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Background Autoimmune gastritis (AIG) is histologically classified into three phases according to the severity of oxyntic mucosal atrophy: early, florid, and end phases. This study aimed to clarify the relationship between the AIG phase and the anti-parietal cell antibody titer. Methods Patients who underwent upper gastrointestinal endoscopy were retrospectively reviewed in this study. We enrolled patients who were histologically diagnosed with AIG and serologically tested for anti-parietal cell antibody (APCA). AIG patients were classified into three groups: early, florid, and end phase groups. Clinical characteristics, including APCA titers, were compared among these three groups. Results A total of 44 AIG patients were enrolled. There were two patients in the early phase, 11 in the florid phase, and 31 in the end phase. APCA-positive rates were 100% in the early phase, 90.9% in the florid phase, and 90.3% in the end phase. The mean APCA titer was 480 U in the early phase, 220 U in the florid phase, and 150 U in the end phase. There was a stepwise decrease in the APCA titer from the early phase to the end phase. The mean APCA titer for the end phase was significantly lower than that of the early phase or florid phase. Additionally, there was a stepwise decrease in serum gastrin levels from the early phase to the end phase. Conclusion AIG progresses from the early phase to the end phase, and the APCA titer shows a decrease. The negativity of APCA could occur, especially in the end phase.

Clinical features of cardiac nodularity-like appearance induced by Helicobacter pylori infection

Background Bleeding after endoscopic submucosal dissection (ESD) is a severe adverse event. Recent reports have described the efficacy of the endoscopic shielding method with polyglycolic acid (PGA) sheets and fibrin glue for the prevention of adverse events after ESD. The aim of the present study was to investigate whether the PGA shielding method provides additional benefit in preventing post-ESD bleeding compared with standard care. Methods This was a prospective, multicenter, randomized controlled trial. Patients at high risk of post-ESD bleeding were enrolled in the study. Before ESD, patients were randomized to either the PGA group or the control group. After completing ESD in the PGA group, PGA sheets were placed onto the ulcer floor and adhered with fibrin glue. The primary end point was the post-ESD bleeding rate. Results 140 eligible patients were enrolled from September 2014 to September 2016, and 137 were included in the intention-to-treat analysis (67 in the PGA group and 70 in the control group). Post-ESD bleeding occurred in three patients (4.5 %) in the PGA group and in four patients (5.7 %) in the control group; there was no significant difference between the two groups (P > 0.99). Post-ESD bleeding tended to occur later in the control group than in the PGA group (median 12.5 days [range 8 – 14] vs. 2 days [range 0 – 7], respectively). Conclusion The PGA shielding method did not demonstrate a significant effect on the prevention of post-ESD bleeding.

Background: The diagnostic clues for autoimmune gastritis (AIG) can be classified into 2 categories: endoscopic findings and pathological diagnosis. We believe that research on the AIG detection rate by endoscopists could provide a better understanding of the diagnosis of AIG. This study aimed to clarify the ratio of the endoscopic and the pathological diagnoses of AIG. Methods: We retrospectively reviewed consecutive patients who underwent esophagogastroduodenoscopy (EGD). During their first EGD, the gastric mucosa with C2 atrophy or more was biopsied for pathological evaluation based on the updated Sydney system. A gastric biopsy was also performed after Helicobacter pylori eradication, obtaining specimens from at least 2 sites, the greater curvature of the corpus and the antrum. We enrolled patients who were positive for the anti-parietal cell antibody and were diagnosed with AIG, histologically and/or endoscopically. The detection rates of AIG were compared between endoscopic diagnosis and pathological diagnosis. Results: A total of 10,822 patients underwent EGD during the study period. Finally, 41 patients with AIG were enrolled, leading to an AIG prevalence of 0.38% in this study. As for the clue leading to AIG detection, 31.7% (13/41) were diagnosed through endoscopy (proximal-predominant atrophy), and 68.3% (28/41) were diagnosed pathologically. The AIG detection rate by endoscopists in the posteradication group was significantly lower than in the H. pylori-negative group (p < 0.05). Conclusion: Endoscopists frequently overlooked AIG, especially in posteradication cases. Pathological assessment using the updated Sydney system after H. pylori eradication might be a promising strategy to detect AIG better.

