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1.
Plant Physiol ; 2022 Mar 15.
Artigo em Inglês | MEDLINE | ID: mdl-35289870

RESUMO

Red foliated cotton is a typical dominant mutation trait in upland cotton (Gossypium hirsutum). Although mutants have been described, few responsible genes have been identified and characterized. In this study, we performed map-based cloning of the red foliated mutant gene (Re) derived from the cross between Gossypium hirsutum cv. Emian22 and G. barbadense acc. 3-79. Through expression profiling, metabolic pathway analysis and sequencing of candidate genes, Re was identified as a MYB113 transcription factor. A repeat sequence variation in the promoter region increased the activity of the promoter, which enhanced the expression of Re. Re expression driven by the 35S promoter produced a red foliated phenotype, as expected. When the gene was driven by a fiber elongation-specific promoter, promoter of α-expansin 2 (PGbEXPA2), Re was specifically expressed in 5-10 days post-anthesis (DPA) fibers rather than in other tissues, resulting in brown mature fibers. Re responded to light through phytochrome-interacting factor 4 (PIF4) and formed a dimer with transparent testa 8 (TT8), which increased its expression as well as that of anthocyanin synthase (ANS) and UDP-glucose:flavonoid 3-o-glucosyl transferase (UFGT), and thus activated the entire anthocyanin metabolism pathway. Our research has identified the red foliated mutant gene in cotton, which paves the way for detailed studies of anthocyanin and proanthocyanidin metabolism and pigment accumulation in cotton and provides an alternative strategy for producing brown fiber.

2.
J Clin Psychiatry ; 83(2)2022 02 08.
Artigo em Inglês | MEDLINE | ID: mdl-35143123

RESUMO

Background: Prospective memory (PM) impairment is associated with impaired social functioning, but evidence is limited to chronic schizophrenia samples and cross-sectional design. The aim of this study was to utilize network analysis to address the complex interplay between PM, psychopathology, and functional outcome.Methods: This longitudinal study recruited 119 people with first-episode DSM-IV schizophrenia and followed up with them for 2 to 6 years. PM and working memory were assessed at baseline (in 2010-2015) using valid computerized tasks and the Letter-Number Span Test, respectively. Psychopathology and social functioning were assessed at endpoint (in 2016-2017) using the Positive and Negative Syndrome Scale (PANSS) and the Social and Occupational Functioning Assessment Scale (SOFAS), respectively. Network analysis examined the effect of baseline PM on SOFAS while accounting for the effects of psychopathology.Results: The resultant network showed that social functioning, PANSS positive symptoms, and PANSS general symptoms clustered together, whereas time-based and event-based PM and working memory formed another cluster. Time-based PM linked event-based PM and working memory with social functioning. Time-based PM (expected influence [EI] = 0.69), event-based PM (EI = 0.65), and working memory (EI = 0.83) demonstrated high values of expected influence, but social functioning (variance explained = 0.685) and PANSS negative (variance explained = 0.657) and general (variance explained = 0.583) subscales demonstrated high values of predictability.Conclusions: Time-based PM is the central node linking neurocognitive functions with social functioning. PM and working memory are "target" nodes for interventions bringing changes to the network, whereas social functioning and psychopathology are "malleable" nodes. PM and working memory are promising intervention targets for functional recovery in schizophrenia.


Assuntos
Memória Episódica , Psicologia do Esquizofrênico , Interação Social , Adulto , Feminino , Hong Kong , Humanos , Estudos Longitudinais , Masculino , Memória de Curto Prazo , Modelos Psicológicos , Testes Neuropsicológicos , Gravidez , Esquizofrenia/diagnóstico
3.
J Alzheimers Dis ; 86(2): 741-751, 2022.
Artigo em Inglês | MEDLINE | ID: mdl-35124653

