Seminal research

David Appleton
 

Ladies and Gentlemen:

  Were I to learn that Sir Nick had postponed his retirement for such a long time just to reduce the proportion of his career that he spent working with me, I would be rather distressed. After all, I retired 21 years ago so that the proportion of my career that I spent working with him would decrease no further. But, be that his motivation or not, he has only brought the proportion down to about a quarter, because between 1972 and 1983 we co-authored at least one paper every year, publishing thirty-eight in all. Even now, when his CV lists over 400 substantive publications, I believe I rank fourth in co-authorship frequency behind  Richard Poulsom, Robert Goodlad and Malcolm Alison, who were stuck with him for many years. I’m sorry, I’ll read that again: who stuck with him for many years. Stuart McDonald and Trevor Graham may yet also overtake me, because I am not sure that retirement necessarily means an end to Sir Nick’s distinguished and wide-ranging publishing career, though it is not as wide-ranging as Wikipedia till quite recently would have had us believe. Sadly it no longer credits him with a book called Knights and Peasants.1

  I first came across Nick (peasant as he then was) in 1971 when I was a young mathematician-turned-computer-scientist who was more than a little surprised to find himself a lecturer in medical statistics. We were introduced by a more senior colleague of his, Adrian Morley, who was to become an internationally renowned renal pathologist, a model engineer, a pianist and a painter, while carrying out groundbreaking work on a series of allotments. Happily Adrian is here today and he has supplied me with a photograph of the young Nick we knew. The following year the three of us published our first article together2: Variation in the duration of mitosis in the crypts of Lieberkühn of the rat; a cytokinetic study using vincristine. That paper foreshadowed Nick’s commitment throughout his career to studying the gut, especially its stem cells, and to supporting, and in due course editing, the journal then called Cell and Tissue Kinetics and now entitled Cell Proliferation.

  However, seven of the papers which followed3-9 were not gut-related but were concerned with the response of the prostate of the castrate mouse to the administration of testosterone, and the method of analysis just happened to suit my computing expertise perfectly. It also neatly completed the spectrum of uses of computer simulation in university teaching, administration and research, which I was putting together for my PhD thesis10. The early seventies were an exciting time for finding out what problems could be solved using the increasingly powerful computers which were becoming available. I couldn’t have been luckier in the problem my new colleagues brought to me, nor indeed in them as colleagues.

  The emerging statistician in me must have questioned whether the sample size for the intended experiment was large enough, because Nick invited me to the animal house where Adrian and he were about to respectively anaesthetise and castrate some mice. “This is what it means when you say n must be greater,” he said, wielding his scalpel. Managing to avoid his blade, I nevertheless took his point. (Nick tried to disconcert me on another occasion when I asked if I could make a phone call. “There’s an extension in here,” he said, opening the door to the mortuary.) But on sample sizes we were basically of one mind. When Nick performed an experiment, no-one ever needed to replicate it. And, unsurprisingly, that remained true when the experimenter was one of his PhD students or post-docs. The computer was fed tray upon tray of punched cards recording the positions of labelled and mitotic cells in the intestinal crypts of mice and rats subjected to various regimes. I am relieved to note that in the human intestine we counted only mitoses.

  Our prostate collaboration went well. With the aid of a diagram Nick and Adrian introduced me to the G1, S, G2 and M phases of the cell cycle, and, once I took on board that for every cell which entered the M phase two emerged, it proved possible to produce a satisfactory model of what was taking place, fitting the data recording how the labelling and mitotic indexes changed over time after testosterone injection, even showing that the probability of cells leaving the cell cycle to differentiate couldn’t be constant but must depend on feedback from the already differentiated cells. The model also predicted how the amount of DNA would change over time and happily that was confirmed experimentally by Malcolm Alison. It was important that each mouse contributed to two parallel experiments, for if only the cells in the seminal vesicle had been counted we might not have interpreted the data so successfully; it was the results from the coagulating gland which put us on the right track. 

  Other simulations involved the use of the CELLSIM program produced and developed by CE Donaghey at Houston11. Even after I retired it helped me to understand the data from an experiment I had not helped design and which I had hitherto not fully understood because the times between samples were too long12. I believe that we were better able to design and analyse experiments, particularly those using the fraction labelled of mitoses method to estimate cell cycle time, because before we carried them out we could simulate different versions of what we thought the cells might be doing, generate data from these simulations, analyse them as if they were experimental data, and see if we came to the right conclusions. And we could concentrate our observations at times when we expected rapid change.

