370 research outputs found

    Bottom-Up versus Top-Down Induction of Sleep by Zolpidem Acting on Histaminergic and Neocortex Neurons

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    Zolpidem, a GABAA receptor-positive modulator, is the gold-standard drug for treating insomnia. Zolpidem prolongs IPSCs to decrease sleep latency and increase sleep time, effects that depend on α2 and/or α3 subunit-containing receptors. Compared with natural NREM sleep, zolpidem also decreases the EEG power, an effect that depends on α1 subunit-containing receptors, and which may make zolpidem-induced sleep less optimal. In this paper, we investigate whether zolpidem needs to potentiate only particular GABAergic pathways to induce sleep without reducing EEG power. Mice with a knock-in F77I mutation in the GABAA receptor γ2 subunit gene are zolpidem-insensitive. Using these mice, GABAA receptors in the frontal motor neocortex and hypothalamic (tuberomammillary nucleus) histaminergic-neurons of γ2I77 mice were made selectively sensitive to zolpidem by genetically swapping the γ2I77 subunits with γ2F77 subunits. When histamine neurons were made selectively zolpidem-sensitive, systemic administration of zolpidem shortened sleep latency and increased sleep time. But in contrast to the effect of zolpidem on wild-type mice, the power in the EEG spectra of NREM sleep was not decreased, suggesting that these EEG power-reducing effects of zolpidem do not depend on reduced histamine release. Selective potentiation of GABAA receptors in the frontal cortex by systemic zolpidem administration also reduced sleep latency, but less so than for histamine neurons. These results could help with the design of new sedatives that induce a more natural sleep

    Brand awareness and its influence on repeat customers in the airline industry

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    India's aviation industry is seeing growth, and the country is host to several domestic airline firms.In India, the domestic aviation industry is predominantly composed of private airlines, accounting for over 75% of the market, making it one of the aviation markets with the highest growth rates globally. Currently, there are 454 functioning airports in the country, out of which 16 are international airports. The aviation sector is projected to have a resurgence with an anticipated compound annual growth rate (CAGR) of 18% in 2011. The Civil Aviation Ministry's current predictions indicate that increasing traffic movement and revenues-which climbed by about US$ 21.4 million in 2009-will enable India's Airports Authority to create higher margins in 2009-2010. Acknowledging and. Recognizing and delivering high-quality service begins with knowing exactly what clients want. Service quality is one of the finest measures for assessing the opinions and expectations of clients. Customer performance within an organization determines customers satisfaction with services. Passenger happiness affects customer sovereignty. It is possible for customers to be really satisfied and still not be loyal, or vice versa. Companies need to have a deeper understanding of the relation between online behaviour and contentment in order to divide internet marketing tactics between programs that promote behavioural intention and happiness. The findings will benefit airline managers by enabling them to monitor and improve the quality of their workforce, improve customer service, and increase passenger satisfaction. In India, buying airline tickets again and again is rather usual, particularly for business or frequent visitors. Numerous domestic airlines in India have frequent flyer and loyalty programmes as a means of encouraging consumers to keep using them when making travel reservations. Furthermore, a lot of Indian travellers buy their flights using online travel agents (OTAs), which make it simple for consumers to compare options and costs across several airlines. To entice users to make additional reservations, these OTAs frequently provide cashback or discount incentives for recurring bookings. Furthermore, a lot of Indian airlines entice customers to buy tickets with them again and again by providing a range of promotional deals, discounts, and cashback incentives at different periods of the year. In general, Indians frequently buy plane tickets again and are influenced by loyalty programs, frequent flyer programs, discounts, cashback offers, and the ease of booking through online travel agencies

    High-throughput single cell arrays as a novel tool in biopreservation

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    Microwell array cytometry is a novel high-throughput experimental technique that makes it possible to correlate pre-stress cell phenotypes and post-stress outcomes with single cell resolution. Because the cells are seeded in a high density grid of cell-sized microwells, thousands of individual cells can be tracked and imaged through manipulations as extreme as freezing or drying. Unlike flow cytometry, measurements can be made at multiple time points for the same set of cells. Unlike conventional image cytometry, image analysis is greatly simplified by arranging the cells in a spatially defined pattern and physically separating them from one another. To demonstrate the utility of microwell array cytometry in the field of biopreservation, we have used it to investigate the role of mitochondrial membrane potential in the cryopreservation of primary hepatocytes. Even with optimized cryopreservation protocols, the stress of freezing almost always leads to dysfunction or death in part of the cell population. To a large extent, cell fate is dominated by the stochastic nature of ice crystal nucleation, membrane rupture, and other biophysical processes, but natural variation in the initial cell population almost certainly plays an important and under-studied role. Understanding why some cells in a population are more likely to survive preservation will be invaluable for the development of new approaches to improve preservation yields. For this paper, primary hepatocytes were seeded in microwell array devices, imaged using the mitochondrial dyes Rh123 or JC-1, cryopreserved for up to a week, rapidly thawed, and checked for viability after a short recovery period. Cells with a high mitochondrial membrane potential before freezing were significantly less likely to survive the freezing process, though the difference in short term viability was fairly small. The results demonstrate that intrinsic cell factors do play an important role in cryopreservation survival, even in the short term where extrinsic biophysical factors would be expected to dominate. We believe that microwell array cytometry will be an important tool for a wide range of studies in biopreservation and stress biology. © 2009 Elsevier Inc. All rights reserved

