Association of smoking status with incident cardiovascular disease in the middle-aged and older male populations / 中华疾病控制杂志

Objective To investigate the association of smoking status with incident cardiovascular disease (CVD) and its subtypes among the middle-aged and older male populations. Methods This study included 13 940 males from Dongfeng-Tongji (DFTJ) cohort who were free of coronary heart disease (CHD), stroke, cancer or severely abnormal electrocardiogram (ECG) at baseline. All participants completed baseline questionnaires, physical examinations, clinical biochemical tests and blood sample collection. Cox proportional hazard models were used to estimate the hazard ratios (HRs) and 95% confident intervals (CI) for the association analyses. Results Compared with never smokers, current smokers had significant higher risks of CVD, CHD and stroke, the adjusted HRs of current smokers who smoked for more than 40 pack-years were 1.49 (95% CI: 1.32-1.68, Ptrend=0.001), 1.40 (95% CI: 1.22-1.62, Ptrend=0.026) and 1.59 (95% CI: 1.26-2.00, Ptrend=0.029) for CVD, CHD and stroke, respectively; and the adjusted HRs of current smokers who started smoking before 20 years old were 1.29 (95% CI: 1.06-1.58, Ptrend=0.007) and 1.30 (95% CI: 1.03-1.64, Ptrend=0.010) for CVD and CHD, respectively. Former smokers who had quitted smoking for 10 or more years had significant lower risks of CVD (HR: 0.80, 95% CI: 0.71-0.91, Ptrend=0.017) and stroke (HR: 0.65, 95% CI: 0.50-0.84, Ptrend=0.207) when comparing to current smokers. Conclusions Smoking is significantly associated with higher risks of CVD, CHD and stroke, and greater amount of smoking and earlier age at smoking initiation are associated with a higher risk of CVD. Smoking cessation can reduce the risk of CVD.

Culture and identification of tumor stem cells from surgically resected colorectal cancer tissues / 南方医科大学学报

OBJECTIVE@#To obtain cancer stem cells (CSCs) from surgically resected colorectal cancer specimens and identify their stem cell characteristics.@*METHODS@#Colorectal cancer tissue specimen obtained from a patient undergoing radical resection of colorectal cancer were implanted in nude mice, and the xenograft was harvested 1 month later to obtain purified tumor cells by enzyme digestion and adherent culture. The CSCs were screened by limiting dilution method and serum-free culture to identify their phenotypes. Soft agar colony assay was used to assess the proliferative ability of the CSCs and human colorectal cancer cell line SW480. The tumorigenic ability of the isolated CSCs and SW480 cells was evaluated by observing their subcutaneous tumor formation in nude mice. Western blotting and immunofluorescence assay were used to detect the immunophenotype of the CSCs and SW480 cells.@*RESULTS@#The primary cultured CSCs from clinical specimens of colorectal cancer underwent differentiation in the presence of serum in the culture. Soft agar colony formation assay showed that the CSCs had a colony formation rate above 50%, significantly higher than the rate of colorectal cancer SW480 cells (4.41%; < 0.01). In nude mice, subcutaneous injection of 500 CSCs was sufficient to result in subcutaneous tumor formation, while the injection of 500 SW480 cells failed to form any subcutaneous tumors. The CSCs expressed CD133 and CD44 but not CK7, while SW480 cells expressed CK7 but not CD133 or CD44.@*CONCLUSIONS@#CSCs can be derived by primary culture of cancer cells obtained from surgically resected colorectal cancer tissue followed by serum-free culture, and the CSCs obtained have self-renewal and differentiation abilities.

Inhibitive effect of E1A gene on the cell growth of human cervical carcinoma cell in vitro / 中南大学学报(医学版)

OBJECTIVE@#To investigate the inhibitive effect of E1A gene carried by PEI-Fe(3)O(4) nanometer particle (NP) on the cell growth of human cervical carcinoma cell in vitro and its mechanism, and to provide the experimental evidence for the feasibility of gene therapy for human cervical carcinoma.@*METHODS@#E1A gene conjugated to PEI-Fe3O4 NP was transfected into human cervical carcinoma cell line Hela. The cell growth curve of Hela was drawn, the doubling time and the number of colony formations on the soft agar were calculated based on the cell count. RT-PCR and Western blot were used to detect the expression of the E1A and HER-2/neu in Hela cells.@*RESULTS@#The cell doubling time of Hela cells transfected with E1A gene (Hela-E1A) was 1.53 times and 1.58 times longer than that of the Hela transfected with blank vector (Hela-vector) and blank Hela control (Hela), respectively. The E1A transfected Hela cells grew slower than those of the control group. The cell colony formation efficiency in the Hela-E1A (6.62%) group was significantly lower than that of Hela (30.48%) and Hela-vector (28.3%) groups (P<0.05). As compared to Hela and Hela-vector, the inhibition rate of Hela-E1A was 78.28% and 76.62% respectively. RT-PCR and Western blot demonstrated that the overexpression of E1A through gene transfection significantly inhibited mRNA and protein expression of HER-2/neu in Hela cells.@*CONCLUSION@#E1A gene can suppress the cell growth of human cervical carcinoma cell Hela in vitro. Down-regulated expression of HER-2/neu gene by E1A overexpression in Hela might contribute to the Hela growth inhibitive effect of E1A.