  Naturally we presented our results at conferences. I still have fond, alcohol-enhanced memories of them: Cardiff (just beer), Manchester (quite a lot of beer, did Nick really mean that dart to hit me?), Oxford (competitive Guinness drinking with Professor Len Lamerton, who gave us so much encouragement), Paris (vin rouge, très ordinaire), Aviemore (Drambuie, compliments of the organisers), St Andrews (dry sherry, wine and Islay malts), Copenhagen (Martinis, in Tom Lehrer’s words ‘six parts gin to one part vermouth’). Montreux was the exception: having dined the first evening with Niels and Birta Hartmann (our hosts in Copenhagen) we could just about afford a cheese fondue and a little chocolate for the rest of the week, certainly no other stimulants. This exposure to increasingly alcoholic drinks was probably part of Nick’s attempt to cure me of what he saw as a problem. “You Scottish mathematicians are always two pints below par at the start of an evening,” he told my PhD student, Derek Hull, and me. Well, I admit we lacked his ebullience, but we had that in common with much of the rest of the world. 

  At one conference a professor of pathology enquired who I was and on being told that I was the medical statistician on the team, he exclaimed “Good god, I know people who have used them, but I’ve never known anyone take one to a conference.” One of Nick’s great strengths was to embrace collaboration. Compared to working with (or should that be for?) many clinicians, working with Nick and his fellow laboratory based pathologists was a pleasure; we shared our expertise and we enjoyed learning from each other. It was no different when we were writing papers: I would draft the Results section, then Nick, with his knowledge not just of the latest experiments we were reporting, but also of all the relevant literature, would rapidly pour thousands of words onto paper and let Alex Watson and me, pedants both and growing used to his handwriting, turn them into something rather more concise, that editors, even the editors of Virchow’s Archiv, were more likely to accept. He called us ‘the Scottish grammarians’. Alex had been Nick’s mentor in the art of reporting biopsies and he was even more demanding of accuracy in that context than he was of correct syntax. Nick never forgot that rigorous grounding. Some of you may have been subjected to his version of it.

  Talking of the speed at which Nick tended to do everything reminds me of one particular occasion. I had just given a talk in Würzburg, scheduled very understandingly during their Bach Festival by the delightful Brigitte Maurer-Schultze, who said to me “You are very didaktisch; you speak quite slowly, and you say everything twice. Nick was here last month; he said everything once, very fast.” 

  I would like to move from Nick’s speed to his subtlety: an under-appreciated aspect of his personality. If you have ever thought his approach to problems excessively taurine I urge you to reconsider. This is neither the time nor the place to go into the means by which he scuppered the chances of a rival but less wily suitor for the affections of Vera, his wife-to-be, but hearing how he achieved that led me quite early to the conclusion that Nick has in fact an extremely vulpine nature and his apparent lack of cunning is merely part of the persona it has pleased him to cultivate. Long before he became a knight Nick could move one square forward and two to the side.

  I will not, however, pretend to call him subtle as a sportsman. Let me quote from the citation delivered when Nick was awarded an honorary DSc by the University of Bristol: “He is remembered by a contemporary medical graduate of the University of Newcastle, our Vice-Chancellor, as a particularly violent rugby player.” As a cricketer he bowled fast, right arm round the wicket, using a roundarm action, film of which Lasith Malinga may have seen as a boy: never mind the stumps, hit him where it hurts. I once played football with Nick, twice was not an appealing prospect; he had taken off his specs and as a result his teammates were in as much fear of his tackles as the opposition. After Nick left Newcastle I discovered croquet; I’m glad he never did, for by now it would be a contact sport. As, of course, was conversation to Nick; I often thought of wearing shoulder pads. 

  It was a blow of a different kind when Oxford offered Nick a readership, but given the combined weight of his MD and PhD theses13,14, it was almost inevitable that somewhere would. Fortunately for me he had already selected and trained as his successor the very knowledgable and experimentally adept Jim Sunter, and as a result Jim, Alex and I co-edited a book Cell Proliferation in the Gastrointestinal Tract15 and co-authored more than thirty publications until Jim’s increasing interest in forensic pathology and the departure of other colleagues gradually brought to an end the study of cell proliferation in Newcastle.

