Nonlocal Spin Correlation as a Signature of Ising Anyons Trapped in Vacancies of the Kitaev Spin Liquid.

In the Kitaev chiral spin liquid, Ising anyons are realized as Z_{2} fluxes binding Majorana zero modes, which, however, are thermal excitations with finite decay rates. On the other hand, a lattice vacancy traps a Z_{2} flux even in the ground state, resulting in the stable realization of a Majorana zero mode in a vacancy. We demonstrate that spin-spin correlation functions between two vacancy sites exhibit long-range correlation arising from the fractionalized character of Majorana zero modes, in spite of the strong decay of bulk spin correlations. Remarkably, this nonlocal spin correlation does not decrease as the distance between two vacancy sites increases, signaling Majorana teleportation. Furthermore, we clarify that the nonlocal correlation can be detected electrically via the measurement of nonlocal conductance between two vacancy sites, which is straightforwardly utilized for the readout of Majorana qubits. These findings pave the way to the measurement-based quantum computation with Ising anyons trapped in vacancies of the Kitaev spin liquid.

Spin-Nernst Effect in Time-Reversal-Invariant Topological Superconductors.

We investigate the spin-Nernst effect in time-reversal-invariant topological superconductors, and show that it provides smoking-gun evidence for helical Cooper pairs. The spin-Nernst effect stems from asymmetric, in spin space, scattering of quasiparticles at nonmagnetic impurities, and generates a transverse spin current by the temperature gradient. Both the sign and the magnitude of the effect sensitively depend on the scattering phase shift at impurity sites. Therefore the spin-Nernst effect is uniquely suitable for identifying time-reversal-invariant topological superconducting orders.

Proton Pump Inhibitor-Associated Large Hyperplastic Polyp in Non-Helicobacter pylori-Infected Stomach.

A proton pump inhibitor (PPI)-associated hyperplastic polyp (HP) in the non-Helicobacter pylori-infected stomach is rare, and its endoscopic features remain poorly described. A 42-year-old man with tarry stool was referred to our hospital for examination and treatment. He had taken PPI for 14 years and was confirmed to be H. pylori-negative. Transnasal endoscopy revealed bleeding from a 20-mm, reddish pedunculated polyp with a nodular surface, located in the greater curvature of the upper gastric body. Endoscopic mucosal resection was performed, and the lesion was diagnosed as an HP. To our knowledge, this report represents a valuable addition to the HP literature describing a rare case of PPI-associated large HP in the non-H. pylori-infected stomach.

Collision Tumor of the Stomach.

Collison tumor of the stomach is rare, and its endoscopic and pathological features remain poorly described. A 70-year-old woman was referred to our hospital for examination and treatment of undifferentiated gastric cancer. Esophagogastroduodenoscopy revealed a whitish, superficial elevated lesion in contact with a reddish, superficial depressed lesion from the anterior wall of the gastric angle and antrum to the lesser curvature. Laparoscopic distal gastrectomy was performed for preoperative diagnosis of suspected early gastric cancer presenting as a differentiated and undifferentiated collision tumor, which led to the lesion being diagnosed as collision tumor, tub1-tub2+por1-sig, pT1a (M), ly0, v0, N0, stage IA. To our knowledge, this report represents a valuable addition to the collision tumor literature describing a rare case of preoperatively diagnosed collision tumor of the stomach.

Detection of early adenocarcinoma of the esophagogastric junction by spraying an enzyme-activatable fluorescent probe targeting Dipeptidyl peptidase-IV.

