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1.
Org Lett ; 21(20): 8369-8372, 2019 Oct 18.
Artigo em Inglês | MEDLINE | ID: mdl-31599597

RESUMO

An improved scalable synthesis of orthogonally functionalized methoxyaspartate, the chiral hinge region element in cystobactamids, is reported. This improvement sets the stage for the total synthesis of four new cystobactamids along with cystobactamid 861-2, whose antibacterial properties are determined and compared. The cyano derivative of cystobactamide 861-2 shows superior antibacterial activity against Gram-negative bacteria to any natural cystobactamide tested so far.

2.
Ann Intern Med ; 170(9): 667-668, 2019 May 07.
Artigo em Inglês | MEDLINE | ID: mdl-31060066
3.
Org Lett ; 21(5): 1359-1363, 2019 03 01.
Artigo em Inglês | MEDLINE | ID: mdl-30735398

RESUMO

Total synthesis of cystobactamid 920-1 and its epimer has allowed an unambiguous assignment of the relative and absolute configuration of the natural product. A careful structural analysis of each isomer using both NMR and computational techniques also prompted a constitutional revision of the structures originally reported for cystobactamids 920-1 and 920-2, and has provided further insight into the unique conformational preferences of the cystobactamid family.

4.
Curr Opin Allergy Clin Immunol ; 18(5): 404-410, 2018 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-30020255

RESUMO

PURPOSE OF REVIEW: The purpose of this review was to explore recent developments in the study of ocular cosmetics, as they pertain to adverse reactions that can be attributed to them. RECENT FINDINGS: Immunologically mediated adverse reactions to cosmetics are most commonly the result of sensitization to preservatives, fragrances and dyes used in these products. Metals such as nickel, cobalt, chromium and lead are used in products such as eye shadows and eye liners as well as toy makeup sets in amounts greater than the recommended amount of 1 ppm. Cosmetics make up the majority of fragrance-induced contact dermatitis. Recently, a free smartphone app was developed by American Contact Dermatitis Society that holds promise in better enabling patients to utilize their patch test data while shopping for cosmetics. SUMMARY: Both immediate and delayed hypersensitivity reactions linked to cosmetics are often the result of sensitization to preservatives, fragrances and additives in the products themselves. Despite significant advances in our understanding of these reactions, further research will be necessary to elucidate the mechanisms behind these reactions and bring this knowledge to the bedside as to improve patient care with potential cosmetic-based related allergic disorders.

5.
Curr Opin Allergy Clin Immunol ; 18(5): 387-392, 2018 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-30020257

RESUMO

PURPOSE OF REVIEW: The purpose of the article is to provide a historical overview of literature regarding pollen sensitization and ocular allergy with an emphasis on developments that have occurred over the past 5 years. RECENT FINDINGS: Currently, pollen studies have examined the molecular and cellular pathways involved in initiating allergic conjunctivitis to find targets for therapeutics. Studies have also documented the threshold, linear increase and plateau point in the relationship between pollen levels and allergic conjunctivitis symptoms. SUMMARY: Traditionally, intact pollen grains are counted as a means of correlating patient symptoms to allergen exposure. However, establishing a dose-response relationship between pollen grain exposure and allergic conjunctivitis has proven to be difficult. It has been observed that ocular allergies induce a two-fold response including early-phase and late-phase IgE-mediated reactions. Sensitization itself is a combination of pollen exposure over time in genetically predisposed individual. However, symptoms appear to reach an asymptotic point at which clinical severity plateaus. More studies are needed to clearly define differences in pollen sensitization by plant species.

