72 research outputs found

    Long-term cognitive effects of human stem cell transplantation in the irradiated brain

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    PURPOSE: Radiotherapy remains a primary treatment modality for the majority of central nervous system tumors, but frequently leads to debilitating cognitive dysfunction. Given the absence of satisfactory solutions to this serious problem, we have used human stem cell therapies to ameliorate radiation-induced cognitive impairment. Here, past studies have been extended to determine whether engrafted cells provide even longer-term benefits to cognition. MATERIALS AND METHODS: Athymic nude rats were cranially irradiated (10 Gy) and subjected to intrahippocampal transplantation surgery 2 days later. Human embryonic stem cells (hESC) or human neural stem cells (hNSC) were transplanted, and animals were subjected to cognitive testing on a novel place recognition task 8 months later. RESULTS: Grafting of hNSC was found to provide long lasting cognitive benefits over an 8-month post-irradiation interval. At this protracted time, hNSC grafting improved behavioral performance on a novel place recognition task compared to irradiated animals not receiving stem cells. Engrafted hESC previously shown to be beneficial following a similar task, 1 and 4 months after irradiation, were not found to provide cognitive benefits at 8 months. CONCLUSIONS: Our findings suggest that hNSC transplantation promotes the long-term recovery of the irradiated brain, where intrahippocampal stem cell grafting helps to preserve cognitive function

    Immunological characterization and transcription profiling of peripheral blood (PB) monocytes in children with autism spectrum disorders (ASD) and specific polysaccharide antibody deficiency (SPAD): case study

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    <p>Abstract</p> <p>Introduction</p> <p>There exists a small subset of children with autism spectrum disorders (ASD) characterized by fluctuating behavioral symptoms and cognitive skills following immune insults. Some of these children also exhibit specific polysaccharide antibody deficiency (SPAD), resulting in frequent infection caused by encapsulated organisms, and they often require supplemental intravenous immunoglobulin (IVIG) (ASD/SPAD). This study assessed whether these ASD/SPAD children have distinct immunological findings in comparison with ASD/non-SPAD or non-ASD/SPAD children.</p> <p>Case description</p> <p>We describe 8 ASD/SPAD children with worsening behavioral symptoms/cognitive skills that are triggered by immune insults. These ASD/SPAD children exhibited delayed type food allergy (5/8), treatment-resistant seizure disorders (4/8), and chronic gastrointestinal (GI) symptoms (5/8) at high frequencies. Control subjects included ASD children without SPAD (N = 39), normal controls (N = 37), and non-ASD children with SPAD (N = 12).</p> <p>Discussion and Evaluation</p> <p>We assessed their innate and adaptive immune responses, by measuring the production of pro-inflammatory and counter-regulatory cytokines by peripheral blood mononuclear cells (PBMCs) in responses to agonists of toll like receptors (TLR), stimuli of innate immunity, and T cell stimulants. Transcription profiling of PB monocytes was also assessed. ASD/SPAD PBMCs produced less proinflammatory cytokines with agonists of TLR7/8 (IL-6, IL-23), TLR2/6 (IL-6), TLR4 (IL-12p40), and without stimuli (IL-1ß, IL-6, and TNF-α) than normal controls. In addition, cytokine production of ASD/SPAD PBMCs in response to T cell mitogens (IFN-γ, IL-17, and IL-12p40) and candida antigen (Ag) (IL-10, IL-12p40) were less than normal controls. ASD/non-SPAD PBMDs revealed similar results as normal controls, while non-ASD/SPAD PBMCs revealed lower production of IL-6, IL-10 and IL-23 with a TLR4 agonist. Only common features observed between ASD/SPAD and non-ASD/SPAD children is lower IL-10 production in the absence of stimuli. Transcription profiling of PB monocytes revealed over a 2-fold up (830 and 1250) and down (653 and 1235) regulation of genes in ASD/SPAD children, as compared to normal (N = 26) and ASD/non-SPAD (N = 29) controls, respectively. Enriched gene expression of TGFBR (p < 0.005), Notch (p < 0.01), and EGFR1 (p < 0.02) pathways was found in the ASD/SPAD monocytes as compared to ASD/non-SPAD controls.</p> <p>Conclusions</p> <p>The Immunological findings in the ASD/SPAD children who exhibit fluctuating behavioral symptoms and cognitive skills cannot be solely attributed to SPAD. Instead, these findings may be more specific for ASD/SPAD children with the above-described clinical characteristics, indicating a possible role of these immune abnormalities in their neuropsychiatric symptoms.</p

    Antidepressants increase human hippocampal neurogenesis by activating the glucocorticoid receptor

