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Large Clinical Trials (large + clinical_trials)
Selected AbstractsThe renin,angiotensin system and the long-term complications of diabetes: pathophysiological and therapeutic considerationsDIABETIC MEDICINE, Issue 8 2003R. E. Gilbert Abstract The relationship between the renin,angiotensin system (RAS) and the progression of diabetic renal disease has been a major focus of investigation over the past 20 years. More recently, experimental and clinical studies have also suggested that the RAS may have a pathogenetic role at other sites of micro- and macrovascular injury in diabetes. Complementing major advances into the understanding of the local, as distinct from the systemic RAS, a number of large clinical trials have examined whether blockade of the RAS might provide protection from the long-term complications of diabetes, beyond that due to blood pressure reduction alone. While some controversy remains, these studies have, in general, suggested that angiotensin converting enzyme (ACE) inhibition and more recently, angiotensin receptor blockade reduce the development and progression of diabetic nephropathy, cardiovascular disease and possibly retinopathy. This review will focus on recent developments in our understanding of the tissue-based RAS and its role in end-organ injury in diabetes, the results of recent clinical trials and newer strategies for the pharmacological manipulation of the RAS. [source] An expanded role for dietitians in maximising retention in nutrition and lifestyle intervention trials: implications for clinical practiceJOURNAL OF HUMAN NUTRITION & DIETETICS, Issue 4 2010L. M. Delahanty Abstract The demand for clinical trials targeting lifestyle intervention has increased as a result of the escalation in obesity, diabetes mellitus and cardiovascular disease. Little is published about the strategies that dietitians have used to successfully screen potential study volunteers, implement interventions and maximise adherence and retention in large multicentre National Institutes of Health funded nutrition and lifestyle intervention clinical trials. This paper discusses an expanded role for the contributions of dietitians as members of an interdisciplinary team based on research experiences in the Diabetes Control and Complications Trial, Diabetes Prevention Program and Look AHEAD (Action for Health in Diabetes). Many of the strategies and insights discussed are also relevant to effective clinical practice. Dietitians need to broaden their scope of practice so that they are integrated proactively into the screening and intervention phases of large clinical trials to maximise retention and adherence to assigned nutrition, lifestyle and behavioural interventions. The skills of dietitians are a unique fit for this work and it is important that investigators and project managers consider including them in both the screening and intervention phases of such clinical trials to maximise retention results. [source] Design and Implementation of a Multicenter Trial of Vitamin E in Aging Individuals with Down SyndromeJOURNAL OF POLICY AND PRACTICE IN INTELLECTUAL DISABILITIES, Issue 2 2005Paul S. Aisen Abstract, Older individuals with Down syndrome have an extremely high risk of Alzheimer's disease (AD). Advances in understanding the pathophysiology of AD, and the development of effective therapies for individuals with sporadic AD, have raised the possibility that aging Down syndrome individuals may benefit from therapy directed against AD. As no prior large clinical trials had been conducted with this population, the authors launched "A Multicenter Trial of Vitamin E in Aging Individuals with Down Syndrome." The authors describe how they assembled an international group of investigators to develop the infrastructure and methodology for studying the efficacy of therapeutic interventions aimed at slowing the process of AD in Down syndrome. The process of designing and implementing the trial drew together clinical scientists and clinicians from two distinct but overlapping areas: researchers in the areas of Down syndrome and AD therapeutics. The authors review the issues considered and decisions made regarding various aspects of the trial design. [source] Acupuncture for Alcohol Dependence: A Systematic ReviewALCOHOLISM, Issue 8 2009Seung-Hun Cho Background:, Acupuncture has been used in the treatment of substance-related disorders for the past 30 years. However, a systematic review to assess the effect of various types of acupuncture for alcohol dependence has not yet been performed. The present systematic review assessed