Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 88
Filtrar
Más filtros

Bases de datos
Tipo del documento
Intervalo de año de publicación
1.
Invest New Drugs ; 42(2): 196-206, 2024 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-38386170

RESUMEN

Patients with metastatic lung adenocarcinoma (MLA) and malignant pleural effusion (MPE) without driver gene mutations have a poor prognosis. None of the standard treatment strategies is recommended for such patients. We retrospectively analyzed the efficacy of the first-line treatment for this specific population: standard platinum-based doublet chemotherapy (CT), CT plus an immune checkpoint inhibitor (CT plus ICI), and CT plus bevacizumab (CT plus Bev). A total of 323 eligible patients were enrolled: CT alone (n = 166), CT plus Bev (n = 72), and CT plus ICI (n = 85). Treatment efficacy assessments were performed every two cycles according to the RECIST guidelines. The endpoints were overall survival (OS) and progression-free survival (PFS). Kaplan-Meier (K‒M) curves and the log-rank test were used to compare OS and PFS. p < 0.05 was the threshold of significance (statistical software: SPSS). The median follow-up was 11.4 months (range, 2.1-49.6 months). PFS and OS in the CT plus ICI/CT plus Bev cohort were significantly longer than those in the CT group (PFS: 7.8/6.4/3.9 months, p < 0.0001; OS: 16.4/15.6/9.6 months, p < 0.0001, respectively). CT plus Bev had better PFS and OS than CT plus ICI/CT in PD-L1 < 1% patients (PFS: 8.4/5.0/3.8 months, p < 0.0001; OS: 15.6/12.9/9.3 months, p < 0.0001). Among patients with PD-L1 1-49%, CT plus ICI led to a longer PFS and OS (PFS: 8.9/5.8/4.2 months, p = 0.009; OS: 24.2/18.8/11.5 months, p = 0.03). In the cohort with PD-L1 ≥ 50%, CT plus ICI was still the best first-line treatment (PFS: 19.7/13.8/9.6 months, p = 0.033; OS: 27.2/19.6/14.9 months, p = 0.047). In driver gene-negative MLA with MPE, CT plus Bev or ICI better controlled MPE and significantly prolonged survival compared to CT alone. PD-L1 expression (negative/positive) may be a key factor influencing the choice of CT plus Bev or ICI.


Asunto(s)
Adenocarcinoma del Pulmón , Neoplasias Pulmonares , Derrame Pleural Maligno , Humanos , Bevacizumab , Neoplasias Pulmonares/tratamiento farmacológico , Neoplasias Pulmonares/genética , Neoplasias Pulmonares/patología , Inhibidores de Puntos de Control Inmunológico/uso terapéutico , Antígeno B7-H1 , Derrame Pleural Maligno/patología , Estudios Retrospectivos , Adenocarcinoma del Pulmón/tratamiento farmacológico , Adenocarcinoma del Pulmón/genética
2.
Chemistry ; 30(37): e202401488, 2024 Jul 02.
Artículo en Inglés | MEDLINE | ID: mdl-38695300

RESUMEN

Borates have garnered a lot of attention in the realm of solid-state chemistry due to their remarkable characteristics, in which the synthesis of borates with isolated [BO3] by adding rare-earth elements is one of the main areas of structural design study. Five new mixed-metal Y-based rare-earth borates, Ba2ZnY2(BO3)4, KNa2Y(BO3)2, Li2CsY4(BO3)5, LiRb2Y(BO3)2, and RbCaY(BO3)2, have been discovered using the high-temperature solution approach. Isolated [BO3] clusters arranged in various configurations comprise their entire anionic framework, allowing for optical anisotropy tuning between 0.024 and 0.081 under 1064 nm. In this study, we characterize the relative placements of their [BO3] groups and examine how their structure affects their characteristics. The origin of their considerable optical anisotropy has been proven theoretically. This study unequivocally demonstrates that even a slight alteration to borates' anionic structure can result in a significant improvement in performance.

