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1.
Neurobiol Dis ; 153: 105316, 2021 06.
Artigo em Inglês | MEDLINE | ID: mdl-33711492

RESUMO

The neurodevelopmental phenotype in Down Syndrome (DS), or Trisomy 21, is variable including a wide spectrum of cognitive impairment and a high risk of early-onset Alzheimer's disease (AD). A key metabolite of interest within the brain in DS is Myo-inositol (mIns). The NA+/mIns co-transporter is located on human chromosome 21 and is overexpressed in DS. In adults with DS, elevated brain mIns was previously associated with cognitive impairment and proposed as a risk marker for progression to AD. However, it is unknown if brain mIns is increased earlier in development. The aim of this study was to estimate mIns concentration levels and key brain metabolites [N-acetylaspartate (NAA), Choline (Cho) and Creatine (Cr)] in the developing brain in DS and aged-matched controls. We used in vivo magnetic resonance spectroscopy (MRS) in neonates with DS (n = 12) and age-matched controls (n = 26) scanned just after birth (36-45 weeks postmenstrual age). Moreover, we used Mass Spectrometry in early (10-20 weeks post conception) ex vivo fetal brain tissue samples from DS (n = 14) and control (n = 30) cases. Relative to [Cho] and [Cr], we report elevated ratios of [mIns] in vivo in the basal ganglia/thalamus, in neonates with DS, when compared to age-matched typically developing controls. Glycine concentration ratios [Gly]/[Cr] and [Cho]/[Cr] also appear elevated. We observed elevated [mIns] in the ex vivo fetal cortical brain tissue in DS compared with controls. In conclusion, a higher level of brain mIns was evident as early as 10 weeks post conception and was measurable in vivo from 36 weeks post-menstrual age. Future work will determine if this early difference in metabolites is linked to cognitive outcomes in childhood or has utility as a potential treatment biomarker for early intervention.


Assuntos
Encéfalo/metabolismo , Síndrome de Down/metabolismo , Feto/metabolismo , Inositol/metabolismo , Ácido Aspártico/análogos & derivados , Ácido Aspártico/metabolismo , Encéfalo/embriologia , Encéfalo/crescimento & desenvolvimento , Colina/metabolismo , Creatina/metabolismo , Feminino , Feto/embriologia , Glicina/metabolismo , Humanos , Recém-Nascido , Espectroscopia de Ressonância Magnética , Masculino
2.
Cereb Cortex ; 30(11): 5767-5779, 2020 10 01.
Artigo em Inglês | MEDLINE | ID: mdl-32537627

RESUMO

Interruptions to neurodevelopment during the perinatal period may have long-lasting consequences. However, to be able to investigate deviations in the foundation of proper connectivity and functional circuits, we need a measure of how this architecture evolves in the typically developing brain. To this end, in a cohort of 241 term-born infants, we used magnetic resonance imaging to estimate cortical profiles based on morphometry and microstructure over the perinatal period (37-44 weeks postmenstrual age, PMA). Using the covariance of these profiles as a measure of inter-areal network similarity (morphometric similarity networks; MSN), we clustered these networks into distinct modules. The resulting modules were consistent and symmetric, and corresponded to known functional distinctions, including sensory-motor, limbic, and association regions, and were spatially mapped onto known cytoarchitectonic tissue classes. Posterior regions became more morphometrically similar with increasing age, while peri-cingulate and medial temporal regions became more dissimilar. Network strength was associated with age: Within-network similarity increased over age suggesting emerging network distinction. These changes in cortical network architecture over an 8-week period are consistent with, and likely underpin, the highly dynamic processes occurring during this critical period. The resulting cortical profiles might provide normative reference to investigate atypical early brain development.


Assuntos
Encéfalo/crescimento & desenvolvimento , Neurogênese/fisiologia , Feminino , Humanos , Recém-Nascido , Imageamento por Ressonância Magnética , Masculino
3.
Lancet ; 393(10181): 1619-1627, 2019 Apr 20.
Artigo em Inglês | MEDLINE | ID: mdl-30910324

