93 results on '"Boudreau L"'
Search Results
2. Radiation balance of wetland tundra at northern treeline estimated from remotely sensed data
- Author
-
Duguay, Claude R., Rouse, Wayne R., Lafleur, Peter M., and Boudreau, L. Dale
- Published
- 1999
3. Platelet microparticles in transfusion
- Author
-
Boudreau, L. H., Marcoux, G., and Boilard, E.
- Published
- 2015
- Full Text
- View/download PDF
4. Factors affecting the summer carbon dioxide budget of subarctic wetland tundra
- Author
-
Burton, Kimberley L., Rouse, Wayne R., and Boudreau, L. Dale
- Published
- 1996
5. Effect of microheterogeneity on bulk and surface properties of binary mixtures of polyoxyethene glycol monobutyl ethers with water
- Author
-
Smith, S., Wiseman, P., Boudreau, L., Marangoni, G., and Palepu, R.
- Published
- 1994
- Full Text
- View/download PDF
6. Hysteresis in Physical Sorption for MCM
- Author
-
Conner, W.C., primary, Springuel-Huet, M.A., additional, Fraissard, J., additional, Bonardet, J., additional, McMahon, T., additional, Boudreau, L., additional, and Masciadrelli, J., additional
- Published
- 1998
- Full Text
- View/download PDF
7. The role of individual terrain units in the water balance of wetland tundra
- Author
-
Boudreau, L. Dale and Rouse, Wayne R.
- Published
- 1995
8. What Factors are Necessary for the Induction of AA Amyloidosis? : (AA amyloid, glycosaminoglycans, amyloid enhancing factor, apo-SAA)
- Author
-
Kisilevsky, R., Snow, A. D., Subrahmanyan, L., Boudreau, L., Tan, R., Marrink, Jan, editor, and Van Rijswijk, Martin H., editor
- Published
- 1986
- Full Text
- View/download PDF
9. Ecological Risk Assessment of Open-Water Sediment Disposal to Support the Management of Freshwater Dredging Projects
- Author
-
Desrosiers, Mélanie, Martel, L., Triffault Bouchet, G., Michon, P., Boudreau, L., Lepage, S., Cormier, M., Thibodeau, S., Bélanger, C., Gagnon, C., Pelletier, M., Babut, Marc, Masson, S., ENVIRONNEMENT CANADA CAN, Partenaires IRSTEA, Institut national de recherche en sciences et technologies pour l'environnement et l'agriculture (IRSTEA)-Institut national de recherche en sciences et technologies pour l'environnement et l'agriculture (IRSTEA), Milieux aquatiques, écologie et pollutions (UR MALY), Institut national de recherche en sciences et technologies pour l'environnement et l'agriculture (IRSTEA), AQUARIUM DU QUEBEC CAN, Autres (partenariat avec la sphère publique (sans AO)), irstea, and Plan d'Action Saint-Laurent 2011-2026 (travail commencé dans le cadre du plan précédent)
- Subjects
RISQUE ENVIRONNEMENTAL ,SAINT LAURENT COURS D'EAU ,[SDE]Environmental Sciences - Abstract
Dredging activities can have a number of potential impacts, such as changes in the hydrological regime and adverse effects on wildlife habitats. Inappropriate management of contaminated sediments may also lead to significant environmental risk. Most dredging projects must therefore undergo an environmental assessment before they are carried out, in order to protect the environment and optimize sediment management. Depending on the degree of contamination, the current management framework includes the use of additional assessment tools to evaluate the ecological risk associated with contaminated sediments. Hence, the ecological risk assessment (ERA) approach presented in this document fine-tunes the analytical process surrounding the assessment of open-water disposal of dredged material and improves the decision-making process. The assessment must answer the following question: “In the context of a specific dredging project, is open-water disposal of dredged sediments acceptable?” This ERA approach was developed using an ecotoxicological study on the St. Lawrence River that collected and characterized samples in the natural environment and incorporated data from literature on the St. Lawrence River. In order to obtain a chemical, toxicological and biological characterization of the sediments, two sampling campaigns were carried out: the first in the fall of 2004 and the second in the fall of 2005. During selection of the sampling stations, areas of sedimentation (fluvial lakes, port areas, mouths of tributaries, etc.) were preferred, since these areas are recognized as having the highest contaminant levels due to the accumulation of fine particles. The ERA approach is composed of two tiers. Tier 1 describes the procedure for detecting the level of sediment contamination by comparing the results of the chemical analyses to the sediment quality assessment criteria established for Quebec. Tier 2, when required, describes the procedure for assessing the toxicity of freshwater sediments based on laboratory toxicity tests (mortality and growth of Hyalella azteca and Chironomus riparius). Depending on the results of the ERA, there are two possible management options: (1) the sediments can be disposed of in open water or can be used for other purposes, for example for beneficial uses such as the creation of wildlife habitats or beach replenishment, provided that the receiving environment is not thereby adversely affected; or (2) open-water disposal is prohibited and another management option must be chosen. This document presents the process by which the ERA approach was developed as well as rules for applying this approach.; Il est reconnu que les activités de dragage peuvent, entre autres, engendrer des modifications du régime hydrologique et avoir des effets négatifs sur les habitats fauniques. En présence de sédiments contaminés, une gestion inappropriée peut entraîner des risques significatifs pour l’environnement. La plupart des projets de dragage doivent par conséquent faire l’objet d’une évaluation environnementale avant leur réalisation afin d’assurer la protection de l’environnement et d’optimiser la gestion des sédiments. En fonction du degré de contamination, le cadre de gestion actuel prévoit le recours à des outils d’évaluation complémentaires pour juger du risque écotoxicologique associé aux sédiments contaminés. Ainsi, la démarche d’évaluation du risque écotoxicologique (ERE) qui a été élaborée permet d’affiner le cheminement de l’analyse concernant l’évaluation du rejet en eau libre des déblais de dragage et d’améliorer le processus de prise de décision. L’évaluation doit donner une réponse à la question suivante : « Dans le contexte d’un projet de dragage spécifique, est-il acceptable de rejeter les sédiments dragués en eau libre? » Cette démarche d’ERE a été établie à l’aide d’une étude écotoxicologique relative au fleuve Saint-Laurent comprenant la collecte et la caractérisation d’échantillons en milieu naturel, et utilisant des données de la littérature concernant le fleuve. Afin d’obtenir une caractérisation chimique, toxicologique et biologique des sédiments, deux campagnes d’échantillonnage ont été réalisées : la première à l’automne 2004 et la seconde à l’automne 2005. Lors de la sélection des stations d’échantillonnage, les zones de sédimentation (lacs fluviaux, zones portuaires, embouchures de tributaires, etc.) ont été favorisées, puisqu’il est reconnu que les plus fortes teneurs en contaminants sont associées à ces zones en raison de l’accumulation de particules fines qui s’y produit. La démarche d’ERE est constituée de deux étapes. L’étape 1 décrit la procédure de dépistage du niveau de contamination des sédiments en comparant les résultats des analyses chimiques aux critères d’évaluation de la qualité des sédiments établis pour le Québec. Lorsqu’elle est requise, l’étape 2 décrit la procédure d’évaluation de la toxicité des sédiments d’eau douce à partir d’essais de toxicité réalisés en laboratoire (mortalité et croissance de Hyalella azteca et Chironomus riparius). Selon les résultats de l’ERE, deux options de gestion sont possibles : 1) les sédiments peuvent être rejetés en eau libre ou être utilisés à d’autres fins, par exemple pour des usages bénéfiques tels que la création d’habitats fauniques ou le rechargement de plages, dans la mesure où le dépôt ne contribue pas à détériorer le milieu récepteur ou; 2) le dépôt en eau libre est proscrit et il faudra choisir une autre option de gestion. L’élaboration de la démarche d’ERE de même que ses règles d’application sont présentées dans le présent document.
