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1.
Development ; 150(10)2023 05 15.
Artigo em Inglês | MEDLINE | ID: mdl-37129010

RESUMO

Nematode molting is a remarkable process where animals must repeatedly build a new apical extracellular matrix (aECM) beneath a previously built aECM that is subsequently shed. The nuclear hormone receptor NHR-23 (also known as NR1F1) is an important regulator of C. elegans molting. NHR-23 expression oscillates in the epidermal epithelium, and soma-specific NHR-23 depletion causes severe developmental delay and death. Tissue-specific RNAi suggests that nhr-23 acts primarily in seam and hypodermal cells. NHR-23 coordinates the expression of factors involved in molting, lipid transport/metabolism and remodeling of the aECM. NHR-23 depletion causes dampened expression of a nas-37 promoter reporter and a loss of reporter oscillation. The cuticle collagen ROL-6 and zona pellucida protein NOAH-1 display aberrant annular localization and severe disorganization over the seam cells after NHR-23 depletion, while the expression of the adult-specific cuticle collagen BLI-1 is diminished and frequently found in patches. Consistent with these localization defects, the cuticle barrier is severely compromised when NHR-23 is depleted. Together, this work provides insight into how NHR-23 acts in the seam and hypodermal cells to coordinate aECM regeneration during development.


Assuntos
Proteínas de Caenorhabditis elegans , Caenorhabditis elegans , Animais , Proteínas de Caenorhabditis elegans/genética , Proteínas de Caenorhabditis elegans/metabolismo , Epitélio/metabolismo , Matriz Extracelular/metabolismo , Receptores Citoplasmáticos e Nucleares/metabolismo
2.
Ann Neurol ; 94(4): 684-695, 2023 10.
Artigo em Inglês | MEDLINE | ID: mdl-37376770

RESUMO

OBJECTIVE: The purpose of this study was to characterize a metabolic brain network associated with X-linked dystonia-parkinsonism (XDP). METHODS: Thirty right-handed Filipino men with XDP (age = 44.4 ± 8.5 years) and 30 XDP-causing mutation negative healthy men from the same population (age = 37.4 ± 10.5 years) underwent [18 F]-fluorodeoxyglucose positron emission tomography. Scans were analyzed using spatial covariance mapping to identify a significant XDP-related metabolic pattern (XDPRP). Patients were rated clinically at the time of imaging according to the XDP-Movement Disorder Society of the Philippines (MDSP) scale. RESULTS: We identified a significant XDPRP topography from 15 randomly selected subjects with XDP and 15 control subjects. This pattern was characterized by bilateral metabolic reductions in caudate/putamen, frontal operculum, and cingulate cortex, with relative increases in the bilateral somatosensory cortex and cerebellar vermis. Age-corrected expression of XDPRP was significantly elevated (p < 0.0001) in XDP compared to controls in the derivation set and in the remaining 15 patients (testing set). We validated the XDPRP topography by identifying a similar pattern in the original testing set (r = 0.90, p < 0.0001; voxel-wise correlation between both patterns). Significant correlations between XDPRP expression and clinical ratings for parkinsonism-but not dystonia-were observed in both XDP groups. Further network analysis revealed abnormalities of information transfer through the XDPRP space, with loss of normal connectivity and gain of abnormal functional connections linking network nodes with outside brain regions. INTERPRETATION: XDP is associated with a characteristic metabolic network associated with abnormal functional connectivity among the basal ganglia, thalamus, motor regions, and cerebellum. Clinical signs may relate to faulty information transfer through the network to outside brain regions. ANN NEUROL 2023;94:684-695.


Assuntos
Distonia , Distúrbios Distônicos , Doenças Genéticas Ligadas ao Cromossomo X , Masculino , Humanos , Adulto , Pessoa de Meia-Idade , Distúrbios Distônicos/diagnóstico por imagem , Distúrbios Distônicos/genética , Distúrbios Distônicos/complicações , Doenças Genéticas Ligadas ao Cromossomo X/diagnóstico por imagem , Doenças Genéticas Ligadas ao Cromossomo X/genética , Distonia/diagnóstico por imagem , Distonia/genética , Biomarcadores
3.
Cereb Cortex ; 33(11): 6943-6958, 2023 05 24.
Artigo em Inglês | MEDLINE | ID: mdl-36749014

RESUMO

Primary dystonia is thought to emerge through abnormal functional relationships between basal ganglia and cerebellar motor circuits. These interactions may differ across disease subtypes and provide a novel biomarker for diagnosis and treatment. Using a network mapping algorithm based on resting-state functional MRI (rs-fMRI), a method that is readily implemented on conventional MRI scanners, we identified similar disease topographies in hereditary dystonia associated with the DYT1 or DYT6 mutations and in sporadic patients lacking these mutations. Both networks were characterized by contributions from the basal ganglia, cerebellum, thalamus, sensorimotor areas, as well as cortical association regions. Expression levels for the two networks were elevated in hereditary and sporadic dystonia, and in non-manifesting carriers of dystonia mutations. Nonetheless, the distribution of abnormal functional connections differed across groups, as did metrics of network organization and efficiency in key modules. Despite these differences, network expression correlated with dystonia motor ratings, significantly improving the accuracy of predictions based on thalamocortical tract integrity obtained with diffusion tensor MRI (DTI). Thus, in addition to providing unique information regarding the anatomy of abnormal brain circuits, rs-fMRI functional networks may provide a widely accessible method to help in the objective evaluation of new treatments for this disorder.


