View clinical trials related to Blood Brain Barrier Defect.
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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.