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

The pathogenesis of Parkinson's disease (PD) has been linked to oxidative-mediated events including increased monoamine oxidase (MAO) and free-radical generation. We are investigating the ability of the MAO inhibitor, selegiline (deprenyl), and of the free-radical scavenger, tocopherol, to delay the onset of disability requiring levodopa therapy (primary end point) in patients with early PD. Eight hundred patients with early, untreated PD were enrolled in the multi-center placebo-controlled, double-blind clinical trial 'Deprenyl and Tocopherol Antioxidative Therapy of Parkinsonism (DATATOP)'. Subjects were assigned by 2 x 2 factorial design to receive selegiline (10 mg/day), tocopherol (2,000 IU/day), a combination of both drugs, or placebo, and followed to determine if and when disability occurred requiring levodopa therapy. After 12 +/- 5 months of observation, independent monitoring prompted a preliminary analysis indicating that selegiline 10 mg/day significantly extended the time to the primary end point. Selegiline therapy, alone or in combination with tocopherol, resulted in a 57% reduction in the rate of developing disability requiring levodopa therapy (p < 10(-10)) and a 50% reduction in the rate of loss of full-time employment (p = 0.01). Deterioration of motor and mental features was significantly less in selegiline-treated subjects. Adverse effects were minor and infrequent. We conclude from these preliminary results that selegiline (10 mg/day) delays the onset of disability associated with early, otherwise untreated PD. It remains unclear whether these benefits derive from mechanisms that are symptomatic (dopaminergic), protective (anti-neurotoxic), or both. The DATATOP study is ongoing to examine the long-term effects of selegiline and the independent and interactive effects of tocopherol.
 ...
PMID:An interim report of the effect of selegiline (L-deprenyl) on the progression of disability in early Parkinson's disease. The Parkinson Study Group. 142 20

Increasing knowledge of the role of brain iron in health and disease has prompted consideration of therapeutic strategies aimed at attenuating the effects of iron and its untoward oxidative consequences. The success of this approach is critically dependent on a better understanding of the pathogenesis of Parkinson's disease. The controlled trial "Deprenyl and Tocopherol Antioxidative Therapy of Parkinsonism" (DATATOP) represents a clinical strategy to detect neuroprotective effects of antioxidative interventions. Validation of reliable biological markers of nigral degeneration is central to development of therapies that exert genuine neuroprotective effects in slowing the progression and preventing the onset of Parkinson's disease.
 ...
PMID:Neuroprotective clinical strategies for Parkinson's disease. 151 Mar 74

We conducted prospective cognitive assessments over 14 +/- 6 (mean +/- SD) months of observation as part of the multicenter trial Deprenyl and Tocopherol Antioxidative Therapy of Parkinsonism (DATATOP), which involved 800 patients with early untreated Parkinson's disease. We administered tests that measured memory, visuospatial, and frontal lobe functions. Subjects were randomly assigned to receive placebo, deprenyl (10 mg/d), tocopherol (2,000 IU/d), or both deprenyl and tocopherol. We analyzed treatment effects using annualized rates of cognitive change. We performed exploratory analyses to identify potential clinical and demographic correlates of cognitive performance. There was no significant effect of either deprenyl or tocopherol on cognitive test performance. In early untreated Parkinson's disease, cognitive performance appears to be stable and unrelated to either motor deterioration or treatment with deprenyl or tocopherol.
 ...
PMID:The effect of deprenyl and tocopherol on cognitive performance in early untreated Parkinson's disease. Parkinson Study Group. 793 11

Levodopa, at concentrations of 0.25 x 10(-4) M or larger, is toxic for the human neuroblastoma cell NB69. Toxicity is associated with high levels of quinones, increased activity of complex II-III, and lack of changes of complex I of the mitochondrial respiratory chain. Deprenyl, which does not alter the production of quinones, has a partial protective effect. Tocopherol, 23 or 115 x 10(-6) M, lacks significant preventive effect on levodopa toxicity, but ascorbic acid, 10(-3) M, prevents levodopa toxicity and quinone formation. Deprenyl, 10(-4) M, provides additional protection in cultures treated with levodopa and ascorbic acid. Our results indicate that ascorbic acid and deprenyl prevent levodopa neurotoxicity by unrelated mechanisms. Both compounds should be considered as complementary drugs to test for slowing the progression of Parkinson's disease.
 ...
PMID:Ascorbic acid protects against levodopa-induced neurotoxicity on a catecholamine-rich human neuroblastoma cell line. 834 Dec 91

