View clinical trials related to Blood Brain Barrier Defect.
Filter by:Major depressive disorder (MDD) is a chronic mental illness, with 60% lifetime risk of recurrence after the first MDD episode. Despite available treatment options for MDD, only about half to two-thirds of patients respond to first-line antidepressant treatment, and only 30% to 45% of patients achieve remission. Scholars assume that this low remission rate and high rate of treatment resistance are due to the polyetiological nature of the disease, the heterogeneity of the clinical picture of depression, and the lack of biomarkers to stratify MDD subtypes. The aetiology of MDD, although researched extensively, remains unclear. None of the known mechanisms alone explains the pathogenesis of depression, meaning that the interplay of several factors contributes to the development of MDD. Accumulated scientific evidence has supported the importance of the immune system in the etiopathogenesis of MDD. Until now, the cause of the low-grade inflammation observed in this subgroup of MDD patients has been unclear. In the proposed study, the investigators will test a new hypothesis of the immune theory of the development of MDD: the endotoxin hypothesis of neurodegeneration. This hypothesis states that endotoxin, causes or contributes to neurodegeneration. Blood plasma levels of LPS are normally low but are elevated during infections, gut inflammation, gum disease, and neurodegenerative diseases. Dysbiosis may promote increased intestinal permeability ("leaky gut"), which leads to bacterial translocation across the intestinal barrier and into the circulation, thus forming of LPS and LPS-binding protein complex, which triggers the secretion of cytokines. Data suggest that LPS-induced peripheral inflammation can activate neuroinflammation. However, it is not known whether a low-level persistent presence of LPS in the circulatory system can cause low-grade chronic neuroinflammation leading to neurodegeneration and/or symptoms of MDD. Based on existing preclinical and clinical research data, the investigators hypothesise that an increase in blood plasma endotoxin and peripheral cytokines induce BBB dysfunction, neuroinflammation and neurodegenerative processes in specific etiologically relevant structures of the brain and cause clinical manifestation of depressive symptoms and cognitive damage. In this study the investigators are also going to investigate the effects of single nucleotide polymorphisms of four genes in relation to blood plasma endotoxin and peripheral cytokines concentrations and clinical manifestation of MDD.
Diffusion prepared pseudo-continuous ASL (DP-pCASL) is a newly proposed MRI method to noninvasively measure the function of blood-brain barrier (BBB). The investigators aim to investigate whether the water exchange rate across the BBB, estimated with DP-pCASL, is changed in patients with CADASIL, and to analyze the association between BBB water exchange rate and MRI/clinical features in these patients.
Previous work has demonstrated patients presenting with ruptured aneurysms that develop radiographic and clinical vasospasm have a higher permeability of the blood brain membrane. Matrix metalloproteinase 9 (MMP9) has been studied and recently implicated in both the pathogenesis of the blood brain barrier breakdown and vasogenic edema of ischemia strokes, and is suggested to be an accurate biomarker to predict the onset of cerebral vasospasm after subarachnoid hemorrhage. The therapeutic benefit of minocycline, an MMP9 inhibitor, has been investigated in ischemic stroke population, however its role in the treatment of cerebral vasospasm from ruptured aneurysms remains unknown. Our project has two main goals: to further confirm MMP9 has a reliable biomarker for the onset of cerebral vasospasm, and secondarily to investigate any possible therapeutic benefit that minocycline has in the vasospasm population. Vasospasm continues to be one of the major contributors of morbidity and mortality in the ruptured aneurysm population, and close monitoring of the neurologic exam during the 'vasospasm window' usually requires two weeks in the intensive care unit in most academic settings. As such, if we are better able to predict which patients are at risk of developing vasospasm based on MMP9 levels, we will be better able to anticipate the need for intervention and therefore mitigate the risk of vasospasm induced ischemic strokes, ultimately resulting in better outcomes in the ruptured aneurysm population. Further, if we are able to identify minocycline as a therapeutic agent to deter, or lessen the severity of vasospasm, we can possibly improve neurologic outcomes, decrease hospital stays, ultimately providing an improved and more cost-effective treatment strategy to our patients.
