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Affiliation(s)
- E D Acheson
- Nuffield Department of Clinical Medicine, Oxford University
| | - J G Evans
- Nuffield Department of Clinical Medicine, Oxford University
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Abstract
BACKGROUND Alzheimer's disease is the commonest cause of dementia affecting older people. One of the therapeutic strategies aimed at ameliorating the clinical manifestations of Alzheimer's disease is to enhance cholinergic neurotransmission in the brain by the use of cholinesterase inhibitors to delay the breakdown of acetylcholine released into synaptic clefts. Tacrine, the first of the cholinesterase inhibitors to undergo extensive trials for this purpose, was associated with significant adverse effects including hepatotoxicity. Other cholinesterase inhibitors, including rivastigmine, with superior properties in terms of specificity of action and lower risk of adverse effects have since been introduced. Rivastigmine has received approval for use in 60 countries including all member states of the European Union and the USA. OBJECTIVES To determine the clinical efficacy and safety of rivastigmine for patients with dementia of Alzheimer's type. SEARCH METHODS We searched ALOIS, the Cochrane Dementia and Cognitive Improvement Group Specialized Register, on 2 March 2015 using the terms: Rivastigmine OR exelon OR ENA OR "SDZ ENA 713". ALOIS contains records of clinical trials identified from monthly searches of a number of major healthcare databases (Cochrane Library, MEDLINE, EMBASE, PsycINFO, CINAHL, LILACS), numerous trial registries and grey literature sources. SELECTION CRITERIA We included all unconfounded, double-blind, randomised, controlled trials in which treatment with rivastigmine was administered to patients with dementia of the Alzheimer's type for 12 weeks or more and its effects compared with those of placebo in a parallel group of patients, or where two formulations of rivastigmine were compared. DATA COLLECTION AND ANALYSIS One review author (JSB) applied the study selection criteria, assessed the quality of studies and extracted data. MAIN RESULTS A total of 13 trials met the inclusion criteria of the review. The trials had a duration of between 12 and 52 weeks. The older trials tested a capsule form with a dose of up to 12 mg/day. Trials reported since 2007 have tested continuous dose transdermal patch formulations delivering 4.6, 9.5 and 17.7 mg/day.Our main analysis compared the safety and efficacy of rivastigmine 6 to 12 mg/day orally or 9.5 mg/day transdermally with placebo.Seven trials contributed data from 3450 patients to this analysis. Data from another two studies were not included because of a lack of information and methodological concerns. All the included trials were multicentre trials and recruited patients with mild to moderate Alzheimer's disease with a mean age of about 75 years. All had low risk of bias for randomisation and allocation but the risk of bias due to attrition was unclear in four studies, low in one study and high in two studies.After 26 weeks of treatment rivastigmine compared to placebo was associated with better outcomes for cognitive function measured with the Alzheimer's Disease Assessment Scale-Cognitive (ADAS-Cog) score (mean difference (MD) -1.79; 95% confidence interval (CI) -2.21 to -1.37, n = 3232, 6 studies) and the Mini-Mental State Examination (MMSE) score (MD 0.74; 95% CI 0.52 to 0.97, n = 3205, 6 studies), activities of daily living (SMD 0.20; 95% CI 0.13 to 0.27, n = 3230, 6 studies) and clinician rated global impression of changes, with a smaller proportion of patients treated with rivastigmine experiencing no change or a deterioration (OR 0.68; 95% CI 0.58 to 0.80, n = 3338, 7 studies).Three studies reported behavioural change, and there were no differences compared to placebo (standardised mean difference (SMD) -0.04; 95% CI -0.14 to 0.06, n = 1529, 3 studies). Only one study measured the impact on caregivers using the Neuropsychiatric Inventory-Caregiver Distress (NPI-D) scale and this found no difference between the groups (MD 0.10; 95% CI -0.91 to 1.11, n = 529, 1 study). Overall, participants who received rivastigmine were about twice as likely to withdraw from the trials (odds ratio (OR) 2.01, 95% CI 1.71 to 2.37, n = 3569, 7 studies) or to experience an adverse event during the trials (OR 2.16, 95% CI 1.82 to 2.57, n = 3587, 7 studies). AUTHORS' CONCLUSIONS Rivastigmine (6 to 12 mg daily orally or 9.5 mg daily transdermally) appears to be beneficial for people with mild to moderate Alzheimer's disease. In comparisons with placebo, better outcomes were observed for rate of decline of cognitive function and activities of daily living, although the effects were small and of uncertain clinical importance. There was also a benefit from rivastigmine on the outcome of clinician's global assessment. There were no differences between the rivastigmine group and placebo group in behavioural change or impact on carers. At these doses the transdermal patch may have fewer side effects than the capsules but has comparable efficacy. The quality of evidence is only moderate for all of the outcomes reviewed because of a risk of bias due to dropouts. All the studies with usable data were industry funded or sponsored. This review has not examined economic data.
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Affiliation(s)
- Jacqueline S Birks
- University of OxfordCentre for Statistics in Medicine, Nuffield Department of Orthopaedics, Rheumatology and Musculoskeletal SciencesBotnar Research Centre, Windmill RoadOxfordUKOX3 7LD
| | | | - John Grimley Evans
- University of OxfordDivision of Clinical Geratology, Nuffield Department of Clinical MedicineRadcliffe InfirmaryWoodstock RoadOxfordUKOX2 6HE
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Abstract
BACKGROUND Alzheimer's disease is the commonest cause of dementia affecting older people. One of the therapeutic strategies aimed at ameliorating the clinical manifestations of Alzheimer's disease is to enhance cholinergic neurotransmission in the brain by the use of cholinesterase inhibitors to delay the breakdown of acetylcholine released into synaptic clefts. Tacrine, the first of the cholinesterase inhibitors to undergo extensive trials for this purpose, was associated with significant adverse effects including hepatotoxicity. Other cholinesterase inhibitors, including rivastigmine, with superior properties in terms of specificity of action and lower risk of adverse effects have since been introduced. Rivastigmine has received approval for use in 60 countries including all member states of the European Union and the USA. OBJECTIVES To determine the clinical efficacy and safety of rivastigmine for patients with dementia of Alzheimer's type. SEARCH METHODS We searched ALOIS, the Cochrane Dementia and Cognitive Improvement Group Specialized Register, on 2 March 2015 using the terms: Rivastigmine OR exelon OR ENA OR "SDZ ENA 713". ALOIS contains records of clinical trials identified from monthly searches of a number of major healthcare databases (Cochrane Library, MEDLINE, EMBASE, PsycINFO, CINAHL, LILACS), numerous trial registries and grey literature sources. SELECTION CRITERIA We included all unconfounded, double-blind, randomised, controlled trials in which treatment with rivastigmine was administered to patients with dementia of the Alzheimer's type for 12 weeks or more and its effects compared with those of placebo in a parallel group of patients, or where two formulations of rivastigmine were compared. DATA COLLECTION AND ANALYSIS One review author (JSB) applied the study selection criteria, assessed the quality of studies and extracted data. MAIN RESULTS A total of 13 trials met the inclusion criteria of the review. The trials had a duration of between 12 and 52 weeks. The older trials tested a capsule form with a dose of up to 12 mg/day. Trials reported since 2007 have tested continuous dose transdermal patch formulations delivering 4.6, 9.5 and 17.7 mg/day.Our main analysis compared the safety and efficacy of rivastigmine 6 to 12 mg/day orally or 9.5 mg/day transdermally with placebo.Seven trials contributed data from 3450 patients to this analysis. Data from another two studies were not included because of a lack of information and methodological concerns. All the included trials were multicentre trials and recruited patients with mild to moderate Alzheimer's disease with a mean age of about 75 years. All had low risk of bias for randomisation and allocation but the risk of bias due to attrition was unclear in four studies, low in one study and high in two studies.After 26 weeks of treatment rivastigmine compared to placebo was associated with better outcomes for cognitive function measured with the Alzheimer's Disease Assessment Scale-Cognitive (ADAS-Cog) score (mean difference (MD) -1.79; 95% confidence interval (CI) -2.21 to -1.37, n = 3232, 6 studies) and the Mini-Mental State Examination (MMSE) score (MD 0.74; 95% CI 0.52 to 0.97, n = 3205, 6 studies), activities of daily living (SMD 0.20; 95% CI 0.13 to 0.27, n = 3230, 6 studies) and clinician rated global impression of changes, with a smaller proportion of patients treated with rivastigmine experiencing no change or a deterioration (OR 0.68; 95% CI 0.58 to 0.80, n = 3338, 7 studies).Three studies reported behavioural change, and there were no differences compared to placebo (standardised mean difference (SMD) -0.04; 95% CI -0.14 to 0.06, n = 1529, 3 studies). Only one study measured the impact on caregivers using the Neuropsychiatric Inventory-Caregiver Distress (NPI-D) scale and this found no difference between the groups (MD 0.10; 95% CI -0.91 to 1.11, n = 529, 1 study). Overall, participants who received rivastigmine were about twice as likely to withdraw from the trials (odds ratio (OR) 2.01, 95% CI 1.71 to 2.37, n = 3569, 7 studies) or to experience an adverse event during the trials (OR 2.16, 95% CI 1.82 to 2.57, n = 3587, 7 studies). AUTHORS' CONCLUSIONS Rivastigmine (6 to 12 mg daily orally or 9.5 mg daily transdermally) appears to be beneficial for people with mild to moderate Alzheimer's disease. In comparisons with placebo, better outcomes were observed for rate of decline of cognitive function and activities of daily living, although the effects were small and of uncertain clinical importance. There was also a benefit from rivastigmine on the outcome of clinician's global assessment. There were no differences between the rivastigmine group and placebo group in behavioural change or impact on carers. At these doses the transdermal patch may have fewer side effects than the capsules but has comparable efficacy. The quality of evidence is only moderate for all of the outcomes reviewed because of a risk of bias due to dropouts. All the studies with usable data were industry funded or sponsored. This review has not examined economic data.