The Deprenyl and Tocopherol Antioxidant Therapy of Parkinsonism (DATATOP) trial was designed to test outcomes from treatment with 10 mg of deprenyl and/or 2,000 mg of tocopherol/day in 800 untreated patients with Parkinson's disease. The need of subjects for symptomatic treatment with levodopa and the conversion of all subjects to open-label deprenyl made it possible to study the long-term effect of early deprenyl and tocopherol treatment on the later development of levodopa-associated side effects. The rate of developing these side effects did not differ among the original treatment groups (early versus late deprenyl and tocopherol versus nontocopherol). About 50% of subjects developed "wearing off," 30% dyskinesias, and 25% "freezing" in each group. At the end of the study, the groups were similarly disabled on the Hoehn-Yahr, Schwab-England, and Unified Parkinson's Disease Rating scales and took similar amounts of levodopa. Young subjects were more likely to develop wearing off, women to develop dyskinesias, and older subjects with rapidly progressive disease to develop freezing. We conclude that prior treatment with deprenyl or tocopherol did not reduce the occurrence of subsequent levodopa-associated adverse effects in this population.
 ...
PMID:Impact of deprenyl and tocopherol treatment on Parkinson's disease in DATATOP patients requiring levodopa. Parkinson Study Group. 900 6

A large body of evidence indicates that the progression of Parkinson's disease (PD) may be fast in the preclinical stage as well as during the first years of the disease, with a subsequent slowing down of the disease process. As has been shown in the Deprenyl and Tocopherol Antioxidative Therapy of Parkinsonism (DATATOP) study, the Unified Parkinson's Disease Rating Scale (UPDRS) motor examination scores declined at a rate of 8 to 9% per year in untreated patients. A subgroup of levodopa-naive DATATOP patients ("survivors") showed a much slower rate of progression, in the order of 3% per year, suggesting a more benign disease course. A number of clinical factors that may govern the rate of motor decline, such as age at onset, disease duration, gender, and clinical phenotype (akinetic-rigid versus tremulous) have been proposed; however, none of them is proven. In contrast, dopaminergic substitution undoubtedly has had a major impact on the natural history of PD, resulting in a reduction of the mortality ratio from about 3.0 to 1.5. This benefit has been noted particularly in patients in whom levodopa therapy was started early. The positive impact of levodopa is largely derived from its symptomatic action; its influence on the disease process itself remains controversial.
 ...
PMID:The natural history of Parkinson's disease. 895 83

Progression of Parkinson's disease (PD) can be detected through changes in clinical ratings or disability assessments. A clinical trial, Deprenyl and Alpha-Tocopherol Antioxidative Therapy of Parkinsonism (DATATOP), used a novel study end point: increase in parkinsonian disability to the extent that investigators determined the need for treatment with levodopa. We analyzed DATATOP results to learn if this operationally defined end point could be reproduced from elements of the Unified PD Rating Scale (UPDRS) and other conventional clinical scales. Our analysis involved UPDRS, Schwab and England Activities of Daily Living (S-E ADL), and Hoehn and Yahr (H-Y) scores when DATATOP subjects reached the study end point. Various UPDRS components were examined, including subscores measuring severity of impaired ADL, bradykinesia, postural instability and gait difficulty, tremor, and rigidity. Data from subjects reaching the end point were compared with assessments of those DATATOP subjects who did not, matched for the same duration of enrollment. All measures showed subjects who reached the end point had significantly greater mean impairment than did controls, although the two groups had substantial overlap. Multivariate analysis by using conditional logistic regression suggested that the end point was determined more by functional (S-E ADL and the UPDRS ADL scores) than by clinical examination criteria. The method of classification and regression trees suggested a simple decision tree splitting, respectively, on S-E ADL, UPDRS ADL, H-Y score, and UPDRS ADL again, with an estimated overall misclassification probability of 18%. We conclude that the DATATOP end point cannot be fully reproduced from the traditional clinical measures, although it can give results that are consistent with these scales in a well-designed clinical trial.
 ...
PMID:The need for levodopa as an end point of Parkinson's disease progression in a clinical trial of selegiline and alpha-tocopherol. Parkinson Study Group. 908 76

