Our Team
Carlo M. Taboada, MD

Dr. Taboada is the Chief Executive Officer at Clinical Associates in Research Therapeutics of America, CARTA. 


His involvement in clinical trials includes both academic and pharmaceutical research.


He has successfully developed and evolved over 17 clinical research centers throughout the country. 


Dr. Taboada understands the trials and tribulations for medical practices; through clinical research, he is able to partner up with specialists and bring clinical trials to them and their patients. Through this symbiotic relationship, he is able to help patients by providing their physicians with the appropriate trials to help them improve their quality of life by controlling their disease states. Just one more tool in the armamentarium to help clinicians and patients achieve their goals for a better life through better disease control. 

Jaime L. Mayoral, MD

Dr. Mayoral is the President of San Antonio Colon and Rectal Clinic where he has been in private practice since 1995. 


Dr. Jaime L. Mayoral and his group specialize in diseases of the colon and rectum and abdominal surgery primarily through laparoscopic techniques. They are also well versed in robotics surgery (DaVinci Surgery) as well as Sacral Neuromodulation (Interstim). 


Dr. Mayoral is the Program Director of the Colorectal Surgery Fellowship at Methodist Hospital. He also is the Director of the US Army Trauma Simulation Laboratory, at the Mayo Clinic in Rochester, Minnesota. 


He most recently retired as a Colonel from the United States Army after faithfully serving our great nation for 28 years. 



Kathy Untermeyer, CCRC, MA 

Sadie Perez, CRA

We have been beyond blessed to count on Kathy as our lead research coordinator for CARTA. Her devotion to research for the last 12 years as a Certified Clinical Research Coordinator speak volumes of her love for this profession!!

Sadie joins the research team as a clinical research associate. She is currently in her senior year at the University of Texas at San Antonio pursuing a Biology degree. She has a strong desire to help people & is eager to learn the world of clinical research and how it contributes to helping people coping with chronic diseases. We are very blessed to count on her passion to serve others - one of CARTA's mantras!!

Linda Ingeborg Esquivel, MD

Dr. Esquivel was born in Laredo, Texas. She attended St. Mary's University in San Antonio, where she graduated Summa Cum Laude. She received her medical degree from the University of Texas School of Medicine at San Antonio and went on to complete her residency in Family Medicine at CHRISTUS Santa Rosa, where she graduated with honors. 

Dr. Esquivel has been awarded "Most Compassionate Doctor" from 2009 to 2014. She is also a 5 year honoree of the "Patients Choice Award" as well as voted as one of "San Antonio's Top 10 doctors" in 2014.

Regina K. Lee, MD

Dr. Lee was born in Bonham, TX. She attended Texas Tech University for her undergraduate studies and obtained her medical degree from the University of Texas School of Medicine at San Antonio. She completed her residency in Family Medicine at Christus Santa Rosa. 

*Dr. Taboada obtained his medical degree from the University of Monterrey in Monterrey, Mexico. He is a not licensed to practice medicine in the State of Texas

Our Associates


San Antonio Colon and Rectal Clinic - Jaime Mayoral, M.D. & Maria L. Martinez, M.D.

Family Health of South Texas - Linda Esquivel, M.D. & Regina Lee, M.D.

South Texas Smiles - Dr. Anna Maldonado, Dr. Adam Furman