Lives of the fellows

John Chaplin Sloper

b.2 March 1922 d.14 June 2000
MB BChir Cantab(1945) MRCP(1946) MD(1951) FRCPath(1966) FRCP(1968)

John Sloper was professor of histopathology at the University of London. His father, a retired RAMC colonel who had settled in the early 1920s in Singapore as a general practitioner, had many forebears practising medicine in the Bristol and South Wales area. John's maternal grandfather, William Pruen, had been a medical missionary in China. Educated at Sherbome School and Corpus Christi College, Cambridge, John took to investigatory medicine and pathology at the London Hospital with untiring enthusiasm.

After qualification, during his three years in the army, he was posted to Singapore as a member of the RAMC dermatological research team studying fungal skin infections. From these studies came his MD thesis for which he was awarded the Copeman medal.

On his return to the London Hospital, John worked in the Bernhard Baron Institute of Pathology on the pathology of endocrine disorders. He was encouraged by Dorothy Russell [Munk's Roll, Vol.VII, p.510] and Carl Crooke [Munk's Roll, Vol.IX, p.106], both of whom had recently contributed to the pathology of Cushing's disease. Beginning with Addison's disease, John later turned to diabetes insipidus which was then little understood. With C W M Adams [Munk's Roll, Vol.IX, p.2] he devised a new and effective stain for human neurosecretary material that enabled him to show the material in the posterior pituitary originated in hypothalamic neurons and passed along axons to the posterior pituitary by axoplasmic transport mechanisms. This early demonstration of axoplasmic transport led him to publish a number of papers as well as an authoritative review on the role of the hypothalamic-posterior pituitary system in diabetes insipidus.

After these studies, carried out when a lecturer and senior lecturer at the London Hospital Medical College, he became reader in Histopathology at the Charing Cross Hospital Medical School in 1956. He was awarded a personal chair in experimental pathology in 1966.

He set up a research department at the West London Hospital which included an electron microscope, the first in a pathology department in London. It was here that he not only continued to make further advances on the pathology of diabetes insipidus, but he also came to provide a diagnostic service for muscle disease. Not one to be content with providing a routine service, this inevitably led to the development of a long sustained research project into the basic question as to whether muscle function in dystrophic muscle could be restored by transplantation of muscle cell precursors from other sources. The question of muscle regeneration from precursor cells (myoblasts) and whether donor and host cells would fuse on grafting were among the outstanding problems of muscle disease of the time.

Using a dystrophic mouse model he and his colleagues, several of whom later became internationally recognised scientists in their own right with their own departments, published a series of valuable papers on this subject that went rather further than others had done in that he put forward the then quite heretical idea that stem cells from the circulation might play a role in restoring function to damaged muscle. This suggestion inevitably led to some controversy at meetings, but in the last few years his view has been vindicated by the demonstration that uncommitted stem cells from other sources might in fact transform to muscle cells as he predicted.

John was very much in the mold of the doctor-scientist dedicated towards the investigation of clinical disease by scientific methods as had been conducted over the previous century by so many physicians, and for which there was a particular tradition at the London Hospital. He always encouraged co-operation wherever possible with clinical colleagues, an example being the comprehensive biopsy service he developed for Hugh de Wardener's renal unit at the Charing Cross Hospital.

Life was never dull when John was around and everyone became aware of his presence from his critical and incisive comments and his sharp questions that were always directed towards uncovering the truth about the matter under debate. He would particularly make his views known in committees if he felt that academic standards were being in any way compromised. In 1982 he was appointed professor of histopathology at Charing Cross and when the Westminster and Charing Cross Medical Schools were joined he had the responsibility of being head of the combined department. He had always retained an interest in his classical education and spent a happy retirement studying archaeology and travelling.

He married his wife Susan in 1946 and they had three daughters, all of whom are doctors.

David Woodrow
John Cavanagh

[Brit.med.J., 321,2000,965]

(Volume XI, page 526)

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