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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
321

Attentional bias retraining in cigarette smokers attempting smoking cessation (ARTS): study protocol for a double blind randomised controlled trial

Begh, R., Munafò, M.R., Shiffman, S., Ferguson, S.G., Nichols, L., Mohammed, Mohammed A., Holder, R.L., Sutton, S., Aveyard, P. January 2013 (has links)
Yes / Smokers attend preferentially to cigarettes and other smoking-related cues in the environment, in what is known as an attentional bias. There is evidence that attentional bias may contribute to craving and failure to stop smoking. Attentional retraining procedures have been used in laboratory studies to train smokers to reduce attentional bias, although these procedures have not been applied in smoking cessation programmes. This trial will examine the efficacy of multiple sessions of attentional retraining on attentional bias, craving, and abstinence in smokers attempting cessation. This is a double-blind randomised controlled trial. Adult smokers attending a 7-session weekly stop smoking clinic will be randomised to either a modified visual probe task with attentional retraining or placebo training. Training will start 1 week prior to quit day and be given weekly for 5 sessions. Both groups will receive 21 mg transdermal nicotine patches for 8–12 weeks and withdrawal-orientated behavioural support for 7 sessions. Primary outcome measures are the change in attentional bias reaction time and urge to smoke on the Mood and Physical Symptoms Scale at 4 weeks post-quit. Secondary outcome measures include differences in withdrawal, time to first lapse and prolonged abstinence at 4 weeks post-quit, which will be biochemically validated at each clinic visit. Follow-up will take place at 8 weeks, 3 months and 6 months post-quit. This is the first randomised controlled trial of attentional retraining in smokers attempting cessation. This trial could provide proof of principle for a treatment aimed at a fundamental cause of addiction. / National Institute for Health Research (NIHR) Doctoral Research Fellowship (DRF) awarded to RB (DRF-2009-02-15)
322

Putting Life in Years (PLINY): a randomised controlled trial and mixed-methods process evaluation of a telephone friendship intervention to improve mental well-being in independently living older people

Hind, D., Mountain, Gail, Gossage-Worrall, R., Walters, S.J., Duncan, R., Newbould, L., Rex, S., Jones, C., Bowling, A., Cattan, M., Cairns, A., Cooper, C., Goyder, E.C., Tudor Edwards, R. 12 1900 (has links)
Yes / Social isolation in older adults is associated with morbidity. Evaluating interventions to promote social engagement is a research priority. Methods: A parallel-group randomised controlled trial was planned to evaluate whether telephone friendship (TF) improves the well-being of independently living older people. An internal pilot aimed to recruit 68 participants by 30 September 2012, with 80% retained at 6 months. Randomisation was web based and only analysts were blind to allocation. A service provider was contracted to train 10 volunteer facilitators by 1 April 2012 and 10 more by 1 September 2012. Participants were aged > 74 years with good cognitive function and living independently in an urban community. The intervention arm of the trial consisted of manualised TF with standardised training: (1) one-to-one befriending (10- to 20-minute calls once per week for up to 6 weeks made by volunteer facilitators) followed by (2) TF groups of six participants (1-hour teleconferences once per week for 12 weeks facilitated by the same volunteer). Friendship groups aimed to enhance social support and increase opportunities for social interaction to maintain well-being. This was compared with usual health and social care provision. The primary clinical outcome was the Short Form questionnaire-36 items (SF-36) mental health dimension score at 6 months post randomisation. Qualitative research assessing intervention acceptability (participants) and implementation issues (facilitators) and an intervention fidelity assessment were also carried out. Intervention implementation was documented through e-mails, meeting minutes and field notes. Acceptability was assessed through framework analysis of semistructured interviews. Two researchers coded audio recordings of telephone discussions for fidelity using a specially designed checklist. Results: In total, 157 people were randomised to the TF group (n = 78) or the control group (n = 79). Pilot recruitment and retention targets were met. Ten volunteers were trained by 1 September 2012; after volunteer attrition, three out of the 10 volunteers delivered the group intervention. In total, 50 out of the 78 TF participants did not receive the intervention and the trial was closed early. A total of 56 people contributed primary outcome data from the TF (n = 26) and control (n = 30) arms. The mean difference in SF-36 mental health score was 9.5 (95% confidence interval 4.5 to 14.5) after adjusting for age, sex and baseline score. Participants who were interviewed (n = 19) generally declared that the intervention was acceptable. Participant dissatisfaction with closure of the groups was reported (n = 4). Dissatisfaction focused on lack of face-to-face contact and shared interests or attitudes. Larger groups experienced better cohesion. Interviewed volunteers (n = 3) expressed a lack of clarity about procedures, anxieties about managing group dynamics and a lack of confidence in the training and in their management and found scheduling calls challenging. Training was 91–95% adherent with the checklist (39 items; three groups). Intervention fidelity ranged from 30.2% to 52.1% (28–41 items; three groups, three time points), indicating that groups were not facilitated in line with training, namely with regard to the setting of ground rules, the maintenance of confidentiality and facilitating contact between participants. Conclusions: Although the trial was unsuccessful for a range of logistical reasons, the experience gained is of value for the design and conduct of future trials. Participant recruitment and retention were feasible. Small voluntary sector organisations may be unable to recruit, train and retain adequate numbers of volunteers to implement new services at scale over a short time scale. Such risks might be mitigated by multicentre trials using multiple providers and specialists to recruit and manage volunteers. / Funding for this study was provided by the Public Health Research programme of the National Institute for Health Research.
323

