90 results on '"Markmann M"'
Search Results
2. Spatially resolved spectroscopy on single self-assembled quantum dots
- Author
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Zrenner, A., Markmann, M., Beham, E., Findeis, F., Böhm, G., and Abstreiter, G.
- Published
- 1999
- Full Text
- View/download PDF
3. Does heart surgery change the capacity of α1-antitrypsin to inhibit the ATP-induced release of monocytic interleukin-1β? A preliminary study
- Author
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Agné, A., primary, Richter, K., additional, Tumpara, S., additional, Sauer, A.-L., additional, Beckert, F., additional, Wrenger, S., additional, Zakrzewicz, A., additional, Hecker, A., additional, Markmann, M., additional, Koch, C., additional, Zajonz, T., additional, Sander, M., additional, Böning, A., additional, Padberg, W., additional, Janciauskiene, S., additional, and Grau, V., additional
- Published
- 2020
- Full Text
- View/download PDF
4. Optimisation of Perioperative Cardiovascular Management to Improve Surgical Outcome II (OPTIMISE II) trial: study protocol for a multicentre international trial of cardiac output-guided fluid therapy with low-dose inotrope infusion compared with usual care in patients undergoing major elective gastrointestinal surgery
- Author
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Edwards M, Forbes G, Berdunov V, Mihaylova B, Dias P, Thomson A, Grocott M, Mythen M, Gillies M, Phan T, Evered L, Wijeysundera D, McCluskey S, Hofer C, Abukhudair H, Szczeklik W, Hajjar L, Kahan B, Pearse R, MacDonald N, Abbott T, Martin T, Januszewska M, Niebrzegowska E, Bekele S, Pates K, Haines R, Walker S, Fowler A, Oliveira M, Whalley J, Stephens T, Amaral V, May S, Manou V, Jones T, Dunkley S, Pakats M, Griffiths B, Fernandez M, Jonas M, Bolger C, Collings N, Burnish R, Kelleher M, Dawson H, Lang A, Campbell R, Rea N, Clark S, Blunt M, Rosbergen M, Hodgson R, Wittenberg M, Filipe H, Gleeson Y, Pakou G, Szakmany T, Gunter U, Hodkinson G, Reay M, Gidda R, Allcock C, Cole A, Watts A, Gardner W, Tindall M, Anumakonda V, Agarwal N, Price T, Clark P, Thompson R, Fowler S, Gray K, McGregor A, Smith T, Wilson T, Guha A, Hodgson A, McSkeane A, Barberis L, Mohamed M, Prentice S, Saunders Z, Ratnam V, Pawa N, Sayan A, Thankachen M, Svensson M, Raj A, Ahmad N, Ivermee C, Cashman J, Smee E, Kanapeckaite L, Corcoran P, Fitzgerald E, Peyton P, Buckley A, Baulch S, Claxton G, Harris S, Sidiropolous S, de Almeida J, Simoes C, Galas F, Camara L, Malbouisson L, Soares S, Fernandes C, Joaquim E, Stefani L, Falcao L, Salgado M, Guimaraes G, Gomes M, Lineburger E, Navarro L, Salles L, Azi L, Prado R, Benedetti R, de Godoy E, Bastos F, da Silva R, dos Santos W, Pazmino-Canizares J, Parotto M, Wasowicz M, Beattie S, Meineri M, Clarke H, Ladha K, Jerath A, Ayach N, Poonawala H, Sellers D, Duncan D, Carroll J, Hudson C, van Vlymen J, Jaeger M, Shelley J, Shore D, McQuaide S, Richebe P, Godin N, Gobert Q, Fortier L, Verdonck O, Sato H, Schricker T, Codere-Maruyama T, Lattermann R, Hatzakorzian R, Moore A, Sato T, Funk D, Kowalski S, Girling L, Monterola M, Fidler K, Sander M, Markmann M, Schulte D, Singer R, Koch C, Ruhrmann S, Habig L, Edinger F, Schneck E, Treskatsch S, Ertmer M, Trauzeddel R, Weyland A, Diers A, Grote T, Pabel S, Lipka A, Nannen L, Fleischer A, Wittmann M, Winkler A, Neumann C, Fingerhut M, Ehrentraut H, Guttenthaler V, Heringlake M, Brandt S, Olsson S, Schmidt C, Schemke S, Murat L, Abu Khudair H, Farhoud E, Ghidan A, Al Masri M, Abu Kwiak S, Abdel-Nabi H, Grigoras I, Ristescu I, Jitaru I, Manole M, Rusu D, Gata A, Aldecoa C, Gonzalez A, Alfonso S, Perz L, Feijoo J, Guerra Y, Herrero A, Ripolles-Melchor J, Abad-Motos A, de Pablo E, Martinez-Hurtado E, Abad-Gurumeta A, Salvachua-Fernandez R, Nozal-Mateo B, de Nadal M, Galan P, Visauta E, Peral E, Da Prat I, Suarez S, Peral C, Una-Orejon R, Caldera-Alvarez M, Fernandez-Francos S, Davila A, Ortola C, Gutierrez A, Mugarra A, Romero E, Soro M, Gracia E, Pozo N, Villafane A, Diez A, Sanchez C, Buron F, Blanco R, Duran M, Parada P, Torres M, Rivas M, Brage S, Castro A, Conde M, Pardal C, Ben M, Perez A, Sancho J, Alarcon M, Mariotti S, Marcolino I, Winter A, McGrane T, Craven D, Turnbo T, Mayo G, Campbell D, Klintworth S, Tilley A, Weinstein M, Horan A, Chowdary R, Carlon V, Balasinorwala T, Yang G, and OPTIMISE II Investigators
- Published
- 2019
5. Optimisation of Perioperative Cardiovascular Management to Improve Surgical Outcome II (OPTIMISE II) trial: study protocol for a multicentre international trial of cardiac output-guided fluid therapy with low-dose inotrope infusion compared with usual care in patients undergoing major elective gastrointestinal surgery
- Author
-
Edwards, MR, Forbes, G, MacDonald, N, Berdunov, V, Mihaylova, B, Dias, P, Thomson, A, Grocott, MPW, Mythen, MG, Gillies, MA, Sander, M, Phan, TD, Evered, L, Wijeysundera, DN, McCluskey, SA, Aldecoa, C, Ripolles-Melchor, J, Hofer, CK, Abukhudair, H, Szczeklik, W, Grigoras, I, Hajjar, LA, Kahan, BC, Pearse, RM, Abbott, T, Martin, T, Januszewska, M, Niebrzegowska, E, Bekele, S, Pates, K, Haines, R, Walker, S, Fowler, A, Oliveira, M, Whalley, J, Stephens, T, Amaral, VDS, May, S, Manou, V, Jones, T, Dunkley, S, Pakats, M-L, Griffiths, B, Fernandez, M, Edwards, M, Jonas, M, Bolger, C, Collings, N, Burnish, R, Kelleher, M, Dawson, H, Lang, A, Campbell, R, Rea, N, Clark, S, Blunt, M, Rosbergen, M, Hodgson, R, Wittenberg, M, Filipe, H, Gleeson, Y, Pakou, G, Szakmany, T, Gunter, U, Hodkinson, G, Reay, M, Gidda, R, Allcock, C, Cole, A, Watts, A, Gardner, W, Tindall, M, Anumakonda, V, Agarwal, N, Price, T, Clark, P, Thompson, R, Fowler, S, Gray, K, McGregor, A, Smith, T, Wilson, T, Guha, A, Hodgson, A, McSkeane, A, Barberis, L, Mohamed, M, Prentice, S, Saunders, Z, Ratnam, V, Pawa, N, Sayan, A, Thankachen, M, Svensson, M-L, Raj, A, Ahmad, N, Ivermee, C, Cashman, J, Smee, E, Kanapeckaite, L, Tuong, P, Corcoran, P, Fitzgerald, E, Peyton, P, Buckley, A, Baulch, S, Claxton, G, Harris, S, Sidiropolous, S, de Almeida, JP, Simoes, C, Galas, FRBG, Camara, L, Malbouisson, LMS, Soares, SD, Fernandes, CR, Joaquim, EHG, Stefani, LC, Falcao, LF, Salgado, M, Guimaraes, GN, Gomes, MDA, Lineburger, E, Navarro, L, Salles, LC, Azi, LMTDA, Prado, RG, Benedetti, RH, de Godoy, EP, Bastos, FA, da Silva, RJC, dos Santos, WF, McCluskey, S, Wijeysundera, D, Pazmino-Canizares, J, Parotto, M, Wasowicz, M, Beattie, S, Meineri, M, Clarke, H, Ladha, K, Jerath, A, Ayach, N, Poonawala, H, Sellers, D, Duncan, D, Carroll, J, Hudson, C, van Vlymen, J, Jaeger, M, Shelley, J, Shore, DD, McQuaide, S, Richebe, P, Godin, N, Gobert, Q, Fortier, LP, Verdonck, O, Sato, H, Schricker, T, Codere-Maruyama, T, Lattermann, R, Hatzakorzian, R, Moore, A, Sato, T, Funk, D, Kowalski, S, Girling, L, Monterola, M, Fidler, K, Markmann, M, Schulte, D, Singer, R, Koch, C, Ruhrmann, S, Habig, L, Edinger, F, Schneck, E, Treskatsch, S, Ertmer, M, Trauzeddel, R-F, Weyland, A, Diers, A, Grote, T, Pabel, S, Lipka, A, Nannen, L, Fleischer, A, Wittmann, M, Winkler, A, Neumann, C, Fingerhut, M-L, Ehrentraut, H, Guttenthaler, V, Heringlake, M, Brandt, S, Olsson, S, Schmidt, C, Schemke, S, Murat, L, Abu