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Besant P, Attwood P, Piggott M. Focus on Phosphoarginine and Phospholysine. Curr Protein Pept Sci 2009; 10:536-50. [DOI: 10.2174/138920309789630598] [Citation(s) in RCA: 76] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/24/2008] [Accepted: 04/22/2009] [Indexed: 11/22/2022]
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Thomas AJ, Hendriksen M, Piggott M, Ferrier IN, Perry E, Ince P, O'Brien JT. A study of the serotonin transporter in the prefrontal cortex in late-life depression and Alzheimer's disease with and without depression. Neuropathol Appl Neurobiol 2006; 32:296-303. [PMID: 16640648 DOI: 10.1111/j.1365-2990.2006.00728.x] [Citation(s) in RCA: 42] [Impact Index Per Article: 2.3] [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: 11/29/2022]
Abstract
Previous studies investigating the serotonin transporter (SERT) in depression have been inconsistent and included a large proportion of subjects who had committed suicide. In Alzheimer's disease studies have generally reported a reduction in SERT density but have not compared Alzheimer's disease subjects with and without comorbid major depression. We conducted a post mortem study of SERT density in the prefrontal cortex in normal elderly, a group of elderly depressed subjects and in Alzheimer's disease subjects with and without major depression. A post mortem study comparing SERT density in the prefrontal cortex in elderly controls (n = 10), subjects with major depression (n = 8) and subjects with Alzheimer's disease with (n = 9) and without (n = 5) comorbid major depression. We used autoradiography to measure the density of [3H]CN-IMI binding (non-specific binding determined with citalopram) to the SERT in the prefrontal cortex. We found a marked reduction in specific SERT binding in the prefrontal cortex in Alzheimer's disease subjects compared with both control (P = 0.002) and depressed subjects (P = 0.004) but no difference in SERT binding between depressed and control subjects or between Alzheimer's disease subjects with and without depression. Our study confirms previous reports of a reduction in SERT binding in Alzheimer's disease but indicates this reduction is not greater in Alzheimer's disease subjects who also have had major depression. In a group of subjects more typical of late-life depression we did not identify any alterations in SERT density.
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Affiliation(s)
- A J Thomas
- School of Neurology, Neurobiology and Psychiatry, University of Newcastle upon Tyne, Newcastle upon Tyne, UK.
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Lewis H, Beher D, Cookson N, Oakley A, Piggott M, Morris CM, Jaros E, Perry R, Ince P, Kenny RA, Ballard CG, Shearman MS, Kalaria RN. Quantification of Alzheimer pathology in ageing and dementia: age-related accumulation of amyloid-beta(42) peptide in vascular dementia. Neuropathol Appl Neurobiol 2006; 32:103-18. [PMID: 16599940 DOI: 10.1111/j.1365-2990.2006.00696.x] [Citation(s) in RCA: 112] [Impact Index Per Article: 6.2] [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: 12/31/2022]
Abstract
Clinicopathological observations suggest there is considerable overlap between vascular dementia (VaD) and Alzheimer's disease (AD). We used immunochemical methods to compare quantities of amyloid-beta (Abeta) peptides in post mortem brain samples from VaD, AD subjects and nondemented ageing controls. Total Abeta peptides extracted from temporal and frontal cortices were quantified using a previously characterized sensitive homogenous time-resolved fluorescence (HTRF) assay. The HTRF assays and immunocapture mass spectrometric analyses revealed that the Abeta(42) species were by far the predominant form of extractable peptide compared with Abeta(40) peptide in VaD brains. The strong signal intensity for the peak representing Abeta(4-42) peptide confirmed that these N-terminally truncated species are relatively abundant. Absolute quantification by HTRF assay showed that the mean amount of total Abeta(42) recovered from VaD samples was approximately 50% of that in AD, and twice that in the age-matched controls. Linear correlation analysis further revealed an increased accumulation with age of both Abeta peptides in brains of VaD subjects and controls. Interestingly, VaD patients surviving beyond 80 years of age exhibited comparable Abeta(42) concentrations with those in AD in the temporal cortex. Our findings suggest that brain Abeta accumulates increasingly with age in VaD subjects more so than in elderly without cerebrovascular disease and support the notion that they acquire Alzheimer-like pathology in older age.