BACKGROUND: It is still difficult to detect and diagnose early adenocarcinoma of the esophagogastric junction (EGJ) using conventional endoscopy or image-enhanced endoscopy. A glutamylprolyl hydroxymethyl rhodamine green (EP-HMRG) fluorescent probe that can be enzymatically activated to become fluorescent after the cleavage of a dipeptidyl peptidase (DPP)-IV-specific sequence has been developed and is reported to be useful for the detection of squamous cell carcinoma of the head and neck, and esophagus; however, there is a lack of studies that focuses on detecting EGJ adenocarcinoma by fluorescence molecular imaging. Therefore, we investigated the visualization of early EGJ adenocarcinoma by applying EP-HMRG and using clinical samples resected by endoscopic submucosal dissection (ESD). METHODS: Fluorescence imaging with EP-HMRG was performed in 21 clinical samples resected by ESD, and the fluorescence intensity of the tumor and non-tumor regions of interest was prospectively measured. Immunohistochemistry was also performed to determine the expression of DPP-IV. RESULTS: Fluorescence imaging of the clinical samples showed that the tumor lesions were visualized within a few minutes after the application of EP-HMRG, with a sensitivity, specificity, and accuracy of 85.7, 85.7, and 85.7%, respectively. However, tumors with a background of intestinal metaplasia did not have a sufficient contrast-to-background ratio since complete intestinal metaplasia also expresses DPP-IV. Immunohistochemistry measurements revealed that all fluorescent tumor lesions expressed DPP-IV. CONCLUSIONS: Fluorescence imaging with EP-HMRG could be useful for the detection of early EGJ adenocarcinoma lesions that do not have a background of intestinal metaplasia.

Changes of Dyspeptic Symptom after Successful Eradication in Helicobacter pylori-Associated Dyspepsia.

BACKGROUND: Helicobacter pylori (H. pylori) gastritis could cause dyspepsia, and eradication is recommended as the first-line treatment. Patients who continuously have their symptoms under control > 6 months after eradication are defined as having H. pylori-associated dyspepsia (HPD), whereas patients who do not benefit from successful eradication are defined as having functional dyspepsia. OBJECTIVES: We assessed changes in dyspeptic symptoms after successful eradication of H. pylori by using a questionnaire. METHODS: We studied H. pylori-infected dyspeptic participants with abdominal symptom scores > 4 points on the Global Overall Symptom (GOS) scoring items and received eradication therapy. We evaluated their symptoms using the GOS questionnaire before their eradications, at 1-month and at 1-year check-ups after eradication therapy. RESULTS: Thirty dyspeptic participants (mean age 59.6 ± 15.3 years) answered every questionnaire. Fourteen participants (46.7%) had HPD, whereas 16 participants (53.3%) were non-HPD patients. The questionnaire at 1 month showed sensitivity of 64.3% (9/14) and specificity of 56.3% (9/16) for HPD. Approximately 60% of H. pylori-infected dyspepsia participants were identified as having HPD or non-HPD within 1 month after their eradications. CONCLUSIONS: Approximately 60% of HPD participants improved at 1 month after eradication. The questionnaire at 1 month helped diagnose HPD in advance and guided next treatment choice.

Chiral Higgs Mode in Nematic Superconductors.

Nematic superconductivity with spontaneously broken rotation symmetry has recently been reported in doped topological insulators, M_{x}Bi_{2}Se_{3} (M=Cu, Sr, Nb). Here we show that the electromagnetic (EM) response of these compounds provides a spectroscopy for bosonic excitations that reflect the pairing channel and the broken symmetries of the ground state. Using quasiclassical Keldysh theory, we find two characteristic bosonic modes in nematic superconductors: the nematicity mode and the chiral Higgs mode. The former corresponds to the vibrations of the nematic order parameter associated with broken crystal symmetry, while the latter represents the excitation of chiral Cooper pairs. The chiral Higgs mode softens at a critical doping, signaling a dynamical instability of the nematic state towards a new chiral ground state with broken time reversal and mirror symmetry. Evolution of the bosonic spectrum is directly captured by EM power absorption spectra. We also discuss contributions to the bosonic spectrum from subdominant pairing channels to the EM response.

Negative Thermal Magnetoresistivity as a Signature of a Chiral Anomaly in Weyl Superconductors.

We propose that the chiral anomaly of Weyl superconductors gives rise to negative thermal magnetoresistivity induced by emergent magnetic fields, which are generated by vortex textures of order parameters or lattice strain. We establish this scenario by combining the argument based on Berry curvatures and the quasiclassical theory of the Eilenberger equation with quantum corrections arising from inhomogeneous structures. It is found that the chiral anomaly contribution of the thermal conductivity exhibits characteristic temperature dependence, which can be a smoking-gun signature of this effect.

Preventive effect of mesenchymal stem cell culture supernatant on luminal stricture after endoscopic submucosal dissection in the rectum of pigs.

