Gemma Malagón 2019, senior Biomedical engineering Tecnológico de Monterrey, Mexico
My Research Project
As a Fellow from the American Physiological Society (APS), Hearst Undergraduate Summer Research Fellowship, I was grateful to have had an opportunity to work under Dr. Arellano at the University of Houston at the Center for Neuromotor and Biomechanics Research.
My research this summer focused on the biomechanics of arm swing across different walking speeds and its effect on the metabolic cost. Our main objective was to better understand the passive and active contributions by examining the electromyographic (EMG) activity of the muscles involved in arm swing, with a special focus on understanding how changes in EMG amplitude in the upper limb varied across walking speed.
The data acquisition consisted of:
Measurements of oxygen consumption and carbon dioxide production using indirect calorimetry, which is a process that measured the amount of heat that was released or absorbed during a chemical reaction;
XYZ coordinates of joint positions, which has the objective to understand the kinematics of the body;
Ground reaction forces; and
Muscle activity of arm muscles of interest.
These measurements allowed us to compute and compare metabolic power, joint angles and mechanics and average muscle activity patterns when walking with and without arm swing.
Realities of Research
The research that I conducted was exciting and it was a wonderful experience working in the lab. In the beginning, I spent most of my time reading articles and doing research on my assigned project. I had an engineering background prior to my summer research, so one of the aims of my research project was to develop an efficient MATLAB code to process and analyze the EMG data collected on the studies.
I have learned to measure my progress due to the number of setbacks I had, which also helped me realize different paths which brought me closer to reaching my goal. I have learned more than I could ever hope and was fortunate to have had the opportunity to work—even for a little while—with some of the most talented and coolest people in the U.S.
Life as a Scientist
I made the decision to study biomedical engineering with a concentration in research driven by my desire to contribute to fundamental breakthroughs in medicine and become a better Mexican-researcher. This past summer, besides working on my own research, I’ve was involved in many lab projects, so I realized how amazing it is when you work with people who share the same passion as you. The truth is, having to work eight hours a day during the week, and some days even more, might be tiring! This was especially true when I would have to take the bus for two hours to get to the lab and two more hours to get back home. However, it was a unique experience that not everyone is willing to take advantage of. Participating in this program not only widened my research experience, but it has helped me on my path towards a master’s degree, which I plan to pursue after I graduate.
Reference:
Christopher J. Arellano, Rodger Kram. Journal of Experimental Biology 2014 217: 2456-2461; doi: 10.1242/jeb.100420
Gemma Malagón is a senior majoring in biomedical engineering at the University of Tecnológico de Monterrey in Mexico. She is a Hearst Undergraduate Summer Research Fellow working in Dr. Arellano’s lab at the University of Houston, Health and Human Performance Department. Gemma’s fellowship is funded by the American Physiological Society and Hearst Foundations. After graduation, Gemma plans to pursue a master’s degree in clinical and sports engineering.
Acknowledgements
I would like to express my deepest appreciation to Hearst Foundations and the American Physiological Society (APS) for my research fellowship, and to Dr. Christopher J. Arellano, which the completion of my internship would not have been possible without his support and mentorship.
Touré Jones Junior, human health major Emory University
My Research Project
Post-traumatic stress disorder (PTSD) is a debilitating mental illness that heavily impacts an individual’s physical, mental and emotional health. One overlooked, but very important, consequence of this illness is that individuals with PTSD have an increased risk of developing hypertension and cardiovascular disease1. Past research has revealed that those with PTSD have an exaggerated blood pressure and heart rate response and a blunted heart rate variability response to acute mental stress1. While these studies have improved our understanding of PTSD and the physiological effects it has, they don’t highlight a very important factor: the possibility that it affects men and women differently.
PTSD studies have typically been either all men, or a very few women included in a mostly male population. The research has produced results that primarily focus on male reactivity2, andhas neglected an entire demographic of PTSD victims that seem to have a different response. While men and women have a similar rate of experiencing traumatic events, women are twice as likely to be diagnosed with PTSD3. In addition, healthy premenopausal women have a lower risk of developing cardiovascular disease compared to men, although once diagnosed with PTSD, this risk increases three times, placing the women at higher risk3. Given these biological differences, the purpose of this study was to determine if there is also a sex difference in autonomic and cardiovascular responses to acute mental stress in individuals who have PTSD.
