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)

The aetiology and pathogenesis of Alzheimer's disease are currently poorly understood, but symptomatic disease is associated with amyloid plaques, neurofibrillary tangles, neuronal loss and numerous alterations of neurotransmitter systems in the CNS. Monoamine oxidase type B is known to be increased in Alzheimer diseased brains. The distribution and abundance of catalytic sites for monoamine oxidases A and B in post mortem human brains of 11 Alzheimer disease cases and five age-matched controls were investigated by quantitative enzyme radioautography. Using tritiated monoamine oxidase inhibitors (Ro41-1049 and lazabemide)--as high affinity substrates selective for monoamine oxidases A and B, respectively--it was found that monoamine oxidase B activity increased up to three-fold exclusively in temporal, parietal and frontal cortices of Alzheimer disease cases compared with controls. This increase was restricted to discrete patches (approximately 185 microns in diameter) which occupied approximately 12% of the cortical areas examined. In other brain regions (hippocampal formation >> caudate-putamen > cerebellum), patches of [3H]lazabemide-enriched binding were less abundant. [3H]Ro41-1049 binding (i.e. monoamine oxidase A) was unchanged in all tissues of diseased versus control brains. The monoamine oxidase B-enriched patches in all cortical regions correlated, in their distribution and frequency, with glial fibrillary acidic protein-immunoreactive clusters of astrocytes. Diffuse and mature beta-amyloid-immunoreactive senile plaques as well as patches of high density binding of [3H]PK-11195--a high-affinity ligand for peripheral-type (mitochondrial) benzodiazepine binding sites in microglia/macrophages--were found throughout Alzheimer diseased cortices. The up-regulation of monoamine oxidase B in plaque-associated astrocytes in Alzheimer's disease--in analogy to its proposed role in neurodegenerative disorders such as Parkinson's disease--might, indirectly, be a potential source of cytotoxic free radicals. Lazabemide, a selective reversible monoamine oxidase B inhibitor, is currently under clinical evaluation for the treatment of Parkinson's and Alzheimer's diseases. We conclude that enzyme radioautography with [3H]lazabemide is a reliable high resolution assay for plaque-associated astroglioses in Alzheimer's disease. Its clinical diagnostic utility for positron emission tomography or single photon emission computer tomography studies is being investigated.
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PMID:Increased monoamine oxidase B activity in plaque-associated astrocytes of Alzheimer brains revealed by quantitative enzyme radioautography. 781 97

The monoamine oxidase type B inhibitor deprenyl (selegiline) has been demonstrated to delay the emergence of disability in early untreated Parkinson's disease. Lazabemide (RO19-6327) is a short-acting, reversible, highly selective inhibitor of monoamine oxidase type B which, unlike deprenyl, is not metabolized to active compounds. We conducted a randomized, double-blinded clinical trial to assess the short-term tolerability of lazabemide in subjects who had early, untreated Parkinson's disease. Two hundred and one patients were enrolled at 14 centers and randomized to receive 100 mg/day, 200 mg/day, or 400 mg/day of lazabemide or matching placebo. Subjects were followed for 8 weeks including a randomized, double-blinded withdrawal of lazabemide for 2 or 4 weeks. The primary measure of tolerability was the proportion of treated subjects who were able to complete the study on their originally assigned treatment. Clinical features were assessed by the Unified Parkinson's Disease Rating Scale (UPDRS). Lazabemide treatment was as well tolerated as placebo and was not attended by serious adverse experiences. A significant improvement in the activities of daily living component of the rating scale was found after 4 weeks of lazabemide treatment, although other subscale scores did not change significantly. The overall safety and benefits of lazabemide observed in this short-term study justify further long-term investigations to determine if this monoamine oxidase type B inhibitor can slow the clinical progression of Parkinson's disease.
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PMID:A controlled trial of lazabemide (RO19-6327) in untreated Parkinson's disease. Parkinson Study Group. 848 5

