460

there would be many more carrying out these manoeuvresnow.

Each Thursday I see about forty outpatients at two

hospitals, and about twenty-four of these get manipulativetreatment from me without general anaesthesia. Onaverage, eight of them get immediate benefit, another eightfeel better in 2 days, and in the other eight the manoeuvreshelp to maintain a " status quo ", which in a degenerativecondition is often as much as can be expected.At the Royal London Homoeopathic Hospital, we have

run a manipulative clinic once a week since 1937 (exceptfor the war years), and we are always delighted to instructgeneral practitioners interested in manipulative treatment.

London, W.C.I. W. E. TUCKER.W. E. TUCKER.

SHORTAGE OF PUBLIC CONVENIENCES

ALAN S. CLARK.

SIR,-Despite much talk of hygiene by local authorities,the number of public conveniences, especially those whichare always open, appears to be decreasing. Today Idiscovered that there are no toilet facilities whatsoever atthe very modern main Kensington Public Library, wherethere is a large reading-room. This is a sorry state ofaffairs in 1962.

London, S.W.10. ALAN S. CLARK.

SODIUM-22 METABOLISM IN IRRADIATED

PATIENTS

SiR,-The renewal of body-sodium has been studiedwith sodium 22 in patients who had had telecobalto-therapy for cancer.1 After the administration of 10-25 fjLCof 22Na the removal of radioactive sodium from the bodycan be followed by studying body radioactivity, the

specific activity of plasma-sodium, the specific activity ofurinary sodium, and urinary excretion of 22Na.The body radioactivity values plotted against time describe

an exponential curve whose emiperiod (Tl/2B) depends on theremoval of sodium, through the urine, sweat, excretions, andvomiting.The specific activity of plasma sodium plotted against time

gives an exponential curve whose emiperiod (Tl/2CB’P) is wellin accordance with Tl/2B.

In 8 pairs of cases the same average has resulted: Tl/2IXP,Tl/2B = 15 days. The emiperiod of the curve of the specificactivity of urinary sodium (Tl/2IXU) is in accordance with

Tl/2IXP. The experimental values of IX U, though, are verymuch scattered .around the interpolation line, so that smallvariations of the inclination of the curve cannot be shown.

Subtracting little by little from the injected dose, taken as100%, the proportion eliminated daily in the urine, we have anexponential curve whose emiperiod (Tl/2 U) would correspondto the emiperiod of the body-sodium if the total body-sodium,renewed by the organism, were excreted in the urine. The valuesof Tl/2 U are in the main superior to those of Tl/2 B; in 10 pairsof cases we have had an average for Tl/2U of 24 days and 13days for Tl/2B (PD<0-05).

This shows that some body-sodium is eliminated in otherways (mostly by sweating). The accompanying figure concernsa case of Hodgkin’s disease and shows the reduction of urinaryexcretion of 22Na, the reduction of exchangeable sodium from2820 mEq. per litre at first to 1910 mEq. per litre at the end.The body-radioactivity curve and the curve of specific sodium-plasma activity did not show noticeable variations.On the other hand 23Na increased in this case; in fact the

average daily excretion of sodium in the first 13 days was2-77 g. while in the last 16 days it was 3-60 g. The differencein the two averages is significant (r<0.01). These apparentlycontradictory results can be explained on the assumption thatthe body-sodium is not in the ionic state, but is linked in various1. Cignolini, P., Di Pietrantonj, F. 6th National Congress Italian Associa-

tion of Medical Radiobiology, Trieste, 1962.

ways to proteins and other substances in the plasma and the

interstitial compartment. This sodium is renewed every day byelimination in the urine, sweat, &c., and replacement with

dietary sodium. Radiation diminishes the ability to transform

dietary sodium into body sodium.The organism reacts in two ways to the diminution of

its sodium store: the kidney is stimulated to reabsorbbody-sodium, and the intake of sodium from the diet isincreased. Exogenous sodium, however, is not completelyutilised; much is excreted in the urine.Our distinction between " body-sodium" and " dietary

sodium " has a recognised precedent in iron metabolism.The iron is absorbed daily, and is promptly andcompletely utilised in hsemoglobin synthesis.

F. DI PIETRANTONJ.Ospedali Galliera,Laboratorio Isotopi,

Genoa, Italy.

A SIMPLE METHOD FOR QUICK PREPARATIONOF BUFFY COAT

PINHAS EFRATILEON ROZENSZAJN.

Kaplan Hospital,Rehovot,Israel.

SIR,-Examinations of buffy coat from peripheral bloodare routinely performed in our laboratory; we find themvery useful. The method is simple, though it demandssome technical knowledge. 1 2For the past two years we have used a simpler technique:

blood is drawn into a heparinised capillary used for micro-haematocrit (length 75 mm., diameter l’2-l mm.). After

spinning at 11,500 revolutions per minute for four minutes (weuse the International Micro-capillary Centrifuge, Model M.B.),the capillary is cut at its closed end, and at the junction betweenthe plasma and the leucocyte layers. The end of the capillarycontaining leucocytes is given a gentle tap and a small drop isdeposited on a slide. The smear is prepared in the usual wayand stained with May-Grtinwald Giemsa stain for 25% longerthan for ordinary peripheral blood-smears.

In these preparations, even in healthy subjects, we oftenfound myelocytes, few blast-cells, and nuclear fragments ofmegakaryocytes, which were not found in the ordinaryperipheral blood-smears. This method is of value in leucopenicand other pathological states, as well as in diluted bone-marrowaspirates.We believe the results compare favourably with those

obtained with the orthodox techniques of buffy coat

preparations.

1. Efrati, P., Rozenszajn, L. Blood, 1960, 16, 1012.2. Efrati, P., Rozenszajn, L., Shapira, E. ibid. 1961, 17, 497.