Giant impurity effect on anomalous Hall effect of Mn3Sn.

Mn3Sn is an anomalous Hall effect (AHE) antiferromagnet that exhibits the hysteretic AHE in antiferromagnetic (AFM) phase at room temperature. We report that whisker Mn3Sn crystals grown by the flux method exhibit a non-hysteretic AHE at mid-to-low temperatures when the whisker Mn3Sn is surrounded by a thin layer of ferromagnetic Mn2-xSn. These crystals exhibit a hysteretic AHE above 275 K due to the spin alignment of the inverse triangular lattice, which is similar to other crystals. However, upon cooling the crystal, it exhibits a non-hysteretic AHE with a spiral AFM spin structure at 100-200 K. We concluded that the non-hysteretic AHE is induced at the interface of Mn2-xSn/Mn3Sn. We believe that the scalar-spin chirality in the spiral AFM phase of Mn3Sn, modulated by Mn2-xSn through the magnetic proximity effect, produces the AHE. This discovery opens a new avenue for tailoring the AHE by magnetic layers.

Real-time high-spectral-resolution mid-infrared spectroscopy with a signal-to-noise ratio of ten thousand.

We developed a mid-infrared spectroscopy system with high spectral resolution and a high signal-to-noise ratio using an extremely high-order germanium immersion grating. The spectroscopic system covers wavelengths from 3 to 5 µm and has a spectral resolution of 1 GHz with a single-shot bandwidth of 2 THz. We proposed a method of improving the signal-to-noise ratio and achieved a ratio of over 3000 with a data acquisition rate of 125 Hz in the presence of fluctuations in the light source and environment. A signal-to-noise ratio of 10,000 was achieved with 0.1-s integration for 100-µW mid-infrared light.

The Usefulness of Video Capsule Endoscopy in Evaluating Gastrointestinal Manifestations of Immunoglobulin A Vasculitis.

Objective Immunoglobulin (Ig) A vasculitis (IgAV) is a systemic vasculitis characterized by purpura and gastrointestinal involvement showing abdominal pain that usually occurs after the emergence of purpura. Criteria for evaluating gastrointestinal manifestations of IgAV are unavailable at present, so we conducted a study to investigate the usefulness of video capsule endoscopy (VCE) for detecting gastrointestinal manifestations of IgAV. Methods The clinical data of 10 patients who underwent VCE for IgAV at our hospital from 2012 to 2017 were collected. Nine patients underwent esophagogastroduodenoscopy, and five underwent colonoscopy. We compared the endoscopic severity determined by VCE to the findings of esophagogastroduodenoscopy and colonoscopy. Results The rates of positive findings of esophagogastroduodenoscopy, VCE, and colonoscopy were 56%, 100%, and 80%, respectively. In 70% of cases, the most severe gastrointestinal findings were detected by VCE. VCE was performed on average 16.8 days after the emergence of purpura, and in 8 of 10 patients, its result triggered the initiation of steroid therapy or the control of the steroid dose. Conclusion VCE is very useful for confirming gastrointestinal involvement in IgAV and may be used to determine the timing of steroid therapy initiation. We recommend performing VCE when IgAV is suspected in patients with gastrointestinal symptoms.

Acute Small Bowel Perforation Caused by Obstruction of a Novel Tag-Less AgileTM Patency Capsule.

A 74-year-old man visited our hospital complaining of abdominal pain. An abdominal computed tomography scan showed multiple wall thickness of the small bowel. Capsule endoscopy was recommended for further evaluation, and patency capsule examination was performed. Eighteen hours after patency capsule ingestion, he experienced small bowel perforation with severe peritonitis caused by intestinal pressure rising because of the patency capsule trapped in his terminal ileum. An ileocolic resection was performed, including the removal of the sclerotic ileum as an emergency surgery. A pathological examination showed transmural inflammation and multiple ulcers with perforation of the small intestine, consistent with Crohn's disease. Here, we report a rare and valuable case of novel tag-less AgileTM patency capsule (Given Imaging Ltd., Yoqneam, Israel) retention leading to small bowel perforation.