Sample size re-estimation in active controlled non-inferiority clinical trials using a frequentist approach

Guo, Wei 20 September 2024 (has links)
In active controlled clinical trials a possible objective is to test a non-inferiority hypothesis that the experimental treatment is therapeutically not inferior to the active control within a pre-defined margin. At the design stage, the misspecification of any design parameters (e.g., the variance or treatment difference for continuous endpoints, control event rate or non-inferiority margin for binary endpoints) can lead to study power below the desired level. Sample size re-estimation (SSR) procedures protect study power by allowing sample size re-estimation based on an interim analysis using revised estimates of the design parameters. For continuous endpoints, current approaches to SSR for non-inferiority trials focus on updating the sample size based solely on the estimated variance (blinded or unblinded) at the interim. The SSR using both sample variance and the observed treatment difference at interim in conditional power calculations is used in superiority trials. We have extended the methodology to non-inferiority trials, quantified the effect on the type I error rate, and proposed controlling it by modifying the critical value and/or stopping the trial at the interim for futility. For binary endpoints, current approaches to SSR for non-inferiority trials focus on estimating the event rates (blinded or unblinded) at the interim and update the sample size solely on the estimated event rates at the interim without updating the non-inferiority margin. A procedure that adapts both the absolute non-inferiority margin, and sample size based on the underlying interim observed pooled (blinded) event rate, and updates non-inferiority margin again at the final analysis based on the observed estimate of the event rate in control group at the end of the study is proposed. Our simulation results show the proposed adaptive procedures for extending a study by adding sample size, if necessary, preserve the overall type I error rate and maintain desired power. Combining sample size re-estimation methods with early stopping rules for continuous endpoints and adapting non-inferiority margins for binary endpoints could increase study flexibility, scope, and efficiency of non-inferiority trials. The proposed methodologies can be used for designing efficient two-stage non-inferiority trials with sample size re-estimation in active controlled non-inferiority clinical trials.
324

