Life Sciences Commons^™

Scanning Electron Microscopy Of The Small Intestine Mucosa In Children With Celiac Disease After Long-Term Dietary Treatment, M. Morroni, A. Sbarbati, G. D'Angelo, C. Catassi, P. L. Giorgi, S. Cinti

Scanning Microscopy

Jejunal mucosal specimens from twenty children with celiac disease were studied by light microscopy (LM), scanning electron microscopy (SEM), and transmission electron microscopy (TEM) after one year of dietary treatment. An ultrastructural morphometric study was performed in five patients who had an intestinal permeability (IP) test. Seventeen patients were tested for serum antigliadin antibodies (AGA). In ten children, in whom LM showed partial villous atrophy, SEM and TEM examination confirmed the lesion. In the second group (10 children) with normal morphology at routine LM, SEM showed lesions of variable degree in 70% of cases. The morphological ultrastructural investigation showed good …

A Scanning Electron Microscopy Analysis Of Human Cytotoxic Cell Subsets And Of Their Mode Of Conjugation With Tumor Cell Targets, Walter Malorni, Giuseppe Arancia, Francesca Iosi, Gianfranco Donelli, Daniela Zarcone, Alessandro Moretta, Carlo Enrico Grossi

Scanning Microscopy

In this study we describe the surface features of non-MHC (Major Histocompatibility Complex)-restricted cytotoxic cells isolated from human peripheral blood. Purified populations of CD3^-, natural killer (NK) cells were allowed to interact with NK-sensitive (K562) and NK-resistant (THP-1-0) tumor cell targets. The type of effector to target cell binding was investigated by scanning electron microscope (SEM) analysis. A different interaction with the effectors is described for NK-resistant targets in comparison with NK-susceptible tumor cells. SEM was also used to investigate the relationship between interleukin 2 (IL2)-activated cytotoxic cells (lymphokine-activated killer, LAK, cells) and the tumor targets. We also …

Scanning Electron Microscope With A Single-Polepiece Lens, V. Kolařík, I. Müllerová, M. Lenc

Scanning Microscopy

The design of an ultra-high vacuum scanning electron microscope (UHV SEM) with a single-pole-piece lens underneath the specimen is described with the possibility to guide backscattered (BSE) and secondary electrons (SE) which originate in the magnetic field of the single-polepiece lens to the detectors. Our new design of the single-pole-piece lens and in-lens deflection coils closely satisfy the condition of a variable axis immersion lens (VAIL), which results in very low deflection aberrations.

Early Phase Changes During The Setting Of High Copper Amalgams, T. Ruzickova, J. Had

Scanning Microscopy

X-ray diffraction analysis has been used to evaluate the phase composition of two (spherical and lathe cut) HCSC amalgam alloys and early phase changes in these amalgam in the time interval 2.5 min to 7 days after trituration. A method appropriate for the evaluation of these changes was developed. Only two phases were found in alloys Valiant and Ana 2000: gamma(Ag₃Sn) and epsilon(Cu₃Sn). In amalgams, no diffraction peaks were observed corresponding to gamma 2 phase in the time interval form 2.5 min to 7 days after trituration. The relative concentration changes of the reaction products of …

Complex Motor Dynamics And Control In Multi-Looped Negative Feedback Systems, Anne Beuter, John Milton, Christiane Labrie, Leon Glass

WM Keck Science Faculty Papers

Experiments were performed in normal and Parkinsonian subjects who were asked to maintain a constant finger position using time-delayed visual feedback. The finger position showed complex dynamics, with characteristic differences between normal and Parkinosonian subjects. Here we discuss some of the theoretical issues that must be resolved in order to understand the mechanisms that underlie the generation of these complex signals.

Muscle Activities That Stretch The Mind, James L. Hanegan, Heather Mckean

Biology Faculty Publications

No abstract provided.

