Bleeding is a common result of an acute injury but chronic bleeding is not a condition that gets much publicity on television, the press or in advertising campaigns. Chronic bleeding is not an insignificant problem for those who suffer from it and many people do not even realize that they have a bleeding condition. Examples of bleeding disorders include hemophilia which is fortunately uncommon and von Willebrands disease which afflicts as many as 3-6 million Americans. There are many types of bleeding disorders; diagnostic approaches include the evaluation of clotting factors, blood vessel fragility, and assessment of quantitative and qualitative platelet conditions.
Symptoms related to platelet dysfunction (a qualitative abnormality) include frequent nose bleeds, easy bruising, and specific to women, menorrhagia (heavy periods). The utilization of a variety of microscopic techniques is essential to diagnose platelet dysfunction. Electron microscopy is extremely useful to diagnose some conditions that affect platelet size and/or reduced numbers of platelets. A disorder that mimics von Willebrands disease and could affect 10 to 15 million Americans can be easily diagnosed using a simple electron microscopic technique. Examples of bleeding disorders and the use of microscopy to accurately diagnose the conditions will be discussed
Contact: Department of Pathology, 2288 Dowling Hall, 3000 Arlington Avenue, Toledo, Ohio 43614-5806. (419) 383-3752; william.gunning@utoledo.edu
The atomic-resolution capabilities of the electron microscope have had a major impact across many disciplines. Resolving powers close to or exceeding the one Angstrom (0.1nm) barrier have been achieved by high-voltage HREMs, and by dedicated scanning and conventional medium-voltage instruments. Other instrumentation developments include aberration correctors and electron monochromators. These latest developments have generated great interest and enthusiasm from within the microscopy community, and attracted much attention from the broader materials community.
Semiconductor heterostructures and nanostructures play a major role in the development of optoelectronic devices spanning wavelengths from the ultraviolet to the far-infrared. However, the fabrication of composite structures based on two (or more) dissimilar materials presents many interesting challenges. Lattice mismatch leads to strain and possible defect formation, while valence mismatch and differences in thermal expansion can seriously impact the final material quality. Microstructural characterization using electron microscopy methods plays a crucial role in understanding, controlling and optimizing materials' properties. This talk will describe recent atomic-resolution studies of several systems of much scientific and/or technical interest.
The reduced vertical dimensions of magnetic thin films and multilayers lead to major and often unexpected changes in magnetic properties and behavior. In addition to intrinsic scientific interest, these novel characteristics have direct relevance to current and projected technological needs. A detailed understanding of materials growth mechanisms is required for successful implementation of this technology. Chemical and crystallographic structure must be correlated with micromagnetic structure and dynamic response before the fundamental limits of device performance can be firmly established. The transmission electron microscope and related techniques continue to play a major role in these investigations.
David J. Smith is Regents' Professor of Physics and Astronomy, and Director of the John M. Cowley Center for High Resolution Electron Microscopy at Arizona State University. His long-term research has centered around the development and applications of atomic-resolution electron microscopy. Current research areas include semiconductor heterostructures, and magnetic and nanostructured materials.
Contact: Dept. of Physics and Astronomy, Arizona State University, Tempe, AZ 85287-1504. Ph: 480-965-4540; david.smith@asu.edu
In the high-resolution transmission electron microscope, electrons forming the image carry specimen information in the phase changes they undergo when scattered from the specimen (actually the potential field formed by the atoms composing the specimen). Although the electron phase is not a system observable (it is not gauge invariant), phase differences can be measured by interference experiments. A direct way is by electron holography, but the usual method is to form the image at optimum or Scherzer defocus. Then phase shifts introduced by the objective lens turn the relative phases of the waves into image peaks that correspond to atom positions. Whether these peaks can be individually distinguished depends on atom separation and the resolution of the micro-scope - uncorrected mid-voltage TEMs are limited to 1.9A resolution at 200 kV (1.7A at 300kV). Using electron imaging theory, we can reach sub-Angstroem levels of resolution by correcting for phase changes caused by objective lens aberrations. Experiments verify that resolution as high as 0.78A can then be achieved at 300keV - an improvement by a factor of two.
