53 research outputs found
DYRK1A and Activity-Dependent Neuroprotective Protein Comparative Diagnosis Interest in Cerebrospinal Fluid and Plasma in the Context of Alzheimer-Related Cognitive Impairment in Down Syndrome Patients
Down syndrome (DS) is a complex genetic condition due to an additional copy of human chromosome 21, which results in the deregulation of many genes. In addition to the intellectual disability associated with DS, adults with DS also have an ultrahigh risk of developing early onset Alzheimer's disease dementia. DYRK1A, a proline-directed serine/threonine kinase, whose gene is located on chromosome 21, has recently emerged as a promising plasma biomarker in patients with sporadic Alzheimer's disease (AD). The protein DYRK1A is truncated in symptomatic AD, the increased truncated form being associated with a decrease in the level of full-length form. Activity-dependent neuroprotective protein (ADNP), a key protein for the brain development, has been demonstrated to be a useful marker for symptomatic AD and disease progression. In this study, we evaluated DYRK1A and ADNP in CSF and plasma of adults with DS and explored the relationship between these proteins. We used mice models to evaluate the effect of DYRK1A overexpression on ADNP levels and then performed a dual-center cross-sectional human study in adults with DS in Barcelona (Spain) and Paris (France). Both cohorts included adults with DS at different stages of the continuum of AD: asymptomatic AD (aDS), prodromal AD (pDS), and AD dementia (dDS). Non-trisomic controls and patients with sporadic AD dementia were included for comparison. Full-form levels of DYRK1A were decreased in plasma and CSF in adults with DS and symptomatic AD (pDS and dDS) compared to aDS, and in patients with sporadic AD compared to controls. On the contrary, the truncated form of DYRK1A was found to increase both in CSF and plasma in adults with DS and symptomatic AD and in patients with sporadic AD with respect to aDS and controls. ADNP levels showed a more complex structure. ADNP levels increased in aDS groups vs. controls, in agreement with the increase in levels found in the brains of mice overexpressing DYRK1A. However, symptomatic individuals had lower levels than aDS individuals. Our results show that the comparison between full-length and truncated-form levels of DYRK1A coupled with ADNP levels could be used in trials targeting pathophysiological mechanisms of dementia in individuals with DS
Radiation-induced Bystander Effect (RIBE) alters mitochondrial metabolism using a human rectal cancer ex vivo explant model
Locally advanced rectal cancer is treated with neoadjuvant-chemoradiotherapy, however only 22% of patients achieve a complete response. Resistance mechanisms are poorly understood. Radiation-induced Bystander Effect (RIBE) describes the effect of radiation on neighbouring unirradiated cells. We investigated the effects of ex vivo RIBEinduction from normal and rectal cancer tissue on bystander cell metabolism, mitochondrial function and metabolomic profiling. We correlated bystander events to patient clinical characteristics. Ex vivo RIBE-induction caused metabolic alterations in bystander cells, specifically reductions in OXPHOS following RIBE-induction in normal (p = 0.01) and cancer tissue (p = 0.03) and reduced glycolysis following RIBE-induction in cancer tissue (p = 0.01). Visceral fat area correlated with glycolysis (p = 0.02) and ATP production (p = 0.03) following exposure of cells to TCM from irradiated cancer biopsies. Leucine levels were reduced in the irradiated cancer compared to the irradiated normal secretome (p = 0.04). ROS levels were higher in cells exposed to the cancer compared to the normal secretome (p = 0.04). RIBE-induction ex vivo causes alterations in the metabolome in normal and malignant rectal tissue along with metabolic alterations in bystander cellular metabolism. This may offer greater understanding of the effects of RIBE on metabolism, mitochondrial function and the secreted metabolome
Nutrimetabolomics: An Integrative Action for Metabolomic Analyses in Human Nutritional Studies
The life sciences are currently being transformed by an unprecedented wave of developments in molecular analysis, which include important advances in instrumental analysis as well as biocomputing. In light of the central role played by metabolism in nutrition, metabolomics is rapidly being established as a key analytical tool in human nutritional studies. Consequently, an increasing number of nutritionists integrate metabolomics into their study designs. Within this dynamic landscape, the potential of nutritional metabolomics (nutrimetabolomics) to be translated into a science, which can impact on health policies, still needs to be realized. A key element to reach this goal is the ability of the research community to join, to collectively make the best use of the potential offered by nutritional metabolomics. This article, therefore, provides a methodological description of nutritional metabolomics that reflects on the state‐of‐the‐art techniques used in the laboratories of the Food Biomarker Alliance (funded by the European Joint Programming Initiative "A Healthy Diet for a Healthy Life" (JPI HDHL)) as well as points of reflections to harmonize this field. It is not intended to be exhaustive but rather to present a pragmatic guidance on metabolomic methodologies, providing readers with useful "tips and tricks" along the analytical workflow