Assuntos
Distonia , Distúrbios Distônicos , Humanos , Distonia/diagnóstico por imagem , Distonia/genética , Distonia/patologia , Vias Neurais , Distúrbios Distônicos/diagnóstico por imagem , Distúrbios Distônicos/genética , Distúrbios Distônicos/patologia , Cerebelo , Gânglios da Base , Imageamento por Ressonância Magnética
4.
Cereb Cortex ; 33(4): 917-932, 2023 02 07.
Artigo em Inglês | MEDLINE | ID: mdl-35325051

RESUMO

Functional imaging has been used extensively to identify and validate disease-specific networks as biomarkers in neurodegenerative disorders. It is not known, however, whether the connectivity patterns in these networks differ with disease progression compared to the beneficial adaptations that may also occur over time. To distinguish the 2 responses, we focused on assortativity, the tendency for network connections to link nodes with similar properties. High assortativity is associated with unstable, inefficient flow through the network. Low assortativity, by contrast, involves more diverse connections that are also more robust and efficient. We found that in Parkinson's disease (PD), network assortativity increased over time. Assoratitivty was high in clinically aggressive genetic variants but was low for genes associated with slow progression. Dopaminergic treatment increased assortativity despite improving motor symptoms, but subthalamic gene therapy, which remodels PD networks, reduced this measure compared to sham surgery. Stereotyped changes in connectivity patterns underlie disease progression and treatment responses in PD networks.


Assuntos
Doença de Parkinson , Humanos , Doença de Parkinson/diagnóstico por imagem , Doença de Parkinson/terapia , Imageamento por Ressonância Magnética/métodos , Encéfalo , Dopamina , Progressão da Doença
5.
Hum Brain Mapp ; 44(3): 1079-1093, 2023 02 15.
Artigo em Inglês | MEDLINE | ID: mdl-36334269

RESUMO

Behavioral variant of frontotemporal dementia (bvFTD) is common among young-onset dementia patients. While bvFTD-specific multivariate metabolic brain pattern (bFDRP) has been identified previously, little is known about its temporal evolution, internal structure, effect of atrophy, and its relationship with nonspecific resting-state networks such as default mode network (DMN). In this multicenter study, we explored FDG-PET brain scans of 111 bvFTD, 26 Alzheimer's disease, 16 Creutzfeldt-Jakob's disease, 24 semantic variant primary progressive aphasia (PPA), 18 nonfluent variant PPA and 77 healthy control subjects (HC) from Slovenia, USA, and Germany. bFDRP was identified in a cohort of 20 bvFTD patients and age-matched HC using scaled subprofile model/principle component analysis and validated in three independent cohorts. It was characterized by hypometabolism in frontal cortex, insula, anterior/middle cingulate, caudate, thalamus, and temporal poles. Its expression in bvFTD patients was significantly higher compared to HC and other dementia syndromes (p < .0004), correlated with cognitive decline (p = .0001), and increased over time in longitudinal cohort (p = .0007). Analysis of internal network organization by graph-theory methods revealed prominent network disruption in bvFTD patients. We have further found a specific atrophy-related pattern grossly corresponding to bFDRP; however, its contribution to the metabolic pattern was minimal. Finally, despite the overlap between bFDRP and FDG-PET-derived DMN, we demonstrated a predominant role of the specific bFDRP. Taken together, we validated the bFDRP network as a diagnostic/prognostic biomarker specific for bvFTD, provided a unique insight into its highly reproducible internal structure, and proved that bFDRP is unaffected by structural atrophy and independent of normal resting state networks loss.


Assuntos
Doença de Alzheimer , Demência Frontotemporal , Humanos , Demência Frontotemporal/patologia , Fluordesoxiglucose F18 , Imageamento por Ressonância Magnética/métodos , Encéfalo/diagnóstico por imagem , Encéfalo/patologia , Doença de Alzheimer/patologia , Atrofia/patologia
6.
Eur J Neurol ; 30(4): 1035-1047, 2023 04.
Artigo em Inglês | MEDLINE | ID: mdl-36583625