3.
Hum Brain Mapp ; 44(6): 2380-2394, 2023 04 15.
Artículo en Inglés | MEDLINE | ID: mdl-36691973

RESUMEN

Prenatal depressive symptoms are linked to negative child behavioral and cognitive outcomes and predict later psychopathology in adolescent children. Prior work links prenatal depressive symptoms to child brain structure in regions like the amygdala; however, the relationship between symptoms and the development of brain structure over time remains unclear. We measured maternal depressive symptoms during pregnancy and acquired longitudinal T1-weighted and diffusion imaging data in children (n = 111; 60 females) between 2.6 and 8 years of age. Controlling for postnatal symptoms, we used linear mixed effects models to test relationships between prenatal depressive symptoms and age-related changes in (i) amygdala and hippocampal volume and (ii) structural properties of the limbic and default-mode networks using graph theory. Higher prenatal depressive symptoms in the second trimester were associated with more curvilinear trajectories of left amygdala volume changes. Higher prenatal depressive symptoms in the third trimester were associated with slower age-related changes in limbic global efficiency and average node degree across childhood. Our work provides evidence that moderate symptoms of prenatal depression in a low sociodemographic risk sample are associated with structural brain development in regions and networks implicated in emotion processing.


Asunto(s)
Depresión , Efectos Tardíos de la Exposición Prenatal , Femenino , Embarazo , Adolescente , Niño , Humanos , Depresión/diagnóstico por imagen , Red en Modo Predeterminado/patología , Imagen por Resonancia Magnética/métodos , Efectos Tardíos de la Exposición Prenatal/diagnóstico por imagen , Efectos Tardíos de la Exposición Prenatal/patología , Encéfalo/patología
4.
J Neurosci Res ; 101(12): 1849-1863, 2023 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-37732456

RESUMEN

Studies have shown that prenatal maternal stress (PNMS) affects brain structure and function in childhood. However, less research has examined whether PNMS effects on brain structure and function extend to young adulthood. We recruited women who were pregnant during or within 3 months following the 1998 Quebec ice storm, assessed their PNMS, and prospectively followed-up their children. T1-weighted magnetic resonance imaging (MRI) and resting-state functional MRI were obtained from 19-year-old young adults with (n = 39) and without (n = 65) prenatal exposure to the ice storm. We examined between-group differences in gray matter volume (GMV), surface area (SA), and cortical thickness (CT). We used the brain regions showing between-group GMV differences as seeds to compare between-group functional connectivity. Within the Ice Storm group, we examined (1) associations between PNMS and the atypical GMV, SA, CT, and functional connectivity, and (2) moderation by timing of exposure. Primarily, we found that, compared to Controls, the Ice Storm youth had larger GMV and higher functional connectivity of the anterior cingulate cortex, the precuneus, the left occipital pole, and the right hippocampus; they also had larger CT, but not SA, of the left occipital pole. Within the Ice Storm group, maternal subjective distress during preconception and mid-to-late pregnancy was associated with atypical left occipital pole CT. These results suggest the long-lasting impact of disaster-related PNMS on child brain structure and functional connectivity. Our study also indicates timing-specific effects of the subjective aspect of PNMS on occipital thickness.

5.
Inorg Chem ; 62(26): 10059-10063, 2023 Jul 03.
Artículo en Inglés | MEDLINE | ID: mdl-37339069

RESUMEN

Polymorphism is a well-known but important phenomenon in the field of solid-state chemistry. Crystalline materials can form various polymorphs and present drastically varied physical and chemical properties. Herein, systematic exploration of the BaO-MoO3 binary system leads to the discovery of a new barium molybdate, α-BaMo3O10. The temperature-dependent phase transition from α-BaMo3O10 to ß-BaMo3O10 is confirmed. The tunable linear and nonlinear optical properties induced by the phase transition are confirmed by both experimental and theoretical approaches. Also, ß-BaMo3O10 is identified as a nonlinear-optical crystal for the first time. The origin of linear- and nonlinear-optical properties of BaMo3O10 polymorphs is confirmed by the additional theoretical means. This work indicates that a small change in the structure can induce tunable symmetries and thereby widely divergent optical properties.