RESUMO

BACKGROUND: Vascular pathology is an important partner of Alzheimer's disease (AD). Both total cerebral small vessel disease (CSVD) score and white matter free water (FW) are useful markers that could reflect cerebral vascular injury. OBJECTIVE: We aim to investigate the efficacy of these two metrics in predicting cognitive declines in patients with mild cognitive impairment (MCI). METHODS: We enrolled 126 MCI subjects with 3D T1-weighted images, fluid-attenuated inversion recovery images, T2* images, diffusion tensor imaging images, cerebrospinal fluid biomarkers and neuropsychological tests from the Alzheimer's Disease Neuroimaging Initiative database. The total CSVD score and FW values were calculated. Simple and multiple linear regression analyses were applied to explore the association between vascular and cognitive impairments. Linear mixed effect models were constructed to investigate the efficacy of total CSVD score and FW on predicting cognitive decline. RESULTS: FW was associated with baseline cognition and could predict the decline of executive and language functions in MCI subjects, while no association was found between total CSVD score and cognitive declines. CONCLUSION: FW is a promising imaging marker for investigating the effect of CSVD on AD progression.


Assuntos
Doença de Alzheimer , Doenças de Pequenos Vasos Cerebrais , Disfunção Cognitiva , Substância Branca , Doença de Alzheimer/patologia , Biomarcadores , Doenças de Pequenos Vasos Cerebrais/complicações , Doenças de Pequenos Vasos Cerebrais/diagnóstico por imagem , Doenças de Pequenos Vasos Cerebrais/patologia , Disfunção Cognitiva/psicologia , Imagem de Tensor de Difusão , Humanos , Imageamento por Ressonância Magnética , Testes Neuropsicológicos , Água , Substância Branca/diagnóstico por imagem , Substância Branca/patologia
4.
Psych J ; 2022 Jan 17.
Artigo em Inglês | MEDLINE | ID: mdl-35037406

RESUMO

It is important for positive well-being and social engagement to understand how people predict future emotions, an ability known as affective forecasting. However, mechanisms underpinning the change to affective forecasting are not well understood in people with subclinical psychiatric symptoms. The current study differentiated components that comprise affective forecasting and investigated how non-clinical features relate to these. We recruited 319 participants to complete the social affective forecasting task and respond to questionnaires that captured schizotypal and autistic traits as well as depressive symptoms. Associations between affective forecasting and subclinical features were investigated using correlations, regression, and structure equation modeling. Results showed that interpersonal features of schizotypal traits negatively predicted anticipated emotions in positive social conditions via in-the-moment feelings but not via mental simulation. Findings highlight that in-the-moment feelings may be an intervention target to help people who have difficulties with social interactions to anticipate more pleasure for future social events.

5.
Asia Pac J Clin Oncol ; 18(2): e173-e181, 2022 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-34541812

RESUMO

BACKGROUND AND PURPOSE: To investigate the prognostic value of retropharyngeal lymphadenopathy in nasopharyngeal carcinoma (NPC) after intensity-modulated radiotherapy. MATERIALS AND METHODS: Retrospective studies were performed in a total of 1197 patients. We evaluated the incidence of the retropharyngeal node (RPN) metastasis and the characteristics of the metastatic RPN including laterality, size, necrosis, and extranodal neoplastic spread. RESULTS: RPN metastasis occured in 86.3% of patients. The RPN and level II metastasis shared similar survival outcomes. RPN metastasis was an independent prognostic factor for distant failure (hazard ratio = 1.615; 95% confidence interval, 1.063-2.452; P = 0.025), in which the laterality of RPN metastasis significantly influences both the distant failure (P = 0.006) and disease progression (P = 0.001). In N1 disease, the occurrence of unilateral and bilateral RPN metastasis resulted in significantly different outcomes of the disease-specific survival (P = 0.045) and progression-free survival (P = 0.049). The co-occurrence of bilateral RPN and cervical lymph nodes (CLN) metastasis was an independent adverse prognostic factor (P < 0.01) for distant failure and disease progression but not for locoregional recurrence. CONCLUSION: Both the RPN and level II are the first stations of NPC lymph node metastasis. For N1-stage NPC patients, RPN metastasis, especially co-occurrence of bilateral RPN and CLN metastasis, have an adverse influence on survival outcomes.