Physical activity and breast cancer

Lahart, I. M. January 2014 (has links)
Background: Breast cancer is the most frequently diagnosed cancer and a leading cause of cancer death among females, both worldwide and in the UK. Although, UK incidence of breast cancer is rising, breast cancer mortality rates are falling, due largely to early detection and improved treatment. As a result there are more women living with a diagnosis of breast cancer than ever before. Due mainly to side-effects of adjuvant therapy, breast cancer patients may require diagnostic, therapeutic, supportive or palliative services many years post-diagnosis, which poses a major challenge to already stretched healthcare services. Accordingly, effective and inexpensive interventions that can alleviate treatment side-effects, improve health, quality of life and potentially reduce risk of early mortality are required for breast cancer patients. Awareness of the positive influence that physical activity can have on breast cancer development and outcome is an important determinant of physical activity levels. A higher level of physical activity before and after breast cancer diagnosis is related to a lower risk of all-cause and breast cancer-related mortality. Randomised controlled trials have reported beneficial effects of physical activity interventions on outcomes relating to health, quality of life and mortality risk among breast cancer survivors. Aims: The present project aimed to: 1) assess awareness of the role of physical activity on breast cancer risk and the sufficiency of physical activity undertaken in women attending the NHS breast screening programme (NHSBSP), 2) compare physical activity levels of women at different stages of breast cancer pathway, 3) investigate the effects of a low-cost six-month home-based physical activity intervention on physical activity, body mass, health-related quality of life (HRQoL), insulin resistance and blood lipid profiles of breast cancer survivors and 4) assess the effects of our home-based intervention on cardiorespiratory fitness in a subset of breast cancer survivors. Methods: A total of 309 volunteers (188 NHSBSP attendees, 41 breast cancer patients undergoing chemotherapy and 80 post-treatment breast cancer survivors) participated in the current project. Physical activity was assessed via the International Physical activity Questionnaires (IPAQ). In studies one and two, Body mass and body mass index (BMI) were assessed directly in chemotherapy patients and breast cancer survivors, and indirectly from self-reported values in NHSBSP attendees. While in study three, body fat percentage was measured via bioelectrical impedance analysis, HRQoL was assessed using the Functional Assessment of Cancer Therapy-Breast (FACT-B) questionnaire and fasting blood samples were taken to measure lipid, glucose and insulin concentrations at baseline and post-six month home-based physical activity intervention. In study four, a random subsample of 32 breast cancer survivors undertook an exercise tolerance test to establish peak oxygen uptake values. Results: A high proportion (70%) of NHSBSP attendees engaged in low-moderate levels of physical activity and performed low amounts of recreational physical activity. Attendees demonstrated high awareness (75%) of the role of physical activity in reducing breast cancer risk but those categorised as “low activity” were significantly unaware of insufficiency of activity (p<0.05). Chemotherapy patients and breast cancer survivors had significantly lower levels of total physical activity than NHSBSP attendees (p<0.001 and p<0.05, respectively). The randomised controlled trial revealed significant improvements in total physical activity, body mass (p<0.05), BMI (p<0.05) HRQoL (breast cancer subscale, p<0.01; trial outcome index, p<0.05) and total (p<0.01) and low-density lipoprotein (p<0.05) cholesterol concentrations in the intervention group compared to usual care, and significant improvements in cardiorespiratory fitness (p<0.05) in a subsample of breast cancer survivors allocated to intervention. Conclusions: Physical activity interventions that incorporate strategies aimed at increasing awareness of recommended physical activity guidelines may be required in populations at risk of breast cancer. A relatively large proportion of women at risk of breast cancer may not be sufficiently exposed to the potential benefits of physical activity on breast cancer outcomes. Post-treatment breast cancer patients may be more receptive to physical activity interventions as the negative effects of chemotherapy begin to resolve, and therefore, may benefit from physical activity interventions. Results suggest that a low-cost home-based physical activity intervention with counselling and telephone support can improve the health and HRQoL of breast cancer survivors, which may in turn potentially reduce risk of breast cancer and cardiovascular disease-related mortality. Given the encouraging results and its highly portable and feasible nature, our intervention represents a promising tool for use in health and community settings to benefit large numbers of breast cancer survivors. The current project supports the inclusion of physical activity promotion as an integral component for the management and care of breast cancer survivors.
325