Our study consisted of 33 individuals— 15 women and 18 men—for a total of two visits. The first visit was a screening where we took the volunteers’ vital signs, gave them PTSD surveys to determine the severity of their condition and checked for exclusion criteria to ensure they could be in the study. The second visit was a micro visit, where we recorded experimental data. We measured the study subjects’ blood pressure, heart rate and muscle sympathetic nerve activity at baseline, then those same recordings during three minutes of mental stress. Beat-to- beat blood pressure was recorded using a continuous noninvasive arterial pressure (CNAP) monitor and heart rate was recorded via an electrocardiogram (EKG). Muscle sympathetic nerve activity (MSNA) was recorded via the microneurography procedure. Mental arithmetic served as our mental stressor: the participants subtracted a given number from a numbered index card continuously for three minutes while a “coach” was pressuring them to give an answer as quickly as possible.
At baseline, measurements for age, body mass index, clinician-administered PTSD scale (CAPS) and PSTD checklist–military version (PCLM) survey scores, blood pressure and heart rate variability were all comparable between the sexes. However, MSNA was significantly different. This was a very interesting find, as we were not anticipating this result. In healthy populations, men have a higher MSNA at rest than women. Based on this data, it seems that women with PTSD have a higher resting MSNA than men. In response to mental stress, systolic arterial pressure was higher in women than men, while diastolic arterial pressure was comparable between the two groups. In addition, heart rate seemed to be higher in women than men, but had not reached significance, although MSNA in response to mental stress was significantly higher in women compared to men. Even more interesting was the root mean square of the successive differences (RMSSD), the time domain measurement of parasympathetic nervous system activity, was comparable between both groups, but the high frequency domain for parasympathetic response showed women having a decreased response to mental stress than men.
In conclusion, resting MSNA was significantly higher in the women than the men. Systolic arterial pressure reactivity to mental arithmetic as higher in women with PTSD compared to men, while diastolic arterial pressure reactivity was comparable between the groups. Heart rate was comparable between women and men with PTSD. MSNA reactivity to mental stress was higher in women than men while heart failure response was blunted in women compared to men suggesting greater dysregulation of the autonomic nervous system in women with PTSD. RMSSD was comparable between men and women in response to mental stress.
In summary, women with PTSD in our study have an increased blood pressure and sympathetic response in addition to a blunted parasympathetic response to acute mental stress. These results provide insight into the mechanisms that are associated with a higher risk of cardiovascular disease in women with PTSD.
Realities of Research
Doing research in a lab was very different from my high school research experiences. For one, this was a clinical lab, so I was working with people every day, which was a rewarding experience. Also, my lab team was made up of very intelligent, cohesive and welcoming individuals, so during every study I was able to learn something new while having a good time. I also had to learn how to set up the lab for the studies we would be conducting, so I had to understand the procedure being performed and how to prepare for it. For example, one procedure we performed was microneurography— a qualified lab member inserted a tungsten electrode into the participants’ peroneal nerve to record sympathetic activity.
What surprised me about the experience was how often research doesn’t go as planned, especially when working with people. Some study participants wouldn’t come in to the lab as scheduled, or if they did, they didn’t want to go forward with certain procedures for a variety of reasons. Because of this, some patients didn’t have all of the data I anticipated collecting, but that was just a part of the research process.
As for our results, it was very rewarding to see my hard time and effort come to fruition. Some of the results I expected, but others I wasn’t expecting at all. Honestly, each result made the experience all the more exciting.
Life as a Scientist
Life this summer was challenging, but rewarding. I experience many exciting things that have provided me with good memories. The feeling that I felt once I formed graphs based on my data was great and was the best part of the experience; it was the result of my hard work and dedication to my project.
The worst part of the experience would have to be the hours I spent trying to understand certain topics by myself. While learning more about what I am doing interested me, there was some information I needed to know but took me a little while to grasp, which often annoyed me. However, once I did understand it, the passion I had for my project increased. Finally, my lab team was instrumental in me developing this project, especially my mentor. Her mentorship has taught me so much during the weeks I spent with her this summer and I am excited to learn even more.
