Liver hyperplasia and paradoxical regulation of glycogen metabolism and glucose-sensitive gene expression in GLUT2-null hepatocytes. Further evidence for the existence of a membrane-based glucose release pathway.

We investigated the impact of GLUT2 gene inactivation on the regulation of hepatic glucose metabolism during the fed to fast transition. In control and GLUT2-null mice, fasting was accompanied by a approximately 10-fold increase in plasma glucagon to insulin ratio, a similar activation of liver glycogen phosphorylase and inhibition of glycogen synthase and the same elevation in phosphoenolpyruvate carboxykinase and glucose-6-phosphatase mRNAs. In GLUT2-null mice, mobilization of glycogen stores was, however, strongly impaired. This was correlated with glucose-6-phosphate (G6P) levels, which remained at the fed values, indicating an important allosteric stimulation of glycogen synthase by G6P. These G6P levels were also accompanied by a paradoxical elevation of the mRNAs for L-pyruvate kinase. Re-expression of GLUT2 in liver corrected the abnormal regulation of glycogen and L-pyruvate kinase gene expression. Interestingly, GLUT2-null livers were hyperplasic, as revealed by a 40% increase in liver mass and 30% increase in liver DNA content. Together, these data indicate that in the absence of GLUT2, the G6P levels cannot decrease during a fasting period. This may be due to neosynthesized glucose entering the cytosol, being unable to diffuse into the extracellular space, and being phosphorylated back to G6P. Because hepatic glucose production is nevertheless quantitatively normal, glucose produced in the endoplasmic reticulum may also be exported out of the cell through an alternative, membrane traffic-based pathway, as previously reported (Guillam, M.-T., Burcelin, R., and Thorens, B. (1998) Proc. Natl. Acad. Sci. U. S. A. 95, 12317-12321). Therefore, in fasting, GLUT2 is not required for quantitative normal glucose output but is necessary to equilibrate cytosolic glucose with the extracellular space. In the absence of this equilibration, the control of hepatic glucose metabolism by G6P is dominant over that by plasma hormone concentrations.