- Published
- 2013
10. L’évaluation du risque écotoxicologique du rejet en eau libre des sédiments, en soutien à la gestion des projets de dragage en eau douce
- Author
-
Desrosiers, Mélanie, Martel, L., Triffault Bouchet, G., Michon, P., Boudreau, L., Lepage, S., Cormier, M., Thibodeau, S., Bélanger, C., Gagnon, C., Pelletier, M., Babut, Marc, Masson, S., ENVIRONNEMENT CANADA CAN, Partenaires IRSTEA, Institut national de recherche en sciences et technologies pour l'environnement et l'agriculture (IRSTEA)-Institut national de recherche en sciences et technologies pour l'environnement et l'agriculture (IRSTEA), Milieux aquatiques, écologie et pollutions (UR MALY), Institut national de recherche en sciences et technologies pour l'environnement et l'agriculture (IRSTEA), AQUARIUM DU QUEBEC CAN, Autres (partenariat avec la sphère publique (sans AO)), irstea, and Plan d'Action Saint-Laurent 2011-2026 (travail commencé dans le cadre du plan précédent)
- Subjects
RISQUE ENVIRONNEMENTAL ,SAINT LAURENT COURS D'EAU ,[SDE]Environmental Sciences - Abstract
Dredging activities can have a number of potential impacts, such as changes in the hydrological regime and adverse effects on wildlife habitats. Inappropriate management of contaminated sediments may also lead to significant environmental risk. Most dredging projects must therefore undergo an environmental assessment before they are carried out, in order to protect the environment and optimize sediment management. Depending on the degree of contamination, the current management framework includes the use of additional assessment tools to evaluate the ecological risk associated with contaminated sediments. Hence, the ecological risk assessment (ERA) approach presented in this document fine-tunes the analytical process surrounding the assessment of open-water disposal of dredged material and improves the decision-making process. The assessment must answer the following question: “In the context of a specific dredging project, is open-water disposal of dredged sediments acceptable?” This ERA approach was developed using an ecotoxicological study on the St. Lawrence River that collected and characterized samples in the natural environment and incorporated data from literature on the St. Lawrence River. In order to obtain a chemical, toxicological and biological characterization of the sediments, two sampling campaigns were carried out: the first in the fall of 2004 and the second in the fall of 2005. During selection of the sampling stations, areas of sedimentation (fluvial lakes, port areas, mouths of tributaries, etc.) were preferred, since these areas are recognized as having the highest contaminant levels due to the accumulation of fine particles. The ERA approach is composed of two tiers. Tier 1 describes the procedure for detecting the level of sediment contamination by comparing the results of the chemical analyses to the sediment quality assessment criteria established for Quebec. Tier 2, when required, describes the procedure for assessing the toxicity of freshwater sediments based on laboratory toxicity tests (mortality and growth of Hyalella azteca and Chironomus riparius). Depending on the results of the ERA, there are two possible management options: (1) the sediments can be disposed of in open water or can be used for other purposes, for example for beneficial uses such as the creation of wildlife habitats or beach replenishment, provided that the receiving environment is not thereby adversely affected; or (2) open-water disposal is prohibited and another management option must be chosen. This document presents the process by which the ERA approach was developed as well as rules for applying this approach.; Il est reconnu que les activités de dragage peuvent, entre autres, engendrer des modifications du régime hydrologique et avoir des effets négatifs sur les habitats fauniques. En présence de sédiments contaminés, une gestion inappropriée peut entraîner des risques significatifs pour l’environnement. La plupart des projets de dragage doivent par conséquent faire l’objet d’une évaluation environnementale avant leur réalisation afin d’assurer la protection de l’environnement et d’optimiser la gestion des sédiments. En fonction du degré de contamination, le cadre de gestion actuel prévoit le recours à des outils d’évaluation complémentaires pour juger du risque écotoxicologique associé aux sédiments contaminés. Ainsi, la démarche d’évaluation du risque écotoxicologique (ERE) qui a été élaborée permet d’affiner le cheminement de l’analyse concernant l’évaluation du rejet en eau libre des déblais de dragage et d’améliorer le processus de prise de décision. L’évaluation doit donner une réponse à la question suivante : « Dans le contexte d’un projet de dragage spécifique, est-il acceptable de rejeter les sédiments dragués en eau libre? » Cette démarche d’ERE a été établie à l’aide d’une étude écotoxicologique relative au fleuve Saint-Laurent comprenant la collecte et la caractérisation d’échantillons en milieu naturel, et utilisant des données de la littérature concernant le fleuve. Afin d’obtenir une caractérisation chimique, toxicologique et biologique des sédiments, deux campagnes d’échantillonnage ont été réalisées : la première à l’automne 2004 et la seconde à l’automne 2005. Lors de la sélection des stations d’échantillonnage, les zones de sédimentation (lacs fluviaux, zones portuaires, embouchures de tributaires, etc.) ont été favorisées, puisqu’il est reconnu que les plus fortes teneurs en contaminants sont associées à ces zones en raison de l’accumulation de particules fines qui s’y produit. La démarche d’ERE est constituée de deux étapes. L’étape 1 décrit la procédure de dépistage du niveau de contamination des sédiments en comparant les résultats des analyses chimiques aux critères d’évaluation de la qualité des sédiments établis pour le Québec. Lorsqu’elle est requise, l’étape 2 décrit la procédure d’évaluation de la toxicité des sédiments d’eau douce à partir d’essais de toxicité réalisés en laboratoire (mortalité et croissance de Hyalella azteca et Chironomus riparius). Selon les résultats de l’ERE, deux options de gestion sont possibles : 1) les sédiments peuvent être rejetés en eau libre ou être utilisés à d’autres fins, par exemple pour des usages bénéfiques tels que la création d’habitats fauniques ou le rechargement de plages, dans la mesure où le dépôt ne contribue pas à détériorer le milieu récepteur ou; 2) le dépôt en eau libre est proscrit et il faudra choisir une autre option de gestion. L’élaboration de la démarche d’ERE de même que ses règles d’application sont présentées dans le présent document.
- Published
- 2013
11. ALCOHOL-TREATED PTFE VASCULAR GRAFTS
- Author
-
Trudell, L. A., Boudreau, L., Van De Water, J. M., Jauregui, H., Richardson, P. D., and Galletti, P. M.
- Published
- 1978
12. Acute lymphangitis mimicking mechanical neck pain
- Author
-
Boudreau, L, primary
- Published
- 2001
- Full Text
- View/download PDF
13. Eddy covariance measurements of evaporation from Great Slave Lake, Northwest Territories, Canada
- Author
-
Blanken, Peter D., primary, Rouse, Wayne R., additional, Culf, Alistair D., additional, Spence, Chris, additional, Boudreau, L. Dale, additional, Jasper, Jesse N., additional, Kochtubajda, Bob, additional, Schertzer, William M., additional, Marsh, Philip, additional, and Verseghy, Diana, additional
- Published
- 2000
- Full Text
- View/download PDF
14. Comparing the performance of the Canadian land surface scheme @class) for two subarctic terrain types
- Author
-
Bellisario, Lianne M., primary, Boudreau, L. Dale, additional, Verseghy, Diana L., additional, Rouse, Wayne R., additional, and Blanken, Peter D., additional
- Published
- 2000
- Full Text
- View/download PDF
15. Deposition of oriented zeolite A films: in situ and secondary growth
- Author
-
Boudreau, L, primary
- Published
- 1999
- Full Text
- View/download PDF
16. Carbon dioxide fluxes in a northern fen during a hot, dry summer
- Author
-
Schreader, Cheryl P., primary, Rouse, Wayne R., additional, Griffis, Timothy J., additional, Boudreau, L. Dale, additional, and Blanken, P. D., additional
- Published
- 1998
- Full Text
- View/download PDF
17. Diel activity patterns of lake chubs and other fishes in a temperate stream
- Author
-
Reebs, S. G., primary, Boudreau, L., additional, Hardie, P., additional, and Cunjak, R. A., additional
- Published
- 1995
- Full Text
- View/download PDF
18. Radiation balance of wetland tundra of nothern treeline estimated from remotely sensed data.
- Author
-
Duguay, Claude R., Rouse, Wayne R., Lafleur, Peter M., and Boudreau, L. Dale
- Subjects
TUNDRA ecology ,REMOTE sensing ,RADIATION - Abstract
Traditional methods of measuring surface net radiation involve point measurements that represent only a small area surrounding the instrumented sites. Remotely sensed spaceborne data offer the means by which to obtain estimates of the outgoing fluxes at the regional scale. The objective of this study was to estimate surface albedo, surface thermal exitance, and net radiation using Landsat Thematic Mapper (TM) data over wetland tundra at northern treeline near Churchill, Manitoba, Canada. Ground-based measurements of each component of the radiation balance were acquired at 5 locations coincident with 2 TM overpasses during summer 1991. Each location was representative of 1 of the major terrain types found in the Hudson Bay Lowlands (i.e. sedge-dominated wetland, upland lichenheath, tundra lakes and ponds, willow/birch wetland, and open spruce-tamarack forest). The mean absolute differences between remote sensing estimates and field measurements (all sites combined) are 0.01 for albedo, 25.7 W m[sup -2] for thermal exitance, and 14.1 W m[sup -2] for net radiation. The 2 summer 1991 TM images (June and August) were then used to examine within and between terrain type variations in surface net radiation during the growing season. TM imagery from August 1984 and August 1991 were also utilised to investigate differences in surface fluxes between a dry year (1984) and a wet year (1991). Results indicate that surface wetness and, to a lesser extent, phenology are the 2 main factors controlling the radiation balance during the summer period in this subarctic tundra-forest landscape. [ABSTRACT FROM AUTHOR]
- Published
- 1999
- Full Text
- View/download PDF
19. Synthesis of ETS-4/TiO2 composite membranes and their pervaporation performance
- Author
-
Braunbarth, C. M., Boudreau, L. C., and Tsapatsis, M.
- Published
- 2000
- Full Text
- View/download PDF
20. ALCOHOLTREATED PTFE VASCULAR GRAFTS
- Author
-
Trudell, L. A., Boudreau, L., Water, J. M. Van De, Jauregui, H., Richardson, P. D., and Galletti, P. M.
- Published
- 1978
21. Direct evidence that natural killer cells in nonimmune spleen cell populations prevent tumor growth in vivo
- Author
-
Kasai, M, Leclerc, JC, McVay-Boudreau, L, Shen, FW, and Cantor, H
- Abstract
Relatively large numbers of nonimmune spleen cells do not protect against the local growth of two lymphomas. However, this heterogeneous population of splenic lymphocytes contains a subset of cells that efficiently protects against in vivo tumor growth. This cell population (cell-surface phenotype Thyl.2(-)Ig(-)Ly5.1(+)) represents less than 5 percent of the spleen cell population and is responsible for in vitro NK-mediated lysis. Although these studies clearly and directly demonstrate that Ly5(+) NK cells selected from a heterogeneous lymphoid population from nonimmune mice can protect syngeneic mice against local in vivo growth of two different types of tumor cells (in contrast to other lymphocyte sets within the spleen), they do not directly bear upon the role of NK cells in immunosurveillance. They do indicate that highly enriched Ig(-)Thyl(-)Ly5(+) cells, which account for virtually all in vitro NK activity, can retard tumor growth in vivo. It is difficult to ascribe all anti-tumor surveillance activity to NK cells, because they probably do not recirculate freely throughout the various organ systems of the body. Perhaps NK ceils may play a role in prevention of neoplastic growth within discrete anatomic compartments where there is rapid differentiation of stem cells to mature progeny (e.g., bone marrow, spleen, and portions of the gastrointestinal tract)and may normally act to regulate the growth and differentiation of non-neoplastic stem cells. Long-term observation of chimeric mice repopulated with bone marrow from congenic or mutant donors expressing very low or very high NK activity may help to answer these questions.
- Published
- 1979
- Full Text
- View/download PDF
22. Immunoregulatory circuits among T-cell sets. II. Physiologic role of feedback inhibition in vivo: absence in NZB mice.
