RESUMO
OBJECTIVE: Many women with epilepsy need to continue anti-seizure medications (ASMs) throughout pregnancy. The current study investigated adaptive behaviour outcomes in children exposed to topiramate in the womb. METHOD: An observational, cross-sectional study was designed, recruiting mother-child-pairs from the UK Epilepsy and Pregnancy Register (UKEPR). Health, developmental histories and Vineland Adaptive Behaviour Scale-Third Edition (VABS-III) assessments were administered via telephone by a blinded researcher, supplemented with prospectively collected pregnancy and medication information. Topiramate monotherapy exposed children were compared to VABS-III normative data as recruitment was disrupted by the COVID-19 pandemic. RESULTS: Thirty-four women with epilepsy from 135 (25%) initially agreed to participate in the study, of whom 26 women completed telephone interviews about their children (n = 28). Children ranged from 2.5 to 17 years of age at the time of assessment. Six topiramate-exposed children were born small for gestational age, and there were significant associations between birthweight, dose and VABS-III scores. Significantly lower scores were observed in topiramate-exposed children (n = 21) with a significant dose-response relationship established after adjustment for parental educational level. Daily mean dosage was 280.21 mg, with high dosages of topiramate associated with a 12-point reduction in VABS-III scores. Additionally, four topiramate-exposed children (19.05%) had diagnoses of Autism Spectrum Disorder, which was significantly higher than UK prevalence rates (1.1%). CONCLUSIONS: The findings of poorer adaptive behaviour, higher incidence of ASD and associations with birth weight are of concern and require further validation and replication using larger prospectively-recruited samples and comparator cohorts. Implications for research and clinical practice are discussed.
Assuntos
Transtorno do Espectro Autista , COVID-19 , Epilepsia , Gravidez , Humanos , Feminino , Topiramato/efeitos adversos , Anticonvulsivantes/efeitos adversos , Transtorno do Espectro Autista/epidemiologia , Estudos Transversais , Pandemias , COVID-19/epidemiologia , Epilepsia/tratamento farmacológico , Epilepsia/epidemiologia , Epilepsia/diagnóstico , Estudos de Coortes , Adaptação PsicológicaRESUMO
BACKGROUND: Animal data suggest teratogenic effects with zonisamide use and risk of pregnancy losses. Human data following zonisamide exposure are presently limited, but suggest low risk of malformation with elevated risk of low birth weight. OBJECTIVE: To calculate the major congenital malformation (MCM) rate of zonisamide in human pregnancy and assess for a signal of any specific malformation pattern and associations with birth weight. METHODS AND MATERIALS: Data were obtained from the UK and Ireland Epilepsy and Pregnancy register (UKIEPR) which is an observational, registration, and follow up study from December 1996 to July 2020. Eligibility criteria were use of zonisamide and to have been referred to the UKIEPR before the outcome of the pregnancy was known. Primary outcome was evidence of MCM. RESULTS: From December 1996 through July 2020 there were 112 cases of first trimester exposure to zonisamide, including 26 monotherapy cases. There were 3 MCM for monotherapy cases (MCM rate 13.0% (95% confidence interval 4.5-32.1)), and 5 MCM for polytherapy cases (MCM rate 6.9% (95% confidence interval 3.0-15.2)). While the median birth weight was on 71st and 44th centile for monotherapy and polytherapy cases respectively, there was a high rate of infants born small for gestational age (21% for both). CONCLUSION: These data raise concerns about a signal for potential teratogenicity with zonisamide in human pregnancy. Given the low numbers reported, further data will be required to adequately counsel women who use zonisamide in pregnancy.
