137 resultados para co-limitation
Resumo:
There is much evidence that alcohol use disorders (AUD) often co-occur with posttraumatic stress disorders (PTSD), and that the comorbid condition is associated with a more severe clinical profile than that of PTSD without AUD. However, little is known about the role of childhood adversities as specific risk factors for the development of AUD in individuals presenting with PTSD. The aim of the study was to explore whether specific stressors from the spectrum of trauma and childhood adversities contribute to the development of AUD among subjects with PTSD. From a large community sample, of N=140 individuals with PTSD, N=24 (17.14%) received an additional diagnosis of AUD with an onset after the onset of PTSD. Those with comorbid PTSD/AUD and those with PTSD only were compared regarding type and features of their trauma, childhood adversities and psychiatric comorbidity. Compared to PTSD alone, PTSD/AUD was associated with higher levels of stress in terms of childhood adversities; in particular, sexual abuse below the age of 16, but also with having been brought up in a foster home. PTSD/AUD was also associated with an earlier age of adverse events. Treatment of AUD should include standardized assessments of trauma, especially of trauma experienced during childhood.
Resumo:
OBJECTIVE: The aim of the study was to compare subjects dually diagnosed with posttraumatic stress disorder (PTSD) and alcohol use disorder (AUD) to those with only one or none of these conditions regarding helpseeking needs and behaviors. METHOD: Data from a large community sample (N=3694) were used to assess the associations among lifetime PTSD and AUD, other psychiatric disorders, clinical characteristics and lifetime helpseeking behaviors derived from a semi-structured interview. RESULTS: Comorbid individuals had more severe clinical profiles and were more impaired than individuals with either PTSD or AUD alone or those with no/other psychiatric conditions. However, they did not differ in overall helpseeking behavior from any other group. Those with comorbid PTSD/AUD were even less likely than the other groups to seek help for depression and anxiety disorders through specific treatment facilities or the use of prescribed psychotropic drugs. CONCLUSIONS: Despite a greater need for treatment the comorbid group did not seek more help than the others. Their lower use of prescribed drugs supports the self-medication hypothesis, suggesting that those individuals relieve their symptoms through higher alcohol use instead. Our findings underline the need for health care facilities to encourage helpseeking behavior in the aftermath of stressful life events.
Resumo:
Previous research has shown that different foods are stereotypically associated with gender and that eating in a role-congruent way fulfills an impression management function. On the other hand, other studies revealed that adapting one's food consumption to that of the co-eaters is a means to gain social approval as well. In the present study, we bridge these two distinct lines of research by studying what happens when the two norms (conforming to the gender-based stereotype and imitating the co-eater) conflict, that is with opposite-sex co-eaters. Results indicated that the tendency to match the co-eaters' supposed consumption generally appeared over and above one's gender-congruent choice. In addition, as expected, gender differences also emerged: while men were always willing to adapt to the co-eaters, women's intention to eat the feminine food was independent from the co-eaters' gender.
Resumo:
There is much evidence that alcohol use disorders (AUD) often co-occur with posttraumatic stress disorders (PTSD), and that the comorbid condition is associated with a more severe clinical profile than that of PTSD without AUD. However, little is known about the role of childhood adversities as specific risk factors for the development of AUD in individuals presenting with PTSD. The aim of the study was to explore whether specific stressors from the spectrum of trauma and childhood adversities contribute to the development of AUD among subjects with PTSD. From a large community sample, of N=140 individuals with PTSD, N=24 (17.14%) received an additional diagnosis of AUD with an onset after the onset of PTSD. Those with comorbid PTSD/AUD and those with PTSD only were compared regarding type and features of their trauma, childhood adversities and psychiatric comorbidity. Compared to PTSD alone, PTSD/AUD was associated with higher levels of stress in terms of childhood adversities; in particular, sexual abuse below the age of 16, but also with having been brought up in a foster home. PTSD/AUD was also associated with an earlier age of adverse events. Treatment of AUD should include standardized assessments of trauma, especially of trauma experienced during childhood.
