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1.
Med Probl Perform Art ; 32(4): 195-200, 2017 12.
Artigo em Inglês | MEDLINE | ID: mdl-29231952

RESUMO

BACKGROUND: The prevalence of musculoskeletal symptoms is high among professional musicians (73-88%). AIMS: We investigated the prevalence of musculoskeletal symptoms in Finnish symphony orchestra musicians. We compared individual instruments as well as the perceived demands of orchestral programs and difficulties in recovering after performances. METHODS: In this cross-sectional questionnaire 920 of 2,785 members of the Finnish Musicians' Union (33%) completed the questionnaire, including 361 full-time members of symphony orchestras. Questions about pain symptoms and frequency were based on the national survey done in 2011. RESULTS: Among the 361 full-time orchestra musicians, those playing all instruments experienced frequent pain, both in the last 30 days and exceeding 30 days in the last 12 months, in their neck or upper extremities. Female musicians experienced significantly more neck (69%), elbow (31%), and wrist (30%) pain than males (neck 52%, elbow 23%, wrist 19%). The profiles varied according to the different instruments and their playing positions. Musculoskeletal symptoms correlated with perceived demand of the orchestral program and difficulties in recovering after performances. Professional musicians experienced nearly twice as often neck pain in the last 30 days (female musicians 69%, male musicians 52%) than persons of the same age in the Finnish working population (female 41%, male 27%). CONCLUSION: Symphony orchestra musicians experience nearly twice as much musculoskeletal symptoms of the neck and upper extremities as others their age. To prevent musicians' playing-related problems, special emphasis should be focused on recovery after concerts, including the special demands of different composers and the frequency of rehearsals and performances.


Assuntos
Dor Musculoesquelética/epidemiologia , Música , Cervicalgia/epidemiologia , Doenças Profissionais/epidemiologia , Índice de Gravidade de Doença , Adulto , Estudos Transversais , Feminino , Finlândia , Humanos , Masculino , Pessoa de Meia-Idade , Medição da Dor , Inquéritos e Questionários
2.
Hum Mol Genet ; 26(8): 1432-1443, 2017 04 15.
Artigo em Inglês | MEDLINE | ID: mdl-28158749

RESUMO

De novo mutations in ATAD3A (ATPase family AAA-domain containing protein 3A) were recently found to cause a neurological syndrome with developmental delay, hypotonia, spasticity, optic atrophy, axonal neuropathy, and hypertrophic cardiomyopathy. Using whole-exome sequencing, we identified a dominantly inherited heterozygous variant c.1064G > A (p.G355D) in ATAD3A in a mother presenting with hereditary spastic paraplegia (HSP) and axonal neuropathy and her son with dyskinetic cerebral palsy, both with disease onset in childhood. HSP is a clinically and genetically heterogeneous disorder of the upper motor neurons. Symptoms beginning in early childhood may resemble spastic cerebral palsy. The function of ATAD3A, a mitochondrial inner membrane AAA ATPase, is yet undefined. AAA ATPases form hexameric rings, which are catalytically dependent on the co-operation of the subunits. The dominant-negative patient mutation affects the Walker A motif, which is responsible for ATP binding in the AAA module of ATAD3A, and we show that the recombinant mutant ATAD3A protein has a markedly reduced ATPase activity. We further show that overexpression of the mutant ATAD3A fragments the mitochondrial network and induces lysosome mass. Similarly, we observed altered dynamics of the mitochondrial network and increased lysosomes in patient fibroblasts and neurons derived through differentiation of patient-specific induced pluripotent stem cells. These alterations were verified in patient fibroblasts to associate with upregulated basal autophagy through mTOR inactivation, resembling starvation. Mutations in ATAD3A can thus be dominantly inherited and underlie variable neurological phenotypes, including HSP, with intrafamiliar variability. This finding extends the group of mitochondrial inner membrane AAA proteins associated with spasticity.


