127 results on '"Dunn, B. E."'
Search Results
2. The cpn60 heat shock protein homologue of H. pylori
- Author
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Dunn, B. E., Hunt, Richard H., editor, and Tytgat, Guido N. J., editor
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- 1994
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3. DISRUPTION OF TIGHT JUNCTION PROTEINS MEDIATED BY H. PYLORI EXTRACTS
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Dunn, B. E., Vakil, N. B., Parlow, M. H., Hahn, B. L., Krishnamurthy, P., Bhattacharyya, S., and Phadnis, S. H.
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- 1999
4. COST MINIMIZATION ANALYSIS OF A TELEMEDICINE SERVICE
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Agha, Z, Weinstein, R S, and Dunn, B E
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- 1998
5. Synthesis and activity of Helicobacter pylori urease and catalase at low pH
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Bauerfeind, P, Garner, R, Dunn, B E, and Mobley, H L T
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- 1997
6. Structure, function and localization of Helicobacter pylori urease
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Dunn, B. E. and Phadnis, S. H.
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Vaccines ,Bacterial Proteins ,Helicobacter pylori ,Cell Membrane ,Humans ,Urease ,Heat-Shock Proteins ,Research Article ,Helicobacter Infections ,Subcellular Fractions - Abstract
Helicobacter pylori is the causative agent of most cases of gastritis. Once acquired, H. pylori establishes chronic persistent infection; it is this long-term infection that, is a subset of patients, leads to gastric or duodenal ulcer, gastric cancer or gastric MALT lymphoma. All fresh isolates of H. pylori express significant urease activity, which is essential to survival and pathogenesis of the bacterium. A significant fraction of urease is associated with the surface of H. pylori both in vivo and in vitro. Surface-associated urease is essential for H. pylori to resist exposure to acid in the presence of urea. The mechanism whereby urease becomes associated with the surface of H. pylori is unique. This process, which we term "altruistic autolysis," involves release of urease (and other cytoplasmic proteins) by genetically programmed autolysis with subsequent adsorption of the released urease onto the surface of neighboring intact bacteria. To our knowledge, this is the first evidence of essential communal behavior in pathogenic bacteria; such behavior is crucial to understanding the pathogenesis of H. pylori.
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- 1998
7. Helicobacter pylori
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Dunn, B E, Cohen, H, and Blaser, M J
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Microbiology (medical) ,Helicobacter pylori ,General Immunology and Microbiology ,Epidemiology ,Vaccination ,Public Health, Environmental and Occupational Health ,Endoscopy ,Antibodies, Bacterial ,Polymerase Chain Reaction ,Anti-Bacterial Agents ,Helicobacter Infections ,Infectious Diseases ,Gastric Mucosa ,Genes, Bacterial ,Gastritis ,Bacterial Vaccines ,Disease Transmission, Infectious ,Humans ,Genome, Bacterial ,Research Article - Abstract
Helicobacter pylori is a gram-negative bacterium which causes chronic gastritis and plays important roles in peptic ulcer disease, gastric carcinoma, and gastric lymphoma. H. pylori has been found in the stomachs of humans in all parts of the world. In developing countries, 70 to 90% of the population carries H. pylori. In developed countries, the prevalence of infection is lower. There appears to be no substantial reservoir of H. pylori aside from the human stomach. Transmission can occur by iatrogenic, fecal-oral, and oral-oral routes. H. pylori is able to colonize and persist in a unique biological niche within the gastric lumen. All fresh isolates of H. pylori express significant urease activity, which appears essential to the survival and pathogenesis of the bacterium. A variety of tests to diagnose H. pylori infection are now available. Histological examination of gastric tissue, culture, rapid urease testing, DNA probes, and PCR analysis, when used to test gastric tissue, all require endoscopy. In contrast, breath tests, serology, gastric juice PCR, and urinary excretion of [15N]ammonia are noninvasive tests that do not require endoscopy. In this review, we highlight advances in the detection of the presence of the organism and methods of differentiating among types of H. pylori, and we provide a background for appropriate chemotherapy of the infection.
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- 1997
8. Review Contemporary Theory in Research in Visual Perception
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Dunn, B. E.
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- 1969
9. Review of Eye Movements and Vision
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Dunn, B. E.
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- 1969
10. Review of Foundations of Experimental Research
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Dunn, B. E.
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- 1969
11. Review of The Experimental Psychology of Sensory Behaviour
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Dunn, B. E.
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- 1969
12. Some geometric bases for perceived slant
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Dunn, B. E.
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- 1966
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13. Perceived slant as a function of direction of regard
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Dunn, B. E.
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- 1966
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14. Localization of Helicobacter pylori urease and heat shock protein in human gastric biopsies
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Dunn, B E, primary, Vakil, N B, additional, Schneider, B G, additional, Miller, M M, additional, Zitzer, J B, additional, Peutz, T, additional, and Phadnis, S H, additional
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- 1997
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15. Surface localization of Helicobacter pylori urease and a heat shock protein homolog requires bacterial autolysis
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Phadnis, S H, primary, Parlow, M H, additional, Levy, M, additional, Ilver, D, additional, Caulkins, C M, additional, Connors, J B, additional, and Dunn, B E, additional
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- 1996
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16. Correlation between serological and mucosal inflammatory responses to Helicobacter pylori
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Pérez-Pérez, G I, primary, Brown, W R, additional, Cover, T L, additional, Dunn, B E, additional, Cao, P, additional, and Blaser, M J, additional
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- 1994
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17. Identification of Ehrlichia chaffeensis morulae in cerebrospinal fluid mononuclear cells
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Dunn, B E, primary, Monson, T P, additional, Dumler, J S, additional, Morris, C C, additional, Westbrook, A B, additional, Duncan, J L, additional, Dawson, J E, additional, Sims, K G, additional, and Anderson, B E, additional
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- 1992
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18. Identification and purification of a cpn60 heat shock protein homolog from Helicobacter pylori
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Dunn, B E, primary, Roop, R M, additional, Sung, C C, additional, Sharma, S A, additional, Perez-Perez, G I, additional, and Blaser, M J, additional
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- 1992
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19. Purification and characterization of Helicobacter mustelae urease
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Dunn, B E, primary, Sung, C C, additional, Taylor, N S, additional, and Fox, J G, additional
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- 1991
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20. Lactoferrin and transferrin damage of the Gram-negative outer membrane is modulated by Ca2+ and Mg2+
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Ellison, R. T., primary, LaForce, F. M., additional, Giehl, T. J., additional, Boose, D. S., additional, and Dunn, B. E., additional
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- 1990
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21. Purification and characterization of urease from Helicobacter pylori.