Michael O'Keefe, Ph.D., wrote the seminal computer code for simulation of HRTEM images (results published on the cover of Nature), and later used this knowledge of image formation to conceive and plan the One-Angstroem Microscope (OAM) at Lawrence Berkeley National Laboratory. Initial tests of the OAM, after correction of three-fold astigmatism, demonstrated the first achievement of sub-Angstroem resolution at 300keV (0.89A). Subsequent tests, with improved electron beam coherence, advanced OAM resolution to 0.78A and established the ability of sub-Angstroem resolution to image extremely light atoms by producing the world's first TEM images showing lithium atoms. Following the success of the OAM, he designed the HRTEM specifications that will allow the TEAM microscope proposed by the DOE-sponsored e--beam user centers to reach 0.5A resolution. Mike is currently spending a year at DOE HQ in the Office of Basic Energy Sciences.
Contact: : Lawrence Berkeley National Laboratory, Materials Science Division, 1 Cyclotron Road, Berkeley CA; maok_msa@comcast.net
Semiconductors are complex materials where a detailed and local understanding of the atomic and electronic structures is critical. As materials are being constrained to 0- and 1- dimensions and their surface to bulk ratio increases, the surface of the nanomaterials also becomes increasingly important to its overall properties. High resolution scanning transmission electron microscopy (STEM) and electron energy loss spectroscopy (EELS) are ideal tools with which to acquire this understanding. Using aberration-corrected STEM, the atomic structure of crystals (and defects associated with those crystals) can be imaged with a resolution of ~1, and using monochromated EELS, an energy resolution of ~0.15eV can be obtained to explore the band gaps and other electronic signatures of materials. These state-of-the-art techniques allow for the direct probing of individual dislocations in thin film semiconductors, where the local electronic structure is different just 1nm away from the dislocation. Low loss EELS can be used to study the effect on band gaps of semiconductors that have been constrained to low dimensions, such as nanowires and quantum dots. Furthermore, it has been recently shown that the STEM probe can be used to excite guided light modes in uniform nanowires (and presumably other uniform nanostructures) with higher spatial resolution than most optical techniques, thus providing a new tool for characterization of optical materials.
Nanotechnology has become a key component in the field of materials science. Rather than analyzing and determining the properties of bulk single or poly-crystals where the third dimension is assumed to be uniform, we must now analyze materials that have a finite size and shape in three dimensions, and not necessarily uniform in any of the directions. This new demand on materials characterization has led to the development of electron tomography for inorganic materials using Z-contrast imaging in the scanning transmission electron microscope (STEM). This technique involves taking a series of images of the sample at different tilt angles, normally ranging between -70 to +70 every 1 to 2 degrees, and using these two dimensional images to reconstruct a three dimensional volume of the sample. This tilt range may increase depending on the sample geometry and the holder used, but we are constantly battling against an artifact in the reconstruction called the missing wedge. This effect may be reduced greatly by performing dual axis tomography, or overcome completely using new holder technologies, but each technique has its pros and cons. These benefits and limitations will be discussed through examples of different inorganic materials.
Ilke Arslan received her Ph.D. in Physics from the University of California at Davis, and currently holds a Truman Fellowship at Sandia National Laboratories in Livermore, California. During her two years at the University of Cambridge as a joint Royal Society USA Research Fellow and National Science Foundation International Research Fellow, she helped to develop holder geometries to increase resolution in three dimensions for inorganic materials using STEM tomography. Her interests include semiconductors, catalysts, energy storage materials, and technique development in tomography, high resolution STEM, and EELS.
Contact: Energy Systems Department, Sandia National Laboratories, 7011 East Avenue, MS-9291, Livermore, CA 94550, 925-294-1469, iarslan@sandia.gov
The Focused Ion Beam technique has been successfully used for many years in the semiconductor industry for the evaluation of devices and failure analysis studies. However, the application of the FIB technique to more conventional materials has developed within the past 10 years. Microstructural characterization via analytical electron microscopy requires electron-transparent specimens that are usually prepared using conventional electropolishing techniques or using ion-milling/ion-polishing techniques. This presentation will describe the application of the FIB technique to the evaluation of an ODS molybdenum alloy, the characterization of a stress corrosion crack in a Ni-Cr-Fe alloy, the assessment of deformation, and the characterization of a complex stellite-steel clad interface structure.
