106 research outputs found

    The Application of Web 2.0 Tools in University Libraries of India

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    This research study aims to focus towards the application or evaluation of Web 2.0 tools in State University Libraries of India. The present study deals with the extent usage of Web 2.0 in State University Libraries of India.This research used content analysis based on quantitative and qualitative data which is collected by website observation and questionnaire method. Out of 348 Indian State University Libraries 69% of libraries are having official website and 31% of libraries are lacking any dedicated library webpage. It is found that 9.77% of the Indian State University Libraries were using Web 2.0 technologies to provide services to their users. It is found that the highest Web 2.0 application index is in state of Kerala. OPAC 2.0, Mashups, RSS, Social Bookmarking & Tagging, Social Networking Services, Vodcast and Blog are the most widely applied technology and YouTube, Google Docs, Instant Messaging, Wikis are the least used technology amongst respondent libraries

    Analytical evaluation of drug package inserts in India

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    Background: A drug package insert or prescribing information is a document provided along with a prescription medication to provide additional information about that drug. Drug package inserts are approved by the administrative licensing authority. A package insert is intended to provide information for the safe and effective use of the respective drug. Product information provided by pharmaceutical companies has been determined to be far from adequate and not conforming with requirement of Indian regulatory. Hence, it was decided to conduct a study to assess the presentation and completeness of clinically important information provided in the currently available package inserts in India.Methods: Package inserts were provided by five pharmacies on request. The package inserts were collected in 10 weeks’ period and then they were analyzed for presentation and completeness of clinical information according to heading mentioned in Section 6.2 and 6.3 of schedule D of Drug and Cosmetic Rule, 1945. If the information was present under relevant heading, it was scored as one. Otherwise as score of zero was assigned. Total score for each heading was calculated by adding the score from the individual package inserts.Results: 70 package inserts were included in the study. None of the reviewed package inserts contained all the sections as required by the Drugs and Cosmetics Act. Total 15 headings were evaluated under both Section 6.2 and 6.3, highest value for the presence of heading were 12 out of 15 heading evaluated. That shows the best value of compliance was 80%.Conclusion: Accurate drug product information is important for the safe and effective use of medicines. Hence, pharmaceutical companies and regulators should ensure that accurate and up to date product information is provided in the package inserts

    Convergent activation of two-pore channels mediated by the NAADP-binding proteins JPT2 and LSM12

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    The second messenger nicotinic acid adenine dinucleotide phosphate (NAADP) evokes calcium ion (Ca2+) release from endosomes and lysosomes by activating two-pore channels (TPCs) on these organelles. Rather than directly binding to TPCs, NAADP associates with proteins that indirectly confer NAADP sensitivity to the TPC complex. We investigated whether and how the NAADP-binding proteins Jupiter microtubule-associated homolog 2 (JPT2) and like-Sm protein 12 (LSM12) contributed to NAADP-TPC-Ca2+ signaling in human cells. Biochemical and functional analyses revealed that recombinant JPT2 and LSM12 both bound to NAADP with high affinity and that endogenous JPT2 and LSM12 independently associated with TPC1 and TPC2. On the basis of knockout and rescue analyses, both NAADP-binding proteins were required to support NAADP-evoked Ca2+ signaling and contributed to endolysosomal trafficking of pseudotyped coronavirus particles. These data reveal that the NAADP-binding proteins JPT2 and LSM12 convergently regulate NAADP-evoked Ca2+ release and function through TPCs

    Progesterone receptor membrane component 1 facilitates Ca²⁺ signal amplification between endosomes and the endoplasmic reticulum

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    Membrane contact sites (MCSs) between endosomes and the endoplasmic reticulum (ER) are thought to act as specialized trigger zones for Ca2+ signaling, where local Ca2+ released via endolysosomal ion channels is amplified by ER Ca2+-sensitive Ca2+ channels into global Ca2+ signals. Such amplification is integral to the action of the second messenger, nicotinic acid adenine dinucleotide phosphate (NAADP). However, functional regulators of inter-organellar Ca2+ crosstalk between endosomes and the ER remain poorly defined. Here, we identify progesterone receptor membrane component 1 (PGRMC1), an ER transmembrane protein that undergoes a unique heme-dependent dimerization, as an interactor of the endosomal two pore channel, TPC1. NAADP-dependent Ca2+ signals were potentiated by PGRMC1 overexpression through enhanced functional coupling between endosomal and ER Ca2+ stores and inhibited upon PGRMC1 knockdown. Point mutants in PGMRC1 or pharmacological manipulations that reduced its interaction with TPC1 were without effect. PGRMC1 therefore serves as a TPC1 interactor that regulates ER-endosomal coupling with functional implications for cellular Ca2+ dynamics and potentially the distribution of heme

    Convergent activation of Ca2+ permeability in two-pore channel 2 through distinct molecular routes