Assuntos
Anormalidades Induzidas por Medicamentos , Epilepsia , Complicações na Gravidez , Anormalidades Induzidas por Medicamentos/epidemiologia , Anormalidades Induzidas por Medicamentos/etiologia , Anticonvulsivantes/efeitos adversos , Epilepsia/tratamento farmacológico , Epilepsia/epidemiologia , Feminino , Seguimentos , Humanos , Irlanda/epidemiologia , Gravidez , Complicações na Gravidez/induzido quimicamente , Complicações na Gravidez/tratamento farmacológico , Complicações na Gravidez/epidemiologia , Resultado da Gravidez/epidemiologia , Sistema de Registros , Reino Unido/epidemiologia , Zonisamida/uso terapêuticoRESUMO
We have performed a parallel tempering crankshaft motion Monte Carlo simulation on a model of the GABA type A receptor with the aim of exploring a wide variety of local conformational space. We develop a novel method to analyse the protein movements in terms of a correlation tensor and use this to explore the gating process, that is, how agonist binding could cause ion channel opening. We find that simulated binding impulses to varying clusters of GABA binding site residues produce channel opening, and that equivalent impulses to single GABA sites produce partial opening.
Assuntos
Simulação de Dinâmica Molecular , Receptores de GABA-A/química , Sítios de Ligação , Humanos , Método de Monte Carlo , Conformação ProteicaRESUMO
We describe a novel deep learning neural network method and its application to impute assay pIC50 values. Unlike conventional machine learning approaches, this method is trained on sparse bioactivity data as input, typical of that found in public and commercial databases, enabling it to learn directly from correlations between activities measured in different assays. In two case studies on public domain data sets we show that the neural network method outperforms traditional quantitative structure-activity relationship (QSAR) models and other leading approaches. Furthermore, by focusing on only the most confident predictions the accuracy is increased to R2 > 0.9 using our method, as compared to R2 = 0.44 when reporting all predictions.
Assuntos
Aprendizado Profundo , Preparações Farmacêuticas/química , Bioensaio/métodos , Bases de Dados de Produtos Farmacêuticos , Descoberta de Drogas/métodos , Estrutura Molecular , Relação Quantitativa Estrutura-AtividadeRESUMO
Functional synaptic networks are compromised in many neurodevelopmental and neurodegenerative diseases. While the mechanisms of axonal transport and localization of synaptic vesicles and mitochondria are relatively well studied, little is known about the mechanisms that regulate the localization of proteins that localize to active zones. Recent finding suggests that mechanisms involved in transporting proteins destined to active zones are distinct from those that transport synaptic vesicles or mitochondria. Here we report that localization of BRP-an essential active zone scaffolding protein in Drosophila, depends on the precise balance of neuronal Par-1 kinase. Disruption of Par-1 levels leads to excess accumulation of BRP in axons at the expense of BRP at active zones. Temporal analyses demonstrate that accumulation of BRP within axons precedes the loss of synaptic function and its depletion from the active zones. Mechanistically, we find that Par-1 co-localizes with BRP and is present in the same molecular complex, raising the possibility of a novel mechanism for selective localization of BRP-like active zone scaffolding proteins. Taken together, these data suggest an intriguing possibility that mislocalization of active zone proteins like BRP might be one of the earliest signs of synapse perturbation and perhaps, synaptic networks that precede many neurological disorders.
Assuntos
Proteínas de Drosophila/metabolismo , Drosophila melanogaster/metabolismo , Quinase 3 da Glicogênio Sintase/metabolismo , Junção Neuromuscular/metabolismo , Sinapses/metabolismo , Animais , Axônios/metabolismo , Axônios/ultraestrutura , Larva/metabolismo , Larva/ultraestrutura , Proteínas Associadas aos Microtúbulos/metabolismo , Terminações Pré-Sinápticas/metabolismo , Transporte Proteico , Sinapses/ultraestruturaRESUMO
We have performed docking simulations on GABARAP interacting with the GABA type A receptor using SwarmDock. We have also used a novel method to study hydration sites on the surface of these two proteins; this method identifies regions around proteins where desolvation is relatively easy, and these are possible locations where proteins can bind each other. There is a high degree of consistency between the predictions of these two methods. Moreover, we have also identified binding sites on GABARAP for other proteins, and listed possible binding sites for as yet unknown proteins on both GABARAP and the GABA type A receptor intracellular domain.
