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1.
Dev Neurosci ; 2024 May 13.
Article in English | MEDLINE | ID: mdl-38740013

ABSTRACT

BACKGROUND: Fetal growth restriction (FGR) corresponds to the fetus's inability to achieve an adequate weight gain based on genetic potential and gestational age. It is an important cause of morbidity and mortality. SUMMARY: In this review we address the challenges of diagnosis and classification of FGR. We review how chronic fetal hypoxia impacts brain development. We describe recent advances on placental and fetal brain imaging using MRI and how they offer new non-invasive means to study growth restriction in humans. We go on to review the impact of FGR on brain integrity in the neonatal period, later childhood, and adulthood and review available therapies. KEY MESSAGES: Fetal growth restriction consequences are not limited to the perinatal period. We hypothesize that impaired brain reserve, as defined by structure and size, may predict some concerning epidemiological data of impaired cognitive outcomes and dementia with aging in this group of patients.

2.
J Neuroinflammation ; 20(1): 241, 2023 Oct 20.
Article in English | MEDLINE | ID: mdl-37864272

ABSTRACT

BACKGROUND: Perinatal infection/inflammation is associated with a high risk for neurological injury and neurodevelopmental impairment after birth. Despite a growing preclinical evidence base, anti-inflammatory interventions have not been established in clinical practice, partly because of the range of potential targets. We therefore systematically reviewed preclinical studies of immunomodulation to improve neurological outcomes in the perinatal brain and assessed their therapeutic potential. METHODS: We reviewed relevant studies published from January 2012 to July 2023 using PubMed, Medline (OvidSP) and EMBASE databases. Studies were assessed for risk of bias using the SYRCLE risk of bias assessment tool (PROSPERO; registration number CRD42023395690). RESULTS: Forty preclinical publications using 12 models of perinatal neuroinflammation were identified and divided into 59 individual studies. Twenty-seven anti-inflammatory agents in 19 categories were investigated. Forty-five (76%) of 59 studies reported neuroprotection, from all 19 categories of therapeutics. Notably, 10/10 (100%) studies investigating anti-interleukin (IL)-1 therapies reported improved outcome, whereas half of the studies using corticosteroids (5/10; 50%) reported no improvement or worse outcomes with treatment. Most studies (49/59, 83%) did not control core body temperature (a known potential confounder), and 25 of 59 studies (42%) did not report the sex of subjects. Many studies did not clearly state whether they controlled for potential study bias. CONCLUSION: Anti-inflammatory therapies are promising candidates for treatment or even prevention of perinatal brain injury. Our analysis highlights key knowledge gaps and opportunities to improve preclinical study design that must be addressed to support clinical translation.


Subject(s)
Anti-Inflammatory Agents , Neuroprotection , Pregnancy , Animals , Female , Humans , Brain
3.
Front Mol Neurosci ; 16: 1323449, 2023.
Article in English | MEDLINE | ID: mdl-38163061

ABSTRACT

Introduction: Chronic progressive neuroinflammation is a hallmark of neurological lysosomal storage diseases, including mucopolysaccharidosis III (MPS III or Sanfilippo disease). Since neuroinflammation is linked to white matter tract pathology, we analyzed axonal myelination and white matter density in the mouse model of MPS IIIC HgsnatP304L and post-mortem brain samples of MPS III patients. Methods: Brain and spinal cord tissues of human MPS III patients, 6-month-old HgsnatP304L mice and age- and sex-matching wild type mice were analyzed by immunofluorescence to assess levels of myelin-associated proteins, primary and secondary storage materials, and levels of microgliosis. Corpus callosum (CC) region was studied by transmission electron microscopy to analyze axon myelination and morphology of oligodendrocytes and microglia. Mouse brains were analyzed ex vivo by high-filed MRI using Diffusion Basis Spectrum Imaging in Python-Diffusion tensor imaging algorithms. Results: Analyses of CC and spinal cord tissues by immunohistochemistry revealed substantially reduced levels of myelin-associated proteins including Myelin Basic Protein, Myelin Associated Glycoprotein, and Myelin Oligodendrocyte Glycoprotein. Furthermore, ultrastructural analyses revealed disruption of myelin sheath organization and reduced myelin thickness in the brains of MPS IIIC mice and human MPS IIIC patients compared to healthy controls. Oligodendrocytes (OLs) in the CC of MPS IIIC mice were scarce, while examination of the remaining cells revealed numerous enlarged lysosomes containing heparan sulfate, GM3 ganglioside or "zebra bodies" consistent with accumulation of lipids and myelin fragments. In addition, OLs contained swollen mitochondria with largely dissolved cristae, resembling those previously identified in the dysfunctional neurons of MPS IIIC mice. Ex vivo Diffusion Basis Spectrum Imaging revealed compelling signs of demyelination (26% increase in radial diffusivity) and tissue loss (76% increase in hindered diffusivity) in CC of MPS IIIC mice. Discussion: Our findings demonstrate an important role for white matter injury in the pathophysiology of MPS III. This study also defines specific parameters and brain regions for MRI analysis and suggests that it may become a crucial non-invasive method to evaluate disease progression and therapeutic response.