6.
Hum Brain Mapp ; 43(3): 1032-1046, 2022 02 15.
Artículo en Inglés | MEDLINE | ID: mdl-34748258

RESUMEN

Sophisticated network-based approaches such as structural connectomics may help to detect a biomarker of mild traumatic brain injury (mTBI) in children. This study compared the structural connectome of children with mTBI or mild orthopedic injury (OI) to that of typically developing (TD) children. Children aged 8-16.99 years with mTBI (n = 83) or OI (n = 37) were recruited from the emergency department and completed 3T diffusion MRI 2-20 days postinjury. TD children (n = 39) were recruited from the community and completed diffusion MRI. Graph theory metrics were calculated for the binarized average fractional anisotropy among 90 regions. Multivariable linear regression and linear mixed effects models were used to compare groups, with covariates age, hemisphere, and sex, correcting for multiple comparisons. The two injury groups did not differ on graph theory metrics, but both differed from TD children in global metrics (local network efficiency: TD > OI, mTBI, d = 0.49; clustering coefficient: TD < OI, mTBI, d = 0.49) and regional metrics for the fusiform gyrus (lower degree centrality and nodal efficiency: TD > OI, mTBI, d = 0.80 to 0.96; characteristic path length: TD < OI, mTBI, d = -0.75 to -0.90) and in the superior and middle orbital frontal gyrus, paracentral lobule, insula, and thalamus (clustering coefficient: TD > OI, mTBI, d = 0.66 to 0.68). Both mTBI and OI demonstrated reduced global and regional network efficiency and segregation as compared to TD children. Findings suggest a general effect of childhood injury that could reflect pre- and postinjury factors that can alter brain structure. An OI group provides a more conservative comparison group than TD children for structural neuroimaging research in pediatric mTBI.


Asunto(s)
Conmoción Encefálica/patología , Encéfalo/patología , Imagen de Difusión Tensora , Fracturas Óseas/patología , Red Nerviosa/patología , Esguinces y Distensiones/patología , Adolescente , Encéfalo/diagnóstico por imagen , Conmoción Encefálica/diagnóstico por imagen , Niño , Femenino , Fracturas Óseas/diagnóstico por imagen , Humanos , Estudios Longitudinales , Masculino , Red Nerviosa/diagnóstico por imagen , Esguinces y Distensiones/diagnóstico por imagen
7.
Crit Care ; 26(1): 68, 2022 03 24.
Artículo en Inglés | MEDLINE | ID: mdl-35331299

RESUMEN

BACKGROUND: Secondary nosocomial infections, which are commonly caused by carbapenem-resistant Klebsiella pneumoniae (CRKP) and vancomycin-resistant Enterococcus faecium (VRE), often develop in septic patients. This study aimed to identify the origin of secondary systemic pathogens and reveal the underlying mechanism of infection. METHODS: In this prospective, observational case-control study, a total of 34 septic patients, 33 non-septic intensive care unit (ICU) patients and 10 healthy individuals serving as controls were enrolled. Three hundred and twelve fecal samples were collected and subjected to 16S rRNA gene amplicon sequencing. Metagenome sequencing was performed to identify the homology between dominant CRKP or VRE in the intestine and pathogens isolated from secondary infectious sites. C57/BL mice were established as pseudo germ-free animal model by pretreatment with broad-spectrum antibiotics for two weeks. RESULTS: The abundance and diversity of the gut microbiota in septic patients was drastically decreased one week after ICU admission, potentially leading to the enrichment of antibiotic-resistant bacteria, such as CRKP. Furthermore, secondary bloodstream and abdominal infections caused by CRKP or VRE in septic patients occurred after intestinal colonization with the predominant bacterial species. Genomic analysis showed that bacteria isolated from secondary infection had high homology with the corresponding predominant intestinal opportunistic pathogens. In addition, animal model experiments validated the hypothesis that the administration of antibiotics caused the enrichment of CRKP and VRE among the intestinal microbiota, increasing the likelihood of permeation of other tissues and potentially causing subsequent systemic infection in pseudo germ-free mice. CONCLUSION: Our study indicated that the pathogens causing secondary infection in septic patients might originate from the intestinal colonization of pathogens following broad-spectrum antibiotic treatment.