Economic evaluation of factorial randomised controlled trials

Dakin, Helen A. January 2015 (has links)
Factorial randomised controlled trials (RCTs) evaluate two or more interventions simultaneously, enabling assessment of interactions between treatments. This thesis presents literature reviews, methodological reviews, simulation studies and applied case studies that explore methods for assessing cost-effectiveness based on factorial RCTs. My systematic review suggests that factorial RCTs account for around 3% of trial-based economic evaluations, although there is currently no guidance or methodological work indicating the most appropriate methods. Around 40% of published studies assumed no interaction between treatments and many were poorly-reported. Various mechanisms are likely to produce large interactions within economic endpoints such as costs, quality-adjusted life-years (QALYs) and net benefits. Failing to take account of interactions can introduce bias and prevent efficient allocation of healthcare resources. I developed the opportunity cost of ignoring interactions as a measure of the implications of this bias. However, allowing for small, chance interactions is inefficient, potentially leading to over-investment in research if trial-based evaluations are used to inform decisions about subsequent research. Nonetheless, analyses on simulated trial data suggest that the opportunity cost of adopting a treatment that will not maximise health gains from the healthcare budget is minimised by including all interactions regardless of magnitude or statistical significance. Different approaches for conducting economic evaluations of factorial RCTs (including regression techniques, extrapolation using patient-level simulation, and considering different components of net benefit separately) are evaluated within three applied studies, including both full and partial factorials with 2x2 and 2x2x2 designs. I demonstrate that within both trial-based and model-based economic evaluation, efficient allocation of healthcare resources requires consideration of interactions between treatments, and joint decisions about interacting treatments based on incremental cost-effectiveness evaluated “inside-the-table” on a natural scale. I make recommendations for the design, analysis and reporting of factorial trial-based economic evaluations based on the results of this thesis.
326

La collègialité dans le procès civil / Collegiality in the civil lawsuit

Chaput, Jade 23 May 2019 (has links)
La collégialité est un mode d’organisation juridictionnel qui a su traverser différentes phases historiques. Le XXIème siècle pourrait être une époque charnière puisqu’il se caractérise par le développement des nouvelles technologies. Si de tout temps les justiciables ont souhaité obtenir une réponse rapide à leur litige, cette célérité d’accès à l’information ne fait qu’accroître leur attente. Or, la collégialité nécessite du temps. A cela s’ajoute son coût. Le droit positif témoigne une restriction d’accès à la collégialité au second degré tandis qu’elle est en discussion devant la Cour de cassation. Cette limitation n’est pas en désaccord avec la volonté de la préserver alors qu’elle ne doit pas conduire à terme à son éviction. Deux raisons justifient son maintien. La première est qu’elle renforce certaines garanties du droit à un procès équitable et ce, parfois de manière perceptible. La seconde raison tient au fait qu’elle permet de contrecarrer la complexité d’un litige comme l’illustre le renvoi d’une affaire à une collégialité. Les propositions afin de réduire ses contraintes matérielles sont multiples. Elles puisent leur inspiration dans le droit interne mais aussi externe, la collégialité n’étant pas une exception française. / Collegiality is a jurisdictional organization that has gone through different historical phases. The 21st century could be a pivotal time as it is characterized by the development of new technologies. If at all times litigants have wanted a quick response to their dispute, this speed of access to information only increases their expectations. However, collegiality requires time. To this is added its cost. Positive law testifies to a restriction of access to collegiality in the second degree while it is under discussion in the Court of Cassation. This limitation is not at odds with the desire to preserve it, although it should not ultimately lead to its removal. Two reasons justify its maintenance. The first is that it reinforces certain guarantees of the right to a fair trial, sometimes in a perceptible way. The second reason is that it makes it possible to counteract the complexity of litigation as illustrated by the referral of a case to collegiality. The proposals to reduce its material constraints are multiple. They draw their inspiration from internal but also external law, collegiality not being a French exception.
327

Efficacité de trois stratégies de prévention du surpoids et de l'obésité à l'adolescence. Un essai avec randomisation en grappes / Effectiveness of three overweight and obesity prevention strategies in adolescence. A cluster randomised trial