4.
Behav Brain Res ; 428: 113884, 2022 06 25.
Article in English | MEDLINE | ID: mdl-35398230

ABSTRACT

Magnetic resonance imaging (MRI) is currently under investigation as a non-invasive tool to monitor neurodevelopmental trajectories and predict risk of cognitive deficits following white matter injury (WMI) in very preterm infants. In the present study, we evaluated the capacity of multimodal MRI (high-resolution T2-weighted imaging and diffusion tensor imaging)to assess changes following WMI and their relationship to learning and memory performance in Wistar rats as it has been demonstrated for preterm infants. Multimodal MRI performed at P31-P32 shown that animals exposed to neonatal LPS could be classified into two groups: minimal and overt injury. Animals with overt injury had significantly enlarged ventricles, hippocampal atrophy, diffusivity changes in hippocampal white and gray matter, in the striatum and the cortex. Following neonatal LPS exposure, animals presented learning and memory impairments as shown at the fear conditioning test at P36-P38. The severity of learning and memory deficits was related to increased mean diffusivity in the hippocampal region. In conclusion, non-invasive multimodal MRI (volumetric and DTI) assessed and classified the extent of injury at long-term following neonatal LPS exposure. Microstructural changes in the hippocampus at DTI were associated to learning and memory impairments. This further highlights the utility of multimodal MRI as a non-invasive quantitative biomarker following perinatal inflammation.


Subject(s)
Brain Injuries , White Matter , Animals , Brain/diagnostic imaging , Brain Injuries/pathology , Diffusion Tensor Imaging/methods , Female , Humans , Infant, Newborn , Infant, Premature , Inflammation/chemically induced , Inflammation/diagnostic imaging , Inflammation/pathology , Lipopolysaccharides , Magnetic Resonance Imaging/methods , Memory Disorders/diagnostic imaging , Memory Disorders/etiology , Memory Disorders/pathology , Pregnancy , Rats , Rats, Wistar , White Matter/diagnostic imaging , White Matter/pathology
6.
Int J Dev Neurosci ; 82(3): 243-260, 2022 May.
Article in English | MEDLINE | ID: mdl-35315121

ABSTRACT

INTRODUCTION: Inflammation-induced white matter injury (WMI) in preterm infants is characterized by microglia activation, astrogliosis, oxidative stress and neurodevelopmental impairments. Microglia and astrocytes activation can be described under a broad spectrum of activation profile with extremes described as pro-inflammatory/neurotoxic (M1 microglia or A1 astrocyte) or anti-inflammatory/neuroprotective (M2 microglia or A2 astrocyte) in response to stimuli including lipopolysaccharide (LPS) and interleukin 1 (IL-1). As IL-1 signalling pathway has been posited as a major driver of inflammation-induced perinatal WMI, our aim was to evaluate the contribution of IL-1 modulation in LPS-induced microglia and astrocyte activation. METHODS: Primary neonatal cell co-cultures of astrocytes and microglia were treated with LPS (100 ng/ml) for 8 h or 24 h. Two distinct IL-1 receptor antagonists, Rytvela or Kineret (1 µg/ml), were added simultaneously with LPS to respectively modulate or block IL-1 receptor. Medium was collected to measure levels of IL-1ß. Expression of markers related to pro- and anti-inflammatory microglia and astrocyte activation profiles and antioxidant genes were assessed. RESULTS: At 8 h, LPS exposure induced pro- (M1/A1) and anti-inflammatory (M2/A2) marker expression and inhibited antioxidant gene expression in microglia and astrocytes. By 24 h, continuous LPS exposure increased pro-inflammatory and neurotoxic microglial and astrocytic markers (M1/A1), as well as antioxidant genes. Administration of IL-1 antagonists Rytvela and Kineret with continuous LPS exposure had no significant effect on modulation of specific microglia and astrocyte activation pathways. DISCUSSION/CONCLUSION: We show that LPS effects on in vitro neonatal microglia and astrocytes co-cultures are time dependent eliciting a number of pro- and anti-inflammatory responses during the acute phase of inflammation (8 h), which shift towards pro-inflammatory and neurotoxic factors by 24 h. Although LPS-induced inflammation led to abundant IL-1 expression, IL-1 inhibition had no significant impact on in vitro modulation of microglia and astrocyte activation pathways towards M2 and A2 activation profile.