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Affiliation(s)
- Jacqueline S Birks
- Centre for Statistics in Medicine, Nuffield Department of Orthopaedics, Rheumatology and Musculoskeletal Sciences, University of Oxford, Botnar Research Centre, Windmill Road, Oxford, UK, OX3 7LD
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Ward HC, Kotthaus S, Grimmond CSB, Bjorkegren A, Wilkinson M, Morrison WTJ, Evans JG, Morison JIL, Iamarino M. Effects of urban density on carbon dioxide exchanges: Observations of dense urban, suburban and woodland areas of southern England. Environ Pollut 2015; 198:186-200. [PMID: 25613466 DOI: 10.1016/j.envpol.2014.12.031] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/27/2014] [Revised: 10/12/2014] [Accepted: 12/26/2014] [Indexed: 05/22/2023]
Abstract
Anthropogenic and biogenic controls on the surface-atmosphere exchange of CO2 are explored for three different environments. Similarities are seen between suburban and woodland sites during summer, when photosynthesis and respiration determine the diurnal pattern of the CO2 flux. In winter, emissions from human activities dominate urban and suburban fluxes; building emissions increase during cold weather, while traffic is a major component of CO2 emissions all year round. Observed CO2 fluxes reflect diurnal traffic patterns (busy throughout the day (urban); rush-hour peaks (suburban)) and vary between working days and non-working days, except at the woodland site. Suburban vegetation offsets some anthropogenic emissions, but 24-h CO2 fluxes are usually positive even during summer. Observations are compared to estimated emissions from simple models and inventories. Annual CO2 exchanges are significantly different between sites, demonstrating the impacts of increasing urban density (and decreasing vegetation fraction) on the CO2 flux to the atmosphere.
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Affiliation(s)
- H C Ward
- Department of Meteorology, University of Reading, Reading, RG6 6BB, UK; Centre for Ecology and Hydrology, Wallingford, Oxfordshire, OX10 8BB, UK.
| | - S Kotthaus
- Department of Meteorology, University of Reading, Reading, RG6 6BB, UK; Department of Geography, King's College London, London, WC2R 2LS, UK
| | - C S B Grimmond
- Department of Meteorology, University of Reading, Reading, RG6 6BB, UK
| | - A Bjorkegren
- Department of Geography, King's College London, London, WC2R 2LS, UK
| | - M Wilkinson
- Forest Research, Centre for Forestry and Climate Change, Alice Holt Lodge, Farnham, Surrey, GU10 4LH, UK
| | - W T J Morrison
- Department of Meteorology, University of Reading, Reading, RG6 6BB, UK
| | - J G Evans
- Centre for Ecology and Hydrology, Wallingford, Oxfordshire, OX10 8BB, UK
| | - J I L Morison
- Forest Research, Centre for Forestry and Climate Change, Alice Holt Lodge, Farnham, Surrey, GU10 4LH, UK
| | - M Iamarino
- Scuola di Ingegneria, Università degli Studi della Basilicata, 85100, Potenza, Italy
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Evans G, Evans JG, Lasserson DS. Questionnaire study of the association between patient numbers and regular visiting by general practitioners in care homes. Age Ageing 2012; 41:269-72. [PMID: 22258115 DOI: 10.1093/ageing/afr183] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022] Open
Abstract
BACKGROUND regular visiting in care homes enables proactive care. Surveys of managers found variation in medical care yet little is known about factors influencing general practitioners (GPs) visiting patterns. We examined whether practice factors including numbers of registered patients are associated with regular visiting. DESIGN AND SETTING postal questionnaires sent to 73 care homes of European Care Group and separate questionnaires to visiting practices. METHODS information on regularity of visiting was requested from homes and practices. Practices were asked for numbers of doctors and training status. As data were not normally distributed, non-parametric tests were used to compare practices regularly visiting with those visiting only on request in terms of numbers of registered care home patients. RESULTS forty-seven (64%) of homes responded, with care provided for 1,867 patients by 162 practices. Practices visiting regularly had significantly more patients than practices that did not [median (IQR) 32 (28) versus 3 (5), P < 0.001]. Ninety-five (31%) of practices responded showing a similar association of registrations with regular visiting [median (IQR) 20 (37) versus 4 (4), P < 0.001]. There was no association between numbers of doctors or training status on regular visiting. CONCLUSION the number of registered patients is strongly associated with regular care home visiting. Aligning practices with care homes thereby increasing registered patients per practice could encourage proactive care.
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Affiliation(s)
- Gillie Evans
- Green Templeton College, University of Oxford, 4, Gracious Street, Whittlesey, Peterborough PE7 1AP, UK.
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Hickling KC, Hitchcock JM, Chipman JK, Hammond TG, Evans JG. Induction and progression of cholangiofibrosis in rat liver injured by oral administration of furan. Toxicol Pathol 2010; 38:213-29. [PMID: 20231548 DOI: 10.1177/0192623309357945] [Citation(s) in RCA: 30] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/27/2023]
Abstract
Cholangiofibrosis is a structural anomaly that precedes the development of cholangiocarcinoma in some rodent models. In this article, the authors examine the contribution of the epithelial and mesenchymal cells in the pathogenesis of this complex lesion. Furan was administered to rats by gavage in corn oil at 30 mg/kg b.w. (five daily doses per week) and livers were sampled between eight hr to three months. Characteristically the administration of furan caused centrilobular injury, and restoration was accomplished by proliferation of hepatocytes. Some areas of the liver were, however, more severely affected, and here, injury extended into portal and capsular areas, which resulted in a rapid proliferation of ductular cells that extended into the parenchyma accompanied by a subtype of liver fibroblasts. These ductules either differentiated into hepatocytes, with loss of the associated fibroblasts, or progressed to form tortuous ductular structures that replaced much of the parenchyma, leading to cholangiofibrosis. Although it is unclear what determines the difference in the hepatic response, a loss of micro-environmental cues that instigate hepatocyte differentiation and termination of the hepatocyte stem cell repair response may be perturbed by continual furan administration that results in an irreversible expansile lesion that may mimic the features of cholangiocarcinoma.
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Affiliation(s)
- K C Hickling
- Safety Assessment, AstraZeneca R&D Charnwood, Loughborough, United Kingdom.