6.
Ann Allergy Asthma Immunol ; 121(3): 375, 2018 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-29969663
7.
Mol Plant ; 11(4): 607-622, 2018 04 02.
Artigo em Inglês | MEDLINE | ID: mdl-29409859

RESUMO

RNA secondary structure plays a critical role in gene regulation. Rice (Oryza sativa) is one of the most important food crops in the world. However, RNA structure in rice has scarcely been studied. Here, we have successfully generated in vivo Structure-seq libraries in rice. We found that the structural flexibility of mRNAs might associate with the dynamics of biological function. Higher N6-methyladenosine (m6A) modification tends to have less RNA structure in 3' UTR, whereas GC content does not significantly affect in vivo mRNA structure to maintain efficient biological processes such as translation. Comparative analysis of RNA structurome between rice and Arabidopsis revealed that higher GC content does not lead to stronger structure and less RNA structural flexibility. Moreover, we found a weak correlation between sequence and structure conservation of the orthologs between rice and Arabidopsis. The conservation and divergence of both sequence and in vivo RNA structure corresponds to diverse and specific biological processes. Our results indicate that RNA secondary structure might offer a separate layer of selection to the sequence between monocot and dicot. Therefore, our study implies that RNA structure evolves differently in various biological processes to maintain robustness in development and adaptational flexibility during angiosperm evolution.

8.
Org Biomol Chem ; 16(8): 1351-1358, 2018 Feb 21.
Artigo em Inglês | MEDLINE | ID: mdl-29404557

RESUMO

Two putative structures of spongosoritin A, with syn (6R,8R) and anti (6S,8R) configurations, were each synthesised in a total of 11 linear steps with only 8 purification procedures. The key steps in our strategy included Evans alkylation and olefin dihydroxylation to install the C8 and C6 stereocentres, a transacetalisation/dehydration cascade to construct the furanylidene core, and chromatographic separation of 9E- and 9Z-isomers of the final compounds with silver nitrate impregnated silica. Comparison of the 1H and 13C NMR data for the synthetic syn- and anti-isomers to that reported for the natural product revealed that the relative configuration of spongosoritin A is syn. The absolute stereochemistry was also confirmed as 6R,8R based on optical rotation measurements where the synthetic syn (6R,8R) and natural product had the same sign of optical rotation (negative).

9.
Mov Disord ; 33(1): 136-145, 2018 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-29124784

RESUMO

OBJECTIVE: We sought to determine whether abnormalities in emotion processing underlie functional (psychogenic) dystonia, one of the most common functional movement disorders. METHODS: Motor and emotion circuits were examined in 12 participants with functional dystonia, 12 with primary organic dystonia, and 25 healthy controls using functional magnetic resonance imaging at 4T and a finger-tapping task (motor task), a basic emotion-recognition task (emotional faces task), and an intense-emotion stimuli task. RESULTS: There were no differences in motor task activation between groups. In the faces task, when compared with the other groups, functional dystonia patients showed areas of decreased activation in the right middle temporal gyrus and bilateral precuneus and increased activation in the right inferior frontal gyrus, bilateral occipital cortex and fusiform gyrus, and bilateral cerebellum. In the intense-emotion task, when compared with the other groups, functional dystonia patients showed decreased activation in the left insular and left motor cortices (compared to organic dystonia, they showed an additional decrease in activation in the right opercular cortex and right motor cortex) and increased activation in the left fusiform gyrus. CONCLUSIONS: Functional dystonia patients exhibited stimulus-dependent altered activation in networks involved in motor preparation and execution, spatial cognition, and attentional control. These results support the presence of network dysfunction in functional dystonia. © 2017 International Parkinson and Movement Disorder Society.

