996 resultados para Cognitive agent


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The construct of cognitive errors is clinically relevant for cognitive therapy of mood disorders. Beck's universality hypothesis postulates the relevance of negative cognitions in all subtypes of mood disorders, as well as positive cognitions for manic states. This hypothesis has rarely been empirically addressed for patients presenting bipolar affective disorder (BD). In-patients (n = 30) presenting with BD were interviewed, as were 30 participants of a matched control group. Valid and reliable observer-rater methodology for cognitive errors was applied to the session transcripts. Overall, patients make more cognitive errors than controls. When manic and depressive patients were compared, parts of the universality hypothesis were confirmed. Manic symptoms are related to positive and negative cognitive errors. These results are discussed with regard to the main assumptions of the cognitive model for depression; thus adding an argument for extending it to the BD diagnostic group, taking into consideration specificities in terms of cognitive errors. Clinical implications for cognitive therapy of BD are suggested.

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(from the journal abstract) Background: Despite the effectiveness of anti-psychotic pharmacotherapy, residual hallucinations and delusions do not completely resolve in some medicated patients. Additional cognitive behavioral therapy (CBT) seems to improve the management of positive symptoms. Despite promising results, the efficacy of CBT is still unclear. The present study addresses this issue taking into account a number of newly published controlled studies. Method: Fourteen studies including 1484 patients, published between 1990 and 2004 were identified and a meta-analysis of their results performed. Results: Compared to other adjunctive measures, CBT showed significant reduction in positive symptoms and there was a higher benefit of CBT for patients suffering an acute psychotic episode versus the chronic condition (effect size of 0.57 vs. 0.27). Discussion: CBT is a promising adjunctive treatment for positive symptoms in schizophrenia spectrum disorders. However, a number of potentially modifying variables have not yet been examined, such as therapeutic alliance and neuropsychological deficits. (PsycINFO Database Record (c) 2005 APA, all rights reserved)

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Three case studies are presented to investigate the possibility of evaluating memory and cognitive capacities of severe intellectual disability with attention given to the ecological environment. Two 22-year-old male patients and a 27-year-old male patient, all three with severe intellectual disability with no verbal communication skills, were evaluated with a new and original paradigm adapted to study cognition in humans from experimental paradigms. We developed a test based on animal models to complement the "home" scale of the Adolescent and Adult Psychoeducational Profile (AAPEP), an assessment instrument designed for adolescents and adults with severe developmental disabilities. Results show that the new instrument is helpful, not only to staff members who can better understand the poor performances of their patients in daily life activities but also in the elaboration of individual acquisition plans. These preliminary results demonstrate the interest in developing a larger controlled study and in publishing our procedure.

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The debate about Free Will has been in the human mind for centuries, but has become even more intense with the recent scientific findings adding new lights on the problem. This interdisciplinary explosion of interest for the topic has brought many insightful knowledge, but also a great deal of epistemological problems. We think that those epistemological problems are deeply related to the very definition of Free Will and how this definition interacts with the interpretations of experimental results. We will thus outline a few of these problems and then propose a definition of Free Will which takes into account those epistemological pitfalls.

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A lot of research in cognition and decision making suffers from a lack of formalism. The quantum probability program could help to improve this situation, but we wonder whether it would provide even more added value if its presumed focus on outcome models were complemented by process models that are, ideally, informed by ecological analyses and integrated into cognitive architectures.

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Sexual selection is responsible for the evolution of male ornaments and armaments, but its role in the evolution of cognition--the ability to process, retain and use information--is largely unexplored. Because successful courtship is likely to involve processing information in complex, competitive sexual environments, we hypothesized that sexual selection contributes to the evolution and maintenance of cognitive abilities in males. To test this, we removed mate choice and mate competition from experimental populations of Drosophila melanogaster by enforcing monogamy for over 100 generations. Males evolved under monogamy became less proficient than polygamous control males at relatively complex cognitive tasks. When faced with one receptive and several unreceptive females, polygamous males quickly focused on receptive females, whereas monogamous males continued to direct substantial courtship effort towards unreceptive females. As a result, monogamous males were less successful in this complex setting, despite being as quick to mate as their polygamous counterparts with only one receptive female. This diminished ability to use past information was not limited to the courtship context: monogamous males (but not females) also showed reduced aversive olfactory learning ability. Our results provide direct experimental evidence that the intensity of sexual selection is an important factor in the evolution of male cognitive ability.

