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1.
Chem Rev ; 123(13): 8530-8574, 2023 07 12.
Artigo em Inglês | MEDLINE | ID: mdl-37342028

RESUMO

Anionic species are omnipresent and involved in many important biological processes. A large number of artificial anion receptors has therefore been developed. Some of these are capable of mediating transmembrane transport. However, where transport proteins can respond to stimuli in their surroundings, creation of synthetic receptors with stimuli-responsive functions poses a major challenge. Herein, we give a full overview of the stimulus-controlled anion receptors that have been developed thus far, including their application in membrane transport. In addition to their potential operation as membrane carriers, the use of anion recognition motifs in forming responsive membrane-spanning channels is discussed. With this review article, we intend to increase interest in transmembrane transport among scientists working on host-guest complexes and dynamic functional systems in order to stimulate further developments.


Assuntos
Receptores Artificiais , Transporte Biológico , Ânions/química
2.
J Neurosci ; 43(15): 2730-2740, 2023 04 12.
Artigo em Inglês | MEDLINE | ID: mdl-36868858

RESUMO

Behavioral reports of sensory information are biased by stimulus history. The nature and direction of such serial-dependence biases can differ between experimental settings; both attractive and repulsive biases toward previous stimuli have been observed. How and when these biases arise in the human brain remains largely unexplored. They could occur either via a change in sensory processing itself and/or during postperceptual processes such as maintenance or decision-making. To address this, we tested 20 participants (11 female) and analyzed behavioral and magnetoencephalographic (MEG) data from a working-memory task in which participants were sequentially presented with two randomly oriented gratings, one of which was cued for recall at the end of the trial. Behavioral responses showed evidence for two distinct biases: (1) a within-trial repulsive bias away from the previously encoded orientation on the same trial, and (2) a between-trial attractive bias toward the task-relevant orientation on the previous trial. Multivariate classification of stimulus orientation revealed that neural representations during stimulus encoding were biased away from the previous grating orientation, regardless of whether we considered the within-trial or between-trial prior orientation, despite opposite effects on behavior. These results suggest that repulsive biases occur at the level of sensory processing and can be overridden at postperceptual stages to result in attractive biases in behavior.SIGNIFICANCE STATEMENT Recent experience biases behavioral reports of sensory information, possibly capitalizing on the temporal regularity in our environment. It is still unclear at what stage of stimulus processing such serial biases arise. Here, we recorded behavior and neurophysiological [magnetoencephalographic (MEG)] data to test whether neural activity patterns during early sensory processing show the same biases seen in participants' reports. In a working-memory task that produced multiple biases in behavior, responses were biased toward previous targets, but away from more recent stimuli. Neural activity patterns were uniformly biased away from all previously relevant items. Our results contradict proposals that all serial biases arise at an early sensory processing stage. Instead, neural activity exhibited mostly adaptation-like responses to recent stimuli.


Assuntos
Memória de Curto Prazo , Percepção Visual , Humanos , Feminino , Percepção Visual/fisiologia , Memória de Curto Prazo/fisiologia , Cognição , Encéfalo , Sinais (Psicologia)
3.
J Org Chem ; 88(15): 11328-11334, 2023 Aug 04.
Artigo em Inglês | MEDLINE | ID: mdl-37440304

RESUMO

Toward photocontrol of anion transport across the bilayer membrane, stiff-stilbene, which has dimethyl substituents in the five-membered rings, is functionalized with amidopyrrole units. UV-vis and 1H NMR studies show high photostability and photoconversion yields. Where the photoaddressable (E)- and (Z)-isomers exhibit comparable binding affinities, as determined by 1H NMR titrations, fluorescence-based transport assays reveal significantly higher transport activity for the (Z)-isomers. Changing the binding affinity is thus not a necessity for modulating transport. Additionally, transport can be triggered in situ by light.

4.
J Am Chem Soc ; 144(1): 331-338, 2022 01 12.
Artigo em Inglês | MEDLINE | ID: mdl-34932344

RESUMO

Membrane transport proteins fulfill important regulatory functions in biology with a common trait being their ability to respond to stimuli in the environment. Various small-molecule receptors, capable of mediating transmembrane transport, have been successfully developed. However, to confer stimuli-responsiveness on them poses a fundamental challenge. Here we demonstrate photocontrol of transmembrane transport and electric potential using bis(thio)ureas derived from stiff-stilbene. UV-vis and 1H NMR spectroscopy are used to monitor E-Z photoisomerization of these bis(thio)ureas and 1H NMR titrations reveal stronger binding of chloride to the (Z)-form than to the (E)-form. Additional insight into the binding properties is provided by single crystal X-ray crystallographic analysis and DFT geometry optimization. Importantly, the (Z)-isomers are much more active in transmembrane transport than the respective (E)-isomers as shown through various assays. As a result, both membrane transport and depolarization can be modulated upon irradiation, opening up new prospects toward light-based therapeutics as well as physiological and optopharmacological tools for studying anion transport-associated diseases and to stimulate neuronal activity, respectively.