RESUMO

BACKGROUND: Two-dimensional (2D) ultrasound echocardiography is the primary technique used to diagnose congenital heart disease before birth. There is, however, a longstanding need for a reliable form of secondary imaging, particularly in cases when more detailed three-dimensional (3D) vascular imaging is required, or when ultrasound windows are of poor diagnostic quality. Fetal MRI, which is well established for other organ systems, is highly susceptible to fetal movement, particularly for 3D imaging. The objective of this study was to investigate the combination of prenatal MRI with novel, motion-corrected 3D image registration software, as an adjunct to fetal echocardiography in the diagnosis of congenital heart disease. METHODS: Pregnant women carrying a fetus with known or suspected congenital heart disease were recruited via a tertiary fetal cardiology unit. After initial validation experiments to assess the general reliability of the approach, MRI data were acquired in 85 consecutive fetuses, as overlapping stacks of 2D images. These images were then processed with a bespoke open-source reconstruction algorithm to produce a super-resolution 3D volume of the fetal thorax. These datasets were assessed with measurement comparison with paired 2D ultrasound, structured anatomical assessment of the 2D and 3D data, and contemporaneous, archived clinical fetal MRI reports, which were compared with postnatal findings after delivery. FINDINGS: Between Oct 8, 2015, and June 30, 2017, 101 patients were referred for MRI, of whom 85 were eligible and had fetal MRI. The mean gestational age at the time of MRI was 32 weeks (range 24-36). High-resolution (0·50-0·75 mm isotropic) 3D datasets of the fetal thorax were generated in all 85 cases. Vascular measurements showed good overall agreement with 2D echocardiography in 51 cases with paired data (intra-class correlation coefficient 0·78, 95% CI 0·68-0·84), with fetal vascular structures more effectively visualised with 3D MRI than with uncorrected 2D MRI (657 [97%] of 680 anatomical areas identified vs 358 [53%] of 680 areas; p<0·0001). When a structure of interest was visualised in both 2D and 3D data (n=358), observers gave a higher diagnostic quality score for 3D data in 321 (90%) of cases, with 37 (10%) scores tied with 2D data, and no lower scores than for 2D data (Wilcoxon signed rank test p<0·0001). Additional anatomical features were described in ten cases, of which all were confirmed postnatally. INTERPRETATION: Standard fetal MRI with open-source image processing software is a reliable method of generating high-resolution 3D imaging of the fetal vasculature. The 3D volumes produced show good spatial agreement with ultrasound, and significantly improved visualisation and diagnostic quality compared with source 2D MRI data. This freely available combination requires minimal infrastructure, and provides safe, powerful, and highly complementary imaging of the fetal cardiovascular system. FUNDING: Wellcome Trust/EPSRC Centre for Medical Engineering, National Institute for Health Research.


Assuntos
Cardiotocografia/métodos , Coração Fetal/diagnóstico por imagem , Processamento de Imagem Assistida por Computador/métodos , Imageamento Tridimensional/métodos , Imageamento por Ressonância Magnética , Feminino , Coração Fetal/patologia , Idade Gestacional , Cardiopatias Congênitas/diagnóstico , Humanos , Gravidez , Estudos Prospectivos , Ultrassonografia Pré-Natal
4.
Pediatr Res ; 87(6): 1066-1071, 2020 05.
Artigo em Inglês | MEDLINE | ID: mdl-31812155

RESUMO

BACKGROUND: Infants born preterm are at increased risk of pulmonary morbidity. The contribution of antenatal factors to impairments in lung structure/function has not been fully elucidated. This study aimed to compare standardized lung volumes from foetuses that were delivered <32 weeks' gestation with foetuses that were delivered >37 weeks. METHODS: Fourteen women who delivered <32 weeks gestation and 56 women who delivered >37 underwent a foetal MRI. Slice-volume reconstruction was then used and the foetal lungs were then segmented using multi-atlas approaches. Body volumes were calculated by manual segmentation and lung:body volume ratios generated. RESULTS: Mean gestation at MRI of the preterm group was 27+2 weeks (SD 2.9, range 20+6-31+3) and control group 25+3 weeks (SD 4.7 range 20+5-31+6). Mean gestation at delivery of the preterm group was 29+2 weeks (SD 2.6, range 22+0-32+0). Lung:body volume ratios and foetal lung volumes were smaller in foetuses that were delivered preterm both with and without preterm premature rupture of membranes compared to those born at term (p < 0.001 in all cases). CONCLUSIONS: Foetuses that were delivered very preterm had reduced lung volumes when standardized for foetal size, irrespective of ruptured membranes. These are novel findings and suggest an antenatal aetiology of insult and possible focus for future preventative therapies.


Assuntos
Recém-Nascido Prematuro , Pulmão/diagnóstico por imagem , Imageamento por Ressonância Magnética , Nascimento Prematuro , Adulto , Estudos de Casos e Controles , Feminino , Idade Gestacional , Humanos , Pulmão/fisiopatologia , Medidas de Volume Pulmonar , Pessoa de Meia-Idade , Tamanho do Órgão , Projetos Piloto , Valor Preditivo dos Testes , Gravidez , Estudos Prospectivos , Adulto Jovem
5.
Magn Reson Med ; 78(2): 794-804, 2017 08.
Artigo em Inglês | MEDLINE | ID: mdl-27643791

RESUMO

PURPOSE: The goal of the Developing Human Connectome Project is to acquire MRI in 1000 neonates to create a dynamic map of human brain connectivity during early development. High-quality imaging in this cohort without sedation presents a number of technical and practical challenges. METHODS: We designed a neonatal brain imaging system (NBIS) consisting of a dedicated 32-channel receive array coil and a positioning device that allows placement of the infant's head deep into the coil for maximum signal-to-noise ratio (SNR). Disturbance to the infant was minimized by using an MRI-compatible trolley to prepare and transport the infant and by employing a slow ramp-up and continuation of gradient noise during scanning. Scan repeats were minimized by using a restart capability for diffusion MRI and retrospective motion correction. We measured the 1) SNR gain, 2) number of infants with a completed scan protocol, and 3) number of anatomical images with no motion artifact using NBIS compared with using an adult 32-channel head coil. RESULTS: The NBIS has 2.4 times the SNR of the adult coil and 90% protocol completion rate. CONCLUSION: The NBIS allows advanced neonatal brain imaging techniques to be employed in neonatal brain imaging with high protocol completion rates. Magn Reson Med 78:794-804, 2017. © 2016 The Authors Magnetic Resonance in Medicine published by Wiley Periodicals, Inc. on behalf of International Society for Magnetic Resonance in Medicine. This is an open access article under the terms of the Creative Commons Attribution-NonCommercial-NoDerivs License, which permits use and distribution in any medium, provided the original work is properly cited, the use is non-commercial and no modifications or adaptations are made.


