Observation of a Highly Spin Polarized Topological Surface State in GeBi2_{2}Te4_{4}

Spin polarization of a topological surface state for GeBi$_2$Te$_4$, the newly discovered three-dimensional topological insulator, has been studied by means of the state of the art spin- and angle-resolved photoemission spectroscopy. It has been revealed that the disorder in the crystal has a minor effect on the surface state spin polarization and it exceeds 75% near the Dirac point in the bulk energy gap region ($\sim$180 meV). This new finding for GeBi$_{2}$Te$_{4}$ promises not only to realize a highly spin polarized surface isolated transport but to add new functionality to its thermoelectric and thermomagnetic properties.Comment: 5 pages, 4 figure

Endoscopic Manifestations and Clinical Characteristics of Localized Gastric Light-Chain Amyloidosis

To determine the endoscopic and clinical features of localized gastric amyloid light-chain (AL) amyloidosis, we retrospectively examined the characteristics of nine patients (eight men and one woman) encountered by the hospitals in our network. Lesions were predominantly flat and depressed with surface vascular dilatation (n=5); others were characterized by subepithelial lesions (n=2), mucosal color change (n=1), and a mass-like morphology with swollen mucosal folds (n=1). Colonoscopy (n=7), video capsule enteroscopy (n=2), serum (n=5) and urine immunoelectrophoresis (n=4), and bone marrow examination (n=3) were performed to exclude involvement of organs other than the stomach. As treatment for gastric lesions of AL amyloidosis, one patient each underwent endoscopic submucosal dissection (n=1) and argon plasma coagulation (n=1), while the remaining seven patients underwent no specific treatment. During a mean follow-up of 4.2 years, one patient died 3.2 years after diagnosis, but the cause of death, which occurred in another hospital, was unknown. The remaining eight patients were alive at the last visit. In conclusion, although localized gastric AL amyloidosis can show various macroscopic features on esophagogastroduodenoscopy, flat, depressed lesions with vascular dilatation on the surface are predominant

A case of hepatocellular carcinoma with skin injury of the upper abdominal wall after transcatheter arterial chemoembolization: a case report

Introduction Transcatheter arterial chemoembolization has been widely used to treat advanced hepatocellular carcinoma that cannot be treated by local ablation therapies or surgical resection. The effectiveness of transcatheter arterial chemoembolization in prolonging survival has been well established, and approximately one third of newly discovered hepatocellular carcinoma patients were repeatedly treated by transcatheter arterial chemoembolization in Japan. Various kinds of complications have been reported, and many of which are general complications such as hepatic coma, jaundice, fever-up, ascites, and bile duct injury. The hepatic falciform artery is found frequently during postmortem anatomic dissection and the incidence of hepatic falciform artery is reported to be over 60%. Hepatic falciform artery is known to be the responsible artery for supraumbilical skin rash development after arterial chemo infusion therapy; however, skin complications after transcatheter arterial chemoembolization are rare. Case presentation A 70-year-old female with chronic hepatitis C infection was diagnosed as having hepatocellular carcinoma (S4, 20 mm in diameter). Transcatheter arterial chemoembolization was performed via the left hepatic artery, which was a feeding artery of the hepatocellular carcinoma. Two days after that, supraumbilical skin rash with local tenderness and redness appeared. Retrospective analysis revealed that occlusion of the hepatic falciform artery branching from the left hepatic artery with micromaterials caused the skin lesion. Conclusion We should keep in mind that anticancer drugs or embolic materials can flow into the HFA and may cause abdominal wall injury after transcatheter arterial chemoembolization

Bone fragility via degradation of bone quality featured by collagen/apatite micro-arrangement in human rheumatic arthritis

