370 research outputs found

    Cutting-edge biotechnological advancement in islet delivery using pancreatic and cellular approaches.

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    There are approximately 1 billion prediabetic people worldwide, and the global cost for diabetes mellitus (DM) is estimated to be $825 billion. In regard to Type 1 DM, transplanting a whole pancreas or its islets has gained the attention of researchers in the last few decades. Recent studies showed that islet transplantation (ILT) containing insulin-producing β cells is the most notable advancement cure for Type 1 DM. However, this procedure has been hindered by shortage and lack of sufficient islet donors and the need for long-term immunosuppression of any potential graft rejection. The strategy of encapsulation may avoid the rejection of stem-cell-derived allogeneic islets or xenogeneic islets. This review article describes various biotechnology features in encapsulation-of-islet-cell therapy for humans, including the use of bile acids

    The fundamental pro-groupoid of an affine 2-scheme

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    A natural question in the theory of Tannakian categories is: What if you don't remember \Forget? Working over an arbitrary commutative ring RR, we prove that an answer to this question is given by the functor represented by the \'etale fundamental groupoid \pi_1(\spec(R)), i.e.\ the separable absolute Galois group of RR when it is a field. This gives a new definition for \'etale \pi_1(\spec(R)) in terms of the category of RR-modules rather than the category of \'etale covers. More generally, we introduce a new notion of "commutative 2-ring" that includes both Grothendieck topoi and symmetric monoidal categories of modules, and define a notion of π1\pi_1 for the corresponding "affine 2-schemes." These results help to simplify and clarify some of the peculiarities of the \'etale fundamental group. For example, \'etale fundamental groups are not "true" groups but only profinite groups, and one cannot hope to recover more: the "Tannakian" functor represented by the \'etale fundamental group of a scheme preserves finite products but not all products.Comment: 46 pages + bibliography. Diagrams drawn in Tik

    Reality TV as a trigger of everyday political talk in the net-based public sphere

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    It is news journalism that is commonly considered the practice that reports on the political and invites us to act as citizens. However, there are other media genres, forms and content that may provoke the citizen in us. They not only provide talking points but also facilitate communicative spaces whereby active audiences transform into deliberating publics by bridging their knowledge, identities and experiences to society through everyday, informal political talk. The internet provides a public space whereby this everyday-life politicization can occur bottom-up. This article addresses this process of politicization in the context of political talk and discusses the boundaries between private and public by examining how it emerges in forums dedicated to British popular reality TV programmes. The article pays particular attention to the shift from non-political talk to the lifestyle-based political issues and the more conventional political topics that arise, and explores the triggers of such talk

    Efficacy of Memantine for Agitation in Alzheimer’s Dementia: A Randomised Double-Blind Placebo Controlled Trial

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    Agitation in Alzheimer's disease (AD) is common and associated with poor patient life-quality and carer distress. The best evidence-based pharmacological treatments are antipsychotics which have limited benefits with increased morbidity and mortality. There are no memantine trials in clinically significant agitation but post-hoc analyses in other populations found reduced agitation. We tested the primary hypothesis, memantine is superior to placebo for clinically significant agitation, in patients with moderate-to-severe AD

    Accumulation of Endogenous LITAF in Aggresomes

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    LITAF is a 161 amino acid cellular protein which includes a proline rich N-terminus and a conserved C-terminal domain known as the simple-like domain. Mutations in LITAF have been identified in Charcot-Marie tooth disease, a disease characterized by protein aggregates. Cells transfected with cellular LITAF reveal that LITAF is localized to late endosomes/lysosomes. Here we investigated the intracellular localization of endogenous LITAF. We demonstrated that endogenous LITAF accumulates at a discrete cytoplasmic site in BGMK cells that we identify as the aggresome. To determine the domain within LITAF that is responsible for the localization of LITAF to aggresomes, we created a construct that contained the C-terminal simple-like domain of LITAF and found that this construct also localizes to aggresomes. These data suggest the simple-like domain is responsible for targeting endogenous LITAF to the aggresome

    Neurotrophic requirements of human motor neurons defined using amplified and purified stem-cell derived cultures

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    Neurotrophic requirements of human motor neurons defined using amplified and purified stem-cell derived culturesHuman motor neurons derived from embryonic and induced pluripotent stem cells (hESCs and hiPSCs) are a potentially important tool for studying motor neuron survival and pathological cell death. However, their basic survival requirements remain poorly characterized. Here, we sought to optimize a robust survival assay and characterize their response to different neurotrophic factors. First, to increase motor neuron yield, we screened a small-molecule collection and found that the Rho-associated kinase (ROCK) inhibitor Y-27632 enhances motor neuron progenitor proliferation up to 4-fold in hESC and hiPSC cultures. Next, we FACS-purified motor neurons expressing the Hb9::GFP reporter from Y-27632-amplified embryoid bodies and cultured them in the presence of mitotic inhibitors to eliminate dividing progenitors. Survival of these purified motor neurons in the absence of any other cell type was strongly dependent on neurotrophic support. GDNF, BDNF and CNTF all showed potent survival effects (EC(50) 1-2 pM). The number of surviving motor neurons was further enhanced in the presence of forskolin and IBMX, agents that increase endogenous cAMP levels. As a demonstration of the ability of the assay to detect novel neurotrophic agents, Y-27632 itself was found to support human motor neuron survival. Thus, purified human stem cell-derived motor neurons show survival requirements similar to those of primary rodent motor neurons and can be used for rigorous cell-based screening.This work was funded by Project A.L.S., P2ALS and NYSTEM grant number CO24415. The work of N.J.L. was supported by the Portuguese Foundation for Science and Technology SFRH/BD/33421/2008 and the Luso-American Development Foundation. B.J.-K. was supported by the National Institute of Neurological Disorders and Stroke (NINDS). L.R. was supported by the Swedish Brain Foundation/Hjarnfonden. The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript
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