Cardiovascular Ultrasound Machine for SHS/THS Exposure Core
Creators: name: University Of California Office Of The President
Publisher: name: University of California Office of the President
publisherIdentifier: https://ror.org/00dmfq477
publisherIdentifierScheme: ROR
Year: 2024

description: The Secondhand (SHS) and Thirdhand (THS) Cigarette Smoke Human Exposure Core, at the Human Exposure Laboratory at the University of California, San Francisco is a unique and valuable facility that benefits tobacco-related disease researchers throughout California. The purchase of a dedicated cardiovascular ultrasound machine and the support and training of a cardiovascular ultrasound technician for the SHS and THS Human Exposure Core, will significantly increase productivity and throughput allowing us to serve more tobacco-related disease researchers in California. We use the cardiovascular ultrasound machine to measure flow-mediated dilation of the brachial artery (FMD). FMD is a test of the ability of the main artery that supplies the arm to dilate in response to a surge in blood flow; the measured FMD is a marker of endothelial function. Decreased FMD is associated with increased risk of cardiovascular morbidity and mortality. At this time, we are only able to do 1-2 exposure experiments per month and must schedule time with the cardiovascular ultrasound technicians1-3 months in advance. A dedicated GE Vivid E9 cardiovascular ultrasound machine in our lab, with training and support for a dedicated FMD technician will allow us to double or triple the number of experiments we can do in a year. At this time, the UCSF Human Exposure Laboratory is performing some of the most carefully-controlled, well-characterized clinical research on SHS and THS exposure in the world. Our research has shown that a 30 minute exposure to SHS has health effects that last for over 24 hours and that for each increase in SHS exposure by 100 ?g/m3 respirable suspended particles (RSP), the absolute % FMDmax is reduced by 0.67%. FMD is the most sensitive physiological measure we have and has come to function as a positive control for our cardiovascular and pulmonary studies. Our current studies focus on the mechanisms by which SHS exposure decreases FMD. Studying human subjects allows us to avoid the uncertainty inherent in projecting the relevance of vitro and animal research findings to human health outcomes. Our collaborations with tobacco chemists and combustion engineers help us identify target compounds and chemical reactions for further research as SHS and THS biomarkers. Other researchers have shown that nicotine from SHS can deposit on paper surfaces and react to form a tobacco-specific nitrosamine known as NNA. Our data have shown that paper that has been exposed to SHS for longer periods of time does not have NNA, but NNK, a more carcinogenic nitrosamine. Through careful control of exposure conditions, we can also accurately measure exposure and uptake of specific toxins in secondhand and thirdhand smoke by human subjects. These exposure data, in turn, inform in vitro and animal research done by other tobacco-related disease researchers in California. Our focus on the effects of brief, realistic exposures also means that our data have immediate value for tobacco control advocates and policy makers. The purchase of a GE Vivid E9 cardiovascular ultrasound machine will allow us to expand our operations so that we can serve as a core facility for researchers throughout California.