Khudair, H, Farhoud, E, Ghidan, A, Al Masri, M, Abu Kwiak, S, Abdel-Nabi, H, Ristescu, I, Jitaru, I, Manole, M, Rusu, D, Gata, A, Gonzalez, AP, Alfonso, SM, Perz, LV, Feijoo, JR, Guerra, Y, Herrero, A, Abad-Motos, A, de Pablo, EL, Martinez-Hurtado, E, Abad-Gurumeta, A, Salvachua-Fernandez, R, Nozal-Mateo, B, de Nadal, M, Galan, P, Visauta, EC, Peral, EC, Da Prat, IC, Suarez, SG, Peral, C, Una-Orejon, R, Caldera-Alvarez, MV, Fernandez-Francos, S, Davila, AS, Ortola, CF, Gutierrez, A, Mugarra, A, Romero, E, Soro, M, Gracia, E, Pozo, N, Villafane, AP, Diez, AF, Sanchez, CGM, Buron, FD, Blanco, RP, Duran, MV, Parada, PD, Torres, MB, Rivas, MC, Brage, SM, Castro, AMG, Conde, MJP, Pardal, CB, Ben, MRT, Perez, A, Sancho, JM, Alarcon, MM, Hofer, C, Mariotti, S, Marcolino, I, Winter, A, McGrane, T, Craven, D, Turnbo, T, Mayo, G, Campbell, D, Klintworth, S, Tilley, A, Weinstein, M, Horan, A, Chowdary, R, Carlon, VA, Balasinorwala, T, Yang, G, Edwards, MR, Forbes, G, MacDonald, N, Berdunov, V, Mihaylova, B, Dias, P, Thomson, A, Grocott, MPW, Mythen, MG, Gillies, MA, Sander, M, Phan, TD, Evered, L, Wijeysundera, DN, McCluskey, SA, Aldecoa, C, Ripolles-Melchor, J, Hofer, CK, Abukhudair, H, Szczeklik, W, Grigoras, I, Hajjar, LA, Kahan, BC, Pearse, RM, Abbott, T, Martin, T, Januszewska, M, Niebrzegowska, E, Bekele, S, Pates, K, Haines, R, Walker, S, Fowler, A, Oliveira, M, Whalley, J, Stephens, T, Amaral, VDS, May, S, Manou, V, Jones, T, Dunkley, S, Pakats, M-L, Griffiths, B, Fernandez, M, Edwards, M, Jonas, M, Bolger, C, Collings, N, Burnish, R, Kelleher, M, Dawson, H, Lang, A, Campbell, R, Rea, N, Clark, S, Blunt, M, Rosbergen, M, Hodgson, R, Wittenberg, M, Filipe, H, Gleeson, Y, Pakou, G, Szakmany, T, Gunter, U, Hodkinson, G, Reay, M, Gidda, R, Allcock, C, Cole, A, Watts, A, Gardner, W, Tindall, M, Anumakonda, V, Agarwal, N, Price, T, Clark, P, Thompson, R, Fowler, S, Gray, K, McGregor, A, Smith, T, Wilson, T, Guha, A, Hodgson, A, McSkeane, A, Barberis, L, Mohamed, M, Prentice, S, Saunders, Z, Ratnam, V, Pawa, N, Sayan, A, Thankachen, M, Svensson, M-L, Raj, A, Ahmad, N, Ivermee, C, Cashman, J, Smee, E, Kanapeckaite, L, Tuong, P, Corcoran, P, Fitzgerald, E, Peyton, P, Buckley, A, Baulch, S, Claxton, G, Harris, S, Sidiropolous, S, de Almeida, JP, Simoes, C, Galas, FRBG, Camara, L, Malbouisson, LMS, Soares, SD, Fernandes, CR, Joaquim, EHG, Stefani, LC, Falcao, LF, Salgado, M, Guimaraes, GN, Gomes, MDA, Lineburger, E, Navarro, L, Salles, LC, Azi, LMTDA, Prado, RG, Benedetti, RH, de Godoy, EP, Bastos, FA, da Silva, RJC, dos Santos, WF, McCluskey, S, Wijeysundera, D, Pazmino-Canizares, J, Parotto, M, Wasowicz, M, Beattie, S, Meineri, M, Clarke, H, Ladha, K, Jerath, A, Ayach, N, Poonawala, H, Sellers, D, Duncan, D, Carroll, J, Hudson, C, van Vlymen, J, Jaeger, M, Shelley, J, Shore, DD, McQuaide, S, Richebe, P, Godin, N, Gobert, Q, Fortier, LP, Verdonck, O, Sato, H, Schricker, T, Codere-Maruyama, T, Lattermann, R, Hatzakorzian, R, Moore, A, Sato, T, Funk, D, Kowalski, S, Girling, L, Monterola, M, Fidler, K, Markmann, M, Schulte, D, Singer, R, Koch, C, Ruhrmann, S, Habig, L, Edinger, F, Schneck, E, Treskatsch, S, Ertmer, M, Trauzeddel, R-F, Weyland, A, Diers, A, Grote, T, Pabel, S, Lipka, A, Nannen, L, Fleischer, A, Wittmann, M, Winkler, A, Neumann, C, Fingerhut, M-L, Ehrentraut, H, Guttenthaler, V, Heringlake, M, Brandt, S, Olsson, S, Schmidt, C, Schemke, S, Murat, L, Abu Khudair, H, Farhoud, E, Ghidan, A, Al Masri, M, Abu Kwiak, S, Abdel-Nabi, H, Ristescu, I, Jitaru, I, Manole, M, Rusu, D, Gata, A, Gonzalez, AP, Alfonso, SM, Perz, LV, Feijoo, JR, Guerra, Y, Herrero, A, Abad-Motos, A, de Pablo, EL, Martinez-Hurtado, E, Abad-Gurumeta, A, Salvachua-Fernandez, R, Nozal-Mateo, B, de Nadal, M, Galan, P, Visauta, EC, Peral, EC, Da Prat, IC, Suarez, SG, Peral, C, Una-Orejon, R, Caldera-Alvarez, MV, Fernandez-Francos, S, Davila, AS, Ortola, CF, Gutierrez, A, Mugarra, A, Romero, E, Soro, M, Gracia, E, Pozo, N, Villafane, AP, Diez, AF, Sanchez, CGM, Buron, FD, Blanco, RP, Duran, MV, Parada, PD, Torres, MB, Rivas, MC, Brage, SM, Castro, AMG, Conde, MJP, Pardal, CB, Ben, MRT, Perez, A, Sancho, JM, Alarcon, MM, Hofer, C, Mariotti, S, Marcolino, I, Winter, A, McGrane, T, Craven, D, Turnbo, T, Mayo, G, Campbell, D, Klintworth, S, Tilley, A, Weinstein, M, Horan, A, Chowdary, R, Carlon, VA, Balasinorwala, T, and Yang, G
- Abstract
INTRODUCTION: Postoperative morbidity and mortality in older patients with comorbidities undergoing gastrointestinal surgery are a major burden on healthcare systems. Infections after surgery are common in such patients, prolonging hospitalisation and reducing postoperative short-term and long-term survival. Optimal management of perioperative intravenous fluids and inotropic drugs may reduce infection rates and improve outcomes from surgery. Previous small trials of cardiac-output-guided haemodynamic therapy algorithms suggested a modest reduction in postoperative morbidity. A large definitive trial is needed to confirm or refute this and inform widespread clinical practice. METHODS: The Optimisation of Perioperative Cardiovascular Management to Improve Surgical Outcome II (OPTIMISE II) trial is a multicentre, international, parallel group, open, randomised controlled trial. 2502 high-risk patients undergoing major elective gastrointestinal surgery will be randomly allocated in a 1:1 ratio using minimisation to minimally invasive cardiac output monitoring to guide protocolised administration of intravenous fluid combined with low-dose inotrope infusion, or usual care. The trial intervention will be carried out during and for 4 hours after surgery. The primary outcome is postoperative infection of Clavien-Dindo grade II or higher within 30 days of randomisation. Participants and those delivering the intervention will not be blinded to treatment allocation; however, outcome assessors will be blinded when feasible. Participant recruitment started in January 2017 and is scheduled to last 3 years, within 50 hospitals worldwide. ETHICS/DISSEMINATION: The OPTIMISE II trial has been approved by the UK National Research Ethics Service and has been approved by responsible ethics committees in all participating countries. The findings will be disseminated through publication in a widely accessible peer-reviewed scientific journal. TRIAL REGISTRATION NUMBER: ISRCTN39653756.
- Published
- 2019
6. Silicon/silicon suboxide heterostructures grown by molecular beam epitaxy
- Author
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Sticht, A, Markmann, M, Brunner, K, Abstreiter, G, and Müller, E
- Published
- 2002
- Full Text
- View/download PDF
7. Electron and hole impact excitation of Er in MBE grown Si:O and Si 1− yC y diodes
- Author
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Markmann, M., Neumann, R., Brunner, K., and Abstreiter, G.