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Optimizing collective behavior in multiagent systems requires algorithms to find not only appropriate individual behaviors but also a suitable composition of agents within a team. Over the last two decades, evolutionary methods have emerged as a promising approach for the design of agents and their compositions into teams. The choice of a crossover operator that facilitates the evolution of optimal team composition is recognized to be crucial, but so far, it has never been thoroughly quantified. Here, we highlight the limitations of two different crossover operators that exchange entire agents between teams: restricted agent swapping (RAS) that exchanges only corresponding agents between teams and free agent swapping (FAS) that allows an arbitrary exchange of agents. Our results show that RAS suffers from premature convergence, whereas FAS entails insufficient convergence. Consequently, in both cases, the exploration and exploitation aspects of the evolutionary algorithm are not well balanced resulting in the evolution of suboptimal team compositions. To overcome this problem, we propose combining the two methods. Our approach first applies FAS to explore the search space and then RAS to exploit it. This mixed approach is a much more efficient strategy for the evolution of team compositions compared to either strategy on its own. Our results suggest that such a mixed agent-swapping algorithm should always be preferred whenever the optimal composition of individuals in a multiagent system is unknown.

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Urinary incontinence can be treated by endoscopic injection of bulking agents, however, no optimal therapeutic effect has been achieved upon this treatment yet. In the present study, the development of a injectable poly(acrylonitrile) hydrogel paste is described, and its efficacy and histological behavior, once injected into the submucosal space of the minipig bladder, are evaluated. A device was developed to mix poly(acrylonitrile) hydrogel powder with glycerin, used as carrier, prior to injection into the submucosal space of the bladder. Several paste deposits, depending on the size of the bladder, were injected per animal. The implants were harvested at days 7, 14, 21, 28, 84 and 168 and analyzed morphologically and by histology. The persistence of the implants was demonstrated. However, at later time points the implants were split up and surrounded by granulomatous tissue, which was gradually replaced by histiocytes and adipocytes. Transitory focal urothelial metaplasia was observed only at day 7 and moderate foreign body reaction was detected predominantly between the second and fifth week. This study demonstrated the feasibility to develop an injectable paste of poly(acrylonitrile) hydrogel thought to provide the expected bulking effect, necessary for the treatment of urinary incontinence.

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It has been suggested that Ménière's disease is part of a polyganglionitis in which symptoms result from the reactivation of neurotropic virus within the internal auditory canal, and that intratympanic applications of an antiviral agent might be an efficient therapy. In 2002, we performed a pilot study ending with encouraging results. Control of vertigo was achieved in 80% of the 17 patients included. We present here a prospective, double-blind study, with a 2-year follow-up, in 29 patients referred by ENT practitioners for a surgical treatment after failure of a medical therapy. The participation in the study was offered to patients prior to surgery. A solution of ganciclovir 50 mg/ml or of NaCl 9% was delivered for 10 consecutive days via a microwick inserted into the tympanic membrane in the direction of the round window or through a ventilation tube. One patient was withdrawn from the study immediately after the end of the injections. He could not complete the follow-up period, because of persisting vertigo. As he had received the placebo, he was then treated with the solution of ganciclovir. Symptoms persisted and he underwent a vestibular neurectomy. Among the remaining 28 patients, surgery could be postponed in 22 (81%). Surgery remained necessary to control vertigo in 3 patients from the group that received the antiviral agent, and in 3 from the control group. Using an analogical scale, patients of both groups indicated a similar improvement of their health immediately after the intratympanic injections. The scores obtained with a 36-item short-form health survey quality of life questionnaire and the Dizziness Handicap Inventory were also similar for both groups. In conclusion, most patients were improved after the intratympanic injections, but there was no obvious difference between the treated and control groups. The benefit might be due to the middle ear ventilation or reflect an improvement in the patients' emotional state.