RESUMO

BACKGROUND AND PURPOSE: Although sporadic Creutzfeldt-Jakob disease (sCJD) is a rare cause of dementia, it is critical to understand its functional networks as the prion protein spread throughout the brain may share similar mechanisms with other more common neurodegenerative disorders. In this study, the metabolic brain network associated with sCJD was investigated and its internal network organization was explored. METHODS: We explored 2-[18 F]fluoro-2-deoxy-d-glucose positron emission tomography (FDG-PET) brain scans of 29 sCJD patients, 56 normal controls (NCs) and 46 other dementia patients from two independent centers. sCJD-related pattern (CJDRP) was identified in a cohort of 16 pathologically proven sCJD patients and 16 age-matched NCs using scaled subprofile modeling/principal component analysis and was prospectively validated in an independent cohort of 13 sCJD patients and 20 NCs. The pattern's specificity was tested on other dementia patients and its clinical relevance by clinical correlations. The pattern's internal organization was further studied using graph theory methods. RESULTS: The CJDRP was characterized by relative hypometabolism in the bilateral caudate, thalami, middle and superior frontal gyri, parietal lobe and posterior cingulum in association with relative hypermetabolism in the hippocampi, parahippocampal gyri and cerebellum. The pattern's expression significantly discriminated sCJD from NCs and other dementia patients (p < 0.005; receiver operating characteristic analysis CJD vs. NCs area under the curve [AUC] 0.90-0.96, sCJD vs. Alzheimer's disease AUC 0.78, sCJD vs. behavioral variant of frontotemporal dementia AUC 0.84). The pattern's expression significantly correlated with cognitive, functional decline and disease duration. The metabolic connectivity analysis revealed inefficient information transfer with specific network reorganization. CONCLUSIONS: The CJDRP is a robust metabolic biomarker of sCJD. Due to its excellent clinical correlations it has the potential to monitor disease in emerging disease-modifying trials.


Assuntos
Síndrome de Creutzfeldt-Jakob , Humanos , Síndrome de Creutzfeldt-Jakob/patologia , Encéfalo/patologia , Tomografia por Emissão de Pósitrons , Cerebelo/metabolismo
7.
Mov Disord ; 37(11): 2247-2256, 2022 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-36054380

RESUMO

BACKGROUND: Idiopathic Parkinson's disease (iPD) is associated with two distinct brain networks, PD-related pattern (PDRP) and PD-related cognitive pattern (PDCP), which correlate respectively with motor and cognitive symptoms. The relationship between the two networks in individual patients is unclear. OBJECTIVE: To determine whether a consistent relationship exists between these networks, we measured the difference between PDRP and PDCP expression, termed delta, on an individual basis in independent populations of patients with iPD (n = 356), patients with idiopathic REM sleep behavioral disorder (iRBD) (n = 21), patients with genotypic PD (gPD) carrying GBA1 variants (n = 12) or the LRRK2-G2019S mutation (n = 14), patients with atypical parkinsonian syndromes (n = 238), and healthy control subjects (n = 95) from the United States, Slovenia, India, and South Korea. METHODS: We used [18 F]-fluorodeoxyglucose positron emission tomography and resting-state fMRI to quantify delta and to compare the measure across samples; changes in delta over time were likewise assessed in longitudinal patient samples. Lastly, we evaluated delta in prodromal individuals with iRBD and subjects with gPD. RESULTS: Delta was abnormally elevated in each of the four iPD samples (P < 0.05), as well as in the at-risk iRBD group (P < 0.05), with increasing values over time (P < 0.001). PDRP predominance was also present in gPD, with higher values in patients with GBA1 variants compared with the less aggressive LRRK2-G2019S mutation (P = 0.005). This trend was not observed in patients with atypical parkinsonian syndromes, who were accurately discriminated from iPD based on PDRP expression and delta (area under the curve = 0.85; P < 0.0001). CONCLUSIONS: PDRP predominance, quantified by delta, assays the spread of dysfunction from motor to cognitive networks in patients with PD. Delta may therefore aid in differential diagnosis and in tracking disease progression in individual patients. © 2022 International Parkinson and Movement Disorder Society.


Assuntos
Doença de Parkinson , Transtorno do Comportamento do Sono REM , Humanos , Doença de Parkinson/complicações , Doença de Parkinson/genética , Doença de Parkinson/metabolismo , Fluordesoxiglucose F18/metabolismo , Tomografia por Emissão de Pósitrons/métodos , Transtorno do Comportamento do Sono REM/complicações , Encéfalo/diagnóstico por imagem , Encéfalo/metabolismo , Redes e Vias Metabólicas , Cognição
8.
Cereb Cortex ; 31(11): 5139-5150, 2021 10 01.
Artigo em Inglês | MEDLINE | ID: mdl-34148072

RESUMO

Cognitive dysfunction in Parkinson's disease (PD) is associated with increased expression of the PD cognition-related pattern (PDCP), which overlaps with the normal default mode network (DMN). Here, we sought to determine the degree to which the former network represents loss of the latter as a manifestation of the disease process. To address this, we first analyzed metabolic images (fluorodeoxyglucose positron emission tomography [PET]) from a large PD sample with varying cognitive performance. Cognitive impairment in these patients correlated with increased PDCP expression as well as DMN loss. We next determined the spatial relationship of the 2 topographies at the subnetwork level. To this end, we analyzed resting-state functional magnetic resonance imaging (rs-fMRI) data from an independent population. This approach uncovered a significant PD cognition-related network that resembled previously identified PET- and rs-fMRI-based PDCP topographies. Further analysis revealed selective loss of the ventral DMN subnetwork (precuneus and posterior cingulate cortex) in PD, whereas the anterior and posterior components were not affected by the disease. Importantly, the PDCP also included a number of non-DMN regions such as the dorsolateral prefrontal and medial temporal cortex. The findings show that the PDCP is a reproducible cognition-related network that is topographically distinct from the normal DMN.