- Published
- 2001
- Full Text
- View/download PDF
8. Time dependant effects of mechanical ventilation and hyperoxia on central signalling pathways in the developing lung identified by comprehensive transcriptome analysis
- Author
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Hilgendorff, A., Pritzke, T., Markmann, M., Oak, P., Koschlig, M., Hossain, H., and Desai, T.
- Published
- 2017
9. Photoluminescence characterization of erbium doped Si1−yCy alloys grown by MBE
- Author
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Markmann, M, Neufeld, E, Brunner, K, Abstreiter, G, and Buchal, Ch
- Published
- 2000
- Full Text
- View/download PDF
10. Multi-exciton spectroscopy on a self-assembled InGaAs[formula omitted]GaAs quantum dot
- Author
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Findeis, F., Zrenner, A., Markmann, M., Böhm, G., and Abstreiter, G.
- Published
- 2000
- Full Text
- View/download PDF
11. Efficient light emission at 1.54 μm from Er in Si excited by hot electron injection through thin suboxide layers.
- Author
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Markmann, M., Sticht, A., Bobe, F., Zandler, G., Brunner, K., Abstreiter, G., and Mu¨ller, E.
- Subjects
- *
SILICON diodes , *ELECTROLUMINESCENCE , *ELECTRONICS - Abstract
We studied the electroluminescence of Er:O-doped Si pn diodes and unipolar structures with thin SiO[sub 1.6] suboxide barriers, which were deposited by molecular-beam epitaxy. These suboxide layers reveal a barrier height of about 320 meV in the conduction band and therefore raise the average kinetic energy of electrons injected through the barrier into the Er:O doped region. These electrons turn out to be advantageous for impact excitation processes with the erbium ion. Compared to conventional reverse biased pn diodes a ten-times higher o-r product for impact excitation (1.2 × 10[sup -19]cm²s) can be achieved in pn diodes with a suboxide injector at 10 K. The saturation electroluminescence (EL) intensity is enlarged in reverse bias and suppressed in forward bias compared to a diode without a suboxide layer. These structures exhibit a reduction of the EL intensity by a factor of 3 for increasing temperature from 10 to 300 K and yield a two-times higher EL output at 1.54 µm and 300 K than an optimized reverse biased pn diode without a suboxide layer. At 300 K this results in an absolute output power of 250 nW and an external quantum efficiency of 1.3 × 10[sup -4] at 1.54 µm. For the unipolar structure with an integrated suboxide barrier the EL output also depends on the current flow direction: Injecting the electrons hot through the suboxide barrier into the Er:O doped region results in a six times higher EL intensity at 1.54 µm than for the opposite biasing condition. The EL is detectable up to 300 K with a reduction of the intensity by a factor of 8 between 10 and 300 K. Monte Carlo simulations were performed on unipolar structures with an incorporated barrier to provide insight into the carrier density and carrier energy distribution after injection through the barrier. [ABSTRACT FROM AUTHOR]
- Published
- 2002
- Full Text
- View/download PDF
12. Transfection of Sertoli cells with androgen receptor alters gene expression without androgen stimulation
- Author
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Fietz, D., Markmann, M., Lang, D., Konrad, L., Geyer, J., Kliesch, S., Chakraborty, T., Hossain, H., Bergmann, M., and Institute of Veterinary Anatomy, Histology and Embryology
- Subjects
Male ,animal structures ,viruses ,sertoli cells ,Gene Expression ,Transfection ,Cell Line ,Mice ,Gene expression analysis ,androgen receptor ,Animals ,Humans ,ddc:630 ,RNA, Messenger ,Molecular Biology ,Sertoli Cells ,gene expression analysis ,Gene Expression Profiling ,fungi ,Prostatic Neoplasms ,Agriculture ,Rats ,Androgen receptor ,Gene Expression Regulation ,transfection ,Receptors, Androgen ,embryonic structures ,Androgens ,Research Article - Abstract
Background Androgens play an important role for the development of male fertility and gained interest as growth and survival factors for certain types of cancer. Androgens act via the androgen receptor (AR/Ar), which is involved in various cell biological processes such as sex differentiation. To study the functional mechanisms of androgen action, cell culture systems and AR-transfected cell lines are needed. Transfection of AR into cell lines and subsequent gene expression analysis after androgen treatment is well established to investigate the molecular biology of target cells. However, it remains unclear how the transfection with AR itself can modulate the gene expression even without androgen stimulation. Therefore, we transfected Ar-deficient rat Sertoli cells 93RS2 by electroporation using a full length human AR. Results Transfection success was confirmed by Western Blotting, immunofluorescence and RT-PCR. AR transfection-related gene expression alterations were detected with microarray-based genome-wide expression profiling of transfected and non-transfected 93RS2 cells without androgen stimulation. Microarray analysis revealed 672 differentially regulated genes with 200 up- and 472 down-regulated genes. These genes could be assigned to four major biological categories (development, hormone response, immune response and metabolism). Microarray results were confirmed by quantitative RT-PCR analysis for 22 candidate genes. Conclusion We conclude from our data, that the transfection of Ar-deficient Sertoli cells with AR has a measurable effect on gene expression even without androgen stimulation and cause Sertoli cell damage. Studies using AR-transfected cells, subsequently stimulated, should consider alterations in AR-dependent gene expression as off-target effects of the AR transfection itself. Electronic supplementary material The online version of this article (doi:10.1186/s12867-015-0051-7) contains supplementary material, which is available to authorized users.
- Published
- 2015
13. Transfection of Sertoli cells with androgen receptor alters gene expression without androgen stimulation
- Author
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Fietz, Daniela, Markmann, M., Lang, D., Konrad, L., Geyer, J., Kliesch, S., Chakraborty, Trinad, Hossain, Hamid, Bergmann, M., and Justus Liebig University Giessen
- Subjects
transfection ,gene expression analysis ,androgen receptor ,sertoli cells ,ddc:630 - Abstract
Background: Androgens play an important role for the development of male fertility and gained interest as growth and survival factors for certain types of cancer. Androgens act via the androgen receptor (AR/Ar), which is involved in various cell biological processes such as sex differentiation. To study the functional mechanisms of androgen action, cell culture systems and AR-transfected cell lines are needed. Transfection of AR into cell lines and subsequent gene expression analysis after androgen treatment is well established to investigate the molecular biology of target cells. However, it remains unclear how the transfection with AR itself can modulate the gene expression even without androgen stimulation. Therefore, we transfected Ar-deficient rat Sertoli cells 93RS2 by electroporation using a full length human AR. Results: Transfection success was confirmed by Western Blotting, immunofluorescence and RT-PCR. AR transfection-related gene expression alterations were detected with microarray-based genome-wide expression profiling of transfected and non-transfected 93RS2 cells without androgen stimulation. Microarray analysis revealed 672 differentially regulated genes with 200 up- and 472 down-regulated genes. These genes could be assigned to four major biological categories (development, hormone response, immune response and metabolism). Microarray results were confirmed by quantitative RT-PCR analysis for 22 candidate genes. Conclusion: We conclude from our data, that the transfection of Ar-deficient Sertoli cells with AR has a measurable effect on gene expression even without androgen stimulation and cause Sertoli cell damage. Studies using AR-transfected cells, subsequently stimulated, should consider alterations in AR-dependent gene expression as off-target effects of the AR transfection itself.
- Published
- 2015
- Full Text
- View/download PDF
14. Efficient light emission at 1.54 muem from Er in Si excited by hot electron injection through thin suboxide layers
- Author
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Markmann, M., Sticht, A., Bobe, F., Zandler, G., Brunner, K., Abstreiter, G., and Muller, E.
- Subjects
Electrons -- Structure ,Electrons -- Research ,Thin films -- Structure ,Thin films -- Research ,Dielectric films -- Structure ,Dielectric films -- Research ,Diodes -- Research ,Physics - Abstract
A study was conducted to examine the electroluminescence of Er:O-doped Si pn diodes and unipolar structures with thin SiO(sub 1.6) suboxide barriers, which were deposited by molecular-beam epitaxy. The result confirms that electrons that are injected through thin suboxide layers turn out to be very efficient in the impact excitation of erbium ions.
