Our Providers

Dr. Hays grew up in Iowa and then relocated to Arkansas with his family while he was in high school. He later attended the University of Arkansas for his undergraduate studies and received a Bachelor of Science degree in Education with an emphasis in Athletic Training. He is currently Board Certified in Athletic Training and also licensed in the State of Texas as an Athletic Trainer. He attended California University of Pennsylvania and received a Master’s Degree in Exercise Science with an emphasis in Performance Enhancement and is certified as a Performance Enhancement Specialist through the National Academy of Sports Medicine.

Dr. Hays attended Medical School at Ross University School of Medicine and completed his residency training in Family Medicine at the University of Arkansas for Medical Sciences Regional Programs in Fayetteville, Arkansas. He is an avid HOGS fan, and his interests include HIV Medicine, Sports Medicine, along with Wellness and Primary Care Medicine.

Dr. Nathan Luke is a family medicine physician who provides comprehensive primary care. Born and raised in Maryland, he completed his undergraduate degree at the University of Maryland, College Park. He was awarded his medical degree from Oakland University William Beaumont School of Medicine. Then, he completed his Family Medicine Residency at LewisGale Medical Center in Roanoke, Virginia, where he was selected to be Chief Resident during his final year of training. Dr. Luke enjoys seeing patients for both acute and chronic conditions. He is passionate about connecting with patients and providing patient-centered care. He also enjoys traveling, spending time with family, cooking, and trying new foods.

Dr. Graneto works to keep Dallas healthy–one patient at a time–by creating individual health plans customized to each patient’s unique needs. He grew up in Cleveland, Ohio, and graduated from The Ohio State University College of Medicine before moving to Dallas. He completed his residency in Family Medicine at the University of Texas Southwestern and is certified by the American Board of Family Medicine. His areas of interest include preventive medicine, general primary care, HIV treatment, health information technology and optimizing management of chronic medical conditions.

Since his freshman year of high school, Dan Nguyen dreamed of becoming a physician who cares for, understands, and serves as a role model for the LGBTQ+ community. As a resident intern, he volunteered at a local STI clinic in Austin, Texas, on his days off. He continued to volunteer there and eventually worked full-time. It was in this setting that he cultivated a sex-positive attitude toward health and wellness, as well as an understanding of providing care to people living with HIV/AIDS.

In addition, he has experience with curative treatments for Hepatitis and Buprenorphine for Medication-Assisted Treatment (MAT).

A Dallas native, Dan moved back from Austin to join UPG, continue his career in HIV medicine, sign with the Turtle Creek Chorale, and spend more time with his nieces and nephews—an easy decision.

Fun facts: His bachelor’s degree is in computer science, making him a huge technology enthusiast. He enjoys reading tech blogs, MotorTrend car reviews, playing pickleball, and jogging. In 2021, he ran his first half marathon—and finished in a cute pair of pink stilettos!

Dr. Sinclair is a Graduate of Case Western Reserve University School of Medicine. He has practiced Infectious Disease Medicine and HIV Primary Care since finishing his Fellowship in Infectious Diseases at Case Western in July of 2000. He was a faculty member at The University of Texas Southwestern Medical Center at Dallas between 2000 and 2010 and achieved the rank of Associate Professor. In 2006, he took a year-long sabbatical to work at Merck and Co., Inc., where he was part of the team that prepared the New Drug Application which led to FDA approval of Isentress in 2007. He has served as the Director of Medical Education for the Texas Oklahoma AIDS Education and Training Center. He has been involved in the President’s Emergency Plan for AIDS Relief and participated in training events in Oshakati, Namibia, and in the Limpopo Province of South Africa. He currently practices HIV Medicine at Prism Health NTX in the southern sector of Dallas, Texas, and he holds privileges in Internal Medicine and Infectious Diseases at Baylor University Medical Center in Dallas. His clinical focus has always been expanding access to new treatment modalities in underserved communities, particularly for people with stigmatizing illnesses such as HIV, Hepatitis C, Sexually Transmitted Infections, and Tuberculosis.

Rasha Ghurani is a doctor at Prism Health North Texas.

Dr. Saleh Musleh is a physician at Worth Street Health Center, part of Prism Health North Texas. He earned his Doctorate degree from Des Moines University and completed his residency training at the University of Chicago. Prior to joining Prism Health North Texas, Dr. Musleh practiced hospital medicine at Baylor for more than eight years, where he developed extensive clinical expertise in acute care.

Now in primary care, Dr. Musleh is passionate about building long-term relationships with patients and witnessing the continuity and progress of their health improvements over time. He is especially committed to serving the LGBTQ+ community through Prism Health North Texas, where he values the opportunity to provide inclusive, affirming, and comprehensive care.

Dr. Musleh lives in Dallas with his husband and their three dogs—Habibi, Enzo, and Leo. Outside of his work, he enjoys biking, traveling, and spending time with his dogs.

