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Background: In humans, high concentrations of nitric oxide are generated luminally at the gastro- oesophageal junction through enterosalivary recirculation of dietary nitrate. Aim: To investigate whether luminal nitric oxide can diffuse into the adjacent digestive tissue and alter tissue integrity. Methods: We designed an animal model using Wistar rats in which physiological concentrations of nitrite and acidified ascorbic acid were administered separately so that the two reactants first meet to form nitric oxide at the gastro-oesophageal junction. Luminal and tissue concentrations of nitric oxide were measured with an electrode and an electron paramagnetic resonance spectrometer, respectively. Concentrations of glutathione in the tissue were measured as a marker of nitrosative stress. n; Results: High concentrations of luminal nitric oxide were generated locally at the gastro-oesophageal junction of nitrite administered rats, reproducing a phenomenon observed in humans. High levels of nitric oxide were also detected largely in the superficial epithelium of the gastro-oesophageal junction. The concentration of I tissue glutathione at the gastro-oesophageal junction was significantly lower in nitrite administered rats compared with control rats, whereas that in the distal stomach was similar in the two rat groups. Conclusions: Using an animal model, this study demonstrated that nitric oxide generated in the lumen diffuses into the adjacent gastric tissue to a substantial degree, leading to localised consumption of glutathione in the tissue. Nitrosative stress induced by this mechanism may be involved in the high prevalence of inflammation and metaplasia, and subsequent development of neoplastic disease at this site. [ABSTRACT FROM AUTHOR]

Background: Helicobacter pylon infection is associated with variable clinical outcomes, including gastroduodenal diseases, and genetic factors may be relevant in this process. Aims: We investigated the effects of an interleukin 8 (11-8) gene polymorphism on the risk of gastroduodenal diseases, the degree of H pylon induced gastritis, and IL-8 gene transcription. Subjects: The study was performed in 244 healthy control subjects and 690 H pylon positive patients with non-cardia gastric cancer, gastric ulcer, duodenal ulcer, or gastritis. Methods: We identified the 1L-8 -251 A/T polymorphism by direct sequence analysis, and measured the gastritis score and serum pepsinogen (PG). The transcriptional promoter activity of the IL-8 gene was assessed by luciferase assay. Results: IL-8 -251 A was associated with a higher risk of gastric cancer and gastric ulcer. Patients carrying IL-8 -251A showed an increased risk of gastric cancer (odds ratios (OR) 2.01 (95% confidence interval (CI) 1.38-2.92)) and gastric ulcer (OR 2.07(95% CI 1.37-3.12)). Compared with patients younger than 49 years, atrophy and metaplasia scores in the antrum were significantly higher and the PG I/II ratio significantly lower in -251A carriers than in T/T carriers. In the in vitro assay, IL-B -251 A showed enhanced promoter activity in response to IL-1β or tumour necrosis factor α. Conclusions: The IL-8 -251A allele may be associated with progression of gastric atrophy in patients with H pylon infection, and may increase the risk of gastric cancer and gastric ulcer in Japanese people. [ABSTRACT FROM AUTHOR]

We demonstrate broadband amplification over (C + L)-band or extended L-band using fusion-spliceable Bi2O3-based erbium doped fiber (EDF). A power conversion efficiency (PCE) of 39% is achieved. In a single-stage amplifier we achieved a 3 dB bandwidth of 75 nm. In addition we showed very low four-wave mixing in an extended L-band amplifier by reducing the length of fiber required to a few meters. [Copyright &y& Elsevier]

BACKGROUND: In Japan, urea breath-testing includes mouth rinsing with water immediately after the ingestion of (13)C-urea solution, to prevent false-positive results that are caused by oral bacteria with urease activity. Our objective was to evaluate the diagnostic performance of a urea breath test using a film-coated (13)C-urea tablet and omitting mouth rinsing. METHODS: The study was a multicenter trial comparing the solution- and tablet-based urea breath tests (UBTs). Helicobacter pylori status was determined by histology, culture, and rapid urease testing. RESULTS: Of the 255 subjects who completed the study, evaluation of the tablet-based UBT was possible in 254, and comparison of the tablet-based UBT and the solution-based UBT was possible in 250 patients. When the assessment achieved by a combination of biopsy-based methods was used as a reference standard, the sensitivity, specificity, and accuracy of the tablet-based method were determined to be 97.7%, 98.4%, and 98.0%, respectively. When the results of the solution-based UBT were used as a reference standard, the sensitivity, specificity, and accuracy of the tablet-based UBT were determined to be 96.9%, 97.6%, and 97.2%, respectively. CONCLUSIONS: The (13)C-urea tablet-based method proved to be a simple and accurate test for the diagnosis of H. Pylori infection. Mouth rinsing was not required. [ABSTRACT FROM AUTHOR]