- Published
- 2002
15. Transfection of Sertoli cells with androgen receptor alters gene expression without androgen stimulation
- Author
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Fietz, D., primary, Markmann, M., additional, Lang, D., additional, Konrad, L., additional, Geyer, J., additional, Kliesch, S., additional, Chakraborty, T., additional, Hossain, H., additional, and Bergmann, M., additional
- Published
- 2015
- Full Text
- View/download PDF
16. Tracing the Evolution of the Galápagos Iguanas: A Molecular Approach
- Author
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Rassmann, K., Markmann, M., Tautz, D., Trillmich, Fritz, Alberts, AC, Carter, RL, Hayes, WK, and Martins, EP
- Published
- 2004
17. Thin SiOx layers embedded in single crystalline silicon
- Author
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Sticht, A., primary, Markmann, M., additional, Brunner, K., additional, and Abstreiter, G., additional
- Published
- 2002
- Full Text
- View/download PDF
18. Electron and hole impact excitation of Er in MBE grown Si:O and Si1−yCy diodes
- Author
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Markmann, M., primary, Neumann, R., additional, Brunner, K., additional, and Abstreiter, G., additional
- Published
- 2001
- Full Text
- View/download PDF
19. Excitation efficiency of electrons and holes in forward and reverse biased epitaxially grown Er-doped Si diodes
- Author
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Markmann, M., primary, Neufeld, E., additional, Sticht, A., additional, Brunner, K., additional, and Abstreiter, G., additional
- Published
- 2001
- Full Text
- View/download PDF
20. Photoluminescence characterization of erbium doped Si 1−y C y alloys grown by MBE
- Author
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Markmann, M, primary, Neufeld, E, additional, Brunner, K, additional, Abstreiter, G, additional, and Buchal, Ch, additional
- Published
- 2000
- Full Text
- View/download PDF
21. Multi-exciton spectroscopy on a self-assembled InGaAs/GaAs quantum dot
- Author
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Findeis, F., primary, Zrenner, A., additional, Markmann, M., additional, Böhm, G., additional, and Abstreiter, G., additional
- Published
- 2000
- Full Text
- View/download PDF
22. Enhancement of erbium photoluminescence by substitutional C alloying of Si
- Author
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Markmann, M., primary, Neufeld, E., additional, Sticht, A., additional, Brunner, K., additional, Abstreiter, G., additional, and Buchal, Ch., additional
- Published
- 1999
- Full Text
- View/download PDF
23. Optimization of erbium-doped light-emitting diodes by p-type counterdoping
- Author
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Neufeld, E., primary, Markmann, M., additional, Vörckel, A., additional, Brunner, K., additional, and Abstreiter, G., additional
- Published
- 1999
- Full Text
- View/download PDF
24. Spatially resolved magneto-optics on confined systems
- Author
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Zrenner, A., primary, Markmann, M., additional, Paassen, A., additional, Efros, A.L., additional, Bichler, M., additional, Wegscheider, W., additional, Böhm, G., additional, and Abstreiter, G., additional
- Published
- 1998
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25. Spatially resolved optical spectroscopy on natural quantum dots
- Author
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Zrenner, A., primary, Schaller, A., additional, Markmann, M., additional, Hagn, M., additional, Arzberger, M., additional, Henry, D., additional, Abstreiter, G., additional, Böhm, G., additional, and Weimann, G., additional
- Published
- 1998
- Full Text
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26. STM-Cathodoluminescence of Self-Assembled InGaAs Quantum Dots
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Markmann, M., primary, Zrenner, A., additional, Böhm, G., additional, and Abstreiter, G., additional
- Published
- 1997
- Full Text
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27. Thin <f>SiOx</f> layers embedded in single crystalline silicon
- Author
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Sticht, A., Markmann, M., Brunner, K., and Abstreiter, G.
- Subjects
- *
SILICON , *HOT carriers - Abstract
In this work, we examine the structural and electronic properties of very thin suboxide layers embedded in silicon. These layers of about
2 nm width are fabricated by exposing a silicon(0 0 1) surface to molecular oxygen up to background pressures of2×10−6 mbar inside the growth chamber of a molecular beam epitaxy system. This layer was then overgrown with silicon. At substrate temperatures between550° C and600° C in situ RHEED measurements reveal single crystalline overgrowth with the2×1 surface reconstruction reappearing after about60 nm . Transmission electron microscopy reveals a continuous layer about2 nm wide with some inhomogenities. Electrical transport measurements across such a barrier exhibit current blocking behavior at low temperatures up to about0.5 V . Current at a given voltage increases with a thermal activation energy of about50 meV . Electron transport across such barrier layers generates hot electrons which are demonstrated to excite erbium ions, leading to light emission at1.54 μm wavelength. [Copyright &y& Elsevier]- Published
- 2002
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28. Electron and hole impact excitation of Er in MBE grown Si:O and Si1-yCy diodes
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Markmann, M., Neumann, R., Brunner, K., and Abstreiter, G.
- Published
- 2001
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29. Optical and magneto-optical investigations on single-quantum dots
- Author
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Zrenner, A., Findeis, F., Beham, E., Markmann, M., Bohm, G., and Abstreiter, G.
- Published
- 2001
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30. Photoluminescence characterization of erbium doped Si1−yCyalloys grown by MBE
- Author
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Markmann, M, Neufeld, E, Brunner, K, Abstreiter, G, and Buchal, Ch
- Abstract
We have studied the influence of carbon codoping in Si1−yCy:Er layers on the photoluminescence efficiency of the 1.54 μm wavelength Er emission. All samples were prepared by molecular beam epitaxy (MBE) with carbon concentrations between y=0.08 and 0.4%. Maximum photoluminescence output at low temperature T=5 K could be realized for growth temperatures around 430°C and an erbium to carbon content ratio of about one ([Er]=4.5×1019cm−3, y=0.1%). The efficiency could be further enhanced by annealing and is comparable to our best Si:Er:O samples. A decrease in photoluminescence intensity at 1.54 μm was observed for increasing sample temperature. It decreases stronger for carbon codoped Si1−yCy:Er layers than for Si:Er:O samples. High resolution photoluminescence spectra show both a difference in the spectral position of the main erbium line as well as in the fine structure for oxygen and carbon codoping.
- Published
- 2000
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31. Spectroscopy of single self-assembled quantum dots
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Zrenner, A., Findeis, F., Beham, E., Markmann, M., and Abstreiter, G.
- Published
- 2000
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32. Magneto-optics of single self-assembled quantum dots.
- Author
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Zrenner, A., Findeis, F., Beham, E., Markmann, M., Bohm, G., and Abstreiter, G.
- Published
- 2000
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33. Dopamine, norepinephrine, and vasopressin accelerate particle transport velocity in murine tracheal epithelium via substance-specific receptor pathways: dependency on intra- and extracellular Ca 2+ sources.
- Author
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Schmidt G, Greif I, Müller S, Markmann M, Edinger F, Sander M, Koch C, and Henrich M
- Abstract
Background: The unique ability of the respiratory tract to protect the integrity of the airways by removing potentially harmful substances is defined as mucociliary clearance. This complex physiological mechanism protects the lower airways by ridding them of pollutants and pathogens. This study aimed to evaluate the potential influence of clinically relevant vasopressors on mucociliary clearance., Material and Methods: The particle transport velocity (PTV) of isolated murine tracheae was measured as a surrogate for mucociliary clearance under the influence of dopamine, norepinephrine, and vasopressin. Inhibitory substances were applied to elucidate relevant signal transduction cascades and the value and origin of calcium ions. Reverse-transcription polymerase chain reactions (RT-PCR) were performed to identify the expression of vasopressin receptor subtypes., Results: Dopamine, norepinephrine, and vasopressin significantly increased the PTV in a dose-dependent manner with half maximal effective concentrations of 0.58 µM, 1.21 µM, and 0.10 µM, respectively. Each substance increased the PTV via separate receptor pathways. While dopamine acted on D
1 -like receptors to increase the PTV, norepinephrine acted on β-adrenergic receptors, and vasopressin acted on V1a receptors. RT-PCR revealed the expression of V1a in the murine whole trachea and tracheal epithelium. PTV increased when protein kinase A was inhibited and norepinephrine or vasopressin were applied, but not when dopamine was applied. Phospholipase C inhibition decreased the PTV when vasopressin was applied. In general, maximum PTV was significantly reduced when extracellular calcium entry was inhibited. When intracellular calcium stores were depleted, no increase in PTV was observed after administering all three substances. Inositol trisphosphate receptor activation was found to be pivotal in the increase in murine PTV after applying dopamine and vasopressin., Discussion: Dopamine, norepinephrine, and vasopressin accelerate the murine PTV via substance-specific receptor pathways. Further investigations should assess the value and interaction of these substances on mucociliary clearance in clinical practice., Competing Interests: The authors declare that the research was conducted in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest., (Copyright © 2024 Schmidt, Greif, Müller, Markmann, Edinger, Sander, Koch and Henrich.)- Published
- 2024
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34. Evaluation of Point-of-Care-Directed Coagulation Management in Pediatric Cardiac Surgery.
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Zajonz T, Edinger F, Hofmann J, Yoerueker U, Akintürk H, Markmann M, and Müller M
- Abstract
Background: Coagulatory alterations are common after pediatric cardiac surgery and can be addressed with point-of-care (POC) coagulation analysis. The aim of the present study is to evaluate a preventive POC-controlled coagulation algorithm in pediatric cardiac surgery., Methods: This single-center, retrospective data analysis included patients younger than 18 years who underwent cardiac surgery with cardiopulmonary bypass (CPB) and received a coagulation therapy according to a predefined POC-controlled coagulation algorithm. Patients were divided into two groups (<10 and >10 kg body weight) because of different CPB priming strategies., Results: In total, 173 surgeries with the use of the POC-guided hemostatic therapy were analyzed. In 71% of cases, target parameters were achieved and only in one case primary sternal closure was not possible. Children with a body weight ≤10 kg underwent surgical re-evaluation in 13.2% (15/113), and respectively 6.7% (4/60) in patients >10 kg. Hemorrhage in children ≤10 kg was associated with cyanotic heart defects, deeper intraoperative hypothermia, longer duration of CPB, more complex procedures (RACHS-1 score), and with more intraoperative platelets, and respectively red blood cell concentrate transfusions (all p- values < 0.05). In children ≤10 kg, fibrinogen levels were significantly lower over the 12-hour postoperative period (without revision: 3.1 [2.9-3.3] vs. with revision 2.8 [2.3-3.4]). Hemorrhage in children >10 kg was associated with a longer duration of CPB ( p = 0.042), lower preoperative platelets ( p = 0.026), and over the 12-hour postoperative period lower platelets ( p = 0.002) and fibrinogen ( p = 0.05)., Conclusion: The use of a preventive, algorithm-based coagulation therapy with factor concentrates after CPB followed by POC created intraoperative clinical stable coagulation status with a subsequent executable thorax closure, although the presented algorithm in its current form is not superior in the reduction of the re-exploration rate compared to equivalent collectives. Reduced fibrinogen concentrations 12 hours after surgery may be associated with an increased incidence of surgical revisions., Competing Interests: None declared., (Thieme. All rights reserved.)