    Differential effect of sleep deprivation on place cell representations, sleep architecture, and memory in young and old mice

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    Poor sleep quality is associated with age-related cognitive decline, and whether reversal of these alterations is possible is unknown. In this study, we report how sleep deprivation (SD) affects hippocampal representations, sleep patterns, and memory in young and old mice. After training in a hippocampus-dependent object-place recognition (OPR) task, control animals sleep ad libitum, although experimental animals undergo 5 h of SD, followed by recovery sleep. Young controls and old SD mice exhibit successful OPR memory, whereas young SD and old control mice are impaired. Successful performance is associated with two cellular phenotypes: (1) context cells, which remain stable throughout training and testing, and (2) object configuration cells, which remap when objects are introduced to the context and during testing. Additionally, effective memory correlates with spindle counts during non-rapid eye movement (NREM)/rapid eye movement (REM) sigma transitions. These results suggest SD may serve to ameliorate age-related memory deficits and allow hippocampal representations to adapt to changing environments

    Extracellular Matrix Aggregates from Differentiating Embryoid Bodies as a Scaffold to Support ESC Proliferation and Differentiation

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    Embryonic stem cells (ESCs) have emerged as potential cell sources for tissue engineering and regeneration owing to its virtually unlimited replicative capacity and the potential to differentiate into a variety of cell types. Current differentiation strategies primarily involve various growth factor/inducer/repressor concoctions with less emphasis on the substrate. Developing biomaterials to promote stem cell proliferation and differentiation could aid in the realization of this goal. Extracellular matrix (ECM) components are important physiological regulators, and can provide cues to direct ESC expansion and differentiation. ECM undergoes constant remodeling with surrounding cells to accommodate specific developmental event. In this study, using ESC derived aggregates called embryoid bodies (EB) as a model, we characterized the biological nature of ECM in EB after exposure to different treatments: spontaneously differentiated and retinoic acid treated (denoted as SPT and RA, respectively). Next, we extracted this treatment-specific ECM by detergent decellularization methods (Triton X-100, DOC and SDS are compared). The resulting EB ECM scaffolds were seeded with undifferentiated ESCs using a novel cell seeding strategy, and the behavior of ESCs was studied. Our results showed that the optimized protocol efficiently removes cells while retaining crucial ECM and biochemical components. Decellularized ECM from SPT EB gave rise to a more favorable microenvironment for promoting ESC attachment, proliferation, and early differentiation, compared to native EB and decellularized ECM from RA EB. These findings suggest that various treatment conditions allow the formulation of unique ESC-ECM derived scaffolds to enhance ESC bioactivities, including proliferation and differentiation for tissue regeneration applications. © 2013 Goh et al

    Group problem management plus (PM+) to decrease psychological distress among Syrian refugees in Turkey: a pilot randomised controlled trial

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    BACKGROUND: Syrian refugees resettled in Turkey show a high prevalence of symptoms of mental disorders. Problem Management Plus (PM+) is an effective psychological intervention delivered by non-specialist health care providers which has shown to decrease psychological distress among people exposed to adversity. In this single-blind pilot randomised controlled trial, we examined the methodological trial procedures of Group PM+ (gPM+) among Syrian refugees with psychological distress in Istanbul, Turkey, and assessed feasibility, acceptability, perceived impact and the potential cost-effectiveness of the intervention. METHODS: Refugees with psychological distress (Kessler Psychological Distress Scale, K10 > 15) and impaired psychosocial functioning (World Health Organization Disability Assessment Schedule, WHODAS 2.0 > 16) were recruited from the community and randomised to either gPM+ and enhanced care as usual (E-CAU) (n = 24) or E-CAU only (n = 22). gPM+ comprised of five weekly group sessions with eight to ten participants per group. Acceptability and feasibility of the intervention were assessed through semi-structured interviews. The primary outcome at 3-month follow-up was symptoms of depression and anxiety (Hopkins Symptoms Checklist-25). Psychosocial functioning (WHODAS 2.0), symptoms of posttraumatic stress disorder and self-identified problems (Psychological Outcomes Profiles, PSYCHLOPS) were included as secondary outcomes. A modified version of the Client Service Receipt Inventory was used to document changes in the costs of health service utilisation as well as productivity losses. RESULTS: There were no barriers experienced in recruiting study participants and in randomising them into the respective study arms. Retention in gPM+ was high (75%). Qualitative analyses of the interviews with the participants showed that Syrian refugees had a positive view on the content, implementation and format of gPM+. No adverse events were reported during the implementation. The study was not powered to detect an effect. No significant difference between gPM+ and E-CAU group on primary and secondary outcome measures, or in economic impacts were found. CONCLUSIONS: gPM+ delivered by non-specialist peer providers seemed to be an acceptable, feasible and safe intervention for Syrian refugees in Turkey with elevated levels of psychological distress. This pilot RCT sets the stage for a fully powered RCT. TRIAL REGISTRATION: ClinicalTrials.gov Identifier NCT03567083 ; date: 25/06/2018