10.
Neuroimage Clin ; 17: 179-187, 2018.
Artigo em Inglês | MEDLINE | ID: mdl-29085776

RESUMO

BACKGROUND: Despite its high prevalence and associated disability, the neural correlates of emotion processing in patients with functional (psychogenic) tremor (FT), the most common functional movement disorder, remain poorly understood. METHODS: In this cross sectional functional magnetic resonance imaging (fMRI) study at 4T, 27 subjects with FT, 16 with essential tremor (ET), and 25 healthy controls (HCs) underwent a finger-tapping motor task, a basic-emotion task, and an intense-emotion task to probe motor and emotion circuitries. Anatomical and functional MRI data were processed with FSL (FMRIB Software Library) and AFNI (Analysis of Functional Neuroimages), followed by seed-to-seed connectivity analyses using anatomical regions defined from the Harvard-Oxford subcortical atlas; all analyses were corrected for multiple comparisons. RESULTS: After controlling for depression scores and correcting for multiple comparisons, the FT group showed increased activation in the right cerebellum compared to ET during the motor task; and increased activation in the paracingulate gyrus and left Heschl's gyrus compared with HC with decreased activation in the right precentral gyrus compared with ET during the basic-emotion task. No significant differences were found after adjusting for multiple comparisons during the intense-emotion task but increase in connectivity between the left amygdala and left middle frontal gyrus survived corrections in the FT subjects during this task, compared to HC. CONCLUSIONS: In response to emotional stimuli, functional tremor is associated with alterations in activation and functional connectivity in networks involved in emotion processing and theory of mind. These findings may be relevant to the pathophysiology of functional movement disorders.


Assuntos
Encéfalo/fisiopatologia , Emoções/fisiologia , Tremor/fisiopatologia , Adulto , Idoso , Mapeamento Encefálico , Cerebelo/fisiopatologia , Estudos Transversais , Expressão Facial , Reconhecimento Facial/fisiologia , Feminino , Humanos , Imagem por Ressonância Magnética , Masculino , Pessoa de Meia-Idade , Atividade Motora , Vias Neurais/fisiopatologia
11.
J Exp Bot ; 68(18): 5103-5116, 2017 Nov 02.
Artigo em Inglês | MEDLINE | ID: mdl-29106622

RESUMO

Plant roots have the potential capacity to grow almost indefinitely if meristematic and lateral branching is sustained. In a genetic screen we identified an Arabidopsis mutant showing limited root growth (lrg1) due to defects in cell division and elongation in the root meristem. Positional cloning determined that lrg1 affects an alpha-1,2-mannosyltransferase gene, LEW3, involved in protein N-glycosylation. The lrg1 mutation causes a synonymous substitution that alters the correct splicing of the fourth intron in LEW3, causing a mix of wild-type and truncated protein. LRG1 RNA missplicing in roots and short root phenotypes in lrg1 are light-intensity dependent. This mutation disrupts a GC-base pair in a three-base-pair stem with a four-nucleotide loop, which seems to be necessary for correct LEW3 RNA splicing. We found that the lrg1 short root phenotype correlates with high levels of reactive oxygen species and low pH in the apoplast. Proteomic analyses of N-glycosylated proteins identified GLU23/PYK10 and PRX34 as N-glycosylation targets of LRG1 activity. The lrg1 mutation reduces the positive interaction between Arabidopsis and Serendipita indica. A prx34 mutant showed a significant reduction in root growth, which is additive to lrg1. Taken together our work highlights the important role of N-glycosylation in root growth and development.


Assuntos
Proteínas de Arabidopsis/metabolismo , Arabidopsis/genética , Basidiomycota/fisiologia , Manosiltransferases/metabolismo , Peroxidases/metabolismo , beta-Glucosidase/metabolismo , Arabidopsis/crescimento & desenvolvimento , Arabidopsis/fisiologia , Arabidopsis/efeitos da radiação , Proteínas de Arabidopsis/genética , Divisão Celular , Glicosilação , Concentração de Íons de Hidrogênio , Íntrons/genética , Manosiltransferases/genética , Meristema/genética , Meristema/crescimento & desenvolvimento , Meristema/efeitos da radiação , Mutação , Peroxidases/genética , Fenótipo , Raízes de Plantas/genética , Raízes de Plantas/crescimento & desenvolvimento , Raízes de Plantas/efeitos da radiação , Proteômica , Processamento de RNA , Espécies Reativas de Oxigênio/metabolismo , Plântula/genética , Plântula/crescimento & desenvolvimento , Plântula/efeitos da radiação , beta-Glucosidase/genética
12.
Bipolar Disord ; 19(4): 259-272, 2017 06.
Artigo em Inglês | MEDLINE | ID: mdl-28574156