- Author
-
Cantor, H, McVay-Boudreau, L, Hugenberger, J, Naidorf, K, Shen, F W, and Gershon, R K
- Abstract
We have shown that (a) purified T-helper cells induce cells of another T-cell set-, expressing the Ly123+Qa1+ surface phenotype, to exert potent suppressive activity, (b) this T-T interaction plays an important role in regulating in vivo immune responses, and (c) this interaction represents an important barrier to protocols intended to augment the immune status of individuals by adoptive (or active) immunotherapy. Our results also indicate that the Ly123+ T-cell set mediating feedback suppression in vivo is sensitive to both low doses of cyclophosphamide and removal of the thymus in adult life. The importance of this T-T interaction to normal, physiologic regulation of the immune system is emphasized by the finding that the major T-cell deficit of NZB mice (an inbred strain of mice that spontaneously develops an autoimmune disorder) is the absence or malfunction of an Ly123+ T-cell set responsible for feedback inhibition.
- Published
- 1978
- Full Text
- View/download PDF
23. Immunoregulatory circuits among T-cell sets. I. T-helper cells induce other T-cell sets to exert feedback inhibition.
- Author
-
Eardley, D D, Hugenberger, J, McVay-Boudreau, L, Shen, F W, Gershon, R K, and Cantor, H
- Abstract
These experiments test the hypothesis that cells carrying the Ly1+23- surface phenotype are programmed exclusively for helper and not suppressive activity regardless of external conditions such as the mode or type of antigen stimulation. To this end, we have stimulated purified populations of Ly1 cells with antigen in vitro using conditions devised to induce unselected T cells to express optimal levels of antigen specific T-suppressor activity. We find that after such stimulation, Ly1 cells generate SRBC-specific T-helper activity but not T-suppressive activity. These findings establish that the Ly1.2+,2.2/3.2- surface phenotype is a stable, and probably invariant, marker of T cells that are programmed to express only helper activity and have lost the capacity to directly suppress the antibody response. These findings support the concept that the genetic program for a single differentiated set of cells combines information for cell surface phenotype and function. We also demonstrate that antigen-stimulated Ly1 cells, in addition to inducing B cells to secrete antibody, can induce or activate other sets of resting T cells to develop profound suppressive effects. The surface phenotype of this feedback suppressive T-cell set is shown to be: Ly1+2+3+Qa1+. These findings, taken together, indicate that activation of resting Ly123 cells by immune Ly1 TH cells may represent an important homeostatic immunoregulatory mechanism.
- Published
- 1978
- Full Text
- View/download PDF
24. Antigen-specific T lymphocyte clones. III. Papain splits purified T suppressor molecules into two functional domains.
- Author
-
Fresno, M, McVay-Boudreau, L, and Cantor, H
- Abstract
Purified molecules (70,000 mol wt) from a T-suppressor (Ts) clone bind to sheep erythrocyte glycophorin and specifically suppress the response to this antigen. Papain splits purified 70,000-mol wt Ts molecules into two peptides: mol wt 45,000 and 24,000. The 45,000-mol wt peptide nonspecifically suppresses antibody response to several antigens and lacks antigen-binding activity. The 24,000-mol wt peptide does not suppress but retains antigen-binding activity. The results indicate that papain splits the Ts molecule into a "constant" region responsible for function and a "variable" region responsible for antigen-binding. Since binding of the 70,000-mol wt molecule to antigen also results in release of the 45,000 mol wt subunit, this cleavage may allow Ts molecules specific for one determinant to suppress immunity to complex foreign proteins.
- Published
- 1982
- Full Text
- View/download PDF
25. Antigen-specific T lymphocyte clones. I. Characterization of a T lymphocyte clone expressing antigen-specific suppressive activity.
- Author
-
Fresno, M, Nabel, G, McVay-Boudreau, L, Furthmayer, H, and Cantor, H
- Abstract
We have generated continuously propagatable T lymphocyte clones to study antigen-specific T cell functions. All Ly-2+ clones mediate suppressive activity and secrete a characteristic pattern of polypeptides that differs from Ly-2- T cell clones. Cells of one clone, Cl.Ly23/4, specifically bind glycophorin from sheep erythrocytes (SRBC). After incubation with [35S]methionine, supernate material from this clone also contains biosynthetically labeled 70,000-mol wt proteins that specifically bind to SRBC and this binding is inhibited by glycophorin from sheep but not other erythrocytes. These antigen-binding 70,000-mol wt peptides specifically and completely suppress primary anti-SRBC responses generated by mixtures of primed Ly-1+2- cells and B cells. Suppression by these antigen-binding peptides reflects direct inhibition of T-helper activity.
- Published
- 1981
- Full Text
- View/download PDF
26. Antigen-specific t lymphocyte clones. II. Purifcation and biological characterization of an antigen-specific suppressive protein synthesized by cloned T cells
- Author
-
Fresno, M, McVay-Boudreau, L, Nabel, G, and Cantor, H
- Abstract
We have generated an antigen-specific T suppressor clone that synthesizes 70,000-mol wt peptides that have antigen-specific-binding activity. Although these data also indicated that antigen-binding peptides completely inhibited the in vitro primary response to a complex antigen, suppression might reflect the combined biologic activities of many different 70-mol wt polypeptides or polypeptides associated with the 70,000-mol wt material by noncovalent interactions. The protein responsible for antigen-specific suppression was therefore purified to virtual homogeneity after sequential separation of internally labeled supernate peptides on Sephacryl S-200 and DEAE-cellulose columns followed by isoeleetrofocusing. The resulting protein is greater than 95 percent homogeneous according to sodium dodeeyl sulfate-polyacrylamide electrophoresis and represents two peptides having two very close but distinguishable isoelectric point values of approximately 5.0. The purified molecules are retained by columns coated with lentil lectin or antigen but not by columns coated with antisera specific for immunoglobulins, the I region of the major histocompatibility complex or Ly-1 or Ly-2 antigens. Less than 50 pg of the purified glycoprotein specifically and completely suppresses production of anti-sheep erythrocyte plaque-forming cell by mixtures of 10(6) Ly-1 cells and B cells and this is a result of inactivation of Ly-l-mediated helper function. Specific inactivation of T (Th) cells by the 70,000-mol wt molecule is rapid, specific, and requires the presence of antigen. The mechanism of specific suppression of Th function may depend upon two functionally distinct regions of the 70,000-mol wt molecule: one that binds antigen and a second that mediates suppression.
- Published
- 1981
- Full Text
- View/download PDF
27. Immunoregulatory circuits among T-cell sets. Identification of a subpopulation of T-helper cells that induces feedback inhibition.
- Author
-
Cantor, H, Hugenberger, J, McVay-Boudreau, L, Eardley, D D, Kemp, J, Shen, F W, and Gershon, R K
- Abstract
Purified Ly1 cells induce other T-cell sets to exert potent feedback inhibitory activity and this T-T interaction has been shown to play an important role in regulating in vivo immune responses. Approximately 2/3 of Ly1 cells also express the Qa1 surface phenotype (Ly1:Qa1+ cells). The experiments reported here indicate that Ly1:Qal+ cells are responsible for induction of feedback inhibition and that signals from both Ly1:Qal+ cells and Ly1:Qal- cells are required for optimal formation of antibody by B cells.
- Published
- 1978
- Full Text
- View/download PDF
28. A Highly Oriented Thin Film of Zeolite A
- Author
-
Boudreau, L. C. and Tsapatsis, M.
- Published
- 1997
29. Assembly of Alzheimer's amyloid-β fibrils and approaches for therapeutic intervention
- Author
-
Yang, D. -S, Serpell, L. C., Christopher Yip, Mclaurin, J., Chrishti, M. A., Horne, P., Boudreau, L., Kisilevsky, R., Westaway, D., and Fraser, P. E.
30. A reproducible model for the study of factor X kinetics in AA amyloidosis
- Author
-
Kisilevsky, R., primary, Giles, A., additional, Rae, G., additional, Hoogendoorn, H., additional, Brosseau, L., additional, Boudreau, L., additional, and Tan, R., additional
- Published
- 1988
- Full Text
- View/download PDF
31. A new high-resolution Fourier transform infrared spectrometer for ground-based atmospheric measurements in Toronto
- Author
-
Wiacek, A., primary, Yashcova, D., additional, Strong, K., additional, Boudreau, L., additional, Rochette, L., additional, and Roy, C., additional
- Full Text
- View/download PDF
32. A new high-resolution Fourier transform infrared spectrometer for ground-based atmospheric measurements in Toronto.
- Author
-
Wiacek, A., Yashcova, D., Strong, K., Boudreau, L., Rochette, L., and Roy, C.
- Published
- 2002
- Full Text
- View/download PDF
33. Assessing the impact of nursing education on skin and wound care.
- Author
-
Boudreau L, Maurer R, Reft J, Larson S, Hancock B, and Kleinpell R
- Published
- 2009
34. What's the skinny? A reduction in pressure ulcer prevalence in the surgical intensive care unit (SICU)
- Author
-
Browning M, Boudreau L, Franco L, Grenier J, Vainisi D, Herman E, Franker L, Ryan L, Sierrra M, and Fitzgerald R
- Published
- 2008
35. The role of individual terrain units in the water balance of wetlandtundra
- Author
-
Rouse, W. R. and Boudreau, L. D.
- Published
- 1995
36. Factors affecting the summer carbon dioxide budget of subarctic wetland tundra
- Author
-
Rouse, W. R., Boudreau, L. D., and Burton, K. L.
- Subjects
SOILS ,SUMMER ,SOIL moisture ,ECONOMIC seasonal variations ,CARBON dioxide - Published
- 1996
37. Greater TIMP-1 protein levels and neointimal formation represent sex-dependent cellular events limiting aortic vessel expansion in female rats.