Assuntos
Ureia
5.
J Neurogenet ; 36(2-3): 81-87, 2022.
Artigo em Inglês | MEDLINE | ID: mdl-36226509

RESUMO

Lesch-Nyhan disease (LND) is a neurodevelopmental disorder caused by variants in the HPRT1 gene, which encodes the enzyme hypoxanthine-guanine phosphoribosyl transferase (HGprt). HGprt deficiency provokes numerous metabolic changes which vary among different cell types, making it unclear which changes are most relevant for abnormal neural development. To begin to elucidate the consequences of HGprt deficiency for developing human neurons, neural stem cells (NSCs) were prepared from 6 induced pluripotent stem cell (iPSC) lines from individuals with LND and compared to 6 normal healthy controls. For all 12 lines, gene expression profiles were determined by RNA-seq and protein expression profiles were determined by shotgun proteomics. The LND lines revealed significant changes in expression of multiple genes and proteins. There was little overlap in findings between iPSCs and NSCs, confirming the impact of HGprt deficiency depends on cell type. For NSCs, gene expression studies pointed towards abnormalities in WNT signaling, which is known to play a role in neural development. Protein expression studies pointed to abnormalities in the mitochondrial F0F1 ATPase, which plays a role in maintaining cellular energy. These studies point to some mechanisms that may be responsible for abnormal neural development in LND.


Assuntos
Síndrome de Lesch-Nyhan , Células-Tronco Neurais , Humanos , Síndrome de Lesch-Nyhan/genética , Síndrome de Lesch-Nyhan/metabolismo , Hipoxantina Fosforribosiltransferase/genética , Hipoxantina Fosforribosiltransferase/metabolismo , Guanina/metabolismo , Adenosina Trifosfatases , Hipoxantinas
6.
Neuroimage ; 237: 118030, 2021 08 15.
Artigo em Inglês | MEDLINE | ID: mdl-33836272

RESUMO

Recent advances have made it possible to decode various aspects of visually presented stimuli from patterns of scalp EEG measurements. As of recently, such multivariate methods have been commonly used to decode visual-spatial features such as location, orientation, or spatial frequency. In the current study, we show that it is also possible to track visual colour processing by using Linear Discriminant Analysis on patterns of EEG activity. Building on other recent demonstrations, we show that colour decoding: (1) reflects sensory qualities (as opposed to, for example, verbal labelling) with a prominent contribution from posterior electrodes contralateral to the stimulus, (2) conforms to a parametric coding space, (3) is possible in multi-item displays, and (4) is comparable in magnitude to the decoding of visual stimulus orientation. Through subsampling our data, we also provide an estimate of the approximate number of trials and participants required for robust decoding. Finally, we show that while colour decoding can be sensitive to subtle differences in luminance, our colour decoding results are primarily driven by measured colour differences between stimuli. Colour decoding opens a relevant new dimension in which to track visual processing using scalp EEG measurements, while bypassing potential confounds associated with decoding approaches that focus on spatial features.


Assuntos
Córtex Cerebral/fisiologia , Percepção de Cores/fisiologia , Eletroencefalografia/métodos , Neuroimagem Funcional/métodos , Reconhecimento Visual de Modelos/fisiologia , Percepção Espacial/fisiologia , Adolescente , Adulto , Sensibilidades de Contraste/fisiologia , Eletroculografia , Feminino , Lateralidade Funcional/fisiologia , Humanos , Masculino , Processamento de Sinais Assistido por Computador , Aprendizado de Máquina Supervisionado , Adulto Jovem
7.
Dev Med Child Neurol ; 63(8): 963-968, 2021 08.
Artigo em Inglês | MEDLINE | ID: mdl-33689173

RESUMO

AIM: To provide insight into outcome and long-term safety and efficacy of deep brain stimulation (DBS), from the perspective of individuals with Lesch-Nyhan disease (LND) and their families. METHOD: We used patient-centered outcome measures to assess long-term outcomes of DBS for 14 individuals (mean [SD] age 10y 10mo [5y 6mo], range 5-23y, all males) with LND, after an average duration of 5y 6mo (range 11mo-10y 5mo) after surgery. We compared these results with a comprehensive review of previously published cases. RESULTS: Patients and their families reported that DBS of the globus pallidus can be effective both for motor and behavioral disturbances in LND. However, outcome measures were often not significantly changed owing to substantial variability among individuals, and were overall less positive than in previous reports based on clinician assessments. In addition, there was an unexpectedly high rate of adverse events, tempering overall enthusiasm for the procedure. INTERPRETATION: Although DBS might be an effective treatment for LND, more research is needed to understand the reasons for response variability and the unusually high rates of adverse events before DBS can be recommended for these patients. What this paper adds Individuals with Lesch-Nyhan disease and their families report variable efficacy of deep brain stimulation. Long-term outcomes are associated with a high adverse event rate.


