118 research outputs found

    Orbital-Dependent Polaron Formation in the Relativistic Mott Insulator Sr\u3csub\u3e2\u3c/sub\u3eIrO\u3csub\u3e4\u3c/sub\u3e

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    We use optical spectroscopy to investigate the electron-phonon interaction in Sr2IrO4, a well-known 5d transition metal oxide with spin-orbit entangled states. The temperature evolution in the optical spectra is well described by the Fröhlich polaron model, indicating a large electron-phonon interaction. We further find that electrons in different orbitals selectively couple with different phonon modes. While Jeff = 3/2 holes do not seem to couple with any phonons, Jeff = 1/2 and 3z2−r2 electrons mainly couple with in-plane and out-of-plane Ir-O bending modes, respectively. The symmetries of the orbitals and phonons are consistent with our observations

    A case of portal hypertension by presumed as plexiform neurofibroma at the hepatic hilum

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    Neurofibromas can occur anywhere in the body, but they usually involve the head, neck, pelvis, and extremities. Abdominal visceral involvement is rare, and intrahepatic involvement is even less common. We describe a patient who suffered from plexiform neurofibromatosis with liver involvement. A 49-year-old man, who had previously been diagnosed with neurofibromatosis, underwent esophagogastroduodenoscopy and abdominal ultrasonography for screening purposes. Esophagogastroduodenoscopy showed grade 2 esophageal varices and abdominal ultrasonography showed conglomerated nodules with echogenic appearances in the perihepatic space. Magnetic resonance imaging showed presumed plexiform neurofibroma involving the lesser sac and hepatic hilum and encasing the common hepatic artery celiac trunk and superior mesenteric artery left portal triad. We report an unusual case of portal hypertension attributed to the compressive narrowing of the portal vein by presumed as plexiform neurofibroma at the lesser sac and hepatic hilum

    Emerging Need for Vaccination against Hepatitis A Virus in Patients with Chronic Liver Disease in Korea

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    Vaccination against hepatitis A virus (HAV) is recommended for patients with chronic liver disease (CLD), but this has been deemed unnecessary in Korea since the immunity against HAV was almost universal in adults. However, this practice has never been reevaluated with respect to the changing incidence of adult acute hepatitis A. We retrospectively reviewed the medical records of 278 patients with acute hepatitis A diagnosed from January 1995 to November 2005 and prospectively tested 419 consecutive CLD patients from July to December 2005 for the presence of IgG anti-HAV. The number of patients with acute hepatitis A has markedly increased recently, and the proportion of adult patients older than 30 yr has been growing from 15.2% during 1995-1999, to 28.4% during 2000-2005 (p=0.019). Among 419 CLD patients, the seroprevalences of IgG anti-HAV were 23.1% for those between 26 and 30 yr, 64% between 31 and 35 yr, and 85.0% between 36 and 40 yr. These data demonstrate that immunity against HAV is no more universal in adult and substantial proportion of adult CLD patients are now at risk of HAV infection in Korea. Therefore, further study on seeking proper strategy of active immunization against HAV is warranted in these populations

    Mutations in DDX58, which Encodes RIG-I, Cause Atypical Singleton-Merten Syndrome

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    Singleton-Merten syndrome (SMS) is an autosomal-dominant multi-system disorder characterized by dental dysplasia, aortic calcification, skeletal abnormalities, glaucoma, psoriasis, and other conditions. Despite an apparent autosomal-dominant pattern of inheritance, the genetic background of SMS and information about its phenotypic heterogeneity remain unknown. Recently, we found a family affected by glaucoma, aortic calcification, and skeletal abnormalities. Unlike subjects with classic SMS, affected individuals showed normal dentition, suggesting atypical SMS. To identify genetic causes of the disease, we performed exome sequencing in this family and identified a variant (c.1118A>C [p.Glu373Ala]) of DDX58, whose protein product is also known as RIG-I. Further analysis of DDX58 in 100 individuals with congenital glaucoma identified another variant (c.803G>T [p.Cys268Phe]) in a family who harbored neither dental anomalies nor aortic calcification but who suffered from glaucoma and skeletal abnormalities. Cys268 and Glu373 residues of DDX58 belong to ATP-binding motifs I and II, respectively, and these residues are predicted to be located closer to the ADP and RNA molecules than other nonpathogenic missense variants by protein structure analysis. Functional assays revealed that DDX58 alterations confer constitutive activation and thus lead to increased interferon (IFN) activity and IFN-stimulated gene expression. In addition, when we transduced primary human trabecular meshwork cells with c.803G>T (p.Cys268Phe) and c.1118A>C (p.Glu373Ala) mutants, cytopathic effects and a significant decrease in cell number were observed. Taken together, our results demonstrate that DDX58 mutations cause atypical SMS manifesting with variable expression of glaucoma, aortic calcification, and skeletal abnormalities without dental anomalies

