Search

Your search keyword '"Kristoffersen K"' showing total 50 results
Start Over Author "Kristoffersen K" Search Limiters Full Text
50 results on '"Kristoffersen K"'

4. Reducing color flow artifacts caused by parallel beamforming

Author

Hergum, T., Bjastad, T.G., Lovstakken, L., Kristoffersen, K., and Torp, H.

Subjects
Beamforming -- Analysis, Color photography -- Evaluation, Doppler effect -- Analysis, Business, Electronics, Electronics and electrical industries
Published
2010

6. Monitoring meticillin resistant Staphylococcus aureus and its spread in Copenhagen, Denmark, 2013, through routine whole genome sequencing

Author

Bartels, M D, Larner-Svensson, H, Meiniche, H, Kristoffersen, K, Schonning, K, Nielsen, J B, Rohde, S M, Christensen, L B, Skibsted, A W, Jarlov, J O, Johansen, H K, Andersen, L P, Petersen, I S, Crook, D W, Bowden, R, Boye, K, Worning, P, Westh, H, Bartels, M D, Larner-Svensson, H, Meiniche, H, Kristoffersen, K, Schonning, K, Nielsen, J B, Rohde, S M, Christensen, L B, Skibsted, A W, Jarlov, J O, Johansen, H K, Andersen, L P, Petersen, I S, Crook, D W, Bowden, R, Boye, K, Worning, P, and Westh, H

Abstract

Typing of meticillin resistant Staphylococcus aureus (MRSA) by whole genome sequencing (WGS) is performed routinely in Copenhagen since January 2013. We describe the relatedness, based on WGS data and epidemiological data, of 341 MRSA isolates. These comprised all MRSA (n = 300) identified in Copenhagen in the first five months of 2013. Moreover, because MRSA of staphylococcal protein A (spa)-type 304 (t304), sequence type (ST) 6 had been associated with a continuous neonatal ward outbreak in Copenhagen starting in 2011, 41 t304 isolates collected in the city between 2010 and 2012 were also included. Isolates from 2013 found to be of t304, ST6 (n=14) were compared to the 41 earlier isolates. In the study, isolates of clonal complex (CC) 22 were examined in detail, as this CC has been shown to include the hospitalacquired epidemic MRSA (EMRSA-15) clone. Finally, all MRSA ST80 were also further analysed, as representatives of an important community-acquired MRSA in Europe. Overall the analysis identified 85 spa-types and 35 STs from 17 CCs. WGS confirmed the relatedness of epidemiologically linked t304 neonatal outbreak isolates. Several non-outbreak related patients had isolates closely related to the neonatal isolates suggesting unrecognised community chains of transmission and insufficient epidemiological data. Only four CC22 isolates were related to EMRSA-15. No community spread was observed among the 13 ST80 isolates. WGS successfully replaced conventional typing and added information to epidemiological surveillance. Creation of a MRSA database allows clustering of isolates based on single nucleotide polymorphism (SNP) calling and has improved our understanding of MRSA transmission., Typing of meticillin resistant Staphylococcus aureus (MRSA) by whole genome sequencing (WGS) is performed routinely in Copenhagen since January 2013. We describe the relatedness, based on WGS data and epidemiological data, of 341 MRSA isolates. These comprised all MRSA (n = 300) identified in Copenhagen in the first five months of 2013. Moreover, because MRSA of staphylococcal protein A (spa)-type 304 (t304), sequence type (ST) 6 had been associated with a continuous neonatal ward outbreak in Copenhagen starting in 2011, 41 t304 isolates collected in the city between 2010 and 2012 were also included. Isolates from 2013 found to be of t304, ST6 (n=14) were compared to the 41 earlier isolates. In the study, isolates of clonal complex (CC) 22 were examined in detail, as this CC has been shown to include the hospital-acquired epidemic MRSA (EMRSA-15) clone. Finally, all MRSA ST80 were also further analysed, as representatives of an important community-acquired MRSA in Europe. Overall the analysis identified 85 spa-types and 35 STs from 17 CCs. WGS confirmed the relatedness of epidemiologically linked t304 neonatal outbreak isolates. Several non-outbreak related patients had isolates closely related to the neonatal isolates suggesting unrecognised community chains of transmission and insufficient epidemiological data. Only four CC22 isolates were related to EMRSA-15. No community spread was observed among the 13 ST80 isolates. WGS successfully replaced conventional typing and added information to epidemiological surveillance. Creation of a MRSA database allows clustering of isolates based on single nucleotide polymorphism (SNP) calling and has improved our understanding of MRSA transmission.

Published
2015

7. Monitoring meticillin resistant Staphylococcus aureus and its spread in Copenhagen, Denmark, 2013, through routine whole genome sequencing

Author

Bartels, M D, primary, Larner-Svensson, H, additional, Meiniche, H, additional, Kristoffersen, K, additional, Schønning, K, additional, Nielsen, J B, additional, Rohde, S M, additional, Christensen, L B, additional, Skibsted, A W, additional, Jarløv, J O, additional, Johansen, H K, additional, Andersen, L P, additional, Petersen, I S, additional, Crook, D W, additional, Bowden, R, additional, Boye, K, additional, Worning, P, additional, and Westh, H, additional

Published
2015
Full Text
View/download PDF

8. Practical Verification of Embedded Software

Author

Staunstrup, J., Larsen, Kim Guldstrand, Andersen, H. R., Hulgaard, H., Behrmann, Gerd, Kristoffersen, K., Lind-Nielsen, J., Leerberg, H., Skou, Arne, and Theilgaard, N. B.

Subjects
METIS-118702
Published
2000

9. Rise and subsequent decline of community-associated methicillin resistant Staphylococcus aureus ST30-IVc in Copenhagen, Denmark through an effective search and destroy policy

Author

Bartels, M D, Kristoffersen, K, Boye, K, Westh, H, Bartels, M D, Kristoffersen, K, Boye, K, and Westh, H

Abstract

Udgivelsesdato: 2010-Jan, The number of patients with community-associated methicillin-resistant Staphylococcus aureus (CA-MRSA) has increased rapidly in Copenhagen, Denmark since 2003. Patients with the typical Panton-Valentine leukocidin-positive CA-MRSA clone ST30-IVc were contacted with the aim of treating MRSA carriers, evaluating the effect of MRSA eradication therapy (ET), and finding links among patients. Twenty-three index patients infected with the ST30-IVc clone from November 2003 to September 2005 were contacted and transmission chains were studied. The majority of ST30-IVc patients had a connection to the Philippines. Household members were screened for MRSA and all members of families with MRSA carriers were offered treatment of the carrier state and were followed for 1 year. MRSA carriers were found in seven of 16 households and transmission occurred among close contacts and in kindergartens. Five days of ET was insufficient and at least one person in each household was treated with systemic antibiotics. All families were MRSA negative at 1-year follow-up. The CA-MRSA clone ST30-IVc has been imported to Copenhagen, Denmark, primarily from the Philippines, and has spread through close contacts and in kindergartens. Treatment of MRSA carriers was difficult and required many resources, but the clone was eventually successfully eliminated. The import of ST30-IVc to Denmark will continue, but the spread of the clone in Denmark can be kept to a minimum by direct intervention in the affected families.

Published
2010

11. Environmental meticillin-resistant Staphylococcus aureus (MRSA) disinfection using dry-mist-generated hydrogen peroxide

Author

Bartels, M.D., Kristoffersen, K., Slotsbjerg, T., Rohde, S.M., Lundgren, B., Westh, H., Bartels, M.D., Kristoffersen, K., Slotsbjerg, T., Rohde, S.M., Lundgren, B., and Westh, H.

