Featured Member Archives
Meet Travis Doggett, Ph.D. recipient of the 2016 August Krogh Young Investigator Award
The current research interest of Dr. Doggett (University of South Florida) focuses on microvascular permeability following hemorrhagic shock/trauma combined with acute alcohol intoxication. Binge drinking is a serious problem in the United States, producing $223.5 billion in healthcare costs. Nearly 40% of injured patients admitted to the emergency room have intoxicating blood alcohol concentrations. Intoxicated trauma patients exhibit aggravated hemodynamic instability following hemorrhage, are significantly more hypotensive, and require greater volumes of resuscitation fluids compared to non-intoxicated patients. His lab has demonstrated that acute alcohol intoxication causes microvascular hyperpermeability in the mesenteric microcirculation of rats. More recent work has investigated microvascular permeability following a fixed-pressure hemorrhage combined with acute alcohol intoxication. We hypothesize that the loss of central fluid volume due to elevated hyperpermeability is directly responsible for the potentiated hypotension exhibited by intoxicated trauma patients. Currently, we are investigating methods to enhance the microvascular barrier and attenuate hyperpermeability following hemorrhage. The August Krogh Young Investigator Award is named in honor of microcirculatory scientist August Krogh, who received the Nobel Prize in 1920 for the first descriptions of blood flow control through capillaries and arterioles based on tissue oxygen demand, this annual award is intended for a graduate student or a Ph.D./M.D. in the early stages of a research career. This award is presented to encourage excellence in microcirculatory research by new, young investigators.
Meet Zhichao Fan, Ph.D. of the La Jolla Institute for Allergy and Immunology
One of Dr. Fan’s research interests is focusing on studying the mechanisms of leukocyte rolling and arrest during inflammation in the microcirculation. Dr. Fan exploited microfluidics with molecularly defined surfaces and high resolution three-color total internal reflection microscopy to imaging the molecular dynamics during leukocyte rolling and arrest under high resolution in vitro, and using intravital microscopy to study leukocyte rolling and arrest in vivo. Adhesion molecules such as integrins were mainly focused.Another research interest of Dr. Fan, is monitoring rare circulating cells, such as circulating tumor cells, in microcirculation using in vivo flow cytometry.
Dr. Steven Segal Named the 2016 Landis Awardee
Professor Steven Segal received his B.A. and M.A. degrees in Physical Education and Exercise Physiology from the University of California at Berkeley followed by a dual Ph.D. in Kinesiology and Physiology from the University of Michigan. He then undertook postdoctoral training at the University of Virginia in the laboratory of Dr. Brian Duling. After serving on the faculty of the Noll Human Performance Laboratory at Pennsylvania State University, Dr. Segal moved to Yale School of Medicine where he rose through the academic ranks to tenured Professor in Cellular and Molecular Physiology. He then moved to the Department of Medical Pharmacology and Physiology at the University of Missouri-Columbia, where he currently holds the title of Margaret Proctor Mulligan Professor in Medical Research. Dr. Segal is also an Investigator in the Dalton Cardiovascular Research Center.
With over three decades in microcirculation research, Professor Segal has built an international reputation for his foundational work on the local control of blood flow, particularly with respect to the roles of microvascular endothelium, vascular smooth muscle and perivascular nerves in the moment-to-moment control of blood flow in resistance networks. His work on underlying mechanisms and functional consequences of cell-to-cell communication in the vascular wall has provided new insight into our understanding of how local blood flow is coupled to tissue metabolic demand. Dr. Segal's work is valued by his peers for its rigor and technical innovation. Over the years his laboratory has developed powerful new approaches to resolve the cellular and subcellular processes involved in the microvascular control of blood flow and oxygen delivery with an emphasis on skeletal muscle during exercise.
Professor Segal is the author/co-author of over 100 peer-reviewed articles and more than 20 invited reviews and book chapters. He serves as Reviewing Editor for the Journal of Physiology and has served as Associate Editor for Microcirculation. He is on the editorial board of several other leading journals, including the American Journal of Physiology: Heart and Circulatory Physiology and the Journal of Vascular Research.
Professor Segal has also served on numerous study sections and review groups for the NIH and other funding agencies. His own research has been funded continuously by the NIH for over 30 years, culminating in a prestigious MERIT Award that extends into 2019. Throughout his career, Dr. Segal has been an active and engaged member of scientific societies. He served the Microcirculatory Society in several capacities including President, as a member of Executive Council and as a member and chair of MCS committees. Dr. Segal is also an Established Investigator of the American Heart Association, a Fellow of the American College of Sports Medicine, a Fellow of the AHA Council on Basic Cardiovascular Sciences, and a Fellow of the American Physiological Society Cardiovascular Section. Dr. Segal has received prestigious scientific awards, including the MCS Outstanding Young Investigator Travel Award, the Abbott Microcirculation Award from the European Society for Microcirculation, and the Malpighi award, also from the ESM. Professor Segal's dedication to microvascular research is embodied in his mentoring of the students and postdoctoral fellows who have in turn become successful independent investigators, academicians and clinicians.
D. Neil Granger, 2015 Benjamin W. Zweifach Award Recipient
Cam Ha Tran, University of Calgary
In addition, she had the idea to implement a tail artery cannula in the mouse to perfuse agents of interest, plus a fluorescent dye, into the systemic circulation so that we might image the arrival of drugs to the brain. This technique works surprisingly well and is part of her published protocol paper.
Cam Ha's first publication as a first author (co-authored by Dr. Gordon) was published in Frontiers Cellular Neuroscience. Her manuscript detailed how one can achieve sub-cellular level imaging of the brain of fully behaving mice, while also minimizing animal stress. Cam Ha demonstrates how behavioral data can be captured simultaneously with two-photon fluorescence signals. She also shows other possible applications of this technique by 1) monitoring dynamic changes to blood flow in response to sensory stimulation and 2) measuring Ca2+ signals from synthetic and genetically encoded Ca2+ indicators in astrocytes. The method she developed will facilitate acute two-photon fluorescence imaging in awake, active mice and help link cellular events within the brain's microcirculation to whole animal behavior.
In another project, she demonstrates the role of astrocytes in brain blood flow control. In vitro data clearly shows that Ca2+ elevations in astrocytes influence blood vessel diameter, yet in vivo data fails to observe such astrocyte Ca2+ signals during functional increases in blood flow. Notably, the in vivo data is collected under anesthesia or sedation, which reduces astrocyte Ca2+ signaling. Cam Ha's data clearly shows robust spontaneous and evoked astrocyte Ca2+ signals in her awake mouse preparation.
"The contractile activity of vascular smooth muscle cells is critical to the ability of small arteries to regulate blood flow in response to fluctuations in intraluminal pressure (the "Myogenic Response")." In regard to this, I am interested in the mechanotransduction processes which underlie how smooth muscle cells sense and respond to mechanical forces. In particular, whether the angiotensin II type 1 receptor (AT1R) can act as a mechanosensor in resistance arterioles and contribute to myogenic responsiveness. An additional interest relates to whether pressure-dependent vasoconstriction is modulated by negative regulation of AT1R signaling by RGS (Regulators of G-protein Signaling) proteins under physiological and pathophysiological conditions." Kwangseok is a recipient of a 2015 MCS Zweifach Student Travel Award.
Evandro M. Neto Neves, Indiana University
Kerri-Ann Norton, Ph.D., Johns Hopkins School of Medicine