Assuntos
Carcinoma , Neoplasias Nasofaríngeas , Radioterapia de Intensidade Modulada , Carcinoma/patologia , Progressão da Doença , Humanos , Linfonodos/patologia , Imageamento por Ressonância Magnética/métodos , Carcinoma Nasofaríngeo/radioterapia , Neoplasias Nasofaríngeas/patologia , Recidiva Local de Neoplasia/patologia , Recidiva Local de Neoplasia/radioterapia , Estadiamento de Neoplasias , Prognóstico , Radioterapia de Intensidade Modulada/métodos , Estudos Retrospectivos
6.
Transl Stroke Res ; 13(1): 56-64, 2022 02.
Artigo em Inglês | MEDLINE | ID: mdl-33634379

RESUMO

To investigate the association between white matter free water (FW) and common imaging markers of cerebral small vessel diseases (CSVD) in two groups of subjects with different clinical status. One hundred and forty-four community subjects (mean age 60.5) and 84 CSVD subjects (mean age 61.2) were retrospectively included in the present study. All subjects received multi-modal magnetic resonance imaging and clinical assessments. The association between white matter FW and common CSVD imaging markers, including white matter hyperintensities (WMH), dilated perivascular space (PVS), lacunes, and microbleeds, were assessed using simple and multiple regression analysis. The association between FW and cognitive scores were also investigated. White matter FW was positively associated with WMH volume (ß = 0.270, p = 0.001), PVS volume (ß = 0.290, p < 0.001), number of microbleeds (ß = 0.148, p = 0.043), and age (ß = 0.170, p = 0.036) in the community cohort. In the CSVD cohort, FW was positively associated with WMH volume (ß = 0.648, p < 0.001), PVS score (ß = 0.224, p < 0.001), number of lacunes (ß = 0.140, p = 0.046), and sex (ß = 0.125, p = 0.036). The associations between FW and cognitive scores were stronger than conventional CSVD markers in both datasets. White matter FW is a potential composite marker that can sensitively detect cerebral small vessel degeneration and also reflect cognitive impairments.


Assuntos
Doenças de Pequenos Vasos Cerebrais , Doenças Neurodegenerativas , Substância Branca , Biomarcadores , Hemorragia Cerebral/patologia , Doenças de Pequenos Vasos Cerebrais/complicações , Humanos , Imageamento por Ressonância Magnética , Pessoa de Meia-Idade , Estudos Retrospectivos , Água , Substância Branca/diagnóstico por imagem , Substância Branca/patologia
7.
Psychol Med ; 52(5): 834-843, 2022 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-32677599

RESUMO

BACKGROUND: Schizotypy refers to schizophrenia-like traits below the clinical threshold in the general population. The pathological development of schizophrenia has been postulated to evolve from the initial coexistence of 'brain disconnection' and 'brain connectivity compensation' to 'brain connectivity decompensation'. METHODS: In this study, we examined the brain connectivity changes associated with schizotypy by combining brain white matter structural connectivity, static and dynamic functional connectivity analysis of diffusion tensor imaging data and resting-state functional magnetic resonance imaging data. A total of 87 participants with a high level of schizotypal traits and 122 control participants completed the experiment. Group differences in whole-brain white matter structural connectivity probability, static mean functional connectivity strength, dynamic functional connectivity variability and stability among 264 brain sub-regions of interests were investigated. RESULTS: We found that individuals with high schizotypy exhibited increased structural connectivity probability within the task control network and within the default mode network; increased variability and decreased stability of functional connectivity within the default mode network and between the auditory network and the subcortical network; and decreased static mean functional connectivity strength mainly associated with the sensorimotor network, the default mode network and the task control network. CONCLUSIONS: These findings highlight the specific changes in brain connectivity associated with schizotypy and indicate that both decompensatory and compensatory changes in structural connectivity within the default mode network and the task control network in the context of whole-brain functional disconnection may be an important neurobiological correlate in individuals with high schizotypy.


Assuntos
Transtorno da Personalidade Esquizotípica , Substância Branca , Encéfalo , Mapeamento Encefálico , Imagem de Tensor de Difusão , Humanos , Imageamento por Ressonância Magnética
8.
Psych J ; 11(2): 232-234, 2022 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-33783123

RESUMO

This study constructed the network structure of social anhedonia, emotion processing, and executive function in college students using network analysis. We calculated the strength of each node in the network. The results suggest that social anhedonia had negative effects on executive function, emotion experience, and emotion expression.


