Removal of cholesterol and other lipids from experimental animal and human atheromatous arteries by dilute hydrogen peroxide

Immobilization of R. erythropolis in alginate-based artificial cells for simulated plaque degradation in aqueous media

Cholesterol degradation rates of free and immobilized Rhodococcus erythropolis (ATCC # 25544) were studied utilizing the bacterium's cholesterol oxidase enzyme pathway to degrade cholesterol in an aqueous simulated non-calcified plaque solution. An L16 (4(5)) Taguchi design was used to minimize the glycolipid bio-surfactant by-product in the growth medium, to improve bacterial viability in the immobilized state. As an expected outcome of miniaturization, there is a significant difference between the atomized (d = 850 ± 50 μm) and inkjet-bioprinted (d = 32 ± 5 μm) lumped kinetic degradation rates after 48 h (p = 0.029, α = 0.05) per ml of jetted alginate. Based on a biphasic cholesterol degradation model, at an initial bacterial cell density of Nlow = 4.53 × 10(8)/ml, for an initial cholesterol concentration of 3 mg/ml, the percentage mass of metabolite degraded is 37.0% ± 0.42%, 57.8% ± 0.04% and 65.1% ± 0.01% for the free, atomized and inkjet immobilized bacteria, respectively.

Non-ischemic hypoxia of the arterial wall is a primary cause of atherosclerosis

The response-to-injury hypothesis has been the dominant model of atherosclerosis for 20 years. However, it does not explain the experimental role of oxygen in atherogenesis, does not explain many of the clinical features of atherosclerosis, and has failed to provide useful countermeasures. I propose that arterial wall hypoxia results from risk factors for atherosclerosis. The primary mechanism is decreased oxygen delivery by a microcirculatory derangement resulting from impaired erythrocyte deformability. As in a healing wound, hypoxia causes growth factor release within the arterial media. Diffusion of these factors causes intimal proliferation and atheroma formation. This hypothesis implies that simple inexpensive oxygenation regimens might prevent the morbidity and mortality of atherosclerosis. Despite demonstrated effectiveness in experimental models, such treatments have not been extensively studied in clinical atherosclerosis because they conflict with the dominant model. This dogma needs to be re-examined.

Contrast echocardiography

Contrast echocardiography is the technique of injecting an echo-producing, biologically compatible solution into the bloodstream and using M-mode and/or two-dimensional echocardiography to observe intracardiac bloodflow patterns revealed by the resulting cloud of echoes. This information was previously available only from angiocardiography. Contrast echocardiography has become a well-established adjunct to M-mode and two-dimensional echocardiographic examination and is valuable in the identification and validation of normal and abnormal cardiac structures, for the demonstration (and exclusion) of intracardiac as well as extracardiac shunts, and in the diagnosis of valvular regurgitation. In addition many clinical applications are being developed. Future research directions include development of videodensitometric techniques for contrast quantitation, finding contrast agents capable of passing the lung capillary bed and measurement of right heart pressures using microbubble resonance techniques.