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1.
Cerebellum ; 21(6): 963-975, 2022 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-34855135

RESUMO

To identify gait and balance measures that are responsive to change during the timeline of a clinical trial in Friedreich ataxia (FRDA), we administered a battery of potential measures three times over a 12-month period. Sixty-one ambulant individuals with FRDA underwent assessment of gait and balance at baseline, 6 months and 12 months. Outcomes included GAITRite® spatiotemporal gait parameters; Biodex Balance System Postural Stability Test (PST) and Limits of Stability; Berg Balance Scale (BBS); Timed 25-Foot Walk Test; Dynamic Gait Index (DGI); SenseWear MF Armband step and energy activity; and the Friedreich Ataxia Rating Scale Upright Stability Subscale (FARS USS). The standardised response mean (SRM) or correlation coefficients were reported as effect size indices for comparison of internal responsiveness. Internal responsiveness was also analysed in subgroups. SenseWear Armband daily step count had the largest effect size of all the variables over 6 months (SRM = -0.615), while the PST medial-lateral index had the largest effect size (SRM = 0.829) over 12 months. The FARS USS (SRM = 0.824) and BBS (SRM = -0.720) were the only outcomes able to detect change over 12 months in all subgroups. The DGI was the most responsive outcome in children, detecting a mean change of -2.59 (95% CI -3.52 to -1.66, p < 0.001, SRM = -1.429). In conclusion, the FARS USS and BBS are highly responsive and can detect change in a wide range of ambulant individuals with FRDA. However, therapeutic effects in children may be best measured by the DGI.


Assuntos
Ataxia de Friedreich , Criança , Humanos , Ataxia de Friedreich/diagnóstico , Índice de Gravidade de Doença , Marcha/fisiologia , Progressão da Doença , Equilíbrio Postural/fisiologia
2.
Addict Biol ; 27(3): e13174, 2022 05.
Artigo em Inglês | MEDLINE | ID: mdl-35470555

RESUMO

Alcohol use disorder is characterised by disrupted reward learning, underpinned by dysfunctional cortico-striatal reward pathways, although relatively little is known about the biology of reward processing in populations who engage in risky alcohol use. Cues that trigger reward anticipation can be categorized according to their learnt valence (i.e., positive vs. negative outcomes) and motivational salience (i.e., incentive vs. neutral cues). Separating EEG signals associated with these dimensions is challenging because of their inherent collinearity, but the recent application of machine learning methods to single EEG trials affords a solution. Here, the Alcohol Use Disorders Identification Test (AUDIT) was used to quantify risky alcohol use, with participants split into high alcohol (HA) (n = 22, mean AUDIT score: 13.82) and low alcohol (LA) (n = 22, mean AUDIT score: 5.77) groups. We applied machine learning multivariate single-trial classification to the electroencephalography (EEG) data collected during reward anticipation. The LA group demonstrated significant valence discrimination in the early stages of reward anticipation within the cue-P3 time window (400-550 ms), whereas the HA group was insensitive to valence within this time window. Notably, the LA, but not the HA group demonstrated a relationship between single-trial variability in the early valence component and reaction times for gain and loss trials. This study evidences disrupted hypoactive valence sensitivity in the HA group, revealing potential neurophysiological markers for risky drinking behaviours which place individuals at-risk of adverse health events.


Assuntos
Alcoolismo , Consumo de Bebidas Alcoólicas , Sinais (Psicologia) , Etanol , Humanos , Motivação , Recompensa
3.
Environ Microbiol ; 22(6): 2124-2139, 2020 06.
Artigo em Inglês | MEDLINE | ID: mdl-32124508

RESUMO

The balance between nitrate respiration pathways, denitrification and dissimilatory nitrate (NO3 - ) reduction to ammonium (DNRA), determines whether bioavailable nitrogen is removed as N2 gas or recycled as ammonium. Saltwater intrusion and organic matter enrichment may increase sulphate reduction leading to sulphide accumulation. We investigated the effects of sulphide on the partitioning of NO3 - between complete denitrification and DNRA and the microbial communities in salt marsh sediments. Complete denitrification significantly decreased with increasing sulphide, resulting in an increase in the contribution of DNRA to NO3 - respiration. Alternative fates of NO3 - became increasingly important at higher sulphide treatments, which could include N2 O production and/or transport into intracellular vacuoles. Higher 16S transcript diversity was observed in the high sulphide treatment, with clear shifts in composition. Generally, low and no sulphide, coupled with high NO3 - , favoured the activity of Campylobacterales, Oceanospirillales and Altermonadales, all of which include opportunistic denitrifiers. High ∑sulphide conditions promoted the activity of potential sulphide oxidizing nitrate reducers (Desulfobulbaceae, Acidiferrobacteraceae and Xanthomonadales) and sulphate reducers (Desulfomonadaceae, Desulfobacteraceae). Our study highlights the tight coupling between N and S cycling, and the implications of these dynamics on the fate of bioavailable N in coastal environments susceptible to intermittent saltwater inundation and organic matter enrichment.