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Dunn, B E, primary, Campbell, G P, additional, Perez-Perez, G I, additional, and Blaser, M J, additional
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- 1990
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22. Seroprevalence of Helicobacter pylori Infections in Thailand
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Perez-Perez, G. I., primary, Taylor, D. N., additional, Bodhidatta, L., additional, Wongsrichanalai, J., additional, Baze, W. B., additional, Dunn, B. E., additional, Echeverria, P. D., additional, and Blaser, M. J., additional
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- 1990
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23. Cardiovascular response patterns and speech: a study of air traffic controllers.
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Henderson, P R, primary, Bakal, D A, additional, and Dunn, B E, additional
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- 1990
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24. Protein changes occurring during storage of platelet concentrates.
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Snyder, E. L., Dunn, B. E., Giometti, C. S., Napychank, P. A., Tandon, N. N., Ferri, P. M., and Hofmann, J. P.
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- 1987
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25. The amnesic and therapeutic effects of bilateral and unilateral ECT.
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Costello, C. G., Belton, G. P., Abra, J. C., and Dunn, B. E.
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ELECTROCONVULSIVE therapy ,THERAPEUTICS ,MEMORY ,HOSPITAL wards - Abstract
The article investigates the amnesic and therapeutic effects of unilateral non-dominant, unilateral dominant, and bilateral electroconvulsive therapy (ECT) to verbal memory of patients in Alberta. To determine the effects, 30 in-patients receiving ECT of the Psychiatric Ward at the Foothills Hospital were used as subjects of the study. Some of the apparatuses used in the study are Lafayette Model 2303C memory drum, Marietta Model 15-10 memory drum, and electroshock device. The study revealed that the dominant hemisphere is more closely associated with recall and relearning verbal memory functioning. Furthermore, it showed the different effect between unilateral dominant and unilateral non-dominant ECT in recall.
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- 1970
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26. Helicobacter pylori containing only cytoplasmic urease is susceptible to acid.
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Krishnamurthy, P, Parlow, M, Zitzer, J B, Vakil, N B, Mobley, H L, Levy, M, Phadnis, S H, and Dunn, B E
- Abstract
Helicobacter pylori, an important etiologic agent in a variety of gastroduodenal diseases, produces large amounts of urease as an essential colonization factor. We have demonstrated previously that urease is located within the cytoplasm and on the surface of H. pylori both in vivo and in stationary-phase culture. The purpose of the present study was to assess the relative contributions of cytoplasmic and surface-localized urease to the ability of H. pylori to survive exposure to acid in the presence of urea. Toward this end, we compared the acid resistance in vitro of H. pylori cells which possessed only cytoplasmic urease to that of bacteria which possessed both cytoplasmic and surface-localized or extracellular urease. Bacteria with only cytoplasmic urease activity were generated by using freshly subcultured bacteria or by treating repeatedly subcultured H. pylori with flurofamide (1 microM), a potent, but poorly diffusible urease inhibitor. H. pylori with cytoplasmic and surface-located urease activity survived in an acid environment when 5 mM urea was present. In contrast, H. pylori with only cytoplasmic urease shows significantly reduced survival when exposed to acid in the presence of 5 mM urea. Similarly, Escherichia coli SE5000 expressing H. pylori urease and the Ni2+ transport protein NixA, which expresses cytoplasmic urease activity at levels similar to those in wild-type H. pylori, survived minimally when exposed to acid in the presence of 5 to 50 mM urea. We conclude that cytoplasmic urease activity alone is not sufficient (although cytoplasmic urease activity is likely to be necessary) to allow survival of H. pylori in acid; the activity of surface-localized urease is essential for resistance of H. pylori to acid under the assay conditions used. Therefore, the mechanism whereby urease becomes associated with the surface of H. pylori, which involves release of the enzyme from bacteria due to autolysis followed by adsorption of the enzyme to the surface of intact bacteria ("altruistic autolysis"), is essential for survival of H. pylori in an acid environment. The ability of H. pylori to survive exposure to low pH is likely to depend on a combination of both cytoplasmic and surface-associated urease activities.
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- 1998
27. Embryonic chick allantois: functional isolation and development of sodium transport
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Graves, J. S., Dunn, B. E., and Brown, S. C.
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By removing the shell membranes from the chorioallantoic membrane, the chorion is damaged, as visualized by electron microscopy, and rendered permeable, as evidenced by penetration of horseradish peroxidase and increased inhibition of the allantoic Na+-K+ pump by ouabain applied on the chorionic side. The short-circuit current (SCC) of this functionally isolated allantoic epithelium is augmented by nystatin, a channel-forming ionophore, when applied to the mucosal surface. Electrical parameters were determined for three age groups between 12 and 19 days of incubation. The SCC approximately doubled from the youngest (12-13 days) to the oldest (18-19 days) groups, whereas the transepithelial resistance (Re) of 700-900 omega X cm2 remained the same. Amiloride, an inhibitor of apical Na+ uptake, inhibited 98-100% of the SCC at 10(-4) M in both 15-16 and 18-19 day epithelia. In the 12- to 13-day preparation 20-25% of the SCC was insensitive to 10(-3) M amiloride. The Ki's for amiloride were similar in all preparations, at about 5 X 10(-7) M. Determination of the Hill coefficients for inhibition revealed a lower value (0.75 +/- 0.03) for the 12-13 day preparation compared with the two older preparations with coefficients not significantly different from unity. Replacing Na+ in the bathing solutions abolished the SCC of 18-19 day epithelia, whereas about 15% of the SCC remained at 12-13 days. Thus, during development, the SCC of the allantoic epithelium increases in magnitude and becomes increasingly (to 100%) amiloride-sensitive and Na+-dependent.
