More than 100 scientists from across the world gathered at NIEHS May 25 to express appreciation for Ronald Mason, Ph.D., and his tremendous impact in advancing free radical research (see sidebar).

Mason’s pioneering role in the field of free radical chemistry, biology, and medicine was celebrated during “Free Radicals: Past, Present and Future,” a symposium held in his honor at NIEHS.

NIH honored Mason with Scientist Emeritus status, under which he will continue to perform research at NIEHS. (Photo courtesy of Steve McCaw)

After more than four decades of research at the institute, Mason retired in April from his position as a lead researcher in the Immunity, Inflammation, and Disease Laboratory. His involvement in research will continue as Scientist Emeritus, a prestigious status conferred by the National Institutes of Health (NIH).

Outstanding scientist

“Ron Mason has the most original peer-reviewed publications of all principal investigators ever at NIEHS,” observed NIEHS and National Toxicology Program Director Linda Birnbaum, Ph.D.

“Ron has always been one of my role models,” said NIEHS Scientific Director Darryl Zeldin, M.D. “He is an outstanding scientist, outstanding teacher and mentor, and a solid citizen who always is willing to give back to the NIEHS community. I hope that he will continue to be involved in DIR [Division of Intramural Research] activities during his time as an emeritus investigator.”

Zeldin, left, and Birnbaum shared a laugh during one of many lighter moments of the celebration. (Photo courtesy of Steve McCaw)

Radical research

Kalyanaraman, like many of those present, blended humor and respect in his remarks. (Photo courtesy of Steve McCaw)

Mason’s career at NIEHS started in 1978 with the study of free radicals in biological systems using electron spin resonance (ESR) spectroscopy. ESR spectroscopy is a specialized technique used to detect and characterize free radicals.

“We detected and discovered new mechanisms for the generation of free radicals,” remembered Balaraman Kalyanaraman, Ph.D., who was Mason’s first postdoctoral fellow. Kalyanaraman is chair of the Biophysics Department at the Medical College of Wisconsin.

Later on, Mason introduced new strategies for detecting and characterizing free radicals in animal models of toxicity and disease. Using chemicals known as spin-traps, he detected free radicals ex vivo by ESR spectroscopy.

“The possibility of detecting free radicals generated within a living system was truly an innovation that allowed us to prove that free radicals are indeed generated in vivo,” explained Maria Kadiiska, M.D., Ph.D., staff scientist in Mason’s Free Radical Biology Group.

Kadiiska was the lead organizer of the symposium honoring Mason’s work on free radicals. (Photo courtesy of Steve McCaw)

New research technique

In 2003, Mason developed a new technique for detecting free radicals in proteins and DNA, which he named immuno-spin trapping.

“Specific and sensitive imaging of free radicals in whole animal models of diseases is now possible because of this technique created by Ron,” said Rheal Towner, Ph.D., director of the Oklahoma Medical Research Foundation’s Advanced Magnetic Resonance Center.

Excellence in mentorship

Zeldin was not the only one to recognize Mason’s excellence in mentorship. Several former postdoctoral fellows, who are now associate professors, agreed. They included Sergey Dikalov, Ph.D., from Vanderbilt University Medical College, Arno Siraki, Ph.D., from the University of Alberta, and Steven Qian, Ph.D., from North Dakota State University.

Their gratitude for Mason’s continuous support was echoed by another successful former postdoc, Marcelo Bonini, Ph.D., from the Medical College of Wisconsin. “Ron is a very generous and selfless mentor,” he said. “He is an inspiration for excellence in research and mentorship.”

The legend

“Ron is a legend,” said Birnbaum as she opened the symposium. The presentations and celebratory dinner that followed were a testament to the truth of her words. Attendees spoke of his assistance to more than 50 scientists as they established independent careers.

Mason's new status as NIH Emeritus Scientist underscores his influence and respect among colleagues and the international scientific community. Mason said he plans to continue his research at NIEHS for years to come.

(Douglas Ganini da Silva, Ph.D., is a former NIEHS research fellow and continues on as a special volunteer.)