Abstract

Meticillin-resistant Staphylococcus aureus (MRSA) is a major problem in hospitals worldwide. Hand hygiene is recognised as crucial in limiting the spread of MRSA but less is known about the role of MRSA reservoirs in the inanimate hospital environment. We evaluated the effect of hydrogen peroxide vapour diffused by Sterinis((R)) against MRSA in two experimental hospital settings and in two field trials. Dipslides were used for MRSA detection and quantification before and after using the Sterinis disinfection process. In the first experimental hospital setting, four epidemic MRSA strains were placed at five locations and left for one week. All strains survived the week but not the disinfection process. In field trial one 14 upholstered chairs from a department with many MRSA positive patients were left for one month in a closed room prior to disinfection. MRSA was found on the upholstery of four of the 14 chairs. Three chairs became MRSA negative immediately after the disinfection, the fourth 24h later. The second field trial was in the private home of a MRSA positive family of four individuals. One location was found MRSA positive, remaining so after the Sterinis cycles. We found Sterinis to be effective against MRSA in the experimental hospital setting and upholstered chairs, but not in the private home of heavily colonised MRSA patients Udgivelsesdato: 2008/9

Published
2008

12. CELL BIOLOGY AND SIGNALING

Author

Agarwal, M., primary, Nitta, R., additional, Dovat, S., additional, Li, G., additional, Arita, H., additional, Narita, Y., additional, Fukushima, S., additional, Tateishi, K., additional, Matsushita, Y., additional, Yoshida, A., additional, Miyakita, Y., additional, Ohno, M., additional, Collins, V. P., additional, Kawahara, N., additional, Shibui, S., additional, Ichimura, K., additional, Kahn, S. A., additional, Gholamin, S., additional, Junier, M.-P., additional, Chneiweiss, H., additional, Weissman, I., additional, Mitra, S., additional, Cheshier, S., additional, Avril, T., additional, Hamlat, A., additional, Le Reste, P.-J., additional, Mosser, J., additional, Quillien, V., additional, Carrato, C., additional, Munoz-Marmol, A., additional, Serrano, L., additional, Pijuan, L., additional, Hostalot, C., additional, Villa, S. l., additional, Ariza, A., additional, Etxaniz, O., additional, Balana, C., additional, Benveniste, E. T., additional, Zheng, Y., additional, McFarland, B., additional, Drygin, D., additional, Bellis, S., additional, Bredel, M., additional, Lotsch, D., additional, Engelmaier, C., additional, Allerstorfer, S., additional, Grusch, M., additional, Pichler, J., additional, Weis, S., additional, Hainfellner, J., additional, Marosi, C., additional, Spiegl-Kreinecker, S., additional, Berger, W., additional, Bronisz, A., additional, Nowicki, M. O., additional, Wang, Y., additional, Ansari, K., additional, Chiocca, E. A., additional, Godlewski, J., additional, Brown, K., additional, Kwatra, M., additional, Bui, T., additional, Zhu, S., additional, Kozono, D., additional, Li, J., additional, Kushwaha, D., additional, Carter, B., additional, Chen, C., additional, Schulte, J., additional, Srikanth, M., additional, Das, S., additional, Zhang, J., additional, Lathia, J., additional, Yin, L., additional, Rich, J., additional, Olson, E., additional, Kessler, J., additional, Chenn, A., additional, Cherry, A., additional, Haas, B., additional, Lin, Y. H., additional, Ong, S.-E., additional, Stella, N., additional, Cifarelli, C. P., additional, Griffin, R. J., additional, Cong, D., additional, Zhu, W., additional, Shi, Y., additional, Clark, P., additional, Kuo, J., additional, Hu, S., additional, Sun, D., additional, Bookland, M., additional, Darbinian, N., additional, Dey, A., additional, Robitaille, M., additional, Remke, M., additional, Faury, D., additional, Maier, C., additional, Malhotra, A., additional, Jabado, N., additional, Taylor, M., additional, Angers, S., additional, Kenney, A., additional, Ren, X., additional, Zhou, H., additional, Schur, M., additional, Baweja, A., additional, Singh, M., additional, Erdreich-Epstein, A., additional, Fu, J., additional, Koul, D., additional, Yao, J., additional, Saito, N., additional, Zheng, S., additional, Verhaak, R., additional, Lu, Z., additional, Yung, W. K. A., additional, Gomez, G., additional, Volinia, S., additional, Croce, C., additional, Brennan, C., additional, Cavenee, W., additional, Furnari, F., additional, Lopez, S. G., additional, Qu, D., additional, Petritsch, C., additional, Gonzalez-Huarriz, M., additional, Aldave, G., additional, Ravi, D., additional, Rubio, A., additional, Diez-Valle, R., additional, Marigil, M., additional, Jauregi, P., additional, Vera, B., additional, Rocha, A. A. d. l., additional, Tejada-Solis, S., additional, Alonso, M. M., additional, Gopal, U., additional, Isaacs, J., additional, Gruber-Olipitz, M., additional, Dabral, S., additional, Ramkissoon, S., additional, Kung, A., additional, Pak, E., additional, Chung, J., additional, Theisen, M., additional, Sun, Y., additional, Monrose, V., additional, Franchetti, Y., additional, Shulman, D., additional, Redjal, N., additional, Tabak, B., additional, Beroukhim, R., additional, Zhao, J., additional, Buonamici, S., additional, Ligon, K., additional, Kelleher, J., additional, Segal, R., additional, Canton, D., additional, Diaz, P., additional, Scott, J., additional, Hara, K., additional, Kageji, T., additional, Mizobuchi, Y., additional, Kitazato, K., additional, Okazaki, T., additional, Fujihara, T., additional, Nakajima, K., additional, Mure, H., additional, Kuwayama, K., additional, Hara, T., additional, Nagahiro, S., additional, Hill, L., additional, Botfield, H., additional, Hossain-Ibrahim, K., additional, Logan, A., additional, Cruickshank, G., additional, Liu, Y., additional, Gilbert, M., additional, Kyprianou, N., additional, Rangnekar, V., additional, Horbinski, C., additional, Hu, Y., additional, Vo, C., additional, Li, Z., additional, Ke, C., additional, Ru, N., additional, Hess, K. R., additional, Linskey, M. E., additional, Zhou, Y.-a. H., additional, Hu, F., additional, Vinnakota, K., additional, Wolf, S., additional, Kettenmann, H., additional, Jackson, P. J., additional, Larson, J. D., additional, Beckmann, D. A., additional, Moriarity, B. S., additional, Largaespada, D. A., additional, Jalali, S., additional, Agnihotri, S., additional, Singh, S., additional, Burrell, K., additional, Croul, S., additional, Zadeh, G., additional, Kang, S.-H., additional, Yu, M. O., additional, Song, N.-H., additional, Park, K.-J., additional, Chi, S.-G., additional, Chung, Y.-G., additional, Kim, S. K., additional, Kim, J. W., additional, Kim, J. Y., additional, Kim, J. E., additional, Choi, S. H., additional, Kim, T. M., additional, Lee, S.-H., additional, Kim, S.-K., additional, Park, S.-H., additional, Kim, I. H., additional, Park, C.-K., additional, Jung, H.