Ultra-stable performance of an underground-based laser interferometer observatory for gravitational waves

In order to detect the rare astrophysical events that generate gravitational wave (GW) radiation, sufficient stability is required for GW antennas to allow long-term observation. In practice, seismic excitation is one of the most common disturbances effecting stable operation of suspended-mirror laser interferometers. A straightforward means to allow more stable operation is therefore to locate the antenna, the ``observatory'', at a ``quiet'' site. A laser interferometer gravitational wave antenna with a baseline length of 20m (LISM) was developed at a site 1000m underground, near Kamioka, Japan. This project was a unique demonstration of a prototype laser interferometer for gravitational wave observation located underground. The extremely stable environment is the prime motivation for going underground. In this paper, the demonstrated ultra-stable operation of the interferometer and a well-maintained antenna sensitivity are reported.Comment: 8 pages, to appear on PR

Operative Procedure for Laparoscopy-Assisted Vagus Nerve and Pylorus-Preserving Gastrectomy (LAVNPPG) for Early Gastric Cancer

Laparosocpy-assisted pylorus-preserving gastrectomy (LAPPG) is a widely accepted surgical procedure for the treatment of early gastric cancer in the middle third of the stomach. We have been performing this operation since 2007. Compared with traditional distal gastrectomy, LAPPG has postoperative nutritional benefits for patients. However, this procedure preserves only the pyloric branch of the vagus nerve and not the celiac branch. We found that patients retain a large amount of residual food in the gastric remnant, which interferes with the detection of secondary cancer on endoscopic follow-up. To improve the pyloric function and postoperative gastrointestinal motility, we changed our procedure during 2009 to preserve both the pyloric and celiac branches of the vagus nerve, and we named this new procedure laparoscopy-assisted vagus nerve and pylorus-preserving gastrectomy (LAVNPPG). From 2009 to 2011, 11 patients underwent LAVNPPG at our hospital. Retrospective comparison of the safety of operation, postoperative complications, and condition of the gastric remnant between LAPPG (n = 13) and LAVNPPG (n = 11) found that the occurrence of postprandial stasis and food residue in the gastric remnant tended to be lower following LAVNPPG, though the differences were not significant. These findings indicate that LAVNPPG may be an operative procedure that could replace LAPPG

Gross Appearance and Curability Are Predictive Factors of a Better Prognosis After Gastrectomy in Gastric Cancer Patients with Metastasis to the Adjacent Peritoneum of the Stomach

[Background] Gastric cancer patients with peritoneal metastasis have an extremely poor prognosis. The aim of the current study was to clarify the predictive factors of a better outcome in gastric cancer patients with peritoneal metastasis. [Methods] We analyzed the records of 2262 gastric adenocarcinoma patients who underwent gastrectomies at our institution between January 1980 and December 2010. [Results] The 5-year survival rates for advanced gastric cancer patients with P1 (n = 43), P2 (n = 56), and P3 (n = 36) metastasis were 16.3%, 0%, and 0%, respectively. The prognosis of P1 gastric cancer patients was significantly better than that of either P2 (P = 0.0003) or P3 patients (P < 0.0001). A multivariate analysis identified gross appearance and curability as independent prognostic indicators in P1 gastric cancer patients. In fact, the prognosis was good for patients in whom an R0/1 resection had been performed and with tumors having a gross appearance of other than type 4, with a 40% 5-year survival rate and a 29-month median survival time. [Conclusion] Our data indicated a good prognosis for P1 patients in whom an R0/1 resection could be performed and with tumors having a gross appearance of other than type 4. Therefore, radical surgery and adequate adjuvant chemotherapy should be performed in these patients

Glucotoxicity Induces Insulin Promoter DNA Methylation in Beta Cells

Recent studies have implicated epigenetics in the pathophysiology of diabetes. Furthermore, DNA methylation, which irreversibly deactivates gene transcription, of the insulin promoter, particularly the cAMP response element, is increased in diabetes patients. However, the underlying mechanism remains unclear. We aimed to investigate insulin promoter DNA methylation in an over-nutrition state. INS-1 cells, the rat pancreatic beta cell line, were cultured under normal-culture-glucose (11.2 mmol/l) or experimental-high-glucose (22.4 mmol/l) conditions for 14 days, with or without 0.4 mmol/l palmitate. DNA methylation of the rat insulin 1 gene (Ins1) promoter was investigated using bisulfite sequencing and pyrosequencing analysis. Experimental-high-glucose conditions significantly suppressed insulin mRNA and increased DNA methylation at all five CpG sites within the Ins1 promoter, including the cAMP response element, in a time-dependent and glucose concentration-dependent manner. DNA methylation under experimental-high-glucose conditions was unique to the Ins1 promoter; however, palmitate did not affect DNA methylation. Artificial methylation of Ins1 promoter significantly suppressed promoter-driven luciferase activity, and a DNA methylation inhibitor significantly improved insulin mRNA suppression by experimental-high-glucose conditions. Experimental-high-glucose conditions significantly increased DNA methyltransferase activity and decreased ten-eleven-translocation methylcytosine dioxygenase activity. Oxidative stress and endoplasmic reticulum stress did not affect DNA methylation of the Ins1 promoter. High glucose but not palmitate increased ectopic triacylglycerol accumulation parallel to DNA methylation. Metformin upregulated insulin gene expression and suppressed DNA methylation and ectopic triacylglycerol accumulation. Finally, DNA methylation of the Ins1 promoter increased in isolated islets from Zucker diabetic fatty rats. This study helps to clarify the effect of an over-nutrition state on DNA methylation of the Ins1 promoter in pancreatic beta cells. It provides new insights into the irreversible pathophysiology of diabetes