Horizons is directed by Isabel C. Arnold RN, BSN, CCRC a bilingual, certified, and
highly experienced clinical research coordinator who entered the clinical research
field in 1993.
Isabel is from Chile, where she graduated from "La Universidad Catolica de Chile" in
1990 as a Registered Nurse. For the following six years she worked and gained
experience in the areas of pediatrics, OBGyn, internal medicine, and cardiology. In
1993 she also began to participate in clinical research trials, mainly in the areas of
women's health and internal medicine.
In 1996 she was hired by Merck, Sharp & Dohme as a clinical research coordinator.
during the nearly five years that she worked with Merck she attended numerous
training courses sponsored by the company. She also opened and ran several
study sites with trials in the areas of cardiology, neurology, bronco-pulmonary and
In October of 2000 she moved to Denver, Colorado with her fiancé and soon to be husband, Bill Arnold.
After learning English she continued her career in clinical research at the University of Colorado Cancer Center in
phase I studies. There she had the opportunity to not only run clinical trials but also to re-organize and manage
the phase I laboratory. While working at UCHSC she prepared and passed the examination to obtain her RN
qualification in Colorado.
After three and a half years working at UCHSC and prior to becoming the director of Horizons she moved to a
private site as a clinical research coordinator where she ran studies in phases II to IV. She eventually became the
site manager and under her management the site was recognized by more than 20 pharmaceutical companies,
Clinical Research and Site Management Organizations in the United States and Europe for the superb quality and
professionalism of its work. During this period she also obtained her certification as a Clinical Research
Coordinator through the Association of Clinical Research Professionals.
Outside of work Isabel and Bill enjoy international travel, landscaping and remodeling their home, hiking in the
Rockies, and of course a fine glass of Chilean wine in the evening.
Bill Arnold has been the Business Manager for Horizons since the Center’s inception in early 2007. Among his
responsibilities are: the company finances; data management; website design, creation, and maintenance;
volunteer recruitment; marketing, human resources, and management of the Center’s facilities and information
technology. In addition to his duties at Horizons Bill was also a member of the Institutional Review Board (IRB) at
National Jewish Health for two years.
Bill graduated in 1995 from Southern New Hampshire University at the top of his class with a Bachelor of Arts
degree in International Business. In 1996 he became the Assistant Director of an international language center in
Santiago, Chile and was in charge of the Scheduling Department, Study Abroad Department, marketing of the
Study Abroad Program, and management of over 80 teachers.
In the fall of 2000 Bill accepted the position of Director of Admissions at the language center’s headquarters in
Denver, Colorado and moved back to the United States with his fiancée, Isabel. During the following four and a
half years Bill was responsible for the sales and admissions for the company’s schools in Denver, Colorado;
Santiago, Chile; Buenos Aires, Argentina; Rio de Janeiro, Brazil and affiliated schools throughout Latin America
and Spain. He also participated significantly in the international marketing of the language programs, website
design, and creation of brochures and other marketing materials.
In the fall of 2004 Bill started his own real estate investment company and within a few months began devoting his
full attention to his new business. After three successful years in real estate investing Bill now devotes his time and
energies to his duties at Horizons.
Outside of work Bill and Isabel enjoy international travel, landscaping and remodeling their home, hiking in the
Rockies, and of course a fine glass of Chilean wine in the evening.
Horizons is proud to have a group of highly qualified, experienced and enthusiastic physicians who not only have
decades of experience in private practice but now have up to ten years of experience as Principal Investigators
having conducted many and varied studies.
Dr. Cara Dawson
Dr. Dawson completed medical school at the University of Colorado Health Sciences Center with multiple honors,
She is a board certified Internist who completed her internship and residency in internal medicine at the University
of Colorado Health Sciences Center in June 2000.
She served as a Chief Medical Resident at the University of Colorado Health Science Center. Dr. Dawson has
built a successful, thriving private practice in Internal Medicine at Rose Medical Center. She remains an active
clinical faculty member at UCHSC teaching both residents and medical students. She also served on the quality
assurance committee for Rose Medical Center. She has been a member physician of a busy Internal Medicine
practice since 2000.
