Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UMLS:C0030567 (Parkinson's disease)
 63,064 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Corticobasal degeneration (CBD) and progressive supranuclear palsy (PSP) are characterized by their unique clinical features and neuronal pathology. Although astrocytic plaques and tufts of abnormal fibers have been suggested to be specific histopathologic markers, recent studies have revealed significant clinicopathologic overlap between CBD and PSP. Based on the distinctive camera lucida profile of astrocytic inclusions on Gallyas-Braak silver staining, we found that astrocytic plaques and tufts of abnormal fibers did not coexist in the same patient among 30 cases of clinically diagnosed CBD, PSP and atypical Parkinson's disease. Using Tau immunohistochemistry it was difficult to verify the absence of tufts of abnormal fibers. A morphometric analysis revealed that the two groups classified by the presence or absence of astrocytic plaques and tufts of abnormal fibers exhibited significant differences in the density of ballooned neurons and neurofibrillary tangles and degeneration of the subcortical nuclei. Assessment using the NINDS neuropathologic criteria revealed that the cases with astrocytic plaques and tufts of abnormal fibers closely correspond to CBD and typical PSP, respectively. In addition, the cases lacking either of these two astrocytic inclusions had atypical PSP according to the NINDS criteria, and were associated with novel tau-positive astrocytes (spiny astrocytes). We thus conclude that astrocytic plaques and tufts of abnormal fibers are highly characteristic structures for CBD and typical PSP, respectively. We emphasize the importance of strict differentiation between different astrocytic inclusions not only for diagnosis, but also for further studies for elucidation of their role in the disease mechanisms of CBD and PSP.
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PMID:Astrocytic plaques and tufts of abnormal fibers do not coexist in corticobasal degeneration and progressive supranuclear palsy. 979 5

A reliable and economical silver staining method is recommended for demonstration of Lewy bodies (LB) and Lewy neurites (LN) in Parkinson's disease (PD) and of argyrophilic oligodendrocytes in multiple system atrophy (MSA). The technique can be applied to routinely formalin-fixed autopsy material and does not require particular skills. It permits processing of frozen sections and sections from polyethylene glycol or paraffin embedded material. It takes advantage of the physical development of nucleation sites and thereby permits tight control of the entire staining procedure.
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PMID:Silver staining method for demonstrating Lewy bodies in Parkinson's disease and argyrophilic oligodendrocytes in multiple system atrophy. 1006

Sleep disruption and other circadian rhythm disturbances are frequently seen in dementia patients. In this study, we examined the suprachiasmatic nucleus (SCN), the putative site of the hypothalamic circadian pacemaker, to determine the nature and degree of pathologic changes caused by severe dementia. Neuropathologic examination indicated that among 30 patients with a clinical history of severe dementia, 22 had Braak and Braak stage V-VI Alzheimer disease, 3 had combined Alzheimer and Parkinson disease, 3 had Pick disease and 2 had severe hippocampal sclerosis. Comparisons were made with a control group composed of 13 age-matched patients with no clinical or pathological evidence of dementia or other CNS disorders. To determine the pathologic involvement within the SCN, human hypothalami were stained with: Nissl, Bielchowsky silver, thioflavin S and specific antibodies directed against vasopressin (VP), neurotensin (NT), neuropeptide Y (NPY), vasoactive intestinal peptide (VIP), beta-amyloid (B/A4) and glial fibrillary acidic protein (GFAP). Pathologic damage was primarily limited to neuronal loss and neurofibrillary tangle formation. Only rare diffuse plaques were noted. The pathologic changes within the SCN were less severe than in the other brain regions. Morphometric analysis was accomplished using a stereological approach to sample the average total number of positively stained neurons and astrocytes in 10 different 0.1mm2 microscopic fields in the dorsal subdivision of the SCN. Patients with Alzheimer disease exhibited a significant decrease in vasopressin (9.75 vs 16.7, p < 0.001) and neurotensin (6.82 vs 9.63, p < 0.002) neurons, as well as a corresponding increase in the GFAP-stained astrocyte/Nissl-stained neuron ratio (0.54 vs 0.10, p < 0.009). These studies provide evidence that both vasopressin and neurotensin neurons are lost in Alzheimer disease, and that the astrocyte/neuron ratio is a reliable indicator of disease-related pathology within the SCN. Taken collectively, our data support the hypothesis that damage to the SCN may be an underlying anatomical substrate for the clinically observed changes in circadian rhythmicity that have been observed in Alzheimer patients.
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PMID:Pathologic evaluation of the human suprachiasmatic nucleus in severe dementia. 1006 11