Accelerated turnover of taste bud cells in mice deficient for the cyclin-dependent kinase inhibitor p27Kip1
Background: Mammalian taste buds contain several specialized cell types that coordinately respond to tastants and communicate with sensory nerves. While it has long been appreciated that these cells undergo continual turnover, little is known concerning how adequate numbers of cells are generated and maintained. The cyclin-dependent kinase inhibitor p27Kip1 has been shown to influence cell number in several developing tissues, by coordinating cell cycle exit during cell differentiation. Here, we investigated its involvement in the control of taste cell replacement by examining adult mice with targeted ablation of the p27Kip1 gene.Results: Histological and morphometric analyses of fungiform and circumvallate taste buds reveal no structural differences between wild-type and p27Kip1-null mice. However, when examined in functional assays, mutants show substantial proliferative changes. In BrdU incorporation experiments, more S-phase-labeled precursors appear within circumvallate taste buds at 1 day post-injection, the earliest time point examined. After 1 week, twice as many labeled intragemmal cells are present, but numbers return to wild-type levels by 2 weeks. Mutant taste buds also contain more TUNEL-labeled cells and 50% more apoptotic bodies than wild-type controls. In normal mice, p27 Kip1 is evident in a subset of receptor and presynaptic taste cells beginning about 3 days post-injection, correlating with the onset of taste cell maturation. Loss of gene function, however, does not alter the proportions of distinct immunohistochemically-identified cell types.Conclusions: p27Kip1 participates in taste cell replacement by regulating the number of precursor cells available for entry into taste buds. This is consistent with a role for the protein in timing cell cycle withdrawal in progenitor cells. The equivalence of mutant and wild-type taste buds with regard to cell number, cell types and general structure contrasts with the hyperplasia and tissue disruption seen in certain developing p27Kip1-null sensory organs, and may reflect a compensatory capability inherent in the regenerative taste system
Veille technologique
SIGLEAvailable from INIST (FR), Document Supply Service, under shelf-number : TM 662(1); TM 662(2) / INIST-CNRS - Institut de l'Information Scientifique et TechniqueFRFranc
Increasing autonomy in publically owned services.
PURPOSE: The purpose of this paper is to explore government efforts to enhance the autonomy of community health services (CHS) in England through the creation of Foundation Trusts status. It considers why some CHS elected to become nascent Community Foundation Trusts (CFTs) while others had not and what advantages they thought increased levels of autonomy offered. DESIGN/METHODOLOGY/APPROACH: Data are drawn from the evaluation of the Department of Health's CFT pilot programme. Participants were purposively selected from pilot sites, as well as from comparator non-pilot organisations. A total of 44 staff from 14 organisations were interviewed. FINDINGS: The data reveals that regardless of the different pathways that organisations were on, they all shared the same goal, a desire for greater autonomy, but specifically within the NHS. Additionally, irrespective of their organisational form most organisations were considering an almost identical set of initiatives as a means to improve service delivery and productivity. RESEARCH LIMITATIONS/IMPLICATIONS: Despite the expectations of policy makers no CFTs were established during the course of the study, so it is not possible to find out what the effect of such changes were. Nevertheless, the authors were able to investigate the attitudes of all the providers of CHS to the plans to increase their managerial autonomy, whether simply by separating from PCTs or by becoming CFTs. ORIGINALITY/VALUE: As no CFTs have yet been formed, this study provides the only evidence to date about increasing autonomy for CHS in England
Organisational turbulence for community health
A policy of separating all NHS community health services (CHS) from commissioning organisations (then primary care trusts) was launched in 2008. Some CHS were to become foundation trusts (FTs—in this case, CFTs). FTs are NHS organizations with greater autonomy from the centre, able to retain any surpluses, which are thought to be able to improve efficiency and quality of services. Those CHS not destined to become CFTs were to be merged with NHS mental health and/or hospital services, or to be ‘spun out’ of the NHS to become independent not-for-profit organisations. We observed the changes made during the preparatory period, and the expectations of the effects of FT status of the managers of CHS and their NHS commissioners, together with those CHS not on the CFT pathway. We found that all CHS in the study were becoming more business-like, and starting to improve service delivery and productivity, irrespective of whether they were destined to become CFTs. Although increased autonomy was appreciated, most CHS wanted to stay within the NHS. Some managers were concerned they would lose their autonomy when merging with other NHS services. The changes and uncertainty about organisational policy for CHS have been disruptive and time consuming
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