Publications by authors named "Akira Nakahara"

Collagenous gastritis (CG) is a rare disorder characterized by the thick collagenous subepithelial bands associated with mucosal inflammation. There have been approximately fifty reports in the literature since it was first described in 1989. According to previous reports, CG is heterogeneous and classified into two groups-(1) cases limited to the gastric mucosa in children or young adults, and (2) CG associated with collagenous colitis in elderly adults presenting with chronic watery diarrhea.

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Purpose: To evaluate the efficacy and safety of hyperfractionated concomitant boost proton beam therapy (PBT) for patients with esophageal cancer.

Methods And Materials: The study participants were 19 patients with esophageal cancer who were treated with hyperfractionated photon therapy and PBT between 1990 and 2007. The median total dose was 78 GyE (range, 70-83 GyE) over a median treatment period of 48 days (range, 38-53 days).

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Real surface structures of the high-index planes of Pt with three atomic rows of terraces (Pt(331) = 3(111)-(111) and Pt(511) = 3(100)-(111)) have been determined in 0.1 M HClO(4) at 0.1 and 0.

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Purpose: To evaluate the efficacy and safety of proton-beam therapy for locoregionally advanced esophageal cancer.

Patients And Methods: The subjects were 51 patients with esophageal cancer who were treated between 1985 and 2005 using proton beams with or without X-rays. All but one had squamous cell carcinoma.

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Oxidative stress is a critical mediator in liver injury of steatohepatitis. The transcription factor Nrf2 serves as a cellular stress sensor and is a key regulator for induction of hepatic detoxification and antioxidative stress systems. The involvement of Nrf2 in defense against the development of steatohepatitis remains unknown.

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Human cystathionine beta-synthase (CBS) is a pyridoxal 5'-phosphate (PLP) dependent hemoprotein, which catalyzes the condensation of serine and homocysteine. Our mutagenesis studies suggest that Arg-266 is important to sense structural changes in heme-binding site, and that Gln-222 as well as Tyr-223 are involved in interactions with substrates.

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Background: Gastric complications of indomethacin involve generation of reactive oxygen species, which induce gastric mucosal injury via lipid peroxidation of cell membranes. Peroxidation by reactive oxygen species alters the amounts of unsaturated fatty acids in the cell membrane and thus affects membrane fluidity. Indomethacin-induced lipid peroxidation can thus be detected by measuring cellular membrane fluidity by the fluorescence polarization (FP) method.

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N-methyl-N'-nitro-N-nitrosoguanidine (MNNG) induces gastric cancer in animal models. We established an MNNG-induced mutant of the rat murine RGM-1 gastric epithelial cell line, which we named RGK-1, that could be used as an in vitro model of gastric cancer. This cell line showed signs of neoplasia and transformation, in that it lost contact inhibition and formed tumors in nude mice.

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Background And Aim: Helicobacter pylori (H. pylori) infection enhances the production of reactive oxygen species and peroxynitrite, thereby resulting in oxidative tissue damage. In this study, we examined the role of peroxiredoxin I (Prx I), a stress-induced antioxidant enzyme, in protecting gastric mucosa from H.

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Surface structure of a stepped surface of Pt, Pt(311) (=2(100)-(111)), has been determined under potential control in 0.1 M HClO4 with the use of in situ surface X-ray scattering (SXS). The crystal truncation rods (CTRs) are reproduced well with the (1x2) missing-row model.

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Background/aim: Geranylgeranylacetone (GGA) enhances gastric mucosal protection against nonsteroidal anti-inflammatory drugs by upregulating mucosal heat shock proteins (HSP), but the effects of GGA on the human gastric mucosa have not been well examined. This study was conducted to determine whether a clinical dose of GGA protects the human gastric mucosa from diclofenac (DIC)-induced gastric mucosal injury.

Methods: The study group comprised 40 healthy volunteers: 20 subjects were randomly assigned to take either placebo (lactose 1.

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Background And Aim: Gastric cancer is associated not only with Helicobacter pylori (H. pylori) infection, but also with the intake of a high salt diet. Interleukin-1beta (IL-1beta) is highly expressed in H.