Assuntos
Adenosina Trifosfatases/genética , Paralisia Cerebral/genética , Proteínas de Membrana/genética , Proteínas Mitocondriais/genética , Paraplegia Espástica Hereditária/genética , ATPases Associadas a Diversas Atividades Celulares , Adenosina Trifosfatases/biossíntese , Adolescente , Adulto , Axônios/metabolismo , Axônios/patologia , Paralisia Cerebral/patologia , Pré-Escolar , Feminino , Regulação da Expressão Gênica , Humanos , Masculino , Proteínas de Membrana/biossíntese , Mitocôndrias/metabolismo , Mitocôndrias/patologia , Dinâmica Mitocondrial/genética , Membranas Mitocondriais/metabolismo , Membranas Mitocondriais/patologia , Proteínas Mitocondriais/biossíntese , Mutação , Paraplegia Espástica Hereditária/patologia , Serina-Treonina Quinases TOR/genética
3.
Neurobiol Aging ; 50: 168.e5-168.e8, 2017 02.
Artigo em Inglês | MEDLINE | ID: mdl-27838048

RESUMO

Mutations in SNCA are rare causes of familial Parkinson's disease (PD). We have previously described a novel p.Ala53Glu mutation in 2 Finnish families. To assess this mutation's frequency among Finnish PD patients, we screened 110 PD patients (mean age-of-onset 60 years) from Western Finland by Sanger sequencing of the third coding exon of SNCA. In addition, a sample of 47 PD subjects (mean age-of-onset 53 years) originating from Southern and Eastern Finland were studied using next-generation sequencing covering SNCA. Only one new individual with the p.Ala53Glu mutation was identified, confirming that this mutation is a rare cause of PD in the Finnish population. To search for a possible common origin of the p.Ala53Glu mutation, haplotype analysis was conducted in 2 families and in a patient from a third family (6 affected subjects) using both STR markers and a genome-wide SNP array. The results show that patients with the p.Ala53Glu mutation share a haplotype spanning a minimum of 5.7 Mb suggesting a common founder.


Assuntos
Efeito Fundador , Estudos de Associação Genética , Mutação , Doença de Parkinson/genética , alfa-Sinucleína/genética , Idoso , Idoso de 80 Anos ou mais , Estudos de Coortes , Éxons/genética , Feminino , Finlândia , Haplótipos/genética , Humanos , Masculino , Pessoa de Meia-Idade , População Branca/genética
4.
J Parkinsons Dis ; 5(2): 255-62, 2015.
Artigo em Inglês | MEDLINE | ID: mdl-25882059

RESUMO

While the etiology and pathogenesis of Parkinson's disease (PD) is still obscure, there is evidence for lifestyle factors influencing disease risk. Best established are the inverse associations with smoking and coffee consumption. In other contexts there is evidence that health effects of lifestyle factors may depend on gut microbiome composition. Considering the gastrointestinal involvement in PD, it was recently speculated, that the associations between smoking, coffee, and PD risk could be mediated by gut microbiota. Here we review such a possible mediatory role of gut microbiota taking into account recent findings on microbiome composition in PD and extending the scope also to urate.


Assuntos
Café/metabolismo , Microbioma Gastrointestinal/fisiologia , Doença de Parkinson/metabolismo , Doença de Parkinson/microbiologia , Fumar/metabolismo , Ácido Úrico/sangue , Animais , Humanos , Fatores de Risco
5.
Mov Disord ; 30(3): 350-8, 2015 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-25476529

RESUMO

In the course of Parkinson's disease (PD), the enteric nervous system (ENS) and parasympathetic nerves are amongst the structures earliest and most frequently affected by alpha-synuclein pathology. Accordingly, gastrointestinal dysfunction, in particular constipation, is an important non-motor symptom in PD and often precedes the onset of motor symptoms by years. Recent research has shown that intestinal microbiota interact with the autonomic and central nervous system via diverse pathways including the ENS and vagal nerve. The gut microbiome in PD has not been previously investigated. We compared the fecal microbiomes of 72 PD patients and 72 control subjects by pyrosequencing the V1-V3 regions of the bacterial 16S ribosomal RNA gene. Associations between clinical parameters and microbiota were analyzed using generalized linear models, taking into account potential confounders. On average, the abundance of Prevotellaceae in feces of PD patients was reduced by 77.6% as compared with controls. Relative abundance of Prevotellaceae of 6.5% or less had 86.1% sensitivity and 38.9% specificity for PD. A logistic regression classifier based on the abundance of four bacterial families and the severity of constipation identified PD patients with 66.7% sensitivity and 90.3% specificity. The relative abundance of Enterobacteriaceae was positively associated with the severity of postural instability and gait difficulty. These findings suggest that the intestinal microbiome is altered in PD and is related to motor phenotype. Further studies are warranted to elucidate the temporal and causal relationships between gut microbiota and PD and the suitability of the microbiome as a biomarker.


