1,721,349 research outputs found
What has been learnt from study of dopamine receptors in Parkinson's disease?
No full textSince the introduction of dopamine replacement therapy using L-3,4-dihydroxyphenyalanine (L-DOPA) to treat Parkinson's disease and the recognition of the problems associated with L-DOPA use, numerous studies have investigated dopamine receptor regulation and function in Parkinson's disease. These studies have provided insight into the pathological process of the disorder and the molecular consequences of chronic dopaminergic treatment, but they have been less successful in identifying new pharmacological targets or treatment regimes that are as effective as L-DOPA at alleviating the symptoms of Parkinson's disease. This review will present a summary of the reported changes in dopamine receptor regulation and function that occur in Parkinson's disease and will discuss their contribution to the current pharmacological management of Parkinson's disease.</p
Expression of cannabinoid CB1 receptor mRNA in basal ganglia of normal and parkinsonian human brain
No full textReverse transcription polymerase chain reaction (RT-PCR) was used to examine the expression of the cannabinoid CB(1) receptor mRNA in post-mortem brain tissue obtained from normal subjects and patients dying with Parkinson's disease. CB(1) receptor mRNA was detected in striatal (nucleus accumbens, caudate nucleus and putamen) and extrastriatal (globus pallidus, substantia nigra) brain regions. In parkinsonian tissue the level of CB(1) receptor mRNA was decreased in the caudate nucleus, anterior dorsal putamen and external segment of the globus pallidus, but remained unchanged in the other brain areas examined. These results show that CB(1) receptor mRNA expression was altered in Parkinson's disease (though the effects of drug treatment can not be ruled out) and indicate that cannabinoid CB(1) receptor mRNA expression was affected by alterations in dopaminergic systems.</p
Adenosine A2A receptors and Parkinson's disease
No full textThe drug treatment of Parkinson’s disease (PD) is accompanied by a loss of drug efficacy, the onset of motor complications, lack of effect on non-motor symptoms, and a failure to modify disease progression. As a consequence, novel approaches to therapy are sought, and adenosine A2A receptors (A2AARs) provide a viable target. A2AARs are highly localized to the basal ganglia and specifically to the indirect output pathway, which is highly important in the control of voluntary movement. A2AAR antagonists can modulate γ-aminobutyric acid (GABA) and glutamate release in basal ganglia and other key neurotransmitters that modulate motor activity. In both rodent and primate models of PD, A2AAR antagonists produce alterations in motor behavior, either alone or in combination with dopaminergic drugs, which suggest that they will be effective in the symptomatic treatment of PD. In clinical trials, the A2AAR antagonist istradefylline reduces “off” time in patients with PD receiving optimal dopaminergic therapy. However, these effects have proven difficult to demonstrate on a consistent basis, and further clinical trials are required to establish the clinical utility of this drug class. Based on preclinical studies, A2AAR antagonists may also be neuroprotective and have utility in the treatment of neuropsychiatric disorders. We are only now starting to explore the range of potential uses of A2AAR antagonists in central nervous system disorders, and their full utility is still to be uncovered
Going Beyond Counting First Authors in Author Co-citation Analysis
Full text linkThe present study examines one of the fundamental aspects of author co-citation analysis (ACA) - the way co-citation
counts are defined. Co-citation counting provides the data on which all subsequent statistical analyses and mappings
are based, and we compare ACA results based on two different types of co-citation counting - the traditional type that
only counts the first one among a cited work's authors on the one hand and a non-traditional type that takes into
account the first 5 authors of a cited work on the other hand. Results indicate that the picture produced through this non-traditional author co-citation counting contains more coherent author groups and is therefore considerably clearer. However, this picture represents fewer specialties in the research field being studied than that produced through the traditional first-author co-citation counting when the same number of top-ranked authors is selected and analyzed. Reasons for these effects are discussed
Secretogranin II mRNA expression is increased in Parkinson disease and in MPTP-treated marmosets exposed to chronic L-Dopa administration
No full text
An appraisal of the antiparkinsonian activity of piribedil in 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine-treated common marmosets
No full textVariations on the Author
Full text link“Variations on the Author” discusses two of Eduardo Coutinho’s recent films (Um Dia na Vida, from 2010, and Últimas Conversas, posthumously released in 2015) and their contribution to the general question of documentary authorship. The director’s filmography is characterized by a consistent yet self-effacing form of authorial self-inscription: Coutinho often features as an interviewer that rather than express opinions propels discourses; an interviewer that is good at listening. This mode of self-inscription characterizes him as an author who is not expressive but who is nonetheless markedly present on the screen. In Um Dia na Vida, however, Coutinho is completely absent form the image, while Últimas Conversas, on the contrary, includes a confessional prologue that moves the director from the margins to the center of his films. This article examines the ways in which these works stand out in the filmography of a director who offers new insights into the notion of cinematic authorship
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