-W., additional, Koldobskiy, M., additional, Ahmed, I., additional, Ho, G., additional, Snowman, A., additional, Raabe, E., additional, Eberhart, C., additional, Snyder, S., additional, Gugel, I., additional, Bornemann, A., additional, Pantazis, G., additional, Mack, S., additional, Shih, D., additional, Sabha, N., additional, Tatagiba, M., additional, Krischek, B., additional, Schulte, A., additional, Liffers, K., additional, Kathagen, A., additional, Riethdorf, S., additional, Westphal, M., additional, Lamszus, K., additional, Lee, J. S., additional, Xiao, J., additional, Patel, P., additional, Schade, J., additional, Wang, J., additional, Deneen, B., additional, Song, H.-R., additional, Leiss, L., additional, Gjerde, C., additional, Saed, H., additional, Rahman, A., additional, Lellahi, M., additional, Enger, P. O., additional, Leung, R., additional, Gil, O., additional, Lei, L., additional, Canoll, P., additional, Sun, S., additional, Lee, D., additional, Ho, A. S. W., additional, Pu, J. K. S., additional, Zhang, X.-q., additional, Lee, N. P., additional, Dat, P. J. R., additional, Leung, G. K. K., additional, Loetsch, D., additional, Steiner, E., additional, Holzmann, K., additional, Pirker, C., additional, Hlavaty, J., additional, Petznek, H., additional, Hegedus, B., additional, Garay, T., additional, Mohr, T., additional, Sommergruber, W., additional, Lukiw, W. J., additional, Jones, B. M., additional, Zhao, Y., additional, Bhattacharjee, S., additional, Culicchia, F., additional, Magnus, N., additional, Garnier, D., additional, Meehan, B., additional, McGraw, S., additional, Hashemi, M., additional, Lee, T. H., additional, Milsom, C., additional, Gerges, N., additional, Trasler, J., additional, Pawlinski, R., additional, Mackman, N., additional, Rak, J., additional, Maherally, Z., additional, Thorne, A., additional, An, Q., additional, Barbu, E., additional, Fillmore, H., additional, Pilkington, G., additional, Tan, S. L., additional, Tan, S., additional, Choi, S., additional, Potts, C., additional, Ford, D. A., additional, Nahle, Z., additional, Kenney, A. M., additional, Matlaf, L., additional, Khan, S., additional, Zider, A., additional, Singer, E., additional, Cobbs, C., additional, Soroceanu, L., additional, McFarland, B. C., additional, Hong, S. W., additional, Rajbhandari, R., additional, Twitty, G. B., additional, Gray, G. K., additional, Yu, H., additional, Benveniste, E. N., additional, Nozell, S. E., additional, Minata, M., additional, Kim, S., additional, Mao, P., additional, Kaushal, J., additional, Nakano, I., additional, Mizowaki, T., additional, Sasayama, T., additional, Tanaka, K., additional, Mizukawa, K., additional, Nishihara, M., additional, Nakamizo, S., additional, Tanaka, H., additional, Kohta, M., additional, Hosoda, K., additional, Kohmura, E., additional, Moeckel, S., additional, Meyer, K., additional, Leukel, P., additional, Bogdahn, U., additional, Riehmenschneider, M. J., additional, Bosserhoff, A. K., additional, Spang, R., additional, Hau, P., additional, Mukasa, A., additional, Watanabe, A., additional, Ogiwara, H., additional, Aburatani, H., additional, Mukherjee, J., additional, Obha, S., additional, See, W., additional, Pieper, R., additional, Otsuka, R., additional, Kung, D., additional, Sinha, T., additional, Meares, G., additional, Nozell, S., additional, Ott, M., additional, Litzenburger, U., additional, Rauschenbach, K., additional, Bunse, L., additional, Pusch, S., additional, Ochs, K., additional, Sahm, F., additional, Opitz, C., additional, von Deimling, A., additional, Wick, W., additional, Platten, M., additional, Peruzzi, P., additional, Read, R., additional, Fenton, T., additional, Wykosky, J., additional, Vandenberg, S., additional, Babic, I., additional, Iwanami, A., additional, Yang, H., additional, Mischel, P., additional, Thomas, J., additional, Ronellenfitsch, M. W., additional, Thiepold, A. L., additional, Harter, P. N., additional, Mittelbronn, M., additional, Steinbach, J. P., additional, Rybakova, Y., additional, Kalen, A., additional, Sarsour, E., additional, Goswami, P., additional, Silber, J., additional, Harinath, G., additional, Aldaz, B., additional, Fabius, A. W. M., additional, Turcan, S., additional, Chan, T. A., additional, Huse, J. T., additional, Sonabend, A. M., additional, Bansal, M., additional, Guarnieri, P., additional, Soderquist, C., additional, Yun, J., additional, Kennedy, B., additional, Sisti, J., additional, Bruce, S., additional, Bruce, R., additional, Shakya, R., additional, Ludwig, T., additional, Rosenfeld, S., additional, Sims, P. A., additional, Bruce, J. N., additional, Califano, A., additional, Stockhausen, M.-T., additional, Kristoffersen, K., additional, Olsen, L. S., additional, Poulsen, H. S., additional, Stringer, B., additional, Day, B., additional, Barry, G., additional, Piper, M., additional, Jamieson, P., additional, Ensbey, K., additional, Bruce, Z., additional, Richards, L., additional, Boyd, A., additional, Sufit, A., additional, Burleson, T., additional, Le, J. P., additional, Keating, A. K., additional, Sundstrom, T., additional, Varughese, J. K., additional, Harter, P., additional, Prestegarden, L., additional, Petersen, K., additional, Azuaje, F., additional, Tepper, C., additional, Ingham, E., additional, Even, L., additional, Johnson, S., additional, Skaftnesmo, K. O., additional, Lund-Johansen, M., additional, Bjerkvig, R., additional, Ferrara, K., additional, Thorsen, F., additional, Takeshima, H., additional, Yamashita, S., additional, Yokogami, K., additional, Mizuguchi, S., additional, Nakamura, H., additional, Kuratsu, J., additional, Fukushima, T., additional, Morishita, K., additional, Tang, Y., additional, Vaka, D., additional, Chen, S., additional, Ponnuswami, A., additional, Cho, Y.-J., additional, Monje, M., additional, Nakamura, T., additional, Cahill, D., additional, Tiemann, K., additional, Hedman, H., additional, Niclou, S. P., additional, Timmer, M., additional, Tjiong, R., additional, Rohn, G., additional, Goldbrunner, R., additional, Stavrinou, P., additional, Perrech, M., additional, Tokita, M., additional, Mikheev, S., additional, Sellers, D., additional, Mikheev, A., additional, Kosai, Y., additional, Rostomily, R., additional, Tritschler, I., additional, Seystahl, K., additional, Schroeder, J. J., additional, Weller, M., additional, Wade, A., additional, Robinson, A. E., additional, Phillips, J. J., additional, Gong, Y., additional, Ma, Y., additional, Cheng, Z., additional, Thompson, R., additional, Fan, Q.-W., additional, Cheng, C., additional, Gustafson, W., additional, Charron, E., additional, Zipper, P., additional, Wong, R., additional, Chen, J., additional, Lau, J., additional, Knobbe-Thosen, C., additional, Jura, N., additional, Reifenberger, G., additional, Shokat, K., additional, Weiss, W., additional, Wu, S., additional, Hu, J., additional, Taylor, T., additional, Villa, G. R., additional, Mischel, P. S., additional, Gonias, S. L., additional, Yamashita, D., additional, Kondo, T., additional, Takahashi, H., additional, Inoue, A., additional, Kohno, S., additional, Harada, H., additional, Ohue, S., additional, Ohnishi, T., additional, Li, P., additional, Ng, J., additional, Yuelling, L., additional, Du, F., additional, Curran, T., additional, Yang, Z.-j., additional, Zhu, D., additional, Castellino, R. C., additional, Van Meir, E. G., additional, Begum, G., additional, Wang, Q., additional, Yang, S.-S., additional, Lin, S.-H., additional, and Kahle, K., additional