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Affiliation(s)
- H Lewis
- Department of Molecular & Cellular Neuroscience, Merck, Sharp & Dohme Research Laboratories, Terlings Park, Essex
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Pimlott SL, Piggott M, Owens J, Greally E, Court JA, Jaros E, Perry RH, Perry EK, Wyper D. Nicotinic acetylcholine receptor distribution in Alzheimer's disease, dementia with Lewy bodies, Parkinson's disease, and vascular dementia: in vitro binding study using 5-[(125)i]-a-85380. Neuropsychopharmacology 2004; 29:108-16. [PMID: 12955099 DOI: 10.1038/sj.npp.1300302] [Citation(s) in RCA: 122] [Impact Index Per Article: 6.1] [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: 12/19/2022]
Abstract
Nicotinic acetylcholine receptors (nAChRs) have been implicated in a number of neurological disorders. 5-Iodo-3-[2(S)-2-azetidinylmethoxy]pyridine (5-I-A-85380) is a novel nAChR marker, binding predominantly to the alpha4beta2 subtype. This in vitro autoradiography study describes the distribution of 5-[(125)I]-A-85380 binding in post-mortem brain tissue from normal elderly individuals and from cases with age-associated dementias of both neurodegenerative and vascular types. The binding distribution of 5-[(125)I]-A-85380 in normal brain tissue was found to be consistent with the reported distribution of other high-affinity nicotinic ligands. In addition to high thalamic and moderate striatal and temporal cortex density, moderate 5-[(125)I]-A-85380 binding was also seen in white matter tracts in cingulate, occipital, and temporal areas, indicating the presence of nAChRs along nerve fiber tracts, which has not been reported in other high-affinity nicotinic agonist distribution studies. In Parkinson's disease (PD), loss of striatal 5-[(125)I]-A-85380 binding closely parallels the loss of nigrostriatal dopaminergic markers previously observed. In dementia with Lewy bodies (DLB) reduced striatal 5-[(125)I]-A-85380 binding density, comparable to that in PD, may be a marker of early degeneration in nigrostriatal inputs, while in Alzheimer's disease (AD) reduced striatal 5-[(125)I]-A-85380 binding could be related to reduced cortical inputs. The reductions of nAChRs seen in AD, DLB, and PD were not apparent in vascular dementia (VaD). In conclusion, 5-I-A-85380 is clearly a useful ligand for both in vitro and in vivo single photon emission tomography human studies investigating disease symptoms and progression, response to acetylcholinesterase-inhibiting drugs and in differentiating primary degenerative dementia from VaD.
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Affiliation(s)
- S L Pimlott
- West of Scotland Radionuclide Dispensary, North Glasgow University Hospitals NHS Trust, Western Infirmary, Glasgow, UK.
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Abstract
BACKGROUND In 1996, the CONSORT (CONsolidated Standards Of Reporting Trials) statement for the reporting of clinical trials was produced, based on empirical evidence regarding bias. AIMS This study assessed the quality of reporting of randomized controlled trials (RCTs) in the palliative care literature. METHODS Three specialist journals were hand searched for RCTs. A checklist was devised based on CONSORT recommendations. Two investigators independently assessed all the trials against this checklist. The trials were grouped into time cohorts of five years and quality comparisons made. Trials looking at pain were compared with those trials looking at other aspects of palliative care. RESULTS Ninety-three RCTs were identified. The number of trials has increased over time: nine in the first cohort, 37 in the second and 47 in the last cohort. The number of patients in the individual trials has also increased over time. Generally, the reporting quality was poor, particularly the areas of allocation concealment, randomization technique and intention to treat analysis, where there is empirical evidence, that it leads to trial bias. Although there were more pain papers than non-pain papers, the quality of reporting was only better for blinding and intention to treat analysis. CONCLUSION The quality of reporting of RCTs in the palliative care literature is generally poor. However, there has been an increase in the number and the size of RCTs being carried out. This shows recognition of the importance of an evidence base in palliative care. However, in order to guide clinical decision making, future trials need to improve the quality of their reporting by adhering to the CONSORT statement.