Cross-talk between glutamate and potassium regulation at the astrocyte membrane

Astrocytes play a central role in the brain by regulating glutamate and extracellular potassium concentrations ([K+]0), both released by neurons into the extracellular space during neuronal activity. Glutamate uptake is driven by the inwardly directed sodium gradient across the astrocyte membrane and involves the influx of three sodium ions and one proton and the efflux of one K+ ion per glutamate molecule. The glutamate transport induced rise in intracellular sodium stimulates the Na+/K+-ATPase which leads to significant energetic costs in astrocytes. To evaluate how these two fundamental functions of astrocytes, namely glutamate transport and K+ buffering, which are directly associated with neuronal activity, coexist and if they influence each other, in this thesis work we examined different cellular parameters of astrocytes. We therefore investigated the impact of altered [K+]0 on glutamate transporter activity. To assess this question we measured intracellular sodium fluctuations in mouse primary cultured astrocytes using dynamic fluorescence imaging. We found that glutamate uptake was tightly modulated both in amplitude and kinetics by [K+]0. Elevated [K+]0 strongly decreased glutamate transporter activity, with significant consequences on the cells energy metabolism. To ultimately evaluate potential effects of [K+]0 and glutamate on the astrocyte mitochondrial energy production we extended these studies by investigating their impact on the cytosolic and mitochondrial pH. We found that both [K+],, and glutamate strongly influenced cytosolic and mitochondrial pH, but in opposite directions. The effect of a simultaneous application of K+ and glutamate, however, did not fit with the arithmetical sum of each individual effects, suggesting that an additional non¬linear process is involved. We also investigated the impact of [K+]0 and glutamate transport, respectively, on intracellular potassium concentrations ([K+]0 in cultured astrocytes by characterizing and applying a newly developed Insensitive fluorescent dye. We observed that [K+]i followed [K+]0 changes in a nearly proportional way and that glutamate superfusion caused a reversible, glutamate-concentration dependent drop of [K+],, Our study shows the powerful influence of [K+]u on glutamate capture. These findings have strong implications for our understanding of the tightly regulated interplay between astrocytes and neurons in situations where [K+]0 undergoes large activity-dependent fluctuations. However, depending on the extent of K+ versus glutamate extracellular rise, energy metabolism in astrocytes will be differently regulated. Moreover, the novel insights obtained during this thesis work help understanding some of the underlying processes that prevail in certain pathologies of central nervous system, such as epilepsy and stroke. These results will possibly provide a basis for the development of novel therapeutic strategies. -- Les astrocytes jouent un rôle central dans le cerveau en régulant les concentrations de potassium (K+) et de glutamate, qui sont relâchés par les neurones dans l'espace extracellulaire lorsque ceux- ci sont actifs. La capture par les astrocytes du glutamate est un processus secondairement actif qui implique l'influx d'ions sodium (Na+) et d'un proton, ainsi que l'efflux d'ions K+, ce processus entraîne un coût métabolique important. Nous avons évalué comment ces fonctions fondamentales des astrocytes, la régulation du glutamate et du K+ extracellulaire, qui sont directement associés à l'activité neuronale, coexistent et si elles interagissent, en examinant différents paramètres cellulaires. Dans ce projet de thèse nous avons évalué l'impact des modifications de la concentration de potassium extracellulaire ([K+],,) sur le transport du glutamate. Nous avons mesuré le transport du glutamate par le biais des fluctuations internes de Na+ grâce à un colorant fluorescent en utilisant de l'imagerie à fluorescence dynamique sur des cultures primaires d'astrocytes. Nous avons trouvé que la capture du glutamate était étroitement régulée par [K+]0 aussi bien dans son amplitude que dans sa cinétique. Par la suite, nous avons porté notre attention sur l'impact de [K+]0 et du glutamate sur le pH cytosolique et mitochondrial de l'astrocyte dans le but, in fine, d'évaluer les effets potentiels sur la production d'énergie par la mitochondrie. Nous avons trouvé qu'autant le K+ que le glutamate, de manière individuelle, influençaient fortement le pH, cependant dans des directions opposées. Leurs effets individuels, ne peuvent toutefois pas être additionnés ce qui suggère qu'un processus additionnel non-linéaire est impliqué. En appliquant une nouvelle approche pour suivre et quantifier la concentration intracellulaire de potassium ([K+]0 par imagerie à fluorescence, nous avons observé que [K+]i suivait les changements de [K+]0 de manière quasiment proportionnelle et que la superfusion de glutamate induisait un décroissement rapide et réversible de [K+]i, qui dépend de la concentration de glutamate. Notre étude démontre l'influence de [K+]0 sur la capture du glutamate. Ces résultats permettent d'améliorer notre compréhension de l'interaction entre astrocytes et neurones dans des situations où [K+]0 fluctue en fonction de l'activité neuronale. Cependant, en fonction de l'importance de l'augmentation extracellulaire du K+ versus le glutamate, le métabolisme énergétique des astrocytes va être régulé de manière différente. De plus, les informations nouvelles que nous avons obtenues durant ce travail de thèse nous aident à comprendre quelques- uns des processus sous-jacents qui prévalent dans certaines pathologies du système nerveux central, comme par exemple l'épilepsie ou l'accident vasculaire cérébral. Ces informations pourront être importantes à intégrer dans la cadre du développement de nouvelles stratégies thérapeutiques.

