Ayumu Taguchi

Endoscopic resection of Peutz-Jeghers polyps throughout the small intestine at double-balloon enteroscopy without laparotomy

BACKGROUND Small-bowel enteroscopy with the double-balloon method was developed to improve access to the small intestine. This study evaluated the usefulness of this method for the resection of small-intestinal Peutz-Jeghers polyps. METHODS Two patients with Peutz-Jeghers syndrome underwent nonsurgical double-balloon enteroscopic resection of polyps throughout the small intestine. OBSERVATIONS Multiple polyps in the jejunum were successfully resected via the oral route, as were the polyps in the ileum via the anal route. All 18 polyps (10-60 mm in size) were resected without subsequent bleeding or perforation. Histopathologically, 3 large polyps (>30 mm diameter) were hamartomas with adenomatous components. CONCLUSIONS Double-balloon enteroscopy was safe and useful for the diagnosis and the treatment of Peutz-Jeghers polyps throughout the small intestine. Double-balloon enteroscopic polypectomy might preclude complications of Peutz-Jeghers syndrome, including intussusception, bleeding, and tumorogenesis, thereby obviating the need for multiple laparotomies.

MDM2 Promoter Polymorphism Is Associated With Both an Increased Susceptibility to Gastric Carcinoma and Poor Prognosis

PURPOSE Recently, a single-nucleotide polymorphism in the MDM2 promoter (SNP309) has been found to lower the age of onset of tumors and increase the occurrence of multiple primary tumors in Li-Fraumeni syndrome, and accelerate the development of sporadic adult soft tissue sarcoma. The aim of this study was to determine whether SNP309 is associated with susceptibility to gastric carcinoma and its prognosis. PATIENTS AND METHODS In a case-control study including 438 controls and 410 patients with sporadic gastric carcinoma, MDM2 SNP309 was genotyped. Serum pepsinogens (PGs) I and II were measured in 438 control subjects and 253 cases selected from 410 patients. Tumor tissue was immunostained with p53 and examined for mutations in exons 5 to 8 of p53 using polymerase chain reaction-based single strand conformational polymorphism analysis and direct sequencing. RESULTS The risk of overall gastric carcinoma for SNP309 (G/G) was significantly increased when compared with T carriers (P = .039), especially carcinomas with extragastric tumors (P = .005), carcinoma with severe atrophic gastritis positive for PG assay (PG I level < 70 ng/mL and PG I/II < 3.0; P = .005), antral carcinoma (P = .020), intestinal-type carcinoma (P = .023), p53-immunopositive carcinoma (P = .007), and carcinoma with p53 mutations (P = .007). No significant difference in age at diagnosis was observed among genotypes. SNP309 (G/G) was an independent marker of poor overall survival in advanced carcinoma (hazard ratio, 3.16; 95% CI, 1.22 to 8.20; P = .018). CONCLUSION This study provides evidence supporting the association of SNP309 with gastric carcinogenesis via p53 tumor suppressor pathway, extragastric tumorigenesis, and poor prognosis.

Small-bowel obstruction: diagnostic comparison between double-balloon endoscopy and fluoroscopic enteroclysis, and the outcome of enteroscopic treatment.

BACKGROUND Small-bowel obstruction (SBO) sometimes remains undiagnosed and untreatable without surgery. OBJECTIVE To evaluate the diagnostic yields of SBO between double-balloon endoscopy (DBE) and fluoroscopic enteroclysis (FE), and the outcome of enteroscopic treatment. DESIGN Single-center, retrospective, and prospective study. SETTING Tertiary-referral hospital. PATIENTS Between June 2003 and July 2007, 66 consecutive patients with SBO were enrolled, investigated, and treated. MAIN OUTCOME MEASUREMENTS A comparison of diagnostic yields between DBE and FE, and the prognosis after enteroscopic balloon dilation. RESULTS The diagnostic yield of DBE for SBO (95%) was higher than that of FE (71%) in 59 patients who underwent both examinations (P= .004). The first treatment included 27 surgical, 25 enteroscopic, and 14 conservative therapies. Of 47 enteroscopic balloon dilation procedures in 22 patients, 45 (96%) were successful. Of 16 patients with Crohns disease, 11 (69%) remained asymptomatic over the postdilation follow-up period but 5 relapsed: 2 recovered by repeated dilations, but 3 required surgery. Of 6 patients who had diseases other than Crohns disease, 4 (67%) remained asymptomatic but 2 relapsed: one with remission of metastasis recovered by repeated dilations, and one with ischemic enteritis required surgery. Anastomotic stricture was an independent marker of the symptom-free outcome (hazard ratio 0.037-0.084, P= .037). Two acute pancreatitis, one perforation, and one exacerbation of SBO complications occurred. LIMITATIONS Small sample size and participation bias. CONCLUSIONS DBE was useful for the diagnosis of SBO. Balloon dilation is considered an alternative to surgery in patients with fibrotic strictures both related and unrelated to Crohns disease.

