21 research outputs found

    Ephrin-B2 Promotes Nociceptive Plasticity and Hyperalgesic Priming Through EphB2-MNK-eIF4E Signaling in Both Mice and Humans

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    Ephrin-B-EphB signaling can promote pain through ligand-receptor interactions between peripheral cells, like immune cells expressing ephrin-Bs, and EphB receptors expressed by DRG neurons. Previous studies have shown increased ephrin-B2 expression in peripheral tissues like synovium of rheumatoid and osteoarthritis patients, indicating the clinical significance of this signaling. The primary goal of this study was to understand how ephrin-B2 acts on mouse and human DRG neurons, which express EphB receptors, to promote pain and nociceptor plasticity. We hypothesized that ephrin-B2 would promote nociceptor plasticity and hyperalgesic priming through MNK-eIF4E signaling, a critical mechanism for nociceptive plasticity induced by growth factors, cytokines and nerve injury. Both male and female mice developed dose-dependent mechanical hypersensitivity in response to ephrin-B2, and both sexes showed hyperalgesic priming when challenged with PGE2 injection either to the paw or the cranial dura. Acute nociceptive behaviors and hyperalgesic priming were blocked in mice lacking MNK1 (Mknk1 knockout mice) and by eFT508, a specific MNK inhibitor. Sensory neuron-specific knockout of EphB2 using Pirt-Cre demonstrated that ephrin-B2 actions require this receptor. In Ca2+-imaging experiments on cultured DRG neurons, ephrin-B2 treatment enhanced Ca2+ transients in response to PGE2 and these effects were absent in DRG neurons from MNK1-/- and EphB2-PirtCre mice. In experiments on human DRG neurons, ephrin-B2 increased eIF4E phosphorylation and enhanced Ca2+ responses to PGE2 treatment, both blocked by eFT508. We conclude that ephrin-B2 acts directly on mouse and human sensory neurons to induce nociceptor plasticity via MNK-eIF4E signaling, offering new insight into how ephrin-B signaling promotes pain

    Teacher Motivation in India

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    This paper is based on a recent study on teacher motivation in India, which is part of an international research project on this topic covering 12 countries in South Asia and Africa. This study is based on review of government data, policy documents and published material on India and interviews with stakeholders in the state of Rajasthan and rapid survey in ten schools of Tonk District of Rajasthan. This report therefore draws upon national trends and explores them in the context of Rajasthan.The key issues pertaining to the motivation of primary school teachers can be summarised as follows: First, the education system has expanded rapidly and enrolment rates have shot up. But growth rate in the number of teachers has not kept pace with the rise in enrolment.Second, the social distance between the teachers and the children is wide in government schools (which cater to the very poor). Third, teachers lack the skills to manage so much diversity in the classroom. Fourth, systemic issues dealing with corruption have vitiated the larger teaching environment in the country. Fifth, teachers’ unions and block and district-level administrators claim they are asked to do a range of non-teaching taskswhich them away from the classroom. Sixth, teacher training has picked up since 1994 with almost all teachers expected to attend a range of training programmes every year. Seventh, teachers and administrators are continuously embroiled in court cases to do with promotions and placements, claiming arrears due to them and disciplinary action-related issues.teacheres, school education, teaching environment, teacher motivation, teacher training, coruption,Rajasthan, Education, Sociology, Psychology

    Position Paper on National Focus Group: Aims of Education

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    For a fairly long time now, we have been engaged in the great task of educating the children of India, an independent nation with a rich variegated history, extraordinarily complex cultural diversity, and commitment to democratic values and general well-being. Given the enormity and importance of this task, it is necessary to create occasions to sit back collectively and ask ourselves, ‘What are we doing in our engagement with this task? Is there a need to ask ourselves afresh some of the basic questions such as what ought to be the purpose of education?’ This paper addresses these and other issues.education, pedagogy, school, pre-school learning, language, environment, knowledge, Education, Sociology

    Genetic evidence of TAP1 gene variant as a susceptibility factor in Indian leprosy patients

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    The heterodimeric transporter associated with antigen processing (TAP) gene loci is known to play a vital role in immune surveillance. We investigated a possible association of gene polymorphisms both in TAP1 and TAP2 in a cohort of clinically classified leprosy patients (n = 222) and in ethnically matched controls (n = 223). The TAP1 and TAP2 genes were genotyped for four single nucleotide polymorphisms TAP1 (rs1057141 Iso333Val and rs1135216 Asp637Gly) and TAP2 (rs2228396 Ala565Thr and rs241447 Ala665Thr) by direct sequencing and ARMS-PCR. The minor allele of TAP1 637G contributes to an increased risk to leprosy compared to controls (OR: 1.68, 95% CI 1.2–2.36, P = 0.0057). An increased risk for the variant minor allele of the TAP1 637G to multibacillary (BL + LL) or paucibacillary (BT + TT) infections was also observed [multibacillary vs. controls (OR: 1.56, 95% CI 1.07–2.28, P = 0.054); paucibacillary vs. controls (OR: 1.92, 95% CI 1.21–3.01, P = 0.013)]. In the dominant model, the genotypes of the TAP1 rs1135216AG + GG additionally contributed to an increased risk. Overall our findings demonstrate that the TAP1 gene variant (rs1135216 Asp637Gly) influences the susceptibility to clinically classified leprosy patients in Indian population

    ephrin-B2 promotes nociceptive plasticity and hyperalgesic priming through EphB2-MNK-eIF4E signaling in both mice and humans

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    Ephrin-B-EphB signaling can promote pain through ligand-receptor interactions between peripheral cells, like immune cells expressing ephrin-Bs, and EphB receptors expressed by DRG neurons. Previous studies have shown increased ephrin-B2 expression in peripheral tissues like synovium of rheumatoid and osteoarthritis patients, indicating the clinical significance of this signaling. The primary goal of this study was to understand how ephrin-B2 acts on mouse and human DRG neurons, which express EphB receptors, to promote pain and nociceptor plasticity. We hypothesized that ephrin-B2 would promote nociceptor plasticity and hyperalgesic priming through MNK-eIF4E signaling, a critical mechanism for nociceptive plasticity induced by growth factors, cytokines and nerve injury. Both male and female mice developed dose-dependent mechanical hypersensitivity in response to ephrin-B2, and both sexes showed hyperalgesic priming when challenged with PGE2 injection either to the paw or the cranial dura. Acute nociceptive behaviors and hyperalgesic priming were blocked in mice lacking MNK1 (Mknk1 knockout mice) and by eFT508, a specific MNK inhibitor. Sensory neuron-specific knockout of EphB2 using Pirt-Cre demonstrated that ephrin-B2 actions require this receptor. In Ca2+-imaging experiments on cultured DRG neurons, ephrin-B2 treatment enhanced Ca2+ transients in response to PGE2 and these effects were absent in DRG neurons from MNK1-/- and EphB2-PirtCre mice. In experiments on human DRG neurons, ephrin-B2 increased eIF4E phosphorylation and enhanced Ca2+ responses to PGE2 treatment, both blocked by eFT508. We conclude that ephrin-B2 acts directly on mouse and human sensory neurons to induce nociceptor plasticity via MNK-eIF4E signaling, offering new insight into how ephrin-B signaling promotes pain
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