The Experts below are selected from a list of 231 Experts worldwide ranked by ideXlab platform
Peter Vaupel - One of the best experts on this subject based on the ideXlab platform.
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vascularity Perfusion Rate and local tissue oxygenation of tumors derived from rus transformed fibroblasts
International Journal of Cancer, 2007Co-Authors: F. Kaixinowski, R. Wilkerson, Richard E. Moore, W. Strauss, Peter VaupelAbstract:Tumors derived from ras-transformed rat fibroblasts were investigated in order to gain insight into possible interrelationships between oncogenic transformations and therapeutically relevant parameters of the metabolic micromilieu of solid tumors in vivo. Tumors grew in nude mice after injection of in vitro-passaged cells. Growth Rates, early stages of angiogenesis, Perfusion and tissue oxygenation were assessed. Compared with the parental cell line, both ras transformants grew very rapidly and exhibited an early onset of angiogenesis. Perfusion Rates of one ras-transformed tumor line were similar to those of the parental tumors whereas reduced flow values were detected in tumors of the other rats line. The better perfused tumors exhibited more adequate tissue oxygen levels whereas reduced oxygen levels were obvious in the poorly perfused ras line. These results indicate that ras transformation alters therapeutically relevant parameters of the tumor micromilieu. However, the tumor phenotype cannot be predicted even if the transforming oncogene is known.
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Vascularity, Perfusion Rate and local tissue oxygenation of tumors derived from rus‐transformed fibroblasts
International journal of cancer, 1991Co-Authors: F. Kaixinowski, R. Wilkerson, Richard E. Moore, W. Strauss, Peter VaupelAbstract:Tumors derived from ras-transformed rat fibroblasts were investigated in order to gain insight into possible interrelationships between oncogenic transformations and therapeutically relevant parameters of the metabolic micromilieu of solid tumors in vivo. Tumors grew in nude mice after injection of in vitro-passaged cells. Growth Rates, early stages of angiogenesis, Perfusion and tissue oxygenation were assessed. Compared with the parental cell line, both ras transformants grew very rapidly and exhibited an early onset of angiogenesis. Perfusion Rates of one ras-transformed tumor line were similar to those of the parental tumors whereas reduced flow values were detected in tumors of the other rats line. The better perfused tumors exhibited more adequate tissue oxygen levels whereas reduced oxygen levels were obvious in the poorly perfused ras line. These results indicate that ras transformation alters therapeutically relevant parameters of the tumor micromilieu. However, the tumor phenotype cannot be predicted even if the transforming oncogene is known.
Xiaogeng Tian - One of the best experts on this subject based on the ideXlab platform.
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Investigation of transient thermo-mechanical responses on the triple-layered skin tissue with temperature dependent blood Perfusion Rate
International Journal of Thermal Sciences, 2019Co-Authors: Zhang-na Xue, Xiaogeng TianAbstract:Abstract A large number of studies indicate that blood Perfusion Rate in biological tissue cannot be regarded as a constant in burn and thermal therapy analysis. This provides us a motivation to investigate the transient responses in the context of generalized bio-thermoelastic theories with temperature dependent blood Perfusion Rate. It is difficult to obtain the analytical solutions of nonlinear governing equations due to the consideration of variable blood Perfusion Rate. In present work, the finite element control equations of skin tissue based on generalized bio-thermoelasticity are derived and the nonlinear thermoelastic responses of the triple-layered skin tissue are obtained in time-domain directly. The influences of variable blood Perfusion Rate on the responses are discussed and illustRated graphically.
Min Choi - One of the best experts on this subject based on the ideXlab platform.
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tissue Perfusion Rate estimation with compression based photoacoustic ultrasound imaging erratum
Journal of Biomedical Optics, 2018Co-Authors: Min Choi, A James M Shapiro, Roger J ZempAbstract:This erratum corrects errors with the figure citations in https://doi.org/10.1117/1.JBO.23.1.016010.
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Tissue Perfusion Rate estimation with compression-based photoacoustic-ultrasound imaging.
Journal of Biomedical Optics, 2018Co-Authors: Min Choi, A. M. James Shapiro, Roger Josef ZempAbstract:Tissue Perfusion is essential for transporting blood oxygen and nutrients. Measurement of tissue Perfusion Rate would have a significant impact in clinical and preclinical arenas. However, there are few techniques to image this important parameter and they typically require contrast agents. A label-free methodology based on tissue compression and imaging with a high-frequency photoacoustic-ultrasound system is introduced for estimating and visualizing tissue Perfusion Rates. Experiments demonstRate statistically significant differences in depth-resolved Perfusion Rates in a human subject with various temperature exposure conditions.