  One planning meeting at Nick’s house sticks in my mind. Jim had a liking for cigars. When he lit one Nick said, “You can smoke that on the front step,” and banished Jim to the garden. Vera discovered what was happening and made Nick let Jim back in. Their pyjama’d something-like-seven-year-old daughter then appeared crying, “Daddy, daddy, I think the house is on fire.”

  By the time Nick left Newcastle I was pretty sure what the future held for him; it is after all the business of a statistician to make predictions. There is a song well known on Tyneside called Keep your feet still, Geordie, hinny and I wrote a loose parody Keep your feet still, Nicholas, hinny for his leaving do. The chorus after most of the verses looked back to the prostate experiments:

Oh, testosterone will stimulate the cells out of G0,
Sending 95% into G1,
Then they pass into the S-phase, through G2 and into M;
Some decycle but the others carry on.

  Like the last verse, which included the words ‘chair’ and ‘knighthood’, the final chorus looked to the future; this time I will spare you my singing:

Nick will stimulate the workers, Nick will make the grants flow in,
Just like autumn leaves, the papers they will fall.
Nick will climb the academic ladder till he’s at the top,
Nick will drive his hapless colleagues up the wall.

  I invite those of you who have known Nick during the latter three-quarters of his career to judge whether I was correct in my interpretation of the data he presented me with in the first quarter.

  Ladies and gentlemen, I thank you for your attention and responsiveness to my rambling reminiscences. Nick, I thank you for letting me join you in some fascinating, sometimes exhausting, but always enjoyable research. I wish you a long and very happy ‘retirement’.

References

1. Wright, Nicholas. Knights and Peasants: The Hundred Years War in the French Countryside, Boydell & Brewer, Rochester, NY (1998), ISBN 9780851158068

2. Wright NA, Morley AR, Appleton DR & Watson AJ. Variation in the duration of mitosis in the crypts of Lieberkühn of the rat; a cytokinetic study using vincristine. Cell & Tissue Kinetics 5 (1972) 351-364

3. Morley AR, Wright NA & Appleton DR. Cell proliferation in the castrate mouse seminal vesicle in response to testosterone propionate. I. Experimental observations. Cell & Tissue Kinetics 6 (1973) 239-246

4. Appleton DR, Morley AR & Wright NA. Cell proliferation in the castrate mouse seminal vesicle in response to testosterone propionate. II. Theoretical considerations. Cell & Tissue Kinetics 6 (1973) 247-258

5. Morley AR, Wright NA & Appleton DR. Testosterone-induced cell proliferation and differentiation in the mouse seminal vesicle. An experimental and computer simulation study. In The Cell Cycle in Development and Differentiation, ed. Balls M & Billet FS, CUP (1973) 337-340

6. Morley AR, Wright NA, Appleton DR & Alison MR. A cytokinetic analysis of the proliferative response to androgen in the prostatic complex of the castrated mouse. Biochemical Society Transactions 1 (1973) 1081-1084

7. Alison MR, Appleton DR, Morley AR & Wright NA. Cell population growth in the castrate mouse prostate complex: experimental verification of computer simulation. Cell & Tissue Kinetics 7 (1974) 425-431

8. Morley AR, Appleton DR, Wright NA & Alison MR. The proliferative response of the coagulating gland of the castrated mouse under continuous androgen stimulation: an experimental and computer simulation model. Journal of Endocrinology 65 (1975) 353-361

9. Alison MR, Wright NA, Morley AR & Appleton DR. Cell proliferation in the prostate complex of the castrate mouse. Journal of Microscopy 106 (1976) 221-237. 

10. Appleton DR. Simulation in an interactive computer environment. PhD thesis, University of Newcastle upon Tyne (1972)

11. Donaghey CE. CELLSIM II Users Manual. University of Houston (1975)

12. Appleton DR, Thomson PJ, Donaghey CE, Potten CS & McGurk M Simulation of cell proliferation in mouse oral epithelium, and the action of epidermal growth factor: evidence for a high degree of synchronization of the stem cells. Cell Proliferation 35 Suppl  (2002), 68-77.

13. Wright NA. Studies in cell proliferation in the small intestinal mucosa: an experimental and clinical study. MD thesis, University of Newcastle upon Tyne (1973)

14. Wright NA. Studies in the control of cell proliferation in mammalian tissues. PhD thesis, University of Newcastle upon Tyne (1975)

15. Appleton DR, Sunter JP & Watson AJ (eds). Cell Proliferation in the Gastrointestinal Tract. Pitman Medical, Tunbridge Wells (1980), ISBN 0 272 79597 6