Endoscopic submucosal dissection using a new scissors-type electrosurgical knife: a first-in-human feasibility study.

BACKGROUND AND STUDY AIMS: Endoscopic submucosal dissection (ESD) is more difficult and has a higher rate of complications, such as perforation and bleeding, compared with conventional endoscopic resection. The aim of this study was to evaluate the feasibility of a new scissors-type electrosurgical knife for ESD, which was developed for improved durability and ease of use. MATERIALS AND METHODS: Initial ex vivo experiments and subsequent ESD procedures in live pigs were carried out. A human feasibility study was then performed in patients with early esophageal or gastric cancer. The primary end point was serious adverse events (SAE) related to ESD. RESULTS: In the ex vivo and live animal models, no mechanical errors occurred and only minor damage to surrounding tissue was observed. Four patients were enrolled in the human feasibility study; all ESD procedures were completed with a mean procedure time of 31 minutes. All specimens were resected completely without any SAEs. The device worked smoothly, with no electrical problems noted. CONCLUSION: ESD using a novel scissors-type knife for early esophageal or gastric cancer is feasible. CLINICAL TRIAL REGISTRATION: UMIN000004941.

Ursodeoxycholic acid inhibits overexpression of P-glycoprotein induced by doxorubicin in HepG2 cells.

The hepatoprotective action of ursodeoxycholic acid (UDCA) was previously suggested to be partially dependent on its antioxidative effect. Doxorubicin (DOX) and reactive oxygen species have also been implicated in the overexpression of P-glycoprotein (P-gp), which is encoded by the MDR1 gene and causes antitumor multidrug resistance. In the present study, we assessed the effects of UDCA on the expression of MDR1 mRNA, P-gp, and intracellular reactive oxygen species levels in DOX-treated HepG2 cells and compared them to those of other bile acids. DOX-induced increases in reactive oxygen species levels and the expression of MDR1 mRNA were inhibited by N-acetylcysteine, an antioxidant, and the DOX-induced increase in reactive oxygen species levels and DOX-induced overexpression of MDR1 mRNA and P-gp were inhibited by UDCA. Cells treated with UDCA showed improved rhodamine 123 uptake, which was decreased in cells treated with DOX alone. Moreover, cells exposed to DOX for 24h combined with UDCA accumulated more DOX than that of cells treated with DOX alone. Thus, UDCA may have inhibited the overexpression of P-gp by suppressing DOX-induced reactive oxygen species production. Chenodeoxycholic acid (CDCA) also exhibited these effects, whereas deoxycholic acid and litocholic acid were ineffective. In conclusion, UDCA and CDCA had an inhibitory effect on the induction of P-gp expression and reactive oxygen species by DOX in HepG2 cells. The administration of UDCA may be beneficial due to its ability to prevent the overexpression of reactive oxygen species and acquisition of multidrug resistance in hepatocellular carcinoma cells.

A single exposure of rats to water-immersion restraint stress induces oxidative stress more severely in the thymus than in the spleen.

OBJECTIVES: We examined whether a single exposure of rats to water-immersion restraint stress (WIRS) induces oxidative stress in the thymus and spleen. METHODS: Vitamin E, ascorbic acid, reduced glutathione (GSH), and lipid peroxide (LPO) were assayed in the thymus and spleen of rats with and without 6 hours of WIRS. RESULTS: In unstressed rats, vitamin E, ascorbic acid, GSH, and LPO levels were higher in the thymus than in the spleen. Thymic ascorbic acid level was lower in stressed rats than in unstressed rats. Splenic ascorbic acid level was similar in both groups. Thymic and splenic GSH levels were lower in stressed rats than in unstressed rats but the reduced amount of GSH was lower in the spleen than in the thymus. Thymic vitamin E level was lower in stressed than in unstressed rats. Splenic vitamin E level was higher in stressed rats than in unstressed rats. Thymic and splenic LPO levels were higher in stressed rats than in unstressed rats but the increased amount of LPO was higher in the thymus than in the spleen. CONCLUSION: It is indicated that a single expose of rats to WIRS induces oxidative stress more severely in the thymus than in the spleen.