Background and study aims Adenoma detection rate (ADR) is an important quality indicator in colonoscopy, and improved ADR decreases the incidence of colorectal cancer. We investigated differences in polyp detection according to the endoscopist’s ADR. Patients and methods We performed a propensity-score matching study using baseline patient characteristics of age, sex, body mass index, family history of colorectal cancer, smoking, drinking, indication for colonoscopy, bowel preparation, and colonoscope type. We compared polyp detection and colonoscopy procedures between patients who underwent colonoscopy by high-ADR endoscopists (high ADR group) and by low-ADR endoscopists (low ADR group). Results We matched 334 patients in the high ADR group with 334 in the low ADR group. The ADR was 44.0 % and 26.9 % for the high-ADR and low-ADR endoscopists, respectively. Proximal, nonprotruding, and diminutive adenomas were more frequently detected by high-ADR endoscopists than by low-ADR endoscopists (all P Conclusions Expert detectors often found nonprotruding and diminutive adenomas in the proximal colon along with increased detection rate of high-risk adenomas. Low-ADR endoscopists need to recognize the features of missed adenomas to improve their ADRs.

Aim To investigate the clinicopathological features of the patients testing negative for high titer serum anti-Helicobacter pylori (H. pylori) antibody. Methods The antibody titers were measured using antigens derived from Japanese individuals. 13C-urea breath test-positive individuals were defined as having H. pylori infection. We investigated the demographic characteristics, laboratory data, endoscopic findings including Kyoto classification of gastritis, and histology in negative-high titer patients without H. pylori eradication therapy. Kyoto classification consisted of scores for gastric atrophy, intestinal metaplasia, enlarged folds, nodularity, and redness. Results Of the 136 subjects enrolled, 23 (17%) had H. pylori infection. Kyoto classification had an excellent area under the receiver operating characteristics curve (0.886, 95% confidence interval: 0.803-0.968, P = 3.7 × 10-20) for predicting H. pylori infection with a cut-off value of 2. Further, Kyoto classification, H. pylori density, and neutrophil activity had high accuracies (89.7%, 96.3%, and 94.1%, respectively). Kyoto classification was independent of the demographic and laboratory parameters in multivariate analysis. Conclusion Endoscopic Kyoto classification of gastritis is a useful predictor of H. pylori infection in negative-high titer antibody patients.

Background and study aims Endosurgical devices with injection function have been reported to decrease endoscopic submucosal dissection (ESD) operation times for experts, but the efficacy of these devices for inexperienced endoscopists is unclear. The aim of this study was to evaluate the feasibility of ESD using a novel ESD knife (DN-D2718B). Patients and methods This is a single-center prospective pilot clinical feasibility study. Patients diagnosed with superficial gastrointestinal neoplasms were enrolled. A pre-specified group of ESD trainees with ESD experience on a porcine gastric model and fewer than 30 cases of ESD in their selected fields performed ESD under expert supervision, using the DN-D2718B. En bloc resection rates, R0 resection rates, procedure times, and incidence of intra-operational/post-operational adverse events were assessed. Results Between June 2015 and January 2016, 13 esophageal, 27 gastric, and 14 colorectal ESD cases were performed per-protocol with mean resection speeds of 10.2, 12.0, and 15.5 mm2/min, respectively. There were no intra-operational complications. Conclusion ESD with this novel knife is feasible even when performed by non-experts.

Nausea and vomiting after esophagogastroduodenoscopy have not been studied in detail. The aim of this study was to evaluate the risk factors for post-endoscopic nausea. We performed a case-control study at the Toyoshima Endoscopy Clinic. Eighteen patients with post-endoscopic nausea and 190 controls without post-endoscopic nausea were analyzed. We conducted univariate and multivariate logistic regression analyses with respect to patient age; sex; body height; body weight; the use of psychotropic drugs as baseline medications; and the dosing amounts of midazolam, pethidine, flumazenil and naloxone. On univariate analysis, post-endoscopic nausea was significantly related with patient age (odds ratio = 0.946); female sex (odds ratio = 10.85); body weight (odds ratio = 0.975); and the dose per kg body weight of pethidine (odds ratio = 53.03), naloxone (odds ratio = 1.676), and flumazenil (odds ratio = 1.26). On multivariate analysis, the dose per kg body weight of pethidine (odds ratio = 21.67, p = 0.004) and female sex (odds ratio = 13.12, p = 0.047) were the factors independently associated with post-endoscopic nausea. The prevalence of nausea after esophagogastroduodenoscopy was 0.49% (18/3,654). In conclusion, post-endoscopic nausea was associated with the dose of pethidine and female sex.