    Mutations in DDX58, which Encodes RIG-I, Cause Atypical Singleton-Merten Syndrome

    Get PDF
    Singleton-Merten syndrome (SMS) is an autosomal-dominant multi-system disorder characterized by dental dysplasia, aortic calcification, skeletal abnormalities, glaucoma, psoriasis, and other conditions. Despite an apparent autosomal-dominant pattern of inheritance, the genetic background of SMS and information about its phenotypic heterogeneity remain unknown. Recently, we found a family affected by glaucoma, aortic calcification, and skeletal abnormalities. Unlike subjects with classic SMS, affected individuals showed normal dentition, suggesting atypical SMS. To identify genetic causes of the disease, we performed exome sequencing in this family and identified a variant (c.1118A>C [p.GLu373Ala]) of DDX58, whose protein product is also known as RIG-I. Further analysis of DDX58 in 100 individuals with congenital glaucoma identified another variant (c.803G>T [p.Cys268Phe]) in a family who harbored neither dental anomalies nor aortic calcification but who suffered from glaucoma and skeletal abnormalities. Cys268 and Glu373 residues of DDX58 belong to ATP-binding motifs I and II, respectively, and these residues are predicted to be located closer to the ADP and RNA molecules than other nonpathogenic missense variants by protein structure analysis. Functional assays revealed that DDX58 alterations confer constitutive activation and thus lead to increased interferon (IFN) activity and IFN-stimulated gene expression. In addition, when we transduced primary human trabecular meshwork cells with c.803G>T (p.Cys268Phe) and c.1118A>C (p.Glu373A1a) mutants, cytopathic effects and a significant decrease in cell number were observed. Taken together, our results demonstrate that DDX58 mutations cause atypical SMS manifesting with variable expression of glaucoma, aortic calcification, and skeletal abnormalities without dental anomalies.X116452Ysciescopu

    Cardiovascular Parameters Correlated with Metabolic Syndrome in a Rural Community Cohort of Korea: The ARIRANG Study

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    Although metabolic syndrome (MetS) is associated with increased cardiovascular mortality and the development of atherosclerosis, consensus is still lacking on the status of cardiovascular function and geometry in MetS patients. We investigated the relation between MetS and left ventricle (LV) geometry and function, carotid intima-media thickness (IMT) and arterial stiffness in a community-based cohort of 702 adult subjects. Subjects were categorized into three groups according to the number of MetS components present, as defined by the Adult Treatment Panel III guidelines: 1) Absent (0 criteria), 2) Pre-MetS (1-2 criteria) or 3) MetS (≥3 criteria). In female subjects, LV mass, LV mass/height2.7, deceleration time, and aortic pulse wave velocity increased, and E/A ration decreased in a stepwise manner across the three groups. These changes were not observed in male subjects. The mean carotid IMT was higher in the MetS group than in the other two groups. The degree of MetS clustering is found to be strongly correlated with geometric eccentricity of LV hypertrophy, diastolic dysfunction and arterial changes irrespective of age and blood pressure status, particularly in females. Waist circumference is found to have the most powerful effect on cardiovascular parameters

    A Multiinstitutional Consensus Study on the Pathologic Diagnosis of Endometrial Hyperplasia and Carcinoma

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    BACKGROUND: The purpose of this study was to examine the reproducibility of both the diagnosis of endometrial hyperplasia (EH) or adenocarcinoma, and the histologic grading (HG) of endometrioid adenocarcinoma (EC). METHODS: Ninety-three cases of EH or adenocarcinomas were reviewed independently by 21 pathologists of the Gynecologic Pathology Study Group. A consensus diagnosis was defined as agreement among more than two thirds of the 21 pathologists. RESULTS: There was no agreement on the diagnosis in 13 cases (14.0%). According to the consensus review, six of the 11 EH cases (54.5%) were diagnosed as EH, 48 of the 57 EC cases (84.2%) were EC, and 5 of the 6 serous carcinomas (SC) (83.3%) were SC. There was no consensus for the 6 atypical EH (AEH) cases. On the HG of EC, there was no agreement in 2 cases (3.5%). According to the consensus review, 30 of the 33 G1 cases (90.9%) were G1, 11 of the 18 G2 cases (61.1%) were G2, and 4 of the 4 G3 cases (100.0%) were G3. CONCLUSIONS: The consensus study showed high agreement for both EC and SC, but there was no consensus for AEH. The reproducibility for the HG of G2 was poor. We suggest that simplification of the classification of EH and a two-tiered grading system for EC will be necessary.This study was partly supported by research fund of Chungnam National University in 2007
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