A508 Gr4N are high Ni bainitic/martensitic forging steels that exhibit excellent toughness (low 47J transition temperatures) and good strength. The elevated Ni contents (~3.3%) of these steels, do not show enhanced irradiation damage response, in contrast to published observations for other Ni-containing low alloy steels. An investigation to understand the development of irradiation damage has been performed using the complementary analytical techniques of 3D-atom probe microanalysis, FEG-STEM XEDS microanalysis, small angle neutron scattering (SANS), positron annihilation lineshape analysis (PALA), along with post-irradiation annealing experiments to assess the recovery response of the steels. The steels evaluated contained either 0.3% or 0.02% Mn, so that it was possible to examine the effect of Mn on the extent of irradiation damage.
The results show that high flux irradiation leads to vacancy-related matrix damage and the formation of non-random distributions of solute within the matrix, the extent of which appears to depend on the Mn content of the steel. Post-irradiation annealing experiments coupled with PALA analyses and hardness measurements permitted the relative contribution of each hardening component to be identified. The data indicate that the high Ni levels content of the A5508 Gr4N steel does not enhance embrittlement or hardening, and suggest that the Mn level of the steel is an important factor in the development of the irradiation-induced microstructure.
Contact: Bechtel Bettis, Inc., Pittsburgh, PA. m.g.burke@att.net
Until quite recently the SEM could be used for imaging and for chemical analysis but it was not practical to get crystallographic information. Now there is a technique called Electron Backscattering Diffraction (EBSD), which is revolutionizing scanning microscopy, at least when it is used for the study of metals, ceramics and other crystalline materials. The technique and its applications will be reviewed.
Contact: Department of Materials Science and Engineering, Lehigh University. (610) 758-4231; jae5@lehigh.edu
Focused ion beam (FIB) based instruments are now routinely used for specimen preparation for a range of analytical instruments. DualBeam instruments (a FIB column and a scanning electron microscope (SEM) column on the same platform) can be used for unattended and automated site specific cross-sectioning or TEM specimen preparation. The SEM can be used for end-pointing any FIB technique via live or intermittent imaging. In addition, the synergistic use of the FIB with the SEM allows for automated acquisition of serial slices for subsequent 3D reconstruction and tomography of microstructure (via SEM imaging), crystallography (via EBSD) and/or elemental composition (via EDS). Automated and advanced digital patterning capabilities can be used to either remove or deposit material lithography or micro- and nano-prototyping. Examples of the methods and techniques mentioned above will be presented from a variety of materials.
Lucille A. Giannuzzi received her B.E. and M.S. from SUNY Stony Brook and her Ph.D. from The Pennsylvania State University. She joined the University of Central Florida in 1994, ending her career at UCF as Professor, Department of Mechanical Materials and Aerospace Engineering. She joined FEI Company in 2003 as a product marketing engineer for FIB/DualBeam where she continues to perform FIB-related research and product marketing.
Contact: FEI Company, 5350 NE Dawson Creek Drive, Hillsboro, OR 97124. (321) 663-3806; lucille.giannuzzi@fei.com
Microscopy has been critical to research in cardiovascular disease. This talk, aimed at the educated lay audience, reviews our current understanding of the causes of hardening of the arteries with particular emphasis on how microscopy has contributed to this understanding.
A discussion of the various schemes for gaining quantitative structural information microscopically from biological samples using my own work as practical examples and how to avoid some common mistakes I have run across over the years.
Most microscopy is now digital image based yet many microscopists still do not fully understand basic digital image concepts such as pixel depth, camera characteristics, and how to match microscope resolution, image capture resolution and image display resolution for maximum efficiency. Moreover, the basics of image formats (jpeg, jpeg2000, TIF, PNG, GIF, etc.) are critical but not understood. The image information is the data and so not understanding these critical concepts can lead to accumulation of artefactual data. This talk covers in a very general and basic way these concepts to provide the microscopist with sufficient information to avoid common pitfalls.
