Mass spectrometry imaging (MSI) of metals by laser ablation ICP-MS and metallomics of biomedical samples

Trace metals are essential in life science and play a major role in biological processes. Knowledge of spatial distribution of metals and metal-containing proteins is fundamental for understanding the pathophysiology of metalloproteins, the impact of metal metabolism and metal-containing deposits in healthy brains and brains of patients suffering from neurological diseases. In recent years, there has been a growing interest in studying metal imaging in biological and especially in clinical tissues. In most neurodegenerative diseases, abnormal metal deposition has been observed within the brain (e.g., in Alzheimer's, Parkinson's or Wilson diseases). Laser-induced mass spectrometry is a novel emerging analytical tool to generate two- and three-dimensional maps of the distribution of elements, isotopes and molecules in different systems. Laser ablation inductively coupled plasma mass spectrometry (LA-ICP-MS) is one of the most important inorganic mass spectrometric technique for solid materials and has been successfully applied to produce quantitative images of detailed regionally specific element distributions in thin soft tissue sections of biological and clinical samples. The spatial resolved “BrainMet” techniques (BrainMet – Bioimaging of Metals in Brain and Metallomics) developed at Research Centre Juelich have been created and established for metal distribution studies in thin biomedical cryosection and it can be employed for fundamental biomedical investigation of biochemical pathways up to single cell level and in future for disease diagnostics and neuroprotective therapies of neurological disorders

Metal imaging in non-denaturating 2D electrophoresis gels by laser ablation inductively coupled plasma mass spectrometry (LA-ICP-MS) for the detection of metalloproteins

Laser ablation inductively coupled plasma mass spectrometry (LA-ICP-MS) was developed as a powerful analytical technique for metal imaging of 2D gels for the detection of metalloproteins in rat kidney after electrophoretic separation. Protein complexes, extracted with water, were separated in their native state in the first and second dimension by blue native gel electrophoresis (BN-PAGE). Essential and toxic metals, such as zinc, copper, iron, manganese and lead, were monitored by LA-ICP-MS after gel ablation by a focused laser beam in a way that the total surface of a selected fragment of the gel was totally ablated. The metal distribution of this part of the gel was then constructed by plotting the metal (isotope) signal intensity as a function of the x,y (isoelectric point, molecular mass) coordinates of the gel. The proteins at locations rich in metals were cut out, digested with trypsin and analyzed by matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI-TOF-MS)

Detection of Zn-containing proteins in slug (Genus Arion) tissue using laser ablation ICP-MS after separation by gel electrophoresis

Assessing the inventory of biological systems in respect to metal species is a growing area of life science research called metallomics. Slugs are of special interest as monitor organisms for environmental contaminations. Laser ablation inductively coupled plasma mass spectrometry (LA-ICP-MS) was applied to map the distribution of total Zn in a section of a slug sample and to detect Zn-containing proteins after one-dimensional separation by gel electrophoresis (Blue Native PAGE). Interestingly, by far the largest fraction of protein bound Zn was explained by three sharp and prominent bands at 75,100 and 150 kDa. Analysis of tryptic digests of selected bands using MALDI-TOF-MS and public databases failed to identify proteins within the Zn bands what may be due to coverage gaps concerning the species anon ater. Three non-Zn containing bands could be assigned to proteins known from other mollusc species. (C) 2011 Elsevier B.V. All rights reserved

Mass spectrometric imaging (MSI) of metals using advanced BrainMet techniques for biomedical research

Mass spectrometric imaging (MSI) is a young innovative analytical technique and combines different fields of advanced mass spectrometry and biomedical research with the aim to provide maps of elements and molecules, complexes or fragments. Especially essential metals such as zinc, copper, iron and manganese play a functional role in signaling, metabolism and homeostasis of the cell. Due to the high degree of spatial organization of metals in biological systems their distribution analysis is of key interest in life sciences. We have developed analytical techniques termed BrainMet using laser ablation inductively coupled plasma mass spectrometry (LA-ICP-MS) imaging to measure the distribution of trace metals in biological tissues for biomedical research and feasibility studies-including bioaccumulation and bioavailability studies, ecological risk assessment and toxicity studies in humans and other organisms. The analytical BrainMet techniques provide quantitative images of metal distributions in brain tissue slices which can be combined with other imaging modalities such as photomicrography of native or processed tissue (histochemistry, immunostaining) and autoradiography or with in vivo techniques such as positron emission tomography or magnetic resonance tomography.Prospective and instrumental developments will be discussed concerning the development of the metalloprotein microscopy using a laser microdissection (LMD) apparatus for specific sample introduction into an inductively coupled plasma mass spectrometer (LMD-ICP-MS) or an application of the near field effect in LA-ICP-MS (NF-LA-ICP-MS). These nano-scale mass spectrometric techniques provide improved spatial resolution down to the single cell level. (C) 2011 Elsevier B.V. All rights reserved

Strategies for Efficient, Meaningful, and Inclusive Online Learning Environments: It\u27s About Time

Students and faculty rely on clear and unambiguous time targets to exchange information and pace their intersecting lives. Most students juggle work, family, and commuting demands, and increasing numbers also struggle with language needs and disabilities, requiring additional and flexible time to grasp the scope of assignments, read and gather information, process concepts into written products, and finally make sense of the experience. It all takes time. In this chapter, practical strategies for structuring time expectations are introduced in the context of a commitment to empower self-regulation and lifelong learning with particular attention to accessibility. The time dimension of each component of the syllabus, assignments, and gradebook are described with examples from a successful online course, with reference to theory and research on student engagement and satisfaction