- Author
-
Al-Katat A, Boudreau L, Gagnon E, Assous I, Villeneuve L, Leblanc CA, Bergeron A, Sirois M, El-Hamamsy I, and Calderone A
- Abstract
Fragmentation/loss of the structural protein elastin represents the precipitating event translating to aortic expansion and subsequent aneurysm formation. The present study tested the hypothesis that greater protein expression of tissue inhibitor of matrix metalloproteinase-1 (TIMP-1) and neointimal growth secondary to a reduction of medial elastin content represent sex-dependent events limiting aortic vessel expansion in females. TIMP-1 protein levels were higher in the ascending aorta of female versus male patients diagnosed with a bicuspid aortic valve (BAV). The latter paradigm was recapitulated in the aorta of adult male and female rats complemented by greater TIMP-2 expression in females. CaCl
2 (0.5 M) treatment of the infrarenal aorta of adult male and female rats increased the in situ vessel diameter and expansion was significantly smaller in females despite a comparable reduction of medial elastin content. The preferential appearance of a neointimal region of the CaCl2 -treated infrarenal aorta of female rats may explain in part the smaller in situ expansion and neointimal growth correlated positively with the % change of the in situ diameter. Neointimal formation was secondary to a significant increase in the density of medial/neointimal vascular smooth muscle cells (VSMCs) that re-entered the G2 -M phase whereas VSMC cell cycle re-entry was attenuated in the CaCl2 -treated infrarenal aorta of male rats. Thus, greater TIMP-1 expression in the aorta of female BAV patients may prevent excessive elastin fragmentation and preferential neointimal growth following CaCl2 -treatment of the infrarenal aorta of female rats represents a sex-dependent biological event limiting vessel expansion secondary to a significant loss of the structural protein., (© 2024 The Author(s). IUBMB Life published by Wiley Periodicals LLC on behalf of International Union of Biochemistry and Molecular Biology.)- Published
- 2024
- Full Text
- View/download PDF
38. Extended supercooled storage of red blood cells.
- Author
-
Isiksacan Z, William N, Senturk R, Boudreau L, Wooning C, Castellanos E, Isiksacan S, Yarmush ML, Acker JP, and Usta OB
- Subjects
- Humans, Cold Temperature, Antioxidants metabolism, Oxidative Stress, Cryopreservation methods, Time Factors, Erythrocytes cytology, Blood Preservation methods
- Abstract
Red blood cell (RBC) transfusions facilitate many life-saving acute and chronic interventions. Transfusions are enabled through the gold-standard hypothermic storage of RBCs. Today, the demand for RBC units is unfulfilled, partially due to the limited storage time, 6 weeks, in hypothermic storage. This time limit stems from high metabolism-driven storage lesions at +1-6 °C. A recent and promising alternative to hypothermic storage is the supercooled storage of RBCs at subzero temperatures, pioneered by our group. Here, we report on long-term supercooled storage of human RBCs at physiological hematocrit levels for up to 23 weeks. Specifically, we assess hypothermic RBC additive solutions for their ability to sustain supercooled storage. We find that a commercially formulated next-generation solution (Erythro-Sol 5) enables the best storage performance and can form the basis for further improvements to supercooled storage. Our analyses indicate that oxidative stress is a prominent time- and temperature-dependent injury during supercooled storage. Thus, we report on improved supercooled storage of RBCs at -5 °C by supplementing Erythro-Sol 5 with the exogenous antioxidants, resveratrol, serotonin, melatonin, and Trolox. Overall, this study shows the long-term preservation potential of supercooled storage of RBCs and establishes a foundation for further improvement toward clinical translation., (© 2024. The Author(s).)
- Published
- 2024
- Full Text
- View/download PDF
39. Venous invasion detectable only by elastic stain shows weak prognostic value in colon cancer.
- Author
-
Fei LYN, Patel SV, Popa T, Boudreau L, Caycedo-Marulanda A, Grin A, and Wang T
- Subjects
- Humans, Prognosis, Coloring Agents, Neoplasm Staging, Neoplasm Invasiveness pathology, Retrospective Studies, Colorectal Neoplasms pathology, Colonic Neoplasms diagnosis, Colonic Neoplasms pathology
- Abstract
Aims: Large venous invasion (VI) is prognostically significant in colon cancer. The increased use of elastic stains by pathologists results in higher VI detection rates compared to routine stains alone. This study assesses the prognostic value of VI detected by elastic versus routine stains., Methods and Results: Colon cancers resected between 2014 and 2017 underwent pathology slide review for VI. Cases without VI on routine stain were stained by elastic trichrome and re-examined. Demographic, clinical, pathological and outcome data were gathered by retrospective review. Kaplan-Meier curves with log-rank tests were performed for survival categorised by VI status. Cox regression was performed for multivariate analysis. Of 277 cases, 97 (35%) showed VI by routine stain alone, with an additional 58 (21%) discovered by subsequent elastic stains. Thus, elastic trichrome increased VI detection by 60%. However, only VI detected by routine stain showed worse overall survival (P < 0.001). VI detected by elastic stain only was not prognostically different from cases without VI (P = 0.428). For stage 2 cancers, VI was not prognostically significant regardless of method of detection. For stage 3 cases, only VI detected by routine stain was prognostic for overall survival (P = 0.002) with a hazard ratio of 4.04 by multivariate regression (P = 0.028)., Conclusions: VI detectable only by elastic stains do not show prognostic significance for survival in colon cancer. For pathologists with high baseline VI detections rates on routine stain, reflexive use of elastic stain may be of limited value., (© 2024 The Authors. Histopathology published by John Wiley & Sons Ltd.)
- Published
- 2024
- Full Text
- View/download PDF
40. 2023 Canadian Surgery Forum: Sept. 20-23, 2023.
- Author
-
Brière R, Émond M, Benhamed A, Blanchard PG, Drolet S, Habashi R, Golbon B, Shellenberger J, Pasternak J, Merchant S, Shellenberger J, La J, Sawhney M, Brogly S, Cadili L, Horkoff M, Ainslie S, Demetrick J, Chai B, Wiseman K, Hwang H, Alhumoud Z, Salem A, Lau R, Aw K, Nessim C, Gawad N, Alibhai K, Towaij C, Doan D, Raîche I, Valji R, Turner S, Balmes PN, Hwang H, Hameed SM, Tan JGK, Wijesuriya R, Tan JGK, Hew NLC, Wijesuriya R, Lund M, Hawel J, Gregor J, Leslie K, Lenet T, McIsaac D, Hallet J, Jerath A, Lalu M, Nicholls S, Presseau J, Tinmouth A, Verret M, Wherrett C, Fergusson D, Martel G, Sharma S, McKechnie T, Talwar G, Patel J, Heimann L, Doumouras A, Hong D, Eskicioglu C, Wang C, Guo M, Huang L, Sun S, Davis N, Wang J, Skulsky S, Sikora L, Raîche I, Son HJ, Gee D, Gomez D, Jung J, Selvam R, Seguin N, Zhang L, Lacaille-Ranger A, Sikora L, McIsaac D, Moloo H, Follett A, Holly, Organ M, Pace D, Balvardi S, Kaneva P, Semsar-Kazerooni K, Mueller C, Vassiliou M, Al Mahroos M, Fiore JF Jr, Schwartzman K, Feldman L, Guo M, Karimuddin A, Liu GP, Crump T, Sutherland J, Hickey K, Bonisteel EM, Umali J, Dogar I, Warden G, Boone D, Mathieson A, Hogan M, Pace D, Seguin N, Moloo H, Li Y, Best G, Leong R, Wiseman S, Alaoui AA, Hajjar R, Wassef E, Metellus DS, Dagbert F, Loungnarath R, Ratelle R, Schwenter F, Debroux É, Wassef