Detection In Soil Of A Deletion In An Engineered Dna Sequence By Using Dna Probes, Janet K. Jansson, William E. Holben, James M. Tiedje

Biological Sciences Faculty Publications

Two Pseudomonas strains were engineered to contain the nptII gene and plasmid vector sequences in their chromosomes. After incubation of these strains in nonsterile soil, total bacterial DNA was isolated and analyzed by Southern blot hybridization with the nptII gene and the plasmid vector as probes. In addition to the expected bands of hybridization, a new band corresponding to the loss of vector sequences from the chromosome while retaining the nptII gene was observed for one of the strains. The more stressful conditions encountered in soil appeared to increase the frequency of loss of the vector sequences …

A Simulation Of Secondary Electron Trajectories In Solids, M. Kotera, T. Kishida, H. Suga

Scanning Microscopy

A Monte Carlo calculation model is introduced to simulate not only the primary electron behavior but also the secondary electron cascade in a specimen bombarded with an electron beam. Electrons having energy greater than 0.1keV are treated as "fast electrons" and the single scattering Monte Carlo model is adopted. Electrons having energy smaller than 0.1keV are treated as "slow electrons" and the electron cascade Monte Carlo model is used. The calculated results for the energy distribution of secondary electrons, and primary electron energy dependence of the total secondary yield and the backscattering yield are in good agreement with experimental results.

Identification And Characterization Of Peptidoglycan-Associated Proteins In Neisseria-Gonorrhoeae, Stuart A. Hill, Ralph C. Judd

Biological Sciences Faculty Publications

The principal proteins associated with Neisseria gonorrhoeae peptidoglycan (PG), as identified by sodium dodecyl sulfate-polyacrylamide gel electrophoresis, are the following: two proteins at approximately 90 kilodaltons (kDa), single major species at both 60 and 44 kDa, a 34- to 36-kDa protein, and three proteins between 28 and 32 kDa. A protein analogous to Escherichia coli Braun lipoprotein was not detected with gonococcal cell wall preparations. The identity of the PG-associated proteins was confirmed immunologically with antibody generated against purified cell walls. Two types of protein species, dithiothreitol extractable (the majority) and alkylation dependent (primarily the 34- to 36-kDa protein), appeared …

Foraging Decisions In A Patchy Environment, Eric Charnov

Biology Faculty & Staff Publications

This is a Science Citation Classic commentary on the Marginal Value Theorem [Charnov, 1976]

Strontium And Bromide As Tracers In X-Ray Microanalysis Of Biological Tissue, Joanna Wroblewski, Samuel Sagström, Helmy Mulders, Godfried M. Roomans

Scanning Microscopy

Since energy dispersive X-ray microanalysis cannot distinguish between isotopes of the same element, alternative methods have to be used to get information similar to that obtained in experiments with radioactive tracers. In the present study, strontium was used as a tracer for calcium, and bromide as a tracer for chloride. Rats were injected with strontium chloride in vivo, and the uptake of strontium in the acinar cells of the submandibular gland was studied. Eventually a Sr/Ca ratio of 0.3 was reached. In some animals, secretion of mucus had been elicited by stimulation with isoproterenol 4 h prior to injection …

Backscattered Electron Imaging Using Single Crystal Scintillator Detectors, R. Autrata

Scanning Microscopy

The image obtained by the detection of backscattered electrons (BSE) becomes an indispensable complement to the correct interpretation and more precise reconstruction of the surface of the specimen and its material composition. The BSE are carriers of information which is dependent on their angular and energy distribution. The choice of a certain type of BSE and their efficient detection make it possible to record the desired information with a different grade of quality. The knowledge of the angular and energy distribution of BSE is necessary for the adjustment of the correct position of the BSE detector with regard to the …

Bone Lining Cells: Structure And Function, Scott C. Miller, Louis De Saint-Georges, Beth M. Bowman, Webster S. S. Jee

Scanning Microscopy

Bone lining cells (BLC's) cover inactive (nonremodeling) bone surfaces, particularly evident in the adult skeleton. BLC's are thinly extended over bone surfaces, have flat or slightly ovoid nuclei, connect to other BLC's via gap junctions, and send cell processes into surface canaliculi. BLC's can be induced to proliferate and differentiate into osteogenic cells and may represent a source of "determined" osteogenic precursors. BLC's and other cells of the endosteal tissues may be an integral part of the marrow stromal system and have important functions in hematopoiesis, perhaps by controlling the inductive microenvironment. Because activation of bone remodeling occurs on inactive …

