959 resultados para Clinical trials


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Objective: To develop a method for objective quantification of PD motor symptoms related to Off episodes and peak dose dyskinesias, using spiral data gathered by using a touch screen telemetry device. The aim was to objectively characterize predominant motor phenotypes (bradykinesia and dyskinesia), to help in automating the process of visual interpretation of movement anomalies in spirals as rated by movement disorder specialists. Background: A retrospective analysis was conducted on recordings from 65 patients with advanced idiopathic PD from nine different clinics in Sweden, recruited from January 2006 until August 2010. In addition to the patient group, 10 healthy elderly subjects were recruited. Upper limb movement data were collected using a touch screen telemetry device from home environments of the subjects. Measurements with the device were performed four times per day during week-long test periods. On each test occasion, the subjects were asked to trace pre-drawn Archimedean spirals, using the dominant hand. The pre-drawn spiral was shown on the screen of the device. The spiral test was repeated three times per test occasion and they were instructed to complete it within 10 seconds. The device had a sampling rate of 10Hz and measured both position and time-stamps (in milliseconds) of the pen tip. Methods: Four independent raters (FB, DH, AJ and DN) used a web interface that animated the spiral drawings and allowed them to observe different kinematic features during the drawing process and to rate task performance. Initially, a number of kinematic features were assessed including ‘impairment’, ‘speed’, ‘irregularity’ and ‘hesitation’ followed by marking the predominant motor phenotype on a 3-category scale: tremor, bradykinesia and/or choreatic dyskinesia. There were only 2 test occasions for which all the four raters either classified them as tremor or could not identify the motor phenotype. Therefore, the two main motor phenotype categories were bradykinesia and dyskinesia. ‘Impairment’ was rated on a scale from 0 (no impairment) to 10 (extremely severe) whereas ‘speed’, ‘irregularity’ and ‘hesitation’ were rated on a scale from 0 (normal) to 4 (extremely severe). The proposed data-driven method consisted of the following steps. Initially, 28 spatiotemporal features were extracted from the time series signals before being presented to a Multilayer Perceptron (MLP) classifier. The features were based on different kinematic quantities of spirals including radius, angle, speed and velocity with the aim of measuring the severity of involuntary symptoms and discriminate between PD-specific (bradykinesia) and/or treatment-induced symptoms (dyskinesia). A Principal Component Analysis was applied on the features to reduce their dimensions where 4 relevant principal components (PCs) were retained and used as inputs to the MLP classifier. Finally, the MLP classifier mapped these components to the corresponding visually assessed motor phenotype scores for automating the process of scoring the bradykinesia and dyskinesia in PD patients whilst they draw spirals using the touch screen device. For motor phenotype (bradykinesia vs. dyskinesia) classification, the stratified 10-fold cross validation technique was employed. Results: There were good agreements between the four raters when rating the individual kinematic features with intra-class correlation coefficient (ICC) of 0.88 for ‘impairment’, 0.74 for ‘speed’, 0.70 for ‘irregularity’, and moderate agreements when rating ‘hesitation’ with an ICC of 0.49. When assessing the two main motor phenotype categories (bradykinesia or dyskinesia) in animated spirals the agreements between the four raters ranged from fair to moderate. There were good correlations between mean ratings of the four raters on individual kinematic features and computed scores. The MLP classifier classified the motor phenotype that is bradykinesia or dyskinesia with an accuracy of 85% in relation to visual classifications of the four movement disorder specialists. The test-retest reliability of the four PCs across the three spiral test trials was good with Cronbach’s Alpha coefficients of 0.80, 0.82, 0.54 and 0.49, respectively. These results indicate that the computed scores are stable and consistent over time. Significant differences were found between the two groups (patients and healthy elderly subjects) in all the PCs, except for the PC3. Conclusions: The proposed method automatically assessed the severity of unwanted symptoms and could reasonably well discriminate between PD-specific and/or treatment-induced motor symptoms, in relation to visual assessments of movement disorder specialists. The objective assessments could provide a time-effect summary score that could be useful for improving decision-making during symptom evaluation of individualized treatment when the goal is to maximize functional On time for patients while minimizing their Off episodes and troublesome dyskinesias.

