Neurological Biomarkers Research Articles

Antibody Markers for Studying Neurodegeneration in the Nothobranchius Central Nervous System

Fish of the genus Nothobranchius have a naturally short lifespan in which they develop several neurological biomarkers of aging. This short lifespan (several months compared to several years in mice and zebrafish) make these fish a promising alternative in aging research. Resveratrol dosing retarded the development of the neurological biomarkers of aging identified in N. furzeri. Resveratrol's method of action was not determined due to the lack of celltype specific markers of degenerative processes. Further research of the Nothobranchius CNS and its degeneration is hampered by the lack of cell-type specific antibodies and other cellular markers of degenerative processes. In this article the authors present a molecular toolbox of five antibodies and a lectin which can be used to study the Nothobranchius central nervous system and its degeneration. These antibodies were tested against western blots of rat, zebrafish and Nothobranchius guentheri brain homogenates as well as frozen sections. Antibodies shown to reliably bind with N. guentheri proteins were: SMI31 which labeled axons and dendrites; mouse anti-human GFAP and rabbit anti-cow GFAP which labeled astroglia; mouse anti-rat tenascin-R which labeled oligodendrocytes; and E587 anti-goldfish L1 which labeled neuronal and astrocytic cell bodies and processes. The BS-I isolectin B4 labeled microglia in the optic nerve and retina. This toolbox will enable researchers to study the aging brain of Nothobranchius as well as its normal development at a cellular level.

In-depth Exploration of Cerebrospinal Fluid by Combining Peptide Ligand Library Treatment and Label-free Protein Quantification

Cerebrospinal fluid (CSF) is the biological fluid in closest contact with the brain and thus contains proteins of neural cell origin. Hence, CSF is a biochemical window into the brain and is particularly attractive for the search for biomarkers of neurological diseases. However, as in the case of other biological fluids, one of the main analytical challenges in proteomic characterization of the CSF is the very wide concentration range of proteins, largely exceeding the dynamic range of current analytical approaches. Here, we used the combinatorial peptide ligand library technology (ProteoMiner) to reduce the dynamic range of protein concentration in CSF and unmask previously undetected proteins by nano-LC-MS/MS analysis on an LTQ-Orbitrap mass spectrometer. This method was first applied on a large pool of CSF from different sources with the aim to better characterize the protein content of this fluid, especially for the low abundance components. We were able to identify 1212 proteins in CSF, and among these, 745 were only detected after peptide library treatment. However, additional difficulties for clinical studies of CSF are the low protein concentration of this fluid and the low volumes typically obtained after lumbar puncture, precluding the conventional use of ProteoMiner with large volume columns for treatment of patient samples. The method has thus been optimized to be compatible with low volume samples. We could show that the treatment is still efficient with this miniaturized protocol and that the dynamic range of protein concentration is actually reduced even with small amounts of beads, leading to an increase of more than 100% of the number of identified proteins in one LC-MS/MS run. Moreover, using a dedicated bioinformatics analytical work flow, we found that the method is reproducible and applicable for label-free quantification of series of samples processed in parallel.

Metallomic Distribution in Various Regions of the Brain as Influenced by Dietary Intakes and Their Implications

Lifelong exposure to environmental factors can influence the risk of developing diseases according to recent research findings. Environmental stresses ultimately leading to neuronal cell death have been hypothesized as the causes of the increased occurrence in developing Alzheimer's and Parkinson's disease. Our daily diet is considered to be one of the most important environmental factors that can seriously affect the development and proper functions of the brain. Depending on the concentrations, metals and electrolytes can post some health concerns, especially for a prolonged consumption period. For example, it was reported that excess amounts of iron, zinc and copper in the human brain may cause oxidative damage and protein aggregation; the neurotoxicity induced by these metals may lead to cerebral and/or cerebellar degeneration. Other reports showed that there were differences in concentrations of five different elements (aluminum, zinc, copper, manganese, and iron) between normal human brain and brains of patients with Alzheimer's disease. In this study, we investigated 30 elements, including electrolytes, and how dietary intake on a life-time basis would affect their concentrations and distributions in various regions of the rat brain (hypothalamus, cerebellum, pons and medulla, striatum, mid-brain, cerebral cortex, and hippocampus) and discussed their health implications. Information matrices of these 30 different elements (mostly metals) and their distributions in various regions of the rat brain were analyzed as a function of normal dietary intake at different ages during development. Our results showed that metallomic distribution in various regions of the rat brain is age-related. The results may help researchers to identify possible links between daily dietary intake of metals and electrolytes and diseases associated with aging (e.g., Alzheimer's and Parkinson's disease) and suggest such metallomic distributions may be used as neurological biomarkers of exposure to heavy metals.

