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Varma VR, An Y, Kac PR, Bilgel M, Moghekar A, Loeffler T, Amschl D, Troncoso J, Blennow K, Zetterberg H, Ashton NJ, Resnick SM, Thambisetty M. Longitudinal progression of blood biomarkers reveals a key role of astrocyte reactivity in preclinical Alzheimer's disease. medRxiv 2024:2024.01.25.24301779. [PMID: 38343809 PMCID: PMC10854357 DOI: 10.1101/2024.01.25.24301779] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Indexed: 02/26/2024]
Abstract
Defining the progression of blood biomarkers of Alzheimer's disease (AD) is essential for targeting treatments in patients most likely to benefit from early intervention. We delineated the temporal ordering of blood biomarkers a decade prior to the onset of AD symptoms in participants in the Baltimore Longitudinal Study of Aging. We show that increased astrocyte reactivity, assessed by elevated glial fibrillary acidic protein (GFAP) levels is an early event in the progression of blood biomarker changes in preclinical AD. In AD-converters who are initially cognitively unimpaired (N=158, 377 serial plasma samples), higher plasma GFAP levels are observed as early as 10-years prior to the onset of cognitive impairment due to incident AD compared to individuals who remain cognitively unimpaired (CU, N=160, 379 serial plasma samples). Plasma GFAP levels in AD-converters remain elevated 5-years prior to and coincident with the onset of cognitive impairment due to AD. In participants with neuropathologically confirmed AD, plasma GFAP levels are elevated relative to cognitively normal individuals and intermediate in those who remain cognitively unimpaired despite significant AD pathology (asymptomatic AD). Higher plasma GFAP levels at death are associated with greater severity of both neuritic plaques and neurofibrillary tangles. In the 5XFAD transgenic model of AD, we observed greater GFAP levels in the cortex and hippocampus of transgenic mice relative to wild-type prior to the development of cognitive impairment. Reactive astrocytosis, an established biological response to neuronal injury, may be an early initiator of AD pathogenesis and a promising therapeutic target.
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Affiliation(s)
- V R Varma
- Clinical and Translational Neuroscience Section, Laboratory of Behavioral Neuroscience, National Institute on Aging (NIA), National Institutes of Health (NIH), Baltimore, Maryland, United States of America
| | - Y An
- Brain Aging and Behavior Section, Laboratory of Behavioral Neuroscience, National Institute on Aging (NIA), National Institutes of Health (NIH), Baltimore, MD, USA
| | - P R Kac
- Department of Psychiatry and Neurochemistry, Institute of Neuroscience & Physiology, the Sahlgrenska Academy at the University of Gothenburg, Mölndal, Sweden
| | - M Bilgel
- Brain Aging and Behavior Section, Laboratory of Behavioral Neuroscience, National Institute on Aging (NIA), National Institutes of Health (NIH), Baltimore, MD, USA
| | - A Moghekar
- Department of Neurology, Johns Hopkins University School of Medicine, Baltimore, MD 21224, USA
| | - T Loeffler
- Scantox Neuro GmbH, Parkring 12, 8074, Grambach, Austria
| | - D Amschl
- Scantox Neuro GmbH, Parkring 12, 8074, Grambach, Austria
| | - J Troncoso
- Department of Pathology, Johns Hopkins University School of Medicine, Baltimore, MD, USA
| | - K Blennow
- Department of Psychiatry and Neurochemistry, Institute of Neuroscience & Physiology, the Sahlgrenska Academy at the University of Gothenburg, Mölndal, Sweden
- Clinical Neurochemistry Laboratory, Sahlgrenska University Hospital, Mölndal, Sweden
| | - H Zetterberg
- Department of Psychiatry and Neurochemistry, Institute of Neuroscience & Physiology, the Sahlgrenska Academy at the University of Gothenburg, Mölndal, Sweden