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Background: Several studies have demonstrated that intratumoral expression of catabolizing and anabolizing enzymes for 5-fluorouracil (5-FU) is important in the response of cancers to 5-FU-based chemotherapy. We investigated the influence of other chemotherapeutic agents or cytokines, which are often administered for enhancing the efficacy of 5-FU, on the tumoral expression of 5-FU-associated enzymes, i.e.

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Background: Intimate cross-talk may take place between intestinal epithelial cells and intraepithelial lymphocytes (IEL). The purpose of this study was to analyze the influence of lymphocyte migration into the epithelium on epithelial function, using an in vitro "IEL homing" model.

Methods: Molecular expression on epithelial cells was analyzed by flow cytometry.

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Nonsteroidal antiinflammatory drugs (NSAIDs) cause complications such as gastrointestinal injury. NSAIDs were recently reported to cause mitochondrial injury: to dissipate the mitochondrial transmembrane potential (MTP), and to induce mitochondrial permeability transition pore (PTP), which liberates cytochrome c. This enzyme generates reactive oxygen species (ROS) thereby triggers caspase cascade and cellular lipid peroxidation, resulting in cellular apoptosis.

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Objective: Endoscopic papillary balloon dilatation (EPBD) has been reported to increase the risk of post-endoscopic retrograde cholangiopancreatography (ERCP) pancreatitis (4%-11%). Based on the hypothesis that performing endoscopic nasobiliary drainage (ENBD) could prevent this complication, we performed EPBD combined with ENBD (EPBD/ENBD) and analyzed the risk of pancreatitis.

Methods: Thirty-four patients underwent EPBD followed by ENBD for common bile duct stone(s).

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Purpose: To present the results of proton beam therapy for patients with esophageal cancer.

Methods And Materials: This study reviewed 46 patients with esophageal cancer who were treated between 1985 and 1998 using proton beams with or without X-rays. All patients had locoregionally confined disease; all but one had squamous cell carcinoma.

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To address the need for new prognostic parameters in advanced colon carcinoma that could add insights into the aggressiveness of tumors, the expression levels of MUC1 recognized by a monoclonal antibody (mAb) MY.1E12 in archival specimens from 123 Japanese patients with colon carcinomas were evaluated by immunohistochemistry to correlate the results with clinicopathological characteristics. The localization of mAb MY.

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Background:  Various types of classification of gastritis have been proposed, but no plausible classification has been available until now. The Research Society for Gastritis performed a pilot study to establish an endoscopic classification, taking into consideration the following: (i) ease of use; (ii) permitting everyone the common image; and (iii) presence of histopathological evidence.

Methods:  One hundred and fifty-five patients were enrolled and underwent gastroscopy.

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Gastric luminal ammonia produced by Helicobacter pylori has been shown to cause gastric mucosal injury. This study was conducted to examine the mechanisms by which gastric luminal ammonia causes apoptosis of gastric epithelial cells. Monolayers of GSM06 cells, developed from murine gastric surface mucous cells, were cultured in the absence or presence of 10-30 mM NH(4)Cl at ambient pH of 5.

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Background: Telomerase, the ribonucleoprotein enzyme that synthesizes telomeric DNA, is thought to be necessary for cellular immortality and carcinogenesis. Telomerase activity is associated with the majority of malignant human cancers. The mRNA that encodes the telomerase catalytic subunit (human telomerase repeat transcriptase; hTERT) has recently been identified, and the expression of the hTERT gene is thought to regulate the activation of telomerase.

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This study was conducted to determine whether the contributions of epidermal growth factor (EGF) to gastric mucosal restitution after injury are mediated by stimulation of Na(+)/H(+) exchangers in surface mucous cells (SMC). Intact sheets of guinea pig gastric mucosae were incubated in vitro. Intracellular pH (pH(i)) in SMC was measured fluorometrically, using 2',7'- bis-(2-carboxyethyl)-5-(and-6)-carboxyfluorescein.

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