275 research outputs found

    The Next 1616 Higher Spin Currents and Three-Point Functions in the Large N=4{\cal N}=4 Holography

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    By using the known operator product expansions (OPEs) between the lowest 1616 higher spin currents of spins (1,32,32,32,32,2,2,2,2,2,2,52,52,52,52,3)(1, \frac{3}{2}, \frac{3}{2}, \frac{3}{2}, \frac{3}{2}, 2,2,2,2,2,2, \frac{5}{2}, \frac{5}{2}, \frac{5}{2}, \frac{5}{2}, 3) in an extension of the large N=4{\cal N}=4 linear superconformal algebra, one determines the OPEs between the lowest 1616 higher spin currents in an extension of the large N=4{\cal N}=4 nonlinear superconformal algebra for generic NN and kk. The Wolf space coset contains the group G=SU(N+2)G =SU(N+2) and the affine Kac-Moody spin 11 current has the level kk. The next 1616 higher spin currents of spins (2,52,52,52,52,3,3,3,3,3,3,72,72,72,72,4)(2,\frac{5}{2}, \frac{5}{2}, \frac{5}{2}, \frac{5}{2}, 3,3,3,3,3,3, \frac{7}{2}, \frac{7}{2}, \frac{7}{2}, \frac{7}{2},4) arise in the above OPEs. The most general lowest higher spin 22 current in this multiplet can be determined in terms of affine Kac-Moody spin 12,1\frac{1}{2}, 1 currents. By careful analysis of the zero mode (higher spin) eigenvalue equations, the three-point functions of bosonic higher spin 2,3,42, 3, 4 currents with two scalars are obtained for finite NN and kk. Furthermore, we also analyze the three-point functions of bosonic higher spin 2,3,42, 3, 4 currents in the extension of the large N=4{\cal N}=4 linear superconformal algebra. It turns out that the three-point functions of higher spin 2,32,3 currents in the two cases are equal to each other at finite NN and kk. Under the large (N,k)(N,k) 't Hooft limit, the two descriptions for the three-point functions of higher spin 44 current coincide with each other. The higher spin extension of SO(4)SO(4) Knizhnik Bershadsky algebra is described.Comment: 94 pages; The 43 and 44 pages added, the mathematica notebook files included and to appear epj

    Leisure sedentary time is differentially associated with hypertension, diabetes mellitus, and hyperlipidemia depending on occupation

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    Abstract Background Sedentary behavior is considered an independent cause of cardio-metabolic diseases, regardless of physical activity level and obesity. Few studies have reported the association between leisure sedentary time and cardio-vascular diseases in terms of occupation. Methods We performed a cross-sectional study using data from the Korean Community Health Survey (KCHS) for 240,086 participants assessed in 2011 and 2013. Occupation was categorized into four groups: farmer or fisherman, laborer, and soldier (Group I); service worker, salesperson, technician, mechanic, production worker, and engineer (Group II); manager, expert, specialist, and clerk (Group III); and unemployed (Group IV). Leisure sedentary time was divided into five groups: 0 h, 1 h, 2 h, 3 h, and 4+ h. The association between leisure sedentary time on weekdays and hypertension/diabetes mellitus/hyperlipidemia for different occupations was analyzed using simple and multiple logistic regression analyses with complex sampling. Results In Groups I, II and III, no length of sedentary time was associated with hypertension, and only 3 h or 4+ h of sedentary time was associated with diabetes mellitus and hyperlipidemia. Group IV showed a significant association with hypertension and diabetes mellitus for the 2 h, 3 h, and 4+ h sedentary times. Conclusions The unemployed are more susceptible than other occupation groups to cardio-metabolic diseases when leisure time is sedentary

    Indications for open hepatectomy in the era of laparoscopic liver resection: a high volume single institutional study

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    Background/Aim Since the introduction of laparoscopy for liver resection in the 1990s, the performance of laparoscopic liver resection (LLR) has been steadily increasing. However, there is currently no data on the extent to which laparoscopy is used for liver resection. Herein, we investigated the extent to which laparoscopy is performed in liver resection and sought to determine whether surgeons prefer laparoscopy or laparotomy in the posterosuperior (PS) segment. Methods For this retrospective observational study, we enrolled patients who had undergone liver resection at the Samsung Medical Center between January 2020 and December 2021. The proportion of LLR in liver resection was calculated, and the incidence and causes of open conversion were investigated. Results A total of 1,095 patients were included in this study. LLR accounted for 79% of the total liver resections. The percentage of previous hepatectomy (16.2% vs. 5.9%, P<0.001) and maximum tumor size (median 4.8 vs. 2.8, P<0.001) were higher in the open liver resection (OLR) group. Subgroup analysis revealed that tumor size (median 6.3 vs. 2.9, P<0.001) and surgical extent (P<0.001) in the OLR group were larger than those in the LLR group. The most common cause of open conversion (OC) was adhesion (57%), and all OC patients had tumors in the PS. Conclusions We investigated the recent preference of practical surgeons in liver resection, and found that surgeons preferred OLR to LLR when treating a large tumor located in the PS

    Stent insertion and balloon angioplasty for portal vein stenosis after liver transplantation: long-term follow-up results

