Objective: To study the related factors of radiation induced lung injury(RILI) after three-dimensional conformal radiotherapy(3D-CRT) in the elderly patients with advance esophageal cancer, thus to provide reference for radiotherapy planning. Methods: The clinical data and physical parameters of 72 elderly patients with advance esophageal cancer were analyzed, including gender, age, performance status scoring, smoking history, tumor location, T staging, underlying disease of the lung, radiation dose, the whole lung accepted 5 Gy exposure volume(V5), V10, V15, V20, V25, V30, V40 and mean lung dose(MLD). Results: Among 72 patients, 15 cases developed RILI.It was revealed by univariate analysis that there were statistically significant differences in advanced age, underlying disease of the lung, V5, V10, V15, V20, V25, MLD with RILI(χ²=5.098, P=0.026; χ²=3.598, P=0.030; t=3.854, P=0.034; t=4.901, P=0.022, t=4.638, P=0.029, t=5.122, P=0.015, t=3.652, P=0.041, t=5.760, P=0.010). Conclusion It should be payed more attention to factors such as advanced age, underlying disease of the lung, V5, V10, V15, V20, V25 and MLD when elderly patients with advance esophageal cancer patients were treated with 3D-CRT in order to prevent and decrease the risks of RILI.

Development of controllable hypermutable cells can greatly benefit understanding and harnessing microbial evolution. However, there have not been any similar systems developed for Clostridium, an important bacterial genus. Here we report a novel two-step strategy for developing controllable hypermutable cells of Clostridium acetobutylicum, an important and representative industrial strain. Firstly, the mutS/L operon essential for methyldirected mismatch repair (MMR) activity was inactivated from the genome of C. acetobutylicum to generate hypermutable cells with over 250-fold increased mutation rates. Secondly, a proofreading control system carrying an inducibly expressed mutS/L operon was constructed. The hypermutable cells and the proofreading control system were integrated to form a controllable hypermutable system SMBMutC, of which the mutation rates can be regulated by the concentration of anhydrotetracycline (aTc). Duplication of the miniPthl-tetR module of the proofreading control system further significantly expanded the regulatory space of the mutation rates, demonstrating hypermutable Clostridium cells with controllable mutation rates are generated. The developed C. acetobutylicum strain SMBMutC2 showed higher survival capacities than the control strain facing butanol-stress, indicating greatly increased evolvability and adaptability of the controllable hypermutable cells under environmental challenges.
Butanols ; pharmacology ; Cell Engineering ; methods ; Clostridium acetobutylicum ; cytology ; drug effects ; genetics ; physiology ; DNA Methylation ; genetics ; DNA Mismatch Repair ; genetics ; Evolution, Molecular ; Genome, Bacterial ; genetics ; MutS DNA Mismatch-Binding Protein ; genetics ; Mutation ; Operon ; genetics ; Stress, Physiological ; drug effects ; genetics