775 research outputs found

    Time-resolved Neutron-gamma-ray Data Acquisition for in Situ Subsurface Planetary Geochemistry

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    The current gamma-ray/neutron instrumentation development effort at NASA Goddard Space Flight Center aims to extend the use of active pulsed neutron interrogation techniques to probe the subsurface elemental composition of planetary bodies in situ. Previous NASA planetary science missions, that used neutron and/or gamma-ray spectroscopy instruments, have relied on neutrons produced from galactic cosmic rays. One of the distinguishing features of this effort is the inclusion of a high intensity 14.1 MeV pulsed neutron generator synchronized with a custom data acquisition system to time each event relative to the pulse. With usually only one opportunity to collect data, it is difficult to set a priori time-gating windows to obtain the best possible results. Acquiring time-tagged, event-by-event data from nuclear induced reactions provides raw data sets containing channel/energy, and event time for each gamma ray or neutron detected. The resulting data set can be plotted as a function of time or energy using optimized analysis windows after the data are acquired. Time windows can now be chosen to produce energy spectra that yield the most statistically significant and accurate elemental composition results that can be derived from the complete data set. The advantages of post-processing gamma-ray time-tagged event-by-event data in experimental tests using our prototype instrument will be demonstrated

    Dasatinib inhibits CXCR4 signaling in chronic lymphocytic leukaemia cells and impairs migration towards CXCL12

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    Chemokines and their ligands play a critical role in enabling chronic lymphocytic leukaemia (CLL) cells access to protective microenvironmental niches within tissues, ultimately resulting in chemoresistance and relapse: disruption of these signaling pathways has become a novel therapeutic approach in CLL. The tyrosine kinase inhibitor dasatinib inhibits migration of several cell lines from solid-organ tumours, but effects on CLL cells have not been reported. We studied the effect of clinically achievable concentrations of dasatinib on signaling induced by the chemokine CXCL12 through its' receptor CXCR4, which is highly expressed on CLL cells. Dasatinib pre-treatment inhibited Akt and ERK phosphorylation in CLL cells upon stimulation with CXCL12. Dasatinib also significantly diminished the rapid increase in actin polymerisation observed in CLL cells following CXCL12 stimulation. Moreover, the drug significantly inhibited chemotaxis in a transwell assay, and reduced the percentage of cells able to migrate beneath a CXCL12-expressing murine stromal cell line. Dasatinib also abrogated the anti-apoptotic effect of prolonged CXCL12 stimulation on cultured CLL cells. These data suggest that dasatinib, akin to other small molecule kinase inhibitors targeting the B-cell receptor signaling pathway, may redistribute CLL cells from protective tissue niches to the peripheral blood, and support the investigation of dasatinib in combination strategies

    DNA Extraction Method Development for Ocular Tissues

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    Purpose: DNA extraction kits are traditionally developed to work with liquid tissues such as blood, saliva, and swabs, but some have been proposed to work with solid tissues. Somatic variation in cancers can be important for tumor subtyping and treatment guidance, including ocular tumors. Additionally, epigenetic marks such as 5-methylcytosine (5mC) and 5-hydroxymethylcytosine (5hmC) are tissue-specific and change in disease states, particularly evident in diabetic retinopathy and age-related macular degeneration. Commercial DNA extraction kits are available from several vendors, but the various kits have different strengths and weaknesses, and the removal of PCR inhibitors will vary with each kit. This project investigates the yield and purity of DNA from ocular tissues using commercial DNA extraction kits. Methods: Cornea, neural retina, RPE/choroid layer, optic nerve, and capsular bag were collected and aliquoted into 15 mg aliquots. Extractions were performed using the following kits: DNEasy Blood and Tissue Kit (Qiagen;), GeneJET Genomic DNA Purification Kit (ThermoFisher Scientific), Monarch HMW DNA Extraction Kit for Tissue (New England Biosciences), and genomicPrep Mini Spin Kit (Cytiva). DNA was quantified using the Qubit Fluorometer and molecular weight was checked by agarose gel. Several more kits are currently being tested. Results: All four kits yielded high molecular weight DNA (above 20 kbp). The Monarch HMW kit yielded DNA with significantly higher molecular weights. The DNA yields per milligram of tissue were highest using the DNEasy Blood and Tissue Kit for optic nerve, neural retina, and RPE/choroid. The yield was highest for the cornea using the genomicPrep Mini Spin Kit. Only the genomicPrep Mini Spin Kit yielded sufficient DNA for quantification from the capsular bag, and total yields were minimal (600 ng or less). Additional kits are currently being tested, but initial results indicate that several commercial kits will be sufficient for DNA extraction of ocular tissues. Further work is needed to purify epithelial cells and stem cells from the intraocular lens. Conclusions: Of the kits tested, all are sufficient to obtain significant amounts of DNA from all ocular tissues aside from the capsular bag. The Monarch HMW yielded the highest molecular weight, but significantly lower quantities of DNA than the other kits, indicating that it may not be ideal for most purposes. Protocol development for the capsular bag is still underway