Assuntos
Compostos de Amônio/metabolismo , Desnitrificação/fisiologia , Gammaproteobacteria/metabolismo , Sedimentos Geológicos/microbiologia , Sulfetos/farmacologia , Sedimentos Geológicos/química , Microbiota , Nitratos/metabolismo , Nitrogênio/metabolismo , Áreas Alagadas
4.
Bioscience ; 70(12): 1108-1119, 2020 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-33376455

RESUMO

Excess reactive nitrogen (N) flows from agricultural, suburban, and urban systems to coasts, where it causes eutrophication. Coastal wetlands take up some of this N, thereby ameliorating the impacts on nearshore waters. Although the consequences of N on coastal wetlands have been extensively studied, the effect of the specific form of N is not often considered. Both oxidized N forms (nitrate, NO3-) and reduced forms (ammonium, NH4+) can relieve nutrient limitation and increase primary production. However, unlike NH4+, NO3- can also be used as an electron acceptor for microbial respiration. We present results demonstrating that, in salt marshes, microbes use NO3- to support organic matter decomposition and primary production is less stimulated than when enriched with reduced N. Understanding how different forms of N mediate the balance between primary production and decomposition is essential for managing coastal wetlands as N enrichment and sea level rise continue to assail our coasts.

5.
J Fish Biol ; 97(5): 1354-1362, 2020 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-32789856

RESUMO

Atlantic sturgeon are anadromous fish that spend much of their life in near-shore environments. They are designated as "threatened" by the Committee on the Status of Endangered Wildlife in Canada and listed by the IUCN as "near threatened." In Canada, Atlantic sturgeon support small commercial fisheries in the Saint John River, New Brunswick, and the St. Lawrence River, Quebec. While occupying the marine environment, the species is susceptible to various anthropogenic stressors, including by-catch in trawl fisheries and through interactions with coastal engineering projects such as tidal power development. Atlantic sturgeon are also susceptible to implantation of acoustic tags used by researchers to study their movement ecology. These stressors can cause physiological and behavioural changes in the fish that can negatively impact their viability. Because the species are commercially important, and are also of conservation concern, it is important to understand stress responses of Atlantic sturgeon to better mitigate the effects of increased industrial activity in the coastal zone. This study used proteomics to identify and characterize protease activity and identify putative novel protein biomarkers in the epidermal mucus of Atlantic sturgeon. Changes in protein profiles in Atlantic sturgeon epidermal mucus as a result of by-catch and surgery stress were investigated using one-dimensional sodium dodecyl sulphate-polyacrylamide gel electrophoresis and mass spectrometry. Proteolytic activity was identified and characterized using inhibition zymography, which provided information on the classes of proteases that are associated with stress. Samples were collected from Atlantic sturgeon on the Minas Basin, Nova Scotia, Canada, after capture by brush weir and otter trawl, and after surgical implantation of a V16-69 kHz VEMCO acoustic tag. Significant proteins found in the epidermal mucus include various inflammatory proteins, with calmodulin and complement 9 found ubiquitously, and more rarely lysosome C, identified in a brush weir capture sample. Serum albumin, a blood plasma protein, was another ubiquitous protein and verifies how the sample collection method provides a picture of the internal systems. Protease activity was dominantly exhibited by matrix metalloproteases and serine proteases in all sample collections, with serine proteases more active in otter trawl captures than in brush weir captures. By identifying potential protein biomarkers of stress, this study is an example of a non-invasive method for measuring stress in Atlantic sturgeon. Understanding the defence mechanism and release of non-specific biomarkers can be used to improve conservation regulations, as well as to contribute to the limited scientific knowledge on the stress response of Atlantic sturgeon.


