146 research outputs found

    α1-Antitrypsin deficiency

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    1-Antitrypsin deficiency (A1ATD) is an inherited disorder caused by mutations in SERPINA1, leading to liver and lung disease. It is not a rare disorder but frequently goes underdiagnosed or misdiagnosed as asthma, chronic obstructive pulmonary disease (COPD) or cryptogenic liver disease. The most frequent disease-associated mutations include the S allele and the Z allele of SERPINA1, which lead to the accumulation of misfolded α1-antitrypsin in hepatocytes, endoplasmic reticulum stress, low circulating levels of α1-antitrypsin and liver disease. Currently, there is no cure for severe liver disease and the only management option is liver transplantation when liver failure is life-threatening. A1ATD-associated lung disease predominately occurs in adults and is caused principally by inadequate protease inhibition. Treatment of A1ATD-associated lung disease includes standard therapies that are also used for the treatment of COPD, in addition to the use of augmentation therapy (that is, infusions of human plasma-derived, purified α1-antitrypsin). New therapies that target the misfolded α1-antitrypsin or attempt to correct the underlying genetic mutation are currently under development

    C16 ceramide is crucial for triacylglycerol-induced apoptosis in macrophages

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    Triacylglycerol (TG) accumulation caused by adipose triglyceride lipase (ATGL) deficiency or very low-density lipoprotein (VLDL) loading of wild-type (Wt) macrophages results in mitochondrial-mediated apoptosis. This phenotype is correlated to depletion of Ca2+ from the endoplasmic reticulum (ER), an event known to induce the unfolded protein response (UPR). Here, we show that ER stress in TG-rich macrophages activates the UPR, resulting in increased abundance of the chaperone GRP78/BiP, the induction of pancreatic ER kinase-like ER kinase, phosphorylation and activation of eukaryotic translation initiation factor 2A, the translocation of activating transcription factor (ATF)4 and ATF6 to the nucleus and the induction of the cell death executor CCAAT/enhancer-binding protein homologous protein. C16:0 ceramide concentrations were increased in Atgl–/– and VLDL-loaded Wt macrophages. Overexpression of ceramide synthases was sufficient to induce mitochondrial apoptosis in Wt macrophages. In accordance, inhibition of ceramide synthases in Atgl–/– macrophages by fumonisin B1 (FB1) resulted in specific inhibition of C16:0 ceramide, whereas intracellular TG concentrations remained high. Although the UPR was still activated in Atgl–/– macrophages, FB1 treatment rescued Atgl–/– macrophages from mitochondrial dysfunction and programmed cell death. We conclude that C16:0 ceramide elicits apoptosis in Atgl–/– macrophages by activation of the mitochondrial apoptosis pathway

    Assessing Quality of Care of Elderly Patients Using the ACOVE Quality Indicator Set: A Systematic Review

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    Background: Care of the elderly is recognized as an increasingly important segment of health care. The Assessing Care Of Vulnerable Elderly (ACOVE) quality indicators (QIs) were developed to assess and improve the care of elderly patients. Objectives: The purpose of this review is to summarize studies that assess the quality of care using QIs from or based on ACOVE, in order to evaluate the state of quality of care for the reported conditions. Methods: We systematically searched MEDLINE, EMBASE and CINAHL for English-language studies indexed by February 2010. Articles were included if they used any ACOVE QIs, or adaptations thereof, for assessing the quality of care. Included studies were analyzed and relevant information was extracted. We summarized the results of these studies, and when possible generated an overall conclusion about the quality of care as measured by ACOVE for each condition, in various settings, and for each QI. Results: Seventeen studies were included with 278 QIs (original, adapted or newly developed). The quality scores showed large variation between and within conditions. Only a few conditions showed a stable pass rate range over multiple studies. Overall, pass rates for dementia (interquartile range (IQR): 11%-35%), depression (IQR: 27%-41%), osteoporosis (IQR: 34%-43%) and osteoarthritis (IQR: 29-41%) were notably low. Medication management and use (range: 81%-90%), hearing loss (77%-79%) and continuity of care (76%-80%) scored higher than other conditions. Out of the 278 QIs, 141 (50%) had mean pass rates below 50% and 121 QIs (44%) had pass rates above 50%. Twenty-three percent of the QIs scored above 75%, and 16% scored below 25%. Conclusions: Quality of care per condition varies markedly across studies. Although there has been much effort in improving the care for elderly patients in the last years, the reported quality of care according to the ACOVE indicators is still relatively lo