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- 1986
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28. Two-dimensional gel electrophoresis and immunoblotting of Campylobacter outer membrane proteins
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Dunn, B E, Blaser, M J, and Snyder, E L
- Abstract
We characterized outer membrane proteins (OMPs) from selected Campylobacter jejuni, C. coli, and C. fetus strains by two-dimensional gel electrophoresis (2DGE), using isoelectric focusing and sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE), and by immunoblotting with immune rabbit serum. The flagellar band with a molecular mass of 63 kilodaltons (kDa) demonstrated previously by one-dimensional SDS-PAGE was shown by 2DGE to consist of one or several charge trains, depending upon the species, strain, and type of preparation studied; each of the individual peptides was found to be antigenic by immunoblotting. In contrast, in all of the strains studied, the major OMP (43 to 44 kDa) of C.jejuni and C. coli consisted of a single isomeric form which was weakly immunogenic. Several minor proteins (29 to 31 kDa) were found to be strongly immunogenic by immunoblotting. C. fetus strains possessed two major OMPs of 45 to 47 kDa, each of which consisted of either a single isomer or a major isomer comprising at least 90% of the major OMP. Serum-resistant strains of C. fetus possessed an acid-labile 100-kDa glycoprotein (pI, 4.1) which was markedly diminished or absent in serum-sensitive strains. These 2DGE analyses provide information that is useful in taxonomic and epidemiologic studies and for the purification of surface antigens for the development of campylobacter vaccines and may also facilitate the identification of specific virulence factors.
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- 1987
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29. Two-dimensional gel electrophoresis and immunoblotting of Campylobacter pylori proteins
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Dunn, B E, Perez-Perez, G I, and Blaser, M J
- Abstract
Whole-cell, outer-membrane protein, flagellum-associated antigens and partially purified urease of Campylobacter pylori were analyzed by two-dimensional gel electrophoresis. C. pylori strains were readily distinguished from strains of Campylobacter jejuni, C. coli, and C. fetus by absence of major outer membrane proteins with Mrs of 41,000 to 45,000. C. pylori strains also lacked the acidic surface-array proteins at Mr 100,000 to 149,000 identified previously in serum-resistant strains of C. fetus. Surface labeling of intact C. pylori cells with 125I revealed two common major proteins, which we have designated protein 2 (pI 5.6 to 5.8, Mr 66,000) and protein 3 (pI 5.2 to 5.5, Mr 63,000). Proteins 2 and 3 were also the major components (subunits) observed in partially purified urease. Partially purified preparations of flagella consistently contained proteins 2 and 3. Thus, urease appears to be associated with both outer membranes and flagella of C. pylori. C. pylori strains also possessed an antigen at Mr 59,000 which was cross-reactive with antiserum against flagella of C. jejuni. However, the antigen did not appear to be associated with flagella per se in C. pylori. Protein 2 was unique to C. pylori among the Campylobacter species studied. It was not recognized by antibody against whole cells of C. jejuni or C. fetus or flagella of C. jejuni. Protein 3 was cross-reactive with antiserum against whole cells of C. jejuni and C. fetus, as were several other major protein antigens. Because protein 2 is a major outer membrane protein that is apparently unique to C. pylori, development of monospecific antibodies against this antigen may be useful for the identification of C. pylori in tissues, and purified antigen may be useful for serologic tests for specific diagnosis of C. pylori infections.
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- 1989
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30. Vibrio cholerae Wound Infection Acquired in Colorado
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Cover, T. L., primary, Dunn, B. E., additional, Ellison, R. T., additional, and Blaser, M. J., additional
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- 1989
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31. Two Fatal Cases of Adenovirus-Related Illness in Previously Healthy Young Adults--Illinois, 2000.
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Ryan, M. A. K., Gray, G. C., Malasig, M. D., Binn, L. N., Asher, L. V., Cute, D., Kehl, S. C., Dunn, B. E., and Yund, A. J.
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ADENOVIRUS diseases ,VIRAL vaccines ,VACCINES ,YOUNG adults ,DEATH - Abstract
Reports on two fatal cases related to adenovirus infection in two young adults at a military training base in Illinois. Background on adenoviruses; History of adenoviral vaccines given to young adults in military training; Details of the cases; Conclusions.
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- 2001
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32. Acute effects of prostaglandin E1 and E2 on vascular reactivity and blood flow in situ in the chick chorioallantoic membrane.