Although increased bone fragility is a well-recognized consequence in patients with rheumatoid arthritis (RA), the essential cause of degenerate bone strength remains unknown. This study aimed to determine factors contributing to bone dysfunction in RA by focusing on the bone matrix micro-arrangement, based on the preferential orientation of collagen and the related apatite c-axis as a bone quality index. The classical understanding of RA is limited to its severe pathological conditions associated with inflammation-induced bone loss. This study examined periarticular proximal tibiae from RA patients as compared with osteoarthritis (OA) patients as controls. Bone tissue material strength was disrupted in the RA group compared with the control. Collagen/apatite micro-arrangement and vBMD were significantly lower in the RA group, and the rate of decrease in apatite c-axis orientation (−45%) was larger than that in vBMD (−22%). Multiple regression analysis showed that the degree of apatite c-axis orientation (β = 0.52, p = 1.9 × 10−2) significantly contributed to RA-induced bone material impairment as well as vBMD (β = 0.46, p = 3.8 × 10−2). To the best of our knowledge, this is the first report to demonstrate that RA reduces bone material strength by deteriorating the micro-arrangement of collagen/apatite bone matrix, leading to decreased fracture resistance. Our findings represent the significance of bone quality-based analysis for precise evaluation and subsequent therapy of the integrity and soundness of the bone in patients with RA.Ozasa R., Matsugaki A., Ishimoto T., et al. Bone fragility via degradation of bone quality featured by collagen/apatite micro-arrangement in human rheumatic arthritis. Bone, 155, 116261. https://doi.org/10.1016/j.bone.2021.116261

Diagnostic Role of 18F-Fluorodeoxyglucose Positron Emission Tomography in Gastric Mesenchymal Tumors

There have been no comparative studies investigating the results of 18F-fluorodeoxyglucose (FDG)-positron emission tomography (PET) in patients with gastric mesenchymal tumors, including leiomyomas, leiomyosarcomas, schwannomas, and gastrointestinal stromal tumors (GISTs). We retrospectively reviewed the data of 142 patients with pathologically diagnosed gastric mesenchymal tumors treated at 11 institutions. We analyzed the correlation between the maximum standardized uptake value (SUVmax) evaluated using fluorodeoxyglucose-positron emission tomography (FDG-PET) and the tumor size. The correlation between the SUVmax and mitotic index was also investigated in GISTs. The SUVmax (mean +/- standard deviation) was 0.5 +/- 0.6 in very low-risk GISTs (n = 42), 2.1 +/- 0.7 in low-risk GISTs (n = 26), 4.9 +/- 0.8 in intermediate-risk GISTs (n = 22), 12.3 +/- 0.8 in high-risk GISTs (n = 20), 1.0 +/- 1.0 in leiomyomas (n = 15), 6.9 +/- 1.2 in schwannomas (n = 10), and 3.5 in a leiomyosarcoma (n = 1). The SUVmax of GISTs with an undetermined risk classification was 4.2 +/- 1.3 (n = 8). Linear associations were observed between the SUVmax and tumor size in GISTs, leiomyomas, and schwannomas. The SUVmax of GISTs with a high mitotic index was significantly higher than that of GISTs with a low mitotic index (9.6 +/- 7.6 vs. 2.4 +/- 4.2). In conclusion, we observed positive correlations between the SUVmax and tumor size in GISTs, leiomyomas, and schwannomas. The SUVmax also positively correlated with the mitotic index and risk grade in GISTs. Schwannomas showed a higher FDG uptake than GISTs and leiomyomas