    Measurement of the Bottom-Strange Meson Mixing Phase in the Full CDF Data Set

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    We report a measurement of the bottom-strange meson mixing phase \beta_s using the time evolution of B0_s -> J/\psi (->\mu+\mu-) \phi (-> K+ K-) decays in which the quark-flavor content of the bottom-strange meson is identified at production. This measurement uses the full data set of proton-antiproton collisions at sqrt(s)= 1.96 TeV collected by the Collider Detector experiment at the Fermilab Tevatron, corresponding to 9.6 fb-1 of integrated luminosity. We report confidence regions in the two-dimensional space of \beta_s and the B0_s decay-width difference \Delta\Gamma_s, and measure \beta_s in [-\pi/2, -1.51] U [-0.06, 0.30] U [1.26, \pi/2] at the 68% confidence level, in agreement with the standard model expectation. Assuming the standard model value of \beta_s, we also determine \Delta\Gamma_s = 0.068 +- 0.026 (stat) +- 0.009 (syst) ps-1 and the mean B0_s lifetime, \tau_s = 1.528 +- 0.019 (stat) +- 0.009 (syst) ps, which are consistent and competitive with determinations by other experiments.Comment: 8 pages, 2 figures, Phys. Rev. Lett 109, 171802 (2012

    4-oxo-N-(4-hydroxyphenyl)retinamide: Two Independent Ways to Kill Cancer Cells

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    BACKGROUND: The retinoid 4-oxo-N-(4-hydroxyphenyl)retinamide (4-oxo-4-HPR) is a polar metabolite of fenretinide (4-HPR) very effective in killing cancer cells of different histotypes, able to inhibit 4-HPR-resistant cell growth and to act synergistically in combination with the parent drug. Unlike 4-HPR and other retinoids, 4-oxo-4-HPR inhibits tubulin polymerization, leading to multipolar spindle formation and mitotic arrest. Here we investigated whether 4-oxo-4-HPR, like 4-HPR, triggered cell death also via reactive oxygen species (ROS) generation and whether its antimicrotubule activity was related to a ROS-dependent mechanism in ovarian (A2780), breast (T47D), cervical (HeLa) and neuroblastoma (SK-N-BE) cancer cell lines. METHODOLOGY/PRINCIPAL FINDINGS: We provided evidence that 4-oxo-4-HPR, besides acting as an antimicrotubule agent, induced apoptosis through a signaling cascade starting from ROS generation and involving endoplasmic reticulum (ER) stress response, Jun N-terminal Kinase (JNK) activation, and upregulation of the proapoptotic PLAcental Bone morphogenetic protein (PLAB). Through time-course analysis and inhibition of the ROS-related signaling pathway (upstream by vitamin C and downstream by PLAB silencing), we demonstrated that the antimitotic activity of 4-oxo-4-HPR was independent from the oxidative stress induced by the retinoid. In fact, ROS generation occurred earlier than mitotic arrest (within 30 minutes and 2 hours, respectively) and abrogation of the ROS-related signaling pathway did not prevent the 4-oxo-4-HPR-induced mitotic arrest. CONCLUSIONS/SIGNIFICANCE: These data indicate that 4-oxo-4-HPR anticancer activity is due to at least two independent mechanisms and provide an explanation of the ability of 4-oxo-4-HPR to be more potent than the parent drug and to be effective also in 4-HPR-resistant cell lines. In addition, the double mechanism of action could allow 4-oxo-4-HPR to efficiently target tumour and to eventually counteract the development of drug resistance