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Harland DR, Lorenz LD, Fay K, Dunn BE, Gruenloh SK, Narayanan J, Jacobs ER, and Medhora M
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- 15-Hydroxy-11 alpha,9 alpha-(epoxymethano)prosta-5,13-dienoic Acid pharmacology, Alprostadil antagonists & inhibitors, Animals, Biphenyl Compounds pharmacology, Blood Vessels drug effects, Blood Vessels physiology, Bridged Bicyclo Compounds, Heterocyclic, Chick Embryo, Chorioallantoic Membrane blood supply, Chorioallantoic Membrane metabolism, Dibenz(b,f)(1,4)oxazepine-10(11H)-carboxylic acid, 8-chloro-, 2-acetylhydrazide pharmacology, Dinoprostone antagonists & inhibitors, Dose-Response Relationship, Drug, Estradiol pharmacology, Estrogens pharmacology, Fatty Acids, Unsaturated, Hydrazines pharmacology, Microsomes drug effects, Microsomes metabolism, Misoprostol pharmacology, Prostaglandin Antagonists pharmacology, Rats, Receptors, Prostaglandin agonists, Receptors, Prostaglandin antagonists & inhibitors, Receptors, Prostaglandin metabolism, Receptors, Thromboxane agonists, Receptors, Thromboxane antagonists & inhibitors, Receptors, Thromboxane metabolism, Vasoconstriction drug effects, Vasoconstrictor Agents antagonists & inhibitors, Xanthones pharmacology, alpha-Linolenic Acid pharmacology, Alprostadil pharmacology, Chorioallantoic Membrane drug effects, Dinoprostone pharmacology, Vasoconstrictor Agents pharmacology
- Abstract
The chick chorioallantoic membrane (CAM) subserves gas exchange in the developing embryo and shell-less culture affords a unique opportunity for direct observations over time of individual blood vessels to pharmacologic interventions. We tested a number of lipids including prostaglandins PGE(1&2) for vascular effects and signaling in the CAM. Application of PGE(1&2) induced a decrease in the diameter of large blood vessels and a concentration-dependent, localized, reversible loss of blood flow through small vessels. The loss of flow was also mimicked by misoprostol, an agonist for 3 of 4 known PGE receptors, EP(2-4), and by U46619, a thromboxane mimetic. Selective receptor antagonists for EP(3) and thromboxane each partially blocked the response. This is a first report of the effects of prostaglandins on vasoreactivity in the CAM. Our model allows the unique ability to examine simultaneous responses of large and small vessels in real time and in vivo., (Copyright © 2012. Published by Elsevier Ltd.)
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- 2012
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33. Telepathology overview: from concept to implementation.
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Weinstein RS, Descour MR, Liang C, Bhattacharyya AK, Graham AR, Davis JR, Scott KM, Richter L, Krupinski EA, Szymus J, Kayser K, and Dunn BE
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- Diffusion of Innovation, Humans, Models, Theoretical, Remote Consultation methods, Telepathology methods, Remote Consultation organization & administration, Telepathology organization & administration
- Abstract
Telepathology is the practice of pathology at a distance by using video imaging and telecommunications. Significant progress has been made in telepathology. To date, 12 classes of telepathology systems have been engineered. Rapid and ultrarapid virtual slide processors may further expand the range of telepathology applications. Next-generation digital imaging light microscopes, such as miniaturized microscope arrays (MMA), may make virtual slide processing a routine laboratory tool. Diagnostic accuracy of telepathology is comparable with that of conventional light microscopy for most diagnoses. Current telepathology applications include intraoperative frozen sections services, routine surgical pathology services, second opinions, and subspecialty consultations. Three telepathology practice models are discussed: the subspecialty practice (SSP) model; the case triage practice (CTP) model; and the virtual group practice (VGP) model. Human factors influence performance with telepathology. Experience with 500 telepathology cases from multiple organs significantly reduces the video viewing time per case (P < .01). Many technology innovations can be represented as S-curves. After long incubation periods, technology use and/or efficiency may accelerate. Telepathology appears to be following an S-curve for a technical innovation., (Copyright 2001 by W.B. Saunders Company)
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- 2001
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34. Combined robotic and nonrobotic telepathology as an integral service component of a geographically dispersed laboratory network.
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Dunn BE, Choi H, Almagro UA, and Recla DL
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- Hospitals, Veterans organization & administration, Humans, Telepathology instrumentation, Telepathology methods, United States, United States Department of Veterans Affairs, Computer Communication Networks organization & administration, Remote Consultation, Robotics, Telepathology organization & administration
- Abstract
To achieve real-time connectivity between its 8 hopital-based laboratories, Veterans Integrated Service Network (VISN) 12, headquartered in Chicago, IL, has implemented a hybrid dynamic store-and-forward (HDSF) telepathology network that extends across portions of 3 states. The majority of diagnostic telepathology functions are provided to the 3 hospitals (Iron Mountain, MI; Tomah, WI; and North Chicago, IL), which lack on-site pathologists and are serviced by the 4 pathologists located in Milwaukee, WI. In surgical pathology, routine primary diagnosis, frozen section diagnosis, and clinical consultation are provided with telepathology. In addition, autopsy and specialty clinical conferences are frequently performed by using telepathology. Telepathology has been applied to a variety of areas within clinical pathology as well, including protein electrophoresis, immunoelectrophoresis, peripheral blood smears, body fluids, microbiology, and distance learning. Implementation of telepathology has allowed VISN 12 to reach the goal of providing a single standard of accurate and timely pathology service, even at small sites that lack an on-site pathologist., (Copyright 2001 by W.B. Saunders Company)
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- 2001
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35. Helicobacter pylori springs another surprise.
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Dunn BE and Grütter MG
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- Ammonia metabolism, Crystallography, X-Ray, Helicobacter pylori metabolism, Humans, Hydrogen-Ion Concentration, Peptic Ulcer microbiology, Protein Structure, Quaternary, Stomach microbiology, Urease ultrastructure, Gastric Acid metabolism, Helicobacter pylori enzymology, Urease chemistry, Urease metabolism
- Published
- 2001
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36. Telepathology networking in VISN-12 of the Veterans Health Administration.
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Dunn BE, Choi H, Almagro UA, Recla DL, and Davis CW
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- Humans, Illinois, United States, United States Department of Veterans Affairs, Wisconsin, Computer Communication Networks organization & administration, Hospitals, Veterans organization & administration, Telepathology organization & administration
- Abstract
The Veterans Integrated Service Network (VISN)-12, headquartered in Chicago, has implemented a telepathology network between the eight VISN-12 hospital laboratories and Loyola University Medical School linked by an economical, high-speed wide-area network (WAN). Implementation of the WAN has reduced monthly telecommunications costs in VISN-12 by approximately 67%. In addition to telepathology, the WAN enables real-time teleradiology (general, computer tomography, and ultrasound), telefluoroscopy, telenuclear medicine imaging, telepsychiatry, and other forms of teleconsultation. Current applications of telepathology in VISN-12 include: primary diagnosis and consultation in surgical pathology, interpretation of serum protein electrophoresis and immunofixation gels, provision of support for consolidated microbiology laboratories, review of problematic peripheral blood smears, and distance learning. We have learned a variety of lessons from telepathology. The enthusiasm and technical skill of providers are essential for success. As well, frequent communication and rapid technical support are necessary. Finally, in a supportive environment, telepathology is a tool that can help bring together clinical laboratories with shared missions and goals.