Immunostaining with anti-alpha-synuclein is used to detect Lewy bodies and Lewy neurites in cases of Parkinson's disease and related disorders. To prove that the result of a modern silver method is equivalent to that achieved with immunoreactions for alpha-synuclein, individual sections were successively processed using both methods. The silver-stained sections showed all of the immunoreactive Lewy bodies, and thin Lewy neurites were detected equally well by both techniques. The present study, therefore, points to the capabilities of a modern silver-staining method which is less time consuming and less expensive than immunocytochemical techniques.
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PMID:Alpha-synuclein immunoreactive Lewy bodies and Lewy neurites in Parkinson's disease are detectable by an advanced silver-staining technique. 1054 68

Alzheimer's disease is the most common cause of dementia It is associated with genetic risk factors and at least three autosomal dominant mutations. Community pathologists are frequently asked by families to evaluate autopsy material for Alzheimer's disease. Neuropathologic diagnosis is based on technically difficult silver impregnation stains that may not be readily available to community-based pathologists. Because immunohistochemical techniques are more widely accessible, we evaluated the practical utility of using a single immunohistochemical stain for diagnosing Alzheimer's disease. The ubiquitin antigen was selected because of its presence in morphologically distinct deposits characteristic of several neurodegenerative diseases. Paraffin blocks were obtained from the Bryan Alzheimer's Disease Research Center Brain Bank, a repository of approximately 900 brains. Tissues from 16 individuals who exhibited the entire range of Alzheimer's-type neuropathology were selected. Ubiquitin immunostains, evaluated blindly and independently by four pathologists ranging from first-year resident trainee to experienced neuropathologist, reliably stained both neuritic plaques and neurofibrillary tangles essential for diagnosing and staging Alzheimer's disease. Nondemented controls with early Alzheimer's-type changes were easily distinguished from cases of definitive Alzheimer's disease. The stains also highlighted characteristic inclusions of Parkinson's disease or Lewy body dementia Ubiquitin immunohistochemistry is a reliable, reproducible, and readily available diagnostic aid for distinguishing Alzheimer's disease from other causes of dementia.
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PMID:Ubiquitin immunochemistry as a diagnostic aid for community pathologists evaluating patients who have dementia. 1078 9

Dopamine may contribute to the loss of dopamine neurons in Parkinson's disease by generating reactive oxygen species and quinones. A previous report from this laboratory showed that intrastriatal injection of dopamine resulted in the selective reduction of tyrosine hydroxylase immunoreactivity, accompanied by an increase in indices of dopamine oxidation. However, conclusive proof that decreased tyrosine hydroxylase immunoreactivity represented a loss of dopamine terminals was lacking. In this paper, we demonstrate that injection of dopamine results in a selective loss of dopamine terminals by (i) showing that immunoreactivity for another selective marker for dopamine terminals, the dopamine transporter, is also reduced; and (ii) that amino-cupric-silver stain reveals terminal degeneration within the area of selective loss of dopamine terminals. To determine the dopamine concentration that is selectively toxic to dopamine terminals, we examined changes in extracellular dopamine and 3,4-dihydroxyphenylacetic acid in the area of selective terminal loss following intrastriatal dopamine. Dopamine and 3,4-dihydroxyphenylacetic acid in this region reached peak levels 1-2h after the injection, and then returned towards baseline. The peak level of dopamine in the area of selective dopamine terminal damage was 10(2)-10(3)-fold lower than the injected concentration. Changes in striatal tissue levels of cysteinyl-catechols and glutathione were examined at 2, 4, 8, and 24h after intrastriatal dopamine. Levels of protein cysteinyl-dopamine and cysteinyl-3,4-dihydroxyphenylacetic acid were increased at all time-points following the dopamine injection. High levels of free cysteinyl-catechols and glutathione-dopamine were detected within 2h after the dopamine injection. Glutathione levels were decreased significantly at 4 and 8h after the injection of dopamine, and returned to control levels by 24h. These data indicate that dopamine terminals actively degenerate following a single intrastriatal injection of dopamine, and furthermore that oxidative stress plays a key role in this process. As oxidative stress is thought to play an active role in the pathobiology of Parkinson's disease, these data may be relevant to our understanding of the disorder.
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PMID:Role of oxidative changes in the degeneration of dopamine terminals after injection of neurotoxic levels of dopamine. 1106 37

