Curved Flats, Pluriharmonic Maps and Constant Curvature Immersions into Pseudo-Riemannian Space Forms

We study two aspects of the loop group formulation for isometric immersions with flat normal bundle of space forms. The first aspect is to examine the loop group maps along different ranges of the loop parameter. This leads to various equivalences between global isometric immersion problems among different space forms and pseudo-Riemannian space forms. As a corollary, we obtain a non-immersibility theorem for spheres into certain pseudo-Riemannian spheres and hyperbolic spaces. The second aspect pursued is to clarify the relationship between the loop group formulation of isometric immersions of space forms and that of pluriharmonic maps into symmetric spaces. We show that the objects in the first class are, in the real analytic case, extended pluriharmonic maps into certain symmetric spaces which satisfy an extra reality condition along a totally real submanifold. We show how to construct such pluriharmonic maps for general symmetric spaces from curved flats, using a generalised DPW method.Comment: 21 Pages, reference adde

Geometry and Integrability of Topological-Antitopological Fusion

Integrability of equations of topological-antitopological fusion (being proposed by Cecotti and Vafa) describing ground state metric on given 2D topological field theory (TFT) model, is proved. For massive TFT models these equations are reduced to a universal form (being independent on the given TFT model) by gauge transformations. For massive perturbations of topological conformal field theory models the separatrix solutions of the equations bounded at infinity are found by the isomonodromy deformations method. Also it is shown that ground state metric together with some part of the underlined TFT structure can be parametrized by pluriharmonic maps of the coupling space to the symmetric space of real positive definite quadratic forms.Comment: 30 pages, plain TEX, INFN-8/92-DS

Relationship between period of survival and clinicopathological characteristics in patients with colorectal liver metastasis

AIM: Cancer death in the early period after hepatectomy still occurs in patients with colorectal liver metastasis (CLM). We examined the relationship between clinicopathological parameters and survival periods in 130 CLM patients who underwent hepatectomy. PATIENTS/METHODS: Patients were divided into four groups: Group 1 (5-year survivors without tumor relapse), Group 2 (survivors at 2-5years), Group 3 (cancer death at 2-5years), and Group 4 (cancer death within 2years). RESULTS: A short surgical margin was frequent in Group 4 compared to Group 1 (31 vs. 78%, P<0.05). Primary node-positive status, absence of fibrous pseudo-capsular formation, higher Clinical Risk Score, and tumor recurrence within 12months were frequent in Group 4 (P<0.05). Multivariate analysis revealed a short surgical margin (HR; 3.5) and early tumor relapse (HR; 5.9) as independently significant related parameters (P<0.05). CONCLUSIONS: Sufficient surgical margins and careful follow-up for early tumor relapse may be important for improving postoperative outcomes for CLM patients

Early stage signet ring cell carcinoma of the colon examined by magnifying endoscopy with narrow-band imaging: a case report

Background: Signet ring cell carcinoma of the colon and rectum is rare, and most cases are detected at an advanced stage. We present a case of primary signet ring cell carcinoma detected at an early stage by magnifying endoscopy with narrow-band imaging (NBI) and crystal violet staining. Case presentation: A 73-year-old man visited our hospital for screening colonoscopy. Six years previously, he had undergone endoscopic submucosal dissection (ESD) for early gastric cancer. The pathological diagnosis was a well-differentiated adenocarcinoma, invading into the mucosa without lymphovascular invasion. Colonoscopy revealed a flat elevated lesion with a slightly depressed area, 20 mm in diameter, in the cecum. Further, magnifying endoscopy with NBI revealed that the surface pattern was slightly irregular and microvessels had a regular diameter and distribution in the margin of the lesion, but in the central part of the lesion, irregularity in the tumor surface pattern and form as well as in the diameter and distribution of microvessels was noted. Additionally, due to mucus, avascular areas were also observed. Magnifying endoscopy combined with 0.05 % crystal violet staining showed IIIL and VI pit patterns in the margin of the lesion, and a VI pit pattern in the central part of the lesion; however, due to mucus exudate, this finding could not be established with certainty. The lesion was successfully removed en bloc using ESD without complications. The tumor was composed mainly of signet ring cell carcinoma, partially mixed with moderately differentiated (tub2) and well-differentiated (tub1) adenocarcinomas. The tumor cells infiltrated 250 μm into the submucosal layer and involved lymphatic vessels. Therefore, the patient underwent an additional laparoscopic ileocecal resection, and the resected specimen revealed no residual carcinoma or lymph node metastasis. Conclusion: In this case report, we present a case of primary signet ring cell carcinoma detected at an early stage and identified by magnifying endoscopy with NBI and crystal violet staining

Attenuation of Helicobacter pylori-induced gastric inflammation by prior cag− strain (AM1) infection in C57BL/6 mice

