6 resultados para Clinical study

em Aston University Research Archive


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DUE TO COPYRIGHT RESTRICTIONS ONLY AVAILABLE FOR CONSULTATION AT ASTON UNIVERSITY LIBRARY AND INFORMATION SERVICES WITH PRIOR ARRANGEMENT

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The limbal vascular response to extended contact lens wear was examined in a group comparative study initially intended to last eighteen months. After six months all patients wearing contact lenses had presented with micro-epithelial cysts. This unanticipated occurrence of the micro-epithelial-cysts necessitated termination of the study, and limited the quantity of data collected. However, sufficient results were available to allow a limited description of •the vascular response to this form of contact lens wear. Interpretations of the date collected ore discussed in relation to suggested vasostimulating factors in the cornea. The micro-epithelial cysts observed after extended wear were classified and their rate of recovery recorded. A further clinical study was undertaken to observe cysts in both contact lens - and non contact lens-wearing eyes. Cysts were observed in every category of patient, although the characteristic patterns varied. These observations of micro-epithelial cysts are discussed with respect to the aetiopathogeneses of corneal epithelial cystic disorders. Subsequently, attempts were made to induce cysts in rabbit corneae by extended contact lens wear. Clinical observations revealed cyst-like appearances. Histological sections did not contain cysts but did exhibit signs characteristic •of cystic disorders of the corneal epithelium. In general, the results from the study indicate that extended wear is subjectively acceptable to contact lens wearers. However, the objective findings of significant vascular changes, micro-epithelial cysts and cases of acute red eye response cast considerable doubt on the recommendation of extended wear contact lenses for purely cosmetic applications.

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A clinical study was undertaken to compare the surface microbial contamination associated with pens constructed of either a copper alloy or stainless steel used by nurses on intensive care units. A significantly lower level of microbial contamination was found on the copper alloy pens. Copyright © 2011 by the Association for Professionals in Infection Control and Epidemiology, Inc. Published by Elsevier Inc. All rights reserved.

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Contact lenses have become a popular method of vision correction for millions of people globally. As with all devices designed for use within the body, interactions occur between the implanted material and the surrounding biological fluid. A common complaint of lens wearers is that they often experience symptoms of dry eye whilst wearing lenses. This sensation is often heightened towards the end of the day. Through the course of this study, various analytical techniques have been utilised including one dimensional electrophoresis and Western Blotting to study the protein profiles of tear samples. By studying the tears of non-contact lens wearers, it was possible to analyse what could be considered normal, healthy, individuals. A clinical study was also undertaken which followed a population of individuals from the neophyte stage to one whereby they were accustomed lens wearers. Tears were monitored at regular intervals throughout the course of this study and worn contact lenses were also analysed for proteins that had been deposited both on and within the lens. Contact lenses disrupt the tear film in a physical manner by their very presence. They are also thought to cause the normal protein profile to deviate from what would be considered normal. The tear film deposits proteins and lipids onto and within the lens. The lens may therefore be depriving the tear film of certain necessary components. The ultimate aim of this thesis was to discover how, and to what extent, lenses affected tear proteins and if there were any proteins in the tear fluid that had the potential to be used as biochemical markers. Should this be achievable it may be possible to identify those individuals who were more likely to become intolerant lens wearers. This study followed the changes taking place to the tear film as an effect of wearing contact lenses. Twenty-eight patients wore two different types of silicone hydrogel lenses in both a daily wear and a continuous wear regime. The tear protein profiles of the lens-wearers were compared with a control group of non-lens wearing individuals. The considerable amount of data that was generated enabled the clearly observable changes to the four main tear proteins to be monitored.