Assuntos
Biomarcadores/metabolismo , Epiderme/enzimologia , Peixes/fisiologia , Muco/enzimologia , Peptídeo Hidrolases/metabolismo , Estresse Fisiológico/fisiologia , Animais , Canadá , Proteínas de Peixes/metabolismo , Pesqueiros , Novo Brunswick , Nova Escócia , Rios
6.
Eur J Neurosci ; 50(3): 2311-2321, 2019 08.
Artigo em Inglês | MEDLINE | ID: mdl-30402987

RESUMO

Identifying key neural substrates in addiction disorders for targeted drug development remains a major challenge for clinical neuroscience. One emerging target is the opioid system, where substance-dependent populations demonstrate prefrontal opioid dysregulation that predicts impulsivity and relapse. This may suggest that disturbances to the prefrontal opioid system could confer a risk for relapse in addiction due to weakened 'top-down' control over impulsive behaviour. Naltrexone is currently licensed for alcohol dependence and is also used clinically for impulse control disorders. Using a go/no-go (GNG) task, we examined the effects of acute naltrexone on the neural correlates of successful motor impulse control in abstinent alcoholics (AUD), abstinent polysubstance-dependent (poly-SUD) individuals and controls during a randomised double blind placebo controlled fMRI study. In the absence of any differences on GNG task performance, the AUD group showed a significantly greater BOLD response compared to the control group in lateral and medial prefrontal regions during both placebo and naltrexone treatments; effects that were positively correlated with alcohol abstinence. There was also a dissociation in the positive modulating effects of naltrexone in the orbitofrontal cortex (OFC) and anterior insula cortex (AIC) of the AUD and poly-SUD groups respectively. Self-reported trait impulsivity in the poly-SUD group also predicted the effect of naltrexone in the AIC. These results suggest that acute naltrexone differentially amplifies neural responses within two distinct regions of a salience network during successful motor impulse control in abstinent AUD and poly-SUD groups, which are predicted by trait impulsivity in the poly-SUD group.


Assuntos
Abstinência de Álcool , Dissuasores de Álcool/uso terapêutico , Alcoolismo/diagnóstico por imagem , Comportamento Impulsivo/fisiologia , Naltrexona/uso terapêutico , Desempenho Psicomotor/fisiologia , Adulto , Dissuasores de Álcool/farmacologia , Alcoolismo/tratamento farmacológico , Método Duplo-Cego , Feminino , Humanos , Comportamento Impulsivo/efeitos dos fármacos , Imageamento por Ressonância Magnética/métodos , Masculino , Pessoa de Meia-Idade , Naltrexona/farmacologia , Desempenho Psicomotor/efeitos dos fármacos , Transtornos Relacionados ao Uso de Substâncias/diagnóstico por imagem , Transtornos Relacionados ao Uso de Substâncias/tratamento farmacológico , Adulto Jovem
7.
Glob Chang Biol ; 25(10): 3224-3241, 2019 10.
Artigo em Inglês | MEDLINE | ID: mdl-31317634

RESUMO

Salt marshes sequester carbon at rates more than an order of magnitude greater than their terrestrial counterparts, helping to mitigate climate change. As nitrogen loading to coastal waters continues, primarily in the form of nitrate, it is unclear what effect it will have on carbon storage capacity of these highly productive systems. This uncertainty is largely driven by the dual role nitrate can play in biological processes, where it can serve as a nutrient-stimulating primary production or a thermodynamically favorable electron acceptor fueling heterotrophic metabolism. Here, we used a controlled flow-through reactor experiment to test the role of nitrate as an electron acceptor, and its effect on organic matter decomposition and the associated microbial community in salt marsh sediments. Organic matter decomposition significantly increased in response to nitrate, even at sediment depths typically considered resistant to decomposition. The use of isotope tracers suggests that this pattern was largely driven by stimulated denitrification. Nitrate addition also significantly altered the microbial community and decreased alpha diversity, selecting for taxa belonging to groups known to reduce nitrate and oxidize more complex forms of organic matter. Fourier Transform-Infrared Spectroscopy further supported these results, suggesting that nitrate facilitated decomposition of complex organic matter compounds into more bioavailable forms. Taken together, these results suggest the existence of organic matter pools that only become accessible with nitrate and would otherwise remain stabilized in the sediment. The existence of such pools could have important implications for carbon storage, since greater decomposition rates as N loading increases may result in less overall burial of organic-rich sediment. Given the extent of nitrogen loading along our coastlines, it is imperative that we better understand the resilience of salt marsh systems to nutrient enrichment, especially if we hope to rely on salt marshes, and other blue carbon systems, for long-term carbon storage.


