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Blood Brain Barrier (blood + brain_barrier)
Selected AbstractsDefining antigen-dependent stages of T cell migration from the blood to the central nervous system parenchymaEUROPEAN JOURNAL OF IMMUNOLOGY, Issue 4 2005Angela Abstract In experimental autoimmune encephalomyelitis (EAE), intravenous transfer of activated CD4+ myelin-specific T cells is sufficient to induce disease. Transferred T cells access the CNS parenchyma by trafficking across the blood brain barrier (BBB) vascular endothelium into the perivascular space, and then across the glial limitans that is made up of astrocytes and microglia. Flow cytometry analysis of cells isolated from CNS tissue does not distinguish between T cell populations at the various stages of migration. In this study, we have used GK1.5 (anti-CD4) treatment along with immunohistochemistry to distinguish between populations of T cells that are associated with the vasculature, T cells that have migrated into the perivascular space, and T cells in the parenchyma. We have also re-evaluated antigen specificity requirements of T cells as they are recruited to the CNS parenchyma. Activated myelin-specific T cells are restricted to the CNS vasculature for at least 24,h post transfer. MHC class II expression on the recipient is required for cells to traffic across the CNS vascular endothelium. Further, Con A-stimulated or non-CNS-specific (ovalbumin-specific) T cells fail to migrate into the perivascular space, and only enter the CNS parenchyma when co-transferred with myelin-specific T cells. Our results indicate that Th1 populations cannot accumulate in the perivascular (subarachnoid, Virchow-Robbins) space without a CNS antigen-specific signal. [source] Asymmetric bolaamphiphiles from vernonia oil designed for drug deliveryEUROPEAN JOURNAL OF LIPID SCIENCE AND TECHNOLOGY, Issue 1 2010Sarina Grinberg Abstract Throughout the ages, fats, oils and their chemical derivatives have been used in a variety of medical applications, but currently they are becoming important as components in drug delivery systems. Liposomes (vesicles from phospholipids) are among the lipid-based delivery systems that have been most extensively studied. However, targeting of liposomes to specific tissues is still problematic, and attempts to overcome these limitations include developments in nano-sized monolayer vesicles made of bolaamphiphiles (compounds containing two hydrophilic headgroups at each end of an alkyl chain). This paper describes bolaamphiphile synthesis and characterization of the nano-sized vesicles formed from the bolaamphiphiles with potential application for targeted drug delivery to the brain. The starting material for the synthesis is vernonia oil (or its fatty acids or methyl esters), which is a naturally epoxidized triacylglycerol obtained from the seeds of Vernonia galamensis. The targeting mechanism is based on the hydrolysis of the amphiphile's headgroup by an enzyme abundant in the target tissue, with subsequent release of the encapsulated drug at the target site. Preliminary experiments in mice demonstrated that the marker FITC-dextran, which normally does not penetrate the blood brain barrier, is delivered into the brain when encapsulated in these vesicles. [source] The angiotensin converting enzyme (ACE) inhibitor, perindopril, modifies the clinical features of Parkinson's diseaseINTERNAL MEDICINE JOURNAL, Issue 1 2000K. A. Reardon Abstract Background: Animal studies have demonstrated an interaction within the striatum between the angiotensin and dopaminergic systems. In rats, the angiotensin converting enzyme (ACE) inhibitor, perindopril, crosses the blood brain barrier and increases striatal dopamine synthesis and release. In humans, angiotensin type 1 receptors have been found on dopaminergic neurons in the substantia nigra and striatum. In Parkinson's disease, there is a marked reduction of these receptors associated with the nigrostriatal dopaminergic neuron loss. Aims: We performed a double blind placebo controlled crossover pilot study in seven patients to investigate the effect of the ACE inhibitor, perindopril on the clinical features of moderately severe Parkinson's disease. Results: After a four week treatment period with perindopril, patients had a faster onset in their motor response to L-dopa and a reduction in ,on phase' peak dyskinesia, p=0.021 and p=0.014 respectively. Patients also reported more ,on' periods during their waking day in their movement diary, p=0.007. Perindopril was well tolerated without any significant postural hypotension or renal dysfunction. Conclusions: These results suggest that ACE inhibitors such as perindopril may have a place in the management of motor fluctuations and dyskinesia in Parkinson's disease and justify further study. [source] Chronic granulomatous disease presenting with disseminated intracranial aspergillosisPEDIATRIC BLOOD & CANCER, Issue 1 2006Abdul Alsultan MD Abstract We describe an 8-year-old boy who presented with multiple unresectable aspergillus brain abscesses as the initial presentation of X-linked chronic granulomatous disease (CGD). He failed initial therapy with amphotericin B, but was subsequently salvaged with voriconazole. CGD should be considered in the differential diagnosis for all children presenting with invasive fungal infections, particularly, those involving the central nervous system (CNS). Whereas, optimal pharmacologic therapy is still unknown for CNS aspergillosis, voriconazole may have an advantage due to its ability to cross the blood brain barrier and excellent oral absorption and bioavailability. © 2005 Wiley-Liss, Inc. [source] Studies on microwaves in medicine and biology: From snails to humansBIOELECTROMAGNETICS, Issue 3 2004James C. Lin Abstract This d'Arsonval Medal acceptance presentation highlights several research themes selected from Dr. Lin's published works, focusing on the microwave portion of the nonionizing electromagnetic spectrum. The topics discussed include investigation of microwave effects on the spontaneous action potentials and membrane resistance of isolated snail neurons, effects on the permeability of blood brain barriers in rats, the phenomenon and interaction mechanism for the microwave auditory effect (the hearing of microwave pulses by animals and humans), the development of miniature catheter antennas for microwave interstitial hyperthermia treatment of cancer, the application of transcatheter microwave ablation for treatment of cardiac arrhythmias, and the use of noninvasive wireless technology for sensing of human vital signs and blood pressure pulse waves. The paper concludes with some observations on research and other endeavors in the interdisciplinary field of bioelectromagnetics. Bioelectromagnetics 25:146,159, 2004. © 2004 Wiley-Liss, Inc. [source] | |||||||||||||