Subject(s)
Lipopolysaccharides , Neurotoxicity Syndromes , Anti-Inflammatory Agents/metabolism , Anti-Inflammatory Agents/pharmacology , Anti-Inflammatory Agents/therapeutic use , Antioxidants/metabolism , Astrocytes/metabolism , Cells, Cultured , Female , Humans , Infant, Newborn , Infant, Premature , Inflammation/metabolism , Interleukin 1 Receptor Antagonist Protein/metabolism , Interleukin 1 Receptor Antagonist Protein/pharmacology , Interleukin 1 Receptor Antagonist Protein/therapeutic use , Lipopolysaccharides/toxicity , Microglia/metabolism , Neuroinflammatory Diseases , Pregnancy , Receptors, Interleukin-1/metabolism , Receptors, Interleukin-1/therapeutic use
7.
Am J Perinatol ; 39(3): 298-306, 2022 02.
Article in English | MEDLINE | ID: mdl-32854133

ABSTRACT

OBJECTIVE: This study aimed to assess whether the hospital level of care where asphyxiated neonates treated with hypothermia were originally born influences their outcome. STUDY DESIGN: We conducted a retrospective cohort study of all asphyxiated neonates treated with hypothermia in a large metropolitan area. Birth hospitals were categorized based on provincially predefined levels of care. Primary outcome was defined as death and/or brain injury on brain magnetic resonance imaging (adverse outcome) and was compared according to the hospital level of care. RESULTS: The overall incidence of asphyxiated neonates treated with hypothermia significantly decreased as hospital level of care increased: 1 per 1,000 live births (109/114,627) in level I units; 0.9 per 1,000 live births (73/84,890) in level II units; and 0.7 per 1,000 live births (51/71,093) in level III units (p < 0.001). The rate of emergent cesarean sections and the initial pH within the first hour of life were significantly lower in level I and level II units compared with level III units (respectively, p < 0.001 and p = 0.002). In a multivariable analysis adjusting for the rates of emergent cesarean sections and initial pH within the first hour of life, being born in level I units was confirmed as an independent predictor of adverse outcome (adjusted odds ratio [OR] level I vs. level III 95% confidence interval [CI]: 2.13 [1.02-4.43], p = 0.04) and brain injury (adjusted OR level I vs. level III 95% CI: 2.41 [1.12-5.22], p = 0.02). CONCLUSION: Asphyxiated neonates born in level I units and transferred for hypothermia treatment were less often born by emergent cesarean sections, had worse pH values within the first hour of life, and had a higher incidence of adverse outcome and brain injury compared with neonates born in level III units. Further work is needed to optimize the initial management of these neonates to improve outcomes, regardless of the location of their hospital of birth. KEY POINTS: · The incidence of asphyxiated neonates treated with hypothermia varied by hospital level of care.. · Their rates of emergent cesarean sections and their initial pH within the first hour of life varied by hospital level of care.. · The hospital level of care was an independent predictor of their adverse outcome, defined as death and/or brain injury on brain MRI..