Assuntos
Estimulação Encefálica Profunda , Globo Pálido/fisiopatologia , Síndrome de Lesch-Nyhan/terapia , Adolescente , Criança , Pré-Escolar , Feminino , Humanos , Síndrome de Lesch-Nyhan/fisiopatologia , Masculino , Avaliação de Resultados da Assistência ao Paciente , Resultado do Tratamento , Adulto Jovem
8.
J Adv Nurs ; 77(4): 1899-1910, 2021 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-33491803

RESUMO

AIMS: To explore inpatient staff's understanding and implementation of positive risk management. BACKGROUND: Risk management is an essential skill for staff working in acute mental health inpatient settings. National policies advocate the use of positive risk management as a form of collaborative, recovery-focused risk management. However, little is known about how staff understand, operationalize, and use positive risk management in practice. DESIGN: Qualitative reflexive thematic analysis study. METHODS: The authors recruited a purposive sample of healthcare professionals working in acute inpatient settings (N = 16) in 2019 across three National Health Service Trusts in the North-West of England. Participants completed semi-structured interviews which were analysed using reflexive thematic analysis. RESULTS: The analysis generated three themes: (a) within staff barriers; (b) within service user barriers; and (c) delivery in practice. CONCLUSION: Understanding and implementation of positive risk management was dependant on multiple factors, including staffs' beliefs about mental health, levels of worry and anxiety, and amount of experience and seniority. Staff were more likely to use positive risk management with service users that they perceived as being trustworthy and less risky. Use of positive risk management was reliant on the support practitioners received, how able they were to view situations from multiple perspectives, and the degree to which they felt able to prioritize positive risk management. IMPACT: Although staff expressed the desire and intention to practice positive risk management, the current study highlights challenges around operationalization and implementation. The authors discuss the clinical implications of the findings.


Assuntos
Pacientes Internados , Saúde Mental , Atitude do Pessoal de Saúde , Inglaterra , Humanos , Pesquisa Qualitativa , Medicina Estatal
9.
Theor Appl Genet ; 133(6): 1859-1871, 2020 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-32043234

RESUMO

KEY MESSAGE: A Genome-Wide Association Study using 330 commercial potato varieties identified haplotype specific SNP markers associated with pathotype 1(D1) wart disease resistance. Synchytrium endobioticum is a soilborne obligate biotrophic fungus responsible for wart disease. Growing resistant varieties is the most effective way to manage the disease. This paper addresses the challenge to apply molecular markers in potato breeding. Although markers linked to Sen1 were published before, the identification of haplotype-specific single-nucleotide polymorphisms may result in marker assays with high diagnostic value. To identify hs-SNP markers, we performed a genome-wide association study (GWAS) in a panel of 330 potato varieties representative of the commercial potato gene pool. SNP markers significantly associated with pathotype 1 resistance were identified on chromosome 11, at the position of the previously identified Sen1 locus. Haplotype specificity of the SNP markers was examined through the analysis of false positives and false negatives and validated in two independent full-sib populations. This paper illustrates why it is not always feasible to design markers without false positives and false negatives for marker-assisted selection. In the case of Sen1, founders could not be traced because of a lack of identity by descent and because of the decay of linkage disequilibrium between Sen1 and flanking SNP markers. Sen1 appeared to be the main source of pathotype 1 resistance in potato varieties, but it does not explain all the resistance observed. Recombination and introgression breeding may have introduced new, albeit rare haplotypes involved in pathotype 1 resistance. The GWAS approach, in such case, is instrumental to identify SNPs with the best possible diagnostic value for marker-assisted breeding.


Assuntos
Resistência à Doença/genética , Doenças das Plantas/genética , Doenças das Plantas/microbiologia , Polimorfismo de Nucleotídeo Único , Solanum tuberosum/genética , Cromossomos de Plantas , Quitridiomicetos/patogenicidade , Genes de Plantas , Estudos de Associação Genética , Marcadores Genéticos , Haplótipos , Desequilíbrio de Ligação , Repetições de Microssatélites , Fenótipo , Locos de Características Quantitativas , Solanum tuberosum/microbiologia
10.
Theor Appl Genet ; 133(12): 3419-3439, 2020 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-32918590