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A challenge for the clinical management of advanced Parkinson’s disease (PD) patients is the emergence of fluctuations in motor performance, which represents a significant source of disability during activities of daily living of the patients. There is a lack of objective measurement of treatment effects for in-clinic and at-home use that can provide an overview of the treatment response. The objective of this paper was to develop a method for objective quantification of advanced PD motor symptoms related to off episodes and peak dose dyskinesia, using spiral data gathered by a touch screen telemetry device. More specifically, the aim was to objectively characterize motor symptoms (bradykinesia and dyskinesia), to help in automating the process of visual interpretation of movement anomalies in spirals as rated by movement disorder specialists. Digitized upper limb movement data of 65 advanced PD patients and 10 healthy (HE) subjects were recorded as they performed spiral drawing tasks on a touch screen device in their home environment settings. Several spatiotemporal features were extracted from the time series and used as inputs to machine learning methods. The methods were validated against ratings on animated spirals scored by four movement disorder specialists who visually assessed a set of kinematic features and the motor symptom. The ability of the method to discriminate between PD patients and HE subjects and the test-retest reliability of the computed scores were also evaluated. Computed scores correlated well with mean visual ratings of individual kinematic features. The best performing classifier (Multilayer Perceptron) classified the motor symptom (bradykinesia or dyskinesia) with an accuracy of 84% and area under the receiver operating characteristics curve of 0.86 in relation to visual classifications of the raters. In addition, the method provided high discriminating power when distinguishing between PD patients and HE subjects as well as had good test-retest reliability. This study demonstrated the potential of using digital spiral analysis for objective quantification of PD-specific and/or treatment-induced motor symptoms.

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Background: Plasmodium falciparum malaria is treated with 25 mg/kg of chloroquine (CQ) irrespective of age. Theoretically, CQ should be dosed according to body surface area (BSA). The effect of dosing CQ according to BSA has not been determined but doubling the dose per kg doubled the efficacy of CQ in children aged <15 years infected with P. falciparum carrying CQ resistance causing genes typical for Africa. The study aim was to determine the effect of age on CQ concentrations. Methods and Findings: Day 7 whole blood CQ concentrations were determined in 150 and 302 children treated with 25 and 50 mg/kg, respectively, in previously conducted clinical trials. CQ concentrations normalised for the dose taken in mg/kg of CQ decreased with decreasing age (p<0.001). CQ concentrations normalised for dose taken in mg/m(2) were unaffected by age. The median CQ concentration in children aged <2 years taking 50 mg/kg and in children aged 10-14 years taking 25 mg/kg were 825 (95% confidence interval [CI] 662-988) and 758 (95% CI 640-876) nmol/l, respectively (p = 0.67). The median CQ concentration in children aged 10-14 taking 50 mg/kg and children aged 0-2 taking 25 mg/kg were 1521 and 549 nmol/l. Adverse events were not age/concentration dependent. Conclusions: CQ is under-dosed in children and should ideally be dosed according to BSA. Children aged <2 years need approximately double the dose per kg to attain CQ concentrations found in children aged 10-14 years. Clinical trials assessing the efficacy of CQ in Africa are typically performed in children aged <5 years. Thus the efficacy of CQ is typically assessed in children in whom CQ is under dosed. Approximately 3 fold higher drug concentrations can probably be safely given to the youngest children. As CQ resistance is concentration dependent an alternative dosing of CQ may overcome resistance in Africa.

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Background: Although there is increasing recognition that quality of life (QOL) and health-related quality of life (HRQOL) are important outcome variables in clinical trials for children with cerebral palsy, there are substantial limitations in existing measures of QOL. This study identify themes of QOL for children with cerebral palsy and their parents to guide the development of a new condition-specific QOL scale. Methods: A qualitative study of parent and child views on QOL composition was conducted, using a grounded theory framework. Families participated in semistructured interviews on QOL until thematic saturation was reached (n = 28 families). Results: Overall, 13 themes emerged from the interviews: physical health, body pain and discomfort, daily living tasks, participation in regular physical and social activities, emotional well-being and self-esteem, interaction with the community, communication, family health, supportive physical environment, future QOL, provision of, and access to services, financial stability, and social well-being. Conclusions: Research with parents and children with cerebral palsy, representative of severity across the disease spectrum and socio-economic status, reinforced and expanded on the traditional themes that have underpinned QOL measurement development. This has implications not only for the development of a new QOL scale for children with cerebral palsy, but also for clinical interventions and community care management.