Assuntos
Anedonia , Função Executiva , Emoções , Humanos , Estudantes
9.
J Abnorm Psychol ; 130(8): 807-814, 2021 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-34843287

RESUMO

Prospection refers to the ability to mentally construct future events, which is closely related to motivation and anhedonia. The neural underpinning of impaired prospection in psychiatric populations remains unclear. We recruited 34 individuals with autistic traits (AT), 27 individuals with schizotypal traits (ST), 31 individuals with depressive symptoms (DS), and 35 controls. Participants completed a prospection task while undergoing functional Magnetic Resonance Imaging (MRI). We found that regions of the "default mode network" including the medial frontal gyrus, the posterior cingulate cortex, the precuneus and the parahippocampus were activated; and regions of the "task-positive network" including the inferior parietal lobe, the inferior frontal gyrus and the precentral gyrus were deactivated during prospection in controls. Compared with controls, AT, ST, and DS showed comparable behavioral performance on prospection. However, reduced activation in anterior cingulate cortex and frontal gyrus was found in AT individuals relative to controls during prospection. ST individuals showed hyperactivation in the caudate relative to controls when processing positive emotion, while DS individuals and controls showed similar neural responses during prospection. (PsycInfo Database Record (c) 2021 APA, all rights reserved).


Assuntos
Transtorno Autístico , Encéfalo/diagnóstico por imagem , Mapeamento Encefálico , Depressão , Giro do Cíngulo , Humanos , Imageamento por Ressonância Magnética , Lobo Parietal
10.
Psychiatry Res Neuroimaging ; 317: 111390, 2021 11 30.
Artigo em Inglês | MEDLINE | ID: mdl-34537603

RESUMO

Social anhedonia (SA) impairs social functioning in schizophrenia. Previous evidence suggested that certain brain regions predict longitudinal change of real-world social outcomes, yet previous study designs have failed to capture the corresponding functional connectivity among the brain regions involved. This study measured the real-world social network in 22 pairs of individuals with high and low levels of SA, and followed up them for 21 months. We further explored whether resting-state social brain network characteristics could predict the longitudinal variations of real-world social network. Our results showed that social brain network characteristics could predict the change of real-world social networks in both the high SA and low SA groups. However, the results differed between the two groups, i.e., the topological characteristics of the social brain network predicted real-world social network change in the high SA group; whereas the functional connectivity within the social brain network predicted real-world social network change in the low SA group. Principal component analysis and linear regression analysis on the entire sample showed that the functional connectivity component centered at the right orbital inferior frontal gyrus could best predict social network change. Our findings support the notion that social brain network characteristics could predict social network development.


Assuntos
Anedonia , Esquizofrenia , Encéfalo/diagnóstico por imagem , Humanos , Imageamento por Ressonância Magnética , Esquizofrenia/diagnóstico por imagem , Rede Social
11.
Front Aging Neurosci ; 13: 693787, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-34349635

RESUMO

Assessing glymphatic function using in-vivo imaging method is of great value for understanding its contribution to major brain diseases. In the present study, we aim to validate the association between a variety of risk factors and a potential index of glymphatic function-Diffusion Tensor Image Analysis Along the Perivascular Space (ALPS index). We enrolled 142 subjects from communities and performed multi-modality magnetic resonance imaging scans. The ALPS index was calculated from diffusion tensor imaging data, and its associations with demographic factors, vascular factors were investigated using regression analyses. We found that the ALPS index was negatively associated with age (ß = -0.284, p < 0.001). Compared to males, females had significantly higher ALPS index (ß = -0.243, p = 0.001). Hypertensive subjects had significantly lower ALPS index compared to non-hypertensive subjects (ß = -0.189, p = 0.013). Furthermore, venous disruption could decrease ALPS index (ß = -0.215, p = 0.003). In general, our results are in consistent with previous conceptions and results from animal studies about the pathophysiology of glymphatic dysfunction. Future studies utilizing this method should consider introducing the above-mentioned factors as important covariates.