Direct Payments Policy and Practice Review Report (PDF 243 KB)

Direct Payments are cash payments made in lieu of social service provisions, to individuals who have been assessed as needing services. Direct Payments increase choice and promote independence. They provide for a more flexible response than may otherwise be possible for the service user and carer. They allow individuals to decide when and in what form services are provided and who provides them, who comes into their home and who becomes involved in very personal aspects of their lives. Direct Payments put real power into the hands of service users and carers, and allow them to take control over their lives. Access to Direct Payments as a means of delivering social services in Northern Ireland has been available since 1996 under the Personal Social Services (Direct Payments) (Northern Ireland) Order 1996. Since then take up of Direct Payments has been limited in number with the majority being accessed in the physical disability programme. åÊ

Women's Mental Health: Promoting a Gendered Approach to Policy and Service Provision

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SLÃÅN: Smoking Patterns in Ireland: Implications for policy and services

SLÃÅN: Smoking Patterns in Ireland: Implications for policy and services Click here to download PDF 1.1mb

National Policy and Strategy for the Provision of Neuro-Rehabilitation Services in Ireland 2011 - 2015

National Policy and Strategy for the Provision of Neuro-Rehabilitation Services in Ireland 2011 – 2015 Click here to download PDF 1.51MB

Expression and developmental regulation of Ehk-1, a neuronal Elk-like receptor tyrosine kinase in brain.

Protein tyrosine kinases are pivotal in central nervous tissue development and maintenance. Here we focus on the expression of Ehk-1, a novel Elk-related receptor tyrosine kinase. Ehk-1 gene expression is observed in the developing and adult central nervous system and is highly regulated throughout development at both the messenger RNA and protein levels. Three messenger RNA transcripts of 8.5, 5.9 and 5.1 kb are detectable in the rat brain and a variety of splice possibilities have been identified. However, a major protein species of around M(r) 120,000 predominates throughout development. Ehk-1 messenger RNA and protein levels are highest in the first postnatal week. By in situ messenger RNA hybridization the gene is expressed by all neurons of the adult brain, but mostly in the hippocampus, cerebral cortex and large neurons of the deep cerebellar nuclei, as well as the Purkinje and granular cells of the cerebellum. At earlier stages of development, transcripts are most prominent in the periventricular germinal layers of the brain. Immunohistochemistry reveals a pronounced membrane associated protein expression in immature neurons. In the adult animal, peak reactivity was found in the neuropil with sparing of most perikarya. The spatial and temporal pattern of ehk-1 gene expression suggests a role in both the development and maintenance of differentiated neurons of the central nervous system.

Characterization of the hcnABC gene cluster encoding hydrogen cyanide synthase and anaerobic regulation by ANR in the strictly aerobic biocontrol agent Pseudomonas fluorescens CHA0.

The secondary metabolite hydrogen cyanide (HCN) is produced by Pseudomonas fluorescens from glycine, essentially under microaerophilic conditions. The genetic basis of HCN synthesis in P. fluorescens CHA0 was investigated. The contiguous structural genes hcnABC encoding HCN synthase were expressed from the T7 promoter in Escherichia coli, resulting in HCN production in this bacterium. Analysis of the nucleotide sequence of the hcnABC genes showed that each HCN synthase subunit was similar to known enzymes involved in hydrogen transfer, i.e., to formate dehydrogenase (for HcnA) or amino acid oxidases (for HcnB and HcnC). These similarities and the presence of flavin adenine dinucleotide- or NAD(P)-binding motifs in HcnB and HcnC suggest that HCN synthase may act as a dehydrogenase in the reaction leading from glycine to HCN and CO2. The hcnA promoter was mapped by primer extension; the -40 sequence (TTGGC ... ATCAA) resembled the consensus FNR (fumarate and nitrate reductase regulator) binding sequence (TTGAT ... ATCAA). The gene encoding the FNR-like protein ANR (anaerobic regulator) was cloned from P. fluorescens CHA0 and sequenced. ANR of strain CHA0 was most similar to ANR of P. aeruginosa and CydR of Azotobacter vinelandii. An anr mutant of P. fluorescens (CHA21) produced little HCN and was unable to express an hcnA-lacZ translational fusion, whereas in wild-type strain CHA0, microaerophilic conditions strongly favored the expression of the hcnA-lacZ fusion. Mutant CHA21 as well as an hcn deletion mutant were impaired in their capacity to suppress black root rot of tobacco, a disease caused by Thielaviopsis basicola, under gnotobiotic conditions. This effect was most pronounced in water-saturated artificial soil, where the anr mutant had lost about 30% of disease suppression ability, compared with wild-type strain CHA0. These results show that the anaerobic regulator ANR is required for cyanide synthesis in the strictly aerobic strain CHA0 and suggest that ANR-mediated cyanogenesis contributes to the suppression of black root rot.