New pump and signal laser sources for difference frequency generation (DFG) at 4 μm are described. A laser diode with a 980 nm fiber Bragg grating and a 785 nm Fabry-Perot (FP) laser diode were coupled into an optical fiber and mixed in a periodically poled Mg-doped lithium niobate (PPMgLN ) crystal, resulting in efficient mid-IR DFG. The DFG power was measured to be 0.23 μW for a pump power of 5 mW and a signal power of 50 mW with a slope efficiency of 0.92 mW/W[sup 2]. A Doppler-broadened absorption spectrum of N[sub 2]O at 2485.2 cm[sup -1] (3.927 μm) was observed in a 0.1 m-long gas cell at a pressure of 133 Pa. The spectral linewidth of the DFG source was estimated to be 161 MHz (FWHM) for an averaging time of 700 ms. Real-time monitoring of N[sub 2]O in a multipass cell with an optical path length of 36 m at a concentration level of 1 ppm was demonstrated. [ABSTRACT FROM AUTHOR]

A new electron Bemstein wave emission diagnostic consisting of a heterodyne radiometer and a reflectometer was installed on TST-2. The instrument has a frequency range from 5 to 12 GHz which covers partially the fundamental and fully covers the second and third harmonic emissions. X-mode emission perpendicular to the flux surface, generated by B-X-FX mode-conversion scenario, is measured. The mode-conversion efficiency is calculated using a one-dimensional full-wave code with the density profile obtained simultaneously from the reflectometer, and the electron temperature (T[sub e]) is estimated. The levels corresponding to the 100-150 eV range are measured from the plasma core region, and the mode-conversion efficiency is calculated to be 0.5-0.8, leading to T[sub e] of approximately 200 eV. In addition, it is found that the reflectivity measured by the reflectometer is consistent with the calculated mode-conversion efficiency. This property can be used for a direct measurement of the mode-conversion efficiency. [ABSTRACT FROM AUTHOR]

Discusses the synthesis of particles of zinc oxide doped with europium by spray pyrolysis in a microgravity environment. Description of the spray pyrolysis apparatus; Morphology of the particles; Effect of gravity on the final morphology of particles.

A new type of ‘high performing companies’ has emerged in Japan producing a turning phase from analog to digital manufacturing. Though the definition of ‘virtual factory’ is neither matured nor persuasive in the revolutionizing manufacturing industry, more strategic interests are focused on this viable concept. Most of their initiatives are concentrated on the conceptualization phase of the virtual factory, but the latest experiments using web technology enlighten entrepreneurs to change their management strategies towards its achievement. Their experiences are summarized into three points. First, ‘management by projects’ is launched to challenge the practical goals of development. Second, the manufacturing strategy focuses on the fusion of core technology and IT, which surpasses to its competitors. Third, technologies like web, simulator machines and applications are innovated so rapidly to achieve a virtual environment. [ABSTRACT FROM AUTHOR]

A variety of spray pyrolysis (SP) techniques have been developed to directly produce ceramic powders from solutions. Examples that are discussed include the following powders: (La0.8Sr0.2)0.9MnO3-YSZ (La(Sr)MnO3-YSZ), La0.6Sr0.4CoO3 (La(Sr)CoO3), (CeO2)0.8(SmO1.5)0.2-NiO (SDC-NiO) and La0.9Sr0.1Ga0.8Mg0.2O3-NiO (LSGM-NiO). For all these powders, spherical, non-agglomerated, submicrometer particles were obtained from aqueous solution of metal salts into a furnace using an ultrasonic atomizer at 1.7 MHz. After SP some of the particles exhibit a hollow-shell morphology. Subsequent calcination at 1000°C yielded crystalline particles. The electrical performance of Ni-SDC/LSGM/La(Sr)CoO3 fuel cells operating at 800°C, prepared from the powders obtained by SP, is reported. [ABSTRACT FROM AUTHOR]

