274

cent. of its total receipts from services rendered.Its deficit for the year is -&bgr;614, or 7-3 per cent. of itstotal general expenditure. Only 26-7 of its beds arevacant and the statistical cost per occupied bed iseven lower-i.e., Bill-2. It is not easy to interpretthese contrasts in general terms or to draw con-

clusions from the analysis here provided.Emphasis is again laid by the Fund on the fact

that high cost does not necessarily mean excessiveor extravagant expenditure, though figures abovethe average for the particular group of hospitalsneed scrutiny. Hospital managers are urged to

attempt to detect the source of any excess expenditureand " to reduce it wherever it cannot be justified orto justify it wherever it cannot be reduced."

"IT CAN DO NO HARM"

THIS facile phrase, quoted by Dr. Colebrook in hisletter on p. 286 condemning the indiscriminate use ofsulphanilamide or related drugs, has been responsiblefor much confusion in therapeutics. Moreover-andthis is more serious-it has often had to be withdrawnwhen applied prematurely to potent new remedieswhose dangers are not at first apparent. Dr. Cole-brook is asking for greater caution in the use of

sulphanilamide for prophylactic purposes and he

speaks with authority when he says that there is. no experimental justification at present for givingthis drug to pregnant women before labour has actuallystarted. The object of giving it as a prophylactic,either in labour or in other conditions, is almost

always to prevent harm from haemolytic streptococci,and where the risk of sepsis is small it has to bebalanced against the risk of harm being caused by thedrug itself-a risk that is at least appreciable andmay yet prove to be graver than is now believed.There is no need, however, to recapitulate Dr.Colebrook’s argument. Its wisdom is made all themore evident by the footnote he has added to hisletter.

IS PITUITRIN A HORMONE?

THE path of the endocrinologist is beset withsnares, and one of the most awkward is the uncer-

tainty whether a particular extract of a gland is atrue hormone or merely a chemical artefact. Wherethe hormone in question is of uncertain compositionand not demonstrable in the blood or urine the uncer-

tainty can only be resolved by appeal to circumstantialevidence. Parathormone, for instance, has so fardefied analysis and cannot be detected in blood. Yetthere is hardly room for doubt that it is concernedin normal calcium metabolism. The presumed hor-mones of the posterior lobe of the pituitary, in con-trast, are less securely enthroned. Vasopressin is

certainly capable of constricting vessels and raisingthe blood pressure, but it would need a great deal ofassurance to assert that this substance is concernedin the normal regulation of blood pressure. Theantidiuretic hormone, which may or may not be thesame as vasopressin, acquires some degree of veri-similitude from the facts that diabetes insipidus iscommonly associated with destructive lesions in thepituitary-hypothalamic region and that it respondsto treatment with vasopressin. More direct evidenceof natural secretion of the hormone has been soughtfor many years but, although it has been stated fromtime to time that pituitrin is demonstrable in suchfluids as blood and cerebro-spinal fluid, none of thesestatements has stood the test of time, and it isevidently beyond the scope of available methods todetect directly such minute concentrations of hormone

as may be present. Concentrating the suspect fluidis at first sight an easy way out of the difficulty, butthe parallel increase in salt concentration makes theconcentrate unsuitable for antidiuretic assay. Gilmanand Goodman,1 however, working with rats’ urine,have surmounted this obstacle by dialysing the urineagainst tap-water across a Cellophane membranepermeable to electrolytes but not to antidiuretichormone. Having thus removed the salt, it was a

simple matter to concentrate the remaining solutionof hormone. Gilman and Goodman began their workon the assumption that if the antidiuretic hormoneserves any useful purpose it is presumably that ofconserving body fluid in the face of threatened- dehy-dration. They found that urine from normal ratscontained no demonstrable antidiuretic hormone,but if the rats were dehydrated, either by fluid restric-tion or administration of hypertonic saline, con-

siderable quantities of hormone could be recoveredfrom the concentrated urine. A dehydrated rat mayexcrete as much as 0.25 unit of antidiuretic hormonein 72 hours-i.e., about 250 times the minimal dosethat will inhibit diuresis. The greatest rate of excre-tion is reached within 48 hours, and further dehydra-tion does not increase the rate. That the excretedhormone is derived from the pituitary is shown bythe fact that hypophysectomised rats excrete nonein response to dehydration. It seems clear, therefore,that in the rat, at least, the antidiuretic hormone isa true hormone concerned in normal water meta--bolism. If it can be shown that the same is true ofthe human subject, it should become possible to

investigate the role of this hormone in disease.

VITAMIN F AND THE COMMON COLD

FROM an experiment on rather a small scaleOncken 2 concluded that consumption of oils contain-ing unsaturated fatty acids might prevent colds.This possibility has now been further explored byEldon Boyd and Ford Connell,3 of Queen’s University,Kingston, Ontario. A total of 106 young men,

mostly medical students, cooperated in their investiga-tion. They were divided into two groups, 41 whosaid they were susceptible to colds and 65 who saidthey were not. Both groups were observed over a

preliminary period of seven weeks beginning on

Jan. lst of this year, during which the " susceptibles "had 63 colds, or 1.54 per person, and the "non-susceptibles" " had 53, or 0.82 per person. The

average duration of each cold was 7-2 days in thefirst group and 4-7 days in the second. During asecond period of seven weeks each of the susceptibleswas given 15 minims daily of vitamin F (a purifiedconcentrated mixture of linoleic and linolenic acidsprepared from refined linseed oil) ; the non-

susceptibles served as controls. During this time the41 susceptibles had 23 colds (compared with theirprevious 63) or 0-56 per person, with an averageduration of 4-5 days. The 65 non-susceptibles had41 colds (compared with their previous 53) or 0.63 perperson with an average duration of 6.1 days. Inother words the incidence fell nearly twice as heavilyon the susceptibles during the first period, and theaverage duration of their colds was longer, whereasin the period during which they were specially treatedthey were slightly better off than the non-susceptibles.It is necessary, however, to look carefully at thisresult. The original division of the two groups is

1 Gilman, A., and Goodman, J., J. Physiol. 1937, 90, 113.2 Oncken, M., Illinois med. J., 1935, 67, 236.

3 Boyd, E. M., and Connell, W. F., Canadian med. Ass. J.July, 1937, p. 38.