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Perfusion-Rate estimation using compression-based photoacoustic-ultrasound imaging
2017 IEEE International Ultrasonics Symposium (IUS), 2017Co-Authors: Min Choi, Roger Josef ZempAbstract:The ability to measure Perfusion Rates of tissues in a non-invasive and label-free way could enable powerful diagnostic applications to peripheral vascular disease, ischemia, tumor hypoxia, ulcer characterization, and general tissue health. However, current medical techniques of measuring Perfusion Rates, which include contrast-enhanced ultrasound imaging, Perfusion MR imaging require contrast agents and thus are not amenable to widespread screening procedures. A crude method of measuring net limb Perfusion is measuring the capillary refill time (CRT) using a compression nail test performed in an emergency ward or a pediatric care. Yet, the test itself does not have a set standard as CRT is highly variable depending on patient status. This method also does not provide local maps of tissue Perfusion. Our approach of measuring Perfusion Rates using combined photoacoustic and ultrasound imaging is a non-invasive method and may be suitable for high throughput mapping of Perfusion Rates in deep tissue (∼2 mm).
Liewen Pang - One of the best experts on this subject based on the ideXlab platform.
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Simultaneous measurements of local tissue temperature and blood Perfusion Rate in the canine prostate during radio frequency thermal therapy.
Biomechanics and modeling in mechanobiology, 2005Co-Authors: Liang Zhu, Liewen PangAbstract:Local tissue temperature and blood Perfusion Rate were measured simultaneously to study thermoregulation in the canine prostate during transurethral radio-frequency (RF) thermal therapy. Thermistor bead microprobes measured interstitial temperatures and a thermal clearance method measured the prostatic blood Perfusion Rate under both normal and hyperthermic conditions. Increase in local tissue temperature induced by the RF heating increased blood Perfusion throughout the entirety of most prostates. The onset of the initial increase in blood Perfusion was sometimes triggered by a temporal temperature gradient at low tissue temperatures. When tissue temperature was higher than 41°C, however, the magnitude and the spatial gradient of temperature may play significant roles. It was found that the temperature elevation in response to the RF heating was closely coupled with local blood flow. The resulting decrease in or stabilization of tissue temperature suggested that blood flow might act as a negative feedback of tissue temperature in a closed control system. Results from this experiment provide insights into the regulation of local Perfusion under hyperthermia. The information is important for accuRate predictions of temperature during transurethral RF thermal therapy.
Roger Josef Zemp - One of the best experts on this subject based on the ideXlab platform.
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Tissue Perfusion Rate estimation with compression-based photoacoustic-ultrasound imaging.
Journal of Biomedical Optics, 2018Co-Authors: Min Choi, A. M. James Shapiro, Roger Josef ZempAbstract:Tissue Perfusion is essential for transporting blood oxygen and nutrients. Measurement of tissue Perfusion Rate would have a significant impact in clinical and preclinical arenas. However, there are few techniques to image this important parameter and they typically require contrast agents. A label-free methodology based on tissue compression and imaging with a high-frequency photoacoustic-ultrasound system is introduced for estimating and visualizing tissue Perfusion Rates. Experiments demonstRate statistically significant differences in depth-resolved Perfusion Rates in a human subject with various temperature exposure conditions.
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Perfusion-Rate estimation using compression-based photoacoustic-ultrasound imaging
2017 IEEE International Ultrasonics Symposium (IUS), 2017Co-Authors: Min Choi, Roger Josef ZempAbstract:The ability to measure Perfusion Rates of tissues in a non-invasive and label-free way could enable powerful diagnostic applications to peripheral vascular disease, ischemia, tumor hypoxia, ulcer characterization, and general tissue health. However, current medical techniques of measuring Perfusion Rates, which include contrast-enhanced ultrasound imaging, Perfusion MR imaging require contrast agents and thus are not amenable to widespread screening procedures. A crude method of measuring net limb Perfusion is measuring the capillary refill time (CRT) using a compression nail test performed in an emergency ward or a pediatric care. Yet, the test itself does not have a set standard as CRT is highly variable depending on patient status. This method also does not provide local maps of tissue Perfusion. Our approach of measuring Perfusion Rates using combined photoacoustic and ultrasound imaging is a non-invasive method and may be suitable for high throughput mapping of Perfusion Rates in deep tissue (∼2 mm).