18 research outputs found

    Privacy-preserving PKI design based on group signature

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    Nowadays, Internet becomes a part of our life. We can make use of numerous services with personal computer, Lap-top, tablet, smart phone or smart TV. These devices with network make us enjoy ubiquitous computing life. Sometimes, on-line services request us authentication or identification for access control and authorization, and PKI technology is widely used because of its security. However the possibility of privacy invasion will increase, if Weā€™re identified with same certificate in many services and these identification data are accumulated. For privacy-preserving authentication or anonymous authentication, there have been many researches such as Group signatures, anonymous credentials, etc. Among these researches, group signatures are very practical Because they provide unlinkability and traceability as well as anonymity. In this paper, we propose a privacy-preserving PKI based on group signature, with which usersā€™ privacy can be Kept in services. Because of traceability, their identities can be traced if they abuse anonymity such as cybercrime. Moreover, we will also discuss open issues for further studies

    Effect of chitinase- 3- like protein 1 on glucose metabolism: In vitro skeletal muscle and human genetic association study

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    We investigated the effect of chitinase- 3- like protein 1 (CHI3L1) on glucose metabolism and its underlying mechanisms in skeletal muscle cells, and evaluated whether the observed effects are relevant in humans. CHI3L1 was associated with increased glucose uptake in skeletal muscles in an AMP- activated protein kinase (AMPK)- dependent manner, and with increased intracellular calcium levels via PAR2. The improvement in glucose metabolism observed in an intraperitoneal glucose tolerance test on male C57BL/6J mice supported this association. Inhibition of the CaMKK was associated with suppression of CHI3L1- mediated glucose uptake. Additionally, CHI3L1 was found to influence glucose uptake through the PI3K/AKT pathway. Results suggested that CHI3L1 stimulated the phosphorylation of AS160 and p38 MAPK downstream of AMPK and AKT, and the resultant GLUT4 translocation. In primary myoblast cells, stimulation of AMPK and AKT was observed in response to CHI3L1, underscoring the biological relevance of CHI3L1. CHI3L1 levels were elevated in cells under conditions that mimic exercise in vitro and in exercised mice in vivo, indicating that CHI3L1 is secreted during muscle contraction. Finally, similar associations between CHI3L1 and metabolic parameters were observed in humans alongside genotype associations between CHI3L1 and diabetes at the population level. CHI3L1 may be a potential therapeutic target for the treatment of diabetes.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/162777/2/fsb220907.pdfhttp://deepblue.lib.umich.edu/bitstream/2027.42/162777/1/fsb220907_am.pd

    Omega-3 fatty acids supplementation on major cardiovascular outcomes: an umbrella review of meta-analyses of observational studies and randomized controlled trials

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    OBJECTIVE: Omega-3 fatty acids are commonly used as a lipid-lowering agent or dietary supplement for the purpose of prevention of cardiovascular diseases. However, even large-scale clinical trials have not shown significant results demonstrating clear clinical benefits in cardiovascular diseases. Thus, this umbrella review aims to summarize and evaluate the evidence of clinical effects of omega-3 fatty acids supplementation on cardiovascular outcomes through comprehensive analyses of previous randomized controlled trials (RCTs) or observational cohort studies. MATERIALS AND METHODS: We conducted relevant publication search in PubMed, Embase, and Cochrane Database of Systematic Reviews. We retrieved and analyzed 3,298 articles published until August 28th, 2019. RESULTS: We identified 29 relevant articles and analyzed 83 meta-analyses of RCTs or cohort studies therefrom. As a result, we identified 12 cardiovascular outcomes that are related to omega-3 fatty acids supplementation. Among them, total mortality from major cardiovascular causes (RR 0.92, 95% CI 0.86 to 0.98) had significant inverse associations, and moreover, statistical significances were maintained even in subgroup analysis of large-scale RCTs including more than 1,000 patients (RR 0.94, 95% CI 0.88 to 0.99). CONCLUSIONS: Our umbrella review study shows that omega-3 fatty acids supplementation have a clinical benefit in reducing mortality from cardiovascular causes. However, many studies still have shown conflicting results, and therefore, further studies will be needed to verify the clinical benefit of omega-3 supplementation

