Ann Schreihofer, Ph.D.
Recipient of the Bridge Grant Award
“Identifying Mechanisms and Treatments for Obesity-related Deficits in Cardiovascular Regulation and Cognition”
Bio: Dr. Schreihofer’s lab studies how the brain and autonomic nervous system contributes to the regulation of blood pressure in healthy and disease states using rodent models of hypertension, obesity, and chronic intermittent hypoxia. She recently showed how pre-diabetic elevation of blood glucose in young adult male obese Zucker rats impairs short-term regulation of blood pressure by baroreflexes, which increases the variability of blood pressure and risk of stroke. At this age, fasting blood glucose is still normal, but treatments to normalize elevated glucose with access to food provide significant improvement in the control of blood pressure, highlighting the importance of re-assessing benchmarks for initiation of treatments. In contrast, as seen with pre-menopausal obese women, young adult female obese Zucker rats maintain normal glucose levels, and later development of impaired baroreflexes occurs by other mechanisms. These studies highlight important sex differences in the development of disease states and illustrate that seemingly similar deficits may occur by different mechanisms that require distinct treatments in males and females. Recently, Dr. Schreihofer’s lab has begun studies to examine how obesity and metabolic syndrome contribute to development of cognitive decline. In a 2024 publication, her lab showed time courses for development of histological markers in specific brain regions associated with dementia along with the onset of deficits in spatial learning and memory in male obese Zucker rats.
Current Project: The goal of our ongoing research is to determine which traits of metabolic syndrome coincide with the development of dementia-related neuronal changes within the brain and impaired learning and memory in males and whether females are protected from these changes in early stages of metabolic syndrome. We aim to determine whether early treatment of elevated blood glucose in males will prevent or delay onset of these dementia-related changes to highlight the importance of reevaluating the threshold for initiation of treatment and using a holistic approach to assessing and treating traits of metabolic, cardiovascular, and cognitive functions.
Caroline Rickards, PhD
Recipient of the Bridge Grant Award
“Pulsatile Perfusion Therapy: Advancing Oscillatory Blood Flow as a Therapeutic Approach to Treat Cerebral Ischemia and Hypoxia”
Bio: Dr. Caroline Rickards is a Professor in the Department of Physiology & Anatomy at the University of North Texas Health Science Center (UNTHSC) in Fort Worth, Texas in the USA. Dr. Rickards is originally from Australia, and she received her PhD from RMIT University in Melbourne. She was a postdoctoral fellow at the US Army Institute for Surgical Research, and a Research Assistant Professor at the University of Texas at San Antonio before joining UNTHSC in 2012. Dr. Rickards, and her trainees in the Cerebral & Cardiovascular Physiology Laboratory, focus on the regulation of brain blood flow and oxygenation during stressors that challenge cerebral perfusion such as traumatic hemorrhage, cardiac arrest, and stroke. Her team has a unique translational approach to this research, employing both human and animal models of cerebral hypoperfusion, and developing novel interventions to treat these conditions. This work has been supported by grants from the American Heart Association, the US Department of Defense, and the National Institutes of Health. Dr. Rickards is a Fellow of the American Physiological Society (APS), and is Chair of the Cerebrovascular Research Network (CARNet).