Duplication cyst of the ileum presenting with severe anemia detected by double-balloon endoscopy.

Background and study aims Duplication cysts of the ileum are rare and present with non-specific clinical manifestations such as abdominal pain, vomiting, melena, and intussusception. Therefore, preoperative diagnosis is difficult. Here, we report a case of duplication cyst of the small intestine that was diagnosed preoperatively using double-balloon enteroscopy. A 19-year-old man presented with severe iron deficiency anemia, abdominal pain, and exertional dyspnea. Gastroscopy and colonoscopy revealed no remarkable findings. Abdominal computed tomography revealed a cystic structure in the ileum. Therefore, we performed double-balloon enteroscopy via the anal route. The intestinal tract was bifurcated, with one segment ending in a blind sac containing normal villi and an ulceration. Tc-99 m pertechnetate scintigraphy showed no accumulation in the lesion. Accordingly, we diagnosed a duplication cyst and suspected that this was the cause of severe anemia. Following small bowel resection with cyst excision and anastomosis, the anemia and presenting symptoms resolved. This report highlights the usefulness of double-balloon enteroscopy of the small intestine for preoperative diagnosis of the obscure gastrointestinal bleeding, including duplication cysts .

Identification of novel variants in HLA class II region related to HLA DPB1 expression and disease progression in patients with chronic hepatitis C.

Recent genome-wide studies have demonstrated that HLA class II gene may play an important role in viral hepatitis. We studied genetic polymorphism and RNA expression of HLA class II genes in HCV-related liver diseases. The study was performed in groups consisting of 24 patients with HCV-related liver disease (12 of persistent normal ALT: PNALT group and 12 of advanced liver disease: ALD group) and 26 patients without HCV infection (control group). In PBMC samples, RNA expression of HLA class II genes (HLA-DPA1, DPB1, DQA1, DQB1, and DRB1) was analyzed by real-time RT-PCR. Furthermore, 22 single nucleotide polymorphisms (SNPs) in HLA class II gene and two SNPs in IL28B gene were genotyped by genetic analyzer (GENECUBE®). In expression analysis, only DPB1 level was significantly different. Mean expression level of DPB1gene in control group was 160.0, PNALT group 233.8, and ALD group 465.0 (P < 0.01). Of 24 SNPs, allele frequencies were statistically different in two SNPs (rs2071025 and rs3116996) between PNALT groups and ALD group (P < 0.01). In rs2071025, TT genotype was frequently detected in ALD group and expression level was significantly higher than the other genotypes (449.2 vs 312.9, P < 0.01). In rs3116996, TA or TT (non AA) genotype was frequently detected in ALD group and expression level was significantly higher than genotype AA (457.1 vs 220.9, P < 0.01). Genotyping and expression analysis in HLA class II gene revealed that two SNPs of HLA-DPB1 (rs2071025 and rs3116996) were significantly correlated to RNA expression and progression of HCV-related liver diseases.

Long-Term Endoscopic Follow-Up of Patients with Chronic Radiation Proctopathy after Brachytherapy for Prostate Cancer.

Background. Chronic radiation proctopathy (CRP) is late toxicity and associated with morbidity. Aim. To investigate the predictors of prognosis in patients with CRP after brachytherapy (BT). Methods. One hundred four patients with prostate cancer were treated with BT or BT followed by external-beam radiotherapy (BT + EBRT). We retrospectively investigated the 5-year incidence of rectal bleeding and endoscopic findings of CRP using the Vienna Rectoscopy Score (VRS). Twenty patients with VRS ≥ 1 were divided into the improved VRS group without treatment, unchanged VRS group, and treated group. The parameters associated with alteration of VRS were analyzed. Results. The incidence of rectal bleeding was 24%. The risk of rectal bleeding was higher in patients treated with BT + EBRT compared to those treated with BT (p < 0.0001). The incidence of superficial microulceration was higher in the improved VRS group than in the unchanged VRS group (p < 0.05). The incidence of multiple confluent telangiectasia or superficial ulcers > 1 cm(2) was higher in the treated group than in both the improved and unchanged VRS groups (p < 0.05). Conclusions. Patients treated with BT + EBRT have a high risk of CRP. Endoscopic findings were useful for prognostic prediction of CRP.