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Although clinical trials have shown that lifestyle modifications reduce the risk of type 2 diabetes, translating lessons from trials to primary care remains a challenge. The aim of the study was to evaluate efficacy and feasibility of primary care-based diabetes prevention model with modest resource requirements in rural Australia. Three hundred and eleven subjects with at least a moderate risk of type 2 diabetes participated in a combined dietary and physical activity intervention. Clinical measurements and fasting blood samples were taken at the baseline and after intervention. After 3 months intervention, total (change −3.5%, p < 0.001) and LDL cholesterol (−4.8%, p < 0.001) plasma levels as well as body mass index (−2.5%, p < 0.001), weight (−2.5%, p < 0.001), and waist (−1.6%, p < 0.001) and hip (−2.7%, p < 0.001) circumferences reduced significantly. A borderline reduction was found in triglyceride levels (−4.8%, p = 0.058) while no changes were observed in HDL cholesterol (+0.6%, p = 0.525), glucose (+0.06%, p = 0.386), or systolic (−0.98%, p = 0.095) or diastolic (−1.06%, p = 0.134) blood pressure levels. In conclusion, a lifestyle intervention improved health outcomes – especially obesity and blood lipids – in a population at high risk of developing type 2 diabetes. Our results suggest that the present model is effective and feasible to carry out in primary care settings.

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The oxazaphosphorines including cyclophosphamide (CPA, Cytoxan, or Neosar), ifosfamide (IFO, Ifex) and trofosfamide (Ixoten) represent an important group of therapeutic agents due to their substantial antitumor and immunomodulating activity. However, several intrinsic limitations have been uncounted during the clinical use of these oxazaphosphorines, including substantial pharmacokinetic variability, resistance and severe host toxicity. To circumvent these problems, new oxazaphosphorines derivatives have been designed and evaluated with an attempt to improve the selectivity and response with reduced host toxicity. These include mafosfamide (NSC 345842), glufosfamide (D19575, β-Dglucosylisophosphoramide mustard), S-(-)-bromofosfamide (CBM-11), NSC 612567 (aldophosphamide perhydrothiazine) and NSC 613060 (aldophosphamide thiazolidine). Mafosfamide is an oxazaphosphorine analog that is a chemically stable 4-thioethane sulfonic acid salt of 4-hydroxy-CPA. Glufosfamide is IFO derivative in which the isophosphoramide mustard, the alkylating metabolite of IFO, is glycosidically linked to a β-D-glucose molecule. Phase II studies of glufosfamide in the treatment of pancreatic cancer, non-small cell lung cancer (NCSLC), and recurrent glioblastoma multiform (GBM) have recently completed and Phase III trials are ongoing, while Phase I studies of intrathecal mafosfamide have recently completed for the treatment of meningeal malignancy secondary to leukemia, lymphoma, or solid tumors. S-(-)- bromofosfamide is a bromine-substituted IFO analog being evaluated in a few Phase I clinical trials. The synthesis and development of novel oxazaphosphorine analogs with favourable pharmacokinetic and pharmacodynamic properties still constitutes a great challenge for medicinal chemists and cancer pharmacologists.

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Evidence-informed practice is a key component of public health and the focus of much discussion, of which the nature of evidence and how it is best gathered and appraised has formed a large part. Prospective registration of trials is now a key component of rigour and quality in clinical research and has been supported at an international level through the WHO International Clinical Trials Registry Program. This paper discusses the scope and benefits of trial registration in clinical research, including greater transparency and reduced publication bias. It then considers the potential for a Prospective Public Health Intervention Studies Register specific to the needs of public health and aspects to be included in such a register. It is argued that this initiative has the potential to facilitate increased global cooperation and efficiency in the production of high quality evidence and ultimately in improved health outcomes for populations.

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Objective: The antioxidant activity of vitamin E is derived primarily from alpha-tocopherol (α-T) and gammatocopherol (γ-T). Results of epidemiological studies have demonstrated an inverse relationship between vitamin E intake and coronary disease. However, the results of clinical trials using α-T are equivocal. We determined the effect of 5 weeks of 100 mg/d or 200 mg/d γ-T supplementation on thrombotic markers such as platelet reactivity, lipid profile and the inflammation marker C-reactive protein (CRP). Methods and results: Fourteen healthy subjects consumed 100 mg/day while 13 consumed 200 mg/d of γ-T and 12 received placebo (soybean capsules with less than 5 mg/d γ-T) in a double-blinded parallel study design. Fasting pre and post dose blood samples were analysed. Blood γ-T concentrations increased significantly (p<0.05) relative to dose during the intervention period. Both groups receiving active ingredients showed significantly lower platelet activation after supplementation (p<0.05). Subjects consuming 100 mg/d γ-T had significantly decreased LDL cholesterol, platelet aggregation and mean platelet volume (MPV) (p<0.05). Little effect of γ-T was observed on other parameters. Conclusions: These data suggest that γ-T  supplementation may have a permissive role in decreasing the risk of
thrombotic events by improving lipid profile and reducing platelet activity.

