PROFESSOR Jean Bernard was the leader of a revolution that transformed medicine in the 20th century. He helped to place haematology in the vanguard of medical science from the l950s onwards. He gained a world reputation with an effective treatment of leukaemia in children.

He observed that the repeated application of tar to the human skin frequently results in skin cancer. To find out the effect that tar would have on blood, he injected it into rats through the bone marrow, where blood is formed. It invariably provoked leukaemia in the animals. From that moment, Bernard began to treat leukaemia as a cancer of the tissues, particularly of those tissues that produce blood.

In l950 he described the first chemically induced leukaemia in human beings. And he widened that research by studying people in the oil industry who were regularly exposed to crude oil. The ultimate breakthrough came in l962 when he isolated rubidomycene for use as medication. By treating leukaemia patients, particularly young ones, with rubidomycene he obtained remissions that proved ever more stable to the point, ultimately, of permanence.

Jean Bernard was born in Paris in 1907 and graduated in medicine there in 1926. He came into haematology by chance. At the end of the first stage of his medical studies, he took the exam for fast-track interns in the teaching hospitals. He failed. So he went to look for a job as a provisional intern in a hospital near his home. He found himself working for Paul Chevallier, one of the leading haematologists of the interwar years. Immediately he was hooked on the subject. Within a couple of years, at the age of 24, he had with Chevallier founded the first Scientific Society of Haematology.

During the war he joined the French Resistance within weeks of the occupation of France by German forces in the summer of l940. So he became one of only 500 who held the Resistance Card of l940. His underground duties were to parachute arms to resistance groups in southeast France. Bernard was eventually caught and imprisoned in the Fresnes prison in Paris in l943. He was freed shortly before the liberating British, American and Free French forces arrived in the summer of l944, and went back on active service until the guns fell silent in May l945. He was decorated with the Croix de Guerre and the Médaille de la Resistance.

In his early thirties Bernard spent some years pursuing in-depth studies in bacteriology and immunology at the Pasteur Institute in Paris under world-class specialists such as Gaston Ramon and Robert Debré. When he returned to haematology and his focus on cancers of the blood, he recognised that Louis Pasteur’s principle of looking for one germ as the cause of one particular infection, could not be applied to cancer work.

Cancers, he established, were the result of the interaction of more than one factor in the human physiology. With that he helped to revolutionise haematology and also the pathology of cancers, first as an associate professor of medicine at the University of Paris from l949, as Professor of Cancerology from l956, and concurrently as chief medical officer at the Hôpital St Louis from l957, and as Clinical Professor of Blood Diseases from l961.

Bernard also played a key role in the preparatory work that led to the success of organ transplants. One of the research teams under his direction was led by Jean Dausset and focused on immunology and ultimately on histocompatibility. That led to the effective treatment for “rejection” of transplanted organs.

Bernard impressed his peers with the scalpel-sharp lucidity of his intellect, as well as his moral strength and courage.

In his retirement years and into his nineties, he wrote many books on the philosophy of medicine and medical ethics. Grandeurs et tentations de la médecine (The Grandeur and Temptation of Medicine), published in l973, and L’Homme changé par l’homme (Man Changed by Man), published in l976, became standard works. His last work, Si Hippocrate voyait ça (If Hippocrates Saw This), published five years ago powerfully explored the conflict between the technically possible in medicine and the morally acceptable.

He gave warning that human dignity and human individuality were being lost in allowing medicine to pursue what is possible and ignore what is desirable.

Bernard was at various times president of the International Society of Haematology, of the French Academy of Science, of the French National Academy of Medicine, and of France’s National Committee of Medical and Life Science Ethics. He was also elected to the Académie Française, the highest accolade France bestows on its intellectual giants.

Professor Jean Bernard, haematologist, was born on May 26, 1907. He died on April 17, 2006, aged 98.