Assuntos
Disfunção Cognitiva , Doença de Parkinson , Encéfalo/metabolismo , Mapeamento Encefálico , Cognição , Disfunção Cognitiva/diagnóstico por imagem , Disfunção Cognitiva/etiologia , Rede de Modo Padrão , Humanos , Imageamento por Ressonância Magnética/métodos , Doença de Parkinson/complicações , Doença de Parkinson/diagnóstico por imagem , Doença de Parkinson/metabolismo
9.
Cereb Cortex ; 30(5): 2867-2878, 2020 05 14.
Artigo em Inglês | MEDLINE | ID: mdl-31813991

RESUMO

The natural history of idiopathic Parkinson's disease (PD) varies considerably across patients. While PD is generally sporadic, there are known genetic influences: the two most common, mutations in the LRRK2 or GBA1 gene, are associated with slower and more aggressive progression, respectively. Here, we applied graph theory to metabolic brain imaging to understand the effects of genotype on the organization of previously established PD-specific networks. We found that closely matched PD patient groups with the LRRK2-G2019S mutation (PD-LRRK2) or GBA1 variants (PD-GBA) expressed the same disease networks as sporadic disease (sPD), but PD-LRRK2 and PD-GBA patients exhibited abnormal increases in network connectivity that were not present in sPD. Using a community detection strategy, we found that the location and modular distribution of these connections differed strikingly across genotypes. In PD-LRRK2, connections were gained within the network core, with the formation of distinct functional pathways linking the cerebellum and putamen. In PD-GBA, by contrast, the majority of functional connections were formed outside the core, involving corticocortical pathways at the network periphery. Strategically localized connections within the core in PD-LRRK2 may maintain PD network activity at lower levels than in PD-GBA, resulting in a less aggressive clinical course.


Assuntos
Variação Genética/fisiologia , Glucosilceramidase/metabolismo , Serina-Treonina Proteína Quinase-2 com Repetições Ricas em Leucina/metabolismo , Redes e Vias Metabólicas/fisiologia , Doença de Parkinson/diagnóstico , Doença de Parkinson/metabolismo , Estudos Transversais , Feminino , Glucosilceramidase/genética , Humanos , Serina-Treonina Proteína Quinase-2 com Repetições Ricas em Leucina/genética , Masculino , Pessoa de Meia-Idade , Doença de Parkinson/genética , Tomografia por Emissão de Pósitrons/métodos
10.
Curr Opin Neurol ; 33(3): 353-361, 2020 06.
Artigo em Inglês | MEDLINE | ID: mdl-32349105

RESUMO

PURPOSE OF REVIEW: Neuropsychiatric lupus (NPSLE) comprises a disparate collection of syndromes affecting the central and peripheral nervous systems. Progress in the attribution of neuropsychiatric syndromes to SLE-related mechanisms and development of targeted treatment strategies has been impeded by a lack of objective imaging biomarkers that reflect specific neuropsychiatric syndromes and/or pathologic mechanisms. The present review addresses recent publications of neuroimaging techniques in NPSLE. RECENT FINDINGS: Imaging studies grouping all NPSLE syndromes together are unable to differentiate between NPSLE and non-NPSLE. In contrast, diffusion tensor imaging, FDG-PET, resting, and functional MRI techniques in patients with stable non-NPSLE demonstrate abnormal network structural and functional connectivity and regional brain activity in multiple cortical areas involving the limbic system, hippocampus, frontal, parietal, and temporal lobes. Some of these changes associate with impaired cognitive performance or mood disturbance, autoantibodies or inflammatory proteins. Longitudinal data suggest progression over time. DCE-MRI demonstrates increased Blood-brain barrier permeability. SUMMARY: Study design issues related to patient selection (non-NPSLE vs. NPSLE syndromes, SLE disease activity, medications) are critical for biomarker development. Regional and network structural and functional changes identified with advanced brain imaging techniques in patients with non-NPSLE may be further developed as biomarkers for cognitive and mood disorders attributable to SLE-related mechanisms.


Assuntos
Barreira Hematoencefálica/diagnóstico por imagem , Vasculite Associada ao Lúpus do Sistema Nervoso Central/diagnóstico por imagem , Neuroimagem/métodos , Autoanticorpos/imunologia , Imagem de Tensor de Difusão/métodos , Humanos , Vasculite Associada ao Lúpus do Sistema Nervoso Central/imunologia , Imageamento por Ressonância Magnética/métodos
11.
J Vet Med Educ ; 47(s1): 92-98, 2020 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-33074077

RESUMO

As part of an OIE Veterinary Education Twinning Project linking The University of Queensland, Australia and Nong Lam University, Vietnam, the limited access to animal and clinical resources was identified as an impediment to high quality veterinary education at Nong Lam University. However, student focused, simulated learning spaces, which have been widely adopted in veterinary training, are a cost-effective opportunity to provide initial clinical skills to students in countries where resourcing is constrained. In clinical skills training facilities, students use models and simulators to practice their clinical skills to develop the confidence, competence and muscle memory to enter the clinical phase of their training. While high-fidelity veterinary simulators and models are expensive, effective models for foundational clinical skills development can be built in-house for students to practice their skills authentically. This article outlines the cost effective establishment of a veterinary clinical skills training facility at Nong Lam University.


