1,176 research outputs found

    Mitochondria, Amyloid β, and Alzheimer's Disease

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    Hypometabolism is a hallmark of Alzheimer's disease (AD) and implicates a mitochondrial role in the neuropathology associated with AD. Mitochondrial amyloid-beta (Aβ) accumulation precedes extracellular Aβ deposition. In addition to increasing oxidative stress, Aβ has been shown to directly inhibit mitochondrial enzymes. Inhibition of mitochondrial enzymes as a result of oxidative damage or Aβ interaction perpetuates oxidative stress and leads to a hypometabolic state. Additionally, Aβ has also been shown to interact with cyclophilin D, a component of the mitochondrial permeability transition pore, which may promote cell death. Therefore, ample evidence exists indicating that the mitochondrion plays a vital role in the pathophysiology observed in AD

    Identification and cost of adverse events in metastatic breast cancer in taxane and capecitabine based regimens.

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    PurposeWe sought to compare the economic impact of treatment-related adverse events (AEs) in patients with metastatic breast cancer (mBC) using taxane- or capecitabine-based treatment regimens as either first- or second-line (FL or SL) therapy in the US.MethodsWe used healthcare claims data from the Truven Health Analytics MarketScan® Commercial Databases to conduct a retrospective cohort study comparing the economic impact of AEs amongst taxane- and capecitabine-treated mBC patients in the US. We selected women diagnosed with mBC between 2008-2010 who received a taxane or capecitabine as first- or second-line (FL or SL) chemotherapy. Costs related to hospitalization, outpatient services, emergency department visits, chemotherapy and other medications were tabulated and combined to determine total healthcare costs. The incremental monthly costs associated with the presence of AEs compared to no AEs were estimated using generalized linear models, controlling for age and Charlson Comorbidity Index.ResultsWe identified 15,443 mBC patients meeting inclusion criteria. Adjusted total monthly costs were significantly higher in those who experienced AEs than in those without AEs in both lines of treatment (FL incremental cost: taxanes 1,142,capecitabine1,142, capecitabine 1,817; SL incremental cost: taxanes 1,448,capecitabine1,448, capecitabine 4,437). Total costs increased with the number of AEs and were primarily driven by increased hospitalization amongst those with AEs.ConclusionsAdverse events in taxane- or capecitabine-treated mBC patients are associated with significant increases in costs. Selecting treatment options associated with fewer AEs may reduce costs and improve outcomes in these patients

    Genetic Approach to Elucidate the Role of Cyclophilin D in Traumatic Brain Injury Pathology

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    Cyclophilin D (CypD) has been shown to play a critical role in mitochondrial permeability transition pore (mPTP) opening and the subsequent cell death cascade. Studies consistently demonstrate that mitochondrial dysfunction, including mitochondrial calcium overload and mPTP opening, is essential to the pathobiology of cell death after a traumatic brain injury (TBI). CypD inhibitors, such as cyclosporin A (CsA) or NIM811, administered following TBI, are neuroprotective and quell neurological deficits. However, some pharmacological inhibitors of CypD have multiple biological targets and, as such, do not directly implicate a role for CypD in arbitrating cell death after TBI. Here, we reviewed the current understanding of the role CypD plays in TBI pathobiology. Further, we directly assessed the role of CypD in mediating cell death following TBI by utilizing mice lacking the CypD encoding gene Ppif. Following controlled cortical impact (CCI), the genetic knockout of CypD protected acute mitochondrial bioenergetics at 6 h post-injury and reduced subacute cortical tissue and hippocampal cell loss at 18 d post-injury. The administration of CsA following experimental TBI in Ppif-/- mice improved cortical tissue sparing, highlighting the multiple cellular targets of CsA in the mitigation of TBI pathology. The loss of CypD appeared to desensitize the mitochondrial response to calcium burden induced by TBI; this maintenance of mitochondrial function underlies the observed neuroprotective effect of the CypD knockout. These studies highlight the importance of maintaining mitochondrial homeostasis after injury and validate CypD as a therapeutic target for TBI. Further, these results solidify the beneficial effects of CsA treatment following TBI