Practical Aspects Of Automatic Orientation Analysis Of Micrographs, N. K. Tovey, P. Smart, M. W. Hounslow, X. L. Leng

Scanning Microscopy

Techniques to analyse the orientation of particulate materials as observed in the scanning electron microscope are reviewed in this paper. Emphasis is placed on digital imaging, processing, and analysis methods, but many secondary electron images are not amenable to traditional image processing as adequate thresholding is often difficult to achieve. Evaluation of the intensity gradient at each pixel offers an alternative approach, and this method is described in detail including the latest developments to generalize the technique. Practical points in the acquisition, processing and analysis of the images are considered and several images, including both synthetically generated and actual back-scattered …

Osteoclast Features Of Cells That Resorb Demineralized And Mineral-Containing Bone Implants In Rats, Cedo M. Bagi, Scott C. Miller

Scanning Microscopy

The comparative temporal tissue response to demineralized bone matrix powder (DBP) and devitalized mineral containing bone powder (MCP) implanted subcutaneously in rats was studied. The tissue response to implanted DBP followed the well described endochondral osteogenic pathway and included the appearance of osteoblasts and osteoclasts. On the other hand, implanted MCP resulted in the appearance of a large population of giant cells that resorbed the implants. At later times (3-4 weeks), most of the cells in the MCP implants appeared as typical foreign body giant cells with extensive membrane foldings, usually away from bone surface. Some cells did, however, have …

Structural And Compositional Changes In Aging Bone: Osteopenia In Lumbar Vertebrae Of Wistar Female Rats, M. Silbermann, M. Safadi, D. Schapira, I. Leichter, R. Steinberg

Scanning Microscopy

Changes in vertebral bone mineral content and density during aging were quantified in female Wistar rats. This study represents a longitudinal follow up utilizing single photon absorptiometry for the measurement of bone mineral content (BMC), quantitative computed tomography (OCT) for the measurement of bone mineral density (BMD), and image analysis histomorphometry for the measurement of trabecular bone volume (TBV) and bone cortical area (BCA). The above measurements were accompanied by biochemical assays of calcium concentrations in the respective bones. All aging animals experienced significant decreases in BMC, BMD, TBV, BCA and in the calcium content of their bones. The above …

Bacillus-Shaped Deposits Composed Of Hexahedrally Based Crystals In Human Dental Calculus, T. Kodaka, A. Hirayama, K. Miake, S. Higashi

Scanning Microscopy

In human supra- and subgingival calculus, bacillus-shaped deposits showing various rocky-pile forms composed of hexahedrally based crystals were observed by scanning electron microscopy. The crystal size measured approximately 0.1 - 1.5 μm. The electron probe microanalysis always detected calcium, phosphorous, and magnesium. Their molar ratios resembled those of magnesium-containing whitlockite and moreover the crystals also gave the electron diffraction pattern of whitlockite. The bacillus-shaped deposits happened to coexist with the intracellular calcifying microorganisms, furthermore, oral microorganisms partially replaced by the hexahedrally based crystals were found. The crystal deposits were never seen in the surface layers of calculus exposed to the …

Microprobe Analysis Of Element Distribution In Bovine Extracellular Matrices And Muscle, M. B. Engel, H. R. Catchpole

Scanning Microscopy

The concentrations of some essential elements, Na, K, P, S and Cl were determined by microprobe analysis in bovine extracellular matrices of cartilage, tendon and elastic tissue (ligamentum nuchae) and in muscle cells. The values for the different tissues were compared and related to the blood electrolyte concentrations. Among the connective tissues the highest Na and lowest Cl values were found for cartilage which bears a high negative charge. The lowest concentrations of these elements occurred in elastic tissue which is relatively non-polar. In the three extracellular matrices sodium levels exceeded potassium. In myofibers potassium was the major cation at …

Data Acquisition And Presentation In Scanning Nuclear Microprobe Analysis, K. G. Malmqvist, N. E. G. Lövestam, J. Pallon, U. A. S. Tapper

