科创中国

目的 探讨粪便肠脱落细胞、组织细胞中端粒酶活性表达对大肠癌早期诊断的意义.方法 端粒酶PCR-ELISA检测法检测30例大肠癌患者、30例大肠腺瘤患者及30例对照组健康自愿者粪便肠脱落细胞及对应组织细胞标本中端粒酶活性表达.结果 大肠癌组粪便肠脱落细胞标本中,端粒酶阳性表达率为83.3% (25/30).大肠腺瘤组粪便肠脱落细胞标本中,端粒酶阳性表达率为66.6% (20/30).对照组粪便肠脱落细胞中端粒酶阳性表达率为3.3% (1/30).27例大肠癌组织端粒酶表达阳性的患者有25例其对应的粪便肠脱落细胞端粒酶活性也呈阳性表达.结论 粪便肠脱落细胞端粒酶活性表达对大肠癌的早期诊断具有重要意义.

We validated a radioimmunoassay-based method quantifying fecal glucocorticoid metabolites (FGMs) from captive male and female Richardson's ground squirrels Urocitellus richardsonii. Blood samples were drawn to explore the correlation between plasma cortisol and FGM concentrations. We also injected groups of squirrels with normal saline (CTL; control), adre- nocorticotropic hormone (ACTH; stimulating adrenal activity), or dexamethasone (DEX; suppressing adrenal activity). Potential correlations between stress and behaviour were explored through quantification of fecal pellet production and the intervention necessary to elicit defecation, as well as the behaviour of subjects in the context of handling. Changes in plasma cortisol concen- tration between capture (baseline), and following handling (stress-induced) were also quantified for free-living squirrels. While glucocorticoid concentrations recovered from feces during our captive-animal study were not well correlated with plasma eortisol concentrations, and uncorrelated with defecation or behaviour, FGM concentrations did reflect the activation of the hypothalamic- pituitary-adrenal (HPA) axis. FGM concentrations increased significantly during initial captivity, but declined to baseline level as individuals acclimated to the novel environment. Injection of subjects with ACTH increased FGMs above baseline, confirming activation of the HPA axis. Plasma cortisol concentrations increased significantly with induced stress, indicating that capture and handling activated the glucocorticoid stress response even among previously handled, free-living subjects. Our findings validate a non-invasive tool that will afford new insight into the physiological processes underlying social, reproductive and antipredator behaviour of Richardson's ground squirrels [Current Zoology 60 (5): 591-601, 2014 ].