Resumo:
Cette thèse analyse la co-évolution de deux secteurs dans la politique de la santé: santé publique (public health) et soins aux malades (health care). En d'autres termes, la relation entre les dimensions curative et préventive de la politique de la santé et leur développement dans la durée. Une telle recherche est nécessaire car les problèmes de la santé sont complexes et ont besoin de solutions coordonnées. De plus, les dépenses de la santé ont augmenté sans arrt durant les dernières décennies. Un moyen de réduire une future augmentation des dépenses pourrait consister en davantage d'investissement dans des mesures préventives. En relation avec cette idée, ma recherche analyse les politiques de la santé publique et les soins aux malades de cinq pays: Allemagne, Angleterre, Australie, Etats-Unis et Suisse. En m'appuyant sur la littérature secondaire, des statistiques descriptives et des entretiens avec des experts et des politiciens, j'analyse la relation entre les deux secteurs depuis la fin du dix-neuvième siècle. En particulier, je me focalise sur la relation des deux champs sur trois niveaux: institutions, acteurs et politiques. Mes résultats montrent les similitudes et les différences d'évolution entre les cinq pays. D'un c^oté, lorsque la profession médicale est politiquement active et que le pays consiste en une fédération centralisée ou en un gouvernement unitaire, les deux secteurs sont intégrés au niveau institutionnel, ralliant les professions et groupes d'intérêt des deux secteurs la cause commune dans une activité politique. Par contre, dans tous les pays, les deux secteurs ont co-évolué vers une complémentarité malgré de la politisation des professions et la centralisation du gouvernement. Ces résultats sont intéressants pour la science politique en général car ils soulignent l'importance des professions pour le développement institutionnel et proposent un cadre pour l'analyse de la co-évolution des politiques publiques en général. -- This Ph.D. thesis analyzes the co-evolution of the health care and the public health sectors. In other words, the relation between preventive and curative health policy and its evolution over time. Such research is necessary, because current health problems are complex and might need coordinated solutions. What is more, health expenditures have increased continuously in the last decades. One way to slow down further increase in health spending could be to invest more in preventative health policies. Therefore, I am connecting individual health care and public health into a common analysis, taking Australia, Germany, Switzerland, the UK and the U.S. as examples. Based on secondary literature, descriptive statistics and interviews with experts and policymakers, I am analyzing how the two sectors' relations co-evolved between the late nineteenth and the early twenty-first century. Specifically, I am researching how health care and public health were related on the levels of institutions, actors and policies. My results show that there are differences and similarities in the co-evolution of policy sectors between these countries. On the one hand, when the medical profession was politically active and the country a centralized federation or a unitary state, there was institutional integration and common political advocacy of the sectors' interest groups and professions. On the other hand, in all countries, both sectors co-evolved towards complementarity, irrespectively of the politicization of professions and centralization of government. These findings are interesting for the political science literature at large, because they underline the importance of professions for institutional development and propose an analytical framework for analyzing the co-evolution of policy sectors in general.
Resumo:
Cells couple growth with division and regulate size in response to nutrient availability. In rod-shaped fission yeast, cell-size control occurs at mitotic commitment. An important regulator is the DYRK-family kinase Pom1, which forms gradients from cell poles and inhibits the mitotic activator Cdr2, itself localized at the medial cortex. Where and when Pom1 modulates Cdr2 activity is unclear as Pom1 medial cortical levels remain constant during cell elongation. Here we show that Pom1 re-localizes to cell sides upon environmental glucose limitation, where it strongly delays mitosis. This re-localization is caused by severe microtubule destabilization upon glucose starvation, with microtubules undergoing catastrophe and depositing the Pom1 gradient nucleator Tea4 at cell sides. Microtubule destabilization requires PKA/Pka1 activity, which negatively regulates the microtubule rescue factor CLASP/Cls1/Peg1, reducing CLASP's ability to stabilize microtubules. Thus, PKA signalling tunes CLASP's activity to promote Pom1 cell side localization and buffer cell size upon glucose starvation.