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Affiliation(s)
- M Piggott
- Barts and the London NHS Trust, London, UK
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Martin-Ruiz C, Lawrence S, Piggott M, Kuryatov A, Lindstrom J, Gotti C, Cookson MR, Perry RH, Jaros E, Perry EK, Court JA. Nicotinic receptors in the putamen of patients with dementia with Lewy bodies and Parkinson's disease: relation to changes in alpha-synuclein expression. Neurosci Lett 2002; 335:134-8. [PMID: 12459516 DOI: 10.1016/s0304-3940(02)01183-7] [Citation(s) in RCA: 20] [Impact Index Per Article: 0.9] [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: 11/20/2022]
Abstract
A reduction in nicotinic receptor (nAChR) binding has previously been observed in putamen in Parkinson's disease (PD) and dementia with Lewy bodies (DLB). The present study demonstrates no concommitant reduction in the expression of alpha2-alpha7, beta2 and beta3 nAChR subunit proteins. Alphasynuclein, which can interfere with membrane protein function and is a key constituent of PD and DLB pathology, was increased (insoluble fraction) in both disorders, although nAChR binding loss did not correlate with alpha-synuclein expression within patient groups. The results point to a possible abnormality of striatal nicotinic receptor assembly in PD and DLB.
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Affiliation(s)
- C Martin-Ruiz
- Joint MRC-Newcastle University Centre Development for Clinical Brain Aging, MRC Building, Newcastle General Hospital, Westgate Road, NE4 6BE, Newcastle upon Tyne, UK
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Marutle A, Zhang X, Court J, Piggott M, Johnson M, Perry R, Perry E, Nordberg A. Laminar distribution of nicotinic receptor subtypes in cortical regions in schizophrenia. J Chem Neuroanat 2001; 22:115-26. [PMID: 11470559 DOI: 10.1016/s0891-0618(01)00117-x] [Citation(s) in RCA: 144] [Impact Index Per Article: 6.3] [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: 11/17/2022]
Abstract
The laminar cortical distribution of the [125I]alpha-bungarotoxin, [3H]cytisine and [3H]epibatidine nicotinic acetylcholine receptor ligands was investigated by quantitative autoradiography in autopsy tissue from the cingulate, orbitofrontal and temporal cortices of control and schizophrenia subjects matched for age and smoking history. Different laminar binding patterns were observed for the various nicotinic ligands both in schizophrenic and control brains. [125I]alpha-Bungarotoxin binding was distributed homogeneously across all cortical layers in all three brain regions, with highest binding densities in the cingulate cortex. [3H]Cytisine and [3H]epibatidine binding varied across the cortical ribbon, with high binding in layers I, III, V and VI, within the three cortical regions. A significantly reduced [125I] alpha-bungarotoxin binding (-54%) was observed in the cingulate cortex of schizophrenia subjects, in comparison with normal individuals who smoked tobacco. In the same brain region also a significantly higher [3H]cytisine binding (48-77%) was observed in nearly all layers, except for layer I of the schizophrenia subjects, when compared to normal individuals with a history of tobacco use. No significant changes in [3H]epibatidine binding was observed within the individual cortical layers between control subjects and patients with schizophrenia, but when calculated as a whole region (i.e. measurements performed across the whole cortical ribbon), the temporal cortex showed a significant increase in [3H]epibatidine binding in schizophrenia subjects compared to control subjects. The results suggest opposite changes of the alpha4beta2 and alpha7 nicotinic receptor subtypes in the cingulate cortex of patients with schizophrenia which might reflect involvement of two different nicotinic receptor mechanisms in schizophrenia brain.