Contact: Department of Pathology, Vanderbilt University Medical Center, U2206 MCN, 1161 21st Ave, South, Nashville, TN 37232-2561. 615-322-5530; jay.jerome@vanderbilt.edu
Mineralization in vertebrates occurs normally in bone, calcifying cartilage and tendon, and dentin, cementum and enamel of the teeth. Vertebrate mineralization occurs through the interaction of inorganic calcium and phosphate ions with organic components synthesized and secreted to extracellular matrices by specialized cells of these various tissues. The principal organic constituent regulating mineral formation of all vertebrate tissues except enamel is collagen. The organic constituents of enamel mediating mineralization are amelogenin and enamelin. Largely through light and transmission electron microscopy, including high voltage microscopy and three-dimensional tomography, this presentation will describe the mechanism by which normal mineral formation occurs in association with collagen and amelogenin in the appropriate vertebrate tissues above. Reference to pathological mineralization, in muscle, skin, and other tissues, will also be made.
Tissue engineering is a relatively new and potential powerful means of augmenting, repairing, and replacing various tissues that may be congenitally defective, injured, diseased, damaged or otherwise impaired in the human body. The approach of tissue engineering commonly involves seeding isolates of specific cells onto a biodegradable polymer scaffold to form a cell/scaffold construct. The construct is subsequently developed in vitro or in situ for ultimate use as a possible replacement tissue. Bone and cartilage structures, such as a human digit or ear, have now been modeled by tissue engineering methods. The presentation will describe by light and electron microscopy, correlated with laser capture microdissection and gene expression, the tissue engineering of current models of human phalanges and ears. Compared to bone and cartilage in vivo, these models demonstrate several similarities in structure, composition, and response to mechanical forces and they suggest great promise for further advances in clinical applications.
Many bones of vertebrates normally adapt to changes in mechanical forces, including the force of gravity. Typically the mass of responsive bones increases or decreases with increasing or decreasing force, respectively. This presentation will describe compositional and structural effects on cultured normal bone cells flown in microgravity during a series of NASA Shuttle spaceflights, retrieved on landing and analyzed by molecular biological techniques and light and electron microscopy. The data will be compared to results from the same cultured bone cells maintained at normal (1G) gravity. The information obtained from the NASA flights provides insight into the means by which bone mass is lost by astronauts in spaceflight and can be extrapolated to the observed bone mass loss in individuals confined to bed for long periods of time or lacking exercise and other forms of physical activity.
William J. Landis, Ph.D., is a professor in the Department of Microbiology, Immunology and Biochemistry and in the Department of Orthopedic Surgery at the Northeastern Ohio Universities College of Medicine (NEOUCOM) in Rootstown, Ohio. He holds joint faculty appointments at Kent State University, the University of Akron, Case Western Reserve University and the University of Pennsylvania. Prior to his relocation to NEOUCOM eight years ago, he was an associate professor of Orthopedic Surgery and Anatomy and Cellular Biology at the Children's Hospital and the Harvard Medical School, Boston. He has research interests in biomineralization, tissue engineering, and the effects of mechanical forces on mineralized tissues, and he has published more than 125 peer-reviewed journal articles, book chapters, and reviews in these areas. His long-standing research programs are supported principally by the National Institutes of Health and the National Aeronautics and Space Administration. He has been a Senior Fulbright Scholar at the Weizmann Institute of Science in Rehovot, Israel, and the recipient of several honors and awards for his research studies. He is a member of numerous scientific organizations, including MSA, MAS, the New England Society for Microscopy (NESM), and the Microscopy Society of Northeastern Ohio (MSNO).