Assuntos
Encéfalo/diagnóstico por imagem , Conectoma/instrumentação , Recém-Nascido/fisiologia , Imageamento por Ressonância Magnética/instrumentação , Neuroimagem/instrumentação , Conectoma/métodos , Humanos , Imageamento por Ressonância Magnética/métodos , Neuroimagem/métodos , Razão Sinal-Ruído
6.
Cereb Cortex ; 25(11): 4310-8, 2015 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-25596587

RESUMO

Thalamocortical connections are: essential for brain function, established early in development, and significantly impaired following preterm birth. Impaired cognitive abilities in preterm infants may be related to disruptions in thalamocortical connectivity. The aim of this study was to test the hypothesis: thalamocortical connectivity in the preterm brain at term-equivalent is correlated with cognitive performance in early childhood. We examined 57 infants who were born <35 weeks gestational age (GA) and had no evidence of focal abnormality on magnetic resonance imaging (MRI). Infants underwent diffusion MRI at term and cognitive performance at 2 years was assessed using the Bayley III scales of Infant and Toddler development. Cognitive scores at 2 years were correlated with structural connectivity between the thalamus and extensive cortical regions at term. Mean thalamocortical connectivity across the whole cortex explained 11% of the variance in cognitive scores at 2 years. The inclusion of GA at birth and parental socioeconomic group in the model explained 30% of the variance in subsequent cognitive performance. Identifying impairments in thalamocortical connectivity as early as term equivalent can help identify those infants at risk of subsequent cognitive delay and may be useful to assess efficacy of potential treatments at an early age.


Assuntos
Córtex Cerebral/patologia , Transtornos Cognitivos/diagnóstico , Transtornos Cognitivos/etiologia , Nascimento Prematuro/patologia , Nascimento Prematuro/fisiopatologia , Tálamo/patologia , Imagem de Difusão por Ressonância Magnética , Feminino , Idade Gestacional , Substância Cinzenta/patologia , Humanos , Processamento de Imagem Assistida por Computador , Lactente , Recém-Nascido , Modelos Lineares , Imageamento por Ressonância Magnética , Masculino , Vias Neurais/patologia , Testes Neuropsicológicos , Valor Preditivo dos Testes
7.
Prenat Diagn ; 36(10): 916-925, 2016 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-27521762

RESUMO

OBJECTIVES: Fetal cardiovascular magnetic resonance imaging (MRI) offers a potential alternative to echocardiography, although in practice, its use has been limited. We sought to explore the need for additional imaging in a tertiary fetal cardiology unit and the usefulness of standard MRI sequences. METHODS: Cases where the diagnosis was not fully resolved using echocardiography were referred for MRI. Following a three-plane localiser, fetal movement was assessed with a balanced steady-state free precession (bSSFP) cine. Single-shot fast spin echo and bSSFP sequences were used for diagnostic imaging. RESULTS: Twenty-two fetal cardiac MRIs were performed over 12 months, at mean gestation of 32 weeks (26-38 weeks). The majority of referrals were for suspected vascular abnormalities (17/22), particularly involving the aortic arch (n = 10) and pulmonary vessels (n = 4). Single-shot fast spin echo sequences produced 'black-blood' images, useful for examining the extracardiac vasculature in these cases. BSSFP sequences were more useful for intracardiac structures. Real-time SSFP allowed for dynamic assessment of structures such as cardiac masses, with enhancement patterns also allowing for tissue characterisation in these cases. CONCLUSIONS: Fetal vascular abnormalities such as coarctation can be difficult to diagnose by using ultrasound. Fetal MRI may have an adjunctive role in the evaluation of the extracardiac vascular anatomy and tissue characterisation. © 2016 The Authors. Prenatal Diagnosis published by John Wiley & Sons, Ltd.


Assuntos
Ecocardiografia/métodos , Coração Fetal/diagnóstico por imagem , Cardiopatias Congênitas/diagnóstico por imagem , Imageamento por Ressonância Magnética/métodos , Aorta Torácica/anormalidades , Aorta Torácica/diagnóstico por imagem , Coartação Aórtica/diagnóstico por imagem , Divertículo/diagnóstico por imagem , Feminino , Coração Fetal/anormalidades , Comunicação Interventricular/diagnóstico por imagem , Humanos , Gravidez , Segundo Trimestre da Gravidez , Terceiro Trimestre da Gravidez , Diagnóstico Pré-Natal , Artéria Pulmonar/anormalidades , Artéria Pulmonar/diagnóstico por imagem , Veias Pulmonares/anormalidades , Veias Pulmonares/diagnóstico por imagem , Ultrassonografia Pré-Natal
8.
Magn Reson Med ; 73(5): 1795-802, 2015 May.
Artigo em Inglês | MEDLINE | ID: mdl-25046845