Effect of green tea catechins on gastric mucosal dysplasia in insulin-gastrin mice.

Green tea catechins (GTCs) have been implicated in various physiological effects, including anti-carcinogenic activities. In the present study, we evaluated the effects of GTCs specifically on the development of gastritis and pre-malignant lesions in insulin-gastrin mice. Nine-week-old male INS-GAS mice (n=38) were supplemented with GTCs for 4 and 28 weeks, and their body weights, serum gastrin levels, histopathology and pro-inflammatory cytokine levels in gastric tissue and mucosal cell proliferation were monitored. Body weights of the GTC-treated mice were significantly lower than those of the untreated controls (P≤0.05). Serum gastrin levels were suppressed at the age of 37-weeks (P≤0.05). The histopathological scores indicated that the extent of dysplasia was significantly diminished (P≤0.05), although GTC supplementation did not affect the inflammation scores. The messenger RNA levels of interferon (IFN)-γ were significantly reduced at the age of 13 weeks (P≤0.05), although the changes did not reach statistical significance at the age of 37 weeks (P=0.056). The labeling index of Ki-67 immunohistochemistry was significantly decreased (P≤0.05). These results demonstrated that GTCs may play a protective role in the development of gastritis and pre-malignant lesions via an IFN-γ, gastrin, and mucosal cell proliferation-dependent mechanism in this rodent model and potentially in humans.

Preoperative diagnosis of cavernous hemangioma presenting with melena using wireless capsule endoscopy of the small intestine.

BACKGROUND AND STUDY AIMS: Primary neoplasms of the small intestine are relatively rare in all age groups, accounting for about 5 % of all gastrointestinal tumors 1. Cavernous hemangiomas of the small intestine are also rare, can cause gastrointestinal bleeding, and are extremely difficult to diagnose preoperatively 2. We present a patient who presented with melena and iron deficiency anemia, for whom wireless capsule endoscopy and single-balloon enteroscopy facilitated the diagnosis of cavernous hemangioma.

[The Usefulness of Strain Elastography for Determining Liver Fibrosis Stage in Chronic Viral Hepatitis: An Analysis Using Tissue Doppler Imaging with Manual Compression].

BACKGROUND/AIM: Accurate determination of the stage of liver fibrosis is an essential component in choice of treatment and assessment of cancer risk in patients with chronic viral hepatitis. The aim of this study was to evaluate the usefulness of strain elastography based on tissue Doppler imaging for liver fibrosis in chronic viral hepatitis. METHODS: A total of 37 patients with chronic viral hepatitis and 8 healthy volunteers were enrolled. Strain value was measured by using a conventional ultrasound machine that included strain imaging technolo- gy. Strain elastography was performed at the right subcostal area with manual compression. Liver fibrosis stages were assessed by using liver biopsy and compared with strain values. Diagnostic performance of the strain value for fibrosis stage 4, cirrhosis, was determined by performing a receiver-operating characteristics (ROC) curve analysis. RESULTS: Twenty-seven patients were positive for HCV RNA, 9 were positive for HBs antigen, and 1 was positive for both (Fibrosis stage F1, n=11; F2, n=7; F3, n=15; F4, n=4). The strain value of F3 and F4 was 0.066±0.02 and 0.042±0.011, respectively. These strain Values were significantly lower compared to those of healthy volunteers (0.112 ±0.018) (P< 0.05). Using a cutoff value of 0.042, the area under ROC curve was 0.88 for the diagnosis of F4. The sensitivity, specificity, positive predictive value, and negative predictive value were 75%, 92%, 50%, and 94%, respectively. CONCLUSIONS: Strain elastography based on tissue Doppler imaging with manual compression appears to be a useful tool to diagnose cirrhosis in patients with chronic viral hepatitis. [Original].