- Published
- 2024
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35. Assessment of risk factors for adverse events in analgosedation for pediatric endoscopy: A 10-year retrospective analysis.
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Schneck E, Knittel F, Markmann M, Balzer F, Rubarth K, Zajonz T, Schreiner AL, Hecker A, Naehrlich L, Koch C, Laffolie J, and Sander M
- Subjects
- Humans, Retrospective Studies, Risk Factors, Child, Female, Male, Child, Preschool, Infant, Adolescent, Incidence, Anesthesia adverse effects, Anesthesia methods, Gastroscopy adverse effects, Gastroscopy methods, Endoscopy, Gastrointestinal adverse effects, Endoscopy, Gastrointestinal methods, Endoscopy, Gastrointestinal statistics & numerical data, Bronchoscopy adverse effects, Bronchoscopy methods, Colonoscopy adverse effects, Colonoscopy methods, Colonoscopy statistics & numerical data
- Abstract
Objectives: Data regarding the occurrence of complications specifically during pediatric anesthesia for endoscopic procedures is limited. By evaluating such data, factors could be identified to assure proper staffing and preparation to minimize adverse events and improve patient safety during flexible endoscopy., Methods: This retrospective cohort study included children undergoing anesthesia for gastroscopy, colonoscopy, bronchoscopy, or combined endoscopic procedures over 10-year period. The primary study aim was to evaluate the incidence of complications and identify risk factors for adverse events., Results: Overall, 2064 endoscopic procedures including 1356 gastroscopies (65.7%), 93 colonoscopies (4.5%), 235 bronchoscopies (11.4%), and 380 combined procedures (18.4%) were performed. Of the 1613 patients, 151 (7.3%) patients exhibited an adverse event, with respiratory complications being the most common (65 [3.1%]). Combination of gastrointestinal endoscopies did not lead to an increased adverse event rate (gastroscopy: 5.5%, colonoscopy: 3.2%). Diagnostic endoscopy as compared to interventional had a lower rate. If bronchoscopy was performed, the rate was similar to that of bronchoscopy alone (19.5% vs. 20.4%). Age < 5.8 years or body weight less than 20 kg, bronchoscopy, American Society of Anesthesiologists status ≥ 2 or pre-existing anesthesia-relevant diseases, and urgency of the procedure were independent risk factors for adverse events. For each risk factor, the risk for events increased 2.1-fold [1.8-2.4]., Conclusions: This study identifies multiple factors that increase the rate of adverse events associated anesthesia-based endoscopy. Combined gastrointestinal procedures did not increase the risk for adverse events while combination of bronchoscopy to gastrointestinal endoscopy showed a similar risk as bronchoscopy alone., (© 2024 The Author(s). Journal of Pediatric Gastroenterology and Nutrition published by Wiley Periodicals LLC on behalf of European Society for Pediatric Gastroenterology, Hepatology, and Nutrition and North American Society for Pediatric Gastroenterology, Hepatology, and Nutrition.)
- Published
- 2024
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36. Nucleated red blood cells are a late biomarker in predicting intensive care unit mortality in patients with COVID-19 acute respiratory distress syndrome: an observational cohort study.
- Author
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Schmidt G, Martens A, Koch C, Markmann M, Schneck E, Matt U, Hecker M, Tello K, Wolff M, Sander M, and Vadász I
- Subjects
- Humans, Retrospective Studies, Intensive Care Units, Cohort Studies, Biomarkers, Erythrocytes, COVID-19, Respiratory Distress Syndrome, Sepsis
- Abstract
Background: Nucleated red blood cells (nRBC) are precursor cells of the erythropoiesis that are absent from the peripheral blood under physiological conditions. Their presence is associated with adverse outcomes in critically ill patients. This study aimed to evaluate the predictive value of nRBC on mortality in intensive care unit (ICU) patients with COVID-19 acute respiratory distress syndrome (ARDS)., Material and Methods: This retrospective, observational cohort study analyzed data on 206 ICU patients diagnosed with COVID-19 ARDS between March 2020 and March 2022. The primary endpoint was ICU mortality, and secondary endpoints included ICU and hospital stay lengths, ventilation hours, and the time courses of disease severity scores and clinical and laboratory parameters., Results: Among the included patients, 68.9% tested positive for nRBC at least once during their ICU stay. A maximum nRBC of 105 µl
-1 had the highest accuracy in predicting ICU mortality (area under the curve of the receiver operating characteristic [AUCROC] 0.780, p < 0.001, sensitivity 69.0%, specificity 75.5%). Mortality was significantly higher among patients with nRBC >105 µl-1 than ≤105 µl-1 (86.5% vs. 51.3%, p = 0.008). Compared to patients negative for nRBC in their peripheral blood, those positive for nRBC required longer mechanical ventilation (127 [44 - 289] h vs. 517 [255 - 950] h, p < 0.001), ICU stays (12 [8 - 19] vs. 27 [13 - 51] d, p < 0.001), and hospital stays (19 [12 - 29] d vs. 31 [16 - 58] d, p < 0.001). Peak Sepsis-related Organ Failure Assessment (SOFA), Simplified Acute Physiology Score, Pa O2 /Fi O2 , interleukin-6, and procalcitonin values were reached before the peak nRBC level. However, the predictive performance of the SOFA (AUCROC 0.842, p < 0.001) was considerably improved when a maximum SOFA score >8 and nRBC >105 µl-1 were combined., Discussion: nRBC predict ICU mortality and indicate disease severity among patients with COVID-19 ARDS, and they should be considered a clinical alarm signal for a worse outcome. nRBC are a late predictor of ICU mortality compared to other established clinical scoring systems and laboratory parameters but improve the prediction accuracy when combined with the SOFA score., Competing Interests: The authors declare that the research was conducted in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest. The author(s) declared that they were an editorial board member of Frontiers, at the time of submission. This had no impact on the peer review process and the final decision., (Copyright © 2024 Schmidt, Martens, Koch, Markmann, Schneck, Matt, Hecker, Tello, Wolff, Sander and Vadász.)- Published
- 2024
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37. Micro-lightguide spectrophotometry assessment of hepatic and intestinal microcirculation in endotoxemic rats during intravenous treatment with angiotensin II.
- Author
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Schmidt G, Pitz L, Markmann M, Schneck E, Sander M, Koch C, and Edinger F
- Subjects
- Rats, Male, Animals, Angiotensin II, Microcirculation physiology, Rats, Inbred Lew, Hemodynamics, Endotoxemia chemically induced, Endotoxemia drug therapy, Shock, Septic drug therapy
- Abstract
Introduction: During septic shock, impairment of microcirculation leads to enhanced permeability of intestinal mucosa triggered by generalized vasodilation and capillary leak. Intravenous angiotensin II (AT-II) has been approved for the treatment of septic shock; however, no in-vivo data exist on the influence of AT-II on hepatic and intestinal microcirculation., Material and Methods: Sixty male Lewis rats were randomly assigned to six study groups (each n = 10): sham, lipopolysaccharide-induced septic shock, therapy with low- or high-dose AT-II (50 or 100 ng/kg/min, respectively), and septic shock treated with low- or high-dose AT-II. After median laparotomy, hepatic and intestinal microcirculation measures derived from micro-lightguide spectrophotometry were assessed for 3 h and included oxygen saturation (SO
2 ), relative blood flow (relBF) and relative hemoglobin level (relHb). Hemodynamic measurements were performed using a left ventricular conductance catheter, and blood samples were taken hourly to analyze blood gasses and systemic cytokines., Results: AT-II increased mean arterial pressure in a dose-dependent manner in both septic and non-septic animals (p < 0.001). Lower hepatic and intestinal SO2 (both p < 0.001) were measured in animals without endotoxemia who received high-dose AT-II treatment, however, significantly impaired cardiac output was also reported in this group (p < 0.001). In endotoxemic rats, hepatic relBF and relHb were comparable among the treatment groups; however, hepatic SO2 was reduced during low- and high-dose AT-II treatment (p < 0.001). In contrast, intestinal SO2 remained unchanged despite treatment with AT-II. Intestinal relBF (p = 0.028) and interleukin (IL)-10 plasma levels (p < 0.001) were significantly elevated during treatment with high-dose AT-II compared with low-dose AT-II., Conclusions: A dose-dependent decrease of hepatic and intestinal microcirculation during therapy with AT-II in non-septic rats was observed, which might have been influenced by a corresponding reduction in cardiac output due to elevated afterload. While hepatic microcirculation was reduced during endotoxemia, no evidence for a reduction in intestinal microcirculation facilitated by AT-II was found. In contrast, both intestinal relBF and anti-inflammatory IL-10 levels were increased during high-dose AT-II treatment., (Copyright © 2023. Published by Elsevier B.V.)- Published
- 2023
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38. Potentials of Acetylcholinesterase and Butyrylcholinesterase Alterations in On-Pump Coronary Artery Bypass Surgery in Postoperative Delirium: An Observational Trial.