Assuntos
Nitratos , Áreas Alagadas , Carbono , Desnitrificação , Nitrogênio
8.
Microb Ecol ; 77(2): 343-357, 2019 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-30612185

RESUMO

Bivalves serve an important ecosystem function in delivering organic matter from pelagic to benthic zones and are important in mediating eutrophication. However, the fate of this organic matter (i.e., biodeposits) is an important consideration when assessing the ecological roles of these organisms in coastal ecosystems. In addition to environmental conditions, the processing of biodeposits is dependent on its composition and the metabolic capacity of the associated microbial community. The objectives of this study were to compare the biological reactivity, potential denitrification rates, and microbial communities of biodeposits sourced from different bivalve species: hard clam (Mercenaria mercenaria), eastern oyster (Crassostrea virginica), and ribbed mussel (Geukensia demissa). To our knowledge, this is the first study to investigate and compare the microbiome of bivalve biodeposits using high-throughput sequencing and provide important insight into the mechanisms by which bivalves may alter sediment microbial communities and benthic biogeochemical cycles. We show that clam biodeposits had significantly higher bioreactivity compared to mussel and oyster biodeposits, as reflected in higher dissolved inorganic carbon and ammonium production rates in controlled incubations. Potential denitrification rates were also significantly higher for clam biodeposits compared to oyster and mussel biodeposits. The microbial communities associated with the biodeposits were significantly different across bivalve species, with significantly greater abundances of Alteromonadales, Chitinophagales, Rhodobacterales, and Thiotrichales associated with the clam biodeposits. These bioreactivity and microbial differences across bivalve species are likely due to differences in bivalve physiology and feeding behavior and should be considered when evaluating the effects of bivalves on water quality and ecosystem function.


Assuntos
Bactérias/isolamento & purificação , Bivalves/microbiologia , Microbiota , Compostos de Amônio/metabolismo , Animais , Bactérias/classificação , Bactérias/genética , Bactérias/metabolismo , Bivalves/metabolismo , Carbono/metabolismo , Crassostrea/metabolismo , Crassostrea/microbiologia , Eutrofização , Sedimentos Geológicos/química , Sedimentos Geológicos/microbiologia , Mercenaria/metabolismo , Mercenaria/microbiologia , Filogenia , Água do Mar/química , Água do Mar/microbiologia
9.
Respirology ; 24(8): 752-757, 2019 08.
Artigo em Inglês | MEDLINE | ID: mdl-30887627

RESUMO

BACKGROUND AND OBJECTIVE: We investigated the repeatability and validity of the incremental shuttle walk test (ISWT) distance compared to peak oxygen uptake (VO2pk ) during maximal incremental cycle ergometer (ICE) and treadmill (ITM) tests in adults with severe asthma. METHODS: Adults with severe asthma, Medical Research Council (MRC) dyspnoea ≥2, were recruited from specialists caring for patients with severe asthma. All participants performed three ISWT (familiarization and two subsequent tests on the same day), an ICE and an ITM in a randomized order, on separate days, to intolerance with expiratory gas analysis. RESULTS: A total of 50 patients (32 females, mean (SD), age: 54 (13) years, forced expiratory volume in 1 s (FEV1 ): 1.9 (0.8) L and body mass index (BMI): 32 (6) kg/m2 ) completed all five tests. The mean (SD) ISWT distance for each test was 400 (156), 418 (142) and 438 (157) m (P = 0.001), respectively. There was a strong correlation between the ISWT distance with VO2pk derived from ITM (r = 0.74, P < 0.001) and ICE (r = 0.75, P < 0.001). CONCLUSION: There was a small increase in the mean ISWT distance on sequential testing. In clinical practice, the coefficient of repeatability and heteroscedasticity need to be considered when assessing whether a true change has occurred within an individual patient. The ISWT has validity compared to VO2pk on both ICE and ITM, but they are not interchangeable.


Assuntos
Asma , Tolerância ao Exercício , Consumo de Oxigênio/fisiologia , Teste de Caminhada/métodos , Asma/diagnóstico , Asma/fisiopatologia , Precisão da Medição Dimensional , Ergometria/métodos , Feminino , Volume Expiratório Forçado , Humanos , Masculino , Pessoa de Meia-Idade , Esforço Físico , Reprodutibilidade dos Testes , Índice de Gravidade de Doença
10.
Behav Sleep Med ; 17(5): 646-656, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-29528702