Assuntos
Proteínas Adaptadoras de Transdução de Sinal/química , Proteínas Associadas aos Microtúbulos/química , Simulação de Acoplamento Molecular , Receptores de GABA-A/química , Proteínas Reguladoras de Apoptose , Sítios de Ligação , Bases de Dados de Proteínas , Humanos , Conformação Proteica , Multimerização Proteica , TermodinâmicaRESUMO
Objective: To describe the natural history of cardiomyopathy in patients with Duchenne muscular dystrophy (DMD) who are receiving contemporary therapies. Methods: This is a single-institution retrospective cohort study of 57 patients aged >15 years with DMD. Serial digital echocardiograms were performed over a median follow-up of 8 years. Left ventricular dysfunction (LVD) was defined as shortening fraction (SF) <29% plus focal wall motion abnormalities. Therapies included ACE inhibitors, beta-blockers and assisted ventilation. Results: The SF declined progressively in 53/57 patients (93%). LVD occurred in 40 of 57 patients (70%), with variable age at onset (median 18 years, IQR 14-21.5 years). Rate of SF decline (-1.51%±1.16%/year) was variable and unrelated to genotype. However, survival was shorter for patients with LVD onset at age <18 years vs onset at ≥18 years (death at 21.1±2.5 years vs 33.1±4.4 years; P<0.001). Death occurred in 27/57 (47%) patients at a median age of 26.3 years (IQR 20.6-31.5). Death was preceded by LVD in 22/27 patients (81%), 15 (68%) of whom developed class 4 heart failure (CHF). Time from CHF to death was brief (median 8.0 months). Conclusion: Despite contemporary therapies, SF declined progressively in almost all patients. Age at onset of LVD and age at death were variable and unrelated to genotype; however, survival was shortened for patients with LVD onset at age <18 years. Death was usually preceded by LVD. CHF was a sentinel event, with death occurring shortly thereafter.
RESUMO
Purpose The purpose of this paper is to investigate the relationship between patient safety culture and two attitudinal constructs: affective organizational commitment and structural empowerment. In doing so, the main and interaction effects of the two constructs on the perception of patient safety culture were assessed using a cohort of physicians. Design/methodology/approach Affective commitment was measured with the Organizational Commitment Questionnaire, whereas structural empowerment was assessed with the Conditions of Work Effectiveness Questionnaire-II. The abbreviated versions of these surveys were administered to a cohort of 71 post-doctoral medical residents. For the data analysis, hierarchical regression analyses were performed for the main and interaction effects of affective commitment and structural empowerment on the perception of patient safety culture. Findings A total of 63 surveys were analyzed. The results revealed that both affective commitment and structural empowerment were positively related to patient safety culture. A potential interaction effect of the two attitudinal constructs on patient safety culture was tested but no such effect was detected. Research limitations/implications This study suggests that there are potential benefits of promoting affective commitment and structural empowerment for patient safety culture in health care organizations. By identifying the positive associations between the two constructs and patient safety culture, this study provides additional empirical support for Kanter's theoretical tenet that structural and organizational support together helps to shape the perceptions of patient safety culture. Originality/value Despite the wide recognition of employee empowerment and commitment in organizational research, there has still been a paucity of empirical studies specifically assessing their effects on patient safety culture in health care organizations. To the authors' knowledge, this study is the first empirical study to examine the relationship between structural empowerment as proposed by Kanter and the culture of patient safety using physicians.