Subject(s)
Asphyxia Neonatorum/therapy , Hypothermia, Induced , Cesarean Section/statistics & numerical data , Child Health Services , Female , Humans , Hydrogen-Ion Concentration , Infant, Newborn , Intensive Care Units, Neonatal , Male , Patient Transfer , Retrospective Studies , Treatment Outcome
8.
Acta Biomater ; 139: 296-306, 2022 02.
Article in English | MEDLINE | ID: mdl-34365040

ABSTRACT

Flexible, self-healing and adhesive conductive materials with Young's modulus matching biological tissues are highly desired for applications in bioelectronics. Here, we report self-healing, stretchable, highly adhesive and conductive hydrogels obtained by mixing polyvinyl alcohol, sodium tetraborate and a screen printing paste containing the conducting polymer Poly (3,4-ethylenedioxythiophene) doped with polystyrene sulfonate (PEDOT:PSS) and diol additives. The as prepared hydrogels exhibited modelling ability, high adhesion on pig skin (1.96 N/cm2), high plastic stretchability (>10000%), a moderate conductivity, a low compressive modulus (0.3-3.7 KPa), a good strain sensitivity (gauge factor = 3.88 at 500% strain), and remarkable self-healing properties. Epidermal patch electrodes prepared using one of our hydrogels demonstrated high-quality recording of electrocardiography (ECG) and electromyography (EMG) signal. Because of their straightforward fabrication, outstanding mechanical properties and possibility to combine the electrode components in a single material, hydrogels based on PVA, borax and PEDOT:PSS are highly promising for applications in bioelectronics and wearable electronics. STATEMENT OF SIGNIFICANCE: Soft materials with electrical conductivity are investigated for healthcare applications, such as electrodes to measure vital signs that can easily adapt to the shape and the movements of human skin. Conductive hydrogels (i.e. gels containing water) are ideal materials for this purpose due softness and flexibility. In this this work, we report hydrogels obtained mixing an electrically conductive polymer, a water-soluble biocompatible polymer and a salt. These materials show high adhesion on skin, electrical conductivity and ability to self-repair after a mechanical damage. These hydrogels were successfully used to fabricate electrode to measure cardiac and muscular electrical signals.


Subject(s)
Adhesives , Hydrogels , Animals , Electric Conductivity , Electrodes , Polyvinyl Alcohol , Swine
9.
Front Pediatr ; 9: 689190, 2021.
Article in English | MEDLINE | ID: mdl-34327181

ABSTRACT

Objectives: Significant resources are devoted to neonatal prolonged mechanical ventilation (NPMV), but little is known about the outcomes in those children. Our primary objective was to describe the NPMV respiratory, digestive, and neurological outcomes at 18 months corrected age. Our second objective was on the early identification of which patients, among the NPMV cohort, will need to be ventilated for ≥125 days, which corresponded to the 75th percentile in the preliminary data, and to describe that subgroup. Methods: In this retrospective cohort study, we included all children born between 2004 and 2013 who had a NPMV (≥21 days of invasive or noninvasive respiratory support reached between 40 and 44 weeks of postconceptional age). We used random forests, logistic regression with penalization, naive Bayes, and XGBoost to predict which patients will need ≥125 days of ventilation. We used a Monte Carlo cross validation. Results: We included 164 patients. Of which, 40% (n = 66) were female, and the median gestational age was 29 weeks [interquartile range (IQR): 26-36 weeks] with a bimodal distribution. Median ventilation days were 104 (IQR: 66-139 days). The most frequently associated diagnoses were pulmonary hypertension (43%), early pulmonary dysplasia (41%), and lobar emphysema (37%). At 18 months corrected age, 29% (n = 47) had died, 59% (n = 97) were free of any respiratory support, and 45% (n = 74) were exclusively orally fed. A moderate area under the ROC curve of 0.65 (95% CI: 0.54-0.72) for identifying patients in need of ≥125 days of ventilation at inclusion was achieved by random forests classifiers. Among the 26 measured at inclusion, the most contributive ones were PCO2, inspired O2 concentration, and gestational age. At 18 months corrected age, patients ventilated for ≥125 days had a lower respiratory weaning success (76 vs. 87%, P = 0.05), lower exclusive oral feeding proportion (51 vs. 84%, P < 0.001), and a higher neurological impairment (median Pediatric Cerebral Performance Category score 3 vs. 2, P = 0.008) than patients ventilated for < 125 days. Conclusion: NPMV is a severe condition with a high risk of mortality, neurological impairment, and oral feed delay at 18 months. Most survivors are weaned of any respiratory support. We identified the risk factors that allow for the early identification of the most at-risk children of long-term ventilation with a moderate discrimination.