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- 2000
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37. Routine surgical telepathology in the Department of Veterans Affairs: experience-related improvements in pathologist performance in 2200 cases.
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Dunn BE, Choi H, Almagro UA, Recla DL, Krupinski EA, and Weinstein RS
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- Clinical Competence, Gastrointestinal Diseases pathology, Hospitals, Veterans standards, Humans, Male, Pathology Department, Hospital standards, Prostatic Diseases pathology, Reproducibility of Results, Skin Diseases pathology, Telepathology organization & administration, Time and Motion Studies, United States, Wisconsin, Hospitals, Veterans statistics & numerical data, Pathology Department, Hospital statistics & numerical data, Telepathology statistics & numerical data
- Abstract
Objective: To determine whether diagnostic concordance, case deferral rate, and/or time required to review slides changed significantly as telepathologists gained additional experience using a hybrid dynamic/store-and-forward (HDSF) telepathology (TP) system on the 2000 cases following an initial 200 consecutive surgical cases, previously reported., Materials and Methods: Gross surgical pathology specimens were prepared by specially trained personnel in Iron Mountain, Michigan. For TP, glass slides were placed on the stage of a robotic microscope at the Iron Mountain VAMC (remote site); control of the motorized microscope was then transferred to a pathologist located 220 miles away at the Milwaukee, Wisconsin, VAMC (host site). For each case, a telepathologist had the option of either rendering a diagnosis or deferring the case for later analysis by conventional light microscopy (LM). After the slides were read by TP and a surgical pathology report had been generated (for nondeferred cases), the slides were transported to Milwaukee, where they were reexamined by the same pathologist, now using LM. When there was disagreement between the TP and LM diagnosis, a supplemental or revised report was issued, and the referring physician was notified by telephone immediately. All supplemental and revised reports were reviewed by a third pathologist in the group. The slides were then reviewed by the pathology group practice or, when there was no consensus, by the Armed Forces Institute of Pathology to establish a "truth" diagnosis. To determine changes in telepathologist performance with experience after the initial start-up of the service, their performance in handling 10 consecutive sets of 200 surgical pathology cases was analyzed., Results: Concordance rates for clinically significant TP and LM diagnoses were high for all 10 sets, ranging from 99% to 100%. Comparing the first set (Cases 201-400) with the last set (Cases 2001-2200), viewing times per case were reduced from 10.26 min to 3. 58 min. Viewing times per slide were reduced from 3.44 min to 1.13 min per slide, comparing the first and last sets. Case turnaround times (TAT) decreased from 2.46 days to < or =1.5 days., Conclusion: Thes results demonstrate that improvements in TP services occur over time as the result of additional experience using the TP system. The high diagnostic concordance and low rate of case deferral lend additional support to the proposal that a host-site pathologist using HDSF TP can substitute effectively for an on-site pathologist as a service provider.
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- 1999
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38. Cost minimization analysis of telepathology.
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Agha Z, Weinstein RS, and Dunn BE
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- Costs and Cost Analysis, Equipment and Supplies economics, Humans, Medical Staff economics, Telepathology economics
- Abstract
Telepathology is gaining acceptance as a mode of providing pathology services to remote sites, but its economic feasibility is unknown. A dynamic robotic telepathology service between the Veterans Affairs Medical Center, Iron Mountain, MI, and the Veterans Affairs Medical Center, Milwaukee, WI, provides diagnostic services for routine and frozen section surgical pathology cases at Iron Mountain. We conducted a cost minimization analysis of this service by building a model to compare telepathology and on-site pathology in Iron Mountain and a courier method of transporting specimens from Iron Mountain to Milwaukee for diagnosis. Base case analysis showed the courier method to be the most economic; telepathology was less costly than on-site pathology. If the costs of telepathology equipment and telecommunication are lowered to reflect current cost, then telepathology becomes the favored option. Telepathology can be an economic mode of providing pathology services to a remote site.
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- 1999
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39. Identification of a novel penicillin-binding protein from Helicobacter pylori.
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Krishnamurthy P, Parlow MH, Schneider J, Burroughs S, Wickland C, Vakil NB, Dunn BE, and Phadnis SH
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- Amino Acid Sequence, Carrier Proteins isolation & purification, Genome, Bacterial, Helicobacter pylori chemistry, Helicobacter pylori metabolism, Isomerism, Molecular Sequence Data, Molecular Weight, Muramoylpentapeptide Carboxypeptidase isolation & purification, Penicillin-Binding Proteins, Penicillins pharmacology, Protein Binding drug effects, Bacterial Proteins, Carrier Proteins chemistry, Carrier Proteins genetics, Helicobacter pylori genetics, Hexosyltransferases, Muramoylpentapeptide Carboxypeptidase chemistry, Muramoylpentapeptide Carboxypeptidase genetics, Penicillins metabolism, Peptidyl Transferases
- Abstract
The Helicobacter pylori genome encodes four penicillin-binding proteins (PBPs). PBPs 1, 2, and 3 exhibit similarities to known PBPs. The sequence of PBP 4 is unique in that it displays a novel combination of two highly conserved PBP motifs and an absence of a third motif. Expression of PBP 4, but not PBP 1, 2, or 3, is significantly increased during mid- to late-log-phase growth.
- Published
- 1999
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40. Unsedated transnasal EGD: an alternative approach to conventional esophagogastroduodenoscopy for documenting Helicobacter pylori eradication.