RESUMO

PURPOSE: The aim of this study was to determine T2* values for the fetal brain in utero and to compare them with previously reported values in preterm and term neonates. Knowledge of T2* may be useful for assessing brain development, brain abnormalities, and for optimizing functional imaging studies. METHODS: Maternal respiration and unpredictable fetal motion mean that conventional multishot acquisition techniques used in adult T2* relaxometry studies are not practical. Single shot multiecho echo planar imaging was used as a rapid method for measuring fetal T2* by effectively freezing intra-slice motion. RESULTS: T2* determined from a sample of 24 subjects correlated negatively with gestational age with mean values of 220 ms (±45) for frontal white matter, 159 ms (±32) for thalamic gray matter, and 236 ms (±45) for occipital white matter. CONCLUSION: Fetal T2* values are higher than those previously reported for preterm neonates and decline with a consistent trend across gestational age. The data suggest that longer than usual echo times or direct T2* measurement should be considered when performing fetal fMRI to reach optimal BOLD sensitivity.


Assuntos
Artefatos , Encéfalo/embriologia , Imagem Ecoplanar/métodos , Aumento da Imagem/métodos , Processamento de Imagem Assistida por Computador/métodos , Recém-Nascido Prematuro/crescimento & desenvolvimento , Imageamento por Ressonância Magnética/métodos , Feminino , Lobo Frontal/embriologia , Idade Gestacional , Humanos , Recém-Nascido , Lobo Occipital/embriologia , Gravidez , Valores de Referência , Sensibilidade e Especificidade , Tálamo/embriologia , Substância Branca/embriologia
9.
HIV Clin Trials ; 16(2): 81-7, 2015.
Artigo em Inglês | MEDLINE | ID: mdl-25874990

RESUMO

BACKGROUND: Perinatally acquired HIV-infected (PaHIV) young adults undergo neurodevelopment in the presence of HIV infection and antiretroviral therapy, which may lead to neurocognitive (NC) impairment. Knowledge of NC function in this group is sparse and control data lacking. We compared cerebral function in young adults with PaHIV infection to aged matched HIV negative family controls. METHODS: 16-25-year-old PaHIV young adults (Group 1, n = 33) and HIV-uninfected family controls (Group 2, n = 14) were recruited. Cerebral function was evaluated by: a computerized battery assessing NC function (CogState(TM)), International HIV Dementia Scale (IHDS) and the prospective and retrospective memory questionnaire (PRMQ). Eight cases and four controls also underwent (1)H cerebral magnetic resonance spectroscopy ((1)H-MRS) scanning measuring basal ganglia (BG) metabolites. Cases and controls were compared. RESULTS: Group 1 mean (SD) CD4 count; 444 (319) cells/µl, plasma HIV viral load < 50 in 55%. There were no statistically significant differences between study groups in NC function or IHDS results (P>0.27 all observations). PRMQ scores were significantly higher (42 versus 35, P = 0.02) and MRS BG inflammatory-metabolites (choline- and myo-inositol- to creatine ratios) were significantly greater in Group 1 versus Group 2 (0.83 versus 0.63, P = 0.02 and 3.43 versus 3.03.P = 0.09 respectively). No significant association between PRMQ score and MRS metabolites was observed (P = 0.89). CONCLUSION: Statistically significant differences in cerebral function parameters were observed in PaHIV young adults compared to a well-matched control population. The cognitive deficit observed, in memory, rather than fine motor function, differs from the cerebral impairment often reported in HIV-infected adults.


Assuntos
Transtornos Cognitivos/fisiopatologia , Infecções por HIV/fisiopatologia , Adolescente , Adulto , Contagem de Linfócito CD4 , Estudos de Casos e Controles , Transtornos Cognitivos/etiologia , Estudos de Coortes , Feminino , Infecções por HIV/complicações , Humanos , Inositol , Espectroscopia de Ressonância Magnética , Masculino , Transtornos da Memória/etiologia , Transtornos da Memória/fisiopatologia , Estudos Prospectivos , Estudos Retrospectivos , Irmãos , Inquéritos e Questionários , Carga Viral , Adulto Jovem
10.
Cereb Cortex ; 24(8): 2141-50, 2014 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-23508710

RESUMO

Mild cerebral ventricular enlargement is associated with schizophrenia, autism, epilepsy, and attention-deficit/hyperactivity disorder. Fetal ventriculomegaly is the most common central nervous system (CNS) abnormality affecting 1% of fetuses and is associated with cognitive, language, and behavioral impairments in childhood. Neurodevelopmental outcome is partially predictable by the 2-dimensional size of the ventricles in the absence of other abnormalities. We hypothesized that isolated fetal ventriculomegaly is a marker of altered brain development characterized by relative overgrowth and aimed to quantify brain growth using volumetric magnetic resonance imaging (MRI) in fetuses with isolated ventriculomegaly. Fetal brain MRI (1.5 T) was performed in 60 normal fetuses and 65 with isolated ventriculomegaly, across a gestational age range of 22-38 weeks. Volumetric analysis of the ventricles and supratentorial brain structures was performed on 3-dimensional reconstructed datasets. Fetuses with isolated ventriculomegaly had increased brain parenchyma volumes when compared with the control cohort (9.6%, P < 0.0001) with enlargement restricted to the cortical gray matter (17.2%, P = 0.002). The extracerebral cerebrospinal fluid and third and fourth ventricles were also enlarged. White matter, basal ganglia, and thalamic volumes were not significantly different between cohorts. The presence of relative cortical overgrowth in fetuses with ventriculomegaly may represent the neurobiological substrate for cognitive, language, and behavioral deficits in these children.