RESUMO

KEY MESSAGE: Two novel major effect loci (Sen4 and Sen5) and several minor effect QTLs for potato wart disease resistance have been mapped. The importance of minor effect loci to bring full resistance to wart disease was investigated. Using the newly identified and known wart disease resistances, a panel of potato breeding germplasm and Solanum wild species was screened. This provided a state-of-the-art "hitch-hikers-guide" of complementary wart disease resistance sources. Potato wart disease, caused by the obligate biotrophic soil-born fungus Synchytrium endobioticum, is the most important quarantine disease of potato. Because of its huge impact on yield, the lack of chemical control and the formation of resting spores with long viability, breeding for resistant varieties combined with strict quarantine measures are the only way to efficiently and durably manage the disease. In this study, we set out to make an inventory of the different resistance sources. Using a Genome-Wide Association Study (GWAS) in the potato breeding genepool, we identified Sen4, associated with pathotypes 2, 6 and 18 resistance. Associated SNPs mapped to the south arm of chromosome 12 and were validated to be linked to resistance in one full-sib population. Also, a bulked segregant analysis combined with a Comparative Subsequence Sets Analysis (CoSSA) resulted in the identification of Sen5, associated with pathotypes 2, 6 and 18 resistance, on the south arm of chromosome 5. In addition to these two major effect loci, the GWAS and CoSSA allowed the identification of several quantitative trait loci necessary to bring full resistance to certain pathotypes. Panels of varieties and Solanum accessions were screened for the presence of Sen1, Sen2, Sen3, Sen4 and Sen5. Combined with pedigree analysis, we could trace back some of these genes to the ancestral resistance donors. This analysis revealed complementary resistance sources and allows elimination of redundancy in wart resistance breeding programs.


Assuntos
Cromossomos de Plantas/genética , Quitridiomicetos/fisiologia , Resistência à Doença/genética , Doenças das Plantas/genética , Proteínas de Plantas/genética , Locos de Características Quantitativas , Solanum tuberosum/genética , Mapeamento Cromossômico/métodos , Resistência à Doença/imunologia , Regulação da Expressão Gênica de Plantas , Estudo de Associação Genômica Ampla , Melhoramento Vegetal , Doenças das Plantas/microbiologia , Solanum tuberosum/imunologia , Solanum tuberosum/microbiologia
11.
J Vis ; 20(8): 25, 2020 08 03.
Artigo em Inglês | MEDLINE | ID: mdl-32841318

RESUMO

Selective attention can be directed not only to external sensory inputs, but also to internal sensory representations held within visual working memory (VWM). To date, this phenomenon has been studied predominantly following retrospective cues directing attention to particular items, or their locations in memory. In addition to item-level attentional prioritization, recent studies have shown that selectively attending to feature dimensions in VWM can also improve memory recall performance. However, no study to date has directly compared item-based and dimension-based attention in VWM, nor their neural bases. Here, we compared the benefits of retrospective cues (retro-cues) that were directed either at a multifeature item or at a feature dimension that was shared between two spatially segregated items. Behavioral results revealed qualitatively similar attentional benefits in both recall accuracy and response time, but also showed that cueing benefits were larger after item cues. Concurrent electroencephalogram measurements further revealed a similar attenuation of posterior alpha oscillations following both item and dimension retro-cues when compared with noninformative, neutral retro-cues. We argue that attention can act flexibly to prioritize the most relevant information-at either the item or the dimension level-to optimize ensuing memory-based task performance, and we discuss the implications of the observed commonalities and differences between item-level and dimension-level prioritization in VWM.


Assuntos
Encéfalo/fisiologia , Memória de Curto Prazo/fisiologia , Rememoração Mental/fisiologia , Adolescente , Adulto , Viés de Atenção , Cognição/fisiologia , Sinais (Psicologia) , Eletroencefalografia , Feminino , Humanos , Masculino , Tempo de Reação , Estudos Retrospectivos , Análise e Desempenho de Tarefas , Percepção Visual/fisiologia , Adulto Jovem
12.
Psychol Med ; 49(1): 149-161, 2019 01.
Artigo em Inglês | MEDLINE | ID: mdl-29540253

RESUMO

BACKGROUND: Which neighbourhood factors most consistently impact on depression and anxiety remains unclear. This study examines whether objectively obtained socioeconomic, physical and social aspects of the neighbourhood in which persons live are associated with the presence and severity of depressive and anxiety disorders. METHODS: Cross-sectional data are from the Netherlands Study of Depression and Anxiety including participants (n = 2980) with and without depressive and anxiety disorders in the past year (based on DSM-based psychiatric interviews). We also determined symptom severity of depression (Inventory of Depression Symptomatology), anxiety (Beck Anxiety Inventory) and fear (Fear Questionnaire). Neighbourhood characteristics comprised socioeconomic factors (socioeconomic status, home value, number of social security beneficiaries and percentage of immigrants), physical factors (air pollution, traffic noise and availability of green space and water) and social factors (social cohesion and safety). Multilevel regression analyses were performed with the municipality as the second level while adjusting for individual sociodemographic variables and household income. RESULTS: Not urbanization grade, but rather neighbourhood socioecononomic factors (low socioeconomic status, more social security beneficiaries and more immigrants), physical factors (high levels of traffic noise) and social factors (lower social cohesion and less safety) were associated with the presence of depressive and anxiety disorders. Most of these neighbourhood characteristics were also associated with increased depressive and anxiety symptoms severity. CONCLUSION: These findings suggest that it is not population density in the neighbourhood, but rather the quality of socioeconomic, physical and social neighbourhood characteristics that is associated with the presence and severity of affective disorders.