RESUMO

OBJECTIVES/BACKGROUND: A high proportion of children with Attention Deficit Hyperactivity Disorder- Combined type (ADHD-CT) experience sleep and motor problems. This study investigated (a) whether motor proficiency moderated the relationship between ADHD symptoms and sleep problems in children with and without ADHD-CT and (b) whether this moderation differed as a function of ADHD diagnosis. PARTICIPANTS: A sample of 70 primary school male children between 8-15 years were recruited; children with ADHD-CT (n = 38; mean age 10 years, 2 months [SD = 1 year, 6 months]) and a typically developing (TD) (n = 32; mean age 9 years, 6 months [SD = 1 year, 5 months]) group. METHODS: Motor proficiency was measured using the Movement Assessment Battery for Children-2nd Edition (MABC-2), ADHD symptoms were measured using the Conners' Parent Rating Scale (CPRS) and parent reported sleep problems were measured using the Children's Sleep Habits Questionnaire (CSHQ). RESULTS: Children who reported higher ADHD symptoms and lower motor proficiency scores reported more sleep problems. The moderation effect only held in children with a diagnosis of ADHD-CT and not in the typically developing group. CONCLUSIONS: These findings indicate that children who experience greater severity of ADHD symptoms who also have lower motor proficiency may be at increased risk of experiencing sleep problems. These findings also illustrate the importance of considering motor proficiency when exploring risk factors for sleep problems in children with ADHD-CT as well as sleep interventions.


Assuntos
Transtorno do Deficit de Atenção com Hiperatividade/complicações , Transtornos do Sono-Vigília/etiologia , Sono/fisiologia , Adolescente , Transtorno do Deficit de Atenção com Hiperatividade/fisiopatologia , Criança , Comorbidade , Feminino , Humanos , Masculino , Transtornos do Sono-Vigília/epidemiologia , Inquéritos e Questionários
11.
Addict Biol ; 23(5): 1168-1178, 2018 09.
Artigo em Inglês | MEDLINE | ID: mdl-28940758

RESUMO

Relapse after initially successful treatment is a significant problem facing the treatment of opioid dependence. Evidence suggests craving elicited by re-exposure to drug cues may precipitate relapse. Attempts to identify neural biomarkers of cue-elicited craving have yielded inconsistent findings. We aimed to apply a novel continuous functional magnetic resonance imaging technique to follow the minute-to-minute evolution of brain responses, which correlate with the waxing and waning of craving. Newly detoxified male opioid-dependent patients and healthy control participants attended two separate, counterbalanced, functional magnetic resonance imaging scanning sessions during which they viewed a 10-minute video (drug cue or neutral cue) followed by 5 minutes of fixation. Participants rated the intensity of their craving throughout each session. We hypothesized that subcortical/ventral prefrontal cortex (PFC) regions and dorsal PFC regions would show different associations with craving reflecting their putative roles in appetitive processing versus cognitive control. Compared with controls, drug cue (minus neutral cue) video recruited the left amygdala and was temporally correlated with craving. In contrast, dorsal anterior cingulate blood-oxygen-level-dependent signal time course was higher than controls only during a period after cue exposure when craving levels were declining. Against expectations, neither the ventral striatum nor ventral PFC was significantly recruited by drug cue exposure. Findings suggest that the amygdala has a central role in craving, whereas the dorsal anterior cingulate may control craving in treatment-seeking patients. Time course analysis yielded new insights into the neural substrates of craving that could objectively validate development of psychological and pharmacological approaches to sustained abstinence.


Assuntos
Encéfalo/diagnóstico por imagem , Encéfalo/fisiopatologia , Fissura/efeitos dos fármacos , Fissura/fisiologia , Transtornos Relacionados ao Uso de Opioides/fisiopatologia , Adulto , Mapeamento Encefálico/métodos , Sinais (Psicologia) , Feminino , Humanos , Imageamento por Ressonância Magnética/métodos , Masculino , Vias Neurais/diagnóstico por imagem , Vias Neurais/efeitos dos fármacos , Vias Neurais/fisiopatologia , Recidiva
12.
Addict Biol ; 23(1): 425-436, 2018 01.
Artigo em Inglês | MEDLINE | ID: mdl-28247526

RESUMO

Naltrexone, an opioid receptor antagonist, is commonly used as a relapse prevention medication in alcohol and opiate addiction, but its efficacy and the mechanisms underpinning its clinical usefulness are not well characterized. In the current study, we examined the effects of 50-mg naltrexone compared with placebo on neural network changes associated with substance dependence in 21 alcohol and 36 poly-drug-dependent individuals compared with 36 healthy volunteers. Graph theoretic and network-based statistical analysis of resting-state functional magnetic resonance imaging (MRI) data revealed that alcohol-dependent subjects had reduced functional connectivity of a dispersed network compared with both poly-drug-dependent and healthy subjects. Higher local efficiency was observed in both patient groups, indicating clustered and segregated network topology and information processing. Naltrexone normalized heightened local efficiency of the neural network in alcohol-dependent individuals, to the same levels as healthy volunteers. Naltrexone failed to have an effect on the local efficiency in abstinent poly-substance-dependent individuals. Across groups, local efficiency was associated with substance, but no alcohol exposure implicating local efficiency as a potential premorbid risk factor in alcohol use disorders that can be ameliorated by naltrexone. These findings suggest one possible mechanism for the clinical effects of naltrexone, namely, the amelioration of disrupted network topology.