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Affiliation(s)
- A Marutle
- Karolinska Institutet, Department of Clinical Neuroscience, Occupational Therapy and Elderly Care Research (NEUROTEC), Division of Molecular Neuropharmacology, Huddinge University Hospital, B84, S-141 86, Stockholm, Sweden
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Martin-Ruiz C, Court J, Lee M, Piggott M, Johnson M, Ballard C, Kalaria R, Perry R, Perry E. Nicotinic receptors in dementia of Alzheimer, Lewy body and vascular types. Acta Neurol Scand Suppl 2001; 176:34-41. [PMID: 11261803 DOI: 10.1034/j.1600-0404.2000.00305.x] [Citation(s) in RCA: 47] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
Abstract
OBJECTIVES Comparisons were made of nicotinic receptors in 3 major forms of dementia in old age. Although it is well established the involvement of nicotinic receptors in Alzheimer's disease (AD), their status in the other two main causes of dementia in old age-dementia with Lewy bodies (DLB) and vascular dementia (VaD) is not widely reported. METHODS Temporal cortex was examined for epibatidine and alpha-bungarotoxin binding, and immunoreactivity of alpha4 and alpha7 nAChR subunits. RESULTS There were selective abnormalities in nicotinic receptor subtypes in the disorders examined. In AD there is a loss of high affinity receptor binding, reflecting a selective loss of alpha4 subunit, but no change in alpha7 subunits. Similar abnormalities in ligand binding are also apparent in DLB. In the VaD series, there was no overall loss of epibatidine binding or immunoreactivity for alpha4 or alpha7 subunits. CONCLUSIONS Loss of cortical receptor alpha4 subunit appears to be a characteristic feature of neurodegenerative dementia but not dementia of vascular origin. Since nicotinic receptors control cerebral vasodilation, the relative integrity of the receptors in VaD may auger well for nicotinic therapy in this disorder in which there is a cholinergic abnormality, to judge by the loss of the presynaptic enzyme.
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Affiliation(s)
- C Martin-Ruiz
- Joint MRC-Newcastle University Development in Clinical Brain Aging, Newcastle General Hospital, Newcastle upon Tyne, UK
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Abstract
Loss of cortical nicotinic acetylcholine receptors with high affinity for agonists (20-50%) in patients with Alzheimer's disease is a common finding. Recent immunochemical analyses indicate that this deficit is predominantly associated with the loss of alpha4 subunits (30-50%), although modest reductions of alpha3 may occur in some individuals (25-29%). No reduction of beta2 subunit protein expression or levels of alpha3 and alpha4 messenger RNA has been reported. Decline in cortical [(125)I]alpha-bungarotoxin binding and alpha7 protein expression does not appear to be as extensive or widespread as the loss of alpha4 (0-40%), with no reduction in messenger RNA expression. In the thalamus, there was a trend for reduced [(3)H]nicotine binding in the majority of nuclei (0-20%) in Alzheimer's disease; however, there was a significant decline in [(125)I]alpha-bungarotoxin binding in the reticular nucleus. In the striatum [(3)H]nicotine binding was reduced in Alzheimer's disease, and although neuroleptic medication accentuated this change, it occurred in those free of neuroleptics. Changes in nicotinic acetylcholine receptors in Alzheimer's disease are distinct from those in normal aging and are likely to contribute to clinical features and possibly neuropathology.
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Affiliation(s)
- J Court
- Joint MRC Newcastle University Centre Development in Clinical Brain Aging, Institute for the Health of the Elderly, Newcastle General Hospital, Newcastle upon Tyne, United Kingdom
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Ballard C, Piggott M, Johnson M, Cairns N, Perry R, McKeith I, Jaros E, O'Brien J, Holmes C, Perry E. Delusions associated with elevated muscarinic binding in dementia with Lewy bodies. Ann Neurol 2000; 48:868-76. [PMID: 11117543] [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: 02/18/2023]
Abstract
The relation between disturbances of cholinergic neurotransmission and delusions (DELs) has not been investigated in degenerative dementias such as dementia with Lewy bodies (DLB). A cohort of dementia patients were assessed with standardized clinical evaluations (including the Columbia University Scale for Psychopathology in Alzheimer's Disease), which were repeated annually until death. DLB was confirmed neuropathologically in 21 patients. Neurochemical evaluation included M1 receptor autoradiography (pirenzepine binding), biochemical measurement of choline acetyltransferase (ChAT), and acetylcholinesterase (AChE) histochemistry in brain regions hypothesized to be involved in the genesis of psychosis. Compared with 11 age-matched controls, CHAT and pirenzepine levels were most extensively reduced in the temporal and parietal neocortex of DLB patients. In Brodmann area 36, DELs were significantly associated with elevated pirenzepine binding (131.0 vs 93.5, t = 2.7), whereas visual hallucinations were associated with significant reductions in ChAT (1.7 vs 2.5, t = 2.5). There were no significant associations with other areas or with cholinesterase. Although DELs and visual hallucinations were both linked with disturbances in cholinergic neurotransmission, the nature of the associations was different. Upregulation of the postsynaptic muscarinic receptor may be central in the genesis of DELs, with important treatment implications.