Asunto(s)
Coinfección , Sepsis , Animales , Estudios de Casos y Controles , Genotipo , Humanos , Ratones , Estudios Prospectivos , ARN Ribosómico 16S/genética , Sepsis/tratamiento farmacológico
8.
BMC Psychiatry ; 22(1): 611, 2022 09 15.
Artículo en Inglés | MEDLINE | ID: mdl-36109720

RESUMEN

BACKGROUND: Identifying early biomarkers of serious mental illness (SMI)-such as changes in brain structure and function-can aid in early diagnosis and treatment. Whole brain structural and functional connectomes were investigated in youth at risk for SMI. METHODS: Participants were classified as healthy controls (HC; n = 33), familial risk for serious mental illness (stage 0; n = 31), mild symptoms (stage 1a; n = 37), attenuated syndromes (stage 1b; n = 61), or discrete disorder (transition; n = 9) based on clinical assessments. Imaging data was collected from two sites. Graph-theory based analysis was performed on the connectivity matrix constructed from whole-brain white matter fibers derived from constrained spherical deconvolution of the diffusion tensor imaging (DTI) scans, and from the correlations between brain regions measured with resting state functional magnetic resonance imaging (fMRI) data. RESULTS: Linear mixed effects analysis and analysis of covariance revealed no significant differences between groups in global or nodal metrics after correction for multiple comparisons. A follow up machine learning analysis broadly supported the findings. Several non-overlapping frontal and temporal network differences were identified in the structural and functional connectomes before corrections. CONCLUSIONS: Results suggest significant brain connectome changes in youth at transdiagnostic risk may not be evident before illness onset.


Asunto(s)
Conectoma , Trastornos Mentales , Adolescente , Encéfalo/diagnóstico por imagen , Conectoma/métodos , Imagen de Difusión Tensora , Humanos , Imagen por Resonancia Magnética , Trastornos Mentales/diagnóstico por imagen
9.
Neuroimage ; 242: 118448, 2021 11 15.
Artículo en Inglés | MEDLINE | ID: mdl-34358659

RESUMEN

Intra-individual transient temporal fluctuations in brain signal, as measured by fMRI blood oxygenation level dependent (BOLD) variability, is increasingly considered an important signal rather than measurement noise. Evidence from computational and cognitive neuroscience suggests that signal variability is a good proxy-measure of brain functional integrity and information processing capacity. Here, we sought to explore across-participant and longitudinal relationships between BOLD variability, age, and white matter structure in early childhood. We measured standard deviation of BOLD signal, total white matter volume, global fractional anisotropy (FA) and mean diffusivity (MD) during passive movie viewing in a sample of healthy children (aged 2-8 years; N = 83). We investigated how age and white matter development related to changes in BOLD variability both across- and within-participants. Our across-participant analyses using behavioural partial least squares (bPLS) revealed that the influence of age and white matter maturation on BOLD variability was highly interrelated. BOLD variability increased in widespread frontal, temporal and parietal regions, and decreased in the hippocampus and parahippocampal gyrus with age and white matter development. Our longitudinal analyses using linear mixed effects modelling revealed significant associations between BOLD variability, age and white matter microstructure. Analyses using artificial neural networks demonstrated that BOLD variability and white matter micro and macro-structure at earlier ages were strong predictors of BOLD variability at later ages. By characterizing the across-participant and longitudinal features of the association between BOLD variability and white matter micro- and macrostructure in early childhood, our results provide a novel perspective to understand structure-function relationships in the developing brain.


Asunto(s)
Imagen de Difusión Tensora/métodos , Sustancia Blanca/crecimiento & desarrollo , Anisotropía , Niño , Preescolar , Cognición , Femenino , Humanos , Estudios Longitudinales , Imagen por Resonancia Magnética , Masculino , Lóbulo Parietal/diagnóstico por imagen , Lóbulo Parietal/crecimiento & desarrollo , Sustancia Blanca/diagnóstico por imagen
10.
Neuroimage ; 217: 116903, 2020 08 15.
Artículo en Inglés | MEDLINE | ID: mdl-32389725