Bonsergent, Émilie 22 August 2012 (has links)
Contexte : Etant donné la forte progression de la prévalence du surpoids et de l'obésité à l'adolescence ces dernières décennies, la prévention est devenue une priorité de santé publique internationale. Objectif : L'essai PRALIMAP (PRomotion de l'ALIMentation et de l'Activité Physique) évalue l'impact de trois stratégies de prévention du surpoids et de l'obésité - « Education », « Environnement », « Dépistage » - chez les adolescents en milieu scolaire, sur la corpulence, les connaissances, attitudes et comportements des adolescents vis-à-vis de la nutrition (alimentation et activité physique). Méthode : Les trois stratégies ont été affectées à 24 lycées de la région Lorraine (Nord-est de la France) sur 2 années (en classe de seconde et de première) par randomisation en grappe (=lycée), selon un plan factoriel 2x2x2. La stratégie Éducation consistait en des cours et des travaux de groupe sur la nutrition et une fête nutritionnelle annuelle. La stratégie Environnement consistait à améliorer l'offre nutritionnelle des lycées et organiser une fête nutritionnelle annuelle. La stratégie Dépistage consistait en un repérage des adolescents en surpoids ou obèses suivi d'une prise en charge adaptée collective. Les données ont été recueillies à 3 reprises : à l'entrée en classe de seconde (T0), de première (T1) et de terminale (T2). L'indice de masse corporelle (IMC), son z-score et la proportion d'adolescents en surpoids ou obèses étaient les critères de jugement principaux. Les critères de jugement secondaires étaient les connaissances et comportements nutritionnels. Les différences d'évolution T0-T2 des critères de jugement entre les 12 lycées ayant bénéficié d'une stratégie et les 12 lycées témoins de cette stratégie a été analysée à l'aide de modèles mixtes. Une évaluation du processus a permis d'estimer la dose réelle d'intervention de chaque stratégie dans chacun des lycées. Résultats : La stratégie Dépistage a entrainé une amélioration de la corpulence : augmentation moins importante de l'IMC avec la stratégie Dépistage (+0,6 vs +0,7, p=0,0303), diminution plus importante du z-score de l'IMC (-0,9 vs -0,5, p=0,0173) et de la prévalence du surpoids et de l'obésité (-2,3% vs -0,6%, p=0,0386). La stratégie Education a entrainé une amélioration de certains comportements nutritionnels : augmentation plus importante de la proportion d'adolescent suivant la recommandation nutritionnelle sur les féculents (3,6% vs -0,7%, p=0,0357) et du nombre d'activités physiques pratiquées (+0,02 vs -0,10, p=0,0047). La stratégie Environnement a amélioré les comportements et les connaissances nutritionnels : diminution moins importante de la proportion d'adolescents suivant la recommandation nutritionnelle sur le nombre de repas hebdomadaire (-4,5% vs -8,5%, p=0,0101) et amélioration plus importante du score de connaissances nutritionnelles (+1,9 point vs +1,0 point, p=0,0094). Des différences dans la réalisation des activités et la participation ont été mises en évidence suite à l'estimation de la dose d'intervention et peuvent expliquer certains résultats observés. Conclusion : Une stratégie de dépistage structurée en milieu scolaire apparaît bénéfique sur la réduction du surpoids et de l'obésité. L'addition