Biomedical Engineering: Purdue School of Engineering and Technology, IUPUI

Department of Biomedical Engineering

Xiaomei Guo, M.D.
Assistant Research Professor,
Biomedical Engineering Department

Contact:
635 Barnhill Drive, MS 2065
Indianapolis, IN 46202
(317) 274-8332
guo2@iupui.edu

Education:
M.S. Medical Sciences (July 1997)
M.D. Clinical Medicine (July 1994)

Postdoctoral training:
Department of Biomedical Engineering, University of California, Irvine, CA, USA (Oct 2001 - June 2006)
Department of Bioengineering, University of California, San Diego, CA, USA (Aug 2000 - Sept 2001)

Research area : arterial biomechanical and structural properties in different animal models

The assessment of arterial mechanical and structural properties is particularly important in understanding the mechanism of cardiovascular risk factors such as aging, hypertension, diabetes, hyperlipidemia, atherosclerosis, heart failure and smoking. We have been working on the mechanical properties of the cardiovascular system in animal models. We found that the residual circumferential strain leads to a uniformity of transmural strain of the aorta in the loaded state along the entire length of the aorta in a mouse model. We also determined the distribution of circumferential stress and strain along the aorta and throughout the coronary arterial tree in the pig model in order to test this hypothesis. Meanwhile, our group examined the effects of estrogen deficiency and acute estrogen-induced vasodilation on the biomechanical properties of carotid and femoral artery in ovariectomized mice and in the transgenic model and try to explain the mechanisms of arterial remodeling. We found statistically significant correlations between the structural (wall thickness), mechanical (stress, strain, elastic modulus) and biochemical parameters (nitric oxide byproducts). The mechanism of endogenous estrogen effect on the arterial mechanical properties is related to the regulation of nitric oxide (NO) derived from endothelial NO synthase (eNOS). Recently, our group started to work on a new smoking mouse model. We examined the long-term and short-term effects of cigarette smoking on biomechanical properties of coronary artery and aorta in mice and tried to determine the mechanisms of coronary remodeling in response to the mechanic stimuli. We demonstrated cigarette smoking has an immediate and substantial effect on structural and elastic properties of mouse coronary arteries which highly correlated with a decrease in NO bioavailability. Moreover, long-term cigarette smoking exposure can cause an irreversible deterioration of structural and elastic properties of coronary arteries.

Laboratory research and experimental methodologies

Anatomical, physiological and mechanical characterization of cardiovascular system and the creation of animal models by using surgical and microsurgical skills under microscope on animals.
Morphological and structural characterization of cardiovascular system by using pathological embedding techniques (JB-4 and paraffin embedding), various section and staining techniques.
Measurement of biomarkers such as various enzymes and nitric oxide byproducts by using Western blotting, immunohistochemistry, immunofluorescence and high-performance liquid chromatography techniques.

Selected Publications:

Guo X, Lu X, Ren H, Levin ER, Kassab GS. Estrogen Modulates the Mechanical Homeostasis of Mouse Arterial Vessels through Nitric Oxide. Am J Physiol Heart Circ Physiol. 290(5):H1788-97, 2006.

Guo X, Razandi M, Pedram A, Kassab GS, Levin ER. Estrogen Induces Vascular Wall Dilation: Mediation through Kinase Signaling to Nitric Oxide and Estrogen Receptors α and β. J Biol Chem. 280(20): 19704 -19710, 2005.

Guo X, Lu X, Kassab GS. The Transmural Strain Distribution in the Blood Vessel Wall. Am J Physiol Heart Circ Physiol. 288(2): H881-H886, 2005.

Guo X and Kassab GS. Distribution of stress and strain along the aorta and coronary arterial tree. Am J Physiol Heart Circ Physiol. 286: H2361-H2368, 2004.

Guo X and Kassab GS. Variation of mechanical properties along the aorta in C57bl/6 mice. Am J Physiol Heart Circ Physiol. 285: H2614-H2644, 2003.

Guo X, Kono Y, Mattrey Y, Kassab GS. Morphometry and strain distribution of the C57BL/6J mouse aorta. Am J Physiol Heart Circ Physiol. 283: H1829-H1837, 2002.