1,177 research outputs found

    Hematological Disorders and Pulmonary Hypertension

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    Pulmonary hypertension (PH), a serious disorder with a high morbidity and mortality rate, is known to occur in a number of unrelated systemic diseases. Several hematological disorders such as sickle cell disease, thalassemia and myeloproliferative diseases develop PH which worsens the prognosis. Associated oxidant injury and vascular inflammation cause endothelial damage and dysfunction. Pulmonary vascular endothelial damage/dysfunction is an early event in PH resulting in the loss of vascular reactivity, activation of proliferative and antiapoptotic pathways leading to vascular remodeling, elevated pulmonary artery pressure, right ventricular hypertrophy and premature death. Hemolysis observed in hematological disorders leads to free hemoglobin which rapidly scavenges nitric oxide (NO), limiting its bioavailability, and leading to endothelial dysfunction. In addition, hemolysis releases arginase into the circulation which converts L-arginine to ornithine, thus bypassing NO production. Furthermore, treatments for hematological disorders such as immunosuppressive therapy, splenectomy, bone marrow transplantation, and radiation have been shown to contribute to the development of PH. Recent studies have shown deregulated iron homeostasis in patients with cardiopulmonary diseases including pulmonary arterial hypertension (PAH). Several studies have reported low iron levels in patients with idiopathic PAH, and iron deficiency is an important risk factor. This article reviews PH associated with hematological disorders and its mechanism; and iron homeostasis and its relevance to PH

    Refinement of Biomarker Pentosidine Methodology for use on Aging Birds

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    There is no reliable method for determining age for most species of long-lived birds. Recent success using the skin chemical pentosidine as a biomarker has shown promise as an aging tool for birds. Pentosidine levels have been determined only from the breast tissue of carcasses, and we sought to refine the procedure with respect to biopsy size and location for safe and effective use on living birds. We compared pentosidine concentrations in 4 skin-size samples (4, 6, 8, and 20-mm diameter biopsies) from the breast of black vulture (Coragyps atratus) carcasses. We also compared pentosidine levels from breast and patagial tissue to document potential differences among collection sites of deceased vultures (with unknown ages) and monk parakeets (Myiopsitta monachus; with actual, minimal, and unknown ages). Pentosidine concentrations (pmol pentosidine/mg collagen) were similar among the 4 sizes of vulture breast skin (P = 0.82). Pentosidine concentrations for the breast (x̄ = 8.9, SE = 0.55, n = 28) and patagium (x̄ = 8.9, SE = 0.51, n = 28) of vultures were similar, but in parakeets, pentosidine was higher in the breast (x̄ = 15.9, SE = 1.30, n = 105) than the patagium (x̄ = 11.5, SE = 1.10, n = 105). We made pentosidine-based age estimates for vultures and parakeets using a general age curve for wild birds. We also made vulture age estimates using plumage characteristics and a cormorant (Phalacrocorax auritus) age curve. Vulture pentosidine-based age estimates appear to correspond to plumage-based age estimates. Pentosidine-based age estimates for 88% of the known-aged parakeets (n = 17) were within 6 months of actual ages. Even though known ages were not available for all birds, we found a positive trend in pentosidine versus age for both species. We suggest that 6-mm diameter skin samples from the patagium of living vultures and other similar-sized birds will provide sufficient tissue for reliable age estimation and will not impair flight ability

    Frequency of Nonalcoholic Fatty Liver Disease and Subclinical Atherosclerosis Among Young Mexican Americans

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    Non-alcoholic fatty liver disease (NAFLD) is considered the hepatic manifestation of the metabolic syndrome, whose criteria are risk factors for atherosclerotic cardiovascular disease. We aimed to evaluate the prevalence of NAFLD, its association with subclinical atherosclerosis, and factors that may account for this association in Mexican Americans. In a population based cross-sectional sample drawn from the Cameron County Hispanic Cohort in Texas, carotid intima media thickness (cIMT), an indicator of subclinical atherosclerosis, was measured. Abnormal carotid ultrasound study was defined as mean cIMT \u3e75th percentile for age and gender and/or plaque presence. NAFLD was defined as steatosis by ultrasound in absence of other causes of liver disease. Multivariable weighted regression analyses were performed to evaluate associations between NAFLD and cIMT. Mean age was 50.4±1.2 years with 58.3% females. Mean body mass index (BMI) was 31.0 ± 0.4 kg/m2, and 54.0% had the metabolic syndrome. NAFLD was highly prevalent (48.80%); subjects with NAFLD had greater BMI, central obesity, fasting glucose levels, and dyslipidemia, and were more likely to have the metabolic syndrome. Nearly one third of subjects with NAFLD also had evidence of subclinical atherosclerosis (31.2%). After adjusting for covariates, there was an independent association between NAFLD and increased cIMT only in younger subjects \u3c45 years (p=0.0328). Subjects with both abnormal liver and carotid ultrasound studies tended to be obese, diabetic, and have the metabolic syndrome. In conclusion, NAFLD is highly prevalent in this Mexican American cohort, with an independent association between NAFLD and subclinical atherosclerosis among younger subjects; clustering of diabetes, obesity, and metabolic syndrome in this health disparity cohort increases the risk of both liver disease and early atherosclerosis in young adults