Current Project: We have invented a novel therapeutic approach called Pulsatile Perfusion Therapy that shows promise in protecting the brain from acute hypoperfusion (e.g., with blood loss, stroke, and cardiac arrest). Pulsatile Perfusion Therapy applies pulsatile pressure to the lower body at 0.1 Hz (10-s cycle), inducing oscillations in arterial pressure and blood flow at the same frequency. Under conditions of acute cerebral hypoperfusion in young healthy humans, this technique protects frontal lobe cerebral tissue oxygenation (assessed via near infrared spectroscopy, NIRS), while cerebral blood flow is not affected (indexed by ultrasound-derived measurements). However, these techniques are spatially limited to examining tissue oxygen in specific regions of the brain, or cerebral blood velocity or flow in specific blood vessels perfusing the brain. Furthermore, we have not examined responses to Pulsatile Perfusion Therapy in older individuals, who are known to have lower resting cerebral blood flow and impaired vascular function. In this REAP Bridge Grant, we will: 1) demonstrate that our method of Pulsatile Perfusion Therapy can be implemented within the MRI environment, and; 2) recruit and test cohorts of young (18-40 y) and older (≥ 60 y) healthy adults to systematically examine how Pulsatile Perfusion Therapy changes cerebral fluid dynamics (i.e., arterial and venous blood flow, and cerebrospinal fluid (CSF) flow), and global and regional tissue oxygenation during acute cerebral hypoperfusion. This work is an essential step for future investigations of Pulsatile Perfusion Therapy in clinical conditions of acute (e.g., hemorrhage, stroke, cardiac arrest) and chronic (e.g., sepsis, Alzheimer’s disease, vascular dementia) cerebral hypoperfusion. The data collected from this study will be used to support a NIH R01 resubmission, planned for 2025.
Malinee Neelamegam UNT Health Science Center HSC Heads Up October 2021
Malinee Neelamegam, PhD
Recipient of the New Investigator Award
“Exploring the Burden of Cognitive Impairment in Older Asian Indians ”
Bio: Dr. Neelamegam is an Assistant Professor of Epidemiology at the Department of Population and Community Health at the School of Public Health, UNTHSC. She received a Bachelor’s degree in Biomedical Sciences from the National University of Malaysia. At the University of South Florida as a Fulbright Scholar, she completed the MPH degree in Epidemiology and Global Health Practice and the PhD degree in Epidemiology. Prior to joining the UNTHSC faculty, she completed a two-year postdoctoral fellowship at the Yale School of Public Health as a Fogarty Global Health Equity Scholar, where focused on understanding aging in people living with HIV in Malaysia. Dr. Neelamegam’s research is focused on understanding successful aging in populations that face health disparities and strengthening aging research through implementation science. Her current areas of research include understanding aging in people living with HIV, and the impact of social determinants of health and adverse life experiences on aging in immigrant populations.
Current Project: The research goal for Dr. Neelamegam’s study, “Exploring the Burden of Cognitive Impairment in Older Asian Indians,” aims to investigate the prevalence of neurocognitive impairment and identify associated psychosocial risk and protective factors, including social isolation and acculturation stress, in older Asian Indian immigrants in the U.S. This pilot study will provide foundational data necessary for designing targeted interventions that address the unique aging trajectories of this population, ultimately contributing to culturally tailored strategies to mitigate cognitive decline and support healthy aging within minority communities.
Gregory Dick, Ph.D. Recipient of the New Investigator Award
“Role of potassium as a coronary metabolic vasodilator ”
Bio: Dr. Dick received a Bachelor of Science degree in Physiology from Oklahoma State University and a Ph.D. in Physiology from the University of Missouri. He performed postdoctoral research at the University of Nevada. Dr. Dick studies mechanisms of coronary vasodilation, including dilation in response to metabolic, ischemic, and paracrine stimuli. These studies encompass mechanisms of coronary vascular regulation in health and disease, including obesity, metabolic syndrome, and heart failure.
Current Project: “Role of potassium as a coronary metabolic vasodilator” The aims are: 1) To quantify the magnitude of K+-induced coronary vasodilation. Exogenous K+ will be added to coronary arterial blood while cardiac rate and work are at baseline levels. We will determine the correlation between the concentration of K+ in coronary venous blood and the degree of vasodilation. 2) To quantify coronary venous K+ during physiologically-relevant increases in cardiac work (i.e., dobutamine infusion) and use a model to estimate the interstitial concentration of K+ as myocardial oxygen consumption and coronary flow increase. The goal is to apply for an NIH R01 to perform a rigorous study testing the hypothesis that K+ is a feed-forward vasodilator by applying 4 criteria (akin to Koch’s postulates) for defining a local metabolic mechanism of flow control.