Assuntos
Competência Clínica , Educação em Veterinária , Animais , Austrália , Países em Desenvolvimento , Humanos , Estudantes
12.
Hum Brain Mapp ; 39(3): 1163-1174, 2018 03.
Artigo em Inglês | MEDLINE | ID: mdl-29214728

RESUMO

In healthy subjects, brain activation in motor regions is greater during the visual perception of "natural" target motion, which complies with the two-thirds power law, than of "unnatural" motion, which does not. It is unknown whether motion perception is normally mediated by a specific network that can be altered in the setting of disease. We used block-design functional magnetic resonance imaging and covariance analysis to identify normal network topographies activated in response to "natural" versus "unnatural" motion. A visual motion perception-related pattern (VPRP) was identified in 12 healthy subjects, characterized by covarying activation responses in the inferior parietal lobule, frontal operculum, lateral occipitotemporal cortex, amygdala, and cerebellum (Crus I). Selective VPRP activation during "natural" motion was confirmed in 12 testing scans from healthy subjects. Consistent network activation was not seen, however, in 29 patients with dystonia, a neurodevelopmental disorder in which motion perception pathways may be involved. Using diffusion tractography, we evaluated the integrity of anatomical connections between the major VPRP nodes. Indeed, fiber counts in these pathways were substantially reduced in the dystonia subjects. In aggregate, the findings associate normal motion perception with a discrete brain network which can be disrupted under pathological conditions.


Assuntos
Encéfalo/fisiopatologia , Distúrbios Distônicos/fisiopatologia , Percepção de Movimento/fisiologia , Adulto , Encéfalo/diagnóstico por imagem , Mapeamento Encefálico , Imagem de Tensor de Difusão , Distúrbios Distônicos/diagnóstico por imagem , Feminino , Humanos , Imageamento por Ressonância Magnética , Masculino , Pessoa de Meia-Idade , Vias Neurais/diagnóstico por imagem , Vias Neurais/fisiopatologia
13.
Hum Brain Mapp ; 38(2): 617-630, 2017 02.
Artigo em Inglês | MEDLINE | ID: mdl-27207613

RESUMO

Spatial covariance mapping can be used to identify and measure the activity of disease-related functional brain networks. While this approach has been widely used in the analysis of cerebral blood flow and metabolic PET scans, it is not clear whether it can be reliably applied to resting state functional MRI (rs-fMRI) data. In this study, we present a novel method based on independent component analysis (ICA) to characterize specific network topographies associated with Parkinson's disease (PD). Using rs-fMRI data from PD and healthy subjects, we used ICA with bootstrap resampling to identify a PD-related pattern that reliably discriminated the two groups. This topography, termed rs-MRI PD-related pattern (fPDRP), was similar to previously characterized disease-related patterns identified using metabolic PET imaging. Following pattern identification, we validated the fPDRP by computing its expression in rs-fMRI testing data on a prospective case basis. Indeed, significant increases in fPDRP expression were found in separate sets of PD and control subjects. In addition to providing a similar degree of group separation as PET, fPDRP values correlated with motor disability and declined toward normal with levodopa administration. Finally, we used this approach in conjunction with neuropsychological performance measures to identify a separate PD cognition-related pattern in the patients. This pattern, termed rs-fMRI PD cognition-related pattern (fPDCP), was topographically similar to its PET-derived counterpart. Subject scores for the fPDCP correlated with executive function in both training and testing data. These findings suggest that ICA can be used in conjunction with bootstrap resampling to identify and validate stable disease-related network topographies in rs-fMRI. Hum Brain Mapp 38:617-630, 2017. © 2016 Wiley Periodicals, Inc.


Assuntos
Encéfalo/diagnóstico por imagem , Imageamento por Ressonância Magnética , Vias Neurais/diagnóstico por imagem , Doença de Parkinson/diagnóstico por imagem , Doença de Parkinson/patologia , Descanso , Adulto , Idoso , Antiparkinsonianos/uso terapêutico , Encéfalo/efeitos dos fármacos , Mapeamento Encefálico , Estudos de Coortes , Feminino , Fluordesoxiglucose F18 , Humanos , Processamento de Imagem Assistida por Computador , Levodopa/uso terapêutico , Modelos Logísticos , Masculino , Pessoa de Meia-Idade , Oxigênio/sangue , Doença de Parkinson/tratamento farmacológico , Tomografia por Emissão de Pósitrons , Reprodutibilidade dos Testes
14.
Brain ; 138(Pt 12): 3598-609, 2015 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-26419798