d'activités d'éducation nutritionnelles dans le cursus n'induit pas d'effets sur la corpulence à court terme. La modification de l'environnement nutritionnel scolaire semble avoir un effet sur les indicateurs intermédiaires de connaissances et comportements nutritionnels / Background: Given the increasing prevalence of youth overweight and obesity in the last decade, prevention as become an international public health priority.Objective: The aim of The PRALIMAP (PRomotion de l'ALIMentation et de l'Activité Physique) trial was to evaluate the 2-year effectiveness of three strategies - « Education », « Screening » et « Environment »- aimed at preventing overweight and obesity among adolescents in high school setting on body size and nutritional knowledge and behaviours. Method: PRALIMAP was a school-based randomized controlled trial beginning in 24 state-run high schools (clusters) in Lorraine (north-eastern France). Each study high school was assigned to receive or not, over a 2-year period (grades 10 and 11), each of the three prevention strategies according to a 2x2x2 factorial school randomization. The prevention strategies were: ?education? (development of nutritional knowledge and skills), "environment" (creation of favourable environment by improving availability of dietary items with a good nutritional quality and physical activity), and "screening" (detection of overweight and obesity and, if necessary, adapted care management). The follow-up consisted of three visits: at the entry of grade 10(T0), grade 11(T1) and grade 12(T2). Body mass index (BMI), BMI z-score and prevalence of overweight and obesity were the main outcomes measures. Secondary outcomes measures were nutritional knowledge and behaviours. Comparisons of changes (T2-T0) of outcomes measures between each strategy schools and their control were carried out using a three-level hierarchical mixed model. A process evaluation allowed estimating an intervention dose really received by adolescents. Results: The 2-year change of anthropometric outcomes was more favourable in the 12 screening high schools as compared with the no-screening ones: a lower increase in BMI (+0,6 vs +0,7, p=0,0303), a greater decrease in BMI z-score (-0,9 vs -0,5, p=0,0173) and a greater decrease in overweight / obesity prevalence (-2,3% vs -0,6%, p=0,0386). The education strategy resulted in improved nutritional behaviours: a greater increase in achievement of starchy food guidelines (3,6% vs -0.7%, p=0.0357) and physical activity practice (+0,02 vs -0,10, p=0,0047). The environment strategy resulted in improved nutritional attitudes: a lower decrease in achievement of number of weekly meals guidelines (-4.5% vs -8.5%, p=0.0101) and greater increase in nutritional knowledge (+1,9 point vs +1,0 point, p=0.0094). Some differences in activity implementation and participation were highlighted and can explain some of the results observed. Conclusions: The screening strategy is an effective way to prevent, at two years, overweight and obesity among adolescents in a high school setting. Nutritional education added to the curriculum is not effective in the short term on body size. The school nutritional environment modification is slightly associated with improved nutritional knowledge and behaviours
328