Assuntos
Transtornos de Ansiedade/epidemiologia , Transtorno Depressivo/epidemiologia , Ruído dos Transportes/estatística & dados numéricos , Características de Residência/estatística & dados numéricos , Segurança/estatística & dados numéricos , Meio Social , Fatores Socioeconômicos , Adolescente , Adulto , Idoso , Estudos Transversais , Feminino , Seguimentos , Humanos , Masculino , Pessoa de Meia-Idade , Países Baixos/epidemiologia , Índice de Gravidade de Doença , Urbanização , Adulto Jovem
13.
Eur Arch Otorhinolaryngol ; 275(2): 451-457, 2018 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-29177627

RESUMO

AIM: We aimed to investigate the potential of 3D virtual planning of tracheostomy tube placement and 3D cannula design to prevent tracheostomy complications due to inadequate cannula position. MATERIALS AND METHODS: 3D models of commercially available cannula were positioned in 3D models of the airway. In study (1), a cohort that underwent tracheostomy between 2013 and 2015 was selected (n = 26). The cannula was virtually placed in the airway in the pre-operative CT scan and its position was compared to the cannula position on post-operative CT scans. In study (2), a cohort with neuromuscular disease (n = 14) was analyzed. Virtual cannula placing was performed in CT scans and tested if problems could be anticipated. Finally (3), for a patient with Duchenne muscular dystrophy and complications of conventional tracheostomy cannula, a patient-specific cannula was 3D designed, fabricated, and placed. RESULTS: (1) The 3D planned and post-operative tracheostomy position differed significantly. (2) Three groups of patients were identified: (A) normal anatomy; (B) abnormal anatomy, commercially available cannula fits; and (C) abnormal anatomy, custom-made cannula, may be necessary. (3) The position of the custom-designed cannula was optimal and the trachea healed. CONCLUSIONS: Virtual planning of the tracheostomy did not correlate with actual cannula position. Identifying patients with abnormal airway anatomy in whom commercially available cannula cannot be optimally positioned is advantageous. Patient-specific cannula design based on 3D virtualization of the airway was beneficial in a patient with abnormal airway anatomy.


Assuntos
Cânula , Impressão Tridimensional , Traqueia/anatomia & histologia , Traqueia/diagnóstico por imagem , Traqueostomia/instrumentação , Traqueostomia/métodos , Adulto , Idoso , Desenho de Equipamento/métodos , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Distrofia Muscular de Duchenne/patologia , Distrofia Muscular de Duchenne/terapia , Doenças Neuromusculares/patologia , Doenças Neuromusculares/terapia , Complicações Pós-Operatórias/prevenção & controle , Tomografia Computadorizada por Raios X , Traqueia/patologia , Traqueostomia/efeitos adversos
14.
Br J Clin Psychol ; 55(3): 225-35, 2016 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-25816887

RESUMO

OBJECTIVE: Cognitive models have suggested that extreme appraisals of affective states and maladaptive affect regulation strategies are important in the development of bipolar symptomatology. Little is known about the pathway by which these appraisals and behaviours interact in the formation of activated and depressed affective states. This study tested the predictions that (1) ascent behaviours mediate the relationship between positive appraisals of activated mood and activation; and (2) descent behaviours mediate the relationship between negative appraisals of activated mood and depression. METHOD: A total of 52 individuals with a DSM-IV diagnosis of bipolar I or II disorder (confirmed by structured interview) completed biweekly assessments of affect regulation behaviours and mood for 4 weeks. Positive and negative appraisals of affective states were assessed at baseline through the Hypomanic Attitudes and Positive Prediction Inventory. Multilevel mediation analysis was used to explore the data. RESULTS: Ascent behaviours partially mediated the relationship between positive appraisals of activated mood and activation. Descent behaviours, but not negative appraisals of activated mood, predicted levels of depression indicating the absence of a mediation effect. CONCLUSION: The results suggest that positive appraisals of activated mood can escalate activation in individuals with bipolar disorder. Such appraisals may be inherently rewarding and reinforcing directly elevating levels of activation, whilst increasing individuals' use of ascent behaviours. The results are consistent with the view that appraisals and behaviours should be targeted during cognitive behavioural therapy for bipolar disorder. PRACTITIONER POINTS: It may be beneficial to target positive appraisals of activated mood in cognitive behavioural therapy for mania. Cognitive behavioural therapists may also wish to focus on identifying and targeting individuals' use of ascent behaviours to reduce highly activated states.


