(Editor's note: A story on page one of yesterday's Globe quoted a former colleague of Luke Van Parijs describing his demeanor after MIT placed him on leave last year. The former colleague, who was interviewed by Marcella Bombardieri, was not speaking for attribution and should not have been quoted.)
Luk Van Parijs, the MIT professor fired this week for research fraud, may have fabricated data in two journal articles he coauthored in the late 1990s, a former colleague said, suggesting that he may have been falsifying work for as long as eight years in some of the nation's top biological laboratories.
The two papers that came to light yesterday were written while Van Parijs worked as a graduate student at Brigham and Women's Hospital, studying the immune system. The new papers -- combined with one determined to be fraudulent by the Massachusetts Institute of Technology and two others being investigated by the California Institute of Technology, where he worked from 1998 to 2000 -- expand the scope of questions that now surround Van Parijs, 35. He was dismissed Wednesday after MIT said he admitted to fabricating and falsifying data in a paper, as well as in unpublished manuscripts and grant applications.
The new revelation deepens the mystery about a rising star who was popular with students and colleagues and appeared to be a gifted biologist. In both of the new cases, it appears that Van Parijs said he had done work that he had not done, work that would have been a small part of the overall experiment.
In one case, the data in question would not have affected the conclusion, said Dr. Abul Abbas, who directed the Brigham laboratory where Van Parijs worked and was the senior author on both papers. For the second paper, the questionable data may have affected the outcome, Abbas said.
''I am just mystified," Abbas, now chairman of the pathology department at the University of California, San Francisco, said in an interview.
In both papers -- a 1998 article in Immunity, and one in 1997 in the Journal of Experimental Medicine -- graphs presenting data supposedly obtained from different mice appear to be very similar. Abbas said that he is now ''very suspicious" of the data, because it would be unlikely to have such similar results from separate animals, but that Van Parijs insisted in an e-mail earlier this month that he did not fabricate the information.
Abbas became aware of the potential problems in September when they were pointed out by a freelance journalist pursuing a story about Van Parijs. The New Scientist, a British magazine, published the journalist's article online yesterday, describing the apparent problems with the papers.
In the two papers, Van Parijs was investigating the function of T cells, which are part of the immune system. Van Parijs ran samples of the cells through a device known as a flow cytometer, which sorts the cells by the characteristics in which the scientists are interested. This produces plots, essentially diagrams with large numbers of dots, with each dot representing a cell.
In both papers, there are plots that appear to be almost identical, even though the paper says they are sets of cells from different mice. Using only one mouse would have saved time. The plots are not exact copies, though, which Abbas told the Globe has made him more concerned, because if the data are fraudulent, it implies they were done intentionally. Changing data or inventing it is considered a very serious offense, regardless of the effect the act has on the conclusions made in a research paper, scientists said.
Abbas said there would be some investigation into the work Van Parijs did at Brigham and Women's, but he was not sure how that inquiry would proceed. He said he would like to see that all of Van Parijs's work from that period is examined. But he said the decision is up to the hospital, because it would a very time-consuming and complicated undertaking. ''From my perspective, I would like to reassure myself about all of them," he said.
Brigham and Women's issued a statement saying it was aware that questions had been raised about research done while Van Parijs was there, but officials have not said whether they will investigate.
Abbas said he considered Van Parijs an extremely prolific scientist, but said he never had a reason to suspect that Van Parijs might be cutting corners. ''I always thought he was extremely industrious, and he put in long hours in the lab," said Abbas. ''I used to see a lot of primary data when he was in the lab, and it looked fine. There was really no reason to doubt what he was doing."
After Van Parijs earned his doctorate, he joined the lab of Nobel laureate David Baltimore, first at MIT and then at the California Institute of Technology, where Baltimore is now president. Even though Caltech is scrutinizing two of the papers Van Parijs published while there, both in the journal Immunity in 1999, Baltimore said he knows from work that his lab has done following up on Van Parijs's research that a lot of what he did is, in fact, verifiable.
''So I don't know where he cut corners and where he didn't," Baltimore said Thursday. Baltimore declined to describe his concerns with the two Immunity papers.
It is not unusual to see cases of fraud involving data that are tangential to the main point of a research paper, as is alleged in some of Van Parijs's work, according to C.K. Gunsalus, a special counsel at the University of Illinois at Urbana-Champaign, and specialist on research integrity.
''It is very common, and there is also a common defense, which is 'I have a PhD and I wouldn't have done something so stupid,' " said Gunsalus. Often, she said, this defense is successful. She also said that it was common to see a pattern of escalation, with small infractions building over time to larger ones.
Van Parijs did not return an e-mail and a phone call yesterday requesting an interview.