Background Helicobacter pylori eradication therapy is commonly performed to reduce the incidence of gastric cancer. However, gastric cancer is occasionally discovered even after successful eradication therapy. Therefore, we examined the prognosis of gastric cancer patients, diagnosed after successful H. pylori eradication therapy. Materials and Methods All‐cause death rates and gastric cancer‐specific death rates in gastric cancer patients who received successful H. pylori eradication treatment was tracked and compared to rates in patients who did not receive successful eradication therapy. Results In total, 160 gastric cancer patients were followed‐up for up to 11.7 years (mean 3.5 years). Among them, 53 gastric cancer patients received successful H. pylori eradication therapy prior to gastric cancer diagnosis. During the follow‐up period, 11 all‐cause deaths occurred. In the successful eradication group, the proportion of patients with cancer stage I was higher. The proportions of patients who received curative endoscopic therapy and endoscopic examination in the 2 years prior to gastric cancer diagnosis were also higher in the successful eradication group. Kaplan–Meier analysis of all‐cause death and gastric cancer‐specific death revealed a lower death rate in patients in the successful eradication group (P = .0139, and P = .0396, respectively, log‐rank test). The multivariate analysis showed that endoscopy within 2 years before cancer diagnosis is associated with stage I cancer. Conclusions Possible early discovery of gastric cancer after H. pylori eradication due to regular endoscopic surveillance may contribute to better prognosis of patients with gastric cancer.

Double-contrast upper gastrointestinal barium X-ray radiography (UGI-XR) is the standard gastric cancer screening method in Japan. Atrophic gastritis and enlarged gastric folds are considered the two major features of Helicobacter pylori-induced chronic gastritis, but the clinical meaning of evaluating them by UGI-XR has not been elucidated. We analyzed healthy UGI-XR examinees without a history of gastrectomy, previous Helicobacter pylori eradication and usage of gastric acid suppressants. Of the 6433 subjects, 1936 (30.1 %) had atrophic gastritis and 1253 (19.5 %) had enlarged gastric folds. During the 3-year prospective observational follow-up, gastric cancer developed in seven subjects, six of whom (85.7 %) had atrophic gastritis with H. pylori infection and five of whom (71.4 %) had enlarged gastric folds with H. pylori infection. The Kaplan-Meier method with log-rank testing revealed that both UGI-XR-based atrophic gastritis (p = 0.0011) and enlarged gastric folds (p = 0.0003) are significant predictors for future gastric cancer incidence.

Background and study aims: Suitable techniques for the prevention of stricture formation after esophageal endoscopic submucosal dissection (ESD) are still lacking. We investigated the efficacy of polyglycolic acid (PGA) sheets with fibrin glue to prevent post-ESD stricture. Patients and methods: We conducted a pilot study on a total of eight consecutive patients who underwent esophageal ESD that left a mucosal defect of more than three-quarters of the esophageal circumference. PGA sheets were attached to the defect with fibrin glue immediately after the completion of ESD. The primary endpoint was the incidence of post-ESD stricture. The secondary endpoints were the number of sessions of endoscopic balloon dilation (EBD) required to resolve any stricture and the rate of complications. Results: There were no adverse events related to the use of PGA sheets and fibrin glue. Post-ESD stricture occurred in 37.5 % of the subjects and 0.8 ± 1.2 sessions of EBD were required. Conclusion: The use of PGA sheets and fibrin glue after esophageal ESD is a novel method that radically decreases the incidence of esophageal stricture and the number of EBD sessions subsequently required. University Hospital Medical Network Clinical Trial Registry (UMIN000011058).

Endoscopic submucosal dissection (ESD) has become widely accepted as a standard method of treatment for superficial gastrointestinal neoplasms because it enables en block resection even for large lesions or fibrotic lesions with minimal invasiveness, and decreases the local recurrence rate. Moreover, specimens resected in an en block fashion enable accurate histological assessment. Taking these factors into consideration, ESD seems to be more advantageous than conventional endoscopic mucosal resection (EMR), but the associated risks of perioperative adverse events are higher than in EMR. Bleeding after ESD is the most frequent among these adverse events. Although post-ESD bleeding can be controlled by endoscopic hemostasis in most cases, it may lead to serious conditions including hemorrhagic shock. Even with preventive methods including administration of acid secretion inhibitors and preventive hemostasis, post-ESD bleeding cannot be completely prevented. In addition high-risk cases for post-ESD bleeding, which include cases with the use of antithrombotic agents or which require large resection, are increasing. Although there have been many reports about associated risk factors and methods of preventing post-ESD bleeding, many issues remain unsolved. Therefore, in this review, we have overviewed risk factors and methods of preventing post-ESD bleeding from previous studies. Endoscopists should have sufficient knowledge of these risk factors and preventive methods when performing ESD.