Frontiers of Neurology and Neuroscience

This is the recent volume in the series Frontiers of Neurology and Neuroscience. Like previous volumes, this is a brief (approximately 200 pages) multi-author review aimed mainly, as indicated by the flyer, at clinical neurologists. As there are over 30 chapters, each chapter is relatively short. The present volume addresses the question of clinical trials. Although its focus is disorders of the central nervous system, the discussion of trial methodology is generally applicable to all clinical areas. The book systemically covers all stages of drug development up to the point of obtaining a marketing licence, and does not deal with postmarketing surveillance and pharmacovigilance. After two brief introductory chapters, which have the role of ‘setting the scene’, there are four chapters devoted to preclinical trials. These interesting chapters consider animal studies from the point of view of the design of subsequent clinical trials and the translation of information obtained from animal models into the clinical situation. The remainder of the book is devoted to the assessment of the efficacy and safety of drugs in human populations. Phase I and II trials are considered together, describing the principles of design and data analysis. There is a helpful chapter on biomarkers in neurology, discussing the features and roles of biomarkers in general, followed by examples in neurodegenerative diseases and stroke. The next two sections take up the bulk of the book: discussion of issues relating to Phase III trials. The first two chapters in this section deal with regulatory requirements in the USA and Europe. This is followed by a general discussion of design, analysis, clinical end-points and data management. A large section of the book is specifically devoted to multicentre trials, discussing principles of design and analysis, recruitment, obtaining informed consent, the role of local ethics committees (‘institutional review boards’ in the USA), budgeting, medical monitoring, and general management. An interesting section is devoted to special populations, such as patients suffering from progressive neurological diseases, children, neurological emergencies when the patients are unable to give consent, and trials with a genetic focus. Finally, there are chapters discussing the potential role of brain imaging in clinical trials and a chapter on training issues. Overall, this is a broadly-based book whose major virtue is placing the placebo-controlled randomized trial, ‘the gold standard’ for the assessment of the efficacy and safety of new therapeutic agents, into the general context of the process of drug development. However, although the large field covered has the advantage of giving a general perspective, inevitably this is achieved at the expense of factual detail and in-depth analysis. Furthermore, the reference to neurosciences is rather arbitrary: although some chapters are clearly related to some neurological disorders (mainly neurodegenerative diseases and stroke), many do not have such a focus and relate to trial principles and practice in general. Thus, issues of clinical neurology serve as illustrations rather than providing the main focus of the book. Indeed, many neurological disorders (e.g. multiple sclerosis, epilepsy) with huge on-going clinical trial activity, hardly receive a mention. In conclusion, this is a useful overview of clinical trial methodology and some issues associated with it in general, but it provides only limited information about clinical trial activity related to disorders of the central nervous system. A minor quibble: this is an almost entirely American book (out of 45 authors there is only one from Europe), and even the chapter on European regulatory requirements is written by an American. I think that the general appeal of the book, at least on this side of the Atlantic, would have been enhanced by a more international authorship.

Recent advances in research and treatment of neurological disorders

This year the American Academy of Neurology celebrated its 60th Annual Meeting that brought together over 10,000 neurologists and neuroscientists from all over the world in Chicago, Illinois. This report highlights relevant presentations covering the pathophysiology of neurological disorders, investigational therapies and biomarkers that will allow better diagnosis, monitoring and treatment of patients with neurological disease.

Serum S-100 Protein in Stroke and Cardiac Surgery

To the Editor: We have followed with interest the discussion regarding S-100 proteins in stroke and cardiac surgery between Drs Wong and Bonser and Drs Missler and Wiesmann. We noticed that Drs Missler and Wiesmann questioned the specificity of our Sangtec 100 LIA assay. It is correct that the validation of the Sangtec 100 LIA assay has yet to be published. A complete validation regarding specificity has, however, been performed at Sangtec Medical during development of the assay. The monoclonal antibodies used in the Sangtec 100 LIA assay are the same as in the Sangtec 100 IRMA assay, and they have been shown to be S-100B specific using the biosensor-based BIAcore system (L. Nyberg, A. Ullen, K. Haglid, E. Sandstrom, T. Stigbrand, and J. Brundell, unpublished data, 1998). In collaboration with DAKO, we have shown that recombinant human A1, A2, A4, and A6 are not detected in the Sangtec 100 LIA assay (see Figure⇓). Furthermore, calmodulin and troponin C are not measured in …

PIAL CIRCULATION AND SPREADING DEPRESSION OF ACTIVITY IN THE CEREBRAL CORTEX

PIAL CIRCULATION AND SPREADING DEPRESSION OF ACTIVITY IN THE CEREBRAL CORTEX