10.
Front Neurosci ; 14: 207, 2020.
Article in English | MEDLINE | ID: mdl-32273836

ABSTRACT

INTRODUCTION: Deep learning neural networks are especially potent at dealing with structured data, such as images and volumes. Both modified LiviaNET and HyperDense-Net performed well at a prior competition segmenting 6-month-old infant magnetic resonance images, but neonatal cerebral tissue type identification is challenging given its uniquely inverted tissue contrasts. The current study aims to evaluate the two architectures to segment neonatal brain tissue types at term equivalent age. METHODS: Both networks were retrained over 24 pairs of neonatal T1 and T2 data from the Developing Human Connectome Project public data set and validated on another eight pairs against ground truth. We then reported the best-performing model from training and its performance by computing the Dice similarity coefficient (DSC) for each tissue type against eight test subjects. RESULTS: During the testing phase, among the segmentation approaches tested, the dual-modality HyperDense-Net achieved the best statistically significantly test mean DSC values, obtaining 0.94/0.95/0.92 for the tissue types and took 80 h to train and 10 min to segment, including preprocessing. The single-modality LiviaNET was better at processing T2-weighted images than processing T1-weighted images across all tissue types, achieving mean DSC values of 0.90/0.90/0.88 for gray matter, white matter, and cerebrospinal fluid, respectively, while requiring 30 h to train and 8 min to segment each brain, including preprocessing. DISCUSSION: Our evaluation demonstrates that both neural networks can segment neonatal brains, achieving previously reported performance. Both networks will be continuously retrained over an increasingly larger repertoire of neonatal brain data and be made available through the Canadian Neonatal Brain Platform to better serve the neonatal brain imaging research community.

11.
FASEB J ; 34(1): 432-445, 2020 01.
Article in English | MEDLINE | ID: mdl-31914673

ABSTRACT

Preterm infants are vulnerable to inflammation-induced white matter injury (WMI), which is associated with neurocognitive impairment and increased risk of neuropsychiatric diseases in adulthood. Epigenetic mechanisms, particularly DNA methylation, play a role in normal development and modulate the response to pathological challenges. Our aims were to determine how WMI triggered DNA methylation alterations in brains of neonatal rats and if such changes persisted over time. We used a robust model of WMI by injecting lipopolysaccharide (LPS) or sterile saline in the corpus callosum of 3-day-old (P3) rat pups. Brains were collected 24 hours (P4) and 21 days post-injection (P24). We extracted genomic DNA from the brain to establish genome-wide quantitative DNA methylation profiles using reduced representation bisulfite sequencing. Neonatal LPS exposure induced a persistent increased methylation of genes related to nervous system development and a reduced methylation of genes associated with inflammatory pathways. These findings suggest that early-life neuroinflammatory exposure impacts the cerebral methylation landscape with determining widespread epigenetic modifications especially in genes related to neurodevelopment.


Subject(s)
Brain Diseases/pathology , DNA Methylation , Disease Models, Animal , Epigenesis, Genetic , Inflammation/complications , Animals , Animals, Newborn , Brain Diseases/etiology , Brain Diseases/genetics , Female , Inflammation/genetics , Inflammation/pathology , Lipopolysaccharides/toxicity , Male , Rats , Rats, Sprague-Dawley
12.
Brain Behav Immun ; 81: 348-360, 2019 10.
Article in English | MEDLINE | ID: mdl-31247289

