or DHA (20, 40, 60 μg/mL) for 0, 12, 24, 36 and 48 h respectively. By using MTT method, the inhibitory effects of EPA or DHA on the cell growth were assayed. Real time PCR was used to detect the expression changes of cyclin E mRNA after the SW1990 cells were treated with 40 μg/mL EPA or DHA for different time. Flow cytometry was used to test the changes of apoptostic rate in the SW1990 cells treated with different concentrations of EPA or DHA for 24 h. The results showed that EPA and DHA could inhibit the growth of SW1990 cells in a time-and concentration-dependent manner (P<0.01). EPA or DHA could also significantly inhibit the expression of cyclin E mRNA in a time-dependent manner (P<0.05). EPA or DHA could induce the apoptosis of SW1990 cells in a concentration-dependent manner (P<0.01). It was concluded that ω-3 fatty acid could inhibit the proliferation of pancreatic cancer cell line SW1990 cells and promote their apoptosis. The down-regulation of the cyclin E expression by ω-3 fatty acid might be one of the mechanisms for its anti-tumor effect on pancreatic cancer.

To evaluate the morphology of atrial septum by the live three-dimensional echocardiography (L3DE) and its value of clinical application, L3DE was performed in 62 subjects to observe the morphological characteristics and dynamic change of the overall anatomic structure of atrial septum. The study examined 49 patients with atrial septal defect (ASD), including 3 patients with atrial septal aneursym, and 10 healthy subjects. ASD in the 35 patients was surgically confirmed. The maximal diameters of ASD were measured and the percentages of area change were calculated. The parameters derived from L3DE were compared with intraoperative measurements. The results showed that L3DE could directly and clearly display the morphological features of overall anatomic structure of normal atrial septum, repaired and artificially-occluded atrial septum, atrial septal aneurysm. The defect area in ASD patients changed significantly during cardiac cycle, which reached a maximum at end-systole and a minimum at end-diastole, with a mean change percentage of 46.6%, ranging from 14.8% to 73.4%. The sizes obtained from L3DE bore an excellent correlation with intraoperative findings (r=0.90). It is concluded that L3DE can clearly display the overall morphological features and dynamic change of atrial septum and measure the size of ASD area accurately, which is important in the decision to choose therapeutic protocols.