- Author
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Saeian K, Townsend WF, Rochling FA, Bardan E, Dua K, Phadnis S, Dunn BE, Darnell K, and Shaker R
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- Adult, Aged, Breath Tests, Endoscopy, Digestive System economics, Helicobacter Infections drug therapy, Helicobacter Infections pathology, Humans, Male, Middle Aged, Patient Acceptance of Health Care, Pilot Projects, Urea analysis, Urease analysis, Endoscopy, Digestive System methods, Helicobacter Infections diagnosis, Helicobacter pylori
- Abstract
Background: The aim of this study was to assess the yield of antral biopsies performed via unsedated transnasal esophagogastroduodenoscopy, a technique that does not require conscious sedation with its concomitant costs and complications, for documentation of Helicobacter pylori eradication., Methods: Nineteen patients who were previously CLO test positive on conventional esophagogastroduodenoscopy and subsequently treated for H pylori infection were enrolled. The subjects had not received antibiotic therapy in the prior month and had no prior gastric surgery. By using a GIF-N30 fiberoptic endoscope and a tiny cup biopsy forceps (1.8 mm diameter), unsedated transnasal endoscopy was performed and antral biopsy specimens were taken for a CLO test, histologic analysis (Dieterle stain), and tissue culture. On the same day, the subjects underwent a carbon 13-labeled area urea breath test. All subjects completed a visual analog scale, rating the acceptability of the unsedated transnasal examination and the previous sedated conventional esophagogastroduodenoscopy., Results: There was no statistically significant difference between the results of the CLO tests (5/19 positive) versus the 13C-urea breath test (4/19 positive) (p = 0.96), the CLO tests versus histologic findings (5/19 positive) (p = 0.71), or the 13C-urea breath test versus histologic findings (p = 0.96). All tissue culture results were negative. The overall acceptability of unsedated transnasal esophagogastroduodenoscopy was similar to that of sedated conventional esophagogastroduodenoscopy., Conclusion: Unsedated transnasal esophagogastroduodenoscopy, a technique that eliminates the costs and complications associated with conscious sedation, is a feasible and accurate alternative to conventional esophagogastroduodenoscopy when documentation of H pylori eradication and confirmation of gastric ulcer healing are both indicated.
- Published
- 1999
- Full Text
- View/download PDF
41. Telemedicine.
- Author
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Dunn BE, Schapira RM, and Frahm J
- Subjects
- Humans, Michigan, Wisconsin, Telemedicine
- Published
- 1999
- Full Text
- View/download PDF
42. Telepathology.
- Author
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Almagro UA, Dunn BE, Choi H, and Recla DL
- Subjects
- Humans, Wisconsin, Telepathology organization & administration, Telepathology standards
- Published
- 1998
- Full Text
- View/download PDF
43. Telemicrobiology: feasibility study.
- Author
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McLaughlin WJ, Schifman RB, Ryan KJ, Manriquez GM, Bhattacharyya AK, Dunn BE, and Weinstein RS
- Subjects
- Arizona, Feasibility Studies, Female, Humans, Male, Microbiological Techniques, Microscopy, Retrospective Studies, Sensitivity and Specificity, Staining and Labeling, Bacterial Infections diagnosis, Gram-Negative Bacteria isolation & purification, Gram-Positive Bacteria isolation & purification, Remote Consultation methods
- Abstract
Background: Rural hospitals generally lack staffing with infectious disease specialists or pathologists. Without on-site pathologists, the range of microbiology services offered by clinical laboratories may be limited as well., Objective: To study the feasibility of using static-image telepathology to evaluate Gram stains of microbiologic preparations., Materials and Methods: In this retrospective feasibility study, three pathologists evaluated Gram stains of slides from 50 cases by two viewing modalities: static-image telepathology and conventional light microscopy. Digital video images of slides were captured at two magnifications (using 40x and 100x objective lenses) at 1024 x 768 x 24-bit color and transmitted over standard telephone lines at 14,400 kbps. Pathology reports and culture results served as "truth diagnoses." Categories of interpretations were correct, minor discrepancy, or major discrepancy with regard to the implications for patient care., Results: The diagnostic accuracy of video image readings and conventional light microscopy readings were nearly identical, with no statistically significant differences in the performances of specialty and nonspecialty pathologists (P > 0.05). The mean accuracies of readings of the video images and light microscopy images were 95.3% and 95.4%, respectively. Taking into account the time required by a referring pathologist to capture video digital images, telemicrobiology was somewhat less efficient than conventional light microscopy., Conclusions: Pathologists can accurately evaluate digital video images of preselected fields on Gram-stained slides. In clinical practice, however, a limiting factor may be the availability of local personnel qualified to select the microscopic fields for evaluation by telepathologists. The adequacy of the video images suggests that telepathology may also be used for remote supervision of quality assurance programs in microbiology laboratories, as well as for remote proficiency training of laboratory personnel.
- Published
- 1998
- Full Text
- View/download PDF
44. Genetic relatedness of Burkholderia (Pseudomonas) cepacia isolates from five cystic fibrosis centers in Michigan.
- Author
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Kumar A, Dietrich S, Schneider W, Jacobson R, Downes FP, Robinson-Dunn BE, Honicky R, Smith J, and Martin R
- Subjects
- Hospital Departments, Humans, Michigan, Restriction Mapping, Burkholderia cepacia genetics, Cross Infection microbiology, Cystic Fibrosis microbiology, DNA, Bacterial analysis
- Abstract
Burkholderia cepacia isolates from patients with cystic fibrosis (CF) attending five CF centers were studied for relatedness by cellular fatty acid methyl esters (FAME) and by chromosomal DNA restriction analysis. Twenty-eight of 32 (87.5%) isolates tested were grouped in cluster group 1 based on their FAME profiles. DNA analysis revealed that 29 of 32 (90.6%) B. cepacia isolates from five CF centers had one closely related DNA pattern. To examine strain variation over a time period, FAME profiles and DNA patterns of isolates from serial cultures on seven patients from center D were studied. For four patients, all serial B. cepacia isolates belonged to a single FAME cluster group; for the remaining three patients, all serial isolates belonged to any two of the four cluster groups. On serial culture isolates, a single DNA pattern (pattern A) was found in 31 of 32 isolates demonstrating a close genetic relatedness. These data corroborate the observations that the majority of patients colonised with B. cepacia in a CF center harbor strains genetically closely related as determined by FAME profiles and DNA patterns.