12.
Front Aging Neurosci ; 13: 685571, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-34239436

RESUMO

Lenticulostriate arteries (LSAs) supply blood to important subcortical areas and are, therefore, essential for maintaining the optimal functioning of the brain's most metabolically active nuclei. Past studies have demonstrated the potential for quantifying the morphology of LSAs as biomarkers of vascular fragility or underlying arteriopathies. Thus, the current study aims to evaluate the morphological features of LSAs, their potential value in cerebrovascular risk stratification, and their concordance with other vascular risk factors in community-dwelling elderly people. A total of 125 community-dwelling elderly subjects who underwent a brain MRI scan were selected from our prospectively collected imaging database. The morphological measures of LSAs were calculated on the vascular skeletons obtained by manual tracing, and the number of LSAs was counted. Additionally, imaging biomarkers of small vessel disease were evaluated, and the diameters of major cerebral arteries were measured. The effects of vascular risk factors on LSA morphometry, as well as the relationship between LSA measures and other imaging biomarkers, were investigated. We found that smokers had shorter (p = 0.04) and straighter LSAs (p < 0.01) compared to nonsmokers, and the presence of hypertension is associated with less tortuous LSAs (p = 0.03) in community-dwelling elderly. Moreover, the middle cerebral artery diameter was positively correlated with LSA count (r = 0.278, p = 0.025) and vessel tortuosity (r = 0.257, p = 0.04). The posterior cerebral artery diameter was positively correlated with vessel tortuosity and vessel length. Considering the scarcity of noninvasive methods for measuring small artery abnormalities in the brain, the LSA morphological measures may provide valuable information to better understand cerebral small vessel degeneration during aging.

13.
Fluids Barriers CNS ; 18(1): 29, 2021 Jun 30.
Artigo em Inglês | MEDLINE | ID: mdl-34193191

RESUMO

BACKGROUND: White matter hyperintensities (WMHs) are one of the hallmarks of cerebral small vessel disease (CSVD), but the pathological mechanisms underlying WMHs remain unclear. Recent studies suggest that extracellular fluid (ECF) is increased in brain regions with WMHs. It has been hypothesized that ECF accumulation may have detrimental effects on white matter microstructure. To test this hypothesis, we used cerebral autosomal-dominant arteriopathy with subcortical infarcts and leukoencephalopathy (CADASIL) as a unique CSVD model to investigate the relationships between ECF and fiber microstructural changes in WMHs. METHODS: Thirty-eight CADASIL patients underwent 3.0 T MRI with multi-model sequences. Parameters of free water (FW) and apparent fiber density (AFD) obtained from diffusion-weighted imaging (b = 0 and 1000 s/mm2) were respectively used to quantify the ECF and fiber density. WMHs were split into four subregions with four levels of FW using quartiles (FWq1 to FWq4) for each participant. We analyzed the relationships between FW and AFD in each subregion of WMHs. Additionally, we tested whether FW of WMHs were associated with other accompanied CSVD imaging markers including lacunes and microbleeds. RESULTS: We found an inverse correlation between FW and AFD in WMHs. Subregions of WMHs with high-level of FW (FWq3 and FWq4) were accompanied with decreased AFD and with changes in FW-corrected diffusion tensor imaging parameters. Furthermore, FW was also independently associated with lacunes and microbleeds. CONCLUSIONS: Our study demonstrated that increased ECF was associated with WM degeneration and the occurrence of lacunes and microbleeds, providing important new insights into the role of ECF in CADASIL pathology. Improving ECF drainage might become a therapeutic strategy in future.


Assuntos
CADASIL/diagnóstico por imagem , Imagem de Difusão por Ressonância Magnética/métodos , Líquido Extracelular/diagnóstico por imagem , Degeneração Neural/diagnóstico por imagem , Fibras Nervosas Mielinizadas , Substância Branca/diagnóstico por imagem , Adulto , CADASIL/metabolismo , Estudos Transversais , Líquido Extracelular/metabolismo , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Degeneração Neural/metabolismo , Fibras Nervosas Mielinizadas/metabolismo , Substância Branca/metabolismo
14.
Schizophr Res ; 232: 77-84, 2021 06.
Artigo em Inglês | MEDLINE | ID: mdl-34044349