R, Gagnon-Konamna M, Pomp A, Richard CS, Sebajang H, Alaoui AA, Hajjar R, Dagbert F, Loungnarath R, Sebajang H, Ratelle R, Schwenter F, Debroux É, Wassef R, Gagnon-Konamna M, Pomp A, Santos MM, Richard CS, Shi G, Leung R, Lim C, Knowles S, Parmar S, Wang C, Debru E, Mohamed F, Anakin M, Lee Y, Samarasinghe Y, Khamar J, Petrisor B, McKechnie T, Eskicioglu C, Yang I, Mughal HN, Bhugio M, Gok MA, Khan UA, Fernandes AR, Spence R, Porter G, Hoogerboord CM, Neumann K, Pillar M, Guo M, Manhas N, Melck A, Kazi T, McKechnie T, Jessani G, Heimann L, Lee Y, Hong D, Eskicioglu C, McKechnie T, Tessier L, Archer V, Park L, Cohen D, Parpia S, Bhandari M, Dionne J, Eskicioglu C, Bolin S, Afford R, Armstrong M, Karimuddin A, Leung R, Shi G, Lim C, Grant A, Van Koughnett JA, Knowles S, Clement E, Lange C, Roshan A, Karimuddin A, Scott T, Nadeau K, Macmillan J, Wilson J, Deschenes M, Nurullah A, Cahill C, Chen VH, Patterson KM, Wiseman SM, Wen B, Bhudial J, Barton A, Lie J, Park CM, Yang L, Gouskova N, Kim DH, Afford R, Bolin S, Morris-Janzen D, McLellan A, Karimuddin A, Archer V, Cloutier Z, Berg A, McKechnie T, Wiercioch W, Eskicioglu C, Labonté J, Bisson P, Bégin A, Cheng-Oviedo SG, Collin Y, Fernandes AR, Hossain I, Ellsmere J, El-Kefraoui C, Do U, Miller A, Kouyoumdjian A, Cui D, Khorasani E, Landry T, Amar-Zifkin A, Lee L, Feldman L, Fiore J, Au TM, Oppenheimer M, Logsetty S, AlShammari R, AlAbri M, Karimuddin A, Brown C, Raval MJ, Phang PT, Bird S, Baig Z, Abu-Omar N, Gill D, Suresh S, Ginther N, Karpinski M, Ghuman A, Malik PRA, Alibhai K, Zabolotniuk T, Raîche I, Gawad N, Mashal S, Boulanger N, Watt L, Razek T, Fata P, Grushka J, Wong EG, Hossain I, Landry M, Mackey S, Fairbridge N, Greene A, Borgoankar M, Kim C, DeCarvalho D, Pace D, Wigen R, Walser E, Davidson J, Dorward M, Muszynski L, Dann C, Seemann N, Lam J, Harding K, Lowik AJ, Guinard C, Wiseman S, Ma O, Mocanu V, Lin A, Karmali S, Bigam D, Harding K, Greaves G, Parker B, Nguyen V, Ahmed A, Yee B, Perren J, Norman M, Grey M, Perini R, Jowhari F, Bak A, Drung J, Allen L, Wiseman D, Moffat B, Lee JKH, McGuire C, Raîche I, Tudorache M, Gawad N, Park LJ, Borges FK, Nenshi R, Jacka M, Heels-Ansdell D, Simunovic M, Bogach J, Serrano PE, Thabane L, Devereaux PJ, Farooq S, Lester E, Kung J, Bradley N, Best G, Ahn S, Zhang L, Prince N, Cheng-Boivin O, Seguin N, Wang H, Quartermain L, Tan S, Shamess J, Simard M, Vigil H, Raîche I, Hanna M, Moloo H, Azam R, Ko G, Zhu M, Raveendran Y, Lam C, Tang J, Bajwa A, Englesakis M, Reel E, Cleland J, Snell L, Lorello G, Cil T, Ahn HS, Dube C, McIsaac D, Smith D, Leclerc A, Shamess J, Rostom A, Calo N, Thavorn K, Moloo H, Laplante S, Liu L, Khan N, Okrainec A, Ma O, Lin A, Mocanu V, Karmali S, Bigam D, Bruyninx G, Georgescu I, Khokhotva V, Talwar G, Sharma S, McKechnie T, Yang S, Khamar J, Hong D, Doumouras A, Eskicioglu C, Spoyalo K, Rebello TA, Chhipi-Shrestha G, Mayson K, Sadiq R, Hewage K, MacNeill A, Muncner S, Li MY, Mihajlovic I, Dykstra M, Snelgrove R, Wang H, Schweitzer C, Wiseman SM, Garcha I, Jogiat U, Baracos V, Turner SR, Eurich D, Filafilo H, Rouhi A, Bédard A, Bédard ELR, Patel YS, Alaichi JA, Agzarian J, Hanna WC, Patel YS, Alaichi JA, Provost E, Shayegan B, Adili A, Hanna WC, Mistry N, Gatti AA, Patel YS, Farrokhyar F, Xie F, Hanna WC, Sullivan KA, Farrokhyar F, Patel YS, Liberman M, Turner SR, Gonzalez AV, Nayak R, Yasufuku K, Hanna WC, Mistry N, Gatti AA, Patel YS, Cross S, Farrokhyar F, Xie F, Hanna WC, Haché PL, Galvaing G, Simard S, Grégoire J, Bussières J, Lacasse Y, Sassi S, Champagne C, Laliberté AS, Jeong JY, Jogiat U, Wilson H, Bédard A, Blakely P, Dang J, Sun W, Karmali S, Bédard ELR, Wong C, Hakim SY, Azizi S, El-Menyar A, Rizoli S, Al-Thani H, Fernandes AR, French D, Li C, Ellsmere J, Gossen S, French D, Bailey J, Tibbo P, Crocker C, Bondzi-Simpson A, Ribeiro T, Kidane B, Ko M, Coburn N, Kulkarni G, Hallet J, Ramzee AF, Afifi I, Alani M, El-Menyar A, Rizoli S, Al-Thani H, Chughtai T, Huo B, Manos D, Xu Z, Kontouli KM, Chun S, Fris J, Wallace AMR, French DG, Giffin C, Liberman M, Dayan G, Laliberté AS, Yasufuku K, Farivar A, Kidane B, Weessies C, Robinson M, Bednarek L, Buduhan G, Liu R, Tan L, Srinathan SK, Kidane B, Nasralla A, Safieddine N, Gazala S, Simone C, Ahmadi N, Hilzenrat R, Blitz M, Deen S, Humer M, Jugnauth A, Buduhan G, Kerr L, Sun S, Browne I, Patel Y, Hanna W, Loshusan B, Shamsil A, Naish MD, Qiabi M, Nayak R, Patel R, Malthaner R, Pooja P, Roberto R, Greg H, Daniel F, Huynh C, Sharma S, Vieira A, Jain F, Lee Y, Mousa-Doust D, Costa J, Mezei M, Chapman K, Briemberg H, Jack K, Grant K, Choi J, Yee J, McGuire AL, Abdul SA, Khazoom F, Aw K, Lau R, Gilbert S, Sundaresan S, Jones D, Seely AJE, Villeneuve PJ, Maziak DE, Pigeon CA, Frigault J, Drolet S, Roy ÈM, Bujold-Pitre K, Courval V, Tessier L, McKechnie T, Lee Y, Park L, Gangam N, Eskicioglu C, Cloutier Z, McKechnie T (McMaster University), Archer V, Park L, Lee J, Patel A, Hong D, Eskicioglu C, Ichhpuniani S, McKechnie T, Elder G, Chen A, Logie K, Doumouras A, Hong D, Benko R, Eskicioglu C, Castelo M, Paszat L, Hansen B, Scheer A, Faught N, Nguyen L, Baxter N, Sharma S, McKechnie T, Khamar J, Wu K, Eskicioglu C, McKechnie T, Khamar J, Lee Y, Tessier L, Passos E, Doumouras A, Hong D, Eskicioglu C, McKechnie T, Khamar J, Sachdeva A, Lee Y, Hong D, Eskicioglu C, Fei LYN, Caycedo A, Patel S, Popa T, Boudreau L, Grin A, Wang T, Lie J, Karimuddin A, Brown C, Phang T, Raval M, Ghuman A, Candy S, Nanda K, Li C, Snelgrove R, Dykstra M, Kroeker K, Wang H, Roy H, Helewa RM, Johnson G, Singh H, Hyun E, Moffatt D, Vergis A, Balmes P, Phang T, Guo M, Liu J, Roy H, Webber S, Shariff F, Helewa RM, Hochman D, Park J, Johnson G, Hyun E, Robitaille S, Wang A, Maalouf M, Alali N, Elhaj H, Liberman S, Charlebois P, Stein B, Feldman L, Fiore JF Jr, Lee L, Hu R, Lacaille-Ranger A, Ahn S, Tudorache M, Moloo H, Williams L, Raîche I, Musselman R, Lemke M, Allen L, Samarasinghe N, Vogt K, Brackstone M, Zwiep T, Clement E, Lange C, Alam A, Ghuman A, Karimuddin A, Phang T, Raval M, Brown C, Clement E, Liu J, Ghuman A, Karimuddin A, Phang T, Raval M, Brown C, Mughal HN, Gok MA, Khan UA, Mughal HN, Gok MA, Khan UA, Mughal HN, Gok MA, Khan UA, Mughal HN, Gok MA, Khan UA, James N, Zwiep T, Van Koughnett JA, Laczko D, McKechnie T, Yang S, Wu K, Sharma S, Lee Y, Park L, Doumouras A, Hong D, Parpia S, Bhandari M, Eskicioglu C, McKechnie T, Tessier L, Lee S, Kazi T, Sritharan P, Lee Y, Doumouras A, Hong D, Eskicioglu C, McKechnie T, Lee Y, Hong D, Dionne J, Doumouras A, Parpia S, Bhandari M, Eskicioglu C, Hershorn O, Ghuman A, Karimuddin A, Brown C, Raval M, Phang PT, Chen A, Boutros M, Caminsky N, Dumitra T, Faris-Sabboobeh S, Demian M, Rigas G, Monton O, Smith A, Moon J, Demian M, Garfinkle R, Vasilevsky CA, Rajabiyazdi F, Boutros M, Courage E, LeBlanc D, Benesch M, Hickey K, Hartwig K, Armstrong C, Engelbrecht R, Fagan M, Borgaonkar M, Pace D, Shanahan J, Moon J, Salama E, Wang A, Arsenault M, Leon N, Loiselle C, Rajabiyazdi F, Boutros M, Brennan K, Rai M, Farooq A, McClintock C, Kong W, Patel S, Boukhili N, Caminsky N, Faris-Sabboobeh S, Demian M, Boutros M, Paradis T, Robitaille S, Dumitra T, Liberman AS, Charlebois P, Stein B, Fiore JF Jr, Feldman LS, Lee L, Zwiep T, Abner D, Alam T, Beyer E, Evans M, Hill M, Johnston D, Lohnes K, Menard S, Pitcher N, Sair K, Smith B, Yarjau B, LeBlanc K, Samarasinghe N, Karimuddin AA, Brown CJ, Phang PT, Raval MJ, MacDonell K, Ghuman A, Harvey A, Phang PT, Karimuddin A, Brown CJ, Raval MJ, Ghuman A, Hershorn