BACKGROUND: Mesenchymal stem cells (MSCs) are valuable in regenerative medicine, and MSC culture supernatant (MSC-CS) reportedly inhibits inflammation and fibrosis. We investigated whether colorectal luminal stricture develops after circumferential endoscopic submucosal dissection (ESD) in the colorectum, and whether the development of luminal stricture could be prevented by using MSC-CS enema. METHODS: In the first experiment, we performed circumferential ESD in the rectums or distal colons of pigs (n = 4 in each group). We sacrificed the pigs on Day 22 and measured the degree of luminal stricture. In the second experiment, we performed circumferential ESD in the rectums of pigs and administered an MSC-CS gel or a control gel enema after ESD for 4 days. We sacrificed the pigs on Day 8 (n = 3 in each group) or 22 (n = 3 in each group) to measure the degree of luminal stricture, and performed histological analysis. RESULTS: Severe luminal stricture was observed in the rectum but not in the distal colon. Moreover, fiber accumulation in the submucosa and hypertrophy of the muscularis propria were observed in the rectum but not in the distal colon. The degree of luminal stricture in the rectum was significantly lower in the MSC-CS group than in the control group. Furthermore, MSC-CS attenuated myofibroblast activation and hypertrophy of the muscularis propria on Day 22, and reduced inflammatory cell infiltration on Day 8. CONCLUSIONS: Luminal stricture after ESD developed only in the rectum because of the difference in myofibroblast activation and fiber accumulation. In addition, MSC-CS enema prevented luminal stricture after ESD, possibly by inhibiting the inflammatory reaction and fibrosis.

Rapid detection of superficial head and neck squamous cell carcinoma by topically spraying fluorescent probe targeting dipeptidyl peptidase-IV.

BACKGROUND: A fluorescent probe glutamylprolyl hydroxymethyl rhodamine green (EP-HMRG), which becomes fluorescent after cleavage by dipeptidyl peptidase-IV (DPP-IV), has been reported to be useful for the detection of esophageal cancer. Thus, we investigated whether head and neck squamous cell carcinoma (HNSCC) can be detected by spraying EP-HMRG. METHODS: Fluorescence imaging of 17 cases of HNSCCs resected using endoscopic or surgical resection was performed ex vivo after spraying EP-HMRG, and then the fluorescence intensity of the tumors and normal mucosa were measured. RESULTS: Iodine-voiding lesions became fluorescent within a few minutes after the application of EP-HMRG in 12 resected tumors without a history of radiotherapy but this was not observed in the normal mucosa. Fluorescence intensity in tumor lesions was significantly higher than normal lesions. However, 5 other tumors that developed after radiotherapy did not have sufficient contrast against normal mucosa. CONCLUSION: Fluorescence imaging with EP-HMRG would be useful for rapid detection of superficial HNSCC without a history of radiotherapy.

Risk assessment of metachronous squamous cell carcinoma after endoscopic resection for esophageal carcinoma based on the genetic polymorphisms of alcoholdehydrogense-1B aldehyde dehydrogenase-2: temperance reduces the risk.

BACKGROUND: Metachronous multiple squamous cell carcinoma (SCC) of the esophagus and the head and neck is commonly observed in patients who have previously undergone endoscopic resection (ER) for SCC of the esophagus (ESCC). We evaluated the risk for developing metachronous SCC following ER for ESCC based on the genetic polymorphisms for alcohol dehydrogenase-1B (ADH1B) and aldehyde dehydrogenase-2 (ALDH2) as well as the alcohol consumption and smoking habits. METHODS: We studied 158 patients who underwent ER for ESCC (median follow-up 80 months). Genotyping of ADH1B/ALDH2 was performed using saliva sampling. The alcohol consumption and smoking histories of the patients before and after the ER were documented. RESULTS: Multivariate analyses revealed that inactive heterozygous ALDH2 [hazard ratio (HR) 2.25] and alcohol consumption after ER (HR 1.94) were independently associated with the risk of developing secondary SCC. Moreover, inactive heterozygous ALDH2 (HR 4.39) and alcohol consumption after the ER (HR 2.82) were independently associated with the risk of a third SCC. We analyzed 110 patients who had a history of moderate or heavy alcohol consumption before the ER. The 3-year cumulative incidence rates of secondary SCC in the temperance (n = 65) and non-temperance groups (n = 45) were 14.0 and 42.1% (p = 0.0002). Further, the 5-year cumulative incidence rates of a third SCC in the temperance and non-temperance groups were 0 and 15.6% (p = 0.0011), respectively. In addition, the 7-year cumulative incidence rates of a fourth SCC in the temperance and non-temperance groups were 0 and 15.3% (p = 0.0015), respectively. CONCLUSIONS: Continued alcohol consumption is an important risk factor for the onset of metachronous SCC and is a risk factor for the third and subsequent SCCs. Strict advice in favor of temperance is crucial.