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Affiliation(s)
- C Ballard
- Institute for the Health of the Elderly, Wolfson Research Centre, Newcastle General Hospital, United Kingdom
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Piggott M, Farrugia D, Otite U, Oliver RT, Crake T. Renal cell carcinoma presenting with cardiac failure. Hosp Med 2000; 61:804-5. [PMID: 11198754] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 02/19/2023]
Affiliation(s)
- M Piggott
- Department of Medical Oncology, St Bartholomew's Hospital, London
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Martin-Ruiz CM, Piggott M, Gotti C, Lindstrom J, Mendelow AD, Siddique MS, Perry RH, Perry EK, Court JA. Alpha and beta nicotinic acetylcholine receptors subunits and synaptophysin in putamen from Parkinson's disease. Neuropharmacology 2000; 39:2830-9. [PMID: 11044753 DOI: 10.1016/s0028-3908(00)00110-6] [Citation(s) in RCA: 32] [Impact Index Per Article: 1.3] [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: 11/28/2022]
Abstract
It is well established that nicotinic receptors in the mammalian striatum are involved in modulation of the release of several neurotransmitters, including dopamine. In addition, nicotinic receptors with high affinity for agonists have generally been found to be reduced in the striatum in Parkinson's disease. In the present study antibodies have been used to examine which subunits contribute to the striatal nicotinic receptor loss in Parkinson's disease, and whether the reduction in [(3)H]nicotine binding correlates with synaptic loss. Autopsy tissue from the putamen of 12 Parkinson's disease cases and 12 age-matched control subjects was analysed by immunoblotting using antibodies against recombinant peptides specific for alpha3, alpha4, alpha7, beta2 and beta4 nicotinic acetylcholine receptor (nAChR) subunits and the synaptic marker synaptophysin, in conjunction with assessment of [(3)H]nicotine binding by autoradiography. The data indicate that there is no loss of alpha3, alpha4, alpha7 and beta2 immunoreactivity in the putamen in Parkinson's disease, despite a highly significant reduction in [(3)H]nicotine binding. An intense signal of beta4 immunoreactivity was found in human dorsal root ganglia, but not in temporal cortex or putamen samples. Synaptophysin immunoreactivities were also similar in Parkinson's disease and control cases. These results suggest that the loss of nicotine binding in the putamen in Parkinson's disease may involve an nAChR subunit (e.g., alpha5 and/or alpha6) other than those investigated. Alternatively, the results could reflect impaired subunit assembly at the plasma membrane.
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Affiliation(s)
- C M Martin-Ruiz
- Joint MRC Newcastle University Centre Development for Clinical Brain Aging, MRC Building, Newcastle General Hospital, Westgate Road, NE4 6BE, Newcastle upon Tyne, UK
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Perry E, Martin-Ruiz C, Lee M, Griffiths M, Johnson M, Piggott M, Haroutunian V, Buxbaum JD, Nãsland J, Davis K, Gotti C, Clementi F, Tzartos S, Cohen O, Soreq H, Jaros E, Perry R, Ballard C, McKeith I, Court J. Nicotinic receptor subtypes in human brain ageing, Alzheimer and Lewy body diseases. Eur J Pharmacol 2000; 393:215-22. [PMID: 10771016 DOI: 10.1016/s0014-2999(00)00064-9] [Citation(s) in RCA: 150] [Impact Index Per Article: 6.3] [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: 11/18/2022]
Abstract
Human brain ageing is associated with reductions in a variety of nicotinic receptors subtypes, whereas changes in age-related disorders including Alzheimer's disease or Parkinson's disease are more selective. In Alzheimer's disease, in the cortex there is a selective loss of the alpha4 (but not alpha3 or 7) subunit immunoreactivity and of nicotine or epibatidine binding but not alpha-bungarotoxin binding. Epibatidine binding is inversely correlated with clinical dementia ratings and with the level of Abeta1-42, but not related to plaque or tangle densities. In contrast, alpha-bungarotoxin binding is positively correlated with plaque densities in the entorhinal cortex. In human temporal cortex loss of acetylcholinesterase catalytic activity is positively correlated with decreased epibatidine binding and in a transgenic mouse model over expressing acetylcholinesterase, epibatidine binding is elevated. In Parkinson's disease, loss of striatal nicotine binding appears to occur early but is not associated with a loss of alpha4 subunit immunoreactivity. Tobacco use in normal elderly individuals is associated with increased alpha4 immunoreactivity in the cortex and lower densities of amyloid-beta plaques, and with greater numbers of dopaminergic neurons in the substantia nigra pars compacta. These findings indicate an early involvement of the alpha4 subunit in beta-amyloidosis but not in nigro-striatal dopaminergic degeneration.
