There are about 25435 clinical studies being (or have been) conducted in United Kingdom. The country of the clinical trial is determined by the location of where the clinical research is being studied. Most studies are often held in multiple locations & countries.
The purpose of this study will be to determine if blockade of endothelin 1 signalling via endothelin receptor A using ambrisentan or dual blockade (A&B) via bosentan can provide protection against methacholine induced bronchoconstriction in asthma.
The purpose of this study is to evaluate the visual performance of a trifocal intraocular lens at distance, near and intermediate viewing, by way of visual acuity measurement, contrast sensitivity. Patient satisfaction and quality of vision will also be assessed by way of a questionnaire.
Bowel cancer is a common disorder in the UK. Most cancers happen when a type of polyp, called an adenoma, becomes cancerous. Polyps are growths in the large bowel that can be cancerous, non-cancerous, or pre-cancerous (adenoma). Polyps are most commonly detected during colonoscopy (camera test of the lower bowel). The removal of adenomas has been shown to reduce the subsequent risk of bowel cancer. Current practice is that all polyps are removed or biopsied to allow a laboratory diagnosis (histology). This is important as it influences if and when patients require follow-up colonoscopies, known as the surveillance interval. Patients with only non-cancerous polyps do not need surveillance. A new blue light technology, called narrow band imaging (NBI), used during colonoscopy can help colonoscopists (doctor or nurse performing the procedure)differentiate between polyp types during colonoscopy. NBI is currently available in a large number of UK endoscopy units however is variably used. Studies from 'expert' centres have demonstrated that NBI allows accurate optical diagnosis of colonic polyps. Benefits of optical diagnosis include avoiding removal of non-cancerous polyps and an immediate (on the day) diagnosis for the patient including the surveillance interval. The primary aim of this study is to evaluate the accuracy with which colonoscopists assess the required surveillance interval using optical diagnosis when compared with histology in non-expert centres. The investigators will invite 2500 patients, who have been referred for colonoscopy, to participate. Patients will undergo a routine colonoscopy the only addition being the use of NBI during the procedure. Colonoscopists will provide an optical diagnosis at the time of colonoscopy in addition to polyp removal or biopsy. The investigators will compare surveillance intervals provided using optical diagnosis with the diagnosis from histology and thereby the accuracy with which colonoscopists can use the technology. The investigators will also calculate the cost savings to the NHS.
Optical coherence tomography (OCT) is an imaging technique which shows the internal structure of living tissue (in vivo). It is safe, quick and painless to perform, and does not damage the tissue in any way. Recent advances in the technology mean that it can now be used to take images of the internal structure of the skin. This is useful because certain conditions, such as skin cancers, alter this structure. At present a suspected skin cancer is identified by taking a sample (a biopsy) which is analysed under the microscope to confirm the diagnosis. The cancer is then excised including a margin of apparently healthy-looking skin around it to ensure that the entirety of the tumour is removed. The excised tumour is then analysed again under a microscope to confirm that it was indeed completely removed (histology), after which a further operation is required to repair the defect. The purpose of this study is to evaluate OCT imaging of a particular type of skin cancer called a basal cell carcinoma (BCC), and in particular BCCs affecting the skin around the eyes (periocular). The study will compare the ability of OCT to define the margin of the BCC with the current 'gold standard' of histology. OCT could potentially improve the investigators ability to define the margins of the tumour before surgery and become a guide for minimally invasive surgery. The preservation of healthy tissue represents a priority, particularly in the area of the skin surrounding the eye.
Depression has a high occurrence and causes other problems in older people, two thirds of these patients will not have a lessening in their condition from routine treatment medication. About half have a form of depression known as 'vascular depression'. Augmentation, the addition to, antidepressant treatment with a vascular type of treatment (such as a group of medications called Calcium Channel Blocker including the medication called amlodipine) may be effective in this group of patients but previously published studies have been from highly selected specific patient groups. The investigators would like to find out if giving amlodipine medication to people with late life non-responding vascular depression would be acceptable to this patient group. The investigators would also like to know how they feel while having the treatment and whether this provides a measurable benefit for those patients and whether those benefits are relevant to the patients. The investigators would also like to find out the information the investigators need to plan and prepare for a larger version of this study.