Dr. Oregon McDiarmid is joining the Prism Health North Texas team at the South Dallas Clinic. Originally from England, he has spent years traveling around the United States and abroad while pursuing his education in medicine. He completed his undergraduate degree in Biomedical Sciences from Northern Arizona University and his Doctorate in Medicine from Trinity School of Medicine. He completed his residency training in Family Medicine from the University of Illinois Chicago. He practices full scope family medicine seeing patients of all ages, with strong passions in preventative medicine, chronic disease management, sexual health, HIV treatment and PrEP, and individualized health goals. Outside of work Dr. McDiarmid enjoys staying active playing on several sports teams including volleyball, dodgeball, kickball, and rugby.

Dr. Rachel Rivera graduated from UT Health Science Center San Antonio School of Medicine in 2007. She completed her Residency at UT Southwestern in Dallas 2007-2010 and participated in the Infectious Diseases Fellowship at UT Health Science Center San Antonio 2010-2012. Dr. Rivera is board certified in Internal Medicine and Infectious Diseases.

Richard Ornberg is passionate about providing inclusive, patient-centered, holistic primary care to his patients. He completed nursing school at the University of Texas at Arlington with a Bachelor of Science in Nursing. He worked as a nurse in the emergency department at multiple Level I trauma centers. Rick then earned his Doctorate in Nursing Practice from Texas Wesleyan University. His doctoral project studied alternative, mindfulness-based, and holistic interventions to manage chronic pain. After graduation, he worked as a primary care provider in an addiction and recovery facility. He is a board-certified Family Nurse Practitioner through the American Association of Nurse Practitioners as well as credentialed by the American Academy of HIV Medicine as an HIV Specialist ^TM.

Rick grew up in Chicago before relocating to Dallas where he has lived for over 30 years. He enjoys traveling and spending time with his family and three pups in his free time.

Jennifer Klein is a Family Nurse Practitioner in Dallas who has provided primary and specialized care for people living with HIV since 2005. Her professional experience prior to working in HIV includes public education, community health, and specifically health promotion. Jennifer was fortunate enough to stumble into her career with Prism Health North Texas while fulfilling her commitment to working in an underserved clinic through National Health Service Corps. She completed her Master of Science in Nursing at Johns Hopkins University School of Nursing in 2004. Jennifer maintains credentialing as an AAHIVM Specialist, acts as a sub-investigator on multiple clinical trials, and currently sees patients full-time.

Natalie Smith-Low is a licensed psychotherapist, clinical social worker supervisor, registered yoga teacher, and Behavioral Health Counselor at Uptown Physicians Group. She holds a bachelor’s degree in social work from the University of Texas at Austin and a master’s degree in social work from the University of Texas at Arlington. Natalie began her clinical career working with children, adolescents, and families in a hospital setting and later developed an adolescent psychiatric intensive outpatient program for a major Texas hospital system.

In addition to her work with younger populations, Natalie is passionate about supporting adults through individual therapy, relationship therapy (poly-friendly), and group therapy. She specializes in addressing the unique challenges of the LGBTQIA+ community and incorporates therapeutic yoga into sessions upon request. Her approach to therapy is gentle, patient, and affirming, aiming to create a space that is validating, approachable, and collaborative. Clients often describe her as easy to talk to, open-minded, and goal-oriented, with “excellent comedic timing” when appropriate.

Natalie has received formal training in Dialectical Behavior Therapy (DBT), Eye Movement Desensitization and Reprocessing (EMDR), play therapy, and Acceptance and Commitment Therapy (ACT). She also holds advanced training in Cognitive Behavioral Therapy (CBT) from the Beck Institute and is Gottman Level I & II trained, Gender Asset trained, and a Certified Sex Therapy Informed Professional (CSTIP). Additionally, Natalie completed her 200-hour yoga teacher training at Dallas Yoga Center in 2022 and furthered her yoga education in Bali, Indonesia.

Outside of work, Natalie enjoys spending time with her wife and their three fur babies—Lucy, Bentley, and Grace. They live in the Oak Lawn area and enjoy traveling, exploring new restaurants, participating in community events, and practicing yoga.

Dr. Charmeka Lipscomb, APRN, FNP-C, PMHNP-BC currently works as a mental health provider for Prism Health North Texas. She obtained her BSN degree from the University of Texas at Arlington. After a few years of floor nursing, she thought she wanted to take on management so she obtained a dual master’s in business administration and healthcare administration from Texas Women’s University. While working as an associate unit manager for Parkland’s HIV outpatient services, Charmeka found her first true passion and it wasn’t management; it was HIV. This passion prompted her to return to Texas Women’s University to obtain a Master’s of Science degree to become a Family Nurse Practitioner. Her first job upon completing nurse practitioner school was with Metrocare Services. It was there that Charmeka discovered her second love, mental health, which prompted her to get her post-masters certification in mental health from the University of Texas-Rio Grande Valley. She received her doctorate from Chatham University. Prior to PHNTX, Charmeka was the lead HIV provider for Parkland’s HIV jail services for over 5 years. HIV and Mental Health are passions of Charmeka’s because they are two of the most stigmatized disease processes in the black community. Until they’re openly discussed, the numbers will continue to grow and people will continue to suffer in silence. So let’s talk about it!