- Author
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Zajonz TS, Kunzemann C, Schreiner AL, Beckert F, Schneck E, Boening A, Markmann M, Sander M, and Koch C
- Abstract
Cardiac surgery is regularly associated with postoperative delirium (POD), affected by neuro-inflammation and changes in cholinergic activity. Therefore, this prospective observational study aimed to evaluate whether pre- and perioperative changes in blood acetylcholinesterase (AChE) and butyrylcholinesterase (BChE) activity were associated with POD development in patients undergoing isolated elective coronary artery bypass graft (CABG) surgery. It included 93 patients. Pre- and postoperative blood AChE and BChE activities were measured with photometric rapid-point-of-care-testing. The Intensive Care Delirium Screening Checklist and the Confusion Assessment Method for the Intensive Care Unit were used to screen patients for POD. POD developed in 20 patients (21.5%), who were older ( p = 0.003), had higher EuroSCOREs ( p ≤ 0.001), and had longer intensive care unit stays ( p < 0.001). On postoperative day one, BChE activity decreased from preoperative values more in patients with (31.9%) than without (23.7%) POD (group difference p = 0.002). Applying a cutoff of ≥32.0% for BChE activity changes, receiver operating characteristic analysis demonstrated a moderate prediction capability for POD (area under the curve = 0.72, p = 0.002). The risk of developing POD was 4.31 times higher with a BChE activity change of ≥32.0% ( p = 0.010). Monitoring the pre- to postoperative reduction in BChE activity might be a clinically practicable biomarker for detecting patients at risk of developing POD after CABG surgery.
- Published
- 2023
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39. Hypnotic suggestions cognitively penetrate tactile perception through top-down modulation of semantic contents.
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Markmann M, Lenz M, Höffken O, Steponavičiūtė A, Brüne M, Tegenthoff M, Dinse HR, and Newen A
- Subjects
- Suggestion, Touch, Somatosensory Cortex physiology, Semantics, Touch Perception physiology
- Abstract
Perception is subject to ongoing alterations by learning and top-down influences. Although abundant studies have shown modulation of perception by attention, motivation, content and context, there is an unresolved controversy whether these examples provide true evidence that perception is penetrable by cognition. Here we show that tactile perception assessed as spatial discrimination can be instantaneously and systematically altered merely by the semantic content during hypnotic suggestions. To study neurophysiological correlates, we recorded EEG and SEPs. We found that the suggestion "your index finger becomes bigger" led to improved tactile discrimination, while the suggestion "your index finger becomes smaller" led to impaired discrimination. A hypnosis without semantic suggestions had no effect but caused a reduction of phase-locking synchronization of the beta frequency band between medial frontal cortex and the finger representation in somatosensory cortex. Late SEP components (P80-N140 complex) implicated in attentional processes were altered by the semantic contents, but processing of afferent inputs in SI remained unaltered. These data provide evidence that the psychophysically observed modifiability of tactile perception by semantic contents is not simply due to altered perception-based judgments, but instead is a consequence of modified perceptual processes which change the perceptual experience., (© 2023. The Author(s).)
- Published
- 2023
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40. Peak Plasma Levels of mtDNA Serve as a Predictive Biomarker for COVID-19 in-Hospital Mortality.
- Author
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Edinger F, Edinger S, Koch C, Markmann M, Hecker M, Sander M, and Schneck E
- Abstract
Several predictive biomarkers for coronavirus disease (COVID-19)-associated mortality in critically ill patients have been described. Although mitochondrial DNA (mtDNA) is elevated in patients with COVID-19, the association with coagulation function and its predictive power for mortality is unclear. Accordingly, this study investigates the predictive power of mtDNA for in-hospital mortality in critically ill patients with COVID-19, and whether combining it with thromboelastographic parameters can increase its predictive performance. This prospective explorative study included 29 patients with COVID-19 and 29 healthy matched controls. mtDNA encoding for NADH dehydrogenase 1 (ND1) was quantified using a quantitative polymerase chain reaction analysis, while coagulation function was evaluated using thromboelastometry and impedance aggregometry. Receiver operating characteristic (ROC) curves were used for the prediction of in-hospital mortality. Within the first 24 h, the plasma levels of mtDNA peaked significantly (controls: 65 (28-119) copies/µL; patients: 281 (110-805) at t
0 , 403 (168-1937) at t24 , and 467 (188-952) copies/µL at t72 ; controls vs. patients: p = 0.02 at t0 , p = 0.03 at t24 , and p = 0.44 at t72 ). The mtDNA levels at t24 showed an excellent predictive performance for in-hospital mortality (area under the ROC curve: 0.90 (0.75-0.90)), which could not be improved by the combination with thromboelastometric or aggregometric parameters. Critically ill patients with COVID-19 present an early increase in the plasma levels of ND1 mtDNA, lasting over 24 h. They also show impairments in platelet function and fibrinolysis, as well as hypercoagulability, but these do not correlate with the plasma levels of fibrinogen. The peak plasma levels of mtDNA can be used as a predictive biomarker for in-hospital mortality; however, the combination with coagulation parameters does not improve the predictive validity.- Published
- 2022
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41. Delta-like canonical Notch ligand 1 is predictive for sepsis and acute kidney injury in surgical intensive care patients.
- Author
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Schneck E, Edinger F, Uhle F, Markmann M, Hecker A, Weigand MA, Sander M, and Koch C
- Subjects
- Biomarkers, Critical Care, Humans, Ligands, Acute Kidney Injury diagnosis, Acute Kidney Injury epidemiology, Acute Kidney Injury etiology, Sepsis, Shock, Septic
- Abstract
The early identification of sepsis in surgical intensive care patients is challenging due to the physiological postoperative alterations of vital signs and inflammatory biomarkers. Soluble Delta-like protein 1 (sDLL1) may be a potential discriminatory biomarker for this purpose. For this reason, this study aimed to evaluate sDLL1 for the identification of sepsis in a cohort of surgical intensive care patients. This study comprises a secondary analysis of a prospective observational study including 80 consecutive patients. The study groups included 20 septic shock patients, 20 patients each undergoing major abdominal surgery (MAS) and cardiac artery bypass surgery (CABG), and 20 matched control subjects (CTRL). The surveillance period was 72 h. The plasma concentration of sDLL1 was measured with ELISA. The plasma levels of sDLL1 were significantly elevated in septic patients compared to both surgical cohorts (septic vs. all postoperative time points, data are shown as median and interquartile range [IQR]; septic shock: 17,363 [12,053-27,299] ng/mL, CABG 10,904 [8692-16,250] ng/mL; MAS 6485 [4615-9068] ng/mL; CTRL 5751 [3743-7109] ng/mL; septic shock vs. CABG: p < 0.001; septic shock vs. MAS: p < 0.001). ROC analysis showed a sufficient prediction of sepsis with limited specificity (AUCROC 0.82 [0.75-0.82], sensitivity 84%, specificity 68%). The plasma levels of sDLL correlated closely with renal parameters (creatinine: correlation coefficient = 0.60, r
2 = 0.37, p < 0.0001; urea: correlation coefficient = 0.52, r2 = 0.26, p < 0.0001), resulting in a good predictive performance of sDLL1 for the identification of acute kidney injury (AKI; AUCROC 0.9 [0.82-0.9], sensitivity 83%, specificity 91%). By quantifying the plasma concentration of sDLL1, sepsis can be discriminated from the physiological postsurgical inflammatory response in abdominal and cardiac surgical patients. However, sDLL1 has only limited specificity for the detection of sepsis in cardiac surgical patients, which may be explained by impaired renal function. Based on these findings, this study identifies the predictive value of sDLL1 for the detection of AKI, making it a potential biomarker for surgical intensive care patients.Trial registration DRKS00013584, Internet Portal of the German Clinical Trials Register (DRKS), registration date 11.07.2018, https://www.drks.de/drks_web/navigate.do?navigationId=trial.HTML&TRIAL_ID=DRKS00013584 ., (© 2022. The Author(s).)- Published
- 2022
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42. Minimized Extracorporeal Circulation Is Associated with Reduced Plasma Levels of Free-Circulating Mitochondrial DNA Compared to Conventional Cardiopulmonary Bypass: A Secondary Analysis of an Exploratory, Prospective, Interventional Study.
