During sepsis, defined as life-threatening organ dysfunction due to dysregulated host response to infection, systemic inflammation activates endothelial cells and initiates a multifaceted cascade of pro-inflammatory signaling events, resulting in increased permeability and excessive recruitment of leukocytes. Vascular endothelial cells share many common properties but have organ-specific phenotypes with unique structure and function. Thus, therapies directed against endothelial cell phenotypes are needed to address organ-specific endothelial cell dysfunction.
View Article and Find Full Text PDFTherapeutic hypothermia has become an accepted part of post-resuscitation care. Efforts to shorten the time from return of spontaneous circulation to target temperature have led to the exploration of different cooling techniques. Convective-immersion uses a continuous shower of 2 degrees C water to rapidly induce hypothermia.
View Article and Find Full Text PDFMild hypothermia (32-34 deg C) treatment alleviates vital organ damage after cardiac arrest. A new cooling device, the Thermosuit operates by applying of a thin layer of water directly to the body surface. Hypothermic patients may experience sequential fibrillation.
View Article and Find Full Text PDFObjective: During surface cooling with ice-cold water, safety and effectiveness of transthoracic defibrillation was assessed.
Methods: In a pig ventricular fibrillation cardiac arrest model, once (n = 6), defibrillation was done first in a dry and then in a wet condition using the ThermoSuit System (Life Recovery Systems, HD, LLC, Kinnelon, NJ), which circulates a thin layer of ice-cold water (approximately 4 degrees C) over the skin surface. Another time (n = 6), defibrillation was done first in a wet and then in a dry condition.
Fractal analysis of bone X-ray images has received much interest recently for the diagnosis of bone disease. In this paper, we propose a fractal analysis of bone X-ray tomographic microscopy (XTM) projections. The aim of the study is to establish whether or not there is a correlation between three-dimensional (3-D) trabecular changes and two-dimensional (2-D) fractal descriptors.
View Article and Find Full Text PDFTrabecular bone microarchitecture and bone mineral density (BMD) are two main factors related to osteoporotic fractures. Currently, however, microarchitecture is not evaluated. We have developed and validated a trabecular bone texture analysis from radiographic images.
View Article and Find Full Text PDFBackground: To test whether later intra-aortic balloon pump (IABP) deflation approaching or simultaneous with left ventricular ejection would improve hemodynamics and myocardial efficiency with the use of new balloon deflation methods, 4 IABP timing techniques were evaluated in 43 patients.
Methods And Results: Later balloon deflation produced significantly greater percentage changes in mean aortic pressure (6% vs 1%), systolic pressure time index (-27% vs -20%), diastolic pressure time index (35% vs 19%), and the systolic pressure-time index/diastolic pressure-time index ratio (97% vs 51%), respectively. However, these changes increased peak systolic pressure (-15% vs -11%).
Percutaneous placement of an intra-aortic balloon (IAB) through a femoral artery of a patient is associated with a risk of reduction of blood flow distal to the balloon insertion site. If this reduction is severe, it ultimately causes limb ischemia and necessitates IAB removal. Although clinicians intuitively know that larger catheters cause higher flow restrictions, very few studies have examined this situation quantitatively.
View Article and Find Full Text PDFThe relationship between bone strength and bone mass is well established. The link between trabecular microarchitecture and biomechanical properties has been less extensively explored. To address this question, we have tested the mechanical behaviour of calcaneus bone samples and investigated the correlations between mechanical properties on the one hand, bone density and fractal analysis of microarchitecture on the other hand.
View Article and Find Full Text PDFJ Bone Miner Res
December 1994
Bone density is not the unique factor conditioning bone strength. Trabecular bone microarchitecture also plays an important role. We have developed a fractal evaluation of trabecular bone microarchitecture on calcaneus radiographs.
View Article and Find Full Text PDFIEEE Trans Med Imaging
October 2012
Fractals have been shown to be useful in characterizing texture in a variety of contexts. Use of this methodology normally involves measurement of a parameter H, which is directly related to fractal dimension. In this work the basic theory of fractional Brownian motion is extended to the discrete case.
View Article and Find Full Text PDFIEEE Trans Biomed Eng
October 1985
A computer based model for in-series cardiac assistance by intraaortic balloon pumping was developed in this study. The model, obtained from the Navier-Stokes and Continuity equations, was capable of computing pressures, volumetric flow rates and radii through the arterial system. The model was used to study the effects of a wide range of assist device timing adjustments on the benefits of ventricular assistance under conditions corresponding to those measured during animal experiments.
View Article and Find Full Text PDFIEEE Trans Biomed Eng
January 1983
A pressure system externally applied to the limbs of a patient has been proven effective in assisting circulation in animal and clinical studies. In this study a nonlinear mathematical model of the cardiovascular system is utilized to determine the effectiveness of high-frequency components in the external pressure waveform. The development of the model, the method of analysis, and the results acquired with the model are presented in this report, demonstrating its suitability for the study of external counterpulsation.
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