RESUMO

Social behaviour requires the brain to efficiently integrate multiple social processes, but it is not clear what neural substrates underlie general social behaviour. While psychosis patients and individuals with subclinical symptoms are characterized by social dysfunction, the neural mechanisms underlying social dysfunctions in schizophrenia spectrum disorders remains unclear. We first constructed a general social brain network (SBN) using resting-state functional connectivity (FC) with regions of interest based on the automatic meta-analysis results from NeuroSynth. We then examined the general SBN and its relationship with social network (SN) characteristics in 30 individuals with schizophrenia (SCZ) and 33 individuals with social anhedonia (SA). We found that patients with SCZ exhibited deficits in their SN, while SA individuals did not. SCZ patients showed decreased segregation and functional connectivity in their SBN, while SA individuals showed a reversed pattern with increased segregation and functional connectivity of their SBN. Sparse canonical correlation analysis showed that both SCZ patients and SA individuals exhibited reduced correlation between SBN and SN characteristics compared with their corresponding healthy control groups. These preliminary findings suggest that both SCZ and SA participants exhibit abnormality in segregation and functional connectivity within the general SBN and reduced correlation with SN characteristics. These findings could guide the development of non-pharmacological interventions for social dysfunction in SCZ spectrum disorders.


Assuntos
Esquizofrenia , Anedonia , Encéfalo/diagnóstico por imagem , Humanos , Imageamento por Ressonância Magnética , Rede Social
15.
Front Aging Neurosci ; 13: 591347, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-33994988

RESUMO

BACKGROUND: Apolipoprotein E (APOE) ε2 is a protective genetic factor for Alzheimer's disease (AD). However, the potential interaction effects between the APOE ε2 allele and disease status on the intrinsic brain activity remain elusive. METHODS: We identified 73 healthy control (HC) with APOE ε3/ε3, 61 mild cognitive impairment (MCI) subjects with APOE ε3/ε3, 24 HC with APOE ε2/ε3, and 10 MCI subjects with APOE ε2/ε3 from the ADNI database. All subjects underwent a resting-state functional MRI and Fluoro-deoxy-glucose positron emission tomography (FDG-PET). We used a fractional amplitude of low-frequency fluctuation (fALFF) to explore the spontaneous brain activity. Based on the mixed-effects analysis, we explored the interaction effects between the APOE ε2 allele versus disease status on brain activity and metabolism in a voxel-wise fashion (GRF corrected, p < 0.01), followed by post hoc two-sample t-tests (Bonferroni corrected, p < 0.05). We then investigated the relationship between the mean imaging metrics and cognitive abilities. RESULTS: There are no significant differences in gender, age, or education among the four groups. The interaction effect on brain activity was located in the inferior parietal lobule (IPL). Post hoc analysis showed that APOE ε2/ε3 MCI had an increased IPL fALFF than APOE ε3/ε3 MCI. Regarding the APOE ε2 allele effects, we found that ε2 carriers had a decreased fALFF in the transverse temporal gyrus than non-carriers. Also, FDG-PET results showed a lower SUVR of the frontal lobe in APOE ε2 carriers than non-carriers. Furthermore, fALFF of IPL was correlated with the visuospatial function (r = -0.16, p < 0.05). CONCLUSION: APOE ε2 carriers might have a better brain reservation when coping with AD-related pathologies.

16.
Quant Imaging Med Surg ; 11(5): 2114-2124, 2021 May.
Artigo em Inglês | MEDLINE | ID: mdl-33936992

RESUMO

BACKGROUND: Although lacunar infarcts are focal lesions, they may also have more widespread effects. A reduction in cortical thickness in the remote cortex after lacunar infarcts has been detected by structural imaging; however, its underlying microstructural changes are yet to be elucidated. This study aimed to investigate the effects of lacunar infarcts on the microstructural abnormalities associated with cortical thickness reduction in the remote cortex. METHODS: Thirty-seven patients with chronic lacunar infarcts were included. Brain structural magnetic resonance images (MRIs) and diffusion tensor images were acquired. We constructed the white matter tracts connecting with the lacunar infarcts and identified the connected cortical area based on a standard brain atlas warped into the subject space. Cortical thickness and microstructural neurite orientation dispersion and density imaging (NODDI) metrics of the ipsilesional and contralesional cortices were compared, and correlations between cortical thickness and NODDI metrics were also investigated. RESULTS: We found decreased cortical thickness and reduced neurite orientation dispersion index (ODI) in the ipsilesional cortex (2.47 vs. 2.50 mm, P=0.008; 0.451 vs. 0.456, P=0.035, respectively). In patients with precentral gyrus involvement (n=23), we found that ODI in the ipsilesional cortex was correlated with cortical thickness (r=0.437, P=0.037), and ODI in the contralesional cortex was also correlated with contralesional cortical thickness (r=0.440, P=0.036). CONCLUSIONS: NODDI metrics could reflect cortical microstructural changes following lacunar infarcts. The correlation between decreased ODI and reduced cortical thickness suggests that dendrites' loss might contribute to lacunar infarct-related cortical atrophy.