RESUMO

OBJECTIVES: Individualized treatment for bipolar disorder based on neuroimaging treatment targets remains elusive. To address this shortcoming, we developed a linguistic machine learning system based on a cascading genetic fuzzy tree (GFT) design called the LITHium Intelligent Agent (LITHIA). Using multiple objectively defined functional magnetic resonance imaging (fMRI) and proton magnetic resonance spectroscopy (1 H-MRS) inputs, we tested whether LITHIA could accurately predict the lithium response in participants with first-episode bipolar mania. METHODS: We identified 20 subjects with first-episode bipolar mania who received an adequate trial of lithium over 8 weeks and both fMRI and 1 H-MRS scans at baseline pre-treatment. We trained LITHIA using 18 1 H-MRS and 90 fMRI inputs over four training runs to classify treatment response and predict symptom reductions. Each training run contained a randomly selected 80% of the total sample and was followed by a 20% validation run. Over a different randomly selected distribution of the sample, we then compared LITHIA to eight common classification methods. RESULTS: LITHIA demonstrated nearly perfect classification accuracy and was able to predict post-treatment symptom reductions at 8 weeks with at least 88% accuracy in training and 80% accuracy in validation. Moreover, LITHIA exceeded the predictive capacity of the eight comparator methods and showed little tendency towards overfitting. CONCLUSIONS: The results provided proof-of-concept that a novel GFT is capable of providing control to a multidimensional bioinformatics problem-namely, prediction of the lithium response-in a pilot data set. Future work on this, and similar machine learning systems, could help assign psychiatric treatments more efficiently, thereby optimizing outcomes and limiting unnecessary treatment.


Assuntos
Sintomas Comportamentais , Transtorno Bipolar , Resistência a Medicamentos , Compostos de Lítio , Imagem por Ressonância Magnética/métodos , Espectroscopia de Prótons por Ressonância Magnética/métodos , Adolescente , Adulto , Antimaníacos/administração & dosagem , Antimaníacos/efeitos adversos , Inteligência Artificial , Sintomas Comportamentais/diagnóstico , Sintomas Comportamentais/tratamento farmacológico , Transtorno Bipolar/diagnóstico , Transtorno Bipolar/tratamento farmacológico , Transtorno Bipolar/psicologia , Manual Diagnóstico e Estatístico de Transtornos Mentais , Monitoramento de Medicamentos/métodos , Feminino , Lógica Fuzzy , Humanos , Compostos de Lítio/administração & dosagem , Compostos de Lítio/efeitos adversos , Masculino , Imagem Multimodal/métodos , Projetos Piloto , Valor Preditivo dos Testes , Prognóstico
13.
J Affect Disord ; 209: 246-253, 2017 02.
Artigo em Inglês | MEDLINE | ID: mdl-27936454

RESUMO

BACKGROUND: Studying youth at high risk of developing bipolar disorder may clarify neurobiological factors associated with vulnerability to this illness. We present here a baseline characterization of brain structure in youth at-risk for bipolar disorder. METHODS: Magnetic resonance images were obtained from 115 child and adolescent offspring of bipolar disorder type I subjects and 57 healthy child and adolescent offspring of healthy parents (healthy control offspring). Offspring of parents with bipolar disorder were divided into healthy bipolar offspring (n=47) or symptomatic bipolar offspring (n=68), according to presence or absence of childhood-onset psychopathology. All bipolar offspring were free of major mood and psychotic disorders. Gray (GM) and white matter (WM) volumes were compared between groups using voxel-based morphometry. RESULTS: No differences in GM volumes were found across groups. Healthy bipolar offspring presented with decreased WM volumes in areas of the right frontal, temporal and parietal lobes, and in the left temporal and parietal lobes compared to healthy control offspring. Symptomatic bipolar offspring did not present with any differences in WM volumes compared to either healthy bipolar offspring or healthy control offspring. LIMITATIONS: Cross-sectional design and heterogeneous sample of symptomatic bipolar offspring. CONCLUSIONS: WM volume decreases in areas of the frontal, occipital, and parietal lobes are present in bipolar offspring prior to the development of any psychiatric symptoms, and may be a correlate of familial risk to bipolar disorder. In this large cohort, we have not found evidence for regional GM volume abnormalities as an endophenotype for bipolar disorder.