Assuntos
Afeto , Transtorno Bipolar/psicologia , Terapia Cognitivo-Comportamental/métodos , Depressão/psicologia , Transtorno Depressivo/psicologia , Inventário de Personalidade , Adolescente , Transtorno Bipolar/terapia , Cognição , Estudos Transversais , Depressão/terapia , Transtorno Depressivo/terapia , Manual Diagnóstico e Estatístico de Transtornos Mentais , Feminino , Humanos , Masculino , Valor Preditivo dos Testes
15.
Ann Neurol ; 76(1): 95-107, 2014 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-24891139

RESUMO

OBJECTIVE: Lesch-Nyhan disease (LND) is caused by congenital deficiency of the purine recycling enzyme, hypoxanthine-guanine phosphoribosyltransferase (HGprt). Affected patients have a peculiar neurobehavioral syndrome linked with reductions of dopamine in the basal ganglia. The purpose of the current studies was to determine the anatomical basis for the reduced dopamine in human brain specimens collected at autopsy. METHODS: Histopathological studies were conducted using autopsy tissue from 5 LND cases and 6 controls. Specific findings were replicated in brain tissue from an HGprt-deficient knockout mouse using immunoblots, and in a cell model of HGprt deficiency by flow-activated cell sorting (FACS). RESULTS: Extensive histological studies of the LND brains revealed no signs suggestive of a degenerative process or other consistent abnormalities in any brain region. However, neurons of the substantia nigra from the LND cases showed reduced melanization and reduced immunoreactivity for tyrosine hydroxylase (TH), the rate-limiting enzyme in dopamine synthesis. In the HGprt-deficient mouse model, immunohistochemical stains for TH revealed no obvious loss of midbrain dopamine neurons, but quantitative immunoblots revealed reduced TH expression in the striatum. Finally, 10 independent HGprt-deficient mouse MN9D neuroblastoma lines showed no signs of impaired viability, but FACS revealed significantly reduced TH immunoreactivity compared to the control parent line. INTERPRETATION: These results reveal an unusual phenomenon in which the neurochemical phenotype of dopaminergic neurons is not linked with a degenerative process. They suggest an important relationship between purine recycling pathways and the neurochemical integrity of the dopaminergic phenotype.


Assuntos
Dopamina/deficiência , Neurônios Dopaminérgicos/patologia , Síndrome de Lesch-Nyhan/genética , Síndrome de Lesch-Nyhan/patologia , Mesencéfalo/enzimologia , Mesencéfalo/patologia , Fenótipo , Adulto , Idoso , Idoso de 80 Anos ou mais , Animais , Linhagem Celular Tumoral , Criança , Pré-Escolar , Corpo Estriado/enzimologia , Corpo Estriado/patologia , Modelos Animais de Doenças , Dopamina/genética , Neurônios Dopaminérgicos/enzimologia , Humanos , Hipoxantina Fosforribosiltransferase/deficiência , Hipoxantina Fosforribosiltransferase/genética , Síndrome de Lesch-Nyhan/enzimologia , Masculino , Camundongos , Camundongos Endogâmicos C57BL , Camundongos Knockout , Pessoa de Meia-Idade , Substância Negra/enzimologia , Substância Negra/patologia , Tirosina 3-Mono-Oxigenase/deficiência , Tirosina 3-Mono-Oxigenase/genética , Adulto Jovem
16.
Brain ; 137(Pt 5): 1282-303, 2014 May.
Artigo em Inglês | MEDLINE | ID: mdl-23975452

RESUMO

Establishing meaningful relationships between genetic variations and clinical disease is a fundamental goal for all human genetic disorders. However, these genotype-phenotype correlations remain incompletely characterized and sometimes conflicting for many diseases. Lesch-Nyhan disease is an X-linked recessive disorder that is caused by a wide variety of mutations in the HPRT1 gene. The gene encodes hypoxanthine-guanine phosphoribosyl transferase, an enzyme involved in purine metabolism. The fine structure of enzyme has been established by crystallography studies, and its function can be measured with very precise biochemical assays. This rich knowledge of genetic alterations in the gene and their functional effect on its protein product provides a powerful model for exploring factors that influence genotype-phenotype correlations. The present study summarizes 615 known genetic mutations, their influence on the gene product, and their relationship to the clinical phenotype. In general, the results are compatible with the concept that the overall severity of the disease depends on how mutations ultimately influence enzyme activity. However, careful evaluation of exceptions to this concept point to several additional genetic and non-genetic factors that influence genotype-phenotype correlations. These factors are not unique to Lesch-Nyhan disease, and are relevant to most other genetic diseases. The disease therefore serves as a valuable model for understanding the challenges associated with establishing genotype-phenotype correlations for other disorders.