Assuntos
Cultura Organizacional , Segurança do Paciente , Atitude do Pessoal de Saúde , Humanos , Política Organizacional , Segurança do Paciente/normas , Médicos/organização & administração , Médicos/psicologia , Poder Psicológico , Inquéritos e QuestionáriosRESUMO
Osteosarcoma (OS) is the most common cancer of bone. Parathyroid hormone (PTH) regulates calcium homeostasis and bone development, while the paracrine/autocrine PTH-related protein (PTHrP) has central roles in endochondral bone formation and bone remodeling. Using a murine OS model, we found that OS cells express PTHrP and the common PTH/PTHrP receptor (PTHR1). To investigate the role of PTHR1 signaling in OS cell behavior, we used shRNA to reduce PTHR1 expression. This only mildly inhibited proliferation in vitro, but markedly reduced invasion through collagen and reduced expression of RANK ligand (RANKL). Administration of PTH(1-34) did not stimulate OS proliferation in vivo but, strikingly, PTHR1 knockdown resulted in a profound growth inhibition and increased differentiation/mineralization of the tumors. Treatment with neutralizing antibody to PTHrP did not recapitulate the knockdown of PTHR1. Consistent with this lack of activity, PTHrP was predominantly intracellular in OS cells. Knockdown of PTHR1 resulted in increased expression of late osteoblast differentiation genes and upregulation of Wnt antagonists. RANKL production was reduced in knockdown tumors, providing for reduced homotypic signaling through the receptor, RANK. Loss of PTHR1 resulted in the coordinated loss of gene signatures associated with the polycomb repressive complex 2 (PRC2). Using Ezh2 inhibitors, we demonstrate that the increased expression of osteoblast maturation markers is in part mediated by the loss of PRC2 activity. Collectively these results demonstrate that PTHR1 signaling is important in maintaining OS proliferation and undifferentiated state. This is in part mediated by intracellular PTHrP and through regulation of the OS epigenome.
Assuntos
Neoplasias Ósseas/genética , Neoplasias Ósseas/patologia , Diferenciação Celular/genética , Proliferação de Células/genética , Osteossarcoma/genética , Osteossarcoma/patologia , Receptor Tipo 1 de Hormônio Paratireóideo/genética , Animais , Diferenciação Celular/efeitos dos fármacos , Proliferação de Células/efeitos dos fármacos , Regulação para Baixo/efeitos dos fármacos , Regulação para Baixo/genética , Regulação Neoplásica da Expressão Gênica/efeitos dos fármacos , Técnicas de Silenciamento de Genes , Humanos , Camundongos , Camundongos Endogâmicos BALB C , Camundongos Nus , Invasividade Neoplásica , RNA Interferente Pequeno/farmacologia , Receptor Tipo 1 de Hormônio Paratireóideo/antagonistas & inibidores , Células Tumorais CultivadasRESUMO
Synaptic scaffold proteins control the localization of ion channels and receptors, and facilitate molecular associations between signaling components that modulate synaptic transmission and plasticity. Here, we define novel roles for a recently described scaffold protein, Dsychronic (DYSC), at the Drosophila larval neuromuscular junction. DYSC is the Drosophila homolog of whirlin/DFNB31, a PDZ domain protein linked to Usher syndrome, the most common form of human deaf-blindness. We show that DYSC is expressed presynaptically and is often localized adjacent to the active zone, the site of neurotransmitter release. Loss of DYSC results in marked alterations in synaptic morphology and cytoskeletal organization. Moreover, active zones are frequently enlarged and misshapen in dysc mutants. Electrophysiological analyses further demonstrate that dysc mutants exhibit substantial increases in both evoked and spontaneous synaptic transmission. We have previously shown that DYSC binds to and regulates the expression of the Slowpoke (SLO) BK potassium channel. Consistent with this, slo mutant larvae exhibit similar alterations in synapse morphology, active zone size and neurotransmission, and simultaneous loss of dysc and slo does not enhance these phenotypes, suggesting that dysc and slo act in a common genetic pathway to modulate synaptic development and output. Our data expand our understanding of the neuronal functions of DYSC and uncover non-canonical roles for the SLO potassium channel at Drosophila synapses.