O, Ghuman A, Karimuddin A, Raval M, Phang PT, Brown C, Logie K, Mckechnie T, Lee Y, Hong D, Eskicioglu C, Matta M, Baker L, Hopkins J, Rochon R, Buie D, MacLean A, Ghuman A, Park J, Karimuddin AA, Phang PT, Raval MJ, Brown CJ, Farooq A, Ghuman A, Patel S, Macdonald H, Karimuddin A, Raval M, Phang PT, Brown C, Wiseman V, Brennan K, Patel S, Farooq A, Merchant S, Kong W, McClintock C, Booth C, Hann T, Ricci A, Patel S, Brennan K, Wiseman V, McClintock C, Kong W, Farooq A, Kakkar R, Hershorn O, Raval M, Phang PT, Karimuddin A, Ghuman A, Brown C, Wiseman V, Farooq A, Patel S, Hajjar R, Gonzalez E, Fragoso G, Oliero M, Alaoui AA, Rendos HV, Djediai S, Cuisiniere T, Laplante P, Gerkins C, Ajayi AS, Diop K, Taleb N, Thérien S, Schampaert F, Alratrout H, Dagbert F, Loungnarath R, Sebajang H, Schwenter F, Wassef R, Ratelle R, Debroux É, Cailhier JF, Routy B, Annabi B, Brereton NJB, Richard C, Santos MM, Gimon T, MacRae H, de Buck van Overstraeten A, Brar M, Chadi S, Kennedy E, Baker L, Hopkins J, Rochon R, Buie D, MacLean A, Park LJ, Archer V, McKechnie T, Lee Y, McIsaac D, Rashanov P, Eskicioglu C, Moloo H, Devereaux PJ, Alsayari R, McKechnie T, Ichhpuniani S, Lee Y, Eskicioglu C, Hajjar R, Oliero M, Fragoso G, Ajayi AS, Alaoui AA, Rendos HV, Calvé A, Cuisinière T, Gerkins C, Thérien S, Taleb N, Dagbert F, Sebajang H, Loungnarath R, Schwenter F, Ratelle R, Wassef R, Debroux E, Richard C, Santos MM, Kennedy E, Simunovic M, Schmocker S, Brown C, MacLean A, Liberman S, Drolet S, Neumann K, Stotland P, Jhaveri K, Kirsch R, Alnajem H, Alibrahim H, Giundi C, Chen A, Rigas G, Munir H, Safar A, Sabboobeh S, Holland J, Boutros M, Kennedy E, Richard C, Simunovic M, Schmocker S, Brown C, MacLean A, Liberman S, Drolet S, Neumann K, Stotland P, Jhaveri K, Kirsch R, Bruyninx G, Gill D, Alsayari R, McKechnie T, Lee Y, Hong D, Eskicioglu C, Zhang L, Abtahi S, Chhor A, Best G, Raîche I, Musselman R, Williams L, Moloo H, Caminsky NG, Moon JJ, Marinescu D, Pang A, Vasilevsky CA, Boutros M, Al-Abri M, Gee E, Karimuddin A, Phang PT, Brown C, Raval M, Ghuman A, Morena N, Ben-Zvi L, Hayman V, Hou M (University of Calgary), Nguyen D, Rentschler CA, Meguerditchian AN, Mir Z, Fei L, McKeown S, Dinchong R, Cofie N, Dalgarno N, Cheifetz R, Merchant S, Jaffer A, Cullinane C, Feeney G, Jalali A, Merrigan A, Baban C, Buckley J, Tormey S, Benesch M, Wu R, Takabe K, Benesch M, O'Brien S, Kazazian K, Abdalaty AH, Brezden C, Burkes R, Chen E, Govindarajan A, Jang R, Kennedy E, Lukovic J, Mesci A, Quereshy F, Swallow C, Chadi S, Habashi R, Pasternak J, Marini W, Zheng W, Murakami K, Ohashi P, Reedijk M, Hu R, Ivankovic V, Han L, Gresham L, Mallick R, Auer R, Ribeiro T, Bondzi-Simpson A, Coburn N, Hallet J, Cil T, Fontebasso A, Lee A, Bernard-Bedard E, Wong B, Li H, Grose E, Brandts-Longtin O, Aw K, Lau R, Abed A, Stevenson J, Sheikh R, Chen R, Johnson-Obaseki S, Nessim C, Hennessey RL, Meneghetti AT, Bildersheim M, Bouchard-Fortier A, Nelson G, Mack L, Ghasemi F, Naeini MM, Parsyan A, Kaur Y, Covelli A, Quereshy F, Elimova E, Panov E, Lukovic J, Brierley J, Burnett B, Swallow C, Eom A, Kirkwood D, Hodgson N, Doumouras A, Bogach J, Whelan T, Levine M, Parvez E, Ng D, Kazazian K, Lee K, Lu YQ, Kim DK, Magalhaes M, Grigor E, Arnaout A, Zhang J, Yee EK, Hallet J, Look Hong NJ, Nguyen L, Coburn N, Wright FC, Gandhi S, Jerzak KJ, Eisen A, Roberts A, Ben Lustig D, Quan ML, Phan T, Bouchard-Fortier A, Cao J, Bayley C, Watanabe A, Yao S, Prisman E, Groot G, Mitmaker E, Walker R, Wu J, Pasternak J, Lai CK, Eskander A, Wasserman J, Mercier F, Roth K, Gill S, Villamil C, Goldstein D, Munro V, Pathak A (University of Manitoba), Lee D, Nguyen A, Wiseman S, Rajendran L, Claasen M, Ivanics T, Selzner N, McGilvray I, Cattral M, Ghanekar A, Moulton CA, Reichman T, Shwaartz C, Metser U, Burkes R, Winter E, Gallinger S, Sapisochin G, Glinka J, Waugh E, Leslie K, Skaro A, Tang E, Glinka J, Charbonneau J, Brind'Amour A, Turgeon AF, O'Connor S, Couture T, Wang Y, Yoshino O, Driedger M, Beckman M, Vrochides D, Martinie J, Alabduljabbar A, Aali M, Lightfoot C, Gala-Lopez B, Labelle M, D'Aragon F, Collin Y, Hirpara D, Irish J, Rashid M, Martin T, Zhu A, McKnight L, Hunter A, Jayaraman S, Wei A, Coburn N, Wright F, Mallette K, Elnahas A, Alkhamesi N, Schlachta C, Hawel J, Tang E, Punnen S, Zhong J, Yang Y, Streith L, Yu J, Chung S, Kim P, Chartier-Plante S, Segedi M, Bleszynski M, White M, Tsang ME, Jayaraman S, Lam-Tin-Cheung K, Jayaraman S, Tsang M, Greene B, Pouramin P, Allen S, Evan Nelson D, Walsh M, Côté J, Rebolledo R, Borie M, Menaouar A, Landry C, Plasse M, Létourneau R, Dagenais M, Rong Z, Roy A, Beaudry-Simoneau E, Vandenbroucke-Menu F, Lapointe R, Ferraro P, Sarkissian S, Noiseux N, Turcotte S, Haddad Y, Bernard A, Lafortune C, Brassard N, Roy A, Perreault C, Mayer G, Marcinkiewicz M, Mbikay M, Chrétien M, Turcotte S, Waugh E, Sinclair L, Glinka J, Shin E, Engelage C, Tang E, Skaro A, Muaddi H, Flemming J, Hansen B, Dawson L, O'Kane G, Feld J, Sapisochin G, Zhu A, Jayaraman S, Cleary S, Hamel A, Pigeon CA, Marcoux C, Ngo TP, Deshaies I, Mansouri S, Amhis N, Léveillé M, Lawson C, Achard C, Ilkow C, Collin Y, Tai LH, Park L, Griffiths C, D'Souza D, Rodriguez F, McKechnie T, Serrano PE, Hennessey RL, Yang Y, Meneghetti AT, Panton ONM, Chiu CJ, Henao O, Netto FS, Mainprize M, Hennessey RL, Chiu CJ, Hennessey RL, Chiu CJ, Jatana S, Verhoeff K, Mocanu V, Jogiat U, Birch D, Karmali S, Switzer N, Hetherington A, Verhoeff K, Mocanu V, Birch D, Karmali S, Switzer N, Safar A, Al-Ghaithi N, Vourtzoumis P, Demyttenaere S, Court O, Andalib A, Wilson H, Verhoeff K, Dang J, Kung J, Switzer N, Birch D, Madsen K, Karmali S, Mocanu V, Wu T, He W, Vergis A, Hardy K, Zmudzinski M, Daenick F, Linton J, Zmudzinski M, Fowler-Woods M, He W, Fowler-Woods A, Shingoose G, Vergis A, Hardy K, Lee Y, Doumouras A, Molnar A, Nguyen F, Hong D, Schneider R, Fecso AB, Sharma P, Maeda A, Jackson T, Okrainec A, McLean C, Mocanu V, Birch D, Karmali S, Switzer N, MacVicar S, Dang J, Mocanu V, Verhoeff K, Jogiat U, Karmali S, Birch D, Switzer N, McLennan S, Verhoeff K, Purich K, Dang J, Kung J, Mocanu V, McLennan S, Verhoeff K, Mocanu V, Jogiat U, Birch DW, Karmali S, Switzer NJ, Jeffery L, Hwang H, Ryley A, Schellenberg M, Owattanapanich N, Emigh B, Nichols C, Dilday J, Ugarte C, Onogawa A, Matsushima K, Martin MJ, Inaba K, Schellenberg M, Emigh B, Nichols C, Dilday J, Ugarte C, Onogawa A, Shapiro D, Im D, Inaba K, Schellenberg M, Owattanapanich N, Ugarte C, Lam L, Martin MJ, Inaba K, Rezende-Neto J, Patel S, Zhang L, Mir Z, Lemke M, Leeper W, Allen L, Walser E, Vogt K, Ribeiro T, Bateni S, Bondzi-Simpson A, Coburn N, Hallet J, Barabash V, Barr A, Chan W, Hakim SY, El-Menyar A, Rizoli S, Al-Thani H, Mughal HN, Bhugio M, Gok MA, Khan UA, Warraich A, Gillman L, Ziesmann M, Momic J, Yassin N, Kim M, Makish A, Walser E, Smith S, Ball I, Moffat B, Parry N, Vogt K, Lee A, Kroeker J, Evans D, Fansia N, Notik C, Wong EG, Coyle G, Seben D, Smith J, Tanenbaum B, Freedman C, Nathens A, Fowler R, Patel P, Elrick T, Ewing M, Di Marco S, Razek T, Grushka J, Wong EG, Park LJ, Borges FK, Nenshi R, Serrano PE, Engels P, Vogt K, Di Sante E, Vincent J, Tsiplova K, Devereaux PJ, Talwar G, Dionne J, McKechnie T, Lee Y, Kazi T, El-Sayes A, Bogach J, Hong D, Eskicioglu C, Connell M, Klooster A, Beck J, Verhoeff K, Strickland M, Anantha R, Groszman L, Caminsky NG, Watt L, Boulanger N, Razek T, Grushka J, Di Marco S, Wong EG, Livergant R, McDonald B, Binda C, Luthra S, Ebert N, Falk R, and Joos E