17.
J Magn Reson Imaging ; 54(4): 1326-1336, 2021 10.
Artigo em Inglês | MEDLINE | ID: mdl-33998738

RESUMO

BACKGROUND: Perivascular spaces (PVSs) are important component of the brain glymphatic system. While visual rating has been widely used to assess PVS, computational measures may have higher sensitivity for capturing PVS characteristics under disease conditions. PURPOSE: To compute quantitative and morphological PVS features and to assess their associations with vascular risk factors and cerebral small vessel disease (CSVD). STUDY TYPE: Prospective. POPULATION: One hundred sixty-one middle-aged/later middle-aged subjects (age = 60.4 ± 7.3). SEQUENCE: 3D T1-weighted, T2-weighted and T2-FLAIR sequences, and susceptibility-weighted multiecho gradient-echo sequence on a 3 T scanner. ASSESSMENT: Automated PVS segmentation was performed on sub-millimeter T2-weighted images. Quantitative and morphological PVS features were calculated in white matter (WM) and basal ganglia (BG) regions, including volume, count, size, length (Lmaj ), width (Lmin ), and linearity. Visual PVS scores were also acquired for comparison. STATISTICAL TESTS: Simple and multiple linear regression analyses were used to explore the associations among variables. RESULTS: WM-PVS visual score and count were associated with hypertension (ß = 0.161, P < 0.05; ß = 0.193, P < 0.05), as were BG-PVS rating score, volume, count and Lmin (ß = 0.197, P < 0.05; ß = 0.170, P < 0.05; ß = 0.200, P < 0.05; ß = 0.172, P < 0.05). WM-PVS size was associated with diabetes (ß = 0.165, P < 0.05). WM-PVS and BG-PVS were associated with CSVD markers, especially white matter hyperintensities (WMHs) (P < 0.05). Multiple regression analysis showed that WM/BG-PVS quantitative measures were widely associated with vascular risk factors and CSVD markers (P < 0.05). Morphological measures were associated with WMH severity in WM region and also associated with lacunes and microbleeds (P < 0.05) in BG region. DATA CONCLUSION: These novel PVS measures may capture mild PVS alterations driven by different pathologies. EVIDENCE LEVEL: 2 TECHNICAL EFFICACY: Stage 2.


Assuntos
Doenças de Pequenos Vasos Cerebrais , Substância Branca , Idoso , Doenças de Pequenos Vasos Cerebrais/diagnóstico por imagem , Humanos , Imageamento por Ressonância Magnética , Pessoa de Meia-Idade , Estudos Prospectivos , Fatores de Risco , Substância Branca/diagnóstico por imagem
18.
Aging (Albany NY) ; 13(9): 12410-12430, 2021 04 30.
Artigo em Inglês | MEDLINE | ID: mdl-33930871

RESUMO

BACKGROUND: The underlying white matter impairment in patients with early and late-onset Alzheimer's disease (EOAD and LOAD) is still unclear, and this might due to the complex AD pathology. METHODS: We included 31 EOAD, 45 LOAD, and 64 younger, 46 elder controls in our study to undergo MRI examinations. Fiber density (FD) and fiber bundle cross-section (FC) were measured using fixel-based analysis based on diffusion weighted images. On whole brain and tract-based level, we compared these parameters among different groups (p<0.05, FWE corrected). Moreover, we verified our results in another independent dataset using the same analyses. RESULTS: Compared to young healthy controls, EOAD had significantly lower FD in the splenium of corpus callosum, limbic tracts, cingulum bundles, and posterior thalamic radiation, and higher FC in the splenium of corpus callosum, dorsal cingulum and posterior thalamic radiation. On the other hand, LOAD had lower FD and FC as well. Importantly, a similar pattern was found in the independent validation dataset. Among all groups, both the FD and FC were associated with cognitive function. Furthermore, FD of fornix column and body, and FC of ventral cingulum were associated with composite amyloid and tau level (r=-0.34 and -0.53, p<0.001) respectively. CONCLUSIONS: EOAD and LOAD were characterized by distinct white matter impairment patterns, which may be attributable to their different neuropathologies.