Assuntos
Proteínas de Drosophila/metabolismo , Drosophila/crescimento & desenvolvimento , Canais de Potássio Ativados por Cálcio de Condutância Alta/metabolismo , Proteínas de Membrana/metabolismo , Junção Neuromuscular/crescimento & desenvolvimento , Sinapses/fisiologia , Animais , Imuno-Histoquímica , Larva/crescimento & desenvolvimento , Potenciais da Membrana , Microscopia Confocal , Domínios PDZ/genética , Técnicas de Patch-Clamp , Reação em Cadeia da Polimerase Via Transcriptase Reversa , Sinapses/metabolismoRESUMO
The Mexico (2004), Bamako (2008) and Algiers (2008) declarations committed the South African (SA) Ministry of Health to allocate 2% of the national health budget to research, while the National Health Research Policy (2001) proposed that the country budget for health research should be 2% of total public sector health expenditure. The National Health Research Committee has performed an audit to determine whether these goals have been met, judged by: (i) health research expenditure as proportions of gross expenditure on research and development (GERD) and the gross domestic product (GDP); and (ii) the proportion of the national health and Department of Health budgets apportioned to research. We found that total expenditure on health research in SA, aggregated across the public and private sectors, was R3.5 billion in 2009/10, equating to 16.7% of GERD. However, the total government plus science council spend on health research that year was only R729 million, equating to 3.5% of GERD (0.03% of the GDP) or 0.80% of the R91.4 billion consolidated government expenditure on health. We further found that R418 million was spent through the 2009/2010 Health Vote on health research, equating to 0.46% of the consolidated government expenditure on health or 0.9% of the R45.2 billion Health Vote. Data from other recent years were similar. Current SA public sector health research allocations therefore remain well below the aspirational goal of 2% of the national health budget. We recommend that new, realistic, clearly defined targets be adopted and an efficient monitoring mechanism be developed to track future health research expenditure.
Assuntos
Benchmarking/métodos , Pesquisa Biomédica/organização & administração , Alocação de Recursos para a Atenção à Saúde/organização & administração , Gastos em Saúde/estatística & dados numéricos , Auditoria Financeira/estatística & dados numéricos , Financiamento Governamental/estatística & dados numéricos , Política de Saúde , Humanos , Saúde Pública/economia , Apoio à Pesquisa como Assunto/estatística & dados numéricos , África do SulRESUMO
Prognosis in patients with Duchenne muscular dystrophy (DMD) is guarded, and most deaths are due to cardiac or respiratory causes. It is unclear if some DMD gene mutations might be predictive of either mild or severe cardiac dysfunction. We studied 75 patients with DMD followed at our institution. Cardiac function, as assessed by yearly echocardiography, showed marked variability in left ventricular (LV) function. Some patients in their 3rd decade had no or minimal dysfunction, whereas others in their 2nd decade had very severe dysfunction. Therefore, 4 severity groups were defined ranging from no or mild LV dysfunction to severe LV dysfunction using patient age at first abnormal echocardiographic finding and degree of LV dysfunction. Genetic data were collected for all patients. Most patients had mutations from exon 1 to 20 to exon 41 to 55. The distribution of the 4 severity groups of LV dysfunction did not significantly differ between these 2 mutation groups. An analysis based on the number of exons involved (<5 vs ≥5 exons) also found no significant difference in cardiac severity. When patients having identical mutations were compared with their cardiac course, concordance was often not evident. Steroid therapy had no apparent protection for the development of cardiomyopathy. In conclusion, 75 patients with DMD showed marked variability in the severity of LV dysfunction. Neither the age of onset nor the severity of cardiomyopathy correlated with any of the mutation groups.
Assuntos
Distrofia Muscular de Duchenne/genética , Disfunção Ventricular Esquerda/etiologia , Função Ventricular Esquerda , Adolescente , DNA/genética , Análise Mutacional de DNA , Progressão da Doença , Distrofina/genética , Ecocardiografia , Éxons , Feminino , Seguimentos , Genótipo , Humanos , Masculino , Distrofia Muscular de Duchenne/complicações , Mutação , Estudos Retrospectivos , Disfunção Ventricular Esquerda/diagnóstico por imagem , Disfunção Ventricular Esquerda/fisiopatologia , Adulto JovemRESUMO
PRIMARY OBJECTIVE: To determine whether photosensitivity (PS) changes over time and, if so, what factors may be related to the change; furthermore, to determine whether tint density changes over time, all in mild traumatic brain injury (mTBI). DESIGN AND METHODS: A retrospective analysis of 62 patient records (aged 18-40 years) with mTBI and PS was conducted. All charts were obtained from the SUNY/College of Optometry clinics from 2004-2011. RESULTS: Fifty per cent demonstrated reduced PS over time, with most occurring after year 1 post-injury (40%). Promotion of PS reduction appears to be associated with the lack of spectacle tint usage (p = 0.01) and the use of contact lenses (p = 0.03). Inhibition of PS reduction appears to be associated with tinted lenses (p = 0.06), hyperacusis (p = 0.03), dry eye (p = 0.04), migraines (p = 0.03) and loss of consciousness at the time of injury (p = 0.05). Concerning tint density changes over time, 71% (p = 0.002) maintained the same degree over time, while 27% (p = 0.002) reduced and 2% waxed and waned. CONCLUSION: Neural adaptation to PS appears to be a long-term process. Tint usage may act to inhibit this adaptive process, while the use of contact lenses may act to promote it. These findings may provide guidance in the clinical management of photosensitivity in the mTBI population.