Kevin R Johnson is a certified Physician Assistant at Prism Health North Texas, where he is committed to delivering compassionate, comprehensive care to a diverse community.

Originally from Missouri, Kevin completed his undergraduate studies at the University of Illinois and went on to earn his Master of Science in Physician Assistant Studies from Missouri State University. He is board certified by the National Commission on Certification of Physician Assistants (NCCPA).

Kevin brings clinical expertise in psychiatry, internal medicine, HIV care, and men’s health. He is passionate about providing affirming, patient-centered care that supports both physical and mental well-being.

Outside of the clinic, Kevin is an avid fan of college sports—especially cheering for Illinois, Missouri State, and SMU. He was also deeply involved in the marching arts during his younger years and remains a strong supporter of the activity.

Brittney Tucker is a Licensed Professional Counselor Supervisor at PHNTX – Uptown Physicians Group. She earned her bachelor’s degree in psychology from the University of Southern California and her master’s degree in applied clinical psychology from Pennsylvania State University.

Brittney began her career at a medication-assisted treatment (MAT) facility for substance use in Chicago’s most vulnerable neighborhood, providing counseling to clients with dual diagnoses. Over the past nine years, this experience has strengthened her commitment to delivering accessible mental health care to communities with limited access to resources or facing barriers to care.

She specializes in treating depression, anxiety, trauma, grief, and issues related to self-worth. Brittney has formal training in Acceptance and Commitment Therapy (ACT) and Dialectical Behavior Therapy (DBT) and is also skilled in Cognitive Behavioral Therapy (CBT), Eye Movement Desensitization and Reprocessing (EMDR), and other evidence-based approaches. Brittney ’s therapy approach blends self-compassion, acceptance, nervous system regulation, and connecting with different “parts” of the self.

Known for her calm and warm demeanor, Brittney brings an affirming and compassionate approach to therapy. She strives to create a safe, nonjudgmental space where clients feel seen, heard, and supported on their journey toward growth and healing.

Brittney resides in Dallas and enjoys traveling, scrapbooking, listening to audiobooks, and spending quality time with loved ones outdoors – bonus if it’s a rooftop.

Erika Martinez is a Licensed Professional Counselor (LPC) and National Certified Counselor (NCC) with a bachelor’s degree in psychology from the University of Connecticut and a master’s degree in counseling from Texas A&M University–Commerce (2020).

Since joining the agency in 2015 as a case manager, Erika has been dedicated to supporting clients through compassionate and evidence-based care. She has formal training in Acceptance and Commitment Therapy (ACT), Eye Movement Desensitization and Reprocessing (EMDR), Cognitive Behavioral Therapy (CBT), Play Therapy, and Sandtray Therapy.

Fluent in both English and Spanish, Erika provides accessible, culturally responsive services to diverse communities. Her professional interests center on helping individuals navigate life’s challenges, heal from trauma, and build meaningful lives aligned with their values.

Outside of counseling, she enjoys spending time with her family, reading, and exploring the outdoors through hiking.

Dr. Luis E. Sanchez-Febres is the Clinical Dental Director at PrismHealth North Texas, where he is dedicated to providing top-tier dental care and fostering a patient-first philosophy. Known for his warm and approachable demeanor, Dr. Sanchez-Febres ensures compliance with OSHA and HIPAA standards while mentoring other providers to promote leadership and professional growth.

Collaborating closely with the Director and VP of Clinical Affairs, Dr. Sanchez-Febres delivers continuing education courses and actively participates in clinical subcommittees to enhance practice standards. He has successfully led initiatives such as quadrant dentistry and using Silver Diamine Fluoride (SDF), Curodont, and sealants in preventive care, significantly improving patient outcomes.

Dr. Sanchez-Febres holds a Doctor of Dental Medicine (DMD) from the University of Puerto Rico School of Dentistry, where he was honored with the Award in Memoriam of Dr. A. Raymond Baralt Jr. for his professionalism and leadership. He is board-certified in Texas and Puerto Rico and has completed a Pediatric Dentistry Practicum. His certifications include ClearCorrect, Lumineers, DEA license, CPR, NOS2, Brasseler Rotary Tool Endodontics, and FBI NCIC Dental Coding.

Recognized in Strathmore’s Who’s Who for leadership, Dr. Sanchez-Febres is an active member of the Dallas Study Club, Hispanic Dental Association, and American Dental Association. He is committed to ongoing education and promoting inclusion and diversity within the practice.

Outside of his professional life, Dr. Sanchez-Febres cherishes spending time with family and friends, traveling to new places, diving into a good book, enjoying music, experimenting with new recipes in the kitchen, and expressing his creativity through painting and plastic arts. These activities not only provide a well-rounded balance to his dedication to dentistry but also make him a relatable and familiar figure to his patients and colleagues.

With a steadfast dedication to excellence and a deep-rooted passion for patient care, Dr. Sanchez-Febres continues to lead and inspire the dental team at PrismHealth North Texas, instilling a sense of reassurance and confidence in his colleagues and patients.