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Evans JG. Hypertension and stroke in an elderly population. Acta Med Scand Suppl 2009; 676:22-32. [PMID: 6581690 DOI: 10.1111/j.0954-6820.1983.tb19329.x] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/20/2023]
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Abstract
BACKGROUND Alzheimer's disease (AD) is the commonest cause of dementia affecting older people. One of the therapeutic strategies aimed at ameliorating the clinical manifestations of Alzheimer's disease is to enhance cholinergic neurotransmission in relevant parts of the brain by the use of cholinesterase inhibitors to delay the breakdown of acetylcholine released into synaptic clefts. Tacrine, the first of the cholinesterase inhibitors to undergo extensive trials for this purpose, was associated with significant adverse effects including hepatotoxicity. Other cholinesterase inhibitors, including rivastigmine, with superior properties in terms of specificity of action and low risk of adverse effects, have now been introduced. Rivastigmine has received approval for use in 60 countries including all member states of the European Union and the USA. OBJECTIVES To determine the clinical efficacy and safety of rivastigmine for patients with dementia of Alzheimer's type. SEARCH STRATEGY The Specialized Register of the Cochrane Dementia and Cognitive Improvement Group (CDCIG), The Cochrane Library, MEDLINE, EMBASE, PsycINFO, CINAHL and LILACS were searched on 27 March 2008 using the terms: Rivastigmine OR exelon OR ENA OR "SDZ ENA 713" . The CDCIG Specialized Register contains records from all major health care databases (The Cochrane Library, MEDLINE, EMBASE, PsycINFO, CINAHL, LILACS) as well as from many clinical trials registries and grey literature sources. SELECTION CRITERIA All unconfounded, double-blind, randomized trials in which treatment with rivastigmine was administered to patients with dementia of the Alzheimer's type for more than two weeks and its effects compared with those of placebo in a parallel group of patients. DATA COLLECTION AND ANALYSIS One reviewer (JSB) applied study selection criteria, assessed the quality of studies and extracted data. MAIN RESULTS Nine trials, involving 4775 participants, were included in the analyses. Use of rivastigmine in high doses was associated with statistically significant benefits on several measures. High-dose rivastigmine (6 to 12 mg daily) was associated with a two-point improvement in cognitive function on the ADAS-Cog score compared with placebo (weighted mean difference -1.99, 95% confidence interval -2.49 to -1.50, on an intention-to-treat basis) and a 2.2 point improvement in activities of daily living assessed on the Progressive Deterioration Scale (weighted mean difference -2.15, 95% confidence interval -3.16 to -1.13, on an intention-to-treat basis) at 26 weeks. At lower doses (4 mg daily or lower) differences were in the same direction but were statistically significant only for cognitive function. There were statistically significantly higher numbers of events of nausea, vomiting, diarrhoea, anorexia, headache, syncope, abdominal pain and dizziness among patients taking high-dose rivastigmine than among those taking placebo. There was some evidence that adverse events might be less common with more frequent, smaller doses of rivastigmine. The 2008 update includes a new study testing two types of rivastigmine transdermal patch, one delivering a higher dose than previously tested (17.4 mg/day) and a smaller patch delivering 9.6 mg/day. The efficacy of the smaller patch was not significantly different compared with the capsules of similar daily dose, but was associated with significantly fewer adverse events of nausea, vomiting, dizziness and asthenia. The efficacy of the larger patch was not significantly different compared with the smaller patch, but the smaller patch was associated with significantly fewer adverse events of nausea, vomiting, weight loss and dizziness. There appears to be advantages associated with the smaller patch compared with both the higher dose patch and the 6-12 mg/day capsules. AUTHORS' CONCLUSIONS Rivastigmine appears to be beneficial for people with mild to moderate Alzheimer's disease. In comparisons with placebo, improvements were seen in the rate of decline of cognitive function, activities of daily living, and severity of dementia with daily doses of 6 to 12 mg. Adverse events were consistent with the cholinergic actions of the drug. A transdermal patch has been tested in one trial, and there is evidence that the lower dose smaller patch is associated with fewer side effects than the capsules or the higher dose larger patch and has comparable efficacy to both. This review has not examined economic data.
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Affiliation(s)
- Jacqueline Birks
- Centre for Statistics in Medicine, University of Oxford, Wolfson College, Linton Road, Oxford, UK, OX2 6UD.
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Abstract
BACKGROUND Extracts of the leaves of the maidenhair tree, Ginkgo biloba, have long been used in China as a traditional medicine for various disorders of health. A standardized extract is widely prescribed for the treatment of a range of conditions including memory and concentration problems, confusion, depression, anxiety, dizziness, tinnitus and headache. The mechanisms of action are thought to reflect the action of several components of the extract and include increasing blood supply by dilating blood vessels, reducing blood viscosity, modification of neurotransmitter systems, and reducing the density of oxygen free radicals. OBJECTIVES To assess the efficacy and safety of Ginkgo biloba for dementia or cognitive decline. SEARCH STRATEGY The Specialized Register of the Cochrane Dementia and Cognitive Improvement Group (CDCIG), The Cochrane Library, MEDLINE, EMBASE, PsycINFO, CINAHL and LILACS were searched on 20 September 2007 using the terms: ginkgo*, tanakan, EGB-761, EGB761, "EGB 761" and gingko*. The CDCIG Specialized Register contains records from all major health care databases (The Cochrane Library, MEDLINE, EMBASE, PsycINFO, CINAHL, LILACS) as well as from many trials databases and grey literature sources. SELECTION CRITERIA Randomized, double-blind studies, in which extracts of Ginkgo biloba at any strength and over any period were compared with placebo for their effects on people with acquired cognitive impairment, including dementia, of any degree of severity. DATA COLLECTION AND ANALYSIS Data were extracted from the published reports of the included studies, pooled where appropriate and the treatment effects or the risks and benefits estimated. MAIN RESULTS 36 trials were included but most were small and of duration less than three months. Nine trials were of six months duration (2016 patients). These longer trials were the more recent trials and generally were of adequate size, and conducted to a reasonable standard. Most trials tested the same standardised preparation of Ginkgo biloba, EGb 761, at different doses, which are classified as high or low. The results from the more recent trials showed inconsistent results for cognition, activities of daily living, mood, depression and carer burden. Of the four most recent trials to report results three found no difference between Ginkgo biloba and placebo, and one found very large treatment effects in favour of Ginkgo biloba.There are no significant differences between Ginkgo biloba and placebo in the proportion of participants experiencing adverse events.A subgroup analysis including only patients diagnosed with Alzheimer's disease (925 patients from nine trials) also showed no consistent pattern of any benefit associated with Ginkgo biloba. AUTHORS' CONCLUSIONS Ginkgo biloba appears to be safe in use with no excess side effects compared with placebo. Many of the early trials used unsatisfactory methods, were small, and publication bias cannot be excluded. The evidence that Ginkgo biloba has predictable and clinically significant benefit for people with dementia or cognitive impairment is inconsistent and unreliable.
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Affiliation(s)
- Jacqueline Birks
- Centre for Statistics in Medicine, University of Oxford, Wolfson College, Linton Road, Oxford, UK, OX2 6UD.