Assuntos
Microbioma Gastrointestinal , Doença de Parkinson/microbiologia , Idoso , Estudos de Casos e Controles , Fezes/química , Fezes/microbiologia , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Curva ROC , Índice de Gravidade de Doença
6.
Neurobiol Aging ; 35(9): 2180.e1-5, 2014 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-24746362

RESUMO

We describe the clinical, neuropathological, and genetic features of a Finnish patient with a novel α-synuclein (SNCA) mutation A53E. The patient was clinically diagnosed with atypical Parkinson's disease (PD) with age of onset at 36 years. In the neuropathological analysis performed at the age of 60 years, highly abundant SNCA pathology was observed throughout the brain and spinal cord showing features of multiple system atrophy and PD. Neuronal and glial (including oligodendroglial) SNCA inclusions and neurites were found to be particularly prominent in the putamen, caudatus, amygdala, temporal and insular cortices, gyrus cinguli, and hippocampus CA2-3 region. These areas as well as the substantia nigra and locus coeruleus showed neuronal loss and gliosis. We also found TDP-43 positive but mostly SNCA negative perinuclear inclusions in the dentate fascia of the hippocampus. The A53E mutation was found in 2 other relatives who had parkinsonism. Our results suggest that the novel SNCA A53E substitution is a causative mutation resulting clinically in parkinsonism and pathologically in severe multiple system atrophy- and PD-type phenotype.


Assuntos
Estudos de Associação Genética , Atrofia de Múltiplos Sistemas/genética , Mutação , Doença de Parkinson/genética , alfa-Sinucleína/genética , Adulto , Encéfalo/metabolismo , Encéfalo/patologia , Proteínas de Ligação a DNA/metabolismo , Feminino , Humanos , Pessoa de Meia-Idade , Atrofia de Múltiplos Sistemas/patologia , Neuritos/metabolismo , Doença de Parkinson/patologia , Linhagem , Fenótipo , Medula Espinal/metabolismo , Medula Espinal/patologia , alfa-Sinucleína/metabolismo
7.
Duodecim ; 129(16): 1654-60, 2013.
Artigo em Finlandês | MEDLINE | ID: mdl-24069634

RESUMO

According to investigations, nicotine and its agonists may prevent the development of Parkinson's disease and reduce motor symptoms and dyskinesias in Parkinson's disease. It was shown recently that a transdermal nicotine patch reliefs the symptoms in patients suffering from mild cognitive impairment. In Alzheimer's disease an alpha7-selective agonist has been found to have positive effects on cognitive symptoms. Mutations of nicotinic receptors are underlying certain nocturnal frontal lobe epilepsies. The partial nicotine agonist varenicline may alleviate ataxia symptoms.


Assuntos
Benzazepinas/farmacologia , Nicotina/farmacologia , Agonistas Nicotínicos/farmacologia , Quinoxalinas/farmacologia , Doença de Alzheimer/prevenção & controle , Ataxia/prevenção & controle , Disfunção Cognitiva/prevenção & controle , Epilepsia do Lobo Frontal/genética , Humanos , Mutação , Doença de Parkinson/prevenção & controle , Receptores Nicotínicos/genética , Dispositivos para o Abandono do Uso de Tabaco , Vareniclina
8.
Int Rev Neurobiol ; 95: 207-25, 2010.
Artigo em Inglês | MEDLINE | ID: mdl-21095464

