Outcomes of endoscopic submucosal dissection for colorectal neoplasms: Prospective, multicenter, cohort trial.

OBJECTIVES: Endoscopic mucosal resection (EMR) is the gold standard for the treatment of noninvasive large colorectal lesions, despite challenges associated with nonlifting lesions and a high rate of local recurrence. Endoscopic submucosal dissection (ESD) offers the possibility of overcoming these EMR limitations. However, a higher risk of complications and longer procedure time prevented its dissemination. As ESD now provides more stable results because of standardized techniques compared with those used earlier, this study aimed to quantify the rates of en bloc and curative resections, as well as ESD complications, in the present situation. METHODS: A multicenter, large-scale, prospective cohort trial of ESD was conducted at 20 institutions in Japan. Consecutive patients scheduled for ESD were enrolled from February 2013 to January 2015. RESULTS: ESD was performed for 1883 patients (1965 lesions). The mean procedure time was 80.6 min; en bloc and curative resections were achieved in 1759 (97.0%) and 1640 (90.4%) lesions, respectively, in epithelial lesions ≥20 mm. Intra- and postprocedural perforations occurred in 51 (2.6%) and 12 (0.6%) lesions, respectively, and emergency surgery for adverse events was performed in nine patients (0.5%). CONCLUSIONS: This trial conducted after the standardization of the ESD technique throughout Japan revealed a higher curability, shorter procedure time, and lower risk of complications than those reported previously. Considering that the target lesions of ESD are more advanced than those of EMR, ESD can be a first-line treatment for large colorectal lesions with acceptable risk and procedure time. (Clinical Trial Registration: UMIN000010136).

Effects of chloromethanes on growth of and deletion of the pce gene cluster in dehalorespiring Desulfitobacterium hafniense strain Y51.

The dehalorespiring Desulfitobacterium hafniense strain Y51 efficiently dechlorinates tetrachloroethene (PCE) to cis-1,2-dichloroethene (cis-DCE) via trichloroethene by PceA reductive dehalogenase encoded by the pceA gene. In a previous study, we found that the significant growth inhibition of strain Y51 occurred in the presence of commercial cis-DCE. In this study, it turned out that the growth inhibition was caused by chloroform (CF) contamination of cis-DCE. Interestingly, CF did not affect the growth of PCE-nondechlorinating SD (small deletion) and LD (large deletion) variants, where the former fails to transcribe the pceABC genes caused by a deletion of the promoter and the latter lost the entire pceABCT gene cluster. Therefore, PCE-nondechlorinating variants, mostly LD variant, became predominant, and dechlorination activity was significantly reduced in the presence of CF. Moreover, such a growth inhibitory effect was also observed in the presence of carbon tetrachloride at 1 microM, but not carbon dichloride even at 1 mM.