Glutamatergic neurotransmission in the substantia nigra pars compacta and pars reticulata is mediated through N-methyl-D-aspartate and alpha-amino-3-hydroxy-5-methyl-4-isoxaline propionic acid/kainate (AMPA) type receptors as well as other glutamate receptors and is critical for basal ganglia functioning. A major glutamatergic input to the substantia nigra originates in the subthalamic nucleus, and the long-lasting stimulation of the dopaminergic cells of the substantia nigra pars compacta by the subthalamic neurons has been implicated in the pathophysiology of Parkinson's disease. The objectives of the present study were to determine the subcellular and subsynaptic localization of subunits of the N-methyl-D-aspartate and AMPA receptors in the substantia nigra, and also to determine whether co-localization of N-methyl-D-aspartate and AMPA receptor subunits occur at individual synapses. To achieve this, pre-embedding and post-embedding immunocytochemistry was applied to sections of substantia nigra using antibodies that recognize the NR1 and NR2A/B subunits of the N-methyl-D-aspartate receptor, and GluR2/3 subunits of the AMPA receptor. In both regions of the substantia nigra, immunolabelling for each of the subunits was observed in numerous perikarya and proximal dendrites. At the subcellular level, silver-intensified immunogold particles localizing N-methyl-D-aspartate and AMPA receptor subunits were most commonly present within dendrites where they were associated with a variety of intracellular organelles and with the internal surface of the plasma membrane. Post-embedding immunogold labelling revealed immunoparticles labelling for NR1, NR2A/B and GluR2/3 to be enriched at asymmetric synaptic specializations, although a large proportion of asymmetric synapses were immunonegative. Double immunolabelling revealed, in addition to single-labelled synapses, the co-localization of subunits of the N-methyl-D-aspartate receptor and subunits of the AMPA receptor at individual asymmetric synapses. Similarly, double immunolabelling also revealed the co-localization of the NRl and NR2A/B subunits of the N-methyl-D-aspartate receptor at individual asymmetric synapses. Labelling for NR1 and GluR2/3 was, on average, relatively evenly distributed across the width of the synapse with a gradual reduction towards the periphery when analysed in single sections. In summary, the present results demonstrate that AMPA and N-methyl-D-aspartate receptors are selectively localized at a subpopulation of asymmetric synapses in the substantia nigra pars compacta and reticulata and that the two receptor types, at least partially co-localize at individual synapses. It is concluded that glutamatergic transmission in the substantia nigra pars compacta and pars reticulata occurs primarily at asymmetric synapses and, at least in part, is mediated by both N-methyl-D-aspartate and AMPA receptors.
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PMID:Synaptic localization of ionotropic glutamate receptors in the rat substantia nigra. 1111 53

