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)

In unilaterally 6-hydroxydopamine (6-OHDA)-lesioned rats, a rodent model of Parkinson's disease (PD), the adenosine A(2A) receptor antagonist SCH 58261 significantly increased (+180%, p <.01) the number of rotations induced by a low dose of quinpirole (a dopamine D(2) receptor agonist), while it did not significantly modify the effects of a comparably low dose of SKF 38393 (a dopamine D(1) receptor agonist). The dose-dependent potentiating effects of SCH 58261 on quinpirole-induced turning were similar in caffeine-treated rats (1 g/l in drinking water over 14 days) and control animals (tap water). The selective potentiating effects of SCH 58261 on D(2)-dependent turning confirm the existence of a potent and specific A(2A)/D(2) receptor-receptor interaction. The persistence of the potentiating effects of SCH 58261 after chronic caffeine intake suggests that no tolerance should develop towards the antiparkinsonian effects of adenosine A(2A) receptor antagonists with chronic treatment.
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PMID:Effects of SCH 58261, an adenosine A(2A) receptor antagonist, on quinpirole-induced turning in 6-hydroxydopamine-lesioned rats. Lack of tolerance after chronic caffeine intake. 1073 27

The BRAIN TEST, a computerized alternating finger tapping test, was performed on 154 patients with parkinsonism to assess whether the test could be used as an objective tool to evaluate reliably the severity of Parkinson's disease (PD). Patients were instructed to tap two marked computer keyboard keys as fast and as accurately as possible for 60 seconds. The test generates the following variables: (1) kinesia score (KS)--number of keystrokes/min, (2) akinesia time (AT)--cumulative time that keys are depressed, (3) dysmetria score (DS)--a weighted score generated from incorrectly hit keys and corrected for speed, and (4) arrhythmia score (AS)--variance of the time interval between individual keystrokes. Among parkinsonian patients, we found a significant correlation between the four test parameters and PD rating scores of the Hoehn & Yahr, Schwab & England, and Unified PD Rating Scales (KS, AS, and AT p <0.001 and DS p <0.05). When compared with 73 parkinsonian patients 73 age- and sex-matched control subjects showed significantly higher KS and lower AT (p <0.001) as well as lower DS and AS (p = 0.05). The BRAIN TEST is a reliable and practical tool for evaluating the severity of parkinsonism and for distinguishing subjects with parkinsonism from normal control subjects. A version of the BRAIN TEST is available by FTP on the worldwide web (http://www.anaesthetist.com/software/brain.htm).
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PMID:The Bradykinesia Akinesia Incoordination Test (BRAIN TEST), an objective and user-friendly means to evaluate patients with parkinsonism. 1092 73

According to a report by Jens Jordan and colleagues, tap water has substantial pressor effects. They reported that 480 ml of Nashville tap water raised systolic blood pressure in seated, healthy, middle-aged people by 11 mmHg and in patients with orthostatic hypotension due to chronic autonomic failure by more than 30 mmHg. The pressor effects began a few minutes after the water had been drunk, peaked at about 20 minutes, and remained raised for a further 25 minutes before returning to baseline values by 80 minutes. However, these findings were questioned by Senard and colleagues, who gave 500 ml of Toulouse tap water to patients with Parkinson's disease and autonomic failure but did not observe a rise in blood pressure. The author comments that both reports did not provide the composition of the tap water, which raises the possibility that the pressor effects might have been due to chemicals or electrolytes in the water. Thus, the precise mechanisms causing the pressor response to tap water still remain to be determined. Even so, there are various implications arising from the observations especially in the elderly and in patients with autonomic failure.
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PMID:A 21st century water cure. 1113 May 50