References:
Edmondson D, von Kanel R. Post-traumatic stress disorder and cardiovascular disease. The Lancet Psychiatry 2017;4:320-9.
Park, J., Marvar, P. J., Liao, P., et al. (2017). Baroreflex dysfunction and augmented sympathetic nerve responses during mental stress in veterans with post-traumatic stress disorder. The Journal of Physiology, 595(14), 4893–4908. doi:10.1113/JP274269
Kubzansky LD, Koenen KC, Jones C, Eaton WW. A prospective study of posttraumatic stress disorder symptoms and coronary heart disease in women. Health psychology : Official Journal of the Division of Health Psychology, American Psychological Association 2009;28:125-30.
Touré
Jones is a junior majoring in human health at Emory University in Atlanta. He
is a 2019 Short-Term Research Education Program to Increase Diversity in
Health-Related Research (STRIDE) Fellow working in Dr. Jeanie Park’s lab also
at Emory University. Touré’s fellowship is funded by APS and a grant from the
National Heart, Lung, and Blood Institute (Grant #1: R25 HL115473-01). After
graduation, Touré plans on attending medical school to pursue his dreams of
being a physician.
Andrea Rico Junior, Health Sciences University of Texas at El Paso 2019 STRIDE Fellow
My Research Project
My research project was focused on measuring the vascular function and rate of blood flow in arteries of the upper and lower body extremities using flow- mediated dilation (FMD) and plethysmography. We investigated the differences in vascular function on endurance sports that are upper-body predominant, lower- body predominant and mixed combination. FMD is an advanced test that uses ultrasound to measure dilation changes in the diameter of arteries, such as those in the forearm. This is a method to assess the endothelial vascular function in humans. Plethysmography measures changes in volume of blood in different extremities like the upper- or lower-body extremities. These changes are measured with blood pressure cuffs attached to a machine known as the plethysmograph. This test can dictate the amount of blood flowing through the limb and time where peak blood flow happens. It is highly effective when it is used to find changes caused by blood flow. An endurance sport is any sport that has prolonged periods of physical stress. Swimming, for example, combines both cardio and light strength exercises mostly in the upper body, which trains the body to use oxygen more efficiently. Cycling combines both cardio and light strength exercises mostly in the lower body, increasing leg strength and endurance. American football involves a lot of resistance training in both upper and lower extremities. Comparing vascular function and structure in these three sports can help to determine specific changes with training modalities.
Realities of Research
This is my first time working in a lab and my first real research project, so it was pretty scary at first. However, as time passed, I started learning something new every day, including new techniques and skills. I slowly began to understand more about my project and its importance. It has been very exciting to be able to work on this project and being able to see the results.
Life as a Scientist
Working in a lab and being able to work with individuals who share the same passion has truly being an extraordinary experience. One of the greatest things that I personally have witnessed is seeing how all lab members collaborate with one another and help each other out. It has truly been an unforgettable experience to get to know everyone and share endless memories with one another. I love being part of a lab!
Andrea Rico is a junior at the University of Texas at El Paso majoring in health sciences. She is a 2019 Short-Term Research Education Program to Increase Diversity in Health-Related Research (STRIDE) Fellow working in Dr. Gurovich’s lab. Andrea’s fellowship is funded by the American Physiological Society and through a grant from the National Heart, Lung and Blood Institute (Grant #1 R25 HL115473-01). After graduation, Andrea hopes to pursue a PhD in occupational therapy and work at a local hospital or practice.
It is estimated by the American Heart Association that over 103 million American’s have hypertension, more commonly known as high blood pressure, which can have many adverse effects on the health of an individual. The kidneys are the filtering system of our bodies and work to remove waste and excess products every single day. When an individual has high blood pressure the vessels carrying blood within the kidney can become damaged and cause an inflammatory response that can lead to impaired kidney function and injury. My project looks at how we can block inflammation caused by high blood pressure and preserve kidney function. We do this by administering an antibody, a protein that can bind to specific targets to block their function, thereby reducing the inflammatory signals in rats that are hypertensive. Over a two-week period, we monitor blood pressure, food intake, water intake, body weight, and urinary output to provide an index of kidney function. At the end of the two-week period, we harvest the kidneys and utilize microscopy and video imaging to directly determine kidney blood vessel function. Using this approach, we can determine if the antibody treatment is protecting the kidney from hypertensive injury. This information allows us to understand how inflammatory signals influence organ function and develop new targets for medications for individuals with high blood pressure.