RESUMEN

Early childhood is an important period for language development that lays the foundation for future reading abilities. However, little research has focused on the functional brain systems supporting pre-reading language abilities in typically developing children. Here, we investigated functional connectivity using passive viewing functional magnetic resonance imaging (fMRI) in 50 healthy children aged 2.85-5.07 years (3.84 â€‹± â€‹0.60 years, 22 female/28 male). Children completed the NEPSY-II Phonological Processing and Speeded Naming subtests and underwent fMRI while watching a movie of their choice. Functional connectivity was measured between key brain reading areas (bilateral angular gyrus, superior temporal gyrus, and inferior frontal gyrus) and the rest of the brain. Age-adjusted pre-reading scores positively correlated with functional connectivity between (1) the right angular gyrus and superior temporal gyrus, (2) the bilateral angular gyri and right pars triangularis and motor areas, (3) the left superior temporal gyrus and bilateral medial frontal gyrus and right cerebellum, (4) the left pars triangularis and middle occipital gyrus and insula, and (5) the right pars triangularis and the bilateral thalamus. Higher pre-reading scores were associated with stronger negative functional connectivity between (1) the left angular gyrus and auditory cortex, (2) the left superior temporal gyrus and occipital vision areas, (3) the right pars triangularis and medial frontal region, and (4) the right superior temporal gyrus and the posterior cingulate/precuneus. These results suggest better integration of the reading network, as well as its connections with other brain areas that support language or reading, and more dissociation between reading areas and the default mode network, in young children with better pre-reading skills. Our findings show that relationships between functional connectivity and pre-reading language skills are evident in young children even before formal reading instruction.


Asunto(s)
Lenguaje , Red Nerviosa/fisiología , Lectura , Mapeo Encefálico , Corteza Cerebral/diagnóstico por imagen , Corteza Cerebral/fisiología , Niño , Preescolar , Femenino , Lateralidad Funcional , Humanos , Pruebas del Lenguaje , Imagen por Resonancia Magnética , Masculino , Red Nerviosa/diagnóstico por imagen , Pruebas Neuropsicológicas , Desempeño Psicomotor
11.
Mol Biol Rep ; 47(3): 1921-1933, 2020 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-32020426

RESUMEN

Gene expression profiles are increasingly applied to investigate molecular mechanism for which, normalization with suitable reference genes is critical. Previously we have reported several suitable reference genes for laticifer samples from rubber tree, however, little is known in leaf. The main objective of this current study was to identify some stable expression reference genes at various developmental stages of leaf, as well as during abiotic (high and low temperature extremes) and biotic stresses (pathogen stress). Gene expression profilings identified the ubiquitin-proteasome system as excellent potential as reference genes for rubber tree leaf. Among a total of 30 tested genes investigated, 24 new candidate (including 11 genes involved in the ubiquitin-proteasome system), 4 previously identified and 2 specific genes, were further evaluated using quantitative real-time PCR. Our results indicated that the new candidate genes had better expression stability comparing with others. For instance, an ubiquitin conjugating enzyme (RG0099) and three ubiquitin-protein ligases (RG0928, RG2190 and RG0118) expressed stably in all samples, and were confirmed to be suitable reference genes for rubber tree leaf under four different conditions. Finally, we suggest that using more than one reference gene may be appropriate in gene expression studies when employing different software to normalize gene expression data. Our findings have significant implications for the reliability of data obtained from genomics studies in rubber tree and perhaps in other species.


Asunto(s)
Perfilación de la Expresión Génica/normas , Hevea/genética , Enzimas Ubiquitina-Conjugadoras/genética , Ubiquitina-Proteína Ligasas/genética , Regulación del Desarrollo de la Expresión Génica , Regulación de la Expresión Génica de las Plantas , Hevea/crecimiento & desarrollo , Hojas de la Planta/genética , Hojas de la Planta/crecimiento & desarrollo , Proteínas de Plantas/genética , Reacción en Cadena en Tiempo Real de la Polimerasa/normas , Estándares de Referencia
12.
BMC Plant Biol ; 19(1): 591, 2019 Dec 27.
Artículo en Inglés | MEDLINE | ID: mdl-31881921