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Abstract
BACKGROUND Folate deficiency can result in congenital neural tube defects and megaloblastic anaemia. Low folate levels may be due to insufficient dietary intake or inefficient absorption, but impaired metabolic utilization also occurs.Because B12 deficiency can produce a similar anaemia to folate deficiency, there is a risk that folate supplementation can delay the diagnosis of B12 deficiency, which can cause irreversible neurological damage. Folic acid supplements may sometimes therefore include vitamin B12 supplements with simultaneous administration of vitamin B12.Lesser degrees of folate inadequacy are associated with high blood levels of the amino acid homocysteine which has been linked with the risk of arterial disease, dementia and Alzheimer's disease. There is therefore interest in whether dietary supplementation can improve cognitive function in the elderly.However, any apparent benefit from folic acid which was given in combination with B12 needs to be "corrected" for any effect of vitamin B12 alone. A separate Cochrane review of vitamin B12 and cognitive function has therefore been published. OBJECTIVES To examine the effects of folic acid supplementation, with or without vitamin B12, on elderly healthy or demented people, in preventing cognitive impairment or retarding its progress. SEARCH STRATEGY Trials were identified from a search of the Cochrane Dementia and Cognitive Improvement Group's Specialized Register on 10 October 2007 using the terms: folic acid, folate, vitamin B9, leucovorin, methyltetrahydrofolate, vitamin B12, cobalamin and cyanocobalamin. This Register contains references from all major health care databases and many ongoing trials databases. In addition MEDLINE, EMBASE, CINAHL, PsychINFO and LILACS were searched (years 2003-2007) for additional trials of folate with or without vitamin B12 on healthy elderly people. SELECTION CRITERIA All double-blind, placebo-controlled, randomized trials, in which supplements of folic acid with or without vitamin B12 were compared with placebo for elderly healthy people or people with any type of dementia or cognitive impairment. DATA COLLECTION AND ANALYSIS The reviewers independently applied the selection criteria and assessed study quality. One reviewer extracted and analysed the data. In comparing intervention with placebo, weighted mean differences and standardized mean difference or odds ratios were estimated. MAIN RESULTS Eight randomized controlled trials fulfilled the inclusion criteria for this review. Four trials enrolled healthy older people, and four recruited participants with mild to moderate cognitive impairment or dementia with or without diagnosed folate deficiency. Pooling the data was not possible owing to heterogeneity in sample selections, outcomes, trial duration, and dosage. Two studies involved a combination of folic acid and vitamin B12.There is no adequate evidence of benefit from folic acid supplementation with or without vitamin B12 on cognitive function and mood of unselected healthy elderly people. However, in one trial enrolling a selected group of healthy elderly people with high homocysteine levels, 800 mcg/day folic acid supplementation over three years was associated with significant benefit in terms of global functioning (WMD 0.05, 95% CI 0.004 to 0.096, P = 0.033); memory storage (WMD 0.14, 95% CI 0.04 to 0.24, P = 0.006) and information-processing speed (WMD 0.09, 95% CI 0.02 to 0.16, P = 0.016).Four trials involved people with cognitive impairment. In one pilot trial enrolling people with Alzheimer's disease, the overall response to cholinesterase inhibitors significantly improved with folic acid at a dose of 1mg/day (odds ratio: 4.06, 95% CI 1.22 to 13.53; P = 0.02) and there was a significant improvement in scores on the Instrumental Activities of Daily Living and the Social Behaviour subscale of the Nurse's Observation Scale for Geriatric Patients (WMD 4.01, 95% CI 0.50 to 7.52, P = 0.02). Other trials involving people with cognitive impairment did not show any benefit in measures of cognitive function from folic acid, with or without vitamin B12.Folic acid plus vitamin B12 was effective in reducing serum homocysteine concentrations (WMD -5.90, 95% CI -8.43 to -3.37, P < 0.00001). Folic acid was well tolerated and no adverse effects were reported. AUTHORS' CONCLUSIONS The small number of studies which have been done provide no consistent evidence either way that folic acid, with or without vitamin B12, has a beneficial effect on cognitive function of unselected healthy or cognitively impaired older people. In a preliminary study, folic acid was associated with improvement in the response of people with Alzheimer's disease to cholinesterase inhibitors. In another, long-term use appeared to improve the cognitive function of healthy older people with high homocysteine levels. More studies are needed on this important issue.
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Affiliation(s)
- Reem Malouf
- Department of Psychiatry, Oxfordshire and Buckinghamshire Mental Health Trust, John Radcliffe Hospital (4th Floor, Room 4401C), Headington, Oxford, UK, OX3 9DU.
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Clarke R, Birks J, Nexo E, Ueland PM, Schneede J, Scott J, Molloy A, Evans JG. Low vitamin B-12 status and risk of cognitive decline in older adults. Am J Clin Nutr 2007; 86:1384-91. [PMID: 17991650 DOI: 10.1093/ajcn/86.5.1384] [Citation(s) in RCA: 136] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
Abstract
BACKGROUND Elevated total homocysteine (tHcy) concentrations have been associated with cognitive impairment, but it is unclear whether low vitamin B-12 or folate status is responsible for cognitive decline. OBJECTIVE We examined the associations of cognitive decline with vitamin B-12 and folate status in a longitudinal cohort study performed from 1993 to 2003 in Oxford, United Kingdom. DESIGN Cognitive function was assessed with the Mini-Mental State Examination on >/=3 occasions during 10 y and related to serum concentrations of vitamin B-12, holotranscobalamin (holoTC), tHcy, methylmalonic acid (MMA), and folate with the use of linear mixed models in 1648 participants who provided blood in 1995. RESULTS Cognitive function declined abruptly at younger ages in some participants but remained intact in others until very old age. In multivariate regression analyses after adjustment for established risk factors, concentrations of holoTC (a marker of reduced vitamin B-12 status), tHcy, and MMA predicted cognitive decline, but folate did not. A doubling in holoTC concentrations (from 50 to 100 pmol/L) was associated with a 30% slower rate of cognitive decline (-0.137 to -0.083), whereas a doubling in tHcy (from 10 to 20 micromol/L) or MMA (from 0.25 to 0.50 micromol/L) was associated with >50% more rapid cognitive decline (-0.090 to -0.169) and (-0.104 to -0.169), respectively. After adjustment for all vitamin markers simultaneously, the associations of cognitive decline with holoTC and MMA remained significant. CONCLUSIONS Low vitamin B-12 status was associated with more rapid cognitive decline. Randomized trials are required to determine the relevance of vitamin B-12 supplementation for prevention of dementia.
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Affiliation(s)
- Robert Clarke
- Clinical Trial Service Unit, University of Oxford,, University of Oxford, Oxford, United Kingdom.
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Abstract
The concept of disease has a long and changing history, and has accumulated implications that can be unhelpful. The traditional distinction made between 'normal ageing' and 'disease' identifies research into the impact of an ageing population as having arisen within clinical medicine with its tradition of dichotomous thinking. The model is inappropriate for clinical practice among the elderly where diseases should be relegated to the role of mechanisms producing functional problems, and where interventions may not be of the traditional medical form. In this context the concept of 'normal ageing' can act as an excuse for inaction. For gerontological research the basic model is of the interaction between extrinsic and intrinsic factors. We lack the means at present to identify intrinsic processes, although they may be found among the residual ageing effects when extrinsic processes have been excluded. Intrinsic ageing processes may ultimatedly be identifiable on the basis of biological theory. Until this is possible we should study age-associated phenomena without prematurely conceived notions about their origins.
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Affiliation(s)
- J G Evans
- Nuffield Department of Clinical Medicine, Radcliffe Infirmary, Oxford, UK
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Clarke R, Sherliker P, Hin H, Nexo E, Hvas AM, Schneede J, Birks J, Ueland PM, Emmens K, Scott JM, Molloy AM, Evans JG. Detection of Vitamin B12 Deficiency in Older People by Measuring Vitamin B12 or the Active Fraction of Vitamin B12, Holotranscobalamin. Clin Chem 2007; 53:963-70. [PMID: 17363419 DOI: 10.1373/clinchem.2006.080382] [Citation(s) in RCA: 95] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
Abstract
Abstract
Background: Impaired vitamin B12 function and decreased vitamin B12 status have been associated with neurological and cognitive impairment. Current assays analyze total vitamin B12 concentration, only a small percentage of which is metabolically active. Concentrations of this active component, carried on holotranscobalamin (holoTC), may be of greater relevance than total vitamin B12.
Methods: We compared the utility of serum holoTC with conventional vitamin B12 for detection of vitamin B12 deficiency in a population-based study of older people, using increased methylmalonic acid (MMA) concentrations as a marker of metabolic vitamin B12 deficiency in the overall population (n = 2403) and in subsets with normal (n = 1651) and abnormal (n = 752) renal function.
Results: Among all participants, 6% had definite (MMA >0.75 μmol/L) and 16% had probable (MMA >0.45 μmol/L) metabolic vitamin B12 deficiency. In receiver operating characteristic curves for detection of definite vitamin B12 deficiency, holoTC had a greater area under the curve (AUC) compared with vitamin B12 in all participants (0.85 vs 0.76; P <0.001) and in subsets with normal (AUC: 0.87 vs 0.79; P <0.001) and abnormal (AUC: 0.85 vs 0.74; P = 0.002) renal function. Similar findings were observed for detection of moderate vitamin B12 deficiency. Whereas the positive predictive value for both holoTC and vitamin B12 was greater for detection of probable than definite vitamin B12 deficiency, both tests were associated with more false-positive than true-positive test results.
Conclusions: HoloTC has a modestly superior diagnostic accuracy compared with conventional vitamin B12 for the detection of vitamin B12 deficiency, but neither test can be recommended to screen asymptomatic populations.
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Affiliation(s)
- Robert Clarke
- Clinical Trial Service Unit, University of Oxford, Oxford, United Kingdom.
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Abstract
BACKGROUND Polymorphisms for the microsomal triglyceride transfer protein (MTTP) gene have been associated with longevity and with lower risk for cardiovascular mortality. However, the association of MTTP with longevity has been contested in a large German collection of nonagenarians and centenarians. METHODS We made a detailed characterization of MTTP haplotype carrier status in a cohort of 1398 old men and women (mean age 78 years) and a population-based cohort (n = 777) of younger controls (mean age 40 years) in Oxford, England. RESULTS There were no significant differences in haplotypes for MTTP gene between the younger and older age groups. CONCLUSION This study, which adopted a more detailed genetic analysis of the MTTP gene in a large case-control study of older people provides reliable evidence against any significant association of the MTTP gene with longevity.