Multicenter observational study on functional bowel disorders diagnosed using Rome III diagnostic criteria in Japan.

BACKGROUND: The Rome III diagnostic criteria had been used to diagnose functional gastrointestinal disorders (FGIDs) world wide, and functional bowel disorders (FBDs) including irritable bowel syndrome (IBS) have recently attracted the attention of Japanese physicians. However, there have been few reports on the prevalence of FBDs diagnosed by the Rome III diagnostic criteria. AIMS: The aim of this study was to determine the prevalence of FBDs diagnosed according to the diagnostic criteria of Rome III in Japan. PATIENTS AND METHODS: All patients who were booked for colonoscopy were enrolled from eight institutions in Japan. This study was a prospective observational study in the period from April 2013 to December 2013. Patients filled out FGID questionnaires of Rome III when they were waiting for colonoscopy. RESULTS: Data for 1200 patients who underwent colonoscopy were analyzed. A total of 547 patients (45.6%) were diagnosed with FBDs. Out of those patients, 9.1% had IBS. According to the Rome III diagnostic criteria, 134 patients (11.2%) had functional bloating (FB), 73 (6.1%) had functional constipation (FC), 40 (3.3%) had functional diarrhea (FD), and 191 (15.9%) had unspecified functional bowel disorder (UFBD). Patients with FBDs had significantly higher rates of almost all symptoms (abdominal pain, hard or lumpy stools, loose or watery stools, and bloating) than those in the controls. CONCLUSIONS: In Japan, the prevalence of FBDs and IBS is high, similar to that in the US. Many patients with FBDs have multiple symptoms.

Gastric Hyperplastic Polyps Associated with Proton Pump Inhibitor Use in a Case without a History of Helicobacter pylori Infection.

A 56-year-old man with gastroesophageal reflux disease (GERD) was referred to our hospital. Esophagogastroduodenoscopy (EGD) revealed no evidence of any polypoid lesions in the stomach, and the patient had no history of Helicobacter pylori infection. He received omeprazole (20 mg) once daily for the GERD. EGD was performed at 1 year after the start of omeprazole administration, and this time, gastric hyperplastic polyps (GHPs) were detected. The GHPs increased in size as the omeprazole treatment continued, but they markedly decreased in size following omeprazole discontinuation. Thus, the administration of proton pump inhibitors may be a risk factor for the development of GHP independent of H. pylori infection.

Endoscopic ultrasonography features of gastric mucosal cobblestone-like changes from a proton-pump inhibitor.

A 68-year-old man with no symptoms presented to Hokkaido University Hospital for esophagogastroduodenoscopy screening. He had a history of Helicobacter pylori eradication. Initial esophagogastroduodenoscopy showed no gastric cobblestone-like mucosa or gastric cracked mucosa. After 1 year, he received esomeprazole (20 mg) once daily for heartburn at another hospital. Esophagogastroduodenoscopy was performed after 2 years of esomeprazole administration. Endoscopic findings showed that after H. pylori eradication, according to the Kyoto classification, gastric cobblestone-like mucosa presented in the gastric body area. Dilation of the oval crypt opening and intervening part in the gastric cobblestone-like mucosa was detected by endoscopy with narrow band imaging. Endoscopic ultrasonography revealed a thick gastric second layer and sporadic small a-echoic lesions in the low-echoic thickened second layer in the gastric cobblestone-like mucosa. The gastric cobblestone-like mucosa biopsy specimen showed parietal cell protrusions and oxyntic gland dilatations. Recently, we reported that gastric mucosal changes such as gastric cracked mucosa and gastric cobblestone-like mucosa were caused by proton-pump inhibitors; however, the gastric cobblestone-like mucosa was not examined by endoscopic ultrasonography. In this case, endoscopic ultrasonography findings suggested that oxyntic gland dilatations caused the elevated gastric mucosa, such as gastric cobblestone-like mucosa, from the use of proton-pump inhibitors.