1. Rasagiline [N-propargyl-1R(+)-aminoindan], was examined for its monoamine oxidase (MAO) A and B inhibitor activities in rats together with its S(-)-enantiomer (TVP 1022) and the racemic compound (AGN-1135) and compared to selegiline (1-deprenyl). The tissues that were studied for MAO inhibition were the brain, liver and small intestine. 2. While rasagiline and AGN1135 are highly potent selective irreversible inhibitors of MAO in vitro and in vivo, the S(-) enantiomer is relatively inactive in the tissues examined. 3. The in vitro IC(50) values for inhibition of rat brain MAO activity by rasagiline are 4.43+/-0.92 nM (type B), and 412+/-123 nM (type A). The ED(50) values for ex vivo inhibition of MAO in the brain and liver by a single dose of rasagiline are 0.1+/-0.01, 0.042+/-0.0045 mg kg(-1) respectively for MAO-B, and 6.48+/-0.81, 2.38+/-0.35 mg kg(-1) respectively for MAO-A. 4. Selective MAO-B inhibition in the liver and brain was maintained on chronic (21 days) oral dosage with ED(50) values of 0.014+/-0.002 and 0.013+/-0.001 mg kg(-1) respectively. 5. The degree of selectivity of rasagiline for inhibition of MAO-B as opposed to MAO-A was similar to that of selegiline. Rasagiline was three to 15 times more potent than selegiline for inhibition of MAO-B in rat brain and liver in vivo on acute and chronic administration, but had similar potency in vitro. 6. These data together with lack of tyramine sympathomimetic potentiation by rasagiline, at selective MAO-B inhibitory dosage, indicate that this inhibitor like selegiline may be a useful agent in the treatment of Parkinson's disease in either symptomatic or L-DOPA adjunct therapy, but lack of amphetamine-like metabolites could present a therapeutic advantage for rasagiline.
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PMID:Rasagiline [N-propargyl-1R(+)-aminoindan], a selective and potent inhibitor of mitochondrial monoamine oxidase B. 1115

Advanced silver stains and immunohistochemical reactions against alpha-synuclein were used to detect Parkinson's disease-related cytoskeletal abnormalities in select lower brain stem nuclei. Various types of inclusion bodies including inconspicuous and heretofore unnoted granular particles and thread-like Lewy neurites were visualized. Of the nuclei investigated (gigantocellular reticular nucleus, bulbar raphe nuclei, coeruleus-subcoeruleus area), only lipofuscin- or neuromelanin-laden neuronal types showed a propensity to develop the pathological changes. Neuronal types devoid of pigment deposits remained free of the cytoskeletal abnormalities. Fine, dust-like particles and small globular Lewy bodies were encountered solely within the limits of intraneuronal lipofuscin or neuromelanin deposits.
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PMID:alpha-synuclein immunopositive Parkinson's disease-related inclusion bodies in lower brain stem nuclei. 1130 17

Parkinson's disease (PD) is characterized by the progressive loss of substantia nigra dopaminergic neurons and the presence of cytoplasmic inclusions named Lewy bodies. Two missense mutations of the alpha-synuclein (alpha-syn; A30P and A53T) have been described in several families with an autosomal dominant form of PD. alpha-Syn also constitutes one of the main components of Lewy bodies in sporadic cases of PD. To develop an animal model of PD, lentiviral vectors expressing different human or rat forms of alpha-syn were injected into the substantia nigra of rats. In contrast to transgenic mice models, a selective loss of nigral dopaminergic neurons associated with a dopaminergic denervation of the striatum was observed in animals expressing either wild-type or mutant forms of human alpha-syn. This neuronal degeneration correlates with the appearance of abundant alpha-syn-positive inclusions and extensive neuritic pathology detected with both alpha-syn and silver staining. Lentiviral-mediated expression of wild-type or mutated forms of human alpha-syn recapitulates the essential neuropathological features of PD. Rat alpha-syn similarly leads to protein aggregation but without cell loss, suggesting that inclusions are not the primary cause of cell degeneration in PD. Viral-mediated genetic models may contribute to elucidate the mechanism of alpha-syn-induced cell death and allow the screening of candidate therapeutic molecules.
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PMID:alpha -Synucleinopathy and selective dopaminergic neuron loss in a rat lentiviral-based model of Parkinson's disease. 1212 8


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