Assuntos
Transtorno Bipolar , Encéfalo/diagnóstico por imagem , Filho de Pais Incapacitados , Pais , Substância Branca/diagnóstico por imagem , Adolescente , Adulto , Transtorno Bipolar/diagnóstico , Criança , Estudos Transversais , Endofenótipos , Feminino , Humanos , Imagem por Ressonância Magnética , Masculino , Tamanho do Órgão/fisiologia
14.
Bioinformatics ; 33(2): 306-308, 2017 01 15.
Artigo em Inglês | MEDLINE | ID: mdl-27663500

RESUMO

Most RNA molecules form internal base pairs, leading to a folded secondary structure. Some of these structures have been demonstrated to be functionally significant. High-throughput RNA structure chemical probing methods generate millions of sequencing reads to provide structural constraints for RNA secondary structure prediction. At present, processed data from these experiments are difficult to access without computational expertise. Here we present FoldAtlas, a web interface for accessing raw and processed structural data across thousands of transcripts. FoldAtlas allows a researcher to easily locate, view, and retrieve probing data for a given RNA molecule. We also provide in silico and in vivo secondary structure predictions for comparison, visualized in the browser as circle plots and topology diagrams. Data currently integrated into FoldAtlas are from a new high-depth Structure-seq data analysis in Arabidopsis thaliana, released with this work. AVAILABILITY AND IMPLEMENTATION: The FoldAtlas website can be accessed at www.foldatlas.com Source code is freely available at github.com/mnori/foldatlas under the MIT license. Raw reads data are available under the NCBI SRA accession SRP066985. CONTACT: yiliang.ding@jic.ac.uk or matthew.norris@jic.ac.ukSupplementary information: Supplementary data are available at Bioinformatics online.


Assuntos
Bases de Dados de Ácidos Nucleicos , RNA/metabolismo , Arabidopsis/metabolismo , Simulação por Computador , Conformação de Ácido Nucleico , RNA/química , RNA de Plantas/química , RNA de Plantas/metabolismo , Análise de Sequência de RNA
15.
Bipolar Disord ; 18(6): 490-501, 2016 09.
Artigo em Inglês | MEDLINE | ID: mdl-27647671

RESUMO

OBJECTIVES: We tested the hypothesis that, with treatment, functional magnetic resonance imaging (fMRI) regional brain activation in first-episode mania would normalize - i.e., that differences from healthy subjects would diminish over time, and would be associated with clinical remission status, potentially identifying neuroanatomic treatment response markers. METHODS: Forty-two participants with bipolar I disorder were recruited during their first manic episode, pseudo-randomized to open-label lithium or quetiapine, and followed for 8 weeks. fMRI scans were obtained at baseline and then after 1 and 8 weeks of treatment, while participants performed a continuous performance task with emotional distracters. Healthy participants received fMRI scans at these same intervals. Specific region-of-interest (ROI) activations within prefrontal emotional networks were assessed as potential measures of treatment response. RESULTS: ROI data were reduced using exploratory factor analysis, which identified five factors that were organizationally consistent with functional anatomic models of human emotion modulation. Half of the participants with bipolar disorder achieved remission by Week 8 and were contrasted with the other half that did not. Analyses demonstrated that, in the bipolar disorder group in general, treatment led to decreases in activation across brain regions toward healthy subject values. However, differences in activation changes were observed between subjects with bipolar disorder who did or did not achieve remission in subcortical and amygdala factors. CONCLUSIONS: These findings provide evidence for potential neuroanatomic treatment response markers in first-episode bipolar disorder.