RESUMO

Although primary dystonia is defined by its characteristic motor manifestations, non-motor signs and symptoms have increasingly been recognized in this disorder. Recent neuroimaging studies have related the motor features of primary dystonia to connectivity changes in cerebello-thalamo-cortical pathways. It is not known, however, whether the non-motor manifestations of the disorder are associated with similar circuit abnormalities. To explore this possibility, we used functional magnetic resonance imaging to study primary dystonia and healthy volunteer subjects while they performed a motion perception task in which elliptical target trajectories were visually tracked on a computer screen. Prior functional magnetic resonance imaging studies of healthy subjects performing this task have revealed selective activation of motor regions during the perception of 'natural' versus 'unnatural' motion (defined respectively as trajectories with kinematic properties that either comply with or violate the two-thirds power law of motion). Several regions with significant connectivity changes in primary dystonia were situated in proximity to normal motion perception pathways, suggesting that abnormalities of these circuits may also be present in this disorder. To determine whether activation responses to natural versus unnatural motion in primary dystonia differ from normal, we used functional magnetic resonance imaging to study 10 DYT1 dystonia and 10 healthy control subjects at rest and during the perception of 'natural' and 'unnatural' motion. Both groups exhibited significant activation changes across perceptual conditions in the cerebellum, pons, and subthalamic nucleus. The two groups differed, however, in their responses to 'natural' versus 'unnatural' motion in these regions. In healthy subjects, regional activation was greater during the perception of natural (versus unnatural) motion (P < 0.05). By contrast, in DYT1 dystonia subjects, activation was relatively greater during the perception of unnatural (versus natural) motion (P < 0.01). To explore the microstructural basis for these functional changes, the regions with significant interaction effects (i.e. those with group differences in activation across perceptual conditions) were used as seeds for tractographic analysis of diffusion tensor imaging scans acquired in the same subjects. Fibre pathways specifically connecting each of the significant functional magnetic resonance imaging clusters to the cerebellum were reconstructed. Of the various reconstructed pathways that were analysed, the ponto-cerebellar projection alone differed between groups, with reduced fibre integrity in dystonia (P < 0.001). In aggregate, the findings suggest that the normal pattern of brain activation in response to motion perception is disrupted in DYT1 dystonia. Thus, it is unlikely that the circuit changes that underlie this disorder are limited to primary sensorimotor pathways.


Assuntos
Encéfalo/patologia , Encéfalo/fisiopatologia , Distonia Muscular Deformante/patologia , Distonia Muscular Deformante/fisiopatologia , Percepção de Movimento , Adulto , Mapeamento Encefálico , Estudos de Casos e Controles , Cerebelo/fisiopatologia , Imagem de Tensor de Difusão , Feminino , Humanos , Imageamento por Ressonância Magnética , Masculino , Vias Neurais/fisiopatologia , Ponte/fisiopatologia , Núcleo Subtalâmico/fisiopatologia
15.
Cereb Cortex ; 25(9): 3086-94, 2015 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-24860017

RESUMO

Dystonia is a brain disorder characterized by abnormal involuntary movements without defining neuropathological changes. The disease is often inherited as an autosomal-dominant trait with incomplete penetrance. Individuals with dystonia, whether inherited or sporadic, exhibit striking phenotypic variability, with marked differences in the somatic distribution and severity of clinical manifestations. In the current study, we used magnetic resonance diffusion tensor imaging to identify microstructural changes associated with specific limb manifestations. Functional MRI was used to localize specific limb regions within the somatosensory cortex. Microstructural integrity was preserved when assessed in subrolandic white matter regions somatotopically related to the clinically involved limbs, but was reduced in regions linked to clinically uninvolved (asymptomatic) body areas. Clinical manifestations were greatest in subjects with relatively intact microstructure in somatotopically relevant white matter regions. Tractography revealed significant phenotype-related differences in the visualized thalamocortical tracts while corticostriatal and corticospinal pathways did not differ between groups. Cerebellothalamic microstructural abnormalities were also seen in the dystonia subjects, but these changes were associated with genotype, rather than with phenotypic variation. The findings suggest that the thalamocortical motor system is a major determinant of dystonia phenotype. This pathway may represent a novel therapeutic target for individuals with refractory limb dystonia.


Assuntos
Mapeamento Encefálico , Córtex Cerebral/patologia , Distonia/patologia , Distonia/fisiopatologia , Estatística como Assunto , Tálamo/patologia , Adulto , Análise de Variância , Córtex Cerebral/irrigação sanguínea , Imagem de Difusão por Ressonância Magnética , Feminino , Humanos , Processamento de Imagem Assistida por Computador , Imageamento por Ressonância Magnética , Masculino , Pessoa de Meia-Idade , Vias Neurais/irrigação sanguínea , Vias Neurais/fisiologia , Oxigênio/sangue , Fenótipo , Índice de Gravidade de Doença , Tálamo/irrigação sanguínea
16.
Neurobiol Dis ; 73: 399-406, 2015 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-25447231

RESUMO

TorsinA is an important protein in brain development, and plays a role in the regulation of neurite outgrowth and synaptic function. Patients with the most common form of genetic dystonia carry a mutation (DYT1) in one copy of the Tor1a gene, a 3-bp deletion, causing removal of a single glutamic acid from torsinA. Previous imaging studies have shown that abnormal cerebellar metabolism and damaged cerebello-thalamo-cortical pathway contribute to the pathophysiology of DYT1 dystonia. However, how a mutation in one copy of the Tor1a gene causes these abnormalities is not known. We studied Tor1a heterozygous knock-out mice in vivo with FDG-PET and ex vivo with diffusion tensor imaging. We found metabolic abnormalities in cerebellum, caudate-putamen, globus pallidus, sensorimotor cortex and subthalamic nucleus. We also found that FA was increased in caudate-putamen, sensorimotor cortex and brainstem. We compared our findings with a previous imaging study of the Tor1a knock-in mice. Our study suggested that having only one normal copy of Tor1a gene may be responsible for the metabolic abnormalities observed; having a copy of mutant Tor1a, on the other hand, may be responsible for white matter pathway damages seen in DYT1 dystonia subjects.