"Modulação por mecanismos serotoninérgicos do comportamento exploratório de ratos submetidos ao teste e reteste no labirinto em cruz elevado" / "Modulation by serotonergic mechanisms of the exploratory behavior of rats submitted to the test and retest in the elevated plus-maze"

Lucas Albrechet de Souza 18 August 2006 (has links)
O labirinto em cruz elevado (LCE) é um dos testes de ansiedade mais empregados na atualidade. Uma característica intrigante desse modelo é a abolição dos efeitos ansiolíticos dos benzodiazepínicos como resultado de uma única experiência prévia no labirinto. Este fenômeno, chamado “one-trial tolerance” (OTT), tem recebido considerável atenção e dentre as diversas hipóteses sugeridas para explicá-lo, podemos citar uma alteração no estado emocional do animal, perda do conflito motivacional e habituação do comportamento exploratório. A descoberta de que benzodiazepínicos reduzem a atividade de neurônios serotoninérgicos, associada a resultados obtidos em testes de conflito que mostram que antagonistas serotoninérgicos podem causar efeitos ansiolíticos comparáveis aos benzodiazepínicos, levaram à noção de que a serotonina (5-HT) é o principal neurotransmissor envolvido na ansiedade. No entanto, com o uso de outros modelos animais, o envolvimento da 5-HT tem sido questionado, ao mesmo tempo em que outras aminas biogênicas, como a noradrenalina (NA), têm sido implicadas na modulação da ansiedade. Nesse estudo procedemos uma análise etofarmacológica de ratos tratados com o antagonista serotoninérgico cetanserina e os antidepressivos fluoxetina e desipramina submetidos ao teste e reteste no LCE. Esses antidepressivos aumentam os níveis sinápticos de 5-HT e NA, respectivamente. Além disso, foram medidas as concentrações plasmáticas de corticosterona - considerada um índice confiável de medo e estresse - de ratos expostos à sessão única ou repetida no LCE. As drogas administradas antes da reexposição ao labirinto não produziram efeitos ansiolíticos, replicando o fenômeno da OTT comumente associado aos benzodiazepínicos. Por outro lado, a cetanserina administrada antes da primeira sessão produziu um efeito ansiolítico, mas o tratamento subcrônica com fluoxetina e desipramina não alterou o comportamento exploratório dos animais no LCE. Ratos submetidos à sessão única ou repetida no labirinto apresentaram um aumento similar dos níveis plasmáticos de corticosterona, indicando que a reexposição ao LCE apresenta propriedades aversivas e a OTT deve estar mais relacionada à uma alteração no estado emocional do animal do que à habituação do comportamento exploratório. / The elevated plus-maze (EPM) is currently one of the most used test of anxiety. An intriguing feature of this model is the abolition of the anxiolytic effect of benzodiazepines by a single previous experience with the maze. This phenomenon, termed one-trial tolerance (OTT), has received considerable attention and among the several hypotheses suggested to explain it, we can listed a shift in the animal emotional state, lack of motivational conflict and exploratory behavior habituation. The discovery that benzodiazepines reduce the activity of serotonergic neurons, associated with results obtained in conflict tests showing that serotonergic antagonists may cause anxiolitic-like effects comparable to the benzodiazepines, has led to the notion that the serotonin (5-HT) is the most important neurotransmitter involved in the anxiety. Nevertheless, with the use of other animal models, the 5-HT involvement has been questioned, at the same time that other biogenic amines, such as noradrenalin (NA), have been implicated in the anxiety modulation. In this study, we carried out an ethopharmacological analysis of rats under treatment with the serotonergic antagonist ketanserin and the antidepressants fluoxetine and desipramine submitted to the test and retest in the EPM. These antidepressants increase the synaptic levels of 5-HT and NA, respectively. Besides, plasma corticosterone concentrations - considered a reliable index of fear and stress - of rats exposed once or twice to the EPM were measured. The drugs injected before the retest in the EPM did not produce anxiolytic effects, replicating the OTT phenomenon generally associated with the benzodiazepines. On the other hand, ketanserin injected before the first session produced an anxiolytic effect but the subchronic treatment with fluoxetine and desipramine did not change the exploratory behavior of the animals in the EPM. Naive and experienced rats show a similar increase in the plasma corticosterone levels when submitted to the EPM, indicating that the retest to EPM has aversive properties and the OTT may be more related to a change in the emotional state of the animal than to a habituation of the exploratory behavior.
329

"Modulação por mecanismos serotoninérgicos do comportamento exploratório de ratos submetidos ao teste e reteste no labirinto em cruz elevado" / "Modulation by serotonergic mechanisms of the exploratory behavior of rats submitted to the test and retest in the elevated plus-maze"