- Clinical Neurochemistry Laboratory, Sahlgrenska University Hospital, Mölndal, Sweden
- Department of Neurodegenerative Disease, UCL Institute of Neurology, London, UK
- UK Dementia Research Institute at UCL, London, UK
- Hong Kong Center for Neurodegenerative Diseases, Clear Water Bay, Hong Kong, China
- Wisconsin Alzheimer's Disease Research Center, University of Wisconsin School of Medicine and Public Health, University of Wisconsin-Madison, Madison, WI, USA
| | - N J Ashton
- Department of Psychiatry and Neurochemistry, Institute of Neuroscience & Physiology, the Sahlgrenska Academy at the University of Gothenburg, Mölndal, Sweden
- King's College London, Institute of Psychiatry, Psychology and Neuroscience Maurice Wohl Institute Clinical Neuroscience Institute London UK
- NIHR Biomedical Research Centre for Mental Health and Biomedical Research Unit for Dementia at South London and Maudsley NHS Foundation London UK
- Centre for Age-Related Medicine, Stavanger University Hospital, Stavanger, Norway
| | - S M Resnick
- Brain Aging and Behavior Section, Laboratory of Behavioral Neuroscience, National Institute on Aging (NIA), National Institutes of Health (NIH), Baltimore, MD, USA
| | - M Thambisetty
- Clinical and Translational Neuroscience Section, Laboratory of Behavioral Neuroscience, National Institute on Aging (NIA), National Institutes of Health (NIH), Baltimore, Maryland, United States of America
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Sheyfer D, Servis MJ, Zhang Q, Lal J, Loeffler T, Dufresne EM, Sandy AR, Narayanan S, Sankaranarayanan SKRS, Szczygiel R, Maj P, Soderholm L, Antonio MR, Stephenson GB. Correction to "Advancing Chemical Separations: Unraveling the Structure and Dynamics of Phase Splitting in Liquid-Liquid Extraction". J Phys Chem B 2023; 127:8282-8283. [PMID: 37704206 DOI: 10.1021/acs.jpcb.3c05648] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 09/15/2023]
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Fahmy SB, Zamzam M, Khalil T, Abdalla Y, Loeffler T, Ahmed SA, Abd-Elhady MS. Influence of the hot water mass flow rate on heating of radiant floors of green buildings. Journal of Building Physics 2023; 47:182-203. [DOI: 10.1177/17442591231182330] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 09/02/2023]
Abstract
The objective of the research is to improve space heating of green buildings by examining experimentally the influence of the heating medium mass flow rate on thermal performance. A green building was built in Cairo, Egypt, that consists of two similar rooms: one is the heated room and the other is a reference for comparison. A photovoltaic thermal (PV/T) collector is used to heat up water in a storage tank, and the hot water in the tank is circulated in the radiant floor of the examined green building. The hot water mass flow rate was varied between 0.04 and 0.08 kg/s. It was found that decreasing the water mass flow rate improves the heating of the radiant floor. The percentage improvement in floor temperature due to heating over the reference room, reaches about 17% and 6% at mass flow rates of 0.04 and 0.08 kg/s, respectively. Engineering Equation Solver (EES) was used to solve the equations for the heat transfer process between the heating water and the floor. It was found that decreasing the mass flow rate increases the residence time of the heating water in the radiant floor, consequently, increases the heat energy transfer and the floor temperature. Increasing the heating fluid mass flow rate in green buildings could have a negative effect on the heat transfer, such that the appropriate heating fluid mass flow rate should be calculated based on the green building massive material as well as the operating conditions, for example, ambient temperature and wind speed.