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Background
Randomised controlled trials demonstrate a 60% reduction in type 2 diabetes incidence through lifestyle modification programmes. The aim of this study is to determine whether such programmes are feasible in primary health care.

Methods
An intervention study including 237 individuals 40–75 years of age with moderate or high risk of developing type 2 diabetes. A structured group programme with six 90 minute sessions delivered during an eight month period by trained nurses in Australian primary health care in 2004–2006. Main outcome measures taken at baseline, three, and 12 months included weight, height, waist circumference, fasting plasma glucose and lipids, plasma glucose two hours after oral glucose challenge, blood pressure, measures of psychological distress and general health outcomes. To test differences between baseline and follow-up, paired t-tests and Wilcoxon rank sum tests were performed.

Results
At twelve months participants' mean weight reduced by 2.52 kg (95% confidence interval 1.85 to 3.19) and waist circumference by 4.17 cm (3.48 to 4.87). Mean fasting glucose reduced by 0.14 mmol/l (0.07 to 0.20), plasma glucose two hours after oral glucose challenge by 0.58 mmol/l (0.36 to 0.79), total cholesterol by 0.29 mmol/l (0.18 to 0.40), low density lipoprotein cholesterol by 0.25 mmol/l (0.16 to 0.34), triglycerides by 0.15 mmol/l (0.05 to 0.24) and diastolic blood pressure by 2.14 mmHg (0.94 to 3.33). Significant improvements were also found in most psychological measures.

Conclusion
This study provides evidence that a type 2 diabetes prevention programme using lifestyle intervention is feasible in primary health care settings, with reductions in risk factors approaching those observed in clinical trials.

Trial Number
Current Controlled Trials ISRCTN38031372

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The Asia-Pacific region is undergoing a major change in both food and health patterns, with a connection between the two more than likely. Evidence for certain traditional Asia-Pacific foods as protective agents against chronic non-communicable disease and cardiovascular disease (CVD), in particular, is growing at a time when their usage diminishes. The nature of the evidence to establish relevant Asia-Pacific food-health linkages will include randomised placebo-controlled clinical trials, but is much more extensive and meaningful. Okinawans have probably achieved one of the most successful food cultures from a health point of view and serve as a reference point for the Asia-Pacific region. The expert working party has produced, in November 2000, the 'Okinawan Recommendations on Nutrition and CVD in the Asia-Pacific region'.

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Recently, two seemingly divergent approaches have emerged in outcomes-based medical research. Proponents of evidence-based medicine (EBM) argue that the most effective treatments will be found by adopting a hierarchical approach that gives pre-eminence to randomized controlled clinical trials, where these are available. Proponents of participatory medical research argue that research undertaken with consumers and other partners in the community will produce the best outcomes. While one approach marginalizes consumer experience the other approach draws consumers into it. EBM assumes a high level of consensus in a scientific community, while participatory medical research relies on co-opting consumer experience. This paper indicates that each approach involves a particular view of social structure in science. The paper uses theories of social relations among scientists for the purpose of critically assessing EBM and the participatory model.

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Background
Obesity prevention is an international public health priority. The prevalence of obesity and overweight is increasing in child populations throughout the world, impacting on short and long-term health. Obesity prevention strategies for children can change behaviour but efficacy in terms of preventing obesity remains poorly understood.

Objectives
To assess the effectiveness of interventions designed to prevent obesity in childhood through diet, physical activity and/or lifestyle and social support.

Search strategy
MEDLINE, PsycINFO, EMBASE, CINAHL and CENTRAL were searched from 1990 to February 2005. Non-English language papers were included and experts contacted.

Selection criteria
Randomised controlled trials and controlled clinical trials with minimum duration twelve weeks.

Data collection and analysis
Two reviewers independently extracted data and assessed study quality.

