22 research outputs found

    STIM1, an essential and conserved component of store-operated Ca2+ channel function

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    Store-operated Ca2+ (SOC) channels regulate many cellular processes, but the underlying molecular components are not well defined. Using an RNA interference (RNAi)-based screen to identify genes that alter thapsigargin (TG)-dependent Ca2+ entry, we discovered a required and conserved role of Stim in SOC influx. RNAi-mediated knockdown of Stim in Drosophila S2 cells significantly reduced TG-dependent Ca2+ entry. Patch-clamp recording revealed nearly complete suppression of the Drosophila Ca2+ release-activated Ca2+ (CRAC) current that has biophysical characteristics similar to CRAC current in human T cells. Similarly, knockdown of the human homologue STIM1 significantly reduced CRAC channel activity in Jurkat T cells. RNAi-mediated knockdown of STIM1 inhibited TG- or agonist-dependent Ca2+ entry in HEK293 or SH-SY5Y cells. Conversely, overexpression of STIM1 in HEK293 cells modestly enhanced TG-induced Ca2+ entry. We propose that STIM1, a ubiquitously expressed protein that is conserved from Drosophila to mammalian cells, plays an essential role in SOC influx and may be a common component of SOC and CRAC channels

    Potential improvements in global carbon flux estimates from a network of laser heterodyne radiometer measurements of column carbon dioxide

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    We present observing system simulation experiments (OSSEs) to evaluate the impact of a proposed network of ground-based miniaturized laser heterodyne radiometer (mini-LHR) instruments that measure atmospheric column-averaged carbon dioxide (XCO2) with a 1 ppm precision. A particular strength of this passive measurement approach is its insensitivity to clouds and aerosols due to its direct sun pointing and narrow field of view (0.2). Developed at the NASA Goddard Space Flight Center (GSFC), these portable, low-cost mini-LHR instruments were designed to operate in tandem with the sun photometers used by the AErosol RObotic NETwork (AERONET). This partnership allows us to leverage the existing framework of AERONET's global ground network of more than 500 sites as well as providing simultaneous measurements of aerosols that are known to be a major source of error in retrievals of XCO2 from passive nadir-viewing satellite observations. We show, using the global 3-D GEOS-Chem chemistry transport model, that a deployment of 50 mini-LHRs at strategic (but not optimized) AERONET sites significantly improves our knowledge of global and regional land-based CO2 fluxes. This improvement varies seasonally and ranges 58%81% over southern lands, 47%76% over tropical lands, 71%92% over northern lands, and 64%91% globally. We also show significant added value from combining mini-LHR instruments with the existing ground-based NOAA flask network. Collectively, these data result in improved a posteriori CO2 flux estimates on spatial scales of 10 km2, especially over North America and Europe, where the ground-based networks are densest. Our studies suggest that the mini-LHR network could also play a substantive role in reducing carbon flux uncertainty in Arctic and tropical systems by filling in geographical gaps in measurements left by ground-based networks and space-based observations. A realized network would also provide necessary data for the quinquennial global stock takes that form part of the Paris Agreement

    Modulation of γ-Secretase Reduces β-Amyloid Deposition in a Transgenic Mouse Model of Alzheimer's Disease

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    SummaryAlzheimer's disease (AD) is characterized pathologically by the abundance of senile plaques and neurofibrillary tangles in the brain. We synthesized over 1200 novel gamma-secretase modulator (GSM) compounds that reduced Aβ42 levels without inhibiting epsilon-site cleavage of APP and Notch, the generation of the APP and Notch intracellular domains, respectively. These compounds also reduced Aβ40 levels while concomitantly elevating levels of Aβ38 and Aβ37. Immobilization of a potent GSM onto an agarose matrix quantitatively recovered Pen-2 and to a lesser degree PS-1 NTFs from cellular extracts. Moreover, oral administration (once daily) of another potent GSM to Tg 2576 transgenic AD mice displayed dose-responsive lowering of plasma and brain Aβ42; chronic daily administration led to significant reductions in both diffuse and neuritic plaques. These effects were observed in the absence of Notch-related changes (e.g., intestinal proliferation of goblet cells), which are commonly associated with repeated exposure to functional gamma-secretase inhibitors (GSIs)

    Modelling human choices: MADeM and decision‑making

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    Research supported by FAPESP 2015/50122-0 and DFG-GRTK 1740/2. RP and AR are also part of the Research, Innovation and Dissemination Center for Neuromathematics FAPESP grant (2013/07699-0). RP is supported by a FAPESP scholarship (2013/25667-8). ACR is partially supported by a CNPq fellowship (grant 306251/2014-0)

    26th Annual Computational Neuroscience Meeting (CNS*2017): Part 3 - Meeting Abstracts - Antwerp, Belgium. 15–20 July 2017

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    This work was produced as part of the activities of FAPESP Research,\ud Disseminations and Innovation Center for Neuromathematics (grant\ud 2013/07699-0, S. Paulo Research Foundation). NLK is supported by a\ud FAPESP postdoctoral fellowship (grant 2016/03855-5). ACR is partially\ud supported by a CNPq fellowship (grant 306251/2014-0)

    A Simple and Effective Method for Administration of Blood Cardioplegia

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    A simple blood cardioplegia delivery system is described that is capable of delivering cardioplegia solution at any designated temperature between go C. and 37° C. Specific ratios of blood to crystalloid solution are possible. Infusion pressure monitoring is simple. It is relatively inexpensive and can be easily utilized with available equipment

    Right Ventricular Assist with Conventional Cardiopulmonary Bypass Equipment

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    A technique of supporting a patient with perioperative right ventricular failure has been developed and used clinically. The method is simple, inexpensive, effective, and involves only conventional cardiopulmonary bypass equipment
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