Resumo:
Cells couple their growth and division rate in response to nutrient availability to maintain a constant size. This co-ordination happens either at the G1-S or the G2-M transition of the cell cycle. In the rod-shaped fission yeast, size regulation happens at the G2-M transition prior to mitotic commitment. Recent studies have focused on the role of the DYRK-family protein kinase Pom1, which forms gradients emanating from cell poles and inhibits the mitotic activator kinase Cdr2, present at the cell middle. Pom1 was proposed to inhibit Cdr2 until cells reached a critical size before division. However when and where Pom1 inhibits Cdr2 is not clear as medial Pom1 levels do not change during cell elongation. Here I show that Pom1 gradients are susceptible to environmental changes in glucose. Specifically, upon glucose limitation, Pom1 re-localizes from the poles to the cell sides where it delays mitosis through regulating Cdr2. This re-localization occurs due to microtubule de- stabilization and lateral catastrophes leading to transient deposition of the Pom1 gradient nucleator Tea4 along the cell cortex. As Tea4 localization to cell sides is sufficient to recruit Pom1, this explains the mechanism of Pom1 re-localization. Microtubule destabilization and consequently Tea4 and Pom1 spread depends on the activity of the cAMP-dependent Protein Kinase A (PKA/Pka1), as pka1 mutant cells have stable microtubules and retain polar Tea4 and Pom1 under limited glucose. PKA signaling negatively regulates the microtubule rescue factor CLASP/Cls1, thus reducing its ability to stabilize microtubules. Thus PKA signaling tunes CLASP activity to promote microtubule de-stabilization and Pom1 re-localization upon glucose limitation. I show that the side-localized Pom1 delays mitosis and balances the role of the mitosis promoting, mitogen-associated protein kinase (MAPK) protein Sty1. Thus Pom1 re-localization may serve to buffer cell size upon glucose limitation. -- Afin de maintenir une taille constante, les cellules régulent leur croissance ainsi que leur taux de division selon les nutriments disponibles dans le milieu. Dans la levure fissipare, cette régulation de la taille précède l'engagement mitotique et se fait à la transition entre les phases G2 à M du cycle cellulaire. Des études récentes se sont focalisées sur le rôle de la protéine Pom1, membre de la famille des DYRK kinase. Celle-ci forme un gradient provenant des pôles de la cellule et inhibe l'activateur mitotique Cdr2 présent au centre de la cellule. Le model propose que Pom1 inhibe Cdr2 jusqu'à atteindre une taille critique avant la division. Cependant quand et à quel endroit dans la cellulle Pom1 inhibe Cdr2 n'était pas clair car les niveaux médians de Pom1 ne changent pas au cours de la l'élongation des cellules. Dans cette étude, je montre que les gradients de Pom1 sont sensibles aux changements environnementaux du taux de glucose. Plus spécifiquement, en conditions limitantes de glucose, Pom1 se relocalise des pôles de la cellule pour se distribuer sur les côtés de celle-ci. Par conséquent, un délai d'entrée en mitose est observé dû à l'inhibition Cdr2 par Pom1. Cette délocalisation est due à la déstabilisation des microtubules qui va conduire à une déposition transitoire de Tea4, le nucléateur du gradient de Pom1, tout au long du cortex de la cellule. Comme la localisation de Tea4 sur les côtés de la cellule est suffisante pour recruter la protéine Pom1, ceci explique le mécanisme de relocalisation de celle-ci. La déstabilisation des microtubules et par conséquent la diffusion de Tea4 et Pom1 dépendent de l'activité de la protéine kinase A dépendante de l'AMP cyclique (PKA/Pka1). En absence de pka1, la stabilité des microtubules n'est pas affectée ce qui permet la rétention de Tea4 et Pom1 aux pôles de la cellule même en conditions limitantes de glucose. La signalisation via PKA régule négativement le facteur de sauvetage des microtubules CLASP/Cls1 et permet donc de réduire sa fonction de déstabilisation des microtubules. Ainsi la signalisation via PKA affine l'activité des CLASP pour promouvoir la déstabilisation des microtubules et la relocalisation de Pom1 en conditions limitantes de glucose. Je montre que la localisation sur les côtés retarde l'entrée en mitose et compense l'action de la protéine Sty1, connue pour être une MAPK qui induit l'entrée en mitose. Ainsi, la relocalisation de Pom1 pourrait servir à tamponner la taille de la cellule en condition limitantes de glucose. -- Various cell types in the environment such as bacterial, plant or animal cells have a distinct cellular size. Maintaining a constant cell size is important for fitness in unicellular organisms and for diverse functions in multicellular organisms. Cells regulate their size by coordinating their growth rate to their division rate. This coupling is important otherwise cells would get progressively smaller or larger after each successive cell cycle. In their natural environment cells may face fluctuations in the available nutrient supply. Thus cells have to coordinate their division rate to the variable growth rates shown under different nutrient conditions. During my PhD, I worked with a single-celled rod shaped yeast called the fission yeast. These cells are longer when the nutrient supply is abundant and shorter when the nutrient supply is scarce. A protein that senses changes in the external carbon source (glucose) is called