RESUMO

Entacapone and tolcapone are reversible COMT inhibitors which have been approved for clinical use in patients with Parkinson disease (PD). Nebicapone is a third COMT inhibitor which has been studied in humans. COMT inhibitors are used in combination with levodopa and a dopa decarboxylase (DDC) inhibitor. Each of them has problems either in pharmacokinetics, pharmacodynamics, clinical efficacy, or in safety. All three inhibitors have short elimination half-lives, about 2-3h. Tolcapone is longer acting and more potent COMT inhibitor than entacapone; nebicapone lies in between. However, none of the present inhibitors cause a complete peripheral COMT inhibition. Tolcapone and nebicapone have increased more levodopa AUC than entacapone which is reflected also in their clinical efficacy. The most common adverse event with COMT inhibitors is dyskinesia which is usually managed by decreasing levodopa dose. The greatest problem with tolcapone and probably also with nebicapone is their liver toxicity which is not seen with entacapone. Tolcapone causes severe diarrhea more often than entacapone. Though the present COMT inhibitors have improved significantly the treatment of advanced PD patients, they still have several problems and weaknesses leaving room for developing better COMT inhibitors.


Assuntos
Benzofenonas/efeitos adversos , Inibidores de Catecol O-Metiltransferase , Catecóis/efeitos adversos , Nitrilas/efeitos adversos , Nitrofenóis/efeitos adversos , Doença de Parkinson/tratamento farmacológico , Antiparkinsonianos/efeitos adversos , Humanos , Levodopa/efeitos adversos , Tolcapona
9.
Eur J Clin Pharmacol ; 65(5): 443-55, 2009 May.
Artigo em Inglês | MEDLINE | ID: mdl-19229530

RESUMO

OBJECTIVES: To compare plasma levodopa concentrations after repeated doses of levodopa/carbidopa/entacapone (LCE) and levodopa/carbidopa (LC). METHODS: Open-label, randomized, two-period, active-controlled, cross-over study with four dosing regimens: groups I and II (healthy volunteers and Parkinson's disease patients) received levodopa 100 mg or 150 mg four times daily, respectively, and groups III and IV (healthy volunteers) received the same strengths of levodopa five times daily. Pharmacokinetic (PK) parameters determined for levodopa included Cmin, Cmax, Cmax - Cmin, AUC, t(1/2), and tmax. RESULTS: In healthy volunteers and PD patients, mean trough levels (Cmin), Cmax, and AUC of levodopa were, in general, significantly higher during LCE compared to LC administration. Compared to Cmin, Cmax, and AUC, differences between the treatments in variability of levodopa concentrations (Cmax - Cmin) were less consistent. CONCLUSIONS: The present results on the differences in levodopa PK between LCE and LC provide a basis to evaluate the relationship of levodopa PK and the induction of motor complications in an on-going study in early Parkinson's disease using similar dosing regimens.


Assuntos
Antiparkinsonianos/farmacocinética , Carbidopa/farmacocinética , Inibidores de Catecol O-Metiltransferase , Catecóis/farmacocinética , Levodopa/farmacocinética , Nitrilas/farmacocinética , Administração Oral , Adolescente , Adulto , Antiparkinsonianos/administração & dosagem , Antiparkinsonianos/sangue , Área Sob a Curva , Carbidopa/administração & dosagem , Carbidopa/sangue , Estudos de Casos e Controles , Catecol O-Metiltransferase/metabolismo , Catecóis/administração & dosagem , Catecóis/sangue , Estudos Cross-Over , Relação Dose-Resposta a Droga , Combinação de Medicamentos , Interações Medicamentosas , Feminino , Meia-Vida , Humanos , Levodopa/administração & dosagem , Levodopa/sangue , Masculino , Taxa de Depuração Metabólica , Nitrilas/administração & dosagem , Nitrilas/sangue , Adulto Jovem
10.
Duodecim ; 123(18): 2189, 2007.
Artigo em Finlandês | MEDLINE | ID: mdl-18020275
12.
Am J Hum Genet ; 77(3): 430-41, 2005 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-16080118