RESUMEN

BACKGROUND: Sucrose (Suc), as the precursor molecule for rubber biosynthesis in Hevea brasiliensis, is transported via phloem-mediated long-distance transport from leaves to laticifers in trunk bark, where latex (cytoplasm of laticifers) is tapped for rubber. In our previous report, six Suc transporter (SUT) genes have been cloned in Hevea tree, among which HbSUT3 is verified to play an active role in Suc loading to the laticifers. In this study, another latex-abundant SUT isoform, HbSUT5, with expressions only inferior to HbSUT3 was characterized especially for its roles in latex production. RESULTS: Both phylogenetic analysis and subcellular localization identify HbSUT5 as a tonoplast-localized SUT protein under the SUT4-clade (=type III). Suc uptake assay in baker's yeast reveals HbSUT5 to be a typical Suc-H+ symporter, but its high affinity for Suc (Km = 2.03 mM at pH 5.5) and the similar efficiency in transporting both Suc and maltose making it a peculiar SUT under the SUT4-clade. At the transcript level, HbSUT5 is abundantly and preferentially expressed in Hevea barks. The transcripts of HbSUT5 are conspicuously decreased both in Hevea latex and bark by two yield-stimulating treatments of tapping and ethephon, the patterns of which are contrary to HbSUT3. Under the ethephon treatment, the Suc level in latex cytosol decreases significantly, but that in latex lutoids (polydispersed vacuoles) changes little, suggesting a role of the decreased HbSUT5 expression in Suc compartmentalization in the lutoids and thus enhancing the Suc sink strength in laticifers. CONCLUSIONS: Our findings provide insights into the roles of a vacuolar sucrose transporter, HbSUT5, in Suc exchange between lutoids and cytosol in rubber-producing laticifers.


Asunto(s)
Hevea/metabolismo , Látex/metabolismo , Proteínas de Transporte de Membrana/metabolismo , Proteínas de Plantas/metabolismo , Sacarosa/metabolismo , Citoplasma/metabolismo , Perfilación de la Expresión Génica , Regulación de la Expresión Génica de las Plantas , Hevea/genética , Floema/metabolismo , Corteza de la Planta/metabolismo , Regiones Promotoras Genéticas , Saccharomyces cerevisiae , Vacuolas/metabolismo
13.
Brain Cogn ; 134: 71-79, 2019 08.
Artículo en Inglés | MEDLINE | ID: mdl-30007529

RESUMEN

Magnetic resonance imaging (MRI) studies show that bilingual adults display structural and functional brain alterations, especially in the inferior frontal gyrus (IFG), dependent on when they learned their second language. However, it is unclear whether these differences are due to early exposure to another language, or to lifelong adaptation. We studied 22 children aged 3-5 years growing up in a multilingual environment and 22 age- and sex-matched controls exposed to an English-only environment. Resting-state functional MRI and T1-weighted MRI were used to assess functional connectivity and structure of the IFG. Children in a multilingual environment had higher functional connectivity between the left IFG and dorsal language and attention areas compared to children from a monolingual environment. Children in a multilingual environment also displayed decreased functional connectivity to temporal, anterior cingulate, and prefrontal areas. No significant group differences in IFG structure were observed. Our results suggest a more integrated functional language network, which is more segregated from other networks, in children who grow up in a multilingual environment. These findings suggest that functional alterations to the IFG due to second language learning occur early, while structural changes may not be apparent until later.


Asunto(s)
Multilingüismo , Neuroimagen/métodos , Corteza Prefrontal/diagnóstico por imagen , Mapeo Encefálico/métodos , Preescolar , Femenino , Humanos , Lenguaje , Imagen por Resonancia Magnética/métodos , Masculino , Imagen Multimodal , Medio Social
14.
Hum Brain Mapp ; 39(5): 2258-2268, 2018 05.
Artículo en Inglés | MEDLINE | ID: mdl-29436054

RESUMEN

Children with prenatal alcohol exposure (PAE) often have impaired sensorimotor function. While altered brain structure has been noted in sensorimotor areas, the functional brain alterations remain unclear. This study aims to investigate sensorimotor brain networks in children and youth with PAE using resting-state functional magnetic resonance imaging (rs-fMRI). A parcellation-based network analysis was performed to identify brain networks related to hand/lower limb and face/upper limb function in 59 children and youth with PAE and 50 typically developing controls. Participants with PAE and controls had similar organization of the hand and face areas within the primary sensorimotor cortex, but participants with PAE had altered functional connectivity (FC) between the sensorimotor regions and the rest of the brain. The sensorimotor regions in the PAE group showed less connectivity to certain hubs of the default mode network and more connectivity to areas of the salience network. Overall, our results show that despite similar patterns of organization in the sensorimotor network, subjects with PAE have increased FC between this network and other brain areas, perhaps suggesting overcompensation. These alterations in the sensorimotor network lay the foundation for future studies to evaluate interventions and treatments to improve motor function in children with PAE.