Assuntos
Doença de Alzheimer/patologia , Imagem de Difusão por Ressonância Magnética , Progressão da Doença , Placa Amiloide/patologia , Substância Branca/patologia , Idade de Início , Idoso , Encéfalo/patologia , Imagem de Difusão por Ressonância Magnética/métodos , Imagem de Tensor de Difusão/métodos , Feminino , Humanos , Imageamento por Ressonância Magnética/métodos , Masculino , Pessoa de Meia-Idade
19.
Front Aging Neurosci ; 13: 624732, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-33841126

RESUMO

Background: The dilation of perivascular space (PVS) has been widely used to reflect brain degeneration in clinical brain imaging studies. However, PVS characteristics exhibit large differences in healthy subjects. Such variations need to be better addressed before PVS can be used to reflect pathological changes. In the present study, we aim to investigate the potential influence of several related factors on PVS dilation in healthy elderly subjects. Methods: One-hundred and three subjects (mean age = 59.5) were retrospectively included from a prospectively collected community cohort. Multi-modal high-resolution magnetic resonance imaging and cognitive assessments were performed on each subject. Machine-learning based segmentation methods were employed to quantify PVS volume and white matter hyperintensity (WMH) volume. Multiple regression analysis was performed to reveal the influence of demographic factors, vascular risk factors, intracranial volume (ICV), major brain artery diameters, and brain atrophy on PVS dilation. Results: Multiple regression analysis showed that age was positively associated with the basal ganglia (BG) (standardized beta = 0.227, p = 0.027) and deep white matter (standardized beta = 0.220, p = 0.029) PVS volume. Hypertension was positively associated with deep white matter PVS volume (standardized beta = 0.234, p = 0.017). Furthermore, we found that ICV was strongly associated with the deep white matter PVS volume (standardized beta = 0.354, p < 0.001) while the intracranial artery diameter was negatively associated with the deep white matter PVS volume (standardized beta = -0.213, p = 0.032). Conclusions: Intracranial volume has significant influence on deep white matter PVS volume. Future studies on PVS dilation should include ICV as an important covariate.

20.
J Cereb Blood Flow Metab ; 41(9): 2370-2380, 2021 09.
Artigo em Inglês | MEDLINE | ID: mdl-33757317

RESUMO

Understanding the pathophysiology of white matter hyperintensity (WMH) is necessary to reduce its harmfulness. Dilated perivascular space (PVS) had been found related to WMH. In the present study, we aimed to examine the topological connections between WMH and PVS, and to investigate whether increased interstitial fluid mediates the correlation between PVS and WMH volumes. One hundred and thirty-six healthy elder subjects were retrospectively included from a prospectively collected community cohort. Sub-millimeter T2 weighted and FLAIR images were acquired for assessing the association between PVS and WMH. Diffusion tensor imaging and free-water (FW) analytical methods were used to quantify white matter free water content, and to explore whether it mediates the PVS-WMH association. We found that most (89%) of the deep WMH lesions were spatially connected with PVS, exhibiting several interesting topological types. PVS and WMH volumes were also significantly correlated (r = 0.222, p < 0.001). FW mediated this association in the whole sample (ß = 0.069, p = 0.037) and in subjects with relatively high WMH load (ß = 0.118, p = 0.006). These findings suggest a tight association between PVS dilation and WMH formation, which might be linked by the impaired glymphatic drainage function and accumulated local interstitial fluid.


Assuntos
Encéfalo/fisiopatologia , Sistema Glinfático/fisiopatologia , Imageamento por Ressonância Magnética/métodos , Substância Branca/patologia , Idoso , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Estudos Prospectivos
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