RESUMO

Mutations in the catalytic subunit of the mitochondrial DNA polymerase gamma (POLG) have been found to be an important cause of neurological disease. Recently, we and collaborators reported a new neurodegenerative disorder with autosomal recessive ataxia in four patients homozygous for two amino acid changes in POLG: W748S in cis with E1143G. Here, we studied the frequency of this allele and found it to be among the most common genetic causes of inherited ataxia in Finland. We identified 27 patients with mitochondrial recessive ataxia syndrome (MIRAS) from 15 Finnish families, with a carrier frequency in the general population of 1 : 125. Since the mutation pair W748S+E1143G has also been described in European patients, we examined the haplotypes of 13 non-Finnish, European patients with the W748S mutation. Haplotype analysis revealed that all the chromosomes carrying these two changes, in patients from Finland, Norway, the United Kingdom, and Belgium, originate from a common ancient founder. In Finland and Norway, long, common, northern haplotypes, outside the core haplotype, could be identified. Despite having identical homozygous mutations, the Finnish patients with this adult- or juvenile-onset disease had surprisingly heterogeneous phenotypes, albeit with a characteristic set of features, including ataxia, peripheral neuropathy, dysarthria, mild cognitive impairment, involuntary movements, psychiatric symptoms, and epileptic seizures. The high carrier frequency in Finland, the high number of patients in Norway, and the ancient European founder chromosome indicate that this newly identified ataxia should be considered in the first-line differential diagnosis of progressive ataxia syndromes.


Assuntos
DNA Polimerase Dirigida por DNA/genética , Evolução Molecular , Marcha Atáxica/genética , Genes Recessivos/genética , Mutação de Sentido Incorreto/genética , Adulto , Sequência de Bases , Clonagem Molecular , DNA Polimerase gama , Primers do DNA , Feminino , Finlândia/epidemiologia , Marcha Atáxica/epidemiologia , Frequência do Gene , Testes Genéticos , Haplótipos/genética , Humanos , Masculino , Pessoa de Meia-Idade , Dados de Sequência Molecular , Análise de Sequência de DNA
13.
Naunyn Schmiedebergs Arch Pharmacol ; 371(6): 480-91, 2005 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-16012872

RESUMO

It is well established that nicotine activates brain dopaminergic systems and in addition has neuroprotective actions. Thus, nicotinic acetylcholine receptor (nAChR) agonists might be beneficial in the treatment of Parkinson's disease, and it is important to study the interactions of nicotine with drugs affecting the nigrostriatal dopaminergic pathway. We used brain microdialysis to study the effects of nicotine on extracellular levels of dopamine (DA) and its metabolites in the rat dorsal striatum in combination with drugs inhibiting either DA uptake (nomifensine), catechol-O-methyltransferase (COMT; tolcapone), monoamine oxidase B (MAO-B; selegiline) or DA receptors (haloperidol). Nicotine (0.5 mg/kg, s.c.) modestly increased DA output, and this effect was antagonised by mecamylamine but not by hexamethonium. Nomifensine (3 mg/kg, i.p.) substantially further enhanced the nicotine-induced increase in DA output and nomifensine+nicotine also evoked a strong mecamylamine-sensitive ipsilateral rotational behaviour in 6-hydroxydopamine lesioned rats. Tolcapone (10 mg/kg, i.p.) did not alter DA output, but markedly decreased homovanillic acid (HVA) and increased 3,4-dihydroxyphenylacetic acid (DOPAC). Selegiline pretreatment (5 x 1 mg/kg, i.p.) significantly increased extracellular DA and decreased DOPAC and HVA. Haloperidol (0.1 mg/kg, s.c.) slightly increased DA output and more clearly DOPAC and HVA. Tolcapone, selegiline or haloperidol did not enhance the nicotine-induced DA output. These results indicate that the activation of nigrostriatal nAChRs induces a significant DA release in the striatum, which is potentiated by DA uptake inhibition but not by COMT, MAO-B or presynaptic DA receptor inhibition. Our findings therefore agree with the notion that the termination of the effect of DA in the synapse mainly occurs via neuronal reuptake. Thus, selective nAChR agonists, possibly in combination with a DA uptake inhibitor, might improve dopaminergic transmission in Parkinson's disease.


