"Sloppy work" and not fraud led to graphs that made it appear that the results of one set of experiments were used to illustrate articles about a different set of experiments, Dr. Gerald M. Rosen told a Baltimore County Circuit Court jury yesterday.
"All the experiments were done, to the best of our ability," the University of Maryland researcher said.
A six-woman jury under Judge Joseph F. Murphy Jr. is hearing Dr. Rosen's $105,000 defamation of character suit against Dr. Carmen M. Arroyo, his former research associate, and her husband, Dr. Alasdair Carmichael, who is also a research scientist.
Dr. Arroyo has accused Dr. Rosen, chairman of the Department of Toxicology and Chemistry at the university's pharmacy school, of a pattern of professional misconduct that included falsifying experimental data in scientific articles used in applying for grants and using her work without giving her credit.
At issue yesterday were graphs representing the action of free radicals, submicroscopic particles that are believed to be important in the understanding of disease. The particles can be measured only by a sophisticated machine, which also picks up background noise from the room that serves as a unique "signature" for each experiment.
Because the background noise signatures on graphs showing the results of experiments allegedly carried out at different times were the same, Dr. Arroyo said, Dr. Rosen was using old data to report the results of new experiments funded by the federal government.
Dr. Rosen testified that the graphs, also known as scans, that accompanied his articles were merely representations of the results and are not the critical data in the experiments.
The text of the articles, he said, contained the real data, the numbers scientists would need to understand and reproduce the work.
He said a researcher in his laboratory who prepared the article in question while Dr. Rosen was at Duke University 10 years ago mistakenly used old graphs to illustrate the new data, although Dr. Rosen reviewed it before submission.
"I did not know the scans had been used before. It was sloppy. I just missed it," he said.
Dr. Elmer J. Rackman, a former research associate of Dr. Rosen, supported his former colleague and testified that the numbers were the critical data. Under cross-examination, he said that though it is best to present the original scan in a publication, representative scans may be used.
"All the experiments in the papers were done, absolutely. I was there," Dr. Rackman said. "I do not believe Dr. Rosen is a fraud. I was with him. I did a lot of the studies, and I saw him doing the work. It would be difficult for me to believe that anything was fabricated."