Contact: William J. Landis, Department of Microbiology, Immunology and Biochemistry, Northeastern Ohio Universities College of Medicine (NEOUCOM), Rootstown, Ohio. (330) 325-6685; wjl@neoucom.edu
For biologists, the two most common imaging modes are light and electron microscopy and in recent years there have been very exciting developments in each of these areas. For light microscopists the development of reporter molecules that can be genetically engineered into living cells has resulted in powerful insights into how cells work. At the EM level, developments in high resolution 3-D imaging such as cellular tomography are providing unprecedented views of the actual molecular mechanisms behind cell function. Our goal is to create a workable bridge between these two imaging modes so that the advantages of each can be used to their fullest extent. To observe a living cell by LM and then correlate that information with high resolution images from EM provides a confidence in the resulting data that cannot be matched by uncoordinated samplings by either method. From the EM side of the equation, it is essential that specimen preparation methods preserve the living structure with the greatest possible fidelity. This is where high-pressure freezing plays an important role. HPF machines have recently been developed to go between live imaging and fast freezing with high time resolution but there is much more that can be done to improve their performance. In this presentation, we report on some of our efforts to further develop correlative LM-HPF-EM imaging technology.
The goal of the research presented is to provide a high resolution structural context for the mitotic spindle in the intact cell to match the structural and functional information provided by genetics an structural proteomics. To help achieve this goal we use high pressure freezing as a method for preserving spindle ultrastructure. High pressure freezing (HPF) is one of the most significant advances in specimen preparation for biological electron microscopy since the development of glutaraldehyde fixation. Compared to conventional room temperature methods using glutaraldehyde, HPF provides more accurate morphological information as well as superior preservation of antigens for immunolabeling studies. Once frozen, the samples are processed at low temperature by freeze substitution and embedded in epoxy or methacrylate resins for sectioning. 3-D analysis can be performed by either reconstruction from serial thin sections or by cellular tomography. Cellular tomography is the preferred method of analysis because tomographic "sections" as thin as 2-4 nm can be selected from the computer 3-D model. In this presentation, we will review the basics of HPF, including recent innovations that permit correlative LM/EM analysis with about 5 sec. time resolution. Results from studies of mitotic cells of yeasts, /C. elegans, Drosophila/ and other cell types will be presented, with particular emphasis on recent published work by Eileen O'Toole (Boulder, Colorado 3-D EM Lab) and Thomas Mueller-Reichert (Max Planck Institute, Dresden, Germany) on mitotic ultrastructure in /C. elegans.
Kent McDonald received his Ph.D. in Botany from the University of California, Berkeley in 1972. Following a year teaching at UCLA, he took a Post-doctoral position at the University of Colorado, Boulder. In 1975, he re-focus his research on the cell biology of mitosis which led him back to Berkeley in 1979 to work on correlative light and electron microscopy of PtK cells and diatoms. In 1987 he returned to Boulder to join the High Voltage EM Lab and at this time realized the importance of cryofixation by high pressure. In 1993 he moved back to Berkeley to assume the Directorship of the campus Electron Microscope Laboratory. His current research interest is improving the instrumentation for correlative light and electron microscopy using high pressure freezing and tomographic 3-D imaging. In 2008 he hopes to learn the art of vitreous cryosectioning and apply that skill to several research questions with collaborators at UC Berkeley.
Contact: Electron Microscope Laboratory, 26 Giannini Hall MC3330, University of California, Berkeley, CA 94720-3330. (510) 642-2085; klm@berkeley.edu
Infectious diseases are the leading cause of death worldwide and the third leading cause in the US; many can be classified as emerging diseases. Some may be caused by truly novel pathogens, in other cases, the causative organisms have been present for many years, but have escaped detection until recently. Still others represent the re-emergence of known pathogenic organisms after a long period of quiescence. The mention of emerging pathogens brings to mind sensational, exotic and feared microorganisms such as Ebola virus, human immunodeficiency virus (HIV), hantavirus, West Nile virus, Yersinia pestis (plague), and prion diseases such as bovine spongiform encephalitis (BSE, mad cow disease) which have been associated with variant Creutzfeldt-Jakob disease (CJD) in humans. However, other organisms that have been known for some time can be classified as emerging pathogens as they continually mutate, recombine, and adapt, like influenzavirus, causing misery and death. A major category of emerging diseases is that of drug-resistant organisms. Changes in technology permit organism spread by contaminated water and air conditioning systems, by surgical and diagnostic instruments, or by transplantation. Geographic spread of disease organisms through more widespread human travel, transport of vectors in shipping containers, and increased mobility of insects and animals accounts for some emerging diseases. Food-borne illnesses are a world wide problem. In addition to agents that actually invade and cause disease, numerous organisms cause tremendous morbidity and some mortality through toxin production. Increased awareness due to better detection and identification methods has brought these organisms to the forefront. Microscopy techniques for detection of organisms are rapid and do not require specific probes. Electron microscopy is particularly useful for viral agents. It can visualize a wide variety of viruses at once, including non-cultivable and unexpected ones. It does not require antibodies or nucleic acid reagents for identification, and it is rapid; negative staining of fluid samples can be accomplished in a matter of minutes to a couple of hours. Thin sectioning of cells can be accomplished in one to two days. Finally, speed of microscopical methods and lack of requirements for probes are the reasons microscopy laboratories are being asked to participate in the surveillance for bioterrorism agents-horrible and feared examples of emerging diseases.