Helicobacter pylori, colonize in stomach of ~50% of the world population. cag pathogenicity Island of H. pylori is one of the important virulent factors that attributed to gastric inflammation. Coinfection with H. pylori strain with different genetic makeup alters the degree of pathogenicity and susceptibility towards antibiotics. The present study investigates host immunomodulatory effects of H. pylori infection by both cag+ strain (SS1) and cag− strain (AM1). C57BL/6 mice were infected with AM1 or SS1 strain as well as AM1 followed by SS1 (AM1/SS1) and vice versa. Results: Mice infected with AM1/SS1 strain exhibited less gastric inflammation and reduced proMMP9 and proMMP3 activities in gastric tissues as compared to SS1/SS1 and SS1/AM1 infected groups. The expression of both MMP9 and MMP3 followed similar trend like activity in infected tissues. Both Th1 and Th17 responses were induced by SS1 strain more profoundly than AM1 strain infection which induced solely Th1 response in spleen and gastric tissues. Moreover, IFN-γ, TNF-α, IL-1β and IL-12 were significantly downregulated in mice spleen and gastric tissues infected by AM1/SS1 compared to SS1/SS1 but not with SS1/AM1 coinfection. Surprisingly, IL-17 level was dampened significantly in AM1/ SS1 compared to SS1/AM1 coinfected groups. Furthermore, number of Foxp3+ T-regulatory (Treg) cells and immunosuppressive cytokines like IL-10 and TGF-β were reduced in AM1/SS1 compared to SS1/SS1 and SS1/AM1 coinfected mice gastric tissues. Conclusions: These data suggested that prior H. pylori cag− strain infection attenuated the severity of gastric pathology induced by subsequent cag+ strain in C57BL/6 mice. Prior AM1 infection induced Th1 cytokine IFN-γ, which reduced the Th17 response induced by subsequent SS1 infection. The reduced gastritis in AM1/SS1-infected mice might also be due to enrichment of AM1- primed Treg cells in the gastric compartment which inhibit Th1 and Th17 responses to subsequent SS1 infection. In summary, prior infection by non-virulent H. pylori strain (AM1) causes reduction of subsequent virulent strain (SS1) infection by regulation of inflammatory cytokines and MMPs expressio

High Serum Vaspin Concentrations in Patients with Ulcerative Colitis

Background: Adipocytokines are associated with energy homeostasis and mediate various immune responses and inflammatory processes. Vaspin is a novel adipocytokine that is thought to exhibit anti-inflammatory effects. Aim: We aimed to evaluate serum vaspin levels in inflammatory bowel disease (IBD) and determine its possible associations with the course and to clarify its intestinal localization. Methods: Serum samples were obtained from patients with Crohn\u27s disease (CD; n = 30) and ulcerative colitis (UC; n = 33) and from healthy volunteers (controls; n = 26). Enzyme-linked immunosorbent assays were performed for all patients. Vaspin immunohistochemical staining was performed for intestines affected with IBD. Results: Serum vaspin concentrations were significantly higher in patients with UC than in patients with CD and controls (422.9 ± 361.9 vs. 163.4 ± 116.2 vs. 147.5 ± 89.4 pg/mL, respectively; P < 0.01). There was no difference in the serum vaspin concentrations between the patients with CD and controls. There was also no difference in the serum vaspin concentrations between the patients with active IBD and those with inactive IBD. However, the serum vaspin concentrations of most patients with UC increased after remission induction. Vaspin was expressed in the adipocytes of the mesenteric adipose tissues but not in the epithelial or inflammatory cells of large intestines of the patients with IBD. Conclusions: Serum vaspin concentrations are elevated in patients with UC and increase further after remission induction, suggesting that vaspin may aid the auxiliary diagnosis of UC and may be useful for assessing disease activity in patients

Background Coloration of Squamous Epithelium in Esophago-Pharyngeal Squamous Cell Carcinoma: What Causes the Color Change?

Objectives: This study aims to clarify the cause of background coloration in the epithelia between each dilated intra papillary capillary loop in esophago-pharyngeal squamous cell carcinoma. Design: This is a single center retrospective study including 124 patients with 160 lesions who underwent esophagogastroduodenoscopy in Nagasaki University Hospital from September 2007 to March 2012; a detailed comparison between endoscopic images and pathology was performed. Immunohistological assessment using anti-human hemoglobin antibody (anti-Hb Ab) was performed to verify the presence of hemoglobin (Hb) component in the cancer cells. Real-time polymerase chain reaction (RT-PCR) and in situ hybridization (ISH) on Hb-β mRNA were performed to assess the production of Hb component within the cancer cells. Results: A strong positivity for anti-Hb Ab was observed in the squamous cell carcinoma area, whereas non-cancerous mucosa showed no immunopositivity for Hb. The concordance rate between anti-Hb Ab immunoreactivity and the presence of BC was as high as 80.9%. The amount of Hb-β mRNA expression was three times higher in cancer tissues compared with the surrounding non-cancerous mucosa. ISH images showed that the expression exclusively occurred in cancer cells, indicating that Hb is probably produced within cancer cells. Conclusions: The background coloration observed is partly due to an extravascular component of Hb. RT-PCR and ISH analyses indicate that Hb is produced within cancer cells