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    TPC2 is a pathophysiologically relevant lysosomal ion channel that is activated directly by the phosphoinositide PI(3,5)P2 and indirectly by the calcium ion (Ca2+)-mobilizing molecule NAADP through accessory proteins that associate with the channel. TPC2 toggles between PI(3,5)P2-induced, sodium ion (Na+)-selective and NAADP-induced, Ca2+-permeable states in response to these cues. To address the molecular basis of polymodal gating and ion-selectivity switching, we investigated the mechanism by which NAADP and its synthetic functional agonist, TPC2-A1-N, induced Ca2+ release through TPC2 in human cells. Whereas NAADP required the NAADP-binding proteins JPT2 and LSM12 to evoke endogenous calcium ion signals, TPC2-A1-N did not. Residues in TPC2 that bind to PI(3,5)P2 were required for channel activation by NAADP but not for activation by TPC2-A1-N. The cryptic voltage-sensing region of TPC2 was required for the actions of TPC2-A1-N and PI(3,5)P2 but not for those of NAADP. These data mechanistically distinguish natural and synthetic agonist action at TPC2 despite convergent effects on Ca2+ permeability and delineate a route for pharmacologically correcting impaired NAADP-evoked Ca2+ signals

    Two-pore channel-2 and inositol trisphosphate receptors coordinate Ca²⁺ signals between lysosomes and the endoplasmic reticulum

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    Lysosomes and the endoplasmic reticulum (ER) are Ca2+ stores mobilized by the second messengers NAADP and IP3, respectively. Here, we establish Ca2+ signals between the two sources as fundamental building blocks that couple local release to global changes in Ca2+. Cell-wide Ca2+ signals evoked by activation of endogenous NAADP-sensitive channels on lysosomes comprise both local and global components and exhibit a major dependence on ER Ca2+ despite their lysosomal origin. Knockout of ER IP3 receptor channels delays these signals, whereas expression of lysosomal TPC2 channels accelerates them. High-resolution Ca2+ imaging reveals elementary events upon TPC2 opening and signals coupled to IP3 receptors. Biasing TPC2 activation to a Ca2+-permeable state sensitizes local Ca2+ signals to IP3. This increases the potency of a physiological agonist to evoke global Ca2+ signals and activate a downstream target. Our data provide a conceptual framework to understand how Ca2+ release from physically separated stores is coordinated

    Endoplasmic reticulum and lysosomal Ca2+ stores are remodelled in GBA1-linked Parkinson disease patient fibroblasts.

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    Mutations in β-glucocerebrosidase (encoded by GBA1) cause Gaucher disease (GD), a lysosomal storage disorder, and increase the risk of developing Parkinson disease (PD). The pathogenetic relationship between the two disorders is unclear. Here, we characterised Ca2+ release in fibroblasts from type I GD and PD patients together with age-matched, asymptomatic carriers, all with the common N370S mutation in β-glucocerebrosidase. We show that endoplasmic reticulum (ER) Ca2+ release was potentiated in GD and PD patient fibroblasts but not in cells from asymptomatic carriers. ER Ca2+ signalling was also potentiated in fibroblasts from aged healthy subjects relative to younger individuals but not further increased in aged PD patient cells. Chemical or molecular inhibition of β-glucocerebrosidase in fibroblasts and a neuronal cell line did not affect ER Ca2+ signalling suggesting defects are independent of enzymatic activity loss. Conversely, lysosomal Ca2+ store content was reduced in PD fibroblasts and associated with age-dependent alterations in lysosomal morphology. Accelerated remodelling of Ca2+ stores by pathogenic GBA1 mutations may therefore feature in PD

    A Threshold Model for T-Cell Activation in the Era of Checkpoint Blockade Immunotherapy

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    Continued discoveries of negative regulators of inflammatory signaling provide detailed molecular insights into peripheral tolerance and anti-tumor immunity. Accumulating evidence indicates that peripheral tolerance is maintained at multiple levels of immune responses by negative regulators of proinflammatory signaling, soluble anti-inflammatory factors, inhibitory surface receptors & ligands, and regulatory cell subsets. This review provides a global overview of these regulatory machineries that work in concert to maintain peripheral tolerance at cellular and host levels, focusing on the direct and indirect regulation of T cells. The recent success of checkpoint blockade immunotherapy (CBI) has initiated a dramatic shift in the paradigm of cancer treatment. Unprecedented responses to CBI have highlighted the central role of T cells in both anti-tumor immunity and peripheral tolerance and underscored the importance of T cell exhaustion in cancer. We discuss the therapeutic implications of modulating the negative regulators of T cell function for tumor immunotherapy with an emphasis on inhibitory surface receptors & ligands—central players in T cell exhaustion and targets of checkpoint blockade immunotherapies. We then introduce a Threshold Model for Immune Activation—the concept that these regulatory mechanisms contribute to defining a set threshold of immunogenic (proinflammatory) signaling required to elicit an anti-tumor or autoimmune response. We demonstrate the value of the Threshold Model in understanding clinical responses and immune related adverse events in the context of peripheral tolerance, tumor immunity, and the era of Checkpoint Blockade Immunotherapy
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