High-performance blazed GxLTM device for large-area laser projector

A blazed GxL device is described that has high optical efficiency (>70% for RGB lasers), and high contrast ratio (> 10,000:1), and that is highly reliable when used in a large-area laser projection system. The key features were a robust design and precise stress control technology to maintain a uniform shape (bow and tilt) of more than 6,000 ribbons, a 0.25-μm CMOS compatible fabrication processing and planarization techniques to reduce fluctuation of the ribbons, and a reliable Al-Cu reflective film that provided protection against a high-power laser. No degradation in characteristics of the GxL device was observed after operating a 5,000- lumen projector for 2,000 hours and conducting 2,000 temperature cycling tests at -20°C and +80°C. Consequently, the worlds largest laser projection screen with a size of 2005 inches (10 m × 50 m) and 6 million pixels (1,080 × 5,760) was demonstrated at the 2005 World Exposition in Aichi, Japan.

Rugal hyperplastic gastritis increases the risk of gastric carcinoma, especially diffuse and p53-independent subtypes

Objectives Infection with Helicobacter pylori has been linked to chronic gastritis with atrophy or hyperrugosity. The development of noncardia gastric carcinoma, especially the intestinal type in Laurens classification, has been associated with severe atrophic gastritis and p53 mutations. The objective of this study was to determine the association between hyperrugosity and gastric carcinogenesis, including p53 mutations. Participants and methods Barium meal roentgenograms were performed in 395 control participants and 132 gastric carcinoma patients. The fold width was measured at the greater curvature of the middle portion of the gastric body. Serum pepsinogens I and II were determined along with gastrin levels. Complete coding sequences and splice junctions for exons 5–8 of p53 gene were screened for mutations by polymerase chain reaction-based single-strand conformational polymorphism analysis. Results Rugal hyperplastic gastritis (gastric body fold width≥5 mm) increased the risk of gastric carcinoma [odds ratio, 2.60; 95% confidence interval, 1.69–4.01] as compared with the control group, especially diffuse-type gastric carcinoma (odds ratio, 4.13; 95% confidence interval, 2.36–7.24). The p53 mutational rate was significantly lower in gastric carcinoma patients with rugal hyperplastic gastritis. In intestinal-type gastric carcinoma with hyperrugosity, the incidence of p53 gene mutations decreased, but no association was found in diffuse-type gastric carcinoma between p53 mutations and rugal hyperplastic gastritis. Conclusions Rugal hyperplastic gastritis was associated with an elevated risk of gastric carcinoma, especially diffuse-type, and a lower frequency of p53 mutations.

Grating Light Valve Projector

We discuss a grating light valve (GLV) projector has ultra wide potential dynamic range in light intensity modulation only limited by the thermally excited random fluctuation of its membrane displacement

Ultra High Contrast GxL TM Device for Laser Projector

This paper presents a GxL device that exhibits an extremely high contrast ratio. We achieved a very high device contrast ratio of 34700 by optimizing the design of the posts that support the ribbons and flattening the sacrificial layer. By miniaturizing the chip and improving the packaging, we were able to shrink the GxL module by 75%. Dramatic image quality improvement of the GxL projector system was confirmed. No degradation of the GxL device was observed after a temperature cycling test.

Nanometer-Order Control of MEMS Ribbons for Blazed Grating Light Valves

The performance of grating light valve (GLV™) chips can be increased by optimizing their ribbon structures [ 1]. A GLV is a one-dimensional light modulator using diffraction that can be applied to a high definition display by scanning the second dimension. We applied blazed GLV, which diffracts in only one direction [ 2], and achieved a jump in contrast from 3000:1 to 10000:1. Moreover, we achieved a 55 to 70% improvement in optical efficiency due to nanometer-order control of blazed GLV ribbon. These technologies were applied to the 2005-inch theater system “ GxL™ Laser Dream Theater” [ 3, 4].

Sub-nm order fluctuation control of narrowed pitch 2K-GxL™ device for high contrast

We developed a novel 2K vertical resolution device, the 2K-GxL device, for a super real projector, which enabled ribbon pitch to be miniaturized and the contrast ratio to be high simultaneously. Shrinking the ribbon pitch from 4.25 µm from that of previous 1K-GxL device to 3.00 µm was done by introducing a tapered structure to the step region. A high device contrast ratio of 77000 was achieved by suppressing the fluctuation of ribbon height to under 0.32 nm by using the KrF lithography, and also developing a super flattened mirror.

Blazed GxL™ device for laser dream theatre at the Aichi expo 2005

Abstract A blazed GxL™ device is described as having high optical efficiency (> 70% for RGB lasers), and high contrast ratio (> 10,000:1), and that is highly reliable when used in a large‐area laser projection system. It has a robust design and precise stress control technology to maintain a uniform shape (bow and tilt) of more than 6,000 ribbons, a 0.25‐μm CMOS compatible fabrication processing and planarization techniques to reduce fluctuation of the ribbons, and a reliable Al‐Cu reflective film that provided protection against a high‐power laser. No degradation in characteristics of the GxL device is observed after operating a 5,000‐ lumen projector for 2,000 hours and conducting 2,000 temperature cycling tests at ‐20°C and +80°C. At the 2005 World Exposition in Aichi, Japan the worlds largest laser projection screen with a size of 2005 inches (10 m × 50 m) and 6 million pixels (1,080 × 5,760) was demonstrated.