Lazabemide (Ro 19-6327) is a relatively short-acting, reversible, and selective type B monoamine oxidase inhibitor that is not metabolized to amphetamines or other active compounds. We previously found lazabemide to be safe and well tolerated at dosages of up to 400 mg/day during a 6-week study of 201 patients with early untreated Parkinson's disease (PD). We now assess whether or not lazabemide influences the progression of disability in untreated PD. Patients (N = 321) were assigned by randomization to one of five treatment groups (placebo, 25 mg, 50 mg, 100 mg, or 200 mg/day) and followed systematically for up to 1 year. The risk of reaching the primary end point (the onset of disability sufficient to require levodopa therapy) was reduced by 51% for the patients who received lazabemide compared with placebo-treated subjects. This effect was consistent among all dosages. The frequency of adverse experiences did not differ among the treatment groups. At dosages ranging from 25 to 200 mg/day, lazabemide was well tolerated and delayed the need for levodopa in early, otherwise untreated PD. The magnitude and pattern of benefits were similar to those observed after 1 year of deprenyl (selegiline) treatment in the DATATOP clinical trial.
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PMID:Effect of lazabemide on the progression of disability in early Parkinson's disease. The Parkinson Study Group. 868 99

To evaluate whether lazabemide has proarrhythmic or hypotensive potency in Parkinson's disease (PD), we conducted an 8-week, double-blind, placcbo-controlled, parallel group study with use of 24-hour ambulatory electrocardiographic (ECG) monitoring. Fifty-one patients with PD who did not have clinically apparent heart disease were randomized in a double-blind fashion to receive either lazabemide (n = 25) or placebo (n = 26) treatments. Lazabemide therapy did not induce clinically significant arrhythmias. A paroxysmal atrioventricular (AV) block, which progressed from first-degree AV block, was found in one patient in the lazabemide group. This was determined not to be a new AV block. However, the causality of lazabemide in prolongation of the pause was not ruled out completely. In addition, the asymptomatic fall in systolic blood pressure seen 3 minutes after standing up was observed to be more pronounced in the lazabemide group than in the placebo group. The mean decrease of systolic blood pressure was 10 mmHg greater in the lazabemide group than in the placebo group. In conclusion, lazabemide did not induce any clinically significant arrhythmias in patients without clinically apparent heart disease. However, it may increase the asymptomatic, orthostatic drop in systolic blood pressure.
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PMID:Safety study of lazabemide (Ro19-6327), a new MAO-B inhibitor, on cardiac arrhythmias and blood pressure of patients with Parkinson's disease. 1062 94

l-Dopa, the metabolic precursor of dopamine, is the treatment of choice for the symptomatic relief of the advanced stages of Parkinson's disease. The oral bioavailability of l-dopa, however, is only about 10% to 30%, and less than 1% of the oral dose is estimated to reach the brain unchanged. l-Dopa's physicochemical properties are responsible for its poor bioavailability, short half-life and the wide range of inter- and intrapatient variations of plasma levels. An l-dopa-lazabemide prodrug is proposed to overcome the problems associated with l-dopa absorption. Lazabemide is a monoamine oxidase (MAO)-B inhibitor, a class of compounds that slows the depletion of dopamine stores in Parkinson's disease and elevates dopamine levels produced by exogenously administered l-dopa. l-Dopa was linked at the carboxylate with the primary aminyl functional group of lazabemide via an amide, a strategy which is anticipated to protect l-dopa against peripheral decarboxylation and possibly also enhance the membrane permeability of the prodrug. Selected physicochemical and biochemical properties of the prodrug were determined and included lipophilicity (logD), solubility, passive diffusion permeability, pKa, chemical and metabolic stability as well as cytotoxicity. Although oral and i.p. treatment of mice with the prodrug did not result in enhanced striatal dopamine levels, 3,4-dihydroxyphenylacetic acid (DOPAC) levels were significantly depressed compared to saline, l-dopa and carbidopa/l-dopa treatment. Based on the results, further preclinical evaluation of the l-dopa-lazabemide prodrug should be undertaken with the aim of discovering prodrugs that may be advanced to the clinical stages of development.
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PMID:The Design and Evaluation of an l-Dopa-Lazabemide Prodrug for the Treatment of Parkinson's Disease. 2918 17