转基因及基因打靶技术在耳科学中的应用

转基因(transgene)和基因打靶(gene targeting)技术通过基因的加入或删除建立了大量小鼠模型,尤其是条件性基因敲除为避免小鼠突变体在胚胎期死亡提供了条件.本文主要以参与听觉机械转导、表达于盖膜和纤毛束上的基因及其小鼠模型为例,讨论该技术是如何揭示耳聋基因的存在、功能及其作用机制的.     

转基因及基因打靶技术在耳科学中的应用

转基因(transgene)和基因打靶(gene targeting)技术通过基因的加入或删除建立了大量小鼠模型,尤其是条件性基因敲除为避免小鼠突变体在胚胎期死亡提供了条件.本文主要以参与听觉机械转导、表达于盖膜和纤毛束上的基因及其小鼠模型为例,讨论该技术是如何揭示耳聋基因的存在、功能及其作用机制的.     

A prospective study of dietary folate intake and risk of colorectal cancer: modification by caffeine intake and cigarette smoking.

Epidemiologic evidence indicates an inverse association of folate intake with risk of colorectal cancer, but whether this association is modified by intake of caffeine (in coffee and tea) or cigarette smoking--factors that possibly interfere with folate--has not been studied. Thus, we examined whether the association between dietary folate intake and incidence of colorectal cancer is modified by caffeine intake and smoking. Cox proportional hazards modeling was used to estimate rate ratios relating dietary folate intake to colorectal cancer incidence among 61,433 women ages 40 to 75 years at recruitment into the Swedish Mammography Cohort in 1987 to 1990. From March 1987 through June 2004, a total of 805 incident cases of colorectal cancer were diagnosed. After controlling for age and other potential confounders, we observed an inverse association between dietary folate intake and risk of colon cancer (rate ratio for the highest versus the lowest quintile, 0.61; 95% confidence interval, 0.41-0.91; P(trend) = 0.02), but not of rectal cancer (rate ratio, 0.93; 95% confidence interval, 0.55-1.56; P(trend) = 0.97). The inverse association between dietary folate intake and colon cancer risk was most pronounced among smokers (P(interaction) = 0.03). We found no apparent modification of risk by caffeine intake. Findings from this population-based cohort study support an inverse association between dietary folate intake and risk of colon cancer and suggest that smokers might benefit most from a high dietary folate intake.     

Patient-Specific Modeling of Stented Coronary Arteries Reconstructed from Optical Coherence Tomography: Towards a Widespread Clinical Use of Fluid Dynamics Analyses

The recent widespread application of optical coherence tomography (OCT) in interventional cardiology has improved patient-specific modeling of stented coronary arteries for the investigation of local hemodynamics. In this review, the workflow for the creation of fluid dynamics models of stented coronary arteries from OCT images is presented. The algorithms for lumen contours and stent strut detection from OCT as well as the reconstruction methods of stented geometries are discussed. Furthermore, the state of the art of studies that investigate the hemodynamics of OCT-based stented coronary artery geometries is reported. Although those studies analyzed few patient-specific cases, the application of the current reconstruction methods of stented geometries to large populations is possible. However, the improvement of these methods and the reduction of the time needed for the entire modeling process are crucial for a widespread clinical use of the OCT-based models and future in silico clinical trials.