Uyen-Sa D. T. Nguyen, DSc, MPH
Recipient of the New Investigator Grant Program
“The Viet-American National Databank Pilot Study”
Bio: Dr. Nguyen received a Bachelor of Science degree in Biology from the University of Michigan, a Master of Public Health in Epidemiology and Biostatistics, and a Doctor of Science degree in Epidemiology from the Boston University College of Public Health. She has experience conducting or collaborating on epidemiologic studies on topics ranging from perinatal to geriatric epidemiology, both within the U.S. and at international institutions. Her areas of interest include aging research, and examining pain, function and quality of life in people with rheumatic diseases, diabetes, and other chronic conditions. She also seeks to understand factors associated with health disparities in marginalized, underserved and underrepresented populations, particularly in Vietnamese Americans.
Current Project: “The Viet-American National Databank Pilot Study” The aims are: to translate, validate, and pre-test linguistically and culturally appropriate questionnaires; and to pilot-test these questionnaires in a sample of Vietnamese Americans with rheumatic conditions living in Texas and California, two states with the highest concentrations of Vietnamese speakers outside of Vietnam. With this Pilot data, we hope to apply for and receive R01-type funds to enroll a large cohort of Vietnamese Americans with rheumatic diseases to examine racial/ethnic differences in health outcomes and healthcare utilization.
Ritu Shetty , PhD
Recipient of the New Investigator Grant Program
“Methionine Synthase: A target for novel small molecules to block methamphetamine-seeking behavior”
Bio: Dr. Shetty is a behavioral pharmacologist and a pharmacist by training. She has dedicated the last 15 years of her career to advancing the understanding of substance use disorders through preclinical research. Her research interests span into a wide range of crucial areas in the field of substance use disorders. Dr. Shetty collaborates closely with a team of researchers at UNTHSC on an Addiction Treatment Discovery Program, which receives funding from the National Institute on Drug Abuse (NIDA). The goal of this program is to identify potential treatments for drug dependence. Moreover, within this team, she also collaborates with the Drug Enforcement Administration (DEA) to assess the abuse potential of emerging synthetic drugs. Understanding how these novel substances compare to well-known drugs helps in predicting their misuse potential and guiding regulatory decisions.
Current Project: As an independent researcher, one of Dr. Shetty’s goals is to identify genetic markers associated with drug-liking versus drug-dislike behavior. Genetic insights into such phenotypes could revolutionize our understanding of mechanisms of substance use susceptibility. Thus, paving the way for personalized therapies aimed at preventing dependence.
Liang-Jun Yan, PhD
Recipient of Bridge Grant Program
“Generation of renal specific NAD kinase knockout and transgenic mouse models ”
Bio: Dr. Yan’s lab does research on kidney disease, in particular, ischemia- and drug-induced acute kidney injury and diabetic kidney disease. Our goal is to understand how mitochondrial oxidative stress and redox signaling contribute to these kidney diseases, and to identify novel targets for developing potential therapeutics. Students who would like to work in the lab will gain knowledge on mitochondrial dysfunction in kidney disease and metabolic disorders, and will develop skill in biochemical techniques for mitochondrial functional analysis.
Current Project: The goal of our research is to elucidate the mitochondrial mechanisms and pathophysiology underlying kidney disease induced by pharmacological agents and environmental toxins, with an aim to explore novel therapeutic strategies by identifying new targets that can be applied to prevent the development and progression of kidney injury. The target protein in this bridge grant is mitochondrial NAD kinase (also known as NADK2). As the significance of this protein in kidney injury induced by heavy metals or ischemic reperfusion is not known, we propose to explore the magnitude of kidney injuries in the absence or overexpression of NADK2. This exploration would require the generation of NADK2 knockout and NADK2 transgenic mouse models, which is as proposed in the bridge grant.
Social media