Assuntos
Lesões Encefálicas/fisiopatologia , Lentes de Contato , Óculos , Transtornos de Fotossensibilidade/fisiopatologia , Adulto , Lesões Encefálicas/complicações , Cor , Síndromes do Olho Seco , Desenho de Equipamento , Feminino , Seguimentos , Humanos , Hiperacusia , Masculino , Transtornos de Enxaqueca , Transtornos de Fotossensibilidade/etiologia , Recuperação de Função Fisiológica , Estudos Retrospectivos , Acuidade VisualRESUMO
OBJECTIVE: To compare the cognitive and language development of children born to women with epilepsy (WWE) exposed in utero to levetiracetam (LEV) or sodium valproate (VPA) and control children born to women without epilepsy not taking medication during pregnancy. METHODS: The children, aged between 36 and 54 months, were recruited from the United Kingdom and assessed using the Griffiths Mental Development Scales and the Reynell Language Development Scale. Maternal demographic and epilepsy information was also collected for use in statistical regression. This is an observational study with researchers not involved in the clinical management of the mothers enrolled. RESULTS: After controlling for confounding variables, children exposed to LEV in utero (n = 53) did not differ from unexposed control children (n = 131) on any scale administered. Children exposed to VPA (n = 44) in utero scored, on average, 15.8 points below children exposed to LEV on measures of gross motor skills (95% confidence interval [CI] -24.5 to -7.1, p < 0.001), 6.4 points below on comprehension language abilities (95% CI -11.0 to -1.8, p = 0.005), and 9.5 points below on expressive language abilities (95% CI -14.7 to -4.4, p < 0.001). CONCLUSION: The current study indicates that children exposed to LEV in utero were superior in their language and motor development in comparison to children exposed to VPA. This information should be used collaboratively between health care professionals and WWE when deciding on women's preferred choice of antiepileptic drug.
Assuntos
Anticonvulsivantes/efeitos adversos , Desenvolvimento Infantil/efeitos dos fármacos , Desenvolvimento da Linguagem , Piracetam/análogos & derivados , Efeitos Tardios da Exposição Pré-Natal/diagnóstico , Ácido Valproico/efeitos adversos , Adulto , Anticonvulsivantes/administração & dosagem , Pré-Escolar , Epilepsia/tratamento farmacológico , Feminino , Humanos , Levetiracetam , Masculino , Piracetam/administração & dosagem , Piracetam/efeitos adversos , Gravidez , Complicações na Gravidez/diagnóstico , Complicações na Gravidez/epidemiologia , Efeitos Tardios da Exposição Pré-Natal/epidemiologia , Estudos Prospectivos , Reino Unido/epidemiologia , Ácido Valproico/administração & dosagemRESUMO
OBJECTIVES: Antiepileptic drug (AED) exposure during pregnancy increases the risk of major congenital malformations (MCMs). The magnitude of this risk varies by AED exposure. Here we provide updated results from the UK Epilepsy and Pregnancy Register of the risk of MCMs after monotherapy exposure to valproate, carbamazepine and lamotrigine. METHODS: Fifteen-year prospective observational study from 1996 until 2012. The main outcome measure is the MCM rate. RESULTS: Informative outcomes were available for 5206 cases. 1290 women were exposed to valproate monotherapy, 1718 to carbamazepine monotherapy and 2198 to lamotrigine monotherapy. The MCM risk with valproate monotherapy exposure in utero was 6.7% (95% CI 5.5% to 8.3%) compared with 2.6% with carbamazepine (95% CI 1.9% to 3.5%) and 2.3% with lamotrigine (95% CI 1.8% to 3.1%). A significant dose effect was seen with valproate (p=0.0006) and carbamazepine (p=0.03) exposed pregnancies. A non-significant trend towards higher MCM rate with increasing dose was found with lamotrigine. MCM rate for high-dose lamotrigine (>400 mg daily) was lower than the MCM rate for pregnancies exposed to <600 mg daily of valproate, but this was not significant (3.4% vs 5.0%, p=0.31). CONCLUSIONS: In utero exposure to valproate carries a significantly higher MCM risk than lamotrigine (p=0.0001) and carbamazepine (p=0.0001) monotherapy. In contrast to prior findings, high-dose lamotrigine was associated with fewer MCMs than all doses of valproate. While lamotrigine has a favourable profile compared with valproate for adverse pregnancy outcomes, the requirements for seizure control should not be overlooked.
