431 research outputs found
Investigating the Single Production of Vector-Like Quarks Decaying into Top Quark and W Boson through Hadronic Channels at the HL-LHC
We investigate the single production of vector-like quarks at the High
Luminosity LHC (HL-LHC). With the assumed (enhanced) couplings to third
generation quarks of the standard model, vector-like quarks are produced
in association with a bottom () or top () quark, which correspond to
and production modes, including an additional soft forward jet
from the spectator quark (). This study focuses on high-mass vector-like
quarks decaying into a top quark and a boson, resulting in the final
state jets emerging from hadronically decaying top quark () and
boson (). The events with boson and quark have been
analysed using tagging techniques for large-radius jets. The scan ranges of the
mass ( GeV) for the relative width
of vector-like quarks have been investigated. From the results of the
analysis, the masses of vector like quarks B (X) up to 2550 (2450) GeV can be
excluded at CL depending on the type and branching scenarios at
integrated luminosity projection of ab at the HL-LHC.Comment: 18 pages, 5 Tables, 6 Figure
SppC based energy frontier lepton-proton colliders: luminosity and physics
In this study, main parameters of Super proton-proton Collider (SppC) based
lepton-proton colliders are estimated. For electron beam parameters, highest
energy International Linear Collider (ILC) and Plasma Wake Field
Accelerator-Linear Collider (PWFA-LC) options are taken into account. For muon
beams, 1.5 TeV and 3 TeV center of mass energy Muon Collider parameters are
used. In addition, ultimate p collider which assumes construction of
additional 50 TeV muon ring in the SppC tunnel is considered as well. It is
shown that can be achieved with
moderate upgrade of the SppC proton beam parameters. Physics search potential
of proposed lepton-proton colliders is illustrated by considering small Bjorken
x region as an example of SM physics and resonant production of color octet
leptons as an example of BSM physics.Comment: 11 pages, 3 figures, 8 table
Glutathione-S-transferase subtypes α and π as a tool to predict and monitor graft failure or regeneration in a pilot study of living donor liver transplantation
<p>Abstract</p> <p>Objective</p> <p>Glutathione-S-Transferase (GST) subtype α and π are differentially expressed in adult liver tissue. Objective of the study was if GST α and p may serve as predictive markers for liver surgery, especially transplantations.</p> <p>Methods</p> <p>13 patients receiving living donor liver transplantation (LDLT) and their corresponding donors were analyzed for standard serum parameters (ALT, AST, gGT, bilirubin) as well as GST-α and -π before LDLT and daily for 10 days after LDLT. Patients (R) and donors (D) were grouped according to graft loss (R1/D1) or positive outcome (R2/D2) and above named serum parameters were compared between the groups.</p> <p>Results</p> <p>R1 showed significantly increased GST-α and significantly lower GST-π levels than R2 patients or the donors. There was a positive correlation between GST-α and ALT, AST as well as bilirubin and a negative correlation to γGT. However, γGT correlated positively with GST-π. Graft failure was associated with combined low GST-π levels in donors and their recipients before living donor liver transplantation.</p> <p>Conclusion</p> <p>Our data suggest that high GST-α serum levels reflect ongoing liver damage while GST-P indicates the capacity and process of liver regeneration. Additionally, GST-π may be useful as marker for optimizing donor and recipient pairs in living donor liver transplantation.</p
A Rare Case of Propofol-Induced Acute Liver Failure and Literature Review