Assuntos
Encéfalo/embriologia , Ventrículos Cerebrais/embriologia , Doenças Fetais/patologia , Hidrocefalia/embriologia , Hidrocefalia/patologia , Encéfalo/patologia , Ventrículos Cerebrais/patologia , Feminino , Feto , Humanos , Imageamento Tridimensional , Imageamento por Ressonância Magnética , Masculino , Tamanho do Órgão
11.
Neuroimage ; 101: 555-68, 2014 Nov 01.
Artigo em Inglês | MEDLINE | ID: mdl-25008959

RESUMO

There is growing interest in exploring fetal functional brain development, particularly with Resting State fMRI. However, during a typical fMRI acquisition, the womb moves due to maternal respiration and the fetus may perform large-scale and unpredictable movements. Conventional fMRI processing pipelines, which assume that brain movements are infrequent or at least small, are not suitable. Previous published studies have tackled this problem by adopting conventional methods and discarding as much as 40% or more of the acquired data. In this work, we developed and tested a processing framework for fetal Resting State fMRI, capable of correcting gross motion. The method comprises bias field and spin history corrections in the scanner frame of reference, combined with slice to volume registration and scattered data interpolation to place all data into a consistent anatomical space. The aim is to recover an ordered set of samples suitable for further analysis using standard tools such as Group Independent Component Analysis (Group ICA). We have tested the approach using simulations and in vivo data acquired at 1.5 T. After full motion correction, Group ICA performed on a population of 8 fetuses extracted 20 networks, 6 of which were identified as matching those previously observed in preterm babies.


Assuntos
Mapeamento Encefálico/métodos , Encéfalo/embriologia , Feto/fisiologia , Imageamento por Ressonância Magnética/métodos , Rede Nervosa/fisiologia , Mapeamento Encefálico/normas , Feminino , Idade Gestacional , Humanos , Imageamento por Ressonância Magnética/normas , Movimento (Física) , Gravidez , Terceiro Trimestre da Gravidez , Diagnóstico Pré-Natal
12.
Cerebellum ; 12(5): 632-44, 2013 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-23553467

RESUMO

Fetal magnetic resonance imaging (MRI) is now routinely used to further investigate cerebellar malformations detected with ultrasound. However, the lack of 2D and 3D biometrics in the current literature hinders the detailed characterisation and classification of cerebellar anomalies. The main objectives of this fetal neuroimaging study were to provide normal posterior fossa growth trajectories during the second and third trimesters of pregnancy via semi-automatic segmentation of reconstructed fetal brain MR images and to assess common cerebellar malformations in comparison with the reference data. Using a 1.5-T MRI scanner, 143 MR images were obtained from 79 normal control and 53 fetuses with posterior fossa abnormalities that were grouped according to the severity of diagnosis on visual MRI inspections. All quantifications were performed on volumetric datasets, and supplemental outcome information was collected from the surviving infants. Normal growth trajectories of total brain, cerebellar, vermis, pons and fourth ventricle volumes showed significant correlations with 2D measurements and increased in second-order polynomial trends across gestation (Pearson r, p < 0.05). Comparison of normal controls to five abnormal cerebellum subgroups depicted significant alterations in volumes that could not be detected exclusively with 2D analysis (MANCOVA, p < 0.05). There were 15 terminations of pregnancy, 8 neonatal deaths, and a spectrum of genetic and neurodevelopmental outcomes in the assessed 24 children with cerebellar abnormalities. The given posterior fossa biometrics enhance the delineation of normal and abnormal cerebellar phenotypes on fetal MRI and confirm the advantages of utilizing advanced neuroimaging tools in clinical fetal research.


Assuntos
Doenças Cerebelares/patologia , Cerebelo/patologia , Fossa Craniana Posterior/patologia , Feto/patologia , Imageamento por Ressonância Magnética , Adulto , Cerebelo/anormalidades , Criança , Fossa Craniana Posterior/anormalidades , Feminino , Feto/diagnóstico por imagem , Idade Gestacional , Humanos , Processamento de Imagem Assistida por Computador/métodos , Lactente , Imageamento por Ressonância Magnética/métodos , Masculino , Pessoa de Meia-Idade , Gravidez , Radiografia , Ultrassonografia Pré-Natal/métodos , Adulto Jovem
13.
J Antimicrob Chemother ; 67(1): 206-12, 2012 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-21987241