    Ischemic preconditioning protects against cardiac ischemia reperfusion injury without affecting succinate accumulation or oxidation.

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    Ischemia-reperfusion (IR) injury occurs when blood supply to an organ is disrupted and then restored, and underlies many disorders, notably myocardial infarction and stroke. While reperfusion of ischemic tissue is essential for survival, it also initiates cell death through generation of mitochondrial reactive oxygen species (ROS). Recent work has revealed a novel pathway underlying ROS production at reperfusion in vivo in which the accumulation of succinate during ischemia and its subsequent rapid oxidation at reperfusion drives ROS production at complex I by reverse electron transport (RET). Pharmacologically inhibiting ischemic succinate accumulation, or slowing succinate metabolism at reperfusion, have been shown to be cardioprotective against IR injury. Here, we determined whether ischemic preconditioning (IPC) contributes to cardioprotection by altering kinetics of succinate accumulation and oxidation during IR. Mice were subjected to a 30-minute occlusion of the left anterior descending coronary artery followed by reperfusion, with or without a protective IPC protocol prior to sustained ischemia. We found that IPC had no effect on ischemic succinate accumulation with both control and IPC mice having profound increases in succinate compared to normoxia. Furthermore, after only 1-minute reperfusion succinate was rapidly metabolised returning to near pre-ischemic levels in both groups. We conclude that IPC does not affect ischemic succinate accumulation, or its oxidation at reperfusion

    Rethinking Sustainability to Meet the Climate Change Challenge

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    A group of environmental law professors formed the Environmental Law Collaborative with the goal of engaging environmental law scholars in the thorny issues of the day. The members of the Collaborative gathered in the summer of 2012 to produce an intensive and collective assessment of sustainability in the age of climate change. Their writings examine the process of adapting the principles and application of sustainability to the demands of climate change, including framing the term sustainability in climate change discussions; coordinating sustainable practices across disciplines such as law, economics, ethics, and the hard sciences; and conceptualizing the role of sustainability in formulating adaptation and resiliency strategies. Their work also contemplates the role of law and legal systems in crafting effective climate change adaptation strategies and considers feasible strategies in the context of specific examples

    Low-level Laser Therapy to the Mouse Femur Enhances the Fungicidal Response of Neutrophils against Paracoccidioides brasiliensis

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    Neutrophils (PMN) play a central role in host defense against the neglected fungal infection paracoccidioidomycosis (PCM), which is caused by the dimorphic fungus Paracoccidioides brasiliensis (Pb). PCM is of major importance, especially in Latin America, and its treatment relies on the use of antifungal drugs. However, the course of treatment is lengthy, leading to side effects and even development of fungal resistance. the goal of the study was to use low-level laser therapy (LLLT) to stimulate PMN to fight Pb in vivo. Swiss mice with subcutaneous air pouches were inoculated with a virulent strain of Pb or fungal cell wall components (Zymosan), and then received LLLT (780 nm; 50 mW; 12.5 J/cm2; 30 seconds per point, giving a total energy of 0.5 J per point) on alternate days at two points on each hind leg. the aim was to reach the bone marrow in the femur with light. Non-irradiated animals were used as controls. the number and viability of the PMN that migrated to the inoculation site was assessed, as well as their ability to synthesize proteins, produce reactive oxygen species (ROS) and their fungicidal activity. the highly pure PMN populations obtained after 10 days of infection were also subsequently cultured in the presence of Pb for trials of protein production, evaluation of mitochondrial activity, ROS production and quantification of viable fungi growth. PMN from mice that received LLLT were more active metabolically, had higher fungicidal activity against Pb in vivo and also in vitro. the kinetics of neutrophil protein production also correlated with a more activated state. LLLT may be a safe and non-invasive approach to deal with PCM infection.Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)Fundação de Amparo à Pesquisa do Estado de Minas Gerais (FAPEMIG)National Institute of Health (US NIH)Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)Fed Univ Alfenas UNIFAL MG, Inst Biomed Sci, Dept Microbiol & Immunol, Alfenas, MG, BrazilFed Univ Alfenas UNIFAL MG, Inst Biomed Sci, Dept Biochem, Alfenas, MG, BrazilState Univ Campinas UNICAMP, Inst Biol, Dept Struct & Funct Biol, São Paulo, BrazilFed Univ São Paulo UNIFESP, Dept Microbiol Immunol & Parasitol, São Paulo, SP, BrazilMassachusetts Gen Hosp, Wellman Ctr Photomed, Boston, MA 02114 USAHarvard Univ, Sch Med, Dept Dermatol, Boston, MA 02115 USAMIT, Harvard Mit Div Hlth Sci & Technol, Cambridge, MA 02139 USAFed Univ Alfenas UNIFAL MG, Inst Biomed Sci, Dept Pathol & Parasitol, Alfenas, MG, BrazilFed Univ São Paulo UNIFESP, Dept Microbiol Immunol & Parasitol, São Paulo, SP, BrazilCNPq: 486135/2012-8CNPq: 304827/2012-6FAPEMIG: CBB-PPM-00119-14National Institute of Health (US NIH): R01AI050875CAPES: AEX-9765-14-0Web of Scienc