    The Impact of Curated Educational Videos on Pathology Health Literacy for Patients with a Pancreatic, Colorectal, or Prostate Cancer Diagnosis

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    Despite patients having increased access to their own electronic health record (EHR) in recent times, patients are often still not considered a primary audience of pathology reports. An alternative to in-person patient education is the use of multimedia programming to enhance health literacy. Curated video presentations designed to explain diagnosis-specific pathology terms were reviewed by a board-certified pathologist and oncologist team and then shown to patients with a primary diagnosis of either pancreatic, colorectal, or prostate cancer in-clinic; these patients then completed a secure electronic survey immediately afterwards. Seventy patients were surveyed, with 91% agreeing or strongly agreeing that the video they watched increased their understanding of the medical terms used in their pathology reports, with a corresponding average Likert score (ALS) of 4.21 (SD = 0.77, CI = ± 0.18). Furthermore, 95% agreed or strongly agreed that the video they watched both enhanced their understanding of the role of the pathologist in diagnosing cancer (ALS = 4.27; SD = 0.65, CI = ± 0.15) and reported they found the video useful (ALS = 4.27; SD = 0.53, CI = ± 0.13). Curated videos such as those utilized in this study have the potential to increase patient health literacy and inform patients of the multidisciplinary nature of cancer diagnosis

    Novel mutations expand the clinical spectrum of DYNC1H1-associated spinal muscular atrophy

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    OBJECTIVE To expand the clinical phenotype of autosomal dominant congenital spinal muscular atrophy with lower extremity predominance (SMA-LED) due to mutations in the dynein, cytoplasmic 1, heavy chain 1 (DYNC1H1) gene. METHODS Patients with a phenotype suggestive of a motor, non-length-dependent neuronopathy predominantly affecting the lower limbs were identified at participating neuromuscular centers and referred for targeted sequencing of DYNC1H1. RESULTS We report a cohort of 30 cases of SMA-LED from 16 families, carrying mutations in the tail and motor domains of DYNC1H1, including 10 novel mutations. These patients are characterized by congenital or childhood-onset lower limb wasting and weakness frequently associated with cognitive impairment. The clinical severity is variable, ranging from generalized arthrogryposis and inability to ambulate to exclusive and mild lower limb weakness. In many individuals with cognitive impairment (9/30 had cognitive impairment) who underwent brain MRI, there was an underlying structural malformation resulting in polymicrogyric appearance. The lower limb muscle MRI shows a distinctive pattern suggestive of denervation characterized by sparing and relative hypertrophy of the adductor longus and semitendinosus muscles at the thigh level, and diffuse involvement with relative sparing of the anterior-medial muscles at the calf level. Proximal muscle histopathology did not always show classic neurogenic features. CONCLUSION Our report expands the clinical spectrum of DYNC1H1-related SMA-LED to include generalized arthrogryposis. In addition, we report that the neurogenic peripheral pathology and the CNS neuronal migration defects are often associated, reinforcing the importance of DYNC1H1 in both central and peripheral neuronal functions

    PhotoAffinity bits : a photoaffinity-based fragment screening platform for efficient identification of protein ligands

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    Advances in genomic analyses enable the identification of new proteins that are associated with disease. To validate these targets, tool molecules are required to demonstrate that a ligand can have a disease-modifying effect. Currently, as tools are reported for only a fraction of the proteome, platforms for ligand discovery are essential to leverage insights from genomic analyses. Fragment screening offers an efficient approach to explore chemical space, however, it remains challenging to develop techniques that are both sufficiently high-throughput and sensitive. We present a fragment screening platform, termed PhABits (PhotoAffinity Bits), which utilises a library of photoreactive fragments to covalently capture fragment-protein interactions. Hits can be profiled to determine potency and site of crosslinking, and subsequently developed as reporters in a competitive displacement assay to identify novel hit matter. We envision that the PhABits will be widely applicable to novel protein targets, identifying starting points in the development of therapeutic

    Itaconate is an anti-inflammatory metabolite that activates Nrf2 via alkylation of KEAP1.

