Adaptive Bayesian regularized cardiac strain imaging (ABR-CSI) uses raw radiofrequency signals to estimate myocardial wall contractility as a surrogate measure of relative tissue elasticity incorporating regularization in the Bayesian sense. We determined the feasibility of using ABR-CSI -derived strain for in vivo longitudinal monitoring of cardiac remodeling in a murine ischemic injury model (myocardial infarction [MI] and ischemia-reperfusion [IR]) and validated the findings against ground truth histology. We randomly stratified 30 BALB/CJ mice (17 females, 13 males, median age = 10 wk) into three surgical groups (MI = 10, IR = 12, sham = 8) and imaged pre-surgery (baseline) and 1, 2, 7 and 14 d post-surgery using a pre-clinical high-frequency ultrasound system (VisualSonics Vevo 2100).
View Article and Find Full Text PDFAn adaptive Bayesian regularized cardiac strain imaging (ABR-CSI) algorithm for in vivo murine myocardial function assessment is presented. We report on 31 BALB/CJ mice (n = 17 females, n = 14 males), randomly stratified into three surgical groups: myocardial infarction (MI, n = 10), ischemia-reperfusion (IR, n = 13) and control (sham, n = 8) imaged pre-surgery (baseline- BL), and 1, 2, 7 and 14 days post-surgery using a high frequency ultrasound imaging system (Vevo 2100). End-systole (ES) radial and longitudinal strain images were used to generate cardiac fibrosis maps using binary thresholding.
View Article and Find Full Text PDFHuman adipose-derived stem cells (hASC) are now a prevalent source of adult stem cells for studies in tissue engineering and regenerative medicine. However, researchers utilizing hASC in their investigations often encounter high levels of donor-to-donor variability in hASC differentiation potential. Because of this, conducting studies with this primary cell type can require extensive resources to generate statistically significant data.
View Article and Find Full Text PDFWe have developed a novel bioreactor based on the observation that isolated porcine hepatocytes rapidly and spontaneously aggregate into spheroids under oscillation conditions. The purpose of this study was to characterize the influence of oscillation frequency (0.125 Hz, 0.
View Article and Find Full Text PDFPrior studies have suggested the possibility of immune-mediated death of xenogeneic hepatocytes in a bioartificial liver (BAL) during hemoperfusion. This study was designed to elucidate how immunity may cause death of xenogeneic hepatocytes in the BAL. Healthy dogs were treated with a BAL containing hollow fiber membranes with large pores (200 nm) or small pores (400 kDa).
View Article and Find Full Text PDFBackground: We have developed a novel bioartificial liver (BAL) composed of porcine hepatocyte spheroids in a reservoir design. A semipermeable membrane is used to protect the spheroids from immune-mediated damage. This study was designed to assess the influence of membrane pore size on performance of the spheroid reservoir BAL.
View Article and Find Full Text PDFWe have previously shown that cryopreservation leads to increased apoptotic death of porcine hepatocytes intended for use in a bioartificial liver (BAL). This study was designed to determine if a broad-spectrum caspase inhibitor, IDN-1965, reduced apoptosis and increased function of cryopreserved porcine hepatocytes in static culture or in a BAL. Porcine hepatocytes were studied immediately after isolation and after 2 weeks of cryopreservation in liquid nitrogen using medium supplemented with 25 micromol/L IDN-1965 or vehicle.
View Article and Find Full Text PDFPores in the membrane of a bioartificial liver (BAL) allow it to function as a semipermeable barrier between its contents (i.e., liver cells) and components of the recipient's immune system.
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