Assuntos
Dissuasores de Álcool/farmacologia , Alcoolismo/diagnóstico por imagem , Encéfalo/efeitos dos fármacos , Naltrexona/farmacologia , Adulto , Alcoolismo/fisiopatologia , Encéfalo/diagnóstico por imagem , Encéfalo/fisiopatologia , Feminino , Neuroimagem Funcional , Voluntários Saudáveis , Humanos , Imageamento por Ressonância Magnética , Masculino , Pessoa de Meia-Idade , Vias Neurais , Transtornos Relacionados ao Uso de Substâncias/diagnóstico por imagem , Transtornos Relacionados ao Uso de Substâncias/fisiopatologia , Adulto Jovem
13.
Clin Rehabil ; 32(5): 630-643, 2018 May.
Artigo em Inglês | MEDLINE | ID: mdl-29072092

RESUMO

OBJECTIVE: To determine the effectiveness of a six-week rehabilitation programme followed by a home exercise programme for Friedreich's ataxia. DESIGN: Randomized, delayed-start control single-blind trial. SETTING: Outpatient rehabilitation centre. SUBJECTS: Ambulant or non-ambulant individuals with Friedreich's ataxia. INTERVENTION: Participants were randomized to a six-week outpatient rehabilitation programme, immediately (intervention group) or after a six-week delayed-start (control group). The rehabilitation was followed by a six-week home exercise programme. MAIN MEASURES: The primary outcome was the Functional Independence Measure. Other measures included the Friedreich Ataxia Impact Scale and the Friedreich Ataxia Rating Scale. Outcomes were administered at baseline, 6, 12 and 18 weeks. RESULTS: Of 159 individuals screened, 92 were excluded and 48 declined to participate. A total of 19 participants were enrolled in the study. There was no significant difference in Functional Independence Measure change from baseline to six weeks in the intervention group (mean ± standard deviation, 2.00 ± 3.16) as compared to the control group (0.56 ± 4.06). Change in the Friedreich Ataxia Impact Scale body movement subscale indicated a significant improvement in health and well-being in the intervention group compared to the control group ( P = 0.003). Significant within-group improvements in the Friedreich Ataxia Impact Scale and the motor domain of the Functional Independence Measure post-rehabilitation were not sustained post-home exercise programme. CONCLUSION: Our study indicates that rehabilitation can improve health and well-being in individuals with Friedreich's ataxia; however, a larger study is required to have sufficient power to detect a significant change in the most sensitive measure of function, the motor domain of the Functional Independence Measure.


Assuntos
Avaliação da Deficiência , Terapia por Exercício , Ataxia de Friedreich/reabilitação , Adulto , Assistência Ambulatorial , Feminino , Humanos , Masculino , Método Simples-Cego , Tempo para o Tratamento
14.
Solid State Nucl Magn Reson ; 89: 21-26, 2018 02.
Artigo em Inglês | MEDLINE | ID: mdl-29277314

RESUMO

Many oil paintings, dating from the 15th century to the present, are affected by the formation of heavy-metal carboxylates (soaps) that alter the structural integrity and appearance of the works. Through transport phenomena not yet understood, free fatty acids formed from oils used as binders migrate through the paint film and react with heavy-metal ions that are constituents of pigments and/or driers, forming metal carboxylates. The local molecular dynamics of fatty acids and metal carboxylates are factors influencing material transport in these systems. We report temperature-dependent 2H NMR spectra of palmitic acid and lead palmitate as pure materials, in cross-linked linseed oil films, and in a lead white linseed oil paint film as part of our broader research into metal soap formation. Local dynamics at the α carbon, at the terminal methyl group, and at the middle of the fatty acid chain were observed in specifically deuterated materials. Changes in the dynamic behavior with temperature were observed by the appearance of two species, a solid-like material and a liquid-like material. The relative amounts of the two phases and their deuterium NMR parameters indicate that the amount of liquid-like material and the local dynamics at that site increase with temperature. At the three locations along the chain and at all temperatures, there is a larger percentage of acyl chains of both palmitic acid and lead palmitate that are "mobile" or liquid-like in linseed oil films than there are in the pure materials. However, the percentage of liquid-like species is decreased in a lead white paint film, as compared to a linseed oil matrix. In addition, these experiments indicate that there is a larger percentage of liquid-like acyl chains of palmitic acid than of lead palmitate under identical conditions in these model paint systems.