To clarify the role of colonic mucin in the autoimmune process of ulcerative colitis, circulating antibodies against human colonic mucin were investigated. Purified colonic mucin, obtained from human colonic mucosa by gel filtration, using a Bio-Gel A-1.5-m column and CsCl equilibrium density gradient, was divided into soluble mucin (S-mucin) secreted extracellularly and membranous mucin (M-mucin) binding to cell membrane. Sodium dodecylsulfate polyacrylamide gel electrophoresis and Western blotting analysis showed that antibodies in the serum samples of some patients with ulcerative colitis recognized purified S- and M-mucin of >180-kD. By enzyme-linked immunosorbent assay (ELISA), anti-mucin antibodies were detected in 11 of 60 patients with ulcerative colitis (18%). In contrast, the antibodies were not detected in 22 patients with Crohn's disease. The titers of antimucin antibodies against S-mucin and M-mucin were not different in each patient. By ELISA using mucin in which the sugar chains were destroyed by neuraminidase or NaIO4 treatment, it was demonstrated that anti-mucin antibodies recognized the epitopes of either the sugar chain or the core protein exposed through destruction of the sugar chains. We then investigated the relationship between anti-mucin antibodies and the patients' clinical features. Anti-mucin antibodies were detected in 6 of 15 patients with chronic continuous type ulcerative colitis (40%) and in 5 of 26 patients with relapsing-remitting type (19%), but there was no antimucin antibody-positive serum in patients who had had only one attack without any relapse. These results suggest that anti-mucin antibodies could be a disease marker for ulcerative colitis and that immunological abnormalities in colonic mucin contribute to the persistence of colonic mucosal inflammation. [ABSTRACT FROM AUTHOR]

Depletion of goblet cells (the main mucin-producing cells in the colon) is one of the most reliable histological characteristics of ulcerative colitis, whereas a major symptom of this disease is bloody diarrhea containing a large amount of mucus. The discrepancy between these phenomena was investigated in a time-course study in rats with experimental colitis induced by treatment with oral dextran sulfate sodium (DSS) for 1, 3, or 5 days. Biochemical analysis showed a reduction in mucin content in the distal side of the colon that was proportional to the duration of DSS administration. In the proximal side of the colon, however, there was a significant increase in mucin content already on the first day of treatment with DSS. This increase in colonic mucin content continued for the 5 days of treatment. In the distal side, both sulfomucin and sialomucin decreased proportionally to the duration of DSS administration. In the proximal side, there was an increase in high iron diamine-Alcian blue-positive mucins, and confirming the proliferation of goblet cells. The proliferated glands were predominantly sialylated. Goblet cell depletion and an increase in mucin production occurred in different parts of the colon. This phenomenon may be a type of compensatory function of colon tissue in response to the localized decrease of mucin production in certain portions of the colon. [ABSTRACT FROM AUTHOR]

We have recently reported that steady-state gastric mucosal blood flow (GMBF) is decreased in streptozotocin (STZ) diabetic rats, and that their GMBF response to burn-stress is impaired, probably via a nitric oxide (NO)-mediated mechanism. Accordingly, this study was designed to investigate the relation of aldose reductase (AR) and NO synthase to the regulation of GMBF during chronic hyperglycemia. STZ rats were treated with or without chronic oral administration of an AR inhibitor, epalrestat (EPA) and/or an NO synthase inhibitor, N-nitro-L-arginine methyl ester (L-NAME). GMBF was measured by laser-Doppler velocimetry (LDV). In the STZ rats, GMBF after a 24-h fasting period was decreased significantly 4 weeks after the onset of diabetes and this was accompanied by an increase in the gastric ulcer index (UI) (a measure of the length of gastric erosions and ulcers). Chronic oral administration of EPA to the STZ rats dose-dependently inhibited the increased UI and the decreased GMBF after the fasting stress, whereas chronic oral administration of L-NAME further increased the UI and further decreased the GMBF. EPA administered in combination with L-NAME to the STZ rats reduced the effects of L-NAME, but the effects did not reach significance. These results suggest that EPA protects the gastric mucosa of diabetic rats, by preventing the decrease in GMBF that is, at least in part, caused by NO-related mechanisms. [ABSTRACT FROM AUTHOR]