Published
2013
Full Text
View/download PDF

13. STEM CELLS

Author

Joshi, K., primary, Gupta, S., additional, Mazumder, S., additional, Okemoto, Y., additional, Angenieux, B., additional, Kornblum, H., additional, Nakano, I., additional, Synowitz, M., additional, Kumar, J., additional, Petrosino, S., additional, Imperatore, R., additional, Smith, E., additional, Wendt, P., additional, Erdmann, B., additional, Nuber, U., additional, Matiash, V., additional, Chirasani, S., additional, Cristino, L., additional, DiMarzo, V., additional, Kettenmann, H., additional, Glass, R., additional, Soroceanu, L., additional, Matlaf, L., additional, Cobbs, C., additional, Kim, Y.-W., additional, Kim, S. H., additional, Kwon, C., additional, Han, D.-y., additional, Kim, E. H., additional, Chang, J. H., additional, Liu, J.-L., additional, Kim, Y. H., additional, Kim, S., additional, Long, P. M., additional, Viapiano, M. S., additional, Jaworski, D. M., additional, Kanemura, Y., additional, Shofuda, T., additional, Kanematsu, D., additional, Matsumoto, Y., additional, Yamamoto, A., additional, Nonaka, M., additional, Moriuchi, S., additional, Nakajima, S., additional, Suemizu, H., additional, Nakamura, M., additional, Okada, Y., additional, Okano, H., additional, Yamasaki, M., additional, Price, R. L., additional, Song, J., additional, Bingmer, K., additional, Zimmerman, P., additional, Rivera, A., additional, Yi, J.-Y., additional, Cook, C., additional, Chiocca, E. A., additional, Kwon, C.-H., additional, Kang, S.-G., additional, Shin, H.-D., additional, Mok, H.-S., additional, Park, N.-R., additional, Sim, J. K., additional, Shin, H. J., additional, Park, Y. K., additional, Jeun, S. S., additional, Hong, Y.-K., additional, Lang, F. F., additional, McKenzie, B. A., additional, Zemp, F. J., additional, Lun, X., additional, Narendran, A., additional, McFadden, G., additional, Kurz, E., additional, Forsyth, P., additional, Talsma, C. E., additional, Flack, C. G., additional, Zhu, T., additional, He, X., additional, Soules, M., additional, Heth, J. A., additional, Muraszko, K., additional, Fan, X., additional, Chen, L., additional, Guerrero-Cazares, H., additional, Noiman, L., additional, Smith, C., additional, Beltran, N., additional, Levchenko, A., additional, Quinones-Hinojosa, A., additional, Peruzzi, P., additional, Godlewski, J., additional, Lawler, S. E., additional, Sarkar, S., additional, Doring, A., additional, Wang, X., additional, Kelly, J., additional, Hader, W., additional, Dunn, J. F., additional, Kinniburgh, D., additional, Robbins, S., additional, Cairncross, G., additional, Weiss, S., additional, Yong, V. W., additional, Vollmann-Zwerenz, A., additional, Velez-Char, N., additional, Jachnik, B., additional, Ramm, P., additional, Leukel, P., additional, Bogdahn, U., additional, Hau, P., additional, Kim, S.-H., additional, Lee, M. K., additional, Chwae, Y.-J., additional, Yoo, B. C., additional, Kim, K.-H., additional, Kristoffersen, K., additional, Stockhausen, M.- T., additional, Poulsen, H. S., additional, Kaluzova, M., additional, Machaidze, R., additional, Wankhede, M., additional, Hadjipanayis, C. G., additional, Romane, A. M., additional, Sim, F. J., additional, Wang, S., additional, Chandler-Militello, D., additional, Li, X., additional, Al Fanek, Y., additional, Walter, K., additional, Johnson, M., additional, Achanta, P., additional, Goldman, S. A., additional, Shinojima, N., additional, Hossain, A., additional, Takezaki, T., additional, Gumin, J., additional, Gao, F., additional, Nwajei, F., additional, Cheung, V., additional, Figueroa, J., additional, Pellegatta, S., additional, Orzan, F., additional, Anghileri, E., additional, Guzzetti, S., additional, Porrati, P., additional, Eoli, M., additional, Finocchiaro, G., additional, Fu, J., additional, Koul, D., additional, Yao, J., additional, Gumin, J. G., additional, Sulman, E., additional, Lang, F., additional, Aldape, K. K., additional, Colman, H., additional, Yung, A. W., additional, Aldape, K., additional, Alonso, M. M., additional, Manterola, L., additional, urquiza, L., additional, Cortes-Santiago, N., additional, Diez-Valle, R., additional, Tejada-Solis, S., additional, Garcia-foncillas, J., additional, Fueyo, J., additional, Gomez-Manzano, C., additional, Nguyen, S., additional, Stechishin, O., additional, Luchman, A., additional, Lathia, J. D., additional, Gallagher, J., additional, Li, M., additional, Myers, J., additional, Hjelmeland, A., additional, Huang, A., additional, Rich, J., additional, Bhat, K., additional, Vaillant, B., additional, Balasubramaniyan, V., additional, Ezhilarasan, R., additional, Hitomi, M., additional, Gadani, S., additional, Adkins, J., additional, Vasanji, A., additional, Wu, Q., additional, Soeda, A., additional, McLendon, R., additional, Chenn, A., additional, Park, D., additional, Weinstein, J. N., additional, Alfred Yung, W. K., additional, Zagzag, D., additional, Esencay, M., additional, Klopsis, D., additional, Liu, M., additional, Narayana, A., additional, Parker, E., additional, Golfinos, J., additional, Clark, P. A., additional, Kandela, I. K., additional, Weichert, J. P., additional, Kuo, J. S., additional, Fouse, S. D., additional, Nagarajan, R. P., additional, Nakamura, J., additional, James, C. D., additional, Chang, S., additional, Costello, J. F., additional, Gong, X., additional, Kankar, G., additional, Di, K., additional, Reeves, A., additional, Linskey, M., additional, Bota, D. A., additional, Schmid, R. S., additional, Bash, R. E., additional, Vitucci, M., additional, Werneke, A. M., additional, Miller, C. R., additional, Kim, E., additional, Kim, M., additional, Kim, K., additional, Lee, J., additional, Du, F., additional, Li, P., additional, Wechsler-Reya, R., additional, and Yang, Z.-j., additional

Published
2011
Full Text
View/download PDF

14. Stem Cells

Author

He, H., primary, Emmett, M. R., additional, Marshall, A. G., additional, Ji, Y., additional, Conrad, C. A., additional, Priebe, W., additional, Colman, H., additional, Lang, F. F., additional, Madden, T. L., additional, Kristoffersen, K., additional, Stockhausen, M.-T., additional, Poulsen, H. S., additional, Binder, Z. A., additional, Orr, B., additional, Lim, M., additional, Weingart, J. D., additional, Brem, H., additional, Olivi, A., additional, Riggins, G. J., additional, Gallia, G. L., additional, Litofsky, N. S., additional, Miller, D. C., additional, Rath, P., additional, Anthony, D. C., additional, Feng, Q., additional, Franklin, C., additional, Pei, L., additional, Free, A., additional, Kirk, M. D., additional, Shi, H., additional, Timmer, M., additional, Theiss, H., additional, Juerchott, K., additional, Ries, C., additional, Paron, I., additional, Franz, W., additional, Selbig, J., additional, Guo, K., additional, Tonn, J. C., additional, Schichor, C., additional, Zhou, Y.-H., additional, Hu, Y., additional, Pioli, P. D., additional, Rajneesh, K., additional, Limoli, C. L., additional, Yu, L., additional, Hess, K. R., additional, Linskey, M. E., additional, Faber, F., additional, Jaeger, D., additional, Thorsteinsdottir, J., additional, Albrecht, V., additional, Tonn, J.-C., additional, Price, R., additional, Song, J., additional, Zimmerman, P., additional, Duale, H., additional, Rivera, A., additional, Kaur, B., additional, Parada, L., additional, Cook, C., additional, Chiocca, E. A., additional, Kwon, C.-H., additional, Munoz, D. M., additional, Guha, A., additional, Estrada-Bernal, A., additional, Van Brocklyn, J. R., additional, Gu, C., additional, Mahasenan, K. V., additional, Joshi, K., additional, Gupta, S., additional, Mattson, A., additional, Li, C., additional, Nakano, I., additional, Chi, A. S., additional, Rheinbay, E., additional, Wakimoto, H., additional, Gillespie, S., additional, Kasif, S., additional, Rabkin, S. D., additional, Martuza, R. L., additional, Bernstein, B. E., additional, Skirboll, S. L., additional, Wurdak, H., additional, Zhu, S., additional, Romero, A., additional, Lorger, M., additional, Watson, J., additional, Chiang, C.-y., additional, Zhang, J., additional, Natu, V. S., additional, Lairson, L. L., additional, Walker, J. R., additional, Trussell, C. M., additional, Harsh, G. R., additional, Vogel, H., additional, Felding-Habermann, B., additional, Orth, A. P., additional, Miraglia, L. J., additional, Rines, D. R., additional, Schultz, P. G., additional, Hide, T., additional, Takezaki, T., additional, Nakamura, H., additional, Makino, K., additional, Kuratsu, J.-i., additional, Kondo, T., additional, Yao, J., additional, Kim, Y.-W., additional, Koul, D., additional, Almeida, J. S., additional, Weinstein, J. N., additional, Alfred Yung, W. K., additional, Miyazaki, T., additional, Chaudhury, A. R., additional, Wong, A. J., additional, Del Vecchio, C., additional, Mitra, S., additional, Han, S.-Y., additional, Holgado-Madruga, M., additional, Gupta, P., additional, Golebiewska, A., additional, Brons, N. H., additional, Bjerkvig, R., additional, Niclou, S. P., additional, Ramm, P., additional, Vollmann-Zwerenz, A., additional, Beier, C., additional, Aigner, L., additional, Bogdahn, U., additional, Kalbitzer, H. R., additional, Hau, P., additional, Sanzey, M., additional, Vallar, L., additional, Tamura, K., additional, Aoyagi, M., additional, Ando, N., additional, Ogishima, T., additional, Yamamoto, M., additional, Ohno, K., additional, Perin, A., additional, Fung, K. H., additional, Longatti, P., additional, Guiot, M.-C., additional, Del Maestro, R. F., additional, Rossi, S., additional, Stechishin, O., additional, Weiss, S., additional, Stifani, S., additional, Goodman, L., additional, Gao, F., additional, Gumin, J., additional, Ezhilarasan, R., additional, Love, P., additional, George, A., additional, Lang, F., additional, Aldape, K., additional, Sulman, E. P., additional, Soeda, A., additional, Lee, D.-H., additional, Shaffrey, M. E., additional, Oldfield, E. H., additional, Park, D. M., additional, Dietrich, J., additional, Han, R., additional, Noble, M., additional, Yang, M. Y., additional, Liu, X., additional, Madhankumar, A. B., additional, Sheehan, J., additional, Slagle-Webb, B., additional, Connor, J. R., additional, Fu, J., additional, Shen, R.-J., additional, Kaluzova, M., additional, Machaidze, R., additional, Nduom, E. N. K., additional, Burden, C. T., additional, Hadjipanayis, C. G., additional, Lei, L., additional, Sonabend, A., additional, Guarnieri, P., additional, Ludwig, T., additional, Rosenfeld, S., additional, Bruce, J., additional, Canoll, P., additional, Vaillant, B. D., additional, Bhat, K., additional, Balasubramaniyam, V., additional, Wang, S., additional, Sulman, E., additional, Goodman, L. D., additional, Love, P. N., additional, Soules, M., additional, Zhu, T., additional, Flack, C., additional, Talsma, C., additional, Hamm, L., additional, Muraszko, K., additional, Fan, X., additional, Matsuoka, Y., additional, Kawano, Y., additional, Kobayashi, D., additional, Kumagai, J., additional, Frank, R. T., additional, Najbauer, J., additional, Aboody, K. S., additional, Metz, M., additional, Garcia, E., additional, Aramburo, S., additional, Valenzuela, V., additional, Gutova, M., additional, Annala, A. J., additional, Barish, M., additional, Danks, M., additional, Kim, S. U., additional, Portnow, J., additional, Hofstetter, C., additional, Gursel, D., additional, Mubita, L., additional, Holland, E., additional, Boockvar, J., additional, Monje, M., additional, Freret, M., additional, Masek, M., additional, Edwards, M. S., additional, Fisher, P. G., additional, and Beachy, P., additional