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Affiliation(s)
- Matt J Neville
- Oxford Centre for Diabetes, Endocrinology and Metabolism, University of Oxford, UK
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Hin H, Clarke R, Sherliker P, Atoyebi W, Emmens K, Birks J, Schneede J, Ueland PM, Nexo E, Scott J, Molloy A, Donaghy M, Frost C, Evans JG. Clinical relevance of low serum vitamin B12 concentrations in older people: the Banbury B12 study. Age Ageing 2006; 35:416-22. [PMID: 16709605 DOI: 10.1093/ageing/afl033] [Citation(s) in RCA: 128] [Impact Index Per Article: 7.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022] Open
Abstract
BACKGROUND low vitamin B12 concentrations are common in older people, but the clinical relevance of biochemical evidence of vitamin B12 deficiency in the absence of anaemia is uncertain. OBJECTIVE to examine associations of cognitive impairment, depression and neuropathy with blood measurements of vitamin B12 and folate status in older people. DESIGN cross-sectional study in general practice in Banbury, England. PARTICIPANTS a total of 1,000 individuals aged 75 years or older living in the community. RESULTS low vitamin B12 concentrations were identified in 13% of older people and were associated with memory impairment and depression. After adjustment for age, sex and smoking, individuals with vitamin B12 or holotranscobalamin (holoTC) in the bottom compared with top quartiles had a 2-fold risk (OR = 2.17; 95% CI 1.11-4.27) and a 3-fold risk (OR = 3.02; 95% CI 1.31-6.98) of cognitive impairment, respectively. Low vitamin B12 status was also associated with missing ankle tendon jerks but not with depression. Treatment with vitamin B12 for 3 months corrected the biochemical abnormalities but had no effect on any of the clinical measurements. CONCLUSIONS low vitamin B12 concentrations are associated with cognitive impairment and missing ankle tendon jerks in older people in the absence of anaemia. Large-scale trials of vitamin B12 supplementation are required to assess the clinical significance of these associations.
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Affiliation(s)
- Harold Hin
- Hightown Surgery, Hightown Gardens, Banbury, UK
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Devlin AM, Clarke R, Birks J, Evans JG, Halsted CH. Interactions among polymorphisms in folate-metabolizing genes and serum total homocysteine concentrations in a healthy elderly population. Am J Clin Nutr 2006; 83:708-13. [PMID: 16522921 DOI: 10.1093/ajcn.83.3.708] [Citation(s) in RCA: 76] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022] Open
Abstract
BACKGROUND Homocysteine concentrations are influenced by vitamin status and genetics, especially several polymorphisms in folate-metabolizing genes. OBJECTIVE We examined the interactions and associations with serum total homocysteine (tHcy) and folate concentrations of polymorphisms in the following folate-metabolizing genes: methylenetetrahydrofolate reductase (MTHFR), reduced folate carrier 1 (RFC1), and glutamate carboxypeptidase II (GCPII). DESIGN Healthy volunteers (436 men and 606 women; mean age: 77.9 y) were randomly selected from among residents of Oxford, United Kingdom. We determined the individual effects and interactions of the MTHFR 677C-->T, MTHFR 1298A-->C, RFC1 80G-->A, and GCPII 1561C-->T polymorphisms on serum tHcy and folate concentrations. RESULTS Subjects with the MTHFR 677TT genotype had higher serum tHcy concentrations than did those with the MTHFR 677CC genotype (P < 0.001), and this effect was greater in subjects with low serum folate status (P for interaction = 0.026). The MTHFR 1298A-->C, RFC1 80G-->A, and GCPII 1561C-->T polymorphisms had no individual effects on serum tHcy or folate concentrations. There was no interactive effect of the MTHFR 677C-->T and MTHFR 1298A-->C polymorphisms on tHcy concentrations. An interaction (P = 0.05) was observed between the MTHFR 677TT and RFC1 80GG genotypes, whereby persons with this genotype combination had a mean (+/-SEM) serum tHcy concentration (18.5 +/- 1.2 micromol/L) that was 5.1 micromol/L greater than the mean value of 13.4 +/- 0.2 micromol/L for the whole population. CONCLUSIONS Folate and tHcy concentrations were not affected individually by the MTHFR 1298A-->C, RFC1 80G-->A, or GCPII 1561C-->T polymorphisms or by combinations of the MTHFR 677C-->T and MTHFR 1298A-->C genotypes. An interaction between the MTHFR 677TT and RFC1 80GG genotypes was observed whereby persons with this combination had higher serum tHcy.
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Affiliation(s)
- Angela M Devlin
- Department of Internal Medicine, University of California, Davis, Davis, CA, USA.
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Evans JG. Scientific aspects of ageing: a lordly report. J R Soc Med 2005; 98:482-3. [PMID: 16260791 PMCID: PMC1275990 DOI: 10.1177/014107680509801102] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022] Open
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Jamieson SE, White JK, Howson JMM, Pask R, Smith AN, Brayne C, Evans JG, Xuereb J, Cairns NJ, Rubinsztein DC, Blackwell JM. Candidate gene association study of solute carrier family 11a members 1 (SLC11A1) and 2 (SLC11A2) genes in Alzheimer's disease. Neurosci Lett 2005; 374:124-8. [PMID: 15644277 DOI: 10.1016/j.neulet.2004.10.038] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/09/2004] [Revised: 10/14/2004] [Accepted: 10/14/2004] [Indexed: 02/03/2023]
Abstract
Divalent cations are strongly implicated in Alzheimer's disease (AD) pathogenesis, and can regulate amyloid beta-peptide aggregation. The proton-divalent cation transporters encoded by SLC11A1 (formerly NRAMP1) on chromosome 2q35, and SLC11A2 (also known as DCT1 and DMT1) on chromosome 12q13, are expressed in the brain and regulate ion homeostasis from endosomal compartments. SLC11A1 also has pleiotropic effects on pro-inflammatory responses that may be important in AD. We analyzed seven informative polymorphisms in the SLC11A1 and SLC11A2 genes encoding these divalent cation transporters in a sample of 216 late-onset AD cases and 323 age-matched controls. We found only borderline evidence (p=0.08) for an allelic association between SNP rs407135 at SLC11A2 and AD, in which the variant allele was protective (odd ratio (OR) 0.77; 95% CI 0.56-1.04) relative to the more common allele. There was no interaction with apolipoprotein E (APOE) varepsilon4, but stratification by gender showed that all of the effect of SLC11A2 was in the male patient group. No other associations with AD were observed at SLC11A1 or SLC11A2, indicating no major effect of either gene for the occurrence of AD.
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Affiliation(s)
- Sarra E Jamieson
- Cambridge Institute for Medical Research, University of Cambridge School of Clinical Medicine, Wellcome Trust/MRC Building, Addenbrooke's Hospital, Hills Rd., Cambridge CB2 2XY, UK
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Cook LJ, Ho LW, Wang L, Terrenoire E, Brayne C, Evans JG, Xuereb J, Cairns NJ, Turic D, Hollingworth P, Moore PJ, Jehu L, Archer N, Walter S, Foy C, Edmondson A, Powell J, Lovestone S, Williams J, Rubinsztein DC. Candidate gene association studies of genes involved in neuronal cholinergic transmission in Alzheimer's disease suggests choline acetyltransferase as a candidate deserving further study. Am J Med Genet B Neuropsychiatr Genet 2005; 132B:5-8. [PMID: 15690550 DOI: 10.1002/ajmg.b.30068] [Citation(s) in RCA: 34] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/30/2022]
Abstract
Consistent deficits in the cholinergic system are evident in the brains of Alzheimer's Disease (AD) patients, including reductions in the activities of acetylcholine, acetylcholinesterase (AChE), and choline acetyltransferase (ChAT), increased butyrylcholinesterase (BChE) activity, and a selective loss of nicotinic acetylcholine receptors (nAChRs). Accordingly, we have analyzed polymorphisms in the genes encoding AChE, ChAT, BChE, and several of the subunit genes from neuronal nAChRs, for genetic associations with late-onset AD. A significant association for disease was detected for a non-coding polymorphism in ChAT (allele chi(1) (2) = 12.84, P = 0.0003; genotype chi(2) (2) = 11.89, P = 0.0026). Although replication analysis did not confirm the significance of this finding when the replication samples were considered alone (allele chi(1) (2) = 1.02, P = 0.32; genotype chi(2) (2) = 1.101, P = 0.58) the trends were in the correct direction and a significant association remained when the two sample sets were pooled (allele chi(1) (2) = 12.37, P = 0.0004; genotype chi(2) (2) = 11.61, P = 0.003). Previous studies have reported significant disease associations for both the K-variant of BChE and the coding ChAT rs3810950 polymorphism with AD. Replication analyses of these two loci failed to detect any significant association for disease in our case-control samples.