    Intracoronary versus intravenous abciximab in ST-segment elevation myocardial infarction: rationale and design of the CICERO trial in patients undergoing primary percutaneous coronary intervention with thrombus aspiration

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    <p>Abstract</p> <p>Background</p> <p>Administration of abciximab during primary percutaneous coronary intervention is an effective adjunctive therapy in the treatment of patients with ST-segment elevation myocardial infarction. Recent small-scaled studies have suggested that intracoronary administration of abciximab during primary percutaneous coronary intervention is superior to conventional intravenous administration. This study has been designed to investigate whether intracoronary bolus administration of abciximab is more effective than intravenous bolus administration in improving myocardial perfusion in patients with ST-segment elevation myocardial infarction undergoing primary percutaneous coronary intervention with thrombus aspiration.</p> <p>Methods/Design</p> <p>The Comparison of IntraCoronary versus intravenous abciximab administration during Emergency Reperfusion Of ST-segment elevation myocardial infarction (CICERO) trial is a single-center, prospective, randomized open-label trial with blinded evaluation of endpoints. A total of 530 patients with STEMI undergoing primary percutaneous coronary intervention are randomly assigned to either an intracoronary or intravenous bolus of weight-adjusted abciximab. The primary end point is the incidence of >70% ST-segment elevation resolution. Secondary end points consist of post-procedural residual ST-segment deviation, myocardial blush grade, distal embolization, enzymatic infarct size, in-hospital bleeding, and clinical outcome at 30 days and 1 year.</p> <p>Discussion</p> <p>The CICERO trial is the first clinical trial to date to verify the effect of intracoronary versus intravenous administration of abciximab on myocardial perfusion in patients with ST-segment elevation myocardial infarction undergoing primary percutaneous coronary intervention with thrombus aspiration.</p> <p>Trial registration</p> <p>ClinicalTrials.gov NCT00927615</p

    Protective paraspeckle hyper-assembly downstream of TDP-43 loss of function in amyotrophic lateral sclerosis

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    Background Paraspeckles are subnuclear bodies assembled on a long non-coding RNA (lncRNA) NEAT1. Their enhanced formation in spinal neurons of sporadic amyotrophic lateral sclerosis (ALS) patients has been reported but underlying mechanisms are unknown. The majority of ALS cases are characterized by TDP-43 proteinopathy. In current study we aimed to establish whether and how TDP-43 pathology may augment paraspeckle assembly. Methods Paraspeckle formation in human samples was analysed by RNA-FISH and laser capture microdissection followed by qRT-PCR. Mechanistic studies were performed in stable cell lines, mouse primary neurons and human embryonic stem cell-derived neurons. Loss and gain of function for TDP-43 and other microRNA pathway factors were modelled by siRNA-mediated knockdown and protein overexpression. Results We show that de novo paraspeckle assembly in spinal neurons and glial cells is a hallmark of both sporadic and familial ALS with TDP-43 pathology. Mechanistically, loss of TDP-43 but not its cytoplasmic accumulation or aggregation augments paraspeckle assembly in cultured cells. TDP-43 is a component of the microRNA machinery, and recently, paraspeckles have been shown to regulate pri-miRNA processing. Consistently, downregulation of core protein components of the miRNA pathway also promotes paraspeckle assembly. In addition, depletion of these proteins or TDP-43 results in accumulation of endogenous dsRNA and activation of type I interferon response which also stimulates paraspeckle formation. We demonstrate that human or mouse neurons in vitro lack paraspeckles, but a synthetic dsRNA is able to trigger their de novo formation. Finally, paraspeckles are protective in cells with compromised microRNA/dsRNA metabolism, and their assembly can be promoted by a small-molecule microRNA enhancer. Conclusions Our study establishes possible mechanisms behind paraspeckle hyper-assembly in ALS and suggests their utility as therapeutic targets in ALS and other diseases with abnormal metabolism of microRNA and dsRNA