Public Policy and Ageing in Northern Ireland: Identifying Levers for Change

Public Policy and Ageing in Northern Ireland: Identifying Levers for Change Judith Cross, Policy Officer with the Centre for Ageing Research Development in Ireland (CARDI)��������Introduction Identifying a broad range of key public policy initiatives as they relate to age can facilitate discussion and create new knowledge within and across government to maximise the opportunities afforded by an ageing population. This article looks at how examining the current public policy frameworks in Northern Ireland can present opportunities for those working in this field for the benefit of older people. Good policy formulation needs to be evidence-based, flexible, innovative and look beyond institutional boundaries. Bringing together architects and occupational therapists, for example, has the potential to create better and more effective ways relevant to health, housing, social services and government departments. Traditional assumptions of social policy towards older people have tended to be medically focused with an emphasis on care and dependency. This in turn has consequences for the design and delivery of services for older people. It is important that these assumptions are challenged as changes in thinking and attitudes can lead to a redefinition of ageing, resulting in policies and practices that benefit older people now and in the future. Older people, their voices and experiences, need to be central to these developments. The Centre for Ageing Research and Development in Ireland The Centre for Ageing Research and Development in Ireland (CARDI) (1) is a not for profit organisation developed by leaders from the ageing field across Ireland (North and South) including age sector focused researchers and academics, statutory and voluntary, and is co-chaired by Professor Robert Stout and Professor Davis Coakley. CARDI has been established to provide a mechanism for greater collaboration among age researchers, for wider dissemination of ageing research information and to advance a research agenda relevant to the needs of older people in Ireland, North and South. Operating at a strategic level and in an advisory capacity, CARDI�۪s work focuses on promoting research co-operation across sectors and disciplines and concentrates on influencing the strategic direction of research into older people and ageing in Ireland. It has been strategically positioned around the following four areas: Identifying and establishing ageing research priorities relevant to policy and practice in Ireland, North and South;Promoting greater collaboration and co-operation on ageing research in order to build an ageing research community in Ireland, North and South;Stimulating research in priority areas that can inform policy and practice relating to ageing and older people in Ireland, North and South;Communicating strategic research issues on ageing to raise the profile of ageing research in Ireland, North and South, and its role in informing policy and practice. Context of Ageing in Ireland Ireland �۪s population is ageing. One million people aged 60 and over now live on the island of Ireland. By 2031, it is expected that Northern Ireland�۪s percentage of older people will increase to 28% and the Republic of Ireland�۪s to 23%. The largest increase will be in the older old; the number aged 80+ is expected to triple by the same date. However while life expectancy has increased, it is not clear that life without disability and ill health has increased to the same extent. A growing number of older people may face the combined effects of a decline in physical and mental function, isolation and poverty. Policymakers, service providers and older people alike recognise the need to create a high quality of life for our ageing population. This challenge can be meet by addressing the problems relating to healthy ageing, reducing inequalities in later life and creating services that are shaped by, and appropriate for, older people. Devolution and Structures of Government in Northern Ireland The Agreement (2) reached in the Multi-Party Negotiations in Belfast 1998 established the Northern Ireland Assembly which has full legislative authority for all transferred matters. The majority of social and economic public policy such as; agriculture, arts, education, health, environment and planning is determined by the Northern Ireland Assembly at Stormont. There are 11 Government Departments covering the main areas of responsibility with 108 elected Members of the Legislative Assembly (MLA�۪s). The powers of the Northern Ireland Assembly do not cover ��� reserved�۪ matters or ��� excepted�۪ matters . These are the responsibility of Westminster and include issues such as, tax, social security, policing, justice, defence, immigration and foreign