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Affiliation(s)
- Sarah B Fahmy
- Mechanical Department, Faculty of Engineering, German International University, Cairo, Egypt
| | - M Zamzam
- Physics Department, Faculty of Engineering and Materials Science, German University in Cairo, Egypt
| | - T Khalil
- Physics Department, Faculty of Engineering and Materials Science, German University in Cairo, Egypt
| | - Yasmine Abdalla
- Electrical Department, Faculty of Engineering, German International University, Cairo, Egypt
| | - Thomas Loeffler
- Architecture and Urban Design Program, Building Technology, German University in Cairo, Egypt
| | - SA Ahmed
- Mechanical Engineering Department, Faculty of Engineering, Beni-Suef University, Beni-Suef, Egypt
| | - MS Abd-Elhady
- Mechanical Engineering Department, Faculty of Engineering, Beni-Suef University, Beni-Suef, Egypt
- Mechatronics Department, Faculty of Engineering and Materials Science, German University in Cairo, Egypt
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Sheyfer D, Servis MJ, Zhang Q, Lal J, Loeffler T, Dufresne EM, Sandy AR, Narayanan S, Sankaranarayanan SKRS, Szczygiel R, Maj P, Soderholm L, Antonio MR, Stephenson GB. Advancing Chemical Separations: Unraveling the Structure and Dynamics of Phase Splitting in Liquid-Liquid Extraction. J Phys Chem B 2022; 126:2420-2429. [PMID: 35315675 DOI: 10.1021/acs.jpcb.1c09996] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
Liquid-liquid extraction (LLE), the go-to process for a variety of chemical separations, is limited by spontaneous organic phase splitting upon sufficient solute loading, called third phase formation. In this study we explore the applicability of critical phenomena theory to gain insight into this deleterious phase behavior with the goal of improving separations efficiency and minimizing waste. A series of samples representative of rare earth purification were constructed to include each of one light and one heavy lanthanide (cerium and lutetium) paired with one of two common malonamide extractants (DMDOHEMA and DMDBTDMA). The resulting postextraction organic phases are chemically complex and often form rich hierarchical structures whose statics and dynamics near the critical point were probed herein with small-angle X-ray scattering and high-speed X-ray photon correlation spectroscopy. Despite their different extraction behaviors, all samples show remarkably similar critical behavior with exponents well described by classical critical point theory consistent with the 3D Ising model, where the critical behavior is characterized by fluctuations with a single diverging length scale. This unexpected result indicates a significant reduction in relevant chemical parameters at the critical point, indicating that the underlying behavior of phase transitions in LLE rely on far fewer variables than are generally assumed. The obtained scalar order parameter is attributed to the extractant fraction of the extractant/diluent mixture, revealing that other solution components and their respective concentrations simply shift the critical temperature but do not affect the nature of the critical fluctuations. These findings point to an opportunity to drastically simplify studies of liquid-liquid phase separation and phase diagram development in general while providing insights into LLE process improvement.
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Affiliation(s)
- D Sheyfer
- X-ray Science Division, Argonne National Laboratory, Argonne, Illinois 60439, United States
- Materials Science Division, Argonne National Laboratory, Argonne, Illinois 60439, United States
| | - Michael J Servis
- Chemical Sciences and Engineering Division, Argonne National Laboratory, Argonne, Illinois 60439, United States
| | - Qingteng Zhang
- X-ray Science Division, Argonne National Laboratory, Argonne, Illinois 60439, United States
| | - J Lal
- Materials Science Division, Argonne National Laboratory, Argonne, Illinois 60439, United States
- Department of Physics, Northern Illinois University, DeKalb, Illinois 60115, United States
| | - T Loeffler
- Nanoscale Science and Technology Division, Argonne National Laboratory, Argonne, Illinois 60439, United States
| | - E M Dufresne
- X-ray Science Division, Argonne National Laboratory, Argonne, Illinois 60439, United States
| | - A R Sandy
- X-ray Science Division, Argonne National Laboratory, Argonne, Illinois 60439, United States
| | - S Narayanan
- X-ray Science Division, Argonne National Laboratory, Argonne, Illinois 60439, United States
| | - Subramanian K R S Sankaranarayanan
- Nanoscale Science and Technology Division, Argonne National Laboratory, Argonne, Illinois 60439, United States
- Department of Mechanical and Industrial Engineering, University of Illinois, Chicago, Illinois 60607,United States
| | - R Szczygiel
- AGH University of Science and Technology, Krakow 30-059, Poland
| | - P Maj
- AGH University of Science and Technology, Krakow 30-059, Poland
| | - L Soderholm
- Chemical Sciences and Engineering Division, Argonne National Laboratory, Argonne, Illinois 60439, United States
| | - Mark R Antonio
- Chemical Sciences and Engineering Division, Argonne National Laboratory, Argonne, Illinois 60439, United States
| | - G B Stephenson
- Materials Science Division, Argonne National Laboratory, Argonne, Illinois 60439, United States