- Author
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Zajonz T, Koch C, Schwiddessen J, Markmann M, Hecker M, Edinger F, Schmidt G, Boening A, Sander M, and Schneck E
- Abstract
The use of minimized extracorporeal circulation (MiECC) during cardiac surgery is associated with a reduced inflammatory reaction compared to conventional cardiopulmonary bypass (cCPB). Since it is unknown if MiECC also reduces the amount of free-circulating mitochondrial DNA (mtDNA), this study aims to compare MiECC-induced mtDNA release to that of cCPB as well as to identify potential relations between the plasma levels of mtDNA and an adverse outcome. Overall, 45 patients undergoing cardiac surgery with either cCPB or MiECC were included in the study. MtDNA encoding for NADH dehydrogenase 1 was quantified with quantitative polymerase chain reaction. The plasma amount of mtDNA was significantly lower in patients undergoing cardiac surgery with MiECC compared to cCPB (MiECC: 161.8 (65.5−501.9); cCPB 190.8 (82−705.7); p < 0.001). Plasma levels of mtDNA showed comparable kinetics independently of the study group and peaked during CPB (MiECC preoperative: 68.2 (26.5−104.9); MiECC 60 min after start of CPB: 536.5 (215.7−919.6); cCPB preoperative: 152.5 (80.9−207.6); cCPB 60 min after start of CPB: 1818.0 (844.2−3932.2); all p < 0.001). Patients offering an mtDNA blood concentration of >650 copies/µL after the commencement of CPB had a 5-fold higher risk for postoperative atrial fibrillation independently of the type of cardiopulmonary bypass. An amount of mtDNA being higher than 650 copies/µL showed moderate predictive power (AUROC 0.71 (0.53−071)) for the identification of postoperative atrial fibrillation. In conclusion, plasma levels of mtDNA were lower in patients undergoing cardiac surgery with MiECC compared to cCPB. The amount of mtDNA at the beginning of the CPB was associated with postoperative atrial fibrillation independent of the type of cardiopulmonary bypass.
- Published
- 2022
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43. 3D Automated Segmentation of Lower Leg Muscles Using Machine Learning on a Heterogeneous Dataset.
- Author
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Rohm M, Markmann M, Forsting J, Rehmann R, Froeling M, and Schlaffke L
- Abstract
Quantitative MRI combines non-invasive imaging techniques to reveal alterations in muscle pathophysiology. Creating muscle-specific labels manually is time consuming and requires an experienced examiner. Semi-automatic and fully automatic methods reduce segmentation time significantly. Current machine learning solutions are commonly trained on data from healthy subjects using homogeneous databases with the same image contrast. While yielding high Dice scores (DS), those solutions are not applicable to different image contrasts and acquisitions. Therefore, the aim of our study was to evaluate the feasibility of automatic segmentation of a heterogeneous database. To create a heterogeneous dataset, we pooled lower leg muscle images from different studies with different contrasts and fields-of-view, containing healthy controls and diagnosed patients with various neuromuscular diseases. A second homogenous database with uniform contrasts was created as a subset of the first database. We trained three 3D-convolutional neuronal networks (CNN) on those databases to test performance as compared to manual segmentation. All networks, training on heterogeneous data, were able to predict seven muscles with a minimum average DS of 0.75. U-Net performed best when trained on the heterogeneous dataset (DS: 0.80 ± 0.10, AHD: 0.39 ± 0.35). ResNet and DenseNet yielded higher DS, when trained on a heterogeneous dataset (both DS: 0.86), as compared to a homogeneous dataset (ResNet DS: 0.83, DenseNet DS: 0.76). In conclusion, a CNN trained on a heterogeneous dataset achieves more accurate labels for predicting a heterogeneous database of lower leg muscles than a CNN trained on a homogenous dataset. We propose that a large heterogeneous database is needed, to make automated segmentation feasible for different kinds of image acquisitions.
- Published
- 2021
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44. Application of alpha1-antitrypsin in a rat model of veno-arterial extracorporeal membrane oxygenation.
- Author
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Edinger F, Schmitt C, Koch C, McIntosh JM, Janciauskiene S, Markmann M, Sander M, Padberg W, and Grau V
- Subjects
- Animals, Male, Rats, Rats, Inbred Lew, Cardiac Output drug effects, Cytokines metabolism, Extracorporeal Membrane Oxygenation methods, Hemodynamics, Trypsin Inhibitors pharmacology, alpha 1-Antitrypsin pharmacology
- Abstract
Extracorporeal membrane oxygenation (ECMO) is a life-saving intervention for patients suffering from respiratory or cardiac failure. The ECMO-associated morbidity and mortality depends to a large extent on the underlying disease and is often related to systemic inflammation, consecutive immune paralysis and sepsis. Here we tested the hypothesis that human α1-antitrypsin (SERPINA1) due to its anti-protease and anti-inflammatory functions may attenuate ECMO-induced inflammation. We specifically aimed to test whether intravenous treatment with α1-antitrypsin reduces the release of cytokines in response to 2 h of experimental ECMO. Adult rats were intravenously infused with α1-antitrypsin immediately before starting veno-arterial ECMO. We measured selected pro- and anti-inflammatory cytokines and found, that systemic levels of tumor necrosis factor-α, interleukin-6 and interleukin-10 increase during experimental ECMO. As tachycardia and hypertension developed in response to α1-antitrypsin, a single additional bolus of fentanyl and midazolam was given. Treatment with α1-antitrypsin and higher sedative doses reduced all cytokine levels investigated. We suggest that α1-antitrypsin might have the potential to protect against both ECMO-induced systemic inflammation and immune paralysis. More studies are needed to corroborate our findings, to clarify the mechanisms by which α1-antitrypsin inhibits cytokine release in vivo and to explore the potential application of α1-antitrypsin in clinical ECMO., (© 2021. The Author(s).)
- Published
- 2021
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45. Combined Administration of Fibrinogen and Factor XIII Concentrate Does Not Improve Dilutional Coagulopathy Superiorly Than Sole Fibrinogen Therapy: Results of an In-Vitro Thrombelastographic Study.
- Author
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Schneck E, Muelich M, Markmann M, Edinger F, Cooper N, Moeller A, Bein G, Hecker A, Koch C, Sander M, and Wolff M
- Abstract
The early administration of fibrinogen has gained wide acceptance for the treatment of major hemorrhage, whereas the substitution of coagulation factor XIII (FXIII) is only supported by a low level of evidence. This study aimed to answer the question of whether a combined therapy of fibrinogen/FXIII substitution performs superiorly to sole fibrinogen administration in the treatment of dilutional coagulopathy. An in-vitro model of massive transfusion was used to compare the effect of combined fibrinogen/FXIII administration to that of sole fibrinogen therapy for the treatment of dilutional coagulopathy. For this purpose, the blood of red blood cell concentrates, fresh frozen plasma, and platelet concentrates were reconstituted in a ratio of 4:4:1, and then diluted with gelatin by 20% and 40%, respectively. Clot formation and stability were analyzed by thrombelastography. Both sole fibrinogen therapy (equivalent to 50 mg/kg) and the combined administration of fibrinogen (equivalent to 50 mg/kg) and FXIII (equivalent to 75 International Units (IU)/kg) increased fibrinogen-dependent mean clot firmness independently of the degree of dilution (20% dilution: 7 (6.3-7.8) mm; 20% dilution fibrinogen: 13.5 (13-17.3) mm; 20% dilution fibrinogen/FXIII: 16.5 (15.3-18.8) mm; 40% dilution: 3 (2-3.8) mm; 40% dilution fibrinogen: 8 (7-11.3) mm; 40% dilution fibrinogen/FXIII: 10 (8.3-11.8) mm; all p < 0.01). However, no differences were identified between the two treatment arms. Compared to fibrinogen therapy, no beneficial effect of the combined administration of fibrinogen and FXIII for the treatment of dilutional coagulopathy was detected in this in-vitro massive transfusion model. The result was independent of the degree of dilution.
- Published
- 2021
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46. Uropathogenic Escherichia coli Virulence Factor α-Hemolysin Reduces Histone Acetylation to Inhibit Expression of Proinflammatory Cytokine Genes.
- Author
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Zhang Z, Wang M, Zhang Y, Zhang Y, Bartkuhn M, Markmann M, Hossain H, Chakraborty T, Hake SB, Jia Z, Meinhardt A, and Bhushan S
- Subjects
- Acetylation, Animals, Cytokines genetics, Escherichia coli Proteins metabolism, Histones metabolism, Host-Pathogen Interactions, Humans, Immunity, Innate, Mice, Virulence Factors metabolism, Cytokines immunology, Escherichia coli Infections immunology, Hemolysin Proteins metabolism, Urinary Tract Infections immunology, Uropathogenic Escherichia coli metabolism
- Abstract
Urinary tract infections are common and costly diseases affecting millions of people. Uropathogenic Escherichia coli (UPEC) is a primary cause of these infections and has developed multiple strategies to avoid the host immune response. Here, we dissected the molecular mechanisms underpinning UPEC inhibition of inflammatory cytokine in vitro and in vivo. We found that UPEC infection simulates nuclear factor-κB activation but does not result in transcription of cytokine genes. Instead, UPEC-mediated suppression of the metabolic enzyme ATP citrate lyase results in decreased acetyl-CoA levels, leading to reduced H3K9 histone acetylation in the promotor region of CXCL8. These effects were dependent on the UPEC virulence factor α-hemolysin and were reversed by exogenous acetate. In a murine cystitis model, prior acetate supplementation rapidly resolved UPEC-elicited immune responses and improved tissue recovery. Thus, upon infection, UPEC rearranges host cell metabolism to induce chromatin remodeling processes that subvert expression of host innate immune response genes., (© The Author(s) 2021. Published by Oxford University Press for the Infectious Diseases Society of America. All rights reserved. For permissions, e-mail: journals.permissions@oup.com.)