Pituitary metastasis of hepatocellular carcinoma presenting with panhypopituitarism: a case report.

BACKGROUND: Metastasis to the pituitary gland is extremely rare and is often detected incidentally by symptoms associated with endocrine dysfunction. Breast and lung cancer are the most common primary metastasizing to pituitary gland. Metastasis from hepatocellular carcinoma to the pituitary gland is extremely rare, with only 10 cases having been previously reported. We present here the first case of pituitary metastasis of hepatocellular carcinoma presenting with panhypopituitarism diagnosed by magnetic resonance imaging. CASE PRESENTATION: We report the case of an 80-year-old Japanese woman who presented with the sudden onset of hypotension and bradycardia after having previously been diagnosed with hepatocellular carcinoma. Based on low levels of pituitary hormones, she was diagnosed with panhypopituitarism caused by metastasis of the hepatocellular carcinoma to the pituitary gland. Magnetic resonance imaging with arterial spin-labeling was effective in the differential diagnosis of the intrasellar tumor. The patient died despite hormone replacement therapy because of hypovolemic shock. CONCLUSION: Metastasis to the pituitary gland causes various non-specific symptoms, so it is difficult to diagnose. The present case emphasizes the importance of diagnostic imaging in identifying these metastases. Clinicians should consider the possibility of pituitary metastasis in patients with malignant tumors who demonstrate hypopituitarism.

Ruptured hepatic metastases of cutaneous melanoma during treatment with vemurafenib: an autopsy case report.

BACKGROUND: The spontaneous rupture of hepatic metastases is rare compared to that of primary hepatic tumors. In addition, vemurafenib, a selective inhibitor of the mutant BRAF protein or gene product, has been reported to be extremely effective in patients with metastatic melanoma who harbor a BRAF V600E mutation. CASE PRESENTATION: A 44-year-old female had previously undergone surgery for resection of a malignant melanoma in the lower right leg. Four years later, hepatic metastases became apparent, and transcatheter arterial embolization (TAE) was performed. Then she underwent treatment with vemurafenib. The size of the hepatic metastases markedly decreased. Two months later, they enlarged rapidly and ruptured, requiring emergency TAE. However, the patient developed hemorrhagic shock and died of renewed intra-abdominal bleeding on the 26th postoperative day. CONCLUSIONS: This is a rare case of ruptured hepatic metastases of malignant melanoma during treatment with vemurafenib. Postmortem examination and immunohistochemical analysis indicated reactivation of the mitogen-activated protein kinase pathway in the metastatic tumor, suggesting secondary resistance to vemurafenib as the possible underlying mechanism.

A case of Helicobacter pylori-negative intramucosal well-differentiated gastric adenocarcinoma with intestinal phenotype.

A woman in her 30s visited our hospital with stool abnormality. Esophagogastroduodenoscopy revealed a depressed lesion on the greater curvature of the gastric antrum. The tumor was diagnosed as a well-differentiated tubular adenocarcinoma based on the analysis of the biopsy specimen. The rapid urease test, histological examination, and serum anti-Helicobacter pylori antibody indicated that the patient was Helicobacter pylori negative. Gastric mucosal atrophy was not evident on esophagogastroduodenoscopy. Complete cure en bloc resection was successfully performed. The tumor was confined to the mucosa (pT1a-M). Immunohistochemistry showed positive CD10, MUC2, and CDX2 expression and negative MUC5AC and MUC6 expression. Thus, the phenotype was diagnosed as the intestinal phenotype. Helicobacter pylori-negative, well-differentiated early gastric cancer with intestinal phenotype has not been previously reported. Here, we report a rare and valuable case of Helicobacter pylori-negative early gastric cancer with intestinal phenotype treated by endoscopic submucosal dissection.

Comparison of hepatic arterial infusion chemotherapy and sorafenib in elderly patients with advanced hepatocellular carcinoma: A case series.