Assuntos
Tonsila do Cerebelo , Transtorno Bipolar , Lítio/uso terapêutico , Imagem por Ressonância Magnética/métodos , Fumarato de Quetiapina/uso terapêutico , Adulto , Tonsila do Cerebelo/diagnóstico por imagem , Tonsila do Cerebelo/fisiopatologia , Antimaníacos/uso terapêutico , Transtorno Bipolar/diagnóstico , Transtorno Bipolar/psicologia , Transtorno Bipolar/terapia , Emoções/fisiologia , Cuidado Periódico , Feminino , Humanos , Masculino , Escalas de Graduação Psiquiátrica , Análise e Desempenho de Tarefas , Resultado do Tratamento
16.
J Org Chem ; 81(15): 6848-54, 2016 08 05.
Artigo em Inglês | MEDLINE | ID: mdl-27359169

RESUMO

A chemoselective oxidative cleavage of synthetic gracilioether B, 11-epi-gracilioether C benzoate, and des-hydroxygracilioether C with pyridinium chlorochromate, which proceeds with loss of the furanyl acetate, has enabled total synthesis and stereochemical elucidation of the marine sponge metabolites (4R,6R)-plakilactone C, (4R,6R,9R)-plakilactone B, and (4R,6R)-des-hydroxyplakilactone B. des-Hydroxygracilioether C, the putative biosynthetic precursor to hippolachnin A, was also found to undergo a facile ene cyclization on treatment with SnCl4.

17.
Nat Prod Rep ; 33(7): 861-80, 2016 Jul 28.
Artigo em Inglês | MEDLINE | ID: mdl-27163115

RESUMO

Covering: up to early 2016Marine sponges are widely known as a rich source of natural products, especially of polyketide origin, with a wealth of chemical diversity. Within this vast collection, peroxide and peroxide-derived secondary metabolites have attracted significant interest in the fields of natural product isolation and chemical synthesis for their structural distinction and promising in vitro antimicrobial and anticancer properties. In this review, peroxide and peroxide-derived polyketide metabolites isolated from marine sponges in the past 35 years are summarised. Efforts toward their synthesis are detailed with a focus on methods that utilise or attempt to elucidate the complex biosynthetic interrelationships of these compounds beyond enzymatic polyketide synthesis. Recent isolations, advances in synthetic methodology and theories of biogenesis are highlighted and critically evaluated.


Assuntos
Produtos Biológicos/síntese química , Peróxidos/síntese química , Policetídeo Sintases/metabolismo , Policetídeos/síntese química , Poríferos/química , Animais , Anti-Infecciosos , Produtos Biológicos/química , Biologia Marinha , Estrutura Molecular , Peróxidos/química , Policetídeos/química
18.
J Clin Exp Neuropsychol ; 37(6): 563-70, 2015.
Artigo em Inglês | MEDLINE | ID: mdl-26059389

RESUMO

INTRODUCTION: Previous research has shown that performance on cognitive tasks administered in the scanner can be altered by the scanner environment. There are no previous studies that have investigated the impact of scanner noise using a well-validated measure of affective change. The goal of this study was to determine whether performance on an affective attentional task or emotional response to the task would change in the presence of distracting acoustic noise, such as that encountered in a magnetic resonance imaging (MRI) environment. METHOD: Thirty-four young adults with no self-reported history of neurologic disorder or mental illness completed three blocks of the affective Posner task outside of the scanner. The task was meant to induce frustration through monetary contingencies and rigged feedback. Participants completed a Self-Assessment Manikin at the end of each block to rate their mood, arousal level, and sense of dominance. During the task, half of the participants heard noise (recorded from a 4T MRI system), and half heard no noise. RESULTS: The affective Posner task led to significant reductions in mood and increases in arousal in healthy participants. The presence of scanner noise did not impact task performance; however, individuals in the noise group did report significantly poorer mood throughout the task. CONCLUSIONS: The results of the present study suggest that the acoustic qualities of MRI enhance frustration effects on an affective attentional task and that scanner noise may influence mood during similar functional magnetic resonance imaging (fMRI) tasks.