RESUMO

BACKGROUND: We conducted a pharmacokinetic and in vivo cerebral (1)H magnetic resonance spectroscopy ((1)H-MRS) study to assess CSF exposure and cerebral metabolite ratios (CMRs) following maraviroc intensification. METHODS: HIV-infected neurologically asymptomatic adults receiving tenofovir, emtricitabine and lopinavir/ritonavir with plasma HIV RNA <50 copies/mL were eligible and received intensified therapy with 150 mg of maraviroc twice daily. (1)H-MRS was performed in several cerebral locations, including the right basal ganglia (RBG), to assess CMRs, including N-acetyl aspartate/creatine (NAA/Cr), at baseline and after 14 days. Subsequently, on day 15, blood samples were obtained to determine plasma concentrations of maraviroc pre-dose (C(trough)) and then paired blood and CSF samples were collected at 4 or 6 h post-dose. Associations between maraviroc exposure, clinical parameters and changes to CMRs were evaluated. TRIAL REGISTRY: ClinicalTrials.gov (http://clinicaltrials.gov/ct2/show/NCT00982878). RESULTS: Twelve subjects (75% male) participated with a mean (SD) CD4+ cell count of 503 (199) cells/µL. Mean (SD) maraviroc plasma concentrations at pre-dose, 4 h post-dose and 6 h post-dose were 337 (74), 842 (174) and 485 (100) ng/mL and CSF concentrations at 4 h post-dose and 6 h post-dose were 7.5 (1.3) and 5.1 (1.2) ng/mL. The mean maraviroc CSF : plasma ratio (range) was 1.01% (0.57%-1.61%). An increase of 14.8% was observed for the RBG NAA/Cr ratio, which was significantly associated with higher maraviroc plasma C(trough) (P = 0.05, r = 0.61), but not CSF concentration (P = 0.16, r = 0.46). CONCLUSIONS: After 14 days of maraviroc intensification, small increases in cerebral metabolite markers of neuronal integrity (NAA/Cr ratios) were observed and are associated with maraviroc plasma C(trough).


Assuntos
Fármacos Anti-HIV/farmacocinética , Química Encefálica/efeitos dos fármacos , Encéfalo/efeitos dos fármacos , Antagonistas dos Receptores CCR5 , Cicloexanos/farmacocinética , Infecções por HIV/tratamento farmacológico , Triazóis/farmacocinética , Adulto , Fármacos Anti-HIV/administração & dosagem , Líquido Cefalorraquidiano/química , Cicloexanos/administração & dosagem , Feminino , Humanos , Espectroscopia de Ressonância Magnética , Masculino , Maraviroc , Pessoa de Meia-Idade , Plasma/química , Triazóis/administração & dosagem
14.
HIV Clin Trials ; 13(4): 222-7, 2012.
Artigo em Inglês | MEDLINE | ID: mdl-22849963

RESUMO

BACKGROUND: Cerebrospinal (CSF) fluid biomarkers may be a useful tool for assessing the cerebral effects of antiretroviral therapy. OBJECTIVE: The aim of the study was to investigate the relationship between 4 CSF chemokines with maraviroc exposure and cerebral metabolite ratios (CMR) measured by magnetic resonance spectroscopy (1H-MRS) in HIV-infected individuals following maraviroc intensification. METHODS: CSF concentration of maraviroc and 4 chemokines (MCP-1, IP-10, MCP-4, and MIP-1ß), plasma concentration of maraviroc pre-CSF assessment, and right basal ganglia CMR were assessed in 12 male HIV-infected, neuro-asymptomatic adults after 14 days of antiretroviral therapy intensification with maraviroc 150 mg twice daily. The relationship between CSF analytes with both CMRs and plasma and CSF maraviroc concentrations were examined using Spearman correlation coefficient. RESULTS: Twelve subjects completed study procedures with baseline values as follows: mean (SD) age 42 (8) years, CD4+ cell count 503 (199) cells/µL, and plasma HIV RNA<50 copies/mL in most subjects. Mean (range, pg/mL) chemokine concentrations were IP-10, 1242 (190-8073); MCP-4, 6.52 (1-18); MCP-1, 702 (201-1618); and MIP-1ß, 42 (5-153). IP-10, MCP-4, and MIP-1ß were significantly associated with CMRs in the right basal ganglia with (1) lower concentrations of IP-10 correlating with higher N-acetyl aspartate to creatine ratios (NAA/Cr) and (2) higher concentrations of MCP-4 and MIP-1ß correlating with higher myoinositol to creatine (mI/Cr) ratios. There were no significant associations with MCP-1. Finally lower concentrations of IP-10 were significantly associated with higher maraviroc plasma trough concentration (r=-0.629, P=.028) but not CSF concentration (r=-0.308, P=.331). CONCLUSION: We hypothesize that the relationship between IP-10, MCP-4, and MIP-1ß with maraviroc exposure and CMRs may be associated with a direct cerebral effect of maraviroc.