15.
Cerebellum ; 16(1): 168-177, 2017 02.
Artigo em Inglês | MEDLINE | ID: mdl-27189071

RESUMO

The cerebellum appears to play a key role in the development of internal rules that allow fast, predictive adjustments to novel stimuli. This is crucial for adaptive motor processes, such as those involved in walking, where cerebellar dysfunction has been found to increase variability in gait parameters. Motor adaptation is a process that results in a progressive reduction in errors as movements are adjusted to meet demands, and within the cerebellum, this seems to be localised primarily within the right hemisphere. To examine the role of the right cerebellar hemisphere in adaptive gait, cathodal transcranial direct current stimulation (tDCS) was administered to the right cerebellar hemisphere of 14 healthy adults in a randomised, double-blind, crossover study. Adaptation to a series of distinct spatial and temporal templates was assessed across tDCS condition via a pressure-sensitive gait mat (ProtoKinetics Zeno walkway), on which participants walked with an induced 'limp' at a non-preferred pace. Variability was assessed across key spatial-temporal gait parameters. It was hypothesised that cathodal tDCS to the right cerebellar hemisphere would disrupt adaptation to the templates, reflected in a failure to reduce variability following stimulation. In partial support, adaptation was disrupted following tDCS on one of the four spatial-temporal templates used. However, there was no evidence for general effects on either the spatial or temporal domain. This suggests, under specific conditions, a coupling of spatial and temporal processing in the right cerebellar hemisphere and highlights the potential importance of task complexity in cerebellar function.


Assuntos
Adaptação Fisiológica/fisiologia , Cerebelo/fisiologia , Estimulação Transcraniana por Corrente Contínua , Caminhada/fisiologia , Adulto , Análise de Variância , Atenção , Fenômenos Biomecânicos , Cognição/fisiologia , Estudos Cross-Over , Método Duplo-Cego , Fadiga/etiologia , Feminino , Lateralidade Funcional , Humanos , Masculino , Testes Neuropsicológicos , Dor/etiologia , Medição da Dor , Tempo de Reação , Estimulação Transcraniana por Corrente Contínua/efeitos adversos , Estimulação Transcraniana por Corrente Contínua/métodos , Adulto Jovem
16.
Addict Biol ; 22(6): 1576-1589, 2017 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-27600363

RESUMO

There is a concerted research effort to investigate brain mechanisms underlying addiction processes that may predicate the development of new compounds for treating addiction. One target is the brain's opioid system, because of its role in the reinforcing effects of substances of abuse. Substance-dependent populations have increased numbers of the mu opioid receptor (MOR) in fronto-striatal regions that predict drug relapse, and demonstrate disturbances in these regions during the processing of non-drug rewards. Naltrexone is currently licensed for alcohol and opiate dependence, and may remediate such disturbances through the blockade of MORs in fronto-striatal reward circuitry. Therefore, we examined the potential acute modulating effects of naltrexone on the anticipation of, and instrumental responding for, non-drug rewards in long-term abstinent alcoholics, alcoholic poly substance-dependent individuals and controls using a monetary incentive delay (MID) task during a randomized double blind placebo controlled functional MRI study. We report that the alcoholic poly substance-dependent group exhibited slower and less accurate instrumental responding compared to alcoholics and controls that was less evident after acute naltrexone treatment. However, naltrexone treatment was unable to remediate disturbances within fronto-striatal regions during reward anticipation and 'missed' rewards in either substance-dependent group. While we have not been able to identify the underlying neural mechanisms for improvement observed with naltrexone in the alcoholic poly-substance dependent group, we can confirm that both substance-dependent groups exhibit substantial neural deficits during an MID task, despite being in long-term abstinence.