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Affiliation(s)
- E Perry
- Department of Neuropathology, MRC Neurochemical Pathology Unit, Newcastle General Hospital, Westgate Road, Newcastle, UK.
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Perry E, Court J, Goodchild R, Griffiths M, Jaros E, Johnson M, Lloyd S, Piggott M, Spurden D, Ballard C, McKeith I, Perry R. Clinical neurochemistry: developments in dementia research based on brain bank material. J Neural Transm (Vienna) 1998; 105:915-33. [PMID: 9869326 DOI: 10.1007/s007020050102] [Citation(s) in RCA: 57] [Impact Index Per Article: 2.2] [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: 10/28/2022]
Abstract
Brain tissue obtained at autopsy continues to provide unique opportunities in current dementia research. Not only is tissue analysis still essential for diagnosis, but investigation of neurochemical pathology, at a level of resolution beyond current in vivo imaging, continues to provide new insights into the involvement of neurotransmitter signalling systems. These are relevant to therapy which, with respect to symptoms such as cognitive impairment, psychosis and depression, is currently targeted to specific transmitter (cholinergic, dopaminergic and serotonergic) systems. This paper focuses on dopaminergic, cholinergic and histaminergic parameters in Alzheimer's disease (AD), Dementia with Lewy bodies (DLB) and Parkinson's disease (PD). In the normal striatum the dopamine transporter and D2 receptor exhibit distinct rostral-caudal distributions and D2 binding is affected by genetic polymorphism at the Taq 1A locus. The transporter is reduced in both DLB and PD but not AD, correlating with severity of extrapyramidal dysfunction, and receptor abnormalities are apparent in DLB patients responding adversely to neuroleptics. Striatal nicotine receptors are lost in all 3 disorders, further reduced as a result of neuroleptic medication, and elevated as a result of tobacco use. In the thalamus there are selective reductions in presynaptic cholinergic activity in DLB in the reticular nucleus which relate to symptoms of hallucinations and fluctuating consciousness prevalent in this disorder. In the hippocampus coupling of muscarinic M1 receptors, relevant to response to cholinergic therapy, is impaired in areas most affected by beta-amyloid plaques and intact in less affected areas. Analysis of histamine H2 receptors indicates that, despite presynaptic histamine abnormalities in AD, receptor numbers are normal. Such clinically and therapeutically relevant observations on human brain neurochemistry provide a basis for improving therapeutic strategies and prospects of diagnostic in vivo chemical imaging.
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Affiliation(s)
- E Perry
- Medical Research Council Neurochemical Pathology Unit, Newcastle General Hospital, Newcastle upon Tyne, United Kingdom
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Thompson J, Thomas N, Singleton A, Piggott M, Lloyd S, Perry EK, Morris CM, Perry RH, Ferrier IN, Court JA. D2 dopamine receptor gene (DRD2) Taq1 A polymorphism: reduced dopamine D2 receptor binding in the human striatum associated with the A1 allele. Pharmacogenetics 1997; 7:479-84. [PMID: 9429233 DOI: 10.1097/00008571-199712000-00006] [Citation(s) in RCA: 420] [Impact Index Per Article: 15.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/05/2023]
Abstract
The relationship between a dopamine D2 receptor genetic polymorphism at the Taq1 A locus and the level of D2 receptor binding was investigated in normal, middle aged to elderly subjects with no psychiatric or neurological disorders. D2 receptor binding was measured by autoradiography in the caudate, putamen and nucleus accumbens, using the specific D2 receptor ligand [3H]-raclopride. In a sample of 44 individuals, only one was homozygous for the A1 allele, 25 were homozygous for A2 and 18 were heterozygotes. The presence of one or two A1 alleles was associated with reduced D2 receptor binding in all areas of the striatum, reaching statistical significance in the ventral caudate and putamen (p = 0.01 and p = 0.044, respectively). This reduction was more marked in males than females, particularly in the putamen. A genetic predisposition to lower D2 receptor expression may increase susceptibility to neuroleptic medication or clinical symptoms that are associated with diseases involving dopaminergic pathology.