- Published
- 1997
- Full Text
- View/download PDF
45. Use of telepathology for routine surgical pathology review in a test bed in the Department of Veterans Affairs.
- Author
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Dunn BE, Almagro UA, Choi H, Recla DL, and Weinstein RS
- Subjects
- Humans, Observer Variation, Surgical Procedures, Operative, Biopsy, Remote Consultation, Telepathology
- Abstract
Background: Routine surgical pathology review by telepathology could be an important service component of multi-institutional pathology laboratory systems. Such service networks would increase access for rural hospitals without on-site pathologists to a broader range of pathology services on a daily basis., Methods: In this clinical trial, we analyzed the diagnostic accuracy, deferral rates, and viewing times of two generalist pathologists using a hybrid dynamic/store-and-forward (HDSF) telepathology (TP) system to render diagnoses in real time on 200 consecutive surgical cases. The objective was to assess the efficacy of TP in providing diagnostic surgical pathology services to a remote hospital without an onsite pathologist. Surgical pathology specimens underwent gross preparation by specially trained personnel. When appropriate, this was done under the video supervision of a telepathologist. For TP, glass slides were placed on the stage of a robotic microscope at the Iron Mountain (MI) Department of Veterans Affairs Medical Center (VAMC) (remote site); control of the motorized microscope was then transferred to a pathologist located 220 miles away at the Milwaukee VAMC (host site). For each case, the telepathologist had the option of rendering a diagnosis or deferring the case for later analysis by conventional light microscopy (LM). After the slides were read by TP and a surgical pathology report had been generated, the slides were transported to Milwaukee, where they were reexamined by the telepathologist using LM and then by the pathology group practice or, when there was no consensus, by an outside consultant to establish a "truth" diagnosis., Results: Compared with the consensus ("truth") diagnosis, clinically important and overall concordance were 99.0% and 97.4%, respectively, by TP, and clinically important and overall concordance were 100.0% and 98.5%, respectively, by LM. The deferral rate was 2.5%. Examining glass slides by HDSF telepathology took an average of 4.43 minutes per slide and 12.09 minutes per case., Conclusion: The high diagnostic accuracy and low rate of case deferral support the proposal that an offsite pathologist using HDSF telepathology can substitute effectively for an onsite pathologist as a service provider.
- Published
- 1997
- Full Text
- View/download PDF
46. Dynamic-robotic telepathology: Department of Veterans Affairs feasibility study.
- Author
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Dunn BE, Almagro UA, Choi H, Sheth NK, Arnold JS, Recla DL, Krupinski EA, Graham AR, and Weinstein RS
- Subjects
- Feasibility Studies, Humans, Reproducibility of Results, Retrospective Studies, United States, United States Department of Veterans Affairs, Robotics, Telepathology methods
- Abstract
In this retrospective study, we assess the accuracy, confidence levels, and viewing times of two generalist pathologists using both dynamic-robotic telepathology and conventional light microscopy (LM) to render diagnoses on a test set of 100 consecutive routine surgical pathology cases. The objective is to determine whether telepathology will allow a pathology group practice at a diagnostic hub to provide routine diagnostic services to a remote hospital without an on-site pathologist. For TP, glass slides were placed on the motorized stage of the robotic microscope of a telepathology system by a senior laboratory technologist in Iron Mountain, MI. Real-time control of the motorized microscope was then transferred to a pathologist in Milwaukee, WI, who viewed images of the glass slides on a video monitor. The telepathologists deferred rendering a diagnosis in 1.5% of cases. Clinically important concordance between the individual diagnoses rendered by telepathology and the "truth" diagnoses established by rereview of glass slides was 98.5%. In the telepathology mode, there were five incorrect diagnoses out of a total of 197 diagnoses. In four cases in which the telepathology diagnosis was incorrect, the pathologist's diagnosis by LM was identical to that rendered by telepathology. These represent errors of interpretation and cannot be ascribed to telepathology. The certainty of the pathologists with respect to their diagnoses was evaluated over time. Results for the first 50 cases served as baseline data. For the second 50 cases, confidence in rendering a diagnosis in the telepathology mode was essentially identical to that of making a diagnosis in the LM viewing mode. Viewing times in the telepathology mode also improved with more experience using the telepathology system. These results support the concept that an off-site pathologist using dynamic-robotic telepathology can substitute for an on-site pathologist as a service provider.
- Published
- 1997
- Full Text
- View/download PDF
47. Antimicrobial activity of calprotectin isolated from human empyema fluid supernatants.
- Author
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Santhanagopalan V, Hahn BL, Dunn BE, Weissner JH, and Sohnle PG
- Subjects
- Candida albicans drug effects, Exudates and Transudates chemistry, Humans, Leukocyte L1 Antigen Complex, Neural Cell Adhesion Molecules analysis, Neural Cell Adhesion Molecules drug effects, Neutrophils microbiology, Neutrophils pathology, Zinc pharmacology, Antifungal Agents isolation & purification, Empyema, Pleural metabolism, Neural Cell Adhesion Molecules isolation & purification
- Abstract
Abscess and empyema fluid supernatants have zinc-reversible antimicrobial activity that is thought to be due to calprotectin, a calcium- and zinc-binding protein present within neutrophil cytoplasm. The present studies were undertaken to determine if calprotectin isolated from human empyema fluid supernatants demonstrated similar antimicrobial activity to that of the original specimens. The characteristics of the calprotectin complex on SDS-PAGE and Western blotting with specific antisera were similar in neutrophil lysates and in empyema fluid supernatants. Ion-exchange and size-exclusion chromatography were used to obtain highly purified preparations of calprotectin from empyema fluids, and these preparations demonstrated zinc-reversible anti-Candida albicans activity which was similar to that observed in the original specimens. These findings suggest that calprotectin is responsible for most of the growth-inhibitory activity of empyema fluid supernatants against this organism.