Triamcinolone Injection and Shielding with Polyglycolic Acid Sheets and Fibrin Glue for Postoperative Stricture Prevention after Esophageal Endoscopic Resection: A Pilot Study

Molecular dynamics (MD) simulations of a Lennard-Jones system are performed to obtain the pVT and UVT relations. An extended van der Waals equation of state (EOS) is derived by statistical mechanic...

The Micro Pixel Chamber (μ-PIC) has been developed for a hadron-collider experiment. The main purpose is detecting Minimum Ionizing Particles (MIP) under high-rate Highly Ionizing Particles (HIP) environment. In such an environment, sufficient gain to detect MIP is needed, but continuous sparks will be caused by high-rate HIP. To reduce sparks, cathodes are made of resistive material. In this report, sputtered carbon was used as a new resistive cathode. Gas gain >104 was achieved using an 55Fe source. This value is sufficient to detect MIP without GEM or other floating structures. Also, thanks to production improvement, pixels are well aligned in the entire detection area.

The Gibbs free energies of proton-ordered ices were estimated by molecular dynamics simulations. The ordered structures were obtained using NTV ensemble molecular dynamics of cells with small numbers of molecules, where the cut off distance for short range interaction was 1.4×10-9 m. The internal energy and volume were obtained by NTp molecular dynamics simulations at T = 1 K for each type of ice, where the cut off distance for short range interaction was half of the unit cell and the Ewald method was used to determine coulombic interaction. The infinite number limits in the internal energies of each ice type at T = 1 K were estimated. The enthalpy temperature dependence was calculated and the low temperature limit was estimated to obtain the Gibbs free energy at low temperatures. Phase transition pressures obtained were satisfactory when compared with the experimental results, at least qualitatively.

Molecular dynamics simulations on the Lennard-Jones system are performed to obtain the pVT and UVT relations. An extended van der Waals equation of state (EOS) is derived by statistical mechanics on the perturbation approximation. A hard sphere system is used as the reference system. The attraction energy term in the canonical ensemble partition function is extended by a cluster expansion. The new EOS includes three parameters, two of which are the interaction parameters in the Lennard-Jones interaction. The last parameter is the effective volume of the hard sphere system. The extended van der Waals EOS reproduces the pVT and UVT relations, at least qualitatively, whereas the original van der Waals EOS can explain only the pVT relation.

The pressure–volume–temperature (pVT) relations for intermolecular interactions described by a repulsive step-function are obtained by molecular dynamics (MD) and Monte Carlo (MC) simulations. The system is modeled as a cubic unit cell with periodic boundary condition, where the unit cell contains 108 molecules. The pressure is obtained by the virial equation, and the phase diagram is estimated by Maxwell construction. The self-diffusion coefficients are calculated by MD simulation and used to assign phases as solid or fluid. High- and low-density solid and fluid phases are identified at low temperatures, and negative expansion is observed in the fluid phase near the low-density solid.

Background Despite the marked increase of diverticulosis, its risk factors have not been adequately elucidated. We therefore aim to identify significantly associated factors with diverticulosis. We also aim to investigate the present state of diverticulosis in Japan. Methods We reviewed the medical records from 1990 to 2010 that included the data of consecutive 62,503 asymptomatic colonoscopy examinees from the general population in Japan. Most recent 3,327 examinees were analyzed with 16 background factors. Results Among the 62,503 subjects (47,325 men and 15,178 women; 52.1 ± 9.2 years old), diverticulosis was detected in 11,771 subjects (18.8%; 10,023 men and 1,748 women). The incidences of diverticulosis in 1990-2000 and 2001-2010 were respectively 13.0% (3,771 of 29,071) and 23.9% (8,000 of 33,432): the latter was much higher than the former in all age groups and for both genders. Considering the anatomical locations of colorectal diverticula, left-sided ones have markedly increased with age but not significantly changed with times. Univariate analyses of the 3,327 subjects showed significant association of diverticulosis with four basic factors (age, sex, body mass index, blood pressure), three life style-related factor (smoking, drinking, severe weight increase in adulthood), and two blood test values (triglyceride, HbA1c). The multiple logistic analysis calculating standardized coefficients (β) and odds ratio (OR) demonstrated that age (β = 0.217-0.674, OR = 1.24-1.96), male gender (β = 0.185, OR = 1.20), smoking (β = 0.142-0.200, OR = 1.15-1.22), severe weight increase in adulthood (β = 0.153, OR = 1.17), HbA1c (β = 0.136, OR = 1.15), drinking (β = 0.109, OR = 1.11), and serum triglyceride (β = 0.098, OR = 1.10) showed significantly positive association with diverticulosis whereas body mass index and blood pressure did not. Conclusions The large-scale data of asymptomatic colonoscopy examinees from the general population from 1990 to 2010 indicated that the prevalence of diverticulosis is still increasing in Japan. Age, male gender, smoking, severe weight increase in adulthood, serum HbA1c, drinking, and serum triglyceride showed significant positive association with diverticulosis.