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Affiliation(s)
- J Thompson
- MRC Neurochemical Pathology Unit, Newcastle General Hospital, Newcastle upon Tyne, UK
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Kennard A, Goodburn S, Golightly S, Piggott M. Serum screening for Down's syndrome. Midwives (1995) 1995; 108:207-10. [PMID: 7621124] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 01/26/2023]
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Piggott M, Wilkinson P, Bennett J. Implementation of an antenatal serum screening programme for Down's syndrome in two districts (Brighton and Eastbourne). The Brighton and Eastbourne Down's Syndrome Screening Group. J Med Screen 1994; 1:45-9. [PMID: 8790485 DOI: 10.1177/096914139400100109] [Citation(s) in RCA: 21] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/02/2023]
Abstract
OBJECTIVES To evaluate the introduction to two health districts of an antenatal serum screening programme for Down's syndrome using the triple test-measurement of alpha fetoprotein, unconjugated oestriol, and human chorionic gonadotrophin concentrations in second trimester serum samples. METHODS All women delivering at the main maternity units in both districts were eligible for the screening programme. A serum sample was taken between 15 and 22 weeks' gestation, confirmed by ultrasound scan. An estimated risk of 1 in 250 or greater was considered to be a screen positive result and further diagnostic tests were offered. As far as possible the outcome of all screened pregnancies was recorded, and babies with Down's syndrome born to women who declined serum screening were also identified. RESULTS 6990 singleton pregnancies were screened over a two year period, representing an estimated uptake of 67% (6990/ 10,443). After a screen positive result 80% of women (168/211; 95% confidence interval 74.2 to 85.1%) opted for amniocentesis. The false positive rate was 2.9% (203/6979; 95% confidence interval 2.5 to 3.3%). The detection rate in the screened population was 73% (8/11). The estimated cost of identifying one Down's syndrome affected pregnancy was about 31,000 pounds. CONCLUSIONS Successful introduction of the triple test to health districts where there is no established serum screening programme for neural tube defects is possible. The programme seems to be acceptable to most of those screened. Uptake of the programme is sufficient to make it more effective than a policy for Down's syndrome screening dependent on age only.
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Affiliation(s)
- M Piggott
- Brighton Healthcare NHS Trust, United Kingdom
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Piggott M. Making the numbers add up. Nurs Times 1988; 84:36-7. [PMID: 3340592] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 01/05/2023]
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Abstract
The right hind limb of twelve rabbits was vibrated for 15 min. Blood samples were taken before vibration from the right hind limb and after vibration from both the vibrated and the non-vibrated hind limbs. A control series was also run. Estimations were made of: haematocrit, whole-blood viscosity, erythrocyte xi potential and plasma fibrinogen concentration. There was no significant change in whole-blood viscosity in either limb after vibration. Erythrocyte xi potential was significantly increased (in both limbs) after vibration. Fibrinogen concentration did not change (in either limb) after vibration. Yield stress was significantly reduced (in both limbs) after vibration. High Shear Casson Law slope decreased in the vibrated limb after vibration.
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Ramcharan JE, Shoja HS, Piggott M, Taylor DE. The effects of vibration upon blood-viscosity and red-cell mobility: a study in vivo and in vitro. Biorheology 1982; 19:341-52. [PMID: 7093461 DOI: 10.3233/bir-1982-191-236] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/23/2023]
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Piggott M, Wagaine-Twabwe D, Ramcharan JE, Taylor D. Cerebral blood flow and blood viscosity in patients with polycythaemia secondary to hypoxic lung disease. Br Med J (Clin Res Ed) 1981; 283:1262. [PMID: 6797530 PMCID: PMC1507439 DOI: 10.1136/bmj.283.6301.1262-a] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.0] [Reference Citation Analysis] [What about the content of this article? (0)] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/21/2023]
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