Published
2010
Full Text
View/download PDF

20. Practical verification of embedded software

Author

Straunstrup, J., primary, Andersen, H.R., additional, Hulgaard, H., additional, Lind-Nielsen, J., additional, Behrmann, G., additional, Kristoffersen, K., additional, Skou, A., additional, Leerberg, HH., additional, and Theilgaard, N.B., additional

Published
2000
Full Text
View/download PDF

26. Cellular immunity in pregnancy: blast transformation and rosette formation of maternal T and B lymphocytes.

Author

Birkeland, S. A. and Kristoffersen, K.

Subjects
*CELLULAR immunity, *IMMUNE response, *PHYSIOLOGY, *PREGNANCY, *LEUCOCYTES, *PATIENTS
Abstract

In vitro tests of cellular immune responses, using lymphocyte transformation tests and rosette tests for T and B lymphocytes, were studied in a cross-section analysis of a total of fifty-five patients in six groups (non-pregnant, 2-3 months pregnant, 4-5 months pregnant, 6-7 months pregnant, at parturition and 3 months after parturition). No pregnancy-related changes were found in the numbers of T, B or null cells, nor changes in PHA, PWM or MLC responses, hut a significant reversible depression of the PPD response was found in the second half of pregnancy. [ABSTRACT FROM AUTHOR]

Published
1977

30. Cross sectional early mitral flow velocity profiles from colour Doppler.

Author

Samstad, S O, Torp, H G, Linker, D T, Rossvoll, O, Skjaerpe, T, Johansen, E, Kristoffersen, K, Angelsen, B A, and Hatle, L

Abstract

Instantaneous cross sectional flow velocity profiles from early mitral flow in 10 healthy men were constructed by time interpolation of the velocity data from each point in sequentially delayed two dimensional digital Doppler ultrasound maps. This interpolation allows correction of the artificially produced skewness of velocities across the flow sector caused by the time taken to scan the flow sector for velocity recording of pulsatile blood flow. These results suggested that early mitral flow studied in an apical four chamber view is variably skewed both at the leaflet tips and at the annulus. The maximum flow velocity overestimated the cross sectional mean velocity at the same time by a factor of 1.2-2.2. Also the maximum time velocity integral overestimated the cross sectional mean time velocity integral to the same extent. This cross sectional skew must be taken into account when calculation of blood flow is based on recordings with pulsed wave Doppler ultrasound from a single sample volume. [ABSTRACT FROM PUBLISHER]

Published
1989
Full Text
View/download PDF

33. Cellular immunity in pregnancy: blast transformation and rosette formation of maternal T and B lymphocytes: A cross-section analysis

Author

Birkeland, S A and Kristoffersen, K

Subjects
Adult, B-Lymphocytes, Immunity, Cellular, Labor, Obstetric, Rosette Formation, Adolescent, T-Lymphocytes, chemical and pharmacologic phenomena, Lymphocyte Activation, Tuberculin, Pregnancy, Lectins, Humans, Female, Lymphocyte Culture Test, Mixed, Research Article
Abstract

In vitro tests of cellular immune responses, using lymphocyte transformation tests and rosette tests for T and B lymphocytes, were studied in a cross-section analysis of a total of fifty-five patients in six groups (non-pregnant, 2--3 months pregnant, 4--5 months pregnant, 6--7 months pregnant, at parturition and 3 months after parturition). No pregnancy-related changes were found in the numbers of T, B or null cells, nor changes in PHA, PWM or MLC responses, but a significant reversible depression of the PPD response was found in the second half of pregnancy.

Published
1977

34. Monitoring meticillin resistant Staphylococcus aureus and its spread in Copenhagen, Denmark, 2013, through routine whole genome sequencing

Author

Mette Damkjær Bartels, Larner-Svensson, H., Meiniche, H., Kristoffersen, K., Schonning, K., Nielsen, J. B., Rohde, S. M., Christensen, L. B., Skibsted, A. W., Jarlov, J. O., Johansen, H. K., Andersen, L. P., Petersen, I. S., Crook, D. W., Bowden, R., Boye, K., Worning, P., and Westh, H.

Subjects
Methicillin-Resistant Staphylococcus aureus, Molecular Typing, Molecular Epidemiology, Leukocidins, Denmark, Bacterial Toxins, Exotoxins, Humans, Sequence Analysis, DNA, Staphylococcal Infections, Staphylococcal Protein A, Polymorphism, Single Nucleotide, Genome, Bacterial
Abstract

Typing of meticillin resistant Staphylococcus aureus(MRSA) by whole genome sequencing (WGS) is performedroutinely in Copenhagen since January 2013.We describe the relatedness, based on WGS data andepidemiological data, of 341 MRSA isolates. Thesecomprised all MRSA (n = 300) identified in Copenhagenin the first five months of 2013. Moreover, becauseMRSA of staphylococcal protein A (spa)-type 304(t304), sequence type (ST) 6 had been associated witha continuous neonatal ward outbreak in Copenhagenstarting in 2011, 41 t304 isolates collected in the citybetween 2010 and 2012 were also included. Isolatesfrom 2013 found to be of t304, ST6 (n=14) were comparedto the 41 earlier isolates. In the study, isolatesof clonal complex (CC) 22 were examined in detail,as this CC has been shown to include the hospitalacquiredepidemic MRSA (EMRSA-15) clone. Finally,all MRSA ST80 were also further analysed, as representativesof an important community-acquired MRSAin Europe. Overall the analysis identified 85 spa-typesand 35 STs from 17 CCs. WGS confirmed the relatednessof epidemiologically linked t304 neonatal outbreakisolates. Several non-outbreak related patientshad isolates closely related to the neonatal isolatessuggesting unrecognised community chains of transmissionand insufficient epidemiological data. Onlyfour CC22 isolates were related to EMRSA-15. No communityspread was observed among the 13 ST80 isolates.WGS successfully replaced conventional typingand added information to epidemiological surveillance.Creation of a MRSA database allows clusteringof isolates based on single nucleotide polymorphism(SNP) calling and has improved our understanding ofMRSA transmission. Typing of meticillin resistant Staphylococcus aureus (MRSA) by whole genome sequencing (WGS) is performed routinely in Copenhagen since January 2013. We describe the relatedness, based on WGS data and epidemiological data, of 341 MRSA isolates. These comprised all MRSA (n = 300) identified in Copenhagen in the first five months of 2013. Moreover, because MRSA of staphylococcal protein A (spa)-type 304 (t304), sequence type (ST) 6 had been associated with a continuous neonatal ward outbreak in Copenhagen starting in 2011, 41 t304 isolates collected in the city between 2010 and 2012 were also included. Isolates from 2013 found to be of t304, ST6 (n=14) were compared to the 41 earlier isolates. In the study, isolates of clonal complex (CC) 22 were examined in detail, as this CC has been shown to include the hospital-acquired epidemic MRSA (EMRSA-15) clone. Finally, all MRSA ST80 were also further analysed, as representatives of an important community-acquired MRSA in Europe. Overall the analysis identified 85 spa-types and 35 STs from 17 CCs. WGS confirmed the relatedness of epidemiologically linked t304 neonatal outbreak isolates. Several non-outbreak related patients had isolates closely related to the neonatal isolates suggesting unrecognised community chains of transmission and insufficient epidemiological data. Only four CC22 isolates were related to EMRSA-15. No community spread was observed among the 13 ST80 isolates. WGS successfully replaced conventional typing and added information to epidemiological surveillance. Creation of a MRSA database allows clustering of isolates based on single nucleotide polymorphism (SNP) calling and has improved our understanding of MRSA transmission.