Souza, Lucas Albrechet de 18 August 2006 (has links)
O labirinto em cruz elevado (LCE) é um dos testes de ansiedade mais empregados na atualidade. Uma característica intrigante desse modelo é a abolição dos efeitos ansiolíticos dos benzodiazepínicos como resultado de uma única experiência prévia no labirinto. Este fenômeno, chamado “one-trial tolerance" (OTT), tem recebido considerável atenção e dentre as diversas hipóteses sugeridas para explicá-lo, podemos citar uma alteração no estado emocional do animal, perda do conflito motivacional e habituação do comportamento exploratório. A descoberta de que benzodiazepínicos reduzem a atividade de neurônios serotoninérgicos, associada a resultados obtidos em testes de conflito que mostram que antagonistas serotoninérgicos podem causar efeitos ansiolíticos comparáveis aos benzodiazepínicos, levaram à noção de que a serotonina (5-HT) é o principal neurotransmissor envolvido na ansiedade. No entanto, com o uso de outros modelos animais, o envolvimento da 5-HT tem sido questionado, ao mesmo tempo em que outras aminas biogênicas, como a noradrenalina (NA), têm sido implicadas na modulação da ansiedade. Nesse estudo procedemos uma análise etofarmacológica de ratos tratados com o antagonista serotoninérgico cetanserina e os antidepressivos fluoxetina e desipramina submetidos ao teste e reteste no LCE. Esses antidepressivos aumentam os níveis sinápticos de 5-HT e NA, respectivamente. Além disso, foram medidas as concentrações plasmáticas de corticosterona - considerada um índice confiável de medo e estresse - de ratos expostos à sessão única ou repetida no LCE. As drogas administradas antes da reexposição ao labirinto não produziram efeitos ansiolíticos, replicando o fenômeno da OTT comumente associado aos benzodiazepínicos. Por outro lado, a cetanserina administrada antes da primeira sessão produziu um efeito ansiolítico, mas o tratamento subcrônica com fluoxetina e desipramina não alterou o comportamento exploratório dos animais no LCE. Ratos submetidos à sessão única ou repetida no labirinto apresentaram um aumento similar dos níveis plasmáticos de corticosterona, indicando que a reexposição ao LCE apresenta propriedades aversivas e a OTT deve estar mais relacionada à uma alteração no estado emocional do animal do que à habituação do comportamento exploratório. / The elevated plus-maze (EPM) is currently one of the most used test of anxiety. An intriguing feature of this model is the abolition of the anxiolytic effect of benzodiazepines by a single previous experience with the maze. This phenomenon, termed one-trial tolerance (OTT), has received considerable attention and among the several hypotheses suggested to explain it, we can listed a shift in the animal emotional state, lack of motivational conflict and exploratory behavior habituation. The discovery that benzodiazepines reduce the activity of serotonergic neurons, associated with results obtained in conflict tests showing that serotonergic antagonists may cause anxiolitic-like effects comparable to the benzodiazepines, has led to the notion that the serotonin (5-HT) is the most important neurotransmitter involved in the anxiety. Nevertheless, with the use of other animal models, the 5-HT involvement has been questioned, at the same time that other biogenic amines, such as noradrenalin (NA), have been implicated in the anxiety modulation. In this study, we carried out an ethopharmacological analysis of rats under treatment with the serotonergic antagonist ketanserin and the antidepressants fluoxetine and desipramine submitted to the test and retest in the EPM. These antidepressants increase the synaptic levels of 5-HT and NA, respectively. Besides, plasma corticosterone concentrations - considered a reliable index of fear and stress - of rats exposed once or twice to the EPM were measured. The drugs injected before the retest in the EPM did not produce anxiolytic effects, replicating the OTT phenomenon generally associated with the benzodiazepines. On the other hand, ketanserin injected before the first session produced an anxiolytic effect but the subchronic treatment with fluoxetine and desipramine did not change the exploratory behavior of the animals in the EPM. Naive and experienced rats show a similar increase in the plasma corticosterone levels when submitted to the EPM, indicating that the retest to EPM has aversive properties and the OTT may be more related to a change in the emotional state of the animal than to a habituation of the exploratory behavior.
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Protection of the rights of an unpresented accused

Motubatse, Mosinki Justice January 2014 (has links)
Thesis (LLM. (Management and Development)) -- University of Limpopo, 2014 / Every accused person has the right to a fair trial which encompasses the right to adduce and challenge evidence in court. Whilst the Constitution of the Republic of South Africa confers the right to legal representation, an accused person may still opt to conduct his or her own defence. Once an unrepresented accused opts to conduct his or her own defence, the presiding officer then becomes obliged to assist the undefended accused to present his or her own case. South Africa adheres to the accusatorial / adversarial system. Under the accusatorial / adversarial system the presiding judicial officer is in the role of a detached umpire, who should not descend the arena of the duel between the state and the defence for fear of becoming partial or of losing perspective as a result of the dust caused by the affray between the state and the defence. Under the accusatorial/adversarial system, a presiding officer may find it challenging to assist an unrepresented accused or may inadequately assist him or her. This may be so because a fair trial is not determined by ensuring exercise of one of the rights to a fair trial but all the rights to a fair trial. This mini-dissertation, on the injunction of section 35 of the Constitution of the Republic of South Africa which makes provision for the rights to a fair trial, covers the different rights of an unrepresented accused. This is done alongside related provisions of the Criminal Procedure Act 51 of 1977 and pertinent case law. The fat that an unrepresented accused has waived legal representation at the expense of the state and has opted to conduct his or her own defence should not be to his or her peril. The court has a constitutional injunction to protect and advance the rights of an unrepresented accused. Justice must not only be done but must also be seen to be done.

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