Alpha-Tocopherol concentrations were determined in the CSF of patients with early untreated Parkinson's disease receiving 2,000 IU vitamin E orally per day. After treatment the concentrations increased significantly (p < 0.001) by 76+/-10 (SE)%. The net increases in CSF alpha-tocopherol concentrations after treatment showed a significant positive correlation with the number of days of vitamin E ingestion (p < 0.001). Thus, high-dose vitamin E treatment results in elevating CSF vitamin E levels and possibly brain vitamin E levels.
 ...
PMID:Alpha tocopherol in CSF of subjects taking high-dose vitamin E in the DATATOP study. Parkinson Study Group. 963 57

Our objective was to study the placebo response in Parkinson's disease (PD). We conducted a literature search in which placebo response was measured in all studies of PD from 1969 to April 1996. Strict criteria were defined to include or exclude published reports in our survey. The Parkinson Study Group database for Deprenyl & Tocopherol Antioxidative Therapy of Parkinsonism (DATATOP) was reviewed and placebo "responders" were compared to placebo "nonresponders" by age, race, religion, level of education, duration of PD, and gender. A significant difference between the efficacy of placebo and that of active drug was reported in 61% (22 of 36) of the articles meeting the required criteria; DATATOP analysis showed no statistically significant epidemiologic differences between 140 placebo responders and 58 placebo nonresponders except in PD effect on current job. Although there is clearly a placebo response in PD patients, our review suggests that the variation in placebo response does not correlate with demographic factors such as age, gender, religion, level of education, or duration of PD.
 ...
PMID:The placebo response in Parkinson's disease. Parkinson Study Group. 1044 49

6-Hydroxydopamine (6-OHDA) injected unilaterally into the striatum of rats induced contralateral circling, and increased the duration of stereotyped movements after subcutaneous (sc) injection of apomorphine both 3 and 13 weeks after surgery. Ten weeks after surgery, the spontaneous locomotor activity during 24 h of observation was decreased. Twelve weeks after 6-OHDA injection, the animals had difficulties in carrying out a spatial navigation task in the water maze when the submerged escape platform was moved to another position on each of four consecutive days. When learning to find a new platform position required switching behavior-strategies, latency and swim paths were increased because of significantly more perseverative crossings of the previous platform positions. Intraperitoneal (ip) injection of alpha-tocopherol for 8 days increased the ability of naive control animals to find the hidden platform positions in the water maze one week later. In intrastriatal sham-operated rats, 8 daily pre-injections of alpha-tocopherol significantly increased the duration and number of bursts of stereotyped movements during 30 min following a sc injection of apomorphine if measured 13 weeks after surgery. In 6-OHDA-lesioned rats, alpha-tocopherol prevented the increased response to apomorphine, reduced the apomorphine-induced circling at 3 and 13 weeks, and prevented the decrease in spontaneous locomotion at 10 weeks, as well as the perseverative platform crossings which are caused by an impairment in switching behavior-strategies in the navigation task 12 weeks after surgery. Alpha-Tocopherol has, however, no influence on 6-OHDA-induced changes in problem solving strategies. The used model reflects some of the pathological symptoms of Parkinson's disease, and it seems that alpha-tocopherol may be an effective drug in the early initial stages of the disease.
 ...
PMID:Behavioral alterations after unilateral 6-hydroxydopamine lesions of the striatum. Effect of alpha-tocopherol. 1199 61


1 2 Next >>