In recent years Helicobacter pylori infection has been implicated in the etiology of a variety of upper gastrointestinal diseases. The aim of this multi-center trial was to search for the cut-off value of the simple 13C-urea breath test (13C-UBT) for diagnosis of H. pylori infection, and to examine the sensitivity and specificity of 13C-UBT for culture, the rapid urease test (CLO test), histology, and serological tests. Two hundred and forty-eight patients participated in this study after giving their informed consent. Endoscopic biopsy specimens were taken from gastric antrum and corpus for culture (190 patients), CLO test (222 patients), and histology (98 patients). A serological test was carried out for all patients. H. pylori infection was established when culture was positive or more than two of the tests, histology, CLO test, and serological test, were positive, and non-infection status was established when the all tests more than two tests were negative. After baseline breath samples were taken, the patients (who had fasted) were given 100mg of 13C-urea in 100ml water while sitting; they washed out the mouth with water. They were then placed in the left lateral decubitus position for 5 min, and additional breath samples were taken 10, 20, 30, 45, and 60 min after urea administration, with patients in the sitting position. One hundred and sixty-five of the 248 patients were infected, 48 were not infected, and H. pylori infection status was not evaluated in 35 by endoscopic and serological tests. Breath samples at 20 min were employed to determine the cut-off value. Using the receiver operating characteristic (ROC) curve, we determined the cut-off value for a positive UBT at 2.5 delta per thousand. The sensitivities of UBT for culture, CLO test, histology, and serological test were 98.4%, 98.6%, 100.0%, and 92.5%, and the specificities were 78.8%, 82.5%, 83.3%, and 87.3%, respectively. The cut-off value of 13C-UBT for the diagnosis of H. pylori infection was 2.5 delta per thousand; this test is a simple and noninvasive method for the diagnosis of this infection and has high sensitivity and specificity. [ABSTRACT FROM AUTHOR]

Expression of members of the epidermal growth factor family, including epidermal growth factor (EGF), transforming growth factor-alpha (TGF-alpha), amphiregulin (AR), and Cripto, as well as their putative receptor, epidermal growth factor receptor (EGFR), was studied immunohistochemically in human gastric mucosa to evaluate their possible roles in cell proliferation of normal and regenerative gastric mucosa. We also examined the correlation betwen cell proliferation and EGFR by double immunohistochemical staining for proliferating cell nuclear antigen (PCNA) and EGFR. In normal gastric mucosa, TGF-alpha, Cripto, and AR immunoreactivities were observed in the surface epithelial and parietal cells of gastric fundic glands, respectively. EGF immunoreactivity was not observed in any of normal mucosa examined. EGFR immunoreactivity was detected on foveolar cells in proliferative zones and in parietal cells. Double immunostaining revealed that EGFR immunoreactivity was distributed much more widely than PCNA immunoreactivity. PCNA positive epithelial cells adjacent to gastric ulcer margin expressed relatively intense EGFR but did not express any of the growth factors examined. On the other hand, relatively intense immunoreactivity of both TGF-alpha and Cripto was detected in PCNA-negative regenerative epithelium located distant from gastric ulcer margin. Relative immunoreactivity of AR in regenerative gastric epithelium associated with ulcer was not different from that in normal gastric mucosa. TGF-alpha, AR, and Cripto are considered to play important roles in normal gastric mucosal proliferation, and TGF-alpha and Cripto may be involved in ulcer healing, possibly via a paracrine mechanism. [ABSTRACT FROM AUTHOR]

Quantitative changes of gastric mucosal glycoproteins with the gastric damage induced by acetylsalicylic acid (aspirin) in rat have been studied. Gastric injury was easily observed macroscopically within one hour after the oral administration of aspirin. The most striking changes occurred at five hours, and the injury was overcome within nine hours after dosing. The glycoproteins extracted from rat stomack with Tris buffer containing Triton X-100 were fractionated on Bio-Gel A-1.5 m column chromatography and divided into three fractions. The first peak, corresponding to gastric mucus macromolecular neutral and acidic glycoproteins with or without sulphate (Fr.I), was diminished after aspirin administration. A considerable alteration of Fr.I (49% of control) appeared at three hours, and a gradual return to the control value was observed subsequently. The changes in the amount of the glycoproteins were detected before the macroscopical changes of the mucosa. These results suggest that gastric ulceration induced by aspirin may be caused by a deficiency of gastric mucus macromolecular glycoproteins of gastric mucus. [ABSTRACT FROM PUBLISHER]

Intraperitoneal (ip) injection of ketamine increased the concentration of dynorphin in the cortex of rat brain, while decreased it in the septal area. The affinity of ethylketocyclazocine (EKC) receptor binding was decreased in the cortex, but increased in the septal area after pretreating the rats with ketamine. This suggests that the dynorphin neuronal system is stimulated in the cortex and suppressed in the septal area by ketamine. In other 5 brain areas, ketamine had no effect on neither dynorphin concentration nor EKC receptor binding. As dynorphin was reported to produce seizure and spike discharge in the cortex while suppressed the hippocampal EEG of rat brain, it is likely that the dynorphin neuronal system may play at least a part in ketamine induced electrophysiological changes in the brain. [ABSTRACT FROM AUTHOR]