ABSTRACT

Perinatal infection and inflammatory episodes in preterm infants are associated with diffuse white matter injury (WMI) and adverse neurological outcomes. Inflammation-induced WMI was previously shown to be linked with later hippocampal atrophy as well as learning and memory impairments in preterm infants. Early evaluation of injury load and therapeutic response with non-invasive tools such as multimodal magnetic resonance imaging (MRI) would greatly improve the search of new therapeutic approaches in preterm infants. Our aim was to evaluate the potential of multimodal MRI to detect the response of interleukin-1 receptor antagonist (IL-1Ra) treatment, known for its neuroprotective properties, during the acute phase of injury on a model of neonatal WMI. Rat pups at postnatal day 3 (P3) received intracerebral injection of lipopolysaccharide with systemic IL-1Ra therapy. 24 h later (P4), rats were imaged with multimodal MRI to assess microstructure by diffusion tensor imaging (DTI) and neurochemical profile of the hippocampus with 1H-magnetic resonance spectroscopy. Astrocyte and microglial activation, apoptosis and the mRNA expression of pro-inflammatory and necroptotic markers were assessed. During the acute phase of injury, neonatal LPS exposure altered the concentration of hippocampus metabolites related to neuronal integrity, neurotransmission and membrane integrity and induced diffusivity restriction. Just 24 h after initiation of therapy, early indication of IL-1Ra neuroprotective effect could be detected in vivo by non-invasive spectroscopy and DTI, and confirmed with immunohistochemical evaluation and mRNA expression of inflammatory markers and cell death. In conclusion, multimodal MRI, particularly DTI, can detect not only injury but also the acute therapeutic effect of IL-1Ra suggesting that MRI could be a useful non-invasive tool to follow, at early time points, the therapeutic response in preterm infants.


Subject(s)
Multimodal Imaging/methods , White Matter/diagnostic imaging , White Matter/physiopathology , Animals , Animals, Newborn , Brain/drug effects , Brain Injuries/complications , Brain Injuries/diagnostic imaging , Diffusion Magnetic Resonance Imaging/methods , Diffusion Tensor Imaging/methods , Female , Hippocampus/drug effects , Inflammation/complications , Lipopolysaccharides/administration & dosage , Lipopolysaccharides/pharmacology , Magnetic Resonance Imaging/methods , Magnetic Resonance Spectroscopy/methods , Male , Neuroprotective Agents/pharmacology , Pregnancy , Rats , Rats, Sprague-Dawley , Receptors, Interleukin-1/antagonists & inhibitors , Receptors, Interleukin-1/metabolism
13.
Int J Dev Neurosci ; 77: 77-88, 2019 Oct.
Article in English | MEDLINE | ID: mdl-31054925

ABSTRACT

With increasing advances in the field of medical brain imaging, the known spectrum of white matter lesions has expanded, and we can now assess the presence of punctate white matter lesions (PWML). These focal small lesions are quite frequently detected in the preterm infant and in full-term infants with congenital heart malformations with, some studies reporting a link between these lesions and adverse long-term outcomes. The etiology of PWML has sparked a lot of questions over the years, some of which still remain unanswered. This narrative review will bring an overview of current knowledge and their significant clinical importance in the newborn brain.


Subject(s)
Brain/pathology , Infant, Premature, Diseases/pathology , White Matter/pathology , Brain/diagnostic imaging , Female , Humans , Infant, Newborn , Infant, Premature , Infant, Premature, Diseases/diagnostic imaging , Magnetic Resonance Imaging , Male , White Matter/diagnostic imaging
14.
Hum Brain Mapp ; 40(4): 1290-1297, 2019 03.
Article in English | MEDLINE | ID: mdl-30467922

ABSTRACT

Quality control (QC) of brain magnetic resonance images (MRI) is an important process requiring a significant amount of manual inspection. Major artifacts, such as severe subject motion, are easy to identify to naïve observers but lack automated identification tools. Clinical trials involving motion-prone neonates typically pool data to obtain sufficient power, and automated quality control protocols are especially important to safeguard data quality. Current study tested an open source method to detect major artifacts among 2D neonatal MRI via supervised machine learning. A total of 1,020 two-dimensional transverse T2-weighted MRI images of preterm newborns were examined and classified as either QC Pass or QC Fail. Then 70 features across focus, texture, noise, and natural scene statistics categories were extracted from each image. Several different classifiers were trained and their performance was compared with subjective rating as the gold standard. We repeated the rating process again to examine the stability of the rating and classification. When tested via 10-fold cross validation, the random undersampling and adaboost ensemble (RUSBoost) method achieved the best overall performance for QC Fail images with 85% positive predictive value along with 75% sensitivity. Similar classification performance was observed in the analyses of the repeated subjective rating. Current results served as a proof of concept for predicting images that fail quality control using no-reference objective image features. We also highlighted the importance of evaluating results beyond mere accuracy as a performance measure for machine learning in imbalanced group settings due to larger proportion of QC Pass quality images.