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Sheyfer D, Zhang Q, Lal J, Loeffler T, Dufresne EM, Sandy AR, Narayanan S, Sankaranarayanan SKRS, Szczygiel R, Maj P, Soderholm L, Antonio MR, Stephenson GB. Nanoscale Critical Phenomena in a Complex Fluid Studied by X-Ray Photon Correlation Spectroscopy. Phys Rev Lett 2020; 125:125504. [PMID: 33016761 DOI: 10.1103/physrevlett.125.125504] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/28/2020] [Revised: 05/27/2020] [Accepted: 07/14/2020] [Indexed: 06/11/2023]
Abstract
The advent of high-speed x-ray photon correlation spectroscopy now allows the study of critical phenomena in fluids to much smaller length scales and over a wider range of temperatures than is possible with dynamic light scattering. We present an x-ray photon correlation spectroscopy study of critical fluctuation dynamics in a complex fluid typical of those used in liquid-liquid extraction (LLE) of ions, dodecane-DMDBTDMA with extracted aqueous Ce(NO_{3})_{3}. We observe good agreement with both static and dynamic scaling without the need for significant noncritical background corrections. Critical exponents agree with 3D Ising values, and the fluctuation dynamics are described by simple exponential relaxation. The form of the dynamic master curve deviates somewhat from the Kawasaki result, with a more abrupt transition between the critical and noncritical asymptotic behavior. The concepts of critical phenomena thus provide a quantitative framework for understanding the structure and dynamics of LLE systems and a path forward to new LLE processes.
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Affiliation(s)
- D Sheyfer
- Materials Science Division, Argonne National Laboratory, Argonne, Illinois 60439, USA
| | - Qingteng Zhang
- X-Ray Science Division, Argonne National Laboratory, Argonne, Illinois 60439, USA
| | - J Lal
- Materials Science Division, Argonne National Laboratory, Argonne, Illinois 60439, USA
- Department of Physics, Northern Illinois University, DeKalb, Illinois 60115, USA
| | - T Loeffler
- Nanoscale Science and Technology Division, Argonne National Laboratory, Argonne, Illinois 60439, USA
| | - E M Dufresne
- X-Ray Science Division, Argonne National Laboratory, Argonne, Illinois 60439, USA
| | - A R Sandy
- X-Ray Science Division, Argonne National Laboratory, Argonne, Illinois 60439, USA
| | - S Narayanan
- X-Ray Science Division, Argonne National Laboratory, Argonne, Illinois 60439, USA
| | - S K R S Sankaranarayanan
- Nanoscale Science and Technology Division, Argonne National Laboratory, Argonne, Illinois 60439, USA
- Department of Mechanical and Industrial Engineering, University of Illinois, Chicago, Illinois 60607, USA
| | - R Szczygiel
- AGH University of Science and Technology, Krakow 30-059, Poland
| | - P Maj
- AGH University of Science and Technology, Krakow 30-059, Poland
| | - L Soderholm
- Chemical Science and Engineering Division, Argonne National Laboratory, Argonne, Illinois 60439, USA
| | - M R Antonio
- Chemical Science and Engineering Division, Argonne National Laboratory, Argonne, Illinois 60439, USA
| | - G B Stephenson
- Materials Science Division, Argonne National Laboratory, Argonne, Illinois 60439, USA
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Schmutz A, Loeffler T, Schmidt A, Goebel U. LMA Gastro™ airway is feasible during upper gastrointestinal interventional endoscopic procedures in high risk patients: a single-center observational study. BMC Anesthesiol 2020; 20:40. [PMID: 32035477 PMCID: PMC7007643 DOI: 10.1186/s12871-020-0938-9] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/04/2019] [Accepted: 01/13/2020] [Indexed: 01/16/2023] Open
Abstract
Background Nonoperating room anesthesia during gastroenterological procedures is a growing field in anesthetic practice. While the numbers of patients with severe comorbidities are rising constantly, gastrointestinal endoscopic interventions are moving closer to minimally invasive endoscopic surgery. The LMA Gastro™ is a new supraglottic airway device, developed specifically for upper gastrointestinal endoscopy and interventions. The aim of this study was to evaluate the feasibility of LMA Gastro™ in patients with ASA physical status ≥3 undergoing advanced endoscopic procedures. Methods We analyzed data from 214 patients retrospectively who received anesthesia for gastroenterological interventions. Inclusion criteria were upper gastrointestinal endoscopic interventions, airway management with LMA Gastro™ and ASA status ≥3. The primary outcome measure was successful use of LMA Gastro™ for airway management and endoscopic intervention. Results Thirtyone patients with ASA physical status ≥3, undergoing complex and prolonged upper gastrointestinal endoscopic procedures were included. There were 7 endoscopic retrograde cholangiopancreatographies, 7 peroral endoscopic myotomies, 5 percutaneous endoscopic gastrostomies and 12 other complex procedures (e.g. endoscopic submucosal dissection, esophageal stent placement etc.). Of these, 27 patients were managed successfully using the LMA Gastro™. Placement of the LMA Gastro™ was reported as easy. Positive pressure ventilation was performed without difficulty. The feasibility of the LMA Gastro™ for endoscopic intervention was rated excellent by the endoscopists. In four patients, placement or ventilation with LMA Gastro™ was not possible. Conclusions We demonstrated the feasibility of the LMA Gastro™ during general anesthesia for advanced endoscopic procedures in high-risk patients. Trial registration German Clinical Trials Register (DRKS00017396) Date of registration: 23rd May 2019, retrospectively registered.
