The Experts below are selected from a list of 195 Experts worldwide ranked by ideXlab platform
K. Jane Grande-allen - One of the best experts on this subject based on the ideXlab platform.
-
Organ Culture of Porcine Mitral Valves as a Novel Experimental Paradigm
Cardiovascular Engineering and Technology, 2013Co-Authors: Nikhil Gheewala, Kelly A. Schwarz, K. Jane Grande-allenAbstract:Mitral valve diseases are prevalent disorders, but how these conditions develop is poorly understood. Organ Culture systems offer the potential to investigate valve biology and pathology in vitro . The purpose of this research was to determine whether Culture within an Organ Culture system preserves the normal valve phenotype. Porcine mitral valves Cultured for 3 weeks in an Organ Culture system ( n = 5) were characterized mechanically, biochemically and histologically and compared to freshly harvested ( n = 7) and static Culture valves (without mechanical stimulation, n = 6). The dynamic Culture system provided mechanical stimulation through physiologically relevant pressures and flow rates. The Organ Culture system maintained function and was free of contamination, but experienced an increase in regurgitant flow, over the Culture duration. The static Culture valves had lower DNA content (cellularity) and radial tensile modulus, and greater thickness and hydration compared with the fresh valves, whereas the dynamic Culture valves better preserved these characteristics. Both groups of Cultured valves had lower tensile moduli of the chordae tendineae compared to chordae from freshly harvested valves, and both groups demonstrated a reduction of glycosaminoglycans and proteoglycans, particularly hyaluronan and versican. The investigated Organ Culture system was able to maintain several aspects, but not all aspects, of normal mitral valve mechanics and microstructure. Challenges in maintaining normal forward flow likely altered the valve hemodynamics, and will require further refinement of the Organ Culture system. Nonetheless, Organ Culture systems offer considerable promise as a new experimental paradigm for studies of valve biology and pathology.
-
Design and Mechanical Evaluation of a Physiological Mitral Valve Organ Culture System
Cardiovascular Engineering and Technology, 2010Co-Authors: Nikhil Gheewala, K. Jane Grande-allenAbstract:The physiological mechanical environment of the intact mitral valve is presumed to allow mechanotransductive, cell–cell and cell-extracellular matrix (ECM) signaling, which regulates cellular remodeling of the tissue ECM composition and structure. The goal of this work was to design an Organ Culture system to mimic the mechanical aspects of this environment, which in the future should allow for investigations to probe mitral valve biology and remodeling. This flow loop Organ Culture system uses an electronically pressure-controlled bladder pump to create a range of physiological pressure pulses in a ventricular chamber gated by inflow and outflow valves. The mitral valve attachment within the system is designed to maintain proper anatomical geometry and function. The entire system is filled with a Culture medium and located within an environmental incubator to provide an appropriate environment for tissue viability. The system has been shown to accurately recreate a physiologic pressure waveform (up to 150 mmHg) and induce pulsatile flow (3 L/min), with a response time of 50 ms. In addition, the system can maintain sterility and has been used to Culture mitral valves for up to 3 weeks. This system approximately recreates the physiological mechanical environment of a mitral valve. Future experiments will validate its ability to maintain the normal structure and composition of porcine mitral valves. After validation, this Organ Culture system can be used in longer term studies of heart valve responses to stimuli such as various biochemical agents or altered hemodynamics.
Xiaolong Liu - One of the best experts on this subject based on the ideXlab platform.
-
Reconstituted Thymus Organ Culture.
Methods in molecular biology (Clifton N.J.), 2016Co-Authors: Zimu Deng, Haifeng Liu, Jinxiu Rui, Xiaolong LiuAbstract:Reconstituted thymus Organ Culture is based on fetal thymus Organ Culture (FTOC). Purified thymocyte populations, from genetically modified mice or even from other species, are Cultured in vitro with thymic lobes depleted of their endogenous thymocytes (by 2'-deoxyguanosine treatment) to form a new thymus. This potent and timesaving method is distinct from FTOC, which assesses development of unmodified thymic lobes, and reaggregate thymic Organ Culture, in which epithelial cells are separately purified before being aggregated with thymocytes.
M. Miaguchi - One of the best experts on this subject based on the ideXlab platform.
-
Human respiratory mucosa in a nonadhesive stationary Organ Culture system.