Sara Miller, Univ Georgia BS (Microbiol/Chem) 1968. Univ Georgia PhD (Microbiol) 1972. Director, EM Diagnostic Virology Lab; Director, Surgical Pathology EM Lab, Duke Hospital. Director, EM/IEM Cancer Ctr Shared Resource, Duke Univ Med Ctr. Assoc Res Prof, Microbiol 1983-; Assoc Clin Prof, Pathol 1994-.
Contact: Sara Miller, Duke Medical Center, Pathology, Box 3712, Durham, NC 27710. (919) 684-3452; saram@acpub.duke.edu
In electron tomography (ET) a set of projection images from different viewing angles is recorded using a transmission electron microscope. These images can then be used to reconstruct the three-dimensional structure of the specimen by computed back projection. ET is a rapidly developing technique that is playing an increasingly important role in both the materials and life sciences. Broader application of the technique and continued innovations are diversifying ET. In this presentation we give an introduction into the technique, discuss strengths and limitations, provide a broad overview of directions in both physical and biological ET, and report about technical progress and a few exemplary applications.
Rapid freezing of cells and tissues can provide outstanding structure preservation and good time resolution of dynamic cellular processes. Electron tomography of rapidly frozen specimens (cryo-ET) is a powerful technique for imaging biological structures in their native state. Cellular cryo-ET can provide 3-D information about a pleomorphic biological specimen with much potential for the characterization of biological structures and macromolecular assemblies in situ. The cutting edge approach of cryo-ET in combination with image processing techniques, such as 3D correlation averaging and structural classification has already provided new views of the 3D structure of cellular organelles and molecular machines at a molecular level. Such information can provide detailed insights into the structural basis and ultimately the function of many cellular processes.
Daniela Nicastro received her Ph.D. in Biology from the Ludwig-Maximilians University in Munich, Germany in 2000. Following 3 years in the lab of Prof. Baumeister at the Max-Planck Institute for Biochemistry in Munich (1998-2001), she took a post-doctoral position at the University of Colorado, Boulder. Since 2006, she is Assistant Professor of Biology at Brandeis University. Her lab is studying the three-dimensional structure of macromolecular machines, organelles and cells using cryo-electron tomography, focusing on the structure and function relationships of macromolecular complexes in situ, i.e. in their native environment. Areas of interest include the structure of eukaryotic flagella and the molecular motor dynein, the cytoskeleton and bacteria, as well as the development of cryo-EM and image processing techniques.
Contact: Brandeis University, Department of Biology, MS 029, P.O. Box 549110, Waltham, MA 02454-9110. (781) 736-2408; nicastro@brandeis.edu
My research interests have always been at the interface between biological specimens and physical instrumentation, generally microscopes, particularly 3D microscopes. While at Madison, I have worked to improve the performance of both high-voltage transmission electron microscopes, and low-voltage, high-resolution scanning electron microscopes.
More recently, I have been concentrating on improvements in the confocal scanning light microscope. This instrument permits one to make images of a single plane in a thick, fluorescent specimen. By collecting data from many adjacent planes, it is possible to produce real 3D images. More importantly, and unlike any sort of electron microscopy, it is possible to produce such images from specimens that are living and changing.