Sorafenib and hepatic arterial infusion chemotherapy (HAIC) are both indicated for unresectable hepatocellular carcinoma (HCC). In this study, we compared the efficacy and safety of HAIC to that of sorafenib in elderly patients with HCC. Eligible patients included those aged ≥70 years, with histologically or clinically confirmed advanced HCC. A total of 12 patients received sorafenib (800 mg per day) and 8 patients received HAIC with 5-fluorouracil (300 mg/m2 on days 1-5 and 8-12) with or without cisplatin (20 mg/m2 on days 1 and 8), with interferon-α (3 times per week for 4 weeks). The response rate was significantly higher in patients treated with HAIC (37.5%) compared to that in patients treated with sorafenib (no response). The median overall survival (18.6 and 11.7 months) and progression-free survival (4.0 and 5.0 months) were similar between the sorafenib and HAIC groups, respectively. In the sorafenib group, 58.3% of the patients discontinued treatment compared to none in the HAIC group. The most frequent adverse event leading to discontinuation of sorafenib was anorexia. Similar to sorafenib, HAIC appears to be a feasible treatment and may also have the advantage of an adequate safety profile for elderly patients with advanced HCC. Further study of HAIC in a larger population of elderly patients is required to assess its potential as an alternative to sorafenib for HCC.

[A case of superficial esophageal basaloid squamous cell carcinoma resected by endoscopic submucosal dissection].

A woman in her 70s visited our hospital to undergo endoscopy. Esophagogastroduodenoscopy showed a white submucosal tumor-like lesion in the upper esophagus. Analysis of a biopsy specimen revealed that the tumor was a basaloid squamous cell carcinoma. A superficial squamous cell carcinoma was also revealed near the basaloid squamous cell carcinoma before endoscopic submucosal dissection. Curative en bloc resection was successfully performed. Histopathological examination revealed that the basaloid and superficial squamous cell carcinomas had invaded the lamina propria (pT1a-LPM) and epithelium (pT1a-EP), respectively. In addition, the basaloid squamous cell carcinoma had two different components in terms of malignancy and differentiation. Here we report a rare case of esophageal basaloid squamous cell carcinoma resected by endoscopic submucosal dissection.

The effects of Helicobacter pylori eradication on body mass index and dyspeptic symptoms.

BACKGROUND AND AIM: The relationship between Helicobacter pylori infection and body mass index (BMI) and dyspeptic symptoms is controversial. We investigated the changes in BMI and dyspeptic symptoms after H. pylori eradication among stages of atrophic gastritis classified according to the serum pepsinogen (PG) I/II ratio. METHODS: One hundred and sixty-three H. pylori-positive patients underwent eradication therapy for H. pylori. Serum PG I and II concentrations were measured before treatment, and the PG I/II ratio was classified into three groups: PG I/II ratio <2.0, PG I/II ratio >or=2.0 and <4.0, and PG I/II ratio >or=4.0 were considered to be low, middle, and high, respectively. Their BMI and abdominal symptoms were checked before, 1 and 5 years after treatment, and these changes were investigated among the three groups. RESULTS: The mean BMI changes 1 year after treatment in the low PG I/II ratio group were significantly higher than those in other groups. Most abdominal symptoms in the high PG I/II ratio group were most severe before eradication but improved significantly after eradication. CONCLUSIONS: The effects of H. pylori eradication on BMI and dyspeptic symptoms may be different according to the serum PG I/II ratio before eradication.

Relationship between the diversity of the cagA gene of Helicobacter pylori and gastric cancer in Okinawa, Japan.