    Editorial: Edema in heart failure with reduced ejection fraction

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    New mouse model of pulmonary hypertension induced by respiratory syncytial virus bronchiolitis

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    © 2018 American Physiological Society. All rights reserved. Pulmonary hypertension (PH) has been observed in up to 75% of infants with moderate to severe respiratory syncytial virus (RSV) bronchiolitis and is associated with significant morbidity and mortality in infants with congenital heart disease. The purpose of the present study was to establish a mouse model of PH secondary to RSV bronchiolitis that mimics the disease etiology as it occurs in infants. Neonatal mice were infected with RSV at 5 days of age and then reinfected 4 wk later. Serum-free medium was administered to age-matched mice as a control. Echocardiography and right ventricular systolic pressure (RVSP) measurements via right jugular vein catheterization were conducted 5 and 6 days after the second infection, respectively. Peripheral capillary oxygen saturation monitoring did not indicate hypoxia at 2–4 days post-RSV infection, before reinfection, and at 2–7 days after reinfection. RSV-infected mice had significantly higher RVSP than control mice. Pulsed-wave Doppler recording of the pulmonary blood flow by echocardiogram demonstrated a significantly shortened pulmonary artery acceleration time and decreased pulmonary artery acceleration time-to-ejection time ratio in RSV-infected mice. Morphometry showed that RSV-infected mice exhibited a significantly higher pulmonary artery medial wall thickness and had an increased number of muscularized pulmonary arteries compared with control mice. These findings, confirmed by RVSP measurements, demonstrate the development of PH in the lungs of mice infected with RSV as neonates. This animal model can be used to study the pathogenesis of PH secondary to RSV bronchiolitis and to assess the effect of treatment interventions. NEW & NOTEWORTHY This is the first mouse model of respiratory syncytial virus-induced pulmonary hypertension, to our knowledge. This model will allow us to decipher molecular mechanisms responsible for the pathogenesis of pulmonary hypertension secondary to respiratory syncytial virus bronchiolitis with the use of knockout and/or transgenic animals and to monitor therapeutic effects with echocardiography

    Experimental study of the role of physicochemical surface processing on the IN ability of mineral dust particles

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    During the measurement campaign FROST 2 (FReezing Of duST 2), the Leipzig Aerosol Cloud Interaction Simulator (LACIS) was used to investigate the influence of various surface modifications on the ice nucleating ability of Arizona Test Dust (ATD) particles in the immersion freezing mode. The dust particles were exposed to sulfuric acid vapor, to water vapor with and without the addition of ammonia gas, and heat using a thermodenuder operating at 250 °C. Size selected, quasi monodisperse particles with a mobility diameter of 300 nm were fed into LACIS and droplets grew on these particles such that each droplet contained a single particle. Temperature dependent frozen fractions of these droplets were determined in a temperature range between −40 °C ≤T≤−28 °C. The pure ATD particles nucleated ice over a broad temperature range with their freezing behavior being separated into two freezing branches characterized through different slopes in the frozen fraction vs. temperature curves. Coating the ATD particles with sulfuric acid resulted in the particles' IN potential significantly decreasing in the first freezing branch (T>−35 °C) and a slight increase in the second branch (T≤−35 °C). The addition of water vapor after the sulfuric acid coating caused the disappearance of the first freezing branch and a strong reduction of the IN ability in the second freezing branch. The presence of ammonia gas during water vapor exposure had a negligible effect on the particles' IN ability compared to the effect of water vapor. Heating in the thermodenuder led to a decreased IN ability of the sulfuric acid coated particles for both branches but the additional heat did not or only slightly change the IN ability of the pure ATD and the water vapor exposed sulfuric acid coated particles. In other words, the combination of both sulfuric acid and water vapor being present is a main cause for the ice active surface features of the ATD particles being destroyed. A possible explanation could be the chemical transformation of ice active metal silicates to metal sulfates. The strongly enhanced reaction between sulfuric acid and dust in the presence of water vapor and the resulting significant reductions in IN potential are of importance for atmospheric ice cloud formation. Our findings suggest that the IN concentration can decrease by up to one order of magnitude for the conditions investigated