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Affiliated Faculty

The following faculty members are faculty who are active in teaching and may serve on dissertation and thesis committees.  Please click on the name of each member to learn more about them.  

Ronald E. Allen, PhD. *Retiring (Muscle Biology, Animal Sciences, Skeletal Muscle)

Program Affiliations:  Animal Sciences, Nutritional Sciences, Physiological Sciences

Website and Publications:

Contact Information:  (520) 626-1754,

Research Interests:  Muscle Biology, Animal Sciences, Skeletal Muscle

  • The focal point of research in this laboratory is the growth and repair of skeletal muscle in domestic animals and humans. The key player in both of these processes is the satellite cell. Satellite cells are muscle stem cells that are generally found in a quiescent, or dormant, state in close association with muscle fibers. Although sparsely distributed in postnatal muscle, they play an important role in regulating muscle growth by dividing and fusing with existing muscle fibers. The result is a net increase in the number of muscle fiber nuclei and hence, an increase in the growth potential of the fiber. In injured muscle, satellite cells are stimulated to divide and form new fibers that replace damaged muscle fibers. Consequently, the rate and efficiency of muscle growth and repair are dependent on the activity of satellite cells, and therefore, satellite cell function is relevant to muscle growth in domestic animals, to human muscle disease and injury and to problems associated with aging

  • Research goals in this laboratory have been to identify the hormones and growth factors responsible for satellite cells activation from the quiescent state, division and fiber formation. This problem is being approached by integrating experiments at the cellular, tissue, and whole animal level.

Zoe Cohen, PhD. (Platelets, Immunobiology)

Program Affiliations:   Physiology, Sarver Heart Center, Physiological Sciences

Website and Publications:  Sarver Heart Center Profile

Contact Information:  (520) 621-5485,

Research Interests:  Platelets, Immunobiology

Patricia B. Hoyer, PhD. (Ovarian Physiology/Toxicology, Menopause)

Program Affiliations:  Physiology, Pharmacology & Toxicology, Animal Sciences, Physiological Sciences

Website and Publications: 

Contact Information:  (520) 626-6688,

Research Interests:  Ovarian physiology/toxicology, menopause

  • Elucidating signaling pathways that regulate cell death by apoptosis
  • Establishing mechanisms of ovotoxicity caused by environmental chemicals
  • Developing models that alter the rate of atresia in ovarian follicles
  • Characterizing a chemically-induced follicle-depleted ovary-intact rodent for peri- and post- menopause

Douglas F. Larson, PhD. *Retired (Hypertension: Immune System, Left Ventricular Function)

Program Affiliations:  Department of Surgery, Biomedical Engineering, Medical Pharmacology, Bio5 Institute, Physiological Sciences

Website and Publications:  Department of Surgery Faculty Page

Contact Information:  (520) 626-6494,

Research Interests:  Hypertension: Immune System, Left Ventricular Function

  • The goal of my research is to define the relationship between the immune system and the left ventricular function. Recently, research activities have focused on the role of the immune system and its regulation of gene expression and enzyme function in cardiomyopathies. The models of cardiomyopathy being studied are secondary to HIV infection, infarction, rejection and aging. The hypothesis of these studies is that myocardial dysfunction secondary to an immune-cytokine event is mediated by increased iNOS and NO activity. In support of these studies, we have developed a system that can quantify the ventricular mechanics of the murine heart in vivo.

Lucinda L. Rankin, PhD. (Physiology/Teaching Workshop)


Program Affiliations:  Physiology, Bio5 Institute, Physiological Sciences

Website and Publications: 

Contact Information:  (520) 621-3104,

Research Interests:  Physiology/Teaching Workshop

Paul McDonagh, PhD. *Retired (Cardiovascular Complications of Diabetes and Air Pollution)

Program Affiliations:  Department of Surgery, Allan C. Hudson and Helen Lovaas Endowed Chair of Vascular Biology and Hemostasis, The Sarver Heart Center, Bio5 Institute, Physiological Sciences

Website and Publications: 

Contact Information:  (520) 623-2329,

Resaerch Interests:  Cardiovascular Complications of Diabetes and Air Pollution

  • Role of microcirculation in Ischemia-Reperfusion Injury

Claudia Stanescu, PhD. (Physiology/Director TA's)

Program Affiliations:  Physiology, Physiological Sciences

Website and Publications: 

Contact Information:  (520) 621-2795,

Research Interests:  Physiology/Director TA's

John A. Szivek, PhD. *Retired (Orthopaedic Surgery)

Program Affiliations:  Orthopaedic Surgery, Bio5 Institute, Physiological Sciences

Website and Publications:  Orthopaedic Faculty Homepage

Contact Information:  (520) 626-6094,

Research Interests:  Orthopaedic Surgery

  • John Szivek, PhD, used to employ a risky process to study new cartilage tissue.  His procedure for studying and growing new cartilage tissue involved removing a small piece of cartilage from the joint to be repaired, extracting cells in the lab, and growing the new tissue on a scaffold, which then was implanted into the joint. Due to the complexity of hyaline cartilage tissue, comprised of several layers of cells that do not divide or reproduce readily, the process was painstakingly slow and unpredictable, and new tissue often did not form at all.
  • Four years ago, however, Dr. Szivek’s team discovered that they could grow cartilage from differentiated (converted) adult stem cells extracted from fat tissue. These cells offer numerous advantages over cartilage cells. Not only can they be changed readily into a range of other cell types, but because of their long, spindly shape – unlike the rounded shapes of cartilage cells – researchers easily can judge whether they are aligning into the highly structured form they must be in to build hyaline cartilage. These cells are abundant and easier to obtain than cartilage cells and, since they are derived from a patient’s own fat tissue, they ensure there is no risk for rejection once they are introduced into the patient.
  • While earlier work in the Szivek lab concentrated on repairing damage to a relatively small area of a joint, the ability to grow cartilage more quickly and easily will make it possible to resurface a larger area of a damaged joint and, as such, will offer an alternative to total joint replacement.
  • Dr. Szivek’s earlier work involved implanting a small, rounded scaffold engineered by mimicking perfectly the normal structure of the injured bone in the joint. Before it is implanted, cartilage tissue growth on the surface is started in the lab. On the inside, these scaffolds are porous with a bone-like structure, allowing new bone growth to anchor them in place. Another novel aspect of Dr. Szivek’s scaffold system is that it is equipped with tiny sensors and a radio transmitter to monitor the patients’ activities and warn them if they risk injury to their new cartilage during exercise.
  • With his newest approach to growing cartilage, the scaffold covers one entire surface of the joint and makes it possible to grow cartilage over this much larger surface area. This scaffold also accommodates sensors and a transmitter that measure the loads passing through the replaced surface and notify the patient when the joint is overloaded.