- Published
- 2023
- Full Text
- View/download PDF
41. Demographic patterns of exposure and transmission for a rural Canadian community outbreak of COVID-19, 2020.
- Author
-
Patterson K, Chalifoux M, Gad R, Leblanc S, Paulsen P, Boudreau L, Mazerolle T, and Pâquet M
- Abstract
Background: A coronavirus disease 2019 (COVID-19) community outbreak was declared October 5-December 3, 2020, in the Restigouche region of New Brunswick, Canada. This article describes the epidemiological characteristics of the outbreak and assesses factors associated with its transmission in rural communities, informing public health measures and programming., Methods: A provincial line list was developed from case and contact interviews. Descriptive epidemiological methods were used to characterize the outbreak. Incidence rates among contacts, and by gender for the regional population were estimated., Results: There were 83 laboratory-confirmed cases of COVID-19 identified during the observation period. The case ages ranged from 10-89 years of age (median age group was 40-59 years of age) and 51.2% of the cases were male. Symptom onset dates ranged from September 27-October 27, 2020, with 83% of cases being symptomatic. A cluster of early cases at a social event led to multiple workplace outbreaks, though the majority of cases were linked to household transmission. Complex and overlapping social networks resulted in multiple exposure events and that obscured transmission pathways. The incidence rate among men was higher than women, men were significantly more likely to have transmission exposure at their workplace than women, and men were the most common index cases within a household. No transmission in school settings among children was documented despite multiple exposures., Conclusion: This investigation highlighted the gendered nature and complexity of a COVID-19 outbreak in a rural Canadian community. Targeted action at workplaces and strategic messaging towards men are likely required to increase awareness and adherence to public health measures to reduce transmission in these settings., Competing Interests: Competing interests None.
- Published
- 2022
42. Reducing Nares Acquired Pressure Injuries "Protect the Nares Because I Care" Project in Adult Inpatients: A Quality Improvement Project.
- Author
-
Sermersheim ER, Hall L, Boudreau L, Ambutas S, and Gulczynski B
- Subjects
- Adult, Humans, Incidence, Nose, Quality Improvement, Inpatients, Patient Care Bundles, Pressure Ulcer
- Abstract
Purpose: The purpose of this quality improvement (QI) project was to develop a preventive care bundle to reduce the incidence of nares acquired pressure injuries (NAPIs) to 3% in the adult inpatient population., Participants and Setting: Participants included adult inpatients in a large, Magnet-designated, 664-bed academic medical center in the Midwestern United States., Approach: Through our organization's "RUSH Way" QI model, we developed an evidence-based NAPI Bundle comprising a "T"-shaped hydrocolloid thin barrier, a tube holder securement device, patient assessments, and site checks. The project was initiated by a team of clinicians and administrators. An incidence report was conducted of hospital-wide existing NAPIs in 2015. A pilot QI project of the NAPI Bundle was implemented in the surgical intensive care unit (SICU) from January 2016 to May 2016 and then hospital-wide implementation began in June 2016. Data were collected on the incidence of NAPIs, and documentation of hydrocolloid dressing on the nose and intact, incidence of adverse events with hydrocolloid dressing, and hydrocolloid dressing changed every 3 days were evaluated., Results: In 2015, the house-wide baseline NAPI incidence rate was 4.9%. Data from the SICU pilot confirmed Bundle effectiveness, as zero NAPIs occurred during the pilot period. The hospital-wide expanded pilot in 2016 showed the NAPI rate to be 3.2%, and in 2017, the incidence rate was reduced to 1.4%, well below the 3% goal., Conclusion: The NAPI Bundle implemented in our organization by RNs substantially reduced the incidence of adult inpatient NAPIs., Competing Interests: The authors declare no conflicts of interest., (Copyright © 2021 by the Wound, Ostomy and Continence Nurses Society.)
- Published
- 2021
- Full Text
- View/download PDF
43. Union Efforts to Reduce COVID-19 Infections Among Grocery Store Workers.
- Author
-
Crowell NA, Hanson A, Boudreau L, Robbins R, and Sokas RK
- Subjects
- COVID-19 epidemiology, COVID-19 Vaccines, Female, Humans, Male, Occupations legislation & jurisprudence, Pandemics, SARS-CoV-2, Sick Leave legislation & jurisprudence, Vaccination statistics & numerical data, Ventilation legislation & jurisprudence, Ventilation standards, COVID-19 prevention & control, COVID-19 transmission, Labor Unions legislation & jurisprudence, Occupations statistics & numerical data, Safety legislation & jurisprudence, Supermarkets
- Abstract
Grocery store workers are essential workers, but often have not been provided with appropriate protection during the current pandemic. This report describes efforts made by one union local to protect workers, including negotiated paid sick leave and specific safety practices. Union representatives from 319 stores completed 1612 in-store surveys to assess compliance between 23 April 2020 and 31 August 2020. Employers provided the union with lists of workers confirmed to have COVID-19 infection through 31 December 2020. Worker infection rates were calculated using store employees represented by the union as the denominator and compared to cumulative county infection rates; outcome was dichotomized as rates higher or lower than background rates. Restrictions on reusable bags and management enforcement of customer mask usage were most strongly associated with COVID-19 rates lower than rates in the surrounding county. Stores that responded positively to worker complaints also had better outcomes. The union is currently engaging to promote improved ventilation and vaccination uptake.
- Published
- 2021
- Full Text
- View/download PDF
44. COVID-19 and Nurse-Sensitive Indicators: Using Performance Improvement Teams to Address Quality Indicators During a Pandemic.
- Author
-
Stifter J, Sermersheim E, Ellsworth M, Dowding E, Day E, Silvestri K, Margwarth J, Korkmaz K, Walkowiak N, Boudreau L, Hernandez L, Harbert B, Ambutas S, Abraham A, and Shaw P
- Subjects
- COVID-19 epidemiology, Humans, Pandemics, Quality Improvement standards, SARS-CoV-2, COVID-19 nursing, Nursing Staff, Hospital standards, Quality Improvement organization & administration, Quality Indicators, Health Care standards
- Abstract
Background: Nurse-sensitive quality indicators have historically been used as a metric of nursing care quality in health care organizations., Problem: At our academic medical center, critically ill COVID-19 patients led to a dramatic change in the organizational standard of care resulting in an increase in nurse-sensitive health care-associated infections., Approach: Nursing performance improvement teams provided the structure for development of innovative strategies implemented in real time by our frontline clinicians to address the quality and safety issues found with these elevated health care-associated infections., Outcomes: A new COVID-19 CLABSI (central line-associated bloodstream infection) Tip Sheet and a Prone Positioning Kit for HAPI Prevention are strategies developed to address quality of care issues experienced with the COVID-19 patients., Conclusions: Deployment of these innovative practice strategies has led to a decline in health care-associated infections and instituted a new care standard for the COVID-19 patients., Competing Interests: The authors declare no conflicts of interest., (Copyright © 2020 Wolters Kluwer Health, Inc. All rights reserved.)
- Published
- 2021
- Full Text
- View/download PDF
45. The changing boundaries of nursing: a qualitative study of the transition to a new nursing care delivery model.
- Author
-
Rhéaume A, Dionne S, Gaudet D, Allain M, Belliveau E, Boudreau L, and Brown L
- Subjects
- Adult, Female, Humans, Interviews as Topic, Male, Middle Aged, New Brunswick, Young Adult, Delivery of Health Care, Models, Nursing, Practice Patterns, Nurses'
- Abstract
Aims and Objectives: To explore how nursing personnel have experienced the introduction of a new nursing care delivery model within their setting., Background: New ways of nursing care are being implemented in many countries to contain rising health care costs and deal with ongoing nursing shortages. The adoption of new nursing care delivery models will have a substantial impact on the nature of nursing practice., Design: A qualitative design was used for this study. Symbolic interactionism was used as a guiding framework., Methods: Semi-structured interviews were held with 20 nurses (17 registered nurses and 3 ancillary nursing personnel) in two hospitals in eastern Canada following the introduction of a new nursing care nursing model. The constant comparative method was used to analyse interview data., Results: Four themes emerged from the data: (1) the ownership of tasks, (2) managing the workers, (3) a different way of knowing the patient and (4) the struggle to change., Conclusions: Nursing boundaries were flexible, regardless of the implementation of a new nursing care delivery model. Nursing tasks shifted from one group of workers to another during the course of the day to meet patient needs., Relevance to Clinical Practice: This study highlights the challenges in relation to the introduction of new nursing care delivery models within hospital settings., (© 2015 John Wiley & Sons Ltd.)
- Published
- 2015
- Full Text
- View/download PDF
46. Ideal body condition improves reproductive performance and influences genetic health in female mink.
- Author
-
Boudreau L, Benkel B, Astatkie T, and Rouvinen-Watt K
- Subjects
- Animals, Body Size, Breeding, Energy Metabolism, Female, Health, Reproduction, Seasons, Body Constitution physiology, Mink anatomy & histology, Mink physiology, Sexual Behavior, Animal physiology, Telomere Homeostasis
- Abstract
Selection for large body size in mink (Neovison vison) can result in obesity, which is associated with poor reproduction and metabolic disorders. Caloric restriction is effective in diminishing oxidative stress and delaying aging-related diseases. This study investigated the effects of moderate diet restriction on body condition, health, and reproductive success of mink breeder females. One-hundred control females were fed according to conventional feeding practice, while the feed allowance of their 100 sister-pair females was restricted in order to maintain an ideal body condition during the fall and eliminate the need for drastic slimming prior to breeding. Repeated measures analyses revealed that body weight gain during the fall and weight loss prior to breeding was significantly less for the restricted females. The restricted females had significantly larger live litters (5.88 kits) than the control dams (4.62 kits; P<0.05). They were also able to maintain their body weight and condition during early lactation and were able to regain weight and condition post-lactation, unlike their control sisters. Based on their comet scores (restricted: 88; control: 116), the restricted primiparous females experienced less DNA damage (P<0.05), while no significant differences were apparent for the multiparous females (restricted: 170; control: 153). No changes in telomere length were observed among the dams. Moderate diet restriction of mink breeder females during the fall eliminated extreme fluctuations in body weight and condition throughout the seasonal production cycle and improved their litter size, and in primiparous females, lessened DNA damage., (Copyright © 2014 Elsevier B.V. All rights reserved.)