Assuntos
Anormalidades Induzidas por Medicamentos/epidemiologia , Anticonvulsivantes/efeitos adversos , Epilepsia/tratamento farmacológico , Sistema de Registros , Adulto , Carbamazepina/efeitos adversos , Relação Dose-Resposta a Droga , Feminino , Humanos , Irlanda/epidemiologia , Lamotrigina , Gravidez , Estudos Prospectivos , Triazinas/efeitos adversos , Reino Unido/epidemiologia , Ácido Valproico/efeitos adversos , Adulto JovemRESUMO
Amyotrophic lateral sclerosis (ALS) is an adult-onset neurodegenerative disease that leads invariably to fatal paralysis associated with motor neuron degeneration and muscular atrophy. One gene associated with ALS encodes the DNA/RNA-binding protein Fused in Sarcoma (FUS). There now exist two Drosophila models of ALS. In one, human FUS with ALS-causing mutations is expressed in fly motor neurons; in the other, the gene cabeza (caz), the fly homolog of FUS, is ablated. These FUS-ALS flies exhibit larval locomotor defects indicative of neuromuscular dysfunction and early death. The locus and site of initiation of this neuromuscular dysfunction remain unclear. We show here that in FUS-ALS flies, motor neuron cell bodies fire action potentials that propagate along the axon and voltage-dependent inward and outward currents in the cell bodies are indistinguishable in wild-type and FUS-ALS motor neurons. In marked contrast, the amplitude of synaptic currents evoked in the postsynaptic muscle cell is decreased by >80% in FUS-ALS larvae. Furthermore, the frequency but not unitary amplitude of spontaneous miniature synaptic currents is decreased dramatically in FUS-ALS flies, consistent with a change in quantal content but not quantal size. Although standard confocal microscopic analysis of the larval neuromuscular junction reveals no gross abnormalities, superresolution stimulated emission depletion (STED) microscopy demonstrates that the presynaptic active zone protein bruchpilot is aberrantly organized in FUS-ALS larvae. The results are consistent with the idea that defects in presynaptic terminal structure and function precede, and may contribute to, the later motor neuron degeneration that is characteristic of ALS.