Realities of Research
My experience in my research lab this summer has been pretty different from my past research experiences. My research in the past has focused mainly on cell culture and use of a mouse model for my work. This summer I utilized a rat model and equipment I was not accustomed to working with, such as, machines that measure rat blood pressures. With my experience, there was a bit of learning curve and presenting my project progress weekly at lab meetings was very intimidating at the beginning. Shifting my focus to physiological research this summer also posed some challenges. When utilizing an animal model in physiological research there are many variables you have to account for. Most of these variables are out of your control so variation between experiments was common. Overall, this experience has helped shape who I am as a scientist and taught me how to successfully overcome obstacles. My project has produced promising data that suggests that inhibiting inflammation in kidneys that have been exposed to high blood pressure helps to preserve kidney function.
Life of a Scientist
A good day in lab usually consists of me coming into lab around 8AM and leaving around 5PM, but most days I find myself coming in early or leaving much later. I usually will take some work home with me but I always make sure I designate at least an hour every night to myself where I relax, catch up with friends, or catch up on my favorite shows. Although I tend to always be stressed about school work or a deadline, it’s made easier by the fact that I enjoy my work and what I study. I think the most rewarding part of any research undertaking is when you finish a project or find some promising data that help contribute to new scientific discoveries. Having an amazing lab team working alongside me also helps. I received some excellent guidance from many of the mentors in lab and especially from my PI who taught me the importance of oral and written scientific skills. I think it’s great having a close-knit group of individuals in lab that are always willing to help you succeed and help you troubleshoot an experiment when it does not work.
Brian Freeman is a senior at the University of California, Merced majoring in Biology with an emphasis in Microbiology and Immunology. He is a 2018 Short-Term Research Education Program to Increase Diversity in Health-Related Research (STRIDE) Fellow working with Dr. Edward Inscho at the University of Alabama at Birmingham. His fellowship is funded by the APS and a grant from the National Heart, Lung and Blood Institution (Grant #1 R25 HL115473-01). Upon graduating, Brian plans to enter a Biomedical PhD program and pursue a career in academia.
The Weddell Seal is able to hold its breath for 30 minutes at a time while diving in frigid Antarctic waters. To avoid running out of oxygen during this long dive, the seal collapses its lungs and restricts blood to only essential organs. In other mammals, the process of cutting off blood flow and the supply of oxygen to a tissue, only to reoxygenate those tissues at a later point (when the seal resurfaces) generates reactive oxygen species. The process causes oxidative stress, which damages the tissue. This summer I am studying some of the physiological adaptations that enable Weddell seals to avoid the detrimental effects of oxidative stress at a cellular level. At the moment I am focusing on catalase, an antioxidant enzyme that is good at breaking down hydrogen peroxide (a reactive oxygen species), to see if its activity is higher in seal tissues than in other mammals. The long-term goal of this research is to apply our understanding of how seals cope with oxidative stress to human organ transplants.
Realities of Research
This is my first time working in a lab so most everything has been entirely new to me, from the constant buzz of the -80 degree freezers to the techniques of growing cells to the precise technology. Besides learning many science skills, I’ve spent the last several weeks seeing how rare (and exciting!) it is for an experiment to work and yield significant results. Fingers crossed for the rest of my project!
Life of a Scientist
Besides working on my own research, I’ve been involved in numerous projects throughout the lab, so I’ve seen how research questions evolve and overlap and shift as researchers collaborate with one another. The aspect of collaboration within my lab has been one of the coolest things to witness this summer, especially since each researcher is doing distinct work. I’ve also loved getting to know my coworkers, and we’ve had cool conversations about new scientific discoveries and endless career options.
Throughout the summer, I’ve really appreciated being able to hold on to a big picture – of the real, live seals – even as I work at the microscopic, cellular level. I think this seal research is pretty darn cool.
Eliza Skoler is a senior Biology major and Neuroscience minor at Carleton College in Northfield, MN. She is a 2018 UGSRF fellow working in Dr. Allyson Hindle’s lab at Massachusetts General Hospital in Boston. She plans to pursue a career in public health.