BACKGROUND: Helicobacter pylori CagA protein is considered to be one of the virulence factors associated with gastric cancer. CagA is injected into gastric epithelial cells, undergoes tyrosine phosphorylation, and binds to Src homology 2 domain-containing protein-tyrosine phosphatase (SHP-2). Two major subtypes of CagA have been observed in the SHP-2-binding site, the Western and East Asian types. The East Asian-type CagA binds to SHP-2 more strongly than the Western-type CagA. The diversity of CagA, which collectively determines the binding affinity of CagA to SHP-2, may be an important variable in determining the clinical outcome of infection by different H. pylori strains. METHODS: We investigated the relationship between the diversity of CagA and clinical outcome in Okinawa, Japan. A total 24 strains, 13 gastric cancer strains and 11 duodenal ulcer strains, were studied. We sequenced full-length cagA genes and analyzed the phylogenetic relationships between Okinawa isolates and previously characterized Western H. pylori strains. RESULTS: All isolates examined were cagA positive. The prevalence of East Asian CagA-positive strains was significantly higher in patients with gastric cancer (84.6%) than in patients with duodenal ulcer (27.3%) (chi-squared = 8.06, P = 0.011). The phylogenetic analysis showed that all gastric cancer strains with East Asian-type CagA were in the East Asian cluster, and that most duodenal ulcer strains were in the Western cluster. CONCLUSIONS: The origins of H. pylori isolates are different between gastric cancer strains and duodenal ulcer strains, and East Asian CagA-positive H. pylori infection is associated with gastric cancer. The strain diversity observed in Okinawa may affect the difference in the prevalence of disease associated with H. pylori infection in Japan.

Association between interleukin-1beta-511C/T polymorphism and reflux esophagitis in Japan.

BACKGROUND: Interleukin-1beta (IL-1beta) gene polymorphisms are related to hypochlorhydria and increase the risk of gastric cancer in the presence of Helicobacter pylori infection. However, little information is available about the genetic risk factors of reflux esophagitis. In this study we investigated its association with the IL-1beta polymorphisms. METHODS: We examined 48 patients with reflux esophagitis and 96 control subjects, 89 with gastric cancer. IL-1beta-511C/T genotyping was performed by the polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP) method. RESULTS: The frequency of IL-1beta-511T alleles was significantly higher in reflux esophagitis patients (57.3%) than in controls (41.1%) (P = 0.0215, chi(2) = 5.289). The frequency of IL-1beta-511T/T genotypes was also significantly higher in reflux esophagitis patients (31.3%) than in controls (15.6%). The odds ratio and the 95% confidence interval were 4.000 and 1.393-11.486, respectively. The frequency of IL-1beta-511T/T genotypes was significantly higher in reflux esophagitis patients (31.3%) than in gastric cancer patients (21.4%). The odds ratio and the 95% confidence interval were 2.961 and 1.054-8.316, respectively. CONCLUSIONS: IL-1beta-511T was associated with reflux esophagitis having hyperacidity. Differences of genetic background regarding gastric acid secretion may exist between Japanese and Caucasians.

Distinct diversity of vacA, cagA, and cagE genes of Helicobacter pylori associated with peptic ulcer in Japan.

Colonization of the stomach mucosa by Helicobacter pylori is a major cause of acute and chronic gastric pathologies in humans. Several H. pylori virulence genes that may play a role in its pathogenicity have been identified. The most important determinants are vacA and cagA in the cag pathogenicity island (cagPAI) genes. In the present study, to consider the association of molecular genetics between vacA and the cagPAI regarding clinical outcome, we selected H. pylori strains with various genotypes of vacA in Japan and sequenced full-length vacA, cagA, and cagE genes. Sequencing of vacA and cagA genes revealed variable size, whereas the cagE gene was well conserved among strains. Each of the phylogenetic trees based on the deduced amino acid sequences of VacA, CagA, and CagE indicated that all three proteins were divided into two major groups, a Western group and an East Asian group, and the distributions of isolates exhibited similar patterns among the three proteins. The strains with s2 and s1a/m1a vacA genotypes and the Western-type 3' region cagA genotype were classified into the Western group, and the strains with the s1c/m1b vacA genotype and the East Asian-type 3' cagA genotype were included in the East Asian group. In addition, the prevalence of infection with the Western group strain was significantly higher in patients with peptic ulcer (90.0%, 9/10) than in patients with chronic gastritis (22.7%, 5/22) (chi2 = 12.64, P = 0.00057). These data suggest that the molecular genetics of vacA and cagPAI are associated and that the Western group with vacA and cagPAI genes is associated with peptic ulcer disease.