- Published
- 2014
- Full Text
- View/download PDF
47. Vasectomy affects cysteine-rich secretory protein expression along the human epididymis and its association with ejaculated spermatozoa following vasectomy surgical reversal.
- Author
-
Légaré C, Boudreau L, Thimon V, Thabet M, and Sullivan R
- Subjects
- Adult, Ejaculation, Humans, Male, Middle Aged, Phosphorylation, Phosphotyrosine analysis, Semen chemistry, Sperm Capacitation, Epididymis metabolism, Membrane Glycoproteins chemistry, Membrane Glycoproteins metabolism, Spermatozoa chemistry, Vasectomy, Vasovasostomy
- Abstract
The epididymis is essential for the acquisition of sperm fertilizing ability and forward motility. After vasectomy, the flux and composition of the epididymal fluid are modified, causing possible sequelae to the occluded excurrent duct. Some of these sequelae may not be reversible following vasovasostomy, affecting sperm physiology and their fertilizing ability. We previously demonstrated that the epididymal expression in men of a major glycoprotein secreted by the epididymis, cysteine-rich secretory protein 1 (CRISP1), and its encoding mRNA are affected by vasectomy. In this study we showed that following vasectomy, the increased level of CRISP1 is not due to a secretory defect but to its accumulation in the intraluminal compartment of the cauda epididymidis. Western blot analyses were performed to determine the amount of CRISP1 associated with spermatozoa of men who had undergone surgical vasectomy reversal. Spermatozoa of vasovasostomized men are characterized by a significant increase (P < .05) in CRISP1 levels when compared with normal donors. There was no linear correlation between CRISP1 levels and the period of time elapsed between vasectomy and vasovasostomy. CRISP1 was also present in seminal plasma of normal and vasovasostomized men, but not in vasectomized individuals. The soluble concentration of CRISP1 was significantly higher (P < .05) in seminal plasma of vasovasostomized men when compared with normal men. Knowing that one of the proposed functions of CRISP1 is to modulate sperm capacitation, we evaluated the level of tyrosine protein phosphorylation of 2 AXAP proteins of the fibrous sheath, p81 and p105. Spermatozoa of vasovasostomized men were characterized by a 50% increase of protein tyrosine phosphorylation when compared to spermatozoa of normal men (P < .05). Our results are discussed with regard to the fertilizing ability of ejaculated spermatozoa of some vasovasostomized men.
- Published
- 2010
- Full Text
- View/download PDF
48. Short-chain aliphatic polysulfonates inhibit the entry of Plasmodium into red blood cells.
- Author
-
Kisilevsky R, Crandall I, Szarek WA, Bhat S, Tan C, Boudreau L, and Kain KC
- Subjects
- Alkanesulfonates pharmacology, Animals, Cells, Cultured, Chloroquine pharmacology, Erythrocytes drug effects, Erythrocytes enzymology, Female, L-Lactate Dehydrogenase blood, L-Lactate Dehydrogenase metabolism, Mice, Mice, Inbred BALB C, Plasmodium berghei drug effects, Plasmodium falciparum pathogenicity, Polyethylenes pharmacology, Structure-Activity Relationship, Antimalarials pharmacology, Erythrocytes parasitology, Plasmodium falciparum drug effects
- Abstract
Several steps in the pathogenesis of a Plasmodium falciparum infection depend on interactions of parasite surface proteins with negatively charged sugars on the surface of host cells such as sialate residues or glycosaminoglycans. For these reasons, our previous studies examining agents that interfere with heparan sulfate-protein binding during amyloidogenesis suggested that short-chain aliphatic polysulfonates may prove useful as antimalarial agents. A series of related polysulfonates were synthesized and assessed both in tissue culture with the asexual stages of P. falciparum in human red blood cells and in vivo by use of Plasmodium berghei infections in mice. Poly(vinylsulfonate sodium salt) (molecular weight range, 1,500 to 3,000) proved effective in interfering with P. falciparum merozoite entry into human red blood cells and significantly delaying the increase in the level of P. berghei parasitemia in mice. The concept that anionic molecules that mimic large polysaccharide structures may have antimalarial properties has been suggested and examined previously. Our results suggest that related anionic agents [poly(vinylsulfonate sodium salt)-like molecules] orders of magnitude smaller than those previously considered may prove useful in abrogating merozoite entry into erythrocytes and may potentially block sporozoite entry into liver cells. Structure-activity studies conducted to enhance these properties may provide compounds with scope for significant further analysis and development.
- Published
- 2002
- Full Text
- View/download PDF
49. Assembly of Alzheimer's amyloid-beta fibrils and approaches for therapeutic intervention.
- Author
-
Yang DS, Serpell LC, Yip CM, McLaurin J, Chrishti MA, Horne P, Boudreau L, Kisilevsky R, Westaway D, and Fraser PE
- Subjects
- Alzheimer Disease genetics, Amyloid beta-Peptides genetics, Animals, Disease Models, Animal, Hippocampus metabolism, Humans, Macromolecular Substances, Mice, Mice, Inbred C3H, Mice, Inbred C57BL, Mice, Transgenic, Microscopy, Atomic Force, Molecular Structure, Proteoglycans metabolism, X-Ray Diffraction, Alzheimer Disease metabolism, Alzheimer Disease therapy, Amyloid beta-Peptides chemistry, Amyloid beta-Peptides metabolism
- Abstract
Amyloid plaques are the principal features of Alzheimers disease (AD) pathology and are considered to be a major factor in the disease process. These fibrillar deposits are composed primarily of the 40-42 residue amyloid-beta (Abeta) peptide which is a proteolytic product of a larger membrane precursor protein. Electron microscopy and X-ray diffraction have revealed that the mature amyloid fibrils are assembled as a highly beta-sheet polymer that has a well-defined protofilament quaternary structure. This organization is observed for amyloid fibrils from a wide variety of disorders and appears to represent a structural superfamily. Amyloid plaques also contain a number of other components such as proteoglycans that contain highly sulfated glycosaminoglycan (GAG) chains. These amyloid-associated elements may contribute to the aggregation and/or stabilization of Abeta as insoluble fibrils. We have recently developed an aggressive model for Abeta plaque formation in transgenic mice that exhibits an "early-onset" phenotype. Immunocytochemistry has demonstrated that even with this rapid progression, Abeta deposits within the neuropil and cerebrovascular system all co-localize with heparan sulfate proteoglycans (HSPG). These findings indicate a number of structural features that can be targeted as potential sites for the development of amyloid inhibitors. In addition, the use of small compounds that interfere with the proteoglycan-amyloid pathway may be effective therapeutic agents that can be assessed through the use of these transgenic models.
- Published
- 2001
50. New clothes for amyloid enhancing factor (AEF): silk as AEF.
- Author
-
Kisilevsky R, Lemieux L, Boudreau L, Yang DS, and Fraser P
- Subjects
- Animals, Circular Dichroism, Female, Mice, Microscopy, Electron, Silk, Amyloid ultrastructure, Glycoproteins ultrastructure, Insect Proteins ultrastructure, Molecular Mimicry
- Abstract
Amyloid enhancing factor (AEF) is an activity that appears naturally during the course of persistent inflammation and precedes, by 24-48 h, AA amyloid deposition in appropriate murine models. AEF is defined by its biological properties, namely, when administered intravenously or intraperitoneally to a mouse, it primes the recipient for the rapid induction of AA amyloid when they are given an inflammatory stimulus. Available evidence indicates that AEF is protein in nature, but a specific molecular species (if a singular species exits) has not been identified. Past work (Ganowiak et al., Biochem. Biophys. Res. Commun. 199:306-312, 1994) has shown that AEF activity may be imparted to two different proteins (IAPP and beta-protein) provided each is organized in the form of an amyloid fibril. Since a characteristic property of proteins in amyloid fibrils is their beta-sheet organization, one possibility is that AEF activity, in part, depends on such organization, and other proteins with such properties may also have AEF activity. To investigate this possibility, silk, a protein which contains substantial beta-sheet content, was denatured in LiSCN and allowed to renature slowly under reducing conditions to form a gel. The denatured silk preparation was then sonicated thoroughly to permit intravenous injection and assessed for AEF activity. The modified silk, presented as small fibrils in a beta-sheet conformation as assessed by electron microscopy and circular dichroism, respectively. This silk at 0-50 micrograms/animal was administered intravenously as "AEF" followed immediately by subcutaneous AgNO3 as the inflammatory stimulus. Six days later the spleens were examined for the presence of AA amyloid and following Congo red staining, the amount of amyloid quantified by image analysis. Modified silk without an inflammatory stimulus, and non-sonicated modified silk, failed to induce AA amyloid. Sonicated modified silk followed by AgNO3 induced large quantities of splenic AA amyloid in a dose dependent fashion. Modified silk in quantities as small as 1-5 micrograms/animal can function as AEF. The AEF properties of the modified silk were stable at 4 degrees C for at least 4 weeks (the longest period tested). This procedure may provide a means of standardizing AEF preparations.
- Published
- 1999
- Full Text
- View/download PDF
Catalog
Discovery Service for Jio Institute Digital Library
For full access to our library's resources, please sign in.