In order to perform the statistical mechanical calculations, we adopt the periodic cubic system with two molecules in the unit cell. Our model potential function consists of a step-function and the hard sphere wall. We assume the minimum image convention and get the canonical partition function. We find the fluid–fluid phase transition and the negative thermal expansion in the system. We discuss the thermodynamic properties vs. temperature plots under the constant volume. We show some results of the Monte Carlo (MC) simulations on the system with the same potential function under the periodic cubic boundary condition for a comparison. The theoretical results on pVT relations are in agreement with the MC simulations on the two-molecule system. The results of 108-molecule system with the MC simulations are expected to have the similar phase transition near the state in the case of the two-molecule system.

We estimated the free energy of homogeneous nucleation in supersaturated Lennard-Jones vapor phase by using Monte Carlo simulations. The nucleation free energy of an N-particle cluster is obtained as the difference between the free energies of the cluster phase and the monomer phase in an N-particle system. In the previous papers, we estimated the Helmholtz free energy of the nucleation by MC calculations under a fixed volume per particle, V/N = 43.2 σ3, and the equation of state of the nucleation energy as a function of cluster size and temperature. In this study, we carried out some additional MC calculations under different volumes per particle and took into consideration the pressure to estimate the Gibbs free energy of the nucleation. Then we established the equations of state of the Helmholtz and Gibbs free energies of nucleation as a function of cluster size, temperature, and volume or pressure.

We performed Monte Carlo simulations for the homogeneous nucleation on supersaturated Lennard–Jones vapor phase to estimate the equation of state for free energy of the nucleation. The calculations were performed on each system with a fixed number of particles. The initial configuration was distorted cubic lattice. The sample was cooled to low temperature, where all particles become a cluster. In the second stage it was heated enough to vaporize; the monomer phase was obtained. In the third run, the stabilized cluster was heated under the condition that the cluster was not allowed to decompose. In the last run, the system was cooled from initial monomer phase with a condition that the particles were not allowed to make any connections. Helmholtz free energies of the cluster and the monomer phase were obtained by thermodynamic integration. The obtained size of critical nucleus was comparable to the results of the molecular dynamics simulation.

The free energy of homogeneous nucleation is estimated by the Monte Carlo simulations on the supersaturated Lennard-Jones (LJ) vapor phase. The calculation is performed on the each system with a fixed number of particles N (1 < N < 109). The periodic boundary condition is assumed. The volume per a particle is 43.2 in units of LJ system. No carrier gas particles are included. The range of temperature is from 0.01 to 1.00 in units of Lennerd-Jones system. The initial configuration is distorted cubic lattice, and the sample is cooled to low temperature, where all molecules become a large cluster. In the second stage, it is heated to vaporize, where the monomer phase is obtained. In the third run, the low temperature sample is heated with a condition that the cluster is not allowed to decompose in the Monte Carlo (MC) simulations. The free energies of the cluster phase and the monomer one are obtained by the thermodynamic integration. The obtained critical size is about 30-40 at temperature 0.67 in units of LJ system, which is comparable to the molecular dynamics (MD) simulation with the carrier gas particles.

Argon microcluster constituted by 8 molecules was calculated to investigate phase transition from cohesive phase to vapor phase by the molecular dynamics method ("MD method"). The microcluster was calculated under various setting conditions such as changing career gas number and pressure in order to find the optimal setup for observing the phase transition. Then various thermodynamics quantities (internal energy, enthalpy, heat capacity, entropy and free energy) were obtained under the optimal setup conditions. And the calculation results of MD were compared to the results of the Monte Carlo method ("MC method") in order to examine the suitability of the setting condition of MD method, reliability of the obtained thermodynamic quantity and accuracy of leading procedure from internal energy to free energy.