Main results
Twenty-two studies were included; ten long-term (at least 12 months) and twelve short-term (12 weeks to 12 months). Nineteen were school/preschool-based interventions, one was a community-based intervention targeting low-income families, and two were family-based interventions targeting non-obese children of obese or overweight parents.

Six of the ten long-term studies combined dietary education and physical activity interventions; five resulted in no difference in overweight status between groups and one resulted in improvements for girls receiving the intervention, but not boys. Two studies focused on physical activity alone. Of these, a multi-media approach appeared to be effective in preventing obesity. Two studies focused on nutrition education alone, but neither were effective in preventing obesity.

Four of the twelve short-term studies focused on interventions to increase physical activity levels, and two of these studies resulted in minor reductions in overweight status in favour of the intervention. The other eight studies combined advice on diet and physical activity, but none had a significant impact.

The studies were heterogeneous in terms of study design, quality, target population, theoretical underpinning, and outcome measures, making it impossible to combine study findings using statistical methods. There was an absence of cost-effectiveness data.

Authors' conclusions
The majority of studies were short-term. Studies that focused on combining dietary and physical activity approaches did not significantly improve BMI, but some studies that focused on dietary or physical activity approaches showed a small but positive impact on BMI status. Nearly all studies included resulted in some improvement in diet or physical activity. Appropriateness of development, design, duration and intensity of interventions to prevent obesity in childhood needs to be reconsidered alongside comprehensive reporting of the intervention scope and process.

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Background: Despite the fact that it is largely preventable, dental caries (decay) remains one of the most common chronic diseases of early childhood. Dental decay in young children frequently leads to pain and infection necessitating hospitalization for dental extractions under general anaesthesia. Dental problems in early childhood have been shown to be predictive of not only future dental problems but also on growth and cognitive development by interfering with comfort nutrition, concentration and school participation. Objective: To review the current evidence base in relation to the aetiology and prevention of dental caries in preschool-aged children. Methods: A search of MEDLINE, CINALH and Cochrane electronic databases was conducted using a search strategy which restricted the search to randomized controlled trials, meta-analyses, clinical trials, systematic reviews and other quasi-experimental designs. The retrieved studies were then limited to articles including children aged 5 years and under and published in English. The evidence of effectiveness was then summarized by the authors. Conclusions: The review highlighted the complex aetiology of early childhood caries (ECC). Contemporary evidence suggests that potentially effective interventions should occur in the first 2 years of a child's life. Dental attendance before the age of 2 years is uncommon; however, contact with other health professionals is high. Primary care providers who have contact with children well before the age of the first dental visit may be well placed to offer anticipatory advice to reduce the incidence of ECC.

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Depression is associated with glucocorticoid hypersecretion, due to dysfunction of the hypothalamo-pituitary-adrenocorticol axis (HPA-axis). Because excess glucocorticoids are associated with depressive-like features in humans, glucocorticoid receptor antagonists are currently being tested for antidepressant efficacy in clinical trials. In the current study the hypothesis that mifepristone (RU486), a glucocorticoid receptor antagonist, would decrease the neuroendocrine and central HPA-axis responses to an acute stressor and attentuate depressive like behavior in an animal model of behavioral helplessness (forced swim test) was tested. Adult male rats were treated with 10 mglkg RU486 (subcutaneous) for five days and then exposed to a IO-minute forced swim test (FST), conducted in Plexiglas cylinders. FST sessions were videotaped for later analysis of behavioral immobility. Plasma ACTH and corticosterone CORT were measured at 15min and 90min after FST cessation. Animals were perfused and brains were collected for immunocytochemical assessment of c-Fos expression in the medial prefrontal cortex (mPFC), a brain region implicated in both depression and central control of the HPA axis. RU486 significantly decreased peak ACTH and CORT concentrations following FST exposure. In addition, glucocorticoid negative feedback was at1enuated in RU486-treated animals exposed to the FST. Exposure to FST alone induced c-FOS expression in the mPFC, as measured by the number of c-Fos positive neurons. Treatment with RU486 significantly increased the number of rnPFC c-Fos positive cell following FST exposure. The behavioral data obtained from FST paradigm, demonstrated that RU486 decreased immobility in the FST illustrating the potential efficacy of this drug as an antidepressant. Collectively these data suggest that RU486 dampens HPA-axis responses to stress, possibly by enhancing the excitability of stress-inhibitory neurons in the mPFC. This is particularly exciting, given the fact that this neural region is associated with decreased neural activity during depression in humans.