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Affiliation(s)
- Axel Schmutz
- Department of Anesthesiology and Critical Care, Faculty of Medicine, Medical Center - University of Freiburg, University of Freiburg, Hugstetter Strasse 55, 79106, Freiburg im Breisgau, Germany.
| | - Thomas Loeffler
- Department of Anesthesiology and Critical Care, Faculty of Medicine, Medical Center - University of Freiburg, University of Freiburg, Hugstetter Strasse 55, 79106, Freiburg im Breisgau, Germany
| | - Arthur Schmidt
- Department of Medicine II, Faculty of Medicine, Medical Center - University of Freiburg University of Freiburg, Hugstetter Strasse 55, Freiburg im Breisgau, 79106, Germany
| | - Ulrich Goebel
- Department of Anesthesiology and Critical Care, Faculty of Medicine, Medical Center - University of Freiburg, University of Freiburg, Hugstetter Strasse 55, 79106, Freiburg im Breisgau, Germany
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Kaufmann KB, Baar W, Rexer J, Loeffler T, Heinrich S, Konstantinidis L, Buerkle H, Goebel U. Evaluation of hemodynamic goal-directed therapy to reduce the incidence of bone cement implantation syndrome in patients undergoing cemented hip arthroplasty - a randomized parallel-arm trial. BMC Anesthesiol 2018; 18:63. [PMID: 29875024 PMCID: PMC5991443 DOI: 10.1186/s12871-018-0526-4] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/23/2018] [Accepted: 05/25/2018] [Indexed: 02/08/2023] Open
Abstract
BACKGROUND The bone cement implantation syndrome (BCIS) is a frequent and potentially disastrous intraoperative complication in patients undergoing cemented hip arthroplasty. Several risk factors have been identified, however randomized controlled trials to reduce the incidence of BCIS are still pending. We hypothesized that goal-directed hemodynamic therapy guided by esophageal Doppler monitoring (EDM) may reduce the incidence of BCIS in a randomized, controlled parallel-arm trial. METHODS After approval of the local ethics committee, 90 patients scheduled for cemented hip arthroplasty at the Medical Center - University of Freiburg were randomly assigned to either standard hemodynamic management or goal-directed therapy (GDT) guided by an esophageal Doppler monitoring-based algorithm. The primary endpoint was the incidence of overall BCIS including grade 1-3 after cementation of the femoral stem. Secondary endpoints included cardiac function, length of hospital stay and postoperative complications. RESULTS Ninety patients were finally analyzed. With regards to the primary endpoint, the overall incidence of BCIS showed no difference between the GDT and control group. Compared to the control group, patients of the GDT group showed a higher cardiac index before and after bone cement implantation (2.7 vs. 2.2 [l●min- 1●m- 2]; 2.8 vs. 2.4 [l●min- 1●m- 2]; P = 0.003, P = 0.042), whereas intraoperative amount of fluids and mean arterial pressure did not differ. CONCLUSIONS The implementation of a specific hemodynamic goal-directed therapy did not reduce the overall incidence of BCIS in patients undergoing cemented hip arthroplasty. TRIAL REGISTRATION This randomized clinical two-arm parallel study was approved by the local Ethics Committee, Freiburg, Germany [EK 160/15, PI: U. Goebel] and registered in the German Clinical Trials Register ( DRKS No. 00008778 , 16th of June, 2015).
