Efficacy of early clip-with-line method for colorectal endoscopic submucosal dissection.

BACKGROUND: Colorectal endoscopic submucosal dissection (ESD) remains demanding due to technical difficulties and high risk of perforation. Most of the reported traction methods are initiated after creating a mucosal flap, which is time consuming. To obtain a good visualization at the mucosal incision stage, we developed the early clip-with-line (ECL) method. This method was started immediately after injection of sodium hyaluronate solution into the submucosal layer. In this study, we evaluated the efficacy and the safety of the ECL method for colorectal ESD. METHODS: We retrospectively analyzed all cases of colorectal ESDs (41 cases in total) performed from January 2017 to February 2019 in our institution. From January 2017 to August 2018, 27 of these cases were performed using conventional (non-ECL) ESDs, while from September 2018 onwards, the remaining 14 cases were performed using the ECL method. Retrospective comparison between the ECL group and the non-ECL group was conducted in terms of clinical characteristics, treatment outcomes, and adverse events. RESULTS: There were no significant differences in clinical characteristics between two groups. Procedure time (median [range]) was significantly shorter in the ECL group than in the non-ECL group (66 [29-131] min vs 90 [30-410] min; P = 0.03). As for adverse events, no case of perforation occurred in the ECL group, whereas perforation was observed in 7.4% (2/27) cases in the non-ECL group (no significant difference). CONCLUSION: Early clip-with-line method for colorectal endoscopic submucosal dissection reduced procedure time.

[A case of recurrent transverse colon cancer invading the pancreas and duodenum successfully treated with biliary and duodenal stenting].

We report a case of recurrent transverse colon cancer invading the pancreas and duodenum that was successfully treated with biliary and duodenal stenting. A 46-year-old man underwent ascending colostomy for the treatment of obstructive transverse colon cancer with hepatic metastasis. Chemotherapy achieved a partial response, but the levels of tumor markers later began to rise again. He then underwent right hemicolectomy and partial hepatectomy. Post-operative chemotherapy was administered, but the recurrent tumor caused obstructive jaundice and duodenal obstruction. These were successfully treated with biliary and duodenal stenting, and the patient was able to remain at home and maintain his quality of life.

Characterization of cysteine protease induced by oxidative stress in cells of Chlamydomonas sp. strain W80.

Unlike known Chlamydomonas species, Chlamydomonas sp. strain W80, which was isolated from seawater, shows tolerance to salt and cadmium. In this study, we purified and characterized cysteine protease from Chlamydomonas sp. strain W80 cells and also investigated their response to oxidative stress. The protease was purified 2760-fold with a yield of 2.6% by five steps of successive chromatography. This protease had a pH optimum of 8.0 and was specific only for tert-butoxycarbonyl (Boc)-Leu-Arg-Arg-4-methylcoumaryl-7-amide (MCA) (Boc-LRR-MCA) and Boc-Val-Leu-Lys-MCA as substrates among eight fluorogenic peptides tested. The K(m) value was estimated to be 44.4 microM for Boc-LRR-MCA. The molecular weight of the protease was determined to be approximately 102 kDa by Superdex 200 gel filtration and 60 kDa by SDS-PAGE, suggesting that this enzyme is a dimer. This enzyme was inhibited by the cysteine protease inhibitors leupeptin and N-ethylmaleimide but neither inhibited by phenylmethylsulfonyl fluoride or ethylenediaminetetraacetic acid nor activated by metal cations. These findings indicate that this enzyme is likely a cysteine protease. When strain W80 was grown under oxidative stress in the presence of methyl viologen and cadmium chloride, cysteine protease activity was about 30-90% higher than normal, whereas no changes were observed in carbon enrichment or senescence. It is likely that this protease is upregulated in response to oxidative stress and plays a role in the maintenance of cell metabolism under oxidative stress conditions.