Assuntos
Imagem de Tensor de Difusão/métodos , Distonia/metabolismo , Substância Cinzenta/metabolismo , Chaperonas Moleculares/metabolismo , Tomografia por Emissão de Pósitrons/métodos , Substância Branca/metabolismo , Animais , Distonia/patologia , Fluordesoxiglucose F18 , Substância Cinzenta/patologia , Masculino , Camundongos , Camundongos Knockout , Compostos Radiofarmacêuticos , Substância Branca/patologia
17.
Bioinformatics ; 30(7): 908-14, 2014 Apr 01.
Artigo em Inglês | MEDLINE | ID: mdl-24096080

RESUMO

MOTIVATION: Epigenetic landscapes in the regulatory regions reflect binding condition of transcription factors and their co-factors. Identifying epigenetic condition and its variation is important in understanding condition-specific gene regulation. Computational approaches to explore complex multi-dimensional landscapes are needed. RESULTS: To study epigenomic condition for gene regulation, we developed a method, AWNFR, to classify epigenomic landscapes based on the detected epigenomic landscapes. Assuming mixture of Gaussians for a nucleosome, the proposed method captures the shape of histone modification and identifies potential regulatory regions in the wavelet domain. For accuracy estimation as well as enhanced computational speed, we developed a novel algorithm based on down-sampling operation and footprint in wavelet. We showed the algorithmic advantages of AWNFR using the simulated data. AWNFR identified regulatory regions more effectively and accurately than the previous approaches with the epigenome data in mouse embryonic stem cells and human lung fibroblast cells (IMR90). Based on the detected epigenomic landscapes, AWNFR classified epigenomic status and studied epigenomic codes. We studied co-occurring histone marks and showed that AWNFR captures the epigenomic variation across time. AVAILABILITY AND IMPLEMENTATION: The source code and supplemental document of AWNFR are available at http://wonk.med.upenn.edu/AWNFR.


Assuntos
Epigenômica/métodos , Algoritmos , Animais , Linhagem Celular , Análise por Conglomerados , Células-Tronco Embrionárias/metabolismo , Fibroblastos/metabolismo , Regulação da Expressão Gênica , Histonas/química , Histonas/genética , Histonas/metabolismo , Humanos , Pulmão/metabolismo , Camundongos , Design de Software
18.
Hum Brain Mapp ; 35(10): 5306-15, 2014 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-24867148

RESUMO

Obsessive-compulsive disorder (OCD) is an often severely disabling illness with onset generally in childhood or adolescence. Little is known, however, regarding the pattern of brain resting state activity in OCD early in the course of illness. We therefore examined differences in brain resting state activity in patients with pediatric OCD compared with healthy volunteers and their clinical correlates. Twenty-three pediatric OCD patients and 23 healthy volunteers (age range 9-17), matched for sex, age, handedness, and IQ completed a resting state functional magnetic resonance imaging exam at 3T. Patients completed the Children's Yale Brown Obsessive Scale. Data were decomposed into 36 functional networks using spatial group independent component analysis (ICA) and logistic regression was used to identify the components that yielded maximum group separation. Using ICA we identified three components that maximally separated the groups: a middle frontal/dorsal anterior cingulate network, an anterior/posterior cingulate network, and a visual network yielding an overall group classification of 76.1% (sensitivity = 78.3% and specificity = 73.9%). Independent component expression scores were significantly higher in patients compared with healthy volunteers in the middle frontal/dorsal anterior cingulate and the anterior/posterior cingulate networks, but lower in patients within the visual network. Higher expression scores in the anterior/posterior cingulate network correlated with greater severity of compulsions among patients. These findings implicate resting state fMRI abnormalities within the cingulate cortex and related control regions in the pathogenesis and phenomenology of OCD early in the course of the disorder and prior to extensive pharmacologic intervention.