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Background and Aims: The three anti-TNF agents infliximab (IFX), adalimumab (ADA) andcertolizumab pegol (CZP) have demonstrated similar efficacy in induction and maintenanceof response and remission in Crohn's disease (CD) treatment. Given the comparability ofthese drugs, patient's preferences may influence the choice of the product. However, dataon patient's preferences for choosing anti-TNF agents are lacking. We therefore aimed toassess the CD patient's appraisal to select the drug of his choice and to identify factorsguiding this decision.Methods: A prospective survey among anti-TNF-naive CD patientswas performed. Patients were provided a description of the three anti-TNF agents focusingon indication, application mode (s.c. vs. i.v.), application time intervals, setting of application(hospital vs. private practice vs. patient's home), average time to apply the medication permonth, typical side effects, and the scientific evidence of efficacy and safety available for everydrug. Patients answered a questionnaire consisting of 17 questions, covering demographic,disease-specific, and medication data.Results: Hundred patients (47f/53m, mean age 45±16years) completed the questionnaire. Disease duration was <1year in 7%, 1-5 years in 31%,and >5 years in 62% of patients. Disease location was ileal in 33%, colonic in 40%, andileocolonic in 27%. Disease phenotype was inflammatory in 68%, stenosing in 29%, andinternally fistulizing in 3% of patients. Additionally, 20% had perianal fistulizing disease.Patients were already treated with the following drugs: mesalamines 61%, budesonide 44%,prednisone 97%, thiopurines 78%, methotrexate 16%. In total, 30% had already heardabout IFX, 20% about ADA, and 11% about CZP. Thirty-six percent voted for treatmentwith ADA, 28% for CZP, and 25% for IFX, whereas 11% were undecided. The followingfactors influenced the patient's decision for choosing a specific anti-TNF drug (severalanswers possible): side effects 76%, physician's recommendation 66%, application mode54%, efficacy experience 52%, time to spend for therapy 27%, patient's recommendations21%, interactions with other medications 12%. The single most important factor for choosinga specific anti-TNF was (1 answer): side effect profile 35%, physician's recommendation22%, efficacy experience 21%, application mode 13%, patient's recommendations 5%, timespent for therapy 3%, interaction with other medications 1%.Conclusions: The majority ofpatients preferred anti-TNF syringes to infusions. The safety profile of the drugs and thephysician's recommendation are major factors influencing the patient's choice for a specificanti-TNF drug. Patient's issues about safety and lifestyle habits should be taken into accountwhen prescribing specific anti-TNF formulations.

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BACKGROUND AND OBJECTIVES: The SBP values to be achieved by antihypertensive therapy in order to maximize reduction of cardiovascular outcomes are unknown; neither is it clear whether in patients with a previous cardiovascular event, the optimal values are lower than in the low-to-moderate risk hypertensive patients, or a more cautious blood pressure (BP) reduction should be obtained. Because of the uncertainty whether 'the lower the better' or the 'J-curve' hypothesis is correct, the European Society of Hypertension and the Chinese Hypertension League have promoted a randomized trial comparing antihypertensive treatment strategies aiming at three different SBP targets in hypertensive patients with a recent stroke or transient ischaemic attack. As the optimal level of low-density lipoprotein cholesterol (LDL-C) level is also unknown in these patients, LDL-C-lowering has been included in the design. PROTOCOL DESIGN: The European Society of Hypertension-Chinese Hypertension League Stroke in Hypertension Optimal Treatment trial is a prospective multinational, randomized trial with a 3 × 2 factorial design comparing: three different SBP targets (1, <145-135; 2, <135-125; 3, <125 mmHg); two different LDL-C targets (target A, 2.8-1.8; target B, <1.8 mmol/l). The trial is to be conducted on 7500 patients aged at least 65 years (2500 in Europe, 5000 in China) with hypertension and a stroke or transient ischaemic attack 1-6 months before randomization. Antihypertensive and statin treatments will be initiated or modified using suitable registered agents chosen by the investigators, in order to maintain patients within the randomized SBP and LDL-C windows. All patients will be followed up every 3 months for BP and every 6 months for LDL-C. Ambulatory BP will be measured yearly. OUTCOMES: Primary outcome is time to stroke (fatal and non-fatal). Important secondary outcomes are: time to first major cardiovascular event; cognitive decline (Montreal Cognitive Assessment) and dementia. All major outcomes will be adjudicated by committees blind to randomized allocation. A Data and Safety Monitoring Board has open access to data and can recommend trial interruption for safety. SAMPLE SIZE CALCULATION: It has been calculated that 925 patients would reach the primary outcome after a mean 4-year follow-up, and this should provide at least 80% power to detect a 25% stroke difference between SBP targets and a 20% difference between LDL-C targets.