35. New quality regulations versus established nursing home practice: a qualitative study

Author

Sandvoll Anne, Kristoffersen Kjell, and Hauge Solveig

Subjects
Qualitative methods, Nursing homes, Nursing practice, Regulations, And routines, Nursing, RT1-120
Abstract

Abstract Background Western governments have initiated reforms to improve the quality of care for nursing home residents. Most of these reforms encompass the use of regulations and national quality indicators. In the Norwegian context, these regulations comprise two pages of text that are easy to read and understand. They focus particularly on residents’ rights to plan their day-to-day life in nursing homes. However, the research literature indicates that the implementation of the new regulations, particularly if they aim to change nursing practice, is extremely challenging. The aim of this study was to further explore and describe nursing practice to gain a deeper understanding of why it is so hard to implement the new regulations. Methods For this qualitative study, an ethnographic design was chosen to explore and describe nursing practice. Fieldwork was conducted in two nursing homes. In total, 45 nurses and nursing aides were included in participant observation, and 10 were interviewed at the end of the field study. Results Findings indicate that the staff knew little about the new quality regulations, and that the quality of their work was guided by other factors rooted in their nursing practice. Further analyses revealed that the staff appeared to be committed to daily routines and also that they always seemed to know what to do. Having routines and always knowing what to do mutually strengthen and enhance each other, and together they form a powerful force that makes daily nursing care a taken-for-granted activity. Conclusion New regulations are challenging to implement because nursing practices are so strongly embedded. Improving practice requires systematic and deeply rooted practical change in everyday action and thinking.

Published
2012
Full Text
View/download PDF

37. Differential Effects of Lipid Bilayers on αPSM Peptide Functional Amyloid Formation.

Author

Kristoffersen K, Hansen KH, and Andreasen M

Subjects
Humans, Animals, Staphylococcus aureus, Amyloidogenic Proteins, Cell Membrane, Mammals, Lipid Bilayers, Lipopolysaccharides
Abstract

Phenol-soluble modulins (PSMs) are key virulence factors of S. aureus , and they comprise the structural scaffold of biofilm as they self-assemble into functional amyloids. They have been shown to interact with cell membranes as they display toxicity towards human cells through cell lysis, with αPSM3 being the most cytotoxic. In addition to causing cell lysis in mammalian cells, PSMs have also been shown to interact with bacterial cell membranes through antimicrobial effects. Here, we present a study on the effects of lipid bilayers on the aggregation mechanism of αPSM using chemical kinetics to study the effects of lipid vesicles on the aggregation kinetics and using circular dichroism (CD) spectroscopy, Fourier-transform infrared (FTIR) spectroscopy and transmission electron microscopy (TEM) to investigate the corresponding secondary structure of the aggregates. We found that the effects of lipid bilayers on αPSM aggregation were not homogeneous between lipid type and αPSM peptides, although none of the lipids caused changes in the dominating aggregation mechanism. In the case of αPSM3, all types of lipids slowed down aggregation to a varying degree, with 1,2-dioleoyl-sn-glycero-3-phosphocholine (DOPC) having the most pronounced effect. For αPSM1, lipids had opposite effects, where DOPC decelerated aggregation and lipopolysaccharide (LPS) accelerated the aggregation, while 1,2-dioleoyl-sn-glycero-3-phospho-rac-(1-glycerol) (DOPG) had no effect. For αPSM4, both DOPG and LPS accelerated the aggregation, but only at high concentration, while DOPC showed no effect. None of the lipids was capable of inducing aggregation of αPSM2. Our data reveal a complex interaction pattern between PSMs peptides and lipid bilayers that causes changes in the aggregation kinetics by affecting different kinetic parameters along with only subtle changes in morphology.

Published
2023
Full Text
View/download PDF

38. Lifestyle factors as mediators of area-level socio-economic differentials in cardiovascular disease risk factors. The Tromsø Study.

Author

Tiwari S, Cerin E, Wilsgaard T, Løvsletten O, Njølstad I, Grimsgaard S, Hopstock LA, Schirmer H, Rosengren A, Kristoffersen K, and Løchen ML

Abstract

Introduction: Cardiovascular disease (CVD) is a leading cause of death and disability and living in areas with low socio-economic status (SES) is associated with increased risk of CVD. Lifestyle factors such as smoking, physical inactivity, an unhealthy diet and harmful alcohol use are main risk factors that contribute to other modifiable risk factors, such as hypertension, raised blood cholesterol, obesity, and diabetes. The potential impact of area-level socio-economic status (ASES) on metabolic CVD risk factors via lifestyle behaviors independent of individual SES has not been investigated previously., Aims: To estimate associations of ASES with CVD risk factors and the mediating role of lifestyle behaviors independent of individual-level SES., Methods: In this cross-sectional study, we included 19,415 participants (52% women) from the seventh survey of the Tromsø Study (2015-2016) (Tromsø7). The exposure variable ASES was created by aggregating individual-level SES variables (education, income, housing ownership) at the geographical subdivision level. Individual-level SES data and geographical subdivision of Tromsø municipality (36 areas) were obtained from Statistics Norway. Variables from questionnaires and clinical examinations obtained from Tromsø7 were used as mediators (smoking, snuff, alcohol, and physical activity), while the outcome variables were body mass index (BMI), total/high-density lipoprotein (HDL) cholesterol ratio, waist circumference, hypertension, diabetes. Mediation and mediated moderation analysis were performed with age as a moderator, stratified by sex., Results: ASES was significantly associated with all outcome variables. CVD risk factor level declined with an increase in ASES. These associations were mediated by differences in smoking habits, alcohol use and physical activity. The associations of ASES with total/HDL cholesterol ratio and waist circumference (women) were moderated by age, and the moderating effects were mediated by smoking and physical activity in both sexes. The largest mediated effects were seen in the associations of ASES with total/HDL cholesterol ratio, with the mediators accounting for 43% of the observed effects., Conclusions: Living in lower SES areas is associated with increased CVD risk due to unhealthy lifestyle behaviors, such as smoking, alcohol use and physical inactivity. These associations were stronger in women and among older participants., Competing Interests: None., (© 2022 The Authors.)

Published
2022
Full Text
View/download PDF

39. When care situations evoke difficult emotions in nursing staff members: an ethnographic study in two Norwegian nursing homes.

Author

Sandvoll AM, Grov EK, Kristoffersen K, and Hauge S

Abstract

Background: Caring practice in nursing homes is a complex topic, especially the challenges of meeting the basic needs of residents when their behaviour evokes difficult emotions. Cognitive and physical changes related to aging and disability can contribute to behaviours considered to be unacceptable. For example, resident behaviours such as spitting, making a mess with food or grinding teeth are behaviours that most people do not want to see, hear or experience. The aim of this study was to gain a deeper understanding of how nursing home staff members deal with such behaviours in care situations., Methods: This article draws on ethnographic data to describe how nursing home staff members manage unpleasant resident behaviours. The study was based on two long-term units in two Norwegian public nursing homes. The Region's Medical Ethics Committee and the Norwegian Social Science Data Services granted approval. In total, 45 participants (37 nursing aides and eight nurses) agreed to participate in this study. Ten of the participants were interviewed at the end of the field study., Results: This study indicates that nursing home staff members experience difficult emotions related to some residents' behaviours. However, they found these feelings difficult to express and rarely verbalized them openly. In addition, they were characterized by a strong obligation to help all residents, despite their own feelings. Therefore, it appears that an inner struggle occurs as a part of everyday practice., Conclusions: Despite these difficult emotions, nursing staff members believed that they needed to manage their responses and continued to offer good care to all residents. These findings extend our understanding of this unarticulated part of nursing home practice.

