1,722,527 research outputs found
Focus on anti-atherosclerotic therapy
Calcium antagonists (CA) exert an anti-atherosclerotic effect in cholesterol-fed rabbits through reduction of cholesterol accumulation in the arterial wall. Further studies in our Institute indicate that verapamil-like compounds and diltiazem stimulate receptor-mediated LDL uptake by human fibroblasts in culture, while nifedipine-like compounds and flunarizine are inactive. Verapamil and diltiazem stimulated LDL-receptor activity also in cells from a heterozygous FH patient, while they were inactive in a receptor defective homozygous FH patient. A basic group needs to be present on the CA molecule to modulate the LDL receptor expression. Preliminary data in our laboratory suggest that some CA can achieve concentrations in the aortic wall likely to exert effects on LDL receptors. This stimulatory activity may improve lipid metabolism in the arterial wall
Silicon photomultipliers in Very High Energy gamma-ray astrophysics
In the last ten years silicon photomultipliers (SiPMs) have gained terrain in experiments and applications in which photomultiplier tubes have been the dominant photosensors during decades. Imaging Atmospheric Cherenkov Telescopes (IACTs) for very high energy (VHE, E>50 GeV) gamma-ray astronomy are experiencing the same process. Until now FACT was the only IACT using SiPMs. In the Cherenkov Telescope Array (CTA), the next-generation VHE gamma-ray observatory, at least 70 telescopes equipped with SiPMs are planned to be built. The first prototypes have already been constructed and are now being commissioned. Here we discuss some of the advantages and drawbacks of using SiPMs in VHE gamma-ray astronomy and provide a brief overview of different developments related to the use of SiPMs in IACTs. © 2020 IOP Publishing Ltd and Sissa Medialab
Calcium antagonists and intimal cell proliferation in atherogenesis
Smooth muscle cell (SMC) migration and initimal proliferation are major events in the formation of the atherosclerotic lesions. Among other processes, calcium may participate in atherogenesis by affecting SMC proliferation. Calcium antagonists, which possess antiatherosclerotic properties in animal models, are effective in inhibiting SMC proliferation. This effect has been demonstrated both in vitro in cell culture and in vivo in balloon-catheterised rats and rabbits. Such an effect, indicates a possible mechanism involved in the antiatherosclerotic activity elicited by this category of drugs
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