Protein Kinase A (PKA). The rod shape of fission yeast cells is maintained thanks to a structural backbone called the cytoskeleton. One of the components of this backbone is called microtubules, which are small tube like structures spanning the length of the cell. They transport a protein called Tea4, which in turn is important for the proper localization of another protein Pom1 to the cell ends. Pom1 helps to maintain proper shape and size of these rod shaped yeast cells. My thesis work showed that upon reduction in the external nutrient (glucose) levels, microtubules become less stable and show an alteration in their organization. A significant percentage of the microtubules contact the side of the cell instead of touching only the cell tip. This leads to the spreading of the protein Pom1 away from the tips all around the cell periphery. This helps fission yeast cells to maintain the proper size required under these conditions of limited glucose supply. I further showed that the protein PKA regulates microtubule stability and organization and thus Pom1 spreading and maintenance of proper cell size. Thus my work led to the discovery of a novel pathway by which fission yeast cells maintain their size under limited supply of glucose. -- Divers types cellulaires dans l'environnement tels que les bactéries, les plantes ou les cellules animales ont une taille précise. Le maintien d'une taille cellulaire constante est importante pour le fitness des organismes unicellulaire ainsi que pour multiples fonctions dans les organismes multicellulaires. Les cellules régulent leur taille en coordonnant le taux de croissance avec le taux de division. Ce couplage est essentiel sinon les cellules deviendraient progressivement plus petites ou plus grandes après chaque cycle cellulaire. Dans leur habitat naturels les cellules peuvent faire face a des fluctuations dans le taux de nutriment disponible. Les cellules doivent donc coordonner leur taux de division aux taux variables de croissances perçus dans les différentes conditions nutritionnels. Pendant ma thèse, j'ai travaillée sur une levure unicellulaire, en forme de bâtonnet, nommé levure fissipare ou levure de fission. La taille de ces cellules est plus grande quand le taux de nutriments est grand et plus courte quand celui-ci est plus faible. Une protéine qui perçoit les changements dans le taux externe de la source de carbone (glucose) est nommée PKA pour protéine kinase A. La forme en bâtonnet de la cellule est due aux caractères structuraux du cytosquelette. Une composante importante de ce cytosquelette sont les microtubules, dont la structures ressemble à des petit tubes qui vont d'un bout à l'autre de la cellule. Ces microtubules transportent une protéine importante nommée Tea4 qui à leur tour importante pour la bonne localisation d'une autre protéine Pom1 aux extrémités de la cellule. La protéine Pom1 aide à maintenir la taille appropriée des levures fissipares. Mon travail de thèse a montré qu'en présence de taux faible de nutriments (glucose) les microtubules deviennent de moins en moins stables et montrent une désorganisation globale. Un pourcentage significatif des microtubules touche les côtés de la cellule aux lieu d'atteindre uniquement les extrémités. Ceci a pour conséquence une diffusion de Pom1 tout au long du cortex de la cellule. Ceci aide les levures fissipares à maintenir la taille appropriée pendant ce stress nutritionnel. De plus, je montre que PKA régule la stabilité et l'organisation des microtubules et par conséquent la diffusion de Pom1 et le maintien d'une taille constante. En conclusion, mon travail a conduit à la découverte d'un nouveau mécanisme par lequel la levure fissipare maintient sa taille dans des conditions limitantes en glucose.
Resumo:
The production of beneficial public goods is common in the microbial world, and so is cheating - the exploitation of public goods by nonproducing mutants. Here, we examine co-evolutionary dynamics between cooperators and cheats and ask whether cooperators can evolve strategies to reduce the burden of exploitation, and whether cheats in turn can improve their exploitation abilities. We evolved cooperators of the bacterium Pseudomonas aeruginosa, producing the shareable iron-scavenging siderophore pyoverdine, together with cheats, defective in pyoverdine production but proficient in uptake. We found that cooperators managed to co-exist with cheats in 56% of all replicates over approximately 150 generations of experimental evolution. Growth and competition assays revealed that co-existence was fostered by a combination of general adaptions to the media and specific adaptions to the co-evolving opponent. Phenotypic screening and whole-genome resequencing of evolved clones confirmed this pattern, and suggest that cooperators became less exploitable by cheats because they significantly reduced their pyoverdine investment. Cheats, meanwhile, improved exploitation efficiency through mutations blocking the costly pyoverdine-signalling pathway. Moreover, cooperators and cheats evolved reduced motility, a pattern that likely represents adaptation to laboratory conditions, but at the same time also affects social interactions by reducing strain mixing and pyoverdine sharing. Overall, we observed parallel evolution, where co-existence of cooperators and cheats was enabled by a combination of adaptations to the abiotic and social environment and their interactions.