The biggest limitation to the use of the confocal microscope on living specimens is that the interaction of the exciting light and the fluorescent dye molecules can produce toxic substances that damage the cell. The only solution is to count the fluorescent light more efficiently so that the amount of excitation needed to make a usable image is reduced. I am working with and Andor Technologies and E2V to develop a new and improved version the Electron-multiplier CCD to replace the PMT in the single-beam confocal.
I have just finished editing the Third Edition of the Handbook of Biological Confocal Microscopy. More information can be found at http://www.zoology.wisc.edu/faculty/Paw/Paw.html
Contact: University of Wisconsin, Zoology Research Building Room 223, 1117 Johnson Ave., Madison, WI 53706. (608) 263-3147; jbpawley@facstaff.wisc.edu
Antigen sampling M cells (membranous epithelial cells) are present in the follicle associated epithelium (FAE) of many mucosae but their presence in the conjunctiva was controversial. M cells play a key role in the initiation of the mucosal immune response by sampling antigens and translocating them to underlying lymphocytes and antigen-presenting cells. In addition, M cells represent a site of entry for opportunistic pathogens such as Shigella, Salmonella, and HIV. Our laboratory has used a combination of stereo, wide-field, and confocal fluorescent microscopy and transmission and scanning electron microscopy to demonstrate that the FAE of the Guinea pig and rabbit conjunctiva contain M cells with morphological and functional characteristics similar to those in other mucosae.
Tom Phillips received his B.Sc. in Chemistry from Indiana University-Bloomington, a Ph.D. in Pharmacology from Northwestern University, and did his postdoctoral training in Anatomy & Cell Biology at Harvard Medical School. He is a Professor of Biological Sciences at the University of Missouri. He is also Director of the campus-wide light microscopy imaging facility. In addition to his work on the ocular mucosa, Tom has worked on quick-freezing of synapses, differentiation of intestinal cell lines, intracellular trafficking in transgenic plants and liver cells, and bacterial interactions with mucosal tissues.
Contact: Division of Biological Sciences, 2 Tucker Hall, University of Missouri, Columbia, MO, 65211-7400. (573) 882-4712; phillipst@missouri.edu
The US Food and Drug Administration (FDA) has regulatory authority over a wide range of consumer products including most foods, pharmaceuticals, biologics, veterinary drugs, medical devices and cosmetics. The FDA's Forensic Chemistry Center (FCC) is a unique forensic laboratory responsible for the analysis of those products when there is a concern related to product tampering, counterfeiting or fraud. Since before the tragic events of "9-11", the FCC has also devoted considerable additional efforts directed to the detection and research of counter terrorism measures related to FDA regulated products. Due to the uniqueness and diversity of sample types related to forensic investigations, the use of stereoscopic and polarized light microscopy as well as scanning electron microscopy and energy dispersive x-ray spectrometry have been shown to be invaluable instruments. This presentation will cover the microscopic and macroscopic analysis of selected forensic cases using light and scanning electron microscopy, computer-assisted Image Analysis, Energy Dispersive X-ray Spectrometry and variable frequency / alternative light source analyses. Topics will include numerous case by case applications ranging from homicide to the ridiculous "I can't believe anyone would do that" cases. Examples of in-house supporting research related to several cases will also be discussed.
S. Frank Platek is a research biologist and microscopist with the US FDA's, Forensic Chemistry Center and serves at the Microscopy and Microanalysis Team Leader. He holds a BS in Biology and Agriculture from Murray State University and an MS in Industrial Hygiene from the University of Cincinnati's College of Medicine. Before joining the FDA, he served fifteen years as a research biologist with the National Institute for Occupation Safety and Health (NIOSH) specializing in SEM/TEM/EDS analysis of particles and fibers and their relationship to pulmonary pathology. Since 1993, he has served as a member of the editorial review board of the Journal, SCANNING, and has organized and chaired the Scanning Microscopy in Forensic Science Session and Short Course for the International SCANNING meeting. Mr. Platek has been an adjunct faculty instructor at Northern Kentucky University for more than 26 years teaching electron microscopy and x-ray microanalysis. He has served as a national touring speaker for the Microbeam Analysis Society and is currently a lecturer in the Lehigh Microscopy School at Lehigh University. He is also a member of numerous professional societies including the Microscopy Society of America, American Academy of Forensic Sciences and Mid-Western Association of Forensic Scientists.
