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BETA,BETA'-IMINODIPROPIONITRILE-INDUCED PERSISTENT DYSKINETIC SYNDROME IN MICE IS TRANSIENTLY MODIFIED BY MPTP
No full textChronic administration of iminodipropionitrile (IDPN) is known to produce a persistent dyskinetic syndrome. Recent neurochemical reports seem to point out the dopaminergic system as having an important role in mediating IDPN syndrome. In order to identify a possible role for the nigrostriatal dopaminergic pathway in determining at least some aspects of the IDPN-induced dyskinetic syndrome, we used the neurotoxin, 1-methyl, 4-phenyl,1,2,3,6-tetrahydropyridine (MPTP), as a tool for investigating which aspects of the IDPN-related syndrome could be due to enhanced dopaminergic activity in the neostriatum. In mice made permanently dyskinetic with IDPN, MPTP administration produced dramatic and biphasic effects on all behavioral patterns characteristic of the dyskinetic syndrome. Six weeks after the syndrome occurred, IDPN failed to produce any change in striatal DA levels with respect to controls. By contrast, IDPN seems to reduce striatal levels of extraneuronal metabolites of DA. These data suggest that the activity of the nigrostriatal dopaminergic pathway does not play a leading role in the maintenance of IDPN-related syndrome. The transient modification of all behavioral parameters immediately after MPTP administration could be explained by acute effects of MPTP on other dopaminergic areas which are not permanently lesioned by this neurotoxin, or by the acute effects of MPTP on the release of other neurotransmitters
Pharmacologic modulation of MPTP toxicity: MK 801 in prevention of dopaminergic cell death in monkeys and mice.
No full textSystemic administration of l-methyl-4phenyl-l,2,3,6-tetrahydropyridine (MPTP) induces,
in primates, a neurologic syndrome identical to Parkinson's disease. This corresponds
to an extensive and quite selective destruction of the dopaminergic neurons
in the substantia nigra pars compacta (SNc) and a dramatic decrease of the dopamine
content in the caudate and putamen nuclei. We have previously reported that, in mice,
an anatomic and biochemical lesion similar to that observed in monkeys can be obtained
by combining MPTP treatment with acetaldehyde (ACE).l-jH ere, we verified
similarities between these two models by studying whether excitatory amino acids are
involved in the mechanism of MPTP toxicity. A recent report indicates that MK 801,
a noncompetitive antagonist of the N-methyl-D-aspartate (NMDA) receptor, is able
to prevent the neuronal damage induced in the rat (a species insensitive to MRP) by
intranigd injection of MPP+, the toxic MPTP metab~liteI.n~ both mice and monkeys,
we systemically administered MK 801 together with MPTP and evaluated the
behavioral, biochemical, and histologic effects 7 days after treatment
Opioid control of pituitary function in parkinsonian patients before and after dopaminergic therapy
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Defective 5-HT1-receptor-mediated neurotransmission in the control of GH secretion in Parkinson’s disease.
No full textGoing Beyond Counting First Authors in Author Co-citation Analysis
Get PDFThe 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
Muscarinic cholinergic mediation of the GH response to gamma-hydroxybutyric acid: neuroendocrine evidence in normal and parkinsonian subjects
No full textTreatment of the motor and non-motor symptoms in Parkinson's disease according to cluster symptoms presentation.
No full textThe term Parkinson's disease has been changed in 'Parkinson's diseases' to describe different clinical entities observed in several studies investigating the existence of PD subtypes. PD patients could be grouped based on clinical features. By considering only motor symptoms, we can classically distinguish two groups: " the tremorigen-form" and "akinetic- rigidity-form" where resting tremor and akinesia/bradikynesia and rigidity are the most motor predominant symptoms, respectively. Non-motor symptoms (NMSs) are practically always present during the course of the disease and some of them (constipation, depressive status, hyposmia and anxiety) could even exist before the onset of classical motor symptoms. Many other NMSs and in particular hallucinations, cognitive impairment, sleep disorders and difficulty in swallowing strongly affect the advanced stage of disease, and represent a real therapeutic challenge when these symptoms are simultaneously present with different severity. If not adequately treated, they can increase the risk of hospitalization and admissions in nursing home, and profoundly and negatively influence the quality of life and participation in social activity of these patients. PD subtypes according to the combination of motor and non-motor symptoms have been recently proposed. This classification derives from cluster analysis which permits to identify statistically distinct subtypes of Parkinsonian patients according to the relevance of both motor and non-motor symptoms. In this point of view, we propose a schematic therapeutic approach of motor and non-motor symptoms in Parkinson's disease according to cluster symptoms presentation (motor and non-motor symptoms) and using medications that act on multiple domains of PD symptoms
Variations on the Author
Get PDF“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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