Assuntos
Alcoolismo/fisiopatologia , Corpo Estriado/efeitos dos fármacos , Corpo Estriado/fisiopatologia , Desvalorização pelo Atraso/fisiologia , Naltrexona/farmacologia , Antagonistas de Entorpecentes/farmacologia , Adulto , Método Duplo-Cego , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Motivação , Recompensa , Transtornos Relacionados ao Uso de Substâncias/fisiopatologia , Reino Unido
19.
Am J Physiol Heart Circ Physiol ; 309(3): H407-20, 2015 Aug 01.
Artigo em Inglês | MEDLINE | ID: mdl-26055789

RESUMO

We aimed to determine if chronic endurance-exercise habits affected redox status and paracrine function of CD34(+) and CD34(-)/CD31(+) circulating angiogenic cells (CACs). Subjects were healthy, nonsmoking men and women aged 18-35 yr and categorized by chronic physical activity habits. Blood was drawn from each subject for isolation and culture of CD34(+) and CD34(-)/CD31(+) CACs. No differences in redox status were found in any group across either cell type. Conditioned media (CM) was generated from the cultured CACs and used in an in vitro human umbilical vein endothelial cell-based tube assay. CM from CD34(+) cells from inactive individuals resulted in tube structures that were 29% shorter in length (P < 0.05) and 45% less complex (P < 0.05) than the endurance-trained group. CD34(-)/CD31(+) CM from inactive subjects resulted in tube structures that were 26% shorter in length (P < 0.05) and 42% less complex (P < 0.05) than endurance-trained individuals. Proteomics analyses identified S100A8 and S100A9 in the CM. S100A9 levels were 103% higher (P < 0.05) and S100A8 was 97% higher in the CD34(-)/CD31(+) CM of inactive subjects compared with their endurance-trained counterparts with no significant differences in either protein in the CM of CD34(+) CACs as a function of training status. Recombinant S100A8/A9 treatment at concentrations detected in inactive subjects' CD34(-)/CD31(+) CAC CM also reduced tube formation (P < 0.05). These findings are the first, to our knowledge, to demonstrate a differential paracrine role in CD34(+) and CD34(-)/CD31(+) CACs on tube formation as a function of chronic physical activity habits and identifies a differential secretion of S100A9 by CD34(-)/CD31(+) CACs due to habitual exercise.


Assuntos
Antígenos CD34/metabolismo , Células Progenitoras Endoteliais/metabolismo , Exercício Físico , Neovascularização Fisiológica , Comunicação Parácrina , Molécula-1 de Adesão Celular Endotelial a Plaquetas/metabolismo , Adolescente , Adulto , Antígenos CD34/genética , Estudos de Casos e Controles , Células Cultivadas , Células Progenitoras Endoteliais/citologia , Feminino , Humanos , Masculino , Molécula-1 de Adesão Celular Endotelial a Plaquetas/genética , Proteínas S100/genética , Proteínas S100/metabolismo
20.
Clin Rehabil ; 29(9): 907-19, 2015 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-25413169

RESUMO

OBJECTIVE: To investigate the safety, feasibility and potential efficacy of balance training in adults with cerebral palsy. DESIGN: Phase 2, assessor-blinded randomized controlled trial. SETTING: Outpatient rehabilitation facility. SUBJECTS: A total of 17 ambulatory adults with cerebral palsy. INTERVENTIONS: Participants were randomly allocated to an eight-week, once-weekly, small group programme of balance training, or seated attention control activity. Balance training was individually tailored using the Balance Evaluation Systems test. MAIN MEASURES: Primary focus was feasibility, addressed by recruitment, retention, adherence, and safety. Efficacy was primarily evaluated with the Ambulatory Self-Confidence Questionnaire and the Balance Evaluation Systems test, at intervention conclusion and Week 24. Secondary outcomes included gait speed, walking distance, falls efficacy, fatigue, quality of life, and global impression of change. RESULTS: Interventions were safe and feasible with no major adverse events. Adherence was high. At eight and 24 weeks, there were negligible between-group differences in Balance Evaluation systems test total. At 24 weeks, there was a small, non-significant between-group difference in favour of the balance group with effect sizes of 0.14 for ambulatory self-confidence, 0.10 for falls efficacy, and 0.12 for fatigue. There were significant between-group differences for self-reported walking confidence and balance change, in favour of the balance group at Weeks 8 and 24 (p < 0.05). CONCLUSION: A customised balance programme is feasible and safe for ambulant adults with cerebral palsy. Small effects from balance training in selected outcomes occurred. Study replication with at least 38 participants per group to confirm efficacy is warranted.


Assuntos
Paralisia Cerebral/reabilitação , Equilíbrio Postural/fisiologia , Adulto , Paralisia Cerebral/complicações , Paralisia Cerebral/fisiopatologia , Estudos de Viabilidade , Feminino , Marcha/fisiologia , Humanos , Masculino , Cooperação do Paciente , Projetos Piloto , Qualidade de Vida , Método Simples-Cego , Resultado do Tratamento
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