Subject(s)
Artifacts , Image Interpretation, Computer-Assisted/standards , Image Processing, Computer-Assisted/standards , Magnetic Resonance Imaging/standards , Quality Control , Supervised Machine Learning , Datasets as Topic , Female , Humans , Image Interpretation, Computer-Assisted/methods , Image Processing, Computer-Assisted/methods , Infant, Newborn , Magnetic Resonance Imaging/methods , Male
15.
J Neuroinflammation ; 15(1): 336, 2018 Dec 05.
Article in English | MEDLINE | ID: mdl-30518374

ABSTRACT

BACKGROUND: The extension of sepsis encompassing the preterm newborn's brain is often overlooked due to technical challenges in this highly vulnerable population, yet it leads to substantial long-term neurodevelopmental disabilities. In this study, we demonstrate how neonatal neuroinflammation following postnatal E. coli lipopolysaccharide (LPS) exposure in rat pups results in persistent reduction in sialylation of cerebral glycoproteins. METHODS: Male Sprague-Dawley rat pups at postnatal day 3 (P3) were injected in the corpus callosum with saline or LPS. Twenty-four hours (P4) or 21 days (P24) following injection, brains were extracted and analyzed for neuraminidase activity and expression as well as for sialylation of cerebral glycoproteins and glycolipids. RESULTS: At both P4 and P24, we detected a significant increase of the acidic neuraminidase activity in LPS-exposed rats. It correlated with significantly increased neuraminidase 1 (Neu1) mRNA in LPS-treated brains at P4 and with neuraminidases 1 and 4 at P24 suggesting that these enzymes were responsible for the rise of neuraminidase activity. At both P4 and P24, sialylation of N-glycans on brain glycoproteins decreased according to both mass-spectrometry analysis and lectin blotting, but the ganglioside composition remained intact. Finally, at P24, analysis of brain tissues by immunohistochemistry showed that neurons in the upper layers (II-III) of somatosensory cortex had a reduced surface content of polysialic acid. CONCLUSIONS: Together, our data demonstrate that neonatal LPS exposure results in specific and sustained induction of Neu1 and Neu4, causing long-lasting negative changes in sialylation of glycoproteins on brain cells. Considering the important roles played by sialoglycoproteins in CNS function, we speculate that observed re-programming of the brain sialome constitutes an important part of pathophysiological consequences in perinatal infectious exposure.


Subject(s)
Cerebral Cortex/metabolism , Encephalitis/pathology , Gene Expression Regulation, Developmental/physiology , Glycoproteins/metabolism , Neuraminidase/metabolism , Age Factors , Animals , Animals, Newborn , Cerebral Cortex/drug effects , Corpus Callosum/drug effects , Disease Models, Animal , Encephalitis/chemically induced , Gene Expression Regulation, Developmental/drug effects , Lectins/metabolism , Lipopolysaccharides/toxicity , Male , Neuraminidase/genetics , Phosphopyruvate Hydratase/metabolism , RNA, Messenger/metabolism , Rats , Rats, Sprague-Dawley , Sialic Acids/metabolism
16.
J Magn Reson ; 292: 149-154, 2018 07.
Article in English | MEDLINE | ID: mdl-29731237

ABSTRACT

Aside from injury identification, MRI of the newborn brain has given us insight into cortical and white matter development, identified windows of vulnerabilities, enabled the introduction of therapeutic hypothermia which has become the standard of care in neonatal asphyxia, and is fostering leapfrogging discoveries in the field of neuro-genetics. This article reviews the main advances in recent years in newborn brain imaging both in preclinical and clinical research.


Subject(s)
Brain/diagnostic imaging , Infant, Newborn, Diseases/diagnostic imaging , Infant, Newborn , Magnetic Resonance Imaging/methods , Adult , Animals , Animals, Newborn , Female , Humans , Pregnancy
18.
NMR Biomed ; 30(11)2017 Nov.
Article in English | MEDLINE | ID: mdl-28841761