Cardiac rehabilitation is the ideal comprehensive intervention for patients with chronic heart failure (CHF), since it addresses the complex interplay of medical, psychological and behavioural factors facing these individuals. Structured exercise training within a cardiac rehabilitation programme is firmly recommended for these patients. However, it is questionable whether patients are achieving an adequate dose of exercise to provide optimal benefits. The essential components for setting optimal training include the appropriate mode, duration, frequency and intensity of exercise. UK surveys of cardiac rehabilitation describe the frequency and duration of training, but here is scant information on exercise intensity. However, it is apparent that randomised controlled trials of exercise training use doses more than 4 times greater than in UK current practice. The Eastbourne Exercise Cardiology Research Group has demonstrated that although patients benefit from improved quality of life and submaximal fitness after a hospital outpatient cardiac rehabilitation programme, they do not achieve the increases in important prognostic indicators reported by the majority of exercise training trials. The critical factor in terms of eliciting a sufficient training effect while minimising risk is the intensity of the exercise performed. It is now widely accepted that the traditional methods of using fixed percentages of maximal heart rate or oxygen uptake to set exercise intensity include serious errors. The European Society of Cardiology recommends that cardiopulmonary exercise testing should be used to provide an objective evaluation of the metabolic demand of exercise. This allows physiologically meaningful reference points to be established for aerobic exercise prescription and is the solution to defining safe and effective training intensities. The next step is to determine whether this information can be transferred to a practical cardiac rehabilitation environment to set and monitor exercise intensity
This is a non-commercial study to explore the use of Heliox21 in a new patient cohort. The fundamental aim is to assess the therapeutic benefits of Heliox21 and practicalities of gas delivery in patients who require non-invasive ventilatory support following extubation on the Intensive Care Unit. Thus, the investigators aim to extend our knowledge of the potential role for Heliox21 in the post-extubation environment of the Intensive Care Unit. The purpose of this study is to answer a specific, clinically relevant question. That is whether Heliox21 helps to reduce the effort of breathing in the period following withdrawal of mechanically assisted ventilation in patients on the intensive care unit.
The principal aim of this study is to establish if a polymorphism in a gene important for innate immunity to fungi represents a significant risk factor for the development of Candida colonisation and subsequent invasive candidosis in critically ill patients. Incorporation of a screening programme onto a risk-based algorithm for critical care patients would allow more effective targeting of molecular diagnostic tests, anti-fungal prophylaxis and targeted treatment. Sequential critical care patients will be screened for gene polymorphisms and undergo regular screening for Candida colonization.
The investigators aim to measure the blood levels of certain metals in a group of patients all of whom have had a ceramic on metal total hip replacement. This new bearing surface (joint) is relatively new and the investigators are currently following up the largest cohort in the world. Clinical results are currently excellent at 2 years in all patients, however the investigators are mindful of the lessons learned from the high failure rate of several designs of metal on metal hip replacements as well as several in vitro reports and one in vivo case report of elevated metal levels in this particular implant. The investigators feel it is important to measure the metal ion levels in our group to ascertain and compare these with reference standards. Once performed the investigators can relate ion levels to function and x ray changes and provide useful longterm data to the patients and the wider medical community as to whether this bearing surface is safe in the long term or whether it's use should be abandoned. This is useful as there are numerous groups implanting this device in the UK and in addition it has just been awarded FDA approval in the USA - its use is likely to flourish.
The ongoing success of transplantation is largely due to the development of drugs to stop the patient's body from rejecting the new organ. In addition to steroids, two main types of drug are used to suppress the immune system following heart transplantation: calcineurin inhibitors (Ciclosporin-A or Tacrolimus) and mycophenolate. However, different patients respond in different ways to these drugs, with the same dose leading to different levels of the drug in the blood. This varies due to genetic and other factors such as age, kidney function and the use of other drugs. Therefore, the levels of immunosuppressive drugs in the blood are routinely measured and the dose adjusted accordingly. However, some patients still experience episodes of rejection despite apparently acceptable levels. In this study, the investigators will measure levels of the drugs (in the blood, in a type of white blood cell called T-cells and in the heart muscle) and the effectiveness of the drugs on T-cells. The investigators will compare these levels with patient genetic factors and the amount of rejection measured on heart biopsies. This will enable us to better understand how the blood and tissue levels of these drugs change with genetic and other factors in order to optimise immunosuppressive therapy and further improve outcomes from heart transplantation.