In 2007 Dr. Dawson decided to expand her career by joining Horizons Clinical Research Center as a Principal
Investigator and shortly thereafter received the training and certification in ICH/GCP provided by the center. She
has since been, or is presently, the Principal Investigator for many clinical studies including those for Chronic Low
Back Pain, Acute Low Back Pain, Hypercholesterolemia, Overactive Bladder in Women, Type 2 Diabetes,
Hypertension with Type 2 Diabetes, Hypertension in Minorities, Overactive Bladder in Men and Women, Gout,
Hypertriglyceridemia, Chronic Idiopathic Constipation, Irritable Bowel Syndrome / C & D, and Osteoarthritis of the
Knee. She has also been the Sub-Investigator for a number of Dr. Cooper's studies.
She enjoys running, tennis, cooking and being with her three children and husband.
Her enthusiasm, energy, professionalism, ethical values and agreeable personality make her an invaluable
To learn about the current enrolling studies in internal medicine click here.
Center, and clinical professor of ObGyn at the University of Colorado Health Science Center since 1975.
Dr. Cooper did an internship in internal medicine at Kings County Hospital in New York from 1969 to 1970 followed
by two years of military service. As a medical officer he was stationed at the Colorado River Indian Tribes
Reservation in Parker, Arizona where he was responsible for obstetrics and gynecology, pediatrics, trauma, and
emergency medical services and inpatient/outpatient general medicine.
He did his residency in obstetrics and gynecology at the University of Colorado Health Science Center between
1972 and 1975, during which time he was chief resident from July 1, 1974 to June 30, 1975.
Dr. Cooper has sat on many professional committees and boards of director, and has held numerous staff
leadership positions during his career.
He joined Horizons Clinical Research Center, LLC in early 2008 and shortly thereafter received training and
certification in ICH/GCP guidelines. He has since been the Principal Investigator for many clinical trials including:
Fibrocystic Breast Disease, Post-Menopausal Vulvovaginal Atrophy, Post-Menopausal Osteoporosis,
Endometriosis, Hypoactive Sexual Desire Disorder, Oral Contraceptives, Ring Contraceptives, and Vasomotor
Symptoms. He has also been the Sub-Investigator for many of Dr. Dawson's studies.
During his free time Dr. Cooper enjoys skiing, biking, travel, birding and photography.
Dr. Cooper’s extensive experience, professionalism, integrity, kindness, and enthusiasm for his profession and
clinical research make him an excellent physician and Principal Investigator.
Nancy Krywonis, MD is originally from Canada and it is at the University of Manitoba in Canada where she
obtained her Medical Doctorate in 1984. She also did her Internship in Mixed Medicine (1984-1985) and her
residency in Internal Medicine (1985-1986) at the same University. She did her Residency in Dermatology later at
the University of Minnesota (1986-1989). She has been a board certified Dermatologist in both Canada and the
United States since 1989.
From 1989 to 1992 she was an attending physician and assistant professor at the Veterans Affairs Medical Center
at the University of Minnesota. Then for the next 13 years she was in private practice at the Metropolitan
Dermatology and Cutaneous Surgery, PA in Wayzata, Minnesota.
After moving to Denver with her family she worked with two local Dermatology practices, Health Mark and
Canterbury Wellness until she started her own practice, “SkinCare Colorado”, in 2010. Her practice is conveniently
located in the Rose Medical Center just two blocks from Horizons.
Dr. Krywonis has been a member of the American Academy of Dermatology since 1989 and a member of the
Colorado Dermatology Society since 2005. She began working with Horizons as a Principal Investigator in 2012
and has since conducted many studies for conditions such as: Plaque Psoriasis, Atopic Dermatitis, Actinic
Keratosis, Acne Vulgaris, Nodulocystic Acne, and Cutaneous Common Warts.
Dr. Krywonis’ high energy and enthusiasm for research and her studies communicates itself to everyone from our
patients to all the staff here at Horizons. Her expertise and many years of experience in Dermatology also serve
her well as a Principal Investigator. It is a true pleasure having her on our team.
To learn about the current enrolling dermatological studies click here.
In addition to Horizons’ management team and Principal Investigators we also have a support staff of Clinical
Research Assistants (CRAs) and Clinical Research Coordinators (CRCs). The CRAs are responsible for multiple
functions including: EDC, processing and shipping study samples, recruiting study patients, venipuncture and
patient vitals when necessary, as well as myriad other tasks. The CRCs are primarily responsible for conducting
studies per protocol and accepted ICH/GCP guidelines in coordination with the Principal and Sub-Investigators.