ABSTRACT

Automated analysis of diffusion tensor imaging (DTI) data is an appealing way to process large datasets in an unbiased manner. However, automation can sometimes be linked to a lack of interpretability. Two whole-brain, automated and voxelwise methods exist: voxel-based analysis (VBA) and tract-based spatial statistics (TBSS). In VBA, the amount of smoothing has been shown to influence the results. TBSS is free of this step, but a projection procedure is introduced to correct for residual misalignments. This projection assigns the local highest fractional anisotropy (FA) value to the mean FA skeleton, which represents white matter tract centers. For both methods, the normalization procedure has a major impact. These issues are well documented in humans but, to our knowledge, not in rodents. In this study, we assessed the quality of three different registration algorithms (ANTs SyN, DTI-TK and FNIRT) using study-specific templates and their impact on automated analysis methods (VBA and TBSS) in a rat pup model of diffuse white matter injury presenting large unilateral deformations. VBA and TBSS results were stable and anatomically coherent across the three pipelines. For VBA, in regions around the large deformations, interpretability was limited because of the increased partial volume effect. With TBSS, two of the three pipelines found a significant decrease in axial diffusivity (AD) at the known injury site. These results demonstrate that automated voxelwise analyses can be used in an animal model with large deformations.


Subject(s)
Diffusion Tensor Imaging/methods , Leukomalacia, Periventricular/diagnostic imaging , Algorithms , Animals , Disease Models, Animal , Rats , Rats, Sprague-Dawley , White Matter
19.
Front Neurosci ; 11: 358, 2017.
Article in English | MEDLINE | ID: mdl-28725174

ABSTRACT

Very preterm newborns have an increased risk of developing an inflammatory cerebral white matter injury that may lead to severe neuro-cognitive impairment. In this study we performed functional connectivity (fc) analysis using resting-state optical imaging of intrinsic signals (rs-OIS) to assess the impact of inflammation on resting-state networks (RSN) in a pre-clinical model of perinatal inflammatory brain injury. Lipopolysaccharide (LPS) or saline injections were administered in postnatal day (P3) rat pups and optical imaging of intrinsic signals were obtained 3 weeks later. (rs-OIS) fc seed-based analysis including spatial extent were performed. A support vector machine (SVM) was then used to classify rat pups in two categories using fc measures and an artificial neural network (ANN) was implemented to predict lesion size from those same fc measures. A significant decrease in the spatial extent of fc statistical maps was observed in the injured group, across contrasts and seeds (*p = 0.0452 for HbO2 and **p = 0.0036 for HbR). Both machine learning techniques were applied successfully, yielding 92% accuracy in group classification and a significant correlation r = 0.9431 in fractional lesion volume prediction (**p = 0.0020). Our results suggest that fc is altered in the injured newborn brain, showing the long-standing effect of inflammation.

20.
Early Hum Dev ; 110: 44-49, 2017 07.
Article in English | MEDLINE | ID: mdl-28544954

ABSTRACT

BACKGROUND: Being born small for gestational age has been associated with neurodevelopmental disabilities and smaller gray matter volumes in childhood. However, it is not known if these changes persist in adults and whether SGA has any impact on attention memory and IQ. AIMS: The goal of this study was to evaluate the association between birth weight and gray matter anatomy in adults born small for gestational age at term, in relation to IQ, attention and memory. MATERIALS AND METHODS: This prospective follow-up study at age 20 included 39 adults born small for gestational age at term and 37 adults born appropriate for gestational age at term. Detailed neurocognitive skills were assessed (IQ, attention and memory). Anatomical images were analyzed using Voxel-Based-Morphometry and FreeSurfer. RESULTS: Adults born small for gestational age at term had lower performances in subtests assessing attention and executive functions. They also showed smaller total intracranial volume; smaller volumes and surface areas in the frontal lobe, inferior/middle parietal and temporal gyrus; smaller cerebellum, thalamus and basal ganglia volumes. Interestingly, all these structures correlated with attention subtests. CONCLUSION: These results highlight the persistent effects of being born small for gestational age on attention and associated brain structures.


Subject(s)
Attention Deficit Disorder with Hyperactivity/etiology , Attention Deficit Disorder with Hyperactivity/pathology , Cerebral Cortex/abnormalities , Infant, Small for Gestational Age , Adult , Birth Weight , Case-Control Studies , Cerebral Cortex/diagnostic imaging , Female , Follow-Up Studies , Humans , Infant, Newborn , Intelligence Tests , Magnetic Resonance Imaging , Male , Neuropsychological Tests , Prospective Studies
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