Oral administration of conditioned medium obtained from mesenchymal stem cell culture prevents subsequent stricture formation after esophageal submucosal dissection in pigs.

BACKGROUND AND AIMS: Endoscopic submucosal dissection (ESD) for esophageal cancer often causes postoperative stricture when more than three fourths of the circumference of the esophagus is dissected. Mesenchymal stem cells are a valuable cell source in regenerative medicine, and conditioned medium (CM) obtained from mesenchymal stem cells reportedly inhibits inflammation. In this study we evaluated whether CM could prevent esophageal stricture after ESD. METHODS: We resected a semi-circumference of pig esophagus by ESD. We prepared CM gel by mixing with 5% carboxymethyl cellulose and endoscopically applied it onto the wound bed immediately after ESD and on days 8 and 15 (weekly CM group) or administered it orally from days 1 to 4 (daily CM group). We also injected triamcinolone acetonide into the remaining submucosa immediately after ESD (steroid group). We killed the pigs on day 8 or day 22 to measure the stricture rate and to perform histologic analysis. RESULTS: Stricture rate in weekly and daily CM groups and steroid groups were significantly lower than in the control group on day 22. Moreover, CM significantly attenuated the number of activated myofibroblasts and fiber thickness on day 22. CM also significantly decreased the infiltration of neutrophils and macrophages compared with the control group on day 8. CONCLUSIONS: CM gel prevents esophageal stricture formation by suppressing myofibroblast activation and fibrosis after the infiltration of neutrophils and macrophages. Oral administration of CM gel is a promising treatment for the prevention of post-ESD stricture.

Gastric mucosal cracked and cobblestone-like changes resulting from proton pump inhibitor use.

BACKGROUND AND AIM: Use of proton pump inhibitors (PPI) is histologically associated with oxyntic gland dilatations. Two interesting mucosal changes are often detected endoscopically in patients who use PPI: gastric cracked mucosa (GCM) and gastric cobblestone-like mucosa (GCSM). The aim of the present study was to clarify the relationship between PPI use and these mucosal changes. METHODS: This was a single-center observational study. All successive subjects who underwent a routine esophagogastroduodenoscopy (EGD) between August and November 2014 in Hokkaido University Hospital were enrolled. Endoscopists carried out the assessment blinded to the use of PPI and checked for GCSM and GCM using original diagnostic criteria for GCM and GCSM. Subjects were divided into two groups: those who used PPI (PPI group) and those who did not (control group). Endoscopic findings and backgrounds were compared between the two groups. RESULTS: A total of 538 patients were analyzed (control group: 374 patients, men/women: 204/170, median age: 65.2 years; PPI group: 164 patients, men/women: 89/75, median age: 67.1 years). GCM was detected in 54 (10.0%) subjects, and GCSM was detected in 18 (3.3%) subjects. There was a significant difference in the prevalence rate of GCM between the control group (14/374, 3.7%) and the PPI group (40/164, 24.4%) (P < 0.01). GCSM was significantly more prevalent in the PPI group (15/164, 9.1%) than in the control group (3/374, 0.8%) (P < 0.01). CONCLUSION: Novel GCM and GCSM endoscopic findings in the corpus area seem to be strongly associated with PPI use.

Fluorescent imaging of superficial head and neck squamous cell carcinoma using a γ-glutamyltranspeptidase-activated targeting agent: a pilot study.