It has been claimed that patients with Parkinson's disease (PD) are deficient in estimating and reproducing time intervals in the range of seconds. This deficit is more severe when subjects are requested to count internally during the demanded intervals, and when the rate of internal counting is fast. The observed deficit might therefore reflect slow internal counting, i. e. motor slowness, rather than a specific deficit of temporal processing. However, PD patients also have a higher temporal discrimination threshold for sensory stimuli, a finding purportedly indicating a slow 'internal clock'. In this study we examined PD patients' processing of short durations (approx. 1s,'psychological present') and long durations (up to 48 s,'extended present'). In the first experiment the ability to discriminate between temporally overlapping presentations of two visual stimuli (darkened rectangles on the computer screen) in the range of one second was tested. In the second experiment PD patients' ability to estimate time intervals between 12 and 48 s was investigated. During these intervals, subjects were required to tap and read a random number on the computer screen at a rate of 1 Hz. We found that the patients were impaired at discriminating between short intervals. This deficit was independent of task difficulty and appeared to be based on an impairment of divided attention. Despite this deficit, the PD patients estimated time intervals up to 48 s as accurately as the controls. We suggest that time estimation, i. e. the feeling for the flow of time, is normal in PD patients despite impaired discrimination of brief intervals in the range of seconds.
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PMID:Time estimation in Parkinson's disease: normal long duration estimation despite impaired short duration discrimination. 1126 17

There is continued interest in the assessment and potential use of antioxidants as neuroprotective agents in diseases associated with increased oxidative stress, such as Parkinson's disease. The neuroprotective effect of a natural antioxidant drink, EM-X (a ferment derivative of unpolished rice, papaya and seaweeds with effective microorganisms), was investigated using the 6-hydroxydopamine (6-OHDA)-lesion rat model of Parkinson's disease. The nigrostriatal dopaminergic neurons were unilaterally lesioned with 6-OHDA (8 microg) in rats that were treated with a 10-times diluted EM-X drink (dilEM-X), standard EM-X drink (stdEM-X) or tap water for 4 days. Seven days post lesion, the integrity (no. of tyrosine hydroxylase positive cells (TH+ cells) in the substantia nigra pars compacta (SNpc)) and functionality (dopamine and its metabolites DOPAC and HVA content in the striata) of nigrostriatal dopaminergic neurons were assessed. In the vehicle-treated rats, infusion of 8 microg of 6-OHDA significantly reduced the number of TH+ cells in the SNpc as well as the levels of dopamine, DOPAC and HVA in the striata on the lesion side. The loss of TH+ cells, dopamine and HVA, but not the DOPAC levels, was significantly attenuated by stdEM-X pretreatment, but not by the dilEM-X pretreatment. There were no significant changes in the TH+ cells, or in the monoamine levels with the EM-X pretreatment per se, except for a small but significant fall in the levels of dopamine with the stdEM-X. The evidence presented supports the potential neuroprotective effects of stdEM-X drink, although its effect on dopamine levels needs further investigation.
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PMID:The antioxidant drink effective microorganism-X (EM-X) pre-treatment attenuates the loss of nigrostriatal dopaminergic neurons in 6-hydroxydopamine-lesion rat model of Parkinson's disease. 1514 43

Recently, it has been shown that rhythmic inter-limb coordination is disturbed in patients with Parkinson's disease (PD). The present study aims to investigate whether this coordination deficit is primarily the result of an impaired coupling, related to hypoactivation of the supplementary motor area (SMA), or primarily the indirect result of an asymmetrical distribution of PD symptoms over the left and right limbs (a peripheral process). Thirty PD patients and 30 matched control participants tapped with the index fingers anti-phase and left and right leading gallop patterns in four visual feedback conditions. Symmetrically affected participants performed significantly worse than asymmetrically affected and control participants in the gallop patterns. This result suggested that the central deficit has a stronger effect on inter-limb coupling in PD than the neuromuscular and biomechanical asymmetry between the limbs. Detailed analysis of inter-tap intervals (variability and correlation) suggested that this deficit leads to a compensatory asymmetrical inter-limb coupling in the primarily right-affected patient group, and under specific circumstances also in the primarily left-affected patient group. The difference in coordination strategy between left- and right-affected patients suggested that pre-morbid hand preference is an important structural constraint on the coupling strategies available to the participants.
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PMID:Inter-limb coupling in bimanual rhythmic coordination in Parkinson's disease. 1554 32