Assuntos
Antagonistas dos Receptores CCR5 , Quimiocinas/líquido cefalorraquidiano , Cicloexanos/farmacologia , Inibidores da Fusão de HIV/farmacologia , Espectroscopia de Ressonância Magnética/métodos , Triazóis/farmacologia , Adulto , Cicloexanos/metabolismo , Feminino , Inibidores da Fusão de HIV/metabolismo , Humanos , Masculino , Maraviroc , Pessoa de Meia-Idade , Triazóis/metabolismo
15.
Pediatr Res ; 72(1): 63-9, 2012 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-22447318

RESUMO

INTRODUCTION: Objective biomarkers are needed to assess neuroprotective therapies after perinatal hypoxic-ischemic encephalopathy (HIE). We tested the hypothesis that, in infants who underwent therapeutic hypothermia after perinatal HIE, neurodevelopmental performance was predicted by fractional anisotropy (FA) values in the white matter (WM) on early diffusion tensor imaging (DTI) as assessed by means of tract-based spatial statistics (TBSS). METHODS: We studied 43 term infants with HIE. Developmental assessments were carried out at a median (range) age of 24 (12-28) mo. RESULTS: As compared with infants with favorable outcomes, those with unfavorable outcomes had significantly lower FA values (P < 0.05) in the centrum semiovale, corpus callosum (CC), anterior and posterior limbs of the internal capsule, external capsules, fornix, cingulum, cerebral peduncles, optic radiations, and inferior longitudinal fasciculus. In a second analysis in 32 assessable infants, the Griffiths Mental Development Scales (Revised) (GMDS-R) showed a significant linear correlation (P < 0.05) between FA values and developmental quotient (DQ) and all its component subscale scores. DISCUSSION: DTI analyzed by TBSS provides a qualified biomarker that can be used to assess the efficacy of additional neuroprotective therapies after HIE.


Assuntos
Encéfalo/crescimento & desenvolvimento , Desenvolvimento Infantil/fisiologia , Hipotermia Induzida/efeitos adversos , Hipóxia-Isquemia Encefálica/fisiopatologia , Hipóxia-Isquemia Encefálica/terapia , Anisotropia , Biomarcadores , Imagem de Tensor de Difusão , Inglaterra , Feminino , Humanos , Hipotermia Induzida/métodos , Lactente , Testes de Inteligência , Masculino , Técnicas de Rastreamento Neuroanatômico
16.
Neuroradiology ; 54(5): 507-16, 2012 May.
Artigo em Inglês | MEDLINE | ID: mdl-22006424

RESUMO

INTRODUCTION: Our aims were to (1) assess the corticospinal tracts (CSTs) in infants with focal injury and healthy term controls using probabilistic tractography and (2) to correlate the conventional magnetic resonance imaging (MRI) and tractography findings in infants with focal injury with their later motor function. METHODS: We studied 20 infants with focal lesions and 23 controls using MRI and diffusion tensor imaging. Tract volume, fractional anisotropy (FA), apparent diffusion coefficient (ADC) values, axial diffusivity and radial diffusivity (RD) of the CSTs were determined. Asymmetry indices (AIs) were calculated by comparing ipsilateral to contralateral CSTs. Motor outcome was assessed using a standardized neurological examination. RESULTS: Conventional MRI was able to predict normal motor development (n = 9) or hemiplegia (n = 6). In children who developed a mild motor asymmetry (n = 5), conventional MRI predicted a hemiplegia in two and normal motor development in three infants. The AIs for tract volume, FA, ADC and RD showed a significant difference between controls and infants who developed a hemiplegia, and RD also showed a significant difference in AI between controls and infants who developed a mild asymmetry. CONCLUSION: Conventional MRI was able to predict subsequent normal motor development or hemiplegia following focal injury in newborn infants. Measures of RD obtained from diffusion tractography may offer additional information for predicting a subsequent asymmetry in motor function.


Assuntos
Infarto Encefálico/complicações , Isquemia Encefálica/complicações , Imagem de Tensor de Difusão/métodos , Hemiplegia/etiologia , Hemiplegia/fisiopatologia , Destreza Motora/fisiologia , Tratos Piramidais/lesões , Acidente Vascular Cerebral/complicações , Anisotropia , Estudos de Casos e Controles , Feminino , Humanos , Interpretação de Imagem Assistida por Computador , Imageamento Tridimensional , Lactente , Masculino , Exame Neurológico , Valor Preditivo dos Testes
17.
Dev Cogn Neurosci ; 54: 101103, 2022 04.
Artigo em Inglês | MEDLINE | ID: mdl-35364447

RESUMO

Developmental delays in infanthood often persist, turning into life-long difficulties, and coming at great cost for the individual and community. By examining the developing brain and its relation to developmental outcomes we can start to elucidate how the emergence of brain circuits is manifested in variability of infant motor, cognitive and behavioural capacities. In this study, we examined if cortical structural covariance at birth, indexing coordinated development, is related to later infant behaviour. We included 193 healthy term-born infants from the Developing Human Connectome Project (dHCP). An individual cortical connectivity matrix derived from morphological and microstructural features was computed for each subject (morphometric similarity networks, MSNs) and was used as input for the prediction of behavioural scores at 18 months using Connectome-Based Predictive Modeling (CPM). Neonatal MSNs successfully predicted social-emotional performance. Predictive edges were distributed between and within known functional cortical divisions with a specific important role for primary and posterior cortical regions. These results reveal that multi-modal neonatal cortical profiles showing coordinated maturation are related to developmental outcomes and that network organization at birth provides an early infrastructure for future functional skills.