Assuntos
Corpo Estriado/efeitos dos fármacos , Dopamina/metabolismo , Nicotina/farmacologia , Agonistas Nicotínicos/farmacologia , Animais , Corpo Estriado/metabolismo , Inibidores da Captação de Dopamina/farmacologia , Masculino , Microdiálise , Atividade Motora/efeitos dos fármacos , Nomifensina/farmacologia , Ratos , Ratos Wistar , Rotação
14.
Neuroimage ; 27(2): 387-92, 2005 Aug 15.
Artigo em Inglês | MEDLINE | ID: mdl-15921933

RESUMO

Auditory event-related potential (ERP) components P50 and N100 are thought to index preattentive auditory processing underlying stimulus detection, whereas a subsequent component termed mismatch negativity (MMN) has been proposed to reflect comparison of incoming stimuli to a short-lived sensory memory trace of preceding sounds. Existing evidence suggests impairment of preattentive auditory processing in aging, which appears to be accompanied by decline of cholinergic activity. Previous studies indicate that scopolamine, which is a centrally acting muscarinic receptor antagonist, modulates preattentive auditory processing in young subjects. It has remained elusive, however, to which extent scopolamine affects preattentive auditory processing in aged subjects. We measured auditory responses simultaneously with electroencephalogram (EEG) and magnetoencephalogram (MEG) from nine non-demented elderly subjects after intravenous injection of scopolamine or glycopyrrolate, the latter being a peripherally acting cholinergic antagonist, using a double blind protocol. Scopolamine significantly delayed electric P50, both electric and magnetic N100 responses, whereas subsequent MMN and P200 responses were not altered by scopolamine. Our results indicate that the cholinergic system modulates auditory processing underlying stimulus detection in aging. In addition, auditory evoked responses appear to have different age-related sensitivity to cholinergic modulation. The combined MEG/EEG measurements using particularly auditory N100 response might offer an objective tool to monitor cholinergic activity in aging and Alzheimer's disease (AD).


Assuntos
Envelhecimento/psicologia , Atenção/fisiologia , Percepção Auditiva/fisiologia , Sistema Nervoso Parassimpático/fisiologia , Idoso , Idoso de 80 Anos ou mais , Atenção/efeitos dos fármacos , Percepção Auditiva/efeitos dos fármacos , Método Duplo-Cego , Potenciais Evocados Auditivos/efeitos dos fármacos , Potenciais Evocados Auditivos/fisiologia , Feminino , Lateralidade Funcional/fisiologia , Glicopirrolato/farmacologia , Humanos , Magnetoencefalografia , Masculino , Pessoa de Meia-Idade , Testes Neuropsicológicos , Sistema Nervoso Parassimpático/efeitos dos fármacos , Parassimpatolíticos/farmacologia , Escopolamina/farmacologia
16.
Clin Neurophysiol ; 114(10): 1902-7, 2003 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-14499752

RESUMO

OBJECTIVE: Scopolamine, a muscarinic receptor antagonist, can produce temporary cognitive impairments as well as electroencephalographic changes that partially resemble those observed in Alzheimer's disease. In order to test the sensitivity of spectral power and hemispheric coherence to changes in cholinergic transmission, we evaluated quantitative magnetoencephalogram (MEG) after intravenous injection of scopolamine. METHODS: MEG of 8 elderly healthy subjects (59-80 years) were measured with a whole-head magnetometer after intravenous injection of scopolamine. An injection of glycopyrrolate, a peripheral muscarinic antagonist, was used as the placebo in a double-blind, randomized, cross-over design. Spectral power and coherence were computed over 7 brain regions in 3 frequency bands. RESULTS: Scopolamine administration increased theta activity (4-8 Hz) and resulted in the abnormal pattern of MEG desynchronization in eyes-open vs. eyes-closed conditions in the alpha band (8-13 Hz). These effects were most prominent over the posterior regions. Interhemispheric and left intrahemispheric coherence was significantly decreased in the theta band (4-8 Hz). CONCLUSIONS: Spontaneous cortical activity at the theta and alpha range and functional coupling in the theta band are modulated by the cholinergic system. MEG may provide a tool for monitoring brain dynamics in neurological disorders associated with cholinergic abnormalities.