the results of randomized controlled trials (RCTs). Methods:, Nineteen electronic databases, including English, Korean, Japanese, and Chinese databases, were systematically searched for RCTs of acupuncture for alcohol dependence up to June 2008 with no language restrictions. The methodological qualities of eligible studies were assessed using the criteria described in the Cochrane Handbook. Results:, Eleven studies, which comprised a total of 1,110 individual cases, were systematically reviewed. Only 2 of 11 trials reported satisfactorily all quality criteria. Four trials comparing acupuncture treatment and sham treatments reported data for alcohol craving. Three studies reported that there were no significant differences. Among 4 trials comparing acupuncture and no acupuncture with conventional therapies, 3 reported significant reductions. No differences between acupuncture and sham treatments were found for completion rates (Risk Ratio = 1.07, 95% confidence interval, CI = 0.91 to 1.25) or acupuncture and no acupuncture (Risk Ratio = 1.15, 95% CI = 0.79 to 1.67). Only 3 RCTs reported acupuncture-related adverse events, which were mostly minimal. Conclusions:, The results of the included studies were equivocal, and the poor methodological quality and the limited number of the trials do not allow any conclusion about the efficacy of acupuncture for treatment of alcohol dependence. More research and well-designed, rigorous, and large clinical trials are necessary to address these issues. [source] Blood cultures for febrile patients in the acute care setting: Too quick on the draw?JOURNAL OF THE AMERICAN ACADEMY OF NURSE PRACTITIONERS, Issue 11 2008ACNP-BC, Barbara K. Chesnutt MSN Abstract Purpose: To review the fever literature and determine how 38.3°C was deemed the optimal fever threshold that predicts bacteremia. Data sources: PubMed, MEDLINE, Cochrane database, and the Cumulative Index to Nursing and Allied Health. Conclusions: A temperature of 38.3°C has come to be the threshold value that typically triggers diagnostic fever evaluation for bacteremia in hospitalized patients. Studies that define predictors of bacteremia provide conflicting results, and most bacteremia predictor models have not been externally validated. Therefore, current fever guidelines are based on consensus opinion rather than large clinical trials identifying a specific threshold with high sensitivity and a high negative predictive value. Implications for practice: The use of a single temperature threshold of 38.3°C for the prediction of bacteremia is not sufficient in all patients. Additional factors should be considered, including patient population, supporting clinical signs and symptoms, and the patient's medical history. [source] Are delayed-start design trials to show neuroprotection in Parkinson's disease fundamentally flawed?MOVEMENT DISORDERS, Issue 6 2008Carl E. Clarke BSc, FRCP Abstract Considerable effort has gone into preclinical neuroprotection research in Parkinson's disease (PD) and several large clinical trials have been mounted, but no agent has been conclusively shown to be protective. The latest innovation in PD neuroprotection trial design is the delayed-start design trial. If patients with early PD do better after 12 to 18 months of immediate drug therapy compared to those in whom it is delayed for 6 to 9 months, this is attributed to a neuroprotective effect. However, delayed-start design trials may be fundamentally flawed. It has been suggested that physiological mechanisms compensating for the loss of dopaminergic neurones in early PD may be deleterious and that immediate treatment may prevent such mechanisms and thereby be neuroprotective. If this hypothesis is correct, any drug with a symptomatic effect will be neuroprotective in early PD and delayed-start design trials will show this generic effect, not a neuroprotective effect specific to the drug. Delayed-start design trials require patients to potentially stay untreated for 6 to 9 months. This may lead to the selection of slowly progressive types of PD, such as that in younger patients and those with tremor-dominant disease, so the results may not be generalizable to the majority of patients. Delayed-start design trials are powered to find small differences in total UPDRS score which may not be clinically significant; larger and longer placebo-controlled trials are required to confirm the clinical significance of their findings. These arguments add to the growing tide of opinion for a fundamental rethink of our policy toward neuroprotection research in PD. © 2008 Movement Disorder Society [source] Population