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The work present in this thesis was aimed at assessing the efficacy of lithium in the acute treatment of mania and for the prophylaxis of bipolar disorder, and investigating the value of plasma haloperidol concentration for predicting response to treatment in schizophrenia. The pharmacogenetics of psychotropic drugs is critically appraised to provide insights into interindividual variability in response to pharmacotherapy, In clinical trials of acute mania, a number of measures have been used to assess the severity of illness and its response to treatment. Rating instruments need to be validated in order for a clinical study to provide reliable and meaningful estimates of treatment effects, Eight symptom-rating scales were identified and critically assessed, The Mania Rating Scale (MRS) was the most commonly used for assessing treatment response, The advantage of the MRS is that there is a relatively extensive database of studies based on it and this will no doubt ensure that it remains a gold standard for the foreseeable future. Other useful rating scales are available for measuring mania but further cross-validation and validation against clinically meaningful global changes are required. A total of 658 patients from 12 trials were included in an evaluation of the efficacy of lithium in the treatment of acute mania. Treatment periods ranged from 3 to 4 weeks. Efficacy was estimated using (i) the differences in the reduction in mania severity scores, and (ii) the ratio and difference in improvement response rates. The response rate ratio for lithium against placebo was 1.95 (95% CI 1.17 to 3.23). The mean number needed to treat was 5 (95% CI 3 to 20). Patients were twice as likely to obtain remission with lithium than with chlorpromazine (rate ratio = 1.96, 95% CI 1.02 to 3.77). The mean number needed to treat (NNT) was 4 (95% CI 3 to 9). Neither carbamazepine nor valproate was more effective than lithium. The response rate ratios were 1.01 (95% CI 0.54 to 1.88) for lithium compared to carbarnazepine and 1.22 (95% CI 0.91 to 1.64) for lithium against valproate. Haloperidol was no better than lithium on the basis of improvement based on assessment of global severity. The differences in effects between lithium and risperidone were -2.79 (95% CI -4.22 to -1.36) in favour of risperidone with respect to symptom severity improvement and -0.76 (95% CI -1.11 to -0,41) on the basis of reduction in global severity of disease. Symptom and global severity was at least as well controlIed with lithium as with verapamil. Lithium caused more side-effects than placebo and verapamil, but no more than carbamazepine or valproate. A total of 554 patients from 13 trials were included in the statistical analysis of lithium's efficacy in the prophylaxis of bipolar disorder. The mean follow-up period was 5-34 months. The relapse risk ratio for lithium versus placebo was 0.47 (95% CI 0.26 to 0.86) and the NNT was 3 (95% CI 2 to 7). The relapse risk ratio for lithium versus imipramine was 0.62 (95% CI 0.46 to 0.84) and the NNT was 4 (951% Cl 3 to 7), The combination of lithium and imipramine was no more effective than lithium alone. The risk of relapse was greater with lithium alone than with the lithium-divalproate combination. A risk difference of 0.60 (95% CI 0.21 to 0.99) and an NNT of 2 (95% CI 1 to 5) were obtained. Lithium was as effective as carbamazepine. Based on individual data concerning plasma haloperidol concentration and percent improvement in psychotic symptoms, our results suggest an acceptable concentration range of 11.20-30.30 ng/mL A minimum of 2 weeks should be allowed before evaluating therapeutic response. Monitoring of drug plasma levels seems not to be necessary unless behavioural toxicity or noncompliance is suspected. Pharmacokinetics and pharmacodynamics, which are mainly determined by genetic factors, contribute to interindividual and interethnic variations in clinical response to drugs. These variations are primarily due to differences in drug metabolism. Variability in pharmacokinetics of a number of drugs is associated with oxidation polymorphism. Debrisoquine/sparteine hydroxylase (CYP2D6) and the S-mephenytoin hydroxylase (CYP2C19) are polymorphic P450 enzymes with particular importance in psychopharmacotherapy. The enzymes are responsible for the metabolism of many commonly used antipsychotic and antidepressant drugs. The incidence of poor metabolisers of debrisoquine and S-mephenytoin varies widely among populations. Ethnic variations in polymorphic isoenzymes may, at least in part, explain ethnic differences in response to pharmacotherapy of antipsychotics and antidepressant drugs.