To examine the effect of melatonin on in vitro fertilization and embryonic development, mouse embryos after insemination in vitro were cultured in a physiological medium with or without melatonin. Melatonin increased the fertilization rate significantly at a concentration between 10(-6) and 10(-4) M (27.6 vs. 43.9 or 40.4%, P < 0.01). Furthermore, a significant increase in the rate of embryos reaching the four-cell stage (16.0 vs. 26.7%, P < 0.01), the eight-cell stage (12.1 vs. 25.8 or 23.5%, P < 0.01), and blastulation (8.9 vs. 23.5 or 17.5%, P < 0.01) was observed when the embryos were cultured in a medium containing 10(-8) or 10(-6) M melatonin. These results demonstrate that melatonin supports fertilization and early embryo development after in vitro fertilization.

Background: Endoscopic submucosal resection (ESD) and endoscopic mucosal resection (EMR) are well established as curable and safety procedures for treating superficial tumors of the stomach, esophagus and colon. However, a majority of endoscopic resection strategies for non-ampullary superficial duodenal tumors (NASDTs) remains undefined. The aim of this study was to clarify which was the right method for NASDT treatment - EMR or ESD. Summary: We analyzed 129 consecutive endoscopic resection (74 ESD and 55 EMR) procedures performed with NADSTs and divided the ESD group into 49 large ESD groups (more than 20 mm in diameter) and 25 small ESD groups (less than 20 mm in diameter). With respect to the technical outcomes of EMR/ESD for small size NASDTs, EMR was safer than ESD, but its nature of curability was inferior to that of ESD. The rates of complication such as perforation or delayed bleeding were significantly higher in both ESD groups than in the EMR group. However, the prophylactic endoscopic closure of large mucosal defects after ESD was useful for resolving those complications. The limitations of our study were involvement of a single-center, limited sample size, short follow-up duration and the retrospective design, which may have introduced selection bias. However, the present findings suggest that adequate endoscopic treatment strategy for NASDTs can lead to favorable outcomes and an excellent prognosis. Key Message: It is necessary to select EMR or ESD adequately for R0 resection of small NASDTs, according to their size and location. For large NASDTs, duodenal ESD with essential management is feasible and useful as a therapeutic procedure.

The presence of melatonin (N-acetyl-5-methoxytryptamine) and its precursors, serotonin (5-hydroxytryptamine) and N-acetylserotonin, was demonstrated in extracts of human ovary using reverse-phase highperformance liquid chromatography coupled with fluorometric detection. In addition, activities of two melatonin-synthesizing enzymes, arylalkylamine N-acetyltransferase (NAT) and hydroxyindole-O-methyltransferase (HIOMT), were found in human ovary homogenates. The apparent Michaelis constants for the substrates of NAT and HIOMT in the human ovary were similar to those reported for the pineal glands of humans and other mammals. These findings strongly suggest that the human ovary, like the pineal gland, may synthesize melatonin from serotonin by the sequential action of NAT and HIOMT.

This retrospective evaluation found that endoscopic closure was associated with a reduced risk of delayed bleeding after duodenal ESD. Delayed bleeding after duodenal ESD might be prevented by prophylactic endoscopic closure.

Background and study aims: The clinical benefit of endoscopic submucosal dissection (ESD) for superficial duodenal neoplasias has not yet been verified. The aims of this study were to validate the feasibility and long-term outcomes of ESD for nonampullary superficial duodenal neoplasias, larger than 20 mm. Patients and methods: 41 patients, with 41 nonampullary large superficial duodenal neoplasias, who underwent ESD between April 2005 to March 2013 were included in the study. The short- and long-term outcomes were retrospectively evaluated, related to tumor size, resection size, histological type, invasion depth, complete resection rate, operation time, perforation rate, delayed bleeding rate, local recurrence rate, distant metastasis, and survival rate. Results: ESD was successfully completed in 38 of 41 patients (92.7 %). The median sizes of tumors and resected specimens were, respectively, 26 mm (range 20 – 70 mm) and 36.5 mm (range 23 – 80 mm). Histopathological findings showed 13 adenocarcinomas (12 mucosal, 1 submucosal) and 28 adenomas (26 high grade dysplasia, 2 low grade dysplasia). The complete resection rate was 89.5 % (34 /38 tumors). The mean operation time was 128.3minutes. Perforation during ESD occurred in 39 % and delayed bleeding occurred in 18.4 %. The median observation period was 48 months (range 3.2 – 94.1 months), and no local recurrence or distant metastasis was seen during this time, representing a disease-free survival rate of 100 %. Conclusions: ESD for nonampullary large superficial duodenal adenocarcinoma/adenoma is feasible with favorable long-term outcomes. However, because of the high complication rate due to its technical difficulty, experience and skill of the operator, along with adequate perioperative management, are essential.