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BACKGROUND: Mantle cell lymphoma accounts for 6% of all B-cell lymphomas and is generally incurable. It is characterized by the translocation t(11;14) leading to cyclin D1 over-expression. Cyclin D1 is downstream of the mammalian target of rapamycin threonine kinase and can be effectively blocked by mammalian target of rapamycin inhibitors. We set out to examine the single agent activity of the orally available mammalian target of rapamycin inhibitor everolimus in a prospective, multicenter trial in patients with relapsed or refractory mantle cell lymphoma (NCT00516412). DESIGN AND METHODS: Eligible patients who had received a maximum of three prior lines of chemotherapy were given everolimus 10 mg for 28 days (one cycle) for a total of six cycles or until disease progression. The primary endpoint was the best objective response. Adverse reactions, progression-free survival and molecular response were secondary endpoints. RESULTS: Thirty-six patients (35 evaluable) were enrolled and treatment was generally well tolerated with Common Terminology Criteria grade ≥ 3 adverse events (>5%) including anemia (11%), thrombocytopenia (11%) and neutropenia (8%). The overall response rate was 20% (95% CI: 8-37%) with two complete remissions and five partial responses; 49% of the patients had stable disease. At a median follow-up of 6 months, the median progression-free survival was 5.5 months (95% CI: 2.8-8.2) overall and 17.0 (6.4-23.3) months for 18 patients who received six or more cycles of treatment. Three patients achieved a lasting complete molecular response, as assessed by polymerase chain reaction analysis of peripheral blood. CONCLUSIONS: Everolimus as a single agent is well tolerated and has anti-lymphoma activity in relapsed or refractory mantle cell lymphoma. Further studies of everolimus in combination with chemotherapy or as a single agent for maintenance treatment are warranted.

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Taphrina deformans is a fungus responsible for peach leaf curl, an important plant disease. It is phylogenetically assigned to the Taphrinomycotina subphylum, which includes the fission yeast and the mammalian pathogens of the genus Pneumocystis. We describe here the genome of T. deformans in the light of its dual plant-saprophytic/plant-parasitic lifestyle. The 13.3-Mb genome contains few identifiable repeated elements (ca. 1.5%) and a relatively high GC content (49.5%). A total of 5,735 protein-coding genes were identified, among which 83% share similarities with other fungi. Adaptation to the plant host seems reflected in the genome, since the genome carries genes involved in plant cell wall degradation (e.g., cellulases and cutinases), secondary metabolism, the hallmark glyoxylate cycle, detoxification, and sterol biosynthesis, as well as genes involved in the biosynthesis of plant hormones. Genes involved in lipid metabolism may play a role in its virulence. Several locus candidates for putative MAT cassettes and sex-related genes akin to those of Schizosaccharomyces pombe were identified. A mating-type-switching mechanism similar to that found in ascomycetous yeasts could be in effect. Taken together, the findings are consistent with the alternate saprophytic and parasitic-pathogenic lifestyles of T. deformans. IMPORTANCE: Peach leaf curl is an important plant disease which causes significant losses of fruit production. We report here the genome sequence of the causative agent of the disease, the fungus Taphrina deformans. The genome carries characteristic genes that are important for the plant infection process. These include (i) proteases that allow degradation of the plant tissues; (ii) secondary metabolites which are products favoring interaction of the fungus with the environment, including the host; (iii) hormones that are responsible for the symptom of severely distorted leaves on the host; and (iv) drug detoxification enzymes that confer resistance to fungicides. The availability of the genome allows the design of new drug targets as well as the elaboration of specific management strategies to fight the disease.