The aim of our study is the analysis of sleep phases and quality as well as the detection of respiratory pauses in subjects with cognitive disorder. To assess whether sleep quality is associated with the blood-brain barrier and Alzheimer's disease, which may be indicative of an early, non-invasively measurable change in brain activity in the early stages of Alzheimer's disease.
the trial aims to evaluate the Efficacy and Safety of gadopiclenol for Central Nervous System (CNS) Magnetic Resonance Imaging (MRI)
The incidence of postoperative cognitive injury is high in elderly patients, especially after major surgery. The relevant pathophysiological mechanisms are still unclear, and the possible mechanisms that have been proposed so far include inflammation, neurotransmitter imbalance and metabolic disorders. In recent years, clinical studies of acute brain dysfunction after vascular endothelial injury have attracted attention. Degradation of the endothelial glycocalyx layer and subsequent shedding of its constituents is seen as an early marker of endothelial injury, and may increase vascular permeability.Many preclinical and clinical studies have demonstrated an association between inflammatory cytokines such as TNF-α, IL-1β, IL-6, and IL-10 and glycocalyx degradation biomarkers. The scholars found evidence of plasma endothelial injury after abdominal open surgery in the elderly. Dexmedetomidine could attenuate stress response such as TNF-α, IL-1β and IL-6. Based on the above evidence, we hypothesize that elderly patients experience inflammatory response secondary to surgical traumatic stress after major surgery, greatly increasing the degree of endothelial injury (heparan sulphate and syndecan-1), reducing brain perfusion while increasing Blood-brain barrier permeability (S100B level), promoting the release of cytokines Interleukin-2(IL-2), Interleukin-6(IL-6), tumor necrosis factor-alpha(TNF-α) ,and vascular endothelial growth factor (VEGF) while reducing brain-derived neurotrophic factor(BDNF) synthesis, then leading to postoperative acute spasm. We would test the hypothesis that can reverse these effects and improve cognitive deficits.
Traumatic brain injury (TBI) is a leading cause of death and disability around the world. The social and economic burden of TBI is tremendous and the cost of TBI is estimated at $1 billion per year in Canada- $650 million in care and $580 million in lost productivity. Novel interventions aimed at TBI-linked molecular targets have been successful in limiting injury and improving neurologic recovery in animal models, thus providing compelling evidence that effective intervention is possible after injury. This study proposes to investigate traumatic microvascular injury (TMI) and specifically blood-brain barrier dysfunction (BBBD) as a candidate biomarker and therapeutic target in TBI.
The purpose of this study was to determine a safe and effective dose of a new gadolinium-based contrast agent (GBCA) P03277 based on the Contrast to Noise Ratio (CNR) when comparing with gadobenate dimeglumine (MultiHance®) at 0.1 mmol/kg body weight (BW). Contrast to Noise Ratio (CNR), a well-known quantitative parameter directly related to contrast medium/GBCA efficacy, was chosen as the primary endpoint in order to have a precise determination of P03277 clinical dose. This was a multi-center, international, prospective, double-blind, randomized, controlled, parallel dose groups, cross-over with comparator study in male and female subjects presenting with known or highly suspected focal areas of disruption of the Blood Brain Barrier including at least one expected enhancing lesion of minimum 5 mm, who were scheduled to undergo a routine contrast-enhanced Magnetic Resonance Imaging (MRI) of Central Nervous System.
The blood-brain barrier (BBB) is an intricate barrier composed of a variety of efflux pumps, a luminal negative charge, a basal lamina and three distinct cell types: brain endothelial cells, pericytes, and astrocyte foot processes. Specifically, the BBB integrity and degree of permeability is regulated by the capillary endothelial cells in response to astrocytic signals. The strength of intercellular junctions (ex. tight junctions, adherins) amongst endothelial cells also plays a major role in permeability. Therefore, modulation of all these paracellular properties may decrease BBB integrity and thus improve drug penetration to the tumor bed. Previous studies utilizing the vasoactive peptide, Regadenoson, demonstrated transient increase in BBB permeability, allowing a 70kD dextran molecule to enter the brain of rodents. Thus, the investigators propose to evaluate brain interstitium concentrations of temozolomide pre and post Regadenoson using brain microdialysis. If Regadenoson successfully demonstrates effectiveness in disrupting the BBB, it could be of major importance in improving the outcome of patients with a variety of brain tumors and other neurologic illnesses.