Assuntos
Esclerose Lateral Amiotrófica/patologia , Neurônios Motores/patologia , Degeneração Neural/patologia , Proteína FUS de Ligação a RNA/metabolismo , Sinapses/patologia , Esclerose Lateral Amiotrófica/genética , Esclerose Lateral Amiotrófica/metabolismo , Animais , Modelos Animais de Doenças , Drosophila , Neurônios Motores/metabolismo , Degeneração Neural/genética , Degeneração Neural/metabolismo , Proteína FUS de Ligação a RNA/genética , Sinapses/genética , Sinapses/metabolismoRESUMO
SLOB (SLOWPOKE-binding protein) modulates the Drosophila SLOWPOKE calcium-activated potassium channel. We have shown previously that SLOB deletion or RNAi knockdown decreases excitability of neurosecretory pars intercerebralis (PI) neurons in the adult Drosophila brain. In contrast, we found that SLOB deletion/knockdown enhances neurotransmitter release from motor neurons at the fly larval neuromuscular junction, suggesting an increase in excitability. Because two prominent SLOB isoforms, SLOB57 and SLOB71, modulate SLOWPOKE channels in opposite directions in vitro, we investigated whether divergent expression patterns of these two isoforms might underlie the differential modulation of excitability in PI and motor neurons. By performing detailed in vitro and in vivo analysis, we found strikingly different modes of regulatory control by the slob57 and slob71 promoters. The slob71, but not slob57, promoter contains binding sites for the Hunchback and Mirror transcriptional repressors. Furthermore, several core promoter elements that are absent in the slob57 promoter coordinately drive robust expression of a luciferase vector by the slob71 promoter in vitro. In addition, we visualized the expression patterns of the slob57 and slob71 promoters in vivo and found clear spatiotemporal differences in promoter activity. SLOB57 is expressed prominently in adult PI neurons, whereas larval motor neurons exclusively express SLOB71. In contrast, at the larval neuromuscular junction, SLOB57 expression appears to be restricted mainly to a subset of glial cells. Our results illustrate how the use of alternative transcriptional start sites within an ion channel modulator locus coupled with functionally relevant alternative splicing can be used to fine-tune neuronal excitability in a cell-specific manner.
Assuntos
Encéfalo/metabolismo , Proteínas de Drosophila/metabolismo , Neuroglia/metabolismo , Neurônios/metabolismo , Canais de Potássio/metabolismo , Isoformas de Proteínas/metabolismo , Animais , Animais Geneticamente Modificados , Drosophila , Proteínas de Drosophila/genética , Larva/genética , Larva/metabolismo , Junção Neuromuscular/genética , Junção Neuromuscular/metabolismo , Canais de Potássio/genética , Regiões Promotoras Genéticas , Isoformas de Proteínas/genética , Transmissão Sináptica/fisiologiaRESUMO
Compared to the background population, people with epilepsy tend to have lower rates of education and employment, lower rates of marriage and childbearing, and lower overall socioeconomic status (SES). Disparities in epilepsy care based on sociodemographic factors have been observed in the literature, but it is not known whether any such disparities exist in the UK. The UK Epilepsy and Pregnancy Register is a prospective, observational, registration and follow-up study that was set up to determine the relative safety of all AEDs taken in pregnancy. Here, we report outcomes of registered pregnancies to women with epilepsy living in Scotland from December 1996 to June 2012, based on the degree of socioeconomic deprivation of their postcode area. The Scottish Index of Multiple Deprivation (SIMD) quintile scores from 2006 were used to determine degree of socioeconomic deprivation, and group 1 (most deprived) and group 5 (least deprived) were compared. There were 1526 pregnancies with complete outcome data to women living in Scotland. Of these, 1453 (95.1%) resulted in a live birth and 68 (4.7%) had a major congenital malformation (MCM). Postcodes could not be reliably identified or verified for an additional three women, who have been excluded from SIMD group analysis. Of all women included in this study, 32.4% were in group 1 and 13.2% in group 5. No difference in MCM rate was observed between the two groups (4.4% in group 1 compared to 4.7% in group 5, p=0.84). Women in group 5 were more likely to take preconceptual folic acid (56.8% compared to 14.0%, relative risk: 4.1; 95% CI: 3.1-5.2) and less likely to have generalized tonic-clonic seizures in pregnancy (13.0% compared to 29.2%, relative risk: 0.4; 95% CI: 0.3-0.7) than those in group 1. Women in group 5 were more likely to be on monotherapy regimens (80.2% compared to 65.9%, relative risk: 1.2; 95% CI: 1.1-1.3), less likely to be on valproate (19.5% compared to 28.0%, p=0.05), and more likely to be on lower doses of the drug (825.9mg/day compared to 1012.0mg/day, p=0.05) compared to those in group 1. Although no change in MCM rate was seen based on SES, differences in treatment between socioeconomic groups do exist, particularly for preconceptual folic acid consumption, AED regimen, and seizure frequency. Greater emphasis on the importance of preconceptual counseling, both to discuss AED choice and folic acid intake, would be of benefit, particularly to those living in areas of high socioeconomic deprivation, to improve equity of healthcare delivery for women with epilepsy in Scotland.