Effect of PTENP1 on Proliferation and Apoptosis of Colorectal Cancer Cells and Its Molecular Mechanism / 肿瘤防治研究

Objective To investigate the effect of PTENP1 on the proliferation and apoptosis of colorectal cancer cells and its molecular mechanism. Methods We selected 107 cases of colorectal cancer and corresponding adjacent tissues as the research objects. The expression level of PTENP1 was analyzed by fluorescence quantitative PCR. Colon cancer HT29 cells with PTENP1 overexpression (PTENP1 group) and empty vector cell line (control group) were established by lentivirus. The cell proliferation and apoptosis were analyzed by CCK8 and flow cytometry. The PTENP1 target gene was analyzed by bioinformatics and double luciferase reporter genes. The expression level of target protein was analyzed by Western blot. Results The expression of PTENP1 in colorectal cancer tissues was significantly lower than that in adjacent tissues (P < 0.05). The expression level of PTENP1 in the control group was significantly lower than that in the PTENP1 group (P < 0.05). Compared with the control group, the cell proliferation ability of the PTENP1 group was significantly decreased (P < 0.05), the apoptosis level was significantly increased (P < 0.05). miR-21 was complementary to PTENP1. Compared with the control group, the expression of miR-21 in the PTENP1 group was significantly down-regulated (P < 0.05), and the expression of PTEN protein was significantly up-regulated (P < 0.05). Conclusion PTENP1 and miR-21 competitively bind to regulate the expression of PTEN, and then affect the proliferation and apoptosis of colorectal cancer cells.

Surveillance of Escherichia coli O157:H7 among animals in Jiangsu province in 1999 / 中华流行病学杂志

<p><b>OBJECTIVE</b>To understand the Escherichia coli O157:H7 carrier rate of host animals and the toxic gene of the strains in different areas in Jiangsu province.</p><p><b>METHODS</b>Surveillance spots were set up in different areas, to collect feces of pigs, chickens, sheep, cattle to culture for O157:H7 with immunomagnetic separation as well as detection of toxic gene of the strain with MPCR were both carried out.</p><p><b>RESULTS</b>One hundred and seventy strains of O157:H7 were separated from 1 767 feces of different animals in six spots, with a overall positive rate 9.62%. The positive rates of cattle and sheep were 19.05% and 12.01% respectively. Among 85 strains SLT1, SLT2, eaeA and hly toxic genes were detected. In which, 56.47% of the strains were positive curturely while 79.17% of them carried SLT2, eaeA and hly gene simultaneously.</p><p><b>CONCLUSION</b>The positive rate of O157:H7 in animals and the positive rates of strains were correlated to the incidence of the area. The highest rates were seen in areas where there had been O157:H7 epidemic, followed by the areas where there were only scattered cases identified while the lowest was in areas with no patients. Data indicated that it was important to enforce the surveillance of O157:H7 in animals to better predict and control of the disease.</p>

Effects of three different iodine interventions on the speed of normalization of enlarged thyroid gland due to iodine deficiency / 中华流行病学杂志

<p><b>OBJECTIVE</b>To compare the effects of three different iodine interventions on the speed of normalization of enlarged thyroid gland.</p><p><b>METHODS</b>Schoolchildren aged 8 - 10 years were randomized divided into one of three groups: group A was given iodized salt by researchers with an iodine concentration of 25 mg/kg; group B used iodized salt purchased from the market; and group C was similar to group B with additional intake of iodized oil capsules containing 400 mg iodine at the beginning of the study. Salt iodine content was measured bimonthly for 18 months and indicators of iodine deficiency were measured at baseline and 6, 9, 12 and 18 months thereafter.</p><p><b>RESULTS</b>The prevalence of goiter measured by ultrasound, based on the World Health Organization (WHO) body surface area reference > 97(th) percentile, was 18% at baseline and declined to less than 5% by 12 month in groups A and C respectively, and to 9% after 18 months in group B. Rates of goiter were similar by palpation or by ultrasound. The median urinary iodine was 94 micro g/L at baseline and increased in all groups to > 200 micro g/L at the 6-month follow-up.</p><p><b>CONCLUSIONS</b>In this sample of schoolchildren with initially low or moderate level of iodine deficiency, the group receiving salt with 25 mg/kg (group A) recovered from iodine deficient on all indicators after 18 months of study. However when the iodine content of salt was floating, as seen in group B, the sizes of thyroid did not yet achieve normal status by 18 months.</p>