Assuntos
Afeto/fisiologia , Atenção/fisiologia , Neuroimagem Funcional/normas , Imagem por Ressonância Magnética/efeitos adversos , Ruído/efeitos adversos , Desempenho Psicomotor/fisiologia , Adolescente , Adulto , Feminino , Humanos , Masculino , Adulto Jovem
19.
Org Lett ; 17(3): 668-71, 2015 Feb 06.
Artigo em Inglês | MEDLINE | ID: mdl-25621375

RESUMO

Total syntheses of the marine polyketide metabolites gracilioethers B and C have been realized in 9 steps (40% overall yield) and 10 steps (34% overall yield), respectively. The [2(5H)-furanylidene]ethanoate (furanylidene) motif was constructed in a transacetalization/dehydration cascade of an advanced ß-ketoester intermediate, which was designed to mimic a postulated biosynthetic precursor to the natural products. The relative and absolute configurations of gracilioethers B and C are confirmed as (6R,8R) and (6R,8R,11S), respectively.


Assuntos
Furanos/química , Furanos/síntese química , Produtos Biológicos , Biomimética , Estrutura Molecular , Estereoisomerismo
20.
Neurology ; 84(8): 794-802, 2015 Feb 24.
Artigo em Inglês | MEDLINE | ID: mdl-25632091

RESUMO

OBJECTIVE: To examine the effect of cost, a traditionally "inactive" trait of intervention, as contributor to the response to therapeutic interventions. METHODS: We conducted a prospective double-blind study in 12 patients with moderate to severe Parkinson disease and motor fluctuations (mean age 62.4 ± 7.9 years; mean disease duration 11 ± 6 years) who were randomized to a "cheap" or "expensive" subcutaneous "novel injectable dopamine agonist" placebo (normal saline). Patients were crossed over to the alternate arm approximately 4 hours later. Blinded motor assessments in the "practically defined off" state, before and after each intervention, included the Unified Parkinson's Disease Rating Scale motor subscale, the Purdue Pegboard Test, and a tapping task. Measurements of brain activity were performed using a feedback-based visual-motor associative learning functional MRI task. Order effect was examined using stratified analysis. RESULTS: Although both placebos improved motor function, benefit was greater when patients were randomized first to expensive placebo, with a magnitude halfway between that of cheap placebo and levodopa. Brain activation was greater upon first-given cheap but not upon first-given expensive placebo or by levodopa. Regardless of order of administration, only cheap placebo increased activation in the left lateral sensorimotor cortex and other regions. CONCLUSION: Expensive placebo significantly improved motor function and decreased brain activation in a direction and magnitude comparable to, albeit less than, levodopa. Perceptions of cost are capable of altering the placebo response in clinical studies. CLASSIFICATION OF EVIDENCE: This study provides Class III evidence that perception of cost is capable of influencing motor function and brain activation in Parkinson disease.


Assuntos
Antiparkinsonianos/administração & dosagem , Antiparkinsonianos/economia , Doença de Parkinson/tratamento farmacológico , Doença de Parkinson/economia , Efeito Placebo , Idoso , Efeitos Psicossociais da Doença , Estudos Cross-Over , Agonistas de Dopamina/administração & dosagem , Agonistas de Dopamina/economia , Método Duplo-Cego , Feminino , Humanos , Injeções Subcutâneas , Levodopa/administração & dosagem , Levodopa/economia , Masculino , Pessoa de Meia-Idade , Doença de Parkinson/psicologia , Estudos Prospectivos , Resultado do Tratamento
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