Asunto(s)
Mapeo Encefálico , Trastornos del Espectro Alcohólico Fetal/patología , Vías Nerviosas/patología , Corteza Sensoriomotora/patología , Adolescente , Factores de Edad , Niño , Correlación de Datos , Femenino , Trastornos del Espectro Alcohólico Fetal/diagnóstico por imagen , Lateralidad Funcional , Humanos , Procesamiento de Imagen Asistido por Computador , Imagen por Resonancia Magnética , Masculino , Vías Nerviosas/diagnóstico por imagen , Corteza Sensoriomotora/diagnóstico por imagen
15.
Cereb Cortex ; 27(7): 3790-3805, 2017 07 01.
Artículo en Inglés | MEDLINE | ID: mdl-28184419

RESUMEN

The cytoarchitectonic map as proposed by Brodmann currently dominates models of human sensorimotor cortical structure, function, and plasticity. According to this model, primary motor cortex, area 4, and primary somatosensory cortex, area 3b, are homogenous areas, with the major division lying between the two. Accumulating empirical and theoretical evidence, however, has begun to question the validity of the Brodmann map for various cortical areas. Here, we combined in vivo cortical myelin mapping with functional connectivity analyses and topographic mapping techniques to reassess the validity of the Brodmann map in human primary sensorimotor cortex. We provide empirical evidence that area 4 and area 3b are not homogenous, but are subdivided into distinct cortical fields, each representing a major body part (the hand and the face). Myelin reductions at the hand-face borders are cortical layer-specific, and coincide with intrinsic functional connectivity borders as defined using large-scale resting state analyses. Our data extend the Brodmann model in human sensorimotor cortex and suggest that body parts are an important organizing principle, similar to the distinction between sensory and motor processing.


Asunto(s)
Mapeo Encefálico , Cuerpo Humano , Corteza Motora/fisiología , Movimiento/fisiología , Vías Nerviosas/fisiología , Corteza Sensoriomotora/fisiología , Adulto , Cara/inervación , Femenino , Mano/inervación , Humanos , Procesamiento de Imagen Asistido por Computador , Imagen por Resonancia Magnética , Masculino , Corteza Motora/diagnóstico por imagen , Red Nerviosa/diagnóstico por imagen , Red Nerviosa/fisiología , Vías Nerviosas/diagnóstico por imagen , Estimulación Física , Corteza Sensoriomotora/diagnóstico por imagen , Adulto Joven
16.
Neuroimage ; 155: 322-330, 2017 07 15.
Artículo en Inglés | MEDLINE | ID: mdl-28461057

RESUMEN

Brain function and structure change significantly during the toddler and preschool years. However, most studies focus on older or younger children, so the specific nature of these changes is unclear. In the present study, we analyzed 77 functional magnetic resonance imaging datasets from 44 children aged 2-6 years. We extracted measures of both local (amplitude of low frequency fluctuation and regional homogeneity) and global (eigenvector centrality mapping) activity and connectivity, and examined their relationships with age using robust linear correlation analysis and strict control for head motion. Brain areas within the default mode network and the frontoparietal network, such as the middle frontal gyrus, the inferior parietal lobule and the posterior cingulate cortex, showed increases in local and global functional features with age. Several brain areas such as the superior parietal lobule and superior temporal gyrus presented opposite development trajectories of local and global functional features, suggesting a shifting connectivity framework in early childhood. This development of functional connectivity in early childhood likely underlies major advances in cognitive abilities, including language and development of theory of mind. These findings provide important insight into the development patterns of brain function during the preschool years, and lay the foundation for future studies of altered brain development in young children with brain disorders or injury.