affairs. Northern Ireland has 18 elected Members of Parliament (MP�۪s) to the House of Commons. Public Policy Context in Northern Ireland The economic, social and political consequence of an ageing population is a challenge for policy makers across government. Considering the complex and diverse causal factors that contribute to ageing in Northern Ireland, there are a number of areas of government policy at regional, national and international levels that are likely to impact in this area. International The Madrid International Plan of Action on Ageing (3) and the Research Agenda on Ageing for the 21st Century (4) provide important mechanisms for furthering research into ageing. The United Kingdom has signed up to these. The Madrid International Plan of Action on Ageing commits member states to a systematic review of the Plan of Action through Regional Implementation Strategies. The United Kingdom�۪s Regional Implementation Strategy covers Northern Ireland. National At National level, pension and social security are high on the agenda. The Pensions Act (5) became law in 2007 and links pensions increases with earnings as opposed to prices from 2012. Additional credits for people raising children and caring for older people to boost their pensions were introduced. Some protections are included for those who lost occupational pensions as a result of underfunded schemes being wound up before April 2005. In relation to State Pensions and benefits, this Act will bring changes to state pensions in future. The Act now places the Pension Credit element which is up-rated in line with or above earnings, on a permanent, statutory footing. Regional At regional level there are a number of age related public policy initiatives that have the potential to impact positively on the lives of older people in Northern Ireland. Some are specific to ageing such as the Ageing in an Inclusive Society (6) and others by their nature are cross-cutting such as Lifetime Opportunities: Governments Anti-Poverty Strategy for Northern Ireland (7). The main public policy framework in Northern Ireland is the Programme for Government: Building a Better Future, 2008-2011(PfG) (8) . The PfG, is the overarching high level policy framework for Northern Ireland and provides useful principles for ageing research and public policy in Northern Ireland. The PfG vision is to build a peaceful, fair and prosperous society in Northern Ireland, with respect for the rule of law. A number of Public Service Agreements (PSA) aligned to the PfG confirm key actions that will be taken to support the priorities that the Government aim to achieve over the next three years. For example objective 2 of PSA 7: Making Peoples�۪ Lives Better: Drive a programme across Government to reduce poverty and address inequality and disadvantage, refers to taking forward strategic action to promote social inclusion for older people; and to deliver a strong independent voice for older people. The Office of the First Minister and deputy First Minister (OFMDFM) have recently appointed an Interim Older People�۪s Advocate, Dame Joan Harbison to provide a focus for older peoples issues across Government. Ageing in an Inclusive Society is the cross-departmental strategy for older people in Northern Ireland and was launched in March 2005. It sets out the approach to be taken across Government to promote and support the inclusion of older people. The vision coupled with six strategic objectives form the basis of the action plans accompanying the strategy. The vision is: ���To ensure that age related policies and practices create an enabling environment, which offers everyone the opportunity to make informed choices so that they may pursue healthy, active and positive ageing.�۝ (Ageing in an Inclusive Society, Office of the First Minister and Deputy First Minister, 2005) Action planning and maintaining momentum across government in relation to this strategy has proved to be slower than anticipated. It is proposed to refresh this Strategy in line with Opportunity Age ��� meeting the challenges of ageing in the 21st Century (9). There are a number of policy levers elsewhere which can also be used to promote the positive aspects of an ageing society. The Investing for Health (10) and A Healthier Future:A 20 Year Vision for Health and Well-being in Northern Ireland (11), seek to ensure that the overall vision for health and wellbeing is achievable and provides a useful framework for ageing policy and research in the health area. These health initiatives have the potential to positively impact on the quality of life of older people and provide a useful framework for improving current policy and practice. In addition to public policy initiatives, the anti-discrimination frameworks in terms of employment in Northern Ireland cover age as well as a range