Assuntos
Mapeamento Encefálico , Encéfalo/fisiopatologia , Transtorno Obsessivo-Compulsivo/patologia , Transtorno Obsessivo-Compulsivo/fisiopatologia , Descanso , Adolescente , Encéfalo/irrigação sanguínea , Criança , Feminino , Humanos , Processamento de Imagem Assistida por Computador , Imageamento por Ressonância Magnética , Masculino , Rede Nervosa/irrigação sanguínea , Rede Nervosa/patologia , Oxigênio/sangue , Pediatria
19.
Proc Natl Acad Sci U S A ; 108(16): 6638-43, 2011 Apr 19.
Artigo em Inglês | MEDLINE | ID: mdl-21464304

RESUMO

The factors that determine symptom penetrance in inherited disease are poorly understood. Increasingly, magnetic resonance diffusion tensor imaging (DTI) and PET are used to separate alterations in brain structure and function that are linked to disease symptomatology from those linked to gene carrier status. One example is DYT1 dystonia, a dominantly inherited movement disorder characterized by sustained muscle contractions, postures, and/or involuntary movements. This form of dystonia is caused by a 3-bp deletion (i.e., ΔE) in the TOR1A gene that encodes torsinA. Carriers of the DYT1 dystonia mutation, even if clinically nonpenetrant, exhibit abnormalities in cerebellothalamocortical (CbTC) motor pathways. However, observations in human gene carriers may be confounded by variability in genetic background and age. To address this problem, we implemented a unique multimodal imaging strategy in a congenic line of DYT1 mutant mice that contain the ΔE mutation in the endogenous mouse torsinA allele (i.e., DYT1 knock-in). Heterozygous knock-in mice and littermate controls underwent microPET followed by ex vivo high-field DTI and tractographic analysis. Mutant mice, which do not display abnormal movements, exhibited significant CbTC tract changes as well as abnormalities in brainstem regions linking cerebellar and basal ganglia motor circuits highly similar to those identified in human nonmanifesting gene carriers. Moreover, metabolic activity in the sensorimotor cortex of these animals was closely correlated with individual measures of CbTC pathway integrity. These findings further link a selective brain circuit abnormality to gene carrier status and demonstrate that DYT1 mutant torsinA has similar effects in mice and humans.


Assuntos
Encéfalo , Distonia , Vias Eferentes , Doenças Genéticas Inatas , Chaperonas Moleculares/metabolismo , Transtornos dos Movimentos , Alelos , Animais , Sequência de Bases , Encéfalo/anormalidades , Encéfalo/metabolismo , Distonia/genética , Distonia/metabolismo , Distonia/patologia , Vias Eferentes/anormalidades , Vias Eferentes/metabolismo , Técnicas de Introdução de Genes , Doenças Genéticas Inatas/genética , Doenças Genéticas Inatas/metabolismo , Doenças Genéticas Inatas/patologia , Humanos , Camundongos , Camundongos Transgênicos , Chaperonas Moleculares/genética , Transtornos dos Movimentos/genética , Transtornos dos Movimentos/metabolismo , Transtornos dos Movimentos/patologia , Deleção de Sequência
20.
Medicine (Baltimore) ; 103(19): e38084, 2024 May 10.
Artigo em Inglês | MEDLINE | ID: mdl-38728514

RESUMO

Allergic fungal rhinosinusitis (AFRS) is a subtype of chronic rhinosinusitis, characterized by excessive immune responses to environmental molds or fungi. The diagnosis and classification of AFRS into systemic and local types remain clinically challenging due to overlapping characteristics. This study investigated the prevalence of AFRS, its manifestation and associated factors in systemic and local AFRS. A total of 200 patients diagnosed with fungal rhinosinusitis underwent both skin provocation tests (SPT) and nasal provocation tests (NPT) to confirm AFRS and classify systemic and local types. Patients were considered to have AFRS if either the SPT or NPT was positive. Among these, patients with systemic AFRS were those who had a SPT positive. Local AFRS was when patients had a negative SPT and a positive NPT. Medical history, serum total IgE level, nasal endoscopy examinations, and CT scans were also recorded. Most patients were female (65.8%), with a mean age of 55.6 years (SD = 14.4). Based on the SPT and NPT results, 31% of patients (n = 62) were diagnosed with AFRS. Among these, 54.8% (n = 34) had systemic AFRS, while 45.2% (n = 28) had local AFRS. Patients with AFRS exhibited significantly higher levels of total IgE, eosinophils, and more pronounced signs and symptoms compared to those without AFRS. However, no statistically significant differences were observed between patients with systemic AFRS and those with local AFRS. AFRS was prevalent in our study. Among patients with AFRS, both systemic AFRS and local AFRS were also prevalent. While allergic indicators and clinical presentations can aid in AFRS diagnosis, minimal distinctions were observed between systemic and local AFRS. A comprehensive assessment incorporating both local and systemic allergic responses through provocation tests, such as a combination of skin and nasal tests, is imperative for optimizing AFRS diagnosis and management.


Assuntos
Rinite Alérgica , Sinusite , Testes Cutâneos , Humanos , Feminino , Masculino , Sinusite/imunologia , Sinusite/microbiologia , Sinusite/complicações , Sinusite/epidemiologia , Sinusite/diagnóstico , Pessoa de Meia-Idade , Rinite Alérgica/imunologia , Rinite Alérgica/epidemiologia , Rinite Alérgica/complicações , Rinite Alérgica/diagnóstico , Adulto , Idoso , Testes de Provocação Nasal , Imunoglobulina E/sangue , Prevalência , Micoses/imunologia , Micoses/epidemiologia , Micoses/diagnóstico , Micoses/complicações , Sinusite Fúngica Alérgica
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