Resumo:
Adjuvants enhance immunogenicity of vaccines through either targeted antigen delivery or stimulation of immune receptors. Three cationic nanoparticle formulations were evaluated for their potential as carriers for a DNA vaccine, and muramyl dipeptide (MDP) as immunostimulatory agent, to induce and increase immunogenicity of Mycobacterium tuberculosis antigen encoding plasmid DNA (pDNA). The formulations included (1) trimethyl chitosan (TMC) nanoparticles, (2) a squalene-in-water nanoemulsion, and (3) a mineral oil-in-water nanoemulsion. The adjuvant effect of the pDNA-nanocomplexes was evaluated by serum antibody analysis in immunized mice. All three carriers display a strong adjuvant effect, however, only TMC nanoparticles were capable to bias immune responses towards Th1. pDNA naturally contains immunostimulatory unmethylated CpG motifs that are recognized by Toll-like receptor 9 (TLR-9). In mechanistic in vitro studies, activation of TLR-9 and the ability to enhance immunogenicity by simultaneously targeting TLR-9 and NOD-like receptor 2 (NLR-2) was determined by proinflammatory cytokine release in RAW264.7 macrophages. pDNA in combination with MDP was shown to significantly increase proinflammatory cytokine release in a synergistic manner, dependent on NLR-2 activation. In summary, novel pDNA-Ag85A loaded nanoparticle formulations, which induce antigen specific immune responses in mice were developed, taking advantage of the synergistic combinations of TLR and NLR agonists to increase the adjuvanticity of the carriers used.
Resumo:
Hypothesis: The quality of care for chronic patients depends on the collaborative skills of the healthcare providers.1,2 The literature lacks reports of the use of simulation to teach collaborative skills in non-acute care settings. We posit that simulation offers benefits for supporting the development of collaborative practice in non-acute settings. We explored the benefits and challenges of using an Interprofessional Team - Objective Structured Clinical Examination (IT-OSCE) as a formative assessment tool. IT-OSCE is an intervention which involves an interprofessional team of trainees interacting with a simulated patient (SP) enabling them to practice collaborative skills in non-acute care settings.5 A simulated patient are people trained to portray patients in a simulated scenario for educational purposes.6,7 Since interprofessional education (IPE) ultimately aims to provide collaborative patient-centered care.8,9 We sought to promote patient-centeredness in the learning process. Methods: The IT-OSCE was conducted with four trios of students from different professions. The debriefing was co-facilitated by the SP with a faculty. The participants were final-year students in nursing, physiotherapy and medicine. Our research question focused on the introduction of co-facilitated (SP and faculty) debriefing after an IT-OSCE: 1) What are the benefits and challenges of involving the SP during the debriefing? and 2) To evaluate the IT-OSCE, an exploratory case study was used to provide fine grained data 10, 11. Three focus groups were conducted - two with students (n=6; n=5), one with SPs (n=3) and one with faculty (n=4). Audiotapes were transcribed for thematic analysis performed by three researchers, who found a consensus on the final set of themes. Results: The thematic analysis showed little differentiation between SPs, student and faculty perspectives. The analysis of transcripts revealed more particularly, that the SP's co-facilitation during the debriefing of an IT-OSCE proved to be feasible. It was appreciated by all the participants and appeared to value and to promote patient-centeredness in the learning process. The main challenge consisted in SPs feedback, more particularly in how they could report accurate observations to a students' group rather than individual students. Conclusion: In conclusion, SP methodology using an IT-OSCE seems to be a useful and promising way to train collaborative skills, aligning IPE, simulation-based team training in a non-acute care setting and patient-centeredness. We acknowledge the limitations of the study, especially the small sample and consider the exploration of SP-based IPE in non-acute care settings as strength. Future studies could consider the preparation of SPs and faculty as co-facilitators. References: 1. Borrill CS, Carletta J, Carter AJ, et al. The effectiveness of health care teams in the National Health Service. Aston centre for Health Service Organisational Research. 2001. 2. Reeves S, Lewin S, Espin S, Zwarenstein M. Interprofessional teamwork for health and social care. Oxford: Wiley-Blackwell; 2010. 3. Issenberg S, McGaghie WC, Petrusa ER, Gordon DL, Scalese RJ. Features and uses of high-fidelity medical simulations that lead to effective learning - a BEME systematic review. Medical Teacher. 2005;27(1):10-28. 4. McGaghie W, Petrusa ER, Gordon DL, Scalese RJ. A critical review of simulation-based medical education research: 2003-2009. Medical Education. 2010;44(1):50-63. 5. Simmons B, Egan-Lee E, Wagner SJ, Esdaile M, Baker L, Reeves S. Assessment of interprofessional learning: the design of an interprofessional objective structured clinical examination (iOSCE) approach. Journal of Interprofessional Care. 2011;25(1):73-74. 6. Nestel D, Layat Burn C, Pritchard SA, Glastonbury R, Tabak D. The use of simulated patients in medical education: Guide Supplement 42.1 - Viewpoint. Medical teacher. 2011;33(12):1027-1029. Disclosures: None (C) 2014 by Lippincott Williams & Wilkins, Inc.