Search results for "brain"

Aquaporins and Brain Tumors

2016

Brain primary tumors are among the most diverse and complex human cancers, and they are normally classified on the basis of the cell-type and/or the grade of malignancy (the most malignant being glioblastoma multiforme (GBM), grade IV). Glioma cells are able to migrate throughout the brain and to stimulate angiogenesis, by inducing brain capillary endothelial cell proliferation. This in turn causes loss of tight junctions and fragility of the blood–brain barrier, which becomes leaky. As a consequence, the most serious clinical complication of glioblastoma is the vasogenic brain edema. Both glioma cell migration and edema have been correlated with modification of the expression/localization …

The Impacts of Tumor and Tumor Associated Epilepsy on Subcortical Brain Structures and Long Distance Connectivity in Patients With Low Grade Glioma

2018

Low grade gliomas in cerebral cortex often cause symptoms related to higher cerebral functions such as attention, memory and executive function before treatment is initiated. Interestingly, focal tumors residing in one cortical region can lead to a diverse range of symptoms, indicating that the impact of a tumor is extended to multiple brain regions. We hypothesize that the presence of focal glioma in the cerebral cortex leads to alterations of distant subcortical areas and essential white matter tracts. In this study, we analyzed diffusion tensor imaging scans in glioma patients to study the effect of glioma on subcortical gray matter nuclei and long-distance connectivity. We found that th…

A Novel Cervical Spinal Cord Window Preparation Allows for Two-Photon Imaging of T-Cell Interactions with the Cervical Spinal Cord Microvasculature d…

2017

T-cell migration across the blood-brain barrier (BBB) is a crucial step in the pathogenesis of experimental autoimmune encephalomyelitis (EAE), an animal model of multiple scle rosis (MS). Two-photon intravital microscopy (2P-IVM) has been established as a powerful tool to study cell-cell interactions in inflammatory EAE lesions in living animals. In EAE, central nervous system inflammation is strongly pronounced in the spinal cord, an organ in which 2P-IVM imaging is technically very challenging and has been limited to the lumbar spinal cord. Here, we describe a novel spinal cord window preparation allowing to use 2P-IVM to image immune cell interactions with the cervical spinal cord micro…

Brain MRI patterns in MPS IIIB (Sanfilippo syndrome type B): A longitudinal study

2016

Lack of NG2 exacerbates neurological outcome and modulates glial responses after traumatic brain injury

2015

Traumatic brain injury (TBI) is a major cause of death and disability. The underlying pathophysiology is characterized by secondary processes including neuronal death and gliosis. To elucidate the role of the NG2 proteoglycan we investigated the response of NG2-knockout mice (NG2-KO) to TBI. Seven days after TBI behavioral analysis, brain damage volumetry and assessment of blood brain barrier integrity demonstrated an exacerbated response of NG2-KO compared to wild-type (WT) mice. Reactive astrocytes and expression of the reactive astrocyte and neurotoxicity marker Lcn2 (Lipocalin-2) were increased in the perilesional brain tissue of NG2-KO mice. In addition, microglia/macrophages with acti…

Imaging in mice and men: Pathophysiological insights into multiple sclerosis from conventional and advanced MRI techniques

2019

Abstract Magnetic resonance imaging (MRI) is the most important tool for diagnosing multiple sclerosis (MS). However, MRI is still unable to precisely quantify the specific pathophysiological processes that underlie imaging findings in MS. Because autopsy and biopsy samples of MS patients are rare and biased towards a chronic burnt-out end or fulminant acute early stage, the only available methods to identify human disease pathology are to apply MRI techniques in combination with subsequent histopathological examination to small animal models of MS and to transfer these insights to MS patients. This review summarizes the existing combined imaging and histopathological studies performed in M…

Introducing the concept of “CSF-shift edema” in traumatic brain injury

2018

Brain edema after severe traumatic brain injury (TBI) plays an important role in the outcome and survival of injured patients. It is also one of the main targets in the therapeutic approach in the current clinical practice. To date, the pathophysiology of traumatic brain swelling is complex and, being that it is thought to be mainly cytotoxic and vasogenic in origin, not yet entirely understood. However, based on new understandings of the hydrodynamic aspects of cerebrospinal fluid (CSF), an additional mechanism of brain swelling can be considered. An increase in pressure into the subarachnoid space, secondary to traumatic subarachnoid hemorrhage, would result in a rapid shift of CSF from t…

Progranulin protects against exaggerated axonal injury and astrogliosis following traumatic brain injury

2016

In response to traumatic brain injury (TBI) microglia/macrophages and astrocytes release inflammatory mediators with dual effects on secondary brain damage progression. The neurotrophic and anti-inflammatory glycoprotein progranulin (PGRN) attenuates neuronal damage and microglia/macrophage activation in brain injury but mechanisms are still elusive. Here, we studied histopathology, neurology and gene expression of inflammatory markers in PGRN-deficient mice (Grn-/- ) 24 h and 5 days after experimental TBI. Grn-/- mice displayed increased perilesional axonal injury even though the overall brain tissue loss and neurological consequences were similar to wild-type mice. Brain inflammation was …

Depletion of regulatory T cells increases T cell brain infiltration, reactive astrogliosis, and interferon-γ gene expression in acute experimental tr…

2019

Abstract Background Traumatic brain injury (TBI) is a major cause of death and disability. T cells were shown to infiltrate the brain during the first days after injury and to exacerbate tissue damage. The objective of this study was to investigate the hitherto unresolved role of immunosuppressive, regulatory T cells (Tregs) in experimental TBI. Methods “Depletion of regulatory T cell” (DEREG) and wild type (WT) C57Bl/6 mice, treated with diphtheria toxin (DTx) to deplete Tregs or to serve as control, were subjected to the controlled cortical impact (CCI) model of TBI. Neurological and motor deficits were examined until 5 days post-injury (dpi). At the 5 dpi endpoint, (immuno-) histological…

2017

Danger associated molecular patterns (DAMPs) are released by damaged cells and trigger neuroinflammation through activation of non-specific pattern recognition receptors (PRRs), e.g. Toll-like receptors (TLRs). Since the role of TLR 2 and 4 after traumatic brain injury (TBI) is still unclear, we examined the outcome and the expression of proinflammatory mediators after experimental TBI in Tlr2/4 / and wild-type (WT) mice. Tlr2/4 / and wild-type mice were subjected to controlled cortical injury and contusion volume and brain edema formation were assessed 24 h thereafter. Expression of inflammatory markers in brain tissue was measured by quantitative PCR 15 min, 3, 6, 12, and 24 h after contr…