909

chance phenomenon due to the great variability of theHL-A system.

Universitäts-Kinderklinik,Institut fur Immunologie,Institut fur allgemeine undexperimentelle Pathologie,A-1090 Vienna, Austria.

G. GRANDITSCHH. LUDWIGZ. POLYMENIDISG. WICK.

USE OF CHLORAMPHENICOL

SIR,-The point about the worldwide variation in theuse of chloramphenicol is well made. A few years ago Ifound that chloramphenicol was being issued as a prophy-lactic in a cholera quarantine camp in eastern Iran. Itwas readily changed to tetracycline after protest and itseemed that these two drugs were regarded as inter-

changeable.Leicester Royal Infirmary,

Leicester LE1 5WW. GEOFFREY H. ROBB.

DIALYSIS AND LEAD ABSORPTION

SIR,-I read with much interest the letter by MissJeanette Blomfield (Sept. 22, p. 666). My own view is thatwhen a patient is dialysed against fluid prepared fromuntreated tap-water, he is subjected to two unnecessaryuncertainties. Firstly, because the composition of tap-water is subject to seasonal, daily, even hourly changes, itcan be difficult to maintain the electrolyte balance. Secondly,because the patient is exposed, under conditions favourableto exchange, to something like 300 times the normal waterconsumption, toxic ions well below the permissible thres-hold for drinking can become important.As Prof. D. N. S. Kerr, of Newcastle upon Tyne,

pointed out at a recent symposium on renal dialysis,removal of most of the solutes from tap-water is normal forintravenous infusion, peritoneal dialysis, or even to washout the bladder; so why not for renal dialysis ?Mixed-bed ion exchange provides a simple and con-

venient means of removing more than 99-9% of the totalsolutes from water. Suitable equipment is readily availableto equip both renal wards and home-dialysis patients withsystems which are self-contained and easy to use, sinceregeneration of the resins is either carried out centrally ordisposable cartridges are used. If the problem can bediminished so simply, is it justifiable not to do so ? ?

Elga Products Limited,Lane End,

Buckinghamshire HP14 3JH.D. M. C. THOMAS,Technical Director.

GAMES AUTHORS PLAY

SIR,-Dr Siegel (Sept. 29, p. 773) has performed aservice in drawing attention to some of the undesirablemethods used to multiply publication credits. Anotherfrequent ploy is the securing of senior author status byall the participants in an investigation. Thus Jones, Smith,and Brown amass enough results to provide one reasonablysubstantial paper. They then publish it in three parts,permuting the authorship to Jones, Smith, and Brown;Smith, Brown, and Jones; and Brown, Jones, and Smith.Yet another " game

" is multiple publication of the samepaper, sometimes in different languages. This may bejustified in the case of, say, a Japanese worker who wishesto make his findings known both to his compatriots and toa wider non-Japanese-speaking readership; but I havetncountered multiple publication in English alone, or in,for example, English, Dutch, and German.Unfortunately, these games are not amusing. As well as

mmping the s ientifi ommuni ations t with un

wanted background " noise " they result in an appallingwaste of time, energy, and material resources; but they willpersist as long as the weight of reprints produced influencesthe award of jobs or grants. Vigilance by editorial staffs andparticularly by referees may help to mitigate these abuses,but here we enter a vicious circle in which the ability ofreferees to keep up with the literature is considerablyimpaired by the steady increase in its volume.

Department of Virology,Lister Institute of Preventive

Medicine,Chelsea Bridge Road,London SW1W 8RH. LESLIE COLLIER.

T-CELLS IN CHRONIC LYMPHATIC

LEUKEMIA

SIR,-We reported (June 30, p. 1508) that a smallfraction of chronic-lymphocytic-leukmia (C.L.L.) lympho-cytes responsive to phytohaemagglutinin (P.H.A.) could beseparated from the unresponsive population by albumindensity-gradient centrifugation. Since the response of theformer fraction to the mitogen was still delayed comparedwith that of normal lymphocytes, it was concluded that theP.H.A.-responsive c.L.L. lymphocytes were, in some aspects,abnormal. Dr Wybran and Dr Fudenberg (Aug. 4, p. 265)did not accept this conclusion. We have presented addi-tional data 1 on the P.H.A. stimulation of C.L.L. lymphocytes,concerning their cell cycles. The length of the cell cycleand the S period of normal and C.L.L. lymphocytes stimu-lated by P.H.A. were determined by the method of Sasakiand Norman. The length of the S period was also estimatedby double-labelling. The observed values for the meanlength of the cell cycle were 20 hours in normal lympho-cytes and 28 hours in C.L.L. lymphocytes. The length ofS was 12 and 16 hours respectively, estimated both by thelabelled-mitoses technique and the double-labelling method.Thus the delayed peak of D.N.A. synthesis of C.L.L. cells

may be partly due to their longer cell cycle. These data

support our previous conclusion that the bulk of the P.H.A.-responsive C.L.L. lymphocytes may be leukaemic.

Division of Haematology,Medical Clinic,

University of Turin,Corso Polonia 14, Turin 10126,

Italy.

L. PEGORAROB. JAKŚIĆF. GAVOSTO.

T-CELL PROPERTIES OF LEUKÆMIC

PLASMA CELLS

SIR,-The observation of T-cell properties in leuksemicplasma cells (L.P.C.) seems to be relevant to the discussionabout the nature and the origin of proliferating cells inlymphoproliferative diseases. T-cell markers have beenfound to be predominant in the proliferating or accumu-lating cells in some instames.3-s

In our case the presence of T-cell properties on cells ofsuspected B-cell origin may be an indication of the existenceof subpopulations of human lymphocytes previously undis-covered because of their low number. Alternatively, somekind of modulation of cell-surface properties by the

oncogenic transformation has to be taken into consideration.

1. Jakśić, B., Matera, L., Pegoraro, L. 2nd Meeting of European andAfrican Division of International Society of Hæmatology, Prague,Aug. 27-29, 1973; p. 383.

2. Sasaki, M. S., Norman, A. Nature, 1966, 210, 913.3. Smith, J. L., Barker, C. R., Clein, G. P., Collins, R. D. Lancet,

1973, i, 74.4. Catovsky, D., Galetto, J., Okos, A., Galton, D. A. G., Wiltshaw, E.,

Stathopoulos, G. ibid. Aug. 4, 1973, p. 232.5. Lille, I., Desplaces, A., Meeus, L., Saracino, R. T., Brouet, J. C.

ibid. p. 264.6. Brouet, J. C., Flandrin, G., Seligmann, M. New Engl. J. Med. 1973,

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