    The PI3-kinase delta inhibitor idelalisib (GS-1101) targets integrin-mediated adhesion of chronic lymphocytic leukemia (CLL) cell to endothelial and marrow stromal cells

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    CLL cell trafficking between blood and tissue compartments is an integral part of the disease process. Idelalisib, a phosphoinositide 3-kinase delta (PI3K\u3b4) inhibitor causes rapid lymph node shrinkage, along with an increase in lymphocytosis, prior to inducing objective responses in CLL patients. This characteristic activity presumably is due to CLL cell redistribution from tissues into the blood, but the underlying mechanisms are not fully understood. We therefore analyzed idelalisib effects on CLL cell adhesion to endothelial and bone marrow stromal cells (EC, BMSC). We found that idelalisib inhibited CLL cell adhesion to EC and BMSC under static and shear flow conditions. TNF\u3b1-induced VCAM-1 (CD106) expression in supporting layers increased CLL cell adhesion and accentuated the inhibitory effect of idelalisib. Co-culture with EC and BMSC also protected CLL from undergoing apoptosis, and this EC- and BMSC-mediated protection was antagonized by idelalisib. Furthermore, we demonstrate that CLL cell adhesion to EC and VLA-4 (CD49d) resulted in the phosphorylation of Akt, which was sensitive to inhibition by idelalisib. These findings demonstrate that idelalisib interferes with integrin-mediated CLL cell adhesion to EC and BMSC, providing a novel mechanism to explain idelalisib-induced redistribution of CLL cells from tissues into the blood

    Developing core sets for persons following amputation based on the International Classification of Functioning, Disability and Health as a way to specify functioning

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    Amputation is a common late stage sequel of peripheral vascular disease and diabetes or a sequel of accidental trauma, civil unrest and landmines. The functional impairments affect many facets of life including but not limited to: Mobility; activities of daily living; body image and sexuality. Classification, measurement and comparison of the consequences of amputations has been impeded by the limited availability of internationally, multiculturally standardized instruments in the amputee setting. The introduction of the International Classification of Functioning, Disability and Health (ICF) by the World Health Assembly in May 2001 provides a globally accepted framework and classification system to describe, assess and compare function and disability. In order to facilitate the use of the ICF in everyday clinical practice and research, ICF core sets have been developed that focus on specific aspects of function typically associated with a particular disability. The objective of this paper is to outline the development process for the ICF core sets for persons following amputation. The ICF core sets are designed to translate the benefits of the ICF into clinical routine. The ICF core sets will be defined at a Consensus conference which will integrate evidence from preparatory studies, namely: (a) a systematic literature review regarding the outcome measures of clinical trails and observational studies, (b) semi-structured patient interviews, (c) international experts participating in an internet-based survey, and (d) cross-sectional, multi-center studies for clinical applicability. To validate the ICF core sets field-testing will follow. Invitation for participation: The development of ICF Core Sets is an inclusive and open process. Anyone who wishes to actively participate in this process is invited to do so
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