When Ehrlich discovered the first evidence of the blood-brain barrier in 1885, he probably did not perceive the Great Wall that remained hidden from consciousness inside the central nervous system. Ehrlich had observed that acidic vital dyes did not stain the brain if they were injected into the blood stream. A century ago (1913), Goldman showed that the injection of trypan blue in the cerebrospinal fluid stained only the brain, but not the other organs. For almost a century it was thought that the blood-brain barrier (BBB) consisted in a physical barrier, resulting from the restricted permeability of the cerebral endothelial cell layer, as they are joined by tight junctions. However, as scientists are always looking for news in what is already discovered, in the end of the 20th century we had evidences that cerebral endothelial and glial cells express several drug metabolizing enzymes consisting in a second protection system: a metabolic barrier. Furthermore, the drugs and their metabolites must overcome the activity of several multidrug resistance proteins that function as ATP-dependent efflux pumps, consisting in the third line of defence: the active barrier. Therefore, the way the BBB actually works should be better explained. Several endogenous compounds, as well as xenobiotics, may be activated by enzymes of the metabolic barrier, generating reactive oxygen species that could damage neurons. Therefore, endothelial and glial cells possess endogenous protecting compounds and enzymes against oxidants, consisting in an antioxidant barrier. When all these systems fail, glial cells, mainly microglia, secrete cytokines in an attempt to crosstalk with defence cells asking for help, which consists in an immune barrier. In cerebral regions that are devoid of the physical barrier, such as circumventricular organs, the metabolic, active, antioxidant and immune barriers are reinforced. It is important to understand how cells involved in the BBB interact with one another and the dynamic mechanisms of their functions. This Research Topic published in this e-Book considers recent highlights in BBB structure, cell and molecular biology, biotransformation, physiology, pathology, pharmacology, immunology and how these basic knowledges can be applied in drug discovery and clinical researches, rewriting what is already written, and paving the way that goes to the Great Wall in the Frontiers of the Brain in this new century that is just beginning.

The past decade has witnessed a revolution in the attempts of scientists to under stand the molecular basis of dementia. Although dementia, as defined by global cogni tive decline involving gradual loss of memory, reasoning, judgment, and orientation, presents most commonly in the form of Alzheimer's disease (AD), an assortment of other less common disorders, such as prion and Pick's disease, can also lead to symp toms that are similar to those observed in patients with AD. The primary goal of Molecular Mechanisms of Dementia is to address the various mechanisms and multi faceted approaches currently being employed to more clearly delineate the etiological and pathogenic events responsible for the onset of dementia. Perhaps the greatest boon to obtaining a clearer understanding of the causes of AD has come from genetic and molecular biological studies carried out over the past decade. At the genetic level, it has become increasingly clear that AD is a heteroge neous disorder that can be broadly classified into two categories. "Late onset" (>60 yr) cases, which account for the vast majority of AD, genetically involve "susceptibility" genes representing risk factors for the disease (e. g. , inheritance of the 84 allele of the Apolipoprotein E gene). In many cases, the susceptibility gene can act as a "modifier" that modulates the pathogenic cascade occurring subsequent to a separate etiological event "initiating" or "causing" the disorder.

Glioblastoma Resistance to Chemotherapy: Molecular Mechanisms and Innovative Reversal Strategies brings current knowledge from an international team of experts on the science and clinical management of glioblastoma chemoresistance. The book discusses topics such as molecular mechanisms of chemoresistance, experimental models to study chemoresistance, chemoresistance to drugs other than Temozolomide, and specific strategies to reverse chemoresistance. Additionally, it encompasses information on how to mitigate chemoresistance by targeted enhancement of p53 function. This book is a valuable resource for cancer researchers, oncologists, neuro-oncologists and other members of the biomedical field. Glioblastoma (GBM) is the most invasive and malignant primary brain tumor in humans with poor survival after diagnosis, therefore it is imperative that molecular and cellular mechanisms behind therapy resistant GBM cells, as well as the therapeutic strategies available to counter the resistance are comprehensively understood. - Provides comprehensive, core knowledge related to the entire discipline of glioblastoma chemoresistance, from its many etiological mechanisms, to specific strategies to reverse resistance - Presents current information from an international team of experts on the basic science, pre-clinical research, and clinical management of glioblastoma chemoresistance - Discusses molecular and cellular mechanisms behind therapy resistant glioblastoma cells, as well as the therapeutic strategies available to counter this resistance

The six volumes of Peterson's Annual Guides to Graduate Study, the only annually updated reference work of its kind, provide wide-ranging information on the graduate and professional programs offered by accredited colleges and universities in the United States and U.S. territories and those in Canada, Mexico, Europe, and Africa that are accredited by U.S. accrediting bodies. Books 2 through 6 are divided into sections that contain one or more directories devoted to individual programs in a particular field. Book 3 contains more than 4,000 programs of study in 53 disciplines of the biological sciences.