BACKGROUND: Detecting superficial head and neck squamous cell carcinoma (HNSCC) by endoscopy is challenging because of limited morphological hallmarks, and iodine cannot be applied to head and neck lesions due to severe mucosal irritation. γ-glutamyltranspeptidase (GGT), a cell surface enzyme, is overexpressed in several cancers, and it has been reported that γ-glutamyl hydroxymethyl rhodamine green (gGlu-HMRG), a fluorescent targeting agent which can be enzymatically activated and becomes fluorescent after cleavage of a GGT-specific sequence, can be activated within a few minutes after application to animal models. We investigated whether early HNSCC can be detected by applying gGlu-HMRG to clinical samples. METHODS: gGlu-HMRG was applied to four HNSCC cell lines, and fluorescence was observed by fluorescence microscopy and flow cytometry. Immunohistological examination was performed in three recent cases of endoscopic submucosal dissection (ESD) to investigate GGT expression. Fluorescence imaging with gGlu-HMRG in eight clinical samples resected by ESD or surgery was performed, and fluorescence intensity of tumor and normal mucosa regions of interest (ROI) was prospectively measured. RESULTS: All four gGlu-HMRG-applied cell lines emitted green fluorescence. Immunohistological examination demonstrated that GGT was highly expressed in HNSCC of the recent three ESD cases but barely in the normal mucosa. Fluorescence imaging showed that iodine-voiding lesions became fluorescent within a few minutes after application of gGlu-HMRG in all eight resected tumors. Tumor ROI fluorescence intensity was significantly higher than in the normal mucosa five minutes after gGlu-HMRG application. CONCLUSIONS: Fluorescence imaging with gGlu-HMRG would be useful for early detection of HNSCC.

Multicenter randomized controlled study to assess the effect of prophylactic clipping on post-polypectomy delayed bleeding.

BACKGROUND AND AIM: Prophylactic clipping has been widely used to prevent post-procedural bleeding in colon polypctomy. However, its efficiency has not been confirmed and there is no consensus on the usefulness of prophylactic clipping. The aim of the present study was to evaluate the preventive effect of prophylactic clipping on post-polypectomy bleeding. METHODS: A multicenter randomized controlled study was conducted from January 2012 to July 2013 in Japan. Patients who had polyps <2 cm in diameter were divided into a clipping group and a non-clipping group by cluster randomization. After endoscopic polypectomy, patients allocated to the clipping group underwent prophylactic clipping, whereas the procedure was completed without clipping in patients allocated to the non-clipping group. Occurrence of post-polypectomy bleeding was compared between the two groups. RESULTS: Seven hospitals participated in this study. A total of 3365 polyps in 1499 patients were evaluated. The clipping group consisted of 1636 polyps in 752 patients, and the non-clipping group consisted of 1729 polyps in 747 patients. Post-polypectomy bleeding occurred in 1.10% (18/1636) of the cases in the clipping group, and in 0.87% (15/1729) of those in the non-clipping group. The difference was -0.22% (95% confidence interval [CI]: -0.96, 0.53). Upper limit of the 95% CI was lower than the non-inferiority margin (1.5%), and we could thus prove non-inferiority of non-clipping against clipping. CONCLUSION: Prophylactic clipping is not necessary to prevent post-polypectomy bleeding for polyps <2 cm in diameter.

Symmetry protected topological superfluid (3)He-B.

Owing to the richness of symmetry and well-established knowledge of bulk superfluidity, the superfluid (3)He has offered a prototypical system to study intertwining of topology and symmetry. This article reviews recent progress in understanding the topological superfluidity of (3)He in a multifaceted manner, including symmetry considerations, the Jackiw-Rebbi's index theorem, and the quasiclassical theory. Special focus is placed on the symmetry protected topological superfuidity of the (3)He-B confined in a slab geometry. The (3)He-B under a magnetic field is separated to two different sub-phases: the symmetry protected topological phase and non-topological phase. The former phase is characterized by the existence of symmetry protected Majorana fermions. The topological phase transition between them is triggered by the spontaneous breaking of a hidden discrete symmetry. The critical field is quantitatively determined from the microscopic calculation that takes account of magnetic dipole interaction of the (3)He nucleus. It is also demonstrated that odd-frequency even-parity Cooper pair amplitudes are emergent in low-lying quasiparticles. The key ingredients, symmetry protected Majorana fermions and odd-frequency pairing, bring an important consequence that the coupling of the surface states to an applied field is prohibited by the hidden discrete symmetry, while the topological phase transition with the spontaneous symmetry breaking is accompanied by anomalous enhancement and anisotropic quantum criticality of surface spin susceptibility. We also illustrate common topological features between topological crystalline superconductors and symmetry protected topological superfluids, taking UPt3 and Rashba superconductors as examples.