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Affiliation(s)
- Lynnette J Cook
- Department of Medical Genetics, Cambridge Institute for Medical Research, Addenbrooke's Hospital, Hills Road, Cambridge, CB2 2XY, UK
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Affiliation(s)
- John Grimley Evans
- Clinical Geratology, University of Oxford, Green College, Oxford OX2 6HG, England.
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Bullock DB, Evans JG. Dangerous jobsworths. Br J Gen Pract 2004; 54:870. [PMID: 15527619 PMCID: PMC1324931] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 05/01/2023] Open
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Abstract
Dementia is an acquired global impairment of cognitive capacities. Approximately 5% of people aged over 65 yr are affected by dementia, and some 70% of cases are thought to be due primarily to Alzheimer's disease. Descriptions of the clinical manifestations of Alzheimer's disease have been increasingly refined in the last decade but there is no diagnostic test for what remains fundamentally a pathologically defined condition. At the present time interventions for Alzheimer's disease are limited to those that modify the manifestations of the disease, and foremost amongst the candidates available are the cholinesterase inhibitors. The rationale for the use of cholinergic drugs for Alzheimer's disease lies in enhancing the secretion of, or prolonging the half-life of, acetylcholine in the brain. Several potential compounds have been tested, but short half-lives and a high incidence of cholinergic and other adverse effects have eliminated most. Only three are widely licensed for use, donepezil, galantamine and rivastigmine. Their efficacy is relatively modest. These drugs have been tested in 32 randomized, placebo-controlled trials. The trials assess cognitive function primarily, and in addition they may assess global function, activities of daily living, quality of life and behavioural disturbance typically over 3 or 6 months. The performance of each drug is summarized in a Cochrane review, a systematic review carried out according to strict guidelines. There was a significant benefit in favour of treatment compared with placebo for cognition and activities of daily living, but withdrawals due to adverse events were significantly higher for treatment than placebo for all three drugs. There is little evidence from direct comparisons between the three drugs. There are several economic analyses of the cost-effectiveness of these drugs, but the findings cannot be considered robust owing to inadequate data. A range of other pharmacological treatments have been tested, including selegiline, piracetam, vitamin E, Ginkgo biloba, anti-inflammatory drugs and hormone replacement therapy, but, so far, Cochrane reviews have not established the efficacy of these interventions for Alzheimer's disease. A Cochrane review of memantine shows benefits on cognitive and global function of the same order of magnitude as seen for the cholinesterase inhibitors. Memantine has been licensed in Europe for treatment of patients with moderately severe to severe Alzheimer's disease.
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Affiliation(s)
- John Grimley Evans
- Cochrane Dementia and Cognitive Improvement Group, University of Oxford, UK
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Whitehead A, Perdomo C, Pratt RD, Birks J, Wilcock GK, Evans JG. Donepezil for the symptomatic treatment of patients with mild to moderate Alzheimer's disease: a meta-analysis of individual patient data from randomised controlled trials. Int J Geriatr Psychiatry 2004; 19:624-33. [PMID: 15254918 DOI: 10.1002/gps.1133] [Citation(s) in RCA: 113] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/10/2022]
Abstract
BACKGROUND The objective was to evaluate the efficacy and tolerability of donepezil (5 and 10 mg/day) compared with placebo in alleviating manifestations of mild to moderate Alzheimer's disease (AD). METHOD A systematic review of individual patient data from Phase II and III double-blind, randomised, placebo-controlled studies of up to 24 weeks and completed by 20 December 1999. The main outcome measures were the ADAS-cog, the CIBIC-plus, and reports of adverse events. RESULTS A total of 2376 patients from ten trials were randomised to either donepezil 5 mg/day (n = 821), 10 mg/day (n = 662) or placebo (n = 893). Cognitive performance was better in patients receiving donepezil than in patients receiving placebo. At 12 weeks the differences in ADAS-cog scores were 5 mg/day-placebo: - 2.1 [95% confidence interval (CI), - 2.6 to - 1.6; p < 0.001], 10 mg/day-placebo: - 2.5 ( - 3.1 to - 2.0; p < 0.001). The corresponding results at 24 weeks were - 2.0 ( - 2.7 to - 1.3; p < 0.001) and - 3.1 ( - 3.9 to - 2.4; p < 0.001). The difference between the 5 and 10 mg/day doses was significant at 24 weeks (p = 0.005). The odds ratios (OR) of improvement on the CIBIC-plus at 12 weeks were: 5 mg/day-placebo 1.8 (1.5 to 2.1; p < 0.001), 10 mg/day-placebo 1.9 (1.5 to 2.4; p < 0.001). The corresponding values at 24 weeks were 1.9 (1.5 to 2.4; p = 0.001) and 2.1 (1.6 to 2.8; p < 0.001). Donepezil was well tolerated; adverse events were cholinergic in nature and generally of mild severity and brief in duration. CONCLUSION Donepezil (5 and 10 mg/day) provides meaningful benefits in alleviating deficits in cognitive and clinician-rated global function in AD patients relative to placebo. Increased improvements in cognition were indicated for the higher dose.
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Affiliation(s)
- Anne Whitehead
- The University of Reading, Medical and Pharmaceutical Statistics Research Unit, Reading, UK.
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Evans JG. Flesh in the Age of Reason. Clin Med (Lond) 2004. [DOI: 10.7861/clinmedicine.4-4-379a] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
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Affiliation(s)
- John Grimley Evans
- Division of Clinical Gerontology, The Radcliffe Infirmary, Oxford OX2 6HE, UK
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Cook LJ, Ho LW, Taylor AE, Brayne C, Evans JG, Xuereb J, Cairns NJ, Pritchard A, Lemmon H, Mann D, St Clair D, Turic D, Hollingworth P, Moore PJ, Jehu L, Archer N, Walter S, Foy C, Edmondson A, Powell J, Lovestone S, Owen MJ, Williams J, Lendon C, Rubinsztein DC. Candidate gene association studies of the α4 (CHRNA4) and β2 (CHRNB2) neuronal nicotinic acetylcholine receptor subunit genes in Alzheimer's disease. Neurosci Lett 2004; 358:142-6. [PMID: 15026168 DOI: 10.1016/j.neulet.2004.01.016] [Citation(s) in RCA: 33] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/10/2003] [Revised: 01/12/2004] [Accepted: 01/12/2004] [Indexed: 11/24/2022]
Abstract
Consistent deficits in the cholinergic system are evident in Alzheimer's disease (AD) patients, including selective loss of alpha4beta2 nicotinic acetylcholine receptors in the brains of AD patients. Knockout mice for the beta2 subunit have impaired neuronal survival in ageing. Accordingly, we have analysed polymorphisms in the genes that encode the alpha4 and beta2 subunits, CHRNA4 and CHRNB2 respectively, for genetic associations with late-onset AD. A significant association for disease was observed for a non-coding polymorphism in CHRNB2 (odds ratio=0.57, 95% confidence interval=0.35-0.95, P=0.024). Replication analysis was performed in two further sample sets. While these did not individually yield significant results, a significant association remained when all samples were pooled (odds ratio=0.70, 95% confidence interval=0.52-0.95, P=0.019). These data suggest that this variant warrants further examination in large case-control series.