Topological surface states of ternary chalcogenides probed by ARPES

Trabajo presentado a la "16th International Conference on Solid Films and Surfaces" celebrada en Genova (Italia) del 1 al 6 de julio de 2012.Three-dimensional topological insulators (3D TIs) recently emerge as a new state of quantum matter, which can be topologically classified with Z2 topological invariants. It possesses a massless Dirac Fermion in a bulk energy gap whose spin orientations are locked with electron momentum, resulting in a helical spin texture. A number of 3D TIs have been intensively studied, among which Bi2Se3 has been regarded as one of the most promising candidates for potential applications in ultra-low power consumption quantum devices that can work stably at room temperature due to a sufficiently large bulk energy gap. Therefore, a significant effort has been made towards spintronic applications, but the surface contribution to conduction was hardly observed. This stimulates us to search for new 3D TIs possessing more ideal Dirac Fermions sufficiently isolated from the bulk continuum as actually predicted in several ternary compounds. Here we have studied the surface Dirac cones of several ternary chalcogenides including TlBiSe2 and PbBi2Te4 by high-resolution angle resolved photoemission spectroscopy using synchrotron radiation at Hiroshima Synchrotron Radiation Center (HiSOR). The single topological surface state is confirmed to be present at the surface Brillouin zone (SBZ) center for TlBiSe2. The Dirac cone is practically ideal especially near the Dirac point and its velocity is larger than for Bi2Se3. There are no bulk continuum states that energetically overlap with the DP, which means that the scattering channel from the topological surface state to the bulk continuum is suppressed. We have also clarified that PbBi2Te4 is the 3D TI, accompanying a single Dirac cone at the SBZ center. The size of the Fermi surface contours are significantly large in the bulk energy gap region. Besides, this material is found to have a Z2 topological invariant 1; (111). These novel findings pave an effective way for controlling the group velocity with sufficiently large spin current density by tuning the chemical potential in the topological quantum transport regionPeer Reviewe

Analysis of HCV genotypes from blood donors shows three new HCV type 6 subgroups exist in Myanmar.

The prevalence of hepatitis C virus (HCV) genotypes in Myanmar in comparison with the rest of Southeast Asia is not well known. Serum samples were obtained from 201 HCV antibody-positive volunteer blood donors in and around the Myanmar city of Yangon. Of these, the antibody titers of 101 samples were checked by serial dilution using HCV antibody PA test II and Terasaki microplate as a low-cost method. To compare antibody titers by this method and RNA identification, we also checked HCV-RNA using the Amplicor 2.0 test. Most high-titer groups were positive for HCV-RNA. Of the 201 samples, 110 were successfully polymerase chain reaction (PCR) amplified. Among them, 35 (31.8%) were of genotype 1, 52 (47.3%) were of genotype 3, and 23 (20.9%) were of type 6 variants, and phylogenetic analysis of these type 6 variants revealed that 3 new type 6 subgroups exist in Myanmar. We named the subgroups M6-1, M6-2, and M6-3. M6-1 and M6-2 were relatively close to types 8 and 9, respectively. M6-3, though only found in one sample, was a brand-new subgroup. These subtypes were not seen in Vietnam, where type 6 group variants are widely spread. These findings may be useful for analyzing how and when these subgroups were formed

Clinical Course of a Rare Epstein-Barr Virus-Associated Smooth Muscle Tumor and Its Genomic Analysis

Epstein-Barr virus (EBV) can rarely induce smooth muscle tumors (SMTs). A 20-year-old female patient underwent kidney transplantation for renal failure. Since then, she has been treated with immunosuppressants, including a calcineurin inhibitor, tacrolimus, and prednisolone, owing to the immunological rejection. Three years later, she developed large liver tumors (diameter >5 cm) and multiple small lung tumors that were identified as EBV-SMTs based on the results of liver biopsy/histopathology. No intervention was performed except for the addition of a mammalian target of the rapamycin inhibitor, everolimus, which inhibits both immune reaction and SMT growth. Finally, after 8 years, the transplanted kidney became nonfunctional, and immunosuppressant administration became unnecessary as urinary dialysis was started. Under these circumstances, SMT growth was observed despite the absence of immunosuppressant administration. Three months after the cessation of the immunosuppressants, EBV-SMTs in the liver and lungs shrank slightly. To the best of our knowledge, this is the first report on the genomic profile of this rare tumor. The clinical course of our patient indicates that EBV can induce SMTs, and immunological suppression of EBV may inhibit the activity of these tumors