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    Antidepressants increase adult hippocampal neurogenesis in animal models, but the underlying molecular mechanisms are unknown. In this study, we used human hippocampal progenitor cells to investigate the molecular pathways involved in the antidepressant-induced modulation of neurogenesis. Because our previous studies have shown that antidepressants regulate glucocorticoid receptor (GR) function, we specifically tested whether the GR may be involved in the effects of these drugs on neurogenesis. We found that treatment (for 3–10 days) with the antidepressant, sertraline, increased neuronal differentiation via a GR-dependent mechanism. Specifically, sertraline increased both immature, doublecortin (Dcx)-positive neuroblasts (+16%) and mature, microtubulin-associated protein-2 (MAP2)-positive neurons (+26%). This effect was abolished by the GR-antagonist, RU486. Interestingly, progenitor cell proliferation, as investigated by 5′-bromodeoxyuridine (BrdU) incorporation, was only increased when cells were co-treated with sertraline and the GR-agonist, dexamethasone, (+14%) an effect which was also abolished by RU486. Furthermore, the phosphodiesterase type 4 (PDE4)-inhibitor, rolipram, enhanced the effects of sertraline, whereas the protein kinase A (PKA)-inhibitor, H89, suppressed the effects of sertraline. Indeed, sertraline increased GR transactivation, modified GR phosphorylation and increased expression of the GR-regulated cyclin-dependent kinase-2 (CDK2) inhibitors, p27Kip1 and p57Kip2. In conclusion, our data suggest that the antidepressant, sertraline, increases human hippocampal neurogenesis via a GR-dependent mechanism that requires PKA signaling, GR phosphorylation and activation of a specific set of genes. Our data point toward an important role for the GR in the antidepressant-induced modulation of neurogenesis in humans

    Impact of chronic stress protocols in learning and memory in rodents: systematic review and meta-analysis

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    The idea that maladaptive stress impairs cognitive function has been a cornerstone of decades in basic and clinical research. However, disparate findings have reinforced the need to aggregate results from multiple sources in order to confirm the validity of such statement. In this work, a systematic review and meta-analyses were performed to aggregate results from rodent studies investigating the impact of chronic stress on learning and memory. Results obtained from the included studies revealed a significant effect of stress on global cognitive performance. In addition, stressed rodents presented worse consolidation of learned memories, although no significantly differences between groups at the acquisition phase were found. Despite the methodological heterogeneity across studies, these effects were independent of the type of stress, animals' strains or age. However, our findings suggest that stress yields a more detrimental effect on spatial navigation tests' performance. Surprisingly, the vast majority of the selected studies in this field did not report appropriate statistics and were excluded from the quantitative analysis. We have therefore purposed a set of guidelines termed PROBE (Preferred Reporting Orientations for Behavioral Experiments) to promote an adequate reporting of behavioral experiments.This work was funded by the European Commission (FP7) "SwitchBox" (Contract HEALTH-F2-2010-259772) project and co-financed by the Portuguese North Regional Operational Program (ON.2 - O Novo Norte) under the National Strategic Reference Framework (QREN), through the European Regional Development Fund (FEDER), and by Fundacao Calouste Gulbenkian (Portugal) (Contract grant number: P-139977; project "Better mental health during ageing based on temporal prediction of individual brain ageing trajectories (TEMPO)"). PSM is supported by an FCT fellowship grant, from the PhD-iHES program, with the reference PDE/BDE/113601/2015.info:eu-repo/semantics/publishedVersio

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    Not AvailableIncreasing resource degradation (soil) and resource scarcity (water) in Indo Gangetic Planes (IGP) had popularized the concept of conservation agriculture (CA). CA practices can alter the soil hydraulic properties by improving soil physical environment and hence water productivity (WP). Since CA practices are highly site - specific in nature, its worthiness under different cropping systems, soil types and agro - climatic zones must be studied. In the context of above - mentioned scenario of crop management practices, Hydrus - 2D model was used to evaluate most suitable CA - based practice for north western (NW) IGP to understand the process of water transport. The experiment had 3 - tillage and crop establishment practices [ZT - zero tillage; PB - permanent raised bed and CT - conventional tillage] in main plot and 4 - cropping systems [MWMb - maize - wheat - mungbean; MCS - maize - chickpea - Sesbania; MMuMb - maize - mustard - mungbean and MMS - maize - maize - Sesbania] in sub - plot. The validation of Hydrus - 2D showed that nRMSE was observed between 0.19 - 0.25 and R2 value between 0.80 - 0.87 at P<0.01. This indicates model is performing efficiently. The R2 value (0.87) was observed highest and RMSE (0.03) and nRMSE (0.15) was observed least in the CA - based PB plots. CA - based plots had 23%–37% less evaporation than CT plots. Cumulative root water uptake (CRWU) under PB was 11% and 15% lower, whereas CRWU under ZT was 20% and 30% higher than CT plots in 2012 and 2013, respectively. Cumulative deep drainage (CDD) in 2013 in PB was higher by 3.64 and 5.88 cm than ZT and CT, respectively. With 10 - cm higher rainfall during 2013, variability in the soil water content (SWC) was increased by 22% in CT and 2% in ZT plots. PB had 14–35% and 30–36% higher water productivity than ZT and CT plots, respectively. Radiation use efficiency (RUE) for dry - matter was observed higher under CA based plots. However, RUE for grain yield was observed similar among CA and CT plots during 2012, but in 2013, ZT outperformed than CT plots. The outcome of this study is, the higher rainfall during 2013 mainly contributed to more CDD. Highly variable SWC was observed in the CT plots. With lesser deep drainage in ZT, root water uptake (RWU) was higher and WP was lower, whereas PB plots had comparatively less - moist soil profile and per unit of RWU + evaporation, a proportionately higher dry - matter was produced. In a well - drained soil profile of PB plots frequent and light irrigation may be advocated, whereas in ZT with better profile storage and lesser variability of SWC during both the year irrigation may be required less frequently. Therefore, adoption of CA - based practices leads to higher crop productivity and resource use efficiency, because of favorable soil hydrological propertywith less fluctuation in soil water content in maize under diversified cropping systems of IGP of south Asia.Not Availabl
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