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Affiliation(s)
- Lynnette J Cook
- Department of Medical Genetics, Cambridge Institute for Medical Research, Addenbrooke's Hospital, Hills Road, Cambridge CB2 2XY, UK
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Clarke R, Refsum H, Birks J, Evans JG, Johnston C, Sherliker P, Ueland PM, Schneede J, McPartlin J, Nexo E, Scott JM. Screening for vitamin B-12 and folate deficiency in older persons. Am J Clin Nutr 2003; 77:1241-7. [PMID: 12716678 DOI: 10.1093/ajcn/77.5.1241] [Citation(s) in RCA: 150] [Impact Index Per Article: 7.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022] Open
Abstract
BACKGROUND Vitamin B-12 deficiency is usually accompanied by elevated concentrations of serum total homocysteine (tHcy) and methylmalonic acid (MMA). Folate deficiency also results in elevated tHcy. Measurement of these metabolites can be used to screen for functional vitamin B-12 or folate deficiency. OBJECTIVE We assessed the prevalence of vitamin B-12 and folate deficiency in a population-based study (n = 1562) of older persons living in Oxford City, United Kingdom. DESIGN We postulated that, as vitamin B-12 or folate concentrations declined from adequate to impaired levels, tHcy (or MMA) concentrations would increase. Individuals were classified as being at high risk of vitamin B-12 deficiency if they had low vitamin B-12 (< 150 pmol/L) or borderline vitamin B-12 (150-200 pmol/L) accompanied by elevated MMA (> 0.35 micromol/L) or tHcy (> 15.0 micromol/L). Individuals were classified as being at high risk of folate deficiency if they had low folate (< 5 nmol/L) or borderline folate (5-7 nmol/L) accompanied by elevated tHcy (> 15 micromol/L). RESULTS Cutoffs of 15.0 micro mol/L for tHcy and 0.35 micro mol/L for MMA identified persons with normal or elevated concentrations. Among persons aged 65-74 and >or= 75 y, respectively, approximately 10% and 20% were at high risk of vitamin B-12 deficiency. About 10% and 20%, respectively, were also at high risk of folate deficiency. About 10% of persons with vitamin B-12 deficiency also had folate deficiency. CONCLUSION Use of tHcy or MMA among older persons with borderline vitamin concentrations may identify those at high risk of vitamin B-12 deficiency who should be considered for treatment.
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Affiliation(s)
- Robert Clarke
- Clinical Trial Service Unit, University of Oxford, Oxford, United Kingdom.
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Cook L, Brayne CE, Easton D, Evans JG, Xuereb J, Cairns NJ, Rubinsztein DC. No evidence for an association between Saitohin Q7R polymorphism and Alzheimer's disease. Ann Neurol 2002; 52:690-1. [PMID: 12402275 DOI: 10.1002/ana.10362] [Citation(s) in RCA: 17] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022]
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Lamb SE, Oldham JA, Morse RE, Evans JG. Neuromuscular stimulation of the quadriceps muscle after hip fracture: a randomized controlled trial. Arch Phys Med Rehabil 2002; 83:1087-92. [PMID: 12161829 DOI: 10.1053/apmr.2002.33645] [Citation(s) in RCA: 46] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Abstract
OBJECTIVE To study the feasibility and effect of neuromuscular stimulation on recovery of mobility after surgical fixation for hip fracture. DESIGN Double-blind study with stratified randomization. SETTING Home-based rehabilitation program. PARTICIPANTS Twenty-four women over the age of 75 years with hip fracture. INTERVENTIONS Neuromuscular or placebo stimulation of the quadriceps muscle of the fractured leg, applied for 3 hours a day, for 6 weeks, commencing 1 week after surgery. MAIN OUTCOME MEASURES Recovery of walking speed and ability, postural stability, lower-limb muscle power, and pain at 7 and 13 weeks after surgery. RESULTS Women in the neuromuscular stimulation group showed faster recovery of mobility. Of the women receiving stimulation, 9 of 12 recovered their prior levels of indoor mobility ability by 13 weeks compared with 3 of 12 in the placebo group (Fisher exact test, P=.046). There were no differences in recovery of walking speed in the first 7 weeks, but women in the stimulation group had greater recovery between 7 and 13 weeks (mean difference=-.13m/s; 95% confidence interval, -.23 to -.01). CONCLUSIONS Neuromuscular stimulation at home is feasible and may be effective in speeding recovery of mobility after surgical fixation of hip fracture.
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Affiliation(s)
- Sarah E Lamb
- Interdisciplinary Research Centre in Health, Coventry University, UK.
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Affiliation(s)
- James D Price
- Division of Clinical Geratology, Nuffield Department of Clinical Medicine, University of Oxford, Radcliffe Infirmary, Oxford OX2 6HE, UK
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Price JD, Grimley Evans J. An N-of-1 randomized controlled trial ('N-of-1 trial') of donepezil in the treatment of non-progressive amnestic syndrome. Age Ageing 2002; 31:307-9. [PMID: 12147570 DOI: 10.1093/ageing/31.4.307] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022] Open
Abstract
INTRODUCTION a professional man sustained a residual, persisting, isolated impairment of short-term memory secondary to severe carbon monoxide poisoning. Informal, open trial of the cholinesterase inhibitor donepezil resulted in uncertain benefit. PROTOCOL an N-of-1 randomized, double-blind controlled trial of donepezil against placebo. Placebo-induced headache permitted evaluation of donepezil at only the 5 mg dose. RESULTS there was no improvement in short-term memory. CONCLUSION the trial excluded significant benefit of donepezil 5 mg in this patient, preventing long-term unnecessary prescription. Beneficial effects in other similar patients or at higher dosage cannot be excluded.
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Affiliation(s)
- James D Price
- Division of Clinical Geratology, Nuffield Department of Clinical Medicine, University of Oxford, Radcliffe Infirmary, Oxford OX2 6HE, UK.
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Lake BG, Evans JG, Chapuis F, Walters DG, Price RJ. Studies on the disposition, metabolism and hepatotoxicity of coumarin in the rat and Syrian hamster. Food Chem Toxicol 2002; 40:809-23. [PMID: 11983276 DOI: 10.1016/s0278-6915(02)00036-4] [Citation(s) in RCA: 27] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/27/2022]
Abstract
The hepatotoxicity, metabolism and disposition of coumarin has been compared in male Sprague-Dawley rats and Syrian hamsters. The treatment of rats for 12, 24 and 42 weeks with diets containing 0.2 and 0.5% coumarin resulted in hepatotoxicity and increased relative liver weights. While levels of cytochrome P450 (CYP) and CYP-dependent enzymes were decreased, levels of reduced glutathione (GSH) and activities of UDP glucuronosyltransferase, gamma-glutamyltransferase and GSH S-transferase were increased. In contrast, coumarin produced few hepatic changes in the Syrian hamster. Following a single oral dose of 25 mg/kg [3-14C]coumarin, radioactivity was rapidly excreted by the rat and Syrian hamster with the urine containing 63.5 and 89.9%, respectively, and the faeces 38.0 and 12.4%, respectively, of the administered dose after 96 h. The biliary excretion of radioactivity was greater in the rat than in the Syrian hamster. Analysis of 0-24-h urine samples revealed that both species were poor 7-hydroxylators of coumarin. In the rat, treatment with 0.5% coumarin in the diet for 24 weeks was found to increase the urinary excretion of single oral gavage doses of 25 and 300 mg/kg [3-14C]coumarin. The marked species difference in hepatotoxicity between the rat and Syrian hamster observed in this study may be at least partially attributable to differences in coumarin disposition. However, additional studies are required to elucidate the metabolic pathways of coumarin in both species.
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Affiliation(s)
- B G Lake
- TNO BIBRA International Ltd, Woodmansterne Road, Carshalton, Surrey SM5 4DS, UK.
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Abstract
That people should only be enrolled in medical research if they have given free and informed consent is now an unquestioned principle of research ethics. It is however a recent innovation. Prior to the prominence given to consent to participation in research in the condemnation of German doctors arraigned at Nuremberg in 1945, informed consent had appeared in American litigation, but only as an issue in clinical malpractice suits. Informed consent as an ethical requirement in medical research had arisen in some earlier European contexts. Despite the Nuremberg judgement, informed consent by participants in research was not widely recognised as ethically mandatory until the early 1970s. This delay seems to have been due in part to scepticism about the practicability of truly informed consent, but medical paternalism and the circumstances surrounding military research during the Cold War period may have contributed.
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Affiliation(s)
- John Grimley Evans
- Department of Clinical Geratology, Radcliffe Infirmary, University of Oxford.
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Affiliation(s)
- John Grimley Evans
- Nuffield Department of Clinical Medicine, Division of Clinical Geratology, The Radcliffe Infirmary, Oxford OX2 6HE, UK.