Asunto(s)
Corteza Cerebral/fisiología , Desarrollo Infantil/fisiología , Conectoma/métodos , Corteza Cerebral/diagnóstico por imagen , Corteza Cerebral/crecimiento & desarrollo , Niño , Preescolar , Femenino , Humanos , Imagen por Resonancia Magnética , Masculino
17.
J Neurosci ; 35(15): 5917-25, 2015 Apr 15.
Artículo en Inglés | MEDLINE | ID: mdl-25878264

RESUMEN

Most sensory input to our body is not consciously perceived. Nevertheless, it may reach the cortex and influence our behavior. In this study, we investigated noninvasive neural signatures of unconscious cortical stimulus processing to understand mechanisms, which (1) prevent low-intensity somatosensory stimuli from getting access to conscious experience and which (2) can explain the associated impediment of conscious perception for additional stimuli. Stimulation of digit 2 in humans far below the detection threshold elicited a cortical evoked potential (P1) at 60 ms, but no further somatosensory evoked potential components. No event-related desynchronization was detected; rather, there was a transient synchronization in the alpha frequency range. Using the same stimulation during fMRI, a reduced centrality of contralateral primary somatosensory cortex (SI) was found, which appeared to be mainly driven by reduced functional connectivity to frontoparietal areas. We conclude that after subthreshold stimulation the (excitatory) feedforward sweep of bottom-up processing terminates in SI preventing access to conscious experience. We speculate that this interruption is due to a predominance of inhibitory processing in SI. The increase in alpha activity and the disconnection of SI from frontoparietal areas are likely correlates of an elevated perception threshold and may thus serve as a gating mechanism for the access to conscious experience.


Asunto(s)
Vías Aferentes/irrigación sanguínea , Mapeo Encefálico , Potenciales Evocados Somatosensoriales/fisiología , Periodicidad , Corteza Somatosensorial/irrigación sanguínea , Corteza Somatosensorial/fisiología , Adulto , Vías Aferentes/fisiología , Estimulación Eléctrica , Electroencefalografía , Femenino , Humanos , Procesamiento de Imagen Asistido por Computador , Imagen por Resonancia Magnética , Masculino , Oxígeno/sangre , Tiempo de Reacción , Adulto Joven
19.
Eur J Neurosci ; 39(8): 1332-42, 2014 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-24417550

RESUMEN

Task-based functional magnetic resonance imaging (fMRI) has been successfully employed to obtain somatotopic maps of the human sensorimotor cortex. Here, we showed through direct comparison that a similar functional map can be obtained, independently of a task, by performing a connectivity-based parcellation of the sensorimotor cortex based on resting-state fMRI. Cortex corresponding to two adjacent Brodmann areas (BA 3 and BA 4) was selected as the sensorimotor area. Parcellation was obtained along a medial-lateral axis, which was confirmed to be somatotopic (corresponding roughly to an upper, middle and lower limb, respectively) by comparing it with maps obtained using motoric task-based fMRI in the same participants. Interestingly, the resting-state parcellation map demonstrated higher correspondence to the task-based divisions after individuals performed the motor task. Using the resting-state fMRI data, we also observed higher functional correlations between the centrally located hand region and the other two regions, than between the foot and tongue. The functional relevance of these somatosensory parcellation results indicates the feasibility of a wide range of potential applications to brain mapping.


Asunto(s)
Conectoma , Corteza Somatosensorial/fisiología , Adulto , Femenino , Humanos , Masculino , Desempeño Psicomotor
20.
Ann Neurol ; 73(1): 136-40, 2013 Jan.
Artículo en Inglés | MEDLINE | ID: mdl-23378326

RESUMEN

Temporal delay in blood oxygenation level-dependent (BOLD) signals may be sensitive to perfusion deficits in acute stroke. Resting-state functional magnetic resonance imaging (rsfMRI) was added to a standard stroke MRI protocol. We calculated the time delay between the BOLD signal at each voxel and the whole-brain signal using time-lagged correlation and compared the results to mean transit time derived using bolus tracking. In all 11 patients, areas exhibiting significant delay in BOLD signal corresponded to areas of hypoperfusion identified by contrast-based perfusion MRI. Time delay analysis of rsfMRI provides information comparable to that of conventional perfusion MRI without the need for contrast agents.


Asunto(s)
Circulación Cerebrovascular/fisiología , Imagen por Resonancia Magnética/métodos , Descanso/fisiología , Accidente Cerebrovascular/diagnóstico , Accidente Cerebrovascular/fisiopatología , Adulto , Anciano , Anciano de 80 o más Años , Femenino , Humanos , Masculino , Persona de Mediana Edad
SELECCIÓN DE REFERENCIAS
DETALLE DE LA BÚSQUEDA