Scanning Microscopy

The data acquisition is a very important part of the scanning nuclear microprobe instrument. To make full use of the potential of the technique an adequate system for acquiring, storing, processing and presenting the data is a prerequisite. Various principles applied are presented including the list mode approach, which facilitates flexible off-line data processing. As in the case of the electron probe the beam-induced effects in the sample may be substantial and the list mode acquisition can then also be used to monitor and correct for any such effects. A comprehensive system for scanning nuclear microprobe control and data acquisition, …

Quantitative Measurement From Vascular Casts, Ralph G. Kratky, Christine M. Zeindler, Dorian K. C. Lo, Margot R. Roach

Scanning Microscopy

A review of quantitative measurements show casting materials shrink from 0.2 - 20% and have viscosities ranging from 1.4 - 100,000 centipoise. Blood vessels have highly variable mechanical properties. Some microvessels are very stiff having little change in dimensions with pressure. Larger vessels generally change diameter significantly but show highly variable changes in length with pressure. Perfusion fixation does not fix the dimensions of blood vessels. Dog carotid arteries well fixed with glutaraldehyde at physiologic dimensions retain ≈20% of their elastic recoil circumferentially and ≈30% longitudinally. We recommend vascular casting as a method of accurately measuring the vasculature if care …

Oxalate Crystallization In The Kidney In The Presence Of Hyperuricemia, Shinshi Noda, Kenichi Hayashi, Kousaku Eto

Scanning Microscopy

It has been a long time since uric acid was suggested to be a promoting factor in calcium oxalate stones, and a number of in vitro studies have been carried out on the relationship between uric acid or urate and calcium oxalate.

Concerning in vivo studies, urate or calcium oxalate stone-forming diets were given alone in most cases, and diets that induce formation of stones with different composition have not been given in combinations. We administered a low-concentration oxalemic diet, and a mixed diet containing oxalic acid and uric acid, and biochemically and histologically studied the effects of oxalate and …

Surface Heterogeneity Of Tumor Cells And Changes Upon Ionizing Radiation, Z. Somosy, Orsolya Csuka, Tamara Kubasova, J. Kovács, G. J. Köteles

Scanning Microscopy

Heterogeneous distribution of surface domains is a characteristic feature of the tumor cell surface and the distribution differs from that of normal cells. During the malignant transformation the heterogeneity may change or disappear. Cell lines with various metastasizing capacities show different distributions of membrane domains or other differences in membrane or surface organization. We have demonstrated that the amount and distribution of negatively charged sites of B 16 melanoma membranes changed upon ionizing radiation (X-ray, ⁶⁰Co-gamma). In the case of the P 388 lymphoma, however, only the amount of negatively charged sites change after irradiation, the distribution remains unaltered. …

The Physical State Of Potassium In The Human Lymphocyte: A Review, William Negendank

Scanning Microscopy

Studies of the effects of chemical potential, temperature, and metabolic perturbation on static ion contents, kinetics of the approach to equilibrium, and kinetics of ionic self-exchange in human lymphocytes are reviewed. The results contradict the classical concept of cell ion and water physiology, the membrane-osmotic, pump-leak theory, and are re-interpreted by an adsorption model of the cell. In this model, most of cell water exists in a physical state sufficiently ordered to reduce the partition function of dissolved ions, and most of cell potassium is associated with fixed charges on macromolecules. Competing adsorption of potassium and sodium is cooperative and …

Gastrointestinal Surface Changes: Interpretation Problems And Indexing Possibilities (A Review), C. J. Pfeiffer, O. Bulbena

Scanning Microscopy

The purpose of this review on state-of-the-art and new perspectives on the use of scanning electron microscopy (SEM) in gastrointestinal pathology is to discuss the possibility of developing an index for quantitatively grading mucosal epithelial injury. This topic is reviewed within the framework of ulcer indices previously developed for gross lesions, where analogous problems exist, and in relation to the transmission electron microscope staging of epithelial cell pathology. If such an index could be developed it would increase objectivity and standardization of data analysis from laboratory to laboratory, and would allow for quantitative and statistical analysis of morphometric data. It …

Scanning Tunneling Microscopy And Fabrication Of Nanometer Scale Structures At The Liquid-Gold Interface, J. Schneir, H. H. Harary, J. A. Dagata, P. K. Hansma, R. Sonnenfeld

Scanning Microscopy

The Scanning Tunneling Microscope (STM) can image gold surfaces covered with a variety of liquids. This paper reviews the results obtained using the STM to image gold surfaces covered with liquid. These results include the creation of 10 nm structures, images of the electrochemical process of electroplating, and the production of atomically flat Au (111) surfaces. We conclude that in the future STM will find further application in the area of nanostructure fabrication and electrochemistry. The trend in the field is toward greater control of the electrochemical environment.