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Taylor A, Ezquerra M, Bagri G, Yip A, Goumidi L, Cottel D, Easton D, Evans JG, Xuereb J, Cairns NJ, Amouyel P, Chartier-Harlin MC, Brayne C, Rubinsztein DC. Alzheimer disease is not associated with polymorphisms in the angiotensinogen and renin genes. Am J Med Genet 2001; 105:761-4. [PMID: 11803527 DOI: 10.1002/ajmg.10044] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
Abstract
Hypertension has been implicated as a risk factor for Alzheimer disease (AD) and dementia in epidemiological studies of humans. It is thus possible that there are common genetic determinants for hypertension and AD. Epidemiological, clinical, and experimental data suggest that the renin-angiotensin-aldosterone system is a critical regulator of blood pressure. The presence of an MboI site in an RFLP in the renin gene and the Thr at the Met/Thr polymorphism at codon 235 (M235T) of the angiotensinogen gene have been reported to be associated with hypertension. These variants were studied in autopsy-confirmed AD cases and matched controls from the U.K. While no association was detected with the renin polymorphism, a weak deleterious effect was observed in cases homozygous for the angiotensinogen Thr allele. However, this association was not observed in a French cohort of clinically diagnosed AD cases and controls, suggesting that the initial observation was a type I error. Thus, these polymorphisms are unlikely to be associated with AD risk.
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Affiliation(s)
- A Taylor
- Department of Medical Genetics, Wellcome Trust Centre for Molecular Mechanisms in Disease, Cambridge Institute for Medical Research, Addenbrooke's Hospital, Cambridge, UK
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Evans JG, Dirks SJ. Relationships of admissions data and measurements of psychological constructs with psychomotor performance of dental technology students. J Dent Educ 2001; 65:874-82. [PMID: 11569603] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/21/2023]
Abstract
Abstract: The psychomotor skills required in dental laboratory technology and dentistry are similar. Dental educators have recognized the problems in selecting from among dental school applicants those with potential psychomotor skills. The purpose of this study was to examine the relationships of admissions data and measurements of psychological constructs of dental technology students with their psychomotor performance in first-semester dental laboratory courses. The dependent variables selected for the study were grades from three laboratory courses. Significant positive correlations (p<.05) were noted between all laboratory grades and previous college hours, previous college GPA, interview scores, field dependence-independence scores, block counting, trust, straightforwardness, and dutifulness. These data indicate that individual differentiation in learning ability, visual or spatial perception, and personality do affect psychomotor learning and should be taken into consideration in the design and execution of teaching and training curricula.
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Affiliation(s)
- J G Evans
- Department of Dental Technology Education, School of Allied Health Sciences, The University of Texas Health Science Center, San Antonio 78284-7902, USA.
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Taylor AE, Yip A, Brayne C, Easton D, Evans JG, Xuereb J, Cairns N, Esiri MM, Rubinsztein DC. Genetic association of an LBP-1c/CP2/LSF gene polymorphism with late onset Alzheimer's disease. J Med Genet 2001; 38:232-3. [PMID: 11283204 PMCID: PMC1734850 DOI: 10.1136/jmg.38.4.232] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/04/2022]
Abstract
OBJECTIVES The only locus unequivocally associated with late onset Alzheimer's disease (AD) risk is APOE. However, this locus accounts for less than half the genetic variance. A recent study suggested that the A allele of the 3'UTR biallelic polymorphism in the LBP-1c/CP2/LSF gene was associated with reduced AD risk. Samples were diagnosed predominantly by clinical rather than pathological criteria. We have sought to replicate this finding in a series of necropsy confirmed, late onset AD cases and non-demented controls. METHODS The 3'UTR polymorphism in the LBP-1c/CP2/LSF gene was typed in 216 necropsy confirmed AD cases and 301 non-demented controls aged >73 years. RESULTS We found different LBP-1c/CP2/LSF allele distributions in our AD cases and controls (p=0.048); the A allele was associated with reduced AD risk. The allele and genotype frequencies observed in our cases and controls were similar to those previously reported. No significant effects emerged when the data were adjusted for age, sex, or apoE epsilon4 carrier status. CONCLUSIONS Our data support LBP-1c/CP2/LSF as a candidate gene/risk factor for AD and provide justification for future studies to investigate the role of this gene in Alzheimer's disease.
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Affiliation(s)
- A E Taylor
- Department of Medical Genetics, Wellcome Trust Centre for Molecular Mechanisms in Disease, Cambridge Institute for Medical Research, Wellcome/MRC Building, Addenbrooke's Hospital, Hills Road, Cambridge CB2 2XY, UK
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Murphy T, Yip A, Brayne C, Easton D, Evans JG, Xuereb J, Cairns N, Esiri MM, Rubinsztein DC. The BACE gene: genomic structure and candidate gene study in late-onset Alzheimer's disease. Neuroreport 2001; 12:631-4. [PMID: 11234778 DOI: 10.1097/00001756-200103050-00040] [Citation(s) in RCA: 34] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
Abstract
Alzheimer's disease (AD) pathology is characterized by beta-amyloid plaques and neurofibrillary tangles. Studies of autosomal dominant early-onset AD mutations suggest that beta-amyloid overproduction is sufficient to cause AD. Recently, the BACE gene, which encodes beta-secretase, the rate limiting enzyme in beta-amyloid formation, has been identified. Since this gene is a strong candidate gene for late-onset AD because of its function, we have characterized its genomic organization and identified two polymorphisms. Neither of these polymorphisms were associated with AD risk in genetic association studies comparing autopsy-confirmed late-onset AD cases and age-matched non-demented controls. Thus, we find no evidence that this locus influences risk for late-onset AD.
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Affiliation(s)
- T Murphy
- Department of Medical Genetics, Wellcome Trust Centre for Molecular Mechanisms in Disease, Cambridge Institute for Medical Research, UK
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Evans JG. Supportive ventilation on a geriatric ward: better, but is it the best? Aging (Milano) 2001; 13:1-2. [PMID: 11292145 DOI: 10.1007/bf03351485] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 10/25/2022]
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Daggett P, Jackson P, Evans JG. Modern doctoring. Clin Med (Lond) 2001. [DOI: 10.7861/clinmedicine.1-1-82] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
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Brown P, McNeilly JR, Evans JG, Crawford GM, Walker M, Christian HC, McNeilly AS. Manipulating the in vivo mRNA expression profile of FSH beta to resemble that of LH beta does not promote a concomitant increase in intracellular storage of follicle-stimulating hormone. J Neuroendocrinol 2001; 13:50-62. [PMID: 11123515 DOI: 10.1046/j.1365-2826.2001.00594.x] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
The beta-subunits of luteinizing hormone (LH beta) and follicle-stimulating hormone (FSH beta) are differentially expressed, and this may contribute to the unique expression and storage patterns of LH and FSH. Therefore, to determine if the in vivo expression profile of FSH beta could be altered to that of LH beta, a truncated ovine FSH beta (oFSH beta) gene, which would encode a mRNA lacking the putative destabilizing 3' untranslated region, was fused downstream of the ovine LH beta (oLH beta) promoter and expressed in transgenic mice. In two independent lines, line 16 and 17, we measured oFSH beta, mouse LH beta (mLHbeta) and mouse FSH beta (mFSH beta) mRNA levels: (i) after castration in males; (ii) after administering inhibin to ovariectomized mice; and (iii) during the oestrous cycle. In each experiment, the expression profile of oFSH beta mRNA mimicked mLH beta and not mFSH beta mRNA. In addition, after actinomycin D treatment of pituitary cultures, while mFSH beta mRNA did decay, there was no measurable decay of the oFSH beta mRNA transcript. These differences increased total FSH beta steady-state mRNA expression levels in male transgenics. However, there was no detectable increase in pituitary FSH by either radioimmunoassay or western blotting analysis of pituitary extracts. Subsequent analysis revealed that pituitary FSH beta in line 16 was heavily glycosylated; in contrast, pituitary FSH beta in line 17 was largely unmodified. These differences in post-translational modification of the beta-subunit, and the lack of intracellular storage, contributed to increased plasma FSH levels and ovulation rate in line 16, but not line 17. In conclusion, the expression profile of oFSH beta mRNA was manipulated to mimic mLH beta mRNA and this increased FSH beta mRNA expression levels, but did not increase storage of FSH. This suggests that, regardless of the levels of synthesis, post-translational sorting preferentially promotes FSH secretion from the pituitary.
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Affiliation(s)
- P Brown
- MRC Human Reproductive Sciences Unit, Centre for Reproductive Biology, Edinburgh, UK.
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