    3′,4′-dihydroxyflavonol ameliorates endoplasmic reticulum stress-induced apoptosis and endothelial dysfunction in mice

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    Endoplasmic reticulum (ER) stress has been implicated in the development of hypertension 3 through the induction of endothelial impairment. As 3′,4′-dihydroxyflavonol (DiOHF) 4 reduces vascular injury caused by ischaemia/reperfusion or diabetes, and flavonols have been demonstrated to attenuate ER stress, we investigated whether DiOHF can protect mice from ER stress-induced endothelial dysfunction. Male C57BLK/6 J mice were injected with tunicamycin to induce ER stress in the presence or absence of either DiOHF or tauroursodeoxycholic acid (TUDCA), an inhibitor of ER stress. Tunicamycin elevated blood pressure and impaired endothelium-dependent relaxation. Moreover, in aortae there was evidence of ER stress, oxidative stress and reduced NO production. This was coincident with increased NOX2 expression and reduced phosphorylation of endothelial nitric oxide synthase (eNOS) on Ser1176. Importantly, the effects of tunicamycin were significantly ameliorated by DiOHF or TUDCA. DiOHF also inhibited tunicamycin-induced ER stress and apoptosis in cultured human endothelial cells (HUVEC). These results provide evidence that ER stress is likely an important initiator of endothelial dysfunction through the induction of oxidative stress and a reduction in NO synthesis and that DiOHF directly protects against ER stress- induced injury. DiOHF may be useful to prevent ER and oxidative stress to preserve endothelial function, for example in hypertension

    Protective paraspeckle hyper-assembly downstream of TDP-43 loss of function in amyotrophic lateral sclerosis

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    BACKGROUND: Paraspeckles are subnuclear bodies assembled on a long non-coding RNA (lncRNA) NEAT1. Their enhanced formation in spinal neurons of sporadic amyotrophic lateral sclerosis (ALS) patients has been reported but underlying mechanisms are unknown. The majority of ALS cases are characterized by TDP-43 proteinopathy. In current study we aimed to establish whether and how TDP-43 pathology may augment paraspeckle assembly. METHODS: Paraspeckle formation in human samples was analysed by RNA-FISH and laser capture microdissection followed by qRT-PCR. Mechanistic studies were performed in stable cell lines, mouse primary neurons and human embryonic stem cell-derived neurons. Loss and gain of function for TDP-43 and other microRNA pathway factors were modelled by siRNA-mediated knockdown and protein overexpression. RESULTS: We show that de novo paraspeckle assembly in spinal neurons and glial cells is a hallmark of both sporadic and familial ALS with TDP-43 pathology. Mechanistically, loss of TDP-43 but not its cytoplasmic accumulation or aggregation augments paraspeckle assembly in cultured cells. TDP-43 is a component of the microRNA machinery, and recently, paraspeckles have been shown to regulate pri-miRNA processing. Consistently, downregulation of core protein components of the miRNA pathway also promotes paraspeckle assembly. In addition, depletion of these proteins or TDP-43 results in accumulation of endogenous dsRNA and activation of type I interferon response which also stimulates paraspeckle formation. We demonstrate that human or mouse neurons in vitro lack paraspeckles, but a synthetic dsRNA is able to trigger their de novo formation. Finally, paraspeckles are protective in cells with compromised microRNA/dsRNA metabolism, and their assembly can be promoted by a small-molecule microRNA enhancer. CONCLUSIONS: Our study establishes possible mechanisms behind paraspeckle hyper-assembly in ALS and suggests their utility as therapeutic targets in ALS and other diseases with abnormal metabolism of microRNA and dsRNA
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