The Laryngoscope, 1991Co-Authors: Sverre K. Steinsvåg, Øystein H. Berg, M. Strand, Jan Olofsson, M. MiaguchiAbstract:Fragments of human adenoid tissue were transferred to a nonadhesive, stationary Organ Culture system. The Culture period was 40 days. In Culture, beating cilia could be observed at the surface of the fragments. Light microscopy, scanning electron microscopy, and transmission electron microscopy showed that the tissue fragments were covered by a multilayered, pseudostratified, ciliated epithelium. Beneath the epithelium was a basement membrane. At the start of the Culture period, the central parts of the fragments were dominated by lymphocytes. These lymphocytes gradually disappeared and were replaced by a collagen-containing stroma with scattered fibroblasts. The tissue fragments can be used as an Organ Culture model for normal respiratory mucosa.
Nikhil Gheewala - One of the best experts on this subject based on the ideXlab platform.
-
Organ Culture of Porcine Mitral Valves as a Novel Experimental Paradigm
Cardiovascular Engineering and Technology, 2013Co-Authors: Nikhil Gheewala, Kelly A. Schwarz, K. Jane Grande-allenAbstract:Mitral valve diseases are prevalent disorders, but how these conditions develop is poorly understood. Organ Culture systems offer the potential to investigate valve biology and pathology in vitro . The purpose of this research was to determine whether Culture within an Organ Culture system preserves the normal valve phenotype. Porcine mitral valves Cultured for 3 weeks in an Organ Culture system ( n = 5) were characterized mechanically, biochemically and histologically and compared to freshly harvested ( n = 7) and static Culture valves (without mechanical stimulation, n = 6). The dynamic Culture system provided mechanical stimulation through physiologically relevant pressures and flow rates. The Organ Culture system maintained function and was free of contamination, but experienced an increase in regurgitant flow, over the Culture duration. The static Culture valves had lower DNA content (cellularity) and radial tensile modulus, and greater thickness and hydration compared with the fresh valves, whereas the dynamic Culture valves better preserved these characteristics. Both groups of Cultured valves had lower tensile moduli of the chordae tendineae compared to chordae from freshly harvested valves, and both groups demonstrated a reduction of glycosaminoglycans and proteoglycans, particularly hyaluronan and versican. The investigated Organ Culture system was able to maintain several aspects, but not all aspects, of normal mitral valve mechanics and microstructure. Challenges in maintaining normal forward flow likely altered the valve hemodynamics, and will require further refinement of the Organ Culture system. Nonetheless, Organ Culture systems offer considerable promise as a new experimental paradigm for studies of valve biology and pathology.
-
Design and Mechanical Evaluation of a Physiological Mitral Valve Organ Culture System
Cardiovascular Engineering and Technology, 2010Co-Authors: Nikhil Gheewala, K. Jane Grande-allenAbstract:The physiological mechanical environment of the intact mitral valve is presumed to allow mechanotransductive, cell–cell and cell-extracellular matrix (ECM) signaling, which regulates cellular remodeling of the tissue ECM composition and structure. The goal of this work was to design an Organ Culture system to mimic the mechanical aspects of this environment, which in the future should allow for investigations to probe mitral valve biology and remodeling. This flow loop Organ Culture system uses an electronically pressure-controlled bladder pump to create a range of physiological pressure pulses in a ventricular chamber gated by inflow and outflow valves. The mitral valve attachment within the system is designed to maintain proper anatomical geometry and function. The entire system is filled with a Culture medium and located within an environmental incubator to provide an appropriate environment for tissue viability. The system has been shown to accurately recreate a physiologic pressure waveform (up to 150 mmHg) and induce pulsatile flow (3 L/min), with a response time of 50 ms. In addition, the system can maintain sterility and has been used to Culture mitral valves for up to 3 weeks. This system approximately recreates the physiological mechanical environment of a mitral valve. Future experiments will validate its ability to maintain the normal structure and composition of porcine mitral valves. After validation, this Organ Culture system can be used in longer term studies of heart valve responses to stimuli such as various biochemical agents or altered hemodynamics.
Zimu Deng - One of the best experts on this subject based on the ideXlab platform.
-
Reconstituted Thymus Organ Culture.
Methods in molecular biology (Clifton N.J.), 2016Co-Authors: Zimu Deng, Haifeng Liu, Jinxiu Rui, Xiaolong LiuAbstract:Reconstituted thymus Organ Culture is based on fetal thymus Organ Culture (FTOC). Purified thymocyte populations, from genetically modified mice or even from other species, are Cultured in vitro with thymic lobes depleted of their endogenous thymocytes (by 2'-deoxyguanosine treatment) to form a new thymus. This potent and timesaving method is distinct from FTOC, which assesses development of unmodified thymic lobes, and reaggregate thymic Organ Culture, in which epithelial cells are separately purified before being aggregated with thymocytes.