Studies of basal ganglia dysfunction in humans have generally involved patients with degenerative disorders, notably Parkinson's disease. In many instances, the performance of these patients is compared to that of patients with focal lesions of other brain structures such as the cerebellum. In the present report, we studied the performance of patients with focal basal ganglia lesions on three fundamental motor tasks. The patients all had suffered unilateral damage in the striatum and were tested in the chronic state. The first task required the participants to tap with their index finger as fast as possible; this test provided a simple assessment of motor competence. Compared to controls, the maximum tapping rate was lower for the patients when tapping with their contralesional limb, although the deficit was not severe. The second and third tasks were designed to assess timing and force control, two functions that have been associated with basal ganglia function. The patients performed similar to controls on both tasks and showed no evidence of impairment when using their contralesional limb compared to their ipsilesional limb. The results indicate that unilateral basal ganglia lesions tend to produce minor motor problems in force control, and fail to support the hypothesized role of the basal ganglia in timing.
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PMID:Effects of focal basal ganglia lesions on timing and force control. 1587 27

Hyperechogenicity of the substantia nigra (SN) detected by transcranial sonography is a typical finding in more than 90% of patients with Parkinson's disease (PD) but may also be visible in about 9% of healthy adults. In this study, we found a correlation between SN hyperechogenicity and subtle motor dysfunction in otherwise healthy young tap dancers. In accordance with former findings, results of the present study confirm the hypothesis that SN hyperechogenicity is a marker for a possible functional impairment of the nigrostriatal system, that may become evident under challenging conditions.
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PMID:Substantia nigra hyperechogenicity correlates with subtle motor dysfunction in tap dancers. 1705 30

The aim of this work was to evaluate the measurement properties and hierarchical item structure of the Epworth Sleepiness Scale (ESS) in patients with Parkinson's disease (PD). Data were taken from a cross-sectional study regarding fatigue and sleep-related aspects of PD. One hundred and eighteen consecutive patients with neurologist-diagnosed PD without significant co-morbidities (54% men; mean age, 64 years; mean PD duration, 8.4 years) from four Swedish neurological outpatient clinics participated. The ESS displayed good data quality with few missing items (0-2.5%): good reliability (Cronbach's alpha, 0.84), marginal floor and no ceiling effects (1.7% and 0% respectively), and differentiated between those reporting problems staying awake during the past month and those who did not. Item-total correlations, factor and Rasch analyses indicated that items tap a single underlying construct. Rasch analysis supported basic rating scale assumptions and demonstrated an item hierarchy similar to that previously found in patients with other sleep disorders. Gaps in the levels of sleep propensity covered by ESS items and their response options were identified at the higher and lower ends of the underlying sleepiness continuum. This study provides an evidence base for using the ESS in PD by demonstrating good psychometric properties and a stable hierarchical item structure. However, addition of new items and use of Rasch scoring has potential to further enhance the clinical usefulness of the ESS.
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PMID:Measurement properties and hierarchical item structure of the Epworth Sleepiness Scale in Parkinson's disease. 1730 69

Homozygous weaver mutant mice (wv/wv) exhibit symptoms that parallel Parkinson's disease, including motor deficits and the destruction of dopaminergic neurons as well as degeneration in the cerebellum and hippocampus. To develop a more complete behavioral profile of these organisms, groups of wv/wv, wv/+ mice and C57BL/6 mice were observed on a within-subjects basis under a fixed-interval schedule of reinforcement, a differential-reinforcement-of-low-rate-of-responding schedule, and a discrimination task in which a saccharin solution and tap water were concurrently available from two food cups. Under both reinforcement schedules, the wv/wv mice responded as frequently as the comparison subjects, but they responded in a manner that was inappropriate to the contingencies. Rather than respond with increasing frequency as the upcoming reinforcer became temporally proximate, wv/wv mice responded with decreasing probability as a function of the time since the previous reinforcer. Under the discrimination task, the wv/wv mice, unlike the controls, obtained saccharin over tap water at the level of chance. The findings suggest that weaver mutant mice express learning deficits similar to those found in other dopamine-deficient organisms.
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PMID:Weaver mutant mice exhibit long-term learning deficits under several measures of instrumental behavior. 1782 5


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