Assuntos
Potenciais Evocados Visuais/efeitos dos fármacos , Magnetoencefalografia , Antagonistas Muscarínicos/farmacologia , Escopolamina/farmacologia , Idoso , Idoso de 80 Anos ou mais , Análise de Variância , Mapeamento Encefálico , Córtex Cerebral/anatomia & histologia , Córtex Cerebral/efeitos dos fármacos , Córtex Cerebral/fisiologia , Estudos Cross-Over , Método Duplo-Cego , Olho , Feminino , Lateralidade Funcional , Glicopirrolato/farmacologia , Humanos , Injeções Intravenosas , Masculino , Pessoa de Meia-Idade , Agonistas Muscarínicos/farmacologia , Estimulação Luminosa
17.
Neuroreport ; 14(12): 1609-12, 2003 Aug 26.
Artigo em Inglês | MEDLINE | ID: mdl-14502085

RESUMO

We tested the possible role of dopaminergic activity in the processing of somatosensory afferent information in healthy humans. Somatosensory evoked magnetic fields (SEFs) were recorded in seven subjects in response to left median nerve stimulation. SEFs were obtained in all subjects after oral administration of 2 mg haloperidol, an antagonist to dopaminergic D2 receptors, and placebo, which were given in a randomized, double-blind cross-over design. SEFs were analyzed using a multiple equivalent current dipole (ECD) model, with one dipole at the right primary somatosensory cortex (SI) and at both left and right secondary somatosensory cortices (SII). The earliest responses from SI, peaking at about 20 ms (N20m) and 35 ms (P35m), were not affected by haloperidol. A later deflection peaking at about 75 ms (P60m), however, was slightly reduced (p < 0.05). Responses arising from SII were not significantly changed. The results suggest that dopaminergic activity may be involved in modulating somatosensory processing after the initial stages of cortical activation.


Assuntos
Antagonistas de Dopamina/farmacologia , Antagonistas dos Receptores de Dopamina D2 , Campos Eletromagnéticos , Potenciais Somatossensoriais Evocados/efeitos dos fármacos , Córtex Somatossensorial/efeitos dos fármacos , Adulto , Estudos Cross-Over , Método Duplo-Cego , Potenciais Somatossensoriais Evocados/fisiologia , Feminino , Haloperidol/farmacologia , Humanos , Masculino , Receptores de Dopamina D2/fisiologia , Córtex Somatossensorial/fisiologia , Estatísticas não Paramétricas
19.
Clin Neurophysiol ; 113(12): 1894-902, 2002 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-12464326

RESUMO

OBJECTIVE: Dopaminergic function has been closely associated with attentional performance, but its precise role has remained elusive. METHODS: Electrophysiological and behavioral methods were used to assess the effects of dopamine D2-receptor antagonist haloperidol on involuntary attention shifting using a randomized, double-blind, placebo-controlled cross-over design. Eleven subjects were instructed to discriminate equiprobable 200 and 400ms tones in a forced-choice reaction-time (RT) task during simultaneous measurement of whole-head magnetoencephalography and high-resolution electroencephalography. RESULTS: Occasional changes in task-irrelevant tone frequency (10% increase or decrease) caused marked distraction on behavioral performance, as shown by significant RT increases to deviant stimuli and subsequent standard tones. Furthermore, while the standard tones elicited distinct P1-N1-P2-N2-P3 waveforms, deviant tones elicited additional mismatch negativity (MMN), P3a, and reorienting negativity (RON) responses, indexing brain events associated with involuntary attention shifting. While haloperidol did not affect the source loci of the responses of magnetic N1 and MMN, the amplitude of the electric P3a and that of RON were significantly reduced and the latency of magnetic RON were delayed following haloperidol administration. CONCLUSIONS: The present results suggest that dopamine modulates involuntary attention shifting to task-irrelevant deviant events. It appears that dopamine may disrupt the subsequent re-orienting efforts to the relevant task after distraction.