of other grounds. Goods facilitates and services are currently excluded from the Employment Equality (age) Regulations (NI) 2006 (12). Supplementing the anti-discrimination measures, Section 75 of the Northern Ireland Act 1998 (13), unique to Northern Ireland, places a statutory obligation on public authorities in fulfilling their functions to promote equality of opportunity across nine grounds, one of which is age(14). This positive duty has the potential to make a real difference to the lives of older people in Northern Ireland. Those affected by policy decisions must be consulted and their interests taken into account. This provides an opportunity for older people and their representatives to participate in public policy-making, right from the start of the process. Policy and Research Interface ���Ageing research is vital as decisions in relation to policy and practice and resource allocation will be made on the best available information�۝. (CARDI�۪s Strategic Plan 2008-2011) As outlined earlier, CARDI has been established to bridge the gap to ensure that research reaches those involved in making policy decisions. CARDI is stimulating the ageing research agenda in Ireland through a specific research fund that has a policy and practice focus. My work is presently focusing on helping to build a greater awareness of the key policy levers and providing opportunities for those within research and policy to develop closer links. The development of this shared understanding by establishing these links between researchers and policy makers is seen as the best predictor for research utilization. It is important to acknowledge and recognise that researchers and policy makers operate in different institutional, political and cultural contexts. Research however needs to ���resonate�۪ with the contextual factors in which policy makers operate. Conclusions Those working within the public policy field recognise all too often that the development of government policies and initiatives in respect of age does not guarantee that they will result in changes in actual provision of services, despite Government recommendations and commitments. The identification of public policy initiatives as they relate to age has the potential to highlight persistent and entrenched difficulties that social policy has previously failed to address. Furthermore, the identification of these difficulties can maximise the opportunities for progressing these across government. A focus on developing effective and meaningful targets to ensure measurable outcomes in public policy for older people can assist in this. Access to sound, credible and up-to-date evidence will be vital in this respect. As well as a commitment to working across departmental boundaries to effect change. Further details: If you would like to discuss this paper or for further information about CARDI please contact: Judith Cross, Policy Officer, Centre for Ageing Research and Development in Ireland CARDI). t: +44 (0) 28 9069 0066; m: +353 (0) 867 904 171; e: judith@cardi.ie ; or visit our website at: www.cardi.ie References 1) Centre for Ageing Research and Development in Ireland (2008) Strategic Plan 2008-2011. Belfast. CARDI 2) The Agreement: Agreement Reached in the Multi-Party Negotiations. Belfast 1998 3) Madrid International Plan of Action on Ageing. http://www.un.org/ageing/ 4) UN Programme on Ageing (2007) Research Agenda on Ageing for the 21st Century: 2007 Update. New York. New York. UN Programme on Ageing and the International Association of Gerontology and Geriatrics. 5) The Pensions Act 2007 Chapter 22 6) Office of the First Minister and deputy First Minister (2005). Ageing in an Inclusive Society. Belfast. OFMDFM Central Anti-Poverty Unit. 7) Office of the First Minister and deputy First Minister (2005). Lifetime Opportunities: Government�۪s Anti-Poverty and Social Inclusion Strategy for Northern Ireland. Belfast. OFMDFM Central Anti-Poverty Unit. 8) Northern Ireland Executive (2008) Building a Better Future: Programme for Government 2008-2011. Belfast. OFMDFM Economic Policy Unit. 9) Department for Work and Pensions, (2005) Opportunity Age: Meeting the Challenges of Ageing in the 21 st Century. London. DWP. 10) Department of Health, Social Services and Public Safety (DHSS&PS) (2002) Investing for Health. Belfast. DHSS&PS. 11) Department of Health, Social Services and Public Safety (DHSS&PS) (2005) A Healthier Future:A 20 Year Vision for Health and Well-being in Northern Ireland Belfast. DHSS&PS. �� 12) The Employment Equality (Age) Regulations (Northern Ireland) 2006 SR2006 No.261 13) The Northern Ireland Act 1998, Part VII, S75 14) The nine grounds covered under S75 of the Northern Ireland Act are: gender, religion, race, sexual orientation, those with dependents, disability, political opinion, marital status and age.