    Clinical features and outcomes of gastric variceal bleeding: retrospective Korean multicenter data

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    Background/AimsWhile gastric variceal bleeding (GVB) is not as prevalent as esophageal variceal bleeding, it is reportedly more serious, with high failure rates of the initial hemostasis (>30%), and has a worse prognosis than esophageal variceal bleeding. However, there is limited information regarding hemostasis and the prognosis for GVB. The aim of this study was to determine retrospectively the clinical outcomes of GVB in a multicenter study in Korea.MethodsThe data of 1,308 episodes of GVB (males:females=1062:246, age=55.0Ā±11.0 years, meanĀ±SD) were collected from 24 referral hospital centers in South Korea between March 2003 and December 2008. The rates of initial hemostasis failure, rebleeding, and mortality within 5 days and 6 weeks of the index bleed were evaluated.ResultsThe initial hemostasis failed in 6.1% of the patients, and this was associated with the Child-Pugh score [odds ratio (OR)=1.619; P<0.001] and the treatment modality: endoscopic variceal ligation, endoscopic variceal obturation, and balloon-occluded retrograde transvenous obliteration vs. endoscopic sclerotherapy, transjugular intrahepatic portosystemic shunt, and balloon tamponade (OR=0.221, P<0.001). Rebleeding developed in 11.5% of the patients, and was significantly associated with Child-Pugh score (OR=1.159, P<0.001) and treatment modality (OR=0.619, P=0.026). The GVB-associated mortality was 10.3%; mortality in these cases was associated with Child-Pugh score (OR=1.795, P<0.001) and the treatment modality for the initial hemostasis (OR=0.467, P=0.001).ConclusionsThe clinical outcome for GVB was better for the present cohort than in previous reports. Initial hemostasis failure, rebleeding, and mortality due to GVB were universally associated with the severity of liver cirrhosis

    Histone Deacetylase Inhibitors Sensitize Human Non-small Cell Lung Cancer Cells to Ionizing Radiation Through Acetyl p53-Mediated c-myc Down-Regulation

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    IntroductionHistone deacetylase inhibitors (HDACIs) induce growth arrest and apoptosis in cancer cells. In addition to their intrinsic anticancer properties, HDACIs modulate cellular responses to ionizing radiation (IR). We examined the molecular mechanism(s) associated with the radiosensitizing effects of HDACIs in human lung cancer cells.MethodsLung cancer cells were pretreated with the appropriate concentrations of suberoylanilide hydroxamic acid or trichostatin A. After 2 hours, cells were irradiated with various doses of Ī³-IR, and then we performed 3-(4,5-Dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide assay, fluorescence-activated cell sorting analysis, clonogenic assay, and Western blotting to detect cell viability or apoptosis and changes of specific proteins expression levels.ResultsIn this study, we showed that HDACIs (including suberoylanilide hydroxamic acid and trichostatin A) and IR synergistically trigger cell death in human non-small cell lung cancer cells. Cell viability and clonogenic survival were markedly decreased in cultures cotreated with HDACIs and IR. Interestingly, p53 acetylation at lysine 382 was significantly increased, and c-myc expression simultaneously down-regulated in cotreated cells. Radiosensitization by HDACIs was inhibited on transfection with small interfering RNA against p53 and c-myc overexpression, supporting the involvement of p53 and c-myc in this process. Furthermore, c-myc down-regulation and apoptotic cell death coinduced by IR and HDACI were suppressed in cells transfected with mutant K382R p53 and C135Y p53 displaying loss of acetylation at lysine 382 and DNA-binding activity, respectively.ConclusionsOur results collectively demonstrate that the degree of radiosensitization by HDACIs is influenced by acetyl p53-mediated c-myc down-regulation
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