screening and early detection of ovarian cancer in asymptomatic womenAUSTRALIAN AND NEW ZEALAND JOURNAL OF OBSTETRICS AND GYNAECOLOGY, Issue 5 2009Anne E. NELSON The National Breast and Ovarian Cancer Centre position statement: ,Population screening and early detection of ovarian cancer in asymptomatic women', was developed and agreed following a Forum in February 2009 attended by key Australian stakeholders. The final position statement and supporting background information have been endorsed by key Australian colleges and agencies. Position statement on population screening and early detection of ovarian cancer in asymptomatic women 1There is currently no evidence that any test, including pelvic examination, CA125 or other biomarkers, ultrasound (including transvaginal ultrasound), or combination of tests, results in reduced mortality from ovarian cancer. 2There is no evidence to support the use of any test, including pelvic examination, CA125 or other biomarkers, ultrasound (including transvaginal ultrasound), or combination of tests, for routine population-based screening for ovarian cancer. 3Further validation in large clinical trials is required before current or new biomarkers could be recommended for routine use in a population screening setting. [source] Epidemiological and clinical trials evidence about a preventive role for statins in Alzheimer's diseaseACTA NEUROLOGICA SCANDINAVICA, Issue 2006K. Rockwood This paper reviews epidemiological and clinical trials data about whether statin use reduces the risk of Alzheimer's disease (AD). The available information has come in three waves. The initial, mostly cross-sectional observational reports suggested that statins might prevent dementia. Next, two large clinical trials with cognitive add-on studies showed no benefit and neither did the third wave, again with observational studies. The latter were mostly longitudinal, and were critical of the first studies for not adequately addressing confounding by indication (i.e. that patients with dementia would be denied statins). Most recently, new data from the Canadian Study of Health and Aging have produced a mixed result. While methodological considerations are clearly important in understanding why the reports are so variable, there might also be merit in differentiating between statins, based on their presumed , and variable , mechanisms of action in dementia prevention, before concluding that the initial reports are entirely artefactual. Still, the first reports appear to have overestimated the extent of protection, so that unless there are important effects achievable with specific statins, a more than a modest role for statins in preventing AD seems unlikely. [source] 4352: Retrobulber imag,ng in glaucoma w,th d,ffus,on tensor MRI/opt,c tractography and fMRI: structural and funct,onal analys,sACTA OPHTHALMOLOGICA, Issue 2010KN ENGIN Purpose Evidences today proves that, glaucomateus damage proceeds from retinal ganglion cells to brain. The purpose of this study is to demonstrate the structural and functional eye-brain connection in glaucoma, to develop favourable clinical methods for both glaucoma follow ups and large clinical trials, and finally, to establish a reference for further studies regarding pathogenesis, evaluation and treatment of glaucoma. Methods Four glaucoma cases with symetrical (n=2) and asymetrical (n=2) involvement and 1 healthy subject are included in this study. Glaucoma analysis with optic coherens tomography (OCT) and central visual field (CVF) results of the subjects were recorded. By using diffusion-tensor magnetic resonance imaging (DT-MRI) technique, 3D-T1 weighted images of the optic nerves and optic tracts were taken with optic tractography (OT). Then DT-MRI parameters obtained from each patient were compared with the fellow eye and the healthy subject. Retinotopic Organizations (RO) of primary visual cortexes were produced from functional magnetic resonance imaging (fMRI) images and BOLD signals were evaluated with reciprocal CVF defects. All images were taken with 1,5T MRI system. Results In DT-MRI analysis, optic nerve volume, FA were found to be decreased in the eyes with severe RNFL loss. Optic nerve and tract deformation were showed with both OT and B0 coronal plane images. Lower bold signals were detected in the eyes of asymetric patients with severe glaucoma and in quadrants with large CVF defects. Conclusion Strategies concerning beyond optic nerve head are needed in glaucoma. Structural and functional analysis can be made by taken together the OCT and DT-MRI findings and CVF and fMRI findings, respectively. [source] | ||||||||||