The incidence of drug-induced acute liver failure is increasing. A number of drugs can inhibit mitochondrial functions, alter β-oxidation and cause accumulation of free fatty acids within the hepatocytes. This may result in hepatic steatosis, cell death and liver injury. In our case, propofol, an anesthetic drug commonly used in adults and children, is suspected to have induced disturbance of the mitochondrial respiratory chain, which in consequence led to insufficient energy supply and finally liver failure. We report the case of a 35-year-old Caucasian woman with acute liver failure after anesthesia for stripping of varicose veins. Liver histology, imaging and laboratory data indicate drug-induced acute liver failure, presumably due to propofol. Hepatocyte death and microvesicular fatty degeneration of 90% of the liver parenchyma were observed before treatment with steroids. Six months later, a second biopsy was performed, which revealed only minimal steatosis and minimal periportal hepatitis. We suggest that propofol led to impaired fatty acid oxidation possibly due to a genetic susceptibility. This caused free fatty acid accumulation within hepatocytes, which presented as hepatocellular fatty degeneration and cell death. Large scale hepatocyte death was followed by impaired liver function and, consecutively, progressed to acute liver failure
Early health technology assessment during nonalcoholic steatohepatitis drug development: a two-round, cross-country, multicriteria decision analysis
Background. The assessment of value along the clinical development of new biopharmaceutical compounds is a challenging task. Complex and uncertain evidence has to be analyzed, considering a multitude of value preferences from different stakeholders. Objective. To investigate the use of multicriteria decision analysis (MCDA) to support decision making during drug development while considering payer and health technology assessment (HTA) value concerns, by applying the Advance Value Framework in nonalcoholic steatohepatitis (NASH) and testing for the consistency of the results. Design. A multiattribute value theory methodology was applied and 2 rounds of decision conferences (DCs) were organized in 3 countries (England, France, and Germany), with the participation of national key experts and stakeholders using the MACBETH questioning protocol and algorithm. A total of 51 health care professionals, patient advocates, and methodologists, including (ex-) committee members or assessors from national HTA bodies, participated in 6 DCs in the study countries. Target Population. NASH patients in fibrosis stages F2 to 3 were considered. Interventions. The value of a hypothetical product profile was assessed against 3 compounds under development using their phase 2 results. Outcome Measures. DC participants’ value preferences were elicited involving criteria selection, options scoring, and criteria weighting. Results. Highly consistent valuation rankings were observed in all DCs, always favoring the same compound. Highly consistent rankings of criteria clusters were observed, favoring therapeutic benefit criteria, followed by safety profile and innovation level criteria. Limitations. There was a lack of comparative treatment effects, early evidence on surrogate endpoints was used, and stakeholder representativeness was limited in some DCs. Conclusions. The use of MCDA is promising in supporting early HTA, illustrating high consistency in results across countries and between study rounds
Effect of intracellular lipid accumulation in a new model of non-alcoholic fatty liver disease
<p>Abstract</p> <p>Background</p> <p><it>In vitro </it>exposure of liver cells to high concentrations of free fatty acids (FFA) results in fat overload which promotes inflammatory and fibrogenic response similar to those observed in patients with Non-Alcoholic Fatty Liver Disease (NAFLD) and Non-Alcoholic Steatohepatitis (NASH). Since the mechanisms of this event have not been fully characterized, we aimed to analyze the fibrogenic stimuli in a new <it>in vitro </it>model of NASH.</p> <p>Methods</p> <p>HuH7 cells were cultured for 24 h in an enriched medium containing bovine serum albumin and increasing concentrations of palmitic and oleic acid at a molar ratio of 1:2 (palmitic and oleic acid, respectively). Cytotoxic effect, apoptosis, oxidative stress, and production of inflammatory and fibrogenic cytokines were measured.</p> <p>Results</p> <p>FFA induces a significant increment in the intracellular content of lipid droplets. The gene expression of interleukin-6, interleukin-8 and tumor necrosis factor alpha was significantly increased. The protein level of interleukin-8 was also increased. Intracellular lipid accumulation was associated to a significant up-regulation in the gene expression of transforming growth factor beta 1, alpha 2 macroglobulin, vascular endothelial growth factor A, connective tissue growth factor, insulin-like growth factor 2, thrombospondin 1. Flow cytometry analysis demonstrated a significant increment of early apoptosis and production of reactive oxygen species.</p> <p>Conclusions</p> <p>The exposure of hepatocytes to fatty acids elicits inflammation, increase of oxidative stress, apoptosis and production of fibrogenic cytokines. These data support a primary role of FFA in the pathogenesis of NAFLD and NASH.</p