Published
2015
Full Text
View/download PDF

40. Error analysis of subaperture processing in 1-D ultrasound arrays.

Author

Zhao KQ, Bjåstad TG, and Kristoffersen K

Abstract

To simplify the medical ultrasound system and reduce the cost, several techniques have been proposed to reduce the interconnections between the ultrasound probe and the back-end console. Among them, subaperture processing (SAP) is the most straightforward approach and is widely used in commercial products. This paper reviews the most important error sources of SAP, such as static focusing, delay quantization, linear delay profile, and coarse apodization, and the impacts introduced by these errors are shown. We propose to use main lobe coherence loss as a simple classification of the quality of the beam profile for a given design. This figure-ofmerit (FoM) is evaluated by simulations with a 1-D ultrasound subaperture array setup. The analytical expressions and the coherence loss can work as a quick guideline in subaperture design by equalizing the merit degradations from different error sources, as well as minimizing the average or maximum loss over ranges. For the evaluated 1-D array example, a good balance between errors and cost was achieved using a subaperture size of 5 elements, focus at 40 mm range, and a delay quantization step corresponding to a phase of π/4.

Published
2015
Full Text
View/download PDF

41. Inhibition of Notch signaling alters the phenotype of orthotopic tumors formed from glioblastoma multiforme neurosphere cells but does not hamper intracranial tumor growth regardless of endogene Notch pathway signature.

Author

Kristoffersen K, Nedergaard MK, Villingshøj M, Borup R, Broholm H, Kjær A, Poulsen HS, and Stockhausen MT

Subjects
Animals, Brain Neoplasms metabolism, Cell Survival, Dipeptides pharmacology, Female, Gene Expression, Glioblastoma metabolism, Heterografts, Humans, Mice, SCID, Neoplasm Transplantation, Neoplastic Stem Cells metabolism, Neoplastic Stem Cells pathology, Receptors, Notch antagonists & inhibitors, Signal Transduction, Brain Neoplasms pathology, Cell Proliferation drug effects, Glioblastoma pathology, Receptors, Notch metabolism
Abstract

Background: Brain cancer stem-like cells (bCSC) are cancer cells with neural stem cell (NSC)-like properties found in the devastating brain tumor glioblastoma multiforme (GBM). bCSC are proposed a central role in tumor initiation, progression, treatment resistance and relapse and as such present a promising target in GBM research. The Notch signaling pathway is often deregulated in GBM and we have previously characterized GBM-derived bCSC cultures based on their expression of the Notch-1 receptor and found that it could be used as predictive marker for the effect of Notch inhibition. The aim of the present project was therefore to further elucidate the significance of Notch pathway activity for the tumorigenic properties of GBM-derived bCSC., Methods: Human-derived GBM xenograft cells previously established as NSC-like neurosphere cultures were used. Notch inhibition was accomplished by exposing the cells to the gamma-secretase inhibitor DAPT prior to gene expression analysis and intracranial injection into immunocompromised mice., Results: By analyzing the expression of several Notch pathway components, we found that the cultures indeed displayed different Notch pathway signatures. However, when DAPT-treated neurosphere cells were injected into the brain of immunocompromised mice, no increase in survival was obtained regardless of Notch pathway signature and Notch inhibition. We did however observe a decrease in the expression of the stem cell marker Nestin, an increase in the proliferative marker Ki-67 and an increased number of abnormal vessels in tumors formed from DAPT-treated, high Notch-1 expressing cultures, when compared with the control., Conclusion: Based on the presented results we propose that Notch inhibition partly induces differentiation of bCSC, and selects for a cell type that more strongly induces angiogenesis if the treatment is not sustained. However, this more differentiated cell type might prove to be more sensitive to conventional therapies.

Published
2014
Full Text
View/download PDF

42. The use of longitudinal 18F-FET MicroPET imaging to evaluate response to irinotecan in orthotopic human glioblastoma multiforme xenografts.

Author

Nedergaard MK, Kristoffersen K, Michaelsen SR, Madsen J, Poulsen HS, Stockhausen MT, Lassen U, and Kjaer A

Subjects
Animals, Brain drug effects, Brain Neoplasms drug therapy, Camptothecin therapeutic use, Cell Line, Tumor, Female, Glioblastoma drug therapy, Heterografts, Humans, Irinotecan, Mice, Nude, Neuroimaging, Positron-Emission Tomography, Antineoplastic Agents, Phytogenic therapeutic use, Brain pathology, Brain Neoplasms diagnosis, Camptothecin analogs & derivatives, Glioblastoma diagnosis, Tyrosine analogs & derivatives
Abstract

Objectives: Brain tumor imaging is challenging. Although 18F-FET PET is widely used in the clinic, the value of 18F-FET MicroPET to evaluate brain tumors in xenograft has not been assessed to date. The aim of this study therefore was to evaluate the performance of in vivo 18F-FET MicroPET in detecting a treatment response in xenografts. In addition, the correlations between the 18F-FET tumor accumulation and the gene expression of Ki67 and the amino acid transporters LAT1 and LAT2 were investigated. Furthermore, Ki67, LAT1 and LAT2 gene expression in xenograft and archival patient tumors was compared., Methods: Human GBM cells were injected orthotopically in nude mice and 18F-FET uptake was followed by weekly MicroPET/CT. When tumor take was observed, mice were treated with CPT-11 or saline weekly. After two weeks of treatment the brain tumors were isolated and quantitative polymerase chain reaction were performed on the xenograft tumors and in parallel on archival patient tumor specimens., Results: The relative tumor-to-brain (T/B) ratio of SUV max was significantly lower after one week (123 ± 6%, n = 7 vs. 147 ± 6%, n = 7; p = 0.018) and after two weeks (142 ± 8%, n = 5 vs. 204 ± 27%, n = 4; p = 0.047) in the CPT-11 group compared with the control group. Strong negative correlations between SUV max T/B ratio and LAT1 (r = -0.62, p = 0.04) and LAT2 (r = -0.67, p = 0.02) were observed. In addition, a strong positive correlation between LAT1 and Ki67 was detected in xenografts. Furthermore, a 1.6 fold higher expression of LAT1 and a 23 fold higher expression of LAT2 were observed in patient specimens compared to xenografts., Conclusions: 18F-FET MicroPET can be used to detect a treatment response to CPT-11 in GBM xenografts. The strong negative correlation between SUV max T/B ratio and LAT1/LAT2 indicates an export transport function. We suggest that 18F-FET PET may be used for detection of early treatment response in patients.

Published
2014
Full Text
View/download PDF

43. Differentiation of glioblastoma multiforme stem-like cells leads to downregulation of EGFR and EGFRvIII and decreased tumorigenic and stem-like cell potential.

Author

Stockhausen MT, Kristoffersen K, Stobbe L, and Poulsen HS

Subjects
Animals, Brain Neoplasms genetics, Brain Neoplasms metabolism, Cell Differentiation drug effects, Cell Line, Tumor drug effects, Culture Media, Serum-Free, Down-Regulation, ErbB Receptors genetics, Glioblastoma genetics, Glioblastoma metabolism, Heterografts, Humans, Mice, Neoplastic Stem Cells metabolism, Neoplastic Stem Cells pathology, Tretinoin pharmacology, Brain Neoplasms pathology, ErbB Receptors metabolism, Glioblastoma pathology, Neoplastic Stem Cells drug effects
Abstract

Glioblastoma multiforme (GBM) is the most common and devastating primary brain tumor among adults. Despite recent treatment progress, most patients succumb to their disease within 2 years of diagnosis. Current research has highlighted the importance of a subpopulation of cells, assigned brain cancer stem-like cells (bCSC), to play a pivotal role in GBM malignancy. bCSC are identified by their resemblance to normal neural stem cells (NSC), and it is speculated that the bCSC have to be targeted in order to improve treatment outcome for GBM patients. One hallmark of GBM is aberrant expression and activation of the epidermal growth factor receptor (EGFR) and expression of a deletion variant EGFRvIII. In the normal brain, EGFR is expressed in neurogenic areas where also NSC are located and it has been shown that EGFR is involved in regulation of NSC proliferation, migration, and differentiation. This led us to speculate if EGFR and EGFRvIII are involved in the regulation of bCSC. In this study we use GBM neurosphere cultures, known to preserve bCSC features. We demonstrate that EGFR and EGFRvIII are downregulated upon differentiation and moreover that when EGFR signaling is abrogated, differentiation is induced. Furthermore, we show that differentiation leads to decreased tumorigenic and stem cell-like potential of the neurosphere cultures and that by specifically inhibiting EGFR signaling it is possible to target the bCSC population. Our results suggest that differentiation therapy, possibly along with anti-EGFR treatment would be a feasible treatment option for patients with GBM, by targeting the bCSC population.