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    PURPOSEIt is not easy to determine whether balloon angioplasty or stenting should be performed in patients with portal vein stenosis after liver transplantation. We aimed to propose appropriate indication by evaluating long-term outcomes of balloon angioplasty and stent insertion in adult liver transplant patients.METHODSWe retrospectively reviewed 31 patients with portal vein stenosis among 1369 patients who underwent adult liver transplantation from January 2001 to December 2015. When stenosis was confirmed by venography, angioplasty was performed first. When there was no flow improvement or pressure gradient was not decreased after angioplasty, stent insertion was performed. We also performed primary stent insertion without angioplasty for diffuse stenosis, kinking, external compression, and near occlusion of portal vein in venography. We assessed patency in patients who underwent percutaneous transluminal angioplasty and stent insertion through regular outpatient follow-up and evaluated technical and clinical success and long-term results.RESULTSTechnical success was 85% and 100% in balloon angioplasty and stent insertion, respectively. Clinical success was achieved in 78% of balloon angioplasties and in 100% of stent insertions. At 1, 5, and 10 years after balloon angioplasty, patency rates were 87%, 82%, and 68% respectively, and the rates of stent patency were all 100%. Portal vein size measured during the operation of patients with and without recurrence were 19±4.2 mm and 19±3.0 mm (P = 0.956), respectively. The balloon size of patients with and without recurrence were 11±1.95 mm and 14±1.66 mm, respectively (P = 0.013), when balloon angioplasty was performed after stenosis diagnosis.CONCLUSIONStent insertion can be considered when fibrotic changes are expected due to repeated inflammation and when the balloon size to be used is small. Balloon angioplasty seems less risky for anastomotic ruptures in portal vein stenosis in the early post liver transplantation period

    Cystamine induces AIF-mediated apoptosis through glutathione depletion

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    AbstractCystamine and its reduced form cysteamine showed protective effects in various models of neurodegenerative disease, including Huntington's disease and Parkinson's disease. Other lines of evidence demonstrated the cytotoxic effect of cysteamine on duodenal mucosa leading to ulcer development. However, the mechanism for cystamine cytotoxicity remains poorly understood. Here, we report a new pathway in which cystamine induces apoptosis by targeting apoptosis-inducing factor (AIF). By screening of various cell lines, we observed that cystamine and cysteamine induce cell death in a cell type-specific manner. Comparison between cystamine-sensitive and cystamine-resistant cell lines revealed that cystamine cytotoxicity is not associated with unfolded protein response, reactive oxygen species generation and transglutaminase or caspase activity; rather, it is associated with the ability of cystamine to trigger AIF nuclear translocation. In cystamine-sensitive cells, cystamine suppresses the levels of intracellular glutathione by inhibiting γ-glutamylcysteine synthetase expression that triggers AIF translocation. Conversely, glutathione supplementation completely prevents cystamine-induced AIF translocation and apoptosis. In rats, cysteamine administration induces glutathione depletion and AIF translocation leading to apoptosis of duodenal epithelium. These results indicate that AIF translocation through glutathione depletion is the molecular mechanism of cystamine toxicity, and provide important implications for cystamine in the neurodegenerative disease therapeutics as well as in the regulation of AIF-mediated cell death

    Cardiac tamponade caused by tuberculosis pericarditis in renal transplant recipients

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    A 50-year-old male, renal transplant recipient, was admitted with fever and chest discomfort. At admission, chest radiologic finding was negative and echocardiography showed minimal pericardial effusion. After 2 days of admission, chest pain worsened and blood pressure fell to 60/40 mmHg. Emergency echocardiography showed a large amount of pericardial effusion compressing the entire heart. Pericardiocentesis was performed immediately. Mycobacterium tuberculosis was isolated from pericardial fluid. Tuberculosis pericarditis should be considered as the cause of cardiac tamponade in renal transplant recipients, even with the absence of pericardial effusion in the initial study or suggestive history

    Monoclonal Antibodies to Human Transglutaminase 4

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    Transglutaminase 4 (TG4) is a member of the enzyme family that catalyzes the calcium-dependent post-translational modification of proteins via cross-linking, polyamination, or deamidation. TG4 exhibits prostate-specific expression pattern and plays a crucial role in the formation of the copulatory plug in rodents. However, the physiological function(s) of human TG4 remains speculative. Human TG4 has been postulated to participate in the maturation process of sperm by modifying its cell surface, which results in suppression of sperm antigenicity in the female genital tract. To better understand the pathophysiological role of TG4 in prostate tissue, we generated monoclonal antibodies (MAb) against human TG4 in mice by repeated injections with the recombinant human TG4. Western blot analysis demonstrated that the selected MAbs react specifically with TG4, but not with other isoenzymes of the TG family. Immunocytochemical and immunohistochemical analyses showed that specific staining is observed with the cells overexpressing TG4 and with the paraffin-embedded prostate tissue specimens obtained from the benign prostate hyperplasia and prostate cancer patients, respectively. Our results indicate that these MAbs are suitable for detecting TG4 in the cultured cells or prostate tissues for investigating the biological functions of human TG4.Shin DM, 2004, J BIOL CHEM, V279, P15032, DOI 10.1074/jbc.M308734200Jeon JH, 2003, EMBO J, V22, P5273Lorand L, 2003, NAT REV MOL CELL BIO, V4, P140, DOI 10.1038/nrm1014Jeon JH, 2002, BIOCHEM BIOPH RES CO, V294, P818An G, 1999, UROLOGY, V54, P1105Dubbink HJ, 1999, GENE, V240, P261Dubbink HJ, 1999, LAB INVEST, V79, P141Choi K, 1998, EXP MOL MED, V30, P41Esposito C, 1996, J BIOL CHEM, V271, P27416Dubbink HJ, 1996, BIOCHEM J, V315, P901SEITZ J, 1991, BIOCHIM BIOPHYS ACTA, V1078, P139PAONESSA G, 1984, SCIENCE, V226, P852MUKHERJEE DC, 1983, SCIENCE, V219, P989WILLIAMSASHMAN HG, 1977, BIOCHEM BIOPH RES CO, V79, P1192WILLIAMS.HG, 1972, P NATL ACAD SCI USA, V69, P2322
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