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Affiliation(s)
- Kai B Kaufmann
- Department of Anaesthesiology and Critical Care, Medical Center - University of Freiburg, Hugstetter Strasse 55, 79106, Freiburg, Germany. .,Faculty of Medicine, University of Freiburg, Freiburg, Germany.
| | - Wolfgang Baar
- Department of Anaesthesiology and Critical Care, Medical Center - University of Freiburg, Hugstetter Strasse 55, 79106, Freiburg, Germany.,Faculty of Medicine, University of Freiburg, Freiburg, Germany
| | - Judith Rexer
- Department of Anaesthesiology and Critical Care, Medical Center - University of Freiburg, Hugstetter Strasse 55, 79106, Freiburg, Germany.,Faculty of Medicine, University of Freiburg, Freiburg, Germany
| | - Thomas Loeffler
- Department of Anaesthesiology and Critical Care, Medical Center - University of Freiburg, Hugstetter Strasse 55, 79106, Freiburg, Germany.,Faculty of Medicine, University of Freiburg, Freiburg, Germany
| | - Sebastian Heinrich
- Department of Anaesthesiology and Critical Care, Medical Center - University of Freiburg, Hugstetter Strasse 55, 79106, Freiburg, Germany.,Faculty of Medicine, University of Freiburg, Freiburg, Germany
| | - Lukas Konstantinidis
- Department of Orthopaedic and Trauma Surgery, Medical Center - University of Freiburg, Freiburg, Germany.,Faculty of Medicine, University of Freiburg, Freiburg, Germany
| | - Hartmut Buerkle
- Department of Anaesthesiology and Critical Care, Medical Center - University of Freiburg, Hugstetter Strasse 55, 79106, Freiburg, Germany.,Faculty of Medicine, University of Freiburg, Freiburg, Germany
| | - Ulrich Goebel
- Department of Anaesthesiology and Critical Care, Medical Center - University of Freiburg, Hugstetter Strasse 55, 79106, Freiburg, Germany. .,Faculty of Medicine, University of Freiburg, Freiburg, Germany.
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Loeffler T, Shim MY, Beckstead RB, Batal AB, Pesti GM. Amino acid digestibility and metabolizable energy of genetically selected soybean products. Poult Sci 2013; 92:1790-8. [PMID: 23776266 DOI: 10.3382/ps.2012-02299] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
To determine the ME and amino acid digestibility of 5 soybean meal (SBM) samples, a precision-fed rooster assay and a chick assay were conducted. The 5 samples were cold-pressed (extruded) soybean meals or solvent-extracted (defatted) soybean meal. Of the cold-pressed varieties (unheated), there was an ultra-low trypsin SBM, a low-trypsin SBM, and a heated and unheated commodity SBM. The solvent-extracted SBM was a heated commodity blend. The TME and AME values were compared between each category: cold-pressed and defatted, as well as between the 2 assays. Semipurified diets containing dextrose as the main energy source were formulated to meet the bird's nutrient requirements, with each diet containing a different SBM product. The TME rooster assay was a precision-fed rooster assay in which 5 birds per diet were fasted for 24 h, crop intubated with 35 g of the test diet containing 46.58% cold-pressed or defatted SBM, and excreta was then collected for 48 h. The total aromatic amino acids rooster assay followed the same protocol, but cecectomized birds were used. For the chick assay, 480 one-day-old chicks were fed a standard corn-SBM starter diet until 17 d of age, and on d 18, the chicks were allowed ad libitum access to the SB-dextrose diets. Excreta were collected on d 22, dried, ground, and analyzed for gross energy and CP to determine ME. The SBM samples that were genetically selected to have lower trypsin inhibitor levels and higher protein had higher ME values and increased amino acid digestibility than the commodity cold-pressed SBM samples. Genetic selection of soybeans for certain traits can have positive effects on the ME value and amino acid digestibility for roosters and chicks.
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Affiliation(s)
- T Loeffler
- Department of Poultry Science, the University of Georgia, Athens, GA, USA
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