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ABSTRACT: INTRODUCTION: Lipoprotein-associated phospholipase A2 (Lp-PLA2) is a circulating enzyme with pro-inflammatory and oxidative activities associated with cardiovascular disease and ischemic stroke. While high plasma Lp-PLA2 activity was reported as a risk factor for dementia in the Rotterdam study, no association between Lp-PLA2 mass and dementia or Alzheimer's disease (AD) was detected in the Framingham study. The objectives of the current study were to explore the relationship of plasma Lp-PLA2 activity with cognitive diagnoses (AD, amnestic mild cognitive impairment (aMCI), and cognitively healthy subjects), cardiovascular markers, cerebrospinal fluid (CSF) markers of AD, and apolipoprotein E (APOE) genotype. METHODS: Subjects with mild AD (n = 78) and aMCI (n = 59) were recruited from the Memory Clinic, University Hospital, Basel, Switzerland; cognitively healthy subjects (n = 66) were recruited from the community. Subjects underwent standardised medical, neurological, neuropsychological, imaging, genetic, blood and CSF evaluation. Differences in Lp-PLA2 activity between the cognitive diagnosis groups were tested with ANOVA and in multiple linear regression models with adjustment for covariates. Associations between Lp-PLA2 and markers of cardiovascular disease and AD were explored with Spearman's correlation coefficients. RESULTS: There was no significant difference in plasma Lp-PLA2 activity between AD (197.1 (standard deviation, SD 38.4) nmol/min/ml) and controls (195.4 (SD 41.9)). Gender, statin use and low-density lipoprotein cholesterol (LDL) were independently associated with Lp-PLA2 activity in multiple regression models. Lp-PLA2 activity was correlated with LDL and inversely correlated with high-density lipoprotein (HDL). AD subjects with APOE-ε4 had higher Lp-PLA2 activity (207.9 (SD 41.2)) than AD subjects lacking APOE-ε4 (181.6 (SD 26.0), P = 0.003) although this was attenuated by adjustment for LDL (P = 0.09). No strong correlations were detected for Lp-PLA2 activity and CSF markers of AD. CONCLUSION: Plasma Lp-PLA2 was not associated with a diagnosis of AD or aMCI in this cross-sectional study. The main clinical correlates of Lp-PLA2 activity in AD, aMCI and cognitively healthy subjects were variables associated with lipid metabolism.

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Disorders of language, spatial perception, attention, memory, calculation and praxis are a frequent consequence of acquired brain damage [in particular, stroke and traumatic brain injury (TBI)] and a major determinant of disability. The rehabilitation of aphasia and, more recently, of other cognitive disorders is an important area of neurological rehabilitation. We report here a review of the available evidence about effectiveness of cognitive rehabilitation. Given the limited number and generally low quality of randomized clinical trials (RCTs) in this area of therapeutic intervention, the Task Force considered, besides the available Cochrane reviews, evidence of lower classes which was critically analysed until a consensus was reached. In particular, we considered evidence from small group or single cases studies including an appropriate statistical evaluation of effect sizes. The general conclusion is that there is evidence to award a grade A, B or C recommendation to some forms of cognitive rehabilitation in patients with neuropsychological deficits in the post-acute stage after a focal brain lesion (stroke, TBI). These include aphasia therapy, rehabilitation of unilateral spatial neglect (ULN), attentional training in the post-acute stage after TBI, the use of electronic memory aids in memory disorders, and the treatment of apraxia with compensatory strategies. There is clearly a need for adequately designed studies in this area, which should take into account specific problems such as patient heterogeneity and treatment standardization.