Contact: S. Frank Platek, US FDA Forensic Chemistry Center, 6751 Steger Drive, Cincinnati, Ohio 45237-3097, (513) 679-2700, frank.platek@fda.hhs.gov
Science teachers want and need help from scientists, and a simple light microscope is a wonderful way to introduce the methods and excitement of science. Project MICRO (Microscopy In Curriculum -- Research Outreach) is an MSA program that introduces middle school students to the microworld. It's based on Microscopic Explorations, a very successful teachers' manual developed in collaboration with the Lawrence Hall of Science, one of the best science education sources in the U.S. MICRO can help LASs organize outreach programs (there are 7 already) or support LAS members' individual, university, or corporate efforts. Detailed information on MICRO is available at http://www.microscopy.org/ProjectMICRO.
Caroline received her BA and MA in Zoology from the University of California at Berkeley in the 50s, when electron microscopy was new. She taught EM methodology and managed a central facility there until her retirement in the early 90s. Project MICRO is her primary retirement project; she manages it from a small town on the California coast.
Contact: Box 117, Caspar, CA 95420. (707) 964-9460; schooley@mcn.org
Fungi are fundamentally recyclers. Their main function in the environment is to break down complex materials, which allows the components to be re-used by other organisms. These complex materials include dead plants, dead animals, building materials, valued artifacts of civilization and any number of other things. Problems arise when these organisms invade the built environment, either work or living spaces. Various methods, such as air sampling, have been commonly used to estimate the density of fungi in a structure. Volumetric sampling may indicate high levels of fungi or one particular fungus in a building compared to the outdoor environment or some predetermined standard. This method may indicate the presence of viable fungal conidia or hyphal fragments in the air column but it cannot identify sites of colonization. Surface cultures may indicate the presence of viable fungal propagules but do not prove colonization. Surface sampling for light microscopy using clear adhesive tape mounts may demonstrate the presence of colonizing fungi. The methodology, such as types of tape and optics employed may affect the results obtained. Examination of tape samples from environmental surfaces may show the level of colonization and, in many cases, allow for identification of colonizing species. Scanning electron microscopy studies of suspect materials may determine the nature of surface features and contamination not readily identifiable in the light microscope. Suspect materials may be shown to be biological in nature or non-biological surface. Microanalysis of materials may yield clues to the origin of non-biological contamination. Rapid and accurate analysis of suspect materials on indoor surfaces is vital to the identification of potential fungal colonization sites. These data may be used as an aid to determining an appropriate course of action.
Automobile air conditioning systems might be considered an extreme environment for many microorganisms. Organisms surviving and proliferating in these systems may be presented with temperature changes ranging from sub-zero to over 140oF, water activity from saturation to dryness and a nutrient complexity including varying levels of hydrocarbons. Microbial communities may develop in these systems and sometimes proliferate to the extent of massive colonization and production of objectionable odors. In a few instances microorganisms emanating from ACS have been associated with hypersensitivity pneumonitis and other allergic reactions. We have demonstrated that foam insulation and glues, in particular, on system insulations may be colonized by fungi such as Aspergillus, Aureobasidium, Cladosporium, and Penicillium. Such fungi often are implicated in colonization of similar substrates in buildings categorized with the sick building syndrome. Combined light microscopy, scanning and transmission electron microscopy and culture techniques have provided profiles of the microbial communities which inhabit some automobile air conditioning systems.
Robert Simmons is a native of Atlanta, Georgia. He earned his Bachelor of Science (Hons) degree in biological sciences at the University of Ulster, and continued with MS and Ph.D. degrees at Georgia State University. He joined the Biology Department at Georgia State University in 1983 and is the Program Director for Biological Imaging. His main research involves the interaction of microorganisms with the human environment, with an emphasis on fungi and air handling systems. Recent work includes investigation of colonization of hydrogel contact lenses by Fusarium and other fungi.
Contact: Department of Biology, College of Arts and Sciences, P.O. 4010, Georgia State University, Atlanta, GA 30302-4010. (404) 413-5349: rsimmons@gsu.edu