    Effectiveness and cost-effectiveness of self-help plus (sh+) for preventing mental disorders in refugees and asylum seekers in Europe and Turkey: Study protocols for two randomised controlled trials

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    Introduction This article describes two randomised controlled trials that will evaluate the effectiveness and cost-effectiveness of Self-Help Plus (SH+), a group self-help intervention developed by the WHO to reduce distress. In these trials SH+ is being tested as a preventative intervention to lower the incidence of mental disorders in asylum seekers and refugees with psychological distress resettled in Europe and Turkey. Methods and analysis Two prospective, multicentre, randomised, rater-blinded, parallel-group studies will follow participants over a period of 12 months. One trial will be conducted in Europe and one in Turkey. In each trial, 600 asylum seekers and refugees screening positive on the General Health Questionnaire (≥3), but without a formal diagnosis of any mental disorders according to the Mini International Neuropsychiatric Interview, will be randomly allocated to SH+or to enhanced treatment-as-usual. The primary outcome will be a lower incidence of mental disorders at 6 month follow-up. Secondary outcomes will include the evaluation of psychological symptoms, functioning, well-being, treatment acceptability and indicators of intervention cost-effectiveness. Ethics and dissemination The two trials received ethical clearance from the local Ethics Committees of the participating sites (seven sites), as well as from the WHO Ethics Committee. All participants will provide informed consent before screening and before study inclusion (a two-step procedure). The results of the trials will be disseminated in agreement with a dissemination plan that includes publication(s) in peer-reviewed journals and presentations at relevant national and international conferences and meetings. Trials registration numbers NCT03571347, NCT03587896

    An assessment of serum leptin levels in patients with chronic viral hepatitis: a prospective study

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    <p>Abstract</p> <p>Background</p> <p>The role of leptin in the course of liver disease due to chronic viral hepatitis (CVH) remains controversial. Our aims were to investigate the relationship between serum leptin concentrations and the severity of liver disease in a cohort of subjects with HBeAg negative chronic hepatitis B (CHB) and C (CHC) and to analyze the effect of body composition, the leptin system and insulin resistance together with viral factors on virologic response to antiviral treatment.</p> <p>Methods</p> <p>We studied 50 (36 men) consecutive patients suffering from biopsy-proven CVH due to HBV (n = 25) or HCV (n = 25) infection. Thirty-two (17 men) healthy volunteers served as controls. Levels of serum leptin and insulin were determined by immunoassays at baseline and at the end of the treatment.</p> <p>Results</p> <p>A significant association between serum leptin levels and the stage of hepatic fibrosis was noted; patients with cirrhosis presented higher serum leptin levels compared to those with lower fibrosis stage [CHB patients (17436 pg/ml vs 6028.5 pg/ml, p = 0.03), CHC patients (18014 pg/ml vs 4385 pg/ml, p = 0.05]. An inverse correlation between lower leptin levels and response to lamivudine monotherapy was noted in patients with CHB; those with a virologic response presented lower serum leptin levels (5334 vs 13111.5 pg/ml; p-value = 0.003) than non-responders. In genotype 1 CHC patients, insulin resistance played a significant role in the response to antiviral therapy.</p> <p>Conclusion</p> <p>Our data clearly suggest that cirrhosis due to CHB or CHC is associated with higher leptin levels. Increased serum leptin levels represent a negative prognostic factor for response to lamivudine monotherapy in patients with CHB. In CHC patients insulin resistance strongly influences the response to antiviral treatment in patients infected with genotype 1.</p

    Rapid production of human liver scaffolds for functional tissue engineering by high shear stress oscillation-decellularization

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    The development of human liver scaffolds retaining their 3-dimensional structure and extra-cellular matrix (ECM) composition is essential for the advancement of liver tissue engineering. We report the design and validation of a new methodology for the rapid and accurate production of human acellular liver tissue cubes (ALTCs) using normal liver tissue unsuitable for transplantation. The application of high shear stress is a key methodological determinant accelerating the process of tissue decellularization while maintaining ECM protein composition, 3D-architecture and physico-chemical properties of the native tissue. ALTCs were engineered with human parenchymal and non-parenchymal liver cell lines (HepG2 and LX2 cells, respectively), human umbilical vein endothelial cells (HUVEC), as well as primary human hepatocytes and hepatic stellate cells. Both parenchymal and non-parenchymal liver cells grown in ALTCs exhibited markedly different gene expression when compared to standard 2D cell cultures. Remarkably, HUVEC cells naturally migrated in the ECM scaffold and spontaneously repopulated the lining of decellularized vessels. The metabolic function and protein synthesis of engineered liver scaffolds with human primary hepatocytes reseeded under dynamic conditions were maintained. These results provide a solid basis for the establishment of effective protocols aimed at recreating human liver tissue in vitro
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