Improvement of endocytoscopic findings after per oral endoscopic myotomy (POEM) in esophageal achalasia; does POEM reduce the risk of developing esophageal carcinoma? Per oral endoscopic myotomy, endocytoscopy and carcinogenesis

Background: Per oral endoscopic myotomy (POEM) has been reported to be a new therapeutic option for esophageal achalasia. The possibility that POEM could reduce the risk of developing esophageal squamous cell carcinoma was evaluated.Methods: This was a single-centre, retrospective study. Fifteen consecutive patients with esophageal achalasia who underwent POEM in our institution between August 2010 and January 2012 were enrolled. Ultra-high magnification with endocytoscopy was performed, and both histopathological and immunohistochemical evaluations for Ki-67 and p53 were assessed before and 3 months after POEM.Results: POEM was successfully performed and effectively released the dysphagia symptom in all patients without severe complications. Subjective symptoms (mean Ekcardt score, before 7.4 vs. after 0.5, p<0.05) and manometric pressure studies (mean lower esophageal sphincter pressure), before 82.7 vs. after 22.9 mmHg, p<0.05) showed substantial improvement following POEM. The average numbers of esophageal epithelial nuclei before and after POEM on endocytoscopic images were 128.0 and 78.0, respectively (p<0.05). The mean Ki-67-positive ratio was 26.0 (median 25.4, range, 10.3-33.2) before and 20.7 (median 20.0, 13.1-29.9; p=0.07) after POEM, and the mean p53-positive ratio was 2.35 (median 2.61, 0.32-4.23) before and 0.97 (median 1.49, 0.32-1.56; p<0.05) after POEM. A significant positive correlation was seen between the number of nuclei and the Ki-67-positive ratio (p<0.05).Conclusions: POEM appears to be an effective and less invasive treatment of choice against achalasia and may reduce the risk of esophageal carcinogenesis. Endocytoscopy can be useful for the assessment of esophageal cellular proliferation

Impact of hepatitis C virus genotype-4 eradication following direct acting antivirals on liver stiffness measurement

Mohammed Tag-Adeen,1,2 Ahlam Mohamed Sabra,1 Yuko Akazawa,2 Ken Ohnita,2 Kazuhiko Nakao2 1Department of Internal Medicine, Qena School of Medicine, South Valley University, Qena, Egypt; 2Department of Gastroenterology and Hepatology, Nagasaki School of Biomedical Sciences, Nagasaki University, Nagasaki, Japan Background: Liver fibrosis is the most important prognostic factor in chronic hepatitis C virus (HCV) patients, and Egypt shows the highest worldwide HCV prevalence with genotype-4 predominance. The aim of this study was to investigate the degree of liver stiffness measurement (LSM) improvement after successful HCV eradication.Patients and methods: The study included 84 chronic HCV Egyptian patients, and was conducted at Qena University Hospital from November 1, 2015 till October 31, 2016. LSM was obtained by FibroScan&reg; before starting direct acting antiviral (DAA) treatment and after achieving sustained virologic response-24 (SVR-24). Based on baseline LSM, patients were stratified into F0&ndash;F1, F2, F3 and F4 groups (METAVIR). LSM and laboratory data after achieving SVR-24 was compared with that before starting therapy in each fibrosis group (F0-F4), p-value &lt;0.05 was statistically significant.Results: Following DAA treatment, 80 patients achieved SVR-24; of these, 50 were males (62.5%), mean age: 54.2&plusmn;7.6 years, and mean body mass index: 28.6&plusmn;2.2 kg/m2. Mean baseline LSM dropped from 15.6&plusmn;10.8 to 12.1&plusmn;8.7 kPa post-SVR; the maximum change of &minus;5.8 occurred in F4 versus &minus;2.79, &minus;1.28 and +0.08 in F3, F2 and F0&ndash;F1 respectively (p&lt;0.0001). At baseline, 41 patients were in the F4 group; only 16 (39%) regressed to non-cirrhotic range (&lt;12.5&nbsp;kPa), while 25 (61%) were still cirrhotic despite achieving SVR-24 (p&lt;0.0001). Patients who achieved LSM improvement (n=64) have had significantly higher baseline aspartate transferase (AST) and alanine transaminase (ALT). Also, those patients showed significant improvement in AST, AST/platelets ratio index (APRI) and fibrosis-4 index (Fib-4) after achieving SVR; 91% showed AST improvement (p=0.01) and APRI improvement (p=0.01) and 81% showed Fib-4 improvement (p=0.04). Females, diabetics, patients with S3 steatosis and patients older than 50 years showed less LSM improvements than their counterparts. Baseline LSM &ge;9 kPa, bilirubin &ge;1 mg/dl, ALT &ge;36 U/L and AST &ge;31 U/L were significant predictors for LSM improvement.Conclusion: Successful HCV genotype-4 eradication results in significant LSM improvement; the best improvement occurs in F4 patients. But as the majority of cirrhotics are still at risk for liver decompensation and hepatocellular carcinoma development despite achieving SVR-24, early detection and treatment are highly recommended. Keywords: hepatitis C virus, direct acting antivirals, liver stiffness measurements, FibroScan, transient elastograph