Assuntos
Conectoma , Imageamento por Ressonância Magnética , Encéfalo , Conectoma/métodos , Humanos , Lactente , Comportamento do Lactente , Recém-Nascido
18.
Front Neurosci ; 16: 886772, 2022.
Artigo em Inglês | MEDLINE | ID: mdl-35677357

RESUMO

The Developing Human Connectome Project has created a large open science resource which provides researchers with data for investigating typical and atypical brain development across the perinatal period. It has collected 1228 multimodal magnetic resonance imaging (MRI) brain datasets from 1173 fetal and/or neonatal participants, together with collateral demographic, clinical, family, neurocognitive and genomic data from 1173 participants, together with collateral demographic, clinical, family, neurocognitive and genomic data. All subjects were studied in utero and/or soon after birth on a single MRI scanner using specially developed scanning sequences which included novel motion-tolerant imaging methods. Imaging data are complemented by rich demographic, clinical, neurodevelopmental, and genomic information. The project is now releasing a large set of neonatal data; fetal data will be described and released separately. This release includes scans from 783 infants of whom: 583 were healthy infants born at term; as well as preterm infants; and infants at high risk of atypical neurocognitive development. Many infants were imaged more than once to provide longitudinal data, and the total number of datasets being released is 887. We now describe the dHCP image acquisition and processing protocols, summarize the available imaging and collateral data, and provide information on how the data can be accessed.

19.
Radiology ; 258(1): 229-35, 2011 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-20980451

RESUMO

PURPOSE: To prospectively evaluate the clinical effectiveness of snapshot inversion recovery (SNAPIR), which is a dedicated optimized inversion-recovery-prepared single-shot fast spin-echo T1-weighted sequence, in the delineation of normal fetal brain anatomy compared with that of the currently used T1-weighted gradient-echo protocol, which often yields images of poor quality due to motion artifacts and inadequate contrast. MATERIALS AND METHODS: This study was approved by the hospital research ethics committee, and informed written consent was obtained from all patients. Forty-one fetuses were examined at 19-37 weeks gestation (mean, 29 weeks gestation) by using both the standard T1-weighted protocol and the optimized T1-weighted SNAPIR protocol with a 1.5-T imager. Two independent blinded observers performed qualitative analysis, evaluating overall diagnostic quality, detailed anatomic delineation, and severity of motion artifacts. Quantitative analysis comprised calculation of contrast ratios (CRs) for the cortical gray matter, subplate, white matter, and cerebrospinal fluid. The Wilcoxon signed rank test was used to compare image rating scores, the paired t test was used to compare CRs, and κ statistics were used to test interobserver agreement. RESULTS: Both overall diagnostic quality (P < .001) and detailed anatomic delineation (P < .001) were enhanced with SNAPIR compared with the standard T1-weighted acquisition. Also, motion artifacts were less severe (P = .008) and less extensive (P < .001) with SNAPIR. Corresponding CRs were increased with SNAPIR in seven of eight examined regions. CONCLUSION: SNAPIR is a promising robust alternative to the current T1-weighted acquisitions; its role in the detection of disease requires further study.


Assuntos
Doenças Fetais/diagnóstico , Aumento da Imagem/métodos , Imageamento por Ressonância Magnética/métodos , Diagnóstico Pré-Natal/métodos , Artefatos , Feminino , Idade Gestacional , Humanos , Interpretação de Imagem Assistida por Computador/métodos , Gravidez , Estudos Prospectivos , Estatísticas não Paramétricas
20.
Am J Obstet Gynecol ; 205(5): 483.e1-8, 2011 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-21861969

RESUMO

OBJECTIVE: The purpose of this study was to investigate alterations in brain metabolism in fetuses with intrauterine growth restriction (IUGR) and evidence of cerebral redistribution of blood flow. STUDY DESIGN: Biometry and Doppler assessment of blood flow was assessed with ultrasound in 28 fetuses with IUGR and cerebral redistribution and in 41 appropriately grown control subjects. Proton magnetic resonance spectroscopy of the fetal brain was then performed to determine the presence of choline (Cho), creatine (Cr), N-acetylaspartate (NAA), and lactate and to generate ratios for NAA:Cho, NAA:Cr, and Cho:Cr. RESULTS: Sixty-five percent of spectra were interpretable: N-acetylaspartate, choline, and creatine peaks were identified in all these spectra; lactate was present in 5 IUGR fetuses and in 3 appropriately grown fetuses. NAA:Cr and NAA:Cho ratios were significantly lower in IUGR fetuses with cerebral redistribution. CONCLUSION: Cerebral redistribution is associated with altered brain metabolism that is evidenced by a reduction in NAA:Cho and NAA:Cr ratios.


Assuntos
Encéfalo/metabolismo , Retardo do Crescimento Fetal/metabolismo , Adolescente , Adulto , Encéfalo/embriologia , Feminino , Humanos , Espectroscopia de Ressonância Magnética , Gravidez
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