Assuntos
Atenção/fisiologia , Dopamina/fisiologia , Magnetoencefalografia/métodos , Adulto , Análise de Variância , Atenção/efeitos dos fármacos , Estudos Cross-Over , Método Duplo-Cego , Eletroencefalografia/efeitos dos fármacos , Eletroencefalografia/métodos , Fenômenos Eletromagnéticos , Feminino , Haloperidol/farmacologia , Humanos , Magnetoencefalografia/efeitos dos fármacos , Masculino , Orientação/efeitos dos fármacos , Orientação/fisiologia , Tempo de Reação/efeitos dos fármacos , Tempo de Reação/fisiologia
20.
Br J Clin Pharmacol ; 54(4): 363-71, 2002 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-12392583

RESUMO

AIMS: Entacapone is a peripherally acting catechol-O-methyltransferase (COMT) inhibitor. To improve the benefits of oral L-dopa in the treatment of Parkinson's disease (PD), entacapone is administered as a 200 mg dose with each daily dose of L-dopa. This study evaluated the effects of entacapone 200 mg on the pharmacokinetics and metabolism of L-dopa given as standard release L-dopa/carbidopa. METHODS: Six different doses of l-dopa/carbidopa were investigated in this placebo-controlled, double-blind (regarding entacapone), randomized, single-dose study in 46 young healthy males. The subjects were divided into three groups (n = 14-16). Two different L-dopa/carbidopa doses were administered to each subject (50/12.5 mg and 150/37.5 mg, or 100/10 mg and 100/25 mg, or 200/50 mg and 250/25 mg). Each dose was given on two occasions; simultaneously with entacapone or with placebo, in random order, on two consecutive study visits, separated by a washout period of at least 3 weeks (four-way crossover design). Serial blood samples were drawn before dosing and up to 24 h after the dose and pharmacokinetic parameters of L-dopa, its metabolites, carbidopa, and entacapone were determined. RESULTS: Entacapone increased the AUC(0,12 h) of L-dopa to a similar extent at all doses of L-dopa/carbidopa, that is by about 30-40% compared with placebo (P < 0.001, 95% CI 0.15, 0.40). When evaluated as the ratio of geometric means, entacapone slightly decreased the mean C(max) values for L-dopa at all L-dopa/carbidopa doses compared with placebo. When given with entacapone, higher plasma concentrations of L-dopa were maintained for a longer period at all doses of L-dopa/carbidopa. Entacapone also decreased the peripheral formation of 3-O-methyldopa (3-OMD) to about 55-60% of the placebo treatment level (P < 0.001, 95% CI -0.72, -0.35) and increased the mean AUC(0,12 h) of 3,4-dihydroxy-phenylacetic acid (DOPAC) 2-2.6-fold compared with placebo (P < 0.001, 95% CI 0.60, 1.10). The mean AUC(0,12 h) of 3-methoxy-4-hydroxy-phenylacetic acid (HVA) following entacapone was approximately 65-75% of that observed with placebo (P < 0.001-0.05, 95% CI -0.76, -0.01) at each L-dopa/carbidopa dose except the 50/12.5 mg dose (P > 0.05, 95% CI -0.59, 0.05). The metabolic ratios (MR, AUC metabolite/AUC L-dopa) also confirmed that entacapone significantly decreased the proportion of 3-OMD (P < 0.001, 95% CI -0.85, -0.68) and HVA (P < 0.001, 95% CI -1.01, -0.18) in plasma at each L-dopa/carbidopa dose, whereas the AUC DOPAC/AUC L-dopa ratio was increased again at all doses (P < 0.001, 95% CI 0.26, 0.90). Entacapone did not significantly affect the pharmacokinetics of carbidopa at any of the doses, nor did L-dopa/carbidopa affect the pharmacokinetics of entacapone. CONCLUSIONS: The 200 mg dose of entacapone similarly and significantly increases the AUC of L-dopa by changing the metabolic balance of L-dopa independent of the L-dopa/carbidopa dose and therefore entacapone is likely to have a similar L-dopa potentiating effect independent of L-dopa dose.


Assuntos
Antiparkinsonianos/farmacologia , Catecóis/farmacologia , Levodopa/farmacocinética , Adulto , Análise de Variância , Antiparkinsonianos/administração & dosagem , Antiparkinsonianos/farmacocinética , Disponibilidade Biológica , Catecóis/administração & dosagem , Catecóis/farmacocinética , Estudos Cross-Over , Relação Dose-Resposta a Droga , Método Duplo-Cego , Humanos , Levodopa/administração & dosagem , Levodopa/sangue , Masculino , Nitrilas
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