- Published
- 1995
- Full Text
- View/download PDF
48. Correlation between serological and mucosal inflammatory responses to Helicobacter pylori.
- Author
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Pérez-Pérez GI, Brown WR, Cover TL, Dunn BE, Cao P, and Blaser MJ
- Subjects
- Antigens, Bacterial immunology, Bacterial Proteins immunology, Bacterial Toxins immunology, Biomarkers analysis, Chaperonin 60 immunology, Gastritis blood, Gastritis immunology, Gastritis pathology, Helicobacter Infections blood, Helicobacter Infections pathology, Humans, Middle Aged, Antibodies, Bacterial blood, Gastric Mucosa immunology, Gastric Mucosa pathology, Helicobacter Infections immunology, Helicobacter pylori immunology
- Abstract
In 82 patients who underwent gastroduodenoscopy, acute and chronic gastric mucosal inflammation was scored for severity, and systemic humoral immune responses to Helicobacter pylori antigens were assessed by enzyme-linked immunosorbent assays. On the basis of culture, gastric histology, and serologic evaluation, 33 patients were classified as H. pylori infected and 36 were classified as uninfected. Thirteen patients had negative cultures and stains but were seropositive and were analyzed separately from the other two groups. Specific serum immunoglobulin G (IgG) subclass responses to H. pylori whole-cell antigens and specific IgG responses to the 54-kDa heat shock protein homolog (Hp54K) and vacuolating cytotoxin were significantly greater in infected than in uninfected patients as were specific IgA responses to whole-cell antigens and cytotoxin (P < 0.001). Among the H. pylori-infected persons, serum IgG responses to Hp54K and to the vacuolating cytotoxin were correlated with acute mucosal inflammatory scores. In contrast, serum IgA responses to whole-cell sonicate and to vacuolating cytotoxin were inversely related to chronic inflammatory scores. By multivariant regression analysis, only specific serum IgG responses to Hp54K correlated with severity of inflammation (both acute and chronic; P < 0.001); these responses may be markers of inflammation or these antibodies could play a direct role in the pathogenesis of H. pylori-induced inflammation.
- Published
- 1994
- Full Text
- View/download PDF
49. Mitral restenosis and mitral regurgitation 1 year after Inoue mitral balloon valvotomy in a population of patients with pliable mitral valve stenosis.
- Author
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Ribeiro PA, Fawzy ME, Mimish L, Awad M, Dunn BE, Arafah MR, and Duran CG
- Subjects
- Adolescent, Adult, Catheterization instrumentation, Female, Follow-Up Studies, Heart Atria pathology, Heart Septum pathology, Humans, Iatrogenic Disease epidemiology, Incidence, Male, Middle Aged, Prospective Studies, Recurrence, Catheterization adverse effects, Mitral Valve Insufficiency etiology, Mitral Valve Stenosis therapy
- Abstract
To determine the rate of mitral restenosis and mitral regurgitation increase 1 year after mitral valvotomy using the Inoue balloon catheter, 66 consecutive patients with severe, pliable mitral stenosis had their mitral valve area (MVA) calculated by two-dimensional echocardiography (2DE) and Doppler before, immediately after balloon valvotomy, and at 1-year follow-up. Color Doppler studies were also done to detect small atrial septal defects (ASDs) and mitral regurgitation. The mean age of the patients was 31 +/- 12 years. Three patients were in New York Heart Association (NYHA) class II and 63 patients were in NYHA class III to IV. Sixty-two of the 66 patients had an echo score (Boston) of < or = 8. After Inoue balloon valvotomy (IBV), the MVA (2DE) increased from 0.8 +/- 0.2 to 1.9 +/- 0.3 cm2 (p < 0.001), and the Doppler MVA increased from 0.8 +/- 0.2 to 1.8 +/- 0.3 cm2 (p < 0.001). We detected 4 of 66 cases (6%) with significant residual mitral stenosis (MVA < 1.5 cm2). Mitral regurgitation increased in 14 of 66 patients (21%), but no patient developed severe mitral regurgitation. Fourteen out of 66 patients (20%) had ASDs that were detected on color Doppler. At 1-year follow-up the mean Doppler MVA was maintained at 1.8 +/- 0.4 cm2, with 6 of 66 patients (9%) exhibiting significant mitral valve restenosis. Residual significant mitral stenosis must be differentiated from mitral restenosis.(ABSTRACT TRUNCATED AT 250 WORDS)
- Published
- 1993
- Full Text
- View/download PDF
50. Pathogenic mechanisms of Helicobacter pylori.
- Author
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Dunn BE
- Subjects
- Bacterial Toxins biosynthesis, Gastrins blood, Gastritis microbiology, Helicobacter Infections blood, Helicobacter Infections immunology, Helicobacter pylori enzymology, Helicobacter pylori metabolism, Humans, Helicobacter Infections microbiology, Helicobacter pylori pathogenicity
- Abstract
There is general agreement that motility, urease activity, and association with gastric mucosal cells are important virulence factors of H. pylori. Urease activity is perhaps the best characterized of these factors. Presumably, urease activity creates a "cloud" of ammonia around the bacterium, thus neutralizing the lethal effects of gastric acid. Motility allows the bacterium to penetrate the mucus layer and promotes specific association of the bacteria with epithelial cells, further allowing evasion of gastric acidity. The association between gastrin levels and H. pylori infection is currently the most thoroughly studied feature relating to pathogenesis in vivo. Prolonged hypergastrinemia associated with H. pylori infection may contribute to increased parietal cell mass and chronically increased secretion of gastric acid; however, long-term studies are needed to validate this hypothesis. The identification of mucosal gamma delta T cells and immunologic cross-reactivity between H. pylori and gastric cells implies that the immune response contributes significantly to the pathogenesis of H. pylori. The role of the immune system in modulating H. pylori infection requires further study. Although many putative pathogenic factors have been identified on the basis of in vitro phenomena alone, their significance in vivo is not known. Ultimately, it will be necessary to evaluate the significance of these factors in animal models by using isogenic strains of H. pylori that differ only in a single genotypic characteristic.
- Published
- 1993
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