Assuntos
Estudos de Associação Genética , Hipoxantina Fosforribosiltransferase/genética , Síndrome de Lesch-Nyhan/genética , Síndrome de Lesch-Nyhan/fisiopatologia , Mutação/genética , Animais , Humanos
17.
Haematologica ; 99(5): 848-57, 2014 May.
Artigo em Inglês | MEDLINE | ID: mdl-24441149

RESUMO

Acute myeloid leukemia is a neoplasm characterized by recurrent molecular aberrations traditionally demonstrated by cytogenetic analyses. We used high density genome-wide genotyping and gene expression profiling to reveal acquired cryptic abnormalities in acute myeloid leukemia. By genome-wide genotyping of 137 cases of primary acute myeloid leukemia, we disclosed a recurrent focal amplification on chromosome 14q32, which included the genes BCL11B, CCNK, C14orf177 and SETD3, in two cases. In the affected cases, the BCL11B gene showed consistently high mRNA expression, whereas the expression of the other genes was unperturbed. Fluorescence in situ hybridization on 40 cases of acute myeloid leukemia with high BCL11B mRNA expression [2.5-fold above median; 40 out of 530 cases (7.5%)] revealed 14q32 abnormalities in two additional cases. In the four BCL11B-rearranged cases the 14q32 locus was fused to different partner chromosomes. In fact, in two cases, we demonstrated that the focal 14q32 amplifications were integrated into transcriptionally active loci. The translocations involving BCL11B result in increased expression of full-length BCL11B protein. The BCL11B-rearranged acute myeloid leukemias expressed both myeloid and T-cell markers. These biphenotypic acute leukemias all carried FLT3 internal tandem duplications, a characteristic marker of acute myeloid leukemia. BCL11B mRNA expression in acute myeloid leukemia appeared to be strongly associated with expression of other T-cell-specific genes. Myeloid 32D(GCSF-R) cells ectopically expressing Bcl11b showed decreased proliferation rate and less maturation. In conclusion, by an integrated approach involving high-throughput genome-wide genotyping and gene expression profiling we identified BCL11B as a candidate oncogene in acute myeloid leukemia.


Assuntos
Aberrações Cromossômicas , Cromossomos Humanos Par 14 , Leucemia Mieloide Aguda/genética , Oncogenes , Proteínas Repressoras/genética , Proteínas Supressoras de Tumor/genética , Antígenos de Superfície/metabolismo , Estudos de Casos e Controles , Proliferação de Células , Dosagem de Genes , Expressão Gênica , Perfilação da Expressão Gênica , Estudo de Associação Genômica Ampla , Genótipo , Humanos , Imunofenotipagem , Hibridização in Situ Fluorescente , Leucemia Mieloide Aguda/diagnóstico , Leucemia Mieloide Aguda/metabolismo , Polimorfismo de Nucleotídeo Único , Análise de Sequência de DNA , Linfócitos T/metabolismo , Translocação Genética
18.
Pediatr Neurol ; 155: 156-159, 2024 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-38653184

RESUMO

BACKGROUND: In Lesch-Nyhan disease (LND), early dopamine deficiency is thought to contribute to dystonia and self-injury, gradually developing over the first years of life. Previous attempts to restore dopamine levels in older patients have been unsuccessful. Based on the hypothesis that very early dopamine replacement can prevent full phenotypic development, we treated three patients with LND from infancy with levodopa. METHODS: Levodopa/carbidopa (4:1) was started at age 11 to 13 months, aiming at escalating to 5 to 6 mg/kg levodopa per day. Follow-up focused on dystonia severity and whether self-injury occurred. In addition, the literature was reviewed to delineate the age at onset of self-injury for all reported cases to date. RESULTS: During long-term follow-up, self-injury appears to have been prevented in two patients (now aged 14 and 15.5 years), as their HPRT1 gene mutations had been invariably associated with self-injury before. Future self-injury is unlikely, as only 1.1% of 264 published cases had self-injury onset later in life than these patients' current ages. The third patient started self-injury at age 1.5 years, while on a substantially lower levodopa dose. A clear effect of levodopa on dystonia could not be determined. CONCLUSIONS: Our observations suggest that levodopa, given early enough and sufficiently dosed, might be able to prevent self-injury in LND. Therefore, levodopa could be considered in patients with LND as early as possible, at least before the self-injury appears. Further research is needed to establish very early levodopa as an effective treatment strategy in LND, and to optimize timing and dosing.