Published
2014
Full Text
View/download PDF

44. Level of Notch activation determines the effect on growth and stem cell-like features in glioblastoma multiforme neurosphere cultures.

Author

Kristoffersen K, Villingshøj M, Poulsen HS, and Stockhausen MT

Subjects
Cell Differentiation physiology, Cell Growth Processes physiology, Cell Line, Tumor, Humans, Signal Transduction, Brain Neoplasms metabolism, Brain Neoplasms pathology, Glioblastoma metabolism, Glioblastoma pathology, Neoplastic Stem Cells metabolism, Neoplastic Stem Cells pathology, Receptors, Notch metabolism
Abstract

Background: Brain cancer stem-like cells (bCSC) are cancer cells with neural stem cell (NSC)-like properties found in glioblastoma multiforme (GBM) and they are assigned a central role in tumor initiation, progression and relapse. The Notch pathway is important for maintenance and cell fate decisions in the normal NSC population. Notch signaling is often deregulated in GBM and recent results suggest that this pathway plays a significant role in bCSC as well. We therefore wished to further elucidate the role of Notch activation in GBM-derived bCSC., Methods: Human-derived GBM xenograft cells were cultured as NSC-like neurosphere cultures. Notch modulation was accomplished either by blocking the pathway using the γ-secretase inhibitor DAPT or by activating it by transfecting the cells with the constitutive active Notch-1 receptor., Results: GBM neurosphere cultures with high endogenous Notch activation displayed sensitivity toward Notch inhibition with regard to tumorigenic features as demonstrated by increased G0/G1 population and reduced colony formation capacity. Of the NSC-like characteristics, only the primary sphere forming potential was affected, while no effect was observed on self-renewal or differentiation. In contrast, when Notch signaling was activated a decrease in the G0/G1 population and an enhanced capability of colony formation was observed, along with increased self-renewal and de-differentiation., Conclusion: Based on the presented results we propose that active Notch signaling plays a role for cell growth and stem cell-like features in GBM neurosphere cultures and that Notch-targeted anti-bCSC treatment could be feasible for GBM patients with high endogenous Notch pathway activation.

Published
2013
Full Text
View/download PDF

45. How can movement quality be promoted in clinical practice? A phenomenological study of physical therapist experts.

Author

Skjaerven LH, Kristoffersen K, and Gard G

Subjects
Adult, Aged, Female, Humans, Interviews as Topic, Male, Middle Aged, Psychomotor Performance, Awareness, Clinical Competence, Health Promotion methods, Movement physiology, Physical Therapy Modalities standards, Physical Therapy Specialty methods
Abstract

Background: In recent years, physical therapists have paid greater attention to body awareness. Clinicians have witnessed the benefits of supporting their patients' learning of movement awareness through the promotion of their movement quality., Objective: The aim of this study was to investigate how physical therapist experts promote movement quality in their usual clinical settings., Design: A phenomenological research design that included a sampling strategy was devised. Using specific criteria, 6 lead physical therapists nominated a group of physical therapist experts from the fields of neurology, primary health care, and mental health. Fifteen informants, 5 from each field, agreed to participate., Methods: In-depth interviews were conducted with a semistructured interview guide. The informants were invited to simply describe what they had experienced to be successful therapeutic processes for promoting movement quality. Each interview was audiotaped and transcribed. The data analysis was based on a multistep model., Results: Three main themes emerged from the data. First, the physical therapists' embodied presence and movement awareness served as a precondition and an orientation for practice. Embodied presence is a bodily felt sense, a form of personal knowing that evokes understanding and fosters meaning. Second, creating a platform for promoting movement quality revealed implementation of psychological attitudes. Third, action strategies for promoting movement quality suggested a movement awareness learning cycle and components for clinical use., Conclusions: This study demonstrated specific attitudes and skills used by physical therapist experts to promote movement quality in their clinical practice. These results may serve as a therapeutic framework for promoting movement quality in clinical physical therapy, although further research is needed.

Published
2010
Full Text
View/download PDF

46. The functional role of Notch signaling in human gliomas.

Author

Stockhausen MT, Kristoffersen K, and Poulsen HS

Subjects
Humans, Brain Neoplasms metabolism, Glioma metabolism, Neoplastic Stem Cells metabolism, Receptors, Notch metabolism, Signal Transduction physiology
Abstract

Gliomas are among the most devastating adult tumors for which there is currently no cure. The tumors are derived from brain glial tissue and comprise several diverse tumor forms and grades. Recent reports highlight the importance of cancer-initiating cells in the malignancy of gliomas. These cells have been referred to as brain cancer stem cells (bCSC), as they share similarities to normal neural stem cells in the brain. The Notch signaling pathway is involved in cell fate decisions throughout normal development and in stem cell proliferation and maintenance. The role of Notch in cancer is now firmly established, and recent data implicate a role for Notch signaling also in gliomas and bCSC. In this review, we explore the role of the Notch signaling pathway in gliomas with emphasis on its role in normal brain development and its interplay with pathways and processes that are characteristic of malignant gliomas.

Published
2010
Full Text
View/download PDF

47. Sense of coherence predicts change in life satisfaction among home-living residents in the community with mental health problems: a 1-year follow-up study.

Author

Langeland E, Wahl AK, Kristoffersen K, Nortvedt MW, and Hanestad BR

Subjects
Adolescent, Adult, Aged, Aged, 80 and over, Chronic Disease, Community Mental Health Services, Family Characteristics, Female, Follow-Up Studies, Humans, Male, Middle Aged, Norway, Prognosis, Psychiatric Status Rating Scales, Regression Analysis, Self-Assessment, Severity of Illness Index, Urban Health, Adaptation, Psychological, Mental Disorders psychology, Personal Satisfaction, Self Efficacy, Sickness Impact Profile
Abstract

Objectives: There is a call for a further investigation of Sense of Coherence (SOC), the central concept in salutogenesis, and its relation to health and life satisfaction. No previous studies have investigated the utility of SOC versus mental symptoms for the prediction of life satisfaction among people with chronic mental health problems (MHP)., Methods: The present study has a prospective design including a baseline assessment and a 1-year follow up. We recruited 107 adults from the community health care system. SOC was measured by the Sense of Coherence questionnaire, mental symptoms by the Symptom Checklist-90 revised and life satisfaction by The Quality of Life Scale (all Norwegian versions)., Results: The results show that while SOC predicts change in life satisfaction (standardized beta coefficient for SOC was 0.39, P = 0.014), mental symptoms did not (standardized beta coefficient 0.00, P = 1.0)., Conclusions: These findings emphasize the importance of assessing factors that may explain differences in life satisfaction over and above mental symptoms among people with MHP. The results indicate that improving SOC among people with MHP might provide important opportunities for improving their life satisfaction.

Published
2007
Full Text
View/download PDF

48. Parallel beamforming using synthetic transmit beams.

Author

Hergum T, Bjåstad T, Kristoffersen K, and Torp H

Subjects
Computer Simulation, Radiation Dosage, Scattering, Radiation, Image Interpretation, Computer-Assisted methods, Models, Biological, Radiometry methods, Ultrasonography methods
Abstract

Parallel beamforming is frequently used to increase the acquisition rate of medical ultrasound imaging. However, such imaging systems will not be spatially shift invariant due to significant variation across adjacent beams. This paper investigates a few methods of parallel beam-forming that aims at eliminating this flaw and restoring the shift invariance property. The beam-to-beam variations occur because the transmit and receive beams are not aligned. The underlying idea of the main method presented here is to generate additional synthetic transmit beams (STB) through interpolation of the received, unfocused signal at each array element prior to beamforming. Now each of the parallel receive beams can be aligned perfectly with a transmit beam--synthetic or real--thus eliminating the distortion caused by misalignment. The proposed method was compared to the other compensation methods through a simulation study based on the ultrasound simulation software Field II. The results have been verified with in vitro experiments. The simulations were done with parameters similar to a standard cardiac examination with two parallel receive beams and a transmit-line spacing corresponding to the Rayleigh criterion, wavelength times f-number (lambda x f#). From the results presented, it is clear that straightforward parallel beamforming reduces the spatial shift invariance property of an ultrasound imaging system. The proposed method of using synthetic transmit beams seems to restore this important property, enabling higher acquisition rates without loss of image quality.

Published
2007
Full Text
View/download PDF

Catalog

Books, media, physical & digital resources
See catalog results