Objective To express and purify recombinant and biologically active Clostridium difficile toxin B (rTcdB). Methods The genes of TcdB were amplified by polymerase chain reaction (PCR) using chromosomal DNA from a toxigenic strain, and cloned into a shuttle vector pHis1522.The sequences of TcdB genes in the vector were verified by DNA sequencing. The construction was transformed into Bacillus megaterium protoplasts and the protein expression was driven by a xylose promoter. The purified protein was tested for biological activity. Results rTcdB was successfully purified from bacterial crude extracts. Approximately 5-10 mg of highly purified recombinant toxin was obtained from one liter of bacterial culture. The expressed rTcdB had molecular mass similar to the native toxin, and its biological activity was proved to be similar to its native counterpart after an extensive examination. Conclusion rTcdB with biological activities is successfully expressed in Bacillus megaterium.

The purpose was to investigate the research achievements over the past two decades on moxa smoke produced in the process of moxibustion, in terms of its clinical studies, chemical compositions, safety assessment as well as the mild smoke or smoke-free moxibustion, for revealing the recent dynamic and developing orientation, and promoting its further application, succession and innovation.

Objective To compare the long term effectiveness of tonsillotomy(TT)vs. tonsillectomy (TE)by hypercator in treatment of obstructive sleep apnea hypopnea syndrome(OSAHS)in children. Methods 119 children with tonsil hypertrophy were diagnosed with OSAHS and included in the study. Among them,57 children underwent TT by hypercator and 62 TE only after preoperative laboratory polysomnography(PSG). All participants were interviewed 5 years after operation to assess the satisfaction of their caregivers,investigate the frequency of respiratory infections,the rate of tonsil regrowth and evaluate their quality of life by Obstructive Sleep Apnea-18(OSA-18). Results Some of them received postoperative PSG. All parents reported alleviation of breathing obstruction,but the postoperative satisfaction in TT group was higher than TE group mainly because of the shorter time return to normal diet. The rate of the respiratory tract infections was not increased in all cases after surgery. Four cases of children were observed with tonsillar regrowth,but no surgery was needed for further treatment. The rate of the dry throat symptoms in TT group was lower than TE group. Conclusions Tonsillotomy by hypercator can effectively eliminate the obstruction symptoms in children with OSAHS,superior to TE for its shorter recovery period and smaller oral mucosal injury and lower rate of tonsils regrowth and it is worth to clinical promotion.