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    The endogenous metabolite itaconate has recently emerged as a regulator of macrophage function, but its precise mechanism of action remains poorly understood. Here we show that itaconate is required for the activation of the anti-inflammatory transcription factor Nrf2 (also known as NFE2L2) by lipopolysaccharide in mouse and human macrophages. We find that itaconate directly modifies proteins via alkylation of cysteine residues. Itaconate alkylates cysteine residues 151, 257, 288, 273 and 297 on the protein KEAP1, enabling Nrf2 to increase the expression of downstream genes with anti-oxidant and anti-inflammatory capacities. The activation of Nrf2 is required for the anti-inflammatory action of itaconate. We describe the use of a new cell-permeable itaconate derivative, 4-octyl itaconate, which is protective against lipopolysaccharide-induced lethality in vivo and decreases cytokine production. We show that type I interferons boost the expression of Irg1 (also known as Acod1) and itaconate production. Furthermore, we find that itaconate production limits the type I interferon response, indicating a negative feedback loop that involves interferons and itaconate. Our findings demonstrate that itaconate is a crucial anti-inflammatory metabolite that acts via Nrf2 to limit inflammation and modulate type I interferons

    Real-time large-scale dense RGB-D SLAM with volumetric fusion

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    We present a new simultaneous localization and mapping (SLAM) system capable of producing high-quality globally consistent surface reconstructions over hundreds of meters in real time with only a low-cost commodity RGB-D sensor. By using a fused volumetric surface reconstruction we achieve a much higher quality map over what would be achieved using raw RGB-D point clouds. In this paper we highlight three key techniques associated with applying a volumetric fusion-based mapping system to the SLAM problem in real time. First, the use of a GPU-based 3D cyclical buffer trick to efficiently extend dense every-frame volumetric fusion of depth maps to function over an unbounded spatial region. Second, overcoming camera pose estimation limitations in a wide variety of environments by combining both dense geometric and photometric camera pose constraints. Third, efficiently updating the dense map according to place recognition and subsequent loop closure constraints by the use of an ‘as-rigid-as-possible’ space deformation. We present results on a wide variety of aspects of the system and show through evaluation on de facto standard RGB-D benchmarks that our system performs strongly in terms of trajectory estimation, map quality and computational performance in comparison to other state-of-the-art systems.Science Foundation Ireland (Strategic Research Cluster Grant 07/SRC/I1168)Irish Research Council (Embark Initiative)United States. Office of Naval Research (Grant N00014-10-1-0936)United States. Office of Naval Research (Grant N00014-11-1-0688)United States. Office of Naval Research (Grant N00014-12-1-0093)United States. Office of Naval Research (Grant N00014-12-10020)National Science Foundation (U.S.) (Grant IIS-1318392

    Genetic Applications in Avian Conservation

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    A fundamental need in conserving species and their habitats is defining distinct entities that range from individuals to species to ecosystems and beyond (Table 1; Ryder 1986, Moritz 1994, Mayden and Wood 1995, Haig and Avise 1996, Hazevoet 1996, Palumbi and Cipriano 1998, Hebert et al. 2004, Mace 2004, Wheeler et al. 2004, Armstrong and Ball 2005, Baker 2008, Ellis et al. 2010, Winker and Haig 2010). Rapid progression in this interdisciplinary field continues at an exponential rate; thus, periodic updates on theory, techniques, and applications are important for informing practitioners and consumers of genetic information. Here, we outline conservation topics for which genetic information can be helpful, provide examples of where genetic techniques have been used best in avian conservation, and point to current technical bottlenecks that prevent better use of genomics to resolve conservation issues related to birds. We hope this review will provide geneticists and avian ecologists with a mutually beneficial dialogue on how this integrated field can solve current and future problems

    Lesson from the Stoichiometry Determination of the Cohesin Complex: A Short Protease Mediated Elution Increases the Recovery from Cross-Linked Antibody-Conjugated Beads

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    Affinity purification of proteins using antibodies coupled to beads and subsequent mass spectrometric analysis has become a standard technique for the identification of protein complexes. With the recent transfer of the isotope dilution mass spectrometry principle (IDMS) to the field of proteomics, quantitative analysesssuch as the stoichiometry determination of protein complexesshave become achievable. Traditionally proteins were eluted from antibody-conjugated beads using glycine at low pH or using diluted acids such as HCl, TFA, or FA, but elution was often found to be incomplete. Using the cohesin complex and the anaphase promoting complex/cyclosome (APC/C) as examples, we show that a short 15-60 min predigestion with a protease such as LysC (modified on-bead digest termed protease elution) increases the elution efficiency 2- to 3-fold compared to standard acid elution protocols. While longer incubation periodssas performed in standard on-bead digestionsled to partial proteolysis of the cross-linked antibodies, no or only insignificant cleavage was observed after 15-60 min protease mediated elution. Using the protease elution method, we successfully determined the stoichiometry of the cohesin complex by absolute quantification of the four core subunits using LC-SRM analysis and 19 reference peptides generated with the EtEP strategy. Protease elution was 3-fold more efficient compared to HCl elution, but measurements using both elution techniques are in agreement with
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