Assuntos
Síndrome de Lesch-Nyhan , Levodopa , Comportamento Autodestrutivo , Humanos , Levodopa/administração & dosagem , Síndrome de Lesch-Nyhan/tratamento farmacológico , Comportamento Autodestrutivo/tratamento farmacológico , Comportamento Autodestrutivo/prevenção & controle , Comportamento Autodestrutivo/etiologia , Adolescente , Masculino , Feminino , Lactente , Carbidopa/administração & dosagem , Carbidopa/farmacologia , Dopaminérgicos/administração & dosagem , Dopaminérgicos/farmacologia , Combinação de Medicamentos
19.
BMC Psychiatry ; 13: 34, 2013 Jan 23.
Artigo em Inglês | MEDLINE | ID: mdl-23343329

RESUMO

BACKGROUND: Over the past decade policy makers have emphasised the importance of healthcare technology in the management of long-term conditions. Mobile-phone based assessment may be one method of facilitating clinically- and cost-effective intervention, and increasing the autonomy and independence of service users. Recently, text-message and smartphone interfaces have been developed for the real-time assessment of symptoms in individuals with schizophrenia. Little is currently understood about patients' perceptions of these systems, and how they might be implemented into their everyday routine and clinical care. METHOD: 24 community based individuals with non-affective psychosis completed a randomised repeated-measure cross-over design study, where they filled in self-report questions about their symptoms via text-messages on their own phone, or via a purpose designed software application for Android smartphones, for six days. Qualitative interviews were conducted in order to explore participants' perceptions and experiences of the devices, and thematic analysis was used to analyse the data. RESULTS: Three themes emerged from the data: i) the appeal of usability and familiarity, ii) acceptability, validity and integration into domestic routines, and iii) perceived impact on clinical care. Although participants generally found the technology non-stigmatising and well integrated into their everyday activities, the repetitiveness of the questions was identified as a likely barrier to long-term adoption. Potential benefits to the quality of care received were seen in terms of assisting clinicians, faster and more efficient data exchange, and aiding patient-clinician communication. However, patients often failed to see the relevance of the systems to their personal situations, and emphasised the threat to the person centred element of their care. CONCLUSIONS: The feedback presented in this paper suggests that patients are conscious of the benefits that mobile-phone based assessment could bring to clinical care, and that the technology can be successfully integrated into everyday routine. However, it also suggests that it is important to demonstrate to patients the personal, as well as theoretical, benefits of the technology. In the future it will be important to establish whether clinical practitioners are able to use this technology as part of a personalised mental health regime.


Assuntos
Telefone Celular , Esquizofrenia/diagnóstico , Atividades Cotidianas , Adulto , Estudos Cross-Over , Feminino , Humanos , Masculino , Satisfação do Paciente , Transtornos Psicóticos/diagnóstico , Transtornos Psicóticos/psicologia , Reprodutibilidade dos Testes , Psicologia do Esquizofrênico , Envio de Mensagens de Texto
20.
J Med Internet Res ; 15(4): e60, 2013 Apr 05.
Artigo em Inglês | MEDLINE | ID: mdl-23563184

RESUMO

BACKGROUND: Mobile phone-based assessment may represent a cost-effective and clinically effective method of monitoring psychotic symptoms in real-time. There are several software options, including the use of native smartphone applications and text messages (short message service, SMS). Little is known about the strengths and limitations of these two approaches in monitoring symptoms in individuals with serious mental illness. OBJECTIVE: The objective of this study was to compare two different delivery modalities of the same diagnostic assessment for individuals with non-affective psychosis-a native smartphone application employing a graphical, touch user interface against an SMS text-only implementation. The overall hypothesis of the study was that patient participants with sewrious mental illness would find both delivery modalities feasible and acceptable to use, measured by the quantitative post-assessment feedback questionnaire scores, the number of data points completed, and the time taken to complete the assessment. It was also predicted that a native smartphone application would (1) yield a greater number of data points, (2) take less time, and (3) be more positively appraised by patient participant users than the text-based system. METHODS: A randomized repeated measures crossover design was employed. Participants with currently treated Diagnostic and Statistical Manual (Fourth Edition) schizophrenia or related disorders (n=24) were randomly allocated to completing 6 days of assessment (four sets of questions per day) with a native smartphone application or the SMS text-only implementation. There was then a 1-week break before completing a further 6 days with the alternative delivery modality. Quantitative feedback questionnaires were administered at the end of each period of sampling. RESULTS: A greater proportion of data points were completed with the native smartphone application in comparison to the SMS text-only implementation (ß = -.25, SE=.11, P=.02), which also took significantly less time to complete (ß =.78, SE= .09, P<.001). Although there were no significant differences in participants' quantitative feedback for the two delivery modalities, most participants reported preferring the native smartphone application (67%; n=16) and found it easier to use (71%; n=16). 33% of participants reported that they would be willing to complete mobile phone assessment for 5 weeks or longer. CONCLUSIONS: Native smartphone applications and SMS text are both valuable methods of delivering real-time assessment in individuals with schizophrenia. However, a more streamlined graphical user interface may lead to better compliance and shorter entry times. Further research is needed to test the efficacy of this technology within clinical services, to assess validity over longer periods of time and when delivered on patients' own phones.


Assuntos
Telefone Celular , Transtornos Psicóticos/diagnóstico , Telemedicina/métodos , Envio de Mensagens de Texto , Estudos Cross-Over , Humanos , Cooperação do Paciente , Esquizofrenia/diagnóstico , Inquéritos e Questionários
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