Morphology And Chemical Composition Of Dental Calculi Mainly Composed Of Whitlockite, Toshiro Sakae, Hirotsugu Yamamoto, Hiroyuki Mishima, Takashi Matsumoto, Yukishige Kozawa

Scanning Microscopy

The morphology and chemical composition of two subgingival calculus samples, which were composed of magnesium-whitlockite with a Mg/Ca molar ratio of approximately 0.1 as shown by X-ray powder diffraction, were analyzed semiquantitatively using energy-dispersive spectroscopy (EDS) combined with scanning electron microscopy (SEM). The Ca/P molar ratio values for 33 EDS-analyzed materials ranged from 1.24 to 2.03 with an average of 1.49, and the (Mg+Ca)/P molar ratio values ranged from 1.43 to 2.28 with an average of 1.63. The average Mg/Ca molar ratio was 0.10, a value very close to that obtained by X-ray diffraction analysis.

The EDS-analyzed materials were grouped …

Porophyllum Pygmaeum (Asteraceae), A Distinctive New Species From Southern Nevada, David J. Keil, James D. Morefield

Biological Sciences

Porophyllum pygmaeum is a new species from coarse calcareous soils of the Desert National Wildlife Range in Clark Co., Nevada. It has subterete leaves that contain a continuous double layer of palisade mesophyll surrounding a central area of larger, achlorophyllous, polyhedral parenchyma cells and veins. The hollow foliar oil glands lie just below the abaxial epidermis and are deeply invaginated within the parenchyma layers. Porophyllum pygmaeum is a tetraploid (n = 24) perennial herb that apparently is most closely related to P. greggii a hexaploid herbaceous species of western Texas with much longer and narrower leaves. In its fleshy subterete …

The Effects Of Site Quality On Breeding-Site Fidelity In Bobolinks, Eric K. Bollinger, Thomas A. Gavin

Eric K. Bollinger

We compared breeding-site fidelity of Bobolinks (Dolichonyx oryzivorus) at two low-quality sites (Bald Hill and Shackelton Point, BH +SP) with that at one high-quality site (Moore Road, MR) in central New York. Yearly density of fledglings at Moore Road was more than six times the density at Bald Hill and Shackelton Point. Furthermore, individual residents fledged 50-70% more young at the high-quality site. At Moore Road, 70% of the males and 49% of the females returned one or more times, compared with 44% of the males and 25% of the females at the low-quality sites. Successful residents (i.e. those fledging …

Distribution Patterns Of Hp1, A Heterochromatin-Associated Nonhistone Chromosomal Protein Of Drosophila, T James, J Eissenberg, C Craig, V Dietrich, A Hobson, Sarah C.R. Elgin

Biology Faculty Publications & Presentations

We have previously reported the identification of a nonhistone chromosomal protein (nhcp-19; now called HP1) preferentially associated with the heterochromatin of Drosophila melanogaster. A detailed study of the HP1 distribution pattern on polytene chromosomes by immunofluorescent staining, using monoclonal antibody C1A9, has been carried out. The results indicate that this protein is found within the centric beta-heterochromatin, in cytological regions 31, 41 and 80, and throughout polytene chromosome 4. Staining of telomeres is frequently observed, those of chromosome arms 2R and 3R and the X chromosome being the most conspicuous. Analysis of a fourth chromosome insertional translocation T(3;4)f/In(3L)P confirms an …

Review: 'Deepening Christian Life: Integrating Faith And Maturity', William P. Roberts

Religious Studies Faculty Publications

No abstract provided.