- Published
- 2021
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- View/download PDF
47. Hypotension Prediction Index based protocolized haemodynamic management reduces the incidence and duration of intraoperative hypotension in primary total hip arthroplasty: a single centre feasibility randomised blinded prospective interventional trial.
- Author
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Schneck E, Schulte D, Habig L, Ruhrmann S, Edinger F, Markmann M, Habicher M, Rickert M, Koch C, and Sander M
- Subjects
- Feasibility Studies, Hemodynamics, Humans, Incidence, Intraoperative Complications, Prospective Studies, Arthroplasty, Replacement, Hip adverse effects, Hypotension epidemiology, Hypotension prevention & control
- Abstract
The "Hypotension Prediction Index (HPI)" represents a newly introduced monitoring-tool that aims to predict episodes of intraoperative hypotension (IOH) before their occurrence. In order to evaluate the feasibility of protocolized care according to HPI monitoring, we hypothesized that HPI predicts the incidence of IOH and reduces the incidence and duration of IOH. This single centre feasibility randomised blinded prospective interventional trial included at total of 99 patients. One group was managed by goal-directed therapy algorithm based on HPI (HPI, n = 25), which was compared to a routine anaesthetic care cohort (CTRL, n = 24) and a third historic control group (hCTRL, n = 50). Primary endpoints included frequency (n)/h, absolute and relative duration (t (min)/% of total anaesthesia time) of IOH. Significant reduction of intraoperative hypotension was recorded in the HPI group compared to the control groups (HPI 48%, CTRL 87.5%, hCTRL 80%; HPI vs. CTRL, respectively hCTRL p < 0.001). Perioperative quantity of IOH was significantly reduced in the interventional group compared to both other study groups (HPI: 0 (0-1), CTRL: 5 (2-6), hCTRL: 2 (1-3); p < 0.001). Same observations were identified for absolute (HPI: 0 (0-140) s, CTRL: 640 (195-1315) s, hCTRL 660 (180-1440) s; p < 0.001) and relative duration of hypotensive episodes (minutes MAP ≤ 65 mmHg in % of total anaesthesia time; HPI: 0 (0-1), CTRL: 6 (2-12), hCTRL 7 (2-17); p < 0.001). The HPI algorithm combined with a protocolized treatment was able to reduce the incidence and duration of hypotensive events in patients undergoing primary hip arthroplasty.Trial registration: NCT03663270.
- Published
- 2020
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48. Comparison of qSOFA score, SOFA score, and SIRS criteria for the prediction of infection and mortality among surgical intermediate and intensive care patients.
- Author
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Koch C, Edinger F, Fischer T, Brenck F, Hecker A, Katzer C, Markmann M, Sander M, and Schneck E
- Subjects
- Adult, Aged, Critical Illness, Female, Germany epidemiology, Hospital Mortality, Humans, Intensive Care Units, Male, Middle Aged, Predictive Value of Tests, Prognosis, Retrospective Studies, Organ Dysfunction Scores, Sepsis mortality, Surgical Wound Infection mortality, Systemic Inflammatory Response Syndrome mortality
- Abstract
Background: It is crucial to rapidly identify sepsis so that adequate treatment may be initiated. Accordingly, the Sequential Organ Failure Assessment (SOFA) and the quick SOFA (qSOFA) scores are used to evaluate intensive care unit (ICU) and non-ICU patients, respectively. As demand for ICU beds rises, the intermediate care unit (IMCU) carries greater importance as a bridge between the ICU and the regular ward. This study aimed to examine the ability of SOFA and qSOFA scores to predict suspected infection and mortality in IMCU patients., Methods: Retrospective data analysis included 13,780 surgical patients treated at the IMCU, ICU, or both between January 01, 2012, and September 30, 2018. Patients were screened for suspected infection (i.e., the commencement of broad-spectrum antibiotics) and then evaluated for the SOFA score, qSOFA score, and the 1992 defined systemic inflammatory response syndrome (SIRS) criteria., Results: Suspected infection was detected in 1306 (18.3%) of IMCU, 1365 (35.5%) of ICU, and 1734 (62.0%) of IMCU/ICU encounters. Overall, 458 (3.3%) patients died (IMCU 45 [0.6%]; ICU 250 [6.5%]; IMCU/ICU 163 [5.8%]). All investigated scores failed to predict suspected infection independently of the analyzed subgroup. Regarding mortality prediction, the qSOFA score performed sufficiently within the IMCU cohort (AUCROC SIRS 0.72 [0.71-0.72]; SOFA 0.52 [0.51-0.53]; qSOFA 0.82 [0.79-0.84]), while the SOFA score was predictive in patients of the IMCU/ICU cohort (AUCROC SIRS 0.54 [0.53-0.54]; SOFA 0.73 [0.70-0.77]; qSOFA 0.59 [0.58-0.59])., Conclusions: None of the assessed scores was sufficiently able to predict suspected infection in surgical ICU or IMCU patients. While the qSOFA score is appropriate for mortality prediction in IMCU patients, SOFA score prediction quality is increased in critically ill patients.
- Published
- 2020
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49. Blood Levels of Free-Circulating Mitochondrial DNA in Septic Shock and Postsurgical Systemic Inflammation and Its Influence on Coagulation: A Secondary Analysis of a Prospective Observational Study.
- Author
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Schneck E, Edinger F, Hecker M, Sommer N, Pak O, Weissmann N, Hecker A, Reichert M, Markmann M, Sander M, and Koch C
- Abstract
Major surgery is regularly associated with clinical signs of systemic inflammation, which potentially affects the rapid identification of sepsis. Therefore, this secondary analysis of an observational study aims to determine whether NADH dehydrogenase 1 (ND1) mitochondrial DNA (mtDNA) could be used as a potential biomarker for the discrimination between septic shock and postsurgical systemic inflammation. Overall, 80 patients were included (septic shock ( n = 20), cardiac artery bypass grafting (CABG, n = 20), major abdominal surgery (MAS, n = 20), and matched controls (CTRL, n = 20)). Quantitative PCR was performed to measure ND1 mtDNA. Thromboelastography was used to analyze the coagulatory system. Free-circulating ND1 mtDNA levels were significantly higher in septic shock patients compared to patients suffering from post-surgical inflammation ({copies/µL}: CTRL: 1208 (668-2685); septic shock: 3823 (2170-7318); CABG: 1272 (417-2720); and MAS: 1356 (694-2845); CTRL vs. septic shock: p < 0.001; septic shock vs. CABG: p < 0.001; septic shock vs. MAS: p = 0.006; CABG vs. MAS: p = 0.01). ND1 mtDNA levels in CABG patients showed a strong positive correlation with fibrinogen (correlation coefficient [ r ]= 0.57, p < 0.001) and fibrinogen-dependent thromboelastographic assays (maximum clot firmness, EXTEM: r = 0.35, p = 0.01; INTEM: r = 0.31, p = 0.02; FIBTEM: r = 0.46, p < 0.001). In conclusion, plasma levels of free-circulating ND1 mtDNA were increased in septic shock patients and were discriminative between sepsis and surgery-induced inflammation. Furthermore, this study showed an association between ND1 mtDNA and a fibrinogen-dependent pro-coagulatory shift in cardiac surgical patients.
- Published
- 2020
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50. Evaluation of pulse wave transit time analysis for non-invasive cardiac output quantification in pregnant patients.
- Author
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Schneck E, Drubel P, Schürg R, Markmann M, Kohl T, Henrich M, Sander M, and Koch C
- Subjects
- Adult, Female, Heart Rate physiology, Humans, Monitoring, Intraoperative methods, Pregnancy, Stroke Volume physiology, Thermodilution methods, Cardiac Output physiology, Heart physiology, Monitoring, Physiologic methods, Pulse Wave Analysis methods
- Abstract
Pregnant patients undergoing minimally-invasive foetoscopic surgery for foetal spina bifida have a need to be subjected to advanced haemodynamic monitoring. This observational study compares cardiac output as measured by transpulmonary thermodilution monitoring with the results of non-invasive estimated continuous cardiac output monitoring. Transpulmonary thermodilution-based pulse contour analysis was performed for usual anaesthetic care, while non-invasive estimated continuous cardiac output monitoring data were additionally recorded. Thirty-five patients were enrolled, resulting in 199 measurement time points. Cardiac output measurements of the non-invasive estimated continuous cardiac output monitoring showed a weak correlation with the corresponding thermodilution measurements (correlation coefficient: 0.44, R
2 : 0.19; non-invasive estimated continuous cardiac output: 7.4 [6.2-8.1]; thermodilution cardiac output: 8.9 [7.8-9.8]; p ≤ 0.001), while cardiac index experienced no such correlation. Furthermore, neither stroke volume nor stroke volume index correlated with the corresponding thermodilution-based data. Even though non-invasive estimated continuous cardiac output monitoring consistently underestimated the corresponding thermodilution parameters, no trend analysis was achievable. Summarizing, we cannot suggest the use of non-invasive estimated continuous cardiac output monitoring as an alternative to transpulmonary thermodilution for cardiac output monitoring in pregnant patients undergoing minimally-invasive foetoscopic surgery for spina bifida.- Published
- 2020
- Full Text
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