Stability of a type 2 diabetes rat model induced by high-fat diet feeding with low-dose streptozotocin injection / 浙江大学学报（英文版）（B辑：生物医学和生物技术）

OBJECTIVE@#The present study aims at determining the stability of a popular type 2 diabetes rat model induced by a high-fat diet combined with a low-dose streptozotocin injection.@*METHODS@#Wistar rats were fed with a high-fat diet for 8 weeks followed by a one-time injection of 25 or 35 mg/kg streptozotocin to induce type 2 diabetes. Then the diabetic rats were fed with regular diet/high-fat diet for 4 weeks. Changes in biochemical parameters were monitored during the 4 weeks.@*RESULTS@#All the rats developed more severe dyslipidemia and hepatic dysfunction after streptozotocin injection. The features of 35 mg/kg streptozotocin rats more resembled type 1 diabetes with decreased body weight and blood insulin. Rats with 25 mg/kg streptozotocin followed by normal diet feeding showed normalized blood glucose level and pancreatic structure, indicating that normal diet might help recovery from certain symptoms of type 2 diabetes. In comparison, diabetic rats fed with high-fat diet presented decreased but relatively stable blood glucose level, and this was significantly higher than that of the control group (P<0.05).@*CONCLUSIONS@#This model easily recovers with normal diet feeding. A high-fat diet is suggested as the background diet in future pharmacological studies using this model.

Induction of robust senescence-associated secretory phenotype in mouse NIH-3T3 cells by mitomycin C / 生理学报

Senescence-associated secretory phenotype (SASP) is often a concomitant result of cell senescence, embodied by the enhanced function of secretion. The SASP factors secreted by senescent cells include cytokines, proteases and chemokines, etc, which can exert great influence on local as well as systemic environment and participate in the process of cell senescence, immunoregulation, angiogenesis, cell proliferation and tumor invasion, etc. Relative to the abundance of SASP models in human cells, the in vitro SASP model derived from mouse cells is scarce at present. Therefore, the study aimed to establish a mouse SASP model to facilitate the research in the field. With this objective, we treated the INK4a-deficient mouse NIH-3T3 cells and the wildtype mouse embryonic fibroblasts (MEF) respectively with mitomycin C (MMC), an anticarcinoma drug which could induce DNA damage. The occurring of cell senescence was evaluated by cell morphology, β-gal staining, integration ratio of EdU and Western blot. Quantitative RT-PCR and ELISA were used to detect the expression and secretion of SASP factors, respectively. The results showed that, 8 days after the treatment of NIH-3T3 cells with MMC (1 μg/mL) for 12 h or 24 h, the cells became enlarged and the ratios of β-gal-positive (blue-stained) cells significantly increased, up to 77.4% and 90.4%, respectively. Meanwhile, the expression of P21 protein increased and the integration ratios of EdU significantly decreased (P < 0.01). Quantitative RT-PCR detection showed that the mRNA levels of several SASP genes, including IL-6, TNF-α, IL-1α and IL-1β increased evidently. ELISA detection further observed an enhanced secretion of IL-6 (P < 0.01). On the contrary, although wildtype MEF could also be induced into senescence by MMC treatment for 12 h or 24 h, embodied by the enlarged cell volume, increased ratios of β-gal-positive cells (up to 71.7% and 80.2%, respectively) and enhanced expression of P21 protein, the secretion of IL-6 displayed no significant change. Our study indicated that, although MMC could induce senescence in both mouse NIH-3T3 cells and wildtype MEF, only senescent NIH-3T3 cells displayed the canonical SASP phenomena. Current study suggested that senescent NIH-3T3 cells might be an appropriate in vitro SASP model of mouse cells.

Knowledge, attitudes and practices regarding human papillomavirus vaccination among young women attending a tertiary institution in Singapore

<p><b>INTRODUCTION</b>This study aimed to describe the knowledge, attitudes and practices of young women regarding human papillomavirus (HPV) vaccination.</p><p><b>METHODS</b>We conducted a descriptive, cross-sectional, questionnaire-based study among female students at a tertiary institute in Singapore.</p><p><b>RESULTS</b>A total of 255 questionnaires were completed and formed the basis of the analysis. 244 (95.7%) of the total participants were of the age group 15-22 years. 252 (98.8%) participants were unmarried and 240 (94.1%) had never had sexual intercourse. Only 25 (9.8%) women had received vaccination. Among the unvaccinated participants, 96 (41.7%) had no intention to receive HPV vaccination and 62 of them cited lack of information as a major barrier to HPV vaccination. Knowledge of cervical cancer and HPV vaccination was also assessed and graded via a point system, with a maximum score of 14. Knowledge was found to be low, with a median score of 7. There was a significant association between HPV vaccination uptake and the source from which they first heard about the vaccine (p = 0.007). Vaccinated respondents tended to first hear about it from their relatives and friends, as compared to unvaccinated respondents (60.0% vs. 27.0%).</p><p><b>CONCLUSION</b>There is poor uptake of HPV vaccination amongst Singapore's susceptible youth as well as poor knowledge of cervical cancer and HPV vaccination. Public health education regarding cervical cancer and HPV vaccination is still needed and has to be targeted at not only respondents, but also their family and friends.</p>