Thyroid hormone receptor alpha modulates fibrogenesis in hepatic stellate cells
Objective: Progressive hepatic fibrosis can be considered the final stage of chronic liver disease. Hepatic stellate cells (HSC) play a central role in liver fibrogenesis. Thyroid hormones (TH, e.g. thyroxine; T4 and triiodothyronine; T3) significantly affect development, growth, cell differentiation and metabolism through activation of TH receptor α and/or β (TRα/β). Here, we evaluated the influence of TH in hepatic fibrogenesis. Design: Human liver tissue was obtained from explanted livers following transplantation. TRα-deficient (TRα-KO) and wild-type (WT) mice were fed a control or a profibrogenic methionine-choline deficient (MCD) diet. Liver tissue was assessed by qRT-PCR for fibrogenic gene expression. In vitro, HSC were treated with TGFβ in the presence or absence of T3. HSC with stable TRα knockdown and TRα deficient mouse embryonic fibroblasts (MEF) were used to determine receptor-specific function. Activation of HSC and MEF was assessed using the wound healing assay, Western blotting, and qRT-PCR. Results: TRα and TRβ expression is downregulated in the liver during hepatic fibrogenesis in humans and mice. TRα represents the dominant isoform in HSC. In vitro, T3 blunted TGFβ-induced expression of fibrogenic genes in HSC and abrogated wound healing by modulating TGFβ signalling, which depended on TRα presence. In vivo, TRα-KO enhanced MCD diet-induced liver fibrogenesis. Conclusion: These observations indicate that TH action in non-parenchymal cells is highly relevant. The interaction of TRα with TH regulates the phenotype of HSC via the TGFβ signalling pathway. Thus, the TH–TR axis may be a valuable target for future therapy of liver fibrosis.</p
Tanrı misafiri
Reşat Nuri'nin Türk Dünyası ve Kelebek'te tefrika edilen Tanrı Misafiri adlı romanıRoman ilk olarak 1919'da Türk Dünyası'nda tefrika edilmiş, 1923'te Kelebek'te yeniden tefrika edilmiştir.Telif hakları nedeniyle romanın tam metni verilememiştir
Inhibition of cathepsin B by caspase-3 inhibitors blocks programmed cell death in <i>Arabidopsis</i>
Programmed cell death (PCD) is used by plants for development and survival to biotic and abiotic stresses. The role of caspases in PCD is well established in animal cells. Over the past 15 years, the importance of caspase-3-like enzymatic activity for plant PCD completion has been widely documented despite the absence of caspase orthologues. In particular, caspase-3 inhibitors blocked nearly all plant PCD tested. Here, we affinity-purified a plant caspase-3-like activity using a biotin-labelled caspase-3 inhibitor and identified Arabidopsis thaliana cathepsin B3 (AtCathB3) by liquid chromatography with tandem mass spectrometry (LC-MS/MS). Consistent with this, recombinant AtCathB3 was found to have caspase-3-like activity and to be inhibited by caspase-3 inhibitors. AtCathepsin B triple-mutant lines showed reduced caspase-3-like enzymatic activity and reduced labelling with activity-based caspase-3 probes. Importantly, AtCathepsin B triple mutants showed a strong reduction in the PCD induced by ultraviolet (UV), oxidative stress (H2O2, methyl viologen) or endoplasmic reticulum stress. Our observations contribute to explain why caspase-3 inhibitors inhibit plant PCD and provide new tools to further plant PCD research. The fact that cathepsin B does regulate PCD in both animal and plant cells suggests that this protease may be part of an ancestral PCD pathway pre-existing the plant/animal divergence that needs further characterisation
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